2630.39.1, 2630.28.29, 2630.34.3, 2630.34.2, 2630.34.1, 2630.29.29,
2630.29.28, 2630.31.1, 2630.28.13, 2630.28.10, 2617.23.14 and
some other minor revisions.
This patch implements:
WL#4264 "Backup: Stabilize Service Interface" -- all the
server prerequisites except si_objects.{h,cc} themselves (they can
be just copied over, when needed).
WL#4435: Support OUT-parameters in prepared statements.
(and all issues in the initial patches for these two
tasks, that were discovered in pushbuild and during testing).
Bug#39519: mysql_stmt_close() should flush all data
associated with the statement.
After execution of a prepared statement, send OUT parameters of the invoked
stored procedure, if any, to the client.
When using the binary protocol, send the parameters in an additional result
set over the wire. When using the text protocol, assign out parameters to
the user variables from the CALL(@var1, @var2, ...) specification.
The following refactoring has been made:
- Protocol::send_fields() was renamed to Protocol::send_result_set_metadata();
- A new Protocol::send_result_set_row() was introduced to incapsulate
common functionality for sending row data.
- Signature of Protocol::prepare_for_send() was changed: this operation
does not need a list of items, the number of items is fully sufficient.
The following backward incompatible changes have been made:
- CLIENT_MULTI_RESULTS is now enabled by default in the client;
- CLIENT_PS_MULTI_RESUTLS is now enabled by default in the client.
include/mysql.h:
Add a new flag to MYSQL_METHODS::flush_use_result
function pointer. This flag determines if all results
should be flushed or only the first one:
- if flush_all_results is TRUE, then cli_flush_use_result()
will read/flush all pending results. I.e. it will read
all packets while server status attribute indicates that
there are more results. This is a new semantic, required
to fix the bug.
- if flush_all_results is FALSE, the old sematic
is preserved -- i.e. cli_flush_use_result() reads data
until first EOF-packet.
include/mysql.h.pp:
Update the ABI with new calls (compatible changes).
include/mysql_com.h:
Add CLIENT_PS_OUT_PARAMS -- a client capability indicating that the client supportsю
libmysql/libmysql.c:
Add mysql_stmt_next_result() -- analogue of mysql_next_result() for binary protocol.
Fix a minor bug in alloc_fields() -- not all members were copied over,
and some only shallow-copied (catalog).
Flush all results in mysql_stmt_close() (Bug#39519).
libmysqld/lib_sql.cc:
Rename send_fields() -> send_result_set_metadata().
Refactoring: change prepare_for_send() so that it accepts only
what it really needs -- a number of elements in the list.
mysql-test/r/ps.result:
Update results: WL#4435.
mysql-test/t/ps.test:
WL#4435: A test case for an SQL-part of the problem.
sql-common/client.c:
Bug#39519.
Implement new functionality in cli_flush_use_result():
if flush_all_delete is TRUE, then it should read/flush
all pending results.
sql/Makefile.am:
Add a new header sql_prepare.h to the list
of build headers.
sql/events.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/handler.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/mysql_priv.h:
Move sql_prepare.cc-specific declarations to a new
header - sql_prepare.h.
sql/procedure.h:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/protocol.cc:
Move the logic responsible for sending of one result
set row to the Protocol class. Define a template
for end-of-statement action.
Refactoring: change prepare_for_send() so that it accepts
only what it really needs -- a number of elements in the list.
Rename send_fields() to send_result_set_metadata().
sql/protocol.h:
Update with new declarations (WL#4435).
Rename send_fields() -> send_result_set_metadata().
prepare_for_send() only needs the number of columns to send,
and doesn't use the item list - update signature to require
only what's needed.
Add a new protocol type -- Protocol_local.
sql/repl_failsafe.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/slave.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_acl.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_base.cc:
Include sql_prepare.h (for Reprepare_observer).
sql/sql_cache.cc:
Extend the query cache flags block to be able
to store a numeric id for the result format,
not just a flag binary/non-binary.
sql/sql_class.cc:
Update to use the rename of Protocol::send_fields()
to Protocol::send_result_set_metadata().
Use Protocol::send_one_result_set_row().
sql/sql_class.h:
Move the declaration of Reprepare_observer to the
new header - sql_prepare.h.
