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| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="boost_asio.reference.AsyncReadStream"></a><a class="link" href="AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements">Buffer-oriented |
| asynchronous read stream requirements</a> |
| </h3></div></div></div> |
| <p> |
| In the table below, <code class="computeroutput"><span class="identifier">a</span></code> denotes |
| an asynchronous read stream object, <code class="computeroutput"><span class="identifier">mb</span></code> |
| denotes an object satisfying <a class="link" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements">mutable |
| buffer sequence</a> requirements, and <code class="computeroutput"><span class="identifier">h</span></code> |
| denotes an object satisfying <a class="link" href="ReadHandler.html" title="Read handler requirements">read |
| handler</a> requirements. |
| </p> |
| <div class="table"> |
| <a name="id822269"></a><p class="title"><b>Table 3. Buffer-oriented asynchronous read stream requirements</b></p> |
| <div class="table-contents"><table class="table" summary="Buffer-oriented asynchronous read 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">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_read_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_read_some</span><span class="special">(</span><span class="identifier">mb</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 read one or more bytes of |
| data from 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">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 mutable buffer |
| sequence <code class="computeroutput"><span class="identifier">mb</span></code> specifies |
| memory where the data should be placed. The <code class="computeroutput"><span class="identifier">async_read_some</span></code> |
| operation shall always fill 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">mb</span></code> |
| until such time as the read 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">mb</span></code> is destroyed, |
| or<br> <br> — the handler for the asynchronous read 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">mb</span></code> |
| is <code class="computeroutput"><span class="number">0</span></code>, the asynchronous |
| read 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 read. |
| </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 - 2010 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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| </div></td> |
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