LibGfx+LibWeb: Move Skia backend context to process level singleton

Previously, this was attached to the traversable navigable. Using a
singleton instead allows us to use the context for detached documents.

Libraries/LibGfx/PaintingSurface.cpp

@@ -94,12 +94,13 @@ NonnullRefPtr<PaintingSurface> PaintingSurface::create_from_vkimage(NonnullRefPt
 }
 #endif
 
-NonnullRefPtr<PaintingSurface> PaintingSurface::create_with_size(RefPtr<SkiaBackendContext> context, IntSize size, BitmapFormat color_type, AlphaType alpha_type)
+NonnullRefPtr<PaintingSurface> PaintingSurface::create_with_size(IntSize size, BitmapFormat color_type, AlphaType alpha_type)
 {
     auto sk_color_type = to_skia_color_type(color_type);
     auto sk_alpha_type = to_skia_alpha_type(color_type, alpha_type);
     auto image_info = SkImageInfo::Make(size.width(), size.height(), sk_color_type, sk_alpha_type, SkColorSpace::MakeSRGB());
 
+    auto context = SkiaBackendContext::the();
     if (context) {
         context->lock();
         auto surface = SkSurfaces::RenderTarget(context->sk_context(), skgpu::Budgeted::kNo, image_info);

Libraries/LibGfx/PaintingSurface.h

@@ -32,7 +32,7 @@ public:
 
     Function<void(PaintingSurface&)> on_flush;
 
-    static NonnullRefPtr<PaintingSurface> create_with_size(RefPtr<SkiaBackendContext> context, IntSize size, BitmapFormat color_type, AlphaType alpha_type);
+    static NonnullRefPtr<PaintingSurface> create_with_size(IntSize size, BitmapFormat color_type, AlphaType alpha_type);
     static NonnullRefPtr<PaintingSurface> wrap_bitmap(Bitmap&);
 
 #ifdef AK_OS_MACOS

Libraries/LibGfx/SkiaBackendContext.cpp

@@ -27,6 +27,31 @@
 
 namespace Gfx {
 
+static RefPtr<SkiaBackendContext> s_the;
+
+void SkiaBackendContext::initialize_gpu_backend()
+{
+    VERIFY(!s_the);
+
+#ifdef AK_OS_MACOS
+    auto metal_context = get_metal_context();
+    s_the = create_metal_context(*metal_context);
+#elif USE_VULKAN
+    auto maybe_vulkan_context = Gfx::create_vulkan_context();
+    if (maybe_vulkan_context.is_error()) {
+        dbgln("Vulkan context creation failed: {}", maybe_vulkan_context.error());
+        return;
+    }
+    auto vulkan_context = maybe_vulkan_context.release_value();
+    s_the = create_vulkan_context(vulkan_context);
+#endif
+}
+
+RefPtr<SkiaBackendContext> SkiaBackendContext::the()
+{
+    return s_the;
+}
+
 #ifdef USE_VULKAN
 class SkiaVulkanBackendContext final : public SkiaBackendContext {
     AK_MAKE_NONCOPYABLE(SkiaVulkanBackendContext);

Libraries/LibGfx/SkiaBackendContext.h

@@ -39,6 +39,9 @@ public:
     static RefPtr<SkiaBackendContext> create_metal_context(NonnullRefPtr<MetalContext>);
 #endif
 
+    static void initialize_gpu_backend();
+    static RefPtr<SkiaBackendContext> the();
+
     SkiaBackendContext() { }
     virtual ~SkiaBackendContext() { }
 

Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp

@@ -34,7 +34,6 @@
 #include <LibWeb/HTML/ImageRequest.h>
 #include <LibWeb/HTML/Path2D.h>
 #include <LibWeb/HTML/TextMetrics.h>
-#include <LibWeb/HTML/TraversableNavigable.h>
 #include <LibWeb/Infra/CharacterTypes.h>
 #include <LibWeb/Layout/TextNode.h>
 #include <LibWeb/Painting/Paintable.h>
@@ -248,8 +247,7 @@ void CanvasRenderingContext2D::allocate_painting_surface_if_needed()
 
     auto color_type = m_context_attributes.alpha ? Gfx::BitmapFormat::BGRA8888 : Gfx::BitmapFormat::BGRx8888;
 
