Rework ProjectSnapshotManagerDispatcher to avoid creating a dedicated thread

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorCSharpFormattingBenchmark.cs

@@ -61,7 +61,7 @@ public async Task InitializeRazorCSharpFormattingAsync()
         var targetPath = "/Components/Pages/Generated.razor";
 
         DocumentUri = new Uri(_filePath);
-        DocumentSnapshot = GetDocumentSnapshot(projectFilePath, _filePath, targetPath);
+        DocumentSnapshot = await GetDocumentSnapshotAsync(projectFilePath, _filePath, targetPath);
         DocumentText = await DocumentSnapshot.GetTextAsync();
     }
 

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorCodeActionsBenchmark.cs

@@ -75,7 +75,7 @@ public async Task SetupAsync()
         var targetPath = "/Components/Pages/Generated.razor";
 
         DocumentUri = new Uri(_filePath);
-        DocumentSnapshot = GetDocumentSnapshot(projectFilePath, _filePath, targetPath);
+        DocumentSnapshot = await GetDocumentSnapshotAsync(projectFilePath, _filePath, targetPath);
         DocumentText = await DocumentSnapshot.GetTextAsync();
 
         RazorCodeActionRange = ToRange(razorCodeActionIndex);

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorCompletionBenchmark.cs

@@ -74,7 +74,7 @@ public async Task SetupAsync()
         var targetPath = "/Components/Pages/Generated.razor";
 
         DocumentUri = new Uri(_filePath);
-        DocumentSnapshot = GetDocumentSnapshot(projectFilePath, _filePath, targetPath);
+        DocumentSnapshot = await GetDocumentSnapshotAsync(projectFilePath, _filePath, targetPath);
         DocumentText = await DocumentSnapshot.GetTextAsync();
 
         RazorPosition = ToPosition(razorCodeActionIndex);

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorDocumentMappingBenchmark.cs

@@ -48,7 +48,7 @@ public async Task InitializeRazorCSharpFormattingAsync()
 
         var targetPath = "/Components/Pages/Generated.razor";
 
-        DocumentSnapshot = GetDocumentSnapshot(projectFilePath, _filePath, targetPath);
+        DocumentSnapshot = await GetDocumentSnapshotAsync(projectFilePath, _filePath, targetPath);
 
         var codeDocument = await DocumentSnapshot.GetGeneratedOutputAsync();
         CSharpDocument = codeDocument.GetCSharpDocument();

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorLanguageServerBenchmarkBase.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
 #nullable disable
@@ -52,7 +52,7 @@ private protected virtual LanguageServerFeatureOptions BuildFeatureOptions()
 
     private protected NoopLogger Logger { get; }
 
-    internal IDocumentSnapshot GetDocumentSnapshot(string projectFilePath, string filePath, string targetPath)
+    internal async Task<IDocumentSnapshot> GetDocumentSnapshotAsync(string projectFilePath, string filePath, string targetPath)
     {
         var intermediateOutputPath = Path.Combine(Path.GetDirectoryName(projectFilePath), "obj");
         var hostProject = new HostProject(projectFilePath, intermediateOutputPath, RazorConfiguration.Default, rootNamespace: null);
@@ -61,16 +61,22 @@ internal IDocumentSnapshot GetDocumentSnapshot(string projectFilePath, string fi
         var textLoader = TextLoader.From(TextAndVersion.Create(text, VersionStamp.Create()));
         var hostDocument = new HostDocument(filePath, targetPath, FileKinds.Component);
 
-        var projectSnapshotManager = CreateProjectSnapshotManager();
-        projectSnapshotManager.ProjectAdded(hostProject);
-        var tagHelpers = CommonResources.LegacyTagHelpers;
-        var projectWorkspaceState = ProjectWorkspaceState.Create(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.CSharp11);
-        projectSnapshotManager.ProjectWorkspaceStateChanged(hostProject.Key, projectWorkspaceState);
-        projectSnapshotManager.DocumentAdded(hostProject.Key, hostDocument, textLoader);
-        var projectSnapshot = projectSnapshotManager.GetLoadedProject(hostProject.Key);
+        var projectManager = CreateProjectSnapshotManager();
 
