001/*
002 *  This file is part of the Jikes RVM project (http://jikesrvm.org).
003 *
004 *  This file is licensed to You under the Eclipse Public License (EPL);
005 *  You may not use this file except in compliance with the License. You
006 *  may obtain a copy of the License at
007 *
008 *      http://www.opensource.org/licenses/eclipse-1.0.php
009 *
010 *  See the COPYRIGHT.txt file distributed with this work for information
011 *  regarding copyright ownership.
012 */
013package org.jikesrvm.adaptive.measurements.listeners;
014
015import org.vmmagic.pragma.Uninterruptible;
016
017/**
018 * A NullListener is an object that is invoked when
019 * online measurement information must be collected.
020 *  <p>
021 * Defines update's interface.
022 */
023@Uninterruptible
024public abstract class NullListener extends Listener {
025  /**
026   * This method is called when its time to record that a
027   * yield point has occurred.
028   * @param whereFrom Was this a yieldpoint in a PROLOGUE, BACKEDGE, or
029   *             EPILOGUE?
030   */
031  public abstract void update(int whereFrom);
032}