Improve abort handling (#41263)

Author: HaoK

src/Servers/IIS/IIS/src/Core/IISHttpContext.IO.cs

@@ -164,6 +164,11 @@ private async Task WriteBody(bool flush = false)
                 var buffer = result.Buffer;
                 try
                 {
+                    if (_bodyOutput.Aborted)
+                    {
+                        break;
+                    }
+
                     if (!buffer.IsEmpty)
                     {
                         await AsyncIO!.WriteAsync(buffer);

src/Servers/IIS/IIS/src/Core/OutputProducer.cs

@@ -9,9 +9,10 @@ namespace Microsoft.AspNetCore.Server.IIS.Core;
 
 internal class OutputProducer
 {
-    // This locks access to _completed.
+    // This locks access to _completed and _aborted.
     private readonly object _contextLock = new object();
     private bool _completed;
+    private volatile bool _aborted;
 
     private readonly Pipe _pipe;
 
@@ -29,6 +30,8 @@ public OutputProducer(Pipe pipe)
 
     public PipeReader Reader => _pipe.Reader;
 
+    public bool Aborted => _aborted;
+
     public Task FlushAsync(CancellationToken cancellationToken)
     {
         _pipe.Reader.CancelPendingRead();
@@ -40,7 +43,7 @@ public void Complete()
     {
         lock (_contextLock)
         {
-            if (_completed)
+            if (_completed || _aborted)
             {
                 return;
             }
@@ -54,12 +57,12 @@ public void Abort()
     {
         lock (_contextLock)
         {
-            if (_completed)
+            if (_completed || _aborted)
             {
                 return;
             }
 
-            _completed = true;
+            _aborted = true;
 
             _pipe.Reader.CancelPendingRead();
             _pipe.Writer.Complete();
@@ -70,7 +73,7 @@ public Task WriteAsync(ReadOnlyMemory<byte> buffer, CancellationToken cancellati
     {
         lock (_contextLock)
         {
-            if (_completed)
+            if (_completed || _aborted)
             {
                 return Task.CompletedTask;
             }

src/Servers/IIS/IIS/test/IIS.Tests/ResponseAbortTests.cs

@@ -34,7 +34,6 @@ public async Task ClosesWithoutSendingAnything()
     }
 
     [ConditionalFact]
-    [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/31404")]
     public async Task ClosesAfterDataSent()
     {
         var bodyReceived = CreateTaskCompletionSource();