libs/capy/include/boost/capy/when_any.hpp
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| 1 | // | ||
| 2 | // Copyright (c) 2026 Michael Vandeberg | ||
| 3 | // | ||
| 4 | // Distributed under the Boost Software License, Version 1.0. (See accompanying | ||
| 5 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | ||
| 6 | // | ||
| 7 | // Official repository: https://github.com/cppalliance/capy | ||
| 8 | // | ||
| 9 | |||
| 10 | #ifndef BOOST_CAPY_WHEN_ANY_HPP | ||
| 11 | #define BOOST_CAPY_WHEN_ANY_HPP | ||
| 12 | |||
| 13 | #include <boost/capy/detail/config.hpp> | ||
| 14 | #include <boost/capy/concept/executor.hpp> | ||
| 15 | #include <boost/capy/io_awaitable.hpp> | ||
| 16 | #include <boost/capy/coro.hpp> | ||
| 17 | #include <boost/capy/ex/executor_ref.hpp> | ||
| 18 | #include <boost/capy/ex/frame_allocator.hpp> | ||
| 19 | #include <boost/capy/task.hpp> | ||
| 20 | |||
| 21 | #include <array> | ||
| 22 | #include <atomic> | ||
| 23 | #include <exception> | ||
| 24 | #include <optional> | ||
| 25 | #include <stdexcept> | ||
| 26 | #include <stop_token> | ||
| 27 | #include <tuple> | ||
| 28 | #include <type_traits> | ||
| 29 | #include <utility> | ||
| 30 | #include <variant> | ||
| 31 | #include <vector> | ||
| 32 | |||
| 33 | /* | ||
| 34 | * when_any - Race multiple tasks, return first completion | ||
| 35 | * ======================================================== | ||
| 36 | * | ||
| 37 | * OVERVIEW: | ||
| 38 | * --------- | ||
| 39 | * when_any launches N tasks concurrently and completes when the FIRST task | ||
| 40 | * finishes (success or failure). It then requests stop for all siblings and | ||
| 41 | * waits for them to acknowledge before returning. | ||
| 42 | * | ||
| 43 | * ARCHITECTURE: | ||
| 44 | * ------------- | ||
| 45 | * The design mirrors when_all but with inverted completion semantics: | ||
| 46 | * | ||
| 47 | * when_all: complete when remaining_count reaches 0 (all done) | ||
| 48 | * when_any: complete when has_winner becomes true (first done) | ||
| 49 | * BUT still wait for remaining_count to reach 0 for cleanup | ||
| 50 | * | ||
| 51 | * Key components: | ||
| 52 | * - when_any_state: Shared state tracking winner and completion | ||
| 53 | * - when_any_runner: Wrapper coroutine for each child task | ||
| 54 | * - when_any_launcher: Awaitable that starts all runners concurrently | ||
| 55 | * | ||
| 56 | * CRITICAL INVARIANTS: | ||
| 57 | * -------------------- | ||
| 58 | * 1. Exactly one task becomes the winner (via atomic compare_exchange) | ||
| 59 | * 2. All tasks must complete before parent resumes (cleanup safety) | ||
| 60 | * 3. Stop is requested immediately when winner is determined | ||
| 61 | * 4. Only the winner's result/exception is stored | ||
| 62 | * | ||
| 63 | * TYPE DEDUPLICATION: | ||
| 64 | * ------------------- | ||
| 65 | * std::variant requires unique alternative types. Since when_any can race | ||
| 66 | * tasks with identical return types (e.g., three task<int>), we must | ||
| 67 | * deduplicate types before constructing the variant. | ||
| 68 | * | ||
| 69 | * Example: when_any(task<int>, task<string>, task<int>) | ||
| 70 | * - Raw types after void->monostate: int, string, int | ||
| 71 | * - Deduplicated variant: std::variant<int, string> | ||
| 72 | * - Return: pair<size_t, variant<int, string>> | ||
| 73 | * | ||
| 74 | * The winner_index tells you which task won (0, 1, or 2), while the variant | ||
| 75 | * holds the result. Use the index to determine how to interpret the variant. | ||
| 76 | * | ||
| 77 | * VOID HANDLING: | ||
| 78 | * -------------- | ||
| 79 | * void tasks contribute std::monostate to the variant (then deduplicated). | ||
| 80 | * All-void tasks result in: pair<size_t, variant<monostate>> | ||
| 81 | * | ||
| 82 | * MEMORY MODEL: | ||
| 83 | * ------------- | ||
| 84 | * Synchronization chain from winner's write to parent's read: | ||
| 85 | * | ||
| 86 | * 1. Winner thread writes result_/winner_exception_ (non-atomic) | ||
| 87 | * 2. Winner thread calls signal_completion() → fetch_sub(acq_rel) on remaining_count_ | ||
| 88 | * 3. Last task thread (may be winner or non-winner) calls signal_completion() | ||
| 89 | * → fetch_sub(acq_rel) on remaining_count_, observing count becomes 0 | ||
| 90 | * 4. Last task returns caller_ex_.dispatch(continuation_) via symmetric transfer | ||
| 91 | * 5. Parent coroutine resumes and reads result_/winner_exception_ | ||
| 92 | * | ||
| 93 | * Synchronization analysis: | ||
| 94 | * - All fetch_sub operations on remaining_count_ form a release sequence | ||
| 95 | * - Winner's fetch_sub releases; subsequent fetch_sub operations participate | ||
| 96 | * in the modification order of remaining_count_ | ||
| 97 | * - Last task's fetch_sub(acq_rel) synchronizes-with prior releases in the | ||
| 98 | * modification order, establishing happens-before from winner's writes | ||
| 99 | * - Executor dispatch() is expected to provide queue-based synchronization | ||
| 100 | * (release-on-post, acquire-on-execute) completing the chain to parent | ||
| 101 | * - Even inline executors work (same thread = sequenced-before) | ||
| 102 | * | ||
| 103 | * Alternative considered: Adding winner_ready_ atomic (set with release after | ||
| 104 | * storing winner data, acquired before reading) would make synchronization | ||
| 105 | * self-contained and not rely on executor implementation details. Current | ||
| 106 | * approach is correct but requires careful reasoning about release sequences | ||
| 107 | * and executor behavior. | ||
| 108 | * | ||
| 109 | * EXCEPTION SEMANTICS: | ||
| 110 | * -------------------- | ||
| 111 | * Unlike when_all (which captures first exception, discards others), when_any | ||
| 112 | * treats exceptions as valid completions. If the winning task threw, that | ||
| 113 | * exception is rethrown. Exceptions from non-winners are silently discarded. | ||
| 114 | */ | ||
| 115 | |||
| 116 | namespace boost { | ||
| 117 | namespace capy { | ||
| 118 | |||
| 119 | namespace detail { | ||
| 120 | |||
| 121 | /** Convert void to monostate for variant storage. | ||
| 122 | |||
| 123 | std::variant<void, ...> is ill-formed, so void tasks contribute | ||
| 124 | std::monostate to the result variant instead. Non-void types | ||
| 125 | pass through unchanged. | ||
| 126 | |||
| 127 | @tparam T The type to potentially convert (void becomes monostate). | ||
| 128 | */ | ||
| 129 | template<typename T> | ||
| 130 | using void_to_monostate_t = std::conditional_t<std::is_void_v<T>, std::monostate, T>; | ||
| 131 | |||
| 132 | /** Type deduplication for variant construction. | ||
| 133 | |||
| 134 | std::variant requires unique alternative types. These metafunctions | ||
| 135 | deduplicate a type list while preserving order of first occurrence. | ||
| 136 | |||
| 137 | @par Algorithm | ||
| 138 | Fold left over the type list, appending each type to the accumulator | ||
| 139 | only if not already present. O(N^2) in number of types but N is | ||
| 140 | typically small (number of when_any arguments). | ||
| 141 | */ | ||
| 142 | /** Primary template for appending a type to a variant if not already present. | ||
| 143 | |||
| 144 | @tparam Variant The accumulated variant type. | ||
| 145 | @tparam T The type to potentially append. | ||
| 146 | */ | ||
| 147 | template<typename Variant, typename T> | ||
| 148 | struct variant_append_if_unique; | ||
| 149 | |||
| 150 | /** Specialization that checks for type uniqueness and appends if needed. | ||
| 151 | |||
| 152 | @tparam Vs Types already in the variant. | ||
| 153 | @tparam T The type to potentially append. | ||
| 154 | */ | ||
| 155 | template<typename... Vs, typename T> | ||
| 156 | struct variant_append_if_unique<std::variant<Vs...>, T> | ||
| 157 | { | ||
| 158 | /** Result type: original variant if T is duplicate, extended variant otherwise. */ | ||
| 159 | using type = std::conditional_t< | ||
| 160 | (std::is_same_v<T, Vs> || ...), | ||
| 161 | std::variant<Vs...>, | ||
| 162 | std::variant<Vs..., T>>; | ||
| 163 | }; | ||
| 164 | |||
| 165 | /** Primary template for type list deduplication. | ||
| 166 | |||
| 167 | @tparam Accumulated The variant accumulating unique types. | ||
| 168 | @tparam Remaining Types still to be processed. | ||
| 169 | */ | ||
| 170 | template<typename Accumulated, typename... Remaining> | ||
| 171 | struct deduplicate_impl; | ||
| 172 | |||
| 173 | /** Base case: no more types to process. | ||
| 174 | |||
| 175 | @tparam Accumulated The final deduplicated variant type. | ||
| 176 | */ | ||
| 177 | template<typename Accumulated> | ||
| 178 | struct deduplicate_impl<Accumulated> | ||
| 179 | { | ||
| 180 | /** The final deduplicated variant type. */ | ||
| 181 | using type = Accumulated; | ||
| 182 | }; | ||
| 183 | |||
| 184 | /** Recursive case: add T if unique, then process rest. | ||
| 185 | |||
| 186 | @tparam Accumulated The variant accumulated so far. | ||
| 187 | @tparam T The current type to potentially add. | ||
| 188 | @tparam Rest Remaining types to process. | ||
| 189 | */ | ||
| 190 | template<typename Accumulated, typename T, typename... Rest> | ||
| 191 | struct deduplicate_impl<Accumulated, T, Rest...> | ||
| 192 | { | ||
| 193 | /** Intermediate type after potentially appending T. */ | ||
| 194 | using next = typename variant_append_if_unique<Accumulated, T>::type; | ||
| 195 | |||
| 196 | /** Final result after processing all remaining types. */ | ||
| 197 | using type = typename deduplicate_impl<next, Rest...>::type; | ||
| 198 | }; | ||
| 199 | |||
| 200 | /** Deduplicated variant from a list of types. | ||
| 201 | |||
| 202 | Constructs a std::variant containing unique types from the input list. | ||
| 203 | Void types are converted to std::monostate before deduplication. | ||
| 204 | The first type T0 seeds the accumulator, ensuring the variant is well-formed. | ||
| 205 | |||
| 206 | @tparam T0 First result type (required, seeds the deduplication). | ||
| 207 | @tparam Ts Remaining result types (void is converted to monostate). | ||
| 208 | */ | ||
| 209 | template<typename T0, typename... Ts> | ||
| 210 | using unique_variant_t = typename deduplicate_impl< | ||
| 211 | std::variant<void_to_monostate_t<T0>>, | ||
| 212 | void_to_monostate_t<Ts>...>::type; | ||
| 213 | |||
| 214 | /** Result type for when_any: (winner_index, deduplicated_variant). | ||
| 215 | |||
| 216 | The first element is the zero-based index of the winning task in the | ||
| 217 | original argument order. The second element is a variant holding the | ||
| 218 | winner's result by type. When multiple tasks share the same return type, | ||
| 219 | use the index to determine which task actually won. | ||
| 220 | |||
| 221 | @tparam T0 First task's result type. | ||
| 222 | @tparam Ts Remaining tasks' result types. | ||
| 223 | */ | ||
| 224 | template<typename T0, typename... Ts> | ||
| 225 | using when_any_result_t = std::pair<std::size_t, unique_variant_t<T0, Ts...>>; | ||
| 226 | |||
| 227 | /** Shared state for when_any operation. | ||
| 228 | |||
| 229 | Coordinates winner selection, result storage, and completion tracking | ||
| 230 | for all child tasks in a when_any operation. | ||
| 231 | |||
| 232 | @par Lifetime | ||
| 233 | Allocated on the parent coroutine's frame, outlives all runners. | ||
| 234 | |||
| 235 | @par Thread Safety | ||
| 236 | Atomic operations protect winner selection and completion count. | ||
