dockapps/wmcpuload/src/cpu_freebsd.c
2012-02-12 22:50:31 +00:00

85 lines
1.6 KiB
C

/*
* cpu_freebsd.c - module to get cpu usage, for FreeBSD
*
* Copyright (c) 2001, 2002 Seiichi SATO <ssato@sh.rim.or.jp>
*
* Licensed under the GPL
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include "cpu.h"
#include <kvm.h>
#include <fcntl.h>
#include <sys/dkstat.h>
static kvm_t *kd = NULL;
static struct nlist nlst[] = { {"_cp_time"}, {0} };
void
cpu_init(void)
{
kd = kvm_open(NULL, NULL, NULL, O_RDONLY, "kvm_open");
if (kd == NULL) {
fprintf(stderr, "can't open kernel virtual memory");
exit(1);
}
kvm_nlist(kd, nlst);
if (nlst[0].n_type == 0) {
fprintf(stderr, "error extracting symbols");
exit(1);
}
/* drop setgid & setuid (the latter should not be there really) */
seteuid(getuid());
setegid(getgid());
if (geteuid() != getuid() || getegid() != getgid()) {
fprintf(stderr, "unable to drop privileges");
exit(1);
}
}
/* returns current CPU usage in percent */
int
cpu_get_usage(cpu_options *opts)
{
static int pre_used, pre_total;
int used, total, result;
unsigned long int cpu_time[CPUSTATES];
if (kvm_read(kd, nlst[0].n_value, &cpu_time, sizeof(cpu_time)) !=
sizeof(cpu_time))
return 0;
used = cpu_time[CP_USER] + cpu_time[CP_SYS];
if (!opts->ignore_nice)
used += cpu_time[CP_NICE];
total = used + cpu_time[CP_IDLE];
if (pre_total == 0) {
result = 0;
} else if ((total - pre_total) > 0) {
result = (100 * (double) (used - pre_used)) / (double) (total -
pre_total);
} else {
result = 0;
}
pre_used = used;
pre_total = total;
return result;
}