xref: /freebsd/lib/libc/gen/clock.c (revision fbbd9655e5107c68e4e0146ff22b73d7350475bc)
158f0484fSRodney W. Grimes /*
258f0484fSRodney W. Grimes  * Copyright (c) 1989, 1993
358f0484fSRodney W. Grimes  *	The Regents of the University of California.  All rights reserved.
458f0484fSRodney W. Grimes  *
558f0484fSRodney W. Grimes  * Redistribution and use in source and binary forms, with or without
658f0484fSRodney W. Grimes  * modification, are permitted provided that the following conditions
758f0484fSRodney W. Grimes  * are met:
858f0484fSRodney W. Grimes  * 1. Redistributions of source code must retain the above copyright
958f0484fSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer.
1058f0484fSRodney W. Grimes  * 2. Redistributions in binary form must reproduce the above copyright
1158f0484fSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer in the
1258f0484fSRodney W. Grimes  *    documentation and/or other materials provided with the distribution.
13*fbbd9655SWarner Losh  * 3. Neither the name of the University nor the names of its contributors
1458f0484fSRodney W. Grimes  *    may be used to endorse or promote products derived from this software
1558f0484fSRodney W. Grimes  *    without specific prior written permission.
1658f0484fSRodney W. Grimes  *
1758f0484fSRodney W. Grimes  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
1858f0484fSRodney W. Grimes  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1958f0484fSRodney W. Grimes  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
2058f0484fSRodney W. Grimes  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
2158f0484fSRodney W. Grimes  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2258f0484fSRodney W. Grimes  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2358f0484fSRodney W. Grimes  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2458f0484fSRodney W. Grimes  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2558f0484fSRodney W. Grimes  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2658f0484fSRodney W. Grimes  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2758f0484fSRodney W. Grimes  * SUCH DAMAGE.
2858f0484fSRodney W. Grimes  */
2958f0484fSRodney W. Grimes 
3058f0484fSRodney W. Grimes #if defined(LIBC_SCCS) && !defined(lint)
3158f0484fSRodney W. Grimes static char sccsid[] = "@(#)clock.c	8.1 (Berkeley) 6/4/93";
3258f0484fSRodney W. Grimes #endif /* LIBC_SCCS and not lint */
33333fc21eSDavid E. O'Brien #include <sys/cdefs.h>
34333fc21eSDavid E. O'Brien __FBSDID("$FreeBSD$");
3558f0484fSRodney W. Grimes 
3658f0484fSRodney W. Grimes #include <sys/param.h>
3758f0484fSRodney W. Grimes #include <sys/time.h>
3858f0484fSRodney W. Grimes #include <sys/resource.h>
3958f0484fSRodney W. Grimes 
4058f0484fSRodney W. Grimes /*
413652b5c2SBruce Evans  * Convert usec to clock ticks; could do (usec * CLOCKS_PER_SEC) / 1000000,
4258f0484fSRodney W. Grimes  * but this would overflow if we switch to nanosec.
4358f0484fSRodney W. Grimes  */
443652b5c2SBruce Evans #define	CONVTCK(r)	((r).tv_sec * CLOCKS_PER_SEC \
453652b5c2SBruce Evans 			 + (r).tv_usec / (1000000 / CLOCKS_PER_SEC))
4658f0484fSRodney W. Grimes 
4758f0484fSRodney W. Grimes clock_t
48996f7159SCraig Rodrigues clock(void)
4958f0484fSRodney W. Grimes {
5058f0484fSRodney W. Grimes 	struct rusage ru;
5158f0484fSRodney W. Grimes 
5258f0484fSRodney W. Grimes 	if (getrusage(RUSAGE_SELF, &ru))
5358f0484fSRodney W. Grimes 		return ((clock_t) -1);
5458f0484fSRodney W. Grimes 	return((clock_t)((CONVTCK(ru.ru_utime) + CONVTCK(ru.ru_stime))));
5558f0484fSRodney W. Grimes }
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