'Consume the queue items'

def run(self):

    while True:
        try:
            work_unit = self.in_queue.get()
        except KeyboardInterrupt:
            continue
        if (work_unit == POISON_PILL):
            try:
                self._teardown()
            finally:
                self.in_queue.task_done()
                break
        else:
            try:
                self._consume(work_unit)
            finally:
                self.in_queue.task_done()
