result set when SQLEXCEPTION is active.
The problem was in a hackish THD::no_warnings_for_error attribute.
When it was set, an error was not written to Warning_info -- only
Diagnostics_area state was changed. That means, Diagnostics_area
might contain error state, which is not present in Warning_info.
The user-visible problem was that in some cases SHOW WARNINGS
returned empty result set (i.e. there were no warnings) while
the previous SQL statement failed. According to the MySQL
protocol errors must be presented in warning list.
The main idea of this patch is to remove THD::no_warnings_for_error.
There were few places where it was used:
- sql_admin.cc, handling of REPAIR TABLE USE_FRM.
- sql_show.cc, when calling fill_schema_table_from_frm().
- sql_show.cc, when calling fill_table().
The fix is to either use internal-error-handlers, or to use
temporary Warning_info storing warnings, which might be ignored.
This patch is needed to fix Bug 11763162 (55843).
result set when SQLEXCEPTION is active.
The problem was in a hackish THD::no_warnings_for_error attribute.
When it was set, an error was not written to Warning_info -- only
Diagnostics_area state was changed. That means, Diagnostics_area
might contain error state, which is not present in Warning_info.
The user-visible problem was that in some cases SHOW WARNINGS
returned empty result set (i.e. there were no warnings) while
the previous SQL statement failed. According to the MySQL
protocol errors must be presented in warning list.
The main idea of this patch is to remove THD::no_warnings_for_error.
There were few places where it was used:
- sql_admin.cc, handling of REPAIR TABLE USE_FRM.
- sql_show.cc, when calling fill_schema_table_from_frm().
- sql_show.cc, when calling fill_table().
The fix is to either use internal-error-handlers, or to use
temporary Warning_info storing warnings, which might be ignored.
This patch is needed to fix Bug 11763162 (55843).
DEFINITION OF ANY ROUTINE.
The problem was that having the SELECT privilege any column of the
mysql.proc table by mistake allowed the user to see the definition
of all routines (using SHOW CREATE PROCEDURE/FUNCTION and SHOW
PROCEDURE/FUNCTION CODE).
This patch fixes the problem by making sure that those commands
are only allowed if the user has the SELECT privilege on the
mysql.proc table itself.
Test case added to sp-security.test.
DEFINITION OF ANY ROUTINE.
The problem was that having the SELECT privilege any column of the
mysql.proc table by mistake allowed the user to see the definition
of all routines (using SHOW CREATE PROCEDURE/FUNCTION and SHOW
PROCEDURE/FUNCTION CODE).
This patch fixes the problem by making sure that those commands
are only allowed if the user has the SELECT privilege on the
mysql.proc table itself.
Test case added to sp-security.test.
and collateral changes.
* introduce my_hrtime_t, my_timediff_t, and conversion macros
* inroduce TIME_RESULT, but it can only be returned from Item::cmp_type(),
never from Item::result_type()
* pack_time/unpack_time function for "packed" representation of
MYSQL_TIME in a longlong that can be compared
* ADDTIME()/SUBTIME()/+- INTERVAL now work with TIME values
* numbers aren't quoted in EXPLAIN EXTENDED
* new column I_S.COLUMNS.DATETIME_PRECISION
* date/time values are compares to anything as date/time, not as strings or numbers.
* old timestamp(X) is no longer supported
* MYSQL_TIME to string conversion functions take precision as an argument
* unified the warnings from Field_timestamp/datetime/time/date/newdate store methods
* Field_timestamp_hires, Field_datetime_hires, Field_time_hires
* Field_temporal
* Lazy_string class to pass a value (string, number, time) polymorphically down the stack
* make_truncated_value_warning and Field::set_datetime_warning use Lazy_string as an argument, removed char*/int/double variants
* removed Field::can_be_compared_as_longlong(). Use Field::cmp_type() == INT_RESULT instead
* introduced Item::cmp_result() instead of Item::is_datetime() and Item::result_as_longlong()
* in many cases date/time types are treated like other types, not as special cases
* greatly simplified Arg_comparator (regarding date/time/year code)
* SEC_TO_TIME is real function, not integer.
* microsecond precision in NOW, CURTIME, etc
* Item_temporal. All items derived from it only provide get_date, but no val* methods
* replication of NOW(6)
* Protocol::store(time) now takes the precision as an argument
* @@TIMESTAMP is a double
client/mysqlbinlog.cc:
remove unneded casts
include/my_sys.h:
introduce my_hrtime_t, my_timediff_t, and conversion macros
include/my_time.h:
pack_time/unpack_time, etc.
convenience functions to work with MYSQL_TIME::second_part
libmysql/libmysql.c:
str_to_time() is gone. str_to_datetime() does it now.
