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     */
013    package org.jikesrvm.adaptive.measurements.listeners;
014    
015    import org.vmmagic.pragma.Uninterruptible;
016    import org.vmmagic.unboxed.Address;
017    
018    /**
019     * This object that is invoked when online measurement information must
020     * be collected.
021     */
022    @Uninterruptible
023    public abstract class ContextListener extends Listener {
024    
025      /**
026       * Entry point when listener is awoken.
027       *
028       * @param sfp  pointer to stack frame where call stack should start
029       *             to be examined.
030       * @param whereFrom Was this a yieldpoint in a PROLOGUE, BACKEDGE, or
031       *            EPILOGUE?
032       */
033      public abstract void update(Address sfp, int whereFrom);
034    }