Method shutdown

Lib/concurrent/futures/thread.py:254–273

(self, wait=True, *, cancel_futures=False)

                    work_item.future.set_exception(self.BROKEN(self._broken))

    def shutdown(self, wait=True, *, cancel_futures=False):
        with self._shutdown_lock:
            self._shutdown = True
            if cancel_futures:
                # Drain all work items from the queue, and then cancel their
                # associated futures.
                while True:
                    try:
                        work_item = self._work_queue.get_nowait()
                    except queue.Empty:
                        break
                    if work_item is not None:
                        work_item.future.cancel()

            # Send a wake-up to prevent threads calling
            # _work_queue.get(block=True) from permanently blocking.
            self._work_queue.put(None)
        if wait:
            for t in self._threads:
                t.join()
    shutdown.__doc__ = _base.Executor.shutdown.__doc__