如何在非阻塞函数中将这个 write_all 转为通过 UDP 写入字节？

Question

我在 C 中有这个函数，我想用它在非阻塞模式下通过我的 udp 套接字写入字节。我应该完成“TO BE DONE”部分。任何人都可以帮助我了解该怎么做吗？回顾那里的写入功能是否有意义？

ssize_t nonblocking_write_all(int fd, const void *ptr, size_t n)
    {
        size_t n_left = n;
        while (n_left > 0) {
            ssize_t n_written = write(fd, ptr, n_left);
            if (n_written < 0) {
    
    /*** TO BE DONE START ***/
    
    
    /*** TO BE DONE END ***/
    
                if (n_left == n)
                    return -1; /* nothing has been written */
                else
                    break; /* we have written something */
            } else if (n_written == 0) {
                            continue;
            }
            n_left -= n_written;
            ptr += n_written;
        }
        assert(n - n_left >= 0);
        return n - n_left;
    }

Answer 1

这有效：n_written=nonblocking_write_all(fd,ptr,n_left);

如何在非阻塞函数中将这个 write_all 转为通过 UDP 写入字节？

How to turn this write_all in non blocking function to write bytes through UDP?

c

sockets

udp

send