c++实现一个无锁队列linux版本

无锁队列是一种高效的数据结构，它可以在多线程环境下实现快速的数据传输。下面是一个简单的无锁队列的Linux版本实现：

#include <stdatomic.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>

typedef void* queue_value_t;

typedef struct queue_node {
    queue_value_t value;
    atomic_ptr_t next;
} queue_node_t;

typedef struct queue {
    atomic_ptr_t head;
    atomic_ptr_t tail;
} queue_t;

queue_t* queue_create()
{
    queue_t* queue = (queue_t*)malloc(sizeof(queue_t));
    queue_node_t* node = (queue_node_t*)malloc(sizeof(queue_node_t));
    node->next = NULL;
    queue->head = queue->tail = node;
    return queue;
}

void queue_destroy(queue_t* queue)
{
    queue_node_t* node = (queue_node_t*)queue->head;
    while(node) {
        queue_node_t* next = (queue_node_t*)atomic_load(&node->next);
        free(node);
        node = next;
    }
    free(queue);
}

bool queue_push(queue_t* queue, queue_value_t value)
{
    queue_node_t* node = (queue_node_t*)malloc(sizeof(queue_node_t));
    node->value = value;
    node->next = NULL;
    queue_node_t* tail = (queue_node_t*)atomic_load_explicit(&queue->tail, memory_order_relaxed);
    while(true) {
        queue_node_t* next = (queue_node_t*)atomic_load_explicit(&tail->next, memory_order_acquire);
        if(next == NULL) {
            if(atomic_compare_exchange_weak_explicit(&tail->next, &next, node, memory_order_release, memory_order_relaxed)) {
                break;
            }
        } else {
            atomic_compare_exchange_weak_explicit(&queue->tail, &tail, next, memory_order_release, memory_order_relaxed);
        }
    }
    atomic_compare_exchange_weak_explicit(&queue->tail, &tail, node, memory_order_release, memory_order_relaxed);
    return true;
}

bool queue_pop(queue_t* queue, queue_value_t* value)
{
    queue_node_t* head = (queue_node_t*)atomic_load_explicit(&queue->head, memory_order_relaxed);
    while(true) {
        queue_node_t* tail = (queue_node_t*)atomic_load_explicit(&queue->tail, memory_order_acquire);
        queue_node_t* next = (queue_node_t*)atomic_load_explicit(&head->next, memory_order_acquire);
        if(head == (queue_node_t*)atomic_load_explicit(&queue->head, memory_order_relaxed)) {
            if(head == tail) {
                if(next == NULL) {
                    return false;
                }
                atomic_compare_exchange_weak_explicit(&queue->tail, &tail, next, memory_order_release, memory_order_relaxed);
            } else {
                *value = next->value;
                if(atomic_compare_exchange_weak_explicit(&queue->head, &head, next, memory_order_release, memory_order_relaxed)) {
                    free(head);
                    break;
                }
            }
        }
    }
    return true;
}

这个实现使用了atomic库中提供的原子操作，保证了多线程环境下的数据安全。在push()函数中，我们使用了循环来不断尝试插入新节点，直到成功为止。在pop()函数中，我们使用了判断队列是否为空的方法来决定是否弹出元素。如果队列不为空，则直接从队列头部弹出元素。如果队列为空，则返回false。