diff options
Diffstat (limited to 'src/clocks.h')
| -rw-r--r-- | src/clocks.h | 94 |
1 files changed, 62 insertions, 32 deletions
diff --git a/src/clocks.h b/src/clocks.h index c1b8e701..197b5431 100644 --- a/src/clocks.h +++ b/src/clocks.h @@ -12,9 +12,12 @@ struct timespec { typedef int clockid_t; #endif -#ifndef HAVE_CLOCK_GETTIME -int clock_gettime(clockid_t clk_id, struct timespec *ts); -#endif +typedef unsigned long long nsec_t; +typedef unsigned long long msec_t; +typedef unsigned long long usec_t; +typedef long long susec_t; + +typedef usec_t heartbeat_t; /* Linux value is as good as any other */ #ifndef CLOCK_REALTIME @@ -27,20 +30,30 @@ int clock_gettime(clockid_t clk_id, struct timespec *ts); #endif #ifndef CLOCK_BOOTTIME -/* fallback to CLOCK_MONOTONIC if not available */ + +#ifdef CLOCK_UPTIME +/* CLOCK_BOOTTIME falls back to CLOCK_UPTIME on FreeBSD */ +#define CLOCK_BOOTTIME CLOCK_UPTIME +#else // CLOCK_UPTIME +/* CLOCK_BOOTTIME falls back to CLOCK_MONOTONIC */ #define CLOCK_BOOTTIME CLOCK_MONOTONIC -#else +#endif // CLOCK_UPTIME + +#else // CLOCK_BOOTTIME + #ifdef HAVE_CLOCK_GETTIME #define CLOCK_BOOTTIME_IS_AVAILABLE 1 // required for /proc/uptime -#endif -#endif +#endif // HAVE_CLOCK_GETTIME -typedef unsigned long long usec_t; +#endif // CLOCK_BOOTTIME -#define NSEC_PER_SEC 1000000000ULL #define NSEC_PER_MSEC 1000000ULL + +#define NSEC_PER_SEC 1000000000ULL #define NSEC_PER_USEC 1000ULL + #define USEC_PER_SEC 1000000ULL +#define MSEC_PER_SEC 1000ULL #ifndef HAVE_CLOCK_GETTIME /* Fallback function for POSIX.1-2001 clock_gettime() function. @@ -52,41 +65,58 @@ typedef unsigned long long usec_t; extern int clock_gettime(clockid_t clk_id, struct timespec *ts); #endif -/* Fills struct timeval with time since EPOCH from real-time clock (i.e. wall-clock). - * - Hibernation/suspend time is included - * - adjtime()/NTP adjustments affect this clock - * Return 0 on succes, -1 else with errno set appropriately. +/* + * Three clocks are available (cf. man 3 clock_gettime): + * + * REALTIME clock (i.e. wall-clock): + * This clock is affected by discontinuous jumps in the system time + * (e.g., if the system administrator manually changes the clock), and by the incremental adjustments performed by adjtime(3) and NTP. + * + * MONOTONIC clock + * Clock that cannot be set and represents monotonic time since some unspecified starting point. + * This clock is not affected by discontinuous jumps in the system time + * (e.g., if the system administrator manually changes the clock), but is affected by the incremental adjustments performed by adjtime(3) and NTP. + * If not available on the system, this clock falls back to REALTIME clock. + * + * BOOTTIME clock + * Identical to CLOCK_MONOTONIC, except it also includes any time that the system is suspended. + * This allows applications to get a suspend-aware monotonic clock without having to deal with the complications of CLOCK_REALTIME, + * which may have discontinuities if the time is changed using settimeofday(2). + * If not available on the system, this clock falls back to MONOTONIC clock. + * + * All now_*_timeval() functions fill the `struct timeval` with the time from the appropriate clock. + * Those functions return 0 on success, -1 else with errno set appropriately. + * + * All now_*_sec() functions return the time in seconds from the approriate clock, or 0 on error. + * All now_*_usec() functions return the time in microseconds from the approriate clock, or 0 on error. */ extern int now_realtime_timeval(struct timeval *tv); - -/* Returns time since EPOCH from real-time clock (i.e. wall-clock). - * - Hibernation/suspend time is included - * - adjtime()/NTP adjustments affect this clock - */ extern time_t now_realtime_sec(void); extern usec_t now_realtime_usec(void); -/* Returns time from monotonic clock if available, real-time clock else. - * If monotonic clock is available: - * - hibernation/suspend time is not included - * - adjtime()/NTP adjusments affect this clock - * If monotonic clock is not available, this fallbacks to now_realtime(). - */ +extern int now_monotonic_timeval(struct timeval *tv); extern time_t now_monotonic_sec(void); extern usec_t now_monotonic_usec(void); -/* Returns time from boottime clock if available, - * monotonic clock else if available, real-time clock else. - * If boottime clock is available: - * - hibernation/suspend time is included - * - adjtime()/NTP adjusments affect this clock - * If boottime clock is not available, this fallbacks to now_monotonic(). - * If monotonic clock is not available, this fallbacks to now_realtime(). - */ +extern int now_boottime_timeval(struct timeval *tv); extern time_t now_boottime_sec(void); extern usec_t now_boottime_usec(void); + extern usec_t timeval_usec(struct timeval *ts); +extern msec_t timeval_msec(struct timeval *tv); + extern usec_t dt_usec(struct timeval *now, struct timeval *old); +extern susec_t dt_usec_signed(struct timeval *now, struct timeval *old); + +extern void heartbeat_init(heartbeat_t *hb); + +/* Sleeps until next multiple of tick using monotonic clock. + * Returns elapsed time in microseconds since previous heartbeat + */ +extern usec_t heartbeat_next(heartbeat_t *hb, usec_t tick); + +/* Returns elapsed time in microseconds since last heartbeat */ +extern usec_t heartbeat_dt_usec(heartbeat_t *hb); #endif /* NETDATA_CLOCKS_H */ |