Ethan-Zhang

class MyHTTPServer(tornado.httpserver.HTTPServer):
    _stopped = False

    def _quit_if_ioloop_is_empty(self):
        ioloop = tornado.ioloop.IOLoop.instance()
        if len(ioloop._handlers) <= 1:
            logger.info("Graceful shutdown complete. Exiting!")
            exit(0)
        else:
            logger.info("Waiting for ioloop to be empty. has %d handlers left" % len(ioloop._handlers))