Scheduling the Asynchronous Fixed-Priority tasks with Preemption Threshold

Fixed-priority with preemption threshold (FPPT) is an important form of real-time scheduling algorithm. However, most of current research works concerning FPPT assume the task priorities are predefined and have a task model which constraints all tasks are released simultaneously. This presumption is too pessimistic. The major contribution of this paper is an appropriate schedulability analysis, based on response time analysis, for supporting FPPT scheduling on asynchronous task set in hard real-time systems. The simulation result illustrate that our approach can improve the breakdown utilization of asynchronous task set by 5%-27%.