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1 | // Boost.Signals library | |
2 | ||
3 | // Copyright Douglas Gregor 2001-2004. Use, modification and | |
4 | // distribution is subject to the Boost Software License, Version | |
5 | // 1.0. (See accompanying file LICENSE_1_0.txt or copy at | |
6 | // http://www.boost.org/LICENSE_1_0.txt) | |
7 | ||
8 | // For more information, see http://www.boost.org | |
9 | ||
10 | #define BOOST_SIGNALS_SOURCE | |
11 | ||
12 | #include <boost/signals/detail/signal_base.hpp> | |
13 | #include <cassert> | |
14 | ||
15 | namespace boost { | |
16 | namespace BOOST_SIGNALS_NAMESPACE { | |
17 | namespace detail { | |
18 | signal_base_impl::signal_base_impl(const compare_type& comp, | |
19 | const any& combiner) | |
20 | : call_depth(0), | |
21 | slots_(comp), | |
22 | combiner_(combiner) | |
23 | { | |
24 | flags.delayed_disconnect = false; | |
25 | flags.clearing = false; | |
26 | } | |
27 | ||
28 | signal_base_impl::~signal_base_impl() | |
29 | { | |
30 | // Set the "clearing" flag to ignore extraneous disconnect requests, | |
31 | // because all slots will be disconnected on destruction anyway. | |
32 | flags.clearing = true; | |
33 | } | |
34 | ||
35 | void signal_base_impl::disconnect_all_slots() | |
36 | { | |
37 | // Do nothing if we're already clearing the slot list | |
38 | if (flags.clearing) | |
39 | return; | |
40 | ||
41 | if (call_depth == 0) { | |
42 | // Clearing the slot list will disconnect all slots automatically | |
43 | temporarily_set_clearing set_clearing(this); | |
44 | slots_.clear(); | |
45 | } | |
46 | else { | |
47 | // We can't actually remove elements from the slot list because there | |
48 | // are still iterators into the slot list that must not be | |
49 | // invalidated by this operation. So just disconnect each slot | |
50 | // without removing it from the slot list. When the call depth does | |
51 | // reach zero, the call list will be cleared. | |
52 | flags.delayed_disconnect = true; | |
53 | temporarily_set_clearing set_clearing(this); | |
54 | for (iterator i = slots_.begin(); i != slots_.end(); ++i) { | |
55 | i->first.disconnect(); | |
56 | } | |
57 | } | |
58 | } | |
59 | ||
60 | connection | |
61 | signal_base_impl:: | |
62 | connect_slot(const any& slot_, | |
63 | const stored_group& name, | |
64 | shared_ptr<slot_base::data_t> data, | |
65 | connect_position at) | |
66 | { | |
67 | // Transfer the burden of ownership to a local, scoped | |
68 | // connection. | |
69 | data->watch_bound_objects.set_controlling(false); | |
70 | scoped_connection safe_connection(data->watch_bound_objects); | |
71 | ||
72 | // Allocate storage for an iterator that will hold the point of | |
73 | // insertion of the slot into the list. This is used to later remove | |
74 | // the slot when it is disconnected. | |
75 | ||
76 | #if defined(BOOST_NO_CXX11_SMART_PTR) | |
77 | ||
78 | std::auto_ptr<iterator> saved_iter(new iterator); | |
79 | ||
80 | #else | |
81 | ||
82 | std::unique_ptr<iterator> saved_iter(new iterator); | |
83 | ||
84 | #endif | |
85 | ||
86 | // Add the slot to the list. | |
87 | iterator pos = | |
88 | slots_.insert(name, data->watch_bound_objects, slot_, at); | |
89 | ||
90 | // The assignment operation here absolutely must not throw, which | |
91 | // intuitively makes sense (because any container's insert method | |
92 | // becomes impossible to use in an exception-safe manner without this | |
93 | // assumption), but doesn't appear to be mentioned in the standard. | |
94 | *saved_iter = pos; | |
95 | ||
96 | // Fill out the connection object appropriately. None of these | |
97 | // operations can throw | |
98 | data->watch_bound_objects.get_connection()->signal = this; | |
99 | data->watch_bound_objects.get_connection()->signal_data = | |
