LatencyBudgetQosPolicy Class Reference

Provides a hint as to the maximum acceptable delay from the time the data is written to the time it is received by the subscribing applications. More...

Inheritance diagram for LatencyBudgetQosPolicy:

Public Attributes
final Duration_t	duration
	Duration of the maximum acceptable delay.
Public Attributes inherited from QosPolicy
final QosPolicyId_t	id
	The ID of this QoS policy.
final String	policy_name
	The name of this QoS policy.

Additional Inherited Members
Public Member Functions inherited from Struct
abstract boolean	equals (Object obj)
abstract int	hashCode ()
String	toString ()
Protected Member Functions inherited from Struct
	Struct ()
abstract void	pull_from_nativeI (long native_status)
abstract void	push_to_nativeI (long native_status)

Detailed Description

Provides a hint as to the maximum acceptable delay from the time the data is written to the time it is received by the subscribing applications.

This policy is a hint to a DDS implementation; it can be used to change how it processes and sends data that has low latency requirements. The DDS specification does not mandate whether or how this policy is used.

Entity:

com.rti.dds.topic.Topic, com.rti.dds.subscription.DataReader, com.rti.dds.publication.DataWriter

Status:

com.rti.dds.infrastructure.StatusKind.StatusKind.OFFERED_INCOMPATIBLE_QOS_STATUS, com.rti.dds.infrastructure.StatusKind.StatusKind.REQUESTED_INCOMPATIBLE_QOS_STATUS

Properties:

RxO = YES
Changeable = YES

See Also

com.rti.dds.infrastructure.PublishModeQosPolicy

com.rti.dds.publication.FlowController

Usage

This policy provides a means for the application to indicate to the middleware the urgency of the data communication. By having a non-zero duration, RTI Connext can optimize its internal operation.

RTI Connext uses it in conjunction with com.rti.dds.infrastructure.PublishModeQosPolicyKind.PublishModeQosPolicyKind.ASYNCHRONOUS_PUBLISH_MODE_QOS com.rti.dds.publication.DataWriter instances associated with a com.rti.dds.publication.FlowControllerSchedulingPolicy.FlowControllerSchedulingPolicy.EDF_FLOW_CONTROLLER_SCHED_POLICY com.rti.dds.publication.FlowController only. Together with the time of write, com.rti.dds.infrastructure.LatencyBudgetQosPolicy.duration determines the deadline of each individual sample. RTI Connext uses this information to prioritize the sending of asynchronously published data; see com.rti.dds.infrastructure.AsynchronousPublisherQosPolicy.

Compatibility

The value offered is considered compatible with the value requested if and only if the inequality offered duration <= requested duration evaluates to 'TRUE'.

Member Data Documentation

final Duration_t duration

Duration of the maximum acceptable delay.

[default] 0 (meaning minimize the delay)