CoreAnimation uncommitted CATransaction warning

Question

On Mac OS 10.8 I'm getting the following warning in my app:

CoreAnimation: warning, deleted thread with uncommitted CATransaction;

It suggests turning on CA_DEBUG_TRANSACTIONS=1 in environment to log backtraces, which I did.

This is the top of my backtrace:

0   QuartzCore          0x00007fff88a84b95 _ZN2CA11Transaction4pushEv + 219
1   QuartzCore          0x00007fff88a8476d _ZN2CA11Transaction15ensure_implicitEv + 273
2   QuartzCore          0x00007fff88a8bb6a _ZN2CA5Layer12begin_changeEPNS_11TransactionEjRP11objc_object + 44
3   QuartzCore          0x00007fff88a8cb4e _ZN2CA5Layer10set_boundsERKNS_4RectEb + 452
4   QuartzCore          0x00007fff88a8c908 -[CALayer setBounds:] + 189

Does anyone know what this warning is, and how to avoid it?

Answer 1

I found that wrapping the offending code an explicit CATransaction with actions disabled made the warning go away.

i.e.

[CATransaction begin];
[CATransaction setDisableActions:YES];
layer.bounds = CGRectMake(0, 0, 1000, 1000);
[CATransaction commit];