The complexity of computer systems in many application areas has increased rapidly in the last decade. In order to deal with this complexity, application programs should be constructed by layering reusable modules. Therefore, an object-based design and implementation methodology is advocated. In addition, dependability of these computer systems is very important, and thus timeliness has to be guaranteed. In this paper, a pre-run-time scheduling approach is proposed to guarantee timeliness for computer systems in an almost fully predictable environment and in the presence of faults. The advantages of pre-run-time scheduling over other strategies to guarantee timeliness are discussed. The approach is used to schedule applications with a novel combination of timing and functional constraints. In addition, a novel characteristic of the approach is the enhancement of inherent parallelism of an application in order to find a schedule.<>
{"title":"Pre-run-time scheduling for object-based, concurrent, real-time applications","authors":"J. Verhoosel, D. Hammer, Guohui Yu, L. Welch","doi":"10.1109/RTA.1994.316132","DOIUrl":"https://doi.org/10.1109/RTA.1994.316132","url":null,"abstract":"The complexity of computer systems in many application areas has increased rapidly in the last decade. In order to deal with this complexity, application programs should be constructed by layering reusable modules. Therefore, an object-based design and implementation methodology is advocated. In addition, dependability of these computer systems is very important, and thus timeliness has to be guaranteed. In this paper, a pre-run-time scheduling approach is proposed to guarantee timeliness for computer systems in an almost fully predictable environment and in the presence of faults. The advantages of pre-run-time scheduling over other strategies to guarantee timeliness are discussed. The approach is used to schedule applications with a novel combination of timing and functional constraints. In addition, a novel characteristic of the approach is the enhancement of inherent parallelism of an application in order to find a schedule.<<ETX>>","PeriodicalId":399167,"journal":{"name":"Proceedings of 2nd IEEE Workshop on Real-Time Applications","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116825103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Database systems for real-time applications must satisfy timing constraints associated with transactions, in addition to maintaining data consistency. Recently, interests in object-oriented databases have been growing for non-traditional applications of database systems, and several real-time applications are being developed using an object-oriented paradigm. The object-oriented approach seems promising for developing complex real-time database applications. However, it is not clear whether object-oriented database systems would be superior than relational database systems for supporting real-time applications. In this paper, we address issues that must be investigated in order to design and develop an object-oriented database system for real-time applications. Also, we present a model that integrates features for scheduling real-time transactions with the traditional object-oriented database model.<>
{"title":"Issues in developing object-oriented database systems for real-time applications","authors":"Juhnyoung Lee, S. Son, Myung-Joon Lee","doi":"10.1109/RTA.1994.316160","DOIUrl":"https://doi.org/10.1109/RTA.1994.316160","url":null,"abstract":"Database systems for real-time applications must satisfy timing constraints associated with transactions, in addition to maintaining data consistency. Recently, interests in object-oriented databases have been growing for non-traditional applications of database systems, and several real-time applications are being developed using an object-oriented paradigm. The object-oriented approach seems promising for developing complex real-time database applications. However, it is not clear whether object-oriented database systems would be superior than relational database systems for supporting real-time applications. In this paper, we address issues that must be investigated in order to design and develop an object-oriented database system for real-time applications. Also, we present a model that integrates features for scheduling real-time transactions with the traditional object-oriented database model.<<ETX>>","PeriodicalId":399167,"journal":{"name":"Proceedings of 2nd IEEE Workshop on Real-Time Applications","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129408094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
LACATRE is a graphical tool intended to help the design of applications requiring multitasking real time executives. Within the software life cycle, it covers both preliminary and detailed design. The first version of this tool gave preference to the tasking aspect of an application by the modelling of both low level objects, issued from real time kernels, and high level application objects, close to specification methods. This paper presents the data modelling introduced in the LACATRE language, in order to lead to a quasi complete code generation of an application target programme. Two other issues are brought up with data modelling: the introduction of control variables used for simulation and programme correctness verification, and the definition of a graphical formalism for data flow representation.<>
