Run WebSocket server in Thread

Question

this is probably more a question about threading than about my websocket. I'm using "SimpleWebSocket" from github ( https://github.com/dpallot/simple-websocket-server ) The example works fine:

from SimpleWebSocketServer import SimpleWebSocketServer, WebSocket

class SimpleEcho(WebSocket):

    def handleMessage(self):
        # echo message back to client
        self.sendMessage(self.data)

    def handleConnected(self):
        print self.address, 'connected'

    def handleClose(self):
        print self.address, 'closed'

server = SimpleWebSocketServer('', 8000, SimpleEcho)
server.serveforever()

The Server is running, I can connect and send Messages.

Now i try to run it as a Thread with those classes: This one is supposed to create many threads including the WebSocketServer

from websockethread import WebSocketThread
class startManyThreads:
    def __init__(self):
        self.thread1 = WebSocketThread()
        self.thread1.start()

if __name__ == "__main__":
    startManyThreads = startManyThreads()

This class should run as my thread:

import threading
from SimpleWebSocketServer import SimpleWebSocketServer
from webSocketServer import WebSocketServer

class WebSocketThread(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)
        server = SimpleWebSocketServer('', 8000, WebSocketServer)
        server.serveforever()

And this is the "customized" echo example:

from SimpleWebSocketServer import SimpleWebSocketServer, WebSocket

class SimpleEcho(WebSocket):

    def handleMessage(self):
        # echo message back to client
        self.sendMessage(self.data)

    def handleConnected(self):
        print self.address, 'connected'

    def handleClose(self):
        print self.address, 'closed'

I have also tried to derive this: class SimpleEcho(WebSocket, threading.Thread):

Any Ideas what i'm doing wrong? & Thanks alot in advance!

Edit: The result when i run "simpleEcho" is that i get a prompt can connect via the websocket.html (provided on github), send and receive Messages

The result when i put it in a thread (anyone of the 3 ways i tried) is the same behaviour except when i try to "connect" from the websocket.html i get a "error: undefined". With nmap i checked and the Server seems so be running & listening to port 8000

Edit 2: Derived new Class from SimpleWebSocketServer

import threading

from SimpleWebSocketServer import SimpleWebSocketServer

class ThreadSimpleWebSocketThread(threading.Thread, SimpleWebSocketServer):
    def __init__(self, serversocket):
        threading.Thread.__init__(self)
        self.serversocket = serversocket

    def serveforever(self):
        SimpleWebSocketServer.serversocket = self.serversocket
        SimpleWebSocketServer.selectInterval = 0.1
        SimpleWebSocketServer.listeners = [self.serversocket]
        super(ThreadSimpleWebSocketThread, self).serveforever()

    def run(self):
        self.serveforever()

Answer 1

The main problem seems to be where you're starting the server. The Thread.__init__() method runs inside the main thread (of the caller), not the actual WebSocketThread(). This needs to be done in the Thread.run() method:

class WebSocketThread(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)

    def run(self):
        server = SimpleWebSocketServer('', 8000, WebSocketServer)
        server.serveforever()

The code inside run() actually runs inside the thread.

Note that because of the Global Interpreter Lock, threads won't improve performance much, and you'll probably need multiprocessing. However, if you just want to offload the I/O waiting, this should work fine.

Edit: From looking at this GitHub project, and rethinking what you're trying to do, this isn't trivial. You'll have to override WebSocket.serveforever() in your SimpleEcho() class and change it to accept the socket and pass the accepted socket to a Thread (see here).