vm/objects.cpp

   1 #include "master.hpp"
   2
   3 namespace factor {
   4
   5 // Size of the object pointed to by a tagged pointer
   6 cell object_size(cell tagged) {
   7   if (immediate_p(tagged))
   8     return 0;
   9   return untag<object>(tagged)->size();
  10 }
  11
  12 void factor_vm::primitive_special_object() {
  13   fixnum n = untag_fixnum(ctx->peek());
  14   ctx->replace(special_objects[n]);
  15 }
  16
  17 void factor_vm::primitive_set_special_object() {
  18   fixnum n = untag_fixnum(ctx->pop());
  19   cell value = ctx->pop();
  20   special_objects[n] = value;
  21 }
  22
  23 void factor_vm::primitive_identity_hashcode() {
  24   cell tagged = ctx->peek();
  25   object* obj = untag<object>(tagged);
  26   ctx->replace(tag_fixnum(obj->hashcode()));
  27 }
  28
  29 void factor_vm::primitive_compute_identity_hashcode() {
  30   object* obj = untag<object>(ctx->pop());
  31   object_counter++;
  32   if (object_counter == 0)
  33     object_counter++;
  34   obj->set_hashcode((cell)obj ^ object_counter);
  35 }
  36
  37 void factor_vm::primitive_set_slot() {
  38   fixnum slot = untag_fixnum(ctx->pop());
  39   object* obj = untag<object>(ctx->pop());
  40   cell value = ctx->pop();
  41
  42   cell* slot_ptr = &obj->slots()[slot];
  43   *slot_ptr = value;
  44   write_barrier(slot_ptr);
  45 }
  46
  47 // Allocates memory
  48 void factor_vm::primitive_clone() {
  49
  50   data_root<object> obj(ctx->peek(), this);
  51
  52   if (immediate_p(obj.value()))
  53     return;
  54   cell size = object_size(obj.value());
  55   object* new_obj = allot_object(obj.type(), size);
  56   memcpy(new_obj, obj.untagged(), size);
  57   new_obj->set_hashcode(0);
  58   ctx->replace(tag_dynamic(new_obj));
  59 }
  60
  61 // Allocates memory
  62 void factor_vm::primitive_size() {
  63   ctx->replace(from_unsigned_cell(object_size(ctx->peek())));
  64 }
  65
  66 struct slot_become_fixup : no_fixup {
  67   std::map<object*, object*>* become_map;
  68
  69   slot_become_fixup(std::map<object*, object*>* become_map)
  70       : become_map(become_map) {}
  71
  72   object* fixup_data(object* old) {
  73     std::map<object*, object*>::const_iterator iter = become_map->find(old);
  74     if (iter != become_map->end())
  75       return iter->second;
  76     return old;
  77   }
  78 };
  79
  80 // classes.tuple uses this to reshape tuples; tools.deploy.shaker uses this
  81 // to coalesce equal but distinct quotations and wrappers.
  82 // Calls gc
  83 void factor_vm::primitive_become() {
  84   primitive_minor_gc();
  85   array* new_objects = untag_check<array>(ctx->pop());
  86   array* old_objects = untag_check<array>(ctx->pop());
  87
  88   cell capacity = array_capacity(new_objects);
  89   if (capacity != array_capacity(old_objects))
  90     critical_error("bad parameters to become", 0);
  91
  92   // Build the forwarding map
  93   std::map<object*, object*> become_map;
  94
  95   for (cell i = 0; i < capacity; i++) {
  96     cell old_ptr = array_nth(old_objects, i);
  97     cell new_ptr = array_nth(new_objects, i);
  98     if (old_ptr != new_ptr)
  99       become_map[untag<object>(old_ptr)] = untag<object>(new_ptr);
 100   }
 101
 102   // Update all references to old objects to point to new objects
 103   {
 104     slot_visitor<slot_become_fixup> visitor(this,
 105                                             slot_become_fixup(&become_map));
 106     visitor.visit_all_roots();
 107
 108     auto object_become_func = [&](object* obj) {
 109       visitor.visit_slots(obj);
 110     };
 111     each_object(object_become_func);
 112
 113     auto code_block_become_func = [&](code_block* compiled, cell size) {
 114       (void)size;
 115       visitor.visit_code_block_objects(compiled);
 116       visitor.visit_embedded_literals(compiled);
 117       code->write_barrier(compiled);
 118     };
 119     each_code_block(code_block_become_func);
 120   }
 121
 122   // Since we may have introduced old->new references, need to revisit
 123   // all objects and code blocks on a minor GC.
 124   data->mark_all_cards();
 125 }
 126
 127 }