1 /*

     2 * Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

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

     6 * which accompanies this distribution, and is available

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

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:   The global lock class for messaging components

    15 *

    16 */

    17 

    18 

    19 

    20 #ifndef MUIULOCK_H

    21 #define MUIULOCK_H

    22 

    23 class CRepository;

    24 

    25 #include "MessagingInternalCRKeys.h"

    26 

    27 

    28 // Lock identifier for messaging settings access

    29 //

    30 const TUid KMuiuLockSettings = { KCRUidMuiuVariationValue };

    31 

    32 /**

    33  *  The global lock class for messaging components

    34  *

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

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

    37  *  used for synchronisation between the processes.

    38  *

    39  *  The current implementation is based on the transaction mechanism of

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

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

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

    43  *

    44  *  @lib muiu_internal.lib

    45  *  @since S60 5.0

    46  */

    47 NONSHARABLE_CLASS( CMuiuLock ) : public CBase

    48     {

    49 public:

    50     /**

    51      * Creates a new instance of the class

    52      *

    53      * @since S60 5.0

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

    55      *                   of the existing central repository file that can be reserved

    56      *                   for a write transaction while the lock is used.

    57      * @return           New instance of the class

    58      */

    59      IMPORT_C static CMuiuLock* NewL( TUid aLockId );

    60 

    61     /**

    62      * Destructor. Releases the lock if not done explicitly.

    63      */

    64     virtual ~CMuiuLock();

    65 

    66     /**

    67      * Reserves the lock for the client.

    68      *

    69      * @since S60 5.0

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

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

    72      *                   services forwarded as such.

    73      */

    74     IMPORT_C TInt Reserve();

    75 

    76     /**

    77      * Releases the lock

    78      *

    79      * @since S60 5.0

    80      */

    81     IMPORT_C void Release();

    82 

    83 private:

    84     /**

    85      * Default constructor

    86      *

    87      * @since S60 5.0

    88      */

    89     CMuiuLock();

    90     

    91     /**

    92      *  Second phase constructor

    93      *

    94      * @since S60 5.0

    95      * @param aLockId    See description of NewL() method

    96      */

    97     void ConstructL( TUid aLockId );

    98 private: // data

    99     /**

   100      * Central repository handle

   101      */

   102     CRepository* iRepository;

   103 

   104     /**

   105      * State flag indicating whether the lock is reserved or not

   106      */

   107     TBool iLocked;

   108     };

   109 

   110 #endif // MUIULOCK_H