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* WL#5030: Split and remove mysql_priv.hMats Kindahl2010-03-311-2750/+0
| | | | | | | | | | | | | | This patch: - Moves all definitions from the mysql_priv.h file into header files for the component where the variable is defined - Creates header files if the component lacks one - Eliminates all include directives from mysql_priv.h - Eliminates all circular include cycles - Rename time.cc to sql_time.cc - Rename mysql_priv.h to sql_priv.h
* Manual merge of mysql-trunk into mysql-trunk-merge.Alexey Kopytov2010-03-241-243/+500
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: Text conflict in client/mysqlbinlog.cc Text conflict in mysql-test/Makefile.am Text conflict in mysql-test/collections/default.daily Text conflict in mysql-test/r/mysqlbinlog_row_innodb.result Text conflict in mysql-test/suite/rpl/r/rpl_typeconv_innodb.result Text conflict in mysql-test/suite/rpl/t/rpl_get_master_version_and_clock.test Text conflict in mysql-test/suite/rpl/t/rpl_row_create_table.test Text conflict in mysql-test/suite/rpl/t/rpl_slave_skip.test Text conflict in mysql-test/suite/rpl/t/rpl_typeconv_innodb.test Text conflict in mysys/charset.c Text conflict in sql/field.cc Text conflict in sql/field.h Text conflict in sql/item.h Text conflict in sql/item_func.cc Text conflict in sql/log.cc Text conflict in sql/log_event.cc Text conflict in sql/log_event_old.cc Text conflict in sql/mysqld.cc Text conflict in sql/rpl_utility.cc Text conflict in sql/rpl_utility.h Text conflict in sql/set_var.cc Text conflict in sql/share/Makefile.am Text conflict in sql/sql_delete.cc Text conflict in sql/sql_plugin.cc Text conflict in sql/sql_select.cc Text conflict in sql/sql_table.cc Text conflict in storage/example/ha_example.h Text conflict in storage/federated/ha_federated.cc Text conflict in storage/myisammrg/ha_myisammrg.cc Text conflict in storage/myisammrg/myrg_open.c
| * A post-review fix for type-aware metadata locks.Konstantin Osipov2010-03-161-9/+7
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DDL no longer aborts mysql_lock_tables(), and hence we no longer need to support need_reopen flag of this call. Remove the flag, and all the code in the server that was responsible for handling the case when it was set. This allowed to simplify: open_and_lock_tables_derived(), the delayed thread, multi-update. Rename MYSQL_LOCK_IGNORE_FLUSH to MYSQL_OPEN_IGNORE_FLUSH, since we now only support this flag in open_table(). Rename MYSQL_LOCK_PERF_SCHEMA to MYSQL_LOCK_LOG_TABLE, to avoid confusion. Move the wait for the global read lock for cases when we do updates in SELECT f1() or DO (UPDATE) to open_table() from mysql_lock_tables(). When waiting for the read lock, we could raise need_reopen flag, which is no longer present in mysql_lock_tables(). Since the block responsible for waiting for GRL was moved, MYSQL_LOCK_IGNORE_GLOBAL_READ_LOCK was renamed to MYSQL_OPEN_IGNORE_GLOBAL_READ_LOCK. mysql-test/r/mdl_sync.result: Update test results (see comments for mdl_sync.test). mysql-test/t/mdl_sync.test: Update tests: an abort mysql_lock_tables() called for an INSERT no longer auto-closes SQL HANDLERS, since it no longer leads to back-off and retry. sql/ha_ndbcluster_binlog.cc: Remove unused variables. sql/lock.cc: Remove support for need_reopen parameter of mysql_lock_tables(). Update comments. sql/log_event_old.cc: Remove the loop responsible for handling need_reopen out parameter of mysql_lock_tables(). sql/mysql_priv.h: Update open and lock tables flag names. sql/share/errmsg-utf8.txt: Add a new error message to report when thr_multi_lock() is aborted. sql/sql_base.cc: Update comments. Rename MYSQL_LOCK_IGNORE_FLUSH to MYSQL_OPEN_IGNORE_FLUSH. sql/sql_class.h: Remove unused code. sql/sql_db.cc: Remove an unused bit of code. sql/sql_handler.cc: For backward compatibility, we still want to back off and retry when a call to mysql_lock_tables() is aborted from within an SQL HANDLER. Write an internal error handler to support the case. sql/sql_insert.cc: Call mysql_lock_tables() no longer has need_reopen out parameter. Simplify the code by removing the crud that took care of it. MYSQL_LOCK_IGNORE_FLUSH is now only supported by open_tables(). sql/sql_show.cc: Rename MYSQL_LOCK_IGNORE_FLUSH to MYSQL_OPEN_IGNORE_FLUSH sql/sql_table.cc: Remove an unused parameter. sql/sql_update.cc: Remove the need_reopen loop from multi-update. We no also longer need to cleanup the parse tree in case when mysql_lock_tables() is aborted and thus an infinite source of multi-update bugs is gone. sql/tztime.cc: Rename MYSQL_LOCK_IGNORE_FLUSH to MYSQL_OPEN_IGNORE_FLUSH, since from now on this flag is only supported by open_table().
| | * A review comment for the fix for Bug#46672.Konstantin Osipov2010-03-131-4/+2
| |/ | | | | | | Remove unnecessary need_reopen loops.
| * Fix for BUG#51215 "log-error partially works with version 5.5": WL 4738 ↵Guilhem Bichot2010-03-051-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (reengineering of server variables) had broken the 5.1 behaviour of --log-error: --log-error without argument sent to stderr instead of writing to a file with an autogenerated name. mysql-test/suite/sys_vars/t/log_error_func.test: test that error log is created and shown in SHOW VARIABLES. Interestingly the error log's path is apparently relative if --log-error=argument is used, but may be absolute or relative if --log-error(no argument) is used (because then the path is derived from that of pidfile_name, which can be absolute or relative, depending on if autogenerated or not). mysql-test/suite/sys_vars/t/log_error_func2.test: test that error log is created and shown in SHOW VARIABLES mysql-test/suite/sys_vars/t/log_error_func3.test: test that error log is empty in SHOW VARIABLES sql/mysql_priv.h: id for option --log-error sql/mysqld.cc: No --log-error means "write errors to stderr", whereas --log-error without argument means "write errors to a file". So we cannot use the default logic of class sys_var_charptr, which treats "option not used" the same as "option used without argument" and uses the same default for both. We need to catch "option used", in mysqld_get_one_option(), and then "without argument". Setting to "" makes sure that init_server_components() will create the log, with an autogenerated name. sql/sys_vars.cc: need to give the option a numeric id so that we can catch it in mysqld_get_one_option()
| * A follow-up on WL#5154 and WL#5182: remove forgotten options.Alexander Nozdrin2010-03-031-1/+1
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| * Manual merge from mysql-next-mr.Alexander Nozdrin2010-03-021-4/+26
| |\ | | | | | | | | | | | | Conflicts: - sql/sql_base.cc
| | * Manual merge from mysql-next-mr.Alexander Nozdrin2010-03-011-3/+25
| | |\ | | | | | | | | | | | | | | | | Conflicts: - sql/item.cc
| | | * Mergine from mysql-next-meAlexander Barkov2010-02-271-107/+114
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| | | * | WL#2649 Number-to-string conversionsAlexander Barkov2010-02-111-3/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | added: include/ctype_numconv.inc mysql-test/include/ctype_numconv.inc mysql-test/r/ctype_binary.result mysql-test/t/ctype_binary.test Adding tests modified: mysql-test/r/bigint.result mysql-test/r/case.result mysql-test/r/create.result mysql-test/r/ctype_cp1251.result mysql-test/r/ctype_latin1.result mysql-test/r/ctype_ucs.result mysql-test/r/func_gconcat.result mysql-test/r/func_str.result mysql-test/r/metadata.result mysql-test/r/ps_1general.result mysql-test/r/ps_2myisam.result mysql-test/r/ps_3innodb.result mysql-test/r/ps_4heap.result mysql-test/r/ps_5merge.result mysql-test/r/show_check.result mysql-test/r/type_datetime.result mysql-test/r/type_ranges.result mysql-test/r/union.result mysql-test/suite/ndb/r/ps_7ndb.result mysql-test/t/ctype_cp1251.test mysql-test/t/ctype_latin1.test mysql-test/t/ctype_ucs.test mysql-test/t/func_str.test Fixing tests @ sql/field.cc - Return str result using my_charset_numeric. - Using real multi-byte aware str_to_XXX functions to handle tricky charset values propely (e.g. UCS2) @ sql/field.h - Changing derivation of non-string field types to DERIVATION_NUMERIC. - Changing binary() for numeric/datetime fields to always return TRUE even if charset is not my_charset_bin. We need this to keep ha_base_keytype() return HA_KEYTYPE_BINARY. - Adding BINARY_FLAG into some fields, because it's not being set automatically anymore with "my_charset_bin to my_charset_numeric" change. - Changing derivation for numeric/datetime datatypes to a weaker value, to make "SELECT concat('string', field)" use character set of the string literal for the result of the function. @ sql/item.cc - Implementing generic val_str_ascii(). - Using max_char_length() instead of direct read of max_length to make "tricky" charsets like UCS2 work. NOTE: in the future we'll possibly remove all direct reads of max_length - Fixing Item_num::safe_charset_converter(). Previously it alligned binary string to character string (for example by adding leading 0x00 when doing binary->UCS2 conversion). Now it just converts from my_charset_numbner to "tocs". - Using val_str_ascii() in Item::get_time() to make UCS2 arguments work. - Other misc changes @ sql/item.h - Changing MY_COLL_CMP_CONV and MY_COLL_ALLOW_CONV to bit operations instead of hard-coded bit masks. - Addding new method DTCollation.set_numeric(). - Adding new methods to Item. - Adding helper functions to make code look nicer: agg_item_charsets_for_string_result() agg_item_charsets_for_comparison() - Changing charset for Item_num-derived items from my_charset_bin to my_charset_numeric (which is an alias for latin1). @ sql/item_cmpfunc.cc - Using new helper functions - Other misc changes @ sql/item_cmpfunc.h - Fixing strcmp() to return max_length=2. Previously it returned 1, which was wrong, because it did not fit '-1'. @ sql/item_func.cc - Using new helper functions - Other minor changes @ sql/item_func.h - Removing unused functions - Adding helper functions agg_arg_charsets_for_string_result() agg_arg_charsets_for_comparison() - Adding set_numeric() into constructors of numeric items. - Using fix_length_and_charset() and fix_char_length() instead of direct write to max_length. @ sql/item_geofunc.cc - Changing class for Item_func_geometry_type and Item_func_as_wkt from Item_str_func to Item_str_ascii_func, to make them return UCS2 result properly (when character_set_connection=ucs2). @ sql/item_geofunc.h - Changing class for Item_func_geometry_type and Item_func_as_wkt from Item_str_func to Item_str_ascii_func, to make them return UCS2 result properly (when @@character_set_connection=ucs2). @ sql/item_strfunc.cc - Implementing Item_str_func::val_str(). - Renaming val_str to val_str_ascii for some items, to make them work with UCS2 properly. - Using new helper functions - All single-argument functions that expect string result now call this method: agg_arg_charsets_for_string_result(collation, args, 1); This enables character set conversion to @@character_set_connection in case of pure numeric input. @ sql/item_strfunc.h - Introducing Item_str_ascii_func - for functions which return pure ASCII data, for performance purposes, as well as for the cases when the old implementation of val_str() was heavily 8-bit oriented and implementing a UCS2-aware version is tricky. @ sql/item_sum.cc - Using new helper functions. @ sql/item_timefunc.cc - Using my_charset_numeric instead of my_charset_bin. - Using fix_char_length(), fix_length_and_charset() and fix_length_and_charset_datetime() instead of direct write to max_length. - Using tricky-charset aware function str_to_time_with_warn() @ sql/item_timefunc.h - Using new helper functions for charset and length initialization. - Changing base class for Item_func_get_format() to make it return UCS2 properly (when character_set_connection=ucs2). @ sql/item_xmlfunc.cc - Using new helper function @ sql/my_decimal.cc - Adding a new DECIMAL to CHAR converter with real multibyte support (e.g. UCS2) @ sql/mysql_priv.h - Introducing a new derivation level for numeric/datetime data types. - Adding macros for my_charset_numeric and MY_REPERTOIRE_NUMERIC. - Adding prototypes for str_set_decimal() - Adding prototypes for character-set aware str_to_xxx() functions. @ sql/protocol.cc - Changing charsetnr to "binary" client-side metadata for numeric/datetime data types. @ sql/time.cc - Adding to_ascii() helper function, to convert a string in any character set to ascii representation. In the future can be extended to understand digits written in various non-Latin word scripts. - Adding real multy-byte character set aware versions for str_to_XXXX, to make these these type of queries work correct: INSERT INTO t1 SET datetime_column=ucs2_expression; @ strings/ctype-ucs2.c - endptr was not calculated correctly. INSERTing of UCS2 values into numeric columns returned warnings about truncated wrong data.
