Pub Date : 1995-05-15DOI: 10.1109/RTTAS.1995.516191
S. Oikawa, H. Tokuda
Timing management for user-level real-time threads can be done with appropriate support of the kernel. When a specified time comes, the kernel makes a virtual processor to upcall a user-level scheduler for its timing management. Then, the timing management can suffer from the overhead of a user-level scheduler. The paper presents an efficient timing management mechanism for user-level real-time threads. By sharing user-level timers through the shared kernel/user structure and keeping the appropriate hints for them, redundant processing of them and events can be eliminated. The results of the performance evaluations show that the upcall performance of our user-level real-time threads is comparable to and more stable than that of kernel-provided real-time threads.
{"title":"Efficient timing management for user-level real-time threads","authors":"S. Oikawa, H. Tokuda","doi":"10.1109/RTTAS.1995.516191","DOIUrl":"https://doi.org/10.1109/RTTAS.1995.516191","url":null,"abstract":"Timing management for user-level real-time threads can be done with appropriate support of the kernel. When a specified time comes, the kernel makes a virtual processor to upcall a user-level scheduler for its timing management. Then, the timing management can suffer from the overhead of a user-level scheduler. The paper presents an efficient timing management mechanism for user-level real-time threads. By sharing user-level timers through the shared kernel/user structure and keeping the appropriate hints for them, redundant processing of them and events can be eliminated. The results of the performance evaluations show that the upcall performance of our user-level real-time threads is comparable to and more stable than that of kernel-provided real-time threads.","PeriodicalId":265113,"journal":{"name":"Proceedings Real-Time Technology and Applications Symposium","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133754980","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}
Pub Date : 1995-05-15DOI: 10.1109/RTTAS.1995.516197
D. Sides
The Johns Hopkins University Applied Physics Laboratory (JHU/APL), sponsored by the Oceanographer of the Navy and the Commander of the Submarine Development Squadron Twelve, has produced a real time data acquisition and display system to allow U.S. submarines to measure the in-situ ocean environment during standard patrol operations. The system is composed of a dynamically adaptable architecture that allows for a variety oceanographic data sensor sources in a "plug and play" fashion. This adaptability is carried throughout the system in terms of configuration management, data acquisition, calibration, processing and display of the available data. Faulted sensor packages can be replaced seamlessly, and previously unknown sensor types can be added, all with no software impact. At the heart of this architecture is the "Data Dictionary", a dynamically configurable data base that describes all aspects of the sensor data necessary to carry out the system objectives.
{"title":"A dynamically adaptable real time data acquisition and display system","authors":"D. Sides","doi":"10.1109/RTTAS.1995.516197","DOIUrl":"https://doi.org/10.1109/RTTAS.1995.516197","url":null,"abstract":"The Johns Hopkins University Applied Physics Laboratory (JHU/APL), sponsored by the Oceanographer of the Navy and the Commander of the Submarine Development Squadron Twelve, has produced a real time data acquisition and display system to allow U.S. submarines to measure the in-situ ocean environment during standard patrol operations. The system is composed of a dynamically adaptable architecture that allows for a variety oceanographic data sensor sources in a \"plug and play\" fashion. This adaptability is carried throughout the system in terms of configuration management, data acquisition, calibration, processing and display of the available data. Faulted sensor packages can be replaced seamlessly, and previously unknown sensor types can be added, all with no software impact. At the heart of this architecture is the \"Data Dictionary\", a dynamically configurable data base that describes all aspects of the sensor data necessary to carry out the system objectives.","PeriodicalId":265113,"journal":{"name":"Proceedings Real-Time Technology and Applications Symposium","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132899183","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}
Pub Date : 1995-05-15DOI: 10.1109/RTTAS.1995.516193
L. Lindh, Johan Stärner, Johan Furunäs
The article presents three different implementations of a traditional real-time kernel in hardware. All approaches improved performance and determinism by several orders of magnitude when compared with software-based real time kernels. The first implementation provides an integrated deterministic CPU and a deterministic and high performance multitasking real time kernel in hardware. The second implementation provides a deterministic and high performance standalone multitasking real time kernel in hardware and the last implementation provides a deterministic and high performance real time kernel for homogeneous and heterogeneous multiprocessor real-time systems.
