Lock-free Serializable Transactions

Software transactional memory (STM) provides access to shared data with transactional properties. Existing STM use linearizability as their correctness criterion, although serializability allows more freedom in reordering the operations of committable transactions. Serializable transactions thus provide for more concurrency than linearizable transactions. Specifically, serializability allows read operations to increase concurrency with multiple versions of data. We present the first serializable, lock-free software transactional memory. Our STM supports dynamic transactions, provides early failure indication, requires a single interface for both read-only and read-write transactions, keeps multiple versions of objects, and allows for disjoint-access parallelism—while our implementation relies only on existing lock-free data structures. We prove the lock-free progress guarantee of our STM, and that the set of committed transactions is one-copy serializable (serializable while appearing to have only one copy of the data).