| | * | | Manual merge from mysql-trunk-merge.Alexander Nozdrin2010-02-241-1/+1
| | |\ \ \ | | | |_|/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: - client/mysql.cc - client/mysqldump.c - configure.in - mysql-test/r/csv.result - mysql-test/r/func_time.result - mysql-test/r/show_check.result - mysql-test/r/sp-error.result - mysql-test/r/sp.result - mysql-test/r/sp_trans.result - mysql-test/r/type_blob.result - mysql-test/r/type_timestamp.result - mysql-test/r/warnings.result - mysql-test/suite/rpl/r/rpl_sp.result - sql/mysql_priv.h - sql/mysqld.cc - sql/sp.cc - sql/sql_base.cc - sql/sql_table.cc - sql/sql_trigger.cc - sql/sql_view.cc - sql/table.h - sql/share/errmsg.txt - mysql-test/suite/sys_vars/r/log_bin_trust_routine_creators_basic.result
| * | | | merging to 6.0-codebase-bugfixing from a local branchAndrei Elkin2010-02-281-1/+2
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| | * | | | Bug #50296 Slave reconnects earlier than the prescribed slave_net_timeout valueAndrei Elkin2010-02-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There was auto-reconnecting by slave earlier than a prescribed by slave_net_timeout value. The issue happened on 64bit solaris that spotted rather incorrect casting of the ulong slave_net_timeout into the uint of mysql.options.read_timeout. Notice, that there is no reason for slave_net_timeout to be of type of ulong. Since it's primarily passed as arg to mysql_options the type can be made as uint to avoid all conversion hassles. That's what the fixes are made. A "side" effect of the patch is a new value for the max of slave_net_timeout to be the max of the unsigned int type (therefore to vary across platforms). Note, a regression test can't be made to run reliably without making it to last over some 20 secs. That's why it is placed in suite/large_tests. mysql-test/suite/large_tests/r/rpl_slave_net_timeout.result: the new test results. mysql-test/suite/large_tests/t/rpl_slave_net_timeout-slave.opt: Initialization of the option that yields slave_net_timeout's default. sql/mysql_priv.h: changing type for slave_net_timeout from ulong to uint sql/mysqld.cc: changing type for slave_net_timeout from ulong to uint sql/sys_vars.cc: Refining the max value for slave_net_timeout to be as the max for uint type.
| * | | | | Followup to Bug#45225 Locking: hang if drop table with no timeoutJon Olav Hauglid2010-02-241-17/+13
| | |/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch prevents system threads and system table accesses from using user-specified values for "lock_wait_timeout". Instead all such accesses are done using the default value (1 year). This prevents background tasks (such as replication, events, accessing stored function definitions, logging, reading time-zone information, etc.) from failing in cases where the global value of "lock_wait_timeout" is set very low. The patch also simplifies the open tables API. Rather than adding another convenience function for opening and locking system tables, this patch removes most of the existing convenience functions for open_and_lock_tables_derived(). Before, open_and_lock_tables() was a convenience function that enforced derived tables handling, while open_and_lock_tables_derived() was the main function where derived tables handling was optional. Now, this convencience function is gone and the main function is renamed to open_and_lock_tables(). No test case added as it would have required the use of --sleep to check that system threads and system tables have a different timeout value from the user-specified "lock_wait_timeout" system variable.
| * | | | merge, CMake bugfixes, remove sp-error from experimentalVladislav Vaintroub2010-02-231-2/+2
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| * \ \ \ \ Auto-merge from mysql-next-mr.Alexander Nozdrin2010-02-211-1/+2
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| | * | | | Patch for WL#3736: Extended Table, Column and Index Comments.Alexander Nozdrin2010-02-201-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The task is to (a) add a comment on indexes and (b) increase the maximum length of column, table and the new index comments. The patch committed on behalf of Yoshinori Matsunobu (Yoshinori.Matsunobu@Sun.COM).
| * | | | | Auto-merge from mysql-next-mr.Alexander Nozdrin2010-02-201-95/+104
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| | * | | | Manual merge from mysql-next-mr.Alexander Nozdrin2010-02-151-0/+1
| | |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: - sql/log_event.cc - sql/sql_class.h
| | * | | | | Fix for bug #50908 "Assertion `handler_tables_hash.records == 0' Dmitry Lenev2010-02-121-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | failed in enter_locked_tables_mode". Server was aborted due to assertion failure when one tried to execute statement requiring prelocking (i.e. firing triggers or using stored functions) while having open HANDLERs. The problem was that THD::enter_locked_tables_mode() method which was called at the beginning of execution of prelocked statement assumed there are no open HANDLERs. It had to do so because corresponding THD::leave_locked_tables_mode() method was unable to properly restore MDL sentinel when leaving LOCK TABLES/prelocked mode in the presence of open HANDLERs. This patch solves this problem by changing the latter method to properly restore MDL sentinel and thus removing need for this assumption. As a side-effect, it lifts unjustified limitation by allowing to keep HANDLERs open when entering LOCK TABLES mode. mysql-test/include/handler.inc: Adjusted tests after making LOCK TABLES not to close open HANDLERs. Added coverage for bug #50908 "Assertion `handler_tables_hash.records == 0' failed in enter_locked_tables_mode". mysql-test/r/handler_innodb.result: Updated test results (see include/handler.inc). mysql-test/r/handler_myisam.result: Updated test results (see include/handler.inc). sql/mysql_priv.h: Introduced mysql_ha_move_tickets_after_trans_sentinel() routine which allows to move tickets for metadata locks corresponding to open HANDLERs after transaction sentinel. sql/sql_class.cc: Changed THD::leave_locked_tables_mode() to correctly restore MDL sentinel value in the presence of open HANDLERs. sql/sql_class.h: Removed assert from THD::enter_locked_tables_mode() as we no longer have to close HANDLERs when entering LOCK TABLES or prelocked modes. Instead we keep them open and correctly restore MDL sentinel value after leaving them. Removal of assert also fixes problem from the bug report. sql/sql_handler.cc: Introduced mysql_ha_move_tickets_after_trans_sentinel() routine which allows to move tickets for metadata locks corresponding to open HANDLERs after transaction sentinel. sql/sql_parse.cc: We no longer have to close HANDLERs when entering LOCK TABLES mode. Instead we keep them open and simply correctly restore MDL sentinel value after leaving this mode.
| | * | | | | Fix for bug #50913 "Deadlock between open_and_lock_tables_derivedDmitry Lenev2010-02-081-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | and MDL". Concurrent execution of a multi-DELETE statement and ALTER TABLE statement which affected one of the tables used in the multi-DELETE sometimes led to deadlock. Similar deadlocks might have occured when one performed INSERT/UPDATE/DELETE on a view and concurrently executed ALTER TABLE for the view's underlying table, or when one concurrently executed TRUNCATE TABLE for InnoDB table and ALTER TABLE for the same table. These deadlocks were caused by a discrepancy between types of metadata and thr_lock.cc locks acquired by those statements. What happened was that multi-DELETE/TRUNCATE/DML-through-the- view statement in the first connection acquired SR lock on a table, then ALTER TABLE would come in in the second connection and acquire SNW metadata lock and TL_WRITE_ALLOW_READ thr_lock.c lock and then would start waiting for the first connection during lock upgrade. After that the statement in the first connection would try to acquire TL_WRITE lock on table and would start waiting for the second connection, creating a deadlock. This patch solves this problem by ensuring that we acquire SW metadata lock in all cases in which we acquiring write thr_lock.c lock. This guarantees that deadlocks like the one described above won't occur since all lock conflicts in such situation are resolved within MDL subsystem. This patch also adds assert which should guarantee that such situations won't arise in future. mysql-test/r/lock_multi.result: Added main test for bug #50913 "Deadlock between open_and_lock_tables_derived and MDL". mysql-test/r/mdl_sync.result: Added additional coverage for bug #50913 "Deadlock between open_and_lock_tables_derived and MDL". mysql-test/t/lock_multi.test: Added main test for bug #50913 "Deadlock between open_and_lock_tables_derived and MDL". mysql-test/t/mdl_sync.test: Added additional coverage for bug #50913 "Deadlock between open_and_lock_tables_derived and MDL". sql/lock.cc: Added assert that enforces that when we are locking a non-temporary table we have an appropriate type of metadata lock on this table. sql/mysql_priv.h: Added separate flag for open_tables() to be able specify that SH metadata locks on table to be open should be acquired. We can no longer use MYSQL_LOCK_IGNORE_FLUSH flag for this as in addition to use in I_S implementation it is also used for opening system tables. Since in the latter case we also acquire thr_lock.c locks using SH metadata lock in it instead of SR or SW locks may lead to deadlock. sql/sql_base.cc: When opening tables don't interpret MYSQL_LOCK_IGNORE_FLUSH flag as request to acquire SH metadata locks. This flag is also used for opening system tables for which we also take thr_lock.c locks and thus proper metadata lock to take in this case is SR or SW lock (otherwise deadlocks can occur). In cases when SH lock is really required (e.g. when tables are open by I_S implementation) we rely on that newly introduced MYSQL_OPEN_FORCE_SHARED_HIGH_PRIO_MDL flag is used. sql/sql_delete.cc: mysql_truncate_by_delete(): Adjust type of metadata lock to be requested after changing type of thr_lock.c lock for table list element from one which was set in parser to TL_WRITE. This removes discrepancy between types of these locks which allowed deadlocks to creep in. sql/sql_handler.cc: When closing table which was open by HANDLER statement clear TABLE::open_by_handler flag. This allows to use this flag as a reliable indication that TABLE instance was open by HANDLER statement in assert which was added to mysql_lock_tables(). sql/sql_parse.cc: multi_delete_set_locks_and_link_aux_tables(): Adjust type of metadata lock to be requested after changing type of thr_lock.c lock for table list element from one which was set in parser to TL_WRITE. This removes discrepancy between types of these locks which allowed deadlocks to creep in. sql/sql_show.cc: Use newly introduced MYSQL_OPEN_FORCE_SHARED_HIGH_PRIO_MDL flag in order to acquire SH metadata locks when opening tables in I_S implementation. sql/sql_update.cc: Added comment explaining why in multi-update after deciding that we need weaker thr_lock.c lock on a table we don't downgrade metadata lock on it. sql/sql_view.cc: When merging view into main statement adjust type of metadata lock to be requested after changing type of thr_lock.c lock for table. This removes discrepancy between types of these locks which allowed deadlocks to creep in.
| | * | | | | Merge next-mr -> next-4284.Konstantin Osipov2010-02-061-2/+12
| | |\ \ \ \ \ | | | | |_|_|/ | | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mysql-test/t/disabled.def: Restore disabled ssl tests: SSL certificates were updated. Disable sp_sync.test, the test case can't work in next-4284. mysql-test/t/partition_innodb.test: Disable parsing of the test case for Bug#47343, the test can not work in next-4284. mysql-test/t/ps_ddl.test: Update results (CREATE TABLE IF NOT EXISTS takes into account existence of the temporary table).
