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  • 151.
    Mubeen, Saad
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Nikolaidis, Pavlos
    Mälardalen University.
    Didic, Alma
    Mälardalen University.
    Pei Breivold, Hongyu
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. ABB Corporate Research, Västerås, Sweden .
    Sandström, Kristian
    Swedish Institute of Computer Science, Kista, Sweden .
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Delay Mitigation in Offloaded Cloud Controllers in Industrial IoT2017In: IEEE Access, E-ISSN 2169-3536, ISSN 21693536, Vol. 5, p. 4418-4430, article id 7879156Article in journal (Refereed)
    Abstract [en]

    This paper investigates the interplay of cloud computing, fog computing, and Internet of Things (IoT) in control applications targeting the automation industry. In this context, a prototype is developed to explore the use of IoT devices that communicate with a cloud-based controller, i.e., the controller is offloaded to cloud or fog. Several experiments are performed to investigate the consequences of having a cloud server between the end device and the controller. The experiments are performed while considering arbitrary jitter and delays, i.e., they can be smaller than, equal to, or greater than the sampling period. This paper also applies mitigation mechanisms to deal with the delays and jitter that are caused by the networks when the controller is offloaded to the fog or cloud.

  • 152.
    Mubeen, Saad
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Pei-Breivold, Hongyu
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. ABB Corporate Research, Sweden.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Ensuring Quality of Service through Modeling of Service-level Agreements in Industrial IoT2016In: 12th Swedish National Computer Networking Workshop SNCNW 2016, Sundsvall, Sweden, 2016Conference paper (Refereed)
    Abstract [en]

    Cloud computing and Internet of Things (IoT) are computing technologies that provide services to consumers and businesses, allowing organizations to become more agile and flexible. Therefore, ensuring the quality of service through service-level agreements for such cloud-based services is crucial for both the service providers and service consumers. Within the context of industrial IoT applications, modeling of the service-level agreements has not received much attention in the existing literature. In this paper, we discuss ongoing work on modeling of service-level agreements to ensure quality of service in industrial IoT applications. The modeling approach aims to consider the agreements between an end device and the cloud; between a service provider and a service user; and among cloud services. The approach also aims to model the service-level agreements when a company assumes a double role, being the provider as well as the user of the services. We aim to provide a proof of concept by developing a prototype in an industrial setup. Using the prototype, we plan to show usability of the approach.

  • 153.
    Nemati, Farhang
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    An Investigation of Synchronization under Multiprocessors Hierarchical Scheduling2009In: Proceedings of the Work-In-Progress (WIP) session of the 21st Euromicro Conference on Real-Time Systems (ECRTS'09), 2009Conference paper (Refereed)
    Abstract [en]

    community, considerable work has been done on real-time multiprocessor scheduling algorithms where it is assumed the tasks are independent. However in practice a typical real-time system includes tasks that share resources. On the other hand, synchronization in the multiprocessor context has not received enough attention. In this paper we propose an extension to multiprocessor hierarchical scheduling to support resource sharing. We extend the scheduling framework with an existing synchronization protocol for global scheduling in multi-core systems.

  • 154.
    Nemati, Farhang
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Efficiently Migrating Real-Time Systems to Multi-Cores2009In: Proceedings of 14th IEEE International Conference on Emerging Techonologies and Factory (ETFA'09), 2009, p. 1205-1212Conference paper (Refereed)
    Abstract [en]

    Power consumption and thermal problems limit a further increase of speed in single-core processors. Multi-core architectures have therefore received significant interest. However, a shift to multi-core processors is a big challenge for developers of embedded real-time systems, especially considering existing “legacy” systems which have been developed with uniprocessor assumptions. These systems have been developed and maintained by many developers over many years, and cannot easily be replaced due to the huge development investments they represent. An important issue while migrating to multi-cores is how to distribute tasks among cores to increase performance offered by the multi-core platform. In this paper we propose a partitioning algorithm to efficiently distribute legacy system tasks along with newly developed ones onto different cores. The target of the partitioning is increasing system performance while ensuring correctness.

  • 155.
    Nemati, Farhang
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Independently-Developed Real-Time Systems on Multi-Cores with Shared Resources2011In: 23rd EUROMICRO Conference on Real-Time Systems (ECRTS'11), Porto, Portugal, 2011, p. 251-261Conference paper (Refereed)
    Abstract [en]

    In this paper we propose a synchronization protocol for resource sharing among independently-developed real-time systems on multi-coreplatforms. The systems may use different scheduling policies and they may have their own local priority settings. Each system is allocated on a dedicated processor (core). In the proposed synchronization protocol, each system is abstracted by an interface which abstracts the information needed for supporting global resources. The protocol facilitates the composability of various real-time systems with different scheduling and priority settings on a multi-core platform. We have performed experimental evaluations and compared the performance of our proposed protocol (MSOS) against the two existing synchronization protocols MPCP and FMLP. The results show that the new synchronization protocol enables composability without any significant loss of performance. In fact, in most cases the new protocol performs better than at least one of the other two synchronization protocols. Hence, we believe that the proposed protocol is a viable solution for synchronization among independently-developedreal-time systems executing on a multi-core platform.

