29 #ifndef _GLIBCXX_FUTURE
30 #define _GLIBCXX_FUTURE 1
32 #pragma GCC system_header
34 #if __cplusplus < 201103L
47 #include <bits/shared_ptr.h>
49 #include <bits/uses_allocator.h>
53 namespace std _GLIBCXX_VISIBILITY(default)
55 _GLIBCXX_BEGIN_NAMESPACE_VERSION
68 future_already_retrieved = 1,
69 promise_already_satisfied,
88 inline error_condition
107 what()
const noexcept;
110 code()
const noexcept {
return _M_code; }
115 :
logic_error(
"std::future_error: " + __ec.message()), _M_code(__ec)
118 friend void __throw_future_error(
int);
124 template<
typename _Res>
127 template<
typename _Res>
130 template<
typename _Signature>
133 template<
typename _Res>
145 return static_cast<launch>(
146 static_cast<int>(__x) &
static_cast<int>(__y));
151 return static_cast<launch>(
152 static_cast<int>(__x) |
static_cast<int>(__y));
157 return static_cast<launch>(
158 static_cast<int>(__x) ^
static_cast<int>(__y));
162 {
return static_cast<launch>(~static_cast<int>(__x)); }
165 {
return __x = __x & __y; }
168 {
return __x = __x | __y; }
171 {
return __x = __x ^ __y; }
183 template<
typename _Fn,
typename... _Args>
184 using __async_result_of =
typename __invoke_result<
185 typename decay<_Fn>::type,
typename decay<_Args>::type...>::type;
187 template<
typename _Fn,
typename... _Args>
188 future<__async_result_of<_Fn, _Args...>>
189 async(
launch __policy, _Fn&& __fn, _Args&&... __args);
191 template<
typename _Fn,
typename... _Args>
192 future<__async_result_of<_Fn, _Args...>>
193 async(_Fn&& __fn, _Args&&... __args);
195 #if defined(_GLIBCXX_HAS_GTHREADS)
209 virtual void _M_destroy() = 0;
213 void operator()(
_Result_base* __fr)
const { __fr->_M_destroy(); }
222 template<
typename _Res>
226 template<
typename _Res>
230 __gnu_cxx::__aligned_buffer<_Res> _M_storage;
234 typedef _Res result_type;
236 _Result() noexcept : _M_initialized() { }
246 _M_value() noexcept {
return *_M_storage._M_ptr(); }
249 _M_set(
const _Res& __res)
251 ::new (_M_storage._M_addr()) _Res(__res);
252 _M_initialized =
true;
258 ::new (_M_storage._M_addr()) _Res(
std::move(__res));
259 _M_initialized =
true;
263 void _M_destroy() {
delete this; }
267 template<
typename _Res,
typename _Alloc>
270 using __allocator_type = __alloc_rebind<_Alloc, _Result_alloc>;
279 __allocator_type __a(*
this);
286 template<
typename _Res,
typename _Allocator>
288 _S_allocate_result(
const _Allocator& __a)
291 typename __result_type::__allocator_type __a2(__a);
293 __result_type* __p = ::new((
void*)__guard.get()) __result_type{__a};
295 return _Ptr<__result_type>(__p);
299 template<
typename _Res,
typename _Tp>
300 static _Ptr<_Result<_Res>>
303 return _Ptr<_Result<_Res>>(
new _Result<_Res>);
311 typedef _Ptr<_Result_base> _Ptr_type;
313 enum _Status :
unsigned {
319 __atomic_futex_unsigned<> _M_status;
320 atomic_flag _M_retrieved = ATOMIC_FLAG_INIT;
324 _State_baseV2() noexcept : _M_result(), _M_status(_Status::__not_ready)
326 _State_baseV2(
const _State_baseV2&) =
delete;
327 _State_baseV2& operator=(
const _State_baseV2&) =
delete;
328 virtual ~_State_baseV2() =
default;
337 _M_status._M_load_when_equal(_Status::__ready, memory_order_acquire);
341 template<
typename _Rep,
typename _Period>
343 wait_for(
const chrono::duration<_Rep, _Period>& __rel)
347 if (_M_status._M_load(memory_order_acquire) == _Status::__ready)
348 return future_status::ready;
349 if (_M_is_deferred_future())
350 return future_status::deferred;
351 if (_M_status._M_load_when_equal_for(_Status::__ready,
