Removing CAKeyframeAnimation doesn't release the memory

Question

I'm adding a CAKeyframeAnimation to the layer of an ImageView for representing the animation of an image:

CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"contents"];
animation.values = arrayOfImages;
[animation setRemovedOnCompletion:YES];
animation.delegate = self;
[animation setValue:delegate forKey:@"AnimatedImageViewDelegate"];
animation.repeatCount = repeatCount;
animation.fillMode = kCAFillModeForwards;
animation.calculationMode = kCAAnimationDiscrete;
[animation setValue:animationName forKey:@"name"];

When I want to start the animation I call:

animation.duration = duration;
[self.layer addAnimation:animation forKey:animationName];
[self.layer setContents:[animation.values lastObject]];

When the animation finishes, I want to completely remove it and release its memory.

[self.layer removeAllAnimations];       
[self.layer removeAnimationForKey:animationName];

Doing this, and using Instruments-Activity Monitor, the memory is not relased unless I release the complete imageView.

How can I release that animation memory without destroy the UIImageView???

Answer 1

You are using the convenience method to instantiate the object. So you will not have control over when the object is actually released. To have control over that, you will need to alloc the object and dealloc it yourself:

Create the instance:

CAKeyframeAnimation *animation = [[CAKeyframeAnimation alloc] init];

Then after the animation finished call after your remove lines:

[animation release];

Answer 2

In my case the CAKeyframeAnimation added to an imageView and container view is not getting released even that its not on the view hierarchy.

It turned out that the CAKeyframeAnimation delegate was holding it. I just removed the delegate:

beatAnimation.delegate = nil

Answer 3

I have same problem about memory with CAKeyframeAnimation when set values = array of images. And i see that the problem i get is that the images are inited by [UIImage imagewithname:] which is cached to memory by default. So my solution is change to use [UIImage imageWithContentsOfFile:] Hope this helpful.

Answer 4

First off, if this is an iOS 5 project ARC should be handling your releases for you - which is really nice!

Now -- I used a lot of animations in my project and noticed similar bursts in the heap. My guess is that CA caches a lot of what is animated internally. To confirm those items are actually being autoreleased I recommend setting up a test for allocations or leaks with the instruments tool and do the following:

1. Determine a situation where you would trigger and the animation.
2. Mark the heap after the animation completes.
3. Trigger something that would take you to another view where the objects should have been removed.
4. Repeat the process in steps 1-2-3 as many times as you want. I normally do it about 10 times or so.

That's it.. basically animate - mark - undo - animate - mark. You should see the heapshots decreasing to 0 or almost 0 if CoreAnimation is autoreleasing objects correctly!

For more info on how to test like this take a look at this article:

http://www.friday.com/bbum/2010/10/17/when-is-a-leak-not-a-leak-using-heapshot-analysis-to-find-undesirable-memory-growth/