NetBSD/lib/libc/gen/getloadavg.c

82 lines
2.8 KiB
C

/* $NetBSD: getloadavg.c,v 1.14 2012/03/13 21:13:36 christos 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/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)getloadavg.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: getloadavg.c,v 1.14 2012/03/13 21:13:36 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/param.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/sysctl.h>
#include <uvm/uvm_param.h>
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#ifdef __weak_alias
__weak_alias(getloadavg,_getloadavg)
#endif
/*
* 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;
static const int mib[] = { CTL_VM, VM_LOADAVG };
size_t size, i;
_DIAGASSERT(loadavg != NULL);
_DIAGASSERT(nelem >= 0);
size = sizeof(loadinfo);
if (sysctl(mib, (u_int)__arraycount(mib), &loadinfo, &size, NULL, 0)
== -1)
return -1;
size = MIN((size_t)nelem, __arraycount(loadinfo.ldavg));
for (i = 0; i < size; i++)
loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale;
return nelem;
}