352 memory_order_acquire, __rel))
365 return future_status::ready;
367 return future_status::timeout;
370 template<
typename _Clock,
typename _Duration>
372 wait_until(
const chrono::time_point<_Clock, _Duration>& __abs)
376 if (_M_status._M_load(memory_order_acquire) == _Status::__ready)
377 return future_status::ready;
378 if (_M_is_deferred_future())
379 return future_status::deferred;
380 if (_M_status._M_load_when_equal_until(_Status::__ready,
381 memory_order_acquire, __abs))
388 return future_status::ready;
390 return future_status::timeout;
396 _M_set_result(
function<_Ptr_type()> __res,
bool __ignore_failure =
false)
398 bool __did_set =
false;
401 call_once(_M_once, &_State_baseV2::_M_do_set,
this,
405 _M_status._M_store_notify_all(_Status::__ready,
406 memory_order_release);
407 else if (!__ignore_failure)
408 __throw_future_error(
int(future_errc::promise_already_satisfied));
415 _M_set_delayed_result(
function<_Ptr_type()> __res,
416 weak_ptr<_State_baseV2> __self)
418 bool __did_set =
false;
419 unique_ptr<_Make_ready> __mr{
new _Make_ready};
422 call_once(_M_once, &_State_baseV2::_M_do_set,
this,
425 __throw_future_error(
int(future_errc::promise_already_satisfied));
426 __mr->_M_shared_state =
std::move(__self);
433 _M_break_promise(_Ptr_type __res)
435 if (
static_cast<bool>(__res))
443 _M_result.swap(__res);
445 _M_status._M_store_notify_all(_Status::__ready,
446 memory_order_release);
452 _M_set_retrieved_flag()
454 if (_M_retrieved.test_and_set())
455 __throw_future_error(
int(future_errc::future_already_retrieved));
458 template<
typename _Res,
typename _Arg>
462 template<
typename _Res,
typename _Arg>
463 struct _Setter<_Res, _Arg&>
467 static_assert(is_same<_Res, _Arg&>::value
468 || is_same<const _Res, _Arg>::value,
469 "Invalid specialisation");
472 typename promise<_Res>::_Ptr_type operator()()
const
474 _M_promise->_M_storage->_M_set(*_M_arg);
475 return std::move(_M_promise->_M_storage);
477 promise<_Res>* _M_promise;
482 template<
typename _Res>
483 struct _Setter<_Res, _Res&&>
486 typename promise<_Res>::_Ptr_type operator()()
const
488 _M_promise->_M_storage->_M_set(
std::move(*_M_arg));
489 return std::move(_M_promise->_M_storage);
491 promise<_Res>* _M_promise;
496 template<
typename _Res>
497 struct _Setter<_Res, void>
499 static_assert(is_void<_Res>::value,
"Only used for promise<void>");
501 typename promise<_Res>::_Ptr_type operator()()
const
502 {
return std::move(_M_promise->_M_storage); }
504 promise<_Res>* _M_promise;
507 struct __exception_ptr_tag { };
510 template<
typename _Res>
511 struct _Setter<_Res, __exception_ptr_tag>
514 typename promise<_Res>::_Ptr_type operator()()
const
516 _M_promise->_M_storage->_M_error = *_M_ex;
517 return std::move(_M_promise->_M_storage);
520 promise<_Res>* _M_promise;
521 exception_ptr* _M_ex;
524 template<
typename _Res,
typename _Arg>
525 static _Setter<_Res, _Arg&&>
526 __setter(promise<_Res>* __prom, _Arg&& __arg)
528 _S_check(__prom->_M_future);
532 template<
typename _Res>
533 static _Setter<_Res, __exception_ptr_tag>
534 __setter(exception_ptr& __ex, promise<_Res>* __prom)
536 _S_check(__prom->_M_future);
537 return _Setter<_Res, __exception_ptr_tag>{ __prom, &__ex };
540 template<
typename _Res>
541 static _Setter<_Res, void>
542 __setter(promise<_Res>* __prom)
544 _S_check(__prom->_M_future);
545 return _Setter<_Res, void>{ __prom };
548 template<
typename _Tp>
550 _S_check(
const shared_ptr<_Tp>& __p)
552 if (!