my_TIME_to_str() takes the precision as an argument
mysql-test/include/ps_conv.inc:
time is not equal to datetime anymore
mysql-test/r/distinct.result:
a test for an old MySQL bug
mysql-test/r/explain.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/func_default.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/func_sapdb.result:
when decimals=NOT_FIXED_DEC it means "not fixed" indeed
mysql-test/r/func_test.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/func_time.result:
ADDTIME()/SUBTIME()/+- INTERVAL now work with TIME values
mysql-test/r/having.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/information_schema.result:
new column I_S.COLUMNS.DATETIME_PRECISION
mysql-test/r/join_outer.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/metadata.result:
TIMESTAMP no longer has zerofill flag
mysql-test/r/range.result:
invalid datetime is not compared with as a string
mysql-test/r/select.result:
NO_ZERO_IN_DATE, etc only affect storage - according to the manual
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/subselect.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/sysdate_is_now.result:
when decimals=NOT_FIXED_DEC it means "not fixed" indeed
mysql-test/r/type_blob.result:
TIMESTAMP(N) is not deprecated
mysql-test/r/type_timestamp.result:
old TIMESTAMP(X) semantics is not supported anymore
mysql-test/r/union.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/varbinary.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/t/distinct.test:
test for an old MySQL bug
mysql-test/t/func_time.test:
+- INTERVAL now works with TIME values
mysql-test/t/select.test:
typo
mysql-test/t/subselect.test:
only one error per statement, please
mysql-test/t/system_mysql_db_fix40123.test:
old timestamp(X) is no longer supported
mysql-test/t/system_mysql_db_fix50030.test:
old timestamp(X) is no longer supported
mysql-test/t/system_mysql_db_fix50117.test:
old timestamp(X) is no longer supported
mysql-test/t/type_blob.test:
old timestamp(X) is no longer supported
mysql-test/t/type_timestamp.test:
old timestamp(X) is no longer supported
mysys/my_getsystime.c:
functions to get the time with microsecond precision
mysys/my_init.c:
move the my_getsystime.c initialization code to my_getsystime.c
mysys/my_static.c:
no need to make these variables extern
mysys/my_static.h:
no need to make these variables extern
scripts/mysql_system_tables.sql:
old timestamp(X) is no longer supported
scripts/mysql_system_tables_fix.sql:
old timestamp(X) is no longer supported
scripts/mysqlhotcopy.sh:
old timestamp(X) is no longer supported
sql-common/my_time.c:
* call str_to_time from str_to_datetime, as appropriate
* date/time to string conversions take precision as an argument
* number_to_time()
* TIME_to_double()
* pack_time() and unpack_time()
sql/event_data_objects.cc:
cast is not needed
my_datetime_to_str() takes precision as an argument
sql/event_db_repository.cc:
avoid dangerous downcast (because the pointer is
not always Field_timestamp, see events_1.test)
sql/event_queue.cc:
avoid silly double-work for cond_wait
(having an endpoint of wait, subtract the current time to get the timeout,
and use set_timespec() macro to fill in struct timespec, by adding the current
time to the timeout)
sql/field.cc:
* remove virtual Field::get_time(), everyone should use only Field::get_date()
* remove lots of #ifdef WORDS_BIGENDIAN
* unified the warnings from Field_timestamp/datetime/time/date/newdate store methods
* Field_timestamp_hires, Field_datetime_hires, Field_time_hires
* Field_temporal
* make_truncated_value_warning and Field::set_datetime_warning use Lazy_string as an argument, removed char*/int/double variants
sql/field.h:
* remove virtual Field::get_time(), everyone should use only Field::get_date()
* remove lots of #ifdef WORDS_BIGENDIAN
* unified the warnings from Field_timestamp/datetime/time/date/newdate store methods
* Field_timestamp_hires, Field_datetime_hires, Field_time_hires
* Field_temporal
* make_truncated_value_warning and Field::set_datetime_warning use Lazy_string as an argument, removed char*/int/double variants
* removed Field::can_be_compared_as_longlong(). Use Field::cmp_type() == INT_RESULT instead
sql/filesort.cc:
TIME_RESULT, cmp_time()
sql/item.cc:
* numbers aren't quoted in EXPLAIN EXTENDED
* Item::cmp_result() instead of Item::is_datetime() and Item::result_as_longlong()
* virtual Item::get_time() is gone
* Item_param::field_type() is set correctly
* Item_datetime, for a datetime constant
* time to anything is compared as a time
* Item_cache::print() prints the value is available
* bug fixed in Item_cache_int::val_str()
sql/item.h:
* Item::print_value(), to be used from Item_xxx::print() when needed
* Item::cmp_result() instead of Item::is_datetime() and Item::result_as_longlong()
* virtual Item::get_time() is gone
* Item_datetime, for a datetime constant
* better default for cast_to_int_type()
* Item_cache objects now *always* have the field_type() set
sql/item_cmpfunc.cc:
* get_year_value, get_time_value are gone. get_datetime_value does it all
* get_value_a_func, get_value_b_func are gone
* can_compare_as_dates() is gone too, TIME_RESULT is used instead
* cmp_type() instead or result_type() when doing a comparison
* compare_datetime and compate_e_datetime in the comparator_matrix, is_nulls_eq is gone
* Item::cmp_result() instead of Item::is_datetime() and Item::result_as_longlong()
sql/item_cmpfunc.h:
greatly simplified Arg_comparator
sql/item_create.cc:
* fix a bug in error messages in CAST
sql/item_func.cc:
Item::cmp_result() instead of Item::is_datetime() and Item::result_as_longlong()
mention all possibitiles in switch over Item_result values, or use default:
sql/item_row.h:
overwrite the default cmp_type() for Item_row,
as no MYSQL_TYPE_xxx value corresponds to ROW_RESULT
sql/item_timefunc.cc:
rewrite make_datetime to support precision argument
SEC_TO_TIME is real function, not integer.
many functions that returned temporal values had duplicate code in val_* methods,
some of them did not have get_date() which resulted in unnecessary date->str->date conversions.
Now they all are derived from Item_temporal_func and *only* provide get_date, not val* methods.
many fixes to set decimals (datetime precision) correctly.
sql/item_timefunc.h:
SEC_TO_TIME is real function, not integer.
many functions that returned temporal values had duplicate code in val_* methods,
some of them did not have get_date() which resulted in unnecessary date->str->date conversions.
Now they all are derived from Item_temporal_func and *only* provide get_date, not val* methods.
many fixes to set decimals (datetime precision) correctly.
sql/log_event.cc:
replication of NOW(6)
sql/log_event.h:
replication of NOW(6)
sql/mysql_priv.h:
Lazy_string class to pass a value (string, number, time) polymorphically down the stack.
make_truncated_value_warning() that uses it.
sql/mysqld.cc:
datetime in Arg_comparator::comparator_matrix
sql/opt_range.cc:
cleanup: don't disable warnings before calling save_in_field_no_warnings()
sql/protocol.cc:
Protocol::store(time) now takes the precision as an argument
sql/protocol.h:
Protocol::store(time) now takes the precision as an argument
sql/rpl_rli.cc:
small cleanup
sql/set_var.cc:
SET TIMESTAMP=double
sql/set_var.h:
@@TIMESTAMP is a double
sql/share/errmsg.txt:
precision and scale are unsigned
sql/slave.cc:
replication of NOW(6)
sql/sp_head.cc:
cleanup
sql/sql_class.cc:
support for NOW(6)
sql/sql_class.h:
support for NOW(6)
sql/sql_insert.cc:
support for NOW(6)
sql/sql_select.cc:
use item->cmp_type().
