HHH-15782 use a Generator for seeding/incrementing versions

add javadoc for version generation

hibernate-core/src/main/java/org/hibernate/action/internal/AbstractEntityInsertAction.java

@@ -11,13 +11,11 @@ import org.hibernate.collection.spi.PersistentCollection;
 import org.hibernate.engine.internal.ForeignKeys;
 import org.hibernate.engine.internal.NonNullableTransientDependencies;
 import org.hibernate.engine.internal.Nullability;
-import org.hibernate.engine.internal.Versioning;
 import org.hibernate.engine.spi.CachedNaturalIdValueSource;
 import org.hibernate.engine.spi.CollectionKey;
 import org.hibernate.engine.spi.EntityEntry;
 import org.hibernate.engine.spi.EntityKey;
 import org.hibernate.engine.spi.PersistenceContext;
-import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.engine.spi.Status;
 import org.hibernate.event.spi.EventSource;
 import org.hibernate.metamodel.mapping.NaturalIdMapping;
@@ -26,6 +24,8 @@ import org.hibernate.persister.collection.CollectionPersister;
 import org.hibernate.persister.entity.AbstractEntityPersister;
 import org.hibernate.persister.entity.EntityPersister;
 
+import static org.hibernate.engine.internal.Versioning.getVersion;
+
 /**
  * A base class for entity insert actions.
  *
@@ -127,7 +127,7 @@ public abstract class AbstractEntityInsertAction extends EntityAction {
 	 */
 	public final void makeEntityManaged() {
 		nullifyTransientReferencesIfNotAlready();
-		final Object version = Versioning.getVersion( getState(), getPersister() );
+		final Object version = getVersion( getState(), getPersister() );
 		final PersistenceContext persistenceContextInternal = getSession().getPersistenceContextInternal();
 		persistenceContextInternal.addEntity(
 				getInstance(),

hibernate-core/src/main/java/org/hibernate/action/internal/EntityUpdateAction.java

@@ -12,7 +12,6 @@ import org.hibernate.cache.CacheException;
 import org.hibernate.cache.spi.access.EntityDataAccess;
 import org.hibernate.cache.spi.access.SoftLock;
 import org.hibernate.cache.spi.entry.CacheEntry;
-import org.hibernate.engine.internal.Versioning;
 import org.hibernate.engine.spi.CachedNaturalIdValueSource;
 import org.hibernate.engine.spi.EntityEntry;
 import org.hibernate.engine.spi.SessionEventListenerManager;
@@ -33,6 +32,8 @@ import org.hibernate.stat.spi.StatisticsImplementor;
 import org.hibernate.tuple.entity.EntityMetamodel;
 import org.hibernate.type.TypeHelper;
 
+import static org.hibernate.engine.internal.Versioning.getVersion;
+
 /**
  * The action for performing entity updates.
  */
@@ -239,7 +240,7 @@ public class EntityUpdateAction extends EntityAction {
 			// have the entity entry doAfterTransactionCompletion post-update processing, passing it the
 			// update state and the new version (if one).
 			if ( persister.isVersionPropertyGenerated() ) {
-				nextVersion = Versioning.getVersion( state, persister );
+				nextVersion = getVersion( state, persister );
 			}
 			entry.postUpdate( instance, state, nextVersion );
 		}

hibernate-core/src/main/java/org/hibernate/annotations/ValueGenerationType.java

@@ -47,14 +47,13 @@ import static java.lang.annotation.RetentionPolicy.RUNTIME;
  * property to be generated when any SQL statement to {@code insert} or
  * {@code update} the entity is executed.
  * <p>
- * Every generator annotation type has an {@link Generator}
+ * Every generator annotation type has an {@link Generator} implementation which
- * implementation which is responsible for generating values. It must be either:
+ * is responsible for generating values. It must be either:
  * <ul>
- * <li>an {@link InMemoryGenerator}, for
+ * <li>an {@link InMemoryGenerator}, for values that are generated in Java code,
- *     values that are generated in Java code, using a
+ *     using a {@link org.hibernate.tuple.ValueGenerator}, or
- *     {@link org.hibernate.tuple.ValueGenerator}, or
+ * <li>an {@link InDatabaseGenerator}, for values which are generated by the
- * <li>an {@link InDatabaseGenerator}, for
+ *     database.
- *     values which are generated by the database.
  * </ul>
  * A generator annotation may have members, which are used to configure the
  * generation strategy, when the strategy instance in initialized via

hibernate-core/src/main/java/org/hibernate/collection/spi/PersistentIdentifierBag.java

@@ -23,6 +23,8 @@ import org.hibernate.metamodel.mapping.PluralAttributeMapping;
 import org.hibernate.persister.collection.CollectionPersister;
 import org.hibernate.type.Type;
 
+import static org.hibernate.generator.EventType.INSERT;
+
 /**
  * An {@code IdentifierBag} implements "bag" semantics more efficiently than
  * a regular {@code Bag} by adding a synthetic identifier column to the
@@ -368,7 +370,7 @@ public class PersistentIdentifierBag<E> extends AbstractPersistentCollection<E>
 			final Integer loc = i++;
 			if ( !identifiers.containsKey( loc ) ) {
 				//TODO: native ids
-				final Object id = persister.getGenerator().generate( getSession(), entry, null );
+				final Object id = persister.getGenerator().generate( getSession(), entry, null, INSERT );
 				identifiers.put( loc, id );
 			}
 		}

hibernate-core/src/main/java/org/hibernate/engine/internal/Versioning.java

@@ -6,6 +6,7 @@
  */
 package org.hibernate.engine.internal;
 
+import org.hibernate.Remove;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.internal.CoreMessageLogger;
 import org.hibernate.metamodel.mapping.EntityVersionMapping;
@@ -14,6 +15,9 @@ import org.hibernate.type.descriptor.java.VersionJavaType;
 
 import org.jboss.logging.Logger;
 
+import static org.hibernate.generator.EventType.INSERT;
+import static org.hibernate.generator.EventType.UPDATE;
+
 /**
  * Utilities for dealing with optimistic locking values.
  *
@@ -39,7 +43,7 @@ public final class Versioning {
 	 * @param session The originating session
 	 * @return The initial optimistic locking value
 	 */
-	private static Object seed(EntityVersionMapping versionMapping, SharedSessionContractImplementor session) {
+	public static Object seed(EntityVersionMapping versionMapping, SharedSessionContractImplementor session) {
 		final Object seed = versionMapping.getJavaType().seed(
 				versionMapping.getLength(),
 				versionMapping.getPrecision(),
@@ -50,10 +54,40 @@ public final class Versioning {
 		return seed;
 	}
 
