Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

lib: add aborted() utility function #46494

Merged
merged 26 commits into from
Feb 7, 2023
Merged
Show file tree
Hide file tree
Changes from 1 commit
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 18 additions & 0 deletions lib/internal/abort_controller.js
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@ const {
Symbol,
SymbolToStringTag,
WeakRef,
PromiseResolve,
aduh95 marked this conversation as resolved.
Show resolved Hide resolved
} = primordials;

const {
Expand All @@ -22,11 +23,13 @@ const {
kTrustEvent,
kNewListener,
kRemoveListener,
kWeakHandler,
} = require('internal/event_target');
const {
customInspectSymbol,
kEnumerableProperty,
kEmptyObject,
createDeferredPromise,
debadree25 marked this conversation as resolved.
Show resolved Hide resolved
} = require('internal/util');
const { inspect } = require('internal/util/inspect');
const {
Expand Down Expand Up @@ -357,6 +360,20 @@ function transferableAbortController() {
return AbortController[kMakeTransferable]();
}

/**
* @param {AbortSignal} signal
* @param {any} resource
* @returns {Promise<void>}
*/
function aborted(signal, resource = null) {
aduh95 marked this conversation as resolved.
Show resolved Hide resolved
validateAbortSignal(signal, 'signal');
if (signal.aborted)
return PromiseResolve();
const abortPromise = createDeferredPromise();
signal.addEventListener('abort', abortPromise.resolve, { [kWeakHandler]: resource, once: true });
aduh95 marked this conversation as resolved.
Show resolved Hide resolved
aduh95 marked this conversation as resolved.
Show resolved Hide resolved
return abortPromise.promise;
}

ObjectDefineProperties(AbortController.prototype, {
signal: kEnumerableProperty,
abort: kEnumerableProperty,
Expand All @@ -377,4 +394,5 @@ module.exports = {
ClonedAbortSignal,
transferableAbortSignal,
transferableAbortController,
aborted,
debadree25 marked this conversation as resolved.
Show resolved Hide resolved
};
3 changes: 3 additions & 0 deletions lib/util.js
Original file line number Diff line number Diff line change
Expand Up @@ -393,6 +393,9 @@ module.exports = {
get transferableAbortController() {
return lazyAbortController().transferableAbortController;
},
get aborted() {
return lazyAbortController().aborted;
},
types
};

Expand Down
37 changes: 37 additions & 0 deletions test/parallel/test-aborted-util.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,37 @@
// Flags: --expose-gc
'use strict';

const common = require('../common');
const { aborted } = require('util');
const assert = require('assert');
const { getEventListeners } = require('events');

{
// Test aborted works
const ac = new AbortController();
aborted(ac.signal).then(common.mustCall());
ac.abort();
assert.strictEqual(ac.signal.aborted, true);
assert.strictEqual(getEventListeners(ac.signal, 'abort').length, 0);
}

{
// Test aborted works when provided a resource
const ac = new AbortController();
aborted(ac.signal, {}).then(common.mustCall());
ac.abort();
assert.strictEqual(ac.signal.aborted, true);
assert.strictEqual(getEventListeners(ac.signal, 'abort').length, 0);
}

{
// Test aborted with gc cleanup
const ac = new AbortController();
aborted(ac.signal, {}).then(common.mustNotCall());
setImmediate(() => {
global.gc();
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

What does GC accomplish here? That the aborted() promise is collected before abort() is called?

I don't know if that kind of GC observability is a good thing. Maybe it works now but GC changes can break such patterns. Looks fragile.

Copy link
Member Author

@debadree25 debadree25 Feb 4, 2023

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

basically want to cleanup the empty object to check if the listener is removed when the resource is cleaned by the gc, unsure of any other ways to test this

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

If it's just for testing, then it's probably fine. I mean, it could still break in the future but we can revisit if and when that happens.

I'd advise against documenting that behavior though. It's simply not very robust.

ac.abort();
assert.strictEqual(ac.signal.aborted, true);
assert.strictEqual(getEventListeners(ac.signal, 'abort').length, 0);
});
}