How can I determine which objects hold references to other objects that are causing memory leaks in objective-c?

Question

I have tried using the leaks tool, and "analyze" etc to find the leak, but it can't find it. Using allocations I can determine the objects which are not being released.

I have noticed (by adding debugging statements in the dealloc method), that dealloc is not called for these objects.

How can I determine which objects are holding references to these objects and preventing them from being released?

Answer 1

If you need to see where retains, releases and autoreleases occur for an object use instruments:

Run in instruments, in Allocations set "Record reference counts" on on (you have to stop recording to set the option). Cause the picker to run, stop recording, search for there ivar (datePickerView), drill down and you will be able to see where all retains, releases and autoreleases occurred.

Answer 2

The analyze tool was unable to detect the problem. Using the allocations tool to capture all the reference counts was a start, but there were so many classes I didn't recognize, or access directly, I was not able to track down the problem using this method. Instead, I made a list of the classes that I was directly responsible for, and investigated each of them line by line till I found the problems. The cause was that I used some third party libraries which didn't decrement the retain count of some of my objects as expected. I guess in this case, following better software engineering principles / design patterns, and having thorough code reviews may have caught the problem earlier.