/*
 * Copyright (c) 2004, 2005, 2007 Darren Tucker (dtucker at zip com au).
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "includes.h"
#if !defined(HAVE_PPOLL) || !defined(HAVE_POLL) || defined(BROKEN_POLL)

#include <sys/types.h>
#include <sys/time.h>
#ifdef HAVE_SYS_PARAM_H
# include <sys/param.h>
#endif
#ifdef HAVE_SYS_SELECT_H
# include <sys/select.h>
#endif

#include <errno.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include "bsd-poll.h"

#if !defined(HAVE_PPOLL) || defined(BROKEN_POLL)
/*
 * A minimal implementation of ppoll(2), built on top of pselect(2).
 *
 * Only supports POLLIN, POLLOUT and POLLPRI flags in pfd.events and
 * revents. Notably POLLERR, POLLHUP and POLLNVAL are not supported.
 *
 * Supports pfd.fd = -1 meaning "unused" although it's not standard.
 */

int
ppoll(struct pollfd *fds, nfds_t nfds, const struct timespec *tmoutp,
    const sigset_t *sigmask)
{
        nfds_t i;
        int ret, fd, maxfd = 0;
        fd_set readfds, writefds, exceptfds;

        for (i = 0; i < nfds; i++) {
                fd = fds[i].fd;
                if (fd != -1 && fd >= FD_SETSIZE) {
                        errno = EINVAL;
                        return -1;
                }
                maxfd = MAX(maxfd, fd);
        }

        /* populate event bit vectors for the events we're interested in */
        FD_ZERO(&readfds);
        FD_ZERO(&writefds);
        FD_ZERO(&exceptfds);
        for (i = 0; i < nfds; i++) {
                fd = fds[i].fd;
                if (fd == -1)
                        continue;
                if (fds[i].events & POLLIN)
                        FD_SET(fd, &readfds);
                if (fds[i].events & POLLOUT)
                        FD_SET(fd, &writefds);
                if (fds[i].events & POLLPRI)
                        FD_SET(fd, &exceptfds);
        }

        ret = pselect(maxfd + 1, &readfds, &writefds, &exceptfds, tmoutp, sigmask);

        /* scan through select results and set poll() flags */
        for (i = 0; i < nfds; i++) {
                fd = fds[i].fd;
                fds[i].revents = 0;
                if (fd == -1)
                        continue;
                if ((fds[i].events & POLLIN) && FD_ISSET(fd, &readfds))
                        fds[i].revents |= POLLIN;
                if ((fds[i].events & POLLOUT) && FD_ISSET(fd, &writefds))
                        fds[i].revents |= POLLOUT;
                if ((fds[i].events & POLLPRI) && FD_ISSET(fd, &exceptfds))
                        fds[i].revents |= POLLPRI;
        }

        return ret;
}
#endif /* !HAVE_PPOLL || BROKEN_POLL */

#if !defined(HAVE_POLL) || defined(BROKEN_POLL)
int
poll(struct pollfd *fds, nfds_t nfds, int timeout)
{
        struct timespec ts, *tsp = NULL;

        /* poll timeout is msec, ppoll is timespec (sec + nsec) */
        if (timeout >= 0) {
                ts.tv_sec = timeout / 1000;
                ts.tv_nsec = (timeout % 1000) * 1000000;
                tsp = &ts;
        }

        return ppoll(fds, nfds, tsp, NULL);
}
#endif /* !HAVE_POLL || BROKEN_POLL */

#endif /* !HAVE_PPOLL || !HAVE_POLL || BROKEN_POLL */