uloop-kqueue.c

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/*
 * uloop - event loop implementation
 *
 * Copyright (C) 2010-2016 Felix Fietkau <nbd@openwrt.org>
 *
 * Permission to use, copy, modify, and/or 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.
 */
static int uloop_init_pollfd(void)
{
        struct timespec timeout = { 0, 0 };
        struct kevent ev = {};
 
        if (poll_fd >= 0)
                return 0;
 
        poll_fd = kqueue();
        if (poll_fd < 0)
                return -1;
 
        EV_SET(&ev, SIGCHLD, EVFILT_SIGNAL, EV_ADD, 0, 0, 0);
        kevent(poll_fd, &ev, 1, NULL, 0, &timeout);
 
        return 0;
}
 
 
static uint16_t get_flags(unsigned int flags, unsigned int mask)
{
        uint16_t kflags = 0;
 
        if (!(flags & mask))
                return EV_DELETE;
 
        kflags = EV_ADD;
        if (flags & ULOOP_EDGE_TRIGGER)
                kflags |= EV_CLEAR;
 
        return kflags;
}
 
static struct kevent events[ULOOP_MAX_EVENTS];
 
static int register_kevent(struct uloop_fd *fd, unsigned int flags)
{
        struct timespec timeout = { 0, 0 };
        struct kevent ev[2];
        int nev = 0;
        unsigned int fl = 0;
        unsigned int changed;
        uint16_t kflags;
 
        if (flags & ULOOP_EDGE_DEFER)
                flags &= ~ULOOP_EDGE_TRIGGER;
 
        changed = flags ^ fd->flags;
        if (changed & ULOOP_EDGE_TRIGGER)
                changed |= flags;
 
        if (!changed)
                return 0;
 
        if (changed & ULOOP_READ) {
                kflags = get_flags(flags, ULOOP_READ);
                EV_SET(&ev[nev++], fd->fd, EVFILT_READ, kflags, 0, 0, fd);
        }
 
        if (changed & ULOOP_WRITE) {
                kflags = get_flags(flags, ULOOP_WRITE);
                EV_SET(&ev[nev++], fd->fd, EVFILT_WRITE, kflags, 0, 0, fd);
        }
 
        if (!flags)
                fl |= EV_DELETE;
 
        if (kevent(poll_fd, ev, nev, NULL, fl, &timeout) == -1)
                return -1;
 
        return 0;
}
 
static int register_poll(struct uloop_fd *fd, unsigned int flags)
{
        if (flags & ULOOP_EDGE_TRIGGER)
                flags |= ULOOP_EDGE_DEFER;
        else
                flags &= ~ULOOP_EDGE_DEFER;
 
        return register_kevent(fd, flags);
}
 
static int __uloop_fd_delete(struct uloop_fd *fd)
{
        return register_poll(fd, 0);
}
 
static int64_t get_timestamp_us(void)
{
#ifdef CLOCK_MONOTONIC
        struct timespec ts = { 0, 0 };
 
        clock_gettime(CLOCK_MONOTONIC, &ts);
 
        return ts.tv_sec * 1000000 + ts.tv_nsec / 1000;
#else
        struct timeval tv = { 0, 0 };
 
        gettimeofday(&tv, NULL);
 
        return tv.tv_sec * 1000000 + tv.tv_usec;
#endif
}
 
static int uloop_fetch_events(int timeout)
{
        struct timespec ts;
        int nfds, n;
 
        if (timeout >= 0) {
                ts.tv_sec = timeout / 1000;
                ts.tv_nsec = (timeout % 1000) * 1000000;
        }
 
        nfds = kevent(poll_fd, NULL, 0, events, ARRAY_SIZE(events), timeout >= 0 ? &ts : NULL);
        for (n = 0; n < nfds; n++) {
                if (events[n].filter == EVFILT_TIMER) {
                        struct uloop_interval *tm = events[n].udata;
 
                        tm->priv.time.fired = get_timestamp_us();
                        tm->expirations += events[n].data;
                        tm->cb(tm);
 
                        continue;
                }
 
                struct uloop_fd_event *cur = &cur_fds[n];
                struct uloop_fd *u = events[n].udata;
                unsigned int ev = 0;
 
                cur->fd = u;
                if (!u)
                        continue;
 
                if (events[n].flags & EV_ERROR) {
                        u->error = true;
                        if (!(u->flags & ULOOP_ERROR_CB))
                                uloop_fd_delete(u);
                }
 
                if(events[n].filter == EVFILT_READ)
                        ev |= ULOOP_READ;
                else if (events[n].filter == EVFILT_WRITE)
                        ev |= ULOOP_WRITE;
 
                if (events[n].flags & EV_EOF)
                        u->eof = true;
                else if (!ev)
                        cur->fd = NULL;
 
                cur->events = ev;
                if (u->flags & ULOOP_EDGE_DEFER) {
                        u->flags &= ~ULOOP_EDGE_DEFER;
                        u->flags |= ULOOP_EDGE_TRIGGER;
                        register_kevent(u, u->flags);
                }
        }
        return nfds;
}
 
static int timer_register(struct uloop_interval *tm, unsigned int msecs)
{
        struct kevent ev;
 
        tm->priv.time.msecs = msecs;
        tm->priv.time.fired = get_timestamp_us();
 
        EV_SET(&ev, (uintptr_t)tm, EVFILT_TIMER, EV_ADD, NOTE_USECONDS, msecs * 1000, tm);
 
        return kevent(poll_fd, &ev, 1, NULL, 0, NULL);
}
 
static int timer_remove(struct uloop_interval *tm)
{
        struct kevent ev;
 
        EV_SET(&ev, (uintptr_t)tm, EVFILT_TIMER, EV_DELETE, 0, 0, NULL);
 
        return kevent(poll_fd, &ev, 1, NULL, 0, NULL);
}
 
static int64_t timer_next(struct uloop_interval *tm)
{
        int64_t t1 = tm->priv.time.fired;
        int64_t t2 = get_timestamp_us();
 
        while (t1 < t2)
                t1 += tm->priv.time.msecs * 1000;
 
        return (t1 - t2) / 1000;
}