code: /**
   * Copyright (c) 2015-2016 YCSB contributors. All rights reserved.
   *
   * Licensed 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. See accompanying
   * LICENSE file.
   */
  
  package com.yahoo.ycsb.db;
  
  import java.util.Properties;
  
  import org.infinispan.client.hotrod.RemoteCacheManager;
  
  /**
   * Utility class to ensure only a single RemoteCacheManager is created.
   */
  final class RemoteCacheManagerHolder {
  
    private static volatile RemoteCacheManager cacheManager = null;
  
    private RemoteCacheManagerHolder() {
    }
  
    static RemoteCacheManager getInstance(Properties props) {
      RemoteCacheManager result = cacheManager;
      if (result == null) {
        synchronized (RemoteCacheManagerHolder.class) {
          result = cacheManager;
          if (result == null) {
            result = new RemoteCacheManager(props);
            cacheManager = new RemoteCacheManager(props);
          }
        }
      }
      return result;
    }
  }
  