python 多进程队列数据处理

# -*- coding:utf8 -*-
import paho.mqtt.client as mqtt
from multiprocessing import Process, Queue
import time, random, os
import camera_person_num

MQTTHOST = "172.19.4.4"
MQTTPORT = 1883
mqttClient = mqtt.Client()
q = Queue() 

# 连接MQTT服务器
def on_mqtt_connect():
    mqttClient.connect(MQTTHOST, MQTTPORT, 60)
    mqttClient.loop_start()

# 消息处理函数
def on_message_come(lient, userdata, msg):
    # print(msg.topic + ":" + str(msg.payload.decode("utf-8")))

    q.put(msg.payload.decode("utf-8"))  # 放入队列
    print("产生消息", msg.payload.decode("utf-8"))
    # 消息处理开启多进程
    # p = Process(target=talk, args=("/camera/person/num/result", msg.payload.decode("utf-8")))
    # p.start()

def consumer(q, pid):
    print("开启消费序列进程", pid)
    while True:
        msg = q.get()
        # p = Process(target=talk, args=("/camera/person/num/result", msg, pid))
        # p.start()
        talk("/camera/person/num/result", msg, pid)  

# subscribe 消息订阅
def on_subscribe():
    mqttClient.subscribe("test123", 1)  # 主题为"test"
    mqttClient.on_message = on_message_come  # 消息到来处理函数

# publish 消息发布
def on_publish(topic, msg, qos):
    mqttClient.publish(topic, msg, qos);

# 多进程中发布消息需要重新初始化mqttClient
def talk(topic, msg, pid):
    cameraPsersonNum = camera_person_num.CameraPsersonNum(msg)
    t_max, t_mean, t_min = cameraPsersonNum.personNum()
    # time.sleep(20)
    print("消费消息", pid, msg)
    mqttClient2 = mqtt.Client()
    mqttClient2.connect(MQTTHOST, MQTTPORT, 60)
    mqttClient2.loop_start()
    mqttClient2.publish(topic, '{"max":' + str(t_max) + ',"mean":' + str(t_mean) + ',"min:"' + t_min + '}', 1)
    mqttClient2.disconnect()

def main():

    on_mqtt_connect()
    on_subscribe()
    for i in range(1, 3):
        c1 = Process(target=consumer, args=(q, i))
        c1.start()
    while True:
        pass

if __name__ == '__main__':
    main()