mariadb/mysql-test/main/lock_sync.test

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Fix for bug #45143 "All connections hang on concurrent ALTER TABLE". Concurrent execution of statements which require non-table-level write locks on several instances of the same table (such as SELECT ... FOR UPDATE which uses same InnoDB table twice or a DML statement which invokes trigger which tries to update same InnoDB table directly and through stored function) and statements which required table-level locks on this table (e.g. LOCK TABLE ... WRITE, ALTER TABLE, ...) might have resulted in a deadlock. The problem occured when a thread tried to acquire write lock (TL_WRITE_ALLOW_WRITE) on the table but had to wait since there was a pending write lock (TL_WRITE, TL_WRITE_ALLOW_READ) on this table and we failed to detect that this thread already had another instance of write lock on it (so in fact we were trying to acquire recursive lock) because there was also another thread holding write lock on the table (also TL_WRITE_ALLOW_WRITE). When the latter thread released its lock neither the first thread nor the thread trying to acquire TL_WRITE/TL_WRITE_ALLOW_READ were woken up (as table was still write locked by the first thread) so we ended up with a deadlock. This patch solves this problem by ensuring that thread which already has write lock on the table won't wait when it tries to acquire second write lock on the same table. mysql-test/r/lock_sync.result: Added test case for bug #45143 "All connections hang on concurrent ALTER TABLE". mysql-test/t/lock_sync.test: Added test case for bug #45143 "All connections hang on concurrent ALTER TABLE". mysys/thr_lock.c: Ensured that thread can acquire write lock on the table without waiting if it already has write lock on it even if there are other threads holding write locks on this table (this is normal situation for, e.g., TL_WRITE_ALLOW_WRITE type of lock). Adjusted comments to better explain why it is OK to do so and added asserts to prevent introduction of scenarios in which this can cause problems.
2009-10-26 20:38:03 +01:00
#
# Locking related tests which use DEBUG_SYNC facility.
#
--source include/have_debug_sync.inc
# We need InnoDB to be able use TL_WRITE_ALLOW_WRITE type of locks in our tests.
--source include/have_innodb.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
# This test requires statement/mixed mode binary logging.
# Row-based mode puts weaker serializability requirements
# so weaker locks are acquired for it.
--source include/have_binlog_format_mixed_or_statement.inc
# Until bug#41971 'Thread state on embedded server is always "Writing to net"'
# is fixed this test can't be run on embedded version of server.
--source include/not_embedded.inc
Fix for bug #45143 "All connections hang on concurrent ALTER TABLE". Concurrent execution of statements which require non-table-level write locks on several instances of the same table (such as SELECT ... FOR UPDATE which uses same InnoDB table twice or a DML statement which invokes trigger which tries to update same InnoDB table directly and through stored function) and statements which required table-level locks on this table (e.g. LOCK TABLE ... WRITE, ALTER TABLE, ...) might have resulted in a deadlock. The problem occured when a thread tried to acquire write lock (TL_WRITE_ALLOW_WRITE) on the table but had to wait since there was a pending write lock (TL_WRITE, TL_WRITE_ALLOW_READ) on this table and we failed to detect that this thread already had another instance of write lock on it (so in fact we were trying to acquire recursive lock) because there was also another thread holding write lock on the table (also TL_WRITE_ALLOW_WRITE). When the latter thread released its lock neither the first thread nor the thread trying to acquire TL_WRITE/TL_WRITE_ALLOW_READ were woken up (as table was still write locked by the first thread) so we ended up with a deadlock. This patch solves this problem by ensuring that thread which already has write lock on the table won't wait when it tries to acquire second write lock on the same table. mysql-test/r/lock_sync.result: Added test case for bug #45143 "All connections hang on concurrent ALTER TABLE". mysql-test/t/lock_sync.test: Added test case for bug #45143 "All connections hang on concurrent ALTER TABLE". mysys/thr_lock.c: Ensured that thread can acquire write lock on the table without waiting if it already has write lock on it even if there are other threads holding write locks on this table (this is normal situation for, e.g., TL_WRITE_ALLOW_WRITE type of lock). Adjusted comments to better explain why it is OK to do so and added asserts to prevent introduction of scenarios in which this can cause problems.
2009-10-26 20:38:03 +01:00
# Save the initial number of concurrent sessions.
--source include/count_sessions.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
--echo #
--echo # Test how we handle locking in various cases when
--echo # we read data from MyISAM tables.
--echo #
--echo # In this test we mostly check that the SQL-layer correctly
--echo # determines the type of thr_lock.c lock for a table being
--echo # read.
--echo # I.e. that it disallows concurrent inserts when the statement
--echo # is going to be written to the binary log and therefore
--echo # should be serialized, and allows concurrent inserts when
--echo # such serialization is not necessary (e.g. when
--echo # the statement is not written to binary log).
--echo #
--echo # Force concurrent inserts to be performed even if the table
--echo # has gaps. This allows to simplify clean up in scripts
--echo # used below (instead of backing up table being inserted
--echo # into and then restoring it from backup at the end of the
--echo # script we can simply delete rows which were inserted).
set @old_concurrent_insert= @@global.concurrent_insert;
set @@global.concurrent_insert= 2;
select @@global.concurrent_insert;
--echo # Prepare playground by creating tables, views,
--echo # routines and triggers used in tests.
