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MCConstraints.java
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MCConstraints.java
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/*
* This file is part of the Jikes RVM project (http://jikesrvm.org).
*
* This file is licensed to You under the Common Public License (CPL);
* You may not use this file except in compliance with the License. You
* may obtain a copy of the License at
*
* http://www.opensource.org/licenses/cpl1.0.php
*
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership.
*/
package org.mmtk.plan.markcompact;
import org.mmtk.plan.StopTheWorldConstraints;
import org.mmtk.policy.MarkCompactSpace;
import org.vmmagic.pragma.*;
/**
* This class and its subclasses communicate to the host VM/Runtime
* any features of the selected plan that it needs to know. This is
* separate from the main Plan/PlanLocal class in order to bypass any
* issues with ordering of static initialization.
*/
@Uninterruptible public class MCConstraints extends StopTheWorldConstraints {
public boolean movesObjects() { return true; }
public boolean needsForwardAfterLiveness() { return true; }
public boolean needsLinearScan() { return true; }
public int gcHeaderBits() { return MarkCompactSpace.LOCAL_GC_BITS_REQUIRED; }
public int gcHeaderWords() { return MarkCompactSpace.GC_HEADER_WORDS_REQUIRED; }
public int numSpecializedScans() { return 2; }
}