v8/test/mjsunit/harmony/weakrefs/weak-cell-basics.js
Shu-yu Guo f902b9dd8d [weakrefs] Update FinalizationRegistry to take a per-item callback
Bug: v8:8179
Change-Id: I0cd43db6558db616690de2dd012bf7518c49345d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2138563
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67069}
2020-04-08 17:54:24 +00:00

40 lines
1.1 KiB
JavaScript

// 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
let cleanup_called = false;
let cleanup = function(holdings_arg) {
assertFalse(cleanup_called);
assertEquals(holdings_arg, holdings);
cleanup_called = true;
}
let fg = new FinalizationRegistry(cleanup);
let o = {};
let holdings = {'h': 55};
// Ignition holds references to objects in temporary registers. These will be
// released when the function exits. So only access o inside a function to
// prevent any references to objects in temporary registers when a gc is
// triggered.
(() => { fg.register(o, holdings); })()
gc();
assertFalse(cleanup_called);
// Drop the last reference to o.
(() => { o = null; })()
// GC will clear the WeakCell; the cleanup function will be called the next time
// we enter the event loop.
gc();
assertFalse(cleanup_called);
let timeout_func = function() {
assertTrue(cleanup_called);
}
setTimeout(timeout_func, 0);