/*

 * 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/parallel/generationSizer.hpp"

#include "gc/shared/collectorPolicy.hpp"

#include "runtime/globals_extension.hpp"

#include "utilities/globalDefinitions.hpp"

void GenerationSizer::initialize_alignments() {

  _space_alignment = _gen_alignment = default_gen_alignment();

  _heap_alignment = compute_heap_alignment();

}

void GenerationSizer::initialize_flags() {

  // Do basic sizing work

  GenCollectorPolicy::initialize_flags();

  // 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) {

    FLAG_SET_ERGO(uintx, MinSurvivorRatio, 3);

  }

  if (InitialSurvivorRatio < 3) {

    FLAG_SET_ERGO(uintx, InitialSurvivorRatio, 3);

  }

}

void GenerationSizer::initialize_size_info() {

  const size_t max_page_sz = os::page_size_for_region_aligned(_max_heap_byte_size, 8);

  const size_t min_pages = 4; // 1 for eden + 1 for each survivor + 1 for old

  const size_t min_page_sz = os::page_size_for_region_aligned(_min_heap_byte_size, min_pages);

  const size_t page_sz = MIN2(max_page_sz, min_page_sz);

  // 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");

  if (new_alignment != _gen_alignment) {

    _gen_alignment = new_alignment;

    _space_alignment = new_alignment;

    // Redo everything from the start

    initialize_flags();

  }

  GenCollectorPolicy::initialize_size_info();

}