内核将为您同步对底层文件描述符的访问，因此您不需要单独的互斥体.如果您使用的是TCP，则这种方法会出现问题，但是由于我们在谈论UDP，因此这应该是安全的，尽管不一定是***的方法.

The kernel will synchronize access to underlying file descriptor for you, so you don't need a separate mutex. There would be a problem with this approach if you were using TCP, but since we are talking about UDP this should be safe, though not necessarily best way.