xref: /freebsd-src/contrib/llvm-project/libcxx/include/future (revision 7a6dacaca14b62ca4b74406814becb87a3fefac0)
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_FUTURE
11#define _LIBCPP_FUTURE
12
13/*
14    future synopsis
15
16namespace std
17{
18
19enum class future_errc
20{
21    future_already_retrieved = 1,
22    promise_already_satisfied,
23    no_state,
24    broken_promise
25};
26
27enum class launch
28{
29    async = 1,
30    deferred = 2,
31    any = async | deferred
32};
33
34enum class future_status
35{
36    ready,
37    timeout,
38    deferred
39};
40
41template <> struct is_error_code_enum<future_errc> : public true_type { };
42error_code make_error_code(future_errc e) noexcept;
43error_condition make_error_condition(future_errc e) noexcept;
44
45const error_category& future_category() noexcept;
46
47class future_error : public logic_error {
48public:
49    explicit future_error(future_errc e); // since C++17
50
51    const error_code& code() const noexcept;
52    const char*       what() const noexcept;
53
54private:
55    error_code ec_;             // exposition only
56};
57
58template <class R>
59class promise
60{
61public:
62    promise();
63    template <class Allocator>
64        promise(allocator_arg_t, const Allocator& a);
65    promise(promise&& rhs) noexcept;
66    promise(const promise& rhs) = delete;
67    ~promise();
68
69    // assignment
70    promise& operator=(promise&& rhs) noexcept;
71    promise& operator=(const promise& rhs) = delete;
72    void swap(promise& other) noexcept;
73
74    // retrieving the result
75    future<R> get_future();
76
77    // setting the result
78    void set_value(const R& r);
79    void set_value(R&& r);
80    void set_exception(exception_ptr p);
81
82    // setting the result with deferred notification
83    void set_value_at_thread_exit(const R& r);
84    void set_value_at_thread_exit(R&& r);
85    void set_exception_at_thread_exit(exception_ptr p);
86};
87
88template <class R>
89class promise<R&>
90{
91public:
92    promise();
93    template <class Allocator>
94        promise(allocator_arg_t, const Allocator& a);
95    promise(promise&& rhs) noexcept;
96    promise(const promise& rhs) = delete;
97    ~promise();
98
99    // assignment
100    promise& operator=(promise&& rhs) noexcept;
101    promise& operator=(const promise& rhs) = delete;
102    void swap(promise& other) noexcept;
103
104    // retrieving the result
105    future<R&> get_future();
106
107    // setting the result
108    void set_value(R& r);
109    void set_exception(exception_ptr p);
110
111    // setting the result with deferred notification
112    void set_value_at_thread_exit(R&);
113    void set_exception_at_thread_exit(exception_ptr p);
114};
115
116template <>
117class promise<void>
118{
119public:
120    promise();
121    template <class Allocator>
122        promise(allocator_arg_t, const Allocator& a);
123    promise(promise&& rhs) noexcept;
124    promise(const promise& rhs) = delete;
125    ~promise();
126
127    // assignment
128    promise& operator=(promise&& rhs) noexcept;
129    promise& operator=(const promise& rhs) = delete;
130    void swap(promise& other) noexcept;
131
132    // retrieving the result
133    future<void> get_future();
134
135    // setting the result
136    void set_value();
137    void set_exception(exception_ptr p);
138
139    // setting the result with deferred notification
140    void set_value_at_thread_exit();
141    void set_exception_at_thread_exit(exception_ptr p);
142};
143
144template <class R> void swap(promise<R>& x, promise<R>& y) noexcept;
145
146template <class R, class Alloc>
147    struct uses_allocator<promise<R>, Alloc> : public true_type {};
148
149template <class R>
150class future
151{
152public:
153    future() noexcept;
154    future(future&&) noexcept;
155    future(const future& rhs) = delete;
156    ~future();
157    future& operator=(const future& rhs) = delete;
158    future& operator=(future&&) noexcept;
159    shared_future<R> share() noexcept;
160
161    // retrieving the value
162    R get();
163
164    // functions to check state
165    bool valid() const noexcept;
166
167    void wait() const;
168    template <class Rep, class Period>
169        future_status
170        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
171    template <class Clock, class Duration>
172        future_status
173        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
174};
175
176template <class R>
177class future<R&>
178{
179public:
180    future() noexcept;
181    future(future&&) noexcept;
182    future(const future& rhs) = delete;
183    ~future();
184    future& operator=(const future& rhs) = delete;
185    future& operator=(future&&) noexcept;
186    shared_future<R&> share() noexcept;
187
188    // retrieving the value
189    R& get();
190
191    // functions to check state
192    bool valid() const noexcept;
193
194    void wait() const;
195    template <class Rep, class Period>
196        future_status
197        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
198    template <class Clock, class Duration>
199        future_status
200        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
201};
202
203template <>
204class future<void>
205{
206public:
207    future() noexcept;
208    future(future&&) noexcept;
209    future(const future& rhs) = delete;
210    ~future();
211    future& operator=(const future& rhs) = delete;
212    future& operator=(future&&) noexcept;
213    shared_future<void> share() noexcept;
214
215    // retrieving the value
216    void get();
217
218    // functions to check state
219    bool valid() const noexcept;
220
221    void wait() const;
222    template <class Rep, class Period>
223        future_status
224        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
225    template <class Clock, class Duration>
226        future_status
227        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
228};
229
230template <class R>
231class shared_future
232{
233public:
234    shared_future() noexcept;
235    shared_future(const shared_future& rhs);
236    shared_future(future<R>&&) noexcept;
237    shared_future(shared_future&& rhs) noexcept;
238    ~shared_future();
239    shared_future& operator=(const shared_future& rhs);
240    shared_future& operator=(shared_future&& rhs) noexcept;
241
242    // retrieving the value
243    const R& get() const;
244
245    // functions to check state
246    bool valid() const noexcept;
247
248    void wait() const;
249    template <class Rep, class Period>
250        future_status
251        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
252    template <class Clock, class Duration>
253        future_status
254        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
255};
256
257template <class R>
258class shared_future<R&>
259{
260public:
261    shared_future() noexcept;
262    shared_future(const shared_future& rhs);
263    shared_future(future<R&>&&) noexcept;
264    shared_future(shared_future&& rhs) noexcept;
265    ~shared_future();
266    shared_future& operator=(const shared_future& rhs);
267    shared_future& operator=(shared_future&& rhs) noexcept;
268
269    // retrieving the value
270    R& get() const;
271
272    // functions to check state
273    bool valid() const noexcept;
274
275    void wait() const;
276    template <class Rep, class Period>
277        future_status
278        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
279    template <class Clock, class Duration>
280        future_status
281        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
282};
283
284template <>
285class shared_future<void>
286{
287public:
288    shared_future() noexcept;
289    shared_future(const shared_future& rhs);
290    shared_future(future<void>&&) noexcept;
291    shared_future(shared_future&& rhs) noexcept;
292    ~shared_future();
293    shared_future& operator=(const shared_future& rhs);
294    shared_future& operator=(shared_future&& rhs) noexcept;
295
296    // retrieving the value
297    void get() const;
298
299    // functions to check state
300    bool valid() const noexcept;
301
302    void wait() const;
303    template <class Rep, class Period>
304        future_status
305        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
306    template <class Clock, class Duration>
307        future_status
308        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
309};
310
311template <class F, class... Args>
312  future<typename result_of<typename decay<F>::type(typename decay<Args>::type...)>::type>
313  async(F&& f, Args&&... args);
314
315template <class F, class... Args>
316  future<typename result_of<typename decay<F>::type(typename decay<Args>::type...)>::type>
317  async(launch policy, F&& f, Args&&... args);
318
319template <class> class packaged_task; // undefined
320
321template <class R, class... ArgTypes>
322class packaged_task<R(ArgTypes...)>
323{
324public:
325    typedef R result_type; // extension
326
327    // construction and destruction
328    packaged_task() noexcept;
329    template <class F>
330        explicit packaged_task(F&& f);
331    template <class F, class Allocator>
332        packaged_task(allocator_arg_t, const Allocator& a, F&& f);
333    ~packaged_task();
334
335    // no copy
336    packaged_task(const packaged_task&) = delete;
337    packaged_task& operator=(const packaged_task&) = delete;
338
339    // move support
340    packaged_task(packaged_task&& other) noexcept;
341    packaged_task& operator=(packaged_task&& other) noexcept;
342    void swap(packaged_task& other) noexcept;
343
344    bool valid() const noexcept;
345
346    // result retrieval
347    future<R> get_future();
348
349    // execution
350    void operator()(ArgTypes... );
351    void make_ready_at_thread_exit(ArgTypes...);
352
353    void reset();
354};
355
356template <class R>
357  void swap(packaged_task<R(ArgTypes...)&, packaged_task<R(ArgTypes...)>&) noexcept;
358
359template <class R, class Alloc> struct uses_allocator<packaged_task<R>, Alloc>;
360
361}  // std
362
363*/
364
365#include <__config>
366
367#ifdef _LIBCPP_HAS_NO_THREADS
368#  error "<future> is not supported since libc++ has been configured without support for threads."
