/* Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include "apr.h"

#include "apr_poll.h"

#include "apr_time.h"

#include "apr_portable.h"

#include "apr_arch_file_io.h"

#include "apr_arch_networkio.h"

#include "apr_arch_poll_private.h"

#include "apr_arch_inherit.h"

#if defined(HAVE_EPOLL)

static unsigned get_epoll_event(apr_int16_t event)

{

    unsigned rv = 0;

    if (event & APR_POLLIN)

        rv |= EPOLLIN;

    if (event & APR_POLLPRI)

        rv |= EPOLLPRI;

    if (event & APR_POLLOUT)

        rv |= EPOLLOUT;

#ifdef EPOLLEXCLUSIVE

    if (event & APR_POLLEXCL)

        rv |= EPOLLEXCLUSIVE;

#endif

    /* APR_POLLNVAL is not handled by epoll.  EPOLLERR and EPOLLHUP are return-only */

    return rv;

}

static apr_int16_t get_epoll_revent(unsigned event)

{

    apr_int16_t rv = 0;

    if (event & EPOLLIN)

        rv |= APR_POLLIN;

    if (event & EPOLLPRI)

        rv |= APR_POLLPRI;

    if (event & EPOLLOUT)

        rv |= APR_POLLOUT;

    if (event & EPOLLERR)

        rv |= APR_POLLERR;

    if (event & EPOLLHUP)

        rv |= APR_POLLHUP;

    /* APR_POLLNVAL is not handled by epoll. */

    return rv;

}

struct apr_pollset_private_t

{

    int epoll_fd;

    struct epoll_event *pollset;

    apr_pollfd_t *result_set;

#if APR_HAS_THREADS

    /* A thread mutex to protect operations on the rings */

    apr_thread_mutex_t *ring_lock;

#endif

    /* A ring containing all of the pollfd_t that are active */

    APR_RING_HEAD(pfd_query_ring_t, pfd_elem_t) query_ring;

    /* A ring of pollfd_t that have been used, and then _remove()'d */

    APR_RING_HEAD(pfd_free_ring_t, pfd_elem_t) free_ring;

    /* A ring of pollfd_t where rings that have been _remove()`ed but

        might still be inside a _poll() */

    APR_RING_HEAD(pfd_dead_ring_t, pfd_elem_t) dead_ring;

};

static apr_status_t impl_pollset_cleanup(apr_pollset_t *pollset)

{

    close(pollset->p->epoll_fd);

    return APR_SUCCESS;

}

static apr_status_t impl_pollset_create(apr_pollset_t *pollset,

                                        apr_uint32_t size,

                                        apr_pool_t *p,

                                        apr_uint32_t flags)

{

    apr_status_t rv;

    int fd;

#ifdef HAVE_EPOLL_CREATE1

    fd = epoll_create1(EPOLL_CLOEXEC);

#else

    fd = epoll_create(size);

#endif

    if (fd < 0) {

        pollset->p = NULL;

        return apr_get_netos_error();

    }

#ifndef HAVE_EPOLL_CREATE1

    {

        int fd_flags;

        if ((fd_flags = fcntl(fd, F_GETFD)) == -1) {

            rv = errno;

            close(fd);

            pollset->p = NULL;

            return rv;

        }

        fd_flags |= FD_CLOEXEC;

        if (fcntl(fd, F_SETFD, fd_flags) == -1) {

            rv = errno;

            close(fd);

            pollset->p = NULL;

            return rv;

        }

    }

#endif

    pollset->p = apr_pcalloc(p, sizeof(apr_pollset_private_t));

#if APR_HAS_THREADS

    if ((flags & APR_POLLSET_THREADSAFE) &&

        !(flags & APR_POLLSET_NOCOPY) &&

        ((rv = apr_thread_mutex_create(&pollset->p->ring_lock,

                                       APR_THREAD_MUTEX_DEFAULT,

                                       p)) != APR_SUCCESS)) {

        close(fd);

        pollset->p = NULL;

        return rv;

