re-ADA for C4ISR

1. re-ADA for C4ISR Sheldon X. Liang, PhD Computer Science

2. re-ADA for C4ISR Reliable Ada-based Descriptive Architecture via a Quantifiable Interoperating Model  Why re-ADA?  Scalable re-ADA  Formal re-ADA  A C4ISR Case Study  Practical re-ADA  Quantifiable re-ADA

3. re-ADA for C4ISR Why re-ADA? Excellence and Drawbacks • The International Language for SE • The Language for a Complex World • The first ISO-standardized OOPL • The Quantitative ADL for C4ISR What an embarrassing – a C++ or Java programmer who has expertise in OOP may not be able to write code in Ada95 Why? Ada95 has the meaning of OOP but does not have the class-like form

4. re-ADA for C4ISR Why re-ADA? Expectations and Accomplishments Not just OOPL But ADL re-ADA Perfect OOPL Like Java/C++ re-Ada OOPL Mean / Form Ada95

5. Quantitatively Modeling Dependability (RT) Reliable Architecture for C4ISR Interoperability CORBA-based Infrastructure CSP-based Semantics Class-like OODM C++/Java-like Class construct ISO OOPL re-ADA for C4ISR Why re-ADA? Approach against Drawbacks C4ISR re-ADA re-Ada Ada95

6. re-ADA for C4ISR Why re-ADA? Quantitatively Modeling Interoperability Dependable Interoperability with respect to RT constraints can be monitored at runtime

7. re-ADA for C4ISR Scalable re-ADA An Evolutionary Approach System Interoperability Dependable Interoperation Interoperability for C4ISR Information Interoperability Effective Intercommunication Software Interoperability Seamless Interconnection

8. re-ADA for C4ISR Scalable re-ADA An Evolutionary Approach • re-ADA aims to enable legacy (heterogeneous) components to work together over the network by using interoperability technologies: • data unification, • message-sending, and • interoperable shell.

9. re-ADA for C4ISR Scalable re-ADA An Evolutionary Approach • Seamless Interconnection Software interoperability refers to inconsistent representation of the same real world entity in various legacy component systems. By data unification and OOMI (Object-Oriented Model for Interoperability), the heterogeneous legacy component can be abstracted as a coarser-grained object that is unified into a standard representation.

10. re-ADA for C4ISR Scalable re-ADA An Evolutionary Approach • Seamless Interconnection • Effective Intercommunication Information interoperability refers to two message-sending ways: Simple Message Sending (SMS) and Remote Method Invocation (RMI) via message-sending. For the sake of effective SMS/RMI between distributed components, a set of explicit functionalities needs to realize effective intercommunication.

11. re-ADA for C4ISR Scalable re-ADA An Evolutionary Approach • Seamless Interconnection • Effective Intercommunication

12. re-ADA for C4ISR Scalable re-ADA An Evolutionary Approach • Seamless Interconnection • Effective Intercommunication • Dependable Interoperation System interoperability refers to joint task execution over the network that is realized via message-sending in a dependable way Dependable Interoperability with respect to RT constraints can be monitored at runtime

13. re-ADA for C4ISR Scalable re-ADA An Evolutionary Approach System Interoperability Dependable Interoperation Interoperability for C4ISR Information Interoperability Effective Intercommunication Software Interoperability Seamless Interconnection

14. re-ADA for C4ISR Scalable re-ADA An Evolutionary Approach

15. re-ADA for C4ISR Formal re-ADA Quantitative Interoperating Model • Formal dependability model Constructing formal dependability model for C4ISR the process that incorporates three views of dependability throughout software development process  Conceptual view  Quantitative view  Semantic view acquiring dependability requirements that refer to fundamental attributes: mapping attributes into measurable constraints binding attributes onto architectural artifacts, like the role, style, and protocol

16. re-ADA for C4ISR Formal re-ADA Quantitative Interoperating Model • Formal dependability model Constructing formal dependability model for C4ISR the process that incorporates three views of dependability throughout software development process  Conceptual view  Quantitative view  Semantic view

17. re-ADA for C4ISR Formal re-ADA Quantitative Interoperating Model • Formal dependability model Dependable Interoperation between two collaborative components in production-consumption (Prepare Respond) pattern. Three kinds of timing constraints have been developed to reflect dependability attributes, such as availability or reliability:  MET (maximum execution time) for client side,  MRT (maximum response time) for server side, and  LATENCY (maximum delay during communication)

18. re-ADA for C4ISR Formal re-ADA Quantitative Interoperating Model • Formal dependability model The client prepares message (constrained by MET), and sends it out as a RMI message (constrained by LATENCY), and then expects response from the server (constrained by MRT) Client/Publisher Server/Subscriber

19. re-ADA for C4ISR Formal re-ADA Quantitative Interoperating Model • Formal dependability model

20. re-ADA for C4ISR Formal re-ADA Quantitative Interoperating Model • Formal dependability model • Real-time constraints monitor In distributed computing environment, multi-threads dominate the interoperation between Publisher and Subscriber. , and Agent that plays a role of Publisher that delivers message for response, and a role Subscriber that observes message by giving response. Real-time constraints can be monitored at runtime on the basis of multi-threading communication.

