消息队列经常被充满，但是取数据取出来又是空的

发布于 2021-09-02 18:08:17 浏览：1763 订阅该版

2 个回答

出出啊 2021-09-02

恃人不如自恃，人之为己者不如己之自为也

sync 2021-09-03

这家伙很懒，什么也没写！

源码在这
```c
/**
 * This function will initialize a message queue and put it under control of
 * resource management.
 *
 * @param mq the message object
 * @param name the name of message queue
 * @param msgpool the beginning address of buffer to save messages
 * @param msg_size the maximum size of message
 * @param pool_size the size of buffer to save messages
 * @param flag the flag of message queue
 *
 * @return the operation status, RT_EOK on successful
 */
rt_err_t rt_mq_init(rt_mq_t     mq,
                    const char *name,
                    void       *msgpool,
                    rt_size_t   msg_size,
                    rt_size_t   pool_size,
                    rt_uint8_t  flag)
{
    struct rt_mq_message *head;
    register rt_base_t temp;

/* parameter check */
    RT_ASSERT(mq != RT_NULL);

/* init object */
    rt_object_init(&(mq->parent.parent), RT_Object_Class_MessageQueue, name);

/* set parent flag */
    mq->parent.parent.flag = flag;

/* init ipc object */
    rt_ipc_object_init(&(mq->parent));

/* set messasge pool */
    mq->msg_pool = msgpool;

/* get correct message size */
    mq->msg_size = RT_ALIGN(msg_size, RT_ALIGN_SIZE);
    mq->max_msgs = pool_size / (mq->msg_size + sizeof(struct rt_mq_message));

/* init message list */
    mq->msg_queue_head = RT_NULL;
    mq->msg_queue_tail = RT_NULL;

/* init message empty list */
    mq->msg_queue_free = RT_NULL;
    for (temp = 0; temp < mq->max_msgs; temp ++)
    {
        head = (struct rt_mq_message *)((rt_uint8_t *)mq->msg_pool +
                                        temp * (mq->msg_size + sizeof(struct rt_mq_message)));
        head->next = (struct rt_mq_message *)mq->msg_queue_free;
        mq->msg_queue_free = head;
    }

/* the initial entry is zero */
    mq->entry = 0;

return RT_EOK;
}
```