/*

 * Copyright (c) 2001, 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.

 *

 */

#include "precompiled.hpp"

#include "gc/g1/g1CollectedHeap.inline.hpp"

#include "gc/g1/g1Predictions.hpp"

#include "gc/g1/heapRegion.hpp"

#include "gc/g1/survRateGroup.hpp"

#include "memory/allocation.hpp"

SurvRateGroup::SurvRateGroup(G1Predictions* predictor,

                             const char* name,

                             size_t summary_surv_rates_len) :

    _predictor(predictor), _name(name),

    _summary_surv_rates_len(summary_surv_rates_len),

    _summary_surv_rates_max_len(0),

    _summary_surv_rates(NULL),

    _surv_rate(NULL),

    _accum_surv_rate_pred(NULL),

    _surv_rate_pred(NULL),

    _stats_arrays_length(0) {

  reset();

  if (summary_surv_rates_len > 0) {

    size_t length = summary_surv_rates_len;

      _summary_surv_rates = NEW_C_HEAP_ARRAY(NumberSeq*, length, mtGC);

    for (size_t i = 0; i < length; ++i) {

      _summary_surv_rates[i] = new NumberSeq();

    }

  }

  start_adding_regions();

}

double SurvRateGroup::get_new_prediction(TruncatedSeq const* seq) const {

  return _predictor->get_new_prediction(seq);

}

void SurvRateGroup::reset() {

  _all_regions_allocated = 0;

  _setup_seq_num         = 0;

  _last_pred             = 0.0;

  // the following will set up the arrays with length 1

  _region_num            = 1;

  // The call to stop_adding_regions() will use "new" to refill

  // the _surv_rate_pred array, so we need to make sure to call

  // "delete".

  for (size_t i = 0; i < _stats_arrays_length; ++i) {

    delete _surv_rate_pred[i];

  }

  _stats_arrays_length = 0;

  stop_adding_regions();

  guarantee( _stats_arrays_length == 1, "invariant" );

  guarantee( _surv_rate_pred[0] != NULL, "invariant" );

  _surv_rate_pred[0]->add(0.4);

  all_surviving_words_recorded(false);

  _region_num = 0;

}

void SurvRateGroup::start_adding_regions() {

  _setup_seq_num   = _stats_arrays_length;

  _region_num      = 0;

}

void SurvRateGroup::stop_adding_regions() {

  if (_region_num > _stats_arrays_length) {

    double* old_surv_rate = _surv_rate;

    double* old_accum_surv_rate_pred = _accum_surv_rate_pred;

    TruncatedSeq** old_surv_rate_pred = _surv_rate_pred;

    _surv_rate = NEW_C_HEAP_ARRAY(double, _region_num, mtGC);

    _accum_surv_rate_pred = NEW_C_HEAP_ARRAY(double, _region_num, mtGC);

    _surv_rate_pred = NEW_C_HEAP_ARRAY(TruncatedSeq*, _region_num, mtGC);

    for (size_t i = 0; i < _stats_arrays_length; ++i) {

      _surv_rate_pred[i] = old_surv_rate_pred[i];

    }

    for (size_t i = _stats_arrays_length; i < _region_num; ++i) {

      _surv_rate_pred[i] = new TruncatedSeq(10);

    }

    _stats_arrays_length = _region_num;

    if (old_surv_rate != NULL) {

      FREE_C_HEAP_ARRAY(double, old_surv_rate);

    }

    if (old_accum_surv_rate_pred != NULL) {

      FREE_C_HEAP_ARRAY(double, old_accum_surv_rate_pred);

    }

    if (old_surv_rate_pred != NULL) {

      FREE_C_HEAP_ARRAY(TruncatedSeq*, old_surv_rate_pred);

    }

  }

  for (size_t i = 0; i < _stats_arrays_length; ++i) {

    _surv_rate[i] = 0.0;

  }

}

int SurvRateGroup::next_age_index() {

  ++_region_num;

  return (int) ++_all_regions_allocated;

