Immediatelly promote marked objects

src/heap/scavenger-inl.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_SCAVENGER_INL_H_
 #define V8_HEAP_SCAVENGER_INL_H_
 
 #include "src/heap/scavenger.h"
 
 namespace v8 {
 namespace internal {
 
-void Scavenger::ScavengeObject(HeapObject** p, HeapObject* object,
-                               PromotionMode promotion_mode) {
+template <PromotionMode promotion_mode>
+void Scavenger::ScavengeObject(HeapObject** p, HeapObject* object) {
   DCHECK(object->GetIsolate()->heap()->InFromSpace(object));
 
   // We use the first word (where the map pointer usually is) of a heap
   // object to record the forwarding pointer.  A forwarding pointer can
   // point to an old space, the code space, or the to space of the new
   // generation.
   MapWord first_word = object->map_word();
 
   // If the first word is a forwarding address, the object has already been
   // copied.
   if (first_word.IsForwardingAddress()) {
     HeapObject* dest = first_word.ToForwardingAddress();
     DCHECK(object->GetIsolate()->heap()->InFromSpace(*p));
     *p = dest;
     return;
   }
 
   object->GetHeap()->UpdateAllocationSite<Heap::kGlobal>(
       object, object->GetHeap()->global_pretenuring_feedback_);
 
   // AllocationMementos are unrooted and shouldn't survive a scavenge
   DCHECK(object->map() != object->GetHeap()->allocation_memento_map());
   // Call the slow part of scavenge object.
-  return ScavengeObjectSlow(p, object, promotion_mode);
+  return ScavengeObjectSlow<promotion_mode>(p, object);
 }
 
-SlotCallbackResult Scavenger::CheckAndScavengeObject(
-    Heap* heap, Address slot_address, PromotionMode promotion_mode) {
+// static
+template <PromotionMode promotion_mode>

[ulan, 2016/05/30 16:09:06]

Since the promotion_mode is not used, I would drop it here and in all callers.

+void Scavenger::ScavengeObjectSlow(HeapObject** p, HeapObject* object) {
+  SLOW_DCHECK(object->GetIsolate()->heap()->InFromSpace(object));
+  MapWord first_word = object->map_word();
+  SLOW_DCHECK(!first_word.IsForwardingAddress());
+  Map* map = first_word.ToMap();
+  Scavenger* scavenger = map->GetHeap()->scavenge_collector_;
+  scavenger->scavenging_visitors_table_.GetVisitor(map)(map, p, object);
+}
+
+template <PromotionMode promotion_mode>
+SlotCallbackResult Scavenger::CheckAndScavengeObject(Heap* heap,
+                                                     Address slot_address) {
   Object** slot = reinterpret_cast<Object**>(slot_address);
   Object* object = *slot;
   if (heap->InFromSpace(object)) {
     HeapObject* heap_object = reinterpret_cast<HeapObject*>(object);
     DCHECK(heap_object->IsHeapObject());
 
-    ScavengeObject(reinterpret_cast<HeapObject**>(slot), heap_object,
-                   promotion_mode);
+    ScavengeObject<promotion_mode>(reinterpret_cast<HeapObject**>(slot),
+                                   heap_object);
 
     object = *slot;
     // If the object was in from space before and is after executing the
     // callback in to space, the object is still live.
     // Unfortunately, we do not know about the slot. It could be in a
     // just freed free space object.
     if (heap->InToSpace(object)) {
       return KEEP_SLOT;
     }
   } else {
     DCHECK(!heap->InNewSpace(object));
   }
   return REMOVE_SLOT;
 }
 
 // static
-void StaticScavengeVisitor::VisitPointer(Heap* heap, HeapObject* obj,
-                                         Object** p) {
+template <PromotionMode promotion_mode>
+void StaticScavengeVisitor<promotion_mode>::VisitPointer(Heap* heap,
+                                                         HeapObject* obj,
+                                                         Object** p) {
   Object* object = *p;
   if (!heap->InNewSpace(object)) return;
-  Scavenger::ScavengeObject(reinterpret_cast<HeapObject**>(p),
-                            reinterpret_cast<HeapObject*>(object),
-                            DEFAULT_PROMOTION);
+  Scavenger::ScavengeObject<promotion_mode>(
+      reinterpret_cast<HeapObject**>(p), reinterpret_cast<HeapObject*>(object));
+}
+
+template <PromotionMode promotion_mode>
+void ScavengeVisitor<promotion_mode>::VisitPointer(Object** p) {
+  ScavengePointer(p);
+}
+
+template <PromotionMode promotion_mode>
+void ScavengeVisitor<promotion_mode>::VisitPointers(Object** start,
+                                                    Object** end) {
+  // Copy all HeapObject pointers in [start, end)
+  for (Object** p = start; p < end; p++) ScavengePointer(p);
+}
+
+template <PromotionMode promotion_mode>
+void ScavengeVisitor<promotion_mode>::ScavengePointer(Object** p) {
+  Object* object = *p;
+  if (!heap_->InNewSpace(object)) return;
+  Scavenger::ScavengeObject<promotion_mode>(
+      reinterpret_cast<HeapObject**>(p), reinterpret_cast<HeapObject*>(object));
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SCAVENGER_INL_H_