xref: /freebsd-src/contrib/llvm-project/libcxx/include/__stop_token/stop_source.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
106c3fb27SDimitry Andric // -*- C++ -*-
206c3fb27SDimitry Andric //===----------------------------------------------------------------------===//
306c3fb27SDimitry Andric //
406c3fb27SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
506c3fb27SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
606c3fb27SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
706c3fb27SDimitry Andric //
806c3fb27SDimitry Andric //===----------------------------------------------------------------------===//
906c3fb27SDimitry Andric 
1006c3fb27SDimitry Andric #ifndef _LIBCPP___STOP_TOKEN_STOP_SOURCE_H
1106c3fb27SDimitry Andric #define _LIBCPP___STOP_TOKEN_STOP_SOURCE_H
1206c3fb27SDimitry Andric 
1306c3fb27SDimitry Andric #include <__config>
1406c3fb27SDimitry Andric #include <__stop_token/intrusive_shared_ptr.h>
1506c3fb27SDimitry Andric #include <__stop_token/stop_state.h>
1606c3fb27SDimitry Andric #include <__stop_token/stop_token.h>
1706c3fb27SDimitry Andric #include <__utility/move.h>
1806c3fb27SDimitry Andric 
1906c3fb27SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
2006c3fb27SDimitry Andric #  pragma GCC system_header
2106c3fb27SDimitry Andric #endif
2206c3fb27SDimitry Andric 
2306c3fb27SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
2406c3fb27SDimitry Andric 
25*5f757f3fSDimitry Andric #if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && !defined(_LIBCPP_HAS_NO_THREADS)
2606c3fb27SDimitry Andric 
2706c3fb27SDimitry Andric struct nostopstate_t {
2806c3fb27SDimitry Andric   explicit nostopstate_t() = default;
2906c3fb27SDimitry Andric };
3006c3fb27SDimitry Andric 
3106c3fb27SDimitry Andric inline constexpr nostopstate_t nostopstate{};
3206c3fb27SDimitry Andric 
3306c3fb27SDimitry Andric class _LIBCPP_AVAILABILITY_SYNC stop_source {
3406c3fb27SDimitry Andric public:
3506c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI stop_source() : __state_(new __stop_state()) { __state_->__increment_stop_source_counter(); }
3606c3fb27SDimitry Andric 
3706c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI explicit stop_source(nostopstate_t) noexcept : __state_(nullptr) {}
3806c3fb27SDimitry Andric 
3906c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI stop_source(const stop_source& __other) noexcept : __state_(__other.__state_) {
4006c3fb27SDimitry Andric     if (__state_) {
4106c3fb27SDimitry Andric       __state_->__increment_stop_source_counter();
4206c3fb27SDimitry Andric     }
4306c3fb27SDimitry Andric   }
4406c3fb27SDimitry Andric 
4506c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI stop_source(stop_source&& __other) noexcept = default;
4606c3fb27SDimitry Andric 
4706c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI stop_source& operator=(const stop_source& __other) noexcept {
4806c3fb27SDimitry Andric     // increment `__other` first so that we don't hit 0 in case of self-assignment
4906c3fb27SDimitry Andric     if (__other.__state_) {
5006c3fb27SDimitry Andric       __other.__state_->__increment_stop_source_counter();
5106c3fb27SDimitry Andric     }
5206c3fb27SDimitry Andric     if (__state_) {
5306c3fb27SDimitry Andric       __state_->__decrement_stop_source_counter();
5406c3fb27SDimitry Andric     }
5506c3fb27SDimitry Andric     __state_ = __other.__state_;
5606c3fb27SDimitry Andric     return *this;
5706c3fb27SDimitry Andric   }
5806c3fb27SDimitry Andric 
5906c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI stop_source& operator=(stop_source&&) noexcept = default;
6006c3fb27SDimitry Andric 
6106c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI ~stop_source() {
6206c3fb27SDimitry Andric     if (__state_) {
6306c3fb27SDimitry Andric       __state_->__decrement_stop_source_counter();
6406c3fb27SDimitry Andric     }
6506c3fb27SDimitry Andric   }
6606c3fb27SDimitry Andric 
6706c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI void swap(stop_source& __other) noexcept { __state_.swap(__other.__state_); }
6806c3fb27SDimitry Andric 
6906c3fb27SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI stop_token get_token() const noexcept { return stop_token(__state_); }
7006c3fb27SDimitry Andric 
7106c3fb27SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool stop_possible() const noexcept { return __state_ != nullptr; }
7206c3fb27SDimitry Andric 
7306c3fb27SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool stop_requested() const noexcept {
7406c3fb27SDimitry Andric     return __state_ != nullptr && __state_->__stop_requested();
7506c3fb27SDimitry Andric   }
7606c3fb27SDimitry Andric 
7706c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI bool request_stop() noexcept { return __state_ && __state_->__request_stop(); }
7806c3fb27SDimitry Andric 
7906c3fb27SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend bool operator==(const stop_source&, const stop_source&) noexcept = default;
8006c3fb27SDimitry Andric 
8106c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI friend void swap(stop_source& __lhs, stop_source& __rhs) noexcept { __lhs.swap(__rhs); }
8206c3fb27SDimitry Andric 
8306c3fb27SDimitry Andric private:
8406c3fb27SDimitry Andric   __intrusive_shared_ptr<__stop_state> __state_;
8506c3fb27SDimitry Andric };
8606c3fb27SDimitry Andric 
8706c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20
8806c3fb27SDimitry Andric 
8906c3fb27SDimitry Andric _LIBCPP_END_NAMESPACE_STD
9006c3fb27SDimitry Andric 
91*5f757f3fSDimitry Andric #endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && !defined(_LIBCPP_HAS_NO_THREADS)
92