1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html> 3<head> 4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 5<title>Struct async_handler</title> 6<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> 7<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 8<link rel="home" href="../../../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> 9<link rel="up" href="../../../process/reference.html#header.boost.process.extend_hpp" title="Header <boost/process/extend.hpp>"> 10<link rel="prev" href="../exe.html" title="Global exe"> 11<link rel="next" href="handler.html" title="Struct handler"> 12</head> 13<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 14<table cellpadding="2" width="100%"><tr> 15<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> 16<td align="center"><a href="../../../../../index.html">Home</a></td> 17<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> 18<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 19<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 20<td align="center"><a href="../../../../../more/index.htm">More</a></td> 21</tr></table> 22<hr> 23<div class="spirit-nav"> 24<a accesskey="p" href="../exe.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../process/reference.html#header.boost.process.extend_hpp"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="handler.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.process.extend.async_handler"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Struct async_handler</span></h2> 30<p>boost::process::extend::async_handler</p> 31</div> 32<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 33<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../../process/reference.html#header.boost.process.extend_hpp" title="Header <boost/process/extend.hpp>">boost/process/extend.hpp</a>> 34 35</span> 36<span class="keyword">struct</span> <a class="link" href="async_handler.html" title="Struct async_handler">async_handler</a> <span class="special">:</span> <span class="keyword">public</span> boost::process::extend::handler, 37 <span class="keyword">public</span> boost::process::extend::require_io_context 38<span class="special">{</span> 39<span class="special">}</span><span class="special">;</span></pre></div> 40<div class="refsect1"> 41<a name="id-1.3.30.9.13.5.4"></a><h2>Description</h2> 42<p>Inheriting this class will tell the launching function, that an event handler shall be invoked when the process exits. This automatically does also inherit <a class="link" href="require_io_context.html" title="Struct require_io_context">require_io_context</a>.</p> 43<p>You must add the following function to your implementation:</p> 44<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Executor</span><span class="special">></span> 45<span class="identifier">std</span><span class="special">::</span><span class="identifier">function</span><span class="special"><</span><span class="keyword">void</span><span class="special">(</span><span class="keyword">int</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">error_code</span><span class="special">&</span><span class="special">)</span><span class="special">></span> <span class="identifier">on_exit_handler</span><span class="special">(</span><span class="identifier">Executor</span> <span class="special">&</span> <span class="identifier">exec</span><span class="special">)</span> 46<span class="special">{</span> 47 <span class="keyword">auto</span> <span class="identifier">handler_</span> <span class="special">=</span> <span class="keyword">this</span><span class="special">-></span><span class="identifier">handler</span><span class="special">;</span> 48 <span class="keyword">return</span> <span class="special">[</span><span class="identifier">handler_</span><span class="special">]</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">exit_code</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">error_code</span> <span class="special">&</span> <span class="identifier">ec</span><span class="special">)</span> 49 <span class="special">{</span> 50 <span class="identifier">handler_</span><span class="special">(</span><span class="keyword">static_cast</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span><span class="special">(</span><span class="identifier">exit_code</span><span class="special">)</span><span class="special">,</span> <span class="identifier">ec</span><span class="special">)</span><span class="special">;</span> 51 <span class="special">}</span><span class="special">;</span> 52 53<span class="special">}</span> 54</pre> 55<p>The callback will be obtained by calling this function on setup and it will be invoked when the process exits.</p> 56<div class="warning"><table border="0" summary="Warning"> 57<tr> 58<td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../../../doc/src/images/warning.png"></td> 59<th align="left">Warning</th> 60</tr> 61<tr><td align="left" valign="top"><p>Cannot be used with boost::process::spawn </p></td></tr> 62</table></div> 63<p> 64</p> 65</div> 66</div> 67<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 68<td align="left"></td> 69<td align="right"><div class="copyright-footer">Copyright © 2006-2012 Julio M. Merino Vidal, Ilya Sokolov, 70 Felipe Tanus, Jeff Flinn, Boris Schaeling<br>Copyright © 2016 Klemens D. Morgenstern<p> 71 Distributed under the Boost Software License, Version 1.0. (See accompanying 72 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 73 </p> 74</div></td> 75</tr></table> 76<hr> 77<div class="spirit-nav"> 78<a accesskey="p" href="../exe.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../process/reference.html#header.boost.process.extend_hpp"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="handler.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 79</div> 80</body> 81</html> 82
