<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Buffer-oriented asynchronous write stream requirements</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="../reference.html" title="Reference"> <link rel="prev" href="AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements"> <link rel="next" href="BufferedHandshakeHandler.html" title="Buffered handshake handler requirements"> </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="AsyncReadStream.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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="BufferedHandshakeHandler.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.reference.AsyncWriteStream"></a><a class="link" href="AsyncWriteStream.html" title="Buffer-oriented asynchronous write stream requirements">Buffer-oriented asynchronous write stream requirements</a> </h3></div></div></div> <p> In the table below, <code class="computeroutput"><span class="identifier">a</span></code> denotes an asynchronous write stream object, <code class="computeroutput"><span class="identifier">cb</span></code> denotes an object satisfying <a class="link" href="ConstBufferSequence.html" title="Constant buffer sequence requirements">constant buffer sequence</a> requirements, and <code class="computeroutput"><span class="identifier">h</span></code> denotes an object satisfying <a class="link" href="WriteHandler.html" title="Write handler requirements">write handler</a> requirements. </p> <div class="table"> <a name="boost_asio.reference.AsyncWriteStream.t0"></a><p class="title"><b>Table 4. Buffer-oriented asynchronous write stream requirements</b></p> <div class="table-contents"><table class="table" summary="Buffer-oriented asynchronous write stream requirements"> <colgroup> <col> <col> <col> </colgroup> <thead><tr> <th> <p> operation </p> </th> <th> <p> type </p> </th> <th> <p> semantics, pre/post-conditions </p> </th> </tr></thead> <tbody> <tr> <td> <p> <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">get_io_service</span><span class="special">();</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">io_service</span><span class="special">&</span></code> </p> </td> <td> <p> Returns the <code class="computeroutput"><span class="identifier">io_service</span></code> object through which the <code class="computeroutput"><span class="identifier">async_write_some</span></code> handler <code class="computeroutput"><span class="identifier">h</span></code> will be invoked. </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">async_write_some</span><span class="special">(</span><span class="identifier">cb</span><span class="special">,</span> <span class="identifier">h</span><span class="special">);</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="keyword">void</span></code> </p> </td> <td> <p> Initiates an asynchronous operation to write one or more bytes of data to the stream <code class="computeroutput"><span class="identifier">a</span></code>. The operation is performed via the <code class="computeroutput"><span class="identifier">io_service</span></code> object <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">get_io_service</span><span class="special">()</span></code> and behaves according to <a class="link" href="asynchronous_operations.html" title="Requirements on asynchronous operations">asynchronous operation</a> requirements.<br> <br> The constant buffer sequence <code class="computeroutput"><span class="identifier">cb</span></code> specifies memory where the data to be written is located. The <code class="computeroutput"><span class="identifier">async_write_some</span></code> operation shall always write a buffer in the sequence completely before proceeding to the next.<br> <br> The implementation shall maintain one or more copies of <code class="computeroutput"><span class="identifier">cb</span></code> until such time as the write operation no longer requires access to the memory specified by the buffers in the sequence. The program must ensure the memory is valid until:<br> <br> — the last copy of <code class="computeroutput"><span class="identifier">cb</span></code> is destroyed, or<br> <br> — the handler for the asynchronous write operation is invoked,<br> <br> whichever comes first.<br> <br> If the total size of all buffers in the sequence <code class="computeroutput"><span class="identifier">cb</span></code> is <code class="computeroutput"><span class="number">0</span></code>, the asynchronous write operation shall complete immediately and pass <code class="computeroutput"><span class="number">0</span></code> as the argument to the handler that specifies the number of bytes written. </p> </td> </tr> </tbody> </table></div> </div> <br class="table-break"> </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="AsyncReadStream.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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="BufferedHandshakeHandler.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>