A Memory Management question

Hello,
So, I originally started with a book, but have transitioned over to taking the Stanford CS 193p class on iTunes U, which has been a much better form of learning for me. I'm fairly early on in the class, but I had a question, and was wondering if I can get some assistance.


Take this theoretical piece of code:

Code:

NSMutableArray *poly = [NSMutableArray alloc] init];
PolygonShape *polygon1 = [[PolygonShape alloc] init];
PolygonShape *polygon2 = [[PolygonShape alloc] init];
PolygonShape *polygon3 = [[PolygonShape alloc] init];

[poly addObject:polygon1];
[poly addObject:polygon2];
[poly addObject:polygon3];

Followed by:

Code:

[polygon1 release];
NSLog(@"test1");

[polygon2 release];
NSLog(@"test2");

[polygon3 release];
NSLog(@"test3");

[poly release];
NSLog(@"test4");

With the note that PolygonShape has the following method, simplified:

Code:

- (void)dealloc
{
NSLog(@"dealloc ran");

//release some integer ivars

[super dealloc];

}

My Console results are:

Code:

test
test2
test3
dealloc ran

followed by an EXC_BAD_ACCESS crash.

Why is dealloc only running when the array is released and not the objects I'm running it on? Isn't it my responsibility to individually release everything I ran alloc/init on in the local scope?

Thanks for any clarification on how I'm looking at this.

 

Aha! It was the combination of the two.

I did get some compiler warnings, and Guiyon's post explains the crashing, but I was focusing on the memory management question before tackling the crash.

I was trying to figure out why Dealloc wasn't being called until later; and jared_kipe hit the nail on the head. I didn't realize the array retained it. That explains why Dealloc was being called only after the array was released.

Thanks much, all.
So, I take it that this means that calling release on an array also makes it release everything it holds, correct?


OK, so one last thing. The application completes fully, but the console logs the following error:

Code:

2010-06-24 22:18:04.499 WhatATool[2547:80f] *** __NSAutoreleaseNoPool(): Object 0x1050f0 of class NSCFString autoreleased with no pool in place - just leaking
2010-06-24 22:18:04.507 WhatATool[2547:80f] *** -[NSAutoreleasePool drain]: This pool has already been released, do not drain it (double release).

Anu thoughts on the meaning of his?