Java LockMode.UPGRADE_SKIPLOCKED屬性代碼示例

protected boolean shouldUseFollowOnLocking(
		QueryParameters parameters,
		Dialect dialect,
		List<AfterLoadAction> afterLoadActions) {
	if ( dialect.useFollowOnLocking() ) {
		// currently only one lock mode is allowed in follow-on locking
		final LockMode lockMode = determineFollowOnLockMode( parameters.getLockOptions() );
		final LockOptions lockOptions = new LockOptions( lockMode );
		if ( lockOptions.getLockMode() != LockMode.UPGRADE_SKIPLOCKED ) {
			LOG.usingFollowOnLocking();
			lockOptions.setTimeOut( parameters.getLockOptions().getTimeOut() );
			lockOptions.setScope( parameters.getLockOptions().getScope() );
			afterLoadActions.add(
					new AfterLoadAction() {
						@Override
						public void afterLoad(SessionImplementor session, Object entity, Loadable persister) {
							( (Session) session ).buildLockRequest( lockOptions ).lock( persister.getEntityName(), entity );
						}
					}
			);
			parameters.setLockOptions( new LockOptions() );
			return true;
		}
	}
	return false;
}
 

/**
 * Convert from the Hibernate specific LockMode to the JPA defined LockModeType.
 *
 * @param lockMode The Hibernate LockMode.
 *
 * @return The JPA LockModeType
 */
public static LockModeType convertToLockModeType(LockMode lockMode) {
	if ( lockMode == LockMode.NONE ) {
		return LockModeType.NONE;
	}
	else if ( lockMode == LockMode.OPTIMISTIC || lockMode == LockMode.READ ) {
		return LockModeType.OPTIMISTIC;
	}
	else if ( lockMode == LockMode.OPTIMISTIC_FORCE_INCREMENT || lockMode == LockMode.WRITE ) {
		return LockModeType.OPTIMISTIC_FORCE_INCREMENT;
	}
	else if ( lockMode == LockMode.PESSIMISTIC_READ ) {
		return LockModeType.PESSIMISTIC_READ;
	}
	else if ( lockMode == LockMode.PESSIMISTIC_WRITE
			|| lockMode == LockMode.UPGRADE
			|| lockMode == LockMode.UPGRADE_NOWAIT
               || lockMode == LockMode.UPGRADE_SKIPLOCKED) {
		return LockModeType.PESSIMISTIC_WRITE;
	}
	else if ( lockMode == LockMode.PESSIMISTIC_FORCE_INCREMENT
			|| lockMode == LockMode.FORCE ) {
		return LockModeType.PESSIMISTIC_FORCE_INCREMENT;
	}
	throw new AssertionFailure( "unhandled lock mode " + lockMode );
}
 

/**
 * Handle the given lock event.
 *
 * @param event The lock event to be handled.
 * @throws HibernateException
 */
public void onLock(LockEvent event) throws HibernateException {

	if ( event.getObject() == null ) {
		throw new NullPointerException( "attempted to lock null" );
	}

	if ( event.getLockMode() == LockMode.WRITE ) {
		throw new HibernateException( "Invalid lock mode for lock()" );
	}

	if ( event.getLockMode() == LockMode.UPGRADE_SKIPLOCKED ) {
		LOG.explicitSkipLockedLockCombo();
	}

	SessionImplementor source = event.getSession();
	
	Object entity = source.getPersistenceContext().unproxyAndReassociate( event.getObject() );
	//TODO: if object was an uninitialized proxy, this is inefficient,
	//      resulting in two SQL selects
	
	EntityEntry entry = source.getPersistenceContext().getEntry(entity);
	if (entry==null) {
		final EntityPersister persister = source.getEntityPersister( event.getEntityName(), entity );
		final Serializable id = persister.getIdentifier( entity, source );
		if ( !ForeignKeys.isNotTransient( event.getEntityName(), entity, Boolean.FALSE, source ) ) {
			throw new TransientObjectException(
					"cannot lock an unsaved transient instance: " +
					persister.getEntityName()
			);
		}

		entry = reassociate(event, entity, id, persister);
		cascadeOnLock(event, persister, entity);
	}

	upgradeLock( entity, entry, event.getLockOptions(), event.getSession() );
}
 

private static LockMode getLockMode(String lockMode) {
	if ( lockMode == null || "read".equals( lockMode ) ) {
		return LockMode.READ;
	}
	else if ( "none".equals( lockMode ) ) {
		return LockMode.NONE;
	}
	else if ( "upgrade".equals( lockMode ) ) {
		return LockMode.UPGRADE;
	}
	else if ( "upgrade-nowait".equals( lockMode ) ) {
		return LockMode.UPGRADE_NOWAIT;
	}
	else if ( "upgrade-skiplocked".equals( lockMode )) {
		return LockMode.UPGRADE_SKIPLOCKED;
	}
	else if ( "write".equals( lockMode ) ) {
		return LockMode.WRITE;
	}
	else if ( "force".equals( lockMode ) ) {
		return LockMode.FORCE;
	}
	else if ( "optimistic".equals( lockMode ) ) {
		return LockMode.OPTIMISTIC;
	}
	else if ( "optimistic_force_increment".equals( lockMode ) ) {
		return LockMode.OPTIMISTIC_FORCE_INCREMENT;
	}
	else if ( "pessimistic_read".equals( lockMode ) ) {
		return LockMode.PESSIMISTIC_READ;
	}
	else if ( "pessimistic_write".equals( lockMode ) ) {
		return LockMode.PESSIMISTIC_WRITE;
	}
	else if ( "pessimistic_force_increment".equals( lockMode ) ) {
		return LockMode.PESSIMISTIC_FORCE_INCREMENT;
	}
	else {
		throw new MappingException( "unknown lockmode" );
	}
}