DDS_LivelinessQosPolicy Struct Reference

Determines the mechanism and parameters used by the application to determine whether an Entity is alive. More...

Data Fields
DDS_LivelinessQosPolicyKind	kind
	the kind of liveliness mechanism
struct DDS_Duration_t	lease_duration
	the duration of the liveliness lease

Detailed Description

Determines the mechanism and parameters used by the application to determine whether an Entity is alive.

The QoS defines the kind of liveliness (how liveliness is maintained) as well as a 'lease_duration' which specifies an interval for checking liveliness. The liveliness kind can be one of the following:

• AUTOMATIC
• MANUAL_BY_PARTICIPANT
• MANUAL_BY_TOPIC

The lease_duration indicates the maximum interval between liveliness indications from the publishing entity. If this period elapses with no indication from the publishing entity, then the entity is considered not alive.

Changes in liveliness are indicated to the application through status changes and the DataWriterListener.on_liveliness_lost and DataReaderListener.on_liveliness_changed listeners.

See also

DataReaderListener::on_liveliness_changed(DataReader the_reader, LivelinessChangedStatus DDS Status Structures) on_liveliness_changed

DataWriterListener::on_liveliness_lost(DataWriter writer, LivelinessLostStatus DDS Status Structures) on_liveliness_lost