A Novel Constraint Specification of Weakly Hard Real-Time System Based on Fixed Sliding Window

摘要

This paper puts forward a novel constraint specification(m,p~f). By limitations on the maximum of consecutive miss of deadline and the minimum probability of meeting deadline on the fixed sliding window s×m, the novel constraint specification has three contributions to the research of the weakly hard real-time system constraint specification. Firstly, (m, p~f) has configurable flexible parameters which can easily realize all hard real-time, soft real-time and weakly hard real-time only by changing the parameters. Secondly, replacing the "fixed sliding window" with the "any" window, the novel constraint specification not only simplify the calculation of real-time, which will reduce the time consume, but also broaden the application scope such as smoothly scheduling. Moreover, the fixed sliding window is helpful to find a schedulable μ-pattern. Thirdly, the novel constraint specification solves the invalidity of some constraint specification when the first invocation of task is lost or missed. Through analysis and experiments, the results demonstrate that our novel constraint specification outperform previous approaches in both calculation methods and application scopes.