mariadb

Commit Graph

Author	SHA1	Message	Date
Sergey Petrunya	36be492dc0	Fix a compile error, and most likely a bug: jtb_table_no holds table number, not table->map.	15 years ago
Sergey Petrunya	0ce603ab5e	[No BUG#] Fixes for problems discovered when running mysql-trunk's subquery testsuite	15 years ago
Kent Boortz	44135d4725	Updated/added copyright headers	15 years ago
Kent Boortz	e5ce023f57	Updated/added copyright headers	15 years ago
Igor Babaev	37bac085da	Fixed LP bug #799499 . The following were missing in the patch for mwl106: - KEY_PART_INFO::fieldnr were not set for generated keys to access tmp tables storing the rows of materialized derived tables/views - TABLE_SHARE::column_bitmap_size was not set for tmp tables storing the rows of materialized derived tables/views. These could cause crashes or memory overwrite.	15 years ago
Sergey Petrunya	6adddca80e	Make semi-joins work with outer joins part #1 : - Make make_outerjoin_info() correctly process semi-join nests - Make make_join_select() attach conditions to the right places.	15 years ago
Jorgen Loland	5a0e7394a5	BUG#11882110: UPDATE REPORTS ER_KEY_NOT_FOUND IF TABLE IS UPDATED TWICE For multi update it is not allowed to update a column of a table if that table is accessed through multiple aliases and either 1) the updated column is used as partitioning key 2) the updated column is part of the primary key and the primary key is clustered This check is done in unsafe_key_update(). The bug was that for case 2), it was checked whether updated_column_number == table_share->primary_key However, the primary_key variable is the index number of the primary key, not a column number. Prior to this bugfix, the first column was wrongly believed to be the primary key. The columns covered by an index is found in table->key_info[idx_number]->key_part. The bugfix is to check if any of the columns in the keyparts of the primary key are updated. The user-visible effect is that for storage engines with clustered primary key (e.g. InnoDB but not MyISAM) queries like "UPDATE t1 AS A JOIN t2 AS B SET A.primkey=..." will now error with "ERROR HY000: Primary key/partition key update is not allowed since the table is updated both as 'A' and 'B'." instead of "ERROR 1032 (HY000): Can't find record in 't1_tb'" even if primkey is not the first column in the table. This was the intended behavior of bugfix 11764529. mysql-test/r/multi_update.result: Add test for bug#11882110 mysql-test/r/multi_update_innodb.result: Add test for bug#11882110 mysql-test/t/multi_update.test: Add test for bug#11882110 mysql-test/t/multi_update_innodb.test: Add test for bug#11882110 sql/sql_update.cc: unsafe_key_update() wrongly checked if the primary key index number was the same as updated column number. Now it is checked whether any of the columns making up the primary key is updated. sql/table.h: Fix comment on TABLE_SHARE::primary_key. Incorrect comment was introduced by an earlier merge conflict (as per dlenev)	15 years ago
Jorgen Loland	ebe94178d1	BUG#11882110: UPDATE REPORTS ER_KEY_NOT_FOUND IF TABLE IS UPDATED TWICE For multi update it is not allowed to update a column of a table if that table is accessed through multiple aliases and either 1) the updated column is used as partitioning key 2) the updated column is part of the primary key and the primary key is clustered This check is done in unsafe_key_update(). The bug was that for case 2), it was checked whether updated_column_number == table_share->primary_key However, the primary_key variable is the index number of the primary key, not a column number. Prior to this bugfix, the first column was wrongly believed to be the primary key. The columns covered by an index is found in table->key_info[idx_number]->key_part. The bugfix is to check if any of the columns in the keyparts of the primary key are updated. The user-visible effect is that for storage engines with clustered primary key (e.g. InnoDB but not MyISAM) queries like "UPDATE t1 AS A JOIN t2 AS B SET A.primkey=..." will now error with "ERROR HY000: Primary key/partition key update is not allowed since the table is updated both as 'A' and 'B'." instead of "ERROR 1032 (HY000): Can't find record in 't1_tb'" even if primkey is not the first column in the table. This was the intended behavior of bugfix 11764529.	15 years ago
Sergey Petrunya	77c4c4d8ea	post-merge fixes: get MWL#90 code to work with MWL#89's way of processing prepared statements: - conversion subquery_predicate -> TABLE_LIST is once per-statement - However, the code must take into account that materialized temptable is dropped and re-created on each execution (the tricky part is that at start of n-th EXECUTE we have TABLE_LIST object but not its TABLE object) - IN-equality is injected into WHERE on every execution.	15 years ago
Sergei Golubchik	7c459960ec	db_low_byte_first is gone	15 years ago
Sergei Golubchik	e343a2c134	small enhancement of the create table options feature: no unnecessary casting from void*, more type safety. typos fixed.	15 years ago
Sergey Petrunya	524e6aad73	MWL#90: Non-merged semi-joins - Take into account that grouping or aggregates decrease join output cardinality. (First code, can't make use of index statistics yet)	15 years ago
Sergei Golubchik	0accbd0364	lots of post-merge changes	15 years ago
Magnus Blåudd	1c5d585ba5	Bug#60111 storage type for table not saved in .frm (aka BUG#11766883) - fix review comments - Rewrite last usage of handler::get_tablespace_name to use table->s->tablespace directly - Remove(revert) the addition of default implementation for handler::get_tablespace_name - Add comments describing the new TABLE_SHARE members default_storage_media and tablespace - Fix usage of incorrect mask for column_format bits, i.e COLUMN_FORMAT_MASK	15 years ago
Magnus Blåudd	3d8d672450	Bug#60111 storage type for table not saved in .frm (aka BUG#11766883) - fix review comments - Rewrite last usage of handler::get_tablespace_name to use table->s->tablespace directly - Remove(revert) the addition of default implementation for handler::get_tablespace_name - Add comments describing the new TABLE_SHARE members default_storage_media and tablespace - Fix usage of incorrect mask for column_format bits, i.e COLUMN_FORMAT_MASK	15 years ago
Sergey Petrunya	792c67ff61	MWL#90: Address review feedback part #1	15 years ago
Magnus Blåudd	0be575b7c8	Bug#60111 storage type for table not saved in .frm - Add new "format section" in extra data segment with additional table and column properties. This was originally introduced in 5.1.20 based MySQL Cluster - Remove hardcoded STORAGE DISK for table and instead output the real storage format used. Keep both TABLESPACE and STORAGE inside same version guard. - Implement default version of handler::get_tablespace_name() since tablespace is now available in share and it's unnecessary for each handler to implement. (the function could actually be removed totally now). - Add test for combinations of TABLESPACE and STORAGE with CREATE TABLE and ALTER TABLE - Add test to show that 5.5 now can read a .frm file created by MySQL Cluster 7.0.22. Although it does not yet show the column level attributes, they are read.	15 years ago
Magnus Blåudd	6c85d65357	Bug#60111 storage type for table not saved in .frm - Add new "format section" in extra data segment with additional table and column properties. This was originally introduced in 5.1.20 based MySQL Cluster - Remove hardcoded STORAGE DISK for table and instead output the real storage format used. Keep both TABLESPACE and STORAGE inside same version guard. - Implement default version of handler::get_tablespace_name() since tablespace is now available in share and it's unnecessary for each handler to implement. (the function could actually be removed totally now). - Add test for combinations of TABLESPACE and STORAGE with CREATE TABLE and ALTER TABLE - Add test to show that 5.5 now can read a .frm file created by MySQL Cluster 7.0.22. Although it does not yet show the column level attributes, they are read.	15 years ago
Michael Widenius	ff3da0f963	Change TABLE->alias to String for less memory reallocation Changed some String.ptr() -> String.c_ptr() for String that are not guaranteed to end with \0 Removed some c_ptr() usage from parameters to functions that takes ptr & length Use preallocate buffers to avoid calling malloc() for most operations. sql/event_db_repository.cc: alias is now a String sql/event_scheduler.cc: c_ptr -> c_ptr_safe() to avoid warnings from valgrind. sql/events.cc: c_ptr -> c_ptr_safe() to avoid warnings from valgrind. c_ptr -> ptr() as function takes ptr & length sql/field.cc: alias is now a String sql/field.h: alias is now a String sql/ha_partition.cc: alias is now a String sql/handler.cc: alias is now a String ptr() -> c_ptr() as string is not guaranteed to be \0 terminated sql/item.cc: Store error parameter in separarte buffer to ensure correct error message sql/item_func.cc: ptr() -> c_ptr_safe() as string is not guaranteed to be \0 terminated sql/item_sum.h: Use my_strtod() instead of my_atof() to not have to make string \0 terminated sql/lock.cc: alias is now a String sql/log.cc: c_ptr() -> ptr() as function takes ptr & length sql/log_event.cc: c_ptr_quick() -> ptr() as we only want to get the pointer to String buffer sql/opt_range.cc: ptr() -> c_ptr() as string is not guaranteed to be \0 terminated sql/opt_table_elimination.cc: alias is now a String sql/set_var.cc: ptr() -> c_ptr() as string is not guaranteed to be \0 terminated c_ptr() -> c_ptr_safe() to avoid warnings from valgrind. c_ptr() -> ptr() as function takes ptr & length Simplify some code. sql/sp.cc: c_ptr() -> ptr() as function takes ptr & length sql/sp_rcontext.cc: alias is now a String sql/sql_base.cc: alias is now a String. Here we win a realloc() for most alias usage. sql/sql_class.cc: Use size descriptor for printf() to avoid accessing bytes outside of buffer sql/sql_insert.cc: Change allocation of TABLE as it's now contains a String _ptr() -> ptr() as function takes ptr & length sql/sql_load.cc: Use preallocate buffers to avoid calling malloc() for most operations. sql/sql_parse.cc: Use c_ptr_safe() to ensure string is \0 terminated. sql/sql_plugin.cc: c_ptr_quick() -> ptr() as function takes ptr & length sql/sql_select.cc: alias is now a String sql/sql_show.cc: alias is now a String sql/sql_string.h: Added move() function to change who owns the string (owner does the free) sql/sql_table.cc: alias is now a String c_ptr() -> c_ptr_safe() to avoid warnings from valgrind. sql/sql_test.cc: c_ptr() -> c_ptr_safe() to avoid warnings from valgrind. alias is now a String sql/sql_trigger.cc: c_ptr() -> c_ptr_safe() to avoid warnings from valgrind. Use field->init() to setup pointers to alias. sql/sql_update.cc: alias is now a String sql/sql_view.cc: ptr() -> c_ptr_safe() as string is not guaranteed to be \0 terminated sql/sql_yacc.yy: r() -> c_ptr() as string is not guaranteed to be \0 terminated sql/table.cc: alias is now a String sql/table.h: alias is now a String storage/federatedx/ha_federatedx.cc: Remove extra 1 byte alloc that is automaticly done by strmake() Ensure that error message ends with \0 storage/maria/ha_maria.cc: alias is now a String storage/myisam/ha_myisam.cc: alias is now a String	15 years ago