| | * | | | | Merge next-mr -> next-4284.Konstantin Osipov2010-02-051-2/+3
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| | * | | | | | Merge next-mr -> next-4284.Konstantin Osipov2010-02-041-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cherry-pick a fix Bug#37148 from next-mr, to preserve file ids of the added files, and ensure that all the necessary changes have been pulled. Since initially Bug#37148 was null-merged into 6.0, the changeset that is now being cherry-picked was likewise null merged into next-4284. Now that Bug#37148 has been reapplied to 6.0, try to make it work with next-4284. This is also necessary to be able to pull other changes from 5.1-rep into next-4284. To resolve the merge issues use this changeset applied to 6.0: revid:jperkin@sun.com-20091216103628-ylhqf7s6yegui2t9 revno: 3776.1.1 committer: He Zhenxing <zhenxing.he@sun.com> branch nick: 6.0-codebase-bugfixing timestamp: Thu 2009-12-17 17:02:50 +0800 message: Fix merge problem with Bug#37148
| | * | | | | | Merge next-mr -> next-4284-merge.Konstantin Osipov2010-02-041-6/+8
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| | * \ \ \ \ \ \ Merge next-mr -> next-4284.Konstantin Osipov2010-02-041-0/+4
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| | * \ \ \ \ \ \ \ Merge next-mr -> next-4284.Konstantin Osipov2010-02-031-7/+10
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| | * \ \ \ \ \ \ \ \ Merge next-mr -> next-4284Konstantin Osipov2010-02-031-29/+102
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| | * \ \ \ \ \ \ \ \ \ Merge next-mr -> next-4284.Konstantin Osipov2010-02-031-60/+135
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| | * \ \ \ \ \ \ \ \ \ \ Merge next-mr -> next-4284. Konstantin Osipov2010-02-021-0/+1
| | |\ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix Bug#50555 "handler commands crash server in my_hash_first()" as a post-merge fix (the new handler tests are not passing otherwise). - in hash.c, don't call calc_hash if ! my_hash_inited(). - add tests and results for the test case for Bug#50555 mysys/hash.c: Assert that the hash is initialized when it's used. sql/set_var.cc: Check that the hash is initalized before using it (Bug#50555)
| | * \ \ \ \ \ \ \ \ \ \ \ Merge next-mr -> next-4284.Konstantin Osipov2010-02-021-10/+63
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| | * | | | | | | | | | | | | Implement new type-of-operation-aware metadata locks.Dmitry Lenev2010-02-011-10/+5
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| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a wait-for graph based deadlock detector to the MDL subsystem. Fixes bug #46272 "MySQL 5.4.4, new MDL: unnecessary deadlock" and bug #37346 "innodb does not detect deadlock between update and alter table". The first bug manifested itself as an unwarranted abort of a transaction with ER_LOCK_DEADLOCK error by a concurrent ALTER statement, when this transaction tried to repeat use of a table, which it has already used in a similar fashion before ALTER started. The second bug showed up as a deadlock between table-level locks and InnoDB row locks, which was "detected" only after innodb_lock_wait_timeout timeout. A transaction would start using the table and modify a few rows. Then ALTER TABLE would come in, and start copying rows into a temporary table. Eventually it would stumble on the modified records and get blocked on a row lock. The first transaction would try to do more updates, and get blocked on thr_lock.c lock. This situation of circular wait would only get resolved by a timeout. Both these bugs stemmed from inadequate solutions to the problem of deadlocks occurring between different locking subsystems. In the first case we tried to avoid deadlocks between metadata locking and table-level locking subsystems, when upgrading shared metadata lock to exclusive one. Transactions holding the shared lock on the table and waiting for some table-level lock used to be aborted too aggressively. We also allowed ALTER TABLE to start in presence of transactions that modify the subject table. ALTER TABLE acquires TL_WRITE_ALLOW_READ lock at start, and that block all writes against the table (naturally, we don't want any writes to be lost when switching the old and the new table). TL_WRITE_ALLOW_READ lock, in turn, would block the started transaction on thr_lock.c lock, should they do more updates. This, again, lead to the need to abort such transactions. The second bug occurred simply because we didn't have any mechanism to detect deadlocks between the table-level locks in thr_lock.c and row-level locks in InnoDB, other than innodb_lock_wait_timeout. This patch solves both these problems by moving lock conflicts which are causing these deadlocks into the metadata locking subsystem, thus making it possible to avoid or detect such deadlocks inside MDL. To do this we introduce new type-of-operation-aware metadata locks, which allow MDL subsystem to know not only the fact that transaction has used or is going to use some object but also what kind of operation it has carried out or going to carry out on the object. This, along with the addition of a special kind of upgradable metadata lock, allows ALTER TABLE to wait until all transactions which has updated the table to go away. This solves the second issue. Another special type of upgradable metadata lock is acquired by LOCK TABLE WRITE. This second lock type allows to solve the first issue, since abortion of table-level locks in event of DDL under LOCK TABLES becomes also unnecessary. Below follows the list of incompatible changes introduced by this patch: - From now on, ALTER TABLE and CREATE/DROP TRIGGER SQL (i.e. those statements that acquire TL_WRITE_ALLOW_READ lock) wait for all transactions which has *updated* the table to complete. - From now on, LOCK TABLES ... WRITE, REPAIR/OPTIMIZE TABLE (i.e. all statements which acquire TL_WRITE table-level lock) wait for all transaction which *updated or read* from the table to complete. As a consequence, innodb_table_locks=0 option no longer applies to LOCK TABLES ... WRITE. - DROP DATABASE, DROP TABLE, RENAME TABLE no longer abort statements or transactions which use tables being dropped or renamed, and instead wait for these transactions to complete. - Since LOCK TABLES WRITE now takes a special metadata lock, not compatible with with reads or writes against the subject table and transaction-wide, thr_lock.c deadlock avoidance algorithm that used to ensure absence of deadlocks between LOCK TABLES WRITE and other statements is no longer sufficient, even for MyISAM. The wait-for graph based deadlock detector of MDL subsystem may sometimes be necessary and is involved. This may lead to ER_LOCK_DEADLOCK error produced for multi-statement transactions even if these only use MyISAM: session 1: session 2: begin; update t1 ... lock table t2 write, t1 write; -- gets a lock on t2, blocks on t1 update t2 ... (ER_LOCK_DEADLOCK) - Finally, support of LOW_PRIORITY option for LOCK TABLES ... WRITE was abandoned. LOCK TABLE ... LOW_PRIORITY WRITE from now on has the same priority as the usual LOCK TABLE ... WRITE. SELECT HIGH PRIORITY no longer trumps LOCK TABLE ... WRITE in the wait queue. - We do not take upgradable metadata locks on implicitly locked tables. So if one has, say, a view v1 that uses table t1, and issues: LOCK TABLE v1 WRITE; FLUSH TABLE t1; -- (or just 'FLUSH TABLES'), an error is produced. In order to be able to perform DDL on a table under LOCK TABLES, the table must be locked explicitly in the LOCK TABLES list. mysql-test/include/handler.inc: Adjusted test case to trigger an execution path on which bug 41110 "crash with handler command when used concurrently with alter table" and bug 41112 "crash in mysql_ha_close_table/get_lock_data with alter table" were originally discovered. Left old test case which no longer triggers this execution path for the sake of coverage. Added test coverage for HANDLER SQL statements and type-aware metadata locks. Added a test for the global shared lock and HANDLER SQL. Updated tests to take into account that the old simple deadlock detection heuristics was replaced with a graph-based deadlock detector. mysql-test/r/debug_sync.result: Updated results (see debug_sync.test). mysql-test/r/handler_innodb.result: Updated results (see handler.inc test). mysql-test/r/handler_myisam.result: Updated results (see handler.inc test). mysql-test/r/innodb-lock.result: Updated results (see innodb-lock.test). mysql-test/r/innodb_mysql_lock.result: Updated results (see innodb_mysql_lock.test). mysql-test/r/lock.result: Updated results (see lock.test). mysql-test/r/lock_multi.result: Updated results (see lock_multi.test). mysql-test/r/lock_sync.result: Updated results (see lock_sync.test). mysql-test/r/mdl_sync.result: Updated results (see mdl_sync.test). mysql-test/r/sp-threads.result: SHOW PROCESSLIST output has changed due to the fact that waiting for LOCK TABLES WRITE now happens within metadata locking subsystem. mysql-test/r/truncate_coverage.result: Updated results (see truncate_coverage.test). mysql-test/suite/funcs_1/datadict/processlist_val.inc: SELECT FROM I_S.PROCESSLIST output has changed due to fact that waiting for LOCK TABLES WRITE now happens within metadata locking subsystem. mysql-test/suite/funcs_1/r/processlist_val_no_prot.result: SELECT FROM I_S.PROCESSLIST output has changed due to fact that waiting for LOCK TABLES WRITE now happens within metadata locking subsystem. mysql-test/suite/rpl/t/rpl_sp.test: Updated to a new SHOW PROCESSLIST state name. mysql-test/t/debug_sync.test: Use LOCK TABLES READ instead of LOCK TABLES WRITE as the latter no longer allows to trigger execution path involving waiting on thr_lock.c lock and therefore reaching debug sync-point covered by this test. mysql-test/t/innodb-lock.test: Adjusted test case to the fact that innodb_table_locks=0 option is no longer supported, since LOCK TABLES WRITE handles all its conflicts within MDL subsystem. mysql-test/t/innodb_mysql_lock.test: Added test for bug #37346 "innodb does not detect deadlock between update and alter table". mysql-test/t/lock.test: Added test coverage which checks the fact that we no longer support DDL under LOCK TABLES on tables which were locked implicitly. Adjusted existing test cases accordingly. mysql-test/t/lock_multi.test: Added test for bug #46272 "MySQL 5.4.4, new MDL: unnecessary deadlock". Adjusted other test cases to take into account the fact that waiting for LOCK TABLES ... WRITE now happens within MDL subsystem. mysql-test/t/lock_sync.test: Since LOCK TABLES ... WRITE now takes SNRW metadata lock for tables locked explicitly we have to implicitly lock InnoDB tables (through view) to trigger the table-level lock conflict between TL_WRITE and TL_WRITE_ALLOW_WRITE. mysql-test/t/mdl_sync.test: Added basic test coverage for type-of-operation-aware metadata locks. Also covered with tests some use cases involving HANDLER statements in which a deadlock could arise. Adjusted existing tests to take type-of-operation-aware MDL into account. mysql-test/t/multi_update.test: Update to a new SHOW PROCESSLIST state name. mysql-test/t/truncate_coverage.test: Adjusted test case after making LOCK TABLES WRITE to wait until transactions that use the table to be locked are completed. Updated to the changed name of DEBUG_SYNC point. sql/handler.cc: Global read lock functionality has been moved into a class. sql/lock.cc: Global read lock functionality has been moved into a class. Updated code to use the new MDL API. sql/mdl.cc: Introduced new type-of-operation aware metadata locks. To do this: - Changed MDL_lock to use one list for waiting requests and one list for granted requests. For each list, added a bitmap that holds information what lock types a list contains. Added a helper class MDL_lock::List to manipulate with granted and waited lists while keeping the bitmaps in sync with list contents. - Changed lock-compatibility functions to use bitmaps that define compatibility. - Introduced a graph based deadlock detector inspired by waiting_threads.c from Maria implementation. - Now that we have a deadlock detector, and no longer have a global lock to protect individual lock objects, but rather use an rw lock per object, removed redundant code for upgrade, and the global read lock. Changed the MDL API to no longer require the caller to acquire the global intention exclusive lock by means of a separate method. Removed a few more methods that became redundant. - Removed deadlock detection heuristic, it has been made obsolete by the deadlock detector. - With operation-type-aware metadata locks, MDL subsystem has become aware of potential conflicts between DDL and open transactions. This made it possible to remove calls to mysql_abort_transactions_with_shared_lock() from acquisition paths for exclusive lock and lock upgrade. Now we can simply wait for these transactions to complete without fear of deadlock. Function mysql_lock_abort() has also become unnecessary for all conflicting cases except when a DDL conflicts with a connection that has an open HANDLER. sql/mdl.h: Introduced new type-of-operation aware metadata locks. Introduced a graph based deadlock detector and supporting methods. Added comments. God rid of redundant API calls. Renamed m_lt_or_ha_sentinel to m_trans_sentinel, since now it guards the global read lock as well as LOCK TABLES and HANDLER locks. sql/mysql_priv.h: Moved the global read lock functionality into a class. Added MYSQL_OPEN_FORCE_SHARED_MDL flag which forces open_tables() to take MDL_SHARED on tables instead of metadata locks specified in the parser. We use this to allow PREPARE run concurrently in presence of LOCK TABLES ... WRITE. Added signature for find_table_for_mdl_ugprade(). sql/set_var.cc: Global read lock functionality has been moved into a class. sql/sp_head.cc: When creating TABLE_LIST elements for prelocking or system tables set the type of request for metadata lock according to the operation that will be performed on the table. sql/sql_base.cc: - Updated code to use the new MDL API. - In order to avoid locks starvation we take upgradable locks all at once. As result implicitly locked tables no longer get an upgradable lock. Consequently DDL and FLUSH TABLES for such tables is prohibited. find_write_locked_table() was replaced by find_table_for_mdl_upgrade() function. open_table() was adjusted to return TABLE instance with upgradable ticket when necessary. - We no longer wait for all locks on OT_WAIT back off action -- only on the lock that caused the wait conflict. Moreover, now we distinguish cases when we have to wait due to conflict in MDL and old version of table in TDC. - Upate mysql_notify_threads_having_share_locks() to only abort thr_lock.c waits of threads that have open HANDLERs, since lock conflicts with only these threads now can lead to deadlocks not detectable by the MDL deadlock detector. - Remove mysql_abort_transactions_with_shared_locks() which is no longer needed. sql/sql_class.cc: Global read lock functionality has been moved into a class. Re-arranged code in THD::cleanup() to simplify assert. sql/sql_class.h: Introduced class to incapsulate global read lock functionality. Now sentinel in MDL subsystem guards the global read lock as well as LOCK TABLES and HANDLER locks. Adjusted code accordingly. sql/sql_db.cc: Global read lock functionality has been moved into a class. sql/sql_delete.cc: We no longer acquire upgradable metadata locks on tables which are locked by LOCK TABLES implicitly. As result TRUNCATE TABLE is no longer allowed for such tables. Updated code to use the new MDL API. sql/sql_handler.cc: Inform MDL_context about presence of open HANDLERs. Since HANLDERs break MDL protocol by acquiring table-level lock while holding only S metadata lock on a table MDL subsystem should take special care about such contexts (Now this is the only case when mysql_lock_abort() is used). sql/sql_parse.cc: Global read lock functionality has been moved into a class. Do not take upgradable metadata locks when opening tables for CREATE TABLE SELECT as it is not necessary and limits concurrency. When initializing TABLE_LIST objects before adding them to the table list set the type of request for metadata lock according to the operation that will be performed on the table. We no longer acquire upgradable metadata locks on tables which are locked by LOCK TABLES implicitly. As result FLUSH TABLES is no longer allowed for such tables. sql/sql_prepare.cc: Use MYSQL_OPEN_FORCE_SHARED_MDL flag when opening tables during PREPARE. This allows PREPARE to run concurrently in presence of LOCK TABLES ... WRITE. sql/sql_rename.cc: Global read lock functionality has been moved into a class. sql/sql_show.cc: Updated code to use the new MDL API. sql/sql_table.cc: Global read lock functionality has been moved into a class. We no longer acquire upgradable metadata locks on tables which are locked by LOCK TABLES implicitly. As result DROP TABLE is no longer allowed for such tables. Updated code to use the new MDL API. sql/sql_trigger.cc: Global read lock functionality has been moved into a class. We no longer acquire upgradable metadata locks on tables which are locked by LOCK TABLES implicitly. As result CREATE/DROP TRIGGER is no longer allowed for such tables. Updated code to use the new MDL API. sql/sql_view.cc: Global read lock functionality has been moved into a class. Fixed results of wrong merge that led to misuse of GLR API. CREATE VIEW statement is not a commit statement. sql/table.cc: When resetting TABLE_LIST objects for PS or SP re-execution set the type of request for metadata lock according to the operation that will be performed on the table. Do the same in auxiliary function initializing metadata lock requests in a table list. sql/table.h: When initializing TABLE_LIST objects set the type of request for metadata lock according to the operation that will be performed on the table. sql/transaction.cc: Global read lock functionality has been moved into a class.
