ladybird/LibCore/CEventLoop.cpp
2019-04-29 15:57:49 +02:00

283 lines
8 KiB
C++

#include <LibCore/CObject.h>
#include <LibCore/CEventLoop.h>
#include <LibCore/CEvent.h>
#include <LibCore/CLock.h>
#include <LibCore/CNotifier.h>
#include <LibC/unistd.h>
#include <LibC/stdio.h>
#include <LibC/fcntl.h>
#include <LibC/string.h>
#include <LibC/time.h>
#include <LibC/sys/select.h>
#include <LibC/sys/socket.h>
#include <LibC/sys/time.h>
#include <LibC/errno.h>
#include <LibC/string.h>
#include <LibC/stdlib.h>
//#define CEVENTLOOP_DEBUG
//#define DEFERRED_INVOKE_DEBUG
static CEventLoop* s_main_event_loop;
static Vector<CEventLoop*>* s_event_loop_stack;
HashMap<int, OwnPtr<CEventLoop::EventLoopTimer>>* CEventLoop::s_timers;
HashTable<CNotifier*>* CEventLoop::s_notifiers;
int CEventLoop::s_next_timer_id = 1;
CEventLoop::CEventLoop()
{
if (!s_event_loop_stack) {
s_event_loop_stack = new Vector<CEventLoop*>;
s_timers = new HashMap<int, OwnPtr<CEventLoop::EventLoopTimer>>;
s_notifiers = new HashTable<CNotifier*>;
}
if (!s_main_event_loop) {
s_main_event_loop = this;
s_event_loop_stack->append(this);
}
#ifdef CEVENTLOOP_DEBUG
dbgprintf("(%u) CEventLoop constructed :)\n", getpid());
#endif
}
CEventLoop::~CEventLoop()
{
}
CEventLoop& CEventLoop::main()
{
ASSERT(s_main_event_loop);
return *s_main_event_loop;
}
CEventLoop& CEventLoop::current()
{
return *s_event_loop_stack->last();
}
void CEventLoop::quit(int code)
{
m_exit_requested = true;
m_exit_code = code;
}
struct CEventLoopPusher {
public:
CEventLoopPusher(CEventLoop& event_loop) : m_event_loop(event_loop)
{
if (&m_event_loop != s_main_event_loop) {
m_event_loop.take_pending_events_from(CEventLoop::current());
s_event_loop_stack->append(&event_loop);
}
}
~CEventLoopPusher()
{
if (&m_event_loop != s_main_event_loop) {
s_event_loop_stack->take_last();
CEventLoop::current().take_pending_events_from(m_event_loop);
}
}
private:
CEventLoop& m_event_loop;
};
int CEventLoop::exec()
{
CEventLoopPusher pusher(*this);
m_running = true;
for (;;) {
if (m_exit_requested)
return m_exit_code;
do_processing();
if (m_queued_events.is_empty()) {
wait_for_event();
do_processing();
}
decltype(m_queued_events) events;
{
LOCKER(m_lock);
events = move(m_queued_events);
}
for (auto& queued_event : events) {
auto* receiver = queued_event.receiver.ptr();
auto& event = *queued_event.event;
#ifdef CEVENTLOOP_DEBUG
dbgprintf("CEventLoop: %s{%p} event %u\n", receiver->class_name(), receiver, (unsigned)event.type());
#endif
if (!receiver) {
switch (event.type()) {
case CEvent::Quit:
ASSERT_NOT_REACHED();
return 0;
default:
dbgprintf("Event type %u with no receiver :(\n", event.type());
}
} else if (event.type() == CEvent::Type::DeferredInvoke) {
#ifdef DEFERRED_INVOKE_DEBUG
printf("DeferredInvoke: receiver=%s{%p}\n", receiver->class_name(), receiver);
#endif
static_cast<CDeferredInvocationEvent&>(event).m_invokee(*receiver);
} else {
receiver->event(event);
}
if (m_exit_requested) {
LOCKER(m_lock);
auto rejigged_event_queue = move(events);
rejigged_event_queue.append(move(m_queued_events));
m_queued_events = move(rejigged_event_queue);
return m_exit_code;
}
}
}
ASSERT_NOT_REACHED();
}
void CEventLoop::post_event(CObject& receiver, OwnPtr<CEvent>&& event)
{
LOCKER(m_lock);
#ifdef CEVENTLOOP_DEBUG
dbgprintf("CEventLoop::post_event: {%u} << receiver=%p, event=%p\n", m_queued_events.size(), &receiver, event.ptr());
#endif
m_queued_events.append({ receiver.make_weak_ptr(), move(event) });
}