Sergey Petrunya	f93b0bbebb	MWL#90: subquery optimizations - Remove redundant changes againist 5.3-main	15 years ago
Sergey Petrunya	ef62320957	BUG#675118: Elimination of a table results in an invalid execution plan - Fix for MySQL BUG#52357 added NESTED_JOIN::is_fully_covered() which would not take into account that MariaDB's table elimination could eliminate tables from join plan (and so, from join nest). Fixed the check in the function to compare post-table-elimination numbers.	15 years ago
Igor Babaev	af800fd92f	The patch adds the code that allows to use equi-join conditions for hash join in the cases when there are no suitable indexes for these conditions.	15 years ago
Kent Boortz	85323eda8a	- Added/updated copyright headers - Removed files specific to compiling on OS/2 - Removed files specific to SCO Unix packaging - Removed "libmysqld/copyright", text is included in documentation - Removed LaTeX headers for NDB Doxygen documentation - Removed obsolete NDB files - Removed "mkisofs" binaries - Removed the "cvs2cl.pl" script - Changed a few GPL texts to use "program" instead of "library"	15 years ago
Kent Boortz	fddb1f1b13	- Added/updated copyright headers - Removed files specific to compiling on OS/2 - Removed files specific to SCO Unix packaging - Removed "libmysqld/copyright", text is included in documentation - Removed LaTeX headers for NDB Doxygen documentation - Removed obsolete NDB files - Removed "mkisofs" binaries - Removed the "cvs2cl.pl" script - Changed a few GPL texts to use "program" instead of "library"	15 years ago
Gleb Shchepa	086130e3c0	backport of bug #54476 fix from 5.1-bugteam to 5.0-bugteam. Original revid: alexey.kopytov@sun.com-20100723115254-jjwmhq97b9wl932l > Bug #54476: crash when group_concat and 'with rollup' in > prepared statements > > Using GROUP_CONCAT() together with the WITH ROLLUP modifier > could crash the server. > > The reason was a combination of several facts: > > 1. The Item_func_group_concat class stores pointers to ORDER > objects representing the columns in the ORDER BY clause of > GROUP_CONCAT(). > > 2. find_order_in_list() called from > Item_func_group_concat::setup() modifies the ORDER objects so > that their 'item' member points to the arguments list > allocated in the Item_func_group_concat constructor. > > 3. In some cases (e.g. in JOIN::rollup_make_fields) a copy of > the original Item_func_group_concat object could be created by > using the Item_func_group_concat::Item_func_group_concat(THD > thd, Item_func_group_concat item) copy constructor. The > latter essentially creates a shallow copy of the source > object. Memory for the arguments array is allocated on > thd->mem_root, but the pointers for arguments and ORDER are > copied verbatim. > > What happens in the test case is that when executing the query > for the first time, after a copy of the original > Item_func_group_concat object has been created by > JOIN::rollup_make_fields(), find_order_in_list() is called for > this new object. It then resolves ORDER BY by modifying the > ORDER objects so that they point to elements of the arguments > array which is local to the cloned object. When thd->mem_root > is freed upon completing the execution, pointers in the ORDER > objects become invalid. Those ORDER objects, however, are also > shared with the original Item_func_group_concat object which is > preserved between executions of a prepared statement. So the > first call to find_order_in_list() for the original object on > the second execution tries to dereference an invalid pointer. > > The solution is to create copies of the ORDER objects when > copying Item_func_group_concat to not leave any stale pointers > in other instances with different lifecycles. mysql-test/r/func_gconcat.result: Test case for bug #54476. mysql-test/t/func_gconcat.test: Test case for bug #54476. sql/item_sum.cc: Copy the ORDER objects pointed to by the elements of the 'order' array in the copy constructor of Item_func_group_concat. sql/table.h: Removed the unused 'item_copy' member of the ORDER class.	15 years ago
Gleb Shchepa	01521a0afb	backport of bug #54476 fix from 5.1-bugteam to 5.0-bugteam. Original revid: alexey.kopytov@sun.com-20100723115254-jjwmhq97b9wl932l > Bug #54476: crash when group_concat and 'with rollup' in > prepared statements > > Using GROUP_CONCAT() together with the WITH ROLLUP modifier > could crash the server. > > The reason was a combination of several facts: > > 1. The Item_func_group_concat class stores pointers to ORDER > objects representing the columns in the ORDER BY clause of > GROUP_CONCAT(). > > 2. find_order_in_list() called from > Item_func_group_concat::setup() modifies the ORDER objects so > that their 'item' member points to the arguments list > allocated in the Item_func_group_concat constructor. > > 3. In some cases (e.g. in JOIN::rollup_make_fields) a copy of > the original Item_func_group_concat object could be created by > using the Item_func_group_concat::Item_func_group_concat(THD > thd, Item_func_group_concat item) copy constructor. The > latter essentially creates a shallow copy of the source > object. Memory for the arguments array is allocated on > thd->mem_root, but the pointers for arguments and ORDER are > copied verbatim. > > What happens in the test case is that when executing the query > for the first time, after a copy of the original > Item_func_group_concat object has been created by > JOIN::rollup_make_fields(), find_order_in_list() is called for > this new object. It then resolves ORDER BY by modifying the > ORDER objects so that they point to elements of the arguments > array which is local to the cloned object. When thd->mem_root > is freed upon completing the execution, pointers in the ORDER > objects become invalid. Those ORDER objects, however, are also > shared with the original Item_func_group_concat object which is > preserved between executions of a prepared statement. So the > first call to find_order_in_list() for the original object on > the second execution tries to dereference an invalid pointer. > > The solution is to create copies of the ORDER objects when > copying Item_func_group_concat to not leave any stale pointers > in other instances with different lifecycles.	15 years ago
Igor Babaev	80377bbf6d	MWL #21 : "index_merge: non-ROR intersection". The second (final) patch.	15 years ago
Michael Widenius	52090a4434	Code cleanup to get fewer reallocs() during execution. - Changed TABLE->alias to String to get fewer reallocs when alias are used. - Preallocate some buffers Changed some String->c_ptr() -> String->ptr() when \0 is not needed. Fixed wrong usage of String->ptr() when we need a \0 terminated string. Use my_strtod() instead of my_atof() to avoid having to add \0 to string. c_ptr() -> c_ptr_safe() to avoid warnings from valgrind. zr sql/event_db_repository.cc: Update usage of TABLE->alias sql/event_scheduler.cc: c_ptr() -> c_ptr_safe() sql/events.cc: c_ptr() -> ptr() as \0 was not needed sql/field.cc: Update usage of TABLE->alias sql/field.h: Update usage of TABLE->alias sql/ha_partition.cc: Update usage of TABLE->alias sql/handler.cc: Update usage of TABLE->alias Fixed wrong usage of str.ptr() sql/item.cc: Fixed error where code wrongly assumed string was \0 terminated. sql/item_func.cc: c_ptr() -> c_ptr_safe() Update usage of TABLE->alias sql/item_sum.h: Use my_strtod() instead of my_atof() to avoid having to add \0 to string sql/lock.cc: Update usage of TABLE->alias sql/log.cc: c_ptr() -> ptr() as \0 was not needed sql/log_event.cc: c_ptr_quick() -> ptr() as \0 was not needed sql/opt_range.cc: ptr() -> c_ptr() as \0 is needed sql/opt_subselect.cc: Update usage of TABLE->alias sql/opt_table_elimination.cc: Update usage of TABLE->alias sql/set_var.cc: ptr() -> c_ptr() as \0 is needed c_ptr() -> c_ptr_safe() sql/sp.cc: c_ptr() -> ptr() as \0 was not needed sql/sp_rcontext.cc: Update usage of TABLE->alias sql/sql_base.cc: Preallocate buffers Update usage of TABLE->alias sql/sql_class.cc: Fix arguments to sprintf() to work even if string is not \0 terminated sql/sql_insert.cc: Update usage of TABLE->alias c_ptr() -> ptr() as \0 was not needed sql/sql_load.cc: Preallocate buffers Trivial optimizations sql/sql_parse.cc: Trivial optimization sql/sql_plugin.cc: c_ptr() -> ptr() as \0 was not needed sql/sql_select.cc: Update usage of TABLE->alias sql/sql_show.cc: Update usage of TABLE->alias sql/sql_string.h: Added move() function to move allocated memory from one object to another. sql/sql_table.cc: Update usage of TABLE->alias c_ptr() -> c_ptr_safe() sql/sql_test.cc: ptr() -> c_ptr_safe() sql/sql_trigger.cc: Update usage of TABLE->alias c_ptr() -> c_ptr_safe() sql/sql_update.cc: Update usage of TABLE->alias sql/sql_view.cc: ptr() -> c_ptr_safe() sql/sql_yacc.yy: ptr() -> c_ptr() sql/table.cc: Update usage of TABLE->alias sql/table.h: Changed TABLE->alias to String to get fewer reallocs when alias are used. storage/federatedx/ha_federatedx.cc: Use c_ptr_safe() to ensure strings are \0 terminated. storage/maria/ha_maria.cc: Update usage of TABLE->alias storage/myisam/ha_myisam.cc: Update usage of TABLE->alias storage/xtradb/row/row0sel.c: Ensure that null bits in record are properly reset. (Old code didn't work as row_search_for_mysql() can be called twice while reading fields from one row.	15 years ago
