Use TaskCache class from Microsoft.Extensions.TaskCache.Sources (#1089)

Instead of Task.FromResult(0)

src/Microsoft.AspNetCore.Server.Kestrel.Https/Internal/ClosedStream.cs

@@ -5,6 +5,7 @@ using System;
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Https.Internal
 {
@@ -55,7 +56,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Https.Internal
 
         public override Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
-            return Task.FromResult(0);
+            return TaskCache<int>.DefaultCompletedTask;
         }
 
         public override void Write(byte[] buffer, int offset, int count)

src/Microsoft.AspNetCore.Server.Kestrel.Https/Properties/AssemblyInfo.cs

@@ -3,9 +3,7 @@
 
 using System.Reflection;
 using System.Resources;
-using System.Runtime.CompilerServices;
 
-[assembly: InternalsVisibleTo("Microsoft.AspNetCore.Server.KestrelTests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100f33a29044fa9d740c9b3213a93e57c84b472c84e0b8a0e1ae48e67a9f8f6de9d5f7f3d52ac23e48ac51801f1dc950abe901da34d2a9e3baadb141a17c77ef3c565dd5ee5054b91cf63bb3c6ab83f72ab3aafe93d0fc3c2348b764fafb0b1c0733de51459aeab46580384bf9d74c4e28164b7cde247f891ba07891c9d872ad2bb")]
 [assembly: AssemblyMetadata("Serviceable", "True")]
 [assembly: NeutralResourcesLanguage("en-us")]
 [assembly: AssemblyCompany("Microsoft Corporation.")]

src/Microsoft.AspNetCore.Server.Kestrel.Https/project.json

@@ -19,7 +19,11 @@
     ]
   },
   "dependencies": {
-    "Microsoft.AspNetCore.Server.Kestrel": "1.1.0-*"
+    "Microsoft.AspNetCore.Server.Kestrel": "1.1.0-*",
+    "Microsoft.Extensions.TaskCache.Sources": {
+      "version": "1.1.0-*",
+      "type": "build"
+    }
   },
   "frameworks": {
     "net451": {},

src/Microsoft.AspNetCore.Server.Kestrel/Filter/Internal/LibuvStream.cs

@@ -6,18 +6,16 @@ using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Http;
-using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Filter.Internal
 {
     public class LibuvStream : Stream
     {
-        private readonly static Task<int> _initialCachedTask = Task.FromResult(0);
-
         private readonly SocketInput _input;
         private readonly ISocketOutput _output;
 
-        private Task<int> _cachedTask = _initialCachedTask;
+        private Task<int> _cachedTask = TaskCache<int>.DefaultCompletedTask;
 
         public LibuvStream(SocketInput input, ISocketOutput output)
         {
@@ -125,7 +123,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Filter.Internal
         public override Task FlushAsync(CancellationToken cancellationToken)
         {
             // No-op since writes are immediate.
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         private ValueTask<int> ReadAsync(ArraySegment<byte> buffer)

src/Microsoft.AspNetCore.Server.Kestrel/Filter/NoOpConnectionFilter.cs

@@ -2,7 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Filter
 {
@@ -10,7 +10,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Filter
     {
         public Task OnConnectionAsync(ConnectionFilterContext context)
         {
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/Frame.cs

@@ -12,6 +12,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
+using Microsoft.Extensions.Internal;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Primitives;
 
@@ -338,7 +339,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
             {
                 _requestProcessingStopping = true;
             }
-            return _requestProcessingTask ?? TaskUtilities.CompletedTask;
+            return _requestProcessingTask ?? TaskCache.CompletedTask;
         }
 
         /// <summary>
@@ -500,7 +501,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
             {
                 if (data.Count == 0)
                 {
-                    return TaskUtilities.CompletedTask;
+                    return TaskCache.CompletedTask;
                 }
                 return WriteChunkedAsync(data, cancellationToken);
             }
@@ -569,7 +570,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
         {
             if (HasResponseStarted)
             {
-                return TaskUtilities.CompletedTask;
+                return TaskCache.CompletedTask;
             }
 
             if (_onStarting != null)
@@ -583,7 +584,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
             }
 
             ProduceStart(appCompleted: false);
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         private async Task ProduceStartAndFireOnStartingAwaited()
@@ -624,7 +625,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
                 return ProduceEnd();
             }
 
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         protected Task ProduceEnd()
@@ -635,7 +636,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
                 {
                     // We can no longer change the response, so we simply close the connection.
                     _requestProcessingStopping = true;
-                    return TaskUtilities.CompletedTask;
+                    return TaskCache.CompletedTask;
                 }
 
                 if (_requestRejected)
@@ -697,7 +698,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
                 ConnectionControl.End(ProduceEndType.ConnectionKeepAlive);
             }
 
