<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Resolver service requirements</title> <link rel="stylesheet" href="../../boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.73.2"> <link rel="start" href="../../index.html" title="Asio"> <link rel="up" href="../reference.html" title="Reference"> <link rel="prev" href="ResolveHandler.html" title="Resolve handler requirements"> <link rel="next" href="SerialPortService.html" title="Serial port service requirements"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr><td valign="top"><img alt="asio C++ library" width="250" height="60" src="../../asio.png"></td></tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="ResolveHandler.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../home.png" alt="Home"></a><a accesskey="n" href="SerialPortService.html"><img src="../../next.png" alt="Next"></a> </div> <div class="section" lang="en"> <div class="titlepage"><div><div><h3 class="title"> <a name="asio.reference.ResolverService"></a><a class="link" href="ResolverService.html" title="Resolver service requirements"> Resolver service requirements</a> </h3></div></div></div> <p> A resolver service must meet the requirements for an <a class="link" href="IoObjectService.html" title="I/O object service requirements">I/O object service</a>, as well as the additional requirements listed below. </p> <p> In the table below, <code class="computeroutput"><span class="identifier">X</span></code> denotes a resolver service class for protocol <code class="computeroutput"><span class="identifier">InternetProtocol</span></code>, <code class="computeroutput"><span class="identifier">a</span></code> denotes a value of type <code class="computeroutput"><span class="identifier">X</span></code>, <code class="computeroutput"><span class="identifier">b</span></code> denotes a value of type <code class="computeroutput"><span class="identifier">X</span><span class="special">::</span><span class="identifier">implementation_type</span></code>, <code class="computeroutput"><span class="identifier">q</span></code> denotes a value of type <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_resolver_query</span><span class="special"><</span><span class="identifier">InternetProtocol</span><span class="special">></span></code>, <code class="computeroutput"><span class="identifier">e</span></code> denotes a value of type <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_endpoint</span><span class="special"><</span><span class="identifier">InternetProtocol</span><span class="special">></span></code>, <code class="computeroutput"><span class="identifier">ec</span></code> denotes a value of type <code class="computeroutput"><span class="identifier">error_code</span></code>, and <code class="computeroutput"><span class="identifier">h</span></code> denotes a value meeting <a class="link" href="ResolveHandler.html" title="Resolve handler requirements"><code class="computeroutput"><span class="identifier">ResolveHandler</span></code></a> requirements. </p> <div class="table"> <a name="id554817"></a><p class="title"><b>Table 22. ResolverService requirements</b></p> <div class="table-contents"><table class="table" summary="ResolverService requirements"> <colgroup> <col> <col> <col> </colgroup> <thead><tr> <th> <p> expression </p> </th> <th> <p> return type </p> </th> <th> <p> assertion/note<br> pre/post-condition </p> </th> </tr></thead> <tbody> <tr> <td> <p> <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">destroy</span><span class="special">(</span><span class="identifier">b</span><span class="special">);</span></code> </p> </td> <td> <p> </p> </td> <td> <p> From <a class="link" href="IoObjectService.html" title="I/O object service requirements">IoObjectService</a> requirements. Implicitly cancels asynchronous resolve operations, as if by calling <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">cancel</span><span class="special">(</span><span class="identifier">b</span><span class="special">,</span> <span class="identifier">ec</span><span class="special">)</span></code>. </p> </td> </tr> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">a</span><span class="special">.</span><span class="identifier">cancel</span><span class="special">(</span><span class="identifier">b</span><span class="special">,</span> <span class="identifier">ec</span><span class="special">);</span> </pre> <p> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">error_code</span></code> </p> </td> <td> <p> Causes any outstanding asynchronous resolve operations to complete as soon as possible. Handlers for cancelled operations shall be passed the error code <code class="computeroutput"><span class="identifier">error</span><span class="special">::</span><span class="identifier">operation_aborted</span></code>. </p> </td> </tr> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">a</span><span class="special">.</span><span class="identifier">resolve</span><span class="special">(</span><span class="identifier">b</span><span class="special">,</span> <span class="identifier">q</span><span class="special">,</span> <span class="identifier">ec</span><span class="special">);</span> </pre> <p> </p> </td> <td> <p> </p> <pre class="programlisting"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_resolver_iterator</span><span class="special"><</span> <span class="identifier">InternetProtocol</span><span class="special">></span> </pre> <p> </p> </td> <td> <p> On success, returns an iterator <code class="computeroutput"><span class="identifier">i</span></code> such that <code class="computeroutput"><span class="identifier">i</span> <span class="special">!