Cardmarking writebarrier.

src/objects-inl.h

 // Copyright 2006-2008 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 741 matching lines @@
 
 // CONDITIONAL_WRITE_BARRIER must be issued after the actual
 // write due to the assert validating the written value.
 #define CONDITIONAL_WRITE_BARRIER(object, offset, mode) \
   if (mode == UPDATE_WRITE_BARRIER) { \
     Heap::RecordWrite(object->address(), offset); \
   } else { \
     ASSERT(mode == SKIP_WRITE_BARRIER); \
     ASSERT(Heap::InNewSpace(object) || \
            !Heap::InNewSpace(READ_FIELD(object, offset)) || \
-           Page::IsRSetSet(object->address(), offset)); \
+           Page::FromAddress(object->address())->           \
+               IsRegionDirty(object->address() + offset));  \
   }
 
 #define READ_DOUBLE_FIELD(p, offset) \
   (*reinterpret_cast<double*>(FIELD_ADDR(p, offset)))
 
 #define WRITE_DOUBLE_FIELD(p, offset, value) \
   (*reinterpret_cast<double*>(FIELD_ADDR(p, offset)) = value)
 
 #define READ_INT_FIELD(p, offset) \
   (*reinterpret_cast<int*>(FIELD_ADDR(p, offset)))
@@ skipping 265 matching lines @@
 
 Address MapWord::ToEncodedAddress() {
   return reinterpret_cast<Address>(value_);
 }
 
 
 #ifdef DEBUG
 void HeapObject::VerifyObjectField(int offset) {
   VerifyPointer(READ_FIELD(this, offset));
 }
+
+void HeapObject::VerifySmiField(int offset) {
+  ASSERT(READ_FIELD(this, offset)->IsSmi());
+}
 #endif
 
 
 Map* HeapObject::map() {
   return map_word().ToMap();
 }
 
 
 void HeapObject::set_map(Map* value) {
   set_map_word(MapWord::FromMap(value));
 }
 
 
 MapWord HeapObject::map_word() {
   return MapWord(reinterpret_cast<uintptr_t>(READ_FIELD(this, kMapOffset)));
 }
 
 
 void HeapObject::set_map_word(MapWord map_word) {
-  // WRITE_FIELD does not update the remembered set, but there is no need
+  // WRITE_FIELD does not invoke write barrier, but there is no need
   // here.
   WRITE_FIELD(this, kMapOffset, reinterpret_cast<Object*>(map_word.value_));
 }
 
 
 HeapObject* HeapObject::FromAddress(Address address) {
   ASSERT_TAG_ALIGNED(address);
   return reinterpret_cast<HeapObject*>(address + kHeapObjectTag);
 }
 
@@ skipping 77 matching lines @@
 
 
 int HeapNumber::get_sign() {
   return READ_INT_FIELD(this, kExponentOffset) & kSignMask;
 }
 
 
 ACCESSORS(JSObject, properties, FixedArray, kPropertiesOffset)
 
 
-Array* JSObject::elements() {
+HeapObject* JSObject::elements() {
   Object* array = READ_FIELD(this, kElementsOffset);
   // In the assert below Dictionary is covered under FixedArray.
   ASSERT(array->IsFixedArray() || array->IsPixelArray() ||
          array->IsExternalArray());
-  return reinterpret_cast<Array*>(array);
+  return reinterpret_cast<HeapObject*>(array);
 }
 
