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A formal notation and tool for the engineering of CORBA systems

CONCURRENCY-PRACTICE AND EXPERIENCE 2000年第14期12卷 1379-1403页

作者： Bastide, R Sy, O Palanque, P Univ Toulouse 1 LIHS FROGIS F-31042 Toulouse France

CORBA is a standard proposed by the object Management Group (OMG) in order to promote interoperability between distributed object systems. CORBA provides a programming-language neutral Interface Definition Language (IDL) that describes the syntactic aspects of services supported by remote objects, However, CORBA IDL does not provide any means to specify the behavior of objects in an abstract and formal way. In the current practice, behavioral specification is provided either in plain English, or directly in the programming language chosen for the implementation, We propose to extend the CORBA interface definition of distributed objects by a behavioral specification based on high level Petri nets. We detail at the syntactic and semantic level how this formalism supports the features of the CORBA object model. We present a realistic case study to demonstrate our approach, Our technique allows specifying in an abstract, concise and precise way the behavior of CORBA servers, including internal concurrency and synchronization. As the behavioral specification is fully executable, this approach also enables to prototype and test a distributed object system as soon as the behaviors of individual objects have been defined. The paper discusses several implementation issues of the tool that supports the edition of models and their interactive excution, The high level of formality of the chosen formalism allows for mathematical analysis of behavioral specifications. Copyright (C) 2000 John Wiley & Sons, Ltd.

关键词： formal methods distributed objected-oriented systems CORBA Petri nets behavioral specification

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The complexity of type analysis of object oriented programs 12th

The complexity of type analysis of object oriented programs

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12th european conference on object-oriented programming, ecoop 1998

作者： Gil, Joseph Yossi Itai, Alon IBM T. J. Watson Research Center P.O. Box 704 Yorktown HeightsNY10598 United States Department of Computer Science Technion—Israel Institute of Technology Haifa32000 Israel

ISBN: (纸本)3540647376

One of the price tags attached to the blessings that OO brings about is a drop in efficiency due to dynamic method dispatch. Much research effort is being spent on the problem of eliminating it, by applying static analysis to predict the set of dynamic types which a variable might store at any given program location. It was previously shown that the problem is NP-hard even if the program under analysis has no multi-level pointers. In this work, we show that under similar conditions, the problem is P-SPACE complete, provided that the program is not recursive. In the presence of recursion, the problem becomes EXP-TIME complete. (These two results also give an exponential time algorithm for a family of type analysis problems.) If multi-level pointers are allowed then the problem becomes EXP-SPACE complete without recursion and DEXP-TIME with it. Further, if the program under analysis may use recursive data structures then the problem becomes undedicable. Despite these, somewhat discouraging, results, we can prove that the type analysis becomes tractable, as evident from past practical experience, if the program under analysis obeys some few simple software engineering rules, while the analysis algorithm makes a corresponding simplifying assumption. © Springer-Verlag Berlin Heidelberg 1998.

关键词： Static analysis

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Multi-user object-oriented environments 13th

Multi-user object-oriented environments

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13th european conference on object-oriented programming, ecoop 1999

作者： Tomek, Ivan Diaz, Alicia Melster, Ronald Silva, António Rito Antunes, Miguel Cahill, Vinny Choukair, Zièd Fernandez, Alexandro Haahr, Mads Jul, Eric Ohnishi, Atsushi Rodrigues, Luís Schmidt, Erich R. pu, Cristian Wieczerzycki, Waldemar Zimmerman, Daniel M. Acadia University Canada Lifia - UNLP La Plata Argentina GMD FIRST Berlin Germany INESC Technical University of Lisbon Portugal Trinity College Dublin Ireland ENST Bretagne France University of Copenhagen Denmark Ritsumeikan University Japan University of Lisbon Portugal California Institute of Technology United States Posnan University of Economics Poland

ISBN: (纸本)354066954X

Network-based computer environments emulating selected aspects of the physical world and allowing interaction among their human users first appeared in the late 1970s. These environments implemented a networked version of a role-playing fantasy game known as Dungeons and Dragons, hence their acronym MUD (Multi-user Dungeons). When it became obvious that many MUD users use the environment mainly to meet virtually with other users rather than to play games, new forms of MUDs and other types of emulated universes were developed and the term Virtual Environment (VE) was introduced to refer to all of them. Since their inception, VEs evolved in several interesting directions, including environments with new types of user interfaces, for example emulating visual aspects of physical reality via VRML and other means [8], and object-oriented environments known as MOOs (MUD object-oriented) allowing their users to extend the environment and communicate with it via a programming language [22]. As virtual environments became better known and more sophisticated, their user populations reached hundreds of thousands. At present, VEs are used for recreation, education [16], particularly distance education, and in work, particularly for collaboration among physically separated team members [6, 26, 36, 15, 45]. There is also a large and growing body of research on existing and potential VE uses, and several meetings similar to this workshop are held every year to address both the usage and the technical aspects of VEs. Collaborative work is, of course, an area of major interest to software developers and we will thus address this issue further.

