lib/libsys/sys_hz.c

   1
   2 #include <stdio.h>
   3 #include <sys/time.h>
   4 #include <sys/types.h>
   5 #include <minix/u64.h>
   6 #include <minix/config.h>
   7 #include <minix/const.h>
   8
   9 #include "sysutil.h"
  10
  11 static u32_t Hz;
  12
  13 u32_t
  14 sys_hz(void)
  15 {
  16         if(Hz <= 0) {
  17                 int r;
  18                 /* Get HZ. */
  19                 if((r=sys_getinfo(GET_HZ, &Hz, sizeof(Hz), 0, 0)) != OK) {
  20                         Hz = DEFAULT_HZ;
  21                         printf("sys_hz: can not get HZ: error %d.\nUsing default HZ = %u\n",
  22                             r, (unsigned int) Hz);
  23                 }
  24         }
  25
  26         return Hz;
  27 }
  28
  29 u32_t
  30 micros_to_ticks(u32_t micros)
  31 {
  32         u32_t ticks;
  33
  34         ticks = div64u(mul64u(micros, sys_hz()), 1000000);
  35         if(ticks < 1) ticks = 1;
  36
  37         return ticks;
  38 }
  39