move a comment where it belongs
sql/sql_show.cc:
new column I_S.COLUMNS.DATETIME_PRECISION
sql/sql_yacc.yy:
TIME(X), DATETIME(X), cast, NOW(X), CURTIME(X), etc
sql/time.cc:
fix date_add_interval() to support MYSQL_TIMESTAMP_TIME argument
storage/myisam/ha_myisam.cc:
TIMESTAMP no longer carries ZEROFIELD flag, still we keep MYI file compatible.
strings/my_vsnprintf.c:
warnings
tests/mysql_client_test.c:
old timestamp(X) does not work anymore
datetime is no longer equal to time
- Fixed some issues with partitions and connection_string, which also fixed lp:716890 "Pre- and post-recovery crash in Aria"
- Fixed wrong assert in Aria
Now need to merge with latest xtradb before pushing
sql/ha_partition.cc:
Ensure that m_ordered_rec_buffer is not freed before close.
sql/mysqld.cc:
Changed to use opt_stack_trace instead of opt_pstack.
Removed references to pstack
sql/partition_element.h:
Ensure that connect_string is initialized
storage/maria/ma_key_recover.c:
Fixed wrong assert
Removes SHOW NEW MASTER statement and all related code.
Also removes the unused function update_slave_list from repl_failsafe.cc.
mysql-test/r/signal_code.result:
Updated result file.
The output of SHOW PROCEDURE CODE has changed, because the numerical values
of some SQLCOM_ commands have changes. This is not a problem, because
SHOW PROCEDURE CODE only exists in debug builds and the numerical values of
SQLCOM_ constants are not exposed elsewhere.
mysql-test/r/sp-code.result:
Updated result file.
The output of SHOW PROCEDURE CODE has changed, because the numerical values
of some SQLCOM_ commands have changes. This is not a problem, because
SHOW PROCEDURE CODE only exists in debug builds and the numerical values of
SQLCOM_ constants are not exposed elsewhere.
sql/mysqld.cc:
Remove SQLCOM_SHOW_NEW_MASTER.
sql/repl_failsafe.cc:
Remove show_new_master, which was only used by the removed SHOW NEW MASTER statement.
Remove translate_master, which was only used by show_new_master.
Remove find_slave_event, which was only used by translate_master.
Remove find_target_pos, which was only used by translate_master.
Remove cmp_master_pos, which was only used by translate_master.
Remove update_slave_list, which was not used at all.
sql/repl_failsafe.h:
Remove declarations of functions removed by this patch:
update_slave_list, show_new_master, translate_master, update_slave_list
Remove declarations of functions that did not exist before this patch:
handle_failsafe_rpl, load_master_data
Remove declaration of function that is static in slave.cc:
connect_to_master
sql/sp_head.cc:
Removed SQLCOM_SHOW_NEW_MASTER
sql/sql_lex.h:
Removed SQLCOM_SHOW_NEW_MASTER
sql/sql_parse.cc:
Removed SQLCOM_SHOW_NEW_MASTER
sql/sql_repl.cc:
Removed cmp_master_pos(char*,ulonglong,char*,ulonglong), which was
only used by cmp_master_pos*Slave_log_event* sev, LEX_MASTER_INFO* mi) in repl_failsafe.cc,
which has been removed.
sql/sql_repl.h:
removed cmp_master_pos
sql/sql_yacc.yy:
removed syntax SHOW NEW MASTER.
Fixed the references to security_ctx->priv_user
to be real char * pointers instead of a C array name reference.
This is somehow important for some 3d party
dtrace replacements
Fixed the references to security_ctx->priv_user
to be real char * pointers instead of a C array name reference.
This is somehow important for some 3d party
dtrace replacements
Problem: Extended characters outside of ASCII range where not displayed
properly in SHOW PROCESSLIST, because thd_info->query was always sent as
system_character_set (utf8). This was wrong, because query buffer
is never converted to utf8 - it is always have client character set.
Fix: sending query buffer using query character set
@ sql/sql_class.cc
@ sql/sql_class.h
Introducing a new class CSET_STRING, a LEX_STRING with character set.
Adding set_query(&CSET_STRING)
Adding reset_query(), to use instead of set_query(0, NULL).
@ sql/event_data_objects.cc
Using reset_query()
@ sql/log_event.cc
Using reset_query()
Adding charset argument to set_query_and_id().
@ sql/slave.cc
Using reset_query().
@ sql/sp_head.cc
Changing backing up and restore code to use CSET_STRING.
@ sql/sql_audit.h
Using CSET_STRING.
In the "else" branch it's OK not to use
global_system_variables.character_set_client.
&my_charset_latin1, which is set in constructor, is fine
(verified with Sergey Vojtovich).
@ sql/sql_insert.cc
Using set_query() with proper character set: table_name is utf8.
@ sql/sql_parse.cc
Adding character set argument to set_query_and_id().
(This is the main point where thd->charset() is stored
into thd->query_string.cs, for use in "SHOW PROCESSLIST".)
Using reset_query().
@ sql/sql_prepare.cc
Storing client character set into thd->query_string.cs.
@ sql/sql_show.cc
Using CSET_STRING to fetch and send charset-aware query information
from threads.
@ storage/myisam/ha_myisam.cc
Using set_query() with proper character set: table_name is utf8.
@ mysql-test/r/show_check.result
@ mysql-test/t/show_check.test
Adding tests
Problem: Extended characters outside of ASCII range where not displayed
properly in SHOW PROCESSLIST, because thd_info->query was always sent as
system_character_set (utf8). This was wrong, because query buffer
is never converted to utf8 - it is always have client character set.
Fix: sending query buffer using query character set
@ sql/sql_class.cc
@ sql/sql_class.h
Introducing a new class CSET_STRING, a LEX_STRING with character set.
Adding set_query(&CSET_STRING)
Adding reset_query(), to use instead of set_query(0, NULL).
@ sql/event_data_objects.cc
Using reset_query()
@ sql/log_event.cc
Using reset_query()
Adding charset argument to set_query_and_id().
@ sql/slave.cc
Using reset_query().
@ sql/sp_head.cc
Changing backing up and restore code to use CSET_STRING.
@ sql/sql_audit.h
Using CSET_STRING.
