Clock.h

Go to the documentation of this file.

/*
 * i6engine
 * Copyright (2016) Daniel Bonrath, Michael Baer, All rights reserved.
 *
 * This file is part of i6engine; i6engine is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef __I6ENGINE_UTILS_CLOCK_H__
#define __I6ENGINE_UTILS_CLOCK_H__

#include <atomic>
#include <cassert>
#include <climits>
#include <condition_variable>
#include <vector>

#include "boost/bind.hpp"

namespace i6e {
namespace utils {

        template<class Updater>
        class Clock : public Updater {
        public:
                Clock() : Updater(boost::bind(&Clock::Update, this)), _timer(), _lock(), _systemTime(0), _running(true) {
                        Updater::Init();
                }

                ~Clock() {
                        _running = false;
                        Updater::Stop();
                        for (size_t i = 0; i < _timer.size(); i++) {
                                _timer[i].second->notify_all();
                                delete _timer[i].second;
                        }
                        _timer.clear();
                }

                void Update() {
                        // Get current time.
                        _systemTime = Updater::getCurrentTime(_systemTime);
                        notifyTimer();
                }

                inline uint64_t getTime() const {
                        return _systemTime;
                }

                uint64_t registerTimer() {
                        std::pair<uint64_t, std::condition_variable *> p(std::make_pair(UINT64_MAX, new std::condition_variable()));

                        std::lock_guard<std::mutex> lock(_lock);
                        _timer.push_back(p);

                        return _timer.size() - 1;
                }

                void unregisterTimer(uint64_t timerID) {
                        std::lock_guard<std::mutex> lock(_lock);
                        _timer[timerID].first = UINT64_MAX;
                }

                void updateWaitTime(uint64_t timerID, uint64_t time) {
                        if (time <= _systemTime) {
                                std::lock_guard<std::mutex> lock(_lock);
                                std::condition_variable * cond = _timer[size_t(timerID)].second;
                                cond->notify_all();
                                return;
                        }
                        std::lock_guard<std::mutex> lock(_lock);
                        _timer[size_t(timerID)].first = time;
                }

                bool waitForTime(uint64_t timerID, uint64_t time) {
                        if (time <= _systemTime) {
                                return true;
                        }
                        std::unique_lock<std::mutex> lock(_lock);
                        _timer[size_t(timerID)].first = time;
                        _timer[size_t(timerID)].second->wait(lock);
                        return _running;
                }

                bool isRunning() const {
                        return _running;
                }

        private:
                //                              wakeuptime      variable
                std::vector<std::pair<uint64_t, std::condition_variable *>> _timer;

                mutable std::mutex _lock;

                // last system time
                std::atomic<uint64_t> _systemTime;

                std::atomic<bool> _running;

                void notifyTimer() {
                        std::unique_lock<std::mutex> lock(_lock);
                        for (size_t i = 0; i < _timer.size(); i++) {
                                if (_systemTime >= _timer[i].first) {
                                        _timer[i].first = UINT64_MAX;
                                        _timer[i].second->notify_all();
                                }
                        }
                }

                Clock(const Clock &) = delete;
                Clock & operator=(const Clock &) = delete;
        };

} /* namespace utils */
} /* namespace i6e */

#endif /* __I6ENGINE_UTILS_CLOCK_H__ */