connect (con1, localhost, root,,);
connect (con2, localhost, root,,);
connection default;
--disable_warnings
drop table if exists t0, t1, t2, t3, t4, t5;
drop view if exists v1, v2;
drop procedure if exists p1;
drop procedure if exists p2;
drop procedure if exists p3;
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
drop function if exists f1;
drop function if exists f2;
drop function if exists f3;
drop function if exists f4;
drop function if exists f5;
drop function if exists f6;
drop function if exists f7;
drop function if exists f8;
drop function if exists f9;
drop function if exists f10;
drop function if exists f11;
drop function if exists f12;
drop function if exists f13;
drop function if exists f14;
drop function if exists f15;
drop function if exists f16;
drop function if exists f17;
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
--enable_warnings
create table t1 (i int primary key);
insert into t1 values (1), (2), (3), (4), (5);
create table t2 (j int primary key);
insert into t2 values (1), (2), (3), (4), (5);
create table t3 (k int primary key);
insert into t3 values (1), (2), (3);
create table t4 (l int primary key);
insert into t4 values (1);
create table t5 (l int primary key);
insert into t5 values (1);
create view v1 as select i from t1;
create view v2 as select j from t2 where j in (select i from t1);
create procedure p1(k int) insert into t2 values (k);
delimiter |;
create function f1() returns int
begin
declare j int;
select i from t1 where i = 1 into j;
return j;
end|
create function f2() returns int
begin
declare k int;
select i from t1 where i = 1 into k;
insert into t2 values (k + 5);
return 0;
end|
create function f3() returns int
begin
return (select i from t1 where i = 3);
end|
create function f4() returns int
begin
if (select i from t1 where i = 3) then
return 1;
else
return 0;
end if;
end|
create function f5() returns int
begin
insert into t2 values ((select i from t1 where i = 1) + 5);
return 0;
end|
create function f6() returns int
begin
declare k int;
select i from v1 where i = 1 into k;
return k;
end|
create function f7() returns int
begin
declare k int;
select j from v2 where j = 1 into k;
return k;
end|
create function f8() returns int
begin
declare k int;
select i from v1 where i = 1 into k;
insert into t2 values (k+5);
return k;
end|
create function f9() returns int
begin
update v2 set j=j+10 where j=1;
return 1;
end|
create function f10() returns int
begin
return f1();
end|
create function f11() returns int
begin
declare k int;
set k= f1();
insert into t2 values (k+5);
return k;
end|
create function f12(p int) returns int
begin
insert into t2 values (p);
return p;
end|
create function f13(p int) returns int
begin
return p;
end|
create procedure p2(inout p int)
begin
select i from t1 where i = 1 into p;
end|
create function f14() returns int
begin
declare k int;
call p2(k);
insert into t2 values (k+5);
return k;
end|
create function f15() returns int
begin
declare k int;
call p2(k);
return k;
end|
create function f16() returns int
begin
create temporary table if not exists temp1 (a int);
insert into temp1 select * from t1;
drop temporary table temp1;
return 1;
end|
create function f17() returns int
begin
declare j int;
select i from t1 where i = 1 into j;
call p3;
return 1;
end|
create procedure p3()
begin
create temporary table if not exists temp1 (a int);
insert into temp1 select * from t1;
drop temporary table temp1;
end|
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
create trigger t4_bi before insert on t4 for each row
begin
declare k int;
select i from t1 where i=1 into k;
set new.l= k+1;
end|
create trigger t4_bu before update on t4 for each row
begin
if (select i from t1 where i=1) then
set new.l= 2;
end if;
end|
create trigger t4_bd before delete on t4 for each row
begin
if !(select i from v1 where i=1) then
signal sqlstate '45000';
end if;
end|
create trigger t5_bi before insert on t5 for each row
begin
set new.l= f1()+1;
end|
create trigger t5_bu before update on t5 for each row
begin
declare j int;
call p2(j);
set new.l= j + 1;
end|
delimiter ;|
--echo #
--echo # Set common variables to be used by the scripts
--echo # called below.
--echo #
let $con_aux1= con1;
let $con_aux2= con2;
let $table= t1;
connection con1;
--echo # Cache all functions used in the tests below so statements
--echo # calling them won't need to open and lock mysql.proc table
--echo # and we can assume that each statement locks its tables
--echo # once during its execution.
--disable_result_log
show create procedure p1;
show create procedure p2;
show create procedure p3;
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
show create function f1;
show create function f2;
show create function f3;
show create function f4;
show create function f5;
show create function f6;
show create function f7;
show create function f8;
show create function f9;
show create function f10;
show create function f11;
show create function f12;
show create function f13;
show create function f14;
show create function f15;
show create function f16;
show create function f17;
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
--enable_result_log
connection default;
--echo #
--echo # 1. Statements that read tables and do not use subqueries.
--echo #
--echo #
--echo # 1.1 Simple SELECT statement.
--echo #
--echo # No locks are necessary as this statement won't be written
--echo # to the binary log and thanks to how MyISAM works SELECT
--echo # will see version of the table prior to concurrent insert.
let $statement= select * from t1;
let $restore_table= ;
--source include/check_concurrent_insert.inc
--echo #
--echo # 1.2 Multi-UPDATE statement.
--echo #
--echo # Has to take shared locks on rows in the table being read as this
--echo # statement will be written to the binary log and therefore should
--echo # be serialized with concurrent statements.
let $statement= update t2, t1 set j= j - 1 where i = j;
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 1.3 Multi-DELETE statement.
--echo #
--echo # The above is true for this statement as well.
let $statement= delete t2 from t1, t2 where i = j;
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 1.4 DESCRIBE statement.
--echo #
--echo # This statement does not really read data from the
--echo # target table and thus does not take any lock on it.
--echo # We check this for completeness of coverage.
lock table t1 write;
connection con1;
--echo # This statement should not be blocked.
--disable_result_log
describe t1;
--enable_result_log
connection default;
unlock tables;
--echo #
--echo # 1.5 SHOW statements.
--echo #
--echo # The above is true for SHOW statements as well.
lock table t1 write;
connection con1;
--echo # These statements should not be blocked.
# The below test for SHOW CREATE TABLE is disabled until bug 52593
# "SHOW CREATE TABLE is blocked if table is locked for write by another
# connection" is fixed.
--disable_parsing
show create table t1;
--enable_parsing
--disable_result_log
show keys from t1;
--enable_result_log
connection default;
unlock tables;
--echo #
--echo # 2. Statements which read tables through subqueries.
--echo #
--echo #
--echo # 2.1 CALL with a subquery.
--echo #
--echo # A strong lock is not necessary as this statement is not
--echo # written to the binary log as a whole (it is written
--echo # statement-by-statement).
let $statement= call p1((select i + 5 from t1 where i = 1));
let $restore_table= t2;
--source include/check_concurrent_insert.inc
--echo #
--echo # 2.2 CREATE TABLE with a subquery.
--echo #
--echo # Has to take a strong lock on the table being read as
--echo # this statement is written to the binary log and therefore
--echo # should be serialized with concurrent statements.
let $statement= create table t0 select * from t1;
let $restore_table= ;
--source include/check_no_concurrent_insert.inc
drop table t0;
let $statement= create table t0 select j from t2 where j in (select i from t1);
let $restore_table= ;
--source include/check_no_concurrent_insert.inc
drop table t0;
--echo #
--echo # 2.3 DELETE with a subquery.
--echo #
--echo # The above is true for this statement as well.
let $statement= delete from t2 where j in (select i from t1);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 2.4 MULTI-DELETE with a subquery.
