令网疯狂令我醉的ML

HTML大家一定不会陌生,我做了一个主页,其中就有不少.htm文件,不过我的主页确实不够美观,干巴巴的一些文字、图像。     

GCLISP对其他高级语言的调用方法

目前的GCLISP版本,对用其他高级语言编写的程序交互能力差,这对需要进行复杂计算或想直接调用其他高级语言编写的“标准程序”的用户造成了一定的困难。本文介绍了作者在使用GCLISP调用其他高级语言的一点体会,提出了用高级批处理的方法来解决这种联接调用。这对使用GCLISP的用户可能会有一定的启发。     

Ada语言与Occam语言的比较

一、引言过去十年在计算语言领域的重要进展之一是出现了具有并行计算能力的Ada语言和Occam语言。Ada语言是具有类似Pascal语言的控制结构,并且能重植入过程和函数的大型语言,其初始设计目标是满足美国国防部所规定的要求,即首先考虑支持适于军事装备的嵌入式编程系统。就本质而言,Ada语言是在串行语言的结构上,扩充增加了并发执行的能力。 Occam语言是和Transputer同时设计实     

Source-to-Source Conversion Based on Formal Definition

This paper proposes the idea of source-to-source conversion between two heterogeneous high-level programming languages.The conversion is based on formal definition and oriented to multi-pairs of languages.The issues in conversion from PASCAL to C are also discussed.     

怎样选择一门语言

许多高校将取得计算机等级考试相应的证书作为学生毕业的必要条件之一，因此不少新生刚入学就末雨绸缪，准备考级，但在其中对程序语言的选择却充满了困惑，甚至感到无所适从。这里我就语言的选择发表一些自己的看法。选择语言要坚持以下几个方面的原则：（一）空间性原则空间性原则指的是要确定你选择的语言在你所计划的整个计算机系统学习中的地位。也就是说，在选择一门语言时，要了解其在计算机学习过程中所处的地位，在你以后的计算机系统学习过程，是否可以使用到这门语言，从而相对减少学习量。例如C语言，在以后学习数据结构这门专…     

ARTDBL-基于SQL的主动实时数据库语言

提出了一种新型的主动实时数据库语言（ＡＲＴＤＢＬ），它是传统的标准ＳＱＬ语言的扩充。讨论了ＡＲＴＤＢＬ的设计思想、功能特色和使用方式。该语言现已成功地应用到ＡＲ－ＴＤＢＳ中     

C#是一种新的语言？或者仅仅只是J……

C＃与Java两者在相似性外,又是非常不同的,它们有许多细微的语义和设计区别,适台不同的技术和市场环境     

从VB到VBA

多年来,Microsoft公司一直对新闻界及开发人员暗示,它的长远策略包括一种通用的应用程序编程语言。这种语言将用于微软的所有应用程序中,它起源于应用得相当广泛的计算机语言—VB。这种语言将向高级用户及开发人员提供一种应用程序间通用的应用程序语言(也就是宏语言),因而可以减少学习时间和支持费用;而且这种语言也会为开发人员提供一种开发方法,用于开发集成多个应用程序的系统,即多个应用程序协调工作,以解决商业上的问题。 这个期待已久的语言就是Visual Basic for Application(简称VBA)。包括这种语言的第一个微软产品就是Excel 5.0。VBA为高级用户及开发人员提供了使用这种最通用的Windows编程语言—Visual Basic的能力,并可以将它应用到Excel的问题中。它也使得用户可以更容易控制其它Microsoft的应用程序。 虽然VBA起源于VB,但它成为一个对应用程序几乎没     

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.     

How to solve the Santa Claus problem

John Trono (1994) published a new exercise in concurrent programming – the Santa Claus problem – and provided a solution based on semaphores. His solution is incorrect because it assumes that a process released from waiting on a semaphore will necessarily be scheduled for execution. We give a simple solution in Ada 95 using higher-order synchronization primitives: protected objects and rendezvous. We then give a solution in Java, although this solution is not as elegant as the Ada 95 solution because the Java synchronization primitives are rather limited. The problem demonstrates that semaphores, designed for low-level mutual exclusion, are not appropriate for solving difficult concurrent programming problems. © 1998 John Wiley & Sons, Ltd.     

Extending conventional languages by distributed/concurrent exception resolution

The state of art in handling and resolving concurrent exceptions is discussed and a brief outline of all research in this area is given. Our intention is to demonstrate that exception resolution is a very useful concept which facilitates joint forward error recovery in concurrent and distributed systems. To do this, several new arguments are considered. We understand resolution as reaching an agreement among cooperating participants of an atomic action. It is provided by the underlying system to make it unified and less error prone, which is important for forward error recovery, complex by nature. We classify atomic action schemes into asynchronous and synchronous ones and discuss exception handling for schemes of both kinds. The paper also deals with introducing atomic action schemes based on exception resolution into existing concurrent and distributed languages, which usually have only local exceptions. We outline the basic approach and demonstrate its applicability by showing how exception resolution can be used in Ada 83, Ada 95 (for both concurrent and distributed systems) and Java. A discussion of ways to make this concept more object-oriented and, with the help of reflection, more flexible and useful, concludes the paper.     

