477f6bc407
There are discussions about different ways of implementing `stop_token` to make it more performant mark `stop_token` as experimental to allow us to change the design before it is shipped Co-authored-by: Louis Dionne <ldionne.2@gmail.com> Differential Revision: https://reviews.llvm.org/D154700
96 lines
2.4 KiB
C++
96 lines
2.4 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// UNSUPPORTED: no-threads
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// UNSUPPORTED: libcpp-has-no-experimental-stop_token
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// UNSUPPORTED: c++03, c++11, c++14, c++17
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// XFAIL: availability-synchronization_library-missing
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// [[nodiscard]] bool stop_possible() const noexcept;
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// Returns: false if:
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// - *this does not have ownership of a stop state, or
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// - a stop request was not made and there are no associated stop_source objects;
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// otherwise, true.
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#include <cassert>
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#include <concepts>
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#include <optional>
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#include <stop_token>
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#include <type_traits>
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#include "make_test_thread.h"
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#include "test_macros.h"
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template <class T>
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concept IsStopPossibleNoexcept = requires(const T& t) {
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{ t.stop_possible() } noexcept;
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};
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static_assert(IsStopPossibleNoexcept<std::stop_token>);
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int main(int, char**) {
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// no state
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{
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const std::stop_token st;
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assert(!st.stop_possible());
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}
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// a stop request was not made and there are no associated stop_source objects
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{
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std::optional<std::stop_source> ss{std::in_place};
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const auto st = ss->get_token();
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ss.reset();
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assert(!st.stop_possible());
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}
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// a stop request was not made, but there is an associated stop_source objects
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{
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std::stop_source ss;
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const auto st = ss.get_token();
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assert(st.stop_possible());
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}
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// a stop request was made and there are no associated stop_source objects
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{
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std::optional<std::stop_source> ss{std::in_place};
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const auto st = ss->get_token();
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ss->request_stop();
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ss.reset();
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assert(st.stop_possible());
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}
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// a stop request was made and there is an associated stop_source objects
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{
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std::stop_source ss;
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const auto st = ss.get_token();
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ss.request_stop();
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assert(st.stop_possible());
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}
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// a stop request was made on a different thread and
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// there are no associated stop_source objects
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{
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std::optional<std::stop_source> ss{std::in_place};
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const auto st = ss->get_token();
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std::thread t = support::make_test_thread([&]() {
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ss->request_stop();
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ss.reset();
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});
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assert(st.stop_possible());
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t.join();
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assert(st.stop_possible());
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}
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return 0;
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}
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