/*

* Copyright (c) 2006 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:  COomClientRequestQueue.cpp.

*

*/

#include "oomclientrequestqueue.h"

#include "OomTraces.h"

#include "oomsubscribehelper.h"

#include "oompanic.h"

#include "oommemorymonitor.h"

#include <UikonInternalPSKeys.h>

const TInt KOomWatchDogStatusIdle = -1;

const TInt KClientTimeToFreeMemory = 500000; //microseconds

COomClientRequestQueue::COomClientRequestQueue(CMemoryMonitor& aMonitor)

    :iQueue(_FOFF(TClientRequest,iLink)),

    iMonitor(aMonitor)

    {

    FUNC_LOG;

    }

COomClientRequestQueue::~COomClientRequestQueue()

    {

    FUNC_LOG;

    if (iWatchdogStatusSubscriber)

        {

        iWatchdogStatusSubscriber->StopSubscribe();

        }

    iWatchdogStatusProperty.Close();

    delete iWatchdogStatusSubscriber;

    if (iClientRequestTimer)

        {

        iClientRequestTimer->Cancel();

        }

    delete iClientRequestTimer;

    TClientRequest* request;

    TSglQueIter<TClientRequest> iter(iQueue);

    iter.SetToFirst(); 

    while (iter)

        {

        request = iter++;

        iQueue.Remove(*request);

        delete request;

        };

    }

COomClientRequestQueue* COomClientRequestQueue::NewL(CMemoryMonitor& aMonitor)

    {

    FUNC_LOG;

    COomClientRequestQueue* self = new (ELeave) COomClientRequestQueue(aMonitor);

    CleanupStack::PushL(self);

    self->ConstructL();

    CleanupStack::Pop(self); 

    return self;

    }

void COomClientRequestQueue::ConstructL()

    {

    FUNC_LOG;

    TInt err = iWatchdogStatusProperty.Attach(KPSUidUikon, KUikOOMWatchdogStatus);

    TRACES1("COomClientRequestQueue::ConstructL: KUikOOMWatchdogStatus err = %d", err);

    err = iWatchdogStatusProperty.Set(KOomWatchDogStatusIdle);

    iWatchdogStatusSubscriber = new (ELeave) CSubscribeHelper(TCallBack(WatchdogStatusStatusChanged, this), iWatchdogStatusProperty);

    iWatchdogStatusSubscriber->Subscribe();

    iClientRequestTimer = COomClientRequestTimer::NewL(*this);    

    }

void COomClientRequestQueue::RequestFreeMemoryL(const RMessage2& aMessage)

    {

    FUNC_LOG;

    TClientRequest* request = new (ELeave) TClientRequest(EClientServerRequestFreeMemory, aMessage);

    CleanupStack::PushL(request);

    AddClientRequestL(*request);

    CleanupStack::Pop(request);

    }

void COomClientRequestQueue::RequestOptionalRamL(const RMessage2& aMessage)

    {

    FUNC_LOG;

    TClientRequest* request = new (ELeave) TClientRequest(EClientServerRequestOptionalRam, aMessage);

    CleanupStack::PushL(request);

    AddClientRequestL(*request);

    CleanupStack::Pop(request);

    }

TInt COomClientRequestQueue::WatchdogStatusStatusChanged(TAny* aPtr)

    {

    FUNC_LOG;

    COomClientRequestQueue* self = static_cast<COomClientRequestQueue*>(aPtr);

    if (self)

        {

        self->HandleWatchdogStatusCallBack();

        }

    return KErrNone;

    }

void COomClientRequestQueue::HandleWatchdogStatusCallBack()

    {

    FUNC_LOG;

    // Someone has set the key to request some free memory.

    TInt memoryRequested = 0;

    iWatchdogStatusProperty.Get(memoryRequested);

    // Try to free the RAM.

    if (memoryRequested >= 1)

        {

        TClientRequest request = TClientRequest(EPublishAndSubscribe, memoryRequested);

        TRAP_IGNORE(AddClientRequestL(request));

        }

    // Set the key back to KOomWatchDogStatusIdle to indicate we're done.

    iWatchdogStatusProperty.Set(KOomWatchDogStatusIdle);

    }

// The new request is added to the queue, then we have the following conditions: 

// 1. A client request is currently being processed

// 2. The last client request completed less than KClientTimeToFreeMemory microseconds ago -> start the timer

// 3. The timer has already been started

// 4. none of the above -> process this request

void COomClientRequestQueue::AddClientRequestL(TClientRequest& request)

    {

    FUNC_LOG;

    iQueue.AddLast(request);

    if ( !iClientRequestActive && !iClientRequestTimer->IsActive() )

        {

        TTime now;

        now.UniversalTime();

        TInt64 interval64 = (now.MicroSecondsFrom(iLastClientCompletedTime)).Int64();

        TRACES3("COomClientRequestQueue::AddClientRequestL: now = %Ld, iLastClientCompletedTime = %Ld, interval64 = %Ld",

                now.Int64(), iLastClientCompletedTime.Int64(), interval64);

        if ( interval64 < 0)        

            {

            //If the system time is moved backwards we lose the information about when the last request was 

            //made, so we wait for KClientTimeToFreeMemory microseconds

            iClientRequestTimer->After(TTimeIntervalMicroSeconds32(KClientTimeToFreeMemory));            