+
+	/**
+	 * Create an initial optimistic locking value using the for the version property
+	 * <em>if required</em> using the {@link org.hibernate.generator.Generator} contract
+	 * and inject it into the snapshot state.
+	 *
+	 * @param fields The current snapshot state
+	 * @param persister The persister of the versioned entity
+	 * @param entity The entity instance
+	 * @param session The originating session
+	 * @return True if we injected a new version value into the fields array; false
+	 * otherwise.
+	 */
+	public static boolean seedVersion(
+			Object entity,
+			Object[] fields,
+			EntityPersister persister,
+			SharedSessionContractImplementor session) {
+		final int versionProperty = persister.getVersionProperty();
+		final Object initialVersion = fields[versionProperty];
+		if ( isNullInitialVersion( initialVersion ) ) {
+			fields[versionProperty] = persister.getVersionGenerator().generate( session, entity, initialVersion, INSERT );
+			return true;
+		}
+		else {
+			LOG.tracev( "Using initial version: {0}", initialVersion );
+			return false;
+		}
+	}
+
 	/**
 	 * Create an initial optimistic locking value according the {@link VersionJavaType}
-	 * contract for the version property <b>if required</b> and inject it into
+	 * contract for the version property <em>if required</em> and inject it into the
-	 * the snapshot state.
+	 * snapshot state.
 	 *
 	 * @param fields The current snapshot state
 	 * @param versionProperty The index of the version property
@@ -61,28 +95,60 @@ public final class Versioning {
 	 * @param session The originating session
 	 * @return True if we injected a new version value into the fields array; false
 	 * otherwise.
+	 *
+	 * @deprecated Use {@link #seedVersion(Object, Object[], EntityPersister, SharedSessionContractImplementor)}
 	 */
+	@Deprecated(since = "6.2") @Remove
 	public static boolean seedVersion(
 			Object[] fields,
 			int versionProperty,
 			EntityVersionMapping versionMapping,
 			SharedSessionContractImplementor session) {
 		final Object initialVersion = fields[versionProperty];
-		if (
+		if ( isNullInitialVersion( initialVersion ) ) {
-			initialVersion==null ||
-			// This next bit is to allow for both unsaved-value="negative"
-			// and for "older" behavior where version number did not get
-			// seeded if it was already set in the object
-			// TODO: shift it into unsaved-value strategy
-			( (initialVersion instanceof Number) && ( (Number) initialVersion ).longValue()<0 )
-		) {
 			fields[versionProperty] = seed( versionMapping, session );
 			return true;
 		}
+		else {
 			LOG.tracev( "Using initial version: {0}", initialVersion );
 			return false;
 		}
+	}
 
+	/**
+	 * Determines if the value of the assigned  version property should be considered
+	 * a "null" value, that is, if it is literally {@code null}, or if it is a negative
+	 * integer.
+	 *
+	 * @param initialVersion The value initially assigned to a version property
+	 * @return {@code} if the value shoudl be considered null for this purpose
+	 */
+	public static boolean isNullInitialVersion(Object initialVersion) {
+		return initialVersion == null
+			||  // This next bit is to allow for both unsaved-value="negative"
+				// and for "older" behavior where version number did not get
+				// seeded if it was already set in the object
+				// TODO: shift it into unsaved-value strategy
+				initialVersion instanceof Number && ((Number) initialVersion).longValue() < 0;
+	}
+
+	/**
+	 * Generate the next increment in the optimistic locking value according the
+	 * {@link org.hibernate.generator.Generator} contract for the version property.
+	 *
+	 * @param entity The entity instance
+	 * @param currentVersion The current version
+	 * @param persister The persister of the versioned entity
+	 * @param session The originating session
+	 * @return The incremented optimistic locking value.
+	 */
+	public static Object incrementVersion(
+			Object entity,
+			Object currentVersion,
+			EntityPersister persister,
+			SharedSessionContractImplementor session) {
+		return persister.getVersionGenerator().generate( session, entity, currentVersion, UPDATE );
+	}
 
 	/**
 	 * Generate the next increment in the optimistic locking value according
@@ -121,11 +187,10 @@ public final class Versioning {
 	 * @param persister The entity persister
 	 */
 	public static void setVersion(Object[] fields, Object version, EntityPersister persister) {
-		if ( !persister.isVersioned() ) {
+		if ( persister.isVersioned() ) {
-			return;
-		}
 			fields[ persister.getVersionProperty() ] = version;
 		}
+	}
 
 	/**
 	 * Extract the optimistic locking value out of the entity state snapshot.
@@ -135,10 +200,7 @@ public final class Versioning {
 	 * @return The extracted optimistic locking value
 	 */
 	public static Object getVersion(Object[] fields, EntityPersister persister) {
-		if ( !persister.isVersioned() ) {
+		return persister.isVersioned() ? fields[persister.getVersionProperty()] : null;
-			return null;
-		}
-		return fields[ persister.getVersionProperty() ];
 	}
 
 	/**

hibernate-core/src/main/java/org/hibernate/event/internal/AbstractReassociateEventListener.java

@@ -7,7 +7,6 @@
 package org.hibernate.event.internal;
 
 import org.hibernate.LockMode;
-import org.hibernate.engine.internal.Versioning;
 import org.hibernate.engine.spi.EntityEntry;
 import org.hibernate.engine.spi.EntityKey;
 import org.hibernate.engine.spi.PersistenceContext;
@@ -21,6 +20,8 @@ import org.hibernate.type.TypeHelper;
 
 import org.jboss.logging.Logger;
 
+import static org.hibernate.engine.internal.Versioning.getVersion;
+
 /**
  * A convenience base class for listeners that respond to requests to reassociate an entity
  * to a session ( such as through lock() or update() ).
@@ -65,7 +66,7 @@ public abstract class AbstractReassociateEventListener {
 				values,
 				source
 		);
-		Object version = Versioning.getVersion( values, persister );
+		Object version = getVersion( values, persister );
 
 		EntityEntry newEntry = persistenceContext.addEntity(
 				object,

hibernate-core/src/main/java/org/hibernate/event/internal/AbstractSaveEventListener.java

@@ -16,7 +16,6 @@ import org.hibernate.action.internal.EntityInsertAction;
 import org.hibernate.classic.Lifecycle;
 import org.hibernate.engine.internal.Cascade;
 import org.hibernate.engine.internal.CascadePoint;
-import org.hibernate.engine.internal.Versioning;
 import org.hibernate.engine.spi.CascadingAction;
 import org.hibernate.engine.spi.EntityEntry;
 import org.hibernate.engine.spi.EntityEntryExtraState;
@@ -27,7 +26,6 @@ import org.hibernate.engine.spi.SessionImplementor;
 import org.hibernate.engine.spi.Status;
 import org.hibernate.event.spi.EventSource;
 import org.hibernate.id.IdentifierGenerationException;
-import org.hibernate.id.IdentifierGeneratorHelper;
 import org.hibernate.internal.CoreLogging;
 import org.hibernate.internal.CoreMessageLogger;
 import org.hibernate.jpa.event.spi.CallbackRegistry;
@@ -40,6 +38,10 @@ import org.hibernate.type.Type;
 import org.hibernate.type.TypeHelper;
 
 import static org.hibernate.engine.internal.ManagedTypeHelper.processIfSelfDirtinessTracker;
+import static org.hibernate.engine.internal.Versioning.getVersion;
+import static org.hibernate.engine.internal.Versioning.seedVersion;
+import static org.hibernate.generator.EventType.INSERT;
+import static org.hibernate.id.IdentifierGeneratorHelper.SHORT_CIRCUIT_INDICATOR;
 