  • 156.
    Nemati, Farhang
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Independently-developed Systems on Multi-cores with Shared Resources2010In: 3rd Workshop on Compositional Theory and Technology for Real-Time Embedded Systems (CRTS'10) in conjunction with the 31th IEEE International Real-Time Systems Symposium (RTSS'10), San Diego, CA, USA, 2010Conference paper (Refereed)
    Abstract [en]

    In this paper we propose a synchronization protocol for resource sharing among independently-developed real-time systems on multi-core platforms. The systems may use different scheduling policies and they may have arbitrary priority settings. When using this synchronization protocol each processor is abstracted by an interface which consists of a set of requirements. A requirement depends only on the worst-case time the processor may wait for resources, i.e., the maximum number of times that the resources can be blocked by other processors. We have derived schedulability conditions for each processor and based on the analysis we extract the interface of the processor. In this paper, we focus on the cases when each system is allocated on a dedicated processor.

  • 157.
    Nemati, Farhang
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Multiprocessor Synchronization and Hierarchical Scheduling2009In: Proceedings of the First IEEE International Workshop on Real-time Systems on Multicore Platforms: Theory and Practice (XRTS-2009) in conjunction with ICPP'09, 2009, p. 58-64Conference paper (Refereed)
    Abstract [en]

    Multi-core architectures have received significant interest as thermal and power consumption problems limit further increase of speed in single-cores. In the multi-core research community a considerable amount of work has been done on real-time multi-core scheduling algorithms where it is assumed tasks are independent. However, synchronization of dependent tasks executing on multi-cores has not received as much attention, even though typical real-time systems in practice include tasks that share resources. In this paper we propose a synchronization protocol for hierarchically scheduledmulti-core systems, and we present a comparison between the presented protocol and existing multi-core synchronization protocols. The presented protocol groups dependent tasks that directly or indirectly share mutually exclusive resources into independent components. Within a component dependent tasks use classical uniprocessor synchronization protocols, such as the Stack-based Resource allocation Protocol. The components are then scheduled on the cores by a global scheduler. There are two major approaches for scheduling multicore: partitioned and global scheduling. While most existing multi-core synchronization protocols support only one category, the protocol presented in this paper is developed to handle both scheduling approaches. The presented approach is developed to allow for co-execution of existing legacy real-time applications along with new applications, i.e., a legacy application is put into one or more components preserving its own (original) scheduling and synchronization protocols.

  • 158.
    Nemati, Farhang
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Sharing Resources among Independently-developed Systems on Multi-cores2011In: ACM SIGBED Review, ISSN 1551-3688, Vol. 8, no 1, p. 46-53Article in journal (Refereed)
    Abstract [en]

    In this paper we propose a synchronization protocol for resource sharing among independently-developed real-time systems on multi-core platforms. The systems may use different scheduling policies and they may have arbitrary priority settings. When using this synchronization protocol each processor is abstracted by an interface which consists of a set of requirements. A requirement depends only on the worst-case time the processor may wait for resources, i.e., the maximum number of times that the resources can be blocked by other processors. We have derived schedulability conditions for each processor and based on the analysis we extract the interface of the processor. In this paper, we focus on the cases when each system is allocated on a dedicated processor.

  • 159.
    Nemati, Farhang
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    J. Bril, Reinder
    Eindhoven University of Technology.
    Investigation of Implementing a Synchronization Protocol under Multiprocessors Hierarchical Scheduling2009In: Proceedings of the Work-In-Progress (WIP) session of 14th IEEE International Conference on Emerging Techonologies and Factory (ETFA'09), 2009Conference paper (Refereed)
    Abstract [en]

    In the multi-core and multiprocessor domain, there has been considerable work done on scheduling techniques assuming that real-time tasks are independent. In practice a typical real-time system usually share logical resources among tasks. However, synchronization in the multiprocessor area has not received enough attention. In this paper we investigate the possibilities of extending multiprocessor hierarchical scheduling to support an existing synchronization protocol (FMLP) in multiprocessor systems. We discuss problems regarding implementation of the synchronization protocol under the multiprocessor hierarchical scheduling.

  • 160.
    Nemati, Farhang
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Blocking-Aware Partitioning for Multiprocessors2010Report (Other academic)
    Abstract [en]

    In the multi-core and multiprocessor domain there are two scheduling approaches, global and partitioned scheduling. Under global scheduling each task can execute on any processor while under partitioned scheduling tasks are allocated to processors and migration of tasks among processors is not allowed. Under global scheduling the higher utilization bound can be achieved, but in practice the overheads of migrating tasks is high. On the other hand, besides simplicity and efficiency of partitioned scheduling protocols, existing scheduling and synchronization methods developed for uniprocessor platforms can more easily be extended to partitioned scheduling. This also simplifies migration of existing systems to multi-cores. An important issue related to partitioned scheduling is how to distribute tasks among processors/cores to increase performance offered by the platform. However, existing methods mostly assume independent tasks while in practice a typical real-time system contains tasks that share resources and they may block each other. In this paper we propose a blocking-aware partitioning algorithm to distribute tasks onto different processors. The proposed algorithm allocates a task set onto processors in a way that blocking times of tasks are decreased. This reduces the total utilization which has the potential to decrease the total number of needed processors/cores.

