An efficient and flexible C++ library for concurrent programming

A major problem for the integration of concurrency in object-oriented languages is the so-called inheritance anomaly, i.e. the conflicts between inheritance and concurrency that often cause the need to redefine inherited methods in order to maintain the integrity of objects. Several solutions have been proposed for resolving these conflicts. However, some of them are incomplete, and do not solve all types of inheritance anomaly; others make the definition of classes complex and/or their implementation inefficient. This paper describes a C⁺⁺ library for concurrent programming that provides a comprehensive framework particularly suitable for coarse-grained distributed applications. This library copes with the inheritance anomaly problem, presenting a solution that minimizes the redefinition of inherited methods without increasing the complexity to write them. This solution is based on the use of a special set of methods, called interface methods, composed of a body and two sets of synchronization constraints. These two sets of synchronization constraints are respectively used to enable the execution of their method body and to disable the methods that cannot be executed after their method. © 1998 John Wiley & Sons, Ltd.     

Concurrent programming in VISO

Concurrent programming is more difficult to use and understand than sequential programming. In order to simplify this type of programming a number of approaches have been developed such as visual programming. Visual Occam (VISO) is a visual programming language for concurrent programming. It has a graphical syntax based on the language Occam and its semantics is represented both in petri net and process calculus. This paper presents a modular visual approach to write concurrent programs using the VISO language. Concurrent programs in VISO are specified graphically at different levels of abstraction. This paper describes this modular visual approach by constructing two examples in VISO. The first example is a simple concurrent program and it is mainly used to show the details of constructing a concurrent program in VISO. The second example is a larger concurrent program with more levels of abstraction. Copyright © 2000 John Wiley & Sons, Ltd.     

面向对象的逻辑图示语言

本语言介绍了图示语言基本概念及其特点，在事件驱动机制的基础上提出了逻辑驱动机制和多表达式结构，对函数式语言、逻辑语言和面向对象语言进行了理论上的分析，提出了它们在本质相容性和统一性并阐述了这三种技术在我们开发的逻辑图示语言Ｖｉｌｏｇ中的结合。     

VLISP: A verified implementation of Scheme

The VLISP project showed how to produce a comprehensively verified implementation for a programming language, namely Scheme. This paper introduces two more detailed studies on VLISP [13, 21]. It summarizes the basic techniques that were used repeatedly throughout the effort. It presents scientific conclusions about the applicability of the these techniques as well as engineering conclusions about the crucial choices that allowed the verification to succeed.The work reported here was carried out as part of The MITRE Corporation's Technology Program, under funding from Rome Laboratory, Electronic Systems Command, United States Air Force, through contract F19628-89-C-0001. Preparation of this paper was generously supported by The MITRE Corporation. Mitchell Wand's participation was partly supported by NSF and DARPA under NSF grants CCR-9002253 and CCR-9014603.     

Multiple robot programming using a concurrent logic language

Advances in robotics has led to the cooperation of multiple robots among themselves and with their industrial automation environment. Efficient interaction with industrial robots thus becomes one of the key factors in the successful utilization of this modern equipment. When multiple manipulators have to be coordinated, there is a need for a new programming approach that facilitates and encompasses the needs of concurrency, synchronization, timing, and communication. Most robot languages have been developed with little attention being given to the integration of the robot with its environment. Currently, there is a gap between the robot capabilities, the task definition environment, and language facilities supplied to use robots.This paper analyzes the needs and then establishes that a concurrent logic programming approach is a step towards achieving a multi-robot knowledgeable task programming. In particular, the FCP dialect of concurrent Prolog is demonstrated, and analyzed.This research is partially supported by the Paul Ivanier Center for research in robots and production management.     

On Efficiency and Optimization of C++ Programs

The efficiency of object-oriented programs has become a point of great interest. One necessary factor for program efficiency is the optimization techniques involved. This paper presents the performance of several variations of a given C++ program and compares them with a version that uses no object-oriented features. Our result indicates that some object-oriented features in C++ are not well optimized in current C++ compilers. We thus discuss some code optimization techniques that can improve the efficiency based on the given C++ program.     

