Clear kResourceStore in timers and intervals

As noted in this article, the timeout/interval objects keep a reference to the store even after they have been cleared.

I think it would be better to clear up that reference inside the clearTimeout() and clearInterval() functions. We might also want to consider exposing an API for end-users and explicit lifetime tracking.

@anonrig

cc @nodejs/diagnostics @anonrig

setTimeout should probably actually just clear immediately after running given that it only occurs once. But yes, also clearing in clearInterval makes sense to me too.

I guess this is not only relevant for timers and intervals, all resources are effected.

const { AsyncLocalStorage, AsyncResource } = require('node:async_hooks');
const als = new AsyncLocalStorage();
let r, p;
als.run("I consume a lot memory", () => {
  r = new AsyncResource("aResource", { requireManualDestroy: true })
  r.emitDestroy()
  p = Promise.resolve()
})
console.log(r, p);

 AsyncResource {
  [Symbol(async_id_symbol)]: 2,
  [Symbol(trigger_async_id_symbol)]: 1,
  [Symbol(kResourceStore)]: 'I consume a lot memory'
} Promise {
  undefined,
  [Symbol(async_id_symbol)]: 3,
  [Symbol(trigger_async_id_symbol)]: 1,
  [Symbol(kResourceStore)]: 'I consume a lot memory'
}

For timers/intervals it's likely easier to find the place to cleanup.
Maybe we can extend the cleanup to some more places?

Absolutely!

timers allow similar "leaks" even without AsyncLocalStore if one uses arguments for the handler:

const t = setTimeout(() => {}, 100, "I consume a lot memory");
clearTimeout(t);
console.log(t);
console.log(t._timerArgs);

Timeout {
  _idleTimeout: -1,
  _idlePrev: null,
  _idleNext: null,
  _idleStart: 22,
  _onTimeout: null,
  _timerArgs: [Array],
  _repeat: null,
  _destroyed: true,
  [Symbol(refed)]: true,
  [Symbol(kHasPrimitive)]: false,
  [Symbol(asyncId)]: 2,
  [Symbol(triggerId)]: 1
}
[ 'I consume a lot memory' ]

If handler uses some variable from the outer scope it's even more.

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This issue has been automatically closed after 30 days of inactivity following its stale status (no activity for a total of 240 days).
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timers: do not retain a reference to the async store after firing

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Clear kResourceStore in timers and intervals #53408

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Clear kResourceStore in timers and intervals #53408

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mcollina commented on Jun 10, 2024

Qard commented on Jun 10, 2024

Flarna commented on Jun 11, 2024

mcollina commented on Jun 11, 2024

Flarna commented on Jun 28, 2024

github-actions commented on May 20, 2026

github-actions commented on Jun 19, 2026

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