1 | // |
2 | // system_executor.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_SYSTEM_EXECUTOR_HPP |
12 | #define BOOST_ASIO_SYSTEM_EXECUTOR_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/detail/memory.hpp> |
20 | #include <boost/asio/execution.hpp> |
21 | |
22 | #include <boost/asio/detail/push_options.hpp> |
23 | |
24 | namespace boost { |
25 | namespace asio { |
26 | |
27 | class system_context; |
28 | |
29 | /// An executor that uses arbitrary threads. |
30 | /** |
31 | * The system executor represents an execution context where functions are |
32 | * permitted to run on arbitrary threads. When the blocking.never property is |
33 | * established, the system executor will schedule the function to run on an |
34 | * unspecified system thread pool. When either blocking.possibly or |
35 | * blocking.always is established, the executor invokes the function |
36 | * immediately. |
37 | */ |
38 | template <typename Blocking, typename Relationship, typename Allocator> |
39 | class basic_system_executor |
40 | { |
41 | public: |
42 | /// Default constructor. |
43 | basic_system_executor() noexcept |
44 | : allocator_(Allocator()) |
45 | { |
46 | } |
47 | |
48 | #if !defined(GENERATING_DOCUMENTATION) |
49 | private: |
50 | friend struct boost_asio_require_fn::impl; |
51 | friend struct boost_asio_prefer_fn::impl; |
52 | #endif // !defined(GENERATING_DOCUMENTATION) |
53 | |
54 | /// Obtain an executor with the @c blocking.possibly property. |
55 | /** |
56 | * Do not call this function directly. It is intended for use with the |
57 | * boost::asio::require customisation point. |
58 | * |
59 | * For example: |
60 | * @code boost::asio::system_executor ex1; |
61 | * auto ex2 = boost::asio::require(ex1, |
62 | * boost::asio::execution::blocking.possibly); @endcode |
63 | */ |
64 | basic_system_executor<execution::blocking_t::possibly_t, |
65 | Relationship, Allocator> |
66 | require(execution::blocking_t::possibly_t) const |
67 | { |
68 | return basic_system_executor<execution::blocking_t::possibly_t, |
69 | Relationship, Allocator>(allocator_); |
70 | } |
71 | |
72 | /// Obtain an executor with the @c blocking.always property. |
73 | /** |
74 | * Do not call this function directly. It is intended for use with the |
75 | * boost::asio::require customisation point. |
76 | * |
77 | * For example: |
78 | * @code boost::asio::system_executor ex1; |
79 | * auto ex2 = boost::asio::require(ex1, |
80 | * boost::asio::execution::blocking.always); @endcode |
81 | */ |
82 | basic_system_executor<execution::blocking_t::always_t, |
83 | Relationship, Allocator> |
84 | require(execution::blocking_t::always_t) const |
85 | { |
86 | return basic_system_executor<execution::blocking_t::always_t, |
87 | Relationship, Allocator>(allocator_); |
88 | } |
89 | |
90 | /// Obtain an executor with the @c blocking.never property. |
91 | /** |
92 | * Do not call this function directly. It is intended for use with the |
93 | * boost::asio::require customisation point. |
94 | * |
95 | * For example: |
96 | * @code boost::asio::system_executor ex1; |
97 | * auto ex2 = boost::asio::require(ex1, |
98 | * boost::asio::execution::blocking.never); @endcode |
99 | */ |
100 | basic_system_executor<execution::blocking_t::never_t, |
101 | Relationship, Allocator> |
102 | require(execution::blocking_t::never_t) const |
103 | { |
104 | return basic_system_executor<execution::blocking_t::never_t, |
105 | Relationship, Allocator>(allocator_); |
106 | } |
107 | |
108 | /// Obtain an executor with the @c relationship.continuation property. |
109 | /** |
110 | * Do not call this function directly. It is intended for use with the |
111 | * boost::asio::require customisation point. |
112 | * |
113 | * For example: |
114 | * @code boost::asio::system_executor ex1; |
115 | * auto ex2 = boost::asio::require(ex1, |
116 | * boost::asio::execution::relationship.continuation); @endcode |
117 | */ |
118 | basic_system_executor<Blocking, |
119 | execution::relationship_t::continuation_t, Allocator> |
120 | require(execution::relationship_t::continuation_t) const |
121 | { |
122 | return basic_system_executor<Blocking, |
123 | execution::relationship_t::continuation_t, Allocator>(allocator_); |
