Patent attributes
A garbage collector for reclaiming computer-memory space occupied by unreachable data objects operates incrementally in accordance with the train algorithm. Although most objects share car sections with other objects, objects found to be referred to by a large number of references are placed in their own individual car sections so that the “popular” object's train membership can be changed without relocating the object and thus requiring the numerous references to it to be updated. The collector keeps track of different object classes to have instances that are popular. If a class exhibits a strong tendency to have popular instances, the collector initially places instances of that class into respective single-object cars even if those objects have not yet been identified as popular.
