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.copyms;
014
015import org.mmtk.plan.StopTheWorldConstraints;
016
017import org.mmtk.policy.CopySpace;
018import org.mmtk.policy.SegregatedFreeListSpace;
019
020import org.vmmagic.pragma.*;
021
022/**
023 * This class and its subclasses communicate to the host VM/Runtime
024 * any features of the selected plan that it needs to know.  This is
025 * separate from the main Plan/PlanLocal class in order to bypass any
026 * issues with ordering of static initialization.
027 */
028@Uninterruptible
029public class CopyMSConstraints extends StopTheWorldConstraints {
030
031  @Override
032  public int gcHeaderBits() {
033    return CopySpace.LOCAL_GC_BITS_REQUIRED;
034  }
035  @Override
036  public int gcHeaderWords() {
037    return CopySpace.GC_HEADER_WORDS_REQUIRED;
038  }
039  @Override
040  public int numSpecializedScans() {
041    return 1;
042  }
043  @Override
044  public boolean movesObjects() {
045    return true;
046  }
047  @Override
048  public int maxNonLOSCopyBytes() {
049    return SegregatedFreeListSpace.MAX_FREELIST_OBJECT_BYTES;
050  }
051}