-    auto skia_backend_context = canvas_element().navigable()->traversable_navigable()->skia_backend_context();
-    m_surface = Gfx::PaintingSurface::create_with_size(skia_backend_context, canvas_element().bitmap_size_for_canvas(), color_type, Gfx::AlphaType::Premultiplied);
+    m_surface = Gfx::PaintingSurface::create_with_size(canvas_element().bitmap_size_for_canvas(), color_type, Gfx::AlphaType::Premultiplied);
     m_painter = nullptr;
 
     // https://html.spec.whatwg.org/multipage/canvas.html#the-canvas-settings:concept-canvas-alpha

Libraries/LibWeb/HTML/HTMLCanvasElement.cpp

@@ -23,7 +23,6 @@
 #include <LibWeb/HTML/HTMLCanvasElement.h>
 #include <LibWeb/HTML/Numbers.h>
 #include <LibWeb/HTML/Scripting/ExceptionReporter.h>
-#include <LibWeb/HTML/TraversableNavigable.h>
 #include <LibWeb/Layout/CanvasBox.h>
 #include <LibWeb/Page/Page.h>
 #include <LibWeb/Platform/EventLoopPlugin.h>
@@ -307,14 +306,13 @@ Gfx::IntSize HTMLCanvasElement::bitmap_size_for_canvas(size_t minimum_width, siz
 // https://html.spec.whatwg.org/multipage/canvas.html#dom-canvas-todataurl
 String HTMLCanvasElement::to_data_url(StringView type, JS::Value js_quality)
 {
-    // It is possible the canvas doesn't have a associated bitmap so create one
+    // It is possible the canvas doesn't have an associated bitmap so create one
     allocate_painting_surface_if_needed();
     auto surface = this->surface();
     auto size = bitmap_size_for_canvas();
     if (!surface && !size.is_empty()) {
         // If the context is not initialized yet, we need to allocate transparent surface for serialization
-        auto skia_backend_context = navigable()->traversable_navigable()->skia_backend_context();
-        surface = Gfx::PaintingSurface::create_with_size(skia_backend_context, size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
+        surface = Gfx::PaintingSurface::create_with_size(size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
     }
 
     // FIXME: 1. If this canvas element's bitmap's origin-clean flag is set to false, then throw a "SecurityError" DOMException.
@@ -391,8 +389,7 @@ RefPtr<Gfx::Bitmap> HTMLCanvasElement::get_bitmap_from_surface()
     auto surface = this->surface();
     if (auto const size = bitmap_size_for_canvas(); !surface && !size.is_empty()) {
         // If the context is not initialized yet, we need to allocate transparent surface for serialization
-        auto const skia_backend_context = navigable()->traversable_navigable()->skia_backend_context();
-        surface = Gfx::PaintingSurface::create_with_size(skia_backend_context, size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
+        surface = Gfx::PaintingSurface::create_with_size(size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
     }
 
     RefPtr<Gfx::Bitmap> bitmap;

Libraries/LibWeb/HTML/Navigable.cpp

@@ -145,28 +145,6 @@ bool Navigable::is_ancestor_of(GC::Ref<Navigable> other) const
     return false;
 }
 
