Omg issue Number

Disposition: Resolved

OMG Issue No: 11852

Title: AADL pre-declared property set representation with MARTE

Source:

THALES (M. Faugère, [e-mail])

Summary:

The representation of AADL properties with UML Notes, does not provide the AADL capabilities of the Properties language. Annotations in notes are not formal, as users use a free-text zone without any constraints for the annotated elements, and syntax checking. Furthermore, most of the AADL Properties defined in the Predeclared Property Set annex (AADL spec.) are already existing in MARTE stereotype attributes. The more appropriate way is to use these attributes to model AADL properties. However, additional problems rise from this approach:

1. 
   Not all the AADL properties exist in MARTE.
   
2. 
   Some enumeration types existing in MARTE do not contain the options supported by AADL.
   
3. 
   Stereotype attributes are not always annotated in the same model elements (according to the mapping MARTE-AADL at the conceptual level).
   

This aspect can be solved in at least two ways:

1. 
   We add the required stereotype attributes in the MARTE spec.
   
2. 
   New stereotypes are created in this annex only to support AADL.
   

While the first option could not be in the scope of MARTE (we cannot align MARTE to all other language in the domain!), the second one requires to follow a set of formal rules to create the new stereotypes (naming, extended UML metaclasses, etc.) A third option is to create stereotypes for all the AADL concepts, but inheriting from MARTE concepts. An optimal solution should be evaluated with regard to criteria such as: tool reusability, automation of model transformations, timelines, etc. The third option goes along with the question of having an explicit profile for AADL, with AADL stereotype (or at least AADL profile label for MARTE stereo types that are identical to AADL). Do we need to introduce a new stereotype just because we have to add some properties to a MARTE stereo type? AADL allows users to introduce new properties through property sets. In MARTE terminology, users can introduce new stereotypes that carry properties specific to an analysis framework. Those we need to be able to associate with the base concepts of describing an embedded architecture (what we call core language). What would be a good approach and guidance for doing so? In that sense there are two issues: 1) describe what mechanisms are available to allow users to extend the base modelling language of AADL/MARTE – in essence meta modelling capabilities). In AADL we have an explicit textual representation in addition to extending the meta model of AADL, while in MARTE it is solely done through meta modelling. 2) capture specific sets of standardized (and not yet standardized sets of properties).
Resolution:
According to the implicit MARTE modeling process where modeling and analysis features are modeled by distinct features in separate diagrams, most (80%) of the AADL pre declared properties found their equivalent in MARTE. The complementary part will be explicitly modeled by the end user using the “Nfp” concept. The following table presents the mapping between the AADL pre-declared property set and their equivalent in MARTE.

Revised Text:
To be added after the “Component and associated features representation” table concerning the Data component section 3.3.4.
AADL data component properties

AADL properties		Marte Design	Marte SW/HW platform	Marte Analysis
Shared data aspect		MutualExclusionRe-source stereotype	swMutualExclusionResource stereotype	swMutualExclusionResource stereotype
Concurrency_Control_Pro-tocol: enumeration		NA		concurrentAccessProtocol stereotype attribute
	Priority_Inheritance			“PIP” enumeration literal of “ConcurrentAccessProtocol-Kind” enumerate
	Interrupt_Masking			New issue raised
	Priority_Ceiling			“PCP” enumeration literal of “ConcurrentAccessProtocol-Kind” enumerate
	Maximum_Priority			New issue raised
Data access via interface		Resource, ConcurrencyResource, ProcessingResource of GRM depending on the user’s precision requirements	Associated SRM equivalent concepts i.e. swConcurrencyResource, etc

To be added after the “Component and associated features representation” table concerning the Subprogram component section 3.3.5.

AADL subprogram component

AADL properties		Marte Design		Marte Analysis
Compute_execution_time: Time_range		NA	NA		“ExecTime: NFPDuration[*]” attribute on SaStep or SaCommStep stereotype
Compute_Deadline					“Deadline: NFPDuration[]” attribute on SaStep or SaCommStep stereotype
Queued_Processing_Protocol enumaration					“MessageQueuePolicyKind” attribute
	FIFO				“FIFO” enumeration literal from “QueuePolicyKind” enumerate
	Other				“Other” enumeration literal from “QueuePolicyKind” enumerate

To be added after the “Component and associated features representation” table concerning the Thread component section 3.3.2.

AADL Thread component

AADL properties		Marte Design	Marte SW/HW platform	Marte Analysis
Dispatch protocol: enumeration		NA	NA	Specified at the WorkloadEvent concept triggering the SaScenario
	Periodic			“PeriodicPattern” enumeration literal selected for “Pattern” attribute for the WorkloadEvent stereotype
	Sporadic			“SporadicPattern” enumeration literal selected for “Pattern” attribute for the WorkloadEvent stereotype.
	Aperiodic			“AperiodicPattern” enumeration literal selected for “Pattern” attribute for the WorkloadEvent stereotype
	Background			New issue raised
Period: Time				“Period” attribute from the “PeriodicPattern” attribute specified by the WorkloadEvent stereotype
Deadline: Time (inherited from period)				At this level, the same as “Period” attribute defined above
Compute_execution_time				Computed from the different “Steps” concepts supported by the thread; shall be defined in scenarios
Compute_deadline				Computed from the different “SaSteps” supported by the thread; shall be defined in scenarios
Initialize_execution_Time and Initialize_deadline				Specific “execTime” and “deadline” attributes from SaStep stereotype corresponding on mode switch operations defined in the SwPlatform model
Active_execution_time (specific for mode switch) and Active_deadline (specific for mode switch)				Specific “execTime” and “deadline” attributes from SaStep stereotype corresponding on mode switch operations defined in the Swplatform model
Deactive_execution_time (specific for mode switch) and Desactive_deadline (specific for mode switch)				Specific “execTime” and “deadline” attributes from SaStep stereotype corresponding on mode switch operations defined in the Swplatform model
Recover_execution_time (specific for mode fault handling) and Recover_deadline (specific for mode fault handling)				Specific “execTime” and “deadline” attributes from SaStep stereotype corresponding on mode switch operations defined in the Swplatform model
Finalize_execution_time and Finalize_deadline				Specific “execTime” and “deadline” attributes from SaStep stereotype corresponding on mode switch operations defined in the Swplatform model
Synchronized_component				Nfp stereotyped attribute defined by the end-user
Active_thread_handling_proto-col (specific to mode switch): ex abort, complete_one_flush_queue, complete_one_transfer_queue,complete_one_preserve_queue, complete_all				Nfp stereotyped attribute with associated end-user defined enumeration

