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>Class mutex</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="../../signals2/reference.html#header.boost.signals2.mutex_hpp" title="Header <boost/signals2/mutex.hpp>"> 10<link rel="prev" href="no_slots_error.html" title="Class no_slots_error"> 11<link rel="next" href="optional_last_value.html" title="Class template optional_last_value"> 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="no_slots_error.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../signals2/reference.html#header.boost.signals2.mutex_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="optional_last_value.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.signals2.mutex"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Class mutex</span></h2> 30<p>boost::signals2::mutex — A header-only mutex which implements the Lockable concept of Boost.Thread.</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="../../signals2/reference.html#header.boost.signals2.mutex_hpp" title="Header <boost/signals2/mutex.hpp>">boost/signals2/mutex.hpp</a>> 34 35</span> 36<span class="keyword">class</span> <a class="link" href="mutex.html" title="Class mutex">mutex</a> <span class="special">{</span> 37<span class="keyword">public</span><span class="special">:</span> 38 <span class="keyword">void</span> <a class="link" href="mutex.html#id-1_3_36_6_6_3_1_1_3_1-bb"><span class="identifier">lock</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 39 <span class="keyword">bool</span> <a class="link" href="mutex.html#id-1_3_36_6_6_3_1_1_3_2-bb"><span class="identifier">try_lock</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 40 <span class="keyword">void</span> <a class="link" href="mutex.html#id-1_3_36_6_6_3_1_1_3_3-bb"><span class="identifier">unlock</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 41<span class="special">}</span><span class="special">;</span></pre></div> 42<div class="refsect1"> 43<a name="id-1.3.36.6.7.3.4"></a><h2>Description</h2> 44<p> 45 The <code class="computeroutput">mutex</code> class implements the <code class="computeroutput">Lockable</code> 46 concept of Boost.Thread, and is the default <code class="computeroutput">Mutex</code> template parameter 47 type for signals. 48 If boost has detected thread support in your compiler, the <code class="computeroutput">mutex</code> 49 class will map to a CRITICAL_SECTION on Windows 50 or a pthread_mutex on POSIX. If thread support is not detected, <code class="computeroutput">mutex</code> 51 will behave similarly to a <a class="link" href="dummy_mutex.html" title="Class dummy_mutex">dummy_mutex</a>. 52 The header file <code class="computeroutput">boost/config.hpp</code> 53 defines the macro <code class="computeroutput">BOOST_HAS_THREADS</code> when boost detects threading support. 54 The user may globally disable thread support 55 in boost by defining BOOST_DISABLE_THREADS before any boost header files are included. 56 </p> 57<p> 58 If you are already using the Boost.Thread library, you may prefer to use its 59 boost::mutex class instead as the mutex type for your signals. 60 </p> 61<p> 62 You may wish to use a thread-unsafe signal, if 63 the signal is only used by a single thread. In that case, you may prefer to 64 use the <a class="link" href="dummy_mutex.html" title="Class dummy_mutex">signals2::dummy_mutex</a> class as the <code class="computeroutput">Mutex</code> 65 template type for your signal. 66 </p> 67<pre class="literallayout"><span class="keyword">void</span> <a name="id-1_3_36_6_6_3_1_1_3_1-bb"></a><span class="identifier">lock</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 68<p>Locks the mutex. 69 </p> 70<pre class="literallayout"><span class="keyword">bool</span> <a name="id-1_3_36_6_6_3_1_1_3_2-bb"></a><span class="identifier">try_lock</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 71<p>Makes a non-blocking attempt to lock the mutex. 72 </p> 73<div class="variablelist"><table border="0" class="variablelist compact"> 74<colgroup> 75<col align="left" valign="top"> 76<col> 77</colgroup> 78<tbody><tr> 79<td><p><span class="term">Returns:</span></p></td> 80<td><p><code class="computeroutput">true</code> on success.</p></td> 81</tr></tbody> 82</table></div> 83<pre class="literallayout"><span class="keyword">void</span> <a name="id-1_3_36_6_6_3_1_1_3_3-bb"></a><span class="identifier">unlock</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 84<p>Unlocks the mutex. 85 </p> 86</div> 87</div> 88<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 89<td align="left"></td> 90<td align="right"><div class="copyright-footer">Copyright © 2001-2004 Douglas Gregor<br>Copyright © 2007-2009 Frank Mori Hess<p>Distributed under the Boost 91 Software License, Version 1.0. (See accompanying file 92 <code class="filename">LICENSE_1_0.txt</code> 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> 93</div></td> 94</tr></table> 95<hr> 96<div class="spirit-nav"> 97<a accesskey="p" href="no_slots_error.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../signals2/reference.html#header.boost.signals2.mutex_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="optional_last_value.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 98</div> 99</body> 100</html> 101
