Multithreading and ZMQ DEALER/REP hello world doesn't work

问题

First of all my code (largely inspired from ZMQ doc http://zguide.zeromq.org/py:mtserver):

import zmq
import time
import sys
import threading

#SOCKET_NAME = "tcp://127.0.0.1:8000"
SOCKET_NAME = "inproc://mysocket"

def dealerRoutine(context):
    socket = context.socket(zmq.DEALER)
    socket.bind(SOCKET_NAME)
    time.sleep(12)
    socket.send("hello")
    socket.send("hello")
    print socket.recv()
    print socket.recv()
    socket.close()


def workerRoutine(context):
    socket = context.socket(zmq.REP)
    socket.connect(SOCKET_NAME)
    s = socket.recv()
    print s
    socket.send("world")

context = zmq.Context()

workers = []
for i in range(0, 2):
    worker = threading.Thread(target=workerRoutine, args=([context]))
    workers.append(worker) 
    worker.start()

dealerRoutine(context)

for worker in workers:
    worker.terminated = True

context.term()

I've tried this code with both inproc and tcp sockets.

inproc gives an error when workers try to connect
TCP just waits after the send on the dealer, no print appears from worker, no other message is received on dealer
I've thought of the slow joiner problem and add a sleep (one before the workers to connect, and one before dealer's send()) : that just causes the inproc to behave the same as TCP does.

PS : I'm sorry for camelCase but I'm addicted to it.

回答1:

I made it work by:

for the dealer, sending your message in multipart, the first part being an empty message, the second part being your message
reduced the timer (that one didn't help though)

Here is the code:

import zmq
import time
import sys
import threading

SOCKET_NAME = "tcp://127.0.0.1:8000"
#SOCKET_NAME = "inproc://mysocket"

def dealerRoutine(context):
    socket = context.socket(zmq.DEALER)
    socket.bind(SOCKET_NAME)
    time.sleep(1)
    socket.send("", zmq.SNDMORE)
    socket.send("hello")
    socket.send("", zmq.SNDMORE)
    socket.send("hello")
    print socket.recv()
    print socket.recv()
    socket.close()


def workerRoutine(context):
    socket = context.socket(zmq.REP)
    socket.connect(SOCKET_NAME)
    s = socket.recv()
    print s
    socket.send("world")

context = zmq.Context()

workers = []
for i in range(0, 2):
    worker = threading.Thread(target=workerRoutine, args=([context]))
    workers.append(worker) 
    worker.start()

dealerRoutine(context)

for worker in workers:
    worker.terminated = True

context.term()

来源：https://stackoverflow.com/questions/12915982/multithreading-and-zmq-dealer-rep-hello-world-doesnt-work

标签

python

zeromq

pyzmq