/*

* 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 OOM Monitor.

*

*/

#ifndef R_OOMMONITORSESSION_H

#define R_OOMMONITORSESSION_H

#include <e32std.h>

const TInt KOomMaxAllocationWithoutPermission = 1048576;

const TUid KOomMemoryMonitorStatusPropertyCategory = {0x10207218};

const TUint32 KOomMemoryMonitorStatusPropertyKey = 0;

enum TMemoryMonitorStatusPropertyValues

    {

    // Above Treshhold: Free Ram is above good treshhold point and memory monitor isn't freeing any memory

    EAboveTreshHold,

    // Freeing Memory: Memory monitor is in the middle of freeing memory

    EFreeingMemory,

    // Below Treshhold: Memory monitor has tried to free some RAM but total memory is still below treshhold and memory monitor has given up freeing more memory.

    EBelowTreshHold

    };

class ROomMonitorSession : public RSessionBase

    {

public:

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

    enum TOomPriority

        {

        /**

        * Application can be closed if needed.

        */

        EOomPriorityNormal = 0,

        /**

        * Application should not be closed if possible.

        */

        EOomPriorityHigh,

        /**

        * Application is busy and should not be closed.

        */

        EOomPriorityBusy

        };

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();

    /**

    * 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. Other error codes may

    *         also be returned.

    */

    IMPORT_C TInt RequestFreeMemory(TInt aBytesRequested);

    /**

    * @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. Other error codes may

    *        also be set.

    */

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

    /**

    * Request that the OOM 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. Other error codes may

    *         also be returned.

    */

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

    /**

    * Request that the OOM 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 OOM 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 OOM monitor that this application has the specified priority

    * @param aPriority the priority of the application

    */

    IMPORT_C void SetOomPriority(TOomPriority aPriority);

    };

#endif // R_OOMMONITORSESSION_H