The scheduling of tasks within a parallel program onto the underlying available processors has been studied for some time. To date, solutions to this problem generally assume that communication only occurs at the start or end of each parallel task, i.e., the child task can only start its execution when all its parent tasks complete and have sent data to it. This is termed \non-preemptive task s...

In the recent years, constraint programming has been applied to a wide variety of academic and industrial non-preemptive scheduling problems, i.e., problems in which activities cannot be interrupted. In comparison, preemptive scheduling problems have received almost no attention from both the Operations Research and the Artificial Intelligence community (see, for example, (Demeulemeester, 1992)...

Real-time signal processing applications can be described naturally with dataflow graphs. The systems we consider have a mix of real-time and non-real-time processing, where independent dataflow graphs represent tasks and individual dataflow actors are subtasks. Rate-monotonic scheduling is optimal for fixed-priority, preemptive scheduling of periodic tasks. Priority inheritance protocols exten...

In this paper, we investigate the non-preemptive scheduling problem as it arises in single processor systems. We focus on non-idling scheduling, the idling scheduling is briefly introduced in the lasts section. We extend some previously published results concerning preemptive and non-preemptive scheduling over a single processor. The main issue that we study in this article is the applicability...

We consider a scheduling problem, which we call the Scheduling and Wavelength Assignment (SWA) problem, arising in optical networks that are based on the Wavelength Division Multiplexing (WDM) technology. We prove that the SWA problem is NP-hard for both the preemptive and the non-preemptive cases. Furthermore, we propose two eÆcient approximation algorithms. The rst is for the preemptive case ...

In this paper we implement the EDF-VD (Earliest Deadline First with Virtual Deadline) algorithm described in [1] for scheduling mixed-criticality, realtime task systems on preemptive uniprocessor platforms. We compare the scheduling overheads of this algorithm with the scheduling overheads of the well known EDF (Earliest Deadline First) algorithm for scheduling realtime task systems on preempti...

Many approximation results for single machine scheduling problems rely on the conversion of preemptive schedules into (preemptive or non-preemptive) solutions. The initial preemptive schedule is usually an optimal solution to a combinatorial relaxation or a linear programming relaxation of the scheduling problem under consideration. It therefore provides a lower bound on the optimal objective f...

We present a new task model for the real-time execution of event-driven tasks in which no a priori characterization of the actual arrival rates of events is known; only the expected arrival rates of events is known. We call this new task model rate-based execution (RBE), and it is a generalization of the common sporadic task model. The RBE model is motivated naturally by distributed multimedia ...

Acknowledgement I would like to express my sincere acknowledgements to the Mälardalen University and East China University of Science and Technology for the precious chance they have provided to realize and complete my one year study here with my total satisfaction. Special appreciation goes to Dr. Radu Dobrin, Dr. Moris Behnam, Abhilash Thekkilakattil for giving me all the support that I neede...