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Re: [Commits] Rev 4066: MDEV-5089 - possible deadlocks between rwlocks and mutexes
On Feb 13, Sergey Vojtovich wrote:
> revno: 4066
> revision-id: svoj@xxxxxxxxxxx-20140213074049-70zbqa98y95sfpox
> parent: sanja@xxxxxxxxxxxx-20140212150705-e1tfabmhjggqws7q
> committer: Sergey Vojtovich <svoj@xxxxxxxxxxx>
> branch nick: 5.5
> timestamp: Thu 2014-02-13 11:40:49 +0400
> MDEV-5089 - possible deadlocks between rwlocks and mutexes
> Pre-MDL versions had direct relationship between LOCK_open and
> LOCK_global_system_variables, e.g.:
> intern_sys_var_ptr // locks LOCK_global_system_variable
> mysql_create_table_no_lock // locks LOCK_open
> With MDL this relationship was removed, but mutex order was still
> recorded. In fact there is indirect relationship between LOCK_open
> and LOCK_global_system_variables via rwlocks in reverse order.
> Removed LOCK_open and LOCK_global_system_variables order recording,
> instead assert that LOCK_open is never held in intern_sys_var_ptr().
> This solves only one of many problems detected with MDEV-5089.
Looks good, thanks!
ok to push!