Racing immediately-resolving Promises leads to memory leak

Why this is a good first issue

Memory leak in Promise.race/any with immediately-resolving promises requires investigation of Node.js internals.

AI Summary

The issue demonstrates a memory leak when using Promise.race or Promise.any with immediately-resolving promises in a loop. The problem appears specific to Node.js (not V8 alone) and requires understanding of async_hooks or promise implementation details. Maintainers have confirmed the bug but the root cause isn't yet identified.

Issue Description

Version

21.5.0

Platform

Linux penguin 6.1.55-06877-gc83437f2949f #1 SMP PREEMPT_DYNAMIC Thu Dec 14 19:17:39 PST 2023 x86_64 GNU/Linux

Subsystem

async_hooks or async/await

What steps will reproduce the bug?

Run the following code. Failure is quicker and less likely to interfere with system stability if you run with a low heap ceiling like this, but it will fail without...

node --max-old-space-size=16 test/examples/ephemeralPromiseMemoryLeak.js

//ephemeralPromiseMemoryLeak.js

async function promiseValue(value) {
  return value;
}

async function run() {
  for (;;) {
    await Promise.race([promiseValue("foo"), promiseValue("bar")]);
  }
}

run();

An equivalent OOM is created if you substitute Promise.any for Promise.race...

async function promiseValue(value) {
  return value;
}

async function run() {
  for (;;) {
    await Promise.any([promiseValue("foo"), promiseValue("bar")]);
  }
}

run();

How often does it reproduce? Is there a required condition?

It always fails.

What is the expected behavior? Why is that the expected behavior?

I would expect it not to accumulate references in memory and fail.

What do you see instead?

Fails with the following error

✗ node test/examples/ephemeralPromiseMemoryLeak.js

<--- Last few GCs --->

[31511:0x6de4330]    39874 ms: Mark-Compact (reduce) 2048.2 (2083.6) -> 2047.3 (2083.9) MB, 1308.67 / 0.00 ms  (average mu = 0.071, current mu = 0.001) allocation failure; scavenge might not succeed


<--- JS stacktrace --->

FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory
----- Native stack trace -----

 1: 0xcc062a node::OOMErrorHandler(char const*, v8::OOMDetails const&) [node]
 2: 0x104eb90 v8::Utils::ReportOOMFailure(v8::internal::Isolate*, char const*, v8::OOMDetails const&) [node]
 3: 0x104ee77 v8::internal::V8::FatalPr

GitHub Labels

confirmed-bugperformancepromises