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[1990] Proceedings 11th Real-Time Systems Symposium

5-7 Dec. 1990

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Displaying Results 1 - 25 of 34
  • Proceedings. 11th Real-Time Systems Symposium (Cat. No.90CH2933-0)

    Publication Year: 1990
    Request permission for commercial reuse | PDF file iconPDF (129 KB)
    Freely Available from IEEE
  • Resource reclaiming in real time

    Publication Year: 1990, Page(s):41 - 50
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (964 KB)

    Resource reclaiming refers to the problem of utilizing the resources left unused by a task when it executes in less than its worst-case computation time, or when a task is deleted from the current schedule. In dynamic real-time multiprocessor environments, resource reclaiming can be used to improve the average performance. Dynamic resource reclaiming algorithms must be effective in reclaiming unus... View full abstract»

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  • A stack-based resource allocation policy for realtime processes

    Publication Year: 1990, Page(s):191 - 200
    Cited by:  Papers (94)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (764 KB)

    The stack resource policy (SRP) is a resource allocation policy which permits processes with different priorities to share a single runtime stack. It is a refinement of the priority ceiling protocol (PCP), which strictly bounds priority inversion and permits simple schedulability tests. With or without stack sharing, the SRP offers the following improvements over the PCP: (1) it unifies the treatm... View full abstract»

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  • New latency bounds for atomic broadcast

    Publication Year: 1990, Page(s):156 - 165
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (596 KB)

    Tighter bounds are provided on the time required to reach agreement in a distributed system as a function of the failure model. After describing the model of a distributed system that is a context for this work the authors define several failure classes. They define a partial order on classes of failures that involves whether there is a latency penalty in converting from tolerance of one failure c... View full abstract»

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  • Scheduling I/O requests with deadlines: A performance evaluation

    Publication Year: 1990, Page(s):113 - 124
    Cited by:  Papers (42)  |  Patents (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (992 KB)

    The I/O scheduling problem is examined in detail. The authors present a realistic model for studying this problem in the context of a system which executes real-time transactions. The model takes advantage of the fact that reading from the disk occurs before a transaction commits, while writing to the disk usually occurs after the transaction commits. New algorithms are presented that exploit this... View full abstract»

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  • Preemptively scheduling hard-real-time sporadic tasks on one processor

    Publication Year: 1990, Page(s):182 - 190
    Cited by:  Papers (253)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (576 KB)

    Consideration is given to the preemptive scheduling of hard-real-time sporadic task systems on one processor. The authors first give necessary and sufficient conditions for a sporadic task system to be feasible (i.e., schedulable). The conditions cannot, in general, be tested efficiently (unless P=NP). They do, however, lead to a feasibility test that runs in efficient pseudo-polynomial time for a... View full abstract»

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  • Real-time communication in multiple token ring networks

    Publication Year: 1990, Page(s):146 - 154
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (560 KB)

    A communication architecture and a dynamic control protocol are presented for real-time communication in multiple token ring networks. The network can be formed by multiple channels through bandwidth subdivision of a high-speed ring. A flexible preemption and dynamic load allocation scheme is developed which can reduce the lost percentage of critical packets and can maintain a high channel utiliza... View full abstract»

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  • Concurrency control in real-time databases by dynamic adjustment of serialization order

    Publication Year: 1990, Page(s):104 - 112
    Cited by:  Papers (42)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (720 KB)

    A new concurrency control algorithm for real-time database systems is proposed, by which real-time scheduling and concurrency control can be integrated. The algorithm is founded on a priority-based locking mechanism to support time-critical scheduling by adjusting the serialization order dynamically in favor of high priority transactions. Furthermore, it does not assume any knowledge about the dat... View full abstract»

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  • A robust group membership algorithm for distributed real-time systems

    Publication Year: 1990, Page(s):173 - 179
    Cited by:  Papers (18)  |  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (584 KB)

    An algorithm is presented by which nonfaulty processors of a group of fixed size will be able to maintain a consistent and timely knowledge of the group membership. The authors assume an architecture in which the broadcast network is accessed by some time domain multiplexing techniques where the exclusive right to transmit messages is granted to each processor once in every `cycle'. In an executio... View full abstract»

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  • Analysis of three contention protocols in distributed real-time systems

    Publication Year: 1990, Page(s):136 - 145
    Cited by:  Papers (10)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (824 KB)

    The probability of a station/node failing to deliver packets before their deadlines, called the probability of dynamic failure, P dyn, and the ∈-bounded delivery time, which is defined as the time period between the arrival of a packet and its delivery with probability greater than 1-∈, are important performance parameters for the communication subsystems of a distrib... View full abstract»

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  • Implementing a verifier for real-time systems

    Publication Year: 1990, Page(s):62 - 71
    Cited by:  Papers (12)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (876 KB)

    The SARTOR project has as one of its goals the development of an environment for the development of correct real-time systems. Modechart is a specification language for real-time systems developed as part of this project. Verify4 is an implementation of a verifier for certain classes of properties of systems specified using Modechart. The author describes the program Verify4 and addresses implemen... View full abstract»

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  • Real-time scheduling support in Futurebus+

    Publication Year: 1990, Page(s):331 - 340
    Cited by:  Papers (13)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (980 KB)

    A simple but efficient architecture for building multiprocessors is to connect several processors to a common backplane bus. The backplane acts as a shared resource in this architecture and contention for its use by different bus modules must be resolved. In a real-time system, this backplane must also provide scheduling support such that the timing behavior of the resulting system is analyzable. ... View full abstract»

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  • A calculus for communicating systems with time and probabilities

    Publication Year: 1990, Page(s):278 - 287
    Cited by:  Papers (34)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (628 KB)

