Andrew Hsieh | 0207508 | 2012-03-06 14:06:15 -0800 | [diff] [blame] | 1 | // <future> -*- C++ -*- |
| 2 | |
| 3 | // Copyright (C) 2009, 2010, 2011 Free Software Foundation, Inc. |
| 4 | // |
| 5 | // This file is part of the GNU ISO C++ Library. This library is free |
| 6 | // software; you can redistribute it and/or modify it under the |
| 7 | // terms of the GNU General Public License as published by the |
| 8 | // Free Software Foundation; either version 3, or (at your option) |
| 9 | // any later version. |
| 10 | |
| 11 | // This library is distributed in the hope that it will be useful, |
| 12 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | // GNU General Public License for more details. |
| 15 | |
| 16 | // Under Section 7 of GPL version 3, you are granted additional |
| 17 | // permissions described in the GCC Runtime Library Exception, version |
| 18 | // 3.1, as published by the Free Software Foundation. |
| 19 | |
| 20 | // You should have received a copy of the GNU General Public License and |
| 21 | // a copy of the GCC Runtime Library Exception along with this program; |
| 22 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| 23 | // <http://www.gnu.org/licenses/>. |
| 24 | |
| 25 | /** @file include/future |
| 26 | * This is a Standard C++ Library header. |
| 27 | */ |
| 28 | |
| 29 | #ifndef _GLIBCXX_FUTURE |
| 30 | #define _GLIBCXX_FUTURE 1 |
| 31 | |
| 32 | #pragma GCC system_header |
| 33 | |
| 34 | #ifndef __GXX_EXPERIMENTAL_CXX0X__ |
| 35 | # include <bits/c++0x_warning.h> |
| 36 | #else |
| 37 | |
| 38 | #include <functional> |
| 39 | #include <memory> |
| 40 | #include <mutex> |
| 41 | #include <thread> |
| 42 | #include <condition_variable> |
| 43 | #include <system_error> |
| 44 | #include <exception> |
| 45 | #include <atomic> |
| 46 | #include <bits/functexcept.h> |
| 47 | |
| 48 | namespace std _GLIBCXX_VISIBILITY(default) |
| 49 | { |
| 50 | _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| 51 | |
| 52 | /** |
| 53 | * @defgroup futures Futures |
| 54 | * @ingroup concurrency |
| 55 | * |
| 56 | * Classes for futures support. |
| 57 | * @{ |
| 58 | */ |
| 59 | |
| 60 | /// Error code for futures |
| 61 | enum class future_errc |
| 62 | { |
| 63 | broken_promise, |
| 64 | future_already_retrieved, |
| 65 | promise_already_satisfied, |
| 66 | no_state |
| 67 | }; |
| 68 | |
| 69 | /// Specialization. |
| 70 | template<> |
| 71 | struct is_error_code_enum<future_errc> : public true_type { }; |
| 72 | |
| 73 | /// Points to a statically-allocated object derived from error_category. |
| 74 | const error_category& |
| 75 | future_category(); |
| 76 | |
| 77 | /// Overload for make_error_code. |
| 78 | inline error_code |
| 79 | make_error_code(future_errc __errc) |
| 80 | { return error_code(static_cast<int>(__errc), future_category()); } |
| 81 | |
| 82 | /// Overload for make_error_condition. |
| 83 | inline error_condition |
| 84 | make_error_condition(future_errc __errc) |
| 85 | { return error_condition(static_cast<int>(__errc), future_category()); } |
| 86 | |
| 87 | /** |
| 88 | * @brief Exception type thrown by futures. |
| 89 | * @ingroup exceptions |
| 90 | */ |
| 91 | class future_error : public logic_error |
| 92 | { |
| 93 | error_code _M_code; |
| 94 | |
| 95 | public: |
| 96 | explicit future_error(error_code __ec) |
| 97 | : logic_error("std::future_error"), _M_code(__ec) |
| 98 | { } |
| 99 | |
| 100 | virtual ~future_error() throw(); |
| 101 | |
| 102 | virtual const char* |
| 103 | what() const throw(); |
| 104 | |
| 105 | const error_code& |
| 106 | code() const throw() { return _M_code; } |
| 107 | }; |
| 108 | |
| 109 | // Forward declarations. |
| 110 | template<typename _Res> |
| 111 | class future; |
| 112 | |
| 113 | template<typename _Res> |
| 114 | class shared_future; |
| 115 | |
| 116 | template<typename _Res> |
| 117 | class atomic_future; |
| 118 | |
| 119 | template<typename _Signature> |
| 120 | class packaged_task; |
| 121 | |
| 122 | template<typename _Res> |
| 123 | class promise; |
| 124 | |
| 125 | /// Launch code for futures |
| 126 | enum class launch |
| 127 | { |
| 128 | any, |
| 129 | async, |
| 130 | sync |
| 131 | }; |
| 132 | |
| 133 | /// Status code for futures |
| 134 | enum class future_status |
| 135 | { |
| 136 | ready, |
| 137 | timeout, |
| 138 | deferred |
| 139 | }; |
| 140 | |
| 141 | template<typename _Fn, typename... _Args> |
| 142 | future<typename result_of<_Fn(_Args...)>::type> |
| 143 | async(launch __policy, _Fn&& __fn, _Args&&... __args); |
| 144 | |
| 145 | template<typename _FnCheck, typename _Fn, typename... _Args> |
| 146 | struct __async_sfinae_helper |
| 147 | { |
| 148 | typedef future<typename result_of<_Fn(_Args...)>::type> type; |
| 149 | }; |
| 150 | |
| 151 | template<typename _Fn, typename... _Args> |
| 152 | struct __async_sfinae_helper<launch, _Fn, _Args...> |
| 153 | { }; |
| 154 | |
| 155 | template<typename _Fn, typename... _Args> |
| 156 | typename |
| 157 | __async_sfinae_helper<typename decay<_Fn>::type, _Fn, _Args...>::type |
| 158 | async(_Fn&& __fn, _Args&&... __args); |
| 159 | |
| 160 | #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1) \ |
| 161 | && defined(_GLIBCXX_ATOMIC_BUILTINS_4) |
| 162 | |
| 163 | /// Base class and enclosing scope. |
| 164 | struct __future_base |
| 165 | { |
| 166 | /// Base class for results. |
| 167 | struct _Result_base |
| 168 | { |
| 169 | exception_ptr _M_error; |
| 170 | |
| 171 | _Result_base(const _Result_base&) = delete; |
| 172 | _Result_base& operator=(const _Result_base&) = delete; |
