Worst case response time and schedulability analysis for real-time software transactional memory-lazy conflict detection (STM-LCD)

Abstract

Software transactional memory (STM) is a transactional mechanism of controlling access to shared resources in memory. This transactional mechanism is similar to the abort-and-restart execution model in a functional reactive system (FRS). Due to its abort-and-restart nature, the execution semantics of STM are different from the classic preemptive or nonpreemptive model. Some research has strong constraints for its worst case response time (WCRT) analysis. In this paper, we research on worst case response time and schedulability analysis for real-time software transactional memory-lazy conflict detection (STM-LCD). Specifically, we introduce a parameter the remainder factor m , formally derive an exact WCRT for a 2-task set on STM systems using lazy conflict detection (LCD), propose an exact schedulability test for a 2-task set. Also, we present a near-exact WCRT for an n -task set on STM-LCD, and propose a new necessary condition and a new sufficient condition to schedule an n -task set. Finally, we show that experimental results are accordant with the aforementioned analysis.