wmcpuload/src/cpu_openbsd.c

   1 /*
   2  * cpu_openbsd - module to get cpu usage, for OpenBSD
   3  *
   4  * Copyright (C) 2001, 2002 Seiichi SATO <ssato@sh.rim.or.jp>
   5  * Copyright (C) 2003 Nedko Arnaudov <nedko@users.sourceforge.net>
   6  *
   7  * Licensed under the GPL
   8  */
   9
  10 #ifdef HAVE_CONFIG_H
  11 #include "config.h"
  12 #endif
  13
  14 #include <stdio.h>
  15 #include <unistd.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include "cpu.h"
  19
  20 #include <sys/param.h>
  21 #include <sys/sysctl.h>
  22 #include <sys/dkstat.h>
  23
  24 void
  25 cpu_init(void)
  26 {
  27     /* You don't need initialization under OpenBSD */
  28     return;
  29 }
  30
  31 /* Returns the current CPU usage in percent */
  32 int
  33 cpu_get_usage(cpu_options *opts)
  34 {
  35     int total, used, result;
  36     static int pre_total, pre_used;
  37
  38     int mib[] = { CTL_KERN, KERN_CPTIME };
  39     unsigned long int cpu_time[CPUSTATES];
  40     size_t size = sizeof(cpu_time);
  41
  42     /* get cpu time*/
  43     if (sysctl(mib, 2, &cpu_time, &size, NULL, 0) < 0)
  44         return 0;
  45
  46     /* calc usage */
  47     total = cpu_time[CP_USER] + cpu_time[CP_SYS] + cpu_time[CP_INTR] +
  48             cpu_time[CP_NICE] + cpu_time[CP_IDLE];
  49     used = cpu_time[CP_USER] + cpu_time[CP_SYS] + cpu_time[CP_INTR] +
  50            (opts->ignore_nice ? 0 : cpu_time[CP_NICE]);
  51     if ((pre_total == 0) || !(total - pre_total > 0)) {
  52         result = 0;
  53     } else {
  54         result = 100 * (double)(used - pre_used) / (double)(total - pre_total);
  55     }
  56
  57     /* save used/total for next calculation */
  58     pre_used = used;
  59     pre_total = total;
  60
  61     return result;
  62 }