attempt to reduce allocations of LockOptions

- Sanne says we were allocating too many of these, so add a static instance
  of LockOptions for each LockMode
- just generally rationalize the code that deals with defaulting LockOptions
- change the impl of CascadingActions.LOCK because lock scope has nothing
  to do with cascading, and I don't see any reason why the LockOptions should
  not simply propagate if cascading is explicitly turned on

hibernate-core/src/main/java/org/hibernate/LockMode.java

@@ -208,4 +208,37 @@ public enum LockMode {
 
 		throw new IllegalArgumentException( "Unable to interpret LockMode reference from incoming external form : " + externalForm );
 	}
+
+	/**
+	 * @return an instance of {@link LockOptions} with this lock mode, and
+	 *         all other settings defaulted.
+	 */
+	public LockOptions toLockOptions() {
+		// we have to do this in a big switch to
+		// avoid circularities in the constructor
+		switch (this) {
+			case NONE:
+				return LockOptions.NONE;
+			case READ:
+				return LockOptions.READ;
+			case OPTIMISTIC:
+				return LockOptions.OPTIMISTIC;
+			case OPTIMISTIC_FORCE_INCREMENT:
+				return LockOptions.OPTIMISTIC_FORCE_INCREMENT;
+			case UPGRADE_NOWAIT:
+				return LockOptions.UPGRADE_NOWAIT;
+			case UPGRADE_SKIPLOCKED:
+				return LockOptions.UPGRADE_SKIPLOCKED;
+			case PESSIMISTIC_READ:
+				return LockOptions.PESSIMISTIC_READ;
+			case PESSIMISTIC_WRITE:
+				return LockOptions.PESSIMISTIC_WRITE;
+			case PESSIMISTIC_FORCE_INCREMENT:
+				return LockOptions.PESSIMISTIC_FORCE_INCREMENT;
+			case WRITE:
+				throw new UnsupportedOperationException("WRITE is not a valid LockMode as an argument");
+			default:
+				throw new IllegalStateException( "Unexpected value: " + this );
+		}
+	}
 }

hibernate-core/src/main/java/org/hibernate/LockOptions.java

@@ -55,13 +55,49 @@ public class LockOptions implements Serializable {
 	 * Represents {@link LockMode#NONE}, to which timeout and scope are
 	 * not applicable.
 	 */
-	public static final LockOptions NONE = new LockOptions(true, LockMode.NONE);
+	public static final LockOptions NONE = new LockOptions( true, LockMode.NONE );
 
 	/**
 	 * Represents {@link LockMode#READ}, to which timeout and scope are
 	 * not applicable.
 	 */
-	public static final LockOptions READ = new LockOptions(true, LockMode.READ);
+	public static final LockOptions READ = new LockOptions( true, LockMode.READ );
+
+	/**
+	 * Represents {@link LockMode#OPTIMISTIC}.
+	 */
+	static final LockOptions OPTIMISTIC = new LockOptions( true, LockMode.OPTIMISTIC );
+
+	/**
+	 * Represents {@link LockMode#OPTIMISTIC_FORCE_INCREMENT}, to which
+	 * timeout and scope are not applicable.
+	 */
+	static final LockOptions OPTIMISTIC_FORCE_INCREMENT = new LockOptions( true, LockMode.OPTIMISTIC_FORCE_INCREMENT );
+
+	/**
+	 * Represents {@link LockMode#PESSIMISTIC_READ}.
+	 */
+	static final LockOptions PESSIMISTIC_READ = new LockOptions( true, LockMode.PESSIMISTIC_READ );
+
+	/**
+	 * Represents {@link LockMode#PESSIMISTIC_WRITE}.
+	 */
+	static final LockOptions PESSIMISTIC_WRITE = new LockOptions( true, LockMode.PESSIMISTIC_WRITE );
+
+	/**
+	 * Represents {@link LockMode#PESSIMISTIC_FORCE_INCREMENT}.
+	 */
+	static final LockOptions PESSIMISTIC_FORCE_INCREMENT = new LockOptions( true, LockMode.PESSIMISTIC_FORCE_INCREMENT );
+
+	/**
+	 * Represents {@link LockMode#UPGRADE_NOWAIT}.
+	 */
+	static final LockOptions UPGRADE_NOWAIT = new LockOptions( true, LockMode.UPGRADE_NOWAIT );
+
+	/**
+	 * Represents {@link LockMode#UPGRADE_SKIPLOCKED}.
+	 */
+	static final LockOptions UPGRADE_SKIPLOCKED = new LockOptions( true, LockMode.UPGRADE_SKIPLOCKED );
 
