The Experts below are selected from a list of 48138 Experts worldwide ranked by ideXlab platform
Lili Tan - One of the best experts on this subject based on the ideXlab platform.
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The Worst-Case Execution Time tool challenge 2006
International Journal on Software Tools for Technology Transfer, 2009Co-Authors: Lili TanAbstract:The first international Worst-Case Execution Time (WCET) Tool Challenge in 2006 used benchmark programs to evaluate academic and commercial WCET tools. It aimed to study the state-of-the-art in WCET analysis. The WCET Tool Challenge comprised two parallel evaluation approaches: an internal evaluation by the respective tool developers and an external test by a neutral person of an independent institute. The latter was conducted by the author of this paper. Focusing on the external test, we describe the rules, benchmarks, participants and discuss the obtained results.
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the worst case Execution Time tool challenge 2006 the external test
Leveraging Applications of Formal Methods, 2006Co-Authors: Lili TanAbstract:The first worst case Execution Time (WCET) tool challenge, performed in 2006, attempted to evaluate the state-of- the-art in timing analysis for real-Time systems and so to encourage research and activities in the WCET community. It applied two evaluation approaches to the tools submitted, self-evaluation and external evaluation. In order to balance users' effects and to achieve a comparable evaluation, an independent test person has been assigned by the WCET Challenge Working Group to perform the external tool evaluation. The test person visited the tool developers and evaluated the tools entered. This paper describes the testing procedures applied, the results obtained, and the evaluation made in the Challenge.
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ISoLA - The Worst Case Execution Time Tool Challenge 2006: The External Test
Second International Symposium on Leveraging Applications of Formal Methods Verification and Validation (isola 2006), 2006Co-Authors: Lili TanAbstract:The first worst case Execution Time (WCET) tool challenge, performed in 2006, attempted to evaluate the state-of- the-art in timing analysis for real-Time systems and so to encourage research and activities in the WCET community. It applied two evaluation approaches to the tools submitted, self-evaluation and external evaluation. In order to balance users' effects and to achieve a comparable evaluation, an independent test person has been assigned by the WCET Challenge Working Group to perform the external tool evaluation. The test person visited the tool developers and evaluated the tools entered. This paper describes the testing procedures applied, the results obtained, and the evaluation made in the Challenge.
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the worst case Execution Time tool challenge 2006 technical report for the external test
2006Co-Authors: Lili TanAbstract:The first Worst Case Execution Time WCET Tool Challenge, performed in 2006, attempted to evalu- ate the state-of-the-art in timing analysis for real-Time systems and to encourage research and activities in the WCET community. The challenge assesses academic and commercial WCET tools. It comprises two approaches: self-evaluation by the respective tool developers and ex- ternal evaluation by an independent and neutral test per- son. During the evaluation period, the test person visited the tool developers to test the tools and to perform mea- surements on-site. This paper describes the procedure and the results of the external evaluation.
Raimund Kirner - One of the best experts on this subject based on the ideXlab platform.
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Fast, Interactive Worst-Case Execution Time Analysis With Back-Annotation
IEEE Transactions on Industrial Informatics, 2012Co-Authors: T. Harmon, Raimund Kirner, Martin Schoeberl, R. Klefstad, K. H. K. Kim, M. R. LowryAbstract:For hard real-Time systems, static code analysis is needed to derive a safe bound on the Worst-Case Execution Time (WCET). Virtually all prior work has focused on the accuracy of WCET analysis without regard to the speed of analysis. The resulting algorithms are often too slow to be integrated into the development cycle, requiring WCET analysis to be postponed until a final verification phase. In this paper, we propose interactive WCET analysis as a new method to provide near-instantaneous WCET feedback to the developer during software programming. We show that interactive WCET analysis is feasible using tree-based WCET calculation. The feedback is realized with a plugin for the Java editor jEdit, where the WCET values are back-annotated to the Java source at the statement level. Comparison of this tree-based approach with the implicit path enumeration technique (IPET) shows that tree-based analysis scales better with respect to program size and gives similar WCET values.