    }

#else

    if (flags & APR_POLLSET_THREADSAFE) {

        close(fd);

        pollset->p = NULL;

        return APR_ENOTIMPL;

    }

#endif

    pollset->p->epoll_fd = fd;

    pollset->p->pollset = apr_palloc(p, size * sizeof(struct epoll_event));

    pollset->p->result_set = apr_palloc(p, size * sizeof(apr_pollfd_t));

    if (!(flags & APR_POLLSET_NOCOPY)) {

        APR_RING_INIT(&pollset->p->query_ring, pfd_elem_t, link);

        APR_RING_INIT(&pollset->p->free_ring, pfd_elem_t, link);

        APR_RING_INIT(&pollset->p->dead_ring, pfd_elem_t, link);

    }

    return APR_SUCCESS;

}

static apr_status_t impl_pollset_add(apr_pollset_t *pollset,

                                     const apr_pollfd_t *descriptor)

{

    struct epoll_event ev = {0};

    int ret;

    pfd_elem_t *elem = NULL;

    apr_status_t rv = APR_SUCCESS;

    ev.events = get_epoll_event(descriptor->reqevents);

    if (pollset->flags & APR_POLLSET_NOCOPY) {

        ev.data.ptr = (void *)descriptor;

    }

    else {

        pollset_lock_rings();

        if (!APR_RING_EMPTY(&(pollset->p->free_ring), pfd_elem_t, link)) {

            elem = APR_RING_FIRST(&(pollset->p->free_ring));

            APR_RING_REMOVE(elem, link);

        }

        else {

            elem = (pfd_elem_t *) apr_palloc(pollset->pool, sizeof(pfd_elem_t));

            APR_RING_ELEM_INIT(elem, link);

        }

        elem->pfd = *descriptor;

        ev.data.ptr = elem;

    }

    if (descriptor->desc_type == APR_POLL_SOCKET) {

        ret = epoll_ctl(pollset->p->epoll_fd, EPOLL_CTL_ADD,

                        descriptor->desc.s->socketdes, &ev);

    }

    else {

        ret = epoll_ctl(pollset->p->epoll_fd, EPOLL_CTL_ADD,

                        descriptor->desc.f->filedes, &ev);

    }

    if (0 != ret) {

        rv = apr_get_netos_error();

    }

    if (!(pollset->flags & APR_POLLSET_NOCOPY)) {

        if (rv != APR_SUCCESS) {

            APR_RING_INSERT_TAIL(&(pollset->p->free_ring), elem, pfd_elem_t, link);

        }

        else {

            APR_RING_INSERT_TAIL(&(pollset->p->query_ring), elem, pfd_elem_t, link);

        }

        pollset_unlock_rings();

    }

    return rv;

}

static apr_status_t impl_pollset_remove(apr_pollset_t *pollset,

                                        const apr_pollfd_t *descriptor)

{

    pfd_elem_t *ep;

    apr_status_t rv = APR_SUCCESS;

    struct epoll_event ev = {0}; /* ignored, but must be passed with

                                  * kernel < 2.6.9

                                  */

    int ret;

    if (descriptor->desc_type == APR_POLL_SOCKET) {

        ret = epoll_ctl(pollset->p->epoll_fd, EPOLL_CTL_DEL,

                        descriptor->desc.s->socketdes, &ev);

    }

    else {

        ret = epoll_ctl(pollset->p->epoll_fd, EPOLL_CTL_DEL,

                        descriptor->desc.f->filedes, &ev);

    }

    if (ret < 0) {

        rv = APR_NOTFOUND;

    }

    if (!(pollset->flags & APR_POLLSET_NOCOPY)) {

        pollset_lock_rings();

        for (ep = APR_RING_FIRST(&(pollset->p->query_ring));

             ep != APR_RING_SENTINEL(&(pollset->p->query_ring),

                                     pfd_elem_t, link);

             ep = APR_RING_NEXT(ep, link)) {

            if (descriptor->desc.s == ep->pfd.desc.s) {

                APR_RING_REMOVE(ep, link);

                APR_RING_INSERT_TAIL(&(pollset->p->dead_ring),

                                     ep, pfd_elem_t, link);

                break;

            }

        }

        pollset_unlock_rings();

    }

    return rv;

}

static apr_status_t impl_pollset_poll(apr_pollset_t *pollset,

                                           apr_interval_time_t timeout,

                                           apr_int32_t *num,

                                           const apr_pollfd_t **descriptors)

{

    int ret;

    apr_status_t rv = APR_SUCCESS;

    *num = 0;

    if (timeout > 0) {

        timeout = (timeout + 999) / 1000;

    }

    ret = epoll_wait(pollset->p->epoll_fd, pollset->p->pollset, pollset->nalloc,

                     timeout);

    if (ret < 0) {

        rv = apr_get_netos_error();

    }

    else if (ret == 0) {

        rv = APR_TIMEUP;

    }

    else {

        int i, j;

        const apr_pollfd_t *fdptr;

        for (i = 0, j = 0; i < ret; i++) {

            if (pollset->flags & APR_POLLSET_NOCOPY) {

                fdptr = (apr_pollfd_t *)(pollset->p->pollset[i].data.ptr);

            }

            else {

                fdptr = &(((pfd_elem_t *) (pollset->p->pollset[i].data.ptr))->pfd);

            }

            /* Check if the polled descriptor is our

             * wakeup pipe. In that case do not put it result set.

             */

            if ((pollset->flags & APR_POLLSET_WAKEABLE) &&

                fdptr->desc_type == APR_POLL_FILE &&

                fdptr->desc.f == pollset->wakeup_pipe[0]) {

                apr_poll_drain_wakeup_pipe(&pollset->wakeup_set, pollset->wakeup_pipe);

                rv = APR_EINTR;

            }

            else {

                pollset->p->result_set[j] = *fdptr;

                pollset->p->result_set[j].rtnevents =

                    get_epoll_revent(pollset->p->pollset[i].events);

                j++;

            }

        }

        if (((*num) = j)) { /* any event besides wakeup pipe? */

            rv = APR_SUCCESS;

            if (descriptors) {

                *descriptors = pollset->p->result_set;

            }

        }

    }

    if (!(pollset->flags & APR_POLLSET_NOCOPY)) {

        pollset_lock_rings();

        /* Shift all PFDs in the Dead Ring to the Free Ring */

        APR_RING_CONCAT(&(pollset->p->free_ring), &(pollset->p->dead_ring), pfd_elem_t, link);

        pollset_unlock_rings();

    }

    return rv;

}

static const apr_pollset_provider_t impl = {

    impl_pollset_create,

    impl_pollset_add,

    impl_pollset_remove,

    impl_pollset_poll,

    impl_pollset_cleanup,

    "epoll"

};

const apr_pollset_provider_t *const apr_pollset_provider_epoll = &impl;

static apr_status_t impl_pollcb_cleanup(apr_pollcb_t *pollcb)

{

    close(pollcb->fd);

    return APR_SUCCESS;

}

static apr_status_t impl_pollcb_create(apr_pollcb_t *pollcb,

                                       apr_uint32_t size,

                                       apr_pool_t *p,

                                       apr_uint32_t flags)

{

    int fd;

#ifdef HAVE_EPOLL_CREATE1

    fd = epoll_create1(EPOLL_CLOEXEC);

#else

    fd = epoll_create(size);

#endif

    if (fd < 0) {

        return apr_get_netos_error();

    }

#ifndef HAVE_EPOLL_CREATE1

    {

        int fd_flags;

        apr_status_t rv;

        if ((fd_flags = fcntl(fd, F_GETFD)) == -1) {

            rv = errno;

            close(fd);

            pollcb->fd = -1;

            return rv;