| 237 | Result storage is written only by the winner before any concurrent access. | ||
| 238 | |||
| 239 | @tparam T0 First task's result type. | ||
| 240 | @tparam Ts Remaining tasks' result types. | ||
| 241 | */ | ||
| 242 | template<typename T0, typename... Ts> | ||
| 243 | struct when_any_state | ||
| 244 | { | ||
| 245 | /** Total number of tasks being raced. */ | ||
| 246 | static constexpr std::size_t task_count = 1 + sizeof...(Ts); | ||
| 247 | |||
| 248 | /** Deduplicated variant type for storing the winner's result. */ | ||
| 249 | using variant_type = unique_variant_t<T0, Ts...>; | ||
| 250 | |||
| 251 | /** Counter for tasks still running. | ||
| 252 | |||
| 253 | Must wait for ALL tasks to finish before parent resumes; this ensures | ||
| 254 | runner coroutine frames are valid until their final_suspend completes. | ||
| 255 | */ | ||
| 256 | std::atomic<std::size_t> remaining_count_; | ||
| 257 | |||
| 258 | /** Flag indicating whether a winner has been determined. | ||
| 259 | |||
| 260 | Winner selection: exactly one task wins via atomic CAS on has_winner_. | ||
| 261 | winner_index_ is written only by the winner, read after all complete. | ||
| 262 | */ | ||
| 263 | std::atomic<bool> has_winner_{false}; | ||
| 264 | |||
| 265 | /** Index of the winning task in the original argument list. */ | ||
| 266 | std::size_t winner_index_{0}; | ||
| 267 | |||
| 268 | /** Storage for the winner's result value. | ||
| 269 | |||
| 270 | Result storage: deduplicated variant. Stored by type, not task index, | ||
| 271 | because multiple tasks may share the same return type. | ||
| 272 | */ | ||
| 273 | std::optional< variant_type > result_; | ||
| 274 | |||
| 275 | /** Exception thrown by the winner, if any. | ||
| 276 | |||
| 277 | Non-null if winner threw (rethrown to caller after all tasks complete). | ||
| 278 | */ | ||
| 279 | std::exception_ptr winner_exception_; | ||
| 280 | |||
| 281 | /** Handles to runner coroutines for cleanup. | ||
| 282 | |||
| 283 | Runner coroutine handles; destroyed in destructor after all complete. | ||
| 284 | */ | ||
| 285 | std::array<coro, task_count> runner_handles_{}; | ||
| 286 | |||
| 287 | /** Stop source for cancelling sibling tasks. | ||
| 288 | |||
| 289 | Owned stop_source: request_stop() called when winner determined. | ||
| 290 | */ | ||
| 291 | std::stop_source stop_source_; | ||
| 292 | |||
| 293 | /** Callback functor that forwards stop requests. | ||
| 294 | |||
| 295 | Forwards parent's stop requests to our stop_source, enabling | ||
| 296 | cancellation to propagate from caller through when_any to children. | ||
| 297 | */ | ||
| 298 | struct stop_callback_fn | ||
| 299 | { | ||
| 300 | /** Pointer to the stop source to signal. */ | ||
| 301 | std::stop_source* source_; | ||
| 302 | |||
| 303 | /** Invoke the stop request on the source. */ | ||
| 304 | 4 | void operator()() const noexcept { source_->request_stop(); } | |
| 305 | }; | ||
| 306 | |||
| 307 | /** Type alias for the stop callback registration. */ | ||
| 308 | using stop_callback_t = std::stop_callback<stop_callback_fn>; | ||
| 309 | |||
| 310 | /** Optional callback linking parent's stop token to our stop source. */ | ||
| 311 | std::optional<stop_callback_t> parent_stop_callback_; | ||
| 312 | |||
| 313 | /** Parent coroutine handle to resume when all children complete. */ | ||
| 314 | coro continuation_; | ||
| 315 | |||
| 316 | /** Executor reference for dispatching the parent resumption. */ | ||
| 317 | executor_ref caller_ex_; | ||
| 318 | |||
| 319 | /** Construct state for racing task_count tasks. | ||
| 320 | |||
| 321 | Initializes remaining_count_ to task_count so all tasks must complete | ||
| 322 | before the parent coroutine resumes. | ||
| 323 | */ | ||
| 324 | 37 | when_any_state() | |
| 325 |
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37 | : remaining_count_(task_count) |
| 326 | { | ||
| 327 | 37 | } | |
| 328 | |||
| 329 | /** Destroy state and clean up runner coroutine handles. | ||
| 330 | |||
| 331 | All runners must have completed before destruction (guaranteed by | ||
| 332 | waiting for remaining_count_ to reach zero). | ||
| 333 | */ | ||
| 334 | 37 | ~when_any_state() | |
| 335 | { | ||
| 336 |
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130 | for(auto h : runner_handles_) |
| 337 |
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93 | if(h) |
| 338 | 93 | h.destroy(); | |
| 339 | 37 | } | |
| 340 | |||
| 341 | /** Attempt to become the winner. | ||
| 342 | |||
| 343 | Atomically claims winner status. Exactly one task succeeds; all others | ||
| 344 | see false. The winner must store its result before returning. | ||
| 345 | |||
| 346 | @param index The task's index in the original argument list. | ||
| 347 | @return true if this task is now the winner, false if another won first. | ||
| 348 | */ | ||
| 349 | 93 | bool try_win(std::size_t index) noexcept | |
| 350 | { | ||
| 351 | 93 | bool expected = false; | |
| 352 |
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93 | if(has_winner_.compare_exchange_strong( |
| 353 | expected, true, std::memory_order_acq_rel)) | ||
| 354 | { | ||
| 355 | 37 | winner_index_ = index; | |
| 356 | // Signal siblings to exit early if they support cancellation | ||
| 357 | 37 | stop_source_.request_stop(); | |
| 358 | 37 | return true; | |
| 359 | } | ||
| 360 | 56 | return false; | |
| 361 | } | ||
| 362 | |||
| 363 | /** Store the winner's result. | ||
| 364 | |||
| 365 | @pre Only called by the winner (try_win returned true). | ||
| 366 | @note Uses type-based emplacement because the variant is deduplicated; | ||
| 367 | task index may differ from variant alternative index. | ||
| 368 | */ | ||
| 369 | template<typename T> | ||
| 370 | 30 | void set_winner_result(T value) | |
| 371 | noexcept(std::is_nothrow_move_constructible_v<T>) | ||
| 372 | { | ||
| 373 | 30 | result_.emplace(std::in_place_type<T>, std::move(value)); | |
| 374 | 30 | } | |
| 375 | |||
| 376 | /** Store the winner's void completion as monostate. | ||
| 377 | |||
| 378 | @pre Only called by the winner of a void-returning task. | ||
| 379 | */ | ||
| 380 | 2 | void set_winner_void() noexcept | |
| 381 | { | ||
| 382 | 2 | result_.emplace(std::in_place_type<std::monostate>, std::monostate{}); | |
| 383 | 2 | } | |
| 384 | |||
| 385 | /** Store the winner's exception. | ||
| 386 | |||
| 387 | @pre Only called by the winner (try_win returned true). | ||
| 388 | */ | ||
| 389 | 5 | void set_winner_exception(std::exception_ptr ep) noexcept | |
| 390 | { | ||
| 391 | 5 | winner_exception_ = ep; | |
| 392 | 5 | } | |
| 393 | |||
| 394 | /** Signal that a task has completed (success, failure, or cancelled). | ||
| 395 | |||
| 396 | Called by every runner at final_suspend. The last one to complete | ||
| 397 | resumes the parent coroutine. This ensures all child coroutine | ||
| 398 | frames are destroyed before the parent continues. | ||
| 399 | |||
| 400 | @return Coroutine to resume (parent if last, noop otherwise). | ||
| 401 | */ | ||
| 402 | 93 | coro signal_completion() noexcept | |
| 403 | { | ||
| 404 | 93 | auto remaining = remaining_count_.fetch_sub(1, std::memory_order_acq_rel); | |
| 405 |
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|
93 | if(remaining == 1) |
| 406 | 37 | return caller_ex_.dispatch(continuation_); | |
| 407 | 56 | return std::noop_coroutine(); | |
| 408 | } | ||
| 409 | }; | ||
| 410 | |||
| 411 | /** Wrapper coroutine that runs a single child task for when_any. | ||
| 412 | |||
| 413 | Each child task is wrapped in a runner that: | ||
| 414 | 1. Propagates executor and stop_token to the child | ||
| 415 | 2. Attempts to claim winner status on completion | ||
| 416 | 3. Stores result only if this runner won | ||
| 417 | 4. Signals completion regardless of win/loss (for cleanup) | ||
| 418 | |||
| 419 | @tparam T The result type of the wrapped task. | ||
| 420 | @tparam Ts All task result types (for when_any_state compatibility). | ||
| 421 | */ | ||
| 422 | template<typename T, typename... Ts> | ||
| 423 | struct when_any_runner | ||
| 424 | { | ||
| 425 | /** Promise type for the runner coroutine. | ||
| 426 | |||
| 427 | Manages executor propagation, stop token forwarding, and completion | ||
| 428 | signaling for the wrapped child task. | ||
| 429 | */ | ||
| 430 | struct promise_type : frame_allocating_base | ||
| 431 | { | ||
| 432 | /** Pointer to shared state for winner coordination. */ | ||
| 433 | when_any_state<Ts...>* state_ = nullptr; | ||
| 434 | |||
| 435 | /** Index of this task in the original argument list. */ | ||
| 436 | std::size_t index_ = 0; | ||
| 437 | |||
| 438 | /** Executor reference inherited from the parent coroutine. */ | ||
| 439 | executor_ref ex_; | ||
| 440 | |||
| 441 | /** Stop token for cooperative cancellation. */ | ||
| 442 | std::stop_token stop_token_; | ||
| 443 | |||
| 444 | /** Create the runner coroutine object from this promise. | ||
| 445 | |||
| 446 | @return Runner coroutine wrapping this promise's coroutine handle. | ||
| 447 | */ | ||
| 448 | 93 | when_any_runner get_return_object() | |
| 449 | { | ||
| 450 | 93 | return when_any_runner(std::coroutine_handle<promise_type>::from_promise(*this)); | |
| 451 | } | ||
| 452 | |||
| 453 | /** Suspend immediately on creation. | ||
| 454 | |||
| 455 | Runner coroutines start suspended; the launcher resumes them | ||
| 456 | after setting up state_, index_, ex_, and stop_token_. | ||
| 457 | |||
| 458 | @return Always suspends. | ||
| 459 | */ | ||
| 460 | 93 | std::suspend_always initial_suspend() noexcept | |
| 461 | { | ||
| 462 | 93 | return {}; | |
| 463 | } | ||
| 464 | |||
| 465 | /** Final suspend awaiter that signals completion to shared state. | ||
| 466 | |||
| 467 | @return Custom awaiter that calls signal_completion(). | ||
| 468 | */ | ||
| 469 | 93 | auto final_suspend() noexcept | |
| 470 | { | ||
| 471 | /** Awaiter that signals task completion and potentially resumes parent. */ | ||
| 472 | struct awaiter | ||
| 473 | { | ||
| 474 | /** Pointer to the promise for accessing shared state. */ | ||
| 475 | promise_type* p_; | ||
| 476 | |||
| 477 | /** Never ready; always suspend to signal completion. | ||
| 478 | |||
| 479 | @return Always false. | ||
| 480 | */ | ||
| 481 | bool await_ready() const noexcept | ||
| 482 | { | ||
| 483 | return false; | ||
| 484 | } | ||
| 485 | |||
| 486 | /** Signal completion and return next coroutine to resume. | ||
| 487 | |||
| 488 | @return Parent coroutine if this was the last task, noop otherwise. | ||
| 489 | */ | ||
| 490 | coro await_suspend(coro) noexcept | ||
| 491 | { | ||
| 492 | return p_->state_->signal_completion(); | ||
| 493 | } | ||
| 494 | |||
| 495 | /** No-op resume; coroutine is destroyed after final suspend. */ | ||
| 496 | void await_resume() const noexcept | ||
| 497 | { | ||
| 498 | } | ||
| 499 | }; | ||
| 500 | 93 | return awaiter{this}; | |
| 501 | } | ||
| 502 | |||
| 503 | /** Called when runner coroutine body completes normally. | ||
| 504 | |||
| 505 | The actual result handling is done in make_when_any_runner; | ||
| 506 | this just satisfies the coroutine return requirement. | ||
| 507 | */ | ||
| 508 | 84 | void return_void() | |
| 509 | { | ||
| 510 | 84 | } | |
| 511 | |||
| 512 | /** Handle exceptions thrown by the child task. | ||
| 513 | |||
