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1 <?xml version="1.0" encoding="utf-8"?> |
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2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
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3 <!-- This component and the accompanying materials are made available under the terms of the License |
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4 "Eclipse Public License v1.0" which accompanies this distribution, |
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5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
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6 <!-- Initial Contributors: |
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7 Nokia Corporation - initial contribution. |
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8 Contributors: |
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9 --> |
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10 <!DOCTYPE concept |
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11 PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
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12 <concept id="GUID-316ED912-04F7-5613-942E-516C3AB01C49" xml:lang="en"><title>Domain</title><shortdesc>A domain is associated with one or more applications, typically |
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13 the applications that take part in, or are associated with those activities. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody> |
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14 <p>Domains classify applications by their power requirements and dependencies. |
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15 A domain is defined as a type of activity, or a class of system services, |
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16 for example, telephony, networking, or camera. The exact definition depends |
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17 on the device. </p> |
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18 <p>A domain is associated with one or more applications, typically the applications |
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19 that take part in, or are associated with those activities. Applications register |
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20 with a domain, and are then said to belong to that domain. Domain population |
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21 by applications is a dynamic process, as applications can also leave a domain. </p> |
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22 <p>A domain has a power state, i.e. <i>Active</i>, <i>Standby</i> or <i>Off</i>. |
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23 The power state is updated by the domain manager through the publish & |
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24 subscribe mechanism. After registration with a domain, applications typically |
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25 maintain an outstanding request to be notified of changes to the domain's |
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26 power state. </p> |
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27 <p>Domains form a tree structure, with parent-child relationships. The architecture |
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28 permits power transitions to apply to specified domains either as a result |
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29 of user action, or by individual application request, or by the device's power |
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30 management policy. The domain tree defines the order in which power transitions |
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31 occur. </p> |
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32 <p>For transitions to the <i>Off</i> or <i>Standby</i> state, all applications |
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33 within a domain are notified of the transition; the transition is considered |
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34 complete for a domain when all of its applications have acknowledged the transition |
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35 (and completed whatever action they deem necessary to save their state). Notification |
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36 proceeds from child domains up to the parent domain. A domain transition can |
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37 only start when all of its child domains have successfully completed their |
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38 power state transition. </p> |
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39 <p>For transitions to the <i>Active</i> state, notification happens in the |
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40 reverse order, starting with the parent domains and proceeding down the tree |
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41 to the child domains. </p> |
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42 <fig id="GUID-90A60E81-1461-5CF7-9BA5-94AFAE96635D"> |
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43 <image href="GUID-4710494E-835F-50B8-B0B5-0482147C02D2_d0e363420_href.png" placement="inline"/> |
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44 </fig> |
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45 <p>Domains are identified by a domain Id. This is an 8-bit wide number and |
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46 is defined as being of type <xref href="GUID-4F284AB0-85A5-3871-B973-8BCAB4AA91BC.dita"><apiname>TDmDomainId</apiname></xref>. The Symbian platform |
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47 defines two generic domain Ids: <xref href="GUID-766E2EA6-AB0C-3631-AC82-AA0B98E5D4BE.dita"><apiname>KDmIdApps</apiname></xref> and <xref href="GUID-1D54EF94-5744-350D-87B6-5EE87BDD17E5.dita"><apiname>KDmIdUiApps</apiname></xref> in <filepath>domaindefs.h</filepath>. |
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48 However, the <xref href="GUID-1197F032-1B73-58E1-8B45-E5D58B9DF788.dita">Domain |
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49 Management Policy DLL</xref> can define additional policy-specific domain |
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50 identifiers. </p> |
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51 </conbody></concept> |