 /**
  * A convenience base class for listeners responding to save events.
@@ -115,11 +117,11 @@ public abstract class AbstractSaveEventListener<C>
 		final EntityPersister persister = source.getEntityPersister( entityName, entity );
 		Generator generator = persister.getGenerator();
 		if ( !generator.generatedByDatabase() ) {
-			Object generatedId = ( (InMemoryGenerator) generator ).generate( source, entity, null );
+			final Object generatedId = ( (InMemoryGenerator) generator ).generate( source, entity, null, INSERT );
 			if ( generatedId == null ) {
 				throw new IdentifierGenerationException( "null id generated for: " + entity.getClass() );
 			}
-			else if ( generatedId == IdentifierGeneratorHelper.SHORT_CIRCUIT_INDICATOR ) {
+			else if ( generatedId == SHORT_CIRCUIT_INDICATOR ) {
 				return source.getIdentifier( entity );
 			}
 			else {
@@ -188,7 +190,7 @@ public abstract class AbstractSaveEventListener<C>
 	}
 
 	private static EntityKey entityKey(Object entity, Object id, EntityPersister persister, boolean useIdentityColumn, EventSource source) {
-		if ( !useIdentityColumn) {
+		if ( !useIdentityColumn ) {
 			final EntityKey key = source.generateEntityKey( id, persister );
 			final PersistenceContext persistenceContext = source.getPersistenceContextInternal();
 			final Object old = persistenceContext.getEntity( key );
@@ -316,16 +318,16 @@ public abstract class AbstractSaveEventListener<C>
 	}
 
 	private Object[] cloneAndSubstituteValues(Object entity, EntityPersister persister, C context, EventSource source, Object id) {
-		Object[] values = persister.getPropertyValuesToInsert(entity, getMergeMap(context), source);
+		Object[] values = persister.getPropertyValuesToInsert( entity, getMergeMap(context), source );
 		Type[] types = persister.getPropertyTypes();
 
-		boolean substitute = substituteValuesIfNecessary(entity, id, values, persister, source);
+		boolean substitute = substituteValuesIfNecessary( entity, id, values, persister, source );
 		if ( persister.hasCollections() ) {
-			substitute = visitCollectionsBeforeSave(entity, id, values, types, source) || substitute;
+			substitute = visitCollectionsBeforeSave( entity, id, values, types, source ) || substitute;
 		}
 
 		if ( substitute ) {
-			persister.setValues(entity, values );
+			persister.setValues( entity, values );
 		}
 
 		TypeHelper.deepCopy(
@@ -363,7 +365,7 @@ public abstract class AbstractSaveEventListener<C>
 					id,
 					values,
 					entity,
-					Versioning.getVersion( values, persister ),
+					getVersion( values, persister ),
 					persister,
 					isVersionIncrementDisabled(),
 					source
@@ -429,12 +431,7 @@ public abstract class AbstractSaveEventListener<C>
 
 		//keep the existing version number in the case of replicate!
 		if ( persister.isVersioned() ) {
-			substitute = Versioning.seedVersion(
+			substitute = seedVersion( entity, values, persister, source ) || substitute;
-					values,
-					persister.getVersionProperty(),
-					persister.getVersionMapping(),
-					source
-			) || substitute;
 		}
 		return substitute;
 	}

hibernate-core/src/main/java/org/hibernate/event/internal/DefaultFlushEntityEventListener.java

@@ -44,6 +44,9 @@ import static org.hibernate.engine.internal.ManagedTypeHelper.asSelfDirtinessTra
 import static org.hibernate.engine.internal.ManagedTypeHelper.isPersistentAttributeInterceptable;
 import static org.hibernate.engine.internal.ManagedTypeHelper.isSelfDirtinessTracker;
 import static org.hibernate.engine.internal.ManagedTypeHelper.processIfSelfDirtinessTracker;
+import static org.hibernate.engine.internal.Versioning.getVersion;
+import static org.hibernate.engine.internal.Versioning.incrementVersion;
+import static org.hibernate.engine.internal.Versioning.setVersion;
 
 /**
  * An event that occurs for each entity instance at flush time
@@ -381,13 +384,13 @@ public class DefaultFlushEntityEventListener implements FlushEntityEventListener
 		if ( persister.isVersioned() ) {
 			Object[] values = event.getPropertyValues();
 			if ( entry.isBeingReplicated() ) {
-				return Versioning.getVersion( values, persister );
+				return getVersion( values, persister );
 			}
 			else {
 				final Object nextVersion = isVersionIncrementRequired( event, entry )
-						? Versioning.increment( entry.getVersion(), persister.getVersionMapping(), event.getSession() )
+						? incrementVersion( event.getEntity(), entry.getVersion(), persister, event.getSession() )
 						: entry.getVersion(); //use the current version
-				Versioning.setVersion( values, nextVersion, persister );
+				setVersion( values, nextVersion, persister );
 				return nextVersion;
 			}
 		}
@@ -397,7 +400,7 @@ public class DefaultFlushEntityEventListener implements FlushEntityEventListener
 
 	}
 
-	private boolean isVersionIncrementRequired(FlushEntityEvent event, EntityEntry entry) {
+	private static boolean isVersionIncrementRequired(FlushEntityEvent event, EntityEntry entry) {
 		if ( entry.getStatus() == Status.DELETED ) {
 			return false;
 		}

hibernate-core/src/main/java/org/hibernate/generator/EventType.java

@@ -24,6 +24,18 @@ package org.hibernate.generator;
  * @see EventTypeSets
  */
 public enum EventType {
+	/**
+	 * An event that occurs when any {@code insert} statements needed
+	 * to persist a new entity instance are executed. This indicates,
+	 * for example, that a surrogate primary key should be generated,
+	 * or initial that an initial version number should be seeded.
+	 */
 	INSERT,
+	/**
+	 * An event that occurs when any {@code update} statements needed
+	 * to persist changes to a dirty entity instance are executed.
+	 * This indicates, for example, that a version number should be
+	 * incremented.
+	 */
 	UPDATE;
 }

hibernate-core/src/main/java/org/hibernate/generator/Generator.java

@@ -22,7 +22,7 @@ import static org.hibernate.generator.EventType.UPDATE;
  * generated in Java code, or by the database.
  * <ul>
  * <li>Value generation via arbitrary code written in Java is the responsibility of the method
- *     {@link InMemoryGenerator#generate(SharedSessionContractImplementor, Object, Object)}.
+ *     {@link InMemoryGenerator#generate(SharedSessionContractImplementor, Object, Object, EventType)}.
  *	   In this case, the generated value is written to the database just like any other field
  *	   or property value.
  * <li>A value generated by the database might be generated implicitly, by a trigger, or using
@@ -45,11 +45,20 @@ import static org.hibernate.generator.EventType.UPDATE;
  * A generator must implement {@link #getEventTypes()} to specify the events for which it should be
  * called to produce a new value. {@link EventTypeSets} provides a convenient list of possibilities.
  * <p>
+ * There are two especially important applications of this machinery:
+ * <ul>
+ * <li>
  * An {@linkplain jakarta.persistence.Id identifier} generator is a generator capable of producing
  * surrogate primary key values. An identifier generator must respond to insert events only. That
  * is, {@link #getEventTypes()} must return {@link EventTypeSets#INSERT_ONLY}. It may be integrated
  * using the {@link org.hibernate.annotations.IdGeneratorType} meta-annotation or the older-style
  * {@link org.hibernate.annotations.GenericGenerator} annotation.
+ * <li>
+ * A {@linkplain jakarta.persistence.Version version} generator is a generator capable of seeding
+ * and incrementing version numbers. A version generator must respond to both insert and update
+ * events. That is, {@link #getEventTypes()} must return {@link EventTypeSets#INSERT_AND_UPDATE}.
+ * It may be integrated using {@link org.hibernate.annotations.ValueGenerationType} meta-annotation.
+ * </ul>
  *
  * @see org.hibernate.annotations.ValueGenerationType
  * @see org.hibernate.annotations.IdGeneratorType

hibernate-core/src/main/java/org/hibernate/generator/InMemoryGenerator.java

@@ -40,10 +40,10 @@ public interface InMemoryGenerator extends Generator {
 	 * @param session      The session from which the request originates.
 	 * @param owner        The instance of the object owning the attribute for which we are generating a value.
 	 * @param currentValue The current value assigned to the property, or {@code null}
-	 *
+	 * @param eventType    The type of event that has triggered generation of a new value
 	 * @return The generated value
 	 */
-	Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue);
+	Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue, EventType eventType);
 
 	default boolean generatedByDatabase() {
 		return false;

hibernate-core/src/main/java/org/hibernate/generator/internal/CurrentTimestampGeneration.java

