Tasking Event-B: An Extension to Event-B for Generating Concurrent Code

The Event-B method is a formal approach for modelling systems in safety-, and business-critical, domains. Initially, system specification takes place at a high level of abstraction; detail is added in refinement steps as the development proceeds toward implementation. Our aim has been to develop a novel approach for generating code, for concurrent programs, from Event-B. We formulated the approach so that it integrates well with the existing Event-B methodology and tools. In this paper we introduce a tasking extension for Event-B, with Tasking and Shared Machines. We make use of refinement, decomposition, and the extension, to structure projects for code generation for multitasking implementations. During the modelling phase decomposition is performed; decomposition reduces modelling complexity and makes proof more tractable. The decomposed models are then extended with sufficient information to enable generation of code. A task body describes a task’s behaviour, mainly using imperative, programming-like constructs. Task priority and life-cycle (periodic, triggered, etc.) are also specified, but timing aspects are not modelled formally. We provide tool support in order to validate the practical aspects of the approach

Linking Event-B and Concurrent Object-Oriented Programs

AbstractThe Event-B method is a formal approach to modelling systems, using refinement. Initial specification is done at a high level of abstraction; detail is added in refinement steps as the development proceeds toward implementation. In software systems that use concurrent processing it is necessary to provide details of concurrent features before implementation. Our contribution is to show how Event-B models can be linked to concurrent, object-oriented implementations using an intermediate, object-oriented style specification notation. To validate our approach and gain further insight we automated the translation process with an Eclipse plug-in which produces an Event-B model and Java code. We call the new notation Object-oriented Concurrent-B (OC-B). The notation facilitates specification of the concurrent aspects of a development, and facilitates reasoning about concurrency issues in an abstract manner. We abstract away implementation details, such as locking, and provide the developer with a clear view of atomicity using labelled atomic clauses. We build on techniques introduced in UML-B to model object-oriented developments, introducing non-atomic operations and features for specifying implementation level details

An incremental process for the development of multi-agent systems in Event-B

A multi-agent system is a group of software or hardware agents that cooperate or compete to achieve individual or shared goals. A method for developing a multi-agent system must be capable of modelling the concepts that are central to multi-agent systems. These concepts are identified in a review of Agent Oriented Software Engineering methodologies. The rigorous development of complex systems using formal methods can reduce the number of design faults. Event-B is a formal method for modelling and reasoning about reactive and distributed systems. There is currently no method that guides the developer specifically in the modelling of agent-based concepts in Event-B. The use of formal methods is seen by some developers as inaccessible. This thesis presents an Incremental Development Process for the development of multi-agent systems in Event-B. Development following the Incremental Development Process begins with the construction of informal models, based on agent concepts. The informal models relate system goals using a set of relationships. The developer is provided with guidance to construct formal Event-B models based on the informal design. The concepts that are central to multi-agent systems are captured in the Event-B models through the translation from the goal models. The Event-B models are refined and decomposed into specifications of roles that will be performed by the agents of the system. Two case studies illustrate how the Incremental Development Process can be applied to multi-agent systems. An additional aid to the developer presented in this thesis is a set of modelling patterns that provide fault-tolerance for Event-B models of interacting agents.EThOS - Electronic Theses Online ServiceGBUnited Kingdo