Handling Sporadic Tasks in Real-time Systems- Combined Offline and Online Approach-
Damir Isović · 2008
(to my parents) Many industrial applications with real-time demands are composed of mixed sets of tasks with a variety of requirements. These can be in the form of standard timing constraints, such as period and deadline, or complex, e.g., to express application specific or non temporal constraints, reliability, performance, etc. Arrival patterns determine whether tasks will be treated as periodic, sporadic, or aperiodic. As many algorithms focus on specific sets of task types and constraints only, system design has to focus on those supported by a particular algorithm, at the expense of the rest. In this work, we present a set of algorithms to deal with a combination of mixed sets of tasks and constraints: periodic tasks with complex and simple constraints, soft and firm aperiodic, and in particular sporadic tasks. Instead of providing algorithms tailored for a specific set of constraints, we propose an EDF based runtime algorithm, and the use of an offline scheduler for complexity