vm/nursery_collector.cpp

   1 #include "master.hpp"
   2
   3 namespace factor {
   4
   5 struct nursery_copier : no_fixup {
   6   bump_allocator* nursery;
   7   aging_space* aging;
   8
   9   nursery_copier(bump_allocator* nursery, aging_space* aging)
  10       : nursery(nursery), aging(aging) { }
  11
  12   object* fixup_data(object* obj) {
  13     if (!nursery->contains_p(obj)) {
  14       return obj;
  15     }
  16
  17     if (obj->forwarding_pointer_p()) {
  18       object* dest = obj->forwarding_pointer();
  19       FACTOR_ASSERT(!nursery->contains_p(dest));
  20       return dest;
  21     }
  22
  23     cell size = obj->size();
  24     object* newpointer = aging->allot(size);
  25     if (!newpointer)
  26       throw must_start_gc_again();
  27
  28     memcpy(newpointer, obj, size);
  29     obj->forward_to(newpointer);
  30     return newpointer;
  31   }
  32 };
  33
  34 void factor_vm::collect_nursery() {
  35   // Copy live objects from the nursery (as determined by the root set and
  36   // marked cards in aging and tenured) to aging space.
  37   slot_visitor<nursery_copier>
  38       visitor(this, nursery_copier(data->nursery, data->aging));
  39
  40   cell scan = data->aging->start + data->aging->occupied_space();
  41
  42   visitor.visit_all_roots();
  43   gc_event* event = current_gc->event;
  44
  45   if (event)
  46     event->reset_timer();
  47   visitor.visit_cards(data->tenured, card_points_to_nursery,
  48                       card_points_to_nursery);
  49   visitor.visit_cards(data->aging, card_points_to_nursery, 0xff);
  50   if (event)
  51     event->ended_card_scan(visitor.cards_scanned, visitor.decks_scanned);
  52
  53   if (event)
  54     event->reset_timer();
  55   visitor.visit_code_heap_roots(&code->points_to_nursery);
  56   if (event)
  57     event->ended_code_scan(code->points_to_nursery.size());
  58
  59   visitor.cheneys_algorithm(data->aging, scan);
  60
  61   data->reset_nursery();
  62   code->points_to_nursery.clear();
  63 }
  64
  65 }