-        var documentSnapshot = projectSnapshot.GetDocument(filePath);
-        return documentSnapshot;
+        await Dispatcher.RunAsync(
+            () =>
+            {
+                projectManager.ProjectAdded(hostProject);
+                var tagHelpers = CommonResources.LegacyTagHelpers;
+                var projectWorkspaceState = ProjectWorkspaceState.Create(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.CSharp11);
+                projectManager.ProjectWorkspaceStateChanged(hostProject.Key, projectWorkspaceState);
+                projectManager.DocumentAdded(hostProject.Key, hostDocument, textLoader);
+            },
+            CancellationToken.None);
+
+        var projectSnapshot = projectManager.GetLoadedProject(hostProject.Key);
+
+        return projectSnapshot.GetDocument(filePath);
     }
 
     private class NoopClientNotifierService : IClientConnection, IOnInitialized

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorSemanticTokensBenchmark.cs

@@ -61,7 +61,7 @@ public async Task InitializeRazorSemanticAsync()
         TargetPath = $"/Components/Pages/{fileName}.razor";
 
         var documentUri = new Uri(filePath);
-        var documentSnapshot = GetDocumentSnapshot(ProjectFilePath, filePath, TargetPath);
+        var documentSnapshot = await GetDocumentSnapshotAsync(ProjectFilePath, filePath, TargetPath);
         var version = 1;
         DocumentContext = new VersionedDocumentContext(documentUri, documentSnapshot, projectContext: null, version);
 
@@ -100,7 +100,7 @@ await RazorSemanticTokenService.GetSemanticTokensAsync(
 
     private async Task UpdateDocumentAsync(int newVersion, IDocumentSnapshot documentSnapshot, CancellationToken cancellationToken)
     {
-        await ProjectSnapshotManagerDispatcher.RunOnDispatcherThreadAsync(
+        await ProjectSnapshotManagerDispatcher.RunAsync(
             () => VersionCache.TrackDocumentVersion(documentSnapshot, newVersion), cancellationToken).ConfigureAwait(false);
     }
 

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorSemanticTokensRangeEndpointBenchmark.cs

@@ -70,7 +70,7 @@ public async Task InitializeRazorSemanticAsync()
         TargetPath = "/Components/Pages/SemanticTokens.razor";
 
         var documentUri = new Uri(filePath);
-        var documentSnapshot = GetDocumentSnapshot(ProjectFilePath, filePath, TargetPath);
+        var documentSnapshot = await GetDocumentSnapshotAsync(ProjectFilePath, filePath, TargetPath);
         var version = 1;
         DocumentContext = new VersionedDocumentContext(documentUri, documentSnapshot, projectContext: null, version);
 
@@ -125,7 +125,7 @@ public async Task RazorSemanticTokensRangeEndpointRangesAsync()
     private async Task UpdateDocumentAsync(int newVersion, IDocumentSnapshot documentSnapshot,
         CancellationToken cancellationToken)
     {
-        await ProjectSnapshotManagerDispatcher.RunOnDispatcherThreadAsync(
+        await ProjectSnapshotManagerDispatcher.RunAsync(
                 () => VersionCache.TrackDocumentVersion(documentSnapshot, newVersion), cancellationToken)
             .ConfigureAwait(false);
     }

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorSemanticTokensScrollingBenchmark.cs

@@ -52,7 +52,7 @@ public async Task InitializeRazorSemanticAsync()
         TargetPath = "/Components/Pages/FormattingTest.razor";
 
         var documentUri = new Uri(filePath);
-        var documentSnapshot = GetDocumentSnapshot(ProjectFilePath, filePath, TargetPath);
+        var documentSnapshot = await GetDocumentSnapshotAsync(ProjectFilePath, filePath, TargetPath);
         DocumentContext = new VersionedDocumentContext(documentUri, documentSnapshot, projectContext: null, version: 1);
 
         var text = await DocumentSnapshot.GetTextAsync().ConfigureAwait(false);
@@ -112,7 +112,7 @@ public async Task RazorSemanticTokensRangeScrollingAsync()
 
     private async Task UpdateDocumentAsync(int newVersion, IDocumentSnapshot documentSnapshot)
     {
-        await ProjectSnapshotManagerDispatcher!.RunOnDispatcherThreadAsync(
+        await ProjectSnapshotManagerDispatcher!.RunAsync(
             () => VersionCache!.TrackDocumentVersion(documentSnapshot, newVersion), CancellationToken.None).ConfigureAwait(false);
     }
 

