/*

 * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

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 */

package sun.jvm.hotspot.oops;

import java.io.*;

import java.util.*;

import sun.jvm.hotspot.utilities.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.runtime.*;

import sun.jvm.hotspot.types.*;

// Oop represents the superclass for all types of

// objects in the HotSpot object heap.

public class Oop {

  static {

    VM.registerVMInitializedObserver(new Observer() {

        public void update(Observable o, Object data) {

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

        }

      });

  }

  private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {

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

    mark       = new CIntField(type.getCIntegerField("_mark"), 0);

    klass      = new MetadataField(type.getAddressField("_metadata._klass"), 0);

    compressedKlass  = new NarrowKlassField(type.getAddressField("_metadata._compressed_klass"), 0);

    headerSize = type.getSize();

  }

  private OopHandle  handle;

  private ObjectHeap heap;

  Oop(OopHandle handle, ObjectHeap heap) {

    this.handle = handle;

    this.heap   = heap;

  }

  ObjectHeap getHeap()   { return heap; }

  /** Should not be used or needed by most clients outside this

      package; is needed, however, by {@link

      sun.jvm.hotspot.utilities.MarkBits}. */

  public OopHandle getHandle() { return handle; }

  private static long headerSize;

  public  static long getHeaderSize() { return headerSize; } // Header size in bytes.

  private static CIntField mark;

  private static MetadataField  klass;

  private static NarrowKlassField compressedKlass;

  // Accessors for declared fields

  public Mark  getMark()   { return new Mark(getHandle()); }

  public Klass getKlass() {

    if (VM.getVM().isCompressedKlassPointersEnabled()) {

      return (Klass)compressedKlass.getValue(getHandle());

    } else {

      return (Klass)klass.getValue(getHandle());

    }

  }

  public boolean isA(Klass k) {

    return getKlass().isSubtypeOf(k);

  }

  // Returns the byte size of this object

  public long getObjectSize() {

    Klass k = getKlass();

    // All other types should be overriding getObjectSize directly

    return ((InstanceKlass)k).getObjectSize(this);

  }

  // Type test operations

  public boolean isInstance()          { return false; }

  public boolean isInstanceRef()       { return false; }

  public boolean isArray()             { return false; }

  public boolean isObjArray()          { return false; }

  public boolean isTypeArray()         { return false; }

  public boolean isThread()            { return false; }

  // Align the object size.

  public static long alignObjectSize(long size) {

    return VM.getVM().alignUp(size, VM.getVM().getMinObjAlignmentInBytes());

  }

  // All vm's align longs, so pad out certain offsets.

  public static long alignObjectOffset(long offset) {

    return VM.getVM().alignUp(offset, VM.getVM().getBytesPerLong());

  }

  public boolean equals(Object obj) {

    if (obj != null && (obj instanceof Oop)) {

      return getHandle().equals(((Oop) obj).getHandle());

    }

    return false;

 }

  public int hashCode() { return getHandle().hashCode(); }

  /** Identity hash in the target VM */

  public long identityHash() {

    Mark mark = getMark();

    if (mark.isUnlocked() && (!mark.hasNoHash())) {

      return (int) mark.hash();

    } else if (mark.isMarked()) {

      return (int) mark.hash();

    } else {

      return slowIdentityHash();

    }

  }

  public long slowIdentityHash() {

    return VM.getVM().getObjectSynchronizer().identityHashValueFor(this);

  }

  public void iterate(OopVisitor visitor, boolean doVMFields) {

    visitor.setObj(this);

    visitor.prologue();

    iterateFields(visitor, doVMFields);

    visitor.epilogue();

  }

  void iterateFields(OopVisitor visitor, boolean doVMFields) {

    if (doVMFields) {

      visitor.doCInt(mark, true);

      if (VM.getVM().isCompressedKlassPointersEnabled()) {

        visitor.doMetadata(compressedKlass, true);

      } else {

        visitor.doMetadata(klass, true);

      }

    }

  }

  public void print()      { printOn(System.out); }

  public void printValue() { printValueOn(System.out); }

  public void printRaw()   { printRawOn(System.out); }

  public static void printOopValueOn(Oop obj, PrintStream tty) {

    if (obj == null) {

      tty.print("null");

    } else {

      obj.printValueOn(tty);

      tty.print(" @ " + VM.getVM().getUniverse().heap().oopAddressDescription(obj.getHandle()));

    }

  }

  public static void printOopAddressOn(Oop obj, PrintStream tty) {

    if (obj == null) {

      tty.print("null");

    } else {

      tty.print(obj.getHandle().toString());

    }

  }

  public void printOn(PrintStream tty) {

    OopPrinter printer = new OopPrinter(tty);

    iterate(printer, true);

  }

  public void printValueOn(PrintStream tty) {

    try {

      tty.print("Oop for " + getKlass().getName().asString());

    } catch (java.lang.NullPointerException e) {

      tty.print("Oop");

    }

  }

  public void printRawOn(PrintStream tty) {

    tty.print("Dumping raw memory for ");

    printValueOn(tty);

    tty.println();

    long size = getObjectSize() * 4;

    for (long i = 0; i < size; i += 4) {

      long memVal = getHandle().getCIntegerAt(i, 4, true);

      tty.println(Long.toHexString(memVal));

    }

  }

  public boolean verify() { return true;}

  public static Klass getKlassForOopHandle(OopHandle handle) {

    if (handle == null) {

      return null;

    }

    if (VM.getVM().isCompressedKlassPointersEnabled()) {

      return (Klass)Metadata.instantiateWrapperFor(handle.getCompKlassAddressAt(compressedKlass.getOffset()));

    } else {

      return (Klass)Metadata.instantiateWrapperFor(handle.getAddressAt(klass.getOffset()));

    }

  }

};