  • 161.
    Nemati, Farhang
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Partitioning Real-Time Systems on Multiprocessors with Shared Resources2010In: Lecture Notes in Computer Science, vol. 6490, Springer, 2010, p. 253-269Chapter in book (Refereed)
    Abstract [en]

    There are two main approaches to task scheduling on multiprocessor/multi-core platforms; 1) global scheduling, under which migration of tasks among processors is allowed, and 2) partitioned scheduling under which tasks are allocated onto processors and task migration is not allowed. Under global scheduling a higher utilization bound can be achieved, but in practice the overheads of migrating tasks is high. On the other hand under partitioned scheduling, besides simplicity and efficiency, existing scheduling and synchronization methods developed for uniprocessor platforms can more easily be extended to partitioned scheduling. However the partitioned scheduling protocols suffer from the problem of partitioning tasks among processors/cores which is a bin-packing problem. Therefore, several heuristic algorithms have been developed for partitioning a task set on multiprocessor platforms. However, these algorithms typically assume independent tasks while in practice real-time systems often contain tasks that share resources and hence may block each other.

    In this paper we propose a blocking-aware partitioning algorithm which allocates a task~set onto processors in a way that the overall amount of blocking times of tasks are decreased. The algorithm reduces the total utilization which, in turn, has the potential to decrease the total number of required processors (cores). In this paper we evaluate our algorithm and compare it with an existing similar algorithm. The comparison criteria includes both number of schedulable systems as well as processor reduction performance.

  • 162.
    Nikolaidis, Pavlos
    et al.
    Mälardalen University.
    Didic, Alma
    Mälardalen University.
    Mubeen, Saad
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Pei-Breivold, Hongyu
    ABB Corporate Research, Sweden.
    Sandström, Kristian
    ABB Corporate Research, Sweden.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Applying Mitigation Mechanisms for Cloud-based Controllers in Industrial IoT Applications2015In: Internet-of-Things Symposium IoT Symposium'15, 2015Conference paper (Refereed)
    Abstract [en]

    Cloud computing and Internet of Things (IoT) are two notable concepts that have evolved significantly over the past few years. In the automation industry, clouds are often used for monitoring vast amounts of data generated on the shop floor. Whereas, IoT is used to simplify the end devices and their connections to the rest of the system. In this paper we investigate the interplay of these two concepts and their use in the control applications in the automation industry. We develop a prototype in the industrial setup to explore the use of IoT devices that communicate with a cloud-based controller. Using the prototype, we perform a number of experiments to investigate the consequences of having a cloud server between the end device and the controller. Within this context we consider arbitrary jitter and delays, i.e., they can be smaller, equal or greater than the sampling periods. Moreover, we apply mitigation mechanisms to deal with the delays and jitter that are caused by the local and wide area networks (LAN and WAN).

  • 163.
    Nolte, Thomas
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Åsberg, Mikael
    Mälardalen University, School of Innovation, Design and Engineering.
    J. Bril, Reinder
    Mälardalen University, School of Innovation, Design and Engineering.
    Shin, Insik
    Mälardalen University, School of Innovation, Design and Engineering.
    Hierarchical Scheduling of Complex Embedded Real-Time Systems2009In: Ecole d'Ete Temps-REel (ETR'09), Paris, France, 2009, p. 129-142Conference paper (Refereed)
  • 164.
    Nolte, Thomas
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Shin, Insik
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Sjödin, Mikael
    Mälardalen University, School of Innovation, Design and Engineering.
    A Synchronization Protocol for Temporal Isolation of Software Components in Vehicular Systems2009In: IEEE Transactions on Industrial Informatics, ISSN 1551-3203, E-ISSN 1941-0050, Vol. 5, no 4, p. 375-387Article in journal (Refereed)
    Abstract [en]

    We present a method that allows for integration of individually developed functions of software components into a predictable real-time system. The method has been designed to provide a lightweight mechanism that gives temporal firewalls between functions, preventing unpredictable side effects during function integration. The method maps well to the AUTOSAR (AUTomotive Open System ARchitecture) software component model and can thus be used to facilitate seamless and predictable integration and isolation of AUTOSAR components that have been developed by different manufacturers. Specifically, this paper presents a protocol for synchronization in a hierarchical real-time scheduling framework. Using our protocol, a software component does not need to know, and is not dependent on, the timing behavior of software components belonging to other functions; even though they share mutually exclusive resources. In this paper, we also prove the correctness of our approach and evaluate its efficiency and cost in terms of system load in a vehicular context. 

  • 165.
    Papadopoulos, Alessandro
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Abbaspour Asadollah, Sara
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Ashjaei, Seyed Mohammad Hossein
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. Arcticus Systems AB, Järfälla, Sweden.
    Mubeen, Saad
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. Arcticus Systems AB, Järfälla, Sweden.
    Pei Breivold, Hongyu
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. ABB Corporate Research, Sweden.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    SLAs for Industrial IoT: Mind the Gap2017In: The 4th International Symposium on Inter-cloud and IoT (ICI 2017) ICI'17, 2017, p. 75-78Conference paper (Refereed)
    Abstract [en]

    Cloud computing and Internet of Things (IoT) are computing technologies that provide services to consumers and businesses, allowing organizations to become more agile and flexible. The potential business values that cloud consumers can achieve depend a lot on the quality of service in the provided cloud services. Therefore, ensuring the quality of service through service-level agreements (SLA) for such cloud-based services is crucial for both the service providers and service consumers. As SLA is critical for cloud deployments and wider adoption of cloud services, the management of SLA in cloud and IoT has thus become an important and essential issue. In this paper we provide an understanding of the current status and maturity level of SLA management in industrial IoT and academic efforts in this field. We also conduct a preliminary survey of current research on SLA management in order to identify open challenges and gaps that need to be addressed in future research directions. In particular, we investigate how to provide useful SLA management support adapted to the maturity level and current industrial practices, and shorten the gap between academia and industry.

