驱动程序中的线程挂起与IPC的线程挂起流程为什么不一样？

发布于 2023-11-13 18:56:20 浏览：333 订阅该版

```c
//IPC 挂起
/* put thread to suspended thread list */
rt_ipc_list_suspend(&(event->parent.suspend_thread),
thread,
event->parent.parent.flag);

/* if there is a waiting timeout, active thread timer */
if (timeout > 0)
{
	/* 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));
}
...
//驱动挂起借助rt_wqueue_wait
static int serial_fops_read(struct dfs_fd *fd, void *buf, size_t count)
{
    int size = 0;
    rt_device_t device;

device = (rt_device_t)fd->data;

do
    {
        size = rt_device_read(device, -1,  buf, count);
        if (size <= 0)
        {
            if (fd->flags & O_NONBLOCK)
            {
                size = -EAGAIN;
                break;
            }

rt_wqueue_wait(&(device->wait_queue), 0, RT_WAITING_FOREVER);
        }
    }while (size <= 0);

return size;
}
```
为什么驱动程序中，和IPC不能是一样的流程，直接将需要挂起的线程直接挂在device不可以？还需要在搞一个中间的struct rt_wqueue wait_queue;？