| 514 | Exceptions are valid completions in when_any (unlike when_all). | ||
| 515 | If this exception wins, it will be rethrown to the caller. | ||
| 516 | If another task already won, this exception is discarded. | ||
| 517 | */ | ||
| 518 | 9 | void unhandled_exception() | |
| 519 | { | ||
| 520 |
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9 | if(state_->try_win(index_)) |
| 521 | 5 | state_->set_winner_exception(std::current_exception()); | |
| 522 | 9 | } | |
| 523 | |||
| 524 | /** Awaiter wrapper that injects executor and stop token into child awaitables. | ||
| 525 | |||
| 526 | @tparam Awaitable The underlying awaitable type being wrapped. | ||
| 527 | */ | ||
| 528 | template<class Awaitable> | ||
| 529 | struct transform_awaiter | ||
| 530 | { | ||
| 531 | /** The wrapped awaitable instance. */ | ||
| 532 | std::decay_t<Awaitable> a_; | ||
| 533 | |||
| 534 | /** Pointer to promise for accessing executor and stop token. */ | ||
| 535 | promise_type* p_; | ||
| 536 | |||
| 537 | /** Check if the underlying awaitable is ready. | ||
| 538 | |||
| 539 | @return True if awaitable can complete synchronously. | ||
| 540 | */ | ||
| 541 | 93 | bool await_ready() | |
| 542 | { | ||
| 543 | 93 | return a_.await_ready(); | |
| 544 | } | ||
| 545 | |||
| 546 | /** Get the result from the underlying awaitable. | ||
| 547 | |||
| 548 | @return The awaitable's result value. | ||
| 549 | */ | ||
| 550 | 93 | auto await_resume() | |
| 551 | { | ||
| 552 | 93 | return a_.await_resume(); | |
| 553 | } | ||
| 554 | |||
| 555 | /** Suspend with executor and stop token injection. | ||
| 556 | |||
| 557 | @tparam Promise The suspending coroutine's promise type. | ||
| 558 | @param h Handle to the suspending coroutine. | ||
| 559 | @return Coroutine to resume or void. | ||
| 560 | */ | ||
| 561 | template<class Promise> | ||
| 562 | 93 | auto await_suspend(std::coroutine_handle<Promise> h) | |
| 563 | { | ||
| 564 |
15/15auto boost::capy::detail::when_any_runner<double, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::promise_type::transform_awaiter<boost::capy::task<double> >::await_suspend<boost::capy::detail::when_any_runner<double, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<double, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::promise_type>):
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auto boost::capy::detail::when_any_runner<int, int, int, int, int, int, int, int, int>::promise_type::transform_awaiter<boost::capy::task<int> >::await_suspend<boost::capy::detail::when_any_runner<int, int, int, int, int, int, int, int, int>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<int, int, int, int, int, int, int, int, int>::promise_type>):
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auto boost::capy::detail::when_any_runner<int, int, int, int, int>::promise_type::transform_awaiter<boost::capy::task<int> >::await_suspend<boost::capy::detail::when_any_runner<int, int, int, int, int>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<int, int, int, int, int>::promise_type>):
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auto boost::capy::detail::when_any_runner<int, int, int, int>::promise_type::transform_awaiter<boost::capy::task<int> >::await_suspend<boost::capy::detail::when_any_runner<int, int, int, int>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<int, int, int, int>::promise_type>):
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auto boost::capy::detail::when_any_runner<int, int, int>::promise_type::transform_awaiter<boost::capy::task<int> >::await_suspend<boost::capy::detail::when_any_runner<int, int, int>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<int, int, int>::promise_type>):
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auto boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::promise_type::transform_awaiter<boost::capy::task<int> >::await_suspend<boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::promise_type>):
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auto boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::promise_type::transform_awaiter<boost::capy::task<int> >::await_suspend<boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::promise_type>):
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auto boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::promise_type::transform_awaiter<boost::capy::task<int> >::await_suspend<boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::promise_type>):
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auto boost::capy::detail::when_any_runner<int, int>::promise_type::transform_awaiter<boost::capy::task<int> >::await_suspend<boost::capy::detail::when_any_runner<int, int>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<int, int>::promise_type>):
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auto boost::capy::detail::when_any_runner<int, void, int>::promise_type::transform_awaiter<boost::capy::task<int> >::await_suspend<boost::capy::detail::when_any_runner<int, void, int>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<int, void, int>::promise_type>):
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auto boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::promise_type::transform_awaiter<boost::capy::task<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >::await_suspend<boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::promise_type>):
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auto boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::promise_type::transform_awaiter<boost::capy::task<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >::await_suspend<boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::promise_type>):
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auto boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::promise_type::transform_awaiter<boost::capy::task<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >::await_suspend<boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::promise_type>):
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auto boost::capy::detail::when_any_runner<void, void, int>::promise_type::transform_awaiter<boost::capy::task<void> >::await_suspend<boost::capy::detail::when_any_runner<void, void, int>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<void, void, int>::promise_type>):
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auto boost::capy::detail::when_any_runner<void, void, void, void>::promise_type::transform_awaiter<boost::capy::task<void> >::await_suspend<boost::capy::detail::when_any_runner<void, void, void, void>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_runner<void, void, void, void>::promise_type>):
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93 | return a_.await_suspend(h, p_->ex_, p_->stop_token_); |
| 565 | } | ||
| 566 | }; | ||
| 567 | |||
| 568 | /** Transform awaitables to inject executor and stop token. | ||
| 569 | |||
| 570 | @tparam Awaitable The awaitable type being co_awaited. | ||
| 571 | @param a The awaitable instance. | ||
| 572 | @return Transformed awaiter with executor/stop_token injection. | ||
| 573 | */ | ||
| 574 | template<class Awaitable> | ||
| 575 | 93 | auto await_transform(Awaitable&& a) | |
| 576 | { | ||
| 577 | using A = std::decay_t<Awaitable>; | ||
| 578 | if constexpr (IoAwaitable<A>) | ||
| 579 | { | ||
| 580 | return transform_awaiter<Awaitable>{ | ||
| 581 | 186 | std::forward<Awaitable>(a), this}; | |
| 582 | } | ||
| 583 | else | ||
| 584 | { | ||
| 585 | return make_affine(std::forward<Awaitable>(a), ex_); | ||
| 586 | } | ||
| 587 | 93 | } | |
| 588 | }; | ||
| 589 | |||
| 590 | /** Handle to the underlying coroutine frame. */ | ||
| 591 | std::coroutine_handle<promise_type> h_; | ||
| 592 | |||
| 593 | /** Construct runner from a coroutine handle. | ||
| 594 | |||
| 595 | @param h Handle to the runner coroutine frame. | ||
| 596 | */ | ||
| 597 | 93 | explicit when_any_runner(std::coroutine_handle<promise_type> h) noexcept | |
| 598 | 93 | : h_(h) | |
| 599 | { | ||
| 600 | 93 | } | |
| 601 | |||
| 602 | /** Move constructor (Clang 14 workaround). | ||
| 603 | |||
| 604 | Clang 14 (non-Apple) has a coroutine codegen bug requiring explicit | ||
| 605 | move constructor; other compilers work correctly with deleted move. | ||
| 606 | */ | ||
| 607 | #if defined(__clang__) && __clang_major__ == 14 && !defined(__apple_build_version__) | ||
| 608 | when_any_runner(when_any_runner&& other) noexcept : h_(std::exchange(other.h_, nullptr)) {} | ||
| 609 | #endif | ||
| 610 | |||
| 611 | /** Copy construction is not allowed. */ | ||
| 612 | when_any_runner(when_any_runner const&) = delete; | ||
| 613 | |||
| 614 | /** Copy assignment is not allowed. */ | ||
| 615 | when_any_runner& operator=(when_any_runner const&) = delete; | ||
| 616 | |||
| 617 | /** Move construction is deleted (except on Clang 14). */ | ||
| 618 | #if !defined(__clang__) || __clang_major__ != 14 || defined(__apple_build_version__) | ||
| 619 | when_any_runner(when_any_runner&&) = delete; | ||
| 620 | #endif | ||
| 621 | |||
| 622 | /** Move assignment is not allowed. */ | ||
| 623 | when_any_runner& operator=(when_any_runner&&) = delete; | ||
| 624 | |||
| 625 | /** Release ownership of the coroutine handle. | ||
| 626 | |||
| 627 | @return The coroutine handle; this object becomes empty. | ||
| 628 | */ | ||
| 629 | 93 | auto release() noexcept | |
| 630 | { | ||
| 631 | 93 | return std::exchange(h_, nullptr); | |
| 632 | } | ||
| 633 | }; | ||
| 634 | |||
| 635 | /** Create a runner coroutine for a single task in when_any. | ||
| 636 | |||
| 637 | Factory function that creates a wrapper coroutine for a child task. | ||
| 638 | The runner handles executor/stop_token propagation and winner selection. | ||
| 639 | |||
| 640 | @tparam Index Compile-time index of this task in the argument list. | ||
| 641 | @tparam T The result type of the task being wrapped. | ||
| 642 | @tparam Ts All task result types (for when_any_state compatibility). | ||
| 643 | @param inner The task to run (will be moved from). | ||
| 644 | @param state Shared state for winner coordination. | ||
| 645 | @return Runner coroutine (must be started via resume()). | ||
| 646 | */ | ||
| 647 | template<std::size_t Index, typename T, typename... Ts> | ||
| 648 | when_any_runner<T, Ts...> | ||
| 649 |
