Task Scheduling Algorithm for Heterogeneous Real-time Systems Based on Deadline Constraints

With the wide application of real-time information processing systems, real-time task scheduling in heterogeneous environments has become the most important research area. According to the processing stage and urgency of tasks, a task scheduling algorithm for heterogeneous real-time systems based on deadline constraints(DCSA) is proposed. Firstly, according to the free time of the ready tasks and the estimated execution time of each node in the system, the classified scheduling strategy is adopted to guarantee the priority of the emergency tasks. Then, different task switching strategies are proposed respectively corresponding to the assigned tasks and the relative deadlines of execution tasks in the processing nodes. The analysis shows that the algorithm can avoid the thrashing of scheduling system, and there is no case that other suspended tasks miss deadlines due to long waiting time, which effectively guarantees the successful-scheduled tasks ratio.