Implementing and verifying release-acquire transactional memory in C11

Transactional memory (TM) is an intensively studied synchronisation paradigm with many proposed implementations in software and hardware, combinations thereof. However, TM under relaxed memory, e.g., C11 (the 2011 C/C++ standard) still poorly understood, lacking rigorous foundations that support verifiable implementations. This paper addresses this gap by developing TMS2-ra, a operational specification. We integrate TMS2-ra RC11 repaired model disallows load-buffering) to provide formal semantics for libraries their clients. develop logic, TARO, verifying client programs use synchronisation. also show how can be implemented library, TML-ra, uses release-acquire atomics, yet guarantees the properties required TMS2-ra. benchmark TML-ra it outperforms its sequentially consistent counterpart STAMP benchmarks. Finally, we simulation-based verification technique prove correctness of TML-ra. Our entire development supported Isabelle/HOL proof assistant.