/*

 * Copyright (c) 2000, 2018, 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.

 *

 */

package sun.jvm.hotspot.memory;

import java.io.PrintStream;

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.cms.CMSHeap;

import sun.jvm.hotspot.gc.epsilon.EpsilonHeap;

import sun.jvm.hotspot.gc.g1.G1CollectedHeap;

import sun.jvm.hotspot.gc.parallel.ParallelScavengeHeap;

import sun.jvm.hotspot.gc.serial.SerialHeap;

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

import sun.jvm.hotspot.gc.z.ZCollectedHeap;

import sun.jvm.hotspot.oops.Oop;

import sun.jvm.hotspot.runtime.BasicType;

import sun.jvm.hotspot.runtime.VM;

import sun.jvm.hotspot.runtime.VirtualConstructor;

import sun.jvm.hotspot.types.AddressField;

import sun.jvm.hotspot.types.CIntegerField;

import sun.jvm.hotspot.types.Type;

import sun.jvm.hotspot.types.TypeDataBase;

public class Universe {

  private static AddressField collectedHeapField;

  private static VirtualConstructor heapConstructor;

  private static sun.jvm.hotspot.types.OopField mainThreadGroupField;

  private static sun.jvm.hotspot.types.OopField systemThreadGroupField;

  private static AddressField narrowOopBaseField;

  private static CIntegerField narrowOopShiftField;

  private static AddressField narrowKlassBaseField;

  private static CIntegerField narrowKlassShiftField;

  public enum NARROW_OOP_MODE {

    UnscaledNarrowOop,

    ZeroBasedNarrowOop,

    HeapBasedNarrowOop

  }

  static {

    VM.registerVMInitializedObserver(new Observer() {

        public void update(Observable o, Object data) {

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

        }

      });

  }

  private static boolean typeExists(TypeDataBase db, String type) {

      try {

          db.lookupType(type);

      } catch (RuntimeException e) {

          return false;

      }

      return true;

  }

  private static void addHeapTypeIfInDB(TypeDataBase db, Class heapClass) {

      String heapName = heapClass.getSimpleName();

      if (typeExists(db, heapName)) {

          heapConstructor.addMapping(heapName, heapClass);

      }

  }

  private static synchronized void initialize(TypeDataBase db) {

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

    collectedHeapField = type.getAddressField("_collectedHeap");

    heapConstructor = new VirtualConstructor(db);

    addHeapTypeIfInDB(db, CMSHeap.class);

    addHeapTypeIfInDB(db, SerialHeap.class);

    addHeapTypeIfInDB(db, ParallelScavengeHeap.class);

    addHeapTypeIfInDB(db, G1CollectedHeap.class);

    addHeapTypeIfInDB(db, EpsilonHeap.class);

    addHeapTypeIfInDB(db, ZCollectedHeap.class);

    mainThreadGroupField   = type.getOopField("_main_thread_group");

    systemThreadGroupField = type.getOopField("_system_thread_group");

    narrowOopBaseField = type.getAddressField("_narrow_oop._base");

    narrowOopShiftField = type.getCIntegerField("_narrow_oop._shift");

    narrowKlassBaseField = type.getAddressField("_narrow_klass._base");

    narrowKlassShiftField = type.getCIntegerField("_narrow_klass._shift");

    UniverseExt.initialize(heapConstructor);

  }

  public Universe() {

  }

  public static String narrowOopModeToString(NARROW_OOP_MODE mode) {

    switch (mode) {

    case UnscaledNarrowOop:

      return "32-bits Oops";

    case ZeroBasedNarrowOop:

      return "zero based Compressed Oops";

    case HeapBasedNarrowOop:

      return "Compressed Oops with base";

    }

    return "";

  }

  public CollectedHeap heap() {

    return (CollectedHeap) heapConstructor.instantiateWrapperFor(collectedHeapField.getValue());

  }

  public static long getNarrowOopBase() {

    if (narrowOopBaseField.getValue() == null) {

      return 0;

    } else {

      return narrowOopBaseField.getValue().minus(null);

    }

  }

  public static int getNarrowOopShift() {

    return (int)narrowOopShiftField.getValue();

  }

  public static long getNarrowKlassBase() {

    if (narrowKlassBaseField.getValue() == null) {

      return 0;

    } else {

      return narrowKlassBaseField.getValue().minus(null);

    }

  }

  public static int getNarrowKlassShift() {

    return (int)narrowKlassShiftField.getValue();

  }

  /** Returns "TRUE" iff "p" points into the allocated area of the heap. */

  public boolean isIn(Address p) {

    return heap().isIn(p);

  }

  /** Returns "TRUE" iff "p" points into the reserved area of the heap. */

  public boolean isInReserved(Address p) {

    return heap().isInReserved(p);

  }

  private Oop newOop(OopHandle handle) {

    return VM.getVM().getObjectHeap().newOop(handle);

  }

  public Oop mainThreadGroup() {

    return newOop(mainThreadGroupField.getValue());

  }

  public Oop systemThreadGroup() {

    return newOop(systemThreadGroupField.getValue());

  }

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

  public void printOn(PrintStream tty) {

    heap().printOn(tty);

  }

  // Check whether an element of a typeArrayOop with the given type must be

  // aligned 0 mod 8.  The typeArrayOop itself must be aligned at least this

  // strongly.

  public static boolean elementTypeShouldBeAligned(BasicType type) {

    return type == BasicType.T_DOUBLE || type == BasicType.T_LONG;

  }

  // Check whether an object field (static/non-static) of the given type must be

  // aligned 0 mod 8.

  public static boolean fieldTypeShouldBeAligned(BasicType type) {

    return type == BasicType.T_DOUBLE || type == BasicType.T_LONG;

  }

}