Dmitry Lenev	6bf6272fda	Patch that refactors global read lock implementation and fixes bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK" and bug #54673 "It takes too long to get readlock for 'FLUSH TABLES WITH READ LOCK'". The first bug manifested itself as a deadlock which occurred when a connection, which had some table open through HANDLER statement, tried to update some data through DML statement while another connection tried to execute FLUSH TABLES WITH READ LOCK concurrently. What happened was that FTWRL in the second connection managed to perform first step of GRL acquisition and thus blocked all upcoming DML. After that it started to wait for table open through HANDLER statement to be flushed. When the first connection tried to execute DML it has started to wait for GRL/the second connection creating deadlock. The second bug manifested itself as starvation of FLUSH TABLES WITH READ LOCK statements in cases when there was a constant stream of concurrent DML statements (in two or more connections). This has happened because requests for protection against GRL which were acquired by DML statements were ignoring presence of pending GRL and thus the latter was starved. This patch solves both these problems by re-implementing GRL using metadata locks. Similar to the old implementation acquisition of GRL in new implementation is two-step. During the first step we block all concurrent DML and DDL statements by acquiring global S metadata lock (each DML and DDL statement acquires global IX lock for its duration). During the second step we block commits by acquiring global S lock in COMMIT namespace (commit code acquires global IX lock in this namespace). Note that unlike in old implementation acquisition of protection against GRL in DML and DDL is semi-automatic. We assume that any statement which should be blocked by GRL will either open and acquires write-lock on tables or acquires metadata locks on objects it is going to modify. For any such statement global IX metadata lock is automatically acquired for its duration. The first problem is solved because waits for GRL become visible to deadlock detector in metadata locking subsystem and thus deadlocks like one in the first bug become impossible. The second problem is solved because global S locks which are used for GRL implementation are given preference over IX locks which are acquired by concurrent DML (and we can switch to fair scheduling in future if needed). Important change: FTWRL/GRL no longer blocks DML and DDL on temporary tables. Before this patch behavior was not consistent in this respect: in some cases DML/DDL statements on temporary tables were blocked while in others they were not. Since the main use cases for FTWRL are various forms of backups and temporary tables are not preserved during backups we have opted for consistently allowing DML/DDL on temporary tables during FTWRL/GRL. Important change: This patch changes thread state names which are used when DML/DDL of FTWRL is waiting for global read lock. It is now either "Waiting for global read lock" or "Waiting for commit lock" depending on the stage on which FTWRL is. Incompatible change: To solve deadlock in events code which was exposed by this patch we have to replace LOCK_event_metadata mutex with metadata locks on events. As result we have to prohibit DDL on events under LOCK TABLES. This patch also adds extensive test coverage for interaction of DML/DDL and FTWRL. Performance of new and old global read lock implementations in sysbench tests were compared. There were no significant difference between new and old implementations. mysql-test/include/check_ftwrl_compatible.inc: Added helper script which allows to check that a statement is compatible with FLUSH TABLES WITH READ LOCK. mysql-test/include/check_ftwrl_incompatible.inc: Added helper script which allows to check that a statement is incompatible with FLUSH TABLES WITH READ LOCK. mysql-test/include/handler.inc: Adjusted test case to the fact that now DROP TABLE closes open HANDLERs for the table to be dropped before checking if there active FTWRL in this connection. mysql-test/include/wait_show_condition.inc: Fixed small error in the timeout message. The correct name of variable used as parameter for this script is "$condition" and not "$wait_condition". mysql-test/r/delayed.result: Added test coverage for scenario which triggered assert in metadata locking subsystem. mysql-test/r/events_2.result: Updated test results after prohibiting event DDL operations under LOCK TABLES. mysql-test/r/flush.result: Added test coverage for bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK". mysql-test/r/flush_read_lock.result: Added test coverage for various aspects of FLUSH TABLES WITH READ LOCK functionality. mysql-test/r/flush_read_lock_kill.result: Adjusted test case after replacing custom global read lock implementation with one based on metadata locks. Use new debug_sync point. Do not disable concurrent inserts as now InnoDB we always use InnoDB table. mysql-test/r/handler_innodb.result: Adjusted test case to the fact that now DROP TABLE closes open HANDLERs for the table to be dropped before checking if there active FTWRL in this connection. mysql-test/r/handler_myisam.result: Adjusted test case to the fact that now DROP TABLE closes open HANDLERs for the table to be dropped before checking if there active FTWRL in this connection. mysql-test/r/mdl_sync.result: Adjusted test case after replacing custom global read lock implementation with one based on metadata locks. Replaced usage of GRL-specific debug_sync's with appropriate sync points in MDL subsystem. mysql-test/suite/perfschema/r/dml_setup_instruments.result: Updated test results after removing global COND_global_read_lock condition variable. mysql-test/suite/perfschema/r/func_file_io.result: Ensure that this test doesn't affect subsequent tests. At the end of its execution enable back P_S instrumentation which this test disables at some point. mysql-test/suite/perfschema/r/func_mutex.result: Ensure that this test doesn't affect subsequent tests. At the end of its execution enable back P_S instrumentation which this test disables at some point. mysql-test/suite/perfschema/r/global_read_lock.result: Adjusted test case to take into account that new GRL implementation is based on MDL. mysql-test/suite/perfschema/r/server_init.result: Adjusted test case after replacing custom global read lock implementation with one based on MDL and replacing LOCK_event_metadata mutex with metadata lock. mysql-test/suite/perfschema/t/func_file_io.test: Ensure that this test doesn't affect subsequent tests. At the end of its execution enable back P_S instrumentation which this test disables at some point. mysql-test/suite/perfschema/t/func_mutex.test: Ensure that this test doesn't affect subsequent tests. At the end of its execution enable back P_S instrumentation which this test disables at some point. mysql-test/suite/perfschema/t/global_read_lock.test: Adjusted test case to take into account that new GRL implementation is based on MDL. mysql-test/suite/perfschema/t/server_init.test: Adjusted test case after replacing custom global read lock implementation with one based on MDL and replacing LOCK_event_metadata mutex with metadata lock. mysql-test/suite/rpl/r/rpl_tmp_table_and_DDL.result: Updated test results after prohibiting event DDL under LOCK TABLES. mysql-test/t/delayed.test: Added test coverage for scenario which triggered assert in metadata locking subsystem. mysql-test/t/events_2.test: Updated test case after prohibiting event DDL operations under LOCK TABLES. mysql-test/t/flush.test: Added test coverage for bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK". mysql-test/t/flush_block_commit.test: Adjusted test case after changing thread state name which is used when COMMIT waits for FLUSH TABLES WITH READ LOCK from "Waiting for release of readlock" to "Waiting for commit lock". mysql-test/t/flush_block_commit_notembedded.test: Adjusted test case after changing thread state name which is used when DML waits for FLUSH TABLES WITH READ LOCK. Now we use "Waiting for global read lock" in this case. mysql-test/t/flush_read_lock.test: Added test coverage for various aspects of FLUSH TABLES WITH READ LOCK functionality. mysql-test/t/flush_read_lock_kill-master.opt: We no longer need to use make_global_read_lock_block_commit_loop debug tag in this test. Instead we rely on an appropriate debug_sync point in MDL code. mysql-test/t/flush_read_lock_kill.test: Adjusted test case after replacing custom global read lock implementation with one based on metadata locks. Use new debug_sync point. Do not disable concurrent inserts as now InnoDB we always use InnoDB table. mysql-test/t/lock_multi.test: Adjusted test case after changing thread state names which are used when DML or DDL waits for FLUSH TABLES WITH READ LOCK to "Waiting for global read lock". mysql-test/t/mdl_sync.test: Adjusted test case after replacing custom global read lock implementation with one based on metadata locks. Replaced usage of GRL-specific debug_sync's with appropriate sync points in MDL subsystem. Updated thread state names which are used when DDL waits for FTWRL. mysql-test/t/trigger_notembedded.test: Adjusted test case after changing thread state names which are used when DML or DDL waits for FLUSH TABLES WITH READ LOCK to "Waiting for global read lock". sql/event_data_objects.cc: Removed Event_queue_element::status/last_executed_changed members and Event_queue_element::update_timing_fields() method. We no longer use this class for updating mysql.events once event is chosen for execution. Accesses to instances of this class in scheduler thread require protection by Event_queue::LOCK_event_queue mutex and we try to avoid updating table while holding this lock. sql/event_data_objects.h: Removed Event_queue_element::status/last_executed_changed members and Event_queue_element::update_timing_fields() method. We no longer use this class for updating mysql.events once event is chosen for execution. Accesses to instances of this class in scheduler thread require protection by Event_queue::LOCK_event_queue mutex and we try to avoid updating table while holding this lock. sql/event_db_repository.cc: - Changed Event_db_repository methods to not release all metadata locks once they are done updating mysql.events table. This allows to keep metadata lock protecting against GRL and lock protecting particular event around until corresponding DDL statement is written to the binary log. - Removed logic for conditional update of "status" and "last_executed" fields from update_timing_fields_for_event() method. In the only case when this method is called now "last_executed" is always modified and tracking change of "status" is too much hassle. sql/event_db_repository.h: Removed logic for conditional update of "status" and "last_executed" fields from Event_db_repository:: update_timing_fields_for_event() method. In the only case when this method is called now "last_executed" is always modified and tracking change of "status" field is too much hassle. sql/event_queue.cc: Changed event scheduler code not to update mysql.events table while holding Event_queue::LOCK_event_queue mutex. Doing so led to a deadlock with a new GRL implementation. This deadlock didn't occur with old implementation due to fact that code acquiring protection against GRL ignored pending GRL requests (which lead to GRL starvation). One of goals of new implementation is to disallow GRL starvation and so we have to solve problem with this deadlock in a different way. sql/events.cc: Changed methods of Events class to acquire protection against GRL while perfoming DDL statement and keep it until statement is written to the binary log. Unfortunately this step together with new GRL implementation exposed deadlock involving Events::LOCK_event_metadata and GRL. To solve it Events::LOCK_event_metadata mutex was replaced with a metadata lock on event. As a side-effect