--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Symbian3/SDK/Source/GUID-39A8FBC9-5FD6-4F92-B71E-5C5438ECFD46.dita	Wed Mar 31 11:11:55 2010 +0100
@@ -0,0 +1,129 @@
+<?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 concept
+  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="GUID-39A8FBC9-5FD6-4F92-B71E-5C5438ECFD46" xml:lang="en"><title>OOM
+Monitor Overview</title><shortdesc>This section provides an overview of the functionality and the
+architecture of the OOM Monitor component.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
+<section id="GUID-84DFAB24-BC7F-45B2-813D-6CD05EBCF34F-GENID-1-8-1-10-1-1-8-1-5-1-4-1-3-1"><title>Purpose</title><p>The
+OOM Monitor Client API monitors the memory situations and handles out of memory
+situations. OOM monitor is responsible to maintain good memory level in the
+device. In case of low memory situation, OOM Monitor releases memory by closing
+applications based on the priority defined. For information on priority, refer
+to <xref href="GUID-CE308C71-D8B2-43B3-97FD-B868285ED5FB.dita">OOM Monitor Priority</xref>.</p> 
+  </section>
+<section id="GUID-84DFAB24-BC7F-45B2-813D-6CD05EBCF34F-GENID-1-8-1-10-1-1-8-1-5-1-4-1-3-2"><title>Key concepts</title><dl>
+<dlentry>
+<dt>LOW_RAM_THRESHOLD</dt>
+<dd><p>It is the minimum amount of free RAM that is specified for the device.
+This value must be specified in the monitor configuration file. </p> </dd>
+</dlentry>
+<dlentry>
+<dt>GOOD_RAM_THRESHOLD</dt>
+<dd><p>It is the required amount of free RAM that is specified for the device.
+This value must be specified in the monitor configuration file.</p> </dd>
+</dlentry>
+<dlentry>
+<dt>Normal RAM rotation</dt>
+<dd><p>Whenever the amount of free RAM decreases below LOW_RAM_THRESHOLD the
+OOM Monitor releases RAM by closing applications based on the priorities.
+This process is called as normal RAM rotation.</p> </dd>
+</dlentry>
+</dl><p>For information on OOM Monitor Priority and Optional RAM allocation,
+refer to <xref href="GUID-F6A33835-D677-41D0-86BB-812E3AFA5192.dita">OOM Monitor
+Concepts</xref></p>  </section>
+<section id="GUID-84DFAB24-BC7F-45B2-813D-6CD05EBCF34F-GENID-1-8-1-10-1-1-8-1-5-1-4-1-3-3"><title>Architecture</title>  <p>The
+basic function of the OOM Monitor is to monitor the amount of free RAM in
+the mobile device. Whenever the amount of free RAM decreases below a defined <keyword>LOW_RAM_THRESHOLD</keyword> threshold
+value, the OOM Monitor is triggered. The OOM Monitor then releases RAM by
+closing applications running on background in order to raise the amount of
+free RAM above the defined GOOD_RAM_THRESHOLD value.</p><fig id="GUID-1DD9B22F-1060-4AC9-899B-EC2D91E7B948">
+<image href="GUID-F4203C60-EB2A-4644-8B2D-291087724BA9_d0e149615_href.png" placement="inline"/>
+</fig><fig id="GUID-573E838C-50CD-4CE7-B608-6BBD18B29088">
+<image href="GUID-AA820231-5C46-46A1-A310-ABBA45593B1F_d0e149619_href.png" scale="100" placement="inline"/>
+</fig>  </section>
+<section id="GUID-84DFAB24-BC7F-45B2-813D-6CD05EBCF34F-GENID-1-8-1-10-1-1-8-1-5-1-4-1-3-4"><title>APIs</title><p>The
+OOM Monitor Client API consists of <xref href="GUID-02D1911A-D2E5-3D28-9B05-75DA0A75DE73.dita"><apiname>ROomMonitorSession</apiname></xref> class.