-static RefPtr<Gfx::SkiaBackendContext> g_cached_skia_backend_context;
-
-static RefPtr<Gfx::SkiaBackendContext> get_skia_backend_context()
-{
-    if (!g_cached_skia_backend_context) {
-#ifdef AK_OS_MACOS
-        auto metal_context = Gfx::get_metal_context();
-        g_cached_skia_backend_context = Gfx::SkiaBackendContext::create_metal_context(*metal_context);
-#elif USE_VULKAN
-        auto maybe_vulkan_context = Gfx::create_vulkan_context();
-        if (maybe_vulkan_context.is_error()) {
-            dbgln("Vulkan context creation failed: {}", maybe_vulkan_context.error());
-            return {};
-        }
-
-        auto vulkan_context = maybe_vulkan_context.release_value();
-        g_cached_skia_backend_context = Gfx::SkiaBackendContext::create_vulkan_context(vulkan_context);
-#endif
-    }
-    return g_cached_skia_backend_context;
-}
-
 Navigable::Navigable(GC::Ref<Page> page, bool is_svg_page)
     : m_page(page)
     , m_event_handler({}, *this)
@@ -179,19 +157,9 @@ Navigable::Navigable(GC::Ref<Page> page, bool is_svg_page)
 {
     all_navigables().set(*this);
 
-    auto display_list_player_type = page->client().display_list_player_type();
-    if (display_list_player_type == DisplayListPlayerType::SkiaGPUIfAvailable) {
-        m_skia_backend_context = get_skia_backend_context();
-    }
-
     if (!m_is_svg_page) {
-        OwnPtr<Painting::DisplayListPlayerSkia> skia_player;
-        if (display_list_player_type == DisplayListPlayerType::SkiaGPUIfAvailable) {
-            skia_player = make<Painting::DisplayListPlayerSkia>(m_skia_backend_context);
-        } else {
-            skia_player = make<Painting::DisplayListPlayerSkia>();
-        }
-        m_rendering_thread.set_skia_player(move(skia_player));
+        auto display_list_player_type = page->client().display_list_player_type();
+        m_rendering_thread.set_skia_player(make<Painting::DisplayListPlayerSkia>());
         m_rendering_thread.start(display_list_player_type);
     }
 }
@@ -2911,11 +2879,6 @@ void Navigable::render_screenshot(Gfx::PaintingSurface& painting_surface, PaintC
     m_rendering_thread.request_screenshot(painting_surface, move(callback));
 }
 
-RefPtr<Gfx::SkiaBackendContext> Navigable::skia_backend_context() const
-{
-    return m_skia_backend_context;
-}
-
 GC::Ref<WebIDL::Promise> Navigable::scroll_viewport_by_delta(CSSPixelPoint delta)
 {
     auto vv = active_document()->visual_viewport();

Libraries/LibWeb/HTML/Navigable.h

@@ -212,8 +212,6 @@ public:
 
     [[nodiscard]] bool has_inclusive_ancestor_with_visibility_hidden() const;
 
-    RefPtr<Gfx::SkiaBackendContext> skia_backend_context() const;
-
     RenderingThread& rendering_thread() { return m_rendering_thread; }
 
     void set_pending_set_browser_zoom_request(bool value) { m_pending_set_browser_zoom_request = value; }
@@ -291,7 +289,6 @@ private:
     bool m_pending_set_browser_zoom_request { false };
     bool m_should_show_line_box_borders { false };
     GC::Ref<Painting::BackingStoreManager> m_backing_store_manager;
-    RefPtr<Gfx::SkiaBackendContext> m_skia_backend_context;
     RenderingThread m_rendering_thread;
 };
 

Libraries/LibWeb/Painting/BackingStoreManager.cpp

@@ -7,6 +7,7 @@
 #include <LibCore/Timer.h>
 #include <LibGfx/Bitmap.h>
 #include <LibGfx/PaintingSurface.h>
+#include <LibGfx/SkiaBackendContext.h>
 #include <LibWeb/HTML/TraversableNavigable.h>
 #include <LibWeb/Painting/BackingStoreManager.h>
 #include <WebContent/PageClient.h>
@@ -50,7 +51,7 @@ void BackingStoreManager::restart_resize_timer()
 
 void BackingStoreManager::reallocate_backing_stores(Gfx::IntSize size)
 {
-    auto skia_backend_context = m_navigable->skia_backend_context();
+    auto skia_backend_context = Gfx::SkiaBackendContext::the();
 
