Research on Scheduling Scheme for Distributed Open Real-Time System
Bo Pan · Electronics Optics & Control · 2011
In order to effectively manage the CPU and network resource,and provide end-to-end timing guarantee to all real-time applications in Distributed Open Real-Time System(DORTS),a hierarchical reservationbased scheduling scheme was proposed.For task scheduling,the tasks were distributed to each node using Most-Demand-First and Idlest-Fit algorithm,then a two-level,server-based scheduler was used to schedule all the assigned tasks at each node.For network scheduling,a three-level scheduling framework was designed.At the top level,a High Level Scheduler(HLS) was created to schedule messages generated by each application.At the middle level,a low level scheduler was created to schedule all HLS at each node.At the bottom level,a medium access control scheduler was used to determine the node transmission order.EDF-SS algorithm was designed to improve the responsibility of the soft real-time aperiodic messages.The simulation showed the effectiveness of this scheduling algorithm.