xref: /titanic_41/usr/src/lib/libc/port/gen/clock.c (revision bdfc6d18da790deeec2e0eb09c625902defe2498)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 
33 #include "synonyms.h"
34 #include <sys/types.h>
35 #include <sys/times.h>
36 #include <time.h>
37 #include <sys/param.h>	/* for HZ (clock frequency in Hz) */
38 
39 #define	TIMES(B)	(B.tms_utime+B.tms_stime+B.tms_cutime+B.tms_cstime)
40 
41 
42 clock_t
43 clock(void)
44 {
45 	struct tms buffer;
46 	static int Hz = 0;
47 	static clock_t first;
48 	extern int gethz(void);		/* XXX should be in a header file! */
49 
50 	if (times(&buffer) == (clock_t)-1)
51 		return ((clock_t)-1);
52 	if (Hz == 0) {
53 		if ((Hz = gethz()) == 0)
54 			Hz = HZ;
55 		first = TIMES(buffer);
56 	}
57 
58 	return ((TIMES(buffer) - first) * (CLOCKS_PER_SEC/Hz));
59 }
60