events DDL has to be prohibited under LOCK TABLES even in cases when mysql.events table was explicitly locked for write. sql/events.h: Replaced Events::LOCK_event_metadata mutex with a metadata lock on event. sql/ha_ndbcluster.cc: Updated code after replacing custom global read lock implementation with one based on MDL. Since MDL subsystem should now be able to detect deadlocks involving metadata locks and GRL there is no need for special handling of active GRL. sql/handler.cc: Replaced custom implementation of global read lock with one based on metadata locks. Consequently when doing commit instead of calling method of Global_read_lock class to acquire protection against GRL we simply acquire IX in COMMIT namespace. sql/lock.cc: Replaced custom implementation of global read lock with one based on metadata locks. This step allows to expose wait for GRL to deadlock detector of MDL subsystem and thus succesfully resolve deadlocks similar to one behind bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK". It also solves problem with GRL starvation described in bug #54673 "It takes too long to get readlock for 'FLUSH TABLES WITH READ LOCK'" since metadata locks used by GRL give preference to FTWRL statement instead of DML statements (if needed in future this can be changed to fair scheduling). Similar to old implementation of acquisition of GRL is two-step. During the first step we block all concurrent DML and DDL statements by acquiring global S metadata lock (each DML and DDL statement acquires global IX lock for its duration). During the second step we block commits by acquiring global S lock in COMMIT namespace (commit code acquires global IX lock in this namespace). Note that unlike in old implementation acquisition of protection against GRL in DML and DDL is semi-automatic. We assume that any statement which should be blocked by GRL will either open and acquires write-lock on tables or acquires metadata locks on objects it is going to modify. For any such statement global IX metadata lock is automatically acquired for its duration. To support this change: - Global_read_lock::lock/unlock_global_read_lock and make_global_read_lock_block_commit methods were changed accordingly. - Global_read_lock::wait_if_global_read_lock() and start_waiting_global_read_lock() methods were dropped. It is now responsibility of code acquiring metadata locks opening tables to acquire protection against GRL by explicitly taking global IX lock with statement duration. - Global variables, mutex and condition variable used by old implementation was removed. - lock_routine_name() was changed to use statement duration for its global IX lock. It was also renamed to lock_object_name() as it now also used to take metadata locks on events. - Global_read_lock::set_explicit_lock_duration() was added which allows not to release locks used for GRL when leaving prelocked mode. sql/lock.h: - Renamed lock_routine_name() to lock_object_name() and changed its signature to allow its usage for events. - Removed broadcast_refresh() function. It is no longer needed with new GRL implementation. sql/log_event.cc: Release metadata locks with statement duration at the end of processing legacy event for LOAD DATA. This ensures that replication thread processing such event properly releases its protection against global read lock. sql/mdl.cc: Changed MDL subsystem to support new MDL-based implementation of global read lock. Added COMMIT and EVENTS namespaces for metadata locks. Changed thread state name for GLOBAL namespace to "Waiting for global read lock". Optimized MDL_map::find_or_insert() method to avoid taking m_mutex mutex when looking up MDL_lock objects for GLOBAL or COMMIT namespaces. We keep pre-created MDL_lock objects for these namespaces around and simply return pointers to these global objects when needed. Changed MDL_lock/MDL_scoped_lock to properly handle notification of insert delayed handler threads when FTWRL takes global S lock. Introduced concept of lock duration. In addition to locks with transaction duration which work in the way which is similar to how locks worked before (i.e. they are released at the end of transaction), locks with statement and explicit duration were introduced. Locks with statement duration are automatically released at the end of statement. Locks with explicit duration require explicit release and obsolete concept of transactional sentinel. * Changed MDL_request and MDL_ticket classes to support notion of duration. * Changed MDL_context to keep locks with different duration in different lists. Changed code handling ticket list to take this into account. * Changed methods responsible for releasing locks to take into account duration of tickets. Particularly public MDL_context::release_lock() method now only can release tickets with explicit duration (there is still internal method which allows to specify duration). To release locks with statement or transaction duration one have to use release_statement/transactional_locks() methods. * Concept of savepoint for MDL subsystem now has to take into account locks with statement duration. Consequently MDL_savepoint class was introduced and methods working with savepoints were updated accordingly. * Added methods which allow to set duration for one or all locks in the context. sql/mdl.h: Changed MDL subsystem to support new MDL-based implementation of global read lock. Added COMMIT and EVENTS namespaces for metadata locks. Introduced concept of lock duration. In addition to locks with transaction duration which work in the way which is similar to how locks worked before (i.e. they are released at the end of transaction), locks with statement and explicit duration were introduced. Locks with statement duration are automatically released at the end of statement. Locks with explicit duration require explicit release and obsolete concept of transactional sentinel. * Changed MDL_request and MDL_ticket classes to support notion of duration. * Changed MDL_context to keep locks with different duration in different lists. Changed code handling ticket list to take this into account. * Changed methods responsible for releasing locks to take into account duration of tickets. Particularly public MDL_context::release_lock() method now only can release tickets with explicit duration (there is still internal method which allows to specify duration). To release locks with statement or transaction duration one have to use release_statement/transactional_locks() methods. * Concept of savepoint for MDL subsystem now has to take into account locks with statement duration. Consequently MDL_savepoint class was introduced and methods working with savepoints were updated accordingly. * Added methods which allow to set duration for one or all locks in the context. sql/mysqld.cc: Removed global mutex and condition variables which were used by old implementation of GRL. Also we no longer need to initialize Events::LOCK_event_metadata mutex as it was replaced with metadata locks on events. sql/mysqld.h: Removed global variable, mutex and condition variables which were used by old implementation of GRL. sql/rpl_rli.cc: When slave thread closes tables which were open for handling of RBR events ensure that it releases global IX lock which was acquired as protection against GRL. sql/sp.cc: Adjusted code to the new signature of lock_object/routine_name(), to the fact that one now needs specify duration of lock when initializing MDL_request and to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. sql/sp_head.cc: Ensure that statements in stored procedures release statement metadata locks and thus release their protectiong against GRL in proper moment in time. Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request. sql/sql_admin.cc: Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request. sql/sql_base.cc: - Implemented support for new approach to acquiring protection against global read lock. We no longer acquire such protection explicitly on the basis of statement flags. Instead we always rely on code which is responsible for acquiring metadata locks on object to be changed acquiring this protection. This is achieved by acquiring global IX metadata lock with statement duration. Code doing this also responsible for checking that current connection has no active GRL by calling an Global_read_lock::can_acquire_protection() method. Changed code in open_table() and lock_table_names() accordingly. Note that as result of this change DDL and DML on temporary tables is always compatible with GRL (before it was incompatible in some cases and compatible in other cases). - To speed-up code acquiring protection against GRL introduced m_has_protection_against_grl member in Open_table_context class. It indicates that protection was already acquired sometime during open_tables() execution and new attempts can be skipped. - Thanks to new GRL implementation calls to broadcast_refresh() became unnecessary and were removed. - Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request and to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. sql/sql_base.h: Adjusted code to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. Also introduced Open_table_context::m_has_protection_against_grl member which allows to avoid acquiring protection against GRL while opening tables if such protection was already acquired. sql/sql_class.cc: Changed THD::leave_locked_tables_mode() after transactional sentinel for metadata locks was obsoleted by introduction of locks with explicit duration. sql/sql_class.h: - Adjusted code to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. - Changed Global_read_lock class according to changes in global read lock implementation: * wait_if_global_read_lock and start_waiting_global_read_lock are now gone. Instead code needing protection against GRL has to acquire global IX metadata lock with statement duration itself. To help it new can_acquire_protection() was introduced. Also as result of the above change m_protection_count member is gone too. * Added m_mdl_blocks_commits_lock member to store metadata lock blocking commits. * Adjusted code to the fact that concept of transactional sentinel was obsoleted by concept of lock duration. - Removed CF_PROTECT_AGAINST_GRL flag as it is no longer necessary. New GRL implementation acquires protection against global read lock automagically when statement acquires metadata locks on tables or other objects it is going to change. sql/sql_db.cc: Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request. sql/sql_handler.cc: Removed call to broadcast_refresh() function. It is no longer needed with new GRL implementation. Adjusted code after introducing duration concept for metadata locks. Particularly to the fact transactional sentinel was replaced with explicit duration. sql/sql_handler.h: Renamed