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_);
95 #ifndef _LIBCPP_NO_EXCEPTIONS
97 throw future_error(make_error_code(future_errc::promise_already_satisfied));
99 __state_ |= __constructed | ready;
104 __assoc_sub_state::set_value_at_thread_exit()
106 unique_lock<mutex> __lk(__mut_);
107 #ifndef _LIBCPP_NO_EXCEPTIONS
109 throw future_error(make_error_code(future_errc::promise_already_satisfied));
111 __state_ |= __constructed;
112 __thread_local_data()->__make_ready_at_thread_exit(this);
116 __assoc_sub_state::set_exception(exception_ptr __p)
118 unique_lock<mutex> __lk(__mut_);
119 #ifndef _LIBCPP_NO_EXCEPTIONS
121 throw future_error(make_error_code(future_errc::promise_already_satisfied));
129 __assoc_sub_state::set_exception_at_thread_exit(exception_ptr __p)
131 unique_lock<mutex> __lk(__mut_);
132 #ifndef _LIBCPP_NO_EXCEPTIONS
134 throw future_error(make_error_code(future_errc::promise_already_satisfied));
137 __thread_local_data()->__make_ready_at_thread_exit(this);
141 __assoc_sub_state::__make_ready()
143 unique_lock<mutex> __lk(__mut_);
149 __assoc_sub_state::copy()
151 unique_lock<mutex> __lk(__mut_);
153 if (__exception_ != nullptr)
154 rethrow_exception(__exception_);
158 __assoc_sub_state::wait()
160 unique_lock<mutex> __lk(__mut_);
165 __assoc_sub_state::__sub_wait(unique_lock<mutex>& __lk)
169 if (__state_ & static_cast<unsigned>(deferred))
171 __state_ &= ~static_cast<unsigned>(deferred);
176 while (!__is_ready())
182 __assoc_sub_state::__execute()
184 #ifndef _LIBCPP_NO_EXCEPTIONS
185 throw future_error(make_error_code(future_errc::no_state));
189 future<void>::future(__assoc_sub_state* __state)
192 #ifndef _LIBCPP_NO_EXCEPTIONS
193 if (__state_->__has_future_attached())
194 throw future_error(make_error_code(future_errc::future_already_retrieved));
196 __state_->__add_shared();
197 __state_->__set_future_attached();
200 future<void>::~future()
203 __state_->__release_shared();
209 unique_ptr<__shared_count, __release_shared_count> __(__state_);
210 __assoc_sub_state* __s = __state_;
215 promise<void>::promise()
216 : __state_(new __assoc_sub_state)
220 promise<void>::~promise()
224 #ifndef _LIBCPP_NO_EXCEPTIONS
225 if (!__state_->__has_value() && __state_->use_count() > 1)
226 __state_->set_exception(make_exception_ptr(
227 future_error(make_error_code(future_errc::broken_promise))
229 #endif // _LIBCPP_NO_EXCEPTIONS
230 __state_->__release_shared();
235 promise<void>::get_future()
237 #ifndef _LIBCPP_NO_EXCEPTIONS
238 if (__state_ == nullptr)
239 throw future_error(make_error_code(future_errc::no_state));
241 return future<void>(__state_);
245 promise<void>::set_value()
247 #ifndef _LIBCPP_NO_EXCEPTIONS
248 if (__state_ == nullptr)
249 throw future_error(make_error_code(future_errc::no_state));
251 __state_->set_value();
255 promise<void>::set_exception(exception_ptr __p)
257 #ifndef _LIBCPP_NO_EXCEPTIONS
258 if (__state_ == nullptr)
259 throw future_error(make_error_code(future_errc::no_state));
261 __state_->set_exception(__p);
265 promise<void>::set_value_at_thread_exit()
267 #ifndef _LIBCPP_NO_EXCEPTIONS
268 if (__state_ == nullptr)
269 throw future_error(make_error_code(future_errc::no_state));
271 __state_->set_value_at_thread_exit();
275 promise<void>::set_exception_at_thread_exit(exception_ptr __p)
277 #ifndef _LIBCPP_NO_EXCEPTIONS
278 if (__state_ == nullptr)
279 throw future_error(make_error_code(future_errc::no_state));
281 __state_->set_exception_at_thread_exit(__p);
284 shared_future<void>::~shared_future()
287 __state_->__release_shared();
291 shared_future<void>::operator=(const shared_future& __rhs)
294 __rhs.__state_->__add_shared();
296 __state_->__release_shared();
297 __state_ = __rhs.__state_;
301 _LIBCPP_END_NAMESPACE_STD
303 #endif // !_LIBCPP_HAS_NO_THREADS