--echo #
--echo # Same is true for this statement as well.
let $statement= delete t2 from t3, t2 where k = j and j in (select i from t1);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 2.5 DO with a subquery.
--echo #
--echo # A strong lock is not necessary as it is not logged.
let $statement= do (select i from t1 where i = 1);
let $restore_table= ;
--source include/check_concurrent_insert.inc
--echo #
--echo # 2.6 INSERT with a subquery.
--echo #
--echo # Has to take a strong lock on the table being read as
--echo # this statement is written to the binary log and therefore
--echo # should be serialized with concurrent inserts.
let $statement= insert into t2 select i+5 from t1;
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
let $statement= insert into t2 values ((select i+5 from t1 where i = 4));
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 2.7 LOAD DATA with a subquery.
--echo #
--echo # The above is true for this statement as well.
let $statement= load data infile '../../std_data/rpl_loaddata.dat' into table t2 (@a, @b) set j= @b + (select i from t1 where i = 1);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 2.8 REPLACE with a subquery.
--echo #
--echo # Same is true for this statement as well.
MDEV-7660 - MySQL WL#6671 "Improve scalability by not using thr_lock.c locks for InnoDB tables" Don't use thr_lock.c locks for InnoDB tables. Below is list of changes that were needed to implement this: - HANDLER OPEN acquireis MDL_SHARED_READ instead of MDL_SHARED - HANDLER READ calls external_lock() even if SE is not going to be locked by THR_LOCK - InnoDB lock wait timeouts are now honored which are much shorter by default than server lock wait timeouts (1 year vs 50 seconds) - with @@autocommit= 1 LOCK TABLES disables autocommit implicitely, though user still sees @@autocommt= 1 - the above starts implicit transaction - transactions started by LOCK TABLES are now rolled back on disconnect (previously everything was committed due to autocommit) - transactions started by LOCK TABLES are now rolled back by ROLLBACK (previously everything was committed due to autocommit) - it is now impossible to change BINLOG_FORMAT under LOCK TABLES (at least to statement) due to running transaction - LOCK TABLES WRITE is additionally handled by MDL - ...in contrast LOCK TABLES READ protection against DML is pure InnoDB - combining transactional and non-transactional tables under LOCK TABLES may cause rolled back changes in transactional table and "committed" changes in non-transactional table - user may disable innodb_table_locks, which will cause LOCK TABLES to be noop basically Removed tests for BUG#45143 and BUG#55930 which cover InnoDB + THR_LOCK. To operate properly these tests require code flow to go through THR_LOCK debug sync points, which is not the case after this patch. These tests are removed by WL#6671 as well. An alternative is to port them to different storage engine.
2016-05-06 11:44:07 +02:00
--echo # Suppress warnings for REPLACE ... SELECT
--disable_query_log
call mtr.add_suppression("Unsafe statement written to the binary log using statement format since BINLOG_FORMAT = STATEMENT");
--enable_query_log
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= replace into t2 select i+5 from t1;
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
let $statement= replace into t2 values ((select i+5 from t1 where i = 4));
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 2.9 SELECT with a subquery.
--echo #
--echo # Strong locks are not necessary as this statement is not written
--echo # to the binary log and thanks to how MyISAM works this statement
--echo # sees a version of the table prior to the concurrent insert.
let $statement= select * from t2 where j in (select i from t1);
let $restore_table= ;
--source include/check_concurrent_insert.inc
--echo #
--echo # 2.10 SET with a subquery.
--echo #
--echo # The same is true for this statement as well.
let $statement= set @a:= (select i from t1 where i = 1);
let $restore_table= ;
--source include/check_concurrent_insert.inc
--echo #
--echo # 2.11 SHOW with a subquery.
--echo #
--echo # And for this statement too.
let $statement= show tables from test where Tables_in_test = 't2' and (select i from t1 where i = 1);
let $restore_table= ;
--source include/check_concurrent_insert.inc
let $statement= show columns from t2 where (select i from t1 where i = 1);
let $restore_table= ;
--source include/check_concurrent_insert.inc
--echo #
--echo # 2.12 UPDATE with a subquery.
--echo #
--echo # Has to take a strong lock on the table being read as
--echo # this statement is written to the binary log and therefore
--echo # should be serialized with concurrent inserts.
let $statement= update t2 set j= j-10 where j in (select i from t1);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 2.13 MULTI-UPDATE with a subquery.
--echo #
--echo # Same is true for this statement as well.
let $statement= update t2, t3 set j= j -10 where j=k and j in (select i from t1);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 3. Statements which read tables through a view.
--echo #
--echo #
--echo # 3.1 SELECT statement which uses some table through a view.
--echo #
--echo # Since this statement is not written to the binary log and
--echo # an old version of the table is accessible thanks to how MyISAM
--echo # handles concurrent insert, no locking is necessary.
let $statement= select * from v1;
let $restore_table= ;
--source include/check_concurrent_insert.inc
let $statement= select * from v2;
let $restore_table= ;
--source include/check_concurrent_insert.inc
let $statement= select * from t2 where j in (select i from v1);
let $restore_table= ;
--source include/check_concurrent_insert.inc
let $statement= select * from t3 where k in (select j from v2);
let $restore_table= ;
--source include/check_concurrent_insert.inc
--echo #
--echo # 3.2 Statements which modify a table and use views.
--echo #
--echo # Since such statements are going to be written to the binary
--echo # log they need to be serialized against concurrent statements
--echo # and therefore should take strong locks on the data read.
let $statement= update t2 set j= j-10 where j in (select i from v1);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
let $statement= update t3 set k= k-10 where k in (select j from v2);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
let $statement= update t2, v1 set j= j-10 where j = i;
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
let $statement= update v2 set j= j-10 where j = 3;
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 4. Statements which read tables through stored functions.
--echo #
--echo #
--echo # 4.1 SELECT/SET with a stored function which does not
--echo # modify data and uses SELECT in its turn.
--echo #
--echo # There is no need to take strong locks on the table
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
--echo # being selected from in SF as the call to such function
--echo # won't get into the binary log.
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= select f1();
let $restore_table= ;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= set @a:= f1();
let $restore_table= ;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
--echo #
--echo # 4.2 INSERT (or other statement which modifies data) with
--echo # a stored function which does not modify data and uses
--echo # SELECT.
--echo #
--echo # Since such statement is written to the binary log it should
--echo # be serialized with concurrent statements affecting the data
--echo # it uses. Therefore it should take strong lock on the data
--echo # it reads.
let $statement= insert into t2 values (f1() + 5);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 4.3 SELECT/SET with a stored function which
--echo # reads and modifies data.
