5 ipc对象插入时既有优先级模式，又有ffio模式会不会出bug？

发布于 2021-11-25 14:18:38 浏览：680 订阅该版

/*
如果flag是fifo就调用 rt_list_insert_before(list, &(thread->tlist))
插入，这时候并不是按优先级插入list的，flag 是RT_IPC_FLAG_PRIO就先查
出该优先级所处的位置然后按优先级插入。都是同一个list，这时如果既有fifo
也有prio的，那下一次按照优先级查找的时候查到了那个按照fifo模式插入的节点
会不会造成下次查找的结果是错误的？
*/
```c
rt_inline rt_err_t rt_ipc_list_suspend(rt_list_t        *list,
                                       struct rt_thread *thread,
                                       rt_uint8_t        flag)
{
    /* suspend thread */
    rt_thread_suspend(thread);

switch (flag)
    {
    case RT_IPC_FLAG_FIFO:
        rt_list_insert_before(list, &(thread->tlist));
        break;

case RT_IPC_FLAG_PRIO:
        {
            struct rt_list_node *n;
            struct rt_thread *sthread;

/* find a suitable position */
            for (n = list->next; n != list; n = n->next)
            {
                sthread = rt_list_entry(n, struct rt_thread, tlist);

/* find out */
                if (thread->current_priority < sthread->current_priority)
                {
                    /* insert this thread before the sthread */
                    rt_list_insert_before(&(sthread->tlist), &(thread->tlist));
                    break;
                }
            }

/*
             * not found a suitable position,
             * append to the end of suspend_thread list
             */
            if (n == list)
                rt_list_insert_before(list, &(thread->tlist));
        }
        break;
    }

return RT_EOK;
}
```