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         private async Task WriteAutoChunkSuffixAwaited()

src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/FrameRequestStream.cs

@@ -6,6 +6,7 @@ using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
 {
@@ -54,7 +55,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
         public override Task FlushAsync(CancellationToken cancellationToken)
         {
             // No-op.
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         public override long Seek(long offset, SeekOrigin origin)

src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/MessageBody.cs

@@ -5,7 +5,7 @@ using System;
 using System.Numerics;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
 {
@@ -60,7 +60,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
                 else if (result.Result == 0)
                 {
                     // Completed Task, end of stream
-                    return TaskUtilities.CompletedTask;
+                    return TaskCache.CompletedTask;
                 }
 
             } while (true);

src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/SocketOutput.cs

@@ -8,6 +8,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Networking;
+using Microsoft.Extensions.Internal;
 using Microsoft.Extensions.Logging;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
@@ -98,7 +99,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
                 {
                     _log.ConnectionDisconnectedWrite(_connectionId, buffer.Count, _lastWriteError);
 
-                    return TaskUtilities.CompletedTask;
+                    return TaskCache.CompletedTask;
                 }
 
                 if (buffer.Count > 0)
@@ -106,7 +107,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
                     var tail = ProducingStart();
                     if (tail.IsDefault)
                     {
-                        return TaskUtilities.CompletedTask;
+                        return TaskCache.CompletedTask;
                     }
 
                     if (chunk)
@@ -201,7 +202,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
             }
 
             // Return TaskCompletionSource's Task if set, otherwise completed Task 
-            return tcs?.Task ?? TaskUtilities.CompletedTask;
+            return tcs?.Task ?? TaskCache.CompletedTask;
         }
 
         public void End(ProduceEndType endType)
@@ -523,7 +524,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
             }
             else if (_cancelled)
             {
-                return TaskUtilities.CompletedTask;
+                return TaskCache.CompletedTask;
             }
 
             return WriteAsync(buffer, cancellationToken, chunk);

src/Microsoft.AspNetCore.Server.Kestrel/Internal/Infrastructure/TaskUtilities.cs

@@ -9,13 +9,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure
 {
     public static class TaskUtilities
     {
-#if NETSTANDARD1_3
-        public static Task CompletedTask = Task.CompletedTask;
-#else
-        public static Task CompletedTask = Task.FromResult<object>(null);
-#endif
-        public static Task<int> ZeroTask = Task.FromResult(0);
-
         public static Task GetCancelledTask(CancellationToken cancellationToken)
         {
 #if NETSTANDARD1_3

src/Microsoft.AspNetCore.Server.Kestrel/project.json

@@ -18,7 +18,11 @@
     "System.Threading.Tasks.Extensions": "4.0.0-*",
     "Libuv": "1.9.0-*",
     "Microsoft.AspNetCore.Hosting": "1.1.0-*",
-    "Microsoft.Extensions.Logging.Abstractions": "1.1.0-*"
+    "Microsoft.Extensions.Logging.Abstractions": "1.1.0-*",
+    "Microsoft.Extensions.TaskCache.Sources": {
+      "version": "1.1.0-*",
+      "type": "build"
+    }
   },
   "frameworks": {
     "net451": {

test/Microsoft.AspNetCore.Server.Kestrel.FunctionalTests/ResponseTests.cs

@@ -9,7 +9,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
+using Microsoft.Extensions.Internal;
 using Microsoft.Extensions.Primitives;
 using Xunit;
 
@@ -159,7 +159,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.FunctionalTests
                     {
                         await context.Response.WriteAsync("hello, world");
                         await context.Response.Body.FlushAsync();
-                        ex = Assert.Throws<InvalidOperationException>(() => context.Response.OnStarting(_ => TaskUtilities.CompletedTask, null));
+                        ex = Assert.Throws<InvalidOperationException>(() => context.Response.OnStarting(_ => TaskCache.CompletedTask, null));
                     });
                 });
 

test/Microsoft.AspNetCore.Server.KestrelTests/BadHttpRequestTests.cs

@@ -2,8 +2,8 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Testing;
+using Microsoft.Extensions.Internal;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Server.KestrelTests
@@ -73,7 +73,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
         [InlineData("post= / HTTP/1.0\r\n")]
         public async Task TestInvalidRequestLines(string request)
         {
-            using (var server = new TestServer(context => TaskUtilities.CompletedTask))
+            using (var server = new TestServer(context => TaskCache.CompletedTask))
             {
                 using (var connection = server.CreateConnection())
                 {
@@ -109,7 +109,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
         [InlineData("Header-1: value1\r\nHeader-2\t: value2\r\n\r\n")]
         public async Task TestInvalidHeaders(string rawHeaders)
         {
-            using (var server = new TestServer(context => TaskUtilities.CompletedTask))
+            using (var server = new TestServer(context => TaskCache.CompletedTask))
             {
                 using (var connection = server.CreateConnection())
                 {

