/*

* Copyright (c) 2006-2009 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:  Client/server interface for GOOM Monitor.

*

*/

#ifndef R_GOOMMONITORSESSION_H

#define R_GOOMMONITORSESSION_H

#include <e32std.h>

/**

 *  The maximum amount of memory that can be allocated without permission.

 */

const TInt KGOomMaxAllocationWithoutPermission = 1048576;

/**

 *  The client interface for GOOM (Out Of Memory) monitor.

 *

 *  @lib oommonitor.lib

 */

class RGOomMonitorSession : public RSessionBase

    {

public:

    /**  Defines the application priorities of GOOM monitor. */

    enum TGOomPriority

        {

        /**

        * Application can be closed if needed.

        */

        EGOomPriorityNormal = 0,

        /**

        * Application should not be closed if possible.

        */

        EGOomPriorityHigh,

        /**

        * Application is busy and should not be closed.

        */

        EGOomPriorityBusy

        };

public:

    /**

    * Connects a new session.

    * Sessions must be connected before any other APIs can be used.

    * When the client has finished using a session, Close() must be called.

    * @return KErrNone if successful, error code otherwise.

    */

    IMPORT_C TInt Connect();

    /**

    * Tells whether Goom FW is really present and connected

    * In some platforms, there's no need for GOOM to run

    * and all operations do just nothing 

    */

    IMPORT_C TBool IsConnected();

    /**

    * Request that the GOOM monitor attempts to free some memory.

    * This function may take several seconds to execute, depending on

    * the memory state. It will not return until the attempt to recover

    * memory has completed.

    * @param aBytesRequested The number of bytes of free memory that the client requests.

    * @return KErrNone if the request memory is free. KErrNoMemory if that

    *         amount of memory could not be recovered.

    */

    IMPORT_C TInt RequestFreeMemory(TInt aBytesRequested);

    /**

    * Request that the GOOM monitor attempts to free some memory.

    * This is an asynchronous version of the request for free memory.

    * @param aBytesRequested The number of bytes of free memory that the client requests.

    * @param aStatus will be completed when the attempt to recover memory

    *        has finished. This may take several seconds, depending on

    *        the memory state. On completion, aStatus will be set to

    *        KErrNone if the request memory is free. KErrNoMemory if that

    *        amount of memory could not be recovered.

    */

    IMPORT_C void RequestFreeMemory(TInt aBytesRequested, TRequestStatus& aStatus);

    /**

    * Request that the GOOM monitor attempts to free some memory for an optional allocation.

    * The passed in plugin ID is used to determine the priority for this allocation.

    * Lower priority OOM actions may be executed to free enough RAM for this allocation.

    * This function may take several seconds to execute, depending on

    * the memory state. It will not return until the attempt to recover

    * memory has completed.

    * @param aBytesRequested The number of bytes of free memory that the client requests.

    * @param aPluginId The ID of the plugin that may delete the allocation in event of low memory.

    * @return KErrNone if the request memory is free. KErrNoMemory if that

    *         amount of memory could not be recovered.  

    */

    IMPORT_C TInt RequestOptionalRam(TInt aBytesRequested, TInt aMinimumBytesNeeded, TInt aPluginId, TInt& aBytesAvailable);

    /**

    * Request that the GOOM monitor attempts to free some memory for an optional allocation.

    * The passed in plugin ID is used to determine the priority for this allocation.

    * Lower priority OOM actions may be executed to free enough RAM for this allocation.

    * This function may take several seconds to execute, depending on

    * the memory state. It will not return until the attempt to recover

    * memory has completed.

    * @param aBytesRequested The number of bytes of free memory that the client requests.

    * @param aPluginId The ID of the plugin that may delete the allocation in event of low memory.

    * @param aStatus The TRequestStatus (completes with the number of bytes freed (aStatus >= 0) or an error (aStatus <= 0))

    * @return None

    */

    IMPORT_C void RequestOptionalRam(TInt aBytesRequested, TInt aMinimumBytesNeeded, TInt aPluginId, TRequestStatus& aStatus);

    /**

    * Cancels the asynchronous request for free memory.

    */

    IMPORT_C void CancelRequestFreeMemory();

    /**

    * Notify the GOOM monitor that this application is not responding

    * to the EEikCmdExit request to exit the application.

    * This function is used by the Avkon framework's app shutter.

    * @param aWgId the window group identifier of the app that is not exiting.

    */

    IMPORT_C void ThisAppIsNotExiting(TInt aWgId);

    /**

    * Notify the GOOM monitor that this application has the specified priority

    * @param aPriority the priority of the application

    */

    IMPORT_C void SetGOomPriority(TGOomPriority aPriority);

    /**

    * Notify the GOOM monitor that this application about to laucnh

    * effectively set the application specific threshold if found from 

    * config file

    * @param aAppUid the identifier of the application

    */

    IMPORT_C void ApplicationAboutToStart(const TUid& aAppUid);

    /**

    * Tell goom that number requested by application should be used as such

    * and not combined with currently active global threshold

    * @param aUseAbsoluteAmount whtether global thresholds are combined with targets

    */

    IMPORT_C void UsesAbsoluteMemTargets(TBool aUseAbsoluteAmount = ETrue);

    /**

    * Asynchronous version of Connect.

    * @param aStatus request status, completed later only 

    *        if return value equals to KErrNone.

    * @return error code, KErrNone if connection started.

    */

    IMPORT_C TInt Connect(TRequestStatus& aStatus);

    /**

    * Asynchronous version of AppAboutToStart.

    * @param aStatus request status.

    * @param aAppUid application UID being started.

    */

    IMPORT_C void AppAboutToStart(TRequestStatus& aStatus, const TUid& aAppUid);

private://data 

    TInt iFlags;

    };

#endif // R_GOOMMONITORSESSION_H