lkml.org 
[lkml]   [2002]   [Jul]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] 'select' failure or signal should not update timeout
Rusty Russell wrote:
>
> On Wed, 24 Jul 2002 11:48:10 -0700 (PDT)
> Linus Torvalds <torvalds@transmeta.com> wrote:
>
> > The thing is, we cannot change existing select semantics, and the
> > question is whether what most soft-realtime wants is actually select, or
> > whether people really want a "waittimeofday()".
>
> NOT waittimeofday. You need a *new* measure which can't be set forwards
> or back if you want this to be sane. pthreads has absolute timeouts (eg.
> pthread_cond_timedwait), but they suck IRL for this reason.
>
> Of course, doesn't need any correlation with absolute time, it could be a
> "microseconds since boot" kind of thing.
>
The POSIX clocks & timers API defines CLOCK_MONOTONIC for
this sort of thing (CLOCK_MONOTONIC can not be set). It
also defines an API for clock_nanosleep() that CAN use an
absolute time which is supposed to follow any clock setting
that is done. Combine the two and you have a fixed time
definition.

AND, guess what, the high-res-timers patch does all this and
more.
--
George Anzinger george@mvista.com
High-res-timers:
http://sourceforge.net/projects/high-res-timers/
Real time sched: http://sourceforge.net/projects/rtsched/
Preemption patch:
http://www.kernel.org/pub/linux/kernel/people/rml
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:27    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site