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
019package org.apache.hadoop.yarn.state;
020
021import org.apache.hadoop.classification.InterfaceAudience.Public;
022import org.apache.hadoop.classification.InterfaceStability.Evolving;
023
024/**
025 * Hook for Transition. This lead to state machine to move to 
026 * the post state as registered in the state machine.
027 */
028@Public
029@Evolving
030public interface SingleArcTransition<OPERAND, EVENT> {
031  /**
032   * Transition hook.
033   * 
034   * @param operand the entity attached to the FSM, whose internal 
035   *                state may change.
036   * @param event causal event
037   */
038  public void transition(OPERAND operand, EVENT event);
039
040}