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 null_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="../../interprocess/indexes_reference.html#header.boost.interprocess.sync.null_mutex_hpp" title="Header <boost/interprocess/sync/null_mutex.hpp>"> 10<link rel="prev" href="named_upgradable_mutex.html" title="Class named_upgradable_mutex"> 11<link rel="next" href="scoped_lock.html" title="Class template scoped_lock"> 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++ 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25</div> 26<div class="refentry"> 27<a name="boost.interprocess.null_mutex"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Class null_mutex</span></h2> 30<p>boost::interprocess::null_mutex</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="../../interprocess/indexes_reference.html#header.boost.interprocess.sync.null_mutex_hpp" title="Header <boost/interprocess/sync/null_mutex.hpp>">boost/interprocess/sync/null_mutex.hpp</a>> 34 35</span> 36<span class="keyword">class</span> <a class="link" href="null_mutex.html" title="Class null_mutex">null_mutex</a> <span class="special">{</span> 37<span class="keyword">public</span><span class="special">:</span> 38 <span class="comment">// <a class="link" href="null_mutex.html#boost.interprocess.null_mutexconstruct-copy-destruct">construct/copy/destruct</a></span> 39 <a class="link" href="null_mutex.html#idm45304009885024-bb"><span class="identifier">null_mutex</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 40 <a class="link" href="null_mutex.html#idm45304009884320-bb"><span class="special">~</span><span class="identifier">null_mutex</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 41 42 <span class="comment">// <a class="link" href="null_mutex.html#idm45304009914864-bb">public member functions</a></span> 43 <span class="keyword">void</span> <a class="link" href="null_mutex.html#idm45304009914304-bb"><span class="identifier">lock</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 44 <span class="keyword">bool</span> <a class="link" href="null_mutex.html#idm45304009913136-bb"><span class="identifier">try_lock</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 45 <span class="keyword">bool</span> <a class="link" href="null_mutex.html#idm45304009911824-bb"><span class="identifier">timed_lock</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">ptime</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 46 <span class="keyword">void</span> <a class="link" href="null_mutex.html#idm45304009909808-bb"><span class="identifier">unlock</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 47 <span class="keyword">void</span> <a class="link" href="null_mutex.html#idm45304009908512-bb"><span class="identifier">lock_sharable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 48 <span class="keyword">bool</span> <a class="link" href="null_mutex.html#idm45304009907200-bb"><span class="identifier">try_lock_sharable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 49 <span class="keyword">bool</span> <a class="link" href="null_mutex.html#idm45304009905872-bb"><span class="identifier">timed_lock_sharable</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">ptime</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 50 <span class="keyword">void</span> <a class="link" href="null_mutex.html#idm45304009903840-bb"><span class="identifier">unlock_sharable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 51 <span class="keyword">void</span> <a class="link" href="null_mutex.html#idm45304009902528-bb"><span class="identifier">lock_upgradable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 52 <span class="keyword">bool</span> <a class="link" href="null_mutex.html#idm45304009901216-bb"><span class="identifier">try_lock_upgradable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 53 <span class="keyword">bool</span> <a class="link" href="null_mutex.html#idm45304009899888-bb"><span class="identifier">timed_lock_upgradable</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">ptime</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 54 <span class="keyword">void</span> <a class="link" href="null_mutex.html#idm45304009897856-bb"><span class="identifier">unlock_upgradable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 55 <span class="keyword">void</span> <a class="link" href="null_mutex.html#idm45304009896544-bb"><span class="identifier">unlock_and_lock_upgradable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 56 <span class="keyword">void</span> <a class="link" href="null_mutex.html#idm45304009895216-bb"><span class="identifier">unlock_and_lock_sharable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 57 <span class="keyword">void</span> <a class="link" href="null_mutex.html#idm45304009893904-bb"><span class="identifier">unlock_upgradable_and_lock_sharable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 