mariadb/mysql-test/r/sp_sync.result

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Fixed Bug#11756013 (formerly known as bug#47870): BOGUS "THE TABLE MYSQL.PROC IS MISSING,..." There was a race condition between loading a stored routine (function/procedure/trigger) specified by fully qualified name SCHEMA_NAME.PROC_NAME and dropping the stored routine database. The problem was that there is a window for race condition when one server thread tries to load a stored routine being executed and the other thread tries to drop the stored routine schema. This condition race window exists in implementation of function mysql_change_db() called by db_load_routine() during loading of stored routine to cache. Function mysql_change_db() calls check_db_dir_existence() that might failed because specified database was dropped during concurrent execution of DROP SCHEMA statement. db_load_routine() calls mysql_change_db() with flag 'force_switch' set to 'true' value so when referenced db is not found then my_error() is not called and function mysql_change_db() returns ok. This shadows information about schema opening error in db_load_routine(). Then db_load_routine() makes attempt to parse stored routine that is failed. This makes to return error to sp_cache_routines_and_add_tables_aux() but since during error generation a call to my_error wasn't made and hence THD::main_da wasn't set we set the generic "mysql.proc table corrupt" error when running sp_cache_routines_and_add_tables_aux(). The fix is to install an error handler inside db_load_routine() for the mysql_op_change_db() call, and check later if the ER_BAD_DB_ERROR was caught.
2011-06-23 20:41:04 +07:00
Tests of synchronization of stored procedure execution.
SET DEBUG_SYNC= 'RESET';
#
# Bug #30977 Concurrent statement using stored function and
# DROP FUNCTION breaks SBR
#
# A stored routine could change after dispatch_command()
# but before a MDL lock is taken. This must be noticed and the
# sp cache flushed so the correct version can be loaded.
#
# Connection default
CREATE FUNCTION f1() RETURNS INT RETURN 1;
# Get f1 cached
SELECT f1();
f1()
1
# Then start executing it again...
SET DEBUG_SYNC= 'before_execute_sql_command SIGNAL before WAIT_FOR changed';
# Sending:
SELECT f1();
# Connection 2
SET DEBUG_SYNC= 'now WAIT_FOR before';
# ... but before f1 is locked, change it.
DROP FUNCTION f1;
CREATE FUNCTION f1() RETURNS INT RETURN 2;
SET DEBUG_SYNC= 'now SIGNAL changed';
# Connection default
# We should now get '2' and not '1'.
# Reaping: SELECT f1()
f1()
2
DROP FUNCTION f1;
SET DEBUG_SYNC= 'RESET';
#
# Field translation items must be cleared in case of back-offs
# for queries that use Information Schema tables. Otherwise
# memory allocated in fix_fields() for views may end up referring
# to freed memory.
#
DROP FUNCTION IF EXISTS f1;
# Connection default
CREATE FUNCTION f1() RETURNS INT RETURN 0;
# Connection con2
SET DEBUG_SYNC= 'after_wait_locked_pname SIGNAL locked WAIT_FOR issued';
# con2 will now have an x-lock on f1
# Sending:
ALTER FUNCTION f1 COMMENT 'comment';
# Connection default
SET DEBUG_SYNC= 'now WAIT_FOR locked';
# This query will block due to the x-lock on f1 and back-off
SHOW OPEN TABLES WHERE f1()=0;
# Connection con3
# Check that the IS query is blocked before releasing the x-lock
SET DEBUG_SYNC= 'now SIGNAL issued';
# Connection default
# Reaping: ALTER FUNCTION f1 COMMENT 'comment'
DROP FUNCTION f1;
SET DEBUG_SYNC= 'RESET';
#
# Bug #48246 assert in close_thread_table
#
Patch that changes approach to how we acquire metadata locks for DML statements and changes the way MDL locks are acquired/granted in contended case. Instead of backing-off when a lock conflict is encountered and waiting for it to go away before restarting open_tables() process we now wait for lock to be released without releasing any previously acquired locks. If conflicting lock goes away we resume opening tables. If waiting leads to a deadlock we try to resolve it by backing-off and restarting open_tables() immediately. As result both waiting for possibility to acquire and acquiring of a metadata lock now always happen within the same MDL API call. This has allowed to make release of a lock and granting it to the most appropriate pending request an atomic operation. Thanks to this it became possible to wake up during release of lock only those waiters which requests can be satisfied at the moment as well as wake up only one waiter in case when granting its request would prevent all other requests from being satisfied. This solves thundering herd problem which occured in cases when we were releasing some lock and woke up many waiters for SNRW or X locks (this was the issue in bug#52289 "performance regression for MyISAM in sysbench OLTP_RW test". This also allowed to implement more fair (FIFO) scheduling among waiters with the same priority. It also opens the door for introducing new types of requests for metadata locks such as low-prio SNRW lock which is necessary in order to support LOCK TABLES LOW_PRIORITY WRITE. Notice that after this sometimes can report ER_LOCK_DEADLOCK error in cases in which it has not happened before. Particularly we will always report this error if waiting for conflicting lock has happened in the middle of transaction and resulted in a deadlock. Before this patch the error was not reported if deadlock could have been resolved by backing off all metadata locks acquired by the current statement.
