util-linux/lib/monotonic.c

82 lines
1.6 KiB
C

/*
* Please, don't add this file to libcommon because clock_gettime() requires
* -lrt on systems with old libc.
*
* No copyright is claimed. This code is in the public domain; do with
* it what you wish.
*/
#include <time.h>
#include <signal.h>
#ifdef HAVE_SYSINFO
#include <sys/sysinfo.h>
#endif
#include <sys/time.h>
#include "c.h"
#include "monotonic.h"
int get_boot_time(struct timeval *boot_time)
{
#ifdef CLOCK_BOOTTIME
struct timespec hires_uptime;
struct timeval lores_uptime;
#endif
struct timeval now;
#ifdef HAVE_SYSINFO
struct sysinfo info;
#endif
if (gettimeofday(&now, NULL) != 0)
return -errno;
#ifdef CLOCK_BOOTTIME
if (clock_gettime(CLOCK_BOOTTIME, &hires_uptime) == 0) {
TIMESPEC_TO_TIMEVAL(&lores_uptime, &hires_uptime);
timersub(&now, &lores_uptime, boot_time);
return 0;
}
#endif
#ifdef HAVE_SYSINFO
/* fallback */
if (sysinfo(&info) != 0)
return -errno;
boot_time->tv_sec = now.tv_sec - info.uptime;
boot_time->tv_usec = 0;
return 0;
#else
return -ENOSYS;
#endif
}
time_t get_suspended_time(void)
{
#if defined(CLOCK_BOOTTIME) && defined(CLOCK_MONOTONIC)
struct timespec boot, mono;
if (clock_gettime(CLOCK_BOOTTIME, &boot) == 0 &&
clock_gettime(CLOCK_MONOTONIC, &mono) == 0)
return boot.tv_sec - mono.tv_sec;
#endif
return 0;
}
int gettime_monotonic(struct timeval *tv)
{
#ifdef CLOCK_MONOTONIC
/* Can slew only by ntp and adjtime */
int ret;
struct timespec ts;
/* Linux specific, can't slew */
if (!(ret = clock_gettime(UL_CLOCK_MONOTONIC, &ts))) {
tv->tv_sec = ts.tv_sec;
tv->tv_usec = ts.tv_nsec / 1000;
}
return ret;
#else
return gettimeofday(tv, NULL);
#endif
}