doc/html/boost/interprocess/interprocess_semaphore.html

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  26 <div class="refentry">
  27 <a name="boost.interprocess.interprocess_semaphore"></a><div class="titlepage"></div>
  28 <div class="refnamediv">
  29 <h2><span class="refentrytitle">Class interprocess_semaphore</span></h2>
  30 <p>boost::interprocess::interprocess_semaphore</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: &lt;<a class="link" href="../../interprocess/indexes_reference.html#header.boost.interprocess.sync.interprocess_semaphore_hpp" title="Header &lt;boost/interprocess/sync/interprocess_semaphore.hpp&gt;">boost/interprocess/sync/interprocess_semaphore.hpp</a>&gt;
  34
  35 </span>
  36 <span class="keyword">class</span> <a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a> <span class="special">{</span>
  37 <span class="keyword">public</span><span class="special">:</span>
  38   <span class="comment">// <a class="link" href="interprocess_semaphore.html#boost.interprocess.interprocess_semaphoreconstruct-copy-destruct">construct/copy/destruct</a></span>
  39   <a class="link" href="interprocess_semaphore.html#idm45336640544080-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>
  40   <a class="link" href="interprocess_semaphore.html#idm45336640541168-bb"><span class="special">~</span><span class="identifier">interprocess_semaphore</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
  41
  42   <span class="comment">// <a class="link" href="interprocess_semaphore.html#idm45336640560896-bb">public member functions</a></span>
  43   <span class="keyword">void</span> <a class="link" href="interprocess_semaphore.html#idm45336640560336-bb"><span class="identifier">post</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
  44   <span class="keyword">void</span> <a class="link" href="interprocess_semaphore.html#idm45336640556688-bb"><span class="identifier">wait</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
  45   <span class="keyword">bool</span> <a class="link" href="interprocess_semaphore.html#idm45336640553056-bb"><span class="identifier">try_wait</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
  46   <span class="keyword">bool</span> <a class="link" href="interprocess_semaphore.html#idm45336640549424-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">&amp;</span><span class="special">)</span><span class="special">;</span>
  47 <span class="special">}</span><span class="special">;</span></pre></div>
  48 <div class="refsect1">
  49 <a name="id-1.3.19.17.3.62.4.4"></a><h2>Description</h2>
  50 <p>Wraps a <a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a> that can be placed in shared memory and can be shared between processes. Allows timed lock tries </p>
  51 <div class="refsect2">
  52 <a name="id-1.3.19.17.3.62.4.4.3"></a><h3>
  53 <a name="boost.interprocess.interprocess_semaphoreconstruct-copy-destruct"></a><code class="computeroutput">interprocess_semaphore</code>
  54         public
  55        construct/copy/destruct</h3>
  56 <div class="orderedlist"><ol class="orderedlist" type="1">
  57 <li class="listitem">
  58 <pre class="literallayout"><a name="idm45336640544080-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>
  59 <p>Creates a <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code> with the given initial count. <code class="computeroutput"><a class="link" href="interprocess_exception.html" title="Class interprocess_exception">interprocess_exception</a></code> if there is an error. </p>
  60 </li>
  61 <li class="listitem">
  62 <pre class="literallayout"><a name="idm45336640541168-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>
  63 <p>Destroys the <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code>. Does not throw </p>
  64 </li>
  65 </ol></div>
  66 </div>
  67 <div class="refsect2">
  68 <a name="id-1.3.19.17.3.62.4.4.4"></a><h3>
  69 <a name="idm45336640560896-bb"></a><code class="computeroutput">interprocess_semaphore</code> public member functions</h3>
  70 <div class="orderedlist"><ol class="orderedlist" type="1">
  71 <li class="listitem">
  72 <pre class="literallayout"><span class="keyword">void</span> <a name="idm45336640560336-bb"></a><span class="identifier">post</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
  73 <p>Increments the <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code> count. If there are processes/threads blocked waiting for the <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code>, then one of these processes will return successfully from its wait function. If there is an error an <code class="computeroutput"><a class="link" href="interprocess_exception.html" title="Class interprocess_exception">interprocess_exception</a></code> exception is thrown. </p>
  74 </li>
  75 <li class="listitem">
  76 <pre class="literallayout"><span class="keyword">void</span> <a name="idm45336640556688-bb"></a><span class="identifier">wait</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
  77 <p>Decrements the <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code>. If the <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code> value is not greater than zero, then the calling process/thread blocks until it can decrement the counter. If there is an error an <code class="computeroutput"><a class="link" href="interprocess_exception.html" title="Class interprocess_exception">interprocess_exception</a></code> exception is thrown. </p>
  78 </li>
  79 <li class="listitem">
  80 <pre class="literallayout"><span class="keyword">bool</span> <a name="idm45336640553056-bb"></a><span class="identifier">try_wait</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
  81 <p>Decrements the <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code> if the <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code>'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 <code class="computeroutput"><a class="link" href="interprocess_exception.html" title="Class interprocess_exception">interprocess_exception</a></code> exception is thrown. </p>
  82 </li>
  83 <li class="listitem">
  84 <pre class="literallayout"><span class="keyword">bool</span> <a name="idm45336640549424-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">&amp;</span> abs_time<span class="special">)</span><span class="special">;</span></pre>
  85 <p>Decrements the <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code> if the <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code>'s value is greater than zero and returns true. Otherwise, waits for the <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code> to the posted or the timeout expires. If the timeout expires, the function returns false. If the <code class="computeroutput"><a class="link" href="interprocess_semaphore.html" title="Class interprocess_semaphore">interprocess_semaphore</a></code> is posted the function returns true. If there is an error throws sem_exception </p>
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