/*

 * Copyright (c) 1997, 2016, 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.

 *

 */

#ifndef SHARE_VM_GC_SHARED_AGETABLE_HPP

#define SHARE_VM_GC_SHARED_AGETABLE_HPP

#include "oops/markOop.hpp"

#include "oops/oop.hpp"

#include "runtime/perfData.hpp"

/* Copyright (c) 1992, 2016, Oracle and/or its affiliates, and Stanford University.

   See the LICENSE file for license information. */

// Age table for adaptive feedback-mediated tenuring (scavenging)

//

// Note: all sizes are in oops

class AgeTable VALUE_OBJ_CLASS_SPEC {

  friend class VMStructs;

 public:

  // constants

  enum { table_size = markOopDesc::max_age + 1 };

  // instance variables

  size_t sizes[table_size];

  // constructor.  "global" indicates that this is the global age table

  // (as opposed to gc-thread-local)

  AgeTable(bool global = true);

  // clear table

  void clear();

  // add entry

  inline void add(oop p, size_t oop_size);

  void add(uint age, size_t oop_size) {

    assert(age > 0 && age < table_size, "invalid age of object");

    sizes[age] += oop_size;

  }

  // Merge another age table with the current one.  Used

  // for parallel young generation gc.

  void merge(AgeTable* subTable);

  // Calculate new tenuring threshold based on age information.

  uint compute_tenuring_threshold(size_t desired_survivor_size);

  void print_age_table(uint tenuring_threshold);

 private:

  PerfVariable* _perf_sizes[table_size];

};

#endif // SHARE_VM_GC_SHARED_AGETABLE_HPP