gecko/js/xpconnect/tests/unit/test_js_weak_references.js
2012-05-21 12:12:37 +01:00

46 lines
1.5 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* See https://bugzilla.mozilla.org/show_bug.cgi?id=317304 */
function run_test()
{
// Bug 712649: Calling getWeakReference(null) should work.
try {
var nullWeak = Components.utils.getWeakReference(null);
do_check_true(nullWeak.get() === null);
} catch (e) {
do_check_true(false);
}
var obj = { num: 5, str: 'foo' };
var weak = Components.utils.getWeakReference(obj);
do_check_true(weak.get() === obj);
do_check_true(weak.get().num == 5);
do_check_true(weak.get().str == 'foo');
// Force garbage collection
Components.utils.forceGC();
// obj still references the object, so it should still be accessible via weak
do_check_true(weak.get() === obj);
do_check_true(weak.get().num == 5);
do_check_true(weak.get().str == 'foo');
// Clear obj's reference to the object and force garbage collection. To make
// sure that there are no instances of obj stored in the registers or on the
// native stack and the conservative GC would not find it we force the same
// code paths that we used for the initial allocation.
obj = { num: 6, str: 'foo2' };
var weak2 = Components.utils.getWeakReference(obj);
do_check_true(weak2.get() === obj);
Components.utils.forceGC();
// The object should have been garbage collected and so should no longer be
// accessible via weak
do_check_true(weak.get() === null);
}