From f300a24402afc9f7f3c177e835a0cec10ce52e6c Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 May 2023 13:48:59 +0600
Subject: [PATCH 01/12] Media system refactoring

- animation/layout/render cycle is now managed from a central location
- animations are now throttled if animation/layout/render pass takes longer than a frame which previously caused a soft-freeze with input not being processed
- the public API is trimmed to make sure that we can make other planned changes during the 11.x support cycle

"Changelog":
- IClock is hidden and is planned to be replaced later
- Animator classes are hidden and are planned to be refactored later
- IAnimation members are hidden, it's supposed to be a marker interface for Style.Animations collection now, to start animations manually use Animation.RunAsync
- Sealed several classes in Avalonia.Animation namespace
- Spring class is removed from the public API (it wasn't possible to use it directly in a meaningful way anyway)
- Sealed brushes, transforms, effects and drawings
- Removed separate dispatcher priorities for Layout and Composition, everything now happens from a central place with Render priority (same as WPF)
- - some private "hook" priorities are added for now, those will be removed later
- IRenderLoop is hidden and removed from locator
- IRenderer is hidden (the plan is to remove that concept later)
- - Renderer.Start/Stop exposed as StartRendering/StopRendering on the toplevel (will be on a CompositionTarget/PresentationSource-like type later)
- - Renderer.Diagnistics exposed as RendererDiagnostics (same)
- - Renderer is no longer created by the platform code and is created by TopLevel itself
- - From the user-code hit-testing should be done by VisualExtensions.GetVisual(s)At, which has the same features
- - For unit tests a separate IHitTester interface is added which can be changed for a particular toplevel
- ILayoutManager is hidden
- - LayoutManager.ExecuteLayoutPass() exposed as TopLevel.UpdateLayout()
- Custom animators now have a separate base class that only deals with interpolation

Minor improvements:
- Compositor has a mode that doesn't use DispatcherTimers, useful for unit tests
- Introduced ScopedTestBase that auto-resets the locator when test is finished
---
 nukebuild/RefAssemblyGenerator.cs             |  38 +++-
 .../Pages/ItemsRepeaterPage.xaml.cs           |   3 +-
 samples/GpuInterop/MainWindow.axaml.cs        |   2 +-
 samples/RenderDemo/MainWindow.xaml.cs         |   2 +-
 samples/RenderDemo/Pages/AnimationsPage.xaml  |   4 -
 .../RenderDemo/Pages/AnimationsPage.xaml.cs   |  15 --
 .../RenderDemo/Pages/CustomAnimatorPage.xaml  |  12 +-
 .../RenderDemo/Pages/CustomStringAnimator.cs  |   5 +-
 .../RenderDemo/Pages/Transform3DPage.axaml    |   3 -
 samples/RenderDemo/Pages/TransitionsPage.xaml |   4 -
 .../RenderDemo/Pages/TransitionsPage.xaml.cs  |  15 --
 .../Avalonia.Android/AndroidPlatform.cs       |   1 -
 .../Platform/SkiaPlatform/TopLevelImpl.cs     |   5 +-
 src/Avalonia.Base/Animation/Animatable.cs     |   4 +-
 src/Avalonia.Base/Animation/Animation.cs      |  26 ++-
 .../Animation/AnimatorDrivenTransition.cs     |   9 +-
 .../Animation/AnimatorKeyFrame.cs             |   2 +-
 .../Animation/AnimatorTransitionObservable.cs |   6 +-
 .../Animation/Animators/Animator`1.cs         |   2 +-
 .../Animation/Animators/BaseBrushAnimator.cs  |   2 +-
 .../Animation/Animators/BoolAnimator.cs       |   2 +-
 .../Animation/Animators/BoxShadowAnimator.cs  |   2 +-
 .../Animation/Animators/BoxShadowsAnimator.cs |   2 +-
 .../Animation/Animators/ByteAnimator.cs       |   2 +-
 .../Animation/Animators/ColorAnimator.cs      |   2 +-
 .../Animators/CornerRadiusAnimator.cs         |   2 +-
 .../Animation/Animators/DecimalAnimator.cs    |   2 +-
 .../Animation/Animators/DoubleAnimator.cs     |   2 +-
 .../Animation/Animators/FloatAnimator.cs      |   2 +-
 .../Animators/GradientBrushAnimator.cs        |   2 +-
 .../Animation/Animators/Int16Animator.cs      |   2 +-
 .../Animation/Animators/Int32Animator.cs      |   2 +-
 .../Animation/Animators/Int64Animator.cs      |   2 +-
 .../Animation/Animators/PointAnimator.cs      |   2 +-
 .../Animation/Animators/RectAnimator.cs       |   2 +-
 .../Animators/RelativePointAnimator.cs        |   2 +-
 .../Animation/Animators/SizeAnimator.cs       |   2 +-
 .../Animators/SolidColorBrushAnimator.cs      |   2 +-
 .../Animation/Animators/ThicknessAnimator.cs  |   2 +-
 .../Animation/Animators/TransformAnimator.cs  |   2 +-
 .../Animators/TransformOperationsAnimator.cs  |   2 +-
 .../Animation/Animators/UInt16Animator.cs     |   2 +-
 .../Animation/Animators/UInt32Animator.cs     |   2 +-
 .../Animation/Animators/UInt64Animator.cs     |   2 +-
 .../Animation/Animators/VectorAnimator.cs     |   2 +-
 src/Avalonia.Base/Animation/Clock.cs          |   5 +-
 src/Avalonia.Base/Animation/ClockBase.cs      |   2 +-
 .../Animation/Easings/SpringEasing.cs         |   5 -
 src/Avalonia.Base/Animation/IAnimation.cs     |   4 +-
 .../Animation/IAnimationSetter.cs             |   2 +-
 src/Avalonia.Base/Animation/IAnimator.cs      |   3 +-
 src/Avalonia.Base/Animation/IClock.cs         |   3 +-
 .../Animation/ICustomAnimator.cs              |  30 +++
 src/Avalonia.Base/Animation/IGlobalClock.cs   |   3 +-
 src/Avalonia.Base/Animation/ITransition.cs    |   4 +-
 src/Avalonia.Base/Animation/KeyFrame.cs       |   2 +-
 src/Avalonia.Base/Animation/KeyFrames.cs      |   2 +-
 src/Avalonia.Base/Animation/KeySpline.cs      |   2 +-
 .../Animation/RenderLoopClock.cs              |  26 ---
 src/Avalonia.Base/Animation/Spring.cs         |   2 +-
 .../Animation/SpringTypeConverter.cs          |   2 +-
 src/Avalonia.Base/Animation/Transition.cs     |   7 +-
 .../Animation/TransitionObservableBase.cs     |   4 +-
 src/Avalonia.Base/Animation/Transitions.cs    |   2 +-
 .../Transitions/BoxShadowsTransition.cs       |   6 +-
 .../Animation/Transitions/BrushTransition.cs  |   2 +-
 .../Animation/Transitions/ColorTransition.cs  |   7 +-
 .../Transitions/CornerRadiusTransition.cs     |   7 +-
 .../Animation/Transitions/DoubleTransition.cs |   5 +-
 .../Animation/Transitions/FloatTransition.cs  |   5 +-
 .../Transitions/IntegerTransition.cs          |   5 +-
 .../Animation/Transitions/PointTransition.cs  |   5 +-
 .../Transitions/RelativePointTransition.cs    |   5 +-
 .../Animation/Transitions/SizeTransition.cs   |   5 +-
 .../Transitions/ThicknessTransition.cs        |   5 +-
 .../TransformOperationsTransition.cs          |   2 +-
 .../Animation/Transitions/VectorTransition.cs |   5 +-
 .../TextInput/TransformTrackingHelper.cs      |   2 +-
 src/Avalonia.Base/Layout/ILayoutManager.cs    |   2 +-
 src/Avalonia.Base/Layout/ILayoutRoot.cs       |   2 +-
 src/Avalonia.Base/Layout/LayoutManager.cs     |   9 +-
 src/Avalonia.Base/Media/DashStyle.cs          |   2 +-
 src/Avalonia.Base/Media/Drawing.cs            |   5 +
 src/Avalonia.Base/Media/DrawingBrush.cs       |   2 +-
 src/Avalonia.Base/Media/DrawingGroup.cs       |   2 +-
 src/Avalonia.Base/Media/Effects/BlurEffect.cs |   2 +-
 .../Media/Effects/DropShadowEffect.cs         |   4 +-
 src/Avalonia.Base/Media/Effects/Effect.cs     |   5 +
 .../Media/Effects/EffectAnimator.cs           |   8 +-
 .../Media/Effects/EffectTransition.cs         |   2 +-
 src/Avalonia.Base/Media/GeometryDrawing.cs    |   2 +-
 src/Avalonia.Base/Media/GlyphRunDrawing.cs    |   2 +-
 src/Avalonia.Base/Media/GradientBrush.cs      |   2 +-
 src/Avalonia.Base/Media/ImageBrush.cs         |   2 +-
 src/Avalonia.Base/Media/ImageDrawing.cs       |   2 +-
 src/Avalonia.Base/Media/MatrixTransform.cs    |   2 +-
 src/Avalonia.Base/Media/MediaContext.Clock.cs |  53 ++++++
 .../Media/MediaContext.Compositor.cs          | 135 ++++++++++++++
 src/Avalonia.Base/Media/MediaContext.cs       | 171 ++++++++++++++++++
 src/Avalonia.Base/Media/RotateTransform.cs    |   2 +-
 src/Avalonia.Base/Media/ScaleTransform.cs     |   2 +-
 src/Avalonia.Base/Media/SkewTransform.cs      |   2 +-
 src/Avalonia.Base/Media/SolidColorBrush.cs    |   2 +-
 src/Avalonia.Base/Media/TileBrush.cs          |   5 +
 src/Avalonia.Base/Media/Transform.cs          |   5 +
 src/Avalonia.Base/Media/TransformGroup.cs     |   2 +-
 src/Avalonia.Base/Media/TranslateTransform.cs |   2 +-
 src/Avalonia.Base/Media/VisualBrush.cs        |   2 +-
 .../Metadata/PrivateApiAttribute.cs           |   3 +-
 .../Composition/CompositingRenderer.cs        |  25 +--
 .../Composition/CompositionTarget.cs          |   9 -
 .../Rendering/Composition/Compositor.cs       |  90 +++++----
 .../Server/ServerCompositionTarget.cs         |  30 +--
 .../Composition/Server/ServerCompositor.cs    |  29 ++-
 .../Rendering/Composition/Transport/Batch.cs  |  16 +-
 .../Transport/BatchStreamArrayPool.cs         |  15 +-
 src/Avalonia.Base/Rendering/IRenderLoop.cs    |   2 +-
 .../Rendering/IRenderLoopTask.cs              |   4 +-
 src/Avalonia.Base/Rendering/IRenderRoot.cs    |   4 +-
 src/Avalonia.Base/Rendering/IRenderer.cs      |  58 +++---
 src/Avalonia.Base/Rendering/RenderLoop.cs     |  71 ++------
 .../Rendering/UiThreadRenderTimer.cs          |   2 +-
 src/Avalonia.Base/Rotate3DTransform.cs        |   2 +-
 .../Threading/DispatcherPriority.cs           |  47 +++--
 .../VisualTree/VisualExtensions.cs            |   4 +-
 src/Avalonia.Controls/Application.cs          |   7 +-
 .../Avalonia.Controls.csproj                  |   2 +
 .../Embedding/EmbeddableControlRoot.cs        |   4 +
 .../Offscreen/OffscreenTopLevelImpl.cs        |  10 +-
 src/Avalonia.Controls/NativeControlHost.cs    |   2 +-
 .../Platform/ITopLevelImpl.cs                 |   6 +-
 .../Presenters/TextPresenter.cs               |   2 +-
 .../Primitives/OverlayPopupHost.cs            |   2 +-
 .../Remote/Server/RemoteServerTopLevelImpl.cs |   8 +-
 src/Avalonia.Controls/TopLevel.cs             |  37 +++-
 src/Avalonia.Controls/Window.cs               |  10 +-
 src/Avalonia.Controls/WindowBase.cs           |   4 +-
 .../Remote/PreviewerWindowingPlatform.cs      |   1 -
 src/Avalonia.DesignerSupport/Remote/Stubs.cs  |   6 +-
 src/Avalonia.Native/AvaloniaNativePlatform.cs |   7 +-
 src/Avalonia.Native/WindowImplBase.cs         |  12 +-
 src/Avalonia.X11/X11Platform.cs               |   3 +-
 src/Avalonia.X11/X11Window.cs                 |   9 +-
 .../Avalonia.Browser/BrowserTopLevelImpl.cs   |   9 +-
 .../Avalonia.Browser/WindowingPlatform.cs     |   1 -
 .../AvaloniaHeadlessPlatform.cs               |   5 +-
 .../Avalonia.Headless/HeadlessWindowImpl.cs   |   3 +-
 .../FramebufferToplevelImpl.cs                |   5 +-
 .../LinuxFramebufferPlatform.cs               |  10 +-
 src/Windows/Avalonia.Win32/Win32Platform.cs   |   3 +-
 .../WindowImpl.CustomCaptionProc.cs           |   3 +-
 src/Windows/Avalonia.Win32/WindowImpl.cs      |   3 +-
 src/iOS/Avalonia.iOS/AvaloniaView.cs          |   4 +-
 src/iOS/Avalonia.iOS/Platform.cs              |   1 -
 .../Composition/BatchStreamTests.cs           |   4 +-
 .../Composition/CompositionAnimationTests.cs  |   3 +-
 .../Input/MouseDeviceTests.cs                 |  19 +-
 .../Input/PointerOverTests.cs                 |  75 ++++----
 .../Input/PointerTestsBase.cs                 |  13 +-
 .../Layout/LayoutManagerTests.cs              |   5 +-
 ...ayoutableTests_EffectiveViewportChanged.cs |   5 +
 .../Rendering/RenderLoopTests.cs              | 113 ------------
 .../SceneGraph/DrawOperationTests.cs          |   4 +-
 .../Styling/StyleTests.cs                     |   2 +-
 .../Styling/StyledElementTests.cs             |   4 +-
 .../Styling/StyledElementTests_Theming.cs     |   8 +-
 tests/Avalonia.Base.UnitTests/VisualTests.cs  |   2 +-
 .../ButtonTests.cs                            |  12 +-
 .../ContextMenuTests.cs                       |   5 +-
 .../DesktopStyleApplicationLifetimeTests.cs   |   4 +-
 .../FlyoutTests.cs                            |   4 +-
 .../GridSplitterTests.cs                      |   2 +-
 .../Avalonia.Controls.UnitTests/GridTests.cs  |   2 +-
 .../ListBoxTests.cs                           |   2 +-
 .../MaskedTextBoxTests.cs                     |   4 +-
 .../Primitives/PopupTests.cs                  |  32 ++--
 .../Primitives/SelectingItemsControlTests.cs  |   2 +-
 .../ScrollViewerTests.cs                      |   2 +-
 .../TextBoxTests.cs                           |   4 +-
 .../TopLevelTests.cs                          |  34 ++--
 .../TreeViewTests.cs                          |   2 +-
 .../VirtualizingStackPanelTests.cs            |   2 +-
 .../WindowBaseTests.cs                        |  53 +++---
 .../WindowTests.cs                            |  39 ++--
 tests/Avalonia.LeakTests/ControlTests.cs      |   7 +-
 .../AvaloniaPropertyConverterTest.cs          |   2 +-
 .../PointsListTypeConverterTests.cs           |   2 +-
 .../Xaml/ControlThemeTests.cs                 |   2 -
 .../Xaml/StyleTests.cs                        |   4 +-
 .../XamlTestBase.cs                           |  17 +-
 tests/Avalonia.RenderTests/TestBase.cs        |   4 +-
 tests/Avalonia.RenderTests/TestRenderRoot.cs  |  14 +-
 .../Avalonia.UnitTests.csproj                 |   1 +
 .../CompositorTestServices.cs                 |  26 +--
 .../Avalonia.UnitTests/InternalsVisibleTo.cs  |  11 ++
 tests/Avalonia.UnitTests/MockGlobalClock.cs   |   2 +-
 .../MockWindowingPlatform.cs                  |   9 +-
 tests/Avalonia.UnitTests/RendererMocks.cs     |  23 ++-
 tests/Avalonia.UnitTests/ScopedTestBase.cs    |  18 ++
 tests/Avalonia.UnitTests/TestRoot.cs          |  18 +-
 tests/Avalonia.UnitTests/TestServices.cs      |  37 +++-
 201 files changed, 1254 insertions(+), 821 deletions(-)
 create mode 100644 src/Avalonia.Base/Animation/ICustomAnimator.cs
 delete mode 100644 src/Avalonia.Base/Animation/RenderLoopClock.cs
 create mode 100644 src/Avalonia.Base/Media/MediaContext.Clock.cs
 create mode 100644 src/Avalonia.Base/Media/MediaContext.Compositor.cs
 create mode 100644 src/Avalonia.Base/Media/MediaContext.cs
 delete mode 100644 tests/Avalonia.Base.UnitTests/Rendering/RenderLoopTests.cs
 create mode 100644 tests/Avalonia.UnitTests/InternalsVisibleTo.cs
 create mode 100644 tests/Avalonia.UnitTests/ScopedTestBase.cs

diff --git a/nukebuild/RefAssemblyGenerator.cs b/nukebuild/RefAssemblyGenerator.cs
index e1c19c69a3..dc96849fe7 100644
--- a/nukebuild/RefAssemblyGenerator.cs
+++ b/nukebuild/RefAssemblyGenerator.cs
@@ -71,10 +71,10 @@ public class RefAssemblyGenerator
         foreach (var nested in type.NestedTypes)
             ProcessType(nested, obsoleteCtor);
 
-        var hideMethods = (type.IsInterface && type.Name.EndsWith("Impl"))
+        var hideMembers = (type.IsInterface && type.Name.EndsWith("Impl"))
                           || HasPrivateApi(type.CustomAttributes);
 
-        var injectMethod = hideMethods
+        var injectMethod = hideMembers
                            || type.CustomAttributes.Any(a =>
                                a.AttributeType.FullName == "Avalonia.Metadata.NotClientImplementableAttribute");
 
@@ -95,21 +95,47 @@ public class RefAssemblyGenerator
 
         foreach (var m in type.Methods)
         {
-            if (hideMethods || HasPrivateApi(m.CustomAttributes))
+            if (hideMembers || HasPrivateApi(m.CustomAttributes))
             {
-                var dflags = MethodAttributes.Public | MethodAttributes.Family | MethodAttributes.FamORAssem |
-                             MethodAttributes.FamANDAssem | MethodAttributes.Assembly;
-                m.Attributes = ((m.Attributes | dflags) ^ dflags) | MethodAttributes.Assembly;
+                HideMethod(m);
             }
             MarkAsUnstable(m, obsoleteCtor, forceUnstable);
         }
 
+        foreach (var p in type.Properties)
+        {
+            if (HasPrivateApi(p.CustomAttributes))
+            {
+                if (p.SetMethod != null)
+                    HideMethod(p.SetMethod);
+                if (p.GetMethod != null)
+                    HideMethod(p.GetMethod);
+            }
+        }
+
+        foreach (var f in type.Fields)
+        {
+            if (hideMembers || HasPrivateApi(f.CustomAttributes))
+            {
+                var dflags = FieldAttributes.Public | FieldAttributes.Family | FieldAttributes.FamORAssem |
+                             FieldAttributes.FamANDAssem | FieldAttributes.Assembly;
+                f.Attributes = ((f.Attributes | dflags) ^ dflags) | FieldAttributes.Assembly;
+            }
+        }
+
         foreach (var m in type.Properties)
             MarkAsUnstable(m, obsoleteCtor, forceUnstable);
         foreach (var m in type.Events)
             MarkAsUnstable(m, obsoleteCtor, forceUnstable);
     }
 
+    static void HideMethod(MethodDefinition m)
+    {
+        var dflags = MethodAttributes.Public | MethodAttributes.Family | MethodAttributes.FamORAssem |
+                     MethodAttributes.FamANDAssem | MethodAttributes.Assembly;
+        m.Attributes = ((m.Attributes | dflags) ^ dflags) | MethodAttributes.Assembly;
+    }
+    
     static void MarkAsUnstable(IMemberDefinition def, MethodReference obsoleteCtor, ICustomAttribute unstableAttribute)
     {
         if (def.CustomAttributes.Any(a => a.AttributeType.FullName == "System.ObsoleteAttribute"))
diff --git a/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml.cs b/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml.cs
index 70ce6107ad..2219966daa 100644
--- a/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml.cs
+++ b/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml.cs
@@ -117,9 +117,8 @@ namespace ControlCatalog.Pages
         private void ScrollTo(int index)
         {
             System.Diagnostics.Debug.WriteLine("Scroll to " + index);
-            var layoutManager = ((TopLevel)VisualRoot!).LayoutManager;
             var element = _repeater.GetOrCreateElement(index);
-            layoutManager.ExecuteLayoutPass();
+            ((TopLevel)VisualRoot!).UpdateLayout();
             element.BringIntoView();
         }
 
diff --git a/samples/GpuInterop/MainWindow.axaml.cs b/samples/GpuInterop/MainWindow.axaml.cs
index 7cf0bc00e2..8d359fe7ef 100644
--- a/samples/GpuInterop/MainWindow.axaml.cs
+++ b/samples/GpuInterop/MainWindow.axaml.cs
@@ -11,7 +11,7 @@ namespace GpuInterop
         {
             InitializeComponent();
             this.AttachDevTools();
-            Renderer.Diagnostics.DebugOverlays = RendererDebugOverlays.Fps;
+            RendererDiagnostics.DebugOverlays = RendererDebugOverlays.Fps;
         }
 
         private void InitializeComponent()
diff --git a/samples/RenderDemo/MainWindow.xaml.cs b/samples/RenderDemo/MainWindow.xaml.cs
index d85f3b6051..be47ffd6e9 100644
--- a/samples/RenderDemo/MainWindow.xaml.cs
+++ b/samples/RenderDemo/MainWindow.xaml.cs
@@ -21,7 +21,7 @@ namespace RenderDemo
             void BindOverlay(Expression<Func<MainWindowViewModel, bool>> expr, RendererDebugOverlays overlay)
                 => vm.WhenAnyValue(expr).Subscribe(x =>
                 {
-                    var diagnostics = Renderer.Diagnostics;
+                    var diagnostics = RendererDiagnostics;
                     diagnostics.DebugOverlays = x ?
                         diagnostics.DebugOverlays | overlay :
                         diagnostics.DebugOverlays & ~overlay;
diff --git a/samples/RenderDemo/Pages/AnimationsPage.xaml b/samples/RenderDemo/Pages/AnimationsPage.xaml
index d764af8978..f80389c832 100644
--- a/samples/RenderDemo/Pages/AnimationsPage.xaml
+++ b/samples/RenderDemo/Pages/AnimationsPage.xaml
@@ -347,12 +347,8 @@
   </UserControl.Styles>
   <Grid>
     <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" ClipToBounds="False">
-      <StackPanel.Clock>
-        <Clock />
-      </StackPanel.Clock>
       <StackPanel Orientation="Horizontal" VerticalAlignment="Center" Spacing="20">
         <TextBlock VerticalAlignment="Center">Hover to activate Keyframe Animations.</TextBlock>
-        <Button Content="{Binding PlayStateText}" Command="{Binding TogglePlayState}" Click="ToggleClock" />
       </StackPanel>
       <WrapPanel ClipToBounds="False">
         <Border Classes="Test Rect1" Background="DarkRed"/>
diff --git a/samples/RenderDemo/Pages/AnimationsPage.xaml.cs b/samples/RenderDemo/Pages/AnimationsPage.xaml.cs
index 2195b3d494..fc28f64021 100644
--- a/samples/RenderDemo/Pages/AnimationsPage.xaml.cs
+++ b/samples/RenderDemo/Pages/AnimationsPage.xaml.cs
@@ -24,20 +24,5 @@ namespace RenderDemo.Pages
         {
             AvaloniaXamlLoader.Load(this);
         }
-
-        private void ToggleClock(object sender, RoutedEventArgs args)
-        {
-            var button = sender as Button;
-            var clock = button.Clock;
-
-            if (clock.PlayState == PlayState.Run)
-            {
-                clock.PlayState = PlayState.Pause;
-            }
-            else if (clock.PlayState == PlayState.Pause)
-            {
-                clock.PlayState = PlayState.Run;
-            }
-        }
     }
 }
diff --git a/samples/RenderDemo/Pages/CustomAnimatorPage.xaml b/samples/RenderDemo/Pages/CustomAnimatorPage.xaml
index 0c625b6a77..25379ba13a 100644
--- a/samples/RenderDemo/Pages/CustomAnimatorPage.xaml
+++ b/samples/RenderDemo/Pages/CustomAnimatorPage.xaml
@@ -11,10 +11,18 @@
           <Style.Animations>
             <Animation Duration="0:0:1" IterationCount="Infinite">
               <KeyFrame Cue="0%">
-                <Setter Property="Text" Value="" Animation.Animator="{x:Type pages:CustomStringAnimator}"/>
+                <Setter Property="Text" Value="">
+                  <Animation.Animator>
+                    <pages:CustomStringAnimator/>
+                  </Animation.Animator>
+                </Setter>
               </KeyFrame>
               <KeyFrame Cue="100%">
-                <Setter Property="Text" Value="0123456789" Animation.Animator="{x:Type pages:CustomStringAnimator}"/>
+                <Setter Property="Text" Value="0123456789" >
+                  <Animation.Animator>
+                    <pages:CustomStringAnimator/>
+                  </Animation.Animator>
+                </Setter>
               </KeyFrame>
             </Animation>
           </Style.Animations>
diff --git a/samples/RenderDemo/Pages/CustomStringAnimator.cs b/samples/RenderDemo/Pages/CustomStringAnimator.cs
index 851a2d0187..398319726e 100644
--- a/samples/RenderDemo/Pages/CustomStringAnimator.cs
+++ b/samples/RenderDemo/Pages/CustomStringAnimator.cs
@@ -1,8 +1,9 @@
-using Avalonia.Animation.Animators;
+using Avalonia.Animation;
+using Avalonia.Animation.Animators;
 
 namespace RenderDemo.Pages
 {
-    public class CustomStringAnimator : Animator<string>
+    public class CustomStringAnimator : CustomAnimatorBase<string>
     {
         public override string Interpolate(double progress, string oldValue, string newValue)
         {
diff --git a/samples/RenderDemo/Pages/Transform3DPage.axaml b/samples/RenderDemo/Pages/Transform3DPage.axaml
index 7f3636648c..36e0be3114 100644
--- a/samples/RenderDemo/Pages/Transform3DPage.axaml
+++ b/samples/RenderDemo/Pages/Transform3DPage.axaml
@@ -134,9 +134,6 @@
     </UserControl.Styles>
 
     <Grid ColumnDefinitions="Auto,*,Auto,*" RowDefinitions="*, Auto, Auto, Auto, Auto, Auto, Auto, Auto">
-        <Grid.Clock>
-            <Clock />
-        </Grid.Clock>
         <Border Name="B1" Background="DarkRed" Classes="Test">
             <Border.RenderTransform>
                 <Rotate3DTransform CenterZ="-100"
diff --git a/samples/RenderDemo/Pages/TransitionsPage.xaml b/samples/RenderDemo/Pages/TransitionsPage.xaml
index 006c2eb20b..6e143f97e4 100644
--- a/samples/RenderDemo/Pages/TransitionsPage.xaml
+++ b/samples/RenderDemo/Pages/TransitionsPage.xaml
@@ -248,12 +248,8 @@
 
   <Grid>
     <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" ClipToBounds="False">
-      <StackPanel.Clock>
-        <Clock />
-      </StackPanel.Clock>
       <StackPanel Orientation="Horizontal" VerticalAlignment="Center" Spacing="20">
         <TextBlock VerticalAlignment="Center">Hover to activate Transitions.</TextBlock>
-        <Button Content="{Binding PlayStateText}" Command="{Binding TogglePlayState}" Click="ToggleClock" />
       </StackPanel>
       <WrapPanel ClipToBounds="False">
         <Border Classes="Test Rect1" Background="DarkRed"/>
diff --git a/samples/RenderDemo/Pages/TransitionsPage.xaml.cs b/samples/RenderDemo/Pages/TransitionsPage.xaml.cs
index 5f446c9e99..65b33d5ae8 100644
--- a/samples/RenderDemo/Pages/TransitionsPage.xaml.cs
+++ b/samples/RenderDemo/Pages/TransitionsPage.xaml.cs
@@ -18,20 +18,5 @@ namespace RenderDemo.Pages
         {
             AvaloniaXamlLoader.Load(this);
         }
-
-        private void ToggleClock(object sender, RoutedEventArgs args)
-        {
-            var button = sender as Button;
-            var clock = button.Clock;
-
-            if (clock.PlayState == PlayState.Run)
-            {
-                clock.PlayState = PlayState.Pause;
-            }
-            else if (clock.PlayState == PlayState.Pause)
-            {
-                clock.PlayState = PlayState.Run;
-            }
-        }
     }
 }
diff --git a/src/Android/Avalonia.Android/AndroidPlatform.cs b/src/Android/Avalonia.Android/AndroidPlatform.cs
index 984d3ed5fc..2e22386ef8 100644
--- a/src/Android/Avalonia.Android/AndroidPlatform.cs
+++ b/src/Android/Avalonia.Android/AndroidPlatform.cs
@@ -45,7 +45,6 @@ namespace Avalonia.Android
                 .Bind<IPlatformThreadingInterface>().ToConstant(new AndroidThreadingInterface())
                 .Bind<IPlatformIconLoader>().ToSingleton<PlatformIconLoaderStub>()
                 .Bind<IRenderTimer>().ToConstant(new ChoreographerTimer())
-                .Bind<IRenderLoop>().ToConstant(new RenderLoop())
                 .Bind<PlatformHotkeyConfiguration>().ToSingleton<PlatformHotkeyConfiguration>();
 
             if (Options.UseGpu)
diff --git a/src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs b/src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs
index fae1aacf61..6cc7ca13b6 100644
--- a/src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs
+++ b/src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs
@@ -103,9 +103,8 @@ namespace Avalonia.Android.Platform.SkiaPlatform
 
         public IEnumerable<object> Surfaces => new object[] { _gl, _framebuffer, Handle };
 
-        public IRenderer CreateRenderer(IRenderRoot root) =>
-            new CompositingRenderer(root, AndroidPlatform.Compositor, () => Surfaces);
-
+        public Compositor Compositor => AndroidPlatform.Compositor;
+        
         public virtual void Hide()
         {
             _view.Visibility = ViewStates.Invisible;
diff --git a/src/Avalonia.Base/Animation/Animatable.cs b/src/Avalonia.Base/Animation/Animatable.cs
index 98d4a71415..fb44c10f43 100644
--- a/src/Avalonia.Base/Animation/Animatable.cs
+++ b/src/Avalonia.Base/Animation/Animatable.cs
@@ -17,7 +17,7 @@ namespace Avalonia.Animation
         /// <summary>
         /// Defines the <see cref="Clock"/> property.
         /// </summary>
-        public static readonly StyledProperty<IClock> ClockProperty =
+        internal static readonly StyledProperty<IClock> ClockProperty =
             AvaloniaProperty.Register<Animatable, IClock>(nameof(Clock), inherits: true);
 
         /// <summary>
@@ -36,7 +36,7 @@ namespace Avalonia.Animation
         /// <summary>
         /// Gets or sets the clock which controls the animations on the control.
         /// </summary>
-        public IClock Clock
+        internal IClock Clock
         {
             get => GetValue(ClockProperty);
             set => SetValue(ClockProperty, value);
diff --git a/src/Avalonia.Base/Animation/Animation.cs b/src/Avalonia.Base/Animation/Animation.cs
index dd99c40cd3..ecf796ac4d 100644
--- a/src/Avalonia.Base/Animation/Animation.cs
+++ b/src/Avalonia.Base/Animation/Animation.cs
@@ -16,7 +16,7 @@ namespace Avalonia.Animation
     /// <summary>
     /// Tracks the progress of an animation.
     /// </summary>
-    public class Animation : AvaloniaObject, IAnimation
+    public sealed class Animation : AvaloniaObject, IAnimation
     {
         /// <summary>
         /// Defines the <see cref="Duration"/> property.
@@ -186,7 +186,7 @@ namespace Avalonia.Animation
         /// </summary>
         /// <param name="setter">The animation setter.</param>
         /// <returns>The property animator type.</returns>
-        public static (Type Type, Func<IAnimator> Factory)? GetAnimator(IAnimationSetter setter)
+        internal static (Type Type, Func<IAnimator> Factory)? GetAnimator(IAnimationSetter setter)
         {
             if (s_animators.TryGetValue(setter, out var type))
             {
@@ -200,11 +200,9 @@ namespace Avalonia.Animation
         /// </summary>
         /// <param name="setter">The animation setter.</param>
         /// <param name="value">The property animator value.</param>
-        public static void SetAnimator(IAnimationSetter setter,
-            [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicParameterlessConstructor | DynamicallyAccessedMemberTypes.PublicMethods)]
-            Type value)
+        public static void SetAnimator(IAnimationSetter setter, CustomAnimatorBase value)
         {
-            s_animators[setter] = (value, () => (IAnimator)Activator.CreateInstance(value)!);
+            s_animators[setter] = (value.WrapperType, value.CreateWrapper);
         }
 
         private readonly static List<(Func<AvaloniaProperty, bool> Condition, Type Animator, Func<IAnimator> Factory)> Animators = new()
@@ -233,7 +231,7 @@ namespace Avalonia.Animation
         /// <typeparam name="TAnimator">
         /// The type of the animator to instantiate.
         /// </typeparam>
-        public static void RegisterAnimator<TAnimator>(Func<AvaloniaProperty, bool> condition)
+        internal static void RegisterAnimator<TAnimator>(Func<AvaloniaProperty, bool> condition)
             where TAnimator : IAnimator, new()
         {
             Animators.Insert(0, (condition, typeof(TAnimator), () => new TAnimator()));
@@ -312,8 +310,11 @@ namespace Avalonia.Animation
             return (newAnimatorInstances, subscriptions);
         }
 
+        IDisposable IAnimation.Apply(Animatable control, IClock? clock, IObservable<bool> match, Action? onComplete)
+            => Apply(control, clock, match, onComplete);
+        
         /// <inheritdoc/>
-        public IDisposable Apply(Animatable control, IClock? clock, IObservable<bool> match, Action? onComplete)
+        internal IDisposable Apply(Animatable control, IClock? clock, IObservable<bool> match, Action? onComplete)
         {
             var (animators, subscriptions) = InterpretKeyframes(control);
             if (animators.Count == 1)
@@ -358,14 +359,19 @@ namespace Avalonia.Animation
             return new CompositeDisposable(subscriptions);
         }
 
+        public Task RunAsync(Animatable control) => RunAsync(control, null);
+        
         /// <inheritdoc/>
-        public Task RunAsync(Animatable control, IClock? clock = null)
+        internal Task RunAsync(Animatable control, IClock? clock)
         {
             return RunAsync(control, clock, default);
         }
 
+        Task IAnimation.RunAsync(Animatable control, IClock? clock, CancellationToken cancellationToken)
+            => RunAsync(control, clock, cancellationToken);
+        
         /// <inheritdoc/>
-        public Task RunAsync(Animatable control, IClock? clock = null, CancellationToken cancellationToken = default)
+        internal Task RunAsync(Animatable control, IClock? clock, CancellationToken cancellationToken)
         {
             if (cancellationToken.IsCancellationRequested)
             {
diff --git a/src/Avalonia.Base/Animation/AnimatorDrivenTransition.cs b/src/Avalonia.Base/Animation/AnimatorDrivenTransition.cs
index 88c8ec5ec1..b417c952fb 100644
--- a/src/Avalonia.Base/Animation/AnimatorDrivenTransition.cs
+++ b/src/Avalonia.Base/Animation/AnimatorDrivenTransition.cs
@@ -1,5 +1,6 @@
 using System;
 using Avalonia.Animation.Animators;
+using Avalonia.Animation.Easings;
 
 namespace Avalonia.Animation
 {
@@ -8,13 +9,11 @@ namespace Avalonia.Animation
     /// </summary>
     /// <typeparam name="T">Type of the transitioned value.</typeparam>
     /// <typeparam name="TAnimator">Type of the animator.</typeparam>
-    public abstract class AnimatorDrivenTransition<T, TAnimator> : Transition<T> where TAnimator : Animator<T>, new()
+    internal static class AnimatorDrivenTransition<T, TAnimator> where TAnimator : Animator<T>, new()
     {
         private static readonly TAnimator s_animator = new TAnimator();
 
-        public override IObservable<T> DoTransition(IObservable<double> progress, T oldValue, T newValue)
-        {
-            return new AnimatorTransitionObservable<T, TAnimator>(s_animator, progress, Easing, oldValue, newValue);
-        }
+        public static IObservable<T> Transition(IEasing easing, IObservable<double> progress, T oldValue, T newValue) =>
+            new AnimatorTransitionObservable<T, TAnimator>(s_animator, progress, easing, oldValue, newValue);
     }
 }
diff --git a/src/Avalonia.Base/Animation/AnimatorKeyFrame.cs b/src/Avalonia.Base/Animation/AnimatorKeyFrame.cs
index 892be5cb26..81f742de9a 100644
--- a/src/Avalonia.Base/Animation/AnimatorKeyFrame.cs
+++ b/src/Avalonia.Base/Animation/AnimatorKeyFrame.cs
@@ -11,7 +11,7 @@ namespace Avalonia.Animation
     /// Defines a KeyFrame that is used for
     /// <see cref="Animator{T}"/> objects.
     /// </summary>
-    public class AnimatorKeyFrame : AvaloniaObject
+    internal class AnimatorKeyFrame : AvaloniaObject
     {
         public static readonly DirectProperty<AnimatorKeyFrame, object?> ValueProperty =
             AvaloniaProperty.RegisterDirect<AnimatorKeyFrame, object?>(nameof(Value), k => k.Value, (k, v) => k.Value = v);
diff --git a/src/Avalonia.Base/Animation/AnimatorTransitionObservable.cs b/src/Avalonia.Base/Animation/AnimatorTransitionObservable.cs
index 3cc185179b..7da764b475 100644
--- a/src/Avalonia.Base/Animation/AnimatorTransitionObservable.cs
+++ b/src/Avalonia.Base/Animation/AnimatorTransitionObservable.cs
@@ -9,17 +9,15 @@ namespace Avalonia.Animation
     /// </summary>
     /// <typeparam name="T">Type of the transitioned value.</typeparam>
     /// <typeparam name="TAnimator">Type of the animator.</typeparam>
-    public class AnimatorTransitionObservable<T, TAnimator> : TransitionObservableBase<T> where TAnimator : Animator<T>
+    internal class AnimatorTransitionObservable<T, TAnimator> : TransitionObservableBase<T> where TAnimator : Animator<T>
     {
         private readonly TAnimator _animator;
-        private readonly Easing _easing;
         private readonly T _oldValue;
         private readonly T _newValue;
 
