Remove TaskCache and TaskCacheOfT

src/Microsoft.AspNetCore.Mvc.Core/AcceptedAtActionResult.cs

@@ -4,8 +4,8 @@
 using System;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Core;
-using Microsoft.AspNetCore.Routing;
 using Microsoft.AspNetCore.Mvc.Routing;
+using Microsoft.AspNetCore.Routing;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Net.Http.Headers;
 

src/Microsoft.AspNetCore.Mvc.Core/ActionResult.cs

@@ -23,7 +23,7 @@ namespace Microsoft.AspNetCore.Mvc
         public virtual Task ExecuteResultAsync(ActionContext context)
         {
             ExecuteResult(context);
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
 
         /// <summary>

src/Microsoft.AspNetCore.Mvc.Core/Filters/ExceptionFilterAttribute.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.Filters
 {
@@ -26,7 +25,7 @@ namespace Microsoft.AspNetCore.Mvc.Filters
             }
 
             OnException(context);
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
 
         /// <inheritdoc />

src/Microsoft.AspNetCore.Mvc.Core/Formatters/HttpNoContentOutputFormatter.cs

@@ -3,7 +3,6 @@
 
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.Formatters
 {
@@ -43,7 +42,7 @@ namespace Microsoft.AspNetCore.Mvc.Formatters
                 response.StatusCode = StatusCodes.Status204NoContent;
             }
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.Core/Formatters/StringOutputFormatter.cs

@@ -5,8 +5,6 @@ using System;
 using System.Text;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Mvc.Internal;
-using Microsoft.Extensions.Primitives;
 
 namespace Microsoft.AspNetCore.Mvc.Formatters
 {
@@ -53,7 +51,7 @@ namespace Microsoft.AspNetCore.Mvc.Formatters
             var valueAsString = (string)context.Object;
             if (string.IsNullOrEmpty(valueAsString))
             {
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             var response = context.HttpContext.Response;

src/Microsoft.AspNetCore.Mvc.Core/Formatters/TextOutputFormatter.cs

@@ -7,7 +7,6 @@ using System.Text;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Core;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.Extensions.Primitives;
 using Microsoft.Net.Http.Headers;
 
@@ -138,7 +137,7 @@ namespace Microsoft.AspNetCore.Mvc.Formatters
             {
                 var response = context.HttpContext.Response;
                 response.StatusCode = StatusCodes.Status406NotAcceptable;
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             context.ContentType = selectedMediaType;

src/Microsoft.AspNetCore.Mvc.Core/Internal/ControllerActionInvoker.cs

@@ -239,7 +239,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                             }
 
                             isCompleted = true;
-                            return TaskCache.CompletedTask;
+                            return Task.CompletedTask;
                         }
 
                         var actionExecutedContext = _actionExecutedContext;
@@ -251,7 +251,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                         }
 
                         isCompleted = true;
-                        return TaskCache.CompletedTask;
+                        return Task.CompletedTask;
                     }
 
                 default:
@@ -459,7 +459,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             if (actionDescriptor.BoundProperties.Count == 0 &&
                 actionDescriptor.Parameters.Count == 0)
             {
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             Debug.Assert(_cacheEntry.ControllerBinderDelegate != null);

src/Microsoft.AspNetCore.Mvc.Core/Internal/MvcAttributeRouteHandler.cs

@@ -4,7 +4,6 @@
 using System;
 using System.Diagnostics;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Abstractions;
 using Microsoft.AspNetCore.Mvc.Core;
 using Microsoft.AspNetCore.Mvc.Infrastructure;
@@ -79,7 +78,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             if (actionDescriptor == null)
             {
                 _logger.NoActionsMatched(context.RouteData.Values);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             foreach (var kvp in actionDescriptor.RouteValues)
@@ -111,7 +110,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 return invoker.InvokeAsync();
             };
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.Core/Internal/MvcRouteHandler.cs

@@ -67,14 +67,14 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             if (candidates == null || candidates.Count == 0)
             {
                 _logger.NoActionsMatched(context.RouteData.Values);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             var actionDescriptor = _actionSelector.SelectBestCandidate(context, candidates);
             if (actionDescriptor == null)
             {
                 _logger.NoActionsMatched(context.RouteData.Values);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             context.Handler = (c) =>
@@ -98,7 +98,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 return invoker.InvokeAsync();
             };
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.Core/Internal/NoOpBinder.cs

