salle A. Turing CE4
18 March 2013 - 14h00
Scheduling and Analysis of Cyclic Mode-Switches
by Wang Yi from Uppsala University
Abstract: We propose to structure the global behavior of real-time systems using modes and mode switches. In each mode, a system is executing a set of real-time tasks generating resource requests; a mode switch may be triggered at any time by internal software or hardware errors, or external events. During a mode switch, the pending requests generated in the source mode should be handled in the target mode according to a mode change protocol. We show that many systems can be modeled in this setting. For instance, mixed-criticality systems constitute typically a chain (or a DAG) of mode switches where each mode corresponds to a criticality level. The technical challenge is how to schedule the dynamically released resource requests in such systems in order to guarantee that no timing constraints will be violated.
In previous work [ECRTS 2012, RTS 2013, Ekberg & Yi], we have developed techniques for systems with acyclic mode-switches. In this talk, I will present a new technique to solve the scheduling and analysis problems for cyclic mode-switches, that may be described using any directed graph.