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Junxiao Shi8d71fdb2014-12-07 21:55:19 -07001/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
Junxiao Shi5722cfe2017-07-05 18:52:01 +00002/*
3 * Copyright (c) 2013-2017 Regents of the University of California.
Junxiao Shi8d71fdb2014-12-07 21:55:19 -07004 *
5 * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
6 *
7 * ndn-cxx library is free software: you can redistribute it and/or modify it under the
8 * terms of the GNU Lesser General Public License as published by the Free Software
9 * Foundation, either version 3 of the License, or (at your option) any later version.
10 *
11 * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
12 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
14 *
15 * You should have received copies of the GNU General Public License and GNU Lesser
16 * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
17 * <http://www.gnu.org/licenses/>.
18 *
19 * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
20 */
21
22#ifndef NDN_UTIL_SIGNAL_CONNECTION_HPP
23#define NDN_UTIL_SIGNAL_CONNECTION_HPP
24
Junxiao Shi5722cfe2017-07-05 18:52:01 +000025#include "../../common.hpp"
Junxiao Shi8d71fdb2014-12-07 21:55:19 -070026
27namespace ndn {
28namespace util {
29namespace signal {
30
31/** \brief represents a connection to a signal
32 * \note This type is copyable. Any copy can be used to disconnect.
33 */
34class Connection
35{
36public:
37 Connection();
38
39 /** \brief disconnects from the signal
40 * \note If the connection is already disconnected, or if the Signal has been destructed,
41 * this operation has no effect.
42 * \warning During signal emission, attempting to disconnect a connection other than
43 * the executing handler's own connection results in undefined behavior.
44 */
45 void
46 disconnect();
47
Chengyu Fanf46482c2015-02-03 16:55:53 -070048 /** \brief check if connected to the signal
49 * \return false if disconnected from the signal
50 */
51 bool
52 isConnected() const;
53
Junxiao Shi8d71fdb2014-12-07 21:55:19 -070054 /** \brief compare for equality
55 *
56 * Two connections are equal if they both refer to the same connection that isn't disconnected,
57 * or they are both disconnected.
58 */
59 bool
60 operator==(const Connection& other) const;
61
62 bool
63 operator!=(const Connection& other) const;
64
65private:
66 /** \param disconnect weak_ptr to a function that disconnects the handler
67 */
68 explicit
69 Connection(weak_ptr<function<void()>> disconnect);
70
71 template<typename Owner, typename ...TArgs>
72 friend class Signal;
73
74private:
75 /** \note The only shared_ptr to the disconnect function is stored in Signal<..>::Slot,
76 * and will be destructed if the handler is disconnected (through another Connection
77 * instance) or the Signal is destructed.
78 * Connection needs a weak_ptr instead of a shared_ptr to the disconnect function,
79 * because the disconnect function is bound with an iterator to the Slot,
80 * which is invalidated when the Slot is erased.
81 */
82 weak_ptr<function<void()>> m_disconnect;
83};
84
85} // namespace signal
86} // namespace util
87} // namespace ndn
88
89#endif // NDN_UTIL_SIGNAL_CONNECTION_HPP