369#endif
370
371#include <__assert> // all public C++ headers provide the assertion handler
372#include <__availability>
373#include <__chrono/duration.h>
374#include <__chrono/time_point.h>
375#include <__exception/exception_ptr.h>
376#include <__memory/addressof.h>
377#include <__memory/allocator.h>
378#include <__memory/allocator_arg_t.h>
379#include <__memory/allocator_destructor.h>
380#include <__memory/allocator_traits.h>
381#include <__memory/compressed_pair.h>
382#include <__memory/pointer_traits.h>
383#include <__memory/shared_ptr.h>
384#include <__memory/unique_ptr.h>
385#include <__memory/uses_allocator.h>
386#include <__system_error/error_category.h>
387#include <__system_error/error_code.h>
388#include <__system_error/error_condition.h>
389#include <__type_traits/aligned_storage.h>
390#include <__type_traits/strip_signature.h>
391#include <__utility/auto_cast.h>
392#include <__utility/forward.h>
393#include <__utility/move.h>
394#include <mutex>
395#include <new>
396#include <stdexcept>
397#include <thread>
398#include <version>
399
400#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
401#  pragma GCC system_header
402#endif
403
404_LIBCPP_BEGIN_NAMESPACE_STD
405
406// enum class future_errc
407_LIBCPP_DECLARE_STRONG_ENUM(future_errc){
408    future_already_retrieved = 1, promise_already_satisfied, no_state, broken_promise};
409_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(future_errc)
410
411template <>
412struct _LIBCPP_TEMPLATE_VIS is_error_code_enum<future_errc> : public true_type {};
413
414#ifdef _LIBCPP_CXX03_LANG
415template <>
416struct _LIBCPP_TEMPLATE_VIS is_error_code_enum<future_errc::__lx> : public true_type {};
417#endif
418
419// enum class launch
420_LIBCPP_DECLARE_STRONG_ENUM(launch){async = 1, deferred = 2, any = async | deferred};
421_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(launch)
422
423#ifndef _LIBCPP_CXX03_LANG
424
425typedef underlying_type<launch>::type __launch_underlying_type;
426
427inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR launch operator&(launch __x, launch __y) {
428  return static_cast<launch>(static_cast<__launch_underlying_type>(__x) & static_cast<__launch_underlying_type>(__y));
429}
430
431inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR launch operator|(launch __x, launch __y) {
432  return static_cast<launch>(static_cast<__launch_underlying_type>(__x) | static_cast<__launch_underlying_type>(__y));
433}
434
435inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR launch operator^(launch __x, launch __y) {
436  return static_cast<launch>(static_cast<__launch_underlying_type>(__x) ^ static_cast<__launch_underlying_type>(__y));
437}
438
439inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR launch operator~(launch __x) {
440  return static_cast<launch>(~static_cast<__launch_underlying_type>(__x) & 3);
441}
442
443inline _LIBCPP_HIDE_FROM_ABI launch& operator&=(launch& __x, launch __y) {
444  __x = __x & __y;
445  return __x;
446}
447
448inline _LIBCPP_HIDE_FROM_ABI launch& operator|=(launch& __x, launch __y) {
449  __x = __x | __y;
450  return __x;
451}
452
453inline _LIBCPP_HIDE_FROM_ABI launch& operator^=(launch& __x, launch __y) {
454  __x = __x ^ __y;
455  return __x;
456}
457
458#endif // !_LIBCPP_CXX03_LANG
459
460// enum class future_status
461_LIBCPP_DECLARE_STRONG_ENUM(future_status){ready, timeout, deferred};
462_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(future_status)
463
464_LIBCPP_EXPORTED_FROM_ABI const error_category& future_category() _NOEXCEPT;
465
466inline _LIBCPP_HIDE_FROM_ABI error_code make_error_code(future_errc __e) _NOEXCEPT {
467  return error_code(static_cast<int>(__e), future_category());
468}
469
470inline _LIBCPP_HIDE_FROM_ABI error_condition make_error_condition(future_errc __e) _NOEXCEPT {
471  return error_condition(static_cast<int>(__e), future_category());
472}
473
474_LIBCPP_NORETURN inline _LIBCPP_HIDE_FROM_ABI void __throw_future_error(future_errc __ev);
475
476class _LIBCPP_EXPORTED_FROM_ABI future_error : public logic_error {
477  error_code __ec_;
478
479  future_error(error_code);
480  friend void __throw_future_error(future_errc);
481  template <class>
482  friend class promise;
483
484public:
485#if _LIBCPP_STD_VER >= 17
486  _LIBCPP_HIDE_FROM_ABI explicit future_error(future_errc __ec) : future_error(std::make_error_code(__ec)) {}
487#endif
488
489  _LIBCPP_HIDE_FROM_ABI const error_code& code() const _NOEXCEPT { return __ec_; }
490
491  _LIBCPP_HIDE_FROM_ABI future_error(const future_error&) _NOEXCEPT = default;
492  ~future_error() _NOEXCEPT override;
493};
494
495// Declared above std::future_error
496void __throw_future_error(future_errc __ev) {
497#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
498  throw future_error(make_error_code(__ev));
499#else
500  (void)__ev;
501  _LIBCPP_VERBOSE_ABORT("future_error was thrown in -fno-exceptions mode");
502#endif
503}
504
505class _LIBCPP_EXPORTED_FROM_ABI __assoc_sub_state : public __shared_count {
506protected:
507  exception_ptr __exception_;
508  mutable mutex __mut_;
509  mutable condition_variable __cv_;
510  unsigned __state_;
511
512  void __on_zero_shared() _NOEXCEPT override;
513  void __sub_wait(unique_lock<mutex>& __lk);
514
515public:
516  enum { __constructed = 1, __future_attached = 2, ready = 4, deferred = 8 };
517
518  _LIBCPP_HIDE_FROM_ABI __assoc_sub_state() : __state_(0) {}
519
520  _LIBCPP_HIDE_FROM_ABI bool __has_value() const { return (__state_ & __constructed) || (__exception_ != nullptr); }
521
522  _LIBCPP_HIDE_FROM_ABI void __attach_future() {
523    lock_guard<mutex> __lk(__mut_);
524    bool __has_future_attached = (__state_ & __future_attached) != 0;
525    if (__has_future_attached)
526      __throw_future_error(future_errc::future_already_retrieved);
527    this->__add_shared();
528    __state_ |= __future_attached;
529  }
530
531  _LIBCPP_HIDE_FROM_ABI void __set_deferred() { __state_ |= deferred; }
532
533  void __make_ready();
534  _LIBCPP_HIDE_FROM_ABI bool __is_ready() const { return (__state_ & ready) != 0; }
535
536  void set_value();
537  void set_value_at_thread_exit();
538
539  void set_exception(exception_ptr __p);
540  void set_exception_at_thread_exit(exception_ptr __p);
541
542  void copy();
543
544  void wait();
545  template <class _Rep, class _Period>
546  future_status _LIBCPP_HIDE_FROM_ABI wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const;
547  template <class _Clock, class _Duration>
548  _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS future_status
549  wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const;
550
551  virtual void __execute();
552};
553
554template <class _Clock, class _Duration>
555future_status __assoc_sub_state::wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
556  unique_lock<mutex> __lk(__mut_);
557  if (__state_ & deferred)
558    return future_status::deferred;
559  while (!(__state_ & ready) && _Clock::now() < __abs_time)
560    __cv_.wait_until(__lk, __abs_time);
561  if (__state_ & ready)
562    return future_status::ready;
563  return future_status::timeout;
564}
565
566template <class _Rep, class _Period>
567inline future_status __assoc_sub_state::wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
568  return wait_until(chrono::steady_clock::now() + __rel_time);
569}
570
571template <class _Rp>
572class _LIBCPP_HIDDEN __assoc_state : public __assoc_sub_state {
573  typedef __assoc_sub_state base;
574  _LIBCPP_SUPPRESS_DEPRECATED_PUSH
575  typedef typename aligned_storage<sizeof(_Rp), _LIBCPP_ALIGNOF(_Rp)>::type _Up;
576  _LIBCPP_SUPPRESS_DEPRECATED_POP
577
578protected:
579  _Up __value_;
580
581  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override;
582
583public:
584  template <class _Arg>
585  _LIBCPP_HIDE_FROM_ABI void set_value(_Arg&& __arg);
586
587  template <class _Arg>
588  _LIBCPP_HIDE_FROM_ABI void set_value_at_thread_exit(_Arg&& __arg);
589
590  _LIBCPP_HIDE_FROM_ABI _Rp move();
591  _LIBCPP_HIDE_FROM_ABI __add_lvalue_reference_t<_Rp> copy();
592};
593
594template <class _Rp>
595void __assoc_state<_Rp>::__on_zero_shared() _NOEXCEPT {
596  if (this->__state_ & base::__constructed)
597    reinterpret_cast<_Rp*>(&__value_)->~_Rp();
598  delete this;
599}
600
601template <class _Rp>
602template <class _Arg>
603void __assoc_state<_Rp>::set_value(_Arg&& __arg) {
604  unique_lock<mutex> __lk(this->__mut_);
605  if (this->__has_value())
606    __throw_future_error(future_errc::promise_already_satisfied);
607  ::new ((void*)&__value_) _Rp(std::forward<_Arg>(__arg));
608  this->__state_ |= base::__constructed | base::ready;
609  __cv_.notify_all();
610}
611
612template <class _Rp>
613template <class _Arg>
614void __assoc_state<_Rp>::set_value_at_thread_exit(_Arg&& __arg) {
615  unique_lock<mutex> __lk(this->__mut_);
616  if (this->__has_value())
