Issues for Data Distribution Service 3 Revision Task Force

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

List options: All ; Open Issues only; or Closed Issues only

Issue 7964: no specific mention of interoperability in DDS 04-04-12 standard proposal
Issue 7965: DDS: DCPS generated interface FooTypeSupport
Issue 7966: DDS: DCPS - define the term "plain data structures"
Issue 7974: 2.1.3.20 WRITER_DATA_LIFECYCLE, itemized list, first bullet
Issue 7975: DDS 04-04-12 para. 2.1.1.1 Format and conventions
Issue 7976: DDS 04-04-12 Appendix B, C
Issue 8354: Typographical and grammatical errors
Issue 8355: Spelling inconsistencies between the PIM and IDL PSM
Issue 8358: Operation DataWriter::register
Issue 8359: (T#4) Typo in section 2.1.2.4.2.10 (write) and section 2.1.2.4.12 (dispose)
Issue 8360: Typo in section 2.1.2.5.2.5
Issue 8361: Default value for READER_DATA_LIFECYCLE
Issue 8362: Incorrect reference to USER_DATA on TopicQos
Issue 8363: No mention of DESTINATION_ORDER on DataWriterQos
Issue 8364: Formal parameter name improvement in IDL
Issue 8365: Spell fully the names for the DataReader operations
Issue 8366: Missing operations on DomainParticipantFactory
Issue 8367: T#18,24,) Missing operations and attributes
Issue 8368: (T#28) Typographical and grammatical errors
Issue 8369: (T#29) Missing operations to Topic class
Issue 8370: Formal parameter name change in operations of ContentFilteredTopic
Issue 8371: (T#30) Ambiguous description of TOPIC_DATA
Issue 8372: Confusing description of behavior of Publisher::set_default_datawriter_qos
Issue 8373: (T#33) Clarification in use of set_listener operation
Issue 8374: Missing description of DomainParticipant::get_domain_id
Issue 8375: (T#41) Default value for RELIABILITY max_blocking_time
Issue 8376: (T#42) Behavior when condition is attached to WaitSet multiple times
Issue 8377: Explicit mention of static DomainParticipantFactory::get_instance operation
Issue 8378: (T#45) Clarification of syntax of char constants within query expressions
Issue 8379: (T#52) Allow to explicitly refer to the default QoS
Issue 8380: (T#54) Performance improvement to WaitSet
Issue 8381: (T#55) Modification to how enumeration values are indicated in expressions
Issue 8382: (T#56) Return values of Waitset::detach_condition
Issue 8383: (T#57) Enable status when creating DomainParticipant
Issue 8384: Add autopurge_disposed_samples_delay to READER_DATA_LIFECYCLE QoS
Issue 8388: (R#106b) Parameter passing convention of Subscriber::get_datareaders
Issue 8389: (R#107) Missing Topic operations in IDL PSM
Issue 8390: (R#109) Unused types in IDL
Issue 8391: Incorrect field name for USER_DATA, TOPIC_DATA, and GROUP_DATA
Issue 8392: R#112) Incorrect SampleRejectedStatusKind constants
Issue 8393: R#114) Operations should not return void
Issue 8394: R#115) Destination order missing from PublicationBuiltinTopicData
Issue 8395: TransportPriority QoS range does not specify high/low priority values
Issue 8396: (R#119) Need lookup_instance method on reader and writer
Issue 8397: (R#120) Clarify use of DATAREADER_QOS_USE_TOPIC_QOS
Issue 8398: (R#122) Missing QoS dependencies in table
Issue 8399: Need an extra return code: ILLEGAL_OPERATION
Issue 8417: (R#124) Clarification on the behavior of dispose
Issue 8418: (R#125) Additional operations that can return RETCODE_TIMEOUT
Issue 8419: (R#127) Improve PSM mapping of BuiltinTopicKey_t
Issue 8420: Unspecified behavior of DataReader/DataWriter creation w/t mismatched Topic
Issue 8421: (R#130) Unspecified behavior of delete_datareader with outstanding loans
Issue 8422: (R#131) Clarify behavior of get_status_changes
Issue 8423: Incorrect reference to LIVELINESS_CHANGED in DataWriter::unregister
Issue 8424: (R#135) Add fields to PublicationMatchStatus and SubscriptionMatchStatus
Issue 8425: (R#138) Add instance handle to LivelinessChangedStatus
Issue 8426: (R#139) Rename *MatchStatus to *MatchedStatus
Issue 8427: (R#142) OWNERSHIP QoS policy should concern DataWriter and DataReader
Issue 8428: (R#145,146) Inconsistent description of Topic module in PIM
Issue 8429: (R#147) Inconsistent error code list in description of TypeSupport::registe
Issue 8430: (R#152) Extraneous WaitSet::wakeup
Issue 8431: (R#153) Ambiguous SampleRejectedStatus::last_reason field
Issue 8432: (R#154) Undefined behavior if resume_publications is never called
Issue 8531: DTD Error (mainTopic
Issue 8532: get_all-topic_names operation missing on figure 3-4
Issue 8533: Naming inconsistencies (IDL PSM vs. PIM) for ObjectHome operations
Issue 8534: Naming inconsistencies (IDL PSM vs. PIM) for Cache operation
Issue 8535: Bad cardinality on figure 3-4
Issue 8536: ReadOnly exception on clone operations
Issue 8537: Wrong definition for FooListener
Issue 8538: Typo CacheUsage instead of CacheAccess
Issue 8539: templateDef explanation contains some mistakes
Issue 8540: DlrlOid instead of DLRLOid in implied IDL
Issue 8541: Parameter wrongly named "object" in implied IDL
Issue 8542: Attach_Listener and detach_listener operations on ObjectHome are untyped
Issue 8543: Remove operations badly put on implied classes
Issue 8545: Behavior of DataReaderListener::on_data_available
Issue 8546: Inconsistent naming for status parameters in DataReader operations.
Issue 8547: (T#23) Syntax of partition strings
Issue 8548: Clarification of order preservation on reliable data reception
Issue 8549: (T#37) Clarification on the value of LENGTH_UNLIMITED constant
Issue 8550: (T#38) request-offered behavior for LATENCY_BUDGET
Issue 8551: (T#46) History when DataWriter is deleted
Issue 8552: (T#47) Should a topic returned by lookup_topicdescription be deleted
Issue 8553: (T#51) Identification of the writer of a sample
Issue 8554: (T#53) Cannot set listener mask when creating an entity
Issue 8555: (T#53) Cannot set listener mask when creating an entity
Issue 8556: (T#59) Deletion of disabled entities
Issue 8557: (T#60) Asynchronous write
Issue 8558: (T#61) Restrictive Handle definition
Issue 8559: (T#62, R#141) Unspecified TOPIC semantics
Issue 8560: (T#65) Missing get_current_time() function
Issue 8561: Read or take next instance, and others with an illegal instance_handle
Issue 8562: (T#69) Notification of unsupported QoS policies
Issue 8567: O#7966) Confusing terminology: "plain data structures"
Issue 8568: (R#104) Inconsistent naming of QueryCondition::get_query_arguments
Issue 8569: (R#115b) Incorrect description of QoS for built-in readers
Issue 8570: (R#117) No way to access Participant and Topic built-in topic data
Issue 8571: (R#126) Correction to DataWriter blocking behavior
Issue 8572: Clarify meaning of LivelinessChangedStatus fields and LIVELINESS le
Issue 8573: (R#133) Clarify meaning of LivelinessLost and DeadlineMissed
Issue 8574: (R#136) Additional operations allowed on disabled entities
Issue 8575: (R#144) Default value for DataWriter RELIABILITY QoS
Issue 8576: (R#150) Ambiguous description of create_topic behavior
Issue 8577: R#178) Unclear behavior of coherent changes when communication interrupted
Issue 8578: R#179) Built-in DataReaders should have TRANSIENT_LOCAL durability
Issue 8579: R#180) Clarify which entities appear as instances to built-in readers
Issue 8580: (R#181) Clarify listener and mask behavior with respect to built-in entitie
Issue 8581: R#182) Clarify mapping of PIM 'out' to PSM 'inout'
Issue 8582: (T#6) Inconsistent name: StatusKindMask
Issue 8775: Page: 2-8
Issue 9478: Inconsistencies between PIM and PSM in the prototype of get_qos() methods
Issue 9479: Inconsistent prototype for Publisher's get_default_datawriter_qos() method
Issue 9480: String sequence should be a parameter and not return value
Issue 9481: Mention of get_instance() operation on DomainParticipantFactory beingstatic
Issue 9482: Improper prototype for get_XXX_status()
Issue 9483: Inconsistent naming in SampleRejectedStatusKind
Issue 9484: OWNERSHIP_STRENGTH QoS is not a QoS on built-in Subscriber of DataReaders
Issue 9485: Consistency between RESOURCE_LIMITS QoS policies
Issue 9486: Blocking of write() call
Issue 9487: Clarify PARTITION QoS and its default value
Issue 9488: Typos in built-in topic table
Issue 9489: Naming of filter_parameters concerning ContentFilteredTopic
Issue 9490: Incorect prototype for FooDataWriter method register_instance_w_timestamp()
Issue 9491: Compatible versus consistency when talking about QosPolicy
Issue 9492: Incorrect mention of INCONSISTENT_POLICY status
Issue 9493: Typos in QoS sections
Issue 9494: Typos in PIM sections
Issue 9495: Clarify ownership with same-strength writers
Issue 9496: Should write() block when out of instance resources?
Issue 9497: Description of set_default_XXX_qos()
Issue 9498: Naming consistencies in match statuses
Issue 9499: delete_contained_entities() on the Subscriber
Issue 9500: Return of get_matched_XXX_data()
Issue 9501: Need INVALID_QOS_POLICY_ID
Issue 9502: Clarify valid handle when calling write()
Issue 9503: Operation dispose_w_timestamp() should be callable on unregistered instance
Issue 9504: Behavior of dispose with regards to DURABILITY QoS
Issue 9505: Typo in copy_from_topic_qos
Issue 9506: Order of parameters incorrect in PSM
Issue 9507: Typo in get_discovered_participant_data
Issue 9508: Operation wait() on a WaitSet should return TIMEOUT
Issue 9509: Example in 2.1.4.4.2 not quite correct
Issue 9510: Non intuitive constant names
Issue 9511: Corrections to Figure 2-19
Issue 9516: Simplify Relation Management
Issue 9517: Cache and CacheAccess should have a common parent
Issue 9518: Object notification in manual update mode required
Issue 9519: ObjectExtent and ObjectModifier can be removed
Issue 9520: Introduce the concept of cloning contracts consistently in specification
Issue 9521: Object State Transitions of Figure 3-5 and 3-6 should be corrected
Issue 9522: Add Iterators to Collection types
Issue 9523: Harmonize Collection definitions in PIM and PSM
Issue 9524: Add the Set as a supported Collection type
Issue 9525: Make the ObjectFilter and the ObjectQuery separate Selection Criterions
Issue 9526: Add a static initializer operation to the CacheFactory
Issue 9527: Make update rounds uninterruptable
Issue 9528: Remove lock/unlock due to overlap with updates_enabled
Issue 9529: Add Listener callbacks for changes in the update mode
Issue 9530: Representation of OID should be vendor specific
Issue 9531: define both the Topic name and the Topic type_name separately
Issue 9532: Merge find_object with find_object_in_access
Issue 9533: Clarify which Exceptions exist in DLRL and when to throw them
Issue 9534: Support sequences of primitive types in DLRL Objects
Issue 9535: manual mapping key-fields of registered objects may not be changed
Issue 9536: Specification does not state how to instantiate an ObjectHome
Issue 9537: Raise PreconditionNotMet when changing filter expression on registered Obje
Issue 9538: PIM description of "get_domain_id" method is missing
Issue 9539: PIM and PSM contradicting wrt "get_sample_lost_status" operation
Issue 9540: Small naming inconsistentcies between PIM and PSM
Issue 9541: Unlimited setting for Resource limits not clearly explained
Issue 9542: Inconsistent PIM/PSM for RETCODE_ILLEGAL_OPERATION
Issue 9543: Resetting of the statusflag during a listener callback
Issue 9544: Incorrect description of enable precondition
Issue 9545: invalid reference to delete_datareader
Issue 9546: Clarify the meaning of locally
Issue 9548: Missing autopurge_disposed_sample_delay
Issue 9549: Illegal return value register_instance
Issue 9550: Typo in section 2.1.2.5.1
Issue 9551: Extended visibility of instance state changes
Issue 9552: Clarify notification of ownership change
Issue 9553: read/take_next_instance()
Issue 9554: instance resource can be reclaimed in READER_DATA_LIFECYCLE QoS section
Issue 9555: String sequence should be a parameter and not return value

Issue 7964: no specific mention of interoperability in DDS 04-04-12 standard proposal (data-distribution-rtf)

I find no specific mention of interoperability in the DDS 04-04-12
standard proposal.


It should be clarified whether the standard is intended to address
interoperability, and if so, under what exact conditions (e.g., is it
safe to assume that if the DCPS IDL PSM is implemented by IIOP based
CORBA ORBs then it will be possible to interoperate?)

RTF Comments:
The DDS specification addresses only inter-vendor portability. The specification defines the API and behavior. There is an on-going effort at OMG to address interoperability.  In the meantime implementations could be built on top of IIOP. However, given that the DDS Entities are intended to be local communication endpoints and not and not references to the use of IIOP would not be sufficient to achieve interoperability as it IIOP does not address how to represent the QoS, discovery information, and other behaviors necessary to implement DDS. In addition the DDS specification was designed to be implementable on top of connectionless unreliable protocols such as IP multicast and IIOP does not offer direct facilities to do that.

Nature: Enhancement


Summary:


Document 04-04-12 para. 2.2.3 near end
In the implied IDL interface FooTypeSupport for a user type Foo,
there is an operation


  DDS::ReturnCode_t register_type(in DDS::DomainParticipant
                                    participant,
                                  in string type_name);


IMHO the type_name argument is superfluous:
The generated stub code can fill it in automatically ("Foo").

RTF Comments:
The type name is not superfluous; see section 2.1.2.3.6.1. In some applications, it may be desirable to register the same physical type multiple times (with different participants or the same participant) under different names.
However, given that different Topics can already be created that use the same type, and given that typdefs can be used to create new type names. A good argument could be made that there is limited use for the added functionality provided by the type-name parameter. A use case could perhaps be used to clarify the need.
As a compromise, the standard could be changed to state that a nil type name is permissible, in which case the default name will be used. Alternatively, the FooTypeSupport class could get an additional method get_type_name() that returns the default type name. 

OMG document 04-04-12 para. 2.1.1.2.2 Overall Conceptual Model
pg. 2-7 states:


  At the DCPS level, data types represent information that is sent
  atomically. For performance reasons, only plain data structures
  are handled by this level.


Please define the term "plain data structures".

* The setting 'autodispose_unregistered_instances = FALSE' causes the
     DataWriter [...] 


Change FALSE to TRUE. 

The table format used for documenting classes contains an
"attributes" and an "operations" section.


However, in order for applications to be portable across
implementations of the DDS spec, it would be desirable to add
a "constructors" section that explicitly states those constructors
that take one or more arguments (i.e. non-default constructors.)

Filters and Queries are not compile-time checked and are too
 heavy


The 04-04-12 DDS document proposes a subset of SQL for defining filters
andqueries.


The filter/query expressions are passed into the corresponding methods
as type "string".


First, this means that conforming implementations need to provide an SQL
expression parser/evaluator - a fairly complex piece of software.
Second, since the expressions are given as strings, checking them at
compile time is not straight-forward.


We request the Revision Task Force to reconsider this design decision
in favor of less heavyweight approaches that allow for compile-time
checks.

RTF Comments:
The DDS RTF agrees in principle that it would be a good idea. However we were not able to come up with a suitable proposal that addresses the need for doing the content-filter also at the DataWriter side.
Therefore the DDS RTF is recommending this issue is postponed to a future RTF where more implementation experience may be available to suggest the best approach.
Resolution:
No change to the specification.

The specification contains a number of misspellings and other minor typographical and grammatical errors.

The typographical and grammatical errors shall be corrected.
Revised Text:
Location	Original Incorrect Text	Corrected Text
2.1.2, fig. 2-4	"Topic Module"	"Topic-Definition Module"
2.1.2.2.2	create_participant parameter "domainId"	create_participant parameter "domain_id"
2.1.2.2.2	lookup_participant parameter "domainId"	lookup_participant parameter "domain_id"
2.1.2.2.2.1	"domainId"	"domain_id"
2.1.2.2.2.4	"domainId" (two occurrences)	"domain_id" (two occurrences)
		
2.1.2.3.7, pg. 2-39	"…for a hypothetical application named "Foo"…"	"…for a hypothetical application data type named "Foo"…"
2.1.2.4.1.15	"…get_default_datawriter_qos will match the set of valuesspecified on the last successful call to get_default_datawriter_qos…"	"…get_default_datawriter_qos will match the set of valuesspecified on the last successful call to set_default_datawriter_qos…"
2.1.2.5, fig. 2-10	SampleInfo attribute "instance_rank"	SampleInfo attribute "sample_rank"
2.1.2.5.1, fig. 2-11	transition from NO_WRITERS to ALIVE "…=++"	transition from NO_WRITERS to ALIVE "…++"
2.1.2.5.1, pg. 2-57	"time-stamp"	"timestamp"
2.1.2.5.1, pg. 2-59, 2nd to last para.	"…snapshot of view_state…"	"…snapshot of the view_state…"
2.1.2.5.1, pg. 2-61, 4th para.	"…multiple DataReader."	"…multiple DataReaders."
2.1.2.5.1, pg. 2-61, list item (1)	"…list of DataReader…" (two occurrences)	"…list of DataReaders…" (two occurrences)
2.1.2.5.1, pg. 2-61	"…acrossDataWriter entities." (two occurrences)	"…acrossDataReader entities." (two occurrences)
2.1.2.5.2.7	"…multiple DataReader…"	"…multiple DataReaders…"
2.1.3, pg. 2-92	"…ability to: specify and receive coherent changes see the relative order of changes."	"…ability to specify and receive coherent changes and to see the relative order of changes."
2.1.3, pg. 2-98	"time-stamp"	"timestamp"
2.1.3, pg. 2-101, autopurge_ nowriter_ samples_ delay row	"…information regarding instances that have the view_state NOT_ALIVE_NO_WRITERS."	"…information regarding instances that have the instance_state NOT_ALIVE_NO_WRITERS."
2.1.3.6	"TIME_BASED_PERIOD"	"TIME_BASED_FILTER"
2.1.3.17 last para.	"compatible" (two occurrences)	"consistent" (two occurrences)
2.1.3.18 last para.	"compatible" (two occurrences)	"consistent" (two occurrences)
2.1.3.20 itemized list, first bullet	"The setting 'autodispose_unregistered_ instances = FALSE' causes the DataWriter…"	"The setting 'autodispose_unregistered_ instances = TRUE' causes the DataWriter…"
2.1.3.21, para. 4	"… view_state = NOT_ALIVE_NO_WRITERS…"	"… instance_state = NOT_ALIVE_NO_WRITERS…"
2.1.4.1 Requested-Incom-patible-Qos-Status:: total_count row	"Total cumulative count the concerned DataReader discovered a DataWriter…"	"Total cumulative number of times the concerned DataReader discovered a DataWriter…"
2.1.4.4, before fig. 2-19	Reference to figure 2-18	Reference to figure 2-19
2.1.5 para. 3	"get_datareader"	"lookup_datareader"
2.2.3	const long DURATION_INFINITY_SEC = 0x7ffffff;const unsigned long DURATION_INFINITY_NSEC = 0x7ffffff;	const long DURATION_INFINITY_SEC = 0x7fffffff;const unsigned long DURATION_INFINITY_NSEC = 0x7fffffff;
2.2.3	interface DomainParticipantFactory {  DomainParticipant  create_participant(    in DomainId_t    domainId,    in DomainParticipantQos    qos,    in DomainParticipantListener    a_listener);  …  DomainParticipant   lookup_participant(  in DomainId_t domainId);  …	interface DomainParticipantFactory {  DomainParticipant  create_participant(    in DomainId_t    domain_id,    in DomainParticipantQos    qos,    in DomainParticipantListener    a_listener);  …  DomainParticipant   lookup_participant(  in DomainId_t domain_id);  …

In a number of instances, there are minor inconsistencies in spelling and naming between the specification's platform-independent model (PIM) and the included IDL platform-specific model (PSM).
Resolution:
In each case, the most descriptive term of the two options was chosen and the other was conformed to it.

The method DataWriter::register conflicts with the C++ 'register' keyword.
Resolution:
Replace register and unregister by register_instance and unregister_instance
Replace register_w_timestamp  and unregister_w_timestamp by register_instance_w_timestamp and unregister_instance_w_timestamp

Since the revisions are straightforward, here only the figures,tables and paragraphs are indicated which are affected by the above indicated change.
- update figures 2-8, 2-9,  accordingly
- update tables in paragraph 2.1.2.4.2 accordingly
- update text in paragraphs 2.1.2.4.2.5/6/7/8, 2.1.3.20 and 2.1.3.22.3 accordingly
- update IDL in paragraph 2.2.3 accordingly

Summary:
In par. 2.1.2.4.2.10 (write) and par. 2.1.2.4.12 (dispose) the specification does not specify an error code in case the specified handle is valid but does not correspond to the given instance (the key value must match), and neither for the case that the specified handle is invalid.
Resolution:
Specify that in general, the result is unspecified, but that depending on vendor-specific implementations, the resulting error-code is 'PRECONDITION_NOT_MET' if a wrong instance (i.e. with a wrong key-value) is provided and that the resulting error-code is 'BAD_PARAMETER' if a bad handle is provided
Revised Text:
Add the following text to the end of 2.1.2.4.2.10 (write)
In case the provided handle is valid but does not correspond to the given instance, the resulting error-code of the operation will be 'PRECONDITION_NOT_MET'. In case the handle is invalid, the behavior is in general unspecified, but if detectable by a DDS-implementation, the returned error-code will be 'BAD_PARAMETER'.
Replace in 2.1.2.4.2.12 (dispose),  the text "Possible error codes returned in addition to the standard ones: PRECONDITION_NOT_MET" by the following text:
In case the provided handle is valid but does not correspond to the given instance, the resulting error-code of the operation will be 'PRECONDITION_NOT_MET'. In case the handle is invalid, the behavior is in general unspecified, but if detectable by a DDS-implementation, the returned error-code will be 'BAD_PARAMETER'.

In section 2.1.2.5.2.5. (create_datareader) the special  value DATAWRITER_QOS_USE_TOPIC_QOS is mistakenly being used instead of DATAREADER_QOS_USE_TOPIC_QOS.
Resolution:
Replace the wrong text with the correct version.
Revised Text:
In 2.1.2.5.2.5 (create-datareader) replace the text "The special value DATAWRITER_QOS_USE_TOPIC_QOS" with "The special value "DATAREADER_QOS_USE_TOPIC_QOS

Section 2.1.3. (Supported QoS) the default value of the duration attribute of the READER_DATA_LIFECYCLE QoS is specified as "unlimited"..
Resolution:
Replace "unlimited" by "infinite", which in general is used in relation with durations.
Revised Text:
In the QoS-table of paragraph 2.1.3, replace the text "By default, unlimited" as belongs to the READER_DATA_LIFECYCLE QoS by the text "By default, infinite".

The table in section 2.1.3. (Supported QoS) wrongful specifies that USER_DATA concerns Topic.
Resolution:
'Topic' should be removed from the 'concerns' column.
Revised Text:
In the table in section 2.1.3 (Supported QoS), remove from the "USER-DATA" row, and from the "Concerns" column, the word 'Topic'.

In the table in section 2.1.3. (Supported QoS) the DESTINATION_ORDER QoS does not mention the 'datawriter' as concerned entity.
Resolution:
Add  DataWriter to the 'concerns' column.
Revised Text:
In the table in section 2.1.3 (Supported QoS), add to the "DESTINATION_ORDER" column and the "Concerns" row, the word 'DataWriter'.

In the IDL specification of section 2.2.3, the first parameter of the 'register_type' method is called 'domain' instead of 'participant' (as it is called elsewhere, like in the table of secion 2.1.2.3.6.
Resolution:
Change the parameter name to 'participant' in the typesupport::register_type IDL.
Revised Text:
In Chapter 2.2.3 (IDL specification), change the register_type parameter called 'domain' into 'participant'.

In some class diagrams, generic operations are indicated using '_xxx_' in their names instead of fully specifying all the real operations and also some operations are missing.
Resolution:
- add the missing operations for the dataReader
- explicitly mention all operations for the dataReader
Revised Text:
In the class diagram Fig. 2-8 on page 2-39:
- add missing operations "read_w_condition", "take_w_condition" and "return_loan".
- rename "read_xxx_w_conditon" into "read_next_w_condition".
- rename "take_xxx_w_condition" into "take_next_w_condition"

The class DomainParticipantFactory in figure 2-6 section 2.1.2.2. (Domain Module) misses the operations set_default_participant_qos and get_default_participant_qos..
Resolution:
Add the missing operations.
Revised Text:
In the class diagram Fig. 2-6 of section 2.1.2.2 (Domain Module), add the operations 'set_default_participant_qos' and 'get_default_participant_qos'.

