Updated benchmarks

- Update BenchmarkDotNet
- Added measure benchmark
- Add memory diagnoser

tests/Avalonia.Benchmarks/Avalonia.Benchmarks.csproj

@@ -49,6 +49,7 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Layout\Measure.cs" />
     <Compile Include="Styling\ApplyStyling.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
@@ -100,7 +101,7 @@
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <ItemGroup>
-    <PackageReference Include="BenchmarkDotNet" Version="0.9.2" />
+    <PackageReference Include="BenchmarkDotNet" Version="0.10.8" />
   </ItemGroup>
   <Import Project="$(MSBuildThisFileDirectory)..\..\src\Shared\nuget.workaround.targets" />
 </Project>

tests/Avalonia.Benchmarks/Layout/Measure.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using Avalonia.Controls;
+using Avalonia.Layout;
+using Avalonia.UnitTests;
+using BenchmarkDotNet.Attributes;
+
+namespace Avalonia.Benchmarks.Layout
+{
+    [MemoryDiagnoser]
+    public class Measure : IDisposable
+    {
+        private IDisposable _app;
+        private TestRoot root;
+        private List<Control> controls = new List<Control>();
+
+        public Measure()
+        {
+            _app = UnitTestApplication.Start(TestServices.RealLayoutManager);
+
+            var panel = new StackPanel();
+            root = new TestRoot { Child = panel };
+            controls.Add(panel);
+            CreateChildren(panel, 3, 5);
+            LayoutManager.Instance.ExecuteInitialLayoutPass(root);
+        }
+
+        public void Dispose()
+        {
+            _app.Dispose();
+        }
+
+        [Benchmark]
+        public void Remeasure_Half()
+        {
+            var random = new Random(1);
+
+            foreach (var control in controls)
+            {
+                if (random.Next(2) == 0)
+                {
+                    control.InvalidateMeasure();
+                }
+            }
+
+            LayoutManager.Instance.ExecuteLayoutPass();
+        }
+
+        private void CreateChildren(IPanel parent, int childCount, int iterations)
+        {
+            for (var i = 0; i < childCount; ++i)
+            {
+                var control = new StackPanel();
+                parent.Children.Add(control);
+
+                if (iterations > 0)
+                {
+                    CreateChildren(control, childCount, iterations - 1);
+                }
+
+                controls.Add(control);
+            }
+        }
+    }
+}

tests/Avalonia.Benchmarks/Styling/ApplyStyling.cs

@@ -11,6 +11,7 @@ using Avalonia.VisualTree;
 
 namespace Avalonia.Benchmarks.Styling
 {
+    [MemoryDiagnoser]
     public class ApplyStyling : IDisposable
     {
         private IDisposable _app;