On Sun, Oct 24, 2021 at 09:08:01AM +0530, Bharath Rupireddy wrote:
> pg_get_replication_slots holds the ReplicationSlotControlLock until
> the end of the function so it can be assured that *slot contents will
> not change. In ReadReplicationSlot, the ReplicationSlotControlLock is
> released immediately after taking *slot pointer into slot_contents.
> Isn't it better if we hold the lock until the end of the function so
> that we can avoid the slot contents becoming stale problems?
The reason is different in the case of pg_get_replication_slots(). We
have to hold ReplicationSlotControlLock for the whole duration of the
shared memory scan to return back to the user a consistent set of
information to the user, for all the slots.
--
Michael