617    __throw_future_error(future_errc::promise_already_satisfied);
618  ::new ((void*)&__value_) _Rp(std::forward<_Arg>(__arg));
619  this->__state_ |= base::__constructed;
620  __thread_local_data()->__make_ready_at_thread_exit(this);
621}
622
623template <class _Rp>
624_Rp __assoc_state<_Rp>::move() {
625  unique_lock<mutex> __lk(this->__mut_);
626  this->__sub_wait(__lk);
627  if (this->__exception_ != nullptr)
628    std::rethrow_exception(this->__exception_);
629  return std::move(*reinterpret_cast<_Rp*>(&__value_));
630}
631
632template <class _Rp>
633__add_lvalue_reference_t<_Rp> __assoc_state<_Rp>::copy() {
634  unique_lock<mutex> __lk(this->__mut_);
635  this->__sub_wait(__lk);
636  if (this->__exception_ != nullptr)
637    std::rethrow_exception(this->__exception_);
638  return *reinterpret_cast<_Rp*>(&__value_);
639}
640
641template <class _Rp>
642class __assoc_state<_Rp&> : public __assoc_sub_state {
643  typedef __assoc_sub_state base;
644  typedef _Rp* _Up;
645
646protected:
647  _Up __value_;
648
649  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override;
650
651public:
652  _LIBCPP_HIDE_FROM_ABI void set_value(_Rp& __arg);
653  _LIBCPP_HIDE_FROM_ABI void set_value_at_thread_exit(_Rp& __arg);
654
655  _LIBCPP_HIDE_FROM_ABI _Rp& copy();
656};
657
658template <class _Rp>
659void __assoc_state<_Rp&>::__on_zero_shared() _NOEXCEPT {
660  delete this;
661}
662
663template <class _Rp>
664void __assoc_state<_Rp&>::set_value(_Rp& __arg) {
665  unique_lock<mutex> __lk(this->__mut_);
666  if (this->__has_value())
667    __throw_future_error(future_errc::promise_already_satisfied);
668  __value_ = std::addressof(__arg);
669  this->__state_ |= base::__constructed | base::ready;
670  __cv_.notify_all();
671}
672
673template <class _Rp>
674void __assoc_state<_Rp&>::set_value_at_thread_exit(_Rp& __arg) {
675  unique_lock<mutex> __lk(this->__mut_);
676  if (this->__has_value())
677    __throw_future_error(future_errc::promise_already_satisfied);
678  __value_ = std::addressof(__arg);
679  this->__state_ |= base::__constructed;
680  __thread_local_data()->__make_ready_at_thread_exit(this);
681}
682
683template <class _Rp>
684_Rp& __assoc_state<_Rp&>::copy() {
685  unique_lock<mutex> __lk(this->__mut_);
686  this->__sub_wait(__lk);
687  if (this->__exception_ != nullptr)
688    std::rethrow_exception(this->__exception_);
689  return *__value_;
690}
691
692template <class _Rp, class _Alloc>
693class __assoc_state_alloc : public __assoc_state<_Rp> {
694  typedef __assoc_state<_Rp> base;
695  _Alloc __alloc_;
696
697  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __on_zero_shared() _NOEXCEPT;
698
699public:
700  _LIBCPP_HIDE_FROM_ABI explicit __assoc_state_alloc(const _Alloc& __a) : __alloc_(__a) {}
701};
702
703template <class _Rp, class _Alloc>
704void __assoc_state_alloc<_Rp, _Alloc>::__on_zero_shared() _NOEXCEPT {
705  if (this->__state_ & base::__constructed)
706    reinterpret_cast<_Rp*>(std::addressof(this->__value_))->~_Rp();
707  typedef typename __allocator_traits_rebind<_Alloc, __assoc_state_alloc>::type _Al;
708  typedef allocator_traits<_Al> _ATraits;
709  typedef pointer_traits<typename _ATraits::pointer> _PTraits;
710  _Al __a(__alloc_);
711  this->~__assoc_state_alloc();
712  __a.deallocate(_PTraits::pointer_to(*this), 1);
713}
714
715template <class _Rp, class _Alloc>
716class __assoc_state_alloc<_Rp&, _Alloc> : public __assoc_state<_Rp&> {
717  typedef __assoc_state<_Rp&> base;
718  _Alloc __alloc_;
719
720  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __on_zero_shared() _NOEXCEPT;
721
722public:
723  _LIBCPP_HIDE_FROM_ABI explicit __assoc_state_alloc(const _Alloc& __a) : __alloc_(__a) {}
724};
725
726template <class _Rp, class _Alloc>
727void __assoc_state_alloc<_Rp&, _Alloc>::__on_zero_shared() _NOEXCEPT {
728  typedef typename __allocator_traits_rebind<_Alloc, __assoc_state_alloc>::type _Al;
729  typedef allocator_traits<_Al> _ATraits;
730  typedef pointer_traits<typename _ATraits::pointer> _PTraits;
731  _Al __a(__alloc_);
732  this->~__assoc_state_alloc();
733  __a.deallocate(_PTraits::pointer_to(*this), 1);
734}
735
736template <class _Alloc>
737class __assoc_sub_state_alloc : public __assoc_sub_state {
738  typedef __assoc_sub_state base;
739  _Alloc __alloc_;
740
741  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override;
742
743public:
744  _LIBCPP_HIDE_FROM_ABI explicit __assoc_sub_state_alloc(const _Alloc& __a) : __alloc_(__a) {}
745};
746
747template <class _Alloc>
748void __assoc_sub_state_alloc<_Alloc>::__on_zero_shared() _NOEXCEPT {
749  typedef typename __allocator_traits_rebind<_Alloc, __assoc_sub_state_alloc>::type _Al;
750  typedef allocator_traits<_Al> _ATraits;
751  typedef pointer_traits<typename _ATraits::pointer> _PTraits;
752  _Al __a(__alloc_);
753  this->~__assoc_sub_state_alloc();
754  __a.deallocate(_PTraits::pointer_to(*this), 1);
755}
756
757template <class _Rp, class _Fp>
758class __deferred_assoc_state : public __assoc_state<_Rp> {
759  typedef __assoc_state<_Rp> base;
760
761  _Fp __func_;
762
763public:
764  _LIBCPP_HIDE_FROM_ABI explicit __deferred_assoc_state(_Fp&& __f);
765
766  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __execute();
767};
768
769template <class _Rp, class _Fp>
770inline __deferred_assoc_state<_Rp, _Fp>::__deferred_assoc_state(_Fp&& __f) : __func_(std::forward<_Fp>(__f)) {
771  this->__set_deferred();
772}
773
774template <class _Rp, class _Fp>
775void __deferred_assoc_state<_Rp, _Fp>::__execute() {
776#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
777  try {
778#endif // _LIBCPP_HAS_NO_EXCEPTIONS
779    this->set_value(__func_());
780#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
781  } catch (...) {
782    this->set_exception(current_exception());
783  }
784#endif // _LIBCPP_HAS_NO_EXCEPTIONS
785}
786
787template <class _Fp>
788class __deferred_assoc_state<void, _Fp> : public __assoc_sub_state {
789  typedef __assoc_sub_state base;
790
791  _Fp __func_;
792
793public:
794  _LIBCPP_HIDE_FROM_ABI explicit __deferred_assoc_state(_Fp&& __f);
795
796  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __execute() override;
797};
798
799template <class _Fp>
800inline __deferred_assoc_state<void, _Fp>::__deferred_assoc_state(_Fp&& __f) : __func_(std::forward<_Fp>(__f)) {
801  this->__set_deferred();
802}
803
804template <class _Fp>
805void __deferred_assoc_state<void, _Fp>::__execute() {
806#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
807  try {
808#endif // _LIBCPP_HAS_NO_EXCEPTIONS
809    __func_();
810    this->set_value();
811#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
812  } catch (...) {
813    this->set_exception(current_exception());
814  }
815#endif // _LIBCPP_HAS_NO_EXCEPTIONS
816}
817
818template <class _Rp, class _Fp>
819class __async_assoc_state : public __assoc_state<_Rp> {
820  typedef __assoc_state<_Rp> base;
821
822  _Fp __func_;
823
824  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __on_zero_shared() _NOEXCEPT;
825
826public:
827  _LIBCPP_HIDE_FROM_ABI explicit __async_assoc_state(_Fp&& __f);
828
829  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __execute();
830};
831
832template <class _Rp, class _Fp>
833inline __async_assoc_state<_Rp, _Fp>::__async_assoc_state(_Fp&& __f) : __func_(std::forward<_Fp>(__f)) {}
834
835template <class _Rp, class _Fp>
836void __async_assoc_state<_Rp, _Fp>::__execute() {
837#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
838  try {
839#endif // _LIBCPP_HAS_NO_EXCEPTIONS
840    this->set_value(__func_());
841#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
842  } catch (...) {
843    this->set_exception(current_exception());
844  }
845#endif // _LIBCPP_HAS_NO_EXCEPTIONS
846}
847
848template <class _Rp, class _Fp>
849void __async_assoc_state<_Rp, _Fp>::__on_zero_shared() _NOEXCEPT {
850  this->wait();
851  base::__on_zero_shared();
852}
853
854template <class _Fp>
855class __async_assoc_state<void, _Fp> : public __assoc_sub_state {
856  typedef __assoc_sub_state base;
857
858  _Fp __func_;
859
860  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override;
861
862public:
863  _LIBCPP_HIDE_FROM_ABI explicit __async_assoc_state(_Fp&& __f);
864
865  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __execute() override;
866};
867
868template <class _Fp>
869inline __async_assoc_state<void, _Fp>::__async_assoc_state(_Fp&& __f) : __func_(std::forward<_Fp>(__f)) {}
870
871template <class _Fp>
872void __async_assoc_state<void, _Fp>::__execute() {
873#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
874  try {
875#endif // _LIBCPP_HAS_NO_EXCEPTIONS
876    __func_();
877    this->set_value();
878#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
879  } catch (...) {
880    this->set_exception(current_exception());
881  }
882#endif // _LIBCPP_HAS_NO_EXCEPTIONS
883}
884
