未阻塞的tcp套接字如何在未能发送的数据包上通知应用程序。

Im working on a non-blocking C tcp sockets for linux system. I've read that in non-blocking mode, the "send" command will return "bytes sent" immediately if there is no error. I'm guessing this value returned does not actually mean that those data have been delivered to the destination but rather the data has been passed to kernel memory for it to handle further and send.Im working on a non-blocking C tcp sockets for