refactor the cycle finder into a few additional functions for better …

…clarity, and stop leaking all the CF objects
leereilly · Jun 3, 2012 · dbc1ac0 · dbc1ac0
1 parent a17c615
commit dbc1ac0
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Showing 3 changed files with 54 additions and 22 deletions.
diff --git a/Circle/CircleSimpleCycleFinder.h b/Circle/CircleSimpleCycleFinder.h
@@ -9,4 +9,11 @@
 #import <Foundation/Foundation.h>
 
 
-void CircleSimpleSearchCycle(id obj);
+struct CircleSearchResults
+{
+    BOOL isUnclaimedCycle;
+    CFSetRef incomingReferences;
+};
+
+struct CircleSearchResults CircleSimpleSearchCycle(id obj);
+void CircleZeroReferences(CFSetRef references);
diff --git a/Circle/CircleSimpleCycleFinder.m b/Circle/CircleSimpleCycleFinder.m
@@ -43,7 +43,7 @@ - (void)dealloc
 
 @end
 
-void CircleSimpleSearchCycle(id obj)
+static CFDictionaryRef CopyInfosForReferents(id obj)
 {
     CFMutableDictionaryRef searchedObjs = CFDictionaryCreateMutable(NULL, 0, NULL, &kCFTypeDictionaryValueCallBacks);
     CFMutableArrayRef toSearchObjs = CFArrayCreateMutable(NULL, 0, NULL);
@@ -78,26 +78,35 @@ void CircleSimpleSearchCycle(id obj)
             }
         }
     }
+    CFRelease(toSearchObjs);
 
-    _CircleObjectInfo *info = (__bridge _CircleObjectInfo *)CFDictionaryGetValue(searchedObjs, (__bridge void *)obj);
+    return searchedObjs;
+}
+
+struct CircleSearchResults CircleSimpleSearchCycle(id obj)
+{
+    CFDictionaryRef infos = CopyInfosForReferents(obj);
+
+    _CircleObjectInfo *info = (__bridge _CircleObjectInfo *)CFDictionaryGetValue(infos, (__bridge void *)obj);
     CFSetRef incomingReferences = [info incomingReferences];
     NSUInteger retainCount = CFGetRetainCount((__bridge CFTypeRef)obj);
     LOG(@"%@ retain count is %lu, scanned incoming references are %@", obj, retainCount, CFBridgingRelease(CFCopyDescription(incomingReferences)));
 
-    CFArrayRemoveAllValues(toSearchObjs);
+    CFMutableArrayRef toSearchObjs = CFArrayCreateMutable(NULL, 0, NULL);
     CFArrayAppendValue(toSearchObjs, (__bridge void*)obj);
 
     CFMutableSetRef didSearchObjs = CFSetCreateMutable(NULL, 0, NULL);
 
     BOOL foundExternallyRetained = NO;
 
+    CFIndex count;
     while((count = CFArrayGetCount(toSearchObjs)) > 0)
     {
         void *cycleObj = (void *)CFArrayGetValueAtIndex(toSearchObjs, count - 1);
         CFArrayRemoveValueAtIndex(toSearchObjs, count - 1);
         CFSetAddValue(didSearchObjs, cycleObj);
 
-        _CircleObjectInfo *info = (__bridge _CircleObjectInfo *)CFDictionaryGetValue(searchedObjs, cycleObj);
+        _CircleObjectInfo *info = (__bridge _CircleObjectInfo *)CFDictionaryGetValue(infos, cycleObj);
         CFSetRef referencesCF = [info incomingReferences];
         CFIndex referencesCount = CFSetGetCount(referencesCF);
 
@@ -127,19 +136,29 @@ void CircleSimpleSearchCycle(id obj)
 
     LOG(@"foundExternallyRetained is %d", foundExternallyRetained);
 
-    if(!foundExternallyRetained)
+    struct CircleSearchResults results;
+    results.isUnclaimedCycle = !foundExternallyRetained;
+    results.incomingReferences = CFRetain(incomingReferences);
+
+    CFRelease(infos);
+    CFRelease(toSearchObjs);
+    CFRelease(didSearchObjs);
+
+    return results;
+}
+
+void CircleZeroReferences(CFSetRef references)
+{
+    NSUInteger incomingReferencesCount = CFSetGetCount(references);
+
+    const void *locations[incomingReferencesCount];
+    CFSetGetValues(references, locations);
+    for(unsigned i = 0; i < incomingReferencesCount; i++)
     {
-        NSUInteger incomingReferencesCount = CFSetGetCount(incomingReferences);
-
-        const void *locations[incomingReferencesCount];
-        CFSetGetValues(incomingReferences, locations);
-        for(unsigned i = 0; i < incomingReferencesCount; i++)
-        {
-            void **reference = (void **)locations[i];
-            void *target = *reference;
-            LOG(@"Zeroing reference %p to %p", reference, target);
-            *reference = NULL;
-            CFRelease(target);
-        }
+        void **reference = (void **)locations[i];
+        void *target = *reference;
+        LOG(@"Zeroing reference %p to %p", reference, target);
+        *reference = NULL;
+        CFRelease(target);
     }
 }
diff --git a/Circle/MAAppDelegate.m b/Circle/MAAppDelegate.m
@@ -88,7 +88,10 @@ - (void)applicationDidFinishLaunching:(NSNotification *)aNotification
             [c setPtr: a];
             weakObj = a;
         }
-        CircleSimpleSearchCycle(weakObj);
+        struct CircleSearchResults results = CircleSimpleSearchCycle(weakObj);
+        if(results.isUnclaimedCycle)
+            CircleZeroReferences(results.incomingReferences);
+        CFRelease(results.incomingReferences);
     }
     NSLog(@"After collecting, weak object is %@", weakObj);
 
@@ -105,11 +108,14 @@ - (void)applicationDidFinishLaunching:(NSNotification *)aNotification
             weakObj = a;
 
             self->strong = b;
-            NSLog(@"Before collecting, chaining gives", [self->strong ptr]);
+            NSLog(@"Before collecting, chaining gives %@", [self->strong ptr]);
         }
-        CircleSimpleSearchCycle(weakObj);
+        struct CircleSearchResults results = CircleSimpleSearchCycle(weakObj);
+        if(results.isUnclaimedCycle)
+            CircleZeroReferences(results.incomingReferences);
+        CFRelease(results.incomingReferences);
     }
-    NSLog(@"After collecting, chaining gives", [self->strong ptr]);
+    NSLog(@"After collecting, chaining gives %@", [self->strong ptr]);
     NSLog(@"After collecting, weak object is %@", weakObj);
 }