Question

I’m using autobahn 0.4.10 (https://github.com/oberstet/Autobahn) as a WebSocket server to send messages to a Google Chrome Extension. I am able to open and close connections using WebSocket(), but when I call autobahn.websocket.WebSocketServerProtocol.sendMessage() the message appears to be sent but isn’t delivered until the connection is closed.

The api for WebSocketServerProtocol’s sendMessage() (derived from WebSocketProtocol) can be found here: http://www.tavendo.de/autobahn/doc/python/websocketprotocol.html#autobahn.websocket.WebSocketProtocol

Has anyone experienced this problem before?

The code I have been on the client side is (js):

ws = new WebSocket('ws://localhost:4444');
ws.onmessage = function(event) {
  console.log('hii');
}

And on the server (python)…

#json is a string object
def sendEvent(self, json):
    print 'to', self.peerstr
    self.sendMessage(json, sync=True)

Both Autobahn and my version of Chrome (17.0.963.46) appear (from what I’ve gotten out of the headers and docs) to use version 13 of the WebSocket draft protocol.

Answer 1

Turns out this was a threading problem with some threads block the twisted reactor.

See:
http://groups.google.com/group/autobahnws/browse_thread/thread/6bf0c43ec169efc3#
http://twistedmatrix.com/documents/current/core/howto/threading.html