 
-void JSObject::set_elements(Array* value, WriteBarrierMode mode) {
+void JSObject::set_elements(HeapObject* value, WriteBarrierMode mode) {
   // In the assert below Dictionary is covered under FixedArray.
   ASSERT(value->IsFixedArray() || value->IsPixelArray() ||
          value->IsExternalArray());
   WRITE_FIELD(this, kElementsOffset, value);
   CONDITIONAL_WRITE_BARRIER(this, kElementsOffset, mode);
 }
 
 
 void JSObject::initialize_properties() {
   ASSERT(!Heap::InNewSpace(Heap::empty_fixed_array()));
@@ skipping 150 matching lines @@
     WRITE_FIELD(this, offset, value);
   }
 }
 
 
 bool JSObject::HasFastProperties() {
   return !properties()->IsDictionary();
 }
 
 
-bool Array::IndexFromObject(Object* object, uint32_t* index) {
-  if (object->IsSmi()) {
-    int value = Smi::cast(object)->value();
+bool Object::ToArrayIndex(uint32_t* index) {
+  if (IsSmi()) {
+    int value = Smi::cast(this)->value();
     if (value < 0) return false;
     *index = value;
     return true;
   }
-  if (object->IsHeapNumber()) {
-    double value = HeapNumber::cast(object)->value();
+  if (IsHeapNumber()) {
+    double value = HeapNumber::cast(this)->value();
     uint32_t uint_value = static_cast<uint32_t>(value);
     if (value == static_cast<double>(uint_value)) {
       *index = uint_value;
       return true;
     }
   }
   return false;
 }
 
 
@@ skipping 294 matching lines @@
 #undef MAKE_STRUCT_CAST
 
 
 template <typename Shape, typename Key>
 HashTable<Shape, Key>* HashTable<Shape, Key>::cast(Object* obj) {
   ASSERT(obj->IsHashTable());
   return reinterpret_cast<HashTable*>(obj);
 }
 
 
-INT_ACCESSORS(Array, length, kLengthOffset)
+SMI_ACCESSORS(FixedArray, length, kLengthOffset)
+SMI_ACCESSORS(ByteArray, length, kLengthOffset)
+
+INT_ACCESSORS(PixelArray, length, kLengthOffset)
+INT_ACCESSORS(ExternalArray, length, kLengthOffset)
 
 
 SMI_ACCESSORS(String, length, kLengthOffset)
 
 
 uint32_t String::hash_field() {
   return READ_UINT32_FIELD(this, kHashFieldOffset);
 }
 
 
 void String::set_hash_field(uint32_t value) {
   WRITE_UINT32_FIELD(this, kHashFieldOffset, value);
+#if V8_HOST_ARCH_64_BIT
+  WRITE_UINT32_FIELD(this, kHashFieldOffset + kIntSize, 0);
+#endif
 }
 
 
 bool String::Equals(String* other) {
   if (other == this) return true;
   if (StringShape(this).IsSymbol() && StringShape(other).IsSymbol()) {
     return false;
   }
   return SlowEquals(other);
 }
@@ skipping 758 matching lines @@
 BOOL_ACCESSORS(SharedFunctionInfo, start_position_and_type, is_toplevel,
                kIsTopLevelBit)
 BOOL_GETTER(SharedFunctionInfo, compiler_hints,
             has_only_simple_this_property_assignments,
             kHasOnlySimpleThisPropertyAssignments)
 BOOL_ACCESSORS(SharedFunctionInfo,
                compiler_hints,
                try_full_codegen,
                kTryFullCodegen)
 