{"title":"From single to multiprocessor real-time kernels in hardware","authors":"L. Lindh, Johan Stärner, Johan Furunäs","doi":"10.1109/RTTAS.1995.516193","DOIUrl":"https://doi.org/10.1109/RTTAS.1995.516193","url":null,"abstract":"The article presents three different implementations of a traditional real-time kernel in hardware. All approaches improved performance and determinism by several orders of magnitude when compared with software-based real time kernels. The first implementation provides an integrated deterministic CPU and a deterministic and high performance multitasking real time kernel in hardware. The second implementation provides a deterministic and high performance standalone multitasking real time kernel in hardware and the last implementation provides a deterministic and high performance real time kernel for homogeneous and heterogeneous multiprocessor real-time systems.","PeriodicalId":265113,"journal":{"name":"Proceedings Real-Time Technology and Applications Symposium","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121234036","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}
Pub Date : 1995-05-15DOI: 10.1109/RTTAS.1995.516212
Ahmad Abualsamid, Raed Alqadi, P. Ramanathan
High-level synthesis has become commonplace in many areas of computing such as VLSI design and digital signal processing. However, it is just beginning to receive attention in the area of real-time systems. Given a real-time application and a design library of components, high-level synthesis involves three main steps: (i) estimation of processors and resources required to meet the constraints of the application, (ii) identifying suitable architectures using the components from the design library, and (iii) scheduling application tasks on the selected architecture. In this paper, we focus on the first and the third steps of this process. Specifically, we identify key issues in parallelizing these two steps. We then discuss approaches to deal with these issues and present results of our distributed implementation. The results of this implementation on a network of workstations show that considerable speedup in overall runtimes can be achieved by using multiple workstations.
{"title":"Distributed synthesis of real-time computer systems","authors":"Ahmad Abualsamid, Raed Alqadi, P. Ramanathan","doi":"10.1109/RTTAS.1995.516212","DOIUrl":"https://doi.org/10.1109/RTTAS.1995.516212","url":null,"abstract":"High-level synthesis has become commonplace in many areas of computing such as VLSI design and digital signal processing. However, it is just beginning to receive attention in the area of real-time systems. Given a real-time application and a design library of components, high-level synthesis involves three main steps: (i) estimation of processors and resources required to meet the constraints of the application, (ii) identifying suitable architectures using the components from the design library, and (iii) scheduling application tasks on the selected architecture. In this paper, we focus on the first and the third steps of this process. Specifically, we identify key issues in parallelizing these two steps. We then discuss approaches to deal with these issues and present results of our distributed implementation. The results of this implementation on a network of workstations show that considerable speedup in overall runtimes can be achieved by using multiple workstations.","PeriodicalId":265113,"journal":{"name":"Proceedings Real-Time Technology and Applications Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127129710","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}
Pub Date : 1995-05-15DOI: 10.1109/RTTAS.1995.516200
Kevin Mellott, Chris Taylor
We present the analysis of a real-time CPU scheduling algorithm specifically designed to provide processing guarantees for multimedia applications. It is motivated by the need to reduce the number of contest switch operations in protocol processing while being able to provide bandwidth and delay guarantees to each protocol session. We have implemented this scheme in the NetBSD operating system. Our experimental and simulation results show that there is substantial reduction in the number of context switch operations. We present the scheme and derive its schedulability test.
{"title":"RMDP-a real-time CPU scheduling algorithm to provide QoS guarantees for protocol processing","authors":"Kevin Mellott, Chris Taylor","doi":"10.1109/RTTAS.1995.516200","DOIUrl":"https://doi.org/10.1109/RTTAS.1995.516200","url":null,"abstract":"We present the analysis of a real-time CPU scheduling algorithm specifically designed to provide processing guarantees for multimedia applications. It is motivated by the need to reduce the number of contest switch operations in protocol processing while being able to provide bandwidth and delay guarantees to each protocol session. We have implemented this scheme in the NetBSD operating system. Our experimental and simulation results show that there is substantial reduction in the number of context switch operations. We present the scheme and derive its schedulability test.","PeriodicalId":265113,"journal":{"name":"Proceedings Real-Time Technology and Applications Symposium","volume":"515 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123077902","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}
Pub Date : 1995-05-15DOI: 10.1109/RTTAS.1995.516216
Tei-Wei Kuo, A. Mok
Describes the design of the Real-Time Object Management Interface (RTOMI), a distributed real-time data-access interface which runs on multiprocessor platforms. RTOMI is designed to facilitate the implementation of real-time data-intensive applications by providing process scheduling and data distribution mechanisms that exploit the concept of "similarity". RTOMI is implemented to run on a multi-board Intel System 520 which is used as a testbed for evaluating our real-time transaction scheduling and data distribution algorithms.