 	/**
 	 * Represents {@link LockMode#PESSIMISTIC_WRITE} with
@@ -69,7 +105,7 @@ public class LockOptions implements Serializable {
 	 * {@linkplain PessimisticLockScope#NORMAL no extension of the
 	 * lock to owned collections}.
 	 */
-	public static final LockOptions UPGRADE = new LockOptions(true, LockMode.PESSIMISTIC_WRITE);
+	public static final LockOptions UPGRADE = PESSIMISTIC_WRITE;
 
 	/**
 	 * Indicates that the database should not wait at all to acquire

hibernate-core/src/main/java/org/hibernate/engine/spi/CascadingActions.java

@@ -92,18 +92,7 @@ public class CascadingActions {
 				LockOptions lockOptions,
 				boolean isCascadeDeleteEnabled) {
 			LOG.tracev( "Cascading to lock: {0}", entityName );
-			LockMode lockMode = LockMode.NONE;
-			LockOptions lr = new LockOptions();
-			if ( lockOptions != null ) {
-				lr.setTimeOut( lockOptions.getTimeOut() );
-				lr.setScope( lockOptions.getScope() );
-				lr.setFollowOnLocking( lockOptions.getFollowOnLocking() );
-				if ( lockOptions.getScope() ) {
-					lockMode = lockOptions.getLockMode();
-				}
-			}
-			lr.setLockMode( lockMode );
-			session.buildLockRequest( lr ).lock( entityName, child );
+			session.lock( entityName, child, lockOptions );
 		}
 
 		@Override

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

@@ -189,7 +189,7 @@ public class DefaultRefreshEventListener implements RefreshEventListener {
 			if ( currentLockMode.greaterThan( requestedLockMode ) ) {
 				// the requested lock-mode is less restrictive than the current one
 				//		- pass along the current lock-mode (after accounting for WRITE)
-				lockOptionsToUse = LockOptions.copy( event.getLockOptions(), new LockOptions() );
+				lockOptionsToUse = event.getLockOptions().makeCopy();
 				if ( currentLockMode == LockMode.WRITE
 						|| currentLockMode == LockMode.PESSIMISTIC_WRITE
 						|| currentLockMode == LockMode.PESSIMISTIC_READ ) {

hibernate-core/src/main/java/org/hibernate/event/spi/LoadEvent.java

@@ -6,7 +6,6 @@
  */
 package org.hibernate.event.spi;
 
-import org.hibernate.AssertionFailure;
 import org.hibernate.LockMode;
 import org.hibernate.LockOptions;
 
@@ -16,38 +15,20 @@ import org.hibernate.LockOptions;
  * @author Steve Ebersole
  */
 public class LoadEvent extends AbstractEvent {
-	public static final LockMode DEFAULT_LOCK_MODE = LockMode.NONE;
-	//Performance hotspot: avoid allocating unneeded LockOptions
-	public static final LockOptions DEFAULT_LOCK_OPTIONS = new LockOptions() {
-		@Override
-		public LockOptions setLockMode(LockMode lockMode) {
-			throw new AssertionFailure( "Should not be invoked: DEFAULT_LOCK_OPTIONS needs to be treated as immutable." );
-		}
-		@Override
-		public LockOptions setAliasSpecificLockMode(String alias, LockMode lockMode) {
-			throw new AssertionFailure( "Should not be invoked: DEFAULT_LOCK_OPTIONS needs to be treated as immutable." );
-		}
-		@Override
-		public LockOptions setTimeOut(int timeout) {
-			throw new AssertionFailure( "Should not be invoked: DEFAULT_LOCK_OPTIONS needs to be treated as immutable." );
-		}
-		@Override
-		public LockOptions setScope(boolean scope) {
-			throw new AssertionFailure( "Should not be invoked: DEFAULT_LOCK_OPTIONS needs to be treated as immutable." );
-		}
-	};
+//	public static final LockMode DEFAULT_LOCK_MODE = LockMode.NONE;
+//	public static final LockOptions DEFAULT_LOCK_OPTIONS = DEFAULT_LOCK_MODE.toLockOptions();
 
 	private Object entityId;
 	private String entityClassName;
 	private Object instanceToLoad;
-	private LockOptions lockOptions;
+	private final LockOptions lockOptions;
 	private final boolean isAssociationFetch;
 	private Object result;
 	private PostLoadEvent postLoadEvent;
 	private Boolean readOnly;
 
