TinyOS中DSA调度策略的研究

针对TinyOS任务调度采用非剥夺的先来先服务调度策略，而产生的系统紧急任务不能及时得到响应及节点吞吐量下降情况，该文提出一种新的可抢占时限短作业调度策略——DSA。在绝对时限前执行硬实时任务，满足了系统对实时任务的响应要求，提高处理器的响应速度，对软实时任务实行短作业优先调度策略，提高系统的吞吐量。在TinyOS上测试表明，DSA策略在不影响TinyOS原有性能的情况下，改进了传感器网络承担实时性任务的运行效果。

Research on DSA Scheduling Strategy in TinyOS

TinyOS task scheduling is based on first-come-first-served non-preempting strategy, which is not able to give emergency tasks quick response, and throughput of nodes is lower. To address this issue, this paper proposes a new preempting algorithm, Deadline Short Algorithm(DSA): Through executing hard real-time tasks within an absolute deadline time limit, it meets system requirement for the real-time response, and improves processor’s response speed. Through executing soft real-time tasks based on shortest-job-first scheduling priority strategy, system throughput is increased. Test result indicates that with more nodes of wireless sensor network, though energy consumption has a little bit increase, it provides a high real-time performance and high throughput, avoiding network congestion.