In the "else" branch it's OK not to use
global_system_variables.character_set_client.
&my_charset_latin1, which is set in constructor, is fine
(verified with Sergey Vojtovich).
@ sql/sql_insert.cc
Using set_query() with proper character set: table_name is utf8.
@ sql/sql_parse.cc
Adding character set argument to set_query_and_id().
(This is the main point where thd->charset() is stored
into thd->query_string.cs, for use in "SHOW PROCESSLIST".)
Using reset_query().
@ sql/sql_prepare.cc
Storing client character set into thd->query_string.cs.
@ sql/sql_show.cc
Using CSET_STRING to fetch and send charset-aware query information
from threads.
@ storage/myisam/ha_myisam.cc
Using set_query() with proper character set: table_name is utf8.
@ mysql-test/r/show_check.result
@ mysql-test/t/show_check.test
Adding tests
network when a query was slow.
When a query is slow, sent a special flag to the client
indicating this fact.
Add a test case.
Implement review comments.
include/mysql_com.h:
Clear SERVER_QUERY_WAS_SLOW at end of each statement.
Since this patch removes the technique when
thd->server_status is modified briefly only to
execute my_eof(), reset more server status
bit that may remain in the status from
execution of the previous statement.
sql/protocol.cc:
Always use thd->server_status to
in net_* functions to send the latest
status to the client.
sql/sp_head.cc:
Calculate if a query was slow before
sending EOF packet.
sql/sql_cursor.cc:
Remove juggling with thd->server_status.
The extra status bits are reset at
start of the next statement.
sql/sql_db.cc:
Remove juggling with thd->server_status.
The extra status bits are reset at
start of the next statement.
sql/sql_error.cc:
Remove m_server_status member,
it's not really part of the Diagnostics_area.
sql/sql_error.h:
Remove server_status member, it's
not part of the Diagnostics_area.
The associated hack is removed as well.
sql/sql_parse.cc:
Do not calculate if a query was
slow twice. Use a status flag in thd->server_status.
tests/mysql_client_test.c:
Add a test case for Bug#57058.
Check that the status is present
at the client, when sent.
network when a query was slow.
When a query is slow, sent a special flag to the client
indicating this fact.
Add a test case.
Implement review comments.
Text conflict in mysql-test/suite/perfschema/r/dml_setup_instruments.result
Text conflict in mysql-test/suite/perfschema/r/global_read_lock.result
Text conflict in mysql-test/suite/perfschema/r/server_init.result
Text conflict in mysql-test/suite/perfschema/t/global_read_lock.test
Text conflict in mysql-test/suite/perfschema/t/server_init.test
Text conflict in mysql-test/suite/perfschema/r/dml_setup_instruments.result
Text conflict in mysql-test/suite/perfschema/r/global_read_lock.result
Text conflict in mysql-test/suite/perfschema/r/server_init.result
Text conflict in mysql-test/suite/perfschema/t/global_read_lock.test
Text conflict in mysql-test/suite/perfschema/t/server_init.test
bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ
LOCK" and bug #54673 "It takes too long to get readlock for
'FLUSH TABLES WITH READ LOCK'".
The first bug manifested itself as a deadlock which occurred
when a connection, which had some table open through HANDLER
statement, tried to update some data through DML statement
while another connection tried to execute FLUSH TABLES WITH
READ LOCK concurrently.
What happened was that FTWRL in the second connection managed
to perform first step of GRL acquisition and thus blocked all
upcoming DML. After that it started to wait for table open
through HANDLER statement to be flushed. When the first connection
tried to execute DML it has started to wait for GRL/the second
connection creating deadlock.
The second bug manifested itself as starvation of FLUSH TABLES
WITH READ LOCK statements in cases when there was a constant
stream of concurrent DML statements (in two or more
connections).
This has happened because requests for protection against GRL
which were acquired by DML statements were ignoring presence of
pending GRL and thus the latter was starved.
This patch solves both these problems by re-implementing GRL
using metadata locks.
Similar to the old implementation acquisition of GRL in new
implementation is two-step. During the first step we block
all concurrent DML and DDL statements by acquiring global S
metadata lock (each DML and DDL statement acquires global IX
lock for its duration). During the second step we block commits
by acquiring global S lock in COMMIT namespace (commit code
acquires global IX lock in this namespace).
Note that unlike in old implementation acquisition of
protection against GRL in DML and DDL is semi-automatic.
We assume that any statement which should be blocked by GRL
will either open and acquires write-lock on tables or acquires
metadata locks on objects it is going to modify. For any such
statement global IX metadata lock is automatically acquired
for its duration.
The first problem is solved because waits for GRL become
visible to deadlock detector in metadata locking subsystem
and thus deadlocks like one in the first bug become impossible.
The second problem is solved because global S locks which
are used for GRL implementation are given preference over
IX locks which are acquired by concurrent DML (and we can
switch to fair scheduling in future if needed).
Important change:
FTWRL/GRL no longer blocks DML and DDL on temporary tables.
Before this patch behavior was not consistent in this respect:
in some cases DML/DDL statements on temporary tables were
blocked while in others they were not. Since the main use cases
for FTWRL are various forms of backups and temporary tables are
not preserved during backups we have opted for consistently
allowing DML/DDL on temporary tables during FTWRL/GRL.
Important change:
This patch changes thread state names which are used when
DML/DDL of FTWRL is waiting for global read lock. It is now
either "Waiting for global read lock" or "Waiting for commit
lock" depending on the stage on which FTWRL is.
Incompatible change:
To solve deadlock in events code which was exposed by this
patch we have to replace LOCK_event_metadata mutex with
metadata locks on events. As result we have to prohibit
DDL on events under LOCK TABLES.
This patch also adds extensive test coverage for interaction
of DML/DDL and FTWRL.
