Queuing a stop means you have to process the queue before stopping. Which certainly is stopping cleanly, but if you wanted to stop the thread because its queue

Queuing a stop means you have to process the queue before stopping. Which certainly is stopping cleanly, but if you wanted to stop the thread because its queue was too long and the work requests were stale, it doesn't help much. You could maybe allow a queue skipping feature to be used for stop messages... But if it's only for stop messages, set an atomic bool stop, then send a stop message. If the thread just misses the stop bool and waits for messages, you'll get the stop message; if the queue is large, you'll get the stop bool. ps, hi