From cf461639582b99c428c8ce155c4de01ba5a6f9d9 Mon Sep 17 00:00:00 2001
From: Nathan Xu <nathan.qingyang.xu@gmail.com>
Date: Sat, 29 Feb 2020 22:25:49 -0500
Subject: [PATCH] Fix a subtle double-checked locking issue

---
 .../persister/collection/AbstractCollectionPersister.java       | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hibernate-core/src/main/java/org/hibernate/persister/collection/AbstractCollectionPersister.java b/hibernate-core/src/main/java/org/hibernate/persister/collection/AbstractCollectionPersister.java
index f42cd9cb1d..25ef03db87 100644
--- a/hibernate-core/src/main/java/org/hibernate/persister/collection/AbstractCollectionPersister.java
+++ b/hibernate-core/src/main/java/org/hibernate/persister/collection/AbstractCollectionPersister.java
@@ -753,7 +753,7 @@ public abstract class AbstractCollectionPersister
 	}
 
 	// lazily initialize instance field via 'double-checked locking'
-	// see https://en.wikipedia.org/wiki/Double-checked_locking
+	// see https://en.wikipedia.org/wiki/Double-checked_locking on why 'volatile' and local copy is used
 	protected CollectionLoader getStandardCollectionLoader() {
 		CollectionLoader localCopy = standardCollectionLoader;
 		if ( localCopy == null ) {