uloop-epoll.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.
 */
 
#ifndef EPOLLRDHUP
#define EPOLLRDHUP 0x2000
#endif
 
static int uloop_init_pollfd(void)
{
        if (poll_fd >= 0)
                return 0;
 
        poll_fd = epoll_create(32);
        if (poll_fd < 0)
                return -1;
 
        fcntl(poll_fd, F_SETFD, fcntl(poll_fd, F_GETFD) | FD_CLOEXEC);
        return 0;
}
 
static int register_poll(struct uloop_fd *fd, unsigned int flags)
{
        struct epoll_event ev;
        int op = fd->registered ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
 
        memset(&ev, 0, sizeof(struct epoll_event));
 
        if (flags & ULOOP_READ)
                ev.events |= EPOLLIN | EPOLLRDHUP;
 
        if (flags & ULOOP_WRITE)
                ev.events |= EPOLLOUT;
 
        if (flags & ULOOP_EDGE_TRIGGER)
                ev.events |= EPOLLET;
 
        ev.data.ptr = fd;
 
        return epoll_ctl(poll_fd, op, fd->fd, &ev);
}
 
static struct epoll_event events[ULOOP_MAX_EVENTS];
 
static int __uloop_fd_delete(struct uloop_fd *sock)
{
        sock->flags = 0;
        return epoll_ctl(poll_fd, EPOLL_CTL_DEL, sock->fd, 0);
}
 
static int uloop_fetch_events(int timeout)
{
        int n, nfds;
 
        nfds = epoll_wait(poll_fd, events, ARRAY_SIZE(events), timeout);
        for (n = 0; n < nfds; ++n) {
                struct uloop_fd_event *cur = &cur_fds[n];
                struct uloop_fd *u = events[n].data.ptr;
                unsigned int ev = 0;
 
                cur->fd = u;
                if (!u)
                        continue;
 
                if (events[n].events & (EPOLLERR|EPOLLHUP)) {
                        u->error = true;
                        if (!(u->flags & ULOOP_ERROR_CB))
                                uloop_fd_delete(u);
                }
 
                if(!(events[n].events & (EPOLLRDHUP|EPOLLIN|EPOLLOUT|EPOLLERR|EPOLLHUP))) {
                        cur->fd = NULL;
                        continue;
                }
 
                if(events[n].events & EPOLLRDHUP)
                        u->eof = true;
 
                if(events[n].events & EPOLLIN)
                        ev |= ULOOP_READ;
 
                if(events[n].events & EPOLLOUT)
                        ev |= ULOOP_WRITE;
 
                cur->events = ev;
        }
 
        return nfds;
}
 
static void dispatch_timer(struct uloop_fd *u, unsigned int events)
{
        if (!(events & ULOOP_READ))
                return;
 
        uint64_t fired;
 
        if (read(u->fd, &fired, sizeof(fired)) != sizeof(fired))
                return;
 
        struct uloop_interval *tm = container_of(u, struct uloop_interval, priv.ufd);
 
        tm->expirations += fired;
        tm->cb(tm);
}
 
static int timer_register(struct uloop_interval *tm, unsigned int msecs)
{
        if (!tm->priv.ufd.registered) {
                int fd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC|TFD_NONBLOCK);
 
                if (fd == -1)
                        return -1;
 
                tm->priv.ufd.fd = fd;
                tm->priv.ufd.cb = dispatch_timer;
        }
 
        struct itimerspec spec = {
                .it_value = {
                        .tv_sec = msecs / 1000,
                        .tv_nsec = (msecs % 1000) * 1000000
                },
                .it_interval = {
                        .tv_sec = msecs / 1000,
                        .tv_nsec = (msecs % 1000) * 1000000
                }
        };
 
        if (timerfd_settime(tm->priv.ufd.fd, 0, &spec, NULL) == -1)
                goto err;
 
        if (uloop_fd_add(&tm->priv.ufd, ULOOP_READ) == -1)
                goto err;
 
        return 0;
 
err:
        uloop_fd_delete(&tm->priv.ufd);
        close(tm->priv.ufd.fd);
        memset(&tm->priv.ufd, 0, sizeof(tm->priv.ufd));
 
        return -1;
}
 
static int timer_remove(struct uloop_interval *tm)
{
        int ret = __uloop_fd_delete(&tm->priv.ufd);
 
        if (ret == 0) {
                close(tm->priv.ufd.fd);
                memset(&tm->priv.ufd, 0, sizeof(tm->priv.ufd));
        }
 
        return ret;
}
 
static int64_t timer_next(struct uloop_interval *tm)
{
        struct itimerspec spec;
 
        if (!tm->priv.ufd.registered)
                return -1;
 
        if (timerfd_gettime(tm->priv.ufd.fd, &spec) == -1)
                return -1;
 
        return spec.it_value.tv_sec * 1000 + spec.it_value.tv_nsec / 1000000;
}