Schedulability analysis for fault-tolerant group-based preemptive scheduling

The group‐based preemptive scheduling provides a flexible mechanism to define the preemptive relations between tasks. However, this scheduling scheme together with a resource access synchronization protocol and the requirements of fault tolerance makes the predication of a real‐time system’s behaviors more difficult than traditional scheduling scheme. The major contribution of this work is an algorithm to calculate the worstcase response time for tasks under the group‐based preemptive scheduling. This algorithm supports both the fault‐free and the primary‐alternative fault‐tolerance scheduling mechanism. Moreover, a method to calculate the minimum allowed time between two consecutive faults is also introduced. The algorithm has been implemented in a time analysis tool and integrated into a system development platform, which is compatible with the OSEK/VDX operating system standard, to verify the temporal property in the early system design step.