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.mmtk.plan.nogc;
014    
015    import org.mmtk.plan.PlanConstraints;
016    
017    import org.vmmagic.pragma.*;
018    
019    /**
020     * This class and its subclasses communicate to the host VM/Runtime
021     * any features of the selected plan that it needs to know.  This is
022     * separate from the main Plan/PlanLocal class in order to bypass any
023     * issues with ordering of static initialization.
024     */
025    @Uninterruptible
026    public class NoGCConstraints extends PlanConstraints {
027      @Override
028      public int gcHeaderBits() { return 0; }
029      @Override
030      public int gcHeaderWords() { return 0; }
031    }