| | * | | | | | | | | | | | | Patch that changes metadata locking subsystem to use mutex per lock andDmitry Lenev2010-01-211-4/+4
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| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | condition variable per context instead of one mutex and one conditional variable for the whole subsystem. This should increase concurrency in this subsystem. It also opens the way for further changes which are necessary to solve such bugs as bug #46272 "MySQL 5.4.4, new MDL: unnecessary deadlock" and bug #37346 "innodb does not detect deadlock between update and alter table". Two other notable changes done by this patch: - MDL subsystem no longer implicitly acquires global intention exclusive metadata lock when per-object metadata lock is acquired. Now this has to be done by explicit calls outside of MDL subsystem. - Instead of using separate MDL_context for opening system tables/tables for purposes of I_S we now create MDL savepoint in the main context before opening tables and rollback to this savepoint after closing them. This means that it is now possible to get ER_LOCK_DEADLOCK error even not inside a transaction. This might happen in unlikely case when one runs DDL on one of system tables while also running DDL on some other tables. Cases when this ER_LOCK_DEADLOCK error is not justified will be addressed by advanced deadlock detector for MDL subsystem which we plan to implement. mysql-test/include/handler.inc: Adjusted handler_myisam.test and handler_innodb.test to the fact that exclusive metadata locks on tables are now acquired according to alphabetical order of fully qualified table names instead of order in which tables are mentioned in statement. mysql-test/r/handler_innodb.result: Adjusted handler_myisam.test and handler_innodb.test to the fact that exclusive metadata locks on tables are now acquired according to alphabetical order of fully qualified table names instead of order in which tables are mentioned in statement. mysql-test/r/handler_myisam.result: Adjusted handler_myisam.test and handler_innodb.test to the fact that exclusive metadata locks on tables are now acquired according to alphabetical order of fully qualified table names instead of order in which tables are mentioned in statement. mysql-test/r/mdl_sync.result: Adjusted mdl_sync.test to the fact that exclusive metadata locks on tables are now acquired according to alphabetical order of fully qualified table names instead of order in which tables are mentioned in statement. mysql-test/t/mdl_sync.test: Adjusted mdl_sync.test to the fact that exclusive metadata locks on tables are now acquired according to alphabetical order of fully qualified table names instead of order in which tables are mentioned in statement. sql/events.cc: Instead of using separate MDL_context for opening system tables we now create MDL savepoint in the main context before opening such tables and rollback to this savepoint after closing them. To support this change methods of THD responsible for saving/restoring open table state were changed to use Open_tables_backup class which in addition to Open_table_state has a member for this savepoint. As result code opening/closing system tables was changed to use Open_tables_backup instead of Open_table_state class as well. sql/ha_ndbcluster.cc: Since manipulations with open table state no longer install proxy MDL_context it does not make sense to perform them in order to satisfy assert in mysql_rm_tables_part2(). Removed them per agreement with Cluster team. This has not broken test suite since scenario in which deadlock can occur and assertion fails is not covered by tests. sql/lock.cc: MDL subsystem no longer implicitly acquires global intention exclusive metadata lock when per-object exclusive metadata lock is acquired. Now this has to be done by explicit calls outside of MDL subsystem. sql/log.cc: Instead of using separate MDL_context for opening system tables we now create MDL savepoint in the main context before opening such tables and rollback to this savepoint after closing them. To support this change methods of THD responsible for saving/restoring open table state were changed to use Open_tables_backup class which in addition to Open_table_state has a member for this savepoint. As result code opening/closing system tables was changed to use Open_tables_backup instead of Open_table_state class as well. sql/mdl.cc: Changed metadata locking subsystem to use mutex per lock and condition variable per context instead of one mutex and one conditional variable for the whole subsystem. Changed approach to handling of global metadata locks. Instead of implicitly acquiring intention exclusive locks when user requests per-object upgradeable or exclusive locks now we require them to be acquired explicitly in the same way as ordinary metadata locks. In fact global lock are now ordinary metadata locks in new GLOBAL namespace. To implement these changes: - Removed LOCK_mdl mutex and COND_mdl condition variable. - Introduced MDL_lock::m_mutex mutexes which protect individual lock objects. - Replaced mdl_locks hash with MDL_map class, which has hash for MDL_lock objects as a member and separate mutex which protects this hash. Methods of this class allow to find(), find_or_create() or remove() MDL_lock objects in concurrency-friendly fashion (i.e. for most common operation, find_or_create(), we don't acquire MDL_lock::m_mutex while holding MDL_map::m_mutex. Thanks to MikaelR for this idea and benchmarks!). Added three auxiliary members to MDL_lock class (m_is_destroyed, m_ref_usage, m_ref_release) to support this concurrency-friendly behavior. - Introduced MDL_context::m_ctx_wakeup_cond condition variable to be used for waiting until this context's pending request can be satisfied or its thread has to perform actions to resolve potential deadlock. Context which want to wait add ticket corresponding to the request to an appropriate queue of waiters in MDL_lock object so they can be noticed when other contexts change state of lock and be awaken by them by signalling on MDL_context::m_ctx_wakeup_cond. As consequence MDL_ticket objects has to be used for any waiting in metadata locking subsystem including one which happens in MDL_context::wait_for_locks() method. Another consequence is that MDL_context is no longer copyable and can't be saved/restored when working with system tables. - Made MDL_lock an abstract class, which delegates specifying exact compatibility matrix to its descendants. Added MDL_global_lock child class for global lock (The old is_lock_type_compatible() method became can_grant_lock() method of this class). Added MDL_object_lock class to represent per-object lock (The old MDL_lock::can_grant_lock() became its method). Choice between two classes happens based on MDL namespace in MDL_lock::create() method. - Got rid of MDL_lock::type member as its meaning became ambigous for global locks. - To simplify waking up of contexts waiting for lock split waiting queue in MDL_lock class in two queues. One for pending requests for exclusive (including intention exclusive) locks and another for requests for shared locks. - Added virtual wake_up_waiters() method to MDL_lock, MDL_global_lock and MDL_object_lock classes which allows to wake up waiting contexts after state of lock changes. Replaced old duplicated code with calls to this method. - Adjusted MDL_context::try_acquire_shared_lock()/exclusive_lock()/ global_shared_lock(), MDL_ticket::upgrade_shared_lock_to_exclusive_lock() and MDL_context::release_ticket() methods to use MDL_map and MDL_lock::m_mutex instead of single LOCK_mdl mutex and wake up waiters according to the approach described above. The latter method also was renamed to MDL_context::release_lock(). - Changed MDL_context::try_acquire_shared_lock()/exclusive_lock() and release_lock() not to handle global locks. They are now supposed to be taken explicitly like ordinary metadata locks. - Added helper MDL_context::try_acquire_global_intention_exclusive_lock() and acquire_global_intention_exclusive_lock() methods. - Moved common code from MDL_context::acquire_global_shared_lock() and acquire_global_intention_exclusive_lock() to new method - MDL_context::acquire_lock_impl(). - Moved common code from MDL_context::try_acquire_shared_lock(), try_acquire_global_intention_exclusive_lock()/exclusive_lock() to MDL_context::try_acquire_lock_impl(). - Since acquiring of several exclusive locks can no longer happen under single LOCK_mdl mutex the approach to it had to be changed. Now we do it in one by one fashion. This is done in alphabetical order to avoid deadlocks. Changed MDL_context::acquire_exclusive_locks() accordingly (as part of this change moved code responsible for acquiring single exclusive lock to new MDL_context::acquire_exclusive_lock_impl() method). - Since we no longer have single LOCK_mdl mutex which protects all MDL_context::m_is_waiting_in_mdl members using these members to determine if we have really awaken context holding conflicting shared lock became inconvinient. Got rid of this member and changed notify_shared_lock() helper function and process of acquiring of/upgrading to exclusive lock not to rely on such information. Now in MDL_context::acquire_exclusive_lock_impl() and MDL_ticket::upgrade_shared_lock_to_exclusive_lock() we simply re-try to wake up threads holding conflicting shared locks after small time out. - Adjusted MDL_context::can_wait_lead_to_deadlock() and MDL_ticket::has_pending_conflicting_lock() to use per-lock mutexes instead of LOCK_mdl. To do this introduced MDL_lock::has_pending_exclusive_lock() method. sql/mdl.h: Changed metadata locking subsystem to use mutex per lock and condition variable per context instead of one mutex and one conditional variable for the whole subsystem. In order to implement this change: - Added MDL_key::cmp() method to be able to sort MDL_key objects alphabetically. Changed length fields in MDL_key class to uint16 as 16-bit is enough for length of any key. - Changed MDL_ticket::get_ctx() to return pointer to non-const object in order to be able to use MDL_context::awake() method for such contexts. - Got rid of unlocked versions of can_wait_lead_to_deadlock()/ has_pending_conflicting_lock() methods in MDL_context and MDL_ticket. We no longer has single mutex which protects all locks. Thus one always has to use versions of these methods which acquire per-lock mutexes. - MDL_request_list type of list now counts its elements. - Added MDL_context::m_ctx_wakeup_cond condition variable to be used for waiting until this context's pending request can be satisfied or its thread has to perform actions to resolve potential deadlock. Added awake() method to wake up context from such wait. Addition of condition variable made MDL_context uncopyable. As result we no longer can save/restore MDL_context when working with system tables. Instead we create MDL savepoint before opening those tables and rollback to it once they are closed. - MDL_context::release_ticket() became release_lock() method. - Added auxiliary MDL_context::acquire_exclusive_lock_impl() method which does all necessary work to acquire exclusive lock on one object but should not be used directly as it does not enforce any asserts ensuring that no deadlocks are possible. - Since we no longer need to know if thread trying to acquire exclusive lock managed to wake up any threads having conflicting shared locks (as, anyway, we will try to wake up such threads again shortly) - MDL_context::m_is_waiting_in_mdl member became unnecessary and notify_shared_lock() no longer needs to be friend of MDL_context. Changed approach to handling of global metadata locks. Instead of implicitly acquiring intention exclusive locks when user requests per-object upgradeable or exclusive locks now we require them to be acquired explicitly in the same way as ordinary metadata locks. - Added new GLOBAL namespace for such locks. - Added new type of lock to be requested MDL_INTENTION_EXCLISIVE. - Added MDL_context::try_acquire_global_intention_exclusive_lock() and acquire_global_intention_exclusive_lock() methods. - Moved common code from MDL_context::acquire_global_shared_lock() and acquire_global_intention_exclusive_lock() to new method - MDL_context::acquire_lock_impl(). - Moved common code from MDL_context::try_acquire_shared_lock(), try_acquire_global_intention_exclusive_lock()/exclusive_lock() to MDL_context::try_acquire_lock_impl(). - Added helper MDL_context::is_global_lock_owner() method to be able easily to find what kind of global lock this context holds. - MDL_context::m_has_global_shared_lock became unnecessary as global read lock is now represented by ordinary ticket. - Removed assert in MDL_context::set_lt_or_ha_sentinel() which became false for cases when we execute LOCK TABLES under global read lock mode. sql/mysql_priv.h: Instead of using separate MDL_context for opening system tables we now create MDL savepoint in the main context before opening such tables and rollback to this savepoint after closing them. To support this change methods of THD responsible for saving/restoring open table state were changed to use Open_tables_backup class which in addition to Open_table_state has a member for this savepoint. As result calls opening/closing system tables were changed to use Open_tables_backup instead of Open_table_state class as well. sql/sp.cc: Instead of using separate MDL_context for opening system tables we now create MDL savepoint in the main context before opening such tables and rollback to this savepoint after closing them. To support this change methods of THD responsible for saving/restoring open table state were changed to use Open_tables_backup class which in addition to Open_table_state has a member for this savepoint. As result code opening/closing system tables was changed to use Open_tables_backup instead of Open_table_state class as well. sql/sp.h: Instead of using separate MDL_context for opening system tables we now create MDL savepoint in the main context before opening such tables and rollback to this savepoint after closing them. To support this change methods of THD responsible for saving/restoring open table state were changed to use Open_tables_backup class which in addition to Open_table_state has a member for this savepoint. As result code opening/closing system tables was changed to use Open_tables_backup instead of Open_table_state class as well. sql/sql_base.cc: close_thread_tables(): Since we no longer use separate MDL_context for opening system tables we need to avoid releasing all transaction locks when closing system table. Releasing metadata lock on system table is now responsibility of THD::restore_backup_open_tables_state(). open_table_get_mdl_lock(), Open_table_context::recover_from_failed_open(): MDL subsystem no longer implicitly acquires global intention exclusive metadata lock when per-object upgradable or exclusive metadata lock is acquired. So this have to be done explicitly from these calls. Changed Open_table_context class to store MDL_request object for global intention exclusive lock acquired when opening tables. open_table(): Do not release metadata lock if we have failed to open table as this lock might have been acquired by one of previous statements in transaction, and therefore should not be released. open_system_tables_for_read()/close_system_tables()/ open_performance_schema_table(): Instead of using separate MDL_context for opening system tables we now create MDL savepoint in the main context before opening such tables and rollback to this savepoint after closing them. To support this change methods of THD responsible for saving/restoring open table state were changed to use Open_tables_backup class which in addition to Open_table_state has a member for this savepoint. As result code opening/closing system tables was changed to use Open_tables_backup instead of Open_table_state class as well. close_performance_schema_table(): Got rid of duplicated code. sql/sql_class.cc: Instead of using separate MDL_context for opening system tables we now create MDL savepoint in the main context before opening such tables and rollback to this savepoint after closing them. To support this change methods of THD responsible for saving/restoring open table state were changed to use Open_tables_backup class which in addition to Open_table_state has a member for this savepoint. Also releasing metadata lock on system table is now responsibility of THD::restore_backup_open_tables_state(). Adjusted assert in THD::cleanup() to take into account fact that now we also use MDL sentinel for global read lock. sql/sql_class.h: Instead of using separate MDL_context for opening system tables we now create MDL savepoint in the main context before opening such tables and rollback to this savepoint after closing them. As result: - 'mdl_context' member was moved out of Open_tables_state to THD class. enter_locked_tables_mode()/leave_locked_tables_mode() had to follow. - Methods of THD responsible for saving/restoring open table state were changed to use Open_tables_backup class which in addition to Open_table_state has a member for this savepoint. Changed Open_table_context class to store MDL_request object for global intention exclusive lock acquired when opening tables. sql/sql_delete.cc: MDL subsystem no longer implicitly acquires global intention exclusive metadata lock when per-object exclusive metadata lock is acquired. Now this has to be done by explicit calls outside of MDL subsystem. sql/sql_help.cc: Instead of using separate MDL_context for opening system tables we now create MDL savepoint in the main context before opening such tables and rollback to this savepoint after closing them. To support this change methods of THD responsible for saving/restoring open table state were changed to use Open_tables_backup class which in addition to Open_table_state has a member for this savepoint. As result code opening/closing system tables was changed to use Open_tables_backup instead of Open_table_state class as well. sql/sql_parse.cc: Adjusted assert reload_acl_and_cache() to the fact that global read lock now takes full-blown metadata lock. sql/sql_plist.h: Added support for element counting to I_P_List list template. One can use policy classes to specify if such counting is needed or not needed for particular list. sql/sql_show.cc: Instead of using separate MDL_context for opening tables for I_S purposes we now create MDL savepoint in the main context before opening tables and rollback to this savepoint after closing them. To support this and similar change for system tables methods of THD responsible for saving/restoring open table state were changed to use Open_tables_backup class which in addition to Open_table_state has a member for this savepoint. As result code opening/closing tables for I_S purposes was changed to use Open_tables_backup instead of Open_table_state class as well. sql/sql_table.cc: mysql_rm_tables_part2(): Since now global intention exclusive metadata lock is ordinary metadata lock we no longer can rely that by releasing MDL locks on all tables we will release all locks acquired by this routine. So in non-LOCK-TABLES mode we have to release all locks acquired explicitly. prepare_for_repair(), mysql_alter_table(): MDL subsystem no longer implicitly acquires global intention exclusive metadata lock when per-object exclusive metadata lock is acquired. Now this has to be done by explicit calls outside of MDL subsystem. sql/tztime.cc: Instead of using separate MDL_context for opening system tables we now create MDL savepoint in the main context before opening such tables and rollback to this savepoint after closing them. To support this change methods of THD responsible for saving/restoring open table state were changed to use Open_tables_backup class which in addition to Open_table_state has a member for this savepoint. As result code opening/closing system tables was changed to use Open_tables_backup instead of Open_table_state class as well. Also changed code not to use special mechanism for open system tables when it is not really necessary.
