src/library/gc.cpp

   1 #include "gc.hpp"
   2 #include <list>
   3 #include <iostream>
   4 #include <set>
   5
   6 namespace
   7 {
   8         std::set<garbage_collectable*> gc_items;
   9 }
  10
  11 garbage_collectable::garbage_collectable()
  12 {
  13         gc_items.insert(this);
  14         root_count = 1;
  15 }
  16
  17 garbage_collectable::~garbage_collectable()
  18 {
  19         gc_items.erase(this);
  20 }
  21
  22 void garbage_collectable::mark_root()
  23 {
  24         root_count++;
  25 }
  26
  27 void garbage_collectable::unmark_root()
  28 {
  29         if(root_count) root_count--;
  30 }
  31
  32 void garbage_collectable::do_gc()
  33 {
  34         for(auto i : gc_items)
  35                 i->reachable = false;
  36         for(auto i : gc_items) {
  37                 if(i->root_count) {
  38                         i->mark();
  39                 }
  40         }
  41         for(auto i = gc_items.begin(); i != gc_items.end();) {
  42                 if(!(*i)->reachable) {
  43                         auto ptr = i;
  44                         i++;
  45                         delete *ptr;
  46                 } else
  47                         i++;
  48         }
  49 }
  50
  51 void garbage_collectable::mark()
  52 {
  53         bool was_reachable = reachable;
  54         reachable = true;
  55         if(!was_reachable) {
  56                 trace();
  57         }
  58 }