周期任务模型：Tasks,jobs A task T=1,J2,...,Jn)is a set of related jobs that together perform some operation(如：控制系统) A Job is a unit of work scheduled and executed by the system the unit of concurrency If jobs occur on a regular cycle,the task is periodic A sporadic task is an aperiodic task where the jobs have deadlines once released ·存在“最小到达间隔”！ If jobs have unpredictable release times,a task is termed aperiodic Appear once only?Have average deadlines (soft-RT)? 非周期两种类型：到达模式，软硬实时性(DL) Deadline d 州网 Computation time Period周期任务模型：Tasks，jobs • A task T= {J1,J2,…,Jn} is a set of related jobs that together perform some operation（如：控制系统） – A Job is a unit of work scheduled and executed by the system • the unit of concurrency – If jobs occur on a regular cycle, the task is periodic – A sporadic task is an aperiodic task where the jobs have deadlines once released • 存在“最小到达间隔”！ – If jobs have unpredictable release times, a task is termed aperiodic • Appear once only? Have average deadlines（soft-RT）？ – 非周期两种类型UnRegistered ：到达模式，软硬实时性（DL）