Message from discussion Getting "absolute time" in Linux

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From: malc <m...@pulsesoft.com>
Newsgroups: comp.os.linux.development.system
Subject: Re: Getting "absolute time" in Linux
Date: Tue, 14 Nov 2006 23:42:09 +0000 (UTC)
Organization: Comcor-TV
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Boris Benenson <boris.benen...@marconi.com> writes:

> Is there a way in either standard or Real-time Linux to get "absolute
> number of ticks (or seconds) since the Epoc (or some other
> configurable starting point), regardless of the kernel clock resets
> via settimeofday() and the RTC resets via hwclock set and regardless
> of the system reboots?

http://www.opengroup.org/onlinepubs/000095399/functions/clock_gettime.html
CLOCK_MONOTONIC

`man clock_gettime' on this Linux box says:

AVAILABILITY
       On  POSIX  systems on which these functions are available,
       the symbol _POSIX_TIMERS is defined  in  <unistd.h>  to  a
       value greater than 0.  The symbols _POSIX_MONOTONIC_CLOCK,
       _POSIX_CPUTIME,   _POSIX_THREAD_CPUTIME   indicate    that
       CLOCK_MONOTONIC,                 CLOCK_PROCESS_CPUTIME_ID,
       CLOCK_THREAD_CPUTIME_ID   are   available.    (See    also
       sysconf(3).)


Availablility of CLOCK_MONOTONIC is system (and not just libc)
specific (for instance stock Linux 2.4 kernels do not have it,
2.6 do)

--
vale