process: use owner_symbol for _getActive*

This makes it easier to provide public APIs in the return types
of `process._getActiveHandles()` and `process._getActiveRequests()`.

PR-URL: #22002
Backport-PR-URL: #22507
Reviewed-By: Michaël Zasso <targos@protonmail.com>

Author: addaleax

src/async_wrap.cc

@@ -736,6 +736,27 @@ std::string AsyncWrap::diagnostic_name() const {
       std::to_string(static_cast<int64_t>(async_id_)) + ")";
 }
 
+Local<Object> AsyncWrap::GetOwner() {
+  return GetOwner(env(), object());
+}
+
+Local<Object> AsyncWrap::GetOwner(Environment* env, Local<Object> obj) {
+  v8::EscapableHandleScope handle_scope(env->isolate());
+  CHECK(!obj.IsEmpty());
+
+  v8::TryCatch ignore_exceptions(env->isolate());
+  while (true) {
+    Local<Value> owner;
+    if (!obj->Get(env->context(),
+                  env->owner_symbol()).ToLocal(&owner) ||
+        !owner->IsObject()) {
+      return handle_scope.Escape(obj);
+    }
+
+    obj = owner.As<Object>();
+  }
+}
+
 }  // namespace node
 
 NODE_BUILTIN_MODULE_CONTEXT_AWARE(async_wrap, node::AsyncWrap::Initialize)

src/async_wrap.h

@@ -179,6 +179,12 @@ class AsyncWrap : public BaseObject {
 
   static void WeakCallback(const v8::WeakCallbackInfo<DestroyParam> &info);
 
+  // Returns the object that 'owns' an async wrap. For example, for a
+  // TCP connection handle, this is the corresponding net.Socket.
+  v8::Local<v8::Object> GetOwner();
+  static v8::Local<v8::Object> GetOwner(Environment* env,
+                                        v8::Local<v8::Object> obj);
+
   // This is a simplified version of InternalCallbackScope that only runs
   // the `before` and `after` hooks. Only use it when not actually calling
   // back into JS; otherwise, use InternalCallbackScope.

src/node.cc

@@ -1143,7 +1143,7 @@ static void GetActiveRequests(const FunctionCallbackInfo<Value>& args) {
   for (auto w : *env->req_wrap_queue()) {
     if (w->persistent().IsEmpty())
       continue;
-    argv[idx] = w->object();
+    argv[idx] = w->GetOwner();
     if (++idx >= arraysize(argv)) {
       fn->Call(ctx, ary, idx, argv).ToLocalChecked();
       idx = 0;
@@ -1169,16 +1169,10 @@ void GetActiveHandles(const FunctionCallbackInfo<Value>& args) {
   Local<Value> argv[NODE_PUSH_VAL_TO_ARRAY_MAX];
   size_t idx = 0;
 
-  Local<String> owner_sym = env->owner_string();
-
   for (auto w : *env->handle_wrap_queue()) {
-    if (w->persistent().IsEmpty() || !HandleWrap::HasRef(w))
+    if (!HandleWrap::HasRef(w))
       continue;
-    Local<Object> object = w->object();
-    Local<Value> owner = object->Get(owner_sym);
-    if (owner->IsUndefined())
-      owner = object;
-    argv[idx] = owner;
+    argv[idx] = w->GetOwner();
     if (++idx >= arraysize(argv)) {
       fn->Call(ctx, ary, idx, argv).ToLocalChecked();
       idx = 0;