deps/v8/test/mjsunit/harmony/weakrefs/stress-finalizationregistry-dirty-enqueue.js


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// Copyright 2020 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.

// Flags: --stress-compaction --expose-gc

// Test that the dirty FinalizationRegistries that are enqueued during GC have
// their slots correctly recorded by the GC.

// 1) Create many JSFinalizationRegistry objects so that they span several pages
// (page size is 256kb).
let registries = [];
for (let i = 0; i < 1024 * 8; i++) {
  registries.push(new FinalizationRegistry(() => {}));
}

// 2) Force two GCs to ensure that JSFinalizatonRegistry objects are tenured.
gc();
gc();

// 3) In a function: create a dummy target and register it in all
// JSFinalizatonRegistry objects.
(function() {
  let garbage = {};
  registries.forEach((fr) => {
    fr.register(garbage, 42);
  });
  garbage = null;
})();

// 4) Outside the function where the target is unreachable: force GC to collect
// the object.
gc();

// 5) Force another GC to test that the slot was correctly updated.
gc();