<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Object HANDLEs</title> <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="../../../boost_asio.html" title="Boost.Asio"> <link rel="up" href="../windows.html" title="Windows-Specific Functionality"> <link rel="prev" href="random_access_handle.html" title="Random-Access HANDLEs"> <link rel="next" href="../ssl.html" title="SSL"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> <td align="center"><a href="../../../../../index.html">Home</a></td> <td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../../../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="random_access_handle.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../windows.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../boost_asio.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../ssl.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h4 class="title"> <a name="boost_asio.overview.windows.object_handle"></a><a class="link" href="object_handle.html" title="Object HANDLEs">Object HANDLEs</a> </h4></div></div></div> <p> Boost.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" style="list-style-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 </li> <li class="listitem"> Semaphore </li> <li class="listitem"> Thread </li> <li class="listitem"> Waitable timer </li> </ul></div> <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_service</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="boost_asio.overview.windows.object_handle.h0"></a> <span class="phrase"><a name="boost_asio.overview.windows.object_handle.see_also"></a></span><a class="link" href="object_handle.html#boost_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>, <a class="link" href="../../reference/windows__basic_object_handle.html" title="windows::basic_object_handle">windows::basic_object_handle</a>, <a class="link" href="../../reference/windows__object_handle_service.html" title="windows::object_handle_service">windows::object_handle_service</a>. </p> <h6> <a name="boost_asio.overview.windows.object_handle.h1"></a> <span class="phrase"><a name="boost_asio.overview.windows.object_handle.notes"></a></span><a class="link" href="object_handle.html#boost_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">BOOST_ASIO_HAS_WINDOWS_OBJECT_HANDLE</span></code> to determine whether they are supported. </p> </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> <td align="right"><div class="copyright-footer">Copyright © 2003-2015 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>) </p> </div></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="random_access_handle.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../windows.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../boost_asio.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../ssl.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>