@@ -12,7 +12,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
 
         public Task BindModelAsync(ModelBindingContext bindingContext)
         {
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.Core/Internal/ObjectResultExecutor.cs

@@ -149,7 +149,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 Logger.NoFormatter(formatterContext);
 
                 context.HttpContext.Response.StatusCode = StatusCodes.Status406NotAcceptable;
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             Logger.FormatterSelected(selectedFormatter, formatterContext);

src/Microsoft.AspNetCore.Mvc.Core/Internal/ResourceInvoker.cs

@@ -624,7 +624,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                         if (scope == Scope.Exception)
                         {
                             isCompleted = true;
-                            return TaskCache.CompletedTask;
+                            return Task.CompletedTask;
                         }
 
                         if (exceptionContext != null)
@@ -662,7 +662,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                             // If we're inside an exception filter, let's allow those filters to 'unwind' before
                             // the result.
                             isCompleted = true;
-                            return TaskCache.CompletedTask;
+                            return Task.CompletedTask;
                         }
 
                         Debug.Assert(scope == Scope.Invoker || scope == Scope.Resource);
@@ -847,7 +847,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                             }
 
                             isCompleted = true;
-                            return TaskCache.CompletedTask;
+                            return Task.CompletedTask;
                         }
 
                         Rethrow(_resultExecutedContext);
@@ -877,7 +877,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                         if (scope == Scope.Resource)
                         {
                             isCompleted = true;
-                            return TaskCache.CompletedTask;
+                            return Task.CompletedTask;
                         }
 
                         Debug.Assert(scope == Scope.Invoker);
@@ -889,7 +889,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 case State.InvokeEnd:
                     {
                         isCompleted = true;
-                        return TaskCache.CompletedTask;
+                        return Task.CompletedTask;
                     }
 
                 default:

src/Microsoft.AspNetCore.Mvc.Core/Internal/TaskCache.cs

@@ -1,20 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System.Threading.Tasks;
-
-namespace Microsoft.AspNetCore.Mvc.Internal
-{
-    public static class TaskCache
-    {
-
-        /// <summary>
-        /// A <see cref="Task"/> that's already completed successfully.
-        /// </summary>
-        /// <remarks>
-        /// We're caching this in a static readonly field to make it more inlinable and avoid the volatile lookup done
-        /// by <c>Task.CompletedTask</c>.
-        /// </remarks>
-        public static readonly Task CompletedTask = Task.CompletedTask;
-    }
-}

src/Microsoft.AspNetCore.Mvc.Core/Internal/TaskCacheOfT.cs

@@ -1,18 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System.Threading.Tasks;
-
-namespace Microsoft.AspNetCore.Mvc.Internal
-{
-    public static class TaskCache<T>
-    {
-        private static readonly Task<T> _defaultCompletedTask = Task.FromResult(default(T));
-
-        /// <summary>
-        /// Gets a completed <see cref="Task"/> with the value of <c>default(T)</c>.
-        /// </summary>
-        public static Task<T> DefaultCompletedTask => _defaultCompletedTask;
-    }
-
-}

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/ByteArrayModelBinder.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
 {
@@ -24,7 +23,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var valueProviderResult = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
             if (valueProviderResult == ValueProviderResult.None)
             {
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             bindingContext.ModelState.SetModelValue(bindingContext.ModelName, valueProviderResult);
@@ -33,14 +32,14 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             var value = valueProviderResult.FirstValue;
             if (string.IsNullOrEmpty(value))
             {
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             try
             {
                 var model = Convert.FromBase64String(value);
                 bindingContext.Result = ModelBindingResult.Success(model);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
             catch (Exception exception)
             {
@@ -48,7 +47,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                     bindingContext.ModelName,
                     exception,
                     bindingContext.ModelMetadata);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
         }
     }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/CancellationTokenModelBinder.cs

@@ -5,7 +5,6 @@ using System;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
 {
@@ -30,7 +29,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             bindingContext.ValidationState.Add(model, new ValidationStateEntry() { SuppressValidation = true });
             bindingContext.Result = ModelBindingResult.Success(model);
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/ComplexTypeModelBinder.cs

