[Python-Dev] Adding timeout to socket.py and httplib.py (original) (raw)

Facundo Batista facundo at taniquetil.com.ar
Tue Mar 20 15:45:55 CET 2007

Alan Kennedy wrote:

I see that your updated socket.connect() method takes a timeout parameter, which defaults to None if not present, e.g.

I did NOT update a connect() method. I created a connect() function, in the module socket.py (there's also a connect() method in the socket object, but I didn't touch it).

import socket ; socket.setdefaulttimeout(10.0)

how do I restore full blocking behaviour to a single socket? (a somewhat contrived case, I admit).

You can not, unless you have access to the socket object itself.

If I have access to the socket object, then I can call "sockobj.settimeout(None)", but in that case I don't need the new API. I could also do it with the call "sockobj.setblocking(1)".

Exactly.

If I don't have access to the socket object, i.e. I'm using timeouts indirectly through httplib/etc, then I'm stuck: there's no way I can change the blocking or timeout behaviour; back to square one.

No. This method is for easily do that job from higher level libraries. The code that is in my patch, it's right now copied N times in higher level libraries (httplib, ftplib, smtplib, etc).

In all those libraries, the socket is opened, used, and never changed the state between non-blocking, timeout, and nothing.

Experience (personal and complains in mailing lists) shows that a timeout is needed: a lot of times people wants to make urllib2.urlopen(....., timeout=10), for example.

But never heard of anybody wanting to "go to timeout" and then "back to blocking mode", with the same socket, using high level libraries.

So the new proposed API partly addresses the problem of increasing control over the underlying socket, but doesn't address all cases. It specifically prevents setting a timeout value of None on a socket, which is an important use case, I think.

False. If you want to set a timeout value of None on a socket, you surely can, I haven't touch any line of code in socket-the-object!

Regards,

-- . Facundo . Blog: http://www.taniquetil.com.ar/plog/ PyAr: http://www.python.org/ar/

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