public async Task Invoke(HttpContext context) { try { await _next(context); } catch (Exception ex) { _logger.LogError("An unhandled exception has occurred: " + ex.Message, ex); // We can't do anything if the response has already started, just abort. if (context.Response.HasStarted) { _logger.LogWarning("The response has already started, the error handler will not be executed."); throw; } PathString originalPath = context.Request.Path; if (_options.ExceptionHandlingPath.HasValue) { context.Request.Path = _options.ExceptionHandlingPath; } try { context.Response.Clear(); var exceptionHandlerFeature = new ExceptionHandlerFeature() { Error = ex, }; context.Features.Set<IExceptionHandlerFeature>(exceptionHandlerFeature); context.Response.StatusCode = 500; context.Response.OnStarting(_clearCacheHeadersDelegate, context.Response); await _options.ExceptionHandler(context); if (_diagnosticSource.IsEnabled("Microsoft.AspNet.Diagnostics.HandledException")) { _diagnosticSource.Write("Microsoft.AspNet.Diagnostics.HandledException", new { httpContext = context, exception = ex }); } // TODO: Optional re-throw? We'll re-throw the original exception by default if the error handler throws. return; } catch (Exception ex2) { // Suppress secondary exceptions, re-throw the original. _logger.LogError("An exception was thrown attempting to execute the error handler.", ex2); } finally { context.Request.Path = originalPath; } throw; // Re-throw the original if we couldn't handle it } }