Nirbhay Choubey <nirbhay@mariadb.com> writes:

revno: 3902 revision-id: nirbhay@mariadb.com-20141123163533-9ov1yirj26cur301 parent: nirbhay@mariadb.com-20141119183337-n5spskf54beqbhif committer: Nirbhay Choubey <nirbhay@mariadb.com> branch nick: maria-10.0-galera timestamp: Sun 2014-11-23 11:35:33 -0500 message: MDEV-7123: MariaDB 10.0.14 Galera node shutdown with signal 11

wsrep-patch uses same connection name for constructing Master_info objects. As a result all existing wsrep Master_info objects refer to same rpl_filter object. This could lead to race when multiple threads try to destruct/delete Master_info object, as they would all try to delete the same relay_log object. Fixed by adding a mutex to protect the critical section.

The patch is ok. But please consider the following points, and act on them or not as you see fit: 1. You are introducing a mutex lock/unlock in a general data structure used in a couple of places (looks like keycaches and rpl_filters?). Did you consider the performance impact of this? When will the additional locking/unlocking take place? If it only happens in less often used operations (like re-configuring replication filters or key caches?), then extra locking is not an issue. If it happens often, like once per query or something like that, it would probably be best to find a solution with less performance impact. (mutex lock and unlock are quite expensive even if not contended). 2. Consider using explicit mysql_mutex_lock() and mysql_mutex_unlock() calls rather than introducing extra lock()/unlock() methods. The extra methods are needless abtractions that make it harder to understand exactly what is happening wrt. locking. 3. Did you consider if a test case could be made for the originally reported bug? We used to have a rule that any bug fix must include a test case that reproduces the bug fixed (ie. the test case must fail before the patch). Not a hard rule (a few bugs can be extremely hard to write mtr testcases for), but a good rule nevertheless. But maybe this rule has been dropped, now that the focus is on quantity of Jira tickes closed rather than quality. - Kristian.