--source include/have_innodb.inc --source include/have_debug_sync.inc --source include/count_sessions.inc --disable_query_log call mtr.add_suppression("InnoDB: Transaction was aborted due to "); --enable_query_log # Purge can cause deadlock in the test, requesting page's RW_X_LATCH for trx # ids reseting, after trx 2 acqured RW_S_LATCH and suspended in debug sync point # lock_trx_handle_wait_enter, waiting for upd_cont signal, which must be # emitted after the last SELECT in this test. The last SELECT will hang waiting # for purge RW_X_LATCH releasing, and trx 2 will be rolled back by timeout. # There is deadlock_report_before_lock_releasing sync point in # Deadlock::report(), which is waiting for sel_cont signal under # lock_sys_t lock. The signal must be issued after "UPDATE t SET b = 100" # rollback, and that rollback is executing undo record, which is blocked on # dict_sys latch request. dict_sys is locked by the thread of statistics # update(dict_stats_save()), and during that update lock_sys lock is requested, # and can't be acquired as Deadlock::report() holds it. We have to disable # statistics update to make the test stable. CREATE TABLE t (a int PRIMARY KEY, b int) engine = InnoDB STATS_PERSISTENT=0; CREATE TABLE t2 (a int PRIMARY KEY) engine = InnoDB STATS_PERSISTENT=0; INSERT INTO t VALUES (10, 10), (20, 20), (30, 30); INSERT INTO t2 VALUES (10), (20), (30); BEGIN; # trx 1 # The following update is necessary to increase the transaction weight, which is # calculated as the number of locks + the number of undo records during deadlock # report. Victim's transaction should have minimum weight. We need trx 2 to be # choosen as victim, that's why we need to increase the current transaction # weight. UPDATE t2 SET a = a + 100; SELECT * FROM t WHERE a = 20 FOR UPDATE; --connect(con_2,localhost,root,,) SET innodb_snapshot_isolation=OFF; # RC is necessary to do semi-consistent read SET TRANSACTION ISOLATION LEVEL READ COMMITTED; # It will be hit on trying to lock (20,20). SET DEBUG_SYNC = 'lock_trx_handle_wait_enter SIGNAL upd_locked WAIT_FOR upd_cont'; SET DEBUG_SYNC = 'trx_t_release_locks_enter SIGNAL sel_cont WAIT_FOR upd_cont_2'; BEGIN; # trx 2 # We must not modify primary key fields to cause rr_sequential() read record # function choosing in mysql_update(), i.e. both query_plan.using_filesort and # query_plan.using_io_buffer must be false during init_read_record() call. # The following UPDATE will be chosen as deadlock victim and rolled back. --send UPDATE t SET b = 100 --connection default SET DEBUG_SYNC="now WAIT_FOR upd_locked"; SET DEBUG_SYNC="deadlock_report_before_lock_releasing SIGNAL upd_cont WAIT_FOR sel_cont"; SET DEBUG_SYNC="lock_wait_before_suspend SIGNAL sel_before_suspend"; # If the bug is not fixed, the following SELECT will crash, as the above UPDATE # will reset trx->lock.wait_thr during rollback --send SELECT * FROM t WHERE a = 10 FOR UPDATE; --connect(con_3,localhost,root,,) SET DEBUG_SYNC="now WAIT_FOR sel_before_suspend"; SET DEBUG_SYNC="now SIGNAL upd_cont_2"; --disconnect con_3 --connection con_2 --error ER_LOCK_DEADLOCK --reap --disconnect con_2 --connection default --reap SET DEBUG_SYNC = 'RESET'; DROP TABLE t; DROP TABLE t2; --source include/wait_until_count_sessions.inc