xref: /openbsd/usr.bin/gprof/hertz.c (revision f6aab3d8)
1 /*	$OpenBSD: hertz.c,v 1.7 2015/01/16 06:40:08 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 2005 Artur Grabowski <art@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 
20 #include <sys/time.h>
21 #include <sys/sysctl.h>
22 
23 #include "gprof.h"
24 
25 /*
26  * Return the tick frequency on the machine or 0 if we can't find out.
27  */
28 
29 int
30 hertz(void)
31 {
32 	struct clockinfo cinfo;
33 	int mib[2];
34 	size_t len;
35 
36 	mib[0] = CTL_KERN;
37 	mib[1] = KERN_CLOCKRATE;
38 	len = sizeof(cinfo);
39 	if (sysctl(mib, 2, &cinfo, &len, NULL, 0) == -1)
40 		return (0);
41 
42 	return (cinfo.hz);
43 }
44