DaemonWatcher.java

/*
 * 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.hms.common.util;

public class DaemonWatcher extends PidFile {
  private static DaemonWatcher instance = null;
  
  public synchronized static DaemonWatcher createInstance(String name, int port) {
    if(instance == null) {
      instance = new DaemonWatcher(name, port);
      Runtime.getRuntime().addShutdownHook(instance);
    }
    return instance;
  }
  
  public static DaemonWatcher getInstance() {
    return instance;
  }
  
  private DaemonWatcher(String name, int port) {
    super(name, port);
  }
  
  public static void bailout(int status) {
    System.exit(status);
  }
}