[Python-Dev] timeout support for socket.py? (was: [ANN] TCP socket timeout module --> timeoutsocket.py) (original) (raw)

Peter Schneider-Kamp nowonder@nowonder.de
Thu, 17 Aug 2000 07:13:08 +0000

As the socketmodule is now exported as _socket and a seperate socket.py file wrapping _socket is now available in the standard library, wouldn't it be possible to include timeout capabilities like in http://www.timo-tasi.org/python/timeoutsocket.py

If the default behaviour would be "no timeout", I would think this would not break any code. But it would give an easy(and documentable) solution) to people who e.g. have their urllib.urlopen("http://spam.org").read() hang on them. (Actually the approach should work for all streaming socket connections, as far as I understand it.)

Are there any efficiency concerns? If so, would it be possible to include a second socket class timeoutsocket in socket.py, so that this could be used instead of the normal socket class? [In this case a different default timeout than "None" could be chosen.]

Peter

P.S.: For your convenience a quote of the announcement on c.l.py, for module documentation (== endlessly long doc string) look in http://www.timo-tasi.org/python/timeoutsocket.py

Timothy O'Malley wrote:

Numerous times I have seen people request a solution for TCP socket timeouts in conjunction with urllib. Recently, I found myself in the same boat. I wrote a server that would connect to skytel.com and send automated pages. Periodically, the send thread in the server would hang for a long(!) time. Yup -- I was bit by a two hour timeout built into tcp sockets. Thus, I wrote timeoutsocket.py With timeoutsocket.py, you can force all TCP sockets to have a timeout. And, this is all accomplished without interfering with the standard python library! Here's how to put a 20 second timeout on all TCP sockets for urllib: import timeoutsock import urllib timeoutsocket.setDefaultSocketTimeout(20) Just like that, any TCP connection made by urllib will have a 20 second timeout. If a connect(), read(), or write() blocks for more than 20 seconds, then a socket.Timeout error will be raised. Want to see how to use this in ftplib? import ftplib import timeoutsocket timeoutsocket.setDefaultSocketTimeout(20) Wasn't that easy! The timeoutsocket.py module acts as a shim on top of the standard socket module. Whenever a TCP socket is requested, an instance of TimeoutSocket is returned. This wrapper class adds timeout support to the standard TCP socket. Where can you get this marvel of modern engineering? http://www.timo-tasi.org/python/timeoutsocket.py And it will very soon be found on the Vaults of Parnassus. Good Luck! -- -- happy daze -tim O -- http://www.python.org/mailman/listinfo/python-list

-- Peter Schneider-Kamp ++47-7388-7331 Herman Krags veg 51-11 mailto:peter@schneider-kamp.de N-7050 Trondheim http://schneider-kamp.de