/*
 * 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.hadoop.hbase.util;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import org.apache.yetus.audience.InterfaceAudience;

@InterfaceAudience.Private
public class IdReadWriteLockStrongRef<T> extends IdReadWriteLock<T> {

  final ConcurrentHashMap<T, ReentrantReadWriteLock> map = new ConcurrentHashMap<>();

  @Override
  public ReentrantReadWriteLock getLock(T id) {
    ReentrantReadWriteLock existing = map.get(id);
    if (existing != null) {
      return existing;
    }

    ReentrantReadWriteLock newLock = new ReentrantReadWriteLock();
    existing = map.putIfAbsent(id, newLock);
    if (existing == null) {
      return newLock;
    } else {
      return existing;
    }
  }

}
