int vortex_async_queue_waiters ( VortexAsyncQueue queue)

Allows to get current waiting threads on the provided queue.

queueThe queue that is being used to request the number of waiting threads.
The number of waiting threads or -1 if it fails. The only way to make the function to fail is to provide a null queue reference.

References vortex_mutex_lock(), and vortex_mutex_unlock().

Referenced by vortex_listener_unlock(), and vortex_thread_pool_stats().