iPhone CGRectMake memory consuption

Question

On iPhone.. Why would code such as this cause memory leak? after 2 minutes the net bytes have doubled. All I'm doing is moving a ball round the screen with an NSTimer calling the below method.

Any ideas?

- (void)nextFrame:(NSNotification *)notification {
    ballInstance.frame = CGRectMake(value, 0,  320, 480);
}

Answer 1

The posted code has no leak. The problem is elsewhere.

If you know that there's a leak inside of nextFrame:, it has to be in -[Ball setFrame:] because it is the only message sent in this method.

Answer 2

The leak is not in the code you show, especially if frame is a @synthesized property. You either need to show more code, or spend some quality time with Instruments to figure out what is being leaked and where it is being allocated.

Answer 3

here is the 'full' code, new project, still behaves the same. It moves a jpg accross the screen, and as it does memory is massively consumed. If I remove the '++' from 'value' memory is fine. (in otherwords have a static graphic) So.... is the image being cached is the question? If so how can i stop it reaching astronomical sizes?

- (void)applicationDidFinishLaunching:(UIApplication *)application {    


    [window makeKeyAndVisible];

    NSTimer * nSTimer =[NSTimer scheduledTimerWithTimeInterval: .02
         target: self
       selector: @selector(tick)
       userInfo: nil
        repeats: YES];
    value =0;
}

- (void)tick {
    NSLog(@"tick");
    myOutlet1.frame = CGRectMake(value++, 0,  320, 480);
}

Answer 4

According to Apple "This is a bug in iPhone OS 3.0. The allocator for the graphics system
is reporting realloc events as malloc events, so ObjectAlloc tallies
these as new objects that are almost never being freed. I'm not
certain why you might not see it when you add the Leaks tool, but
neither tool would show a true leak for this."

from here.. http://lists.apple.com/archives/xcode-users/2009/Sep/msg00278.html

Though I'm still none the wiser as to how to remedy it.

Answer 5

I've posted a complete sample application that seems to more or less match your "new project" example above. Can you take a look at it and see if this gives you any ideas? I've run it on the simulator and on the device w/ no leak.

http://static.fatmixx.com/MemTestApp.zip

It really does look like there is NO leak here. I'm building against iPhoneOS 3.1 - Debug.

Sujal