Re: recv() timeout problem

[Corinna Vinschen <corinna-cygwin@cygwin.com>]

On Jul  5 13:41, David Stacey wrote:
> On 05/07/13 10:00, Corinna Vinschen wrote:
> >On Jul  4 19:34, David Stacey wrote:
> >>>Please find attached a short programme that demonstrates a problem
> >>>I'm having with recv() timeouts. Under Fedora 19 x64, the test
> >>>programme times out after three seconds (which is the desired
> >>>behaviour). However, when run from Cygwin, the call to recv() never
> >>>exits.
> >>>
> >>>I am using the latest snapshot (2013-07-03) in 32-bit Cygwin. OS is
> >>>Windows 7 Ultimate x64 SP1.
> >>>
> >>>Many thanks in advance for your help,
> >Unfortunately that won't work at the moment.
> >
> >The underlying implementation of recv is nonblocking.  A blocking
> >Windows recv call is noninterruptible, unfortunately (at least up to
> >Windows 2003), so this was necessary to handle signals or
> >thread-cancellation.
> >
> >Due to its nonblocking nature under the hood, this doesn't support
> >SO_RCVTIMEO and SO_SNDTIMEO and, surprisingly, we never had a complaint
> >about that, despite its age.
> >
> >I can't promise a quick solution, but I put implementing handling of
> >SO_RCVTIMEO and SO_SNDTIMEO in recv/send on my TODO list.  Of course,
> >patches are welcome, too.
> >
> >For the time being, I suggest to use select or poll with timeout
> >instead.
> 
> Thank you for your e-mail, and for replying so quickly. Regarding
> the recv() timeouts: no problem, it's easy enough to work around. On
> your TODO list, file this one under things to do when you've finally
> got that cat.

LOL.  Nah, it's an interesting little problem, I'm pretty sure I'll
have a look later this month.

> I think that's the last of my Poco problems out of the way. I'll
> give it a clean build and test, and send an ITP either this evening
> or tomorrow.
> 
> Thanks once again for your help,

No worries.  And thanks for the testcase, I'm sure I'll use it to test
the SO_RCVTIMEO implementation when I get to it.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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