-INT_ACCESSORS(SharedFunctionInfo, length, kLengthOffset)
-INT_ACCESSORS(SharedFunctionInfo, formal_parameter_count,
+#if V8_HOST_ARCH_32_BIT
+SMI_ACCESSORS(SharedFunctionInfo, length, kLengthOffset)
+SMI_ACCESSORS(SharedFunctionInfo, formal_parameter_count,
               kFormalParameterCountOffset)
-INT_ACCESSORS(SharedFunctionInfo, expected_nof_properties,
+SMI_ACCESSORS(SharedFunctionInfo, expected_nof_properties,
               kExpectedNofPropertiesOffset)
-INT_ACCESSORS(SharedFunctionInfo, num_literals, kNumLiteralsOffset)
-INT_ACCESSORS(SharedFunctionInfo, start_position_and_type,
+SMI_ACCESSORS(SharedFunctionInfo, num_literals, kNumLiteralsOffset)
+SMI_ACCESSORS(SharedFunctionInfo, start_position_and_type,
               kStartPositionAndTypeOffset)
-INT_ACCESSORS(SharedFunctionInfo, end_position, kEndPositionOffset)
-INT_ACCESSORS(SharedFunctionInfo, function_token_position,
+SMI_ACCESSORS(SharedFunctionInfo, end_position, kEndPositionOffset)
+SMI_ACCESSORS(SharedFunctionInfo, function_token_position,
               kFunctionTokenPositionOffset)
-INT_ACCESSORS(SharedFunctionInfo, compiler_hints,
+SMI_ACCESSORS(SharedFunctionInfo, compiler_hints,
               kCompilerHintsOffset)
-INT_ACCESSORS(SharedFunctionInfo, this_property_assignments_count,
+SMI_ACCESSORS(SharedFunctionInfo, this_property_assignments_count,
               kThisPropertyAssignmentsCountOffset)
+#else
 
+#define PSEUDO_SMI_ACCESSORS_LO(holder, name, offset)             \
+  int holder::name() {                                            \
+    int value = READ_INT_FIELD(this, offset);                     \
+    ASSERT(kHeapObjectTag == 1);                                  \
+    ASSERT((value & kHeapObjectTag) == 0);                        \
+    return value >> 1;                                            \
+  }                                                               \
+  void holder::set_##name(int value) {                            \
+    ASSERT(kHeapObjectTag == 1);                                  \
+    ASSERT((value & 0xC0000000) == 0xC0000000 ||                  \
+           (value & 0xC0000000) == 0x000000000);                  \
+    WRITE_INT_FIELD(this,                                         \
+                    offset,                                       \
+                    (value << 1) & ~kHeapObjectTag);              \
+  }
+
+#define PSEUDO_SMI_ACCESSORS_HI(holder, name, offset) \
+  INT_ACCESSORS(holder, name, offset)
+
+
+
+PSEUDO_SMI_ACCESSORS_LO(SharedFunctionInfo, length, kLengthOffset)
+PSEUDO_SMI_ACCESSORS_HI(SharedFunctionInfo, formal_parameter_count,
+              kFormalParameterCountOffset)
+
+PSEUDO_SMI_ACCESSORS_LO(SharedFunctionInfo, expected_nof_properties,
+              kExpectedNofPropertiesOffset)
+PSEUDO_SMI_ACCESSORS_HI(SharedFunctionInfo, num_literals, kNumLiteralsOffset)
+
+PSEUDO_SMI_ACCESSORS_LO(SharedFunctionInfo, start_position_and_type,
+              kStartPositionAndTypeOffset)
+PSEUDO_SMI_ACCESSORS_HI(SharedFunctionInfo, end_position, kEndPositionOffset)
+
+PSEUDO_SMI_ACCESSORS_LO(SharedFunctionInfo, function_token_position,
+              kFunctionTokenPositionOffset)
+PSEUDO_SMI_ACCESSORS_HI(SharedFunctionInfo, compiler_hints,
+              kCompilerHintsOffset)
+
+PSEUDO_SMI_ACCESSORS_LO(SharedFunctionInfo, this_property_assignments_count,
+              kThisPropertyAssignmentsCountOffset)
+#endif
 
 ACCESSORS(CodeCache, default_cache, FixedArray, kDefaultCacheOffset)
 ACCESSORS(CodeCache, normal_type_cache, Object, kNormalTypeCacheOffset)
 
 bool Script::HasValidSource() {
   Object* src = this->source();
   if (!src->IsString()) return true;
   String* src_str = String::cast(src);
   if (!StringShape(src_str).IsExternal()) return true;
   if (src_str->IsAsciiRepresentation()) {
@@ skipping 293 matching lines @@
 
 
 void JSRegExp::SetDataAt(int index, Object* value) {
   ASSERT(TypeTag() != NOT_COMPILED);
   ASSERT(index >= kDataIndex);  // Only implementation data can be set this way.
   FixedArray::cast(data())->set(index, value);
 }
 