@@ -91,7 +91,7 @@ public class CurrentTimestampGeneration implements InMemoryGenerator, InDatabase
 	}
 
 	@Override
-	public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue) {
+	public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue, EventType eventType) {
 		return generator.generateValue( (Session) session, owner, currentValue );
 	}
 

hibernate-core/src/main/java/org/hibernate/generator/internal/SourceGeneration.java

@@ -89,7 +89,7 @@ public class SourceGeneration implements InMemoryGenerator {
 	}
 
 	@Override
-	public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue) {
+	public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue, EventType eventType) {
 		return valueGenerator.generateValue( (Session) session, owner, currentValue );
 	}
 

hibernate-core/src/main/java/org/hibernate/generator/internal/TenantIdGeneration.java

@@ -51,7 +51,7 @@ public class TenantIdGeneration implements InMemoryGenerator {
 	}
 
 	@Override
-	public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue) {
+	public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue, EventType eventType) {
 		SessionFactoryImplementor sessionFactory = session.getSessionFactory();
 		JavaType<Object> descriptor = sessionFactory.getTypeConfiguration().getJavaTypeRegistry()
 				.findDescriptor(propertyType);

hibernate-core/src/main/java/org/hibernate/generator/internal/VersionGeneration.java

@@ -0,0 +1,52 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.generator.internal;
+
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.generator.EventType;
+import org.hibernate.generator.InMemoryGenerator;
+import org.hibernate.metamodel.mapping.EntityVersionMapping;
+
+import java.util.EnumSet;
+
+import static org.hibernate.engine.internal.Versioning.increment;
+import static org.hibernate.engine.internal.Versioning.seed;
+import static org.hibernate.generator.EventType.INSERT;
+import static org.hibernate.generator.EventTypeSets.INSERT_AND_UPDATE;
+
+/**
+ * A default {@link org.hibernate.generator.Generator} for {@link jakarta.persistence.Version @Version}
+ * properties. This implementation simply delegates back to:
+ * <ul>
+ * <li>{@link org.hibernate.type.descriptor.java.VersionJavaType#seed} to seed an initial version, and
+ * <li>{@link org.hibernate.type.descriptor.java.VersionJavaType#next} to increment a version.
+ * </ul>
+ * Thus, this implementation reproduces the "classic" behavior of Hibernate. A custom generator specified
+ * using a {@linkplain org.hibernate.annotations.ValueGenerationType generator annotation} will override
+ * this implementation, allowing customized versioning.
+ *
+ * @author Gavin King
+ */
+public class VersionGeneration implements InMemoryGenerator {
+	private final EntityVersionMapping versionMapping;
+
+	public VersionGeneration(EntityVersionMapping versionMapping) {
+		this.versionMapping = versionMapping;
+	}
+
+	@Override
+	public EnumSet<EventType> getEventTypes() {
+		return INSERT_AND_UPDATE;
+	}
+
+	@Override
+	public Object generate(SharedSessionContractImplementor session, Object owner, Object current, EventType eventType) {
+		return eventType == INSERT
+				? seed( versionMapping, session )
+				: increment( current, versionMapping, session );
+	}
+}

hibernate-core/src/main/java/org/hibernate/id/IdentifierGenerator.java

@@ -142,7 +142,7 @@ public interface IdentifierGenerator extends InMemoryGenerator, ExportableProduc
 	 * The {@code currentValue} is usually null for id generation.
 	 */
 	@Override
-	default Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue) {
+	default Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue, EventType eventType) {
 		return generate( session, owner );
 	}
 

hibernate-core/src/main/java/org/hibernate/id/uuid/UuidGenerator.java

@@ -72,7 +72,7 @@ public class UuidGenerator implements InMemoryGenerator {
 	}
 
 	@Override
-	public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue) {
+	public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue, EventType eventType) {
 		return valueTransformer.transform( generator.generateUuid( session ) );
 	}
 }

hibernate-core/src/main/java/org/hibernate/internal/StatelessSessionImpl.java

@@ -20,7 +20,6 @@ import org.hibernate.bytecode.spi.BytecodeEnhancementMetadata;
 import org.hibernate.cache.spi.access.EntityDataAccess;
 import org.hibernate.collection.spi.PersistentCollection;
 import org.hibernate.engine.internal.StatefulPersistenceContext;
-import org.hibernate.engine.internal.Versioning;
 import org.hibernate.engine.spi.EntityKey;
 import org.hibernate.engine.spi.LoadQueryInfluencers;
 import org.hibernate.engine.spi.PersistenceContext;
@@ -41,6 +40,10 @@ import jakarta.transaction.SystemException;
 
 import static org.hibernate.engine.internal.ManagedTypeHelper.asPersistentAttributeInterceptable;
 import static org.hibernate.engine.internal.ManagedTypeHelper.isPersistentAttributeInterceptable;
+import static org.hibernate.engine.internal.Versioning.incrementVersion;
+import static org.hibernate.engine.internal.Versioning.seedVersion;
+import static org.hibernate.engine.internal.Versioning.setVersion;
+import static org.hibernate.generator.EventType.INSERT;
 
 /**
  * Concrete implementation of the {@link StatelessSession} API.
@@ -97,17 +100,11 @@ public class StatelessSessionImpl extends AbstractSharedSessionContract implemen
 		final EntityPersister persister = getEntityPersister( entityName, entity );
 		final Object id;
 		final Object[] state = persister.getValues( entity );
-		Generator generator = persister.getGenerator();
+		final Generator generator = persister.getGenerator();
 		if ( !generator.generatedByDatabase() ) {
-			id = ( (InMemoryGenerator) generator).generate( this, entity, null );
+			id = ( (InMemoryGenerator) generator).generate( this, entity, null, INSERT );
 			if ( persister.isVersioned() ) {
-				boolean substitute = Versioning.seedVersion(
+				if ( seedVersion( entity, state, persister, this ) ) {
-						state,
-						persister.getVersionProperty(),
-						persister.getVersionMapping(),
-						this
-				);
-				if ( substitute ) {
 					persister.setValues( entity, state );
 				}
 			}
@@ -156,8 +153,8 @@ public class StatelessSessionImpl extends AbstractSharedSessionContract implemen
 		Object oldVersion;
 		if ( persister.isVersioned() ) {
 			oldVersion = persister.getVersion( entity );
-			Object newVersion = Versioning.increment( oldVersion, persister.getVersionMapping(), this );
+			Object newVersion = incrementVersion( entity, oldVersion, persister, this );
-			Versioning.setVersion( state, newVersion, persister );
+			setVersion( state, newVersion, persister );
 			persister.setValues( entity, state );
 		}
 		else {

hibernate-core/src/main/java/org/hibernate/loader/entity/CacheEntityLoaderHelper.java

