Section: Research Program

Deciding the schedulability of all programs running within the same cyber component

In this context, the programs may have different time criticalities, but they share the same processor, possibly multicore (This case is referred as a mixed criticality approach.). Our objective is to propose a solution composing probabilistic and non-probabilistic approaches based on answers to the following scientific challenges:

1. scheduling algorithms taking into account the interaction between different variability factors. The proposed scheduling algorithms are the theoretical bases of a scheduler able to guarantee the time constraints of the cyber component. The existence of time parameters described by probability distributions imposes to answer to the challenge of revisiting scheduling algorithms that lose their optimality even in the case of an unicore processor [26]. Moreover, the multicore partionning problem is, also, recognized difficult for the non-probabilistic case [29];

2. schedulability analyses based on the algorithms proposed previously. In the case of predictable processors, the schedulability analyses accounting for operating systems costs increase the dependability of CPSs [28]. Morever, in presence of variability factors, the additivity property of non-probabilistic approaches is lost and new composition principles are required. We will propose new composition principles based on our preliminary results on the propagation of the probabilistic constraints [16]. The definition of these principles form the challenge related to this objective.