In some of the figures some operations are missing.
Resolution:
The missing operations shall be added.
Revised Text:
Location	Missing operation
2.1.2.5, fig. 2-10	delete_contained_entities()
2.1.2.2, fig. 2-6	set_default_publisher_qos()get_default_publisher_qos()set_default_subscriber_qos()get_default_subscriber_qos()set_default_topic_qos()get_default_topic_qos()

The specification contains a number of misspellings and other minor typographical and grammatical errors.
Resolution:
The typographical and grammatical errors shall be corrected.
Revised Text:
Location	Original Incorrect Text	Corrected Text
2.1.2.1, fig. 2-5	"Status" (the class name)	"Status"
2.1.2.2, fig. 2-6	"domainId" 	"domain_id"

In the DCPS PSM the Topic class does not specify the methods set_qos, get_qos, set_listener and get_listener.
Resolution:
The methods set_qos, get_qos, set_listener and get_listener shall be added to the IDL description of the Topic class.
Revised Text:
In the IDL in 2.2.3:

interface Topic : Entity, TopicDescription {
    …
    ReturnCode_t set_qos(
        in TopicQos qos);
    void get_qos(
        inout TopicQos qos);
    ReturnCode_t set_listener(
        in TopicListener a_listener,
        in StatusMask mask);
    TopicListener get_listener();
    ReturnCode_t get_inconsistent_topic_status(
        inout: InconsistentTopicStatus);
    …
};

Some of the formal parameter names of ContentFilteredTopic methods are vague.
Resolution:
The names shall be changed into more distinct names.
Revised Text:

Location	Original incorrect name	Corrected name
section 2.1.2.2.1, create_contentfilteredtopic	expression_parameters	filter_parameters
section 2.1.2.2.1.7	topic_name	related_topic
section 2.1.2.2.1.7	expression_parameters	filter_parameters
section 2.1.2.3.3, get_expression_parameters	expression_parameters	filter_parameters
section 2.1.2.3.3, set_expression_parameters	expression_parameters	filter_parameters

The last part of the description states: "They both concern Topic, DataWriter and DataReader…"although that furter in the text is described that TOPIC_DATA is only applicable for Topics it would be better to remove this part of the description.
Resolution:
The last section of paragraph 2.1.3.2 shall be removed.
Revised Text:
The text: "This QoS is very similar in intent to USER_DATA……primarily on the DataReader/DataWriter." shall be removed.

The description of the Publisher method set_default_datawriter_qos describes the use in case the qos was not explicitly specified at the create_datawriter operation. However, specifying the qos policy at the create_datawriter is not optional, it should state in case the default is used.
Resolution:
The description shall be modified to clarify the use-case of using the defaults.
Revised Text:

In section 2.1.2.4.1.15:
Replace "in the case where the QoS policies are not explicitly specified"  with "in the case where the QoS policies are defaulted

The description of the Entity method set_listener does not describe the result of this method if called with the value of the listener parameter set to NIL.
the value NIL is passed for the listener parameter. Chapter 2.1.2.1.1.3 (set_listener): Explicitly state that passing the value NIL for the listener is valid and clears the listener.
Resolution:
The description of this use-case shall be added to the description.
Revised Text:
Only one listener can be attached to each Entity. If a listener was already set, the operation set_listener will replace it with the new one. Consequently if the value 'nil' is passed for the listener parameter to this method any existing listener will be removed. 

In the class description of the DomainParticipant the description of the attribute domain_id is missing
Resolution:
The attribute domain_id shall be added to the table in 2.1.2.2.1
The description of attribute domain_id shall be added as section 2.1.2.2.1.26
Revised Text:
1.1.2.2.1.26	 domain_id
The domain_id identifies the Domain of the DomainParticipant. At creation the DomainParticipant is associated to this domain

The default value of the RELIABILITY qos policy attribute max_blocking_time is not specified.
Resolution:
The default value shall be specified an arbitrary value greater then zero to avoid that writers will encounter timeouts on acceptable temporary buffer saturations and the value should not be too big since real-time behavior would expect that anything causing writers to block would not sustain for a long time.
Revised Text:
In section 2.1.3:
Add to the description of the RELIABILITY QosPolicy value RELIABLE in the QosPolicy table the text:
"The default max_blocking_time=100ms.

It is not clearly defined what should happen when the same condition is attached to the same WaitSet multiple times.
Resolution:
Explicitly state that this has no effect: subsequent attachments of the same Condition will be ignored.
Revised Text:
Add a small piece of text to section 2.1.2.1.6.1, which explains that adding a Condition that is already attached to that WaitSet has no effect.

The get_instance method is mentioned in the PIM, but not in the IDL PSM. 
Resolution:
Explicitly state that this is a static method and that it is therefore not specified in IDL. 
Revised Text:
Add a piece of text to section 2.1.2.2.2.3 explaining that the get_instance method is a static method implemented as a native language construction, and can therefore not be expressed in IDL.
Add the "static" keyword before the get_instance method mentioned in the table of section 2.1.2.2.2.
Add piece of text in section 2.2.2 (right after the introduction of default constructors for WaitSet and GuardCondition) which explains that the DomainParticipantFactory has a static method called get_instance in the native classes that implement it.

It is not clear how the value of a char constant should be expressed in a query expression.
Resolution:
Clarify that a char constant in a query expression must be places between single quotes.
Revised Text:
Add a bullet to Appendix B in the section "Token expression" where the char constant is introduced and where is explained how it should be defined (between single quotes, just like the tring).
Keep Appendix C inline with this as well

It would be nice to be able to use the "<item>_QOS_DEFAULT" constant in both the set_default_<item>_qos method of its factory and in its set_qos method as well.
Resolution:
Explicitly allow that passing the default qos constant ("<item>_QOS_DEFAULT") to the "set_default_<item>_qos" method in its factory will reset the default qos value for the item to its initial factory default state.
Also state that using the "<item>_QOS_DEFAULT" constant in the set_qos method of an item will change the qos of that item according to the current default of its container entity at the time the call is made.
Revised Text:
For each "set_default_<item>_qos" method in each factory, add the fact that the "<item>_QOS_DEFAULT" constant may be used to revert it back to its factory settings. This impacts sections 2.1.2.2.1.20, 2.1.2.2.1.22, 2.1.2.2.1.24, 2.1.2.4.1.14 and 2.1.2.5.2.15.
For each set_qos method in each entity, state that the corresponding "<item>_QOS_DEFAULT" constant may be used to change the qos of the item according to the current default of its container entity at the time the call is made, provided that this does not change any immutable qos once the entity is enabled. This impacts only section 2.1.2.1.1.1, since the set_qos method explanations are not repeated in the descriptions for every entity specialization.

The get_conditions and wait methods of the WaitSet pass the Conditions in which the user is interested back to the application as out-parameters. This causes unnecessary memory allocations each time a WaitSet is used for that purpose. 
Resolution:
Make the WaitSet result sequence of the inout type for performance reasons, especially because the application is aware of the desired (worst-case) length. The user is then able to recycle these sequences every time.
Revised Text:
In the table in section 2.1.2.1.6 change the parameter types of the Condition Sequence from out  to inout. Explain in sections 2.1.2.1.6.3 and 2.1.2.1.6.4 that the user can either pre-allocate the sequence and force the middleware to overwrite its contents, or to not to pre-allocate and let the middleware allocate the memory for him. 
Also change the IDL definition for both methods in section 2.2.3.

Appendix B describes an enumeration value as a name::value, during a telephone conference (in a hurry) this is decided to solve ambiguity between attribute names and enumeration labels. The description states that the name specifies the field, that should be the enumeration type. In addition the enumeration type should be a fully specified type name including its scope. This is a lot to specify in a query expression especially because within a query expression the enumeration value is always related to a field that already identifies the type. In addition in SQL enumeration labels are represented as string literals i.e. the values are put between single quotes.
Resolution:
Treat enumeration values as string literals and place them between single quotes instead of using a scope operator.
Revised Text:
In Appendix B in the section "Token expression" where the ENUMERATEDVALUE is introduced, replace the sentence that states that "A double colon '::' is used to separate the name of the enumeration from that of the field." with a sentence that states that enumeration labels should be treated as string literals and should therefore be put between single quotes. In the next sentence, remove the part which states that the name of the enumeration should correspond to the name specified in the IDL definition. (But keep the part of the sentence that states that the name of the value should correspond to the names of the labels.
Keep Appendix C in line with this as well.

section 2.1.2.1.6.2. (Waitset::detach_condition) describes to return BAD_PARAMETER if the given condition is not attached to the waitset. It would be more appropriate to return PRECONDITION_NOT_MET.

Resolution:
Change the return-code
Revised Text:
In section 2.1.2.1.6.2 (Waitset::detach_condition), change all mentioning of BAD_PARAMETER into PRECONDITION_NOT_MET.

DomainParticipants , being entities, can be both enabled or disabled.. Because the DomainParticipantFactory is not an entity and therefore does not have a QoS, it doesn't support a Factory QosPolicy which specifies how to create a DomainParticipant (either enabled or disabled). 
Resolution:
Add a DomainParticipantFactoryQos policy to the DomainParticipantFactory, and add the operation set_qos() and get_qos() to the DomainParticipantFactory class. (However, do not make the DomainParticipantFactory an Entity itself!)
Revised Text:
In section 2.1.2.2.2, add the get_qos and set_qos methods to the table. Create two new sections (2.1.2.2.2.7 and 2.1.2.2.2.8), which explain the semantics of these get_qos and set_qos. Also explain that the fact that although the DomainParticipantFactory has a qos, it is not an Entity, since it does not have any StatusConditions or Listeners and cannot be enabled.
Add to the table in section 2.1.3 for the ENTITY_FACTORY policy in the  "Concerns" column also the DomainParticipantFactory.
Add to the IDL in section 2.2.3 the following things:

struct  DomainParticipantFactoryQos {
    EntityFactoryQosPolicy  entity_factory;
};

interface DomainParticipantFactory {
    …..
    ReturnCode_t set_qos(in DomainParticipantQos qos);
    ReturnCode_t get_qos(inout DomainParticipantQos qos);
}; 

The READER_DATA_LIFECYCLE QoS specifies an autopurge_nowriter_samples_delay, however for the same reasons there should also be a autopurge_disposed_samples_delay.
Resolution:
Add the missing operation
Revised Text:
In section 2.1.3.21 add at the end:
The autopurge_disposed_samples_delay defines the maximum duration for which the DataReader will maintain information regarding an instance once its view_state becomes DISPOSED. After this time elapses, the DataReader will purge all internal information regarding the instance, any untaken samples will also be lost
In figure 2-12, class ReaderDataLifecycleQosPolicy, add "autopurge_disposed_samples_delay: Duration_t"
In section 2.2.3 (IDL) add the field  "Duration_t autopurge_disposed_samples_delay" to struct ReaderDataLifecycleQosPolicy

The mapping from PIM to IDL PSM for the operation Subscriber::get_datareaders represents the PIM 'out' sequence parameter to an IDL 'out' parameter. This maaping is inconsistent with that in other places in the API, in which PIM 'out' parameters are represented as 'inout' in the PSM. An 'out' parameter is also undesirable from a performance perspective.


Proposed Resolution:
The sequence argument to Subscriber::get_datareaders should be an 'inout' in the IDL PSM.


Proposed Revised Text:
In section 2.2.3:


ReturnCode_t get_datareaders(
inout DataReaderSeq readers,
in SampleStateMask sample_states,
in ViewStateMask view_states,
in InstanceStateMask instance_states);

The Topic interface in the PSM is missing the following operations which are present in the PIM: get_qos, set_qos, get_listener, and set_listener.


Proposed Resolution:
Add the missing operations to the IDL interface.


Proposed Revised Text:
In section 2.2.2:


interface Topic : Entity, TopicDescription {
ReturnCode_t get_qos(inout TopicQos qos);
ReturnCode_t set_qos(in TopicQos qos);
TopicListener get_listener();
ReturnCode_t set_listener(
in TopicListener a_listener,
StatusKindMask mask);
};

The types TopicSeq, SampleStateSeq, ViewStateSeq and InstanceStateSeq all appear in the IDL PSM but are never used.


Proposed Resolution:
Remove the unused types from the IDL PSM.


Proposed Revised Text:
The following declarations should be removed from the IDL PSM:


typedef sequence<Topic> TopicSeq;
typedef sequence <SampleStateKind> SampleStateSeq;
typedef sequence<ViewStateKind> ViewStateSeq;
typedef sequence<InstanceStateKind> InstanceStateSeq;

The QoS table in section 2.1.3 does not mention the field names in the USER_DATA, TOPIC_DATA, and GROUP_DATA QoS policies. The UML diagram in figure 2-12 gives the names of these fields as "data"; however, that name is inconsistent with the names given in the IDL PSM.


Proposed Resolution:
The table and figure should indicate that the name of the field in each policy is "value." That name is consistent with the IDL PSM.


Proposed Revised Text:
In 2.1.3 figure 2-12, UserDataQosPolicy:
value [*] : char


In 2.1.3 figure 2-12, TopicDataQosPolicy:
value [*] : char


In 2.1.3 figure 2-12, GroupDataQosPolicy:
value [*] : char
In the table in 2.1.3, in the "Value" column of the USER_DATA, TOPIC_DATA, and GROUP_DATA rows:
"value": a sequence of octets

The constants in the enumeration SampleRejectedStatusKind should correspond to the fields of the RESOURCE_LIMITS QoS policy.


Proposed Resolution:
Remove the constant REJECTED_BY_TOPIC_LIMIT. Add the constants REJECTED_BY_SAMPLES_LIMIT and REJECTED_BY_SAMPLES_PER_INSTANCE_LIMIT.


Proposed Revised Text:
enum SampleRejectedStatusKind {
REJECTED_BY_INSTANCE_LIMIT,
REJECTED_BY_SAMPLES_LIMIT,
REJECTED_BY_SAMPLES_PER_INSTANCE_LIMIT
};

A number of operations in the specification have a void return type. However, without a specified return type, an implementation cannot indicate that an error occurred.


Proposed Resolution:
The following methods currently return void and should return ReturnCode_t instead.
· GuardCondition::set_trigger_value
· DomainParticipant::get_default_publisher_qos
· DomainParticipant::get_default_subscriber_qos
· DomainParticipant::get_default_topic_qos
· DomainParticipant::assert_liveliness
· DomainParticipantFactory::get_default_participant_qos
· Publisher::get_default_datawriter_qos
· Subscriber::get_default_subscriber_qos
· DataWriter::assert_liveliness
· Subscriber::notify_datareaders
(The get_qos operations on each concrete Entity type are show to return void in the IDL PSM but a list of QoS policies in the PIM. That inconsistency is addressed in another issue.)


Proposed Revised Text:
In the GuardCondition Class table in 2.1.2.1.8, the void return type of set_trigger_value should be replaced by ReturnCode_t. The return type of that operation must be similarly changed in the IDL PSM in 2.2.3.
In the DomainParticipant Class table in 2.1.2.2.1, the void return type of the get_default_*_qos operations and the assert_liveliness operation should be replaced by ReturnCode_t. The return types of those operations should be similarly changed in the IDL PSM in 2.2.3.
In the Publisher Class table in 2.1.2.4.1, the void return type of get_default_datawriter_qos should be replaced by ReturnCode_t. The return type of that operation must be similarly changed in the IDL PSM in 2.2.3.
In the DataWriter Class table in 2.1.2.4.2, the void return type of assert_liveliness should be replaced by ReturnCode_t. The return type of that operation must be similarly changed in the IDL PSM in 2.2.3.
In the Subscriber Class table in 2.1.2.5.2, the void return type of get_default_datareader_qos and notify_datareaders should be replaced by ReturnCode_t. The return type of those operations must be similarly changed in the IDL PSM in 2.2.3.

The PublicationBuiltinTopicData type is missing a destination order field.


Proposed Resolution:
Add the missing field in both the PIM and the IDL PSM.


Proposed Revised Text:
In the "DCPSPublication" row of the table in 2.1.5, pg. 2-131, add a sub-row like the following after the existing "ownership_strength" sub-row:
destination_order DestinationOrderQosPolicy Policy of the corresponding DataWriter


In the IDL PSM, modify the PublicationBuiltinTopicData declaration as follows (the member immediately preceding the new member is show below in order to demonstrate the position of the new member):


struct PublicationBuiltinTopicData {
OwnershipStrengthQosPolicy ownership_strength;
DestinationOrderQosPolicy destination_order;
};

The specification does not state what the valid range of the transport priority values is, now does it state whether higher or lower values correspond to higher priorities.


Proposed Resolution:
Stipulate that the range of TransportPriorityQosPolicy::value is the entire range of a 32 bit signed integer. Larger numbers indicate higher priority. However, the precise interpretation of the value chosen is transport- and implementation-dependent.


Proposed Revised Text:
The second paragraph of section 2.1.3.14 contains the sentence:
"As this is specific to each transport it is not possible to define the behavior generically."


This sentence should be rewritten as follows:
"Any value within the range of a 32-bit signed integer may be chosen; higher values indicate higher priority. However, any further interpretation of this policy is specific to a particular transport and a particular implementation of the Service. For example, a particular transport is permitted to treat a range of priority values as equivalent to one another."

There are get_key_value operations in the DataReader and DataWriter to translate from an instance handle to a key. However, in order for a client of the Service to use the per-instance read and take operations of a DataReader, it would be convenient to have an operation to translate in the other direction: from key value(s) to an instance handle.


Proposed Resolution:
Add operations DataReader::lookup_instance and DataWriter::lookup_instance.


Proposed Revised Text:
Append the following rows to the DataWriter Class table in 2.1.2.4.2:
lookup_instance InstanceHandle_t
Instance Data


Add a new section "2.1.2.4.2.23 lookup_instance" with the following contents:
This operation takes as a parameter an instance (to get the key value) and returns a handle that can be used in successive operations that accept an instance handle as an argument.
This operation does not register the instance in question. If the instance has not been previously registered, or if for any other reason the Service is unable to provide an instance handle, the Service will return the special value HANDLE_NIL.


Append the following rows to the DataReader Class table in 2.1.2.5.3:
lookup_instance InstanceHandle_t
Instance Data


Add a new section "2.1.2.5.3.33 lookup_instance" with the following contents:
This operation takes as a parameter an instance (to get the key value) and returns a handle that can be used in successive operations that accept an instance handle as an argument.
If for any reason the Service is unable to provide an instance handle, the Service will return the special value HANDLE_NIL.

Title: (R#120) Clarify use of DATAREADER_QOS_USE_TOPIC_QOS constant when creating DataReader on ContentFilteredTopic or MultiTopic


Summary:
The specification defines the constant DATAREADER_QOS_USE_TOPIC_QOS that may be used to specify the QoS of a DataReader. The meaning of such usage is unclear when the DataReader's TopicDescription is a ContentFilteredTopic or a MultiTopic since those types do not have QoS of their own.


Proposed Resolution:
A ContentFilteredTopic is based on a single Topic; therefore, the meaning of DATAREADER_QOS_USE_TOPIC_QOS is well-defined in that case: it refers to the QoS of the Topic accessible via the ContentFilteredTopic::get_related_topic operation.
The meaning of DATAREADER_QOS_USE_TOPIC_QOS is not well-defined in the case of a MultiTopic; using it to set the QoS of a DataReader of a MultiTopic is an error. Specifically, passing the constant to Subscriber::create_datareader when a MultiTopic is also passed to that operation will result in the operation returning nil.


Proposed Revised Text:
The last paragraph of section "2.1.2.5.2.5 create_datareader" (which begins "The special value…") should be rewritten as follows:
Provided that the TopicDescription passed to this method is a Topic or a ContentFilteredTopic, the special value DATAREADER_QOS_USE_TOPIC_QOS can be used to indicate that the DataReader should be created with a combination of the default DataReader QoS and the Topic QoS. (In the case of a ContentFilteredTopic, the Topic in question is the ContentFilteredTopic's "related Topic.") The use of this value is equivalent to the application obtaining the default DataReader QoS and the Topic QoS (by means of the operation Topic::get_qos) and then combining these two QoS using the operation copy_from_topic_qos whereby any policy that is set on the Topic QoS "overrides" the corresponding policy on the default QoS. The resulting QoS is then applied to the creation of the DataReader. It is an error to use DATAREADER_QOS_USE_TOPIC_QOS when creating a DataReader with a MultiTopic; this method will return a nil value in that case.

A DataReader must specify a TimeBasedFilterQosPolicy::minimum_separation value that is less than or equal to its DeadlineQosPolicy::period value. (Otherwise, all matched DataWriters will be considered to miss every deadline.)
There are dependencies among the fields of ResourceLimitsQosPolicy: max_samples >= max_samples_per_instance.
The above dependencies are not made explicit in the specification.


Proposed Resolution:
The above dependencies should be made explicit in the QoS policy table in section 2.1.3.


Proposed Revised Text:
The following sentence should be added to the "Meaning" column of the "DEADLINE" row: "It is inconsistent for a DataReader to have a deadline period less than its TIME_BASED_FILTER's minimum_separation."


The following sentence should be added to the "Meaning" column of the "TIME_BASED_FILTER" row: "It is inconsistent for a DataReader to have a minimum_separation longer than its deadline period."


The following sentence should be added to the "Meaning" column of the "max_samples" row: "It is inconsistent for this value to be less than max_samples_per_instance."


The following sentence should be added to the "Meaning" column of the "max_samples_per_instance" row: "It is inconsistent for this value to be greater than max_samples."

It would be useful to have an additional return code called RETCODE_ILLEGAL_OPERATION. This return code would be useful, for example, in preventing the user from performing certain operations on the built-in DataReaders. Their QoS values are stated in the specification; vendors need not allow those values to be changed. Users should also not be allowed to delete built-in Entities. If the user tries to perform either of these two operations, the choices of return code we could use that are in accordance to the spec are:
· RETCODE_ERROR
· RETCODE_UNSUPPORTED
· RETCODE_BAD_PARAMETER
· RETCODE_PRECONDITION_NOT_MET
· RETCODE_IMMUTABLE_POLICY


All of the above fall short of helping the user find out what the problem really is.
· RETCODE_ERROR: This is the generic error code; it does not give much information as to what might be wrong.
· RETCODE_UNSUPPORTED: This choice would be semantically incorrect. The failure is not due to a vendor's failure to support an optional feature of the specification, but rather to the user's violation of a policy consistent with the specification that was set by that vendor.
· RETCODE_BAD_PARAMETER: This return code is a little confusing. For instance, when trying to delete a built-in DataReader, the reader parameter passed is a valid DataReader and the function is expecting a reader. Such usage would seem to constitute passing a good parameter, not a bad one.
· RETCODE_PRECONDITION_NOT_MET: There is no precondition that the user could change that would make the call work. Therefore, this result would be confusing.
· RETCODE_IMMUTABLE_POLICY: This return code could potentially work when trying to change the QoS policies of the built-in DataReaders but not when attempting to delete them. However, it would still be semantically incorrect. The problem is not that the user is trying to change immutable QoS policies.


The QoS policies being changed may be mutable; what is not allowed is the Entity whose policies are in question. Such a return result could lead the user to think that s/he is confused about which QoS policies are mutable.


Proposed Resolution:
Add a return code RETCODE_ILLEGAL_OPERATION. This return code indicates a misuse of the API provided by the Service. The user is invoking an operation on an inappropriate Entity or at an inappropriate time. There is no precondition that could be changed to allow the operation to succeed.
Vendors may use this new return code to indicate violations of policies they have set that are consistent with, but not fully described by, the specification. It is therefore necessary that the return code be considered a "standard" return code (like RETCODE_OK, RETCODE_BAD_PARAMETER, and RETCODE_ERROR) that could potentially be returned by any operation having the return type ReturnCode_t.


Proposed Revised Text:
Add the following row to the "Return codes" table in 2.1.1.1:
ILLEGAL_OPERATION An operation was invoked on an inappropriate object or at an inappropriate time (as determined by policies set by the specification or the Service implementation). There is no precondition that could be changed to make the operation succeed.


In the paragraph following the table, the sentence "Any operation with return type ReturnCode_t may return OK or ERROR" should be restated "Any operation with return type ReturnCode_t may return OK, ERROR, or ILLEGAL_OPERATION." The sentence "The return codes OK, ERROR, ALREADY_DELETED, UNSUPPORTED, and BAD_PARAMETER are the standard return codes and the specification won't mention them explicitly for each operation" should be restated as "The return codes OK, ERROR, ILLEGAL_OPERATION, ALREADY_DELETED, UNSUPPORTED, and BAD_PARAMETER are the standard return codes and the specification won't mention them explicitly for each operation".

The description of DataWriter::dispose needs to clarify whether it can be called with a nil handle.


Proposed Resolution:
DataWriter::dispose should just behave like DataWriter::write in that if the instance is not yet registered, the Service will automatically register it for the user. In that case, the operation should not return PRECONDITION_NOT_MET.


Proposed Revised Text:
The second-to-last paragraph in section 2.1.2.4.2.12 states "The operation must be only called on registered instances. Otherwise the operation will return the error PRECONDITION_NOT_MET." This paragraph should be removed.

The specification currently states that the DataWriter::write operation may return TIMEOUT under certain circumstances. However, the DataWriter operations dispose, register, unregister, and their variants may also block due to a temporarily full history.


Proposed Resolution:
Revise the documentation for the listed operations to state that they may return TIMEOUT if the RELIABILITY max_blocking_time elapses.


Proposed Revised Text:
The following paragraph should be appended to sections 2.1.2.4.2.5, 2.1.2.4.2.6, 2.1.2.4.2.7, 2.1.2.4.2.8, 2.1.2.4.2.12, and 2.1.2.4.2.13:
This operation may block if it would cause data to be lost or one of the limits specified in the RESOURCE_LIMITS to be exceeded. Under these circumstances, the RELIABILITY max_blocking_time configures the maximum time this operation may block (waiting for space to become available). If max_blocking_time elapses before the DataWriter is able to store the modification without exceeding the limits, this operation will fail and return TIMEOUT

The IDL PSM defines the type BuiltinTopicKey_t to be an array of element type BUILTIN_TOPIC_KEY_TYPE_NATIVE. This definition prevents some compilers from permitting shallow copies of instances of this type.


Proposed Resolution:
Redefine BuiltinTopicKey_t to be a structure containing an array rather than the array itself.


Proposed Revised Text:
In 2.2.3, change this:


typedef BUILTIN_TOPIC_KEY_TYPE_NATIVE BuiltinTopicKey_t[3]
to this:


struct BuiltinTopicKey_t {
BUILTIN_TOPIC_KEY_TYPE_NATIVE value[3];
}

The specification does not currently state whether it is permissible to create a DataReader or DataWriter with a TopicDescription that was created from a DomainParticipant other than that used to create the reader or writer's factory.


