/*
 * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef EMBB_DATAFLOW_INTERNAL_SCHEDULER_MTAPI_H_
#define EMBB_DATAFLOW_INTERNAL_SCHEDULER_MTAPI_H_

#include <embb/dataflow/internal/action.h>
#include <embb/dataflow/internal/scheduler.h>
#include <embb/tasks/node.h>
#include <embb/base/function.h>

#include <algorithm>

namespace embb {
namespace dataflow {
namespace internal {

class SchedulerMTAPI : public Scheduler {
 public:
  explicit SchedulerMTAPI(int slices)
    : slices_(slices) {
    embb::tasks::Node & node = embb::tasks::Node::GetInstance();

    int tl = std::min(
      static_cast<int>(node.GetTaskLimit()),
      static_cast<int>(node.GetGroupCount()));
    if (tl < slices_) {
      slices_ = tl;
    }

    group_ = reinterpret_cast<embb::tasks::Group**>(
      embb::base::Allocation::Allocate(
      sizeof(embb::tasks::Group*)*slices_));

    for (int ii = 0; ii < slices_; ii++) {
      embb::tasks::Group & group = node.CreateGroup();
      group_[ii] = &group;
    }

    queue_count_ = std::min(
      static_cast<int>(node.GetQueueCount()),
      static_cast<int>(node.GetWorkerThreadCount()) );
    queue_ = reinterpret_cast<embb::tasks::Queue**>(
      embb::base::Allocation::Allocate(
      sizeof(embb::tasks::Queue*)*queue_count_));

    for (int ii = 0; ii < queue_count_; ii++) {
      embb::tasks::Queue & queue = node.CreateQueue(0, true);
      queue_[ii] = &queue;
    }
  }
  virtual ~SchedulerMTAPI() {
    if (embb::tasks::Node::IsInitialized()) {
      // only destroy groups and queues if there still is an instance
      embb::tasks::Node & node = embb::tasks::Node::GetInstance();
      for (int ii = 0; ii < slices_; ii++) {
        group_[ii]->WaitAll(MTAPI_INFINITE);
        node.DestroyGroup(*group_[ii]);
      }
      for (int ii = 0; ii < queue_count_; ii++) {
        node.DestroyQueue(*queue_[ii]);
      }
    }
    embb::base::Allocation::Free(group_);
    embb::base::Allocation::Free(queue_);
  }
  virtual void Spawn(Action & action) {
    const int idx = action.GetClock() % slices_;
    group_[idx]->Spawn(embb::base::MakeFunction(action, &Action::RunMTAPI));
  }
  virtual void Enqueue(int process_id, Action & action) {
    const int idx = action.GetClock() % slices_;
    const int queue_id = process_id % queue_count_;
    queue_[queue_id]->Spawn(group_[idx],
      embb::base::MakeFunction(action, &Action::RunMTAPI));
  }
  virtual void WaitForSlice(int slice) {
    group_[slice]->WaitAll(MTAPI_INFINITE);
  }
  virtual int GetSlices() { return slices_; }

 private:
  embb::tasks::Group ** group_;
  embb::tasks::Queue ** queue_;
  int queue_count_;
  int slices_;
};

} // namespace internal
} // namespace dataflow
} // namespace embb

#endif // EMBB_DATAFLOW_INTERNAL_SCHEDULER_MTAPI_H_