test/Microsoft.AspNetCore.Server.KestrelTests/ConnectionTests.cs

@@ -3,10 +3,10 @@ using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Server.Kestrel;
 using Microsoft.AspNetCore.Server.Kestrel.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Http;
-using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Networking;
 using Microsoft.AspNetCore.Server.KestrelTests.TestHelpers;
 using Microsoft.AspNetCore.Testing;
+using Microsoft.Extensions.Internal;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Server.KestrelTests
@@ -26,7 +26,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 var context = new ListenerContext(new TestServiceContext())
                 {
                     FrameFactory = connectionContext => new Frame<HttpContext>(
-                        new DummyApplication(httpContext => TaskUtilities.CompletedTask), connectionContext),
+                        new DummyApplication(httpContext => TaskCache.CompletedTask), connectionContext),
                     ServerAddress = ServerAddress.FromUrl("http://127.0.0.1:0"),
                     Thread = engine.Threads[0]
                 };

test/Microsoft.AspNetCore.Server.KestrelTests/DefaultHeaderTests.cs

@@ -2,8 +2,8 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Testing;
+using Microsoft.Extensions.Internal;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Server.KestrelTests
@@ -18,7 +18,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 ServerOptions = { AddServerHeader = true }
             };
 
-            using (var server = new TestServer(ctx => TaskUtilities.CompletedTask, testContext))
+            using (var server = new TestServer(ctx => TaskCache.CompletedTask, testContext))
             {
                 using (var connection = server.CreateConnection())
                 {

test/Microsoft.AspNetCore.Server.KestrelTests/EngineTests.cs

@@ -16,6 +16,7 @@ using Microsoft.AspNetCore.Server.Kestrel.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Testing;
+using Microsoft.Extensions.Internal;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Server.KestrelTests
@@ -1084,7 +1085,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
             using (var server = new TestServer(httpContext =>
             {
                 httpContext.Abort();
-                return TaskUtilities.CompletedTask;
+                return TaskCache.CompletedTask;
             }, testContext))
             {
                 using (var connection = server.CreateConnection())
@@ -1121,7 +1122,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                     Assert.Same(originalRequestHeaders, requestFeature.Headers);
                 }
 
-                return TaskUtilities.CompletedTask;
+                return TaskCache.CompletedTask;
             }, testContext))
             {
                 using (var connection = server.CreateConnection())
@@ -1168,7 +1169,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                     Assert.Same(originalResponseHeaders, responseFeature.Headers);
                 }
 
-                return TaskUtilities.CompletedTask;
+                return TaskCache.CompletedTask;
             }, testContext))
             {
                 using (var connection = server.CreateConnection())
@@ -1234,12 +1235,12 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 context.Response.OnStarting(_ =>
                 {
                     callOrder.Push(1);
-                    return TaskUtilities.CompletedTask;
+                    return TaskCache.CompletedTask;
                 }, null);
                 context.Response.OnStarting(_ =>
                 {
                     callOrder.Push(2);
-                    return TaskUtilities.CompletedTask;
+                    return TaskCache.CompletedTask;
                 }, null);
                 
                 context.Response.ContentLength = response.Length;
@@ -1278,12 +1279,12 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 context.Response.OnCompleted(_ =>
                 {
                     callOrder.Push(1);
-                    return TaskUtilities.CompletedTask;
+                    return TaskCache.CompletedTask;
                 }, null);
                 context.Response.OnCompleted(_ =>
                 {
                     callOrder.Push(2);
-                    return TaskUtilities.CompletedTask;
+                    return TaskCache.CompletedTask;
                 }, null);
 
                 context.Response.ContentLength = response.Length;

test/Microsoft.AspNetCore.Server.KestrelTests/FrameTests.cs

@@ -11,6 +11,7 @@ using Microsoft.AspNetCore.Server.Kestrel.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Server.KestrelTests.TestHelpers;
 using Microsoft.AspNetCore.Testing;
+using Microsoft.Extensions.Internal;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Server.KestrelTests
@@ -629,7 +630,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
 
             // Act/Assert
             Assert.True(frame.HasResponseStarted);
-            Assert.Throws<InvalidOperationException>(() => ((IHttpResponseFeature)frame).OnStarting(_ => TaskUtilities.CompletedTask, null));
+            Assert.Throws<InvalidOperationException>(() => ((IHttpResponseFeature)frame).OnStarting(_ => TaskCache.CompletedTask, null));
         }
 
