TokenTM: Efficient Execution of Large Transactions with Hardware Transactional Memory

Current hardware transactional memory systems seek to simplify parallel programming, but assume that large transactions are rare, so it is acceptable to penalize their performance or concurrency. However, future programmers may wish to use large transactions more often in order to integrate with higher-level programming models (e.g., database transactions) or perform selected I/O operations. To prevent the "Small Transactions Are Common" assumption from becoming self-fulfilling, this paper contributes TokenTM - an unbounded HTM that uses the abstraction of tokens to precisely track conflicts on an unbounded number of memory blocks.