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| 1 | // Copyright (c) 2007-2015 Hartmut Kaiser | |
| 2 | // Copyright (c) 2014-2015 Agustin Berge | |
| 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 | #if !defined(HPX_LCOS_LOCAL_CONTINUATION_APR_17_2012_0150PM) | |
| 8 | #define HPX_LCOS_LOCAL_CONTINUATION_APR_17_2012_0150PM | |
| 9 | ||
| 10 | #include <hpx/config.hpp> | |
| 11 | #include <hpx/error_code.hpp> | |
| 12 | #include <hpx/lcos/detail/future_data.hpp> | |
| 13 | #include <hpx/lcos/future.hpp> | |
| 14 | #include <hpx/runtime/launch_policy.hpp> | |
| 15 | #include <hpx/throw_exception.hpp> | |
| 16 | #include <hpx/traits/future_access.hpp> | |
| 17 | #include <hpx/traits/future_traits.hpp> | |
| 18 | #include <hpx/traits/is_executor.hpp> | |
| 19 | #include <hpx/util/decay.hpp> | |
| 20 | #include <hpx/util/thread_description.hpp> | |
| 21 | ||
| 22 | #include <boost/intrusive_ptr.hpp> | |
| 23 | ||
| 24 | #include <functional> | |
| 25 | #include <mutex> | |
| 26 | #include <utility> | |
| 27 | #include <type_traits> | |
| 28 | ||
| 29 | /////////////////////////////////////////////////////////////////////////////// | |
| 30 | namespace hpx { namespace lcos { namespace detail | |
| 31 | { | |
| 32 | template <typename Future> | |
| 33 | struct transfer_result | |
| 34 | { | |
| 35 | template <typename Source, typename Destination> | |
| 36 | void apply(Source&& src, Destination& dest, std::false_type) const | |
| 37 | { | |
| 38 | try { | |
| 39 | dest.set_value(src.get()); | |
| 40 | } | |
| 41 | catch (...) { | |
| 42 | dest.set_exception(boost::current_exception()); | |
| 43 | } | |
| 44 | } | |
| 45 | ||
| 46 | template <typename Source, typename Destination> | |
| 47 | void apply(Source&& src, Destination& dest, std::true_type) const | |
| 48 | { | |
| 49 | try { | |
| 50 | src.get(); | |
| 51 | dest.set_value(util::unused); | |
| 52 | } | |
| 53 | catch (...) { | |
| 54 | dest.set_exception(boost::current_exception()); | |
| 55 | } | |
| 56 | } | |
| 57 | ||
| 58 | template <typename SourceState, typename DestinationState> | |
| 59 | void operator()(SourceState& src, DestinationState const& dest) const | |
| 60 | { | |
| 61 | typedef std::is_void< | |
| 62 | typename traits::future_traits<Future>::type | |
| 63 | > is_void; | |
| 64 | ||
| 65 | apply(traits::future_access<Future>::create(src), *dest, is_void()); | |
| 66 | } | |
| 67 | }; | |
| 68 | ||
| 69 | template <typename Func, typename Future, typename Continuation> | |
| 70 | void invoke_continuation(Func& func, Future& future, Continuation& cont, | |
| 71 | std::false_type) | |
| 72 | { | |
| 73 | try { | |
| 74 | cont.set_value(func(std::move(future))); | |
| 75 | } | |
| 76 | catch (...) { | |
| 77 | cont.set_exception(boost::current_exception()); | |
| 78 | } | |
| 79 | } | |
| 80 | ||
| 81 | template <typename Func, typename Future, typename Continuation> | |
| 82 | void invoke_continuation(Func& func, Future& future, Continuation& cont, | |
| 83 | std::true_type) | |
| 84 | { | |
| 85 | try { | |
| 86 | func(std::move(future)); | |
| 87 | cont.set_value(util::unused); | |
| 88 | } | |
| 89 | catch (...) { | |
| 90 | cont.set_exception(boost::current_exception()); | |
| 91 | } | |
| 92 | } | |
| 93 | ||
| 94 | template <typename Func, typename Future, typename Continuation> | |
| 95 | typename std::enable_if< | |
| 96 | !traits::detail::is_unique_future< | |
| 97 | typename util::result_of<Func(Future)>::type | |
| 98 | >::value | |
| 99 | >::type invoke_continuation(Func& func, Future& future, Continuation& cont) | |
| 100 | { | |
| 101 | typedef std::is_void< | |
