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PONSManagedObjects that I own being released by main.m?
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  1. PONSManagedObjects that I own being released by main.m?
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    copied!<p>First, in my root view controllers viewDidLoad, I initialize an NSDictionary with arrays of NSManagedObjects, like so:</p> <pre><code>- (void)viewDidLoad { [super viewDidLoad]; self.title = @"Decks"; UIBarButtonItem *browseButton = [[UIBarButtonItem alloc] initWithTitle:@"Browse" style:UIBarButtonItemStylePlain target:self action:@selector(loadBrowseView)]; self.navigationItem.rightBarButtonItem = browseButton; [browseButton release]; NSError *error = nil; if (![[self fetchedResultsController] performFetch:&amp;error]) { } self.categories = [fetchedResultsController fetchedObjects]; NSMutableDictionary *tipsMutableDictionary = [[NSMutableDictionary alloc] init]; for (Category *category in self.categories) { NSMutableArray *tipsToSort = [NSMutableArray arrayWithArray:[[category valueForKey:@"tips"] allObjects]]; NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending: YES]; [tipsToSort sortUsingDescriptors: [NSArray arrayWithObject: sortDescriptor]]; [sortDescriptor release]; [tipsMutableDictionary setObject:[NSArray arrayWithArray:tipsToSort] forKey:[category name]]; } self.tips = tipsMutableDictionary; [tipsMutableDictionary release]; } </code></pre> <p>Now "self.tips", which is a retained NSDictionary property on my root view controller, is set up to contain arrays of NSManagedObjects. I happily go along using that data for about 5 minutes (including passing it to other view's retained properties) until I get the following message:</p> <pre><code>malloc: *** error for object 0x3b300b0: double free </code></pre> <p>At this moment, after the error but before actually crashing, the backtrace is as follows:</p> <pre><code>#0 0x98152072 in malloc_error_break () #1 0x98153218 in szone_error () #2 0x9815334d in free_tiny_botch () #3 0x01b83064 in _PFDeallocateObject () #4 0x01b8d315 in -[_PFManagedObjectReferenceQueue _processReferenceQueue:] () #5 0x01bba9ba in _performRunLoopAction () #6 0x01d42252 in __CFRunLoopDoObservers () #7 0x01d4165f in CFRunLoopRunSpecific () #8 0x01d40c48 in CFRunLoopRunInMode () #9 0x0252d615 in GSEventRunModal () #10 0x0252d6da in GSEventRun () #11 0x002a3faf in UIApplicationMain () #12 0x00002830 in main (argc=1, argv=0xbfffef60) at /Users/***/main.m:14 </code></pre> <p>Notably, there is no code of mine in there.</p> <p>A print object on 0x3b300b0 reveals:</p> <pre><code>&lt;Tip: 0x3b300b0&gt; (entity: Tip; id: 0x3b2ffe0 &lt;x-coredata://10B4E6EE-ACF3-4316-AE10-6E06E8FFFF46/Tip/p9&gt; ; data: &lt;fault&gt;) </code></pre> <p>And most interestingly, the shell malloc_history on that address:</p> <pre><code>ALLOC 0x3b300b0-0x3b300ef [size=64]: thread_a0a3f500 |start | main | UIApplicationMain | -[UIApplication _run] | CFRunLoopRunInMode | CFRunLoopRunSpecific | PurpleEventCallback | _UIApplicationHandleEvent | -[UIApplication sendEvent:] | -[UIApplication handleEvent:withNewEvent:] | -[UIApplication _reportAppLaunchFinished] | CA::Transaction::commit() | CA::Context::commit_transaction(CA::Transaction*) | CALayerLayoutIfNeeded | -[CALayer layoutSublayers] | -[UILayoutContainerView layoutSubviews] | -[UINavigationController _startDeferredTransitionIfNeeded] | -[UINavigationController _startTransition:fromViewController:toViewController:] | -[UINavigationController _layoutViewController:] | -[UINavigationController _computeAndApplyScrollContentInsetDeltaForViewController:] | -[UIViewController contentScrollView] | -[UIViewController view] | -[RootViewController viewDidLoad] | -[_NSFaultingMutableSet allObjects] | -[_NSFaultingMutableSet willRead] | -[NSManagedObjectContext(_NSInternalAdditions) _retainedObjectWithID:optionalHandler:withInlineStorage:] | +[NSManagedObject(_PFDynamicAccessorsAndPropertySupport) allocWithEntity:] | _PFAllocateObject | malloc_zone_calloc ---- FREE 0x3b300b0-0x3b300ef [size=64]: thread_a0a3f500 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __CFRunLoopDoObservers | _performRunLoopAction | -[_PFManagedObjectReferenceQueue _processReferenceQueue:] | -[NSManagedObjectContext(_NSInternalAdditions) _forgetObject:propagateToObjectStore:] | -[NSManagedObjectContext(_NSInternalAdditions) _forgetObject:propagateToObjectStore:removeFromRegistry:] | CFDictionaryRemoveValue | CFRelease | _PFDeallocateObject | malloc_zone_free ALLOC 0x3b300b0-0x3b300cf [size=32]: thread_a0a3f500 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __CFRunLoopDoObservers | _performRunLoopAction | -[_PFManagedObjectReferenceQueue _processReferenceQueue:] | _PFDeallocateObject | free_tiny_botch | szone_error | start | _NSPrintForDebugger | -[NSManagedObject description] | +[NSString stringWithFormat:] | -[NSPlaceholderString initWithFormat:locale:arguments:] | _CFStringCreateWithFormatAndArgumentsAux | CFStringCreateMutable | _CFRuntimeCreateInstance | malloc_zone_malloc </code></pre> <p>My interpretation of the above is that "[RootViewController viewDidLoad]" in the first ALLOC statement is me initially populating the tips NSDictionary with data. Then in following FREE statement, main.m decides to free those objects even though they are in a retained NSDictionary that I have responsibility for releasing?</p> <p><strong>EDIT Per request, here is the NSZombieEnabled output:</strong></p> <pre><code>*** -[CFString retain]: message sent to deallocated instance 0x3b300b0 </code></pre> <p>Backtrace after that:</p> <pre><code>#0 0x01d6a3a7 in ___forwarding___ () #1 0x01d466c2 in __forwarding_prep_0___ () #2 0x01cfd988 in CFRetain () #3 0x01cfd495 in CFArrayCreate () #4 0x01d406c3 in -[__NSPlaceholderArray initWithObjects:count:] () #5 0x01d4f6f8 in -[NSArray initWithArray:copyItems:] () #6 0x01d5c408 in +[NSArray arrayWithArray:] () #7 0x0000392f in -[RootViewController getRandomTip:] (self=0x3e1db40, _cmd=0x745b, sender=0x3e27d60) at /Users/***/RootViewController.m:32 #8 0x00299405 in -[UIApplication sendAction:to:from:forEvent:] () #9 0x002fcb4e in -[UIControl sendAction:to:forEvent:] () #10 0x002fed6f in -[UIControl(Internal) _sendActionsForEvents:withEvent:] () #11 0x002fdabb in -[UIControl touchesEnded:withEvent:] () #12 0x002b2ddf in -[UIWindow _sendTouchesForEvent:] () #13 0x0029c7c8 in -[UIApplication sendEvent:] () #14 0x002a3061 in _UIApplicationHandleEvent () #15 0x0252ed59 in PurpleEventCallback () #16 0x01d41b80 in CFRunLoopRunSpecific () #17 0x01d40c48 in CFRunLoopRunInMode () #18 0x0252d615 in GSEventRunModal () #19 0x0252d6da in GSEventRun () #20 0x002a3faf in UIApplicationMain () #21 0x00002830 in main (argc=1, argv=0xbfffef60) at /Users/***/main.m:14 </code></pre> <p>The referenced line of code from above (/Users/***/RootViewController.m:32) is:</p> <pre><code>NSArray *tipsArray = [NSArray arrayWithArray:[self.tips objectForKey:categoryNameString]]; </code></pre> <p>All that I can tell from this is that the objects I am trying to access from "self.tips" have already been released (by who? and why?)</p>
 

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