From 9f1f8e6c09b77333935c65eebc8df5613c3af9f6 Mon Sep 17 00:00:00 2001
From: Andrea Boriero <andrea@hibernate.org>
Date: Mon, 13 Nov 2023 13:23:20 +0100
Subject: [PATCH] HHH-17347 Support for JDK which do not support JFR events

---
 .../engine/jdbc/env/internal/JdbcEnvironmentInitiator.java | 4 +++-
 .../org/hibernate/event/internal/EmptyEventManager.java    | 7 +------
 .../java/org/hibernate/internal/FastSessionServices.java   | 2 +-
 hibernate-jfr/hibernate-jfr.gradle                         | 4 ++--
 4 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/hibernate-core/src/main/java/org/hibernate/engine/jdbc/env/internal/JdbcEnvironmentInitiator.java b/hibernate-core/src/main/java/org/hibernate/engine/jdbc/env/internal/JdbcEnvironmentInitiator.java
index 79f6da6031..c9d04188c1 100644
--- a/hibernate-core/src/main/java/org/hibernate/engine/jdbc/env/internal/JdbcEnvironmentInitiator.java
+++ b/hibernate-core/src/main/java/org/hibernate/engine/jdbc/env/internal/JdbcEnvironmentInitiator.java
@@ -561,6 +561,7 @@ public class JdbcEnvironmentInitiator implements StandardServiceInitiator<JdbcEn
 		private final JpaCompliance jpaCompliance;
 		private static final EmptyJdbcObserver EMPTY_JDBC_OBSERVER = EmptyJdbcObserver.INSTANCE;
 		TransactionCoordinator transactionCoordinator;
+		private final EmptyEventManager eventManager;
 
 		public TemporaryJdbcSessionOwner(
 				JdbcConnectionAccess jdbcConnectionAccess,
@@ -590,6 +591,7 @@ public class JdbcEnvironmentInitiator implements StandardServiceInitiator<JdbcEn
 						.getDefaultConnectionHandlingMode();
 			}
 			this.jpaCompliance = new MutableJpaComplianceImpl( Collections.emptyMap(), false );
+			this.eventManager = new EmptyEventManager();
 		}
 
 		@Override
@@ -639,7 +641,7 @@ public class JdbcEnvironmentInitiator implements StandardServiceInitiator<JdbcEn
 
 		@Override
 		public EventManager getEventManager() {
-			return EmptyEventManager.INSTANCE;
+			return eventManager;
 		}
 
 		@Override
diff --git a/hibernate-core/src/main/java/org/hibernate/event/internal/EmptyEventManager.java b/hibernate-core/src/main/java/org/hibernate/event/internal/EmptyEventManager.java
index 2d2b142f85..5cdeae32fb 100644
--- a/hibernate-core/src/main/java/org/hibernate/event/internal/EmptyEventManager.java
+++ b/hibernate-core/src/main/java/org/hibernate/event/internal/EmptyEventManager.java
@@ -17,13 +17,8 @@ import org.hibernate.event.spi.FlushEvent;
 import org.hibernate.persister.collection.CollectionPersister;
 import org.hibernate.persister.entity.EntityPersister;
 
-public class EmptyEventManager implements EventManager {
+public final class EmptyEventManager implements EventManager {
 
-	public static final EmptyEventManager INSTANCE = new EmptyEventManager();
-
-	private EmptyEventManager(){
-
-	}
 	@Override
 	public HibernateEvent beginSessionOpenEvent() {
 		return null;
diff --git a/hibernate-core/src/main/java/org/hibernate/internal/FastSessionServices.java b/hibernate-core/src/main/java/org/hibernate/internal/FastSessionServices.java
index 3fcd427fff..73c162680e 100644
--- a/hibernate-core/src/main/java/org/hibernate/internal/FastSessionServices.java
+++ b/hibernate-core/src/main/java/org/hibernate/internal/FastSessionServices.java
@@ -275,7 +275,7 @@ public final class FastSessionServices {
 		this.batchBuilder = serviceRegistry.getService( BatchBuilder.class );
 		final Collection<EventManager> eventManagers = classLoaderService.loadJavaServices( EventManager.class );
 		this.eventManager = eventManagers.isEmpty()
-				? EmptyEventManager.INSTANCE
+				? new EmptyEventManager()
 				: eventManagers.iterator().next();
 	}
 
diff --git a/hibernate-jfr/hibernate-jfr.gradle b/hibernate-jfr/hibernate-jfr.gradle
index de52eac5af..b3c47e306b 100644
--- a/hibernate-jfr/hibernate-jfr.gradle
+++ b/hibernate-jfr/hibernate-jfr.gradle
@@ -19,9 +19,9 @@ dependencies {
 
 // JfrUnit requires JDK 17
 compileTestJava.onlyIf{
-    jdkVersions.test.release.asInt() >= 17 && jdkVersions.explicit
+    jdkVersions.test.release.asInt() >= 17
 }
 
 test.onlyIf {
-    jdkVersions.test.release.asInt() >= 17 && jdkVersions.explicit
+    jdkVersions.test.release.asInt() >= 17
 }
\ No newline at end of file