HybridJacksonPool can lose pooled recyclers due to stack node publication race

[dreamlike-ocean]

Version

every version

Context

HybridJacksonPool.StripedLockFreePool#releasePooled publishes a new stack head with CAS before initializing the node's next pointer.

current:

if (topStacks.compareAndSet(slot, next, newHead)) {
  newHead.next = next;
  return;
}

A concurrent acquirePooled can observe newHead immediately after the CAS, before newHead.next is assigned. In that window it may pop newHead and replace the stack head with null, detaching the previous stack.

I will submit a pr to fix it

Steps to reproduce

No response

Do you have a reproducer?

No response

[tsegismont]

Fixed by #6114

[tsegismont]

Thank you @dreamlike-ocean !