uclibc-ng/libc/misc/getloadavg/getloadavg.c

/*
 * Copyright © 2005-2020 Rich Felker, et al.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * Imported from musl C library
 */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif /* _GNU_SOURCE */
#include <stdlib.h>
#include <sys/sysinfo.h>

int getloadavg(double *a, int n)
{
	struct sysinfo si;
	if (n <= 0) return n ? -1 : 0;
	sysinfo(&si);
	if (n > 3) n = 3;
	for (int i=0; i<n; i++)
		a[i] = 1.0/(1<<SI_LOAD_SHIFT) * si.loads[i];
	return n;
}