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.mmtk.plan.semispace.gcspy;
014
015import org.mmtk.plan.Trace;
016import org.mmtk.plan.semispace.SSTraceLocal;
017import org.mmtk.policy.Space;
018
019import org.vmmagic.pragma.*;
020import org.vmmagic.unboxed.*;
021
022/**
023 * This class implements the core functionality for a transitive
024 * closure over the heap graph.
025 */
026@Uninterruptible
027public final class SSGCspyTraceLocal extends SSTraceLocal {
028
029  /**
030   * @param trace the associated global trace
031   */
032  public SSGCspyTraceLocal(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  @Inline
046  public ObjectReference traceObject(ObjectReference object) {
047    if (object.isNull()) return object;
048    if (Space.isInSpace(SSGCspy.GCSPY, object))
049      return SSGCspy.gcspySpace.traceObject(this, object);
050    return super.traceObject(object);
051  }
052
053  /**
054   * Will this object move from this point on, during the current trace ?
055   *
056   * @param object The object to query.
057   * @return True if the object will not move.
058   */
059  @Override
060  public boolean willNotMoveInCurrentCollection(ObjectReference object) {
061    if (Space.isInSpace(SSGCspy.GCSPY, object))
062      return true;
063    return super.willNotMoveInCurrentCollection(object);
064  }
065}