python multiprocessing socket server example

client.py

import socket

if __name__ == "__main__":
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect(("localhost", 9000))
    data = "some data"
    sock.sendall(data)
    result = sock.recv(1024)
    print result
    sock.close()

server.py

import multiprocessing
import socket

def handle(connection, address):
    import logging
    logging.basicConfig(level=logging.DEBUG)
    logger = logging.getLogger("process-%r" % (address,))
    try:
        logger.debug("Connected %r at %r", connection, address)
        while True:
            data = connection.recv(1024)
            if data == "":
                logger.debug("Socket closed remotely")
                break
            logger.debug("Received data %r", data)
            connection.sendall(data)
            logger.debug("Sent data")
    except:
        logger.exception("Problem handling request")
    finally:
        logger.debug("Closing socket")
        connection.close()

class Server(object):
    def __init__(self, hostname, port):
        import logging
        self.logger = logging.getLogger("server")
        self.hostname = hostname
        self.port = port

    def start(self):
        self.logger.debug("listening")
        self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.socket.bind((self.hostname, self.port))
        self.socket.listen(1)

        while True:
            conn, address = self.socket.accept()
            self.logger.debug("Got connection")
            process = multiprocessing.Process(target=handle, args=(conn, address))
            process.daemon = True
            process.start()
            self.logger.debug("Started process %r", process)

if __name__ == "__main__":
    import logging
    logging.basicConfig(level=logging.DEBUG)
    server = Server("0.0.0.0", 9000)
    try:
        logging.info("Listening")
        server.start()
    except:
        logging.exception("Unexpected exception")
    finally:
        logging.info("Shutting down")
        for process in multiprocessing.active_children():
            logging.info("Shutting down process %r", process)
            process.terminate()
            process.join()
    logging.info("All done")

is this working? I'm having ERROR:root:Unexpected exception saying process.start() is starting the issue. It's been said passing socket to another process is not trivial thing.

what exactly the program does??

tks,

Thank you for the code

It seems this code will not run under windows because multiprocessing.Process can not using os.fork(), you have to use multiprocessing.reduction to pass socket between processes.