/*
 * Copyright (c) 2020 - Adjacent Link LLC, Bridgewater, New Jersey
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * 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.
 * * Neither the name of Adjacent Link LLC nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * 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 OWNER 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 EMANEUTILPROCESSINGPOOL_HEADER_
#define EMANEUTILPROCESSINGPOOL_HEADER_

#include "emane/utils/functionwrapper.h"

#include <deque>
#include <thread>
#include <mutex>
#include <vector>
#include <future>
#include <condition_variable>

namespace EMANE
{
  namespace Utils
  {
    class ProcessingPool
    {
    public:
      ProcessingPool();

      ~ProcessingPool();

      void start(std::size_t size);

      void stop();

      bool isRunning() const;

      template<typename Function>
      std::future<typename std::result_of<Function()>::type>
      submit(Function f);

    private:
      std::mutex mutex_;
      std::condition_variable cond_;
      std::vector<std::thread> threads_;
      bool bCancel_;

      using ProcessingQueue = std::deque<FunctionWrapper>;
      ProcessingQueue queue_;

      void worker();
    };
  }
}

#include "emane/utils/processingpool.inl"

#endif // EMANEUTILPROCESSINGPOOL_HEADER_
