bk commit into 5.0 tree (msvensson:1.2142) BUG#19938

[msvensson]

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ChangeSet
  1.2142 06/05/23 16:20:03 msvensson@neptunus.(none) +1 -0
  Bug #19938  	Valgrind error (race) in handle_slave_sql()

  sql/slave.cc
    1.268 06/05/23 16:19:59 msvensson@neptunus.(none) +8 -1
    Read rli->events_till_abort to a temporary variable before unlocking the mutex

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	msvensson
# Host:	neptunus.(none)
# Root:	/home/msvensson/mysql/mysql-5.0

--- 1.267/sql/slave.cc	2006-05-23 16:14:44 +02:00
+++ 1.268/sql/slave.cc	2006-05-23 16:19:59 +02:00
@@ -3949,10 +3949,17 @@
   delete thd;
   pthread_mutex_unlock(&LOCK_thread_count);
   pthread_cond_broadcast(&rli->stop_cond);
+
+  /*
+    Bug #19938 Valgrind error (race) in handle_slave_sql()
+    Read the value of rli->event_till_abort before releasing the mutex
+  */
+  const int eta= rli->events_till_abort;
+
   // tell the world we are done
   pthread_mutex_unlock(&rli->run_lock);
 #ifndef DBUG_OFF // TODO: reconsider the code below
-  if (abort_slave_event_count && !rli->events_till_abort)
+  if (abort_slave_event_count && !eta)
     goto slave_begin;
 #endif  
   my_thread_end();