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.copying;
014
015import org.mmtk.plan.generational.GenMutator;
016import org.mmtk.policy.CopyLocal;
017import org.mmtk.policy.Space;
018import org.mmtk.utility.alloc.Allocator;
019import org.mmtk.vm.VM;
020
021import org.vmmagic.unboxed.*;
022import org.vmmagic.pragma.*;
023
024/**
025 * This class implements <i>per-mutator thread</i> behavior and state for
026 * the <code>GenCopy</code> two-generational copying collector.<p>
027 *
028 * Specifically, this class defines mutator-time semantics specific to the
029 * mature generation (<code>GenMutator</code> defines nursery semantics).
030 * In particular the mature space allocator is defined (for mutator-time
031 * allocation into the mature space via pre-tenuring), and the mature space
032 * per-mutator thread collection time semantics are defined (rebinding
033 * the mature space allocator).<p>
034 *
035 * @see GenCopy for a description of the <code>GenCopy</code> algorithm.
036 *
037 * @see GenCopy
038 * @see GenCopyCollector
039 * @see GenMutator
040 * @see org.mmtk.plan.StopTheWorldMutator
041 * @see org.mmtk.plan.MutatorContext
042 */
043@Uninterruptible
044public class GenCopyMutator extends GenMutator {
045  /******************************************************************
046   * Instance fields
047   */
048
049  /**
050   * The allocator for the copying mature space (the mutator may
051   * "pretenure" objects into this space otherwise used only by
052   * the collector)
053   */
054  private final CopyLocal mature;
055
056  /****************************************************************************
057   *
058   * Initialization
059   */
060
061  /**
062   * Constructor
063   */
064  public GenCopyMutator() {
065    mature = new CopyLocal();
066  }
067
068  /**
069   * Called before the MutatorContext is used, but after the context has been
070   * fully registered and is visible to collection.
071   */
072  @Override
073  public void initMutator(int id) {
074    super.initMutator(id);
075    mature.rebind(GenCopy.toSpace());
076  }
077
078  /****************************************************************************
079   *
080   * Mutator-time allocation
081   */
082
083  /**
084   * {@inheritDoc}
085   */
086  @Override
087  @Inline
088  public final Address alloc(int bytes, int align, int offset, int allocator, int site) {
089    if (allocator == GenCopy.ALLOC_MATURE) {
090      return mature.alloc(bytes, align, offset);
091    }
092    return super.alloc(bytes, align, offset, allocator, site);
093  }
094
095  @Override
096  @Inline
097  public final void postAlloc(ObjectReference object, ObjectReference typeRef,
098      int bytes, int allocator) {
099    // nothing to be done
100    if (allocator == GenCopy.ALLOC_MATURE) return;
101    super.postAlloc(object, typeRef, bytes, allocator);
102  }
103
104  @Override
105  public final Allocator getAllocatorFromSpace(Space space) {
106    if (space == GenCopy.matureSpace0 || space == GenCopy.matureSpace1) return mature;
107    return super.getAllocatorFromSpace(space);
108  }
109
110
111  /*****************************************************************************
112   *
113   * Collection
114   */
115
116  /**
117   * {@inheritDoc}
118   */
119  @Override
120  public void collectionPhase(short phaseId, boolean primary) {
121    if (global().traceFullHeap()) {
122      if (phaseId == GenCopy.RELEASE) {
123        super.collectionPhase(phaseId, primary);
124        if (global().gcFullHeap) mature.rebind(GenCopy.toSpace());
125        return;
126      }
127    }
128
129    super.collectionPhase(phaseId, primary);
130  }
131
132  /*****************************************************************************
133   *
134   * Miscellaneous
135   */
136
137  /** @return The active global plan as a <code>GenCopy</code> instance. */
138  private static GenCopy global() {
139    return (GenCopy) VM.activePlan.global();
140  }
141
142}