Question

I am allocating myMDD in main which contains an NSMutableArray instance variable (alloc/init-ed in init). When I add items to the NSMutableArray (frameList) I release after adding. The array and the objects it now contains are released at the bottom of main.

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    MDD *myMDD = [[MDD alloc] init];
    Frame *myFrame = [[Frame alloc] init];

    [myMDD addFrame:myFrame];

    [myMDD release];
    [pool drain];
    return 0;
}

// METHOD_ mdd addFrame:
-(void)addFrame:(Frame*) inFrame {
    [frameList addObject:inFrame];
    [inFrame release];
}

// METHOD_ mdd dealloc
-(void)dealloc {
    NSLog(@"_deal...: %@", self);
    [frameList release];
    [super dealloc];
}

My question is that the “static analyser” reports a potential memory leak, prefering to have the release for frame added main. (i.e)

 int main (int argc, const char * argv[]) {

    ...

 [myFrame release]; // Added
    [myMDD release];
    [pool drain];
    return 0;
}

// METHOD_ mdd addFrame:
-(void)addFrame:(Frame*) inFrame {
    [frameList addObject:inFrame];
    // [inFrame release];
}

I can see why this is, if I alloc myMDD and never call addFrame then I need to release it. Maybe its just a case of adding a autorelease to myMDD, but would that work in the situation where I call addFrame and the NSMutableArray is releasing the object?

EDIT_001

Changed to …

int main (int argc, const char * argv[]) {
    ...
    [myMDD addFrame:myFrame];
    [myFrame release];
    myFrame = nil;

    [myMDD release];
    [pool drain];
    return 0;
}

// METHOD_ mdd addFrame:
-(void)addFrame:(Frame*) inFrame {
    [frameList addObject:inFrame];
}

gary

Answer 1

As per convention, an add method should just retain the object if needed, not release it. And as a general rule, you should not release object that you did not retain, in your example the scope where you retained (created) the frame is not the same as in the addFrame method.

By scope I mean logic scope, not language scope.

In that particular example, you must call release just after addFrame. But the release should not be in the addFrame method.