Download or read book Scheduling Slack Time in Fixed Priority Pre emptive Systems written by R. I. Davis and published by . This book was released on 1993 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "This report addresses the problem of jointly scheduling tasks with both hard and soft time constraints. We present new analysis which builds upon previous research into slack stealing algorithms. Our analysis determines the maximum processing time which may be stolen from hard deadline periodic or sporadic tasks, without jeopardising their timing constraints. It extends to tasks with characteristics such as synchronisation, release jitter and stochastic execution times, as well as forming the basis for research into optimal and approximate slack stealing algorithms."

Download or read book Approximate Slack Stealing Algorithms for Fixed Priority Pre Emptive Systems written by R. I. Davis and published by . This book was released on 1993 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "Recent research into the problem of jointly scheduling tasks with both hard and soft time constraints has focused on the development of optimal slack stealing algorithms. Theoretically, these optimal algorithms offer significant performance improvements over previous bandwidth preserving algorithms such as the Sporadic Server or Extended Priority Exchange algorithm. However, there are problems associated with the practical application of both static and dynamic variants of optimal slack stealing algorithms. In this report, we address these problems by providing approximate slack stealing algorithms which offer close to optimal performance with practical utility."

Download or read book Aperiodic Request Scheduling in Fixed priority Preemptive Systems written by Too-Seng Tia and published by . This book was released on 1994 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "In this report, we investigate the problem of scheduling aperiodic requests in systems where periodic tasks are scheduled on a fixed-priority, preemptive basis. First, we show that given any queueing discipline for the aperiodic requests, no scheduling algorithm can minimize the response time of every aperiodic request and guarantee that the deadlines of the periodic tasks are met when the periodic tasks are scheduled on fixed-priority, preemptive basis. We then develop two algorithms: Algorithm L is locally optimal in that it minimizes the response time of the aperiodic request at the head of the aperiodic service queue. Algorithm G is globally optimal in that it completes the current backlog of work in the aperiodic service queue as early as possible. Algorithm G also tries to reduce the average response time of the aperiodic requests."

Download or read book Utilizing Slack Time for Aperiodic and Sporadic Requests Scheduling in Real time Systems written by Too-Seng Tia and published by . This book was released on 1995 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "A real-time system typically has a mixture of periodic and aperiodic workload. Requests in each periodic task have regular arrival times and hard deadlines. Aperiodic requests, on the other hand, have random arrival times and may have hard or soft deadlines. We called these aperiodic requests with hard deadlines sporadic requests and those with soft deadlines aperiodic requests. This thesis extends two common approaches to scheduling periodic requests to address the problems of jointly scheduling periodic requests with aperiodic requests or sporadic requests. Specifically, we present algorithms for scheduling aperiodic requests in dynamic-priority systems, sporadic requests in dynmaic-priority systems, and aperiodic requests in fixed-priority systems. Our algorithms are based on the concept of slack, which is the amount of processor time available to schedule the aperiodic or sporadic requests without causing any periodic requests to miss their deadlines. Two features that distinguish our algorithms from previous slack stealing algorithms proposed in the literature are (1) the efficient computation of slack, and (2) the optimal usage (i.e., when and how much to use) of the available slack to schedule the aperiodic or sporadic requests. For aperiodic requests, our algorithms are optimal in that the aperiodic requests have the minimum possible response times. For sporadic requests, they guarantee the deadlines of as many sporadic requests as possible."

Download or read book Deadline Scheduling for Real Time Systems written by John A. Stankovic and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many real-time systems rely on static scheduling algorithms. This includes cyclic scheduling, rate monotonic scheduling and fixed schedules created by off-line scheduling techniques such as dynamic programming, heuristic search, and simulated annealing. However, for many real-time systems, static scheduling algorithms are quite restrictive and inflexible. For example, highly automated agile manufacturing, command, control and communications, and distributed real-time multimedia applications all operate over long lifetimes and in highly non-deterministic environments. Dynamic real-time scheduling algorithms are more appropriate for these systems and are used in such systems. Many of these algorithms are based on earliest deadline first (EDF) policies. There exists a wealth of literature on EDF-based scheduling with many extensions to deal with sophisticated issues such as precedence constraints, resource requirements, system overload, multi-processors, and distributed systems. Deadline Scheduling for Real-Time Systems: EDF and Related Algorithms aims at collecting a significant body of knowledge on EDF scheduling for real-time systems, but it does not try to be all-inclusive (the literature is too extensive). The book primarily presents the algorithms and associated analysis, but guidelines, rules, and implementation considerations are also discussed, especially for the more complicated situations where mathematical analysis is difficult. In general, it is very difficult to codify and taxonomize scheduling knowledge because there are many performance metrics, task characteristics, and system configurations. Also, adding to the complexity is the fact that a variety of algorithms have been designed for different combinations of these considerations. In spite of the recent advances there are still gaps in the solution space and there is a need to integrate the available solutions. For example, a list of issues to consider includes: preemptive versus non-preemptive tasks, uni-processors versus multi-processors, using EDF at dispatch time versus EDF-based planning, precedence constraints among tasks, resource constraints, periodic versus aperiodic versus sporadic tasks, scheduling during overload, fault tolerance requirements, and providing guarantees and levels of guarantees (meeting quality of service requirements). Deadline Scheduling for Real-Time Systems: EDF and Related Algorithms should be of interest to researchers, real-time system designers, and instructors and students, either as a focussed course on deadline-based scheduling for real-time systems, or, more likely, as part of a more general course on real-time computing. The book serves as an invaluable reference in this fast-moving field.

