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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
35 lines
686 B
Text
35 lines
686 B
Text
connect con1,localhost,root,,;
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connect con2,localhost,root,,;
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connection con1;
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disconnect con1;
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connection con2;
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CREATE TABLE t1 (n INT);
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INSERT INTO t1 VALUES (1),(2),(3);
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SELECT * FROM t1;
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n
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1
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2
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3
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DROP TABLE t1;
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connection default;
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disconnect con2;
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connection default;
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SELECT GET_LOCK("dangling", 0);
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GET_LOCK("dangling", 0)
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1
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connect con1, localhost, root,,;
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connection con1;
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SELECT GET_LOCK('dangling', 3600);;
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connection default;
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disconnect con1;
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connect con1, localhost, root,,;
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SELECT GET_LOCK('dangling', 3600);;
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connection default;
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SELECT RELEASE_LOCK('dangling');
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RELEASE_LOCK('dangling')
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1
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connection con1;
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GET_LOCK('dangling', 3600)
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1
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connection default;
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disconnect con1;
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