-        public AnimatorTransitionObservable(TAnimator animator, IObservable<double> progress, Easing easing, T oldValue, T newValue) : base(progress, easing)
+        public AnimatorTransitionObservable(TAnimator animator, IObservable<double> progress, IEasing easing, T oldValue, T newValue) : base(progress, easing)
         {
             _animator = animator;
-            _easing = easing;
             _oldValue = oldValue;
             _newValue = newValue;
         }
diff --git a/src/Avalonia.Base/Animation/Animators/Animator`1.cs b/src/Avalonia.Base/Animation/Animators/Animator`1.cs
index 2db890bd0a..f93067d642 100644
--- a/src/Avalonia.Base/Animation/Animators/Animator`1.cs
+++ b/src/Avalonia.Base/Animation/Animators/Animator`1.cs
@@ -11,7 +11,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Base class for <see cref="Animator{T}"/> objects
     /// </summary>
-    public abstract class Animator<T> : AvaloniaList<AnimatorKeyFrame>, IAnimator
+    internal abstract class Animator<T> : AvaloniaList<AnimatorKeyFrame>, IAnimator
     {
         /// <summary>
         /// List of type-converted keyframes.
diff --git a/src/Avalonia.Base/Animation/Animators/BaseBrushAnimator.cs b/src/Avalonia.Base/Animation/Animators/BaseBrushAnimator.cs
index 07c147ef6d..96617b1732 100644
--- a/src/Avalonia.Base/Animation/Animators/BaseBrushAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/BaseBrushAnimator.cs
@@ -15,7 +15,7 @@ namespace Avalonia.Animation.Animators
     /// redirect them to the properly registered
     /// animators in this class.
     /// </summary>
-    public class BaseBrushAnimator : Animator<IBrush?>
+    internal class BaseBrushAnimator : Animator<IBrush?>
     {
         private static readonly List<(Func<Type, bool> Match, Type AnimatorType, Func<IAnimator> AnimatorFactory)> _brushAnimators = new();
 
diff --git a/src/Avalonia.Base/Animation/Animators/BoolAnimator.cs b/src/Avalonia.Base/Animation/Animators/BoolAnimator.cs
index f02fd8dfaa..7c79a53cc5 100644
--- a/src/Avalonia.Base/Animation/Animators/BoolAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/BoolAnimator.cs
@@ -3,7 +3,7 @@
     /// <summary>
     /// Animator that handles <see cref="bool"/> properties.
     /// </summary>
-    public class BoolAnimator : Animator<bool>
+    internal class BoolAnimator : Animator<bool>
     {
         /// <inheritdocs/>
         public override bool Interpolate(double progress, bool oldValue, bool newValue)
diff --git a/src/Avalonia.Base/Animation/Animators/BoxShadowAnimator.cs b/src/Avalonia.Base/Animation/Animators/BoxShadowAnimator.cs
index ff76902425..08ed3cef4a 100644
--- a/src/Avalonia.Base/Animation/Animators/BoxShadowAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/BoxShadowAnimator.cs
@@ -2,7 +2,7 @@ using Avalonia.Media;
 
 namespace Avalonia.Animation.Animators
 {
-    public class BoxShadowAnimator : Animator<BoxShadow>
+    internal class BoxShadowAnimator : Animator<BoxShadow>
     {
         static ColorAnimator s_colorAnimator = new ColorAnimator();
         static DoubleAnimator s_doubleAnimator = new DoubleAnimator();
diff --git a/src/Avalonia.Base/Animation/Animators/BoxShadowsAnimator.cs b/src/Avalonia.Base/Animation/Animators/BoxShadowsAnimator.cs
index c6f96a2d0e..f1d12bfd65 100644
--- a/src/Avalonia.Base/Animation/Animators/BoxShadowsAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/BoxShadowsAnimator.cs
@@ -2,7 +2,7 @@ using Avalonia.Media;
 
 namespace Avalonia.Animation.Animators
 {
-    public class BoxShadowsAnimator :  Animator<BoxShadows>
+    internal class BoxShadowsAnimator : Animator<BoxShadows>
     {
         private static readonly BoxShadowAnimator s_boxShadowAnimator = new BoxShadowAnimator();
         public override BoxShadows Interpolate(double progress, BoxShadows oldValue, BoxShadows newValue)
diff --git a/src/Avalonia.Base/Animation/Animators/ByteAnimator.cs b/src/Avalonia.Base/Animation/Animators/ByteAnimator.cs
index 9fce07895c..337ef9ecff 100644
--- a/src/Avalonia.Base/Animation/Animators/ByteAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/ByteAnimator.cs
@@ -5,7 +5,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="byte"/> properties.
     /// </summary>
-    public class ByteAnimator : Animator<byte>
+    internal class ByteAnimator : Animator<byte>
     {
         const double maxVal = (double)byte.MaxValue;
 
diff --git a/src/Avalonia.Base/Animation/Animators/ColorAnimator.cs b/src/Avalonia.Base/Animation/Animators/ColorAnimator.cs
index 7be974b9e5..719d0d67ab 100644
--- a/src/Avalonia.Base/Animation/Animators/ColorAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/ColorAnimator.cs
@@ -12,7 +12,7 @@ namespace Avalonia.Animation.Animators
     /// Animator that interpolates <see cref="Color"/> through 
     /// gamma sRGB color space for better visual result.
     /// </summary>
-    public class ColorAnimator : Animator<Color>
+    internal class ColorAnimator : Animator<Color>
     {
         /// <summary>
         /// Opto-electronic conversion function for the sRGB color space.
diff --git a/src/Avalonia.Base/Animation/Animators/CornerRadiusAnimator.cs b/src/Avalonia.Base/Animation/Animators/CornerRadiusAnimator.cs
index 8129bd38de..bf52ef0caf 100644
--- a/src/Avalonia.Base/Animation/Animators/CornerRadiusAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/CornerRadiusAnimator.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="CornerRadius"/> properties.
     /// </summary>
-    public class CornerRadiusAnimator : Animator<CornerRadius>
+    internal class CornerRadiusAnimator : Animator<CornerRadius>
     {
         public override CornerRadius Interpolate(double progress, CornerRadius oldValue, CornerRadius newValue)
         {
diff --git a/src/Avalonia.Base/Animation/Animators/DecimalAnimator.cs b/src/Avalonia.Base/Animation/Animators/DecimalAnimator.cs
index 5aed5e5f3d..8c737ca647 100644
--- a/src/Avalonia.Base/Animation/Animators/DecimalAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/DecimalAnimator.cs
@@ -3,7 +3,7 @@
     /// <summary>
     /// Animator that handles <see cref="decimal"/> properties.
     /// </summary>
-    public class DecimalAnimator : Animator<decimal>
+    internal class DecimalAnimator : Animator<decimal>
     {
         /// <inheritdocs/>
         public override decimal Interpolate(double progress, decimal oldValue, decimal newValue)
diff --git a/src/Avalonia.Base/Animation/Animators/DoubleAnimator.cs b/src/Avalonia.Base/Animation/Animators/DoubleAnimator.cs
index 1ca3fabc47..af44bcc9b4 100644
--- a/src/Avalonia.Base/Animation/Animators/DoubleAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/DoubleAnimator.cs
@@ -3,7 +3,7 @@
     /// <summary>
     /// Animator that handles <see cref="double"/> properties.
     /// </summary>
-    public class DoubleAnimator : Animator<double>
+    internal class DoubleAnimator : Animator<double>
     {
         /// <inheritdocs/>
         public override double Interpolate(double progress, double oldValue, double newValue)
diff --git a/src/Avalonia.Base/Animation/Animators/FloatAnimator.cs b/src/Avalonia.Base/Animation/Animators/FloatAnimator.cs
index 62f48a15a3..608f421da5 100644
--- a/src/Avalonia.Base/Animation/Animators/FloatAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/FloatAnimator.cs
@@ -3,7 +3,7 @@
     /// <summary>
     /// Animator that handles <see cref="float"/> properties.
     /// </summary>
-    public class FloatAnimator : Animator<float>
+    internal class FloatAnimator : Animator<float>
     {
         /// <inheritdocs/>
         public override float Interpolate(double progress, float oldValue, float newValue)
diff --git a/src/Avalonia.Base/Animation/Animators/GradientBrushAnimator.cs b/src/Avalonia.Base/Animation/Animators/GradientBrushAnimator.cs
index 801f247754..9cde01f90c 100644
--- a/src/Avalonia.Base/Animation/Animators/GradientBrushAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/GradientBrushAnimator.cs
@@ -13,7 +13,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="SolidColorBrush"/> values. 
     /// </summary>
-    public class GradientBrushAnimator : Animator<IGradientBrush?>
+    internal class GradientBrushAnimator : Animator<IGradientBrush?>
     {
         private static readonly RelativePointAnimator s_relativePointAnimator = new RelativePointAnimator();
         private static readonly DoubleAnimator s_doubleAnimator = new DoubleAnimator();
diff --git a/src/Avalonia.Base/Animation/Animators/Int16Animator.cs b/src/Avalonia.Base/Animation/Animators/Int16Animator.cs
index 5235082fc4..4bd9aa3e84 100644
--- a/src/Avalonia.Base/Animation/Animators/Int16Animator.cs
+++ b/src/Avalonia.Base/Animation/Animators/Int16Animator.cs
@@ -5,7 +5,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="Int16"/> properties.
     /// </summary>
-    public class Int16Animator : Animator<Int16>
+    internal class Int16Animator : Animator<Int16>
     {
         const double maxVal = (double)Int16.MaxValue;
 
diff --git a/src/Avalonia.Base/Animation/Animators/Int32Animator.cs b/src/Avalonia.Base/Animation/Animators/Int32Animator.cs
index 2596f13e84..96c682b18e 100644
--- a/src/Avalonia.Base/Animation/Animators/Int32Animator.cs
+++ b/src/Avalonia.Base/Animation/Animators/Int32Animator.cs
@@ -5,7 +5,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="Int32"/> properties.
     /// </summary>
-    public class Int32Animator : Animator<Int32>
+    internal class Int32Animator : Animator<Int32>
     {
         const double maxVal = (double)Int32.MaxValue;
 
diff --git a/src/Avalonia.Base/Animation/Animators/Int64Animator.cs b/src/Avalonia.Base/Animation/Animators/Int64Animator.cs
index d05750d35c..1db357d64d 100644
--- a/src/Avalonia.Base/Animation/Animators/Int64Animator.cs
+++ b/src/Avalonia.Base/Animation/Animators/Int64Animator.cs
@@ -5,7 +5,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="Int64"/> properties.
     /// </summary>
-    public class Int64Animator : Animator<Int64>
+    internal class Int64Animator : Animator<Int64>
     {
         const double maxVal = (double)Int64.MaxValue;
 
diff --git a/src/Avalonia.Base/Animation/Animators/PointAnimator.cs b/src/Avalonia.Base/Animation/Animators/PointAnimator.cs
index 793691e5ac..8e85abda8a 100644
--- a/src/Avalonia.Base/Animation/Animators/PointAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/PointAnimator.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="Point"/> properties.
     /// </summary>
-    public class PointAnimator : Animator<Point>
+    internal class PointAnimator : Animator<Point>
     {
         public override Point Interpolate(double progress, Point oldValue, Point newValue)
         { 
diff --git a/src/Avalonia.Base/Animation/Animators/RectAnimator.cs b/src/Avalonia.Base/Animation/Animators/RectAnimator.cs
index b2d3ec2996..3b73f3cf82 100644
--- a/src/Avalonia.Base/Animation/Animators/RectAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/RectAnimator.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="Rect"/> properties.
     /// </summary>
-    public class RectAnimator : Animator<Rect>
+    internal class RectAnimator : Animator<Rect>
     {
         public override Rect Interpolate(double progress, Rect oldValue, Rect newValue)
         {
diff --git a/src/Avalonia.Base/Animation/Animators/RelativePointAnimator.cs b/src/Avalonia.Base/Animation/Animators/RelativePointAnimator.cs
index 348a2e4a35..ab49dcd95a 100644
--- a/src/Avalonia.Base/Animation/Animators/RelativePointAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/RelativePointAnimator.cs
@@ -3,7 +3,7 @@
     /// <summary>
     /// Animator that handles <see cref="RelativePoint"/> properties.
     /// </summary>
-    public class RelativePointAnimator : Animator<RelativePoint>
+    internal class RelativePointAnimator : Animator<RelativePoint>
     {
         private static readonly PointAnimator s_pointAnimator = new PointAnimator();
 
diff --git a/src/Avalonia.Base/Animation/Animators/SizeAnimator.cs b/src/Avalonia.Base/Animation/Animators/SizeAnimator.cs
index bb4f343e4a..50f46c9b15 100644
--- a/src/Avalonia.Base/Animation/Animators/SizeAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/SizeAnimator.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="Size"/> properties.
     /// </summary>
-    public class SizeAnimator : Animator<Size>
+    internal class SizeAnimator : Animator<Size>
     {
         public override Size Interpolate(double progress, Size oldValue, Size newValue)
         {
diff --git a/src/Avalonia.Base/Animation/Animators/SolidColorBrushAnimator.cs b/src/Avalonia.Base/Animation/Animators/SolidColorBrushAnimator.cs
index 9256c7be5e..ddeb3637b9 100644
--- a/src/Avalonia.Base/Animation/Animators/SolidColorBrushAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/SolidColorBrushAnimator.cs
@@ -10,7 +10,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="SolidColorBrush"/> values. 
     /// </summary>
-    public class ISolidColorBrushAnimator : Animator<ISolidColorBrush?>
+    internal class ISolidColorBrushAnimator : Animator<ISolidColorBrush?>
     {
         private static readonly DoubleAnimator s_doubleAnimator = new DoubleAnimator();
 
diff --git a/src/Avalonia.Base/Animation/Animators/ThicknessAnimator.cs b/src/Avalonia.Base/Animation/Animators/ThicknessAnimator.cs
index a6ae95ce3f..0dd497329c 100644
--- a/src/Avalonia.Base/Animation/Animators/ThicknessAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/ThicknessAnimator.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="Thickness"/> properties.
     /// </summary>
-    public class ThicknessAnimator : Animator<Thickness>
+    internal class ThicknessAnimator : Animator<Thickness>
     {
         public override Thickness Interpolate(double progress, Thickness oldValue, Thickness newValue)
         {
diff --git a/src/Avalonia.Base/Animation/Animators/TransformAnimator.cs b/src/Avalonia.Base/Animation/Animators/TransformAnimator.cs
index 8040fb595b..c6155837ec 100644
--- a/src/Avalonia.Base/Animation/Animators/TransformAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/TransformAnimator.cs
@@ -9,7 +9,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="Transform"/> properties.
     /// </summary>
-    public class TransformAnimator : Animator<double>
+    internal class TransformAnimator : Animator<double>
     {
         DoubleAnimator? _doubleAnimator;
 
diff --git a/src/Avalonia.Base/Animation/Animators/TransformOperationsAnimator.cs b/src/Avalonia.Base/Animation/Animators/TransformOperationsAnimator.cs
index 8e9d20eb8f..bf88da04c1 100644
--- a/src/Avalonia.Base/Animation/Animators/TransformOperationsAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/TransformOperationsAnimator.cs
@@ -4,7 +4,7 @@ using Avalonia.Media.Transformation;
 
 namespace Avalonia.Animation.Animators
 {
-    public class TransformOperationsAnimator : Animator<TransformOperations>
+    internal class TransformOperationsAnimator : Animator<TransformOperations>
     {
         public TransformOperationsAnimator()
         {
diff --git a/src/Avalonia.Base/Animation/Animators/UInt16Animator.cs b/src/Avalonia.Base/Animation/Animators/UInt16Animator.cs
index 6c9588a966..d0d208827f 100644
--- a/src/Avalonia.Base/Animation/Animators/UInt16Animator.cs
+++ b/src/Avalonia.Base/Animation/Animators/UInt16Animator.cs
@@ -5,7 +5,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="UInt16"/> properties.
     /// </summary>
-    public class UInt16Animator : Animator<UInt16>
+    internal class UInt16Animator : Animator<UInt16>
     {
         const double maxVal = (double)UInt16.MaxValue;
 
diff --git a/src/Avalonia.Base/Animation/Animators/UInt32Animator.cs b/src/Avalonia.Base/Animation/Animators/UInt32Animator.cs
index e2af533566..35fff24cb6 100644
--- a/src/Avalonia.Base/Animation/Animators/UInt32Animator.cs
+++ b/src/Avalonia.Base/Animation/Animators/UInt32Animator.cs
@@ -5,7 +5,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="UInt32"/> properties.
     /// </summary>
-    public class UInt32Animator : Animator<UInt32>
+    internal class UInt32Animator : Animator<UInt32>
     {
         const double maxVal = (double)UInt32.MaxValue;
 
diff --git a/src/Avalonia.Base/Animation/Animators/UInt64Animator.cs b/src/Avalonia.Base/Animation/Animators/UInt64Animator.cs
index a709a77100..cb3211c822 100644
--- a/src/Avalonia.Base/Animation/Animators/UInt64Animator.cs
+++ b/src/Avalonia.Base/Animation/Animators/UInt64Animator.cs
@@ -5,7 +5,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="UInt64"/> properties.
     /// </summary>
-    public class UInt64Animator : Animator<UInt64>
+    internal class UInt64Animator : Animator<UInt64>
     {
         const double maxVal = (double)UInt64.MaxValue;
 
diff --git a/src/Avalonia.Base/Animation/Animators/VectorAnimator.cs b/src/Avalonia.Base/Animation/Animators/VectorAnimator.cs
index e1ffb60971..90cdf017fd 100644
--- a/src/Avalonia.Base/Animation/Animators/VectorAnimator.cs
+++ b/src/Avalonia.Base/Animation/Animators/VectorAnimator.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Animation.Animators
     /// <summary>
     /// Animator that handles <see cref="Vector"/> properties.
     /// </summary>
-    public class VectorAnimator : Animator<Vector>
+    internal class VectorAnimator : Animator<Vector>
     {
         public override Vector Interpolate(double progress, Vector oldValue, Vector newValue)
         {
diff --git a/src/Avalonia.Base/Animation/Clock.cs b/src/Avalonia.Base/Animation/Clock.cs
index f2bce9d3a5..10282f2b79 100644
--- a/src/Avalonia.Base/Animation/Clock.cs
+++ b/src/Avalonia.Base/Animation/Clock.cs
@@ -3,7 +3,10 @@ using Avalonia.Reactive;
 
 namespace Avalonia.Animation
 {
-    public class Clock : ClockBase
+    // Note: this class was always broken: it subscribes to the global clock immediately even it if
+    // doesn't actually have subscriptions
+    
+    internal class Clock : ClockBase
     {
         public static IClock GlobalClock => AvaloniaLocator.Current.GetRequiredService<IGlobalClock>();
 
diff --git a/src/Avalonia.Base/Animation/ClockBase.cs b/src/Avalonia.Base/Animation/ClockBase.cs
index c6e5a363be..f8b79f650d 100644
--- a/src/Avalonia.Base/Animation/ClockBase.cs
+++ b/src/Avalonia.Base/Animation/ClockBase.cs
@@ -3,7 +3,7 @@ using Avalonia.Reactive;
 
 namespace Avalonia.Animation
 {
-    public class ClockBase : IClock
+    internal class ClockBase : IClock
     {
         private readonly ClockObservable _observable;
 
diff --git a/src/Avalonia.Base/Animation/Easings/SpringEasing.cs b/src/Avalonia.Base/Animation/Easings/SpringEasing.cs
index 70e74c639f..c850498495 100644
--- a/src/Avalonia.Base/Animation/Easings/SpringEasing.cs
+++ b/src/Avalonia.Base/Animation/Easings/SpringEasing.cs
@@ -64,11 +64,6 @@ public class SpringEasing : Easing
         Damping = damping;
         InitialVelocity = initialVelocity;
     }
-
-    public SpringEasing(Spring keySpline)
-    {
-        _internalSpring = keySpline;
-    }
     
     public SpringEasing()
     {
diff --git a/src/Avalonia.Base/Animation/IAnimation.cs b/src/Avalonia.Base/Animation/IAnimation.cs
index eda86ed106..a5b8b75b12 100644
--- a/src/Avalonia.Base/Animation/IAnimation.cs
+++ b/src/Avalonia.Base/Animation/IAnimation.cs
@@ -14,11 +14,11 @@ namespace Avalonia.Animation
         /// <summary>
         /// Apply the animation to the specified control and run it when <paramref name="match" /> produces <c>true</c>.
         /// </summary>
-        IDisposable Apply(Animatable control, IClock? clock, IObservable<bool> match, Action? onComplete = null);
+        internal IDisposable Apply(Animatable control, IClock? clock, IObservable<bool> match, Action? onComplete = null);
 
         /// <summary>
         /// Run the animation on the specified control.
         /// </summary>
-        Task RunAsync(Animatable control, IClock clock, CancellationToken cancellationToken = default);
+        internal Task RunAsync(Animatable control, IClock clock, CancellationToken cancellationToken = default);
     }
 }
diff --git a/src/Avalonia.Base/Animation/IAnimationSetter.cs b/src/Avalonia.Base/Animation/IAnimationSetter.cs
index 8c4ba95517..2925f1e0b9 100644
--- a/src/Avalonia.Base/Animation/IAnimationSetter.cs
+++ b/src/Avalonia.Base/Animation/IAnimationSetter.cs
@@ -2,7 +2,7 @@ using Avalonia.Metadata;
 
 namespace Avalonia.Animation
 {
-    [NotClientImplementable]
+    [NotClientImplementable, PrivateApi]
     public interface IAnimationSetter
     {
         AvaloniaProperty? Property { get; set; }
diff --git a/src/Avalonia.Base/Animation/IAnimator.cs b/src/Avalonia.Base/Animation/IAnimator.cs
index 06ba8dc329..9fed7be9be 100644
--- a/src/Avalonia.Base/Animation/IAnimator.cs
+++ b/src/Avalonia.Base/Animation/IAnimator.cs
@@ -7,8 +7,7 @@ namespace Avalonia.Animation
     /// <summary>
     /// Interface for Animator objects
     /// </summary>
-    [NotClientImplementable]
-    public interface IAnimator : IList<AnimatorKeyFrame>
+    internal interface IAnimator : IList<AnimatorKeyFrame>
     {
         /// <summary>
         /// The target property.
diff --git a/src/Avalonia.Base/Animation/IClock.cs b/src/Avalonia.Base/Animation/IClock.cs
index 7b3b7b3924..78e5c38103 100644
--- a/src/Avalonia.Base/Animation/IClock.cs
+++ b/src/Avalonia.Base/Animation/IClock.cs
@@ -3,8 +3,7 @@ using Avalonia.Metadata;
 
 namespace Avalonia.Animation
 {
-    [NotClientImplementable]
-    public interface IClock : IObservable<TimeSpan>
+    internal interface IClock : IObservable<TimeSpan>
     {
         PlayState PlayState { get; set; }
     }
diff --git a/src/Avalonia.Base/Animation/ICustomAnimator.cs b/src/Avalonia.Base/Animation/ICustomAnimator.cs
new file mode 100644
index 0000000000..88c9974ca6
--- /dev/null
+++ b/src/Avalonia.Base/Animation/ICustomAnimator.cs
@@ -0,0 +1,30 @@
+using System;
+using Avalonia.Animation.Animators;
+
+namespace Avalonia.Animation;
+
+public abstract class CustomAnimatorBase
+{
+    internal abstract IAnimator CreateWrapper();
+    internal abstract Type WrapperType { get; }
+}
+
+public abstract class CustomAnimatorBase<T> : CustomAnimatorBase
+{
+    public abstract T Interpolate(double progress, T oldValue, T newValue);
+
+    internal override Type WrapperType => typeof(AnimatorWrapper);
+    internal override IAnimator CreateWrapper() => new AnimatorWrapper(this);
+
+    internal class AnimatorWrapper : Animator<T>
+    {
+        private readonly CustomAnimatorBase<T> _parent;
+
+        public AnimatorWrapper(CustomAnimatorBase<T> parent)
+        {
+            _parent = parent;
+        }
+        
+        public override T Interpolate(double progress, T oldValue, T newValue) => _parent.Interpolate(progress, oldValue, newValue);
+    }
+}
\ No newline at end of file
diff --git a/src/Avalonia.Base/Animation/IGlobalClock.cs b/src/Avalonia.Base/Animation/IGlobalClock.cs
index 138dc07539..9b9516aa91 100644
--- a/src/Avalonia.Base/Animation/IGlobalClock.cs
+++ b/src/Avalonia.Base/Animation/IGlobalClock.cs
@@ -2,8 +2,7 @@ using Avalonia.Metadata;
 
 namespace Avalonia.Animation
 {
-    [NotClientImplementable]
-    public interface IGlobalClock : IClock
+    internal interface IGlobalClock : IClock
     {
     }
 }
diff --git a/src/Avalonia.Base/Animation/ITransition.cs b/src/Avalonia.Base/Animation/ITransition.cs
index 639b92ce35..622b30eea4 100644
--- a/src/Avalonia.Base/Animation/ITransition.cs
+++ b/src/Avalonia.Base/Animation/ITransition.cs
@@ -6,13 +6,13 @@ namespace Avalonia.Animation
     /// <summary>
     /// Interface for Transition objects.
     /// </summary>
-    [NotClientImplementable]
+    [NotClientImplementable, PrivateApi]
     public interface ITransition
     {
         /// <summary>
         /// Applies the transition to the specified <see cref="Animatable"/>.
         /// </summary>
-        IDisposable Apply(Animatable control, IClock clock, object? oldValue, object? newValue);
+        internal IDisposable Apply(Animatable control, IClock clock, object? oldValue, object? newValue);
 
         /// <summary>
         /// Gets the property to be animated.
diff --git a/src/Avalonia.Base/Animation/KeyFrame.cs b/src/Avalonia.Base/Animation/KeyFrame.cs
index 3ab7a70d90..9188167d0e 100644
--- a/src/Avalonia.Base/Animation/KeyFrame.cs
+++ b/src/Avalonia.Base/Animation/KeyFrame.cs
@@ -15,7 +15,7 @@ namespace Avalonia.Animation
     /// Stores data regarding a specific key
     /// point and value in an animation.
     /// </summary>
-    public class KeyFrame : AvaloniaObject
+    public sealed class KeyFrame : AvaloniaObject
     {
         private TimeSpan _ktimeSpan;
         private Cue _kCue;
diff --git a/src/Avalonia.Base/Animation/KeyFrames.cs b/src/Avalonia.Base/Animation/KeyFrames.cs
index 2e9efa8691..654526741e 100644
--- a/src/Avalonia.Base/Animation/KeyFrames.cs
+++ b/src/Avalonia.Base/Animation/KeyFrames.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Animation
     /// <summary>
     /// A collection of <see cref="KeyFrame"/>s.
     /// </summary>
-    public class KeyFrames : AvaloniaList<KeyFrame>
+    public sealed class KeyFrames : AvaloniaList<KeyFrame>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="KeyFrames"/> class.
diff --git a/src/Avalonia.Base/Animation/KeySpline.cs b/src/Avalonia.Base/Animation/KeySpline.cs
index ed6adb79b8..218a7599d5 100644
--- a/src/Avalonia.Base/Animation/KeySpline.cs
+++ b/src/Avalonia.Base/Animation/KeySpline.cs
@@ -17,7 +17,7 @@ namespace Avalonia.Animation
     /// See https://docs.microsoft.com/en-us/dotnet/api/system.windows.media.animation.keyspline
     /// </summary>
     [TypeConverter(typeof(KeySplineTypeConverter))]
-    public class KeySpline : AvaloniaObject
+    public sealed class KeySpline : AvaloniaObject
     {
         // Control points
         private double _controlPointX1;
diff --git a/src/Avalonia.Base/Animation/RenderLoopClock.cs b/src/Avalonia.Base/Animation/RenderLoopClock.cs
deleted file mode 100644
index de86b5fee2..0000000000
--- a/src/Avalonia.Base/Animation/RenderLoopClock.cs
+++ /dev/null
@@ -1,26 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using Avalonia.Rendering;
-
-namespace Avalonia.Animation
-{
-    public class RenderLoopClock : ClockBase, IRenderLoopTask, IGlobalClock
-    {
-        protected override void Stop()
-        {
-            AvaloniaLocator.Current.GetRequiredService<IRenderLoop>().Remove(this);
-        }
-
-        bool IRenderLoopTask.NeedsUpdate => HasSubscriptions;
-
-        void IRenderLoopTask.Render()
-        {
-        }
-
-        void IRenderLoopTask.Update(TimeSpan time)
-        {
-            Pulse(time);
-        }
-    }
-}
diff --git a/src/Avalonia.Base/Animation/Spring.cs b/src/Avalonia.Base/Animation/Spring.cs
index 03ada9196d..3117a9c18a 100644
--- a/src/Avalonia.Base/Animation/Spring.cs
+++ b/src/Avalonia.Base/Animation/Spring.cs
@@ -10,7 +10,7 @@ namespace Avalonia.Animation;
 /// Determines how an animation is used based on spring formula.
 /// </summary>
 [TypeConverter(typeof(SpringTypeConverter))]
-public class Spring
+internal class Spring
 {
     private SpringSolver _springSolver;
     private double _mass;
diff --git a/src/Avalonia.Base/Animation/SpringTypeConverter.cs b/src/Avalonia.Base/Animation/SpringTypeConverter.cs
index cfcf4c4a14..95903c74e4 100644
--- a/src/Avalonia.Base/Animation/SpringTypeConverter.cs
+++ b/src/Avalonia.Base/Animation/SpringTypeConverter.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Animation;
 /// <summary>
 /// Converts string values to <see cref="Spring"/> values.
 /// </summary>
-public class SpringTypeConverter : TypeConverter
+internal class SpringTypeConverter : TypeConverter
 {
     public override bool CanConvertFrom(ITypeDescriptorContext? context, Type sourceType)
     {
diff --git a/src/Avalonia.Base/Animation/Transition.cs b/src/Avalonia.Base/Animation/Transition.cs
index d307f348c4..519ed52578 100644
--- a/src/Avalonia.Base/Animation/Transition.cs
+++ b/src/Avalonia.Base/Animation/Transition.cs
@@ -53,10 +53,13 @@ namespace Avalonia.Animation
         /// <summary>
         /// Apply interpolation to the property.
         /// </summary>
-        public abstract IObservable<T> DoTransition(IObservable<double> progress, T oldValue, T newValue);
+        internal abstract IObservable<T> DoTransition(IObservable<double> progress, T oldValue, T newValue);
 
         /// <inheritdocs/>
-        public virtual IDisposable Apply(Animatable control, IClock clock, object? oldValue, object? newValue)
+        IDisposable ITransition.Apply(Animatable control, IClock clock, object? oldValue, object? newValue)
+            => Apply(control, clock, oldValue, newValue);
+        
+        internal virtual IDisposable Apply(Animatable control, IClock clock, object? oldValue, object? newValue)
         {
             if (Property is null)
                 throw new InvalidOperationException("Transition has no property specified.");
diff --git a/src/Avalonia.Base/Animation/TransitionObservableBase.cs b/src/Avalonia.Base/Animation/TransitionObservableBase.cs
index c4ac803135..19d252723d 100644
--- a/src/Avalonia.Base/Animation/TransitionObservableBase.cs
+++ b/src/Avalonia.Base/Animation/TransitionObservableBase.cs
@@ -12,11 +12,11 @@ namespace Avalonia.Animation
     /// <typeparam name="T">Type of the transitioned value.</typeparam>
     public abstract class TransitionObservableBase<T> : SingleSubscriberObservableBase<T>, IObserver<double>
     {
-        private readonly Easing _easing;
+        private readonly IEasing _easing;
         private readonly IObservable<double> _progress;
         private IDisposable? _progressSubscription;
 
-        protected TransitionObservableBase(IObservable<double> progress, Easing easing)
+        protected TransitionObservableBase(IObservable<double> progress, IEasing easing)
         {
             _progress = progress;
             _easing = easing;
diff --git a/src/Avalonia.Base/Animation/Transitions.cs b/src/Avalonia.Base/Animation/Transitions.cs
index 6687a2902d..d94ecdc886 100644
--- a/src/Avalonia.Base/Animation/Transitions.cs
+++ b/src/Avalonia.Base/Animation/Transitions.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Animation
     /// <summary>
     /// A collection of <see cref="ITransition"/> definitions.
     /// </summary>
-    public class Transitions : AvaloniaList<ITransition>
+    public sealed class Transitions : AvaloniaList<ITransition>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="Transitions"/> class.
diff --git a/src/Avalonia.Base/Animation/Transitions/BoxShadowsTransition.cs b/src/Avalonia.Base/Animation/Transitions/BoxShadowsTransition.cs
index 8a070836e9..cb36539938 100644
--- a/src/Avalonia.Base/Animation/Transitions/BoxShadowsTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/BoxShadowsTransition.cs
@@ -1,3 +1,4 @@
+using System;
 using Avalonia.Animation.Animators;
 using Avalonia.Media;
 
@@ -6,7 +7,10 @@ namespace Avalonia.Animation
     /// <summary>
     /// Transition class that handles <see cref="AvaloniaProperty"/> with <see cref="BoxShadows"/> type.
     /// </summary>  
-    public class BoxShadowsTransition : AnimatorDrivenTransition<BoxShadows, BoxShadowsAnimator>
+    public class BoxShadowsTransition : Transition<BoxShadows>
     {
+        internal override IObservable<BoxShadows> DoTransition(IObservable<double> progress, BoxShadows oldValue,
+            BoxShadows newValue) =>
+            AnimatorDrivenTransition<BoxShadows, BoxShadowsAnimator>.Transition(Easing, progress, oldValue, newValue);
     }
 }
diff --git a/src/Avalonia.Base/Animation/Transitions/BrushTransition.cs b/src/Avalonia.Base/Animation/Transitions/BrushTransition.cs
index 4d9c8af4d5..7e2c56e7b6 100644
--- a/src/Avalonia.Base/Animation/Transitions/BrushTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/BrushTransition.cs
@@ -16,7 +16,7 @@ namespace Avalonia.Animation
         private static readonly GradientBrushAnimator s_gradientAnimator = new GradientBrushAnimator();
         private static readonly ISolidColorBrushAnimator s_solidColorBrushAnimator = new ISolidColorBrushAnimator();
 
