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// Copyright 2017 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_OBJECTS_FIXED_ARRAY_H_
#define V8_OBJECTS_FIXED_ARRAY_H_
#include "src/handles/maybe-handles.h"
#include "src/objects/instance-type.h"
#include "src/objects/objects.h"
#include "src/objects/smi.h"
// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"
namespace v8 {
namespace internal {
#define FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(V) \
V(BYTECODE_ARRAY_CONSTANT_POOL_SUB_TYPE) \
V(BYTECODE_ARRAY_HANDLER_TABLE_SUB_TYPE) \
V(CODE_STUBS_TABLE_SUB_TYPE) \
V(COMPILATION_CACHE_TABLE_SUB_TYPE) \
V(CONTEXT_SUB_TYPE) \
V(COPY_ON_WRITE_SUB_TYPE) \
V(DEOPTIMIZATION_DATA_SUB_TYPE) \
V(DESCRIPTOR_ARRAY_SUB_TYPE) \
V(EMBEDDED_OBJECT_SUB_TYPE) \
V(ENUM_CACHE_SUB_TYPE) \
V(ENUM_INDICES_CACHE_SUB_TYPE) \
V(DEPENDENT_CODE_SUB_TYPE) \
V(DICTIONARY_ELEMENTS_SUB_TYPE) \
V(DICTIONARY_PROPERTIES_SUB_TYPE) \
V(EMPTY_PROPERTIES_DICTIONARY_SUB_TYPE) \
V(PACKED_ELEMENTS_SUB_TYPE) \
V(FAST_PROPERTIES_SUB_TYPE) \
V(FAST_TEMPLATE_INSTANTIATIONS_CACHE_SUB_TYPE) \
V(HANDLER_TABLE_SUB_TYPE) \
V(JS_COLLECTION_SUB_TYPE) \
V(JS_WEAK_COLLECTION_SUB_TYPE) \
V(NOSCRIPT_SHARED_FUNCTION_INFOS_SUB_TYPE) \
V(NUMBER_STRING_CACHE_SUB_TYPE) \
V(OBJECT_TO_CODE_SUB_TYPE) \
V(OPTIMIZED_CODE_LITERALS_SUB_TYPE) \
V(OPTIMIZED_CODE_MAP_SUB_TYPE) \
V(PROTOTYPE_USERS_SUB_TYPE) \
V(REGEXP_MULTIPLE_CACHE_SUB_TYPE) \
V(RETAINED_MAPS_SUB_TYPE) \
V(SCOPE_INFO_SUB_TYPE) \
V(SCRIPT_LIST_SUB_TYPE) \
V(SERIALIZED_OBJECTS_SUB_TYPE) \
V(SHARED_FUNCTION_INFOS_SUB_TYPE) \
V(SINGLE_CHARACTER_STRING_CACHE_SUB_TYPE) \
V(SLOW_TEMPLATE_INSTANTIATIONS_CACHE_SUB_TYPE) \
V(STRING_SPLIT_CACHE_SUB_TYPE) \
V(TEMPLATE_INFO_SUB_TYPE) \
V(FEEDBACK_METADATA_SUB_TYPE) \
V(WEAK_NEW_SPACE_OBJECT_TO_CODE_SUB_TYPE)
enum FixedArraySubInstanceType {
#define DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE(name) name,
FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE)
#undef DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE
LAST_FIXED_ARRAY_SUB_TYPE = WEAK_NEW_SPACE_OBJECT_TO_CODE_SUB_TYPE
};
#include "torque-generated/src/objects/fixed-array-tq.inc"
// Common superclass for FixedArrays that allow implementations to share
// common accessors and some code paths.
class FixedArrayBase
: public TorqueGeneratedFixedArrayBase<FixedArrayBase, HeapObject> {
public:
// Get and set the length using acquire loads and release stores.
DECL_SYNCHRONIZED_INT_ACCESSORS(length)
inline Object unchecked_synchronized_length() const;
static int GetMaxLengthForNewSpaceAllocation(ElementsKind kind);
V8_EXPORT_PRIVATE bool IsCowArray() const;
// Maximal allowed size, in bytes, of a single FixedArrayBase.
// Prevents overflowing size computations, as well as extreme memory
// consumption. It's either (512Mb - kTaggedSize) or (1024Mb - kTaggedSize).