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RTCSA (1) - Context-Sensitive Measurement-Based Worst-Case Execution Time Estimation
2011 IEEE 17th International Conference on Embedded and Real-Time Computing Systems and Applications, 2011Co-Authors: Michael Zolda, Sven Bünte, Raimund KirnerAbstract:The goal of measurement-based WCET estimation (MBWE) is to derive an estimate of the Worst-Case Execution Time (WCET) of a given piece of software on a particular target platform by executing the software on the target hardware and analyzing the obtained Time-stamped Execution traces. In this paper we introduce context-sensitive MBWE, an approach that can reduce pessimism by making use of state information that is exposed through individual control-flow decisions. We show how to extend the popular IPET method, to obtain tighter WCET estimates. We provide confirmative empirical results that demonstrate the effectiveness of our approach.
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ISORC - Obstacles in Worst-Case Execution Time Analysis
2008 11th IEEE International Symposium on Object and Component-Oriented Real-Time Distributed Computing (ISORC), 2008Co-Authors: Raimund Kirner, Peter PuschnerAbstract:The analysis of the Worst-Case Execution Time (WCET) requires detailed knowledge of the program behavior. In practice it is still not possible to obtain all needed information automatically. In this paper we present the current state of the art of WCET analysis and point to the main problems to be solved. The most eminent problem is the state problem, i.e., the precise determination of possible processor states at different program locations. The path problem refers to the fact that current tools are not able to calculate all (in)feasible paths automatically. We discuss how the main open problems manifest themselves in static and in measurement-based WCET analysis methods.
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WCET - WCET 2008 Abstracts Collection - 8th Intl. Workshop on Worst-Case Execution Time (WCET) Analysis.
2008Co-Authors: Raimund KirnerAbstract:The workshop on Worst-Case Execution Time Analysis is a satellite event to the annual Euromicro Conference on Real-Time Systems. It brings together people that are interested in all aspects of timing analysis for real-Time systems. In the 2008 edition, 13 papers were presented, organized into four sessions: methods for WCET computation, low-level analysis, system-level analysis and flow-analysis. The workshop was also the opportunity to report from the 2007 WCET tool challenge.
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DAC - Modeling the function cache for Worst-Case Execution Time analysis
Proceedings of the 44th annual conference on Design automation - DAC '07, 2007Co-Authors: Raimund Kirner, Martin SchoeberlAbstract:Static Worst-Case Execution Time (WCET) analysis is done by modeling the hardware behavior. In this paper we describe a WCET analysis technique to analyze systems with function caches, a special kind of instruction cache that caches whole functions only. This cache was designed with the aim to be more predictable for the Worst-Case than existing instruction caches. Within this paper we developed a cache analysis technique for the function cache. One of the new concepts of this analysis technique is the local persistence analysis, which allows to precisely model the function cache.
Martin Schoeberl - One of the best experts on this subject based on the ideXlab platform.
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taclebench a benchmark collection to support worst case Execution Time research
Worst-Case Execution Time Analysis, 2016Co-Authors: Heiko Falk, Wolfgang Puffitsch, Björn Lisper, Martin Schoeberl, Sebastian Altmeyer, Peter Hellinckx, Christine Rochange, Rasmus Bo Sorensen, Peter Wagemann, Simon WegenerAbstract:Engineering related research, such as research on Worst-Case Execution Time, uses experimentation to evaluate ideas. For these experiments we need example programs. Furthermore, to make the research experimentation repeatable those programs shall be made publicly available. We collected open-source programs, adapted them to a common coding style, and provide the collection in open-source. The benchmark collection is called TACLeBench and is available from GitHub in version 1.9 at the publication date of this paper. One of the main features of TACLeBench is that all programs are self-contained without any dependencies on standard libraries or an operating system.
