Sharif Digital Repository

Rebeca is an actor-based language for modeling concurrent and distributed systems as a set of reactive objects which communicate via asynchronous message passing. Rebeca is extended to support synchronous communication, and at the same time components are introduced to encapsulate the tightly coupled reactive objects which may communicate by synchronous messages. This provide us a language for modeling globally asynchronous and locally synchronous systems. Components interact only by asynchronous messages. This feature and also the eventdriven nature of the computation are exploited to introduce a modular verification approach in order to overcome the state explosion problem in model... 

Actor-based modeling, with encapsulated active objects which communicate asynchronously, is generally recognized to be well-suited for representing concurrent and distributed systems. In this paper we discuss the actor-based language Rebeca which is based on a formal operational interpretation of the actor model. Its Java-like syntax and object-based style of modeling makes it easy to use for software engineers, and its independent objects as units of concurrency leads to natural abstraction techniques necessary for model checking. We present a front-end tool for translating Rebeca to the languages of existing model checkers in order to model check Rebeca models. Automated modular... 

In the IEEE 802.1D standard for the Media Access Control layer (MAC layer) bridges, there is an STP (Spanning Tree Protocol) definition, based on the algorithm that was proposed by Radia Perlman. In this paper, we give a formal proof for correctness of the STP algorithm by showing that finally a single node is selected as the root of the tree and the loops are eliminated correctly. We use formal inductive reasoning to establish these requirements. In order to ensure that the bridges behave correctly regardless of the topology of the surrounding bridges and LANs, the Rebeca, modular verification techniques are applied. These techniques are shown to be efficiently applicable in model checking... 

In this paper, we propose extended Rebeca as a tool-supported actor-based language for modeling and verifying concurrent and distributed systems. We enrich Rebeca with a formal concept of components which integrates the message-driven computational model of actor-based languages with synchronous message passing. Components are used to encapsulate a set of internal active objects which react asynchronously to messages by means of methods and which additionally interact via a synchronous message passing mechanism. Components themselves interact only via asynchronous and anonymous messages. We present our compositional verification approach and abstraction techniques, and the theory...