Re: Nanoseconds precision

["Håkon Hallingstad" <hakon@ion.no>]

Or you may use the "rdtsc" (Read Time Stamp Counter) assembly instruction.

On Thu, Aug 25, 2005 at 03:37:27PM +0200, Steve Graegert wrote:
> On 8/25/05, Ronaldo.Afonso@cyclades.com <Ronaldo.Afonso@cyclades.com> wrote:
> > 
> > All the functions in the libc do not show me nanosecond's precision. What
> > they do is get a microsecond number and multiply it by 1000. So, I realized
> > that it has to be that way because it's impossible to get a nanosecond's
> > precison on a machine with a 2Ghz clock. The system needs more than a
> > nanosecond to execute an instruction, so any nanosecond's precision, at
> > leas on a 2Ghz machine, should be inaccurate. I'm just sharing what I've
> > found.
> > 
> > Anyway, I'd like to thank everyone who helped me with this question.
> 
> #include <time.h>
> int clock_gettime(clockid_t clock_id, struct timespec *tp);
> 
> timespec.nv_nsec provides nanosecond resolution.  Use CLOCK_REALTIME
> for clock_id.
> 
> Regards
> 
> 	\Steve
> 
> --
> 
> Steve Graegert <graegerts@gmail.com>
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