31/31boost::capy::detail::when_any_runner<double, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double> boost::capy::detail::make_when_any_runner<2ul, double, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>(boost::capy::task<double>, boost::capy::detail::when_any_state<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int, int, int, int, int> boost::capy::detail::make_when_any_runner<0ul, int, int, int, int, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int, int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int, int, int, int, int> boost::capy::detail::make_when_any_runner<1ul, int, int, int, int, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int, int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int, int, int, int, int> boost::capy::detail::make_when_any_runner<2ul, int, int, int, int, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int, int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int, int, int, int, int> boost::capy::detail::make_when_any_runner<3ul, int, int, int, int, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int, int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int, int, int, int, int> boost::capy::detail::make_when_any_runner<4ul, int, int, int, int, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int, int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int, int, int, int, int> boost::capy::detail::make_when_any_runner<5ul, int, int, int, int, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int, int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int, int, int, int, int> boost::capy::detail::make_when_any_runner<6ul, int, int, int, int, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int, int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int, int, int, int, int> boost::capy::detail::make_when_any_runner<7ul, int, int, int, int, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int, int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int> boost::capy::detail::make_when_any_runner<0ul, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int> boost::capy::detail::make_when_any_runner<1ul, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int> boost::capy::detail::make_when_any_runner<2ul, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int, int> boost::capy::detail::make_when_any_runner<3ul, int, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int> boost::capy::detail::make_when_any_runner<0ul, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int> boost::capy::detail::make_when_any_runner<1ul, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int, int> boost::capy::detail::make_when_any_runner<2ul, int, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int, int>*):
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boost::capy::detail::when_any_runner<int, int, int> boost::capy::detail::make_when_any_runner<0ul, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int>*):
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boost::capy::detail::when_any_runner<int, int, int> boost::capy::detail::make_when_any_runner<1ul, int, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, int>*):
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boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > boost::capy::detail::make_when_any_runner<0ul, int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >(boost::capy::task<int>, boost::capy::detail::when_any_state<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >*):
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boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double> boost::capy::detail::make_when_any_runner<0ul, int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>*):
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boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int> boost::capy::detail::make_when_any_runner<0ul, int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>*):
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boost::capy::detail::when_any_runner<int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int> boost::capy::detail::make_when_any_runner<2ul, int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>*):
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boost::capy::detail::when_any_runner<int, int> boost::capy::detail::make_when_any_runner<0ul, int, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<int>*):
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boost::capy::detail::when_any_runner<int, void, int> boost::capy::detail::make_when_any_runner<1ul, int, void, int>(boost::capy::task<int>, boost::capy::detail::when_any_state<void, int>*):
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boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > boost::capy::detail::make_when_any_runner<1ul, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >(boost::capy::task<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::capy::detail::when_any_state<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >*):
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boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double> boost::capy::detail::make_when_any_runner<1ul, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>(boost::capy::task<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::capy::detail::when_any_state<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>*):
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boost::capy::detail::when_any_runner<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int> boost::capy::detail::make_when_any_runner<1ul, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>(boost::capy::task<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::capy::detail::when_any_state<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>*):
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boost::capy::detail::when_any_runner<void, void, int> boost::capy::detail::make_when_any_runner<0ul, void, void, int>(boost::capy::task<void>, boost::capy::detail::when_any_state<void, int>*):
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boost::capy::detail::when_any_runner<void, void, void, void> boost::capy::detail::make_when_any_runner<0ul, void, void, void, void>(boost::capy::task<void>, boost::capy::detail::when_any_state<void, void, void>*):
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boost::capy::detail::when_any_runner<void, void, void, void> boost::capy::detail::make_when_any_runner<1ul, void, void, void, void>(boost::capy::task<void>, boost::capy::detail::when_any_state<void, void, void>*):
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boost::capy::detail::when_any_runner<void, void, void, void> boost::capy::detail::make_when_any_runner<2ul, void, void, void, void>(boost::capy::task<void>, boost::capy::detail::when_any_state<void, void, void>*):
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|
93 | make_when_any_runner(task<T> inner, when_any_state<Ts...>* state) |
| 650 | { | ||
| 651 | if constexpr (std::is_void_v<T>) | ||
| 652 | { | ||
| 653 | co_await std::move(inner); | ||
| 654 | if(state->try_win(Index)) | ||
| 655 | state->set_winner_void(); // noexcept | ||
| 656 | } | ||
| 657 | else | ||
| 658 | { | ||
| 659 | auto result = co_await std::move(inner); | ||
| 660 | if(state->try_win(Index)) | ||
| 661 | { | ||
| 662 | try | ||
| 663 | { | ||
| 664 | state->set_winner_result(std::move(result)); | ||
| 665 | } | ||
| 666 | catch(...) | ||
| 667 | { | ||
| 668 | state->set_winner_exception(std::current_exception()); | ||
| 669 | } | ||
| 670 | } | ||
| 671 | } | ||
| 672 | 186 | } | |
| 673 | |||
| 674 | /** Awaitable that launches all runner coroutines concurrently. | ||
| 675 | |||
| 676 | Handles the tricky lifetime issue where tasks may complete synchronously | ||
| 677 | during launch, potentially destroying this awaitable's frame before | ||
| 678 | all tasks are extracted from the tuple. See await_suspend for details. | ||
| 679 | |||
| 680 | @tparam Ts The result types of the tasks being launched. | ||
| 681 | */ | ||
| 682 | template<typename... Ts> | ||
| 683 | class when_any_launcher | ||
| 684 | { | ||
| 685 | /** Pointer to tuple of tasks to launch. */ | ||
| 686 | std::tuple<task<Ts>...>* tasks_; | ||
| 687 | |||
| 688 | /** Pointer to shared state for coordination. */ | ||
| 689 | when_any_state<Ts...>* state_; | ||
| 690 | |||
| 691 | public: | ||
| 692 | /** Construct launcher with task tuple and shared state. | ||
| 693 | |||
| 694 | @param tasks Pointer to tuple of tasks (must outlive the await). | ||
| 695 | @param state Pointer to shared state for winner coordination. | ||
| 696 | */ | ||
| 697 | 37 | when_any_launcher( | |
| 698 | std::tuple<task<Ts>...>* tasks, | ||
| 699 | when_any_state<Ts...>* state) | ||
| 700 | 37 | : tasks_(tasks) | |
| 701 | 37 | , state_(state) | |
| 702 | { | ||
| 703 | 37 | } | |
| 704 | |||
| 705 | /** Check if the launcher can complete synchronously. | ||
| 706 | |||
| 707 | @return True only if there are no tasks (degenerate case). | ||
| 708 | */ | ||
| 709 | 37 | bool await_ready() const noexcept | |
| 710 | { | ||
| 711 | 37 | return sizeof...(Ts) == 0; | |
| 712 | } | ||
| 713 | |||
| 714 | /** Launch all runner coroutines and suspend the parent. | ||
| 715 | |||
| 716 | Sets up stop propagation from parent to children, then launches | ||
| 717 | each task in a runner coroutine. Returns noop_coroutine because | ||
| 718 | runners resume the parent via signal_completion(). | ||
| 719 | |||
| 720 | CRITICAL: If the last task finishes synchronously then the parent | ||
| 721 | coroutine resumes, destroying its frame, and destroying this object | ||
| 722 | prior to the completion of await_suspend. Therefore, await_suspend | ||
| 723 | must ensure `this` cannot be referenced after calling `launch_one` | ||
| 724 | for the last time. | ||
| 725 | |||
| 726 | @tparam Ex The executor type. | ||
| 727 | @param continuation Handle to the parent coroutine to resume later. | ||
| 728 | @param caller_ex Executor for dispatching child coroutines. | ||
| 729 | @param parent_token Stop token from the parent for cancellation propagation. | ||
| 730 | @return noop_coroutine; parent is resumed by the last completing task. | ||
| 731 | */ | ||
| 732 | template<typename Ex> | ||
| 733 | 37 | coro await_suspend(coro continuation, Ex const& caller_ex, std::stop_token parent_token = {}) | |
| 734 | { | ||
| 735 | 37 | state_->continuation_ = continuation; | |
| 736 | 37 | state_->caller_ex_ = caller_ex; | |
| 737 | |||
| 738 | // Forward parent's stop requests to children | ||
| 739 |
12/20std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int, int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<void, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<void, void, void>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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|
37 | if(parent_token.stop_possible()) |
| 740 | { | ||
| 741 | 16 | state_->parent_stop_callback_.emplace( | |
| 742 | parent_token, | ||
| 743 | 8 | typename when_any_state<Ts...>::stop_callback_fn{&state_->stop_source_}); | |
| 744 | |||
| 745 |
3/20std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int, int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<void, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<void, void, void>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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|
8 | if(parent_token.stop_requested()) |
| 746 | 2 | state_->stop_source_.request_stop(); | |
| 747 | } | ||
| 748 | |||
| 749 | 37 | auto token = state_->stop_source_.get_token(); | |
| 750 | ✗ | [&]<std::size_t... Is>(std::index_sequence<Is...>) { | |
| 751 | (..., launch_one<Is>(caller_ex, token)); | ||
| 752 |
10/10std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int, int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<void, int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_launcher<void, void, void>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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|
37 | }(std::index_sequence_for<Ts...>{}); |
| 753 | |||
| 754 | 74 | return std::noop_coroutine(); | |
| 755 | 37 | } | |
| 756 | |||
| 757 | /** Resume after all tasks complete. | ||
| 758 | |||
| 759 | No return value; results are accessed via the shared state. | ||
| 760 | */ | ||
| 761 | 37 | void await_resume() const noexcept | |
| 762 | { | ||
