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| author | Anas Nashif <anas.nashif@intel.com> | 2012-10-30 12:57:26 -0700 |
|---|---|---|
| committer | Anas Nashif <anas.nashif@intel.com> | 2012-10-30 12:57:26 -0700 |
| commit | 1a78a62555be32868418fe52f8e330c9d0f95d5a (patch) | |
| tree | d3765a80e7d3b9640ec2e930743630cd6b9fce2b /doc/html/boost_asio/overview/timers.html | |
| download | boost-1a78a62555be32868418fe52f8e330c9d0f95d5a.tar.gz boost-1a78a62555be32868418fe52f8e330c9d0f95d5a.tar.bz2 boost-1a78a62555be32868418fe52f8e330c9d0f95d5a.zip | |
Imported Upstream version 1.49.0upstream/1.49.0
Diffstat (limited to 'doc/html/boost_asio/overview/timers.html')
| -rwxr-xr-x | doc/html/boost_asio/overview/timers.html | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/doc/html/boost_asio/overview/timers.html b/doc/html/boost_asio/overview/timers.html new file mode 100755 index 0000000000..162f4c5de0 --- /dev/null +++ b/doc/html/boost_asio/overview/timers.html @@ -0,0 +1,95 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Timers</title> +<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../../boost_asio.html" title="Boost.Asio"> +<link rel="up" href="../overview.html" title="Overview"> +<link rel="prev" href="networking/bsd_sockets.html" title="The BSD Socket API and Boost.Asio"> +<link rel="next" href="serial_ports.html" title="Serial Ports"> +</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="networking/bsd_sockets.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../overview.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="serial_ports.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="boost_asio.overview.timers"></a><a class="link" href="timers.html" title="Timers">Timers</a> +</h3></div></div></div> +<p> + Long running I/O operations will often have a deadline by which they must + have completed. These deadlines may be expressed as absolute times, but are + often calculated relative to the current time. + </p> +<p> + As a simple example, to perform a synchronous wait operation on a timer using + a relative time one may write: + </p> +<pre class="programlisting"><span class="identifier">io_service</span> <span class="identifier">i</span><span class="special">;</span> +<span class="special">...</span> +<span class="identifier">deadline_timer</span> <span class="identifier">t</span><span class="special">(</span><span class="identifier">i</span><span class="special">);</span> +<span class="identifier">t</span><span class="special">.</span><span class="identifier">expires_from_now</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">seconds</span><span class="special">(</span><span class="number">5</span><span class="special">));</span> +<span class="identifier">t</span><span class="special">.</span><span class="identifier">wait</span><span class="special">();</span> +</pre> +<p> + More commonly, a program will perform an asynchronous wait operation on a + timer: + </p> +<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">system</span><span class="special">::</span><span class="identifier">error_code</span> <span class="identifier">ec</span><span class="special">)</span> <span class="special">{</span> <span class="special">...</span> <span class="special">}</span> +<span class="special">...</span> +<span class="identifier">io_service</span> <span class="identifier">i</span><span class="special">;</span> +<span class="special">...</span> +<span class="identifier">deadline_timer</span> <span class="identifier">t</span><span class="special">(</span><span class="identifier">i</span><span class="special">);</span> +<span class="identifier">t</span><span class="special">.</span><span class="identifier">expires_from_now</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">milliseconds</span><span class="special">(</span><span class="number">400</span><span class="special">));</span> +<span class="identifier">t</span><span class="special">.</span><span class="identifier">async_wait</span><span class="special">(</span><span class="identifier">handler</span><span class="special">);</span> +<span class="special">...</span> +<span class="identifier">i</span><span class="special">.</span><span class="identifier">run</span><span class="special">();</span> +</pre> +<p> + The deadline associated with a timer may also be obtained as a relative time: + </p> +<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">time_duration</span> <span class="identifier">time_until_expiry</span> + <span class="special">=</span> <span class="identifier">t</span><span class="special">.</span><span class="identifier">expires_from_now</span><span class="special">();</span> +</pre> +<p> + or as an absolute time to allow composition of timers: + </p> +<pre class="programlisting"><span class="identifier">deadline_timer</span> <span class="identifier">t2</span><span class="special">(</span><span class="identifier">i</span><span class="special">);</span> +<span class="identifier">t2</span><span class="special">.</span><span class="identifier">expires_at</span><span class="special">(</span><span class="identifier">t</span><span class="special">.</span><span class="identifier">expires_at</span><span class="special">()</span> <span class="special">+</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">seconds</span><span class="special">(</span><span class="number">30</span><span class="special">));</span> +</pre> +<h5> +<a name="boost_asio.overview.timers.h0"></a> + <span><a name="boost_asio.overview.timers.see_also"></a></span><a class="link" href="timers.html#boost_asio.overview.timers.see_also">See + Also</a> + </h5> +<p> + <a class="link" href="../reference/basic_deadline_timer.html" title="basic_deadline_timer">basic_deadline_timer</a>, + <a class="link" href="../reference/deadline_timer.html" title="deadline_timer">deadline_timer</a>, + <a class="link" href="../reference/deadline_timer_service.html" title="deadline_timer_service">deadline_timer_service</a>, + <a class="link" href="../tutorial/tuttimer1.html" title="Timer.1 - Using a timer synchronously">timer tutorials</a>. + </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 © 2003-2012 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="networking/bsd_sockets.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../overview.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="serial_ports.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> |