--echo #
--echo # Since a call to such function is written to the binary log,
--echo # it should be serialized with concurrent statements affecting
--echo # the data it uses. Hence, a strong lock on the data read
--echo # should be taken.
let $statement= select f2();
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
let $statement= set @a:= f2();
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 4.4. SELECT/SET with a stored function which does not
--echo # modify data and reads a table through subselect
--echo # in a control construct.
--echo #
--echo # Call to this function won't get to the
--echo # binary log and thus no strong lock is needed.
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= select f3();
let $restore_table= ;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= set @a:= f3();
let $restore_table= ;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= select f4();
let $restore_table= ;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= set @a:= f4();
let $restore_table= ;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
--echo #
--echo # 4.5. INSERT (or other statement which modifies data) with
--echo # a stored function which does not modify data and reads
--echo # the table through a subselect in one of its control
--echo # constructs.
--echo #
--echo # Since such statement is written to the binary log it should
--echo # be serialized with concurrent statements affecting data it
--echo # uses. Therefore it should take a strong lock on the data
--echo # it reads.
let $statement= insert into t2 values (f3() + 5);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
let $statement= insert into t2 values (f4() + 6);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 4.6 SELECT/SET which uses a stored function with
--echo # DML which reads a table via a subquery.
--echo #
--echo # Since call to such function is written to the binary log
--echo # it should be serialized with concurrent statements.
--echo # Hence reads should take a strong lock.
let $statement= select f5();
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
let $statement= set @a:= f5();
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 4.7 SELECT/SET which uses a stored function which
--echo # doesn't modify data and reads tables through
--echo # a view.
--echo #
--echo # Calls to such functions won't get into
--echo # the binary log and thus don't need strong
--echo # locks.
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= select f6();
let $restore_table= t2;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= set @a:= f6();
let $restore_table= t2;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= select f7();
let $restore_table= t2;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= set @a:= f7();
let $restore_table= t2;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
--echo #
--echo # 4.8 INSERT which uses stored function which
--echo # doesn't modify data and reads a table
--echo # through a view.
--echo #
--echo # Since such statement is written to the binary log and
--echo # should be serialized with concurrent statements affecting
--echo # the data it uses. Therefore it should take a strong lock on
--echo # the table it reads.
let $statement= insert into t3 values (f6() + 5);
let $restore_table= t3;
--source include/check_no_concurrent_insert.inc
let $statement= insert into t3 values (f7() + 5);
let $restore_table= t3;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 4.9 SELECT which uses a stored function which
--echo # modifies data and reads tables through a view.
--echo #
--echo # Since a call to such function is written to the binary log
--echo # it should be serialized with concurrent statements.
--echo # Hence, reads should take strong locks.
let $statement= select f8();
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
let $statement= select f9();
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 4.10 SELECT which uses a stored function which doesn't modify
--echo # data and reads a table indirectly, by calling another
--echo # function.
--echo #
--echo # Calls to such functions won't get into the binary
--echo # log and thus don't need to acquire strong locks.
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= select f10();
let $restore_table= ;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
--echo #
--echo # 4.11 INSERT which uses a stored function which doesn't modify
--echo # data and reads a table indirectly, by calling another
--echo # function.
--echo #
--echo # Since such statement is written to the binary log, it should
--echo # be serialized with concurrent statements affecting the data it
--echo # uses. Therefore it should take strong locks on data it reads.
let $statement= insert into t2 values (f10() + 5);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 4.12 SELECT which uses a stored function which modifies
--echo # data and reads a table indirectly, by calling another
--echo # function.
--echo #
--echo # Since a call to such function is written to the binary log
--echo # it should be serialized from concurrent statements.
--echo # Hence, read should take a strong lock.
let $statement= select f11();
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 4.13 SELECT that reads a table through a subquery passed
--echo # as a parameter to a stored function which modifies
--echo # data.
--echo #
--echo # Even though a call to this function is written to the
--echo # binary log, values of its parameters are written as literals.
--echo # So there is no need to acquire strong locks for tables used in
--echo # the subquery.
let $statement= select f12((select i+10 from t1 where i=1));
let $restore_table= t2;
--source include/check_concurrent_insert.inc
--echo #
--echo # 4.14 INSERT that reads a table via a subquery passed
--echo # as a parameter to a stored function which doesn't
--echo # modify data.
--echo #
--echo # Since this statement is written to the binary log it should
--echo # be serialized with concurrent statements affecting the data it
--echo # uses. Therefore it should take strong locks on the data it reads.
let $statement= insert into t2 values (f13((select i+10 from t1 where i=1)));
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 4.15 SELECT/SET with a stored function which
--echo # inserts data into a temporary table using
--echo # SELECT on t1.
--echo #
--echo # Since this statement is written to the binary log it should
--echo # be serialized with concurrent statements affecting the data it
--echo # uses. Therefore it should take strong locks on the data it reads.
let $statement= select f16();
let $restore_table= ;
--source include/check_no_concurrent_insert.inc
let $statement= set @a:= f16();
let $restore_table= ;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 4.16 SELECT/SET with a stored function which call procedure
--echo # which inserts data into a temporary table using
--echo # SELECT on t1.
--echo #
--echo # Since this statement is written to the binary log it should
--echo # be serialized with concurrent statements affecting the data it
--echo # uses. Therefore it should take strong locks on the data it reads.
let $statement= select f17();
let $restore_table= ;
--source include/check_no_concurrent_insert.inc
let $statement= set @a:= f17();
let $restore_table= ;
--source include/check_no_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
--echo #
--echo # 5. Statements that read tables through stored procedures.
--echo #
--echo #
--echo # 5.1 CALL statement which reads a table via SELECT.
--echo #
--echo # Since neither this statement nor its components are
--echo # written to the binary log, there is no need to take
--echo # strong locks on the data it reads.
let $statement= call p2(@a);
let $restore_table= ;
--source include/check_concurrent_insert.inc
--echo #
--echo # 5.2 Function that modifies data and uses CALL,
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
--echo # which reads a table through SELECT.
--echo #
--echo # Since a call to such function is written to the binary
--echo # log, it should be serialized with concurrent statements.
--echo # Hence, in this case reads should take strong locks on data.
let $statement= select f14();
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 5.3 SELECT that calls a function that doesn't modify data and
--echo # uses a CALL statement that reads a table via SELECT.
