Trustin Lee 309ee68c21 Fix a race condition in DefaultPromise
.. which occurs when a user adds a listener from different threads after the promise is done and the notifications for the listeners, that were added before the promise is done, is in progress.  For instance:

   Thread-1: p.addListener(listenerA);
   Thread-1: p.setSuccess(null);
   Thread-2: p.addListener(listenerB);
   Thread-2: p.executor.execute(taskNotifyListenerB);
   Thread-1: p.executor.execute(taskNotifyListenerA);

taskNotifyListenerB should not really notify listenerB until taskNotifyListenerA is finished.

To fix this issue:

- Change the semantic of (listeners == null) to determine if the early
  listeners [1] were notified
- If a late listener is added before the early listeners are notified,
  the notification of the late listener is deferred until the early
  listeners are notified (i.e. until listeners == null)
- The late listeners with deferred notifications are stored in a lazily
  instantiated queue to preserve ordering, and then are notified once
  the early listeners are notified.

[1] the listeners that were added before the promise is done
[2] the listeners that were added after the promise is done
2014-02-06 22:05:24 -08:00
..
2013-10-25 21:04:10 +09:00
2013-07-20 08:01:14 +02:00
2012-06-04 13:31:44 -07:00
2013-06-10 16:38:57 +09:00
2013-12-05 00:51:39 +09:00
2012-12-26 13:50:01 +09:00
2012-06-04 13:31:44 -07:00