  • 166.
    Salman, Chaudhary Awais
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. ABB AB, Västers, Sweden.
    Struhar, Vaclav
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Papadopoulos, Alessandro
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Fogification of industrial robotic systems: Research challenges2019In: IoT-Fog 2019 - Proceedings of the 2019 Workshop on Fog Computing and the IoT, Association for Computing Machinery, Inc , 2019, p. 41-45Conference paper (Refereed)
    Abstract [en]

    To meet the demands of future automation systems, the architecture of traditional control systems such as the industrial robotic systems needs to evolve and new architectural paradigms need to be investigated. While cloud-based platforms provide services such as computational resources on demand, they do not address the requirements of real-time performance expected by control applications. Fog computing is a promising new architectural paradigm that complements the cloud-based platform by addressing its limitations. In this paper, we analyse the existing robot system architecture and propose a fog-based solution for industrial robotic systems that addresses the needs of future automation systems. We also propose the use of Time-Sensitive Networking (TSN) services for real-time communication and OPC-UA for information modelling within this architecture. Additionally, we discuss the main research challenges associated with the proposed architecture.

  • 167.
    Sandström, Kristian
    et al.
    ABB Corporate Research.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    J. Bril, Reinder
    TU/e, Netherlands .
    On Jitter in Time Partitioned Real-Time Systems2012In: Emerging Technologies & Factory Automation (ETFA), 2012 IEEE 17th Conference on, 2012, p. 1-4Conference paper (Refereed)
    Abstract [en]

    Recent trends towards adopting hypervisors, hierarchical scheduling, and other virtualization technologies that achieve partitioned access to the CPU and other resources impose significant impact with respect to jitter performance in embedded real-time systems. In this paper we make a first step towards characterization, modeling and calculation of this jitter.

  • 168.
    Santos, R.
    et al.
    IEETA, University of Aveiro, Aveiro, Portugal.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Pedreiras, P.
    IEETA, University of Aveiro, Aveiro, Portugal.
    Almeida, L.
    University of Porto.
    Multi-level hierarchical scheduling in ethernet switches2011In: Embedded Syst. Week, ESWEEK - Proc. ACM Int. Conf. Embedded Softw., EMSOFT, 2011, p. 185-193Conference paper (Refereed)
    Abstract [en]

    The complexity of Networked Embedded Systems (NES) has been growing steeply, due to increases both in size and functionality, and is becoming a major development concern. This situation is pushing for paradigm changes in NES design methodologies towards higher composability and flexibility. Component-oriented design technologies, in particular supported by server-based scheduling, seem to be good candidates to provide the needed properties. As a response we developed a multi-level hierarchical serverbased architecture for Ethernet switches that provides composability and supports online adaptation and reconfiguration. This paper extends our work, presenting the associated response-time based schedulability analysis, necessary for the admission control procedure. Additionally, we have derived the temporal complexity of the analysis, which is shown to be O(n2), where n is the number of higher priority components associated with a given server. Finally, we present a proof-of-concept implementation and a set of experimental results that validates the analysis. Copyright © 2011 ACM.

  • 169.
    Santos, Rui
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Almeida, Luis
    Mälardalen University, School of Innovation, Design and Engineering.
    Pedreiras, Paulo
    Mälardalen University, School of Innovation, Design and Engineering.
    Schedulability Analysis for Multi-level Hierarchical Server Composition in Ethernet Switches2010In: 9th International Workshop on Real-Time Networks RTN'2010, Brussels, Belgium, 2010Conference paper (Refereed)
  • 170.
    Santos, Rui
    et al.
    IEETA / University of Aveiro Aveiro, Portugal.
    Pedreiras, Paulo
    IEETA / University of Aveiro Aveiro, Portugal.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Almeida, Luis
    University of Porto Porto, Portugal.
    A Demonstration of Hierarchical Scheduling over Ethernet2011In: Real-Time SystemS @ Work, the Open Demo Session of Real-Time Techniques and Technologies of the 32nd IEEE Real-Time Systems Symposium (RTSS'11), 2011Conference paper (Refereed)
  • 171. Santos, Rui
    et al.
    Pedreiras, Paulo
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Almeida, Luis
    Mälardalen University, School of Innovation, Design and Engineering.
    Demonstrating an Ethernet Switch Enhanced with Hierarchical Scheduling2011Conference paper (Refereed)
  • 172.
    Santos, Rui
    et al.
    University of Porto.
    Pedreiras, Paulo
    University of Aveiro.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Almeida, Luis
    Mälardalen University, School of Innovation, Design and Engineering.
    Hierarchical Server-based Traffic Scheduling in Ethernet Switches2010Conference paper (Refereed)
  • 173.
    Santos, Rui
    et al.
    University of Aveiro, Aveiro, Portugal .
    Pedreiras, Paulo
    University of Aveiro, Aveiro, Portugal .
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Almeida, Luis
    University of Porto, Porto, Portugal.
    Hierarchical server-based traffic scheduling in ethernet switches2011In: ACM SIGBED Review, ISSN 1551-3688, Vol. 8, no 1, p. 68-69Article in journal (Refereed)
    Abstract [en]

    Distributed Embedded Real-Time Systems (DERTS) are ever more complex, consisting of an increasing number of nodes with more functionality and handling more data. This scenario is pushing for paradigm changes in the methodologies to design complex DERTS. Namely, component-oriented design methodologies, exhibiting the composability property are considered an effective means to tackle the growing complexity of DERTS. Server-oriented architectures have proven to be an effective means to enable controlled resource sharing, providing composability among application components as well as between the application software and the hardware platform on which they execute.

