System.Net.ListenerAsyncResult.IOCompleted C# (CSharp) Метод

        private static void IOCompleted(ListenerAsyncResult asyncResult, uint errorCode, uint numBytes)
        {
            object result = null;
            try
            {
                if (NetEventSource.IsEnabled) NetEventSource.Info(null, $"errorCode:[{errorCode}] numBytes:[{numBytes}]");

                if (errorCode != Interop.HttpApi.ERROR_SUCCESS &&
                    errorCode != Interop.HttpApi.ERROR_MORE_DATA)
                {
                    asyncResult.ErrorCode = (int)errorCode;
                    result = new HttpListenerException((int)errorCode);
                }
                else
                {
                    HttpListener httpWebListener = asyncResult.AsyncObject as HttpListener;
                    if (errorCode == Interop.HttpApi.ERROR_SUCCESS)
                    {
                        // at this point we have received an unmanaged HTTP_REQUEST and memoryBlob
                        // points to it we need to hook up our authentication handling code here.
                        bool stoleBlob = false;
                        try
                        {
                            if (httpWebListener.ValidateRequest(asyncResult._requestContext))
                            {
                                result = httpWebListener.HandleAuthentication(asyncResult._requestContext, out stoleBlob);
                            }
                        }
                        finally
                        {
                            if (stoleBlob)
                            {
                                // The request has been handed to the user, which means this code can't reuse the blob.  Reset it here.
                                asyncResult._requestContext = result == null ? new AsyncRequestContext(httpWebListener.RequestQueueBoundHandle, asyncResult) : null;
                            }
                            else
                            {
                                asyncResult._requestContext.Reset(httpWebListener.RequestQueueBoundHandle, 0, 0);
                            }
                        }
                    }
                    else
                    {
                        asyncResult._requestContext.Reset(httpWebListener.RequestQueueBoundHandle, asyncResult._requestContext.RequestBlob->RequestId, numBytes);
                    }

                    // We need to issue a new request, either because auth failed, or because our buffer was too small the first time.
                    if (result == null)
                    {
                        uint statusCode = asyncResult.QueueBeginGetContext();
                        if (statusCode != Interop.HttpApi.ERROR_SUCCESS &&
                            statusCode != Interop.HttpApi.ERROR_IO_PENDING)
                        {
                            // someother bad error, possible return values are:
                            // ERROR_INVALID_HANDLE, ERROR_INSUFFICIENT_BUFFER, ERROR_OPERATION_ABORTED
                            result = new HttpListenerException((int)statusCode);
                        }
                    }
                    if (result == null)
                    {
                        return;
                    }
                }

                // complete the async IO and invoke the callback
                if (NetEventSource.IsEnabled) NetEventSource.Info(null, "Calling Complete()");
            }
            catch (Exception exception) when (!ExceptionCheck.IsFatal(exception))
            {
                if (NetEventSource.IsEnabled) NetEventSource.Info(null, $"Caught exception: {exception}");
                result = exception;
            }
            asyncResult.InvokeCallback(result);
        }