Pthread mutex assertion error

Question

I'm encountering the following error at unpredictable times in a linux-based (arm) communications application:

pthread_mutex_lock.c:82: __pthread_mutex_lock: Assertion `mutex->__data.__owner == 0' failed.

Google turns up a lot of references to that error, but little information that seems relevant to my situation. I was wondering if anyone can give me some ideas about how to troubleshoot this error. Does anyone know of a common cause for this assertion?

Thanks in advance.

Answer 1

The quick bit of Googling I've done often blames this on a compiler mis-optimization. A decent summation is here. It might be worth looking at the assembly output to see if gcc is producing the right code.

Either that or you are managing to stomp on the memory used by the pthread library... those sort of problems are rather tricky to find.

Answer 2

Rock solid for 4 days straight. I'm declaring victory on this one. The answer is "stupid user error" (see comments above). A mutex should only be unlocked by the thread that locked it. Thanks for bearing with me.