1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>io_context::run_one (1 of 2 overloads)</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="../run_one.html" title="io_context::run_one"> 9<link rel="prev" href="../run_one.html" title="io_context::run_one"> 10<link rel="next" href="overload2.html" title="io_context::run_one (2 of 2 overloads)"> 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="../run_one.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../run_one.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="overload2.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h5 class="title"> 27<a name="boost_asio.reference.io_context.run_one.overload1"></a><a class="link" href="overload1.html" title="io_context::run_one (1 of 2 overloads)">io_context::run_one 28 (1 of 2 overloads)</a> 29</h5></div></div></div> 30<p> 31 Run the <a class="link" href="../../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 32 object's event processing loop to execute at most one handler. 33 </p> 34<pre class="programlisting">count_type run_one(); 35</pre> 36<p> 37 The <code class="computeroutput">run_one()</code> function blocks until one handler has been 38 dispatched, or until the <a class="link" href="../../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 39 has been stopped. 40 </p> 41<h6> 42<a name="boost_asio.reference.io_context.run_one.overload1.h0"></a> 43 <span class="phrase"><a name="boost_asio.reference.io_context.run_one.overload1.return_value"></a></span><a class="link" href="overload1.html#boost_asio.reference.io_context.run_one.overload1.return_value">Return 44 Value</a> 45 </h6> 46<p> 47 The number of handlers that were executed. A zero return value implies 48 that the <a class="link" href="../../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 49 object is stopped (the <code class="computeroutput">stopped()</code> function returns <code class="computeroutput">true</code>). 50 Subsequent calls to <code class="computeroutput">run()</code>, <code class="computeroutput">run_one()</code>, <code class="computeroutput">poll()</code> 51 or <code class="computeroutput">poll_one()</code> will return immediately unless there is a 52 prior call to <code class="computeroutput">restart()</code>. 53 </p> 54<h6> 55<a name="boost_asio.reference.io_context.run_one.overload1.h1"></a> 56 <span class="phrase"><a name="boost_asio.reference.io_context.run_one.overload1.remarks"></a></span><a class="link" href="overload1.html#boost_asio.reference.io_context.run_one.overload1.remarks">Remarks</a> 57 </h6> 58<p> 59 Calling the <code class="computeroutput">run_one()</code> function from a thread that is currently 60 calling one of <code class="computeroutput">run()</code>, <code class="computeroutput">run_one()</code>, <code class="computeroutput">run_for()</code>, 61 <code class="computeroutput">run_until()</code>, <code class="computeroutput">poll()</code> or <code class="computeroutput">poll_one()</code> 62 on the same <a class="link" href="../../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 63 object may introduce the potential for deadlock. It is the caller's reponsibility 64 to avoid this. 65 </p> 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 © 2003-2020 Christopher M. 70 Kohlhoff<p> 71 Distributed under the Boost Software License, Version 1.0. (See accompanying 72 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>) 73 </p> 74</div></td> 75</tr></table> 76<hr> 77<div class="spirit-nav"> 78<a accesskey="p" href="../run_one.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../run_one.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="overload2.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 79</div> 80</body> 81</html> 82
