On 11/6/24 06:23, Amit Kapila wrote:
I think we avoid calling hook/callback functions after holding a lock (spinlock or LWLock) as the user may do an expensive operation or acquire some other locks in those functions which could lead to deadlocks or impact the concurrency. So, it would be better to directly call an inline function to perform the required operation.
This is a valid concern. The reason why I kept it as a hook is because ReserveXLogInsertLocation() has no knowledge that this is allocating WAL space for a commit record. Only the caller does. We certainly need to be extremely careful what any such hook function is doing. Acquiring additional locks is definitely not acceptable. But I am not sure we should burden this function with specialized knowledge about what it is reserving WAL space for.
Regards, Jan
