chromium/v8/src/objects/backing-store.h

// Copyright 2019 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_BACKING_STORE_H_
#define V8_OBJECTS_BACKING_STORE_H_

#include <memory>
#include <optional>

#include "include/v8-array-buffer.h"
#include "include/v8-internal.h"
#include "src/handles/handles.h"

namespace v8::internal {

class Isolate;
class WasmMemoryObject;

// Whether this is Wasm memory, and if 32 or 64 bit.
enum class WasmMemoryFlag : uint8_t { … };

// Whether the backing store is shared or not.
enum class SharedFlag : uint8_t { … };

// Whether the backing store is resizable or not.
enum class ResizableFlag : uint8_t { … };

// Whether the backing store memory is initialied to zero or not.
enum class InitializedFlag : uint8_t { … };

// Internal information for shared wasm memories. E.g. contains
// a list of all memory objects (across all isolates) that share this
// backing store.
struct SharedWasmMemoryData;

// The {BackingStore} data structure stores all the low-level details about the
// backing store of an array buffer or Wasm memory, including its base address
// and length, whether it is shared, provided by the embedder, has guard
// regions, etc. Instances of this classes *own* the underlying memory
// when they are created through one of the {Allocate()} methods below,
// and the destructor frees the memory (and page allocation if necessary).
class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase { … };

// A global, per-process mapping from buffer addresses to backing stores
// of wasm memory objects.
class GlobalBackingStoreRegistry { … };

}  // namespace v8::internal

#endif  // V8_OBJECTS_BACKING_STORE_H_