Object-Oriented Modules

Formal Verification of Object-Oriented Graph Grammars Specifications

Attractive round-up of a complex area: Design and Validation of Computer Protocolsby Gerard J Holzman. Published by Prentice Hall, 1992, £22.95, 500 pp

Concurrent object-oriented programming systems require support for concurrency control, to enforce consistent commitment of changes and to support program-initiated rollback after application-specific failures. We have explored three different concurrency control models atomic blocks, serializable transactions, and commit-serializable transactions - as part of the MELD programming language. We present our designs, discuss certain programming problems and implementation issues, and compare our work on MELD to other concurrent object-based systems.

A concurrent object-oriented programming language system for highly parallel data-driven computers and its applications

Narrowing and heuristic search for symbolic reachability analysis of concurrent object-oriented systems

Visual Programming of Concurrent Object-Oriented Systems

Reflection or metalevel architecture has received attention in recent years, since this approach provides functional extension and dynamic adaptation of computer systems. In this paper, we propose a technique to introduce reflection into a kind of algebraic system called rewriting logic. Since rewriting logic can model concurrent object-oriented systems, our technique enables modeling of reflective object-oriented systems including metaobjects and metaobject protocols. A framework for developing denotational semantics is given based on a category-theoretic model. We present some problems for finishing our semantics which remain unsolved.KeywordsInference RuleExecution ModelDenotational SemanticSemantic DomainAlgebraic SemanticThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Capturing the evolution of logical objects and structures in a software project is crucial to the development of a high-quality software. This research demonstration presents an object-oriented approach to managing the evolution of system objects at the logical level. Keys to our approach are its extensible, logical, and object-oriented system model and structure versioning framework in which types of logical objects and structures in a software system are extended from a small set of the system model's basic entities, allowing them to be versioned in a fine-grained manner and independent of the physical file structure. Changes to all logical objects and structures are captured and related to each other in a tightly connected and cohesive manner via the Molhado product versioning software configuration management (SCM) infrastructure. We also demonstrate our object-oriented SCM approach by applying it in different development paradigms such as UML-based object-oriented software development, architecture-based software development, and Web application development.

A behavior preserving relation between Petri-net systems is introduced in this paper, based on the observability of both places and transitions, which is important in modeling the dynamic behavior of concurrent object-oriented systems with Petri nets. Each group of closely related attributes of a concurrent object is modeled by the state of a collection of observable places, and each of its methods by a group of observable transitions. The grouping distinguishes the definition in this paper from others, which makes it easy to work together with the static object models, to reuse the models and to dispel the interference among groups, thus relieving the problem of inheritance anomaly by the possibility of dividing the synchronization code into independent parts. For a formal definition of this behavior subtyping relation, Elementary Net systems, with both S-elements and T-elements labeled, are used. Then it is extended informally to the state based coloured Petri net systems. Finally, the background of the definitions and the future work are presented.

Ninflet is a Java-based global computing system that builds on our experiences with the Ninf system which facilitated RPC-based computing of numerical tasks in a wide-area network. The goal of Ninflet is to become a new generation of concurrent object-oriented systems which harness abundant idle computing powers, and also seamlessly integrate global as well as local network parallel computing. Ninflet is designed to make use of Java features to implement important features in global computing, such as resource allocation, inter-Ninflet communication, security, checkpointing, object migration, and easy server management via HTTP. © 1998 John Wiley & Sons, Ltd.

The author describes an approach to the representation, specification and implementation of multi-agent real-time systems. The approach is based on the notion of concurrent object-oriented systems where processes are represented as objects. This is a highly suitable base for extension to distributed AI and multi-agent application platforms. In his approach, the behaviour of an agent (its safety, properties and time requirements) is declaratively stated as a set of temporal constraints among events which provides great advantages in writing multi-agent systems and manipulating them while preserving correctness. The temporal constraints have a procedural interpretation that allows them to be executed, also concurrently. In this way the specification of an agent behavior is directly executed thus eliminating the need to verify that the implementation satisfies its specification. The approach also proves a framework in which algorithms for a variety of concurrent programming paradigms may be expressed, compared and manipulated, and can be used as the basis for a development methodology for multi-agent real-time systems.

Object-oriented systems have provided a new methodology for decomposing problems. They have also brought out the issue of the specification of concurrency in a more structured manner. The paper shows how the Parallel Objects (PO) model addresses the problem of supporting concurrency. PO is a parallel object-oriented model. Any entity/object is capable of independent execution and in addition several concurrent activities can exist within the same object. In fact, as a feature distinguished from other concurrent object systems, PO does not strive to obtain intra-object sequentialization. In PO, the specification of concurrency can take advantage of a layered approach. Depending on user skill, the system requires more or less deep insight of PO to specify concurrency. A novice user can derive the specification of object concurrency from the PO environment. This approach stresses the reuse principle typical of object systems, i.e., inheritance. The PO environment makes it possible for skilled users to investigate complex concurrency policies and their performances for the same application.

Exception handling in a complex concurrent and distributed system (e.g. one involving cooperating rather than just competing activities) is often a necessary, but a very difficult, task. No widely accepted models or approaches exist in this area. The object-oriented paradigm, for all its structuring benefits, and real-time requirements each add further difficulties to the design and implementation of exception handling in such systems. In this paper, we develop a general structuring framework based on the coordinated atomic (CA) action concept for handling exceptions in an object-oriented distributed system, in which exceptions in both the value and the time domain are taken into account. In particular, we attempt to attack several difficult problems related to real-time system design and error recovery, including action-level timing constraints, time-triggered CA actions, and time-dependent exception handling. The proposed framework is then demonstrated and assessed using an industrial real-time application-the Production Cell III case study.

We present a novel framework for symbolically exploring very large or infinite state spaces of concurrent reactive object-oriented systems. In our framework we apply A* directed search algorithms for performing an efficient heuristic state space exploration towards user-defined search goals. The used heuristics exploit semantical knowledge about a system when searching for specific properties. The knowledge is extracted prior to the search process by computing abstractions of the considered systems. Based on an abstraction and a search goal we generate a heuristic function which can be used during state space exploration of the concrete system. The heuristics can be generated fully automatically and with different precision. Our approach to state space exploration has been implemented in a tool set called HORSE. The tool set can work in combination with an industrial UML case tool, and we show the applicability of our approach by applying the tool set to several sample models.Keywordsheuristic searchsymbolic executionabstractionsUML

article Reflective computation in object-oriented concurrent systems and its applications Share on Authors: T. Watanabe Department of Information Science, Tokyo Institute of Technology, 2-12-1, Ook,ayama, Meguro-ku, Tokyo, Japan Department of Information Science, Tokyo Institute of Technology, 2-12-1, Ook,ayama, Meguro-ku, Tokyo, JapanView Profile , A. Yonezawa Department of Information Science, Tokyo Institute of Technology, 2-12-1, Ook,ayama, Meguro-ku, Tokyo, Japan Department of Information Science, Tokyo Institute of Technology, 2-12-1, Ook,ayama, Meguro-ku, Tokyo, JapanView Profile Authors Info & Claims ACM SIGSOFT Software Engineering NotesVolume 14Issue 3May 1989 pp 56–58https://doi.org/10.1145/75200.75209Online:01 April 1989Publication History 2citation232DownloadsMetricsTotal Citations2Total Downloads232Last 12 Months3Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access