zeromq req rep xrep xreq queue实现队列

参考： https://learning-0mq-with-pyzmq.readthedocs.io/en/latest/pyzmq/devices/queue.html
1）queue_device.py

import zmq

def main():
    try:
        context = zmq.Context(1)
        # Socket facing clients
        frontend = context.socket(zmq.XREP)
        frontend.bind("tcp://*:5559")
        # Socket facing services
        backend = context.socket(zmq.XREQ)
        backend.bind("tcp://*:5560")

        zmq.device(zmq.QUEUE, frontend, backend)
    except Exception as e:
        print (e)
        print ("bringing down zmq device")
    finally:
        pass
        frontend.close()
        backend.close()
        context.term()

if __name__ == "__main__":
    main()

2）queue_server.py

import zmq
import time
import sys
import random

port = "5560"
context = zmq.Context()
socket = context.socket(zmq.REP)
socket.connect("tcp://localhost:%s" % port)
server_id = random.randrange(1,10005)

while True:
    #  Wait for next request from client
    message = socket.recv()
    print ("Received request: ", message)
    time.sleep (1)
    socket.send( ("World from server %s" % server_id).encode('ascii') )

3）queue_client.py

import zmq
import sys
import random

port = "5559"
context = zmq.Context()
print( "Connecting to server...")
socket = context.socket(zmq.REQ)
socket.connect ("tcp://localhost:%s" % port)
client_id = random.randrange(1,10005)

#  Do 10 requests, waiting each time for a response
for request in range (1,10):
    print( "Sending request ", request,"..." )
    socket.send ( ("Hello from %s" % client_id).encode('ascii') )
    #  Get the reply.
    message = socket.recv()
    print ("Received reply ", request, "[", message, "]")

#python3 queue_device.py
#python3 queue_server.py
#python3 queue_server.py
#python3 queue_client.py
#python3 queue_client.py