@@ -7,7 +7,6 @@ using System.Linq.Expressions;
 using System.Reflection;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc.Core;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
 {
@@ -45,7 +44,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
 
             if (!CanCreateModel(bindingContext))
             {
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             // Perf: separated to avoid allocating a state machine when we don't

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/HeaderModelBinder.cs

@@ -4,7 +4,6 @@
 using System;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
@@ -63,7 +62,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                 bindingContext.Result = ModelBindingResult.Success(model);
             }
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
 
         private static object GetCompatibleCollection(ModelBindingContext bindingContext, string[] values)

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/ServicesModelBinder.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
 using Microsoft.Extensions.DependencyInjection;
 
@@ -29,7 +28,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             bindingContext.ValidationState.Add(model, new ValidationStateEntry() { SuppressValidation = true });
 
             bindingContext.Result = ModelBindingResult.Success(model);
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/Binders/SimpleTypeModelBinder.cs

@@ -5,7 +5,6 @@ using System;
 using System.ComponentModel;
 using System.Runtime.ExceptionServices;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
 {
@@ -38,7 +37,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             if (valueProviderResult == ValueProviderResult.None)
             {
                 // no entry
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             bindingContext.ModelState.SetModelValue(bindingContext.ModelName, valueProviderResult);
@@ -83,12 +82,12 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                         bindingContext.ModelMetadata.ModelBindingMessageProvider.ValueMustNotBeNullAccessor(
                             valueProviderResult.ToString()));
 
-                    return TaskCache.CompletedTask;
+                    return Task.CompletedTask;
                 }
                 else
                 {
                     bindingContext.Result = ModelBindingResult.Success(model);
-                    return TaskCache.CompletedTask;
+                    return Task.CompletedTask;
                 }
             }
             catch (Exception exception)
@@ -107,7 +106,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                     bindingContext.ModelMetadata);
 
                 // Were able to find a converter for the type but conversion failed.
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
         }
     }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/FormValueProviderFactory.cs

@@ -4,8 +4,6 @@
 using System;
 using System.Globalization;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding
 {
@@ -29,7 +27,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
                 return AddValueProviderAsync(context);
             }
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
 
         private static async Task AddValueProviderAsync(ValueProviderFactoryContext context)

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/JQueryFormValueProviderFactory.cs

@@ -8,7 +8,6 @@ using System.Text;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Core;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.Extensions.Primitives;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding
@@ -33,7 +32,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
                 return AddValueProviderAsync(context);
             }
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
 
         private static async Task AddValueProviderAsync(ValueProviderFactoryContext context)

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/QueryStringValueProviderFactory.cs

@@ -4,7 +4,6 @@
 using System;
 using System.Globalization;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding
 {
@@ -29,7 +28,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
 
             context.ValueProviders.Add(valueProvider);
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.Core/ModelBinding/RouteValueProviderFactory.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ModelBinding
 {
@@ -26,7 +25,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
 
             context.ValueProviders.Add(valueProvider);
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.Cors/Internal/DisableCorsAuthorizationFilter.cs

@@ -48,7 +48,7 @@ namespace Microsoft.AspNetCore.Mvc.Cors.Internal
             }
 
             // Let the action be executed.
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.Formatters.Json/Internal/JsonResultExecutor.cs

@@ -131,7 +131,7 @@ namespace Microsoft.AspNetCore.Mvc.Formatters.Json.Internal
                 }
             }
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.ViewFeatures/Internal/NullView.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.Rendering;
 using Microsoft.AspNetCore.Mvc.ViewEngines;
 
@@ -22,7 +21,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
                 throw new ArgumentNullException(nameof(context));
             }
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.ViewFeatures/Internal/SaveTempDataFilter.cs

@@ -2,9 +2,9 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Collections.Generic;
+using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Filters;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
 {
@@ -41,10 +41,9 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
                     // Example: An action returns NoContentResult and since NoContentResult does not write anything to
                     // the body of the response, this delegate would get executed way late in the pipeline at which point
                     // the session feature would have been removed.
-                    object obj;
+                    if (saveTempDataContext.HttpContext.Items.TryGetValue(TempDataSavedKey, out var obj))
-                    if (saveTempDataContext.HttpContext.Items.TryGetValue(TempDataSavedKey, out obj))
                     {
-                        return TaskCache.CompletedTask;
+                        return Task.CompletedTask;
                     }
 
