mariadb

Commit Graph

Author	SHA1	Message	Date
Michael Widenius	e6b0be38f9	Bug fix for lp:732124 union + limit returns wrong result mysql-test/r/union.result: Added test for lp:732124 mysql-test/t/union.test: Added test for lp:732124 sql/sp_rcontext.cc: Updated function definition for ::send_data() sql/sp_rcontext.h: Updated function definition for ::send_data() sql/sql_analyse.cc: Test if send_data() returned an error sql/sql_class.cc: Updated function definition for ::send_data() sql/sql_class.h: Changed select_result::send_data(List<Item> &items) to return -1 in case of duplicate row that should not be counted as part of LIMIT sql/sql_cursor.cc: Check if send_data returned error sql/sql_delete.cc: Updated function definition for ::send_data() sql/sql_insert.cc: Updated function definition for ::send_data() sql/sql_select.cc: Don't count rows which send_data() tells you to ignore sql/sql_union.cc: Inform caller that the row should be ignored. This is the real bug fix for lp:732124 sql/sql_update.cc: Updated function definition for ::send_data()	15 years ago
Michael Widenius	e63b5546c5	Implementation of MWL#172: Add support for prepared statements to HANDLER READ It includes speed optimizations for HANDLER READ by caching as much as possible in HANDLER OPEN Other things: - Added mysqld option --disable-thr-alarm to be able to benchmark things without thr_alarm - Changed 'Locked' state to 'System lock' and 'Table lock' (these where used in the code but never shown to end user) - Better error message if mysql_install_db.sh fails - Moved handler function prototypes to sql_handler.h - Remove not anymore used 'thd->locked' member include/thr_alarm.h: Added my_disable_thr_alarm include/thr_lock.h: Add new member to THR_LOCK_DATA to remember original lock type state. This is needed as thr_unlock() resets type to TL_UNLOCK. mysql-test/include/check_no_concurrent_insert.inc: Locked -> Table lock mysql-test/include/handler.inc: Locked -> Table lock mysql-test/r/handler_innodb.result: Updated results for new tests mysql-test/r/handler_myisam.result: Updated results for new tests mysql-test/r/sp-threads.result: Locked -> Table lock mysql-test/suite/binlog/t/binlog_stm_row.test: Locked -> Table lock mysql-test/suite/funcs_1/datadict/processlist_val.inc: Locked -> Table lock mysql-test/suite/pbxt/t/lock_multi.test: Locked -> Table lock mysql-test/suite/sys_vars/r/concurrent_insert_func.result: Locked -> Table lock mysql-test/suite/sys_vars/t/concurrent_insert_func.test: Locked -> Table lock mysql-test/suite/sys_vars/t/delayed_insert_limit_func.test: Locked -> Table lock mysql-test/suite/sys_vars/t/query_cache_wlock_invalidate_func.test: Locked -> Table lock mysql-test/suite/sys_vars/t/sql_low_priority_updates_func.test: Locked -> Table lock mysql-test/t/insert_notembedded.test: Locked -> Table lock mysql-test/t/lock_multi.test: Locked -> Table lock mysql-test/t/merge-big.test: Locked -> Table lock mysql-test/t/multi_update.test: Locked -> Table lock mysql-test/t/query_cache_28249.test: Locked -> Table lock mysql-test/t/sp_notembedded.test: Locked -> Table lock mysql-test/t/sp_sync.test: Locked -> Table lock mysql-test/t/status.test: Locked -> Table lock mysql-test/t/trigger_notembedded.test: Locked -> Table lock mysys/thr_alarm.c: Added option to disable thr_alarm mysys/thr_lock.c: Detect loops scripts/mysql_install_db.sh: Give better error message if something goes wrong sql/Makefile.am: Added sql_handler.h sql/lock.cc: Split functions to allow one to cache value if store_lock() (for HANDLER functions). - Split mysql_lock_tables() into two functions, where first one allocates MYSQL_LOCK and other other one uses it. - Made get_lock_data() an external function. - Added argument to mysql_unlock_tables() to not free sql_lock. - Added argument to reset_lock_data() to reset lock structure to initial state (as after get_lock_data()) sql/mysql_priv.h: Moved handler function prototypes to sql_handler.h Added new lock functions. sql/mysqld.cc: Added --thread-alarm startup option sql/net_serv.cc: Don't call vio_blocking() if not needed sql/sql_base.cc: include sql_handler.h sql/sql_class.cc: include sql_handler.h Remove not anymore used 'thd->locked' member sql/sql_class.h: Remove not anymore used 'thd->locked' member sql/sql_db.cc: include sql_handler.h sql/sql_delete.cc: include sql_handler.h sql/sql_handler.cc: Rewrote all code to use SQL_HANDLER instead of TABLE_LIST (original interface) Rewrote mysql_ha_open() to cache all things from TABLE_LIST and items for field list, where etc. In mysql_ha_open() also cache MYSQL_LOCK structure from get_lock_data(). Split functions into smaller sub functions (needed to be able to implement mysql_ha_read_prepare()) Added mysql_ha_read_prepare() to allow one to prepare HANDLER READ. sql/sql_handler.h: Interface to sql_handler.cc sql/sql_parse.cc: include sql_handler.h sql/sql_prepare.cc: Added mysql_test_handler_read(), prepare for HANDLER READ sql/sql_rename.cc: include sql_handler.h sql/sql_show.cc: Removed usage of thd->locked sql/sql_table.cc: include sql_handler.h sql/sql_trigger.cc: include sql_handler.h	15 years ago
