Fix comments atop ReorderBufferAddInvalidations.

The comments atop seem to indicate that we always accumulate invalidation
messages in a top-level transaction which is neither required nor matches
with the code.

Author: Amit Kapila
Reviewd by: Masahiko Sawada
Backpatch-through: 14, where it was introduced in commit c55040ccd0
Discussion: https://postgr.es/m/CAA4eK1LxGgnUroPz8STb6OfjVU1yaHoSA+T63URwmGCLdMJ0LA@mail.gmail.com
This commit is contained in:
Amit Kapila 2022-11-10 17:08:27 +05:30
parent 5962c8cbe5
commit daadb42e92
1 changed files with 12 additions and 10 deletions

View File

@ -3204,16 +3204,17 @@ ReorderBufferAddNewTupleCids(ReorderBuffer *rb, TransactionId xid,
}
/*
* Setup the invalidation of the toplevel transaction.
* Accumulate the invalidations for executing them later.
*
* This needs to be called for each XLOG_XACT_INVALIDATIONS message and
* accumulates all the invalidation messages in the toplevel transaction as
* well as in the form of change in reorder buffer. We require to record it in
* form of the change so that we can execute only the required invalidations
* instead of executing all the invalidations on each CommandId increment. We
* also need to accumulate these in the toplevel transaction because in some
* cases we skip processing the transaction (see ReorderBufferForget), we need
* to execute all the invalidations together.
* accumulates all the invalidation messages in the toplevel transaction, if
* available, otherwise in the current transaction, as well as in the form of
* change in reorder buffer. We require to record it in form of the change
* so that we can execute only the required invalidations instead of executing
* all the invalidations on each CommandId increment. We also need to
* accumulate these in the txn buffer because in some cases where we skip
* processing the transaction (see ReorderBufferForget), we need to execute
* all the invalidations together.
*/
void
ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid,
@ -3229,8 +3230,9 @@ ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid,
oldcontext = MemoryContextSwitchTo(rb->context);
/*
* Collect all the invalidations under the top transaction so that we can
* execute them all together. See comment atop this function
* Collect all the invalidations under the top transaction, if available,
* so that we can execute them all together. See comments atop this
* function.
*/
if (txn->toptxn)
txn = txn->toptxn;