     RefPtr<Gfx::PaintingSurface> front_store;
     RefPtr<Gfx::PaintingSurface> back_store;
@@ -119,11 +120,11 @@ void BackingStoreManager::reallocate_backing_stores(Gfx::IntSize size)
 
 #ifdef USE_VULKAN
     if (skia_backend_context) {
-        front_store = Gfx::PaintingSurface::create_with_size(skia_backend_context, size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
+        front_store = Gfx::PaintingSurface::create_with_size(size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
         front_store->on_flush = [front_bitmap](auto& surface) {
             surface.read_into_bitmap(*front_bitmap);
         };
-        back_store = Gfx::PaintingSurface::create_with_size(skia_backend_context, size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
+        back_store = Gfx::PaintingSurface::create_with_size(size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
         back_store->on_flush = [back_bitmap](auto& surface) {
             surface.read_into_bitmap(*back_bitmap);
         };

Libraries/LibWeb/Painting/DisplayListPlayerSkia.cpp

@@ -28,6 +28,7 @@
 #include <LibGfx/Font/Font.h>
 #include <LibGfx/PainterSkia.h>
 #include <LibGfx/PathSkia.h>
+#include <LibGfx/SkiaBackendContext.h>
 #include <LibGfx/SkiaUtils.h>
 #include <LibWeb/CSS/ComputedValues.h>
 #include <LibWeb/Painting/DisplayListPlayerSkia.h>
@@ -35,11 +36,6 @@
 
 namespace Web::Painting {
 
-DisplayListPlayerSkia::DisplayListPlayerSkia(RefPtr<Gfx::SkiaBackendContext> context)
-    : m_context(context)
-{
-}
-
 DisplayListPlayerSkia::DisplayListPlayerSkia()
 {
 }
@@ -97,8 +93,8 @@ static SkM44 to_skia_matrix4x4(Gfx::FloatMatrix4x4 const& matrix)
 
 void DisplayListPlayerSkia::flush()
 {
-    if (m_context)
-        m_context->flush_and_submit(&surface().sk_surface());
+    if (auto context = Gfx::SkiaBackendContext::the())
+        context->flush_and_submit(&surface().sk_surface());
     surface().flush();
 }
 
@@ -143,7 +139,7 @@ void DisplayListPlayerSkia::draw_external_content(DrawExternalContent const& com
     auto bitmap = command.source->current_bitmap();
     if (!bitmap)
         return;
-    if (m_context && !bitmap->ensure_sk_image(*m_context))
+    if (Gfx::SkiaBackendContext::the() && !bitmap->ensure_sk_image(*Gfx::SkiaBackendContext::the()))
         return;
     auto dst_rect = to_skia_rect(command.dst_rect);
     SkRect src_rect = SkRect::MakeIWH(bitmap->width(), bitmap->height());
@@ -155,7 +151,7 @@ void DisplayListPlayerSkia::draw_external_content(DrawExternalContent const& com
 
 void DisplayListPlayerSkia::draw_scaled_immutable_bitmap(DrawScaledImmutableBitmap const& command)
 {
-    if (m_context && !command.bitmap->ensure_sk_image(*m_context))
+    if (Gfx::SkiaBackendContext::the() && !command.bitmap->ensure_sk_image(*Gfx::SkiaBackendContext::the()))
         return;
 
     auto dst_rect = to_skia_rect(command.dst_rect);
@@ -171,7 +167,7 @@ void DisplayListPlayerSkia::draw_scaled_immutable_bitmap(DrawScaledImmutableBitm
 
 void DisplayListPlayerSkia::draw_repeated_immutable_bitmap(DrawRepeatedImmutableBitmap const& command)
 {
-    if (m_context && !command.bitmap->ensure_sk_image(*m_context))
+    if (Gfx::SkiaBackendContext::the() && !command.bitmap->ensure_sk_image(*Gfx::SkiaBackendContext::the()))
         return;
 
