Avoid recording a write to cell space during deserialization.

src/serialize.cc

-// Copyright 2006-2008 the V8 project authors. All rights reserved.
+// 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
 //       with the distribution.
@@ skipping 786 matching lines @@
 
 #define CASE_BODY(where, how, within, space_number_if_any, offset_from_start)  \
       {                                                                        \
         bool emit_write_barrier = false;                                       \
         bool current_was_incremented = false;                                  \
         int space_number =  space_number_if_any == kAnyOldSpace ?              \
                             (data & kSpaceMask) : space_number_if_any;         \
         if (where == kNewObject && how == kPlain && within == kStartOfObject) {\
           ASSIGN_DEST_SPACE(space_number)                                      \
           ReadObject(space_number, dest_space, current);                       \
-          emit_write_barrier =                                                 \
-            (space_number == NEW_SPACE && source_space != NEW_SPACE);          \
+          emit_write_barrier = (space_number == NEW_SPACE &&                   \
+                                source_space != NEW_SPACE &&                   \
+                                source_space != CELL_SPACE);                   \
         } else {                                                               \
           Object* new_object = NULL;  /* May not be a real Object pointer. */  \
           if (where == kNewObject) {                                           \
             ASSIGN_DEST_SPACE(space_number)                                    \
             ReadObject(space_number, dest_space, &new_object);                 \
           } else if (where == kRootArray) {                                    \
             int root_id = source_->GetInt();                                   \
             new_object = isolate->heap()->roots_address()[root_id];            \
           } else if (where == kPartialSnapshotCache) {                         \
             int cache_index = source_->GetInt();                               \
             new_object = isolate->serialize_partial_snapshot_cache()           \
                 [cache_index];                                                 \
           } else if (where == kExternalReference) {                            \
             int reference_id = source_->GetInt();                              \
             Address address = external_reference_decoder_->                    \
                 Decode(reference_id);                                          \
             new_object = reinterpret_cast<Object*>(address);                   \
           } else if (where == kBackref) {                                      \
-            emit_write_barrier =                                               \
-              (space_number == NEW_SPACE && source_space != NEW_SPACE);        \
+            emit_write_barrier = (space_number == NEW_SPACE &&                 \
+                                  source_space != NEW_SPACE &&                 \
+                                  source_space != CELL_SPACE);                 \
             new_object = GetAddressFromEnd(data & kSpaceMask);                 \
           } else {                                                             \
             ASSERT(where == kFromStart);                                       \
             if (offset_from_start == kUnknownOffsetFromStart) {                \
-              emit_write_barrier =                                             \
-                (space_number == NEW_SPACE && source_space != NEW_SPACE);      \
+              emit_write_barrier = (space_number == NEW_SPACE &&               \
+                                    source_space != NEW_SPACE &&               \
+                                    source_space != CELL_SPACE);               \
               new_object = GetAddressFromStart(data & kSpaceMask);             \
             } else {                                                           \
               Address object_address = pages_[space_number][0] +               \
                   (offset_from_start << kObjectAlignmentBits);                 \
               new_object = HeapObject::FromAddress(object_address);            \
             }                                                                  \
           }                                                                    \
           if (within == kFirstInstruction) {                                   \
             Code* new_code_object = reinterpret_cast<Code*>(new_object);       \
             new_object = reinterpret_cast<Object*>(                            \
@@ skipping 734 matching lines @@
       fullness_[space] = RoundUp(fullness_[space], Page::kPageSize);
     }
   }
   int allocation_address = fullness_[space];
   fullness_[space] = allocation_address + size;
   return allocation_address;
 }
 
 
 } }  // namespace v8::internal