-        public override IObservable<IBrush?> DoTransition(IObservable<double> progress, IBrush? oldValue, IBrush? newValue)
+        internal override IObservable<IBrush?> DoTransition(IObservable<double> progress, IBrush? oldValue, IBrush? newValue)
         {
             if (oldValue is null || newValue is null)
             {
diff --git a/src/Avalonia.Base/Animation/Transitions/ColorTransition.cs b/src/Avalonia.Base/Animation/Transitions/ColorTransition.cs
index 9b925a3779..620f8524b1 100644
--- a/src/Avalonia.Base/Animation/Transitions/ColorTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/ColorTransition.cs
@@ -1,4 +1,5 @@
-using Avalonia.Animation.Animators;
+using System;
+using Avalonia.Animation.Animators;
 using Avalonia.Media;
 
 namespace Avalonia.Animation
@@ -6,7 +7,9 @@ namespace Avalonia.Animation
     /// <summary>
     /// Transition class that handles <see cref="AvaloniaProperty"/> with <see cref="Color"/> type.
     /// </summary>
-    public class ColorTransition : AnimatorDrivenTransition<Color, ColorAnimator>
+    public class ColorTransition : Transition<Color>
     {
+        internal override IObservable<Color> DoTransition(IObservable<double> progress, Color oldValue, Color newValue)
+            => AnimatorDrivenTransition<Color, ColorAnimator>.Transition(Easing, progress, oldValue, newValue);
     }
 }
diff --git a/src/Avalonia.Base/Animation/Transitions/CornerRadiusTransition.cs b/src/Avalonia.Base/Animation/Transitions/CornerRadiusTransition.cs
index 62b77a64e1..30bf16a14d 100644
--- a/src/Avalonia.Base/Animation/Transitions/CornerRadiusTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/CornerRadiusTransition.cs
@@ -1,3 +1,4 @@
+using System;
 using Avalonia.Animation.Animators;
 
 namespace Avalonia.Animation
@@ -5,7 +6,11 @@ namespace Avalonia.Animation
     /// <summary>
     /// Transition class that handles <see cref="AvaloniaProperty"/> with <see cref="CornerRadius"/> type.
     /// </summary>  
-    public class CornerRadiusTransition : AnimatorDrivenTransition<CornerRadius, CornerRadiusAnimator>
+    public class CornerRadiusTransition : Transition<CornerRadius>
     {
+        internal override IObservable<CornerRadius> DoTransition(IObservable<double> progress, CornerRadius oldValue,
+            CornerRadius newValue) =>
+            AnimatorDrivenTransition<CornerRadius, CornerRadiusAnimator>.Transition(Easing, progress, oldValue,
+                newValue);
     }
 }
diff --git a/src/Avalonia.Base/Animation/Transitions/DoubleTransition.cs b/src/Avalonia.Base/Animation/Transitions/DoubleTransition.cs
index 7232d87863..fa17cd1eb3 100644
--- a/src/Avalonia.Base/Animation/Transitions/DoubleTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/DoubleTransition.cs
@@ -1,3 +1,4 @@
+using System;
 using Avalonia.Animation.Animators;
 
 namespace Avalonia.Animation
@@ -5,7 +6,9 @@ namespace Avalonia.Animation
     /// <summary>
     /// Transition class that handles <see cref="AvaloniaProperty"/> with <see cref="double"/> types.
     /// </summary>  
-    public class DoubleTransition : AnimatorDrivenTransition<double, DoubleAnimator>
+    public class DoubleTransition : Transition<double>
     {
+        internal override IObservable<double> DoTransition(IObservable<double> progress, double oldValue, double newValue) => 
+            AnimatorDrivenTransition<double, DoubleAnimator>.Transition(Easing, progress, oldValue, newValue);
     }
 }
diff --git a/src/Avalonia.Base/Animation/Transitions/FloatTransition.cs b/src/Avalonia.Base/Animation/Transitions/FloatTransition.cs
index a96db8ba5b..0b109d0851 100644
--- a/src/Avalonia.Base/Animation/Transitions/FloatTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/FloatTransition.cs
@@ -1,3 +1,4 @@
+using System;
 using Avalonia.Animation.Animators;
 
 namespace Avalonia.Animation
@@ -5,7 +6,9 @@ namespace Avalonia.Animation
     /// <summary>
     /// Transition class that handles <see cref="AvaloniaProperty"/> with <see cref="float"/> types.
     /// </summary>  
-    public class FloatTransition : AnimatorDrivenTransition<float, FloatAnimator>
+    public class FloatTransition : Transition<float>
     {
+        internal override IObservable<float> DoTransition(IObservable<double> progress, float oldValue, float newValue) => 
+            AnimatorDrivenTransition<float, FloatAnimator>.Transition(Easing, progress, oldValue, newValue);
     }
 }
diff --git a/src/Avalonia.Base/Animation/Transitions/IntegerTransition.cs b/src/Avalonia.Base/Animation/Transitions/IntegerTransition.cs
index 343da7b689..c5a866d9cb 100644
--- a/src/Avalonia.Base/Animation/Transitions/IntegerTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/IntegerTransition.cs
@@ -1,3 +1,4 @@
+using System;
 using Avalonia.Animation.Animators;
 
 namespace Avalonia.Animation
@@ -5,7 +6,9 @@ namespace Avalonia.Animation
     /// <summary>
     /// Transition class that handles <see cref="AvaloniaProperty"/> with <see cref="int"/> types.
     /// </summary>  
-    public class IntegerTransition : AnimatorDrivenTransition<int, Int32Animator>
+    public class IntegerTransition : Transition<int>
     {
+        internal override IObservable<int> DoTransition(IObservable<double> progress, int oldValue, int newValue) => 
+            AnimatorDrivenTransition<int, Int32Animator>.Transition(Easing, progress, oldValue, newValue);
     }
 }
diff --git a/src/Avalonia.Base/Animation/Transitions/PointTransition.cs b/src/Avalonia.Base/Animation/Transitions/PointTransition.cs
index 0985aaa8f8..e1c4cfccf5 100644
--- a/src/Avalonia.Base/Animation/Transitions/PointTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/PointTransition.cs
@@ -1,3 +1,4 @@
+using System;
 using Avalonia.Animation.Animators;
 
 namespace Avalonia.Animation
@@ -5,7 +6,9 @@ namespace Avalonia.Animation
     /// <summary>
     /// Transition class that handles <see cref="AvaloniaProperty"/> with <see cref="Point"/> type.
     /// </summary>  
-    public class PointTransition : AnimatorDrivenTransition<Point, PointAnimator>
+    public class PointTransition : Transition<Point>
     {
+        internal override IObservable<Point> DoTransition(IObservable<double> progress, Point oldValue, Point newValue) => 
+            AnimatorDrivenTransition<Point, PointAnimator>.Transition(Easing, progress, oldValue, newValue);
     }
 }
diff --git a/src/Avalonia.Base/Animation/Transitions/RelativePointTransition.cs b/src/Avalonia.Base/Animation/Transitions/RelativePointTransition.cs
index 4a7bfa8384..6828bffbe8 100644
--- a/src/Avalonia.Base/Animation/Transitions/RelativePointTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/RelativePointTransition.cs
@@ -1,3 +1,4 @@
+using System;
 using Avalonia.Animation.Animators;
 
 namespace Avalonia.Animation
@@ -5,7 +6,9 @@ namespace Avalonia.Animation
     /// <summary>
     /// Transition class that handles <see cref="AvaloniaProperty"/> with <see cref="RelativePoint"/> type.
     /// </summary>  
-    public class RelativePointTransition : AnimatorDrivenTransition<RelativePoint, RelativePointAnimator>
+    public class RelativePointTransition : Transition<RelativePoint>
     {
+        internal override IObservable<RelativePoint> DoTransition(IObservable<double> progress, RelativePoint oldValue, RelativePoint newValue) =>
+            AnimatorDrivenTransition<RelativePoint, RelativePointAnimator>.Transition(Easing, progress, oldValue, newValue);
     }
 }
diff --git a/src/Avalonia.Base/Animation/Transitions/SizeTransition.cs b/src/Avalonia.Base/Animation/Transitions/SizeTransition.cs
index 6e59fb3631..790d2b8e6c 100644
--- a/src/Avalonia.Base/Animation/Transitions/SizeTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/SizeTransition.cs
@@ -1,3 +1,4 @@
+using System;
 using Avalonia.Animation.Animators;
 
 namespace Avalonia.Animation
@@ -5,7 +6,9 @@ namespace Avalonia.Animation
     /// <summary>
     /// Transition class that handles <see cref="AvaloniaProperty"/> with <see cref="Size"/> type.
     /// </summary>  
-    public class SizeTransition : AnimatorDrivenTransition<Size, SizeAnimator>
+    public class SizeTransition : Transition<Size>
     {
+        internal override IObservable<Size> DoTransition(IObservable<double> progress, Size oldValue, Size newValue) => 
+            AnimatorDrivenTransition<Size, SizeAnimator>.Transition(Easing, progress, oldValue, newValue);
     }
 }
diff --git a/src/Avalonia.Base/Animation/Transitions/ThicknessTransition.cs b/src/Avalonia.Base/Animation/Transitions/ThicknessTransition.cs
index f50929348f..fd188dab43 100644
--- a/src/Avalonia.Base/Animation/Transitions/ThicknessTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/ThicknessTransition.cs
@@ -1,3 +1,4 @@
+using System;
 using Avalonia.Animation.Animators;
 
 namespace Avalonia.Animation
@@ -5,7 +6,9 @@ namespace Avalonia.Animation
     /// <summary>
     /// Transition class that handles <see cref="AvaloniaProperty"/> with <see cref="Thickness"/> type.
     /// </summary>  
-    public class ThicknessTransition : AnimatorDrivenTransition<Thickness, ThicknessAnimator>
+    public class ThicknessTransition : Transition<Thickness>
     {
+        internal override IObservable<Thickness> DoTransition(IObservable<double> progress, Thickness oldValue, Thickness newValue) => 
+            AnimatorDrivenTransition<Thickness, ThicknessAnimator>.Transition(Easing, progress, oldValue, newValue);
     }
 }
diff --git a/src/Avalonia.Base/Animation/Transitions/TransformOperationsTransition.cs b/src/Avalonia.Base/Animation/Transitions/TransformOperationsTransition.cs
index 73fc23ad99..ad73a05cb6 100644
--- a/src/Avalonia.Base/Animation/Transitions/TransformOperationsTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/TransformOperationsTransition.cs
@@ -11,7 +11,7 @@ namespace Avalonia.Animation
     {
         private static readonly TransformOperationsAnimator s_operationsAnimator = new TransformOperationsAnimator();
 
-        public override IObservable<ITransform> DoTransition(
+        internal override IObservable<ITransform> DoTransition(
             IObservable<double> progress,
             ITransform oldValue,
             ITransform newValue)
diff --git a/src/Avalonia.Base/Animation/Transitions/VectorTransition.cs b/src/Avalonia.Base/Animation/Transitions/VectorTransition.cs
index 596989fbae..b293d1f7cf 100644
--- a/src/Avalonia.Base/Animation/Transitions/VectorTransition.cs
+++ b/src/Avalonia.Base/Animation/Transitions/VectorTransition.cs
@@ -1,3 +1,4 @@
+using System;
 using Avalonia.Animation.Animators;
 
 namespace Avalonia.Animation
@@ -5,7 +6,9 @@ namespace Avalonia.Animation
     /// <summary>
     /// Transition class that handles <see cref="AvaloniaProperty"/> with <see cref="Vector"/> type.
     /// </summary>  
-    public class VectorTransition : AnimatorDrivenTransition<Vector, VectorAnimator>
+    public class VectorTransition : Transition<Vector>
     {
+        internal override IObservable<Vector> DoTransition(IObservable<double> progress, Vector oldValue, Vector newValue) => 
+            AnimatorDrivenTransition<Vector, VectorAnimator>.Transition(Easing, progress, oldValue, newValue);
     }
 }
diff --git a/src/Avalonia.Base/Input/TextInput/TransformTrackingHelper.cs b/src/Avalonia.Base/Input/TextInput/TransformTrackingHelper.cs
index 36ee1fff27..1ea754f0f4 100644
--- a/src/Avalonia.Base/Input/TextInput/TransformTrackingHelper.cs
+++ b/src/Avalonia.Base/Input/TextInput/TransformTrackingHelper.cs
@@ -91,7 +91,7 @@ namespace Avalonia.Input.TextInput
             if(_queuedForUpdate)
                 return;
             _queuedForUpdate = true;
-            Dispatcher.UIThread.Post(UpdateMatrix, DispatcherPriority.Render);
+            Dispatcher.UIThread.Post(UpdateMatrix, DispatcherPriority.AfterRender);
         }
 
         private void PropertyChangedHandler(object? sender, AvaloniaPropertyChangedEventArgs e)
diff --git a/src/Avalonia.Base/Layout/ILayoutManager.cs b/src/Avalonia.Base/Layout/ILayoutManager.cs
index 38d46557e1..063c8e99d2 100644
--- a/src/Avalonia.Base/Layout/ILayoutManager.cs
+++ b/src/Avalonia.Base/Layout/ILayoutManager.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Layout
     /// Manages measuring and arranging of controls.
     /// </summary>
     [NotClientImplementable]
-    public interface ILayoutManager : IDisposable
+    internal interface ILayoutManager : IDisposable
     {
         /// <summary>
         /// Raised when the layout manager completes a layout pass.
diff --git a/src/Avalonia.Base/Layout/ILayoutRoot.cs b/src/Avalonia.Base/Layout/ILayoutRoot.cs
index c90ddb9219..efea5bfed8 100644
--- a/src/Avalonia.Base/Layout/ILayoutRoot.cs
+++ b/src/Avalonia.Base/Layout/ILayoutRoot.cs
@@ -21,6 +21,6 @@ namespace Avalonia.Layout
         /// <summary>
         /// Associated instance of layout manager
         /// </summary>
-        ILayoutManager LayoutManager { get; }
+        internal ILayoutManager LayoutManager { get; }
     }
 }
diff --git a/src/Avalonia.Base/Layout/LayoutManager.cs b/src/Avalonia.Base/Layout/LayoutManager.cs
index 7873f83edb..3665fc4475 100644
--- a/src/Avalonia.Base/Layout/LayoutManager.cs
+++ b/src/Avalonia.Base/Layout/LayoutManager.cs
@@ -4,6 +4,7 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
 using Avalonia.Logging;
+using Avalonia.Media;
 using Avalonia.Rendering;
 using Avalonia.Threading;
 using Avalonia.Utilities;
@@ -15,14 +16,13 @@ namespace Avalonia.Layout
     /// <summary>
     /// Manages measuring and arranging of controls.
     /// </summary>
-    public class LayoutManager : ILayoutManager, IDisposable
+    internal class LayoutManager : ILayoutManager, IDisposable
     {
         private const int MaxPasses = 10;
         private readonly Layoutable _owner;
         private readonly LayoutQueue<Layoutable> _toMeasure = new LayoutQueue<Layoutable>(v => !v.IsMeasureValid);
         private readonly LayoutQueue<Layoutable> _toArrange = new LayoutQueue<Layoutable>(v => !v.IsArrangeValid);
         private readonly List<Layoutable> _toArrangeAfterMeasure = new();
-        private readonly Action _executeLayoutPass;
         private List<EffectiveViewportChangedListener>? _effectiveViewportChangedListeners;
         private bool _disposed;
         private bool _queued;
@@ -32,7 +32,6 @@ namespace Avalonia.Layout
         public LayoutManager(ILayoutRoot owner)
         {
             _owner = owner as Layoutable ?? throw new ArgumentNullException(nameof(owner));
-            _executeLayoutPass = ExecuteQueuedLayoutPass;
         }
 
         public virtual event EventHandler? LayoutUpdated;
@@ -99,7 +98,7 @@ namespace Avalonia.Layout
             QueueLayoutPass();
         }
 
-        private void ExecuteQueuedLayoutPass()
+        internal void ExecuteQueuedLayoutPass()
         {
             if (!_queued)
             {
@@ -346,7 +345,7 @@ namespace Avalonia.Layout
             if (!_queued && !_running)
             {
                 _queued = true;
-                Dispatcher.UIThread.Post(_executeLayoutPass, DispatcherPriority.Layout);
+                MediaContext.Instance.QueueLayoutPass(this);
             }
         }
 
diff --git a/src/Avalonia.Base/Media/DashStyle.cs b/src/Avalonia.Base/Media/DashStyle.cs
index 0efb764029..6e2cea417d 100644
--- a/src/Avalonia.Base/Media/DashStyle.cs
+++ b/src/Avalonia.Base/Media/DashStyle.cs
@@ -13,7 +13,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Represents the sequence of dashes and gaps that will be applied by a <see cref="Pen"/>.
     /// </summary>
-    public class DashStyle : Animatable, IDashStyle
+    public sealed class DashStyle : Animatable, IDashStyle
     {
         /// <summary>
         /// Defines the <see cref="Dashes"/> property.
diff --git a/src/Avalonia.Base/Media/Drawing.cs b/src/Avalonia.Base/Media/Drawing.cs
index 867708f78d..584e5978fc 100644
--- a/src/Avalonia.Base/Media/Drawing.cs
+++ b/src/Avalonia.Base/Media/Drawing.cs
@@ -5,6 +5,11 @@
     /// </summary>
     public abstract class Drawing : AvaloniaObject
     {
+        internal Drawing()
+        {
+            
+        }
+        
         /// <summary>
         /// Draws this drawing to the given <see cref="DrawingContext"/>.
         /// </summary>
diff --git a/src/Avalonia.Base/Media/DrawingBrush.cs b/src/Avalonia.Base/Media/DrawingBrush.cs
index 89e9b9e075..f324c02536 100644
--- a/src/Avalonia.Base/Media/DrawingBrush.cs
+++ b/src/Avalonia.Base/Media/DrawingBrush.cs
@@ -12,7 +12,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Paints an area with an <see cref="Drawing"/>.
     /// </summary>
-    public class DrawingBrush : TileBrush, ISceneBrush
+    public sealed class DrawingBrush : TileBrush, ISceneBrush
     {
         /// <summary>
         /// Defines the <see cref="Drawing"/> property.
diff --git a/src/Avalonia.Base/Media/DrawingGroup.cs b/src/Avalonia.Base/Media/DrawingGroup.cs
index dfcb5c1eb4..f72bcd554c 100644
--- a/src/Avalonia.Base/Media/DrawingGroup.cs
+++ b/src/Avalonia.Base/Media/DrawingGroup.cs
@@ -8,7 +8,7 @@ using Avalonia.Utilities;
 
 namespace Avalonia.Media
 {
-    public class DrawingGroup : Drawing
+    public sealed class DrawingGroup : Drawing
     {
         public static readonly StyledProperty<double> OpacityProperty =
             AvaloniaProperty.Register<DrawingGroup, double>(nameof(Opacity), 1);
diff --git a/src/Avalonia.Base/Media/Effects/BlurEffect.cs b/src/Avalonia.Base/Media/Effects/BlurEffect.cs
index 47c86e4e42..69682b65bc 100644
--- a/src/Avalonia.Base/Media/Effects/BlurEffect.cs
+++ b/src/Avalonia.Base/Media/Effects/BlurEffect.cs
@@ -2,7 +2,7 @@ using System;
 // ReSharper disable CheckNamespace
 namespace Avalonia.Media;
 
-public class BlurEffect : Effect, IBlurEffect, IMutableEffect
+public sealed class BlurEffect : Effect, IBlurEffect, IMutableEffect
 {
     public static readonly StyledProperty<double> RadiusProperty = AvaloniaProperty.Register<BlurEffect, double>(
         nameof(Radius), 5);
diff --git a/src/Avalonia.Base/Media/Effects/DropShadowEffect.cs b/src/Avalonia.Base/Media/Effects/DropShadowEffect.cs
index ea931c0a8c..835a142d8a 100644
--- a/src/Avalonia.Base/Media/Effects/DropShadowEffect.cs
+++ b/src/Avalonia.Base/Media/Effects/DropShadowEffect.cs
@@ -42,7 +42,7 @@ public abstract class DropShadowEffectBase : Effect
     }
 }
 
-public class DropShadowEffect : DropShadowEffectBase, IDropShadowEffect, IMutableEffect
+public sealed class DropShadowEffect : DropShadowEffectBase, IDropShadowEffect, IMutableEffect
 {
     public static readonly StyledProperty<double> OffsetXProperty = AvaloniaProperty.Register<DropShadowEffect, double>(
         nameof(OffsetX), 3.5355);
@@ -76,7 +76,7 @@ public class DropShadowEffect : DropShadowEffectBase, IDropShadowEffect, IMutabl
 /// <summary>
 /// This class is compatible with WPF's DropShadowEffect and provides Direction and ShadowDepth properties instead of OffsetX/OffsetY
 /// </summary>
-public class DropShadowDirectionEffect : DropShadowEffectBase, IDirectionDropShadowEffect, IMutableEffect
+public sealed class DropShadowDirectionEffect : DropShadowEffectBase, IDirectionDropShadowEffect, IMutableEffect
 {
     public static readonly StyledProperty<double> ShadowDepthProperty =
         AvaloniaProperty.Register<DropShadowDirectionEffect, double>(
diff --git a/src/Avalonia.Base/Media/Effects/Effect.cs b/src/Avalonia.Base/Media/Effects/Effect.cs
index 182e8613f8..abc1480d9d 100644
--- a/src/Avalonia.Base/Media/Effects/Effect.cs
+++ b/src/Avalonia.Base/Media/Effects/Effect.cs
@@ -90,4 +90,9 @@ public class Effect : Animatable, IAffectsRender
     {
         EffectAnimator.EnsureRegistered();
     }
+
+    internal Effect()
+    {
+        
+    }
 }
\ No newline at end of file
diff --git a/src/Avalonia.Base/Media/Effects/EffectAnimator.cs b/src/Avalonia.Base/Media/Effects/EffectAnimator.cs
index 70d359911b..8353afa6ab 100644
--- a/src/Avalonia.Base/Media/Effects/EffectAnimator.cs
+++ b/src/Avalonia.Base/Media/Effects/EffectAnimator.cs
@@ -7,7 +7,7 @@ using Avalonia.Media;
 // ReSharper disable once CheckNamespace
 namespace Avalonia.Animation.Animators;
 
-public class EffectAnimator : Animator<IEffect?>
+internal class EffectAnimator : Animator<IEffect?>
 {
     public override IDisposable? Apply(Animation animation, Animatable control, IClock? clock,
         IObservable<bool> match, Action? onComplete)
@@ -68,7 +68,7 @@ public class EffectAnimator : Animator<IEffect?>
     }
 }
 
-public abstract class EffectAnimatorBase<T> : Animator<IEffect?> where T : class, IEffect?
+internal abstract class EffectAnimatorBase<T> : Animator<IEffect?> where T : class, IEffect?
 {
     public override IDisposable BindAnimation(Animatable control, IObservable<IEffect?> instance)
     {
@@ -91,7 +91,7 @@ public abstract class EffectAnimatorBase<T> : Animator<IEffect?> where T : class
     }
 }
 
-public class BlurEffectAnimator : EffectAnimatorBase<IBlurEffect>
+internal class BlurEffectAnimator : EffectAnimatorBase<IBlurEffect>
 {
     private static readonly DoubleAnimator s_doubleAnimator = new DoubleAnimator();
 
@@ -102,7 +102,7 @@ public class BlurEffectAnimator : EffectAnimatorBase<IBlurEffect>
     }
 }
 
-public class DropShadowEffectAnimator : EffectAnimatorBase<IDropShadowEffect>
+internal class DropShadowEffectAnimator : EffectAnimatorBase<IDropShadowEffect>
 {
     private static readonly DoubleAnimator s_doubleAnimator = new DoubleAnimator();
 
diff --git a/src/Avalonia.Base/Media/Effects/EffectTransition.cs b/src/Avalonia.Base/Media/Effects/EffectTransition.cs
index b2e0d07355..d73d82fb2a 100644
--- a/src/Avalonia.Base/Media/Effects/EffectTransition.cs
+++ b/src/Avalonia.Base/Media/Effects/EffectTransition.cs
@@ -50,7 +50,7 @@ public class EffectTransition : Transition<IEffect?>
 
     }
 
-    public override IObservable<IEffect?> DoTransition(IObservable<double> progress, IEffect? oldValue, IEffect? newValue)
+    internal override IObservable<IEffect?> DoTransition(IObservable<double> progress, IEffect? oldValue, IEffect? newValue)
     {
         if ((oldValue != null || newValue != null)
             && (
diff --git a/src/Avalonia.Base/Media/GeometryDrawing.cs b/src/Avalonia.Base/Media/GeometryDrawing.cs
index dd359c5c64..3a768ac5ec 100644
--- a/src/Avalonia.Base/Media/GeometryDrawing.cs
+++ b/src/Avalonia.Base/Media/GeometryDrawing.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Media
     /// Represents a drawing operation that combines 
     /// a geometry with and brush and/or pen to produce rendered content.
     /// </summary>
-    public class GeometryDrawing : Drawing
+    public sealed class GeometryDrawing : Drawing
     {
         // Adding the Pen's stroke thickness here could yield wrong results due to transforms.
         private static readonly IPen s_boundsPen = new ImmutablePen(Colors.Black.ToUInt32(), 0);
diff --git a/src/Avalonia.Base/Media/GlyphRunDrawing.cs b/src/Avalonia.Base/Media/GlyphRunDrawing.cs
index 1bc56c3ff7..199809ccdc 100644
--- a/src/Avalonia.Base/Media/GlyphRunDrawing.cs
+++ b/src/Avalonia.Base/Media/GlyphRunDrawing.cs
@@ -1,6 +1,6 @@
 namespace Avalonia.Media
 {
-    public class GlyphRunDrawing : Drawing
+    public sealed class GlyphRunDrawing : Drawing
     {
         public static readonly StyledProperty<IBrush?> ForegroundProperty =
             AvaloniaProperty.Register<GlyphRunDrawing, IBrush?>(nameof(Foreground));
diff --git a/src/Avalonia.Base/Media/GradientBrush.cs b/src/Avalonia.Base/Media/GradientBrush.cs
index c2068a85ff..1c949c8f56 100644
--- a/src/Avalonia.Base/Media/GradientBrush.cs
+++ b/src/Avalonia.Base/Media/GradientBrush.cs
@@ -37,7 +37,7 @@ namespace Avalonia.Media
         /// </summary>
         [System.Diagnostics.CodeAnalysis.SuppressMessage("AvaloniaProperty", "AVP1012", 
             Justification = "Collection properties shouldn't be set with SetCurrentValue.")]
-        public GradientBrush()
+        internal GradientBrush()
         {
             this.GradientStops = new GradientStops();
         }
diff --git a/src/Avalonia.Base/Media/ImageBrush.cs b/src/Avalonia.Base/Media/ImageBrush.cs
index 48deffb79c..8c0ebb1e29 100644
--- a/src/Avalonia.Base/Media/ImageBrush.cs
+++ b/src/Avalonia.Base/Media/ImageBrush.cs
@@ -10,7 +10,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Paints an area with an <see cref="IBitmap"/>.
     /// </summary>
-    public class ImageBrush : TileBrush, IImageBrush, IMutableBrush
+    public sealed class ImageBrush : TileBrush, IImageBrush, IMutableBrush
     {
         /// <summary>
         /// Defines the <see cref="Visual"/> property.
diff --git a/src/Avalonia.Base/Media/ImageDrawing.cs b/src/Avalonia.Base/Media/ImageDrawing.cs
index ad5e29e87d..ae737b0fb3 100644
--- a/src/Avalonia.Base/Media/ImageDrawing.cs
+++ b/src/Avalonia.Base/Media/ImageDrawing.cs
@@ -5,7 +5,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Draws an image within a region defined by a <see cref="Rect"/>.
     /// </summary>
-    public class ImageDrawing : Drawing
+    public sealed class ImageDrawing : Drawing
     {
         /// <summary>
         /// Defines the <see cref="ImageSource"/> property.
diff --git a/src/Avalonia.Base/Media/MatrixTransform.cs b/src/Avalonia.Base/Media/MatrixTransform.cs
index 22f39b1ee2..01555b76f2 100644
--- a/src/Avalonia.Base/Media/MatrixTransform.cs
+++ b/src/Avalonia.Base/Media/MatrixTransform.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Transforms an <see cref="Visual"/> according to a <see cref="Matrix"/>.
     /// </summary>
-    public class MatrixTransform : Transform
+    public sealed class MatrixTransform : Transform
     {
         /// <summary>
         /// Defines the <see cref="Matrix"/> property.
diff --git a/src/Avalonia.Base/Media/MediaContext.Clock.cs b/src/Avalonia.Base/Media/MediaContext.Clock.cs
new file mode 100644
index 0000000000..dc2a39a822
--- /dev/null
+++ b/src/Avalonia.Base/Media/MediaContext.Clock.cs
@@ -0,0 +1,53 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using Avalonia.Animation;
+using Avalonia.Reactive;
+using Avalonia.Threading;
+
+namespace Avalonia.Media;
+
+internal partial class MediaContext
+{
+    private readonly MediaContextClock _clock;
+    public IGlobalClock Clock => _clock;
+    private readonly Stopwatch _time = Stopwatch.StartNew();
+    
+    class MediaContextClock : IGlobalClock
+    {
+        private readonly MediaContext _parent;
+        private List<IObserver<TimeSpan>> _observers = new();
+        public bool HasNewSubscriptions { get; set; }
+        public bool HasSubscriptions => _observers.Count > 0;
+
+        public MediaContextClock(MediaContext parent)
+        {
+            _parent = parent;
+        }
+
+        public IDisposable Subscribe(IObserver<TimeSpan> observer)
+        {
+            _parent.ScheduleRender(false);
+            Dispatcher.UIThread.VerifyAccess();
+            HasNewSubscriptions = true;
+            _observers.Add(observer);
+            return Disposable.Create(() =>
+            {
+                Dispatcher.UIThread.VerifyAccess();
+                _observers.Remove(observer);
+            });
+        }
+
+        public void Pulse(TimeSpan now)
+        {
+            foreach (var observer in _observers.ToArray())
+                observer.OnNext(now);
+        }
+
+        public PlayState PlayState
+        {
+            get => PlayState.Run;
+            set => throw new InvalidOperationException();
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Avalonia.Base/Media/MediaContext.Compositor.cs b/src/Avalonia.Base/Media/MediaContext.Compositor.cs
new file mode 100644
index 0000000000..d9d3c915d4
--- /dev/null
+++ b/src/Avalonia.Base/Media/MediaContext.Compositor.cs
@@ -0,0 +1,135 @@
+using System;
+using System.Threading.Tasks;
+using Avalonia.Platform;
+using Avalonia.Rendering.Composition;
+using Avalonia.Rendering.Composition.Transport;
+using Avalonia.Threading;
+
+namespace Avalonia.Media;
+
+partial class MediaContext
+{
+    private bool _scheduleCommitOnLastCompositionBatchCompletion;
+    
+    /// <summary>
+    /// Actually sends the current batch to the compositor and does the required housekeeping
+    /// This is the only place that should be allowed to call Commit
+    /// </summary>
+    private Batch CommitCompositor(Compositor compositor)
+    {
+        var commit = compositor.Commit();
+        _requestedCommits.Remove(compositor);
+        _pendingCompositionBatches[compositor] = commit;
+        commit.Processed.ContinueWith(_ =>
+            Dispatcher.UIThread.Post(() => CompositionBatchFinished(compositor, commit), DispatcherPriority.Send));
+        return commit;
+    }
+    
+    /// <summary>
+    /// Handles batch completion, required to re-schedule a render pass if one was skipped due to compositor throttling
+    /// </summary>
+    private void CompositionBatchFinished(Compositor compositor, Batch batch)
+    {
+        // Check if it was the last commited batch, since sometimes we are forced to send a new
+        // one without waiting for the previous one to complete  
+        if (_pendingCompositionBatches.TryGetValue(compositor, out var waitingForBatch) && waitingForBatch == batch)
+            _pendingCompositionBatches.Remove(compositor);
+
+        if (_pendingCompositionBatches.Count == 0)
+        {
+            _animationsAreWaitingForComposition = false;
+
+            // Check if we have uncommited changes
+            if (_scheduleCommitOnLastCompositionBatchCompletion && _pendingCompositionBatches.Count > 0)
+            {
+                CommitCompositorsWithThrottling();
+                _scheduleCommitOnLastCompositionBatchCompletion = false;
+            }
+            // Check if there are active animations and schedule the next render
+            else if(_clock.HasSubscriptions) 
+                ScheduleRender(false);
+        }
+
+    }
+
+    private bool CommitCompositorsWithThrottling()
+    {
+        // Check if we are still waiting for previous composition batches
+        if (_pendingCompositionBatches.Count > 0)
+        {
+            _scheduleCommitOnLastCompositionBatchCompletion = true;
+            return true;
+        }
+
+        if (_requestedCommits.Count == 0)
+            return false;
+        
+        foreach (var c in _requestedCommits)
+            CommitCompositor(c);
+        
+        _requestedCommits.Clear();
+        return true;
+    }
+    
+    /// <summary>
+    /// Executes a synchronous commit when we need to wait for composition jobs to be done
+    /// Is used in resize and TopLevel destruction scenarios
+    /// </summary>
+    private void SyncCommit(Compositor compositor, bool waitFullRender)
+    {
+        // Unit tests are assuming that they can call any API without setting up platforms
+        if (AvaloniaLocator.Current.GetService<IPlatformRenderInterface>() == null)
+            return;
+        
+        if (compositor is
+            {
+                UseUiThreadForSynchronousCommits: false,
+                Loop.RunsInBackground: true
+            })
+        {
+            var batch = CommitCompositor(compositor);
+            (waitFullRender ? batch.Rendered : batch.Processed).Wait();
+        }
+        else
+        {
+            CommitCompositor(compositor);
+            compositor.Server.Render();
+        }
+    }
+    
+    /// <summary>
+    /// This method handles synchronous rendering of a surface when requested by the OS (typically during the resize)
+    /// </summary>
+    // TODO: do we need to execute a render pass here too?
+    // We've previously tried that and it made the resize experience worse
+    public void ImmediateRenderRequested(CompositionTarget target)
+    {
+        SyncCommit(target.Compositor, true);
+    }
+
+
+    /// <summary>
+    /// This method handles synchronous destruction of the composition target, so we are guaranteed
+    /// to release all resources when a TopLevel is being destroyed 
+    /// </summary>
+    public void SyncDisposeCompositionTarget(CompositionTarget compositionTarget)
+    {
+        compositionTarget.Dispose();
+        
+        // TODO: introduce a way to skip any actual rendering for other targets and only do a dispose?
+        SyncCommit(compositionTarget.Compositor, false);
+    }
+    
+    /// <summary>
+    /// This method schedules a render when something has called RequestCommitAsync
+    /// This can be triggered by user code outside of our normal layout and rendering
+    /// </summary>
+    void ICompositorScheduler.CommitRequested(Compositor compositor)
+    {
+        if(!_requestedCommits.Add(compositor))
+            return;
+
+        // TODO: maybe skip the full render here?
+        ScheduleRender(true);
+    }
+}
\ No newline at end of file
diff --git a/src/Avalonia.Base/Media/MediaContext.cs b/src/Avalonia.Base/Media/MediaContext.cs
new file mode 100644
index 0000000000..0dfe19f55b
--- /dev/null
+++ b/src/Avalonia.Base/Media/MediaContext.cs
@@ -0,0 +1,171 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Avalonia.Animation;
+using Avalonia.Layout;
+using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
+using Avalonia.Rendering.Composition.Transport;
+using Avalonia.Threading;
+
+namespace Avalonia.Media;
+
+internal partial class MediaContext : ICompositorScheduler
+{
+    private DispatcherOperation? _nextRenderOp;
+    private DispatcherOperation? _inputMarkerOp;
+    private TimeSpan _inputMarkerAddedAt;
+    private bool _animationsAreWaitingForComposition;
+    private const double MaxSecondsWithoutInput = 1;
+    private readonly Action _render;
+    private readonly Action _inputMarkerHandler;
+    private readonly HashSet<Compositor> _requestedCommits = new();
+    private readonly Dictionary<Compositor, Batch> _pendingCompositionBatches = new();
+    private record  TopLevelInfo(Compositor Compositor, CompositingRenderer Renderer, ILayoutManager LayoutManager);
+    private readonly HashSet<LayoutManager> _queuedLayoutManagers = new();
+    public static bool InputMarkerEnabled = true;
+
+    private Dictionary<object, TopLevelInfo> _topLevels = new();
+
+    private MediaContext()
+    {
+        _render = Render;
+        _inputMarkerHandler = InputMarkerHandler;
+        _clock = new(this);
+    }
+    
+    public static MediaContext Instance
+    {
+        get
+        {
+            // Technically it's supposed to be a thread-static singleton, but we don't have multiple threads
+            // and need to do a full reset for unit tests
+            var context = AvaloniaLocator.Current.GetService<MediaContext>();
+            if (context == null)
+                AvaloniaLocator.CurrentMutable.Bind<MediaContext>().ToConstant(context = new());
+            return context;
+        }
+    }
+    
+    /// <summary>
+    /// Schedules the next render operation, handles render throttling for input processing
+    /// </summary>
+    private void ScheduleRender(bool now)
+    {
+        // Already scheduled, nothing to do
+        if (_nextRenderOp != null)
+        {
+            if (now)
+                _nextRenderOp.Priority = DispatcherPriority.Render;
+            return;
+        }
+        // Sometimes our animation, layout and render passes might be taking more than a frame to complete
+        // which can cause a "freeze"-like state when UI is being updated, but input is never being processed
+        // So here we inject an operation with Input priority to check if Input wasn't being processed
+        // for a long time. If that's the case the next rendering operation will be scheduled to happen after all pending input
+        
+        var priority = DispatcherPriority.Render;
+        
+        if (InputMarkerEnabled)
+        {
+            if (_inputMarkerOp == null)
+            {
+                _inputMarkerOp = Dispatcher.UIThread.InvokeAsync(_inputMarkerHandler, DispatcherPriority.Input);
+                _inputMarkerAddedAt = _time.Elapsed;
+            }
+            else if (!now && (_time.Elapsed - _inputMarkerAddedAt).TotalSeconds > MaxSecondsWithoutInput)
+            {
+                priority = DispatcherPriority.Input;
+            }
+        }
+
+        _nextRenderOp = Dispatcher.UIThread.InvokeAsync(_render, priority);
+    }
+    
+    /// <summary>
+    /// This handles the _inputMarkerOp message.  We're using
+    /// _inputMarkerOp to determine if input priority dispatcher ops
+    /// have been processes.
+    /// </summary>
+    private void InputMarkerHandler()
+    {
+        //set the marker to null so we know that input priority has been processed
+        _inputMarkerOp = null;
+    }
+
+    private void Render()
+    {
+        try
+        {
+            RenderCore();
+        }
+        finally
+        {
+            _nextRenderOp = null;
+        }
+    }
+    
+    private void RenderCore()
+    {
+        var now = _time.Elapsed;
+        if (!_animationsAreWaitingForComposition)
+            _clock.Pulse(now);
+
+        // Since new animations could be started during the layout and can affect layout/render
+        // We are doing several iterations when it happens
+        for (var c = 0; c < 10; c++)
+        {
+            _clock.HasNewSubscriptions = false;
+            //TODO: Integrate LayoutManager's attempt limit here
+            foreach (var layout in _queuedLayoutManagers.ToArray())
+                layout.ExecuteQueuedLayoutPass();
+            _queuedLayoutManagers.Clear();
+            
+            if (_clock.HasNewSubscriptions)
+            {
+                _clock.Pulse(now);
+                continue;
+            }
+
+            break;
+        }
+
+        // We are currently using compositor commit callbacks to drive animations
+        // Later we should use WPF's approach that asks the animation system for the next tick time
+        // and use some timer if the next animation frame is not needed to be sent to the compositor immediately
+        if (_requestedCommits.Count > 0 || _clock.HasSubscriptions)
+        {
+            _animationsAreWaitingForComposition = true;
+            CommitCompositorsWithThrottling();
+        }
+    }
+
+    // Used for unit tests
+    public bool IsTopLevelActive(object key) => _topLevels.ContainsKey(key);
+
+    public void AddTopLevel(object key, ILayoutManager layoutManager, IRenderer renderer)
+    {
+        if(_topLevels.ContainsKey(key))
+            return;
+        var render = (CompositingRenderer)renderer;
+        _topLevels.Add(key, new TopLevelInfo(render.Compositor, render, layoutManager));
+        render.Start();
+        ScheduleRender(true);
+    }
+
+    public void RemoveTopLevel(object key)
+    {
+        if (_topLevels.TryGetValue(key, out var info))
+        {
+            _topLevels.Remove(key);
+            info.Renderer.Stop();
+        }
+    }
+
+    public void QueueLayoutPass(LayoutManager layoutManager)
+    {
+        _queuedLayoutManagers.Add(layoutManager);
+        ScheduleRender(true);
+    }
+}
\ No newline at end of file
diff --git a/src/Avalonia.Base/Media/RotateTransform.cs b/src/Avalonia.Base/Media/RotateTransform.cs
index ab3ea6770f..b02a111939 100644
--- a/src/Avalonia.Base/Media/RotateTransform.cs
+++ b/src/Avalonia.Base/Media/RotateTransform.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Rotates an <see cref="Visual"/>.
     /// </summary>
-    public class RotateTransform : Transform
+    public sealed class RotateTransform : Transform
     {
         /// <summary>
         /// Defines the <see cref="Angle"/> property.
diff --git a/src/Avalonia.Base/Media/ScaleTransform.cs b/src/Avalonia.Base/Media/ScaleTransform.cs
index fca2f4bf2a..6aac15f604 100644
--- a/src/Avalonia.Base/Media/ScaleTransform.cs
+++ b/src/Avalonia.Base/Media/ScaleTransform.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Scale an <see cref="Visual"/>.
     /// </summary>
-    public class ScaleTransform : Transform
+    public sealed class ScaleTransform : Transform
     {
         /// <summary>
         /// Defines the <see cref="ScaleX"/> property.
diff --git a/src/Avalonia.Base/Media/SkewTransform.cs b/src/Avalonia.Base/Media/SkewTransform.cs
index d268bee778..2019f24444 100644
--- a/src/Avalonia.Base/Media/SkewTransform.cs
+++ b/src/Avalonia.Base/Media/SkewTransform.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Skews an <see cref="Visual"/>.
     /// </summary>
-    public class SkewTransform : Transform
+    public sealed class SkewTransform : Transform
     {
         /// <summary>
         /// Defines the <see cref="AngleX"/> property.
diff --git a/src/Avalonia.Base/Media/SolidColorBrush.cs b/src/Avalonia.Base/Media/SolidColorBrush.cs
index a552e262ae..4ba60e9506 100644
--- a/src/Avalonia.Base/Media/SolidColorBrush.cs
+++ b/src/Avalonia.Base/Media/SolidColorBrush.cs
@@ -10,7 +10,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Fills an area with a solid color.
     /// </summary>
-    public class SolidColorBrush : Brush, ISolidColorBrush, IMutableBrush
+    public sealed class SolidColorBrush : Brush, ISolidColorBrush, IMutableBrush
     {
         /// <summary>
         /// Defines the <see cref="Color"/> property.
diff --git a/src/Avalonia.Base/Media/TileBrush.cs b/src/Avalonia.Base/Media/TileBrush.cs
index 47a617a4fb..b248d30410 100644
--- a/src/Avalonia.Base/Media/TileBrush.cs
+++ b/src/Avalonia.Base/Media/TileBrush.cs
@@ -41,6 +41,11 @@ namespace Avalonia.Media
     /// </summary>
     public abstract class TileBrush : Brush, ITileBrush
     {
+        internal TileBrush()
+        {
+            
+        }
+        
         /// <summary>
         /// Defines the <see cref="AlignmentX"/> property.
         /// </summary>
diff --git a/src/Avalonia.Base/Media/Transform.cs b/src/Avalonia.Base/Media/Transform.cs
index 2934291626..1ac81808a1 100644
--- a/src/Avalonia.Base/Media/Transform.cs
+++ b/src/Avalonia.Base/Media/Transform.cs
@@ -21,6 +21,11 @@ namespace Avalonia.Media
                 typeof(ITransform).IsAssignableFrom(prop.OwnerType));
         }
 
