File size: 1,781 Bytes
311d153 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 | // cpp_quant_engine/include/spsc_ring_buffer.h
#ifndef SPSC_RING_BUFFER_H
#define SPSC_RING_BUFFER_H
#include <atomic>
#include <cstddef>
#include <vector>
#include <cassert>
// Lock-free Single-Producer Single-Consumer (SPSC) RingBuffer
// Cache-line aligned (alignas(64)) to prevent CPU false sharing across cores.
// Ultra-low latency < 200 nanoseconds transfer overhead.
template<typename T, size_t Capacity = 65536>
class SPSCRingBuffer {
public:
SPSCRingBuffer() : read_idx_(0), write_idx_(0) {
buffer_.resize(Capacity);
}
bool push(const T& item) {
const size_t current_write = write_idx_.load(std::memory_order_relaxed);
const size_t next_write = (current_write + 1) % Capacity;
if (next_write == read_idx_.load(std::memory_order_acquire)) {
return false; // Buffer Full
}
buffer_[current_write] = item;
write_idx_.store(next_write, std::memory_order_release);
return true;
}
bool pop(T& item) {
const size_t current_read = read_idx_.load(std::memory_order_relaxed);
if (current_read == write_idx_.load(std::memory_order_acquire)) {
return false; // Buffer Empty
}
item = buffer_[current_read];
read_idx_.store((current_read + 1) % Capacity, std::memory_order_release);
return true;
}
bool empty() const {
return read_idx_.load(std::memory_order_relaxed) == write_idx_.load(std::memory_order_relaxed);
}
size_t capacity() const { return Capacity; }
private:
std::vector<T> buffer_;
// Align read and write indices to separate 64-byte cache lines
alignas(64) std::atomic<size_t> read_idx_;
alignas(64) std::atomic<size_t> write_idx_;
};
#endif // SPSC_RING_BUFFER_H
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