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.wake.time.event;
020
021import org.apache.reef.wake.EventHandler;
022import org.apache.reef.wake.time.Time;
023
024/**
025 * An alarm is a timer event to be invoked at a given time.
026 * Contains a (future) timestamp and the event handler to invoke.
027 */
028public abstract class Alarm extends Time implements Runnable {
029
030  private final EventHandler<Alarm> handler;
031
032  public Alarm(final long timestamp, final EventHandler<Alarm> handler) {
033    super(timestamp);
034    this.handler = handler;
035  }
036
037  /**
038   * Invoke the event handler and pass a reference to self as a parameter.
039   */
040  @Override
041  public final void run() {
042    this.handler.onNext(this);
043  }
044}