Performance of new and old global read lock implementations
in sysbench tests were compared. There were no significant
difference between new and old implementations.
mysql-test/include/check_ftwrl_compatible.inc:
Added helper script which allows to check that a statement is
compatible with FLUSH TABLES WITH READ LOCK.
mysql-test/include/check_ftwrl_incompatible.inc:
Added helper script which allows to check that a statement is
incompatible with FLUSH TABLES WITH READ LOCK.
mysql-test/include/handler.inc:
Adjusted test case to the fact that now DROP TABLE closes
open HANDLERs for the table to be dropped before checking
if there active FTWRL in this connection.
mysql-test/include/wait_show_condition.inc:
Fixed small error in the timeout message. The correct name
of variable used as parameter for this script is "$condition"
and not "$wait_condition".
mysql-test/r/delayed.result:
Added test coverage for scenario which triggered assert in
metadata locking subsystem.
mysql-test/r/events_2.result:
Updated test results after prohibiting event DDL operations
under LOCK TABLES.
mysql-test/r/flush.result:
Added test coverage for bug #57006 "Deadlock between HANDLER
and FLUSH TABLES WITH READ LOCK".
mysql-test/r/flush_read_lock.result:
Added test coverage for various aspects of FLUSH TABLES WITH
READ LOCK functionality.
mysql-test/r/flush_read_lock_kill.result:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Use new
debug_sync point. Do not disable concurrent inserts as now
InnoDB we always use InnoDB table.
mysql-test/r/handler_innodb.result:
Adjusted test case to the fact that now DROP TABLE closes
open HANDLERs for the table to be dropped before checking
if there active FTWRL in this connection.
mysql-test/r/handler_myisam.result:
Adjusted test case to the fact that now DROP TABLE closes
open HANDLERs for the table to be dropped before checking
if there active FTWRL in this connection.
mysql-test/r/mdl_sync.result:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Replaced
usage of GRL-specific debug_sync's with appropriate sync
points in MDL subsystem.
mysql-test/suite/perfschema/r/dml_setup_instruments.result:
Updated test results after removing global
COND_global_read_lock condition variable.
mysql-test/suite/perfschema/r/func_file_io.result:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/r/func_mutex.result:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/r/global_read_lock.result:
Adjusted test case to take into account that new GRL
implementation is based on MDL.
mysql-test/suite/perfschema/r/server_init.result:
Adjusted test case after replacing custom global read
lock implementation with one based on MDL and replacing
LOCK_event_metadata mutex with metadata lock.
mysql-test/suite/perfschema/t/func_file_io.test:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/t/func_mutex.test:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/t/global_read_lock.test:
Adjusted test case to take into account that new GRL
implementation is based on MDL.
mysql-test/suite/perfschema/t/server_init.test:
Adjusted test case after replacing custom global read
lock implementation with one based on MDL and replacing
LOCK_event_metadata mutex with metadata lock.
mysql-test/suite/rpl/r/rpl_tmp_table_and_DDL.result:
Updated test results after prohibiting event DDL under
LOCK TABLES.
mysql-test/t/delayed.test:
Added test coverage for scenario which triggered assert in
metadata locking subsystem.
mysql-test/t/events_2.test:
Updated test case after prohibiting event DDL operations
under LOCK TABLES.
mysql-test/t/flush.test:
Added test coverage for bug #57006 "Deadlock between HANDLER
and FLUSH TABLES WITH READ LOCK".
mysql-test/t/flush_block_commit.test:
Adjusted test case after changing thread state name which
is used when COMMIT waits for FLUSH TABLES WITH READ LOCK
from "Waiting for release of readlock" to "Waiting for commit
lock".
mysql-test/t/flush_block_commit_notembedded.test:
Adjusted test case after changing thread state name which is
used when DML waits for FLUSH TABLES WITH READ LOCK. Now we
use "Waiting for global read lock" in this case.
mysql-test/t/flush_read_lock.test:
Added test coverage for various aspects of FLUSH TABLES WITH
READ LOCK functionality.
mysql-test/t/flush_read_lock_kill-master.opt:
We no longer need to use make_global_read_lock_block_commit_loop
debug tag in this test. Instead we rely on an appropriate
debug_sync point in MDL code.
mysql-test/t/flush_read_lock_kill.test:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Use new
debug_sync point. Do not disable concurrent inserts as now
InnoDB we always use InnoDB table.
mysql-test/t/lock_multi.test:
Adjusted test case after changing thread state names which
are used when DML or DDL waits for FLUSH TABLES WITH READ
LOCK to "Waiting for global read lock".
mysql-test/t/mdl_sync.test:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Replaced
usage of GRL-specific debug_sync's with appropriate sync
points in MDL subsystem. Updated thread state names which
are used when DDL waits for FTWRL.
mysql-test/t/trigger_notembedded.test:
Adjusted test case after changing thread state names which
are used when DML or DDL waits for FLUSH TABLES WITH READ
LOCK to "Waiting for global read lock".
sql/event_data_objects.cc:
Removed Event_queue_element::status/last_executed_changed
members and Event_queue_element::update_timing_fields()
method. We no longer use this class for updating mysql.events
once event is chosen for execution. Accesses to instances of
this class in scheduler thread require protection by
Event_queue::LOCK_event_queue mutex and we try to avoid
updating table while holding this lock.
sql/event_data_objects.h:
Removed Event_queue_element::status/last_executed_changed
members and Event_queue_element::update_timing_fields()
method. We no longer use this class for updating mysql.events
once event is chosen for execution. Accesses to instances of
this class in scheduler thread require protection by
Event_queue::LOCK_event_queue mutex and we try to avoid
updating table while holding this lock.
sql/event_db_repository.cc:
- Changed Event_db_repository methods to not release all
metadata locks once they are done updating mysql.events
table. This allows to keep metadata lock protecting
against GRL and lock protecting particular event around
until corresponding DDL statement is written to the binary
log.
- Removed logic for conditional update of "status" and
"last_executed" fields from update_timing_fields_for_event()
method. In the only case when this method is called now
"last_executed" is always modified and tracking change
of "status" is too much hassle.
sql/event_db_repository.h:
Removed logic for conditional update of "status" and
"last_executed" fields from Event_db_repository::
update_timing_fields_for_event() method.
In the only case when this method is called now "last_executed"
is always modified and tracking change of "status" field is
too much hassle.
sql/event_queue.cc:
Changed event scheduler code not to update mysql.events
table while holding Event_queue::LOCK_event_queue mutex.
Doing so led to a deadlock with a new GRL implementation.
