Proceedings 13th Euromicro Conference on Real-Time Systems

13-15 June 2001

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  • Proceedings 13th Euromicro Conference on Real-Time Systems

    Publication Year: 2001
    Request permission for commercial reuse | |PDF file iconPDF (163 KB)
    Freely Available from IEEE
  • A hyperbolic bound for the rate monotonic algorithm

    Publication Year: 2001, Page(s):59 - 66
    Cited by:  Papers (39)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (531 KB) | HTML iconHTML

    In this paper we propose a novel schedulability analysis for verifying the feasibility of large periodic task sets under the rate monotonic algorithm, when the exact test cannot be applied on line due to prohibitively long execution times. The proposed test has the same complexity as the original Liu and Layland bound but it is less pessimistic, so allowing to accept task sets that would be reject... View full abstract»

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  • Analysis of a simple model for non-preemptive blocking-free scheduling

    Publication Year: 2001
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (176 KB) | HTML iconHTML

    Non-preemptive scheduling is known for its lower efficiency in meeting temporal constraints when compared to preemptive scheduling. However, it is still used in certain cases such as in message scheduling over serial broadcast buses and in light multi-tasking kernels for embedded systems based on simple microprocessors. These cases are typically found in control applications requiring the periodic... View full abstract»

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  • Transformation of path information for WCET analysis during compilation

    Publication Year: 2001, Page(s):29 - 36
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (644 KB) | HTML iconHTML

    Performing worst-case execution time (WCET) analysis on machine code with program path annotation provided at high-level source code level requires the transformation of path annotations from the source-code level to assembly/object-code level. This path-information transformation can be done outside or integrated into the compiler during code compilation. The first approach is easier to implement... View full abstract»

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  • An effective schedulability analysis for fault-tolerant hard real-time systems

    Publication Year: 2001, Page(s):209 - 216
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (624 KB) | HTML iconHTML

    We propose worst-case response time schedulability analysis for fault-tolerant hard real-time systems which takes into account the effects of temporary faults. The major contribution of our approach is to consider the recovery of tasks running with higher priorities. This characteristic is very useful since faulty tasks certainly have a shorter period of time to meet their deadlines. Due to its fl... View full abstract»

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  • Memory and time-efficient schedulability analysis of task sets with stochastic execution time

    Publication Year: 2001, Page(s):19 - 26
    Cited by:  Papers (20)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (716 KB) | HTML iconHTML

    This paper presents an efficient way to analyse the performance of task sets, where the task execution time is specified as a generalized continuous probability distribution. We consider fixed task sets of periodic, possibly dependent, non-pre-emptable tasks with deadlines less than or equal to the period. Our method is not restricted to any specific scheduling policy and supports policies with bo... View full abstract»

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  • Three obstacles to flexible scheduling

    Publication Year: 2001, Page(s):11 - 18
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (596 KB) | HTML iconHTML

    The key to the next generation real-time systems is flexible scheduling mechanisms that guarantee hard deadlines and use available spare resources to maximise total system utility. This is a multicriteria scheduling problem. It is argued that common approaches like eager slack usage and mandatory first schemes are not only not optimal but nor adequate for a wide class of process models. It is also... View full abstract»

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  • A new kernel approach for modular real-time systems development

    Publication Year: 2001, Page(s):199 - 206
    Cited by:  Papers (38)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (648 KB) | HTML iconHTML

    This paper presents a dynamic configurable kernel architecture designed for supporting a simple implementation, integration and evaluation of scheduling algorithms. The main goal of the proposed architecture is to provide a platform for fast prototyping scheduling algorithms both for the CPU and for the devices. The kernel is fully modular in terms of scheduling policies, aperiodic servers, and co... View full abstract»

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  • MAST: Modeling and analysis suite for real time applications

    Publication Year: 2001, Page(s):125 - 134
    Cited by:  Papers (70)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (732 KB) | HTML iconHTML

    This paper describes a model for representing the temporal and logical elements of real-time applications, called MAST. This model allows a very rich description of the system, including the effects of event or message-based synchronization, multiprocessor and distributed architectures as well as shared resource synchronization. The model is directly obtainable from a description of the system des... View full abstract»

