Object-oriented specification of coordinated collaboration

Electronic Notes in Theoretical Computer Science, 2009

The ARC (Actor, Role, Coordinator) model addresses the coordination requirements of open, distributed applications deployed in dynamic environments. This paper introduces the ARC programming model and the ARC-PL programming language, including the syntax and informal semantics of new language constructs designed to enable modular coordination in the ARC model. Several well-known problems are solved to illustrate the expressiveness and modularity of the ARC programming model.

Electronic Notes in Theoretical Computer Science, 2003

Developing concurrent applications in cooperative environments is an arduous task. This is mainly due to the fact that it is very difficult to specify the synchronized interaction between the entities composing the system. Using coordination models makes this task easier. The latest trends in this area suggest that to manage the successful implementation of complex systems, coordination models must support some key features regarding the coordination constraints: their separated specification, their unanticipated evolution and their dynamic change. However, supporting these features is not only a technical challenge: it must be also guaranteed that the application of a separately specified coordination pattern to a set of encapsulated entities, or the change of the coordination constraints in an already running software system will not produce semantic errors. This is just the problem focused in this paper. In particular, a method for generating formal interpretable specifications reproducing coordinated environments is presented. The method is based on the Coordinated Roles coordination model and makes use of Maude as a formal language. The benefits obtained are: (i) easy specification using the coordination model syntax, (ii) automatic generation of the corresponding formal specification and (iii) simulation of system behaviour.

2002

Collaborations (between objects) are increasingly being recognized as fundamental building blocks to structure object-oriented design, and they have made their way into UML. But very often the first class aspect of a design level collaboration is lost during the detailed design process, making it difficult to keep good traceability between the design and the implementation. The problem is not simple, because for any given collaboration abstraction, there might be several possible design solutions depending on the many non-functional forces impacting a given application. We propose a process and an architecture in which the notion of collaboration is preserved from analysis to design and implementation, while allowing the designer to change his mind about which particular design trade-off is selected in order to face changing non-functional requirements during maintenance. We illustrate our approach with a case study inspired by the real example of a large French railway company attempting to adapt a flight reservation system to its own context.

1995

1996

In this article we present the concurrent object-oriented specification language CO-OPN/2 which extends the CO-OPN (Concurrent Object Oriented Petri Nets) formalism, destined to support the development of large distributed systems. The development of distributed applications has recently been the subject of intensive research, due to potential benefits that can be expected to offer in increasing reliability and overall performance of computer processing. One way of improving the effectiveness of the distributed system construction is to adopt a rigorous approach for system development, based on structuring principles. The CO-OPN/2 approach proposes a specification language, based on the object-oriented paradigm, which includes a fine description of true concurrent behavior. This hybrid approach (model and property-oriented) allows for a description of the concurrent aspects through the use of a high-level Petri nets formalismwhich includes data structures expressed with the algebrai...

Master's Thesis, University of Berne, 1998

IEEE Transactions on Software Engineering, 1994

The aim of a cooperative system is to coordinate and support group activities. Cooperative Systems Design Language (CSDL) is an experimental language designed to support the development of cooperative systems from specification to implementation. In CSDL, a system is defined as a collection of reusable entities implementing floor control disciplines and shared workspaces. CSDL tries to address the difficulties of integrating different aspects of cooperative systems: cooperation control, communication, and system modularization. This paper presents CSDL as a specification language. Basic units are coordinators that can be combined hierarchically. A coordinator is composed of a specification, a body, and a context. The specifcation defines the cooperation policy; the body controls the underlying communication channels; and the context defines coordinators' interaction in modular systems.

Proceedings of the international ACM SIGGROUP conference on Supporting group work - GROUP '99, 1999

Many object-oriented toolkits and frameworks for groupware development provide shared objects as a basic service. This relieves developers of a lot of problems originating from the field of distributed systems. However, there is little support on how to use shared objects to actually build collaborative applications. In this paper we propose an objectoriented model for applications using shared objects. The model is discussed with respect to object-oriented reusability aspects and its applicability is tested against CSCWspecific aspects like the provision of group-awareness and coupling control. Furthermore, concrete model examples derived from an example application are shown for illustration.

1998

Group support systems impose specific requirements on the underlying infrastructure regarding communication, configuration and data management. In this paper we concentrate on computer-supported cooperative work in the area of software development. We present the main principles of an experimental toolset for cooperative software development, outline specific demands on the underlying infrastructure for such kinds of applications, and describe an object-oriented infrastructure that offers appropriate solutions for the identified requirements. The infrastructure is implemented as a suite of object-oriented frameworks. In addition to general services for distributed object-oriented applications, we offer services like group communication, configuration and object sharing that are especially useful for implementing group support systems.

Lecture Notes in Computer Science, 1999

We introduce Oikos adtl, a speci cation language for distributed systems based on asynchronous communication via remote writings. The language is designed to support the composition of speci cations. It allows expressing the global properties of a system in terms of the local properties of the components and of coordination patterns. Oikos adtl is based on an asynchronous, distributed, temporal logic, which extends Unity to deal with components and events. We present the speci cation language and its semantics, introduce a number of compositionality theorems, and discuss some coordination patterns. A fragment of a standard case study is used to validate pragmatically the approach, with respect to expressiveness and work-ability.