Proposed Resolution:
The use case in question is not allowed; create_datareader and create_datawriter should return nil in that case.


Proposed Revised Text:
The following paragraph should be appended to section 2.1.2.4.1.5 create_datawriter:
The Topic passed to this operation must have been created from the same DomainParticipant that was used to create this Publisher. If the Topic was created from a different DomainParticipant, this operation will fail and return a nil result.
The following paragraph should be appended to section 2.1.2.5.2.5 create_datareader:
The TopicDescription passed to this operation must have been created from the same DomainParticipant that was used to create this Subscriber. If the TopicDescription was created from a different DomainParticipant, this operation will fail and return a nil result.

The specification does not state what should occur if the user attempts to delete a DataReader when it has one or more outstanding loans as a result of a call to DataReader::read, DataReader::take, or a variant thereof.


Proposed Resolution:
State that Subscriber::delete_datareader should fail and return PRECONDITION_NOT_MET in that case.


Proposed Revised Text:
In section 2.1.2.5.2.6 delete_datareader, there is a paragraph (beginning "The deletion of a DataReader is not allowed…") that describes the operation's behavior in the event that some conditions created from the reader have not been deleted. Following that paragraph a new paragraph should be added:
The deletion of a DataReader is not allowed if it has any outstanding loans as a result of a call to read, take, or one of the variants thereof. If the delete_datareader operation is called on a DataReader with one or more outstanding loans, it will return PRECONDITION_NOT_MET

The specification does not make clear whether the set of status kinds returned by Entity::get_status_changes when that operation is invoked on a factory Entity (such as a Publisher) should include the changed statuses of the Entities created from that factory (such as a DataWriter).


Proposed Resolution:
Clarify that the set of status kinds will only contain the statuses that have changed on the Entity on which get_status_changes is invoked and not that Entity's contained Entities.


Proposed Revised Text:
Append the following sentence to section 2.1.2.1.1.6: "A 'triggered' status on an Entity does not imply that that status is triggered on the Entity's factory."

In the description of DataWriter::unregister in section 2.1.2.4.2.7 it says that if an instance is unregistered via a call to DataWriter::unregister, a matched DataReader will get an indication that its LIVELINESS_CHANGED status has changed.
However, unregister refers to an instance; the LIVELINESS_CHANGED status is based on the liveliness of a DataWriter, not an instance.


Proposed Resolution:
Instead the specification should state that the DataReader will receive a sample with a NOT_ALIVE_NO_WRITERS instance state.


Proposed Revised Text:
The sentence:
DataReader objects that are reading the instance will eventually get an indication that their LIVELINESS_CHANGED status (as defined in Section 2.1.4.1) has changed.
…should be rewritten:
DataReader objects that are reading the instance will eventually receive a sample with a NOT_ALIVE_NO_WRITERS instance state if no other DataWriter objects are writing the instance.

There are two limitations to the PublicationMatchStatus and SubscriptionMatchStatus that prevent them from being used to detect the loss of a match:
· The specification does not indicate whether those statuses are considered to have changed when a match is lost (e.g. as a result of a loss of liveliness or an incompatible QoS change).
· The status structures contain fields that indicate the total number of matches that have ever occurred, but they lack fields to indicate the number of current matches.


Proposed Resolution:
Two fields should be added to each status structure: current_count and current_count_change. The specification should be updated to state that the publication and subscription match statuses are considered to have changed both when a match is established and when it is lost.


Proposed Revised Text:
Update the table in 2.1.4.1 as follows:


DataReader SUBSCRIPTION_MATCH_STATUS The DataReader has found a DataWriter that matches the Topic and has compatible QoS or has stopped communicating with a DataWriter that was previously considered to have matched.


DataWriter PUBLICATION_MATCH_STATUS The DataWriter has found DataReader that matches the Topic and has compatible QoS or has stopped communicating with a DataReader that was previously considered to have matched.


Update PublicationMatchStatus and SubscriptionMatchStatus in figure 2-13 to add the following attributes to each:


current_count : long
current_count_change : long


Update the PublicationMatchStatus section of the table on page 2-119 with the following rows:
current_count The number of DataReaders currently matched to the concerned DataWriter.
current_count_change The change in current_count since the last time the listener was called or the status was read.


Update the SubscriptionMatchStatus section of the table on page 2-119 with the following rows:
current_count The number of DataWriters currently matched to the concerned DataReader.
current_count_change The change in current_count since the last time the listener was called or the status was read.


Modify the declarations of the PublicationMatchStatus and SubscriptionMatchStatus structures in the IDL PSM in 2.2.3 as follows:


struct PublicationMatchStatus {
long total_count;
long total_count_change;
long current_count;
long current_count_change;
InstanceHandle_t last_subscription_handle;
};


struct SubscriptionMatchStatus {
long total_count;
long total_count_change;
long current_count;
long current_count_change;
InstanceHandle_t last_publication_handle;
};

It would be useful to have a field in LivelinessChangedStatus that provides the instance handle for the last DataWriter for which there was a change in liveliness.


Proposed Resolution:
Add a field last_publication_handle to LivelinessChangedStatus.


Proposed Revised Text:
Add an attribute "last_publication_handle : InstanceHandle_t" to LivelinessChangedStatus in figure 2-13.
Add a row to the LivelinessChangedStatus section of the table on page 2-118:
last_publication_handle Handle to the last DataWriter whose change in liveliness caused this status to change.
Revise the definition of LivelinessChangedStatus in the IDL PSM in 2.2.3:


struct LivelinessChangedStatus {
InstanceHandle_t last_publication_handle;
};

Most statuses (and the callbacks corresponding to them) have names ending in a past tense verb (e.g. LivelinessLost, LivelinessChanged, *DeadlineMissed, etc.). This convention makes the names very understandable because they refer to an actual thing that happened.
The publication and subscription match statuses/callbacks violate this convention, however. They are named after the match itself, not the event of matching.


Proposed Resolution:
To make the match statuses/callbacks consistent, they should be called PublicationMatchedStatus (on_publication_matched) and SubscriptionMatchedStatus (on_subscription_matched).


Proposed Revised Text:


Replace "PublicationMatchStatus" with "PublicationMatchedStatus," "on_publication_match" with "on_publication_matched," "SubscriptionMatchStatus" with "SubscriptionMatchedStatus," and "on_subscription_match" with "on_subscription_matched" in the DomainParticipantListener table in 2.1.2.2.3.


Perform the same substitutions in the DataWriter table in 2.1.2.4.2 and in the DataWriterListener table in 2.1.2.4.4.


Perform the same substitutions in the DataReader table in 2.1.2.5.3 and in the DataReaderListener table in 2.1.2.5.7.


Rename "PublicationMatchStatus" to "PublicationMatchedStatus" and "SubscriptionMatchStatus" to "SubscriptionMatchedStatus" in figure 2-13, in the immediately following table of statuses, and in the IDL PSM definitions of the types PublicationMatchStatus, SubscriptionMatchStatus, DataWriterListener, DataReaderListener, DataWriter, and DataReader.

The OWNERSHIP QoS policy only concerns the Topic Entity. It is the only such policy; all other Topic QoS policies also concern the DataReader and DataWriter, which may override the value provided by the Topic.
The OWNERSHIP QoS policy is also missing from the PublicationBuiltinTopicData and SubscriptionBuiltinTopicData structures.


Proposed Resolution:
The OWNERSHIP QoS policy should concern the Topic, DataReader, and DataWriter Entities. It should have requested vs. offered (RxO) semantics: the two sides must agree on its value.
A field of type OwnershipQosPolicy should be added to the PublicationBuiltinTopicData and SubscriptionBuiltinTopicData structures.


Proposed Revised Text:
Change the "Concerns" column of the OWNERSHIP row of the table on page 2-94 to read "Topic, DataReader, DataWriter."


The second paragraph of section 2.1.3.8 OWNERSHIP begins "This QoS policy only applies to Topic and not to DataReader or DataWriter…" This paragraph should be removed.


Add the following rows to the built-in topic table on page 2-131:
DCPSPublication ownership OwnershipQosPolicy Policy of the corresponding DataWriter
DCPSSubscription Ownership OwnershipQosPolicy Policy of the corresponding DataReader


Modify the definitions of the DataWriterQos and DeadReaderQos structures in the IDL PSM in 2.2.3:


struct DataWriterQos {
OwnershipQosPolicy ownership;
};


struct DataReaderQosPolicy {
OwnershipQosPolicy ownership;
};

Several members in the Topic module are described as attributes in the UML diagram in 2.1.2.3 but as operations in the following tables and in the IDL PSM. These include:
· TopicDescription::type_name
· TopicDescription::name
· ContentFilteredTopic::filter_expression
· ContentFilteredTopic::expression_parameters
· MultiTopic::subscription_expression
· MultiTopic::expression_parameters
Also, the topic name and type name members are needlessly repeated in the tables of all of the TopicDescription subclasses. They are non-abstract; they need only appear in the TopicDescription table.


Proposed Resolution:
The read-only attributes should appear as such in the PIM tables. "Attributes" that can be changed return ReturnCode_t from the corresponding "set" methods; for clarity, they should consistently appear as operations in both the tables and the UML diagram. The duplicate descriptions of the topic name and type name attributes should be removed.
The IDL PSM should continue to express all of the members as methods to preserve the consistency of the naming conventions used in all programming languages that may be generated from the IDL.


Proposed Revised Text:


In figure 2-7, replace the ContentFilteredTopic attribute expression_parameters with two operations: get_expression_parameters and set_expression_parameters. Replace the MultiTopic attribute expression_parameters with two operations: get_expression_parameters and set_expression_parameters.


Revise the TopicDescription Class table in 2.1.2.3.1 as follows:
TopicDescription
attributes
readonly name string
readonly type_name string
operations
get_participant DomainParticipant


Rewrite section 2.1.2.3.1.2 as follows:
2.1.2.3.1.2 type_name
The type name used to create the TopicDescription.


Rewrite section 2.1.2.3.1.3 as follows:
2.1.2.3.1.3 name
The name used to create the TopicDescription.
Remove the get_type_name and get_name operations from the Topic Class table in 2.1.2.3.2.
Remove the get_type_name, get_name, and get_filter_expression operations from the ContentFilteredTopic Class table in 2.1.2.3.3. Add the following attributes to that table:
attributes
readonly filter_expression string


Rewrite section 2.1.2.3.3.2 as follows:
2.1.2.3.3.2 filter_expression
The filter_expression associated with the ContentFilteredTopic. That is, the expression specified when the ContentFilteredTopic was created.


Remove the get_type_name, get_name, and get_subscription_expression operations from the MultiTopic Class table in 2.1.2.3.4. Add the following attributes to that table:
attributes
readonly subscription_expression string


Rewrite section 2.1.2.3.3.2 as follows:
2.1.2.3.4.1 get_subscription_expression
The subscription_expression associated with the MultiTopic. That is, the expression specified when the MultiTopic was created.

The description of register_type in 2.1.2.3.6.1 first says that the operation may return PRECONDITION_NOT_MET but later says that the only "special" error code that may be returned is OUT_OF_RESOURCES.


Proposed Resolution:
The operation should be able to return either PRECONDITION_NOT_MET or OUT_OF_RESOURCES.


Proposed Revised Text:
The last sentence of section 2.1.2.3.6.1 should read "Possible error codes returned in addition to the standard ones: PRECONDITION_NOT_MET and OUT_OF_RESOURCES."

The operation WaitSet::wakeup is listed in the UML diagrams in 2.1.2.1 and 2.1.4.4. This operation is not listed in the WaitSet table in 2.1.2.1.6.


Proposed Resolution:
The GuardCondition class already provides a mechanism for manually waking up a WaitSet. The wakeup method should be struck from the UML diagrams noted above.


Proposed Revised Text:
Remove the wakeup operation from the WaitSet class in figure 2-5 and in figure 2-18.

The value of the SampleRejectedStatus::last_reason field is undefined in that case where the user calls get_sample_rejected_status when no samples have been rejected.


Proposed Resolution:
Introduce a new SampleRejectedStatusKind value NOT_REJECTED and stipulate that it is to be used in the case described above.


Proposed Revised Text:
Add the following sentence to the description of SampleRejectedStatus::last_reason in the table on page 2-118: "If no samples have been rejected, the reason is the special value NOT_REJECTED."
Modify the definition of SampleRejectedStatusKind in 2.2.3 to add a constant NOT_REJECTED.

The specification fails to state what should happen to publications suspended with Publisher::suspend_publications if Publisher::resume_publications is never called by the time the Publisher is deleted.
Proposed Resolution:
The Publisher may be deleted in the situation described. Any samples that have not yet been sent will be discarded.


Proposed Revised Text:
Add the following sentence to the last paragraph of section 2.1.2.4.1.8: "If the Publisher is deleted before resume_publications is called, any suspended updates yet to be published will be discarded."

The specification states that the mainTopic tag in the classMapping XML element is mandatory. However the example provided after does not contain that item, showing that it is actually not mandatory.
Resolution:
Change the status of that item in the DTD, to make it optional. 

The get_all_topic_names() operation is mentioned in section  3.1.6.3.5 (ObjectHome) and in the IDL, but not in Figure 3-4.
Resolution:
  Add the missing operation on the UML diagram

The parameter of "ObjectHome::set_filter" operation is named "expression" in the PIM and "filter" in the IDL.
The ObjectHome operation to register operation is named "register_object" in the UML diagram and in the ObjectHome table, but it is named "register_created_object" in the text and in the IDL.
Resolution:
Name everywhere "expression" the parameter of the set_filter" operation
Name everywhere "register_object" the operation to register an object

The parameter of "Cache:: find_home_by_index" is named "registration_index" in the PIM and "index" in the IDL
Resolution:
Name everywhere that parameter "index"

Bad cardinality for relations Cache-> CacheListener and ObjectHome->ObjectListener on figure 3-4
Summary:
While the PIM text and the IDL state that several CacheListeners may be attached to a Cache and several ObjectListeners may be attached to an ObjectHome, the UML diagram shows a cardinality of at most 1 for those relations
Resolution:
 Correct the figure to be in accordance with the rest of the document.

The IDL section states that the operations "clone" and "clone_object" on "ObjectRoot" as well as the operation "clone_foo" on the implied IDL for "Foo" may raise the exception "ReadOnlyMode", while this is not true.
Resolution:
 Correct the IDL

A wrong copy-paste lead to wrong inheritance and methods for the FooListener interface in the implied IDL (while it is correct in the PIM). In addition, the IDL for ObjectListener should have commented out the operation that is actually defined in the derived FooListener.
FooListener is mentioned once in the PIM as FooObjectListener.
Resolution:
Fix the definition (based on ObjectListener) and name the class FooListener everywhere

In section 3.1.6.5, the specification suggests that it is sensible to create a CacheUsage per thread. This should say a CacheAccess instead.
Resolution:
Change CacheUsage to CacheAccess in the sentence.

In section 3.2.2.3.2.3, the templateDef is explained. The 2nd bullet presents the possible values of the pattern  attribute, but in this list "Ref" is missing. Furthermore, the example uses the wrong attribute name in its 2nd attribute: it says basis="StrMap", while this should be pattern="StrMap"
Resolution:
 Correct the mistakes.

In the implied IDL, "DlrlOid" is used 3 times instead of the correct "DLRLOid"
Resolution:
Use "DLRLOid" everywhere 

The "set" operation in the implied "FooRef" IDL class has a parameter named object. Since IDL may be used both case-sensitive and case-insensitive, this may not be allowed (possible confusion with CORBA::Object)
Resolution:
 Name this parameter "an_object"

The ObjectListeners that need to be registered to an ObjectHome are typed (i.e. a FooListener must be attached to a FooHome), but the definition of the attach and detach methods can only be found in the generic IDL part. This way it is possible to attach a BarListener to a FooHome.
Resolution:
Move those operations from the generic IDL to the implied one.

The "remove" operations of the collection types are mentioned in the implied IDL part, while their signatures have no typed parameters.
In addition, the parameter for the get operation (key) wrongly starts with a capital letter (while all parameters are supposed to be in small letters)
Resolution:
Add those operations on the generic roots and remove them from the generated classes (implied IDL). 
Correct the spelling of the "key" parameter.

It is not clearly defined whether the on_data_available notification should be generated on every arrival of new data, or just on the status change that happens when coming from a no data situation.
Resolution:
For every arrival of new data, a notification should be generated, regardless of whether the previous data has already been read before.
Revised Text:
Introduce textual changes to 2.1.4.2.2 that describes the complete set of conditions under which the read-communication status will change. The data available status is considered to have changed each time a new sample becomes available or the ViewState, SampleState, or InstanceState of any existing sample changes for any reason other than a read or take.
Specific changes that cause the status to be changed include:
·	The arrival of new data
·	The disposal of an instance
·	The loss of liveliness of a writer of an instance when no other writer of that instance exists
·	Unregistration of an instance by the last writer of that instance

In section 2.1.2.1.1.7 it is explained which entity operations may be invoked on an entity that has not yet been enabled. However, in subsequent sections describing the behavior of operations on specialized entities that are disabled, fewer than the above-mentioned operations are mentioned.
Resolution:
Add the missing operations for each specialized entity to the list of operations that will never return RETCODE_NOT_ENABLED. Also state explicitly that Conditions obtained from disabled entities will never trigger, until the corresponding entities become enabled.
Revised Text:
On page 2-13, section 2.1.2.1.1.7 it is stated that the operation that gets the StatusCondition can be invoked on a disabled entity. Add some text that specifies that a StatusCondition obtained this way will not trigger until the corresponding entity becomes enabled.
On page 2-21, section 2.1.2.2.1 it is mentioned that for the DomainParticipant all operation except get/set_qos, get/set_listener and enable may return a RETCODE_NOT_ENABLED. To this list should be added: get_statuscondition, all factory methods (create_topic, create_publisher, create_subscriber) and all delete methods (delete_topic, delete_publisher, delete_subscriber).

On page 2-35, section 2.1.2.3.2 it is mentioned that for the Topic all operations except get/set_qos, get/set_listener and enable may return a RETCODE_NOT_ENABLED. To this list should be added: get_statuscondition.
On page 2-42, section 2.1.2.4.1 it is mentioned that for the Publisher all operations except get/set_qos, get/set_listener and enable may return a RETCODE_NOT_ENABLED. To this list should be added: get_statuscondition, create_datawriter, delete_datawriter.
On page 2-48, section 2.1.2.4.2 it is mentioned that for the DataWriter all operations except get/set_qos, get/set_listener and enable may return a RETCODE_NOT_ENABLED. To this list should be added: get_statuscondition.
On page 2-63, section 2.1.2.5.2 it is mentioned that for the Subscriber all operations except get/set_qos, get/set_listener and enable may return a RETCODE_NOT_ENABLED. To this list should be added: get_statuscondition, create_datareader and delete_datareader.
On page 2-73, section 2.1.2.5.3 it is mentioned that for the DataRaeder all operations except get/set_qos, get/set_listener and enable may return a RETCODE_NOT_ENABLED. To this list should be added: get_statuscondition.

In section 2.1.3 (Supported Qos) the table describes that specifying the PARTITION QOS by an empty sized sequence implies all partitions. However the default partition is specified to be exactly one partition with the name "". Any partition should be specified by means of wildcards. It is unclear how the default partition and wildcards can be used at publisher and subscriber side.
Resolution:
Concerning default partitions:
The default value for PartitionQosPolicy is an empty sequence of names.The empty sequence of partition names is equivalent to a single partition name, the empty string.
Concerning wildcards:
"Wildcards" refers to the regular expression language defined by the POSIX fnmatch API (1003.2-1992 section B.6). Either Publisher or Subscriber may include regular expressions in partition names, but no two names that both contain wildcards will ever be considered to match. This means that although regular expressions may be used both at publisher as well as subscriber side, the service will not try to match 2 regular expressions (between publishers and subscribers).
Revised Text:

Change the PARTITION row of the table in 2.1.3 to state that the default value is an empty sequence, which is equivalent to a sequence containing the single element "".

Add the text about the wildcards format and restrictions

Does reliability include order preservation up to API level?
In other words should data be made available to applications if older data exists but has not yet arrived (e.g. due to network irregularities), note that if a late arriving sample is accepted even after newer samples are made available then state inconsistencies may occur. In addition, not accepting a late coming sample should generate a sample lost notification.
Resolution:
Specify that data from a single writer (reliable and/or best-effort) will NOT be made available out-of-order.
Revised Text:
TBD

It is not clear what the value of unlimited resource limits is. 
Resolution:
Probably it is defined by the in IDL defined constant LENGTH_UNLIMITED=-1. This should be clarified.
Revised Text:

Replace "unlimited" with "LENGTH_UNLIMITED" in table in 2.1.3

In par. (2.1.3.7) is described that latency budget will neither prohibit connectivity nor send notifications if incompatible. However it also describes the RxO compatibility rule that will never be visible to applications. This is somewhat confusing and this description is only required because this QoS attribute is specified to be subject to the RxO pattern, however, since the description states that the latency budget is a hint to the service and that the service may apply an additional delay for optimizations then are we really speaking of RxO between datawriters and datareaders?
Resolution:
Make latency budget truly RxO by making connectivity dependent of compatibility rules and adding appropriate error notifications.
Revised Text:
Remove the "therefore the service will not fail to match…" from section 2.1.3.7
Add new text that describes the RxO consequences

The specification does not clearly describe what should happen with data in a reliable datawriter's history when the datawriter is deleted? Should it disappear immediately or wait until all messages in the history are delivered? 
Resolution:
The right thing to do is provide some operation such that the user can wait for all data to be delivered:
Add an operation Publisher::delete_datawriter_after_acknowledgement( Duration_t timeout). Like DataReader::wait_for_historical_data, this operation takes its own timeout rather than using ReliabilityQosPolicy::max_blocking_time because it has to potentially wait for many writes to complete. As soon as all outstanding reliable samples are acknowledged, the DataWriter will be deleted and the operation will return OK. If timeout expires, however, before all samples are acknowledged, the operation will return TIMEOUT and the writer will not be deleted.
The regular Publisher::delete_datawriter should delete the writer immediately without waiting for any reliable samples to be acknowlwedged. Its description should be clarified accordingly. If delete_datawriter_after_acknowledgement fails, the user will then have the choice of either calling it again or accepting the possible loss of some samples and calling delete_datawriter.

Revised Text:
Change existing text according the resolution.

It is unclear if a topic found by lookup_topicdescription (section 2.1.2.2.1.13.) should also be deleted if not used anymore similar to find_topic.
Resolution:
lookup_topicdescription, unlike find_topic, should search only among the locally created topics. Therefore, it should never (at least as far as the user is concerned) create a new topic description. So looking up the topic should not require any extra deletion. (It is of course permitted to delete a topic one has looked up, provided it has no readers or writers, but then it is really deleted and subsequent lookups will fail).
Revised Text:
Change text in section 2.1.2.2.1.13 accordingly

For applications it is not possible to relate a sample to its datawriter. There are many use cases where it is required to be able to make such a relation
Resolution:
Add an 'InstanceHandle_t publication_handle' field (the handle to the remote writer, not the data instance) to SampleInfo. The user can use this handle to call get_matched_publication_data ()
Revised Text:	
Change SampleInfo definition and related explanation accordingly.

The entity::set listener method sets a listener in combination with a mask that specifies the event interest. Listeners can also be set at construction of entities by passing the listener as parameter to the entity factory method. However it is not possible to set a mask during construction.
Resolution:
Add an event mask parameter (listener_mask) to entity constructors.
Revised Text:
Change signature and description of all entity factory methods.
 

The entity::set listener method sets a listener in combination with a mask that specifies the event interest. Listeners can also be set at construction of entities by passing the listener as parameter to the entity factory method. However it is not possible to set a mask during construction.
Resolution:
Add an event mask parameter (listener_mask) to entity constructors.
Revised Text:
Change signature and description of all entity factory methods.
 

Resolution:
Discard as it duplicates Issue#8554

Currently entities must be enabled before they can be deleted.
Resolution:	
Specify that entities may be deleted if not enabled. 
Revised Text:
Explicilty state on each class that the delete method can be called also on disabled entities.

Resolution:	
Specify that entities may be deleted if not enabled. 
Revised Text:
In Section 2.1.2.1.1.7 enable; at the end of the paragraph:
"If an Entity has not yet been enabled, the only operations that can be invoked on it are the ones to set or get the QoS policies and the listener, the ones that get the StatusCondition, and the 'factory' operations that create other entities. Other operations will return the error NOT_ENABLED."
Add the paragraph:
It is legal to delete an Entity that has not been enabled by calling the proper operation on its factory.

Some customers require guarantees on delivery to the network, i.e. a means to block until  the service can guarantee that the data will be or is received by all recipients.
Resolution:
Add a Publisher::wait_for_acknowlegments(timeout) method that will block until all data written by all its writers  has been acknowledged. If called with Publisher is suspended it will return PRECONDITION_NOT_MET
Revised Text:
Add a paragraph describing the function, add the function to the publisher-table, change the PSM to include the new function.