Jon Olav Hauglid	7a64d43ad0	Bug #51099 Assertion in mysql_multi_delete_prepare() This assert was triggered if DELETE was done on a view that referenced another view which in turn (directly or indirectly) referenced more than one table. Delete from a view referencing more than one table (a join view) is not supported and is supposed to give ER_VIEW_DELETE_MERGE_VIEW error. Before this error was reported from the multi table delete code, an assert verified that the view from the DELETE statement had more than one underlying table. However, this assert did not take into account that the view could refer to another view which in turn referenced the actual tables. This patch fixes the problem by adjusting the assert to take this possibility into account. This problem was only noticeable on debug builds of the server. On release builds, ER_VIEW_DELETE_MERGE_VIEW was correctly reported. Test case added to delete.test.	15 years ago
Jon Olav Hauglid	c4a18b6af3	Bug #51099 Assertion in mysql_multi_delete_prepare() This assert was triggered if DELETE was done on a view that referenced another view which in turn (directly or indirectly) referenced more than one table. Delete from a view referencing more than one table (a join view) is not supported and is supposed to give ER_VIEW_DELETE_MERGE_VIEW error. Before this error was reported from the multi table delete code, an assert verified that the view from the DELETE statement had more than one underlying table. However, this assert did not take into account that the view could refer to another view which in turn referenced the actual tables. This patch fixes the problem by adjusting the assert to take this possibility into account. This problem was only noticeable on debug builds of the server. On release builds, ER_VIEW_DELETE_MERGE_VIEW was correctly reported. Test case added to delete.test.	15 years ago
Michael Widenius	5ce4825b63	Fix usage of mysqld option --new, --old, --safe and --skip_new to not disable things that are proven stable or enable things that are not usefull. sql/field.cc: Remove feature of 'new_mode' that was never implemtented in a newer MySQL version. sql/item_cmpfunc.cc: Boyer more is stable; Don't have to be protected by --skip-new anymore sql/mysqld.cc: Don't disable some proven stable functions with --skip-new sql/records.cc: Don't disable record caching with --safe-mode anymore sql/sql_delete.cc: Do fast truncate even if --skip-new or --safe is used sql/sql_parse.cc: Use always mysql_optimizer() for optimizer (instead of mysql_recreate_table() in case of --safe or --skip-new) sql/sql_select.cc: Don't disable 'only_eq_ref_tables' if --safe is used. sql/sql_yacc.yy: Removed not meaningfull test of --old	15 years ago
unknown	18ad3bdc2f	MWL#89: Cost-based choice between Materialization and IN->EXISTS transformation Fixes for multiple problems/bugs/test failures that resulted from moving subquery optimization from the execution phase to the optimization phase.	15 years ago
Alexander Nozdrin	928140d90e	Rename select_send::abort() to select_send::abort_result_set() to be more descriptive.	15 years ago
Alexander Nozdrin	8909586f16	Rename select_send::abort() to select_send::abort_result_set() to be more descriptive.	15 years ago
Jon Olav Hauglid	85e5ce0ba0	Bug #54734 assert in Diagnostics_area::set_ok_status This assert checks that the server does not try to send OK to the client if there has been some error during processing. This is done to make sure that the error is in fact sent to the client. The problem was that view errors during processing of WHERE conditions in UPDATE statements where not detected by the update code. It therefore tried to send OK to the client, triggering the assert. The bug was only noticeable in debug builds. This patch fixes the problem by making sure that the update code checks for errors during condition processing and acts accordingly.	15 years ago
Jon Olav Hauglid	4b2378a148	Bug #54734 assert in Diagnostics_area::set_ok_status This assert checks that the server does not try to send OK to the client if there has been some error during processing. This is done to make sure that the error is in fact sent to the client. The problem was that view errors during processing of WHERE conditions in UPDATE statements where not detected by the update code. It therefore tried to send OK to the client, triggering the assert. The bug was only noticeable in debug builds. This patch fixes the problem by making sure that the update code checks for errors during condition processing and acts accordingly.	15 years ago
Igor Babaev	452860dfde	Fixed bug #604503 . If the expression for a virtual column of table contained datetime comparison then the execution of the second query that used this virtual column caused a crash. It happened because the execution of the first query that used this virtual column inserted a cached item into the expression tree. The cached tree was allocated in the statement memory while the expression tree was allocated in the table memory. Now the cached items that are inserted into expressions for virtual columns with datetime comparisons are always allocated in the same mem_root as the expressions for virtual columns. So now the inserted cached items are valid for any queries that use these virtual columns.	15 years ago
