Objective-C determine what objects retain another object

Question

I have some problems with memory leaks on iPhone (imagine that), and I have a custom object with a retain count of 10.

Is there any way I can know what code triggered the retain count increased for a specific object instance? I am using GHUnit if that matters.

Answer 1

Try using the Build & Analyze . It can usually tell you if an object is being retained and not released./

Answer 2

The leaks tool (one of the "instruments" in XCode) is able to analyse that sort of thing, but I don't think you can do it programatically.

Here is a great tutorial: http://mobileorchard.com/find-iphone-memory-leaks-a-leaks-tool-tutorial/

(Update to summarise comments): If you'd like to set a breakpoint in the retain method (to look at the stack trace) you can override the retain method.

Answer 3

The retain counts are nearly useless—if something gets retain ed and autorelease d in a statement, that's perfectly fine, but its retain count will increase by 1.

If you want to find exactly where a particular object is being retain ed, override the class's retain implementation to test for your object(s), and set a breakpoint there:

@implementation MyClass
-(id) retain
{
    if(self == ObjectThatImTracking)
        NSLog(@"[ObjectThatImTracking retain]\n");  // put a breakpoint here
    return [super retain];
}

Then run your program in the debugger and look at the call stack when the breakpoint gets hit.

Answer 4

Did you trying to find all retain cases of your class in modules? Maby it helps..