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Before this fix, the server could crash during shutdown, due to race conditions, that occured when killing the server. In particular, the performance schema instrumentation handle, PSI_server, and the performance schema itself would be cleaned up too soon, causing race conditions with a running kill server thread. The specifics of the race condition found are that: the main thread executing "PSI_server= NULL" can cause crashes in other threads still running, which are executing "if (PSI_server != NULL) PSI_server->xxx()" as part of the performance schema instrumentation. While the bug was reported for the kill server thread, in theory the same crash could happen with the signal thread, as found by code analysis. The correct fix would be to only shutdown the performance schema and set PSI_server to NULL after every other thread is guaranteed to be completed, including the kill_server_thread. However, due to the existing mysqld server design, this is not the case. See in particular bug number 56666. The work around used to fix this race condition is to simply not perform the call to shutdown_performance_schema() when the server exits, and to keep the PSI_server pointer unchanged. This will cause memory leaks to be reported by tools like valgrind, but no memory leak actually happen because the process is about to exit(). As a result, the file mysql-test/valgrind.supp has been updated to filter out these false positive messages. This code has been tested with running in a loop the following tests in parallel, which have been known to fail with race conditions in the past: - rpl_change_master - binlog_max_extension - events_restart - rpl_heartbeat_basic and no crash of test failure has been seen with the changed code. |
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| .. | ||
| collections | ||
| extra | ||
| include | ||
| lib | ||
| r | ||
| std_data | ||
| suite | ||
| t | ||
| CMakeLists.txt | ||
| Makefile.am | ||
| mtr.out-of-source | ||
| mysql-stress-test.pl | ||
| mysql-test-run.pl | ||
| purify.supp | ||
| README | ||
| README.gcov | ||
| README.stress | ||
| valgrind.supp | ||
This directory contains a test suite for the MySQL daemon. To run the currently existing test cases, simply execute ./mysql-test-run in this directory. It will fire up the newly built mysqld and test it. Note that you do not have to have to do "make install", and you could actually have a co-existing MySQL installation. The tests will not conflict with it. All tests must pass. If one or more of them fail on your system, please read the following manual section for instructions on how to report the problem: http://dev.mysql.com/doc/mysql/en/mysql-test-suite.html If you want to use an already running MySQL server for specific tests, use the --extern option to mysql-test-run. Please note that in this mode, the test suite expects you to provide the names of the tests to run. For example, here is the command to run the "alias" and "analyze" tests with an external server: mysql-test-run --extern alias analyze To match your setup, you might also need to provide --socket, --user, and other relevant options. With no test cases named on the command line, mysql-test-run falls back to the normal "non-extern" behavior. The reason for this is that some tests cannot run with an external server. You can create your own test cases. To create a test case, create a new file in the t subdirectory using a text editor. The file should have a .test extension. For example: xemacs t/test_case_name.test In the file, put a set of SQL statements that create some tables, load test data, and run some queries to manipulate it. We would appreciate it if you name your test tables t1, t2, t3 ... (to not conflict too much with existing tables). Your test should begin by dropping the tables you are going to create and end by dropping them again. This ensures that you can run the test over and over again. If you are using mysqltest commands (like result file names) in your test case, you should create the result file as follows: mysql-test-run --record test_case_name or mysqltest --record < t/test_case_name.test If you only have a simple test cases consisting of SQL statements and comments, you can create the test case in one of the following ways: mysql-test-run --record test_case_name mysql test < t/test_case_name.test > r/test_case_name.result mysqltest --record --record-file=r/test_case_name.result < t/test_case_name.test When this is done, take a look at r/test_case_name.result - If the result is incorrect, you have found a bug. In this case, you should edit the test result to the correct results so that we can verify that the bug is corrected in future releases. To submit your test case, put your .test file and .result file(s) into a tar.gz archive, add a README that explains the problem, ftp the archive to ftp://support.mysql.com/pub/mysql/secret/ and send a mail to bugs@lists.mysql.com