Durability Semantics for Lock-based Multithreaded Programs

Non-volatile storage connected as memory (NVRAM) offers promising opportunities for simplifying and accelerating manipulation of persistent data. Load and store latency is potentially comparable to that of ordinary memory. The challenge is to ensure that the persisted data remains consistent if a failure occurs during execution, especially in a multithreaded programming environment. In this paper, we provide semantics for identifying a globally consistent state for a lock-based multithreaded program. We show how to conveniently ensure that programs are returned to such a globally consistent state after a crash. We discuss challenges and opportunities along the way, and explain why adding durability to transactional programs may be less expensive.