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Real-Time Operating Systems and Software, 1994. RTOSS '94, Proceedings., 11th IEEE Workshop on

Date 18-19 May 1994

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Displaying Results 1 - 23 of 23
  • Proceedings of 11th IEEE Workshop on Real-Time Operating Systems and Software

    Publication Year: 1994
    Request permission for commercial reuse | PDF file iconPDF (26 KB)
    Freely Available from IEEE
  • Real-time communication in FDDI-based reconfigurable networks

    Publication Year: 1994, Page(s):49 - 52
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (324 KB)

    We report our ongoing research in real-time communication with FDDI-based reconfigurable networks. The original FDDI architecture was enhanced in order to improve its fault-tolerance capability while a scheduling methodology, including message assignment, bandwidth allocation, and bandwidth management is developed to support real-time communication. As a result, message deadlines are guaranteed ev... View full abstract»

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  • Correlation analysis techniques for refining execution time estimates of real-time applications

    Publication Year: 1994, Page(s):54 - 58
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (372 KB)

    Scheduling techniques based upon worst case execution times, as are commonly used in real-time applications, often result in severe underutilization of the processor resources since most tasks finish in much less time than their anticipated worst-case execution times. We describe techniques for identifying correlation among the executions of various statements within a program. We demonstrate how ... View full abstract»

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  • Issues of advanced architectural features in the design of a timing tool

    Publication Year: 1994, Page(s):59 - 62
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (268 KB)

    This paper describes a timing tool being developed by a real-time research group at Seoul National University. Our focus is on the issues resulting from advanced architectural features such as pipelined execution and cache memories found in many modern RISC-style processors. For each architectural feature we state the issues and explain our approach View full abstract»

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  • Timing analysis of superscalar processor programs using ACSR

    Publication Year: 1994, Page(s):63 - 67
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    This paper illustrates a formal technique for describing the timing properties and resource constraints of pipelined superscalar processor instructions at high level. Superscalar processors can issue and execute multiple instructions simultaneously. The degree of parallelism depends on the multiplicity of hardware functional units as well as data dependencies among instructions. Thus, the timing p... View full abstract»

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  • Task scheduling for real-time multi-processor simulations

    Publication Year: 1994, Page(s):70 - 73
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    Scheduling of tasks onto multi-processors is an increasingly important problem in the simulation of avionics systems. The problem is difficult due to the many hard real-time constraints imposed on the schedule in the form of processor frame-time limits and latency requirements. In this paper, we present a solution to this real-time scheduling problem using simulated annealing techniques. The runni... View full abstract»

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  • On latency management in time-shared operating systems

    Publication Year: 1994, Page(s):86 - 90
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (312 KB)

    The design of general purpose operating systems impose constraints on the way one can structure real-time applications. This paper addresses the problem of minimizing the end-to-end latency of applications that are structured as a set of cooperating (real-time) tasks. When applications are structured as a set of cooperating tasks the time required for data to progress from an input task to an outp... View full abstract»

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  • Predictable spin lock algorithms with preemption

    Publication Year: 1994, Page(s):2 - 6
    Cited by:  Papers (8)  |  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (392 KB)

    Both predictable interprocessor synchronization and fast interrupt response are required for real-time systems constructed using asymmetric shared-memory multiprocessors. This paper points out the problem that conventional spin lock algorithms cannot satisfy both requirements at the same time. To solve this problem, we have proposed an algorithm which is an extension of queueing spin locks modifie... View full abstract»

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  • Using SDL in embedded systems design: a tool for generating real-time OS pSOS based embedded systems applications software

    Publication Year: 1994, Page(s):39 - 43
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB)

    We present an efficient method using the Specification and Description Language (SDL) for designing and implementing real-lime embedded systems. We also discuss the implementation of a companion kernel for an SDL based Design Tool (SDT) CASE tool environment to generate real-time OS based pSOS multitasking application software by applying defined mapping translation rules. Since SDL is a formal sp... View full abstract»

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  • Successful use of rate monotonic theory on a formidable real time system

    Publication Year: 1994, Page(s):74 - 78
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (348 KB)

    The navigation payload software for the next block of Global Positioning System satellites recently completed testing. The computer program for the onboard computer is sufficiently complex to expose almost every issue that has been put forward in rate monotonic theory. The success of this effort demonstrates the utility of the theory in this type of application. The system designed required the pr... View full abstract»

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  • An argument for a runtime layer SPARTA design

    Publication Year: 1994, Page(s):91 - 95
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (384 KB)

    Researchers have used advances in hardware technology to design larger and more complex real-time applications. Larger applications require new integration techniques while more complex applications require a restructuring of the underlying system support. We examine the system design issues of supporting SPARTAs (Soft Parallel Real-Time Applications). There exists a gap between hard real-time ker... View full abstract»

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  • User-level real-time threads

    Publication Year: 1994, Page(s):7 - 11
    Cited by:  Papers (7)  |  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB)