@@ -18,7 +18,6 @@ import org.hibernate.cache.spi.entry.StandardCacheEntryImpl;
 import org.hibernate.engine.internal.CacheHelper;
 import org.hibernate.engine.internal.StatefulPersistenceContext;
 import org.hibernate.engine.internal.TwoPhaseLoad;
-import org.hibernate.engine.internal.Versioning;
 import org.hibernate.engine.spi.EntityEntry;
 import org.hibernate.engine.spi.EntityKey;
 import org.hibernate.engine.spi.PersistenceContext;
@@ -45,6 +44,7 @@ import org.hibernate.type.TypeHelper;
 import static org.hibernate.engine.internal.ManagedTypeHelper.asPersistentAttributeInterceptable;
 import static org.hibernate.engine.internal.ManagedTypeHelper.isManagedEntity;
 import static org.hibernate.engine.internal.ManagedTypeHelper.isPersistentAttributeInterceptable;
+import static org.hibernate.engine.internal.Versioning.getVersion;
 import static org.hibernate.loader.ast.internal.LoaderHelper.upgradeLock;
 
 /**
@@ -424,7 +424,7 @@ public class CacheEntityLoaderHelper {
 					source
 			);
 		}
-		version = Versioning.getVersion( values, subclassPersister );
+		version = getVersion( values, subclassPersister );
 		LOG.tracef( "Cached Version : %s", version );
 
 		final Object proxy = persistenceContext.getProxy( entityKey );

hibernate-core/src/main/java/org/hibernate/mapping/Component.java

@@ -28,7 +28,6 @@ import org.hibernate.dialect.Dialect;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.id.CompositeNestedGeneratedValueGenerator;
 import org.hibernate.id.IdentifierGenerator;
-import org.hibernate.id.IdentifierGeneratorHelper;
 import org.hibernate.id.factory.IdentifierGeneratorFactory;
 import org.hibernate.internal.util.ReflectHelper;
 import org.hibernate.internal.util.collections.ArrayHelper;
@@ -41,6 +40,9 @@ import org.hibernate.type.ComponentType;
 import org.hibernate.type.EmbeddedComponentType;
 import org.hibernate.type.Type;
 
+import static org.hibernate.generator.EventType.INSERT;
+import static org.hibernate.id.IdentifierGeneratorHelper.POST_INSERT_INDICATOR;
+
 /**
  * A mapping model object that represents an {@linkplain jakarta.persistence.Embeddable embeddable class}.
  * <p>
@@ -508,38 +510,36 @@ public class Component extends SimpleValue implements MetaAttributable, Sortable
 	}
 
 	public static class ValueGenerationPlan implements CompositeNestedGeneratedValueGenerator.GenerationPlan {
-		private final Generator subGenerator;
+		private final Generator subgenerator;
 		private final Setter injector;
 
-		public ValueGenerationPlan(
+		public ValueGenerationPlan(Generator subgenerator, Setter injector) {
-				Generator subGenerator,
+			this.subgenerator = subgenerator;
-				Setter injector) {
-			this.subGenerator = subGenerator;
 			this.injector = injector;
 		}
 
 		@Override
 		public void execute(SharedSessionContractImplementor session, Object incomingObject, Object injectionContext) {
-			if ( !subGenerator.generatedByDatabase() ) {
+			if ( !subgenerator.generatedByDatabase() ) {
-				Object generatedId = ( (InMemoryGenerator) subGenerator ).generate( session, incomingObject, null );
+				Object generatedId = ( (InMemoryGenerator) subgenerator).generate( session, incomingObject, null, INSERT );
 				injector.set( injectionContext, generatedId );
 			}
 			else {
-				injector.set( injectionContext, IdentifierGeneratorHelper.POST_INSERT_INDICATOR );
+				injector.set( injectionContext, POST_INSERT_INDICATOR );
 			}
 		}
 
 		@Override
 		public void registerExportables(Database database) {
-			if ( subGenerator instanceof ExportableProducer ) {
+			if ( subgenerator instanceof ExportableProducer ) {
-				( (ExportableProducer) subGenerator ).registerExportables( database );
+				( (ExportableProducer) subgenerator).registerExportables( database );
 			}
 		}
 
 		@Override
 		public void initialize(SqlStringGenerationContext context) {
-			if ( subGenerator instanceof IdentifierGenerator ) {
+			if ( subgenerator instanceof IdentifierGenerator ) {
-				( (IdentifierGenerator) subGenerator ).initialize( context );
+				( (IdentifierGenerator) subgenerator).initialize( context );
 			}
 		}
 	}

hibernate-core/src/main/java/org/hibernate/metamodel/mapping/InDatabaseGeneratedValueResolver.java

@@ -8,7 +8,7 @@ package org.hibernate.metamodel.mapping;
 
 import org.hibernate.Internal;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
-import org.hibernate.tuple.GenerationTiming;
+import org.hibernate.generator.EventType;
 
 /**
  * GeneratedValueResolver impl for in-db generation.  It extracts the generated value
@@ -18,11 +18,11 @@ import org.hibernate.tuple.GenerationTiming;
  */
 @Internal
 public class InDatabaseGeneratedValueResolver implements GeneratedValueResolver {
-//	private final GenerationTiming timing;
+	private final EventType eventType;
 	private final int resultPosition;
 
-	public InDatabaseGeneratedValueResolver(GenerationTiming timing, int resultPosition) {
+	public InDatabaseGeneratedValueResolver(EventType eventType, int resultPosition) {
-//		this.timing = timing;
+		this.eventType = eventType;
 		this.resultPosition = resultPosition;
 	}
 

hibernate-core/src/main/java/org/hibernate/metamodel/mapping/InMemoryGeneratedValueResolver.java

@@ -8,7 +8,7 @@ package org.hibernate.metamodel.mapping;
 
 import org.hibernate.Internal;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
-import org.hibernate.tuple.GenerationTiming;
+import org.hibernate.generator.EventType;
 import org.hibernate.generator.InMemoryGenerator;
 
 /**
@@ -18,12 +18,12 @@ import org.hibernate.generator.InMemoryGenerator;
  */
 @Internal
 public class InMemoryGeneratedValueResolver implements GeneratedValueResolver {
-//	private final GenerationTiming generationTiming;
+	private final EventType eventType;
-	private final InMemoryGenerator valueGenerator;
+	private final InMemoryGenerator generator;
 
-	public InMemoryGeneratedValueResolver(InMemoryGenerator valueGenerator, GenerationTiming generationTiming) {
+	public InMemoryGeneratedValueResolver(InMemoryGenerator generator, EventType eventType) {
-		this.valueGenerator = valueGenerator;
+		this.generator = generator;
-//		this.generationTiming = generationTiming;
+		this.eventType = eventType;
 	}
 
 //	@Override
@@ -33,6 +33,6 @@ public class InMemoryGeneratedValueResolver implements GeneratedValueResolver {
 
 	@Override
 	public Object resolveGeneratedValue(Object[] row, Object entity, SharedSessionContractImplementor session, Object currentValue) {
-		return valueGenerator.generate( session, entity, currentValue );
+		return generator.generate( session, entity, currentValue, eventType );
 	}
 }

hibernate-core/src/main/java/org/hibernate/metamodel/mapping/internal/GeneratedValuesProcessor.java

