1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>signal_set</title> 5<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../boost_asio.html" title="Boost.Asio"> 8<link rel="up" href="../reference.html" title="Reference"> 9<link rel="prev" href="service_already_exists/service_already_exists.html" title="service_already_exists::service_already_exists"> 10<link rel="next" href="socket_base.html" title="socket_base"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> 15<td align="center"><a href="../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> 17<td 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name="boost_asio.indexterm.signal_set"></a> 31Typedef for the typical usage of 32 a signal set. 33 </p> 34<pre class="programlisting">typedef basic_signal_set signal_set; 35</pre> 36<h5> 37<a name="boost_asio.reference.signal_set.h0"></a> 38 <span class="phrase"><a name="boost_asio.reference.signal_set.types"></a></span><a class="link" href="signal_set.html#boost_asio.reference.signal_set.types">Types</a> 39 </h5> 40<div class="informaltable"><table class="table"> 41<colgroup> 42<col> 43<col> 44</colgroup> 45<thead><tr> 46<th> 47 <p> 48 Name 49 </p> 50 </th> 51<th> 52 <p> 53 Description 54 </p> 55 </th> 56</tr></thead> 57<tbody> 58<tr> 59<td> 60 <p> 61 <a class="link" href="basic_signal_set__rebind_executor.html" title="basic_signal_set::rebind_executor"><span class="bold"><strong>rebind_executor</strong></span></a> 62 </p> 63 </td> 64<td> 65 <p> 66 Rebinds the signal set type to another executor. 67 </p> 68 </td> 69</tr> 70<tr> 71<td> 72 <p> 73 <a class="link" href="basic_signal_set/executor_type.html" title="basic_signal_set::executor_type"><span class="bold"><strong>executor_type</strong></span></a> 74 </p> 75 </td> 76<td> 77 <p> 78 The type of the executor associated with the object. 79 </p> 80 </td> 81</tr> 82</tbody> 83</table></div> 84<h5> 85<a name="boost_asio.reference.signal_set.h1"></a> 86 <span class="phrase"><a name="boost_asio.reference.signal_set.member_functions"></a></span><a class="link" href="signal_set.html#boost_asio.reference.signal_set.member_functions">Member 87 Functions</a> 88 </h5> 89<div class="informaltable"><table class="table"> 90<colgroup> 91<col> 92<col> 93</colgroup> 94<thead><tr> 95<th> 96 <p> 97 Name 98 </p> 99 </th> 100<th> 101 <p> 102 Description 103 </p> 104 </th> 105</tr></thead> 106<tbody> 107<tr> 108<td> 109 <p> 110 <a class="link" href="basic_signal_set/add.html" title="basic_signal_set::add"><span class="bold"><strong>add</strong></span></a> 111 </p> 112 </td> 113<td> 114 <p> 115 Add a signal to a signal_set. 116 </p> 117 </td> 118</tr> 119<tr> 120<td> 121 <p> 122 <a class="link" href="basic_signal_set/async_wait.html" title="basic_signal_set::async_wait"><span class="bold"><strong>async_wait</strong></span></a> 123 </p> 124 </td> 125<td> 126 <p> 127 Start an asynchronous operation to wait for a signal to be delivered. 128 </p> 129 </td> 130</tr> 131<tr> 132<td> 133 <p> 134 <a class="link" href="basic_signal_set/basic_signal_set.html" title="basic_signal_set::basic_signal_set"><span class="bold"><strong>basic_signal_set</strong></span></a> <span class="silver">[constructor]</span> 135 </p> 136 </td> 137<td> 138 <p> 139 Construct a signal set without adding any signals. <br> <span class="silver"> —</span><br> 140 Construct a signal set and add one signal. <br> <span class="silver"> —</span><br> Construct 141 a signal set and add two signals. <br> <span class="silver"> —</span><br> Construct a signal 142 set and add three signals. 143 </p> 144 </td> 145</tr> 146<tr> 147<td> 148 <p> 149 <a class="link" href="basic_signal_set/cancel.html" title="basic_signal_set::cancel"><span class="bold"><strong>cancel</strong></span></a> 150 </p> 151 </td> 152<td> 153 <p> 154 Cancel all operations associated with the signal set. 155 </p> 156 </td> 157</tr> 158<tr> 159<td> 160 <p> 161 <a class="link" href="basic_signal_set/clear.html" title="basic_signal_set::clear"><span class="bold"><strong>clear</strong></span></a> 162 </p> 163 </td> 164<td> 165 <p> 166 Remove all signals from a signal_set. 167 </p> 168 </td> 169</tr> 170<tr> 171<td> 172 <p> 173 <a class="link" href="basic_signal_set/get_executor.html" title="basic_signal_set::get_executor"><span class="bold"><strong>get_executor</strong></span></a> 174 </p> 175 </td> 176<td> 177 <p> 178 Get the executor associated with the object. 179 </p> 180 </td> 181</tr> 182<tr> 183<td> 184 <p> 185 <a class="link" href="basic_signal_set/remove.html" title="basic_signal_set::remove"><span class="bold"><strong>remove</strong></span></a> 186 </p> 187 </td> 188<td> 189 <p> 190 Remove a signal from a signal_set. 191 </p> 192 </td> 193</tr> 194<tr> 195<td> 196 <p> 197 <a class="link" href="basic_signal_set/_basic_signal_set.html" title="basic_signal_set::~basic_signal_set"><span class="bold"><strong>~basic_signal_set</strong></span></a> <span class="silver">[destructor]</span> 198 </p> 199 </td> 200<td> 201 <p> 202 Destroys the signal set. 203 </p> 204 </td> 205</tr> 206</tbody> 207</table></div> 208<p> 209 The <a class="link" href="basic_signal_set.html" title="basic_signal_set"><code class="computeroutput">basic_signal_set</code></a> 210 class provides the ability to perform an asynchronous wait for one or more 211 signals to occur. 