static_cast<bool>(__p))
553 __throw_future_error((
int)future_errc::no_state);
559 _M_do_set(
function<_Ptr_type()>* __f,
bool* __did_set)
561 _Ptr_type __res = (*__f)();
566 _M_result.swap(__res);
570 virtual void _M_complete_async() { }
573 virtual bool _M_is_deferred_future()
const {
return false; }
575 struct _Make_ready final : __at_thread_exit_elt
577 weak_ptr<_State_baseV2> _M_shared_state;
578 static void _S_run(
void*);
583 #ifdef _GLIBCXX_ASYNC_ABI_COMPAT
585 class _Async_state_common;
587 using _State_base = _State_baseV2;
588 class _Async_state_commonV2;
591 template<
typename _BoundFn,
592 typename _Res = decltype(std::declval<_BoundFn&>()())>
593 class _Deferred_state;
595 template<
typename _BoundFn,
596 typename _Res = decltype(std::declval<_BoundFn&>()())>
597 class _Async_state_impl;
599 template<
typename _Signature>
600 class _Task_state_base;
602 template<
typename _Fn,
typename _Alloc,
typename _Signature>
605 template<
typename _BoundFn>
607 _S_make_deferred_state(_BoundFn&& __fn);
609 template<
typename _BoundFn>
611 _S_make_async_state(_BoundFn&& __fn);
613 template<
typename _Res_ptr,
typename _Fn,
614 typename _Res =
typename _Res_ptr::element_type::result_type>
617 template<
typename _Res_ptr,
typename _BoundFn>
618 static _Task_setter<_Res_ptr, _BoundFn>
619 _S_task_setter(_Res_ptr& __ptr, _BoundFn& __call)
626 template<
typename _Res>
629 typedef _Res& result_type;
631 _Result() noexcept : _M_value_ptr() { }
634 _M_set(_Res& __res) noexcept
637 _Res& _M_get() noexcept {
return *_M_value_ptr; }
642 void _M_destroy() {
delete this; }
649 typedef void result_type;
652 void _M_destroy() {
delete this; }
655 #ifndef _GLIBCXX_ASYNC_ABI_COMPAT
658 template<
typename _Res,
typename _Arg>
664 template<
typename _Res_ptr,
typename _Fn,
typename _Res>
670 template<
typename _Res>
686 valid()
const noexcept {
return static_cast<bool>(_M_state); }
691 _State_base::_S_check(_M_state);
695 template<
typename _Rep,
typename _Period>
699 _State_base::_S_check(_M_state);
700 return _M_state->wait_for(__rel);
703 template<
typename _Clock,
typename _Duration>
707 _State_base::_S_check(_M_state);
708 return _M_state->wait_until(__abs);
716 _State_base::_S_check(_M_state);
718 if (!(__res._M_error == 0))
725 _M_state.
swap(__that._M_state);
730 __basic_future(
const __state_type& __state) : _M_state(__state)
732 _State_base::_S_check(_M_state);
733 _M_state->_M_set_retrieved_flag();
738 __basic_future(
const shared_future<_Res>&) noexcept;
742 __basic_future(shared_future<_Res>&&) noexcept;
746 __basic_future(future<_Res>&&) noexcept;
748 constexpr __basic_future() noexcept : _M_state() { }
752 explicit _Reset(__basic_future& __fut) noexcept : _M_fut(__fut) { }
753 ~_Reset() { _M_fut._M_state.reset(); }
754 __basic_future& _M_fut;
760 template<
typename _Res>
761 class future :
public __basic_future<_Res>
763 friend class promise<_Res>;
764 template<
typename>
friend class packaged_task;
765 template<
typename _Fn,
typename... _Args>
766 friend future<__async_result_of<_Fn, _Args...>>
769 typedef __basic_future<_Res> _Base_type;
770 typedef typename _Base_type::__state_type __state_type;
773 future(
const __state_type& __state) : _Base_type(__state) { }
776 constexpr future() noexcept : _Base_type() { }
795 typename _Base_type::_Reset __reset(*
this);
796 return std::move(this->_M_get_result()._M_value());
803 template<typename _Res>
807 template<
typename>
friend class packaged_task;
808 template<
typename _Fn,
typename... _Args>
809 friend future<__async_result_of<_Fn, _Args...>>
838 typename _Base_type::_Reset __reset(*
this);
839 return this->_M_get_result()._M_get();
850 template<
typename>
friend class packaged_task;
851 template<
typename _Fn,
typename... _Args>
852 friend future<__async_result_of<_Fn, _Args...>>
881 typename _Base_type::_Reset __reset(*
this);
882 this->_M_get_result();
890 template<typename _Res>
917 shared_future& operator=(shared_future&& __sf) noexcept
919 shared_future(
std::move(__sf))._M_swap(*
this);
925 get()
const {
