Unittests around memory allocation

Mediator.sln

@@ -72,7 +72,11 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Mediator.SourceGenerator.Im
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Mediator.SourceGenerator.Roslyn40.Tests", "test\Mediator.SourceGenerator.Roslyn40.Tests\Mediator.SourceGenerator.Roslyn40.Tests.csproj", "{E4EE80C5-179C-4483-9E91-3107B3E1CD5A}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Mediator.SmokeTestConsole", "test\Mediator.SmokeTestConsole\Mediator.SmokeTestConsole.csproj", "{65D8C0F8-E4CF-452D-86FB-482FE63C7C89}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Mediator.SmokeTestConsole", "test\Mediator.SmokeTestConsole\Mediator.SmokeTestConsole.csproj", "{65D8C0F8-E4CF-452D-86FB-482FE63C7C89}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Mediator.MemAllocationTests", "test\Mediator.MemAllocationTests\Mediator.MemAllocationTests.csproj", "{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Mediator.Tests.Common", "test\Mediator.Tests.Common\Mediator.Tests.Common.csproj", "{32DC3B96-7E6E-40B0-AA12-40656B2D0381}"
 EndProject
 Global
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@@ -336,6 +340,30 @@ Global
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 		{65D8C0F8-E4CF-452D-86FB-482FE63C7C89}.Release|x86.Build.0 = Release|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Debug|x64.Build.0 = Debug|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Debug|x86.Build.0 = Debug|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Release|Any CPU.Build.0 = Release|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Release|x64.ActiveCfg = Release|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Release|x64.Build.0 = Release|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Release|x86.ActiveCfg = Release|Any CPU
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD}.Release|x86.Build.0 = Release|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Debug|x64.Build.0 = Debug|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Debug|x86.Build.0 = Debug|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Release|Any CPU.Build.0 = Release|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Release|x64.ActiveCfg = Release|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Release|x64.Build.0 = Release|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Release|x86.ActiveCfg = Release|Any CPU
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381}.Release|x86.Build.0 = Release|Any CPU
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 		HideSolutionNode = FALSE
@@ -363,6 +391,8 @@ Global
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 		{65D8C0F8-E4CF-452D-86FB-482FE63C7C89} = {ED1809FC-733B-4D9E-8FEE-70D3BB0BBD84}
+		{EECFACC8-E841-4EF5-A1D7-A64C84B7DBCD} = {ED1809FC-733B-4D9E-8FEE-70D3BB0BBD84}
+		{32DC3B96-7E6E-40B0-AA12-40656B2D0381} = {ED1809FC-733B-4D9E-8FEE-70D3BB0BBD84}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {D45B5457-4190-49B6-BF89-7FA5F4C8ABE2}

test/Mediator.MemAllocationTests/Mediator.MemAllocationTests.csproj

@@ -0,0 +1,39 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+
+    <IsPackable>false</IsPackable>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
+    <!--<ReportAnalyzer>true</ReportAnalyzer>-->
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+    <Using Include="System.Runtime.CompilerServices" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="$(DotNetVersion)" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
+    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="coverlet.collector" Version="3.1.2">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="JetBrains.DotMemoryUnit" Version="3.1.20200127.214830" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Mediator.SourceGenerator.Implementation\Mediator.SourceGenerator.Implementation.csproj" OutputItemType="Analyzer" />
+    <ProjectReference Include="..\..\src\Mediator.SourceGenerator.Roslyn40\Mediator.SourceGenerator.Roslyn40.csproj" OutputItemType="Analyzer" />
+    <ProjectReference Include="..\..\src\Mediator\Mediator.csproj" />
+    <ProjectReference Include="..\Mediator.Tests.Common\Mediator.Tests.Common.csproj" />
+  </ItemGroup>
+
+</Project>

test/Mediator.MemAllocationTests/NonParallelCollectionDefinitionClass.cs

@@ -0,0 +1,6 @@
+namespace Mediator.Tests;
+
+[CollectionDefinition("Non-Parallel", DisableParallelization = true)]
+public class NonParallelCollectionDefinitionClass
+{
+}

