48 lines
1.1 KiB
C++
48 lines
1.1 KiB
C++
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/*
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* Licensed under the Apache License Version 2.0 with LLVM Exceptions
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* (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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*
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* https://llvm.org/LICENSE.txt
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#pragma once
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#include <thread>
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#include <unifex/detail/prologue.hpp>
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namespace unifex {
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class spin_wait {
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public:
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spin_wait() noexcept = default;
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void wait() noexcept {
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if (count_++ < yield_threshold) {
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// TODO: _mm_pause();
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} else {
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if (count_ == 0) {
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count_ = yield_threshold;
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}
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std::this_thread::yield();
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}
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}
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private:
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static constexpr std::uint32_t yield_threshold = 20;
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std::uint32_t count_ = 0;
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};
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} // namespace unifex
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#include <unifex/detail/epilogue.hpp>
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