2010-06-07 11:06:55 +04:00
CREATE TABLE t0 (b INTEGER);
CREATE TABLE t1 (a INTEGER);
CREATE FUNCTION f1(b INTEGER) RETURNS INTEGER RETURN 1;
Patch that changes approach to how we acquire metadata locks for DML statements and changes the way MDL locks are acquired/granted in contended case. Instead of backing-off when a lock conflict is encountered and waiting for it to go away before restarting open_tables() process we now wait for lock to be released without releasing any previously acquired locks. If conflicting lock goes away we resume opening tables. If waiting leads to a deadlock we try to resolve it by backing-off and restarting open_tables() immediately. As result both waiting for possibility to acquire and acquiring of a metadata lock now always happen within the same MDL API call. This has allowed to make release of a lock and granting it to the most appropriate pending request an atomic operation. Thanks to this it became possible to wake up during release of lock only those waiters which requests can be satisfied at the moment as well as wake up only one waiter in case when granting its request would prevent all other requests from being satisfied. This solves thundering herd problem which occured in cases when we were releasing some lock and woke up many waiters for SNRW or X locks (this was the issue in bug#52289 "performance regression for MyISAM in sysbench OLTP_RW test". This also allowed to implement more fair (FIFO) scheduling among waiters with the same priority. It also opens the door for introducing new types of requests for metadata locks such as low-prio SNRW lock which is necessary in order to support LOCK TABLES LOW_PRIORITY WRITE. Notice that after this sometimes can report ER_LOCK_DEADLOCK error in cases in which it has not happened before. Particularly we will always report this error if waiting for conflicting lock has happened in the middle of transaction and resulted in a deadlock. Before this patch the error was not reported if deadlock could have been resolved by backing off all metadata locks acquired by the current statement.
2010-06-07 11:06:55 +04:00
CREATE PROCEDURE p1() SELECT COUNT(f1(a)) FROM t1, t0;
INSERT INTO t0 VALUES(1);
INSERT INTO t1 VALUES(1), (2);
# Connection 2
CALL p1();
COUNT(f1(a))
2
Patch that changes approach to how we acquire metadata locks for DML statements and changes the way MDL locks are acquired/granted in contended case. Instead of backing-off when a lock conflict is encountered and waiting for it to go away before restarting open_tables() process we now wait for lock to be released without releasing any previously acquired locks. If conflicting lock goes away we resume opening tables. If waiting leads to a deadlock we try to resolve it by backing-off and restarting open_tables() immediately. As result both waiting for possibility to acquire and acquiring of a metadata lock now always happen within the same MDL API call. This has allowed to make release of a lock and granting it to the most appropriate pending request an atomic operation. Thanks to this it became possible to wake up during release of lock only those waiters which requests can be satisfied at the moment as well as wake up only one waiter in case when granting its request would prevent all other requests from being satisfied. This solves thundering herd problem which occured in cases when we were releasing some lock and woke up many waiters for SNRW or X locks (this was the issue in bug#52289 "performance regression for MyISAM in sysbench OLTP_RW test". This also allowed to implement more fair (FIFO) scheduling among waiters with the same priority. It also opens the door for introducing new types of requests for metadata locks such as low-prio SNRW lock which is necessary in order to support LOCK TABLES LOW_PRIORITY WRITE. Notice that after this sometimes can report ER_LOCK_DEADLOCK error in cases in which it has not happened before. Particularly we will always report this error if waiting for conflicting lock has happened in the middle of transaction and resulted in a deadlock. Before this patch the error was not reported if deadlock could have been resolved by backing off all metadata locks acquired by the current statement.
2010-06-07 11:06:55 +04:00
SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL locked_t1 WAIT_FOR go_for_t0';
