<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Chapter 18. Boost.Signals2</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="The Boost C++ Libraries BoostBook Documentation Subset"> <link rel="up" href="libraries.html" title="Part I. The Boost C++ Libraries (BoostBook Subset)"> <link rel="prev" href="signals/tests.html" title="Testsuite"> <link rel="next" href="signals2/tutorial.html" title="Tutorial"> </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="signals/tests.html"><img src="../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="libraries.html"><img src="../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="signals2/tutorial.html"><img src="../../doc/html/images/next.png" alt="Next"></a> </div> <div class="chapter" title="Chapter 18. Boost.Signals2"> <div class="titlepage"><div> <div><h2 class="title"> <a name="signals2"></a>Chapter 18. Boost.Signals2</h2></div> <div><div class="author"><h3 class="author"> <span class="firstname">Douglas</span> <span class="surname">Gregor</span> </h3></div></div> <div><div class="author"><h3 class="author"> <span class="firstname">Frank</span> <span class="othername">Mori</span> <span class="surname">Hess</span> </h3></div></div> <div><p class="copyright">Copyright © 2001-2004 Douglas Gregor</p></div> <div><p class="copyright">Copyright © 2007-2009 Frank Mori Hess</p></div> <div><div class="legalnotice" title="Legal Notice"> <a name="id1696781"></a><p>Distributed under the Boost Software License, Version 1.0. (See accompanying file <code class="filename">LICENSE_1_0.txt</code> 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></div> </div></div> <div class="toc"> <p><b>Table of Contents</b></p> <dl> <dt><span class="section"><a href="signals2.html#id1696805">Introduction</a></span></dt> <dd><dl><dt><span class="section"><a href="signals2.html#id1696842">Signals2</a></span></dt></dl></dd> <dt><span class="section"><a href="signals2/tutorial.html">Tutorial</a></span></dt> <dd><dl> <dt><span class="section"><a href="signals2/tutorial.html#id1696875">How to Read this Tutorial</a></span></dt> <dt><span class="section"><a href="signals2/tutorial.html#id1696938">Hello, World! (Beginner)</a></span></dt> <dt><span class="section"><a href="signals2/tutorial.html#id1697004">Calling Multiple Slots</a></span></dt> <dt><span class="section"><a href="signals2/tutorial.html#id1697265">Passing Values to and from Slots</a></span></dt> <dt><span class="section"><a href="signals2/tutorial.html#id1697688">Connection Management</a></span></dt> <dt><span class="section"><a href="signals2/tutorial.html#signals2.tutorial.document-view">Example: Document-View</a></span></dt> <dt><span class="section"><a href="signals2/tutorial.html#signals2.tutorial.extended-slot-type">Giving a Slot Access to its Connection (Advanced)</a></span></dt> <dt><span class="section"><a href="signals2/tutorial.html#signals2.tutorial.signal-mutex-template-parameter">Changing the <code class="computeroutput">Mutex</code> Type of a Signal (Advanced).</a></span></dt> <dt><span class="section"><a href="signals2/tutorial.html#id1698975">Linking against the Signals2 library</a></span></dt> </dl></dd> <dt><span class="section"><a href="signals2/examples.html">Example programs</a></span></dt> <dd><dl> <dt><span class="section"><a href="signals2/examples.html#signals2.examples.misc">Miscellaneous Tutorial Examples</a></span></dt> <dt><span class="section"><a href="signals2/examples.html#signals2.examples.document-view">Document-View</a></span></dt> <dt><span class="section"><a href="signals2/examples.html#signals2.examples.deconstruct">Postconstructors and Predestructors with <code class="computeroutput">deconstruct()</code></a></span></dt> </dl></dd> <dt><span class="section"><a href="signals2/reference.html">Reference</a></span></dt> <dd><dl> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2_hpp">Header <boost/signals2.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.connection_hpp">Header <boost/signals2/connection.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.deconstruct_hpp">Header <boost/signals2/deconstruct.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.dummy_mutex_hpp">Header <boost/signals2/dummy_mutex.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.last_value_hpp">Header <boost/signals2/last_value.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.mutex_hpp">Header <boost/signals2/mutex.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.optional_last_value_hpp">Header <boost/signals2/optional_last_value.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.shared_connection_block_hpp">Header <boost/signals2/shared_connection_block.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.signal_hpp">Header <boost/signals2/signal.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.signal_base_hpp">Header <boost/signals2/signal_base.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.signal_type_hpp">Header <boost/signals2/signal_type.