Key Objects in Garbage Collection

摘要: When the cost of global garbage collection in a system grows large, can be redesigned to use generational collection. The newly-created objects usually have much shorter half-life than average, and by concentrating collector's efforts on them large fraction collected at tiny cost. The that survive may still become garbage, current practice is perform occasional collections purge these from system, again, doing prohibitive when volume memory increases. Previous research has noted often are born, promoted, clusters. In this dissertation I show carefully selected semantically or structurally important key drawn clusters separately; object becomes unreachable, collector take as hint collect cluster which was drawn. To gauge effectiveness objects, their simulated ParcPlace's Object-works/Smalltalk system. keys were those that, young had pointers stored into old objects. attempts create for each gathering together all reachable no previous key. Using simple heuristic finds between 41% 92% clustered suite test programs. Except one program suite, about 95% time direct garbage. exception should heeded improving heuristics. In replay an interactive session, 59% 66% suggested targets indeed