This deadlock didn't occur with old implementation due to
fact that code acquiring protection against GRL ignored
pending GRL requests (which lead to GRL starvation).
One of goals of new implementation is to disallow GRL
starvation and so we have to solve problem with this
deadlock in a different way.
sql/events.cc:
Changed methods of Events class to acquire protection
against GRL while perfoming DDL statement and keep it
until statement is written to the binary log.
Unfortunately this step together with new GRL implementation
exposed deadlock involving Events::LOCK_event_metadata
and GRL. To solve it Events::LOCK_event_metadata mutex was
replaced with a metadata lock on event. As a side-effect
events DDL has to be prohibited under LOCK TABLES even in
cases when mysql.events table was explicitly locked for
write.
sql/events.h:
Replaced Events::LOCK_event_metadata mutex with a metadata
lock on event.
sql/ha_ndbcluster.cc:
Updated code after replacing custom global read lock
implementation with one based on MDL. Since MDL subsystem
should now be able to detect deadlocks involving metadata
locks and GRL there is no need for special handling of
active GRL.
sql/handler.cc:
Replaced custom implementation of global read lock with
one based on metadata locks. Consequently when doing
commit instead of calling method of Global_read_lock
class to acquire protection against GRL we simply acquire
IX in COMMIT namespace.
sql/lock.cc:
Replaced custom implementation of global read lock with
one based on metadata locks. This step allows to expose
wait for GRL to deadlock detector of MDL subsystem and
thus succesfully resolve deadlocks similar to one behind
bug #57006 "Deadlock between HANDLER and FLUSH TABLES
WITH READ LOCK". It also solves problem with GRL starvation
described in bug #54673 "It takes too long to get readlock
for 'FLUSH TABLES WITH READ LOCK'" since metadata locks used
by GRL give preference to FTWRL statement instead of DML
statements (if needed in future this can be changed to
fair scheduling).
Similar to old implementation of acquisition of GRL is
two-step. During the first step we block all concurrent
DML and DDL statements by acquiring global S metadata lock
(each DML and DDL statement acquires global IX lock for
its duration). During the second step we block commits by
acquiring global S lock in COMMIT namespace (commit code
acquires global IX lock in this namespace).
Note that unlike in old implementation acquisition of
protection against GRL in DML and DDL is semi-automatic.
We assume that any statement which should be blocked by GRL
will either open and acquires write-lock on tables or acquires
metadata locks on objects it is going to modify. For any such
statement global IX metadata lock is automatically acquired
for its duration.
To support this change:
- Global_read_lock::lock/unlock_global_read_lock and
make_global_read_lock_block_commit methods were changed
accordingly.
- Global_read_lock::wait_if_global_read_lock() and
start_waiting_global_read_lock() methods were dropped.
It is now responsibility of code acquiring metadata locks
opening tables to acquire protection against GRL by
explicitly taking global IX lock with statement duration.
- Global variables, mutex and condition variable used by
old implementation was removed.
- lock_routine_name() was changed to use statement duration for
its global IX lock. It was also renamed to lock_object_name()
as it now also used to take metadata locks on events.
- Global_read_lock::set_explicit_lock_duration() was added which
allows not to release locks used for GRL when leaving prelocked
mode.
sql/lock.h:
- Renamed lock_routine_name() to lock_object_name() and changed
its signature to allow its usage for events.
- Removed broadcast_refresh() function. It is no longer needed
with new GRL implementation.
sql/log_event.cc:
Release metadata locks with statement duration at the end
of processing legacy event for LOAD DATA. This ensures that
replication thread processing such event properly releases
its protection against global read lock.
sql/mdl.cc:
Changed MDL subsystem to support new MDL-based implementation
of global read lock.
Added COMMIT and EVENTS namespaces for metadata locks. Changed
thread state name for GLOBAL namespace to "Waiting for global
read lock".
Optimized MDL_map::find_or_insert() method to avoid taking
m_mutex mutex when looking up MDL_lock objects for GLOBAL
or COMMIT namespaces. We keep pre-created MDL_lock objects
for these namespaces around and simply return pointers to
these global objects when needed.
Changed MDL_lock/MDL_scoped_lock to properly handle
notification of insert delayed handler threads when FTWRL
takes global S lock.
Introduced concept of lock duration. In addition to locks with
transaction duration which work in the way which is similar to
how locks worked before (i.e. they are released at the end of
transaction), locks with statement and explicit duration were
introduced.
Locks with statement duration are automatically released at the
end of statement. Locks with explicit duration require explicit
release and obsolete concept of transactional sentinel.
* Changed MDL_request and MDL_ticket classes to support notion
of duration.
* Changed MDL_context to keep locks with different duration in
different lists. Changed code handling ticket list to take
this into account.
* Changed methods responsible for releasing locks to take into
account duration of tickets. Particularly public
MDL_context::release_lock() method now only can release
tickets with explicit duration (there is still internal
method which allows to specify duration). To release locks
with statement or transaction duration one have to use
release_statement/transactional_locks() methods.
* Concept of savepoint for MDL subsystem now has to take into
account locks with statement duration. Consequently
MDL_savepoint class was introduced and methods working with
savepoints were updated accordingly.
* Added methods which allow to set duration for one or all
locks in the context.
sql/mdl.h:
Changed MDL subsystem to support new MDL-based implementation
of global read lock.
Added COMMIT and EVENTS namespaces for metadata locks.
Introduced concept of lock duration. In addition to locks with
transaction duration which work in the way which is similar to
how locks worked before (i.e. they are released at the end of
transaction), locks with statement and explicit duration were
introduced.
Locks with statement duration are automatically released at the
end of statement. Locks with explicit duration require explicit
release and obsolete concept of transactional sentinel.
* Changed MDL_request and MDL_ticket classes to support notion
of duration.
* Changed MDL_context to keep locks with different duration in
different lists. Changed code handling ticket list to take
this into account.
* Changed methods responsible for releasing locks to take into
account duration of tickets. Particularly public
MDL_context::release_lock() method now only can release
tickets with explicit duration (there is still internal
method which allows to specify duration). To release locks
with statement or transaction duration one have to use
release_statement/transactional_locks() methods.
