/*

* Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:   TLS store for singleton objects

*

*/

#ifndef __C_GLXSINGLETONSTORE_H__

#define __C_GLXSINGLETONSTORE_H__

#include <e32base.h>

/**

 *  CGlxSingletonStore

 *

 *  Store for singleton objects

 * 

 *  Usage:

 *

 *  Singleton class must be derived from CBase (either

 *  directly or via base class). Otherwise, singleton's destructor

 *  is not called correctly.

 *

 *  class CMyClass : public CBase ...

 *      {

 *  public:

 *      static CMyClass* InstanceL() 

 *          {

 *          // Pass in the factory function

 *          return CGlxSingletonStore::InstanceL(&NewL);

 *          }

 *

 *      void Close() 

 *          {

 *          CGlxSingletonStore::Close(this);

 *          }

 *

 *  private:

 *      static CMyClass* NewL() 

 *          {

 *          ...

 *          }

 *      };

 *

 */

NONSHARABLE_CLASS(CGlxSingletonStore) : public CBase

    {

public:

    /** 

     * Return a singleton instance and add to reference count

     */ 

    template <class T>

    static T* InstanceL(T* (*aFactoryFuncL)());

    /** 

     * Decrement reference count of singleton instance 

     * and delete if last reference removed

     */ 

    IMPORT_C static void Close(CBase* aInstance);

    /** Destructor */ 

    IMPORT_C ~CGlxSingletonStore();

private:

    /** Constructor */ 

    CGlxSingletonStore();

    /** 

     * Two-phase constructor

     * Creates an instance if one does not already exist

     * Exported for accessing from inline function

     */

    IMPORT_C static CGlxSingletonStore* InstanceLC();

    /** Cleanup function for Cleanup Stack */

    static void Cleanup(TAny* aSingletonStore);        

private:

    /** Struct to store a singleton an its ref count */

	class TSingleton

	    {

	public:

	    CBase* iObject;

	    TInt iReferenceCount;	    

	    };

	/** Array of singletons */

	RArray<TSingleton> iSingletons;

    };

#include "glxsingletonstore.inl"

#endif // __C_GLXSINGLETONSTORE_H__