| 102 | typename util::result_of<Func(Future)>::type | |
| 103 | > is_void; | |
| 104 | ||
| 105 | invoke_continuation(func, future, cont, is_void()); | |
| 106 | } | |
| 107 | ||
| 108 | template <typename Func, typename Future, typename Continuation> | |
| 109 | typename std::enable_if< | |
| 110 | traits::detail::is_unique_future< | |
| 111 | typename util::result_of<Func(Future)>::type | |
| 112 | >::value | |
| 113 | >::type invoke_continuation(Func& func, Future& future, Continuation& cont) | |
| 114 | { | |
| 115 | try { | |
| 116 | typedef | |
| 117 | typename util::result_of<Func(Future)>::type | |
| 118 | inner_future; | |
| 119 | typedef | |
| 120 | typename traits::detail::shared_state_ptr_for<inner_future>::type | |
| 121 | inner_shared_state_ptr; | |
| 122 | ||
| 123 | // take by value, as the future may go away immediately | |
| 124 | inner_shared_state_ptr inner_state = | |
| 125 | traits::detail::get_shared_state(func(std::move(future))); | |
| 126 | ||
| 127 | if (inner_state.get() == nullptr) | |
| 128 | { | |
| 129 | HPX_THROW_EXCEPTION(no_state, | |
| 130 | "invoke_continuation", | |
| 131 | "the inner future has no valid shared state"); | |
| 132 | } | |
| 133 | ||
| 134 | // Bind an on_completed handler to this future which will transfer | |
| 135 | // its result to the new future. | |
| 136 | boost::intrusive_ptr<Continuation> cont_(&cont); | |
| 137 | inner_state->execute_deferred(); | |
| 138 | inner_state->set_on_completed(util::bind( | |
| 139 | transfer_result<inner_future>(), inner_state, cont_)); | |
| 140 | } | |
| 141 | catch (...) { | |
| 142 | cont.set_exception(boost::current_exception()); | |
| 143 | } | |
| 144 | } | |
| 145 | ||
| 146 | /////////////////////////////////////////////////////////////////////////// | |
| 147 | template <typename ContResult> | |
| 148 | struct continuation_result | |
| 149 | { | |
| 150 | typedef ContResult type; | |
| 151 | }; | |
| 152 | ||
| 153 | template <typename ContResult> | |
| 154 | struct continuation_result<future<ContResult> > | |
| 155 | { | |
| 156 | typedef ContResult type; | |
| 157 | }; | |
| 158 | ||
| 159 | /////////////////////////////////////////////////////////////////////////// | |
| 160 | template <typename Future, typename F, typename ContResult> | |
| 161 | class continuation | |
| 162 | : public future_data<typename continuation_result<ContResult>::type> | |
| 163 | { | |
| 164 | private: | |
| 165 | typedef future_data<ContResult> base_type; | |
| 166 | ||
| 167 | typedef typename base_type::mutex_type mutex_type; | |
| 168 | typedef typename base_type::result_type result_type; | |
| 169 | ||
| 170 | protected: | |
| 171 | threads::thread_id_type get_id() const | |
| 172 | { | |
| 173 | std::lock_guard<mutex_type> l(this->mtx_); | |
| 174 | return id_; | |
| 175 | } | |
| 176 | void set_id(threads::thread_id_type const& id) | |
| 177 | { | |
| 178 | std::lock_guard<mutex_type> l(this->mtx_); | |
| 179 | id_ = id; | |
| 180 | } | |
| 181 | ||
| 182 | struct reset_id | |
| 183 | { | |
| 184 | reset_id(continuation& target) | |
| 185 | : target_(target) | |
| 186 | { | |
| 187 | if (threads::get_self_ptr() != nullptr) | |
| 188 | target.set_id(threads::get_self_id()); | |
| 189 | } | |
| 190 | ~reset_id() | |
| 191 | { | |
| 192 | target_.set_id(threads::invalid_thread_id); | |
| 193 | } | |
| 194 | continuation& target_; | |
| 195 | }; | |
| 196 | ||
| 197 | public: | |
| 198 | template <typename Func> | |
| 199 | continuation(Func && f) | |
| 200 | : started_(false), id_(threads::invalid_thread_id) | |
| 201 | , f_(std::forward<Func>(f)) | |
| 202 | {} | |
