re-ADA for C4ISR

re-ADA for C4ISR

Sheldon X. Liang, PhD

Computer Science

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

The International Language for SE The Language for a Complex World The first ISO-standardized OOPL The Quantitative ADL for C4ISR

re-ADA for C4ISR

Why re-ADA? Excellence and Drawbacks

Why? Ada95 has the meaning of OOP but does not have the class-like form

What an embarrassing – a C++ or Java programmer who has expertise in OOP may not be able to write code in Ada95

re-ADA for C4ISR

Why re-ADA? Expectations and Accomplishments

OOPLMean / Form

Perfect OOPLLike Java/C++

Not just OOPLBut ADL

re-Adare-Ada

Ada95Ada95

re-ADAre-ADA

re-ADA for C4ISR

Why re-ADA? Approach against Drawbacks

re-Adare-Ada

Ada95Ada95ISO

OOPL

re-ADAre-ADA

Class-likeOODM

C++/Java-like

Class constructC++/Java-like

Class construct

CSP-based

SemanticsCSP-based

Semantics

CORBA-based

InfrastructureCORBA-based

Infrastructure

Quantitatively Modeling Dependability (RT)

Quantitatively Modeling Dependability (RT)

Reliable Architecture for C4ISR

Interoperability

C4ISR

re-ADA for C4ISR

Why re-ADA? Quantitatively Modeling Interoperability

Dependable Interoperability with respect to RT constraintscan be monitored at runtime

re-ADA for C4ISR

Scalable re-ADA An Evolutionary Approach

Interoperability

for

C4ISR

Interoperability

for

C4ISR

SystemInteroperability

InformationInteroperability

DependableInteroperation

EffectiveIntercommunication

SoftwareInteroperability

SeamlessInterconnection

re-ADA for C4ISR


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.

Seamless Interconnection

re-ADA for C4ISR


Software interoperability refers to inconsistent representation of the same real world entity in various legacy component systems.

By data unification andOOMI (Object-Oriented Model for Interoperability), the heterogeneous legacy component can be abstracted as a coarser-grained object that is unified into a standard representation.

Seamless Interconnection Effective Intercommunication

re-ADA for C4ISR


For the sake of effective SMS/RMI betweendistributed components, a set of explicit functionalities needs to realize effective intercommunication.

Information interoperability refers to two message-sending ways: Simple Message Sending (SMS) and Remote Method Invocation (RMI) via message-sending.

Seamless Interconnection Effective Intercommunication

re-ADA for C4ISR


Seamless Interconnection Effective Intercommunication Dependable Interoperation

re-ADA for C4ISR


System interoperability refers to joint task execution over the network that is realized via message-sending in a dependable wayDependable Interoperability with respect to RT constraints

can be monitored at runtime

re-ADA for C4ISR


Interoperability

for

C4ISR

Interoperability

for

C4ISR

SystemInteroperability

InformationInteroperability

DependableInteroperation

EffectiveIntercommunication

SoftwareInteroperability

SeamlessInterconnection

re-ADA for C4ISR


Formal dependability model

re-ADA for C4ISR

Formal re-ADA Quantitative Interoperating Model

Constructing formal dependability model for C4ISR the process that incorporates three views of dependability throughout software development process

Quantitative view Conceptual view Semantic view

acquiring dependability requirementsthat refer to fundamental attributes:

mapping attributes into measurable constraints

binding attributes onto architectural artifacts, like the role, style, and protocol


re-ADA for C4ISR


Constructing formal dependability model for C4ISR the process that incorporates three views of dependability throughout software development process

Quantitative view Conceptual view Semantic view


re-ADA for C4ISR


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)


re-ADA for C4ISR


Client/Publisher Server/Subscriber

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)


re-ADA for C4ISR


Formal dependability model Real-time constraints monitor

re-ADA for C4ISR


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.

Formal dependability model Real-time constraints monitor

re-ADA for C4ISR


(a) Preparation for deliveringconstrained by MET

(b) Response for observingconstrained by MRT

(c) intercommunication constrained by LATENCY

Formal dependability model Real-time constraints monitor A C4ISR case study

re-ADA for C4ISR


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.

Formal dependability model Real-time constraints monitor A C4ISR case study

re-ADA for C4ISR


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).

re-ADA for C4ISR

Formal re-ADA A C4ISR Case Study

re-ADA for C4ISR


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.

re-ADA for C4ISR


Syntactic class construct

re-ADA for C4ISR

Practical re-ADA Class-like OOP in Ada95

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.


re-ADA for C4ISR


An Ada-based pristine class in an Ada package is treated as program unit that encloses properties (data & subprograms)


re-ADA for C4ISR


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.


re-ADA for C4ISR


Syntactic class construct Inheritance and polymorphism

re-ADA for C4ISR


The Collaborator’s connection provides a useful means by which a concrete component is assigned to play a specific role (Publisher orSubscriber). 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.

Syntactic class construct Inheritance and polymorphism

re-ADA for C4ISR


Through inheritance, the subclass can redefine a subprogram by overriding it, which means polymorphism

Syntactic class construct Inheritance and polymorphism Computational collaboration

re-ADA for C4ISR


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

re-ADA for C4ISR

Practical re-ADA Class-like OOP in Ada95 Computational collaboration

Code and Semantics

C4ISR: Reliable InteroperabilityC4ISR 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 ArchitectureThe 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.

re-ADA for C4ISR

Quantifiable re-ADA Conclusion

re-ADA for C4ISR

Questions

re-ADA for C4ISR

Documents

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