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.generational.immix;
014
015import static org.mmtk.policy.immix.ImmixConstants.MARK_LINE_AT_SCAN_TIME;
016
017import org.mmtk.plan.generational.GenCollector;
018import org.mmtk.plan.generational.GenMatureTraceLocal;
019import org.mmtk.plan.Trace;
020import org.mmtk.policy.Space;
021import org.mmtk.utility.Log;
022import org.mmtk.utility.options.Options;
023import org.mmtk.vm.VM;
024
025import org.vmmagic.unboxed.*;
026import org.vmmagic.pragma.*;
027
028/**
029 * This class implements the core functionality for a transitive
030 * closure over the heap graph, specifically in a defragmenting pass over
031 * a generational immix collector.
032 */
033@Uninterruptible
034public final class GenImmixMatureDefragTraceLocal extends GenMatureTraceLocal{
035
036  /**
037   * @param global the global trace class to use
038   * @param plan the state of the generational collector
039   */
040  public GenImmixMatureDefragTraceLocal(Trace global, GenCollector plan) {
041    super(-1, global, plan);
042  }
043
044  @Override
045  public boolean isLive(ObjectReference object) {
046    if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(GenImmix.immixSpace.inImmixDefragCollection());
047    if (object.isNull()) return false;
048    if (Space.isInSpace(GenImmix.IMMIX, object)) {
049      return GenImmix.immixSpace.isLive(object);
050    }
051    return super.isLive(object);
052  }
053
054  @Override
055  @Inline
056  public ObjectReference traceObject(ObjectReference object) {
057    if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(GenImmix.immixSpace.inImmixDefragCollection());
058    if (object.isNull()) return object;
059    if (Space.isInSpace(GenImmix.IMMIX, object))
060      return GenImmix.immixSpace.traceObject(this, object, GenImmix.ALLOC_MATURE_MAJORGC);
061    return super.traceObject(object);
062  }
063
064  @Override
065  public boolean willNotMoveInCurrentCollection(ObjectReference object) {
066    if (Space.isInSpace(GenImmix.IMMIX, object)) {
067      return GenImmix.immixSpace.willNotMoveThisGC(object);
068    }
069    return super.willNotMoveInCurrentCollection(object);
070  }
071
072  @Inline
073  @Override
074  protected void scanObject(ObjectReference object) {
075    if (VM.VERIFY_ASSERTIONS && Options.verbose.getValue() >= 9) {
076      Log.write("SO["); Log.write(object); Log.writeln("]");
077    }
078    super.scanObject(object);
079    if (MARK_LINE_AT_SCAN_TIME && Space.isInSpace(GenImmix.IMMIX, object))
080      GenImmix.immixSpace.markLines(object);
081  }
082}