blob: 3aabb32b4867e60f371a383a27df7eacfd20ae32 [file] [log] [blame]
// Copyright (C) 2019 Leo Balter. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-finalization-registry-target
description: >
cleanupCallback has only one optional chance to be called for a GC that cleans up
a registered target.
info: |
FinalizationRegistry ( cleanupCallback )
FinalizationRegistry.prototype.cleanupSome ( [ callback ] )
...
4. If callback is not undefined and IsCallable(callback) is false, throw a TypeError exception.
5. Perform ? CleanupFinalizationRegistry(finalizationRegistry, callback).
6. Return undefined.
Execution
At any time, if an object obj is not live, an ECMAScript implementation may perform the following steps atomically:
1. For each WeakRef ref such that ref.[[Target]] is obj,
a. Set ref.[[Target]] to empty.
2. For each FinalizationRegistry finalizationRegistry such that finalizationRegistry.[[Cells]] contains cell, such that cell.[[Target]] is obj,
a. Set cell.[[Target]] to empty.
b. Optionally, perform ! HostCleanupFinalizationRegistry(finalizationRegistry).
features: [FinalizationRegistry, async-functions, host-gc-required]
flags: [async, non-deterministic]
includes: [async-gc.js]
---*/
var cleanupCallback = 0;
var called = 0;
function cb(holding) {
assert.sameValue(holding, 'a');
called += 1;
}
var finalizationRegistry = new FinalizationRegistry(function() {
cleanupCallback += 1;
});
function emptyCells() {
var target = {};
finalizationRegistry.register(target, 'a');
var prom = asyncGC(target);
target = null;
return prom;
}
emptyCells()
.then(async function() {
await Promise.resolve(1);
finalizationRegistry.cleanupSome(cb);
// cleanupSome will be invoked if there are empty cells left. If the
// cleanupCallback already ran, then cb won't be called.
let expectedCalled = cleanupCallback === 1 ? 0 : 1;
// This asserts the registered object was emptied in the previous GC.
assert.sameValue(called, expectedCalled, 'cleanupSome callback for the first time');
// At this point, we can't assert if cleanupCallback was called, because it's
// optional. Although, we can finally assert it's not gonna be called anymore
// for the other executions of the Garbage Collector.
// The chance of having it called only happens right after the
// cell.[[Target]] is set to empty.
assert(cleanupCallback >= 0, 'cleanupCallback might be 0');
assert(cleanupCallback <= 1, 'cleanupCallback might be 1');
// Restoring the cleanupCallback variable to 0 will help us asserting the
// finalizationRegistry callback is not called again.
cleanupCallback = 0;
await $262.gc();
await Promise.resolve(2); // tick
finalizationRegistry.cleanupSome(cb);
assert.sameValue(called, expectedCalled, 'cleanupSome callback is not called anymore, no empty cells');
assert.sameValue(cleanupCallback, 0, 'cleanupCallback is not called again #1');
await $262.gc();
await Promise.resolve(3); // tick
finalizationRegistry.cleanupSome(cb);
assert.sameValue(called, expectedCalled, 'cleanupSome callback is not called again #2');
assert.sameValue(cleanupCallback, 0, 'cleanupCallback is not called again #2');
await $262.gc();
})
.then($DONE, resolveAsyncGC);