sessiond: transition from lttng-ust to tracer agnostic API

[lttng-tools.git] / src / bin / lttng-sessiond / ust-clock.cpp

diff --git a/src/bin/lttng-sessiond/ust-clock.cpp b/src/bin/lttng-sessiond/ust-clock.cpp
deleted file mode 100644 (file)
index 3d853ad..0000000
--- a/src/bin/lttng-sessiond/ust-clock.cpp
+++ /dev/null
@@ -1,167 +0,0 @@
-/*
- * Copyright (C) 2010 Pierre-Marc Fournier
- * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com>
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- */
-
-#include "ust-clock.hpp"
-
-#include <common/time.hpp>
-#include <common/exception.hpp>
-
-#define CLOCK_OFFSET_SAMPLE_COUNT              10
-
-namespace {
-struct offset_sample {
-       /* correlation offset */
-       lttng::ust::clock_attributes_sample::scycles_t offset;
-       /* lower is better */
-       lttng::ust::clock_attributes_sample::cycles_t measure_delta;
-};
-
-lttng::ust::clock_attributes_sample::cycles_t sample_clock_read64()
-{
-       lttng_ust_clock_read64_function read64_cb;
-
-       if (lttng_ust_trace_clock_get_read64_cb(&read64_cb)) {
-               LTTNG_THROW_ERROR("Failed to get clock sample callback");
-       }
-
-       return read64_cb();
-}
-
-lttng::ust::clock_attributes_sample::cycles_t sample_clock_frequency()
-{
-       lttng_ust_clock_freq_function get_freq_cb;
-
-       if (lttng_ust_trace_clock_get_freq_cb(&get_freq_cb)) {
-               LTTNG_THROW_ERROR("Failed to get clock frequency callback");
-       }
-
-       return get_freq_cb();
-}
-
-nonstd::optional<lttng_uuid> sample_clock_uuid()
-{
-       lttng_ust_clock_uuid_function get_uuid_cb;
-
-       if (lttng_ust_trace_clock_get_uuid_cb(&get_uuid_cb)) {
-               return nonstd::nullopt;
-       }
-
-       char uuid_str[LTTNG_UUID_STR_LEN];
-       if (get_uuid_cb(uuid_str)) {
-               return nonstd::nullopt;
-       }
-
-       lttng_uuid uuid;
-       if (lttng_uuid_from_str(uuid_str, uuid)) {
-               LTTNG_THROW_ERROR("Failed to parse UUID from string");
-       }
-
-       return nonstd::optional<lttng_uuid>{uuid};
-}
-
-const char *sample_clock_name()
-{
-       lttng_ust_clock_name_function get_name_cb;
-
-       if (lttng_ust_trace_clock_get_name_cb(&get_name_cb)) {
-               LTTNG_THROW_ERROR("Failed to get clock name callback");
-       }
-
-       const auto name = get_name_cb();
-       if (!name) {
-               LTTNG_THROW_ERROR("Invalid clock name returned by LTTng-UST `lttng_ust_clock_name_function`");
-       }
-
-       return name;
-}
-
-const char *sample_clock_description()
-{
-       lttng_ust_clock_description_function get_description_cb;
-
-       if (lttng_ust_trace_clock_get_description_cb(&get_description_cb)) {
-               LTTNG_THROW_ERROR("Failed to get clock description callback");
-       }
-
-       const auto description = get_description_cb();
-       if (!description) {
-               LTTNG_THROW_ERROR("Invalid clock description returned by LTTng-UST `lttng_ust_clock_description_function`");
-       }
-
-       return description;
-}
-
-/*
- * The offset between monotonic and realtime clock can be negative if
- * the system sets the REALTIME clock to 0 after boot.
- */
-void measure_single_clock_offset(struct offset_sample *sample)
-{
-       lttng::ust::clock_attributes_sample::cycles_t monotonic_avg, monotonic[2], measure_delta,
-                       realtime;
-       const auto tcf = sample_clock_frequency();
-       struct timespec rts = { 0, 0 };
-
-       monotonic[0] = sample_clock_read64();
-       if (lttng_clock_gettime(CLOCK_REALTIME, &rts)) {
-               LTTNG_THROW_POSIX("Failed to sample time from clock", errno);
-       }
-
-       monotonic[1] = sample_clock_read64();
-       measure_delta = monotonic[1] - monotonic[0];
-       if (measure_delta > sample->measure_delta) {
-               /*
-                * Discard value if it took longer to read than the best
-                * sample so far.
-                */
-               return;
-       }
-
-       monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
-       realtime = (lttng::ust::clock_attributes_sample::cycles_t) rts.tv_sec * tcf;
-       if (tcf == NSEC_PER_SEC) {
-               realtime += rts.tv_nsec;
-       } else {
-               realtime += (lttng::ust::clock_attributes_sample::cycles_t) rts.tv_nsec * tcf /
-                               NSEC_PER_SEC;
-       }
-
-       sample->offset = (lttng::ust::clock_attributes_sample::scycles_t) realtime - monotonic_avg;
-       sample->measure_delta = measure_delta;
-}
-
-/*
- * Approximation of NTP time of day to clock monotonic correlation,
- * taken at start of trace. Keep the measurement that took the less time
- * to complete, thus removing imprecision caused by preemption.
- * May return a negative offset.
- */
-lttng::ust::clock_attributes_sample::scycles_t measure_clock_offset(void)
-{
-       struct offset_sample offset_best_sample = {
-               .offset = 0,
-               .measure_delta = UINT64_MAX,
-       };
-
-       for (auto i = 0; i < CLOCK_OFFSET_SAMPLE_COUNT; i++) {
-               measure_single_clock_offset(&offset_best_sample);
-       }
-
-       return offset_best_sample.offset;
-}
-}
-
-lttng::ust::clock_attributes_sample::clock_attributes_sample() :
-        _name{sample_clock_name()},
-        _description{sample_clock_description()},
-        _uuid{sample_clock_uuid()},
-       _offset{measure_clock_offset()},
-       _frequency{sample_clock_frequency()}
-{
-}