Download or read book Hard Real Time Computing Systems written by Giorgio C Buttazzo and published by Springer Science & Business Media. This book was released on 2011-09-10 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This updated edition offers an indispensable exposition on real-time computing, with particular emphasis on predictable scheduling algorithms. It introduces the fundamental concepts of real-time computing, demonstrates the most significant results in the field, and provides the essential methodologies for designing predictable computing systems used to support time-critical control applications. Along with an in-depth guide to the available approaches for the implementation and analysis of real-time applications, this revised edition contains a close examination of recent developments in real-time systems, including limited preemptive scheduling, resource reservation techniques, overload handling algorithms, and adaptive scheduling techniques. This volume serves as a fundamental advanced-level textbook. Each chapter provides basic concepts, which are followed by algorithms, illustrated with concrete examples, figures and tables. Exercises and solutions are provided to enhance self-study, making this an excellent reference for those interested in real-time computing for designing and/or developing predictable control applications.

Download or read book Integrating Best effort Policies Into Hard Real time Systems Based on Fixed Priority Pre emptive Scheduling written by R. I. Davis and published by . This book was released on 1994 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "Analysis is provided for fixed priority pre-emptive scheduling enables a priori guarantees to be given regarding the timing requirements of critical tasks. By comparison, Best-Effort scheduling maximises system utility, but at best provides only probabilistic guarantees that time constraints will be met. In this paper, we show how these two schemes can be integrated. A new Adaptive Value-Density Threshold policy is introduced which approximates the Best-Effort policy but incurs much lower overheads. This policy is used to admit optional (utility enhancing) tasks for on-line acceptance testing. If guaranteed such components are assigned a fixed priority and executed when no higher priority tasks are runnable. This approach combines the benefits of guaranteeing hard requirements with increased system utility, resilience to software failures and increased application robustness."

Download or read book Imprecise and Approximate Computation written by Swaminathan Natarajan and published by Springer. This book was released on 2007-08-26 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real-time systems are now used in a wide variety of applications. Conventionally, they were configured at design to perform a given set of tasks and could not readily adapt to dynamic situations. The concept of imprecise and approximate computation has emerged as a promising approach to providing scheduling flexibility and enhanced dependability in dynamic real-time systems. The concept can be utilized in a wide variety of applications, including signal processing, machine vision, databases, networking, etc. For those who wish to build dynamic real-time systems which must deal safely with resource unavailability while continuing to operate, leading to situations where computations may not be carried through to completion, the techniques of imprecise and approximate computation facilitate the generation of partial results that may enable the system to operate safely and avert catastrophe. Audience: Of special interest to researchers. May be used as a supplementary text in courses on real-time systems.

Download or read book Hard Real Time Computing Systems written by Giorgio Buttazzo and published by Springer Nature. This book was released on with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Parallel and Distributed Processing and Applications written by Jiannong Cao and published by Springer Science & Business Media. This book was released on 2004-12-02 with total page 1080 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the Second International Symposium on Parallel and Distributed Processing and Applications, ISPA 2004, held in Hong Kong, China in December 2004. The 78 revised full papers and 38 revised short papers presented were carefully reviewed and selected from 361 submissions. The papers are organized in topical sections on parallel algorithms and systems, data mining and management, distributed algorithms and systems, fault tolerance protocols and systems, sensor networks and protocols, cluster systems, grid applications and systems, peer-to-peer and ad hoc networking, grid scheduling and algorithms, data replication and caching, software engineering and testing, grid protocols, context-aware and mobile computing, distributed routing and switching protocols, cluster resource scheduling and algorithms, security, high performance processing, networking and protocols, artificial intelligence systems, hardware architecture and implementations, high performance computing architecture, and distributed systems architecture.