Michael Widenius	e9166ca152	Fix for LP#588251: doStartTableScan() result not checked. The issue was that we didn't always check result of ha_rnd_init() which caused a problem for handlers that returned an error in this code. - Changed prototype of ha_rnd_init() to ensure that we get a compile warning if result is not checked. - Added ha_rnd_init_with_error() that prints error on failure. - Checked all usage of ha_rnd_init() and ensure we generate an error message on failures. - Changed init_read_record() to return 1 on failure. sql/create_options.cc: Fixed wrong printf sql/event_db_repository.cc: Check result from init_read_record() sql/events.cc: Check result from init_read_record() sql/filesort.cc: Check result from ha_rnd_init() sql/ha_partition.cc: Check result from ha_rnd_init() sql/ha_partition.h: Fixed compiler warning sql/handler.cc: Added ha_rnd_init_with_error() Check result from ha_rnd_init() sql/handler.h: Added ha_rnd_init_with_error() Changed prototype of ha_rnd_init() to ensure that we get a compile warning if result is not checked sql/item_subselect.cc: Check result from ha_rnd_init() sql/log.cc: Check result from ha_rnd_init() sql/log_event.cc: Check result from ha_rnd_init() sql/log_event_old.cc: Check result from ha_rnd_init() sql/mysql_priv.h: init_read_record() now returns error code on failure sql/opt_range.cc: Check result from ha_rnd_init() sql/records.cc: init_read_record() now returns error code on failure Check result from ha_rnd_init() sql/sql_acl.cc: Check result from init_read_record() sql/sql_cursor.cc: Print error if ha_rnd_init() fails sql/sql_delete.cc: Check result from init_read_record() sql/sql_help.cc: Check result from init_read_record() sql/sql_plugin.cc: Check result from init_read_record() sql/sql_select.cc: Check result from ha_rnd_init() Print error if ha_rnd_init() fails. sql/sql_servers.cc: Check result from init_read_record() sql/sql_table.cc: Check result from init_read_record() sql/sql_udf.cc: Check result from init_read_record() sql/sql_update.cc: Check result from init_read_record() storage/example/ha_example.cc: Don't return error on rnd_init() storage/ibmdb2i/ha_ibmdb2i.cc: Removed not relevant comment	15 years ago
Igor Babaev	b95bd9f5e2	Fixed bug #601164 . The functions mysql_delete and mysql_update lacked calls of updated_virtual_fields(). This caused wrong results for some DELETEs/UPDATEs. Added test cases for this bug.	16 years ago
Gleb Shchepa	ef4c0f68d1	Bug #30584 : delete with order by and limit clauses does not use limit efficiently Bug #36569: UPDATE ... WHERE ... ORDER BY... always does a filesort even if not required Also two bugs reported after QA review (before the commit of bugs above to public trees, no documentation needed): Bug #53737: Performance regressions after applying patch for bug 36569 Bug #53742: UPDATEs have no effect after applying patch for bug 36569 Execution of single-table UPDATE and DELETE statements did not use the same optimizer as was used in the compilation of SELECT statements. Instead, it had an optimizer of its own that did not take into account that you can omit sorting by retrieving rows using an index. Extra optimization has been added: when applicable, single-table UPDATE/DELETE statements use an existing index instead of filesort. A corresponding SELECT query would do the former. Also handling of the DESC ordering expression has been added when reverse index scan is applicable. From now on most single table UPDATE and DELETE statements show the same disk access patterns as the corresponding SELECT query. We verify this by comparing the result of SHOW STATUS LIKE 'Sort% Currently the get_index_for_order function a) checks quick select index (if any) for compatibility with the ORDER expression list or b) chooses the cheapest available compatible index, but only if the index scan is cheaper than filesort. Second way is implemented by the new test_if_cheaper_ordering function (extracted part the test_if_skip_sort_order()). mysql-test/r/log_state.result: Updated result for optimized query, bug #36569. mysql-test/r/single_delete_update.result: Test case for bug #30584, bug #36569 and bug #53742. mysql-test/r/update.result: Updated result for optimized query, bug #30584. Note: "Handler_read_last 1" omitted, see bug 52312: lost Handler_read_last status variable. mysql-test/t/single_delete_update.test: Test case for bug #30584, bug #36569 and bug #53742. sql/opt_range.cc: Bug #30584, bug #36569: UPDATE/DELETE ... WHERE ... ORDER BY... always does a filesort even if not required * get_index_for_order() has been rewritten entirely and moved to sql_select.cc New QUICK_RANGE_SELECT::make_reverse method has been added. sql/opt_range.h: Bug #30584, bug #36569: UPDATE/DELETE ... WHERE ... ORDER BY... always does a filesort even if not required * get_index_for_order() has been rewritten entirely and moved to sql_select.cc New functions: * QUICK_SELECT_I::make_reverse() * SQL_SELECT::set_quick() sql/records.cc: Bug #30584, bug #36569: UPDATE/DELETE ... WHERE ... ORDER BY... always does a filesort even if not required * init_read_record_idx() has been modified to allow reverse index scan New functions: * rr_index_last() * rr_index_desc() sql/records.h: Bug #30584, bug #36569: UPDATE/DELETE ... WHERE ... ORDER BY... always does a filesort even if not required init_read_record_idx() has been modified to allow reverse index scan sql/sql_delete.cc: Bug #30584, bug #36569: UPDATE/DELETE ... WHERE ... ORDER BY... always does a filesort even if not required mysql_delete: an optimization has been added to skip unnecessary sorting with ORDER BY clause where select result ordering is acceptable. sql/sql_select.cc: Bug #30584, bug #36569, bug #53737, bug #53742: UPDATE/DELETE ... WHERE ... ORDER BY... always does a filesort even if not required The const_expression_in_where function has been modified to accept both Item and Field pointers. New functions: * get_index_for_order() * test_if_cheaper_ordering() has been extracted from test_if_skip_sort_order() to share with get_index_for_order() * simple_remove_const() sql/sql_select.h: Bug #30584, bug #36569: UPDATE/DELETE ... WHERE ... ORDER BY... always does a filesort even if not required New functions: * test_if_cheaper_ordering() * simple_remove_const() * get_index_for_order() sql/sql_update.cc: Bug #30584, bug #36569: UPDATE/DELETE ... WHERE ... ORDER BY... always does a filesort even if not required mysql_update: an optimization has been added to skip unnecessary sorting with ORDER BY clause where a select result ordering is acceptable. sql/table.cc: Bug #30584, bug #36569: UPDATE/DELETE ... WHERE ... ORDER BY... always does a filesort even if not required New functions: * TABLE::update_const_key_parts() * is_simple_order() sql/table.h: Bug #30584, bug #36569: UPDATE/DELETE ... WHERE ... ORDER BY... always does a filesort even if not required New functions: * TABLE::update_const_key_parts() * is_simple_order()	16 years ago
