/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.accumulo.server.zookeeper;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import org.apache.accumulo.core.Constants;
import org.apache.accumulo.fate.zookeeper.DistributedReadWriteLock;
import org.apache.zookeeper.KeeperException;
public class ZooQueueLock extends org.apache.accumulo.fate.zookeeper.ZooQueueLock {
public ZooQueueLock(String path, boolean ephemeral) throws KeeperException, InterruptedException {
super(ZooReaderWriter.getRetryingInstance(), path, ephemeral);
}
public static void main(String args[]) throws InterruptedException, KeeperException {
ZooQueueLock lock = new ZooQueueLock("/lock", true);
DistributedReadWriteLock rlocker = new DistributedReadWriteLock(lock, "reader".getBytes(Constants.UTF8));
DistributedReadWriteLock wlocker = new DistributedReadWriteLock(lock, "wlocker".getBytes(Constants.UTF8));
final Lock readLock = rlocker.readLock();
readLock.lock();
final Lock readLock2 = rlocker.readLock();
readLock2.lock();
final Lock writeLock = wlocker.writeLock();
if (writeLock.tryLock(100, TimeUnit.MILLISECONDS))
throw new RuntimeException("Write lock achieved during read lock!");
readLock.unlock();
readLock2.unlock();
writeLock.lock();
if (readLock.tryLock(100, TimeUnit.MILLISECONDS))
throw new RuntimeException("Read lock achieved during write lock!");
final Lock writeLock2 = DistributedReadWriteLock.recoverLock(lock, "wlocker".getBytes(Constants.UTF8));
writeLock2.unlock();
readLock.lock();
System.out.println("success");
}
}