test/Mediator.MemAllocationTests/NotificationTests.cs

@@ -0,0 +1,32 @@
+using Mediator.Tests.Common;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Mediator.MemAllocationTests;
+
+[Collection("Non-Parallel")]
+public class NotificationTests
+{
+    [Fact]
+    public void Test_Notification_Handler()
+    {
+        var services = new ServiceCollection();
+
+        services.AddMediator();
+
+        using var sp = services.BuildServiceProvider(validateScopes: true);
+        var mediator = sp.GetRequiredService<IMediator>();
+
+        var id = Guid.NewGuid();
+        var notification = new SomeNotificationMemAllocTracking(id);
+
+        // Ensure everything is cached
+        mediator.Publish(notification); // Everything returns sync
+
+        var beforeBytes = Allocations.GetCurrentThreadAllocatedBytes();
+        mediator.Publish(notification); // Everything returns sync
+        var afterBytes = Allocations.GetCurrentThreadAllocatedBytes();
+
+        // TODO: why 40? benchmarkdotnet reports 0 alloc for this case
+        Assert.Equal(40, afterBytes - beforeBytes);
+    }
+}

test/Mediator.MemAllocationTests/RequestTests.cs

@@ -0,0 +1,94 @@
+using JetBrains.dotMemoryUnit;
+using JetBrains.dotMemoryUnit.Kernel;
+using Mediator.Tests.Common;
+using Microsoft.Extensions.DependencyInjection;
+using Xunit.Abstractions;
+
+namespace Mediator.MemAllocationTests;
+
+[Collection("Non-Parallel")]
+public class RequestTests
+{
+    private readonly ITestOutputHelper _output;
+
+    public RequestTests(ITestOutputHelper output)
+    {
+        _output = output;
+        DotMemoryUnitTestOutput.SetOutputMethod(output.WriteLine);
+    }
+
+    /// <summary>
+    /// To run these tests
+    /// dotMemoryUnit.exe "$((Get-Command dotnet.exe).Path)" -- test "./test/Mediator.MemAllocationTests/"
+    /// TODO: find a way to filter out dotMemoryUnit's own mem allocations from report...
+    /// </summary>
+    /// <returns></returns>
+    [DotMemoryUnit(CollectAllocations = true)]
+    [Fact]
+    public async Task Test_Request_Handler_dotMemory()
+    {
+        if (!dotMemoryApi.IsEnabled)
+            return;
+
+        var services = new ServiceCollection();
+
+        services.AddMediator();
+
+        await using var sp = services.BuildServiceProvider(validateScopes: true);
+        var mediator = sp.GetRequiredService<Mediator>();
+
+        var id = Guid.NewGuid();
+        var request = new SomeRequestMemAllocTracking(id);
+
+        // Ensure everything is cached
+        await mediator.Send(request);
+        GC.Collect();
+        GC.WaitForPendingFinalizers();
+        GC.WaitForFullGCComplete();
+        GC.Collect();
+
+        var checkpoint = dotMemory.Check();
+        var beforeBytes = GC.GetAllocatedBytesForCurrentThread();
+        await mediator.Send(request);
+        var afterBytes = GC.GetAllocatedBytesForCurrentThread();
+
+        Assert.Equal(0, afterBytes - beforeBytes);
+        dotMemory.Check(memory =>
+        {
+            var traffic = memory.GetDifference(checkpoint);
+            var newObjects = traffic.GetNewObjects();
+            foreach (var obj in newObjects.GroupByType())
+                _output.WriteLine($"Allocations for {obj.TypeFullyQualifiedName}: {obj.SizeInBytes} bytes");
+
+            //_output.WriteLine($"Allocated: {traffic.AllocatedMemory.SizeInBytes}");
+            //foreach (var obj in traffic.GroupByType())
+            //    _output.WriteLine($"Allocations for {obj.TypeFullyQualifiedName}: {obj.AllocatedMemoryInfo.SizeInBytes}");
+
+            Assert.Equal(0, traffic.GetNewObjects().ObjectsCount);
+        });
+    }
+
+
+    [Fact]
+    public void Test_Request_Handler()
+    {
+        var services = new ServiceCollection();
+
+        services.AddMediator();
+
+        using var sp = services.BuildServiceProvider(validateScopes: true);
+        var mediator = sp.GetRequiredService<IMediator>();
+
+        var id = Guid.NewGuid();
+        var request = new SomeRequestMemAllocTracking(id);
+
+        // Ensure everything is cached
+        mediator.Send(request); // Everything returns sync
+
+        var beforeBytes = Allocations.GetCurrentThreadAllocatedBytes();
+        mediator.Send(request); // Everything returns sync
+        var afterBytes = Allocations.GetCurrentThreadAllocatedBytes();
+
+        Assert.Equal(0, afterBytes - beforeBytes);
+    }
+}