124 | } |
125 | |
126 | /// Obtain an executor with the @c relationship.fork property. |
127 | /** |
128 | * Do not call this function directly. It is intended for use with the |
129 | * boost::asio::require customisation point. |
130 | * |
131 | * For example: |
132 | * @code boost::asio::system_executor ex1; |
133 | * auto ex2 = boost::asio::require(ex1, |
134 | * boost::asio::execution::relationship.fork); @endcode |
135 | */ |
136 | basic_system_executor<Blocking, |
137 | execution::relationship_t::fork_t, Allocator> |
138 | require(execution::relationship_t::fork_t) const |
139 | { |
140 | return basic_system_executor<Blocking, |
141 | execution::relationship_t::fork_t, Allocator>(allocator_); |
142 | } |
143 | |
144 | /// Obtain an executor with the specified @c allocator property. |
145 | /** |
146 | * Do not call this function directly. It is intended for use with the |
147 | * boost::asio::require customisation point. |
148 | * |
149 | * For example: |
150 | * @code boost::asio::system_executor ex1; |
151 | * auto ex2 = boost::asio::require(ex1, |
152 | * boost::asio::execution::allocator(my_allocator)); @endcode |
153 | */ |
154 | template <typename OtherAllocator> |
155 | basic_system_executor<Blocking, Relationship, OtherAllocator> |
156 | require(execution::allocator_t<OtherAllocator> a) const |
157 | { |
158 | return basic_system_executor<Blocking, |
159 | Relationship, OtherAllocator>(a.value()); |
160 | } |
161 | |
162 | /// Obtain an executor with the default @c allocator property. |
163 | /** |
164 | * Do not call this function directly. It is intended for use with the |
165 | * boost::asio::require customisation point. |
166 | * |
167 | * For example: |
168 | * @code boost::asio::system_executor ex1; |
169 | * auto ex2 = boost::asio::require(ex1, |
170 | * boost::asio::execution::allocator); @endcode |
171 | */ |
172 | basic_system_executor<Blocking, Relationship, std::allocator<void>> |
173 | require(execution::allocator_t<void>) const |
174 | { |
175 | return basic_system_executor<Blocking, |
176 | Relationship, std::allocator<void>>(); |
177 | } |
178 | |
179 | #if !defined(GENERATING_DOCUMENTATION) |
180 | private: |
181 | friend struct boost_asio_query_fn::impl; |
182 | friend struct boost::asio::execution::detail::blocking_t<0>; |
183 | friend struct boost::asio::execution::detail::mapping_t<0>; |
184 | friend struct boost::asio::execution::detail::outstanding_work_t<0>; |
185 | friend struct boost::asio::execution::detail::relationship_t<0>; |
186 | #endif // !defined(GENERATING_DOCUMENTATION) |
187 | |
188 | /// Query the current value of the @c mapping property. |
189 | /** |
190 | * Do not call this function directly. It is intended for use with the |
191 | * boost::asio::query customisation point. |
192 | * |
193 | * For example: |
194 | * @code boost::asio::system_executor ex; |
195 | * if (boost::asio::query(ex, boost::asio::execution::mapping) |
196 | * == boost::asio::execution::mapping.thread) |
197 | * ... @endcode |
198 | */ |
199 | static constexpr execution::mapping_t query( |
200 | execution::mapping_t) noexcept |
201 | { |
202 | return execution::mapping.thread; |
203 | } |
204 | |
205 | /// Query the current value of the @c context property. |
206 | /** |
207 | * Do not call this function directly. It is intended for use with the |
208 | * boost::asio::query customisation point. |
209 | * |
210 | * For example: |
211 | * @code boost::asio::system_executor ex; |
212 | * boost::asio::system_context& pool = boost::asio::query( |
213 | * ex, boost::asio::execution::context); @endcode |
214 | */ |
215 | static system_context& query(execution::context_t) noexcept; |
216 | |
217 | /// Query the current value of the @c blocking property. |
218 | /** |
219 | * Do not call this function directly. It is intended for use with the |
220 | * boost::asio::query customisation point. |
221 | * |
222 | * For example: |
223 | * @code boost::asio::system_executor ex; |
224 | * if (boost::asio::query(ex, boost::asio::execution::blocking) |
225 | * == boost::asio::execution::blocking.always) |
226 | * ... @endcode |
227 | */ |
228 | static constexpr execution::blocking_t query( |