  • 174.
    Sheuly, Sharmin Sultana
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bankarusamy, Sudhangathan
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Begum, Shahina
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Resource allocation in industrial cloud computing using artificial intelligence algorithms2015In: Frontiers in Artificial Intelligence and Applications, Volume 278, 2015, p. 128-136Conference paper (Refereed)
    Abstract [en]

    Cloud computing has recently drawn much attention due to the benefits that it can provide in terms of high performance and parallel computing. However, many industrial applications require certain quality of services that need efficient resource management of the cloud infrastructure to be suitable for industrial applications. In this paper, we focus mainly on the services, usually executed within virtual machines, allocation problem in the cloud network. To meet the quality of service requirements we investigate different algorithms that can achieve load balancing which may require migrating virtual machines from one node/server to another during runtime and considering both CPU and communication resources. Three different allocation algorithms based on Genetic Algorithm (GA), Particle Swarm Optimization (PSO) and Best-fit heuristic algorithm are applied in this paper. We evaluate the three algorithms in terms of cost/objective function and calculation time. In addition, we explore how tuning different parameters (including population size, probability of mutation and probability of crossover) can affect the cost/objective function in GA. Depending on the evaluation, it is concluded that algorithm performance is dependent on the circumstances i.e. available resource, number of VMs etc. 

  • 175.
    Shin, Insik
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Sjödin, Mikael
    Mälardalen University, School of Innovation, Design and Engineering.
    On Optimal Hierarchical Resource Sharing in Open Environments2008Report (Other academic)
    Abstract [en]

    This paper presents a new perspective in the context of supporting logical resource sharing under hierarchical scheduling. Our work is motivated from a tradeoff between reducing resource holding times and reducing system load (i.e., the collective processor requirements to guarantee the schedulability of hierarchical scheduling frameworks). We formulate an optimization problem that determines the resource holding times of each individual tasks (and therefore those of subsystems) with the goal of minimizing the system load subject to the system's schedulability. We present efficient algorithms to find an optimal solution to the problem, and we prove their correctness. 

  • 176. Shin, Insik
    et al.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Sjödin, Mikael
    Mälardalen University, School of Innovation, Design and Engineering.
    Synthesis of Optimal Interfaces for Hierarchical Scheduling with Resources 2008In: Proceedings of the 29th IEEE International Real-Time Systems Symposium (RTSS08)., 2008, p. 209-220Conference paper (Refereed)
    Abstract [en]

     

    This paper presents algorithms that (1) facilitate system independent synthesis of timing-interfaces for subsystems and (2) system-level selection of interfaces to minimize CPU load. The results presented are developed for hierarchical fixed-priority scheduling of subsystems that may share logical recourses (i.e., semaphores). We show that the use of shared resources results in a tradeoff problem, where resource locking times can be traded for CPU allocation, complicating the problem of finding the optimal interface configuration subject to schedulability. This paper presents a methodology where such a tradeoff can be effectively explored. It first synthesizes a bounded set of interface-candidates for each subsystem, independently of the final system, such that the set contains the interface that minimizes system load for any given  system. Then, integrating subsystems into a system, it finds the optimal selection of interfaces. Our algorithms have linear complexity to the number of tasks involved. Thus, our approach is highly suitable for adaptable and reconfigurable systems.

     

  • 177.
    Shin, Insik
    et al.
    Mälardalen University, Department of Computer Science and Electronics.
    Behnam, Moris
    Mälardalen University, Department of Computer Science and Electronics.
    Nolte, Thomas
    Mälardalen University, Department of Computer Science and Electronics.
    Sjödin, Mikael
    Mälardalen University, Department of Computer Science and Electronics.
    Towards Optimal Hierarchical Resource Sharing in Open Environments2007In: Proceedings of the Work-In-Progress (WIP) session of the 28th IEEE Real-Time Systems Symposium (RTSS'07), Tucson, AZ, USA, 2007, p. 57-60Conference paper (Refereed)
  • 178.
    Struhar, Vaclav
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Ashjaei, Seyed Mohammad Hossein
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Craciunas, Silviu
    Papadopoulos, Alessandro
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    DART: Dynamic Bandwidth Distribution Framework for Virtualized Software Defined Networks2019In: IEEE 45th Annual Conference of the Industrial Electronics Society IECON'19, 2019Conference paper (Refereed)
  • 179.
    Struhar, Vaclav
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Papadopoulos, Alessandro
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Work-in-Progress: Fog Computing for Adaptive Human-Robot Collaboration2018In: International Conference on Embedded Software 2018 EMSOFT2018, 2018, article id 8537213Conference paper (Refereed)
    Abstract [en]

    Fog computing is an emerging technology that enables the design of novel time sensitive industrial applications. This new computing paradigm also opens several new research challenges in different scientific domains, ranging from computer architectures to networks, from robotics to real-time systems. In this paper, we present a use case in the human-robot collaboration domain, and we identify some of the most relevant research challenges.