| 173 | |
| 174 | // _M_destroy() allows derived classes to control deallocation |
| 175 | virtual void _M_destroy() = 0; |
| 176 | |
| 177 | struct _Deleter |
| 178 | { |
| 179 | void operator()(_Result_base* __fr) const { __fr->_M_destroy(); } |
| 180 | }; |
| 181 | |
| 182 | protected: |
| 183 | _Result_base(); |
| 184 | virtual ~_Result_base(); |
| 185 | }; |
| 186 | |
| 187 | /// Result. |
| 188 | template<typename _Res> |
| 189 | struct _Result : _Result_base |
| 190 | { |
| 191 | private: |
| 192 | typedef alignment_of<_Res> __a_of; |
| 193 | typedef aligned_storage<sizeof(_Res), __a_of::value> __align_storage; |
| 194 | typedef typename __align_storage::type __align_type; |
| 195 | |
| 196 | __align_type _M_storage; |
| 197 | bool _M_initialized; |
| 198 | |
| 199 | public: |
| 200 | _Result() : _M_initialized() { } |
| 201 | |
| 202 | ~_Result() |
| 203 | { |
| 204 | if (_M_initialized) |
| 205 | _M_value().~_Res(); |
| 206 | } |
| 207 | |
| 208 | // Return lvalue, future will add const or rvalue-reference |
| 209 | _Res& |
| 210 | _M_value() { return *static_cast<_Res*>(_M_addr()); } |
| 211 | |
| 212 | void |
| 213 | _M_set(const _Res& __res) |
| 214 | { |
| 215 | ::new (_M_addr()) _Res(__res); |
| 216 | _M_initialized = true; |
| 217 | } |
| 218 | |
| 219 | void |
| 220 | _M_set(_Res&& __res) |
| 221 | { |
| 222 | ::new (_M_addr()) _Res(std::move(__res)); |
| 223 | _M_initialized = true; |
| 224 | } |
| 225 | |
| 226 | private: |
| 227 | void _M_destroy() { delete this; } |
| 228 | |
| 229 | void* _M_addr() { return static_cast<void*>(&_M_storage); } |
| 230 | }; |
| 231 | |
| 232 | // TODO: use template alias when available |
| 233 | /* |
| 234 | template<typename _Res> |
| 235 | using _Ptr = unique_ptr<_Res, _Result_base::_Deleter>; |
| 236 | */ |
| 237 | /// A unique_ptr based on the instantiating type. |
| 238 | template<typename _Res> |
| 239 | struct _Ptr |
| 240 | { |
| 241 | typedef unique_ptr<_Res, _Result_base::_Deleter> type; |
| 242 | }; |
| 243 | |
| 244 | /// Result_alloc. |
| 245 | template<typename _Res, typename _Alloc> |
| 246 | struct _Result_alloc : _Result<_Res>, _Alloc |
| 247 | { |
| 248 | typedef typename _Alloc::template rebind<_Result_alloc>::other |
| 249 | __allocator_type; |
| 250 | |
| 251 | explicit |
| 252 | _Result_alloc(const _Alloc& __a) : _Result<_Res>(), _Alloc(__a) |
| 253 | { } |
| 254 | |
| 255 | private: |
| 256 | void _M_destroy() |
| 257 | { |
| 258 | __allocator_type __a(*this); |
| 259 | __a.destroy(this); |
| 260 | __a.deallocate(this, 1); |
| 261 | } |
| 262 | }; |
| 263 | |
| 264 | template<typename _Res, typename _Allocator> |
| 265 | static typename _Ptr<_Result_alloc<_Res, _Allocator>>::type |
| 266 | _S_allocate_result(const _Allocator& __a) |
| 267 | { |
| 268 | typedef _Result_alloc<_Res, _Allocator> __result_type; |
| 269 | typename __result_type::__allocator_type __a2(__a); |
| 270 | __result_type* __p = __a2.allocate(1); |
| 271 | __try |
| 272 | { |
| 273 | __a2.construct(__p, __a); |
| 274 | } |
| 275 | __catch(...) |
| 276 | { |
| 277 | __a2.deallocate(__p, 1); |
| 278 | __throw_exception_again; |
| 279 | } |
| 280 | return typename _Ptr<__result_type>::type(__p); |
| 281 | } |
| 282 | |
| 283 | |
| 284 | /// Base class for state between a promise and one or more |
| 285 | /// associated futures. |
| 286 | class _State_base |
| 287 | { |
| 288 | typedef _Ptr<_Result_base>::type _Ptr_type; |
| 289 | |
| 290 | _Ptr_type _M_result; |
| 291 | mutex _M_mutex; |
| 292 | condition_variable _M_cond; |
| 293 | atomic_flag _M_retrieved; |
| 294 | once_flag _M_once; |
| 295 | |
| 296 | public: |
| 297 | _State_base() : _M_result(), _M_retrieved(ATOMIC_FLAG_INIT) { } |
| 298 | _State_base(const _State_base&) = delete; |
| 299 | _State_base& operator=(const _State_base&) = delete; |
| 300 | virtual ~_State_base(); |
| 301 | |
| 302 | _Result_base& |
| 303 | wait() |
| 304 | { |
| 305 | _M_run_deferred(); |
| 306 | unique_lock<mutex> __lock(_M_mutex); |
| 307 | if (!_M_ready()) |
| 308 | _M_cond.wait(__lock, std::bind<bool>(&_State_base::_M_ready, this)); |
| 309 | return *_M_result; |
| 310 | } |
| 311 | |
| 312 | template<typename _Rep, typename _Period> |
| 313 | bool |
| 314 | wait_for(const chrono::duration<_Rep, _Period>& __rel) |
| 315 | { |
| 316 | unique_lock<mutex> __lock(_M_mutex); |
| 317 | auto __bound = std::bind<bool>(&_State_base::_M_ready, this); |
| 318 | return _M_ready() || _M_cond.wait_for(__lock, __rel, __bound); |
| 319 | } |
| 320 | |
| 321 | template<typename _Clock, typename _Duration> |
| 322 | bool |
| 323 | wait_until(const chrono::time_point<_Clock, _Duration>& __abs) |
| 324 | { |
| 325 | unique_lock<mutex> __lock(_M_mutex); |
| 326 | auto __bound = std::bind<bool>(&_State_base::_M_ready, this); |
| 327 | return _M_ready() || _M_cond.wait_until(__lock, __abs, __bound); |
| 328 | } |
| 329 | |
| 330 | void |
| 331 | _M_set_result(function<_Ptr_type()> __res, bool __ignore_failure = false) |
| 332 | { |
| 333 | bool __set = __ignore_failure; |
| 334 | // all calls to this function are serialized, |
| 335 | // side-effects of invoking __res only happen once |
| 336 | call_once(_M_once, &_State_base::_M_do_set, this, ref(__res), |
| 337 | ref(__set)); |
| 338 | if (!__set) |
| 339 | __throw_future_error(int(future_errc::promise_already_satisfied)); |
| 340 | } |
| 341 | |
| 342 | void |
| 343 | _M_break_promise(_Ptr_type __res) |
| 344 | { |
| 345 | if (static_cast<bool>(__res)) |
| 346 | { |
| 347 | error_code __ec(make_error_code(future_errc::broken_promise)); |
