1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>basic_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="basic_serial_port__rebind_executor/other.html" title="basic_serial_port::rebind_executor::other"> 10<link rel="next" href="basic_signal_set/add.html" title="basic_signal_set::add"> 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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30 Provides signal functionality. 31 </p> 32<pre class="programlisting">template< 33 typename <a class="link" href="Executor1.html" title="Executor requirements">Executor</a> = any_io_executor> 34class basic_signal_set 35</pre> 36<h5> 37<a name="boost_asio.reference.basic_signal_set.h0"></a> 38 <span class="phrase"><a name="boost_asio.reference.basic_signal_set.types"></a></span><a class="link" href="basic_signal_set.html#boost_asio.reference.basic_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.basic_signal_set.h1"></a> 86 <span class="phrase"><a name="boost_asio.reference.basic_signal_set.member_functions"></a></span><a class="link" href="basic_signal_set.html#boost_asio.reference.basic_signal_set.member_functions">Member Functions</a> 87 </h5> 88<div class="informaltable"><table class="table"> 89<colgroup> 90<col> 91<col> 92</colgroup> 93<thead><tr> 94<th> 95 <p> 96 Name 97 </p> 98 </th> 99<th> 100 <p> 101 Description 102 </p> 103 </th> 104</tr></thead> 105<tbody> 106<tr> 107<td> 108 <p> 109 <a class="link" href="basic_signal_set/add.html" title="basic_signal_set::add"><span class="bold"><strong>add</strong></span></a> 110 </p> 111 </td> 112<td> 113 <p> 114 Add a signal to a signal_set. 115 </p> 116 </td> 117</tr> 118<tr> 119<td> 120 <p> 121 <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> 122 </p> 123 </td> 124<td> 125 <p> 126 Start an asynchronous operation to wait for a signal to be delivered. 127 </p> 128 </td> 129</tr> 130<tr> 131<td> 132 <p> 133 <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> 134 </p> 135 </td> 136<td> 137 <p> 138 Construct a signal set without adding any signals. <br> <span class="silver"> —</span><br> 139 Construct a signal set and add one signal. <br> <span class="silver"> —</span><br> Construct 140 a signal set and add two signals. <br> <span class="silver"> —</span><br> Construct a signal 141 set and add three signals. 142 </p> 143 </td> 144</tr> 145<tr> 146<td> 147 <p> 148 <a class="link" href="basic_signal_set/cancel.html" title="basic_signal_set::cancel"><span class="bold"><strong>cancel</strong></span></a> 149 </p> 150 </td> 151<td> 152 <p> 153 Cancel all operations associated with the signal set. 154 </p> 155 </td> 156</tr> 157<tr> 158<td> 159 <p> 160 <a class="link" href="basic_signal_set/clear.html" title="basic_signal_set::clear"><span class="bold"><strong>clear</strong></span></a> 161 </p> 162 </td> 163<td> 164 <p> 165 Remove all signals from a signal_set. 166 </p> 167 </td> 168</tr> 169<tr> 170<td> 171 <p> 172 <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> 173 </p> 174 </td> 175<td> 176 <p> 177 Get the executor associated with the object. 178 </p> 179 </td> 180</tr> 181<tr> 182<td> 183 <p> 184 <a class="link" href="basic_signal_set/remove.html" title="basic_signal_set::remove"><span class="bold"><strong>remove</strong></span></a> 185 </p> 186 </td> 187<td> 188 <p> 189 Remove a signal from a signal_set. 190 </p> 191 </td> 192</tr> 193<tr> 194<td> 195 <p> 196 <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> 197 </p> 198 </td> 199<td> 200 <p> 201 Destroys the signal set. 202 </p> 203 </td> 204</tr> 205</tbody> 206</table></div> 207<p> 208 The <a class="link" href="basic_signal_set.html" title="basic_signal_set"><code class="computeroutput">basic_signal_set</code></a> 209 class provides the ability to perform an asynchronous wait for one or more 210 signals to occur. 211 </p> 212<h5> 213<a name="boost_asio.reference.basic_signal_set.h2"></a> 214 <span class="phrase"><a name="boost_asio.reference.basic_signal_set.thread_safety"></a></span><a class="link" href="basic_signal_set.html#boost_asio.reference.basic_signal_set.thread_safety">Thread 215 Safety</a> 216 </h5> 217<p> 218 <span class="emphasis"><em>Distinct</em></span> <span class="emphasis"><em>objects:</em></span> Safe. 219 </p> 220<p> 221 <span class="emphasis"><em>Shared</em></span> <span class="emphasis"><em>objects:</em></span> Unsafe. 