From f7feb020c3d8d5aff24204af28359b99ee65bf8f Mon Sep 17 00:00:00 2001 From: Thomas Munro Date: Fri, 12 Apr 2019 14:53:38 +1200 Subject: [PATCH] Fix GetNewTransactionId()'s interaction with xidVacLimit. Commit ad308058 switched to returning a FullTransactionId, but failed to load the potentially updated value in the case where xidVacLimit is reached and we release and reacquire the lock. Repair, closing bug #15727. While reviewing that commit, also fix the size computation used by EstimateTransactionStateSize() and switch to the mul_size() macro traditionally used in such expressions. Author: Thomas Munro Reported-by: Roman Zharkov Discussion: https://postgr.es/m/15727-0be246e7d852d229%40postgresql.org --- src/backend/access/transam/varsup.c | 3 ++- src/backend/access/transam/xact.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 8c3d84fbf2..788b961ef0 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -159,7 +159,8 @@ GetNewTransactionId(bool isSubXact) /* Re-acquire lock and start over */ LWLockAcquire(XidGenLock, LW_EXCLUSIVE); - xid = XidFromFullTransactionId(ShmemVariableCache->nextFullXid); + full_xid = ShmemVariableCache->nextFullXid; + xid = XidFromFullTransactionId(full_xid); } /* diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 816fd626ec..8522a2f51c 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -5151,7 +5151,7 @@ EstimateTransactionStateSpace(void) nxids = add_size(nxids, s->nChildXids); } - return add_size(size, sizeof(SerializedTransactionState) * nxids); + return add_size(size, mul_size(sizeof(TransactionId), nxids)); } /* -- 2.40.0