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.TraceLocal;
016    import org.mmtk.plan.Trace;
017    import org.mmtk.policy.Space;
018    
019    import org.vmmagic.pragma.*;
020    import org.vmmagic.unboxed.*;
021    
022    /**
023     * This class implements the thread-local core functionality for a transitive
024     * closure over the heap graph.
025     */
026    @Uninterruptible
027    public final class NoGCTraceLocal extends TraceLocal {
028    
029      /**
030       * Constructor
031       */
032      public NoGCTraceLocal(Trace trace) {
033        super(trace);
034      }
035    
036    
037      /****************************************************************************
038       * Externally visible Object processing and tracing
039       */
040    
041      /**
042       * {@inheritDoc}
043       */
044      @Override
045      public boolean isLive(ObjectReference object) {
046        if (object.isNull()) return false;
047        if (Space.isInSpace(NoGC.NOGC, object)) {
048          return NoGC.noGCSpace.isLive(object);
049        }
050        return super.isLive(object);
051      }
052    
053      @Inline
054      @Override
055      public ObjectReference traceObject(ObjectReference object) {
056        if (object.isNull()) return object;
057        if (Space.isInSpace(NoGC.NOGC, object))
058          return NoGC.noGCSpace.traceObject(this, object);
059        return super.traceObject(object);
060      }
061    }