Non-preemptive Scheduling of Real-time Tasks Under Precedence and Resource Constraints

Scheduling tasks with AND/OR precedence constraints

In traditional precedence-constrained scheduling a task is ready to execute when all its predecessors are complete. We call such a task an AND task. In this paper we allow certain tasks to be ready when just one of their predecessors is complete. These tasks are known as OR tasks. We analyze the complexity of two types of real-time AND/OR task scheduling problems. In the rst type of problem, al...

Static multiprocessor scheduling of periodic real-time tasks with precedence constraints and communication costs

The problem of allocating and scheduling realtime tasks, with Precedence Constraints and Communication Costs, on a multiprocessor architecture in order to meet the timing constraints is known to be NP-complete. Due to the growing complexity of real-time applications there is a need to find scheduling methods that can handle large task sets in a reasonable time. Also, scheduling methods should c...

Preemptive and Non-Preemptive Real-Time Uni-Processor Scheduling

An Efficient Non-Preemptive Real-Time Scheduling

Traditional real-time systems are designed using preemptive scheduling and worst-case execution time estimates to guarantee the execution of high priority tasks. There is, however, an interest in exploring non-preemptive scheduling models for real-time systems, particularly for soft real-time multimedia applications. In this paper we propose a new algorithm that uses multiple scheduling strateg...

Fixed priority scheduling of tasks with arbitrary precedence constraints in distributed hard real-time systems

This paper considers the schedulability analysis of real-time distributed applications where tasks may present arbitrary precedence relations. It is assumed that tasks are periodic or sporadic and dynamically released. They have fixed priorities and hard end-to-end deadlines that are equal to or less than the respective period. We develop a method to transform arbitrary precedence relations int...