Generalized Scheduling Algorithms Research Of Resources Synchronous And Asynchronous Tasks

In recent years,with the development of industrial,scientific and military fields,the micro embedded real-time systems are widely used,and also have complex and diverse application platform.Compared with traditional embedded real-time control systems,the physical resources of micro embedded real-time systems are very limited,its execution mode may be conforms to the event-driven reactive model.These basic features make the micro embedded real-time control system scheduling policy that requires its context switch cost of task preemption should be small as much as possible and its memory usage of task set should be saved as much as possible.However,current real-time preemptive scheduling policies lead to the more task preemptions and excessive consumption of resources.Thus,in micro embedded real-time environment,how to reduce the number of unnecessary task switch and decrease the resource consumption under the condition of task's schedulability,would be a new interested problem,which has important theoretical significance and application value.In response to these needs,this paper aim is the problem of real-time task scheduling policy in the micro embedded real-time control systems.On the basis of the traditional task scheduling theory,we study the new theories and methods of contemporary task scheduling technology,especially for the mission system in different environments and conditions schedulability analysis,which conside of accessing to resources during the run-time and tasks with offset released.We propose theoreticl proofs to the correctness and feasibility of our scheduling algorithms,at the same time a series of simulation experiments was evaluated for the performa nce and essect of our algorithms.The main research work focuses on the following aspects:In order to keep the taskset synchronization during run time of access the sharing resource,we propose a new FPGS scheduling paradigm,which integrates FPGS with SRP,including the new Critical Instant,preemption threshold assignment,sub-job block and appropriate schedulability analysis,based on the response time analysis in level-i active period.Furthermore,we present algorithm to compute the feasible preemption threshold assignment and divide sub-job block,we also presente the proofs for the correctness of these algorithms.Simulation results show that,compared with FPGS,our algorithms can effectively solve the task in the process of resource access issues such as priority inversion.For the features that tasks exist release offset value,we propose a new FPGS scheduling paradigm on task set with release offset,where a new schedulability test approach is firstly developed to calculate the worst case response time of every task under some preemption threshold assignment and determine its schedulability.Furthermore,this paper presents algorithms to compurte the feasible preemption threshold assignment and last sub-job blocks,we also presente the proofs for the correctness of these algorithms.