Gleb Shchepa	da4d23277f	Bug #30584 : delete with order by and limit clauses does not use limit efficiently Bug #36569: UPDATE ... WHERE ... ORDER BY... always does a filesort even if not required Also two bugs reported after QA review (before the commit of bugs above to public trees, no documentation needed): Bug #53737: Performance regressions after applying patch for bug 36569 Bug #53742: UPDATEs have no effect after applying patch for bug 36569 Execution of single-table UPDATE and DELETE statements did not use the same optimizer as was used in the compilation of SELECT statements. Instead, it had an optimizer of its own that did not take into account that you can omit sorting by retrieving rows using an index. Extra optimization has been added: when applicable, single-table UPDATE/DELETE statements use an existing index instead of filesort. A corresponding SELECT query would do the former. Also handling of the DESC ordering expression has been added when reverse index scan is applicable. From now on most single table UPDATE and DELETE statements show the same disk access patterns as the corresponding SELECT query. We verify this by comparing the result of SHOW STATUS LIKE 'Sort% Currently the get_index_for_order function a) checks quick select index (if any) for compatibility with the ORDER expression list or b) chooses the cheapest available compatible index, but only if the index scan is cheaper than filesort. Second way is implemented by the new test_if_cheaper_ordering function (extracted part the test_if_skip_sort_order()).	16 years ago
Davi Arnaut	0f9ddfa9d8	Bug#42733: Type-punning warnings when compiling MySQL -- strict aliasing violations. One somewhat major source of strict-aliasing violations and related warnings is the SQL_LIST structure. For example, consider its member function `link_in_list` which takes a pointer to pointer of type T (any type) as a pointer to pointer to unsigned char. Dereferencing this pointer, which is done to reset the next field, violates strict-aliasing rules and might cause problems for surrounding code that uses the next field of the object being added to the list. The solution is to use templates to parametrize the SQL_LIST structure in order to deference the pointers with compatible types. As a side bonus, it becomes possible to remove quite a few casts related to acessing data members of SQL_LIST. sql/handler.h: Use the appropriate template type argument. sql/item.cc: Remove now-unnecessary cast. sql/item_subselect.cc: Remove now-unnecessary casts. sql/item_sum.cc: Use the appropriate template type argument. Remove now-unnecessary cast. sql/mysql_priv.h: Move SQL_LIST structure to sql_list.h Use the appropriate template type argument. sql/sp.cc: Remove now-unnecessary casts. sql/sql_delete.cc: Use the appropriate template type argument. Remove now-unnecessary casts. sql/sql_derived.cc: Remove now-unnecessary casts. sql/sql_lex.cc: Remove now-unnecessary casts. sql/sql_lex.h: SQL_LIST now takes a template type argument which must match the type of the elements of the list. Use forward declaration when the type is not available, it is used in pointers anyway. sql/sql_list.h: Rename SQL_LIST to SQL_I_List. The template parameter is the type of object that is stored in the list. sql/sql_olap.cc: Remove now-unnecessary casts. sql/sql_parse.cc: Remove now-unnecessary casts. sql/sql_prepare.cc: Remove now-unnecessary casts. sql/sql_select.cc: Remove now-unnecessary casts. sql/sql_show.cc: Remove now-unnecessary casts. sql/sql_table.cc: Remove now-unnecessary casts. sql/sql_trigger.cc: Remove now-unnecessary casts. sql/sql_union.cc: Remove now-unnecessary casts. sql/sql_update.cc: Remove now-unnecessary casts. sql/sql_view.cc: Remove now-unnecessary casts. sql/sql_yacc.yy: Remove now-unnecessary casts. storage/myisammrg/ha_myisammrg.cc: Remove now-unnecessary casts.	16 years ago
Davi Arnaut	53b8829682	Bug#42733: Type-punning warnings when compiling MySQL -- strict aliasing violations. One somewhat major source of strict-aliasing violations and related warnings is the SQL_LIST structure. For example, consider its member function `link_in_list` which takes a pointer to pointer of type T (any type) as a pointer to pointer to unsigned char. Dereferencing this pointer, which is done to reset the next field, violates strict-aliasing rules and might cause problems for surrounding code that uses the next field of the object being added to the list. The solution is to use templates to parametrize the SQL_LIST structure in order to deference the pointers with compatible types. As a side bonus, it becomes possible to remove quite a few casts related to acessing data members of SQL_LIST.	16 years ago