| | * | | | | | | | | | | | | Implementation of simple deadlock detection for metadata locks.Dmitry Lenev2009-12-301-1/+2
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| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change is supposed to reduce number of ER_LOCK_DEADLOCK errors which occur when multi-statement transaction encounters conflicting metadata lock in cases when waiting is possible. The idea is not to fail ER_LOCK_DEADLOCK error immediately when we encounter conflicting metadata lock. Instead we release all metadata locks acquired by current statement and start to wait until conflicting lock go away. To avoid deadlocks we use simple empiric which aborts waiting with ER_LOCK_DEADLOCK error if it turns out that somebody is waiting for metadata locks owned by this transaction. This patch also fixes bug #46273 "MySQL 5.4.4 new MDL: Bug#989 is not fully fixed in case of ALTER". The bug was that concurrent execution of UPDATE or MULTI-UPDATE statement as a part of multi-statement transaction that already has used table being updated and ALTER TABLE statement might have resulted of loss of isolation between this transaction and ALTER TABLE statement, which manifested itself as changes performed by ALTER TABLE becoming visible in transaction and wrong binary log order as a consequence. This problem occurred when UPDATE or MULTI-UPDATE's wait in mysql_lock_tables() call was aborted due to metadata lock upgrade performed by concurrent ALTER TABLE. After such abort all metadata locks held by transaction were released but transaction silently continued to be executed as if nothing has happened. We solve this problem by changing our code not to release all locks in such case. Instead we release only locks which were acquired by current statement and then try to reacquire them by restarting open/lock tables process. We piggyback on simple deadlock detector implementation since this change has to be done anyway for it. mysql-test/include/handler.inc: After introduction of basic deadlock detector for metadata locks it became necessary to change parts of test for HANDLER statements which covered some of scenarios in which ER_LOCK_DEADLOCK error was detected in absence of real deadlock (with new deadlock detector this no longer happens). Also adjusted test to the fact that HANDLER READ for the table no longer will be blocked by ALTER TABLE for the same table which awaits for metadata lock upgrade (this is due to removal of mysql_lock_abort() from wait_while_table_is_used()). mysql-test/r/handler_innodb.result: After introduction of basic deadlock detector for metadata locks it became necessary to change parts of test for HANDLER statements which covered some of scenarios in which ER_LOCK_DEADLOCK error was detected in absence of real deadlock (with new deadlock detector this no longer happens). Also adjusted test to the fact that HANDLER READ for the table no longer will be blocked by ALTER TABLE for the same table which awaits for metadata lock upgrade (this is due to removal of mysql_lock_abort() from wait_while_table_is_used()). mysql-test/r/handler_myisam.result: After introduction of basic deadlock detector for metadata locks it became necessary to change parts of test for HANDLER statements which covered some of scenarios in which ER_LOCK_DEADLOCK error was detected in absence of real deadlock (with new deadlock detector this no longer happens). Also adjusted test to the fact that HANDLER READ for the table no longer will be blocked by ALTER TABLE for the same table which awaits for metadata lock upgrade (this is due to removal of mysql_lock_abort() from wait_while_table_is_used()). mysql-test/r/mdl_sync.result: Added test coverage for basic deadlock detection in metadata locking subsystem and for bug #46273 "MySQL 5.4.4 new MDL: Bug#989 is not fully fixed in case of ALTER". mysql-test/r/sp-lock.result: Adjusted test coverage for metadata locking for stored routines since after introduction of basic deadlock detector for metadata locks number of scenarios in which ER_LOCK_DEADLOCK error in absence of deadlock has decreased. mysql-test/t/mdl_sync.test: Added test coverage for basic deadlock detection in metadata locking subsystem and for bug #46273 "MySQL 5.4.4 new MDL: Bug#989 is not fully fixed in case of ALTER". mysql-test/t/sp-lock.test: Adjusted test coverage for metadata locking for stored routines since after introduction of basic deadlock detector for metadata locks number of scenarios in which ER_LOCK_DEADLOCK error in absence of deadlock has decreased. sql/log_event_old.cc: close_tables_for_reopen() now takes one more argument which specifies at which point it should stop releasing metadata locks acquired by this connection. sql/mdl.cc: Changed metadata locking subsystem to support basic deadlock detection with a help of the following simple empiric -- we assume that there is a deadlock if there is a connection which has to wait for a metadata lock which is currently acquired by some connection which is itself waiting to be able to acquire some shared metadata lock. To implement this change: - Added MDL_context::can_wait_lead_to_deadlock()/_impl() methods which allow to find out if there is someone waiting for metadata lock which is held by the connection and therefore deadlocks are possible if this connection is going to wait for some metadata lock. To do this added version of MDL_ticket::has_pending_conflicting_lock() method which assumes that its caller already owns LOCK_mdl mutex. - Changed MDL_context::wait_for_locks() to use one of the above methods to check if somebody is waiting for metadata lock owned by this context (and therefore deadlock is possible) and emit ER_LOCK_DEADLOCK error in this case. Also now we mark context of connections waiting inside of this method by setting MDL_context::m_is_waiting_in_mdl member. Thanks to this such connection could be waken up if some other connection starts waiting for one of its metadata locks and so a deadlock can occur. - Adjusted notify_shared_lock() to wake up connections which wait inside MDL_context::wait_for_locks() while holding shared metadata lock. - Changed MDL_ticket::upgrade_shared_lock_to_exclusive() to add temporary ticket for exclusive lock to MDL_lock::waiting queue, so request for metadata lock upgrade can be properly detected by our empiric. Also now this method invokes a callback which forces transactions holding shared metadata lock on the table to call MDL_context:: can_wait_lead_to_deadlock() method even if they don't need any new metadata locks. Thanks to this such transactions can detect deadlocks/ livelocks between MDL and table-level locks. Also reduced timeouts between calls to notify_shared_lock() in MDL_ticket::upgrade_shared_lock_to_exclusive() and MDL_context::acquire_exclusive_locks(). This was necessary to get rid of call to mysql_lock_abort() in wait_while_table_is_used(). (Now we instead rely on notify_shared_lock() timely calling mysql_lock_abort_for_thread() for the table on which lock is being upgraded/acquired). sql/mdl.h: - Added a version of MDL_ticket::has_pending_conflicting_lock() method to be used in situations when caller already has acquired LOCK_mdl mutex. - Added MDL_context::can_wait_lead_to_deadlock()/_impl() methods which allow to find out if there is someone waiting for metadata lock which is held by this connection and thus deadlocks are possible if this connections will start waiting for some metadata lock. - Added MDL_context::m_is_waiting_in_mdl member to mark connections waiting in MDL_context::wait_for_locks() method of metadata locking subsystem. Added getter method for this private member to make it accessible in notify_shared_lock() auxiliary so we can wake-up such connections if they hold shared metadata locks. - Finally, added mysql_abort_transactions_with_shared_lock() callback to be able force transactions which don't need any new metadata locks still call MDL_context::can_wait_lead_to_deadlock() and detect some of deadlocks between metadata locks and table-level locks. sql/mysql_priv.h: close_tables_for_reopen() now takes one more argument which specifies at which point it should stop releasing metadata locks acquired by this connection. sql/sql_base.cc: Changed approach to metadata locking for multi-statement transactions. We no longer fail ER_LOCK_DEADLOCK error immediately when we encounter conflicting metadata lock. Instead we release all metadata locks acquired by current statement and start to wait until conflicting locks to go away by calling MDL_context::wait_for_locks() method. To avoid deadlocks the latter implements simple empiric which aborts waiting with ER_LOCK_DEADLOCK error if it turns out that somebody is waiting for metadata locks owned by this transaction. To implement the change described above: - Introduced Open_table_context::m_start_of_statement_svp member to store state of metadata locks at the start of the statement. - Changed Open_table_context::request_backoff_action() not to fail with ER_LOCK_DEADLOCK immediately if back-off is requested due to conflicting metadata lock. - Added new argument for close_tables_for_reopen() procedure which allows to specify subset of metadata locks to be released. - Changed open_tables() not to release all metadata locks acquired by current transaction when metadata lock conflict is discovered. Instead we release only locks acquired by current statement. - Changed open_ltable() and open_and_lock_tables_derived() not to emit ER_LOCK_DEADLOCK error when mysql_lock_tables() is aborted in multi-statement transaction when somebody tries to acquire exclusive metadata lock on the table. Instead we release metadata locks acquired by current statement and try to wait until they can be re-acquired. - Adjusted tdc_wait_for_old_versions() to check if there is someone waiting for one of metadata locks held by this connection and run deadlock detection in order to avoid deadlocks in some situations. - Added mysql_abort_transactions_with_shared_lock() callback which allows to force transactions holding shared metadata lock on the table to call MDL_context::can_wait_lead_to_deadlock() even if they don't need any new metadata locks so they can detect potential deadlocks between metadata locking subsystem and table-level locks. - Adjusted wait_while_table_is_used() not to set TABLE::version to 0 as it is now done only when necessary by the above-mentioned callback. Also removed unnecessary call to mysql_lock_abort(). Instead we rely on code performing metadata lock upgrade aborting waits on the table-level lock for this table by calling mysql_lock_abort_for_thread() (invoked by mysql_notify_thread_having_shared_lock()). In future this should allow to reduce number of scenarios in which we produce ER_LOCK_DEADLOCK error even though no real deadlock exists. sql/sql_class.h: Introduced Open_table_context::m_start_of_statement_svp member to store state of metadata locks at the start of the statement. Replaced Open_table_context::m_can_deadlock member with m_has_locks member to reflect the fact that we no longer unconditionally emit ER_LOCK_DEADLOCK error for transaction having some metadata locks when conflicting metadata lock is discovered. sql/sql_insert.cc: close_tables_for_reopen() now takes one more argument which specifies at which point it should stop releasing metadata locks acquired by this connection. sql/sql_plist.h: Made I_P_List_iterator<T, B> usable with const lists. sql/sql_show.cc: close_tables_for_reopen() now takes one more argument which specifies at which point it should stop releasing metadata locks acquired by this connection. sql/sql_update.cc: Changed UPDATE and MULTI-UPDATE code not to release all metadata locks when calls to mysql_lock_tables() are aborted. Instead we release only locks which are acquired by this statement and then try to reacquire them by calling open_tables(). This solves bug #46273 "MySQL 5.4.4 new MDL: Bug#989 is not fully fixed in case of ALTER".