return this->_M_get_result()._M_value(); }
929 template<
typename _Res>
956 shared_future& operator=(shared_future&& __sf) noexcept
958 shared_future(
std::move(__sf))._M_swap(*
this);
964 get()
const {
return this->_M_get_result()._M_get(); }
995 shared_future& operator=(shared_future&& __sf) noexcept
997 shared_future(
std::move(__sf))._M_swap(*
this);
1003 get()
const { this->_M_get_result(); }
1007 template<
typename _Res>
1008 inline __basic_future<_Res>::
1009 __basic_future(
const shared_future<_Res>& __sf) noexcept
1010 : _M_state(__sf._M_state)
1013 template<
typename _Res>
1014 inline __basic_future<_Res>::
1015 __basic_future(shared_future<_Res>&& __sf) noexcept
1019 template<
typename _Res>
1020 inline __basic_future<_Res>::
1021 __basic_future(future<_Res>&& __uf) noexcept
1027 template<
typename _Res>
1028 inline shared_future<_Res>
1029 future<_Res>::share() noexcept
1030 {
return shared_future<_Res>(
std::move(*
this)); }
1032 template<
typename _Res>
1033 inline shared_future<_Res&>
1034 future<_Res&>::share() noexcept
1035 {
return shared_future<_Res&>(
std::move(*
this)); }
1037 inline shared_future<void>
1038 future<void>::share() noexcept
1039 {
return shared_future<void>(
std::move(*
this)); }
1042 template<
typename _Res>
1045 typedef __future_base::_State_base _State;
1046 typedef __future_base::_Result<_Res> _Res_type;
1047 typedef __future_base::_Ptr<_Res_type> _Ptr_type;
1048 template<
typename,
typename>
friend class _State::_Setter;
1051 shared_ptr<_State> _M_future;
1052 _Ptr_type _M_storage;
1056 : _M_future(
std::make_shared<_State>()),
1057 _M_storage(new _Res_type())
1060 promise(promise&& __rhs) noexcept
1061 : _M_future(
std::move(__rhs._M_future)),
1065 template<
typename _Allocator>
1066 promise(allocator_arg_t,
const _Allocator& __a)
1067 : _M_future(
std::allocate_shared<_State>(__a)),
1068 _M_storage(__future_base::_S_allocate_result<_Res>(__a))
1071 template<
typename _Allocator>
1072 promise(allocator_arg_t,
const _Allocator&, promise&& __rhs)
1073 : _M_future(
std::
move(__rhs._M_future)),
1074 _M_storage(
std::
move(__rhs._M_storage))
1077 promise(
const promise&) =
delete;
1081 if (
static_cast<bool>(_M_future) && !_M_future.unique())
1082 _M_future->_M_break_promise(
std::move(_M_storage));
1087 operator=(promise&& __rhs) noexcept
1093 promise& operator=(
const promise&) =
delete;
1096 swap(promise& __rhs) noexcept
1098 _M_future.swap(__rhs._M_future);
1099 _M_storage.swap(__rhs._M_storage);
1105 {
return future<_Res>(_M_future); }
1109 set_value(
const _Res& __r)
1110 { _M_future->_M_set_result(_State::__setter(
this, __r)); }
1113 set_value(_Res&& __r)
1114 { _M_future->_M_set_result(_State::__setter(
this,
std::move(__r))); }
1117 set_exception(exception_ptr __p)
1118 { _M_future->_M_set_result(_State::__setter(__p,
this)); }
1121 set_value_at_thread_exit(
const _Res& __r)
1123 _M_future->_M_set_delayed_result(_State::__setter(
this, __r),
1128 set_value_at_thread_exit(_Res&& __r)
1130 _M_future->_M_set_delayed_result(
1131 _State::__setter(
this,
std::move(__r)), _M_future);
1135 set_exception_at_thread_exit(exception_ptr __p)
1137 _M_future->_M_set_delayed_result(_State::__setter(__p,
this),
1142 template<
typename _Res>
1144 swap(promise<_Res>& __x, promise<_Res>& __y) noexcept
1147 template<
typename _Res,
typename _Alloc>
1148 struct uses_allocator<promise<_Res>, _Alloc>
1153 template<
typename _Res>
1156 typedef __future_base::_State_base _State;
1159 template<
typename,
typename>
friend class _State::_Setter;
1167 : _M_future(std::make_shared<_State>()),
1172 : _M_future(
std::move(__rhs._M_future)),
1176 template<
typename _Allocator>
1178 : _M_future(std::allocate_shared<_State>(__a)),
1179 _M_storage(__future_base::_S_allocate_result<_Res&>(__a))
1182 template<
typename _Allocator>
1184 : _M_future(
std::move(__rhs._M_future)),
1192 if (
static_cast<bool>(_M_future) && !_M_future.unique())
1193 _M_future->_M_break_promise(
std::move(_M_storage));
1198 operator=(
promise&& __rhs) noexcept
1209 _M_future.
