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-rw-r--r--libnetdata/clocks/clocks.c300
1 files changed, 300 insertions, 0 deletions
diff --git a/libnetdata/clocks/clocks.c b/libnetdata/clocks/clocks.c
new file mode 100644
index 0000000..4ec5fa9
--- /dev/null
+++ b/libnetdata/clocks/clocks.c
@@ -0,0 +1,300 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "../libnetdata.h"
+
+static int clock_boottime_valid = 1;
+static int clock_monotonic_coarse_valid = 1;
+
+#ifndef HAVE_CLOCK_GETTIME
+inline int clock_gettime(clockid_t clk_id, struct timespec *ts) {
+ struct timeval tv;
+ if(unlikely(gettimeofday(&tv, NULL) == -1)) {
+ error("gettimeofday() failed.");
+ return -1;
+ }
+ ts->tv_sec = tv.tv_sec;
+ ts->tv_nsec = (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC;
+ return 0;
+}
+#endif
+
+void test_clock_boottime(void) {
+ struct timespec ts;
+ if(clock_gettime(CLOCK_BOOTTIME, &ts) == -1 && errno == EINVAL)
+ clock_boottime_valid = 0;
+}
+
+void test_clock_monotonic_coarse(void) {
+ struct timespec ts;
+ if(clock_gettime(CLOCK_MONOTONIC_COARSE, &ts) == -1 && errno == EINVAL)
+ clock_monotonic_coarse_valid = 0;
+}
+
+static inline time_t now_sec(clockid_t clk_id) {
+ struct timespec ts;
+ if(unlikely(clock_gettime(clk_id, &ts) == -1)) {
+ error("clock_gettime(%d, &timespec) failed.", clk_id);
+ return 0;
+ }
+ return ts.tv_sec;
+}
+
+static inline usec_t now_usec(clockid_t clk_id) {
+ struct timespec ts;
+ if(unlikely(clock_gettime(clk_id, &ts) == -1)) {
+ error("clock_gettime(%d, &timespec) failed.", clk_id);
+ return 0;
+ }
+ return (usec_t)ts.tv_sec * USEC_PER_SEC + (ts.tv_nsec % NSEC_PER_SEC) / NSEC_PER_USEC;
+}
+
+static inline int now_timeval(clockid_t clk_id, struct timeval *tv) {
+ struct timespec ts;
+
+ if(unlikely(clock_gettime(clk_id, &ts) == -1)) {
+ error("clock_gettime(%d, &timespec) failed.", clk_id);
+ tv->tv_sec = 0;
+ tv->tv_usec = 0;
+ return -1;
+ }
+
+ tv->tv_sec = ts.tv_sec;
+ tv->tv_usec = (suseconds_t)((ts.tv_nsec % NSEC_PER_SEC) / NSEC_PER_USEC);
+ return 0;
+}
+
+inline time_t now_realtime_sec(void) {
+ return now_sec(CLOCK_REALTIME);
+}
+
+inline usec_t now_realtime_usec(void) {
+ return now_usec(CLOCK_REALTIME);
+}
+
+inline int now_realtime_timeval(struct timeval *tv) {
+ return now_timeval(CLOCK_REALTIME, tv);
+}
+
+inline time_t now_monotonic_sec(void) {
+ return now_sec(likely(clock_monotonic_coarse_valid) ? CLOCK_MONOTONIC_COARSE : CLOCK_MONOTONIC);
+}
+
+inline usec_t now_monotonic_usec(void) {
+ return now_usec(likely(clock_monotonic_coarse_valid) ? CLOCK_MONOTONIC_COARSE : CLOCK_MONOTONIC);
+}
+
+inline int now_monotonic_timeval(struct timeval *tv) {
+ return now_timeval(likely(clock_monotonic_coarse_valid) ? CLOCK_MONOTONIC_COARSE : CLOCK_MONOTONIC, tv);
+}
+
+inline time_t now_monotonic_high_precision_sec(void) {
+ return now_sec(CLOCK_MONOTONIC);
+}
+
+inline usec_t now_monotonic_high_precision_usec(void) {