Design of an arabic programming language (ARABLAN)

It was observed that school children in Arab countries find difficulty in learning programming in a language other than their native language. There are only few Arabic programming languages in the literature; most of which are never or partially implemented. In this paper, we present the design of a new Arabic programming language (ARABLAN) which is planned to be implemented for use in teaching programming for school children in Arab countries.     

Evaluating the Expressive Power of the Real-Time Specification for Java*

The goal of this paper is to evaluate the real-time specification for Java proposal by performing several case studies. These case studies include: an extensible general resource controller; atomic action support infrastructure; unbounded and imprecise computations. They have been used previously by the Ada community to evaluate the efficacy of the Ada concurrency and real-time models. Our results indicate that the Real-Time Specification for Java is expressive enough to cope with the demands of real-time concurrent programming. If it can be implemented efficiently, it will provide an alternative to Ada 95 for programming real-time systems.     

Cache coherence requirements for interprocess rendezvous

Multiprocessors in which a shared bus is used by the processor to communicate with common memory are an emerging class of machines where there is a need to support parallel programming languages. A language construct that is found in a number of parallel programming languages to support synchronization and communication in the interprocess rendezvous. Shared-bus multiprocessor require a protocol to keep the date in their caches coherent. There are two major categories of these protocols: invalidation and write-boadcast. This paper examines the requirements for cache coherence protocols to support efficient interprocessor rendezvous. The approach taken is to examine the memory referencing patterns to the run-time data structures during rendezvous execution. The appropriate coherence protocol is shown to be a function of the processor scheduling strategy used by the run-time system at synchronzation points during the rendezvous. When processes migrate freely as a result of the scheduling strategy, invalidation protocols are found to be more efficient. When migration is restricted by the scheduler, write-broadcast protocols are more efficient.     

How well does a vanilla loop fit into a frame?

The frame language FRL is compared with some newer object-oriented languages, namely LOOPS, the Flavor System and the Poor Man's Flavor System. The kernel features are investigated in detail and a simulation of FRL in the Flavor System is performed. The conclusion is that in general the object-oriented languages cannot be easily utilized as a substitute for FRL frames because of the different view these languages have of objects, but there are important special cases where object-oriented languages are very similar to FRL.     

On the detection of communication-related errors in concurrent programs

PMD is a framework for the detection of communication-related errors in concurrent programs using post-mortem analysis. It employs a static analysis of the source code to build a model of the program, which is dynamically enhanced with crucial run-time information from a dedicated hardware monitor. The notion of Region of Channel Usage (RCU) is introduced for detecting these errors efficiently. PMD is sufficiently general-purpose to handle a variety of concurrent programming languages, such as Occam2 and Joyce.     

基于面向对象技术的MiniC编译器的设计与实现

针对传统编译器过于抽象复杂的不足,本文提出MiniC实例语言,采用面向对象技术实现该语言的编译器。MiniC编译器可以演示复杂的程序分析过程,给出编译各阶段的详细分析结果,使编译原理中的抽象内容可视化。实际应用表明,MiniC编译器在促进人们对编译理论的理解和提高系统软件开发能力方面能够发挥重要作用。     

CCPP: 一个并发C++语言的设计与实现

并发面向对象语言ＣＯＯＬ（ｃｏｎｃｕｒｅｎｔｏｂｊｅｃｔ－ｏｒｉｅｎｔｅｄｌａｎｇｕａｇｅ）是一种有效的并发程序设计语言．本文提出了一种并发对象模型（ＣｏｎｃｕｒｅｎｔＣ＋＋,ＣＣＰＰ）及其语言．在ＣＣＰＰ并发对象模型中,所有对象都是并发对象,对象间的通讯都采用异步消息发送方式．对象间的同步采用“需要时等待”策略,同一对象内并发线程间的同步用路径表达式描述．ＣＣＰＰ语言是对Ｃ＋＋语言的扩充,采用预编译方法实现．ＣＣＰＰ语言允许并发／顺序代码重用.