+        internal Transform()
+        {
+            
+        }
+
         /// <summary>
         /// Raised when the transform changes.
         /// </summary>
diff --git a/src/Avalonia.Base/Media/TransformGroup.cs b/src/Avalonia.Base/Media/TransformGroup.cs
index ae5e54c414..38069f783a 100644
--- a/src/Avalonia.Base/Media/TransformGroup.cs
+++ b/src/Avalonia.Base/Media/TransformGroup.cs
@@ -3,7 +3,7 @@ using Avalonia.Metadata;
 
 namespace Avalonia.Media
 {
-    public class TransformGroup : Transform
+    public sealed class TransformGroup : Transform
     {
         /// <summary>
         /// Defines the <see cref="Children"/> property.
diff --git a/src/Avalonia.Base/Media/TranslateTransform.cs b/src/Avalonia.Base/Media/TranslateTransform.cs
index 1d0169a62c..34cebe9150 100644
--- a/src/Avalonia.Base/Media/TranslateTransform.cs
+++ b/src/Avalonia.Base/Media/TranslateTransform.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Translates (moves) an <see cref="Visual"/>.
     /// </summary>
-    public class TranslateTransform : Transform
+    public sealed class TranslateTransform : Transform
     {
         /// <summary>
         /// Defines the <see cref="X"/> property.
diff --git a/src/Avalonia.Base/Media/VisualBrush.cs b/src/Avalonia.Base/Media/VisualBrush.cs
index a1be9a9202..2b604d684f 100644
--- a/src/Avalonia.Base/Media/VisualBrush.cs
+++ b/src/Avalonia.Base/Media/VisualBrush.cs
@@ -12,7 +12,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Paints an area with an <see cref="Visual"/>.
     /// </summary>
-    public class VisualBrush : TileBrush, ISceneBrush
+    public sealed class VisualBrush : TileBrush, ISceneBrush
     {
         /// <summary>
         /// Defines the <see cref="Visual"/> property.
diff --git a/src/Avalonia.Base/Metadata/PrivateApiAttribute.cs b/src/Avalonia.Base/Metadata/PrivateApiAttribute.cs
index 8848a6b629..70f24f815a 100644
--- a/src/Avalonia.Base/Metadata/PrivateApiAttribute.cs
+++ b/src/Avalonia.Base/Metadata/PrivateApiAttribute.cs
@@ -2,7 +2,8 @@ using System;
 
 namespace Avalonia.Metadata;
 
-[AttributeUsage(AttributeTargets.Interface | AttributeTargets.Class | AttributeTargets.Constructor | AttributeTargets.Method)]
+[AttributeUsage(AttributeTargets.Interface | AttributeTargets.Class | AttributeTargets.Constructor 
+                | AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.Field)]
 public sealed class PrivateApiAttribute : Attribute
 {
 
diff --git a/src/Avalonia.Base/Rendering/Composition/CompositingRenderer.cs b/src/Avalonia.Base/Rendering/Composition/CompositingRenderer.cs
index b6fe265531..61a3f7e831 100644
--- a/src/Avalonia.Base/Rendering/Composition/CompositingRenderer.cs
+++ b/src/Avalonia.Base/Rendering/Composition/CompositingRenderer.cs
@@ -17,7 +17,7 @@ namespace Avalonia.Rendering.Composition;
 /// <summary>
 /// A renderer that utilizes <see cref="Avalonia.Rendering.Composition.Compositor"/> to render the visual tree 
 /// </summary>
-public class CompositingRenderer : IRendererWithCompositor
+internal class CompositingRenderer : IRendererWithCompositor, IHitTester
 {
     private readonly IRenderRoot _root;
     private readonly Compositor _compositor;
@@ -32,11 +32,6 @@ public class CompositingRenderer : IRendererWithCompositor
 
     internal CompositionTarget CompositionTarget { get; }
     
-    /// <summary>
-    /// Asks the renderer to only draw frames on the render thread. Makes Paint to wait until frame is rendered.
-    /// </summary>
-    public bool RenderOnlyOnRenderThread { get; set; } = true;
-
     /// <inheritdoc/>
     public RendererDiagnostics Diagnostics { get; }
 
@@ -303,6 +298,9 @@ public class CompositingRenderer : IRendererWithCompositor
         await batchCompletion;
         SceneInvalidated?.Invoke(this, new SceneInvalidatedEventArgs(_root, new Rect(_root.ClientSize)));
     }
+
+    public void TriggerSceneInvalidatedForUnitTests(Rect rect) =>
+        SceneInvalidated?.Invoke(this, new SceneInvalidatedEventArgs(_root, rect));
     
     private void Update()
     {
@@ -332,10 +330,7 @@ public class CompositingRenderer : IRendererWithCompositor
 
         QueueUpdate();
         CompositionTarget.RequestRedraw();
-        if(RenderOnlyOnRenderThread && Compositor.Loop.RunsInBackground)
-            Compositor.Commit().Wait();
-        else
-            CompositionTarget.ImmediateUIThreadRender();
+        MediaContext.Instance.ImmediateRenderRequested(CompositionTarget);
     }
 
     /// <inheritdoc />
@@ -355,6 +350,8 @@ public class CompositingRenderer : IRendererWithCompositor
     public ValueTask<object?> TryGetRenderInterfaceFeature(Type featureType)
         => Compositor.TryGetRenderInterfaceFeature(featureType);
 
+    public bool IsDisposed => _isDisposed;
+    
     /// <inheritdoc />
     public void Dispose()
     {
@@ -367,11 +364,7 @@ public class CompositingRenderer : IRendererWithCompositor
         SceneInvalidated = null;
 
         Stop();
-        CompositionTarget.Dispose();
-        
-        // Wait for the composition batch to be applied and rendered to guarantee that
-        // render target is not used anymore and can be safely disposed
-        if (Compositor.Loop.RunsInBackground)
-            _compositor.Commit().Wait();
+
+        MediaContext.Instance.SyncDisposeCompositionTarget(CompositionTarget);
     }
 }
diff --git a/src/Avalonia.Base/Rendering/Composition/CompositionTarget.cs b/src/Avalonia.Base/Rendering/Composition/CompositionTarget.cs
index 492ea774bc..91d2fb59de 100644
--- a/src/Avalonia.Base/Rendering/Composition/CompositionTarget.cs
+++ b/src/Avalonia.Base/Rendering/Composition/CompositionTarget.cs
@@ -122,14 +122,5 @@ namespace Avalonia.Rendering.Composition
         /// Registers the composition target for explicit redraw
         /// </summary>
         public void RequestRedraw() => RegisterForSerialization();
-
-        /// <summary>
-        /// Performs composition directly on the UI thread 
-        /// </summary>
-        internal void ImmediateUIThreadRender()
-        {
-            Compositor.Commit();
-            Compositor.Server.Render();
-        }
     }
 }
diff --git a/src/Avalonia.Base/Rendering/Composition/Compositor.cs b/src/Avalonia.Base/Rendering/Composition/Compositor.cs
index a2398fdb61..0a4b7be15e 100644
--- a/src/Avalonia.Base/Rendering/Composition/Compositor.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Compositor.cs
@@ -25,25 +25,39 @@ namespace Avalonia.Rendering.Composition
     public partial class Compositor
     {
         internal IRenderLoop Loop { get; }
+        internal bool UseUiThreadForSynchronousCommits { get; }
         private ServerCompositor _server;
-        private TaskCompletionSource<int>? _nextCommit;
-        private Action _commit;
-        private BatchStreamObjectPool<object?> _batchObjectPool = new();
-        private BatchStreamMemoryPool _batchMemoryPool = new();
+        private Batch? _nextCommit;
+        private BatchStreamObjectPool<object?> _batchObjectPool;
+        private BatchStreamMemoryPool _batchMemoryPool;
         private Queue<ICompositorSerializable> _objectSerializationQueue = new();
         private HashSet<ICompositorSerializable> _objectSerializationHashSet = new();
         private Queue<Action> _invokeBeforeCommitWrite = new(), _invokeBeforeCommitRead = new();
         private HashSet<IDisposable> _disposeOnNextBatch = new();
         internal ServerCompositor Server => _server;
-        private Task? _pendingBatch;
+        private Batch? _pendingBatch;
         private readonly object _pendingBatchLock = new();
         private List<Action> _pendingServerCompositorJobs = new();
         private DiagnosticTextRenderer? _diagnosticTextRenderer;
+        private Action _triggerCommitRequested;
 
         internal IEasing DefaultEasing { get; }
 
-        private DiagnosticTextRenderer DiagnosticTextRenderer
-            => _diagnosticTextRenderer ??= new(Typeface.Default.GlyphTypeface, 12.0);
+        private DiagnosticTextRenderer? DiagnosticTextRenderer
+        {
+            get
+            {
+                if (_diagnosticTextRenderer == null)
+                {
+                    // We are running in some unit test context
+                    if (AvaloniaLocator.Current.GetService<IFontManagerImpl>() == null)
+                        return null;
+                    _diagnosticTextRenderer = new(Typeface.Default.GlyphTypeface, 12.0);
+                }
+
+                return _diagnosticTextRenderer;
+            }
+        }
 
         internal event Action? AfterCommit;
 
@@ -51,14 +65,29 @@ namespace Avalonia.Rendering.Composition
         /// <summary>
         /// Creates a new compositor on a specified render loop that would use a particular GPU
         /// </summary>
-        /// <param name="loop"></param>
-        /// <param name="gpu"></param>
         [PrivateApi]
-        public Compositor(IRenderLoop loop, IPlatformGraphics? gpu)
+        public Compositor(IPlatformGraphics? gpu, bool useUiThreadForSynchronousCommits = false) 
+            : this(RenderLoop.LocatorAutoInstance, gpu, useUiThreadForSynchronousCommits)
+        {
+            
+        }
+        
+        internal Compositor(IRenderLoop loop, IPlatformGraphics? gpu, bool useUiThreadForSynchronousCommits = false) 
+            : this(loop, gpu, useUiThreadForSynchronousCommits, MediaContext.Instance, false)
+        {
+            
+        }
+
+        internal Compositor(IRenderLoop loop, IPlatformGraphics? gpu,
+            bool useUiThreadForSynchronousCommits,
+            ICompositorScheduler scheduler, bool reclaimBuffersImmediately)
         {
             Loop = loop;
+            UseUiThreadForSynchronousCommits = useUiThreadForSynchronousCommits;
+            _batchMemoryPool = new(reclaimBuffersImmediately);
+            _batchObjectPool = new(reclaimBuffersImmediately);
             _server = new ServerCompositor(loop, gpu, _batchObjectPool, _batchMemoryPool);
-            _commit = () => Commit();
+            _triggerCommitRequested = () => scheduler.CommitRequested(this);
 
             DefaultEasing = new CubicBezierEasing(new Point(0.25f, 0.1f), new Point(0.25f, 1f));
         }
@@ -72,23 +101,19 @@ namespace Avalonia.Rendering.Composition
             Dispatcher.UIThread.VerifyAccess();
             if (_nextCommit == null)
             {
-                _nextCommit = new TaskCompletionSource<int>();
+                _nextCommit = new ();
                 var pending = _pendingBatch;
                 if (pending != null)
-                {
-                    pending.ContinueWith(_ =>
-                    {
-                        Dispatcher.UIThread.Post(_commit, DispatcherPriority.Composition);
-                    });
-                }
+                    pending.Processed.ContinueWith(
+                        _ => Dispatcher.UIThread.Post(_triggerCommitRequested, DispatcherPriority.Send));
                 else
-                    Dispatcher.UIThread.Post(_commit, DispatcherPriority.Composition);
+                    _triggerCommitRequested();
             }
 
-            return _nextCommit.Task;
+            return _nextCommit.Processed;
         }
 
-        internal Task Commit()
+        internal Batch Commit()
         {
             try
             {
@@ -102,20 +127,18 @@ namespace Avalonia.Rendering.Composition
             }
         }
         
-        Task CommitCore()
+        Batch CommitCore()
         {
             Dispatcher.UIThread.VerifyAccess();
             using var noPump = NonPumpingLockHelper.Use();
             
-            _nextCommit ??= new TaskCompletionSource<int>();
+            _nextCommit ??= new();
 
             (_invokeBeforeCommitRead, _invokeBeforeCommitWrite) = (_invokeBeforeCommitWrite, _invokeBeforeCommitRead);
             while (_invokeBeforeCommitRead.Count > 0)
                 _invokeBeforeCommitRead.Dequeue()();
             
-            var batch = new Batch(_nextCommit);
-            
-            using (var writer = new BatchStreamWriter(batch.Changes, _batchMemoryPool, _batchObjectPool))
+            using (var writer = new BatchStreamWriter(_nextCommit.Changes, _batchMemoryPool, _batchObjectPool))
             {
                 while(_objectSerializationQueue.TryDequeue(out var obj))
                 {
@@ -151,17 +174,17 @@ namespace Avalonia.Rendering.Composition
                 _pendingServerCompositorJobs.Clear();
             }
             
-            batch.CommittedAt = Server.Clock.Elapsed;
-            _server.EnqueueBatch(batch);
+            _nextCommit.CommittedAt = Server.Clock.Elapsed;
+            _server.EnqueueBatch(_nextCommit);
             
             lock (_pendingBatchLock)
             {
-                _pendingBatch = _nextCommit.Task;
-                _pendingBatch.ContinueWith(t =>
+                _pendingBatch = _nextCommit;
+                _pendingBatch.Processed.ContinueWith(t =>
                 {
                     lock (_pendingBatchLock)
                     {
-                        if (_pendingBatch == t)
+                        if (_pendingBatch.Processed == t)
                             _pendingBatch = null;
                     }
                 }, TaskContinuationOptions.ExecuteSynchronously);
@@ -257,4 +280,9 @@ namespace Avalonia.Rendering.Composition
         internal bool UnitTestIsRegisteredForSerialization(ICompositorSerializable serializable) =>
             _objectSerializationHashSet.Contains(serializable);
     }
+    
+    internal interface ICompositorScheduler
+    {
+        void CommitRequested(Compositor compositor);
+    }
 }
diff --git a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionTarget.cs b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionTarget.cs
index 4f6564ebcf..7672bcb14d 100644
--- a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionTarget.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionTarget.cs
@@ -21,7 +21,7 @@ namespace Avalonia.Rendering.Composition.Server
     {
         private readonly ServerCompositor _compositor;
         private readonly Func<IEnumerable<object>> _surfaces;
-        private readonly DiagnosticTextRenderer _diagnosticTextRenderer;
+        private readonly DiagnosticTextRenderer? _diagnosticTextRenderer;
         private static long s_nextId = 1;
         private IRenderTarget? _renderTarget;
         private FpsCounter? _fpsCounter;
@@ -42,17 +42,17 @@ namespace Avalonia.Rendering.Composition.Server
         public ReadbackIndices Readback { get; } = new();
         public int RenderedVisuals { get; set; }
 
-        private FpsCounter FpsCounter
-            => _fpsCounter ??= new FpsCounter(_diagnosticTextRenderer);
+        private FpsCounter? FpsCounter
+            => _fpsCounter ??= _diagnosticTextRenderer != null ? new FpsCounter(_diagnosticTextRenderer) : null;
 
-        private FrameTimeGraph LayoutTimeGraph
+        private FrameTimeGraph? LayoutTimeGraph
             => _layoutTimeGraph ??= CreateTimeGraph("Layout");
 
-        private FrameTimeGraph RenderTimeGraph
+        private FrameTimeGraph? RenderTimeGraph
             => _renderTimeGraph ??= CreateTimeGraph("Render");
 
         public ServerCompositionTarget(ServerCompositor compositor, Func<IEnumerable<object>> surfaces,
-            DiagnosticTextRenderer diagnosticTextRenderer)
+            DiagnosticTextRenderer? diagnosticTextRenderer)
             : base(compositor)
         {
             _compositor = compositor;
@@ -61,8 +61,12 @@ namespace Avalonia.Rendering.Composition.Server
             Id = Interlocked.Increment(ref s_nextId);
         }
 
-        private FrameTimeGraph CreateTimeGraph(string title)
-            => new(360, new Size(360.0, 64.0), 1000.0 / 60.0, title, _diagnosticTextRenderer);
+        private FrameTimeGraph? CreateTimeGraph(string title)
+        {
+            if (_diagnosticTextRenderer == null)
+                return null;
+            return new FrameTimeGraph(360, new Size(360.0, 64.0), 1000.0 / 60.0, title, _diagnosticTextRenderer);
+        }
 
         partial void OnIsEnabledChanged()
         {
@@ -102,7 +106,7 @@ namespace Avalonia.Rendering.Composition.Server
         {
             if ((DebugOverlays & RendererDebugOverlays.LayoutTimeGraph) != 0)
             {
-                LayoutTimeGraph.AddFrameValue(LastLayoutPassTiming.Elapsed.TotalMilliseconds);
+                LayoutTimeGraph?.AddFrameValue(LastLayoutPassTiming.Elapsed.TotalMilliseconds);
             }
         }
 
@@ -188,7 +192,7 @@ namespace Avalonia.Rendering.Composition.Server
                     if (captureTiming)
                     {
                         var elapsed = StopwatchHelper.GetElapsedTime(startingTimestamp);
-                        RenderTimeGraph.AddFrameValue(elapsed.TotalMilliseconds);
+                        RenderTimeGraph?.AddFrameValue(elapsed.TotalMilliseconds);
                     }
 
                     DrawOverlays(targetContext);
@@ -220,14 +224,16 @@ namespace Avalonia.Rendering.Composition.Server
                     (Compositor.BatchObjectPool.CurrentUsage + Compositor.BatchObjectPool.CurrentPool) *
                     Compositor.BatchObjectPool.ArraySize *
                     IntPtr.Size), false);
-                FpsCounter.RenderFps(targetContext,
+                FpsCounter?.RenderFps(targetContext,
                     FormattableString.Invariant($"M:{managedMem} / N:{nativeMem} R:{RenderedVisuals:0000}"));
             }
 
             var top = 0.0;
 
-            void DrawTimeGraph(FrameTimeGraph graph)
+            void DrawTimeGraph(FrameTimeGraph? graph)
             {
+                if (graph == null)
+                    return;
                 top += 8.0;
                 targetContext.Transform = Matrix.CreateTranslation(Size.Width - graph.Size.Width - 8.0, top);
                 graph.Render(targetContext);
diff --git a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositor.cs b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositor.cs
index 8652ef223c..38969fa582 100644
--- a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositor.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositor.cs
@@ -57,7 +57,8 @@ namespace Avalonia.Rendering.Composition.Server
 
         internal void UpdateServerTime() => ServerNow = Clock.Elapsed;
 
-        List<Batch> _reusableToCompleteList = new();
+        List<Batch> _reusableToNotifyProcessedList = new();
+        List<Batch> _reusableToNotifyRenderedList = new();
         void ApplyPendingBatches()
         {
             while (true)
@@ -100,7 +101,7 @@ namespace Avalonia.Rendering.Composition.Server
                     }
                 }
 
-                _reusableToCompleteList.Add(batch);
+                _reusableToNotifyProcessedList.Add(batch);
                 LastBatchId = batch.SequenceId;
             }
         }
@@ -135,17 +136,23 @@ namespace Avalonia.Rendering.Composition.Server
                 }
         }
 
-        void CompletePendingBatches()
+        void NotifyBatchesProcessed()
         {
-            foreach(var batch in _reusableToCompleteList)
-                batch.Complete();
-            _reusableToCompleteList.Clear();
-        }
+            foreach (var batch in _reusableToNotifyProcessedList) 
+                batch.NotifyProcessed();
 
-        bool IRenderLoopTask.NeedsUpdate => false;
+            foreach (var batch in _reusableToNotifyProcessedList)
+                _reusableToNotifyRenderedList.Add(batch);
 
-        void IRenderLoopTask.Update(TimeSpan time)
+            _reusableToNotifyProcessedList.Clear();
+        }
+        
+        void NotifyBatchesRendered()
         {
+            foreach (var batch in _reusableToNotifyRenderedList) 
+                batch.NotifyRendered();
+
+            _reusableToNotifyRenderedList.Clear();
         }
 
         public void Render()
@@ -159,8 +166,10 @@ namespace Avalonia.Rendering.Composition.Server
                 }
                 finally
                 {
+                    NotifyBatchesRendered();
                     _safeThread = null;
                 }
+                
             }
         }
         
@@ -168,7 +177,7 @@ namespace Avalonia.Rendering.Composition.Server
         {
             UpdateServerTime();
             ApplyPendingBatches();
-            CompletePendingBatches();
+            NotifyBatchesProcessed();
             
             foreach(var animation in _clockItems)
                 _clockItemsToUpdate.Add(animation);
diff --git a/src/Avalonia.Base/Rendering/Composition/Transport/Batch.cs b/src/Avalonia.Base/Rendering/Composition/Transport/Batch.cs
index 803ea809c0..992e5ba7b9 100644
--- a/src/Avalonia.Base/Rendering/Composition/Transport/Batch.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Transport/Batch.cs
@@ -15,12 +15,13 @@ namespace Avalonia.Rendering.Composition.Transport
     {
         private static long _nextSequenceId = 1;
         private static ConcurrentBag<BatchStreamData> _pool = new();
-        private readonly TaskCompletionSource<int>? _tcs;
+        private readonly TaskCompletionSource<int> _acceptedTcs = new();
+        private readonly TaskCompletionSource<int> _renderedTcs = new();
+        
         public long SequenceId { get; }
         
-        public Batch(TaskCompletionSource<int>? tcs)
+        public Batch()
         {
-            _tcs = tcs;
             SequenceId = Interlocked.Increment(ref _nextSequenceId);
             if (!_pool.TryTake(out var lst))
                 lst = new BatchStreamData();
@@ -30,14 +31,17 @@ namespace Avalonia.Rendering.Composition.Transport
         
         public BatchStreamData Changes { get; private set; }
         public TimeSpan CommittedAt { get; set; }
+        public Task Processed => _acceptedTcs.Task;
+        public Task Rendered => _renderedTcs.Task;
         
-        public void Complete()
+        public void NotifyProcessed()
         {
             _pool.Add(Changes);
             Changes = null!;
 
-            _tcs?.TrySetResult(0);
+            _acceptedTcs.TrySetResult(0);
         }
-
+        
+        public void NotifyRendered() => _renderedTcs.TrySetResult(0);
     }
 }
diff --git a/src/Avalonia.Base/Rendering/Composition/Transport/BatchStreamArrayPool.cs b/src/Avalonia.Base/Rendering/Composition/Transport/BatchStreamArrayPool.cs
index 8916983a5c..222e9918d2 100644
--- a/src/Avalonia.Base/Rendering/Composition/Transport/BatchStreamArrayPool.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Transport/BatchStreamArrayPool.cs
@@ -24,14 +24,17 @@ internal abstract class BatchStreamPoolBase<T> : IDisposable
     public int CurrentUsage => _usage;
     public int CurrentPool => _pool.Count;
 
-    public BatchStreamPoolBase(bool needsFinalize, Action<Func<bool>>? startTimer = null)
+    public BatchStreamPoolBase(bool needsFinalize, bool reclaimImmediately, Action<Func<bool>>? startTimer = null)
     {
         if(!needsFinalize)
             GC.SuppressFinalize(needsFinalize);
 
         var updateRef = new WeakReference<BatchStreamPoolBase<T>>(this);
-        if (AvaloniaLocator.Current.GetService<IPlatformThreadingInterface>() == null
-            && AvaloniaLocator.Current.GetService<IDispatcherImpl>() == null)
+        if (
+            reclaimImmediately 
+            || (
+            AvaloniaLocator.Current.GetService<IPlatformThreadingInterface>() == null
+            && AvaloniaLocator.Current.GetService<IDispatcherImpl>() == null))
             _reclaimImmediately = true;
         else
             StartUpdateTimer(startTimer, updateRef);
@@ -134,7 +137,8 @@ internal sealed class BatchStreamObjectPool<T> : BatchStreamPoolBase<T[]> where
 {
     public int ArraySize { get; }
 
-    public BatchStreamObjectPool(int arraySize = 128, Action<Func<bool>>? startTimer = null) : base(false, startTimer)
+    public BatchStreamObjectPool(bool reclaimImmediately = false, int arraySize = 128, Action<Func<bool>>? startTimer = null) 
+        : base(false, reclaimImmediately, startTimer)
     {
         ArraySize = arraySize;
     }
@@ -154,7 +158,8 @@ internal sealed class BatchStreamMemoryPool : BatchStreamPoolBase<IntPtr>
 {
     public int BufferSize { get; }
 
-    public BatchStreamMemoryPool(int bufferSize = 1024, Action<Func<bool>>? startTimer = null) : base(true, startTimer)
+    public BatchStreamMemoryPool(bool reclaimImmediately, int bufferSize = 1024, Action<Func<bool>>? startTimer = null) 
+        : base(true, reclaimImmediately, startTimer)
     {
         BufferSize = bufferSize;
     }
diff --git a/src/Avalonia.Base/Rendering/IRenderLoop.cs b/src/Avalonia.Base/Rendering/IRenderLoop.cs
index ebe683949d..bf2c221b03 100644
--- a/src/Avalonia.Base/Rendering/IRenderLoop.cs
+++ b/src/Avalonia.Base/Rendering/IRenderLoop.cs
@@ -10,7 +10,7 @@ namespace Avalonia.Rendering
     /// graph for visible windows.
     /// </remarks>
     [NotClientImplementable]
-    public interface IRenderLoop
+    internal interface IRenderLoop
     {
         /// <summary>
         /// Adds an update task.
diff --git a/src/Avalonia.Base/Rendering/IRenderLoopTask.cs b/src/Avalonia.Base/Rendering/IRenderLoopTask.cs
index 15f0afc797..f63855e651 100644
--- a/src/Avalonia.Base/Rendering/IRenderLoopTask.cs
+++ b/src/Avalonia.Base/Rendering/IRenderLoopTask.cs
@@ -3,10 +3,8 @@ using System.Threading.Tasks;
 
 namespace Avalonia.Rendering
 {
-    public interface IRenderLoopTask
+    internal interface IRenderLoopTask
     {
-        bool NeedsUpdate { get; }
-        void Update(TimeSpan time);
         void Render();
     }
 }
diff --git a/src/Avalonia.Base/Rendering/IRenderRoot.cs b/src/Avalonia.Base/Rendering/IRenderRoot.cs
index 09df7b7830..371d34b1f4 100644
--- a/src/Avalonia.Base/Rendering/IRenderRoot.cs
+++ b/src/Avalonia.Base/Rendering/IRenderRoot.cs
@@ -16,7 +16,9 @@ namespace Avalonia.Rendering
         /// <summary>
         /// Gets the renderer for the window.
         /// </summary>
-        IRenderer Renderer { get; }
+        internal IRenderer Renderer { get; }
+        
+        internal IHitTester HitTester { get; }
 
         /// <summary>
         /// The scaling factor to use in rendering.
diff --git a/src/Avalonia.Base/Rendering/IRenderer.cs b/src/Avalonia.Base/Rendering/IRenderer.cs
index 7e32504e17..4cb79d803d 100644
--- a/src/Avalonia.Base/Rendering/IRenderer.cs
+++ b/src/Avalonia.Base/Rendering/IRenderer.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using Avalonia.Metadata;
 using Avalonia.Rendering.Composition;
 
 namespace Avalonia.Rendering
@@ -8,7 +9,7 @@ namespace Avalonia.Rendering
     /// <summary>
     /// Defines the interface for a renderer.
     /// </summary>
-    public interface IRenderer : IDisposable
+    internal interface IRenderer : IDisposable
     {
         /// <summary>
         /// Gets a value indicating whether the renderer should draw specific diagnostics.
@@ -29,31 +30,7 @@ namespace Avalonia.Rendering
         /// </summary>
         /// <param name="visual">The visual.</param>
         void AddDirty(Visual visual);
-
-        /// <summary>
-        /// Hit tests a location to find the visuals at the specified point.
-        /// </summary>
-        /// <param name="p">The point, in client coordinates.</param>
-        /// <param name="root">The root of the subtree to search.</param>
-        /// <param name="filter">
-        /// A filter predicate. If the predicate returns false then the visual and all its
-        /// children will be excluded from the results.
-        /// </param>
-        /// <returns>The visuals at the specified point, topmost first.</returns>
-        IEnumerable<Visual> HitTest(Point p, Visual root, Func<Visual, bool> filter);
-
-        /// <summary>
-        /// Hit tests a location to find first visual at the specified point.
-        /// </summary>
-        /// <param name="p">The point, in client coordinates.</param>
-        /// <param name="root">The root of the subtree to search.</param>
-        /// <param name="filter">
-        /// A filter predicate. If the predicate returns false then the visual and all its
-        /// children will be excluded from the results.
-        /// </param>
-        /// <returns>The visual at the specified point, topmost first.</returns>
-        Visual? HitTestFirst(Point p, Visual root, Func<Visual, bool> filter);
-
+        
         /// <summary>
         /// Informs the renderer that the z-ordering of a visual's children has changed.
         /// </summary>
@@ -88,11 +65,38 @@ namespace Avalonia.Rendering
         public ValueTask<object?> TryGetRenderInterfaceFeature(Type featureType);
     }
     
-    public interface IRendererWithCompositor : IRenderer
+    internal interface IRendererWithCompositor : IRenderer
     {
         /// <summary>
         /// The associated <see cref="Avalonia.Rendering.Composition.Compositor"/> object
         /// </summary>
         Compositor Compositor { get; }
     }
+
+    internal interface IHitTester
+    {
+        /// <summary>
+        /// Hit tests a location to find the visuals at the specified point.
+        /// </summary>
+        /// <param name="p">The point, in client coordinates.</param>
+        /// <param name="root">The root of the subtree to search.</param>
+        /// <param name="filter">
+        /// A filter predicate. If the predicate returns false then the visual and all its
+        /// children will be excluded from the results.
+        /// </param>
+        /// <returns>The visuals at the specified point, topmost first.</returns>
+        IEnumerable<Visual> HitTest(Point p, Visual root, Func<Visual, bool> filter);
+
+        /// <summary>
+        /// Hit tests a location to find first visual at the specified point.
+        /// </summary>
+        /// <param name="p">The point, in client coordinates.</param>
+        /// <param name="root">The root of the subtree to search.</param>
+        /// <param name="filter">
+        /// A filter predicate. If the predicate returns false then the visual and all its
+        /// children will be excluded from the results.
+        /// </param>
+        /// <returns>The visual at the specified point, topmost first.</returns>
+        Visual? HitTestFirst(Point p, Visual root, Func<Visual, bool> filter);
+    }
 }
diff --git a/src/Avalonia.Base/Rendering/RenderLoop.cs b/src/Avalonia.Base/Rendering/RenderLoop.cs
index 185f44d29a..aaecf5deaf 100644
--- a/src/Avalonia.Base/Rendering/RenderLoop.cs
+++ b/src/Avalonia.Base/Rendering/RenderLoop.cs
@@ -14,33 +14,38 @@ namespace Avalonia.Rendering
     /// The render loop is responsible for advancing the animation timer and updating the scene
     /// graph for visible windows.
     /// </remarks>
-    public class RenderLoop : IRenderLoop
+    internal class RenderLoop : IRenderLoop
     {
-        private readonly IDispatcher _dispatcher;
         private List<IRenderLoopTask> _items = new List<IRenderLoopTask>();
         private List<IRenderLoopTask> _itemsCopy = new List<IRenderLoopTask>();
-        private List<IRenderLoopTask> _updateItemsCopy = new List<IRenderLoopTask>();
         private IRenderTimer? _timer;
         private int _inTick;
         private int _inUpdate;
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="RenderLoop"/> class.
-        /// </summary>
-        public RenderLoop()
+        
+        public static IRenderLoop LocatorAutoInstance
         {
-            _dispatcher = Dispatcher.UIThread;
-        }
+            get
+            {
+                var loop = AvaloniaLocator.Current.GetService<IRenderLoop>();
+                if (loop == null)
+                {
+                    var timer = AvaloniaLocator.Current.GetRequiredService<IRenderTimer>();
+                    AvaloniaLocator.CurrentMutable.Bind<IRenderLoop>()
+                        .ToConstant(loop = new RenderLoop(timer));
+                }
 
+                return loop;
+            }
+        }
+        
         /// <summary>
         /// Initializes a new instance of the <see cref="RenderLoop"/> class.
         /// </summary>
         /// <param name="timer">The render timer.</param>
         /// <param name="dispatcher">The UI thread dispatcher.</param>
-        public RenderLoop(IRenderTimer timer, IDispatcher dispatcher)
+        public RenderLoop(IRenderTimer timer)
         {
             _timer = timer;
-            _dispatcher = dispatcher;
         }
 
         /// <summary>
@@ -96,53 +101,13 @@ namespace Avalonia.Rendering
             {
                 try
                 {
-                    bool needsUpdate = false;
-
+                    
                     lock (_items)
                     {
                         _itemsCopy.Clear();
                         _itemsCopy.AddRange(_items);
                     }
                     
-                    foreach (IRenderLoopTask item in _itemsCopy)
-                    {
-                        if (item.NeedsUpdate)
-                        {
-                            needsUpdate = true;
-
-                            break;
-                        }
-                    }
-
-                    if (needsUpdate &&
-                        Interlocked.CompareExchange(ref _inUpdate, 1, 0) == 0)
-                    {
-                        _dispatcher.Post(() =>
-                        {
-                            lock (_items)
-                            {
-                                _updateItemsCopy.Clear();
-                                _updateItemsCopy.AddRange(_items);
-                            }
-                            foreach (var item in _updateItemsCopy)
-                            {
-                                if (item.NeedsUpdate)
-                                {
-                                    try
-                                    {
-                                        item.Update(time);
-                                    }
-                                    catch (Exception ex)
-                                    {
-                                        Logger.TryGet(LogEventLevel.Error, LogArea.Visual)?.Log(this, "Exception in render update: {Error}", ex);
-                                    }
-                                }
-                            }
-                            _updateItemsCopy.Clear();
-
-                            Interlocked.Exchange(ref _inUpdate, 0);
-                        }, DispatcherPriority.Render);
-                    }
 
                     for (int i = 0; i < _itemsCopy.Count; i++)
                     {
diff --git a/src/Avalonia.Base/Rendering/UiThreadRenderTimer.cs b/src/Avalonia.Base/Rendering/UiThreadRenderTimer.cs
index 7f2eedc98c..c50f8870a0 100644
--- a/src/Avalonia.Base/Rendering/UiThreadRenderTimer.cs
+++ b/src/Avalonia.Base/Rendering/UiThreadRenderTimer.cs
@@ -32,7 +32,7 @@ namespace Avalonia.Rendering
                     return false;
                 tick(st.Elapsed);
                 return !cancelled;
-            }, TimeSpan.FromSeconds(1.0 / FramesPerSecond), DispatcherPriority.Render);
+            }, TimeSpan.FromSeconds(1.0 / FramesPerSecond), DispatcherPriority.UiThreadRender);
             return Disposable.Create(() => cancelled = true);
         }
     }
diff --git a/src/Avalonia.Base/Rotate3DTransform.cs b/src/Avalonia.Base/Rotate3DTransform.cs
index 2de33889c8..95f5d17740 100644
--- a/src/Avalonia.Base/Rotate3DTransform.cs
+++ b/src/Avalonia.Base/Rotate3DTransform.cs
@@ -7,7 +7,7 @@ namespace Avalonia.Media;
 /// <summary>
 ///  Non-Affine 3D transformation for rotating a visual around a definable axis
 /// </summary>
-public class Rotate3DTransform : Transform
+public sealed class Rotate3DTransform : Transform
 {
     private readonly bool _isInitializing;
     
diff --git a/src/Avalonia.Base/Threading/DispatcherPriority.cs b/src/Avalonia.Base/Threading/DispatcherPriority.cs
index a43dd8e4a2..9fe7056abd 100644
--- a/src/Avalonia.Base/Threading/DispatcherPriority.cs
+++ b/src/Avalonia.Base/Threading/DispatcherPriority.cs
@@ -1,5 +1,6 @@
 using System;
 using System.ComponentModel;
+using Avalonia.Metadata;
 
 namespace Avalonia.Threading
 {
@@ -79,29 +80,39 @@ namespace Avalonia.Threading
         public static readonly DispatcherPriority Loaded = new(Default + 1);
 
