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// Copyright 2018 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_JS_ARRAY_BUFFER_H_
#define V8_OBJECTS_JS_ARRAY_BUFFER_H_
#include "src/objects.h"
// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"
namespace v8 {
namespace internal {
// Whether a JSArrayBuffer is a SharedArrayBuffer or not.
enum class SharedFlag { kNotShared, kShared };
class JSArrayBuffer : public JSObject {
public:
// [byte_length]: length in bytes
DECL_ACCESSORS(byte_length, Object)
// [backing_store]: backing memory for this array
DECL_ACCESSORS(backing_store, void)
// For non-wasm, allocation_length and allocation_base are byte_length and
// backing_store, respectively.
inline size_t allocation_length() const;
inline void* allocation_base() const;
inline uint32_t bit_field() const;
inline void set_bit_field(uint32_t bits);
// [is_external]: true indicates that the embedder is in charge of freeing the
// backing_store, while is_external == false means that v8 will free the
// memory block once all ArrayBuffers referencing it are collected by the GC.
inline bool is_external();
inline void set_is_external(bool value);
inline bool is_neuterable();
inline void set_is_neuterable(bool value);
inline bool was_neutered();
inline void set_was_neutered(bool value);
inline bool is_shared();
inline void set_is_shared(bool value);
inline bool is_growable();
inline void set_is_growable(bool value);
DECL_CAST(JSArrayBuffer)
void Neuter();
struct Allocation {
Allocation(void* allocation_base, size_t length, void* backing_store,
bool is_wasm_memory)
: allocation_base(allocation_base),
length(length),
backing_store(backing_store),
is_wasm_memory(is_wasm_memory) {}
void* allocation_base;
size_t length;
void* backing_store;
bool is_wasm_memory;
};
// Returns whether the buffer is tracked by the WasmMemoryTracker.
inline bool is_wasm_memory() const;
// Sets whether the buffer is tracked by the WasmMemoryTracker.
void set_is_wasm_memory(bool is_wasm_memory);
// Removes the backing store from the WasmMemoryTracker and sets
// |is_wasm_memory| to false.
void StopTrackingWasmMemory(Isolate* isolate);
void FreeBackingStoreFromMainThread();
static void FreeBackingStore(Isolate* isolate, Allocation allocation);
V8_EXPORT_PRIVATE static void Setup(
Handle<JSArrayBuffer> array_buffer, Isolate* isolate, bool is_external,
void* data, size_t allocated_length,
SharedFlag shared = SharedFlag::kNotShared, bool is_wasm_memory = false);
// Returns false if array buffer contents could not be allocated.
// In this case, |array_buffer| will not be set up.
static bool SetupAllocatingData(
Handle<JSArrayBuffer> array_buffer, Isolate* isolate,
size_t allocated_length, bool initialize = true,
SharedFlag shared = SharedFlag::kNotShared) V8_WARN_UNUSED_RESULT;
// Dispatched behavior.
DECL_PRINTER(JSArrayBuffer)
DECL_VERIFIER(JSArrayBuffer)
static const int kByteLengthOffset = JSObject::kHeaderSize;
// The rest of the fields are not JSObjects, so they are not iterated over in
// objects-body-descriptors-inl.h.
static const int kBackingStoreOffset = kByteLengthOffset + kPointerSize;
static const int kBitFieldSlot = kBackingStoreOffset + kPointerSize;
#if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
static const int kBitFieldOffset = kBitFieldSlot;
#else
static const int kBitFieldOffset = kBitFieldSlot + kInt32Size;
#endif
static const int kSize = kBitFieldSlot + kPointerSize;
static const int kSizeWithEmbedderFields =
kSize + v8::ArrayBuffer::kEmbedderFieldCount * kPointerSize;
// Iterates all fields in the object including internal ones except
// kBackingStoreOffset and kBitFieldSlot.
class BodyDescriptor;
// No weak fields.
typedef BodyDescriptor BodyDescriptorWeak;
class IsExternal : public BitField<bool, 1, 1> {};
class IsNeuterable : public BitField<bool, 2, 1> {};
class WasNeutered : public BitField<bool, 3, 1> {};
class IsShared : public BitField<bool, 4, 1> {};
class IsGrowable : public BitField<bool, 5, 1> {};
class IsWasmMemory : public BitField<bool, 6, 1> {};
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBuffer);
};
class JSArrayBufferView : public JSObject {
public:
// [buffer]: ArrayBuffer that this typed array views.
DECL_ACCESSORS(buffer, Object)
// [byte_offset]: offset of typed array in bytes.
DECL_ACCESSORS(byte_offset, Object)
// [byte_length]: length of typed array in bytes.
DECL_ACCESSORS(byte_length, Object)
DECL_CAST(JSArrayBufferView)
DECL_VERIFIER(JSArrayBufferView)
inline bool WasNeutered() const;
static const int kBufferOffset = JSObject::kHeaderSize;
static const int kByteOffsetOffset = kBufferOffset + kPointerSize;
static const int kByteLengthOffset = kByteOffsetOffset + kPointerSize;
static const int kViewSize = kByteLengthOffset + kPointerSize;
private:
#ifdef VERIFY_HEAP
DECL_ACCESSORS(raw_byte_offset, Object)
DECL_ACCESSORS(raw_byte_length, Object)
#endif
DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBufferView);
};
class JSTypedArray : public JSArrayBufferView {
public:
// [length]: length of typed array in elements.
DECL_ACCESSORS(length, Object)
inline size_t length_value() const;
// ES6 9.4.5.3
V8_WARN_UNUSED_RESULT static Maybe<bool> DefineOwnProperty(
Isolate* isolate, Handle<JSTypedArray> o, Handle<Object> key,
PropertyDescriptor* desc, ShouldThrow should_throw);
DECL_CAST(JSTypedArray)
ExternalArrayType type();
V8_EXPORT_PRIVATE size_t element_size();
Handle<JSArrayBuffer> GetBuffer();
// Whether the buffer's backing store is on-heap or off-heap.
inline bool is_on_heap() const;
static inline MaybeHandle<JSTypedArray> Validate(Isolate* isolate,
Handle<Object> receiver,
const char* method_name);
// Dispatched behavior.
DECL_PRINTER(JSTypedArray)
DECL_VERIFIER(JSTypedArray)
static const int kLengthOffset = kViewSize;
static const int kSize = kLengthOffset + kPointerSize;
static const int kSizeWithEmbedderFields =
kSize + v8::ArrayBufferView::kEmbedderFieldCount * kPointerSize;
private:
static Handle<JSArrayBuffer> MaterializeArrayBuffer(
Handle<JSTypedArray> typed_array);
#ifdef VERIFY_HEAP
DECL_ACCESSORS(raw_length, Object)
#endif
DISALLOW_IMPLICIT_CONSTRUCTORS(JSTypedArray);
};
class JSDataView : public JSArrayBufferView {
public:
DECL_CAST(JSDataView)
// Dispatched behavior.
DECL_PRINTER(JSDataView)
DECL_VERIFIER(JSDataView)
static const int kSize = kViewSize;
static const int kSizeWithEmbedderFields =
kSize + v8::ArrayBufferView::kEmbedderFieldCount * kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataView);
};
} // namespace internal
} // namespace v8
#include "src/objects/object-macros-undef.h"
#endif // V8_OBJECTS_JS_ARRAY_BUFFER_H_
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