                     SaveTempData(
@@ -53,7 +52,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
                         filters: saveTempDataContext.Filters,
                         httpContext: saveTempDataContext.HttpContext);
 
-                    return TaskCache.CompletedTask;
+                    return Task.CompletedTask;
                 },
                 state: new SaveTempDataContext()
                 {

src/Microsoft.AspNetCore.Mvc.ViewFeatures/Internal/ViewBufferTextWriter.cs

@@ -7,7 +7,6 @@ using System.Text;
 using System.Text.Encodings.Web;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Html;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
 {
@@ -253,7 +252,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
             if (IsBuffering)
             {
                 Buffer.AppendHtml(value.ToString());
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
             else
             {
@@ -281,7 +280,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
             if (IsBuffering)
             {
                 Buffer.AppendHtml(new string(buffer, index, count));
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
             else
             {
@@ -295,7 +294,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
             if (IsBuffering)
             {
                 Buffer.AppendHtml(value);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
             else
             {
@@ -337,7 +336,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
             {
                 Buffer.AppendHtml(value.ToString());
                 Buffer.AppendHtml(NewLine);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
             else
             {
@@ -352,7 +351,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
             {
                 Buffer.AppendHtml(new string(value, start, offset));
                 Buffer.AppendHtml(NewLine);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
             else
             {
@@ -367,7 +366,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
             {
                 Buffer.AppendHtml(value);
                 Buffer.AppendHtml(NewLine);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
             else
             {
@@ -381,7 +380,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
             if (IsBuffering)
             {
                 Buffer.AppendHtml(NewLine);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
             else
             {

src/Microsoft.AspNetCore.Mvc.ViewFeatures/ViewComponents/ContentViewComponentResult.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ViewComponents
 {
@@ -58,7 +57,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewComponents
         {
             Execute(context);
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.ViewFeatures/ViewComponents/HtmlContentViewComponentResult.cs

@@ -4,7 +4,6 @@
 using System;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Html;
-using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ViewComponents
 {
@@ -58,7 +57,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewComponents
         {
             Execute(context);
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.WebApiCompatShim/HttpRequestMessage/HttpRequestMessageModelBinder.cs

@@ -3,7 +3,6 @@
 
 using System.Net.Http;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
 
@@ -21,7 +20,7 @@ namespace Microsoft.AspNetCore.Mvc.WebApiCompatShim
             bindingContext.ValidationState.Add(model, new ValidationStateEntry() { SuppressValidation = true });
             bindingContext.Result = ModelBindingResult.Success(model);
 
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

test/Microsoft.AspNetCore.Mvc.Core.Test/ForbidResultTest.cs

@@ -6,7 +6,6 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Abstractions;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Routing;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
@@ -26,7 +25,7 @@ namespace Microsoft.AspNetCore.Mvc
             var auth = new Mock<IAuthenticationService>();
             auth
                 .Setup(c => c.ForbidAsync(httpContext.Object, "", null))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.CompletedTask)
                 .Verifiable();
             httpContext.Setup(c => c.RequestServices).Returns(CreateServices(auth.Object));
             var result = new ForbidResult("", null);
@@ -53,11 +52,11 @@ namespace Microsoft.AspNetCore.Mvc
             var auth = new Mock<IAuthenticationService>();
             auth
                 .Setup(c => c.ForbidAsync(httpContext.Object, "Scheme1", authProperties))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.CompletedTask)
                 .Verifiable();
             auth
                 .Setup(c => c.ForbidAsync(httpContext.Object, "Scheme2", authProperties))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.CompletedTask)
                 .Verifiable();
             httpContext.Setup(c => c.RequestServices).Returns(CreateServices(auth.Object));
             var result = new ForbidResult(new[] { "Scheme1", "Scheme2" }, authProperties);
@@ -91,7 +90,7 @@ namespace Microsoft.AspNetCore.Mvc
             var auth = new Mock<IAuthenticationService>();
             auth
                 .Setup(c => c.ForbidAsync(httpContext.Object, null, expected))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.CompletedTask)
                 .Verifiable();
             httpContext.Setup(c => c.RequestServices).Returns(CreateServices(auth.Object));
             var result = new ForbidResult(expected);
@@ -119,7 +118,7 @@ namespace Microsoft.AspNetCore.Mvc
             var auth = new Mock<IAuthenticationService>();
             auth
                 .Setup(c => c.ForbidAsync(httpContext.Object, null, expected))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.CompletedTask)
                 .Verifiable();
             httpContext.Setup(c => c.RequestServices).Returns(CreateServices(auth.Object));
             var result = new ForbidResult(expected)

test/Microsoft.AspNetCore.Mvc.Core.Test/Internal/AttributeRouteTest.cs

@@ -69,9 +69,9 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                             selected = actions[1];
                         }
 