  • 180.
    Tsog, Nandinbaatar
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Becker, Matthias
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bruhn, Fredrik
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Nolin, Mikael
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Static Allocation of Parallel Tasks to Improve Schedulability in CPU-GPU Heterogeneous Real-Time Systems2019Conference paper (Refereed)
    Abstract [en]

    Autonomous driving is one of the main challenges of modern cars. Computer visions and intelligent on-board decision making are crucial in autonomous driving and require heterogeneous processors with high computing capability under low power consumption constraints. The progress of parallel computing using heterogeneous processing units is further supported by software frameworks like OpenCL, OpenMP, CUDA, and C++AMP. These frameworks allow the allocation of parallel computation on different compute resources. This, however, creates a difficulty in allocating the right computation segments to the right processing units in such a way that the complete system meets all its timing requirements. In this paper, we consider pre-runtime static allocations of parallel tasks to perform their execution either sequentially on CPU or in parallel using a GPU. This allows for improving any unbalanced use of GPU accelerators in a heterogeneous environment. By performing several heuristic algorithms, we show that the overuse of accelerators results in a bottle-neck of the entire system execution. The experimental results show that our allocation schemes that target a balanced use of GPU improve the system schedulability up to 90%.

  • 181.
    Tsog, Nandinbaatar
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Becker, Matthias
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Larsson, Marcus
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bruhn, Fredrik
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Sjödin, Mikael
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. Malardalen Univ, Sch Innovat Design & Engn, DPAC Res Profile, Vasteras, Sweden..
    Poster Abstract: Real-Time Capabilities of HSA Compliant COTS Platforms2016In: PROCEEDINGS OF 2016 IEEE REAL-TIME SYSTEMS SYMPOSIUM (RTSS), 2016, p. 364-364Conference paper (Refereed)
    Abstract [en]

    During recent years, the interest in using heterogeneous computing architecture in industrial applications has increased dramatically. These architectures provide the computational power that makes them attractive for many industrial applications. However, most of these existing heterogeneous architectures suffer from the following limitations: difficulties of heterogeneous parallel programming and high communication cost between the computing units. To overcome these disadvantages, several leading hardware manufacturers have formed the HSA Foundation to develop a new hardware architecture: Heterogeneous System Architecture (HSA). In this paper, we investigate the suitability of using HSA for real-time embedded systems. A preliminary experimental study has been conducted to measure massive computing power and timing predictability of HSA.

  • 182.
    Tsog, Nandinbaatar
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Nolin, Mikael
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bruhn, Fredrik
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Intelligent Data Processing using In-Orbit Advanced Algorithms on Heterogeneous System Architecture2018In: IEEE Aerospace Conference 2018 IEEEAC2018, 2018, p. 1-8Conference paper (Refereed)
    Abstract [en]

    In recent years, commercial exploitation of small satellites and CubeSats has rapidly increased. Time to market of processed customer data products is becoming an important differentiator between solution providers and satellite constellation operators. Timely and accurate data dissemination is the key to success in the commercial usage of small satellite constellations which is ultimately dependent on a high degree of autonomous fleet management and automated decision support. The traditional way for disseminating data is limited by on the communication capability of the satellite and the ground terminal availability. Even though cloud computing solutions on the ground offer high analytical performance, getting the data from the space infrastructure to the ground servers poses a bottleneck of data analysis and distribution. On the other hand, adopting advanced and intelligent algorithms onboard offers the ability of autonomy, tasking of operations, and fast customer generation of low latency conclusions, or even real-time communication with assets on the ground or other sensors in a multi-sensor configuration. In this paper, the advantages of intelligent onboard processing using advanced algorithms for Heterogeneous System Architecture (HSA) compliant onboard data processing systems are explored. The onboard data processing architecture is designed to handle a large amount of high-speed streaming data and provides hardware redundancy to be qualified for the space mission application domain. We conduct an experimental study to evaluate the performance analysis by using image recognition algorithms based on an open source intelligent machine library 'MIOpen' and an open standard 'OpenVX'. OpenVX is a cross-platform computer vision library.

  • 183.
    Van Den Heuvel, M. M. H. P.
    et al.
    Technische Universiteit Eindhoven, Netherlands .
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bril, Reinder J.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Lukkien, Johan J.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Optimal and fast composition of resource-sharing components in hierarchical real-time systems2014In: RTCSA 2014 - 20th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications, 2014, p. Article number 6910547-Conference paper (Refereed)
    Abstract [en]

    In this paper we consider various flavors of the stack resource policy (SRP) for arbitrating access to shared resources in a hierarchical scheduling framework (HSF) upon a uni-processor. We propose algorithms for exploring and selecting the (local) resource ceilings within components, such that it results in an optimal composition of resource-sharing components in an HSF. Existing methods are non-optimal, because (i) they optimize just the length of global non-preemptive execution of tasks and (ii) they do not detect whether or not resources are shared globally (i.e., between tasks of different components). Lifting these limitations leads to an exponential growth of the design space. This paper contributes a fast three-step methodology which lifts these limitations, i.e., we apply the SRP at each level of the HSF to just the resources being shared. Our algorithm selects those component interfaces (i.e., by fixing the local resource ceilings of each component) that minimize the system load.

