Reuse interface state delegates when calling out #trivial (#1099)

* Reuse interface state delegates when calling out instead of always copying
TextureGroup · Sep 6, 2018 · 395fbd1 · 395fbd1
1 parent 6b0d57e
commit 395fbd1
Show file tree

Hide file tree

Showing 2 changed files with 10 additions and 1 deletion.
diff --git a/Source/ASDisplayNode.mm b/Source/ASDisplayNode.mm
@@ -454,7 +454,10 @@ - (void)dealloc
 
 #define ASDisplayNodeCallInterfaceStateDelegates(method) \
     __instanceLock__.lock(); \
-    NSHashTable *delegates = [_interfaceStateDelegates copy]; \
+    NSHashTable *delegates = _copiedInterfaceStateDelegates; \
+    if (!delegates) { \
+      delegates = _copiedInterfaceStateDelegates = [_interfaceStateDelegates copy]; \
+    } \
     __instanceLock__.unlock(); \
     for (id <ASInterfaceStateDelegate> delegate in delegates) { \
       if ([delegate respondsToSelector:@selector(method)]) { \
@@ -3238,12 +3241,14 @@ - (void)addInterfaceStateDelegate:(id <ASInterfaceStateDelegate>)interfaceStateD
   if (_interfaceStateDelegates == nil) {
     _interfaceStateDelegates = [NSHashTable weakObjectsHashTable];
   }
+  _copiedInterfaceStateDelegates = nil;
   [_interfaceStateDelegates addObject:interfaceStateDelegate];
 }
 
 - (void)removeInterfaceStateDelegate:(id <ASInterfaceStateDelegate>)interfaceStateDelegate
 {
   ASDN::MutexLocker l(__instanceLock__);
+  _copiedInterfaceStateDelegates = nil;
   [_interfaceStateDelegates removeObject:interfaceStateDelegate];
 }
 

diff --git a/Source/Private/ASDisplayNodeInternal.h b/Source/Private/ASDisplayNodeInternal.h
@@ -249,6 +249,10 @@ AS_EXTERN NSString * const ASRenderingEngineDidDisplayNodesScheduledBeforeTimest
 #endif
 
   NSHashTable <id <ASInterfaceStateDelegate>> *_interfaceStateDelegates;
+
+  // never mutated, used to enumerate delegates outside of lock.
+  // set to nil when mutating _interfaceStateDelegates.
+  NSHashTable <id <ASInterfaceStateDelegate>> *_copiedInterfaceStateDelegates;
 }
 
 + (void)scheduleNodeForRecursiveDisplay:(ASDisplayNode *)node;