229 | execution::blocking_t) noexcept |
230 | { |
231 | return Blocking(); |
232 | } |
233 | |
234 | /// Query the current value of the @c relationship property. |
235 | /** |
236 | * Do not call this function directly. It is intended for use with the |
237 | * boost::asio::query customisation point. |
238 | * |
239 | * For example: |
240 | * @code boost::asio::system_executor ex; |
241 | * if (boost::asio::query(ex, boost::asio::execution::relationship) |
242 | * == boost::asio::execution::relationship.continuation) |
243 | * ... @endcode |
244 | */ |
245 | static constexpr execution::relationship_t query( |
246 | execution::relationship_t) noexcept |
247 | { |
248 | return Relationship(); |
249 | } |
250 | |
251 | /// Query the current value of the @c allocator property. |
252 | /** |
253 | * Do not call this function directly. It is intended for use with the |
254 | * boost::asio::query customisation point. |
255 | * |
256 | * For example: |
257 | * @code boost::asio::system_executor ex; |
258 | * auto alloc = boost::asio::query(ex, |
259 | * boost::asio::execution::allocator); @endcode |
260 | */ |
261 | template <typename OtherAllocator> |
262 | constexpr Allocator query( |
263 | execution::allocator_t<OtherAllocator>) const noexcept |
264 | { |
265 | return allocator_; |
266 | } |
267 | |
268 | /// Query the current value of the @c allocator property. |
269 | /** |
270 | * Do not call this function directly. It is intended for use with the |
271 | * boost::asio::query customisation point. |
272 | * |
273 | * For example: |
274 | * @code boost::asio::system_executor ex; |
275 | * auto alloc = boost::asio::query(ex, |
276 | * boost::asio::execution::allocator); @endcode |
277 | */ |
278 | constexpr Allocator query( |
279 | execution::allocator_t<void>) const noexcept |
280 | { |
281 | return allocator_; |
282 | } |
283 | |
284 | /// Query the occupancy (recommended number of work items) for the system |
285 | /// context. |
286 | /** |
287 | * Do not call this function directly. It is intended for use with the |
288 | * boost::asio::query customisation point. |
289 | * |
290 | * For example: |
291 | * @code boost::asio::system_executor ex; |
292 | * std::size_t occupancy = boost::asio::query( |
293 | * ex, boost::asio::execution::occupancy); @endcode |
294 | */ |
295 | std::size_t query(execution::occupancy_t) const noexcept; |
296 | |
297 | public: |
298 | /// Compare two executors for equality. |
299 | /** |
300 | * Two executors are equal if they refer to the same underlying io_context. |
301 | */ |
302 | friend bool operator==(const basic_system_executor&, |
303 | const basic_system_executor&) noexcept |
304 | { |
305 | return true; |
306 | } |
307 | |
308 | /// Compare two executors for inequality. |
309 | /** |
310 | * Two executors are equal if they refer to the same underlying io_context. |
311 | */ |
312 | friend bool operator!=(const basic_system_executor&, |
313 | const basic_system_executor&) noexcept |
314 | { |
315 | return false; |
316 | } |
317 | |
318 | /// Execution function. |
319 | template <typename Function> |
320 | void execute(Function&& f) const |
321 | { |
322 | this->do_execute(static_cast<Function&&>(f), Blocking()); |
323 | } |
324 | |
325 | #if !defined(BOOST_ASIO_NO_TS_EXECUTORS) |
326 | public: |
327 | /// Obtain the underlying execution context. |
328 | system_context& context() const noexcept; |
329 | |
330 | /// Inform the executor that it has some outstanding work to do. |
331 | /** |
332 | * For the system executor, this is a no-op. |
333 | */ |
334 | void on_work_started() const noexcept |
335 | { |
336 | } |
337 | |
338 | /// Inform the executor that some work is no longer outstanding. |
339 | /** |
340 | * For the system executor, this is a no-op. |
341 | */ |
342 | void on_work_finished() const noexcept |
343 | { |
344 | } |
345 | |
346 | /// Request the system executor to invoke the given function object. |
347 | /** |
348 | * This function is used to ask the executor to execute the given function |
349 | * object. The function object will always be executed inside this function. |
350 | * |
351 | * @param f The function object to be called. The executor will make |
