Ada并发程序设计

<正> 该书1984年出版,作者系美国贝尔实验室的Narain Gehani。该书从公认的第一个提供高级通用并发程序设计设施的Ada语言着手,全面地介绍了Ada语言中的并发程序设计设施,以及如何有效利用这些设施编写并发程序;概述了在其它语言的并发程序设计设施;讨论了并发程序设计中的一些细节问题;书末还附录了Ada顺序程序设计的概要。目前,各种大小的并行计算机及操作系统都已相继问世并投入实际使用。并行处理将是今后几年计算机工程和应用的发展方向之一,也是新一代计算机的核心技术之一。但是如果缺乏高度并行的程序设计语言和方法,将会给广泛的应用带来很大障碍,这已引起计算机各     

Ada并发程序设计

<正> 该书1984年出版,作者系美国贝尔实验室的Narain Gehani。 该书从公认的第一个提供高级通用并发程序设计设施的Ada语言着手,全面地介绍了Ada语言中的并发程序设汁设施,以及如何有效利用这些设施编写并发程序;概述了在其它     

Ada并发程序设计

<正> 死锁,不一定的时序和不一定的轮询都是并发程序设计问题,这些问题通常对顺序程序设计不感兴趣,甚至无关。这些问题发生在并发程序设计之中,而不管程序设计语言提供了什么样的并发程序设计设施。但是,程序设计语言中的并发设施的精确特性对这些问题的严重性与经常性确有影响。本章讨论三个并发程序设计问题:死锁,程序中的最大并发特性,以及Ada中的轮询偏向。 1.死锁当程序中的一个或多个任务被永远阻塞时,死锁就发生了,因为需求不能满足。在一些任务中,死锁会成为某些任务中的一种     

Implementing Ada Exceptions

Can exceptions be implemented for Ada without imposing overhead on normal execution? Yes, as long as certain rules are followed.     

The Power of Ada

Many new programming languages offer little beyond traditional features and lack a compelling reason for the industry to adopt them. However, the Ada programming language, developed and promoted by the Department of Defense, offers powerful new capabilities for developing large programs, ultimately improving the ability to deploy reliable and less costly information systems.     

Ada programming language standardization

The need for software management and standardization of programming languages used in military systems was first identified by DoD in 1975. DoD at that time supported many limited use languages for what are now called embedded computer applications. This diversity of languages contributed to high software costs. In November 1976, DoD first established seven approved , , , -J3, -J73, , -2, -1. Eventually the number of approved DoD languages may be reduced to three, Ada, , and . Ada was established as Military Standard 1815, on 10 December 1980. The ANSI standardization process for Ada is in progress. The Ada concept places restrictions on what may be called an Ada compiler. Compilers may not be called Ada compilers until they have passed validation tests. Up to 80% of software costs are incurred after the software has been put into service. Ada can promote a programming style that leads to maintainable software. It is in the program maintenance phase of the software life cycle where large savings will be achieved through the use of Ada.     

Debugging Ada Tasking Programs

Debuggers for parallel programs have to be more than passive information gatherers-they should automatically detect errors. Powerful task debuggers for Ada can be constructed by extending existing tools that detect deadlock.     

What is Ada?

This introduction to the principal features of Ada emphasizes those aspects expected to offer significant advantage in large-scale program development.     

Experience with multi-transputer Ada

The transputer is one of the most cost-effective multicomputer components to buy, but still one of the hardest to program. Even if the parts of a program that are destined for individual transputers are programmed in a familiar high-level language (Ada or Fortran or C), users are forced to be aware of occam when connecting transputers together with harnesses. Moreover, the design of parallel and distributed algorithms is in itself a challenging field. This paper describes experience with using the Alsys Ada compiler on single and multiple transputer configurations, and considers whether Ada makes it any easier to gain access to the power of multi-transputers. Early performance figures indicate that Ada running on transputer arrays compares favourably with the speed of other languages. An assessment of the impact of the proposed Ada 9X support for distribution is made.     

Refinement Methodology for Ada

This paper presents Refinement Methodology (RM) for the design of Ada® programs. The methodology combines stepwise refinement and the information hiding principle. The steps of the methodology are explained and illustrated by an example. A part of the methodology is a collection of rules by which procedures acquire parameters (called first and second rules for parameters).     

The Ada Language System

The ALS–a portable, retargetable, integrated environment–is being designed to meet rigorous Stoneman requirements. It addresses critical development and maintenance problems of embedded computer systems.     

The Power of Ada

Many new programming languages offer little beyond traditional features and lack a compelling reason for the industry to adopt them. However, the Ada programming language, developed and promoted by the Department of Defense, offers powerful new capabilities for developing large programs, ultimately improving the ability to deploy reliable and less costly information systems.     

Reusability Issues and Ada

How do you write reusable code when your methodology doesn't address reusability? These guidelines bility? These guidelines developed by a major defense contractor may help.     

一种Ada83服务性任务向Ada95保护对象变换的方法

任务是Ada语言支持并发程序设计的基础,它提供了一种进程同步和通信的良好机制.但也存在一类被动的、专为其他任务服务的服务性任务.服务性任务的存在增加了系统的负担,降低了系统的性能.如果能将服务性任务变换为保护对象,则可以明显地提高系统的性能,减少维护的费用.该文提出了一种在源程序级将Ada83服务性任务变换为Ada95保护对象的方法.先给出服务性任务应满足的条件、识别和表示服务性任务的方法,最后讨论此方法的可行性.与其他方法相比,此方法具有假设条件少、识别和变换效率高以及容易验证等特点.