We have adapted an interactive programming system (Smalltalk) to a multiprocessor (the Firefly). The task was not as difficult as might be expected, thanks to the application of three basic strategies: serialization, ...
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A design and verification technique for implementation schemes of distributed software is presented. In this technique, first, the specification is modelled by a concurrent object system, that is, one which is constit...
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ISBN:
(纸本)0897912845
A design and verification technique for implementation schemes of distributed software is presented. In this technique, first, the specification is modelled by a concurrent object system, that is, one which is constituted of computational agents with capability of concurrent execution and message passing. Then, such a concurrent object system is transformed into another concurrent object system, which models a sophisticated implementation scheme. Our transformation technique is mainly based on fusing and splitting concurrent objects. The correctness of transformation rules can be proven formally.
The programming of the interrupt handling mechanisms, process switching primitives, scheduling mechanisms, and synchronization primitives of an operating system for a multiprocessor require both efficient code in orde...
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ISBN:
(纸本)0897912845
The programming of the interrupt handling mechanisms, process switching primitives, scheduling mechanisms, and synchronization primitives of an operating system for a multiprocessor require both efficient code in order to support the needs of high-performance or real-time applications and careful organization to facilitate maintenance. Although many advantages have been claimed for object-oriented class hierarchical languages and their corresponding design methodologies, the application of these techniques to the design of the primitives within an operating system has not been widely demonstrated. To investigate the role of class hierarchical design in systems programming, the authors have constructed the Choices multipxocessor operating system architecture using the C++ programminglanguage. During the implementation, it was found that many operating system design concerns can be represented advantageously using a class hierarchical approach, including: the separation of mechanism and policy;the organization of an operating system into layers, each of which represents an abstract machine;and the notions of process and exception management. In this paper, we discuss an implementation of the low-level primitives of this system and outline the strategy by which we developed our solution.
The focus of this paper is the conjecture that the coding phase of a software system is difficult even in those instances where the functional requirements are well-defined, the functional design is finalized, and the...
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ISBN:
(纸本)0897912853
The focus of this paper is the conjecture that the coding phase of a software system is difficult even in those instances where the functional requirements are well-defined, the functional design is finalized, and the implementation issues are well-understood. To study this conjecture, we examined an actual implementation of a stack to discover what decisions the programmer encounters when attempting to transform the functional design into operational software code. We examine decisions affecting the specification of the stack package as well as those affecting the implementation of the subprograms in the body of this package.
Access to the variety of resources offered by computer networks is often complicated by the diversity of interfaces and protocols encountered. To overcome this diversity, a command-and-response language interface to a...
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ISBN:
(纸本)0818608420
Access to the variety of resources offered by computer networks is often complicated by the diversity of interfaces and protocols encountered. To overcome this diversity, a command-and-response language interface to a network of heterogeneous systems is proposed. A brief account of previous work in command languages and system interfaces motivates the study of a prototype of the proposed interface. The design, implementation, and lessons learned through the successful realization of the prototype are presented.
The structure and design of a simulation testbed for communication systems are described. The testbed, which is called the Distributed Simulation and Prototyping Testbed (DSPT), models the physical-layer activities of...
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ISBN:
(纸本)0818608420
The structure and design of a simulation testbed for communication systems are described. The testbed, which is called the Distributed Simulation and Prototyping Testbed (DSPT), models the physical-layer activities of communication networks with a design that facilitates the addition of higher-layer protocols either as part of the simulation program itself or as prototype software that can execute concurrently with the simulation on a separate machine. As is typical of R&D systems, the DSPT requirements have evolved with the projects that it supports. The author shows some of the benefits of developing software using the object-oriented methodology in the dynamic R&D environment. The design involved extensions to the Simula programminglanguage, which were easily implemented using Simula's class inheritance capability. The author explores these extensions and discusses further needs of the Simula language that appeared during the implementation of the DPST.
We describe the automatic generation of a complete, realistic compiler from formal specifications of the syntax and semantics of Sol/C, a nontrivial imperative language “sort of like C.” The compiler exhibits a thre...
ISBN:
(纸本)9780897912693
We describe the automatic generation of a complete, realistic compiler from formal specifications of the syntax and semantics of Sol/C, a nontrivial imperative language “sort of like C.” The compiler exhibits a three pass structure, is efficient, and produces object programs whose performance characteristics compare favorably with those produced by commercially available compilers. To our knowledge, this is the first time that this has been accomplished.
We present a design system shell which can be used to experiment with principles of design and be used as a design tool where complex layers of information need to be specified about objects, such as in database desig...
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Opus is a tool for rule-based programming which integrates a production system paradigm with the Smalltalk-80 environment. Opus currently provides a data-driven production system that allows the programmer considerabl...
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