| 763 | 37 | } | |
| 764 | |||
| 765 | private: | ||
| 766 | /** Launch a single runner coroutine for task at index I. | ||
| 767 | |||
| 768 | Creates the runner, configures its promise with state and executor, | ||
| 769 | stores its handle for cleanup, and dispatches it for execution. | ||
| 770 | |||
| 771 | @tparam I Compile-time index of the task in the tuple. | ||
| 772 | @tparam Ex The executor type. | ||
| 773 | @param caller_ex Executor for dispatching the runner. | ||
| 774 | @param token Stop token for cooperative cancellation. | ||
| 775 | |||
| 776 | @pre Ex::dispatch() and coro::resume() must not throw. If they do, | ||
| 777 | the coroutine handle may leak. | ||
| 778 | */ | ||
| 779 | template<std::size_t I, typename Ex> | ||
| 780 | 93 | void launch_one(Ex const& caller_ex, std::stop_token token) | |
| 781 | { | ||
| 782 |
31/31void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<3ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<4ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<5ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<6ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<7ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int>::launch_one<3ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<void, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<void, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<void, void, void>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<void, void, void>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<void, void, void>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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|
93 | auto runner = make_when_any_runner<I>( |
| 783 | 93 | std::move(std::get<I>(*tasks_)), state_); | |
| 784 | |||
| 785 | 93 | auto h = runner.release(); | |
| 786 | 93 | h.promise().state_ = state_; | |
| 787 | 93 | h.promise().index_ = I; | |
| 788 | 93 | h.promise().ex_ = caller_ex; | |
| 789 | 93 | h.promise().stop_token_ = token; | |
| 790 | |||
| 791 | 93 | coro ch{h}; | |
| 792 | 93 | state_->runner_handles_[I] = ch; | |
| 793 |
62/62void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<3ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<4ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<5ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<6ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int, int, int, int, int>::launch_one<7ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int, int>::launch_one<3ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int, int>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<void, int>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<void, int>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<void, void, void>::launch_one<0ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<void, void, void>::launch_one<1ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_launcher<void, void, void>::launch_one<2ul, boost::capy::executor_ref>(boost::capy::executor_ref const&, std::stop_token):
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|
93 | caller_ex.dispatch(ch).resume(); |
| 794 | 93 | } | |
| 795 | }; | ||
| 796 | |||
| 797 | } // namespace detail | ||
| 798 | |||
| 799 | /** Wait for the first task to complete. | ||
| 800 | |||
| 801 | Races multiple heterogeneous tasks concurrently and returns when the | ||
| 802 | first one completes. The result includes the winner's index and a | ||
| 803 | deduplicated variant containing the result value. | ||
| 804 | |||
| 805 | @par Example | ||
| 806 | @code | ||
| 807 | task<void> example() { | ||
| 808 | auto [index, result] = co_await when_any( | ||
| 809 | fetch_from_primary(), // task<Response> | ||
| 810 | fetch_from_backup() // task<Response> | ||
| 811 | ); | ||
| 812 | // index is 0 or 1, result holds the winner's Response | ||
| 813 | auto response = std::get<Response>(result); | ||
| 814 | } | ||
| 815 | @endcode | ||
| 816 | |||
| 817 | @tparam T0 First task's result type. | ||
| 818 | @tparam Ts Remaining tasks' result types. | ||
| 819 | @param task0 The first task to race. | ||
| 820 | @param tasks Additional tasks to race concurrently. | ||
| 821 | @return A task yielding a pair of (winner_index, result_variant). | ||
| 822 | |||
| 823 | @par Key Features | ||
| 824 | @li All tasks are launched concurrently | ||
| 825 | @li Returns when first task completes (success or failure) | ||
| 826 | @li Stop is requested for all siblings | ||
| 827 | @li Waits for all siblings to complete before returning | ||
| 828 | @li If winner threw, that exception is rethrown | ||
| 829 | @li Void tasks contribute std::monostate to the variant | ||
| 830 | */ | ||
| 831 | template<typename T0, typename... Ts> | ||
| 832 | [[nodiscard]] task<detail::when_any_result_t<T0, Ts...>> | ||
| 833 |
10/10boost::capy::task<std::pair<unsigned long, boost::capy::detail::deduplicate_impl<std::variant<std::conditional<is_void_v<int>, std::monostate, int>::type>, std::conditional<is_void_v<int>, std::monostate, int>::type, std::conditional<is_void_v<int>, std::monostate, int>::type, std::conditional<is_void_v<int>, std::monostate, int>::type, std::conditional<is_void_v<int>, std::monostate, int>::type, std::conditional<is_void_v<int>, std::monostate, int>::type, std::conditional<is_void_v<int>, std::monostate, int>::type, std::conditional<is_void_v<int>, std::monostate, int>::type>::type> > boost::capy::when_any<int, int, int, int, int, int, int, int>(boost::capy::task<int>, boost::capy::task<int>, boost::capy::task<int>, boost::capy::task<int>, boost::capy::task<int>, boost::capy::task<int>, boost::capy::task<int>, boost::capy::task<int>):
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boost::capy::task<std::pair<unsigned long, boost::capy::detail::deduplicate_impl<std::variant<std::conditional<is_void_v<int>, std::monostate, int>::type>, std::conditional<is_void_v<int>, std::monostate, int>::type, std::conditional<is_void_v<int>, std::monostate, int>::type, std::conditional<is_void_v<int>, std::monostate, int>::type>::type> > boost::capy::when_any<int, int, int, int>(boost::capy::task<int>, boost::capy::task<int>, boost::capy::task<int>, boost::capy::task<int>):
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boost::capy::task<std::pair<unsigned long, boost::capy::detail::deduplicate_impl<std::variant<std::conditional<is_void_v<int>, std::monostate, int>::type>, std::conditional<is_void_v<int>, std::monostate, int>::type, std::conditional<is_void_v<int>, std::monostate, int>::type>::type> > boost::capy::when_any<int, int, int>(boost::capy::task<int>, boost::capy::task<int>, boost::capy::task<int>):
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boost::capy::task<std::pair<unsigned long, boost::capy::detail::deduplicate_impl<std::variant<std::conditional<is_void_v<int>, std::monostate, int>::type>, std::conditional<is_void_v<int>, std::monostate, int>::type>::type> > boost::capy::when_any<int, int>(boost::capy::task<int>, boost::capy::task<int>):
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boost::capy::task<std::pair<unsigned long, boost::capy::detail::deduplicate_impl<std::variant<std::conditional<is_void_v<int>, std::monostate, int>::type>, std::conditional<is_void_v<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::monostate, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::type, std::conditional<is_void_v<double>, std::monostate, double>::type>::type> > boost::capy::when_any<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, double>(boost::capy::task<int>, boost::capy::task<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::capy::task<double>):
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boost::capy::task<std::pair<unsigned long, boost::capy::detail::deduplicate_impl<std::variant<std::conditional<is_void_v<int>, std::monostate, int>::type>, std::conditional<is_void_v<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::monostate, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::type, std::conditional<is_void_v<int>, std::monostate, int>::type>::type> > boost::capy::when_any<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int>(boost::capy::task<int>, boost::capy::task<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::capy::task<int>):
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boost::capy::task<std::pair<unsigned long, boost::capy::detail::deduplicate_impl<std::variant<std::conditional<is_void_v<int>, std::monostate, int>::type>, std::conditional<is_void_v<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::monostate, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::type>::type> > boost::capy::when_any<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >(boost::capy::task<int>, boost::capy::task<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >):
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boost::capy::task<std::pair<unsigned long, boost::capy::detail::deduplicate_impl<std::variant<std::conditional<is_void_v<int>, std::monostate, int>::type>>::type> > boost::capy::when_any<int>(boost::capy::task<int>):
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boost::capy::task<std::pair<unsigned long, boost::capy::detail::deduplicate_impl<std::variant<std::conditional<is_void_v<void>, std::monostate, void>::type>, std::conditional<is_void_v<int>, std::monostate, int>::type>::type> > boost::capy::when_any<void, int>(boost::capy::task<void>, boost::capy::task<int>):
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boost::capy::task<std::pair<unsigned long, boost::capy::detail::deduplicate_impl<std::variant<std::conditional<is_void_v<void>, std::monostate, void>::type>, std::conditional<is_void_v<void>, std::monostate, void>::type, std::conditional<is_void_v<void>, std::monostate, void>::type>::type> > boost::capy::when_any<void, void, void>(boost::capy::task<void>, boost::capy::task<void>, boost::capy::task<void>):
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|
37 | when_any(task<T0> task0, task<Ts>... tasks) |
| 834 | { | ||
| 835 | using result_type = detail::when_any_result_t<T0, Ts...>; | ||
| 836 | |||
| 837 | detail::when_any_state<T0, Ts...> state; | ||
| 838 | std::tuple<task<T0>, task<Ts>...> task_tuple(std::move(task0), std::move(tasks)...); | ||
| 839 | |||
| 840 | co_await detail::when_any_launcher<T0, Ts...>(&task_tuple, &state); | ||
| 841 | |||
| 842 | if(state.winner_exception_) | ||
| 843 | std::rethrow_exception(state.winner_exception_); | ||
| 844 | |||
| 845 | co_return result_type{state.winner_index_, std::move(*state.result_)}; | ||
| 846 | 74 | } | |
| 847 | |||
| 848 | /** Alias for when_any result type, useful for declaring callback signatures. | ||
| 849 | |||
| 850 | Provides a convenient public alias for the internal result type. | ||
| 851 | The result is a pair containing the winner's index and a deduplicated | ||
| 852 | variant holding the result value. | ||
| 853 | |||
| 854 | @par Example | ||
| 855 | @code | ||
| 856 | void on_complete(when_any_result_type<int, std::string> result); | ||
| 857 | @endcode | ||
| 858 | |||
| 859 | @tparam T0 First task's result type. | ||
| 860 | @tparam Ts Remaining tasks' result types. | ||
| 861 | */ | ||
| 862 | template<typename T0, typename... Ts> | ||
| 863 | using when_any_result_type = detail::when_any_result_t<T0, Ts...>; | ||
| 864 | |||
| 865 | namespace detail { | ||
| 866 | |||
