Return FINISH_REQUEST on request failure (#469)

Author: jkotalik

src/Microsoft.AspNetCore.Server.IISIntegration/Server/IISHttpContext.cs

@@ -805,7 +805,7 @@ private unsafe IISAwaitable ReadWebSocketsAsync(int length)
             return _readWebSocketsOperation;
         }
 
-        public abstract Task ProcessRequestAsync();
+        public abstract Task<bool> ProcessRequestAsync();
 
         public void OnStarting(Func<object, Task> callback, object state)
         {

src/Microsoft.AspNetCore.Server.IISIntegration/Server/IISHttpContextOfT.cs

@@ -19,9 +19,10 @@ public IISHttpContextOfT(PipeFactory pipeFactory, IHttpApplication<TContext> app
             _application = application;
         }
 
-        public override async Task ProcessRequestAsync()
+        public override async Task<bool> ProcessRequestAsync()
         {
             var context = default(TContext);
+            var success = true;
 
             try
             {
@@ -37,6 +38,7 @@ public override async Task ProcessRequestAsync()
             catch (Exception ex)
             {
                 ReportApplicationError(ex);
+                success = false;
             }
             finally
             {
@@ -61,6 +63,7 @@ public override async Task ProcessRequestAsync()
                 // If the request was aborted and no response was sent, there's no
                 // meaningful status code to log.
                 StatusCode = 0;
+                success = false;
             }
 
             try
@@ -71,6 +74,7 @@ public override async Task ProcessRequestAsync()
             {
                 // TODO Log this
                 _applicationException = _applicationException ?? ex;
+                success = false;
             }
             finally
             {
@@ -90,6 +94,7 @@ public override async Task ProcessRequestAsync()
                     await _readingTask;
                 }
             }
+            return success;
         }
     }
 }

src/Microsoft.AspNetCore.Server.IISIntegration/Server/IISHttpServer.cs

@@ -74,10 +74,10 @@ private static NativeMethods.REQUEST_NOTIFICATION_STATUS HandleRequest(IntPtr pH
             if (task.IsCompleted)
             {
                 context.Dispose();
-                return NativeMethods.REQUEST_NOTIFICATION_STATUS.RQ_NOTIFICATION_CONTINUE;
+                return ConvertRequestCompletionResults(task.Result);
             }
 
-            task.ContinueWith((t, state) => CompleteRequest((IISHttpContext)state), context);
+            task.ContinueWith((t, state) => CompleteRequest((IISHttpContext)state, t), context);
 
             return NativeMethods.REQUEST_NOTIFICATION_STATUS.RQ_NOTIFICATION_PENDING;
         }
@@ -96,15 +96,21 @@ private static NativeMethods.REQUEST_NOTIFICATION_STATUS OnAsyncCompletion(IntPt
             return NativeMethods.REQUEST_NOTIFICATION_STATUS.RQ_NOTIFICATION_PENDING;
         }
 
-        private static void CompleteRequest(IISHttpContext context)
+        private static void CompleteRequest(IISHttpContext context, Task<bool> completedTask)
         {
             // Post completion after completing the request to resume the state machine
-            context.PostCompletion(NativeMethods.REQUEST_NOTIFICATION_STATUS.RQ_NOTIFICATION_CONTINUE);
+            context.PostCompletion(ConvertRequestCompletionResults(completedTask.Result));
 
             // Dispose the context
             context.Dispose();
         }
 
+        private static NativeMethods.REQUEST_NOTIFICATION_STATUS ConvertRequestCompletionResults(bool success)
+        {
+            return success ? NativeMethods.REQUEST_NOTIFICATION_STATUS.RQ_NOTIFICATION_CONTINUE
+                                                     : NativeMethods.REQUEST_NOTIFICATION_STATUS.RQ_NOTIFICATION_FINISH_REQUEST;
+        }
+
         private class IISContextFactory<T> : IISContextFactory
         {
             private readonly IHttpApplication<T> _application;