Wait 11 minutes before deciding a machine is down (same as ruptime).

[unix-history] / usr / src / usr.bin / gprof / hertz.c

#ifndef lint
   static      char *sccsid = "@(#)hertz.c     1.4 (Berkeley) %G%";
#endif lint

#include <sys/time.h>

   /*
    *  discover the tick frequency of the machine
    *  if something goes wrong, we return 0, an impossible hertz.
    */
#define HZ_WRONG        0

hertz()
{
       struct itimerval tim;

       tim.it_interval.tv_sec = 0;
       tim.it_interval.tv_usec = 1;
       tim.it_value.tv_sec = 0;
       tim.it_value.tv_usec = 0;
       setitimer(ITIMER_REAL, &tim, 0);
       setitimer(ITIMER_REAL, 0, &tim);
       if (tim.it_interval.tv_usec < 2)
               return(HZ_WRONG);
       return (1000000 / tim.it_interval.tv_usec);
}