/*

* Copyright (c) 2007 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:   The global lock class for messaging components

*

*/

#ifndef MUIULOCK_H

#define MUIULOCK_H

class CRepository;

#include "messaginginternalcrkeys.h"

// Lock identifier for messaging settings access

//

const TUid KMuiuLockSettings = { KCRUidMuiuVariationValue };

/**

 *  The global lock class for messaging components

 *

 *  The service can be used for creating runtime "locks" for protecting

 *  the shared resources over the process boundaries; i.e.the locks can be 

 *  used for synchronisation between the processes.

 *

 *  The current implementation is based on the transaction mechanism of

 *  Central Repository. The lock ID is the identifier of the repository

 *  file. The "lock" is created by opening a write transaction to the

 *  repository. Thus, the repository cannot be modified while the lock is on.

 *

 *  @lib muiu_internal.lib

 *  @since S60 5.0

 */

NONSHARABLE_CLASS( CMuiuLock ) : public CBase

    {

public:

    /**

     * Creates a new instance of the class

     *

     * @since S60 5.0

     * @param aLockId    The lock identifier. Currently, this has to be the ID

     *                   of the existing central repository file that can be reserved

     *                   for a write transaction while the lock is used.

     * @return           New instance of the class

     */

     IMPORT_C static CMuiuLock* NewL( TUid aLockId );

    /**

     * Destructor. Releases the lock if not done explicitly.

     */

    virtual ~CMuiuLock();

    /**

     * Reserves the lock for the client.

     *

     * @since S60 5.0

     * @return           Operation status. KErrNone if successful. KErrGeneral, if the lock

     *                   is already reserved by the client. The error codes of the underlying

     *                   services forwarded as such.

     */

    IMPORT_C TInt Reserve();

    /**

     * Releases the lock

     *

     * @since S60 5.0

     */

    IMPORT_C void Release();

private:

    /**

     * Default constructor

     *

     * @since S60 5.0

     */

    CMuiuLock();

    /**

     *  Second phase constructor

     *

     * @since S60 5.0

     * @param aLockId    See description of NewL() method

     */

    void ConstructL( TUid aLockId );

private: // data

    /**

     * Central repository handle

     */

    CRepository* iRepository;

    /**

     * State flag indicating whether the lock is reserved or not

     */

    TBool iLocked;

    };

#endif // MUIULOCK_H