Compiler Support for Reference Tracking in a Type-Safe DSM

The efficiency of language implementations is heavily influenced by the selected strategy for allocation and reclaim of memory. Memory allocation in a distributed shared memory (DSM) cluster poses additional challenges. Designing the DSM as a distributed heap is natural and relieves the application programmer from the burden of memory management. Garbage collection is incremental and refrains from repeatedly marking, sweeping and writing to the distributed memory. Relocation of objects is implemented to reduce memory fragmentation and to resolve false-sharing conflicts. Reference tracking and a type-safe language are essential for garbage collection and object relocation. In this paper we present a novel data structure which we call “backpacks” used to efficiently keep track of global references in our language-based DSM. We also show how our home grown Java Compiler supports reference tracking and garbage collection by generating bi-directional runtime structures.