885template <class _Fp>
886void __async_assoc_state<void, _Fp>::__on_zero_shared() _NOEXCEPT {
887  this->wait();
888  base::__on_zero_shared();
889}
890
891template <class _Rp>
892class _LIBCPP_TEMPLATE_VIS promise;
893template <class _Rp>
894class _LIBCPP_TEMPLATE_VIS shared_future;
895
896// future
897
898template <class _Rp>
899class _LIBCPP_TEMPLATE_VIS future;
900
901template <class _Rp, class _Fp>
902_LIBCPP_HIDE_FROM_ABI future<_Rp> __make_deferred_assoc_state(_Fp&& __f);
903
904template <class _Rp, class _Fp>
905_LIBCPP_HIDE_FROM_ABI future<_Rp> __make_async_assoc_state(_Fp&& __f);
906
907template <class _Rp>
908class _LIBCPP_TEMPLATE_VIS future {
909  __assoc_state<_Rp>* __state_;
910
911  explicit _LIBCPP_HIDE_FROM_ABI future(__assoc_state<_Rp>* __state);
912
913  template <class>
914  friend class promise;
915  template <class>
916  friend class shared_future;
917
918  template <class _R1, class _Fp>
919  friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
920  template <class _R1, class _Fp>
921  friend future<_R1> __make_async_assoc_state(_Fp&& __f);
922
923public:
924  _LIBCPP_HIDE_FROM_ABI future() _NOEXCEPT : __state_(nullptr) {}
925  _LIBCPP_HIDE_FROM_ABI future(future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
926  future(const future&)            = delete;
927  future& operator=(const future&) = delete;
928  _LIBCPP_HIDE_FROM_ABI future& operator=(future&& __rhs) _NOEXCEPT {
929    future(std::move(__rhs)).swap(*this);
930    return *this;
931  }
932
933  _LIBCPP_HIDE_FROM_ABI ~future();
934  _LIBCPP_HIDE_FROM_ABI shared_future<_Rp> share() _NOEXCEPT;
935
936  // retrieving the value
937  _LIBCPP_HIDE_FROM_ABI _Rp get();
938
939  _LIBCPP_HIDE_FROM_ABI void swap(future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
940
941  // functions to check state
942  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
943
944  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
945  template <class _Rep, class _Period>
946  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
947    return __state_->wait_for(__rel_time);
948  }
949  template <class _Clock, class _Duration>
950  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
951    return __state_->wait_until(__abs_time);
952  }
953};
954
955template <class _Rp>
956future<_Rp>::future(__assoc_state<_Rp>* __state) : __state_(__state) {
957  __state_->__attach_future();
958}
959
960struct __release_shared_count {
961  _LIBCPP_HIDE_FROM_ABI void operator()(__shared_count* __p) { __p->__release_shared(); }
962};
963
964template <class _Rp>
965future<_Rp>::~future() {
966  if (__state_)
967    __state_->__release_shared();
968}
969
970template <class _Rp>
971_Rp future<_Rp>::get() {
972  unique_ptr<__shared_count, __release_shared_count> __guard(__state_);
973  __assoc_state<_Rp>* __s = __state_;
974  __state_                = nullptr;
975  return __s->move();
976}
977
978template <class _Rp>
979class _LIBCPP_TEMPLATE_VIS future<_Rp&> {
980  __assoc_state<_Rp&>* __state_;
981
982  explicit _LIBCPP_HIDE_FROM_ABI future(__assoc_state<_Rp&>* __state);
983
984  template <class>
985  friend class promise;
986  template <class>
987  friend class shared_future;
988
989  template <class _R1, class _Fp>
990  friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
991  template <class _R1, class _Fp>
992  friend future<_R1> __make_async_assoc_state(_Fp&& __f);
993
994public:
995  _LIBCPP_HIDE_FROM_ABI future() _NOEXCEPT : __state_(nullptr) {}
996  _LIBCPP_HIDE_FROM_ABI future(future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
997  future(const future&)            = delete;
998  future& operator=(const future&) = delete;
999  _LIBCPP_HIDE_FROM_ABI future& operator=(future&& __rhs) _NOEXCEPT {
1000    future(std::move(__rhs)).swap(*this);
1001    return *this;
1002  }
1003
1004  _LIBCPP_HIDE_FROM_ABI ~future();
1005  _LIBCPP_HIDE_FROM_ABI shared_future<_Rp&> share() _NOEXCEPT;
1006
1007  // retrieving the value
1008  _LIBCPP_HIDE_FROM_ABI _Rp& get();
1009
1010  _LIBCPP_HIDE_FROM_ABI void swap(future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1011
1012  // functions to check state
1013  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
1014
1015  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
1016  template <class _Rep, class _Period>
1017  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
1018    return __state_->wait_for(__rel_time);
1019  }
1020  template <class _Clock, class _Duration>
1021  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
1022    return __state_->wait_until(__abs_time);
1023  }
1024};
1025
1026template <class _Rp>
1027future<_Rp&>::future(__assoc_state<_Rp&>* __state) : __state_(__state) {
1028  __state_->__attach_future();
1029}
1030
1031template <class _Rp>
1032future<_Rp&>::~future() {
1033  if (__state_)
1034    __state_->__release_shared();
1035}
1036
1037template <class _Rp>
1038_Rp& future<_Rp&>::get() {
1039  unique_ptr<__shared_count, __release_shared_count> __guard(__state_);
1040  __assoc_state<_Rp&>* __s = __state_;
1041  __state_                 = nullptr;
1042  return __s->copy();
1043}
1044
1045template <>
1046class _LIBCPP_EXPORTED_FROM_ABI future<void> {
1047  __assoc_sub_state* __state_;
1048
1049  explicit future(__assoc_sub_state* __state);
1050
1051  template <class>
1052  friend class promise;
1053  template <class>
1054  friend class shared_future;
1055
1056  template <class _R1, class _Fp>
1057  friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
1058  template <class _R1, class _Fp>
1059  friend future<_R1> __make_async_assoc_state(_Fp&& __f);
1060
1061public:
1062  _LIBCPP_HIDE_FROM_ABI future() _NOEXCEPT : __state_(nullptr) {}
1063  _LIBCPP_HIDE_FROM_ABI future(future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
1064  future(const future&)            = delete;
1065  future& operator=(const future&) = delete;
1066  _LIBCPP_HIDE_FROM_ABI future& operator=(future&& __rhs) _NOEXCEPT {
1067    future(std::move(__rhs)).swap(*this);
1068    return *this;
1069  }
1070
1071  ~future();
1072  _LIBCPP_HIDE_FROM_ABI shared_future<void> share() _NOEXCEPT;
1073
1074  // retrieving the value
1075  void get();
1076
1077  _LIBCPP_HIDE_FROM_ABI void swap(future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1078
1079  // functions to check state
1080  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
1081
1082  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
1083  template <class _Rep, class _Period>
1084  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
1085    return __state_->wait_for(__rel_time);
1086  }
1087  template <class _Clock, class _Duration>
1088  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
1089    return __state_->wait_until(__abs_time);
1090  }
1091};
1092
1093template <class _Rp>
1094inline _LIBCPP_HIDE_FROM_ABI void swap(future<_Rp>& __x, future<_Rp>& __y) _NOEXCEPT {
1095  __x.swap(__y);
1096}
1097
1098// promise<R>
1099
1100template <class _Callable>
1101class packaged_task;
1102
1103template <class _Rp>
1104class _LIBCPP_TEMPLATE_VIS promise {
1105  __assoc_state<_Rp>* __state_;
1106
1107  _LIBCPP_HIDE_FROM_ABI explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
1108
1109  template <class>
1110  friend class packaged_task;
1111
1112public:
1113  _LIBCPP_HIDE_FROM_ABI promise();
1114  template <class _Alloc>
1115  _LIBCPP_HIDE_FROM_ABI promise(allocator_arg_t, const _Alloc& __a);
1116  _LIBCPP_HIDE_FROM_ABI promise(promise&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
1117  promise(const promise& __rhs) = delete;
1118  _LIBCPP_HIDE_FROM_ABI ~promise();
1119
1120  // assignment
1121  _LIBCPP_HIDE_FROM_ABI promise& operator=(promise&& __rhs) _NOEXCEPT {
1122    promise(std::move(__rhs)).swap(*this);
1123    return *this;
1124  }
1125  promise& operator=(const promise& __rhs) = delete;
1126
1127  _LIBCPP_HIDE_FROM_ABI void swap(promise& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1128
1129  // retrieving the result
1130  _LIBCPP_HIDE_FROM_ABI future<_Rp> get_future();
1131
1132  // setting the result
1133  _LIBCPP_HIDE_FROM_ABI void set_value(const _Rp& __r);
1134  _LIBCPP_HIDE_FROM_ABI void set_value(_Rp&& __r);
1135  _LIBCPP_HIDE_FROM_ABI void set_exception(exception_ptr __p);
1136
1137  // setting the result with deferred notification
1138  _LIBCPP_HIDE_FROM_ABI void set_value_at_thread_exit(const _Rp& __r);
1139  _LIBCPP_HIDE_FROM_ABI void set_value_at_thread_exit(_Rp&& __r);
1140  _LIBCPP_HIDE_FROM_ABI void set_exception_at_thread_exit(exception_ptr __p);
1141};
1142
1143template <class _Rp>
1144promise<_Rp>::promise() : __state_(new __assoc_state<_Rp>) {}
1145
1146template <class _Rp>
1147template <class _Alloc>
1148promise<_Rp>::promise(allocator_arg_t, const _Alloc& __a0) {
1149  typedef __assoc_state_alloc<_Rp, _Alloc> _State;