{"title":"Data flow modelling in real time multitasking graphical design","authors":"J. Petit, J. Schwarz, M. Maranzana, J. Skubich","doi":"10.1109/RTA.1994.316138","DOIUrl":"https://doi.org/10.1109/RTA.1994.316138","url":null,"abstract":"LACATRE is a graphical tool intended to help the design of applications requiring multitasking real time executives. Within the software life cycle, it covers both preliminary and detailed design. The first version of this tool gave preference to the tasking aspect of an application by the modelling of both low level objects, issued from real time kernels, and high level application objects, close to specification methods. This paper presents the data modelling introduced in the LACATRE language, in order to lead to a quasi complete code generation of an application target programme. Two other issues are brought up with data modelling: the introduction of control variables used for simulation and programme correctness verification, and the definition of a graphical formalism for data flow representation.<<ETX>>","PeriodicalId":399167,"journal":{"name":"Proceedings of 2nd IEEE Workshop on Real-Time Applications","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128913467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Compiler techniques can help enhance average case execution and extract parallelism opportunities in distributed real time systems. We show that there are situations in which speculative execution with rollback can improve the performance of a hard real time system, either by improving average performance while not affecting the worst-case, or by actually decreasing worst-case execution time. We also show how related strategies for partial or total precomputation can lead to improved performance. We briefly discuss possible practical compiler transformation tools to detect chances of profitable speculative execution in real-time applications.<>
{"title":"Speculative execution in a real-time system","authors":"M. Younis, T. Marlowe, A. Stoyenko","doi":"10.1109/RTA.1994.316152","DOIUrl":"https://doi.org/10.1109/RTA.1994.316152","url":null,"abstract":"Compiler techniques can help enhance average case execution and extract parallelism opportunities in distributed real time systems. We show that there are situations in which speculative execution with rollback can improve the performance of a hard real time system, either by improving average performance while not affecting the worst-case, or by actually decreasing worst-case execution time. We also show how related strategies for partial or total precomputation can lead to improved performance. We briefly discuss possible practical compiler transformation tools to detect chances of profitable speculative execution in real-time applications.<<ETX>>","PeriodicalId":399167,"journal":{"name":"Proceedings of 2nd IEEE Workshop on Real-Time Applications","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116479096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reports simulation, synthesis, and eventual layout of an automotive Anti-lock Brake system (ABS) digital controller onto FPGA technology, and the potential migration of the design onto ASIC technology. Examination of its functionality, real-time response, implementation and testability is performed in an attempt to measure the usefulness of higher level design entry facilities such as VHDL in a rapid prototyping environment. Continuous online testing is included using periodic sample injections where the resultant generated values are compared to signatures known a priori, without compromising functionality. Conclusions are drawn from the design's simulation and synthesis using VHDL onto FPGAs, ASIC migration, and CAD Tool capabilities/requirements/limitations with respect to real-time, data path synthesis for general controller applications involving asynchronous elements.<>
{"title":"Rapid prototyping and synthesis of a self-testing ABS controller using CAD tools","authors":"B. Hold, P. Bhatt, V. Agarwal","doi":"10.1109/RTA.1994.316164","DOIUrl":"https://doi.org/10.1109/RTA.1994.316164","url":null,"abstract":"This paper reports simulation, synthesis, and eventual layout of an automotive Anti-lock Brake system (ABS) digital controller onto FPGA technology, and the potential migration of the design onto ASIC technology. Examination of its functionality, real-time response, implementation and testability is performed in an attempt to measure the usefulness of higher level design entry facilities such as VHDL in a rapid prototyping environment. Continuous online testing is included using periodic sample injections where the resultant generated values are compared to signatures known a priori, without compromising functionality. Conclusions are drawn from the design's simulation and synthesis using VHDL onto FPGAs, ASIC migration, and CAD Tool capabilities/requirements/limitations with respect to real-time, data path synthesis for general controller applications involving asynchronous elements.<<ETX>>","PeriodicalId":399167,"journal":{"name":"Proceedings of 2nd IEEE Workshop on Real-Time Applications","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121936630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems. Issues include how to utilize knowledge of transport delays, how to evaluate timing constraints based upon time of observation, how to order and assemble multiple observations that happen closely, algorithms for run-time evaluation, and application programmers interface.<>
{"title":"Evaluating distributed timing constraints - implementing run-time mechanisms","authors":"C. H. Kristensen, N. Drejer","doi":"10.1109/RTA.1994.316165","DOIUrl":"https://doi.org/10.1109/RTA.1994.316165","url":null,"abstract":"We describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems. Issues include how to utilize knowledge of transport delays, how to evaluate timing constraints based upon time of observation, how to order and assemble multiple observations that happen closely, algorithms for run-time evaluation, and application programmers interface.<<ETX>>","PeriodicalId":399167,"journal":{"name":"Proceedings of 2nd IEEE Workshop on Real-Time Applications","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122921877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dependability assessment plays an important role in the design and validation of fault-tolerant real-lime computer systems. Dependability models provide measures such as reliability, safety and mean time to failure as functions of the component failure rates and fault/error coverage probabilities. In this paper we present a decomposition technique that accounts for both the hardware and software architectural characteristics of the modelled systems. Stochastic reward nets are employed as a unique modeling framework. Dependability of a railroad control computer, which relies an software techniques for fault/error handling, is analysed as an application example.<>