+The main functions of this class are:</p><table id="GUID-CF94290C-7BE9-418F-9CF0-93DE74814097-GENID-1-8-1-10-1-1-8-1-5-1-4-1-3-4-3">
+<tgroup cols="2"><colspec colname="col1" colwidth="0.70*"/><colspec colname="col2" colwidth="1.30*"/>
+<tbody>
+<row>
+<entry><p><b>Function</b></p></entry>
+<entry><p><b>Description</b></p></entry>
+</row>
+<row>
+<entry><p><xref href="GUID-1F51447A-B975-3767-8ED9-5E1B98E8A672.dita"><apiname>RequestFreeMemory()</apiname></xref></p></entry>
+<entry><p>Requests the OOM monitor to allocate RAM.</p></entry>
+</row>
+<row>
+<entry><p><xref href="GUID-C8FA6C1A-AE06-3E4D-9884-FAAA93239D13.dita"><apiname>SetOomPriority()</apiname></xref></p></entry>
+<entry><p>Sets the priority for an application as high, busy or normal. The
+application priorities must be defined in <codeph>TOomPriority</codeph> variable.</p></entry>
+</row>
+<row>
+<entry><p><xref href="GUID-2B246C7F-8A7F-3AA7-8150-657A45CF8F57.dita"><apiname>RequestOptionalRam()</apiname></xref></p></entry>
+<entry><p>Requests the OOM monitor to allocate optional RAM.</p></entry>
+</row>
+</tbody>
+</tgroup>
+</table><p>The OOM Monitor Client API also consists of <xref href="GUID-ACE03F26-555A-363E-B220-44FCA7E8EACB.dita"><apiname>COomMonitorPlugin</apiname></xref> class.
+The main functions of this plug-in class are:</p><table id="GUID-CF94290C-7BE9-418F-9CF0-93DE74814097-GENID-1-8-1-10-1-1-8-1-5-1-4-1-3-4-5">
+<tgroup cols="2"><colspec colname="col1" colwidth="0.70*"/><colspec colname="col2" colwidth="1.30*"/>
+<tbody>
+<row>
+<entry><p><b>Function</b></p></entry>
+<entry><p><b>Description</b></p></entry>
+</row>
+<row>
+<entry><p><xref href="GUID-E51E399F-AB9D-3587-9985-5E5016F49587.dita"><apiname>FreeRam()</apiname></xref></p></entry>
+<entry><p>Requests to release RAM when the system RAM level becomes low.</p></entry>
+</row>
+<row>
+<entry><p><xref href="GUID-6D853E56-6EE6-398A-B9BF-BB35C4D5729D.dita"><apiname>MemoryGood()</apiname></xref></p></entry>
+<entry><p>Called when the system RAM level improves to good from low RAM situation.
+Once the memory level is good, the OOM plug-in can again start allocating
+optional RAM.</p></entry>
+</row>
+</tbody>
+</tgroup>
+</table></section>
+<section id="GUID-1D0FDADB-ACAC-4507-BF63-E78A7F322133"><title>Typical Uses</title><p>Applications
+can use the following functionality provided by the OOM Monitor component
+to:  </p><ul>
+<li><p>Safely allocate large amount of RAM. For more information, refer to <xref href="GUID-50CA5439-29A1-426C-83BA-EC048FE86CDE.dita">Requesting for Large Memory
+Allocation</xref>.</p></li>
+<li><p>Change its priority in order to protect itself from being closed by
+the OOM Monitor. For more information, refer to <xref href="GUID-8F8E3814-7ED6-4218-BEEF-741AE0E9366F.dita">Changing
+the Priority</xref>.</p></li>
+<li><p>Allocate optional RAM to applications when additional RAM is requested.
+For more information, refer to <xref href="GUID-217C992B-AC56-42A7-9920-DEC891D233A5.dita">Requesting
+for Optional RAM Allocation</xref>.</p></li>
+<li><p>Prevent OOM errors from happening by monitoring the amount of free
+RAM in the system. When the amount of free RAM drops below the specified threshold
+value, OOM Monitor automatically closes applications that are staying idle
+in the background in order to give more RAM to the applications that are active.
+For more information, refer to <xref href="GUID-0371FD21-D988-4560-891F-2840C36AB2E2.dita">Out
+of Memory Error</xref>.</p></li>
+<li><p>Assign priority for each action that can be used to release RAM (i.e.
+closing an application or calling an OOM plug-in). When releasing RAM, OOM
+Monitor uses the priorities to determine the order of closing applications
+and calling plug-ins. As a result RAM is always released by minimizing the
+negative impact to the user, provided the priorities are correctly configured
+for the device. For more information, refer to <xref href="GUID-178488C1-5453-490F-B168-9D73DB5BAE47.dita">Priority
+Configuration</xref>.</p></li>
+</ul></section>
+<section id="GUID-23F8161E-5057-4ADD-BD2F-BC87F45B4B2E"><title>Related information</title><ul>
+<li><p><xref href="GUID-F6A33835-D677-41D0-86BB-812E3AFA5192.dita">OOM Monitor
+Concepts</xref></p></li>
+<li><p><xref href="GUID-C7AA92A9-9595-439A-A3E7-769E36D61FEE.dita">Using OOM Monitor</xref></p></li>
+<li><p><xref href="GUID-88752800-83BD-4845-80A0-6B65D8D81924.dita">OOM Monitor
+Reference</xref></p></li>
+</ul></section>
+</conbody></concept>
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