Davi Arnaut	1164841167	Backport: Remove unused and ancient files, functions, and facilities. client/mysql.cc: Remove unused functions. client/sql_string.cc: Remove unused functions. include/my_pthread.h: Remove unused prototype. mysys/my_pthread.c: Remove unused function. sql/lock.cc: Remove unused function. sql/lock.h: Remove unused and duplicated prototypes. sql/sql_class.h: Removed unused variables. sql/sql_const.h: Remove unused defines. sql/sql_priv.h: Remove unused defines. sql/sql_string.cc: Remove unused prototype. sql/thr_malloc.cc: Remove unused function. sql/thr_malloc.h: Remove unused prototype. storage/myisam/CMakeLists.txt: Remove obsolete fulltext file. storage/myisam/Makefile.am: Remove obsolete files (were already commented out). storage/myisam/ft_eval.c: Remove obsolete fulltext file. storage/myisam/ft_eval.h: Remove obsolete fulltext file. storage/myisam/ft_stem.c: Remove obsolete fulltext file. storage/myisam/ft_test1.c: Remove obsolete fulltext file. storage/myisam/ft_test1.h: Remove obsolete fulltext file.	16 years ago
Davi Arnaut	570c6cc87a	Backport: Remove unused and ancient files, functions, and facilities.	16 years ago
Igor Babaev	709a0a1310	MWL#106: Backport optimizations for derived tables and views. The main consolidated patch.	16 years ago
Igor Babaev	d120c5b562	Changed the fixes for the following bugs: Bug #39022: completed Bug #39653: reverted as invalid Bug #45640: ameliorated, simplified, optimized Bug #48483: completed Bug #49324: improved Bug #51242/52336: reverted, applied a real fix.	16 years ago
Davi Arnaut	4f18083b08	Bug#42643: InnoDB does not support replication of TRUNCATE TABLE The problem was that TRUNCATE TABLE didn't take a exclusive lock on a table if it resorted to truncating via delete of all rows in the table. Specifically for InnoDB tables, this could break proper isolation as InnoDB ends up aborting some granted locks when truncating a table. The solution is to take a exclusive metadata lock before TRUNCATE TABLE can proceed. This guarantees that no other transaction is using the table. Incompatible change: Truncate via delete no longer fails if sql_safe_updates is activated (this was a undocumented side effect). libmysqld/CMakeLists.txt: Add new files to the build list. libmysqld/Makefile.am: Add new files to the build list. mysql-test/extra/binlog_tests/binlog_truncate.test: Add test case for Bug#42643 mysql-test/include/mix1.inc: Update test case as TRUNCATE TABLE now grabs a exclusive lock. Ensure that TRUNCATE waits for granted locks on the table. mysql-test/suite/binlog/t/binlog_truncate_innodb.test: As with other data modifying statements, TRUNCATE is still not possible in a transaction with isolation level READ COMMITTED or READ UNCOMMITED. It would be possible to implement so, but it is not worth the effort. mysql-test/suite/binlog/t/binlog_truncate_myisam.test: Test under different binlog formats. mysql-test/suite/binlog/t/disabled.def: Re-enable test case. mysql-test/t/innodb_bug38231.test: Truncate no longer works with row-level locks. mysql-test/t/mdl_sync.test: Ensure that a acquired lock is not given up due to a conflict. mysql-test/t/partition_innodb_semi_consistent.test: End transaction as to release metadata locks. mysql-test/t/truncate.test: A metadata lock is now taken before the object is verified. sql/CMakeLists.txt: Add new files to the build list. sql/Makefile.am: Add new files to the build list. sql/datadict.cc: Introduce a new file specific for data dictionary operations. sql/datadict.h: Add header file. sql/sql_base.cc: Rename data dictionary function. sql/sql_bitmap.h: Include dependency. sql/sql_delete.cc: Move away from relying on mysql_delete() to delete all rows of a table. Thus, move any bits related to truncate to sql_truncate.cc sql/sql_delete.h: Remove parameter. sql/sql_parse.cc: Add protection against the global read lock -- a intention exclusive lock can be acquired in the truncate path. sql/sql_show.cc: Add sync point for testing scenarios where a pending flush is ignored. sql/sql_truncate.cc: Acquire a shared metadata lock before accessing table metadata. Upgrade the lock to a exclusive one if the table can be re-created. Rework binlog rules to better reflect the requirements. sql/sql_yacc.yy: Set appropriate lock types for table to be truncated. sql/table.h: Move to data dictionary header.	16 years ago
Davi Arnaut	3c279d9a5a	Bug#42643: InnoDB does not support replication of TRUNCATE TABLE The problem was that TRUNCATE TABLE didn't take a exclusive lock on a table if it resorted to truncating via delete of all rows in the table. Specifically for InnoDB tables, this could break proper isolation as InnoDB ends up aborting some granted locks when truncating a table. The solution is to take a exclusive metadata lock before TRUNCATE TABLE can proceed. This guarantees that no other transaction is using the table. Incompatible change: Truncate via delete no longer fails if sql_safe_updates is activated (this was a undocumented side effect).	16 years ago
Gleb Shchepa	9cbb009b2e	Bug #53450 : Crash / assertion "virtual int ha_myisam::index_first(uchar)") at assert.c:81 Single-table DELETE crash/assertion similar to single-table UPDATE bug 14272. Same resolution as for the bug 14272: Don't run index scan when we should use quick select. This could cause failures because there are table handlers (like federated) that support quick select scanning but do not support index scanning. mysql-test/r/delete.result: Test case for bug #53450. mysql-test/t/delete.test: Test case for bug #53450. sql/sql_delete.cc: Bug #53450: Crash / assertion "virtual int ha_myisam::index_first(uchar)") at assert.c:81 The mysql_delete function has been modified to not to use init_read_record_idx instead of init_read_record for the quick select.	16 years ago
