001    /**
002    * Licensed to the Apache Software Foundation (ASF) under one
003    * or more contributor license agreements.  See the NOTICE file
004    * distributed with this work for additional information
005    * regarding copyright ownership.  The ASF licenses this file
006    * to you under the Apache License, Version 2.0 (the
007    * "License"); you may not use this file except in compliance
008    * with the License.  You may obtain a copy of the License at
009    *
010    *     http://www.apache.org/licenses/LICENSE-2.0
011    *
012    * Unless required by applicable law or agreed to in writing, software
013    * distributed under the License is distributed on an "AS IS" BASIS,
014    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015    * See the License for the specific language governing permissions and
016    * limitations under the License.
017    */
018    
019    package org.apache.hadoop.yarn.state;
020    
021    import org.apache.hadoop.classification.InterfaceAudience.Public;
022    import org.apache.hadoop.classification.InterfaceStability.Evolving;
023    
024    @Public
025    @Evolving
026    public interface StateMachine
027                     <STATE extends Enum<STATE>,
028                      EVENTTYPE extends Enum<EVENTTYPE>, EVENT> {
029      public STATE getCurrentState();
030      public STATE doTransition(EVENTTYPE eventType, EVENT event)
031            throws InvalidStateTransitonException;
032    }