352 | * a copy of the handler object as required. The function signature of the |
353 | * function object must be: @code void function(); @endcode |
354 | * |
355 | * @param a An allocator that may be used by the executor to allocate the |
356 | * internal storage needed for function invocation. |
357 | */ |
358 | template <typename Function, typename OtherAllocator> |
359 | void dispatch(Function&& f, const OtherAllocator& a) const; |
360 | |
361 | /// Request the system executor to invoke the given function object. |
362 | /** |
363 | * This function is used to ask the executor to execute the given function |
364 | * object. The function object will never be executed inside this function. |
365 | * Instead, it will be scheduled to run on an unspecified system thread pool. |
366 | * |
367 | * @param f The function object to be called. The executor will make |
368 | * a copy of the handler object as required. The function signature of the |
369 | * function object must be: @code void function(); @endcode |
370 | * |
371 | * @param a An allocator that may be used by the executor to allocate the |
372 | * internal storage needed for function invocation. |
373 | */ |
374 | template <typename Function, typename OtherAllocator> |
375 | void post(Function&& f, const OtherAllocator& a) const; |
376 | |
377 | /// Request the system executor to invoke the given function object. |
378 | /** |
379 | * This function is used to ask the executor to execute the given function |
380 | * object. The function object will never be executed inside this function. |
381 | * Instead, it will be scheduled to run on an unspecified system thread pool. |
382 | * |
383 | * @param f The function object to be called. The executor will make |
384 | * a copy of the handler object as required. The function signature of the |
385 | * function object must be: @code void function(); @endcode |
386 | * |
387 | * @param a An allocator that may be used by the executor to allocate the |
388 | * internal storage needed for function invocation. |
389 | */ |
390 | template <typename Function, typename OtherAllocator> |
391 | void defer(Function&& f, const OtherAllocator& a) const; |
392 | #endif // !defined(BOOST_ASIO_NO_TS_EXECUTORS) |
393 | |
394 | private: |
395 | template <typename, typename, typename> friend class basic_system_executor; |
396 | |
397 | // Constructor used by require(). |
398 | basic_system_executor(const Allocator& a) |
399 | : allocator_(a) |
400 | { |
401 | } |
402 | |
403 | /// Execution helper implementation for the possibly blocking property. |
404 | template <typename Function> |
405 | void do_execute(Function&& f, |
406 | execution::blocking_t::possibly_t) const; |
407 | |
408 | /// Execution helper implementation for the always blocking property. |
409 | template <typename Function> |
410 | void do_execute(Function&& f, |
411 | execution::blocking_t::always_t) const; |
412 | |
413 | /// Execution helper implementation for the never blocking property. |
414 | template <typename Function> |
415 | void do_execute(Function&& f, |
416 | execution::blocking_t::never_t) const; |
417 | |
418 | // The allocator used for execution functions. |
419 | Allocator allocator_; |
420 | }; |
421 | |
422 | /// An executor that uses arbitrary threads. |
423 | /** |
424 | * The system executor represents an execution context where functions are |
425 | * permitted to run on arbitrary threads. When the blocking.never property is |
426 | * established, the system executor will schedule the function to run on an |
427 | * unspecified system thread pool. When either blocking.possibly or |
428 | * blocking.always is established, the executor invokes the function |
429 | * immediately. |
430 | */ |
431 | typedef basic_system_executor<execution::blocking_t::possibly_t, |
432 | execution::relationship_t::fork_t, std::allocator<void>> |
433 | system_executor; |
434 | |
435 | #if !defined(GENERATING_DOCUMENTATION) |
436 | |
437 | namespace traits { |
438 | |
439 | #if !defined(BOOST_ASIO_HAS_DEDUCED_EQUALITY_COMPARABLE_TRAIT) |
440 | |
441 | template <typename Blocking, typename Relationship, typename Allocator> |