| 867 | /** Shared state for homogeneous when_any (vector overload). | ||
| 868 | |||
| 869 | Simpler than the heterogeneous version: uses std::optional<T> instead | ||
| 870 | of variant, and std::vector instead of std::array for runner handles. | ||
| 871 | |||
| 872 | @tparam T The common result type of all tasks. | ||
| 873 | */ | ||
| 874 | template<typename T> | ||
| 875 | struct when_any_homogeneous_state | ||
| 876 | { | ||
| 877 | /** Counter for tasks still running. | ||
| 878 | |||
| 879 | Completion tracking - must wait for ALL tasks for proper cleanup. | ||
| 880 | */ | ||
| 881 | std::atomic<std::size_t> remaining_count_; | ||
| 882 | |||
| 883 | /** Total number of tasks being raced. */ | ||
| 884 | std::size_t task_count_; | ||
| 885 | |||
| 886 | /** Flag indicating whether a winner has been determined. | ||
| 887 | |||
| 888 | Winner tracking - first task to complete claims this. | ||
| 889 | */ | ||
| 890 | std::atomic<bool> has_winner_{false}; | ||
| 891 | |||
| 892 | /** Index of the winning task in the vector. */ | ||
| 893 | std::size_t winner_index_{0}; | ||
| 894 | |||
| 895 | /** Storage for the winner's result value. | ||
| 896 | |||
| 897 | Result storage - simple value, no variant needed. | ||
| 898 | */ | ||
| 899 | std::optional<T> result_; | ||
| 900 | |||
| 901 | /** Exception thrown by the winner, if any. */ | ||
| 902 | std::exception_ptr winner_exception_; | ||
| 903 | |||
| 904 | /** Handles to runner coroutines for cleanup. | ||
| 905 | |||
| 906 | Runner handles - destroyed in destructor. | ||
| 907 | */ | ||
| 908 | std::vector<coro> runner_handles_; | ||
| 909 | |||
| 910 | /** Stop source for cancelling sibling tasks. | ||
| 911 | |||
| 912 | Stop propagation - requested when winner is found. | ||
| 913 | */ | ||
| 914 | std::stop_source stop_source_; | ||
| 915 | |||
| 916 | /** Callback functor that forwards stop requests. | ||
| 917 | |||
| 918 | Connects parent's stop_token to our stop_source. | ||
| 919 | */ | ||
| 920 | struct stop_callback_fn | ||
| 921 | { | ||
| 922 | /** Pointer to the stop source to signal. */ | ||
| 923 | std::stop_source* source_; | ||
| 924 | |||
| 925 | /** Invoke the stop request on the source. */ | ||
| 926 | 2 | void operator()() const noexcept { source_->request_stop(); } | |
| 927 | }; | ||
| 928 | |||
| 929 | /** Type alias for the stop callback registration. */ | ||
| 930 | using stop_callback_t = std::stop_callback<stop_callback_fn>; | ||
| 931 | |||
| 932 | /** Optional callback linking parent's stop token to our stop source. */ | ||
| 933 | std::optional<stop_callback_t> parent_stop_callback_; | ||
| 934 | |||
| 935 | /** Parent coroutine handle to resume when all children complete. */ | ||
| 936 | coro continuation_; | ||
| 937 | |||
| 938 | /** Executor reference for dispatching the parent resumption. */ | ||
| 939 | executor_ref caller_ex_; | ||
| 940 | |||
| 941 | /** Construct state for racing the given number of tasks. | ||
| 942 | |||
| 943 | @param count Number of tasks to race. | ||
| 944 | */ | ||
| 945 | 13 | explicit when_any_homogeneous_state(std::size_t count) | |
| 946 | 13 | : remaining_count_(count) | |
| 947 | 13 | , task_count_(count) | |
| 948 |
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|
39 | , runner_handles_(count) |
| 949 | { | ||
| 950 | 13 | } | |
| 951 | |||
| 952 | /** Destroy state and clean up runner coroutine handles. | ||
| 953 | |||
| 954 | All runners must have completed before destruction. | ||
| 955 | */ | ||
| 956 | 13 | ~when_any_homogeneous_state() | |
| 957 | { | ||
| 958 |
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|
60 | for(auto h : runner_handles_) |
| 959 |
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47 | if(h) |
| 960 | 47 | h.destroy(); | |
| 961 | 13 | } | |
| 962 | |||
| 963 | /** Attempt to become the winner. | ||
| 964 | |||
| 965 | @param index The task's index in the vector. | ||
| 966 | @return true if this task is now the winner, false if another won first. | ||
| 967 | */ | ||
| 968 | 47 | bool try_win(std::size_t index) noexcept | |
| 969 | { | ||
| 970 | 47 | bool expected = false; | |
| 971 |
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|
47 | if(has_winner_.compare_exchange_strong( |
| 972 | expected, true, std::memory_order_acq_rel)) | ||
| 973 | { | ||
| 974 | 13 | winner_index_ = index; | |
| 975 | 13 | stop_source_.request_stop(); | |
| 976 | 13 | return true; | |
| 977 | } | ||
| 978 | 34 | return false; | |
| 979 | } | ||
| 980 | |||
| 981 | /** Store the winner's result. | ||
| 982 | |||
| 983 | @pre Only called by the winner (try_win returned true). | ||
| 984 | */ | ||
| 985 | 11 | void set_winner_result(T value) | |
| 986 | noexcept(std::is_nothrow_move_constructible_v<T>) | ||
| 987 | { | ||
| 988 | 11 | result_.emplace(std::move(value)); | |
| 989 | 11 | } | |
| 990 | |||
| 991 | /** Store the winner's exception. | ||
| 992 | |||
| 993 | @pre Only called by the winner (try_win returned true). | ||
| 994 | */ | ||
| 995 | 2 | void set_winner_exception(std::exception_ptr ep) noexcept | |
| 996 | { | ||
| 997 | 2 | winner_exception_ = ep; | |
| 998 | 2 | } | |
| 999 | |||
| 1000 | /** Signal task completion; last one resumes the parent. | ||
| 1001 | |||
| 1002 | @return Coroutine to resume (parent if last, noop otherwise). | ||
| 1003 | */ | ||
| 1004 | 47 | coro signal_completion() noexcept | |
| 1005 | { | ||
| 1006 | 47 | auto remaining = remaining_count_.fetch_sub(1, std::memory_order_acq_rel); | |
| 1007 |
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|
47 | if(remaining == 1) |
| 1008 | 13 | return caller_ex_.dispatch(continuation_); | |
| 1009 | 34 | return std::noop_coroutine(); | |
| 1010 | } | ||
| 1011 | }; | ||
| 1012 | |||
| 1013 | /** Specialization for void tasks (no result storage needed). | ||
| 1014 | |||
| 1015 | When racing void-returning tasks, there is no result value to store. | ||
| 1016 | Only the winner's index and any exception are tracked. | ||
| 1017 | */ | ||
| 1018 | template<> | ||
| 1019 | struct when_any_homogeneous_state<void> | ||
| 1020 | { | ||
| 1021 | /** Counter for tasks still running. */ | ||
| 1022 | std::atomic<std::size_t> remaining_count_; | ||
| 1023 | |||
| 1024 | /** Total number of tasks being raced. */ | ||
| 1025 | std::size_t task_count_; | ||
| 1026 | |||
| 1027 | /** Flag indicating whether a winner has been determined. */ | ||
| 1028 | std::atomic<bool> has_winner_{false}; | ||
| 1029 | |||
| 1030 | /** Index of the winning task in the vector. */ | ||
| 1031 | std::size_t winner_index_{0}; | ||
| 1032 | |||
| 1033 | /** Exception thrown by the winner, if any. */ | ||
| 1034 | std::exception_ptr winner_exception_; | ||
| 1035 | |||
| 1036 | /** Handles to runner coroutines for cleanup. */ | ||
| 1037 | std::vector<coro> runner_handles_; | ||
| 1038 | |||
| 1039 | /** Stop source for cancelling sibling tasks. */ | ||
| 1040 | std::stop_source stop_source_; | ||
| 1041 | |||
| 1042 | /** Callback functor that forwards stop requests. */ | ||
| 1043 | struct stop_callback_fn | ||
| 1044 | { | ||
| 1045 | /** Pointer to the stop source to signal. */ | ||
| 1046 | std::stop_source* source_; | ||
| 1047 | |||
| 1048 | /** Invoke the stop request on the source. */ | ||
| 1049 | ✗ | void operator()() const noexcept { source_->request_stop(); } | |
| 1050 | }; | ||
| 1051 | |||
| 1052 | /** Type alias for the stop callback registration. */ | ||
| 1053 | using stop_callback_t = std::stop_callback<stop_callback_fn>; | ||
| 1054 | |||
| 1055 | /** Optional callback linking parent's stop token to our stop source. */ | ||
| 1056 | std::optional<stop_callback_t> parent_stop_callback_; | ||
| 1057 | |||
| 1058 | /** Parent coroutine handle to resume when all children complete. */ | ||
| 1059 | coro continuation_; | ||
| 1060 | |||
| 1061 | /** Executor reference for dispatching the parent resumption. */ | ||
| 1062 | executor_ref caller_ex_; | ||
| 1063 | |||
| 1064 | /** Construct state for racing the given number of void tasks. | ||
| 1065 | |||
| 1066 | @param count Number of tasks to race. | ||
| 1067 | */ | ||
| 1068 | 2 | explicit when_any_homogeneous_state(std::size_t count) | |
| 1069 | 2 | : remaining_count_(count) | |
| 1070 | 2 | , task_count_(count) | |
| 1071 |
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|
6 | , runner_handles_(count) |
| 1072 | { | ||
| 1073 | 2 | } | |
| 1074 | |||
| 1075 | /** Destroy state and clean up runner coroutine handles. */ | ||
| 1076 | 2 | ~when_any_homogeneous_state() | |
| 1077 | { | ||
| 1078 |
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7 | for(auto h : runner_handles_) |
| 1079 |
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5 | if(h) |
| 1080 | 5 | h.destroy(); | |
| 1081 | 2 | } | |
| 1082 | |||
| 1083 | /** Attempt to become the winner. | ||
| 1084 | |||
| 1085 | @param index The task's index in the vector. | ||
| 1086 | @return true if this task is now the winner, false if another won first. | ||
| 1087 | */ | ||
| 1088 | 5 | bool try_win(std::size_t index) noexcept | |
| 1089 | { | ||
| 1090 | 5 | bool expected = false; | |
| 1091 |
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5 | if(has_winner_.compare_exchange_strong( |
| 1092 | expected, true, std::memory_order_acq_rel)) | ||
| 1093 | { | ||
| 1094 | 2 | winner_index_ = index; | |
| 1095 | 2 | stop_source_.request_stop(); | |
| 1096 | 2 | return true; | |
| 1097 | } | ||
| 1098 | 3 | return false; | |
| 1099 | } | ||
| 1100 | |||
| 1101 | /** Store the winner's exception. | ||
| 1102 | |||
| 1103 | @pre Only called by the winner (try_win returned true). | ||
| 1104 | */ | ||
| 1105 | 1 | void set_winner_exception(std::exception_ptr ep) noexcept | |
| 1106 | { | ||
| 1107 | 1 | winner_exception_ = ep; | |
| 1108 | 1 | } | |
| 1109 | |||
| 1110 | /** Signal task completion; last one resumes the parent. | ||
| 1111 | |||
| 1112 | @return Coroutine to resume (parent if last, noop otherwise). | ||
| 1113 | */ | ||
| 1114 | 5 | coro signal_completion() noexcept | |
| 1115 | { | ||
| 1116 | 5 | auto remaining = remaining_count_.fetch_sub(1, std::memory_order_acq_rel); | |
| 1117 |
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|
5 | if(remaining == 1) |
| 1118 | 2 | return caller_ex_.dispatch(continuation_); | |
| 1119 | 3 | return std::noop_coroutine(); | |
| 1120 | } | ||
| 1121 | }; | ||
| 1122 | |||
| 1123 | /** Wrapper coroutine for homogeneous when_any tasks (vector overload). | ||
| 1124 | |||
| 1125 | Same role as when_any_runner but uses a runtime index instead of | ||
| 1126 | a compile-time index, allowing it to work with vectors of tasks. | ||
| 1127 | |||
| 1128 | @tparam T The common result type of all tasks. | ||
| 1129 | */ | ||
| 1130 | template<typename T> | ||
| 1131 | struct when_any_homogeneous_runner | ||
| 1132 | { | ||
| 1133 | /** Promise type for the homogeneous runner coroutine. | ||
| 1134 | |||
| 1135 | Manages executor propagation, stop token forwarding, and completion | ||
| 1136 | signaling for the wrapped child task. | ||
| 1137 | */ | ||
| 1138 | struct promise_type : frame_allocating_base | ||
| 1139 | { | ||
| 1140 | /** Pointer to shared state for winner coordination. */ | ||
| 1141 | when_any_homogeneous_state<T>* state_ = nullptr; | ||
| 1142 | |||
| 1143 | /** Runtime index of this task in the vector. */ | ||
| 1144 | std::size_t index_ = 0; | ||
| 1145 | |||
| 1146 | /** Executor reference inherited from the parent coroutine. */ | ||
