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.refcount.generational;
014    
015    import org.mmtk.plan.refcount.RCBase;
016    import org.mmtk.plan.refcount.RCBaseMutator;
017    import org.mmtk.policy.CopyLocal;
018    import org.mmtk.policy.Space;
019    import org.mmtk.utility.alloc.Allocator;
020    import org.vmmagic.pragma.*;
021    import org.vmmagic.unboxed.Address;
022    import org.vmmagic.unboxed.ObjectReference;
023    
024    /**
025     * This class implements the mutator context for a simple reference counting collector.
026     */
027    @Uninterruptible
028    public class GenRCMutator extends RCBaseMutator {
029      /************************************************************************
030       * Instance fields
031       */
032    
033      /**
034       *
035       */
036      private final CopyLocal nursery;
037    
038      public GenRCMutator() {
039        nursery = new CopyLocal(GenRC.nurserySpace);
040      }
041    
042      /****************************************************************************
043       *
044       * Mutator-time allocation
045       */
046    
047      /**
048       * {@inheritDoc}
049       */
050      @Override
051      @Inline
052      public Address alloc(int bytes, int align, int offset, int allocator, int site) {
053        if (allocator == GenRC.ALLOC_NURSERY) {
054          return nursery.alloc(bytes, align, offset);
055        }
056        return super.alloc(bytes, align, offset, allocator, site);
057      }
058    
059      @Override
060      @Inline
061      public void postAlloc(ObjectReference ref, ObjectReference typeRef, int bytes, int allocator) {
062        if (allocator == GenRC.ALLOC_NURSERY) {
063          return;
064        }
065        super.postAlloc(ref, typeRef, bytes, allocator);
066      }
067    
068      @Override
069      public Allocator getAllocatorFromSpace(Space space) {
070        if (space == GenRC.nurserySpace) return nursery;
071    
072        return super.getAllocatorFromSpace(space);
073      }
074    
075      /****************************************************************************
076       *
077       * Collection
078       */
079    
080      /**
081       * {@inheritDoc}
082       */
083      @Override
084      public final void collectionPhase(short phaseId, boolean primary) {
085        if (phaseId == RCBase.PREPARE) {
086          nursery.rebind(GenRC.nurserySpace);
087          super.collectionPhase(phaseId, primary);
088          return;
089        }
090    
091        super.collectionPhase(phaseId, primary);
092      }
093    }