From:	"Michal Strelec" <strelec AT adam DOT osu DOT cz>
Newsgroups:	comp.os.msdos.djgpp
Subject:	CLOCKS_PER_SEC in DJGPP
Date:	Fri, 6 Aug 1999 11:04:16 +0200
Organization:	Czech Technical University
Lines:	29
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To:	djgpp AT delorie DOT com
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Hi,
In my program I use function clock(), whitch returns number of timer ticks
from the begining of program.
But how many ticks timer do in a seconds in real?
I thought that 18.2, but in source code of communication package (pmcomm) I
found
****************************************
   Function: TIMERHandler
   Description:
     Invoked 19.5 times per second.
****************************************
And in DjGpp Timer.h I also found
#define CLOCKS_PER_SEC 91
In BC31 timer.h
#define CLOCKS_PER_SEC 18.2

So I'm a quit confused and I don't know how many times per sec timer runs.

Is it compiler dependece (clock function in djgpp vs. bc)?

That one problem, but here comes second:
On i386 the maximum allowed type of variable is ulong, isn't it?
But function clock returns long. So maximum number is 2147483647L. If I
transfer it to days (using 18.2 ticks per sec ) I get 1365 day = 3.7 year
(aproximately). But may program may run more then 3.7 year (in one run)
counter of this type may overflow.
Is any possibility how to englare this range?

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