From d1054d6ed98a3fc68ab078b3d6af360ae09f21d2 Mon Sep 17 00:00:00 2001
From: Michael Schneider <mischneider1@gmail.com>
Date: Thu, 5 May 2016 20:24:26 -0700
Subject: [PATCH] Move from ASSentinel to a atomic int

---
 AsyncDisplayKit/ASDisplayNode.mm                | 14 +++-----------
 AsyncDisplayKit/Private/ASDisplayNodeInternal.h |  2 +-
 2 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/AsyncDisplayKit/ASDisplayNode.mm b/AsyncDisplayKit/ASDisplayNode.mm
index 6d8515d74f..6e54a450c1 100644
--- a/AsyncDisplayKit/ASDisplayNode.mm
+++ b/AsyncDisplayKit/ASDisplayNode.mm
@@ -373,7 +373,6 @@ static ASDisplayNodeMethodOverrides GetASDisplayNodeMethodOverrides(Class c)
   _pendingViewState = nil;
 
   _displaySentinel = nil;
-  _transitionSentinel = nil;
 
   _pendingDisplayNodes = nil;
 }
@@ -825,11 +824,8 @@ static ASDisplayNodeMethodOverrides GetASDisplayNodeMethodOverrides(Class c)
 {
   ASDN::MutexLocker l(_propertyLock);
   _transitionInProgress = YES;
-    
-  if (!_transitionSentinel) {
-    _transitionSentinel = [[ASSentinel alloc] init];
-  }
-  return [_transitionSentinel increment];
+  _transitionID = OSAtomicAdd32(1, &_transitionID);
+  return _transitionID;
 }
 
 - (void)_finishOrCancelTransition
@@ -841,11 +837,7 @@ static ASDisplayNodeMethodOverrides GetASDisplayNodeMethodOverrides(Class c)
 - (BOOL)_shouldAbortTransitionWithID:(int32_t)transitionID
 {
   ASDN::MutexLocker l(_propertyLock);
-  if (_transitionInProgress) {
-    return _transitionSentinel == nil || transitionID != _transitionSentinel.value;
-  }
-  
-  return YES;
+  return (!_transitionInProgress || _transitionID != transitionID);
 }
 
 - (void)animateLayoutTransition:(id<ASContextTransitioning>)context
diff --git a/AsyncDisplayKit/Private/ASDisplayNodeInternal.h b/AsyncDisplayKit/Private/ASDisplayNodeInternal.h
index b4668ac613..ca11a8746a 100644
--- a/AsyncDisplayKit/Private/ASDisplayNodeInternal.h
+++ b/AsyncDisplayKit/Private/ASDisplayNodeInternal.h
@@ -94,7 +94,7 @@ FOUNDATION_EXPORT NSString * const ASRenderingEngineDidDisplayNodesScheduledBefo
 
   ASSentinel *_displaySentinel;
 
-  ASSentinel *_transitionSentinel;
+  int32_t _transitionID;
   BOOL _transitionInProgress;
 
   // This is the desired contentsScale, not the scale at which the layer's contents should be displayed