Parallel Object-oriented Language Research Articles

РАЗРАБОТКА СРЕДСТВ АГЕНТНОГО ЛОГИЧЕСКОГО ПРОГРАММИРОВАНИЯ ДЛЯ МНОГОКАНАЛЬНОГО ИНТЕЛЛЕКТУАЛЬНОГО ВИДЕОНАБЛЮДЕНИЯ

Experimental means developed in the Actor Prolog parallel object-oriented logic language for implementation of heterogeneous multichannel intelligent visual surveillance systems are considered. These means are examined by the instance of a logic program for permanent monitoring of people's body parts temperature in the area of visual surveillance. The logic program implements a fusion of heterogeneous data acquired by two devices: (1) 3D coordinates of human body are measured using a time-of-flight (ToF) camera; (2) 3D coordinates of human body skeleton are computed on the base of 3D coordinates of the body; (3) a thermal video is acquired using a thermal imaging camera. Special built-in classes are developed in the Actor Prolog language for the acquisition and analysis of 3D and 2D video data: the Kinect and KinectBuffer classes implement interaction between the logic program and the ToF camera of the Kinect-2 device; the BufferedScene class implements storing and transferring 3D images; the Canvas3D class implements 3D graphics based on the Java3D open source library. In the considered example, the thermal video is projected to the 3D surface of the human body; then the temperature of the human body is projected to the vertices and edges of the skeleton. A special logical agent (i.e., the logic program written in Actor Prolog) implements these operations in real-time and transfers the data to another logical agent. The latter agent implements a time average of the temperature of the human skeletons and displays colored 3D images of the skeletons; the average temperature of the vertices and edges of the skeletons is depicted by colors. A method of remote predicate calls is used for the interaction of the logical agents; this method was developed and implemented in Actor Prolog to support the agent logic programming paradigm. The logic programming means under consideration are developed for the purpose of the implementation of logical analysis of video scene semantics in the intelligent visual surveillance systems. © 2018 Radioelektronika, Nanosistemy, Informacionnye Tehnologii. All rights reserved.

Patterns for Automatic Generation of Soft Real-time System Models

Worst-case assumptions about the timing of systems are often too conservative when analyzing distributed soft real-time systems as they lead to over-dimensioned and expensive products. For these systems, a certain percentage of deadline misses is often affordable. Instead of a binary answer regarding the schedulability of such a system, a more interesting metric is the degree to which the system meets the timing requirements. For this, an appropriate model that realistically expresses the behavior of a soft real-time system when deployed on a multiprocessor platform should be built and analyzed. In this article, we present such a modeling approach based on the formal modeling language POOSL (parallel object-oriented specification language). Moreover, to alleviate the process of modeling, we present a pattern-based description language that allows an application, together with the multiprocessor platform and the deployment to be described in a concise way. Such a pattern-based description can be translated automatically into an executable POOSL model through which performance properties can be analyzed based on simulations. The suitability of our approach is demonstrated by exploring the design space of a distributed in-car radio navigation system.

SC-EXPRESSIONS IN OBJECT-ORIENTED LANGUAGES

In this paper, SC-expressions are developed, based on automata theory, for specifying synchronization constraints in parallel object-oriented languages. The predecessor of SC-expressions, the synchronization expressions, was introduced in the ParC parallel programming language in the early nineties [19]. However, ParC is not an object-oriented language and also a number of basic features of synchronization expressions are inadequate for object-oriented languages. SC-expressions are developed for object-oriented environment. They are different from synchronization expressions in basic ideas and assumptions. Here we describe the basic ideas of SC-expressions and their applications in object-oriented languages. We also study the problem of inheritance of the SC-expressions.

Performance modelling of a network processor using POOSL

The increasing complexity of innovative real-time hardware/software systems forced industry to consider system-level design methods. Before actually implementing a system with hardware and software components, system-level design methods enable analysing the performance of different design alternatives that realise the required functionality. In order to develop performance models early in the design process, the parallel object-oriented specification language (POOSL) can be used. POOSL is an expressive modelling language for analysing complex real-time distributed hardware/software systems. Being equipped with a formal semantics, POOSL ensures unambiguous execution of models and proper application of performance analysis techniques. This paper discusses the use of POOSL for analysing the performance of a network processor. A network processor consists of components that perform their behaviour in a synchronously concurrent way, whereas POOSL is based on an asynchronous modelling paradigm. In this paper, we illustrate that constructing abstract models of synchronous systems for the purpose of performance analysis may benefit from an asynchronous modelling approach.

A Maude specification of an object-oriented model for telecommunication networks

This paper presents an object-oriented model for broadband telecommunication networks, which can be used both for network management and for network planning purposes. The object-oriented model has been developed using the parallel object-oriented specification language Maude, which allows us to define not only structural aspects of the model but also procedural aspects. The reflective properties of rewriting logic are applied to control the rewriting process, using a strategy language that can be specified internally to the logic. Several modeling approaches are compared, emphasizing the definition of the object relationships and the benefits obtained from using reflection as opposed to the extra effort required to control the process at the object level itself.

