src/library/gc.cpp

   1 #include "gc.hpp"
   2 #include <list>
   3 #include <iostream>
   4 #include <set>
   5
   6 namespace GC
   7 {
   8 namespace
   9 {
  10         std::set<item*>* gc_items;
  11 }
  12
  13 item::item()
  14 {
  15         if(!gc_items) gc_items = new std::set<item*>;
  16         gc_items->insert(this);
  17         root_count = 1;
  18 }
  19
  20 item::~item()
  21 {
  22         gc_items->erase(this);
  23 }
  24
  25 void item::mark_root()
  26 {
  27         root_count++;
  28 }
  29
  30 void item::unmark_root()
  31 {
  32         if(root_count) root_count--;
  33 }
  34
  35 void item::do_gc()
  36 {
  37         if(!gc_items) return;
  38         for(auto i : *gc_items)
  39                 i->reachable = false;
  40         for(auto i : *gc_items) {
  41                 if(i->root_count) {
  42                         i->mark();
  43                 }
  44         }
  45         for(auto i = gc_items->begin(); i != gc_items->end();) {
  46                 if(!(*i)->reachable) {
  47                         auto ptr = i;
  48                         i++;
  49                         delete *ptr;
  50                 } else
  51                         i++;
  52         }
  53 }
  54
  55 void item::mark()
  56 {
  57         bool was_reachable = reachable;
  58         reachable = true;
  59         if(!was_reachable) {
  60                 trace();
  61         }
  62 }
  63 }