Added operation cancel operation

src/Http/Http.Abstractions/src/PublicAPI.Unshipped.txt

@@ -1,4 +1,5 @@
 #nullable enable
+const Microsoft.AspNetCore.Http.StatusCodes.Status499ClientClosedRequest = 499 -> int
 Microsoft.AspNetCore.Http.HttpResults.EmptyHttpResult
 Microsoft.AspNetCore.Http.HttpResults.EmptyHttpResult.ExecuteAsync(Microsoft.AspNetCore.Http.HttpContext! httpContext) -> System.Threading.Tasks.Task!
 static Microsoft.AspNetCore.Http.HttpResults.EmptyHttpResult.Instance.get -> Microsoft.AspNetCore.Http.HttpResults.EmptyHttpResult!

src/Http/Http.Abstractions/src/StatusCodes.cs

@@ -283,6 +283,11 @@ public static class StatusCodes
     /// </summary>
     public const int Status451UnavailableForLegalReasons = 451;
 
+    /// <summary>
+    /// HTTP status code 499.
+    /// </summary>
+    public const int Status499ClientClosedRequest = 499;
+
     /// <summary>
     /// HTTP status code 500.
     /// </summary>

src/Middleware/Diagnostics/src/DeveloperExceptionPage/DeveloperExceptionPageMiddlewareImpl.cs

@@ -101,6 +101,19 @@ public async Task Invoke(HttpContext context)
         }
         catch (Exception ex)
         {
+
+            if (ex is OperationCanceledException && context.RequestAborted.IsCancellationRequested)
+            {
+                _logger.RequestAbortedException();
+
+                if (!context.Response.HasStarted)
+                {
+                    context.Response.StatusCode = 499;
+                }
+
+                return;
+            }
+
             _logger.UnhandledException(ex);
 
             if (context.Response.HasStarted)

src/Middleware/Diagnostics/src/DiagnosticsLoggerExtensions.cs

@@ -11,6 +11,9 @@ internal static partial class DiagnosticsLoggerExtensions
     [LoggerMessage(1, LogLevel.Error, "An unhandled exception has occurred while executing the request.", EventName = "UnhandledException")]
     public static partial void UnhandledException(this ILogger logger, Exception exception);
 
+    [LoggerMessage(4, LogLevel.Debug, "The request has aborted.", EventName = "RequestAborted")]
+    public static partial void RequestAbortedException(this ILogger logger);
+
     // ExceptionHandlerMiddleware
     [LoggerMessage(2, LogLevel.Warning, "The response has already started, the error handler will not be executed.", EventName = "ResponseStarted")]
     public static partial void ResponseStartedErrorHandler(this ILogger logger);

src/Middleware/Diagnostics/src/ExceptionHandler/ExceptionHandlerMiddlewareImpl.cs

@@ -112,6 +112,18 @@ static async Task Awaited(ExceptionHandlerMiddlewareImpl middleware, HttpContext
 
     private async Task HandleException(HttpContext context, ExceptionDispatchInfo edi)
     {
+        if (edi.SourceException is OperationCanceledException && context.RequestAborted.IsCancellationRequested)
+        {
+            _logger.RequestAbortedException();
+
+            if (!context.Response.HasStarted)
+            {
+                context.Response.StatusCode = 499;
+            }
+
+            return;
+        }
+
         _logger.UnhandledException(edi.SourceException);
         // We can't do anything if the response has already started, just abort.
         if (context.Response.HasStarted)

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

@@ -24,5 +24,8 @@ public static void ConnectionBadRequest(ILogger logger, string connectionId, Mic
 
         [LoggerMessage(4, LogLevel.Debug, @"Connection id ""{ConnectionId}"" bad request data: ""{message}""", EventName = nameof(ConnectionBadRequest))]
         private static partial void ConnectionBadRequest(ILogger logger, string connectionId, string message, Microsoft.AspNetCore.Http.BadHttpRequestException ex);
+
+        [LoggerMessage(5, LogLevel.Debug, "The request has aborted.", EventName = "RequestAborted")]
+        public static partial void RequestAborted(ILogger logger);
     }
 }

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

@@ -718,6 +718,10 @@ protected void ReportApplicationError(Exception ex)
 
         Log.ApplicationError(_logger, ((IHttpConnectionFeature)this).ConnectionId, ((IHttpRequestIdentifierFeature)this).TraceIdentifier, ex);
     }
+    protected void ReportRequestAborted()
+    {
+        Log.RequestAborted(_logger);
+    }
 
     public void PostCompletion(NativeMethods.REQUEST_NOTIFICATION_STATUS requestNotificationStatus)
     {

src/Servers/IIS/IIS/src/Core/IISHttpContextOfT.cs

@@ -4,6 +4,7 @@
 using System.Buffers;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting.Server;
+using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Logging;
 
 namespace Microsoft.AspNetCore.Server.IIS.Core;
@@ -19,7 +20,7 @@ public IISHttpContextOfT(MemoryPool<byte> memoryPool, IHttpApplication<TContext>
     {
         _application = application;
     }
-
+    
     public override async Task<bool> ProcessRequestAsync()
     {
         var context = default(TContext);
@@ -43,6 +44,18 @@ public override async Task<bool> ProcessRequestAsync()
             }
             catch (Exception ex)
             {
+                if (ex is OperationCanceledException && _requestAborted)
+                {
+                    ReportRequestAborted();
+
+                    if (!HasResponseStarted)
+                    {
+                        StatusCode = StatusCodes.Status499ClientClosedRequest;
+                    }
+
+                    return false;
+                }
+
                 ReportApplicationError(ex);
                 success = false;
             }

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

@@ -695,9 +695,20 @@ private async Task ProcessRequests<TContext>(IHttpApplication<TContext> applicat
                 // (DisposeContext logs StatusCode).
                 SetBadRequestState(ex);
                 ReportApplicationError(ex);
-            }
+            }            
             catch (Exception ex)
             {
+                if (ex is OperationCanceledException && RequestAborted.IsCancellationRequested)
+                {
+                    Log.RequestAborted();
+
+                    if (!HasResponseStarted)
+                    {
+                        StatusCode = 499;
+                    }
+
+                    return;
+                }
                 ReportApplicationError(ex);
             }
 

src/Servers/Kestrel/Core/src/Internal/Infrastructure/KestrelTrace.General.cs

@@ -64,6 +64,11 @@ public void Http3DisabledWithHttp1AndNoTls(EndPoint endPoint)
         GeneralLog.Http3DisabledWithHttp1AndNoTls(_generalLogger, endPoint);
     }
 
+    public void RequestAborted()
+    {
+        GeneralLog.RequestAbortedException(_generalLogger);
+    }
+
     private static partial class GeneralLog
     {
         [LoggerMessage(13, LogLevel.Error, @"Connection id ""{ConnectionId}"", Request id ""{TraceIdentifier}"": An unhandled exception was thrown by the application.", EventName = "ApplicationError")]
@@ -99,6 +104,9 @@ private static partial class GeneralLog
         [LoggerMessage(65, LogLevel.Warning, "HTTP/3 is not enabled for {Endpoint}. HTTP/3 requires TLS. Connections to this endpoint will use HTTP/1.1.", EventName = "Http3DisabledWithHttp1AndNoTls")]
         public static partial void Http3DisabledWithHttp1AndNoTls(ILogger logger, EndPoint endPoint);
 
+        [LoggerMessage(66, LogLevel.Debug, "The request has aborted.", EventName = "RequestAborted")]
+        public static partial void RequestAbortedException(ILogger logger);
+
         // Highest shared ID is 65. New consecutive IDs start at 66
     }
 }