slider-core/src/main/java/org/apache/slider/server/services/workflow/ServiceParent.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.slider.server.services.workflow;

import org.apache.hadoop.service.Service;

import java.util.List;

/**
 * Interface for accessing services that contain one or more child
 * services. 
 */
public interface ServiceParent extends Service {

  /**
   * Add a child service. It must be in a consistent state with the
   * service to which it is being added.
   * @param service the service to add.
   */
  void addService(Service service);

  /**
   * Get an unmodifiable list of services
   * @return a list of child services at the time of invocation -
   * added services will not be picked up.
   */
  List<Service> getServices();
}