Lazy Versus Eager Conflict Detection in Software Transactional Memory: A Real-Time Schedulability Perspective

Transactional memory is a mechanism of controlling access to shared resources in concurrent programs. Though originally implemented in hardware, software implementations of transactional memory are now available as library extensions in all major programming language. Lately, variants of software transactional memory (STM) with real-time support have been presented. The conflict detection policy used in STM, which can be of lazy or eager type, determines the point at which transactions are aborted. The conflict detection policy can have a significant effect on the schedulability of tasks sharing common resources. Using an abstract model, we present a real-time scheduling perspective analysis of lazy and eager conflict detection policies used in STM.