Messages in this thread | | | From | "Simon Butcher" <> | Subject | RE: Measure time | Date | Thu, 9 May 2002 02:51:42 +1000 |
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Hi,
ftime() will return milliseconds, but it's considered an obsolete function. You could use gettimeofday() (as Richard Johnson suggested) to get microseconds and divide them to get milliseconds, although I don't know how time critical your routines are.
If you're still looking for nanoseconds, I'm told you can use clock_gettime() but it's still quite unavailable (I've never seen it myself, yet).. however even if it was available you possibly wouldn't get a very high resolution from it with current systems..
- Simon
> -----Original Message----- > From: linux-gcc-owner@vger.kernel.org > [mailto:linux-gcc-owner@vger.kernel.org]On Behalf Of Serguei I. Ivantsov > Sent: Thursday, 9 May 2002 01:47 > To: Der Herr Hofrat > Cc: linux-gcc@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: Re: Measure time > > > Is there any function like GetTickCount() in M$ Win32 that > retrieves time in > milliseconds? > > -- > Regards, > Serguei I. Ivantsov > > ----- Original Message ----- > From: "Der Herr Hofrat" <der.herr@mail.hofr.at> > To: "Serguei I. Ivantsov" <administrator@svitonline.com> > Cc: <linux-gcc@vger.kernel.org>; <linux-kernel@vger.kernel.org> > Sent: Wednesday, May 08, 2002 3:00 PM > Subject: Re: Measure time > > > > > Hello! > > > > > > Is there any function for high precision time measuring. > > > time() returns only in second. I need nanoseconds. > > > > > you can directly read the TSC but that will not realy give you > nanoseconds > > resolution as the actual read access even on a PIII/1GHz is > going to take > > up to a few 100 nanoseconds, and depending on what you want to time > > stamp the overall jitter of that code can easaly be in the > > range of a microsecond. > > > > There are some hard-realtime patches to the Linux kernel that will > > allow time precission of aprox. 1us (the TSC has a precission of 32ns) > > but I don't think you can get below that without dedicated hardware. > > > > for RTLinux check at ftp://ftp.rtlinux.org/pub/rtlinux/ > > > > hofrat > > - > To unsubscribe from this list: send the line "unsubscribe linux-gcc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >
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