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bead24b7f3
Remove one of the major sources of race condiitons in mariadb-test. Normally, mariadb_close() sends COM_QUIT to the server and immediately disconnects. In mariadb-test it means the test can switch to another connection and sends queries to the server before the server even started parsing the COM_QUIT packet and these queries can see the connection as fully active, as it didn't reach dispatch_command yet. This is a major source of instability in tests and many - but not all, still less than a half - tests employ workarounds. The correct one is a pair count_sessions.inc/wait_until_count_sessions.inc. Also very popular was wait_until_disconnected.inc, which was completely useless, because it verifies that the connection is closed, and after disconnect it always is, it didn't verify whether the server processed COM_QUIT. Sadly the placebo was as widely used as the real thing. Let's fix this by making mariadb-test `disconnect` command _to wait_ for the server to confirm. This makes almost all workarounds redundant. In some cases count_sessions.inc/wait_until_count_sessions.inc is still needed, though, as only `disconnect` command is changed: * after external tools, like `exec $MYSQL` * after failed `connect` command * replication, after `STOP SLAVE` * Federated/CONNECT/SPIDER/etc after `DROP TABLE` and also in some XA tests, because an XA transaction is dissociated from the THD very late, after the server has closed the client connection. Collateral cleanups: fix comments, remove some redundant statements: * DROP IF EXISTS if nothing is known to exist * DROP table/view before DROP DATABASE * REVOKE privileges before DROP USER etc
47 lines
1.2 KiB
Plaintext
47 lines
1.2 KiB
Plaintext
--source include/have_innodb.inc
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CREATE TABLE t (
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`a` INT NOT NULL,
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PRIMARY KEY (`a`)
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) ENGINE=InnoDB;
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INSERT INTO t VALUES(10);
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INSERT INTO t VALUES(20);
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SET TRANSACTION ISOLATION LEVEL REPEATABLE READ;
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XA START '1';
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SELECT * FROM t WHERE a > 20 FOR UPDATE;
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# The following INSERT is necessary because trx_prepare() resets locks
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# only if there were modifications in transaction.
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INSERT INTO t VALUES(40);
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XA END '1';
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XA PREPARE '1';
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connect (con1,localhost,root);
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SET innodb_lock_wait_timeout=1;
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# The following INSERT must not be blocked if XA PREPARE released supremum lock
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INSERT INTO t VALUES(50);
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--connection default
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XA COMMIT '1';
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XA START '1';
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SELECT * FROM t WHERE a > 20 LOCK IN SHARE MODE;
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# The following INSERT is necessary because trx_prepare() resets locks
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# only if there were modifications in transaction.
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INSERT INTO t VALUES (5);
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XA END '1';
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XA PREPARE '1';
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--connection con1
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# The following INSERT must not be blocked if XA PREPARE released supremum lock
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INSERT INTO t VALUES (60);
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# The following INSERT must not be blocked if XA PREPARE released shared lock
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INSERT INTO t VALUES (30);
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--disconnect con1
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--connection default
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XA COMMIT '1';
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DROP TABLE t;
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