Merging upstream version 1.46.3.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 0 insertions, 658 deletions

diff --git a/libnetdata/clocks/Makefile.am b/libnetdata/clocks/Makefile.am
deleted file mode 100644
index 161784b8f..000000000
--- a/libnetdata/clocks/Makefile.am
+++ /dev/null
@@ -1,8 +0,0 @@
-# SPDX-License-Identifier: GPL-3.0-or-later
-
-AUTOMAKE_OPTIONS = subdir-objects
-MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
-
-dist_noinst_DATA = \
-    README.md \
-    $(NULL)
diff --git a/libnetdata/clocks/README.md b/libnetdata/clocks/README.md
deleted file mode 100644
index 33b0f0e85..000000000
--- a/libnetdata/clocks/README.md
+++ /dev/null
@@ -1,10 +0,0 @@
-<!--
-custom_edit_url: "https://github.com/netdata/netdata/edit/master/libnetdata/clocks/README.md"
-title: "Clocks"
-sidebar_label: "Clocks"
-learn_status: "Published"
-learn_topic_type: "References"
-learn_rel_path: "Developers/libnetdata"
--->
-
-# Clocks
\ No newline at end of file
diff --git a/libnetdata/clocks/clocks.c b/libnetdata/clocks/clocks.c
deleted file mode 100644
index adbad045f..000000000
--- a/libnetdata/clocks/clocks.c
+++ /dev/null
@@ -1,478 +0,0 @@
-// SPDX-License-Identifier: GPL-3.0-or-later
-
-#include "../libnetdata.h"
-
-// defaults are for compatibility
-// call clocks_init() once, to optimize these default settings
-static clockid_t clock_boottime_to_use = CLOCK_MONOTONIC;
-static clockid_t clock_monotonic_to_use = CLOCK_MONOTONIC;
-
-// the default clock resolution is 1ms
-#define DEFAULT_CLOCK_RESOLUTION_UT ((usec_t)0 * USEC_PER_SEC + (usec_t)1 * USEC_PER_MS)
-
-// the max clock resolution is 10ms
-#define MAX_CLOCK_RESOLUTION_UT ((usec_t)0 * USEC_PER_SEC + (usec_t)10 * USEC_PER_MS)
-
-usec_t clock_monotonic_resolution = DEFAULT_CLOCK_RESOLUTION_UT;
-usec_t clock_realtime_resolution = DEFAULT_CLOCK_RESOLUTION_UT;
-
-#ifndef HAVE_CLOCK_GETTIME
-inline int clock_gettime(clockid_t clk_id __maybe_unused, struct timespec *ts) {
-    struct timeval tv;
-    if(unlikely(gettimeofday(&tv, NULL) == -1)) {
-        netdata_log_error("gettimeofday() failed.");
-        return -1;
-    }
-    ts->tv_sec = tv.tv_sec;
-    ts->tv_nsec = (long)((tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC);
-    return 0;
-}
-#endif
-
-// Similar to CLOCK_MONOTONIC, but provides access to a raw hardware-based time that is not subject to NTP adjustments
-// or the incremental adjustments performed by adjtime(3).  This clock does not count time that the system is suspended
-
-static void test_clock_monotonic_raw(void) {
-#ifdef CLOCK_MONOTONIC_RAW
-    struct timespec ts;
-    if(clock_gettime(CLOCK_MONOTONIC_RAW, &ts) == -1 && errno == EINVAL)
-        clock_monotonic_to_use = CLOCK_MONOTONIC;
-    else
-        clock_monotonic_to_use = CLOCK_MONOTONIC_RAW;
-#else
-    clock_monotonic_to_use = CLOCK_MONOTONIC;
-#endif
-}
-
-// When running a binary with CLOCK_BOOTTIME defined on a system with a linux kernel older than Linux 2.6.39 the
-// clock_gettime(2) system call fails with EINVAL. In that case it must fall-back to CLOCK_MONOTONIC.
