a framework for aspect–oriented multiparty coordination

Separation of concerns has been presented as a promising tool to tackle the design of complex systems in which cross–cutting properties that do no fit into the scope of a class must be satisfied. In this paper, we show that interaction amongst a number of objects can also be described separately from functionality by means of the CAL language, and present a framework that provides the needed infrastructure. It is innovative because it supports open multiparty interactions

Aspect-oriented interaction in multi-organisational web-based systems

Separation of concerns has been presented as a promising tool to tackle the design of complex systems in which cross-cutting properties that do not fit into the scope of a class must be satisfied. Unfortunately, current proposals assume that objects interact by means of object-oriented method calls, which implies that they embed interactions with others into their functional code. This makes them dependent on this interaction model, and makes it difficult to reuse them in a context in which another interaction model is more suited, e.g., tuple spaces, multiparty meetings, ports, and so forth. In this paper, we show that functionality can be described separately from the interaction model used, which helps enhance reusability of functional code and coordination patterns. Our proposal is innovative in that it is the first that achieves a clear separation between functionality and interaction in an aspect-oriented manner. In order to show that it is feasible, we adapted the multiparty interaction model to the context of multiorganisational web-based systems and developed a class framework to build business objects whose performance rates comparably to handmade implementations; the development time, however, decreases significantly.Comisión Interministerial de Ciencia y Tecnología TIC2000-1106-C02-0

Multi-Party Coordination in the Context of MOWS

Separation of concerns has been presented as a promising tool to tackle the design of complex systems in which cross-cutting properties that do not fit into the scope of a class must be satisfied. In this paper, we show that interactions amongst a number of objects can also be described separately from functionality, which enhances reusability of functional code and interaction patterns. We present our proposal in the context of Multi-Qrganisational Web-Based Systems (MOWS) and also present a framework that provides the infrastructure needed to implement multiparty coordination as an independent aspect

An Aspect–Oriented Approach based on Multiparty Interactions to Specifying the Behaviour of a System

Isolating computation and coordination concerns into separate pure computation and pure coordination enhances modularity, understandability and reusability of parallel and/or distributed software. This can be achieved by moving interaction primitives, which are now commonly scattered in programs, into separate modules written in a language aimed at coordinating objects and expressing how information flows among them. The usual model for coordination is the client/server model, but it is not adequate when several objects need to collaborate simultaneously in order to solve a problem because natural multiparty interactions need to be decomposed into a set of low–level, binary interactions. In this paper, we introduce CAL, an IP–based language for the description of the coordination aspect of a system. We show that it can be successfully described in terms of simple multiparty interactions that can be animated and are also amenable to formal reasoning.Comisión Interministerial de Ciencia y Tecnología (CICYT) MENHIR TIC 97–0593–C05–0

A Multiparty Coordination Aspect Language

Coordination languages were motivated by an ever-increasing need for producing highly-reusable components, which can be partially achieved by implementing them in a way that is independent of the way they interact. Isolating interaction from computation, persistence and other concerns enhances modularity, thus promoting reusability and understandability. In this paper, we concentrate on a language aimed at describing the simultaneous coordination of a number of entities, which is a problem we are usually faced with when we have to programme bank transfers, purchases with debit cards, auctions, and so on. This language relies on the novel multiparty interaction model

Hybrid Session Verification through Endpoint API Generation

© Springer-Verlag Berlin Heidelberg 2016.This paper proposes a new hybrid session verification methodology for applying session types directly to mainstream languages, based on generating protocol-specific endpoint APIs from multiparty session types. The API generation promotes static type checking of the behavioural aspect of the source protocol by mapping the state space of an endpoint in the protocol to a family of channel types in the target language. This is supplemented by very light run-time checks in the generated API that enforce a linear usage discipline on instances of the channel types. The resulting hybrid verification guarantees the absence of protocol violation errors during the execution of the session. We implement our methodology for Java as an extension to the Scribble framework, and use it to specify and implement compliant clients and servers for real-world protocols such as HTTP and SMTP

Status of the Media Information Accessibility and the Civil Society in Tanzania as Weapons in the Fight Against Corruption

This paper describes the status of media reporting and Civil society in mobilizing against corruption in Tanzania

Multimedia Teleservices Modelled with the OSI Application Layer Structure

This paper looks into the communications capabilities that are required by distributed multimedia applications to achieve relation preserving information exchange. These capabilities are derived by analyzing the notion of information exchange and are embodied in communications functionalities. To emphasize the importance of the users' view, a top-down approach is applied. The (revised) OSI Application Layer Structure (OSI-ALS) is used to model the communications functionalities and to develop an architecture for composition of multimedia services with these functionalities. This work may therefore be considered an exercise to evaluate the suitability of OSI-ALS for composition of multimedia teleservices

CaSPiS: A Calculus of Sessions, Pipelines and Services

Service-oriented computing is calling for novel computational models and languages with well disciplined primitives for client-server interaction, structured orchestration and unexpected events handling. We present CaSPiS, a process calculus where the conceptual abstractions of sessioning and pipelining play a central role for modelling service-oriented systems. CaSPiS sessions are two-sided, uniquely named and can be nested. CaSPiS pipelines permit orchestrating the flow of data produced by different sessions. The calculus is also equipped with operators for handling (unexpected) termination of the partner’s side of a session. Several examples are presented to provide evidence of the flexibility of the chosen set of primitives. One key contribution is a fully abstract encoding of Misra et al.’s orchestration language Orc. Another main result shows that in CaSPiS it is possible to program a “graceful termination” of nested sessions, which guarantees that no session is forced to hang forever after the loss of its partner