Strange traceback with WebSocket.send

[vincent-lg]

I use ws4py with Cherrypy (the plugin and the tool provided).

It works just fine most of the time, but sometimes I have in my log a traceback like that. I didn't remove any line from it, more explanations are given below:

Exception in thread WebSocket client at _..**.**_:56741:
Traceback (most recent call last):
File "/usr/local/lib/python3.3/threading.py", line 639, in _bootstrap_inner
self.run()
File "/usr/local/lib/python3.3/threading.py", line 596, in run
self._target(_self._args, *_self._kwargs)
File "/usr/local/lib/python3.3/site-packages/ws4py-0.2.5-py3.3.egg/ws4py/websocket.py", line 291, in run
if not process(bytes):
File "/usr/local/lib/python3.3/site-packages/ws4py-0.2.5-py3.3.egg/ws4py/websocket.py", line 343, in process
self.received_message(s.message)
File "/home/vlegoff/pa-poc2/scripts/../plugins/websocket/handler.py", line 86, in received_message
function(**args)
File "/home/vlegoff/pa-poc2/scripts/../bundles/chat/websockets/chat.py", line 32, in handle_setpseudo
self.send_to_connected(welcome, self)
File "/home/vlegoff/pa-poc2/scripts/../bundles/chat/websockets/chat.py", line 58, in send_to_connected
ws_handler.send_message(message, escape=escape)
File "/home/vlegoff/pa-poc2/scripts/../bundles/chat/websockets/chat.py", line 69, in send_message
self.send_JSON("message", message=message)
File "/home/vlegoff/pa-poc2/scripts/../plugins/websocket/handler.py", line 110, in send_JSON
self.send_text(text)
File "/home/vlegoff/pa-poc2/scripts/../plugins/websocket/handler.py", line 101, in send_text
self.send(msg)
File "/usr/local/lib/python3.3/site-packages/ws4py-0.2.5-py3.3.egg/ws4py/websocket.py", line 219, in send
message_sender = self.stream.binary_message if binary else self.stream.text_message
AttributeError: 'NoneType' object has no attribute 'text_message'

The almost last lines are part of my application: I have a WebSocketHandler (the Chat class inherited from WebSocket defined in ws4py). The goal is to send a message to one of the connected client and it finally crashes on the WebSocket.send method.

Do you know why this happens and how to fix it? Is it a ws4py bug or a wrong usage in my application?

[Lawouach]

That's weird. It looks like the stream attribute was reset to None which is only done during cleanup once the websocket has been closed. Are you using it after it was closed?

[vincent-lg]

Sorry, actually it was my application's fault: WebSocket were kept alive even after their disconnection, and when I tried to send a message to them... it crashed.

Sorry about that. Maybe you could send a more explicit error message (or exception) when trying to send a message to a closed connection.

[Lawouach]

Indeed, ws4py should. I'll try to make it more explicit.

[meawoppl]

This one bit me too. Pretty hard to figure out what happened . . . This seems to occur whenever you send to a terminated ws.

[vincent-lg]

Yes, I thought I sent you a note about it but apparently didn't. The
bug was simply caused because I had closed the websocket (the
traceback is not that explicit, but the mistake is definitely minde).

2013/5/13, Matty G notifications@github.com:

This one bit me too. Pretty hard to figure out what happened . . . This
seems to occur whenever you send to a terminated ws.

---

Reply to this email directly or view it on GitHub:
#73 (comment)