By thorough research on the prominent periodic and aperiodic scheduling algorithms,anon-line hard real-time scheduler is presented,which is applicable to the scheduling of packets over a link.This scheduler,based on b...By thorough research on the prominent periodic and aperiodic scheduling algorithms,anon-line hard real-time scheduler is presented,which is applicable to the scheduling of packets over a link.This scheduler,based on both Rate Monotonic,pinwheel scheduling algorithm Sr and Polling Serverscheduling algorithms,can rapidly judge the schedulability and then automatically generate a bus tablefor the scheduling algorithm to schedule the packets as the periodic packets.The implementation of thescheduler is simple and easy to use,and it is effective for the utilization of bus link.The orderly executionof the bus table can not only guarantee the performance of the hard real time but also avoid the blockageand interruption of the message transmission.So the scheduler perfectly meets the demand of hard real-time communication system on the field bus domain.展开更多
Guaranteed scheduling is necessary for hard real time systems, because each process of them must meet their deadline, or a serious consequence will result.In this paper we discuss two guaranteed schedule algorithms:ba...Guaranteed scheduling is necessary for hard real time systems, because each process of them must meet their deadline, or a serious consequence will result.In this paper we discuss two guaranteed schedule algorithms:backtracking and branch and bound,introduce the process to find the optimal solution by both methods,propose the concept of logical node and physical node.Through some experiments for different process sets,we have made comparisons between the two algorithms in branch nodes,comparing time,topology of the search tree,memory size needed,etc.展开更多
提出了一种实时异构系统的集成动态调度算法.该算法通过一个新的任务分配策略以及软实时任务的服务质量QoS(quality of service)降级策略,不仅以统一方式完成了对实时异构系统中硬、软实时任务的集成动态调度,而且提高了算法的调度成功...提出了一种实时异构系统的集成动态调度算法.该算法通过一个新的任务分配策略以及软实时任务的服务质量QoS(quality of service)降级策略,不仅以统一方式完成了对实时异构系统中硬、软实时任务的集成动态调度,而且提高了算法的调度成功率.同时,还进行了大量的模拟研究.这些模拟以传统的近视算法为基准,将其应用在实时异构系统集成动态调度时的调度成功率与新算法进行比较,模拟结果表明,在多种任务参数取值下,新算法的调度成功率均高于传统的近视算法.展开更多
基金Supported by the Emphases Science and Technology Project Foundation of Sichuan Province(NO.02GG006-037)
文摘By thorough research on the prominent periodic and aperiodic scheduling algorithms,anon-line hard real-time scheduler is presented,which is applicable to the scheduling of packets over a link.This scheduler,based on both Rate Monotonic,pinwheel scheduling algorithm Sr and Polling Serverscheduling algorithms,can rapidly judge the schedulability and then automatically generate a bus tablefor the scheduling algorithm to schedule the packets as the periodic packets.The implementation of thescheduler is simple and easy to use,and it is effective for the utilization of bus link.The orderly executionof the bus table can not only guarantee the performance of the hard real time but also avoid the blockageand interruption of the message transmission.So the scheduler perfectly meets the demand of hard real-time communication system on the field bus domain.
文摘Guaranteed scheduling is necessary for hard real time systems, because each process of them must meet their deadline, or a serious consequence will result.In this paper we discuss two guaranteed schedule algorithms:backtracking and branch and bound,introduce the process to find the optimal solution by both methods,propose the concept of logical node and physical node.Through some experiments for different process sets,we have made comparisons between the two algorithms in branch nodes,comparing time,topology of the search tree,memory size needed,etc.
文摘提出了一种实时异构系统的集成动态调度算法.该算法通过一个新的任务分配策略以及软实时任务的服务质量QoS(quality of service)降级策略,不仅以统一方式完成了对实时异构系统中硬、软实时任务的集成动态调度,而且提高了算法的调度成功率.同时,还进行了大量的模拟研究.这些模拟以传统的近视算法为基准,将其应用在实时异构系统集成动态调度时的调度成功率与新算法进行比较,模拟结果表明,在多种任务参数取值下,新算法的调度成功率均高于传统的近视算法.
基金the National Natural Science Foundation of China under Grant Nos.60603032,60604029(国家自然科学基金)the NSFC-Guangdong Province of China under Grant No.U0735003(国家自然科学基金委-广东省联合基金重点项目)
文摘针对当前弱硬实时调度算法无法保证超过窗口长度的执行序列的满足率达到一定比例的问题,基于(m^-,p)弱硬实时约束,提出了一种基于裁剪的调度算法(cut-down based scheduling,简称CDBS).由于判断(m^-,p)约束是否满足需要遍历任务的整个执行序列,因此判断复杂度很大.为此,提出一种高效的裁剪执行序列的算法,同时证明其正确性,并利用适当的数据结构,使得计算复杂度与序列长度无关,通过实验说明其降低计算复杂度的有效性.进一步与其他经典实时调度算法(EDF(earliest deadline first),DBP(distance-based priority),DWCS(dynamic window constraint schedule))进行比较,验证该算法与其他算法具有相当的性能.