| 1147 | executor_ref ex_; | ||
| 1148 | |||
| 1149 | /** Stop token for cooperative cancellation. */ | ||
| 1150 | std::stop_token stop_token_; | ||
| 1151 | |||
| 1152 | /** Create the runner coroutine object from this promise. | ||
| 1153 | |||
| 1154 | @return Runner coroutine wrapping this promise's coroutine handle. | ||
| 1155 | */ | ||
| 1156 | 52 | when_any_homogeneous_runner get_return_object() | |
| 1157 | { | ||
| 1158 | return when_any_homogeneous_runner( | ||
| 1159 | 52 | std::coroutine_handle<promise_type>::from_promise(*this)); | |
| 1160 | } | ||
| 1161 | |||
| 1162 | /** Suspend immediately on creation. | ||
| 1163 | |||
| 1164 | Runner coroutines start suspended; the launcher resumes them | ||
| 1165 | after setting up state_, index_, ex_, and stop_token_. | ||
| 1166 | |||
| 1167 | @return Always suspends. | ||
| 1168 | */ | ||
| 1169 | 52 | std::suspend_always initial_suspend() noexcept | |
| 1170 | { | ||
| 1171 | 52 | return {}; | |
| 1172 | } | ||
| 1173 | |||
| 1174 | /** Final suspend awaiter that signals completion to shared state. | ||
| 1175 | |||
| 1176 | @return Custom awaiter that calls signal_completion(). | ||
| 1177 | */ | ||
| 1178 | 52 | auto final_suspend() noexcept | |
| 1179 | { | ||
| 1180 | /** Awaiter that signals task completion and potentially resumes parent. */ | ||
| 1181 | struct awaiter | ||
| 1182 | { | ||
| 1183 | /** Pointer to the promise for accessing shared state. */ | ||
| 1184 | promise_type* p_; | ||
| 1185 | |||
| 1186 | /** Never ready; always suspend to signal completion. | ||
| 1187 | |||
| 1188 | @return Always false. | ||
| 1189 | */ | ||
| 1190 | ✗ | bool await_ready() const noexcept | |
| 1191 | { | ||
| 1192 | ✗ | return false; | |
| 1193 | } | ||
| 1194 | |||
| 1195 | /** Signal completion and return next coroutine to resume. | ||
| 1196 | |||
| 1197 | @return Parent coroutine if this was the last task, noop otherwise. | ||
| 1198 | */ | ||
| 1199 | ✗ | coro await_suspend(coro) noexcept | |
| 1200 | { | ||
| 1201 | ✗ | return p_->state_->signal_completion(); | |
| 1202 | } | ||
| 1203 | |||
| 1204 | /** No-op resume; coroutine is destroyed after final suspend. */ | ||
| 1205 | ✗ | void await_resume() const noexcept | |
| 1206 | { | ||
| 1207 | ✗ | } | |
| 1208 | }; | ||
| 1209 | 52 | return awaiter{this}; | |
| 1210 | } | ||
| 1211 | |||
| 1212 | /** Called when runner coroutine body completes normally. | ||
| 1213 | |||
| 1214 | The actual result handling is done in make_when_any_homogeneous_runner; | ||
| 1215 | this just satisfies the coroutine return requirement. | ||
| 1216 | */ | ||
| 1217 | 49 | void return_void() | |
| 1218 | { | ||
| 1219 | 49 | } | |
| 1220 | |||
| 1221 | /** Handle exceptions thrown by the child task. | ||
| 1222 | |||
| 1223 | Exceptions are valid completions in when_any. If this exception wins, | ||
| 1224 | it will be rethrown to the caller. If another task already won, | ||
| 1225 | this exception is discarded. | ||
| 1226 | */ | ||
| 1227 | 3 | void unhandled_exception() | |
| 1228 | { | ||
| 1229 |
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3 | if(state_->try_win(index_)) |
| 1230 | 3 | state_->set_winner_exception(std::current_exception()); | |
| 1231 | 3 | } | |
| 1232 | |||
| 1233 | /** Awaiter wrapper that injects executor and stop token into child awaitables. | ||
| 1234 | |||
| 1235 | @tparam Awaitable The underlying awaitable type being wrapped. | ||
| 1236 | */ | ||
| 1237 | template<class Awaitable> | ||
| 1238 | struct transform_awaiter | ||
| 1239 | { | ||
| 1240 | /** The wrapped awaitable instance. */ | ||
| 1241 | std::decay_t<Awaitable> a_; | ||
| 1242 | |||
| 1243 | /** Pointer to promise for accessing executor and stop token. */ | ||
| 1244 | promise_type* p_; | ||
| 1245 | |||
| 1246 | /** Check if the underlying awaitable is ready. | ||
| 1247 | |||
| 1248 | @return True if awaitable can complete synchronously. | ||
| 1249 | */ | ||
| 1250 | 52 | bool await_ready() | |
| 1251 | { | ||
| 1252 | 52 | return a_.await_ready(); | |
| 1253 | } | ||
| 1254 | |||
| 1255 | /** Get the result from the underlying awaitable. | ||
| 1256 | |||
| 1257 | @return The awaitable's result value. | ||
| 1258 | */ | ||
| 1259 | 52 | auto await_resume() | |
| 1260 | { | ||
| 1261 | 52 | return a_.await_resume(); | |
| 1262 | } | ||
| 1263 | |||
| 1264 | /** Suspend with executor and stop token injection. | ||
| 1265 | |||
| 1266 | @tparam Promise The suspending coroutine's promise type. | ||
| 1267 | @param h Handle to the suspending coroutine. | ||
| 1268 | @return Coroutine to resume or void. | ||
| 1269 | */ | ||
| 1270 | template<class Promise> | ||
| 1271 | 52 | auto await_suspend(std::coroutine_handle<Promise> h) | |
| 1272 | { | ||
| 1273 |
2/2auto boost::capy::detail::when_any_homogeneous_runner<int>::promise_type::transform_awaiter<boost::capy::task<int> >::await_suspend<boost::capy::detail::when_any_homogeneous_runner<int>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_homogeneous_runner<int>::promise_type>):
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auto boost::capy::detail::when_any_homogeneous_runner<void>::promise_type::transform_awaiter<boost::capy::task<void> >::await_suspend<boost::capy::detail::when_any_homogeneous_runner<void>::promise_type>(std::__n4861::coroutine_handle<boost::capy::detail::when_any_homogeneous_runner<void>::promise_type>):
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|
52 | return a_.await_suspend(h, p_->ex_, p_->stop_token_); |
| 1274 | } | ||
| 1275 | }; | ||
| 1276 | |||
| 1277 | /** Transform awaitables to inject executor and stop token. | ||
| 1278 | |||
| 1279 | @tparam Awaitable The awaitable type being co_awaited. | ||
| 1280 | @param a The awaitable instance. | ||
| 1281 | @return Transformed awaiter with executor/stop_token injection. | ||
| 1282 | */ | ||
| 1283 | template<class Awaitable> | ||
| 1284 | 52 | auto await_transform(Awaitable&& a) | |
| 1285 | { | ||
| 1286 | using A = std::decay_t<Awaitable>; | ||
| 1287 | if constexpr (IoAwaitable<A>) | ||
| 1288 | { | ||
| 1289 | return transform_awaiter<Awaitable>{ | ||
| 1290 | 104 | std::forward<Awaitable>(a), this}; | |
| 1291 | } | ||
| 1292 | else | ||
| 1293 | { | ||
| 1294 | return make_affine(std::forward<Awaitable>(a), ex_); | ||
| 1295 | } | ||
| 1296 | 52 | } | |
| 1297 | }; | ||
| 1298 | |||
| 1299 | /** Handle to the underlying coroutine frame. */ | ||
| 1300 | std::coroutine_handle<promise_type> h_; | ||
| 1301 | |||
| 1302 | /** Construct runner from a coroutine handle. | ||
| 1303 | |||
| 1304 | @param h Handle to the runner coroutine frame. | ||
| 1305 | */ | ||
| 1306 | 52 | explicit when_any_homogeneous_runner(std::coroutine_handle<promise_type> h) noexcept | |
| 1307 | 52 | : h_(h) | |
| 1308 | { | ||
| 1309 | 52 | } | |
| 1310 | |||
| 1311 | /** Move constructor (Clang 14 workaround). | ||
| 1312 | |||
| 1313 | Clang 14 (non-Apple) has a coroutine codegen bug requiring explicit | ||
| 1314 | move constructor; other compilers work correctly with deleted move. | ||
| 1315 | */ | ||
| 1316 | #if defined(__clang__) && __clang_major__ == 14 && !defined(__apple_build_version__) | ||
| 1317 | when_any_homogeneous_runner(when_any_homogeneous_runner&& other) noexcept | ||
| 1318 | : h_(std::exchange(other.h_, nullptr)) {} | ||
| 1319 | #endif | ||
| 1320 | |||
| 1321 | /** Copy construction is not allowed. */ | ||
| 1322 | when_any_homogeneous_runner(when_any_homogeneous_runner const&) = delete; | ||
| 1323 | |||
| 1324 | /** Copy assignment is not allowed. */ | ||
| 1325 | when_any_homogeneous_runner& operator=(when_any_homogeneous_runner const&) = delete; | ||
| 1326 | |||
| 1327 | /** Move construction is deleted (except on Clang 14). */ | ||
| 1328 | #if !defined(__clang__) || __clang_major__ != 14 || defined(__apple_build_version__) | ||
| 1329 | when_any_homogeneous_runner(when_any_homogeneous_runner&&) = delete; | ||
| 1330 | #endif | ||
| 1331 | |||
| 1332 | /** Move assignment is not allowed. */ | ||
| 1333 | when_any_homogeneous_runner& operator=(when_any_homogeneous_runner&&) = delete; | ||
| 1334 | |||
| 1335 | /** Release ownership of the coroutine handle. | ||
| 1336 | |||
| 1337 | @return The coroutine handle; this object becomes empty. | ||
| 1338 | */ | ||
| 1339 | 52 | auto release() noexcept | |
| 1340 | { | ||
| 1341 | 52 | return std::exchange(h_, nullptr); | |
| 1342 | } | ||
| 1343 | }; | ||
| 1344 | |||
| 1345 | /** Create a runner coroutine for a homogeneous when_any task. | ||
| 1346 | |||
| 1347 | Factory function that creates a wrapper coroutine for a child task | ||
| 1348 | in the vector overload. Uses a runtime index instead of compile-time. | ||
| 1349 | |||
| 1350 | @tparam T The result type of the task being wrapped. | ||
| 1351 | @param inner The task to run (will be moved from). | ||
| 1352 | @param state Shared state for winner coordination. | ||
| 1353 | @param index Runtime index of this task in the vector. | ||
| 1354 | @return Runner coroutine (must be started via resume()). | ||
| 1355 | */ | ||
| 1356 | template<typename T> | ||
| 1357 | when_any_homogeneous_runner<T> | ||
| 1358 |
2/2boost::capy::detail::when_any_homogeneous_runner<int> boost::capy::detail::make_when_any_homogeneous_runner<int>(boost::capy::task<int>, boost::capy::detail::when_any_homogeneous_state<int>*, unsigned long):
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boost::capy::detail::when_any_homogeneous_runner<void> boost::capy::detail::make_when_any_homogeneous_runner<void>(boost::capy::task<void>, boost::capy::detail::when_any_homogeneous_state<void>*, unsigned long):
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|
52 | make_when_any_homogeneous_runner(task<T> inner, when_any_homogeneous_state<T>* state, std::size_t index) |
| 1359 | { | ||
| 1360 | if constexpr (std::is_void_v<T>) | ||
| 1361 | { | ||
| 1362 | co_await std::move(inner); | ||
| 1363 | state->try_win(index); // void tasks have no result to store | ||
| 1364 | } | ||
| 1365 | else | ||
| 1366 | { | ||
| 1367 | auto result = co_await std::move(inner); | ||
| 1368 | if(state->try_win(index)) | ||
| 1369 | { | ||
| 1370 | try | ||
| 1371 | { | ||
| 1372 | state->set_winner_result(std::move(result)); | ||
| 1373 | } | ||
| 1374 | catch(...) | ||
| 1375 | { | ||
| 1376 | state->set_winner_exception(std::current_exception()); | ||
| 1377 | } | ||
| 1378 | } | ||
| 1379 | } | ||
| 1380 | 104 | } | |
| 1381 | |||
| 1382 | /** Awaitable that launches all runners for homogeneous when_any. | ||
| 1383 | |||
| 1384 | Same lifetime concerns as when_any_launcher; see its documentation. | ||
| 1385 | Uses runtime iteration over the task vector instead of compile-time | ||
| 1386 | expansion over a tuple. | ||
| 1387 | |||
| 1388 | @tparam T The common result type of all tasks in the vector. | ||
| 1389 | */ | ||
| 1390 | template<typename T> | ||
| 1391 | class when_any_homogeneous_launcher | ||
| 1392 | { | ||
| 1393 | /** Pointer to vector of tasks to launch. */ | ||
| 1394 | std::vector<task<T>>* tasks_; | ||
| 1395 | |||
| 1396 | /** Pointer to shared state for coordination. */ | ||
| 1397 | when_any_homogeneous_state<T>* state_; | ||
| 1398 | |||
| 1399 | public: | ||
| 1400 | /** Construct launcher with task vector and shared state. | ||
| 1401 | |||
| 1402 | @param tasks Pointer to vector of tasks (must outlive the await). | ||
