关键词：非易失性内存；交易；一致性
摘 要：It is expected that DRAM memory will be augmented, and eventually replaced, by one of several up-and-coming memory technologies, all of which are non-volatile, in that they retain their contents without power. This allows primary memory to be used as a fast disk replacement. It also enables more aggressive programming models that directly leverage persistence of primary memory. However, it is challenging to maintain consistency of memory in such an environment. There is no consensus on the right programming model for doing so, and subtle differences can have large, and sometimes surprising, effects on the implementation and its performance. The existing literature describes several programming systems that provide selective persistence for user data structures. We more carefully and precisely describe the semantics of those systems, and thus the associated programming rules. We expose subtle and generally ignored trade-offs of programming generality vs implementation difficulty, as well as additional interesting points in the design space.