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.immix;
014
015import org.mmtk.plan.StopTheWorldConstraints;
016import org.mmtk.policy.immix.ObjectHeader;
017
018import static org.mmtk.policy.immix.ImmixConstants.MAX_IMMIX_OBJECT_BYTES;
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 ImmixConstraints extends StopTheWorldConstraints {
030
031  @Override
032  public int gcHeaderBits() {
033    return ObjectHeader.LOCAL_GC_BITS_REQUIRED;
034  }
035
036  @Override
037  public int gcHeaderWords() {
038    return ObjectHeader.GC_HEADER_WORDS_REQUIRED;
039  }
040
041  @Override
042  public boolean movesObjects() {
043    return true;
044  }
045
046  @Override
047  public int numSpecializedScans() {
048    return 2;
049  }
050
051  @Override
052  public int maxNonLOSDefaultAllocBytes() {
053    return MAX_IMMIX_OBJECT_BYTES;
054  }
055
056  @Override
057  public int maxNonLOSCopyBytes() {
058    return MAX_IMMIX_OBJECT_BYTES;
059  }
060}