Merge pull request #18899 from unoplatform/dev/jela/brush-weak

perf(brush): Don't use reflection to invoke brush updates

build/ci/.azure-devops-wasm-uitests.yml

@@ -42,7 +42,7 @@ jobs:
   - task: CopyFiles@2
     displayName: 'Publish Wasm Site (net9.0)'
     inputs:
-      SourceFolder: $(build.sourcesdirectory)/src/SamplesApp/SamplesApp.Wasm/bin/Release/net9.0/browser-wasm/publish/wwwroot
+      SourceFolder: $(build.sourcesdirectory)/src/SamplesApp/SamplesApp.Wasm/bin/Release/net9.0/publish/wwwroot
       Contents: '**/*.*'
       TargetFolder: $(build.artifactstagingdirectory)/site-net9.0-$(XAML_FLAVOR_BUILD)
       CleanTargetFolder: false

doc/articles/uno-development/Internal-WeakEventHelper.md

@@ -8,7 +8,7 @@ The WeakEventHelper class is an internal method that is designed to provide a
 memory-friendly environment for registering to events internally in Uno.
 
 This class is not exposed to the end-user because its patterns do not fit with the
-original UWP event-based designs of the API.
+original WinUI event-based designs of the API.
 
 ## The RegisterEvent method
 
@@ -17,35 +17,44 @@ that both the source and the target are weak. The source must be kept alive by
 another longer-lived reference, and the target is kept alive by the
 return disposable.
 
-If the returned disposable is collected, the handler will also be
-collected. Conversely, if the provided list is collected
-raising the event will produce nothing.
+If the provided handler is collected, the registration will
+be collected as well. The returned disposable is not tracked, which means that it will
+not remove the registration when collected, unless the provided handler is a lambda. In
+this case, the lambda's lifetime is tied to the returned disposable.
+
+The WeakEventCollection automatically manages its internal registration list using GC events.
 
 Here's a usage example:
 
- private List<WeakEventHelper.GenericEventHandler> _sizeChangedHandlers = new List<WeakEventHelper.GenericEventHandler>();
+ ```csharp
+ private WeakEventHelper.WeakEventCollection? _sizeChangedHandlers;
 
  internal IDisposable RegisterSizeChangedEvent(WindowSizeChangedEventHandler handler)
  {
   return WeakEventHelper.RegisterEvent(
-   _sizeChangedHandlers,
+   _sizeChangedHandlers ??= new(),
    handler,
    (h, s, e) => (h as WindowSizeChangedEventHandler)?.Invoke(s, (WindowSizeChangedEventArgs)e)
   );
  }
 
+ internal void RaiseEvent()
+ {
+    _sizeChangedHandlers?.Invoke(this, new WindowSizeChangedEventArgs());
+ }
+ ```
+
 The RegisterEvent method is intentionally non-generic to avoid the cost related to AOT performance. The
 performance cost is shifted to downcast and upcast checks in the `EventRaiseHandler` handlers.
 
 The returned disposable must be used as follows :
 
- private SerialDisposable _sizeChangedSubscription = new SerialDisposable();
+ ```csharp
+ private IDisposable? _sizeChangedSubscription;
 
  ...
 
- _sizeChangedSubscription.Disposable = null;
+ _sizeChangedSubscription?.Dispose();
 
- if (Owner != null)
- {
-  _sizeChangedSubscription.Disposable = Window.Current.RegisterSizeChangedEvent(OnCurrentWindowSizeChanged);
- }
+ _sizeChangedSubscription = Window.Current.RegisterSizeChangedEvent(OnCurrentWindowSizeChanged);
+ ```

src/SamplesApp/SamplesApp.Wasm/Program.cs

@@ -24,6 +24,7 @@ public static void Main(string[] args)
 #endif
 
 			Microsoft.UI.Xaml.Application.Start(_ => _app = new App());
+
 		}
 	}
 }

src/SamplesApp/SamplesApp.Wasm/SamplesApp.Wasm.csproj

@@ -17,6 +17,9 @@
 		<WasmShellIncludeWindowsCompatibility>false</WasmShellIncludeWindowsCompatibility>
 		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
 
+		<!-- Required for net9 workloads -->
+		<AppendRuntimeIdentifierToOutputPath>false</AppendRuntimeIdentifierToOutputPath>
+
 		<!-- To build with AOT, uncomment these two lines -->
 		<!--<WasmShellEnableEmccProfiling>true</WasmShellEnableEmccProfiling>
 		<WasmShellMonoRuntimeExecutionMode>InterpreterAndAOT</WasmShellMonoRuntimeExecutionMode>-->