1150  typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
1151  typedef __allocator_destructor<_A2> _D2;
1152  _A2 __a(__a0);
1153  unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
1154  ::new ((void*)std::addressof(*__hold.get())) _State(__a0);
1155  __state_ = std::addressof(*__hold.release());
1156}
1157
1158template <class _Rp>
1159promise<_Rp>::~promise() {
1160  if (__state_) {
1161    if (!__state_->__has_value() && __state_->use_count() > 1)
1162      __state_->set_exception(make_exception_ptr(future_error(make_error_code(future_errc::broken_promise))));
1163    __state_->__release_shared();
1164  }
1165}
1166
1167template <class _Rp>
1168future<_Rp> promise<_Rp>::get_future() {
1169  if (__state_ == nullptr)
1170    __throw_future_error(future_errc::no_state);
1171  return future<_Rp>(__state_);
1172}
1173
1174template <class _Rp>
1175void promise<_Rp>::set_value(const _Rp& __r) {
1176  if (__state_ == nullptr)
1177    __throw_future_error(future_errc::no_state);
1178  __state_->set_value(__r);
1179}
1180
1181template <class _Rp>
1182void promise<_Rp>::set_value(_Rp&& __r) {
1183  if (__state_ == nullptr)
1184    __throw_future_error(future_errc::no_state);
1185  __state_->set_value(std::move(__r));
1186}
1187
1188template <class _Rp>
1189void promise<_Rp>::set_exception(exception_ptr __p) {
1190  _LIBCPP_ASSERT_NON_NULL(__p != nullptr, "promise::set_exception: received nullptr");
1191  if (__state_ == nullptr)
1192    __throw_future_error(future_errc::no_state);
1193  __state_->set_exception(__p);
1194}
1195
1196template <class _Rp>
1197void promise<_Rp>::set_value_at_thread_exit(const _Rp& __r) {
1198  if (__state_ == nullptr)
1199    __throw_future_error(future_errc::no_state);
1200  __state_->set_value_at_thread_exit(__r);
1201}
1202
1203template <class _Rp>
1204void promise<_Rp>::set_value_at_thread_exit(_Rp&& __r) {
1205  if (__state_ == nullptr)
1206    __throw_future_error(future_errc::no_state);
1207  __state_->set_value_at_thread_exit(std::move(__r));
1208}
1209
1210template <class _Rp>
1211void promise<_Rp>::set_exception_at_thread_exit(exception_ptr __p) {
1212  _LIBCPP_ASSERT_NON_NULL(__p != nullptr, "promise::set_exception_at_thread_exit: received nullptr");
1213  if (__state_ == nullptr)
1214    __throw_future_error(future_errc::no_state);
1215  __state_->set_exception_at_thread_exit(__p);
1216}
1217
1218// promise<R&>
1219
1220template <class _Rp>
1221class _LIBCPP_TEMPLATE_VIS promise<_Rp&> {
1222  __assoc_state<_Rp&>* __state_;
1223
1224  _LIBCPP_HIDE_FROM_ABI explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
1225
1226  template <class>
1227  friend class packaged_task;
1228
1229public:
1230  _LIBCPP_HIDE_FROM_ABI promise();
1231  template <class _Allocator>
1232  _LIBCPP_HIDE_FROM_ABI promise(allocator_arg_t, const _Allocator& __a);
1233  _LIBCPP_HIDE_FROM_ABI promise(promise&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
1234  promise(const promise& __rhs) = delete;
1235  _LIBCPP_HIDE_FROM_ABI ~promise();
1236
1237  // assignment
1238  _LIBCPP_HIDE_FROM_ABI promise& operator=(promise&& __rhs) _NOEXCEPT {
1239    promise(std::move(__rhs)).swap(*this);
1240    return *this;
1241  }
1242  promise& operator=(const promise& __rhs) = delete;
1243
1244  _LIBCPP_HIDE_FROM_ABI void swap(promise& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1245
1246  // retrieving the result
1247  _LIBCPP_HIDE_FROM_ABI future<_Rp&> get_future();
1248
1249  // setting the result
1250  _LIBCPP_HIDE_FROM_ABI void set_value(_Rp& __r);
1251  _LIBCPP_HIDE_FROM_ABI void set_exception(exception_ptr __p);
1252
1253  // setting the result with deferred notification
1254  _LIBCPP_HIDE_FROM_ABI void set_value_at_thread_exit(_Rp&);
1255  _LIBCPP_HIDE_FROM_ABI void set_exception_at_thread_exit(exception_ptr __p);
1256};
1257
1258template <class _Rp>
1259promise<_Rp&>::promise() : __state_(new __assoc_state<_Rp&>) {}
1260
1261template <class _Rp>
1262template <class _Alloc>
1263promise<_Rp&>::promise(allocator_arg_t, const _Alloc& __a0) {
1264  typedef __assoc_state_alloc<_Rp&, _Alloc> _State;
1265  typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
1266  typedef __allocator_destructor<_A2> _D2;
1267  _A2 __a(__a0);
1268  unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
1269  ::new ((void*)std::addressof(*__hold.get())) _State(__a0);
1270  __state_ = std::addressof(*__hold.release());
1271}
1272
1273template <class _Rp>
1274promise<_Rp&>::~promise() {
1275  if (__state_) {
1276    if (!__state_->__has_value() && __state_->use_count() > 1)
1277      __state_->set_exception(make_exception_ptr(future_error(make_error_code(future_errc::broken_promise))));
1278    __state_->__release_shared();
1279  }
1280}
1281
1282template <class _Rp>
1283future<_Rp&> promise<_Rp&>::get_future() {
1284  if (__state_ == nullptr)
1285    __throw_future_error(future_errc::no_state);
1286  return future<_Rp&>(__state_);
1287}
1288
1289template <class _Rp>
1290void promise<_Rp&>::set_value(_Rp& __r) {
1291  if (__state_ == nullptr)
1292    __throw_future_error(future_errc::no_state);
1293  __state_->set_value(__r);
1294}
1295
1296template <class _Rp>
1297void promise<_Rp&>::set_exception(exception_ptr __p) {
1298  _LIBCPP_ASSERT_NON_NULL(__p != nullptr, "promise::set_exception: received nullptr");
1299  if (__state_ == nullptr)
1300    __throw_future_error(future_errc::no_state);
1301  __state_->set_exception(__p);
1302}
1303
1304template <class _Rp>
1305void promise<_Rp&>::set_value_at_thread_exit(_Rp& __r) {
1306  if (__state_ == nullptr)
1307    __throw_future_error(future_errc::no_state);
1308  __state_->set_value_at_thread_exit(__r);
1309}
1310
1311template <class _Rp>
1312void promise<_Rp&>::set_exception_at_thread_exit(exception_ptr __p) {
1313  _LIBCPP_ASSERT_NON_NULL(__p != nullptr, "promise::set_exception_at_thread_exit: received nullptr");
1314  if (__state_ == nullptr)
1315    __throw_future_error(future_errc::no_state);
1316  __state_->set_exception_at_thread_exit(__p);
1317}
1318
1319// promise<void>
1320
1321template <>
1322class _LIBCPP_EXPORTED_FROM_ABI promise<void> {
1323  __assoc_sub_state* __state_;
1324
1325  _LIBCPP_HIDE_FROM_ABI explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
1326
1327  template <class>
1328  friend class packaged_task;
1329
1330public:
1331  promise();
1332  template <class _Allocator>
1333  _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS promise(allocator_arg_t, const _Allocator& __a);
1334  _LIBCPP_HIDE_FROM_ABI promise(promise&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
1335  promise(const promise& __rhs) = delete;
1336  ~promise();
1337
1338  // assignment
1339  _LIBCPP_HIDE_FROM_ABI promise& operator=(promise&& __rhs) _NOEXCEPT {
1340    promise(std::move(__rhs)).swap(*this);
1341    return *this;
1342  }
1343  promise& operator=(const promise& __rhs) = delete;
1344
1345  _LIBCPP_HIDE_FROM_ABI void swap(promise& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1346
1347  // retrieving the result
1348  future<void> get_future();
1349
1350  // setting the result
1351  void set_value();
1352  void set_exception(exception_ptr __p);
1353
1354  // setting the result with deferred notification
1355  void set_value_at_thread_exit();
1356  void set_exception_at_thread_exit(exception_ptr __p);
1357};
1358
1359template <class _Alloc>
1360promise<void>::promise(allocator_arg_t, const _Alloc& __a0) {
1361  typedef __assoc_sub_state_alloc<_Alloc> _State;
1362  typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
1363  typedef __allocator_destructor<_A2> _D2;
1364  _A2 __a(__a0);
1365  unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
1366  ::new ((void*)std::addressof(*__hold.get())) _State(__a0);
1367  __state_ = std::addressof(*__hold.release());
1368}
1369
1370template <class _Rp>
1371inline _LIBCPP_HIDE_FROM_ABI void swap(promise<_Rp>& __x, promise<_Rp>& __y) _NOEXCEPT {
1372  __x.swap(__y);
1373}
1374
1375template <class _Rp, class _Alloc>
1376struct _LIBCPP_TEMPLATE_VIS uses_allocator<promise<_Rp>, _Alloc> : public true_type {};
1377
1378// packaged_task
1379
1380template <class _Fp>
1381class __packaged_task_base;
1382
1383template <class _Rp, class... _ArgTypes>
1384class __packaged_task_base<_Rp(_ArgTypes...)> {
1385  __packaged_task_base(const __packaged_task_base&);
1386  __packaged_task_base& operator=(const __packaged_task_base&);
1387
1388public:
1389  _LIBCPP_HIDE_FROM_ABI __packaged_task_base() {}
1390  _LIBCPP_HIDE_FROM_ABI_VIRTUAL
1391  virtual ~__packaged_task_base() {}
1392  virtual void __move_to(__packaged_task_base*) _NOEXCEPT = 0;
1393  virtual void destroy()                                  = 0;
1394  virtual void destroy_deallocate()                       = 0;
1395  virtual _Rp operator()(_ArgTypes&&...)                  = 0;
1396};
1397
1398template <class _FD, class _Alloc, class _FB>
1399class __packaged_task_func;