-                        routeContext.Handler = (c) => TaskCache.CompletedTask;
+                        routeContext.Handler = (c) => Task.CompletedTask;
 
-                        return TaskCache.CompletedTask;
+                        return Task.CompletedTask;
 
                     });
                 return handler.Object;
@@ -788,7 +788,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             handler
                 .Setup(h => h.RouteAsync(It.IsAny<RouteContext>()))
                 .Callback<RouteContext>(c => c.Handler = NullHandler)
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.CompletedTask)
                 .Verifiable();
             return handler;
         }

test/Microsoft.AspNetCore.Mvc.Core.Test/Internal/ControllerBinderDelegateProviderTest.cs

@@ -37,7 +37,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             var binder = new Mock<IModelBinder>();
             binder
                 .Setup(b => b.BindModelAsync(It.IsAny<DefaultModelBindingContext>()))
-                .Returns(TaskCache.CompletedTask);
+                .Returns(Task.CompletedTask);
             var factory = GetModelBinderFactory(binder.Object);
             var parameterBinder = GetParameterBinder(factory);
 
@@ -74,7 +74,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             var binder = new Mock<IModelBinder>();
             binder
                 .Setup(b => b.BindModelAsync(It.IsAny<DefaultModelBindingContext>()))
-                .Returns(TaskCache.CompletedTask);
+                .Returns(Task.CompletedTask);
             var factory = GetModelBinderFactory(binder.Object);
             var parameterBinder = GetParameterBinder(factory);
 
@@ -120,7 +120,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                     context.ModelMetadata = metadataProvider.GetMetadataForType(typeof(string));
                     context.Result = ModelBindingResult.Success(value);
                 })
-                .Returns(TaskCache.CompletedTask);
+                .Returns(Task.CompletedTask);
             var factory = GetModelBinderFactory(binder.Object);
             var parameterBinder = GetParameterBinder(factory);
 
@@ -209,7 +209,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             var binder = new Mock<IModelBinder>();
             binder
                 .Setup(b => b.BindModelAsync(It.IsAny<DefaultModelBindingContext>()))
-                .Returns(TaskCache.CompletedTask);
+                .Returns(Task.CompletedTask);
 
             var mockValidator = new Mock<IObjectModelValidator>(MockBehavior.Strict);
             mockValidator
@@ -308,7 +308,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             var binder = new Mock<IModelBinder>();
             binder
                 .Setup(b => b.BindModelAsync(It.IsAny<DefaultModelBindingContext>()))
-                .Returns(TaskCache.CompletedTask);
+                .Returns(Task.CompletedTask);
 
             var mockValidator = new Mock<IObjectModelValidator>(MockBehavior.Strict);
             mockValidator
@@ -821,7 +821,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 .Returns<DefaultModelBindingContext>(mbc =>
                 {
                     mbc.Result = ModelBindingResult.Success(model);
-                    return TaskCache.CompletedTask;
+                    return Task.CompletedTask;
                 });
 
             return GetModelBinderFactory(binder.Object);

test/Microsoft.AspNetCore.Mvc.Core.Test/Internal/MiddlewareFilterTest.cs

@@ -475,7 +475,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                     arguments.Add(entry.Key, entry.Value);
                 }
 
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
         }
 

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/BinderTypeModelBinderTest.cs

@@ -116,7 +116,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
             public Task BindModelAsync(ModelBindingContext bindingContext)
             {
                 bindingContext.Result = ModelBindingResult.Success(_model);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
         }
     }

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/Binders/ComplexTypeModelBinderTest.cs

@@ -1374,7 +1374,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
                     bindingContext.Result = result;
                 }
 
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
 
             protected override Task BindProperty(ModelBindingContext bindingContext)

