Serge Midonnet

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In this paper, we focus on the scheduling of periodic fork-join real-time tasks on multiprocessor systems. Parallel real-time tasks in the fork-join model have strict parallel segments without laxity. We propose a partitioned scheduling algorithm which increases the laxity of the parallel segments and therefore the schedulability of tasksets of this model.(More)
Parallelism is becoming more important nowadays due to the increasing use of multiprocessor systems. In this paper, we study the problem of scheduling periodic parallel real-time Directed Acyclic graph (DAG) tasks on m homogeneous multiprocessor systems. A DAG task is an example of inter-subtask parallelism. It consists of a collection of dependent subtasks(More)
The new generation of embedded systems will have the capability to harvest energy from the environment. The electrical energy which is available to power these devices changes over time and is limited by the size of the energy storage unit such as battery or capacitor and the size of the harvester such as a solar panel. In order to cope with this(More)
In this paper, we consider parallel real-time tasks following a Directed Acyclic Graph (DAG) model. This task model is classical in embedded and industrial system applications. Each real-time task is defined by a set of subtasks under precedence constraints. With each subtask being associated a worst case execution time and a maximal degree of parallelism.(More)
After having drawn up a state of the art on the theoretical feasibility of a system of periodic tasks scheduled by a preemptive algorithm at fixed priorities, we show in this article that temporal faults can occur all the same within a theoretically feasible system, that these faults can lead to a failure of the system and that we can use the data(More)
The Segment Stretch Transformation (SST) is an algorithm that transforms parallel Fork-Join (FJ) tasks into sequential tasks on multiprocessor systems when possible, in order to increase the schedulability of the tasksets of this model. SST is based on Task Stretch Transformation (TST) which is a transformation for the same model of tasks, but it uses(More)
In this paper, we study the problem of real-time scheduling of parallel tasks represented by a Directed Acyclic Graph (DAG) on multiprocessor architectures. We focus on Global Earliest Deadline First scheduling of sporadic DAG tasksets with constrained-deadlines on a system of homogeneous processors. Our contributions consist in analyzing DAG tasks by(More)
We address in this paper the problem of jointly scheduling hard periodic tasks and soft aperiodic events using the Real-Time Specification for Java (RTSJ). We present the programming constraints of RTSJ and propose slack time evaluation and utilization algorithms which take these constraints into account. We evaluate these algorithms and compare their(More)