1400
1401template <class _Fp, class _Alloc, class _Rp, class... _ArgTypes>
1402class __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)> : public __packaged_task_base<_Rp(_ArgTypes...)> {
1403  __compressed_pair<_Fp, _Alloc> __f_;
1404
1405public:
1406  _LIBCPP_HIDE_FROM_ABI explicit __packaged_task_func(const _Fp& __f) : __f_(__f, __default_init_tag()) {}
1407  _LIBCPP_HIDE_FROM_ABI explicit __packaged_task_func(_Fp&& __f) : __f_(std::move(__f), __default_init_tag()) {}
1408  _LIBCPP_HIDE_FROM_ABI __packaged_task_func(const _Fp& __f, const _Alloc& __a) : __f_(__f, __a) {}
1409  _LIBCPP_HIDE_FROM_ABI __packaged_task_func(_Fp&& __f, const _Alloc& __a) : __f_(std::move(__f), __a) {}
1410  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __move_to(__packaged_task_base<_Rp(_ArgTypes...)>*) _NOEXCEPT;
1411  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void destroy();
1412  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void destroy_deallocate();
1413  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual _Rp operator()(_ArgTypes&&... __args);
1414};
1415
1416template <class _Fp, class _Alloc, class _Rp, class... _ArgTypes>
1417void __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__move_to(
1418    __packaged_task_base<_Rp(_ArgTypes...)>* __p) _NOEXCEPT {
1419  ::new ((void*)__p) __packaged_task_func(std::move(__f_.first()), std::move(__f_.second()));
1420}
1421
1422template <class _Fp, class _Alloc, class _Rp, class... _ArgTypes>
1423void __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy() {
1424  __f_.~__compressed_pair<_Fp, _Alloc>();
1425}
1426
1427template <class _Fp, class _Alloc, class _Rp, class... _ArgTypes>
1428void __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy_deallocate() {
1429  typedef typename __allocator_traits_rebind<_Alloc, __packaged_task_func>::type _Ap;
1430  typedef allocator_traits<_Ap> _ATraits;
1431  typedef pointer_traits<typename _ATraits::pointer> _PTraits;
1432  _Ap __a(__f_.second());
1433  __f_.~__compressed_pair<_Fp, _Alloc>();
1434  __a.deallocate(_PTraits::pointer_to(*this), 1);
1435}
1436
1437template <class _Fp, class _Alloc, class _Rp, class... _ArgTypes>
1438_Rp __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::operator()(_ArgTypes&&... __arg) {
1439  return std::__invoke(__f_.first(), std::forward<_ArgTypes>(__arg)...);
1440}
1441
1442template <class _Callable>
1443class __packaged_task_function;
1444
1445template <class _Rp, class... _ArgTypes>
1446class __packaged_task_function<_Rp(_ArgTypes...)> {
1447  typedef __packaged_task_base<_Rp(_ArgTypes...)> __base;
1448
1449  _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_CFI __base* __get_buf() { return (__base*)&__buf_; }
1450
1451  _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1452  typename aligned_storage<3 * sizeof(void*)>::type __buf_;
1453  _LIBCPP_SUPPRESS_DEPRECATED_POP
1454  __base* __f_;
1455
1456public:
1457  typedef _Rp result_type;
1458
1459  // construct/copy/destroy:
1460  _LIBCPP_HIDE_FROM_ABI __packaged_task_function() _NOEXCEPT : __f_(nullptr) {}
1461  template <class _Fp>
1462  _LIBCPP_HIDE_FROM_ABI __packaged_task_function(_Fp&& __f);
1463  template <class _Fp, class _Alloc>
1464  _LIBCPP_HIDE_FROM_ABI __packaged_task_function(allocator_arg_t, const _Alloc& __a, _Fp&& __f);
1465
1466  _LIBCPP_HIDE_FROM_ABI __packaged_task_function(__packaged_task_function&&) _NOEXCEPT;
1467  _LIBCPP_HIDE_FROM_ABI __packaged_task_function& operator=(__packaged_task_function&&) _NOEXCEPT;
1468
1469  __packaged_task_function(const __packaged_task_function&)            = delete;
1470  __packaged_task_function& operator=(const __packaged_task_function&) = delete;
1471
1472  _LIBCPP_HIDE_FROM_ABI ~__packaged_task_function();
1473
1474  _LIBCPP_HIDE_FROM_ABI void swap(__packaged_task_function&) _NOEXCEPT;
1475
1476  _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDE_FROM_ABI _Rp operator()(_ArgTypes...) const;
1477};
1478
1479template <class _Rp, class... _ArgTypes>
1480__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(__packaged_task_function&& __f) _NOEXCEPT {
1481  if (__f.__f_ == nullptr)
1482    __f_ = nullptr;
1483  else if (__f.__f_ == __f.__get_buf()) {
1484    __f.__f_->__move_to(__get_buf());
1485    __f_ = (__base*)&__buf_;
1486  } else {
1487    __f_     = __f.__f_;
1488    __f.__f_ = nullptr;
1489  }
1490}
1491
1492template <class _Rp, class... _ArgTypes>
1493template <class _Fp>
1494__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(_Fp&& __f) : __f_(nullptr) {
1495  typedef __libcpp_remove_reference_t<__decay_t<_Fp> > _FR;
1496  typedef __packaged_task_func<_FR, allocator<_FR>, _Rp(_ArgTypes...)> _FF;
1497  if (sizeof(_FF) <= sizeof(__buf_)) {
1498    ::new ((void*)&__buf_) _FF(std::forward<_Fp>(__f));
1499    __f_ = (__base*)&__buf_;
1500  } else {
1501    typedef allocator<_FF> _Ap;
1502    _Ap __a;
1503    typedef __allocator_destructor<_Ap> _Dp;
1504    unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
1505    ::new ((void*)__hold.get()) _FF(std::forward<_Fp>(__f), allocator<_FR>(__a));
1506    __f_ = __hold.release();
1507  }
1508}
1509
1510template <class _Rp, class... _ArgTypes>
1511template <class _Fp, class _Alloc>
1512__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(allocator_arg_t, const _Alloc& __a0, _Fp&& __f)
1513    : __f_(nullptr) {
1514  typedef __libcpp_remove_reference_t<__decay_t<_Fp> > _FR;
1515  typedef __packaged_task_func<_FR, _Alloc, _Rp(_ArgTypes...)> _FF;
1516  if (sizeof(_FF) <= sizeof(__buf_)) {
1517    __f_ = (__base*)&__buf_;
1518    ::new ((void*)__f_) _FF(std::forward<_Fp>(__f));
1519  } else {
1520    typedef typename __allocator_traits_rebind<_Alloc, _FF>::type _Ap;
1521    _Ap __a(__a0);
1522    typedef __allocator_destructor<_Ap> _Dp;
1523    unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
1524    ::new ((void*)std::addressof(*__hold.get())) _FF(std::forward<_Fp>(__f), _Alloc(__a));
1525    __f_ = std::addressof(*__hold.release());
1526  }
1527}
1528
1529template <class _Rp, class... _ArgTypes>
1530__packaged_task_function<_Rp(_ArgTypes...)>&
1531__packaged_task_function<_Rp(_ArgTypes...)>::operator=(__packaged_task_function&& __f) _NOEXCEPT {
1532  if (__f_ == __get_buf())
1533    __f_->destroy();
1534  else if (__f_)
1535    __f_->destroy_deallocate();
1536  __f_ = nullptr;
1537  if (__f.__f_ == nullptr)
1538    __f_ = nullptr;
1539  else if (__f.__f_ == __f.__get_buf()) {
1540    __f.__f_->__move_to(__get_buf());
1541    __f_ = __get_buf();
1542  } else {
1543    __f_     = __f.__f_;
1544    __f.__f_ = nullptr;
1545  }
1546  return *this;
1547}
1548
1549template <class _Rp, class... _ArgTypes>
1550__packaged_task_function<_Rp(_ArgTypes...)>::~__packaged_task_function() {
1551  if (__f_ == __get_buf())
1552    __f_->destroy();
1553  else if (__f_)
1554    __f_->destroy_deallocate();
1555}
1556
1557template <class _Rp, class... _ArgTypes>
1558_LIBCPP_NO_CFI void __packaged_task_function<_Rp(_ArgTypes...)>::swap(__packaged_task_function& __f) _NOEXCEPT {
1559  if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_) {
1560    _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1561    typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
1562    _LIBCPP_SUPPRESS_DEPRECATED_POP
1563    __base* __t = (__base*)&__tempbuf;
1564    __f_->__move_to(__t);
1565    __f_->destroy();
1566    __f_ = nullptr;
1567    __f.__f_->__move_to((__base*)&__buf_);
1568    __f.__f_->destroy();
1569    __f.__f_ = nullptr;
1570    __f_     = (__base*)&__buf_;
1571    __t->__move_to((__base*)&__f.__buf_);
1572    __t->destroy();
1573    __f.__f_ = (__base*)&__f.__buf_;
1574  } else if (__f_ == (__base*)&__buf_) {
1575    __f_->__move_to((__base*)&__f.__buf_);
1576    __f_->destroy();
1577    __f_     = __f.__f_;
1578    __f.__f_ = (__base*)&__f.__buf_;
1579  } else if (__f.__f_ == (__base*)&__f.__buf_) {
1580    __f.__f_->__move_to((__base*)&__buf_);
1581    __f.__f_->destroy();
1582    __f.__f_ = __f_;
1583    __f_     = (__base*)&__buf_;
1584  } else
1585    std::swap(__f_, __f.__f_);
1586}
1587
1588template <class _Rp, class... _ArgTypes>
1589inline _Rp __packaged_task_function<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __arg) const {
1590  return (*__f_)(std::forward<_ArgTypes>(__arg)...);
1591}
1592
1593template <class _Rp, class... _ArgTypes>
1594class _LIBCPP_TEMPLATE_VIS packaged_task<_Rp(_ArgTypes...)> {
1595public:
1596  typedef _Rp result_type; // extension
1597
1598private:
1599  __packaged_task_function<result_type(_ArgTypes...)> __f_;
1600  promise<result_type> __p_;
1601
1602public:
1603  // construction and destruction
1604  _LIBCPP_HIDE_FROM_ABI packaged_task() _NOEXCEPT : __p_(nullptr) {}
1605  template <class _Fp, class = __enable_if_t<!is_same<__remove_cvref_t<_Fp>, packaged_task>::value> >
