postgrespro.git / summary / log / commit / refs

commit    f7feb020c3d8d5aff24204af28359b99ee65bf8f
Author:   Thomas Munro <tmunro@postgresql.org>
Date:     Fri Apr 12 02:53:38 2019 +0000

    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));
 }
 
 /*


[parent: d87ab88686fb]