From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Fri, 4 Apr 2014 15:20:22 +0000 (+0300)
Subject: Move multixid allocation out of critical section.
X-Git-Tag: REL9_3_5~120
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a2f9572ca507bfcb71bcf1b81b563e5094fd6904;p=postgresql

Move multixid allocation out of critical section.

It can fail if you run out of memory.

This call was added in 9.3, so backpatch to 9.3 only.
---

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index d94980bbc1..9283b70a42 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -2717,6 +2717,21 @@ l1:
 	/* replace cid with a combo cid if necessary */
 	HeapTupleHeaderAdjustCmax(tp.t_data, &cid, &iscombo);
 
+	/*
+	 * If this is the first possibly-multixact-able operation in the current
+	 * transaction, set my per-backend OldestMemberMXactId setting. We can be
+	 * certain that the transaction will never become a member of any older
+	 * MultiXactIds than that.	(We have to do this even if we end up just
+	 * using our own TransactionId below, since some other backend could
+	 * incorporate our XID into a MultiXact immediately afterwards.)
+	 */
+	MultiXactIdSetOldestMember();
+
+	compute_new_xmax_infomask(HeapTupleHeaderGetRawXmax(tp.t_data),
+							  tp.t_data->t_infomask, tp.t_data->t_infomask2,
+							  xid, LockTupleExclusive, true,
+							  &new_xmax, &new_infomask, &new_infomask2);
+
 	START_CRIT_SECTION();
 
 	/*
@@ -2736,21 +2751,6 @@ l1:
 							vmbuffer);
 	}
 
-	/*
-	 * If this is the first possibly-multixact-able operation in the current
-	 * transaction, set my per-backend OldestMemberMXactId setting. We can be
-	 * certain that the transaction will never become a member of any older
-	 * MultiXactIds than that.	(We have to do this even if we end up just
-	 * using our own TransactionId below, since some other backend could
-	 * incorporate our XID into a MultiXact immediately afterwards.)
-	 */
-	MultiXactIdSetOldestMember();
-
-	compute_new_xmax_infomask(HeapTupleHeaderGetRawXmax(tp.t_data),
-							  tp.t_data->t_infomask, tp.t_data->t_infomask2,
-							  xid, LockTupleExclusive, true,
-							  &new_xmax, &new_infomask, &new_infomask2);
-
 	/* store transaction information of xact deleting the tuple */
 	tp.t_data->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED);
 	tp.t_data->t_infomask2 &= ~HEAP_KEYS_UPDATED;