         /// <summary>
-        /// The job will be processed with the same priority as render.
+        /// A special priority for platforms with UI render timer or for forced full rasterization requests
         /// </summary>
-        public static readonly DispatcherPriority Render = new(Loaded + 1);
+        [PrivateApi]
+        public static readonly DispatcherPriority UiThreadRender = new(Loaded + 1);
 
         /// <summary>
-        /// The job will be processed with the same priority as composition updates.
+        /// A special priority to synchronize native control host positions, IME, etc
+        /// We should probably have a better API for that, so the priority is internal
         /// </summary>
-        public static readonly DispatcherPriority Composition = new(Render + 1);
-
+        internal static readonly DispatcherPriority AfterRender = new(UiThreadRender + 1);
+        
         /// <summary>
-        /// The job will be processed with before composition updates.
+        /// The job will be processed with the same priority as render.
         /// </summary>
-        public static readonly DispatcherPriority PreComposition = new(Composition + 1);
-
+        public static readonly DispatcherPriority Render = new(AfterRender + 1);
+        
         /// <summary>
-        /// The job will be processed with the same priority as layout.
+        /// A special platform hook for jobs to be executed before the normal render cycle
         /// </summary>
-        public static readonly DispatcherPriority Layout = new(PreComposition + 1);
-
+        [PrivateApi]
+        public static readonly DispatcherPriority BeforeRender = new(Render + 1);
+        
+        /// <summary>
+        /// A special priority for platforms that resize the render target in asynchronous-ish matter,
+        /// should be changed into event grouping in the platform backend render
+        /// </summary>
+        [PrivateApi]
+        public static readonly DispatcherPriority AsyncRenderTargetResize = new(BeforeRender + 1);
+        
         /// <summary>
         /// The job will be processed with the same priority as data binding.
         /// </summary>
-        [Obsolete("WPF compatibility"), EditorBrowsable(EditorBrowsableState.Never)] public static readonly DispatcherPriority DataBind = new(Layout);
+        [Obsolete("WPF compatibility"), EditorBrowsable(EditorBrowsableState.Never)] public static readonly DispatcherPriority DataBind = new(Render);
         
         /// <summary>
         /// The job will be processed with normal priority.
@@ -183,12 +194,16 @@ namespace Avalonia.Threading
                 return nameof(Default);
             if (this == Loaded)
                 return nameof(Loaded);
+            if (this == UiThreadRender)
+                return nameof(UiThreadRender);
+            if (this == AfterRender)
+                return nameof(AfterRender);
             if (this == Render)
                 return nameof(Render);
-            if (this == Composition)
-                return nameof(Composition);
-            if (this == PreComposition)
-                return nameof(PreComposition);
+            if (this == BeforeRender)
+                return nameof(BeforeRender);
+            if (this == AsyncRenderTargetResize)
+                return nameof(AsyncRenderTargetResize);
             if (this == DataBind)
                 return nameof(DataBind);
             if (this == Normal)
diff --git a/src/Avalonia.Base/VisualTree/VisualExtensions.cs b/src/Avalonia.Base/VisualTree/VisualExtensions.cs
index cc372f7c39..b3cdd70fa0 100644
--- a/src/Avalonia.Base/VisualTree/VisualExtensions.cs
+++ b/src/Avalonia.Base/VisualTree/VisualExtensions.cs
@@ -305,7 +305,7 @@ namespace Avalonia.VisualTree
 
             if (rootPoint.HasValue)
             {
-                return root.Renderer.HitTestFirst(rootPoint.Value, visual, filter);
+                return root.HitTester.HitTestFirst(rootPoint.Value, visual, filter);
             }
 
             return null;
@@ -354,7 +354,7 @@ namespace Avalonia.VisualTree
 
             if (rootPoint.HasValue)
             {
-                return root.Renderer.HitTest(rootPoint.Value, visual, filter);
+                return root.HitTester.HitTest(rootPoint.Value, visual, filter);
             }
 
             return Enumerable.Empty<Visual>();
diff --git a/src/Avalonia.Controls/Application.cs b/src/Avalonia.Controls/Application.cs
index e907fd5988..f266aebcb4 100644
--- a/src/Avalonia.Controls/Application.cs
+++ b/src/Avalonia.Controls/Application.cs
@@ -8,6 +8,7 @@ using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.Input.Platform;
 using Avalonia.Input.Raw;
+using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Rendering;
 using Avalonia.Styling;
@@ -259,10 +260,8 @@ namespace Avalonia
                 AvaloniaLocator.CurrentMutable
                     .Bind<IPlatformDragSource>().ToTransient<InProcessDragSource>();
 
-            var clock = new RenderLoopClock();
-            AvaloniaLocator.CurrentMutable
-                .Bind<IGlobalClock>().ToConstant(clock)
-                .GetService<IRenderLoop>()?.Add(clock);
+            AvaloniaLocator.CurrentMutable.Bind<IGlobalClock>()
+                .ToConstant(MediaContext.Instance.Clock);
         }
 
         public virtual void OnFrameworkInitializationCompleted()
diff --git a/src/Avalonia.Controls/Avalonia.Controls.csproj b/src/Avalonia.Controls/Avalonia.Controls.csproj
index 3f1753a4d3..304454777f 100644
--- a/src/Avalonia.Controls/Avalonia.Controls.csproj
+++ b/src/Avalonia.Controls/Avalonia.Controls.csproj
@@ -13,6 +13,8 @@
 
   <ItemGroup Label="InternalsVisibleTo">
     <InternalsVisibleTo Include="Avalonia.Controls.ItemsRepeater, PublicKey=$(AvaloniaPublicKey)" />
+    <InternalsVisibleTo Include="Avalonia.UnitTests, PublicKey=$(AvaloniaPublicKey)" />
+    <InternalsVisibleTo Include="Avalonia.Base.UnitTests, PublicKey=$(AvaloniaPublicKey)" />
     <InternalsVisibleTo Include="Avalonia.Controls.UnitTests, PublicKey=$(AvaloniaPublicKey)" />
     <InternalsVisibleTo Include="Avalonia.Markup.UnitTests, PublicKey=$(AvaloniaPublicKey)" />
     <InternalsVisibleTo Include="Avalonia.DesignerSupport, PublicKey=$(AvaloniaPublicKey)" />
diff --git a/src/Avalonia.Controls/Embedding/EmbeddableControlRoot.cs b/src/Avalonia.Controls/Embedding/EmbeddableControlRoot.cs
index 7a0ab36050..880bbb7340 100644
--- a/src/Avalonia.Controls/Embedding/EmbeddableControlRoot.cs
+++ b/src/Avalonia.Controls/Embedding/EmbeddableControlRoot.cs
@@ -26,6 +26,10 @@ namespace Avalonia.Controls.Embedding
             LayoutManager.ExecuteInitialLayoutPass();
         }
 
+        public new void StartRendering() => base.StartRendering();
+
+        public new void StopRendering() => base.StopRendering();
+        
         private void EnsureInitialized()
         {
             if (!this.IsInitialized)
diff --git a/src/Avalonia.Controls/Embedding/Offscreen/OffscreenTopLevelImpl.cs b/src/Avalonia.Controls/Embedding/Offscreen/OffscreenTopLevelImpl.cs
index 387357dddd..443cd406c9 100644
--- a/src/Avalonia.Controls/Embedding/Offscreen/OffscreenTopLevelImpl.cs
+++ b/src/Avalonia.Controls/Embedding/Offscreen/OffscreenTopLevelImpl.cs
@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using Avalonia.Input;
 using Avalonia.Input.Raw;
+using Avalonia.Media;
 using Avalonia.Metadata;
 using Avalonia.Platform;
 using Avalonia.Rendering;
@@ -34,10 +35,13 @@ namespace Avalonia.Controls.Embedding.Offscreen
             public void TriggerTick() => Tick?.Invoke(St.Elapsed);
         }
 
+        public Compositor Compositor { get; }
 
-        public IRenderer CreateRenderer(IRenderRoot root) =>
-            new CompositingRenderer(root, new Compositor(new RenderLoop(_manualRenderTimer, Dispatcher.UIThread), null),
-                () => Surfaces);
+        public OffscreenTopLevelImplBase()
+        {
+            Compositor = new Compositor(new RenderLoop(_manualRenderTimer), null, false,
+                MediaContext.Instance, false);
+        }
 
         public abstract IEnumerable<object> Surfaces { get; }
 
diff --git a/src/Avalonia.Controls/NativeControlHost.cs b/src/Avalonia.Controls/NativeControlHost.cs
index aa3d6db9e0..67e4c5cf48 100644
--- a/src/Avalonia.Controls/NativeControlHost.cs
+++ b/src/Avalonia.Controls/NativeControlHost.cs
@@ -129,7 +129,7 @@ namespace Avalonia.Controls
             if(_queuedForMoveResize)
                 return;
             _queuedForMoveResize = true;
-            Dispatcher.UIThread.Post(UpdateHost, DispatcherPriority.Render);
+            Dispatcher.UIThread.Post(UpdateHost, DispatcherPriority.AfterRender);
         }
 
         public bool TryUpdateNativeControlPosition()
diff --git a/src/Avalonia.Controls/Platform/ITopLevelImpl.cs b/src/Avalonia.Controls/Platform/ITopLevelImpl.cs
index bb6b2304af..7468f41d14 100644
--- a/src/Avalonia.Controls/Platform/ITopLevelImpl.cs
+++ b/src/Avalonia.Controls/Platform/ITopLevelImpl.cs
@@ -6,6 +6,7 @@ using Avalonia.Input.Raw;
 using Avalonia.Layout;
 using Avalonia.Metadata;
 using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
 
 namespace Avalonia.Platform
 {
@@ -72,10 +73,9 @@ namespace Avalonia.Platform
         Action<WindowTransparencyLevel>? TransparencyLevelChanged { get; set; }
 
         /// <summary>
-        /// Creates a new renderer for the toplevel.
+        /// Gets the compositor that's compatible with the toplevel
         /// </summary>
-        /// <param name="root">The toplevel.</param>
-        IRenderer CreateRenderer(IRenderRoot root);
+        Compositor Compositor { get; }
 
         /// <summary>
         /// Sets the <see cref="IInputRoot"/> for the toplevel.
diff --git a/src/Avalonia.Controls/Presenters/TextPresenter.cs b/src/Avalonia.Controls/Presenters/TextPresenter.cs
index 6fb05463c0..c5b4834ded 100644
--- a/src/Avalonia.Controls/Presenters/TextPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/TextPresenter.cs
@@ -478,7 +478,7 @@ namespace Avalonia.Controls.Presenters
                     {
                         this.BringIntoView(_caretBounds);
                     },
-                    DispatcherPriority.Render);
+                    DispatcherPriority.AfterRender);
             }
         }
 
diff --git a/src/Avalonia.Controls/Primitives/OverlayPopupHost.cs b/src/Avalonia.Controls/Primitives/OverlayPopupHost.cs
index d02d20ea91..2236d87dd1 100644
--- a/src/Avalonia.Controls/Primitives/OverlayPopupHost.cs
+++ b/src/Avalonia.Controls/Primitives/OverlayPopupHost.cs
@@ -124,7 +124,7 @@ namespace Avalonia.Controls.Primitives
             {
                 OverlayLayer.SetLeft(this, _lastRequestedPosition.X);
                 OverlayLayer.SetTop(this, _lastRequestedPosition.Y);
-            }, DispatcherPriority.Layout);
+            }, DispatcherPriority.Render);
         }
 
         double IManagedPopupPositionerPopup.Scaling => 1;
diff --git a/src/Avalonia.Controls/Remote/Server/RemoteServerTopLevelImpl.cs b/src/Avalonia.Controls/Remote/Server/RemoteServerTopLevelImpl.cs
index 58b0ed169c..8e4123a790 100644
--- a/src/Avalonia.Controls/Remote/Server/RemoteServerTopLevelImpl.cs
+++ b/src/Avalonia.Controls/Remote/Server/RemoteServerTopLevelImpl.cs
@@ -41,13 +41,7 @@ namespace Avalonia.Controls.Remote.Server
 
             KeyboardDevice = AvaloniaLocator.Current.GetRequiredService<IKeyboardDevice>();
             QueueNextRender();
-        }
-
-        IRenderer ITopLevelImpl.CreateRenderer(IRenderRoot root)
-        {
-            var r = (IRendererWithCompositor)base.CreateRenderer(root);
-            r.Compositor.AfterCommit += QueueNextRender;
-            return r;
+            Compositor.AfterCommit += QueueNextRender;
         }
 
         private static RawPointerEventType GetAvaloniaEventType(ProtocolMouseButton button, bool pressed)
diff --git a/src/Avalonia.Controls/TopLevel.cs b/src/Avalonia.Controls/TopLevel.cs
index 98c96e4974..b51222a2fe 100644
--- a/src/Avalonia.Controls/TopLevel.cs
+++ b/src/Avalonia.Controls/TopLevel.cs
@@ -22,6 +22,7 @@ using Avalonia.Utilities;
 using Avalonia.Input.Platform;
 using System.Linq;
 using System.Threading.Tasks;
+using Avalonia.Rendering.Composition;
 
 namespace Avalonia.Controls
 {
@@ -182,7 +183,7 @@ namespace Avalonia.Controls
             _globalStyles = TryGetService<IGlobalStyles>(dependencyResolver);
             _applicationThemeHost = TryGetService<IThemeVariantHost>(dependencyResolver);
 
-            Renderer = impl.CreateRenderer(this);
+            Renderer = new CompositingRenderer(this, impl.Compositor, () => impl.Surfaces);
             Renderer.SceneInvalidated += SceneInvalidated;
 
             impl.SetInputRoot(this);
@@ -352,7 +353,7 @@ namespace Avalonia.Controls
             remove { RemoveHandler(BackRequestedEvent, value); }
         }
 
-        public ILayoutManager LayoutManager
+        internal ILayoutManager LayoutManager
         {
             get
             {
@@ -371,6 +372,17 @@ namespace Avalonia.Controls
             }
         }
 
+        ILayoutManager ILayoutRoot.LayoutManager => LayoutManager;
+
+        /// <summary>
+        /// Executes a layout pass.
+        /// </summary>
+        /// <remarks>
+        /// You should not usually need to call this method explictly, the layout manager will
+        /// schedule layout passes itself.
+        /// </remarks>
+        public void UpdateLayout() => LayoutManager?.ExecuteLayoutPass();
+
         /// <summary>
         /// Gets the platform-specific window implementation.
         /// </summary>
@@ -388,7 +400,22 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets the renderer for the window.
         /// </summary>
-        public IRenderer Renderer { get; }
+        internal CompositingRenderer Renderer { get; }
+
+        internal IHitTester HitTester => HitTesterOverride ?? Renderer;
+
+        // This property setter is here purely for lazy unit tests
+        // that don't want to set up a proper hit-testable visual tree
+        // and should be removed after fixing those tests
+        internal IHitTester? HitTesterOverride;
+
+        IRenderer IRenderRoot.Renderer => Renderer;
+        IHitTester IRenderRoot.HitTester => HitTester;
+
+        /// <summary>
+        /// Gets a value indicating whether the renderer should draw specific diagnostics.
+        /// </summary>
+        public RendererDiagnostics RendererDiagnostics => Renderer.Diagnostics;
 
         internal PixelPoint? LastPointerPosition => _pointerOverPreProcessor?.LastPosition;
         
@@ -543,6 +570,10 @@ namespace Avalonia.Controls
             Renderer.Paint(rect);
         }
 
+        protected void StartRendering() => MediaContext.Instance.AddTopLevel(this, LayoutManager, Renderer);
+
+        protected void StopRendering() => MediaContext.Instance.RemoveTopLevel(this);
+
         /// <summary>
         /// Handles a closed notification from <see cref="ITopLevelImpl.Closed"/>.
         /// </summary>
diff --git a/src/Avalonia.Controls/Window.cs b/src/Avalonia.Controls/Window.cs
index e64341b735..42052b8d69 100644
--- a/src/Avalonia.Controls/Window.cs
+++ b/src/Avalonia.Controls/Window.cs
@@ -541,11 +541,11 @@ namespace Avalonia.Controls
 
             if (state == WindowState.Minimized)
             {
-                Renderer.Stop();
+                StopRendering();
             }
             else
             {
-                Renderer.Start();
+                StartRendering();
             }
         }
 
@@ -568,7 +568,7 @@ namespace Avalonia.Controls
                     return;
                 }
 
-                Renderer.Stop();
+                StopRendering();
 
                 if (Owner is Window owner)
                 {
@@ -716,7 +716,7 @@ namespace Avalonia.Controls
                 SetWindowStartupLocation(owner);
 
                 PlatformImpl?.Show(ShowActivated, false);
-                Renderer.Start();
+                StartRendering();
                 OnOpened(EventArgs.Empty);
             }
         }
@@ -793,7 +793,7 @@ namespace Avalonia.Controls
 
                 PlatformImpl?.Show(ShowActivated, true);
 
-                Renderer.Start();
+                StartRendering();
 
                 Observable.FromEventPattern(
                         x => Closed += x,
diff --git a/src/Avalonia.Controls/WindowBase.cs b/src/Avalonia.Controls/WindowBase.cs
index d219734fe0..1cc235ce99 100644
--- a/src/Avalonia.Controls/WindowBase.cs
+++ b/src/Avalonia.Controls/WindowBase.cs
@@ -149,7 +149,7 @@ namespace Avalonia.Controls
         {
             using (FreezeVisibilityChangeHandling())
             {
-                Renderer.Stop();
+                StopRendering();
                 PlatformImpl?.Hide();
                 IsVisible = false;
             }
@@ -173,7 +173,7 @@ namespace Avalonia.Controls
                 }
 
                 PlatformImpl?.Show(true, false);
-                Renderer.Start();
+                StartRendering();
                 OnOpened(EventArgs.Empty);
             }
         }
diff --git a/src/Avalonia.DesignerSupport/Remote/PreviewerWindowingPlatform.cs b/src/Avalonia.DesignerSupport/Remote/PreviewerWindowingPlatform.cs
index ab0a668607..d2787e73ae 100644
--- a/src/Avalonia.DesignerSupport/Remote/PreviewerWindowingPlatform.cs
+++ b/src/Avalonia.DesignerSupport/Remote/PreviewerWindowingPlatform.cs
@@ -52,7 +52,6 @@ namespace Avalonia.DesignerSupport.Remote
                 .Bind<IKeyboardDevice>().ToConstant(Keyboard)
                 .Bind<IPlatformSettings>().ToSingleton<DefaultPlatformSettings>()
                 .Bind<IDispatcherImpl>().ToConstant(new ManagedDispatcherImpl(null))
-                .Bind<IRenderLoop>().ToConstant(new RenderLoop())
                 .Bind<IRenderTimer>().ToConstant(new DefaultRenderTimer(60))
                 .Bind<IWindowingPlatform>().ToConstant(instance)
                 .Bind<IPlatformIconLoader>().ToSingleton<IconLoaderStub>()
diff --git a/src/Avalonia.DesignerSupport/Remote/Stubs.cs b/src/Avalonia.DesignerSupport/Remote/Stubs.cs
index f6f5c185e9..e80690539a 100644
--- a/src/Avalonia.DesignerSupport/Remote/Stubs.cs
+++ b/src/Avalonia.DesignerSupport/Remote/Stubs.cs
@@ -69,10 +69,8 @@ namespace Avalonia.DesignerSupport.Remote
             public bool RunsInBackground => false;
         }
 
-        public IRenderer CreateRenderer(IRenderRoot root) =>
-            new CompositingRenderer(root,
-                new Compositor(new RenderLoop(new DummyRenderTimer(), Dispatcher.UIThread), null), () => Surfaces);
-        
+        public Compositor Compositor { get; } = new(new RenderLoop(new DummyRenderTimer()), null);
+
         public void Dispose()
         {
         }
diff --git a/src/Avalonia.Native/AvaloniaNativePlatform.cs b/src/Avalonia.Native/AvaloniaNativePlatform.cs
index e6a103f6b9..c471cf91d2 100644
--- a/src/Avalonia.Native/AvaloniaNativePlatform.cs
+++ b/src/Avalonia.Native/AvaloniaNativePlatform.cs
@@ -113,10 +113,7 @@ namespace Avalonia.Native
                 .Bind<IPlatformDragSource>().ToConstant(new AvaloniaNativeDragSource(_factory))
                 .Bind<IPlatformLifetimeEventsImpl>().ToConstant(applicationPlatform)
                 .Bind<INativeApplicationCommands>().ToConstant(new MacOSNativeMenuCommands(_factory.CreateApplicationCommands()));
-
-            var renderLoop = new RenderLoop();
-            AvaloniaLocator.CurrentMutable.Bind<IRenderLoop>().ToConstant(renderLoop);
-
+            
             var hotkeys = AvaloniaLocator.Current.GetService<PlatformHotkeyConfiguration>();
             if (hotkeys is not null)
             {
@@ -141,7 +138,7 @@ namespace Avalonia.Native
                 }
             }
             
-            Compositor = new Compositor(renderLoop, _platformGl);
+            Compositor = new Compositor(_platformGl, true);
         }
 
         public ITrayIconImpl CreateTrayIcon()
diff --git a/src/Avalonia.Native/WindowImplBase.cs b/src/Avalonia.Native/WindowImplBase.cs
index b802b1db71..e71fddea3f 100644
--- a/src/Avalonia.Native/WindowImplBase.cs
+++ b/src/Avalonia.Native/WindowImplBase.cs
@@ -200,7 +200,7 @@ namespace Avalonia.Native
 
             void IAvnWindowBaseEvents.Paint()
             {
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Render);
+                Dispatcher.UIThread.RunJobs(DispatcherPriority.UiThreadRender);
                 var s = _parent.ClientSize;
                 _parent.Paint?.Invoke(new Rect(0, 0, s.Width, s.Height));
             }
@@ -243,7 +243,7 @@ namespace Avalonia.Native
 
             void IAvnWindowBaseEvents.RunRenderPriorityJobs()
             {
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Render);
+                Dispatcher.UIThread.RunJobs(DispatcherPriority.UiThreadRender);
             }
             
             void IAvnWindowBaseEvents.LostFocus()
@@ -365,13 +365,7 @@ namespace Avalonia.Native
             _native?.Resize(clientSize.Width, clientSize.Height, (AvnPlatformResizeReason)reason);
         }
 
-        public IRenderer CreateRenderer(IRenderRoot root)
-        {
-            return new CompositingRenderer(root, AvaloniaNativePlatform.Compositor, () => Surfaces)
-            {
-                RenderOnlyOnRenderThread = false
-            };
-        }
+        public Compositor Compositor => AvaloniaNativePlatform.Compositor;
 
         public virtual void Dispose()
         {
diff --git a/src/Avalonia.X11/X11Platform.cs b/src/Avalonia.X11/X11Platform.cs
index fc8b6f2ed6..a880e4ba1a 100644
--- a/src/Avalonia.X11/X11Platform.cs
+++ b/src/Avalonia.X11/X11Platform.cs
@@ -75,7 +75,6 @@ namespace Avalonia.X11
                 .Bind<IWindowingPlatform>().ToConstant(this)
                 .Bind<IDispatcherImpl>().ToConstant(new X11PlatformThreading(this))
                 .Bind<IRenderTimer>().ToConstant(new SleepLoopRenderTimer(60))
-                .Bind<IRenderLoop>().ToConstant(new RenderLoop())
                 .Bind<PlatformHotkeyConfiguration>().ToConstant(new PlatformHotkeyConfiguration(KeyModifiers.Control))
                 .Bind<IKeyboardDevice>().ToFunc(() => KeyboardDevice)
                 .Bind<ICursorFactory>().ToConstant(new X11CursorFactory(Display))
@@ -104,7 +103,7 @@ namespace Avalonia.X11
 
             var gl = AvaloniaLocator.Current.GetService<IPlatformGraphics>();
 
-            Compositor = new Compositor(AvaloniaLocator.Current.GetRequiredService<IRenderLoop>(), gl);
+            Compositor = new Compositor(gl);
         }
 
         public IntPtr DeferredDisplay { get; set; }
diff --git a/src/Avalonia.X11/X11Window.cs b/src/Avalonia.X11/X11Window.cs
index 0a535d2f57..eee69b7485 100644
--- a/src/Avalonia.X11/X11Window.cs
+++ b/src/Avalonia.X11/X11Window.cs
@@ -382,9 +382,8 @@ namespace Avalonia.X11
         public Action<PixelPoint>? PositionChanged { get; set; }
         public Action? LostFocus { get; set; }
 
-        public IRenderer CreateRenderer(IRenderRoot root) =>
-            new CompositingRenderer(root, _platform.Compositor, () => Surfaces);
-
+        public Compositor Compositor => _platform.Compositor;
+        
         private void OnEvent(ref XEvent ev)
         {
             if (_inputRoot is null)
@@ -511,7 +510,7 @@ namespace Avalonia.X11
                         if (changedSize && !updatedSizeViaScaling && !_popup)
                             Resized?.Invoke(ClientSize, WindowResizeReason.Unspecified);
 
-                    }, DispatcherPriority.Layout);
+                    }, DispatcherPriority.AsyncRenderTargetResize);
                 if (_useRenderWindow)
                     XConfigureResizeWindow(_x11.Display, _renderHandle, ev.ConfigureEvent.width,
                         ev.ConfigureEvent.height);
@@ -796,7 +795,7 @@ namespace Avalonia.X11
                 {
                     _triggeredExpose = false;
                     DoPaint();
-                }, DispatcherPriority.Render);
+                }, DispatcherPriority.UiThreadRender);
             }
         }
 
diff --git a/src/Browser/Avalonia.Browser/BrowserTopLevelImpl.cs b/src/Browser/Avalonia.Browser/BrowserTopLevelImpl.cs
index 8456dc92d0..638c732d5b 100644
--- a/src/Browser/Avalonia.Browser/BrowserTopLevelImpl.cs
+++ b/src/Browser/Avalonia.Browser/BrowserTopLevelImpl.cs
@@ -187,12 +187,9 @@ namespace Avalonia.Browser
 
         }
 
-        public IRenderer CreateRenderer(IRenderRoot root)
-        {
-            var loop = AvaloniaLocator.Current.GetRequiredService<IRenderLoop>();
-            return new CompositingRenderer(root,
-                new Compositor(loop, AvaloniaLocator.Current.GetRequiredService<IPlatformGraphics>()), () => Surfaces);
-        }
+        public Compositor Compositor { get; } = new(
+            AvaloniaLocator.Current.GetRequiredService<IRenderLoop>(),
+            AvaloniaLocator.Current.GetRequiredService<IPlatformGraphics>());
 
         public void Invalidate(Rect rect)
         {
diff --git a/src/Browser/Avalonia.Browser/WindowingPlatform.cs b/src/Browser/Avalonia.Browser/WindowingPlatform.cs
index a33738079c..3ad2620206 100644
--- a/src/Browser/Avalonia.Browser/WindowingPlatform.cs
+++ b/src/Browser/Avalonia.Browser/WindowingPlatform.cs
@@ -41,7 +41,6 @@ namespace Avalonia.Browser
                 .Bind<IKeyboardDevice>().ToConstant(s_keyboard)
                 .Bind<IPlatformSettings>().ToSingleton<BrowserPlatformSettings>()
                 .Bind<IPlatformThreadingInterface>().ToConstant(instance)
-                .Bind<IRenderLoop>().ToConstant(new RenderLoop())
                 .Bind<IRenderTimer>().ToConstant(ManualTriggerRenderTimer.Instance)
                 .Bind<IWindowingPlatform>().ToConstant(instance)
                 .Bind<IPlatformGraphics>().ToConstant(new BrowserSkiaGraphics())
diff --git a/src/Headless/Avalonia.Headless/AvaloniaHeadlessPlatform.cs b/src/Headless/Avalonia.Headless/AvaloniaHeadlessPlatform.cs
index 8202dab874..411cdd5a95 100644
--- a/src/Headless/Avalonia.Headless/AvaloniaHeadlessPlatform.cs
+++ b/src/Headless/Avalonia.Headless/AvaloniaHeadlessPlatform.cs
@@ -24,7 +24,7 @@ namespace Avalonia.Headless
                 var st = Stopwatch.StartNew();
                 _forceTick = () => tick(st.Elapsed);
 
-                var timer = new DispatcherTimer(DispatcherPriority.Render)
+                var timer = new DispatcherTimer(DispatcherPriority.UiThreadRender)
                 {
                     Interval = TimeSpan.FromSeconds(1.0 / _framesPerSecond),
                     Tag = "HeadlessRenderTimer"
@@ -69,11 +69,10 @@ namespace Avalonia.Headless
                 .Bind<IPlatformSettings>().ToSingleton<DefaultPlatformSettings>()
                 .Bind<IPlatformIconLoader>().ToSingleton<HeadlessIconLoaderStub>()
                 .Bind<IKeyboardDevice>().ToConstant(new KeyboardDevice())
-                .Bind<IRenderLoop>().ToConstant(new RenderLoop())
                 .Bind<IRenderTimer>().ToConstant(new RenderTimer(60))
                 .Bind<IWindowingPlatform>().ToConstant(new HeadlessWindowingPlatform())
                 .Bind<PlatformHotkeyConfiguration>().ToSingleton<PlatformHotkeyConfiguration>();
-            Compositor = new Compositor(AvaloniaLocator.Current.GetRequiredService<IRenderLoop>(), null);
+            Compositor = new Compositor( null);
         }
 
         /// <summary>
diff --git a/src/Headless/Avalonia.Headless/HeadlessWindowImpl.cs b/src/Headless/Avalonia.Headless/HeadlessWindowImpl.cs
index 93f92d46f8..31c38c5171 100644
--- a/src/Headless/Avalonia.Headless/HeadlessWindowImpl.cs
+++ b/src/Headless/Avalonia.Headless/HeadlessWindowImpl.cs
@@ -53,8 +53,7 @@ namespace Avalonia.Headless
         public Action<Size, WindowResizeReason>? Resized { get; set; }
         public Action<double>? ScalingChanged { get; set; }
 
-        public IRenderer CreateRenderer(IRenderRoot root) =>
-            new CompositingRenderer(root, AvaloniaHeadlessPlatform.Compositor!, () => Surfaces);
+        public Compositor Compositor => AvaloniaHeadlessPlatform.Compositor!;
 
         public void Invalidate(Rect rect)
         {
diff --git a/src/Linux/Avalonia.LinuxFramebuffer/FramebufferToplevelImpl.cs b/src/Linux/Avalonia.LinuxFramebuffer/FramebufferToplevelImpl.cs
index ccc8cab8ae..a56368fca9 100644
--- a/src/Linux/Avalonia.LinuxFramebuffer/FramebufferToplevelImpl.cs
+++ b/src/Linux/Avalonia.LinuxFramebuffer/FramebufferToplevelImpl.cs
@@ -32,10 +32,7 @@ using Avalonia.Rendering.Composition;
                 Dispatcher.UIThread.Post(() => _inputQueue.HandleEvent(e), DispatcherPriority.Send ));
         }
 
-        public IRenderer CreateRenderer(IRenderRoot root)
-        {
-            return new CompositingRenderer(root, LinuxFramebufferPlatform.Compositor, () => Surfaces);
-        }
+        public Compositor Compositor => LinuxFramebufferPlatform.Compositor;
 
         public void Dispose()
         {
diff --git a/src/Linux/Avalonia.LinuxFramebuffer/LinuxFramebufferPlatform.cs b/src/Linux/Avalonia.LinuxFramebuffer/LinuxFramebufferPlatform.cs
index c352b5f9bf..438e94b42e 100644
--- a/src/Linux/Avalonia.LinuxFramebuffer/LinuxFramebufferPlatform.cs
+++ b/src/Linux/Avalonia.LinuxFramebuffer/LinuxFramebufferPlatform.cs
@@ -45,15 +45,12 @@ namespace Avalonia.LinuxFramebuffer
             AvaloniaLocator.CurrentMutable
                 .Bind<IDispatcherImpl>().ToConstant(new ManagedDispatcherImpl(new ManualRawEventGrouperDispatchQueueDispatcherInputProvider(EventGrouperDispatchQueue)))
                 .Bind<IRenderTimer>().ToConstant(new DefaultRenderTimer(opts.Fps))
-                .Bind<IRenderLoop>().ToConstant(new RenderLoop())
                 .Bind<ICursorFactory>().ToTransient<CursorFactoryStub>()
                 .Bind<IKeyboardDevice>().ToConstant(new KeyboardDevice())
                 .Bind<IPlatformSettings>().ToSingleton<DefaultPlatformSettings>()
                 .Bind<PlatformHotkeyConfiguration>().ToSingleton<PlatformHotkeyConfiguration>();
             
-            Compositor = new Compositor(
-                AvaloniaLocator.Current.GetRequiredService<IRenderLoop>(),
-                AvaloniaLocator.Current.GetService<IPlatformGraphics>());
+            Compositor = new Compositor(AvaloniaLocator.Current.GetService<IPlatformGraphics>());
         }
 
 
@@ -69,7 +66,7 @@ namespace Avalonia.LinuxFramebuffer
     {
         private readonly IOutputBackend _fb;
         private readonly IInputBackend? _inputBackend;
-        private TopLevel? _topLevel;
+        private EmbeddableControlRoot? _topLevel;
         private readonly CancellationTokenSource _cts = new CancellationTokenSource();
         public CancellationToken Token => _cts.Token;
 
@@ -102,8 +99,9 @@ namespace Avalonia.LinuxFramebuffer
 
                     var tl = new EmbeddableControlRoot(new FramebufferToplevelImpl(_fb, inputBackend));
                     tl.Prepare();
+                    tl.StartRendering();
                     _topLevel = tl;
-                    _topLevel.Renderer.Start();
+                    
 
                     if (_topLevel is IFocusScope scope)
                     {
diff --git a/src/Windows/Avalonia.Win32/Win32Platform.cs b/src/Windows/Avalonia.Win32/Win32Platform.cs
index 7ce599c6bf..e9019803be 100644
--- a/src/Windows/Avalonia.Win32/Win32Platform.cs
+++ b/src/Windows/Avalonia.Win32/Win32Platform.cs
@@ -159,7 +159,6 @@ namespace Avalonia.Win32
                 .Bind<IKeyboardDevice>().ToConstant(WindowsKeyboardDevice.Instance)
                 .Bind<IPlatformSettings>().ToSingleton<Win32PlatformSettings>()
                 .Bind<IDispatcherImpl>().ToConstant(s_instance._dispatcher)
-                .Bind<IRenderLoop>().ToConstant(new RenderLoop())
                 .Bind<IRenderTimer>().ToConstant(renderTimer)
                 .Bind<IWindowingPlatform>().ToConstant(s_instance)
                 .Bind<PlatformHotkeyConfiguration>().ToConstant(new PlatformHotkeyConfiguration(KeyModifiers.Control)
@@ -181,7 +180,7 @@ namespace Avalonia.Win32
             if (OleContext.Current != null)
                 AvaloniaLocator.CurrentMutable.Bind<IPlatformDragSource>().ToSingleton<DragSource>();
             
-            s_compositor = new Compositor(AvaloniaLocator.Current.GetRequiredService<IRenderLoop>(), platformGraphics);
+            s_compositor = new Compositor( platformGraphics);
         }
         
         public event EventHandler<ShutdownRequestedEventArgs>? ShutdownRequested;
diff --git a/src/Windows/Avalonia.Win32/WindowImpl.CustomCaptionProc.cs b/src/Windows/Avalonia.Win32/WindowImpl.CustomCaptionProc.cs
index 4a4565a443..7c5aff8b75 100644
--- a/src/Windows/Avalonia.Win32/WindowImpl.CustomCaptionProc.cs
+++ b/src/Windows/Avalonia.Win32/WindowImpl.CustomCaptionProc.cs
@@ -1,6 +1,7 @@
 using System;
 using Avalonia.Controls;
 using Avalonia.Input;
+using Avalonia.VisualTree;
 using static Avalonia.Win32.Interop.UnmanagedMethods;
 
 namespace Avalonia.Win32
@@ -105,7 +106,7 @@ namespace Avalonia.Win32
 
                             if (_owner is Window window)
                             {
-                                var visual = window.Renderer.HitTestFirst(position, window, x =>
+                                var visual = window.GetVisualAt(position, x =>
                                 {
                                     if (x is IInputElement ie && (!ie.IsHitTestVisible || !ie.IsEffectivelyVisible))
                                     {
diff --git a/src/Windows/Avalonia.Win32/WindowImpl.cs b/src/Windows/Avalonia.Win32/WindowImpl.cs
index 9217f42952..6ca59ca38c 100644
--- a/src/Windows/Avalonia.Win32/WindowImpl.cs
+++ b/src/Windows/Avalonia.Win32/WindowImpl.cs
@@ -585,8 +585,7 @@ namespace Avalonia.Win32
             _maxSize = maxSize;
         }
 
