/****************************************************************************
**
** https://www.qxorm.com/
** Copyright (C) 2013 XDL Team (ic-east.com)
**
** This file is part of the QxOrm library
**
** This software is provided 'as-is', without any express or implied
** warranty. In no event will the authors be held liable for any
** damages arising from the use of this software
**
** Commercial Usage
** Licensees holding valid commercial QxOrm licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and XDL Team
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file 'license.gpl3.txt' included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met : http://www.gnu.org/copyleft/gpl.html
**
** If you are unsure which license is appropriate for your use, or
** if you have questions regarding the use of this file, please contact :
** ic-east.com
**
****************************************************************************/

#ifndef _QX_SINGLETON_H_
#define _QX_SINGLETON_H_

#ifdef _MSC_VER
#pragma once
#endif

/*!
 * \file QxSingleton.h
 * \author XDL Team
 * \ingroup QxSingleton
 * \brief Concrete class to define a thread-safe singleton of QxOrm library
 */

#include <QtCore/qmutex.h>
#include <QtCore/qcoreapplication.h>

#include <QxSingleton/IxSingleton.h>

namespace qx
{

   /*!
    * \ingroup QxSingleton
    * \brief qx::QxSingleton<T> : concrete class to define a thread-safe singleton of type T
    */
   template <class T>
   class QxSingleton : public IxSingleton
   {

   private:
      static T *m_pSingleton;          //!< Singleton -> only 1 instance allowed
      static QMutex m_oMutexSingleton; //!< Mutex -> 'QxSingleton' is thread-safe

   protected:
      QxSingleton(const QString &sKey) : IxSingleton(sKey) { ; }
      virtual ~QxSingleton() { ; }

   public:
      static T *getSingleton();
      static void deleteSingleton();

   protected:
      static bool isSingletonNull() { return (m_pSingleton == NULL); }

      virtual void deleteInstance() { QxSingleton<T>::deleteSingleton(); }
   };

} // namespace qx

#include "../../inl/QxSingleton/QxSingleton.inl"

#endif // _QX_SINGLETON_H_