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/ProjectSystem/BackgroundCodeGenerationBenchmark.cs

@@ -4,6 +4,7 @@
 #nullable disable
 
 using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
 using BenchmarkDotNet.Attributes;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
@@ -13,40 +14,49 @@ namespace Microsoft.AspNetCore.Razor.Microbenchmarks;
 public class BackgroundCodeGenerationBenchmark : ProjectSnapshotManagerBenchmarkBase
 {
     [IterationSetup]
-    public void Setup()
+    public async Task SetupAsync()
     {
-        SnapshotManager = CreateProjectSnapshotManager();
-        SnapshotManager.ProjectAdded(HostProject);
-        SnapshotManager.Changed += SnapshotManager_Changed;
+        ProjectManager = CreateProjectSnapshotManager();
+
+        await Dispatcher.RunAsync(
+            () => ProjectManager.ProjectAdded(HostProject),
+            CancellationToken.None);
+
+        ProjectManager.Changed += SnapshotManager_Changed;
     }
 
     [IterationCleanup]
     public void Cleanup()
     {
-        SnapshotManager.Changed -= SnapshotManager_Changed;
+        ProjectManager.Changed -= SnapshotManager_Changed;
 
         Tasks.Clear();
     }
 
     private List<Task> Tasks { get; } = new List<Task>();
 
-    private DefaultProjectSnapshotManager SnapshotManager { get; set; }
+    private DefaultProjectSnapshotManager ProjectManager { get; set; }
 
     [Benchmark(Description = "Generates the code for 100 files", OperationsPerInvoke = 100)]
     public async Task BackgroundCodeGeneration_Generate100FilesAsync()
     {
-        for (var i = 0; i < Documents.Length; i++)
-        {
-            SnapshotManager.DocumentAdded(HostProject.Key, Documents[i], TextLoaders[i % 4]);
-        }
+        await Dispatcher.RunAsync(
+            () =>
+            {
+                for (var i = 0; i < Documents.Length; i++)
+                {
+                    ProjectManager.DocumentAdded(HostProject.Key, Documents[i], TextLoaders[i % 4]);
+                }
+            },
+            CancellationToken.None);
 
         await Task.WhenAll(Tasks);
     }
 
     private void SnapshotManager_Changed(object sender, ProjectChangeEventArgs e)
     {
         // The real work happens here.
-        var project = SnapshotManager.GetLoadedProject(e.ProjectKey);
+        var project = ProjectManager.GetLoadedProject(e.ProjectKey);
         var document = project.GetDocument(e.DocumentFilePath);
 
         Tasks.Add(document.GetGeneratedOutputAsync());

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/ProjectSystem/ProjectLoadBenchmark.cs

@@ -3,6 +3,8 @@
 
 #nullable disable
 
+using System.Threading;
+using System.Threading.Tasks;
 using BenchmarkDotNet.Attributes;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
 
@@ -13,19 +15,24 @@ public class ProjectLoadBenchmark : ProjectSnapshotManagerBenchmarkBase
     [IterationSetup]
     public void Setup()
     {
-        SnapshotManager = CreateProjectSnapshotManager();
+        ProjectManager = CreateProjectSnapshotManager();
     }
 
-    private DefaultProjectSnapshotManager SnapshotManager { get; set; }
+    private DefaultProjectSnapshotManager ProjectManager { get; set; }
 
     [Benchmark(Description = "Initializes a project and 100 files", OperationsPerInvoke = 100)]
-    public void ProjectLoad_AddProjectAnd100Files()
+    public async Task ProjectLoad_AddProjectAnd100Files()
     {
-        SnapshotManager.ProjectAdded(HostProject);
+        await Dispatcher.RunAsync(
+            () =>
+            {
+                ProjectManager.ProjectAdded(HostProject);
 
-        for (var i = 0; i < Documents.Length; i++)
-        {
-            SnapshotManager.DocumentAdded(HostProject.Key, Documents[i], TextLoaders[i % 4]);
-        }
+                for (var i = 0; i < Documents.Length; i++)
+                {
+                    ProjectManager.DocumentAdded(HostProject.Key, Documents[i], TextLoaders[i % 4]);
+                }
+            },
+            CancellationToken.None);
     }
 }

