1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>io_context::dispatch</title> 5<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../boost_asio.html" title="Boost.Asio"> 8<link rel="up" href="../io_context.html" title="io_context"> 9<link rel="prev" href="destroy.html" title="io_context::destroy"> 10<link rel="next" href="executor_type.html" title="io_context::executor_type"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="destroy.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../io_context.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../boost_asio.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="executor_type.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h4 class="title"> 27<a name="boost_asio.reference.io_context.dispatch"></a><a class="link" href="dispatch.html" title="io_context::dispatch">io_context::dispatch</a> 28</h4></div></div></div> 29<p> 30 <a class="indexterm" name="boost_asio.indexterm.io_context.dispatch"></a> 31(Deprecated: 32 Use <a class="link" href="../dispatch.html" title="dispatch"><code class="computeroutput">dispatch</code></a>.) 33 Request the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 34 to invoke the given handler. 35 </p> 36<pre class="programlisting">template< 37 typename <a class="link" href="../LegacyCompletionHandler.html" title="Legacy completion handler requirements">LegacyCompletionHandler</a>> 38<a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.automatic_deduction_of_initiating_function_return_type"><span class="emphasis"><em>DEDUCED</em></span></a> dispatch( 39 LegacyCompletionHandler && handler); 40</pre> 41<p> 42 This function is used to ask the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 43 to execute the given handler. 44 </p> 45<p> 46 The <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 47 guarantees that the handler will only be called in a thread in which the 48 <code class="computeroutput">run()</code>, <code class="computeroutput">run_one()</code>, <code class="computeroutput">poll()</code> or <code class="computeroutput">poll_one()</code> 49 member functions is currently being invoked. The handler may be executed 50 inside this function if the guarantee can be met. 51 </p> 52<h6> 53<a name="boost_asio.reference.io_context.dispatch.h0"></a> 54 <span class="phrase"><a name="boost_asio.reference.io_context.dispatch.parameters"></a></span><a class="link" href="dispatch.html#boost_asio.reference.io_context.dispatch.parameters">Parameters</a> 55 </h6> 56<div class="variablelist"> 57<p class="title"><b></b></p> 58<dl class="variablelist"> 59<dt><span class="term">handler</span></dt> 60<dd> 61<p> 62 The handler to be called. The <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 63 will make a copy of the handler object as required. The function 64 signature of the handler must be: 65</p> 66<pre class="programlisting">void handler(); 67</pre> 68<p> 69 </p> 70</dd> 71</dl> 72</div> 73<h6> 74<a name="boost_asio.reference.io_context.dispatch.h1"></a> 75 <span class="phrase"><a name="boost_asio.reference.io_context.dispatch.remarks"></a></span><a class="link" href="dispatch.html#boost_asio.reference.io_context.dispatch.remarks">Remarks</a> 76 </h6> 77<p> 78 This function throws an exception only if: 79 </p> 80<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 81<li class="listitem"> 82 the handler's <code class="computeroutput">asio_handler_allocate</code> function; or 83 </li> 84<li class="listitem"> 85 the handler's copy constructor 86 </li> 87</ul></div> 88<p> 89 throws an exception. 90 </p> 91</div> 92<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 93<td align="left"></td> 94<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 95 Kohlhoff<p> 96 Distributed under the Boost Software License, Version 1.0. (See accompanying 97 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>) 98 </p> 99</div></td> 100</tr></table> 101<hr> 102<div class="spirit-nav"> 103<a accesskey="p" href="destroy.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../io_context.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../boost_asio.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="executor_type.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 104</div> 105</body> 106</html> 107
