Schedulability using native non-preemptive groups on an AUTOSAR/OSEK platform

To combine the relative strengths of fully preemptive and non-preemptive fixed priority scheduling, we can use limited preemptive scheduling methods. One such method is fixed-priority threshold scheduling (FPTS). This approach defines dual priorities for every task, a priority assigned to the inactive jobs and an equal or a higher one, called preemption threshold, for the jobs that have already started executing. A task can preempt another task´s job if and only if its priority is greater than the other task´s preemption threshold. FPTS can be implemented by assigning tasks to non-preemptive groups in a one-to-many manner. That is groups of tasks that are mutually non-preemptive.