Update to the new signature of class Protocol::send_fields().
sql/sql_connect.cc:
Use a protocol template method instead of
raw NET layer API at the end of a statement.
sql/sql_cursor.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_error.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_handler.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
Use new method Protocol::send_one_result_set_row().
sql/sql_help.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_lex.cc:
Initialize multi_statements variable.
Add a handy constant for empty lex
string.
sql/sql_lex.h:
Add a separate member for a standalone
parsing option - multi-statements support.
sql/sql_list.cc:
sql_list.h is a standalone header now,
no need to include mysql_priv.h.
sql/sql_list.h:
Make sql_list.h a stand-alone header.
sql/sql_parse.cc:
Include sql_prepare.h for prepared
statements- related declarations.
Use a new Protocol template method to end
each statement (send OK, EOF or ERROR to
the client).
sql/sql_prepare.cc:
Implement Execute Direct API (WL#4264),
currently unused. It will be used by the service
interface (Backup).
Use a new header - sql_prepare.h.
Add support for OUT parameters in the
binary and text protocol (prepared statements
only).
sql/sql_prepare.h:
Add a new header to contain (for now)
all prepared statement- external
related declarations.
sql/sql_profile.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_repl.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_select.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_show.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_string.h:
Add a way to convert a String to LEX_STRING.
sql/sql_table.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_update.cc:
Remove an extraneous my_error(). The error
is already reported in update_non_unique_table_error().
sql/sql_yacc.yy:
Support for multi-statements is an independent
property of parsing, not derived from
the protocol type.
tests/mysql_client_test.c:
Add tests for WL#4435 (binary protocol).
2630.39.1, 2630.28.29, 2630.34.3, 2630.34.2, 2630.34.1, 2630.29.29,
2630.29.28, 2630.31.1, 2630.28.13, 2630.28.10, 2617.23.14 and
some other minor revisions.
This patch implements:
WL#4264 "Backup: Stabilize Service Interface" -- all the
server prerequisites except si_objects.{h,cc} themselves (they can
be just copied over, when needed).
WL#4435: Support OUT-parameters in prepared statements.
(and all issues in the initial patches for these two
tasks, that were discovered in pushbuild and during testing).
Bug#39519: mysql_stmt_close() should flush all data
associated with the statement.
After execution of a prepared statement, send OUT parameters of the invoked
stored procedure, if any, to the client.
When using the binary protocol, send the parameters in an additional result
set over the wire. When using the text protocol, assign out parameters to
the user variables from the CALL(@var1, @var2, ...) specification.
The following refactoring has been made:
- Protocol::send_fields() was renamed to Protocol::send_result_set_metadata();
- A new Protocol::send_result_set_row() was introduced to incapsulate
common functionality for sending row data.
- Signature of Protocol::prepare_for_send() was changed: this operation
does not need a list of items, the number of items is fully sufficient.
The following backward incompatible changes have been made:
- CLIENT_MULTI_RESULTS is now enabled by default in the client;
- CLIENT_PS_MULTI_RESUTLS is now enabled by default in the client.
The original code comes, as far as I know, from Google (Mark Callaghan's team) with additional work from Percona, Ourdelta and Weldon Whipple.
This code provides the same functionallity, but with a lot of changes to make it faster and better fit the MariaDB infrastucture.
Added new status variables:
- Com_show_client_statistics, Com_show_index_statistics, Com_show_table_statistics, Com_show_user_statistics
- Access_denied_errors, Busy_time (clock time), Binlog_bytes_written, Cpu_time, Empty_queries, Rows_sent, Rows_read
Added new variable / startup option 'userstat' to control if user statistics should be enabled or not
Added my_getcputime(); Returns cpu time used by this thread.
