ladybird/Libraries/LibWebView/EventLoop/EventLoopImplementationQt.cpp
Timothy Flynn 9e1f001ffe LibWebView+Services+UI: Move the EventLoop implementations to LibWebView
We currently compile the Qt event loop files multiple times, for every
target which wants to use them. This patch moves these to LibWebView as
a central location to avoid this.
2024-11-11 07:35:43 -05:00

394 lines
12 KiB
C++

/*
* Copyright (c) 2022-2023, Andreas Kling <andreas@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/IDAllocator.h>
#include <AK/Singleton.h>
#include <AK/TemporaryChange.h>
#include <LibCore/Event.h>
#include <LibCore/EventReceiver.h>
#include <LibCore/Notifier.h>
#include <LibCore/System.h>
#include <LibCore/ThreadEventQueue.h>
#include <LibWebView/EventLoop/EventLoopImplementationQt.h>
#include <LibWebView/EventLoop/EventLoopImplementationQtEventTarget.h>
#include <QCoreApplication>
#include <QEvent>
#include <QEventLoop>
#include <QSocketNotifier>
#include <QTimer>
namespace WebView {
struct ThreadData;
static thread_local ThreadData* s_thread_data;
struct ThreadData {
static ThreadData& the()
{
if (!s_thread_data) {
// FIXME: Don't leak this.
s_thread_data = new ThreadData;
}
return *s_thread_data;
}
HashMap<Core::Notifier*, NonnullOwnPtr<QSocketNotifier>> notifiers;
};
class QtEventLoopManagerEvent final : public QEvent {
public:
static QEvent::Type process_event_queue_event_type()
{
static auto const type = static_cast<QEvent::Type>(QEvent::registerEventType());
return type;
}
QtEventLoopManagerEvent(QEvent::Type type)
: QEvent(type)
{
}
};
class SignalHandlers : public RefCounted<SignalHandlers> {
AK_MAKE_NONCOPYABLE(SignalHandlers);
AK_MAKE_NONMOVABLE(SignalHandlers);
public:
SignalHandlers(int signal_number, void (*handle_signal)(int));
~SignalHandlers();
void dispatch();
int add(Function<void(int)>&& handler);
bool remove(int handler_id);
bool is_empty() const
{
if (m_calling_handlers) {
for (auto const& handler : m_handlers_pending) {
if (handler.value)
return false; // an add is pending
}
}
return m_handlers.is_empty();
}
bool have(int handler_id) const
{
if (m_calling_handlers) {
auto it = m_handlers_pending.find(handler_id);
if (it != m_handlers_pending.end()) {
if (!it->value)
return false; // a deletion is pending
}
}
return m_handlers.contains(handler_id);
}
int m_signal_number;
void (*m_original_handler)(int);
HashMap<int, Function<void(int)>> m_handlers;
HashMap<int, Function<void(int)>> m_handlers_pending;
bool m_calling_handlers { false };
};
SignalHandlers::SignalHandlers(int signal_number, void (*handle_signal)(int))
: m_signal_number(signal_number)
, m_original_handler(signal(signal_number, handle_signal))
{
}
SignalHandlers::~SignalHandlers()
{
(void)::signal(m_signal_number, m_original_handler);
}
struct SignalHandlersInfo {
HashMap<int, NonnullRefPtr<SignalHandlers>> signal_handlers;
int next_signal_id { 0 };
};
static Singleton<SignalHandlersInfo> s_signals;
static SignalHandlersInfo* signals_info()
{
return s_signals.ptr();
}
void SignalHandlers::dispatch()
{
TemporaryChange change(m_calling_handlers, true);
for (auto& handler : m_handlers)
handler.value(m_signal_number);
if (!m_handlers_pending.is_empty()) {
// Apply pending adds/removes
for (auto& handler : m_handlers_pending) {
if (handler.value) {
auto result = m_handlers.set(handler.key, move(handler.value));
VERIFY(result == AK::HashSetResult::InsertedNewEntry);
} else {
m_handlers.remove(handler.key);
}
}
m_handlers_pending.clear();
}
}
int SignalHandlers::add(Function<void(int)>&& handler)
{
int id = ++signals_info()->next_signal_id; // TODO: worry about wrapping and duplicates?
