From 060698a52f3e0847861b1516612c6058a436bef5 Mon Sep 17 00:00:00 2001
From: Ryan Nowak <nowakra@gmail.com>
Date: Thu, 13 Sep 2018 18:30:37 -0700
Subject: [PATCH] Update to use non-capturing timer

---
 build/dependencies.props                      |  1 +
 .../BackgroundDocumentGenerator.cs            | 22 +++---------------
 ...osoft.CodeAnalysis.Razor.Workspaces.csproj |  1 +
 .../DefaultVisualStudioRazorParser.cs         | 23 +++----------------
 4 files changed, 8 insertions(+), 39 deletions(-)

diff --git a/build/dependencies.props b/build/dependencies.props
index 3d59a7a667..1bc3096ec5 100644
--- a/build/dependencies.props
+++ b/build/dependencies.props
@@ -17,6 +17,7 @@
     <MicrosoftExtensionsCopyOnWriteDictionarySourcesPackageVersion>2.2.0-preview3-35252</MicrosoftExtensionsCopyOnWriteDictionarySourcesPackageVersion>
     <MicrosoftExtensionsDependencyModelPackageVersion>2.1.0</MicrosoftExtensionsDependencyModelPackageVersion>
     <MicrosoftExtensionsHashCodeCombinerSourcesPackageVersion>2.2.0-preview3-35252</MicrosoftExtensionsHashCodeCombinerSourcesPackageVersion>
+    <MicrosoftExtensionsNonCapturingTimerSourcesPackageVersion>2.2.0-preview3-35252</MicrosoftExtensionsNonCapturingTimerSourcesPackageVersion>
     <MicrosoftExtensionsWebEncodersPackageVersion>2.2.0-preview3-35252</MicrosoftExtensionsWebEncodersPackageVersion>
     <MicrosoftNETCoreApp20PackageVersion>2.0.9</MicrosoftNETCoreApp20PackageVersion>
     <MicrosoftNETCoreApp21PackageVersion>2.1.3</MicrosoftNETCoreApp21PackageVersion>
diff --git a/src/Microsoft.CodeAnalysis.Razor.Workspaces/DocumentGenerator/BackgroundDocumentGenerator.cs b/src/Microsoft.CodeAnalysis.Razor.Workspaces/DocumentGenerator/BackgroundDocumentGenerator.cs
index 2ddde78e98..eba3c12e25 100644
--- a/src/Microsoft.CodeAnalysis.Razor.Workspaces/DocumentGenerator/BackgroundDocumentGenerator.cs
+++ b/src/Microsoft.CodeAnalysis.Razor.Workspaces/DocumentGenerator/BackgroundDocumentGenerator.cs
@@ -8,6 +8,7 @@ using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.CodeAnalysis.Razor
 {
@@ -149,26 +150,9 @@ namespace Microsoft.CodeAnalysis.Razor
             // Access to the timer is protected by the lock in Enqueue and in Timer_Tick
             if (_timer == null)
             {
-                // Don't capture asynclocals onto Timer
-                bool restoreFlow = false;
-                try
-                {
-                    if (!ExecutionContext.IsFlowSuppressed())
-                    {
-                        ExecutionContext.SuppressFlow();
-                        restoreFlow = true;
-                    }
 
-                    // Timer will fire after a fixed delay, but only once.
-                    _timer = new Timer(state => ((BackgroundDocumentGenerator)state).Timer_Tick(), this, Delay, Timeout.InfiniteTimeSpan);
-                }
-                finally
-                {
-                    if (restoreFlow)
-                    {
-                        ExecutionContext.RestoreFlow();
-                    }
-                }
+                // Timer will fire after a fixed delay, but only once.
+                _timer = NonCapturingTimer.Create(state => ((BackgroundDocumentGenerator)state).Timer_Tick(), this, Delay, Timeout.InfiniteTimeSpan);
             }
         }
 
diff --git a/src/Microsoft.CodeAnalysis.Razor.Workspaces/Microsoft.CodeAnalysis.Razor.Workspaces.csproj b/src/Microsoft.CodeAnalysis.Razor.Workspaces/Microsoft.CodeAnalysis.Razor.Workspaces.csproj
index e7f29a2fb0..ca09c13e78 100644
--- a/src/Microsoft.CodeAnalysis.Razor.Workspaces/Microsoft.CodeAnalysis.Razor.Workspaces.csproj
+++ b/src/Microsoft.CodeAnalysis.Razor.Workspaces/Microsoft.CodeAnalysis.Razor.Workspaces.csproj
@@ -13,6 +13,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="$(VSIX_MicrosoftCodeAnalysisCSharpPackageVersion)" />
     <PackageReference Include="Microsoft.CodeAnalysis.Workspaces.Common" Version="$(VSIX_MicrosoftCodeAnalysisWorkspacesCommonPackageVersion)" />
+    <PackageReference Include="Microsoft.Extensions.NonCapturingTimer.Sources" Version="$(MicrosoftExtensionsNonCapturingTimerSourcesPackageVersion)" PrivateAssets="all" />
   </ItemGroup>
 
 </Project>
diff --git a/src/Microsoft.VisualStudio.Editor.Razor/DefaultVisualStudioRazorParser.cs b/src/Microsoft.VisualStudio.Editor.Razor/DefaultVisualStudioRazorParser.cs
index 601dba2fc2..25d446febf 100644
--- a/src/Microsoft.VisualStudio.Editor.Razor/DefaultVisualStudioRazorParser.cs
+++ b/src/Microsoft.VisualStudio.Editor.Razor/DefaultVisualStudioRazorParser.cs
@@ -11,6 +11,7 @@ using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.Language.Legacy;
 using Microsoft.CodeAnalysis.Razor;
 using Microsoft.CodeAnalysis.Razor.Editor;
+using Microsoft.Extensions.Internal;
 using Microsoft.VisualStudio.Text;
 using static Microsoft.VisualStudio.Editor.Razor.BackgroundParser;
 using ITextBuffer = Microsoft.VisualStudio.Text.ITextBuffer;
@@ -213,26 +214,8 @@ namespace Microsoft.VisualStudio.Editor.Razor
             {
                 if (_idleTimer == null)
                 {
-                    // Don't capture asynclocals onto Timer
-                    bool restoreFlow = false;
-                    try
-                    {
-                        if (!ExecutionContext.IsFlowSuppressed())
-                        {
-                            ExecutionContext.SuppressFlow();
-                            restoreFlow = true;
-                        }
-
-                        // Timer will fire after a fixed delay, but only once.
-                        _idleTimer = new Timer(state => ((DefaultVisualStudioRazorParser)state).Timer_Tick(), this, IdleDelay, Timeout.InfiniteTimeSpan);
-                    }
-                    finally
-                    {
-                        if (restoreFlow)
-                        {
-                            ExecutionContext.RestoreFlow();
-                        }
-                    }
+                    // Timer will fire after a fixed delay, but only once.
+                    _idleTimer = NonCapturingTimer.Create(state => ((DefaultVisualStudioRazorParser)state).Timer_Tick(), this, IdleDelay, Timeout.InfiniteTimeSpan);
                 }
             }
         }