一种实时多任务调度方法的设计

在实时多任务系统中，当子任务的参数部分或全部相同、或子任务间存有某些约束关系时，仅由参数确定优先级会造成子任务的优先级难以区分或引起误操作，针对上述问题提出了一种以任务的关键性、价值密度为主，加入任务间约束关系的名为关键性一价值密度一任务约束的实时多任务调度方法，并给出了优先级设计规则。通过在一远程监控系统中的应用证实，该方法能体现实时任务的关键性、价值密度和任务间简单约束关系，避免了优先级相同和误操作现象，特别当任务过载时能使任务有序执行。

Design for Real-time Multi-task Scheduling Method

In real-time multi-task system, when the part or all parameters of subtasks are the same, or there are some constraint relations among subtasks, the priority determined only by the parameters will make the priority of subtask difficult to be distinguished or cause error operations, for the above problems, a real-time multi-task scheduling method, taking the key and value-density of task as main part and adding the constraint relations among tasks, named key--value-density--task constraint is proposed, and the design rule of priority is given. The method used in a long-distance monitor system approves that it can reflect the key and value-density of real-time task and simple constraint relations among tasks, avoid the same priorities and error operations. Especially, when the tasks are overloaded the method can make the tasks executed orderly.