// -kTaggedSize is here to ensure that this max size always fits into Smi
// which is necessary for being able to create a free space filler for the
// whole array of kMaxSize.
static const int kMaxSize = 128 * kTaggedSize * MB - kTaggedSize;
STATIC_ASSERT(Smi::IsValid(kMaxSize));
protected:
TQ_OBJECT_CONSTRUCTORS(FixedArrayBase)
inline FixedArrayBase(Address ptr,
HeapObject::AllowInlineSmiStorage allow_smi);
};
// FixedArray describes fixed-sized arrays with element type Object.
class FixedArray
: public TorqueGeneratedFixedArray<FixedArray, FixedArrayBase> {
public:
// Setter and getter for elements.
inline Object get(int index) const;
inline Object get(IsolateRoot isolate, int index) const;
static inline Handle<Object> get(FixedArray array, int index,
Isolate* isolate);
// Return a grown copy if the index is bigger than the array's length.
V8_EXPORT_PRIVATE static Handle<FixedArray> SetAndGrow(
Isolate* isolate, Handle<FixedArray> array, int index,
Handle<Object> value);
// Synchronized setters and getters.
inline Object synchronized_get(int index) const;
inline Object synchronized_get(IsolateRoot isolate, int index) const;
// Currently only Smis are written with release semantics, hence we can avoid
// a write barrier.
inline void synchronized_set(int index, Smi value);
// Setter that uses write barrier.
inline void set(int index, Object value);
inline bool is_the_hole(Isolate* isolate, int index);
// Setter that doesn't need write barrier.
inline void set(int index, Smi value);
// Setter with explicit barrier mode.
inline void set(int index, Object value, WriteBarrierMode mode);
// Setters for frequently used oddballs located in old space.
inline void set_undefined(int index);
inline void set_undefined(Isolate* isolate, int index);
inline void set_null(int index);
inline void set_null(Isolate* isolate, int index);
inline void set_the_hole(int index);
inline void set_the_hole(Isolate* isolate, int index);
inline ObjectSlot GetFirstElementAddress();
inline bool ContainsOnlySmisOrHoles();
// Gives access to raw memory which stores the array's data.
inline ObjectSlot data_start();
inline void MoveElements(Isolate* isolate, int dst_index, int src_index,
int len, WriteBarrierMode mode);
inline void CopyElements(Isolate* isolate, int dst_index, FixedArray src,
int src_index, int len, WriteBarrierMode mode);
inline void FillWithHoles(int from, int to);
// Shrink the array and insert filler objects. {new_length} must be > 0.
V8_EXPORT_PRIVATE void Shrink(Isolate* isolate, int new_length);
// If {new_length} is 0, return the canonical empty FixedArray. Otherwise
// like above.
static Handle<FixedArray> ShrinkOrEmpty(Isolate* isolate,
Handle<FixedArray> array,
int new_length);
// Copy a sub array from the receiver to dest.
V8_EXPORT_PRIVATE void CopyTo(int pos, FixedArray dest, int dest_pos,
int len) const;
// Garbage collection support.
static constexpr int SizeFor(int length) {
return kHeaderSize + length * kTaggedSize;
}
// Code Generation support.
static constexpr int OffsetOfElementAt(int index) {
STATIC_ASSERT(kObjectsOffset == SizeFor(0));
return SizeFor(index);
}
// Garbage collection support.
inline ObjectSlot RawFieldOfElementAt(int index);
// Maximally allowed length of a FixedArray.
static const int kMaxLength = (kMaxSize - kHeaderSize) / kTaggedSize;
static_assert(Internals::IsValidSmi(kMaxLength),
"FixedArray maxLength not a Smi");
// Maximally allowed length for regular (non large object space) object.
STATIC_ASSERT(kMaxRegularHeapObjectSize < kMaxSize);
static const int kMaxRegularLength =
(kMaxRegularHeapObjectSize - kHeaderSize) / kTaggedSize;
// Dispatched behavior.
DECL_PRINTER(FixedArray)
int AllocatedSize();
class BodyDescriptor;
static constexpr int kObjectsOffset = kHeaderSize;
protected:
// Set operation on FixedArray without using write barriers. Can
// only be used for storing old space objects or smis.
static inline void NoWriteBarrierSet(FixedArray array, int index,
Object value);
private:
STATIC_ASSERT(kHeaderSize == Internals::kFixedArrayHeaderSize);
inline void set_undefined(ReadOnlyRoots ro_roots, int index);
inline void set_null(ReadOnlyRoots ro_roots, int index);
inline void set_the_hole(ReadOnlyRoots ro_roots, int index);
TQ_OBJECT_CONSTRUCTORS(FixedArray)
};
// FixedArray alias added only because of IsFixedArrayExact() predicate, which
// checks for the exact instance type FIXED_ARRAY_TYPE instead of a range
// check: [FIRST_FIXED_ARRAY_TYPE, LAST_FIXED_ARRAY_TYPE].
