Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!sjsca4!greg
From: greg@sj.ate.slb.com (Greg Wageman)
Newsgroups: comp.sys.atari.st
Subject: Re: timer
Message-ID: <1990Jan16.013746.5148@sj.ate.slb.com>
Date: 16 Jan 90 01:37:46 GMT
References: <6667@wpi.wpi.edu>
Reply-To: greg@sj.ate.slb.com (Greg Wageman)
Distribution: usa
Organization: Schlumberger ATE, San Jose, CA 95110
Lines: 23

Opinions expressed are the responsibility of the author.

In article <6667@wpi.wpi.edu> jstorey@wpi.wpi.edu (John R Storey) writes:
>I'm writing a C program and have a small problem - I want to time how long
>a call to the Random ( ) XBIOS function.  The problem is that I can't figure
>out how to time it in increments smaller than 2 seconds.  

You don't say which compiler you're using, so this may not apply to
you.  Mark Williams C provides a function called "clock()", which
returns the number of clock ticks since the system was booted.  The
constant CLK_TCK encodes the number of ticks/second.

It so happens that the clock() functions uses the 200hz system timer,
so if you save the value returned by clock() (an unsigned LONG) before
and after the Random() call, and difference them, you will get the
number of clock ticks elapsed, more or less.  Integer division by
CLK_TCK will give you elapsed time in seconds; modulo CLK_TCK gives
you the remainder in 5-millisecond ticks.

Copyright 1990 Greg Wageman	DOMAIN: greg@sj.ate.slb.com
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