Added a ConnectionAbortedException to Transport.Abstractions (#1806)

* Added a ConnectionAbortedException to Transport.Abstractions
- To avoid hard coding TaskCanceledException in each transport
- This PR tries to keep compatibility by converting the ConnectionAbortedException
to a TaskCanceledException on exceptions in FrameRequestStream. The downside is that
this conversion causes an async state machine to be created per call to ReadAsync.
CopyToAsync isn't that bad because it's a single long running task.

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

@@ -3,9 +3,11 @@
 
 using System;
 using System.IO;
+using System.Runtime.ExceptionServices;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions;
 using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
@@ -105,11 +107,24 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         public override Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
             var task = ValidateState(cancellationToken);
-            if (task == null)
+            if (task != null)
             {
-                return _body.ReadAsync(new ArraySegment<byte>(buffer, offset, count), cancellationToken);
+                return task;
+            }
+
+            return ReadAsyncInternal(buffer, offset, count, cancellationToken);
+        }
+
+        private async Task<int> ReadAsyncInternal(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+            try
+            {
+                return await _body.ReadAsync(new ArraySegment<byte>(buffer, offset, count), cancellationToken);
+            }
+            catch (ConnectionAbortedException ex)
+            {
+                throw new TaskCanceledException("The request was aborted", ex);
             }
-            return task;
         }
 
         public override Task CopyToAsync(Stream destination, int bufferSize, CancellationToken cancellationToken)
@@ -124,11 +139,24 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             }
 
             var task = ValidateState(cancellationToken);
-            if (task == null)
+            if (task != null)
             {
-                return _body.CopyToAsync(destination, cancellationToken);
+                return task;
+            }
+
+            return CopyToAsyncInternal(destination, cancellationToken);
+        }
+
+        private async Task CopyToAsyncInternal(Stream destination, CancellationToken cancellationToken)
+        {
+            try
+            {
+                await _body.CopyToAsync(destination, cancellationToken);
+            }
+            catch (ConnectionAbortedException ex)
+            {
+                throw new TaskCanceledException("The request was aborted", ex);
             }
-            return task;
         }
 
         public void StartAcceptingReads(MessageBody body)
@@ -165,7 +193,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         public void Abort(Exception error = null)
         {
             // We don't want to throw an ODE until the app func actually completes.
-            // If the request is aborted, we throw an TaskCanceledException instead,
+            // If the request is aborted, we throw a TaskCanceledException instead,
             // unless error is not null, in which case we throw it.
             if (_state != FrameStreamState.Closed)
             {

src/Microsoft.AspNetCore.Server.Kestrel.Core/Internal/Infrastructure/FrameConnectionManagerShutdownExtensions.cs

@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure
 {
@@ -25,7 +26,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure
         public static async Task<bool> AbortAllConnectionsAsync(this FrameConnectionManager connectionManager)
         {
             var abortTasks = new List<Task>();
-            var canceledException = new TaskCanceledException(CoreStrings.RequestProcessingAborted);
+            var canceledException = new ConnectionAbortedException();
 
             connectionManager.Walk(connection =>
             {

src/Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions/Exceptions/ConnectionAbortedException.cs

@@ -0,0 +1,21 @@
+using System;
+
+namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions
+{
+    public class ConnectionAbortedException : OperationCanceledException
+    {
+        public ConnectionAbortedException() :
+            this("The connection was aborted")
+        {
+
+        }
+
+        public ConnectionAbortedException(string message) : base(message)
+        {
+        }
+
+        public ConnectionAbortedException(string message, Exception inner) : base(message, inner)
+        {
+        }
+    }
+}

src/Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv/Internal/LibuvConnection.cs

@@ -86,7 +86,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal
                     Input.CancelPendingFlush();
 
                     // Now, complete the input so that no more reads can happen
-                    Input.Complete(new TaskCanceledException("The request was aborted"));
+                    Input.Complete(new ConnectionAbortedException());
 
                     // We're done with the socket now
                     _socket.Dispose();

src/Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets/SocketConnection.cs

@@ -115,11 +115,11 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets
             }
             catch (SocketException ex) when (ex.SocketErrorCode == SocketError.OperationAborted)
             {
-                error = new TaskCanceledException("The request was aborted");
+                error = new ConnectionAbortedException();
             }
             catch (ObjectDisposedException)
             {
-                error = new TaskCanceledException("The request was aborted");
+                error = new ConnectionAbortedException();
             }
             catch (IOException ex)
             {