如何让消费者并发消费？

def createConsumer():
consumer = PushConsumer(gid) # 指定group-id
consumer.set_namesrv_addr(name_srv) # rocketmq队列接口地址（服务器ip:port)
consumer.subscribe(topic, callback) # 订阅
consumer.start() # 开启
if __name__=='__main__':
print('Parent process %s.' % os.getpid())
for i in range(5):
p = Process(target=createConsumer)
print('Run child process (%s)...' % (os.getpid()))
p.start()
while True:
time.sleep(3600)
为什么我写了多进程的消费程序，但是却并不执行