-        public IRenderer CreateRenderer(IRenderRoot root) =>
-            new CompositingRenderer(root, Win32Platform.Compositor, () => Surfaces);
+        public Compositor Compositor => Win32Platform.Compositor;
 
         public void Resize(Size value, WindowResizeReason reason)
         {
diff --git a/src/iOS/Avalonia.iOS/AvaloniaView.cs b/src/iOS/Avalonia.iOS/AvaloniaView.cs
index 6ca0cf7ace..86aac0e456 100644
--- a/src/iOS/Avalonia.iOS/AvaloniaView.cs
+++ b/src/iOS/Avalonia.iOS/AvaloniaView.cs
@@ -110,9 +110,7 @@ namespace Avalonia.iOS
                 // No-op
             }
 
-            public IRenderer CreateRenderer(IRenderRoot root) =>
-                new CompositingRenderer(root, Platform.Compositor, () => Surfaces);
-
+            public Compositor Compositor => Platform.Compositor;
 
             public void Invalidate(Rect rect)
             {
diff --git a/src/iOS/Avalonia.iOS/Platform.cs b/src/iOS/Avalonia.iOS/Platform.cs
index cf5c89cf5f..918c0caaa2 100644
--- a/src/iOS/Avalonia.iOS/Platform.cs
+++ b/src/iOS/Avalonia.iOS/Platform.cs
@@ -43,7 +43,6 @@ namespace Avalonia.iOS
                 .Bind<IPlatformSettings>().ToSingleton<PlatformSettings>()
                 .Bind<IPlatformIconLoader>().ToConstant(new PlatformIconLoaderStub())
                 .Bind<PlatformHotkeyConfiguration>().ToSingleton<PlatformHotkeyConfiguration>()
-                .Bind<IRenderLoop>().ToSingleton<RenderLoop>()
                 .Bind<IRenderTimer>().ToConstant(Timer)
                 .Bind<IDispatcherImpl>().ToConstant(DispatcherImpl.Instance)
                 .Bind<IKeyboardDevice>().ToConstant(keyboard);
diff --git a/tests/Avalonia.Base.UnitTests/Composition/BatchStreamTests.cs b/tests/Avalonia.Base.UnitTests/Composition/BatchStreamTests.cs
index a1b55257e6..5118ac7f71 100644
--- a/tests/Avalonia.Base.UnitTests/Composition/BatchStreamTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Composition/BatchStreamTests.cs
@@ -12,8 +12,8 @@ public class BatchStreamTests
     public void BatchStreamCorrectlyWritesAndReadsData()
     {
         var data = new BatchStreamData();
-        var memPool = new BatchStreamMemoryPool(100, _ => { });
-        var objPool = new BatchStreamObjectPool<object>(10, _ => { });
+        var memPool = new BatchStreamMemoryPool(false, 100, _ => { });
+        var objPool = new BatchStreamObjectPool<object>(false, 10, _ => { });
 
         var guids = new List<Guid>();
         var objects = new List<object>();
diff --git a/tests/Avalonia.Base.UnitTests/Composition/CompositionAnimationTests.cs b/tests/Avalonia.Base.UnitTests/Composition/CompositionAnimationTests.cs
index 510d7c2c6d..b1ca75d018 100644
--- a/tests/Avalonia.Base.UnitTests/Composition/CompositionAnimationTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Composition/CompositionAnimationTests.cs
@@ -78,8 +78,9 @@ public class CompositionAnimationTests
     [Theory]
     public void GenericCheck(AnimationData data)
     {
+        using var scope = AvaloniaLocator.EnterScope();
         var compositor =
-            new Compositor(new RenderLoop(new CompositorTestServices.ManualRenderTimer(), new DummyDispatcher()), null);
+            new Compositor(new RenderLoop(new CompositorTestServices.ManualRenderTimer()), null);
         var target = compositor.CreateSolidColorVisual();
         var ani = new ScalarKeyFrameAnimation(null);
         foreach (var frame in data.Frames)
diff --git a/tests/Avalonia.Base.UnitTests/Input/MouseDeviceTests.cs b/tests/Avalonia.Base.UnitTests/Input/MouseDeviceTests.cs
index 642e762c1b..8aabd22b08 100644
--- a/tests/Avalonia.Base.UnitTests/Input/MouseDeviceTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Input/MouseDeviceTests.cs
@@ -3,6 +3,7 @@ using Avalonia.Input;
 using Avalonia.Input.Raw;
 using Avalonia.Media;
 using Avalonia.Platform;
+using Avalonia.Rendering;
 using Avalonia.Threading;
 using Avalonia.UnitTests;
 using Moq;
@@ -29,12 +30,12 @@ namespace Avalonia.Base.UnitTests.Input
                     inputManager: new InputManager(),
                     dispatcherImpl: dispatcherMock.Object));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var device = new MouseDevice();
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
 
             var control = new Control();
-            var root = CreateInputRoot(impl.Object, control);
+            var root = CreateInputRoot(impl.Object, control, renderer.Object);
            
             MouseButton button = default;
 
@@ -64,9 +65,9 @@ namespace Avalonia.Base.UnitTests.Input
         {
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var device = new MouseDevice();
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
 
             Canvas control;
             Panel rootChild;
@@ -76,7 +77,7 @@ namespace Avalonia.Base.UnitTests.Input
                 {
                     (control = new Canvas())
                 }
-            });
+            }, renderer.Object);
 
             // Synthesize event to receive a pointer.
             IPointer result = null;
@@ -102,9 +103,9 @@ namespace Avalonia.Base.UnitTests.Input
         {
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var device = new MouseDevice();
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
 
             Border border;
             var root = CreateInputRoot(impl.Object, new Panel
@@ -117,7 +118,7 @@ namespace Avalonia.Base.UnitTests.Input
                         RenderTransform = new TranslateTransform(10, 0),
                     })
                 }
-            });
+            }, renderer.Object);
            
            
             Point? result = null;
diff --git a/tests/Avalonia.Base.UnitTests/Input/PointerOverTests.cs b/tests/Avalonia.Base.UnitTests/Input/PointerOverTests.cs
index ae6b601896..62c99a553b 100644
--- a/tests/Avalonia.Base.UnitTests/Input/PointerOverTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Input/PointerOverTests.cs
@@ -24,9 +24,9 @@ namespace Avalonia.Base.UnitTests.Input
                 inputManager: new InputManager(),
                 focusManager: new FocusManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var device = CreatePointerDeviceMock().Object;
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
 
             Canvas canvas;
             var root = CreateInputRoot(impl.Object, new Panel
@@ -35,7 +35,7 @@ namespace Avalonia.Base.UnitTests.Input
                 {
                     (canvas = new Canvas())
                 }
-            });
+            }, renderer.Object);
 
             SetHit(renderer, canvas);
             impl.Object.Input!(CreateRawPointerMovedArgs(device, root));
@@ -52,9 +52,9 @@ namespace Avalonia.Base.UnitTests.Input
         {
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var device = CreatePointerDeviceMock().Object;
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
 
             Canvas canvas;
             Border border;
@@ -70,7 +70,7 @@ namespace Avalonia.Base.UnitTests.Input
                         Child = decorator = new Decorator(),
                     })
                 }
-            });
+            }, renderer.Object);
 
             SetHit(renderer, decorator);
             impl.Object.Input!(CreateRawPointerMovedArgs(device, root));
@@ -95,9 +95,9 @@ namespace Avalonia.Base.UnitTests.Input
         {
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var device = CreatePointerDeviceMock(pointerType: PointerType.Touch).Object;
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
 
             Canvas canvas;
 
@@ -107,7 +107,7 @@ namespace Avalonia.Base.UnitTests.Input
                 {
                     (canvas = new Canvas())
                 }
-            });
+            }, renderer.Object);
 
             SetHit(renderer, canvas);
             impl.Object.Input!(CreateRawPointerMovedArgs(device, root));
@@ -121,10 +121,10 @@ namespace Avalonia.Base.UnitTests.Input
         {
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var pointer = new Mock<IPointer>();
             var device = CreatePointerDeviceMock(pointer.Object).Object;
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
 
             Canvas canvas;
             Border border;
@@ -140,7 +140,7 @@ namespace Avalonia.Base.UnitTests.Input
                         Child = decorator = new Decorator(),
                     })
                 }
-            });
+            }, renderer.Object);
 
             SetHit(renderer, canvas);
             pointer.SetupGet(p => p.Captured).Returns(decorator);
@@ -157,9 +157,9 @@ namespace Avalonia.Base.UnitTests.Input
         {
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var device = CreatePointerDeviceMock().Object;
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
 
             Canvas canvas;
             Border border;
@@ -175,7 +175,7 @@ namespace Avalonia.Base.UnitTests.Input
                         Child = decorator = new Decorator(),
                     })
                 }
-            });
+            }, renderer.Object);
 
             SetHit(renderer, canvas);
             impl.Object.Input!(CreateRawPointerMovedArgs(device, root));
@@ -203,9 +203,9 @@ namespace Avalonia.Base.UnitTests.Input
         {
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var deviceMock = CreatePointerDeviceMock();
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
             var result = new List<(object?, string)>();
 
             void HandleEvent(object? sender, PointerEventArgs e)
@@ -227,7 +227,7 @@ namespace Avalonia.Base.UnitTests.Input
                         Child = decorator = new Decorator(),
                     })
                 }
-            });
+            }, renderer.Object);
 
             AddEnteredExitedHandlers(HandleEvent, canvas, decorator);
 
@@ -258,9 +258,9 @@ namespace Avalonia.Base.UnitTests.Input
         {
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var deviceMock = CreatePointerDeviceMock();
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
             var result = new List<(object?, string)>();
 
             void HandleEvent(object? sender, PointerEventArgs e)
@@ -282,7 +282,7 @@ namespace Avalonia.Base.UnitTests.Input
                         Child = decorator = new Decorator(),
                     })
                 }
-            });
+            }, renderer.Object);
 
             SetHit(renderer, canvas);
             impl.Object.Input!(CreateRawPointerMovedArgs(deviceMock.Object, root));
@@ -309,9 +309,9 @@ namespace Avalonia.Base.UnitTests.Input
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
             var expectedPosition = new Point(15, 15);
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var deviceMock = CreatePointerDeviceMock();
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
             var result = new List<(object?, string, Point)>();
 
             void HandleEvent(object? sender, PointerEventArgs e)
@@ -327,7 +327,7 @@ namespace Avalonia.Base.UnitTests.Input
                 {
                     (canvas = new Canvas())
                 }
-            });
+            }, renderer.Object);
 
             AddEnteredExitedHandlers(HandleEvent, root, canvas);
 
@@ -348,14 +348,17 @@ namespace Avalonia.Base.UnitTests.Input
                 result);
         }
 
+        void RaiseSceneInvalidated(TopLevel tl) =>
+            tl.Renderer.TriggerSceneInvalidatedForUnitTests(new Rect(0, 0, 10000, 10000));
+
         [Fact]
         public void Render_Invalidation_Should_Affect_PointerOver()
         {
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var deviceMock = CreatePointerDeviceMock();
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
 
             var invalidateRect = new Rect(0, 0, 15, 15);
             var lastClientPosition = new Point(1, 5);
@@ -374,7 +377,7 @@ namespace Avalonia.Base.UnitTests.Input
                 {
                     (canvas = new Canvas())
                 }
-            });
+            }, renderer.Object);
             AddEnteredExitedHandlers(HandleEvent, root, canvas);
 
             // Let input know about latest device.
@@ -383,12 +386,12 @@ namespace Avalonia.Base.UnitTests.Input
             Assert.True(canvas.IsPointerOver);
 
             SetHit(renderer, canvas);
-            renderer.Raise(r => r.SceneInvalidated += null, new SceneInvalidatedEventArgs((IRenderRoot)root, invalidateRect));
+            RaiseSceneInvalidated(root);
             Assert.True(canvas.IsPointerOver);
 
             // Raise SceneInvalidated again, but now hide element from the hittest.
             SetHit(renderer, null);
-            renderer.Raise(r => r.SceneInvalidated += null, new SceneInvalidatedEventArgs((IRenderRoot)root, invalidateRect));
+            RaiseSceneInvalidated(root);
             Assert.False(canvas.IsPointerOver);
 
             Assert.Equal(
@@ -407,9 +410,9 @@ namespace Avalonia.Base.UnitTests.Input
         {
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var deviceMock = CreatePointerDeviceMock();
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
 
             var invalidateRect = new Rect(0, 0, 15, 15);
 
@@ -422,7 +425,7 @@ namespace Avalonia.Base.UnitTests.Input
                     (canvas1 = new Canvas()),
                     (canvas2 = new Canvas())
                 }
-            });
+            }, renderer.Object);
 
             canvas1.PointerMoved += (s, a) => a.Pointer.Capture(canvas1);
 
@@ -433,7 +436,7 @@ namespace Avalonia.Base.UnitTests.Input
             Assert.False(canvas2.IsPointerOver);
 
             SetHit(renderer, canvas2);
-            renderer.Raise(r => r.SceneInvalidated += null, new SceneInvalidatedEventArgs((IRenderRoot)root, invalidateRect));
+            RaiseSceneInvalidated(root);
             Assert.False(canvas1.IsPointerOver);
             Assert.True(canvas2.IsPointerOver);
         }
@@ -444,9 +447,9 @@ namespace Avalonia.Base.UnitTests.Input
         {
             using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
 
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var deviceMock = CreatePointerDeviceMock();
-            var impl = CreateTopLevelImplMock(renderer.Object);
+            var impl = CreateTopLevelImplMock();
 
             var lastClientPosition = new Point(1, 5);
             var invalidateRect = new Rect(0, 0, 15, 15);
@@ -465,7 +468,7 @@ namespace Avalonia.Base.UnitTests.Input
                 {
                     (canvas = new Canvas())
                 }
-            });
+            }, renderer.Object);
 
             AddEnteredExitedHandlers(HandleEvent, root, canvas);
 
diff --git a/tests/Avalonia.Base.UnitTests/Input/PointerTestsBase.cs b/tests/Avalonia.Base.UnitTests/Input/PointerTestsBase.cs
index 5915343764..b4d20f2496 100644
--- a/tests/Avalonia.Base.UnitTests/Input/PointerTestsBase.cs
+++ b/tests/Avalonia.Base.UnitTests/Input/PointerTestsBase.cs
@@ -7,6 +7,8 @@ using Avalonia.Input;
 using Avalonia.Input.Raw;
 using Avalonia.Platform;
 using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
+using Avalonia.UnitTests;
 using Avalonia.VisualTree;
 using Moq;
 
@@ -14,7 +16,7 @@ namespace Avalonia.Base.UnitTests.Input;
 
 public abstract class PointerTestsBase
 {
-    protected static void SetHit(Mock<IRenderer> renderer, Control? hit)
+    private protected static void SetHit(Mock<IHitTester> renderer, Control? hit)
     {
         renderer.Setup(x => x.HitTest(It.IsAny<Point>(), It.IsAny<Visual>(), It.IsAny<Func<Visual, bool>>()))
             .Returns(hit is null ? Array.Empty<Control>() : new[] { hit });
@@ -29,27 +31,28 @@ public abstract class PointerTestsBase
             .Callback(() => element.RaiseEvent(CreatePointerMovedArgs(root, element)));
     }
 
-    protected static Mock<IWindowImpl> CreateTopLevelImplMock(IRenderer renderer)
+    private protected static Mock<IWindowImpl> CreateTopLevelImplMock()
     {
         var impl = new Mock<IWindowImpl>();
         impl.DefaultValue = DefaultValue.Mock;
         impl.SetupAllProperties();
         impl.SetupGet(r => r.RenderScaling).Returns(1);
         impl.Setup(r => r.TryGetFeature(It.IsAny<Type>())).Returns(null);
-        impl.Setup(r => r.CreateRenderer(It.IsAny<IRenderRoot>())).Returns(renderer);
+        impl.Setup(r => r.Compositor).Returns(RendererMocks.CreateDummyCompositor());
         impl.Setup(r => r.PointToScreen(It.IsAny<Point>())).Returns<Point>(p => new PixelPoint((int)p.X, (int)p.Y));
         impl.Setup(r => r.PointToClient(It.IsAny<PixelPoint>())).Returns<PixelPoint>(p => new Point(p.X, p.Y));
         return impl;
     }
 
-    protected static IInputRoot CreateInputRoot(IWindowImpl impl, Control child)
+    private protected static TopLevel CreateInputRoot(IWindowImpl impl, Control child, IHitTester hitTester)
     {
         var root = new Window(impl)
         {
             Width = 100,
             Height = 100,
             Content = child,
-            Template = new FuncControlTemplate<Window>((w, _) => new ContentPresenter { Content = w.Content })
+            Template = new FuncControlTemplate<Window>((w, _) => new ContentPresenter { Content = w.Content }),
+            HitTesterOverride = hitTester
         };
         root.Show();
         return root;
diff --git a/tests/Avalonia.Base.UnitTests/Layout/LayoutManagerTests.cs b/tests/Avalonia.Base.UnitTests/Layout/LayoutManagerTests.cs
index cadf23c754..dacd468a67 100644
--- a/tests/Avalonia.Base.UnitTests/Layout/LayoutManagerTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Layout/LayoutManagerTests.cs
@@ -3,11 +3,12 @@ using System.Linq;
 using Avalonia.Controls;
 using Avalonia.Layout;
 using Avalonia.Threading;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Base.UnitTests.Layout
 {
-    public class LayoutManagerTests
+    public class LayoutManagerTests : ScopedTestBase
     {
         [Fact]
         public void Measures_And_Arranges_InvalidateMeasured_Control()
@@ -476,7 +477,7 @@ namespace Avalonia.Base.UnitTests.Layout
             root.LayoutManager.InvalidateArrange(control);
             root.LayoutManager.ExecuteInitialLayoutPass();
             
-            Dispatcher.UIThread.RunJobs(DispatcherPriority.Layout);
+            Dispatcher.UIThread.RunJobs(DispatcherPriority.Render);
             
             Assert.Equal(1, layoutCount);
         }
diff --git a/tests/Avalonia.Base.UnitTests/Layout/LayoutableTests_EffectiveViewportChanged.cs b/tests/Avalonia.Base.UnitTests/Layout/LayoutableTests_EffectiveViewportChanged.cs
index 536c766a7d..5a493cb741 100644
--- a/tests/Avalonia.Base.UnitTests/Layout/LayoutableTests_EffectiveViewportChanged.cs
+++ b/tests/Avalonia.Base.UnitTests/Layout/LayoutableTests_EffectiveViewportChanged.cs
@@ -182,6 +182,7 @@ namespace Avalonia.Base.UnitTests.Layout
         [Fact]
         public async Task Scrolled_ScrollViewer_Determines_EffectiveViewport()
         {
+            using var scope = AvaloniaLocator.EnterScope();
             await RunOnUIThread.Execute(async () =>
             {
                 var root = CreateRoot();
@@ -207,6 +208,7 @@ namespace Avalonia.Base.UnitTests.Layout
         [Fact]
         public async Task Moving_Parent_Updates_EffectiveViewport()
         {
+            using var scope = AvaloniaLocator.EnterScope();
             await RunOnUIThread.Execute(async () =>
             {
                 var root = CreateRoot();
@@ -234,6 +236,7 @@ namespace Avalonia.Base.UnitTests.Layout
         [Fact]
         public async Task Translate_Transform_Doesnt_Affect_EffectiveViewport()
         {
+            using var scope = AvaloniaLocator.EnterScope();
             await RunOnUIThread.Execute(async () =>
             {
                 var root = CreateRoot();
@@ -256,6 +259,7 @@ namespace Avalonia.Base.UnitTests.Layout
         [Fact]
         public async Task Translate_Transform_On_Parent_Affects_EffectiveViewport()
         {
+            using var scope = AvaloniaLocator.EnterScope();
             await RunOnUIThread.Execute(async () =>
             {
                 var root = CreateRoot();
@@ -286,6 +290,7 @@ namespace Avalonia.Base.UnitTests.Layout
         [Fact]
         public async Task Rotate_Transform_On_Parent_Affects_EffectiveViewport()
         {
+            using var scope = AvaloniaLocator.EnterScope();
             await RunOnUIThread.Execute(async () =>
             {
                 var root = CreateRoot();
diff --git a/tests/Avalonia.Base.UnitTests/Rendering/RenderLoopTests.cs b/tests/Avalonia.Base.UnitTests/Rendering/RenderLoopTests.cs
deleted file mode 100644
index 97740fab00..0000000000
--- a/tests/Avalonia.Base.UnitTests/Rendering/RenderLoopTests.cs
+++ /dev/null
@@ -1,113 +0,0 @@
-using System;
-using System.Threading.Tasks;
-using Avalonia.Rendering;
-using Avalonia.Threading;
-using Moq;
-using Xunit;
-
-namespace Avalonia.Base.UnitTests.Rendering
-{
-    public class RenderLoopTests
-    {
-        [Fact]
-        public void RenderLoop_Update_Runs_On_Dispatcher()
-        {
-            var dispatcher = new Mock<IDispatcher>();
-
-            bool inDispatcher = false;
-
-            dispatcher.Setup(
-                d => d.Post(It.IsAny<Action>(), DispatcherPriority.Render))
-                .Callback((Action a, DispatcherPriority _) =>
-                {
-                    inDispatcher = true;
-                    a();
-                    inDispatcher = false;
-                });
-
-            var timer = new Mock<IRenderTimer>();
-
-            var loop = new RenderLoop(timer.Object, dispatcher.Object);
-
-            var renderTask = new Mock<IRenderLoopTask>();
-
-            renderTask.Setup(t => t.NeedsUpdate).Returns(true);
-            renderTask.Setup(t => t.Update(It.IsAny<TimeSpan>()))
-                .Callback((TimeSpan _) => Assert.True(inDispatcher));
-
-            loop.Add(renderTask.Object);
-
-            timer.Raise(t => t.Tick += null, TimeSpan.Zero);
-
-            renderTask.Verify(t => t.Update(It.IsAny<TimeSpan>()), Times.Once());
-        }
-
-        [Fact]
-        public void RenderLoop_Does_Not_Update_When_No_Tasks_Need_Update()
-        {
-            var dispatcher = new Mock<IDispatcher>();
-            dispatcher.Setup(
-                    d => d.Post(It.IsAny<Action>(), DispatcherPriority.Render))
-                .Callback((Action a, DispatcherPriority _) => a());
-
-            var timer = new Mock<IRenderTimer>();
-            var loop = new RenderLoop(timer.Object, dispatcher.Object);
-            var renderTask = new Mock<IRenderLoopTask>();
-            renderTask.Setup(t => t.NeedsUpdate).Returns(false);
-
-            loop.Add(renderTask.Object);
-            timer.Raise(t => t.Tick += null, TimeSpan.Zero);
-            
-            renderTask.Verify(t => t.Update(It.IsAny<TimeSpan>()), Times.Never());
-        }
-
-        [Fact]
-        public void RenderLoop_Render_Runs_Off_Dispatcher()
-        {
-            var dispatcher = new Mock<IDispatcher>();
-            bool inDispatcher = false;
-            dispatcher.Setup(
-                d => d.Post(It.IsAny<Action>(), DispatcherPriority.Render))
-                .Callback((Action a, DispatcherPriority _) =>
-                {
-                    inDispatcher = true;
-                    a();
-                    inDispatcher = false;
-                });
-
-            var timer = new Mock<IRenderTimer>();
-            var loop = new RenderLoop(timer.Object, dispatcher.Object);
-
-            var renderTask = new Mock<IRenderLoopTask>();
-
-            renderTask.Setup(t => t.NeedsUpdate).Returns(true);
-            renderTask.Setup(t => t.Render())
-                .Callback(() => Assert.False(inDispatcher));
-
-            loop.Add(renderTask.Object);
-            timer.Raise(t => t.Tick += null, TimeSpan.Zero);
-
-            renderTask.Verify(t => t.Update(It.IsAny<TimeSpan>()), Times.Once());
-        }
-        
-        [Fact]
-        public void RenderLoop_Passes_Tick_Count_To_Update()
-        {
-            var dispatcher = new Mock<IDispatcher>();
-            dispatcher.Setup(
-                d => d.Post(It.IsAny<Action>(), DispatcherPriority.Render))
-                .Callback((Action a, DispatcherPriority _) => a());
-
-            var timer = new Mock<IRenderTimer>();
-            var loop = new RenderLoop(timer.Object, dispatcher.Object);
-            var renderTask = new Mock<IRenderLoopTask>();
-            renderTask.Setup(t => t.NeedsUpdate).Returns(true);
-
-            loop.Add(renderTask.Object);
-            var time = new TimeSpan(123456789L);
-            timer.Raise(t => t.Tick += null, time);
-
-            renderTask.Verify(t => t.Update(time), Times.Once());
-        }
-    }
-}
diff --git a/tests/Avalonia.Base.UnitTests/Rendering/SceneGraph/DrawOperationTests.cs b/tests/Avalonia.Base.UnitTests/Rendering/SceneGraph/DrawOperationTests.cs
index 1a5ce0ef94..90685101b1 100644
--- a/tests/Avalonia.Base.UnitTests/Rendering/SceneGraph/DrawOperationTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Rendering/SceneGraph/DrawOperationTests.cs
@@ -25,8 +25,8 @@ namespace Avalonia.Base.UnitTests.Rendering.SceneGraph
             public TestContext()
             {
                 _compositor = new Compositor(new RenderLoop(
-                    new CompositorTestServices.ManualRenderTimer(),
-                    new Dispatcher(new NullDispatcherImpl())), null);
+                        new CompositorTestServices.ManualRenderTimer()), null, false,
+                    new NullCompositorScheduler(), true);
                 Context = new RenderDataDrawingContext(_compositor);
             }
 
diff --git a/tests/Avalonia.Base.UnitTests/Styling/StyleTests.cs b/tests/Avalonia.Base.UnitTests/Styling/StyleTests.cs
index 4f5d1b8ec8..ca6d1e5326 100644
--- a/tests/Avalonia.Base.UnitTests/Styling/StyleTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Styling/StyleTests.cs
@@ -13,7 +13,7 @@ using Xunit;
 
 namespace Avalonia.Base.UnitTests.Styling
 {
-    public class StyleTests
+    public class StyleTests : ScopedTestBase
     {
         [Fact]
         public void Style_With_Only_Type_Selector_Should_Update_Value()
diff --git a/tests/Avalonia.Base.UnitTests/Styling/StyledElementTests.cs b/tests/Avalonia.Base.UnitTests/Styling/StyledElementTests.cs
index 20931bfebc..197dde5cc0 100644
--- a/tests/Avalonia.Base.UnitTests/Styling/StyledElementTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Styling/StyledElementTests.cs
@@ -330,7 +330,7 @@ namespace Avalonia.Base.UnitTests.Styling
         [Fact]
         public void Style_Is_Removed_When_Control_Removed_From_Logical_Tree()
         {
-            var app = UnitTestApplication.Start();
+            using var app = UnitTestApplication.Start();
             var target = new Border();
             var root = new TestRoot
             {
@@ -579,7 +579,7 @@ namespace Avalonia.Base.UnitTests.Styling
         public void SetParent_Does_Not_Crash_Due_To_Reentrancy()
         {
             // Issue #3708
-            var app = UnitTestApplication.Start(TestServices.StyledWindow);
+            using var app = UnitTestApplication.Start(TestServices.StyledWindow);
 
             ContentControl target;
             var root = new TestRoot
diff --git a/tests/Avalonia.Base.UnitTests/Styling/StyledElementTests_Theming.cs b/tests/Avalonia.Base.UnitTests/Styling/StyledElementTests_Theming.cs
index 6ba648af78..93711712d3 100644
--- a/tests/Avalonia.Base.UnitTests/Styling/StyledElementTests_Theming.cs
+++ b/tests/Avalonia.Base.UnitTests/Styling/StyledElementTests_Theming.cs
@@ -12,9 +12,9 @@ using Xunit;
 
 namespace Avalonia.Base.UnitTests.Styling;
 
-public class StyledElementTests_Theming
+public class StyledElementTests_Theming : ScopedTestBase
 {
-    public class InlineTheme
+    public class InlineTheme : ScopedTestBase
     {
         [Fact]
         public void Theme_Is_Applied_When_Attached_To_Logical_Tree()
@@ -342,7 +342,7 @@ public class StyledElementTests_Theming
         }
     }
 
-    public class ImplicitTheme
+    public class ImplicitTheme : ScopedTestBase
     {
         [Fact]
         public void Implicit_Theme_Is_Applied_When_Attached_To_Logical_Tree()
@@ -445,7 +445,7 @@ public class StyledElementTests_Theming
         }
     }
 
-    public class ThemeFromStyle
+    public class ThemeFromStyle : ScopedTestBase
     {
         [Fact]
         public void Theme_Is_Applied_When_Attached_To_Logical_Tree()
diff --git a/tests/Avalonia.Base.UnitTests/VisualTests.cs b/tests/Avalonia.Base.UnitTests/VisualTests.cs
index 11bdc4bc68..0150a06715 100644
--- a/tests/Avalonia.Base.UnitTests/VisualTests.cs
+++ b/tests/Avalonia.Base.UnitTests/VisualTests.cs
@@ -150,7 +150,7 @@ namespace Avalonia.Base.UnitTests
         [Fact]
         public void Attaching_To_Visual_Tree_Should_Invalidate_Visual()
         {
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IRenderer>();
             var child = new Decorator();
             var root = new TestRoot
             {
diff --git a/tests/Avalonia.Controls.UnitTests/ButtonTests.cs b/tests/Avalonia.Controls.UnitTests/ButtonTests.cs
index 2679d4ce06..1d62588ec0 100644
--- a/tests/Avalonia.Controls.UnitTests/ButtonTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ButtonTests.cs
@@ -134,7 +134,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Button_Raises_Click()
         {
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var pt = new Point(50, 50);
             renderer.Setup(r => r.HitTest(It.IsAny<Point>(), It.IsAny<Visual>(), It.IsAny<Func<Visual, bool>>()))
                 .Returns<Point, Visual, Func<Visual, bool>>((p, r, f) =>
@@ -165,7 +165,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Button_Does_Not_Raise_Click_When_PointerReleased_Outside()
         {
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
 
             renderer.Setup(r => r.HitTest(It.IsAny<Point>(), It.IsAny<Visual>(), It.IsAny<Func<Visual, bool>>()))
                 .Returns<Point, Visual, Func<Visual, bool>>((p, r, f) =>
@@ -197,7 +197,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Button_With_RenderTransform_Raises_Click()
         {
-            var renderer = RendererMocks.CreateRenderer();
+            var renderer = new Mock<IHitTester>();
             var pt = new Point(150, 50);
             renderer.Setup(r => r.HitTest(It.IsAny<Point>(), It.IsAny<Visual>(), It.IsAny<Func<Visual, bool>>()))
                 .Returns<Point, Visual, Func<Visual, bool>>((p, r, f) =>
@@ -383,10 +383,11 @@ namespace Avalonia.Controls.UnitTests
 
         private class TestButton : Button, IRenderRoot
         {
-            public TestButton(IRenderer renderer)
+            public TestButton(IHitTester hit)
             {
                 IsVisible = true;
-                Renderer = renderer;
+                HitTester = hit;
+                Renderer = new NullRenderer();
             }
 
             public new Rect Bounds
@@ -398,6 +399,7 @@ namespace Avalonia.Controls.UnitTests
             public Size ClientSize => throw new NotImplementedException();
 
             public IRenderer Renderer { get; }
+            public IHitTester HitTester { get; }
 
             public double RenderScaling => throw new NotImplementedException();
 
diff --git a/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs b/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
index 803cc793fd..7f9735cac0 100644
--- a/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
@@ -5,6 +5,7 @@ using Avalonia.Input;
 using Avalonia.Markup.Xaml;
 using Avalonia.Platform;
 using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
 using Avalonia.UnitTests;
 
 using Moq;
@@ -595,10 +596,10 @@ namespace Avalonia.Controls.UnitTests
 
         private static Window PreparedWindow(object content = null)
         {
-            var renderer = RendererMocks.CreateRenderer();
+            
             var platform = AvaloniaLocator.Current.GetRequiredService<IWindowingPlatform>();
             var windowImpl = Mock.Get(platform.CreateWindow());
-            windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>())).Returns(renderer.Object);
+            windowImpl.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
 
             var w = new Window(windowImpl.Object) { Content = content };
             w.ApplyStyling();
diff --git a/tests/Avalonia.Controls.UnitTests/DesktopStyleApplicationLifetimeTests.cs b/tests/Avalonia.Controls.UnitTests/DesktopStyleApplicationLifetimeTests.cs
index 58811cd081..2ce32564ed 100644
--- a/tests/Avalonia.Controls.UnitTests/DesktopStyleApplicationLifetimeTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/DesktopStyleApplicationLifetimeTests.cs
@@ -5,6 +5,7 @@ using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Controls.Platform;
 using Avalonia.Platform;
 using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
 using Avalonia.Threading;
 using Avalonia.UnitTests;
 using Moq;
@@ -201,8 +202,7 @@ namespace Avalonia.Controls.UnitTests
         public void Impl_Closing_Should_Remove_Window_From_OpenWindows()
         {
             var windowImpl = new Mock<IWindowImpl>();
-            windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(() => RendererMocks.CreateRenderer().Object);
+            windowImpl.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
             windowImpl.SetupProperty(x => x.Closed);
             windowImpl.Setup(x => x.DesktopScaling).Returns(1);
             windowImpl.Setup(x => x.RenderScaling).Returns(1);
diff --git a/tests/Avalonia.Controls.UnitTests/FlyoutTests.cs b/tests/Avalonia.Controls.UnitTests/FlyoutTests.cs
index db12de9db9..e3f5983274 100644
--- a/tests/Avalonia.Controls.UnitTests/FlyoutTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/FlyoutTests.cs
@@ -8,6 +8,7 @@ using Avalonia.Markup.Xaml;
 using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
 using Avalonia.UnitTests;
 using Avalonia.VisualTree;
 
@@ -569,10 +570,9 @@ namespace Avalonia.Controls.UnitTests
 
         private static Window PreparedWindow(object content = null)
         {
-            var renderer = RendererMocks.CreateRenderer();
             var platform = AvaloniaLocator.Current.GetRequiredService<IWindowingPlatform>();
             var windowImpl = Mock.Get(platform.CreateWindow());
-            windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>())).Returns(renderer.Object);
+            windowImpl.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
 
             var w = new Window(windowImpl.Object) { Content = content };
             w.ApplyTemplate();
diff --git a/tests/Avalonia.Controls.UnitTests/GridSplitterTests.cs b/tests/Avalonia.Controls.UnitTests/GridSplitterTests.cs
index 72ccead783..cdb8fb21fe 100644
--- a/tests/Avalonia.Controls.UnitTests/GridSplitterTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/GridSplitterTests.cs
@@ -7,7 +7,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class GridSplitterTests
+    public class GridSplitterTests : ScopedTestBase
     {
         public GridSplitterTests()
         {
diff --git a/tests/Avalonia.Controls.UnitTests/GridTests.cs b/tests/Avalonia.Controls.UnitTests/GridTests.cs
index d372bb2af4..339a4a7cdd 100644
--- a/tests/Avalonia.Controls.UnitTests/GridTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/GridTests.cs
@@ -7,7 +7,7 @@ using Xunit.Abstractions;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class GridTests
+    public class GridTests : ScopedTestBase
     {
         private readonly ITestOutputHelper output;
 
diff --git a/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs b/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs
index 6d0b543ede..687338ece0 100644
--- a/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs
@@ -20,7 +20,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ListBoxTests
+    public class ListBoxTests : ScopedTestBase
     {
         private MouseTestHelper _mouse = new MouseTestHelper();
 
diff --git a/tests/Avalonia.Controls.UnitTests/MaskedTextBoxTests.cs b/tests/Avalonia.Controls.UnitTests/MaskedTextBoxTests.cs
index dead810dbb..55450c3b4f 100644
--- a/tests/Avalonia.Controls.UnitTests/MaskedTextBoxTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/MaskedTextBoxTests.cs
@@ -14,6 +14,7 @@ using Avalonia.Layout;
 using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
 using Avalonia.UnitTests;
 using Moq;
 using Xunit;
@@ -1010,8 +1011,7 @@ namespace Avalonia.Controls.UnitTests
         private static Mock<ITopLevelImpl> CreateMockTopLevelImpl()
         {
             var clipboard = new Mock<ITopLevelImpl>();
-            clipboard.Setup(r => r.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(RendererMocks.CreateRenderer().Object);
+            clipboard.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
             clipboard.Setup(r => r.TryGetFeature(typeof(IClipboard)))
                 .Returns(new ClipboardStub());
             clipboard.SetupGet(x => x.RenderScaling).Returns(1);
diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs b/tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs
index 888162cfee..c1fd79fccc 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs
@@ -565,12 +565,16 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             using (CreateServices())
             {
-                var renderer = RendererMocks.CreateRenderer();
+                var compositor = RendererMocks.CreateDummyCompositor();
                 var platform = AvaloniaLocator.Current.GetRequiredService<IWindowingPlatform>();
                 var windowImpl = Mock.Get(platform.CreateWindow());
-                windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>())).Returns(renderer.Object);
+                windowImpl.Setup(x => x.Compositor).Returns(compositor);
+                var hitTester = new Mock<IHitTester>();
 
-                var window = new Window(windowImpl.Object);
+                var window = new Window(windowImpl.Object)
+                {
+                    HitTesterOverride = hitTester.Object
+                };
                 window.ApplyStyling();
                 window.ApplyTemplate();
 
@@ -585,7 +589,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var border = new Border();
                 window.Content = border;
 
-                renderer.Setup(x =>
+                hitTester.Setup(x =>
                     x.HitTestFirst(new Point(10, 15), window, It.IsAny<Func<Visual, bool>>()))
                     .Returns(border);
 
@@ -751,7 +755,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var window = PreparedWindow(popup);
                 window.Show();
                 popup.Open();
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Layout);
+                Dispatcher.UIThread.RunJobs(DispatcherPriority.AfterRender);
 
                 var raised = false;
                 if (popup.Host is PopupRoot popupRoot)
@@ -774,7 +778,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                     };
                 }
                 window.Position = new PixelPoint(10, 10);
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Layout);
+                Dispatcher.UIThread.RunJobs(DispatcherPriority.AfterRender);
                 Assert.False(raised);
             }
         }
@@ -804,7 +808,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var window = PreparedWindow(placementTarget);
                 window.Show();
                 popup.Open();
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Layout);
+                Dispatcher.UIThread.RunJobs(DispatcherPriority.AfterRender);
 
