void TryProcessClient(MqttClient connection, DateTime now) { try { if (!connection.IsRunning) { // The connection is already dead or just created so there is no need to check it. return; } if (connection.KeepAlivePeriod == 0) { // The keep alive feature is not used by the current connection. return; } if (connection.ChannelAdapter.IsReadingPacket) { // The connection is currently reading a (large) packet. So it is obviously // doing something and thus "connected". return; } // Values described here: [MQTT-3.1.2-24]. // If the client sends 5 sec. the server will allow up to 7.5 seconds. // If the client sends 1 sec. the server will allow up to 1.5 seconds. var maxDurationWithoutPacket = connection.KeepAlivePeriod * 1.5D; var secondsWithoutPackage = (now - connection.Statistics.LastPacketSentTimestamp).TotalSeconds; if (secondsWithoutPackage < maxDurationWithoutPacket) { // A packet was received before the timeout is affected. return; } _logger.Warning("Client '{0}': Did not receive any packet or keep alive signal.", connection.Id); // Execute the disconnection in background so that the keep alive monitor can continue // with checking other connections. // We do not need to wait for the task so no await is needed. // Also the internal state of the connection must be swapped to "Finalizing" because the // next iteration of the keep alive timer happens. var _ = connection.StopAsync(MqttDisconnectReasonCode.KeepAliveTimeout); } catch (Exception exception) { _logger.Error(exception, "Client {0}: Unhandled exception while checking keep alive timeouts.", connection.Id); } }
public Task DisconnectAsync() { return(_client.StopAsync(MqttDisconnectReasonCode.NormalDisconnection)); }