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| <a name="boost.interprocess.interprocess_semaphore"></a><div class="titlepage"></div> |
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| <h2><span class="refentrytitle">Class interprocess_semaphore</span></h2> |
| <p>boost::interprocess::interprocess_semaphore</p> |
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| <h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> |
| <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="../../boost_interprocess_reference.html#header.boost.interprocess.sync.interprocess_semaphore_hpp" title="Header <boost/interprocess/sync/interprocess_semaphore.hpp>">boost/interprocess/sync/interprocess_semaphore.hpp</a>> |
| |
| </span> |
| <span class="keyword">class</span> <a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a> <span class="special">{</span> |
| <span class="keyword">public</span><span class="special">:</span> |
| <span class="comment">// <a class="link" href="interprocess_semaphore.html#boost.interprocess.interprocess_semaphoreconstruct-copy-destruct">construct/copy/destruct</a></span> |
| <a class="link" href="interprocess_semaphore.html#id829276-bb"><span class="identifier">interprocess_semaphore</span></a><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> |
| <a class="link" href="interprocess_semaphore.html#id829288-bb"><span class="special">~</span><span class="identifier">interprocess_semaphore</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> |
| |
| <span class="comment">// <a class="link" href="interprocess_semaphore.html#id829204-bb">public member functions</a></span> |
| <span class="keyword">void</span> <a class="link" href="interprocess_semaphore.html#id829207-bb"><span class="identifier">post</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> |
| <span class="keyword">void</span> <a class="link" href="interprocess_semaphore.html#id829223-bb"><span class="identifier">wait</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> |
| <span class="keyword">bool</span> <a class="link" href="interprocess_semaphore.html#id829238-bb"><span class="identifier">try_wait</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> |
| <span class="keyword">bool</span> <a class="link" href="interprocess_semaphore.html#id829253-bb"><span class="identifier">timed_wait</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> |
| <span class="special">}</span><span class="special">;</span></pre></div> |
| <div class="refsect1"> |
| <a name="id1539425"></a><h2>Description</h2> |
| <p>Wraps a interprocess_semaphore that can be placed in shared memory and can be shared between processes. Allows timed lock tries </p> |
| <div class="refsect2"> |
| <a name="id1539433"></a><h3> |
| <a name="boost.interprocess.interprocess_semaphoreconstruct-copy-destruct"></a><code class="computeroutput">interprocess_semaphore</code> |
| public |
| construct/copy/destruct</h3> |
| <div class="orderedlist"><ol class="orderedlist" type="1"> |
| <li class="listitem"> |
| <pre class="literallayout"><a name="id829276-bb"></a><span class="identifier">interprocess_semaphore</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">int</span> initialCount<span class="special">)</span><span class="special">;</span></pre> |
| <p>Creates a interprocess_semaphore with the given initial count. interprocess_exception if there is an error. </p> |
| </li> |
| <li class="listitem"> |
| <pre class="literallayout"><a name="id829288-bb"></a><span class="special">~</span><span class="identifier">interprocess_semaphore</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> |
| <p>Destroys the interprocess_semaphore. Does not throw </p> |
| </li> |
| </ol></div> |
| </div> |
| <div class="refsect2"> |
| <a name="id1539535"></a><h3> |
| <a name="id829204-bb"></a><code class="computeroutput">interprocess_semaphore</code> public member functions</h3> |
| <div class="orderedlist"><ol class="orderedlist" type="1"> |
| <li class="listitem"> |
| <pre class="literallayout"><span class="keyword">void</span> <a name="id829207-bb"></a><span class="identifier">post</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> |
| <p>Increments the interprocess_semaphore count. If there are processes/threads blocked waiting for the interprocess_semaphore, then one of these processes will return successfully from its wait function. If there is an error an interprocess_exception exception is thrown. </p> |
| </li> |
| <li class="listitem"> |
| <pre class="literallayout"><span class="keyword">void</span> <a name="id829223-bb"></a><span class="identifier">wait</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> |
| <p>Decrements the interprocess_semaphore. If the interprocess_semaphore value is not greater than zero, then the calling process/thread blocks until it can decrement the counter. If there is an error an interprocess_exception exception is thrown. </p> |
| </li> |
| <li class="listitem"> |
| <pre class="literallayout"><span class="keyword">bool</span> <a name="id829238-bb"></a><span class="identifier">try_wait</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> |
| <p>Decrements the interprocess_semaphore if the interprocess_semaphore's value is greater than zero and returns true. If the value is not greater than zero returns false. If there is an error an interprocess_exception exception is thrown. </p> |
| </li> |
| <li class="listitem"> |
| <pre class="literallayout"><span class="keyword">bool</span> <a name="id829253-bb"></a><span class="identifier">timed_wait</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> abs_time<span class="special">)</span><span class="special">;</span></pre> |
| <p>Decrements the interprocess_semaphore if the interprocess_semaphore's value is greater than zero and returns true. Otherwise, waits for the interprocess_semaphore to the posted or the timeout expires. If the timeout expires, the function returns false. If the interprocess_semaphore is posted the function returns true. If there is an error throws sem_exception </p> |
| </li> |
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| <td align="right"><div class="copyright-footer">Copyright © 2005 - 2010 Ion Gaztanaga<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>) |
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