Gleb Shchepa	09b6efcc76	Bug #53450 : Crash / assertion "virtual int ha_myisam::index_first(uchar*)") at assert.c:81 Single-table DELETE crash/assertion similar to single-table UPDATE bug 14272. Same resolution as for the bug 14272: Don't run index scan when we should use quick select. This could cause failures because there are table handlers (like federated) that support quick select scanning but do not support index scanning.	16 years ago
Alexander Nozdrin	4333980a49	Patch for Bug#21818 (Return value of ROW_COUNT() is incorrect for ALTER TABLE, LOAD DATA). ROW_COUNT is now assigned according to the following rules: - In my_ok(): - for DML statements: to the number of affected rows; - for DDL statements: to 0. - In my_eof(): to -1 to indicate that there was a result set. We derive this semantics from the JDBC specification, where int java.sql.Statement.getUpdateCount() is defined to (sic) "return the current result as an update count; if the result is a ResultSet object or there are no more results, -1 is returned". - In my_error(): to -1 to be compatible with the MySQL C API and MySQL ODBC driver. - For SIGNAL statements: to 0 per WL#2110 specification. Zero is used since that's the "default" value of ROW_COUNT in the diagnostics area. sql/protocol.cc: Fix a typo. sql/sql_class.h: - Introduce THD::get_row_count_func() / THD::set_row_count_func(); - Remove the CF_HAS_ROW_COUNT define sql/sql_parse.cc: CF_HAS_ROW_COUNT was eliminated.	16 years ago
Alexander Nozdrin	7752ccec48	Patch for Bug#21818 (Return value of ROW_COUNT() is incorrect for ALTER TABLE, LOAD DATA). ROW_COUNT is now assigned according to the following rules: - In my_ok(): - for DML statements: to the number of affected rows; - for DDL statements: to 0. - In my_eof(): to -1 to indicate that there was a result set. We derive this semantics from the JDBC specification, where int java.sql.Statement.getUpdateCount() is defined to (sic) "return the current result as an update count; if the result is a ResultSet object or there are no more results, -1 is returned". - In my_error(): to -1 to be compatible with the MySQL C API and MySQL ODBC driver. - For SIGNAL statements: to 0 per WL#2110 specification. Zero is used since that's the "default" value of ROW_COUNT in the diagnostics area.	16 years ago
Staale Smedseng	330864fcda	Bug #49756 Rows_examined is always 0 in the slow query log for update statements Only SELECT statements report any examined rows in the slow log. Slow UPDATE, DELETE and INSERT statements report 0 rows examined, unless the statement has a condition including a SELECT substatement. This patch adds counting of examined rows for the UPDATE and DELETE statements. An INSERT ... VALUES statement will still not report any rows as examined. sql/sql_class.h: Added more docs for THD::examined_row_count. sql/sql_delete.cc: Add incrementing thd->examined_row_count. sql/sql_update.cc: Add incrementing thd->examined_row_count.	16 years ago
Staale Smedseng	44fe4c707b	Bug #49756 Rows_examined is always 0 in the slow query log for update statements Only SELECT statements report any examined rows in the slow log. Slow UPDATE, DELETE and INSERT statements report 0 rows examined, unless the statement has a condition including a SELECT substatement. This patch adds counting of examined rows for the UPDATE and DELETE statements. An INSERT ... VALUES statement will still not report any rows as examined.	16 years ago
Mats Kindahl	23d8586dbf	WL#5030: Split and remove mysql_priv.h 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	16 years ago
Mats Kindahl	e409d6f69c	WL#5030: Split and remove mysql_priv.h 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	16 years ago
Michael Widenius	77afc2be46	Fix for: Bug#44987 DELETE IGNORE and FK constraint - Now DELETE IGNORE skips over rows with a foreign key constraints (as it was supposed to do) mysql-test/r/foreign_key.result: Test case for Bug#44987 DELETE IGNORE and FK constraint mysql-test/t/foreign_key.test: Test case for Bug#44987 DELETE IGNORE and FK constraint sql/sql_delete.cc: Firx for Bug#44987 DELETE IGNORE and FK constraint Now DELETE IGNORE skips over rows with a foreign key constraints (as it was supposed to do) Bug fix inspired by: Moritz Mertinkat	16 years ago
Luis Soares	8713ccb969	BUG#51251: Wrong binlogging in case of TRUNCATE <temporary InnoDB table> Incremental commit based on previous patch. Addresses reviewer comments to move reseting of thd->current_stmt_binlog_row_based to after binlog_query takes place.	16 years ago
Luis Soares	ae7d5721cf	BUG#51251: Wrong binlogging in case of TRUNCATE <temporary InnoDB table> Incremental commit based on previous patch. Addresses reviewer comments to move reseting of thd->current_stmt_binlog_row_based to after binlog_query takes place.	16 years ago
