add heartbeat-period and default to half reply timeout

third-party/realdds/src/dds-device-impl.cpp

@@ -85,7 +85,7 @@ dds_device::impl::impl( std::shared_ptr< dds_participant > const & participant,
  , _subscriber( std::make_shared< dds_subscriber >( participant ) )
  , _device_settings( device_settings( participant ) )
  , _reply_timeout_ms(
- _device_settings.nested( "control", "reply-timeout-ms" ).default_value< size_t >( 2000 ) )
+ _device_settings.nested( "control", "reply-timeout-ms" ).default_value< size_t >( 2500 ) )
 {
  create_control_writer();
  create_notifications_reader();
@@ -564,6 +564,9 @@ void dds_device::impl::create_control_writer()
  _control_writer = std::make_shared< dds_topic_writer >( topic );
  dds_topic_writer::qos wqos( eprosima::fastdds::dds::RELIABLE_RELIABILITY_QOS );
  wqos.history().depth = 10; // default is 1
+ // If our reply timeout is less than the heartbeat period, we could lose the control message!
+ // So we set a short heartbeat time at half the reply timeout...
+ wqos.reliable_writer_qos().times.heartbeatPeriod = _reply_timeout_ms / 2000.;
  _control_writer->override_qos_from_json( wqos, _device_settings.nested( "control" ) );
  _control_writer->run( wqos );
 }

third-party/realdds/src/dds-topic-writer.cpp

@@ -92,6 +92,8 @@ void dds_topic_writer::override_qos_from_json( qos & wqos, rsutils::json const &
  // Default values should be set before we're called:
  // All we do here is override those - if specified!
  override_reliability_qos_from_json( wqos.reliability(), qos_settings.nested( "reliability" ) );
+ if( wqos.reliability().kind == eprosima::fastdds::dds::RELIABLE_RELIABILITY_QOS )
+ qos_settings.nested( "heartbeat-period" ).get_ex( wqos.reliable_writer_qos().times.heartbeatPeriod );
  override_durability_qos_from_json( wqos.durability(), qos_settings.nested( "durability" ) );
  override_history_qos_from_json( wqos.history(), qos_settings.nested( "history" ) );
  override_liveliness_qos_from_json( wqos.liveliness(), qos_settings.nested( "liveliness" ) );