To be added after the “Component and associated features representation” table concerning the Process component section 3.3.1.
AADL Process component

AADL properties		Marte Design	Marte SW/HW platform		Marte Analysis
Scheduling_protocol		NA		NA	Specified by the “schedPolicy” attribute of Scheduler stereotype
	Ex: EDF, RMS, SporadicServer, SlackServer, ARINC653				Scheduler and SchedulableResource stereotypes modeling with associated scheduling policy kinds, and scheduling parameters.
load_time and load_deadline					Specific “execTime” and “deadline” attributes from SaStep stereotype corresponding to operations defined in the Swplatform model
Period and deadline are specified for inheritance					Period and deadlines are specified at the thread level on WorkloadEvent and SaSteps.

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To be added after the “Component and associated features representation” table concerning the Processor component section 3.4.1.
AADL Processor component

AADL properties	Marte Design	Marte SW/HW platform		Marte Anaysis
Thread_limit			AssociationEnd cardinality between ” Scheduler” and “swSchedulingResources” concepts modelized in the sw Platform
Assign_time: Time				Nfp stereotyped attribute defined by the end-user
Assign_byte_Time: Time				Nfp stereotyped attribute defined by the end-user
Assign_fixed_Time: Time				Nfp stereotyped attribute defined by the end-user
Clock_Jitter				Nfp stereotyped attribute defined by the end-user
Clock_period				Nfp stereotyped attribute defined by the end-user
Clock_Period_Range				“Op_frequencies” attribute from HwProcessor stereotype

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To be added after the “Component and associated features representation” table concerning the Memory component section 3.4.2.
AADL Memory component

AADL properties	Marte Design	Marte SW/HW platform		Marte Analysis
MemoryProtocol (R,W,RW)			“MemoryBroker” concept allocated on “HwMemory”	“AccessPolicy” attribute from “MemoryBroker” stereotype
Read_Time:Time[]				“ExecTime: NFPDuration[*]” attribute on SaStep or SaCommStep stereotype
Write_Time:Time[]				“ExecTime: NFPDuration[*]” attribute on SaStep or SaCommStep stereotype

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To be added after the “Component and associated features representation” table concerning the Bus component section 3.4.3.
AADL Bus component

AADL properties	Marte Design	Marte SW/HW platform		Marte Analysis
Propagation_delay				Nfp stereotyped attribute defined by the end-user
Transmission_Time				“ExecTime: NFPDuration[*]” attribute on SaStep or SaCommStep stereotype
Allowed_Message_Size				“MessageSizeElements” attribute on MessageComResource stereotype

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To be added after the “Component and associated features representation” table concerning the Port component section 3.6.1.

AADL Port component

AADL properties	Marte Design	Marte SW/HW platform		Marte Analysis
Compute_execution_time				Time and Deadline are either specified in the associated communication media or component
Compute_Deadline
Queue_size				“MessageQueueCapacityElements” attribute on MessageComResource stereotype
Queue_Processing_proto-col				“Mechanism” attribute on MessageComResource stereotype available values are “MessageQueue, Pipe, BlackBoard, undef, other)
Overflow_handling_proto-col				Nfp stereotyped attribute defined by the end-user, typed bt end-user defined enumeration
Dequeued_protocol				Nfp stereotyped attribute defined by the end-user, typed bt end-user defined enumeration

To be added after the “Component and associated features representation” table concerning the Flow component section 3.8.

AADL Flow component

AADL properties	Marte Design	Marte SW/HW platform		Marte Analysis
Latency				See end-to-end flow latency
Throughput				See end-to-end flow throughput

To be added after the “Component and associated features representation” table concerning the Flow component section 3.8.

AADL End_to_end Flow component

AADL properties	Marte Design	Marte SW/HW platform		Marte Analysis
Expected_Latency				“End2EndD: NFPDuration[*]” attribute on SaEnd2EndFlow stereotype with qualifier attribute “SourceKind” set to “req”
Actual_Latency				“End2EndT: NFPDuration[*] “attribute on “SaEnd2EndFlow” with qualifier attribute “SourceKind” set to “est”
Expected_Throughput				“Throughput: NFP_Frequency[*]” attribute on “Sa/GaScenario” with qualifier attribute “Sourcekind” set to “req”
Actual_Throughput				“Throughput: NFP_Frequency[*]” attribute on “Sa/GaScenario” with qualifier attribute “Sourcekind” set to “est”

Disposition: Resolved