Fix "Error freeing dispatch queue"

[dsmith]

I get an occasional error message (listed above). Due to race condition/multi-threading issue, probably in dispatch cancellation logic.

[etaurel@…]

Hi,

I think there is a way to solve this problem. The error comes from the "queue_free" function of the queue management and more specifically from the "pthread_cond_destroy()" in this function. This call returns the error code EBUSY. I think this system call returns this error due to the thread cancellation while it was waiting in the same condition variable (only a guess) Anyway, by modifying the code in the following way, I do not have error message any more.

while (pthread_cond_destroy(&queue->cond) == EBUSY) {

pthread_cond_broadcast(queue->cond);

} The code passes only once in this loop.

Hoping this help

Emmanuel Taurel

[dsmith]

I'll leave the ticket open in case there's another 0.5 release, but the API overhaul in 0.6 gets rid of the queues.

I hadn't noticed that one, but there's another condition in which the dispatch thread can try to lock a mutex that's already been destroyed.

Thanks for the fix.

[dsmith]

To be reopened if there's another 0.5 release (unlikely).