| 203 | ||
| 204 | void run_impl( | |
| 205 | typename traits::detail::shared_state_ptr_for< | |
| 206 | Future | |
| 207 | >::type const& f) | |
| 208 | { | |
| 209 | Future future = traits::future_access<Future>::create(f); | |
| 210 | invoke_continuation(f_, future, *this); | |
| 211 | } | |
| 212 | ||
| 213 | void run( | |
| 214 | typename traits::detail::shared_state_ptr_for< | |
| 215 | Future | |
| 216 | >::type const& f, error_code& ec) | |
| 217 | { | |
| 218 | { | |
| 219 | std::lock_guard<mutex_type> l(this->mtx_); | |
| 220 | if (started_) { | |
| 221 | HPX_THROWS_IF(ec, task_already_started, | |
| 222 | "continuation::run", | |
| 223 | "this task has already been started"); | |
| 224 | return; | |
| 225 | } | |
| 226 | started_ = true; | |
| 227 | } | |
| 228 | ||
| 229 | run_impl(f); | |
| 230 | ||
| 231 | if (&ec != &throws) | |
| 232 | ec = make_success_code(); | |
| 233 | } | |
| 234 | ||
| 235 | void run( | |
| 236 | typename traits::detail::shared_state_ptr_for< | |
| 237 | Future | |
| 238 | >::type const& f) | |
| 239 | { | |
| 240 | run(f, throws); | |
| 241 | } | |
| 242 | ||
| 243 | threads::thread_result_type | |
| 244 | async_impl( | |
| 245 | typename traits::detail::shared_state_ptr_for< | |
| 246 | Future | |
| 247 | >::type const& f) | |
| 248 | { | |
| 249 | reset_id r(*this); | |
| 250 | ||
| 251 | Future future = traits::future_access<Future>::create(f); | |
| 252 | invoke_continuation(f_, future, *this); | |
| 253 | return threads::thread_result_type(threads::terminated, nullptr); | |
| 254 | } | |
| 255 | ||
| 256 | void async( | |
| 257 | typename traits::detail::shared_state_ptr_for< | |
| 258 | Future | |
| 259 | >::type const& f, | |
| 260 | error_code& ec) | |
| 261 | { | |
| 262 | { | |
| 263 | std::lock_guard<mutex_type> l(this->mtx_); | |
| 264 | if (started_) { | |
| 265 | HPX_THROWS_IF(ec, task_already_started, | |
| 266 | "continuation::async", | |
| 267 | "this task has already been started"); | |
| 268 | return; | |
| 269 | } | |
| 270 | started_ = true; | |
| 271 | } | |
| 272 | ||
| 273 | boost::intrusive_ptr<continuation> this_(this); | |
| 274 | threads::thread_result_type (continuation::*async_impl_ptr)( | |
| 275 | typename traits::detail::shared_state_ptr_for<Future>::type const& | |
| 276 | ) = &continuation::async_impl; | |
| 277 | ||
| 278 | util::thread_description desc(f_, "continuation::async"); | |
| 279 | applier::register_thread_plain( | |
| 280 | util::bind(async_impl_ptr, std::move(this_), f), desc); | |
| 281 | ||
| 282 | if (&ec != &throws) | |
| 283 | ec = make_success_code(); | |
| 284 | } | |
| 285 | ||
| 286 | void async( | |
| 287 | typename traits::detail::shared_state_ptr_for< | |
| 288 | Future | |
| 289 | >::type const& f, | |
| 290 | threads::executor& sched, error_code& ec) | |
| 291 | { | |
| 292 | { | |
| 293 | std::lock_guard<mutex_type> l(this->mtx_); | |
| 294 | if (started_) { | |
| 295 | HPX_THROWS_IF(ec, task_already_started, | |
| 296 | "continuation::async", | |
| 297 | "this task has already been started"); | |
| 298 | return; | |
| 299 | } | |
| 300 | started_ = true; | |
| 301 | } | |
| 302 | ||
| 303 | boost::intrusive_ptr<continuation> this_(this); | |
| 304 | threads::thread_result_type (continuation::*async_impl_ptr)( | |
| 305 | typename traits::detail::shared_state_ptr_for<Future>::type const& | |
| 306 | ) = &continuation::async_impl; | |
| 307 | ||
| 308 | util::thread_description desc(f_, "continuation::async"); | |
| 309 | sched.add(util::bind(async_impl_ptr, std::move(this_), f), desc); | |
| 310 | ||
| 311 | if (&ec != &throws) | |
| 312 | ec = make_success_code(); | |
