001/* 002 * JPPF. 003 * Copyright (C) 2005-2018 JPPF Team. 004 * http://www.jppf.org 005 * 006 * Licensed under the Apache License, Version 2.0 (the "License"); 007 * you may not use this file except in compliance with the License. 008 * You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 019package org.jppf.load.balancer.persistence; 020 021import java.util.concurrent.locks.Lock; 022 023/** 024 * This interface is implemented by load-balancers that wish to persist their state. 025 * @author Laurent Cohen 026 * @since 6.0 027 */ 028public interface PersistentState { 029 /** 030 * Get this bundler's state. 031 * @return an Object representing the state of the load-balancer. 032 */ 033 Object getState(); 034 035 /** 036 * Set this bundler's state. 037 * @param state an Object representing the state of the load-balancer. 038 */ 039 void setState(Object state); 040 041 /** 042 * Get a lock that can be used to synchronize access to the load-balancer state. 043 * The main usage is to avoid race conditions when the state is serialized by the persistence thread, 044 * while it is being updated, in particular via its {@code feedback()} method, in another thread. 045 * @return a {@link Lock} object. 046 */ 047 Lock getStateLock(); 048}