-[CALayer release]: message sent to deallocated instance

Question

I\'m having a problem with some code in the loadView: method of one of my view controllers. Essentially I have a view which centres itself in a larger view (on an iPad) and

Answer 1

Profile your application in the simulator with 'Zombies' Instrument.

Run your app for a while and do whatever you have to do to make your app crash. When it does, you will get a pop up like the image below and it will halt the profiling of the app:

Then if you click on the little arrow next to the address (0x158b3c00) .. it will take you to the object retain/release history for the object that was over released (the zombie).

If you highlight the line above where the retain count went to -1, and open View -> Extended detail, it should point you to the stack trace and line in your code where the object was overreleased:

If you double click the class where it is occuring, it will open up your source and show you the bad line of code:

Answer 2

The over-releasing could be occurring during the objects life time and not just when they're being created. A few tips:

• use accessors to ensure that pointers are set to nil
• be consistent with your use of release/autorelease. Personally I prefer to have [[[Class alloc] init] autorelease] all on 1 line.
• Learn the difference between release/autorelease. Let's Build NSAutoreleasePool is a good place to start.