poll.c

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/**
 * \file
 *
 * \author  Georg Hopp
 *
 * \copyright
 * Copyright © 2012  Georg Hopp
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <poll.h>
#include <errno.h>

#include "server.h"
#include "logger.h"

#include "utils/signalHandling.h"

#define POLLFD(ptr) ((struct pollfd *)(ptr))

int
serverPoll(Server this) {
    int events;

    /**
     * put all closed fds to end of array in O(this->nfds)
     */
    struct pollfd * fda = &(this->fds[2]);
    struct pollfd * fdb = &(this->fds[this->nfds-1]);

    while (fda <= fdb) {
        while (0 == fdb->fd && fda <= fdb) {
            fdb--;
            this->nfds--;
        }

        while (0 != fda->fd && fda <= fdb) fda++;

        if (fda < fdb) {
            memcpy(fda, fdb, sizeof(struct pollfd));
            fdb--;
            this->nfds--;
        }
    }

    /*
     * wait for handles to become ready
     */
    do {
        if (-1 == (events = poll(this->fds, this->nfds, -1))) {
            switch (errno) {
                default:
                case EBADF:
                case EINVAL:
                case ENOMEM:
                    doShutdown = 1;
                    // DROP THROUGH

                case EINTR:
                    loggerLog(this->logger, LOGGER_CRIT,
                            "poll systemcall failed: [%s] - service terminated",
                            strerror(errno));
            }
        }
    } while (! doShutdown && 0 >= events);

    return events;
}

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