Dear Sawada-san, Thank you for making the patch! I'm still considering whether this approach is correct, but I can put a comment to your patch anyway.
``` - Assert(!already_locked || LWLockHeldByMe(ProcArrayLock)); - - if (!already_locked) - LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE); + Assert(LWLockHeldByMe(ProcArrayLock)); ``` In this function, we regard that the ProcArrayLock has been already acquired as exclusive mode and modify data. I think LWLockHeldByMeInMode() should be used instead of LWLockHeldByMe(). I confirmed that there is only one caller that uses ReplicationSlotsComputeRequiredXmin(true) and it acquires exclusive lock correctly, but it can avoid future bug. Best Regards, Hayato Kuroda FUJITSU LIMITED
