Source code

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,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.task;
020
021import org.apache.reef.annotations.Unstable;
022import org.apache.reef.annotations.audience.Public;
023import org.apache.reef.annotations.audience.TaskSide;
024import org.apache.reef.runtime.common.evaluator.HeartBeatManager;
025
026import javax.inject.Inject;
027
028/**
029 * Helper class for immediately sending heartbeat messages.
030 * This can be used together with TaskMessageSource to push urgent messages to the Driver.
031 * <p/>
032 * CAUTION: Do not overuse as the Driver can be saturated with heartbeats.
033 *
034 * @see https://issues.apache.org/jira/browse/REEF-33 for the ongoing discussion of alternatives to this design.
035 */
036@TaskSide
037@Public
038@Unstable
039public class HeartBeatTriggerManager {
040  private final HeartBeatManager heartBeatManager;
041
042  @Inject
043  HeartBeatTriggerManager(final HeartBeatManager heartBeatManager) {
044    this.heartBeatManager = heartBeatManager;
045  }
046
047  /**
048   * Immediately send a heartbeat message to the Driver.
049   */
050  public void triggerHeartBeat() {
051    this.heartBeatManager.sendHeartbeat();
052  }
053}