-
-static void test_clock_boottime(void) {
-    struct timespec ts;
-    if(clock_gettime(CLOCK_BOOTTIME, &ts) == -1 && errno == EINVAL)
-        clock_boottime_to_use = clock_monotonic_to_use;
-    else
-        clock_boottime_to_use = CLOCK_BOOTTIME;
-}
-
-static usec_t get_clock_resolution(clockid_t clock) {
-    struct timespec ts = { 0 };
-
-    if(clock_getres(clock, &ts) == 0) {
-        usec_t ret = (usec_t)ts.tv_sec * USEC_PER_SEC + (usec_t)ts.tv_nsec / NSEC_PER_USEC;
-        if(!ret && ts.tv_nsec > 0 && ts.tv_nsec < NSEC_PER_USEC)
-            return (usec_t)1;
-
-        else if(ret > MAX_CLOCK_RESOLUTION_UT) {
-            nd_log(NDLS_DAEMON, NDLP_ERR, "clock_getres(%d) returned %"PRIu64" usec is out of range, using defaults for clock resolution.", (int)clock, ret);
-            return DEFAULT_CLOCK_RESOLUTION_UT;
-        }
-
-        return ret;
-    }
-    else {
-        nd_log(NDLS_DAEMON, NDLP_ERR, "clock_getres(%d) failed, using defaults for clock resolution.", (int)clock);
-        return DEFAULT_CLOCK_RESOLUTION_UT;
-    }
-}
-
-// perform any initializations required for clocks
-
-void clocks_init(void) {
-    // monotonic raw has to be tested before boottime
-    test_clock_monotonic_raw();
-
-    // boottime has to be tested after monotonic coarse
-    test_clock_boottime();
-
-    clock_monotonic_resolution = get_clock_resolution(clock_monotonic_to_use);
-    clock_realtime_resolution = get_clock_resolution(CLOCK_REALTIME);
-}
-
-inline time_t now_sec(clockid_t clk_id) {
-    struct timespec ts;
-    if(unlikely(clock_gettime(clk_id, &ts) == -1)) {
-        netdata_log_error("clock_gettime(%d, &timespec) failed.", clk_id);
-        return 0;
-    }
-    return ts.tv_sec;
-}
-
-inline usec_t now_usec(clockid_t clk_id) {
-    struct timespec ts;
-    if(unlikely(clock_gettime(clk_id, &ts) == -1)) {
-        netdata_log_error("clock_gettime(%d, &timespec) failed.", clk_id);
-        return 0;
-    }
-    return (usec_t)ts.tv_sec * USEC_PER_SEC + (usec_t)(ts.tv_nsec % NSEC_PER_SEC) / NSEC_PER_USEC;
-}
-
-inline int now_timeval(clockid_t clk_id, struct timeval *tv) {
-    struct timespec ts;
-
-    if(unlikely(clock_gettime(clk_id, &ts) == -1)) {
-        netdata_log_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 msec_t now_realtime_msec(void) {
-    return now_usec(CLOCK_REALTIME) / USEC_PER_MS;
-}
-
-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(clock_monotonic_to_use);
-}
-
-inline usec_t now_monotonic_usec(void) {
-    return now_usec(clock_monotonic_to_use);
-}
-
-inline int now_monotonic_timeval(struct timeval *tv) {
-    return now_timeval(clock_monotonic_to_use, 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(clock_boottime_to_use);
-}
-
-inline usec_t now_boottime_usec(void) {
-    return now_usec(clock_boottime_to_use);
-}
-
-inline int now_boottime_timeval(struct timeval *tv) {
-    return now_timeval(clock_boottime_to_use, 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);
-}
-
-#ifdef __linux__
-void sleep_to_absolute_time(usec_t usec) {
-    static int einval_printed = 0, enotsup_printed = 0, eunknown_printed = 0;
-    clockid_t clock = CLOCK_REALTIME;
-
-    struct timespec req = {
-        .tv_sec = (time_t)(usec / USEC_PER_SEC),
-        .tv_nsec = (suseconds_t)((usec % USEC_PER_SEC) * NSEC_PER_USEC)
-    };
-
-    errno = 0;
-    int ret = 0;
-    while( (ret = clock_nanosleep(clock, TIMER_ABSTIME, &req, NULL)) != 0 ) {
-        if(ret == EINTR) {
-            errno = 0;
-            continue;
-        }
-        else {
-            if (ret == EINVAL) {
-                if (!einval_printed) {
-                    einval_printed++;
-                    netdata_log_error("Invalid time given to clock_nanosleep(): clockid = %d, tv_sec = %lld, tv_nsec = %ld",
-                                      clock,
-                                      (long long)req.tv_sec,
-                                      req.tv_nsec);
-                }
-            } else if (ret == ENOTSUP) {
-                if (!enotsup_printed) {
-                    enotsup_printed++;
-                    netdata_log_error("Invalid clock id given to clock_nanosleep(): clockid = %d, tv_sec = %lld, tv_nsec = %ld",
