实时系统中的优先级继承

Priority Inheritance Protocol in Real-Time System

优先级继承协议可解决实时系统中优先级反转。多数支持优先级继承的嵌入式实时操作系统,要求释放资源的顺序与获得资源的顺序相反。当允许资源可按任何顺序释放时,若一个任务拥有多个共享资源,优先级被提升多次。释放资源时,任务优先级须调节适当,否则将导致非受限的优先级反转。解决优先级反转的最好方法是通过详细的系统设计,以避免优先级反转。

The priority inversion in real-time system is solved with priority inheritance protocol. Most of the embedded real-time operation systems supported the priority inheritance require that the order of releasing resource is mutually inversed with the order of acquiring resource. When the resources ate allowed to release in any order, if a task has multiple sharing resources, priority of task is hoisted many times. When the resource was released, the priority of task was adjusted to the appropriate level. Otherwise, unbounded priority inversion was brought on. The best solution to priority inversion is that the priority inversion is avoided by precise design of system.