[api] Prototype WeakRef implementation

src/runtime/runtime-collections.cc

 // Copyright 2014 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.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/conversions-inl.h"
 #include "src/factory.h"
 
@@ skipping 307 matching lines @@
 
 
 RUNTIME_FUNCTION(Runtime_GetWeakSetValues) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSWeakCollection, holder, 0);
   CONVERT_NUMBER_CHECKED(int, max_values, Int32, args[1]);
   CHECK(max_values >= 0);
   return *JSWeakCollection::GetEntries(holder, max_values);
 }
+
+RUNTIME_FUNCTION(Runtime_WeakRefInitialize) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(3, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(JSWeakRef, weak_ref, 0);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, target, 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, executor, 2);
+  CONVERT_ARG_HANDLE_CHECKED(Object, holdings, 3);
+  JSWeakRef::Initialize(weak_ref, isolate, target, executor, holdings);
+  return *weak_ref;
+}
+
+RUNTIME_FUNCTION(Runtime_WeakRefValue) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(JSWeakRef, weak_ref, 0);
+  Handle<Object> value = JSWeakRef::Value(weak_ref, isolate);
+  weak_ref->set_held(true);
+  return *value;
+}
+
+RUNTIME_FUNCTION(Runtime_WeakRefClear) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(JSWeakRef, weak_ref, 0);
+  JSWeakRef::Clear(weak_ref, isolate);
+  return isolate->heap()->undefined_value();
+}
 }  // namespace internal
 }  // namespace v8