}

void SurvRateGroup::record_surviving_words(int age_in_group, size_t surv_words) {

  guarantee( 0 <= age_in_group && (size_t) age_in_group < _region_num,

             "pre-condition" );

  guarantee( _surv_rate[age_in_group] <= 0.00001,

             "should only update each slot once" );

  double surv_rate = (double) surv_words / (double) HeapRegion::GrainWords;

  _surv_rate[age_in_group] = surv_rate;

  _surv_rate_pred[age_in_group]->add(surv_rate);

  if ((size_t)age_in_group < _summary_surv_rates_len) {

    _summary_surv_rates[age_in_group]->add(surv_rate);

    if ((size_t)(age_in_group+1) > _summary_surv_rates_max_len)

      _summary_surv_rates_max_len = age_in_group+1;

  }

}

void SurvRateGroup::all_surviving_words_recorded(bool update_predictors) {

  if (update_predictors && _region_num > 0) { // conservative

    double surv_rate = _surv_rate_pred[_region_num-1]->last();

    for (size_t i = _region_num; i < _stats_arrays_length; ++i) {

      guarantee( _surv_rate[i] <= 0.00001,

                 "the slot should not have been updated" );

      _surv_rate_pred[i]->add(surv_rate);

    }

  }

  double accum = 0.0;

  double pred = 0.0;

  for (size_t i = 0; i < _stats_arrays_length; ++i) {

    pred = get_new_prediction(_surv_rate_pred[i]);

    if (pred > 1.0) pred = 1.0;

    accum += pred;

    _accum_surv_rate_pred[i] = accum;

  }

  _last_pred = pred;

}

#ifndef PRODUCT

void SurvRateGroup::print() {

  gclog_or_tty->print_cr("Surv Rate Group: %s (" SIZE_FORMAT " entries)",

                _name, _region_num);

  for (size_t i = 0; i < _region_num; ++i) {

    gclog_or_tty->print_cr("    age " SIZE_FORMAT_W(4) "   surv rate %6.2lf %%   pred %6.2lf %%",

                           i, _surv_rate[i] * 100.0,

                           _predictor->get_new_prediction(_surv_rate_pred[i]) * 100.0);

  }

}

void

SurvRateGroup::print_surv_rate_summary() {

  size_t length = _summary_surv_rates_max_len;

  if (length == 0)

    return;

  gclog_or_tty->cr();

  gclog_or_tty->print_cr("%s Rate Summary (for up to age " SIZE_FORMAT ")", _name, length-1);

  gclog_or_tty->print_cr("      age range     survival rate (avg)      samples (avg)");

  gclog_or_tty->print_cr("  ---------------------------------------------------------");

  size_t index = 0;

  size_t limit = MIN2((int) length, 10);

  while (index < limit) {

    gclog_or_tty->print_cr("           " SIZE_FORMAT_W(4)

                           "                 %6.2lf%%             %6.2lf",

                           index, _summary_surv_rates[index]->avg() * 100.0,

                           (double) _summary_surv_rates[index]->num());

    ++index;

  }

  gclog_or_tty->print_cr("  ---------------------------------------------------------");

  int num = 0;

  double sum = 0.0;

  int samples = 0;

  while (index < length) {

    ++num;

    sum += _summary_surv_rates[index]->avg() * 100.0;

    samples += _summary_surv_rates[index]->num();

    ++index;

    if (index == length || num % 10 == 0) {

      gclog_or_tty->print_cr("   " SIZE_FORMAT_W(4) " .. " SIZE_FORMAT_W(4)

                             "                 %6.2lf%%             %6.2lf",

                             (index-1) / 10 * 10, index-1, sum / (double) num,

                             (double) samples / (double) num);

      sum = 0.0;

      num = 0;

      samples = 0;

    }

  }

  gclog_or_tty->print_cr("  ---------------------------------------------------------");

}

#endif // PRODUCT