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Transparent object proxies for javascript

Transparent object proxies for javascript

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Software Engineering-Konferenz, SE 2016 - Software Engineering conference, SE 2016

作者： Keil, Matthias Farooq, Omer Guria, Sankha Narayan Schlegel, Andreas Geffken, Manuel Thiemann, Peter University of Freiburg Freiburg Germany Indian Institute of Technology Jodhpur Jodhpur India

ISBN: (纸本)9783885796466

This work appeared in the conference proceedings of the european conference on object-oriented programming, ecoop 2015. One important question in the design of a proxy API is whether a proxy object should inherit the identity of its target. Apparently proxies should have their own identity for security-related applications whereas other applications, in particular contract systems, require transparent proxies that compare equal to their target objects. In this work we examine the issue with transparency in various use cases for proxies, discuss different approaches to obtain transparency, and propose two designs that require modest modifications in the JavaScript engine and cannot be bypassed by the programmer. The JavaScript Proxy API embodies a design decision that reveals the presence of proxies in some important use cases. This decision concerns object equality. Proxies are opaque, which means that each proxy has its own identity, different from all other (proxy or nonproxy) objects. Given opaque proxies, an equality test can be used to distinguish a proxy from its target as demonstrated in the following example: 1 var target = { /' some object '/ };2 var handler = { /' empty handler '/ };3 var proxy = new Proxy (target, handler);4 proxy===target;// evaluates to false Even though target and proxy behave identically, they are not considered equal. Thus, in a program that uses object equality, the introduction of a proxy along one execution path may change the meaning of the program without even invoking an operation on the proxy (which may behave differently from the same operation on the target). Equality for opaque proxies works well under the assumption that proxies and their targets are never part of the same execution environment. But the assumption that proxies never share their execution environment with their targets is not always appropriate. One prominent use case is the implementation of a contract system. Two examples for such systems are the contract

关键词： Transparency

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Reducing the cost of certification:: A new approach OTCD

Reducing the cost of certification:: A new approach OTCD

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conference on DAta Systems in Aerospace

作者： Morère, P Aonix F-92247 Malakoff France

ISBN: (纸本)9290926694

Working for a wide kind of industrials, we have note that more and more industrial coming from Avionics, Ground Transportation are moving to full object oriented development. On another hand, more and more applications become subject to "certification": which more and more stringent constraints. Moreover such certifiable applications have an increasing complexity, this is due principally to the fact that now ground system are subject to formal certification. Starting from this state of art Aonix has tried to reduce the cost of development of certifiable application :first by increasing the traceability between analysis, design and programming, second by reducing the complexity of the code and third by reducing the cost of evolution regarding the test process. These brand new methodology, named OTCD Optimised Technique for Certification of Dispatching, was developed for the implementation of a protocol of communication. And we are currently formalising it under the name of Certifiable Pattern Design.

关键词： UML object oriented ACD certification dispatching OTCD

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Space- and time-efficient implementation of the Java object model 16th

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16th european conference on object-oriented programming, ecoop 2002

作者： Bacon, David F. Fink, Stephen J. Grove, David IBM T.J. Watson Research Center P.O. Box 704 Yorktown HeightsNY10598 United States

ISBN: (纸本)3540437592

While many object-oriented languages impose space overhead of only one word per object to support features like virtual method dispatch, Java’s richer functionality has led to implementations that require two or three header words per object. This space overhead increases memory usage and attendant garbage collection costs, reduces cache locality, and constrains programmers who might naturally solve a problem by using large numbers of small objects. In this paper, we show that with careful engineering, a high-performance virtual machine can instantiate most Java objects with only a single-word object header. The single header word provides fast access to the virtual method table, allowing for quick method invocation. The implementation represents other per-object data (lock state, hash code, and garbage collection flags) using heuristic compression techniques. The heuristic retains two-word headers, containing thin lock state, only for objects that have synchronized methods. We describe the implementation of various object models in the IBM Jikes Research Virtual Machine, by introducing a pluggable object model abstraction into the virtual machine implementation. We compare an object model with a two-word header with three different object models with single-word headers. Experimental results show that the object header compression techniques give a mean space savings of 7%, with savings of up to 21%. Compared to the two-word headers, the compressed space-encodings result in application speedups ranging from −1.5% to +2.2%. Performance on synthetic micro-benchmarks ranges from +23% due to benefits from reduced object size, to −12% on a stress test of virtual method invocation. © Springer-Verlag Berlin Heidelberg 2002.

