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// 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: --expose-gc --noincremental-marking
let o1 = {};
let o2 = {};
let wr1;
let wr2;
(function() {
wr1 = new WeakRef(o1);
wr2 = new WeakRef(o2);
})();
// Since the WeakRefs were created during this turn, they're not cleared by GC.
// Here and below, we invoke GC synchronously and, with conservative stack
// scanning, there is a chance that the object is not reclaimed now. In any
// case, the WeakRef should not be cleared.
gc();
(function() {
assertNotEquals(undefined, wr1.deref());
assertNotEquals(undefined, wr2.deref());
})();
// New task
setTimeout(function() {
(function () { wr1.deref(); })();
o1 = null;
gc(); // deref makes sure we don't clean up wr1
(function () { assertNotEquals(undefined, wr1.deref()); })();
// New task
setTimeout(function() {
(function () { wr2.deref(); })();
o2 = null;
gc(); // deref makes sure we don't clean up wr2
(function () { assertNotEquals(undefined, wr2.deref()); })();
// New task
(async function () {
// Trigger GC again to make sure the two WeakRefs are cleared.
// We need to invoke GC asynchronously and wait for it to finish, so that
// it doesn't need to scan the stack. Otherwise, the objects may not be
// reclaimed because of conservative stack scanning and the test may not
// work as intended.
await gc({ type: 'major', execution: 'async' });
assertEquals(undefined, wr1.deref());
assertEquals(undefined, wr2.deref());
})();
}, 0);
}, 0);
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