The current IDL PSM contains the following lines:

#define HANDLE_TYPE_NATIVE long
#define HANDLE_NIL_NATIVE  0

typedef HANDLE_TYPE_NATIVE InstanceHandle_t;
const InstanceHandle_t HANDLE_NIL = HANDLE_NIL_NATIVE;

The two #defines can be vendor-specific. However, the constant definition in the last line restricts the HANDLE_TYPE_NATIVE to be of integer, char, wide_char, boolean, floating_pt, string, wide_string, fixed_pt or octet type; IDL does not allow any other (e.g. structured) types to be assigned a constant value.
Resolution:
The PSM contains a number of other elements that cannot be accurately expressed in IDL (e.g. static methods). As in those other cases, a comment should be added stating that structured and other non-primitive types may be used for HANDLE_TYPE_NATIVE and HANDLE_NIL_NATIVE even though IDL can't express it
Revised Text:
Mention the above in the introduction of the PSM.

a) The semantics of the DURABILITY Qos attribute "service_cleanup_delay" in relation to RxO mechanism is not specified.
b) There is no relation between the history and resource-limits of the durability-service and the history and resource-limits of readers and writers.
c) the durability-service still has to be configured by means of the above mentioned parameters: 'service_cleanup_delay', 'history' and 'resource-limits'
Resolution:
Remove service_cleanup_delay from the DURABILITY QoS policy for readers and writers.
Add a new QoS "DURABILITY_SETTINGS" on the Topic whose sole purpose is to configure the durability service. The QoS policy should include the parameters: 'service_cleanup_delay', 'history' and 'resource-limits'.
Revised Text:
Remove the service_cleanup_delay from the DURABILITY QoS for readers and writers
Remove the history QoS and resource-limits QoS policies from the TopicBuiltinTopicData
Add the new DURABILITY_SETTINGS QoS and explain its behavior/meaning. 
Add this QoS policy also to the TopicBuiltinTopicData.
Update the PSM accordingly

The DDS supports timestamping of information, either automatically or manually. These timestamps also appear in the SampleInfo data. What is missing is a get_current_time() call that allows applications to retrieve the current-time in the format as is utilized by the DDS. This means that the returned format and starting-time is the same as is used by the default/internal DDS timestamping.

Resolution:
Add such a 'get_current_time()' function to the participant class
Revised Text:
Add and explain the method and update the PSM.

Whenever an instance handle is passed as an input-parameter to a dataReader method, it may be invalid e.g. because they are disposed and reclaimed. The semantics of this case should be clarified.
Resolution:
Assuming that implementations want to check for invalid handles, they should generically return 'BAD_PARAMETER'. 
Revised Text:
Specify that BAD_PARAMETER is returned when providing illegal handles to:
·	Read/Take_instance
·	Read/Take_next_instance
·	Read/Take_next_instance_with_condition
·	Get_key_value (both on dataReader and dataWriter)

If a QoS policy is not supported (i.e.  is part of an unsupported profile) but the user supplies a non-default value for it, how should the system react
Resolution:
Just return UNSUPPORTED
Revised Text:
Add a remark in the specification that retcode UNSUPPORTED is returned when supplying a QoS-policy that is not supported by the middleware (i.e. is part of an optional-profile that is not supported by the specific middleware implementation)

Section 2.1.1.2.2 states: "At the DCPS level, data types represent information that is sent atomically. For performance reasons, only plain data structures are handled by this level." It is not clear what "plain data structures" means.


Proposed Resolution:
Remove the second sentence quoted above from the specification.


Proposed Revised Text:
Remove the sentence "For performance reasons, only plain data structures are handled by this level" from section 2.1.1.2.2, page 2-7.

Discard. This issue duplicates Issue#7966

The operations QueryCondition::get_query_arguments and QueryCondition::set_query_arguments are named inconsistently with respect to similar operations on the ContentFilteredTopic and the MultiTopic.


Proposed Resolution:


Rename get_query_arguments to get_query_parameters and set_query_arguments to set_query_parameters both in the PIM and PSM.


Proposed Revised Text:


Rename get_query_arguments to get_query_parameters and set_query_arguments to set_query_parameters in the table in section 2.1.2.5.9. Rename set_query_arguments to set_query_parameters in the paragraph immediately following the table in the same section.


Rename get_query_arguments to get_query_parameters in the title of section 2.1.2.5.9.2. Rename set_query_arguments to set_query_parameters within that section (two occurrences).


Rename set_query_arguments to set_query_parameters in the title to section 2.1.2.5.9.3.


Rename set_query_arguments to set_query_parameters in figure 2-18.
Rename get_query_arguments to get_query_parameters and set_query_arguments to set_query_parameters in the IDL PSM in section 2.3.3, page 2-144.

Summary:


In Section 2.1.5, there is a table that lists all the QoS policies that are used to create built-in readers. Since the policies are for creating built-in readers, the table should only list the QoS for the corresponding subscriber, reader, and topic. It shouldn't list any policies that occur only in DataWriterQos. Specifically, TRANSPORT_PRIORITY, LIFESPAN, and OWNERSHIP_STRENGTH, all of which apply only to DataWriters, are currently listed erroneously.
The following QoS are supposed to apply to DataReaders (or their related entities) but are missing from the table: ReaderDataLifecycleQosPolicy, EntityFactoryQosPolicy


For the QoS that are already listed in the table, some of them don't list the default values of some of the fields.


DURABILITY: missing service_cleanup_delay value
RELIABILITY: missing max_blocking_time value


Proposed Resolution:


Remove TRANSPORT_PRIORITY, LIFESPAN, and OWNERSHIP_STRENGTH from the table.


Add the following values:


READER_DATA_LIFECYCLE autopurge_nowriter_samples_delay = INFINITE
ENTITY_FACTOR autoenable_created_entities = TRUE
DURABILITY service_cleanup_delay = 0
RELIABILITY max_blocking_time = 100 milliseconds


Proposed Revised Text:
Change the table in section 2.1.5, page 2-129, as described above.

The specification already provides the operations get_matched_publication_data and get_matched_subscription_data on the DataReader and DataWriter. These operations allow applications to look up information about entities that exist in the domain without having to use the built-in DataReaders directly. It would be useful to have the corresponding ability to look up information about remote DomainParticipants and Topics; however, no such operations exist. 


Proposed Resolution:


Add the following operations:
·       ReturnCode_t DomainParticipant::get_discovered_participants(inout InstanceHandle_t[] participant_handles)
·       ReturnCode_t DomainParticipant::get_discovered_participant_data(inout ParticipantBuiltinTopicData publication_data, InstanceHandle_t participant_handle)
·       ReturnCode_t DomainParticipant::get_discovered_topics(inout InstanceHandle_t[]topic_handles)
·       ReturnCode_t DomainParticipant::get_discovered_topic_data(inout TopicBuiltinTopicData topic_data, InstanceHandle_t topic_handle)


Proposed Revised Text:


Add the names of the aforementioned new operations to figure 2-6.


Append the following rows to the DomainParticipant Class table in 2.1.2.2.1:


get_discovered_participant_data         ReturnCode_t
        inout: publication_data ParticipantBuiltinTopicData
        participant_handle      InstanceHandle


get_discovered_participants             ReturnCode_t
        inout: participant_handles      InstanceHandle_t []


get_discovered_topic_data               ReturnCode_t
        inout: topic_data       TopicBuiltinTopicData
        topic_handle    InstanceHandle


get_discovered_topics           ReturnCode_t
        inout: topic_handles    InstanceHandle_t []


Insert new sections to describe the new operations:


2.1.2.2.1.26 get_discovered_participant_data


This operation retrieves information on a DomainParticipant that has been discovered on the network. The participant must be in the same domain as the participant on which this operation is invoked and must not have been "ignored" by means of the DomainParticipant ignore_participant operation.


The participant_handle must correspond to such a DomainParticipant. Otherwise, the operation will fail and return PRECONDITION_NOT_MET.


Use the operation get_matched_participants to find the DomainParticipants that are currently discovered.


The operation may also fail if the infrastructure does not hold the information necessary to fill in the participant_data. In this case the operation will return UNSUPPORTED.


2.1.2.2.1.27 get_discovered_participants


This operation retrieves the list of DomainParticipants that have been discovered in the domain and that the application has not indicated should be "ignored" by means of the DomainParticipant ignore_participant operation.


The operation may fail if the infrastructure does not locally maintain the connectivity information. In this case the operation will return UNSUPPORTED.
2.1.2.2.1.26 get_discovered_topic_data


This operation retrieves information on a Topic that has been discovered on the network. The topic must have been created by a participant in the same domain as the participant on which this operation is invoked and must not have been "ignored" by means of the DomainParticipant ignore_topic operation.


The topic_handle must correspond to such a topic. Otherwise, the operation will fail and return PRECONDITION_NOT_MET.
Use the operation get_discovered_topics  to find the topics that are currently discovered.


The operation may also fail if the infrastructure does not hold the information necessary to fill in the topic_data. In this case the operation will return UNSUPPORTED.


2.1.2.2.1.27 get_discovered_topics


This operation retrieves the list of Topics that have been discovered in the domain and that the application has not indicated should be "ignored" by means of the DomainParticipant ignore_topic operation.
The operation may fail if the infrastructure does not locally maintain the connectivity information. In this case the operation will return UNSUPPORTED.

The DDS spec currently states that the max_blocking_time parameter of the RELIABILITY QoS only applies for data writers that are RELIABLE and have HISTORY QoS of KEEP_ALL.  


These assertions are not true. Depending on the RESOURCE_LIMITS QoS, even a KEEP_LAST writer may eventually need to block.


Proposed Resolution:


The specification needs to be updated in the table of QoS in Section 2.1.3 and in the DataWriter section 2.1.2.4.2.10 for write to account for the case in which (max_samples < max_instances * HISTORY depth). In this case, the writer may attempt to write a new value for an existing instance whose history is not full and fail because it exceeds the max_samples limit. Therefore, if (max_samples < max_instances * HISTORY depth), then in the situation where the max_samples resource limit is exhausted the middleware is allowed to discard samples of some other instance as long as at least one sample remains for that instance. If it is still not possible to make space available for the new sample, the writer is allowed to block.


The behavior in the case where max_samples < max_instances must also be described. In that case the writer is allowed to block.


Proposed Revised Text:


In the QoS table in 2.1.3, change the first sentence of the "Meaning" cell of the RELIABILITY max_blocking_time row to: "This setting applies only to the case where kind=RELIABLE."


In section 2.1.2.4.2.10, replace the final paragraph with the following:


If the RELIABILITY kind is set to RELIABLE, the write operation on the DataWriter may block if the modification would cause data to be lost or else cause one of the limits specified in the RESOURCE_LIMITS to be exceeded. Under these circumstances, the RELIABILITY max_blocking_time configures the maximum time the write operation may block waiting for space to become available. If max_blocking_time elapses before the DataWriter is able to store the modification without exceeding the limits, the write operation will fail and return TIMEOUT.


Specifically, the DataWriter may block in the following situations (although the list may not be exhaustive), even if its HISTORY kind is KEEP_LAST.


·       If (RESOURCE_LIMITS max_samples < RESOURCE_LIMITS max_instances * HISTORY depth), then in the situation where the max_samples resource limit is exhausted the Service is allowed to discard samples of some other instance as long as at least one sample remains for such an instance. If it is still not possible to make space available to store the modification, the writer is allowed to block.


·       If (RESOURCE_LIMITS max_samples < RESOURCE_LIMITS max_instances), then the DataWriter may block regardless of the HISTORY depth.


In section 2.1.3.13 RELIABILITY, the second paragraph currently states:


The setting of this policy has a dependency on the setting of the HISTORY and RESOURCE_LIMITS policies. In case the RELIABILITY kind is set to RELIABLE and the HISTORY kind set to KEEP_ALL the write operation on the DataWriter may block if the modification would cause data to be lost or else cause one of the limits specified in the RESOURCE_LIMITS to be exceeded.


The above text should be rewritten as follows:


The setting of this policy has a dependency on the RESOURCE_LIMITS policy. In case the RELIABILITY kind is set to RELIABLE the write operation on the DataWriter may block if the modification would cause data to be lost or else cause one of the limits specified in the RESOURCE_LIMITS to be exceeded.

(R#132) Clarify meaning of LivelinessChangedStatus fields and LIVELINESS lease_duration


Summary:


The specification of LivelinessChangedStatus doesn't explain what the terms "active" and "inactive" mean nor what change is expected when various events occur. For example, the following actions should be accounted for:
·       Loss of liveliness by a previously alive writer
·       Re-assertion of liveliness on a previously lost writer
·       Normal deletion of an alive writer
·       Normal deletion of a not-alive writer
·       Assertion of liveliness on a new writer
·       A new writer is discovered (i.e. on_publication_match) but its liveliness has not yet been asserted


The specification is also not clear about the usage of a DataReader's LIVELINESS lease_duration it is not clear whether this field is used solely for QoS compatibility comparison with matching remote writers or if it is also the rate at which the reader will update its LivelinessChangedStatus.


Proposed Resolution:


Change "active" to "alive" and "inactive" to "not_alive" in the LivelinessChangedStatus field names.


In response to the list of events above:
·       Previously alive writer is lost: alive_count_change == -1, not_alive_count_change = 1
·       Lost writer re-asserts liveliness: alive_count_change == 1, not_alive_count_change == -1
·       Normal deletion of alive writer: alive_count_change == -1, not_alive_count_change == 0
·       Normal deletion of not alive writer: alive_count_change == 0, not_alive_count_change == -1
·       New writer asserts liveliness for first time: alive_count_change == 1, not_alive_count_change == 0
·       New writer but hasn't yet asserted liveliness: LivelinessChangedStatus is not changed


Specify that the information communicated by a reader's LivelinessChangedStatus is out of date by no more than a lease_duration. That is, the reader commits to update its LivelinessChangedStatus if necessary at least once during its lease_duration, although it may update more often if it chooses.


Proposed Revised Text:


Add an additional paragraph to the end of section 2.1.3.10 LIVELINESS:


The information communicated by a DataReader's LivelinessChangedStatus is out of date by no more than a single lease_duration. That is, the reader commits to updating its LivelinessChangedStatus if necessary at least once during each lease_duration, although it is permitted to update more often.


Change active_count to alive_count, inactive_count to not_alive_count, active_count_change to alive_count_change, and inactive_count_change to not_alive_count_change in figure 2-13 on page 2-117.


The rows for the LivelinessChangedStatus fields in the table on page 2-118 should be as follows:


alive_count     The total number of currently active DataWriters that write the Topic read by the DataReader. This count increases when a newly matched DataWriter asserts its liveliness for the first time or when a DataWriter previously considered to be not alive reasserts its liveliness. The count decreases when a DataWriter considered alive fails to assert its liveliness and becomes not alive, whether because it was deleted normally or for some other reason. 


not_alive_count The total count of currently DataWriters that write the Topic read by the DataReader that are no longer asserting their liveliness. This count increases when a DataWriter considered alive fails to assert its liveliness and becomes not alive for some reason other than the normal deletion of that DataWriter. It decreases when a previously not alive DataWriter either reasserts its liveliness or is deleted normally.


alive_count_change      The change in the alive_count since the last time the listener was called or the status was read.


not_alive_count_change  The change in the not_alive_count since the last time the listener was called or the status was read.


Change active_count to alive_count, inactive_count to not_alive_count, active_count_change to alive_count_change, and inactive_count_change to not_alive_count_change in the IDL PSM on page 2-141.

The specification does not state whether the LivelinessLostStatus should be considered changed (and the on_liveliness_lost listener callback called) once-when the writer first lost its liveliness-or whether should it be called after every period in which the writer fails to assert its liveliness. For example, if a writer with liveliness set to MANUAL_BY_TOPIC doesn't write for two LIVELINESS lease_duration periods, should the writer listener's on_liveliness_lost callback be called once per lease_duration, or should the callback be called only once after the first lease_duration?


The analogous ambiguity exists with respect to the *DeadlineMissedStatuses.


Proposed Resolution:


The cases are somewhat different in that the deadline is under the application's control while a loss of liveliness is not (e.g. it may occur as a result of a network failure). Therefore, the *DeadlineMissed statuses should be considered changed (and the listeners invoked) at the end of every deadline period. The LivelinessLostStatus, on the other hand, should be considered changed only when a writer's state changes from alive to not alive, not after every lease_duration period thereafter.


Proposed Revised Text:


Change the description in the RequestedDeadlineMissed total_count row of the table in 2.1.4.1 (page 2-118) to read: "Total cumulative number of missed deadlines detected for any instance read by the DataReader. Missed deadlines accumulate; that is, each deadline period the total_count will be incremented by one for each instance for which data was not received."


Change the description in the LivelinessLostStatus total_count row of the table in 2.1.4.1 (page 2-119) to read: "Total cumulative number of times that a previously-alive DataWriter became not alive due to a failure to actively signal its liveliness within its offered liveliness period. This count does not change when an already not alive DataWriter simply remains not alive for another liveliness period."


Change the description in the OfferedDeadlineMissed total_count row of the table in 2.1.4.1 (page 2-119) to read: "Total cumulative number of offered deadline periods elapsed during which a DataWriter failed to provide data. Missed deadlines accumulate; that is, each deadline period the total_count will be incremented by one."

The specification states that before an entity is enabled, the only operations that can be invoked on it are get/set listener, get/set QoS, get_statuscondition, and factory methods. This list is unnecessarily restrictive.


Proposed Resolution:


The following operations should also be allowed:
·       TopicDescription::get_name
·       TopicDescription::get_type_name
·       DomainParticipant::lookup_topicdescription
·       Publisher::lookup_datawriter
·       Subscriber::lookup_datareader
·       Entity::get_status_changes and all get_*_status operations. Note that no status is considered 'triggered' when an Entity is disabled.
·       All get_/set_default_*_qos operations


Proposed Revised Text:


Revise the fourth paragraph of section 2.1.2.1.1.7 enable to read:
If an Entity has not yet been enabled, the following operations may be invoked on it in general:
·       Operations to set or get an Entity's QoS policies (including default QoS policies) and listener
·       get_statuscondition
·       'factory' operations
·       get_status_changes and other get status operations (although no status of a disabled entity is ever considered changed)
·       'lookup' operations


Other operations may explicitly state that they may be called on disabled entities; those that do not will return the error NOT_ENABLED.


Add the following sentence to sections 2.1.2.3.1.2 (TopicDescription::get_type_name) and 2.1.2.3.1.3 (TopicDescription::get_name): "This operation may be invoked on a Topic that is not yet enabled or on a ContentFilteredTopic or MultiTopic based on such a Topic."

The specification states that the default value of the RELIABILITY QoS policy on a DataWriter is BEST_EFFORT; however this makes it automatically incompatible with readers that request a RELIABLE value. This situation is not a problem per se, but it means that applications desiring RELIABLE communications must change the default configuration in two places: both with the reader and with the writer.


Proposed Resolution:


Changing the default value-on the DataWriter only-to RELIABLE would make the initial configuration of DDS applications simpler. The default behavior would still be the same because the DataReader would still default to BEST_EFFORT and therefore the default communication would be BEST_EFFORT. However, applications desiring a RELIABLE setting would have to change the defaults in only one place: with the DataReader.


Proposed Revised Text:


Append the following sentence to the "Meaning" column of the RELIABILITY RELIABLE row of the table in 2.1.3: "This is the default value for DataWriters."


The final sentence in the "Meaning" column of the RELIABILITY BEST_EFFORT row of the table in 2.1.3 currently states: "This is the default value." This sentence should be amended: "This is the default value for DataReaders and Topics."

The description of the DomainParticipant::create_topic operation in section 2.1.2.2.1.5 states that if an existing topic is found with the same name and QoS, that Topic will be returned; no duplicate Topic will be created. However, the specification fails to describe what will happen in the event that the name and QoS match but the listener is different. Additionally, the behavior places a barrier of understanding before the user, because create_topic behaves differently from all other factory methods in this respect.


Proposed Resolution:


Revise the specification to remove the language about reusing Topics. The create_topic operation, like all other 'create' operations in the specification, should always return a new Topic.


Proposed Revised Text:


Section 2.1.2.2.1.5 contains the following paragraphs; they should both be stricken from the specification:


The implementation of create_topic will automatically perform a lookup_topicdescription for the specified topic_name. If a Topic is found, then the QoS and type_name of the found Topic are matched against the ones specified on the create_topic call. If there is an exact match, the existing Topic is returned. If there is no match the operation will fail. The consequence is that the application can never create more than one Topic with the same topic_name per DomainParticipant. Subsequent attempts will either return the existing Topic (i.e., behave like find_topic) or else fail.


If a Topic is obtained multiple times by means of a create_topic, it must also be deleted that same number of times using delete_topic.

The Publisher entity has operations begin_coherent_changes and end_coherent_changes that allow groups of updates to be received by subscriptions as if they were a single update. Although the specification already contains a general statement about receivers not making updates available until all have been received, no specific mention of communication interruptions or configuration changes is made. This omission has caused questions to be raised with regards to the interactions between coherent changes and partitions, late-joining DataReaders, and network failures.


Proposed Resolution:


The specification should be amended to state that a Publisher should not prevent users from changing its partitions while it is in the middle of publishing a set of coherent changes, as the effect of doing so is no different than that of any other connectivity change. However, in the event that connectivity changes occur between the publishers and receivers of data such that some receiver is not able to obtain the entire set, that receiver must act as if it had received none of the data.


Proposed Revised Text:


Append the following text to the second paragraph of section 2.1.2.4.1.10 begin_coherent_changes:


A connectivity change may occur in the middle of a set of coherent changes; for example, the set of partitions used by the Publisher or one of its Subscribers may change, a late-joining DataReader may appear on the network, or a communication failure may occur. In the event that such a change prevents an entity from receiving the entire set of coherent changes, that entity must behave as if it had received none of the set.

The table in 2.1.5 says that built-in DataReaders should have TRANSIENT durability. However, the description of that durability states that support for it is optional.


Proposed Resolution:


The specification should be changed to state that built-in readers should have TRANSIENT_LOCAL durability.


Proposed Revised Text:


Change TRANSIENT to TRANSIENT_LOCAL in the DURABILITY row of the table on page 2-129.

The specification does not explicitly state whether clients of the built-in DataReaders should be able to discover other entities that belong to the same participant by those means. In other words, if a DataReader 'A' belongs (indirectly) to a DomainParticipant 'B', will information about A appear when one reads from the subscription built-in reader of B?


We believe that most users will not want to "discover" entities they created themselves; the purpose of the built-in entities is to discover what exists elsewhere on the network. Furthermore, there is currently no way for a client of the built-in reader to distinguish between entities belonging to its own DomainParticipant and those that exist elsewhere on the network.


Proposed Resolution:


Clarify the descriptions of the built-in topics to indicate that data pertaining to entities of the same participant will not be made available there.


A mechanism to determine whether an instance handle (read from a built-in topic or obtained through any other means) represents a particular known entity is generally useful. Add the following operations:
·       InstanceHandle_t Entity::get_instance_handle()
·       boolean DomainParticipant::contains_entity(InstanceHandle_t a_handle)


Proposed Revised Text:


Add the following sentence to the end of the first paragraph on page 2-129:


A built-in DataReader object obtained from a given participant will not provide data pertaining to other entities created (directly or indirectly) from that participant under the assumption that such objects are already known to the application.


Add the following row to the Entity Class table in section 2.1.2.1.1:


get_instance_handle             InstanceHandle_t


Add the description of the new operation as a new section:


2.1.2.1.1.8 get_instance_handle


Get the instance handle that represents the Entity in the built-in topic data, in various statuses, and elsewhere.


Add the following row to the DomainParticipant Class table in section 2.1.2.2.1:
contains_entity         boolean
        a_handle        InstanceHandle_t


Add the description of the new operation as a new section:


2.1.2.2.1.26 contains_entity
This operation checks whether or not the given instance handle represents an entity that was created, directly or indirectly, from the DomainParticipant. The instance handle for an Entity may be obtained from built-in topic data, from various statuses, or from the Entity operation get_instance_handle.


Add the new operations to the IDL PSM in section 2.2.3:


interface Entity {
    InstanceHandle_t get_instance_handle();
};


interface DomainParticipant : Entity {
    boolean contains_entity(InstanceHandle_t a_handle);
};

This issue subsumes two related issues.


·       Presumably, listener callbacks pertaining to built-in entities should fall back to the DomainParticipantListener of their containing DomainParticipant in the usual way in the event that those built-in entities have not requested to receive the callbacks themselves. However, this behavior may prove inconvenient in practice: users-even those completely uninterested in built-in entities-must recognize the callbacks pertaining to those entities and deal with them in some way whenever they install a participant listener. Implementers are also constrained, as they will find it difficult to ensure the correct listener behavior while preserving the freedom to create built-in entities on demand.


·       The specification does not state the behavior of installing a nil listener or what mask values are acceptable in that case.
Proposed Resolution:


Installing a nil listener should be equivalent to installing a listener that does nothing. It is acceptable to provide a mask with a nil listener; in that case, no callback will be delivered to the entity or to its containing entities.


A DomainParticipant's built-in Subscriber and all of its built-in Topics should by default have nil listeners with all mask bits set. Therefore their callbacks will no propagate back to the DomainParticipantListener unless the user explicitly calls set_listener on them.


Proposed Revised Text:


Insert a new paragraph after the existing first paragraph of section 2.1.2.1.1.3 set_listener:


It is permitted to set a nil listener with any listener mask; it is behaviorally equivalent to installing a listener that does nothing.


Append a new sentence to the final bullet in the list in section 2.1.4.3.1:


Any statuses appearing in the mask associated with a nil listener will neither be dispatched to the entity itself nor propagated to its containing entities.


Insert the following paragraph immediately following the table of built-in entity QoS on page 2-129:


Built-in entities have default listener settings as well. A DomainParticipant's built-in Subscriber and all of its built-in Topics have nil listeners with all statuses appearing in their listener masks. The built-in DataReaders have nil listeners with no statuses in their masks.

There is already a convention in the specification of mapping an out parameter in the PIM to an inout parameter in the IDL PSM. This convention is useful because it preserves more precise semantics in the PIM while allowing for more performant implementations in language PSMs based on the IDL PSM. However, the convention is never explicitly described in the specification, which could lead to confusion among readers.


Proposed Resolution:


The section 2.2.2 PIM to PSM Mapping Rules should explicitly describe and endorse the aforementioned convention.


Proposed Revised Text:


Insert a new paragraph after the current first paragraph in section 2.2.2:
'Out' parameters in the PIM are conventionally mapped to 'inout' parameters in the PSM in order to minimize the memory allocation performed by the Service and allow for more efficient implementations. The intended meaning is that the caller of such an operation should provide an object to serve as a "container" and that the operation will then "fill in" the state of that object appropriately.