442 | struct equality_comparable< |
443 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator> |
444 | > |
445 | { |
446 | static constexpr bool is_valid = true; |
447 | static constexpr bool is_noexcept = true; |
448 | }; |
449 | |
450 | #endif // !defined(BOOST_ASIO_HAS_DEDUCED_EQUALITY_COMPARABLE_TRAIT) |
451 | |
452 | #if !defined(BOOST_ASIO_HAS_DEDUCED_EXECUTE_MEMBER_TRAIT) |
453 | |
454 | template <typename Blocking, typename Relationship, |
455 | typename Allocator, typename Function> |
456 | struct execute_member< |
457 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
458 | Function |
459 | > |
460 | { |
461 | static constexpr bool is_valid = true; |
462 | static constexpr bool is_noexcept = false; |
463 | typedef void result_type; |
464 | }; |
465 | |
466 | #endif // !defined(BOOST_ASIO_HAS_DEDUCED_EXECUTE_MEMBER_TRAIT) |
467 | |
468 | #if !defined(BOOST_ASIO_HAS_DEDUCED_REQUIRE_MEMBER_TRAIT) |
469 | |
470 | template <typename Blocking, typename Relationship, typename Allocator> |
471 | struct require_member< |
472 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
473 | boost::asio::execution::blocking_t::possibly_t |
474 | > |
475 | { |
476 | static constexpr bool is_valid = true; |
477 | static constexpr bool is_noexcept = false; |
478 | typedef boost::asio::basic_system_executor< |
479 | boost::asio::execution::blocking_t::possibly_t, |
480 | Relationship, Allocator> result_type; |
481 | }; |
482 | |
483 | template <typename Blocking, typename Relationship, typename Allocator> |
484 | struct require_member< |
485 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
486 | boost::asio::execution::blocking_t::always_t |
487 | > |
488 | { |
489 | static constexpr bool is_valid = true; |
490 | static constexpr bool is_noexcept = false; |
491 | typedef boost::asio::basic_system_executor< |
492 | boost::asio::execution::blocking_t::always_t, |
493 | Relationship, Allocator> result_type; |
494 | }; |
495 | |
496 | template <typename Blocking, typename Relationship, typename Allocator> |
497 | struct require_member< |
498 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
499 | boost::asio::execution::blocking_t::never_t |
500 | > |
501 | { |
502 | static constexpr bool is_valid = true; |
503 | static constexpr bool is_noexcept = false; |
504 | typedef boost::asio::basic_system_executor< |
505 | boost::asio::execution::blocking_t::never_t, |
506 | Relationship, Allocator> result_type; |
507 | }; |
508 | |
509 | template <typename Blocking, typename Relationship, typename Allocator> |
510 | struct require_member< |
511 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
512 | boost::asio::execution::relationship_t::fork_t |
513 | > |
514 | { |
515 | static constexpr bool is_valid = true; |
516 | static constexpr bool is_noexcept = false; |
517 | typedef boost::asio::basic_system_executor<Blocking, |
518 | boost::asio::execution::relationship_t::fork_t, |
519 | Allocator> result_type; |
520 | }; |
521 | |
522 | template <typename Blocking, typename Relationship, typename Allocator> |
523 | struct require_member< |
524 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
525 | boost::asio::execution::relationship_t::continuation_t |
526 | > |
527 | { |
528 | static constexpr bool is_valid = true; |
529 | static constexpr bool is_noexcept = false; |
530 | typedef boost::asio::basic_system_executor<Blocking, |
531 | boost::asio::execution::relationship_t::continuation_t, |
532 | Allocator> result_type; |
533 | }; |
534 | |
535 | template <typename Blocking, typename Relationship, typename Allocator> |
536 | struct require_member< |
537 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
538 | boost::asio::execution::allocator_t<void> |
539 | > |
540 | { |
541 | static constexpr bool is_valid = true; |
542 | static constexpr bool is_noexcept = false; |
543 | typedef boost::asio::basic_system_executor<Blocking, |
544 | Relationship, std::allocator<void>> result_type; |
545 | }; |
546 | |
547 | template <typename Blocking, typename Relationship, |
548 | typename Allocator, typename OtherAllocator> |
549 | struct require_member< |
550 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
