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 * 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.memory;

import java.util.*;

import sun.jvm.hotspot.debugger.Address;

import sun.jvm.hotspot.runtime.VM;

import sun.jvm.hotspot.runtime.VMObject;

import sun.jvm.hotspot.runtime.VMObjectFactory;

import sun.jvm.hotspot.types.*;

public class FileMapInfo {

  private static FileMapHeader header;

  private static Address headerValue;

  // Fields for class FileMapHeader

  private static Address mdSpaceValue;

  private static Address mdRegionBaseAddress;

  private static Address mdRegionEndAddress;

  // HashMap created by mapping the vTable addresses in the md region with

  // the corresponding metadata type.

  private static Map<Address, Type> vTableTypeMap;

  private static Type metadataTypeArray[];

  static {

    VM.registerVMInitializedObserver(new Observer() {

        public void update(Observable o, Object data) {

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

        }

      });

  }

  private static void initialize(TypeDataBase db) {

    // FileMapInfo

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

    AddressField currentInfoField = type.getAddressField("_current_info");

    long headerFieldOffset = type.getField("_header").getOffset();

    Address headerAddress = currentInfoField.getValue().addOffsetTo(headerFieldOffset);

    headerValue = headerAddress.getAddressAt(0);

    // FileMapHeader

    type = db.lookupType("FileMapHeader");

    AddressField spaceField = type.getAddressField("_space[0]");

    Address spaceValue = headerValue.addOffsetTo(type.getField("_space[0]").getOffset());

    mdSpaceValue = spaceValue.addOffsetTo(3 * spaceField.getSize());

    // SpaceInfo

    type = db.lookupType("CDSFileMapRegion");

    mdRegionBaseAddress = (mdSpaceValue.addOffsetTo(mdRegionBaseAddressOffset)).getAddressAt(0);

    long mdRegionSizeOffset = type.getField("_used").getOffset();

    long mdRegionSize = (mdSpaceValue.addOffsetTo(mdRegionSizeOffset)).getAddressAt(0).asLongValue();

    mdRegionEndAddress = mdRegionBaseAddress.addOffsetTo(mdRegionSize);

    populateMetadataTypeArray(db);

  }

  private static void populateMetadataTypeArray(TypeDataBase db) {

    metadataTypeArray = new Type[8];

    metadataTypeArray[0] = db.lookupType("ConstantPool");

    metadataTypeArray[1] = db.lookupType("InstanceKlass");

    metadataTypeArray[2] = db.lookupType("InstanceClassLoaderKlass");

    metadataTypeArray[3] = db.lookupType("InstanceMirrorKlass");

    metadataTypeArray[4] = db.lookupType("InstanceRefKlass");

    metadataTypeArray[5] = db.lookupType("Method");

    metadataTypeArray[6] = db.lookupType("ObjArrayKlass");

    metadataTypeArray[7] = db.lookupType("TypeArrayKlass");

  }

  public FileMapHeader getHeader() {

    if (header == null) {

      header = (FileMapHeader) VMObjectFactory.newObject(FileMapInfo.FileMapHeader.class, headerValue);

    }

    return header;

  }

  public boolean inCopiedVtableSpace(Address vptrAddress) {

    FileMapHeader fmHeader = getHeader();

    return fmHeader.inCopiedVtableSpace(vptrAddress);

  }

  public Type getTypeForVptrAddress(Address vptrAddress) {

    if (vTableTypeMap == null) {

      getHeader().createVtableTypeMapping();

    }

    return vTableTypeMap.get(vptrAddress);

  }

  //------------------------------------------------------------------------------------------

  public static class FileMapHeader extends VMObject {

    public FileMapHeader(Address addr) {

      super(addr);

    }

    public boolean inCopiedVtableSpace(Address vptrAddress) {

      if (vptrAddress.greaterThan(mdRegionBaseAddress) &&

          vptrAddress.lessThanOrEqual(mdRegionEndAddress)) {

        return true;

      }

      return false;

    }

    public void createVtableTypeMapping() {

      vTableTypeMap = new HashMap<Address, Type>();

      long metadataVTableSize = 0;

      long addressSize = VM.getVM().getAddressSize();

      Address copiedVtableAddress = mdRegionBaseAddress;

      for (int i=0; i < metadataTypeArray.length; i++) {

        // The first entry denotes the vtable size.

        metadataVTableSize = copiedVtableAddress.getAddressAt(0).asLongValue();

        vTableTypeMap.put(copiedVtableAddress.addOffsetTo(addressSize), metadataTypeArray[i]);

        // The '+ 1' below is to skip the entry containing the size of this metadata's vtable.

        copiedVtableAddress =

          copiedVtableAddress.addOffsetTo((metadataVTableSize + 1) * addressSize);

      }

    }

  }

}