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Date: Sun, 20 Jun 1999 15:52:29 +0200 (CEST)
From: marcelk@bitpit.net
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To: FreeBSD-gnats-submit@freebsd.org
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Subject: kern/12305: clock() ticks backwards
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>Number:         12305
>Category:       kern
>Synopsis:       clock() ticks backwards
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Jun 20 07:00:02 PDT 1999
>Closed-Date:
>Last-Modified:
>Originator:     Marcel van Kervinck
>Release:        FreeBSD 3.2-BETA i386
>Organization:
>Environment:

Observed in releases 2.2, 3.1 and 3.2, SMP and non-SMP kernels.

>Description:

Consecutive calls to clock() sometimes suggest negative elapsed time.

>How-To-Repeat:

#include <time.h>
#include <stdio.h>

int main (void)
{
	clock_t a, b;

	for (;;) {
		b = clock ();
		do {
			a = b;
			b = clock ();
		} while (a <= b);

		printf ("%lu %lu\n", (unsigned long)a, (unsigned long)b);
	}
	return 0;
}


>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted:


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