    Continuous-media applications require more efficient and flexible support from real-time threads than traditional real-time systems. It includes functionalities such as the dynamic management of thread attributes and the support of multiple thread models. We describe the design and implementation of user-level real-time threads on the RT-Mach micro kernel. Since they are implemented at user-level,... View full abstract»

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  • Practical formal development of real-time systems

    Publication Year: 1994, Page(s):44 - 48
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (308 KB)

    The complexities of real-time systems are such that it is often thought necessary to give a formal justification of their correctness especially if they are to be used in a safety-critical environment. We describe our work on a formally based design method for real-time systems which allows the timing aspects of a concurrent system to be mathematically described and verified, as well as semi-autom... View full abstract»

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  • Using data similarity to achieve synchronization for free

    Publication Year: 1994, Page(s):112 - 116
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    M.H. Graham (1993) proposed several conditions which are sufficient to guarantee that a transaction system will run serializably without any extra effort having to be taken. Systems satisfying these conditions are said to achieve serializability for free. The conditions considered by Graham are determined by a syntactic check on the transaction programs, and are independent of the semantics of dat... View full abstract»

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  • Temporal protection in real-time operating systems

    Publication Year: 1994, Page(s):79 - 83
    Cited by:  Papers (18)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (336 KB)

    Real-time systems manipulate data types with inherent timing constraints. Priority-based scheduling is a popular approach to build hard real-time systems, when the timing requirements, supported run-time configurations, and task sets are known a priori. Future real-time systems will need to support these hard real-time constraints but in addition (a) provide friendly user and programming interface... View full abstract»

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  • Constructing a heterogeneous real-time system

    Publication Year: 1994, Page(s):34 - 38
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB)

    The construction of a real-time system on heterogeneous hardware platforms, forces one to make choices on which programming language, operating system, development process and application programmers interface to use. The application (a micro-satellite) requirements state that the system must be dependable in a remote and harsh environment such as space. This paper details the choices made and the... View full abstract»

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  • Window-consistent replication for real-time applications

    Publication Year: 1994, Page(s):107 - 111
    Cited by:  Papers (2)  |  Patents (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (392 KB)

    Two widely-studied approaches for structuring fault-tolerant services are the state-machine and the primary-backup replication schemes. For a large class of soft and hard real-time applications, the degree of consistency among servers can be exploited to design replication protocols with predictable timing behavior. This is particularly useful in applications such as automated process control, in ... View full abstract»

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  • A linear-time online task assignment scheme for multiprocessor systems

    Publication Year: 1994, Page(s):28 - 31
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (284 KB)

    A new online task assignment scheme is presented for multiprocessor systems where individual processors execute the rate-monotonic scheduling algorithm. The computational complexity of the task assignment scheme grows linearly with the number of tasks, and its performance is shown to be significantly better than previously existing schemes. The superiority of the assignment scheme is achieved by a... View full abstract»

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  • A mixed locking/abort protocol for hard real-time systems

    Publication Year: 1994, Page(s):102 - 106
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB)

    Serializability greatly simplifies reasoning about correctness in concurrent systems, including real-time systems. Our research addresses concurrency control protocols that accommodate analytic guarantees of schedulability, can be implemented with small bounded overheads and blocking, and ensure serializable execution of entire tasks including complete read/compute/write cycles (as opposed to seri... View full abstract»

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  • Appropriate mechanisms for the support of optional processing in hard real-time systems

    Publication Year: 1994, Page(s):23 - 27
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (432 KB)

    It has been recognised that future hard real-time systems need to be more flexible than current scheduling theory permits. One method of increasing flexibility is the incorporation, at run-time, of optional components into processes with hard deadlines. Such components are not guaranteed offline, but may be guaranteed at run-time if sufficient resources are available. This is achieved by providing... View full abstract»

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  • Real-time platforms and environments for time constrained flexible manufacturing

    Publication Year: 1994, Page(s):96 - 99
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (292 KB)

    The Spring Kernel and associated algorithms, languages, and tools provide system support for static or dynamic real-time applications that require predictable operation. Spring currently consists of two major parts: (1) the development environment, where application and target systems are described, preprocessed and downloaded, and (2) the run-time environment, where the operating system, the Spri... View full abstract»

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  • An end-to-end approach to schedule tasks with shared resources in multiprocessor systems

    Publication Year: 1994, Page(s):18 - 22
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (348 KB)

    We propose an end-to-end approach to scheduling tasks that share resources in a multiprocessor or distributed systems. In our approach, each task is mapped into a chain of subtasks, depending on its resource accesses. After each subtask is assigned a proper priority, its worst-case response time can be bounded. Consequently the worst-case response time of each task can be obtained and the schedula... View full abstract»

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  • Experience with a prototype of the POSIX “minimal realtime system profile”

    Publication Year: 1994, Page(s):12 - 16
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    This paper describes experience in prototyping the proposed IEEE standard “Minimal Realtime System Profile”, whose primary component is support for real-time threads. It provides some background, describes the implementation, and reports preliminary performance measurements View full abstract»

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