| 313 | } | |
| 314 | ||
| 315 | template <typename Executor> | |
| 316 | void async_exec( | |
| 317 | typename traits::detail::shared_state_ptr_for< | |
| 318 | Future | |
| 319 | >::type const& f, | |
| 320 | Executor& exec, error_code& ec) | |
| 321 | { | |
| 322 | { | |
| 323 | std::lock_guard<mutex_type> l(this->mtx_); | |
| 324 | if (started_) { | |
| 325 | HPX_THROWS_IF(ec, task_already_started, | |
| 326 | "continuation::async_exec", | |
| 327 | "this task has already been started"); | |
| 328 | return; | |
| 329 | } | |
| 330 | started_ = true; | |
| 331 | } | |
| 332 | ||
| 333 | boost::intrusive_ptr<continuation> this_(this); | |
| 334 | threads::thread_result_type (continuation::*async_impl_ptr)( | |
| 335 | typename traits::detail::shared_state_ptr_for<Future>::type const& | |
| 336 | ) = &continuation::async_impl; | |
| 337 | ||
| 338 | parallel::executor_traits<Executor>::apply_execute( | |
| 339 | exec, async_impl_ptr, std::move(this_), f); | |
| 340 | ||
| 341 | if (&ec != &throws) | |
| 342 | ec = make_success_code(); | |
| 343 | } | |
| 344 | ||
| 345 | void async( | |
| 346 | typename traits::detail::shared_state_ptr_for< | |
| 347 | Future | |
| 348 | >::type const& f) | |
| 349 | { | |
| 350 | async(f, throws); | |
| 351 | } | |
| 352 | ||
| 353 | void async( | |
| 354 | typename traits::detail::shared_state_ptr_for< | |
| 355 | Future | |
| 356 | >::type const& f, threads::executor& sched) | |
| 357 | { | |
| 358 | async(f, sched, throws); | |
| 359 | } | |
| 360 | ||
| 361 | template <typename Executor> | |
| 362 | void async_exec( | |
| 363 | typename traits::detail::shared_state_ptr_for< | |
| 364 | Future | |
| 365 | >::type const& f, | |
| 366 | Executor& exec) | |
| 367 | { | |
| 368 | async_exec(f, exec, throws); | |
| 369 | } | |
| 370 | ||
| 371 | // cancellation support | |
| 372 | bool cancelable() const | |
| 373 | { | |
| 374 | return true; | |
| 375 | } | |
| 376 | ||
| 377 | void cancel() | |
| 378 | { | |
| 379 | std::unique_lock<mutex_type> l(this->mtx_); | |
| 380 | try { | |
| 381 | if (!this->started_) | |
| 382 | HPX_THROW_THREAD_INTERRUPTED_EXCEPTION(); | |
| 383 | ||
| 384 | if (this->is_ready_locked()) | |
| 385 | return; // nothing we can do | |
| 386 | ||
| 387 | if (id_ != threads::invalid_thread_id) { | |
| 388 | // interrupt the executing thread | |
| 389 | threads::interrupt_thread(id_); | |
| 390 | ||
| 391 | this->started_ = true; | |
| 392 | ||
| 393 | l.unlock(); | |
| 394 | this->set_error(future_cancelled, | |
| 395 | "continuation<Future, ContResult>::cancel", | |
| 396 | "future has been canceled"); | |
| 397 | } | |
| 398 | else { | |
| 399 | HPX_THROW_EXCEPTION(future_can_not_be_cancelled, | |
| 400 | "continuation<Future, ContResult>::cancel", | |
| 401 | "future can't be canceled at this time"); | |
| 402 | } | |
| 403 | } | |
| 404 | catch (...) { | |
| 405 | this->started_ = true; | |
| 406 | this->set_exception(boost::current_exception()); | |
| 407 | throw; | |
| 408 | } | |
| 409 | } | |
| 410 | ||
| 411 | public: | |
| 412 | void attach(Future const& future, launch policy) | |
| 413 | { | |
| 414 | typedef | |
| 415 | typename traits::detail::shared_state_ptr_for<Future>::type | |
| 416 | shared_state_ptr; | |
| 417 | ||
| 418 | // bind an on_completed handler to this future which will invoke | |
| 419 | // the continuation | |
| 420 | boost::intrusive_ptr<continuation> this_(this); | |
| 421 | void (continuation::*cb)(shared_state_ptr const&); | |
| 422 | if (policy & launch::sync) | |
| 423 | cb = &continuation::run; | |
| 424 | else | |
| 425 | cb = &continuation::async; | |
