Estimate a (close) upper bound on the size of black-marked objects on each page.

src/objects.cc

 // 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 818 matching lines @@
     self->Hash();  // Force regeneration of the hash value.
     // Now morph this external string into a external symbol.
     this->set_map(is_ascii ?
                   heap->external_symbol_with_ascii_data_map() :
                   heap->external_symbol_map());
   }
 
   // Fill the remainder of the string with dead wood.
   int new_size = this->Size();  // Byte size of the external String object.
   heap->CreateFillerObjectAt(this->address() + new_size, size - new_size);
+  if (Marking::IsBlack(Marking::MarkBitFrom(this))) {
+    MemoryChunk::IncrementLiveBytes(this->address(), new_size - size);
+  }
   return true;
 }
 
 
 bool String::MakeExternal(v8::String::ExternalAsciiStringResource* resource) {
 #ifdef DEBUG
   if (FLAG_enable_slow_asserts) {
     // Assert that the resource and the string are equivalent.
     ASSERT(static_cast<size_t>(this->length()) == resource->length());
     ScopedVector<char> smart_chars(this->length());
@@ skipping 26 matching lines @@
   // was a symbol to start with.
   if (is_symbol) {
     self->Hash();  // Force regeneration of the hash value.
     // Now morph this external string into a external symbol.
     this->set_map(heap->external_ascii_symbol_map());
   }
 
   // Fill the remainder of the string with dead wood.
   int new_size = this->Size();  // Byte size of the external String object.
   heap->CreateFillerObjectAt(this->address() + new_size, size - new_size);
+  if (Marking::IsBlack(Marking::MarkBitFrom(this))) {
+    MemoryChunk::IncrementLiveBytes(this->address(), new_size - size);
+  }
+
   return true;
 }
 
 
 void String::StringShortPrint(StringStream* accumulator) {
   int len = length();
   if (len > kMaxShortPrintLength) {
     accumulator->Add("<Very long string[%u]>", len);
     return;
   }
@@ skipping 1786 matching lines @@
 
   // We have now successfully allocated all the necessary objects.
   // Changes can now be made with the guarantee that all of them take effect.
 
   // Resize the object in the heap if necessary.
   int new_instance_size = new_map->instance_size();
   int instance_size_delta = map_of_this->instance_size() - new_instance_size;
   ASSERT(instance_size_delta >= 0);
   current_heap->CreateFillerObjectAt(this->address() + new_instance_size,
                                      instance_size_delta);
+  if (Marking::IsBlack(Marking::MarkBitFrom(this))) {
+    MemoryChunk::IncrementLiveBytes(this->address(), -instance_size_delta);
+  }
+
 
   set_map(new_map);
   new_map->clear_instance_descriptors();
 
   set_properties(dictionary);
 
   current_heap->isolate()->counters()->props_to_dictionary()->Increment();
 
 #ifdef DEBUG
   if (FLAG_trace_normalization) {
@@ skipping 7921 matching lines @@
   if (break_point_objects()->IsUndefined()) return 0;
   // Single beak point.
   if (!break_point_objects()->IsFixedArray()) return 1;
   // Multiple break points.
   return FixedArray::cast(break_point_objects())->length();
 }
 #endif
 
 
 } }  // namespace v8::internal