--echo #
--echo # Calls to such functions won't get into the binary
--echo # log and thus don't need to acquire strong locks.
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
let $statement= select f15();
let $restore_table= ;
--source include/check_concurrent_insert.inc
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
--echo #
--echo # 5.4 INSERT which calls function which doesn't modify data and
--echo # uses CALL statement which reads table through SELECT.
--echo #
--echo # Since such statement is written to the binary log it should
--echo # be serialized with concurrent statements affecting data it
--echo # uses. Therefore it should take strong locks on data it reads.
let $statement= insert into t2 values (f15()+5);
let $restore_table= t2;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 6. Statements that use triggers.
--echo #
--echo #
--echo # 6.1 Statement invoking a trigger that reads table via SELECT.
--echo #
--echo # Since this statement is written to the binary log it should
--echo # be serialized with concurrent statements affecting the data
--echo # it uses. Therefore, it should take strong locks on the data
--echo # it reads.
let $statement= insert into t4 values (2);
let $restore_table= t4;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 6.2 Statement invoking a trigger that reads table through
--echo # a subquery in a control construct.
--echo #
--echo # The above is true for this statement as well.
let $statement= update t4 set l= 2 where l = 1;
let $restore_table= t4;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 6.3 Statement invoking a trigger that reads a table through
--echo # a view.
--echo #
--echo # And for this statement.
let $statement= delete from t4 where l = 1;
let $restore_table= t4;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 6.4 Statement invoking a trigger that reads a table through
--echo # a stored function.
--echo #
--echo # And for this statement.
let $statement= insert into t5 values (2);
let $restore_table= t5;
--source include/check_no_concurrent_insert.inc
--echo #
--echo # 6.5 Statement invoking a trigger that reads a table through
--echo # stored procedure.
--echo #
--echo # And for this statement.
let $statement= update t5 set l= 2 where l = 1;
let $restore_table= t5;
--source include/check_no_concurrent_insert.inc
--echo # Clean-up.
drop function f1;
drop function f2;
drop function f3;
drop function f4;
drop function f5;
drop function f6;
drop function f7;
drop function f8;
drop function f9;
drop function f10;
drop function f11;
drop function f12;
drop function f13;
drop function f14;
drop function f15;
drop function f16;
drop function f17;
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
drop view v1, v2;
drop procedure p1;
drop procedure p2;
drop procedure p3;
Committing on behalf or Dmitry Lenev: Fix for bug #46947 "Embedded SELECT without FOR UPDATE is causing a lock", with after-review fixes. SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch tries to solve this problem by rethinking our approach to how we handle locking for SELECT and subqueries. Now we always set TL_READ_DEFAULT lock type for all cases when we read data. When at open_tables() time this lock is interpreted as TL_READ_NO_INSERT or TL_READ depending on whether this statement as a whole or call to function which uses particular table should be written to the binary log or not (if yes then statement should be properly serialized with concurrent statements and stronger lock should be acquired). Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. On of the patches for 5.0 broke this behaviour (which was not documented or tested), and started to use locking reads fora all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/log_event.cc: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/log_event.h: Since LEX::lock_option member was removed we no longer can rely on its value in Load_log_event::print_query() to determine that log event correponds to LOAD DATA CONCURRENT statement (this was not correct in all situations anyway). A new Load_log_event's member was introduced as a replacement. It is initialized at event object construction time and explicitly indicates whether LOAD DATA was concurrent. sql/sp_head.cc: sp_head::reset_lex(): Before parsing substatement reset part of parser state which needs this (e.g. set Yacc_state::m_lock_type to default value). sql/sql_acl.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing statement which won't update tables directly and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to Query_tables_list and TABLE_LIST objects. sql/sql_base.h: - Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_lex.cc: - Removed LEX::lock_option and st_select_lex::lock_option members. Places in parser that were using them now use Yacc_state::m_lock_type instead. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. It is now reset by Query_tables_list::reset_query_tables_list() method. sql/sql_lex.h: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - To emphasize that LEX::sql_command member is used during process of opening and locking of tables it was moved to Query_tables_list class. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. sql/sql_load.cc: Load_log_event constructor now requires a parameter that indicates whether LOAD DATA is concurrent. sql/sql_parse.cc: LEX::lock_option was replaced with Yacc_state::m_lock_type. And instead of resetting the latter implicitly in mysql_init_multi_delete() we do it explicitly in the places in parser which call this function. sql/sql_priv.h: - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method added flag for HIGH_PRIORITY option. sql/sql_select.cc: Changed code not to rely on LEX::lock_option to determine that it is high-priority SELECT. It was replaced with Yacc_state::m_lock_type which is accessible only at parse time. So instead of LEX::lock_option we now rely on a newly introduced flag for st_select_lex::options - SELECT_HIGH_PRIORITY. sql/sql_show.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed. sql/sql_table.cc: Since LEX::reset_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore value of this member when this method is called by mysql_admin_table(), to make this code safe for re-execution. sql/sql_trigger.cc: Since LEX::reset_n_backup_query_tables_list() now also resets LEX::sql_command member (as it became part of Query_tables_list class) we have to restore it in cases when while working with proxy Query_table_list we assume that LEX::sql_command still corresponds to original SQL command being executed (for example, when we are logging statement to the binary log while having Query_tables_list reset and backed up). sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to Query_tables_list and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_yacc.yy: - Removed st_select_lex::lock_option member as there is no real need for per-SELECT lock type (HIGH_PRIORITY option should apply to the whole statement. FOR UPDATE/LOCK IN SHARE MODE clauses can be handled without this member). The main effect which was achieved by introduction of this member, i.e. using TL_READ_DEFAULT lock type for subqueries, is now achieved by setting LEX::lock_option (or rather its replacement - Yacc_state::m_lock_type) to TL_READ_DEFAULT in almost all cases. - Replaced LEX::lock_option with Yacc_state::m_lock_type in order to emphasize that this value is relevant only during parsing. Unlike for LEX::lock_option the default value for Yacc_state::m_lock_type is TL_READ_DEFAULT. Note that for cases when it is OK to take a "weak" read lock (e.g. simple SELECT) this lock type will be converted to TL_READ at open_tables() time. So this change won't cause negative change in behavior for such statements. OTOH this change ensures that, for example, for SELECTs which are used in stored functions TL_READ_NO_INSERT lock is taken when necessary and as result calls to such stored functions can be written to the binary log with correct serialization. - To be able more easily distinguish high-priority SELECTs in st_select_lex::print() method we now use new flag in st_select_lex::options bit-field.
