/*
 * Copyright (c) 2001, 2013, 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.
 *
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#ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GENERATIONSIZER_HPP
#define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GENERATIONSIZER_HPP

#include "memory/collectorPolicy.hpp"

// There is a nice batch of tested generation sizing code in
// TwoGenerationCollectorPolicy. Lets reuse it!

class GenerationSizer : public TwoGenerationCollectorPolicy {
private:

  void trace_gen_sizes(const char* const str) {
    if (TracePageSizes) {
      tty->print_cr("%s:  " SIZE_FORMAT "," SIZE_FORMAT " "
                    SIZE_FORMAT "," SIZE_FORMAT " "
                    SIZE_FORMAT,
                    str,
                    _min_gen1_size / K, _max_gen1_size / K,
                    _min_gen0_size / K, _max_gen0_size / K,
                    _max_heap_byte_size / K);
    }
  }

public:
  GenerationSizer() {
    initialize_all();
  }

  void initialize_flags() {
    // Do basic sizing work
    TwoGenerationCollectorPolicy::initialize_flags();

    // If the user hasn't explicitly set the number of worker
    // threads, set the count.
    assert(UseSerialGC ||
           !FLAG_IS_DEFAULT(ParallelGCThreads) ||
           (ParallelGCThreads > 0),
           "ParallelGCThreads should be set before flag initialization");

    // The survivor ratio's are calculated "raw", unlike the
    // default gc, which adds 2 to the ratio value. We need to
    // make sure the values are valid before using them.
    if (MinSurvivorRatio < 3) {
      MinSurvivorRatio = 3;
    }

    if (InitialSurvivorRatio < 3) {
      InitialSurvivorRatio = 3;
    }
  }

  void initialize_size_info() {
    TwoGenerationCollectorPolicy::initialize_size_info();

    trace_gen_sizes("ps heap raw");
    const size_t page_sz = os::page_size_for_region(_min_heap_byte_size,
                                                    _max_heap_byte_size,
                                                    8);

    // Can a page size be something else than a power of two?
    assert(is_power_of_2((intptr_t)page_sz), "must be a power of 2");
    _min_alignment = round_to(page_sz, intra_heap_alignment());

    // Update sizes to reflect the selected page size.
    _min_gen0_size = align_size_up(_min_gen0_size, _min_alignment);
    _initial_gen0_size = MAX2(align_size_up_(_initial_gen0_size, _min_alignment), _min_gen0_size);
    _max_gen0_size = align_size_up(_max_gen0_size, _min_alignment);

    // Align old gen size down to preserve specified heap size. Adjust all other values.
    _max_gen1_size = max_heap_byte_size() - _max_gen0_size;
    _min_gen1_size = MIN2(align_size_up_(_min_gen1_size, _min_alignment), _max_gen1_size);
    _initial_gen1_size = MIN2(align_size_up_(_initial_gen1_size, _min_alignment), _max_gen1_size);

    trace_gen_sizes("ps heap rnd");
  }
};

#endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GENERATIONSIZER_HPP