         [Fact]

test/Microsoft.AspNetCore.Server.KestrelTests/HttpsConnectionFilterTests.cs

@@ -17,6 +17,7 @@ using Microsoft.AspNetCore.Server.Kestrel.Filter;
 using Microsoft.AspNetCore.Server.Kestrel.Https;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Testing;
+using Microsoft.Extensions.Internal;
 using Microsoft.Extensions.Logging;
 using Moq;
 using Xunit;
@@ -113,7 +114,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 new NoOpConnectionFilter())
             );
 
-            using (var server = new TestServer(context => TaskUtilities.CompletedTask, serviceContext, _serverAddress))
+            using (var server = new TestServer(context => TaskCache.CompletedTask, serviceContext, _serverAddress))
             {
                 using (var client = new TcpClient())
                 {
@@ -231,7 +232,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 new NoOpConnectionFilter())
             );
 
-            using (var server = new TestServer(context => TaskUtilities.CompletedTask, serviceContext, _serverAddress))
+            using (var server = new TestServer(context => TaskCache.CompletedTask, serviceContext, _serverAddress))
             {
                 using (var client = new TcpClient())
                 {
@@ -258,7 +259,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 new NoOpConnectionFilter())
             );
 
-            using (var server = new TestServer(context => TaskUtilities.CompletedTask, serviceContext, _serverAddress))
+            using (var server = new TestServer(context => TaskCache.CompletedTask, serviceContext, _serverAddress))
             {
                 using (var client = new TcpClient())
                 {
@@ -283,7 +284,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 new NoOpConnectionFilter())
             );
 
-            using (var server = new TestServer(context => TaskUtilities.CompletedTask, serviceContext, _serverAddress))
+            using (var server = new TestServer(context => TaskCache.CompletedTask, serviceContext, _serverAddress))
             {
                 using (var client = new TcpClient())
                 {

test/Microsoft.AspNetCore.Server.KestrelTests/KestrelServerTests.cs

@@ -5,8 +5,8 @@ using System;
 using Microsoft.AspNetCore.Hosting.Server;
 using Microsoft.AspNetCore.Hosting.Server.Features;
 using Microsoft.AspNetCore.Server.Kestrel;
-using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Testing;
+using Microsoft.Extensions.Internal;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using Moq;
@@ -92,7 +92,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
 
         private static void StartDummyApplication(IServer server)
         {
-            server.Start(new DummyApplication(context => TaskUtilities.CompletedTask));
+            server.Start(new DummyApplication(context => TaskCache.CompletedTask));
         }
 
         private class TestLoggerFactory : ILoggerFactory

test/Microsoft.AspNetCore.Server.KestrelTests/TestHelpers/MockFrameControl.cs

@@ -5,7 +5,7 @@ using System;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Http;
-using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Server.KestrelTests.TestHelpers
 {
@@ -17,7 +17,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests.TestHelpers
 
         public Task FlushAsync(CancellationToken cancellationToken)
         {
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         public void ProduceContinue()
@@ -30,7 +30,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests.TestHelpers
 
         public Task WriteAsync(ArraySegment<byte> data, CancellationToken cancellationToken)
         {
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
     }
 }

test/Microsoft.AspNetCore.Server.KestrelTests/TestHelpers/MockSocketOuptut.cs

@@ -6,6 +6,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Server.KestrelTests.TestHelpers
 {
@@ -26,7 +27,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests.TestHelpers
 
         public Task WriteAsync(ArraySegment<byte> buffer, bool chunk = false, CancellationToken cancellationToken = default(CancellationToken))
         {
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
     }
 }

test/Microsoft.AspNetCore.Server.KestrelTests/TestHelpers/PassThroughConnectionFilter.cs

@@ -4,8 +4,8 @@
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Server.Kestrel.Filter;
 using Microsoft.AspNetCore.Server.Kestrel.Filter.Internal;
-using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Testing;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Server.KestrelTests
 {
@@ -15,7 +15,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
         public Task OnConnectionAsync(ConnectionFilterContext context)
         {
             context.Connection = new LoggingStream(context.Connection, new TestApplicationErrorLogger());
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
     }
 }

test/Microsoft.AspNetCore.Server.KestrelTests/TestInput.cs

@@ -10,6 +10,7 @@ using Microsoft.AspNetCore.Server.Kestrel.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Server.KestrelTests.TestHelpers;
 using Microsoft.AspNetCore.Testing;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Server.KestrelTests
 {
@@ -84,7 +85,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
 
         Task IFrameControl.WriteAsync(ArraySegment<byte> data, CancellationToken cancellationToken)
         {
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         void IFrameControl.Flush()
@@ -93,7 +94,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
 
         Task IFrameControl.FlushAsync(CancellationToken cancellationToken)
         {
-            return TaskUtilities.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         public void Dispose()