/**
* 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.drill.exec.coord.zk;
import java.util.concurrent.TimeUnit;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.recipes.locks.InterProcessSemaphoreV2;
import org.apache.curator.framework.recipes.locks.Lease;
import org.apache.drill.exec.coord.DistributedSemaphore;
public class ZkDistributedSemaphore implements DistributedSemaphore{
static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(ZkDistributedSemaphore.class);
final InterProcessSemaphoreV2 semaphore;
public ZkDistributedSemaphore(CuratorFramework client, String path, int numberOfLeases) {
this.semaphore = new InterProcessSemaphoreV2(client, path, numberOfLeases);
}
@Override
public DistributedLease acquire(long time, TimeUnit unit) throws Exception {
Lease lease = semaphore.acquire(time, unit);
if(lease != null){
return new LeaseHolder(lease);
}else{
return null;
}
}
private class LeaseHolder implements DistributedLease{
Lease lease;
public LeaseHolder(Lease lease) {
super();
this.lease = lease;
}
@Override
public void close() throws Exception {
lease.close();
}
}
}