1606  _LIBCPP_HIDE_FROM_ABI explicit packaged_task(_Fp&& __f) : __f_(std::forward<_Fp>(__f)) {}
1607  template <class _Fp, class _Allocator, class = __enable_if_t<!is_same<__remove_cvref_t<_Fp>, packaged_task>::value> >
1608  _LIBCPP_HIDE_FROM_ABI packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
1609      : __f_(allocator_arg_t(), __a, std::forward<_Fp>(__f)), __p_(allocator_arg_t(), __a) {}
1610  // ~packaged_task() = default;
1611
1612  // no copy
1613  packaged_task(const packaged_task&)            = delete;
1614  packaged_task& operator=(const packaged_task&) = delete;
1615
1616  // move support
1617  _LIBCPP_HIDE_FROM_ABI packaged_task(packaged_task&& __other) _NOEXCEPT
1618      : __f_(std::move(__other.__f_)),
1619        __p_(std::move(__other.__p_)) {}
1620  _LIBCPP_HIDE_FROM_ABI packaged_task& operator=(packaged_task&& __other) _NOEXCEPT {
1621    __f_ = std::move(__other.__f_);
1622    __p_ = std::move(__other.__p_);
1623    return *this;
1624  }
1625  _LIBCPP_HIDE_FROM_ABI void swap(packaged_task& __other) _NOEXCEPT {
1626    __f_.swap(__other.__f_);
1627    __p_.swap(__other.__p_);
1628  }
1629
1630  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __p_.__state_ != nullptr; }
1631
1632  // result retrieval
1633  _LIBCPP_HIDE_FROM_ABI future<result_type> get_future() { return __p_.get_future(); }
1634
1635  // execution
1636  _LIBCPP_HIDE_FROM_ABI void operator()(_ArgTypes... __args);
1637  _LIBCPP_HIDE_FROM_ABI void make_ready_at_thread_exit(_ArgTypes... __args);
1638
1639  _LIBCPP_HIDE_FROM_ABI void reset();
1640};
1641
1642template <class _Rp, class... _ArgTypes>
1643void packaged_task<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __args) {
1644  if (__p_.__state_ == nullptr)
1645    __throw_future_error(future_errc::no_state);
1646  if (__p_.__state_->__has_value())
1647    __throw_future_error(future_errc::promise_already_satisfied);
1648#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1649  try {
1650#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1651    __p_.set_value(__f_(std::forward<_ArgTypes>(__args)...));
1652#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1653  } catch (...) {
1654    __p_.set_exception(current_exception());
1655  }
1656#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1657}
1658
1659template <class _Rp, class... _ArgTypes>
1660void packaged_task<_Rp(_ArgTypes...)>::make_ready_at_thread_exit(_ArgTypes... __args) {
1661  if (__p_.__state_ == nullptr)
1662    __throw_future_error(future_errc::no_state);
1663  if (__p_.__state_->__has_value())
1664    __throw_future_error(future_errc::promise_already_satisfied);
1665#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1666  try {
1667#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1668    __p_.set_value_at_thread_exit(__f_(std::forward<_ArgTypes>(__args)...));
1669#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1670  } catch (...) {
1671    __p_.set_exception_at_thread_exit(current_exception());
1672  }
1673#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1674}
1675
1676template <class _Rp, class... _ArgTypes>
1677void packaged_task<_Rp(_ArgTypes...)>::reset() {
1678  if (!valid())
1679    __throw_future_error(future_errc::no_state);
1680  __p_ = promise<result_type>();
1681}
1682
1683template <class... _ArgTypes>
1684class _LIBCPP_TEMPLATE_VIS packaged_task<void(_ArgTypes...)> {
1685public:
1686  typedef void result_type; // extension
1687
1688private:
1689  __packaged_task_function<result_type(_ArgTypes...)> __f_;
1690  promise<result_type> __p_;
1691
1692public:
1693  // construction and destruction
1694  _LIBCPP_HIDE_FROM_ABI packaged_task() _NOEXCEPT : __p_(nullptr) {}
1695  template <class _Fp, class = __enable_if_t<!is_same<__remove_cvref_t<_Fp>, packaged_task>::value> >
1696  _LIBCPP_HIDE_FROM_ABI explicit packaged_task(_Fp&& __f) : __f_(std::forward<_Fp>(__f)) {}
1697  template <class _Fp, class _Allocator, class = __enable_if_t<!is_same<__remove_cvref_t<_Fp>, packaged_task>::value> >
1698  _LIBCPP_HIDE_FROM_ABI packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
1699      : __f_(allocator_arg_t(), __a, std::forward<_Fp>(__f)), __p_(allocator_arg_t(), __a) {}
1700  // ~packaged_task() = default;
1701
1702  // no copy
1703  packaged_task(const packaged_task&)            = delete;
1704  packaged_task& operator=(const packaged_task&) = delete;
1705
1706  // move support
1707  _LIBCPP_HIDE_FROM_ABI packaged_task(packaged_task&& __other) _NOEXCEPT
1708      : __f_(std::move(__other.__f_)),
1709        __p_(std::move(__other.__p_)) {}
1710  _LIBCPP_HIDE_FROM_ABI packaged_task& operator=(packaged_task&& __other) _NOEXCEPT {
1711    __f_ = std::move(__other.__f_);
1712    __p_ = std::move(__other.__p_);
1713    return *this;
1714  }
1715  _LIBCPP_HIDE_FROM_ABI void swap(packaged_task& __other) _NOEXCEPT {
1716    __f_.swap(__other.__f_);
1717    __p_.swap(__other.__p_);
1718  }
1719
1720  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __p_.__state_ != nullptr; }
1721
1722  // result retrieval
1723  _LIBCPP_HIDE_FROM_ABI future<result_type> get_future() { return __p_.get_future(); }
1724
1725  // execution
1726  _LIBCPP_HIDE_FROM_ABI void operator()(_ArgTypes... __args);
1727  _LIBCPP_HIDE_FROM_ABI void make_ready_at_thread_exit(_ArgTypes... __args);
1728
1729  _LIBCPP_HIDE_FROM_ABI void reset();
1730};
1731
1732#if _LIBCPP_STD_VER >= 17
1733
1734template <class _Rp, class... _Args>
1735packaged_task(_Rp (*)(_Args...)) -> packaged_task<_Rp(_Args...)>;
1736
1737template <class _Fp, class _Stripped = typename __strip_signature<decltype(&_Fp::operator())>::type>
1738packaged_task(_Fp) -> packaged_task<_Stripped>;
1739
1740#endif
1741
1742template <class... _ArgTypes>
1743void packaged_task<void(_ArgTypes...)>::operator()(_ArgTypes... __args) {
1744  if (__p_.__state_ == nullptr)
1745    __throw_future_error(future_errc::no_state);
1746  if (__p_.__state_->__has_value())
1747    __throw_future_error(future_errc::promise_already_satisfied);
1748#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1749  try {
1750#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1751    __f_(std::forward<_ArgTypes>(__args)...);
1752    __p_.set_value();
1753#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1754  } catch (...) {
1755    __p_.set_exception(current_exception());
1756  }
1757#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1758}
1759
1760template <class... _ArgTypes>
1761void packaged_task<void(_ArgTypes...)>::make_ready_at_thread_exit(_ArgTypes... __args) {
1762  if (__p_.__state_ == nullptr)
1763    __throw_future_error(future_errc::no_state);
1764  if (__p_.__state_->__has_value())
1765    __throw_future_error(future_errc::promise_already_satisfied);
1766#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1767  try {
1768#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1769    __f_(std::forward<_ArgTypes>(__args)...);
1770    __p_.set_value_at_thread_exit();
1771#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1772  } catch (...) {
1773    __p_.set_exception_at_thread_exit(current_exception());
1774  }
1775#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1776}
1777
1778template <class... _ArgTypes>
1779void packaged_task<void(_ArgTypes...)>::reset() {
1780  if (!valid())
1781    __throw_future_error(future_errc::no_state);
1782  __p_ = promise<result_type>();
1783}
1784
1785template <class _Rp, class... _ArgTypes>
1786inline _LIBCPP_HIDE_FROM_ABI void
1787swap(packaged_task<_Rp(_ArgTypes...)>& __x, packaged_task<_Rp(_ArgTypes...)>& __y) _NOEXCEPT {
1788  __x.swap(__y);
1789}
1790
1791template <class _Callable, class _Alloc>
1792struct _LIBCPP_TEMPLATE_VIS uses_allocator<packaged_task<_Callable>, _Alloc> : public true_type {};
1793
1794template <class _Rp, class _Fp>
1795_LIBCPP_HIDE_FROM_ABI future<_Rp> __make_deferred_assoc_state(_Fp&& __f) {
1796  unique_ptr<__deferred_assoc_state<_Rp, _Fp>, __release_shared_count> __h(
1797      new __deferred_assoc_state<_Rp, _Fp>(std::forward<_Fp>(__f)));
1798  return future<_Rp>(__h.get());
1799}
1800
1801template <class _Rp, class _Fp>
1802_LIBCPP_HIDE_FROM_ABI future<_Rp> __make_async_assoc_state(_Fp&& __f) {
1803  unique_ptr<__async_assoc_state<_Rp, _Fp>, __release_shared_count> __h(
1804      new __async_assoc_state<_Rp, _Fp>(std::forward<_Fp>(__f)));
1805  std::thread(&__async_assoc_state<_Rp, _Fp>::__execute, __h.get()).detach();
1806  return future<_Rp>(__h.get());
1807}
1808
1809#ifndef _LIBCPP_CXX03_LANG
1810
1811template <class _Fp, class... _Args>
1812class _LIBCPP_HIDDEN __async_func {
1813  tuple<_Fp, _Args...> __f_;
1814
1815public:
1816  typedef typename __invoke_of<_Fp, _Args...>::type _Rp;
1817
1818  _LIBCPP_HIDE_FROM_ABI explicit __async_func(_Fp&& __f, _Args&&... __args)
1819      : __f_(std::move(__f), std::move(__args)...) {}
1820
