/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package sun.jvm.hotspot.gc.g1;

import java.util.ArrayList;

import java.util.List;

import java.util.Observable;

import java.util.Observer;

import sun.jvm.hotspot.debugger.Address;

import sun.jvm.hotspot.debugger.OopHandle;

import sun.jvm.hotspot.gc.shared.CompactibleSpace;

import sun.jvm.hotspot.memory.MemRegion;

import sun.jvm.hotspot.runtime.VM;

import sun.jvm.hotspot.runtime.VMObjectFactory;

import sun.jvm.hotspot.types.AddressField;

import sun.jvm.hotspot.types.CIntegerField;

import sun.jvm.hotspot.types.Type;

import sun.jvm.hotspot.types.TypeDataBase;

// Mirror class for HeapRegion. Currently we don't actually include

// any of its fields but only iterate over it.

public class HeapRegion extends CompactibleSpace {

    // static int GrainBytes;

    static private CIntegerField grainBytesField;

    static private AddressField topField;

    private static long typeFieldOffset;

    private static long pointerSize;

    private HeapRegionType type;

    static {

        VM.registerVMInitializedObserver(new Observer() {

                public void update(Observable o, Object data) {

                    initialize(VM.getVM().getTypeDataBase());

                }

            });

    }

    static private synchronized void initialize(TypeDataBase db) {

        Type type = db.lookupType("HeapRegion");

        grainBytesField = type.getCIntegerField("GrainBytes");

        topField = type.getAddressField("_top");

        typeFieldOffset = type.getField("_type").getOffset();

        pointerSize = db.lookupType("HeapRegion*").getSize();

    }

    static public long grainBytes() {

        return grainBytesField.getValue();

    }

    public HeapRegion(Address addr) {

        super(addr);

        Address typeAddr = (addr instanceof OopHandle) ? addr.addOffsetToAsOopHandle(typeFieldOffset)

                                                       : addr.addOffsetTo(typeFieldOffset);

        type = (HeapRegionType)VMObjectFactory.newObject(HeapRegionType.class, typeAddr);

    }

    public Address top() {

        return topField.getValue(addr);

    }

    @Override

    public List getLiveRegions() {

        List res = new ArrayList();

        res.add(new MemRegion(bottom(), top()));

        return res;

    }

    @Override

    public long used() {

        return top().minus(bottom());

    }

    @Override

    public long free() {

        return end().minus(top());

    }

    public boolean isFree() {

        return type.isFree();

    }

    public boolean isYoung() {

        return type.isYoung();

    }

    public boolean isHumongous() {

        return type.isHumongous();

    }

    public boolean isPinned() {

        return type.isPinned();

    }

    public boolean isOld() {

        return type.isOld();

    }

    public static long getPointerSize() {

        return pointerSize;

    }

}