DDS::LivelinessChangedStatus Struct Reference

::DDS::StatusKind::LIVELINESS_CHANGED_STATUS More...

#include <managed_subscription.h>

Public Attributes
System::Int32	alive_count
	The total count of currently alive DDS::DataWriter entities that write the DDS::Topic the DDS::DataReader reads.
System::Int32	not_alive_count
	The total count of currently not_alive DDS::DataWriter entities that write the DDS::Topic the DDS::DataReader reads.
System::Int32	alive_count_change
	The change in the alive_count since the last time the listener was called or the status was read.
System::Int32	not_alive_count_change
	The change in the not_alive_count since the last time the listener was called or the status was read.
InstanceHandle_t	last_publication_handle
	An instance handle to the last remote writer to change its liveliness.

Detailed Description

::DDS::StatusKind::LIVELINESS_CHANGED_STATUS

The DDS::DataReaderListener::on_liveliness_changed callback may be invoked for the following reasons:

• Liveliness is truly lost - a sample has not been received within the timeframe specified in DDS::LivelinessQosPolicy::lease_duration

• Liveliness is recovered after being lost.

• A new matching entity has been discovered.

• A QoS has changed such that a pair of matching entities are no longer matching (such as a change to the DDS::PartitionQosPolicy). In this case, RTI Connext will no longer keep track of the entities' liveliness. Furthermore:
  • If liveliness was maintained: DDS::LivelinessChangedStatus::alive_count will decrease and DDS::LivelinessChangedStatus::not_alive_count will remain the same.
  • If liveliness had been lost: DDS::LivelinessChangedStatus::alive_count will remain the same and DDS::LivelinessChangedStatus::not_alive_count will decrease.

Examples:

HelloWorld_subscriber.cpp.

Member Data Documentation

System::Int32 DDS::LivelinessChangedStatus::alive_count

The total count of currently alive DDS::DataWriter entities that write the DDS::Topic the DDS::DataReader reads.

System::Int32 DDS::LivelinessChangedStatus::not_alive_count

The total count of currently not_alive DDS::DataWriter entities that write the DDS::Topic the DDS::DataReader reads.

System::Int32 DDS::LivelinessChangedStatus::alive_count_change

The change in the alive_count since the last time the listener was called or the status was read.

System::Int32 DDS::LivelinessChangedStatus::not_alive_count_change

The change in the not_alive_count since the last time the listener was called or the status was read.

InstanceHandle_t DDS::LivelinessChangedStatus::last_publication_handle

An instance handle to the last remote writer to change its liveliness.