LatencyBudgetQosPolicy Class Reference
[LATENCY_BUDGET]

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:

List of all members.

Public Attributes
final Duration_t	duration
	Duration of the maximum acceptable delay.

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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:

StatusKind.OFFERED_INCOMPATIBLE_QOS_STATUS, 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 PublishModeQosPolicyKind.ASYNCHRONOUS_PUBLISH_MODE_QOS com.rti.dds.publication.DataWriter instances associated with a 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'.

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Member Data Documentation

final Duration_t duration

Duration of the maximum acceptable delay.

[default] 0 (meaning minimize the delay)