From 61a75accf5a6e8d20444726a46b52a211f0bc9e9 Mon Sep 17 00:00:00 2001
From: Sanne Grinovero <sanne@hibernate.org>
Date: Wed, 13 Nov 2013 14:10:37 +0000
Subject: [PATCH] HHH-8680 Relax synchronized block in TableGenerator#generate

---
 .../java/org/hibernate/id/enhanced/NoopOptimizer.java | 11 ++++++++---
 .../java/org/hibernate/id/enhanced/Optimizer.java     |  3 +++
 .../org/hibernate/id/enhanced/TableGenerator.java     |  2 +-
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/hibernate-core/src/main/java/org/hibernate/id/enhanced/NoopOptimizer.java b/hibernate-core/src/main/java/org/hibernate/id/enhanced/NoopOptimizer.java
index aba217aa91..8e748a3ee8 100644
--- a/hibernate-core/src/main/java/org/hibernate/id/enhanced/NoopOptimizer.java
+++ b/hibernate-core/src/main/java/org/hibernate/id/enhanced/NoopOptimizer.java
@@ -30,9 +30,14 @@ import org.hibernate.id.IntegralDataTypeHolder;
 /**
  * An optimizer that performs no optimization.  The database is hit for
  * every request.
+ *
+ * @deprecated This is the fallback Optimizer chosen when we fail to instantiate one
+ * of the proper implementations. Using this implementation is probably a performance
+ * problem.
  */
-public class NoopOptimizer extends AbstractOptimizer {
-	private IntegralDataTypeHolder lastSourceValue;
+@Deprecated
+public final class NoopOptimizer extends AbstractOptimizer {
+	private volatile IntegralDataTypeHolder lastSourceValue;
 
 	/**
 	 * Constructs a NoopOptimizer
@@ -45,7 +50,7 @@ public class NoopOptimizer extends AbstractOptimizer {
 	}
 
 	@Override
-	public Serializable generate(AccessCallback callback) {
+	public synchronized Serializable generate(AccessCallback callback) {
 		// IMPL NOTE : it is incredibly important that the method-local variable be used here to
 		//		avoid concurrency issues.
 		IntegralDataTypeHolder value = null;
diff --git a/hibernate-core/src/main/java/org/hibernate/id/enhanced/Optimizer.java b/hibernate-core/src/main/java/org/hibernate/id/enhanced/Optimizer.java
index e161739ca5..b9660c4815 100644
--- a/hibernate-core/src/main/java/org/hibernate/id/enhanced/Optimizer.java
+++ b/hibernate-core/src/main/java/org/hibernate/id/enhanced/Optimizer.java
@@ -44,6 +44,9 @@ public interface Optimizer {
 	/**
 	 * Generate an identifier value accounting for this specific optimization.
 	 *
+	 * All known implementors are synchronized. Consider carefully if a new
+	 * implementation could drop this requirement.
+	 *
 	 * @param callback Callback to access the underlying value source.
 	 * @return The generated identifier value.
 	 */
diff --git a/hibernate-core/src/main/java/org/hibernate/id/enhanced/TableGenerator.java b/hibernate-core/src/main/java/org/hibernate/id/enhanced/TableGenerator.java
index 8f5b0b7fbe..6847a1a3af 100644
--- a/hibernate-core/src/main/java/org/hibernate/id/enhanced/TableGenerator.java
+++ b/hibernate-core/src/main/java/org/hibernate/id/enhanced/TableGenerator.java
@@ -525,7 +525,7 @@ public class TableGenerator implements PersistentIdentifierGenerator, Configurab
 	}
 
 	@Override
-	public synchronized Serializable generate(final SessionImplementor session, Object obj) {
+	public Serializable generate(final SessionImplementor session, final Object obj) {
 		final SqlStatementLogger statementLogger = session.getFactory().getServiceRegistry()
 				.getService( JdbcServices.class )
 				.getSqlStatementLogger();