/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2007 Georgia Tech Research Corporation, INRIA

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * 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, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * Authors: George Riley <riley@ece.gatech.edu>

 *          Gustavo Carneiro <gjcarneiro@gmail.com>,

 *          Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#ifndef SIMPLE_REF_COUNT_H

#define SIMPLE_REF_COUNT_H

#include "empty.h"

#include <stdint.h>

namespace ns3 {

/**

 * \brief A template-based reference counting class

 *

 * This template can be used to give reference-counting powers

 * to a class. This template does not require this class to

 * have a virtual destructor or no parent class.

 * 

 * Note: if you are moving to this template from the RefCountBase class,

 * you need to be careful to mark appropriately your destructor virtual

 * if needed. i.e., if your class has subclasses, _do_ mark your destructor

 * virtual.

 *

 * \internal

 * Note: we rely on the fairly common EBCO (empty base class optimization)

 * to get rid of the empty parent when the user does not provide

 * a non-trivial parent.

 */

template <typename T, typename PARENT = empty>

class SimpleRefCount : public PARENT

{

public:

  SimpleRefCount ()

    : m_count (1)

  {}

  SimpleRefCount (const SimpleRefCount &o)

    : m_count (1)

  {}

  SimpleRefCount &operator = (const SimpleRefCount &o)

  {

    return *this;

  }

  /**

   * Increment the reference count. This method should not be called

   * by user code. SimpleRefCount instances are expected to be used in

   * conjunction with the Ptr template which would make calling Ref

   * unecessary and dangerous.

   */

  inline void Ref (void) const

  {

    m_count++;

  }

  /**

   * Decrement the reference count. This method should not be called

   * by user code. SimpleRefCount instances are expected to be used in 

   * conjunction with the Ptr template which would make calling Ref

   * unecessary and dangerous.

   */

  inline void Unref (void) const

  {

    m_count--;

    if (m_count == 0)

      {

	delete static_cast<T*> (const_cast<SimpleRefCount *> (this));

      }

  }

  /**

   * Get the reference count of the object.  

   * Normally not needed; for language bindings.

   */

  uint32_t GetReferenceCount (void) const

  {

    return m_count;

  }

private:

  // Note we make this mutable so that the const methods can still

  // change it.

  mutable uint32_t m_count;

};

} // namespace ns3

#endif /* SIMPLE_REF_COUNT_H */