mysql_ha_move_tickets_after_trans_sentinel() to mysql_ha_set_explicit_lock_duration() after transactional sentinel was obsoleted by locks with explicit duration. sql/sql_insert.cc: Adjusted code handling delaying inserts after switching to new GRL implementation. Now connection thread initiating delayed insert has to acquire global IX lock in addition to metadata lock on table being inserted into. This IX lock protects against GRL and similarly to SW lock on table being inserted into has to be passed to handler thread in order to avoid deadlocks. sql/sql_lex.cc: LEX::protect_against_global_read_lock member is no longer necessary since protection against GRL is automatically taken by code acquiring metadata locks/opening tables. sql/sql_lex.h: LEX::protect_against_global_read_lock member is no longer necessary since protection against GRL is automatically taken by code acquiring metadata locks/opening tables. sql/sql_parse.cc: - Implemented support for new approach to acquiring protection against global read lock. We no longer acquire such protection explicitly on the basis of statement flags. Instead we always rely on code which is responsible for acquiring metadata locks on object to be changed acquiring this protection. This is achieved by acquiring global IX metadata lock with statement duration. This lock is automatically released at the end of statement execution. - Changed implementation of CREATE/DROP PROCEDURE/FUNCTION not to release metadata locks and thus protection against of GRL in the middle of statement execution. - Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request and to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. sql/sql_prepare.cc: Adjusted code to the to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. sql/sql_rename.cc: With new GRL implementation there is no need to explicitly acquire protection against GRL before renaming tables. This happens automatically in code which acquires metadata locks on tables being renamed. sql/sql_show.cc: Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request and to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. sql/sql_table.cc: - With new GRL implementation there is no need to explicitly acquire protection against GRL before dropping tables. This happens automatically in code which acquires metadata locks on tables being dropped. - Changed mysql_alter_table() not to release lock on new table name explicitly and to rely on automatic release of locks at the end of statement instead. This was necessary since now MDL_context::release_lock() is supported only for locks for explicit duration. sql/sql_trigger.cc: With new GRL implementation there is no need to explicitly acquire protection against GRL before changing table triggers. This happens automatically in code which acquires metadata locks on tables which triggers are to be changed. sql/sql_update.cc: Fix bug exposed by GRL testing. During prepare phase acquire only S metadata locks instead of SW locks to keep prepare of multi-UPDATE compatible with concurrent LOCK TABLES WRITE and global read lock. sql/sql_view.cc: With new GRL implementation there is no need to explicitly acquire protection against GRL before creating view. This happens automatically in code which acquires metadata lock on view to be created. sql/sql_yacc.yy: LEX::protect_against_global_read_lock member is no longer necessary since protection against GRL is automatically taken by code acquiring metadata locks/opening tables. sql/table.cc: Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request. sql/table.h: Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request. sql/transaction.cc: Replaced custom implementation of global read lock with one based on metadata locks. Consequently when doing commit instead of calling method of Global_read_lock class to acquire protection against GRL we simply acquire IX in COMMIT namespace. Also adjusted code to the fact that MDL savepoint is now represented by MDL_savepoint class.	15 years ago
Dmitry Lenev	378cdc58c1	Patch that refactors global read lock implementation and fixes bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK" and bug #54673 "It takes too long to get readlock for 'FLUSH TABLES WITH READ LOCK'". The first bug manifested itself as a deadlock which occurred when a connection, which had some table open through HANDLER statement, tried to update some data through DML statement while another connection tried to execute FLUSH TABLES WITH READ LOCK concurrently. What happened was that FTWRL in the second connection managed to perform first step of GRL acquisition and thus blocked all upcoming DML. After that it started to wait for table open through HANDLER statement to be flushed. When the first connection tried to execute DML it has started to wait for GRL/the second connection creating deadlock. The second bug manifested itself as starvation of FLUSH TABLES WITH READ LOCK statements in cases when there was a constant stream of concurrent DML statements (in two or more connections). This has happened because requests for protection against GRL which were acquired by DML statements were ignoring presence of pending GRL and thus the latter was starved. This patch solves both these problems by re-implementing GRL using metadata locks. Similar to the old implementation acquisition of GRL in new implementation is two-step. During the first step we block all concurrent DML and DDL statements by acquiring global S metadata lock (each DML and DDL statement acquires global IX lock for its duration). During the second step we block commits by acquiring global S lock in COMMIT namespace (commit code acquires global IX lock in this namespace). Note that unlike in old implementation acquisition of protection against GRL in DML and DDL is semi-automatic. We assume that any statement which should be blocked by GRL will either open and acquires write-lock on tables or acquires metadata locks on objects it is going to modify. For any such statement global IX metadata lock is automatically acquired for its duration. The first problem is solved because waits for GRL become visible to deadlock detector in metadata locking subsystem and thus deadlocks like one in the first bug become impossible. The second problem is solved because global S locks which are used for GRL implementation are given preference over IX locks which are acquired by concurrent DML (and we can switch to fair scheduling in future if needed). Important change: FTWRL/GRL no longer blocks DML and DDL on temporary tables. Before this patch behavior was not consistent in this respect: in some cases DML/DDL statements on temporary tables were blocked while in others they were not. Since the main use cases for FTWRL are various forms of backups and temporary tables are not preserved during backups we have opted for consistently allowing DML/DDL on temporary tables during FTWRL/GRL. Important change: This patch changes thread state names which are used when DML/DDL of FTWRL is waiting for global read lock. It is now either "Waiting for global read lock" or "Waiting for commit lock" depending on the stage on which FTWRL is. Incompatible change: To solve deadlock in events code which was exposed by this patch we have to replace LOCK_event_metadata mutex with metadata locks on events. As result we have to prohibit DDL on events under LOCK TABLES. This patch also adds extensive test coverage for interaction of DML/DDL and FTWRL. Performance of new and old global read lock implementations in sysbench tests were compared. There were no significant difference between new and old implementations.	15 years ago
Davi Arnaut	a5efb91dea	Bug#49938: Failing assertion: inode or deadlock in fsp/fsp0fsp.c Bug#54678: InnoDB, TRUNCATE, ALTER, I_S SELECT, crash or deadlock - Incompatible change: truncate no longer resorts to a row by row delete if the storage engine does not support the truncate method. Consequently, the count of affected rows does not, in any case, reflect the actual number of rows. - Incompatible change: it is no longer possible to truncate a table that participates as a parent in a foreign key constraint, unless it is a self-referencing constraint (both parent and child are in the same table). To work around this incompatible change and still be able to truncate such tables, disable foreign checks with SET foreign_key_checks=0 before truncate. Alternatively, if foreign key checks are necessary, please use a DELETE statement without a WHERE condition. Problem description: The problem was that for storage engines that do not support truncate table via a external drop and recreate, such as InnoDB which implements truncate via a internal drop and recreate, the delete_all_rows method could be invoked with a shared metadata lock, causing problems if the engine needed exclusive access to some internal metadata. This problem originated with the fact that there is no truncate specific handler method, which ended up leading to a abuse of the delete_all_rows method that is primarily used for delete operations without a condition. Solution: The solution is to introduce a truncate handler method that is invoked when the engine does not support truncation via a table drop and recreate. This method is invoked under a exclusive metadata lock, so that there is only a single instance of the table when the method is invoked. Also, the method is not invoked and a error is thrown if the table is a parent in a non-self-referencing foreign key relationship. This was necessary to avoid inconsistency as some integrity checks are bypassed. This is inline with the fact that truncate is primarily a DDL operation that was designed to quickly remove all data from a table. mysql-test/suite/innodb/t/innodb-truncate.test: Add test cases for truncate and foreign key checks. Also test that InnoDB resets auto-increment on truncate. mysql-test/suite/innodb/t/innodb.test: FK is not necessary, test is related to auto-increment. Update error number, truncate is no longer invoked if table is parent in a FK relationship. mysql-test/suite/innodb/t/innodb_mysql.test: Update error number, truncate is no longer invoked if table is parent in a FK relationship. Use delete instead of truncate, test is used to check the interaction of FKs, triggers and delete. mysql-test/suite/parts/inc/partition_check.inc: Fix typo. mysql-test/suite/sys_vars/t/foreign_key_checks_func.test: Update error number, truncate is no longer invoked if table is parent in a FK relationship. mysql-test/t/mdl_sync.test: Modify test case to reflect and ensure that truncate takes a exclusive metadata lock. mysql-test/t/trigger-trans.test: Update error number, truncate is no longer invoked if table is parent in a FK relationship. sql/ha_partition.cc: Reorganize the various truncate methods. delete_all_rows is now passed directly to the underlying engines, so as truncate. The