Is it safe to schedule and invalidate NSTimers on a GCD serial queue?

Question

What\'s the right way to do this? The NSTimer documentation says this:

Special Considerations

You must send this

Answer 1

You should not install an NSTimer on an anonymous worker thread managed by GCD.

Use dispatch timer sources with GCD instead of NSTimer, c.f. dispatch_source_create(3).

NSTimer relies on the current thread's runloop, which is not something that makes sense for a GCD queue. See the WWDC2012 GCD session for more details around GCD and runloop APIs.