[api] Prototype WeakRef implementation

src/factory.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/factory.h"
 
 #include "src/accessors.h"
 #include "src/allocation-site-scopes.h"
 #include "src/ast/ast.h"
 #include "src/base/bits.h"
@@ skipping 914 matching lines @@
   DCHECK(!map->is_prototype_map());
   Handle<JSObject> promise_obj = NewJSObjectFromMap(map);
   Handle<JSPromise> promise = Handle<JSPromise>::cast(promise_obj);
   promise->set_status(v8::Promise::kPending);
   promise->set_flags(0);
 
   isolate()->RunPromiseHook(PromiseHookType::kInit, promise, undefined_value());
   return promise;
 }
 
+void Factory::InitJSWeakRef(
+  Handle<JSWeakRef> weak_ref,
+  Handle<JSObject> target,
+  Handle<JSFunction> executor,
+  Handle<Object> holdings
+) {
+  Handle<JSFunction> constructor(
+      isolate()->native_context()->js_weak_ref_fun(), isolate());
+  DCHECK(constructor->has_initial_map());
+  Handle<Map> map(constructor->initial_map(), isolate());
+
+  DCHECK(!map->is_prototype_map());
+
+  weak_ref->set_target(*NewWeakCell(target));
+  weak_ref->set_executor(*executor);
+  weak_ref->set_holdings(*holdings);
+  weak_ref->set_held(false);
+  weak_ref->set_queued(false);
+
+  Handle<FixedArray> refs(isolate()->heap()->weak_refs(), isolate());
+  int num_refs = refs->length();
+  refs = isolate()->factory()->CopyFixedArrayAndGrow(refs, 1);
+  isolate()->heap()->set_weak_refs(*refs);
+  refs->set(num_refs, *weak_ref);
+}
+
 Handle<Context> Factory::NewNativeContext() {
   Handle<FixedArray> array =
       NewFixedArray(Context::NATIVE_CONTEXT_SLOTS, TENURED);
   array->set_map_no_write_barrier(*native_context_map());
   Handle<Context> context = Handle<Context>::cast(array);
   context->set_native_context(*context);
   context->set_errors_thrown(Smi::kZero);
   context->set_math_random_index(Smi::kZero);
   Handle<WeakCell> weak_cell = NewWeakCell(context);
   context->set_self_weak_cell(*weak_cell);
@@ skipping 1989 matching lines @@
     Handle<AccessorInfo> prototype =
         Accessors::FunctionPrototypeInfo(isolate(), rw_attribs);
     Descriptor d = Descriptor::AccessorConstant(
         Handle<Name>(Name::cast(prototype->name())), prototype, rw_attribs);
     map->AppendDescriptor(&d);
   }
 }
 
 }  // namespace internal
 }  // namespace v8