21. re-ADA for C4ISR Formal re-ADA Quantitative Interoperating Model • Formal dependability model • Real-time constraints monitor (a) Preparation for delivering constrained by MET (b) Response for observing constrained by MRT (c) intercommunication constrained by LATENCY

22. re-ADA for C4ISR Formal re-ADA Quantitative Interoperating Model • Formal dependability model • Real-time constraints monitor • A C4ISR case study A C4ISR system is generally composed of component systems in military applications – for instance, airplanes in the sky, warships in the sea, submarines underwater or missiles on the land, all of which connects with the battle management infrastructure.

23. re-ADA for C4ISR Formal re-ADA Quantitative Interoperating Model • Formal dependability model • Real-time constraints monitor • A C4ISR case study Dependable interoperability makes a lot of sense with C4ISR in regards to the collaborative interoperation of military commands in a coalition. C4ISR is usually established on the military internetworking infrastructure (network-centric warfare).

24. re-ADA for C4ISR Formal re-ADA A C4ISR Case Study

25. re-ADA for C4ISR Formal re-ADA A C4ISR Case Study C4ISR architectures aim to improve capabilities by enabling the quick synthesis of “go-to-war” requirements with sound investments leading to the rapid employment of improved operational capabilities, and enabling the efficient engineering of warrior systems.

26. re-ADA for C4ISR Formal re-ADA A C4ISR Case Study

27. re-ADA for C4ISR Practical re-ADA Class-like OOP in Ada95 • Syntactic class construct In re-ADA, all heterogeneous components are required to play a specific role -- either a Publisher or a Subscriber, or both. So we need an up-most ancestor class Role for defining generalized features for all descendant classes to inherit from, such as tagged, Controlled, Initialize and Finalize (Ada95/Ada05). In this Ada-based design approach, the pristine notion of class is introduced as a major program element in a package in support for more straightforward object-oriented construction; and through inheritance, many descendant classes can be derived.

28. re-ADA for C4ISR Practical re-ADA Class-like OOP in Ada95 • Syntactic class construct An Ada-based pristine class in an Ada package is treated as program unit that encloses properties (data & subprograms)

29. re-ADA for C4ISR Practical re-ADA Class-like OOP in Ada95 • Syntactic class construct There are five rules that have been developed as key points upon which a pre-compiler can be made to translate the pristine class into Ada95/Ada05 code. R-1 class and type: a class name always implies two types; R-2 member method: a member method is an access to a subprogram R-3 constructor and destructor: They are Initialize and Finalize R-4 prefix “Current” access within member method’s body: R-5 object designator: “Obj<-” is introduced to to choose the member method. R-6 Interoperation via Collaborator: a pair of publisher and subscriber will share a task that collaborates on the interoperation. R-7 Concurrent computation and synchronous rendezvous: under the monitor of the collaborator, there are two tasks working for the publisher and the subscriber, respectively.

30. re-ADA for C4ISR Practical re-ADA Class-like OOP in Ada95 • Syntactic class construct

31. re-ADA for C4ISR Practical re-ADA Class-like OOP in Ada95 • Syntactic class construct • Inheritance and polymorphism The Collaborator’s connection provides a useful means by which a concrete component is assigned to play a specific role (Publisher or Subscriber). In terms of role-assignment, there are two ways to “glue” the concrete component on the specific role: Object embedment, and Object derivation. The object derivation is to derive a new class and override the existing member method (predefined by the framework) – for instance, procedure Prepare is abstract. An abstract member method represents polymorphism and dynamic binding.

32. re-ADA for C4ISR Practical re-ADA Class-like OOP in Ada95 • Syntactic class construct • Inheritance and polymorphism Through inheritance, the subclass can redefine a subprogram by overriding it, which means polymorphism

33. re-ADA for C4ISR Practical re-ADA Class-like OOP in Ada95 • Syntactic class construct • Inheritance and polymorphism • Computational collaboration We now take a closer look at the C4ISR case study. Although we already have an outlined configuration with Ada-based descriptive architecture, here we apply the 6th rule and the 7th rule to translate the Ada-based description into real Ada95 code

34. re-ADA for C4ISR Practical re-ADA Class-like OOP in Ada95  Computational collaboration Code and Semantics

35. re-ADA for C4ISR Quantifiable re-ADA Conclusion • C4ISR: Reliable Interoperability C4ISR architectures aim to improve capabilities by enabling the quick synthesis of “go-to-war” requirements, and enabling the efficient engineering of warrior systems • QIM/re-ADA: Quantitatively Modeling Architecture The QIM/re-ADA provides the explicit loci around which designers are able to stress and evaluate the non-functional properties during architectural design. • re-ADA/CORBA:Descriptive Architecture & Infrastructure re-ADA/CORBA maps dependability into quantifiable constraints as architectural (semantic) properties that are constructed on the basis of CORBA, so that dependable interoperation can be verified at runtime.

36. re-ADA for C4ISR Questions