1 /* $OpenBSD: getloadavg.c,v 1.9 2020/10/12 22:08:33 deraadt Exp $ */ 2 /*- 3 * Copyright (c) 1989, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/time.h> 32 #include <sys/resource.h> 33 #include <sys/sysctl.h> 34 35 #include <stdlib.h> 36 37 #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b)) 38 39 /* 40 * getloadavg() -- Get system load averages. 41 * 42 * Put `nelem' samples into `loadavg' array. 43 * Return number of samples retrieved, or -1 on error. 44 */ 45 int 46 getloadavg(double loadavg[], int nelem) 47 { 48 struct loadavg loadinfo; 49 const int mib[2] = { CTL_VM, VM_LOADAVG }; 50 int i; 51 size_t size; 52 53 size = sizeof(loadinfo); 54 if (sysctl(mib, 2, &loadinfo, &size, NULL, 0) == -1) 55 return (-1); 56 57 nelem = MINIMUM(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t)); 58 for (i = 0; i < nelem; i++) 59 loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale; 60 return (nelem); 61 } 62