Commit a2370730 authored by unknown's avatar unknown
Browse files

Avoid possible race condition in accessing slave statistics 

during shutdown. (Bug #11796)


sql/sql_show.cc:
  Check that active_mi is not NULL before accessing its members.
parent 75c45caf

sql/sql_show.cc

+7 −4
Original line number Diff line number Diff line
@@ -1890,7 +1890,7 @@ int mysqld_show(THD *thd, const char *wild, show_var_st *variables, 
      case SHOW_SLAVE_RUNNING:

      {

	pthread_mutex_lock(&LOCK_active_mi);

	end= strmov(buff, (active_mi->slave_running &&

	end= strmov(buff, (active_mi && active_mi->slave_running &&

			   active_mi->rli.slave_running) ? "ON" : "OFF");

	pthread_mutex_unlock(&LOCK_active_mi);

	break;
@@ -1902,9 +1902,12 @@ int mysqld_show(THD *thd, const char *wild, show_var_st *variables, 
          SLAVE STATUS, and have the sum over all lines here.

        */

	pthread_mutex_lock(&LOCK_active_mi);

        if (active_mi)

        {

          pthread_mutex_lock(&active_mi->rli.data_lock);

          end= int10_to_str(active_mi->rli.retried_trans, buff, 10);

          pthread_mutex_unlock(&active_mi->rli.data_lock);

        }

	pthread_mutex_unlock(&LOCK_active_mi);

	break;

      }