  • 184.
    van den Heuvel, Martijn
    et al.
    Technische Universiteit Eindhoven, the Netherlands.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    J. Bril, Reinder
    Technische Universiteit Eindhoven, the Netherlands.
    Lukkien, Johan
    Technische Universiteit Eindhoven, the Netherlands.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Opaque Analysis for Resource Sharing in Compositional Real-Time Systems2011In: 4th Workshop on Compositional Theory and Technology for Real-Time Embedded Systems (CRTS'11), 2011Conference paper (Refereed)
    Abstract [en]

    In this paper we propose opaque analysis methods to integrate dependent real-time components into hierarchical fixed-priority scheduled systems. To arbitrate mutually exclusive resource access between components, we consider two existing protocols: HSRP - comprising overrun with and without payback - and SIRAP. An opaque analysis allows to postpone the choice of a synchronization protocol until component integration time. First, we identify the sources of pessimism in the existing analysis techniques and we conclude that both protocols assume different models in their local analysis. In particular, the compo- sitional analysis for overrun with payback (OWP) is not opaque and is pessimistic. The latter makes OWP expensive compared to its counter part without a payback mechanism (ONP). This paper presents an opaque and less pessimistic OWP analysis. Secondly, SIRAP requires more timing information to perform a task-level schedulability analysis. In many practical situations, however, detailed timing characteristics of tasks are hard to obtain. We introduce an opaque analysis for SIRAP using the analysis of ONP to reduce the required timing information during the local analysis. We show that the analysis for ONP cannot deem systems schedulable which are infeasible with SIRAP. The SIRAP analysis may therefore reduce the required system resources of a component by sacrificing the choice for an arbitrary synchronization protocol at system integration time.

  • 185.
    van den Heuvel, Martijn
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    J. Bril, Reinder
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Extending an HSF-enabled Open Source Real-Time Operating System with Resource Sharing2010In: Proceedings of the 6th International Workshop on Operating Systems Platforms for Embedded Real-Time Applications, Brussels, Belgium, 2010Conference paper (Refereed)
  • 186.
    van den Heuvel, Martijn
    et al.
    TU/e, The Netherlands.
    J. Bril, Reinder
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Lukkien, Johan
    TU/e, The Netherlands.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Uniform Interfaces for Resource-Sharing Components in Hierarchically Scheduled Real-Time Systems2016In: Real-Time Systems, InTech , 2016Chapter in book (Other academic)
  • 187.
    Vulgarakis, A.
    et al.
    Industrial Software Systems, ABB Corporate Research, Västerås, Sweden .
    Shooja, R.
    Mälardalen University, School of Innovation, Design and Engineering.
    Monot, A.
    Industrial Software Systems, ABB Corporate Research, Baden-Dättwil, Switzerland .
    Carlson, Jan
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Task synthesis for control applications on multicore platforms2014In: ITNG 2014 - Proceedings of the 11th International Conference on Information Technology: New Generations, 2014, p. 229-234Conference paper (Refereed)
    Abstract [en]

    Multicore processors promise to improve the performance of systems, by integrating more and more cores onto a single chip. Existing software systems, such as control software from the automation domain, need adjustments to be adapted on multicores. To exploit the concurrency offered by multicore processors, appropriate algorithms have to be used to divide the control application software into tasks, and tailored task partitioning and scheduling approaches are required to increase the overall performance. In this paper we present a model-driven approach for automatic synthesis and deployment of control applications on multicore processors. The approach is centeredaround a system model, which describes the control applications, the multicore platform, as well as the mapping between the two. We apply the approach on a number of control applications out of which we synthesize tasks and present their run-time behavior in a real-time operating system.

  • 188.
    Yang, Jinsong
    et al.
    ABB Corporate Research.
    Sandström, Kristian
    ABB Corporate Research.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Data Distribution Service for Industrial Automation2012In: IEEE Symposium on Emerging Technologies and Factory Automation, ETFA, 2012, p. Art.nr: 6489544-Conference paper (Refereed)
    Abstract [en]

    The IEC 61499 is an open standard for the next generation of distributed control and automation. Data Distribution Service for Real-Time Systems (DDS) is a specification of a publish/subscribe middleware for distributed systems, created by the Object Management Group (OMG) to standardize a data-centric publish-subscribe programming model for distributed systems. This paper evaluates the DDS communication performance based on a model built within the IEC 61499 standard and compares it with the traditional socket based solution for communication. According to the test results, the DDS communication has the potential to reduce the complexity and is suggested as a suitable solution for some classes of industrial control systems.

