The DataWriter is an accessor to write data into a Domain. It is attached to the Publisher, a derived class specific to the associated Topic. The Publisher and the Topic associated to a DataWriter must be created with the same DomainParticipant. QoS policies on the associated Topic is retrieved and merged with DataWriter QoS (default or application provided) during creation.

Applicable QoS

Qos	Brief
USER_DATA	Sequence of data distributed by means of built-in topics
DURABILITY	Specifies if the data should 'outlive' their writing time
DEADLINE	Specifies the time duration for updating each instance periodically
LATENCY_BUDGET	Specifies the "urgency" of the data-communication
OWNERSHIP	Specifies multiple DataWriter objects to update the same instance
OWNERSHIP_STRENGTH	Specifies the value of the strength to arbitrate among DataWriters to update the same instance
LIVELINESS	Specifies the mechanism and parameters used by the application to determine the whether the Entity is 'alive'
RELIABILITY	Specifies the level of reliability offered/requested by the service
TRANSPORT_PRIORITY	Specifies the priority of the underlying transport used to send the data
LIFESPAN	Specifies the maximum duration of validity of the data written
DESTINATION_ORDER	Specifies the criteria to determine the logical order among changes made by Publisher entities of the same instances
HISTORY	Specifies the behaviour of the service when the value of an instance changes before communication to the DataReaders.
RESOURCE_LIMITS	Specifies the resources that can be consumed by the service
WRITER_DATA_LIFECYCLE	Specifies the behaviour of the DataWriter with respect to the lifecycle of the data-instances.

Default QoS Values

QoS	Attribute	Value
USER_DATA	value.length	0
DURABILITY	kind	VOLATILE
DEADLINE	period	DURATION_INFINITE
LATENCY_BUDGET	duration	0
OWNERSHIP	kind	SHARED
OWNERSHIP_STRENGTH	value	0
LIVELINESS	kind lease_duration	AUTOMATIC DURATION_INFINITE
RELIABILITY	kind max_blocking_time synchronous	RELIABLE 100 ms FALSE
TRANSPORT_PRIORITY	value	0
LIFESPAN	duration	DURATION_INFINITE
DESTINATION_ORDER	kind	BY_RECEPTION_TIMESTAMP
HISTORY	kind depth	KEEP_LAST 1
RESOURCE_LIMITS	max_samples max_instances max_samples_per_instance	LENGTH_UNLIMITED LENGTH_UNLIMITED LENGTH_UNLIMITED
WRITER_DATA_LIFECYCLE	autodispose_unregistered_instances	TRUE

Related Status Conditions

Status	Brief
LIVELINESS_LOST	Liveliness QoS set is not respected & DataReaders will consider DataWriters are no longer active
OFFERED_DEADLINE_MISSED	Deadline QoS set is not respected for a specific instance.
OFFERED_INCOMPATIBLE_QOS	QoS policies not compatible with the DataReaders
PUBLICATION_MATCHED	The DataWriter has found a DataReader that matches the Topic and Compatible QoS

Related Listeners

Listener	Brief
on_liveliness_lost	LiveLiness set by DataWriter is not respected
on_offered_deadline_missed	Deadline duration set by DataWriter is not respected
on_offered_incompatible_qos	QoS set by the DataWriter is not compatible with the DataReaders
on_publication_matched	The DataWriter has found a DataReader with a same Topic and Compatible QoS