From: sandmann AT clio DOT rice DOT edu (Charles Sandmann)
Message-Id: <10304300248.AA20730@clio.rice.edu>
Subject: Re: uclock proposed patch
To: djgpp-workers AT delorie DOT com
Date: Tue, 29 Apr 2003 21:48:50 -0500 (CDT)
In-Reply-To: <3EAEE6FE.5603E13F@phekda.freeserve.co.uk> from "Richard Dawe" at Apr 29, 2003 09:56:30 PM
X-Mailer: ELM [version 2.5 PL2]
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Reply-To: djgpp-workers AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: djgpp-workers AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com
Precedence: bulk

> If you want high precision, I guess you also want it to be non-flakey. My
> feeling is that no high precision would be better than flakey high precision.
> Perhaps we could add YADO (Yet Another Documented Option) to let the user
> choose?

If you take the delta of two utime values, it will usually be correct.
Sometimes it's wrong by 65536 utics.  If you know that, flakey is better
than no precision.  If you want no precision, just use the timer tic.
I'd prefer just to document it, and let the user decide.  We currently
don't indicate it's flakey in the documentation.

I was considering making the double multiplier public; from it you can
easily compute the CPU frequency.  But that would only work for 
Windows NT/2000/XP systems ...