| 348 | __res->_M_error = copy_exception(future_error(__ec)); |
| 349 | { |
| 350 | lock_guard<mutex> __lock(_M_mutex); |
| 351 | _M_result.swap(__res); |
| 352 | } |
| 353 | _M_cond.notify_all(); |
| 354 | } |
| 355 | } |
| 356 | |
| 357 | // Called when this object is passed to a future. |
| 358 | void |
| 359 | _M_set_retrieved_flag() |
| 360 | { |
| 361 | if (_M_retrieved.test_and_set()) |
| 362 | __throw_future_error(int(future_errc::future_already_retrieved)); |
| 363 | } |
| 364 | |
| 365 | template<typename _Res, typename _Arg> |
| 366 | struct _Setter; |
| 367 | |
| 368 | // set lvalues |
| 369 | template<typename _Res, typename _Arg> |
| 370 | struct _Setter<_Res, _Arg&> |
| 371 | { |
| 372 | // check this is only used by promise<R>::set_value(const R&) |
| 373 | // or promise<R>::set_value(R&) |
| 374 | static_assert(is_same<_Res, _Arg&>::value // promise<R&> |
| 375 | || is_same<const _Res, _Arg>::value, // promise<R> |
| 376 | "Invalid specialisation"); |
| 377 | |
| 378 | typename promise<_Res>::_Ptr_type operator()() |
| 379 | { |
| 380 | _State_base::_S_check(_M_promise->_M_future); |
| 381 | _M_promise->_M_storage->_M_set(_M_arg); |
| 382 | return std::move(_M_promise->_M_storage); |
| 383 | } |
| 384 | promise<_Res>* _M_promise; |
| 385 | _Arg& _M_arg; |
| 386 | }; |
| 387 | |
| 388 | // set rvalues |
| 389 | template<typename _Res> |
| 390 | struct _Setter<_Res, _Res&&> |
| 391 | { |
| 392 | typename promise<_Res>::_Ptr_type operator()() |
| 393 | { |
| 394 | _State_base::_S_check(_M_promise->_M_future); |
| 395 | _M_promise->_M_storage->_M_set(std::move(_M_arg)); |
| 396 | return std::move(_M_promise->_M_storage); |
| 397 | } |
| 398 | promise<_Res>* _M_promise; |
| 399 | _Res& _M_arg; |
| 400 | }; |
| 401 | |
| 402 | struct __exception_ptr_tag { }; |
| 403 | |
| 404 | // set exceptions |
| 405 | template<typename _Res> |
| 406 | struct _Setter<_Res, __exception_ptr_tag> |
| 407 | { |
| 408 | typename promise<_Res>::_Ptr_type operator()() |
| 409 | { |
| 410 | _State_base::_S_check(_M_promise->_M_future); |
| 411 | _M_promise->_M_storage->_M_error = _M_ex; |
| 412 | return std::move(_M_promise->_M_storage); |
| 413 | } |
| 414 | |
| 415 | promise<_Res>* _M_promise; |
| 416 | exception_ptr& _M_ex; |
| 417 | }; |
| 418 | |
| 419 | template<typename _Res, typename _Arg> |
| 420 | static _Setter<_Res, _Arg&&> |
| 421 | __setter(promise<_Res>* __prom, _Arg&& __arg) |
| 422 | { |
| 423 | return _Setter<_Res, _Arg&&>{ __prom, __arg }; |
| 424 | } |
| 425 | |
| 426 | template<typename _Res> |
| 427 | static _Setter<_Res, __exception_ptr_tag> |
| 428 | __setter(exception_ptr& __ex, promise<_Res>* __prom) |
| 429 | { |
| 430 | return _Setter<_Res, __exception_ptr_tag>{ __prom, __ex }; |
| 431 | } |
| 432 | |
| 433 | static _Setter<void, void> |
| 434 | __setter(promise<void>* __prom); |
| 435 | |
| 436 | template<typename _Tp> |
| 437 | static bool |
| 438 | _S_check(const shared_ptr<_Tp>& __p) |
| 439 | { |
| 440 | if (!static_cast<bool>(__p)) |
| 441 | __throw_future_error((int)future_errc::no_state); |
| 442 | } |
| 443 | |
| 444 | private: |
| 445 | void |
| 446 | _M_do_set(function<_Ptr_type()>& __f, bool& __set) |
| 447 | { |
| 448 | _Ptr_type __res = __f(); |
| 449 | { |
| 450 | lock_guard<mutex> __lock(_M_mutex); |
| 451 | _M_result.swap(__res); |
| 452 | } |
| 453 | _M_cond.notify_all(); |
| 454 | __set = true; |
| 455 | } |
| 456 | |
| 457 | bool _M_ready() const { return static_cast<bool>(_M_result); } |
| 458 | |
| 459 | virtual void _M_run_deferred() { } |
| 460 | }; |
| 461 | |
| 462 | template<typename _Res> |
| 463 | class _Deferred_state; |
| 464 | |
| 465 | template<typename _Res> |
| 466 | class _Async_state; |
| 467 | |
| 468 | template<typename _Signature> |
| 469 | class _Task_state; |
| 470 | |
| 471 | template<typename _StateT, typename _Res = typename _StateT::_Res_type> |
| 472 | struct _Task_setter; |
| 473 | }; |
| 474 | |
| 475 | /// Partial specialization for reference types. |
| 476 | template<typename _Res> |
| 477 | struct __future_base::_Result<_Res&> : __future_base::_Result_base |
| 478 | { |
| 479 | _Result() : _M_value_ptr() { } |
| 480 | |
| 481 | void _M_set(_Res& __res) { _M_value_ptr = &__res; } |
| 482 | |
| 483 | _Res& _M_get() { return *_M_value_ptr; } |
| 484 | |
| 485 | private: |
| 486 | _Res* _M_value_ptr; |
| 487 | |
| 488 | void _M_destroy() { delete this; } |
| 489 | }; |
| 490 | |
| 491 | /// Explicit specialization for void. |
| 492 | template<> |
| 493 | struct __future_base::_Result<void> : __future_base::_Result_base |
| 494 | { |
| 495 | private: |
| 496 | void _M_destroy() { delete this; } |
| 497 | }; |
| 498 | |
| 499 | |
| 500 | /// Common implementation for future and shared_future. |
| 501 | template<typename _Res> |
| 502 | class __basic_future : public __future_base |
| 503 | { |
| 504 | protected: |
| 505 | typedef shared_ptr<_State_base> __state_type; |
| 506 | typedef __future_base::_Result<_Res>& __result_type; |
| 507 | |
| 508 | private: |
| 509 | __state_type _M_state; |
| 510 | |
| 511 | public: |
| 512 | // Disable copying. |
| 513 | __basic_future(const __basic_future&) = delete; |
| 514 | __basic_future& operator=(const __basic_future&) = delete; |
| 515 | |
| 516 | bool |
| 517 | valid() const { return static_cast<bool>(_M_state); } |
| 518 | |
| 519 | void |
| 520 | wait() const |
| 521 | { |
| 522 | _State_base::_S_check(_M_state); |
| 523 | _M_state->wait(); |
| 524 | } |
| 525 | |
| 526 | template<typename _Rep, typename _Period> |
| 527 | bool |
