lib/monotonic.c

   1 /*
   2  * Please, don't add this file to libcommon because clock_gettime() requires
   3  * -lrt on systems with old libc.
   4  */
   5 #include <time.h>
   6 #include <signal.h>
   7 #ifdef HAVE_SYSINFO
   8 #include <sys/sysinfo.h>
   9 #endif
  10 #include <sys/time.h>
  11
  12 #include "c.h"
  13 #include "monotonic.h"
  14
  15 int get_boot_time(struct timeval *boot_time)
  16 {
  17 #ifdef CLOCK_BOOTTIME
  18         struct timespec hires_uptime;
  19         struct timeval lores_uptime;
  20 #endif
  21         struct timeval now;
  22 #ifdef HAVE_SYSINFO
  23         struct sysinfo info;
  24 #endif
  25
  26         if (gettimeofday(&now, NULL) != 0)
  27                 return -errno;
  28 #ifdef CLOCK_BOOTTIME
  29         if (clock_gettime(CLOCK_BOOTTIME, &hires_uptime) == 0) {
  30                 TIMESPEC_TO_TIMEVAL(&lores_uptime, &hires_uptime);
  31                 timersub(&now, &lores_uptime, boot_time);
  32                 return 0;
  33         }
  34 #endif
  35 #ifdef HAVE_SYSINFO
  36         /* fallback */
  37         if (sysinfo(&info) != 0)
  38                 return -errno;
  39
  40         boot_time->tv_sec = now.tv_sec - info.uptime;
  41         boot_time->tv_usec = 0;
  42         return 0;
  43 #else
  44         return -ENOSYS;
  45 #endif
  46 }
  47
  48 int gettime_monotonic(struct timeval *tv)
  49 {
  50 #ifdef CLOCK_MONOTONIC
  51         /* Can slew only by ntp and adjtime */
  52         int ret;
  53         struct timespec ts;
  54
  55 # ifdef CLOCK_MONOTONIC_RAW
  56         /* Linux specific, can't slew */
  57         if (!(ret = clock_gettime(CLOCK_MONOTONIC_RAW, &ts))) {
  58 # else
  59         if (!(ret = clock_gettime(CLOCK_MONOTONIC, &ts))) {
  60 # endif
  61                 tv->tv_sec = ts.tv_sec;
  62                 tv->tv_usec = ts.tv_nsec / 1000;
  63         }
  64         return ret;
  65 #else
  66         return gettimeofday(tv, NULL);
  67 #endif
  68 }
  69
  70