class FixedArrayExact final : public FixedArray {};
// FixedDoubleArray describes fixed-sized arrays with element type double.
class FixedDoubleArray
: public TorqueGeneratedFixedDoubleArray<FixedDoubleArray, FixedArrayBase> {
public:
// Setter and getter for elements.
inline double get_scalar(int index);
inline uint64_t get_representation(int index);
static inline Handle<Object> get(FixedDoubleArray array, int index,
Isolate* isolate);
inline void set(int index, double value);
inline void set_the_hole(Isolate* isolate, int index);
inline void set_the_hole(int index);
// Checking for the hole.
inline bool is_the_hole(Isolate* isolate, int index);
inline bool is_the_hole(int index);
// Garbage collection support.
inline static int SizeFor(int length) {
return kHeaderSize + length * kDoubleSize;
}
inline void MoveElements(Isolate* isolate, int dst_index, int src_index,
int len, WriteBarrierMode mode);
inline void FillWithHoles(int from, int to);
// Code Generation support.
static int OffsetOfElementAt(int index) { return SizeFor(index); }
// Start offset of elements.
static constexpr int kFloatsOffset = kHeaderSize;
// Maximally allowed length of a FixedDoubleArray.
static const int kMaxLength = (kMaxSize - kHeaderSize) / kDoubleSize;
static_assert(Internals::IsValidSmi(kMaxLength),
"FixedDoubleArray maxLength not a Smi");
// Dispatched behavior.
DECL_PRINTER(FixedDoubleArray)
DECL_VERIFIER(FixedDoubleArray)
class BodyDescriptor;
TQ_OBJECT_CONSTRUCTORS(FixedDoubleArray)
};
// WeakFixedArray describes fixed-sized arrays with element type
// MaybeObject.
class WeakFixedArray
: public TorqueGeneratedWeakFixedArray<WeakFixedArray, HeapObject> {
public:
inline MaybeObject Get(int index) const;
inline MaybeObject Get(IsolateRoot isolate, int index) const;
inline void Set(
int index, MaybeObject value,
WriteBarrierMode mode = WriteBarrierMode::UPDATE_WRITE_BARRIER);
// Get and set the length using acquire loads and release stores.
DECL_SYNCHRONIZED_INT_ACCESSORS(length)
// Gives access to raw memory which stores the array's data.
inline MaybeObjectSlot data_start();
inline MaybeObjectSlot RawFieldOfElementAt(int index);
inline void CopyElements(Isolate* isolate, int dst_index, WeakFixedArray src,
int src_index, int len, WriteBarrierMode mode);
DECL_PRINTER(WeakFixedArray)
DECL_VERIFIER(WeakFixedArray)
class BodyDescriptor;
static const int kMaxLength =
(FixedArray::kMaxSize - kHeaderSize) / kTaggedSize;
static_assert(Internals::IsValidSmi(kMaxLength),
"WeakFixedArray maxLength not a Smi");
int AllocatedSize();
static int OffsetOfElementAt(int index) {
STATIC_ASSERT(kObjectsOffset == SizeFor(0));
return SizeFor(index);
}
private:
friend class Heap;
static const int kFirstIndex = 1;
TQ_OBJECT_CONSTRUCTORS(WeakFixedArray)
};
// WeakArrayList is like a WeakFixedArray with static convenience methods for
// adding more elements. length() returns the number of elements in the list and
// capacity() returns the allocated size. The number of elements is stored at
// kLengthOffset and is updated with every insertion. The array grows
// dynamically with O(1) amortized insertion.
class WeakArrayList
: public TorqueGeneratedWeakArrayList<WeakArrayList, HeapObject> {
public:
NEVER_READ_ONLY_SPACE
DECL_PRINTER(WeakArrayList)
V8_EXPORT_PRIVATE static Handle<WeakArrayList> AddToEnd(
Isolate* isolate, Handle<WeakArrayList> array,
const MaybeObjectHandle& value);
// A version that adds to elements. This ensures that the elements are
// inserted atomically w.r.t GC.
V8_EXPORT_PRIVATE static Handle<WeakArrayList> AddToEnd(
Isolate* isolate, Handle<WeakArrayList> array,
const MaybeObjectHandle& value1, const MaybeObjectHandle& value2);
// Appends an element to the array and possibly compacts and shrinks live weak
// references to the start of the collection. Only use this method when
// indices to elements can change.
static Handle<WeakArrayList> Append(
Isolate* isolate, Handle<WeakArrayList> array,
const MaybeObjectHandle& value,
AllocationType allocation = AllocationType::kYoung);
// Compact weak references to the beginning of the array.