| 528 | wait_for(const chrono::duration<_Rep, _Period>& __rel) const |
| 529 | { |
| 530 | _State_base::_S_check(_M_state); |
| 531 | return _M_state->wait_for(__rel); |
| 532 | } |
| 533 | |
| 534 | template<typename _Clock, typename _Duration> |
| 535 | bool |
| 536 | wait_until(const chrono::time_point<_Clock, _Duration>& __abs) const |
| 537 | { |
| 538 | _State_base::_S_check(_M_state); |
| 539 | return _M_state->wait_until(__abs); |
| 540 | } |
| 541 | |
| 542 | protected: |
| 543 | /// Wait for the state to be ready and rethrow any stored exception |
| 544 | __result_type |
| 545 | _M_get_result() |
| 546 | { |
| 547 | _State_base::_S_check(_M_state); |
| 548 | _Result_base& __res = _M_state->wait(); |
| 549 | if (!(__res._M_error == 0)) |
| 550 | rethrow_exception(__res._M_error); |
| 551 | return static_cast<__result_type>(__res); |
| 552 | } |
| 553 | |
| 554 | void _M_swap(__basic_future& __that) |
| 555 | { |
| 556 | _M_state.swap(__that._M_state); |
| 557 | } |
| 558 | |
| 559 | // Construction of a future by promise::get_future() |
| 560 | explicit |
| 561 | __basic_future(const __state_type& __state) : _M_state(__state) |
| 562 | { |
| 563 | _State_base::_S_check(_M_state); |
| 564 | _M_state->_M_set_retrieved_flag(); |
| 565 | } |
| 566 | |
| 567 | // Copy construction from a shared_future |
| 568 | explicit |
| 569 | __basic_future(const shared_future<_Res>&); |
| 570 | |
| 571 | // Move construction from a shared_future |
| 572 | explicit |
| 573 | __basic_future(shared_future<_Res>&&); |
| 574 | |
| 575 | // Move construction from a future |
| 576 | explicit |
| 577 | __basic_future(future<_Res>&&); |
| 578 | |
| 579 | constexpr __basic_future() : _M_state() { } |
| 580 | |
| 581 | struct _Reset |
| 582 | { |
| 583 | explicit _Reset(__basic_future& __fut) : _M_fut(__fut) { } |
| 584 | ~_Reset() { _M_fut._M_state.reset(); } |
| 585 | __basic_future& _M_fut; |
| 586 | }; |
| 587 | }; |
| 588 | |
| 589 | |
| 590 | /// Primary template for future. |
| 591 | template<typename _Res> |
| 592 | class future : public __basic_future<_Res> |
| 593 | { |
| 594 | friend class promise<_Res>; |
| 595 | template<typename> friend class packaged_task; |
| 596 | template<typename _Fn, typename... _Args> |
| 597 | friend future<typename result_of<_Fn(_Args...)>::type> |
| 598 | async(launch, _Fn&&, _Args&&...); |
| 599 | |
| 600 | typedef __basic_future<_Res> _Base_type; |
| 601 | typedef typename _Base_type::__state_type __state_type; |
| 602 | |
| 603 | explicit |
| 604 | future(const __state_type& __state) : _Base_type(__state) { } |
| 605 | |
| 606 | public: |
| 607 | constexpr future() : _Base_type() { } |
| 608 | |
| 609 | /// Move constructor |
| 610 | future(future&& __uf) : _Base_type(std::move(__uf)) { } |
| 611 | |
| 612 | // Disable copying |
| 613 | future(const future&) = delete; |
| 614 | future& operator=(const future&) = delete; |
| 615 | |
| 616 | future& operator=(future&& __fut) |
| 617 | { |
| 618 | future(std::move(__fut))._M_swap(*this); |
| 619 | return *this; |
| 620 | } |
| 621 | |
| 622 | /// Retrieving the value |
| 623 | _Res |
| 624 | get() |
| 625 | { |
| 626 | typename _Base_type::_Reset __reset(*this); |
| 627 | return std::move(this->_M_get_result()._M_value()); |
| 628 | } |
| 629 | }; |
| 630 | |
| 631 | /// Partial specialization for future<R&> |
| 632 | template<typename _Res> |
| 633 | class future<_Res&> : public __basic_future<_Res&> |
| 634 | { |
| 635 | friend class promise<_Res&>; |
| 636 | template<typename> friend class packaged_task; |
| 637 | template<typename _Fn, typename... _Args> |
| 638 | friend future<typename result_of<_Fn(_Args...)>::type> |
| 639 | async(launch, _Fn&&, _Args&&...); |
| 640 | |
| 641 | typedef __basic_future<_Res&> _Base_type; |
| 642 | typedef typename _Base_type::__state_type __state_type; |
| 643 | |
| 644 | explicit |
| 645 | future(const __state_type& __state) : _Base_type(__state) { } |
| 646 | |
| 647 | public: |
| 648 | constexpr future() : _Base_type() { } |
| 649 | |
| 650 | /// Move constructor |
| 651 | future(future&& __uf) : _Base_type(std::move(__uf)) { } |
| 652 | |
| 653 | // Disable copying |
| 654 | future(const future&) = delete; |
| 655 | future& operator=(const future&) = delete; |
| 656 | |
| 657 | future& operator=(future&& __fut) |
| 658 | { |
| 659 | future(std::move(__fut))._M_swap(*this); |
| 660 | return *this; |
| 661 | } |
| 662 | |
| 663 | /// Retrieving the value |
| 664 | _Res& |
| 665 | get() |
| 666 | { |
| 667 | typename _Base_type::_Reset __reset(*this); |
| 668 | return this->_M_get_result()._M_get(); |
| 669 | } |
| 670 | }; |
| 671 | |
| 672 | /// Explicit specialization for future<void> |
| 673 | template<> |
| 674 | class future<void> : public __basic_future<void> |
| 675 | { |
| 676 | friend class promise<void>; |
| 677 | template<typename> friend class packaged_task; |
| 678 | template<typename _Fn, typename... _Args> |
| 679 | friend future<typename result_of<_Fn(_Args...)>::type> |
| 680 | async(launch, _Fn&&, _Args&&...); |
| 681 | |
| 682 | typedef __basic_future<void> _Base_type; |
| 683 | typedef typename _Base_type::__state_type __state_type; |
| 684 | |
| 685 | explicit |
| 686 | future(const __state_type& __state) : _Base_type(__state) { } |
| 687 | |
| 688 | public: |
| 689 | constexpr future() : _Base_type() { } |
| 690 | |
| 691 | /// Move constructor |
| 692 | future(future&& __uf) : _Base_type(std::move(__uf)) { } |
| 693 | |
| 694 | // Disable copying |
| 695 | future(const future&) = delete; |
| 696 | future& operator=(const future&) = delete; |
