| 1. |
- Behnam, Moris, et al.
(författare)
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A Hierarchical Approach for Reconfigurable and Adaptive Embedded Systems
- 2008
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Ingår i: APRES'08 Adaptive and Reconfigurable Embedded Systems. ; , s. 51-54
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Konferensbidrag (refereegranskat)abstract
- Adaptive and reconfigurable embedded systems have been gaining an increasing interest in the past year from both academics and industry. This paper presents our work on hierarchical scheduling frameworks (HSF) intended as a backbone architecture facilitating the implementation of operating system support for adaptability and reconfigurability.
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| 2. |
- Behnam, Moris, et al.
(författare)
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An overrun method to support composition of semi-independent real-time components
- 2008
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Ingår i: Proceedings - International Computer Software and Applications Conference. - 9780769532622 ; , s. 1347-1352
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Konferensbidrag (refereegranskat)abstract
- Engineers of embedded software systems rely on efficient design techniques and tools along with efficient run-time support. In the design of complex embedded real-time systems, the Hierarchical Scheduling Framework (HSF) has been introduced as a design-time framework enabling compositional schedulability analysis of embedded software systems with real-time properties. Moreover, the HSF provides a run-time framework guaranteeing that these non-functional requirements are met. In this paper a system consists of a number of semi-independent components called subsystems, and these subsystems are allowed to share logical resources. The HSF makes sure that the individual subsystems respect their allocated CPU budgets. However, as semi-independent sub-systems share logical resources, extra complexity is introduced. Specifically, the contribution of this paper is a novel method to allow for budget overruns; a common scenario when a subsystem utilizes shared logical resources. This proposed method is not only more resource efficient than existing methods, but it is also more appropriate for supporting composability of independently developed real-time subsystems.
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| 3. |
- Behnam, Moris, et al.
(författare)
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Independent Abstraction and Dynamic Slack Reclaiming in Hierarchical Real-Time Open Systems
- 2007
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Ingår i: Proceedings of the Work-In-Progress (WIP) session of the 19th Euromicro Conference on Real-Time Systems (ECRTS'07), Pisa, Italy. ; , s. 1-4
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Konferensbidrag (refereegranskat)abstract
- Independent subsystem abstraction allows subsystems to be developed and validated separately and supports an easier subsystem integration. In particular, this approach is desirable in open systems, since it does not require knowledge of temporal behaviour of other subsystems. However, independentabstraction, assuming the worst-case CPU supply pattern, requires extra CPU allocations. We present our work in progress on dynamic slack reclamation, which keeps track of such extra CPU allocations at run time. We are also investigating how to utilize those extra resources for supporting soft real-time tasks.
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| 4. |
- Behnam, Moris, 1973-, et al.
(författare)
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Overrun Methods and Resource Holding Times for Hierarchical Scheduling of Semi-Independent Real-Time Systems
- 2010
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Ingår i: IEEE Transactions on Industrial Informatics. - 1551-3203. ; 6:1, s. 93-104
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Tidskriftsartikel (refereegranskat)abstract
- The Hierarchical Scheduling Framework (HSF) has been introduced as a design-time framework toenable compositional schedulability analysis of embedded software systems with real-time properties. Inthis paper a software system consists of a number of semi-independent components called subsystems.Subsystems are developed independently and later integrated to form a system. To support this designprocess, in the paper, the proposed methods allow non-intrusive configuration and tuning of subsystemtiming-behaviour via subsystem interfaces for selecting scheduling parameters.This paper considers three methods to handle overruns due to resource sharing between subsystemsin the HSF. For each one of these three overrun methods corresponding scheduling algorithms and associatedschedulability analysis are presented together with analysis that shows under what circumstances one or the other is preferred. The analysis is generalized to allow for both Fixed Priority Scheduling (FPS)and Earliest Deadline First (EDF) scheduling. Also, a further contribution of the paper is the techniqueof calculating resource-holding times within the framework under different scheduling algorithms; theresource holding times being an important parameter in the global schedulability analysis.
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| 5. |
- Behnam, Moris, et al.
(författare)
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Overrun Methods for Semi-Independent Real-Time Hierarchical Scheduling
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Hierarchical Scheduling Framework (HSF) has been introduced as a design-time framework to enable compositional schedulability analysis of embedded software systems with real-time properties. In this paper a software system consists of a number of semi-independent components called subsystems. Subsystems are developed independently and later integrated to form a system. To support this design process, in the paper, the proposed methods allow non-intrusive configuration and tuning of subsystem timing-behaviour via subsystem interfaces for selecting scheduling parameters. This paper considers three methods to handle overruns due to resource sharing between subsystems in the HSF. For each one of these three overrun methods corresponding scheduling algorithms The work in this paper is supported by the Swedish Foundation for Strategic Research (SSF), via the research programme PROGRESS. and associated schedulability analysis are presented together with analysis that shows under what circumstances one or the other is preferred. The analysis is generalized to allow for both Fixed Priority Scheduling (FPS) and Earliest Deadline First (EDF) scheduling. Also, a further contribution of the paper is the technique of calculating resource-holding times within the framework under different scheduling algorithms. The resource holding times being an important parameter in the global schedulability analysis.
