实时操作系统μC/OS-Ⅱ的多任务改进方法

A Novel Method for Multitask Support on Real-time Operating System μC/OS-Ⅱ

文章针对实时操作系统μC/OS-Ⅱ中调度函数使用的查找表空间复杂度高而导致μC/OS-Ⅱ仅能支持一定数目(64个)任务的问题,提出了一种改进的查找表结构及其相应的查找方法,使查找表空间复杂度由O(2n)降为O(2n/2),同时保证时间复杂度仍为O(1),实现了μC/OS-Ⅱ的多任务改进。采用该文的方法,可以在基本不增加现有μC/OS-Ⅱ存储大小的情况下,使μC/OS-Ⅱ支持到256个任务。

As a kind of real time operating system,the schedule function in μC/OS-Ⅱ has the O(1)time complexity and the O(2n)space complexity by using the bit vector and lookup table.Because the lookup table has too high space complexity,only 64 tasks can be supported in μC/OS-Ⅱ.In this paper,a improved lookup table with O(2n/2)space complexity and the corresponding lookup method with O(1)time complexity are presented.Using method,more tasks than 64 can be supported in μC/OS-Ⅱ without more space demand.