/*

 * Copyright (c) 2001, 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

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 */

#ifndef SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP

#define SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP

#include "gc/shared/barrierSet.hpp"

#include "gc/shared/cardTableRS.hpp"

#include "gc/shared/generationSpec.hpp"

#include "memory/allocation.hpp"

#include "utilities/macros.hpp"

// This class (or more correctly, subtypes of this class)

// are used to define global garbage collector attributes.

// This includes initialization of generations and any other

// shared resources they may need.

//

// In general, all flag adjustment and validation should be

// done in initialize_flags(), which is called prior to

// initialize_size_info().

//

// This class is not fully developed yet. As more collector(s)

// are added, it is expected that we will come across further

// behavior that requires global attention. The correct place

// to deal with those issues is this class.

// Forward declarations.

class GenCollectorPolicy;

class AdaptiveSizePolicy;

#if INCLUDE_ALL_GCS

class ConcurrentMarkSweepPolicy;

class G1CollectorPolicy;

#endif // INCLUDE_ALL_GCS

class GCPolicyCounters;

class MarkSweepPolicy;

class CollectorPolicy : public CHeapObj<mtGC> {

 protected:

  virtual void initialize_alignments() = 0;

  virtual void initialize_flags();

  virtual void initialize_size_info();

  DEBUG_ONLY(virtual void assert_flags();)

  DEBUG_ONLY(virtual void assert_size_info();)

  size_t _initial_heap_byte_size;

  size_t _max_heap_byte_size;

  size_t _min_heap_byte_size;

  size_t _space_alignment;

  size_t _heap_alignment;

  CollectorPolicy();

 public:

  virtual void initialize_all() {

    initialize_alignments();

    initialize_flags();

    initialize_size_info();

  }

  // Return maximum heap alignment that may be imposed by the policy.

  static size_t compute_heap_alignment();

  size_t space_alignment()        { return _space_alignment; }

  size_t heap_alignment()         { return _heap_alignment; }

  size_t initial_heap_byte_size() { return _initial_heap_byte_size; }

  size_t max_heap_byte_size()     { return _max_heap_byte_size; }

  size_t min_heap_byte_size()     { return _min_heap_byte_size; }

};

class GenCollectorPolicy : public CollectorPolicy {

  friend class TestGenCollectorPolicy;

  friend class VMStructs;

protected:

  size_t _min_young_size;

  size_t _initial_young_size;

  size_t _max_young_size;

  size_t _min_old_size;

  size_t _initial_old_size;

  size_t _max_old_size;

  // _gen_alignment and _space_alignment will have the same value most of the

  // time. When using large pages they can differ.

  size_t _gen_alignment;

  GenerationSpec* _young_gen_spec;

  GenerationSpec* _old_gen_spec;

  GCPolicyCounters* _gc_policy_counters;

  // The sizing of the heap is controlled by a sizing policy.

  AdaptiveSizePolicy* _size_policy;

  void initialize_flags();

  void initialize_size_info();

  DEBUG_ONLY(void assert_flags();)

  DEBUG_ONLY(void assert_size_info();)

  // Compute max heap alignment.

  size_t compute_max_alignment();

  // Scale the base_size by NewRatio according to

  //     result = base_size / (NewRatio + 1)

  // and align by min_alignment()

  size_t scale_by_NewRatio_aligned(size_t base_size);

  // Bound the value by the given maximum minus the min_alignment.

  size_t bound_minus_alignment(size_t desired_size, size_t maximum_size);

 public:

  GenCollectorPolicy();

  // Accessors

  size_t min_young_size()     { return _min_young_size; }

  size_t initial_young_size() { return _initial_young_size; }

  size_t max_young_size()     { return _max_young_size; }

  size_t gen_alignment()      { return _gen_alignment; }

  size_t min_old_size()       { return _min_old_size; }

  size_t initial_old_size()   { return _initial_old_size; }

  size_t max_old_size()       { return _max_old_size; }

  GenerationSpec* young_gen_spec() const {

    assert(_young_gen_spec != NULL, "_young_gen_spec should have been initialized");

    return _young_gen_spec;

  }

  GenerationSpec* old_gen_spec() const {

    assert(_old_gen_spec != NULL, "_old_gen_spec should have been initialized");

    return _old_gen_spec;

  }

  // Performance Counter support

  GCPolicyCounters* counters()     { return _gc_policy_counters; }

  // Create the jstat counters for the GC policy.

  virtual void initialize_gc_policy_counters() = 0;

  virtual void initialize_generations() { };

  virtual void initialize_all() {

    CollectorPolicy::initialize_all();

    initialize_generations();

  }

  size_t young_gen_size_lower_bound();

  size_t old_gen_size_lower_bound();

  // Adaptive size policy

  AdaptiveSizePolicy* size_policy() { return _size_policy; }

  virtual void initialize_size_policy(size_t init_eden_size,

                                      size_t init_promo_size,

                                      size_t init_survivor_size);

};

class MarkSweepPolicy : public GenCollectorPolicy {

 protected:

  void initialize_alignments();

  void initialize_generations();

 public:

  MarkSweepPolicy() {}

  void initialize_gc_policy_counters();

};

#endif // SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP