LookingGlass/client/displayservers/Wayland/poll.c

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/*
Looking Glass - KVM FrameRelay (KVMFR) Client
Copyright (C) 2021 Guanzhong Chen (quantum2048@gmail.com)
Copyright (C) 2021 Tudor Brindus (contact@tbrindus.ca)
https://looking-glass.io
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 2 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, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "wayland.h"
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <sys/epoll.h>
#include <wayland-client.h>
#include "common/debug.h"
#include "common/locking.h"
#define EPOLL_EVENTS 10 // Maximum number of fds we can process at once in waylandWait
static void waylandDisplayCallback(uint32_t events, void * opaque)
{
if (events & EPOLLERR)
wl_display_cancel_read(wlWm.display);
else
wl_display_read_events(wlWm.display);
wl_display_dispatch_pending(wlWm.display);
}
bool waylandPollInit(void)
{
wlWm.epollFd = epoll_create1(EPOLL_CLOEXEC);
if (wlWm.epollFd < 0)
{
DEBUG_ERROR("Failed to initialize epoll: %s", strerror(errno));
return false;
}
wl_list_init(&wlWm.poll);
wl_list_init(&wlWm.pollFree);
LG_LOCK_INIT(wlWm.pollLock);
LG_LOCK_INIT(wlWm.pollFreeLock);
wlWm.displayFd = wl_display_get_fd(wlWm.display);
if (!waylandEpollRegister(wlWm.displayFd, waylandDisplayCallback, NULL, EPOLLIN))
{
DEBUG_ERROR("Failed register display to epoll: %s", strerror(errno));
return false;
}
return true;
}
void waylandWait(unsigned int time)
{
while (wl_display_prepare_read(wlWm.display))
wl_display_dispatch_pending(wlWm.display);
wl_display_flush(wlWm.display);
struct epoll_event events[EPOLL_EVENTS];
int count;
if ((count = epoll_wait(wlWm.epollFd, events, EPOLL_EVENTS, time)) < 0)
{
if (errno != EINTR)
DEBUG_INFO("epoll failed: %s", strerror(errno));
wl_display_cancel_read(wlWm.display);
return;
}
bool sawDisplay = false;
for (int i = 0; i < count; ++i) {
struct WaylandPoll * poll = events[i].data.ptr;
if (!poll->removed)
poll->callback(events[i].events, poll->opaque);
if (poll->fd == wlWm.displayFd)
sawDisplay = true;
}
if (!sawDisplay)
wl_display_cancel_read(wlWm.display);
INTERLOCKED_SECTION(wlWm.pollFreeLock,
{
struct WaylandPoll * node;
struct WaylandPoll * temp;
wl_list_for_each_safe(node, temp, &wlWm.pollFree, link)
{
wl_list_remove(&node->link);
free(node);
}
});
}
static void waylandEpollRemoveNode(struct WaylandPoll * node)
{
INTERLOCKED_SECTION(wlWm.pollLock,
{
wl_list_remove(&node->link);
});
}
bool waylandEpollRegister(int fd, WaylandPollCallback callback, void * opaque, uint32_t events)
{
struct WaylandPoll * node = malloc(sizeof(struct WaylandPoll));
if (!node)
return false;
node->fd = fd;
node->removed = false;
node->callback = callback;
node->opaque = opaque;
INTERLOCKED_SECTION(wlWm.pollLock,
{
wl_list_insert(&wlWm.poll, &node->link);
});
if (epoll_ctl(wlWm.epollFd, EPOLL_CTL_ADD, fd, &(struct epoll_event) {
.events = events,
.data = (epoll_data_t) { .ptr = node },
}) < 0)
{
waylandEpollRemoveNode(node);
free(node);
return false;
}
return true;
}
bool waylandEpollUnregister(int fd)
{
struct WaylandPoll * node = NULL;
INTERLOCKED_SECTION(wlWm.pollLock,
{
wl_list_for_each(node, &wlWm.poll, link)
{
if (node->fd == fd)
break;
}
});
if (!node)
{
DEBUG_ERROR("Attempt to unregister a fd that was not registered: %d", fd);
return false;
}
node->removed = true;
if (epoll_ctl(wlWm.epollFd, EPOLL_CTL_DEL, fd, NULL) < 0)
{
DEBUG_ERROR("Failed to unregistered from epoll: %s", strerror(errno));
return false;
}
waylandEpollRemoveNode(node);
INTERLOCKED_SECTION(wlWm.pollFreeLock,
{
wl_list_insert(&wlWm.pollFree, &node->link);
});
return true;
}