Coping with Java threads

A thread is a basic unit of program execution that can share a single address space with other threads - that is, they can read and write the same variables and data structures. Originally, only assembly programmers used threads. A few older programming languages such as PL/I supported thread concurrency, but newer languages such as C and C++ use libraries instead. Only recently have programming languages again begun to build in direct support for threads. Java and Ada are examples of industry-strength languages for multithreading. The Java thread model has its roots in traditional concurrent programming. As the "real-time specification for Java" sidebar describes, RTSJ attempts to remove some of the limitations relative to real-time applications - primarily by circumventing garbage collection. But RTSJ does not make the language safer. It retains standard Java's threading pitfalls and is a risky candidate for critical concurrent applications.     

Ada program partitioning language: a notion for distributing Adaprograms

Ada Program Partitioning Language (APPL) has been designed as part of Honeywell's Distributed Ada project. The goal of the project is to develop an approach for reducing the complexity of building distributed applications in Ada. In the proposed approach, an application is written as a single Ada program using the full capabilities of the Ada language. It is not necessary to factor the underlying hardware configuration into the program design. Once the program has been completed and tested in the host development environment, it is partitioned into fragments and mapped onto the distributed hardware. The partitioning and mapping are expressed in APPL and do not require changes to the Ada source. The main thrusts of the project include the design of APPL and the development of language translation tools and the run-time system to support Ada and APPL for a distributed target. The authors present an overview of APPL, the goals considered in the design, and issues that impact its implementation     

ARTK-M2: A kernel for Ada tasking requirements: An implementation and an automatic generator

A run-time kernel, ARTK-M2, supporting Ada tasking semantics is discussed; full support for task creation, synchronization, communication, scheduling, and termination is provided, together with all options of the Ada rendezvous. An implementation in Modula-2 is presented and a method for automatically translating Ada programs into semantically equivalent Modula-2 programs with corresponding kernel calls is introduced. A parser generator and an attribute grammar were used for the automatic translation. A subset of the Ada Compiler Validation Capability was processed to test the implementation and to illustrate the translation mechanism. The kernel is applicable to the study of real-time control systems; it can also serve as a baseline for studying implementation alternatives of Ada concepts, such as new scheduling algorithms, and for analysing new language constructs. Work is under way to implement some of the changes to the Ada tasking model being proposed as a result of the language revision (Ada9X). Finally, through proper extensions, ARTK-M2 can form an integral part of programming tools such as an Ada compilation system and a distributed kernel for multi-processing environments.     

Concurrent programming in the Ada® language: The polling bias

The rendezvous is an important concept in concurrent programming—two processes need to synchronize, i.e. rendezvous, to exchange information. The Ada programming language is the first programming language to use the rendezvous as the basis of its concurrent programming facilities. Our experience with rendezvous facilities in the Ada language shows that these facilities lead to and encourage the design of programs that poll. Polling is generally, but not always, undesirable because it is wasteful of system resources. We illustrate and examine the reasons for polling bias in the Ada language. We give suggestions on how to avoid polling programs, and suggest changes to the rendezvous facilities to eliminate the polling bias. The ramifications of these changes to the implementation of the Ada language are also discussed. Although we have focused on the rendezvous facilities in the Ada language our analysis is also applicable to other languages. A polling bias can occur in any concurrent programming language based on the rendezvous mechanism if it does not provide appropriate facilities.     

Real-time interrupt handling in Ada

The Ada? programming language defines the semantics of interrupt handling as part of the tasking mechanism, making it possible to construct implementation-independent interrupt handlers. However, for the Ada mechanism to be effective, an implementation must provide support not specified by the Ada standard, such as for initializing hardware interrupting devices, handling unexpected interrupts and optimizing for real-time performance constraints. This paper analyses some of the constraints that efficient interrupt support places on an implementation. It develops a model for the interaction between interrupt hardware and Ada tasks and describes optimizations for Ada interrupt handlers. Implementation issues, including task priorities and task termination for interrupt handlers, are discussed in detail.     

基于Ada的交叉引用语言CRL/Ada

本文介绍一种基于Ａｄａ的交叉引用语言ＣＲＬ／Ａｄａ,它用于描述Ａｄａ程序实体的定义与引用信息,在软件维护的过程中,利用它可以方便地获得软件源程序中的实体信息。本文将介绍它的设计思想、程序结构与应用。     

Software CAD: a revolutionary approach

A research project is described in which an experimental software CAD environment called the Carleton embedded system design environment (CAEDE), oriented toward embedded systems and Ada, was developed to provide a demonstration of the concept and to serve as a research testbed. The major contribution of CAEDE is a demonstration of a visual paradigm which combines semantic depth and syntactic shallowness, relative to Ada, in a manner that makes it possible for the embedded-system designer to work in terms of abstract machines while still thinking Ada. A secondary contribution is the identification of Prolog as a promising approach for supporting tool development in an environment which supports the visual paradigm. Also described are experimental tools for temporal analysis, performance analysis, and the generation of skeleton Ada code