Implement SharedArrayBuffer

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 125a31be06f94b802e9f61a465335ee641b8c189..8adf2693f127a26a5897dfc1cdaffc3b0bba8551 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -341,6 +341,7 @@ StartupData V8::CreateSnapshotDataBlob(const char* custom_source) {
   i::Isolate* internal_isolate = new i::Isolate(true);
   ArrayBufferAllocator allocator;
   internal_isolate->set_array_buffer_allocator(&allocator);
+  internal_isolate->set_shared_array_buffer_allocator(&allocator);
   Isolate* isolate = reinterpret_cast<Isolate*>(internal_isolate);
   StartupData result = {NULL, 0};
   {
@@ -2677,7 +2678,8 @@ bool Value::IsArray() const {
 
 
 bool Value::IsArrayBuffer() const {
-  return Utils::OpenHandle(this)->IsJSArrayBuffer();
+  i::Handle<i::Object> obj = Utils::OpenHandle(this);
+  return obj->IsJSArrayBuffer() && !i::JSArrayBuffer::cast(*obj)->is_shared();
 }
 
 
@@ -2698,6 +2700,7 @@ bool Value::IsTypedArray() const {
            i::JSTypedArray::cast(*obj)->type() == i::kExternal##Type##Array; \
   }
 
+
 TYPED_ARRAYS(VALUE_IS_TYPED_ARRAY)
 
 #undef VALUE_IS_TYPED_ARRAY
@@ -2708,6 +2711,12 @@ bool Value::IsDataView() const {
 }
 
 
+bool Value::IsSharedArrayBuffer() const {
+  i::Handle<i::Object> obj = Utils::OpenHandle(this);
+  return obj->IsJSArrayBuffer() && i::JSArrayBuffer::cast(*obj)->is_shared();
+}
+
+
 bool Value::IsObject() const {
   return Utils::OpenHandle(this)->IsJSObject();
 }
@@ -3084,9 +3093,9 @@ void v8::Promise::Resolver::CheckCast(Value* that) {
 
 void v8::ArrayBuffer::CheckCast(Value* that) {
   i::Handle<i::Object> obj = Utils::OpenHandle(that);
-  Utils::ApiCheck(obj->IsJSArrayBuffer(),
-                  "v8::ArrayBuffer::Cast()",
-                  "Could not convert to ArrayBuffer");
+  Utils::ApiCheck(
+      obj->IsJSArrayBuffer() && !i::JSArrayBuffer::cast(*obj)->is_shared(),
+      "v8::ArrayBuffer::Cast()", "Could not convert to ArrayBuffer");
 }
 
 
@@ -3129,6 +3138,15 @@ void v8::DataView::CheckCast(Value* that) {
 }
 
 
+void v8::SharedArrayBuffer::CheckCast(Value* that) {
+  i::Handle<i::Object> obj = Utils::OpenHandle(that);
+  Utils::ApiCheck(
+      obj->IsJSArrayBuffer() && i::JSArrayBuffer::cast(*obj)->is_shared(),
+      "v8::SharedArrayBuffer::Cast()",
+      "Could not convert to SharedArrayBuffer");
+}
+
+
 void v8::Date::CheckCast(v8::Value* that) {
   i::Handle<i::Object> obj = Utils::OpenHandle(that);
   i::Isolate* isolate = NULL;
@@ -6303,7 +6321,7 @@ Local<ArrayBuffer> v8::ArrayBuffer::New(Isolate* isolate, size_t byte_length) {
   LOG_API(i_isolate, "v8::ArrayBuffer::New(size_t)");
   ENTER_V8(i_isolate);
   i::Handle<i::JSArrayBuffer> obj =
-      i_isolate->factory()->NewJSArrayBuffer();
+      i_isolate->factory()->NewJSArrayBuffer(i::NOT_SHARED);
   i::Runtime::SetupArrayBufferAllocatingData(i_isolate, obj, byte_length);
   return Utils::ToLocal(obj);
 }
@@ -6316,7 +6334,7 @@ Local<ArrayBuffer> v8::ArrayBuffer::New(Isolate* isolate, void* data,
   LOG_API(i_isolate, "v8::ArrayBuffer::New(void*, size_t)");
   ENTER_V8(i_isolate);
   i::Handle<i::JSArrayBuffer> obj =
-      i_isolate->factory()->NewJSArrayBuffer();
+      i_isolate->factory()->NewJSArrayBuffer(i::NOT_SHARED);
   i::Runtime::SetupArrayBuffer(i_isolate, obj,
                                mode == ArrayBufferCreationMode::kExternalized,
                                data, byte_length);
@@ -6422,6 +6440,66 @@ Local<DataView> DataView::New(Handle<ArrayBuffer> array_buffer,
 }
 