void CEventLoop::wait_for_event()
{
fd_set rfds;
fd_set wfds;
FD_ZERO(&rfds);
FD_ZERO(&wfds);
int max_fd = 0;
auto add_fd_to_set = [&max_fd] (int fd, fd_set& set){
FD_SET(fd, &set);
if (fd > max_fd)
max_fd = fd;
};
int max_fd_added = -1;
add_file_descriptors_for_select(rfds, max_fd_added);
max_fd = max(max_fd, max_fd_added);
for (auto& notifier : *s_notifiers) {
if (notifier->event_mask() & CNotifier::Read)
add_fd_to_set(notifier->fd(), rfds);
if (notifier->event_mask() & CNotifier::Write)
add_fd_to_set(notifier->fd(), wfds);
if (notifier->event_mask() & CNotifier::Exceptional)
ASSERT_NOT_REACHED();
}
bool queued_events_is_empty;
{
LOCKER(m_lock);
queued_events_is_empty = m_queued_events.is_empty();
}
struct timeval timeout = { 0, 0 };
if (!s_timers->is_empty() && queued_events_is_empty)
get_next_timer_expiration(timeout);
int rc = select(max_fd + 1, &rfds, &wfds, nullptr, (queued_events_is_empty && s_timers->is_empty()) ? nullptr : &timeout);
if (rc < 0) {
ASSERT_NOT_REACHED();
}
timeval now;
if (!s_timers->is_empty())
gettimeofday(&now, nullptr);
for (auto& it : *s_timers) {
auto& timer = *it.value;
if (!timer.has_expired(now))
continue;
#ifdef CEVENTLOOP_DEBUG
dbgprintf("CEventLoop: Timer %d has expired, sending CTimerEvent to %p\n", timer.timer_id, timer.owner);
#endif
post_event(*timer.owner, make<CTimerEvent>(timer.timer_id));
if (timer.should_reload) {
timer.reload(now);
} else {
// FIXME: Support removing expired timers that don't want to reload.
ASSERT_NOT_REACHED();
}
}
for (auto& notifier : *s_notifiers) {
if (FD_ISSET(notifier->fd(), &rfds)) {
if (notifier->on_ready_to_read)
notifier->on_ready_to_read();
}
if (FD_ISSET(notifier->fd(), &wfds)) {
if (notifier->on_ready_to_write)
notifier->on_ready_to_write();
}
}
process_file_descriptors_after_select(rfds);
}
bool CEventLoop::EventLoopTimer::has_expired(const timeval& now) const
{
return now.tv_sec > fire_time.tv_sec || (now.tv_sec == fire_time.tv_sec && now.tv_usec >= fire_time.tv_usec);
}
void CEventLoop::EventLoopTimer::reload(const timeval& now)
{
fire_time = now;
fire_time.tv_sec += interval / 1000;
fire_time.tv_usec += (interval % 1000) * 1000;
}
void CEventLoop::get_next_timer_expiration(timeval& soonest)
{
ASSERT(!s_timers->is_empty());
bool has_checked_any = false;
for (auto& it : *s_timers) {
auto& fire_time = it.value->fire_time;
if (!has_checked_any || fire_time.tv_sec < soonest.tv_sec || (fire_time.tv_sec == soonest.tv_sec && fire_time.tv_usec < soonest.tv_usec))
soonest = fire_time;
has_checked_any = true;
}
}
int CEventLoop::register_timer(CObject& object, int milliseconds, bool should_reload)
{
ASSERT(milliseconds >= 0);
auto timer = make<EventLoopTimer>();
timer->owner = object.make_weak_ptr();
timer->interval = milliseconds;
timeval now;
gettimeofday(&now, nullptr);
timer->reload(now);
timer->should_reload = should_reload;
int timer_id = ++s_next_timer_id; // FIXME: This will eventually wrap around.
ASSERT(timer_id); // FIXME: Aforementioned wraparound.
timer->timer_id = timer_id;
s_timers->set(timer->timer_id, move(timer));
return timer_id;
}
bool CEventLoop::unregister_timer(int timer_id)
{
auto it = s_timers->find(timer_id);
if (it == s_timers->end())
return false;
s_timers->remove(it);
return true;
}
void CEventLoop::register_notifier(Badge<CNotifier>, CNotifier& notifier)
{
s_notifiers->set(&notifier);
}
void CEventLoop::unregister_notifier(Badge<CNotifier>, CNotifier& notifier)
{
s_notifiers->remove(&notifier);
}