 	public LoadEvent(Object entityId, Object instanceToLoad, EventSource source, Boolean readOnly) {
-		this( entityId, null, instanceToLoad, DEFAULT_LOCK_OPTIONS, false, source, readOnly );
+		this( entityId, null, instanceToLoad, LockMode.NONE.toLockOptions(), false, source, readOnly );
 	}
 
 	public LoadEvent(Object entityId, String entityClassName, LockMode lockMode, EventSource source, Boolean readOnly) {
@@ -59,7 +40,7 @@ public class LoadEvent extends AbstractEvent {
 	}
 
 	public LoadEvent(Object entityId, String entityClassName, boolean isAssociationFetch, EventSource source, Boolean readOnly) {
-		this( entityId, entityClassName, null, DEFAULT_LOCK_OPTIONS, isAssociationFetch, source, readOnly );
+		this( entityId, entityClassName, null, LockMode.NONE.toLockOptions(), isAssociationFetch, source, readOnly );
 	}
 
 	private LoadEvent(
@@ -74,7 +55,7 @@ public class LoadEvent extends AbstractEvent {
 				entityId,
 				entityClassName,
 				instanceToLoad,
-				lockMode == DEFAULT_LOCK_MODE ? DEFAULT_LOCK_OPTIONS : new LockOptions().setLockMode( lockMode ),
+				lockMode.toLockOptions(),
 				isAssociationFetch,
 				source,
 				readOnly
@@ -100,7 +81,7 @@ public class LoadEvent extends AbstractEvent {
 			throw new IllegalArgumentException("Invalid lock mode for loading");
 		}
 		else if ( lockOptions.getLockMode() == null ) {
-			lockOptions.setLockMode(DEFAULT_LOCK_MODE);
+			lockOptions.setLockMode( LockMode.NONE );
 		}
 
 		this.entityId = entityId;
@@ -148,37 +129,10 @@ public class LoadEvent extends AbstractEvent {
 		return lockOptions.getLockMode();
 	}
 
-	public void setLockMode(LockMode lockMode) {
-		if ( lockMode != lockOptions.getLockMode() ) {
-			writingOnLockOptions();
-			this.lockOptions.setLockMode( lockMode );
-		}
-	}
-
-	private void writingOnLockOptions() {
-		if ( lockOptions == DEFAULT_LOCK_OPTIONS ) {
-			this.lockOptions = new LockOptions();
-		}
-	}
-
-	public void setLockTimeout(int timeout) {
-		if ( timeout != lockOptions.getTimeOut() ) {
-			writingOnLockOptions();
-			this.lockOptions.setTimeOut( timeout );
-		}
-	}
-
 	public int getLockTimeout() {
 		return this.lockOptions.getTimeOut();
 	}
 
-	public void setLockScope(boolean cascade) {
-		if ( lockOptions.getScope() != cascade ) {
-			writingOnLockOptions();
-			this.lockOptions.setScope( cascade );
-		}
-	}
-
 	public boolean getLockScope() {
 		return this.lockOptions.getScope();
 	}

hibernate-core/src/main/java/org/hibernate/event/spi/LockEvent.java

@@ -33,7 +33,7 @@ public class LockEvent extends AbstractEvent {
 	public LockEvent(Object object, LockMode lockMode, EventSource source) {
 		super(source);
 		this.object = object;
-		this.lockOptions = new LockOptions().setLockMode(lockMode);
+		this.lockOptions = lockMode.toLockOptions();
 	}
 
 	public LockEvent(Object object, LockOptions lockOptions, EventSource source) {
@@ -58,24 +58,12 @@ public class LockEvent extends AbstractEvent {
 		return lockOptions.getLockMode();
 	}
 
-	public void setLockMode(LockMode lockMode) {
-		this.lockOptions.setLockMode(lockMode);
-	}
-
-	public void setLockTimeout(int timeout) {
-		this.lockOptions.setTimeOut(timeout);
-	}
-
 	public int getLockTimeout() {
-		return this.lockOptions.getTimeOut();
-	}
-
-	public void setLockScope(boolean cascade) {
-		this.lockOptions.setScope(cascade);
+		return lockOptions.getTimeOut();
 	}
 
 	public boolean getLockScope() {
-		return this.lockOptions.getScope();
+		return lockOptions.getScope();
 	}
 