  • 189.
    Yekeh, Farahnaz
    et al.
    Umeå University, Umeå.
    Pordel, Mostafa
    Umeå University, Umeå.
    Almeida, Luis
    University of Porto, Porto, Portugal .
    Behnam, Moris
    University of Porto, Porto, Portugal .
    Portugal, Paulo José
    University of Porto, Porto, Portugal .
    Exploring alternatives to scale FTT-SE to large networks2011In: SIES 2011 - 6th IEEE International Symposium on Industrial Embedded Systems, Conference Proceedings, 2011, p. 107-110Conference paper (Refereed)
    Abstract [en]

    Nowadays, most complex embedded systems follow a distributed approach in which a network interconnects potentially large numbers of nodes. One technology that is being increasingly used is switched Ethernet, but real-time variants of this protocol typically limit scalability. In this paper, we focus on the scalability of the Flexible Time Triggered communication over Switched Ethernet (FTT-SE), which has been proposed to support hard real-time applications in a flexible and predictable manner. Moreover, time-triggered and event-triggered communication methods are supported in this protocol. FTT-SE has already been explored and investigated for small scale networked applications. In this paper we address the protocol scalability and suggest three different solutions with a qualitative assessment.

  • 190.
    Zahid, I.
    et al.
    University of Porto, Porto, Portugal.
    Almeida, L.
    University of Porto, Porto, Portugal.
    Ashjaei, Seyed Mohammad Hossein
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    On the efficiency of sporadic servers on ethernet with FTT-SE2017In: SIGBED Review, ISSN 1551-3688, Vol. 14, no 3, p. 32-34Article in journal (Refereed)
  • 191.
    Åsberg, Mikael
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nemati, Farhang
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Towards Hierarchical Scheduling in AUTOSAR2009In: Proceedings of 14th IEEE International Conference on Emerging Techonologies and Factory (ETFA'09), 2009Conference paper (Refereed)
    Abstract [en]

    AUTOSAR [17] is a partnership between automotive manufactures and suppliers. It aims at standardizing the automotive software architecture and separating software and hardware. This approach makes software more independent, maintainable, reuseable, etc. Still there is much work to do in order for this standard to be usable. This paper focus on automotive software integration in AUTOSAR, with the use of hierarchical scheduling as an enabling technology. At this point, AUTOSARcomponents do not have any timing relation with its tasks [19, 20]. This causes an unpredictive runtime behavior which can only be analyzed and verified after integration phase. We will discuss how integration can be done in AUTOSAR, with runtime temporal isolation of components. This will enable schedulability analysis at the level of components rather than at the level of tasks.

  • 192.
    Åsberg, Mikael
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    An Experimental Evaluation of Synchronization Protocol Mechanisms in the Domain of Hierarchical Fixed-Priority Scheduling2013In: ACM International Conference Proceeding Series, 2013, 2013, p. 77-85Conference paper (Refereed)
    Abstract [en]

    This paper presents an extensive implementation study where we evaluate and compare different synchronization protocol mechanisms within the domain of two-level hierarchical fixed-priority preemptive scheduling. These protocol mechanisms include HSRPnP (Hierarchical Stack Resource Policy no Payback), HSRPwP (Hierarchical Stack Resource Policy with Payback), SIRAP (Subsystem Integration and Resource Allocation Policy), RRP (Rollback Resource Policy) and SRPwD (Stack Resource Policy with Donation). In an attempt to shed new light to the research in this area, we focus on the actual software implementation of these protocols in a widely used real-time operating system (VxWorks). This study is not based on worst-case schedulability analysis which is the most common angle of work in this research field. All five protocols have been implemented, tested and executed for several months with many different parameters, for example; variant number of subsystems, number of resources, system utilization settings, resource allocation strategies etc. These tests generated a large amount of useful data, for example, protocol overhead, effective subsystem utilization, number of protocol mechanism invocations etc. Due to the large complexity and size of this data, we analyzed the data with state-of-the-art statistical methods and tools (Principal Component Analysis) in order to grasp the efficiency of the protocols with respect to a large number of different parameters.

  • 193.
    Åsberg, Mikael
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    J. Bril, Reinder
    Technische Universiteit Eindhoven.
    Implementation of Overrun and Skipping in VxWorks2010In: Proceedings of the 6th International Workshop on Operating Systems Platforms for Embedded Real-Time Applications, Brussels, Belgium, 2010Conference paper (Refereed)
  • 194.
    Åsberg, Mikael
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering.
    Resource sharing using the rollback mechanism in hierarchically scheduled real-time open systems2013In: Real-Time Technology and Applications - Proceedings, 2013, p. 129-140Conference paper (Refereed)
    Abstract [en]

    In this paper we present a new synchronization protocol called RRP (Rollback Resource Policy) which is compatible with hierarchically scheduled open systems and specialized for resources that can be aborted and rolled back. We conduct an extensive event-based simulation and compare RRP against all equivalent existing protocols in hierarchical fixed priority preemptive scheduling; SIRAP (Subsystem Integration and Resource Allocation Policy), OPEN-HSRPnP (open systems version of Hierarchical Stack Resource Policy no Payback) and OPEN-HSRPwP (open systems version of Hierarchical Stack Resource Policy with Payback). Our simulation study shows that RRP has better average-case response-times than the state-of-the-art protocol in open systems, i.e., SIRAP, and that it performs better than OPEN-HSRPnP/OPEN-HSRPwP in terms of schedulability of randomly generated systems. The simulations consider both resources that are compatible with rollback as well as resources incompatible with rollback (only abort), such that the resource-rollback overhead can be evaluated. We also measure CPU overhead costs (in VxWorks) related to the rollback mechanism of tasks and resources. We use the eXtremeDB (embedded real-time) database to measure the resource-rollback overhead.

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