Don't copy onDidLoadBlocks #trivial (#1123)

TextureGroup · Sep 17, 2018 · fa8da15 · fa8da15
1 parent bf8d268
commit fa8da15
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Showing 2 changed files with 17 additions and 3 deletions.
diff --git a/Source/ASDisplayNode.mm b/Source/ASDisplayNode.mm
@@ -568,8 +568,7 @@ - (void)_didLoad
   [self didLoad];
 
   __instanceLock__.lock();
-  NSArray *onDidLoadBlocks = [_onDidLoadBlocks copy];
-  _onDidLoadBlocks = nil;
+  let onDidLoadBlocks = ASTransferStrong(_onDidLoadBlocks);
   __instanceLock__.unlock();
 
   for (ASDisplayNodeDidLoadBlock block in onDidLoadBlocks) {

diff --git a/Source/Base/ASBaseDefines.h b/Source/Base/ASBaseDefines.h
@@ -7,7 +7,7 @@
 //  Licensed under Apache 2.0: http://www.apache.org/licenses/LICENSE-2.0
 //
 
-#import <Foundation/NSObjCRuntime.h>
+#import <Foundation/Foundation.h>
 
 #define AS_EXTERN FOUNDATION_EXTERN
 #define unowned __unsafe_unretained
@@ -229,3 +229,18 @@
   } \
   __result; \
 })
+
+/**
+ * Capture-and-clear a strong reference without the intervening retain/release pair.
+ *
+ * E.g. let localVar = ASTransferStrong(_myIvar);
+ * Post-condition: localVar has the strong value from _myIvar and _myIvar is nil.
+ * No retain/release is emitted when the optimizer is on.
+ */
+#define ASTransferStrong(lvalue) ({ \
+  CFTypeRef *__rawPtr = (CFTypeRef *)(void *)(&(lvalue)); \
+  CFTypeRef __cfValue = *__rawPtr; \
+  *__rawPtr = NULL; \
+  __typeof(lvalue) __result = (__bridge_transfer __typeof(lvalue))__cfValue; \
+  __result; \
+})