 	public String getEntityName() {

hibernate-core/src/main/java/org/hibernate/event/spi/ResolveNaturalIdEvent.java

@@ -31,7 +31,7 @@ public class ResolveNaturalIdEvent extends AbstractEvent {
 	private Object entityId;
 
 	public ResolveNaturalIdEvent(Map<String, Object> naturalIdValues, EntityPersister entityPersister, EventSource source) {
-		this( naturalIdValues, entityPersister, new LockOptions(), source );
+		this( naturalIdValues, entityPersister, LockOptions.NONE, source );
 	}
 
 	public ResolveNaturalIdEvent(

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

@@ -991,29 +991,7 @@ public class SessionImpl
 
 	@Override
 	public void load(Object object, Object id) throws HibernateException {
-		LoadEvent event = loadEvent;
-		loadEvent = null;
-		if ( event == null ) {
-			event = new LoadEvent( id, object, this, getReadOnlyFromLoadQueryInfluencers() );
-		}
-		else {
-			event.setEntityClassName( null );
-			event.setEntityId( id );
-			event.setInstanceToLoad( object );
-			event.setLockMode( LoadEvent.DEFAULT_LOCK_MODE );
-			event.setLockScope( LoadEvent.DEFAULT_LOCK_OPTIONS.getScope() );
-			event.setLockTimeout( LoadEvent.DEFAULT_LOCK_OPTIONS.getTimeOut() );
-		}
-
-		fireLoad( event, LoadEventListener.RELOAD );
-
-		if ( loadEvent == null ) {
-			event.setEntityClassName( null );
-			event.setEntityId( null );
-			event.setInstanceToLoad( null );
-			event.setResult( null );
-			loadEvent = event;
-		}
+		fireLoad( new LoadEvent( id, object, this, getReadOnlyFromLoadQueryInfluencers() ), LoadEventListener.RELOAD );
 	}
 
 	@Override @Deprecated
@@ -1054,13 +1032,7 @@ public class SessionImpl
 		event = recycleEventInstance( event, id, entityName );
 		fireLoadNoChecks( event, LoadEventListener.IMMEDIATE_LOAD );
 		Object result = event.getResult();
-		if ( loadEvent == null ) {
-			event.setEntityClassName( null );
-			event.setEntityId( null );
-			event.setInstanceToLoad( null );
-			event.setResult( null );
-			loadEvent = event;
-		}
+		finishWithEventInstance( event );
 		if ( result instanceof HibernateProxy ) {
 			return ( (HibernateProxy) result ).getHibernateLazyInitializer().getImplementation();
 		}
@@ -1073,6 +1045,7 @@ public class SessionImpl
 			Object id,
 			boolean eager,
 			boolean nullable) {
+		final LoadType type = internalLoadType( eager, nullable );
 		final EffectiveEntityGraph effectiveEntityGraph = getLoadQueryInfluencers().getEffectiveEntityGraph();
 		final GraphSemantic semantic = effectiveEntityGraph.getSemantic();
 		final RootGraphImplementor<?> graph = effectiveEntityGraph.getGraph();
@@ -1084,38 +1057,16 @@ public class SessionImpl
 				effectiveEntityGraph.clear();
 			}
 		}
-
 		try {
-			final LoadType type;
-			if ( nullable ) {
-				type = LoadEventListener.INTERNAL_LOAD_NULLABLE;
-			}
-			else {
-				type = eager
-						? LoadEventListener.INTERNAL_LOAD_EAGER
-						: LoadEventListener.INTERNAL_LOAD_LAZY;
-			}
-
 			LoadEvent event = loadEvent;
 			loadEvent = null;
-
 			event = recycleEventInstance( event, id, entityName );
-
 			fireLoadNoChecks( event, type );
-
 			Object result = event.getResult();
-
 			if ( !nullable ) {
 				UnresolvableObjectException.throwIfNull( result, id, entityName );
 			}
-
-			if ( loadEvent == null ) {
-				event.setEntityClassName( null );
-				event.setEntityId( null );
-				event.setInstanceToLoad( null );
-				event.setResult( null );
-				loadEvent = event;
-			}
+			finishWithEventInstance( event );
 			return result;
 		}
 		finally {
@@ -1125,6 +1076,17 @@ public class SessionImpl
 		}
 	}
 
