User Data QoS

This QosPolicy allows the application to attach additional information to a DomainParticipant, DataReader or DataWriter entity. This information is distributed with the BuiltinTopics.

Attributes

Value	Meaning	Concerns	RxO	Changeable
A sequence of octets: value	A sequence of octets that holds the application user data. By default, the sequence has length 0.	DomainParticipant, DataReader, DataWriter	No	Yes

This QosPolicy allows the application to attach additional information to a DomainParticipant, DataReader or DataWriter entity. This information is distributed with the Builtin Topics. An application that discovers a new Entity ofthe listed kind, can use this information to add additional functionality. The UserDataQosPolicy is changeable and updates of the Builtin Topic instance must be expected. Note that the Data Distribution Service is not aware of the real structure of the user data (the Data Distribution System handles it as an opaque type) and that the application is responsible for correct mapping on structural types for the specific platform.