Question

I have some issues with the requestLoop methode of the Pyro4.Daemon object.

What I want is to call remotely a “stop()” method for releasing the requestLoop function and shutdown my daemon.

This small exemple doesn’t work

SERVER

#!/usr/bin/python
# -*- coding: utf-8 -*-
from daemon import Pyro4

class Audit(object):
    def start_audit(self):
        with Pyro4.Daemon() as daemon:
            self_uri = daemon.register(self)
            ns = Pyro4.locateNS()
            ns.register("Audit", self_uri)
            self.running = True
            print("starting")
            daemon.requestLoop(loopCondition=self.still_running)
            print("stopped")
            self.running = None

    def hi(self, string):
        print string

    def stop(self):
        self.running = False

    def still_running(self):
        return self.running

def main():

    # lancement de l'auditor
    auditor = Audit()
    auditor.start_audit()

if __name__ == "__main__" :
    main()

CLIENT

import Pyro4

def main():

    with  Pyro4.Proxy("PYRONAME:Audit") as au:
        au.hi("hello")
        au.hi("another hi")
        au.stop()

What I expect is to see the server print “hello” and “another hi” and then shutdown.

But the shutdown doesn’t happen, the server is still blocked in the requestloop method.
I can use my proxy as long as I want.

BUT, if I create another client, at the first remote call, the server will shutdown and the client will throw an error:

Pyro4.errors.ConnectionClosedError: receiving: not enough data

All my test are saying that I need to create a 2nd proxy and throw the exeption for pass the requestloop on my server.

Does any one have a idea of how to clean this issue ?

Answer 1

If you look at the examples/callback/client.py in the sources you’ll see the following comment:

# We need to set either a socket communication timeout,
# or use the select based server. Otherwise the daemon requestLoop
# will block indefinitely and is never able to evaluate the loopCondition.
Pyro4.config.COMMTIMEOUT=0.5

Hence, you need to do is set the COMMTIMEOUT in your server file and it will work fine according to my tests.

Note: You can also add a print statement to the still_running method to check when it’s being called. Without the configuration above, you’ll see that it looks like the method is executed only when a new event is received, so the server doesn’t shutdown after the next event to the one that set running to False is received. For example, if you execute the client program twice, the server will shutdown.