JSTests/stress/v8-unregister-after-cleanup.js

// Copyright 2018 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: --harmony-weak-refs --expose-gc --noincremental-marking

load("./resources/v8-mjsunit.js", "caller relative");

let cleanup_call_count = 0;
let cleanup = function(holdings) {
  assertEquals("holdings", holdings);
  ++cleanup_call_count;
}

let fg = new FinalizationRegistry(cleanup);
let key = {"k": "this is the key"};
// Create an object and register it in the FinalizationRegistry. The object needs
// to be inside a closure so that we can reliably kill them!

(function() {
    for (let i = 0; i < 1000; ++i) {
        let object = {};
        fg.register(object, "holdings", key);
    }
})();

// This GC will reclaim the target object and schedule cleanup.
gc();
assertEquals(0, cleanup_call_count);

// Assert that the cleanup function was called.
let timeout_func = function() {
    assertNotEquals(0, cleanup_call_count);
    let old_cleanup_call_count = cleanup_call_count;

    // Unregister an already cleaned-up weak reference.
    let success = fg.unregister(key);
    // Since we may not collect everything we don't know what success will be unlike v8.
    // assertFalse(success);

    // Assert that it didn't do anything.
    setTimeout(() => { assertEquals(old_cleanup_call_count, cleanup_call_count); }, 0);
}

setTimeout(timeout_func, 0);