58 <span class="keyword">void</span> <a class="link" href="null_mutex.html#idm45304009892576-bb"><span class="identifier">unlock_upgradable_and_lock</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 59 <span class="keyword">bool</span> <a class="link" href="null_mutex.html#idm45304009891248-bb"><span class="identifier">try_unlock_upgradable_and_lock</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 60 <span class="keyword">bool</span> <a class="link" href="null_mutex.html#idm45304009889904-bb"><span class="identifier">timed_unlock_upgradable_and_lock</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">ptime</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 61 <span class="keyword">bool</span> <a class="link" href="null_mutex.html#idm45304009887856-bb"><span class="identifier">try_unlock_sharable_and_lock</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 62 <span class="keyword">bool</span> <a class="link" href="null_mutex.html#idm45304009886528-bb"><span class="identifier">try_unlock_sharable_and_lock_upgradable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 63<span class="special">}</span><span class="special">;</span></pre></div> 64<div class="refsect1"> 65<a name="id-1.3.19.17.3.74.4.4"></a><h2>Description</h2> 66<p>Implements a mutex that simulates a mutex without doing any operation and simulates a successful operation. </p> 67<div class="refsect2"> 68<a name="id-1.3.19.17.3.74.4.4.3"></a><h3> 69<a name="boost.interprocess.null_mutexconstruct-copy-destruct"></a><code class="computeroutput">null_mutex</code> 70 public 71 construct/copy/destruct</h3> 72<div class="orderedlist"><ol class="orderedlist" type="1"> 73<li class="listitem"> 74<pre class="literallayout"><a name="idm45304009885024-bb"></a><span class="identifier">null_mutex</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 75<p>Constructor. Empty. </p> 76</li> 77<li class="listitem"> 78<pre class="literallayout"><a name="idm45304009884320-bb"></a><span class="special">~</span><span class="identifier">null_mutex</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 79<p>Destructor. Empty. </p> 80</li> 81</ol></div> 82</div> 83<div class="refsect2"> 84<a name="id-1.3.19.17.3.74.4.4.4"></a><h3> 85<a name="idm45304009914864-bb"></a><code class="computeroutput">null_mutex</code> public member functions</h3> 86<div class="orderedlist"><ol class="orderedlist" type="1"> 87<li class="listitem"> 88<pre class="literallayout"><span class="keyword">void</span> <a name="idm45304009914304-bb"></a><span class="identifier">lock</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>Simulates a mutex lock() operation. Empty function. </li> 89<li class="listitem"> 90<pre class="literallayout"><span class="keyword">bool</span> <a name="idm45304009913136-bb"></a><span class="identifier">try_lock</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 91<p>Simulates a mutex try_lock() operation. Equivalent to "return true;" </p> 92</li> 93<li class="listitem"> 94<pre class="literallayout"><span class="keyword">bool</span> <a name="idm45304009911824-bb"></a><span class="identifier">timed_lock</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">ptime</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span></pre> 95<p>Simulates a mutex timed_lock() operation. Equivalent to "return true;" </p> 96</li> 97<li class="listitem"> 98<pre class="literallayout"><span class="keyword">void</span> <a name="idm45304009909808-bb"></a><span class="identifier">unlock</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 99<p>Simulates a mutex unlock() operation. Empty function. </p> 100</li> 101<li class="listitem"> 102<pre class="literallayout"><span class="keyword">void</span> <a name="idm45304009908512-bb"></a><span class="identifier">lock_sharable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 103<p>Simulates a mutex lock_sharable() operation. Empty function. </p> 104</li> 105<li class="listitem"> 106<pre class="literallayout"><span class="keyword">bool</span> <a name="idm45304009907200-bb"></a><span class="identifier">try_lock_sharable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 107<p>Simulates a mutex try_lock_sharable() operation. Equivalent to "return true;" </p> 108</li> 109<li class="listitem"> 110<pre class="literallayout"><span class="keyword">bool</span> <a name="idm45304009905872-bb"></a><span class="identifier">timed_lock_sharable</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">ptime</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span></pre> 111<p>Simulates a mutex timed_lock_sharable() operation. Equivalent to "return true;" </p> 112</li> 113<li class="listitem"> 114<pre class="literallayout"><span class="keyword">void</span> <a name="idm45304009903840-bb"></a><span class="identifier">unlock_sharable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 