zmq_cli.py

#!/usr/bin/python
"""
zmq_cli - 0MQ Server interruptability test case, client module.

"""


import zmq


def run(port):
    context = zmq.Context()
    socket = context.socket(zmq.REQ)
    socket.connect("tcp://localhost:%d" % port)
    print "Sending test."
    socket.send("test")
    reply = socket.recv()
    print "Got reply: %s." % repr(reply)
    print "Sending EXIT."
    socket.send("EXIT")
    reply = socket.recv()
    print "Got reply: %s." % repr(reply)
    socket.close()
    context.term()


if __name__ == "__main__":
    run(54321)

zmq_serv.py

#!/usr/bin/python
"""
zmq_serv - 0MQ Server interruptability test case.

Symptoms: The server does not stop immediately when I try to interrupt
it with ^C.  If I subsequently send data to it from a client, the
server does stop with a KeyboardInterrupt exception at
'self.socket.recv()'.

This test case does seem to respect SIGTERM from outside, such as from
the 'kill' command.

"""

import zmq
import time
import sys


class Server(object):
    """
    Simple 0MQ REQ/REP server.  It replies to messages, and stops when
    it gets the "EXIT" message.

    """
    def __init__(self, port):
        self.port = port
        self.context = zmq.Context()

    def run(self):
        """
        Run the REQ/REP server.

        """
        self.socket = self.context.socket(zmq.REP)
        self.socket.bind("tcp://*:%d" % self.port)
        print "Listening for messages."
        while True:
            message = self.socket.recv()
            print "Received %d bytes." % len(message)
            try:
                reply = self.handle(message)
                self.socket.send(reply)
            except Exception as e:
                self.socket.send("ERROR: %s." % str(e))

    def handle(self, message):
        """
        Handle the incoming message.  Return an appropriate reply.

        """
        if message == "EXIT":
            self.stop()
        return "Hello, %s!" % message

    def stop(self):
        """
        Stop the server, terminating the 0MQ context.

        """
        self.socket.send('EXITING')
        self.socket.close()
        self.context.term()
        sys.exit(0)


if __name__ == "__main__":
    s = Server(54321)
    s.run()