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Bug #42147 Concurrent DML and LOCK TABLE ... READ for InnoDB table cause warnings in errlog Concurrent execution of LOCK TABLES ... READ statement and DML statements affecting the same InnoDB table on debug builds of MySQL server might lead to "Found lock of type 6 that is write and read locked" warnings appearing in error log. The problem is that the table-level locking code allows a thread to acquire TL_READ_NO_INSERT lock on a table even if there is another thread which holds TL_WRITE_ALLOW_WRITE lock on the same table. At the same time, the locking code assumes that that such locks are incompatible (for example, see check_locks()). This doesn't lead to any problems other than warnings in error log for debug builds of server since for InnoDB tables TL_READ_NO_INSERT type of lock is only used for LOCK TABLES and for this statement InnoDB also performs its own table-level locking. Unfortunately, the table lock compatibility matrix cannot be updated to disallow TL_READ_NO_INSERT when another thread holds TL_WRITE_ALLOW_WRITE without causing starvation of LOCK TABLE READ in InnoDB under high write load. This patch therefore contains no code changes. The issue will be fixed later when LOCK TABLE READ has been updated to not use table locks. This bug will therefore be marked as "To be fixed later". Code comment in thr_lock.c expanded to clarify the issue and a test case based on the bug description added to innodb_mysql_lock.test. Note that a global suppression rule has been added to both MTR v1 and v2 for the "Found lock of type 6 that is write and read locked" warning. These suppression rules must be removed once this bug is properly fixed.
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