AsyncRandomAccessWriteDevice.html
6.54 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Buffer-oriented asynchronous random-access write device requirements</title>
<link rel="stylesheet" href="../../boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="../../index.html" title="Asio">
<link rel="up" href="../reference.html" title="Reference">
<link rel="prev" href="AsyncRandomAccessReadDevice.html" title="Buffer-oriented asynchronous random-access read device requirements">
<link rel="next" href="AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="asio C++ library" width="250" height="60" src="../../asio.png"></td></tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="AsyncRandomAccessReadDevice.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../home.png" alt="Home"></a><a accesskey="n" href="AsyncReadStream.html"><img src="../../next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="asio.reference.AsyncRandomAccessWriteDevice"></a><a class="link" href="AsyncRandomAccessWriteDevice.html" title="Buffer-oriented asynchronous random-access write device requirements">Buffer-oriented
asynchronous random-access write device requirements</a>
</h3></div></div></div>
<p>
In the table below, <code class="computeroutput">a</code> denotes an asynchronous write stream object,
<code class="computeroutput">o</code> denotes an offset of type <code class="computeroutput">boost::uint64_t</code>, <code class="computeroutput">cb</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">h</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="asio.reference.AsyncRandomAccessWriteDevice.t0"></a><p class="title"><b>Table 3. Buffer-oriented asynchronous random-access write device requirements</b></p>
<div class="table-contents"><table class="table" summary="Buffer-oriented asynchronous random-access write device 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">a.get_executor()</code>
</p>
</td>
<td>
<p>
A type satisfying the <a class="link" href="Executor1.html" title="Executor requirements">Executor
requirements</a>.
</p>
</td>
<td>
<p>
Returns the associated I/O executor.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput">a.async_write_some_at(o, cb, h);</code>
</p>
</td>
<td>
<p>
<code class="computeroutput">void</code>
</p>
</td>
<td>
<p>
Initiates an asynchronous operation to write one or more bytes
of data to the device <code class="computeroutput">a</code> at offset <code class="computeroutput">o</code>.
The operation is performed via the <code class="computeroutput">io_service</code> object
<code class="computeroutput">a.get_io_service()</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">cb</code>
specifies memory where the data to be written is located. The
<code class="computeroutput">async_write_some_at</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">cb</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">cb</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">cb</code> is <code class="computeroutput">0</code>,
the asynchronous write operation shall complete immediately and
pass <code class="computeroutput">0</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 © 2003-2020 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="AsyncRandomAccessReadDevice.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../home.png" alt="Home"></a><a accesskey="n" href="AsyncReadStream.html"><img src="../../next.png" alt="Next"></a>
</div>
</body>
</html>