1821  _LIBCPP_HIDE_FROM_ABI __async_func(__async_func&& __f) : __f_(std::move(__f.__f_)) {}
1822
1823  _LIBCPP_HIDE_FROM_ABI _Rp operator()() {
1824    typedef typename __make_tuple_indices<1 + sizeof...(_Args), 1>::type _Index;
1825    return __execute(_Index());
1826  }
1827
1828private:
1829  template <size_t... _Indices>
1830  _LIBCPP_HIDE_FROM_ABI _Rp __execute(__tuple_indices<_Indices...>) {
1831    return std::__invoke(std::move(std::get<0>(__f_)), std::move(std::get<_Indices>(__f_))...);
1832  }
1833};
1834
1835inline _LIBCPP_HIDE_FROM_ABI bool __does_policy_contain(launch __policy, launch __value) {
1836  return (int(__policy) & int(__value)) != 0;
1837}
1838
1839template <class _Fp, class... _Args>
1840_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
1841    future<typename __invoke_of<__decay_t<_Fp>, __decay_t<_Args>...>::type>
1842    async(launch __policy, _Fp&& __f, _Args&&... __args) {
1843  typedef __async_func<__decay_t<_Fp>, __decay_t<_Args>...> _BF;
1844  typedef typename _BF::_Rp _Rp;
1845
1846#  ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1847  try {
1848#  endif
1849    if (__does_policy_contain(__policy, launch::async))
1850      return std::__make_async_assoc_state<_Rp>(
1851          _BF(_LIBCPP_AUTO_CAST(std::forward<_Fp>(__f)), _LIBCPP_AUTO_CAST(std::forward<_Args>(__args))...));
1852#  ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1853  } catch (...) {
1854    if (__policy == launch::async)
1855      throw;
1856  }
1857#  endif
1858
1859  if (__does_policy_contain(__policy, launch::deferred))
1860    return std::__make_deferred_assoc_state<_Rp>(
1861        _BF(_LIBCPP_AUTO_CAST(std::forward<_Fp>(__f)), _LIBCPP_AUTO_CAST(std::forward<_Args>(__args))...));
1862  return future<_Rp>{};
1863}
1864
1865template <class _Fp, class... _Args>
1866_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_HIDE_FROM_ABI
1867    future<typename __invoke_of<__decay_t<_Fp>, __decay_t<_Args>...>::type>
1868    async(_Fp&& __f, _Args&&... __args) {
1869  return std::async(launch::any, std::forward<_Fp>(__f), std::forward<_Args>(__args)...);
1870}
1871
1872#endif // C++03
1873
1874// shared_future
1875
1876template <class _Rp>
1877class _LIBCPP_TEMPLATE_VIS shared_future {
1878  __assoc_state<_Rp>* __state_;
1879
1880public:
1881  _LIBCPP_HIDE_FROM_ABI shared_future() _NOEXCEPT : __state_(nullptr) {}
1882  _LIBCPP_HIDE_FROM_ABI shared_future(const shared_future& __rhs) _NOEXCEPT : __state_(__rhs.__state_) {
1883    if (__state_)
1884      __state_->__add_shared();
1885  }
1886  _LIBCPP_HIDE_FROM_ABI shared_future(future<_Rp>&& __f) _NOEXCEPT : __state_(__f.__state_) { __f.__state_ = nullptr; }
1887  _LIBCPP_HIDE_FROM_ABI shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) {
1888    __rhs.__state_ = nullptr;
1889  }
1890  _LIBCPP_HIDE_FROM_ABI ~shared_future();
1891  _LIBCPP_HIDE_FROM_ABI shared_future& operator=(const shared_future& __rhs) _NOEXCEPT;
1892  _LIBCPP_HIDE_FROM_ABI shared_future& operator=(shared_future&& __rhs) _NOEXCEPT {
1893    shared_future(std::move(__rhs)).swap(*this);
1894    return *this;
1895  }
1896
1897  // retrieving the value
1898  _LIBCPP_HIDE_FROM_ABI const _Rp& get() const { return __state_->copy(); }
1899
1900  _LIBCPP_HIDE_FROM_ABI void swap(shared_future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1901
1902  // functions to check state
1903  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
1904
1905  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
1906  template <class _Rep, class _Period>
1907  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
1908    return __state_->wait_for(__rel_time);
1909  }
1910  template <class _Clock, class _Duration>
1911  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
1912    return __state_->wait_until(__abs_time);
1913  }
1914};
1915
1916template <class _Rp>
1917shared_future<_Rp>::~shared_future() {
1918  if (__state_)
1919    __state_->__release_shared();
1920}
1921
1922template <class _Rp>
1923shared_future<_Rp>& shared_future<_Rp>::operator=(const shared_future& __rhs) _NOEXCEPT {
1924  if (__rhs.__state_)
1925    __rhs.__state_->__add_shared();
1926  if (__state_)
1927    __state_->__release_shared();
1928  __state_ = __rhs.__state_;
1929  return *this;
1930}
1931
1932template <class _Rp>
1933class _LIBCPP_TEMPLATE_VIS shared_future<_Rp&> {
1934  __assoc_state<_Rp&>* __state_;
1935
1936public:
1937  _LIBCPP_HIDE_FROM_ABI shared_future() _NOEXCEPT : __state_(nullptr) {}
1938  _LIBCPP_HIDE_FROM_ABI shared_future(const shared_future& __rhs) : __state_(__rhs.__state_) {
1939    if (__state_)
1940      __state_->__add_shared();
1941  }
1942  _LIBCPP_HIDE_FROM_ABI shared_future(future<_Rp&>&& __f) _NOEXCEPT : __state_(__f.__state_) { __f.__state_ = nullptr; }
1943  _LIBCPP_HIDE_FROM_ABI shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) {
1944    __rhs.__state_ = nullptr;
1945  }
1946  _LIBCPP_HIDE_FROM_ABI ~shared_future();
1947  _LIBCPP_HIDE_FROM_ABI shared_future& operator=(const shared_future& __rhs);
1948  _LIBCPP_HIDE_FROM_ABI shared_future& operator=(shared_future&& __rhs) _NOEXCEPT {
1949    shared_future(std::move(__rhs)).swap(*this);
1950    return *this;
1951  }
1952
1953  // retrieving the value
1954  _LIBCPP_HIDE_FROM_ABI _Rp& get() const { return __state_->copy(); }
1955
1956  _LIBCPP_HIDE_FROM_ABI void swap(shared_future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1957
1958  // functions to check state
1959  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
1960
1961  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
1962  template <class _Rep, class _Period>
1963  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
1964    return __state_->wait_for(__rel_time);
1965  }
1966  template <class _Clock, class _Duration>
1967  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
1968    return __state_->wait_until(__abs_time);
1969  }
1970};
1971
1972template <class _Rp>
1973shared_future<_Rp&>::~shared_future() {
1974  if (__state_)
1975    __state_->__release_shared();
1976}
1977
1978template <class _Rp>
1979shared_future<_Rp&>& shared_future<_Rp&>::operator=(const shared_future& __rhs) {
1980  if (__rhs.__state_)
1981    __rhs.__state_->__add_shared();
1982  if (__state_)
1983    __state_->__release_shared();
1984  __state_ = __rhs.__state_;
1985  return *this;
1986}
1987
1988template <>
1989class _LIBCPP_EXPORTED_FROM_ABI shared_future<void> {
1990  __assoc_sub_state* __state_;
1991
1992public:
1993  _LIBCPP_HIDE_FROM_ABI shared_future() _NOEXCEPT : __state_(nullptr) {}
1994  _LIBCPP_HIDE_FROM_ABI shared_future(const shared_future& __rhs) : __state_(__rhs.__state_) {
1995    if (__state_)
1996      __state_->__add_shared();
1997  }
1998  _LIBCPP_HIDE_FROM_ABI shared_future(future<void>&& __f) _NOEXCEPT : __state_(__f.__state_) { __f.__state_ = nullptr; }
1999  _LIBCPP_HIDE_FROM_ABI shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) {
2000    __rhs.__state_ = nullptr;
2001  }
2002  ~shared_future();
2003  shared_future& operator=(const shared_future& __rhs);
2004  _LIBCPP_HIDE_FROM_ABI shared_future& operator=(shared_future&& __rhs) _NOEXCEPT {
2005    shared_future(std::move(__rhs)).swap(*this);
2006    return *this;
2007  }
2008
2009  // retrieving the value
2010  _LIBCPP_HIDE_FROM_ABI void get() const { __state_->copy(); }
2011
2012  _LIBCPP_HIDE_FROM_ABI void swap(shared_future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
2013
2014  // functions to check state
2015  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
2016
2017  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
2018  template <class _Rep, class _Period>
2019  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
2020    return __state_->wait_for(__rel_time);
2021  }
2022  template <class _Clock, class _Duration>
2023  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
2024    return __state_->wait_until(__abs_time);
2025  }
2026};
2027
2028template <class _Rp>
2029inline _LIBCPP_HIDE_FROM_ABI void swap(shared_future<_Rp>& __x, shared_future<_Rp>& __y) _NOEXCEPT {
2030  __x.swap(__y);
2031}
2032
2033template <class _Rp>
2034inline shared_future<_Rp> future<_Rp>::share() _NOEXCEPT {
2035  return shared_future<_Rp>(std::move(*this));
2036}
2037
2038template <class _Rp>
2039inline shared_future<_Rp&> future<_Rp&>::share() _NOEXCEPT {
2040  return shared_future<_Rp&>(std::move(*this));
2041}
2042
2043inline shared_future<void> future<void>::share() _NOEXCEPT { return shared_future<void>(std::move(*this)); }
2044
2045_LIBCPP_END_NAMESPACE_STD
2046
2047#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 17
2048#  include <chrono>
2049#endif
2050
2051#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
2052#  include <atomic>
2053#  include <cstdlib>
2054#  include <exception>
2055#  include <iosfwd>
2056#  include <system_error>
2057#endif
2058
2059#endif // _LIBCPP_FUTURE
2060