code responsible for truncating individual partitions is moved to ha_partition::truncate_partition, which is invoked when a ALTER TABLE t1 TRUNCATE PARTITION p statement is executed. Since the partition truncate no longer can be invoked via delete, the bitmap operations are not necessary anymore. The explicit reset of the auto-increment value is also removed as the underlying engines are now responsible for reseting the value. sql/handler.cc: Wire up the handler truncate method. sql/handler.h: Introduce and document the truncate handler method. It assumes certain use cases of delete_all_rows. Add method to retrieve the list of foreign keys referencing a table. Method is used to avoid truncating tables that are parent in a foreign key relationship. sql/share/errmsg-utf8.txt: Add error message for truncate and FK. sql/sql_lex.h: Introduce a flag so that the partition engine can detect when a partition is being truncated. Used to give a special error. sql/sql_parse.cc: Function mysql_truncate_table no longer exists. sql/sql_partition_admin.cc: Implement the TRUNCATE PARTITION statement. sql/sql_truncate.cc: Change the truncate table implementation to use the new truncate handler method and to not rely on row-by-row delete anymore. The truncate handler method is always invoked with a exclusive metadata lock. Also, it is no longer possible to truncate a table that is parent in some non-self-referencing foreign key. storage/archive/ha_archive.cc: Rename method as the description indicates that in the future this could be a truncate operation. storage/blackhole/ha_blackhole.cc: Implement truncate as no operation for the blackhole engine in order to remain compatible with older releases. storage/federated/ha_federated.cc: Introduce truncate method that invokes delete_all_rows. This is required to support partition truncate as this form of truncate does not implement the drop and recreate protocol. storage/heap/ha_heap.cc: Introduce truncate method that invokes delete_all_rows. This is required to support partition truncate as this form of truncate does not implement the drop and recreate protocol. storage/ibmdb2i/ha_ibmdb2i.cc: Introduce truncate method that invokes delete_all_rows. This is required to support partition truncate as this form of truncate does not implement the drop and recreate protocol. storage/innobase/handler/ha_innodb.cc: Rename delete_all_rows to truncate. InnoDB now does truncate under a exclusive metadata lock. Introduce and reorganize methods used to retrieve the list of foreign keys referenced by a or referencing a table. storage/myisammrg/ha_myisammrg.cc: Introduce truncate method that invokes delete_all_rows. This is required in order to remain compatible with earlier releases where truncate would resort to a row-by-row delete.	15 years ago
Davi Arnaut	5f911fa874	Bug#49938: Failing assertion: inode or deadlock in fsp/fsp0fsp.c Bug#54678: InnoDB, TRUNCATE, ALTER, I_S SELECT, crash or deadlock - Incompatible change: truncate no longer resorts to a row by row delete if the storage engine does not support the truncate method. Consequently, the count of affected rows does not, in any case, reflect the actual number of rows. - Incompatible change: it is no longer possible to truncate a table that participates as a parent in a foreign key constraint, unless it is a self-referencing constraint (both parent and child are in the same table). To work around this incompatible change and still be able to truncate such tables, disable foreign checks with SET foreign_key_checks=0 before truncate. Alternatively, if foreign key checks are necessary, please use a DELETE statement without a WHERE condition. Problem description: The problem was that for storage engines that do not support truncate table via a external drop and recreate, such as InnoDB which implements truncate via a internal drop and recreate, the delete_all_rows method could be invoked with a shared metadata lock, causing problems if the engine needed exclusive access to some internal metadata. This problem originated with the fact that there is no truncate specific handler method, which ended up leading to a abuse of the delete_all_rows method that is primarily used for delete operations without a condition. Solution: The solution is to introduce a truncate handler method that is invoked when the engine does not support truncation via a table drop and recreate. This method is invoked under a exclusive metadata lock, so that there is only a single instance of the table when the method is invoked. Also, the method is not invoked and a error is thrown if the table is a parent in a non-self-referencing foreign key relationship. This was necessary to avoid inconsistency as some integrity checks are bypassed. This is inline with the fact that truncate is primarily a DDL operation that was designed to quickly remove all data from a table.	15 years ago
Mattias Jonsson	814fbc5b6f	Bug#51851: Server with SBR locks mutex twice on LOAD DATA into partitioned MyISAM table Problem was that both partitioning and myisam used the same table_share->mutex for different protections (auto inc and repair). Solved by adding a specific mutex for the partitioning auto_increment. Also adding destroying the ha_data structure in free_table_share (which is to be propagated into 5.5). This is a 5.1 ONLY patch, already fixed in 5.5+.	15 years ago
Mattias Jonsson	a01773dbee	Bug#51851: Server with SBR locks mutex twice on LOAD DATA into partitioned MyISAM table Problem was that both partitioning and myisam used the same table_share->mutex for different protections (auto inc and repair). Solved by adding a specific mutex for the partitioning auto_increment. Also adding destroying the ha_data structure in free_table_share (which is to be propagated into 5.5). This is a 5.1 ONLY patch, already fixed in 5.5+.	15 years ago
unknown	0394cf2030	MWL#116: Efficient group commit for binary log Preliminary commit for testing	15 years ago
Michael Widenius	bdba1d11c4	Change some my_bool in C++ classes and a few functions to bool to detect wrong usage of bool/my_bool. Fix some bugs where we stored values other than 0 or 1 in my_bool Fixed some compiler warnings client/mysql.cc: Changed interrupted_query from my_bool to int, as we stored 2 in it. client/mysqladmin.cc: Changed return variable type to same type as function value type client/mysqltest.cc: Changed 'found' to int as we store other values than 0 or 1 into it Changed type for parameter of set_reconnect() to match usage. extra/libevent/evbuffer.c: Added __attribute__((unused)) extra/libevent/event.c: Added __attribute__((unused)) extra/libevent/signal.c: Added __attribute__((unused)) sql/event_data_objects.h: my_bool -> bool sql/event_db_repository.cc: my_bool -> bool sql/event_db_repository.h: my_bool -> bool sql/event_parse_data.h: my_bool -> bool sql/events.cc: my_bool -> bool sql/events.h: my_bool -> bool sql/field.cc: my_bool -> bool sql/field.h: my_bool -> bool sql/hash_filo.h: my_bool -> bool sql/item.cc: my_bool -> bool sql/item.h: my_bool -> bool sql/item_cmpfunc.h: my_bool -> bool Changed result_for_null_param from my_bool to int as we stored -1 in it. sql/item_func.cc: my_bool -> bool Modified udf wrapper functions so that the UDF functions would continue to use my_bool. (To keep compatibility with UDF:s) sql/item_func.h: my_bool -> bool sql/item_subselect.h: my_bool -> bool sql/item_sum.cc: Modified udf wrapper functions so that the UDF functions would continue to use my_bool. (To keep compatibility with UDF:s) sql/parse_file.h: my_bool -> bool sql/rpl_mi.h: my_bool -> bool sql/sp_rcontext.h: my_bool -> bool sql/sql_analyse.h: my_bool -> bool sql/sql_base.cc: Change some assignments so that we don't initialize bool variables with int's. sql/sql_bitmap.h: my_bool -> bool sql/sql_cache.cc: my_bool -> bool sql/sql_cache.h: my_bool -> bool sql/sql_class.h: my_bool -> bool sql/sql_insert.cc: Change some assignments so that we don't initialize bool variables with int's. sql/sql_prepare.cc: my_bool -> bool sql/table.h: my_bool -> bool storage/maria/ma_check.c: Removed duplicate assignment strings/decimal.c: Fixed wrong variable usage. Don't do complex arithmetic on bool when simple works.	15 years ago
unknown	11dc256ca4		15 years ago
Alexander Nozdrin	b4badf8013	Remove unused enum (enum open_table_mode). It was added by mistake during backport from 6.0.	15 years ago
Alexander Nozdrin	1f1eba3c68	Remove unused enum (enum open_table_mode). It was added by mistake during backport from 6.0.	15 years ago
Alexander Nozdrin	4fcb173c41	Bug#27480 (Extend CREATE TEMPORARY TABLES privilege to allow temp table operations) -- prerequisite patch #1. Move a piece of code that initialiazes TABLE instance after it was successfully opened into a separate function. This function will be reused in the following patches.	15 years ago
Alexander Nozdrin	0142c14a6b	Bug#27480 (Extend CREATE TEMPORARY TABLES privilege to allow temp table operations) -- prerequisite patch #1. Move a piece of code that initialiazes TABLE instance after it was successfully opened into a separate function. This function will be reused in the following patches.	15 years ago
unknown	d0d8bbed5e	WL#5370 Keep forward-compatibility when changing 'CREATE TABLE IF NOT EXISTS ... SELECT' behaviour BUG#47132, BUG#47442, BUG49494, BUG#23992 and BUG#48814 will disappear automatically after the this patch. BUG#55617 is fixed by this patch too. This is the 5.5 part. It implements: - 'CREATE TABLE IF NOT EXISTS ... SELECT' statement will not insert anything and binlog anything if the table already exists. It only generate a warning that table already exists. - A couple of test cases for the behavior changing.	15 years ago
	d3b7cd3ff2	WL#5370 Keep forward-compatibility when changing 'CREATE TABLE IF NOT EXISTS ... SELECT' behaviour BUG#47132, BUG#47442, BUG49494, BUG#23992 and BUG#48814 will disappear automatically after the this patch. BUG#55617 is fixed by this patch too. This is the 5.5 part. It implements: - 'CREATE TABLE IF NOT EXISTS ... SELECT' statement will not insert anything and binlog anything if the table already exists. It only generate a warning that table already exists. - A couple of test cases for the behavior changing.	15 years ago
