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
|
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>thread_pool::notify_fork</title>
<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="../../../boost_asio.html" title="Boost.Asio">
<link rel="up" href="../thread_pool.html" title="thread_pool">
<link rel="prev" href="make_service.html" title="thread_pool::make_service">
<link rel="next" href="shutdown.html" title="thread_pool::shutdown">
</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="make_service.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../thread_pool.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="shutdown.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.reference.thread_pool.notify_fork"></a><a class="link" href="notify_fork.html" title="thread_pool::notify_fork">thread_pool::notify_fork</a>
</h4></div></div></div>
<p>
<span class="emphasis"><em>Inherited from execution_context.</em></span>
</p>
<p>
<a class="indexterm" name="boost_asio.indexterm.thread_pool.notify_fork"></a>
Notify
the <a class="link" href="../execution_context.html" title="execution_context"><code class="computeroutput">execution_context</code></a>
of a fork-related event.
</p>
<pre class="programlisting">void notify_fork(
fork_event event);
</pre>
<p>
This function is used to inform the <a class="link" href="../execution_context.html" title="execution_context"><code class="computeroutput">execution_context</code></a>
that the process is about to fork, or has just forked. This allows the
<a class="link" href="../execution_context.html" title="execution_context"><code class="computeroutput">execution_context</code></a>,
and the services it contains, to perform any necessary housekeeping to
ensure correct operation following a fork.
</p>
<p>
This function must not be called while any other <a class="link" href="../execution_context.html" title="execution_context"><code class="computeroutput">execution_context</code></a>
function, or any function associated with the execution_context's derived
class, is being called in another thread. It is, however, safe to call
this function from within a completion handler, provided no other thread
is accessing the <a class="link" href="../execution_context.html" title="execution_context"><code class="computeroutput">execution_context</code></a>
or its derived class.
</p>
<h6>
<a name="boost_asio.reference.thread_pool.notify_fork.h0"></a>
<span class="phrase"><a name="boost_asio.reference.thread_pool.notify_fork.parameters"></a></span><a class="link" href="notify_fork.html#boost_asio.reference.thread_pool.notify_fork.parameters">Parameters</a>
</h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl class="variablelist">
<dt><span class="term">event</span></dt>
<dd><p>
A fork-related event.
</p></dd>
</dl>
</div>
<h6>
<a name="boost_asio.reference.thread_pool.notify_fork.h1"></a>
<span class="phrase"><a name="boost_asio.reference.thread_pool.notify_fork.exceptions"></a></span><a class="link" href="notify_fork.html#boost_asio.reference.thread_pool.notify_fork.exceptions">Exceptions</a>
</h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl class="variablelist">
<dt><span class="term">boost::system::system_error</span></dt>
<dd><p>
Thrown on failure. If the notification fails the <a class="link" href="../execution_context.html" title="execution_context"><code class="computeroutput">execution_context</code></a>
object should no longer be used and should be destroyed.
</p></dd>
</dl>
</div>
<h6>
<a name="boost_asio.reference.thread_pool.notify_fork.h2"></a>
<span class="phrase"><a name="boost_asio.reference.thread_pool.notify_fork.example"></a></span><a class="link" href="notify_fork.html#boost_asio.reference.thread_pool.notify_fork.example">Example</a>
</h6>
<p>
The following code illustrates how to incorporate the <code class="computeroutput">notify_fork()</code>
function:
</p>
<pre class="programlisting">my_execution_context.notify_fork(execution_context::fork_prepare);
if (fork() == 0)
{
// This is the child process.
my_execution_context.notify_fork(execution_context::fork_child);
}
else
{
// This is the parent process.
my_execution_context.notify_fork(execution_context::fork_parent);
}
</pre>
<h6>
<a name="boost_asio.reference.thread_pool.notify_fork.h3"></a>
<span class="phrase"><a name="boost_asio.reference.thread_pool.notify_fork.remarks"></a></span><a class="link" href="notify_fork.html#boost_asio.reference.thread_pool.notify_fork.remarks">Remarks</a>
</h6>
<p>
For each service object <code class="computeroutput">svc</code> in the <a class="link" href="../execution_context.html" title="execution_context"><code class="computeroutput">execution_context</code></a>
set, performs <code class="computeroutput">svc->notify_fork();</code>. When processing the
fork_prepare event, services are visited in reverse order of the beginning
of service object lifetime. Otherwise, services are visited in order of
the beginning of service object lifetime.
</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 © 2003-2017 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="make_service.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../thread_pool.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="shutdown.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>
|