| 697 | |
| 698 | future& operator=(future&& __fut) |
| 699 | { |
| 700 | future(std::move(__fut))._M_swap(*this); |
| 701 | return *this; |
| 702 | } |
| 703 | |
| 704 | /// Retrieving the value |
| 705 | void |
| 706 | get() |
| 707 | { |
| 708 | typename _Base_type::_Reset __reset(*this); |
| 709 | this->_M_get_result(); |
| 710 | } |
| 711 | }; |
| 712 | |
| 713 | |
| 714 | /// Primary template for shared_future. |
| 715 | template<typename _Res> |
| 716 | class shared_future : public __basic_future<_Res> |
| 717 | { |
| 718 | typedef __basic_future<_Res> _Base_type; |
| 719 | |
| 720 | public: |
| 721 | constexpr shared_future() : _Base_type() { } |
| 722 | |
| 723 | /// Copy constructor |
| 724 | shared_future(const shared_future& __sf) : _Base_type(__sf) { } |
| 725 | |
| 726 | /// Construct from a future rvalue |
| 727 | shared_future(future<_Res>&& __uf) |
| 728 | : _Base_type(std::move(__uf)) |
| 729 | { } |
| 730 | |
| 731 | /// Construct from a shared_future rvalue |
| 732 | shared_future(shared_future&& __sf) |
| 733 | : _Base_type(std::move(__sf)) |
| 734 | { } |
| 735 | |
| 736 | shared_future& operator=(const shared_future& __sf) |
| 737 | { |
| 738 | shared_future(__sf)._M_swap(*this); |
| 739 | return *this; |
| 740 | } |
| 741 | |
| 742 | shared_future& operator=(shared_future&& __sf) |
| 743 | { |
| 744 | shared_future(std::move(__sf))._M_swap(*this); |
| 745 | return *this; |
| 746 | } |
| 747 | |
| 748 | /// Retrieving the value |
| 749 | const _Res& |
| 750 | get() |
| 751 | { |
| 752 | typename _Base_type::__result_type __r = this->_M_get_result(); |
| 753 | _Res& __rs(__r._M_value()); |
| 754 | return __rs; |
| 755 | } |
| 756 | }; |
| 757 | |
| 758 | /// Partial specialization for shared_future<R&> |
| 759 | template<typename _Res> |
| 760 | class shared_future<_Res&> : public __basic_future<_Res&> |
| 761 | { |
| 762 | typedef __basic_future<_Res&> _Base_type; |
| 763 | |
| 764 | public: |
| 765 | constexpr shared_future() : _Base_type() { } |
| 766 | |
| 767 | /// Copy constructor |
| 768 | shared_future(const shared_future& __sf) : _Base_type(__sf) { } |
| 769 | |
| 770 | /// Construct from a future rvalue |
| 771 | shared_future(future<_Res&>&& __uf) |
| 772 | : _Base_type(std::move(__uf)) |
| 773 | { } |
| 774 | |
| 775 | /// Construct from a shared_future rvalue |
| 776 | shared_future(shared_future&& __sf) |
| 777 | : _Base_type(std::move(__sf)) |
| 778 | { } |
| 779 | |
| 780 | shared_future& operator=(const shared_future& __sf) |
| 781 | { |
| 782 | shared_future(__sf)._M_swap(*this); |
| 783 | return *this; |
| 784 | } |
| 785 | |
| 786 | shared_future& operator=(shared_future&& __sf) |
| 787 | { |
| 788 | shared_future(std::move(__sf))._M_swap(*this); |
| 789 | return *this; |
| 790 | } |
| 791 | |
| 792 | /// Retrieving the value |
| 793 | _Res& |
| 794 | get() { return this->_M_get_result()._M_get(); } |
| 795 | }; |
| 796 | |
| 797 | /// Explicit specialization for shared_future<void> |
| 798 | template<> |
| 799 | class shared_future<void> : public __basic_future<void> |
| 800 | { |
| 801 | typedef __basic_future<void> _Base_type; |
| 802 | |
| 803 | public: |
| 804 | constexpr shared_future() : _Base_type() { } |
| 805 | |
| 806 | /// Copy constructor |
| 807 | shared_future(const shared_future& __sf) : _Base_type(__sf) { } |
| 808 | |
| 809 | /// Construct from a future rvalue |
| 810 | shared_future(future<void>&& __uf) |
| 811 | : _Base_type(std::move(__uf)) |
| 812 | { } |
| 813 | |
| 814 | /// Construct from a shared_future rvalue |
| 815 | shared_future(shared_future&& __sf) |
| 816 | : _Base_type(std::move(__sf)) |
| 817 | { } |
| 818 | |
| 819 | shared_future& operator=(const shared_future& __sf) |
| 820 | { |
| 821 | shared_future(__sf)._M_swap(*this); |
| 822 | return *this; |
| 823 | } |
| 824 | |
| 825 | shared_future& operator=(shared_future&& __sf) |
| 826 | { |
| 827 | shared_future(std::move(__sf))._M_swap(*this); |
| 828 | return *this; |
| 829 | } |
| 830 | |
| 831 | // Retrieving the value |
| 832 | void |
| 833 | get() { this->_M_get_result(); } |
| 834 | }; |
| 835 | |
| 836 | // Now we can define the protected __basic_future constructors. |
| 837 | template<typename _Res> |
| 838 | inline __basic_future<_Res>:: |
| 839 | __basic_future(const shared_future<_Res>& __sf) |
| 840 | : _M_state(__sf._M_state) |
| 841 | { } |
| 842 | |
| 843 | template<typename _Res> |
| 844 | inline __basic_future<_Res>:: |
| 845 | __basic_future(shared_future<_Res>&& __sf) |
| 846 | : _M_state(std::move(__sf._M_state)) |
| 847 | { } |
| 848 | |
| 849 | template<typename _Res> |
| 850 | inline __basic_future<_Res>:: |
| 851 | __basic_future(future<_Res>&& __uf) |
| 852 | : _M_state(std::move(__uf._M_state)) |
| 853 | { } |
| 854 | |
| 855 | |
| 856 | /// Primary template for promise |
| 857 | template<typename _Res> |
| 858 | class promise |
| 859 | { |
| 860 | typedef __future_base::_State_base _State; |
| 861 | typedef __future_base::_Result<_Res> _Res_type; |
| 862 | typedef typename __future_base::_Ptr<_Res_type>::type _Ptr_type; |
| 863 | template<typename, typename> friend class _State::_Setter; |
| 864 | |
| 865 | shared_ptr<_State> _M_future; |
| 866 | _Ptr_type _M_storage; |
| 867 | |
| 868 | public: |
| 869 | promise() |
| 870 | : _M_future(std::make_shared<_State>()), |
| 871 | _M_storage(new _Res_type()) |
| 872 | { } |
| 873 | |
| 874 | promise(promise&& __rhs) |
| 875 | : _M_future(std::move(__rhs._M_future)), |
| 876 | _M_storage(std::move(__rhs._M_storage)) |
| 877 | { } |
| 878 | |