描述了实时对象管理接口(RTOMI)的设计，RTOMI是一种运行在多处理器平台上的分布式实时数据访问接口。RTOMI旨在通过提供利用“相似性”概念的进程调度和数据分发机制，促进实时数据密集型应用程序的实现。RTOMI被实现在多板Intel System 520上运行，该系统被用作评估实时事务调度和数据分发算法的测试平台。
{"title":"The design and implementation of a Real-Time Object Management Interface","authors":"Tei-Wei Kuo, A. Mok","doi":"10.1109/RTTAS.1995.516216","DOIUrl":"https://doi.org/10.1109/RTTAS.1995.516216","url":null,"abstract":"Describes the design of the Real-Time Object Management Interface (RTOMI), a distributed real-time data-access interface which runs on multiprocessor platforms. RTOMI is designed to facilitate the implementation of real-time data-intensive applications by providing process scheduling and data distribution mechanisms that exploit the concept of \"similarity\". RTOMI is implemented to run on a multi-board Intel System 520 which is used as a testbed for evaluating our real-time transaction scheduling and data distribution algorithms.","PeriodicalId":265113,"journal":{"name":"Proceedings Real-Time Technology and Applications Symposium","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122180457","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}
Pub Date : 1995-05-15DOI: 10.1109/RTTAS.1995.516201
V. Kamat, S. Ganesan
The paper addresses the general problem of the detection of vehicle license plates from road scenes, for the purpose of vehicle tracking. It describes an algorithm for detecting a license plate from a road scene acquired by a CCD camera, using image processing techniques, where the authors have used the Hough transform (HT) for line detection (the shape of the license plates is defined by lines) because it fits well into this application as it facilitates the selection of lines from specific areas and specific orientations within the image. This is followed by a brief description of the image processing system on which this algorithm has been implemented. Lastly, the results and conclusions of the application of the license plate detection algorithm to a real vehicle are discussed.
{"title":"An efficient implementation of the Hough transform for detecting vehicle license plates using DSP'S","authors":"V. Kamat, S. Ganesan","doi":"10.1109/RTTAS.1995.516201","DOIUrl":"https://doi.org/10.1109/RTTAS.1995.516201","url":null,"abstract":"The paper addresses the general problem of the detection of vehicle license plates from road scenes, for the purpose of vehicle tracking. It describes an algorithm for detecting a license plate from a road scene acquired by a CCD camera, using image processing techniques, where the authors have used the Hough transform (HT) for line detection (the shape of the license plates is defined by lines) because it fits well into this application as it facilitates the selection of lines from specific areas and specific orientations within the image. This is followed by a brief description of the image processing system on which this algorithm has been implemented. Lastly, the results and conclusions of the application of the license plate detection algorithm to a real vehicle are discussed.","PeriodicalId":265113,"journal":{"name":"Proceedings Real-Time Technology and Applications Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131698666","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}
Pub Date : 1995-05-15DOI: 10.1109/RTTAS.1995.516208
Jin Yang, A. Mok, D. Stuart
We have implemented a new-generation modechart verifier called vf3. The new verifier is capable of dealing with modecharts with arbitrary hierarchy. More importantly, it employs several novel strategies to effectively reduce the search space while speeding up the verification process. It represents the computation graph for a modechart in a more compact form called a 'zone-based computation graph'. It uses on-the-fly deterministic pruning to reduce the outgoing edges from nodes in a graph. Finally, it builds on-the-fly a quotient graph based on a given real-time logic (RTL) formula. Our experimental results show that vf3 reduces the sizes of computation graphs by factors ranging from 2 to 10.
