aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/cxxsupp/libcxx/src/future.cpp
blob: cdaa93827533d99ec05ec6e7b4b2848ea31676c0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include <__config>

#ifndef _LIBCPP_HAS_NO_THREADS

#include <future>
#include <string>

_LIBCPP_BEGIN_NAMESPACE_STD

class _LIBCPP_HIDDEN __future_error_category
    : public __do_message
{
public:
    virtual const char* name() const noexcept;
    virtual string message(int ev) const;
};

const char*
__future_error_category::name() const noexcept
{
    return "future";
}

_LIBCPP_DIAGNOSTIC_PUSH
_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wswitch")
_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wswitch")

string
__future_error_category::message(int ev) const
{
    switch (static_cast<future_errc>(ev))
    {
    case future_errc(0):  // For backwards compatibility with C++11 (LWG 2056)
    case future_errc::broken_promise:
        return string("The associated promise has been destructed prior "
                      "to the associated state becoming ready.");
    case future_errc::future_already_retrieved:
        return string("The future has already been retrieved from "
                      "the promise or packaged_task.");
    case future_errc::promise_already_satisfied:
        return string("The state of the promise has already been set.");
    case future_errc::no_state:
        return string("Operation not permitted on an object without "
                      "an associated state.");
    }
    return string("unspecified future_errc value\n");
}

_LIBCPP_DIAGNOSTIC_POP

const error_category&
future_category() noexcept
{
    static __future_error_category __f;
    return __f;
}

future_error::future_error(error_code __ec)
    : logic_error(__ec.message()),
      __ec_(__ec)
{
}

future_error::~future_error() noexcept
{
}

void
__assoc_sub_state::__on_zero_shared() noexcept
{
    delete this;
}

void
__assoc_sub_state::set_value()
{
    unique_lock<mutex> __lk(__mut_);
    if (__has_value())
        __throw_future_error(future_errc::promise_already_satisfied);
    __state_ |= __constructed | ready;
    __cv_.notify_all();
}

void
__assoc_sub_state::set_value_at_thread_exit()
{
    unique_lock<mutex> __lk(__mut_);
    if (__has_value())
        __throw_future_error(future_errc::promise_already_satisfied);
    __state_ |= __constructed;
    __thread_local_data()->__make_ready_at_thread_exit(this);
}

void
__assoc_sub_state::set_exception(exception_ptr __p)
{
    unique_lock<mutex> __lk(__mut_);
    if (__has_value())
        __throw_future_error(future_errc::promise_already_satisfied);
    __exception_ = __p;
    __state_ |= ready;
    __cv_.notify_all();
}

void
__assoc_sub_state::set_exception_at_thread_exit(exception_ptr __p)
{
    unique_lock<mutex> __lk(__mut_);
    if (__has_value())
        __throw_future_error(future_errc::promise_already_satisfied);
    __exception_ = __p;
    __thread_local_data()->__make_ready_at_thread_exit(this);
}

void
__assoc_sub_state::__make_ready()
{
    unique_lock<mutex> __lk(__mut_);
    __state_ |= ready;
    __cv_.notify_all();
}

void
__assoc_sub_state::copy()
{
    unique_lock<mutex> __lk(__mut_);
    __sub_wait(__lk);
    if (__exception_ != nullptr)
        rethrow_exception(__exception_);
}

void
__assoc_sub_state::wait()
{
    unique_lock<mutex> __lk(__mut_);
    __sub_wait(__lk);
}

void
__assoc_sub_state::__sub_wait(unique_lock<mutex>& __lk)
{
    if (!__is_ready())
    {
        if (__state_ & static_cast<unsigned>(deferred))
        {
            __state_ &= ~static_cast<unsigned>(deferred);
            __lk.unlock();
            __execute();
        }
        else
            while (!__is_ready())
                __cv_.wait(__lk);
    }
}

void
__assoc_sub_state::__execute()
{
    __throw_future_error(future_errc::no_state);
}

future<void>::future(__assoc_sub_state* __state)
    : __state_(__state)
{
    __state_->__attach_future();
}

future<void>::~future()
{
    if (__state_)
        __state_->__release_shared();
}

void
future<void>::get()
{
    unique_ptr<__shared_count, __release_shared_count> __(__state_);
    __assoc_sub_state* __s = __state_;
    __state_ = nullptr;
    __s->copy();
}

promise<void>::promise()
    : __state_(new __assoc_sub_state)
{
}

promise<void>::~promise()
{
    if (__state_)
    {
#ifndef _LIBCPP_NO_EXCEPTIONS
        if (!__state_->__has_value() && __state_->use_count() > 1)
            __state_->set_exception(make_exception_ptr(
                      future_error(make_error_code(future_errc::broken_promise))
                                                      ));
#endif // _LIBCPP_NO_EXCEPTIONS
        __state_->__release_shared();
    }
}

future<void>
promise<void>::get_future()
{
    if (__state_ == nullptr)
        __throw_future_error(future_errc::no_state);
    return future<void>(__state_);
}

void
promise<void>::set_value()
{
    if (__state_ == nullptr)
        __throw_future_error(future_errc::no_state);
    __state_->set_value();
}

void
promise<void>::set_exception(exception_ptr __p)
{
    if (__state_ == nullptr)
        __throw_future_error(future_errc::no_state);
    __state_->set_exception(__p);
}

void
promise<void>::set_value_at_thread_exit()
{
    if (__state_ == nullptr)
        __throw_future_error(future_errc::no_state);
    __state_->set_value_at_thread_exit();
}

void
promise<void>::set_exception_at_thread_exit(exception_ptr __p)
{
    if (__state_ == nullptr)
        __throw_future_error(future_errc::no_state);
    __state_->set_exception_at_thread_exit(__p);
}

shared_future<void>::~shared_future()
{
    if (__state_)
        __state_->__release_shared();
}

shared_future<void>&
shared_future<void>::operator=(const shared_future& __rhs)
{
    if (__rhs.__state_)
        __rhs.__state_->__add_shared();
    if (__state_)
        __state_->__release_shared();
    __state_ = __rhs.__state_;
    return *this;
}

_LIBCPP_END_NAMESPACE_STD

#endif // !_LIBCPP_HAS_NO_THREADS