| 879 | template<typename _Allocator> |
| 880 | promise(allocator_arg_t, const _Allocator& __a) |
| 881 | : _M_future(std::allocate_shared<_State>(__a)), |
| 882 | _M_storage(__future_base::_S_allocate_result<_Res>(__a)) |
| 883 | { } |
| 884 | |
| 885 | promise(const promise&) = delete; |
| 886 | |
| 887 | ~promise() |
| 888 | { |
| 889 | if (static_cast<bool>(_M_future) && !_M_future.unique()) |
| 890 | _M_future->_M_break_promise(std::move(_M_storage)); |
| 891 | } |
| 892 | |
| 893 | // Assignment |
| 894 | promise& |
| 895 | operator=(promise&& __rhs) |
| 896 | { |
| 897 | promise(std::move(__rhs)).swap(*this); |
| 898 | return *this; |
| 899 | } |
| 900 | |
| 901 | promise& operator=(const promise&) = delete; |
| 902 | |
| 903 | void |
| 904 | swap(promise& __rhs) |
| 905 | { |
| 906 | _M_future.swap(__rhs._M_future); |
| 907 | _M_storage.swap(__rhs._M_storage); |
| 908 | } |
| 909 | |
| 910 | // Retrieving the result |
| 911 | future<_Res> |
| 912 | get_future() |
| 913 | { return future<_Res>(_M_future); } |
| 914 | |
| 915 | // Setting the result |
| 916 | void |
| 917 | set_value(const _Res& __r) |
| 918 | { |
| 919 | auto __setter = _State::__setter(this, __r); |
| 920 | _M_future->_M_set_result(std::move(__setter)); |
| 921 | } |
| 922 | |
| 923 | void |
| 924 | set_value(_Res&& __r) |
| 925 | { |
| 926 | auto __setter = _State::__setter(this, std::move(__r)); |
| 927 | _M_future->_M_set_result(std::move(__setter)); |
| 928 | } |
| 929 | |
| 930 | void |
| 931 | set_exception(exception_ptr __p) |
| 932 | { |
| 933 | auto __setter = _State::__setter(__p, this); |
| 934 | _M_future->_M_set_result(std::move(__setter)); |
| 935 | } |
| 936 | }; |
| 937 | |
| 938 | template<typename _Res> |
| 939 | inline void |
| 940 | swap(promise<_Res>& __x, promise<_Res>& __y) |
| 941 | { __x.swap(__y); } |
| 942 | |
| 943 | template<typename _Res, typename _Alloc> |
| 944 | struct uses_allocator<promise<_Res>, _Alloc> |
| 945 | : public true_type { }; |
| 946 | |
| 947 | |
| 948 | /// Partial specialization for promise<R&> |
| 949 | template<typename _Res> |
| 950 | class promise<_Res&> |
| 951 | { |
| 952 | typedef __future_base::_State_base _State; |
| 953 | typedef __future_base::_Result<_Res&> _Res_type; |
| 954 | typedef typename __future_base::_Ptr<_Res_type>::type _Ptr_type; |
| 955 | template<typename, typename> friend class _State::_Setter; |
| 956 | |
| 957 | shared_ptr<_State> _M_future; |
| 958 | _Ptr_type _M_storage; |
| 959 | |
| 960 | public: |
| 961 | promise() |
| 962 | : _M_future(std::make_shared<_State>()), |
| 963 | _M_storage(new _Res_type()) |
| 964 | { } |
| 965 | |
| 966 | promise(promise&& __rhs) |
| 967 | : _M_future(std::move(__rhs._M_future)), |
| 968 | _M_storage(std::move(__rhs._M_storage)) |
| 969 | { } |
| 970 | |
| 971 | template<typename _Allocator> |
| 972 | promise(allocator_arg_t, const _Allocator& __a) |
| 973 | : _M_future(std::allocate_shared<_State>(__a)), |
| 974 | _M_storage(__future_base::_S_allocate_result<_Res&>(__a)) |
| 975 | { } |
| 976 | |
| 977 | promise(const promise&) = delete; |
| 978 | |
| 979 | ~promise() |
| 980 | { |
| 981 | if (static_cast<bool>(_M_future) && !_M_future.unique()) |
| 982 | _M_future->_M_break_promise(std::move(_M_storage)); |
| 983 | } |
| 984 | |
| 985 | // Assignment |
| 986 | promise& |
| 987 | operator=(promise&& __rhs) |
| 988 | { |
| 989 | promise(std::move(__rhs)).swap(*this); |
| 990 | return *this; |
| 991 | } |
| 992 | |
| 993 | promise& operator=(const promise&) = delete; |
| 994 | |
| 995 | void |
| 996 | swap(promise& __rhs) |
| 997 | { |
| 998 | _M_future.swap(__rhs._M_future); |
| 999 | _M_storage.swap(__rhs._M_storage); |
| 1000 | } |
| 1001 | |
| 1002 | // Retrieving the result |
| 1003 | future<_Res&> |
| 1004 | get_future() |
| 1005 | { return future<_Res&>(_M_future); } |
| 1006 | |
| 1007 | // Setting the result |
| 1008 | void |
| 1009 | set_value(_Res& __r) |
| 1010 | { |
| 1011 | auto __setter = _State::__setter(this, __r); |
| 1012 | _M_future->_M_set_result(std::move(__setter)); |
| 1013 | } |
| 1014 | |
| 1015 | void |
| 1016 | set_exception(exception_ptr __p) |
| 1017 | { |
| 1018 | auto __setter = _State::__setter(__p, this); |
| 1019 | _M_future->_M_set_result(std::move(__setter)); |
| 1020 | } |
| 1021 | }; |
| 1022 | |
| 1023 | /// Explicit specialization for promise<void> |
| 1024 | template<> |
| 1025 | class promise<void> |
| 1026 | { |
| 1027 | typedef __future_base::_State_base _State; |
| 1028 | typedef __future_base::_Result<void> _Res_type; |
| 1029 | typedef typename __future_base::_Ptr<_Res_type>::type _Ptr_type; |
| 1030 | template<typename, typename> friend class _State::_Setter; |
| 1031 | |
| 1032 | shared_ptr<_State> _M_future; |
| 1033 | _Ptr_type _M_storage; |
| 1034 | |
| 1035 | public: |
| 1036 | promise() |
| 1037 | : _M_future(std::make_shared<_State>()), |
| 1038 | _M_storage(new _Res_type()) |
| 1039 | { } |
| 1040 | |
| 1041 | promise(promise&& __rhs) |
| 1042 | : _M_future(std::move(__rhs._M_future)), |
| 1043 | _M_storage(std::move(__rhs._M_storage)) |
| 1044 | { } |
| 1045 | |
| 1046 | template<typename _Allocator> |
| 1047 | promise(allocator_arg_t, const _Allocator& __a) |
| 1048 | : _M_future(std::allocate_shared<_State>(__a)), |
| 1049 | _M_storage(__future_base::_S_allocate_result<void>(__a)) |
| 1050 | { } |
| 1051 | |
| 1052 | promise(const promise&) = delete; |
| 1053 | |
| 1054 | ~promise() |
| 1055 | { |
| 1056 | if (static_cast<bool>(_M_future) && !_M_future.unique()) |
| 1057 | _M_future->_M_break_promise(std::move(_M_storage)); |