=</span> <span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_resolver_iterator</span><span class="special"><</span><span class="identifier">InternetProtocol</span><span class="special">>()</span></code>. Otherwise returns <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_resolver_iterator</span><span class="special"><</span><span class="identifier">InternetProtocol</span><span class="special">>()</span></code>. </p> </td> </tr> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">a</span><span class="special">.</span><span class="identifier">async_resolve</span><span class="special">(</span><span class="identifier">b</span><span class="special">,</span> <span class="identifier">q</span><span class="special">,</span> <span class="identifier">h</span><span class="special">);</span> </pre> <p> </p> </td> <td> <p> </p> </td> <td> <p> Initiates an asynchronous resolve operation that is performed via the <code class="computeroutput"><span class="identifier">io_service</span></code> object <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">io_service</span><span class="special">()</span></code> and behaves according to <a class="link" href="asynchronous_operations.html" title="Requirements on asynchronous operations">asynchronous operation</a> requirements.<br> <br> If the operation completes successfully, the <code class="computeroutput"><span class="identifier">ResolveHandler</span></code> object <code class="computeroutput"><span class="identifier">h</span></code> shall be invoked with an iterator object <code class="computeroutput"><span class="identifier">i</span></code> such that the condition <code class="computeroutput"><span class="identifier">i</span> <span class="special">!=</span> <span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_resolver_iterator</span><span class="special"><</span><span class="identifier">InternetProtocol</span><span class="special">>()</span></code> holds. Otherwise it is invoked with <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_resolver_iterator</span><span class="special"><</span><span class="identifier">InternetProtocol</span><span class="special">>()</span></code>. </p> </td> </tr> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">a</span><span class="special">.</span><span class="identifier">resolve</span><span class="special">(</span><span class="identifier">b</span><span class="special">,</span> <span class="identifier">e</span><span class="special">,</span> <span class="identifier">ec</span><span class="special">);</span> </pre> <p> </p> </td> <td> <p> </p> <pre class="programlisting"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_resolver_iterator</span><span class="special"><</span> <span class="identifier">InternetProtocol</span><span class="special">></span> </pre> <p> </p> </td> <td> <p> On success, returns an iterator <code class="computeroutput"><span class="identifier">i</span></code> such that <code class="computeroutput"><span class="identifier">i</span> <span class="special">!=</span> <span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_resolver_iterator</span><span class="special"><</span><span class="identifier">InternetProtocol</span><span class="special">>()</span></code>. Otherwise returns <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_resolver_iterator</span><span class="special"><</span><span class="identifier">InternetProtocol</span><span class="special">>()</span></code>. </p> </td> </tr> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">a</span><span class="special">.</span><span class="identifier">async_resolve</span><span class="special">(</span><span class="identifier">b</span><span class="special">,</span> <span class="identifier">e</span><span class="special">,</span> <span class="identifier">h</span><span class="special">);</span> </pre> <p> </p> </td> <td> <p> </p> </td> <td> <p> Initiates an asynchronous resolve operation that is performed via the <code class="computeroutput"><span class="identifier">io_service</span></code> object <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">io_service</span><span class="special">()</span></code> and behaves according to <a class="link" href="asynchronous_operations.html" title="Requirements on asynchronous operations">asynchronous operation</a> requirements.<br> <br> If the operation completes successfully, the <code class="computeroutput"><span class="identifier">ResolveHandler</span></code> object <code class="computeroutput"><span class="identifier">h</span></code> shall be invoked with an iterator object <code class="computeroutput"><span class="identifier">i</span></code> such that the condition <code class="computeroutput"><span class="identifier">i</span> <span class="special">!=</span> <span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_resolver_iterator</span><span class="special"><</span><span class="identifier">InternetProtocol</span><span class="special">>()</span></code> holds. Otherwise it is invoked with <code class="computeroutput"><span class="identifier">ip</span><span class="special">::</span><span class="identifier">basic_resolver_iterator</span><span class="special"><</span><span class="identifier">InternetProtocol</span><span class="special">>()</span></code>. </p> </td> </tr> </tbody> </table></div> </div> <br class="table-break"> </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> <td align="right"><div class="copyright-footer">Copyright © 2003 - 2010 Christopher M. Kohlhoff<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> </div></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="ResolveHandler.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../home.png" alt="Home"></a><a accesskey="n" href="SerialPortService.html"><img src="../../next.png" alt="Next"></a> </div> </body> </html>