In most cases in the specification, when constants of a type named like <something>Kind need to be combined together, a type <something>Mask is defined in the IDL PSM in addition to <something>Kind. The case of StatusKind is inconsistent, however: its mask type is called StatusKindMask, not StatusMask.


Proposed Resolution:


Replace StatusKindMask with StatusMask. Clarify the name mapping convention in section 2.2.2.


Proposed Revised Text:


Append the following sentence to the fourth paragraph of section 2.2.2: "The name of the mask type is formed by replacing the word 'Kind' with the word 'Mask'."


Replace "StatusKindMask" with "StatusMask" everywhere it appears in the IDL PSM in section 2.2.3.

I think the following sentence is incorrect: a Listener is used to provide a callback for synchronous access and a WaitSet associated with one or several Condition objects as far as I can tell, these roles should be reversed. There are a bunch of other bugs in the spec. I'll try to report them as time permits.

ummary:
According to the PIM, get get_qos() method returns the QosPolicy [ ].  According to the PSM, the qos is a parameter and the 

method returns void.


Proposed Resolution:
The PIM should be updated to be consistent with the PSM.
In addition, the return value in both the PIM and PSM should be changed from void to ReturnCode_t.


Proposed Revised Text:


Section 2.1.2.1.1 Entity Class; Entity class table
Change row from:
abstract get_qos                    QosPolicy []
To
abstract get_qos                    ReturnCode_t
                  out: qos_list     QosPolicy[]


Section 2.1.2.2.1 Domain Module; DomainParticipant class table
Change row from:
abstract get_qos                    QosPolicy []
To
abstract get_qos                    ReturnCode_t
                  out: qos_list     QosPolicy[]


Section 2.1.2.3.1 TopicDescription Class; Topic class table
Change row from:
abstract get_qos                    QosPolicy []
To
abstract get_qos                    ReturnCode_t
                  out: qos_list     QosPolicy[]


Section 2.1.2.4.1 Publisher Class; Publisher class table
Change row from:
abstract get_qos                    QosPolicy []
To
abstract get_qos                    ReturnCode_t
                  out: qos_list     QosPolicy[]


Section 2.1.2.4.2 DataWriter Class; DataWriter class table
Change row from:
abstract get_qos                    QosPolicy []
To
abstract get_qos                    ReturnCode_t
                  out: qos_list     QosPolicy[]


Section 2.1.2.5.2 Subscriber Class; Subscriber class table
Change row from:
abstract get_qos                    QosPolicy []
To
abstract get_qos                    ReturnCode_t
                  out: qos_list     QosPolicy[]


Section 2.1.2.5.3 DataReader Class; DataReader class table
Change row from:
abstract get_qos                    QosPolicy []
To
abstract get_qos                    ReturnCode_t
                  out: qos_list     QosPolicy[]


Section 2.2.3 DCPS  PSM : IDL
interface Entity
Change:
// void get_qos(inout EntityQos qos);
To
// ReturnCode_t get_qos(inout EntityQos qos);

The PIM should be updated to be consistent with the PSM.
In addition, the return value in both the PIM and PSM should be changed from void to ReturnCode_t..

Summary:
In the PSM it is returning void.  However, in the PIM it is returning ReturnCode_t.  Also, all other get_defatult_xxx_qos() 

methods return ReturnCode_t in both the PIM and the PSM.


Proposed Resolution:
The return code should be changed to ReturnCode_t in the PSM.


Proposed Revised Text:


Section 2.2.3 DCPS PSM : IDL
interface Publisher :
Replace
  void get_default_datawriter_qos(inout DataWriterQos qos);
With
  ReturnCode_t get_default_datawriter_qos(inout DataWriterQos qos);

Summary:
The string sequence parameter in the get_expression_parameters() method of the ContentFilteredTopic and MultiTopic and in the 

get_query_parameters() method of the QueryCondition are all listed as the return value in both the PIM and PSM.
It is desirable for the string sequence to be used as a parameter for consistency and to allow for an error return.


Proposed Resolution:
The PIM and the PSM should have the string sequence as a parameter and the methods should return ReturnCode_t.


Proposed Revised Text:


Section 2.1.2.3.3 ContentFilteredTopic class; ContentFilteredTopic class table
Change row from:
  get_expression_parameters                   string[]
To
  get_expression_parameters                   ReturnCode_t
              inout: expression_parameters    string[]


Section 2.1.2.3.4 MultiTopic Class [optional]
Change row from:
  get_expression_parameters                   string[]
To
  get_expression_parameters                   ReturnCode_t
              inout: expression_parameters    string[]


Section 2.2.3 DCPS PSM : IDL


interface ContentFilteredTopic
Replace:
  StringSeq get_expression_parameters();
With:
  ReturnCode_t get_expression_parameters(inout StringSeq expression_parameters);


interface MultiTopic
Replace:
  StringSeq get_expression_parameters();
With:
  ReturnCode_t get_expression_parameters(inout StringSeq expression_parameters);

The PIM and the PSM should have the string sequence as a parameter and the methods should return ReturnCode_t.

Title:  R#4 Mention of get_instance() operation on the DomainParticipantFactory being static in the wrong section


Summary:
The last paragraph of section 2.1.2.2.2.4 (lookup_participant) mentioning that get_instance() is a static operation probably belongs in the preceding section 2.1.2.2.2.3 (get_instance).


Proposed Resolution:
Move the paragraph to the correct section


Proposed Revised Text:


Section 2.1.2.2.2.4 lookup_participant
Remove the last paragraph:
The get_instance operation is a static operation implemented using the syntax of the native language and can therefore not be expressed in the IDL PSM.


Section 2.1.2.2.2.3 get_instance
Add the paragraph removed from above:
The get_instance operation is a static operation implemented using the syntax of the native language and can therefore not be expressed in the IDL PSM.

Summary:
In the PIM, all get_XXX_status() methods return the relevant status by value.  This does not allow for an error return and is inconsistent with other operations that accept a parameter.
The same is true for the PSM except for get_inconsistent_topic_status() on the Topic which returns ReturnCode_t and the status is a parameter.



Proposed Resolution:
In the PIM and the PSM, the operations should return ReturnCode_t with the status as a parameter.


Proposed Revised Text:


Section 2.1.2.3.2 Topic Class; Replace
  get_inconsistent_topic_status                                 InconsistentTopicStatus
With
  get_inconsistent_topic_status                                 ReturnCode_t 
                                    inout: status               InconsistentTopicStatus
Section 2.1.2.4.2 DataWriter Class; 
Replace
  get_liveliness_lost_status                                    LivelinessLostStatus
  get_offered_deadline_missed_status                            OfferedDeadlineMissedStatus
  get_offered_incompatible_qos_status                           OfferedIncompatibleQosStatus
  get_publication_match_status                                  PublicationMatchedStatus
With
  get_liveliness_lost_status                                    ReturnCode_t
                                              inout: status     LivelinessLostStatus
  get_offered_deadline_missed_status                            ReturnCode_t
                                              inout: status     OfferedDeadlineMissedStatus
  get_offered_incompatible_qos_status                           ReturnCode_t
                                              inout: status     OfferedIncompatibleQosStatus
  get_publication_match_status                                  ReturnCode_t
                                              inout: status     PublicationMatchedStatus
Section 2.1.2.5.2 Subscriber Class;
Replace
  get_sample_lost_status                                        SampleLostStatus
With
  get_sample_lost_status                                        ReturnCode_t 
                                              inout: status     SampleLostStatus
Section 2.1.2.5.3 DataReader Class; 
Replace
  get_liveliness_changed_status                                 LivelinessChangedStatus
  get_requested_deadline_missed_status                          RequestedDeadlineMissedStatus
  get_requested_incompatible_qos_status                         RequestedIncompatibleQosStatus
  get_sample_rejected_status                                    SampleRejectedStatus
  get_subscription_match_status                                 SubscriptionMatchedStatus
With
  get_liveliness_changed_status                                 ReturnCode_t 
                                              inout: status     LivelinessChangedStatus
  get_requested_deadline_missed_status                          ReturnCode_t
                                              inout: status     RequestedDeadlineMissedStatus
  get_requested_incompatible_qos_status                         ReturnCode_t
                                              inout: status     RequestedIncompatibleQosStatus
  get_sample_rejected_status                                    ReturnCode_t       
                                              inout: status     SampleRejectedStatus
  get_subscription_match_status                                 ReturnCode_t    
                                              inout: status     SubscriptionMatchedStatus
Section 2.2.3 DCPS PSM : IDL


interface DataWriter; Replace:
  LivelinessLostStatus get_liveliness_lost_status();
  OfferedDeadlineMissedStatus get_offered_deadline_missed_status();
  OfferedIncompatibleQosStatus get_offered_incompatible_qos_status();
  PublicationMatchedStatus get_publication_match_status();
With
  ReturnCode_t get_liveliness_lost_status(inout LivelinessLostStatus status);
  ReturnCode_t get_offered_deadline_missed_status(inout OfferedDeadlineMissedStatus status);
  ReturnCode_t get_offered_incompatible_qos_status(inout OfferedIncompatibleQosStatus status);
  ReturnCode_t get_publication_match_status(inout PublicationMatchedStatus status);


interface DataReader; Replace:
  SampleRejectedStatus get_sample_rejected_status();
  LivelinessChangedStatus get_liveliness_changed_status();
  RequestedDeadlineMissedStatus get_requested_deadline_missed_status();
  RequestedIncompatibleQosStatus get_requested_incompatible_qos_status();
  SubscriptionMatchedStatus get_subscription_match_status();
  SampleLostStatus get_sample_lost_status();
With:
  ReturnCode_t get_sample_rejected_status( inout SampleRejectedStatus status );
  ReturnCode_t get_liveliness_changed_status(inout LivelinessChangedStatus status);
  ReturnCode_t get_requested_deadline_missed_status(inout RequestedDeadlineMissedStatus status);
  ReturnCode_t get_requested_incompatible_qos_status(inout RequestedIncompatibleQosStatus status);
  ReturnCode_t get_subscription_match_status(inout SubscriptionMatchedStatus status);
  ReturnCode_t get_sample_lost_status(inout SampleLostStatus status);

In the PIM and the PSM, the operations should return ReturnCode_t with the status as an out parameter.

Summary:
We have REJECTED_BY_SAMPLES_LIMIT which comes from the max_samples in the ResourceLimitsQosPolicy.
However, we have REJECTED_BY_INSTANCE_LIMIT which comes from the max_instances.


Proposed Resolution:
It should be named REJECTED_BY_INSTANCES_LIMIT.


Proposed Revised Text:


Section 2.2.3 DCPS PSM : IDL
enum SampleRejectedStatusKind; Replace
  REJECTED_BY_INSTANCE_LIMIT
With
  REJECTED_BY_INSTANCES_LIMIT

Summary:
The OWNERSHIP_STRENGTH QoS only applies to DataWriters, yet it is listed in the table of the QoS of the built-in Subscriber and DataReader objects in Section 2.1.5.


Proposed Resolution:
  Remove OWNERSHIP_STRENGTH from the aforementioned table.


Proposed Revised Text:


Section 2.1.5
In the table that follows the sentence:
The QoS of the built-in Subscriber and DataReader objects is given by the following table:
Remove the row for 'OWNERSHIP_STRENGTH'

Summary:
In the description of the TIME_BASED_FILTER QoS, we are missing the description of the consistency requirements with the DEADLINE QoS, which is mentioned in the table in Section 2.1.3.
Also, we should mention some consistency requirements between max_samples and max_samples_per_instance within the RESOURCE_LIMITS QoS.


Proposed Resolution:
In Section 2.1.3.12 on the TIME_BASED_FILTER QoS we should make explicit mention that the minimum_separation must be <= the period of the DEADLINE QoS.
In both the table in Section 2.1.3 and in Section 2.1.3.22 on the RESOURCE_LIMITS QoS we should mention the consistency requirements that max_samples >= max_samples_per_instance.


Proposed Revised Text:


Section 2.1.3.12 TIME_BASED_FILTER; 
Add the following paragraph to the end of the section:


The setting of the TIME_BASED_FILTER policy must be set consistently with that of the DEADLINE policy. For these two policies to be consistent the settings must be such that "deadline period>= minimum_separation." An attempt to set these policies in an inconsistent manner will cause the INCONSISTENT_POLICY status to change and any associated Listeners/WaitSets to be triggered.


Section 2.1.3.22 RESOURCE_LIMITS
Add the following paragraph before the last paragraph in the section:


The setting of RESOURCE_LIMITS max_samples must be consistent with the setting of the max_samples_per_instance. For these two values to be consistent they must verify that max_samples >= max_samples_per_instance.


Section 2.1.3.22 RESOURCE_LIMITS
Add the following paragraph at the end of the section:


An attempt to set these policies in an inconsistent manner will cause the INCONSISTENT_POLICY status to change and any associated Listeners/WaitSets to be triggered.

In Section 2.1.3.12 on the TIME_BASED_FILTER QoS we should make explicit mention that the minimum_separation must be <= the period of the DEADLINE QoS.
In both the table in Section 2.1.3 and in Section 2.1.3.22 on the RESOURCE_LIMITS QoS we should mention the consistency requirements that max_samples >= max_samples_per_instance. 

Blocking of write() call depending on RESOURCE_LIMITS, HISTORY, and RELIABILITY QoS


Summary:
Section 2.1.2.4.2.11 states that even writers with KEEP_LAST HISTORY QoS can block and describes some scenarios.
Some of these scenarios may no longer be valid depending on whether the implementation is willing to sacrifice reliability.


In the table in Section 2.1.3, it states the max_blocking _time in the RELIABILITY QoS only applies for RELIABLE and KEEP_ALL HISTORY QoS.
In Section 2.1.3.14 it is only mentioned that the writer can block if the RELIABILITY QoS is set to RELIABLE.


Proposed Resolution:
At the very least, remove mention of the requirement that the HISTORY QoS be KEEP_ALL for blocking to apply in the table in Section 2.1.3.


Proposed Revised Text:


Section 2.1.3 QoS Table
On the entry for the RELIABILITY QoS max_blocking_time
Replace:
  This setting applies only to the case where kind=RELIABLE and the HISTORY is KEEP_ALL.
With:
  This setting applies only to the case where kind=RELIABLE.

Remove mention of the requirement that the HISTORY QoS be KEEP_ALL for blocking to apply in the table in Section 2.1.3.

Summary:
In the table in Section 2.1.3, the default partition value is said to be a zero-length sequence, which "is equivalent to a sequence containing a single element consisting of an empty string", which will match any partition.  However, if an empty string will match any partition, it is not consistent with normal regular expression matching.


Proposed Resolution:
It is desirable to have the behavior in that if a special partition is specified, it will only match others who have that special partition.  If the default behavior is that it will match all partitions, there is no way for a newly created entity to prevent others from matching it, unless the special partition is used.
Therefore, we should not overload the meaning of the empty string to mean matching everything.  Instead, the empty string is the default partition.  An empty partition sequence or a partition sequence that consists of wildcards only will automatically be assumed to be in the default empty string partition.


Proposed Revised Text:


Section 2.1.3 Supported QoS PARTITION Table
On the "Meaning" Column for the PARTITION QoS; 


Replace the following paragraph:


The default value is an empty (zero-length) sequence. This is treated as a special value that matches any partition. And is equivalent to a sequence containing a single element consisting of the empty string.


With


The empty string ("") is considered a valid partition that is matched with other partition names using the same rules of string matching and regular-expression matching used for any other partition name (see Section 2.1.3.13)
The default value for the PARTITION QoS is a zero-length sequence. The zero-length sequence is treated as a special value equivalent to a sequence containing a single element consisting of the empty string.

It is desirable to have the behavior in that if a special partition is specified, it will only match others who have that special partition.  If the default behavior is that it will match all partitions, there is no way for a newly created entity to prevent others from matching it, unless the special partition is used.
Therefore, we should not overload the meaning of the empty string to mean matching everything.  Instead, the empty string is the default partition.  An empty partition sequence or a partition sequence that consists of wildcards only will automatically be assumed to be in the default empty string partition.
Also in Section 2.1.3.13 PARTITIOIN, the "connection" between a reader and writer is described as an "association". The correct term used elsewhere in the spec is "match".  Therefore the use of "association" in this section should be replaced with the term "match".

Summary:
In the table in Section 2.1.5,  for both the DCPSPublication and DCPSSubscription there is a typo in that "ownershiph" should be "ownership".
Also, the destination_order row in the DCPSPublication should be of type "DesinationOrderQosPolicy" and not "QosPolicy".
Also, the presentation row in the DCPSPublication should be of type "PresentationQosPolicy" and not "DestinationOrderQosPolicy".
Also, in the paragraph at the top of the page containing the table there is a typo where "crated" should be "created".


Proposed Resolution:
Fix the typos.


Proposed Revised Text:


Section 2.1.5,  2 paragraphs above the Builtin-Topic table; at the end of the paragraph:
Replace "crated" with "created" in the sentence:
"application that crated them."


Section 2.1.5 Builtin-Topic table; 
Replace DCPSPublication fieldname 'ownershiph' with 'ownership'
Replace DCPSSubscription fieldname 'ownershiph' with 'ownership'
Replace the type of the DCPSPublication, destination_order field from 'QosPolicy" to "DestinationOrderQosPolicy"
Replace the type of the DCPSPublication  presentation field from 'DestinationOrderQosPolicy" to "PresentationQosPolicy

The method name is get/set_expression_parameters() whereas the parameter passed in is the "filter_parameters".  Understandably the full name is filter expression parameters since the ContentFilteredTopic has a "filter_expression" attribute.
Compare this with the MultiTopic which has the same named methods which take in "expression_parameters" and has a "subscription_expression" attribute.
The name "filter_parameters" is also used in the create_contentfilteredtopic() method on the DomainParticipant.


Proposed Resolution:
Change the name of "filter_parameters" to "expression_parameters" for more consistency.


Proposed Revised Text:


Section 2.1.2.2.1 DomainParticipant Class; DomainParticipant class table
On the row describing the operation "create_contentfilteredtopic" 
Replace parameter name "filter_ parameters"
With parameter name "expression_ parameters"


Section 2.1.2.2.1.7 create_contentfilteredtopic
Last paragraph replace  "filter_ parameters" with "expression_ parameters"


Section 2.1.2.3.3 ContentFilteredTopic Class; ContentFilteredTopic class table
On the row describing the operation "set_expression_parameters" 
Replace parameter name "filter_ parameters"
With parameter name "expression_ parameters"


Section 2.1.2.3.3 ContentFilteredTopic Class
On the second bullet towards the end of the section:
Replace  "filter_ parameters" with "expression_ parameters"
On the last paragraph just above section 2.1.2.3.3.1:
Replace  "filter_ parameters" with "expression_ parameters"


Section 2.1.2.3.3.3 get_expression_parameters
On the first paragraph:
Replace  "filter_ parameters" with "expression_ parameters"


Section 2.1.2.3.3.4 set_expression_parameters
On the first paragraph:
Replace  "filter_ parameters" with "expression_ parameters"


Section 2.2.3 DCPS PSM : IDL 
interface DomainParticipant
On the operation create_contentfilteredtopic
Replace formal parameter name "filter_ parameters" with "expression_ parameters"

Change the name of "filter_parameters" to "expression_parameters" for more consistency.

Incorrect prototype for the FooDataWriter method register_instance_w_timestamp() in the PSM 


Summary:
The handle is incorrectly a parameter when it is already the return.


Proposed Resolution:
Remove the incorrect handle parameter.


Proposed Revised Text:


Section 2.2.3 DCPS PSM : IDL 
interface FooDataWriter
On the register_instance_w_timestamp remove the parameter 
"in DDS::InstanceHandle_t handle,"


The resulting operation is:
DDS::InstanceHandle_t register_instance_w_timestamp(in Foo instance_data, in DDS::Time_t source_timestamp);

In the third paragraph of Section 2.1.3, it is stated that "some QosPolicy values may not be compatible with other ones".  In this context we are really talking about the consistency of related QosPolicies as compatibility is already a concept concerning requested/offered semantics.


Proposed Resolution:
Reword the sentence to use the term "consistency" which is already used later in the paragraph.


Proposed Revised Text:


Section 2.1.3 Supported QoS
3rd paragraph 
Replace "compatible" with "consistent" in the sentence:
  "Some QosPolicy values may not be compatible with other ones."
Resulting in:
  "Some QosPolicy values may not be consistent with other ones."

Reword the sentence to use the term "consistency" which is already used later in the paragraph

Summary:
In Section 2.1.3.7 concerning the DEADLINE QoS, it is stated that if the QoS is set inconsistently, i.e. period is < minimum_separation of the TIME_BASED_FILTER QoS, the INCONSISTENT_POLICY status will change and any associated Listeners/WaitSets will be triggered.
There is no such status.  Instead the set_qos() operation will error with return code INCONSISTENT_POLICY.


Proposed Resolution:
Mention the return code instead.


Proposed Revised Text:


Section 2.1.3.7 DEADLINE
Remove the last sentence in the section:
"An attempt to set these policies in
an inconsistent manner will cause the INCONSISTENT_POLICY status to change and any associated Listeners/WaitSets to be triggered."

Summary:
In Section 2.1.3.11 (LIVELINESS QoS) the second condition for compatibility uses "=<" for less than or equal to where "<=" might be more readable.
Also, the last paragraph states "equal or greater to" where "equal or greater than" might be more readable.
In next to last paragraph of Section 2.1.3.14 (RELIABILITY QoS), there is a typo where "change form a newer value" should be "change from a newer value".
In Section 2.1.3.22 (READER_DATA_LIFECYCLE QoS) the last two paragraphs mention how "view_state becomes NOT_ALIVE_xxx" where it should be the "instance_state".


Proposed Resolution:
Make the aforementioned changes


Proposed Revised Text:


Section 2.1.3.11 LIVELINESS
Second bullet in the enumeration near the end of the section:
Replace "offered lease_duration =< requested lease_duration"
With "offered lease_duration <= requested lease_duration"


Section 2.1.3.11 LIVELINESS
Last paragraph; replace:
  "Service with a time-granularity equal or greater to the lease_duration."
With:
  "Service with a time-granularity greater  or equal to the lease_duration."


Section 2.1.3.14 RELIABILITY
Next to last paragraph. Raplace:
  "change form a newer value"
With:
  "change from a newer value".


Section 2.1.3.22 READER_DATA_LIFECYCLE
Paragraph before the last 
Replace "view_state" with "inatance_state" in:
"maintain information regarding an instance once its view_state becomes NOT_ALIVE_NO_WRITERS."


Section 2.1.3.22 READER_DATA_LIFECYCLE
Last paragraph:
Replace "view_state" with "inatance_state" in:
"maintain information regarding an instance once its view_state becomes NOT_ALIVE_DISPOSED."

Summary:
In Section 2.1.2.4.1.10 (begin_coherent_changes) there is a typo in the last sentence of the section where "if may be useful" should be "it may be useful".
In the second paragraph of Section 2.1.2.2.2.4 (lookup_participant) there is a typo where "multiple DomainParticipant" should be "multiple DomainParticipants".


Proposed Resolution:
Make the suggested corrections.


Proposed Revised Text:


Section 2.1.2.4.1.10 begin_coherent_changes 
Last sentence, replace:
  "if may be useful"
With
  "it may be useful"


Section 2.1.2.2.2.4 lookup_participant
Second paragraph replace
  "If multiple DomainParticipant belonging"
With
  "If multiple DomainParticipant entities belonging"

First typo "noe" is invalid. Must was already fixed in the last revision.
Otherwise, make the suggested corrections.

Summary:
In Section 2.1.3.9 in the paragraph dealing with when there are multiple same-strength writers, the next to last sentence describes that the owner must remain the same until one of several conditions are met.
The condition where "a new DataWriter with the same strength that should be deemed the owner according to the policy of the Service" should be explicitly mentioned although it may have been implied.


Proposed Resolution:
Add the explicit mention of the additional condition above.


Proposed Revised Text:


Section 2.1.3.9.2 EXCLUSIVE kind


5th paragraph; replace the sentence:
It is also required that the owner remains the same until there is a change in strength, liveliness, the owner misses a deadline on the instance, or a new DataWriter with higher strength modifies the instance.


With:
It is also required that the owner remains the same until there is a change in strength, liveliness, the owner misses a deadline on the instance, a new DataWriter with higher strength modifies the instance, or a new owner with the same strength that is deemed by the Service to be the owner modifies the instance.

Currently it is stated that write() and dispose() may block and return TIMEOUT when the RELIABILITY QoS kind is set to RELIABLE and any of the RESOURCE_LIMITS QoS is hit.
We should reconsider the action taken when it is instance resource limits that are hit.  If instance resources are kept around until they are unregistered (and not even yet considering how RELIABILITY or DURABILITY QoS affects this), then it seems awkward to block when the user is required to take action.  Perhaps returning immediately with OUT_OF_RESOURCES makes more sense in this situation.


Proposed Resolution:
When the writer is out of instance resources because all max_instances have been registered or written, the write/dispose() call will return OUT_OF_RESOURCES instead of blocking if it can be detected.


Proposed Revised Text:


Section 2.1.2.4.2.11 write
Above the paragraph starting with "In case the provided handle is valid"; add the paragraph:
Instead of blocking, the write operation is allowed to return immediately with the error code OUT_OF_RESOURCES provided the following two conditions are met:
1. The reason for blocking would be that the RESOURCE_LIMITS are exceeded.
2. The service determines that waiting the 'max_waiting_time' has no chance of freeing the necessary resources.  For example, if the only way to gain the necessary resources would be for the user to unregister an instance.


Section 2.1.2.4.2.12 write_w_timestamp
After the paragraph "This operation may block" add the paragraph:
This operation may return OUT_OF_RESOURCES under the same circumstances described for the write operation (Section 2.1.2.4.2.11).


Section 2.1.2.4.2.13 dispose
After the paragraph "This operation may block…" add the paragraph:
This operation may return OUT_OF_RESOURCES under the same circumstances described for the write operation (Section 2.1.2.4.2.11).


