/*

 * 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 "gc/g1/heapRegionSet.hpp"

inline void HeapRegionSetBase::add(HeapRegion* hr) {

  check_mt_safety();

  assert_heap_region_set(hr->containing_set() == NULL, "should not already have a containing set");

  assert_heap_region_set(hr->next() == NULL, "should not already be linked");

  assert_heap_region_set(hr->prev() == NULL, "should not already be linked");

  _length++;

  hr->set_containing_set(this);

  verify_region(hr);

}

inline void HeapRegionSetBase::remove(HeapRegion* hr) {

  check_mt_safety();

  verify_region(hr);

  assert_heap_region_set(hr->next() == NULL, "should already be unlinked");

  assert_heap_region_set(hr->prev() == NULL, "should already be unlinked");

  hr->set_containing_set(NULL);

  assert_heap_region_set(_length > 0, "pre-condition");

  _length--;

}

inline void FreeRegionList::add_ordered(HeapRegion* hr) {

  assert_free_region_list((length() == 0 && _head == NULL && _tail == NULL && _last == NULL) ||

                          (length() >  0 && _head != NULL && _tail != NULL),

                          "invariant");

  // add() will verify the region and check mt safety.

  add(hr);

  // Now link the region

  if (_head != NULL) {

    HeapRegion* curr;

    if (_last != NULL && _last->hrm_index() < hr->hrm_index()) {

      curr = _last;

    } else {

      curr = _head;

    }

    // Find first entry with a Region Index larger than entry to insert.

    while (curr != NULL && curr->hrm_index() < hr->hrm_index()) {

      curr = curr->next();

    }

    hr->set_next(curr);

    if (curr == NULL) {

      // Adding at the end

      hr->set_prev(_tail);

      _tail->set_next(hr);

      _tail = hr;

    } else if (curr->prev() == NULL) {

      // Adding at the beginning

      hr->set_prev(NULL);

      _head = hr;

      curr->set_prev(hr);

    } else {

      hr->set_prev(curr->prev());

      hr->prev()->set_next(hr);

      curr->set_prev(hr);

    }

  } else {

    // The list was empty

    _tail = hr;

    _head = hr;

  }

  _last = hr;

}

inline HeapRegion* FreeRegionList::remove_from_head_impl() {

  HeapRegion* result = _head;

  _head = result->next();

  if (_head == NULL) {

    _tail = NULL;

  } else {

    _head->set_prev(NULL);

  }

  result->set_next(NULL);

  return result;

}

inline HeapRegion* FreeRegionList::remove_from_tail_impl() {

  HeapRegion* result = _tail;

  _tail = result->prev();

  if (_tail == NULL) {

    _head = NULL;

  } else {

    _tail->set_next(NULL);

  }

  result->set_prev(NULL);

  return result;

}

inline HeapRegion* FreeRegionList::remove_region(bool from_head) {

  check_mt_safety();

  verify_optional();

  if (is_empty()) {

    return NULL;

  }

  assert_free_region_list(length() > 0 && _head != NULL && _tail != NULL, "invariant");

  HeapRegion* hr;

  if (from_head) {

    hr = remove_from_head_impl();

  } else {

    hr = remove_from_tail_impl();

  }

  if (_last == hr) {

    _last = NULL;

  }

  // remove() will verify the region and check mt safety.

  remove(hr);

  return hr;

}