+ return now_usec(CLOCK_MONOTONIC);
+}
+
+inline int now_monotonic_high_precision_timeval(struct timeval *tv) {
+ return now_timeval(CLOCK_MONOTONIC, tv);
+}
+
+inline time_t now_boottime_sec(void) {
+ return now_sec(likely(clock_boottime_valid) ? CLOCK_BOOTTIME :
+ likely(clock_monotonic_coarse_valid) ? CLOCK_MONOTONIC_COARSE : CLOCK_MONOTONIC);
+}
+
+inline usec_t now_boottime_usec(void) {
+ return now_usec(likely(clock_boottime_valid) ? CLOCK_BOOTTIME :
+ likely(clock_monotonic_coarse_valid) ? CLOCK_MONOTONIC_COARSE : CLOCK_MONOTONIC);
+}
+
+inline int now_boottime_timeval(struct timeval *tv) {
+ return now_timeval(likely(clock_boottime_valid) ? CLOCK_BOOTTIME :
+ likely(clock_monotonic_coarse_valid) ? CLOCK_MONOTONIC_COARSE : CLOCK_MONOTONIC,
+ tv);
+}
+
+inline usec_t timeval_usec(struct timeval *tv) {
+ return (usec_t)tv->tv_sec * USEC_PER_SEC + (tv->tv_usec % USEC_PER_SEC);
+}
+
+inline msec_t timeval_msec(struct timeval *tv) {
+ return (msec_t)tv->tv_sec * MSEC_PER_SEC + ((tv->tv_usec % USEC_PER_SEC) / MSEC_PER_SEC);
+}
+
+inline susec_t dt_usec_signed(struct timeval *now, struct timeval *old) {
+ usec_t ts1 = timeval_usec(now);
+ usec_t ts2 = timeval_usec(old);
+
+ if(likely(ts1 >= ts2)) return (susec_t)(ts1 - ts2);
+ return -((susec_t)(ts2 - ts1));
+}
+
+inline usec_t dt_usec(struct timeval *now, struct timeval *old) {
+ usec_t ts1 = timeval_usec(now);
+ usec_t ts2 = timeval_usec(old);
+ return (ts1 > ts2) ? (ts1 - ts2) : (ts2 - ts1);
+}
+
+inline void heartbeat_init(heartbeat_t *hb)
+{
+ hb->monotonic = hb->realtime = 0ULL;
+}
+
+// waits for the next heartbeat
+// it waits using the monotonic clock
+// it returns the dt using the realtime clock
+
+usec_t heartbeat_next(heartbeat_t *hb, usec_t tick) {
+ heartbeat_t now;
+ now.monotonic = now_monotonic_usec();
+ now.realtime = now_realtime_usec();
+
+ usec_t next_monotonic = now.monotonic - (now.monotonic % tick) + tick;
+
+ while(now.monotonic < next_monotonic) {
+ sleep_usec(next_monotonic - now.monotonic);
+ now.monotonic = now_monotonic_usec();
+ now.realtime = now_realtime_usec();
+ }
+
+ if(likely(hb->realtime != 0ULL)) {
+ usec_t dt_monotonic = now.monotonic - hb->monotonic;
+ usec_t dt_realtime = now.realtime - hb->realtime;
+
+ hb->monotonic = now.monotonic;
+ hb->realtime = now.realtime;
+
+ if(unlikely(dt_monotonic >= tick + tick / 2)) {
+ errno = 0;
+ error("heartbeat missed %llu monotonic microseconds", dt_monotonic - tick);
+ }
+
+ return dt_realtime;
+ }
+ else {
+ hb->monotonic = now.monotonic;
+ hb->realtime = now.realtime;
+ return 0ULL;
+ }
+}
+
+// returned the elapsed time, since the last heartbeat
+// using the monotonic clock
+
+inline usec_t heartbeat_monotonic_dt_to_now_usec(heartbeat_t *hb) {
+ if(!hb || !hb->monotonic) return 0ULL;
+ return now_monotonic_usec() - hb->monotonic;
+}
+
+int sleep_usec(usec_t usec) {
+
+#ifndef NETDATA_WITH_USLEEP
+ // we expect microseconds (1.000.000 per second)
