Abort connections not closed during shutdown (#1112).

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

@@ -142,7 +142,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
             return _socketClosedTcs.Task;
         }
 
-        public virtual void Abort(Exception error = null)
+        public virtual Task AbortAsync(Exception error = null)
         {
             // Frame.Abort calls user code while this method is always
             // called from a libuv thread.
@@ -150,6 +150,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
             {
                 _frame.Abort(error);
             });
+
+            return _socketClosedTcs.Task;
         }
 
         // Called on Libuv thread
@@ -285,7 +287,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
 
             if (!normalRead)
             {
-                Abort(error);
+                AbortAsync(error);
             }
         }
 

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

@@ -3,7 +3,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Networking;
@@ -22,17 +21,37 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
         }
 
         public async Task<bool> WalkConnectionsAndCloseAsync(TimeSpan timeout)
+        {
+            return await WalkConnectionsAsync((connectionManager, tcs) => connectionManager.WalkConnectionsAndCloseCore(tcs), timeout).ConfigureAwait(false);
+        }
+
+        public async Task<bool> WalkConnectionsAndAbortAsync(TimeSpan timeout)
+        {
+            return await WalkConnectionsAsync((connectionManager, tcs) => connectionManager.WalkConnectionsAndAbortCore(tcs), timeout).ConfigureAwait(false);
+        }
+
+        private async Task<bool> WalkConnectionsAsync(Action<ConnectionManager, TaskCompletionSource<object>> action, TimeSpan timeout)
         {
             var tcs = new TaskCompletionSource<object>();
 
-            _thread.Post(state => ((ConnectionManager)state).WalkConnectionsAndCloseCore(tcs), this);
+            _thread.Post(state => action((ConnectionManager)state, tcs), this);
 
             return await Task.WhenAny(tcs.Task, Task.Delay(timeout)).ConfigureAwait(false) == tcs.Task;
         }
 
         private void WalkConnectionsAndCloseCore(TaskCompletionSource<object> tcs)
         {
-            var connectionStopTasks = new List<Task>();
+            WalkConnectionsCore(connection => connection.StopAsync(), tcs);
+        }
+
+        private void WalkConnectionsAndAbortCore(TaskCompletionSource<object> tcs)
+        {
+            WalkConnectionsCore(connection => connection.AbortAsync(), tcs);
+        }
+
+        private void WalkConnectionsCore(Func<Connection, Task> action, TaskCompletionSource<object> tcs)
+        {
+            var tasks = new List<Task>();
 
             _thread.Walk(ptr =>
             {
@@ -41,13 +60,13 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
 
                 if (connection != null)
                 {
-                    connectionStopTasks.Add(connection.StopAsync());
+                    tasks.Add(action(connection));
                 }
             });
 
             _threadPool.Run(() =>
             {
-                Task.WaitAll(connectionStopTasks.ToArray());
+                Task.WaitAll(tasks.ToArray());
                 tcs.SetResult(null);
             });
         }

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

@@ -158,7 +158,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
                     {
                         if (cancellationToken.IsCancellationRequested)
                         {
-                            _connection.Abort();
+                            _connection.AbortAsync();
                             _cancelled = true;
                             return TaskUtilities.GetCancelledTask(cancellationToken);
                         }
@@ -304,7 +304,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
                 {
                     // Abort the connection for any failed write
                     // Queued on threadpool so get it in as first op.
-                    _connection.Abort();
+                    _connection.AbortAsync();
                     _cancelled = true;
 
                     CompleteAllWrites();
@@ -374,7 +374,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
             {
                 // Abort the connection for any failed write
                 // Queued on threadpool so get it in as first op.
-                _connection.Abort();
+                _connection.AbortAsync();
                 _cancelled = true;
                 _lastWriteError = error;
             }
@@ -532,7 +532,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
         {
             if (cancellationToken.IsCancellationRequested)
             {
-                _connection.Abort();
+                _connection.AbortAsync();
                 _cancelled = true;
                 return TaskUtilities.GetCancelledTask(cancellationToken);
             }

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

@@ -43,6 +43,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure
 
         void NotAllConnectionsClosedGracefully();
 
+        void NotAllConnectionsAborted();
+
         void ApplicationError(string connectionId, Exception ex);
     }
 }

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

@@ -165,6 +165,11 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal
                 if (!await ConnectionManager.WalkConnectionsAndCloseAsync(_shutdownTimeout).ConfigureAwait(false))
                 {
                     _log.NotAllConnectionsClosedGracefully();
+
+                    if (!await ConnectionManager.WalkConnectionsAndAbortAsync(TimeSpan.FromSeconds(1)).ConfigureAwait(false))
+                    {
+                        _log.NotAllConnectionsAborted();
+                    }
                 }
 
                 var result = await WaitAsync(PostAsync(state =>
@@ -281,7 +286,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal
         {
             lock (_startSync)
             {
-                var tcs = (TaskCompletionSource<int>) parameter;
+                var tcs = (TaskCompletionSource<int>)parameter;
                 try
                 {
                     _loop.Init(_engine.Libuv);

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

@@ -26,6 +26,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal
         private static readonly Action<ILogger, string, int, Exception> _connectionDisconnectedWrite;
         private static readonly Action<ILogger, string, long, Exception> _connectionHeadResponseBodyWrite;
         private static readonly Action<ILogger, Exception> _notAllConnectionsClosedGracefully;
+        private static readonly Action<ILogger, Exception> _notAllConnectionsAborted;
         private static readonly Action<ILogger, string, string, Exception> _connectionBadRequest;
         private static readonly Action<ILogger, string, Exception> _connectionReset;
         private static readonly Action<ILogger, string, Exception> _requestProcessingError;
@@ -54,6 +55,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal
             _connectionHeadResponseBodyWrite = LoggerMessage.Define<string, long>(LogLevel.Debug, 18, @"Connection id ""{ConnectionId}"" write of ""{count}"" body bytes to non-body HEAD response.");
             _connectionReset = LoggerMessage.Define<string>(LogLevel.Debug, 19, @"Connection id ""{ConnectionId}"" reset.");
             _requestProcessingError = LoggerMessage.Define<string>(LogLevel.Information, 20, @"Connection id ""{ConnectionId}"" request processing ended abnormally.");
+            _notAllConnectionsAborted = LoggerMessage.Define(LogLevel.Debug, 21, "Some connections failed to abort during server shutdown.");
         }
 
         public KestrelTrace(ILogger logger)
@@ -149,6 +151,11 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal
             _notAllConnectionsClosedGracefully(_logger, null);
         }
 
+        public virtual void NotAllConnectionsAborted()
+        {
+            _notAllConnectionsAborted(_logger, null);
+        }
+
         public void ConnectionBadRequest(string connectionId, BadHttpRequestException ex)
         {
             _connectionBadRequest(_logger, connectionId, ex.Message, ex);

test/shared/MockConnection.cs

@@ -7,6 +7,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Server.Kestrel;
 using Microsoft.AspNetCore.Server.Kestrel.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Http;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Testing
 {
@@ -24,9 +25,10 @@ namespace Microsoft.AspNetCore.Testing
             };
         }
 
-        public override void Abort(Exception error = null)
+        public override Task AbortAsync(Exception error = null)
         {
             RequestAbortedSource?.Cancel();
+            return TaskCache.CompletedTask;
         }
 
         public override void OnSocketClosed()