Section 2.1.2.4.2.14 dispose_w_timestamp
After the paragraph "This operation may block…" add the paragraph:
This operation may return OUT_OF_RESOURCES under the same circumstances described for the write operation (Section 2.1.2.4.2.11).


Section 2.1.2.4.2.14 dispose_w_timestamp
After the paragraph "This operation may block…" add the paragraph:
This operation may return OUT_OF_RESOURCES under the same circumstances described for the write operation (Section 2.1.2.4.2.11).


Section 2.1.2.4.2.5 register


Replace the paragraph:
This operation may block if the RELIABILITY kind is set to RELIABLE and the modification would cause data to be lost or else cause one of the limits specified in the RESOURCE_LIMITS to be exceeded. Under these circumstances, the RELIABILITY max_blocking_time configures the maximum time the write operation may block (waiting for space to become available). If max_blocking_time elapses before the DataWriter is able to store the modification without exceeding the limits, the operation will fail and return TIMEOUT.


With:
This operation may block and return TIMEOUT under the same circumstances described for the write operation (Section 2.1.2.4.2.11).
This operation may return OUT_OF_RESOURCES under the same circumstances described for the write operation (Section 2.1.2.4.2.11).


Section 2.1.2.4.2.5 register_w_timestamp


Replace the paragraph:
This operation may block and return TIMEOUT under the same circumstances described for the register_instance operation (Section 2.1.2.4.2.5 ).
With:
This operation may block and return TIMEOUT under the same circumstances described for the write operation (Section 2.1.2.4.2.11).
This operation may return OUT_OF_RESOURCES under the same circumstances described for the write operation (Section 2.1.2.4.2.11).

When the writer is out of instance resources because all max_instances have been registered or written, the write/dispose() call will return OUT_OF_RESOURCES instead of blocking if it can be detected.

For XXX = participant, topic, publisher, subscriber, and datareader, the specification states "in the case where the QoS policies are not explicitly specified".
For XXX = datawriter, the specification states "in the case where the QoS policies are defaulted".
The latter is technically more correct.


Proposed Resolution:
Use the wording in set_default_datawriter_qos().


Proposed Revised Text:
Section 2.1.2.2.1.20 set_default_publisher_qos
First paragraph replace:
  in the case where the QoS policies are not explicitly specified
With
  in the case where the QoS policies are defaulted


Section 2.1.2.2.1.21 get_default_publisher_qos
First paragraph replace:
  in the case where the QoS policies are not explicitly specified
With
  in the case where the QoS policies are defaulted


Section 2.1.2.2.1.22 set_default_subscriber_qos
First paragraph replace:
  in the case where the QoS policies are not explicitly specified
With
  in the case where the QoS policies are defaulted


Section 2.1.2.2.1.23 get_default_subscriber_qos
First paragraph replace:
  in the case where the QoS policies are not explicitly specified
With
  in the case where the QoS policies are defaulted


Section 2.1.2.2.1.24 set_default_topic_qos
First paragraph replace:
  in the case where the QoS policies are not explicitly specified
With
  in the case where the QoS policies are defaulted


Section 2.1.2.2.1.25 get_default_topic_qos
First paragraph replace:
  in the case where the QoS policies are not explicitly specified
With
  in the case where the QoS policies are defaulted


Section 2.1.2.2.2.5 set_default_participant_qos
First paragraph replace:
  in the case where the QoS policies are not explicitly specified
With
  in the case where the QoS policies are defaulted


Section 2.1.2.2.2.6 get_default_participant_qos
First paragraph replace:
  in the case where the QoS policies are not explicitly specified
With
  in the case where the QoS policies are defaulted


Section 2.1.2.4.1.16 get_default_datawriter_qos
First paragraph replace:
  in the case where the QoS policies are not explicitly specified
With
  in the case where the QoS policies are defaulted


Section 2.1.2.5.2.15 set_default_datareader_qos
First paragraph replace:
  in the case where the QoS policies are not explicitly specified
With
  in the case where the QoS policies are defaulted


Section 2.1.2.5.2.16 get_default_datareader_qos
First paragraph replace:
  in the case where the QoS policies are not explicitly specified
With
  in the case where the QoS policies are defaulted

For better naming consistency with other statuses, the PUBLICATION_MATCH_STATUS and SUBSCRIPTION_MATCH_STATUS may be renamed to PUBLICATION_MATCHED_STATUS and SUBSCRIPTION_MATCHED_STATUS.  Also the get_publication_match_status and get_subscription_match_status operations may be renamed to get_publication_matched_status and get_subscription_matched_status.
In addition the callback is named on_XXX_matched.


Proposed Resolution:
Rename PUBLICATION_MATCH_STATUS to PUBLICATION_MATCHED_STATUS, SUBSCRIPTION_MATCH_STATUS to SUBSCRIPTION_MATCHED_STATUS


Proposed Revised Text:
Section 2.1.2.4 Publication Module 
Figure 2-9; DataWriter class
Rename
  get_publication_match_status()
To
  get_publication_matched_status()


Section 2.1.2.4.2 DataWriter Class
DataWriter class table 
Rename
  get_publication_match_status()
To
  get_publication_matched_status()


Section 2.1.2.4.2.19 get_publication_match_status
Rename section heading to:
2.1.2.4.2.19 get_publication_matched_status


Replace
  "allows access to the PUBLICATION_MATCH_QOS"
With:
  "allows access to the PUBLICATION_MATCHED communication status "


Section 2.1.2.5 Subscription Module 
Figure 2-9; DataReader class
Rename
  get_subscription_match_status()
To
  get_subscription_matched_status()


Section 2.1.2.4.2 DataReader Class
DataReader class table 
Rename
  get_subscription_match_status()
To
  get_subscription_matched_status()


Section 2.1.2.5.3.25 get_subscription_match_status
Rename section heading to:
  2.1.2.5.3.25 get_subscription_matched_status


Section 2.1.2.5.3.25 get_subscription_match_status
Rename "SUBSCRIPTION_MATCH_STATUS" to "SUBSCRIPTION_MATCHED_STATUS"


Section 2.1.4.4 Conditions and Wait-sets
Figure 2-19; DataReader class
Rename
  get_publication_match_status()
To
  get_publication_matched_status()


Section 2.1.4.1 Communication Status
Communication status table replace:
  PUBLICATION_MATCH
With
  PUBLICATION_MATCHED


Communication status table replace:
  SUBSCRIPTION_MATCH
With
  SUBSCRIPTION_MATCHED


Section 2.2.3 DCPS PSM : IDL
Status constants 
Replace:
  const StatusKind PUBLICATION_MATCH_STATUS = 0x0001 << 13;
  const StatusKind SUBSCRIPTION_MATCH_STATUS = 0x0001 << 14;
With
  const StatusKind PUBLICATION_MATCHED_STATUS = 0x0001 << 13;
  const StatusKind SUBSCRIPTION_MATCHED_STATUS = 0x0001 << 14;


interface DataWriter
Replace:
  PublicationMatchedStatus get_publication_match_status();
With
  PublicationMatchedStatus get_publication_matched_status();


interface DataReader
Replace:
  SubscriptionMatchedStatus get_subscription_match_status();
With
  SubscriptionMatchedStatus get_subscription_matched_status();

Rename PUBLICATION_MATCH_STATUS to PUBLICATION_MATCHED_STATUS, SUBSCRIPTION_MATCH_STATUS to SUBSCRIPTION_MATCHED_STATUS

Should delete_contained_entities() on the Subscriber (and even the DataReader or DomainParticipant) be allowed to return PRECONDITION_NOT_MET?


Summary:
As described in Section 2.1.2.5.2.6, delete_datareader() can return PRECONDITION_NOT_MET if there are any outstanding loans.  In a similar fashion, should we allow delete_contained_entities() on the Subscriber (and even the DataReader or DomainParticipant for that matter) to also return PRECONDITION_NOT_MET in this situation?


Proposed Resolution:
Return PRECONDITION_NOT_MET when delete_contained_entities() is called on either the DataReader, Subscriber, or DomainParticipant when a DataReader has outstanding loans.


Proposed Revised Text:


Section 2.1.2.2.1.18 delete_contained_entities
Before the paragraph that starts with "Once delete_contained_entities returns successfully," add the paragraph
The operation will return PRECONDITION_NOT_MET if the any of the contained entities is in a state where it cannot be deleted. 


Section 2.1.2.4.1.14 delete_contained_entities
Before the paragraph that starts with "Once delete_contained_entities returns successfully," add the paragraph
The operation will return PRECONDITION_NOT_MET if the any of the contained entities is not in a state where it can be deleted.


Section 2.1.2.5.2.14 delete_contained_entities
Before the paragraph that starts with "Once delete_contained_entities returns successfully," add the paragraph
The operation will return PRECONDITION_NOT_MET if the any of the contained entities is not in a state where it can be deleted. This will occur, for example, if a contained DataReader cannot be deleted because the application has called a read or take operation and has not called the corresponding return_loan operation to return the loaned samples.


Section 2.1.2.5.3.30 delete_contained_entities
Before the paragraph that starts with "Once delete_contained_entities returns successfully," add the paragraph
The operation will return PRECONDITION_NOT_MET if the any of the contained entities is not in a state where it can be deleted.

Return PRECONDITION_NOT_MET when delete_contained_entities() is called on either the DataReader, Subscriber, or DomainParticipant when a DataReader has outstanding loans.

In get_matched_subscription_data, we return PRECONDITION_NOT_MET in this situation.  However, in get_matched_publication_data, we return BAD_PARAMETER.  Previously, they were both returning PRECONDITION_NOT_MET.
In addition, in both sections we state "The operation get_matched_XXXs to find the XXXs that are currently matched" should probably read "can be used to find".


Proposed Resolution:
Make it consistent by returning BAD_PARAMETER in both.


Proposed Revised Text:


Section 2.1.4.2.23 get_matched_subscription_data
In the first sentence of the second paragraph, replace
Replace "the operation will fail and return PRECONDITION_NOT_MET."
With "the operation will fail and return BAD_PARAMETER."

The Requested/OfferedIncompatibleQosStatus contains the last_policy_id and we need to set this to something in case no QoS policy has ever been incompatible.


Proposed Resolution:
Add "const QosPolicyId_t INVALID_QOS_POLICY_ID = 0;" to the PSM.


Proposed Revised Text:
Section 2.2.3 DCPS PSM : IDL
In the Qos section add the following to the list of QosPolicyId_t:
const QosPolicyId_t INVALID_QOS_POLICY_ID = 0;

In Section 2.1.2.4.2.11 the write() operation will return PRECONDITION_NOT_MET if the handle is "valid but does not correspond to the given instance".  Further, it goes on to state that "in the case the handle is invalid, the behavior is in general unspecified, but if detectable by a DDS implementation, the returned error-code will be 'BAD_PARAMETER'."  We should clarify what is "valid" versus "invalid".
Valid means the handle corresponds to a registered instance.


Proposed Resolution:
Clarify that valid means the handle corresponds to a registered instance.
When the handle is valid and does not correspond to the given instance should be up to the implementation to be able to detect this or not.


Proposed Revised Text:


Section 2.1.2.4.2.11 write
Remove the last paragraph that reads "In case the provided handle is valid"


Add a new paragraph directly following the one that reads "If handle is any value other than HANDLE_NIL" as follows:
In case the provided handle is valid, i.e. corresponds to an existing instance, but does not correspond to same instance referred by the 'data' parameter, the behavior is in general unspecified, but if detectable by the Service implementation, the return error-code will be 'PRECONDITION_NOT_MET'.  In case the handle is invalid, the behavior is in general unspecified, but if detectable the returned error-code will be 'BAD_PARAMETER'.


Section 2.1.2.4.2.13 dispose
Replace the next to last paragraph that reads "In case the provided handle is valid."
With the same paragraph above:
In case the provided handle is valid, i.e corresponds to an existing instance, but does not correspond to same instance referred by the 'data' parameter, the behavior is in general unspecified, but if detectable by the Service implementation, the return error-code will be 'PRECONDITION_NOT_MET'.  In case the handle is invalid, the behavior is in general unspecified, but if detectable the returned error-code will be 'BAD_PARAMETER'.

Clarify that valid means the handle corresponds to a registered instance.
When the handle is valid and does not correspond to the given instance should be up to the implementation to be able to detect this or not.

In Section 2.1.2.4.2.14 (dispose_w_timestamp) it states that the operation will return PRECONDITION_NOT_MET if called on an instance that has not yet been registered.  This is not true as the operation will implicitly register the instance just as write does.  This restriction was also originally in 2.1.2.4.2.13 (dispose) but has already been removed.


Proposed Resolution:
Remove the offending paragraph.


Proposed Revised Text:
Section 2.1.2.4.2.14 dispose_w_timestamp
Remove the last two paragraphs , that is the text starting from "The operation must be only called on registered instances." till the end of the section.

Remove the offending paragraph.
In addition, specify the behavior with regards to passing an invalid instance_handle to the operations:  dispose_w_timestamp, write_w_timestamp, unregister_instance call; is behavior is the same that was specified for write, or dispose. Also align the explanation given for passing an 'invalid' handle to the operation "unregister" with the explanation in the other sections

In Section 2.1.2.4.2.13 (dispose) it states "in case the DURABILITY QoS policy is TRANSIENT or PERSISTENT, the Service should take care to clean anything related to that instance so that late-joining applications would not see it".
Is this really necessary?  Is it not acceptable to allow late-joining readers to see an instance with the NOT_ALIVE_DISPOSED instance state?
Does this also apply to TRANSIENT_LOCAL?


We think disposed instances should be propagated to new-ly discovered applications, otherwise there would be no way to enforce ownership of a disposed instance.
Furthermore the application should be notified of disposed instances even if this is the first time the middleware sees the instance because in practice there is no way for the middleware to tell if the application has seen the instance already; for example, following a network partition the middleware may have notified of NOT_ALIVE_NO_WRITERS and following the application taking all the samples it could have reclaimed the information on that instance, so when it sees it again it thinks it is the first time; the application meanwhile could still have information on that instance…
So the user case where a newly joining reader wants to not receive instances that have been disposed before it joined should be handled on the writer side by either explicitly unregistering the instances, or having some new QoS that auto-unregisters disposed instances.


Another issue is whether the act of disposing on the writer side should automatically remove previous samples for that instance, and whether that is done for particular values of the HISTORY (e.g. when it is KEEP_LAST only, or KEEP_LAST with depth==1, or, even for KEEP_ALL). Seems like the control of this should be another QoS on the WRITER_LIFECYCLE.


Proposed Resolution:
For now eliminate the following text from Section 2.1.2.4.2.13 (dispose)
"In case the DURABILITY QoS policy is TRANSIENT or PERSISTENT, the Service should take care to clean anything related to that instance so that late-joining applications would not see it".


Proposed Revised Text:
Section 2.1.2.4.2.13 dispose
Remove the paragraph:
In addition, in case the DURABILITY QoS policy is TRANSIENT or PERSISTENT, the Service should take care to clean anything related to that instance so that late-joining applications would not see it. 

Eliminate the following text from Section 2.1.2.4.2.13 (dispose)
"In case the DURABILITY QoS policy is TRANSIENT or PERSISTENT, the Service should take care to clean anything related to that instance so that late-joining applications would not see it".

In Section 2.1.2.5.2.17 there is a typo in the last paragraph where "datawriter_qos" should be "datareader_qos".


Proposed Resolution:
Correct the typo.


Proposed Revised Text:
Section 2.1.2.5.2.17 copy_from_topic_qos
Replace "datawriter_qos" with "datareader_qos" in the first sentence of the last paragraph that currently reads "This operation does not check the resulting datawriter_qos for consistency".

In the PSM for get_discovered_topic_data() and get_discovered_participant_data() on the DomainParticipant, the data parameter should be first followed by the handle.  The order is correct in the PIM.


Proposed Resolution:
Make the suggested modifications.


Proposed Revised Text:


Section 2.2.3 DCPS PSM : IDL
In the DomainParticipant interface:


Change the order of the parameters to get_discovered_participant_data from "in InstanceHandle_t participant_handle, inout ParticipantBuiltinTopicData participant_data" to inout ParticipantBuiltinTopicData participant_data, in InstanceHandle_t participant_handle".


Change the order of the parameters to get_discovered_topic_data from "in InstanceHandle_t topic_handle, inout TopicBuiltinTopicData topic_data" to inout TopicBuiltinTopicData topic_data, in InstanceHandle_t topic_handle".

In Section 2.1.2.2.1.28 there is a typo in the next to last paragraph where "get_matched_participants" should be "get_discovered_participants".


Proposed Resolution:
Correct the typo.


Proposed Revised Text:
Section 2.1.2.2.1.28 get_discovered_participant_data
In the next to last paragraph replace "get_matched_participants" with "get_discovered_participants" where it currently reads "Use the operation get_matched_participants to find ".

Currently TIMEOUT is not a specified valid return code for the wait() operation.  The specification explicitly states that timeout is conveyed by returning OK with an empty list of conditions.  We should consider adding TIMEOUT as an explicit valid return value.


Proposed Resolution:
Add TIMEOUT as a valid return code to wait().


Proposed Revised Text:
Section 2.1.2.1.6.3 wait


In the next to last paragraph, replace
  "If the duration is exceeded, wait will also return with the return code OK.  In this case, the resulting list of conditions will be empty."
With
  "If the duration is exceeded, wait will return with return code TIMEOUT."

In Section 2.1.4.4.2 (Trigger State of the ReadCondition) the last paragraph describes an example.  However, it is not quite true because reading samples belonging to the latest generation will cause the view_state to become NOT_NEW.
For the sake of the example considered, it may not be necessary to specify the view_state since it is not absolutely relevant to the desired condition being triggered when a new sample arrives given that all other samples were previously at least read.


Proposed Resolution:
Remove mention of the view_state.


Proposed Revised Text:
Section 2.1.4.4.2 Trigger State of the ReadCondition
In the last paragraph, change the sentence from
  "A ReadCondition that has a sample_state_mask = {NOT_READ}, view_state_mask = {NEW} will have trigger_value of TRUE whenever a new sample arrives and will transition to FALSE as soon as all the NEW samples are either read  or taken."


To
  "A ReadCondition that has a sample_state_mask = {NOT_READ} will have trigger_value of TRUE whenever a new sample arrives and will transition to FALSE as soon as all the new samples are either read or taken. "


Section 2.1.4.4.2 Trigger State of the ReadCondition
In that last paragraph change the last sentence from
  "that would only change the SampleState to READ but the sample would still have (SampleState, ViewState) = (READ, NEW) which overlaps the mask on the ReadCondition".
To
  "that would only change the SampleState to READ which still overlaps the mask on the ReadCondition".

The following literals are defined:
DURATION_INFINITY_SEC
DURATION_INFINITY_NSEC
TIMESTAMP_INVALID_SEC
TIMESTAMP_INVALID_NSEC


These are incorrectly named and should be:
DURATION_INFINITE_SEC
DURATION_INFINITE_NSEC
TIME_INVALID_SEC
TIME_INVALID_NSEC


Proposed Resolution:
Add the correct names.


Proposed Revised Text:


Section 2.2.3 DCPS PSM : IDL


Replace:
  const long DURATION_INFINITY_SEC = 0x7fffffff;
  const unsigned long DURATION_INFINITY_NSEC = 0x7fffffff;
  const long TIMESTAMP_INVALID_SEC = -1;
  const unsigned long TIMESTAMP_INVALID_NSEC = 0xffffffff;


With:
  const long DURATION_INFINITE_SEC = 0x7fffffff;
  const unsigned long DURATION_INFINITE_NSEC = 0x7fffffff;
  const long TIME_INVALID_SEC = -1;
  const unsigned long TIME_INVALID_NSEC = 0xffffffff;

In Figure 2-19 in Section 2.1.4.4 (Conditions and Wait-sets):
There is no such delete_statuscondition() operation on the Entity.
The ReadCondition should have a view_state_mask and an instance_state_mask instead of a lifecycle_state_mask.


Proposed Resolution:
Make the suggested corrections.


Proposed Revised Text:
Section 2.1.4.4 Conditions and Wait-sets
In Figure 2-19
Remove "delete_statuscondition()" from the operations listed on the Entity.
Remove "lifecycle_state_mask [*] : ViewStateKind" from the attributes listed on the ReadCondition.
Add "view_state_mask [*] : ViewStateKind" and "instance_state_mask [*] : InstanceStateKind" to the end of the attributes listed on the ReadCondition.

The purpose of the DLRL has been described as being able “to provide more direct access to the exchanged data, seamlessly integrated with the native-language constructs”. This means that DLRL should offer applications an OO-view on the information model(s) they use. In this view, objects behave in the same way as ordinary, native language objects. 
Providing intuitive object access and object navigation should be key-benefits of DLRL compared to plain DCPS usage, where instances and their relations need to be resolved manually. Object navigation in DLRL therefore needs to be simple and intuitive, just like navigating between objects in any ordinary native OO-language.
It is in this aspect that DLRL falls short: object navigation is not simple and intuitive, since it requires intermediate objects (RefRelations and ObjectReferences) that abstract applications from the navigable objects. The purpose of these intermediate objects was to serve as some sort of smart pointers, that abstract applications from knowledge about the exact location and even about the existence of objects (to allow a form of lazy instantiation).
However, since the potential benefits from smart pointer management are rather dependent on the underlying target language, the DLRL specification does not address them and only explains the effort that an application should do in the absence of any smart pointer support. This results in the following problems:
The way in which a DLRL implementation solves pointer arithmetic is not standardized and may change from vendor to vendor and from language to language.
When smart pointer arithmetic is not available, applications will be expected to do lots of extra relational management, which is not in the scope of most application programmers.



Proposed Resolution:



Simplify relation management by removing all intermediate relation objects from the API (Reference, Relation, RefRelation, ObjectReference, ListRelation and MapRelation). Navigation of single relations is done by going directly from ObjectRoot to ObjectRoot (simplifying the IDL object model as well). Implementations can still choose to do smart resource management (e.g. lazy instantiation), but they should do so in a fully transparent way, one that is invisible to applications.
This approach also makes the PIM and PSM (which deviated quite a lot from eachother with respect to these intermediate relation-like objects) more consistent.




Proposed Revised Text:



Section 3.1.5.2, 2nd paragraph, 1st sentence: “DLRL classes are linked to other DLRL classes by means of Relation Objects”. This should be replaced with “… by means of relations.”.


Change the Object Diagram of Figure 3.4. (an alternative Object Diagram will be provided).


Change the table immediately following Figure 3.4 by removing the ObjectReference, Reference, Relation, RefRelation, ListRelation, StrMapRelation and IntMapRelation entries from it.


Remove the foot-note directly following this table (starting with with number 1) that says: “The specification does … (lazy instantiation).” 


Section 3.1.6.3.2: Remove the sequence of ObjectReference attribute from the CacheAccess table and from the explanation below it. As a replacement, see T_DLRL#2 and T_DLRL#3.


Section 3.1.6.3.2: Remove the deref method from the CacheAccess table and from the explanation below it.


Section 3.1.6.3.3: Remove the sequence of ObjectReference attribute from the Cache table and from the explanation below it. As a replacement, see T_DLRL#2 and T_DLRL#3. 


Section 3.1.6.3.3: Remove the deref method from the Cache table and from the explanation below it. 


Section 3.2.1.2.1: Remove the following lines from the CacheAccess and Cache interface: 
readonly attribute ObjectReferenceSeq refs;
ObjectRoot deref( in ObjectReference ref) raises (NotFound);


Section 3.1.6.3.5: Remove the sequence of ObjectReference attribute from the ObjectHome table, and from the explanation below it.


Section 3.2.1.2.1: Remove the following line from the ObjectHome interface:
readonly attribute ObjectReferenceSeq refs;


Section 3.1.6.3.5: Change the entire explanation of the auto_deref attribute from:
“a boolean that indicates if ObjectReference corresponding to that type should be implicitly instantiated (TRUE) or if this action should be explicitly done by the application when needed by calling a deref operation (auto_deref). As selections act on instantiated objects (see section 3.1.6.3.7 for details on selections), TRUE is a sensible setting when selections are attached to that home.”
to:
“a boolean that indicates whether the state of a DLRL Object should always be loaded into that Object (auto_deref = TRUE) or whether this state will only be loaded after it has been accessed explicitly by the application (auto_deref = FALSE).”


Section 3.1.6.3.5: Change the entire explanation of the deref_all method from:
“ask for the instantiation of all the ObjectReference that are attached to that home, in the Cache (deref_all).”
To:
“ask to load the most recent state of a DLRL Object into that Object for all objects managed by that home (deref_all).”


Section 3.1.6.3.5: Change the entire explanation of the underef_all method from:
“ask for the removal of non-used ObjectRoot that are attached to this home (underef_all).”
To:
“ask to unload all object states from objects that are attached to this home (underef_all).”


Section 3.1.6.3.6: Replace all occurrences of ObjectReference with ObjectRoot in the ObjectListener table. Also remove the second parameter of the on_object_modified method.


Section 3.1.6.3.6: Change the explanation of on_object_created from:
“… this operation is called with the ObjectReference of the newly created object (ref).”
to:
“… this operation is called with the value of the newly created object (the_object).”


Section 3.1.6.3.6: Change the explanation of on_object_modified from:
“This operation is called with the ObjectReference of the modified object (ref) and its old value (old_value); the old value may be NULL.”
To:
“This operation is called with the new value of the modified object (the_object).”


Section 3.1.6.3.6: Change the explanation of on_object_deleted from:
“… this operation is called with the ObjectReference of the newly deleted object (ref).”
To:
“… this operation is called with the value of the newly deleted object (the_object).


Section 3.1.6.3.10: Replace all occurrences of ObjectReference with ObjectRoot in the SelectionListener table.


