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.marksweep;
014
015import org.mmtk.plan.StopTheWorldConstraints;
016
017import org.mmtk.policy.MarkSweepSpace;
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 MSConstraints extends StopTheWorldConstraints {
030  @Override
031  public int gcHeaderBits() {
032    return MarkSweepSpace.LOCAL_GC_BITS_REQUIRED;
033  }
034  @Override
035  public int gcHeaderWords() {
036    return MarkSweepSpace.GC_HEADER_WORDS_REQUIRED;
037  }
038  @Override
039  public int maxNonLOSDefaultAllocBytes() {
040    return SegregatedFreeListSpace.MAX_FREELIST_OBJECT_BYTES;
041  }
042  @Override
043  public int numSpecializedScans() {
044    return 1;
045  }
046}