2010-04-28 12:04:11 +02:00
drop table t1, t2, t3, t4, t5;
disconnect con1;
disconnect con2;
set @@global.concurrent_insert= @old_concurrent_insert;
--echo #
--echo # Bug#50821 Deadlock between LOCK TABLES and ALTER TABLE
--echo #
--disable_warnings
DROP TABLE IF EXISTS t1, t2;
--enable_warnings
CREATE TABLE t1(id INT);
CREATE TABLE t2(id INT);
connect (con2, localhost, root);
START TRANSACTION;
SELECT * FROM t1;
connection default;
--echo # Sending:
--send ALTER TABLE t1 ADD COLUMN j INT
connection con2;
let $wait_condition=
SELECT COUNT(*) = 1 FROM information_schema.processlist
Part of fix for bug#52044 "FLUSH TABLES WITH READ LOCK and FLUSH TABLES <list> WITH READ LOCK are incompatible" to be pushed as separate patch. Replaced thread state name "Waiting for table", which was used by threads waiting for a metadata lock or table flush, with a set of names which better reflect types of resources being waited for. Also replaced "Table lock" thread state name, which was used by threads waiting on thr_lock.c table level lock, with more elaborate "Waiting for table level lock", to make it more consistent with other thread state names. Updated test cases and their results according to these changes. Fixed sys_vars.query_cache_wlock_invalidate_func test to not to wait for timeout of wait_condition.inc script. mysql-test/r/query_cache.result: Added test coverage for query_cache_wlock_invalidate behavior for implicitly locked tables. mysql-test/suite/sys_vars/r/query_cache_wlock_invalidate_func.result: Fixed sys_vars.query_cache_wlock_invalidate_func test to not to wait for timeout of wait_condition.inc script. Reverted changes to test which introduced timeout and replaced waiting condition with a more appropriate one. Test coverage for query_cache_wlock_invalidate behavior for implicitly locked tables was added to query_cache.test. mysql-test/suite/sys_vars/t/query_cache_wlock_invalidate_func.test: Fixed sys_vars.query_cache_wlock_invalidate_func test to not to wait for timeout of wait_condition.inc script. Reverted changes to test which introduced timeout and replaced waiting condition with a more appropriate one. Test coverage for query_cache_wlock_invalidate behavior for implicitly locked tables was added to query_cache.test. mysql-test/t/query_cache.test: Added test coverage for query_cache_wlock_invalidate behavior for implicitly locked tables. mysys/thr_lock.c: Replaced "Table lock" thread state name, which was used by threads waiting on thr_lock.c table level lock, with more elaborate "Waiting for table level lock", to make it consistent with thread state names which are used while waiting for metadata locks and table flush. sql/mdl.cc: Replaced thread state name "Waiting for table", which was used by threads waiting for a metadata lock or table flush, with a set of names which better reflect types of resources being waited for. To implement this: - Adjusted MDL_wait::timed_wait() to take thread state name as parameter. - Introduced method of MDL_key class which allows to get thread state name to be used while waiting for resource corresponding to the key and changed code to use it. Added array translating namespaces to thread state names as part of this change. sql/mdl.h: To implement this: - Adjusted MDL_wait::timed_wait() to take thread state name as parameter. - Introduced method of MDL_key class which allows to get thread state name to be used while waiting for resource corresponding to the key and changed code to use it. Added array translating namespaces to thread state names as part of this change. sql/sql_base.cc: Replaced thread state name "Waiting for table", which was used by threads waiting for table flush, with a more elaborate "Waiting for table flush".
2010-08-06 13:29:37 +02:00
WHERE state = "Waiting for table metadata lock"
AND info = "ALTER TABLE t1 ADD COLUMN j INT";
--source include/wait_condition.inc
--echo # This used to cause a deadlock.
INSERT INTO t2 SELECT * FROM t1;
COMMIT;
connection default;
--echo # Reaping ALTER TABLE t1 ADD COLUMN j INT
--reap
DROP TABLE t1, t2;
disconnect con2;
--echo #
--echo # Bug#51391 Deadlock involving events during rqg_info_schema test
--echo #
CREATE EVENT e1 ON SCHEDULE EVERY 5 HOUR DO SELECT 1;
CREATE EVENT e2 ON SCHEDULE EVERY 5 HOUR DO SELECT 2;
connect(con1, localhost, root);
SET DEBUG_SYNC="before_lock_tables_takes_lock SIGNAL drop WAIT_FOR query";
--echo # Sending:
--send DROP EVENT e1;
connection default;
SET DEBUG_SYNC="now WAIT_FOR drop";
SELECT name FROM mysql.event, INFORMATION_SCHEMA.GLOBAL_VARIABLES
WHERE definer = VARIABLE_VALUE;
SET DEBUG_SYNC="now SIGNAL query";
connection con1;
--echo # Reaping: DROP EVENT t1
--reap
disconnect con1;
--source include/wait_until_disconnected.inc
connection default;
DROP EVENT e2;
SET DEBUG_SYNC="RESET";
--echo #
--echo # Bug#57130 crash in Item_field::print during SHOW CREATE TABLE or VIEW
--echo #
--disable_warnings
DROP TABLE IF EXISTS t1;
DROP VIEW IF EXISTS v1;
DROP FUNCTION IF EXISTS f1;
--enable_warnings
CREATE TABLE t1(a INT);
CREATE FUNCTION f1() RETURNS INTEGER RETURN 1;
CREATE VIEW v1 AS SELECT * FROM t1 WHERE f1() = 1;
DROP FUNCTION f1;
connect(con2, localhost, root);
connect (con1, localhost, root);
# Need to trigger this sync point at least twice in order to
# get valgrind test failures without the patch
SET DEBUG_SYNC= 'open_tables_after_open_and_process_table SIGNAL opened WAIT_FOR dropped EXECUTE 2';
--echo # Sending:
--send SHOW CREATE VIEW v1
connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR opened';
SET DEBUG_SYNC= 'now SIGNAL dropped';
SET DEBUG_SYNC= 'now WAIT_FOR opened';
--echo # Sending:
--send FLUSH TABLES t1
connection default;
--echo # Waiting for FLUSH TABLES to be blocked.
