Changeset 23524

Timestamp:

05/20/2008 07:55:56 PM (7 months ago)

Author:

evands

Message:

• Avoid the possibility of modifying the set of list object observers being enumerated by copying/autoreleasing it before enumeration.
  
• Keep track of observers removed while observers are being notified, and avoid messaging them subsequently. Fixes #9425, where I wrote:
  

The problem occurs when a list object observer is unregistered and deallocates in response to the status update being posted. In this specific case, AIContactMenu is a list object observer, responds to an update by informing its delegate, which happens to be an AIAccountSelectorView. AIAccountSelectorView destroys and then recreates its AIAccountMenu... and then the enumeration of the observers continues, eventually trying to message the old AIAccountMenu, which has now been deallocated. *boom*.

Files:

• trunk/Source/AdiumContactPropertiesObserverManager.h (modified) (2 diffs)
• trunk/Source/AdiumContactPropertiesObserverManager.m (modified) (5 diffs)

trunk/Source/AdiumContactPropertiesObserverManager.h

@@ -12 +12 @@
-@interface AdiumContactPropertiesObserverManager : AIObject {
-        //Status and Attribute updates
-
+
+
-    NSTimer                                     *delayedUpdateTimer;
-    int                                         delayedStatusChanges;
@@ -20 +21 @@
-
-        BOOL                                    updatesAreDelayed;
+        
+        BOOL                                    informingObservers;
-        /* Only the contact controller can speak to us directly, and it's allowed to access these ivars */
-@public

trunk/Source/AdiumContactPropertiesObserverManager.m

@@ -249 +249 @@
-#endif
-    [contactObservers removeObject:[NSValue valueWithNonretainedObject:inObserver]];
+        
+        /* If we're in the middle of informing observers, we need to note this now-removed observer
+         * so that we don't attempt to message it during this iteration.
+         */
+        if (informingObservers) {
+                if (!removedContactObservers) removedContactObservers = [[NSMutableSet alloc] init];
+                [removedContactObservers addObject:[NSValue valueWithNonretainedObject:inObserver]];
+        }
-}
-
@@ -323 +331 @@
-        NSValue                 *observerValue;
-        
+        informingObservers = YES;
+
-        //Let our observers know
-contactObservers
+[[contactObservers copy] autorelease]
-        while ((observerValue = [enumerator nextObject])) {
-                NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
-                id <AIListObjectObserver>       observer;
-                NSSet                                           *newKeys;
+                
+                /* Skip any observer which has been removed while we were iterating over observers,
+                 * as we don't retain observers and therefore risk messaging a released object.
+                 */
+                if (removedContactObservers && [removedContactObservers containsObject:observerValue])
+                        continue;
-                
-                observer = [observerValue nonretainedObjectValue];
@@ -341 +356 @@
-                        [attrChange unionSet:newKeys];
-                }
-                [pool release];
-        }
-        //Send out the notification for other observers
@@ -349 +363 @@
-                                                                                                                                                                                                 forKey:@"Keys"] : nil)];
-        
+        informingObservers = NO;
+
+        //If we removed any observers while informing them, we don't need that information any more
+        if (removedContactObservers) {
+                [removedContactObservers release]; removedContactObservers = nil;
+        }
+
-        return [attrChange autorelease];
-}
@@ -355 +376 @@
-- (void)_updateAllAttributesOfObject:(AIListObject *)inObject
-{
-contactObservers
+[[contactObservers copy] autorelease]
-        NSValue                 *observerValue;
-
-
+
+
+
+
+
+
+
+
+
+
-                id <AIListObjectObserver> observer = [observerValue nonretainedObjectValue];
-                
-                [observer updateListObject:inObject keys:nil silent:YES];
-        }
+        
+        informingObservers = NO;
-}
-