{"title":"A stochastic reward net model for dependability analysis of real-time computing systems","authors":"C. Constazltinescu, Kishor S. Trivedi","doi":"10.1109/RTA.1994.316162","DOIUrl":"https://doi.org/10.1109/RTA.1994.316162","url":null,"abstract":"Dependability assessment plays an important role in the design and validation of fault-tolerant real-lime computer systems. Dependability models provide measures such as reliability, safety and mean time to failure as functions of the component failure rates and fault/error coverage probabilities. In this paper we present a decomposition technique that accounts for both the hardware and software architectural characteristics of the modelled systems. Stochastic reward nets are employed as a unique modeling framework. Dependability of a railroad control computer, which relies an software techniques for fault/error handling, is analysed as an application example.<<ETX>>","PeriodicalId":399167,"journal":{"name":"Proceedings of 2nd IEEE Workshop on Real-Time Applications","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121234147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper analyzes the problems of developing an open architecture real-time platform that supports rapid development and deployment of applications. A solution using value-added domain specific components layered on a state-of-the-art computing system is described, along with a case history of an application employing the technology. Limitations with the solution and areas for future work are also discussed.<>
{"title":"Designing a real-time platform for rapid development","authors":"N. Olsen","doi":"10.1109/RTA.1994.316145","DOIUrl":"https://doi.org/10.1109/RTA.1994.316145","url":null,"abstract":"This paper analyzes the problems of developing an open architecture real-time platform that supports rapid development and deployment of applications. A solution using value-added domain specific components layered on a state-of-the-art computing system is described, along with a case history of an application employing the technology. Limitations with the solution and areas for future work are also discussed.<<ETX>>","PeriodicalId":399167,"journal":{"name":"Proceedings of 2nd IEEE Workshop on Real-Time Applications","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122255673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose that part of the reason for the relatively immature state of real-time programming is due the expense of objects traditionally controlled by real-time systems, which limits general exposure of real-time programming within the computing community. As a partial response we are building an inexpensive real-time testbed based on an arcade type pinball machine. The system will be based on readily available systems, components, and software. Our experiences, including developed software, will be made available to the academic/research community at large.<>
{"title":"An inexpensive real-time testbed-the Pinball Player project","authors":"D. Clark","doi":"10.1109/RTA.1994.316148","DOIUrl":"https://doi.org/10.1109/RTA.1994.316148","url":null,"abstract":"We propose that part of the reason for the relatively immature state of real-time programming is due the expense of objects traditionally controlled by real-time systems, which limits general exposure of real-time programming within the computing community. As a partial response we are building an inexpensive real-time testbed based on an arcade type pinball machine. The system will be based on readily available systems, components, and software. Our experiences, including developed software, will be made available to the academic/research community at large.<<ETX>>","PeriodicalId":399167,"journal":{"name":"Proceedings of 2nd IEEE Workshop on Real-Time Applications","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126628580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We outline the features of a cognitively compatible symbolic-connectionist architecture for complex data intensive time-critical domains especially in the diagnostic area. We examine how a symbolic-connectionist architecture copes with the time-critical and size complexity aspects of a real time alarm processing system developed for a regional power system control centre.<>
{"title":"A distributed real-time intelligent alarm processing system with symbolic-connectionist computation","authors":"R. Khosla, T. Dillon","doi":"10.1109/RTA.1994.316154","DOIUrl":"https://doi.org/10.1109/RTA.1994.316154","url":null,"abstract":"We outline the features of a cognitively compatible symbolic-connectionist architecture for complex data intensive time-critical domains especially in the diagnostic area. We examine how a symbolic-connectionist architecture copes with the time-critical and size complexity aspects of a real time alarm processing system developed for a regional power system control centre.<<ETX>>","PeriodicalId":399167,"journal":{"name":"Proceedings of 2nd IEEE Workshop on Real-Time Applications","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122619093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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