115<p>Simulates a mutex unlock_sharable() operation. Empty function. </p> 116</li> 117<li class="listitem"> 118<pre class="literallayout"><span class="keyword">void</span> <a name="idm45304009902528-bb"></a><span class="identifier">lock_upgradable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 119<p>Simulates a mutex lock_upgradable() operation. Empty function. </p> 120</li> 121<li class="listitem"> 122<pre class="literallayout"><span class="keyword">bool</span> <a name="idm45304009901216-bb"></a><span class="identifier">try_lock_upgradable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 123<p>Simulates a mutex try_lock_upgradable() operation. Equivalent to "return true;" </p> 124</li> 125<li class="listitem"> 126<pre class="literallayout"><span class="keyword">bool</span> <a name="idm45304009899888-bb"></a><span class="identifier">timed_lock_upgradable</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">ptime</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span></pre> 127<p>Simulates a mutex timed_lock_upgradable() operation. Equivalent to "return true;" </p> 128</li> 129<li class="listitem"> 130<pre class="literallayout"><span class="keyword">void</span> <a name="idm45304009897856-bb"></a><span class="identifier">unlock_upgradable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 131<p>Simulates a mutex unlock_upgradable() operation. Empty function. </p> 132</li> 133<li class="listitem"> 134<pre class="literallayout"><span class="keyword">void</span> <a name="idm45304009896544-bb"></a><span class="identifier">unlock_and_lock_upgradable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 135<p>Simulates unlock_and_lock_upgradable(). Empty function. </p> 136</li> 137<li class="listitem"> 138<pre class="literallayout"><span class="keyword">void</span> <a name="idm45304009895216-bb"></a><span class="identifier">unlock_and_lock_sharable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 139<p>Simulates unlock_and_lock_sharable(). Empty function. </p> 140</li> 141<li class="listitem"> 142<pre class="literallayout"><span class="keyword">void</span> <a name="idm45304009893904-bb"></a><span class="identifier">unlock_upgradable_and_lock_sharable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 143<p>Simulates unlock_upgradable_and_lock_sharable(). Empty function. </p> 144</li> 145<li class="listitem"> 146<pre class="literallayout"><span class="keyword">void</span> <a name="idm45304009892576-bb"></a><span class="identifier">unlock_upgradable_and_lock</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 147<p>Simulates unlock_upgradable_and_lock(). Empty function. </p> 148</li> 149<li class="listitem"> 150<pre class="literallayout"><span class="keyword">bool</span> <a name="idm45304009891248-bb"></a><span class="identifier">try_unlock_upgradable_and_lock</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 151<p>Simulates try_unlock_upgradable_and_lock(). Equivalent to "return true;" </p> 152</li> 153<li class="listitem"> 154<pre class="literallayout"><span class="keyword">bool</span> <a name="idm45304009889904-bb"></a><span class="identifier">timed_unlock_upgradable_and_lock</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">ptime</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span></pre> 155<p>Simulates timed_unlock_upgradable_and_lock(). Equivalent to "return true;" </p> 156</li> 157<li class="listitem"> 158<pre class="literallayout"><span class="keyword">bool</span> <a name="idm45304009887856-bb"></a><span class="identifier">try_unlock_sharable_and_lock</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 159<p>Simulates try_unlock_sharable_and_lock(). Equivalent to "return true;" </p> 160</li> 161<li class="listitem"> 162<pre class="literallayout"><span class="keyword">bool</span> <a name="idm45304009886528-bb"></a><span class="identifier">try_unlock_sharable_and_lock_upgradable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 163<p>Simulates try_unlock_sharable_and_lock_upgradable(). Equivalent to "return true;" </p> 164</li> 165</ol></div> 166</div> 167</div> 168</div> 169<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 170<td align="left"></td> 171<td align="right"><div class="copyright-footer">Copyright © 2005-2015 Ion Gaztanaga<p> 172 Distributed under the Boost Software License, Version 1.0. (See accompanying 173 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>) 174 </p> 175</div></td> 176</tr></table> 177<hr> 178<div class="spirit-nav"> 179<a accesskey="p" href="named_upgradable_mutex.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../interprocess/indexes_reference.html#header.boost.interprocess.sync.null_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="scoped_lock.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 180</div> 181</body> 182</html> 183