222 </p> 223<h5> 224<a name="boost_asio.reference.basic_signal_set.h3"></a> 225 <span class="phrase"><a name="boost_asio.reference.basic_signal_set.example"></a></span><a class="link" href="basic_signal_set.html#boost_asio.reference.basic_signal_set.example">Example</a> 226 </h5> 227<p> 228 Performing an asynchronous wait: 229 </p> 230<pre class="programlisting">void handler( 231 const boost::system::error_code& error, 232 int signal_number) 233{ 234 if (!error) 235 { 236 // A signal occurred. 237 } 238} 239 240... 241 242// Construct a signal set registered for process termination. 243boost::asio::signal_set signals(my_context, SIGINT, SIGTERM); 244 245// Start an asynchronous wait for one of the signals to occur. 246signals.async_wait(handler); 247</pre> 248<h5> 249<a name="boost_asio.reference.basic_signal_set.h4"></a> 250 <span class="phrase"><a name="boost_asio.reference.basic_signal_set.queueing_of_signal_notifications"></a></span><a class="link" href="basic_signal_set.html#boost_asio.reference.basic_signal_set.queueing_of_signal_notifications">Queueing 251 of signal notifications</a> 252 </h5> 253<p> 254 If a signal is registered with a signal_set, and the signal occurs when there 255 are no waiting handlers, then the signal notification is queued. The next 256 async_wait operation on that signal_set will dequeue the notification. If 257 multiple notifications are queued, subsequent async_wait operations dequeue 258 them one at a time. Signal notifications are dequeued in order of ascending 259 signal number. 260 </p> 261<p> 262 If a signal number is removed from a signal_set (using the <code class="computeroutput">remove</code> 263 or <code class="computeroutput">erase</code> member functions) then any queued notifications for 264 that signal are discarded. 265 </p> 266<h5> 267<a name="boost_asio.reference.basic_signal_set.h5"></a> 268 <span class="phrase"><a name="boost_asio.reference.basic_signal_set.multiple_registration_of_signals"></a></span><a class="link" href="basic_signal_set.html#boost_asio.reference.basic_signal_set.multiple_registration_of_signals">Multiple 269 registration of signals</a> 270 </h5> 271<p> 272 The same signal number may be registered with different signal_set objects. 273 When the signal occurs, one handler is called for each signal_set object. 274 </p> 275<p> 276 Note that multiple registration only works for signals that are registered 277 using Asio. The application must not also register a signal handler using 278 functions such as <code class="computeroutput">signal()</code> or <code class="computeroutput">sigaction()</code>. 279 </p> 280<h5> 281<a name="boost_asio.reference.basic_signal_set.h6"></a> 282 <span class="phrase"><a name="boost_asio.reference.basic_signal_set.signal_masking_on_posix_platforms"></a></span><a class="link" href="basic_signal_set.html#boost_asio.reference.basic_signal_set.signal_masking_on_posix_platforms">Signal 283 masking on POSIX platforms</a> 284 </h5> 285<p> 286 POSIX allows signals to be blocked using functions such as <code class="computeroutput">sigprocmask()</code> 287 and <code class="computeroutput">pthread_sigmask()</code>. For signals to be delivered, programs 288 must ensure that any signals registered using signal_set objects are unblocked 289 in at least one thread. 290 </p> 291<h5> 292<a name="boost_asio.reference.basic_signal_set.h7"></a> 293 <span class="phrase"><a name="boost_asio.reference.basic_signal_set.requirements"></a></span><a class="link" href="basic_signal_set.html#boost_asio.reference.basic_signal_set.requirements">Requirements</a> 294 </h5> 295<p> 296 <span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/basic_signal_set.hpp</code> 297 </p> 298<p> 299 <span class="emphasis"><em>Convenience header: </em></span><code class="literal">boost/asio.hpp</code> 300 </p> 301</div> 302<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 303<td align="left"></td> 304<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 305 Kohlhoff<p> 306 Distributed under the Boost Software License, Version 1.0. (See accompanying 307 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>) 308 </p> 309</div></td> 310</tr></table> 311<hr> 312<div class="spirit-nav"> 313<a accesskey="p" href="basic_serial_port__rebind_executor/other.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="basic_signal_set/add.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 314</div> 315</body> 316</html> 317
