CAKeyframeAnimation - Animating an Array of Images creates a huge allocation after completion - ios

Question

I'm trying to animate an array of UIImage with CAKeyframeAnimation. Easy in theory.
Sample code at the bottom of the post.
My problem is that after the animation did finish, I've got a huge leak that is impossible to get rid of it.
Code to init CAKeyframeAnimation:
- (void)animateImages
{
CAKeyframeAnimation *keyframeAnimation = [CAKeyframeAnimation animationWithKeyPath:#"contents"];
keyframeAnimation.values = self.imagesArray; // array with images
keyframeAnimation.repeatCount = 1.0f;
keyframeAnimation.duration = 5.0;
keyframeAnimation.removedOnCompletion = YES;
CALayer *layer = self.animationImageView.layer;
[layer addAnimation:keyframeAnimation
forKey:#"flingAnimation"];
}
Adding a delegate to the animation and removing the animation manually cause the same leak effect:
... // Code to change
keyframeAnimation.delegate = self;
// keyframeAnimation.removedOnCompletion = YES;
keyframeAnimation.removedOnCompletion = NO;
keyframeAnimation.fillMode = kCAFillModeForwards;
....
Then:
- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
{
if (flag)
{
[self.animationImageView.layer removeAllAnimations];
[self.animationImageView.layer removeAnimationForKey:#"flingAnimation"]; // just in case
}
}
The result is always a huge allocation. The size of the stack of memory is proportional to the size of the images:
I uploaded an example to GitHub to check the code.

Answer 1

SOLVED
I found the problem.
As gabbler was saying there was not a leak problem. The problem was a high allocation of Images.
I was releasing the array with the images, however, the images did not disappear from memory.
So finally I found the problem:
[UIImage imageNamed:#""];
From method definition:
This method looks in the system caches for an image object with the specified name and returns that object if it exists. If a matching image object is not already in the cache, this method locates and loads the image data from disk or asset catelog, and then returns the resulting object. You can not assume that this method is thread safe.
So, imageNamed: stores the image in a private Cache.
- The first problem is that you can not take control of the cache size.
- The second problem is that the cache did not get cleaned in time and if you are allocating a lot of images with imageNamed:, your app, probably, will crash.
SOLUTION:
Allocate images directly from Bundle:
NSString *imageName = [NSString stringWithFormat:#"imageName.png"];
NSString *path = [[NSBundle mainBundle] pathForResource:imageName
// Allocating images with imageWithContentsOfFile makes images to do not cache.
UIImage *image = [UIImage imageWithContentsOfFile:path];
Small problem:
Images in Images.xcassets get never allocated. So, move your images outside Images.xcassets to allocate directly from Bundle.
Example project with solution here.