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     7     Nokia Corporation - initial contribution.

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    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept id="GUID-1D6DD213-1EEC-58D2-8311-7A1AF77960C1" xml:lang="en"><title>How

    13 to issue requests</title><shortdesc>This document describes how an active object issues a request for

    14 a service.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    15 <p>Once the active object has been constructed, a request can be issued. In

    16 the following code fragment, the active object provides the function <codeph>IssueRequest()</codeph> to

    17 invoke the encapsulated service function.</p>

    18 <codeblock id="GUID-9C89E661-AD2E-520A-8E8D-F6D4E667706A" xml:space="preserve">void CExampleActiveObject::IssueRequest()

    19     {

    20         // Request the service

    21     iServiceProvider-> RequestTheService(iStatus);

    22         // Indicate request has been issued

    23     SetActive();

    24     }</codeblock>

    25 <ul>

    26 <li id="GUID-8359DED4-C349-51AF-8771-111716DC49B3"><p>Pass the <codeph>TRequestStatus</codeph> object,

    27 provided by the active objects's <codeph>CActive</codeph> base class, to the

    28 service function. As part of its processing, the service function sets this

    29 to <codeph>KRequestPending</codeph>, indicating that the request has been

    30 issued but is not yet complete.</p> </li>

    31 <li id="GUID-E3652D72-749D-577D-8ED3-9FCEDCB2CCA9"><p>Set the base class's

    32 active request flag, using the function <codeph>SetActive()</codeph>, to indicate

    33 that the active object is currently active. The flag is reset by the active

    34 scheduler before handling a completed request, or by the active object base

    35 class as part of the cancellation protocol.</p> </li>

    36 </ul>

    37 <section id="GUID-213A1B18-AD81-478A-BC14-F8030F9AF095"><title>Completing a request</title> <p>At some point, the service

    38 provider's processing completes and it calls <codeph>RThread::RequestComplete()</codeph> passing

    39 the request status object and the service provider's return code, a value

    40 other than <codeph>KRequestPending</codeph>. This results in the active object's <codeph>iStatus</codeph> member

    41 being set to the return code value and a signal that the request is complete.</p> </section>

    42 </conbody></concept>