ceph/src/boost/libs/signals2/doc/introduction.xml

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   2 <!DOCTYPE section PUBLIC "-//Boost//DTD BoostBook XML V1.0//EN"
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   4 <!--
   5 Copyright Douglas Gregor 2001-2004
   6 Copyright Frank Mori Hess 2007-2009
   7
   8 Distributed under the Boost Software License, Version 1.0. (See accompanying
   9 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  10 -->
  11 <section last-revision="$Date: 2007-06-12 14:01:23 -0400 (Tue, 12 Jun 2007) $">
  12   <title>Introduction</title>
  13
  14   <para>The Boost.Signals2 library is an implementation of a managed
  15   signals and slots system. Signals represent callbacks with multiple
  16   targets, and are also called publishers or events in similar
  17   systems. Signals are connected to some set of slots, which are
  18   callback receivers (also called event targets or subscribers), which
  19   are called when the signal is "emitted."</para>
  20
  21   <para>Signals and slots are managed, in that signals and slots (or,
  22   more properly, objects that occur as part of the slots) can track
  23   connections and are capable of automatically disconnecting signal/slot
  24   connections when either is destroyed. This enables the user to make
  25   signal/slot connections without expending a great effort to manage the
  26   lifetimes of those connections with regard to the lifetimes of all
  27   objects involved.</para>
  28
  29   <para>When signals are connected to multiple slots, there is a
  30   question regarding the relationship between the return values of the
  31   slots and the return value of the signals. Boost.Signals2 allows the
  32   user to specify the manner in which multiple return values are
  33   combined.</para>
  34
  35   <section>
  36     <title>Signals2</title>
  37     <para>This documentation describes a thread-safe variant of the
  38     original Boost.Signals library.  There have been some changes to
  39     the interface to support thread-safety, mostly with respect to
  40     automatic connection management.  This implementation was written by
  41     Frank Mori Hess.  Acknowledgements are also due to Timmo Stange, Peter
  42     Dimov, and Tony Van Eerd for ideas and feedback, and to Douglas Gregor
  43     for the original version of Boost.Signals this effort was based on.
  44     </para>
  45   </section>
  46 </section>