Supporting circular references that can be garbage collected.

In JavaScript I can make two objects that reference each other and they'll still be GCed.

function makeObjectsThatReferenceEachOtherButLeakNoReferences() {
  const a = new Uint8Array(1024);
  const b = new Uint8Array(1024);
  a.other = b; // make them reference each other
  b.other = a;
}

makeObjectsThatReferenceEachOtherButLeakNoReferences();

In the code above, even though a circular reference was created, JavaScript will see there is no path from root and garbage collect the objects.

Is it possible to do the same in C++ Napi. If I make a class

class MyClass : public Napi::ObjectWrap<MyClass> {
  ...
  Napi::Reference<Napi::Object> storedObjectRef_;
};

And I manage to make 2 instanced of MyClass and set storedObjectRef_ so they point to each other, AFAICT these objects will never be garbage collected.

Is there a solution?

Note: I know I could add some function close or whatever to null out storedObjectRef_ but that's not really the question I'm asking. I'm trying to reproduce JS garbage collecting circular references.

One idea I guess, which appears to work, is I could add a JS property to MyClass. So instead of Napi::Reference<Napi::Object> storageObjectRef_ I'd use Get, Set as in

this->Value().Set("storageObjectRef", otherObject);

but unfortunately that's visible externally which I don't want. I could use a symbol but those are inspectable too. Though it might be better than nothing if there is no other solutions.

从 issue 中所示的 Napi::ObjectWrap 和 Napi::Reference 用法开始，然后调查 Node-API 如何处理相互引用对象的原生引用和垃圾回收。完成的标准是确定是否支持可回收的循环引用，并记录或提出所需的 API 级方案；该 issue 未指定源文件或测试。