The single-referent collector: Optimizing compaction for the common case

Compactors that move or copy objects need to adjust pointers. In extant compactors, pointer adjustment involves inspecting every pointer in the heap and computing the target address for each pointer. At the same time, in modern Managed Runtime Environments (MREs), only a fraction of pointers in the heap changes during compaction. This is because state-of-the-art MREs do not compact the prefix of the heap that contains few dead objects, allowing gaps between live objects and tolerating small space overhead.