                 // The target's initial placement is (395,295) which is a 10x10 panel centered in a 800x600 window
                 Assert.Equal(placementTarget.Bounds, new Rect(395D, 295D, 10, 10));
@@ -835,7 +839,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                     };
                 }
                 window.PlatformImpl?.Resize(new Size(700D, 500D), WindowResizeReason.Unspecified);
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Layout);
+                Dispatcher.UIThread.RunJobs(DispatcherPriority.AfterRender);
                 Assert.True(raised);
             }
         }
@@ -865,7 +869,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var window = PreparedWindow(placementTarget);
                 window.Show();
                 popup.Open();
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Layout);
+                Dispatcher.UIThread.RunJobs(DispatcherPriority.AfterRender);
 
                 // The target's initial placement is (395,295) which is a 10x10 panel centered in a 800x600 window
                 Assert.Equal(placementTarget.Bounds, new Rect(395D, 295D, 10, 10));
@@ -891,7 +895,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                     };
                 }
                 window.PlatformImpl?.Resize(new Size(700D, 500D), WindowResizeReason.Unspecified);
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Layout);
+                Dispatcher.UIThread.RunJobs(DispatcherPriority.AfterRender);
                 Assert.False(raised);
             }
         }
@@ -920,7 +924,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var window = PreparedWindow(placementTarget);
                 window.Show();
                 popup.Open();
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Layout);
+                Dispatcher.UIThread.RunJobs();
 
                 // The target's initial placement is (395,295) which is a 10x10 panel centered in a 800x600 window
                 Assert.Equal(placementTarget.Bounds, new Rect(395D, 295D, 10, 10));
@@ -950,7 +954,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                     };
                 }
                 placementTarget.Margin = new Thickness(10, 0, 0, 0);
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Layout);
+                Dispatcher.UIThread.RunJobs();
                 Assert.True(raised);
             }
         }
@@ -980,7 +984,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var window = PreparedWindow(placementTarget);
                 window.Show();
                 popup.Open();
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Layout);
+                Dispatcher.UIThread.RunJobs();
 
                 // The target's initial placement is (395,295) which is a 10x10 panel centered in a 800x600 window
                 Assert.Equal(placementTarget.Bounds, new Rect(395D, 295D, 10, 10));
@@ -1006,7 +1010,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                     };
                 }
                 placementTarget.Margin = new Thickness(10, 0, 0, 0);
-                Dispatcher.UIThread.RunJobs(DispatcherPriority.Layout);
+                Dispatcher.UIThread.RunJobs();
                 Assert.False(raised);
             }
         }
diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs
index 51745e1687..e456f25238 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs
@@ -28,7 +28,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public partial class SelectingItemsControlTests
+    public partial class SelectingItemsControlTests : ScopedTestBase
     {
         private MouseTestHelper _helper = new MouseTestHelper();
 
diff --git a/tests/Avalonia.Controls.UnitTests/ScrollViewerTests.cs b/tests/Avalonia.Controls.UnitTests/ScrollViewerTests.cs
index 94e24e484f..a7628cf243 100644
--- a/tests/Avalonia.Controls.UnitTests/ScrollViewerTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ScrollViewerTests.cs
@@ -13,7 +13,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ScrollViewerTests
+    public class ScrollViewerTests : ScopedTestBase
     {
         private readonly MouseTestHelper _mouse = new();
 
diff --git a/tests/Avalonia.Controls.UnitTests/TextBoxTests.cs b/tests/Avalonia.Controls.UnitTests/TextBoxTests.cs
index 109c233a56..d4558c9e04 100644
--- a/tests/Avalonia.Controls.UnitTests/TextBoxTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/TextBoxTests.cs
@@ -13,6 +13,7 @@ using Avalonia.Layout;
 using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
 using Avalonia.UnitTests;
 using Moq;
 using Xunit;
@@ -1225,8 +1226,7 @@ namespace Avalonia.Controls.UnitTests
         private static Mock<ITopLevelImpl> CreateMockTopLevelImpl()
         {
             var clipboard = new Mock<ITopLevelImpl>();
-            clipboard.Setup(r => r.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(RendererMocks.CreateRenderer().Object);
+            clipboard.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
             clipboard.Setup(r => r.TryGetFeature(typeof(IClipboard)))
                 .Returns(new ClipboardStub());
             clipboard.SetupGet(x => x.RenderScaling).Returns(1);
diff --git a/tests/Avalonia.Controls.UnitTests/TopLevelTests.cs b/tests/Avalonia.Controls.UnitTests/TopLevelTests.cs
index 1c7935e167..a611992ab8 100644
--- a/tests/Avalonia.Controls.UnitTests/TopLevelTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/TopLevelTests.cs
@@ -8,6 +8,7 @@ using Avalonia.Layout;
 using Avalonia.LogicalTree;
 using Avalonia.Platform;
 using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
 using Avalonia.Styling;
 using Avalonia.UnitTests;
 using Moq;
@@ -136,8 +137,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var impl = CreateMockTopLevelImpl();
-                impl.SetupAllProperties();
+                var impl = CreateMockTopLevelImpl(true);
                 impl.Setup(x => x.ClientSize).Returns(new Size(123, 456));
 
                 // The user has resized the window, so we can no longer auto-size.
@@ -154,8 +154,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var impl = CreateMockTopLevelImpl();
-                impl.SetupAllProperties();
+                var impl = CreateMockTopLevelImpl(true);
 
                 bool raised = false;
                 var target = new TestTopLevel(impl.Object);
@@ -172,8 +171,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var impl = CreateMockTopLevelImpl();
-                impl.SetupAllProperties();
+                var impl = CreateMockTopLevelImpl(true);
 
                 var target = new TestTopLevel(impl.Object);
                 var raised = 0;
@@ -203,8 +201,7 @@ namespace Avalonia.Controls.UnitTests
 
             using (UnitTestApplication.Start(services))
             {
-                var impl = CreateMockTopLevelImpl();
-                impl.SetupAllProperties();
+                var impl = CreateMockTopLevelImpl(true);
 
                 var target = new TestTopLevel(impl.Object);
 
@@ -225,8 +222,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var impl = CreateMockTopLevelImpl();
-                impl.SetupAllProperties();
+                var impl = CreateMockTopLevelImpl(true);
                 var target = new TestTopLevel(impl.Object);
                 var child = new TestTopLevel(impl.Object);
 
@@ -243,8 +239,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var impl = CreateMockTopLevelImpl();
-                impl.SetupAllProperties();
+                var impl = CreateMockTopLevelImpl(true);
                 var target = new TestTopLevel(impl.Object);
                 var raised = false;
 
@@ -260,8 +255,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var impl = CreateMockTopLevelImpl();
-                impl.SetupAllProperties();
+                var impl = CreateMockTopLevelImpl(true);
 
                 var layoutManager = new Mock<ILayoutManager>();
                 var target = new TestTopLevel(impl.Object, layoutManager.Object);
@@ -320,12 +314,14 @@ namespace Avalonia.Controls.UnitTests
                 }.RegisterInNameScope(scope));
         }
 
-        private static Mock<ITopLevelImpl> CreateMockTopLevelImpl()
+        private static Mock<ITopLevelImpl> CreateMockTopLevelImpl(bool setupProperties = false)
         {
-            var renderer = new Mock<ITopLevelImpl>();
-            renderer.Setup(r => r.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(RendererMocks.CreateRenderer().Object);
-            return renderer;
+            var topLevel = new Mock<ITopLevelImpl>();
+            if (setupProperties)
+                topLevel.SetupAllProperties();
+            topLevel.Setup(x => x.RenderScaling).Returns(1);
+            topLevel.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
+            return topLevel;
         }
 
         private class TestTopLevel : TopLevel
diff --git a/tests/Avalonia.Controls.UnitTests/TreeViewTests.cs b/tests/Avalonia.Controls.UnitTests/TreeViewTests.cs
index 604ff1c715..f4306f63db 100644
--- a/tests/Avalonia.Controls.UnitTests/TreeViewTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/TreeViewTests.cs
@@ -23,7 +23,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class TreeViewTests
+    public class TreeViewTests : ScopedTestBase
     {
         private readonly MouseTestHelper _mouse = new();
 
diff --git a/tests/Avalonia.Controls.UnitTests/VirtualizingStackPanelTests.cs b/tests/Avalonia.Controls.UnitTests/VirtualizingStackPanelTests.cs
index c5a6ecc376..4be888f96d 100644
--- a/tests/Avalonia.Controls.UnitTests/VirtualizingStackPanelTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/VirtualizingStackPanelTests.cs
@@ -19,7 +19,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class VirtualizingStackPanelTests
+    public class VirtualizingStackPanelTests : ScopedTestBase
     {
         [Fact]
         public void Creates_Initial_Items()
diff --git a/tests/Avalonia.Controls.UnitTests/WindowBaseTests.cs b/tests/Avalonia.Controls.UnitTests/WindowBaseTests.cs
index d65fa06183..1c6495359a 100644
--- a/tests/Avalonia.Controls.UnitTests/WindowBaseTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/WindowBaseTests.cs
@@ -7,8 +7,10 @@ using Avalonia.Controls.Templates;
 using Avalonia.Input;
 using Avalonia.Input.Raw;
 using Avalonia.Layout;
+using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
 using Avalonia.Styling;
 using Avalonia.UnitTests;
 using Xunit;
@@ -36,8 +38,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var impl = CreateMockWindowBaseImpl();
-                impl.SetupAllProperties();
+                var impl = CreateMockWindowBaseImpl(true);
 
                 bool raised = false;
                 var target = new TestWindowBase(impl.Object);
@@ -55,8 +56,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var impl = CreateMockWindowBaseImpl();
-                impl.SetupAllProperties();
+                var impl = CreateMockWindowBaseImpl(true);
 
                 bool raised = false;
                 var target = new TestWindowBase(impl.Object);
@@ -110,8 +110,7 @@ namespace Avalonia.Controls.UnitTests
         public void IsVisible_Should_Be_False_Atfer_Impl_Signals_Close()
         {
             var windowImpl = new Mock<IPopupImpl>();
-            windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(() => RendererMocks.CreateRenderer().Object);
+            windowImpl.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
             windowImpl.Setup(x => x.DesktopScaling).Returns(1);
             windowImpl.Setup(x => x.RenderScaling).Returns(1);
             windowImpl.SetupProperty(x => x.Closed);
@@ -131,8 +130,7 @@ namespace Avalonia.Controls.UnitTests
         public void Setting_IsVisible_True_Shows_Window()
         {
             var windowImpl = new Mock<IPopupImpl>();
-            windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(() => RendererMocks.CreateRenderer().Object);
+            windowImpl.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
             windowImpl.Setup(x => x.DesktopScaling).Returns(1);
             windowImpl.Setup(x => x.RenderScaling).Returns(1);
 
@@ -149,8 +147,7 @@ namespace Avalonia.Controls.UnitTests
         public void Setting_IsVisible_False_Hides_Window()
         {
             var windowImpl = new Mock<IPopupImpl>();
-            windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(() => RendererMocks.CreateRenderer().Object);
+            windowImpl.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
             windowImpl.Setup(x => x.DesktopScaling).Returns(1);
             windowImpl.Setup(x => x.RenderScaling).Returns(1);
 
@@ -169,12 +166,11 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var renderer = RendererMocks.CreateRenderer();
-                var target = new TestWindowBase(renderer.Object);
+                var target = new TestWindowBase();
 
                 target.Show();
 
-                renderer.Verify(x => x.Start(), Times.Once);
+                Assert.True(MediaContext.Instance.IsTopLevelActive(target));
             }
         }
 
@@ -200,13 +196,12 @@ namespace Avalonia.Controls.UnitTests
 
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var renderer = RendererMocks.CreateRenderer();
-                var target = new TestWindowBase(renderer.Object);
+                var target = new TestWindowBase();
 
                 target.Show();
                 target.Hide();
 
-                renderer.Verify(x => x.Stop(), Times.Once);
+                Assert.False(MediaContext.Instance.IsTopLevelActive(target));
             }
         }
 
@@ -215,19 +210,17 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var renderer = RendererMocks.CreateRenderer();
                 var windowImpl = new Mock<IPopupImpl>();
                 windowImpl.Setup(x => x.DesktopScaling).Returns(1);
                 windowImpl.Setup(x => x.RenderScaling).Returns(1);
                 windowImpl.SetupProperty(x => x.Closed);
-                windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>())).Returns(renderer.Object);
+                windowImpl.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
 
                 var target = new TestWindowBase(windowImpl.Object);
 
                 target.Show();
                 windowImpl.Object.Closed();
-
-                renderer.Verify(x => x.Dispose(), Times.Once);
+                Assert.True(((CompositingRenderer)target.Renderer).IsDisposed);
             }
         }
 
@@ -241,11 +234,12 @@ namespace Avalonia.Controls.UnitTests
                 }.RegisterInNameScope(scope));
         }
 
-        private static Mock<IWindowBaseImpl> CreateMockWindowBaseImpl()
+        private static Mock<IWindowBaseImpl> CreateMockWindowBaseImpl(bool setupAllProperties = false)
         {
             var renderer = new Mock<IWindowBaseImpl>();
-            renderer.Setup(r => r.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(RendererMocks.CreateRenderer().Object);
+            if (setupAllProperties)
+                renderer.SetupAllProperties();
+            renderer.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
             return renderer;
         }
 
@@ -253,15 +247,18 @@ namespace Avalonia.Controls.UnitTests
         {
             public bool IsClosed { get; private set; }
 
-            public TestWindowBase(IRenderer renderer = null)
-                : base(CreateWindowsBaseImplMock(renderer ?? RendererMocks.CreateRenderer().Object))
+            public TestWindowBase()
+                : base(CreateWindowsBaseImplMock())
             {
             }
 
-            private static IWindowBaseImpl CreateWindowsBaseImplMock(IRenderer renderer)
-                => Mock.Of<IWindowBaseImpl>(x =>
+            private static IWindowBaseImpl CreateWindowsBaseImplMock()
+            {
+                var compositor = RendererMocks.CreateDummyCompositor();
+                return Mock.Of<IWindowBaseImpl>(x =>
                     x.RenderScaling == 1 &&
-                    x.CreateRenderer(It.IsAny<IRenderRoot>()) == renderer);
+                    x.Compositor == compositor);
+            }
 
             public TestWindowBase(IWindowBaseImpl impl)
                 : base(impl)
diff --git a/tests/Avalonia.Controls.UnitTests/WindowTests.cs b/tests/Avalonia.Controls.UnitTests/WindowTests.cs
index b59f6e03f7..cd45a3d920 100644
--- a/tests/Avalonia.Controls.UnitTests/WindowTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/WindowTests.cs
@@ -1,8 +1,10 @@
 using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
 using Avalonia.UnitTests;
 using Moq;
 using Xunit;
@@ -15,8 +17,7 @@ namespace Avalonia.Controls.UnitTests
         public void Setting_Title_Should_Set_Impl_Title()
         {
             var windowImpl = new Mock<IWindowImpl>();
-            windowImpl.Setup(r => r.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(RendererMocks.CreateRenderer().Object);
+            windowImpl.Setup(r => r.Compositor).Returns(RendererMocks.CreateDummyCompositor());
             var windowingPlatform = new MockWindowingPlatform(() => windowImpl.Object);
 
             using (UnitTestApplication.Start(new TestServices(windowingPlatform: windowingPlatform)))
@@ -100,8 +101,7 @@ namespace Avalonia.Controls.UnitTests
         public void IsVisible_Should_Be_False_After_Impl_Signals_Close()
         {
             var windowImpl = new Mock<IWindowImpl>();
-            windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(() => RendererMocks.CreateRenderer().Object);
+            windowImpl.Setup(r => r.Compositor).Returns(RendererMocks.CreateDummyCompositor());
             windowImpl.SetupProperty(x => x.Closed);
             windowImpl.Setup(x => x.DesktopScaling).Returns(1);
             windowImpl.Setup(x => x.RenderScaling).Returns(1);
@@ -273,12 +273,10 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var renderer = RendererMocks.CreateRenderer();
-                var target = new Window(CreateImpl(renderer));
+                var target = new Window(CreateImpl());
 
                 target.Show();
-
-                renderer.Verify(x => x.Start(), Times.Once);
+                Assert.True(MediaContext.Instance.IsTopLevelActive(target));
             }
         }
 
@@ -288,13 +286,12 @@ namespace Avalonia.Controls.UnitTests
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
                 var parent = new Window();
-                var renderer = RendererMocks.CreateRenderer();
-                var target = new Window(CreateImpl(renderer));
+                var target = new Window(CreateImpl());
 
                 parent.Show();
                 target.ShowDialog<object>(parent);
 
-                renderer.Verify(x => x.Start(), Times.Once);
+                Assert.True(MediaContext.Instance.IsTopLevelActive(target));
             }
         }
 
@@ -321,13 +318,11 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var renderer = RendererMocks.CreateRenderer();
-                var target = new Window(CreateImpl(renderer));
+                var target = new Window(CreateImpl());
 
                 target.Show();
                 target.Hide();
-
-                renderer.Verify(x => x.Stop(), Times.Once);
+                Assert.False(MediaContext.Instance.IsTopLevelActive(target));
             }
         }
 
@@ -338,8 +333,7 @@ namespace Avalonia.Controls.UnitTests
             {
                 var parent = new Window();
                 var windowImpl = new Mock<IWindowImpl>();
-                windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>()))
-                    .Returns(() => RendererMocks.CreateRenderer().Object);
+                windowImpl.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
                 windowImpl.SetupProperty(x => x.Closed);
                 windowImpl.Setup(x => x.DesktopScaling).Returns(1);
                 windowImpl.Setup(x => x.RenderScaling).Returns(1);
@@ -381,8 +375,7 @@ namespace Avalonia.Controls.UnitTests
             {
                 var parent = new Window();
                 var windowImpl = new Mock<IWindowImpl>();
-                windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>()))
-                    .Returns(() => RendererMocks.CreateRenderer().Object);
+                windowImpl.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
                 windowImpl.SetupProperty(x => x.Closed);
                 windowImpl.Setup(x => x.DesktopScaling).Returns(1);
                 windowImpl.Setup(x => x.RenderScaling).Returns(1);
@@ -1054,11 +1047,11 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
-        private static IWindowImpl CreateImpl(Mock<IRenderer> renderer)
+        private static IWindowImpl CreateImpl()
         {
-            return Mock.Of<IWindowImpl>(x =>
-                x.RenderScaling == 1 &&
-                x.CreateRenderer(It.IsAny<IRenderRoot>()) == renderer.Object);
+            var compositor = RendererMocks.CreateDummyCompositor();
+            return Mock.Of<IWindowImpl>(x => x.RenderScaling == 1 &&
+                                             x.Compositor == compositor);
         }
 
         private class ChildControl : Control
diff --git a/tests/Avalonia.LeakTests/ControlTests.cs b/tests/Avalonia.LeakTests/ControlTests.cs
index b3a6b52d68..ab8e4377b6 100644
--- a/tests/Avalonia.LeakTests/ControlTests.cs
+++ b/tests/Avalonia.LeakTests/ControlTests.cs
@@ -16,6 +16,7 @@ using Avalonia.Input;
 using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
 using Avalonia.Styling;
 using Avalonia.Threading;
 using Avalonia.UnitTests;
@@ -462,13 +463,11 @@ namespace Avalonia.LeakTests
         {
             using (Start())
             {
-                var renderer = RendererMocks.CreateRenderer();
-                renderer.Setup(x => x.Dispose());
                 var impl = new Mock<IWindowImpl>();
                 impl.Setup(r => r.TryGetFeature(It.IsAny<Type>())).Returns(null);
                 impl.SetupGet(x => x.RenderScaling).Returns(1);
                 impl.SetupProperty(x => x.Closed);
-                impl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>())).Returns(renderer.Object);
+                impl.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
                 impl.Setup(x => x.Dispose()).Callback(() => impl.Object.Closed());
 
                 AvaloniaLocator.CurrentMutable.Bind<IWindowingPlatform>()
@@ -479,7 +478,7 @@ namespace Avalonia.LeakTests
                 };
                 window.Show();
                 window.Close();
-                renderer.Verify(r => r.Dispose());
+                Assert.True(((CompositingRenderer)window.Renderer).IsDisposed);
             }
         }
 
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Converters/AvaloniaPropertyConverterTest.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Converters/AvaloniaPropertyConverterTest.cs
index 241ebc2d38..52efc62018 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Converters/AvaloniaPropertyConverterTest.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Converters/AvaloniaPropertyConverterTest.cs
@@ -8,7 +8,7 @@ using Xunit;
 
 namespace Avalonia.Markup.Xaml.UnitTests.Converters
 {
-    public class AvaloniaPropertyConverterTest
+    public class AvaloniaPropertyConverterTest : XamlTestBase
     {
         public AvaloniaPropertyConverterTest()
         {
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Converters/PointsListTypeConverterTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Converters/PointsListTypeConverterTests.cs
index 4dada1313e..6664c374bc 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Converters/PointsListTypeConverterTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Converters/PointsListTypeConverterTests.cs
@@ -7,7 +7,7 @@ using Xunit;
 
 namespace Avalonia.Markup.Xaml.UnitTests.Converters
 {
-    public class PointsListTypeConverterTests
+    public class PointsListTypeConverterTests : XamlTestBase
     {
         static PointsListTypeConverterTests()
         {
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlThemeTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlThemeTests.cs
index 1e4c89b33a..e153f1112a 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlThemeTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlThemeTests.cs
@@ -28,7 +28,6 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                 var button = Assert.IsType<TestTemplatedControl>(window.Content);
 
                 window.Show();
-                window.LayoutManager.ExecuteInitialLayoutPass();
 
                 Assert.NotNull(button.Template);
 
@@ -65,7 +64,6 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                 var button = Assert.IsType<TestTemplatedControl>(window.Content);
 
                 window.Show();
-                window.LayoutManager.ExecuteInitialLayoutPass();
 
                 Assert.NotNull(button.Template);
 
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/StyleTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/StyleTests.cs
index 06589beddf..b04beed48d 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/StyleTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/StyleTests.cs
@@ -387,13 +387,13 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                 Assert.Equal(new[] { Brushes.Transparent, Brushes.Green, Brushes.Transparent }, GetColors());
 
                 collection.Remove(Brushes.Green);
-                window.LayoutManager.ExecuteLayoutPass();
+                window.UpdateLayout();
 
                 Assert.Equal(new[] { Brushes.Transparent, Brushes.Blue }, GetColors());
 
                 collection.Add(Brushes.Violet);
                 collection.Add(Brushes.Black);
-                window.LayoutManager.ExecuteLayoutPass();
+                window.UpdateLayout();
 
                 Assert.Equal(new[] { Brushes.Transparent, Brushes.Blue, Brushes.Transparent, Brushes.Black }, GetColors());
             }
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/XamlTestBase.cs b/tests/Avalonia.Markup.Xaml.UnitTests/XamlTestBase.cs
index 26fba7ec57..5531f5e878 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/XamlTestBase.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/XamlTestBase.cs
@@ -2,28 +2,35 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 using System.Text;
 using Avalonia.Controls;
 using Avalonia.Data;
+using Avalonia.UnitTests;
 
 namespace Avalonia.Markup.Xaml.UnitTests
 {
-    public class XamlTestBase
+    static class XamlLoaderInit
     {
-        public XamlTestBase()
+        [ModuleInitializer]
+        public static void Init()
         {
-            // Ensure necessary assemblies are loaded.
             var _ = typeof(Binding);
-            GC.KeepAlive(typeof(ItemsRepeater));
+            GC.KeepAlive(typeof(ItemsRepeater).Assembly);
             if (AvaloniaLocator.Current.GetService<AvaloniaXamlLoader.IRuntimeXamlLoader>() == null)
                 AvaloniaLocator.CurrentMutable.Bind<AvaloniaXamlLoader.IRuntimeXamlLoader>()
                     .ToConstant(new TestXamlLoaderShim());
         }
-        
+
         class TestXamlLoaderShim : AvaloniaXamlLoader.IRuntimeXamlLoader
         {
             public object Load(RuntimeXamlLoaderDocument document, RuntimeXamlLoaderConfiguration configuration) 
                 => AvaloniaRuntimeXamlLoader.Load(document, configuration);
         }
     }
+    
+    public class XamlTestBase : ScopedTestBase
+    {
+
+    }
 }
diff --git a/tests/Avalonia.RenderTests/TestBase.cs b/tests/Avalonia.RenderTests/TestBase.cs
index a925b4e60c..4e4842e856 100644
--- a/tests/Avalonia.RenderTests/TestBase.cs
+++ b/tests/Avalonia.RenderTests/TestBase.cs
@@ -107,14 +107,14 @@ namespace Avalonia.Direct2D1.RenderTests
             
             var timer = new ManualRenderTimer();
 
-            var compositor = new Compositor(new RenderLoop(timer, Dispatcher.UIThread), null);
+            var compositor = new Compositor(new RenderLoop(timer), null, true);
             using (var writableBitmap = factory.CreateWriteableBitmap(pixelSize, dpiVector, factory.DefaultPixelFormat, factory.DefaultAlphaFormat))
             {
                 var root = new TestRenderRoot(dpiVector.X / 96, null!);
                 using (var renderer = new CompositingRenderer(root, compositor, () => new[]
                        {
                            new BitmapFramebufferSurface(writableBitmap)
-                       }) { RenderOnlyOnRenderThread = false })
+                       }))
                 {
                     root.Initialize(renderer, target);
                     renderer.Start();
diff --git a/tests/Avalonia.RenderTests/TestRenderRoot.cs b/tests/Avalonia.RenderTests/TestRenderRoot.cs
index 8f2b324d9c..64fda9ae87 100644
--- a/tests/Avalonia.RenderTests/TestRenderRoot.cs
+++ b/tests/Avalonia.RenderTests/TestRenderRoot.cs
@@ -1,6 +1,7 @@
 using Avalonia.Rendering;
 using System.Threading.Tasks;
 using System;
+using System.Collections.Generic;
 using Avalonia.Controls;
 using Avalonia.Platform;
 
@@ -15,7 +16,9 @@ namespace Avalonia.Direct2D1.RenderTests
     {
         private readonly IRenderTarget _renderTarget;
         public Size ClientSize { get; private set; }
-        public IRenderer Renderer { get; private set; }
+        internal IRenderer Renderer { get; private set; }
+        IRenderer IRenderRoot.Renderer => Renderer;
+        IHitTester IRenderRoot.HitTester => new NullHitTester();
         public double RenderScaling { get; }
 
         public TestRenderRoot(double scaling, IRenderTarget renderTarget)
@@ -23,8 +26,15 @@ namespace Avalonia.Direct2D1.RenderTests
             _renderTarget = renderTarget;
             RenderScaling = scaling;
         }
+        
+        class NullHitTester : IHitTester
+        {
+            public IEnumerable<Visual> HitTest(Point p, Visual root, Func<Visual, bool> filter) => Array.Empty<Visual>();
+
+            public Visual HitTestFirst(Point p, Visual root, Func<Visual, bool> filter) => null;
+        }
 
-        public void Initialize(IRenderer renderer, Control child)
+        internal void Initialize(IRenderer renderer, Control child)
         {
             Renderer = renderer;
             Child = child;
diff --git a/tests/Avalonia.UnitTests/Avalonia.UnitTests.csproj b/tests/Avalonia.UnitTests/Avalonia.UnitTests.csproj
index 0d49f78dd9..8ce0b8a984 100644
--- a/tests/Avalonia.UnitTests/Avalonia.UnitTests.csproj
+++ b/tests/Avalonia.UnitTests/Avalonia.UnitTests.csproj
@@ -22,4 +22,5 @@
   <Import Project="..\..\build\HarfBuzzSharp.props" />
   <Import Project="..\..\build\XUnit.props" />
   <Import Project="..\..\build\SharedVersion.props" />
+  <Import Project="..\..\build\AvaloniaPublicKey.props" />
 </Project>
diff --git a/tests/Avalonia.UnitTests/CompositorTestServices.cs b/tests/Avalonia.UnitTests/CompositorTestServices.cs
index de7cbc873c..7850735178 100644
--- a/tests/Avalonia.UnitTests/CompositorTestServices.cs
+++ b/tests/Avalonia.UnitTests/CompositorTestServices.cs
@@ -22,14 +22,14 @@ public class CompositorTestServices : IDisposable
 {
     private readonly IDisposable _app;
     public Compositor Compositor { get; }
+    internal CompositingRenderer Renderer { get; }
     public ManualRenderTimer Timer { get; } = new();
     public EmbeddableControlRoot TopLevel { get; }
-    public CompositingRenderer Renderer { get; } = null!;
     public DebugEvents Events { get; } = new();
 
     public void Dispose()
     {
-        TopLevel.Renderer.Stop();
+        TopLevel.StopRendering();
         TopLevel.Dispose();
         _app.Dispose();
     }
@@ -44,10 +44,8 @@ public class CompositorTestServices : IDisposable
         try
         {
             AvaloniaLocator.CurrentMutable.Bind<IRenderTimer>().ToConstant(Timer);
-            AvaloniaLocator.CurrentMutable.Bind<IRenderLoop>()
-                .ToConstant(new RenderLoop(Timer, Dispatcher.UIThread));
 
-            Compositor = new Compositor(AvaloniaLocator.Current.GetRequiredService<IRenderLoop>(), null);
+            Compositor = new Compositor(new RenderLoop(Timer), null);
             var impl = new TopLevelImpl(Compositor, size ?? new Size(1000, 1000));
             TopLevel = new EmbeddableControlRoot(impl)
             {
@@ -61,10 +59,10 @@ public class CompositorTestServices : IDisposable
                     return presenter;
                 })
             };
-            Renderer = impl.Renderer;
             TopLevel.Prepare();
-            TopLevel.Renderer.Start();
+            TopLevel.StartRendering();
             RunJobs();
+            Renderer = ((CompositingRenderer)TopLevel.Renderer);
             Renderer.CompositionTarget.Server.DebugEvents = Events;
         }
         catch
@@ -133,7 +131,6 @@ public class CompositorTestServices : IDisposable
     class TopLevelImpl : ITopLevelImpl
     {
         private readonly Compositor _compositor;
-        public CompositingRenderer Renderer { get; private set; }
 
         public TopLevelImpl(Compositor compositor, Size clientSize)
         {
@@ -166,10 +163,7 @@ public class CompositorTestServices : IDisposable
             }
         }
 
-        public IRenderer CreateRenderer(IRenderRoot root)
-        {
-            return Renderer = new CompositingRenderer(root, _compositor, () => Surfaces);
-        }
+        public Compositor Compositor => _compositor;
 
         public void Invalidate(Rect rect)
         {
@@ -207,3 +201,11 @@ public class CompositorTestServices : IDisposable
         public object TryGetFeature(Type featureType) => null;
     }
 }
+
+public class NullCompositorScheduler : ICompositorScheduler
+{
+    public void CommitRequested(Compositor compositor)
+    {
+        
+    }
+}
\ No newline at end of file
diff --git a/tests/Avalonia.UnitTests/InternalsVisibleTo.cs b/tests/Avalonia.UnitTests/InternalsVisibleTo.cs
new file mode 100644
index 0000000000..c989c25310
--- /dev/null
+++ b/tests/Avalonia.UnitTests/InternalsVisibleTo.cs
@@ -0,0 +1,11 @@
+[assembly:System.Runtime.CompilerServices.InternalsVisibleTo("Avalonia.Base.UnitTests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c1bba1142285fe0419326fb25866ba62c47e6c2b5c1ab0c95b46413fad375471232cb81706932e1cef38781b9ebd39d5100401bacb651c6c5bbf59e571e81b3bc08d2a622004e08b1a6ece82a7e0b9857525c86d2b95fab4bc3dce148558d7f3ae61aa3a234086902aeface87d9dfdd32b9d2fe3c6dd4055b5ab4b104998bd87")]
+[assembly:System.Runtime.CompilerServices.InternalsVisibleTo("Avalonia.Controls.UnitTests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c1bba1142285fe0419326fb25866ba62c47e6c2b5c1ab0c95b46413fad375471232cb81706932e1cef38781b9ebd39d5100401bacb651c6c5bbf59e571e81b3bc08d2a622004e08b1a6ece82a7e0b9857525c86d2b95fab4bc3dce148558d7f3ae61aa3a234086902aeface87d9dfdd32b9d2fe3c6dd4055b5ab4b104998bd87")]
+[assembly:System.Runtime.CompilerServices.InternalsVisibleTo("Avalonia.Benchmarks, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c1bba1142285fe0419326fb25866ba62c47e6c2b5c1ab0c95b46413fad375471232cb81706932e1cef38781b9ebd39d5100401bacb651c6c5bbf59e571e81b3bc08d2a622004e08b1a6ece82a7e0b9857525c86d2b95fab4bc3dce148558d7f3ae61aa3a234086902aeface87d9dfdd32b9d2fe3c6dd4055b5ab4b104998bd87")]
+[assembly:System.Runtime.CompilerServices.InternalsVisibleTo("Avalonia.Markup.UnitTests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c1bba1142285fe0419326fb25866ba62c47e6c2b5c1ab0c95b46413fad375471232cb81706932e1cef38781b9ebd39d5100401bacb651c6c5bbf59e571e81b3bc08d2a622004e08b1a6ece82a7e0b9857525c86d2b95fab4bc3dce148558d7f3ae61aa3a234086902aeface87d9dfdd32b9d2fe3c6dd4055b5ab4b104998bd87")]
+[assembly:System.Runtime.CompilerServices.InternalsVisibleTo("Avalonia.Markup.Xaml.UnitTests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c1bba1142285fe0419326fb25866ba62c47e6c2b5c1ab0c95b46413fad375471232cb81706932e1cef38781b9ebd39d5100401bacb651c6c5bbf59e571e81b3bc08d2a622004e08b1a6ece82a7e0b9857525c86d2b95fab4bc3dce148558d7f3ae61aa3a234086902aeface87d9dfdd32b9d2fe3c6dd4055b5ab4b104998bd87")]
+[assembly:System.Runtime.CompilerServices.InternalsVisibleTo("Avalonia.LeakTests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c1bba1142285fe0419326fb25866ba62c47e6c2b5c1ab0c95b46413fad375471232cb81706932e1cef38781b9ebd39d5100401bacb651c6c5bbf59e571e81b3bc08d2a622004e08b1a6ece82a7e0b9857525c86d2b95fab4bc3dce148558d7f3ae61aa3a234086902aeface87d9dfdd32b9d2fe3c6dd4055b5ab4b104998bd87")]
+[assembly:System.Runtime.CompilerServices.InternalsVisibleTo("Avalonia.Skia.UnitTests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c1bba1142285fe0419326fb25866ba62c47e6c2b5c1ab0c95b46413fad375471232cb81706932e1cef38781b9ebd39d5100401bacb651c6c5bbf59e571e81b3bc08d2a622004e08b1a6ece82a7e0b9857525c86d2b95fab4bc3dce148558d7f3ae61aa3a234086902aeface87d9dfdd32b9d2fe3c6dd4055b5ab4b104998bd87")]
+[assembly:System.Runtime.CompilerServices.InternalsVisibleTo("Avalonia.Direct2D.UnitTests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c1bba1142285fe0419326fb25866ba62c47e6c2b5c1ab0c95b46413fad375471232cb81706932e1cef38781b9ebd39d5100401bacb651c6c5bbf59e571e81b3bc08d2a622004e08b1a6ece82a7e0b9857525c86d2b95fab4bc3dce148558d7f3ae61aa3a234086902aeface87d9dfdd32b9d2fe3c6dd4055b5ab4b104998bd87")]
+
+
+
diff --git a/tests/Avalonia.UnitTests/MockGlobalClock.cs b/tests/Avalonia.UnitTests/MockGlobalClock.cs
index b53e5acc01..81aa1bbc97 100644
--- a/tests/Avalonia.UnitTests/MockGlobalClock.cs
+++ b/tests/Avalonia.UnitTests/MockGlobalClock.cs
@@ -3,7 +3,7 @@ using Avalonia.Animation;
 
 namespace Avalonia.UnitTests
 {
-    public class MockGlobalClock : ClockBase, IGlobalClock
+    internal class MockGlobalClock : ClockBase, IGlobalClock
     {
         public new void Pulse(TimeSpan systemTime) => base.Pulse(systemTime);
     }
diff --git a/tests/Avalonia.UnitTests/MockWindowingPlatform.cs b/tests/Avalonia.UnitTests/MockWindowingPlatform.cs
index 5451773da4..abd200ec7c 100644
--- a/tests/Avalonia.UnitTests/MockWindowingPlatform.cs
+++ b/tests/Avalonia.UnitTests/MockWindowingPlatform.cs
@@ -4,6 +4,7 @@ using Moq;
 using Avalonia.Platform;
 using Avalonia.Rendering;
 using Avalonia.Controls;
+using Avalonia.Rendering.Composition;
 
 namespace Avalonia.UnitTests
 {
@@ -27,8 +28,8 @@ namespace Avalonia.UnitTests
             var clientSize = new Size(initialWidth,  initialHeight);
 
             windowImpl.SetupAllProperties();
-            windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(() => RendererMocks.CreateRenderer().Object);
+            var compositor = RendererMocks.CreateDummyCompositor();
+            windowImpl.Setup(x => x.Compositor).Returns(compositor);
             windowImpl.Setup(x => x.ClientSize).Returns(() => clientSize);
             windowImpl.Setup(x => x.MaxAutoSizeHint).Returns(s_screenSize);
             windowImpl.Setup(x => x.DesktopScaling).Returns(1);
@@ -97,8 +98,8 @@ namespace Avalonia.UnitTests
             var positioner = new ManagedPopupPositioner(positionerHelper);
 
             popupImpl.SetupAllProperties();
-            popupImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>()))
-                .Returns(() => RendererMocks.CreateRenderer().Object);
+            var compositor = RendererMocks.CreateDummyCompositor();
+            popupImpl.Setup(x => x.Compositor).Returns(compositor);
             popupImpl.Setup(x => x.ClientSize).Returns(() => clientSize);
             popupImpl.Setup(x => x.MaxAutoSizeHint).Returns(s_screenSize);
             popupImpl.Setup(x => x.RenderScaling).Returns(1);
diff --git a/tests/Avalonia.UnitTests/RendererMocks.cs b/tests/Avalonia.UnitTests/RendererMocks.cs
index d4808a7556..ba9bf31950 100644
--- a/tests/Avalonia.UnitTests/RendererMocks.cs
+++ b/tests/Avalonia.UnitTests/RendererMocks.cs
@@ -1,15 +1,34 @@
-using Avalonia.Rendering;
+using Avalonia.Media;
+using Avalonia.Platform;
+using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
+using Avalonia.Threading;
 using Moq;
 
 namespace Avalonia.UnitTests
 {
     public static class RendererMocks
     {
-        public static Mock<IRenderer> CreateRenderer()
+        internal static Mock<IRenderer> CreateRenderer()
         {
             var renderer = new Mock<IRenderer>();
             renderer.SetupGet(r => r.Diagnostics).Returns(new RendererDiagnostics());
             return renderer;
         }
+
+        public static Compositor CreateDummyCompositor() =>
+            new(new RenderLoop(new CompositorTestServices.ManualRenderTimer()), null, false,
+                new CompositionCommitScheduler(), true);
+
+        class CompositionCommitScheduler : ICompositorScheduler
+        {
+            public void CommitRequested(Compositor compositor)
+            {
+                if (AvaloniaLocator.Current.GetService<IPlatformRenderInterface>() == null)
+                    return;
+                
+                Dispatcher.UIThread.Post(() => compositor.Commit(), DispatcherPriority.AfterRender);
+            }
+        }
     }
 }
diff --git a/tests/Avalonia.UnitTests/ScopedTestBase.cs b/tests/Avalonia.UnitTests/ScopedTestBase.cs
new file mode 100644
index 0000000000..1e597e8e89
--- /dev/null
+++ b/tests/Avalonia.UnitTests/ScopedTestBase.cs
@@ -0,0 +1,18 @@
+using System;
+
+namespace Avalonia.UnitTests;
+
+public class ScopedTestBase : IDisposable
+{
+    private readonly IDisposable _scope;
+
+    public ScopedTestBase()
+    {
+        _scope = AvaloniaLocator.EnterScope();
+    }
+    
+    public virtual void Dispose()
+    {
+        _scope.Dispose();
+    }
+}
\ No newline at end of file
diff --git a/tests/Avalonia.UnitTests/TestRoot.cs b/tests/Avalonia.UnitTests/TestRoot.cs
index 80f0cf5406..569e5d114c 100644
--- a/tests/Avalonia.UnitTests/TestRoot.cs
+++ b/tests/Avalonia.UnitTests/TestRoot.cs
@@ -1,3 +1,5 @@
+using System;
+using System.Collections.Generic;
 using Avalonia.Controls;
 using Avalonia.Input;
 using Avalonia.Layout;
@@ -17,11 +19,19 @@ namespace Avalonia.UnitTests
         public TestRoot()
         {
             Renderer = RendererMocks.CreateRenderer().Object;
+            HitTester = new NullHitTester();
             LayoutManager = new LayoutManager(this);
             IsVisible = true;
             KeyboardNavigation.SetTabNavigation(this, KeyboardNavigationMode.Cycle);
         }
 
