RTI Connext DDS Micro C++ API  Version 3.0.0
 All Classes Files Functions Variables Typedefs Enumerations Enumerator Groups
DDS_LatencyBudgetQosPolicy Struct 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_c_infrastructure.h>

List of all members.

Public Attributes

struct DDS_Duration_t duration
 Duration of the maximum acceptable delay.

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:
DDSTopic, DDSDataReader, DDSDataWriter
Status:
DDS_OFFERED_INCOMPATIBLE_QOS_STATUS, DDS_REQUESTED_INCOMPATIBLE_QOS_STATUS
Properties:
RxO = YES
Changeable = YES
See also:
DDS_PublishModeQosPolicy
DDSFlowController

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 DDS Micro can optimize its internal operation.

RTI Connext DDS Micro uses it in conjunction with DDS_ASYNCHRONOUS_PUBLISH_MODE_QOS DDSDataWriter instances associated with a DDS_EDF_FLOW_CONTROLLER_SCHED_POLICY DDSFlowController only. Together with the time of write, DDS_LatencyBudgetQosPolicy::duration determines the deadline of each individual sample. RTI Connext DDS Micro uses this information to prioritize the sending of asynchronously published data;

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

struct DDS_Duration_t DDS_LatencyBudgetQosPolicy::duration

Duration of the maximum acceptable delay.

[default] 0 (meaning minimize the delay)


RTI Connext DDS Micro C++ API Version 3.0.0 Copyright © Fri Mar 22 2019 Real-Time Innovations, Inc