<?xml version="1.0" encoding="utf-8"?>

<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

<!-- This component and the accompanying materials are made available under the terms of the License 

"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: 

-->

<!DOCTYPE task

  PUBLIC "-//OASIS//DTD DITA Task//EN" "task.dtd">

<task id="GUID-C4C8395E-F982-4D6A-88D3-28EDC494817F" xml:lang="en"><title>Requesting

RAM Asynchronously</title><shortdesc>This section describes how an application can request for free

RAM asynchronously.</shortdesc><prolog><metadata><keywords/></metadata></prolog><taskbody>

<prereq id="GUID-6C258B11-CE78-42F2-828D-E9C68598C193"><p>Perform the steps

described in <xref href="GUID-50CA5439-29A1-426C-83BA-EC048FE86CDE.dita">Allowing

Large Memory Allocation</xref>.</p></prereq>

<context id="GUID-D36C0590-A436-458B-B7A6-F2E8577E26C6">       <p>Requesting

free RAM asynchronously is recommended as the application is not blocked during

the method call handling.</p>     </context>

request for a block of memory.</cmd>

<info><codeblock xml:space="preserve">CMemoryAllocatingObject::StartFunctionalityRequiringAllocationL()

    {

    User::LeaveIfError(iOomMonitorSession.Connect());

    iMemoryRequester = CMemoryRequester::NewL(iOomMonitorSession, *this);

    iMemoryRequester->Start(KLargeValueToAllocate);

    }

</codeblock></info>

</step>

object and request for free memory.</cmd>

<info><codeblock xml:space="preserve">void CMemoryRequester::Start(TInt aBytesRequested)

    {

    iOomMonitorSession.RequestFreeMemory(aBytesRequested, iStatus);    

    SetActive();

    }

</codeblock></info>

</step>

</steps>

<example><p>The following code snippet illustrates an asynchronous request

for free RAM allocation: </p><codeblock xml:space="preserve">const TInt KLargeValueToAllocate = 2097152; //2MB

// Start an asynchronous request for block of memory

CMemoryAllocatingObject::StartFunctionalityRequiringAllocationL()

    {

    User::LeaveIfError(iOomMonitorSession.Connect());

    iMemoryRequester = CMemoryRequester::NewL(iOomMonitorSession, *this);

    iMemoryRequester->Start(KLargeValueToAllocate);

    }

// Called when the asynchronous request is completed

CMemoryAllocatingObject::MemoryRequestCompleteL(TInt aResult)

    {

    if (aResult == KErrNone)

        {

        DoFunctionRequiring_KLargeValueToAllocate_BytesL();

        }

    iOomMonitorSession.Close();

    }

The active object implementation is the following:

// Start an asynchronous request for block of memory

void CMemoryRequester::Start(TInt aBytesRequested)

    {

    iOomMonitorSession.RequestFreeMemory(aBytesRequested, iStatus);    

    SetActive();

    }

// Called when the asynchronous request is completed

void CMemoryRequester::RunL()

    {

    iObserver.MemoryRequestCompleteL(iStatus.Int());

    }

</codeblock></example>

</taskbody><related-links>

<link href="GUID-CE308C71-D8B2-43B3-97FD-B868285ED5FB.dita"><linktext>OOM Monitor

Priority</linktext></link>

<link href="GUID-39A8FBC9-5FD6-4F92-B71E-5C5438ECFD46.dita"><linktext>OOM Monitor

Overview</linktext></link>

<link href="GUID-88752800-83BD-4845-80A0-6B65D8D81924.dita"><linktext>OOM Monitor

Reference</linktext></link>

</related-links></task>