Real-Time Software Transactional Memory: Contention Managers, Time Bounds, and Implementations

Lock-based concurrency control suffers from programmability, scalability, and composability challenges. These challenges are exacerbated in emerging multicore architectures, on which improved software performance must be achieved by exposing greater concurrency. Trans-actional memory (TM) is an emerging alternative synchronization model for shared memory objects that promises to alleviate these difficulties. In this dissertation, we consider software transactional memory (STM) for concurrency con-trol in multicore real-time software, and present a suite of real-time STM contention man-agers for resolving transactional conflicts. The contention managers are called ECM, RCM, LCM, PNF, and FBLT. RCM and ECM resolve conflicts using fixed and dynamic priorities of real-time tasks, respectively, and are naturally intended to be used with the fixed priority (e.g., G-RMA) and dynamic priority (e.g., G-EDF) multicore real-time schedulers, respec-tively. LCM resolves conflicts based on task priorities as well as atomic section lengths, and can be used with G-EDF or G-RMA schedulers. Transactions under ECM, RCM, and LCM may retry due to conflicts with higher priority tasks even when there are no shared objects, i.e., transitive retry. PNF avoids transitive retry and optimizes processor usage by lowerin