From fd18c00e50a048c5d357033e61d402f0b01002e8 Mon Sep 17 00:00:00 2001
From: Philippe Marschall <philippe.marschall@gmail.com>
Date: Mon, 30 Aug 2021 13:06:14 +0200
Subject: [PATCH] Optimize for single TransactionSynchronization

Optimize TransactionSynchronizationManager.getSynchronizations() to
avoid sorting and ArrayList creation in case of a single
TransactionSynchronization.

See gh-27335
---
 .../transaction/support/TransactionSynchronizationManager.java | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/spring-tx/src/main/java/org/springframework/transaction/support/TransactionSynchronizationManager.java b/spring-tx/src/main/java/org/springframework/transaction/support/TransactionSynchronizationManager.java
index 85cd680ad8b..f7fb0d40c0d 100644
--- a/spring-tx/src/main/java/org/springframework/transaction/support/TransactionSynchronizationManager.java
+++ b/spring-tx/src/main/java/org/springframework/transaction/support/TransactionSynchronizationManager.java
@@ -297,6 +297,9 @@ public abstract class TransactionSynchronizationManager {
 		if (synchs.isEmpty()) {
 			return Collections.emptyList();
 		}
+		else if (synchs.size() == 1) {
+			return Collections.singletonList(synchs.iterator().next());
+		}
 		else {
 			// Sort lazily here, not in registerSynchronization.
 			List<TransactionSynchronization> sortedSynchs = new ArrayList<>(synchs);