PG17-0001-Avoid-distributing-invalidation-messages-several-tim.patch

From 259a1f79511bb5acb03167e44eadb2d3fd5ab644 Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Date: Wed, 21 May 2025 18:02:36 +0900
Subject: [PATCH] Avoid distributing invalidation messages several times

---
 .../replication/logical/reorderbuffer.c       | 71 ++++++++++++-------
 src/backend/replication/logical/snapbuild.c   |  5 +-
 src/include/replication/reorderbuffer.h       |  3 +
 3 files changed, 51 insertions(+), 28 deletions(-)

diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index 03eb005c39d..868fcd8a344 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -3330,41 +3330,60 @@ ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid,
 							  XLogRecPtr lsn, Size nmsgs,
 							  SharedInvalidationMessage *msgs)
 {
-	ReorderBufferTXN *txn;
+	ReorderBufferAddInvalidationsExtended(rb, xid, lsn, nmsgs, msgs, true);
+}
+
+/*
+ * An extended workhorse version of ReorderBufferAddInvalidations(). This can
+ * control whether invalidation messages can be accumulated in reorderbuffer
+ * transactions, which would be distributed to all concurrent transactions at
+ * commit.
+ */
+void
+ReorderBufferAddInvalidationsExtended(ReorderBuffer *rb, TransactionId xid,
+									  XLogRecPtr lsn, Size nmsgs,
+									  SharedInvalidationMessage *msgs,
+									  bool needs_distribute)
+{
 	MemoryContext oldcontext;
 	ReorderBufferChange *change;
 
-	txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
-
 	oldcontext = MemoryContextSwitchTo(rb->context);
 
-	/*
-	 * Collect all the invalidations under the top transaction, if available,
-	 * so that we can execute them all together.  See comments atop this
-	 * function.
-	 */
-	txn = rbtxn_get_toptxn(txn);
-
 	Assert(nmsgs > 0);
 
-	/* Accumulate invalidations. */
-	if (txn->ninvalidations == 0)
-	{
-		txn->ninvalidations = nmsgs;
-		txn->invalidations = (SharedInvalidationMessage *)
-			palloc(sizeof(SharedInvalidationMessage) * nmsgs);
-		memcpy(txn->invalidations, msgs,
-			   sizeof(SharedInvalidationMessage) * nmsgs);
-	}
-	else
+	if (needs_distribute)
 	{
-		txn->invalidations = (SharedInvalidationMessage *)
-			repalloc(txn->invalidations, sizeof(SharedInvalidationMessage) *
-					 (txn->ninvalidations + nmsgs));
+		ReorderBufferTXN *txn;
+
+		txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
+
+		/*
+		 * Collect all the invalidations under the top transaction, if
+		 * available, so that we can execute them all together.  See comments
+		 * atop ReorderBufferAddInvalidations.
+		 */
+		txn = rbtxn_get_toptxn(txn);
 
-		memcpy(txn->invalidations + txn->ninvalidations, msgs,
-			   nmsgs * sizeof(SharedInvalidationMessage));
-		txn->ninvalidations += nmsgs;
+		/* Accumulate invalidations. */
+		if (txn->ninvalidations == 0)
+		{
+			txn->ninvalidations = nmsgs;
+			txn->invalidations = (SharedInvalidationMessage *)
+				palloc(sizeof(SharedInvalidationMessage) * nmsgs);
+			memcpy(txn->invalidations, msgs,
+				   sizeof(SharedInvalidationMessage) * nmsgs);
+		}
+		else
+		{
+			txn->invalidations = (SharedInvalidationMessage *)
+				repalloc(txn->invalidations,
+						 sizeof(SharedInvalidationMessage) * (txn->ninvalidations + nmsgs));
+
+			memcpy(txn->invalidations + txn->ninvalidations, msgs,
+				   nmsgs * sizeof(SharedInvalidationMessage));
+			txn->ninvalidations += nmsgs;
+		}
 	}
 
 	change = ReorderBufferGetChange(rb);
diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c
index 110e0b0a044..a8225c1d905 100644
--- a/src/backend/replication/logical/snapbuild.c
+++ b/src/backend/replication/logical/snapbuild.c
@@ -945,8 +945,9 @@ SnapBuildDistributeSnapshotAndInval(SnapBuild *builder, XLogRecPtr lsn, Transact
 			{
 				Assert(msgs != NULL);
 
-				ReorderBufferAddInvalidations(builder->reorder, txn->xid, lsn,
-											  ninvalidations, msgs);
+				ReorderBufferAddInvalidationsExtended(builder->reorder, txn->xid, lsn,
+													  ninvalidations, msgs,
+													  false);
 			}
 		}
 	}
diff --git a/src/include/replication/reorderbuffer.h b/src/include/replication/reorderbuffer.h
index 4c56f219fd8..001d0e716aa 100644
--- a/src/include/replication/reorderbuffer.h
+++ b/src/include/replication/reorderbuffer.h
@@ -709,6 +709,9 @@ extern void ReorderBufferAddNewTupleCids(ReorderBuffer *rb, TransactionId xid,
 										 CommandId cmin, CommandId cmax, CommandId combocid);
 extern void ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn,
 										  Size nmsgs, SharedInvalidationMessage *msgs);
+extern void ReorderBufferAddInvalidationsExtended(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn,
+												  Size nmsgs, SharedInvalidationMessage *msgs,
+												  bool needs_distribute);
 extern void ReorderBufferImmediateInvalidation(ReorderBuffer *rb, uint32 ninvalidations,
 											   SharedInvalidationMessage *invalidations);
 extern void ReorderBufferProcessXid(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn);
-- 
2.43.5