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/ProjectSystem/ProjectMutationBenchmark.cs

@@ -3,24 +3,18 @@
 
 #nullable disable
 
-using System;
 using System.Threading;
 using System.Threading.Tasks;
 using BenchmarkDotNet.Attributes;
-using Microsoft.CodeAnalysis.Razor;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
-using Microsoft.CodeAnalysis.Razor.Workspaces;
 
 namespace Microsoft.AspNetCore.Razor.Microbenchmarks;
 
 public class ProjectMutationBenchmark : ProjectSnapshotManagerBenchmarkBase
 {
-    private readonly ProjectSnapshotManagerDispatcher _dispatcher;
-
     public ProjectMutationBenchmark()
         : base(100000)
     {
-        _dispatcher = new SnapshotDispatcher(nameof(ProjectMutationBenchmark));
     }
 
     private Thread _addRemoveThread;
@@ -29,17 +23,17 @@ public ProjectMutationBenchmark()
     [IterationSetup]
     public void Setup()
     {
-        SnapshotManager = CreateProjectSnapshotManager();
+        ProjectManager = CreateProjectSnapshotManager();
     }
 
-    private DefaultProjectSnapshotManager SnapshotManager { get; set; }
+    private DefaultProjectSnapshotManager ProjectManager { get; set; }
 
     [Benchmark(Description = "Does thread contention add/remove of documents", OperationsPerInvoke = 100)]
     public async Task ProjectMutation_Mutates100kFilesAsync()
     {
-        await _dispatcher.RunOnDispatcherThreadAsync(() =>
+        await Dispatcher.RunAsync(() =>
         {
-            SnapshotManager.ProjectAdded(HostProject);
+            ProjectManager.ProjectAdded(HostProject);
         }, CancellationToken.None);
 
         var cancellationSource = new CancellationTokenSource();
@@ -51,9 +45,9 @@ await _dispatcher.RunOnDispatcherThreadAsync(() =>
             for (var i = 0; i < Documents.Length; i++)
             {
                 var document = Documents[i];
-                await _dispatcher.RunOnDispatcherThreadAsync(() => SnapshotManager.DocumentAdded(HostProject.Key, document, TextLoaders[i % 4]), CancellationToken.None).ConfigureAwait(false);
+                await Dispatcher.RunAsync(() => ProjectManager.DocumentAdded(HostProject.Key, document, TextLoaders[i % 4]), CancellationToken.None).ConfigureAwait(false);
                 Thread.Sleep(0);
-                await _dispatcher.RunOnDispatcherThreadAsync(() => SnapshotManager.DocumentRemoved(HostProject.Key, document), CancellationToken.None).ConfigureAwait(false);
+                await Dispatcher.RunAsync(() => ProjectManager.DocumentRemoved(HostProject.Key, document), CancellationToken.None).ConfigureAwait(false);
                 Thread.Sleep(0);
             }
 
@@ -70,9 +64,9 @@ await _dispatcher.RunOnDispatcherThreadAsync(() =>
                     return;
                 }
 
-                await _dispatcher.RunOnDispatcherThreadAsync(() => SnapshotManager.GetProjects(), CancellationToken.None).ConfigureAwait(false);
+                await Dispatcher.RunAsync(() => ProjectManager.GetProjects(), CancellationToken.None).ConfigureAwait(false);
                 Thread.Sleep(0);
-                await _dispatcher.RunOnDispatcherThreadAsync(() => SnapshotManager.GetOpenDocuments(), CancellationToken.None).ConfigureAwait(false);
+                await Dispatcher.RunAsync(() => ProjectManager.GetOpenDocuments(), CancellationToken.None).ConfigureAwait(false);
                 Thread.Sleep(0);
             }
         });
@@ -86,16 +80,4 @@ await _dispatcher.RunOnDispatcherThreadAsync(() =>
             Thread.Sleep(0);
         }
     }
-
-    private class SnapshotDispatcher : ProjectSnapshotManagerDispatcherBase
-    {
-        public SnapshotDispatcher(string threadName) : base(threadName)
-        {
-        }
-
-        public override void LogException(Exception ex)
-        {
-            Console.Error.WriteLine(ex.ToString());
-        }
-    }
 }