WIP SharedArrayBuffer implementation

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index bca6bf1b6fd1c99f762ec307452661e0477d2300..694d7c4aea9c28574489173b093ec05bb0215118 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -1893,6 +1893,73 @@ class V8_EXPORT Value : public Data {
    */
   bool IsDataView() const;
 
+  /**
+   * Returns true if this value is a SharedArrayBuffer.
+   * This is an experimental feature.
+   */
+  bool IsSharedArrayBuffer() const;
+
+  /**
+   * Returns true if this value is one of SharedTypedArrays.
+   * This is an experimental feature.
+   */
+  bool IsSharedTypedArray() const;
+
+  /**
+   * Returns true if this value is a SharedUint8Array.
+   * This is an experimental feature.
+   */
+  bool IsSharedUint8Array() const;
+
+  /**
+   * Returns true if this value is a SharedUint8ClampedArray.
+   * This is an experimental feature.
+   */
+  bool IsSharedUint8ClampedArray() const;
+
+  /**
+   * Returns true if this value is a SharedInt8Array.
+   * This is an experimental feature.
+   */
+  bool IsSharedInt8Array() const;
+
+  /**
+   * Returns true if this value is a SharedUint16Array.
+   * This is an experimental feature.
+   */
+  bool IsSharedUint16Array() const;
+
+  /**
+   * Returns true if this value is a SharedInt16Array.
+   * This is an experimental feature.
+   */
+  bool IsSharedInt16Array() const;
+
+  /**
+   * Returns true if this value is a SharedUint32Array.
+   * This is an experimental feature.
+   */
+  bool IsSharedUint32Array() const;
+
+  /**
+   * Returns true if this value is a SharedInt32Array.
+   * This is an experimental feature.
+   */
+  bool IsSharedInt32Array() const;
+
+  /**
+   * Returns true if this value is a SharedFloat32Array.
+   * This is an experimental feature.
+   */
+  bool IsSharedFloat32Array() const;
+
+  /**
+   * Returns true if this value is a SharedFloat64Array.
+   * This is an experimental feature.
+   */
+  bool IsSharedFloat64Array() const;
+
+
   V8_WARN_UNUSED_RESULT MaybeLocal<Boolean> ToBoolean(
       Local<Context> context) const;
   V8_WARN_UNUSED_RESULT MaybeLocal<Number> ToNumber(
@@ -3599,6 +3666,307 @@ class V8_EXPORT DataView : public ArrayBufferView {
 
 
 /**
+ * TODO(binji): document
+ * An instance of the built-in SharedArrayBuffer constructor (ES6 draft
+ * 15.13.5).
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedArrayBuffer : public Object {
+ public:
+  /**
+   * Allocator that V8 uses to allocate |SharedArrayBuffer|'s memory.  The
+   * allocator is a global V8 setting. It should be set with
+   * V8::SetSharedArrayBufferAllocator prior to creation of a first
+   * SharedArrayBuffer.
+   *
+   * This API is experimental and may change significantly.
+   */
+  class V8_EXPORT Allocator {  // NOLINT

[jochen (gone - plz use gerrit), 2015/04/28 18:31:46]

why can't we use the allocator form ArrayBuffer?

[binji, 2015/04/29 18:27:22]

Done.

+   public:
+    virtual ~Allocator() {}
+
+    /**
+     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Memory should be initialized to zeroes.
+     */
+    virtual void* Allocate(size_t length) = 0;
+
+    /**
+     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Memory does not have to be initialized.
+     */
+    virtual void* AllocateUninitialized(size_t length) = 0;
+    /**
+     * Free the memory block of size |length|, pointed to by |data|.
+     * That memory is guaranteed to be previously allocated by |Allocate|.
+     */
+    virtual void Free(void* data, size_t length) = 0;
+  };
+
+  /**
+   * The contents of an |SharedArrayBuffer|. Externalization of
+   * |SharedArrayBuffer| returns an instance of this class, populated, with a
+   * pointer to data and byte length.
+   *
+   * The Data pointer of SharedArrayBuffer::Contents is always allocated with
+   * Allocator::Allocate that is set with V8::SetSharedArrayBufferAllocator.
+   *
+   * This API is experimental and may change significantly.
+   */
+  class V8_EXPORT Contents {  // NOLINT
+   public:
+    Contents() : data_(NULL), byte_length_(0) {}
+
+    void* Data() const { return data_; }
+    size_t ByteLength() const { return byte_length_; }
+
+   private:
+    void* data_;
+    size_t byte_length_;
+
+    friend class SharedArrayBuffer;
+  };
+
+
+  /**
+   * Data length in bytes.
+   */
+  size_t ByteLength() const;
+
+  /**
+   * Create a new SharedArrayBuffer. Allocate |byte_length| bytes.
+   * Allocated memory will be owned by a created SharedArrayBuffer and
+   * will be deallocated when it is garbage-collected,
+   * unless the object is externalized.
+   */
+  static Local<SharedArrayBuffer> New(Isolate* isolate, size_t byte_length);
+
+  /**
+   * Create a new SharedArrayBuffer over an existing memory block.
+   * The created array buffer is immediately in externalized state.
+   * The memory block will not be reclaimed when a created SharedArrayBuffer
+   * is garbage-collected.
+   */
+  static Local<SharedArrayBuffer> New(Isolate* isolate, void* data,
+                                      size_t byte_length);

