AsTask => GetAsTask()

src/Servers/Kestrel/Core/src/Internal/Http/Http1OutputProducer.cs

@@ -80,7 +80,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 return Task.FromCanceled(cancellationToken);
             }
 
-            return WriteAsync(buffer, cancellationToken).AsTask();
+            return WriteAsync(buffer, cancellationToken).GetAsTask();
         }
 
         public ValueTask<FlushResult> WriteDataToPipeAsync(ReadOnlySpan<byte> buffer, CancellationToken cancellationToken = default)

src/Servers/Kestrel/Core/src/Internal/Http/HttpProtocol.cs

@@ -796,7 +796,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         [MethodImpl(MethodImplOptions.NoInlining)]
         private Task FlushAsyncInternal()
         {
-            return Output.FlushAsync(default).AsTask();
+            return Output.FlushAsync(default).GetAsTask();
         }
 
         private void VerifyAndUpdateWrite(int count)
@@ -1374,7 +1374,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
 
         public Task FlushAsync(CancellationToken cancellationToken = default)
         {
-            return FlushPipeAsync(cancellationToken).AsTask();
+            return FlushPipeAsync(cancellationToken).GetAsTask();
         }
 
         [MethodImpl(MethodImplOptions.NoInlining)]
@@ -1386,7 +1386,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
 
         public Task WriteAsync(ReadOnlyMemory<byte> data, CancellationToken cancellationToken = default(CancellationToken))
         {
-            return WritePipeAsync(data, cancellationToken).AsTask();
+            return WritePipeAsync(data, cancellationToken).GetAsTask();
         }
 
         public async ValueTask<FlushResult> WriteAsyncAwaited(Task initializeTask, ReadOnlyMemory<byte> data, CancellationToken cancellationToken)

src/Servers/Kestrel/Core/src/Internal/Http/ValueTaskExtensions.cs

@@ -0,0 +1,27 @@
+// 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.IO.Pipelines;
+using System.Runtime.CompilerServices;
+using System.Threading.Tasks;
+
+namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
+{
+    internal static class ValueTaskExtensions
+    {
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static Task GetAsTask(this in ValueTask<FlushResult> valueTask)
+        {
+            if (valueTask.IsCompletedSuccessfully)
+            {
+                // Signal consumption to the IValueTaskSource
+                valueTask.GetAwaiter().GetResult();
+                return Task.CompletedTask;
+            }
+            else
+            {
+                return valueTask.AsTask();
+            }
+        }
+    }
+}

src/Servers/Kestrel/Core/src/Internal/Http2/Http2OutputProducer.cs

@@ -164,7 +164,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
                 _startedWritingDataFrames = true;
 
                 _dataPipe.Writer.Write(data);
-                return _flusher.FlushAsync(this, cancellationToken).AsTask();
+                return _flusher.FlushAsync(this, cancellationToken).GetAsTask();
             }
         }