HLC-PCP: A resource synchronization protocol for certifiable mixed criticality scheduling

• We propose HLC-PCP (Highest-Locker Criticality, Priority-Ceiling Protocol), which extends the well-known Priority Ceiling Protocol (PCP) to be applicable to AMC (Adaptive Mixed-Criticality), a variant of MCS. We present methods for worst-case blocking time computation with HLC-PCP, used for schedulability analysis of AMC with resource sharing, for both the dual-criticality model and the general multi-criticality model. This helps relax one of the key limiting assumptions of most MCS work, that is, tasks with different levels of criticality do not have common shared resources.

Today’s safety-critical Cyber-Physical Systems (CPS) often need to integrate multiple diverse applications with varying levels of importance, or criticality. Mixed-Criticality Scheduling (MCS) has been proposed with the objectives of achieving certification at multiple criticality levels and efficient utilization of hardware resources. Current work on MCS typically assumes tasks at different criticality levels are independent and do not share any resources (data). We propose HLC-PCP (Highest-Locker Criticality, Priority-Ceiling Protocol), which extends the well-known Priority Ceiling Protocol (PCP) to be applicable to AMC (Adaptive Mixed-Criticality), a variant of MCS. We present methods for worst-case blocking time computation with HLC-PCP, used for schedulability analysis of AMC with resource sharing, for both the dual-criticality model and the general multi-criticality model.