133 lines
3.7 KiB
C++
133 lines
3.7 KiB
C++
/*
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#pragma once
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#include <chrono>
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#include <ctime>
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#include <stdexcept>
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#include <type_traits>
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#include <folly/Portability.h>
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#include <folly/lang/Exception.h>
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#include <folly/portability/Time.h>
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namespace folly {
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namespace chrono {
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/* using override */ using std::chrono::abs;
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/* using override */ using std::chrono::ceil;
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/* using override */ using std::chrono::floor;
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/* using override */ using std::chrono::round;
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// steady_clock_spec
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//
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// All clocks with this spec share epoch and tick rate.
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struct steady_clock_spec {};
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// system_clock_spec
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//
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// All clocks with this spec share epoch and tick rate.
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struct system_clock_spec {};
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// clock_traits
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//
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// Detects and reexports per-clock traits.
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//
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// Specializeable for clocks for which trait detection fails..
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template <typename Clock>
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struct clock_traits {
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private:
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template <typename C>
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using detect_spec_ = typename C::folly_spec;
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public:
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using spec = detected_or_t<void, detect_spec_, Clock>;
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};
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template <>
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struct clock_traits<std::chrono::steady_clock> {
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using spec = steady_clock_spec;
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};
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template <>
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struct clock_traits<std::chrono::system_clock> {
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using spec = system_clock_spec;
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};
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struct coarse_steady_clock {
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using folly_spec = steady_clock_spec;
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using duration = std::chrono::steady_clock::duration;
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using rep = duration::rep;
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using period = duration::period;
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using time_point = std::chrono::time_point<coarse_steady_clock>;
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constexpr static bool is_steady = true;
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static time_point now() noexcept {
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#ifndef CLOCK_MONOTONIC_COARSE
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auto time = std::chrono::steady_clock::now().time_since_epoch();
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#else
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timespec ts;
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int ret = clock_gettime(CLOCK_MONOTONIC_COARSE, &ts);
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if (kIsDebug && (ret != 0)) {
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throw_exception<std::runtime_error>(
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"Error using CLOCK_MONOTONIC_COARSE.");
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}
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auto time =
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std::chrono::seconds(ts.tv_sec) + std::chrono::nanoseconds(ts.tv_nsec);
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#endif
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return time_point(std::chrono::duration_cast<duration>(time));
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}
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};
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struct coarse_system_clock {
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using folly_spec = system_clock_spec;
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using duration = std::chrono::system_clock::duration;
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using rep = duration::rep;
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using period = duration::period;
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using time_point = std::chrono::time_point<coarse_system_clock>;
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constexpr static bool is_steady = false;
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static time_point now() noexcept {
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#ifndef CLOCK_REALTIME_COARSE
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auto time = std::chrono::system_clock::now().time_since_epoch();
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#else
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timespec ts;
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int ret = clock_gettime(CLOCK_REALTIME_COARSE, &ts);
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if (kIsDebug && (ret != 0)) {
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throw_exception<std::runtime_error>("Error using CLOCK_REALTIME_COARSE.");
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}
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auto time =
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std::chrono::seconds(ts.tv_sec) + std::chrono::nanoseconds(ts.tv_nsec);
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#endif
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return time_point(std::chrono::duration_cast<duration>(time));
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}
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static std::time_t to_time_t(const time_point& t) noexcept {
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auto d = t.time_since_epoch();
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return std::chrono::duration_cast<std::chrono::seconds>(d).count();
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}
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static time_point from_time_t(std::time_t t) noexcept {
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return time_point(
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std::chrono::duration_cast<duration>(std::chrono::seconds(t)));
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}
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};
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} // namespace chrono
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} // namespace folly
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