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  • A modular and retargetable framework for tree-based WCET analysis

    Publication Year: 2001, Page(s):37 - 44
    Cited by:  Papers (35)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (680 KB) | HTML iconHTML

    A fundamental requirement for hard real-time systems is the knowledge of tasks worst case execution times (WCET). Static worst-case execution time analysis (WCET analysis), thanks to the static analysis of a piece of source code, returns an upper bound of the time required to execute it on a given hardware. Taking into account modern architectural features makes it possible to determine tight WCET... View full abstract»

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  • Worst-case execution time analysis of the RTEMS real-time operating system

    Publication Year: 2001, Page(s):191 - 198
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (692 KB) | HTML iconHTML

    An important issue in building operating systems for hard real-time applications is to compute the worst-case execution times (WCET) of the operating system activities. Traditionally, this has been achieved by an exhaustive testing of the operating system, with a careful attention on the testing conditions to reproduce the worst-case execution scenario. In this paper we explore the alternative app... View full abstract»

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  • Offsets for scheduling mode changes

    Publication Year: 2001, Page(s):3 - 10
    Cited by:  Papers (3)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (624 KB) | HTML iconHTML

    In multi-moded real-time systems there may exist a different set of tasks per mode. During its mission, the system may switch to a new operating mode, which will involve completing running old-mode tasks and starting new-mode tasks. This represents a transient, bounded overload, which may not be schedulable unless some new-mode tasks are delayed until the old-mode load has decreased. Although this... View full abstract»

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  • Test generation for time critical systems: Tool and case study

    Publication Year: 2001, Page(s):155 - 162
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (596 KB) | HTML iconHTML

    Generating timed test sequences by hand is error-prone and time consuming, and it is easy to overlook important scenarios. The paper presents a tool based on formal methods that automatically computes a test suite for conformance testing of time critical systems. The generated tests are selected on the basis of a coverage criterion of the specification. The tool guarantees production of sound test... View full abstract»

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  • A new approach to the specification and verification of real-time systems

    Publication Year: 2001, Page(s):171 - 180
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (676 KB) | HTML iconHTML

    We present a new temporal logic for the specification and verification of real-time systems. This logic is defined on discrete time transition systems which are interpreted in an abstract manner instead of the usual stuttering interpretation. Our approach directly allows the abstraction of real-time systems by ignoring irrelevant qualitative properties, but without loosing any quantitative informa... View full abstract»

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  • Minimum and maximum utilization bounds for multiprocessor RM scheduling

    Publication Year: 2001, Page(s):67 - 75
    Cited by:  Papers (18)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (608 KB) | HTML iconHTML

    This paper deals with the problem of finding utilization bounds for multiprocessor rate monotonic scheduling with partitioning. The minimum and maximum utilization bounds among all the reasonable allocation algorithms are calculated. We prove that the utilization bound associated with the reasonable allocation heuristic Worst Fit (WF) is equal to that minimum. In addition, we prove that the utiliz... View full abstract»

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  • Timely use of the CAN protocol in critical hard real-time systems with faults

    Publication Year: 2001, Page(s):95 - 102
    Cited by:  Papers (22)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (568 KB) | HTML iconHTML

    The presence of network errors such as electrical interference affects the timing properties of a CAN (Controller Area Network) bus. In hard real-time systems it is often better to not receive a message than to receive it too late. Aborting late messages is a form of real-time error confinement which prevents late messages affecting the timeliness of other messages and processes. This can be used ... View full abstract»

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  • Real-time disk scheduling for block-stripping I2O RAID

    Publication Year: 2001, Page(s):217 - 224
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (644 KB) | HTML iconHTML

    The emergence of Intelligent I/O (I2O) architecture provides a standard for high-performance I/O subsystems and introduces intelligence at the hardware level. With an embedded processor, I2O adaptors can offload the major I/O processing workload from the CPU and, at the same time, increase the I/O performance. This paper addresses the essential issue in the design of disk scheduling for I2O RAID-0... View full abstract»