[jochen (gone - plz use gerrit), 2015/04/28 18:31:46]

we should have a version that creates an internalized shared array buffer

[binji, 2015/04/29 18:27:22]

Done.

+
+  /**
+   * Returns true if SharedArrayBuffer is extrenalized, that is, does not
+   * own its memory block.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Make this SharedArrayBuffer external. The pointer to underlying memory
+   * block and byte length are returned as |Contents| structure. After
+   * SharedArrayBuffer had been etxrenalized, it does no longer owns the memory
+   * block. The caller should take steps to free memory when it is no longer
+   * needed.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * that has been set with V8::SetSharedArrayBufferAllocator.
+   */
+  Contents Externalize();

[jochen (gone - plz use gerrit), 2015/04/28 18:31:46]

also add GetContents() that gets the contents without externalizing

[binji, 2015/04/29 18:27:22]

Done.

+
+  V8_INLINE static SharedArrayBuffer* Cast(Value* obj);
+
+  static const int kInternalFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+
+ private:
+  SharedArrayBuffer();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * TODO(binji): document
+ * A base class for an instance of TypedArray series of constructors
+ * (ES6 draft 15.13.6).
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedTypedArray : public Object {
+ public:
+  /**
+   * Returns underlying SharedArrayBuffer.
+   */
+  Local<SharedArrayBuffer> Buffer();
+  /**
+   * Byte offset in |Buffer|.
+   */
+  size_t ByteOffset();
+  /**
+   * Size of a view in bytes.
+   */
+  size_t ByteLength();
+
+  /**
+   * Number of elements in this typed array
+   * (e.g. for SharedInt16Array, |ByteLength|/2).
+   */
+  size_t Length();
+
+  V8_INLINE static SharedTypedArray* Cast(Value* obj);
+
+ private:
+  SharedTypedArray();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * TODO(binji): document
+ * An instance of Uint8Array constructor (ES6 draft 15.13.6).
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedUint8Array : public SharedTypedArray {
+ public:
+  static Local<SharedUint8Array> New(Handle<SharedArrayBuffer> array_buffer,
+                                     size_t byte_offset, size_t length);
+  V8_INLINE static SharedUint8Array* Cast(Value* obj);
+
+ private:
+  SharedUint8Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * TODO(binji): document
+ * An instance of Uint8ClampedArray constructor (ES6 draft 15.13.6).
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedUint8ClampedArray : public SharedTypedArray {
+ public:
+  static Local<SharedUint8ClampedArray> New(
+      Handle<SharedArrayBuffer> array_buffer, size_t byte_offset,
+      size_t length);
+  V8_INLINE static SharedUint8ClampedArray* Cast(Value* obj);
+
+ private:
+  SharedUint8ClampedArray();
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * TODO(binji): document
+ * An instance of Int8Array constructor (ES6 draft 15.13.6).
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedInt8Array : public SharedTypedArray {
+ public:
+  static Local<SharedInt8Array> New(Handle<SharedArrayBuffer> array_buffer,
+                                    size_t byte_offset, size_t length);
+  V8_INLINE static SharedInt8Array* Cast(Value* obj);
+
+ private:
+  SharedInt8Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * TODO(binji): document
+ * An instance of Uint16Array constructor (ES6 draft 15.13.6).
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedUint16Array : public SharedTypedArray {
+ public:
+  static Local<SharedUint16Array> New(Handle<SharedArrayBuffer> array_buffer,
+                                      size_t byte_offset, size_t length);
+  V8_INLINE static SharedUint16Array* Cast(Value* obj);
+
+ private:
+  SharedUint16Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * TODO(binji): document
+ * An instance of Int16Array constructor (ES6 draft 15.13.6).
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedInt16Array : public SharedTypedArray {
+ public:
+  static Local<SharedInt16Array> New(Handle<SharedArrayBuffer> array_buffer,
+                                     size_t byte_offset, size_t length);
+  V8_INLINE static SharedInt16Array* Cast(Value* obj);
+
+ private:
+  SharedInt16Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * TODO(binji): document
+ * An instance of Uint32Array constructor (ES6 draft 15.13.6).
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedUint32Array : public SharedTypedArray {
+ public:
+  static Local<SharedUint32Array> New(Handle<SharedArrayBuffer> array_buffer,
+                                      size_t byte_offset, size_t length);
+  V8_INLINE static SharedUint32Array* Cast(Value* obj);
+
+ private:
+  SharedUint32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * TODO(binji): document
+ * An instance of Int32Array constructor (ES6 draft 15.13.6).
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedInt32Array : public SharedTypedArray {
+ public:
+  static Local<SharedInt32Array> New(Handle<SharedArrayBuffer> array_buffer,
+                                     size_t byte_offset, size_t length);
+  V8_INLINE static SharedInt32Array* Cast(Value* obj);
+
+ private:
+  SharedInt32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * TODO(binji): document
+ * An instance of Float32Array constructor (ES6 draft 15.13.6).
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedFloat32Array : public SharedTypedArray {
+ public:
+  static Local<SharedFloat32Array> New(Handle<SharedArrayBuffer> array_buffer,
+                                       size_t byte_offset, size_t length);
+  V8_INLINE static SharedFloat32Array* Cast(Value* obj);
+
+ private:
+  SharedFloat32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * TODO(binji): document
+ * An instance of Float64Array constructor (ES6 draft 15.13.6).
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedFloat64Array : public SharedTypedArray {
+ public:
+  static Local<SharedFloat64Array> New(Handle<SharedArrayBuffer> array_buffer,
+                                       size_t byte_offset, size_t length);
+  V8_INLINE static SharedFloat64Array* Cast(Value* obj);
+
+ private:
+  SharedFloat64Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
  * An instance of the built-in Date constructor (ECMA-262, 15.9).
  */
 class V8_EXPORT Date : public Object {
@@ -5705,6 +6073,15 @@ class V8_EXPORT V8 {
   static void SetArrayBufferAllocator(ArrayBuffer::Allocator* allocator);
 
