Update text on CCLabelTFF end in bad access? - cocos2d-iphone

Question

I'm doing a little game in Coco2D and I have a countdown clock Note: As I am just trying to fix a bug, I am not working on cleanup so the timer can stop, etc.
Here is my code I'm using to setup the label and start the timer:
timer = [CCLabelTTF labelWithString:#"10.0000" fontName:#"Helvetica" fontSize:20];
timerDisplay = timer;
timerDisplay.position = ccp(277,310);
[self addChild:timerDisplay];
timeLeft = 10;
timerObject = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:#selector(updateTimer) userInfo:nil repeats:YES];
Note: timeLeft is a double
This is updateTimers's code:
-(void)updateTimer {
NSLog(#"Got Called!");
timeLeft = timeLeft -0.1;
[timer setString:[NSString stringWithFormat:#"%f",timeLeft]];
timerDisplay = timer;
timerDisplay.position = ccp(277,310);
[self removeChild:timerDisplay cleanup:YES];
//[self addChild:timerDisplay];
if (timeLeft <= 0) {
[timerObject invalidate];
}
}
When I run this I toggle between crashing on this this:
[timer setString:[NSString stringWithFormat:#"%f",timeLeft]];
and in the green arrow thing it gives Thread 1: EXEC_BAD_ACCESS (code=2, address=0x8)
and
0x197a7ff: movl 16(%edi), %esi and in the green arrow thing it gives Thread 1: EXEC_BAD_ACCESS (code=2, address=0x8)

Answer 1

It looks like your "timer" (not a very good name for a text object IMHO) is being auto-released because it was initialized with a convenience method. So when your timer fires it is likely attempting to manipulate a freed object. There are two ways to fix it: a. alloc and initialize the object yourself, or b. add a "retain" message to it such as:
[[CCLabelTTF labelWithString:#"10.0000" fontName:#"Helvetica" fontSize:20] retain];
In both cases you will then be responsible to release the object in your dealloc or similar method when you are done with it:
[timer release];