/*

 * Copyright (c) 2000, 2015, 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.

 *

 */

import java.io.*;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.runtime.*;

import sun.jvm.hotspot.types.*;

import sun.jvm.hotspot.utilities.*;

public class GenCollectedHeap extends CollectedHeap {

  private static AddressField youngGenField;

  private static AddressField oldGenField;

  private static AddressField youngGenSpecField;

  private static AddressField oldGenSpecField;

  private static GenerationFactory genFactory;

  static {

    VM.registerVMInitializedObserver(new Observer() {

        public void update(Observable o, Object data) {

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

        }

      });

  }

  private static synchronized void initialize(TypeDataBase db) {

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

    youngGenField = type.getAddressField("_young_gen");

    oldGenField = type.getAddressField("_old_gen");

    genFactory = new GenerationFactory();

    Type collectorPolicyType = db.lookupType("GenCollectorPolicy");

    youngGenSpecField = collectorPolicyType.getAddressField("_young_gen_spec");

    oldGenSpecField = collectorPolicyType.getAddressField("_old_gen_spec");

  }

  public GenCollectedHeap(Address addr) {

    super(addr);

  }

  public int nGens() {

    return 2; // Young + Old

  }

  public Generation getGen(int i) {

    if (Assert.ASSERTS_ENABLED) {

      Assert.that((i == 0) || (i == 1), "Index " + i +

                  " out of range (should be 0 or 1)");

    }

    switch (i) {

    case 0:

      return genFactory.newObject(youngGenField.getValue(addr));

    case 1:

      return genFactory.newObject(oldGenField.getValue(addr));

    default:

      // no generation for i, and assertions disabled.

      return null;

    }

  }

  public boolean isIn(Address a) {

    for (int i = 0; i < nGens(); i++) {

      Generation gen = getGen(i);

      if (gen.isIn(a)) {

        return true;

      }

    }

    return false;

  }

  public long capacity() {

    long capacity = 0;

    for (int i = 0; i < nGens(); i++) {

      capacity += getGen(i).capacity();

    }

    return capacity;

  }

  public long used() {

    long used = 0;

    for (int i = 0; i < nGens(); i++) {

      used += getGen(i).used();

    }

    return used;

  }

  /** Package-private access to GenerationSpecs */

  GenerationSpec spec(int level) {

    if (Assert.ASSERTS_ENABLED) {

      Assert.that((level == 0) || (level == 1), "Index " + level +

                  " out of range (should be 0 or 1)");

    }

    if ((level != 0) && (level != 1)) {

      return null;

    }

    if (level == 0) {

      return (GenerationSpec)

              VMObjectFactory.newObject(GenerationSpec.class,

                      youngGenSpecField.getAddress());

    } else {

      return (GenerationSpec)

              VMObjectFactory.newObject(GenerationSpec.class,

                      oldGenSpecField.getAddress());

    }

  }

  public CollectedHeapName kind() {

    return CollectedHeapName.GEN_COLLECTED_HEAP;

  }

  public void printOn(PrintStream tty) {

    for (int i = 0; i < nGens(); i++) {

      tty.print("Gen " + i + ": ");

      getGen(i).printOn(tty);

      tty.println("Invocations: " + getGen(i).invocations());

      tty.println();

    }

  }

}