artis-star/src/artis-star/kernel/pdevs/multithreading/Coordinator.hpp

/**
 * @file kernel/pdevs/multithreading/Coordinator.hpp
 * @author The ARTIS Development Team
 * See the AUTHORS or Authors.txt file
 */

/*
 * ARTIS - the multimodeling and simulation environment
 * This file is a part of the ARTIS environment
 *
 * Copyright (C) 2013-2021 ULCO http://www.univ-littoral.fr
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef PDEVS_MULTITHREADING_COORDINATOR
#define PDEVS_MULTITHREADING_COORDINATOR

#include <artis-star/common/utils/Multithreading.hpp>
#include <artis-star/kernel/pdevs/Coordinator.hpp>

#include <thread>

namespace artis {
namespace pdevs {
namespace multithreading {

template<class Time>
struct start_message
{
  explicit start_message(typename Time::type t)
      : _t(t)
  {}

  typename Time::type _t;
};

template<class Time>
struct transition_message
{
  explicit transition_message(typename Time::type t)
      : _t(t)
  {}

  typename Time::type _t;
};

template<class Time>
struct done_start_message
{
  explicit done_start_message(typename Time::type tn,
                              common::Model <Time> *child)
      :
      _tn(tn), _child(child)
  {}

  typename Time::type _tn;
  common::Model <Time> *_child;
};

template<class Time>
struct done_transition_message
{
  explicit done_transition_message(typename Time::type tn,
                                   common::Model <Time> *child)
      :
      _tn(tn), _child(child)
  {}

  typename Time::type _tn;
  common::Model <Time> *_child;
};

template<class Time,
    class GraphManager,
    class Parameters = common::NoParameters,
    class GraphParameters = common::NoParameters>
class Coordinator
    : public pdevs::Coordinator<Time, GraphManager, Parameters, GraphParameters>
{
  typedef pdevs::Coordinator<Time, GraphManager,
                             Parameters, GraphParameters> parent_type;
  typedef Coordinator<Time, GraphManager,
                      Parameters, GraphParameters> type;
  typedef done_start_message<Time> done_start_message_type;
  typedef start_message<Time> start_message_type;
  typedef done_transition_message<Time> done_transition_message_type;
  typedef transition_message<Time> transition_message_type;

public:
  Coordinator(const std::string &name, const Parameters &parameters,
              const GraphParameters &graph_parameters)
      :
      common::Model<Time>(name),
      pdevs::Coordinator<Time, GraphManager, Parameters, GraphParameters>(
          name, parameters, graph_parameters)
  {
    type::_graph_manager.init();
    _thread = std::make_shared<std::thread>([&] { loop(); });
  }

  virtual ~Coordinator()
  {
    done();
    _thread->join();
  }

  void done()
  { get_sender().send(artis::common::Close()); }

  artis::common::Sender get_sender()
  { return _incoming.get_sender(); }

  void set_sender(common::Sender sender)
  { _sender = sender; }

  void loop()
  {
    try {
      while (true) {
        _incoming.wait()
            .template handle<start_message_type>(
                [this](start_message_type const &msg) {
                  typename Time::type tn = start(msg._t);
                  _sender.send(done_start_message_type(tn, this));
                })
            .
                template handle<done_start_message_type>(
                [this](done_start_message_type const &msg) {
                  type::_event_table.init(msg._tn, msg._child);
                  --_received;
                  if (_received == 0) {
                    std::unique_lock <std::mutex> lock(_received_mutex);

                    _condition.notify_one();
                  }
                })
            .
                template handle<transition_message_type>(
                [this](transition_message_type const &msg) {
                  typename Time::type tn = transition(msg._t);
                  _sender.send(done_transition_message_type(tn, this));
                })
            .
                template handle<done_transition_message_type>(
                [this](done_transition_message_type const &msg) {
                  type::_event_table.put(msg._tn, msg._child);
                  --_received;
                  if (_received == 0) {
                    std::unique_lock <std::mutex> lock(_received_mutex);

                    _condition.notify_one();
                  }
                });
      }
    }
    catch (artis::common::Close const &) {
    }
  }

  typename Time::type start(const typename Time::type &t)
  {
    _received = 0;
    for (auto &child : parent_type::_graph_manager.children()) {
      if (child->is_atomic()) {
        type::_event_table.init(child->start(type::_tn), child);
      } else {
        ++_received;
      }
    }

    if (_received > 0) {
      std::unique_lock <std::mutex> lock(_received_mutex);

      type::_graph_manager.start(t);
      _condition.wait(lock);
    }

    type::_tl = t;
    type::_tn = type::_event_table.get_current_time();
    return type::_tn;
  }

  // TODO: to remove
  virtual int get_receiver_number(typename Time::type t)
  {
    return type::_event_table.get_current_models(t).size();
  }

  typename Time::type transition(const typename Time::type &t)
  {
    assert(t >= type::_tl and t <= type::_tn);

    common::Models <Time> receivers = type::get_receivers();
//  common::Models<Time> IMM = type::_event_table.get_current_models(t);
    common::Models <Time> IMM =
        type::_event_table.get_current_models(t, type::_graph_manager.lookahead(t));

    _received = 0;
    for (auto &model : receivers) {
      if (model->is_atomic()) {
        type::_event_table.put(model->transition(t), model);
      } else {
        ++_received;
      }
    }
    for (auto &model : IMM) {
      if (std::find(receivers.begin(), receivers.end(), model) == receivers.end()) {
        if (model->is_atomic()) {
          type::_event_table.put(model->transition(t), model);
        } else {
          ++_received;
        }
      }
    }

    if (_received > 0) {
      std::unique_lock <std::mutex> lock(_received_mutex);

      type::_graph_manager.transition(receivers, t);
      type::_graph_manager.transition(IMM, t);
      _condition.wait(lock);
    }

    parent_type::update_event_table(t);
    type::_tl = t;
    type::_tn = type::_event_table.get_current_time();
    type::clear_bag();

    return type::_tn;
  }

private:
  std::shared_ptr <std::thread> _thread;
  artis::common::Receiver _incoming;
  artis::common::Sender _sender;
  unsigned int _received;
  std::mutex _received_mutex;
  std::condition_variable _condition;
};

}
}
} // namespace artis pdevs multithreading

#endif