if (m_calling_handlers)
m_handlers_pending.set(id, move(handler));
else
m_handlers.set(id, move(handler));
return id;
}
bool SignalHandlers::remove(int handler_id)
{
VERIFY(handler_id != 0);
if (m_calling_handlers) {
auto it = m_handlers.find(handler_id);
if (it != m_handlers.end()) {
// Mark pending remove
m_handlers_pending.set(handler_id, {});
return true;
}
it = m_handlers_pending.find(handler_id);
if (it != m_handlers_pending.end()) {
if (!it->value)
return false; // already was marked as deleted
it->value = nullptr;
return true;
}
return false;
}
return m_handlers.remove(handler_id);
}
static void dispatch_signal(int signal_number)
{
auto& info = *signals_info();
auto handlers = info.signal_handlers.find(signal_number);
if (handlers != info.signal_handlers.end()) {
// Make sure we bump the ref count while dispatching the handlers!
// This allows a handler to unregister/register while the handlers
// are being called!
auto handler = handlers->value;
handler->dispatch();
}
}
EventLoopImplementationQt::EventLoopImplementationQt()
: m_event_loop(make<QEventLoop>())
{
}
EventLoopImplementationQt::~EventLoopImplementationQt() = default;
int EventLoopImplementationQt::exec()
{
if (is_main_loop())
return QCoreApplication::exec();
return m_event_loop->exec();
}
size_t EventLoopImplementationQt::pump(PumpMode mode)
{
auto result = Core::ThreadEventQueue::current().process();
auto qt_mode = mode == PumpMode::WaitForEvents ? QEventLoop::WaitForMoreEvents : QEventLoop::AllEvents;
if (is_main_loop())
QCoreApplication::processEvents(qt_mode);
else
m_event_loop->processEvents(qt_mode);
result += Core::ThreadEventQueue::current().process();
return result;
}
void EventLoopImplementationQt::quit(int code)
{
if (is_main_loop())
QCoreApplication::exit(code);
else
m_event_loop->exit(code);
}
void EventLoopImplementationQt::wake()
{
if (!is_main_loop())
m_event_loop->wakeUp();
}
void EventLoopImplementationQt::post_event(Core::EventReceiver& receiver, NonnullOwnPtr<Core::Event>&& event)
{
m_thread_event_queue.post_event(receiver, move(event));
if (&m_thread_event_queue != &Core::ThreadEventQueue::current())
wake();
}
void EventLoopImplementationQt::set_main_loop()
{
m_main_loop = true;
auto& event_loop_manager = static_cast<EventLoopManagerQt&>(Core::EventLoopManager::the());
event_loop_manager.set_main_loop_signal_notifiers({});
}
static void qt_timer_fired(Core::TimerShouldFireWhenNotVisible should_fire_when_not_visible, Core::EventReceiver& object)
{
if (should_fire_when_not_visible == Core::TimerShouldFireWhenNotVisible::No) {
if (!object.is_visible_for_timer_purposes())
return;
}
Core::TimerEvent event;
object.dispatch_event(event);
}
intptr_t EventLoopManagerQt::register_timer(Core::EventReceiver& object, int milliseconds, bool should_reload, Core::TimerShouldFireWhenNotVisible should_fire_when_not_visible)
{
auto timer = new QTimer;
timer->setTimerType(Qt::PreciseTimer);
timer->setInterval(milliseconds);
timer->setSingleShot(!should_reload);
auto weak_object = object.make_weak_ptr();
QObject::connect(timer, &QTimer::timeout, [should_fire_when_not_visible, weak_object = move(weak_object)] {
auto object = weak_object.strong_ref();
if (!object)
return;
qt_timer_fired(should_fire_when_not_visible, *object);
});
timer->start();
return bit_cast<intptr_t>(timer);
}
void EventLoopManagerQt::unregister_timer(intptr_t timer_id)
{
auto* timer = bit_cast<QTimer*>(timer_id);
delete timer;
}
static void qt_notifier_activated(Core::Notifier& notifier)
{
Core::NotifierActivationEvent event(notifier.fd(), notifier.type());
