Re: NSAnimation crashing on Leopard;

FROM : Martin Redington
DATE : Sun Nov 25 13:47:41 2007

Could this be crashing because you are updating the text field 
outside the main thread?

There might be a special case for allowing UI updates from an 
NSAnimationNonblockingThreaded threads, in which case you have hit a 
bug, but I don't recall seeing any mention of this in the docs.

If NSAnimationNonblockingThreaded isn't documented as permitting 
thread-safe UI updates, then the behaviour you're seeing is as 
documented - expect crashes.

You'll either need to avoid using NSAnimationNonblockingThreaded - 
NSAnimationNonblocking should be ok for most purposes. If you can't 
avoid it, you'll need to perform UI updates via 
performSelectorOnMainThread, or similar.



On 21 Nov 2007, at 16:42, Matt Budd wrote:

> No response here, so I've filed an Apple bug for this: 5610019.
>
>  - Matt
>
> On 19-Nov-07, at 4:04 PM, Matt Budd wrote:
>

>> We found a strange crash in our app with NSAnimation. It appears 
>> to have something to do with the blocking mode of 
>> NSAnimationNonBlockingThreaded.
>>
>> The crash is very reproduceable, and you can do it simply with the 
>> attached sample code. Create a new app, put a textfield on the 
>> main window in IB, instantiate the AppController object in IB, and 
>> set it to be the window's delegate (and hook up the text field you 
>> created).
>>
>> If you then run the code and resize the window a bunch, it will 
>> crash on you. Usually takes about 10-20 seconds of resizing. 
>> However, if I change the NSAnimationNonblockingThreaded to 
>> NSAnimationNonblocking, it doesn't crash and works fine. 
>> Unfortunately, my app requires each animation to be in its own 
>> thread, so I need to use that mode.
>>
>> Any ideas what is happening here? When I try it on Tiger, it 
>> doesn't crash, but the weird thing always was that the number of 
>> threads (from Activity Monitor) goes through the roof...it's like 
>> they never die off when I stop and restart the animation. Does 
>> Leopard enforce a maximum number of threads or something?
>>
>>  - Matt
>>
>>
>> //--------------------------------------------------
>> #import <Cocoa/Cocoa.h>
>>
>> @interface AppController : NSObject {
>>    IBOutlet NSTextField *lblValue; //Attach this to a NSTextView 
>> in IB
>>    NSAnimation *_oAnimator;
>> }
>>
>> @end
>>
>>
>> @implementation AppController
>>
>> - (id)init
>> {
>>    if (self = [super init]) {
>>        _oAnimator = [[NSAnimation alloc] init];
>>        [_oAnimator setDelegate: self];
>>        [_oAnimator setAnimationBlockingMode: 
>> NSAnimationNonblockingThreaded];
>>        [_oAnimator setAnimationCurve: NSAnimationEaseInOut];
>>        [_oAnimator addProgressMark: 0.00];
>>        [_oAnimator addProgressMark: 0.25];
>>        [_oAnimator addProgressMark: 0.50];
>>        [_oAnimator addProgressMark: 0.75];
>>        [_oAnimator addProgressMark: 1.00];
>>    }
>>    return self;
>> }
>>
>> - (void)dealloc
>> {
>>    [_oAnimator setDelegate: nil];
>>    [_oAnimator release];
>>
>>    [super dealloc];
>> }
>>
>> - (void)windowDidResize: (NSNotification *)poNotification
>> {
>>    [_oAnimator stopAnimation];
>>    [_oAnimator setDuration: 1.0];
>>    [_oAnimator startAnimation];
>> }
>>
>> - (void)animation: (NSAnimation*)poAnimation didReachProgressMark: 
>> (NSAnimationProgress)pfProgress
>> {
>>    if (poAnimation == _oAnimator) {
>>        [lblValue setStringValue: [NSString stringWithFormat: @"%
>> f", pfProgress]];
>>    }
>> }
>>
>> @end
>> //--------------------------------------------------

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