Luis Soares	48d65a645e	BUG#51251: Wrong binlogging in case of TRUNCATE <temporary InnoDB table> For temporary tables that are created with an engine that does not provide the HTON_CAN_RECREATE, the truncate operation is performed resorting to the optimized handler::ha_delete_all_rows method. However, this means that the truncate will share execution path, from mysql_delete, with truncate on regular tables and other delete operations. As a consequence the truncate operation, for the temporary table is logged, even if in row mode because there is no distinction between this and the other delete operations at binlogging time. We fix this by checking if: (i) the binlog format, when the truncate operation was issued, is ROW; (ii) if the operation is a truncate; and (iii) if the table is a temporary table; before writing to the binary log. If all three conditions are met, we skip writing to the binlog. A side effect of this fix is that we limit the scope of setting and resetting the current_stmt_binlog_row_based. Now we just set and reset it inside mysql_delete in the boundaries of the handler::ha_write_row loop. This way we have access to thd->current_stmt_binlog_row_based real value inside mysql_delete. mysql-test/suite/binlog/r/binlog_row_mix_innodb_myisam.result: Updated result for spurious truncate table. mysql-test/suite/binlog/t/binlog_row_innodb_truncate.test: Test case. sql/sql_delete.cc: Added check in mysql_delete before writing the TRUNCATE statement to the binary log. Additionally, removed the set/reset of current_stmt_binlog_row_based so that it happens just in the boundaries of the handler::ha_write_row loop inside mysql_delete.	16 years ago
Luis Soares	1fe647a4ba	BUG#51251: Wrong binlogging in case of TRUNCATE <temporary InnoDB table> For temporary tables that are created with an engine that does not provide the HTON_CAN_RECREATE, the truncate operation is performed resorting to the optimized handler::ha_delete_all_rows method. However, this means that the truncate will share execution path, from mysql_delete, with truncate on regular tables and other delete operations. As a consequence the truncate operation, for the temporary table is logged, even if in row mode because there is no distinction between this and the other delete operations at binlogging time. We fix this by checking if: (i) the binlog format, when the truncate operation was issued, is ROW; (ii) if the operation is a truncate; and (iii) if the table is a temporary table; before writing to the binary log. If all three conditions are met, we skip writing to the binlog. A side effect of this fix is that we limit the scope of setting and resetting the current_stmt_binlog_row_based. Now we just set and reset it inside mysql_delete in the boundaries of the handler::ha_write_row loop. This way we have access to thd->current_stmt_binlog_row_based real value inside mysql_delete.	16 years ago
Jon Olav Hauglid	e60ef89317	Followup to Bug#45225 Locking: hang if drop table with no timeout 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.	16 years ago
Jon Olav Hauglid	dd42aab840	Followup to Bug#45225 Locking: hang if drop table with no timeout 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.	16 years ago
Jon Olav Hauglid	3d6a89e792	Bug #45225 Locking: hang if drop table with no timeout This patch introduces timeouts for metadata locks. The timeout is specified in seconds using the new dynamic system variable "lock_wait_timeout" which has both GLOBAL and SESSION scopes. Allowed values range from 1 to 31536000 seconds (= 1 year). The default value is 1 year. The new server parameter "lock-wait-timeout" can be used to set the default value parameter upon server startup. "lock_wait_timeout" applies to all statements that use metadata locks. These include DML and DDL operations on tables, views, stored procedures and stored functions. They also include LOCK TABLES, FLUSH TABLES WITH READ LOCK and HANDLER statements. The patch also changes thr_lock.c code (table data locks used by MyISAM and other simplistic engines) to use the same system variable. InnoDB row locks are unaffected. One exception to the handling of the "lock_wait_timeout" variable is delayed inserts. All delayed inserts are executed with a timeout of 1 year regardless of the setting for the global variable. As the connection issuing the delayed insert gets no notification of delayed insert timeouts, we want to avoid unnecessary timeouts. It's important to note that the timeout value is used for each lock acquired and that one statement can take more than one lock. A statement can therefore block for longer than the lock_wait_timeout value before reporting a timeout error. When lock timeout occurs, ER_LOCK_WAIT_TIMEOUT is reported. Test case added to lock_multi.test. include/my_pthread.h: Added macros for comparing two timespec structs. include/thr_lock.h: Introduced timeouts for thr_lock.c locks. mysql-test/r/mysqld--help-notwin.result: Updated result file with the new server variable. mysql-test/r/mysqld--help-win.result: Updated result file with the new server variable. mysql-test/suite/sys_vars/r/lock_wait_timeout_basic.result: Added basic test for the new server variable. mysql-test/suite/sys_vars/t/lock_wait_timeout_basic.test: Added basic test for the new server variable. mysys/thr_lock.c: Introduced timeouts for thr_lock.c locks. sql/mdl.cc: Introduced timeouts for metadata locks. sql/mdl.h: Introduced timeouts for metadata locks. sql/sql_base.cc: Introduced timeouts in tdc_wait_for_old_versions(). sql/sql_class.h: Added new server variable lock_wait_timeout. sql/sys_vars.cc: Added new server variable lock_wait_timeout.	16 years ago
