The Queue join implementation uses a non-timed wait that blocks the main
thread, making it impossible to interrupt it with CTRL+C or sending
SIGINT signal. Using any timeout value for wait would fix the problem,
but Queue doesn't allow to pass a timeout to the join method. The
Queue implementation is actually quite simple, so we can just add our
own implementation with only the things we really need and use a timeout
value when calling wait() in join().