src/Uno.UI.RuntimeTests/Tests/Windows_UI/Given_WeakEventHelper.cs

@@ -0,0 +1,237 @@
+#if HAS_UNO
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Text;
+using System.Threading.Tasks;
+using Uno.Buffers;
+using Windows.Graphics.Capture;
+using Windows.UI.Core;
+
+namespace Uno.UI.RuntimeTests.Tests.Windows_UI;
+
+[TestClass]
+public class Given_WeakEventHelper
+{
+	[TestMethod]
+	public void When_Explicit_Dispose()
+	{
+		WeakEventHelper.WeakEventCollection SUT = new();
+
+		var invoked = 0;
+		Action action = () => invoked++;
+
+		var disposable = WeakEventHelper.RegisterEvent(SUT, action, (s, e, a) => (s as Action).Invoke());
+
+		SUT.Invoke(this, null);
+
+		Assert.AreEqual(1, invoked);
+
+		disposable.Dispose();
+
+		// When disposed invoking events won't call the original action
+		// the registration has been disposed.
+		SUT.Invoke(this, null);
+
+		Assert.AreEqual(1, invoked);
+	}
+
+	[TestMethod]
+	public void When_Registration_Collected()
+	{
+		WeakEventHelper.WeakEventCollection SUT = new();
+
+		var invoked = 0;
+		Action action = () => invoked++;
+
+		void Do()
+		{
+			var disposable = WeakEventHelper.RegisterEvent(SUT, action, (s, e, a) => (s as Action).Invoke());
+
+			SUT.Invoke(this, null);
+
+			Assert.AreEqual(1, invoked);
+
+			disposable = null;
+		}
+
+		Do();
+
+		GC.Collect(2);
+		GC.WaitForPendingFinalizers();
+
+		// Even if the disposable is collected, the event should still be invoked
+		// as the disposable does not track the event registration.
+		SUT.Invoke(this, null);
+
+		Assert.AreEqual(2, invoked);
+	}
+
+	[TestMethod]
+	public void When_Target_Collected()
+	{
+		WeakEventHelper.WeakEventCollection SUT = new();
+
+		var invoked = 0;
+		IDisposable disposable = null;
+
+		void Do()
+		{
+			Action action = () => invoked++;
+
+			disposable = WeakEventHelper.RegisterEvent(SUT, action, (s, e, a) => (s as Action).Invoke());
+
+			SUT.Invoke(this, null);
+
+			Assert.AreEqual(1, invoked);
+		}
+
+		Do();
+
+		GC.Collect(2);
+		GC.WaitForPendingFinalizers();
+
+		SUT.Invoke(this, null);
+
+		Assert.AreEqual(2, invoked);
+	}
+
+	[TestMethod]
+	public void When_Many_Targets_Collected()
+	{
+		WeakEventHelper.WeakEventCollection SUT = new();
+
+		var invoked = 0;
+		List<IDisposable> disposable = new();
+
+		void Do()
+		{
+			Action action = () => invoked++;
+
+			disposable.Add(WeakEventHelper.RegisterEvent(SUT, action, (s, e, a) => (s as Action).Invoke()));
+
+			SUT.Invoke(this, null);
+		}
+
+		for (int i = 0; i < 100; i++)
+		{
+			Do();
+		}
+
+		SUT.Invoke(this, null);
+
+		Assert.AreEqual(5150, invoked);
+
+		disposable.Clear();
+
+		GC.Collect(2);
+		GC.WaitForPendingFinalizers();
+
+		// Ensure that everything has been collected.
+		SUT.Invoke(this, null);
+
+		Assert.AreEqual(5150, invoked);
+	}
+
+	[TestMethod]
+	public void When_Collection_Disposed()
+	{
+		WeakEventHelper.WeakEventCollection SUT = new();
+
+		var invoked = 0;
+
+		Action action = () => invoked++;
+
+		var disposable = WeakEventHelper.RegisterEvent(SUT, action, (s, e, a) => (s as Action).Invoke());
+
+		SUT.Invoke(this, null);
+
+		Assert.AreEqual(1, invoked);
+
+		SUT.Dispose();
+	}
+
+	[TestMethod]
+	public async Task When_Collection_Collected()
+	{
+		WeakReference actionRef = null;
+		WeakReference collectionRef = null;
+
+		void Do()
+		{
+			WeakEventHelper.WeakEventCollection SUT = new();
+			collectionRef = new(SUT);
+
+			var invoked = 0;
+
+			Action action = () => invoked++;
+			actionRef = new(actionRef);
+
+			var disposable = WeakEventHelper.RegisterEvent(SUT, action, (s, e, a) => (s as Action).Invoke());
+
+			SUT.Invoke(this, null);
+
+			Assert.AreEqual(1, invoked);
+
+			SUT.Dispose();
+		}
+
+		Do();
+
+		var sw = Stopwatch.StartNew();
+
+		while ((actionRef.IsAlive || collectionRef.IsAlive) && sw.ElapsedMilliseconds < 5000)
+		{
+			await Task.Delay(10);
+			GC.Collect(2);
+			GC.WaitForPendingFinalizers();
+		}
+
+		Assert.IsFalse(actionRef.IsAlive);
+		Assert.IsFalse(collectionRef.IsAlive);
+	}
+
+	[TestMethod]
+	public void When_Empty_Trim_Stops()
+	{
+		TestPlatformProvider trimProvider = new();
+		WeakEventHelper.WeakEventCollection SUT = new(trimProvider);
+
+		var invoked = 0;
+
+		Action action = () => invoked++;
+
+		Assert.IsNull(trimProvider.Invoke());
+
+		var disposable = WeakEventHelper.RegisterEvent(SUT, action, (s, e, a) => (s as Action).Invoke());
+
+		Assert.IsTrue(trimProvider.Invoke());
+
+		SUT.Invoke(this, null);
+
+		Assert.AreEqual(1, invoked);
+
+		disposable.Dispose();
+
+		Assert.IsFalse(trimProvider.Invoke());
+
+		Assert.AreEqual(1, invoked);
+	}
+
+	private class TestPlatformProvider : WeakEventHelper.ITrimProvider
+	{
+		private object _target;
+		private Func<object, bool> _callback;
+
+		public void RegisterTrimCallback(Func<object, bool> callback, object target)
+		{
+			_target = target;
+			_callback = callback;
+		}
+
+		public bool? Invoke() => _callback?.Invoke(_target);
+	}
+}
+#endif