MODELS AND TRENDS IN PARALLEL PROGRAMMING

This paper introduces and discusses programming models for parallel processing and recent trends in the area of parallel programming. The paper discusses different parallel programming languages and tools that reflect various parallel computation models. These language differ in expressiveness, portability and performance. Software design and implementation largely varies by using different languages that make the programmer task easy or complex. We describe here the design goals and the main issues of parallel programming models and languages belonging to the following categories: shared-space based languages, message-based languages, parallel toolkits, data-parallel languages, parallel declarative languages, parallel object-oriented languages, and parallel composition-based languages. Tools and languages such as HPF, Linda, Java, OpenMP, PVM, MPI, Parallel C+ +, Sisal, Orca, Mentat, SkieCL, BSP and others are described in some detail. Their main features for design and implementation of high performance applications are discussed. Finally, we outline directions of research and development in the parallel programming area with a special attention to novel approaches based on high-level programming structures that make transparent to the users the architectural details of parallel computing machines.

Design, Implementation and Evaluation of a Parallel Object-Oriented Language A-NETL

A-NETL is a parallel object-oriented language intended to be used for managing small to massive parallelism with medium grain size. Its design goals are to treat data parallel operations at the same cost as programming languages of the SIMD type, to support various styles of message passing among objects, and to provide several synchronization facilities for realizing autonomous control of objects. Starting with these design principles, we present the syntax and semantics of the language features, and its implementation issues, such as the reduction of message communication cost, efficient implementation of statically and dynamically created massive objects, the realization of synchronization schemes, and the object-to-node allocation scheme to minimize communication cost. We present performance results from the language's implementation on an A-NETL oriented multicomputer, on the AP1000 using the AP1000's message passing library and on a cluster of workstations using the PVM library.

Event-based debugging system for a parallel object-oriented language A-NETL

Debugging of parallel programs is generally very difficult to undertake since the execution of programs is nondeterministic and nonrepeatable. Considering a parallel object-oriented language, this paper proposes a method of preserving the repeatability of the order of execution in a replay by defining a logic time in terms of events in the message communication system and state transitions, and by representing the execution history of events. A debugger that mainly uses a two-dimensional (2-D) representation and replay debugging has been designed based on the proposed method. A high-performance system has been constructed based on the design. The debugger functions are distributed between a host workstation and multicomputer nodes, and between local OS on nodes and in firmware so that a high-performance system has been realized. The experiments show that the method is successful for practical applications; the time and space overhead of event recording is 0.04 ms (mean value) and 35 B per event, respectively; the display of 16 objects for one logical time is 0.94 s; and the overhead for a breakpoint is 3.1 ms per point. © 1998 Scripta Technica, Syst Comp Jpn, 28(11): 53–63, 1997

Parallel object-oriented programming for parallel simulations

This paper presents the development of a parallel object-oriented language which is an extension of C++, called C++//. C++// offers reusability, flexibility and extensibility in concurrent programming through a set of language primitives (indeed a Meta-Object Protocol), independent of any parallel paradigm. It permits us to build libraries of nearly all concurrent programming models. One of them, presented here, is an MIMD model based on data-flow synchronizations (wait-by-necessity). C++// runtime main concern is versatility so its implementation is in fact an interface to any low-level runtime support. C++// is used to define and implement prosit, an object-oriented framework for distributed discrete event simulation. In the paper, we highlight the features which are crucial for the development of this generic simulation environment, mainly expressiveness, end-user adaptation and a strong reuse potential. All those important features are directly provided by the use of C++//. prosit and C++// are part of the Sloop project developments.

Visualization of RNA secondary structures using highly parallel computers.

Results of RNA secondary structure prediction algorithm are usually given as a set of hydrogen bonds between bases. However, we cannot know the precise structure of an RNA molecule by only knowing which bases form hydrogen bonds. One way to understand the structure of an RNA molecule is to visualize it using a planar graph so that we can easily know the geometric relations among the substructures such as stacking regions and loops. To do this, we consider bases to be particles on a plane and introduce a repulsive force and an attractive force among these particles and determine their positions according to these forces. A naive algorithm requires O(N2) time but we can reduce it to O(NlogN) with an approximation algorithm which is often used in the area of N-body simulation. Our program is written in parallel object-oriented language 'Schematic' which is recently developed. Efficiency of our implementation on a parallel computer and results of visualization of secondary structures are presented using cadang-cadang coconut viroid as an example.

A Maude specification of an object-oriented database model for telecommunication networks

This paper presents an object-oriented database model for broadband telecommunication networks, which can be used both for network management and for network planning purposes. The object-oriented data model has been developed using the parallel object-oriented specification language Maude [8,11], which allows us to define not only structural aspects of the database, but also procedural aspects. Several modeling approaches are compared, emphasizing the definition of the object relationships and some of the procedural aspects of the model.

Objects in the π-Calculus

Two semantics for a parallel object-oriented programming language are presented. One is a two-level transitional semantics in which the global behaviour of a system is derived directly from the possible actions of its constituent objects. The other is by translation into the π-calculus. A close correspondence between the semantics is established.