 
 JSObject::ElementsKind JSObject::GetElementsKind() {
-  Array* array = elements();
+  HeapObject* array = elements();
   if (array->IsFixedArray()) {
     // FAST_ELEMENTS or DICTIONARY_ELEMENTS are both stored in a FixedArray.
     if (array->map() == Heap::fixed_array_map()) {
       return FAST_ELEMENTS;
     }
     ASSERT(array->IsDictionary());
     return DICTIONARY_ELEMENTS;
   }
   if (array->IsExternalArray()) {
     switch (array->map()->instance_type()) {
@@ skipping 102 matching lines @@
   return StringDictionary::cast(properties());
 }
 
 
 NumberDictionary* JSObject::element_dictionary() {
   ASSERT(HasDictionaryElements());
   return NumberDictionary::cast(elements());
 }
 
 
+bool String::IsHashFieldComputed(uint32_t field) {
+  return (field & kHashNotComputedMask) == 0;
+}
+
+
 bool String::HasHashCode() {
-  return (hash_field() & kHashComputedMask) != 0;
+  return IsHashFieldComputed(hash_field());
 }
 
 
 uint32_t String::Hash() {
   // Fast case: has hash code already been computed?
   uint32_t field = hash_field();
-  if (field & kHashComputedMask) return field >> kHashShift;
+  if (IsHashFieldComputed(field)) return field >> kHashShift;
   // Slow case: compute hash code and set it.
   return ComputeAndSetHash();
 }
 
 
 StringHasher::StringHasher(int length)
   : length_(length),
     raw_running_hash_(0),
     array_index_(0),
     is_array_index_(0 < length_ && length_ <= String::kMaxArrayIndexSize),
@@ skipping 52 matching lines @@
   result += (result << 15);
   if (result == 0) {
     result = 27;
   }
   return result;
 }
 
 
 bool String::AsArrayIndex(uint32_t* index) {
   uint32_t field = hash_field();
-  if ((field & kHashComputedMask) && !(field & kIsArrayIndexMask)) return false;
+  if (IsHashFieldComputed(field) && !(field & kIsArrayIndexMask)) return false;
   return SlowAsArrayIndex(index);
 }
 
 
 Object* JSObject::GetPrototype() {
   return JSObject::cast(this)->map()->prototype();
 }
 
 
 PropertyAttributes JSObject::GetPropertyAttribute(String* key) {
@@ skipping 103 matching lines @@
   // No write barrier is needed since empty_fixed_array is not in new space.
   // Please note this function is used during marking:
   //  - MarkCompactCollector::MarkUnmarkedObject
   ASSERT(!Heap::InNewSpace(Heap::raw_unchecked_empty_fixed_array()));
   WRITE_FIELD(this, kCodeCacheOffset, Heap::raw_unchecked_empty_fixed_array());
 }
 
 
 void JSArray::EnsureSize(int required_size) {
   ASSERT(HasFastElements());
-  Array* elts = elements();
+  FixedArray* elts = FixedArray::cast(elements());
   const int kArraySizeThatFitsComfortablyInNewSpace = 128;
   if (elts->length() < required_size) {
     // Doubling in size would be overkill, but leave some slack to avoid
     // constantly growing.
     Expand(required_size + (required_size >> 3));
     // It's a performance benefit to keep a frequently used array in new-space.
   } else if (!Heap::new_space()->Contains(elts) &&
              required_size < kArraySizeThatFitsComfortablyInNewSpace) {
     // Expand will allocate a new backing store in new space even if the size
     // we asked for isn't larger than what we had before.
@@ skipping 36 matching lines @@
 #undef WRITE_INT_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_