 
+bool v8::SharedArrayBuffer::IsExternal() const {
+  return Utils::OpenHandle(this)->is_external();
+}
+
+
+v8::SharedArrayBuffer::Contents v8::SharedArrayBuffer::Externalize() {
+  i::Handle<i::JSArrayBuffer> self = Utils::OpenHandle(this);
+  i::Isolate* isolate = self->GetIsolate();
+  Utils::ApiCheck(!self->is_external(), "v8::SharedArrayBuffer::Externalize",
+                  "SharedArrayBuffer already externalized");
+  self->set_is_external(true);
+  isolate->heap()->UnregisterArrayBuffer(self->backing_store());
+  return GetContents();
+}
+
+
+v8::SharedArrayBuffer::Contents v8::SharedArrayBuffer::GetContents() {
+  i::Handle<i::JSArrayBuffer> self = Utils::OpenHandle(this);
+  size_t byte_length = static_cast<size_t>(self->byte_length()->Number());
+  Contents contents;
+  contents.data_ = self->backing_store();
+  contents.byte_length_ = byte_length;
+  return contents;
+}
+
+
+size_t v8::SharedArrayBuffer::ByteLength() const {
+  i::Handle<i::JSArrayBuffer> obj = Utils::OpenHandle(this);
+  return static_cast<size_t>(obj->byte_length()->Number());
+}
+
+
+Local<SharedArrayBuffer> v8::SharedArrayBuffer::New(Isolate* isolate,
+                                                    size_t byte_length) {
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  LOG_API(i_isolate, "v8::SharedArrayBuffer::New(size_t)");
+  ENTER_V8(i_isolate);
+  i::Handle<i::JSArrayBuffer> obj =
+      i_isolate->factory()->NewJSArrayBuffer(i::SHARED);
+  i::Runtime::SetupArrayBufferAllocatingData(i_isolate, obj, byte_length, true,
+                                             i::SHARED);
+  return Utils::ToLocalShared(obj);
+}
+
+
+Local<SharedArrayBuffer> v8::SharedArrayBuffer::New(
+    Isolate* isolate, void* data, size_t byte_length,
+    ArrayBufferCreationMode mode) {
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  LOG_API(i_isolate, "v8::SharedArrayBuffer::New(void*, size_t)");
+  ENTER_V8(i_isolate);
+  i::Handle<i::JSArrayBuffer> obj =
+      i_isolate->factory()->NewJSArrayBuffer(i::SHARED);
+  i::Runtime::SetupArrayBuffer(i_isolate, obj,
+                               mode == ArrayBufferCreationMode::kExternalized,
+                               data, byte_length, i::SHARED);
+  return Utils::ToLocalShared(obj);
+}
+
+
 Local<Symbol> v8::Symbol::New(Isolate* isolate, Local<String> name) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   LOG_API(i_isolate, "Symbol::New()");
@@ -6768,6 +6846,14 @@ Isolate* Isolate::New(const Isolate::CreateParams& params) {
   } else {
     isolate->set_array_buffer_allocator(i::V8::ArrayBufferAllocator());
   }
+  if (params.shared_array_buffer_allocator) {
+    isolate->set_shared_array_buffer_allocator(
+        params.shared_array_buffer_allocator);
+  } else {
+    // Default to using the same allocator as the array_buffer_allocator.
+    isolate->set_shared_array_buffer_allocator(
+        isolate->array_buffer_allocator());
+  }
   if (params.snapshot_blob != NULL) {
     isolate->set_snapshot_blob(params.snapshot_blob);
   } else {