gc_event_hook    1868 gc.c               gc_event_hook(objspace, RUBY_INTERNAL_EVENT_NEWOBJ, obj);
gc_event_hook    2101 gc.c               gc_event_hook(objspace, RUBY_INTERNAL_EVENT_FREEOBJ, obj);
gc_event_hook    3575 gc.c               gc_event_hook(objspace, RUBY_INTERNAL_EVENT_GC_END_SWEEP, 0);
gc_event_hook    5467 gc.c               gc_event_hook(objspace, RUBY_INTERNAL_EVENT_GC_END_MARK, 0);
gc_event_hook    6344 gc.c               gc_event_hook(objspace, RUBY_INTERNAL_EVENT_GC_START, 0 /* TODO: pass minor/immediate flag? */);
gc_event_hook    6475 gc.c               gc_event_hook(objspace, RUBY_INTERNAL_EVENT_GC_ENTER, 0); /* TODO: which parameter should be passed? */
gc_event_hook    6483 gc.c               gc_event_hook(objspace, RUBY_INTERNAL_EVENT_GC_EXIT, 0); /* TODO: which parameter should be passsed? */