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Software Engineering Journal

Issue 3 • Date May 1991

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Displaying Results 1 - 6 of 6
  • An adaptive scheduling algorithm for fault-tolerant real-time systems

    Page(s): 93 - 100
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (580 KB)  

    Particularly concerned with the deadline mechanism, proposed as a means to design and implement fault-tolerant real-time systems. The computing system considered uses a single-processor machine to run multiple software processes; each of them executes a task in response to periodic requests. Based on redundancy the deadline mechanism assumes that every task is composed of primary and alternate algorithms. In such a context, the scheduling problem that arises amounts to ensuring timely completion of all the requests, either by primaries or alternates but preferably by primaries whenever possible. The authors present a heuristic scheduling strategy, which is optimal and runs in linear time View full abstract»

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  • Requirements engineering for real-time systems

    Page(s): 101 - 115
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1264 KB)  

    Outlines techniques to support requirements engineering for real-time systems. The nature of real-time embedded systems requirements are discussed. Some key areas that may be expected to contribute to improved requirements engineering techniques are reviewed. A detailed discussion of the FOREST approach, which has been developed to support requirements engineering for real-time systems, is given and accompanied by an illustrative example View full abstract»

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  • Concurrent C: real-time programming and fault tolerance

    Page(s): 83 - 92
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (696 KB)  

    Concurrent C is an upward-compatible parallel extension of C which runs on a variety of uniprocessors and multiprocessors. A concurrent C program consists of a set of processes which execute in parallel and interact with each other by sending messages. Fault-tolerant (FT) concurrent C, an extension of concurrent C, is a tool for writing fault-tolerant distributed programs based on the replication of critical processes. All details of interaction with replicated (fault-tolerant) processes are handled by the FT concurrent C runtime system. Consequently, writing fault-tolerant distributed programs is almost the same as writing ordinary distributed programs. This paper describes concurrent C, discusses its real-time facilities and describes FT concurrent C View full abstract»

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  • The design of real-time systems: from specification to implementation and verification

    Page(s): 72 - 82
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (868 KB)  

    Presents an engineering approach to the design of distributed real-time systems, which guarantee hard deadlines and can tolerate a specified set of faults. The methodology covers the stepwise refinement of the given requirements, expressed in the form of real-time transactions, to task and protocol executions. It also includes a timing analysis and dependability evaluation of the still incomplete design. The testability of the evolving system is considered to be of essential concern. A set of coherent tools for the support of the methodology is described in some detail. The methodology assumes that the runtime architecture is based on static scheduling, and a globally synchronised time-base is available to co-ordinate the system actions in the domain of real time View full abstract»

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  • Real-world software engineering

    Page(s): 68 - 71
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (340 KB)  

    Explains what is being done to cope with the real-world problems in information system development: the large size, long timescale, availability and responsiveness. The pervasive theme is that the software engineering paradigm is important but inadequate; the interaction between software and hardware is fundamental. The author considers methods available for predicting software resource needs and the difficulty of working with virtual machines, amongst other issues View full abstract»

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  • Scheduling hard real-time systems: a review

    Page(s): 116 - 128
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    Results of the application of scheduling theory to hard real-time systems are reviewed in this paper. The review takes the form of an analysis of the problems presented by different application requirements and characteristics. Issues covered include uniprocessor and multiprocessor systems, periodic and aperiodic processes, static and dynamic algorithms, transient overloads and resource usage. Protocols that limit and reduce blocking are discussed. Consideration is also given to scheduling Ada tasks View full abstract»

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