Section 3.2.1.2.1: Change in the IDL interfaces for ObjectListener en SelectionListener the following lines from:
local interface ObjectListener {


    boolean on_object_created ( in ObjectReference ref );
    /**** 
    *  will be generated with the proper Foo type
    * in the derived FooListener
    * boolean on_object_modified ( in ObjectReference ref,
    *                              in ObjectRoot old_value);
    ****/
    boolean on_object_deleted ( in ObjectReference ref );
};


local interface SelectionListener {
    /***
    * will be generated with the proper Foo type
    * in the derived FooSelectionListener
    *
    void on_object_in ( in ObjectRoot the_object );
    void on_object_modified ( in ObjectRoot the_object );
    *
    ***/
    void on_object_out ( in ObjectReference the_ref );
};


To:


local interface ObjectListener {
    /**** 
    *  will be generated with the proper Foo type
    * in the derived FooListener


    boolean on_object_created ( in ObjectRoot the_object );
    boolean on_object_modified ( in ObjectRoot the_object );
    boolean on_object_deleted ( in ObjectRoot the_object );
    *
    ****/
};


local interface SelectionListener {
    /***
    * will be generated with the proper Foo type
    * in the derived FooSelectionListener
    *
    void on_object_in ( in ObjectRoot the_object );
    void on_object_modified ( in ObjectRoot the_object );
    void on_object_out (in ObjectRoot the_object );
    *
    ***/
};


Section 3.2.1.2.2: Change in the IDL interfaces for ObjectListener en SelectionListener the following lines from:


local interface FooListener: DDS::ObjectListener {
    void on_object_modified ( in DDS ::ObjectReference ref,
                                                 in Foo old_value );
};


local interface FooSelectionListener : DDS::SelectionListener {
    void on_object_in ( in Foo the_object );
    void on_object_modified ( in Foo the_object );
};


To:


local interface FooListener: DDS::ObjectListener {
    boolean on_object_created ( in Foo the_object );
    boolean on_object_modified ( in Foo the_object );
    boolean on_object_deleted ( in Foo the_object );
};


local interface FooSelectionListener : DDS::SelectionListener {
    void on_object_in ( in Foo the_object );
    void on_object_modified ( in Foo the_object );
    void on_object_out (in Foo the_object );
};


Section 3.1.6.3.13: Remove the ObjectReference attribute from the ObjectRoot table, and from the explanation below it. 


Section 3.2.1.2.1: Remove the following line from the IDL in the ObjectRoot:
readonly attribute ObjectReference ref;


Section 3.1.6.3.13: Change the following sentence from:
“In addition, application classes (i.e., inheriting from ObjectRoot), will be generated with a set of methods dedicated to each shared attribute:”
To:
“In addition, application classes (i.e., inheriting from ObjectRoot), will be generated with a set of methods dedicated to each shared attribute (including single- and multi-relation attributes):”


Section 3.1.6.3.14 can be removed (ObjectReference). 


Section 3.2.1.2.1: Remove the following lines from the IDL:


/*****************
* ObjectReference
*****************/
struct ObjectReference {
    DLRLOid oid;
    unsigned long home_index;
};
typedef sequence<ObjectReference> ObjectReferenceSeq;


Section 3.1.6.3.15 can be removed (Reference). 


Section 3.1.6.3.20 can be removed (Relation).  


Section 3.1.6.3.21 can be removed (RefRelation). 


Section 3.1.6.3.22 -  Section 3.1.6.3.24 can be removed (ListRelation, IntMapRelation and StrMapRelation).


Section 3.2.1.2.1: Remove the following lines from the IDL:


/********************************
* Value Bases for Relations
*********************************/


valuetype RefRelation {
    private ObjectReference m_ref;
    boolean is_composition();
    void reset();
    boolean is_modified ( in ReferenceScope scope );
};


valuetype ListRelation : ListBase {
    private ObjectReferenceSeq m_refs;
    boolean is_composition();
};


valuetype StrMapRelation : StrMapBase {
    struct Item {
        string key;
        ObjectReference ref;
    };
    typedef sequence <Item> ItemSeq;
    private ItemSeq m_refs;
    boolean is_composition();
};


valuetype IntMapRelation : IntMapBase {
    struct Item {
    long key;
        ObjectReference ref;
    };
    typedef sequence <Item> ItemSeq;
    private ItemSeq m_refs;
    boolean is_composition();
};


Section 3.2.1.1: 1st paragraph after the numbered list of DLRL entities, remove the following sentence: “(with the exception of ObjectReference, …. , so that it can be embedded). Section 3.2.1.2.2: Change the following lines in IDL from:


valuetype FooStrMap : DDS::StrMapRelation { // StrMap<Foo>
…
valuetype FooIntMap : DDS::IntMapRelation { // IntMap<Foo>


To:


valuetype FooStrMap : DDS::StrMap { // StrMap<Foo>
…
valuetype FooIntMap : DDS::IntMap { // IntMap<Foo>


Section 3.2.2.3.1: Remove the “Ref” value from the allowed list of patterns, so change the templateDef . The templatedef then changes  from:
<!ATTLIST templateDef name CDATA #REQUIRED
                    pattern (List | StrMap | IntMap | Ref) #REQUIRED
                    itemType CDATA #REQUIRED>


To (see also Issues T_DLRL#7 and T_DLRL#8):


<!ATTLIST templateDef name CDATA #REQUIRED
                    pattern (Set | StrMap | IntMap) #REQUIRED
                    itemType CDATA #REQUIRED>


Section 3.2.2.3.2.3, 2nd bullet: Remove the “Ref” pattern from the list of supported constructs. 


Section 3.2.3.2: Replace the forward valuetype declaration for RadarRef with a forward declaration of type Radar, so change from:
valuetype RadarRef    // Ref<Radar>
To:
valuetype Radar;


Section 3.2.3.3: Remove the following line from the XML (in both XML examples): 
“<templateDef name=“RadarRef” 
                          pattern=“Ref” itemType=“Radar”/>”

Simplify relation management by removing all intermediate relation objects from the API (Reference, Relation, RefRelation, ObjectReference, ListRelation and MapRelation). Navigation of single relations is done by going directly from ObjectRoot to ObjectRoot (simplifying the IDL object model as well). Implementations can still choose to do smart resource management (e.g. lazy instantiation), but they should do so in a fully transparent way, one that is invisible to applications.
This approach also makes the PIM and PSM (which deviated quite a lot from each other with respect to these intermediate relation-like objects) more consistent.

Both the CacheAccess and Cache have some functional overlap. It would be nice if this overlap would be migrated to a common generalization (for a good reason, see also Issue T_DLRL#3).




Proposed Resolution:



Introduce a new class called CacheBase, that has represents the common functionality. Both the Cache and the CacheAccess inherit from this common base-class.

Introduce a new class called CacheBase, that has represents the common functionality. Both the Cache and the CacheAccess inherit from this common base-class.

The DLRL offers two different update modes for its Primary Cache: an automatic mode in which object creations, updates and deletions are pushed into the Cache and a manual mode in which the Cache content are refreshed on user-demand.
>From the perspective of a Cache-user, it is important to find out what has happened to the contents of the Cache during the latest update session. In automatic update mode, Listeners are triggered for each Object creation, modification or deletion in the primary Cache. However, when the Cache is in manual update mode none of these Listeners are triggered and no means exist to examine what has happened during the last update round. The same can be said for the CacheAccess, that does not have an automatic update mode and neither has any means to examine the changes that were applied during the last invocation of the “refresh” method.



Proposed Resolution:



We therefore propose to add some extra methods to the ObjectHome, that allow an application to obtain the list of Objects that have been created, modified or deleted in the latest update round of a specific CacheBase

We therefore propose to add some extra methods to the ObjectHome, that allow an application to obtain the list of Objects that have been created, modified or deleted in the latest update round of a specific CacheBase.

The ObjectExtent is a manager for a set objects. Basically it is a wrapper that offers functions to modify its contents and to create a sub-set based on on a user-defined function. The problem with using an Extent is that it overlaps with the get_objects method introduced in issue T_DLRL#3, and that it is not clear whether a new Extent should be allocated each time the user obtains it from the ObjectHome, or whether the existing Extent should be re-used and therefore its contents be overwritten with every update.  
Furthermore, every application can easily write its own code that modifies every element in this sequence (no specialized ObjectModifier is required for that, a simple for-loop can do the trick), and similarly an application can also write code to filter each element and to store matching results in another sequence. Filtering and modifying objects like this are really business logic, and do not have to be part of a Middleware specification. 



Proposed Resolution:



Remove the ObjectModifier and ObjectExtent from the specification. This saves two implied interfaces that are not required for most types of applications, but which can still be solved very well at application level. Replace the extent on the ObjectHome with a sequence of ObjectRoots.

Remove the ObjectModifier and ObjectExtent from the specification. This saves two implied interfaces that are not required for most types of applications, but which can still be solved very well at application level. Replace the extent on the ObjectHome with a sequence of ObjectRoots.

Summary:



The specification states that it is possible to clone an Object from the primary Cache into a CacheAccess, together with its related or contained objects for a specified navigatable depth.  (We will refer to such an Object tree as a cloning contract from now on).  However, while the cloning of objects is done on contract level, the deletion of clones is done on individual object level. What should happen to related objects when the top level object is deleted? Furthermore, it is unclear what the result should be when a relationship from an object A to an object B changes from object A to object C. Should the next refresh of the CacheAccess only refresh the states of objects A and B, or should object C be added and object B be removed from the CacheAccess? 



Proposed Resolution:



Formally introduce the concept of a cloning contract into the API to replace all other clone-related methods. Cloning contracts are defined on the CacheAccess and are evaluated when the CacheAccess is refreshed. 

Formally introduce the concept of a cloning contract into the API to replace all other clone-related methods. Cloning contracts are defined on the CacheAccess and are evaluated when the CacheAccess is refreshed.

Object State Transitions of Figure 3-5 and 3-6 should be corrected and simplified


Summary:



The state transition diagrams in Figure 3-5 and 3-6 are difficult to understand, and the 2nd diagram of Figure 3-5 is missing. (Instead of this 2nd diagram, the first diagram of Figure 3-6 has wrongly been duplicated here).
Furthermore, since it is difficult to distinguish between primary and secondary Objects and their primary and secondary states, it would be nice if more intuitive names and states could be used instead.
Finally, some of the possible conditions in which a state transition can occur are not mentioned in these state transition diagrams, which would even require for them to become more complex.



Proposed Resolution:



Introduce new names for the different states, and try to re-use the same set of states for each diagram. We propose not to speak about primary and secondary objects, but to speak about Cache Objects (located in a Cache) and CacheAccess objects (located in a CachAccess). Furthermore, we propose not to speak about primary and secondary states, but to speak about a READ state (with respect to incoming modifications) and a WRITE state (with respect to local modifications).
Decouple Objects in the Cache from Objects in a CacheAccess, it makes the the the idea of what a Cache or CacheAccess represent more understandable. The Cache represents the global Object states as accepted by the System, a READ_ONLY CacheAccess represents a temporary state of a Cache, and a READ_WRITE or WRITE_ONLY CacheAccess represents the state of what  the user intends the system to do in the future.
Since a Cache then only represents the global state of the system (and not what the user intends to do), it does not have a WRITE state (it will be VOID). A READ_ONLY CacheAccess also has no WRITE state (VOID), but a WRITE_ONLY CacheAccess has no READ state (VOID). A READ_WRITE CacheAccess has both a WRITE and a READ state, and the WRITE state represents what the user has modified but not yet committed, and the READ state represent what the system has modified during its last update.

Introduce new names for the different states, and try to re-use the same set of states for each diagram. We propose not to speak about primary and secondary objects, but to speak about Cache Objects (located in a Cache) and CacheAccess objects (located in a CacheAccess). Furthermore, we propose not to speak about primary and secondary states, but to speak about a READ state (with respect to incoming modifications) and a WRITE state (with respect to local modifications).

Decouple Objects in the Cache from Objects in a CacheAccess, it makes the idea of what a Cache or CacheAccess represent more understandable. The Cache represents the global Object states as accepted by the System, a READ_ONLY CacheAccess represents a temporary state of a Cache, and a READ_WRITE or WRITE_ONLY CacheAccess represents the state of what  the user intends the system to do in the future.

Since a Cache then only represents the global state of the system (and not what the user intends to do), it does not have a WRITE state (it will be VOID). A READ_ONLY CacheAccess also has no WRITE state (VOID), but a WRITE_ONLY CacheAccess has no READ state (VOID). A READ_WRITE CacheAccess has both a WRITE and a READ state, and the WRITE state represents what the user has modified but not yet committed, and the READ state represent what the system has modified during its last update.

To really decouple Cache Objects from CacheAccess objects,  it is even possible to allow an object to be cloned in multiple CacheAccesses. But this issue is up for discussion. Probably every writeable CacheAccess should then have its own DCPS Publisher, so that an object cloned in multiple Writable CacheAccesses will be seen in the DCPS as being owned by two different DataWriters. The Ownership QoS will then decide how to handle this situation.

Summary:


It would be nice to have an iterator for Collection types to be able to iterate through the entire Collection. For Maps there should be iterators for both the keys and the values.



Proposed Resolution:



Add an abstract Iterator class to the DLRL, which has typed implementations to access the underlying data. 

Summary:



The Collection definitions are very different between the PIM and the PSM. 



Proposed Resolution:



Use corresponding Collection definitions in PIM and PSM. Make a strict separation in the IDL between typed operations (to be implemented in the typed specializations, but to be mentioned in the untyped parents) and untyped operations (to be implemented in the untyped parents). Also remove methods that have a functional overlap with other methods.

Use corresponding Collection definitions in PIM and PSM. Make a strict separation in the IDL between typed operations (to be implemented in the typed specializations, but to be mentioned in the untyped parents) and untyped operations (to be implemented in the untyped parents). Also remove methods that have a functional overlap with other methods. Object Diagram of Figure 3.4. (We have an alternative Object Diagram).

Summary:



In many applications there is a need for an unordered Collection without keys. 



Proposed Resolution:



Add the Set as a supported Collection type in DLRL.

Add the Set as a supported Collection type in DLRL

Summary:



In the current specification, the ObjectQuery inherits from the ObjectFilter, making it an ObjectFilter as well. That means that performing Queries can no longer be delegated to the DCPS, since the Selection invokes the check_object method on the ObjectFilter for that purpose.



Proposed Resolution:



Make the ObjectFilter and the ObjectQuery to separate classes with a common parent called SelectionCriterion. A SelectionCriterion can be then be attached to a Selection, which will either invoke the check_object method in case of a Filter, or delegate the Query to DCPS in case of a Query.

Make the ObjectFilter and the ObjectQuery to separate classes with a common parent called SelectionCriterion. A SelectionCriterion can be then be attached to a Selection, which will either invoke the check_object method in case of a Filter, or delegate the Query to DCPS in case of a Query

From the current DLRL specification it is not clear how to obtain your initial CacheFactory.



Proposed Resolution:



Add a static get_instance method to make the CacheFactory a singleton, just like we did for the DomainParticipantFactory in the DCPS.

Add a static get_instance method to make the CacheFactory a singleton, just like we did for the DomainParticipantFactory in the DCPS

Summary:



According to the current specification, it is possible to interrupt an update round, by invoking the disable_update mehod in the middle of such an update round. This makes no sense, since it can leave the Cache in an undefined and possibly inconsistent state. The specification does also not explain how to recover from such a state.



Proposed Resolution:



Make sure that the automatic update mode can never be changed while in the middle of an update round. This way, update rounds can never be interrupted and the Cache will always be in a consistent state. This also removes the need for the interrupted and update_round parameters in the callback methods of the CacheListener. 
Also remove the related_cache parameter from the CacheListener, since it is not needed and is also missing in the IDL.

Make sure that the automatic update mode can never be changed while in the middle of an update round. This way, update rounds can never be interrupted and the Cache will always be in a consistent state. This also removes the need for the interrupted and update_round parameters in the callback methods of the CacheListener. 
Also remove the related_cache parameter from the CacheListener, since it is not needed and is also missing in the IDL

Summary:


It is not clear why we should need a lock/unlock on the Cache when we can turn on and off the automatic updates. If an application does not want to be interrupted by incoming updates, it can simply disable the automatic updates, re-enabling them afterwards.



Proposed Resolution:



Remove the lock and unlock methods of the Cache. 

Summary:



The CacheListener currently supports only two call-backs to signify the start and end of an update round. However because listeners are only used in enabled update mode it is important that when the DLRL switches between the enabled and disabled update mode that the listeners are notified, as the switch between update modes does not necessarily originate from the thread that registered the listener as well, and the fact that updates are enabled or disabled is a major event that should be known by the listeners.



Proposed Resolution:



Add two methods to the CacheListener interface, one for signalling a switch to automatic update mode, and for for signalling a switch to manual update mode.

Add two methods to the CacheListener interface, one for signalling a switch to automatic update mode, and for for signalling a switch to manual update mode.

Summary:



The OID currently consists of two numbers: a creator_id and a local_id. The philosophy is that each writer should obtain its own unique creator_id, and can then sequence number each object created with it to obtain unique object identifiers. The specification does not specify how the writers should obtain their unique creator_id. Building a mechanism to distribute unique OIDs requires knowledge about the underlying system characteristics, and this information is only available in DCPS.



Proposed Resolution:



Make the definition of the OID vendor specific. This allows a vendor to specify its own algorithms to guarantee that each object has got a unique identifier.
The only location where the application programmer actually has to know the contents of the OID is in the create_object_with_oid method on the ObjectHome. However, we see no use-case for this method and propose to remove it.

Make the definition of the OID vendor specific. This allows a vendor to specify its own algorithms to guarantee that each object has got a unique identifier.
The only location where the application programmer actually has to know the contents of the OID is in the create_object_with_oid method on the ObjectHome. However, we see no use-case for this method and propose to remove it.

XML mapping file does not allow you to define both the Topic name and the Topic type_name separately


Summary:



In the DCPS, there is a clear distinction between a topic name and a topic type. (Both names must be provided when creating a Topic). However, the DLRL mapping XML only allows us to specify one name attribute which is called ‘name’. It is unclear whether this name should identify the type name or the topic name. Currently we just have to assume that the topic name and type name are always chosen to be equal, but that does not have to be the in a legacy topic model.



Proposed Resolution:



Add a second (optional) attribute to the mainTopic, extensionTopic, placeTopic and multiPlaceTopic that identifies the type name. If left out, the type is assumed to be equal to the topic name.

Add a second (optional) attribute to the mainTopic, extensionTopic, placeTopic and multiPlaceTopic that identifies the type name. If left out, the type is assumed to be equal to the topic name.

Summary:



Currently there are separate methods to find a specific object based on its OID in the Cache and in a CacheAccess. It would be nice to have one method to search for an Object in any CacheBase.



Proposed Resolution:



Add a CacheBase parameter to the find_object method and remove the find_object_in_access method.

Add a CacheBase parameter to the find_object method and remove the find_object_in_access method.

Summary:



The DLRL PSM specifies a number of Exceptions, but these are not explained in the PIM, and they do not cover the entire range of all possible errors.



Proposed Resolution:



Make an extensive list of all possible Exceptions and explain them in the PIM as well.
Add a String message to the exception that can give more details about the context of the exception.

Make an extensive list of all possible Exceptions and explain them in the PIM as well.
Add a String message to the exception that can give more details about the context of the exception

Summary:



The current Metamodel explains the different BasicTypes that are supported in DLRL. Although on DCPS sequences are supported for all primitive types, the DLRL states that the only sequences that can be supported are sequences of octet.



Proposed Resolution:



Explicitly state that the DLRL supports sequences of all supported primitive types.

 Indicate that in case of manual mapping key-fields of registered objects may not be changed


Summary:



When using the DLRL with pre-defined mapping, keyfields of the topic can be mapped to ordinary attributes of a DLRL object. However, chaning these attributes on the DLRL object results in a change of identity on DCPS. 



Proposed Resolution:



Do not allow attributes that are mapped to key fields in the underlying Topic to be modified after the DLRL object has been registered. Throw a PreconditionNotMet Exception if this rule is violated.

Do not allow attributes that are mapped to key fields in the underlying Topic to be modified after the DLRL object has been registered. Throw a PreconditionNotMet Exception if this rule is violated.

Summary:



There is no (default) constructor specified for the ObjectHome class. Nowhere in the specification it is specified how an ObjectHome should be instantiated and what the default values will be for auto_deref and for the filter expression.



Proposed Resolution:



Explicitly state that the default constructor should be used to instantiate an ObjectHome. Also state that by default the value of auto_deref will be set to true, and the filter expression will be set to NULL. Setting auto_deref to true by default ensures that the application developer has to make the conscious decision to set the auto_deref functionality to false for performance gain, which is more natural then the other way around

Explicitly state that the default constructor should be used to instantiate an ObjectHome. Also state that by default the value of auto_deref will be set to true, and the filter expression will be set to NULL. Setting auto_deref to true by default ensures that the application developer has to make the conscious decision to set the auto_deref functionality to false for performance gain, which is more natural then the other way around

Raise a PreconditionNotMet when changing a filter expression on a registered ObjectHome


Summary:



ObjectHome contains a set_filter method to set the filter attribute. This method may only be called before an object home is registered. However the only exception that is thrown is the BadParameter exception. We believe this exception does not cover the fact that the set_filter can be called after the objecthome is registered, as bad parameter is not a good description for the error that should be generated then. 



Proposed Resolution:



Raise a PreconditionNotMet Exception when the set_filter method is invoked after the ObjectHome has been registered to a Cache.

To clearly distinguish between a FilterCriterion (used with Selections) and a content-filter (used at the ObjectHome), we propose to rename the attribute named "filter" to "content_filter".
Furthermore, raise a PreconditionNotMet Exception when the set_content_filter method is invoked after the ObjectHome has been registered to a Cache.

Summary:
In section 2.1.2.2.2, the "get_domain_id" method is mentioned in the table, but is not explained in the following sections.


Proposed Resolution::
Add a section that explains the "get_domain_id" method.


Proposed Revised Text::
Replace section 2.1.2.2.1.26 with the following one:


2.1.2.2.1.26 get_domain_id
This operation retrieves the domain_id used to create the DomainParticipant. The domain_id identifies the Domain to which the DomainParticipant belongs. As described in the introduction to Section 2.1.2.2.1 each Domain represents a separate  data "communication plane"  isolated from other domains.

PIM and PSM are contradicting with respect to the "get_sample_lost_status" operation.


Summary:
According to the PIM in section 2.1.2.5.2(.12), the Subscriber class has got an operation called "get_sample_lost_status". According to the PSM in section 2.2.3, this operation is not part of the Subscriber, but of the DataReader.


Proposed Resolution::
Move the "get_sample_lost_status" operation in the PIM to the DataReader as well.
RTI: We propose ewmoving this from the Subscriber altoguether and moving it to the DataReader.


Proposed Revised Text::


In the Subscriber table in section 2.1.2.5.2 Subscriber Class
Remove the entry on the operation get_sample_lost_status()


In the DataReader table in section section 2.1.2.5.3 DataReader Class
Add the entry on the get_sample_lost_status() operation that was removed from the Subscriber class


Add section 2.1.2.5.3.24, previous 2.1.2.5.3.24 becomes 2.1.2.5.3.25:
2.1.2.5.3.24 get_sample_lost_status
This operation allows access to the SAMPLE_LOST_STATUS communication status. Communication statuses are described in Section 2.1.4.1, "Communication Status," on page 2-125.

Summary:
In section 2.1.2.4.1.17, the explanation for the "copy_from _topic_qos" operation mentions two parameters called "topic_qos" and  "datawriter_qos_list". Both parameter names do not exist.


In the PSM (section 2.2.3) the first two parameters for all "read()" and "take()" methods (and their variants) are consistently called "received_data" and "sample_infos". In the DataReader PIM in section 2.1.2.5.3, these same names are only used for the "read()" and "take()" methods. All their variants and all have a first parameter called "data_values".  The FooDataReader PIM has the same issue, but even uses the name "data_values" for the read() and take() methods themselves.


Proposed Resolution::
Replace "topic_qos" with "a_topic_qos" and "datawriter_qos_list" with "a_datawriter_qos".


Consistently use the parameter name "received_data" in bot the PIM and the PSM.


We propose we either ignore the second change regarding 'data_values' or change it the other way around (from received_data to data_values). This impacts the specification less. There are a lot of places that would be affected by the change to "received_data" from "data_values"


Proposed Revised Text::


Section 2.1.2.4.1.17 copy_from_topic_qos:
1st paragraph, replace: "topic_qos" with "a_topic_qos"
1st, 2nd, and 3rd paragraph, replace:  "datawriter_qos_list" with "a_datawriter_qos"


Section 2.2.3
replace formal paramater name "received_data" with "data_value" or "data_values" depending on whether the typeis a sequence or not This affects DataReader::take* DataReader::read*, FooDataReader::take* and FooDataReader::read*


Section 2.1.2.5.3 DataReader Class table replace "received_data" with "data_values". This affects the operations:
return_loan
take
read



Section 2.2.3 DCPS PSM : IDL
Change formal parameter of read/take operations from "received_data" with "data_values". This affects the operations:

Replace "topic_qos" with "a_topic_qos" and "datawriter_qos_list" with "a_datawriter_qos".
Change it the other way around (from received_data to data_values). This impacts the specification less. There are a lot of places that would be affected by the change to "received_data" from "data_values".

Summary:
In section 2.1.3.19 it is not clear how to specify unlimited resource limits. (It is mentioned in the QoS table in section 2.1.3 that the default setting for resource_limits is length_unlimited, but in the context of 2.1.3.19 this is not repeated).


Proposed Resolution::
Specify in Section 2.1.3.19 that the constant LENGTH_UNLIMITED must be used to specify unlimited resource limits.


Proposed Revised Text::
In section 2.1.3.19 add the following paragraph before the last paragraph in the section (the one that starts with "The setting of RESOURCE_LIMITS …":


The constant LENGTH_UNLIMITED may be used to indicate the absence of a particular limit. For example setting max_samples_per_instance to LENGH_UNLIMITED will cause the middleware to not enforce this particular limit.

