Insane_DNS/libraries/asio-1.28.1/doc/asio/overview/windows/object_handle.html

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<div class="titlepage"><div><div><h4 class="title">
<a name="asio.overview.windows.object_handle"></a><a class="link" href="object_handle.html" title="Object HANDLEs">Object HANDLEs</a>
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<p>
Asio provides Windows-specific classes that permit asynchronous wait operations
to be performed on HANDLEs to kernel objects of the following types:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
Change notification
</li>
<li class="listitem">
Console input
</li>
<li class="listitem">
Event
</li>
<li class="listitem">
Memory resource notification
</li>
<li class="listitem">
Process
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Semaphore
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Thread
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Waitable timer
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<p>
For example, to perform asynchronous operations on an event, the following
object may be created:
</p>
<pre class="programlisting"><span class="identifier">HANDLE</span> <span class="identifier">handle</span> <span class="special">=</span> <span class="special">::</span><span class="identifier">CreateEvent</span><span class="special">(...);</span>
<span class="identifier">windows</span><span class="special">::</span><span class="identifier">object_handle</span> <span class="identifier">file</span><span class="special">(</span><span class="identifier">my_io_context</span><span class="special">,</span> <span class="identifier">handle</span><span class="special">);</span>
</pre>
<p>
The <code class="computeroutput"><span class="identifier">wait</span><span class="special">()</span></code>
and <code class="computeroutput"><span class="identifier">async_wait</span><span class="special">()</span></code>
member functions may then be used to wait until the kernel object is signalled.
</p>
<h6>
<a name="asio.overview.windows.object_handle.h0"></a>
<span><a name="asio.overview.windows.object_handle.see_also"></a></span><a class="link" href="object_handle.html#asio.overview.windows.object_handle.see_also">See
Also</a>
</h6>
<p>
<a class="link" href="../../reference/windows__object_handle.html" title="windows::object_handle">windows::object_handle</a>.
</p>
<h6>
<a name="asio.overview.windows.object_handle.h1"></a>
<span><a name="asio.overview.windows.object_handle.notes"></a></span><a class="link" href="object_handle.html#asio.overview.windows.object_handle.notes">Notes</a>
</h6>
<p>
Windows object <code class="computeroutput"><span class="identifier">HANDLE</span></code>s
are only available at compile time when targeting Windows. Programs may
test for the macro <code class="computeroutput"><span class="identifier">ASIO_HAS_WINDOWS_OBJECT_HANDLE</span></code>
to determine whether they are supported.
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<div class="copyright-footer">Copyright © 2003-2023 Christopher M. Kohlhoff<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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