   /**
+   * Set allocator to use for SharedArrayBuffer memory.
+   * The allocator should be set only once. The allocator should be set
+   * before any code tha uses SharedArrayBuffers is executed.
+   * This allocator is used in all isolates.
+   */
+  static void SetSharedArrayBufferAllocator(

[jochen (gone - plz use gerrit), 2015/04/28 18:31:46]

the allocator should be per isolate and passed in via CreateParams. I'll change
the array buffer one soon to follow this pattern.

[binji, 2015/04/29 18:27:22]

Done.

+      SharedArrayBuffer::Allocator* allocator);
+
+  /**
   * Check if V8 is dead and therefore unusable.  This is the case after
   * fatal errors such as out-of-memory situations.
   */
@@ -6657,7 +7034,7 @@ class Internals {
   static const int kJSObjectHeaderSize = 3 * kApiPointerSize;
   static const int kFixedArrayHeaderSize = 2 * kApiPointerSize;
   static const int kContextHeaderSize = 2 * kApiPointerSize;
-  static const int kContextEmbedderDataIndex = 76;
+  static const int kContextEmbedderDataIndex = 95;
   static const int kFullStringRepresentationMask = 0x07;
   static const int kStringEncodingMask = 0x4;
   static const int kExternalTwoByteRepresentationTag = 0x02;
@@ -7708,6 +8085,94 @@ DataView* DataView::Cast(v8::Value* value) {
 }
 
 
+SharedArrayBuffer* SharedArrayBuffer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedArrayBuffer*>(value);
+}
+
+
+SharedTypedArray* SharedTypedArray::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedTypedArray*>(value);
+}
+
+
+SharedUint8Array* SharedUint8Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedUint8Array*>(value);
+}
+
+
+SharedInt8Array* SharedInt8Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedInt8Array*>(value);
+}
+
+
+SharedUint16Array* SharedUint16Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedUint16Array*>(value);
+}
+
+
+SharedInt16Array* SharedInt16Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedInt16Array*>(value);
+}
+
+
+SharedUint32Array* SharedUint32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedUint32Array*>(value);
+}
+
+
+SharedInt32Array* SharedInt32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedInt32Array*>(value);
+}
+
+
+SharedFloat32Array* SharedFloat32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedFloat32Array*>(value);
+}
+
+
+SharedFloat64Array* SharedFloat64Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedFloat64Array*>(value);
+}
+
+
+SharedUint8ClampedArray* SharedUint8ClampedArray::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedUint8ClampedArray*>(value);
+}
+
+
 Function* Function::Cast(v8::Value* value) {
 #ifdef V8_ENABLE_CHECKS
   CheckCast(value);