swap(__rhs._M_future);
1210 _M_storage.
swap(__rhs._M_storage);
1220 set_value(_Res& __r)
1221 { _M_future->_M_set_result(_State::__setter(
this, __r)); }
1225 { _M_future->_M_set_result(_State::__setter(__p,
this)); }
1228 set_value_at_thread_exit(_Res& __r)
1230 _M_future->_M_set_delayed_result(_State::__setter(
this, __r),
1237 _M_future->_M_set_delayed_result(_State::__setter(__p,
this),
1246 typedef __future_base::_State_base _State;
1249 template<
typename,
typename>
friend class _State::_Setter;
1257 : _M_future(std::make_shared<_State>()),
1262 : _M_future(
std::move(__rhs._M_future)),
1266 template<
typename _Allocator>
1268 : _M_future(std::allocate_shared<_State>(__a)),
1269 _M_storage(__future_base::_S_allocate_result<void>(__a))
1274 template<
typename _Allocator>
1276 : _M_future(
std::move(__rhs._M_future)),
1284 if (
static_cast<bool>(_M_future) && !_M_future.unique())
1285 _M_future->_M_break_promise(
std::move(_M_storage));
1290 operator=(
promise&& __rhs) noexcept
1301 _M_future.
swap(__rhs._M_future);
1302 _M_storage.
swap(__rhs._M_storage);
1313 { _M_future->_M_set_result(_State::__setter(
this)); }
1317 { _M_future->_M_set_result(_State::__setter(__p,
this)); }
1320 set_value_at_thread_exit()
1321 { _M_future->_M_set_delayed_result(_State::__setter(
this), _M_future); }
1326 _M_future->_M_set_delayed_result(_State::__setter(__p,
this),
1331 template<
typename _Ptr_type,
typename _Fn,
typename _Res>
1332 struct __future_base::_Task_setter
1335 _Ptr_type operator()()
const
1339 (*_M_result)->_M_set((*_M_fn)());
1343 __throw_exception_again;
1351 _Ptr_type* _M_result;
1355 template<
typename _Ptr_type,
typename _Fn>
1356 struct __future_base::_Task_setter<_Ptr_type, _Fn, void>
1358 _Ptr_type operator()()
const
1366 __throw_exception_again;
1374 _Ptr_type* _M_result;
1379 template<
typename _Res,
typename... _Args>
1380 struct __future_base::_Task_state_base<_Res(_Args...)>
1381 : __future_base::_State_base
1383 typedef _Res _Res_type;
1385 template<
typename _Alloc>
1386 _Task_state_base(
const _Alloc& __a)
1387 : _M_result(_S_allocate_result<_Res>(__a))
1392 _M_run(_Args&&... __args) = 0;
1396 _M_run_delayed(_Args&&... __args, weak_ptr<_State_base>) = 0;
1398 virtual shared_ptr<_Task_state_base>
1401 typedef __future_base::_Ptr<_Result<_Res>> _Ptr_type;
1402 _Ptr_type _M_result;
1406 template<
typename _Fn,
typename _Alloc,
typename _Res,
typename... _Args>
1407 struct __future_base::_Task_state<_Fn, _Alloc, _Res(_Args...)> final
1408 : __future_base::_Task_state_base<_Res(_Args...)>
1410 template<
typename _Fn2>
1411 _Task_state(_Fn2&& __fn,
const _Alloc& __a)
1412 : _Task_state_base<_Res(_Args...)>(__a),
1418 _M_run(_Args&&... __args)
1420 auto __boundfn = [&] () -> _Res {