-                                      clock,
-                                      (long long)req.tv_sec,
-                                      req.tv_nsec);
-                }
-            } else {
-                if (!eunknown_printed) {
-                    eunknown_printed++;
-                    netdata_log_error("Unknown return value %d from clock_nanosleep(): clockid = %d, tv_sec = %lld, tv_nsec = %ld",
-                                      ret,
-                                      clock,
-                                      (long long)req.tv_sec,
-                                      req.tv_nsec);
-                }
-            }
-            sleep_usec(usec);
-        }
-    }
-};
-#endif
-
-#define HEARTBEAT_ALIGNMENT_STATISTICS_SIZE 10
-netdata_mutex_t heartbeat_alignment_mutex = NETDATA_MUTEX_INITIALIZER;
-static size_t heartbeat_alignment_id = 0;
-
-struct heartbeat_thread_statistics {
-    size_t sequence;
-    usec_t dt;
-};
-static struct heartbeat_thread_statistics heartbeat_alignment_values[HEARTBEAT_ALIGNMENT_STATISTICS_SIZE] = { 0 };
-
-void heartbeat_statistics(usec_t *min_ptr, usec_t *max_ptr, usec_t *average_ptr, size_t *count_ptr) {
-    struct heartbeat_thread_statistics current[HEARTBEAT_ALIGNMENT_STATISTICS_SIZE];
-    static struct heartbeat_thread_statistics old[HEARTBEAT_ALIGNMENT_STATISTICS_SIZE] = { 0 };
-
-    memcpy(current, heartbeat_alignment_values, sizeof(struct heartbeat_thread_statistics) * HEARTBEAT_ALIGNMENT_STATISTICS_SIZE);
-
-    usec_t min = 0, max = 0, total = 0, average = 0;
-    size_t i, count = 0;
-    for(i = 0; i < HEARTBEAT_ALIGNMENT_STATISTICS_SIZE ;i++) {
-        if(current[i].sequence == old[i].sequence) continue;
-        usec_t value = current[i].dt - old[i].dt;
-
-        if(!count) {
-            min = max = total = value;
-            count = 1;
-        }
-        else {
-            total += value;
-            if(value < min) min = value;
-            if(value > max) max = value;
-            count++;
-        }
-    }
-    if(count)
-        average = total / count;
-
-    if(min_ptr) *min_ptr = min;
-    if(max_ptr) *max_ptr = max;
-    if(average_ptr) *average_ptr = average;
-    if(count_ptr) *count_ptr = count;
-
-    memcpy(old, current, sizeof(struct heartbeat_thread_statistics) * HEARTBEAT_ALIGNMENT_STATISTICS_SIZE);
-}
-
-inline void heartbeat_init(heartbeat_t *hb) {
-    hb->realtime = 0ULL;
-    hb->randomness = (usec_t)250 * USEC_PER_MS + ((usec_t)(now_realtime_usec() * clock_realtime_resolution) % (250 * USEC_PER_MS));
-    hb->randomness -= (hb->randomness % clock_realtime_resolution);
-
-    netdata_mutex_lock(&heartbeat_alignment_mutex);
-    hb->statistics_id = heartbeat_alignment_id;
-    heartbeat_alignment_id++;
-    netdata_mutex_unlock(&heartbeat_alignment_mutex);
-
-    if(hb->statistics_id < HEARTBEAT_ALIGNMENT_STATISTICS_SIZE) {
-        heartbeat_alignment_values[hb->statistics_id].dt = 0;
-        heartbeat_alignment_values[hb->statistics_id].sequence = 0;
-    }
-}
-
-// 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) {
-    if(unlikely(hb->randomness > tick / 2)) {
-        // TODO: The heartbeat tick should be specified at the heartbeat_init() function
-        usec_t tmp = (now_realtime_usec() * clock_realtime_resolution) % (tick / 2);
-
-        nd_log_limit_static_global_var(erl, 10, 0);
-        nd_log_limit(&erl, NDLS_DAEMON, NDLP_NOTICE,
-                     "heartbeat randomness of %"PRIu64" is too big for a tick of %"PRIu64" - setting it to %"PRIu64"",
-                     hb->randomness, tick, tmp);
-        hb->randomness = tmp;
-    }
-
-    usec_t dt;
-    usec_t now = now_realtime_usec();
-    usec_t next = now - (now % tick) + tick + hb->randomness;
-
-    // align the next time we want to the clock resolution
-    if(next % clock_realtime_resolution)
-        next = next - (next % clock_realtime_resolution) + clock_realtime_resolution;
-
-    // sleep_usec() has a loop to guarantee we will sleep for at least the requested time.
-    // According the specs, when we sleep for a relative time, clock adjustments should not affect the duration
-    // we sleep.
