以流程图展现sys_recvfrom过程
时间: 2023-09-03 15:09:25 浏览: 155
以下是sys_recvfrom过程的流程图:
```
sys_recvfrom
|
+----------+--------+
| |
sockfd = sock_lookup_light() |
| |
(error handling if sockfd < 0) |
| |
+--------+----------+
|
+----------------------+----------------------+
| |
sk_wait_data() sk_receive_skb()
| |
+----------------------+----------------------+
|
+---------+--------+
| |
(error handling) |
| |
skb = skb_peek() |
| |
+------------+-------------+ |
| | |
(if skb is NULL) (if skb is not NULL)
| | |
sk_wait_data() sk_data_ready()
| | |
+------------+-------------+ |
| |
skb_dequeue() |
| |
+------------+-------------+ |
| | |
(if skb is NULL) (if skb is not NULL)
| | |
sk_wait_data() sk_data_ready()
| | |
+------------+-------------+ |
| |
(copy data to user buffer) |
| |
+------------+-------------+ |
| | |
| return 0 | |
| | |
+--------------------------+
```
以上是sys_recvfrom过程的流程图,它描述了该函数的执行流程。函数首先调用sock_lookup_light()查找套接字,然后等待数据到达。如果套接字接收缓冲区有数据,就从缓冲区中取出数据并将其拷贝到用户缓冲区中。如果套接字接收缓冲区没有数据,则等待数据到达。函数执行完后返回0。