* Concept of savepoint for MDL subsystem now has to take into
account locks with statement duration. Consequently
MDL_savepoint class was introduced and methods working with
savepoints were updated accordingly.
* Added methods which allow to set duration for one or all
locks in the context.
sql/mysqld.cc:
Removed global mutex and condition variables which were used
by old implementation of GRL.
Also we no longer need to initialize Events::LOCK_event_metadata
mutex as it was replaced with metadata locks on events.
sql/mysqld.h:
Removed global variable, mutex and condition variables which
were used by old implementation of GRL.
sql/rpl_rli.cc:
When slave thread closes tables which were open for handling
of RBR events ensure that it releases global IX lock which
was acquired as protection against GRL.
sql/sp.cc:
Adjusted code to the new signature of lock_object/routine_name(),
to the fact that one now needs specify duration of lock when
initializing MDL_request and to the fact that savepoints for MDL
subsystem are now represented by MDL_savepoint class.
sql/sp_head.cc:
Ensure that statements in stored procedures release statement
metadata locks and thus release their protectiong against GRL
in proper moment in time.
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/sql_admin.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/sql_base.cc:
- Implemented support for new approach to acquiring protection
against global read lock. We no longer acquire such protection
explicitly on the basis of statement flags. Instead we always
rely on code which is responsible for acquiring metadata locks
on object to be changed acquiring this protection. This is
achieved by acquiring global IX metadata lock with statement
duration. Code doing this also responsible for checking that
current connection has no active GRL by calling an
Global_read_lock::can_acquire_protection() method.
Changed code in open_table() and lock_table_names()
accordingly.
Note that as result of this change DDL and DML on temporary
tables is always compatible with GRL (before it was
incompatible in some cases and compatible in other cases).
- To speed-up code acquiring protection against GRL introduced
m_has_protection_against_grl member in Open_table_context
class. It indicates that protection was already acquired
sometime during open_tables() execution and new attempts
can be skipped.
- Thanks to new GRL implementation calls to broadcast_refresh()
became unnecessary and were removed.
- Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request and to the fact that
savepoints for MDL subsystem are now represented by
MDL_savepoint class.
sql/sql_base.h:
Adjusted code to the fact that savepoints for MDL subsystem are
now represented by MDL_savepoint class.
Also introduced Open_table_context::m_has_protection_against_grl
member which allows to avoid acquiring protection against GRL
while opening tables if such protection was already acquired.
sql/sql_class.cc:
Changed THD::leave_locked_tables_mode() after transactional
sentinel for metadata locks was obsoleted by introduction of
locks with explicit duration.
sql/sql_class.h:
- Adjusted code to the fact that savepoints for MDL subsystem
are now represented by MDL_savepoint class.
- Changed Global_read_lock class according to changes in
global read lock implementation:
* wait_if_global_read_lock and start_waiting_global_read_lock
are now gone. Instead code needing protection against GRL
has to acquire global IX metadata lock with statement
duration itself. To help it new can_acquire_protection()
was introduced. Also as result of the above change
m_protection_count member is gone too.
* Added m_mdl_blocks_commits_lock member to store metadata
lock blocking commits.
* Adjusted code to the fact that concept of transactional
sentinel was obsoleted by concept of lock duration.
- Removed CF_PROTECT_AGAINST_GRL flag as it is no longer
necessary. New GRL implementation acquires protection
against global read lock automagically when statement
acquires metadata locks on tables or other objects it
is going to change.
sql/sql_db.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/sql_handler.cc:
Removed call to broadcast_refresh() function. It is no longer
needed with new GRL implementation.
Adjusted code after introducing duration concept for metadata
locks. Particularly to the fact transactional sentinel was
replaced with explicit duration.
sql/sql_handler.h:
Renamed mysql_ha_move_tickets_after_trans_sentinel() to
mysql_ha_set_explicit_lock_duration() after transactional
sentinel was obsoleted by locks with explicit duration.
sql/sql_insert.cc:
Adjusted code handling delaying inserts after switching to
new GRL implementation. Now connection thread initiating
delayed insert has to acquire global IX lock in addition
to metadata lock on table being inserted into. This IX lock
protects against GRL and similarly to SW lock on table being
inserted into has to be passed to handler thread in order to
avoid deadlocks.
sql/sql_lex.cc:
LEX::protect_against_global_read_lock member is no longer
necessary since protection against GRL is automatically
taken by code acquiring metadata locks/opening tables.
sql/sql_lex.h:
LEX::protect_against_global_read_lock member is no longer
necessary since protection against GRL is automatically
taken by code acquiring metadata locks/opening tables.
sql/sql_parse.cc:
- Implemented support for new approach to acquiring protection
against global read lock. We no longer acquire such protection
explicitly on the basis of statement flags. Instead we always
rely on code which is responsible for acquiring metadata locks
on object to be changed acquiring this protection. This is
achieved by acquiring global IX metadata lock with statement
duration. This lock is automatically released at the end of
statement execution.
- Changed implementation of CREATE/DROP PROCEDURE/FUNCTION not
to release metadata locks and thus protection against of GRL
in the middle of statement execution.
- Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request and to the fact that
savepoints for MDL subsystem are now represented by
MDL_savepoint class.
sql/sql_prepare.cc:
Adjusted code to the to the fact that savepoints for MDL
subsystem are now represented by MDL_savepoint class.
sql/sql_rename.cc:
With new GRL implementation there is no need to explicitly
acquire protection against GRL before renaming tables.
This happens automatically in code which acquires metadata
locks on tables being renamed.
sql/sql_show.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request and to the fact that
savepoints for MDL subsystem are now represented by
MDL_savepoint class.
sql/sql_table.cc:
- With new GRL implementation there is no need to explicitly
acquire protection against GRL before dropping tables.
This happens automatically in code which acquires metadata
locks on tables being dropped.
- Changed mysql_alter_table() not to release lock on new table
name explicitly and to rely on automatic release of locks
at the end of statement instead. This was necessary since
now MDL_context::release_lock() is supported only for locks
for explicit duration.
sql/sql_trigger.cc:
With new GRL implementation there is no need to explicitly
acquire protection against GRL before changing table triggers.
