1 | // |
2 | // basic_io_object.hpp |
3 | // ~~~~~~~~~~~~~~~~~~~ |
4 | // |
5 | // Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com) |
6 | // |
7 | // Distributed under the Boost Software License, Version 1.0. (See accompanying |
8 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
9 | // |
10 | |
11 | #ifndef BOOST_ASIO_BASIC_IO_OBJECT_HPP |
12 | #define BOOST_ASIO_BASIC_IO_OBJECT_HPP |
13 | |
14 | #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
15 | # pragma once |
16 | #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
17 | |
18 | #include <boost/asio/detail/config.hpp> |
19 | #include <boost/asio/io_context.hpp> |
20 | |
21 | #include <boost/asio/detail/push_options.hpp> |
22 | |
23 | namespace boost { |
24 | namespace asio { |
25 | |
26 | namespace detail |
27 | { |
28 | // Type trait used to determine whether a service supports move. |
29 | template <typename IoObjectService> |
30 | class service_has_move |
31 | { |
32 | private: |
33 | typedef IoObjectService service_type; |
34 | typedef typename service_type::implementation_type implementation_type; |
35 | |
36 | template <typename T, typename U> |
37 | static auto asio_service_has_move_eval(T* t, U* u) |
38 | -> decltype(t->move_construct(*u, *u), char()); |
39 | static char (&asio_service_has_move_eval(...))[2]; |
40 | |
41 | public: |
42 | static const bool value = |
43 | sizeof(asio_service_has_move_eval( |
44 | static_cast<service_type*>(0), |
45 | static_cast<implementation_type*>(0))) == 1; |
46 | }; |
47 | } |
48 | |
49 | /// Base class for all I/O objects. |
50 | /** |
51 | * @note All I/O objects are non-copyable. However, when using C++0x, certain |
52 | * I/O objects do support move construction and move assignment. |
53 | */ |
54 | #if defined(GENERATING_DOCUMENTATION) |
55 | template <typename IoObjectService> |
56 | #else |
57 | template <typename IoObjectService, |
58 | bool Movable = detail::service_has_move<IoObjectService>::value> |
59 | #endif |
60 | class basic_io_object |
61 | { |
62 | public: |
63 | /// The type of the service that will be used to provide I/O operations. |
64 | typedef IoObjectService service_type; |
65 | |
66 | /// The underlying implementation type of I/O object. |
67 | typedef typename service_type::implementation_type implementation_type; |
68 | |
69 | #if !defined(BOOST_ASIO_NO_DEPRECATED) |
70 | /// (Deprecated: Use get_executor().) Get the io_context associated with the |
71 | /// object. |
72 | /** |
73 | * This function may be used to obtain the io_context object that the I/O |
74 | * object uses to dispatch handlers for asynchronous operations. |
75 | * |
76 | * @return A reference to the io_context object that the I/O object will use |
77 | * to dispatch handlers. Ownership is not transferred to the caller. |
78 | */ |
79 | boost::asio::io_context& get_io_context() |
80 | { |
81 | return service_.get_io_context(); |
82 | } |
83 | |
84 | /// (Deprecated: Use get_executor().) Get the io_context associated with the |
85 | /// object. |
86 | /** |
87 | * This function may be used to obtain the io_context object that the I/O |
88 | * object uses to dispatch handlers for asynchronous operations. |
89 | * |
90 | * @return A reference to the io_context object that the I/O object will use |
91 | * to dispatch handlers. Ownership is not transferred to the caller. |
92 | */ |
93 | boost::asio::io_context& get_io_service() |
94 | { |
95 | return service_.get_io_context(); |
96 | } |
97 | #endif // !defined(BOOST_ASIO_NO_DEPRECATED) |
98 | |
99 | /// The type of the executor associated with the object. |
100 | typedef boost::asio::io_context::executor_type executor_type; |
101 | |
102 | /// Get the executor associated with the object. |
103 | executor_type get_executor() noexcept |
104 | { |
105 | return service_.get_io_context().get_executor(); |
106 | } |
107 | |
108 | protected: |
109 | /// Construct a basic_io_object. |
110 | /** |
111 | * Performs: |
112 | * @code get_service().construct(get_implementation()); @endcode |
113 | */ |
114 | explicit basic_io_object(boost::asio::io_context& io_context) |
115 | : service_(boost::asio::use_service<IoObjectService>(io_context)) |
116 | { |
117 | service_.construct(implementation_); |
118 | } |
119 | |
120 | #if defined(GENERATING_DOCUMENTATION) |
121 | /// Move-construct a basic_io_object. |
122 | /** |
123 | * Performs: |
124 | * @code get_service().move_construct( |
125 | * get_implementation(), other.get_implementation()); @endcode |
126 | * |
127 | * @note Available only for services that support movability, |
128 | */ |
129 | basic_io_object(basic_io_object&& other); |
130 | |
131 | /// Move-assign a basic_io_object. |
132 | /** |
133 | * Performs: |
134 | * @code get_service().move_assign(get_implementation(), |
