Question

Okay so I know I asked a similar question a while ago, but this is different. I now have two timers that go off on the TouchDown event of their respective buttons. On the TouchUpInside event I have respective code that tells each timer to [pressTimer invalidate] and pressTimer = nil. The problem that happens now since I added the second timer is that when the selector is triggered (thus releasing the button and triggering the TouchUpInside event) the app crashes and spits out an Not recognized [NSCFTimer -invalidate] or something like that. The buttons work normally, until the timer triggers, and even then no crash until I let up my finger. I think what’s going on is that the TouchUpInside event is trying to invalidate an invalid/triggered timer, because it works fine while the timer is still running. I wonder why this is happening since it never happened before I added the second timer. My temporary fix is to set the repeating:YES portion of the timer, which supports my theory that it can’t invalidate an invalid/triggered timer. Any suggestions?

*Bonus: On a related note, how many crashes do I need to get from people before they show up in iTunes Connect?

Answer 1

For one thing, the pressTimer=nil serves no purpose; nil assignment only releases objects when using a setter, on a retained property, i.e. self.timer = nil;. (this actually does: [self setTimer:nil]!)

But even then, if you misquoted yourself and did use a setter, an NSTimer instance need not be released, it only needs to be invalidated. Your “kind of quoted” error should not happen.

As for you theory: you may read invalidate as release in this context – you can’t do it too often…

The manual states that invalidate needs to be called from the same thread where it was installed, beyond that there’s really no reason for anything to crash.