| | * | | | | | | | | | | | | Apply and review:Konstantin Osipov2009-12-291-0/+3
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| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 3655 Jon Olav Hauglid 2009-10-19 Bug #30977 Concurrent statement using stored function and DROP FUNCTION breaks SBR Bug #48246 assert in close_thread_table Implement a fix for: Bug #41804 purge stored procedure cache causes mysterious hang for many minutes Bug #49972 Crash in prepared statements The problem was that concurrent execution of DML statements that use stored functions and DDL statements that drop/modify the same function might result in incorrect binary log in statement (and mixed) mode and therefore break replication. This patch fixes the problem by introducing metadata locking for stored procedures and functions. This is similar to what is done in Bug#25144 for views. Procedures and functions now are locked using metadata locks until the transaction is either committed or rolled back. This prevents other statements from modifying the procedure/function while it is being executed. This provides commit ordering - guaranteeing serializability across multiple transactions and thus fixes the reported binlog problem. Note that we do not take locks for top-level CALLs. This means that procedures called directly are not protected from changes by simultaneous DDL operations so they are executed at the state they had at the time of the CALL. By not taking locks for top-level CALLs, we still allow transactions to be started inside procedures. This patch also changes stored procedure cache invalidation. Upon a change of cache version, we no longer invalidate the entire cache, but only those routines which we use, only when a statement is executed that uses them. This patch also changes the logic of prepared statement validation. A stored procedure used by a prepared statement is now validated only once a metadata lock has been acquired. A version mismatch causes a flush of the obsolete routine from the cache and statement reprepare. Incompatible changes: 1) ER_LOCK_DEADLOCK is reported for a transaction trying to access a procedure/function that is locked by a DDL operation in another connection. 2) Procedure/function DDL operations are now prohibited in LOCK TABLES mode as exclusive locks must be taken all at once and LOCK TABLES provides no way to specifiy procedures/functions to be locked. Test cases have been added to sp-lock.test and rpl_sp.test. Work on this bug has very much been a team effort and this patch includes and is based on contributions from Davi Arnaut, Dmitry Lenev, Magne Mæhre and Konstantin Osipov. mysql-test/r/ps_ddl.result: Update results (Bug#30977). mysql-test/r/ps_ddl1.result: Update results (Bug#30977). mysql-test/r/sp-error.result: Update results (Bug#30977). mysql-test/r/sp-lock.result: Update results (Bug#30977). mysql-test/suite/rpl/r/rpl_sp.result: Update results (Bug#30977). mysql-test/suite/rpl/t/rpl_sp.test: Add a test case for Bug#30977. mysql-test/t/ps_ddl.test: Update comments. We no longer re-prepare a prepared statement when a stored procedure used in top-level CALL is changed. mysql-test/t/ps_ddl1.test: Modifying stored procedure p1 no longer invalidates prepared statement "call p1" -- we can re-use the prepared statement without invalidation. mysql-test/t/sp-error.test: Use a constant for an error value. mysql-test/t/sp-lock.test: Add test coverage for Bug#30977. sql/lock.cc: Implement lock_routine_name() - a way to acquire an exclusive metadata lock (ex- name-lock) on stored procedure/function. sql/sp.cc: Change semantics of sp_cache_routine() -- now it has an option to make sure that the routine that is cached is up to date (has the latest sp cache version). Add sp_cache_invalidate() to sp_drop_routine(), where it was missing (a bug!). Acquire metadata locks for SP DDL (ALTER/CREATE/DROP). This is the core of the fix for Bug#30977. Since caching and cache invalidation scheme was changed, make sure we don't invalidate the SP cache in the middle of a stored routine execution. At the same time, make sure we don't access stale data due to lack of invalidation. For that, change ALTER FUNCTION/PROCEDURE to not use the cache, and SHOW PROCEDURE CODE/SHOW CREATE PROCEDURE/FUNCTION to always read an up to date version of the routine from the cache. sql/sp.h: Add a helper wrapper around sp_cache_routine(). sql/sp_cache.cc: Implement new sp_cache_version() and sp_cache_flush_obsolete(). Now we flush stale routines individually, rather than all at once. sql/sp_cache.h: Update signatures of sp_cache_version() and sp_cache_flush_obsolete(). sql/sp_head.cc: Add a default initialization of sp_head::m_sp_cache_version. Remove a redundant sp_head::create(). sql/sp_head.h: Add m_sp_cache_version to sp_head class - we now keep track of every routine in the stored procedure cache, rather than of the entire cache. sql/sql_base.cc: Implement prelocking for stored routines. Validate stored routines after they were locked. Flush obsolete routines upon next access, one by one, not all at once (Bug#41804). Style fixes. sql/sql_class.h: Rename a Open_table_context method. sql/sql_parse.cc: Make sure stored procedures DDL commits the active transaction (issues an implicit commit before and after). Remove sp_head::create(), a pure redundancy. Move the semantical check during alter routine inside sp_update_routine() code in order to: - avoid using SP cache during update, it may be obsolete. - speed up and simplify the update procedure. Remove sp_cache_flush_obsolete() calls, we no longer flush the entire cache, ever, stale routines are flushed before next use, one at a time. sql/sql_prepare.cc: Move routine metadata validation to open_and_process_routine(). Fix Bug#49972 (don't swap flags at reprepare). Reset Sroutine_hash_entries in reinit_stmt_before_use(). Remove SP cache invalidation, it's now done by open_tables(). sql/sql_show.cc: Fix a warning: remove an unused label. sql/sql_table.cc: Reset mdl_request.ticket for tickets acquired for routines inlined through a view, in CHECK TABLE statement, to satisfy an MDL assert. sql/sql_update.cc: Move the cleanup of "translation items" to close_tables_for_reopen(), since it's needed in all cases when we back off, not just the back-off in multi-update. This fixes a bug when the server would crash on attempt to back off when opening tables for a statement that uses information_schema tables.
| | * | | | | | | | | | | | | A prerequisite patch for the fix for Bug#46224Konstantin Osipov2009-12-221-0/+1
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Introduce a notion of a sentinel to MDL_context. A sentinel is a ticket that separates all tickets in the context into two groups: before and after it. Currently we can have (and need) only one designated sentinel -- it separates all locks taken by LOCK TABLE or HANDLER statement, which must survive COMMIT and ROLLBACK and all other locks, which must be released at COMMIT or ROLLBACK. The tricky part is maintaining the sentinel up to date when someone release its corresponding ticket. This can happen, e.g. if someone issues DROP TABLE under LOCK TABLES (generally, see all calls to release_all_locks_for_name()). MDL_context::release_ticket() is modified to take care of it. ****** A fix and a test case for Bug#46224 "HANDLER statements within a transaction might lead to deadlocks". An attempt to mix HANDLER SQL statements, which are transaction- agnostic, an open multi-statement transaction, and DDL against the involved tables (in a concurrent connection) could lead to a deadlock. The deadlock would occur when HANDLER OPEN or HANDLER READ would have to wait on a conflicting metadata lock. If the connection that issued HANDLER statement also had other metadata locks (say, acquired in scope of a transaction), a classical deadlock situation of mutual wait could occur. Incompatible change: entering LOCK TABLES mode automatically closes all open HANDLERs in the current connection. Incompatible change: previously an attempt to wait on a lock in a connection that has an open HANDLER statement could wait indefinitely/deadlock. After this patch, an error ER_LOCK_DEADLOCK is produced. The idea of the fix is to merge thd->handler_mdl_context with the main mdl_context of the connection, used for transactional locks. This makes deadlock detection possible, since all waits with locks are "visible" and available to analysis in a single MDL context of the connection. Since HANDLER locks and transactional locks have a different life cycle -- HANDLERs are explicitly open and closed, and so are HANDLER locks, explicitly acquired and released, whereas transactional locks "accumulate" till the end of a transaction and are released only with COMMIT, ROLLBACK and ROLLBACK TO SAVEPOINT, a concept of "sentinel" was introduced to MDL_context. All locks, HANDLER and others, reside in the same linked list. However, a selected element of the list separates locks with different life cycle. HANDLER locks always reside at the end of the list, after the sentinel. Transactional locks are prepended to the beginning of the list, before the sentinel. Thus, ROLLBACK, COMMIT or ROLLBACK TO SAVEPOINT, only release those locks that reside before the sentinel. HANDLER locks must be released explicitly as part of HANDLER CLOSE statement, or an implicit close. The same approach with sentinel is also employed for LOCK TABLES locks. Since HANDLER and LOCK TABLES statement has never worked together, the implementation is made simple and only maintains one sentinel, which is used either for HANDLER locks, or for LOCK TABLES locks. mysql-test/include/handler.inc: Add test coverage for Bug#46224 "HANDLER statements within a transaction might lead to deadlocks". Extended HANDLER coverage to cover a mix of HANDLER, transactions and DDL statements. mysql-test/r/handler_innodb.result: Update results (Bug#46224). mysql-test/r/handler_myisam.result: Update results (Bug#46224). sql/lock.cc: Remove thd->some_tables_deleted, it's never used. sql/log_event.cc: No need to check for thd->locked_tables_mode, it's done inside release_transactional_locks(). sql/mdl.cc: Implement the concept of HANDLER and LOCK TABLES "sentinel". Implement a method to clone an acquired ticket. Do not return tickets beyond the sentinel when acquiring locks, create a copy. Remove methods to merge and backup MDL_context, they are now not used (Hurra!). This opens a path to a proper constructor and destructor of class MDL_context (to be done in a separate patch). Modify find_ticket() to provide information about where the ticket position is with regard to the sentinel. sql/mdl.h: Add declarations necessary for the implementation of the concept of "sentinel", a dedicated ticket separating transactional and non-transactional locks. sql/mysql_priv.h: Add mark_tmp_table_for_reuse() declaration, a function to "close" a single session (temporary) table. sql/sql_base.cc: Remove thd->some_tables_deleted. Modify deadlock-prevention asserts and deadlock detection heuristics to take into account that from now on HANDLER locks reside in the same locking context. Add broadcast_refresh() to mysql_notify_thread_having_shared_lock(): this is necessary for the case when a thread having a shared lock is asleep in tdc_wait_for_old_versions(). This situation is only possible with HANDLER t1 OPEN; FLUSH TABLE (since all over code paths that lead to tdc_wait_for_old_versions() always have an empty MDL_context). Previously the server would simply deadlock in this situation. sql/sql_class.cc: Remove now unused member "THD::some_tables_deleted". Move mysql_ha_cleanup() a few lines above in THD::cleanup() to make sure that all handlers are closed when it's time to destroy the MDL_context of this connection. Remove handler_mdl_context and handler_tables. sql/sql_class.h: Remove THD::handler_tables, THD::handler_mdl_context, THD::some_tables_deleted. sql/sql_handler.cc: Remove thd->handler_tables. Remove thd->handler_mdl_context. Rewrite mysql_ha_open() to have no special provision for MERGE tables, now that we don't have to manipulate with thd->handler_tables it's easy to do. Remove dead code. Fix a bug in mysql_ha_flush() when we would always flush a temporary HANDLER when mysql_ha_flush() is called (actually mysql_ha_flush() never needs to flush temporary tables). sql/sql_insert.cc: Update a comment, no more thd->some_tables_deleted. sql/sql_parse.cc: Implement an incompatible change: entering LOCK TABLES closes active HANDLERs, if any. Now that we have a sentinel, we don't need to check for thd->locked_tables_mode when releasing metadata locks in COMMIT/ROLLBACK. sql/sql_plist.h: Add new (now necessary) methods to the list class. sql/sql_prepare.cc: Make sure we don't release HANDLER locks when rollback to a savepoint, set to not keep locks taken at PREPARE. sql/sql_servers.cc: Update to a new signature of MDL_context::release_all_locks(). sql/sql_table.cc: Remove thd->some_tables_deleted. sql/transaction.cc: Add comments. Make sure rollback to (MDL) savepoint works under LOCK TABLES and with HANDLER tables.
| | * | | | | | | | | | | | | Merge next-mr -> next-4284.Konstantin Osipov2009-12-151-0/+2
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| | * \ \ \ \ \ \ \ \ \ \ \ \ \ Merge next-mr -> next-4284.Konstantin Osipov2009-12-151-0/+11
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| | * \ \ \ \ \ \ \ \ \ \ \ \ \ \ Merge next-mr -> next-4284.Konstantin Osipov2009-12-151-1/+2
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| | * | | | | | | | | | | | | | | | Backport of revno: 2617.71.1Jon Olav Hauglid2009-12-101-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bug#42546 Backup: RESTORE fails, thinking it finds an existing table The problem occured when a MDL locking conflict happened for a non-existent table between a CREATE and a INSERT statement. The code for CREATE interpreted this lock conflict to mean that the table existed, which meant that the statement failed when it should not have. The problem could occur for CREATE TABLE, CREATE TABLE LIKE and ALTER TABLE RENAME. This patch fixes the problem for CREATE TABLE and CREATE TABLE LIKE. It is based on code backported from the mysql-6.1-fk tree written by Dmitry Lenev. CREATE now uses normal open_and_lock_tables() code to acquire exclusive locks. This means that for the test case in the bug description, CREATE will wait until INSERT completes so that it can get the exclusive lock. This resolves the reported bug. The patch also prohibits CREATE TABLE and CREATE TABLE LIKE under LOCK TABLES. Note that this is an incompatible change and must be reflected in the documentation. Affected test cases have been updated. mdl_sync.test contains tests for CREATE TABLE and CREATE TABLE LIKE. Fixing the issue for ALTER TABLE RENAME is beyond the scope of this patch. ALTER TABLE cannot be prohibited from working under LOCK TABLES as this could seriously impact customers and a proper fix would require a significant rewrite.
| | * | | | | | | | | | | | | | | | Backport of:Konstantin Osipov2009-12-091-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------ revno: 2617.68.7 committer: Dmitry Lenev <dlenev@mysql.com> branch nick: mysql-next-bg46044 timestamp: Thu 2009-08-27 10:22:17 +0400 message: Fix for bug #46044 "MDL deadlock on LOCK TABLE + CREATE TABLE HIGH_PRIORITY FOR UPDATE". Deadlock occured when during execution of query to I_S we tried to open a table or its .FRM in order to get information about it and had to wait because we have encountered exclusive metadata lock on this table held by a DDL operation from another connection which in its turn waited for some resource currently owned by connection executing this I_S query. For example, this might have happened if one under LOCK TABLES executed I_S query targeted to particular table (which was not among locked) and also concurrently tried to create this table using CREATE TABLE SELECT which had to wait for one of tables locked by the first connection. Another situation in which deadlock might have occured is when I_S query, which was executed as part of transaction, tried to get information about table which just has been dropped by concurrent DROP TABLES executed under LOCK TABLES and this DROP TABLES for its completion also had to wait transaction from the first connection. This problem stemmed from the fact that opening of tables/.FRMs for I_S filling is happening outside of connection's main MDL_context so code which tries to detect deadlocks due to conflicting metadata locks doesn't work in this case. Indeed, this led to deadlocks when during I_S filling we tried to wait for conflicting metadata lock to go away, while its owner was waiting for some resource held by connection executing I_S query. This patch solves this problem by avoiding waiting in such situation. Instead we skip this table and produce warning that information about it was omitted from I_S due to concurrent DDL operation. We still wait for conflicting metadata lock to go away when it is known that deadlock is not possible (i.e. when connection executing I_S query does not hold any metadata or table-level locks). Basically, we apply our standard deadlock avoidance technique for metadata locks to the process of filling of I_S tables but replace ER_LOCK_DEADLOCK error with a warning. Note that this change is supposed to be safe for 'mysqldump' since the only its mode which is affected by this change is --single-transaction mode is not safe in the presence of concurrent DDL anyway (and this fact is documented). Other modes are unaffected because they either use SHOW TABLES/SELECT * FROM I_S.TABLE_NAMES which do not take any metadata locks in the process of I_S table filling and thus cannot skip tables or execute I_S queries for tables which were previously locked by LOCK TABLES (or in the presence of global read lock) which excludes possibility of encountering conflicting metadata lock. mysql-test/r/mdl_sync.result: Added test for bug #46044 "MDL deadlock on LOCK TABLE + CREATE TABLE HIGH_PRIORITY FOR UPDATE". mysql-test/t/mdl_sync.test: Added test for bug #46044 "MDL deadlock on LOCK TABLE + CREATE TABLE HIGH_PRIORITY FOR UPDATE". sql/mysql_priv.h: Added a new flag for open_table() call which allows it to fail with an error in cases when conflicting metadata lock is discovered instead of waiting until this lock goes away. sql/share/errmsg-utf8.txt: Added error/warning message to be generated in cases when information about table is omitted from I_S since there is conflicting metadata lock on the table. sql/share/errmsg.txt: Added error/warning message to be generated in cases when information about table is omitted from I_S since there is conflicting metadata lock on the table. sql/sql_base.cc: Added a new flag for open_table() call which allows it to fail with an error in cases when conflicting metadata lock is discovered instead of waiting until this lock goes away. sql/sql_show.cc: When we are opening a table (or just .FRM) in order to fill I_S with information about this table and encounter conflicting metadata lock waiting for this lock to go away can lead to a deadlock in some situations (under LOCK TABLES, within transaction, etc.). To avoid these deadlocks we detect such situations and don't do waiting. Instead, we skip table for which we have conflicting metadata lock, thus omitting information about it from I_S table, and produce an appropriate warning.
