Commit 88f55bf8 authored by unknown's avatar unknown
Browse files

BUG#23312 - server hangs 'closing tables' with insert delayed,flush 

            tables,alter table
Deadlock could happen if there are delayed insert + flush tables + alter table
running concurrently.

This is fixed by removing a redundant mutex lock when killing a delayed thread.


sql/sql_insert.cc:
  Removed redundant delayed thread mutex lock, that could result in a deadlock.
  LOCK_delayed_insert is sufficient to be sure that no other thread frees delayed
  handler.
parent 2576c4c0

sql/sql_insert.cc

+0 −3
Original line number Diff line number Diff line
@@ -1181,8 +1181,6 @@ void kill_delayed_threads(void) 
  delayed_insert *tmp;

  while ((tmp=it++))

  {

    /* Ensure that the thread doesn't kill itself while we are looking at it */

    pthread_mutex_lock(&tmp->mutex);

    tmp->thd.killed=1;

    if (tmp->thd.mysys_var)

    {
@@ -1201,7 +1199,6 @@ void kill_delayed_threads(void) 
      }

      pthread_mutex_unlock(&tmp->thd.mysys_var->mutex);

    }

    pthread_mutex_unlock(&tmp->mutex);

  }

  VOID(pthread_mutex_unlock(&LOCK_delayed_insert)); // For unlink from list

}