| 426 | ||
| 427 | shared_state_ptr const& state = | |
| 428 | traits::detail::get_shared_state(future); | |
| 429 | state->execute_deferred(); | |
| 430 | state->set_on_completed(util::bind(cb, std::move(this_), state)); | |
| 431 | } | |
| 432 | ||
| 433 | void attach(Future const& future, threads::executor& sched) | |
| 434 | { | |
| 435 | typedef | |
| 436 | typename traits::detail::shared_state_ptr_for<Future>::type | |
| 437 | shared_state_ptr; | |
| 438 | ||
| 439 | // bind an on_completed handler to this future which will invoke | |
| 440 | // the continuation | |
| 441 | boost::intrusive_ptr<continuation> this_(this); | |
| 442 | void (continuation::*cb)( | |
| 443 | shared_state_ptr const&, threads::executor& | |
| 444 | ) = &continuation::async; | |
| 445 | ||
| 446 | shared_state_ptr const& state = | |
| 447 | traits::detail::get_shared_state(future); | |
| 448 | state->execute_deferred(); | |
| 449 | state->set_on_completed(util::bind(cb, std::move(this_), | |
| 450 | state, std::ref(sched))); | |
| 451 | } | |
| 452 | ||
| 453 | template <typename Executor> | |
| 454 | void attach_exec(Future const& future, Executor& exec) | |
| 455 | { | |
| 456 | typedef | |
| 457 | typename traits::detail::shared_state_ptr_for<Future>::type | |
| 458 | shared_state_ptr; | |
| 459 | ||
| 460 | // bind an on_completed handler to this future which will invoke | |
| 461 | // the continuation | |
| 462 | boost::intrusive_ptr<continuation> this_(this); | |
| 463 | void (continuation::*cb)(shared_state_ptr const&, Executor&) = | |
| 464 | &continuation::async_exec<Executor>; | |
| 465 | ||
| 466 | shared_state_ptr const& state = | |
| 467 | traits::detail::get_shared_state(future); | |
| 468 | state->execute_deferred(); | |
| 469 | state->set_on_completed(util::bind(cb, std::move(this_), | |
| 470 | state, std::ref(exec))); | |
| 471 | } | |
| 472 | ||
| 473 | protected: | |
| 474 | bool started_; | |
| 475 | threads::thread_id_type id_; | |
| 476 | typename util::decay<F>::type f_; | |
| 477 | }; | |
| 478 | ||
| 479 | /////////////////////////////////////////////////////////////////////////// | |
| 480 | template <typename ContResult, typename Future, typename F> | |
| 481 | inline typename traits::detail::shared_state_ptr< | |
| 482 | typename continuation_result<ContResult>::type | |
| 483 | >::type | |
| 484 | make_continuation(Future const& future, launch policy, F && f) | |
| 485 | { | |
| 486 | typedef detail::continuation<Future, F, ContResult> shared_state; | |
| 487 | typedef typename continuation_result<ContResult>::type result_type; | |
| 488 | ||
| 489 | // create a continuation | |
| 490 | typename traits::detail::shared_state_ptr<result_type>::type p( | |
| 491 | new shared_state(std::forward<F>(f))); | |
| 492 | static_cast<shared_state*>(p.get())->attach(future, policy); | |
| 493 | return p; | |
| 494 | } | |
| 495 | ||
| 496 | template <typename ContResult, typename Future, typename F> | |
| 497 | inline typename traits::detail::shared_state_ptr< | |
| 498 | typename continuation_result<ContResult>::type | |
| 499 | >::type | |
| 500 | make_continuation(Future const& future, threads::executor& sched, F && f) | |
| 501 | { | |
| 502 | typedef detail::continuation<Future, F, ContResult> shared_state; | |
| 503 | typedef typename continuation_result<ContResult>::type result_type; | |
| 504 | ||
| 505 | // create a continuation | |
| 506 | typename traits::detail::shared_state_ptr<result_type>::type p( | |
| 507 | new shared_state(std::forward<F>(f))); | |
| 508 | static_cast<shared_state*>(p.get())->attach(future, sched); | |