            }

        else if ( interval64 < KClientTimeToFreeMemory)

            {            

            //The last completed client is given KClientTimeToFreeMemory microseconds to allocate the memory 

            //it requested

            iClientRequestTimer->After(TTimeIntervalMicroSeconds32(interval64));

            }

        else 

            {

            StartClientRequestL();

            }        

        }

    }

void COomClientRequestQueue::StartClientRequestL()

    {    

    FUNC_LOG;

    iClientRequestActive = ETrue;

    TClientRequest* request = iQueue.First();

    switch (request->iClientRequestType)

        {

        case EClientServerRequestOptionalRam:

            {

            TInt pluginId = request->iRequestFreeRamMessage.Int2();

            iMonitor.FreeOptionalRamL(request->iBytesRequested, pluginId);

            break;

            }

        case EClientServerRequestFreeMemory:

            iMonitor.RequestFreeMemoryL(request->iBytesRequested);

            break;

        case EPublishAndSubscribe:

            iMonitor.RequestFreeMemoryPandSL(request->iBytesRequested);

            break;

        default:

            OomMonitorPanic(KInvalidClientRequestType);

            break;

        }

    }

CMemoryMonitor& COomClientRequestQueue::Monitor()

    {

    FUNC_LOG;

    return iMonitor;

    }

TClientRequest::TClientRequest(TActionTriggerType aClientRequestType, TInt aBytesRequested)    

    : iClientRequestType(aClientRequestType), iBytesRequested(aBytesRequested)   

    {

    FUNC_LOG;

    }

TClientRequest::TClientRequest(TActionTriggerType aClientRequestType, const RMessage2& aRequestFreeRam)    

    : iClientRequestType(aClientRequestType), iRequestFreeRamMessage(aRequestFreeRam)

    {

    FUNC_LOG;

    iBytesRequested = aRequestFreeRam.Int0();

    }

void COomClientRequestQueue::ActionsCompleted(TInt aBytesFree, TBool aMemoryGood)

    {

    FUNC_LOG;

    if (iClientRequestActive)

        {

#ifdef _DEBUG

        TSglQueIter<TClientRequest> iter(iQueue);

        iter.SetToFirst();

        TClientRequest* req;

        while (iter)

            {

            req = iter++;

            TActionTriggerType crt = req->iClientRequestType;

            TInt bytes = req->iBytesRequested;

            TRACES2("COomClientRequestQueue::ActionsCompleted Printing Queue: Type = %d, Bytes Requested = %d", crt, bytes);

            };

#endif 

        __ASSERT_DEBUG(!iQueue.IsEmpty(), OomMonitorPanic(KClientQueueNotEmpty));        

        __ASSERT_DEBUG(!iClientRequestTimer->IsActive(), OomMonitorPanic(KClientRequestTimerActive));        

        TClientRequest* request = iQueue.First();

        RMessage2 message;

        switch (request->iClientRequestType)

            {

            case EClientServerRequestOptionalRam:

                message = request->iRequestFreeRamMessage;

                if (!message.IsNull())

                    {

                    TInt memoryAvailable = aBytesFree - iMonitor.GoodThreshold();

                    TInt minimumNeeded = message.Int1();

                    if (memoryAvailable >= minimumNeeded)

                        {

                        message.Complete(memoryAvailable);

                        }

                    else

                        {

                        message.Complete(KErrNoMemory);

                        }

                    }

                break;

            case EClientServerRequestFreeMemory:

                message = request->iRequestFreeRamMessage;

                if (!message.IsNull())

                    {

                    // If memory available is greater than the requested RAM then complete with the amount of free memory, otherwise complete with KErrNoMemory

                    message.Complete(aMemoryGood ? KErrNone : KErrNoMemory);        

                    }

                break;

            case EPublishAndSubscribe:

                // No action required for P&S key

                break; 

            default:

                OomMonitorPanic(KInvalidClientRequestType);

                break;

            }

        iClientRequestActive = EFalse;

        iQueue.Remove(*request);

        delete request;

        iLastClientCompletedTime.UniversalTime();

        if (!iQueue.IsEmpty())

            {

            //We give the client KClientTimeToFreeMemory microseconds to free the memory it requested before 

            //processing the next request

            iClientRequestTimer->After(TTimeIntervalMicroSeconds32(KClientTimeToFreeMemory));

            }

        }    

    }

void COomClientRequestQueue::RequestTimerCallbackL()

    {

    FUNC_LOG;

    __ASSERT_DEBUG(!iQueue.IsEmpty(), OomMonitorPanic(KClientQueueNotEmpty));        

    StartClientRequestL();

    }

COomClientRequestTimer* COomClientRequestTimer::NewL(COomClientRequestQueue& aQueue)

    {

    FUNC_LOG;

    COomClientRequestTimer* self = new (ELeave) COomClientRequestTimer(aQueue);

    CleanupStack::PushL(self);

    self->ConstructL();

    CleanupStack::Pop(self);

    return self;

    }

COomClientRequestTimer::COomClientRequestTimer(COomClientRequestQueue& aQueue)

: CTimer(CActive::EPriorityStandard), iClientRequestQueue(aQueue)

    {

    FUNC_LOG;

    CActiveScheduler::Add(this);

    }

void COomClientRequestTimer::RunL()

    {

    FUNC_LOG;

    iClientRequestQueue.RequestTimerCallbackL();

    }