100 | saved_iter.release(); | |
101 | data->watch_bound_objects.get_connection()->signal_disconnect = | |
102 | &signal_base_impl::slot_disconnected; | |
103 | ||
104 | // Make the copy of the connection in the list disconnect when it is | |
105 | // destroyed. The local, scoped connection is then released | |
106 | // because ownership has been transferred. | |
107 | pos->first.set_controlling(); | |
108 | return safe_connection.release(); | |
109 | } | |
110 | ||
111 | bool signal_base_impl::empty() const | |
112 | { | |
113 | // Disconnected slots may still be in the list of slots if | |
114 | // a) this is called while slots are being invoked (call_depth > 0) | |
115 | // b) an exception was thrown in remove_disconnected_slots | |
116 | for (iterator i = slots_.begin(); i != slots_.end(); ++i) { | |
117 | if (i->first.connected()) | |
118 | return false; | |
119 | } | |
120 | ||
121 | return true; | |
122 | } | |
123 | ||
124 | std::size_t signal_base_impl::num_slots() const | |
125 | { | |
126 | // Disconnected slots may still be in the list of slots if | |
127 | // a) this is called while slots are being invoked (call_depth > 0) | |
128 | // b) an exception was thrown in remove_disconnected_slots | |
129 | std::size_t count = 0; | |
130 | for (iterator i = slots_.begin(); i != slots_.end(); ++i) { | |
131 | if (i->first.connected()) | |
132 | ++count; | |
133 | } | |
134 | return count; | |
135 | } | |
136 | ||
137 | void signal_base_impl::disconnect(const stored_group& group) | |
138 | { slots_.disconnect(group); } | |
139 | ||
140 | void signal_base_impl::slot_disconnected(void* obj, void* data) | |
141 | { | |
142 | signal_base_impl* self = reinterpret_cast<signal_base_impl*>(obj); | |
143 | ||
144 | // We won't need the slot iterator after this | |
145 | ||
146 | #if defined(BOOST_NO_CXX11_SMART_PTR) | |
147 | ||
148 | std::auto_ptr<iterator> slot(reinterpret_cast<iterator*>(data)); | |
149 | ||
150 | #else | |
151 | ||
152 | std::unique_ptr<iterator> slot(reinterpret_cast<iterator*>(data)); | |
153 | ||
154 | #endif | |
155 | ||
156 | // If we're flags.clearing, we don't bother updating the list of slots | |
157 | if (!self->flags.clearing) { | |
158 | // If we're in a call, note the fact that a slot has been deleted so | |
159 | // we can come back later to remove the iterator | |
160 | if (self->call_depth > 0) { | |
161 | self->flags.delayed_disconnect = true; | |
162 | } | |
163 | else { | |
164 | // Just remove the slot now, it's safe | |
165 | self->slots_.erase(*slot); | |
166 | } | |
167 | } | |
168 | } | |
169 | ||
170 | void signal_base_impl::remove_disconnected_slots() const | |
171 | { slots_.remove_disconnected_slots(); } | |
172 | ||
173 | call_notification:: | |
174 | call_notification(const shared_ptr<signal_base_impl>& b) : | |
175 | impl(b) | |
176 | { | |
177 | // A call will be made, so increment the call depth as a notification | |
178 | impl->call_depth++; | |
179 | } | |
180 | ||
181 | call_notification::~call_notification() | |
182 | { | |
183 | impl->call_depth--; | |
184 | ||
185 | // If the call depth is zero and we have some slots that have been | |
186 | // disconnected during the calls, remove those slots from the list | |
187 | if (impl->call_depth == 0 && | |
188 | impl->flags.delayed_disconnect) { | |
189 | impl->remove_disconnected_slots(); | |
190 | impl->flags.delayed_disconnect = false; | |
191 | } | |
192 | } | |
193 | ||
194 | signal_base::signal_base(const compare_type& comp, const any& combiner) | |
195 | : impl() | |
196 | { | |
197 | impl.reset(new signal_base_impl(comp, combiner)); | |
198 | } | |
199 | ||
200 | signal_base::~signal_base() | |
201 | { | |
202 | } | |
203 | ||
204 | } // namespace detail | |
205 | } // namespace BOOST_SIGNALS_NAMESPACE | |
206 | } // namespace boost | |
207 |