| 509 | return p; | |
| 510 | } | |
| 511 | ||
| 512 | template <typename ContResult, typename Future, typename Executor, | |
| 513 | typename F> | |
| 514 | inline typename traits::detail::shared_state_ptr< | |
| 515 | typename continuation_result<ContResult>::type | |
| 516 | >::type | |
| 517 | make_continuation_exec(Future const& future, Executor& exec, F && f) | |
| 518 | { | |
| 519 | typedef detail::continuation<Future, F, ContResult> shared_state; | |
| 520 | typedef typename continuation_result<ContResult>::type result_type; | |
| 521 | ||
| 522 | // create a continuation | |
| 523 | typename traits::detail::shared_state_ptr<result_type>::type p( | |
| 524 | new shared_state(std::forward<F>(f))); | |
| 525 | static_cast<shared_state*>(p.get())->attach_exec(future, exec); | |
| 526 | return p; | |
| 527 | } | |
| 528 | }}} | |
| 529 | ||
| 530 | /////////////////////////////////////////////////////////////////////////////// | |
| 531 | namespace hpx { namespace lcos { namespace detail | |
| 532 | { | |
| 533 | /////////////////////////////////////////////////////////////////////////// | |
| 534 | template <typename ContResult> | |
| 535 | class unwrap_continuation : public future_data<ContResult> | |
| 536 | { | |
| 537 | private: | |
| 538 | template <typename Inner> | |
| 539 | void on_inner_ready( | |
| 540 | typename traits::detail::shared_state_ptr_for< | |
| 541 | Inner | |
| 542 | >::type const& inner_state) | |
| 543 | { | |
| 544 | try { | |
| 545 | unwrap_continuation* this_ = this; | |
| 546 | transfer_result<Inner>()(inner_state, this_); | |
| 547 | } | |
| 548 | catch (...) { | |
| 549 | this->set_exception(boost::current_exception()); | |
| 550 | } | |
| 551 | } | |
| 552 | ||
| 553 | template <typename Outer> | |
| 554 | void on_outer_ready( | |
| 555 | typename traits::detail::shared_state_ptr_for< | |
| 556 | Outer | |
| 557 | >::type const& outer_state) | |
| 558 | { | |
| 559 | typedef typename traits::future_traits<Outer>::type inner_future; | |
| 560 | typedef | |
| 561 | typename traits::detail::shared_state_ptr_for<inner_future>::type | |
| 562 | inner_shared_state_ptr; | |
| 563 | ||
| 564 | // Bind an on_completed handler to this future which will transfer | |
| 565 | // its result to the new future. | |
| 566 | boost::intrusive_ptr<unwrap_continuation> this_(this); | |
| 567 | void (unwrap_continuation::*inner_ready)( | |
| 568 | inner_shared_state_ptr const&) = | |
| 569 | &unwrap_continuation::on_inner_ready<inner_future>; | |
| 570 | ||
| 571 | try { | |
| 572 | // if we get here, this future is ready | |
| 573 | Outer outer = traits::future_access<Outer>::create(outer_state); | |
| 574 | ||
| 575 | // take by value, as the future will go away immediately | |
| 576 | inner_shared_state_ptr inner_state = | |
| 577 | traits::detail::get_shared_state(outer.get()); | |
| 578 | ||
| 579 | if (inner_state.get() == nullptr) | |
| 580 | { | |
| 581 | HPX_THROW_EXCEPTION(no_state, | |
| 582 | "unwrap_continuation<ContResult>::on_outer_ready", | |
| 583 | "the inner future has no valid shared state"); | |
| 584 | } | |
| 585 | ||
| 586 | inner_state->execute_deferred(); | |
| 587 | inner_state->set_on_completed( | |
| 588 | util::bind(inner_ready, std::move(this_), inner_state)); | |
| 589 | } | |
| 590 | catch (...) { | |
| 591 | this->set_exception(boost::current_exception()); | |
| 592 | } | |
| 593 | } | |
| 594 | ||
| 595 | public: | |
| 596 | template <typename Future> | |
| 597 | void attach(Future& future) | |
| 598 | { | |
| 599 | typedef | |
| 600 | typename traits::detail::shared_state_ptr_for<Future>::type | |
