lib: implement WeakReference on top of JS WeakRef

The C++ implementation can now be done entirely in JS using WeakRef.
Re-implement it in JS instead to simplify the code.
PR-URL: #49053
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

Author: joyeecheung

lib/diagnostics_channel.js

@@ -28,7 +28,7 @@ const {
 
 const{ triggerUncaughtException }=internalBinding('errors');
 
-const{ WeakReference }=internalBinding('util');
+const{ WeakReference }=require('internal/util');
 
 // Can't delete when weakref count reaches 0 as it could increment again.
 // Only GC can be used as a valid time to clean up the channels map.

lib/domain.js

@@ -52,9 +52,8 @@ const {
 const{ createHook }=require('async_hooks');
 const{ useDomainTrampoline }=require('internal/async_hooks');
 
-// TODO(addaleax): Use a non-internal solution for this.
 constkWeak=Symbol('kWeak');
-const{ WeakReference }=internalBinding('util');
+const{ WeakReference }=require('internal/util');
 
 // Overwrite process.domain with a getter/setter that will allow for more
 // effective optimizations

lib/internal/util.js

@@ -33,6 +33,7 @@ const {
  SafeMap,
  SafeSet,
  SafeWeakMap,
+ SafeWeakRef,
  StringPrototypeReplace,
  StringPrototypeToLowerCase,
  StringPrototypeToUpperCase,
@@ -797,6 +798,38 @@ function guessHandleType(fd) {
 returnhandleTypes[type];
 }
 
+classWeakReference{
+ #weak =null;
+ #strong =null;
+ #refCount =0;
+constructor(object){
+this.#weak =newSafeWeakRef(object);
+}
+
+incRef(){
+this.#refCount++;
+if(this.#refCount ===1){
+constderefed=this.#weak.deref();
+if(derefed!==undefined){
+this.#strong =derefed;
+}
+}
+returnthis.#refCount;
+}
+
+decRef(){
+this.#refCount--;
+if(this.#refCount ===0){
+this.#strong =null;
+}
+returnthis.#refCount;
+}
+
+get(){
+returnthis.#weak.deref();
+}
+}
+
 module.exports={
  getLazy,
  assertCrypto,
@@ -855,4 +888,5 @@ module.exports = {
  kEnumerableProperty,
  setOwnProperty,
  pendingDeprecate,
+ WeakReference,
 };

test/fixtures/snapshot/weak-reference-gc.js

@@ -1,7 +1,6 @@
 'use strict';
 
-const{ internalBinding }=require('internal/test/binding');
-const{ WeakReference }=internalBinding('util');
+const{ WeakReference }=require('internal/util');
 const{
  setDeserializeMainFunction
 }=require('v8').startupSnapshot

test/fixtures/snapshot/weak-reference.js

@@ -1,7 +1,6 @@
 'use strict';
 
-const{ internalBinding }=require('internal/test/binding');
-const{ WeakReference }=internalBinding('util');
+const{ WeakReference }=require('internal/util');
 const{
  setDeserializeMainFunction
 }=require('v8').startupSnapshot

test/parallel/test-internal-util-weakreference.js

@@ -2,8 +2,7 @@
 'use strict';
 constcommon=require('../common');
 constassert=require('assert');
-const{ internalBinding }=require('internal/test/binding');
-const{ WeakReference }=internalBinding('util');
+const{ WeakReference }=require('internal/util');
 
 letobj={hello: 'world'};
 constref=newWeakReference(obj);