        }

        fd_flags |= FD_CLOEXEC;

        if (fcntl(fd, F_SETFD, fd_flags) == -1) {

            rv = errno;

            close(fd);

            pollcb->fd = -1;

            return rv;

        }

    }

#endif

    pollcb->fd = fd;

    pollcb->pollset.epoll = apr_palloc(p, size * sizeof(struct epoll_event));

    return APR_SUCCESS;

}

static apr_status_t impl_pollcb_add(apr_pollcb_t *pollcb,

                                    apr_pollfd_t *descriptor)

{

    struct epoll_event ev = { 0 };

    int ret;

    ev.events = get_epoll_event(descriptor->reqevents);

    ev.data.ptr = (void *) descriptor;

    if (descriptor->desc_type == APR_POLL_SOCKET) {

        ret = epoll_ctl(pollcb->fd, EPOLL_CTL_ADD,

                        descriptor->desc.s->socketdes, &ev);

    }

    else {

        ret = epoll_ctl(pollcb->fd, EPOLL_CTL_ADD,

                        descriptor->desc.f->filedes, &ev);

    }

    if (ret == -1) {

        return apr_get_netos_error();

    }

    return APR_SUCCESS;

}

static apr_status_t impl_pollcb_remove(apr_pollcb_t *pollcb,

                                       apr_pollfd_t *descriptor)

{

    apr_status_t rv = APR_SUCCESS;

    struct epoll_event ev = {0}; /* ignored, but must be passed with

                                  * kernel < 2.6.9

                                  */

    int ret;

    if (descriptor->desc_type == APR_POLL_SOCKET) {

        ret = epoll_ctl(pollcb->fd, EPOLL_CTL_DEL,

                        descriptor->desc.s->socketdes, &ev);

    }

    else {

        ret = epoll_ctl(pollcb->fd, EPOLL_CTL_DEL,

                        descriptor->desc.f->filedes, &ev);

    }

    if (ret < 0) {

        rv = APR_NOTFOUND;

    }

    return rv;

}

static apr_status_t impl_pollcb_poll(apr_pollcb_t *pollcb,

                                     apr_interval_time_t timeout,

                                     apr_pollcb_cb_t func,

                                     void *baton)

{

    int ret, i;

    apr_status_t rv = APR_SUCCESS;

    if (timeout > 0) {

        timeout = (timeout + 999) / 1000;

    }

    ret = epoll_wait(pollcb->fd, pollcb->pollset.epoll, pollcb->nalloc,

                     timeout);

    if (ret < 0) {

        rv = apr_get_netos_error();

    }

    else if (ret == 0) {

        rv = APR_TIMEUP;

    }

    else {

        for (i = 0; i < ret; i++) {

            apr_pollfd_t *pollfd = (apr_pollfd_t *)(pollcb->pollset.epoll[i].data.ptr);

            if ((pollcb->flags & APR_POLLSET_WAKEABLE) &&

                pollfd->desc_type == APR_POLL_FILE &&

                pollfd->desc.f == pollcb->wakeup_pipe[0]) {

                apr_poll_drain_wakeup_pipe(&pollcb->wakeup_set, pollcb->wakeup_pipe);

                return APR_EINTR;

            }

            pollfd->rtnevents = get_epoll_revent(pollcb->pollset.epoll[i].events);

            rv = func(baton, pollfd);

            if (rv) {

                return rv;

            }

        }

    }

    return rv;

}

static const apr_pollcb_provider_t impl_cb = {

    impl_pollcb_create,

    impl_pollcb_add,

    impl_pollcb_remove,

    impl_pollcb_poll,

    impl_pollcb_cleanup,

    "epoll"

};

const apr_pollcb_provider_t *const apr_pollcb_provider_epoll = &impl_cb;

#endif /* HAVE_EPOLL */