Line data    Source code

       1             : /*
       2             :  * This file is part of PTN Engine
       3             :  *
       4             :  * Copyright (c) 2023 Eduardo Valgôde
       5             :  *
       6             :  * Licensed under the Apache License, Version 2.0 (the "License");
       7             :  * you may not use this file except in compliance with the License.
       8             :  * You may obtain a copy of the License at
       9             :  *
      10             :  * http://www.apache.org/licenses/LICENSE-2.0
      11             :  *
      12             :  * Unless required by applicable law or agreed to in writing, software
      13             :  * distributed under the License is distributed on an "AS IS" BASIS,
      14             :  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      15             :  * See the License for the specific language governing permissions and
      16             :  * limitations under the License.
      17             :  */
      18             : 
      19             : #pragma once
      20             : 
      21             : #include <atomic>
      22             : #include <barrier>
      23             : #include <chrono>
      24             : #include <condition_variable>
      25             : #include <mutex>
      26             : #include <shared_mutex>
      27             : #include <thread>
      28             : 
      29             : namespace ptne
      30             : {
      31             : 
      32             : class IPTN_EngineEL;
      33             : class Transition;
      34             : 
      35             : //!
      36             : //! \brief The EventLoop class manages an event loop thread.
      37             : //!
      38             : class EventLoop
      39             : {
      40             : public:
      41             :         using SleepDuration = std::chrono::duration<long, std::ratio<1, 1000>>;
      42             : 
      43             :         ~EventLoop();
      44             : 
      45             :         //!
      46             :         //! \brief EventLoop
      47             :         //! \param ptnEngineInternal
      48             :         //!
      49             :         explicit EventLoop(IPTN_EngineEL &ptnEngineInternal);
      50             : 
      51             :         EventLoop(const EventLoop &) = delete;
      52             :         EventLoop(EventLoop &&) = delete;
      53             :         EventLoop &operator=(const EventLoop &) = delete;
      54             :         EventLoop &operator=(EventLoop &&) = delete;
      55             : 
      56             :         //!
      57             :         //! \brief Inform if the event loop is running.
      58             :         //! \return true if the event loop thread is running.
      59             :         //!
      60             :         bool isRunning() const;
      61             : 
      62             :         //!
      63             :         //! \brief Order the event loop to stop.
      64             :         //!
      65             :         void stop() noexcept;
      66             : 
      67             :         //!
      68             :         //! \brief Start the event loop thread.
      69             :         //! \param log Whether to log or not.
      70             :         //! \param o The output stream to write the log messages to.
      71             :         //!
      72             :         void start(const bool log, std::ostream &o);
      73             : 
      74             :         //!
      75             :         //! \brief Notify the event loop thread of a new event.
      76             :         //!
      77             :         void notifyNewEvent();
      78             : 
      79             :         //!
      80             :         //! \brief Set the event loop watchdog timer period.
      81             :         //! \param sleepTime The event loop watchdog timer period.
      82             :         //!
      83             :         void setSleepDuration(const SleepDuration sleepDuration);
      84             : 
      85             :         //!
      86             :         //! \brief Get the event loop watchdog timer period.
      87             :         //! \return The event loop watchdog timer period.
      88             :         //!
      89             :         SleepDuration getSleepDuration() const;
      90             : 
      91             : private:
      92             :         //!
      93             :         //! \brief Event loop function.
      94             :         //! \param log Flag to turn on logging on or off.
      95             :         //! \param o Log where to write log messages.
      96             :         //!
      97             :         void run(std::stop_token stopToken, const bool log, std::ostream &o);
      98             : 
      99             :         //! Reference to the petri net engine.
     100             :         IPTN_EngineEL &m_ptnEngine;
     101             : 
     102             :         //! Barrier to synchronize the event loop thread.
     103             :         std::unique_ptr<std::barrier<>> m_barrier = nullptr;
     104             : 
     105             :         //! Event loop thread.
     106             :         std::jthread m_eventLoopThread;
     107             : 
     108             :         //! Flag if the event loop thread is running.
     109             :         std::atomic<bool> m_eventLoopThreadRunning = false;
     110             : 
     111             :         //! Condition variable to wake up the event loop thread when some event happens.
     112             :         std::condition_variable m_eventNotifier;
     113             : 
     114             :         //! Mutex protecting the event notifier condition variable m_eventNotifier.
     115             :         mutable std::mutex m_eventNotifierMutex;
     116             : 
     117             :         //! While idle, watchdog timer period.
     118          78 :         SleepDuration m_sleepDuration = std::chrono::milliseconds(100);
     119             : 
     120             :         //! Mutex protecting m_sleepDuration.
     121             :         mutable std::shared_mutex m_sleepDurationMutex;
     122             : };
     123             : 
     124             : } // namespace ptne