return to the Quality of Service (QoS) Parameters
The WRITER_DATA_LIFECYCLE policy controls the behavior of the DataWriter with regards to the lifecycle of the data-instances it manages, that is, the data-instances that have been either explicitly registered with the DataWriter using the register operations or implicitly by directly writing the data.
The autodispose_unregistered_instances flag controls the behavior when the DataWriter unregisters an instance by means of the unregister operations:
autodispose_unregistered_instances = TRUE causes the DataWriter to dispose the instance each time it is unregistered. The behavior is identical to explicitly calling one of the dispose operations on the instance prior to calling the unregister operation.autodispose_unregistered_instances = FALSE will not cause this automatic disposition upon unregistering. The application can still call one of the dispose operations prior to unregistering the instance and accomplish the same effect. There are consequences of disposing and unregistering instances.DataWriter automatically unregisters all data-instances it manages. Therefore the setting of the autodispose_unregistered_instances flag will determine whether instances are ultimately disposed when the DataWriter is deleted either directly by means of the Publisher::delete_datawriter operation or indirectly as a consequence of calling delete_contained_entities on the Publisher or the DomainParticipant that contains the DataWriter.
Source: DDS 1.4 Spec