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.slot_hpp">Header <boost/signals2/slot.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.slot_base_hpp">Header <boost/signals2/slot_base.hpp></a></span></dt> <dt><span class="section"><a href="signals2/reference.html#header.boost.signals2.trackable_hpp">Header <boost/signals2/trackable.hpp></a></span></dt> </dl></dd> <dt><span class="section"><a href="signals2/thread-safety.html">Thread-Safety</a></span></dt> <dd><dl> <dt><span class="section"><a href="signals2/thread-safety.html#id1712881">Introduction</a></span></dt> <dt><span class="section"><a href="signals2/thread-safety.html#id1712932">Signals and combiners</a></span></dt> <dt><span class="section"><a href="signals2/thread-safety.html#id1713096">Connections and other classes</a></span></dt> </dl></dd> <dt><span class="section"><a href="signals2/faq.html">Frequently Asked Questions</a></span></dt> <dt><span class="section"><a href="signals2/rationale.html">Design Rationale</a></span></dt> <dd><dl> <dt><span class="section"><a href="signals2/rationale.html#id1713431">User-level Connection Management</a></span></dt> <dt><span class="section"><a href="signals2/rationale.html#id1713604">Automatic Connection Management</a></span></dt> <dt><span class="section"><a href="signals2/rationale.html#id1713763"><code class="computeroutput">optional_last_value</code> as the Default Combiner</a></span></dt> <dt><span class="section"><a href="signals2/rationale.html#id1713823">Combiner Interface</a></span></dt> <dt><span class="section"><a href="signals2/rationale.html#id1713904">Connection Interfaces: += operator</a></span></dt> <dt><span class="section"><a href="signals2/rationale.html#id1714076">Signals2 Mutex Classes</a></span></dt> <dt><span class="section"><a href="signals2/rationale.html#id1714170">Comparison with other Signal/Slot implementations</a></span></dt> </dl></dd> <dt><span class="section"><a href="signals2/api_changes.html">Signals2 API Changes</a></span></dt> <dd><dl> <dt><span class="section"><a href="signals2/api_changes.html#signals2.porting">Porting from Boost.Signals to Boost.Signals2</a></span></dt> <dt><span class="section"><a href="signals2/api_changes.html#signals2.api_history">Signals2 API Development</a></span></dt> </dl></dd> <dt><span class="section"><a href="signals2/tests.html">Testsuite</a></span></dt> <dd><dl><dt><span class="section"><a href="signals2/tests.html#id1715417">Acceptance tests</a></span></dt></dl></dd> </dl> </div> <div class="section" title="Introduction"> <div class="titlepage"><div><div><h2 class="title" style="clear: both"> <a name="id1696805"></a>Introduction</h2></div></div></div> <div class="toc"><dl><dt><span class="section"><a href="signals2.html#id1696842">Signals2</a></span></dt></dl></div> <p>The Boost.Signals2 library is an implementation of a managed signals and slots system. Signals represent callbacks with multiple targets, and are also called publishers or events in similar systems. Signals are connected to some set of slots, which are callback receivers (also called event targets or subscribers), which are called when the signal is "emitted."</p> <p>Signals and slots are managed, in that signals and slots (or, more properly, objects that occur as part of the slots) can track connections and are capable of automatically disconnecting signal/slot connections when either is destroyed. This enables the user to make signal/slot connections without expending a great effort to manage the lifetimes of those connections with regard to the lifetimes of all objects involved.</p> <p>When signals are connected to multiple slots, there is a question regarding the relationship between the return values of the slots and the return value of the signals. Boost.Signals2 allows the user to specify the manner in which multiple return values are combined.</p> <div class="section" title="Signals2"> <div class="titlepage"><div><div><h3 class="title"> <a name="id1696842"></a>Signals2</h3></div></div></div> <p>This documentation describes a thread-safe variant of the original Boost.Signals library. There have been some changes to the interface to support thread-safety, mostly with respect to automatic connection management. This implementation was written by Frank Mori Hess. Acknowledgements are also due to Timmo Stange, Peter Dimov, and Gottlob Frege for ideas and feedback, and to Douglas Gregor for the original version of Boost.Signals this effort was based on. </p> </div> </div> </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"><p><small>Last revised: June 12, 2007 at 14:01:23 -0400</small></p></td> <td align="right"><div class="copyright-footer"></div></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="signals/tests.html"><img src="../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="libraries.html"><img src="../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="signals2/tutorial.html"><img src="../../doc/html/images/next.png" alt="Next"></a> </div> </body> </html>