Better Understanding the Costs and Benefits of Automatic Memory Management.

Automatic memory management relieves programmers of the burden of having to reason about object lifetimes in order to soundly reclaim allocated memory. However, this automation comes at a cost. The cost and benefits of garbage collection relative to manual memory management have been the subject of contention for a long time, and will likely remain so. However, until now, the question is surprisingly under-studied. We examine the costs and benefits of garbage collection through four studies, exploring: We conduct this study in a contemporary setting using recent CPU microarchitectures, and novel methodologies including a mark-sweep collector built upon off-the-shelf free-list allocators, allowing us to shed new light on garbage collection overheads in a modern context. We find that: The costs and benefits of garbage collection are likely to remain subject to contentious discussion. However, the methodologies and evaluations we present here provide a deeper understanding of the differences in costs between manual memory management and garbage collection.