    A process algebra that extends R. Milner's (1983) calculus of communicating systems (CCS) with probabilities and time is presented. With this calculus it is possible to describe real-time and reliability aspects of distributed systems. A (strong) bisimulation equivalence is defined, and a corresponding complete axiomatization is given. Several examples are included View full abstract»

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  • Dynamic real-time optimistic concurrency control

    Publication Year: 1990, Page(s):94 - 103
    Cited by:  Papers (44)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (772 KB)

    The authors (1990) have shown that in real-time database systems that discard late transactions, optimistic concurrency control outperforms locking. Although the optimistic algorithm used in that study, OPT-BC, did not factor in transaction deadlines in making data conflict resolution decisions, it still outperformed a deadline-cognizant locking algorithm. A discussion is presented of why adding d... View full abstract»

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  • A tagged memory technique for recovery from transient errors in fault tolerant systems

    Publication Year: 1990, Page(s):312 - 321
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (648 KB)

    Recovery from transients is imperative to maintain necessary system reliability in the face of transient errors which have been estimated to occur at a rate of 5 to 100 times that of permanent failures. Excessive delays associated with recovery become a problem when as much as 512 Kbytes of RAM in the faulty processor must be restored while maintaining full functionality of 40-100 Hz iterative con... View full abstract»

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  • Minimizing the number of late tasks with error constraint

    Publication Year: 1990, Page(s):32 - 40
    Cited by:  Papers (4)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (724 KB)

    The problem of minimizing the number of late tasks in the imprecise computation model is considered. Each task consists of two subtasks, mandatory and optional. A task is said to be on-time if its mandatory part is completed by its deadline; otherwise, it is said to be late. An on-time task incurs an error if its optional part is not computed by the deadline, and the error is simply the execution ... View full abstract»

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  • Language support for the Maruti real-time system

    Publication Year: 1990, Page(s):257 - 266
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (732 KB)

    Maruti is a testbed for the design of time-driven hard real-time systems. It uses the technique of prescheduling, where the application is scheduled prior to execution and resources required by the application are reserved, in order to ensure that deadlines are met. A description is given of the features of MPL, a language for Maruti. MPL provides constructs for expressing time constraints, preced... View full abstract»

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  • Fixed priority scheduling of periodic task sets with arbitrary deadlines

    Publication Year: 1990, Page(s):201 - 209
    Cited by:  Papers (257)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (616 KB)

    Consideration is given to the problem of fixed priority scheduling of period tasks with arbitrary deadlines. A general criterion for the schedulability of such a task set is given. Worst case bounds are given which generalize the C.L. Liu and J.W. Layland (1973) bound. The results are shown to provide a basis for developing predictable distributed real-time systems View full abstract»

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  • Agreeing on a leader in real-time [fault tolerant computer system]

    Publication Year: 1990, Page(s):166 - 172
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (568 KB)

    A method is devised for maintaining the continuing availability of a vital service in a real-time shared-memory multiprocessor fault-tolerant computer system. The essential characteristics of the service to be provided are given. The service can be correctly provided by any one operational processor acting alone. The job of selecting the processor to provide the service is the real-time leader ele... View full abstract»

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  • On-line routing of real-time messages

    Publication Year: 1990, Page(s):126 - 135
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (772 KB)

    Whether it is possible to have an optimal online algorithm for unidirectional ring, out-tree, in-tree, bidirectional tree, and bidirectional ring networks is discussed. The problem is considered under various restrictions of four parameters-origin node, destination node, release time and deadline. For unidirectional ring, it is shown that no such algorithm can exist unless one of the four paramete... View full abstract»

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  • Scalability of a distributed real-time resource counter

    Publication Year: 1990, Page(s):51 - 59
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (672 KB)

    The authors address the topic of how to meet a real-time constraint as the load on a distributed system increases, without increasing the capacity of the individual processors. The application studied is a real-time resource counter with a probabilistic correctness criterion, and is motivated by the problem of implementing resource management in the telephone network. They introduce a model that c... View full abstract»

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  • Experiments with a program timing tool based on source-level timing schema

    Publication Year: 1990, Page(s):72 - 81
    Cited by:  Papers (29)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (864 KB)

    A timing tool has been implemented for a subset of C as an initial experiment in validating a methodology for predicting the deterministic execution times of programs. The tool is based on formal timing schema that are defined for each source level construct (procedures, statements, expressions). The tool accepts a program and bounds for each loop, and produces predictions for best and worst case ... View full abstract»

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  • A proof system for communicating shared resources

    Publication Year: 1990, Page(s):288 - 299
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (824 KB)

    The authors introduce a proof system for CCSR, a process algebra based on the CSR model. CCSR allows the algebraic specifications of timeouts, interrupts, periodic behaviors and exceptions. A rigorous treatment of preemption, which is based not only on priority but also on resource utilization and inter-resource synchronization, is provided. The theory of preemption leads to a term equivalence bas... View full abstract»

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  • SMART (strategic memory allocation for real-time) cache design using the MIPS R3000

    Publication Year: 1990, Page(s):322 - 330
    Cited by:  Papers (33)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (828 KB)

    SMART, a technique for providing predictable cache performance for real-time systems with priority-based preemptive scheduling, is presented. The technique is implemented in a R3000 cache design. The value density acceleration (VDA) cache allocation algorithm is also introduced, and shown to be suitable for run-time cache allocation View full abstract»

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  • MRL: a real-time rule-based production system

    Publication Year: 1990, Page(s):267 - 276
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (720 KB)

    The response time analysis of rule-based expert systems is discussed. The rule-based production system MRL (macro-rule-based language) is introduced. MRL has been designed to facilitate more accurate analysis of the response times of programs while maintaining the flexibility and expressiveness of traditional production systems such as OPS5. Research on modular analysis of rule-based systems is de... View full abstract»

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