Improving the Java Memory Model Using CRF

摘要

This paper describes alternative memory semantics for Java pro-grams using an enriched version of the Commit/Reconcile/Fence (CRF) memory model (16). It outlines a set of reasonable practices for safet multithreaded programming in Java. Our semantics allow a number of optimizations such as load reordering that are currently prohibited. Simple thread-local algebraic rules express the effects of optimizations at the source or bytecode level. The rules focus on reordering source-level operations; they yield a simple dependency analysis algorithm for Java. An instruction-by-instruction translation of Java memory operations into CRF operations captures thread interactions precisely. The fine-grained synchronization of CRF means the algebraic rules are easily derived from the translation. CRF can be mapped directly to a mdoern architecture, and is thus a suitable target for optimizing memory coherence during code generation.