@@ -14,6 +14,7 @@ import org.hibernate.LockOptions;
 import org.hibernate.engine.spi.LoadQueryInfluencers;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.generator.EventType;
 import org.hibernate.generator.InDatabaseGenerator;
 import org.hibernate.loader.ast.internal.LoaderSelectBuilder;
 import org.hibernate.metamodel.UnsupportedMappingException;
@@ -31,7 +32,6 @@ import org.hibernate.sql.exec.spi.Callback;
 import org.hibernate.sql.exec.spi.ExecutionContext;
 import org.hibernate.sql.exec.spi.JdbcOperationQuerySelect;
 import org.hibernate.sql.exec.spi.JdbcParameterBindings;
-import org.hibernate.tuple.GenerationTiming;
 import org.hibernate.generator.Generator;
 
 import static org.hibernate.sql.results.spi.ListResultsConsumer.UniqueSemantic.FILTER;
@@ -59,7 +59,7 @@ public class GeneratedValuesProcessor {
 
 	public GeneratedValuesProcessor(
 			EntityMappingType entityDescriptor,
-			GenerationTiming timing,
+			EventType timing,
 			SessionFactoryImplementor sessionFactory) {
 		this.entityDescriptor = entityDescriptor;
 		this.sessionFactory = sessionFactory;
@@ -88,7 +88,7 @@ public class GeneratedValuesProcessor {
 	 * populate the list of {@link GeneratedValueDescriptor}s by side effect, and
 	 * return a list of {@link AttributeMapping}s.
 	 */
-	private List<AttributeMapping> getGeneratedAttributes(EntityMappingType entityDescriptor, GenerationTiming timing) {
+	private List<AttributeMapping> getGeneratedAttributes(EntityMappingType entityDescriptor, EventType timing) {
 		// todo (6.0): For now, we rely on the entity metamodel as composite attributes report
 		//             GenerationTiming.NEVER even if they have attributes that would need generation
 		final Generator[] generators = entityDescriptor.getEntityPersister().getEntityMetamodel().getGenerators();

hibernate-core/src/main/java/org/hibernate/persister/entity/AbstractEntityPersister.java

@@ -93,6 +93,9 @@ import org.hibernate.engine.spi.SessionImplementor;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.event.spi.EventSource;
 import org.hibernate.event.spi.LoadEvent;
+import org.hibernate.generator.EventType;
+import org.hibernate.generator.InMemoryGenerator;
+import org.hibernate.generator.internal.VersionGeneration;
 import org.hibernate.id.Assigned;
 import org.hibernate.id.BulkInsertionCapableIdentifierGenerator;
 import org.hibernate.id.IdentifierGenerator;
@@ -259,7 +262,6 @@ import org.hibernate.sql.results.internal.SqlSelectionImpl;
 import org.hibernate.stat.spi.StatisticsImplementor;
 import org.hibernate.generator.Generator;
 import org.hibernate.generator.InDatabaseGenerator;
-import org.hibernate.tuple.GenerationTiming;
 import org.hibernate.tuple.NonIdentifierAttribute;
 import org.hibernate.tuple.entity.EntityBasedAssociationAttribute;
 import org.hibernate.tuple.entity.EntityMetamodel;
@@ -278,6 +280,8 @@ import static org.hibernate.engine.internal.ManagedTypeHelper.isPersistentAttrib
 import static org.hibernate.engine.internal.ManagedTypeHelper.processIfPersistentAttributeInterceptable;
 import static org.hibernate.engine.internal.ManagedTypeHelper.processIfSelfDirtinessTracker;
 import static org.hibernate.engine.internal.Versioning.isVersionIncrementRequired;
+import static org.hibernate.generator.EventType.INSERT;
+import static org.hibernate.generator.EventType.UPDATE;
 import static org.hibernate.sql.ast.spi.SqlExpressionResolver.createColumnReferenceKey;
 
 /**
@@ -414,7 +418,6 @@ public abstract class AbstractEntityPersister
 	private final Map<String,String[]> subclassPropertyAliases = new HashMap<>();
 	private final Map<String,String[]> subclassPropertyColumnNames = new HashMap<>();
 
-
 	private final JavaType<?> javaType;
 	private final EntityRepresentationStrategy representationStrategy;
 
@@ -431,6 +434,8 @@ public abstract class AbstractEntityPersister
 	protected Map<String, AttributeMapping> declaredAttributeMappings = new LinkedHashMap<>();
 	protected List<Fetchable> staticFetchableList;
 
+	private InMemoryGenerator versionGenerator;
+
 	protected ReflectionOptimizer.AccessOptimizer accessOptimizer;
 
 	/**
@@ -490,10 +495,10 @@ public abstract class AbstractEntityPersister
 
 		// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-		this.representationStrategy = creationContext.getBootstrapContext().getRepresentationStrategySelector()
+		representationStrategy = creationContext.getBootstrapContext().getRepresentationStrategySelector()
 				.resolveStrategy( bootDescriptor, this, creationContext );
 
-		this.javaType = representationStrategy.getLoadJavaType();
+		javaType = representationStrategy.getLoadJavaType();
 		assert javaType != null;
 
 		final JdbcServices jdbcServices = factory.getServiceRegistry().getService( JdbcServices.class );
@@ -1933,7 +1938,7 @@ public abstract class AbstractEntityPersister
 		return select.addCondition( rootTableKeyColumnNames, "=?" ).toStatementString();
 	}
 
-	private GeneratedValuesProcessor createGeneratedValuesProcessor(GenerationTiming timing) {
+	private GeneratedValuesProcessor createGeneratedValuesProcessor(EventType timing) {
 		return new GeneratedValuesProcessor( this, timing, getFactory() );
 	}
 
@@ -3992,6 +3997,11 @@ public abstract class AbstractEntityPersister
 		return entityMetamodel.getIdentifierProperty().getGenerator();
 	}
 
+	@Override
+	public InMemoryGenerator getVersionGenerator() {
+		return versionGenerator;
+	}
+
 	@Override
 	public String getRootEntityName() {
 		return entityMetamodel.getRootName();
@@ -4771,11 +4781,11 @@ public abstract class AbstractEntityPersister
 		if ( superMappingType != null ) {
 			( (InFlightEntityMappingType) superMappingType ).prepareMappingModel( creationProcess );
 			if ( shouldProcessSuperMapping() ) {
-				this.discriminatorMapping = superMappingType.getDiscriminatorMapping();
+				discriminatorMapping = superMappingType.getDiscriminatorMapping();
-				this.identifierMapping = superMappingType.getIdentifierMapping();
+				identifierMapping = superMappingType.getIdentifierMapping();
-				this.naturalIdMapping = superMappingType.getNaturalIdMapping();
+				naturalIdMapping = superMappingType.getNaturalIdMapping();
-				this.versionMapping = superMappingType.getVersionMapping();
+				versionMapping = superMappingType.getVersionMapping();
-				this.rowIdMapping = superMappingType.getRowIdMapping();
+				rowIdMapping = superMappingType.getRowIdMapping();
 			}
 			else {
 				prepareMappingModel( creationProcess, bootEntityDescriptor );
@@ -4787,10 +4797,17 @@ public abstract class AbstractEntityPersister
 //			rootEntityDescriptor = this;
 		}
 
