Method _dispatch_callback_event

pywebio/session/threadbased.py:245–275

(self)

        logger.debug('Callback thread start')

    def _dispatch_callback_event(self):
        while not self.closed():
            event = self.callback_mq.get()
            if event is None:  # 结束信号
                logger.debug('Callback thread exit')
                break

            callback_info = self.callbacks.get(event['task_id'])
            if not callback_info:
                logger.error("No callback for callback_id:%s", event['task_id'])
                return
            callback, mutex = callback_info

            @wraps(callback)
            def run(callback):
                try:
                    callback(event['data'])
                except Exception as e:
                    # 子类可能会重写 get_current_session ，所以不要用 ThreadBasedSession.get_current_session 来调用
                    if not isinstance(e, SessionException):
                        self.on_task_exception()

                # todo: good to have -> clean up from `register_thread()`

            if mutex:
                run(callback)
            else:
                t = threading.Thread(target=run, kwargs=dict(callback=callback),
                                     daemon=True)
                self.register_thread(t)
                t.start()

    def register_callback(self, callback, serial_mode=False):
        """ 向Session注册一个回调函数，返回回调id