/*

 * Copyright (c) 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.

 *

 */

#include "precompiled.hpp"

#include "gc/g1/g1YoungGenSizer.hpp"

#include "gc/g1/heapRegion.hpp"

#include "logging/log.hpp"

G1YoungGenSizer::G1YoungGenSizer() : _sizer_kind(SizerDefaults),

  _min_desired_young_length(0), _max_desired_young_length(0), _adaptive_size(true) {

  if (FLAG_IS_CMDLINE(NewRatio)) {

    if (FLAG_IS_CMDLINE(NewSize) || FLAG_IS_CMDLINE(MaxNewSize)) {

      log_warning(gc, ergo)("-XX:NewSize and -XX:MaxNewSize override -XX:NewRatio");

    } else {

      _sizer_kind = SizerNewRatio;

      _adaptive_size = false;

      return;

    }

  }

  if (NewSize > MaxNewSize) {

    if (FLAG_IS_CMDLINE(MaxNewSize)) {

      log_warning(gc, ergo)("NewSize (" SIZE_FORMAT "k) is greater than the MaxNewSize (" SIZE_FORMAT "k). "

                            "A new max generation size of " SIZE_FORMAT "k will be used.",

                            NewSize/K, MaxNewSize/K, NewSize/K);

    }

    FLAG_SET_ERGO(size_t, MaxNewSize, NewSize);

  }

  if (FLAG_IS_CMDLINE(NewSize)) {

    _min_desired_young_length = MAX2((uint) (NewSize / HeapRegion::GrainBytes),

                                     1U);

    if (FLAG_IS_CMDLINE(MaxNewSize)) {

      _max_desired_young_length =

                             MAX2((uint) (MaxNewSize / HeapRegion::GrainBytes),

                                  1U);

      _sizer_kind = SizerMaxAndNewSize;

      _adaptive_size = _min_desired_young_length != _max_desired_young_length;

    } else {

      _sizer_kind = SizerNewSizeOnly;

    }

  } else if (FLAG_IS_CMDLINE(MaxNewSize)) {

    _max_desired_young_length =

                             MAX2((uint) (MaxNewSize / HeapRegion::GrainBytes),

                                  1U);

    _sizer_kind = SizerMaxNewSizeOnly;

  }

}

uint G1YoungGenSizer::calculate_default_min_length(uint new_number_of_heap_regions) {

  uint default_value = (new_number_of_heap_regions * G1NewSizePercent) / 100;

  return MAX2(1U, default_value);

}

uint G1YoungGenSizer::calculate_default_max_length(uint new_number_of_heap_regions) {

  uint default_value = (new_number_of_heap_regions * G1MaxNewSizePercent) / 100;

  return MAX2(1U, default_value);

}

void G1YoungGenSizer::recalculate_min_max_young_length(uint number_of_heap_regions, uint* min_young_length, uint* max_young_length) {

  assert(number_of_heap_regions > 0, "Heap must be initialized");

  switch (_sizer_kind) {

    case SizerDefaults:

      *min_young_length = calculate_default_min_length(number_of_heap_regions);

      *max_young_length = calculate_default_max_length(number_of_heap_regions);

      break;

    case SizerNewSizeOnly:

      *max_young_length = calculate_default_max_length(number_of_heap_regions);

      *max_young_length = MAX2(*min_young_length, *max_young_length);

      break;

    case SizerMaxNewSizeOnly:

      *min_young_length = calculate_default_min_length(number_of_heap_regions);

      *min_young_length = MIN2(*min_young_length, *max_young_length);

      break;

    case SizerMaxAndNewSize:

      // Do nothing. Values set on the command line, don't update them at runtime.

      break;

    case SizerNewRatio:

      *min_young_length = number_of_heap_regions / (NewRatio + 1);

      *max_young_length = *min_young_length;

      break;

    default:

      ShouldNotReachHere();

  }

  assert(*min_young_length <= *max_young_length, "Invalid min/max young gen size values");

}

void G1YoungGenSizer::adjust_max_new_size(uint number_of_heap_regions) {

  // We need to pass the desired values because recalculation may not update these

  // values in some cases.

  uint temp = _min_desired_young_length;

  uint result = _max_desired_young_length;

  recalculate_min_max_young_length(number_of_heap_regions, &temp, &result);

  size_t max_young_size = result * HeapRegion::GrainBytes;

  if (max_young_size != MaxNewSize) {

    FLAG_SET_ERGO(size_t, MaxNewSize, max_young_size);

  }

}

void G1YoungGenSizer::heap_size_changed(uint new_number_of_heap_regions) {

  recalculate_min_max_young_length(new_number_of_heap_regions, &_min_desired_young_length,

          &_max_desired_young_length);

}