From 33f02f411f71f75ff78fe476ea836048709bf400 Mon Sep 17 00:00:00 2001
From: Sanne Grinovero <sanne@hibernate.org>
Date: Thu, 20 Jun 2019 10:33:45 +0100
Subject: [PATCH] HHH-13447 Minimize number of EventListenerRegistry lookups
 within a Session use

---
 .../src/main/java/org/hibernate/internal/SessionImpl.java   | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/hibernate-core/src/main/java/org/hibernate/internal/SessionImpl.java b/hibernate-core/src/main/java/org/hibernate/internal/SessionImpl.java
index 16189e6278..244379182b 100644
--- a/hibernate-core/src/main/java/org/hibernate/internal/SessionImpl.java
+++ b/hibernate-core/src/main/java/org/hibernate/internal/SessionImpl.java
@@ -242,6 +242,7 @@ public final class SessionImpl
 	private transient boolean discardOnClose;
 
 	private transient TransactionObserver transactionObserver;
+	private transient EventListenerRegistry eventListenerRegistry;
 
 	public SessionImpl(SessionFactoryImpl factory, SessionCreationOptions options) {
 		super( factory, options );
@@ -678,7 +679,10 @@ public final class SessionImpl
 	}
 
 	private <T> EventListenerGroup<T> eventListenerGroup(EventType<T> type) {
-		return getFactory().getServiceRegistry().getService( EventListenerRegistry.class ).getEventListenerGroup( type );
+		if ( this.eventListenerRegistry == null ) {
+			this.eventListenerRegistry = getFactory().getServiceRegistry().getService( EventListenerRegistry.class );
+		}
+		return eventListenerRegistry.getEventListenerGroup( type );
 	}