ladybird/Libraries/LibWeb/HTML/RenderingThread.h
Aliaksandr Kalenik 24e2c402f5 LibWeb+WebContent: Move display list rasterization off the main thread
The display list is an immutable data structure, so once it's created,
rasterization can be moved to a separate thread. This allows more room
for performing other tasks between processing HTML rendering tasks.

This change makes PaintingSurface, ImmutableBitmap, and GlyphRun atomic
ref-counted, as they are shared between the main and rendering threads
by being included in the display list.
2025-03-31 15:58:15 +01:00

52 lines
1.5 KiB
C++

/*
* Copyright (c) 2025, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Noncopyable.h>
#include <AK/Queue.h>
#include <LibThreading/ConditionVariable.h>
#include <LibThreading/Mutex.h>
#include <LibThreading/Thread.h>
#include <LibWeb/Painting/DisplayListPlayerSkia.h>
namespace Web::HTML {
class RenderingThread {
AK_MAKE_NONCOPYABLE(RenderingThread);
AK_MAKE_NONMOVABLE(RenderingThread);
public:
RenderingThread();
~RenderingThread();
void start();
void set_skia_player(OwnPtr<Painting::DisplayListPlayerSkia>&& player) { m_skia_player = move(player); }
void enqueue_rendering_task(RefPtr<Painting::DisplayList>, NonnullRefPtr<Gfx::PaintingSurface>, Function<void()>&& callback);
private:
void rendering_thread_loop();
Core::EventLoop& m_main_thread_event_loop;
OwnPtr<Painting::DisplayListPlayerSkia> m_skia_player;
RefPtr<Threading::Thread> m_thread;
Atomic<bool> m_exit { false };
struct Task {
RefPtr<Painting::DisplayList> display_list;
NonnullRefPtr<Gfx::PaintingSurface> painting_surface;
Function<void()> callback;
};
// NOTE: Queue will only contain multiple items in case tasks were scheduled by screenshot requests.
// Otherwise, it will contain only one item at a time.
Queue<Task> m_rendering_tasks;
Threading::Mutex m_rendering_task_mutex;
Threading::ConditionVariable m_rendering_task_ready_wake_condition { m_rendering_task_mutex };
};
}