| 1058 | } |
| 1059 | |
| 1060 | // Assignment |
| 1061 | promise& |
| 1062 | operator=(promise&& __rhs) |
| 1063 | { |
| 1064 | promise(std::move(__rhs)).swap(*this); |
| 1065 | return *this; |
| 1066 | } |
| 1067 | |
| 1068 | promise& operator=(const promise&) = delete; |
| 1069 | |
| 1070 | void |
| 1071 | swap(promise& __rhs) |
| 1072 | { |
| 1073 | _M_future.swap(__rhs._M_future); |
| 1074 | _M_storage.swap(__rhs._M_storage); |
| 1075 | } |
| 1076 | |
| 1077 | // Retrieving the result |
| 1078 | future<void> |
| 1079 | get_future() |
| 1080 | { return future<void>(_M_future); } |
| 1081 | |
| 1082 | // Setting the result |
| 1083 | void set_value(); |
| 1084 | |
| 1085 | void |
| 1086 | set_exception(exception_ptr __p) |
| 1087 | { |
| 1088 | auto __setter = _State::__setter(__p, this); |
| 1089 | _M_future->_M_set_result(std::move(__setter)); |
| 1090 | } |
| 1091 | }; |
| 1092 | |
| 1093 | // set void |
| 1094 | template<> |
| 1095 | struct __future_base::_State_base::_Setter<void, void> |
| 1096 | { |
| 1097 | promise<void>::_Ptr_type operator()() |
| 1098 | { |
| 1099 | _State_base::_S_check(_M_promise->_M_future); |
| 1100 | return std::move(_M_promise->_M_storage); |
| 1101 | } |
| 1102 | |
| 1103 | promise<void>* _M_promise; |
| 1104 | }; |
| 1105 | |
| 1106 | inline __future_base::_State_base::_Setter<void, void> |
| 1107 | __future_base::_State_base::__setter(promise<void>* __prom) |
| 1108 | { |
| 1109 | return _Setter<void, void>{ __prom }; |
| 1110 | } |
| 1111 | |
| 1112 | inline void |
| 1113 | promise<void>::set_value() |
| 1114 | { |
| 1115 | auto __setter = _State::__setter(this); |
| 1116 | _M_future->_M_set_result(std::move(__setter)); |
| 1117 | } |
| 1118 | |
| 1119 | |
| 1120 | template<typename _StateT, typename _Res> |
| 1121 | struct __future_base::_Task_setter |
| 1122 | { |
| 1123 | typename _StateT::_Ptr_type operator()() |
| 1124 | { |
| 1125 | __try |
| 1126 | { |
| 1127 | _M_state->_M_result->_M_set(_M_fn()); |
| 1128 | } |
| 1129 | __catch(...) |
| 1130 | { |
| 1131 | _M_state->_M_result->_M_error = current_exception(); |
| 1132 | } |
| 1133 | return std::move(_M_state->_M_result); |
| 1134 | } |
| 1135 | _StateT* _M_state; |
| 1136 | std::function<_Res()> _M_fn; |
| 1137 | }; |
| 1138 | |
| 1139 | template<typename _StateT> |
| 1140 | struct __future_base::_Task_setter<_StateT, void> |
| 1141 | { |
| 1142 | typename _StateT::_Ptr_type operator()() |
| 1143 | { |
| 1144 | __try |
| 1145 | { |
| 1146 | _M_fn(); |
| 1147 | } |
| 1148 | __catch(...) |
| 1149 | { |
| 1150 | _M_state->_M_result->_M_error = current_exception(); |
| 1151 | } |
| 1152 | return std::move(_M_state->_M_result); |
| 1153 | } |
| 1154 | _StateT* _M_state; |
| 1155 | std::function<void()> _M_fn; |
| 1156 | }; |
| 1157 | |
| 1158 | template<typename _Res, typename... _Args> |
| 1159 | struct __future_base::_Task_state<_Res(_Args...)> |
| 1160 | : __future_base::_State_base |
| 1161 | { |
| 1162 | typedef _Res _Res_type; |
| 1163 | |
| 1164 | _Task_state(std::function<_Res(_Args...)> __task) |
| 1165 | : _M_result(new _Result<_Res>()), _M_task(std::move(__task)) |
| 1166 | { } |
| 1167 | |
| 1168 | template<typename _Func, typename _Alloc> |
| 1169 | _Task_state(_Func&& __task, const _Alloc& __a) |
| 1170 | : _M_result(_S_allocate_result<_Res>(__a)), |
| 1171 | _M_task(allocator_arg, __a, std::move(__task)) |
| 1172 | { } |
| 1173 | |
| 1174 | void |
| 1175 | _M_run(_Args... __args) |
| 1176 | { |
| 1177 | // bound arguments decay so wrap lvalue references |
| 1178 | auto __bound = std::bind<_Res>(std::ref(_M_task), |
| 1179 | _S_maybe_wrap_ref(std::forward<_Args>(__args))...); |
| 1180 | _Task_setter<_Task_state> __setter{ this, std::move(__bound) }; |
| 1181 | _M_set_result(std::move(__setter)); |
| 1182 | } |
| 1183 | |
| 1184 | template<typename, typename> friend class _Task_setter; |
| 1185 | typedef typename __future_base::_Ptr<_Result<_Res>>::type _Ptr_type; |
| 1186 | _Ptr_type _M_result; |
| 1187 | std::function<_Res(_Args...)> _M_task; |
| 1188 | |
| 1189 | template<typename _Tp> |
| 1190 | static reference_wrapper<_Tp> |
| 1191 | _S_maybe_wrap_ref(_Tp& __t) |
| 1192 | { return std::ref(__t); } |
| 1193 | |
| 1194 | template<typename _Tp> |
| 1195 | static typename enable_if<!is_lvalue_reference<_Tp>::value, |
| 1196 | _Tp>::type&& |
| 1197 | _S_maybe_wrap_ref(_Tp&& __t) |
| 1198 | { return std::forward<_Tp>(__t); } |
| 1199 | }; |
| 1200 | |
| 1201 | /// packaged_task |
| 1202 | template<typename _Res, typename... _ArgTypes> |
| 1203 | class packaged_task<_Res(_ArgTypes...)> |
| 1204 | { |
| 1205 | typedef __future_base::_Task_state<_Res(_ArgTypes...)> _State_type; |
| 1206 | shared_ptr<_State_type> _M_state; |
| 1207 | |
| 1208 | public: |
| 1209 | typedef _Res result_type; |
| 1210 | |
| 1211 | // Construction and destruction |
| 1212 | packaged_task() { } |
| 1213 | |
| 1214 | template<typename _Fn> |
| 1215 | explicit |
| 1216 | packaged_task(const _Fn& __fn) |
| 1217 | : _M_state(std::make_shared<_State_type>(__fn)) |
| 1218 | { } |
| 1219 | |
| 1220 | template<typename _Fn> |
| 1221 | explicit |
| 1222 | packaged_task(_Fn&& __fn) |
| 1223 | : _M_state(std::make_shared<_State_type>(std::move(__fn))) |
| 1224 | { } |
| 1225 | |
| 1226 | explicit |
| 1227 | packaged_task(_Res(*__fn)(_ArgTypes...)) |
| 1228 | : _M_state(std::make_shared<_State_type>(__fn)) |
| 1229 | { } |
| 1230 | |
| 1231 | template<typename _Fn, typename _Allocator> |
| 1232 | explicit |
| 1233 | packaged_task(allocator_arg_t __tag, const _Allocator& __a, _Fn __fn) |