Mattias Jonsson	daf0e6b725	Bug#53676: Unexpected errors and possible table corruption on ADD PARTITION and LOCK TABLE Bug#53770: Server crash at handler.cc:2076 on LOAD DATA after timed out COALESCE PARTITION 5.5 fix for: Bug#51042: REORGANIZE PARTITION can leave table in an inconsistent state in case of crash Needs to be back-ported to 5.1 5.5 fix for: Bug#50418: DROP PARTITION does not interact with transactions Main problem was non-persistent operations done before meta-data lock was taken (53770+53676). And 53676 needed to keep the table/partitions opened and locked while copying the data to the new partitions. Also added thorough tests to spot some additional bugs in the ddl_log code, which could result in bad state between the .frm and partitions. Collapsed patch, includes all fixes required from the reviewers. mysql-test/r/partition_innodb.result: updated result with new test mysql-test/suite/parts/inc/partition_crash.inc: crash test include file mysql-test/suite/parts/inc/partition_crash_add.inc: test all states in fast_alter_partition_table ADD PARTITION branch mysql-test/suite/parts/inc/partition_crash_change.inc: test all states in fast_alter_partition_table CHANGE PARTITION branch mysql-test/suite/parts/inc/partition_crash_drop.inc: test all states in fast_alter_partition_table DROP PARTITION branch mysql-test/suite/parts/inc/partition_fail.inc: recovery test including injecting errors mysql-test/suite/parts/inc/partition_fail_add.inc: test all states in fast_alter_partition_table ADD PARTITION branch mysql-test/suite/parts/inc/partition_fail_change.inc: test all states in fast_alter_partition_table CHANGE PARTITION branch mysql-test/suite/parts/inc/partition_fail_drop.inc: test all states in fast_alter_partition_table DROP PARTITION branch mysql-test/suite/parts/inc/partition_mgm_crash.inc: include file that runs all crash and failure injection tests. mysql-test/suite/parts/r/partition_debug_innodb.result: new test result file mysql-test/suite/parts/r/partition_debug_myisam.result: new test result file mysql-test/suite/parts/r/partition_special_innodb.result: updated result mysql-test/suite/parts/r/partition_special_myisam.result: updated result mysql-test/suite/parts/t/partition_debug_innodb-master.opt: opt file for using with crashing tests of partitioned innodb mysql-test/suite/parts/t/partition_debug_innodb.test: partitioned innodb test that require debug builds mysql-test/suite/parts/t/partition_debug_myisam-master.opt: opt file for using with crashing tests of partitioned myisam mysql-test/suite/parts/t/partition_debug_myisam.test: partitioned myisam test that require debug builds mysql-test/suite/parts/t/partition_special_innodb-master.opt: added innodb-file-per-table to easier verify partition status on disk mysql-test/suite/parts/t/partition_special_innodb.test: added test case mysql-test/suite/parts/t/partition_special_myisam.test: added test case mysql-test/t/partition_innodb.test: added test case sql/sql_base.cc: Moved alter_close_tables to sql_partition.cc sql/sql_base.h: removed some non existing and duplicated functions. sql/sql_partition.cc: fast_alter_partition_table: Spletted abort_and_upgrad_lock_and_close_table to its parts (wait_while_table_is_used and alter_close_tables) and always have wait_while_table_is_used before any persistent operations (including logs, which will be executed on failure) and alter_close_tables after create/read/write operations and before drop operations. moved alter_close_tables here from sql_base.cc Added error injections for better test coverage. write_log_final_change_partition: fixed a log_entry linking bug (delete_frm was not linked to change/drop partition) and drop partition must be executed before change partition (change partition can rename a partition to an old name, like REORG p1 INTO (p1,p2). write_log_add_change_partition: need to use drop_frm first, and relinking that entry and reusing its execute entry. sql/sql_table.cc: added initialization of next_active_log_entry. sql/table.h: removed a duplicate declaration.	15 years ago
Mattias Jonsson	9a7a64acdb	Bug#53676: Unexpected errors and possible table corruption on ADD PARTITION and LOCK TABLE Bug#53770: Server crash at handler.cc:2076 on LOAD DATA after timed out COALESCE PARTITION 5.5 fix for: Bug#51042: REORGANIZE PARTITION can leave table in an inconsistent state in case of crash Needs to be back-ported to 5.1 5.5 fix for: Bug#50418: DROP PARTITION does not interact with transactions Main problem was non-persistent operations done before meta-data lock was taken (53770+53676). And 53676 needed to keep the table/partitions opened and locked while copying the data to the new partitions. Also added thorough tests to spot some additional bugs in the ddl_log code, which could result in bad state between the .frm and partitions. Collapsed patch, includes all fixes required from the reviewers.	15 years ago
Michael Widenius	cd9706b27e	Fixes bug when we run bcmp() on row when the storage engine hasn't filled in all fields in the row. This was triggered by innodb.innodb_multi_update, where we had a static length row without nulls and xtradb didn't fill in the delete-marker byte include/my_bitmap.h: Added prototype for bitmap_union_is_set_all() mysys/my_bitmap.c: Added function to check if union of two bit maps covers all bits. sql/mysql_priv.h: Updated protype for compare_record() sql/sql_insert.cc: Send to compare_record() flag if all fields are used. sql/sql_select.cc: Set share->null_bytes_for_compare. sql/sql_update.cc: In compare_record() don't use the fast cmp_record() (which is basically memcmp) if we don't know that all fields exists. Don't compare the null_bytes if there is no data there. sql/table.cc: Store in share->null_bytes_for_compare the number of bytes that has null or bit fields (but not delete marker) Store in can_cmp_whole_record if we can use memcmp() (assuming all rows are read) to compare rows in compare_record() sql/table.h: Added two elements in table->share to speed up checking how updated rows can be compared.	15 years ago
unknown	2124538d9c	BUG#49124 Security issue with /!-versioned / SQL statements on Slave /![:version:] Query Code /, where [:version:] is a sequence of 5 digits representing the mysql server version(e.g /!50200 ... /), is a special comment that the query in it can be executed on those servers whose versions are larger than the version appearing in the comment. It leads to a security issue when slave's version is larger than master's. A malicious user can improve his privileges on slaves. Because slave SQL thread is running with SUPER privileges, so it can execute queries that he/she does not have privileges on master. This bug is fixed with the logic below: - To replace '!' with ' ' in the magic comments which are not applied on master. So they become common comments and will not be applied on slave. - Example: 'INSERT INTO t1 VALUES (1) /!10000, (2)/ /!99999 ,(3)/ will be binlogged as 'INSERT INTO t1 VALUES (1) /!10000, (2)/ /* 99999 ,(3)*/ mysql-test/suite/rpl/t/rpl_conditional_comments.test: Test the patch for this bug. sql/mysql_priv.h: Rename inBuf as rawBuf and remove the const limitation. sql/sql_lex.cc: To replace '!' with ' ' in the magic comments which are not applied on master. sql/sql_lex.h: Remove the const limitation on parameter buff, as it can be modified in the function since this patch. Add member function yyUnput for Lex_input_stream. It set a character back the query buff. sql/sql_parse.cc: Rename inBuf as rawBuf and remove the const limitation. sql/sql_partition.cc: Remove the const limitation on parameter part_buff, as it can be modified in the function since this patch. sql/sql_partition.h: Remove the const limitation on parameter part_buff, as it can be modified in the function since this patch. sql/table.h: Remove the const limitation on variable partition_info, as it can be modified since this patch.	16 years ago
	2ad690fdf8	BUG#49124 Security issue with /!-versioned / SQL statements on Slave /![:version:] Query Code /, where [:version:] is a sequence of 5 digits representing the mysql server version(e.g /!50200 ... /), is a special comment that the query in it can be executed on those servers whose versions are larger than the version appearing in the comment. It leads to a security issue when slave's version is larger than master's. A malicious user can improve his privileges on slaves. Because slave SQL thread is running with SUPER privileges, so it can execute queries that he/she does not have privileges on master. This bug is fixed with the logic below: - To replace '!' with ' ' in the magic comments which are not applied on master. So they become common comments and will not be applied on slave. - Example: 'INSERT INTO t1 VALUES (1) /!10000, (2)/ /!99999 ,(3)/ will be binlogged as 'INSERT INTO t1 VALUES (1) /!10000, (2)/ /* 99999 ,(3)*/	16 years ago
Dmitry Lenev	00496b7acd	Fix for bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH TABLES <list> WITH READ LOCK are incompatible". The problem was that FLUSH TABLES <list> WITH READ LOCK which was issued when other connection has acquired global read lock using FLUSH TABLES WITH READ LOCK was blocked and has to wait until global read lock is released. This issue stemmed from the fact that FLUSH TABLES <list> WITH READ LOCK implementation has acquired X metadata locks on tables to be flushed. Since these locks required acquiring of global IX lock this statement was incompatible with global read lock. This patch addresses problem by using SNW metadata type of lock for tables to be flushed by FLUSH TABLES <list> WITH READ LOCK. It is OK to acquire them without global IX lock as long as we won't try to upgrade those locks. Since SNW locks allow concurrent statements using same table FLUSH TABLE <list> WITH READ LOCK now has to wait until old versions of tables to be flushed go away after acquiring metadata locks. Since such waiting can lead to deadlock MDL deadlock detector was extended to take into account waits for flush and resolve such deadlocks. As a bonus code in open_tables() which was responsible for waiting old versions of tables to go away was refactored. Now when we encounter old version of table in open_table() we don't back-off and wait for all old version to go away, but instead wait for this particular table to be flushed. Such approach supported by deadlock detection should reduce number of scenarios in which FLUSH TABLES aborts concurrent multi-statement transactions. Note that active FLUSH TABLES <list> WITH READ LOCK still blocks concurrent FLUSH TABLES WITH READ LOCK statement as the former keeps tables open and thus prevents the latter statement from doing flush. mysql-test/include/handler.inc: Adjusted test case after changing status which is set when FLUSH TABLES waits for tables to be flushed from "Flushing tables" to "Waiting for table". mysql-test/r/flush.result: Added test which checks that "flush tables <list> with read lock" is compatible with active "flush tables with read lock" but not vice-versa. This test also covers bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH TABLES <list> WITH READ LOCK are incompatible". mysql-test/r/mdl_sync.result: Added scenarios in which wait for table to be flushed causes deadlocks to the coverage of MDL deadlock detector. mysql-test/suite/perfschema/r/dml_setup_instruments.result: Adjusted test results after removal of COND_refresh condition variable. mysql-test/suite/perfschema/r/server_init.result: Adjusted test and its results after removal of COND_refresh condition variable. mysql-test/suite/perfschema/t/server_init.test: Adjusted test and its results after removal of COND_refresh condition variable. mysql-test/t/flush.test: Added test which checks that "flush tables <list> with read lock" is compatible with active "flush tables with read lock" but not vice-versa. This test also covers bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH TABLES <list> WITH READ LOCK are incompatible". mysql-test/t/kill.test: Adjusted test case after changing status which is set when FLUSH TABLES waits for tables to be flushed from "Flushing tables" to "Waiting for table". mysql-test/t/lock_multi.test: Adjusted test case after changing status which is set when FLUSH TABLES waits for tables to be flushed from "Flushing tables" to "Waiting for table". mysql-test/t/mdl_sync.test: Added scenarios in which wait for table to be flushed causes deadlocks to the coverage of MDL deadlock detector. sql/ha_ndbcluster.cc: Adjusted code after adding one more parameter for close_cached_tables() call - timeout for waiting for table to be flushed. sql/ha_ndbcluster_binlog.cc: Adjusted code after adding one more parameter for close_cached_tables() call - timeout for waiting for table to be flushed. sql/lock.cc: Removed COND_refresh condition variable. See comment for sql_base.cc for details. sql/mdl.cc: Now MDL deadlock detector takes into account information about waits for table flushes when searching for deadlock. To implement this change: - Declaration of enum_deadlock_weight and Deadlock_detection_visitor were moved to mdl.h header to make them available to the code in table.cc which implements deadlock detector traversal through edges of waiters graph representing waiting for flush. - Since now MDL_context may wait not only for metadata lock but also for table to be flushed an abstract Wait_for_edge class was introduced. Its descendants MDL_ticket and Flush_ticket incapsulate specifics of inspecting waiters graph when following through edge representing wait of particular type. We no longer require global IX metadata lock when acquiring SNW or SNRW locks. Such locks are needed only when metadata locks of these types are upgraded to X locks. This allows to use SNW locks in FLUSH TABLES <list> WITH READ LOCK implementation and keep the latter compatible with global read lock. sql/mdl.h: Now MDL deadlock detector takes into account information about waits for table flushes when searching for deadlock. To implement this change: - Declaration of enum_deadlock_weight and Deadlock_detection_visitor were moved to mdl.h header to make them available to the code in table.cc which implements deadlock detector traversal through edges of waiters graph representing waiting for flush. - Since now MDL_context may wait not only for metadata lock but also for table to be flushed an abstract Wait_for_edge class was introduced. Its descendants MDL_ticket and Flush_ticket incapsulate specifics of inspecting waiters graph when following through edge representing wait of particular type. - Deadlock_detection_visitor now has m_table_shares_visited member which allows to support recursive locking for LOCK_open. This is required when deadlock detector inspects waiters graph which contains several edges representing waits for flushes or needs to come through the such edge more than once. sql/mysqld.cc: Removed COND_refresh condition variable. See comment for sql_base.cc for details. sql/mysqld.h: Removed COND_refresh condition variable. See comment for sql_base.cc for details. sql/sql_base.cc: Changed approach to how threads are waiting for table to be flushed. Now thread that wants to wait for old table to go away subscribes for notification by adding Flush_ticket to table's share and waits using MDL_context::m_wait object. Once table gets flushed (i.e. all tables are closed and table share is ready to be destroyed) all such waiters are notified individually. Thanks to this change MDL deadlock detector can take such waits into account. To implement this/as result of this change: - tdc_wait_for_old_versions() was replaced with tdc_wait_for_old_version() which waits for individual old share to go away and which is called by open_table() after finding out that share is outdated. We don't need to perform back-off before such waiting thanks to the fact that deadlock detector now sees such waits. - As result Open_table_ctx::m_mdl_requests became unnecessary and was removed. We no longer allocate copies of MDL_request objects on MEM_ROOT when MYSQL_OPEN_FORCE_SHARED/SHARED_HIGH_PRIO flags are in effect. - close_cached_tables() and tdc_wait_for_old_version() share code which implements waiting for share to be flushed - the both use TABLE_SHARE::wait_until_flush() method. Thanks to this close_cached_tables() supports timeouts and has extra parameter for this. - Open_table_context::OT_MDL_CONFLICT enum element was renamed to OT_CONFLICT as it is now also used in cases when back-off is required to resolve deadlock caused by waiting for flush and not metadata lock. - In cases when we discover that current connection tries to open tables from different generation we now simply back-off and restart process of opening tables. To support this Open_table_context::OT_REOPEN_TABLES enum element was added. - COND_refresh condition variable became unnecessary and was removed. - mysql_notify_thread_having_shared_lock() no longer wakes up connections waiting for flush as all such connections can be waken up by deadlock detector if necessary. sql/sql_base.h: - close_cached_tables() now has one more parameter - timeout for waiting for table to be flushed. - Open_table_context::OT_MDL_CONFLICT enum element was renamed to OT_CONFLICT as it is now also used in cases when back-off is required to resolve deadlock caused by waiting for flush and not metadata lock. Added new OT_REOPEN_TABLES enum element to be used in cases when we need to restart open tables process even in the middle of transaction. - Open_table_ctx::m_mdl_requests became unnecessary and was removed. sql/sql_class.h: Added assert ensuring that we won't use LOCK_open mutex with THD::enter_cond(). Otherwise deadlocks can arise in MDL deadlock detector. sql/sql_parse.cc: Changed FLUSH TABLES <list> WITH READ LOCK to take SNW metadata locks instead of X locks on tables to be flushed. Since we no longer require global IX lock to be taken when SNW locks are taken this makes this statement compatible with FLUSH TABLES WITH READ LOCK statement. Since SNW locks allow other connections to have table opened FLUSH TABLES <list> WITH READ LOCK now has to wait during open_tables() for old version to go away. Such waits can lead to deadlocks which will be detected by MDL deadlock detector which now takes waits for table to be flushed into account. Also adjusted code after adding one more parameter for close_cached_tables() call - timeout for waiting for table to be flushed. sql/sql_yacc.yy: FLUSH TABLES <list> WITH READ LOCK now needs only SNW metadata locks on tables. sql/sys_vars.cc: Adjusted code after adding one more parameter for close_cached_tables() call - timeout for waiting for table to be flushed. sql/table.cc: Implemented new approach to how threads are waiting for table to be flushed. Now thread that wants to wait for old table to go away subscribes for notification by adding Flush_ticket to table's share and waits using MDL_context::m_wait object. Once table gets flushed (i.e. all tables are closed and table share is ready to be destroyed) all such waiters are notified individually. This change allows to make such waits visible inside of MDL deadlock detector. To do it: - Added list of waiters/Flush_tickets to TABLE_SHARE class. - Changed free_table_share() to postpone freeing of share memory until last waiter goes away and to wake up subscribed waiters. - Added TABLE_SHARE::wait_until_flushed() method which implements subscription to the list of waiters for table to be flushed and waiting for this event. Implemented interface which allows to expose waits for flushes to MDL deadlock detector: - Introduced Flush_ticket class a descendant of Wait_for_edge class. - Added TABLE_SHARE::find_deadlock() method which allows deadlock detector to find out what contexts are still using old version of table in question (i.e. to find out what contexts are waited for by owner of Flush_ticket). sql/table.h: In order to support new strategy of waiting for table flush (see comment for table.cc for details) added list of waiters/Flush_tickets to TABLE_SHARE class. Implemented interface which allows to expose waits for flushes to MDL deadlock detector: - Introduced Flush_ticket class a descendant of Wait_for_edge class. - Added TABLE_SHARE::find_deadlock() method which allows deadlock detector to find out what contexts are still using old version of table in question (i.e. to find out what contexts are waited for by owner of Flush_ticket).	16 years ago
Dmitry Lenev	5fff906edd	Fix for bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH TABLES <list> WITH READ LOCK are incompatible". The problem was that FLUSH TABLES <list> WITH READ LOCK which was issued when other connection has acquired global read lock using FLUSH TABLES WITH READ LOCK was blocked and has to wait until global read lock is released. This issue stemmed from the fact that FLUSH TABLES <list> WITH READ LOCK implementation has acquired X metadata locks on tables to be flushed. Since these locks required acquiring of global IX lock this statement was incompatible with global read lock. This patch addresses problem by using SNW metadata type of lock for tables to be flushed by FLUSH TABLES <list> WITH READ LOCK. It is OK to acquire them without global IX lock as long as we won't try to upgrade those locks. Since SNW locks allow concurrent statements using same table FLUSH TABLE <list> WITH READ LOCK now has to wait until old versions of tables to be flushed go away after acquiring metadata locks. Since such waiting can lead to deadlock MDL deadlock detector was extended to take into account waits for flush and resolve such deadlocks. As a bonus code in open_tables() which was responsible for waiting old versions of tables to go away was refactored. Now when we encounter old version of table in open_table() we don't back-off and wait for all old version to go away, but instead wait for this particular table to be flushed. Such approach supported by deadlock detection should reduce number of scenarios in which FLUSH TABLES aborts concurrent multi-statement transactions. Note that active FLUSH TABLES <list> WITH READ LOCK still blocks concurrent FLUSH TABLES WITH READ LOCK statement as the former keeps tables open and thus prevents the latter statement from doing flush.	16 years ago

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