| 601 | outer_shared_state_ptr; | |
| 602 | ||
| 603 | // Bind an on_completed handler to this future which will wait for | |
| 604 | // the inner future and will transfer its result to the new future. | |
| 605 | boost::intrusive_ptr<unwrap_continuation> this_(this); | |
| 606 | void (unwrap_continuation::*outer_ready)( | |
| 607 | outer_shared_state_ptr const&) = | |
| 608 | &unwrap_continuation::on_outer_ready<Future>; | |
| 609 | ||
| 610 | outer_shared_state_ptr const& outer_state = | |
| 611 | traits::detail::get_shared_state(future); | |
| 612 | outer_state->execute_deferred(); | |
| 613 | outer_state->set_on_completed( | |
| 614 | util::bind(outer_ready, std::move(this_), outer_state)); | |
| 615 | } | |
| 616 | }; | |
| 617 | ||
| 618 | template <typename Future> | |
| 619 | inline typename traits::detail::shared_state_ptr< | |
| 620 | typename future_unwrap_result<Future>::result_type>::type | |
| 621 | unwrap(Future&& future, error_code& ec) | |
| 622 | { | |
| 623 | typedef typename future_unwrap_result<Future>::result_type result_type; | |
| 624 | typedef detail::unwrap_continuation<result_type> shared_state; | |
| 625 | ||
| 626 | // create a continuation | |
| 627 | typename traits::detail::shared_state_ptr<result_type>::type p( | |
| 628 | new shared_state()); | |
| 629 | static_cast<shared_state*>(p.get())->attach(future); | |
| 630 | return p; | |
| 631 | } | |
| 632 | }}} | |
| 633 | ||
| 634 | /////////////////////////////////////////////////////////////////////////////// | |
| 635 | namespace hpx { namespace lcos { namespace detail | |
| 636 | { | |
| 637 | class void_continuation : public future_data<void> | |
| 638 | { | |
| 639 | private: | |
| 640 | template <typename Future> | |
| 641 | void on_ready( | |
| 642 | typename traits::detail::shared_state_ptr_for< | |
| 643 | Future | |
| 644 | >::type const& state) | |
| 645 | { | |
| 646 | try { | |
| 647 | (void)state->get_result(); | |
| 648 | this->set_value(util::unused); | |
| 649 | } | |
| 650 | catch (...) { | |
| 651 | this->set_exception(boost::current_exception()); | |
| 652 | } | |
| 653 | } | |
| 654 | ||
| 655 | public: | |
| 656 | template <typename Future> | |
| 657 | void attach(Future& future) | |
| 658 | { | |
| 659 | typedef | |
| 660 | typename traits::detail::shared_state_ptr_for<Future>::type | |
| 661 | shared_state_ptr; | |
| 662 | ||
| 663 | // Bind an on_completed handler to this future which will wait for | |
| 664 | // the inner future and will transfer its result to the new future. | |
| 665 | boost::intrusive_ptr<void_continuation> this_(this); | |
| 666 | void (void_continuation::*ready)(shared_state_ptr const&) = | |
| 667 | &void_continuation::on_ready<Future>; | |
| 668 | ||
| 669 | shared_state_ptr const& state = | |
| 670 | traits::detail::get_shared_state(future); | |
| 671 | state->execute_deferred(); | |
| 672 | state->set_on_completed(util::bind(ready, std::move(this_), state)); | |
| 673 | } | |
| 674 | }; | |
| 675 | ||
| 676 | template <typename Future> | |
| 677 | inline typename traits::detail::shared_state_ptr<void>::type | |
| 678 | make_void_continuation(Future& future) | |
| 679 | { | |
| 680 | typedef detail::void_continuation void_shared_state; | |
| 681 | ||
| 682 | // create a continuation | |
| 683 | typename traits::detail::shared_state_ptr<void>::type p( | |
| 684 | new void_shared_state()); | |
| 685 | static_cast<void_shared_state*>(p.get())->attach(future); | |
| 686 | return p; | |
| 687 | } | |
| 688 | }}} | |
| 689 | ||
| 690 | #endif | |
| 691 |
Copyright (c) 2006-2012 Rogue Wave Software, Inc. All Rights Reserved.
Patents pending.