Jon Olav Hauglid	5bb67f34b8	Bug #45225 Locking: hang if drop table with no timeout This patch introduces timeouts for metadata locks. The timeout is specified in seconds using the new dynamic system variable "lock_wait_timeout" which has both GLOBAL and SESSION scopes. Allowed values range from 1 to 31536000 seconds (= 1 year). The default value is 1 year. The new server parameter "lock-wait-timeout" can be used to set the default value parameter upon server startup. "lock_wait_timeout" applies to all statements that use metadata locks. These include DML and DDL operations on tables, views, stored procedures and stored functions. They also include LOCK TABLES, FLUSH TABLES WITH READ LOCK and HANDLER statements. The patch also changes thr_lock.c code (table data locks used by MyISAM and other simplistic engines) to use the same system variable. InnoDB row locks are unaffected. One exception to the handling of the "lock_wait_timeout" variable is delayed inserts. All delayed inserts are executed with a timeout of 1 year regardless of the setting for the global variable. As the connection issuing the delayed insert gets no notification of delayed insert timeouts, we want to avoid unnecessary timeouts. It's important to note that the timeout value is used for each lock acquired and that one statement can take more than one lock. A statement can therefore block for longer than the lock_wait_timeout value before reporting a timeout error. When lock timeout occurs, ER_LOCK_WAIT_TIMEOUT is reported. Test case added to lock_multi.test.	16 years ago
Michael Widenius	d77e3cde5f	When one does a drop table, the indexes are not flushed to disk before drop anymore (with MyISAM/Maria) myisam-recover options changed from OFF to 'DEFAULT' to get less change of data loss when using MyISAM. (The disadvantage is that changed MyISAM tables will be checked at access time; Use --myisam-recover=OFF for old behavior) Don't call extra(HA_EXTRA_FORCE_REOPEN) in ALTER TABLE if table is locked as this will mark table as crashed! Added assert to detect if we accidently would use MyISAM versioning in MySQL include/my_base.h: Mark NOT_USED as USED, as we now use this as a flag to not call extra() mysql-test/mysql-test-run.pl: Don't write all options when there is something wrong with the arguments mysql-test/r/sp-destruct.result: Add missing flush of mysql.proc (as the test copied live tables) mysql-test/r/variables.result: myisam-recover options changed to 'default' mysql-test/r/view.result: Don't show create time in result mysql-test/suite/maria/t/maria-recovery2-master.opt: Don't run test with myisam-recover (as this produces extra warnings during simulated death) mysql-test/t/sp-destruct.test: Add missing flush of mysql.proc (as the test copied live tables) mysql-test/t/view.test: Don't show create time in result sql/lock.cc: Added marker if table was deleted to argument list sql/mysql_priv.h: Added marker if table was deleted to argument list sql/mysqld.cc: myisam-recover options changed from OFF to 'DEFAULT' to get less change of data loss when using MyISAM Allow one to specify OFF as argument to myisam-recover (was default before but one couldn't specify it) sql/sql_base.cc: Mark if table is going to be deleted sql/sql_delete.cc: Mark if table is going to be deleted sql/sql_table.cc: Mark if table is going to be deleted Don't call extra(HA_EXTRA_FORCE_REOPEN) in ALTER TABLE if table is locked as this will mark table as crashed! sql/table.cc: Signal to handler if table is getting deleted as part of getting droped from table cache. sql/table.h: Added marker if table is going to be deleted. storage/maria/ha_maria.cc: Don't search for transaction handler if file is not transactional or outside of transaction (Fixed possible core dump) storage/maria/ma_blockrec.c: Don't write changed information if table is going to be deleted. storage/maria/ma_close.c: Don't write changed information if table is going to be deleted. storage/maria/ma_extra.c: Mark tables that are deleted as crased, to ensure good behavior on restart if we suddenly crash. storage/maria/ma_locking.c: Cleanup storage/maria/ma_recovery.c: We need trnman to be inited during redo phase (to be able to open tables checked with maria_chk) storage/maria/maria_def.h: Added marker if table is going to be deleted. storage/myisam/mi_close.c: Don't write changed information if table is going to be deleted. storage/myisam/mi_extra.c: Mark tables that are deleted as crased, to ensure good behavior on restart if we suddenly crash. storage/myisam/mi_open.c: Added assert to detect if we accidently would use MyISAM versioning in MySQL storage/myisam/myisamdef.h: Added marker if table is going to be deleted.	16 years ago
Dmitry Lenev	8018ec5adb	Fix for bug #50913 "Deadlock between open_and_lock_tables_derived 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.	16 years ago
Dmitry Lenev	c7e7a7d20c	Fix for bug #50913 "Deadlock between open_and_lock_tables_derived 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.	16 years ago
Konstantin Osipov	00dc9a6e70	Merge next-mr -> next-4284. 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	16 years ago
Konstantin Osipov	06e1a73af6	Merge next-mr -> next-4284. 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	16 years ago
Dmitry Lenev	eba5d30e67	Implement new type-of-operation-aware metadata locks. 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.	16 years ago
Dmitry Lenev	afd15c43a9	Implement new type-of-operation-aware metadata locks. 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.	16 years ago
He Zhenxing	2b16517522	Backport Bug#37148 to 5.1	16 years ago
He Zhenxing	6bf8c119fe	Backport Bug#37148 to 5.1	16 years ago
Dmitry Lenev	6ddd01c27a	Patch that changes 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. 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.	16 years ago

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924 Commits (a69da0c31e97109bba099022acdd393f92fa127f)