{"title":"A new generation modechart verifier","authors":"Jin Yang, A. Mok, D. Stuart","doi":"10.1109/RTTAS.1995.516208","DOIUrl":"https://doi.org/10.1109/RTTAS.1995.516208","url":null,"abstract":"We have implemented a new-generation modechart verifier called vf3. The new verifier is capable of dealing with modecharts with arbitrary hierarchy. More importantly, it employs several novel strategies to effectively reduce the search space while speeding up the verification process. It represents the computation graph for a modechart in a more compact form called a 'zone-based computation graph'. It uses on-the-fly deterministic pruning to reduce the outgoing edges from nodes in a graph. Finally, it builds on-the-fly a quotient graph based on a given real-time logic (RTL) formula. Our experimental results show that vf3 reduces the sizes of computation graphs by factors ranging from 2 to 10.","PeriodicalId":265113,"journal":{"name":"Proceedings Real-Time Technology and Applications Symposium","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129520406","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}
Pub Date : 1995-05-15DOI: 10.1109/RTTAS.1995.516192
A. Kanevsky, P. Krupp, P. Wallace
We demonstrate a new computing paradigm for the evolution of the long life-cycle defense system with stringent safety, timing and dependability requirements, namely, the multiple target tracking (MTT) part of a surveillance radar system. We demonstrate the new paradigm's capability for the support of system upgrades in system software, hardware, and application software while maintaining the existing baseline performance. This new paradigm shares many characteristics with the SEI/CMU Simplex Architecture whose applicability has been demonstrated for a prototypical industrial feedback control application. We present the concepts of our paradigm, lessons learned in applying the paradigm to surveillance radar, and lessons learned implementing the paradigm by integrating standard technologies.
{"title":"Paradigm for building robust real-time distributed mission-critical systems","authors":"A. Kanevsky, P. Krupp, P. Wallace","doi":"10.1109/RTTAS.1995.516192","DOIUrl":"https://doi.org/10.1109/RTTAS.1995.516192","url":null,"abstract":"We demonstrate a new computing paradigm for the evolution of the long life-cycle defense system with stringent safety, timing and dependability requirements, namely, the multiple target tracking (MTT) part of a surveillance radar system. We demonstrate the new paradigm's capability for the support of system upgrades in system software, hardware, and application software while maintaining the existing baseline performance. This new paradigm shares many characteristics with the SEI/CMU Simplex Architecture whose applicability has been demonstrated for a prototypical industrial feedback control application. We present the concepts of our paradigm, lessons learned in applying the paradigm to surveillance radar, and lessons learned implementing the paradigm by integrating standard technologies.","PeriodicalId":265113,"journal":{"name":"Proceedings Real-Time Technology and Applications Symposium","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116514573","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}
Pub Date : 1995-05-15DOI: 10.1109/RTTAS.1995.516189
G. Bollella, K. Jeffay
Distributed multimedia applications are typical of a new class of workstation applications that require real-time communication and computation services to be effective. Unfortunately, there remains a wide gap between the development of real-time computing technology in the research community and the deployment of real-time solutions in commercial systems. We explore technology for allowing two operating systems, a general purpose operating system and a predictable real-time kernel, to co-exist on the same hardware. We discuss the problems of multiplexing shared devices and partitioning shared data structures to accommodate two operating systems, and present a CPU executive that allows the IBM Microkernel (a derivative of the Mach microkernel) with an OSF/1 server to co-exist with a simple real-time kernel we have built. We also extend the traditional theory of scheduling periodic tasks on a uniprocessor to accommodate the case where a real-time kernel is allocated only a fraction of the total CPU capacity.
{"title":"Support for real-time computing within general purpose operating systems-supporting co-resident operating systems","authors":"G. Bollella, K. Jeffay","doi":"10.1109/RTTAS.1995.516189","DOIUrl":"https://doi.org/10.1109/RTTAS.1995.516189","url":null,"abstract":"Distributed multimedia applications are typical of a new class of workstation applications that require real-time communication and computation services to be effective. Unfortunately, there remains a wide gap between the development of real-time computing technology in the research community and the deployment of real-time solutions in commercial systems. We explore technology for allowing two operating systems, a general purpose operating system and a predictable real-time kernel, to co-exist on the same hardware. We discuss the problems of multiplexing shared devices and partitioning shared data structures to accommodate two operating systems, and present a CPU executive that allows the IBM Microkernel (a derivative of the Mach microkernel) with an OSF/1 server to co-exist with a simple real-time kernel we have built. We also extend the traditional theory of scheduling periodic tasks on a uniprocessor to accommodate the case where a real-time kernel is allocated only a fraction of the total CPU capacity.","PeriodicalId":265113,"journal":{"name":"Proceedings Real-Time Technology and Applications Symposium","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131054592","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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