Download or read book Real Time and Embedded Computing Systems and Applications written by Jing Chen and published by Springer. This book was released on 2004-04-08 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the 37 papers presented at the 9th International Con- rence on Real-Time and Embedded Computing Systems and Applications (RT- CSA 2003). RTCSA is an international conference organized for scientists and researchers from both academia and industry to hold intensive discussions on advancing technologies topics on real-time systems, embedded systems, ubiq- tous/pervasive computing, and related topics. RTCSA 2003 was held at the Department of Electrical Engineering of National Cheng Kung University in Taiwan. Paper submissions were well distributed over the various aspects of real-time computing and embedded system technologies. There were more than 100 participants from all over the world. The papers, including 28 regular papers and 9 short papers are grouped into thecategoriesofscheduling,networkingandcommunication,embeddedsystems, pervasive/ubiquitous computing, systems and architectures, resource mana- ment, ?le systems and databases, performance analysis, and tools and de- lopment. The grouping is basically in accordance with the conference program. Earlier versions of these papers were published in the conference proceedings. However, some papers in this volume have been modi?ed or improved by the authors, in various aspects, based on comments and feedback received at the conference. It is our sincere hope that researchers and developers will bene?t from these papers. We would like to thank all the authors of the papers for their contribution. We thank the members of the program committee and the reviewers for their excellent work in evaluating the submissions. We are also very grateful to all the members of the organizing committees for their help, guidance and support.

Download or read book Languages Compilers and Tools for Embedded Systems written by Frank Mueller and published by Springer Science & Business Media. This book was released on 1998 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the strictly refereed post-workshop proceedings of the ACM SIGPLAN Workshop on Languages, Compilers, and Tools for Embedded Systems, LCTES '98, held in Montreal, Canada, in June 1998. The 19 revised papers presented were carefully reviewed and selected from a total of 54 submissions for inclusion in the book; also included are one full paper and an abstract of an invited contribution. The papers address all current aspects of research and development in the rapidly growing area of embedded systems and real-time computing.

Download or read book DSP Software Development Techniques for Embedded and Real Time Systems written by Robert Oshana and published by Elsevier. This book was released on 2006-01-09 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: Today's embedded and real-time systems contain a mix of processor types: off-the-shelf microcontrollers, digital signal processors (DSPs), and custom processors. The decreasing cost of DSPs has made these sophisticated chips very attractive for a number of embedded and real-time applications, including automotive, telecommunications, medical imaging, and many others—including even some games and home appliances. However, developing embedded and real-time DSP applications is a complex task influenced by many parameters and issues. DSP Software Development Techniques for Embedded and Real-Time Systems is an introduction to DSP software development for embedded and real-time developers giving details on how to use digital signal processors efficiently in embedded and real-time systems. The book covers software and firmware design principles, from processor architectures and basic theory to the selection of appropriate languages and basic algorithms. The reader will find practical guidelines, diagrammed techniques, tool descriptions, and code templates for developing and optimizing DSP software and firmware. The book also covers integrating and testing DSP systems as well as managing the DSP development effort. - Digital signal processors (DSPs) are the future of microchips! - Includes practical guidelines, diagrammed techniques, tool descriptions, and code templates to aid in the development and optimization of DSP software and firmware

Download or read book Network and Parallel Computing written by Jian Cao and published by Springer Science & Business Media. This book was released on 2008-10-07 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the IFIP International Conference on Network and Parallel Computing, NPC 2008, held in Shanghai, China in October 2008. The 32 revised full papers presented were carefully selected from over 140 submissions. The papers are organized in topical sections on network technologies; network applications; network and parallel architectures; parallel and distributed software.

Download or read book Setting Knowledge Free The Journal of Issues in Informing Science and Information Technology Volume 5 2008 written by Eli Cohen and published by Informing Science. This book was released on with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Systematic Methodology for Real Time Cost Effective Mapping of Dynamic Concurrent Task Based Systems on Heterogenous Platforms written by Zhe Ma and published by Springer Science & Business Media. This book was released on 2007-08-26 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: A genuinely useful text that gives an overview of the state-of-the-art in system-level design trade-off explorations for concurrent tasks running on embedded heterogeneous multiple processors. The targeted application domain covers complex embedded real-time multi-media and communication applications. This material is mainly based on research at IMEC and its international university network partners in this area over the last decade. In all, the material those in the digital signal processing industry will find here is bang up-to-date.

Download or read book Techniques for Building Timing Predictable Embedded Systems written by Nan Guan and published by Springer. This book was released on 2016-02-03 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes state-of-the-art techniques for designing real-time computer systems. The author shows how to estimate precisely the effect of cache architecture on the execution time of a program, how to dispatch workload on multicore processors to optimize resources, while meeting deadline constraints, and how to use closed-form mathematical approaches to characterize highly variable workloads and their interaction in a networked environment. Readers will learn how to deal with unpredictable timing behaviors of computer systems on different levels of system granularity and abstraction.