| 1403 | @param state Pointer to shared state for winner coordination. | ||
| 1404 | */ | ||
| 1405 | 15 | when_any_homogeneous_launcher( | |
| 1406 | std::vector<task<T>>* tasks, | ||
| 1407 | when_any_homogeneous_state<T>* state) | ||
| 1408 | 15 | : tasks_(tasks) | |
| 1409 | 15 | , state_(state) | |
| 1410 | { | ||
| 1411 | 15 | } | |
| 1412 | |||
| 1413 | /** Check if the launcher can complete synchronously. | ||
| 1414 | |||
| 1415 | @return True only if there are no tasks (degenerate case). | ||
| 1416 | */ | ||
| 1417 | 15 | bool await_ready() const noexcept | |
| 1418 | { | ||
| 1419 | 15 | return tasks_->empty(); | |
| 1420 | } | ||
| 1421 | |||
| 1422 | /** Launch all runner coroutines and suspend the parent. | ||
| 1423 | |||
| 1424 | Sets up stop propagation from parent to children, then launches | ||
| 1425 | each task in a runner coroutine. Returns noop_coroutine because | ||
| 1426 | runners resume the parent via signal_completion(). | ||
| 1427 | |||
| 1428 | CRITICAL: If the last task finishes synchronously then the parent | ||
| 1429 | coroutine resumes, destroying its frame, and destroying this object | ||
| 1430 | prior to the completion of await_suspend. Therefore, await_suspend | ||
| 1431 | must ensure `this` cannot be referenced after calling `launch_one` | ||
| 1432 | for the last time. | ||
| 1433 | |||
| 1434 | @tparam Ex The executor type. | ||
| 1435 | @param continuation Handle to the parent coroutine to resume later. | ||
| 1436 | @param caller_ex Executor for dispatching child coroutines. | ||
| 1437 | @param parent_token Stop token from the parent for cancellation propagation. | ||
| 1438 | @return noop_coroutine; parent is resumed by the last completing task. | ||
| 1439 | */ | ||
| 1440 | template<typename Ex> | ||
| 1441 | 15 | coro await_suspend(coro continuation, Ex const& caller_ex, std::stop_token parent_token = {}) | |
| 1442 | { | ||
| 1443 | 15 | state_->continuation_ = continuation; | |
| 1444 | 15 | state_->caller_ex_ = caller_ex; | |
| 1445 | |||
| 1446 | // Forward parent's stop requests to children | ||
| 1447 |
3/4std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_homogeneous_launcher<int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_homogeneous_launcher<void>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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15 | if(parent_token.stop_possible()) |
| 1448 | { | ||
| 1449 | 10 | state_->parent_stop_callback_.emplace( | |
| 1450 | parent_token, | ||
| 1451 | 5 | typename when_any_homogeneous_state<T>::stop_callback_fn{&state_->stop_source_}); | |
| 1452 | |||
| 1453 |
2/4std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_homogeneous_launcher<int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_homogeneous_launcher<void>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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5 | if(parent_token.stop_requested()) |
| 1454 | 2 | state_->stop_source_.request_stop(); | |
| 1455 | } | ||
| 1456 | |||
| 1457 | 15 | auto num_tasks = tasks_->size(); | |
| 1458 | 15 | auto token = state_->stop_source_.get_token(); | |
| 1459 |
4/4std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_homogeneous_launcher<int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_homogeneous_launcher<void>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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|
67 | for(std::size_t i = 0; i < num_tasks; ++i) |
| 1460 |
2/2std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_homogeneous_launcher<int>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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std::__n4861::coroutine_handle<void> boost::capy::detail::when_any_homogeneous_launcher<void>::await_suspend<boost::capy::executor_ref>(std::__n4861::coroutine_handle<void>, boost::capy::executor_ref const&, std::stop_token):
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|
52 | launch_one( i, caller_ex, token); |
| 1461 | |||
| 1462 | 30 | return std::noop_coroutine(); | |
| 1463 | 15 | } | |
| 1464 | |||
| 1465 | /** Resume after all tasks complete. | ||
| 1466 | |||
| 1467 | No return value; results are accessed via the shared state. | ||
| 1468 | */ | ||
| 1469 | 15 | void await_resume() const noexcept | |
| 1470 | { | ||
| 1471 | 15 | } | |
| 1472 | |||
| 1473 | private: | ||
| 1474 | /** Launch a single runner coroutine for task at the given index. | ||
| 1475 | |||
| 1476 | Creates the runner, configures its promise with state and executor, | ||
| 1477 | stores its handle for cleanup, and dispatches it for execution. | ||
| 1478 | |||
| 1479 | @tparam Ex The executor type. | ||
| 1480 | @param index Runtime index of the task in the vector. | ||
| 1481 | @param caller_ex Executor for dispatching the runner. | ||
| 1482 | @param token Stop token for cooperative cancellation. | ||
| 1483 | |||
| 1484 | @pre Ex::dispatch() and coro::resume() must not throw. If they do, | ||
| 1485 | the coroutine handle may leak. | ||
| 1486 | */ | ||
| 1487 | template<typename Ex> | ||
| 1488 | 52 | void launch_one(std::size_t index, Ex const& caller_ex, std::stop_token token) | |
| 1489 | { | ||
| 1490 |
2/3void boost::capy::detail::when_any_homogeneous_launcher<int>::launch_one<boost::capy::executor_ref>(unsigned long, boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_homogeneous_launcher<void>::launch_one<boost::capy::executor_ref>(unsigned long, boost::capy::executor_ref const&, std::stop_token):
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52 | auto runner = make_when_any_homogeneous_runner( |
| 1491 | 52 | std::move((*tasks_)[index]), state_, index); | |
| 1492 | |||
| 1493 | 52 | auto h = runner.release(); | |
| 1494 | 52 | h.promise().state_ = state_; | |
| 1495 | 52 | h.promise().index_ = index; | |
| 1496 | 52 | h.promise().ex_ = caller_ex; | |
| 1497 | 52 | h.promise().stop_token_ = token; | |
| 1498 | |||
| 1499 | 52 | coro ch{h}; | |
| 1500 | 52 | state_->runner_handles_[index] = ch; | |
| 1501 |
4/4void boost::capy::detail::when_any_homogeneous_launcher<int>::launch_one<boost::capy::executor_ref>(unsigned long, boost::capy::executor_ref const&, std::stop_token):
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void boost::capy::detail::when_any_homogeneous_launcher<void>::launch_one<boost::capy::executor_ref>(unsigned long, boost::capy::executor_ref const&, std::stop_token):
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|
52 | caller_ex.dispatch(ch).resume(); |
| 1502 | 52 | } | |
| 1503 | }; | ||
| 1504 | |||
| 1505 | } // namespace detail | ||
| 1506 | |||
| 1507 | /** Wait for the first task to complete (homogeneous overload). | ||
| 1508 | |||
| 1509 | Races a vector of tasks with the same result type. Simpler than the | ||
| 1510 | heterogeneous overload: returns a direct pair instead of a variant | ||
| 1511 | since all tasks share the same type. | ||
| 1512 | |||
| 1513 | @par Example | ||
| 1514 | @code | ||
| 1515 | task<void> example() { | ||
| 1516 | std::vector<task<Response>> requests; | ||
| 1517 | requests.push_back(fetch_from_server(0)); | ||
| 1518 | requests.push_back(fetch_from_server(1)); | ||
| 1519 | requests.push_back(fetch_from_server(2)); | ||
| 1520 | |||
| 1521 | auto [index, response] = co_await when_any(std::move(requests)); | ||
| 1522 | // index is 0, 1, or 2; response is the winner's Response | ||
| 1523 | } | ||
| 1524 | @endcode | ||
| 1525 | |||
| 1526 | @tparam T The common result type of all tasks (must not be void). | ||
| 1527 | @param tasks Vector of tasks to race concurrently (must not be empty). | ||
| 1528 | @return A task yielding a pair of (winner_index, result). | ||
| 1529 | @throws std::invalid_argument if tasks is empty. | ||
| 1530 | |||
| 1531 | @par Key Features | ||
| 1532 | @li All tasks are launched concurrently | ||
| 1533 | @li Returns when first task completes (success or failure) | ||
| 1534 | @li Stop is requested for all siblings | ||
| 1535 | @li Waits for all siblings to complete before returning | ||
| 1536 | @li If winner threw, that exception is rethrown | ||
| 1537 | @li Returns simple pair (no variant needed for homogeneous types) | ||
| 1538 | */ | ||
| 1539 | template<typename T> | ||
| 1540 | requires (!std::is_void_v<T>) | ||
| 1541 | [[nodiscard]] task<std::pair<std::size_t, T>> | ||
| 1542 |
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|
14 | when_any(std::vector<task<T>> tasks) |
| 1543 | { | ||
| 1544 | if(tasks.empty()) | ||
| 1545 | throw std::invalid_argument("when_any requires at least one task"); | ||
| 1546 | |||
| 1547 | using result_type = std::pair<std::size_t, T>; | ||
| 1548 | |||
| 1549 | detail::when_any_homogeneous_state<T> state(tasks.size()); | ||
| 1550 | |||
| 1551 | co_await detail::when_any_homogeneous_launcher<T>(&tasks, &state); | ||
| 1552 | |||
| 1553 | if(state.winner_exception_) | ||
| 1554 | std::rethrow_exception(state.winner_exception_); | ||
| 1555 | |||
| 1556 | co_return result_type{state.winner_index_, std::move(*state.result_)}; | ||
| 1557 | 28 | } | |
| 1558 | |||
| 1559 | /** Wait for the first task to complete (homogeneous void overload). | ||
| 1560 | |||
| 1561 | Races a vector of void-returning tasks. Since void tasks have no | ||
| 1562 | result value, only the winner's index is returned. | ||
| 1563 | |||
| 1564 | @param tasks Vector of void tasks to race concurrently (must not be empty). | ||
| 1565 | @return A task yielding the winner's index (zero-based). | ||
| 1566 | @throws std::invalid_argument if tasks is empty. | ||
| 1567 | |||
| 1568 | @par Key Features | ||
| 1569 | @li All tasks are launched concurrently | ||
| 1570 | @li Returns when first task completes (success or failure) | ||
| 1571 | @li Stop is requested for all siblings | ||
| 1572 | @li Waits for all siblings to complete before returning | ||
| 1573 | @li If winner threw, that exception is rethrown | ||
| 1574 | */ | ||
| 1575 | [[nodiscard]] inline task<std::size_t> | ||
| 1576 |
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|
2 | when_any(std::vector<task<void>> tasks) |
| 1577 | { | ||
| 1578 | if(tasks.empty()) | ||
| 1579 | throw std::invalid_argument("when_any requires at least one task"); | ||
| 1580 | |||
| 1581 | detail::when_any_homogeneous_state<void> state(tasks.size()); | ||
| 1582 | |||
| 1583 | co_await detail::when_any_homogeneous_launcher<void>(&tasks, &state); | ||
| 1584 | |||
| 1585 | if(state.winner_exception_) | ||
| 1586 | std::rethrow_exception(state.winner_exception_); | ||
| 1587 | |||
| 1588 | co_return state.winner_index_; | ||
| 1589 | 4 | } | |
| 1590 | |||
| 1591 | /** Alias for vector when_any result type. | ||
| 1592 | |||
| 1593 | For homogeneous when_any (vector overload), the result is simpler: | ||
| 1594 | a pair of the winner's index and the result value directly (no variant | ||
| 1595 | needed since all tasks share the same type). | ||
| 1596 | |||
| 1597 | @par Example | ||
| 1598 | @code | ||
| 1599 | void on_complete(when_any_vector_result_type<Response> result); | ||
| 1600 | @endcode | ||
| 1601 | |||
| 1602 | @tparam T The common result type of all tasks in the vector. | ||
| 1603 | */ | ||
| 1604 | template<typename T> | ||
| 1605 | using when_any_vector_result_type = std::pair<std::size_t, T>; | ||
| 1606 | |||
| 1607 | } // namespace capy | ||
| 1608 | } // namespace boost | ||
| 1609 | |||
| 1610 | #endif | ||
| 1611 |