212 </p> 213<h5> 214<a name="boost_asio.reference.signal_set.h2"></a> 215 <span class="phrase"><a name="boost_asio.reference.signal_set.thread_safety"></a></span><a class="link" href="signal_set.html#boost_asio.reference.signal_set.thread_safety">Thread 216 Safety</a> 217 </h5> 218<p> 219 <span class="emphasis"><em>Distinct</em></span> <span class="emphasis"><em>objects:</em></span> Safe. 220 </p> 221<p> 222 <span class="emphasis"><em>Shared</em></span> <span class="emphasis"><em>objects:</em></span> Unsafe. 223 </p> 224<h5> 225<a name="boost_asio.reference.signal_set.h3"></a> 226 <span class="phrase"><a name="boost_asio.reference.signal_set.example"></a></span><a class="link" href="signal_set.html#boost_asio.reference.signal_set.example">Example</a> 227 </h5> 228<p> 229 Performing an asynchronous wait: 230 </p> 231<pre class="programlisting">void handler( 232 const boost::system::error_code& error, 233 int signal_number) 234{ 235 if (!error) 236 { 237 // A signal occurred. 238 } 239} 240 241... 242 243// Construct a signal set registered for process termination. 244boost::asio::signal_set signals(my_context, SIGINT, SIGTERM); 245 246// Start an asynchronous wait for one of the signals to occur. 247signals.async_wait(handler); 248</pre> 249<h5> 250<a name="boost_asio.reference.signal_set.h4"></a> 251 <span class="phrase"><a name="boost_asio.reference.signal_set.queueing_of_signal_notifications"></a></span><a class="link" href="signal_set.html#boost_asio.reference.signal_set.queueing_of_signal_notifications">Queueing 252 of signal notifications</a> 253 </h5> 254<p> 255 If a signal is registered with a signal_set, and the signal occurs when there 256 are no waiting handlers, then the signal notification is queued. The next 257 async_wait operation on that signal_set will dequeue the notification. If 258 multiple notifications are queued, subsequent async_wait operations dequeue 259 them one at a time. Signal notifications are dequeued in order of ascending 260 signal number. 261 </p> 262<p> 263 If a signal number is removed from a signal_set (using the <code class="computeroutput">remove</code> 264 or <code class="computeroutput">erase</code> member functions) then any queued notifications for 265 that signal are discarded. 266 </p> 267<h5> 268<a name="boost_asio.reference.signal_set.h5"></a> 269 <span class="phrase"><a name="boost_asio.reference.signal_set.multiple_registration_of_signals"></a></span><a class="link" href="signal_set.html#boost_asio.reference.signal_set.multiple_registration_of_signals">Multiple 270 registration of signals</a> 271 </h5> 272<p> 273 The same signal number may be registered with different signal_set objects. 274 When the signal occurs, one handler is called for each signal_set object. 275 </p> 276<p> 277 Note that multiple registration only works for signals that are registered 278 using Asio. The application must not also register a signal handler using 279 functions such as <code class="computeroutput">signal()</code> or <code class="computeroutput">sigaction()</code>. 280 </p> 281<h5> 282<a name="boost_asio.reference.signal_set.h6"></a> 283 <span class="phrase"><a name="boost_asio.reference.signal_set.signal_masking_on_posix_platforms"></a></span><a class="link" href="signal_set.html#boost_asio.reference.signal_set.signal_masking_on_posix_platforms">Signal 284 masking on POSIX platforms</a> 285 </h5> 286<p> 287 POSIX allows signals to be blocked using functions such as <code class="computeroutput">sigprocmask()</code> 288 and <code class="computeroutput">pthread_sigmask()</code>. For signals to be delivered, programs 289 must ensure that any signals registered using signal_set objects are unblocked 290 in at least one thread. 291 </p> 292<h5> 293<a name="boost_asio.reference.signal_set.h7"></a> 294 <span class="phrase"><a name="boost_asio.reference.signal_set.requirements"></a></span><a class="link" href="signal_set.html#boost_asio.reference.signal_set.requirements">Requirements</a> 295 </h5> 296<p> 297 <span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/signal_set.hpp</code> 298 </p> 299<p> 300 <span class="emphasis"><em>Convenience header: </em></span><code class="literal">boost/asio.hpp</code> 301 </p> 302</div> 303<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 304<td align="left"></td> 305<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 306 Kohlhoff<p> 307 Distributed under the Boost Software License, Version 1.0. (See accompanying 308 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>) 309 </p> 310</div></td> 311</tr></table> 312<hr> 313<div class="spirit-nav"> 314<a accesskey="p" href="service_already_exists/service_already_exists.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="socket_base.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 315</div> 316</body> 317</html> 318
