<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>spawn</title> <link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="../../boost_asio.html" title="Boost.Asio"> <link rel="up" href="../reference.html" title="Reference"> <link rel="prev" href="socket_base/_socket_base.html" title="socket_base::~socket_base"> <link rel="next" href="spawn/overload1.html" title="spawn (1 of 4 overloads)"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> <td align="center"><a href="../../../../index.html">Home</a></td> <td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a 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class="programlisting"><span class="keyword">template</span><span class="special"><</span> <span class="keyword">typename</span> <a class="link" href="Handler.html" title="Handlers">Handler</a><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Function</span><span class="special">></span> <span class="keyword">void</span> <a class="link" href="spawn/overload1.html" title="spawn (1 of 4 overloads)">spawn</a><span class="special">(</span> <span class="identifier">Handler</span> <span class="identifier">handler</span><span class="special">,</span> <span class="identifier">Function</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">coroutines</span><span class="special">::</span><span class="identifier">attributes</span> <span class="special">&</span> <span class="identifier">attributes</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">coroutines</span><span class="special">::</span><span class="identifier">attributes</span><span class="special">());</span> <span class="emphasis"><em>» <a class="link" href="spawn/overload1.html" title="spawn (1 of 4 overloads)">more...</a></em></span> <span class="keyword">template</span><span class="special"><</span> <span class="keyword">typename</span> <a class="link" href="Handler.html" title="Handlers">Handler</a><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Function</span><span class="special">></span> <span class="keyword">void</span> <a class="link" href="spawn/overload2.html" title="spawn (2 of 4 overloads)">spawn</a><span class="special">(</span> <span class="identifier">basic_yield_context</span><span class="special"><</span> <span class="identifier">Handler</span> <span class="special">></span> <span class="identifier">ctx</span><span class="special">,</span> <span class="identifier">Function</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">coroutines</span><span class="special">::</span><span class="identifier">attributes</span> <span class="special">&</span> <span class="identifier">attributes</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">coroutines</span><span class="special">::</span><span class="identifier">attributes</span><span class="special">());</span> <span class="emphasis"><em>» <a class="link" href="spawn/overload2.html" title="spawn (2 of 4 overloads)">more...</a></em></span> <span class="keyword">template</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">Function</span><span class="special">></span> <span class="keyword">void</span> <a class="link" href="spawn/overload3.html" title="spawn (3 of 4 overloads)">spawn</a><span class="special">(</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">strand</span> <span class="identifier">strand</span><span class="special">,</span> <span class="identifier">Function</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">coroutines</span><span class="special">::</span><span class="identifier">attributes</span> <span class="special">&</span> <span class="identifier">attributes</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">coroutines</span><span class="special">::</span><span class="identifier">attributes</span><span class="special">());</span> <span class="emphasis"><em>» <a class="link" href="spawn/overload3.html" title="spawn (3 of 4 overloads)">more...</a></em></span> <span class="keyword">template</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">Function</span><span class="special">></span> <span class="keyword">void</span> <a class="link" href="spawn/overload4.html" title="spawn (4 of 4 overloads)">spawn</a><span class="special">(</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">io_service</span> <span class="special">&</span> <span class="identifier">io_service</span><span class="special">,</span> <span class="identifier">Function</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">coroutines</span><span class="special">::</span><span class="identifier">attributes</span> <span class="special">&</span> <span class="identifier">attributes</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">coroutines</span><span class="special">::</span><span class="identifier">attributes</span><span class="special">());</span> <span class="emphasis"><em>» <a class="link" href="spawn/overload4.html" title="spawn (4 of 4 overloads)">more...</a></em></span> </pre> <p> The <code class="computeroutput"><span class="identifier">spawn</span><span class="special">()</span></code> function is a high-level wrapper over the Boost.Coroutine library. This function enables programs to implement asynchronous logic in a synchronous manner, as illustrated by the following example: </p> <pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">spawn</span><span class="special">(</span><span class="identifier">my_strand</span><span class="special">,</span> <span class="identifier">do_echo</span><span class="special">);</span> <span class="comment">// ...</span> <span class="keyword">void</span> <span class="identifier">do_echo</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">yield_context</span> <span class="identifier">yield</span><span class="special">)</span> <span class="special">{</span> <span class="keyword">try</span> <span class="special">{</span> <span class="keyword">char</span> <span class="identifier">data</span><span class="special">[</span><span class="number">128</span><span class="special">];</span> <span class="keyword">for</span> <span class="special">(;;)</span> <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">length</span> <span class="special">=</span> <span class="identifier">my_socket</span><span class="special">.</span><span class="identifier">async_read_some</span><span class="special">(</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">data</span><span class="special">),</span> <span class="identifier">yield</span><span class="special">);</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">async_write</span><span class="special">(</span><span class="identifier">my_socket</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">data</span><span class="special">,</span> <span class="identifier">length</span><span class="special">),</span> <span class="identifier">yield</span><span class="special">);</span> <span class="special">}</span> <span class="special">}</span> <span class="keyword">catch</span> <span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">exception</span><span class="special">&</span> <span class="identifier">e</span><span class="special">)</span> <span class="special">{</span> <span class="comment">// ...</span> <span class="special">}</span> <span class="special">}</span> </pre> <h5> <a name="boost_asio.reference.spawn.h0"></a> <span class="phrase"><a name="boost_asio.reference.spawn.requirements"></a></span><a class="link" href="spawn.html#boost_asio.reference.spawn.requirements">Requirements</a> </h5> <p> <span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/spawn.hpp</code> </p> <p> <span class="emphasis"><em>Convenience header: </em></span>None </p> </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 © 2003-2015 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="socket_base/_socket_base.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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="spawn/overload1.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>