54 lines
1.7 KiB
C
54 lines
1.7 KiB
C
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#pragma once
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#include <stdatomic.h>
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#include "pxl8_types.h"
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#define PXL8_QUEUE_CAPACITY 256
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typedef struct pxl8_queue {
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void* items[PXL8_QUEUE_CAPACITY];
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atomic_uint write_idx;
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atomic_uint read_idx;
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} pxl8_queue;
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static inline void pxl8_queue_init(pxl8_queue* q) {
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atomic_store(&q->write_idx, 0);
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atomic_store(&q->read_idx, 0);
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for (u32 i = 0; i < PXL8_QUEUE_CAPACITY; i++) {
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q->items[i] = NULL;
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}
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}
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static inline bool pxl8_queue_push(pxl8_queue* q, void* item) {
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u32 w = atomic_load_explicit(&q->write_idx, memory_order_relaxed);
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u32 next = (w + 1) % PXL8_QUEUE_CAPACITY;
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if (next == atomic_load_explicit(&q->read_idx, memory_order_acquire)) {
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return false;
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}
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q->items[w] = item;
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atomic_store_explicit(&q->write_idx, next, memory_order_release);
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return true;
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}
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static inline void* pxl8_queue_pop(pxl8_queue* q) {
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u32 r = atomic_load_explicit(&q->read_idx, memory_order_relaxed);
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if (r == atomic_load_explicit(&q->write_idx, memory_order_acquire)) {
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return NULL;
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}
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void* item = q->items[r];
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atomic_store_explicit(&q->read_idx, (r + 1) % PXL8_QUEUE_CAPACITY, memory_order_release);
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return item;
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}
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static inline bool pxl8_queue_empty(const pxl8_queue* q) {
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return atomic_load_explicit(&((pxl8_queue*)q)->read_idx, memory_order_acquire) ==
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atomic_load_explicit(&((pxl8_queue*)q)->write_idx, memory_order_acquire);
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}
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static inline u32 pxl8_queue_count(const pxl8_queue* q) {
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u32 w = atomic_load_explicit(&((pxl8_queue*)q)->write_idx, memory_order_acquire);
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u32 r = atomic_load_explicit(&((pxl8_queue*)q)->read_idx, memory_order_acquire);
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return (w >= r) ? (w - r) : (PXL8_QUEUE_CAPACITY - r + w);
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}
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