| 1234 | : _M_state(std::allocate_shared<_State_type>(__a, std::move(__fn))) |
| 1235 | { } |
| 1236 | |
| 1237 | ~packaged_task() |
| 1238 | { |
| 1239 | if (static_cast<bool>(_M_state) && !_M_state.unique()) |
| 1240 | _M_state->_M_break_promise(std::move(_M_state->_M_result)); |
| 1241 | } |
| 1242 | |
| 1243 | // No copy |
| 1244 | packaged_task(packaged_task&) = delete; |
| 1245 | packaged_task& operator=(packaged_task&) = delete; |
| 1246 | |
| 1247 | // Move support |
| 1248 | packaged_task(packaged_task&& __other) |
| 1249 | { this->swap(__other); } |
| 1250 | |
| 1251 | packaged_task& operator=(packaged_task&& __other) |
| 1252 | { |
| 1253 | packaged_task(std::move(__other)).swap(*this); |
| 1254 | return *this; |
| 1255 | } |
| 1256 | |
| 1257 | void |
| 1258 | swap(packaged_task& __other) |
| 1259 | { _M_state.swap(__other._M_state); } |
| 1260 | |
| 1261 | bool |
| 1262 | valid() const |
| 1263 | { return static_cast<bool>(_M_state); } |
| 1264 | |
| 1265 | // Result retrieval |
| 1266 | future<_Res> |
| 1267 | get_future() |
| 1268 | { return future<_Res>(_M_state); } |
| 1269 | |
| 1270 | // Execution |
| 1271 | void |
| 1272 | operator()(_ArgTypes... __args) |
| 1273 | { |
| 1274 | __future_base::_State_base::_S_check(_M_state); |
| 1275 | _M_state->_M_run(std::forward<_ArgTypes>(__args)...); |
| 1276 | } |
| 1277 | |
| 1278 | void |
| 1279 | reset() |
| 1280 | { |
| 1281 | __future_base::_State_base::_S_check(_M_state); |
| 1282 | packaged_task(std::move(_M_state->_M_task)).swap(*this); |
| 1283 | } |
| 1284 | }; |
| 1285 | |
| 1286 | /// swap |
| 1287 | template<typename _Res, typename... _ArgTypes> |
| 1288 | inline void |
| 1289 | swap(packaged_task<_Res(_ArgTypes...)>& __x, |
| 1290 | packaged_task<_Res(_ArgTypes...)>& __y) |
| 1291 | { __x.swap(__y); } |
| 1292 | |
| 1293 | template<typename _Res, typename _Alloc> |
| 1294 | struct uses_allocator<packaged_task<_Res>, _Alloc> |
| 1295 | : public true_type { }; |
| 1296 | |
| 1297 | |
| 1298 | template<typename _Res> |
| 1299 | class __future_base::_Deferred_state : public __future_base::_State_base |
| 1300 | { |
| 1301 | public: |
| 1302 | typedef _Res _Res_type; |
| 1303 | |
| 1304 | explicit |
| 1305 | _Deferred_state(std::function<_Res()>&& __fn) |
| 1306 | : _M_result(new _Result<_Res>()), _M_fn(std::move(__fn)) |
| 1307 | { } |
| 1308 | |
| 1309 | private: |
| 1310 | template<typename, typename> friend class _Task_setter; |
| 1311 | typedef typename __future_base::_Ptr<_Result<_Res>>::type _Ptr_type; |
| 1312 | _Ptr_type _M_result; |
| 1313 | std::function<_Res()> _M_fn; |
| 1314 | |
| 1315 | virtual void |
| 1316 | _M_run_deferred() |
| 1317 | { |
| 1318 | _Task_setter<_Deferred_state> __setter{ this, _M_fn }; |
| 1319 | // safe to call multiple times so ignore failure |
| 1320 | _M_set_result(std::move(__setter), true); |
| 1321 | } |
| 1322 | }; |
| 1323 | |
| 1324 | template<typename _Res> |
| 1325 | class __future_base::_Async_state : public __future_base::_State_base |
| 1326 | { |
| 1327 | public: |
| 1328 | typedef _Res _Res_type; |
| 1329 | |
| 1330 | explicit |
| 1331 | _Async_state(std::function<_Res()>&& __fn) |
| 1332 | : _M_result(new _Result<_Res>()), _M_fn(std::move(__fn)), |
| 1333 | _M_thread(mem_fn(&_Async_state::_M_do_run), this) |
| 1334 | { } |
| 1335 | |
| 1336 | ~_Async_state() { _M_thread.join(); } |
| 1337 | |
| 1338 | private: |
| 1339 | void _M_do_run() |
| 1340 | { |
| 1341 | _Task_setter<_Async_state> __setter{ this, std::move(_M_fn) }; |
| 1342 | _M_set_result(std::move(__setter)); |
| 1343 | } |
| 1344 | |
| 1345 | template<typename, typename> friend class _Task_setter; |
| 1346 | typedef typename __future_base::_Ptr<_Result<_Res>>::type _Ptr_type; |
| 1347 | _Ptr_type _M_result; |
| 1348 | std::function<_Res()> _M_fn; |
| 1349 | thread _M_thread; |
| 1350 | }; |
| 1351 | |
| 1352 | /// async |
| 1353 | template<typename _Fn, typename... _Args> |
| 1354 | future<typename result_of<_Fn(_Args...)>::type> |
| 1355 | async(launch __policy, _Fn&& __fn, _Args&&... __args) |
| 1356 | { |
| 1357 | typedef typename result_of<_Fn(_Args...)>::type result_type; |
| 1358 | std::shared_ptr<__future_base::_State_base> __state; |
| 1359 | if (__policy == launch::async) |
| 1360 | { |
| 1361 | typedef typename __future_base::_Async_state<result_type> _State; |
| 1362 | __state = std::make_shared<_State>(std::bind<result_type>( |
| 1363 | std::forward<_Fn>(__fn), std::forward<_Args>(__args)...)); |
| 1364 | } |
| 1365 | else |
| 1366 | { |
| 1367 | typedef typename __future_base::_Deferred_state<result_type> _State; |
| 1368 | __state = std::make_shared<_State>(std::bind<result_type>( |
| 1369 | std::forward<_Fn>(__fn), std::forward<_Args>(__args)...)); |
| 1370 | } |
| 1371 | return future<result_type>(__state); |
| 1372 | } |
| 1373 | |
| 1374 | /// async, potential overload |
| 1375 | template<typename _Fn, typename... _Args> |
| 1376 | inline typename |
| 1377 | __async_sfinae_helper<typename decay<_Fn>::type, _Fn, _Args...>::type |
| 1378 | async(_Fn&& __fn, _Args&&... __args) |
| 1379 | { |
| 1380 | return async(launch::any, std::forward<_Fn>(__fn), |
| 1381 | std::forward<_Args>(__args)...); |
| 1382 | } |
| 1383 | |
| 1384 | #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1 |
| 1385 | // && _GLIBCXX_ATOMIC_BUILTINS_4 |
| 1386 | |
| 1387 | // @} group futures |
| 1388 | _GLIBCXX_END_NAMESPACE_VERSION |
| 1389 | } // namespace |
| 1390 | |
| 1391 | #endif // __GXX_EXPERIMENTAL_CXX0X__ |
| 1392 | |
| 1393 | #endif // _GLIBCXX_FUTURE |