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/ParameterBinderTest.cs

@@ -64,7 +64,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
                 {
                     Assert.Equal(expectedModelName, context.ModelName, StringComparer.Ordinal);
                 })
-                .Returns(TaskCache.CompletedTask);
+                .Returns(Task.CompletedTask);
 
             var parameterDescriptor = new ParameterDescriptor
             {
@@ -115,7 +115,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
                 {
                     Assert.Equal(expectedModelName, context.ModelName, StringComparer.Ordinal);
                 })
-                .Returns(TaskCache.CompletedTask);
+                .Returns(Task.CompletedTask);
 
             var parameterDescriptor = new ParameterDescriptor
             {

test/Microsoft.AspNetCore.Mvc.Core.Test/ModelBinding/StubModelBinder.cs

@@ -14,7 +14,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
 
         public StubModelBinder()
         {
-            _callback = context => TaskCache.CompletedTask;
+            _callback = context => Task.CompletedTask;
         }
 
         public StubModelBinder(ModelBindingResult result)
@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             _callback = context =>
             {
                 context.Result = result;
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             };
         }
 
@@ -31,7 +31,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             _callback = context =>
             {
                 callback(context);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             };
         }
 
@@ -41,7 +41,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
             {
                 var result = callback.Invoke(context);
                 context.Result = result;
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             };
         }
 

test/Microsoft.AspNetCore.Mvc.Core.Test/SignInResultTest.cs

@@ -7,7 +7,6 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Abstractions;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Routing;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
@@ -28,7 +27,7 @@ namespace Microsoft.AspNetCore.Mvc
             var auth = new Mock<IAuthenticationService>();
             auth
                 .Setup(c => c.SignInAsync(httpContext.Object, "", principal, null))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.CompletedTask)
                 .Verifiable();
             httpContext.Setup(c => c.RequestServices).Returns(CreateServices(auth.Object));
             var result = new SignInResult("", principal, null);
@@ -56,7 +55,7 @@ namespace Microsoft.AspNetCore.Mvc
             var auth = new Mock<IAuthenticationService>();
             auth
                 .Setup(c => c.SignInAsync(httpContext.Object, "Scheme1", principal, authProperties))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.CompletedTask)
                 .Verifiable();
             httpContext.Setup(c => c.RequestServices).Returns(CreateServices(auth.Object));
             var result = new SignInResult("Scheme1", principal, authProperties);

test/Microsoft.AspNetCore.Mvc.Core.Test/SignOutResultTest.cs

@@ -6,7 +6,6 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Abstractions;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Routing;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
@@ -26,7 +25,7 @@ namespace Microsoft.AspNetCore.Mvc
             var auth = new Mock<IAuthenticationService>();
             auth
                 .Setup(c => c.SignOutAsync(httpContext.Object, "", null))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.CompletedTask)
                 .Verifiable();
             httpContext.Setup(c => c.RequestServices).Returns(CreateServices(auth.Object));
             var result = new SignOutResult("", null);
@@ -53,11 +52,11 @@ namespace Microsoft.AspNetCore.Mvc
             var auth = new Mock<IAuthenticationService>();
             auth
                 .Setup(c => c.SignOutAsync(httpContext.Object, "Scheme1", authProperties))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.CompletedTask)
                 .Verifiable();
             auth
                 .Setup(c => c.SignOutAsync(httpContext.Object, "Scheme2", authProperties))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.CompletedTask)
                 .Verifiable();
             httpContext.Setup(c => c.RequestServices).Returns(CreateServices(auth.Object));
             var result = new SignOutResult(new[] { "Scheme1", "Scheme2" }, authProperties);

test/Microsoft.AspNetCore.Mvc.IntegrationTests/BinderTypeBasedModelBinderIntegrationTest.cs

@@ -5,7 +5,6 @@ using System;
 using System.Diagnostics;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc.Abstractions;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Testing;
 using Xunit;
@@ -327,7 +326,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
 
                 if (bindingContext.ModelType != typeof(Address))
                 {
-                    return TaskCache.CompletedTask;
+                    return Task.CompletedTask;
                 }
 
                 var address = new Address() { Street = "SomeStreet" };
@@ -338,7 +337,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
                     address.Street);
 
                 bindingContext.Result = ModelBindingResult.Success(address);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
         }
 
