Instruments show memory leak - Xcode 5 / iOS7

Question

I have the following piece of code:

NSString *bgImageName = [[Useful instance] getRootviewBackgroundImageName];
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:bgImageName]];
imageView.clipsToBounds = YES;
CGRect rc = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
[imageView setFrame:rc];
[self.view insertSubview:imageView atIndex:0];
[imageView release];

Instruments shows 100% and a memory leak at line two in the above code, which was not the case in xcode 4.6. I am working now with xCode 5 on osx 10.8.5

It seems, that i properly release the allocated UIImageView (line 7) which gets inserted in my view at line 6, so i can't see why intruments is bringing up a memory leak warning.

Does anybody know why instuments brings up that (in my opinion) wrong information?

EDIT: here's the instruments-screenshot with the allocation-summary of my leaked object:

The UIKit and QuartzCore are retaining my object, which is the reason for my leaking UIImageView (or am I wrong with this assumption?).

The UIImageView is inserted to the view (a UIViewController), which is referenced in my xib-file. How can control what happens with my added UIImageView after adding it to 'self.view'?

Answer 1

I had the same issue with Xcode 5 on iOS 7. After some experimentation I noticed that Instruments does not show a mem leak when running against the iOS 6.1 simulator or against a device (iPhone 5s) running iOS 7. Based on these I can only conclude that this is a false positive and a bug in the iOS 7 simulator.

EDIT: This issue no longer occurs after I updated to Xcode 5.0.1 and OS X Mavericks (I'm guessing it's the first that fixed it but can't tell for sure).

Answer 2

Instruments is showing the line of code that triggered the allocation of the leaked object and not why the object was actually leaked. Turn on reference count tracking and look at all the retain/release events on that image view. There'll be an extra retain (or a missing release).