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This bug is actually two bugs in one, one of which is CREATE TRIGGER under LOCK TABLES and the other is CREATE TRIGGER under LOCK TABLES simultaneous to a FLUSH TABLES WITH READ LOCK (global read lock). Both situations could lead to a server crash or deadlock. The first problem arises from the fact that when under LOCK TABLES, if the table is in the set of locked tables, the table is already open and it doesn't need to be reopened (not a placeholder). Also in this case, if the table is not write locked, a exclusive lock can't be acquired because of a possible deadlock with another thread also holding a (read) lock on the table. The second issue arises from the fact that one should never wait for a global read lock if it's holding any locked tables, because the global read lock is waiting for these tables and this leads to a circular wait deadlock. The solution for the first case is to check if the table is write locked and upgraded the write lock to a exclusive lock and fail otherwise for non write locked tables. Grabbin the exclusive lock in this case also means to ensure that the table is opened only by the calling thread. The second issue is partly fixed by not waiting for the global read lock if the thread is holding any locked tables. The second issue is only partly addressed in this patch because it turned out to be much wider and also affects other DDL statements. Reported as Bug#32395 |
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.. | ||
extra | ||
include | ||
lib | ||
misc | ||
ndb | ||
r | ||
std_data | ||
suite | ||
t | ||
create-test-result | ||
fix-result | ||
install_test_db.sh | ||
Makefile.am | ||
mysql-stress-test.pl | ||
mysql-test-run-shell.sh | ||
mysql-test-run.pl | ||
purify.supp | ||
README | ||
README.gcov | ||
README.stress | ||
resolve-stack | ||
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