How do I reconnect a disconnected socket?

Jason Kristoff

I'm trying to make something that once it is disconnected will
automatically try to reconnect. I'll add some more features in later so
it doesn't hammer the server but right now I just want to keep it simple
and get that part working. The problem is that when I use sock.close I
get an error message of
Bad File Descriptor
and if I either use shutdown or just go straight to reconnecting I get:
Transport endpoint is already connected

This is what I've got right now:

#! /usr/bin/env python
import socket, string
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
def doconn():
sock.connect(("localhost", 1234))
def dodiscon():
sock.close()
doconn()

doconn()

while (1):
buffer = sock.recv(1024)
if not buffer:
dodiscon()

Mar 28 '08 #1

pianomaestro

Did you try just creating a new socket every time you do a connect ?

On Mar 28, 10:01 am, Jason Kristoff <deevine-removethis-
s...@gmail.comwrote:

I'm trying to make something that once it is disconnected will
automatically try to reconnect. I'll add some more features in later so
it doesn't hammer the server but right now I just want to keep it simple
and get that part working. The problem is that when I use sock.close I
get an error message of
Bad File Descriptor
and if I either use shutdown or just go straight to reconnecting I get:
Transport endpoint is already connected

This is what I've got right now:

#! /usr/bin/env python
import socket, string
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
def doconn():
sock.connect(("localhost", 1234))
def dodiscon():
sock.close()
doconn()

doconn()

while (1):
buffer = sock.recv(1024)
if not buffer:
dodiscon()

Mar 28 '08 #2

Laszlo Nagy

This is what I've got right now:

#! /usr/bin/env python
import socket, string
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
def doconn():
sock.connect(("localhost", 1234))
def dodiscon():
sock.close()
doconn()

doconn()

while (1):
buffer = sock.recv(1024)
if not buffer:
dodiscon()

sock.recv(1024) can return zero bytes of data indicating that no data
arrived yet. It does not mean that you have been disconnected. This is
especially true when you do nothing but recv, recv, recv() in an
infinite loop.

I recommend that you use select.select to see if there is some data that
can be read. Call socket.recv() only when you know that it will not fail.

Best,

Laszlo

Mar 28 '08 #3

Mike

On Mar 28, 10:01 am, Jason Kristoff <deevine-removethis-
s...@gmail.comwrote:

I'm trying to make something that once it is disconnected will
automatically try to reconnect. I'll add some more features in later so
it doesn't hammer the server but right now I just want to keep it simple
and get that part working. The problem is that when I use sock.close I
get an error message of
Bad File Descriptor
and if I either use shutdown or just go straight to reconnecting I get:
Transport endpoint is already connected

This is what I've got right now:

#! /usr/bin/env python
import socket, string
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
def doconn():
sock.connect(("localhost", 1234))
def dodiscon():
sock.close()
doconn()

doconn()

while (1):
buffer = sock.recv(1024)
if not buffer:
dodiscon()

I'd recommend to look at Twisted ReconnectingClientFactory -
http://twistedmatrix.com/trac/browse...otocol.py#L198

Mar 28 '08 #4