关键词： Locks (fasteners)

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object-oriented legacy system trace-based logic testing

Object-oriented legacy system trace-based logic testing

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10th european conference on Software Maintenance and Reengineering

作者： Ducasse, Stephane Girba, Tudor Wuyts, Roel Univ Savoie LISTIC Chambery France Univ Bern SCG Bern Switzerland Univ Libre Bruxelles Decomp Brussels Belgium

ISBN: (纸本)0769525369

When reengineering legacy systems, it is crucial to assess if the legacy behavior has been preserved or how it changed due to the reengineering effort. Ideally if a legacy system is covered by tests, running the tests on the new version can identify potential differences or discrepancies. However, writing tests for an unknown and large system is difficult due to the lack of internal knowledge. It is especially difficult to bring the system to an appropriate state. Our solution is based on the acknowledgment that one of the few trustable piece of information available when approaching a legacy system is the running system itself Our approach reifies the execution traces and uses logic programming to express tests on them. Thereby it eliminates the need to programatically bring the system in a particular state, and handles the test-writer a high-level abstraction mechanism to query the trace. The resulting system, called TESTLOG, was used on several real-world case studies to validate our claims.

关键词： legacy systems testing dynamic information logic programming

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On the Problem of Development of Methods and Algorithms Based on the object-oriented Logic programming for Intelligent Video Monitoring of Laboratory Rats 4

On the Problem of Development of Methods and Algorithms Base...

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4th International conference on Information Technology and Nanotechnology - Session: Image Processing and Earth Remote Sensing, IPERS-ITNT 2018

作者： Morozov, A.A. Sushkova, O.S. Kotel'Nikov Institute of Radio Engineering and Electronics of RAS Mokhovaya str. 11-7 Moscow125009 Russia

The problem of the video monitoring the laboratory rats by the means of the object-oriented logic programming is considered. The main task of the video monitoring is the analysis of the behavior of the animals in cognitive testing. An essential feature of the video records is in that the experiments are conducted in the same cage where the animal lives, that is, the background of the cage is sawdust. The color of the animals is about the same as the color of the sawdust;thus the detection of the animals is not a simple task. An additional difficulty is in that the videos were recorded simultaneously with electroencephalograms (EEG) in the animals;thus the head of the rat is connected with EEG cable that moves and causes false detections of recognition algorithms. In the paper, development of low-level algorithms for video analysis as well as logical methods for the analysis of the animal behavior is discussed. The methods and algorithms are implemented in the Actor Prolog object-oriented logic language. © 2018 CEUR-WS. All rights reserved.

关键词： Computer circuits

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Java UI : Eeffects for controlling UI object access

Java UI : Eeffects for controlling UI object access

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27th european conference on object-oriented programming, ecoop 2013

作者： Gordon, Colin S. Dietl, Werner Ernst, Michael D. Grossman, Dan University of Washington United States

ISBN: (纸本)9783642390371

Most graphical user interface (GUI) libraries forbid accessing UI elements from threads other than the UI event loop thread. Violating this requirement leads to a program crash or an inconsistent UI. Unfortunately, such errors are all too common in GUI programs. We present a polymorphic type and effect system that prevents non-UI threads from accessing UI objects or invoking UI-thread-only methods. The type system still permits non-UI threads to hold and pass references to UI objects. We implemented this type system for Java and annotated 8 Java programs (over 140KLOC) for the type system, including several of the most popular Eclipse plugins. We confirmed bugs found by unsound prior work, found an additional bug and code smells, and demonstrated that the annotation burden is low. We also describe code patterns our effect system handles less gracefully or not at all, which we believe offers lessons for those applying other effect systems to existing code. © 2013 Springer-Verlag Berlin Heidelberg.

关键词： Graphical user interfaces

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Multiparadigm programming in object-oriented languages: current research report on the workshop MPOOL'07 at ecoop 2007 07

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Proceedings of the 2007 conference on object-oriented technology

作者： Kei Davis Jörg Striegnitz Los Alamos National Laboratory Los Alamos NM University of Applied Sciences Regensburg Regensburg Germany

ISBN: (纸本)9783540781943

While OO has become ubiquitously employed for design, implementation, and even conceptualization, many practitioners recognize the concomitant need for other programming paradigms according to problem domain. Nevertheless, the choice of a programming paradigm is strongly influenced by the supporting programming language facilities. In turn, choice of programming language is usually highly constrained by practical considerations. We seek answers to the question of how to address the need for other programming paradigms, or even domain specific languages, in the general context of OO *** is clear that this field is yet nascent: novel, disparate approaches and techniques are still being discovered or invented, and this very novelty adds a significant element of intellectual entertainment. This article describes the cross section of research efforts reported at the workshop on Multiparadigm programming in object-oriented Languages held at the 2007 european conference on object-oriented programming.

关键词： object-oriented programming multiparadigm

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