@@ -355,7 +354,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
 
                 if (bindingContext.ModelType != typeof(Address3))
                 {
-                    return TaskCache.CompletedTask;
+                    return Task.CompletedTask;
                 }
 
                 var address = new Address3 { Street = "SomeStreet" };
@@ -366,7 +365,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
                     address.Street);
 
                 bindingContext.Result = ModelBindingResult.Success(address);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
         }
 
@@ -387,7 +386,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
                     model);
 
                 bindingContext.Result =ModelBindingResult.Success(model);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
         }
 
@@ -402,7 +401,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
                 Debug.Assert(bindingContext.Result == ModelBindingResult.Failed());
 
                 bindingContext.Result =  ModelBindingResult.Success(model: null);
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
         }
 
@@ -417,7 +416,7 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
                 Debug.Assert(bindingContext.Result == ModelBindingResult.Failed());
 
                 bindingContext.Result = ModelBindingResult.Failed();
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
         }
     }

test/Microsoft.AspNetCore.Mvc.IntegrationTests/GenericModelBinderIntegrationTest.cs

@@ -7,7 +7,6 @@ using System.Diagnostics;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Abstractions;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Xunit;
 
@@ -183,11 +182,11 @@ namespace Microsoft.AspNetCore.Mvc.IntegrationTests
                 {
                     // Binding Sources are opt-in. This model either didn't specify one or specified something
                     // incompatible so let other binders run.
-                    return TaskCache.CompletedTask;
+                    return Task.CompletedTask;
                 }
 
                 bindingContext.Result = ModelBindingResult.Success(new Address());
-                return TaskCache.CompletedTask;
+                return Task.CompletedTask;
             }
         }
 

test/Microsoft.AspNetCore.Mvc.TestCommon/SimpleValueProviderFactory.cs

@@ -30,7 +30,7 @@ namespace Microsoft.AspNetCore.Mvc.ModelBinding
         public Task CreateValueProviderAsync(ValueProviderFactoryContext context)
         {
             context.ValueProviders.Add(_valueProvider);
-            return TaskCache.CompletedTask;
+            return Task.CompletedTask;
         }
     }
 }

test/WebSites/RazorPagesWebSite/HandlerTestPage.cshtml

@@ -1,6 +1,5 @@
 @page "{handler?}"
 
-@using Microsoft.AspNetCore.Mvc.Internal
 @using RazorPagesWebSite
 
 @functions{
@@ -13,26 +12,26 @@
 
     public async Task<IActionResult> OnPostAsync()
     {
-        await TaskCache.CompletedTask;
+        await Task.CompletedTask;
         MethodName = nameof(OnPostAsync);
         return Page();
     }
 
     public async Task OnGetCustomer()
     {
-        await TaskCache.CompletedTask;
+        await Task.CompletedTask;
         MethodName = nameof(OnGetCustomer);
     }
 
     public async Task OnGetViewCustomerAsync()
     {
-        await TaskCache.CompletedTask;
+        await Task.CompletedTask;
         MethodName = nameof(OnGetViewCustomerAsync);
     }
 
     public async Task<CustomActionResult> OnPostCustomActionResult()
     {
-        await TaskCache.CompletedTask;
+        await Task.CompletedTask;
         return new CustomActionResult();
     }
 

test/WebSites/RazorPagesWebSite/ModelHandlerTestModel.cs

@@ -3,7 +3,6 @@
 
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc;
-using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.RazorPages;
 
 namespace RazorPagesWebSite
@@ -19,26 +18,26 @@ namespace RazorPagesWebSite
 
         public async Task<IActionResult> OnPostAsync()
         {
-            await TaskCache.CompletedTask;
+            await Task.CompletedTask;
             MethodName = nameof(OnPostAsync);
             return Page();
         }
 
         public async Task OnGetCustomer()
         {
-            await TaskCache.CompletedTask;
+            await Task.CompletedTask;
             MethodName = nameof(OnGetCustomer);
         }
 
         public async Task OnGetViewCustomerAsync()
         {
-            await TaskCache.CompletedTask;
+            await Task.CompletedTask;
             MethodName = nameof(OnGetViewCustomerAsync);
         }
 
         public async Task<CustomActionResult> OnPostCustomActionResult()
         {
-            await TaskCache.CompletedTask;
+            await Task.CompletedTask;
             return new CustomActionResult();
         }