complete and factorize clocks API
Signed-off-by: Rémi Lefèvre <remi.lefevre@parrot.com>
Rémi Lefèvre committed
Dec 13, 2016 at 18:43 UTC
aef5572053fa8c55a0ded6ed08e4250bfc8b7986
2 files changed
+59
-47
src/clocks.c
+32
-24
@@ -11,55 +11,63 @@ inline int clock_gettime(clockid_t clk_id, struct timespec *ts) {
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}
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#endif
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-inline time_t now_realtime_sec(void) {
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+static inline time_t now_sec(clockid_t clk_id) {
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struct timespec ts;
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- if(unlikely(clock_gettime(CLOCK_REALTIME, &ts) == -1))
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+ if(unlikely(clock_gettime(clk_id, &ts) == -1))
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return 0;
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return ts.tv_sec;
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}
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-inline int now_realtime_timeval(struct timeval *tv) {
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+static inline usec_t now_usec(clockid_t clk_id) {
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+ struct timespec ts;
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+ if(unlikely(clock_gettime(clk_id, &ts) == -1))
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+ return 0;
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+ return (usec_t)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC;
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+}
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+
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+static inline int now_timeval(clockid_t clk_id, struct timeval *tv) {
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struct timespec ts;
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- if(unlikely(clock_gettime(CLOCK_REALTIME, &ts) == -1))
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+ if(unlikely(clock_gettime(clk_id, &ts) == -1))
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return -1;
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tv->tv_sec = ts.tv_sec;
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tv->tv_usec = ts.tv_nsec / NSEC_PER_USEC;
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return 0;
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}
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+inline time_t now_realtime_sec(void) {
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+ return now_sec(CLOCK_REALTIME);
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+}
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+
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inline usec_t now_realtime_usec(void) {
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- struct timespec ts;
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- if(unlikely(clock_gettime(CLOCK_REALTIME, &ts) == -1))
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- return 0;
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- return (usec_t)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC;
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+ return now_usec(CLOCK_REALTIME);
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+}
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+
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+inline int now_realtime_timeval(struct timeval *tv) {
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+ return now_timeval(CLOCK_REALTIME, tv);
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}
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inline time_t now_monotonic_sec(void) {
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- struct timespec ts;
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- if(unlikely(clock_gettime(CLOCK_MONOTONIC, &ts) == -1))
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- return 0;
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- return ts.tv_sec;
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+ return now_sec(CLOCK_MONOTONIC);
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}
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inline usec_t now_monotonic_usec(void) {
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- struct timespec ts;
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- if(unlikely(clock_gettime(CLOCK_MONOTONIC, &ts) == -1))
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- return 0;
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- return (usec_t)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC;
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+ return now_usec(CLOCK_MONOTONIC);
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+}
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+
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+inline int now_monotonic_timeval(struct timeval *tv) {
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+ return now_timeval(CLOCK_MONOTONIC, tv);
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}
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inline time_t now_boottime_sec(void) {
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- struct timespec ts;
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- if(unlikely(clock_gettime(CLOCK_BOOTTIME, &ts) == -1))
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- return 0;
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- return ts.tv_sec;
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+ return now_sec(CLOCK_BOOTTIME);
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}
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inline usec_t now_boottime_usec(void) {
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- struct timespec ts;
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- if(unlikely(clock_gettime(CLOCK_BOOTTIME, &ts) == -1))
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- return 0;
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- return (usec_t)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC;
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+ return now_usec(CLOCK_BOOTTIME);
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+}
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+
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+inline int now_boottime_timeval(struct timeval *tv) {
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+ return now_timeval(CLOCK_BOOTTIME, tv);
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}
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inline usec_t timeval_usec(struct timeval *tv) {
src/clocks.h
+27
-23
@@ -54,40 +54,44 @@ int clock_gettime(clockid_t clk_id, struct timespec *ts);
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extern int clock_gettime(clockid_t clk_id, struct timespec *ts);
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#endif
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-/* Fills struct timeval with time since EPOCH from real-time clock (i.e. wall-clock).
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- * - Hibernation/suspend time is included
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- * - adjtime()/NTP adjustments affect this clock
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- * Return 0 on succes, -1 else with errno set appropriately.
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+/*
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+ * Three clocks are available (cf. man 3 clock_gettime):
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+ *
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+ * REALTIME clock (i.e. wall-clock):
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+ * This clock is affected by discontinuous jumps in the system time
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+ * (e.g., if the system administrator manually changes the clock), and by the incremental adjustments performed by adjtime(3) and NTP.
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+ *
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+ * MONOTONIC clock
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+ * Clock that cannot be set and represents monotonic time since some unspecified starting point.
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+ * This clock is not affected by discontinuous jumps in the system time
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+ * (e.g., if the system administrator manually changes the clock), but is affected by the incremental adjustments performed by adjtime(3) and NTP.
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+ * If not available on the system, this clock falls back to REALTIME clock.
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+ *
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+ * BOOTTIME clock
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+ * Identical to CLOCK_MONOTONIC, except it also includes any time that the system is suspended.
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+ * This allows applications to get a suspend-aware monotonic clock without having to deal with the complications of CLOCK_REALTIME,
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+ * which may have discontinuities if the time is changed using settimeofday(2).
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+ * If not available on the system, this clock falls back to MONOTONIC clock.
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+ *
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+ * All now_*_timeval() functions fill the `struct timeval` with the time from the appropriate clock.
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+ * Those functions return 0 on success, -1 else with errno set appropriately.
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+ *
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+ * All now_*_sec() functions return the time in seconds from the approriate clock, or 0 on error.
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+ * All now_*_usec() functions return the time in microseconds from the approriate clock, or 0 on error.
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*/
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extern int now_realtime_timeval(struct timeval *tv);
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-
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-/* Returns time since EPOCH from real-time clock (i.e. wall-clock).
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- * - Hibernation/suspend time is included
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- * - adjtime()/NTP adjustments affect this clock
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- */
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extern time_t now_realtime_sec(void);
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extern usec_t now_realtime_usec(void);
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-/* Returns time from monotonic clock if available, real-time clock else.
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- * If monotonic clock is available:
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- * - hibernation/suspend time is not included
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- * - adjtime()/NTP adjusments affect this clock
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- * If monotonic clock is not available, this fallbacks to now_realtime().
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- */
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+extern int now_monotonic_timeval(struct timeval *tv);
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extern time_t now_monotonic_sec(void);
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extern usec_t now_monotonic_usec(void);
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-/* Returns time from boottime clock if available,
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- * monotonic clock else if available, real-time clock else.
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- * If boottime clock is available:
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- * - hibernation/suspend time is included
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- * - adjtime()/NTP adjusments affect this clock
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- * If boottime clock is not available, this fallbacks to now_monotonic().
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- * If monotonic clock is not available, this fallbacks to now_realtime().
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- */
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+extern int now_boottime_timeval(struct timeval *tv);
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extern time_t now_boottime_sec(void);
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extern usec_t now_boottime_usec(void);
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+
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extern usec_t timeval_usec(struct timeval *ts);
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extern usec_t dt_usec(struct timeval *now, struct timeval *old);
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