     SkMatrix matrix;
@@ -488,7 +484,7 @@ SkPaint DisplayListPlayerSkia::paint_style_to_skia_paint(Painting::SVGPaintServe
         if (tile_size.is_empty())
             return {};
 
-        auto tile_surface = Gfx::PaintingSurface::create_with_size(m_context, tile_size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
+        auto tile_surface = Gfx::PaintingSurface::create_with_size(tile_size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
 
         execute_display_list_into_surface(*pattern->tile_display_list(), *tile_surface);
 

Libraries/LibWeb/Painting/DisplayListPlayerSkia.h

@@ -6,7 +6,6 @@
 
 #pragma once
 
-#include <LibGfx/SkiaBackendContext.h>
 #include <LibWeb/Painting/DisplayList.h>
 #include <LibWeb/Painting/DisplayListCommand.h>
 #include <LibWeb/Painting/DisplayListRecorder.h>
@@ -18,7 +17,6 @@ namespace Web::Painting {
 
 class DisplayListPlayerSkia final : public DisplayListPlayer {
 public:
-    DisplayListPlayerSkia(RefPtr<Gfx::SkiaBackendContext>);
     DisplayListPlayerSkia();
     ~DisplayListPlayerSkia();
 
@@ -59,8 +57,6 @@ private:
     bool would_be_fully_clipped_by_painter(Gfx::IntRect) const override;
 
     SkPaint paint_style_to_skia_paint(SVGPaintServerPaintStyle const&, Gfx::FloatRect const& bounding_rect);
-
-    RefPtr<Gfx::SkiaBackendContext> m_context;
 };
 
 }

Libraries/LibWeb/SVG/SVGDecodedImageData.cpp

@@ -118,7 +118,7 @@ RefPtr<Gfx::PaintingSurface> SVGDecodedImageData::render_to_surface(Gfx::IntSize
     if (m_cached_rendered_surfaces.size() > 10)
         m_cached_rendered_surfaces.remove(m_cached_rendered_surfaces.begin());
 
-    auto surface = Gfx::PaintingSurface::create_with_size(m_document->navigable()->skia_backend_context(), size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
+    auto surface = Gfx::PaintingSurface::create_with_size(size, Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);
     auto display_list = record_display_list(size);
     if (!display_list)
         return nullptr;

Libraries/LibWeb/WebGL/WebGL2RenderingContext.cpp

@@ -6,12 +6,12 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <LibGfx/SkiaBackendContext.h>
 #include <LibJS/Runtime/ArrayBuffer.h>
 #include <LibJS/Runtime/TypedArray.h>
 #include <LibWeb/Bindings/Intrinsics.h>
 #include <LibWeb/Bindings/WebGL2RenderingContextPrototype.h>
 #include <LibWeb/HTML/HTMLCanvasElement.h>
-#include <LibWeb/HTML/TraversableNavigable.h>
 #include <LibWeb/Infra/Strings.h>
 #include <LibWeb/Painting/Paintable.h>
 #include <LibWeb/WebGL/EventNames.h>
@@ -34,7 +34,7 @@ JS::ThrowCompletionOr<GC::Ptr<WebGL2RenderingContext>> WebGL2RenderingContext::c
     // We should be coming here from getContext being called on a wrapped <canvas> element.
     auto context_attributes = TRY(convert_value_to_context_attributes_dictionary(canvas_element.vm(), options));
 
-    auto skia_backend_context = canvas_element.navigable()->traversable_navigable()->skia_backend_context();
+    auto skia_backend_context = Gfx::SkiaBackendContext::the();
     if (!skia_backend_context) {
         fire_webgl_context_creation_error(canvas_element);
         return GC::Ptr<WebGL2RenderingContext> { nullptr };

