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

[Peter Schneider-Kamp]

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