Specify in Section 2.1.3.19 that the constant LENGTH_UNLIMITED must be used to specify unlimited resource limits.

Summary:
See also issue R#123 of our previous Issues document. (Addition of an IllegalOperation Errorcode). This issue has been solved on the PIM level, but the ReturnCode has not been added to the IDL PSM.


Proposed Resolution::
Add the RETCODE_ILLEGAL_OPERATION ReturnCode to the PSM in section 2.2.3.


Proposed Revised Text::
Section 2.2.3 DCPS PSM : IDL
after the line "const ReturnCode_t RETCODE_NO_DATA = 11;" add the line:
const ReturnCode_t RETCODE_ILLEGAL_OPERATION = 12;

Add the RETCODE_ILLEGAL_OPERATION ReturnCode to the PSM in section 2.2.3.

Summary:
In section 2.1.4.2.1, it is explained that a statusflag becomes TRUE if a plain communication status changes, and becomes FALSE again each time the application accesses the plain communication status via the proper get_<plain_communication_status> operation. This is not a complete description, since it only assumes an explicit call to read the communication status. It is also possible (by attaching a Listener) to implicitly read the status (it is then passed as a parameter to the registered callback method), and then afterwards the status flag should also be set to FALSE as well.
Furthermore, the Status table in section 2.4.1 mentions that all total_count_change fields are being reset when a Listener callback is performed. The same thing happens when a get_<plain_communication_status> operation is invoked. It would make sense that a Listener callback behaves in a similar way as an when explicitly reading the plain communication status.


Proposed Resolution::
Mention explicitly in section 2.1.4.2.1 that a status flag is also set to FALSE when a listener callback for that status has been performed. (We need to think what consequences this will have for NIL-Listeners, that behave like a no-op. Probably they should also reset the flag in that case.)


Proposed Revised Text::


In section 2.1.4.2.1 after the paragraph:
For the plain communication status, the StatusChangedFlag flag is initially set to FALSE. It becomes TRUE whenever the plain communication status changes and it is reset to FALSE each time the application accesses the plain communication status via the proper get_<plain communication status> operation on the Entity.


Add the paragraphs:


The communication status is also reset to FALSE whenever the associated listener operation is called as the listener implicitly accesses the status which is passed as a parameter to the operation.  The fact that the status is reset prior to calling the listener means that if the application calls the  get_<plain communication status> from inside the listener it will see the status already reset.


An exception to this rule is when the associated listener is the 'nil' listener. As described in section 2.1.4.3.1 the 'nil' listener is treaded as a NOOP and the act of calling the 'nil' listener does not reset the communication status.

Mention explicitly in section 2.1.4.2.1 that a status flag is also set to FALSE when a listener callback for that status has been performed. (We need to think what consequences this will have for NIL-Listeners, that behave like a no-op. Probably they should also reset the flag in that case.)

Summary:
In section 2.1.2.2.1. DomainParticipant Class it says:
The following operations may be called even if the DomainParticipant is enabled. Other operations will have the value NOT_ENABLED if called on a disabled


It should say:
The following operations may be called even if the DomainParticipant is not enabled. Other operations will return the value NOT_ENABLED if called on a disabled


Proposed Resolution:


Proposed Revised Text:
In section 2.1.2.2.1. DomainParticipant Class, paragraph at the end of the section before the bullet points


Replace:
The following operations may be called even if the DomainParticipant is enabled. Other operations will have the value NOT_ENABLED if called on a disabled


With:
The following operations may be called even if the DomainParticipant is not enabled. Other operations will return the value NOT_ENABLED if called on a disabled

Summary:
On page 2-70 at the end of section 2.1.2.5.2 (Subscriber Class) the description states that a list of operations including delete_datareader may return NOT_ENABLED. The operation delete_datareader should be removed from this list.


Proposed Resolution:


Proposed Revised Text:
In section 2.1.2.5.2 Subscriber Class, at the end right before section 2.1.2.5.2.1 replace paragraph:


All operations except for the base-class operations set_qos, get_qos, set_listener, get_listener, enable, get_statuscondition, create_datareader, and delete_datareader may return the value NOT_ENABLED.


With:


All operations except for the base-class operations set_qos, get_qos, set_listener, get_listener, enable, get_statuscondition, and create_datareader may return the value NOT_ENABLED.

Summary:
On 2-94 section 2.1.2.5.5 (SampleInfo Class) the description of publication_handle states that it identifies locally the DataWriter that modified the instance.


Clarify that locally means the instance_handle from the builtin Publication DataReader belonging to the Participant of the DataReader from which the sample is read.


Proposed Resolution:


Proposed Revised Text:


In section 2.1.2.5.5 SampleInfo Class, replace the bullet:
the publication_handle that identifies locally the DataWriter that modified the instance.


With the bullet:
the publication_handle that identifies locally the DataWriter that modified the instance. The publication_handle is the same InstanceHandle_t that is returned by the operation get_matched_publications on the DataReader and can also be used as a parameter to the DataReader operation get_matched_publication_data.


In section 2.1.2.5.3.33 get_matched_publications after the first paragraph add the paragraph.
The handles returned in the 'publication_handles' list are the ones that are used by the DDS implementation to locally identify the corresponding matched DataWriter. These handles match the ones that appear in the 'instance_handle' field of the SampleInfo when reading the "DCPSPublications" builtin topic.


In section 2.1.2.5.3.33 get_matched_publications after the first paragraph add the paragraph:
The handles returned in the 'subscription_handles' list are the ones that are used by the DDS implementation to locally identify the corresponding matched DataReader. These handles match the ones that appear in the 'instance_handle' field of the SampleInfo when reading the "DCPSSubscriptions" builtin topic.

Summary:
In the QoS table for built-in Subscriber and DataReader objects (Section 2.1.5 Built-in Topics) the value for autopurge_disposed_sample_delay is missing.


Proposed Resolution:


Proposed Revised Text:
In the UML figure in section 2.1.3 Supported QoS
Class ReaderDataLifecycleQoS, Add the field:
autopurge_disposed_sample_delay : Duration_t


In section 2.1.5 Built-in Topics, QoS table, READER_DATA_LIFECYCLE row, add:
autopurge_disposed_sample_delay = infinite

Summary:
In section 2.1.2.4.2.5 register_instance the description states that if this operation exceeds the max_blocking_time this operation will return TIMEOUT. However this is not possible because the operation cannot return a ReturnCode_t value.


Proposed Resolution:


Proposed Revised Text:


Section section 2.1.2.4.2.5 register_instance
At the end of the 5th paragraph Replace:
If max_blocking_time elapses before the DataWriter is able to store the modification without exceeding the limits, the operation will fail and return TIMEOUT


With:
If max_blocking_time elapses before the DataWriter is able to store the modification without exceeding the limits, the operation will fail and return HANDLE_NIL

Summary:
On page 2-65 the second last bullet states
The sample_rank indicates the number or samples of the same instance that follow the current one in the collection.
The 'or' should be 'of'.


Proposed Resolution:


Proposed Revised Text:
Section 2.1.2.5.1 Access to the data, second to last bullet
Replace 'or' with 'of' in the sentence:
The sample_rank indicates the number or samples of the same instance that follow the current one in the collection.


Resulting in:
The sample_rank indicates the number of samples of the same instance that follow the current one in the collection.

Summary:
The instance state is only accessible via sampleInfo and this requires the availability of data.
This implies that the dispose and the no writer state of an instance may not be noticed if the application has taken all samples.
Subsequent instance state changes are only notified if all samples are taken.


Consequently, it's very hard to receive notifications on disposal of instances.


Requires data so applications should use read instead of take.
But take is required for subsequent notifications.
Applications are not notified on arrival of data if they choose not to take all data (read or take not all)


Occasionally Application may need to react on disposal or the no writer state of instances e.g. cleanup allocated resources and applications may also continuously take all samples to save resources.


In this case a dispose or no writer state will only be noticed if a new generation appears, which may never happen.
Occasionally applications may want to keep all read samples and still be notified on data arrival.


Applications should be notified whenever new data arrives whether they have taken all previous data samples or not
According to the spec (section 2.1.2.5.3.8) it is possible to get 'meta samples' that is samples that have a SampleInfo but have no associated data, this can be used to notify of disposal, no writers and such.


Proposed Resolution:
Always reset the read communication status flag on any read or take operation.


Provide a notification mechanism on the DataReader that specifies the instance handle of the instance whose state has changed.
-> This is managed by the meta-sample mechanism mentioned above


Provide a method on an instance handle to access the instance state.


Modify figure 2-16 and section 2.1.4.2.2 to state that the ReadCommunicationStatus is reset to FALSE whenever the corresponding listener operation is called, or else if a read or take operation is called on the associated DataReader


In addition the ON_DATA_ON_READERS status is reset if the on_data_available is called. The inverse (resetting the ON_DATA_AVAILABLE status when the on_data_on_readers is called) does not happen.



Proposed Revised Text:


Section 2.1.2.5 Subscription Module, Figure 2-10
Add the following field to the SampleInfo class:
valid_data : boolean


Section 2.1.2.5.1 Access to the data (see attached document access_to_the_data2CMP.pdf for the resulting section with changes)


>>Aftter 2nd paragraph "Each of these" add the section heading:
2.1.2.5.1.1 Interpretation  of the SampleInfo
3rd paragraph; add the following bullet after the bullet that starts with "The instance_state of the related instance"
The valid_data flag.  This flag indicates whether there is data associated with the sample. Some samples do not contain data indicating only a change on the instance_state of the corresponding instance.


>>Before the paragraph that starts with "For each sample received" add the section headings:
2.1.2.5.1.2 Interpretation  of the SampleInfo sample_state


>>Before the paragraph that starts with "For each instance the middleware internally maintains" add the section heading:
2.1.2.5.1.3 Interpretation  of the SampleInfo instance_state


>>Before the paragraph that starts with "For each instance the middleware internally maintains two counts: the disposed_generation_count and no_writers_generation_count" add the following subsections (2.1.2.5.1.4, and 2.1.2.5.1.5):


2.1.2.5.1.4 Interpretation  of the SampleInfo valid_data
Normally each DataSample contains both a SampleInfo and some Data. However there are situations where a DataSample contains only the SampleInfo and does not have any associated data. This occurs when the Service notifies the application of a change of state for an intance that was caused by some internal mechanism (such as a timeout) for which there is no associated data. An example of this situation is when the Service detects that an instance has no writers and changes the coresponding instance_state to  NOT_ALIVE_NO_WRITERS.


The actual set of scenarios under which the middleware returns DataSamples containing no Data is implementation dependent. The application can distinguish wether a particular DataSample has data by examining the value of the valid_data flag. If this flag is set to TRUE, then the DataSample contains valid Data, if the flag is set to FALSE the DataSample contains no Data.
To ensure corerctness and portability, the valid_data flag must be examined by the application prior to accessing the Data associated with the DataSample and if the flag is set to FALSE, the application should not access the Data associated with the DataSample, that is, teh application should access only the SampleInfo.


2.1.2.5.1.5 Interpretation  of the SampleInfo disposed_generation_count and no_writers_generation_count
Before the paragraph that starts with "The sample_rank and generation_rank available in the SampleInfo are computed …" add the section heading:
2.1.2.5.1.6 Interpretation  of the SampleInfo sample_rank, generation_rank, and absolute_generation_rank



>>Before the paragraph that starts with "These counters and ranks allow the application to distinguish" add the section heading:
2.1.2.5.1.7 Interpretation  of the SampleInfo counters and ranks


>>Before the paragraph that starts with "For each instance (identified by the key), the middleware internally…" add the section heading:
2.1.2.5.1.8 Interpretation  of the SampleInfo view_state


>>Before the paragraph that starts with "The application accesses data by means of the operations read or take on the DataReader" add the section heading:
2.1.2.5.1.9 Data access patterns


Section 2.1.2.5.5 Sample Info class


Add another bullet to the list:
The valid_data flag that indicates whether the DataSample contains data or else it is only used to communicate of a change in the instance_state of the instance.


Section 2.2.3 DCPS PSM : IDL


struct SampleInfo
Add the following field at the end of the structure:
  boolean valid_data


The resulting structure is:
struct SampleInfo {
    SampleStateKind sample_state;
    ViewStateKind view_state;
    InstanceStateKind instance_state;
    Time_t source_timestamp;
    InstanceHandle_t instance_handle;
    InstanceHandle_t publication_handle;
    long disposed_generation_count;
    long no_writers_generation_count;
    long sample_rank;
    long generation_rank;
    long absolute_generation_rank;
    boolean valid_data;
};

According to the spec (section 2.1.2.5.3.8) it is possible to get 'meta samples' that is samples that have a SampleInfo but have no associated data, this can be used to notify of disposal, no writers and such. So this part is not a problem.
The above problems can be solved as follows:
·	Always reset the read communication status flag on any read or take operation.
·	State that meta-samples (samples with no data) are used to provide a notification mechanism on the DataReader that specifies the instance handle of the instance whose state has changed.
Specifically the issue can be resolved by:
1.	Modifying figure 2-16 and section 2.1.4.2.2 to state that the ReadCommunicationStatus is reset to FALSE whenever the corresponding listener operation is called, or else if a read or take operation is called on the associated DataReader
2.	Changing the description of the ON_DATA_ON_READERS status such that it is reset if the on_data_available is called. The inverse (resetting the ON_DATA_AVAILABLE status when the on_data_on_readers is called) does not happen.

Summary:
In section 2.1.3.9.2 EXCLUSIVE kind (the last sentence on page 2-114) the specification states that ownership changes are notified via a status change. However there is no status change that notifies of ownership change. The only way to detect it is to look at the SampleInstance and see that the publication_handle has changed.


Proposed Resolution:
Remove the sentence. We could add the Status, Listener, and Callback, but it seems unnecessary until we see some actual use-cases that require this…


Proposed Revised Text:


In section  2.1.3.9.2 EXCLUSIVE kind, last sentence in last paragraph, remove the sentence:
"The DataReader is also notified of this via a status change that is accessible by means of the Listener or Condition mechanisms."

Remove the sentence. We could add the Status, Listener, and Callback, but it seems unnecessary until we see some actual use-cases that require this.

Must read/take_next_instance() require that the handle corresponds to a known data-object?  


Summary:


In sections for read/take_next_instance() and read/take_next_instance_w_condition() it states that if detectable the implementation should return BAD_PARAMETER in this case or otherwise the situation is unspecified.
It might be desirable to allow for an invalid handle to be passed in, especially in the case that the user is iterating through instances and takes all samples to an instance that is NOT_ALIVE and has no writers in which case that action may actually free that instance, "invalidating" the handle of that instance.


Proposed Resolution:


Allow passing a handle that does not correspond to any instance currently on the DataReader to read_next_instance/take_next_instance. This handle should be sorted in a deterministic way with regards to the other handles such that the iteration is not interrupted.
Proposed Revised Text:


Section 2.1.2.5.3.16 read_next_instance


Replace the paragraph: 


This operation implies the existence of some total order 'greater than' relationship between the instance handles. The specifics of this relationship are not important and are implementation specific. The important thing is that, according to the middleware, all instances are ordered relative to each other. This ordering is between the instances, that is, it does not depend on the actual samples received or available. For the purposes of this explanation it is 'as if' each instance handle was represented as a unique integer.


With:


This operation implies the existence of a total order 'greater-than' relationship between the instance handles. The specifics of this relationship are not all important and are implementation specific. The important thing is that, according to the middleware, all instances are ordered relative to each other. This ordering is between the instance handles: It should not depend on the state of the instance (e.g. whether it has data or not) and must be defined even for instance handles that do not correspond to instances currently managed by the DataReader. For the purposes of the ordering it should be 'as if' each instance handle was represented as a unique integer.


Section 2.1.2.5.3.16 read_next_instance


Remove the paragraph:


The behavior of the read_instance operation follows the same rules as the read operation regarding the pre-conditions and post-conditions for the data_values and sample_infos collections. Similar to read, the read_instance operation may 'loan' elements to the output collections which must then be returned by means of return_loan.


Replace the paragraph:


This operation may return BAD_PARAMETER if the InstanceHandle_t a_handle does not correspond to an existing data-object known to the DataReader. If the implementation is not able to check invalid handles, then the result in this situation is unspecified.


With


Note that it is possible to call  the 'read_next_instance' operation with an instance handle that does not correspond to an instance currently managed by the DataReader. This is because as stated earlier the 'greater-than' relationship is defined even for handles not managed by the DataReader. One practical situation where this may occur is when an applications is iterating though all the instances,  takes all the samples of a NOT_ALIVE_NO_WRITERS instance, returns the loan (at which point the instance information may be removed, and thus the handle becomes invalid), and tries to read the next instance.


Section 2.1.2.5.3.17 take_next_instance


Replace the paragraph:


This operation may return BAD_PARAMETER if the InstanceHandle_t a_handle does not correspond to an existing data-object known to the DataReader. If the implementation is not able to check invalid handles, then the result in this situation is unspecified.


With


Similar to the operation read_next_instance (see Section 2.1.2.5.3.16) it is possible to call  take_next_instance with an instance handle that does not correspond to an instance currently managed by the DataReader.


Section 2.1.2.5.3.18 read_next_instance_w_condition


Replace the paragraph:


This operation may return BAD_PARAMETER if the InstanceHandle_t a_handle does not correspond to an existing data-object known to the DataReader. If the implementation is not able to check invalid handles, then the result in this situation is unspecified.


With


Similar to the operation read_next_instance (see Section 2.1.2.5.3.16) it is possible to call  read_next_instance with an instance handle that does not correspond to an instance currently managed by the DataReader.


Section 2.1.2.5.3.19 take_next_instance_w_condition
Replace the paragraph:


This operation may return BAD_PARAMETER if the InstanceHandle_t a_handle does not correspond to an existing data-object known to the DataReader. If the implementation is not able to check invalid handles, then the result in this situation is unspecified.


With


Similar to the operation read_next_instance (see Section 2.1.2.5.3.16) it is possible to call  take_next_instance_w_condition with an instance handle that does not correspond to an instance currently managed by the DataReader.

Allow passing a handle that does not correspond to any instance currently on the DataReader to read_next_instance/take_next_instance. This handle should be sorted in a deterministic way with regards to the other handles such that the iteration is not interrupted.

Clarification to when a instance resource can be reclaimed in READER_DATA_LIFECYCLE QoS section


Summary:


In Section 2.1.3.22 (READER_DATA_LIFECYCLE QoS) the fourth paragraph mention how "the DataReader can only reclaim all resources for instances that instance_state = NOT_ALIVE_NO_WRITERS and for which all samples have been 'taken'".
This should be corrected to state "for instances for which all samples have been 'taken' and either instance_state = NOT_ALIVE_NO_WRITERS or instance_state = NOT_ALIVE_DISPOSED and there are no 'live' writers".
In light of this the statement in the last paragraph stating that once the state becomes NOT_ALIVE_DISPOSED after the autopurge_disposed_samples_delay elapses, "the DataReader will purge all internal information regarding the instance; any untaken samples will also be lost" is not entirely true.  If there are other 'live' writers, the DataReader will maintain the state on the instance of which DataWriters are writing to it.


We should change the "will purge all" to "may purge all" or even "will purge".  Alternatively, we could describe in further detail when it "will purge all", i.e. when there are no 'live' writers.


The biggest thing here is to decide whether the instance lifecycle can end directly from the NOT_ALIVE_DISPOSED state (as Figure 2-11 currently states) or whether we must force it to go though the NOT_ALOVE_NO_WRITES; that is, in the case where the last writer unregisters a disposed instance do we transition to NOT_ALIVE_NO_WRITERS+NOT_ALIVE_DISPOSED or do we finish the lifecycle directly without notifying the user (as it is indicated now)


We think the current behavior is better because from the application reader point of view, the instance does not exists once it DISPOSED, the fact that we keep the instance state such that we can retain ownership is a detail inside the middleware, so it would be unnatural to get a further indication that the instance (that it no longer knows about) has now no writers. 


We suggest the proposed changes should reflect this point of view.


Proposed Resolution:


Make the suggested corrections:


(1) Correct when readers can claim resources to include NOT_ALIVE_DISPOSED state when there are no live writers. So we always reclaim when there are no writers and all the samples for that instance are taken; these samples will include a sentinel mata-sample with an instance state that will be either NOT_ALIVE_NO_WRITERS or NOT_ALIVE_DISPOSED


(2) Clarify that the auto_purge_disposed samples removes only the samples, but not the instance; the instance will only removed in the above case.
Proposed Revised Text:


Section 2.1.3.22 READER_DATA_LIFECYCLE QoS


Replace the paragraph:  


Under normal circumstances the DataReader can only reclaim all resources for instances that instance_state = NOT_ALIVE_NO_WRITERS and for which all samples have been 'taken.'


With


Under normal circumstances the DataReader can only reclaim all resources for instances for which there are no writers and for which all samples have been 'taken.' The last sample the DataReader will have taken for that instance will have an instance_state of either  NOT_ALIVE_NO_WRITERS or NOT_ALIVE_DISPOSED depending on whether  the last writer that had ownership of the instance disposed it or not. Refer to Figure 2-11 for a statechart describing the transitions possible for the instance_state.


In the Paragraph starting with "The autopurge_nowriter_samples_delay defines.." 
Replace 


once its view_state becomes NOT_ALIVE_NO_WRITERS


With


once its instance_state becomes NOT_ALIVE_NO_WRITERS


Replace the paragraph:


The autopurge_disposed_samples_delay defines the maximum duration for which the DataReader will maintain information regarding an instance once its view_state becomes NOT_ALIVE_DISPOSED. After this time elapses, the DataReader will purge all internal information regarding the instance; any untaken samples will also be lost


With


The autopurge_disposed_samples_delay defines the maximum duration for which the DataReader will maintain samples for an instance once its instance_state becomes NOT_ALIVE_DISPOSED. After this time elapses, the DataReader will purge all samples for the instance.

Make the suggested corrections:
.(1) Correct when readers can claim resources to include NOT_ALIVE_DISPOSED state when there are no live writers. So we always reclaim when there are no writers and all the samples for that instance are taken; these samples will include a sentinel mata-sample with an instance state that will be either NOT_ALIVE_NO_WRITERS or NOT_ALIVE_DISPOSED
(2) Clarify that the auto_purge_disposed samples removes only the samples, but not the instance; the instance will only removed in the above case.

Summary:


In Section 2.1.2.5.2.11 (notify_datareaders) the first sentence states
This operation invokes the operation on_data_available on the DataReaderListener objects attached to contained DataReader entities containing samples with SampleState 'NOT_READ' and any ViewState and InstanceState.
In Section 2.1.4.2.2 (Changes in Read Communication Statuses) it states in the first paragraph that the "StatusChangedFlag becomes false again when all samples are removed from the responsibility of the middleware via the take operation on the proper DataReader entities".
In Figure 2-16 in the same section, the transition from the TRUE state to FALSE is accompanied by the condition "DataReader:take[all data taken by application]".


However, in Section 2.1.4.4 (Condition and Wait-sets) in the last step in the general use pattern deals with using the result of the wait operation and in the third sub-bullet it states how if the wait unblocked due to a StatusCondition and the status change is DATA_AVAILABLE, the appropriate action is to call read/take on the relevant DataReader.
If only a take of all samples will reset the status, then simply calling read in this use pattern will not reset the status and the given general use pattern will actual spin.



Proposed Resolution:


The actual condition for the StatusChangedFlag to become false should then be that the status has been considered read/accessed by the user.  This should be considered as such when the listener for a Read Communication Status is called similar to Plain Communication Statuses (see T#6).
In addition, it should be such if the user calls read/take on the associated DataReader.


Subscriber's DATA_ON_READERS status is reset if the on_data_on_readers is called (same as for all listeners).


In addition Subscriber's DATA_ON_READERS status is reset if the user calls read or take on any of the DataReaders belonging to the Subscriber.
In addition, the Subscriber's DATA_ON_READERS status is also reset if the on_data_available callback is called on the DataReaderListener.  This is needed such that if the application calls  notify_datareaders  it will reset the status.
The inverse, i.e. resetting the DATA_AVAILABLE status when the on_data_on_readers callback is called) does not happen.


Proposed Revised Text:


Section 2.1.2.5.2.11 notify_datareaders


In the first sentence, change


DataReader entities containing samples with SampleState 'NOT_READ' and any ViewState and InstanceState


To


DataReader entities with a DATA_AVAILABLE status that is considered changed.


Section 2.1.4.2.2 Changes in Read Communication Statuses


Change the last sentence of the first paragraph from
The StatusChangedFlag becomes false again when all the samples are removed from the responsibility of the middleware via the take operation on the proper DataReader entitites.


To


The DATA_AVAILABLE StatusChangedFlag becomes false again when either the corresponding listener operation (on_data_available ) is called or a read or take operation is called on the associated DataReader. 


The DATA_ON_READERS StatusChangedFlag becomes false again when any of the following occurs:


o       The corresponding listener operation (on_data_on_readers) is called.
o       The on_data_available listener operation is called on any DataReader belonging to the Subscriber.
o       The read or take on any DataReader belonging to the Subscriber


In Figure 2-16 


Introduce two figures one for the DATA_ON_READERS and the other for the DATA_AVAILABLE

The actual condition for the StatusChangedFlag to become false should then be that the status has been considered read/accessed by the user.  This should be considered as such when the listener for a Read Communication Status is called similar to Plain Communication Statuses (see ISSUE# [T#6).
In addition, it should be such if the user calls read/take on the associated DataReader.
Subscriber's DATA_ON_READERS status is reset if the on_data_on_readers is called (same as for all listeners).
In addition Subscriber's DATA_ON_READERS status is reset if the user calls read or take on any of the DataReaders belonging to the Subscriber.
In addition, the Subscriber's DATA_ON_READERS status is also reset if the on_data_available callback is called on the DataReaderListener.  This is needed such that if the application calls  notify_datareaders  it will reset the status.
The inverse, i.e. resetting the DATA_AVAILABLE status when the on_data_on_readers callback is called) does not happen