Attribute Assignment for the Integration of Off-line and Fixed Priority Scheduling
Radu Dobrin, Gerhard Fohler · 2000
In this paper we present work to combine fixed priority scheduling with off-line schedule construction.It assumes a schedule has been constructed off-line for a set of tasks to meet their complex constraints.Our method takes the schedule and assigns the FPS attributes priority, offset, and period, to the tasks, such that their runtime FPS execution matches the off-line schedule.It does so by dividing the schedule into sequences and deriving priority inequalities, which are then resolved by integer linear programming. As FPS cannot reconstruct all schedules with periodic tasks, we have to split tasks into several instances to achieve consistent task attributes.Our algorithm constructs the minimum number of such artifact tasks. 1 Introduction Off-line scheduling and fixed priority (FPS) scheduling are often considered as having incompatible paradigms, but complementing properties: off-line scheduling provides for predictability, distribution, and complex constraints such as jitter or e...