loop.poll.c

unix环境高级编程的源代码

#include    "opend.h"
#include    <poll.h>
#include    <stropts.h>

void
loop(void)
{
    int                i, n, maxi, listenfd, clifd, nread;
    char            buf[MAXLINE];
    uid_t            uid;
    struct pollfd    *pollfd;

    if ( (pollfd = malloc(open_max() * sizeof(struct pollfd))) == NULL)
        err_sys("malloc error");

                /* obtain fd to listen for client requests on */
    if ( (listenfd = serv_listen(CS_OPEN)) < 0)
        log_sys("serv_listen error");
    client_add(listenfd, 0);    /* we use [0] for listenfd */
    pollfd[0].fd = listenfd;
    pollfd[0].events = POLLIN;
    maxi = 0;
    for ( ; ; ) {
        if ( (n = poll(pollfd, maxi + 1, INFTIM)) < 0)
            log_sys("select error");

        if (pollfd[0].revents & POLLIN) {
                    /* accept new client request */
            if ( (clifd = serv_accept(listenfd, &uid)) < 0)
                log_sys("serv_accept error: %d", clifd);
            i = client_add(clifd, uid);
            pollfd[i].fd = clifd;
            pollfd[i].events = POLLIN;
            if (i > maxi)
                maxi = i;
            log_msg("new connection: uid %d, fd %d", uid, clifd);
        }

        for (i = 1; i <= maxi; i++) {
            if ( (clifd = client[i].fd) < 0)
                continue;
            if (pollfd[i].revents & POLLHUP)
                goto hungup;
            else if (pollfd[i].revents & POLLIN) {
                        /* read argument buffer from client */
                if ( (nread = read(clifd, buf, MAXLINE)) < 0)
                    log_sys("read error on fd %d", clifd);
                else if (nread == 0) {
    hungup:
                    log_msg("closed: uid %d, fd %d",
                                        client[i].uid, clifd);
                    client_del(clifd);    /* client has closed conn */
                    pollfd[i].fd = -1;
                    close(clifd);
                } else            /* process client's rquest */
                    request(buf, nread, clifd, client[i].uid);
            }
        }
    }
}