System.Net.HttpListener.RegisterForDisconnectNotification C# (CSharp) Method

        private void RegisterForDisconnectNotification(ulong connectionId, ref DisconnectAsyncResult disconnectResult)
        {
            Debug.Assert(disconnectResult == null);

            try
            {
                if (NetEventSource.IsEnabled) NetEventSource.Info(this, "Calling Interop.HttpApi.HttpWaitForDisconnect");

                DisconnectAsyncResult result = new DisconnectAsyncResult(this, connectionId);

                uint statusCode = Interop.HttpApi.HttpWaitForDisconnect(
                    _requestQueueHandle,
                    connectionId,
                    result.NativeOverlapped);

                if (NetEventSource.IsEnabled) NetEventSource.Info(this, "Call to Interop.HttpApi.HttpWaitForDisconnect returned:" + statusCode);

                if (statusCode == Interop.HttpApi.ERROR_SUCCESS ||
                    statusCode == Interop.HttpApi.ERROR_IO_PENDING)
                {
                    // Need to make sure it's going to get returned before adding it to the hash.  That way it'll be handled
                    // correctly in HandleAuthentication's finally.
                    disconnectResult = result;
                    DisconnectResults[connectionId] = disconnectResult;
                }

                if (statusCode == Interop.HttpApi.ERROR_SUCCESS && HttpListener.SkipIOCPCallbackOnSuccess)
                {
                    // IO operation completed synchronously - callback won't be called to signal completion.
                    result.IOCompleted(statusCode, 0, result.NativeOverlapped);
                }
            }
            catch (Win32Exception exception)
            {
                uint statusCode = (uint)exception.NativeErrorCode;
                if (NetEventSource.IsEnabled) NetEventSource.Info(this, "Call to Interop.HttpApi.HttpWaitForDisconnect threw, statusCode:" + statusCode);
            }
        }