/*

 * 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/shared/preservedMarks.inline.hpp"

#include "memory/allocation.inline.hpp"

#include "oops/oop.inline.hpp"

void PreservedMarks::restore() {

  // First, iterate over the stack and restore all marks.

  StackIterator<OopAndMarkOop, mtGC> iter(_stack);

  while (!iter.is_empty()) {

    OopAndMarkOop elem = iter.next();

    elem.set_mark();

  }

  // Second, reclaim all the stack memory

  _stack.clear(true /* clear_cache */);

}

void RemoveForwardedPointerClosure::do_object(oop obj) {

  if (obj->is_forwarded()) {

    obj->init_mark();

  }

}

void PreservedMarksSet::init(uint num) {

  assert(_stacks == NULL && _num == 0, "do not re-initialize");

  assert(num > 0, "pre-condition");

  if (_in_c_heap) {

    _stacks = NEW_C_HEAP_ARRAY(Padded<PreservedMarks>, num, mtGC);

  } else {

    _stacks = NEW_RESOURCE_ARRAY(Padded<PreservedMarks>, num);

  }

  for (uint i = 0; i < num; i += 1) {

    ::new (_stacks + i) PreservedMarks();

  }

  _num = num;

  assert_empty();

}

void PreservedMarksSet::restore() {

  for (uint i = 0; i < _num; i += 1) {

    get(i)->restore();

  }

}

void PreservedMarksSet::reclaim() {

  assert_empty();

  for (uint i = 0; i < _num; i += 1) {

    _stacks[i].~Padded<PreservedMarks>();

  }

  if (_in_c_heap) {

    FREE_C_HEAP_ARRAY(Padded<PreservedMarks>, _stacks);

  } else {

    // the array was resource-allocated, so nothing to do

  }

  _stacks = NULL;

  _num = 0;

}

#ifndef PRODUCT

void PreservedMarksSet::assert_empty() {

  assert(_stacks != NULL && _num > 0, "should have been initialized");

  for (uint i = 0; i < _num; i += 1) {

    assert(get(i)->is_empty(), "stack should be empty");

  }

}

#endif // ndef PRODUCT