resourcePool.hpp

/*
  ANCH Framework: ANother C++ Hack is a C++ framework based on C++11 standard
  Copyright (C) 2012 Vincent Lachenal
 
  This file is part of ANCH Framework.
 
  ANCH Framework 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 3 of the License, or
  (at your option) any later version.
 
  ANCH Framework 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 ANCH Framework.  If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
 
#include <memory>
#include <mutex>
#include <chrono>
#include <condition_variable>
#include <deque>
#include <atomic>
#include <string>
 
 
namespace anch {

  template<typename T>
  concept Validable = requires(const T& object) {
    {object.isValid()} -> std::convertible_to<bool>;
  };

  class TimeoutException: std::exception {
 
    // Attributes +
  private:
    std::chrono::milliseconds _timeout;

    std::string _msg;
    // Attributes -
 
    // Constructors +
  public:
    TimeoutException(const std::chrono::milliseconds& timeout, const std::string msg) noexcept: std::exception(),
      _timeout(timeout),
      _msg(msg) {
    }
    // Constructors -
 
    // Destructor +
  public:
    virtual ~TimeoutException() {
      // nothing to do
    }
    // Destructor -
 
    // Accessors +
  public:
    virtual const char* what() const noexcept {
      return _msg.data();
    }

    inline const std::chrono::milliseconds& getTimeout() const noexcept {
      return _timeout;
    }
    // Accessors -
 
  };
 
  // PoolableResource internal usage class declaration ; you can look at implementation but you should use auto keyword
  template<anch::Validable T, typename C, std::shared_ptr<T>(*make_ptr)(const C&)>
  class PoolableResource;

  template<anch::Validable T, typename C, std::shared_ptr<T>(*make_ptr)(const C&) = std::make_shared<T> >
  class ResourcePool {
 
    friend class PoolableResource<T,C,make_ptr>;
 
    // Attributes +
  private:
    std::mutex _mutex;

    std::condition_variable _wait;

    std::mutex _waitex;

    std::deque<std::shared_ptr<T> > _availables;

    std::size_t _maxSize;

    std::atomic_size_t _used;

    C _config;

    std::chrono::milliseconds _timeout;
    // Attributes -
 
    // Constructors +
  public:
    ResourcePool(const C& config,
                 std::size_t maxSize,
                 std::size_t initialiSize = 0,
                 std::chrono::milliseconds timeout = std::chrono::milliseconds(100));

    ResourcePool(const ResourcePool&) = delete;
    // Constructors -
 
    // Destructor +
  public:
    virtual ~ResourcePool();
    // Destructor -
 
    // Methods +
  public:
    anch::PoolableResource<T,C,make_ptr> borrowResource();
 
  private:
    void returnResource(std::shared_ptr<T> res);

    void invalidateResource(std::shared_ptr<T> res);
    // Methods -
 
    // Accessors +
  public:
    void setTimeout(const std::chrono::milliseconds timeout);
    // Accessors -
 
  };
 
}
 
#include "impl/resourcePool.hpp"