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TACLeBench: A Benchmark Collection to Support Worst-Case Execution Time Research
2016Co-Authors: Heiko Falk, Wolfgang Puffitsch, Björn Lisper, Martin Schoeberl, Sebastian Altmeyer, Peter Hellinckx, Christine Rochange, Rasmus Bo Sorensen, Peter Wagemann, Simon WegenerAbstract:Engineering related research, such as research on Worst-Case Execution Time, uses experimentation to evaluate ideas. For these experiments we need example programs. Furthermore, to make the research experimentation repeatable those programs shall be made publicly available. We collected open-source programs, adapted them to a common coding style, and provide the collection in open-source. The benchmark collection is called TACLeBench and is available from GitHub in version 1.9 at the publication date of this paper. One of the main features of TACLeBench is that all programs are self-contained without any dependencies on standard libraries or an operating system. 1998 ACM Subject Classification C.3 [Special-Purpose and Application-Based Systems] Real-Time and Embedded Systems
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WCET - TACLeBench: a benchmark collection to support Worst-Case Execution Time research
2016Co-Authors: Heiko Falk, Wolfgang Puffitsch, Björn Lisper, Martin Schoeberl, Sebastian Altmeyer, Peter Hellinckx, Christine Rochange, Rasmus Bo Sorensen, Peter Wagemann, Simon WegenerAbstract:Engineering related research, such as research on Worst-Case Execution Time, uses experimentation to evaluate ideas. For these experiments we need example programs. Furthermore, to make the research experimentation repeatable those programs shall be made publicly available. We collected open-source programs, adapted them to a common coding style, and provide the collection in open-source. The benchmark collection is called TACLeBench and is available from GitHub in version 1.9 at the publication date of this paper. One of the main features of TACLeBench is that all programs are self-contained without any dependencies on standard libraries or an operating system.
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Fast, Interactive Worst-Case Execution Time Analysis With Back-Annotation
IEEE Transactions on Industrial Informatics, 2012Co-Authors: T. Harmon, Raimund Kirner, Martin Schoeberl, R. Klefstad, K. H. K. Kim, M. R. LowryAbstract:For hard real-Time systems, static code analysis is needed to derive a safe bound on the Worst-Case Execution Time (WCET). Virtually all prior work has focused on the accuracy of WCET analysis without regard to the speed of analysis. The resulting algorithms are often too slow to be integrated into the development cycle, requiring WCET analysis to be postponed until a final verification phase. In this paper, we propose interactive WCET analysis as a new method to provide near-instantaneous WCET feedback to the developer during software programming. We show that interactive WCET analysis is feasible using tree-based WCET calculation. The feedback is realized with a plugin for the Java editor jEdit, where the WCET values are back-annotated to the Java source at the statement level. Comparison of this tree-based approach with the implicit path enumeration technique (IPET) shows that tree-based analysis scales better with respect to program size and gives similar WCET values.
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ISORC - Worst-Case Execution Time Based Optimization of Real-Time Java Programs
2012 IEEE 15th International Symposium on Object Component Service-Oriented Real-Time Distributed Computing, 2012Co-Authors: Stefan Hepp, Martin SchoeberlAbstract:Standard compilers optimize Execution Time for the average case. However, in hard real-Time systems the Worst-Case Execution Time (WCET) is of primary importance. Therefore, a compiler for real-Time systems shall include optimizations that aim to minimize the WCET. One effective compiler optimization is method in lining. It is especially important for languages, like Java, where small setter and getter methods are considered good programming style. In this paper we present and explore WCET driven in lining of Java methods. We use the WCET analysis tool for the Java processor JOP to guide to optimization along the Worst-Case path. The tool JCopter is integrated with the WCET analysis tool and is used to explore different in lining strategies. On real-Time benchmarks the optimization results in a reduction of the WCET by a few percent up to a factor of about 2.
Andreas Ermedahl - One of the best experts on this subject based on the ideXlab platform.
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ECRTS - Deriving the Worst-Case Execution Time Input Values
2009 21st Euromicro Conference on Real-Time Systems, 2009Co-Authors: Andreas Ermedahl, Jan Gustafsson, Johan Fredriksson, Peter AltenberndAbstract:Worst-Case Execution Time (WCET) analysis derives upper bounds for Execution Times of programs. Such bounds are crucial when designing and verifying real-Time systems. A major problem with today’s WCET analysis approaches is that there is no feedback on the particular values of the input variables that cause the program’s WCET. However, this is important information for the real-Time system developer.We present a novel approach to overcome this problem. In particular, we present a method, based on a combination of input sensitive static WCET analysis and systematic search over the value space of the input variables, to derive the input value combination that causes the WCET. We also present several different approaches to speed up the search. Our evaluations show that the WCET input values can be relatively quickly derived for many type of programs, even for program with large input value spaces. We also show that the WCET estimates derived using the WCET input values often are much tighter than the WCET estimates derived when all possible input value combinations are taken into account.