test/Mediator.MemAllocationTests/SomeNotificationMemAllocTracking.cs

@@ -0,0 +1,8 @@
+namespace Mediator.MemAllocationTests;
+
+public sealed record SomeNotificationMemAllocTracking(Guid Id) : INotification;
+
+public sealed class SomeNotificationMemAllocTrackingHandler : INotificationHandler<SomeNotificationMemAllocTracking>
+{
+    public ValueTask Handle(SomeNotificationMemAllocTracking notification, CancellationToken cancellationToken) => default;
+}

test/Mediator.MemAllocationTests/SomeRequestMemAllocTracking.cs

@@ -0,0 +1,8 @@
+namespace Mediator.MemAllocationTests;
+
+public sealed record SomeRequestMemAllocTracking(Guid Id) : IRequest;
+
+public sealed class SomeRequestMemAllocTrackingHandler : IRequestHandler<SomeRequestMemAllocTracking>
+{
+    public ValueTask<Unit> Handle(SomeRequestMemAllocTracking request, CancellationToken cancellationToken) => default;
+}

test/Mediator.Tests.Common/Fixture.cs

@@ -0,0 +1,22 @@
+namespace Mediator.Tests.Common;
+
+public static class Allocations
+{
+    public static long GetCurrentThreadAllocatedBytes()
+    {
+        // Run before and after message sending to test allocations.
+        // Stolen from https://github.com/dotnet/BenchmarkDotNet/blob/4bd433d85fff4fb6ba8c4f8df3e685ad669e2519/src/BenchmarkDotNet/Engines/GcStats.cs#L132
+        // There is a reason GC.Collect is run first
+        GC.Collect();
+        return GC.GetAllocatedBytesForCurrentThread();
+    }
+
+    public static long GetCurrentAllocatedBytes()
+    {
+        // Run before and after message sending to test allocations.
+        // Stolen from https://github.com/dotnet/BenchmarkDotNet/blob/4bd433d85fff4fb6ba8c4f8df3e685ad669e2519/src/BenchmarkDotNet/Engines/GcStats.cs#L132
+        // There is a reason GC.Collect is run first
+        GC.Collect();
+        return GC.GetTotalAllocatedBytes(true);
+    }
+}

test/Mediator.Tests.Common/Mediator.Tests.Common.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="$(DotNetVersion)" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Mediator\Mediator.csproj" />
+  </ItemGroup>
+
+</Project>

test/Mediator.Tests/Fixture.cs

@@ -49,7 +49,6 @@ public static (IServiceProvider sp, IMediator mediator) GetMediatorCustomContain
         return (sp, mediator!);
     }
 
-
     private sealed class CustomServiceProvider : IServiceProvider
     {
         private readonly IServiceCollection _services;

test/Mediator.Tests/Mediator.Tests.csproj

@@ -32,6 +32,7 @@
     <ProjectReference Include="..\..\src\Mediator.SourceGenerator.Implementation\Mediator.SourceGenerator.Implementation.csproj" OutputItemType="Analyzer" />
     <ProjectReference Include="..\..\src\Mediator.SourceGenerator.Roslyn38\Mediator.SourceGenerator.Roslyn38.csproj" OutputItemType="Analyzer" />
     <ProjectReference Include="..\..\src\Mediator\Mediator.csproj" />
+    <ProjectReference Include="..\Mediator.Tests.Common\Mediator.Tests.Common.csproj" />
   </ItemGroup>
 
 </Project>

test/Mediator.Tests/NonParallelCollectionDefinitionClass.cs

@@ -0,0 +1,6 @@
+namespace Mediator.Tests;
+
+[CollectionDefinition("Non-Parallel", DisableParallelization = true)]
+public class NonParallelCollectionDefinitionClass
+{
+}