-		final EntityMetamodel currentEntityMetamodel = this.getEntityMetamodel();
+		final EntityMetamodel currentEntityMetamodel = getEntityMetamodel();
+
+		if ( currentEntityMetamodel.isVersioned() ) {
+			final InMemoryGenerator generator = currentEntityMetamodel.getVersionGenerator();
+			// need to do this here because EntityMetamodel doesn't have the EntityVersionMapping :-(
+			versionGenerator = generator == null ? new VersionGeneration( versionMapping ) : generator;
+		}
+
 		int stateArrayPosition = getStateArrayInitialPosition( creationProcess );
 
-		NonIdentifierAttribute[] properties = currentEntityMetamodel.getProperties();
+		final NonIdentifierAttribute[] properties = currentEntityMetamodel.getProperties();
 		for ( int i = 0; i < currentEntityMetamodel.getPropertySpan(); i++ ) {
 			final NonIdentifierAttribute runtimeAttrDefinition = properties[i];
 			final Property bootProperty = bootEntityDescriptor.getProperty( runtimeAttrDefinition.getName() );
@@ -4826,7 +4843,6 @@ public abstract class AbstractEntityPersister
 		}
 
 
-
 		// register a callback for after all `#prepareMappingModel` calls have finished.  here we want to delay the
 		// generation of `staticFetchableList` because we need to wait until after all sub-classes have had their
 		// `#prepareMappingModel` called (and their declared attribute mappings resolved)
@@ -4834,10 +4850,10 @@ public abstract class AbstractEntityPersister
 				"Entity(" + getEntityName() + ") `staticFetchableList` generator",
 				() -> {
 					if ( hasInsertGeneratedProperties() ) {
-						insertGeneratedValuesProcessor = createGeneratedValuesProcessor( GenerationTiming.INSERT );
+						insertGeneratedValuesProcessor = createGeneratedValuesProcessor( INSERT );
 					}
 					if ( hasUpdateGeneratedProperties() ) {
-						updateGeneratedValuesProcessor = createGeneratedValuesProcessor( GenerationTiming.UPDATE );
+						updateGeneratedValuesProcessor = createGeneratedValuesProcessor( UPDATE );
 					}
 					staticFetchableList = new ArrayList<>( attributeMappings.size() );
 					visitSubTypeAttributeMappings( attributeMapping -> staticFetchableList.add( attributeMapping ) );
@@ -4921,8 +4937,7 @@ public abstract class AbstractEntityPersister
 
 		identifierMapping = creationProcess.processSubPart(
 				EntityIdentifierMapping.ROLE_LOCAL_NAME,
-				(role, process) ->
+				(role, process) -> generateIdentifierMapping( templateInstanceCreator, bootEntityDescriptor, process )
-						generateIdentifierMapping( templateInstanceCreator, bootEntityDescriptor, process )
 		);
 
 		versionMapping = generateVersionMapping( templateInstanceCreator, bootEntityDescriptor, creationProcess );

hibernate-core/src/main/java/org/hibernate/persister/entity/EntityPersister.java

@@ -27,6 +27,8 @@ import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SessionImplementor;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.event.spi.EventSource;
+import org.hibernate.generator.InMemoryGenerator;
+import org.hibernate.generator.internal.VersionGeneration;
 import org.hibernate.id.IdentifierGenerator;
 import org.hibernate.id.insert.InsertGeneratedIdentifierDelegate;
 import org.hibernate.internal.FilterAliasGenerator;
@@ -464,6 +466,10 @@ public interface EntityPersister
 		return getIdentifierGenerator();
 	}
 
+	default InMemoryGenerator getVersionGenerator() {
+		return new VersionGeneration( getVersionMapping() );
+	}
+
 	@Override
 	default AttributeMapping getAttributeMapping(int position) {
 		return getAttributeMappings().get( position );

hibernate-core/src/main/java/org/hibernate/persister/entity/mutation/InsertCoordinator.java

@@ -19,6 +19,7 @@ import org.hibernate.engine.jdbc.mutation.TableInclusionChecker;
 import org.hibernate.engine.jdbc.mutation.spi.MutationExecutorService;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.generator.EventType;
 import org.hibernate.id.insert.InsertGeneratedIdentifierDelegate;
 import org.hibernate.metamodel.mapping.AttributeMapping;
 import org.hibernate.metamodel.mapping.BasicEntityIdentifierMapping;
@@ -103,11 +104,11 @@ public class InsertCoordinator extends AbstractMutationCoordinator {
 		if ( entityMetamodel.hasPreInsertGeneratedValues() ) {
 			final Generator[] generators = entityMetamodel.getGenerators();
 			for ( int i = 0; i < generators.length; i++ ) {
-				Generator generator = generators[i];
+				final Generator generator = generators[i];
 				if ( generator != null
 						&& !generator.generatedByDatabase()
 						&& generator.generatesOnInsert() ) {
-					values[i] = ( (InMemoryGenerator) generator ).generate( session, entity, values[i] );
+					values[i] = ( (InMemoryGenerator) generator ).generate( session, entity, values[i], EventType.INSERT );
 					entityPersister().setPropertyValue( entity, i, values[i] );
 				}
 			}

hibernate-core/src/main/java/org/hibernate/persister/entity/mutation/UpdateCoordinatorStandard.java

@@ -60,6 +60,7 @@ import static org.hibernate.engine.OptimisticLockStyle.DIRTY;
 import static org.hibernate.engine.OptimisticLockStyle.NONE;
 import static org.hibernate.engine.OptimisticLockStyle.VERSION;
 import static org.hibernate.engine.internal.Versioning.isVersionIncrementRequired;
+import static org.hibernate.generator.EventType.UPDATE;
 import static org.hibernate.internal.util.collections.ArrayHelper.EMPTY_INT_ARRAY;
 
 /**
@@ -452,7 +453,7 @@ public class UpdateCoordinatorStandard extends AbstractMutationCoordinator imple
 				if ( generator != null
 						&& !generator.generatedByDatabase()
 						&& generator.generatesOnUpdate() ) {
-					newValues[i] = ( (InMemoryGenerator) generator ).generate( session, object, newValues[i] );
+					newValues[i] = ( (InMemoryGenerator) generator ).generate( session, object, newValues[i], UPDATE );
 					entityPersister().setPropertyValue( object, i, newValues[i] );
 					fieldsPreUpdateNeeded[count++] = i;
 				}

hibernate-core/src/main/java/org/hibernate/query/sqm/mutation/internal/temptable/InsertExecutionDelegate.java

@@ -22,6 +22,7 @@ import org.hibernate.engine.FetchTiming;
 import org.hibernate.engine.jdbc.spi.JdbcServices;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.generator.EventType;
 import org.hibernate.id.BulkInsertionCapableIdentifierGenerator;
 import org.hibernate.id.OptimizableGenerator;
 import org.hibernate.id.enhanced.Optimizer;
@@ -508,7 +509,7 @@ public class InsertExecutionDelegate implements TableBasedInsertHandler.Executio
 							rootIdentity,
 							new JdbcParameterBindingImpl(
 									identifierMapping.getJdbcMapping(),
-									( (InMemoryGenerator) generator ).generate( executionContext.getSession(), null, null )
+									( (InMemoryGenerator) generator ).generate( executionContext.getSession(), null, null, EventType.INSERT )
 							)
 					);
 					jdbcServices.getJdbcMutationExecutor().execute(

hibernate-core/src/main/java/org/hibernate/query/sqm/sql/BaseSqmToSqlAstConverter.java