New FLUSH commands:
- FLUSH SLOW QUERY LOG
- FLUSH TABLE_STATISTICS
- FLUSH INDEX_STATISTICS
- FLUSH USER_STATISTICS
- FLUSH CLIENT_STATISTICS
New SHOW commands:
- SHOW CLIENT_STATISTICS
- SHOW USER_STATISTICS
- SHOW TABLE_STATISTICS
- SHOW INDEX_STATISTICS
New Information schemas:
- CLIENT_STATISTICS
- USER_STATISTICS
- INDEX_STATISTICS
- TABLE_STATISTICS
Added support for all new flush commands to mysqladmin
Added handler::ha_... wrappers for all handler read calls to do statistics counting
- Changed all code to use new ha_... calls
- Count number of read rows, changed rows and rows read trough an index
Added counting of number of bytes sent to binary log (status variable Binlog_bytes_written)
Added counting of access denied errors (status variable Access_denied_erors)
Bugs fixed:
- Fixed bug in add_to_status() and add_diff_to_status() where longlong variables where threated as long
- CLOCK_GETTIME was not propely working on Linuxm
client/mysqladmin.cc:
Added support for all new flush commmands and some common combinations:
flush-slow-log
flush-table-statistics
flush-index-statistics
flush-user-statistics
flush-client-statistics
flush-all-status
flush-all-statistics
configure.in:
Added checking if clock_gettime needs the librt.
(Fixes Bug #37639 clock_gettime is never used/enabled in Linux/Unix)
include/my_sys.h:
Added my_getcputime()
include/mysql_com.h:
Added LIST_PROCESS_HOST_LEN & new REFRESH target defines
mysql-test/r/information_schema.result:
New information schema tables added
mysql-test/r/information_schema_all_engines.result:
New information schema tables added
mysql-test/r/information_schema_db.result:
New information schema tables added
mysql-test/r/log_slow.result:
Added testing that flosh slow query logs is accepted
mysql-test/r/status_user.result:
Basic testing of user, client, table and index statistics
mysql-test/t/log_slow.test:
Added testing that flosh slow query logs is accepted
mysql-test/t/status_user-master.opt:
Ensure that we get a fresh restart before running status_user.test
mysql-test/t/status_user.test:
Basic testing of user, client, table and index statistics
mysys/my_getsystime.c:
Added my_getcputime()
Returns cpu time used by this thread.
sql/authors.h:
Updated authors to have core and original MySQL developers first.
sql/event_data_objects.cc:
Updated call to mysql_reset_thd_for_next_command()
sql/event_db_repository.cc:
Changed to use new ha_... calls
sql/filesort.cc:
Changed to use new ha_... calls
sql/ha_partition.cc:
Changed to use new ha_... calls
Fixed comment syntax
sql/handler.cc:
Changed to use new ha_... calls
Reset table statistics
Added code to update global table and index status
Added counting of rows changed
sql/handler.h:
Added table and index statistics variables
Added function reset_statistics()
Added handler::ha_... wrappers for all handler read calls to do statistics counting
Protected all normal read calls to ensure we use the new calls in the server.
Made ha_partition a friend class so that partition code can call the old read functions
sql/item_subselect.cc:
Changed to use new ha_... calls
sql/lex.h:
Added keywords for new information schema tables and flush commands
sql/log.cc:
Added flush_slow_log()
Added counting of number of bytes sent to binary log
Removed not needed test of thd (It's used before, so it's safe to use)
Added THD object to MYSQL_BIN_LOG::write_cache() to simplify statistics counting
sql/log.h:
Added new parameter to write_cache()
Added flush_slow_log() functions.
sql/log_event.cc:
Updated call to mysql_reset_thd_for_next_command()
Changed to use new ha_... calls
sql/log_event_old.cc:
Updated call to mysql_reset_thd_for_next_command()
Changed to use new ha_... calls
sql/mysql_priv.h:
Updated call to mysql_reset_thd_for_next_command()
Added new statistics functions and variables needed by these.
sql/mysqld.cc:
Added new statistics variables and structures to handle these
Added new status variables:
- Com_show_client_statistics, Com_show_index_statistics, Com_show_table_statistics, Com_show_user_statistics
- Access_denied_errors, Busy_time (clock time), Binlog_bytes_written, Cpu_time, Empty_queries, Rows_set, Rows_read
Added new option 'userstat' to control if user statistics should be enabled or not
sql/opt_range.cc:
Changed to use new ha_... calls
sql/opt_range.h:
Changed to use new ha_... calls
sql/opt_sum.cc:
Changed to use new ha_... calls
sql/records.cc:
Changed to use new ha_... calls
sql/set_var.cc:
Added variable 'userstat'
sql/sp.cc:
Changed to use new ha_... calls
sql/sql_acl.cc:
Changed to use new ha_... calls
Added counting of access_denied_errors
sql/sql_base.cc:
Added call to statistics functions
sql/sql_class.cc:
Added usage of org_status_var, to store status variables at start of command
Added functions THD::update_stats(), THD::update_all_stats()
Fixed bug in add_to_status() and add_diff_to_status() where longlong variables where threated as long
sql/sql_class.h:
Added new status variables to status_var
Moved variables that was not ulong in status_var last.