+        class NullHitTester : IHitTester
+        {
+            public IEnumerable<Visual> HitTest(Point p, Visual root, Func<Visual, bool> filter) => Array.Empty<Visual>();
+
+            public Visual HitTestFirst(Point p, Visual root, Func<Visual, bool> filter) => null;
+        }
+
         public TestRoot(Control child)
             : this(false, child)
         {
@@ -45,11 +55,15 @@ namespace Avalonia.UnitTests
 
         public double LayoutScaling { get; set; } = 1;
 
-        public ILayoutManager LayoutManager { get; set; }
+        internal ILayoutManager LayoutManager { get; set; }
+        ILayoutManager ILayoutRoot.LayoutManager => LayoutManager;
 
         public double RenderScaling => 1;
 
-        public IRenderer Renderer { get; set; }
+        internal IRenderer Renderer { get; set; }
+        internal IHitTester HitTester { get; set; }
+        IRenderer IRenderRoot.Renderer => Renderer;
+        IHitTester IRenderRoot.HitTester => HitTester;
 
         public IKeyboardNavigationHandler KeyboardNavigationHandler => null;
         public IFocusManager FocusManager => AvaloniaLocator.Current.GetService<IFocusManager>();
diff --git a/tests/Avalonia.UnitTests/TestServices.cs b/tests/Avalonia.UnitTests/TestServices.cs
index f226a7ef55..95a1436ac9 100644
--- a/tests/Avalonia.UnitTests/TestServices.cs
+++ b/tests/Avalonia.UnitTests/TestServices.cs
@@ -65,7 +65,6 @@ namespace Avalonia.UnitTests
         public TestServices(
             IAssetLoader assetLoader = null,
             IFocusManager focusManager = null,
-            IGlobalClock globalClock = null,
             IInputManager inputManager = null,
             Func<IKeyboardDevice> keyboardDevice = null,
             IKeyboardNavigationHandler keyboardNavigation = null,
@@ -83,7 +82,6 @@ namespace Avalonia.UnitTests
         {
             AssetLoader = assetLoader;
             FocusManager = focusManager;
-            GlobalClock = globalClock;
             InputManager = inputManager;
             KeyboardDevice = keyboardDevice;
             KeyboardNavigation = keyboardNavigation;
@@ -99,10 +97,35 @@ namespace Avalonia.UnitTests
             WindowingPlatform = windowingPlatform;
         }
 
+        internal TestServices(
+            IGlobalClock globalClock,
+            IAssetLoader assetLoader = null,
+            IFocusManager focusManager = null,
+            IInputManager inputManager = null,
+            Func<IKeyboardDevice> keyboardDevice = null,
+            IKeyboardNavigationHandler keyboardNavigation = null,
+            Func<IMouseDevice> mouseDevice = null,
+            IRuntimePlatform platform = null,
+            IPlatformRenderInterface renderInterface = null,
+            IRenderTimer renderLoop = null,
+            ICursorFactory standardCursorFactory = null,
+            Func<IStyle> theme = null,
+            IDispatcherImpl dispatcherImpl = null,
+            IFontManagerImpl fontManagerImpl = null,
+            ITextShaperImpl textShaperImpl = null,
+            IWindowImpl windowImpl = null,
+            IWindowingPlatform windowingPlatform = null) : this(assetLoader, focusManager, inputManager, keyboardDevice,
+            keyboardNavigation,
+            mouseDevice, platform, renderInterface, renderLoop, standardCursorFactory, theme,
+            dispatcherImpl, fontManagerImpl, textShaperImpl, windowImpl, windowingPlatform)
+        {
+            GlobalClock = globalClock;
+        }
+
         public IAssetLoader AssetLoader { get; }
         public IInputManager InputManager { get; }
         public IFocusManager FocusManager { get; }
-        public IGlobalClock GlobalClock { get; }
+        internal IGlobalClock GlobalClock { get; set; }
         public Func<IKeyboardDevice> KeyboardDevice { get; }
         public IKeyboardNavigationHandler KeyboardNavigation { get; }
         public Func<IMouseDevice> MouseDevice { get; }
@@ -116,10 +139,9 @@ namespace Avalonia.UnitTests
         public IWindowImpl WindowImpl { get; }
         public IWindowingPlatform WindowingPlatform { get; }
 
-        public TestServices With(
+        internal TestServices With(
             IAssetLoader assetLoader = null,
             IFocusManager focusManager = null,
-            IGlobalClock globalClock = null,
             IInputManager inputManager = null,
             Func<IKeyboardDevice> keyboardDevice = null,
             IKeyboardNavigationHandler keyboardNavigation = null,
@@ -134,12 +156,13 @@ namespace Avalonia.UnitTests
             IFontManagerImpl fontManagerImpl = null,
             ITextShaperImpl textShaperImpl = null,
             IWindowImpl windowImpl = null,
-            IWindowingPlatform windowingPlatform = null)
+            IWindowingPlatform windowingPlatform = null,
+            IGlobalClock globalClock = null)
         {
             return new TestServices(
+                globalClock ?? GlobalClock,
                 assetLoader: assetLoader ?? AssetLoader,
                 focusManager: focusManager ?? FocusManager,
-                globalClock: globalClock ?? GlobalClock,
                 inputManager: inputManager ?? InputManager,
                 keyboardDevice: keyboardDevice ?? KeyboardDevice,
                 keyboardNavigation: keyboardNavigation ?? KeyboardNavigation,

From 11ef16c4be94f023ce0d994175b96564e5dda96a Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 May 2023 14:41:38 +0600
Subject: [PATCH 02/12] Fix build?

---
 src/Browser/Avalonia.Browser/AvaloniaView.cs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Browser/Avalonia.Browser/AvaloniaView.cs b/src/Browser/Avalonia.Browser/AvaloniaView.cs
index 8e1f643b3e..b5dd08d854 100644
--- a/src/Browser/Avalonia.Browser/AvaloniaView.cs
+++ b/src/Browser/Avalonia.Browser/AvaloniaView.cs
@@ -12,6 +12,7 @@ using Avalonia.Controls.Platform;
 using Avalonia.Input;
 using Avalonia.Input.Raw;
 using Avalonia.Input.TextInput;
+using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Rendering.Composition;
 using Avalonia.Threading;
@@ -472,7 +473,7 @@ namespace Avalonia.Browser
 
             if (_topLevel.Renderer is CompositingRenderer dr)
             {
-                dr.CompositionTarget.ImmediateUIThreadRender();
+                MediaContext.Instance.ImmediateRenderRequested(dr.CompositionTarget);
             }
         }
 

From b56bf1c52751d3bca6ccecb1ce634999c92df7e1 Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 May 2023 15:05:22 +0600
Subject: [PATCH 03/12] More scoping for tests

---
 src/Avalonia.Base/Threading/Dispatcher.Queue.cs      |  5 +++++
 .../Rendering/CompositorTestsBase.cs                 |  2 +-
 tests/Avalonia.Markup.Xaml.UnitTests/XamlTestBase.cs | 12 +++++++-----
 tests/Avalonia.UnitTests/ScopedTestBase.cs           |  4 ++++
 4 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/Avalonia.Base/Threading/Dispatcher.Queue.cs b/src/Avalonia.Base/Threading/Dispatcher.Queue.cs
index 78a0740e56..829ab4cf87 100644
--- a/src/Avalonia.Base/Threading/Dispatcher.Queue.cs
+++ b/src/Avalonia.Base/Threading/Dispatcher.Queue.cs
@@ -83,6 +83,11 @@ public partial class Dispatcher
         {
         }
     }
+
+    internal static void ResetBeforeUnitTests()
+    {
+        s_uiThread = null;
+    }
     
     internal static void ResetForUnitTests()
     {
diff --git a/tests/Avalonia.Base.UnitTests/Rendering/CompositorTestsBase.cs b/tests/Avalonia.Base.UnitTests/Rendering/CompositorTestsBase.cs
index fed193e973..2cb181778b 100644
--- a/tests/Avalonia.Base.UnitTests/Rendering/CompositorTestsBase.cs
+++ b/tests/Avalonia.Base.UnitTests/Rendering/CompositorTestsBase.cs
@@ -22,7 +22,7 @@ using Xunit;
 
 namespace Avalonia.Base.UnitTests.Rendering;
 
-public class CompositorTestsBase
+public class CompositorTestsBase : ScopedTestBase
 {
     protected class CompositorCanvas : CompositorTestServices
     {
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/XamlTestBase.cs b/tests/Avalonia.Markup.Xaml.UnitTests/XamlTestBase.cs
index 5531f5e878..0e0893fe8d 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/XamlTestBase.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/XamlTestBase.cs
@@ -17,6 +17,13 @@ namespace Avalonia.Markup.Xaml.UnitTests
         {
             var _ = typeof(Binding);
             GC.KeepAlive(typeof(ItemsRepeater).Assembly);
+        }
+    }
+    
+    public class XamlTestBase : ScopedTestBase
+    {
+        public XamlTestBase()
+        {
             if (AvaloniaLocator.Current.GetService<AvaloniaXamlLoader.IRuntimeXamlLoader>() == null)
                 AvaloniaLocator.CurrentMutable.Bind<AvaloniaXamlLoader.IRuntimeXamlLoader>()
                     .ToConstant(new TestXamlLoaderShim());
@@ -28,9 +35,4 @@ namespace Avalonia.Markup.Xaml.UnitTests
                 => AvaloniaRuntimeXamlLoader.Load(document, configuration);
         }
     }
-    
-    public class XamlTestBase : ScopedTestBase
-    {
-
-    }
 }
diff --git a/tests/Avalonia.UnitTests/ScopedTestBase.cs b/tests/Avalonia.UnitTests/ScopedTestBase.cs
index 1e597e8e89..c319a9ba84 100644
--- a/tests/Avalonia.UnitTests/ScopedTestBase.cs
+++ b/tests/Avalonia.UnitTests/ScopedTestBase.cs
@@ -1,4 +1,5 @@
 using System;
+using Avalonia.Threading;
 
 namespace Avalonia.UnitTests;
 
@@ -8,11 +9,14 @@ public class ScopedTestBase : IDisposable
 
     public ScopedTestBase()
     {
+        AvaloniaLocator.Current = AvaloniaLocator.CurrentMutable = new AvaloniaLocator();
+        Dispatcher.ResetBeforeUnitTests();
         _scope = AvaloniaLocator.EnterScope();
     }
     
     public virtual void Dispose()
     {
+        Dispatcher.ResetForUnitTests();
         _scope.Dispose();
     }
 }
\ No newline at end of file

From b6e9cb808d423502cc2fbdb7f84046665a23ca86 Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 May 2023 15:29:00 +0600
Subject: [PATCH 04/12] More state reset

---
 tests/Avalonia.UnitTests/ScopedTestBase.cs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/Avalonia.UnitTests/ScopedTestBase.cs b/tests/Avalonia.UnitTests/ScopedTestBase.cs
index c319a9ba84..81f4e87032 100644
--- a/tests/Avalonia.UnitTests/ScopedTestBase.cs
+++ b/tests/Avalonia.UnitTests/ScopedTestBase.cs
@@ -1,4 +1,6 @@
 using System;
+using System.Threading;
+using Avalonia.Controls;
 using Avalonia.Threading;
 
 namespace Avalonia.UnitTests;
@@ -11,6 +13,7 @@ public class ScopedTestBase : IDisposable
     {
         AvaloniaLocator.Current = AvaloniaLocator.CurrentMutable = new AvaloniaLocator();
         Dispatcher.ResetBeforeUnitTests();
+        Control.ResetLoadedQueueForUnitTests();
         _scope = AvaloniaLocator.EnterScope();
     }
     

From 0f9f843462bd1ef9551fc0765c66cb7f3bd454f8 Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 May 2023 15:29:15 +0600
Subject: [PATCH 05/12] Remove input marker flag

---
 src/Avalonia.Base/Media/MediaContext.cs | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/src/Avalonia.Base/Media/MediaContext.cs b/src/Avalonia.Base/Media/MediaContext.cs
index 0dfe19f55b..5bd4a51102 100644
--- a/src/Avalonia.Base/Media/MediaContext.cs
+++ b/src/Avalonia.Base/Media/MediaContext.cs
@@ -24,7 +24,6 @@ internal partial class MediaContext : ICompositorScheduler
     private readonly Dictionary<Compositor, Batch> _pendingCompositionBatches = new();
     private record  TopLevelInfo(Compositor Compositor, CompositingRenderer Renderer, ILayoutManager LayoutManager);
     private readonly HashSet<LayoutManager> _queuedLayoutManagers = new();
-    public static bool InputMarkerEnabled = true;
 
     private Dictionary<object, TopLevelInfo> _topLevels = new();
 
@@ -67,18 +66,16 @@ internal partial class MediaContext : ICompositorScheduler
         
         var priority = DispatcherPriority.Render;
         
-        if (InputMarkerEnabled)
+        if (_inputMarkerOp == null)
         {
-            if (_inputMarkerOp == null)
-            {
-                _inputMarkerOp = Dispatcher.UIThread.InvokeAsync(_inputMarkerHandler, DispatcherPriority.Input);
-                _inputMarkerAddedAt = _time.Elapsed;
-            }
-            else if (!now && (_time.Elapsed - _inputMarkerAddedAt).TotalSeconds > MaxSecondsWithoutInput)
-            {
-                priority = DispatcherPriority.Input;
-            }
+            _inputMarkerOp = Dispatcher.UIThread.InvokeAsync(_inputMarkerHandler, DispatcherPriority.Input);
+            _inputMarkerAddedAt = _time.Elapsed;
         }
+        else if (!now && (_time.Elapsed - _inputMarkerAddedAt).TotalSeconds > MaxSecondsWithoutInput)
+        {
+            priority = DispatcherPriority.Input;
+        }
+        
 
         _nextRenderOp = Dispatcher.UIThread.InvokeAsync(_render, priority);
     }

From 189ae7bab6787ce9b55bd8820537f047f64f19bb Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 May 2023 16:24:15 +0600
Subject: [PATCH 06/12] fix win32 interop build

---
 .../Avalonia.Win32.Interop/Avalonia.Win32.Interop.csproj  | 1 +
 src/Windows/Avalonia.Win32.Interop/Wpf/WpfTopLevelImpl.cs | 8 +-------
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/src/Windows/Avalonia.Win32.Interop/Avalonia.Win32.Interop.csproj b/src/Windows/Avalonia.Win32.Interop/Avalonia.Win32.Interop.csproj
index 60bb75a342..08c4f85dc8 100644
--- a/src/Windows/Avalonia.Win32.Interop/Avalonia.Win32.Interop.csproj
+++ b/src/Windows/Avalonia.Win32.Interop/Avalonia.Win32.Interop.csproj
@@ -5,6 +5,7 @@
     <UseWpf>true</UseWpf>
     <UseWindowsForms>true</UseWindowsForms>
     <ExtrasEnableImplicitWinFormsReferences>true</ExtrasEnableImplicitWinFormsReferences>
+    <EnableWindowsTargeting>true</EnableWindowsTargeting>
     <UseDirect3D9>true</UseDirect3D9>
     <PackageId>Avalonia.Win32.Interoperability</PackageId>
   </PropertyGroup>
diff --git a/src/Windows/Avalonia.Win32.Interop/Wpf/WpfTopLevelImpl.cs b/src/Windows/Avalonia.Win32.Interop/Wpf/WpfTopLevelImpl.cs
index 8025779c90..7c7dfa7969 100644
--- a/src/Windows/Avalonia.Win32.Interop/Wpf/WpfTopLevelImpl.cs
+++ b/src/Windows/Avalonia.Win32.Interop/Wpf/WpfTopLevelImpl.cs
@@ -81,12 +81,6 @@ namespace Avalonia.Win32.Interop.Wpf
             _ttl.ScalingChanged?.Invoke(_ttl.RenderScaling);
         }
 
-        
-        public IRenderer CreateRenderer(IRenderRoot root)
-        {
-            return new CompositingRenderer(root, Win32Platform.Compositor, () => _surfaces);
-        }
-
         public void Dispose()
         {
             _ttl.Closed?.Invoke();
@@ -128,7 +122,7 @@ namespace Avalonia.Win32.Interop.Wpf
         }
 
 
-
+        public Compositor Compositor => Win32Platform.Compositor;
         void ITopLevelImpl.SetInputRoot(IInputRoot inputRoot) => _inputRoot = inputRoot;
 
         Point ITopLevelImpl.PointToClient(PixelPoint point) => PointFromScreen(point.ToWpfPoint()).ToAvaloniaPoint();

From ba07b5461b4765eba5c6b92f66aadccf97f14a7c Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 May 2023 16:24:33 +0600
Subject: [PATCH 07/12] Scoping

---
 .../SceneGraph/DrawOperationTests.cs          | 25 +++++++++++--------
 .../CompositorTestServices.cs                 |  1 -
 tests/Avalonia.UnitTests/ScopedTestBase.cs    |  2 ++
 3 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/tests/Avalonia.Base.UnitTests/Rendering/SceneGraph/DrawOperationTests.cs b/tests/Avalonia.Base.UnitTests/Rendering/SceneGraph/DrawOperationTests.cs
index 90685101b1..5c6115f8c8 100644
--- a/tests/Avalonia.Base.UnitTests/Rendering/SceneGraph/DrawOperationTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Rendering/SceneGraph/DrawOperationTests.cs
@@ -14,7 +14,7 @@ using Xunit;
 
 namespace Avalonia.Base.UnitTests.Rendering.SceneGraph
 {  
-    public class DrawOperationTests
+    public class DrawOperationTests : ScopedTestBase
     {
 
         class TestContext
@@ -22,11 +22,9 @@ namespace Avalonia.Base.UnitTests.Rendering.SceneGraph
             private readonly Compositor _compositor;
             public RenderDataDrawingContext Context { get; }
 
-            public TestContext()
+            public TestContext(CompositorTestServices services)
             {
-                _compositor = new Compositor(new RenderLoop(
-                        new CompositorTestServices.ManualRenderTimer()), null, false,
-                    new NullCompositorScheduler(), true);
+                _compositor = services.Compositor;
                 Context = new RenderDataDrawingContext(_compositor);
             }
 
@@ -46,10 +44,17 @@ namespace Avalonia.Base.UnitTests.Rendering.SceneGraph
             }
         }
 
+        private CompositorTestServices _services = new();
+        public override void Dispose()
+        {
+            _services.Dispose();
+            base.Dispose();
+        }
+
         [Fact]
         public void Empty_Bounds_Remain_Empty()
         {
-            var ctx = new TestContext();
+            var ctx = new TestContext(_services);
             ctx.Context.DrawRectangle(Brushes.Black, null, default);
             
             Assert.Null(ctx.GetBounds());
@@ -72,7 +77,7 @@ namespace Avalonia.Base.UnitTests.Rendering.SceneGraph
             double expectedWidth,
             double expectedHeight)
         {
-            var ctx = new TestContext();
+            var ctx = new TestContext(_services);
             using (ctx.Context.PushTransform(Matrix.CreateScale(scaleX, scaleY)))
                 ctx.Context.DrawRectangle(null, new ImmutablePen(Brushes.Black, penThickness), new Rect(x, y, width, height));
 
@@ -84,7 +89,7 @@ namespace Avalonia.Base.UnitTests.Rendering.SceneGraph
         {
             var bitmap = RefCountable.Create(Mock.Of<IBitmapImpl>());
 
-            var ctx = new TestContext();
+            var ctx = new TestContext(_services);
             ctx.Context.DrawBitmap(bitmap, 1, new Rect(1, 1, 1, 1), new Rect(1, 1, 1, 1));
             var renderData = ctx.Context.GetRenderResults()!;
             Assert.Equal(2, bitmap.RefCount);
@@ -112,7 +117,7 @@ namespace Avalonia.Base.UnitTests.Rendering.SceneGraph
         [Fact]
         public void HitTest_On_Geometry_Node_With_Zero_Transform_Does_Not_Throw()
         {
-            var ctx = new TestContext();
+            var ctx = new TestContext(_services);
             using (ctx.Context.PushTransform(new Matrix()))
                 ctx.Context.DrawGeometry(Brushes.Black, null, Mock.Of<IGeometryImpl>());
             Assert.False(ctx.Context.GetRenderResults()!.HitTest(default));
@@ -121,7 +126,7 @@ namespace Avalonia.Base.UnitTests.Rendering.SceneGraph
         [Fact]
         public void HitTest_RectangleNode_With_Transform_Hits()
         {
-            var ctx = new TestContext();
+            var ctx = new TestContext(_services);
             using (ctx.Context.PushTransform(Matrix.CreateTranslation(20, 20)))
                 ctx.Context.DrawRectangle(Brushes.Black, null, new RoundedRect(new Rect(0, 0, 10, 10)));
 
diff --git a/tests/Avalonia.UnitTests/CompositorTestServices.cs b/tests/Avalonia.UnitTests/CompositorTestServices.cs
index 7850735178..f1d41364e9 100644
--- a/tests/Avalonia.UnitTests/CompositorTestServices.cs
+++ b/tests/Avalonia.UnitTests/CompositorTestServices.cs
@@ -125,7 +125,6 @@ public class CompositorTestServices : IDisposable
         public event Action<TimeSpan> Tick;
         public bool RunsInBackground => false;
         public void TriggerTick() => Tick?.Invoke(TimeSpan.Zero);
-        public Task TriggerBackgroundTick() => Task.Run(TriggerTick);
     }
 
     class TopLevelImpl : ITopLevelImpl
diff --git a/tests/Avalonia.UnitTests/ScopedTestBase.cs b/tests/Avalonia.UnitTests/ScopedTestBase.cs
index 81f4e87032..5104823c7b 100644
--- a/tests/Avalonia.UnitTests/ScopedTestBase.cs
+++ b/tests/Avalonia.UnitTests/ScopedTestBase.cs
@@ -2,9 +2,11 @@ using System;
 using System.Threading;
 using Avalonia.Controls;
 using Avalonia.Threading;
+using Xunit;
 
 namespace Avalonia.UnitTests;
 
+[Collection("Scoped Not Parallel")]
 public class ScopedTestBase : IDisposable
 {
     private readonly IDisposable _scope;

From 86e5481686d9992f166fd00d02441657bb5dc065 Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 May 2023 16:37:34 +0600
Subject: [PATCH 08/12] PR comments

---
 src/Avalonia.Base/Animation/TransitionObservableBase.cs | 2 +-
 src/Avalonia.Base/Layout/Layoutable.cs                  | 9 +++++++++
 src/Avalonia.Controls/TopLevel.cs                       | 9 ---------
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/Avalonia.Base/Animation/TransitionObservableBase.cs b/src/Avalonia.Base/Animation/TransitionObservableBase.cs
index 19d252723d..92462dc537 100644
--- a/src/Avalonia.Base/Animation/TransitionObservableBase.cs
+++ b/src/Avalonia.Base/Animation/TransitionObservableBase.cs
@@ -10,7 +10,7 @@ namespace Avalonia.Animation
     /// Provides base for observables implementing transitions.
     /// </summary>
     /// <typeparam name="T">Type of the transitioned value.</typeparam>
-    public abstract class TransitionObservableBase<T> : SingleSubscriberObservableBase<T>, IObserver<double>
+    internal abstract class TransitionObservableBase<T> : SingleSubscriberObservableBase<T>, IObserver<double>
     {
         private readonly IEasing _easing;
         private readonly IObservable<double> _progress;
diff --git a/src/Avalonia.Base/Layout/Layoutable.cs b/src/Avalonia.Base/Layout/Layoutable.cs
index 08f327d048..f64c26ddf8 100644
--- a/src/Avalonia.Base/Layout/Layoutable.cs
+++ b/src/Avalonia.Base/Layout/Layoutable.cs
@@ -205,6 +205,15 @@ namespace Avalonia.Layout
             }
         }
 
+        /// <summary>
+        /// Executes a layout pass.
+        /// </summary>
+        /// <remarks>
+        /// You should not usually need to call this method explictly, the layout manager will
+        /// schedule layout passes itself.
+        /// </remarks>
+        public void UpdateLayout() => (this.GetVisualRoot() as ILayoutRoot)?.LayoutManager?.ExecuteLayoutPass();
+
         /// <summary>
         /// Gets or sets the width of the element.
         /// </summary>
diff --git a/src/Avalonia.Controls/TopLevel.cs b/src/Avalonia.Controls/TopLevel.cs
index b51222a2fe..9c88fb6844 100644
--- a/src/Avalonia.Controls/TopLevel.cs
+++ b/src/Avalonia.Controls/TopLevel.cs
@@ -374,15 +374,6 @@ namespace Avalonia.Controls
 
         ILayoutManager ILayoutRoot.LayoutManager => LayoutManager;
 
-        /// <summary>
-        /// Executes a layout pass.
-        /// </summary>
-        /// <remarks>
-        /// You should not usually need to call this method explictly, the layout manager will
-        /// schedule layout passes itself.
-        /// </remarks>
-        public void UpdateLayout() => LayoutManager?.ExecuteLayoutPass();
-
         /// <summary>
         /// Gets the platform-specific window implementation.
         /// </summary>

From fa7eb55902490d3de7ae4c663258c8937e76e681 Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 May 2023 16:37:53 +0600
Subject: [PATCH 09/12] Flakiness?

---
 tests/Avalonia.RenderTests/TestBase.cs             |  8 ++------
 tests/Avalonia.UnitTests/CompositorTestServices.cs | 11 ++++++++++-
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/tests/Avalonia.RenderTests/TestBase.cs b/tests/Avalonia.RenderTests/TestBase.cs
index 4e4842e856..3e0ba7d2f6 100644
--- a/tests/Avalonia.RenderTests/TestBase.cs
+++ b/tests/Avalonia.RenderTests/TestBase.cs
@@ -107,7 +107,8 @@ namespace Avalonia.Direct2D1.RenderTests
             
             var timer = new ManualRenderTimer();
 
-            var compositor = new Compositor(new RenderLoop(timer), null, true);
+            var compositor = new Compositor(new RenderLoop(timer), null, true,
+                new DispatcherCompositorScheduler(), true);
             using (var writableBitmap = factory.CreateWriteableBitmap(pixelSize, dpiVector, factory.DefaultPixelFormat, factory.DefaultAlphaFormat))
             {
                 var root = new TestRenderRoot(dpiVector.X / 96, null!);
@@ -121,11 +122,6 @@ namespace Avalonia.Direct2D1.RenderTests
                     Dispatcher.UIThread.RunJobs();
                     timer.TriggerTick();
                 }
-
-                // Free pools
-                for (var c = 0; c < 11; c++)
-                    foreach (var dp in Dispatcher.SnapshotTimersForUnitTests())
-                        dp.ForceFire();
                 writableBitmap.Save(compositedPath);
             }
         }
diff --git a/tests/Avalonia.UnitTests/CompositorTestServices.cs b/tests/Avalonia.UnitTests/CompositorTestServices.cs
index f1d41364e9..5fcfec0437 100644
--- a/tests/Avalonia.UnitTests/CompositorTestServices.cs
+++ b/tests/Avalonia.UnitTests/CompositorTestServices.cs
@@ -45,7 +45,8 @@ public class CompositorTestServices : IDisposable
         {
             AvaloniaLocator.CurrentMutable.Bind<IRenderTimer>().ToConstant(Timer);
 
-            Compositor = new Compositor(new RenderLoop(Timer), null);
+            Compositor = new Compositor(new RenderLoop(Timer), null,
+                true, new DispatcherCompositorScheduler(), true);
             var impl = new TopLevelImpl(Compositor, size ?? new Size(1000, 1000));
             TopLevel = new EmbeddableControlRoot(impl)
             {
@@ -207,4 +208,12 @@ public class NullCompositorScheduler : ICompositorScheduler
     {
         
     }
+}
+
+public class DispatcherCompositorScheduler : ICompositorScheduler
+{
+    public void CommitRequested(Compositor compositor)
+    {
+        Dispatcher.UIThread.Post(() => compositor.Commit(), DispatcherPriority.UiThreadRender);
+    }
 }
\ No newline at end of file

From 797def7d559483207c60f49b334f9c1ad0580d95 Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 May 2023 17:05:51 +0600
Subject: [PATCH 10/12] build

---
 src/Android/Avalonia.Android/AvaloniaView.cs | 4 ++--
 src/iOS/Avalonia.iOS/AvaloniaView.cs         | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/Android/Avalonia.Android/AvaloniaView.cs b/src/Android/Avalonia.Android/AvaloniaView.cs
index 27481a598e..05ec1795f4 100644
--- a/src/Android/Avalonia.Android/AvaloniaView.cs
+++ b/src/Android/Avalonia.Android/AvaloniaView.cs
@@ -67,7 +67,7 @@ namespace Avalonia.Android
                     _timerSubscription = timer.SubscribeView(this);
                 }
 
-                _root.Renderer.Start();
+                _root.StartRendering();
 
                 if (_view.TryGetFeature<IInsetsManager>(out var insetsManager) == true)
                 {
@@ -76,7 +76,7 @@ namespace Avalonia.Android
             }
             else
             {
-                _root.Renderer.Stop();
+                _root.StopRendering();
                 _timerSubscription?.Dispose();
             }
         }
diff --git a/src/iOS/Avalonia.iOS/AvaloniaView.cs b/src/iOS/Avalonia.iOS/AvaloniaView.cs
index 86aac0e456..479fc7f1c2 100644
--- a/src/iOS/Avalonia.iOS/AvaloniaView.cs
+++ b/src/iOS/Avalonia.iOS/AvaloniaView.cs
@@ -38,7 +38,7 @@ namespace Avalonia.iOS
 
             _topLevel.Prepare();
 
-            _topLevel.Renderer.Start();
+            _topLevel.StartRendering();
 
             var l = (CAEAGLLayer)Layer;
             l.ContentsScale = UIScreen.MainScreen.Scale;

From 306c2a58e52483abc3851d0dc3b8aaada9f498e2 Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 May 2023 18:09:48 +0600
Subject: [PATCH 11/12] Cancellation token for Animation.RunAsync

---
 src/Avalonia.Base/Animation/Animation.cs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Base/Animation/Animation.cs b/src/Avalonia.Base/Animation/Animation.cs
index ecf796ac4d..4de89bfe97 100644
--- a/src/Avalonia.Base/Animation/Animation.cs
+++ b/src/Avalonia.Base/Animation/Animation.cs
@@ -359,7 +359,8 @@ namespace Avalonia.Animation
             return new CompositeDisposable(subscriptions);
         }
 
-        public Task RunAsync(Animatable control) => RunAsync(control, null);
+        public Task RunAsync(Animatable control, CancellationToken cancellationToken = default) =>
+            RunAsync(control, null, cancellationToken);
         
         /// <inheritdoc/>
         internal Task RunAsync(Animatable control, IClock? clock)

From d198bad34b641e9270550192555ff3e0b9a4cd94 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@users.noreply.github.com>
Date: Mon, 29 May 2023 14:51:18 +0200
Subject: [PATCH 12/12] Make SingleSubscriberObservableBase internal.

The last public dependency was `TemplateBinding` which can trivially be made to not inherit from it.
---
 src/Avalonia.Base/Data/TemplateBinding.cs     | 37 ++++++++++++++++---
 .../SingleSubscriberObservableBase.cs         |  2 +-
 2 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/src/Avalonia.Base/Data/TemplateBinding.cs b/src/Avalonia.Base/Data/TemplateBinding.cs
index 09f04dfe70..0fd40cd09d 100644
--- a/src/Avalonia.Base/Data/TemplateBinding.cs
+++ b/src/Avalonia.Base/Data/TemplateBinding.cs
@@ -3,18 +3,21 @@ using System.Globalization;
 using Avalonia.Data.Converters;
 using Avalonia.Reactive;
 using Avalonia.Styling;
+using Avalonia.Threading;
 
 namespace Avalonia.Data
 {
     /// <summary>
     /// A XAML binding to a property on a control's templated parent.
     /// </summary>
-    public class TemplateBinding : SingleSubscriberObservableBase<object?>,
+    public class TemplateBinding : IObservable<object?>,
         IBinding,
         IDescription,
         IAvaloniaSubject<object?>,
-        ISetterValue
+        ISetterValue,
+        IDisposable
     {
+        private IObserver<object?>? _observer;
         private bool _isSetterValue;
         private StyledElement? _target;
         private Type? _targetType;
@@ -29,6 +32,28 @@ namespace Avalonia.Data
             Property = property;
         }
 
+        public IDisposable Subscribe(IObserver<object?> observer)
+        {
+            _ = observer ?? throw new ArgumentNullException(nameof(observer));
+            Dispatcher.UIThread.VerifyAccess();
+
+            if (_observer != null)
+            {
+                throw new InvalidOperationException("The observable can only be subscribed once.");
+            }
+
+            _observer = observer;
+            Subscribed();
+
+            return this;
+        }
+
+        public virtual void Dispose()
+        {
+            Unsubscribed();
+            _observer = null;
+        }
+
         /// <inheritdoc/>
         public InstancedBinding? Initiate(
             AvaloniaObject target,
@@ -111,7 +136,7 @@ namespace Avalonia.Data
         /// <inheritdoc/>
         void ISetterValue.Initialize(SetterBase setter) => _isSetterValue = true;
 
-        protected override void Subscribed()
+        private void Subscribed()
         {
             TemplatedParentChanged();
 
@@ -121,7 +146,7 @@ namespace Avalonia.Data
             }
         }
 
-        protected override void Unsubscribed()
+        private void Unsubscribed()
         {
             if (_target?.TemplatedParent is { } templatedParent)
             {
@@ -147,12 +172,12 @@ namespace Avalonia.Data
                     value = Converter.Convert(value, _targetType ?? typeof(object), ConverterParameter, CultureInfo.CurrentCulture);
                 }
 
-                PublishNext(value);
+                _observer?.OnNext(value);
                 _hasProducedValue = true;
             }
             else if (_hasProducedValue)
             {
-                PublishNext(AvaloniaProperty.UnsetValue);
+                _observer?.OnNext(AvaloniaProperty.UnsetValue);
                 _hasProducedValue = false;
             }
         }
diff --git a/src/Avalonia.Base/Reactive/SingleSubscriberObservableBase.cs b/src/Avalonia.Base/Reactive/SingleSubscriberObservableBase.cs
index 53a0b43c63..10d42214c2 100644
--- a/src/Avalonia.Base/Reactive/SingleSubscriberObservableBase.cs
+++ b/src/Avalonia.Base/Reactive/SingleSubscriberObservableBase.cs
@@ -3,7 +3,7 @@ using Avalonia.Threading;
 
 namespace Avalonia.Reactive
 {
-    public abstract class SingleSubscriberObservableBase<T> : IObservable<T>, IDisposable
+    internal abstract class SingleSubscriberObservableBase<T> : IObservable<T>, IDisposable
     {
         private Exception? _error;
         private IObserver<T>? _observer;