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author | Waley Chen <waleycz@gmail.com> | 2016-04-15 02:58:33 -0400 |
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committer | Waley Chen <waleycz@gmail.com> | 2016-04-15 02:58:33 -0400 |
commit | c2041cd99ea8ff1aa8bfba2d4bcb3bbd2ea7932c (patch) | |
tree | 1a7b9828a9883d470c5f85322371eff738279731 /src/mongo/util/background_thread_clock_source.cpp | |
parent | 7850673c0303b740ecdd2b8718d8c745e25884b3 (diff) | |
download | mongo-c2041cd99ea8ff1aa8bfba2d4bcb3bbd2ea7932c.tar.gz |
SERVER-23243 Extract time-keeping from Listener
BackgroundThreadClockSource & FastClockSourceFactory
Diffstat (limited to 'src/mongo/util/background_thread_clock_source.cpp')
-rw-r--r-- | src/mongo/util/background_thread_clock_source.cpp | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/src/mongo/util/background_thread_clock_source.cpp b/src/mongo/util/background_thread_clock_source.cpp new file mode 100644 index 00000000000..96dececff9c --- /dev/null +++ b/src/mongo/util/background_thread_clock_source.cpp @@ -0,0 +1,80 @@ +/** + * Copyright (C) 2016 MongoDB Inc. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License, version 3, + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * As a special exception, the copyright holders give permission to link the + * code of portions of this program with the OpenSSL library under certain + * conditions as described in each individual source file and distribute + * linked combinations including the program with the OpenSSL library. You + * must comply with the GNU Affero General Public License in all respects for + * all of the code used other than as permitted herein. If you modify file(s) + * with this exception, you may extend this exception to your version of the + * file(s), but you are not obligated to do so. If you do not wish to do so, + * delete this exception statement from your version. If you delete this + * exception statement from all source files in the program, then also delete + * it in the license file. + */ + +#include "mongo/platform/basic.h" + +#include "mongo/util/background_thread_clock_source.h" + +#include <chrono> +#include <thread> + +#include "mongo/stdx/memory.h" +#include "mongo/stdx/thread.h" +#include "mongo/util/time_support.h" + +namespace mongo { + +BackgroundThreadClockSource::BackgroundThreadClockSource(std::unique_ptr<ClockSource> clockSource, + Milliseconds granularity) + : _clockSource(std::move(clockSource)), _granularity(granularity), _shutdownTimer(false) { + _updateCurrent(); + _startTimerThread(); +} + +BackgroundThreadClockSource::~BackgroundThreadClockSource() { + { + stdx::unique_lock<stdx::mutex> lock(_mutex); + _shutdownTimer = true; + _condition.notify_one(); + } + + _timer.join(); +} + +Date_t BackgroundThreadClockSource::now() { + return Date_t::fromMillisSinceEpoch(_current.load()); +} + +void BackgroundThreadClockSource::_startTimerThread() { + // Start the background thread that repeatedly sleeps for the specified duration of milliseconds + // and wakes up to store the current time. + _timer = stdx::thread([&]() { + stdx::unique_lock<stdx::mutex> lock(_mutex); + while (!_shutdownTimer) { + if (_condition.wait_for(lock, _granularity) == stdx::cv_status::timeout) { + _updateCurrent(); + } + } + }); +} + +void BackgroundThreadClockSource::_updateCurrent() { + _current.store(_clockSource->now().toMillisSinceEpoch()); +} + +} // namespace mongo |