Added variables to THD for storing temporary values during statistics counting
sql/sql_connect.cc:
Variables and functions to calculate user and client statistics
Added counting of access_denied_errors and lost_connections
sql/sql_cursor.cc:
Changed to use new ha_... calls
sql/sql_handler.cc:
Changed to use new ha_... calls
sql/sql_help.cc:
Changed to use new ha_... calls
sql/sql_insert.cc:
Changed to use new ha_... calls
sql/sql_lex.h:
Added SQLCOM_SHOW_USER_STATS, SQLCOM_SHOW_TABLE_STATS, SQLCOM_SHOW_INDEX_STATS, SQLCOM_SHOW_CLIENT_STATS
sql/sql_parse.cc:
Added handling of:
- SHOW CLIENT_STATISTICS
- SHOW USER_STATISTICS
- SHOW TABLE_STATISTICS
- SHOW INDEX_STATISTICS
Added handling of new FLUSH commands:
- FLUSH SLOW QUERY LOGS
- FLUSH TABLE_STATISTICS
- FLUSH INDEX_STATISTICS
- FLUSH USER_STATISTICS
- FLUSH CLIENT_STATISTICS
Added THD parameter to mysql_reset_thd_for_next_command()
Added initialization and calls to user statistics functions
Added increment of statistics variables empty_queries, rows_sent and access_denied_errors.
Added counting of cpu time per query
sql/sql_plugin.cc:
Changed to use new ha_... calls
sql/sql_prepare.cc:
Updated call to mysql_reset_thd_for_next_command()
sql/sql_select.cc:
Changed to use new ha_... calls
Indentation changes
sql/sql_servers.cc:
Changed to use new ha_... calls
sql/sql_show.cc:
Added counting of access denied errors
Added function for new information schema tables:
- CLIENT_STATISTICS
- USER_STATISTICS
- INDEX_STATISTICS
- TABLE_STATISTICS
Changed to use new ha_... calls
sql/sql_table.cc:
Changed to use new ha_... calls
sql/sql_udf.cc:
Changed to use new ha_... calls
sql/sql_update.cc:
Changed to use new ha_... calls
sql/sql_yacc.yy:
Add new show and flush commands
sql/structs.h:
Add name_length to KEY to avoid some strlen
Added cache_name to KEY for fast storage of keyvalue in cache
Added structs USER_STATS, TABLE_STATS, INDEX_STATS
Added function prototypes for statistics functions
sql/table.cc:
Store db+table+index name into keyinfo->cache_name
sql/table.h:
Added new information schema tables
sql/tztime.cc:
Changed to use new ha_... calls
table
The MERGE table storage engine does not support the HA_CAN_SQL_HANDLE feature
and any attempt to open the merge table will fail with ER_ILLEGAL_HA.
After an error occurred the tables that was opened must be closed again
or they will be left in an inconsistent state. However, the assumption
made in the code for closing and register handler tables was that only
one table will be opened, and this is not true for MERGE tables which
will cause multiple tables to open.
The next time a SELECT operation was issued on the merge table it
caused the system to freeze.
This patch fixes this issue by making sure that all tables which
are opened also are closed in the event of an error.
mysql-test/r/merge.result:
Added test case for bug 45781
mysql-test/t/merge.test:
Added test case for bug 45781
sql/sql_handler.cc:
* mysql_ha_open() was never ment to open more than one table. If we encounter more tables, we should
close all tables related to the current substatement and raise an exception.
table
The MERGE table storage engine does not support the HA_CAN_SQL_HANDLE feature
and any attempt to open the merge table will fail with ER_ILLEGAL_HA.
