1 | // Boost.Signals2 library |
---|---|
2 | |
3 | // Copyright Frank Mori Hess 2007-2008. |
4 | // Use, modification and |
5 | // distribution is subject to the Boost Software License, Version |
6 | // 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
7 | // http://www.boost.org/LICENSE_1_0.txt) |
8 | |
9 | // For more information, see http://www.boost.org |
10 | |
11 | #ifndef BOOST_SIGNALS2_SHARED_CONNECTION_BLOCK_HPP |
12 | #define BOOST_SIGNALS2_SHARED_CONNECTION_BLOCK_HPP |
13 | |
14 | #include <boost/shared_ptr.hpp> |
15 | #include <boost/signals2/connection.hpp> |
16 | #include <boost/weak_ptr.hpp> |
17 | |
18 | namespace boost |
19 | { |
20 | namespace signals2 |
21 | { |
22 | class shared_connection_block |
23 | { |
24 | public: |
25 | shared_connection_block(const signals2::connection &conn = signals2::connection(), |
26 | bool initially_blocked = true): |
27 | _weak_connection_body(conn._weak_connection_body) |
28 | { |
29 | if(initially_blocked) block(); |
30 | } |
31 | void block() |
32 | { |
33 | if(blocking()) return; |
34 | boost::shared_ptr<detail::connection_body_base> connection_body(_weak_connection_body.lock()); |
35 | if(connection_body == 0) |
36 | { |
37 | // Make _blocker non-empty so the blocking() method still returns the correct value |
38 | // after the connection has expired. |
39 | _blocker.reset(p: static_cast<int*>(0)); |
40 | return; |
41 | } |
42 | _blocker = connection_body->get_blocker(); |
43 | } |
44 | void unblock() |
45 | { |
46 | _blocker.reset(); |
47 | } |
48 | bool blocking() const |
49 | { |
50 | shared_ptr<void> empty; |
51 | return _blocker < empty || empty < _blocker; |
52 | } |
53 | signals2::connection connection() const |
54 | { |
55 | return signals2::connection(_weak_connection_body); |
56 | } |
57 | private: |
58 | boost::weak_ptr<detail::connection_body_base> _weak_connection_body; |
59 | shared_ptr<void> _blocker; |
60 | }; |
61 | } |
62 | } // end namespace boost |
63 | |
64 | #endif // BOOST_SIGNALS2_SHARED_CONNECTION_BLOCK_HPP |
65 |