+ // but timespec is nanoseconds (1.000.000.000 per second)
+ struct timespec rem, req = {
+ .tv_sec = (time_t) (usec / 1000000),
+ .tv_nsec = (suseconds_t) ((usec % 1000000) * 1000)
+ };
+
+ while (nanosleep(&req, &rem) == -1) {
+ if (likely(errno == EINTR)) {
+ debug(D_SYSTEM, "nanosleep() interrupted (while sleeping for %llu microseconds).", usec);
+ req.tv_sec = rem.tv_sec;
+ req.tv_nsec = rem.tv_nsec;
+ } else {
+ error("Cannot nanosleep() for %llu microseconds.", usec);
+ break;
+ }
+ }
+
+ return 0;
+#else
+ int ret = usleep(usec);
+ if(unlikely(ret == -1 && errno == EINVAL)) {
+ // on certain systems, usec has to be up to 999999
+ if(usec > 999999) {
+ int counter = usec / 999999;
+ while(counter--)
+ usleep(999999);
+
+ usleep(usec % 999999);
+ }
+ else {
+ error("Cannot usleep() for %llu microseconds.", usec);
+ return ret;
+ }
+ }
+
+ if(ret != 0)
+ error("usleep() failed for %llu microseconds.", usec);
+
+ return ret;
+#endif
+}
+
+static inline collected_number uptime_from_boottime(void) {
+#ifdef CLOCK_BOOTTIME_IS_AVAILABLE
+ return now_boottime_usec() / 1000;
+#else
+ error("uptime cannot be read from CLOCK_BOOTTIME on this system.");
+ return 0;
+#endif
+}
+
+static procfile *read_proc_uptime_ff = NULL;
+static inline collected_number read_proc_uptime(char *filename) {
+ if(unlikely(!read_proc_uptime_ff)) {
+ read_proc_uptime_ff = procfile_open(filename, " \t", PROCFILE_FLAG_DEFAULT);
+ if(unlikely(!read_proc_uptime_ff)) return 0;
+ }
+
+ read_proc_uptime_ff = procfile_readall(read_proc_uptime_ff);
+ if(unlikely(!read_proc_uptime_ff)) return 0;
+
+ if(unlikely(procfile_lines(read_proc_uptime_ff) < 1)) {
+ error("/proc/uptime has no lines.");
+ return 0;
+ }
+ if(unlikely(procfile_linewords(read_proc_uptime_ff, 0) < 1)) {
+ error("/proc/uptime has less than 1 word in it.");
+ return 0;
+ }
+
+ return (collected_number)(strtold(procfile_lineword(read_proc_uptime_ff, 0, 0), NULL) * 1000.0);
+}
+
+inline collected_number uptime_msec(char *filename){
+ static int use_boottime = -1;
+
+ if(unlikely(use_boottime == -1)) {
+ collected_number uptime_boottime = uptime_from_boottime();
+ collected_number uptime_proc = read_proc_uptime(filename);
+
+ long long delta = (long long)uptime_boottime - (long long)uptime_proc;
+ if(delta < 0) delta = -delta;
+
+ if(delta <= 1000 && uptime_boottime != 0) {
+ procfile_close(read_proc_uptime_ff);
+ info("Using now_boottime_usec() for uptime (dt is %lld ms)", delta);
+ use_boottime = 1;
+ }
+ else if(uptime_proc != 0) {
+ info("Using /proc/uptime for uptime (dt is %lld ms)", delta);
+ use_boottime = 0;
+ }
+ else {
+ error("Cannot find any way to read uptime on this system.");
+ return 1;
+ }
+ }
+
+ collected_number uptime;
+ if(use_boottime)
+ uptime = uptime_from_boottime();
+ else
+ uptime = read_proc_uptime(filename);
+
+ return uptime;
+}
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