After an error occurred the tables that was opened must be closed again
or they will be left in an inconsistent state. However, the assumption
made in the code for closing and register handler tables was that only
one table will be opened, and this is not true for MERGE tables which
will cause multiple tables to open.
The next time a SELECT operation was issued on the merge table it
caused the system to freeze.
This patch fixes this issue by making sure that all tables which
are opened also are closed in the event of an error.
information schema tables are based on internal tmp tables which are removed
after each statement execution. So HANDLER comands can not be used with
information schema.
mysql-test/r/handler.result:
test result
mysql-test/t/handler.test:
test case
sql/sql_handler.cc:
information schema tables are based on internal tmp tables which are removed
after each statement execution. So HANDLER comands can not be used with
information schema.
information schema tables are based on internal tmp tables which are removed
after each statement execution. So HANDLER comands can not be used with
information schema.
Bug#41112: crash in mysql_ha_close_table/get_lock_data with alter table
The problem is that the server wasn't handling robustly failures
to re-open a table during a HANDLER .. READ statement. If the
table needed to be re-opened due to it's storage engine being
altered to one that doesn't support HANDLER, a reference (dangling
pointer) to a closed table could be left in place and accessed in
later attempts to fetch from the table using the handler. Also,
if the server failed to set a error message if the re-open
failed. These problems could lead to server crashes or hangs.
The solution is to remove any references to a closed table and
to set a error if reopening a table during a HANDLER .. READ
statement fails.
mysql-test/include/handler.inc:
Add test case for Bug#41110 and Bug#41112
mysql-test/r/handler_innodb.result:
Add test case result for Bug#41110 and Bug#41112
mysql-test/r/handler_myisam.result:
Add test case result for Bug#41110 and Bug#41112
sql/sql_handler.cc:
Remove redundant reopen check.
Set errors even if reopening table.
Reset TABLE_LIST::table reference when the table is closed.
Bug#41112: crash in mysql_ha_close_table/get_lock_data with alter table
The problem is that the server wasn't handling robustly failures
to re-open a table during a HANDLER .. READ statement. If the
table needed to be re-opened due to it's storage engine being
altered to one that doesn't support HANDLER, a reference (dangling
pointer) to a closed table could be left in place and accessed in
later attempts to fetch from the table using the handler. Also,
if the server failed to set a error message if the re-open
failed. These problems could lead to server crashes or hangs.
The solution is to remove any references to a closed table and
to set a error if reopening a table during a HANDLER .. READ
statement fails.
Bug#41112: crash in mysql_ha_close_table/get_lock_data with alter table
The problem is that the server wasn't handling robustly failures
to re-open a table during a HANDLER .. READ statement. If the
table needed to be re-opened due to it's storage engine being
altered to one that doesn't support HANDLER, a reference (dangling
pointer) to a closed table could be left in place and accessed in
later attempts to fetch from the table using the handler. Also,
if the server failed to set a error message if the re-open
failed. These problems could lead to server crashes or hangs.
The solution is to remove any references to a closed table and
to set a error if reopening a table during a HANDLER .. READ
statement fails.
There is no test case in this change set as the test depends on
a testing feature only available on 5.1 and later.
sql/sql_handler.cc:
Remove redundant reopen check.
Set errors even if reopening table.
Reset TABLE_LIST::table reference when the table is closed.
Bug#41112: crash in mysql_ha_close_table/get_lock_data with alter table
The problem is that the server wasn't handling robustly failures
to re-open a table during a HANDLER .. READ statement. If the
table needed to be re-opened due to it's storage engine being
altered to one that doesn't support HANDLER, a reference (dangling
pointer) to a closed table could be left in place and accessed in
later attempts to fetch from the table using the handler. Also,
if the server failed to set a error message if the re-open
failed. These problems could lead to server crashes or hangs.
The solution is to remove any references to a closed table and
to set a error if reopening a table during a HANDLER .. READ
statement fails.
There is no test case in this change set as the test depends on
a testing feature only available on 5.1 and later.
- Remove bothersome warning messages. This change focuses on the warnings
that are covered by the ignore file: support-files/compiler_warnings.supp.
- Strings are guaranteed to be max uint in length
- Remove bothersome warning messages. This change focuses on the warnings
that are covered by the ignore file: support-files/compiler_warnings.supp.
