If a thread can do no more for the moment, then either it is finished, or it is waiting for something to happen. In the latter case, the best thing is to be wok

If a thread can do no more for the moment, then either it is finished, or it is waiting for something to happen. In the latter case, the best thing is to be woken on that event, and the next best is to poll for it. Sleep is only the best solution when that event is literally the passage of time.