Run Web Socket in a separate thread

[martinsik]

Hi, I'm trying to run Web Socket server in another thread while being able to send messages to clients:

clients = []
class SimpleChat(WebSocket):

    def handleMessage(self):
       for client in clients:
          if client != self:
             client.sendMessage(self.address[0] + ' - ' + self.data)

    def handleConnected(self):
       print self.address, 'connected'
       for client in clients:
          client.sendMessage(self.address[0] + u' - connected')
       clients.append(self)

    def handleClose(self):
       clients.remove(self)
       print self.address, 'closed'
       for client in clients:
          client.sendMessage(self.address[0] + u' - disconnected')

def run_server():
    server = SimpleWebSocketServer.SimpleWebSocketServer('', 9000, SimpleChat)
    server.serveforever()

t = threading.Thread(target=run_server)
t.start()

while True:
    for client in clients:
        client.sendMessage('ping')
    time.sleep(1)

It doesn't seem to be sending any messages. Is it because the loop is blocking the main thread? Is there any better way to do it?

[dpallot]

Specify the selectInterval parameter on the init function of SimpleWebSocketServer (maybe 1 sec). If its not set then the blocking select will not be waiting on the descriptor unless the endpoint sends some data. Note that the above code is not thread safe with the current implementation.

[martinsik]

Thanks, selectInterval helped. Can you give me just brief info why is this happening? Is it because the while True loop blocks the main thread instead of SimpleWebSocketServer so messages are queued but never actually sent?

[dylancaponi]

What exactly is selectInterval doing? Why is this not thread safe?