Sporadically pyocf Queue will raise RuntimeException in test

[jfckm]

Description

Sometimes in test logs there would be an exception raised by queue object serving the role of management queue. This exception is caused by calling .join() by thread on itself, which means that last ocf_queue_put is called from code executed on this queue which shouldn't happen. Most possibly it is an error with pyocf handling of queue lifetime.

[arutk]

I assume the problem is with management queue.

OCF cache does not put management queue on stop. It is adapter responsibility to put management queue after cache is stopped. Typically this must not be done from outside of cache stop completion callback, as this might run in management queue context.

I don't understand what triggers the problematic queue_put(). This remains to be investigated.