Issues for Mailing list of the DDS for (Light Weight) CORBA Component Model 1.0 Finalization Task Force

List of issues (green=resolved, yellow=pending Board vote, red=unresolved)

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Issue 14060: Section 8.4.4 talks about threading, but this section is really under specified
Issue 15238: Let the user be able to instantiate one dds connector
Issue 15282: attributes as part of porttype do appear on port and mirrorport
Issue 15286: Layout issue test
Issue 15287: Make all arguments inout
Issue 15313: StateListenerControl:: is_filter_interpreted should be documented as optional
Issue 16603: Make topic_name changeable
Issue 17399: Name patterns should support underscores and scoping
Issue 18499: DDS_TopicBase connector lacks type_name

Issue 14060: Section 8.4.4 talks about threading, but this section is really under specified (dds4ccm-ftf)

Section 8.4.4 talks about threading, but this section is really under specified. It should be much clearer how threading works and what guarantees are given. 

No time to tackle it completely. In any case, will not change the already defined
interfaces.
Disposition: Deferred

Currently the DDS4CCM specification puts within the Typed module the extended ports, but also the dds connectors. The drawback of this approach is that when the user instantiates this templated module he gets both connectors, even when he is only interested in using one. We propose to move the DDS_State and DDS_Event to their own typed module so that the end user can instantiate just one of these connectors. This also makes it easier for a code generator to just generate the implementation for a specific connector, at this moment there is nothing in idl which can be used to determine whether the end user wants to use DDS_Event and/or DDS_State

No time to tackle it completely. Other solutions to minimize code generation are
under investigation.
Disposition: Deferred

This version of DDS4CCM adds the functionality to specify attributes as part of a porttype. This porttype can than be used by a component or connector as port or as mirrorport. The problem we see is that the attribute appears on the component/connector that uses the porttype as port or mirrorport. To our opinion the grammer should be more specific where the attribute appear, we propose to add the attribute by default to the component that uses the porttype as port, when the attribute has to appear on the component that uses the port as mirrorport we propose to define the attribute as:
mirror attribute my_attribute;

In case of DDS4CCM we see that the dds4ccm DDS_State connector gets 4 attributes which is what we want, but any user component using the porttype also gets a filter attribute

See page 35, line 35, 


 read_one_last returns the last sample of a given instanceThe targeted 

Missing dot after instance

In order to have the same memory management for the single data and datum operations, we propose to make all out arguments inout. This impacts:
Reader::read_one_last, info to inout
Getter::get_one, all arguments to inout

is_filter_interpreted has to be documented as optional, not just the filtering of out. 

This is because there is no required feature in the DDS core or part of the DDS DCPS specification which provides the INSTANCE_FILTERED_IN or INSTANCE_FILTERED_OUT status. Near as I can tell, this functionality comes as part of the DLRL layer "Selection_Listener" object (8.1.6.3.13).

In some systems they are receiving the topic_name after startup, at some moment they just get it and want to set it to a new value. We propose to remove topic_name, there seems to be no technical or structural reason not to allow the user to change the topic_name after the connector fragment has been initialized

The name patterns in the normative XML schema in Annex C do not support underscores. For detailed or lengthy profile names (especially including internal acronyms), using underscores significantly improves readability.


In addition, the elementName type is used both for the name and base_name attributes of the qosProfile type; however, the pattern for the elementName type does not support scoping, which is needed for inheritance between profiles in different libraries.


In order to address these, I propose that the elementName and topicNameFilter patterns be changed from:


"([a-zA-Z0-9 ])+"


to:


"^((::)?([a-zA-Z0-9_])+(::([a-zA-Z0-9_])+)*)$"

The latter is the currently commented-out pattern in the schema with the addition of the underscore.

When registering a topic to DDS we need to use an unique combination of domain id, topic name, and typename. Recent discussions revealed that there is no standard for a default typename, but also there could be reasons why an user don't want to use the default type_name. We propose to add to the DDS_TopicBase connector a type_name attribute, which when set, will be used as type_name, if not set, the DDS vendor default type_name will be used for the topic type