Libraries/LibWeb/WebGL/WebGLRenderingContext.cpp

@@ -5,12 +5,12 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <LibGfx/SkiaBackendContext.h>
 #include <LibJS/Runtime/ArrayBuffer.h>
 #include <LibJS/Runtime/TypedArray.h>
 #include <LibWeb/Bindings/Intrinsics.h>
 #include <LibWeb/Bindings/WebGLRenderingContextPrototype.h>
 #include <LibWeb/HTML/HTMLCanvasElement.h>
-#include <LibWeb/HTML/TraversableNavigable.h>
 #include <LibWeb/Infra/Strings.h>
 #include <LibWeb/Painting/Paintable.h>
 #include <LibWeb/WebGL/EventNames.h>
@@ -50,7 +50,7 @@ JS::ThrowCompletionOr<GC::Ptr<WebGLRenderingContext>> WebGLRenderingContext::cre
     // We should be coming here from getContext being called on a wrapped <canvas> element.
     auto context_attributes = TRY(convert_value_to_context_attributes_dictionary(canvas_element.vm(), options));
 
-    auto skia_backend_context = canvas_element.navigable()->traversable_navigable()->skia_backend_context();
+    auto skia_backend_context = Gfx::SkiaBackendContext::the();
     if (!skia_backend_context) {
         fire_webgl_context_creation_error(canvas_element);
         return GC::Ptr<WebGLRenderingContext> { nullptr };

Services/WebContent/main.cpp

@@ -15,6 +15,7 @@
 #include <LibCrypto/OpenSSLForward.h>
 #include <LibGfx/Font/FontDatabase.h>
 #include <LibGfx/Font/PathFontProvider.h>
+#include <LibGfx/SkiaBackendContext.h>
 #include <LibIPC/ConnectionFromClient.h>
 #include <LibIPC/TransportHandle.h>
 #include <LibJS/Bytecode/Interpreter.h>
@@ -198,7 +199,12 @@ ErrorOr<int> ladybird_main(Main::Arguments arguments)
     Web::set_browser_process_executable_path(executable_path);
 
     // Always use the CPU backend for tests, as the GPU backend is not deterministic
-    WebContent::PageClient::set_use_skia_painter(force_cpu_painting ? WebContent::PageClient::UseSkiaPainter::CPUBackend : WebContent::PageClient::UseSkiaPainter::GPUBackendIfAvailable);
+    if (force_cpu_painting) {
+        WebContent::PageClient::set_use_skia_painter(WebContent::PageClient::UseSkiaPainter::CPUBackend);
+    } else {
+        Gfx::SkiaBackendContext::initialize_gpu_backend();
+        WebContent::PageClient::set_use_skia_painter(WebContent::PageClient::UseSkiaPainter::GPUBackendIfAvailable);
+    }
 
     WebContent::PageClient::set_is_headless(is_headless);
 

Tests/LibWeb/Crash/HTML/canvas-2d-in-detached-doc.html

@@ -0,0 +1,8 @@
+<!DOCTYPE html>
+<script>
+var doc = document.implementation.createHTMLDocument("");
+var canvas = doc.createElement("canvas");
+doc.body.appendChild(canvas);
+var ctx = canvas.getContext("2d");
+ctx.fillRect(0, 0, 50, 50);
+</script>

Tests/LibWeb/Crash/HTML/canvas-detached-doc-toDataURL.html

@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<body>
+<script>
+var doc = document.implementation.createHTMLDocument('');
+var canvas = doc.createElement('canvas');
+canvas.width = 100;
+canvas.height = 100;
+doc.body.appendChild(canvas);
+canvas.toDataURL();
+</script>
+</body>

Tests/LibWeb/Crash/HTML/canvas-webgl-in-detached-doc.html

@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<body>
+<script>
+var doc = document.implementation.createHTMLDocument('');
+var canvas = doc.createElement('canvas');
+canvas.width = 100;
+canvas.height = 100;
+doc.body.appendChild(canvas);
+canvas.getContext('webgl');
+</script>
+</body>