-    sleep_usec_with_now(next - now, now);
-    now = now_realtime_usec();
-    dt = now - hb->realtime;
-
-    if(hb->statistics_id < HEARTBEAT_ALIGNMENT_STATISTICS_SIZE) {
-        heartbeat_alignment_values[hb->statistics_id].dt += now - next;
-        heartbeat_alignment_values[hb->statistics_id].sequence++;
-    }
-
-    if(unlikely(now < next)) {
-        errno = 0;
-        nd_log_limit_static_global_var(erl, 10, 0);
-        nd_log_limit(&erl, NDLS_DAEMON, NDLP_NOTICE,
-                     "heartbeat clock: woke up %"PRIu64" microseconds earlier than expected "
-                     "(can be due to the CLOCK_REALTIME set to the past).",
-                     next - now);
-    }
-    else if(unlikely(now - next >  tick / 2)) {
-        errno = 0;
-        nd_log_limit_static_global_var(erl, 10, 0);
-        nd_log_limit(&erl, NDLS_DAEMON, NDLP_NOTICE,
-                     "heartbeat clock: woke up %"PRIu64" microseconds later than expected "
-                     "(can be due to system load or the CLOCK_REALTIME set to the future).",
-                     now - next);
-    }
-
-    if(unlikely(!hb->realtime)) {
-        // the first time return zero
-        dt = 0;
-    }
-
-    hb->realtime = now;
-    return dt;
-}
-
-void sleep_usec_with_now(usec_t usec, usec_t started_ut) {
-    // we expect microseconds (1.000.000 per second)
-    // but timespec is nanoseconds (1.000.000.000 per second)
-    struct timespec rem = { 0, 0 }, req = {
-            .tv_sec = (time_t) (usec / USEC_PER_SEC),
-            .tv_nsec = (suseconds_t) ((usec % USEC_PER_SEC) * NSEC_PER_USEC)
-    };
-
-    // make sure errno is not EINTR
-    errno = 0;
-
-    if(!started_ut)
-        started_ut = now_realtime_usec();
-
-    usec_t end_ut = started_ut + usec;
-
-    while (nanosleep(&req, &rem) != 0) {
-        if (likely(errno == EINTR && (rem.tv_sec || rem.tv_nsec))) {
-            req = rem;
-            rem = (struct timespec){ 0, 0 };
-
-            // break an infinite loop
-            errno = 0;
-
-            usec_t now_ut = now_realtime_usec();
-            if(now_ut >= end_ut)
-                break;
-
-            usec_t remaining_ut = (usec_t)req.tv_sec * USEC_PER_SEC + (usec_t)req.tv_nsec * NSEC_PER_USEC > usec;
-            usec_t check_ut = now_ut - started_ut;
-            if(remaining_ut > check_ut) {
-                req = (struct timespec){
-                        .tv_sec = (time_t) ( check_ut / USEC_PER_SEC),
-                        .tv_nsec = (suseconds_t) ((check_ut % USEC_PER_SEC) * NSEC_PER_USEC)
-                };
-            }
-        }
-        else {
-            netdata_log_error("Cannot nanosleep() for %"PRIu64" microseconds.", usec);
-            break;
-        }
-    }
-}
-
-static inline collected_number uptime_from_boottime(void) {
-#ifdef CLOCK_BOOTTIME_IS_AVAILABLE
-    return (collected_number)(now_boottime_usec() / USEC_PER_MS);
-#else
-    netdata_log_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)) {
-        netdata_log_error("/proc/uptime has no lines.");
-        return 0;
-    }
-    if(unlikely(procfile_linewords(read_proc_uptime_ff, 0) < 1)) {
-        netdata_log_error("/proc/uptime has less than 1 word in it.");
-        return 0;
-    }
-
-    return (collected_number)(strtondd(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);
-            netdata_log_info("Using now_boottime_usec() for uptime (dt is %lld ms)", delta);
-            use_boottime = 1;
-        }
-        else if(uptime_proc != 0) {
-            netdata_log_info("Using /proc/uptime for uptime (dt is %lld ms)", delta);
-            use_boottime = 0;
-        }
-        else {
-            netdata_log_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;
-}
diff --git a/libnetdata/clocks/clocks.h b/libnetdata/clocks/clocks.h
