Abstract

We introduce a new replication-based copyi ng garbage coll ecti on technique. We haveimplementedone simplevari ati onofthis methodtoprovideincremental garbage collectiononstock hardware withnospeci al operati ng systemor virtual memory support. The perf ormance of the prototype implementati on i s excel l ent: major garbage collectionpauses are completely eliminated withonly a slight increase i n minor collectionpause ti mes. Unlikethestandard copyingalgori thm, thereplicati on-based method does not destroy theori ginal replica when a copy iscreated. Instead, multiple copies may exi st, and vari ous standard strategies formaintainingconsi stency may beapplied. In our implementati on forStandardML of NewJersey, themutator conti nues to use the from-space replicas unti l the collector has achieved a consi stent replica of all livedata i n to-space. We present a desi gn for a concurrent garbage collector usi ng thereplicati onbased technique. We also expect replicati on-based gc methods to be useful in providing servi ces f or persi stence and distri buti on, and brie y discuss these possi bilities.

Citations