+	private static LoadType internalLoadType(boolean eager, boolean nullable) {
+		if ( nullable ) {
+			return LoadEventListener.INTERNAL_LOAD_NULLABLE;
+		}
+		else {
+			return eager
+					? LoadEventListener.INTERNAL_LOAD_EAGER
+					: LoadEventListener.INTERNAL_LOAD_LAZY;
+		}
+	}
+
 	/**
 	 * Helper to avoid creating many new instances of LoadEvent: it's an allocation hot spot.
 	 */
@@ -1136,13 +1098,20 @@ public class SessionImpl
 			event.setEntityClassName( entityName );
 			event.setEntityId( id );
 			event.setInstanceToLoad( null );
-			event.setLockMode( LoadEvent.DEFAULT_LOCK_MODE );
-			event.setLockScope( LoadEvent.DEFAULT_LOCK_OPTIONS.getScope() );
-			event.setLockTimeout( LoadEvent.DEFAULT_LOCK_OPTIONS.getTimeOut() );
 			return event;
 		}
 	}
 
+	private void finishWithEventInstance(LoadEvent event) {
+		if ( loadEvent == null ) {
+			event.setEntityClassName( null );
+			event.setEntityId( null );
+			event.setInstanceToLoad( null );
+			event.setResult( null );
+			loadEvent = event;
+		}
+	}
+
 	@Override @Deprecated
 	public <T> T load(Class<T> entityClass, Object id, LockMode lockMode) throws HibernateException {
 		return this.byId( entityClass ).with( new LockOptions( lockMode ) ).getReference( id );
@@ -2123,9 +2092,9 @@ public class SessionImpl
 	private class LockRequestImpl implements LockRequest {
 		private final LockOptions lockOptions;
 
-		private LockRequestImpl(LockOptions lo) {
-			lockOptions = new LockOptions();
-			LockOptions.copy( lo, lockOptions );
+		private LockRequestImpl(LockOptions lockOptions) {
+			this.lockOptions = new LockOptions();
+			LockOptions.copy( lockOptions, this.lockOptions );
 		}
 
 		@Override

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

@@ -4356,7 +4356,7 @@ public abstract class AbstractEntityPersister
 	 */
 	@Override
 	public Object load(Object id, Object optionalObject, LockMode lockMode, SharedSessionContractImplementor session) {
-		return load( id, optionalObject, new LockOptions().setLockMode( lockMode ), session );
+		return load( id, optionalObject, lockMode.toLockOptions(), session );
 	}
 
 	/**

hibernate-core/src/main/java/org/hibernate/query/spi/AbstractQuery.java

@@ -309,8 +309,8 @@ public abstract class AbstractQuery<R>
 		}
 
 		if ( getLockOptions().getScope() ) {
-			hints.put( HINT_SPEC_LOCK_SCOPE, getLockOptions().getScope() );
-			hints.put( HINT_JAVAEE_LOCK_SCOPE, getLockOptions().getScope() );
+			hints.put( HINT_SPEC_LOCK_SCOPE, getLockOptions().getLockScope() );
+			hints.put( HINT_JAVAEE_LOCK_SCOPE, getLockOptions().getLockScope() );
 		}
 
 		if ( getLockOptions().hasAliasSpecificLockModes() ) {

hibernate-core/src/main/java/org/hibernate/query/spi/QueryOptionsAdapter.java

@@ -37,7 +37,7 @@ public abstract class QueryOptionsAdapter implements QueryOptions {
 
 	@Override
 	public LockOptions getLockOptions() {
-		return new LockOptions();
+		return LockOptions.NONE;
 	}
 
 	@Override

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

@@ -304,7 +304,7 @@ public class MatchingIdSelectionHelper {
 				,
 				executionContext.getSession()
 		);
-		final LockOptions lockOptions = executionContext.getQueryOptions().getLockOptions();
+		final LockOptions lockOptions = executionContext.getQueryOptions().getLockOptions().makeCopy();
 		final LockMode lockMode = lockOptions.getLockMode();
 		// Acquire a WRITE lock for the rows that are about to be modified
 		lockOptions.setLockMode( LockMode.WRITE );

hibernate-core/src/main/java/org/hibernate/sql/results/jdbc/internal/DeferredResultSetAccess.java

@@ -119,9 +119,10 @@ public class DeferredResultSetAccess extends AbstractResultSetAccess {
 
 						executionContext.getCallback().registerAfterLoadAction(
 								(session, entity, persister) -> {
-									( (Session) session ).buildLockRequest( lockOptionsToUse ).lock(
+									( (Session) session ).lock(
 											persister.getEntityName(),
-											entity
+											entity,
+											lockOptionsToUse
 									);
 								}
 						);