dds::core::policy::LatencyBudget 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...

#include <dds/core/policy/CorePolicy.hpp>

Public Member Functions
	LatencyBudget ()
	Creates a latency budget with zero duration.
	LatencyBudget (const dds::core::Duration &the_duration)
	Creates an instance with the specified duration.
LatencyBudget &	duration (const dds::core::Duration &the_duration)
	Sets the duration of the maximum acceptable delay.
const dds::core::Duration	duration () const
	Getter (see setter with the same name)

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:

dds::topic::Topic, dds::sub::DataReader, dds::pub::DataWriter

Status:

dds::core::status::StatusMask::offered_incompatible_qos(), dds::core::status::StatusMask::requested_incompatible_qos()

Properties:

RxO = YES
Changeable = YES

See Also

rti::core::policy::PublishMode

rti::pub::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 rti::core::policy::PublishModeKind_def::ASYNCHRONOUS dds::pub::DataWriter instances associated with a FlowControllerSchedulingPolicy_def::EARLIEST_DEADLINE_FIRST rti::pub::FlowController only. Together with the time of write, dds::core::policy::LatencyBudget::duration determines the deadline of each individual sample. RTI Connext uses this information to prioritize the sending of asynchronously published data; see rti::core::policy::AsynchronousPublisher.

Compatibility

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

Constructor & Destructor Documentation

dds::core::policy::LatencyBudget::LatencyBudget ( )

inline

Creates a latency budget with zero duration.

dds::core::policy::LatencyBudget::LatencyBudget ( const dds::core::Duration &  the_duration )

inlineexplicit

Creates an instance with the specified duration.

Member Function Documentation

LatencyBudget& dds::core::policy::LatencyBudget::duration ( const dds::core::Duration &  the_duration )

inline

Sets the duration of the maximum acceptable delay.

[default] 0 (meaning minimize the delay)

const dds::core::Duration dds::core::policy::LatencyBudget::duration ( ) const

inline

Getter (see setter with the same name)