CoSIDE and parallel object-oriented languages

article Free Access Share on CoSIDE and parallel object-oriented languages Authors: R. Winder View Profile , G. Roberts View Profile , M. Wei View Profile Authors Info & Claims ACM SIGPLAN OOPS MessengerVolume 4Issue 2April 1993 pp 211–213https://doi.org/10.1145/157710.157757Online:01 December 1992Publication History 0citation150DownloadsMetricsTotal Citations0Total Downloads150Last 12 Months0Last 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 SiteeReaderPDF

A layered semantics for a parallel object-oriented language

Abstract We develop a denotational semantics for POOL, a parallel object-oriented programming language. The main contribution of this semantics is an accurate mathematical model of the most important concept in object-oriented programming: the object. This is achieved by structuring the semantics in layers working at three different levels: for statements, objects and programs. For each of these levels we define a specialized mathematical domain of processes, which we use to assign a meaning to each language construct. This is done in the mathematical framework of complete metric spaces. We also define operators that translate between these domains. At the program level we give a precise definition of the observable input/output behaviour of a particular program, which could be used at a later stage to decide the issue of full abstractness. We illustrate our semantic techniques by first applying them to a toy language similar to CSP.

POOL: design and experience

The first language of the POOL family (Parallel Object-Oriented Language) was designed in 1984. Since then, a considerable amount of research on this subject has been performed. The aim of these activities was to develop a programming language that effectively supports the construction of large, complex applications that could be run on a multiprocessor without shared memory. At this moment, it can be said that a significant progress has been made in solving this formidable problem.

Ellie language definition report

This report defines the parallel object-oriented language Ellie in details by means of informal definitions and examples. The syntax of Ellie is defined by a grammar. Ellie has been designed as a part of my Ph.D. thesis.The goals of Ellie are to achieve machine independent parallel programming and great language flexibility. Machine independent parallel programming is achieved by allowing the programmer to have a huge number of small processes for a virtual distributed memory parallel computer. If an actual distributed parallel computer can not execute the huge number of processes efficiently then a compiler can combine small processes hereby reducing the number of processes.Great language flexibility is achieved by allowing definitions of new types and control structures and by using a non-strict type system. Ellie is meant as an all-purpose programming language that has the flexibility of languages like Smalltalk and Lisp without losing efficiency in numerical calculations etc.

A parallel object-oriented language with inheritance and subtyping

This paper shows that inheritance and subtyping can be introduced advantageously into a parallel object-oriented language, POOL-I. These concepts are clearly distinguished, because they deal with different aspects of programming. In this way several problems traditionally adhering to inheritance can be solved. The language POOL-I is a parallel object-oriented language with a strong typing scheme which includes genericity and dynamic binding. A novel and particularly powerful mechanism offers the possibility to manipulate and analyse types dynamically.

Designing a parallel object-oriented compiler target language (TOOL)

As the level of interface between software and hardware is continuously shifting, the requirement for standard points of reference becomes increasingly important. TOOL is an intermediate-level parallel language aspiring to meet this requirement by establishing a common target for compilation of a wide range of high-level object-oriented languages and also, of process-oriented languages. TOOL exhibits the major object-oriented features, including data abstraction, multiple inheritance and dynamic binding. In addition, parallelism, although inherent in the computational model, is further supported by providing: (a) asynchronous message passing and synchronization mechanisms, (b) support for “autonomous” objects (ie. permanently active), and (c) special facilities for object allocation and migration.

Semantic Correctness for a Parallel Object-Oriented Language

Different semantic models are studied for a language called POOL: parallel object-oriented language. It is a simplified version of POOL-T, a language that is actually used to write programs for a parallel machine. The most important aspect of this language is that it describes a system as a collection of communicating objects that all have internal activities which are executed in parallel. For POOL, operational and denotational semantics have been developed previously. The former aims at the intuitive operational meaning of the language, whereas the main characteristic of the latter is compositionality. In this paper, the author relates both models, which are quite different, and proves the semantic correctness of the denotational semantics with respect to the operational semantics. These semantic investigations take place in the mathematical framework of complete metric spaces. For the operational semantics a simple space of functions from states to compact sets of streams (which are sequences of states) is used; for the denotational semantics, a domain of processes is used, which is the solution of a reflexive domain equation over a category of complete metric spaces. The main mathematical tool we use is Banach’s theorem, which states that contractions on complete metric spaces have unique fixed points. Both the operational and the denotational semantics are reformulated and are presented, as well as many operators on the semantic domains, as the fixed point of a suitably defined contraction. In this way, a formal equivalence between both models is established. For this purpose, an intermediate domain, which is first compared to the operational model by means of an abstraction operator, is introduced. This function takes processes, which are treelike structures, as arguments and yields sets of streams as results. Next, it is shown that both intermediate and the denotational model are fixed points of the same contraction, from which their equality follows. From both facts, the main result of this study follows: The operational meaning of a POOL program is equal to the denotational meaning to which the abstraction operator is applied. In this manner, the correctness of the denotational semantics with respect to the operational semantics is established.

Issues in the design of a parallel object-oriented language

This paper discusses the considerations that have played a role in the design of the language POOL2. This language integrates the structuring techniques of object-oriented programming with mechanis...