[tsharju]

Hi,

I've been wondering the behavior of socket.py for some time now. I've created a application that uses TCP socket and every now and then the socket dies and prints something like "socket.error, Broken pipe". I know that this is probably work of an evil mobile operator, but my problem is that current socket.py implementation only prints that error and does not raise an exception. So I cannot handle this situation in my application at all to e.g., re-open the socket once this happens.

This is the code in socket.py that does this... I've noticed the problem only with the receive callback starting from line 371.

    def _recv_callback(self,data):
        if isinstance(data,tuple):
            print "error %s %s"%data
            self._seterror(data)
            return
        self._recvbuf += data
        self._recv_callback_pending=False
        if self._recv_listener:
            t=self._recv_listener
            self._recv_listener=None
            t()

Instead of just printing the error and returning it should do something like this.

    def _recv_callback(self,data):
        if isinstance(data,tuple):
            print "error %s %s"%data
            self._seterror(data)
            raise self._error[0],self._error[1]
        self._recvbuf += data
        self._recv_callback_pending=False
        if self._recv_listener:
            t=self._recv_listener
            self._recv_listener=None
            t()

I tested this on my application and it works. I don't know if this affects on behavior of some standard Python libraries, but I think it should raise the exception so that the case can be handled.

Should I file a bug report?

Regards,

Teemu

[jplauril]

Yes, there is a bug. I took a look at socket.py and it indeed fails to raise an exception in a particular case. Your fix is not correct, though. The exception can't be raised in that callback, but instead it must be raised in .recv() using _checkerror().

Could you post the code you are using? It could be useful as a test case.

We'll fix this, thanks for noticing.

[tsharju]

Originally Posted by jplauril

Could you post the code you are using? It could be useful as a test case.

Well, my application has grown to be quite large and is not probably that suitable for this purpose. I'm using jabber.py library available from http://jabberpy.sourceforge.net/.

Here is the part from xmlstream.py that causes the problem. I use select and then I have callback that is called when the connection breaks.

    def process(self, timeout=0):
        """Receives incoming data (if any) and processes it.
           Waits for data no more than timeout seconds."""
        try:
            if select([self._reader],[],[],timeout)[0]:
                data = self.read()
                if data == '':
                    return len(data)
                self._parser.Parse(data)
                return len(data)
            return 0     # Zero means that nothing received but link is alive.
        except:
            self.DEBUG("xmlstream read threw error", DBG_CONN_ERROR)
            self.disconnected(self)

    def disconnected(self,conn):
        """Called when a Network Error or disconnection occurs."""
        try: self.disconnectHandler(conn)
        except TypeError: self.disconnectHandler()

So basically I loop process() and if it fails it calls the disconnected() callback. Currently it does not raise any exceptions, but it only prints the error. So it is the select() that should raise the exception in this case. Hopefully this provides some help.

- Teemu