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<a name="boost.log.attributes.timer"></a><div class="titlepage"></div>
<span class="keyword">typedef</span> <span class="identifier">utc_time_traits</span><span class="special">::</span><span class="identifier">time_type</span><span class="special">::</span><span class="identifier">time_duration_type</span> <a name="boost.log.attributes.timer.value_type"></a><span class="identifier">value_type</span><span class="special">;</span> <span class="comment">// Attribute value type. </span>
<span class="comment">// <a class="link" href="timer.html#boost.log.attributes.timerconstruct-copy-destruct">construct/copy/destruct</a></span>
- <a class="link" href="timer.html#idm45185966849200-bb"><span class="identifier">timer</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
- <span class="keyword">explicit</span> <a class="link" href="timer.html#idm45185966848480-bb"><span class="identifier">timer</span></a><span class="special">(</span><a class="link" href="cast_source.html" title="Class cast_source">cast_source</a> <span class="keyword">const</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
+ <a class="link" href="timer.html#idm45711348449920-bb"><span class="identifier">timer</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
+ <span class="keyword">explicit</span> <a class="link" href="timer.html#idm45711348449200-bb"><span class="identifier">timer</span></a><span class="special">(</span><a class="link" href="cast_source.html" title="Class cast_source">cast_source</a> <span class="keyword">const</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="idm46436918807088"></a><h2>Description</h2>
+<a name="idm45554750299680"></a><h2>Description</h2>
<p>The timer attribute calculates the time passed since its construction and returns it on value acquisition. The attribute value type is <code class="computeroutput">boost::posix_time::time_duration</code>.</p>
<p>On Windows platform there are two implementations of the attribute. The default one is more precise but a bit slower. This version uses <code class="computeroutput">QueryPerformanceFrequence</code>/<code class="computeroutput">QueryPerformanceCounter</code> API to calculate elapsed time.</p>
<p>There are known problems with these functions when used with some CPUs, notably AMD Athlon with Cool'n'Quiet technology enabled. See the following links for more information and possible resolutions:</p>
<p><a href="http://support.microsoft.com/?scid=kb;en-us;895980" target="_top">http://support.microsoft.com/?scid=kb;en-us;895980</a> <a href="http://support.microsoft.com/?id=896256" target="_top">http://support.microsoft.com/?id=896256</a></p>
<p>In case if none of these solutions apply, you are free to define <code class="computeroutput">BOOST_LOG_NO_QUERY_PERFORMANCE_COUNTER</code> macro to fall back to another implementation based on Boost.DateTime. </p>
<div class="refsect2">
-<a name="idm46436918800704"></a><h3>
+<a name="idm45554750293296"></a><h3>
<a name="boost.log.attributes.timerconstruct-copy-destruct"></a><code class="computeroutput">timer</code>
public
construct/copy/destruct</h3>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">
-<pre class="literallayout"><a name="idm45185966849200-bb"></a><span class="identifier">timer</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
+<pre class="literallayout"><a name="idm45711348449920-bb"></a><span class="identifier">timer</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Constructor. Starts time counting. </p>
</li>
<li class="listitem">
-<pre class="literallayout"><span class="keyword">explicit</span> <a name="idm45185966848480-bb"></a><span class="identifier">timer</span><span class="special">(</span><a class="link" href="cast_source.html" title="Class cast_source">cast_source</a> <span class="keyword">const</span> <span class="special">&</span> source<span class="special">)</span><span class="special">;</span></pre>
+<pre class="literallayout"><span class="keyword">explicit</span> <a name="idm45711348449200-bb"></a><span class="identifier">timer</span><span class="special">(</span><a class="link" href="cast_source.html" title="Class cast_source">cast_source</a> <span class="keyword">const</span> <span class="special">&</span> source<span class="special">)</span><span class="special">;</span></pre>
<p>Constructor for casting support </p>
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