deleted file mode 100644
index 2beb14ed9..000000000
--- a/libnetdata/clocks/clocks.h
+++ /dev/null
@@ -1,162 +0,0 @@
-// SPDX-License-Identifier: GPL-3.0-or-later
-
-#ifndef NETDATA_CLOCKS_H
-#define NETDATA_CLOCKS_H 1
-
-#include "../libnetdata.h"
-
-#ifndef HAVE_STRUCT_TIMESPEC
-struct timespec {
-    time_t tv_sec;  /* seconds */
-    long   tv_nsec; /* nanoseconds */
-};
-#endif
-
-#ifndef HAVE_CLOCKID_T
-typedef int clockid_t;
-#endif
-
-typedef uint64_t nsec_t;
-typedef uint64_t msec_t;
-typedef uint64_t usec_t;
-typedef int64_t  susec_t;
-
-typedef struct heartbeat {
-    usec_t realtime;
-    usec_t randomness;
-    size_t statistics_id;
-} heartbeat_t;
-
-/* Linux value is as good as any other */
-#ifndef CLOCK_REALTIME
-#define CLOCK_REALTIME  0
-#endif
-
-#ifndef CLOCK_MONOTONIC
-/* fallback to CLOCK_REALTIME if not available */
-#define CLOCK_MONOTONIC CLOCK_REALTIME
-#endif
-
-#ifndef CLOCK_BOOTTIME
-
-#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_REALTIME */
-#define CLOCK_BOOTTIME  CLOCK_REALTIME
-#endif // CLOCK_UPTIME
-
-#else // CLOCK_BOOTTIME
-
-#ifdef HAVE_CLOCK_GETTIME
-#define CLOCK_BOOTTIME_IS_AVAILABLE 1 // required for /proc/uptime
-#endif // HAVE_CLOCK_GETTIME
-
-#endif // CLOCK_BOOTTIME
-
-#ifndef NSEC_PER_MSEC
-#define NSEC_PER_MSEC   1000000ULL
-#endif
-
-#ifndef NSEC_PER_SEC
-#define NSEC_PER_SEC    1000000000ULL
-#endif
-#ifndef NSEC_PER_USEC
-#define NSEC_PER_USEC   1000ULL
-#endif
-
-#ifndef USEC_PER_SEC
-#define USEC_PER_SEC    1000000ULL
-#endif
-#ifndef MSEC_PER_SEC
-#define MSEC_PER_SEC    1000ULL
-#endif
-
-#define USEC_PER_MS     1000ULL
-
-#ifndef HAVE_CLOCK_GETTIME
-/* Fallback function for POSIX.1-2001 clock_gettime() function.
- *
- * We use a realtime clock from gettimeofday(), this will
- * make systems without clock_gettime() support sensitive
- * to time jumps or hibernation/suspend side effects.
- */
-int clock_gettime(clockid_t clk_id, struct timespec *ts);
-#endif
-
-/*
- * 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 appropriate clock, or 0 on error.
- * All now_*_usec() functions return the time in microseconds from the appropriate clock, or 0 on error.
- *
- */
-int now_realtime_timeval(struct timeval *tv);
-time_t now_realtime_sec(void);
-usec_t now_realtime_usec(void);
-
-int now_monotonic_timeval(struct timeval *tv);
-time_t now_monotonic_sec(void);
-msec_t now_realtime_msec(void);
-usec_t now_monotonic_usec(void);
-int now_monotonic_high_precision_timeval(struct timeval *tv);
-time_t now_monotonic_high_precision_sec(void);
-usec_t now_monotonic_high_precision_usec(void);
-
-int now_boottime_timeval(struct timeval *tv);
-time_t now_boottime_sec(void);
-usec_t now_boottime_usec(void);
-
-usec_t timeval_usec(struct timeval *tv);
-msec_t timeval_msec(struct timeval *tv);
-
-usec_t dt_usec(struct timeval *now, struct timeval *old);
-susec_t dt_usec_signed(struct timeval *now, struct timeval *old);
-
-void heartbeat_init(heartbeat_t *hb);
-
-/* Sleeps until next multiple of tick using monotonic clock.
- * Returns elapsed time in microseconds since previous heartbeat
- */
-usec_t heartbeat_next(heartbeat_t *hb, usec_t tick);
-
-void heartbeat_statistics(usec_t *min_ptr, usec_t *max_ptr, usec_t *average_ptr, size_t *count_ptr);
-
-void sleep_usec_with_now(usec_t usec, usec_t started_ut);
-#define sleep_usec(usec) sleep_usec_with_now(usec, 0);
-
-void clocks_init(void);
-
-// lower level functions - avoid using directly
-time_t now_sec(clockid_t clk_id);
-usec_t now_usec(clockid_t clk_id);
-int now_timeval(clockid_t clk_id, struct timeval *tv);
-
-collected_number uptime_msec(char *filename);
-
-extern usec_t clock_monotonic_resolution;
-extern usec_t clock_realtime_resolution;
-
-void sleep_to_absolute_time(usec_t usec);
-
-#endif /* NETDATA_CLOCKS_H */