János Turánszki
55 lines
1.0 KiB
C++
55 lines
1.0 KiB
C++
#pragma once
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#include <atomic>
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#include <thread>
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#if defined(_M_ARM64) || defined(__arm64__)
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#ifdef _WIN32
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#include <intrin.h> // __yield()
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#else
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#include <arm_acle.h> // __yield()
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#endif // _WIN32
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#else
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#include <emmintrin.h> // _mm_pause()
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#endif // efined(_M_ARM64) || defined(__arm64__)
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namespace wi
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{
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class SpinLock
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{
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private:
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std::atomic_flag lck = ATOMIC_FLAG_INIT;
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public:
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inline void lock()
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{
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int spin = 0;
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while (!try_lock())
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{
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if (spin < 10)
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{
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// SMT thread swap can occur here:
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#if defined(_M_ARM64) || defined(__arm64__)
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__yield();
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#else
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_mm_pause();
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#endif // defined(_M_ARM64) || defined(__arm64__)
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}
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else
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{
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// OS thread swap can occur here. It is important to keep it as fallback, to avoid any chance of lockup by busy wait
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std::this_thread::yield();
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}
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spin++;
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}
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}
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inline bool try_lock()
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{
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return !lck.test_and_set(std::memory_order_acquire);
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}
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inline void unlock()
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{
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lck.clear(std::memory_order_release);
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}
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};
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}
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