135 | * other.get_service(), other.get_implementation()); @endcode |
136 | * |
137 | * @note Available only for services that support movability, |
138 | */ |
139 | basic_io_object& operator=(basic_io_object&& other); |
140 | |
141 | /// Perform a converting move-construction of a basic_io_object. |
142 | template <typename IoObjectService1> |
143 | basic_io_object(IoObjectService1& other_service, |
144 | typename IoObjectService1::implementation_type& other_implementation); |
145 | #endif // defined(GENERATING_DOCUMENTATION) |
146 | |
147 | /// Protected destructor to prevent deletion through this type. |
148 | /** |
149 | * Performs: |
150 | * @code get_service().destroy(get_implementation()); @endcode |
151 | */ |
152 | ~basic_io_object() |
153 | { |
154 | service_.destroy(implementation_); |
155 | } |
156 | |
157 | /// Get the service associated with the I/O object. |
158 | service_type& get_service() |
159 | { |
160 | return service_; |
161 | } |
162 | |
163 | /// Get the service associated with the I/O object. |
164 | const service_type& get_service() const |
165 | { |
166 | return service_; |
167 | } |
168 | |
169 | /// Get the underlying implementation of the I/O object. |
170 | implementation_type& get_implementation() |
171 | { |
172 | return implementation_; |
173 | } |
174 | |
175 | /// Get the underlying implementation of the I/O object. |
176 | const implementation_type& get_implementation() const |
177 | { |
178 | return implementation_; |
179 | } |
180 | |
181 | private: |
182 | basic_io_object(const basic_io_object&); |
183 | basic_io_object& operator=(const basic_io_object&); |
184 | |
185 | // The service associated with the I/O object. |
186 | service_type& service_; |
187 | |
188 | /// The underlying implementation of the I/O object. |
189 | implementation_type implementation_; |
190 | }; |
191 | |
192 | // Specialisation for movable objects. |
193 | template <typename IoObjectService> |
194 | class basic_io_object<IoObjectService, true> |
195 | { |
196 | public: |
197 | typedef IoObjectService service_type; |
198 | typedef typename service_type::implementation_type implementation_type; |
199 | |
200 | #if !defined(BOOST_ASIO_NO_DEPRECATED) |
201 | boost::asio::io_context& get_io_context() |
202 | { |
203 | return service_->get_io_context(); |
204 | } |
205 | |
206 | boost::asio::io_context& get_io_service() |
207 | { |
208 | return service_->get_io_context(); |
209 | } |
210 | #endif // !defined(BOOST_ASIO_NO_DEPRECATED) |
211 | |
212 | typedef boost::asio::io_context::executor_type executor_type; |
213 | |
214 | executor_type get_executor() noexcept |
215 | { |
216 | return service_->get_io_context().get_executor(); |
217 | } |
218 | |
219 | protected: |
220 | explicit basic_io_object(boost::asio::io_context& io_context) |
221 | : service_(&boost::asio::use_service<IoObjectService>(io_context)) |
222 | { |
223 | service_->construct(implementation_); |
224 | } |
225 | |
226 | basic_io_object(basic_io_object&& other) |
227 | : service_(&other.get_service()) |
228 | { |
229 | service_->move_construct(implementation_, other.implementation_); |
230 | } |
231 | |
232 | template <typename IoObjectService1> |
233 | basic_io_object(IoObjectService1& other_service, |
234 | typename IoObjectService1::implementation_type& other_implementation) |
235 | : service_(&boost::asio::use_service<IoObjectService>( |
236 | other_service.get_io_context())) |
237 | { |
238 | service_->converting_move_construct(implementation_, |
239 | other_service, other_implementation); |
240 | } |
241 | |
242 | ~basic_io_object() |
243 | { |
244 | service_->destroy(implementation_); |
245 | } |
246 | |
247 | basic_io_object& operator=(basic_io_object&& other) |
248 | { |
249 | service_->move_assign(implementation_, |
250 | *other.service_, other.implementation_); |
251 | service_ = other.service_; |
252 | return *this; |
253 | } |
254 | |
255 | service_type& get_service() |
256 | { |
257 | return *service_; |
258 | } |
259 | |
260 | const service_type& get_service() const |
261 | { |
262 | return *service_; |
263 | } |
264 | |
265 | implementation_type& get_implementation() |
266 | { |
267 | return implementation_; |
268 | } |
269 | |
270 | const implementation_type& get_implementation() const |
271 | { |
272 | return implementation_; |
273 | } |
274 | |
275 | private: |
276 | basic_io_object(const basic_io_object&); |
277 | void operator=(const basic_io_object&); |
278 | |
279 | IoObjectService* service_; |
280 | implementation_type implementation_; |
281 | }; |
282 | |
283 | } // namespace asio |
284 | } // namespace boost |
285 | |
286 | #include <boost/asio/detail/pop_options.hpp> |
287 | |
288 | #endif // BOOST_ASIO_BASIC_IO_OBJECT_HPP |
289 | |