str_cli_poll03.c

unix网络编程卷1：套接口API的全书源码

#include	"unp.h"
#include	<sys/devpoll.h>

void
str_cli(FILE *fp, int sockfd)
{
	int		stdineof;
	char		buf[MAXLINE];
	int		n;
	int		wfd;
	struct pollfd	pollfd[2];
	struct dvpoll	dopoll;
	int		i;
	int		result;

	wfd = Open("/dev/poll", O_RDWR, 0);

	pollfd[0].fd = fileno(fp);
	pollfd[0].events = POLLIN;
	pollfd[0].revents = 0;

	pollfd[1].fd = sockfd;
	pollfd[1].events = POLLIN;
	pollfd[1].revents = 0;

	Write(wfd, pollfd, sizeof(struct pollfd) * 2);

	stdineof = 0;
	for ( ; ; ) {
		/* block until /dev/poll says something is ready */
		dopoll.dp_timeout = -1;
		dopoll.dp_nfds = 2;
		dopoll.dp_fds = pollfd;
		result = Ioctl(wfd, DP_POLL, &dopoll);

		/* loop through ready file descriptors */
		for (i = 0; i < result; i++) {
			if (dopoll.dp_fds[i].fd == sockfd) {
				/* socket is readable */
				if ( (n = Read(sockfd, buf, MAXLINE)) == 0) {
					if (stdineof == 1)
						return;		/* normal termination */
					else
						err_quit("str_cli: server terminated prematurely");
				}

				Write(fileno(stdout), buf, n);
			} else {
				/* input is readable */
				if ( (n = Read(fileno(fp), buf, MAXLINE)) == 0) {
					stdineof = 1;
					Shutdown(sockfd, SHUT_WR);	/* send FIN */
					continue;
				}

				Writen(sockfd, buf, n);
			}
		}
	}
}