# This call used to cause an assertion. MDL deadlock with upcoming
# LOCK TABLES statement will cause back-off and retry.
# A variable indicating if a prelocking list exists, used to be not
# reset properly causing an eventual assert.
# Sending:
CALL p1();
# Connection default
Patch that changes approach to how we acquire metadata locks for DML statements and changes the way MDL locks are acquired/granted in contended case. Instead of backing-off when a lock conflict is encountered and waiting for it to go away before restarting open_tables() process we now wait for lock to be released without releasing any previously acquired locks. If conflicting lock goes away we resume opening tables. If waiting leads to a deadlock we try to resolve it by backing-off and restarting open_tables() immediately. As result both waiting for possibility to acquire and acquiring of a metadata lock now always happen within the same MDL API call. This has allowed to make release of a lock and granting it to the most appropriate pending request an atomic operation. Thanks to this it became possible to wake up during release of lock only those waiters which requests can be satisfied at the moment as well as wake up only one waiter in case when granting its request would prevent all other requests from being satisfied. This solves thundering herd problem which occured in cases when we were releasing some lock and woke up many waiters for SNRW or X locks (this was the issue in bug#52289 "performance regression for MyISAM in sysbench OLTP_RW test". This also allowed to implement more fair (FIFO) scheduling among waiters with the same priority. It also opens the door for introducing new types of requests for metadata locks such as low-prio SNRW lock which is necessary in order to support LOCK TABLES LOW_PRIORITY WRITE. Notice that after this sometimes can report ER_LOCK_DEADLOCK error in cases in which it has not happened before. Particularly we will always report this error if waiting for conflicting lock has happened in the middle of transaction and resulted in a deadlock. Before this patch the error was not reported if deadlock could have been resolved by backing off all metadata locks acquired by the current statement.
2010-06-07 11:06:55 +04:00
SET DEBUG_SYNC= 'now WAIT_FOR locked_t1';
# Issue LOCK TABLES statement which will enter in MDL deadlock
# with CALL statement and as result will cause it to perform
# back-off and retry.
SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL go_for_t0';
LOCK TABLES t0 WRITE, t1 WRITE;
UNLOCK TABLES;
# Connection 2
# Reaping: CALL p1()
COUNT(f1(a))
2
# Connection default
DROP PROCEDURE p1;
DROP FUNCTION f1;
Patch that changes approach to how we acquire metadata locks for DML statements and changes the way MDL locks are acquired/granted in contended case. Instead of backing-off when a lock conflict is encountered and waiting for it to go away before restarting open_tables() process we now wait for lock to be released without releasing any previously acquired locks. If conflicting lock goes away we resume opening tables. If waiting leads to a deadlock we try to resolve it by backing-off and restarting open_tables() immediately. As result both waiting for possibility to acquire and acquiring of a metadata lock now always happen within the same MDL API call. This has allowed to make release of a lock and granting it to the most appropriate pending request an atomic operation. Thanks to this it became possible to wake up during release of lock only those waiters which requests can be satisfied at the moment as well as wake up only one waiter in case when granting its request would prevent all other requests from being satisfied. This solves thundering herd problem which occured in cases when we were releasing some lock and woke up many waiters for SNRW or X locks (this was the issue in bug#52289 "performance regression for MyISAM in sysbench OLTP_RW test". This also allowed to implement more fair (FIFO) scheduling among waiters with the same priority. It also opens the door for introducing new types of requests for metadata locks such as low-prio SNRW lock which is necessary in order to support LOCK TABLES LOW_PRIORITY WRITE. Notice that after this sometimes can report ER_LOCK_DEADLOCK error in cases in which it has not happened before. Particularly we will always report this error if waiting for conflicting lock has happened in the middle of transaction and resulted in a deadlock. Before this patch the error was not reported if deadlock could have been resolved by backing off all metadata locks acquired by the current statement.
2010-06-07 11:06:55 +04:00
DROP TABLES t0, t1;
Fixed Bug#11756013 (formerly known as bug#47870): BOGUS "THE TABLE MYSQL.PROC IS MISSING,..." There was a race condition between loading a stored routine (function/procedure/trigger) specified by fully qualified name SCHEMA_NAME.PROC_NAME and dropping the stored routine database. The problem was that there is a window for race condition when one server thread tries to load a stored routine being executed and the other thread tries to drop the stored routine schema. This condition race window exists in implementation of function mysql_change_db() called by db_load_routine() during loading of stored routine to cache. Function mysql_change_db() calls check_db_dir_existence() that might failed because specified database was dropped during concurrent execution of DROP SCHEMA statement. db_load_routine() calls mysql_change_db() with flag 'force_switch' set to 'true' value so when referenced db is not found then my_error() is not called and function mysql_change_db() returns ok. This shadows information about schema opening error in db_load_routine(). Then db_load_routine() makes attempt to parse stored routine that is failed. This makes to return error to sp_cache_routines_and_add_tables_aux() but since during error generation a call to my_error wasn't made and hence THD::main_da wasn't set we set the generic "mysql.proc table corrupt" error when running sp_cache_routines_and_add_tables_aux(). The fix is to install an error handler inside db_load_routine() for the mysql_op_change_db() call, and check later if the ER_BAD_DB_ERROR was caught.
2011-06-23 20:41:04 +07:00
#
# test for bug#11756013
#
DROP SCHEMA IF EXISTS s1;
CREATE SCHEMA s1;
CREATE PROCEDURE s1.p1() BEGIN END;
SET DEBUG_SYNC='before_db_dir_check SIGNAL check_db WAIT_FOR dropped_schema';
CALL s1.p1;
SET DEBUG_SYNC='now WAIT_FOR check_db';
DROP SCHEMA s1;
SET DEBUG_SYNC='now SIGNAL dropped_schema';
ERROR 42000: Unknown database 's1'
SET DEBUG_SYNC = 'RESET';