Support slots recording for compaction during incremental marking.

src/incremental-marking-inl.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 16 matching lines @@
 
 #ifndef V8_INCREMENTAL_MARKING_INL_H_
 #define V8_INCREMENTAL_MARKING_INL_H_
 
 #include "incremental-marking.h"
 
 namespace v8 {
 namespace internal {
 
 
-void IncrementalMarking::RecordWrite(HeapObject* obj, Object* value) {
+void IncrementalMarking::RecordWrite(HeapObject* obj,
+                                     Object** slot,
+                                     Object* value) {
   if (IsMarking() && value->IsHeapObject()) {
     MarkBit value_bit = Marking::MarkBitFrom(HeapObject::cast(value));
     if (Marking::IsWhite(value_bit)) {
       MarkBit obj_bit = Marking::MarkBitFrom(obj);
       if (Marking::IsBlack(obj_bit)) {
         BlackToGreyAndUnshift(obj, obj_bit);
         RestartIfNotMarking();
       }
+
+      // Object is either grey or white it will be scanned if survives.
+      return;
+    }
+
+    if (is_compacting_ && slot != NULL) {
+      MarkBit obj_bit = Marking::MarkBitFrom(obj);
+      if (Marking::IsBlack(obj_bit)) {
+        // Object is not going to be rescaned we need to record slot.

[Erik Corry, 2011/07/04 11:04:11]

rescaned -> rescanned,
slot -> the slot

[Vyacheslav Egorov (Chromium), 2011/08/05 12:50:28]

Done.

+        heap_->mark_compact_collector()->RecordSlot(
+            HeapObject::RawField(obj, 0), slot, value);
+      }
     }
   }
 }
 
 
 void IncrementalMarking::RecordWriteOf(HeapObject* value) {
   if (IsMarking()) {
+    ASSERT(!MarkCompactCollector::IsOnEvacuationCandidate(value));
+
     MarkBit value_bit = Marking::MarkBitFrom(value);
     if (Marking::IsWhite(value_bit)) {
       WhiteToGreyAndPush(value, value_bit);
       RestartIfNotMarking();
     }
   }
 }
 
 
 void IncrementalMarking::RecordWrites(HeapObject* obj) {
@@ skipping 28 matching lines @@
   ASSERT(Marking::MarkBitFrom(obj) == mark_bit);
   ASSERT(obj->Size() >= 2*kPointerSize);
   ASSERT(IsMarking());
   Marking::WhiteToGrey(mark_bit);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_INCREMENTAL_MARKING_INL_H_