summaryrefslogtreecommitdiff
path: root/lib/libc/gen/getloadavg.c
blob: 5eb7fa7de75baf552b9067b2fe7099cde128b028 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
/*	$OpenBSD: getloadavg.c,v 1.9 2020/10/12 22:08:33 deraadt Exp $ */
/*-
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/time.h>
#include <sys/resource.h>
#include <sys/sysctl.h>

#include <stdlib.h>

#define MINIMUM(a, b)	(((a) < (b)) ? (a) : (b))

/*
 * getloadavg() -- Get system load averages.
 *
 * Put `nelem' samples into `loadavg' array.
 * Return number of samples retrieved, or -1 on error.
 */
int
getloadavg(double loadavg[], int nelem)
{
	struct loadavg loadinfo;
	const int mib[2] = { CTL_VM, VM_LOADAVG };
	int i;
	size_t size;

	size = sizeof(loadinfo);
	if (sysctl(mib, 2, &loadinfo, &size, NULL, 0) == -1)
		return (-1);

	nelem = MINIMUM(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t));
	for (i = 0; i < nelem; i++)
		loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale;
	return (nelem);
}