V8_EXPORT_PRIVATE void Compact(Isolate* isolate);
inline MaybeObject Get(int index) const;
inline MaybeObject Get(IsolateRoot isolate, int index) const;
// Set the element at index to obj. The underlying array must be large enough.
// If you need to grow the WeakArrayList, use the static AddToEnd() method
// instead.
inline void Set(int index, MaybeObject value,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
static constexpr int SizeForCapacity(int capacity) {
return SizeFor(capacity);
}
static constexpr int CapacityForLength(int length) {
return length + std::max(length / 2, 2);
}
// Gives access to raw memory which stores the array's data.
inline MaybeObjectSlot data_start();
inline void CopyElements(Isolate* isolate, int dst_index, WeakArrayList src,
int src_index, int len, WriteBarrierMode mode);
V8_EXPORT_PRIVATE bool IsFull();
// Get and set the capacity using acquire loads and release stores.
DECL_SYNCHRONIZED_INT_ACCESSORS(capacity)
int AllocatedSize();
class BodyDescriptor;
static const int kMaxCapacity =
(FixedArray::kMaxSize - kHeaderSize) / kTaggedSize;
static Handle<WeakArrayList> EnsureSpace(
Isolate* isolate, Handle<WeakArrayList> array, int length,
AllocationType allocation = AllocationType::kYoung);
// Returns the number of non-cleaned weak references in the array.
int CountLiveWeakReferences() const;
// Returns the number of non-cleaned elements in the array.
int CountLiveElements() const;
// Returns whether an entry was found and removed. Will move the elements
// around in the array - this method can only be used in cases where the user
// doesn't care about the indices! Users should make sure there are no
// duplicates.
V8_EXPORT_PRIVATE bool RemoveOne(const MaybeObjectHandle& value);
class Iterator;
private:
static int OffsetOfElementAt(int index) {
return kHeaderSize + index * kTaggedSize;
}
TQ_OBJECT_CONSTRUCTORS(WeakArrayList)
};
class WeakArrayList::Iterator {
public:
explicit Iterator(WeakArrayList array) : index_(0), array_(array) {}
Iterator(const Iterator&) = delete;
Iterator& operator=(const Iterator&) = delete;
inline HeapObject Next();
private:
int index_;
WeakArrayList array_;
#ifdef DEBUG
DisallowHeapAllocation no_gc_;
#endif // DEBUG
};
// Generic array grows dynamically with O(1) amortized insertion.
//
// ArrayList is a FixedArray with static convenience methods for adding more
// elements. The Length() method returns the number of elements in the list, not
// the allocated size. The number of elements is stored at kLengthIndex and is
// updated with every insertion. The elements of the ArrayList are stored in the
// underlying FixedArray starting at kFirstIndex.
class ArrayList : public TorqueGeneratedArrayList<ArrayList, FixedArray> {
public:
V8_EXPORT_PRIVATE static Handle<ArrayList> Add(Isolate* isolate,
Handle<ArrayList> array,
Handle<Object> obj);
V8_EXPORT_PRIVATE static Handle<ArrayList> Add(Isolate* isolate,
Handle<ArrayList> array,
Handle<Object> obj1,
Handle<Object> obj2);
static Handle<ArrayList> New(Isolate* isolate, int size);
// Returns the number of elements in the list, not the allocated size, which
// is length(). Lower and upper case length() return different results!
inline int Length() const;
// Sets the Length() as used by Elements(). Does not change the underlying
// storage capacity, i.e., length().
inline void SetLength(int length);
inline Object Get(int index) const;
inline Object Get(IsolateRoot isolate, int index) const;
inline ObjectSlot Slot(int index);
// Set the element at index to obj. The underlying array must be large enough.
