关键词: 软实时, 调度算法, 周期任务, 实时系统

Abstract: A key problem of real-time operating systems is real-time scheduling policy. Based on the research of Dynamic Window-Constrained Scheduling (DWCS), a periodic window-constrained real-time model with mutual frames was proposed. Firstly, the mode was analyzed and some conclusions about the schedulability of this model were got. In succession, a Dynamic Dual-Window-Constrained Scheduling(DDWCS) was proposed which use the characteristic of mutual frames to improve the schedulability of this model. To evaluate the performance of the new algorithm, extensive simulation studies have been done. These simulations apply DWCS algorithm to schedule the periodic window-constrained real-time model with mutual frames and use it as a baseline to compare with the proposed algorithm. Simulation results show that the new algorithm is better than the old algorithm.

Key words: soft real-time, scheduling algorithms, periodic tasks, real-time systems