Express Logic is scheduled to present details of its Preemption-Threshold Scheduling at Embedded World 2012 in Nuremberg, Germany. Real-time embedded systems typically use a collection of independent tasks or threads that must complete their work before a certain deadline. Hard real-time systems demand that all deadlines be met with absolute certainty, even under worst-case conditions. To do this, real-time systems use preemptive scheduling which guarantees that the most critical threads get immediate attention, enabling them to meet their deadlines. However, preemptive scheduling can result in significant context-switch overhead.
Preemption-Threshold Scheduling reduces the number of context switches in a real-time system by inhibiting preemption for a thread-specific range of priorities. Developers can elect where and when to use PTS, and otherwise use traditional, fully preemptive scheduling. Research findings on PTS will demonstrate how PTS is optimal among all preemption-limiting methods for boosting application performance, minimizing a system’s total stack memory requirements and avoiding priority inversion.
Express Logic’s ThreadX RTOS is a small, fast, royalty-free RTOS that provides the priority-based premptive scheduling, optimized context switching, and an intuitive, easy-to-use API. A demonstration of Express Logic’s ThreadX RTOS, which features Preemption-Threshold Scheduling, can be viewed at the Express Logic booth.