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Clustered Worst-Case Execution-Time calculation
IEEE Transactions on Computers, 2005Co-Authors: Andreas Ermedahl, Friedhelm Stappert, Jakob EngblomAbstract:Knowing the Worst-Case Execution Time (WCET) of a program is necessary when designing and verifying real-Time systems. A correct WCET analysis method must take into account the possible program flow, such as loop iterations and function calls, as well as the timing effects of different hardware features, such as caches and pipelines. A critical part of WCET analysis is the calculation, which combines flow information and hardware timing information in order to calculate a program WCET estimate. The type of flow information which a calculation method can take into account highly determines the WCET estimate precision obtainable. Traditionally, we have had a choice between precise methods that perform global calculations with a risk of high computational complexity and local methods that are fast but cannot take into account all types of flow information. This paper presents an innovative hybrid method to handle complex flows with low computational complexity, but still generate safe and tight WCET estimates. The method uses flow information to find the smallest parts of a program that have to be handled as a unit to ensure precision. These units are used to calculate a program WCET estimate in a demand-driven bottom-up manner. The calculation method to use for a unit is not fixed, but could depend on the included flow and program characteristics.
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Worst-Case Execution Time Analysis of Disable Interrupt Regions in a Commercial Real-Time Operating System
2002Co-Authors: Martin Carlsson, Jakob Engblom, Andreas Ermedahl, Jan Lindblad, Björn LisperAbstract:Worst-Case Execution Time Analysis of Disable Interrupt Regions in a Commercial Real-Time Operating System
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Validating a Worst-Case Execution Time Analysis Method for an Embedded Processor
2001Co-Authors: Jakob Engblom, Andreas Ermedahl, Stappert FriedhelmAbstract:Knowing the Worst-Case Execution Time (WCET) of a program is necessary when designing and verifying real-Time systems. When evaluating WCET analysis methods, the common methodology is to compare a WCET estimate with an Execution of the same program
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A Worst-Case Execution-Time Analysis Tool Prototype for Embedded Real-Time Systems
2001Co-Authors: Jakob Engblom, Andreas Ermedahl, Friedhelm StappertAbstract:This paper gives an overview of the Worst-Case Execution Time (WCET) analysis research performed by the WCET group at Uppsala University, Sweden, in cooperation with C-LAB in Paderborn, Germany. ...
Thomas Ringler - One of the best experts on this subject based on the ideXlab platform.
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Static Worst-Case Execution Time analysis of synchronous programs
Lecture Notes in Computer Science, 2000Co-Authors: Thomas RinglerAbstract:In this paper a Worst-Case Execution Time (WCET) analysis of programs written in synchronous programming languages like ESTEREL is presented. Synchronous languages allow the building of deterministic systems and additionally enable formal verification techniques to be applied. Executable programs can behave synchronously if they fulfill certain temporal requirements. Therefore Worst-Case Execution Time analysis has to be applied to the programs generated by the synchronous language development environment. The paper gives a short overview about existing static Worst-Case Execution Time approaches and discusses the problems to be addressed by WCET analysis of synchronous programs. A concept for static analysis on a high level of abstraction is proposed. The concept is evaluated by means of a steer-by-wire demonstrator.
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Ada-Europe - Static Worst-Case Execution Time Analysis of Synchronous Programs
Reliable Software Technologies Ada-Europe 2000, 2000Co-Authors: Thomas RinglerAbstract:In this paper a Worst-Case Execution Time (WCET) analysis of programs written in synchronous programming languages like ESTEREL is presented. Synchronous languages allow the building of deterministic systems and additionally enable formal verification techniques to be applied. Executable programs can behave synchronously if they fulfill certain temporal requirements. Therefore Worst-Case Execution Time analysis has to be applied to the programs generated by the synchronous language development environment. The paper gives a short overview about existing static Worst-Case Execution Time approaches and discusses the problems to be addressed by WCET analysis of synchronous programs. A concept for static analysis on a high level of abstraction is proposed. The concept is evaluated by means of a steer-by-wire demonstrator.
