TypeConsistencyEnforcementQosPolicy Class Reference

Defines the rules for determining whether the type used to publish a given topic is consistent with that used to subscribe to it. More...

Inheritance diagram for TypeConsistencyEnforcementQosPolicy:

Public Attributes
TypeConsistencyKind	kind
	Type consistency kind.
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

Defines the rules for determining whether the type used to publish a given topic is consistent with that used to subscribe to it.

This policy defines a type consistency kind, which allows applications to select from among a set of predetermined behaviors. The following consistency kinds are specified: com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.DISALLOW_TYPE_COERCION and com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.ALLOW_TYPE_COERCION.

The type-consistency-enforcement rules consist of two steps:

Step 1. If both the DataWriter and DataReader specify a TypeObject, it is considered first. If the DataReader allows type coercion, then its type must be assignable from the DataWriter’s type. If the DataReader does not allow type coercion, then its type must be structurally identical to the type of the DataWriter.

Step 2. If either the DataWriter or the DataReader does not provide a TypeObject definition, then the registered type names are examined. The DataReader’s and DataWriter’s registered type names must match exactly, as was true in RTI Connext releases prior to 5.0.0.

If either Step 1 or Step 2 fails, the Topics associated with the DataReader and DataWriter are considered to be inconsistent and the com.rti.dds.topic.InconsistentTopicStatus is updated.

The default enforcement kind is com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.ALLOW_TYPE_COERCION. However, when the middleware is introspecting the built-in topic data declaration of a remote DataReader in order to determine whether it can match with a local DataWriter, if it observes that no TypeConsistencyEnforcementQosPolicy value is provided (as would be the case when communicating with a Service implementation not in conformance with this specification), it assumes a kind of com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.DISALLOW_TYPE_COERCION.

For additional information on type consistency enforcement refer to the Addendum for Extensible Types and the OMG Extensible and Dynamic Topic Types for DDS Specification.

Entity:

com.rti.dds.subscription.DataReader

Properties:

RxO = N/A
Changeable = UNTIL ENABLE

Member Data Documentation

TypeConsistencyKind kind

Type consistency kind.

[default] com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.ALLOW_TYPE_COERCION