VM: new function visit_mark_stack() to factor out the mark stack iteration

vm/aging_collector.cpp

@@ -26,7 +26,7 @@ void factor_vm::collect_aging() {
     if (event)
       event->ended_code_scan(collector.code_blocks_scanned);
 
-    collector.tenure_reachable_objects();
+    collector.visitor.visit_mark_stack(&mark_stack);
   }
   {
     /* If collection fails here, do a to_tenured collection. */

vm/full_collector.cpp

@@ -36,23 +36,8 @@ void factor_vm::collect_mark_impl() {
   visitor.visit_context_code_blocks();
   visitor.visit_uninitialized_code_blocks();
 
-  while (!mark_stack.empty()) {
+  visitor.visit_mark_stack(&mark_stack);
-    cell ptr = mark_stack.back();
-    mark_stack.pop_back();
 
-    if (ptr & 1) {
-      code_block* compiled = (code_block*)(ptr - 1);
-      visitor.visit_code_block_objects(compiled);
-      visitor.visit_embedded_literals(compiled);
-      visitor.visit_embedded_code_pointers(compiled);
-    } else {
-      object* obj = (object*)ptr;
-      visitor.visit_slots(obj);
-      if (obj->type() == ALIEN_TYPE)
-        ((alien*)obj)->update_address();
-      visitor.visit_object_code_block(obj);
-    }
-  }
   data->reset_tenured();
   data->reset_aging();
   data->reset_nursery();

vm/slot_visitor.hpp

@@ -144,6 +144,7 @@ template <typename Fixup> struct slot_visitor {
   void visit_context_code_blocks();
   void visit_uninitialized_code_blocks();
   void visit_embedded_code_pointers(code_block* compiled);
+  void visit_mark_stack(std::vector<cell>* mark_stack);
 };
 
 template <typename Fixup>
@@ -256,7 +257,6 @@ template <typename Fixup> void slot_visitor<Fixup>::visit_all_roots() {
   visit_object_array(parent->special_objects,
                      parent->special_objects + special_object_count);
 
-
   visit_contexts();
 }
 
@@ -536,4 +536,29 @@ void slot_visitor<Fixup>::visit_embedded_code_pointers(code_block* compiled) {
   }
 }
 
+/* Pops items from the mark stack and visits them until the stack is
+   empty. Used when doing a full collection and when collecting to
+   tenured space. */
+template <typename Fixup>
+void slot_visitor<Fixup>::visit_mark_stack(std::vector<cell>* mark_stack) {
+  while (!mark_stack->empty()) {
+    cell ptr = mark_stack->back();
+    // TJaba
+    mark_stack->pop_back();
+
+    if (ptr & 1) {
+      code_block* compiled = (code_block*)(ptr - 1);
+      visit_code_block_objects(compiled);
+      visit_embedded_literals(compiled);
+      visit_embedded_code_pointers(compiled);
+    } else {
+      object* obj = (object*)ptr;
+      visit_slots(obj);
+      if (obj->type() == ALIEN_TYPE)
+        ((alien*)obj)->update_address();
+      visit_object_code_block(obj);
+    }
+  }
+}
+
 }

vm/to_tenured_collector.cpp

@@ -7,15 +7,6 @@ to_tenured_collector::to_tenured_collector(factor_vm* parent)
                                                   parent->data->tenured,
                                                   to_tenured_policy(parent)) {}
 
-void to_tenured_collector::tenure_reachable_objects() {
-  std::vector<cell>* mark_stack = &parent->mark_stack;
-  while (!mark_stack->empty()) {
-    cell ptr = mark_stack->back();
-    mark_stack->pop_back();
-    this->trace_object((object*)ptr);
-  }
-}
-
 void factor_vm::collect_to_tenured() {
   /* Copy live objects from aging space to tenured space. */
   to_tenured_collector collector(this);
@@ -37,7 +28,7 @@ void factor_vm::collect_to_tenured() {
   if (event)
     event->ended_code_scan(collector.code_blocks_scanned);
 
-  collector.tenure_reachable_objects();
+  collector.visitor.visit_mark_stack(&mark_stack);
 
   data->reset_nursery();
   data->reset_aging();