This happens automatically in code which acquires metadata
locks on tables which triggers are to be changed.
sql/sql_update.cc:
Fix bug exposed by GRL testing. During prepare phase acquire
only S metadata locks instead of SW locks to keep prepare of
multi-UPDATE compatible with concurrent LOCK TABLES WRITE
and global read lock.
sql/sql_view.cc:
With new GRL implementation there is no need to explicitly
acquire protection against GRL before creating view.
This happens automatically in code which acquires metadata
lock on view to be created.
sql/sql_yacc.yy:
LEX::protect_against_global_read_lock member is no longer
necessary since protection against GRL is automatically
taken by code acquiring metadata locks/opening tables.
sql/table.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/table.h:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/transaction.cc:
Replaced custom implementation of global read lock with
one based on metadata locks. Consequently when doing
commit instead of calling method of Global_read_lock
class to acquire protection against GRL we simply acquire
IX in COMMIT namespace.
Also adjusted code to the fact that MDL savepoint is now
represented by MDL_savepoint class.
bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ
LOCK" and bug #54673 "It takes too long to get readlock for
'FLUSH TABLES WITH READ LOCK'".
The first bug manifested itself as a deadlock which occurred
when a connection, which had some table open through HANDLER
statement, tried to update some data through DML statement
while another connection tried to execute FLUSH TABLES WITH
READ LOCK concurrently.
What happened was that FTWRL in the second connection managed
to perform first step of GRL acquisition and thus blocked all
upcoming DML. After that it started to wait for table open
through HANDLER statement to be flushed. When the first connection
tried to execute DML it has started to wait for GRL/the second
connection creating deadlock.
The second bug manifested itself as starvation of FLUSH TABLES
WITH READ LOCK statements in cases when there was a constant
stream of concurrent DML statements (in two or more
connections).
This has happened because requests for protection against GRL
which were acquired by DML statements were ignoring presence of
pending GRL and thus the latter was starved.
This patch solves both these problems by re-implementing GRL
using metadata locks.
Similar to the old implementation acquisition of GRL in new
implementation is two-step. During the first step we block
all concurrent DML and DDL statements by acquiring global S
metadata lock (each DML and DDL statement acquires global IX
lock for its duration). During the second step we block commits
by acquiring global S lock in COMMIT namespace (commit code
acquires global IX lock in this namespace).
Note that unlike in old implementation acquisition of
protection against GRL in DML and DDL is semi-automatic.
We assume that any statement which should be blocked by GRL
will either open and acquires write-lock on tables or acquires
metadata locks on objects it is going to modify. For any such
statement global IX metadata lock is automatically acquired
for its duration.
The first problem is solved because waits for GRL become
visible to deadlock detector in metadata locking subsystem
and thus deadlocks like one in the first bug become impossible.
The second problem is solved because global S locks which
are used for GRL implementation are given preference over
IX locks which are acquired by concurrent DML (and we can
switch to fair scheduling in future if needed).
Important change:
FTWRL/GRL no longer blocks DML and DDL on temporary tables.
Before this patch behavior was not consistent in this respect:
in some cases DML/DDL statements on temporary tables were
blocked while in others they were not. Since the main use cases
for FTWRL are various forms of backups and temporary tables are
not preserved during backups we have opted for consistently
allowing DML/DDL on temporary tables during FTWRL/GRL.
Important change:
This patch changes thread state names which are used when
DML/DDL of FTWRL is waiting for global read lock. It is now
either "Waiting for global read lock" or "Waiting for commit
lock" depending on the stage on which FTWRL is.
Incompatible change:
To solve deadlock in events code which was exposed by this
patch we have to replace LOCK_event_metadata mutex with
metadata locks on events. As result we have to prohibit
DDL on events under LOCK TABLES.
This patch also adds extensive test coverage for interaction
of DML/DDL and FTWRL.
Performance of new and old global read lock implementations
in sysbench tests were compared. There were no significant
difference between new and old implementations.
in different default schema.
In strict mode, when data truncation or conversion happens,
THD::killed is set to THD::KILL_BAD_DATA.
This is abuse of KILL mechanism to guarantee that execution
of statement is aborted.
The stored procedures execution, on the other hand,
upon detection that a connection was killed, would
terminate immediately, without trying to restore the caller's
context, in particular, restore the caller's current schema.
The fix is, when terminating a stored procedure execution,
to only bypass cleanup if the entire connection was killed,
not in case of other forms of KILL.
mysql-test/r/sp-bugs.result:
Added result for a test case for bug#54375.
mysql-test/t/sp-bugs.test:
Added test case for bug#54375.
sql/sp_head.cc:
sp_head::execute modified: restore saved current db if
connection is not killed.
in different default schema.
In strict mode, when data truncation or conversion happens,
THD::killed is set to THD::KILL_BAD_DATA.
This is abuse of KILL mechanism to guarantee that execution
of statement is aborted.
The stored procedures execution, on the other hand,
upon detection that a connection was killed, would
terminate immediately, without trying to restore the caller's
context, in particular, restore the caller's current schema.
The fix is, when terminating a stored procedure execution,
to only bypass cleanup if the entire connection was killed,
not in case of other forms of KILL.
The problem was that the warnings risen by a trigger were not cleared upon
successful completion. The warnings should be cleared if the trigger completes
successfully.
The fix is to skip merging warnings into caller's Warning Info for triggers.
The problem was that the warnings risen by a trigger were not cleared upon
successful completion. The warnings should be cleared if the trigger completes
successfully.
The fix is to skip merging warnings into caller's Warning Info for triggers.
set to 128k.
sql/sp.cc:
Added checking for stack overrun at functions
db_load_routine/sp_find_routine.
sql/sp_head.cc:
sp_head::execute() modified: pass constant value STACK_MIN_SIZE
instead of 8 * STACK_MIN_SIZE as second argument value
in call to check_stack_overrun. Added checking for stack overrun
at functions sp_lex_keeper::reset_lex_and_exec_core/sp_instr_stmt::execute.
sql/sql_parse.cc:
check_stack_overrun modified: allocate buffer for error message
at heap instead of stack.
parse_sql modified: added call to check_stack_overrun() before
parsing of sql statement.
