In a preemptive priority based RTOS, priority inversion problem is among the major sources of deadline violations. Priority inheritance protocol is one of the approaches to reduce priority inversion. Unfortunately, RTOS like uC/OS can’t support priority inheritance protocol since it does not allow kernel to have multiple tasks at the same priority. Although it has different ways to avoid priority inversion such as priority ceiling protocol, developers still have some difficulties in programming real time applications with it. In this paper, we redesign the uC/OS kernel to provide the ability to support round robin scheduling and implement priority inheritance semaphore on the modified kernel. As result, we port new kernel with priority inheritance semaphore to evaluation board, and evaluate the execution time of each of the kernel service as well as verify the operations of our implementation.
标签： priority preemptive inversion problem
上传时间： 2015-12-14
上传用户：气温达上千万的
μC/OS从1992年开始为人们熟悉，到现在已经发展为μC/OS-II。ΜC/OS-II最多支持56个任务，其内核为占先式，总是执行就绪态的优先级最高的任务，并支持semaphore（信号量）、Mailbox（邮箱）、Message Queue(消息队列)等多种常用的进程间通信机制。与大多商用RTOS不同的是，μC/OS-II公开所有的源代码，并可以免费获得，对商业应用收取少量License费用。
上传时间： 2016-03-11
上传用户：希酱大魔王
The main purpose of this project is to add a new scheduling algorithm to GeekOS and to implement a simple synchronization primitive (semaphore). As you might have already noticed, GeekOS uses a simple priority based preemptive Round Robin algorithm. In this project, you will change this to a multilevel feedback scheduling. In addition, you will provide user programs with semaphores, a means to check the system s current time and a mechanism for passing command-line arguments
标签： scheduling algorithm implement to
上传时间： 2013-11-27
上传用户：Late_Li
VC++进程线程实例：EVENT，MUTEX，MUTITHREAD，PROCESS，semaphore，THREAD，UITHREAD，WORKERTHREAD
上传时间： 2013-12-10
上传用户：chongcongying
MINIX操作系统的内核修改补丁，增加了实时调度，迷你文件系统，semaphore系统服务。
上传时间： 2013-12-31
上传用户：zhangyigenius
包含 等待函数WaitForSingleObject 多线程同步之 Event (事件对象) 多线程同步之 Mutex (互斥对象) 多线程同步之 semaphore (信号对象) 多线程同步之 WaitableTimer (等待定时器对象) 等等
标签： Delphi多线程编程
上传时间： 2016-02-22
上传用户：西西王阿
