48 lines
1007 B
C++
48 lines
1007 B
C++
//
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// SpinLock.hpp
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// Clock Signal
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//
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// Created by Thomas Harte on 14/02/2026.
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// Copyright © 2026 Thomas Harte. All rights reserved.
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//
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#pragma once
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#include <atomic>
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namespace Concurrency {
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enum class Barrier {
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Relaxed,
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AcquireRelease,
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};
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/*!
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A basic spin lock. Applies a memory barrier as per the template.
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Standard warnings apply: having revealed nothing to the scheduler, a holder of this lock might sleep
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and block other eligble work.
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*/
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template <Barrier type>
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class SpinLock {
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public:
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void lock() {
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while(flag_.test_and_set(LockMemoryOrder));
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}
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void unlock() {
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flag_.clear(UnlockMemoryOrder);
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}
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private:
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static constexpr auto LockMemoryOrder =
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type == Barrier::Relaxed ? std::memory_order::relaxed : std::memory_order::acquire;
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static constexpr auto UnlockMemoryOrder =
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type == Barrier::Relaxed ? std::memory_order::relaxed : std::memory_order::release;
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// Note to self: this is guaranteed to construct in a clear state since C++20.
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std::atomic_flag flag_;
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};
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}
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