- Strings are guaranteed to be max uint in length
This bug is actually two bugs in one, one of which is CREATE TRIGGER under
LOCK TABLES and the other is CREATE TRIGGER under LOCK TABLES simultaneous
to a FLUSH TABLES WITH READ LOCK (global read lock). Both situations could
lead to a server crash or deadlock.
The first problem arises from the fact that when under LOCK TABLES, if the
table is in the set of locked tables, the table is already open and it doesn't
need to be reopened (not a placeholder). Also in this case, if the table is
not write locked, a exclusive lock can't be acquired because of a possible
deadlock with another thread also holding a (read) lock on the table. The
second issue arises from the fact that one should never wait for a global
read lock if it's holding any locked tables, because the global read lock
is waiting for these tables and this leads to a circular wait deadlock.
The solution for the first case is to check if the table is write locked
and upgraded the write lock to a exclusive lock and fail otherwise for non
write locked tables. Grabbin the exclusive lock in this case also means
to ensure that the table is opened only by the calling thread. The second
issue is partly fixed by not waiting for the global read lock if the thread
is holding any locked tables.
The second issue is only partly addressed in this patch because it turned
out to be much wider and also affects other DDL statements. Reported as
Bug#32395
mysql-test/r/trigger.result:
Add test case result for Bug#23713
mysql-test/r/trigger_notembedded.result:
Add test case result for Bug#23713
mysql-test/t/trigger.test:
Add test case for Bug#23713
mysql-test/t/trigger_notembedded.test:
Add test case for Bug#23713
sql/mysql_priv.h:
Locally export wait_while_table_is_used and name_lock_locked_table
and add flag to mysql_ha_rm_tables to signal that LOCK_open is locked.
sql/sql_base.cc:
Introduce name_lock_locked_table function and match
close_old_data_files function declaration and definition.
sql/sql_handler.cc:
Add flag to mysql_ha_rm_tables to signal that LOCK_open is locked.
sql/sql_rename.cc:
Fix mysql_ha_rm_tables caller.
sql/sql_table.cc:
Export wait_while_table_is_used and assert that LOCK_open is locked
and fix mysql_ha_rm_tables caller.
sql/sql_trigger.cc:
Upgrade write locked tables to a exclusive lock and fail if
the table is not write locked. Also, don't wait for the global
read lock if under LOCK TABLES.
This bug is actually two bugs in one, one of which is CREATE TRIGGER under
LOCK TABLES and the other is CREATE TRIGGER under LOCK TABLES simultaneous
to a FLUSH TABLES WITH READ LOCK (global read lock). Both situations could
lead to a server crash or deadlock.
The first problem arises from the fact that when under LOCK TABLES, if the
table is in the set of locked tables, the table is already open and it doesn't
need to be reopened (not a placeholder). Also in this case, if the table is
not write locked, a exclusive lock can't be acquired because of a possible
deadlock with another thread also holding a (read) lock on the table. The
second issue arises from the fact that one should never wait for a global
read lock if it's holding any locked tables, because the global read lock
is waiting for these tables and this leads to a circular wait deadlock.
The solution for the first case is to check if the table is write locked
and upgraded the write lock to a exclusive lock and fail otherwise for non
write locked tables. Grabbin the exclusive lock in this case also means
to ensure that the table is opened only by the calling thread. The second
issue is partly fixed by not waiting for the global read lock if the thread
is holding any locked tables.
The second issue is only partly addressed in this patch because it turned
out to be much wider and also affects other DDL statements. Reported as
Bug#32395
The problem is that DROP TABLE and other DDL statements failed to
automatically close handlers associated with tables that were marked
for reopen (FLUSH TABLES).
The current implementation fails to properly discard handlers of
dropped tables (that were marked for reopen) because it searches
on the open handler tables list and using the current alias of the
table being dropped. The problem is that it must not use the open
handler tables list to search because the table might have been
closed (marked for reopen) by a flush tables command and also it
must not use the current table alias at all since multiple different
aliases may be associated with a single table. This is specially
visible when a user has two open handlers (using alias) of a same
table and a flush tables command is issued before the table is
dropped (see test case). Scanning the handler table list is also
useless for dropping handlers associated with temporary tables,
because temporary tables are not kept in the THD::handler_tables
list.
