消息队列接收rt_mq_recv是否存在缺陷？

发布于 2020-04-29 10:47:17 浏览：1973 订阅该版

* 本帖最后由 jszhou 于 2020-4-29 11:01 编辑 *

现在问题是这样的，我发现接收完消息队列后，msg_pool里面的数据并没有被清空，以下是我的代码：```static struct rt_messagequeue usbmq;
static rt_uint8_t msg_pool[5][1024];``````rt_mq_init(&usbmq, "usbmqg", &msg_pool, sizeof(msg_pool[0]), sizeof(msg_pool), RT_IPC_FLAG_FIFO);``````rt_mq_send(&usbmq, keyboard_recev_data_pro.data, keyboard_recev_data_pro.len);

rt_memset(keyboard_recev_data_pro.data, 0x00, keyboard_recev_data_pro.len);

keyboard_recev_data_pro.len = 0;``````   if((usbmq_hid_recv(hidbuf) == RT_EOK))
			{						
				hidbuflen = rt_strlen(hidbuf); 
				......//这里是我的数据处理接口	
				rt_memset(hidbuf, 0x00, hidbuflen);
				hidbuflen = 0;					
			}```当我把内核ipc.c的rt_mq_recv改成如下代码时(加了一个清空的函数)，问题就没有了
```rt_err_t rt_mq_recv(rt_mq_t    mq,
                    void      *buffer,
                    rt_size_t  size,
                    rt_int32_t timeout)
{
    struct rt_thread *thread;
    register rt_ubase_t temp;
    struct rt_mq_message *msg;
    rt_uint32_t tick_delta;

RT_ASSERT(mq != RT_NULL);
    RT_ASSERT(buffer != RT_NULL);
    RT_ASSERT(size != 0);

/* initialize delta tick */
    tick_delta = 0;
    /* get current thread */
    thread = rt_thread_self();
    RT_OBJECT_HOOK_CALL(rt_object_trytake_hook, (&(mq->parent.parent)));

/* disable interrupt */
    temp = rt_hw_interrupt_disable();

/* for non-blocking call */
    if (mq->entry == 0 && timeout == 0)
    {
        rt_hw_interrupt_enable(temp);

return -RT_ETIMEOUT;
    }

/* message queue is empty */
    while (mq->entry == 0)
    {
        RT_DEBUG_IN_THREAD_CONTEXT;

/* reset error number in thread */
        thread->error = RT_EOK;

/* no waiting, return timeout */
        if (timeout == 0)
        {
            /* enable interrupt */
            rt_hw_interrupt_enable(temp);

thread->error = -RT_ETIMEOUT;

return -RT_ETIMEOUT;
        }

/* suspend current thread */
        rt_ipc_list_suspend(&(mq->parent.suspend_thread),
                            thread,
                            mq->parent.parent.flag);

/* has waiting time, start thread timer */
        if (timeout > 0)
        {
            /* get the start tick of timer */
            tick_delta = rt_tick_get();

RT_DEBUG_LOG(RT_DEBUG_IPC, ("set thread:%s to timer list<br>",
                                        thread->name));

/* reset the timeout of thread timer and start it */
            rt_timer_control(&(thread->thread_timer),
                             RT_TIMER_CTRL_SET_TIME,
                             &timeout);
            rt_timer_start(&(thread->thread_timer));
        }

/* enable interrupt */
        rt_hw_interrupt_enable(temp);

/* re-schedule */
        rt_schedule();

/* recv message */
        if (thread->error != RT_EOK)
        {
            /* return error */
            return thread->error;
        }

/* disable interrupt */
        temp = rt_hw_interrupt_disable();

/* if it's not waiting forever and then re-calculate timeout tick */
        if (timeout > 0)
        {
            tick_delta = rt_tick_get() - tick_delta;
            timeout -= tick_delta;
            if (timeout < 0)
                timeout = 0;
        }
    }

/* get message from queue */
    msg = (struct rt_mq_message *)mq->msg_queue_head;

/* move message queue head */
    mq->msg_queue_head = msg->next;
    /* reach queue tail, set to NULL */
    if (mq->msg_queue_tail == msg)
        mq->msg_queue_tail = RT_NULL;

/* decrease message entry */
    mq->entry --;

/* enable interrupt */
    rt_hw_interrupt_enable(temp);

/* copy message */
    rt_memcpy(buffer, msg + 1, size > mq->msg_size ? mq->msg_size : size);
		
		rt_memset(msg + 1, 0x00, size > mq->msg_size ? mq->msg_size : size); //这里是我添加的测试代码

/* disable interrupt */
    temp = rt_hw_interrupt_disable();
    /* put message to free list */
    msg->next = (struct rt_mq_message *)mq->msg_queue_free;
    mq->msg_queue_free = msg;
    /* enable interrupt */
    rt_hw_interrupt_enable(temp);

RT_OBJECT_HOOK_CALL(rt_object_take_hook, (&(mq->parent.parent)));

return RT_EOK;
}```不知道这个算不算是原来ipc消息队列接收机制的缺陷，还是我用法有什么问题，还请官方大佬给指点指点！！！