Method wakeup_subsequent_commits2

sql/sql_class.cc:8698–8734

*/

void
wait_for_commit::wakeup_subsequent_commits2(int wakeup_error)
{
  wait_for_commit *waiter;

  if (unlikely(wakeup_blocked))
    return;

  mysql_mutex_lock(&LOCK_wait_commit);
  wakeup_subsequent_commits_running= true;
  waiter= subsequent_commits_list;
  subsequent_commits_list= NULL;
  mysql_mutex_unlock(&LOCK_wait_commit);

  while (waiter)
  {
    /*
      Important: we must grab the next pointer before waking up the waiter;
      once the wakeup is done, the field could be invalidated at any time.
    */
    wait_for_commit *next= waiter->next_subsequent_commit;
    waiter->wakeup(wakeup_error);
    waiter= next;
  }

  /*
    We need a full memory barrier between walking the list above, and clearing
    the flag wakeup_subsequent_commits_running below. This barrier is needed
    to ensure that no other thread will start to modify the list pointers
    before we are done traversing the list.

    But wait_for_commit::wakeup() does a full memory barrier already (it locks
    a mutex), so no extra explicit barrier is needed here.
  */
  wakeup_subsequent_commits_running= false;
  DBUG_EXECUTE_IF("inject_wakeup_subsequent_commits_sleep", my_sleep(21000););
}


/* Cancel a previously registered wait for another THD to commit before us. */