1 //===------------------------- future.cpp ---------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
12 #ifndef _LIBCPP_HAS_NO_THREADS
17 _LIBCPP_BEGIN_NAMESPACE_STD
19 class _LIBCPP_HIDDEN __future_error_category
23 virtual const char* name() const _NOEXCEPT;
24 virtual string message(int ev) const;
28 __future_error_category::name() const _NOEXCEPT
33 #if defined(__clang__)
34 #pragma clang diagnostic push
35 #pragma clang diagnostic ignored "-Wswitch"
36 #elif defined(__GNUC__) || defined(__GNUG__)
37 #pragma GCC diagnostic push
38 #pragma GCC diagnostic ignored "-Wswitch"
42 __future_error_category::message(int ev) const
44 switch (static_cast<future_errc>(ev))
46 case future_errc(0): // For backwards compatibility with C++11 (LWG 2056)
47 case future_errc::broken_promise:
48 return string("The associated promise has been destructed prior "
49 "to the associated state becoming ready.");
50 case future_errc::future_already_retrieved:
51 return string("The future has already been retrieved from "
52 "the promise or packaged_task.");
53 case future_errc::promise_already_satisfied:
54 return string("The state of the promise has already been set.");
55 case future_errc::no_state:
56 return string("Operation not permitted on an object without "
57 "an associated state.");
59 return string("unspecified future_errc value\n");
62 #if defined(__clang__)
63 #pragma clang diagnostic pop
64 #elif defined(__GNUC__) || defined(__GNUG__)
65 #pragma GCC diagnostic pop
69 future_category() _NOEXCEPT
71 static __future_error_category __f;
75 future_error::future_error(error_code __ec)
76 : logic_error(__ec.message()),
81 future_error::~future_error() _NOEXCEPT
86 __assoc_sub_state::__on_zero_shared() _NOEXCEPT
92 __assoc_sub_state::set_value()
94 unique_lock<mutex> __lk(__mut_);
96 __throw_future_error(future_errc::promise_already_satisfied);
97 __state_ |= __constructed | ready;
102 __assoc_sub_state::set_value_at_thread_exit()
104 unique_lock<mutex> __lk(__mut_);
106 __throw_future_error(future_errc::promise_already_satisfied);
107 __state_ |= __constructed;
108 __thread_local_data()->__make_ready_at_thread_exit(this);
112 __assoc_sub_state::set_exception(exception_ptr __p)
114 unique_lock<mutex> __lk(__mut_);
116 __throw_future_error(future_errc::promise_already_satisfied);
123 __assoc_sub_state::set_exception_at_thread_exit(exception_ptr __p)
125 unique_lock<mutex> __lk(__mut_);
127 __throw_future_error(future_errc::promise_already_satisfied);
129 __thread_local_data()->__make_ready_at_thread_exit(this);
133 __assoc_sub_state::__make_ready()
135 unique_lock<mutex> __lk(__mut_);
141 __assoc_sub_state::copy()
143 unique_lock<mutex> __lk(__mut_);
145 if (__exception_ != nullptr)
146 rethrow_exception(__exception_);
150 __assoc_sub_state::wait()
152 unique_lock<mutex> __lk(__mut_);
157 __assoc_sub_state::__sub_wait(unique_lock<mutex>& __lk)
161 if (__state_ & static_cast<unsigned>(deferred))
163 __state_ &= ~static_cast<unsigned>(deferred);
168 while (!__is_ready())
174 __assoc_sub_state::__execute()
176 __throw_future_error(future_errc::no_state);
179 future<void>::future(__assoc_sub_state* __state)
182 if (__state_->__has_future_attached())
183 __throw_future_error(future_errc::future_already_retrieved);
184 __state_->__add_shared();
185 __state_->__set_future_attached();
188 future<void>::~future()
191 __state_->__release_shared();
197 unique_ptr<__shared_count, __release_shared_count> __(__state_);
198 __assoc_sub_state* __s = __state_;
203 promise<void>::promise()
204 : __state_(new __assoc_sub_state)
208 promise<void>::~promise()
212 #ifndef _LIBCPP_NO_EXCEPTIONS
213 if (!__state_->__has_value() && __state_->use_count() > 1)
214 __state_->set_exception(make_exception_ptr(
215 future_error(make_error_code(future_errc::broken_promise))
217 #endif // _LIBCPP_NO_EXCEPTIONS
218 __state_->__release_shared();
223 promise<void>::get_future()
225 if (__state_ == nullptr)
226 __throw_future_error(future_errc::no_state);
227 return future<void>(__state_);
231 promise<void>::set_value()
233 if (__state_ == nullptr)
234 __throw_future_error(future_errc::no_state);
235 __state_->set_value();
239 promise<void>::set_exception(exception_ptr __p)
241 if (__state_ == nullptr)
242 __throw_future_error(future_errc::no_state);
243 __state_->set_exception(__p);
247 promise<void>::set_value_at_thread_exit()
249 if (__state_ == nullptr)
250 __throw_future_error(future_errc::no_state);
251 __state_->set_value_at_thread_exit();
255 promise<void>::set_exception_at_thread_exit(exception_ptr __p)
257 if (__state_ == nullptr)
258 __throw_future_error(future_errc::no_state);
259 __state_->set_exception_at_thread_exit(__p);
262 shared_future<void>::~shared_future()
265 __state_->__release_shared();
269 shared_future<void>::operator=(const shared_future& __rhs)
272 __rhs.__state_->__add_shared();
274 __state_->__release_shared();
275 __state_ = __rhs.__state_;
279 _LIBCPP_END_NAMESPACE_STD
281 #endif // !_LIBCPP_HAS_NO_THREADS