提出了一种新的用于开放式系统的调度机制,即二维优先级实时调度,它不仅划分任务优先级,还划分调度策略优先级.任务的执行顺序由其调度策略优先级和任务优先级共同决定.它不仅可以解决传统优先级调度机制中机制与调度策略不能相分离的问题,还提高了效率.这种机制中引入的CPU带宽控制策略,可以根据需要实现硬实时、软实时、混合实时不同目标的实时系统,并简化了任务可调度性分析,且可以为不同权限或级别的用户提供不同QoS服务.这种调度架构不仅效率高,而且具有很强的开放性,适用广、易扩展.
A novel scheduling scheme, called Two-Dimensional Priority Real-Time Scheduling (TDPRTS), is proposed for open systems. This scheme not only sets task priority, but also sets scheduling policy priority. The execution order of task is determined by both task priority and its scheduling policy priority. It can not only separate scheduling mechanism from scheduling policy but also improves the performance. This scheme also introduces the CPU bandwidth control so as to realize different real time systems with different goals, such as hard, soft and hybrid real time systems. It also simplifies the schedulability analysis of the tasks, and it can provide the services with different QoS to the users with different rights and levels. This mechanism has high efficiency and high open degree. It can be used to extensive fields and has high extensibility.