@@ -404,6 +404,7 @@ import jakarta.persistence.TemporalType;
 import jakarta.persistence.metamodel.SingularAttribute;
 import jakarta.persistence.metamodel.Type;
 
+import static org.hibernate.generator.EventType.INSERT;
 import static org.hibernate.internal.util.NullnessHelper.coalesceSuppliedValues;
 import static org.hibernate.query.sqm.BinaryArithmeticOperator.ADD;
 import static org.hibernate.query.sqm.BinaryArithmeticOperator.MULTIPLY;
@@ -1464,7 +1465,7 @@ public abstract class BaseSqmToSqlAstConverter<T extends Statement> extends Base
 				ExecutionContext executionContext) throws SQLException {
 			getJdbcMapping().getJdbcValueBinder().bind(
 					statement,
-					generator.generate( executionContext.getSession(), null, null ),
+					generator.generate( executionContext.getSession(), null, null, INSERT ),
 					startPosition,
 					executionContext.getSession()
 			);

hibernate-core/src/main/java/org/hibernate/tuple/ValueGeneration.java

@@ -55,7 +55,7 @@ public interface ValueGeneration extends InMemoryGenerator, InDatabaseGenerator
 	ValueGenerator<?> getValueGenerator();
 
 	@Override
-	default Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue) {
+	default Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue, EventType eventType) {
 		return getValueGenerator().generateValue( (Session) session, owner, currentValue );
 	}
 

hibernate-core/src/main/java/org/hibernate/tuple/VmValueGeneration.java

@@ -51,7 +51,7 @@ public class VmValueGeneration implements InMemoryGenerator {
 	}
 
 	@Override
-	public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue) {
+	public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue, EventType eventType) {
 		return generator.generateValue( (Session) session, owner, currentValue );
 	}
 }

hibernate-core/src/main/java/org/hibernate/tuple/entity/EntityMetamodel.java

@@ -139,6 +139,8 @@ public class EntityMetamodel implements Serializable {
 	private final Set<String> subclassEntityNames;
 	private final Map<Class<?>,String> entityNameByInheritanceClassMap;
 
+	private final InMemoryGenerator versionGenerator;
+
 	private final BytecodeEnhancementMetadata bytecodeEnhancementMetadata;
 
 	@Deprecated(since = "6.0")
@@ -217,7 +219,7 @@ public class EntityMetamodel implements Serializable {
 		// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 		// generated value strategies ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-		this.generators = new Generator[propertySpan];
+		generators = new Generator[propertySpan];
 
 		boolean foundPreInsertGeneratedValues = false;
 		boolean foundPreUpdateGeneratedValues = false;
@@ -233,6 +235,7 @@ public class EntityMetamodel implements Serializable {
 		BitSet mutableIndexes = new BitSet();
 		boolean foundNonIdentifierPropertyNamedId = false;
 		boolean foundUpdateableNaturalIdProperty = false;
+		InMemoryGenerator tempVersionGenerator = null;
 
 		List<Property> props = persistentClass.getPropertyClosure();
 		for ( int i=0; i<props.size(); i++ ) {
@@ -298,16 +301,24 @@ public class EntityMetamodel implements Serializable {
 			propertyInsertability[i] = attribute.isInsertable();
 			propertyVersionability[i] = attribute.isVersionable();
 			nonlazyPropertyUpdateability[i] = attribute.isUpdateable() && !lazy;
-			propertyCheckability[i] = propertyUpdateability[i] ||
+			propertyCheckability[i] = propertyUpdateability[i]
-					( propertyType.isAssociationType() && ( (AssociationType) propertyType ).isAlwaysDirtyChecked() );
+					|| propertyType.isAssociationType() && ( (AssociationType) propertyType ).isAlwaysDirtyChecked();
 
 			cascadeStyles[i] = attribute.getCascadeStyle();
 			// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 			// generated value strategies ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 			final Generator generator = buildGenerator( property, creationContext );
-			generators[i] = generator;
 			if ( generator != null ) {
+				if ( i == tempVersionProperty && !generator.generatedByDatabase() ) {
+					// when we have an in-memory generator for the version, we
+					// want to plug it in to the older infrastructure specific
+					// to version generation, instead of treating it like a
+					// plain "value" generator for a regular attribute
+					tempVersionGenerator = (InMemoryGenerator) generator;
+				}
+				else {
+					generators[i] = generator;
 					if ( generatedWithNoParameter( generator ) ) {
 						propertyInsertability[i] = false;
 						propertyUpdateability[i] = false;
@@ -329,6 +340,7 @@ public class EntityMetamodel implements Serializable {
 						}
 					}
 				}
+			}
 
 			// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -369,17 +381,19 @@ public class EntityMetamodel implements Serializable {
 			hasCacheableNaturalId = persistentClass.getNaturalIdCacheRegionName() != null;
 		}
 
-		this.hasPreInsertGeneratedValues = foundPreInsertGeneratedValues;
+		hasPreInsertGeneratedValues = foundPreInsertGeneratedValues;
-		this.hasPreUpdateGeneratedValues = foundPreUpdateGeneratedValues;
+		hasPreUpdateGeneratedValues = foundPreUpdateGeneratedValues;
-		this.hasInsertGeneratedValues = foundPostInsertGeneratedValues;
+		hasInsertGeneratedValues = foundPostInsertGeneratedValues;
-		this.hasUpdateGeneratedValues = foundPostUpdateGeneratedValues;
+		hasUpdateGeneratedValues = foundPostUpdateGeneratedValues;
+
+		versionGenerator = tempVersionGenerator;
 
 		hasCascades = foundCascade;
 		hasCascadeDelete = foundCascadeDelete;
 		hasNonIdentifierPropertyNamedId = foundNonIdentifierPropertyNamedId;
 		versionPropertyIndex = tempVersionProperty;
 		hasLazyProperties = hasLazy;
-		if (hasLazyProperties) {
+		if ( hasLazyProperties ) {
 			LOG.lazyPropertyFetchingAvailable(name);
 		}
 
@@ -405,7 +419,8 @@ public class EntityMetamodel implements Serializable {
 		selectBeforeUpdate = persistentClass.hasSelectBeforeUpdate();
 
 		dynamicUpdate = persistentClass.useDynamicUpdate()
-				|| ( getBytecodeEnhancementMetadata().isEnhancedForLazyLoading() && getBytecodeEnhancementMetadata().getLazyAttributesMetadata().getFetchGroupNames().size() > 1 );
+				|| ( getBytecodeEnhancementMetadata().isEnhancedForLazyLoading()
+					&& getBytecodeEnhancementMetadata().getLazyAttributesMetadata().getFetchGroupNames().size() > 1 );
 		dynamicInsert = persistentClass.useDynamicInsert();
 
 		polymorphic = persistentClass.isPolymorphic();
@@ -477,6 +492,10 @@ public class EntityMetamodel implements Serializable {
 		return generators;
 	}
 
+	public InMemoryGenerator getVersionGenerator() {
+		return versionGenerator;
+	}
+
 	public static class ValueGenerationStrategyException extends HibernateException {
 		public ValueGenerationStrategyException(String message) {
 			super( message );

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/generated/temporals/GeneratedUuidTests.java

@@ -98,7 +98,7 @@ public class GeneratedUuidTests {
 		}
 
 		@Override
-		public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue) {
+		public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue, EventType eventType) {
 			return UUID.randomUUID();
 		}
 	}