| /* |
| * Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved. |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v. 2.0, which is available at |
| * http://www.eclipse.org/legal/epl-2.0. |
| * |
| * This Source Code may also be made available under the following Secondary |
| * Licenses when the conditions for such availability set forth in the |
| * Eclipse Public License v. 2.0 are satisfied: GNU General Public License, |
| * version 2 with the GNU Classpath Exception, which is available at |
| * https://www.gnu.org/software/classpath/license.html. |
| * |
| * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 |
| */ |
| |
| package com.sun.jaspic.config.helper; |
| |
| import java.util.concurrent.locks.Lock; |
| import java.util.concurrent.locks.ReentrantReadWriteLock; |
| |
| /** |
| * |
| * @author Ron Monzillo |
| */ |
| |
| public class EpochCarrier { |
| |
| private Lock instanceReadLock; |
| private Lock instanceWriteLock; |
| |
| private long epoch; |
| |
| public EpochCarrier() { |
| ReentrantReadWriteLock instanceReadWriteLock = new ReentrantReadWriteLock(); |
| instanceReadLock = instanceReadWriteLock.readLock(); |
| instanceWriteLock = instanceReadWriteLock.writeLock(); |
| epoch = 0L; |
| } |
| |
| public long increment() { |
| instanceWriteLock.lock(); |
| long before; |
| try { |
| before = epoch; |
| epoch = epoch + 1; |
| } finally { |
| instanceWriteLock.unlock(); |
| } |
| return before; |
| } |
| |
| public long getEpoch() { |
| instanceReadLock.lock(); |
| try { |
| return epoch; |
| } finally { |
| instanceReadLock.unlock(); |
| } |
| } |
| |
| public boolean hasChanged(long reference) { |
| instanceReadLock.lock(); |
| try { |
| return epoch != reference; |
| } finally { |
| instanceReadLock.unlock(); |
| } |
| } |
| |
| } |