// If you need to grow the ArrayList, use the static Add() methods instead.
inline void Set(int index, Object obj,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
// Set the element at index to undefined. This does not change the Length().
inline void Clear(int index, Object undefined);
// Return a copy of the list of size Length() without the first entry. The
// number returned by Length() is stored in the first entry.
static Handle<FixedArray> Elements(Isolate* isolate, Handle<ArrayList> array);
static const int kHeaderFields = 1;
private:
static Handle<ArrayList> EnsureSpace(Isolate* isolate,
Handle<ArrayList> array, int length);
static const int kLengthIndex = 0;
static const int kFirstIndex = 1;
STATIC_ASSERT(kHeaderFields == kFirstIndex);
TQ_OBJECT_CONSTRUCTORS(ArrayList)
};
enum SearchMode { ALL_ENTRIES, VALID_ENTRIES };
template <SearchMode search_mode, typename T>
inline int Search(T* array, Name name, int valid_entries = 0,
int* out_insertion_index = nullptr,
bool concurrent_search = false);
// ByteArray represents fixed sized byte arrays. Used for the relocation info
// that is attached to code objects.
class ByteArray : public TorqueGeneratedByteArray<ByteArray, FixedArrayBase> {
public:
inline int Size();
// Setter and getter.
inline byte get(int index) const;
inline void set(int index, byte value);
// Copy in / copy out whole byte slices.
inline void copy_out(int index, byte* buffer, int length);
inline void copy_in(int index, const byte* buffer, int length);
// Treat contents as an int array.
inline int get_int(int index) const;
inline void set_int(int index, int value);
inline uint32_t get_uint32(int index) const;
inline void set_uint32(int index, uint32_t value);
inline uint32_t get_uint32_relaxed(int index) const;
inline void set_uint32_relaxed(int index, uint32_t value);
// Clear uninitialized padding space. This ensures that the snapshot content
// is deterministic.
inline void clear_padding();
static int SizeFor(int length) {
return OBJECT_POINTER_ALIGN(kHeaderSize + length);
}
// We use byte arrays for free blocks in the heap. Given a desired size in
// bytes that is a multiple of the word size and big enough to hold a byte
// array, this function returns the number of elements a byte array should
// have.
static int LengthFor(int size_in_bytes) {
DCHECK(IsAligned(size_in_bytes, kTaggedSize));
DCHECK_GE(size_in_bytes, kHeaderSize);
return size_in_bytes - kHeaderSize;
}
// Returns data start address.
inline byte* GetDataStartAddress();
// Returns address of the past-the-end element.
inline byte* GetDataEndAddress();
inline int DataSize() const;
// Returns a pointer to the ByteArray object for a given data start address.
static inline ByteArray FromDataStartAddress(Address address);
// Dispatched behavior.
inline int ByteArraySize();
DECL_PRINTER(ByteArray)
// Layout description.
static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
// Maximal length of a single ByteArray.
static const int kMaxLength = kMaxSize - kHeaderSize;
static_assert(Internals::IsValidSmi(kMaxLength),
"ByteArray maxLength not a Smi");
class BodyDescriptor;
protected:
TQ_OBJECT_CONSTRUCTORS(ByteArray)
inline ByteArray(Address ptr, HeapObject::AllowInlineSmiStorage allow_smi);
};
// Wrapper class for ByteArray which can store arbitrary C++ classes, as long
// as they can be copied with memcpy.
template <class T>
class PodArray : public ByteArray {
public:
static Handle<PodArray<T>> New(
Isolate* isolate, int length,
AllocationType allocation = AllocationType::kYoung);
void copy_out(int index, T* result, int length) {
ByteArray::copy_out(index * sizeof(T), reinterpret_cast<byte*>(result),
length * sizeof(T));
}
void copy_in(int index, const T* buffer, int length) {
ByteArray::copy_in(index * sizeof(T), reinterpret_cast<const byte*>(buffer),
length * sizeof(T));
}
bool matches(const T* buffer, int length) {
DCHECK_LE(length, this->length());
return memcmp(GetDataStartAddress(), buffer, length * sizeof(T)) == 0;
}
T get(int index) {
T result;
copy_out(index, &result, 1);
return result;
}
void set(int index, const T& value) { copy_in(index, &value, 1); }
inline int length() const;
DECL_CAST(PodArray<T>)
OBJECT_CONSTRUCTORS(PodArray<T>, ByteArray);
};
class TemplateList
: public TorqueGeneratedTemplateList<TemplateList, FixedArray> {
public:
static Handle<TemplateList> New(Isolate* isolate, int size);
inline int length() const;
inline Object get(int index) const;
inline Object get(IsolateRoot isolate, int index) const;
inline void set(int index, Object value);
static Handle<TemplateList> Add(Isolate* isolate, Handle<TemplateList> list,
Handle<Object> value);
private:
static const int kLengthIndex = 0;
static const int kFirstElementIndex = kLengthIndex + 1;
TQ_OBJECT_CONSTRUCTORS(TemplateList)
};
} // namespace internal
} // namespace v8
#include "src/objects/object-macros-undef.h"
#endif // V8_OBJECTS_FIXED_ARRAY_H_