| | * | | | | | | | | | | | | | | | Backport of:Konstantin Osipov2009-12-091-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ---------------------------------------------------------- revno: 2617.69.25 committer: Konstantin Osipov <kostja@sun.com> branch nick: 5.4-42546 timestamp: Fri 2009-08-14 23:52:00 +0400 message: A cleanup in open_tables() and lock_tables(): change return type of these functions to bool from int, to follow convention in the rest of the code. (Part of WL#4284 review fixes). sql/mysql_priv.h: Change return type of open_talbes() and lock_tables() from int to bool. sql/sql_base.cc: Change return type of open_tables() and lock_tables() from int to bool. sql/sql_handler.cc: Use bool now that open_tables() returns bool.
| | * | | | | | | | | | | | | | | | Backport of:Konstantin Osipov2009-12-081-3/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ---------------------------------------------------------- revno: 2617.69.24 committer: Konstantin Osipov <kostja@sun.com> branch nick: 5.4-42546 timestamp: Fri 2009-08-14 19:22:05 +0400 message: A pre-requisite for a fix for Bug#42546 "Backup: RESTORE fails, thinking it finds an existing table" Back-port from WL 148 "Foreign keys" feature tree a patch that introduced Prelocking_strategy class -- a way to parameterize open_tables() behaviour, implemented by Dmitry Lenev. (Part of WL#4284). sql/sql_base.cc: Implement different prelocking strategies. Use an instance of prelocking_strategy in open_tables(). sql/sql_class.h: Add declarations for class Prelocking_strategy. sql/sql_lex.h: Add a helper method to access last table of the global table list (lex->query_tables). sql/sql_parse.cc: Use a special prelocking strategy when locking tables for LOCK TABLES. sql/sql_table.cc: Use normal open_and_lock_tables_derived() in ALTER TABLE. sql/sql_yacc.yy: Modify the grammar to not pollute the global table list with tables that should not be opened.
| | * | | | | | | | | | | | | | | | Backport of:Konstantin Osipov2009-12-081-5/+3
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| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ---------------------------------------------------------- revno: 2617.69.20 committer: Konstantin Osipov <kostja@sun.com> branch nick: 5.4-4284-1-assert timestamp: Thu 2009-08-13 18:29:55 +0400 message: WL#4284 "Transactional DDL locking" A review fix. Since WL#4284 implementation separated MDL_request and MDL_ticket, MDL_request becamse a utility object necessary only to get a ticket. Store it by-value in TABLE_LIST with the intent to merge MDL_request::key with table_list->table_name and table_list->db in future. Change the MDL subsystem to not require MDL_requests to stay around till close_thread_tables(). Remove the list of requests from the MDL context. Requests for shared metadata locks acquired in open_tables() are only used as a list in recover_from_failed_open_table_attempt(), which calls mdl_context.wait_for_locks() for this list. To keep such list for recover_from_failed_open_table_attempt(), introduce a context class (Open_table_context), that collects all requests. A lot of minor cleanups and simplications that became possible with this change. sql/event_db_repository.cc: Remove alloc_mdl_requests(). Now MDL_request instance is a member of TABLE_LIST, and init_one_table() initializes it. sql/ha_ndbcluster_binlog.cc: Remove now unnecessary declaration and initialization of binlog_mdl_request. sql/lock.cc: No need to allocate MDL requests in lock_table_names() now. sql/log.cc: Use init_one_table() method, remove alloc_mdl_requests(), which is now unnecessary. sql/log_event.cc: No need to allocate mdl_request separately now. Use init_one_table() method. sql/log_event_old.cc: Update to the new signature of close_tables_for_reopen(). sql/mdl.cc: Update try_acquire_exclusive_lock() to be more easy to use. Function lock_table_name_if_not_cached() has been removed. Make acquire_shared_lock() signature consistent with try_acquire_exclusive_lock() signature. Remove methods that are no longer used. Update comments. sql/mdl.h: Implement an assignment operator that doesn't copy MDL_key (MDL_key::operator= is private and should remain private). This is a hack to work-around assignment of TABLE_LIST by value in several places. Such assignments violate encapsulation, since only perform a shallow copy. In most cases these assignments are a hack on their own. sql/mysql_priv.h: Update signatures of close_thread_tables() and close_tables_for_reopen(). sql/sp.cc: Allocate TABLE_LIST in thd->mem_root. Use init_one_table(). sql/sp_head.cc: Use init_one_table(). Remove thd->locked_tables_root, it's no longer needed. sql/sql_acl.cc: Use init_mdl_requests() and init_one_table(). sql/sql_base.cc: Update to new signatures of try_acquire_shared_lock() and try_acquire_exclusive_lock(). Remove lock_table_name_if_not_cached(). Fix a bug in open_ltable() that would not return ER_LOCK_DEADLOCK in case of a failed lock_tables() and a multi-statement transaction. Fix a bug in open_and_lock_tables_derived() that would not return ER_LOCK_DEADLOCK in case of a multi-statement transaction and a failure of lock_tables(). Move assignment of enum_open_table_action to a method of Open_table_context, a new class that maintains information for backoff actions. Minor rearrangements of the code. Remove alloc_mdl_requests() in functions that work with system tables: instead the patch ensures that callers always initialize TABLE_LIST argument. sql/sql_class.cc: THD::locked_tables_root is no more. sql/sql_class.h: THD::locked_tables_root is no more. Add a declaration for Open_table_context class. sql/sql_delete.cc: Update to use the simplified MDL API. sql/sql_handler.cc: TABLE_LIST::mdl_request is stored by-value now. Ensure that mdl_request.ticket is NULL for every request that is passed into MDL, to satisfy MDL asserts. @ sql/sql_help.cc Function open_system_tables_for_read() no longer initializes mdl_requests. Move TABLE_LIST::mdl_request initialization closer to TABLE_LIST initialization. sql/sql_help.cc: Function open_system_tables_for_read() no longer initializes mdl_requests. Move TABLE_LIST::mdl_request initialization closer to TABLE_LIST initialization. sql/sql_insert.cc: Remove assignment by-value of TABLE_LIST in TABLEOP_HOOKS. We can't carry over a granted MDL ticket from one table list to another. sql/sql_parse.cc: Change alloc_mdl_requests() -> init_mdl_requests(). @todo We can remove init_mdl_requests() altogether in some places: all places that call add_table_to_list() already have mdl requests initialized. sql/sql_plugin.cc: Use init_one_table(). THD::locked_tables_root is no more. sql/sql_servers.cc: Use init_one_table(). sql/sql_show.cc: Update acquire_high_priority_shared_lock() to use TABLE_LIST::mdl_request rather than allocate an own. Fix get_trigger_table_impl() to use init_one_table(), check for out of memory, follow the coding style. sql/sql_table.cc: Update to work with TABLE_LIST::mdl_request by-value. Remove lock_table_name_if_not_cached(). The code that used to delegate to it is quite simple and concise without it now. sql/sql_udf.cc: Use init_one_table(). sql/sql_update.cc: Update to use the new signature of close_tables_for_reopen(). sql/table.cc: Move re-setting of mdl_requests for prepared statements and stored procedures from close_thread_tables() to reinit_stmt_before_use(). Change alloc_mdl_requests() to init_mdl_requests(). init_mdl_requests() is a hack that can't be deleted until we don't have a list-aware TABLE_LIST constructor. Hopefully its use will be minimal sql/table.h: Change alloc_mdl_requests() to init_mdl_requests() TABLE_LIST::mdl_request is stored by value. sql/tztime.cc: We no longer initialize mdl requests in open_system_tables_for*() functions. Move this initialization closer to initialization of the rest of TABLE_LIST members. storage/myisammrg/ha_myisammrg.cc: Simplify mdl_request initialization.
| | * | | | | | | | | | | | | | | | Backport of:Konstantin Osipov2009-12-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------ revno: 2617.65.6 committer: Dmitry Lenev <dlenev@mysql.com> branch nick: mysql-azalea-bg39674 timestamp: Sat 2009-07-25 00:28:43 +0400 message: Fix for bug #39674 "On shutdown mdl_destroy() called before plugin_shutdown()". Attempt to shutdown PBXT engine plugin led to assertion failure caused by using already destroyed mutex in metadata locking subsystem. This problem stemmed from the fact that we MDL subsystem and table definition cache were deinitialized before plugin shutdown while PBXT plugin during its shutdown process accessed tables and therefore expected them to be in working shape. This patch solves this problem by moving deinitialization of these two subsystems after plugins are shut down. No test case is provided since such test case would require using PBXT or other plugin which accesses tables during its shutdown process. sql/mysql_priv.h: Introduced table_def_start_shutdown() function which informs table definition cache that shutdown process has been started so it has to keep number of TABLE and TABLE_SHARE objects minimal in order to reduce number of references to pluggable engines. sql/mysqld.cc: Destroy table definition cache and meta-data locking subsystem after shutting down plugins. This allows plugins to work with tables during their shutdown. Since table definition cache hold references to storage engine plugins we have to remove unused tables from it before shutting down plugins and keep number of these references minimal during the process (by immediately removing tables opened during this process from the table definition cache). sql/sql_base.cc: Introduced table_def_start_shutdown() function which informs table definition cache that shutdown process has been started so it has to keep number of TABLE and TABLE_SHARE objects minimal in order to reduce number of references to pluggable engines. This allows to smoothly shutdown such plugins without completely prohibiting access to tables/table definition cache while shutting down other plugins.