let $wait_condition= SELECT COUNT(*)=1 FROM information_schema.processlist
WHERE state= 'Waiting for table metadata lock' AND info= 'FLUSH TABLES t1';
--source include/wait_condition.inc
SET DEBUG_SYNC= 'now SIGNAL dropped';
connection con1;
--echo # Reaping: SHOW CREATE VIEW v1
--reap
connection con2;
--echo # Reaping: FLUSH TABLES
--reap
connection default;
SET DEBUG_SYNC= 'RESET';
DROP VIEW v1;
DROP TABLE t1;
disconnect con1;
disconnect con2;
MDEV-11227 - mysqlimport -l doesn't issue UNLOCK TABLES Implementation of MDEV-7660 introduced unwanted incompatible change: modifications under LOCK TABLES with autocommit enabled are rolled back on disconnect. Previously everything was committed, because LOCK TABLES didn't adjust autocommit setting. This patch restores original behavior by reverting some changes done in MDEV-7660: - sql/sql_parse.cc: do not reset autocommit on LOCK TABLES - sql/sql_base.cc: do not set autocommit on UNLOCK TABLES - test cases: main.lock_tables_lost_commit, main.partition_explicit_prune, rpl.rpl_switch_stm_row_mixed, tokudb.nested_txn_implicit_commit, tokudb_bugs.db806 But it makes InnoDB tables under LOCK TABLES ... READ [LOCAL] not protected against DML. To restore protection some changes from WL#6671 were merged, specifically MDL_SHARED_READ_ONLY and test cases. WL#6671 merge highlights: - Not all tests merged. - In MySQL LOCK TABLES ... READ acquires MDL_SHARED_READ_ONLY for all engines, in MariaDB MDL_SHARED_READ is always acquired first and then upgraded to MDL_SHARED_READ_ONLY for InnoDB only. - The above allows us to omit MDL_SHARED_WRITE_LOW_PRIO implementation in MariaDB, which is rather useless with InnoDB. In MySQL it is needed to preserve locking behavior between low priority writes and LOCK TABLES ... READ for non-InnoDB engines (covered by sys_vars.sql_low_priority_updates_func). - Omitted HA_NO_READ_LOCAL_LOCK, we rely on lock_count() instead. - Omitted "piglets": in MariaDB stream of DML against InnoDB table may lead to concurrent LOCK TABLES ... READ starvation. - HANDLER ... OPEN acquires MDL_SHARED_READ instead of MDL_SHARED in MariaDB. - Omitted SNRW->X MDL lock upgrade for IMPORT/DISCARD TABLESPAECE under LOCK TABLES. - Omitted strong locks for views, triggers and SP under LOCK TABLES. - Omitted IX schema lock for LOCK TABLES READ. - Omitted deadlock weight juggling for LOCK TABLES. Full WL#6671 merge status: - innodb.innodb-lock: fully merged - main.alter_table: not merged due to different HANDLER solution - main.debug_sync: fully merged - main.handler_innodb: not merged due to different HANDLER solution - main.handler_myisam: not merged due to different HANDLER solution - main.innodb_mysql_lock: fully merged - main.insert_notembedded: fully merged - main.lock: not merged (due to no strong locks for views) - main.lock_multi: not merged - main.lock_sync: fully merged (partially in MDEV-7660) - main.mdl_sync: not merged - main.partition_debug_sync: not merged due to different HANDLER solution - main.status: fully merged - main.view: fully merged - perfschema.mdl_func: not merged (no such test in MariaDB) - perfschema.table_aggregate_global_2u_2t: not merged (didn't fail in MariaDB) - perfschema.table_aggregate_global_2u_3t: not merged (didn't fail in MariaDB) - perfschema.table_aggregate_global_4u_2t: not merged (didn't fail in MariaDB) - perfschema.table_aggregate_global_4u_3t: not merged (didn't fail in MariaDB) - perfschema.table_aggregate_hist_2u_2t: not merged (didn't fail in MariaDB) - perfschema.table_aggregate_hist_2u_3t: not merged (didn't fail in MariaDB) - perfschema.table_aggregate_hist_4u_2t: not merged (didn't fail in MariaDB) - perfschema.table_aggregate_hist_4u_3t: not merged (didn't fail in MariaDB) - perfschema.table_aggregate_thread_2u_2t: not merged (didn't fail in MariaDB) - perfschema.table_aggregate_thread_2u_3t: not merged (didn't fail in MariaDB) - perfschema.table_aggregate_thread_4u_2t: not merged (didn't fail in MariaDB) - perfschema.table_aggregate_thread_4u_3t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_global_2u_2t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_global_2u_3t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_global_4u_2t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_global_4u_3t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_hist_2u_2t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_hist_2u_3t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_hist_4u_2t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_hist_4u_3t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_thread_2u_2t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_thread_2u_3t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_thread_4u_2t: not merged (didn't fail in MariaDB) - perfschema.table_lock_aggregate_thread_4u_3t: not merged (didn't fail in MariaDB) - sys_vars.sql_low_priority_updates_func: not merged - include/thr_rwlock.h: not merged, rw_pr_lock_assert_write_owner and rw_pr_lock_assert_not_write_owner are macros in MariaDB - sql/handler.h: not merged (HA_NO_READ_LOCAL_LOCK) - sql/mdl.cc: partially merged (MDL_SHARED_READ_ONLY only) - sql/mdl.h: partially merged (MDL_SHARED_READ_ONLY only) - sql/lock.cc: fully merged - sql/sp_head.cc: not merged - sql/sp_head.h: not merged - sql/sql_base.cc: partially merged (MDL_SHARED_READ_ONLY only) - sql/sql_base.h: not merged - sql/sql_class.cc: fully merged - sql/sql_class.h: fully merged - sql/sql_handler.cc: merged partially (different solution in MariaDB) - sql/sql_parse.cc: partially merged, mostly omitted low priority write part - sql/sql_reload.cc: not merged comment change - sql/sql_table.cc: not merged SNRW->X upgrade for IMPORT/DISCARD TABLESPACE - sql/sql_view.cc: not merged - sql/sql_yacc.yy: not merged (MDL_SHARED_WRITE_LOW_PRIO, MDL_SHARED_READ_ONLY) - sql/table.cc: not merged (MDL_SHARED_WRITE_LOW_PRIO) - sql/table.h: not merged (MDL_SHARED_WRITE_LOW_PRIO) - sql/trigger.cc: not merged - storage/innobase/handler/ha_innodb.cc: merged store_lock()/lock_count() changes (in MDEV-7660), didn't merge HA_NO_READ_LOCAL_LOCK - storage/innobase/handler/ha_innodb.h: fully merged in MDEV-7660 - storage/myisammrg/ha_myisammrg.cc: not merged comment change - storage/perfschema/table_helper.cc: not merged (no MDL support in MariaDB PFS) - unittest/gunit/mdl-t.cc: not merged - unittest/gunit/mdl_sync-t.cc: not merged MariaDB specific changes: - handler.heap: different HANDLER solution, MDEV-7660 - handler.innodb: different HANDLER solution, MDEV-7660 - handler.interface: different HANDLER solution, MDEV-7660 - handler.myisam: different HANDLER solution, MDEV-7660 - main.mdl_sync: MDEV-7660 specific changes - main.partition_debug_sync: removed test due to different HANDLER solution, MDEV-7660 - main.truncate_coverage: removed test due to different HANDLER solution, MDEV-7660 - mysql-test/include/mtr_warnings.sql: additional cleanup, MDEV-7660 - mysql-test/lib/v1/mtr_report.pl: additional cleanup, MDEV-7660 - plugin/metadata_lock_info/metadata_lock_info.cc: not in MySQL - sql/sql_handler.cc: MariaDB specific fix for mysql_ha_read(), MDEV-7660
2016-12-08 11:20:46 +01:00
--echo #
--echo # Bug#28587 SELECT is blocked by INSERT waiting on read lock, even with low_priority_updates
--echo #
set low_priority_updates=1;
--disable_warnings
drop table if exists t1;
drop table if exists t2;
--enable_warnings
set debug_sync='RESET';
create table t1 (a int, b int, unique key t1$a (a));
create table t2 (j int, k int);
set debug_sync='after_lock_tables_takes_lock SIGNAL parked WAIT_FOR go';
--echo # Sending:
--send insert into t2 select * from t1;
connect (update,localhost,root,,);
connection update;
set debug_sync='now WAIT_FOR parked';
set low_priority_updates=1;
show variables like 'low_priority_updates';
let $ID= `select connection_id()`;
--send insert into t1 values (1, 2) ON DUPLICATE KEY UPDATE b = 2;
connect (select,localhost,root,,);
# we must wait till the insert opens and locks the table
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table level lock" and id = $ID;
--source include/wait_condition.inc
select * from t1;
set debug_sync='now SIGNAL go';
connection default;
disconnect update;
disconnect select;
--echo # Reaping INSERT SELECT
--reap
drop tables t1, t2;
set low_priority_updates=default;
set debug_sync='RESET';
--echo #
--echo # Additional test coverage for LOCK TABLES ... READ LOCAL
--echo # for InnoDB tables.
--echo #
--echo # Check that we correctly handle deadlocks which can occur
--echo # during metadata lock upgrade which happens when one tries
--echo # to use LOCK TABLES ... READ LOCAL for InnoDB tables.
--enable_connect_log
CREATE TABLE t1 (i INT) ENGINE=InnoDB;
CREATE TABLE t2 (j INT) ENGINE=InnoDB;
--echo # Execute LOCK TABLE READ LOCK which will pause after acquiring
--echo # SR metadata lock and before upgrading it to SRO lock.
SET DEBUG_SYNC="after_open_table_mdl_shared SIGNAL locked WAIT_FOR go";
--echo # Sending:
--send LOCK TABLE t1 READ LOCAL
connect (con1, localhost, root);
SET DEBUG_SYNC="now WAIT_FOR locked";
--echo # Execute RENAME TABLE which will try to acquire X lock.
--echo # Sending:
--send RENAME TABLE t1 TO t3, t2 TO t1, t3 TO t2
connect (con2, localhost, root);
--echo # Wait until RENAME TABLE is blocked.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
info = "RENAME TABLE t1 TO t3, t2 TO t1, t3 TO t2";
--source include/wait_condition.inc
--echo # Resume LOCK TABLE statement. It should try to
--echo # upgrade SR lock to SRO lock which will create
--echo # deadlock due to presence of pending X lock.
--echo # Deadlock should be detected and LOCK TABLES should
--echo # release its MDL and retry opening of tables.
SET DEBUG_SYNC="now SIGNAL go";
connection con1;
--echo # RENAME TABLE should be able to complete. Reap it.
--reap
connection default;
--echo # Reap LOCK TABLES.
--reap
--echo # Check that we see new version of table.
SELECT * FROM t1;
UNLOCK TABLES;
--echo # Clean-up.
SET DEBUG_SYNC="RESET";
disconnect con1;
disconnect con2;
DROP TABLES t1, t2;
--disable_connect_log
Fix for bug #45143 "All connections hang on concurrent ALTER TABLE". Concurrent execution of statements which require non-table-level write locks on several instances of the same table (such as SELECT ... FOR UPDATE which uses same InnoDB table twice or a DML statement which invokes trigger which tries to update same InnoDB table directly and through stored function) and statements which required table-level locks on this table (e.g. LOCK TABLE ... WRITE, ALTER TABLE, ...) might have resulted in a deadlock. The problem occured when a thread tried to acquire write lock (TL_WRITE_ALLOW_WRITE) on the table but had to wait since there was a pending write lock (TL_WRITE, TL_WRITE_ALLOW_READ) on this table and we failed to detect that this thread already had another instance of write lock on it (so in fact we were trying to acquire recursive lock) because there was also another thread holding write lock on the table (also TL_WRITE_ALLOW_WRITE). When the latter thread released its lock neither the first thread nor the thread trying to acquire TL_WRITE/TL_WRITE_ALLOW_READ were woken up (as table was still write locked by the first thread) so we ended up with a deadlock. This patch solves this problem by ensuring that thread which already has write lock on the table won't wait when it tries to acquire second write lock on the same table. mysql-test/r/lock_sync.result: Added test case for bug #45143 "All connections hang on concurrent ALTER TABLE". mysql-test/t/lock_sync.test: Added test case for bug #45143 "All connections hang on concurrent ALTER TABLE". mysys/thr_lock.c: Ensured that thread can acquire write lock on the table without waiting if it already has write lock on it even if there are other threads holding write locks on this table (this is normal situation for, e.g., TL_WRITE_ALLOW_WRITE type of lock). Adjusted comments to better explain why it is OK to do so and added asserts to prevent introduction of scenarios in which this can cause problems.
2009-10-26 20:38:03 +01:00
# Check that all connections opened by test cases in this file are really
# gone so execution of other tests won't be affected by their presence.
--source include/wait_until_count_sessions.inc