The solution is to simple scan the handlers hash table searching
for, and deleting all handlers with matching table names if the
reopen flag is not passed to the flush function, indicating that
the handlers should be deleted. All matching handlers are deleted
even if the associated the table is not open.
mysql-test/include/handler.inc:
Add test case for Bug#31397
mysql-test/r/handler_innodb.result:
Add test case result for Bug#31397
mysql-test/r/handler_myisam.result:
Add test case result for Bug#31397
sql/mysql_priv.h:
Rename flush functions to better match the intent of the caller and
update functions prototypes and remove unused flags.
sql/sql_base.cc:
Rename flush functions to better match the intent of the caller.
sql/sql_class.cc:
Rename the flush functions to better match the intent of the caller.
The hash_free function is moved to the cleanup.
sql/sql_handler.cc:
When dropping tables for a final close, scan the handler's hash table since
the table might not be in the handlers open table list because the table was
marked for reopen or because it's a temporary table.
sql/sql_rename.cc:
Drop handlers associated with tables that are being renamed.
sql/sql_table.cc:
Now that temporary tables are properly removed even when opened
by a SQL HANDLER, enable the assert since this branch can't be taken
outside of SF/trigger/prelocked mode.
The problem is that DROP TABLE and other DDL statements failed to
automatically close handlers associated with tables that were marked
for reopen (FLUSH TABLES).
The current implementation fails to properly discard handlers of
dropped tables (that were marked for reopen) because it searches
on the open handler tables list and using the current alias of the
table being dropped. The problem is that it must not use the open
handler tables list to search because the table might have been
closed (marked for reopen) by a flush tables command and also it
must not use the current table alias at all since multiple different
aliases may be associated with a single table. This is specially
visible when a user has two open handlers (using alias) of a same
table and a flush tables command is issued before the table is
dropped (see test case). Scanning the handler table list is also
useless for dropping handlers associated with temporary tables,
because temporary tables are not kept in the THD::handler_tables
list.
The solution is to simple scan the handlers hash table searching
for, and deleting all handlers with matching table names if the
reopen flag is not passed to the flush function, indicating that
the handlers should be deleted. All matching handlers are deleted
even if the associated the table is not open.
If a stored function that contains a drop temporary table statement
is invoked by a create temporary table of the same name may cause
a server crash. The problem is that when dropping a table no check
is done to ensure that table is not being used by some outer query
(or outer statement), potentially leaving the outer query with a
reference to a stale (freed) table.
The solution is when dropping a temporary table, always check if
the table is being used by some outer statement as a temporary
table can be dropped inside stored procedures.
The check is performed by looking at the TABLE::query_id value for
temporary tables. To simplify this check and to solve a bug related
to handling of temporary tables in prelocked mode, this patch changes
the way in which this member is used to track the fact that table is
used/unused. Now we ensure that TABLE::query_id is zero for unused
temporary tables (which means that all temporary tables which were
used by a statement should be marked as free for reuse after it's
execution has been completed).
mysql-test/include/handler.inc:
Add test case for side effect of Bug#30882
mysql-test/r/handler_innodb.result:
Add test case result for side effect of Bug#30882
mysql-test/r/handler_myisam.result:
Add test case result for side effect of Bug#30882
mysql-test/r/sp-error.result:
Add test case result for Bug#30882
mysql-test/t/sp-error.test:
Add test case for Bug#30882
sql/event_db_repository.cc:
Update close_thread_tables call, no more default values.
sql/mysql_priv.h:
Remove implicit default parameters values of the close_thread_tables
function as no callers are using it.
sql/slave.cc:
Update close_thread_tables call, no more default values
sql/sp_head.cc:
Update close_thread_tables call, no more default values
sql/sql_base.cc:
Changed the approach to distinguishing currently unused temporary tables.