1421 return std::__invoke_r<_Res>(_M_impl._M_fn,
1422 std::forward<_Args>(__args)...);
1424 this->_M_set_result(_S_task_setter(this->_M_result, __boundfn));
1428 _M_run_delayed(_Args&&... __args, weak_ptr<_State_base> __self)
1430 auto __boundfn = [&] () -> _Res {
1431 return std::__invoke_r<_Res>(_M_impl._M_fn,
1432 std::forward<_Args>(__args)...);
1434 this->_M_set_delayed_result(_S_task_setter(this->_M_result, __boundfn),
1438 virtual shared_ptr<_Task_state_base<_Res(_Args...)>>
1441 struct _Impl : _Alloc
1443 template<
typename _Fn2>
1444 _Impl(_Fn2&& __fn,
const _Alloc& __a)
1445 : _Alloc(__a), _M_fn(
std::
forward<_Fn2>(__fn)) { }
1450 template<
typename _Signature,
typename _Fn,
1452 static shared_ptr<__future_base::_Task_state_base<_Signature>>
1453 __create_task_state(_Fn&& __fn,
const _Alloc& __a = _Alloc())
1455 typedef typename decay<_Fn>::type _Fn2;
1456 typedef __future_base::_Task_state<_Fn2, _Alloc, _Signature> _State;
1457 return std::allocate_shared<_State>(__a, std::forward<_Fn>(__fn), __a);
1460 template<
typename _Fn,
typename _Alloc,
typename _Res,
typename... _Args>
1461 shared_ptr<__future_base::_Task_state_base<_Res(_Args...)>>
1462 __future_base::_Task_state<_Fn, _Alloc, _Res(_Args...)>::_M_reset()
1464 return __create_task_state<_Res(_Args...)>(
std::move(_M_impl._M_fn),
1465 static_cast<_Alloc&
>(_M_impl));
1469 template<
typename _Res,
typename... _ArgTypes>
1470 class packaged_task<_Res(_ArgTypes...)>
1472 typedef __future_base::_Task_state_base<_Res(_ArgTypes...)> _State_type;
1477 template<
typename _Fn,
typename _Fn2 = __remove_cvref_t<_Fn>>
1483 packaged_task() noexcept { }
1485 template<
typename _Fn,
typename = __not_same<_Fn>>
1487 packaged_task(_Fn&& __fn)
1489 __create_task_state<_Res(_ArgTypes...)>(std::forward<_Fn>(__fn)))
1492 #if __cplusplus < 201703L
1497 template<
typename _Fn,
typename _Alloc,
typename = __not_same<_Fn>>
1499 : _M_state(__create_task_state<_Res(_ArgTypes...)>(
1500 std::forward<_Fn>(__fn), __a))
1505 template<
typename _Allocator>
1509 template<
typename _Allocator>
1511 const packaged_task&) =
delete;
1513 template<
typename _Allocator>
1515 packaged_task&& __other) noexcept
1516 { this->swap(__other); }
1521 if (
static_cast<bool>(_M_state) && !_M_state.unique())
1522 _M_state->_M_break_promise(
std::move(_M_state->_M_result));
1526 packaged_task(
const packaged_task&) =
delete;
1527 packaged_task& operator=(
const packaged_task&) =
delete;
1530 packaged_task(packaged_task&& __other) noexcept
1531 { this->swap(__other); }
1533 packaged_task& operator=(packaged_task&& __other) noexcept
1535 packaged_task(
std::move(__other)).swap(*
this);
1540 swap(packaged_task& __other) noexcept
1541 { _M_state.