551 | boost::asio::execution::allocator_t<OtherAllocator> |
552 | > |
553 | { |
554 | static constexpr bool is_valid = true; |
555 | static constexpr bool is_noexcept = false; |
556 | typedef boost::asio::basic_system_executor<Blocking, |
557 | Relationship, OtherAllocator> result_type; |
558 | }; |
559 | |
560 | #endif // !defined(BOOST_ASIO_HAS_DEDUCED_REQUIRE_MEMBER_TRAIT) |
561 | |
562 | #if !defined(BOOST_ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT) |
563 | |
564 | template <typename Blocking, typename Relationship, |
565 | typename Allocator, typename Property> |
566 | struct query_static_constexpr_member< |
567 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
568 | Property, |
569 | typename boost::asio::enable_if< |
570 | boost::asio::is_convertible< |
571 | Property, |
572 | boost::asio::execution::mapping_t |
573 | >::value |
574 | >::type |
575 | > |
576 | { |
577 | static constexpr bool is_valid = true; |
578 | static constexpr bool is_noexcept = true; |
579 | typedef boost::asio::execution::mapping_t::thread_t result_type; |
580 | |
581 | static constexpr result_type value() noexcept |
582 | { |
583 | return result_type(); |
584 | } |
585 | }; |
586 | |
587 | #endif // !defined(BOOST_ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT) |
588 | |
589 | #if !defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT) |
590 | |
591 | template <typename Blocking, typename Relationship, |
592 | typename Allocator, typename Property> |
593 | struct query_member< |
594 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
595 | Property, |
596 | typename boost::asio::enable_if< |
597 | boost::asio::is_convertible< |
598 | Property, |
599 | boost::asio::execution::blocking_t |
600 | >::value |
601 | >::type |
602 | > |
603 | { |
604 | static constexpr bool is_valid = true; |
605 | static constexpr bool is_noexcept = true; |
606 | typedef boost::asio::execution::blocking_t result_type; |
607 | }; |
608 | |
609 | template <typename Blocking, typename Relationship, |
610 | typename Allocator, typename Property> |
611 | struct query_member< |
612 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
613 | Property, |
614 | typename boost::asio::enable_if< |
615 | boost::asio::is_convertible< |
616 | Property, |
617 | boost::asio::execution::relationship_t |
618 | >::value |
619 | >::type |
620 | > |
621 | { |
622 | static constexpr bool is_valid = true; |
623 | static constexpr bool is_noexcept = true; |
624 | typedef boost::asio::execution::relationship_t result_type; |
625 | }; |
626 | |
627 | template <typename Blocking, typename Relationship, typename Allocator> |
628 | struct query_member< |
629 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
630 | boost::asio::execution::context_t |
631 | > |
632 | { |
633 | static constexpr bool is_valid = true; |
634 | static constexpr bool is_noexcept = true; |
635 | typedef boost::asio::system_context& result_type; |
636 | }; |
637 | |
638 | template <typename Blocking, typename Relationship, typename Allocator> |
639 | struct query_member< |
640 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
641 | boost::asio::execution::allocator_t<void> |
642 | > |
643 | { |
644 | static constexpr bool is_valid = true; |
645 | static constexpr bool is_noexcept = true; |
646 | typedef Allocator result_type; |
647 | }; |
648 | |
649 | template <typename Blocking, typename Relationship, typename Allocator> |
650 | struct query_member< |
651 | boost::asio::basic_system_executor<Blocking, Relationship, Allocator>, |
652 | boost::asio::execution::allocator_t<Allocator> |
653 | > |
654 | { |
655 | static constexpr bool is_valid = true; |
656 | static constexpr bool is_noexcept = true; |
657 | typedef Allocator result_type; |
658 | }; |
659 | |
660 | #endif // !defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT) |
661 | |
662 | } // namespace traits |
663 | |
664 | #endif // !defined(GENERATING_DOCUMENTATION) |
665 | |
666 | } // namespace asio |
667 | } // namespace boost |
668 | |
669 | #include <boost/asio/detail/pop_options.hpp> |
670 | |
671 | #include <boost/asio/impl/system_executor.hpp> |
672 | |
673 | #endif // BOOST_ASIO_SYSTEM_EXECUTOR_HPP |
674 | |