What do the numbers in brackets next to my app name in the Xcode console mean?

Question

What do the numbers in brackets mean?

2012-12-01 10:14:25.769 MyApp[3714:907] -[MyAppDelegate applicationDidEnterBackground:]
2012-12-01 10:14:46.058 MyApp[3714:490b] *** -[UIProgressView respondsToSelector:]: message sent to deallocated instance 0x2084a050

The 3714 and 907. Is one the process ID? What's the other? I'm trying to figure out why all the messages ended in 907 until that error on the last line which ended in 490b.

Answer 1

The 3714 is the Unix process ID: the value returned by getpid(), formatted with %d.

The 907 or 490b is a thread ID: the value returned by pthread_mach_thread_np(pthread_self()), formatted with %x.