swap(__other._M_state); }
1544 valid()
const noexcept
1545 {
return static_cast<bool>(_M_state); }
1554 operator()(_ArgTypes... __args)
1556 __future_base::_State_base::_S_check(_M_state);
1557 _M_state->_M_run(std::forward<_ArgTypes>(__args)...);
1561 make_ready_at_thread_exit(_ArgTypes... __args)
1563 __future_base::_State_base::_S_check(_M_state);
1564 _M_state->_M_run_delayed(std::forward<_ArgTypes>(__args)..., _M_state);
1570 __future_base::_State_base::_S_check(_M_state);
1571 packaged_task __tmp;
1572 __tmp._M_state = _M_state;
1573 _M_state = _M_state->_M_reset();
1578 template<
typename _Res,
typename... _ArgTypes>
1580 swap(packaged_task<_Res(_ArgTypes...)>& __x,
1581 packaged_task<_Res(_ArgTypes...)>& __y) noexcept
1584 #if __cplusplus < 201703L
1587 template<
typename _Res,
typename _Alloc>
1588 struct uses_allocator<packaged_task<_Res>, _Alloc>
1594 template<
typename _BoundFn,
typename _Res>
1595 class __future_base::_Deferred_state final
1596 :
public __future_base::_State_base
1600 _Deferred_state(_BoundFn&& __fn)
1601 : _M_result(new _Result<_Res>()), _M_fn(
std::
move(__fn))
1605 typedef __future_base::_Ptr<_Result<_Res>> _Ptr_type;
1606 _Ptr_type _M_result;
1619 _M_set_result(_S_task_setter(_M_result, _M_fn),
true);
1624 virtual bool _M_is_deferred_future()
const {
return true; }
1628 class __future_base::_Async_state_commonV2
1629 :
public __future_base::_State_base
1632 ~_Async_state_commonV2() =
default;
1649 virtual void _M_complete_async() { _M_join(); }
1651 void _M_join() {
std::call_once(_M_once, &thread::join, &_M_thread); }
1659 template<
typename _BoundFn,
typename _Res>
1660 class __future_base::_Async_state_impl final
1661 :
public __future_base::_Async_state_commonV2
1665 _Async_state_impl(_BoundFn&& __fn)
1666 : _M_result(new _Result<_Res>()), _M_fn(
std::
move(__fn))
1671 _M_set_result(_S_task_setter(_M_result, _M_fn));
1676 if (
static_cast<bool>(_M_result))
1677 this->_M_break_promise(
std::move(_M_result));
1678 __throw_exception_again;
1686 ~_Async_state_impl() {
if (_M_thread.joinable()) _M_thread.join(); }
1689 typedef __future_base::_Ptr<_Result<_Res>> _Ptr_type;
1690 _Ptr_type _M_result;
1694 template<
typename _BoundFn>
1696 __future_base::_S_make_deferred_state(_BoundFn&& __fn)
1698 typedef typename remove_reference<_BoundFn>::type __fn_type;
1699 typedef _Deferred_state<__fn_type> __state_type;
1700 return std::make_shared<__state_type>(
std::move(__fn));
1703 template<
typename _BoundFn>
1705 __future_base::_S_make_async_state(_BoundFn&& __fn)
1707 typedef typename remove_reference<_BoundFn>::type __fn_type;
1708 typedef _Async_state_impl<__fn_type> __state_type;
1709 return std::make_shared<__state_type>(
std::move(__fn));
1714 template<
typename _Fn,
typename... _Args>
1715 _GLIBCXX_NODISCARD future<__async_result_of<_Fn, _Args...>>
1716 async(
launch __policy, _Fn&& __fn, _Args&&... __args)
1719 if ((__policy & launch::async) == launch::async)
1723 __state = __future_base::_S_make_async_state(
1724 std::thread::__make_invoker(std::forward<_Fn>(__fn),
1725 std::forward<_Args>(__args)...)
1728 #if __cpp_exceptions
1731 if (__e.code() != errc::resource_unavailable_try_again
1732 || (__policy & launch::deferred) != launch::deferred)
1739 __state = __future_base::_S_make_deferred_state(
1740 std::thread::__make_invoker(std::forward<_Fn>(__fn),
1741 std::forward<_Args>(__args)...));
1743 return future<__async_result_of<_Fn, _Args...>>(__state);
1747 template<
typename _Fn,
typename... _Args>
1748 _GLIBCXX_NODISCARD
inline future<__async_result_of<_Fn, _Args...>>
1749 async(_Fn&& __fn, _Args&&... __args)
1751 return std::async(launch::async|launch::deferred,
1752 std::forward<_Fn>(__fn),
1753 std::forward<_Args>(__args)...);
1756 #endif // _GLIBCXX_ASYNC_ABI_COMPAT
1757 #endif // _GLIBCXX_HAS_GTHREADS
1760 _GLIBCXX_END_NAMESPACE_VERSION
1765 #endif // _GLIBCXX_FUTURE