[PATCH] Multiple timer issues
Corinna Vinschen
corinna-cygwin@cygwin.com
Fri Mar 4 08:59:00 GMT 2016
Artúr,
Ping? Any news on your CA? Did you get my reply to your mail to
ges-info?
Thanks,
Corinna
On Feb 18 12:28, Corinna Vinschen wrote:
> Hi Artúr,
>
> On Feb 17 23:30, Irányossy Knoblauch Artúr wrote:
> > Dear Cygwin Maintainers,
> >
> > First of all, thank you for your work, I really enjoy using this software!
>
> Thank you :)
>
> > However, I have noticed that adjusting the system time can cause some
> > programs to misbehave. I have found bugs in the POSIX timer
> > implementation and a bug in the select() function's timeout handling.
> >
> > Please find the proposed patches attached.
>
> I checked your patches and they look good. I like it that this weird
> priming can go away.
>
> > Regarding POSIX timers:
> >
> > I have also created a small test application (see timer_test.c and the
> > Makefile) to demonstrate the issue. Please try to run it on both Linux
> > and Cygwin!
> >
> > The test tries to set the system time back and forth to see the effect
> > on different kinds of timers. Please note, that for setting the system
> > time, the test has to be run with the necessary administrative rights
> > provided.
> >
> >
> > Regarding select():
> >
> > The timeout shall be immune to adjustments to the system clock in all
> > cases; so the 'gtod' clock shouldn't be used, because it is not
> > monotonic.
> >
> >
> > I have tried to keep the changes as minimal as possible.
> > I hope that signing a legal agreement is not necessary, since these
> > are just bugfixes; if you think otherwise, please let me know.
>
> Patches 2 can go in as trivial, patch 3 too with a little bit of a
> stretch. Unfortunately your first patch is too big to go in as trivial.
> Would you mind terribly to send a copyright assignment per
> https://cygwin.com/contrib.html? If you send it as PDF by mail it takes
> usually just a few days to be countersigned.
>
> I would apply patch 2 immediately, but as far as I can see it relies
> on patch 1. Without patch 1, exchanging gtod with ntod will not change
> anything since it's still a non-monotonic timer. Or am I missing
> something?
>
>
> Thanks a lot,
> Corinna
>
> --
> Corinna Vinschen Please, send mails regarding Cygwin to
> Cygwin Maintainer cygwin AT cygwin DOT com
> Red Hat
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Maintainer cygwin AT cygwin DOT com
Red Hat
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