Now we ensure that such tables always have TABLE::query_id set to 0 and
use this fact to perform checks during opening and dropping of temporary
tables. This means that we have to call close_thread_tables() even for
statements which use only temporary tables. To make this call cheaper,
we re-factored close_thread_tables() to not take LOCK_open unless there
are open base tables.
sql/sql_handler.cc:
Properly close temporary tables associated with a handler.
sql/sql_insert.cc:
close_temporary_table is now merged into drop_temporary_table.
sql/sql_parse.cc:
Now the condition doesn't cover all cases because close_thread_tables()
must be called even for statements that use only temporary tables.
sql/sql_table.cc:
Use drop_temporary_table which perform checks to verify if
the table is not being used. Error path problem is due to
a handler tables issue and is going to be addressed in bug
31397.
sql/table.h:
Rename previously unused clear_query_id and document the usage of
query_id and open_by_handler.
If a stored function that contains a drop temporary table statement
is invoked by a create temporary table of the same name may cause
a server crash. The problem is that when dropping a table no check
is done to ensure that table is not being used by some outer query
(or outer statement), potentially leaving the outer query with a
reference to a stale (freed) table.
The solution is when dropping a temporary table, always check if
the table is being used by some outer statement as a temporary
table can be dropped inside stored procedures.
The check is performed by looking at the TABLE::query_id value for
temporary tables. To simplify this check and to solve a bug related
to handling of temporary tables in prelocked mode, this patch changes
the way in which this member is used to track the fact that table is
used/unused. Now we ensure that TABLE::query_id is zero for unused
temporary tables (which means that all temporary tables which were
used by a statement should be marked as free for reuse after it's
execution has been completed).
If mysql_lock_tables fails because the lock was aborted, we need to
reset thd->some_tables_delete, otherwise we might loop indefinitely
because handler's tables are not closed in a standard way, meaning
that close_thread_tables() (which resets some_tables_deleted) is not
used.
This patch fixes sporadical failures of handler_myisam/innodb tests
which were introduced by previous fix for this bug.
sql/sql_handler.cc:
Properly reset thd->some_tables_deleted if mysql_lock_tables
fails for some reason.
If mysql_lock_tables fails because the lock was aborted, we need to
reset thd->some_tables_delete, otherwise we might loop indefinitely
because handler's tables are not closed in a standard way, meaning
that close_thread_tables() (which resets some_tables_deleted) is not
used.
This patch fixes sporadical failures of handler_myisam/innodb tests
which were introduced by previous fix for this bug.
This deadlock occurs when a client issues a HANDLER ... OPEN statement
that tries to open a table that has a pending name-lock on it by another
client that also needs a name-lock on some other table which is already
open and associated to a HANDLER instance owned by the first client.
The deadlock happens because the open_table() function will back-off
and wait until the name-lock goes away, causing a circular wait if some
other name-lock is also pending for one of the open HANDLER tables.
Such situation, for example, can be easily repeated by issuing a RENAME
TABLE command in such a way that the existing table is already open
as a HANDLER table by another client and this client tries to open
a HANDLER to the new table name.
The solution is to allow handler tables with older versions (marked for
flush) to be closed before waiting for the name-lock completion. This is
safe because no other name-lock can be issued between the flush and the
check for pending name-locks.
The test case for this bug is going to be committed into 5.1 because it
requires a test feature only avaiable in 5.1 (wait_condition).
sql/sql_base.cc:
Improve comments in the open_table() function, stating the importance
of the handler tables flushing for the back-off process.
sql/sql_handler.cc:
Allows handler tables flushes when opening new tables in order to avoid
potential deadlocks. Add comments explaining the importance of the flush.
This deadlock occurs when a client issues a HANDLER ... OPEN statement
that tries to open a table that has a pending name-lock on it by another
client that also needs a name-lock on some other table which is already
open and associated to a HANDLER instance owned by the first client.
The deadlock happens because the open_table() function will back-off
and wait until the name-lock goes away, causing a circular wait if some
other name-lock is also pending for one of the open HANDLER tables.
Such situation, for example, can be easily repeated by issuing a RENAME
TABLE command in such a way that the existing table is already open
as a HANDLER table by another client and this client tries to open
a HANDLER to the new table name.
The solution is to allow handler tables with older versions (marked for
flush) to be closed before waiting for the name-lock completion. This is
safe because no other name-lock can be issued between the flush and the
check for pending name-locks.
The test case for this bug is going to be committed into 5.1 because it
requires a test feature only avaiable in 5.1 (wait_condition).