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| 6. |
- Behnam, Moris, et al.
(författare)
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Real-Time Subsystem Integration in the Presence of Shared Resources
- 2006
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Ingår i: Proceedings of the Work-In-Progress (WIP) session of the 27th IEEE Real-Time Systems Symposium (RTSS'06), Rio de Janeiro, Brazil.
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Konferensbidrag (refereegranskat)abstract
- We present our ongoing work to support the difficult, time consuming, and error-prone process of subsystem integration in the real-time domain. Our work will result in methods where independently developed subsystems, including both hard real-time and soft real-time functions, can be easily integrated without resulting unpredictable timing behaviour. The methods will also facilitate subsystem reuse, since a subsystem can easily be integrated in a new environment. Related research and methods are presented, together with our ongoing work in the area.
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| 7. |
- Behnam, Moris, et al.
(författare)
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Scheduling of Semi-Independent Real-Time Components: Overrun Methods and Resource Holding Times
- 2008
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Ingår i: Proceedings of the 13th IEEE International Conference on Emerging echnologies and Factory Automation (ETFA’08). - 9781424415052 ; , s. 575-582
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Konferensbidrag (refereegranskat)abstract
- The Hierarchical Scheduling Framework (HSF) has been introduced as a design-time framework enabling compositional schedulability analysis of embedded software systems with real-time properties. In this paper a system consists of a number of semi-independent components called subsystems. Subsystems are developed independently and later integrated to form a system. To support this design process, our proposed methods allow nonintrusive configuration and tuning of subsystem timing behaviour via subsystem interfaces for selecting scheduling parameters. This paper considers two methods to handle overruns due to resource sharing between subsystems in the HSF. We present the scheduling algorithms for overruns and their associated schedulability analysis, together with analysis that shows under what circumstances one or the other overrun method is preferred. Furthermore, we show how to calculate resource-holding times within our framework.
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| 8. |
- Behnam, Moris, et al.
(författare)
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SIRAP : A Synchronization Protocol for Hierarchical Resource Sharing in Real-Time Open Systems
- 2007
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Ingår i: EMSOFT'07: Proceedings of the Seventh ACM and IEEE International Conference on Embedded Software. - New York, New York, USA : ACM Press. - 9781595938251 ; , s. 279-288
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Konferensbidrag (refereegranskat)abstract
- This paper presents a protocol for resource sharing in a hierarchical real-time scheduling framework. Targeting real-time open systems, the protocol and the scheduling framework significantly reduce the efforts and errors associated with integrating multiple semi-independent subsystems on a single processor. Thus, our proposed techniques facilitate modern software development processes, where subsystems are developed by independent teams (or subcontractors) and at a later stage integrated into a single product. Using our solution, a subsystem need not know, and is not dependent on, the timing behaviour of other subsystems; even though they share mutually exclusive resources. In this paper we also prove the correctness of our approach and evaluate its efficiency.
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| 9. |
- Behnam, Moris, et al.
(författare)
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SIRAP: A Global Resource Sharing Protocol Facilitating Integration of Semi-independent Real-Time Systems
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a protocol for resource sharing in a hierarchical real-time scheduling framework. Together, the protocol and the scheduling framework significantly reduce the efforts and errors associated with integrating multiple semi-independent subsystems on a single processor. Thus, our proposed techniques facilitate modern software development processes, where subsystems are developed by independent teams (or subcontractors) and at a later stage integrated into a single product. Using our solution, a subsystem need not know, and is not dependent on, the timing behaviour of other subsystems; even though they share mutually exclusive resources. In this paper we also prove the correctness of our approach and evaluate its efficiency.
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| 10. |
- Behnam, Moris, et al.
(författare)
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Synchronization protocols for hierarchical real-time scheduling frameworks
- 2008
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Ingår i: Proceedings of the 1st Workshop on Compositional Theory and Technology for Real-Time Embedded Systems (CRTS'08) in conjunction with the 29th IEEE International Real-Time Systems Symposium (RTSS'08), Barcelona, Spain.
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Konferensbidrag (refereegranskat)
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