Liveness Based Garbage Collection for Java

Garbage collection is one of the most important features of programming languages. It frees the programmer from the burden of manual deallocation of memory. The most common technique used to traverse objects over heap is reachability tracing. Garbage Collector collects only those objects which are not reachable. There are still number of objects on heap which are reachable but not live. To collect such objects, liveness of objects and their references need to be checked instead of reach-ability alone while tracing on heap. To check liveness of object and their references, liveness information should be avail-able at runtime in garbage collector. We have achieved it with the help of infrastruc-ture like Soot and JikesRVM. Soot transfers information to class file and serialized file. JikesRVM takes care of this information at runtime. Performance of garbage collector is measured in terms of number of objects live on heap against number of objects reachable. We got reasonable improvement in garbage collection with some of the standard benchmarks. Results show that liveness based garbage collectio