58 lines
1.4 KiB
C++
58 lines
1.4 KiB
C++
#pragma once
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#include <luna/Atomic.h>
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#include <luna/Types.h>
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template <typename T, usize Size> class CircularQueue
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{
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enum
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{
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Capacity = Size + 1
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};
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public:
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CircularQueue()
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{
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}
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bool try_push(const T& value)
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{
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usize current_tail = m_tail.load(MemoryOrder::Relaxed);
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const usize new_tail = (current_tail + 1) % Capacity;
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if (new_tail == m_head.load(MemoryOrder::Acquire))
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{
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// Queue is full
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return false;
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}
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m_data[current_tail] = value;
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if (!m_tail.compare_exchange_strong(current_tail, new_tail, MemoryOrder::Release, MemoryOrder::Relaxed))
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{
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// Someone else updated the tail
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return false;
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}
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return true;
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}
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bool try_pop(T& value)
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{
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usize current_head = m_head.load(MemoryOrder::Relaxed);
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if (current_head == m_tail.load(MemoryOrder::Acquire))
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{
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// Queue is empty
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return false;
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}
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value = m_data[current_head];
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const usize new_head = (current_head + 1) % Capacity;
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if (!m_head.compare_exchange_strong(current_head, new_head, MemoryOrder::Release, MemoryOrder::Relaxed))
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{
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// Someone else updated the head
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return false;
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}
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return true;
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}
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private:
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T m_data[Capacity];
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Atomic<usize> m_head = 0;
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Atomic<usize> m_tail = 0;
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};
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