MQTT 订阅在多线程中无法正常工作

Question

我有如下代码

    threads = []
    t = threading.Thread(target=Subscribe('username', "password", "topic", "host",port).start)
    t1 = threading.Thread(target=Subscribe('username2', "password2", "topic2", "host",port).start)
    
    threads.append(t)
    threads.append(t1)
    
    for thread in threads:
        thread.start()
    
    for thread in threads:
        thread.join()

我的主题每 5 分钟发送一次数据。

当我使用上面的代码时，它不能正常工作，有时它会发送数据有时它不会。

但是当我使用一个没有 thread 的主题时，它可以正常工作，并且数据每 5 分钟就会完美地输入一次。

我该如何解决这个问题？我想同时订阅两个主题。

我将 Paho 用于 MQTT

我的订阅课程是

class Subscribe:

    def __init__(self, username, passowrd, topic, host, port):

        self.username = username
        self.password = passowrd
        self.topic = topic
        self.host = host
        self.port = port
       
      

    def start(self):
        self.mqttc = mqtt.Client(client_id="Python")
        self.connected = False
        self.mqtt_message = ""
        self.mqttc.username_pw_set(self.username, self.password)
        self.mqttc.on_connect = self.on_connect
        self.mqttc.on_message = self.on_message
        self.mqttc.connect(self.host, self.port)
        self.mqttc.loop_forever()

    def on_message(self, client, userdata, message):
        """
        Fetch data when data coming to Broker
        """
        topic = message.topic
        m = json.loads(message.payload.decode("utf-8"))
        print(m)

   


    def on_connect(self, client, userdata, flags, rc):
        if rc == 0:
            print("Connected to broker", self.topic)
            self.mqttc.subscribe(self.topic)
            self.connected = True

        else:
            print("could not connect", self.topic)

Answer 1

我必须为Client 的两个实例提供两个不同的client_ids，它解决了这个问题。