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  • WCET analysis of reusable portable code

    Publication Year: 2001, Page(s):45 - 52
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (668 KB) | HTML iconHTML

    Traditional worst-case execution-time analysis (WCET analysis) computes upper bounds for the execution times of code. This analysis uses knowledge about the execution contest of the code and about the target architecture. In contrast, the WCET analysis for reusable and portable code has to abstract from parameters that are unknown until the code is finally used. The analysis is done in two steps. ... View full abstract»

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  • Predictable and efficient virtual addressing for safety-critical real-time systems

    Publication Year: 2001, Page(s):183 - 190
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (660 KB) | HTML iconHTML

    Conventionally, the use of virtual memory in safety-critical real-time systems has been avoided, one reason being the difficulties it provides to timing analysis. The difficulties arise due to the Memory Management Unit (MMU) on commercial processors being optimised to improve average performance, to the detriment of simple worst-case analysis. However within safety-critical systems, there is a mo... View full abstract»

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  • A synchronous model of IEC 61131 PLC languages in SIGNAL

    Publication Year: 2001, Page(s):135 - 142
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (672 KB) | HTML iconHTML

    Control systems for industrial automation feature real-time programs embedded in a variety of machines and processes, showing complexity and safety criticality. Standardization has led to the definition of the IEC 61131 design standard for Programmable Logic Controllers (PLCs). Its formalization for purposes of analysis and design tool support is an active research topic. The synchronous approach ... View full abstract»

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  • Determining optimal processor speeds for periodic real-time tasks with different power characteristics

    Publication Year: 2001, Page(s):225 - 232
    Cited by:  Papers (87)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (428 KB) | HTML iconHTML

    In this paper, we provide an efficient solution for periodic real-time tasks with (potentially) different power consumption characteristics. We show that a task Ti can run at a constant speed Si at every instance without hurting optimality. We sketch an O(n2 log n) algorithm to compute the optimal Si values. We also prove that the EDF (Earliest Deadline ... View full abstract»

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  • Partitioning of hierarchical automation systems

    Publication Year: 2001, Page(s):143 - 152
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (860 KB) | HTML iconHTML

    The research described concerns the partitioning of large control applications for a multi-computer system in order to meet plant localization requirements and to exploit parallelism. The considered applications have hierarchical structure and are composed by a network of automata. Our application domain is the automation of power stations and electricity distribution. Because of strong EM noise i... View full abstract»

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  • MSC+: From requirement to prototyped systems

    Publication Year: 2001, Page(s):117 - 124
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (684 KB) | HTML iconHTML

    Message Sequence Charts (MSCs) have gained wide acceptance for scenario-based specification of component behaviors. MSCs are very useful during requirements capture phase of the software development process and reveal errors in requirement specifications when used in early stages. As MSCs have found widespread usage, there have been several extensions to overcome its' shortcomings for a spectrum o... View full abstract»

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  • Mixed Pfair/ERfair scheduling of asynchronous periodic tasks

    Publication Year: 2001, Page(s):76 - 85
    Cited by:  Papers (29)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (732 KB) | HTML iconHTML

    In this paper, we prove that a simplified variant of the PD Pfair algorithm, called PD2, is optimal for scheduling any mix of early-release and non-early-release asynchronous tasks on a multiprocessor. This result breaks new ground by incorporating both early-release and non-early-release tasks under a common framework. In addition, all prior work on optimal multiprocessor Pfair schedul... View full abstract»

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  • Timing analysis of reliable real-time communication in CAN networks

    Publication Year: 2001, Page(s):103 - 114
    Cited by:  Papers (8)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (872 KB) | HTML iconHTML

    The Controller Area Network (CAN) is a fieldbus network with real-time capabilities. It is generally considered that CAN guarantees atomic multicast properties, through its extensive error detection/signalling mechanisms. However, there are error situations where messages can be delivered in duplicate by some receivers or delivered only by a subset of the receivers, leading to inconsistencies in t... View full abstract»

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