| | * | | | | | | | | | | | | | | | Backport of revno ## 2617.31.1, 2617.31.3, 2617.31.4, 2617.31.5,Konstantin Osipov2009-12-051-1/+1
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| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 2617.31.12, 2617.31.15, 2617.31.15, 2617.31.16, 2617.43.1 - initial changeset that introduced the fix for Bug#989 and follow up fixes for all test suite failures introduced in the initial changeset. ------------------------------------------------------------ revno: 2617.31.1 committer: Davi Arnaut <Davi.Arnaut@Sun.COM> branch nick: 4284-6.0 timestamp: Fri 2009-03-06 19:17:00 -0300 message: Bug#989: If DROP TABLE while there's an active transaction, wrong binlog order WL#4284: Transactional DDL locking Currently the MySQL server does not keep metadata locks on schema objects for the duration of a transaction, thus failing to guarantee the integrity of the schema objects being used during the transaction and to protect then from concurrent DDL operations. This also poses a problem for replication as a DDL operation might be replicated even thought there are active transactions using the object being modified. The solution is to defer the release of metadata locks until a active transaction is either committed or rolled back. This prevents other statements from modifying the table for the entire duration of the transaction. This provides commitment ordering for guaranteeing serializability across multiple transactions. - Incompatible change: If MySQL's metadata locking system encounters a lock conflict, the usual schema is to use the try and back-off technique to avoid deadlocks -- this schema consists in releasing all locks and trying to acquire them all in one go. But in a transactional context this algorithm can't be utilized as its not possible to release locks acquired during the course of the transaction without breaking the transaction commitments. To avoid deadlocks in this case, the ER_LOCK_DEADLOCK will be returned if a lock conflict is encountered during a transaction. Let's consider an example: A transaction has two statements that modify table t1, then table t2, and then commits. The first statement of the transaction will acquire a shared metadata lock on table t1, and it will be kept utill COMMIT to ensure serializability. At the moment when the second statement attempts to acquire a shared metadata lock on t2, a concurrent ALTER or DROP statement might have locked t2 exclusively. The prescription of the current locking protocol is that the acquirer of the shared lock backs off -- gives up all his current locks and retries. This implies that the entire multi-statement transaction has to be rolled back. - Incompatible change: FLUSH commands such as FLUSH PRIVILEGES and FLUSH TABLES WITH READ LOCK won't cause locked tables to be implicitly unlocked anymore. mysql-test/extra/binlog_tests/drop_table.test: Add test case for Bug#989. mysql-test/extra/binlog_tests/mix_innodb_myisam_binlog.test: Fix test case to reflect the fact that transactions now hold metadata locks for the duration of a transaction. mysql-test/include/mix1.inc: Fix test case to reflect the fact that transactions now hold metadata locks for the duration of a transaction. mysql-test/include/mix2.inc: Fix test case to reflect the fact that transactions now hold metadata locks for the duration of a transaction. mysql-test/r/flush_block_commit.result: Update test case result (WL#4284). mysql-test/r/flush_block_commit_notembedded.result: Update test case result (WL#4284). mysql-test/r/innodb.result: Update test case result (WL#4284). mysql-test/r/innodb_mysql.result: Update test case result (WL#4284). mysql-test/r/lock.result: Add test case result for an effect of WL#4284/Bug#989 (all locks should be released when a connection terminates). mysql-test/r/mix2_myisam.result: Update test case result (effects of WL#4284/Bug#989). mysql-test/r/not_embedded_server.result: Update test case result (effects of WL#4284/Bug#989). Add a test case for interaction of WL#4284 and FLUSH PRIVILEGES. mysql-test/r/partition_innodb_semi_consistent.result: Update test case result (effects of WL#4284/Bug#989). mysql-test/r/partition_sync.result: Temporarily disable the test case for Bug#43867, which will be fixed by a subsequent backport. mysql-test/r/ps.result: Add a test case for effect of PREPARE on transactional locks: we take a savepoint at beginning of PREAPRE and release it at the end. Thus PREPARE does not accumulate metadata locks (Bug#989/WL#4284). mysql-test/r/read_only_innodb.result: Update test case result (effects of WL#4284/Bug#989). mysql-test/suite/binlog/r/binlog_row_drop_tbl.result: Add a test case result (WL#4284/Bug#989). mysql-test/suite/binlog/r/binlog_row_mix_innodb_myisam.result: Update test case result (effects of WL#4284/Bug#989). mysql-test/suite/binlog/r/binlog_stm_drop_tbl.result: Add a test case result (WL#4284/Bug#989). mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result: Update test case result (effects of WL#4284/Bug#989). mysql-test/suite/binlog/r/binlog_unsafe.result: A side effect of Bug#989 -- slightly different table map ids. mysql-test/suite/binlog/t/binlog_row_drop_tbl.test: Add a test case for WL#4284/Bug#989. mysql-test/suite/binlog/t/binlog_stm_drop_tbl.test: Add a test case for WL#4284/Bug#989. mysql-test/suite/binlog/t/binlog_stm_row.test: Update to the new state name. This is actually a follow up to another patch for WL#4284, that changes Locked thread state to Table lock. mysql-test/suite/ndb/r/ndb_index_ordered.result: Remove result for disabled part of the test case. mysql-test/suite/ndb/t/disabled.def: Temporarily disable a test case (Bug#45621). mysql-test/suite/ndb/t/ndb_index_ordered.test: Disable a part of a test case (needs update to reflect semantics of Bug#989). mysql-test/suite/rpl/t/disabled.def: Disable tests made meaningless by transactional metadata locking. mysql-test/suite/sys_vars/r/autocommit_func.result: Add a commit (Bug#989). mysql-test/suite/sys_vars/t/autocommit_func.test: Add a commit (Bug#989). mysql-test/t/flush_block_commit.test: Fix test case to reflect the fact that transactions now hold metadata locks for the duration of a transaction. mysql-test/t/flush_block_commit_notembedded.test: Fix test case to reflect the fact that transactions now hold metadata locks for the duration of a transaction. Add a test case for transaction-scope locks and the global read lock (Bug#989/WL#4284). mysql-test/t/innodb.test: Fix test case to reflect the fact that transactions now hold metadata locks for the duration of a transaction (effects of Bug#989/WL#4284). mysql-test/t/lock.test: Add a test case for Bug#989/WL#4284. mysql-test/t/not_embedded_server.test: Add a test case for Bug#989/WL#4284. mysql-test/t/partition_innodb_semi_consistent.test: Replace TRUNCATE with DELETE, to not issue an implicit commit of a transaction, and not depend on metadata locks. mysql-test/t/partition_sync.test: Temporarily disable the test case for Bug#43867, which needs a fix to be backported from 6.0. mysql-test/t/ps.test: Add a test case for semantics of PREPARE and transaction-scope locks: metadata locks on tables used in PREPARE are enclosed into a temporary savepoint, taken at the beginning of PREPARE, and released at the end. Thus PREPARE does not effect what locks a transaction owns. mysql-test/t/read_only_innodb.test: Fix test case to reflect the fact that transactions now hold metadata locks for the duration of a transaction (Bug#989/WL#4284). Wait for the read_only statement to actually flush tables before sending other concurrent statements that depend on its state. mysql-test/t/xa.test: Fix test case to reflect the fact that transactions now hold metadata locks for the duration of a transaction (Bug#989/WL#4284). sql/ha_ndbcluster_binlog.cc: Backport bits of changes of ha_ndbcluster_binlog.cc from 6.0, to fix the failing binlog test suite with WL#4284. WL#4284 implementation does not work with 5.1 implementation of ndbcluster binlog index. sql/log_event.cc: Release metadata locks after issuing a commit. sql/mdl.cc: Style changes (WL#4284). sql/mysql_priv.h: Rename parameter to match the name used in the definition (WL#4284). sql/rpl_injector.cc: Release metadata locks on commit (WL#4284). sql/rpl_rli.cc: Remove assert made meaningless, metadata locks are released at the end of the transaction. sql/set_var.cc: Close tables and release locks if autocommit mode is set. sql/slave.cc: Release metadata locks after a rollback. sql/sql_acl.cc: Don't implicitly unlock locked tables. Issue a implicit commit at the end and unlock tables. sql/sql_base.cc: Defer the release of metadata locks when closing tables if not required to. Issue a deadlock error if the locking protocol requires that a transaction re-acquire its locks. Release metadata locks when closing tables for reopen. sql/sql_class.cc: Release metadata locks if the thread is killed. sql/sql_parse.cc: Release metadata locks after implicitly committing a active transaction, or after explicit commits or rollbacks. sql/sql_plugin.cc: Allocate MDL request on the stack as the use of the table is contained within the function. It will be removed from the context once close_thread_tables is called at the end of the function. sql/sql_prepare.cc: The problem is that the prepare phase of the CREATE TABLE statement takes a exclusive metadata lock lock and this can cause a self-deadlock the thread already holds a shared lock on the table being that should be created. The solution is to make the prepare phase take a shared metadata lock when preparing a CREATE TABLE statement. The execution of the statement will still acquire a exclusive lock, but won't cause any problem as it issues a implicit commit. After some discussions with stakeholders it has been decided that metadata locks acquired during a PREPARE statement must be released once the statement is prepared even if it is prepared within a multi statement transaction. sql/sql_servers.cc: Don't implicitly unlock locked tables. Issue a implicit commit at the end and unlock tables. sql/sql_table.cc: Close table and release metadata locks after a admin operation. sql/table.h: The problem is that the prepare phase of the CREATE TABLE statement takes a exclusive metadata lock lock and this can cause a self-deadlock the thread already holds a shared lock on the table being that should be created. The solution is to make the prepare phase take a shared metadata lock when preparing a CREATE TABLE statement. The execution of the statement will still acquire a exclusive lock, but won't cause any problem as it issues a implicit commit. sql/transaction.cc: Release metadata locks after the implicitly committed due to a new transaction being started. Also, release metadata locks acquired after a savepoint if the transaction is rolled back to the save point. The problem is that in some cases transaction-long metadata locks could be released before the transaction was committed. This could happen when a active transaction was ended by a "START TRANSACTION" or "BEGIN" statement, in which case the metadata locks would be released before the actual commit of the active transaction. The solution is to defer the release of metadata locks to after the transaction has been implicitly committed. No test case is provided as the effort to provide one is too disproportional to the size of the fix.
| | * | | | | | | | | | | | | | | | Backport of:Konstantin Osipov2009-12-031-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------ revno: 2630.22.3 committer: Davi Arnaut <Davi.Arnaut@Sun.COM> branch nick: 4284-6.0 timestamp: Thu 2008-08-07 22:33:43 -0300 message: WL#4284: Transactional DDL locking Make transaction management more modular through a new interface. The overall objective of this change is to provide groundwork for the design of transactional DDL locking by cleaning up the transaction high level API to better distinguish operations implicit and explicit, and single statement transaction from operations on the normal transaction. Having a a high-level interface for transaction management provides a better base for implementing transactional concepts that are not always tied to storage engines and also makes it easier to interect with other higher level modules of the server. client/Makefile.am: Add new file to the build. libmysqld/CMakeLists.txt: Add new file to the build. libmysqld/Makefile.am: Add new file to the build. sql/CMakeLists.txt: Add new file to the build. sql/Makefile.am: Add new file to the build. sql/handler.cc: Remove multiplexer commit or rollback function. Most callers already have enough information to decided whether to rollback or commit. Having plain and well named functions makes it easier to read and understand code. sql/handler.h: Remove wrapper function as the low level transaction functions shouldn't be called directly anymore. sql/log_event.cc: Rename transaction management functions to the new names. sql/log_event_old.cc: Rename transaction management functions to the new names. sql/mysql_priv.h: Remove obsolete functions for implicit and explicit commit. sql/rpl_injector.cc: Rename transaction management functions to the new names. sql/rpl_rli.cc: Rename transaction management functions to the new names. sql/set_var.cc: Rename transaction management functions to the new names. sql/slave.cc: Rename transaction management functions to the new names. sql/sql_base.cc: Rename transaction management functions to the new names. sql/sql_class.cc: Rename transaction management functions to the new names. sql/sql_delete.cc: Rename transaction management functions to the new names. sql/sql_do.cc: Rename transaction management functions to the new names. sql/sql_insert.cc: Rename transaction management functions to the new names. sql/sql_parse.cc: Rename transaction management functions to the new names. sql/sql_partition.cc: Rename transaction management functions to the new names. sql/sql_table.cc: Rename transaction management functions to the new names. sql/transaction.cc: Implement wrapper functions to differentiate operations on the single statement transaction from the ones operating on the normal transaction. sql/transaction.h: Export new functions for dealing with transaction commands.
| | * | | | | | | | | | | | | | | | Backport of:Konstantin Osipov2009-12-031-1/+1
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| | * | | | | | | | | | | | | | | | Merge next-mr -> next-4284Konstantin Osipov2009-12-031-14/+37
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| | * | | | | | | | | | | | | | | | | Backport of:Konstantin Osipov2009-12-031-3/+0
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| | | | | | | | | | | | | | | | | | | | | | | | | | | ---------------------------------------------------------- revno: 2630.4.38 committer: Konstantin Osipov <konstantin@mysql.com> branch nick: mysql-6.0-4144 timestamp: Wed 2008-06-25 22:07:06 +0400 message: WL#4144 - Lock MERGE engine children. Committing a version of the patch merged with WL#3726 on behalf of Ingo. Step #1: Move locking from parent to children. MERGE children are now left in the query list of tables after inserted there in open_tables(). So they are locked by lock_tables() as all other tables are. The MERGE parent does not store locks any more. It appears in a MYSQL_LOCK with zero lock data. This is kind of a "dummy" lock. All other lock handling is also done directly on the children. To protect against parent or child modifications during LOCK TABLES, the children are detached after every statement and attached before every statement, even under LOCK TABLES. The children table list is removed from the query list of tables on every detach and on close of the parent. Step #2: Move MERGE specific functionality from SQL layer into table handler. Functionality moved from SQL layer (mainly sql_base.cc) to the table handler (ha_myisammrg.cc). Unnecessary code is removed from the SQL layer. Step #3: Moved all MERGE specific members from TABLE to ha_myisammrg. Moved members from TABLE to ha_myisammrg. Renamed some mebers. Fixed comments. Step #4: Valgrind and coverage testing Valgrind did not uncover new problems. Added purecov comments. Added a new test for DATA/INDEX DIRECTORY options. Changed handling of ::reset() for non-attached children. Fixed the merge-big test. Step #5: Fixed crashes detected during review Changed detection when to attach/detach. Added new tests. Backport also the fix for Bug#44040 "MySQL allows creating a MERGE table upon VIEWs but crashes when using it" include/my_base.h: WL#4144 - Lock MERGE engine children Added HA_EXTRA_ADD_CHILDREN_LIST and HA_EXTRA_IS_ATTACHED_CHILDREN for MERGE table support mysql-test/r/merge.result: WL#4144 - Lock MERGE engine children Fixed test result. mysql-test/t/disabled.def: Enable merge.test, which now is working again (WL#4144). mysql-test/t/merge-big.test: Fix the messages for wait_condition (merge with WL#3726). mysql-test/t/merge.test: WL#4144 - Lock MERGE engine children Fixed one test to meet coding standards for tests (upper case keywords, engine names as in SHOW ENGINES). Fixed error codes. Added a test for DATA/INDEX DIRECTORY. mysys/thr_lock.c: WL#4144 - Lock MERGE engine children Added purecov comments. sql/ha_partition.cc: WL#4144 - Lock MERGE engine children Added MERGE specific extra operations to ha_partition::extra(). Extended comments. Changed function comment to doxygen style. Fixed nomenclature: 'parameter' -> 'operation'. sql/mysql_priv.h: WL#4144 - Lock MERGE engine children Removed declarations for removed functions. sql/sql_base.cc: WL#4144 - Lock MERGE engine children Leave the children in the query list of tables after open_tables(). Set proper back links (prev_global). Attach MERGE children before and detach them after every statement. Even under LOCK TABLES. Remove children from the query list when they are detached. Remove lock forwarding from children to parent. Moved MERGE specific functions to ha_myisammrg.cc. Added purecov comments. Backport the fix for Bug#44040 "MySQL allows creating a MERGE table upon VIEWs but crashes when using it" sql/sql_table.cc: WL#4144 - Lock MERGE engine children Changed detection of MERGE tables. sql/table.cc: WL#4144 - Lock MERGE engine children Moved is_children_attached() method from TABLE to ha_myisammrg. sql/table.h: WL#4144 - Lock MERGE engine children Moved all MERGE specific members from TABLE to ha_myisammrg. storage/myisammrg/ha_myisammrg.cc: WL#4144 - Lock MERGE engine children Set proper back links in the child list (prev_global). Added a function for removal of the child list from the query list. Remove children from the query list when the parent is closed. Make parent lock handling a dummy (zero locks). Moved MERGE specific functionality from SQL layer to here. Moved all MERGE specific members from TABLE to ha_myisammrg. Renamed children list pointers. Added initialization and free for the children list mem_root. Fixed comments. Added purecov comments. storage/myisammrg/ha_myisammrg.h: WL#4144 - Lock MERGE engine children Added method add_children_list(). Moved all MERGE specific members from TABLE to ha_myisammrg. Renamed children list pointers. Added a mem_root for the children list. storage/myisammrg/myrg_extra.c: WL#4144 - Lock MERGE engine children Changed handling of ::reset() for non-attached children.