notifier.dispatch_event(event);
}
void EventLoopManagerQt::register_notifier(Core::Notifier& notifier)
{
QSocketNotifier::Type type;
switch (notifier.type()) {
case Core::Notifier::Type::Read:
type = QSocketNotifier::Read;
break;
case Core::Notifier::Type::Write:
type = QSocketNotifier::Write;
break;
default:
TODO();
}
auto socket_notifier = make<QSocketNotifier>(notifier.fd(), type);
QObject::connect(socket_notifier, &QSocketNotifier::activated, [&notifier] {
qt_notifier_activated(notifier);
});
ThreadData::the().notifiers.set(&notifier, move(socket_notifier));
}
void EventLoopManagerQt::unregister_notifier(Core::Notifier& notifier)
{
ThreadData::the().notifiers.remove(&notifier);
}
void EventLoopManagerQt::handle_signal(int signal_number)
{
auto& that = static_cast<EventLoopManagerQt&>(Core::EventLoopManager::the());
// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66425
// Apparently warn_unused_result ignoring (void) casts is a feature
[[maybe_unused]] auto _ = ::write(that.m_signal_socket_fds[1], &signal_number, sizeof(signal_number));
}
int EventLoopManagerQt::register_signal(int signal_number, Function<void(int)> handler)
{
VERIFY(signal_number != 0);
auto& info = *signals_info();
auto handlers = info.signal_handlers.find(signal_number);
if (handlers == info.signal_handlers.end()) {
auto signal_handlers = adopt_ref(*new SignalHandlers(signal_number, EventLoopManagerQt::handle_signal));
auto handler_id = signal_handlers->add(move(handler));
info.signal_handlers.set(signal_number, move(signal_handlers));
return handler_id;
} else {
return handlers->value->add(move(handler));
}
}
void EventLoopManagerQt::unregister_signal(int handler_id)
{
VERIFY(handler_id != 0);
int remove_signal_number = 0;
auto& info = *signals_info();
for (auto& h : info.signal_handlers) {
auto& handlers = *h.value;
if (handlers.remove(handler_id)) {
if (handlers.is_empty())
remove_signal_number = handlers.m_signal_number;
break;
}
}
if (remove_signal_number != 0)
info.signal_handlers.remove(remove_signal_number);
}
void EventLoopManagerQt::did_post_event()
{
QCoreApplication::postEvent(m_main_thread_event_target.ptr(), new QtEventLoopManagerEvent(QtEventLoopManagerEvent::process_event_queue_event_type()));
}
bool EventLoopManagerQt::event_target_received_event(Badge<EventLoopImplementationQtEventTarget>, QEvent* event)
{
if (event->type() == QtEventLoopManagerEvent::process_event_queue_event_type()) {
Core::ThreadEventQueue::current().process();
return true;
}
return false;
}
EventLoopManagerQt::EventLoopManagerQt()
: m_main_thread_event_target(make<EventLoopImplementationQtEventTarget>())
{
}
void EventLoopManagerQt::set_main_loop_signal_notifiers(Badge<EventLoopImplementationQt>)
{
MUST(Core::System::socketpair(AF_LOCAL, SOCK_STREAM, 0, m_signal_socket_fds));
m_signal_socket_notifier = new QSocketNotifier(m_signal_socket_fds[0], QSocketNotifier::Read);
QObject::connect(m_signal_socket_notifier, &QSocketNotifier::activated, [this] {
int signal_number = {};
ssize_t nread;
do {
errno = 0;
nread = read(this->m_signal_socket_fds[0], &signal_number, sizeof(signal_number));
if (nread >= 0)
break;
} while (errno == EINTR);
VERIFY(nread == sizeof(signal_number));
dispatch_signal(signal_number);
});
m_signal_socket_notifier->setEnabled(true);
}
EventLoopManagerQt::~EventLoopManagerQt()
{
delete m_signal_socket_notifier;
::close(m_signal_socket_fds[0]);
::close(m_signal_socket_fds[1]);
}
NonnullOwnPtr<Core::EventLoopImplementation> EventLoopManagerQt::make_implementation()
{
return adopt_own(*new EventLoopImplementationQt);
}
}