/*

 * 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 "classfile/classLoaderData.hpp"

#include "gc/shared/cardTableRS.hpp"

#include "gc/shared/genRemSet.hpp"

#include "oops/klass.hpp"

// This kind of "BarrierSet" allows a "CollectedHeap" to detect and

// enumerate ref fields that have been modified (since the last

// enumeration.)

uintx GenRemSet::max_alignment_constraint() {

  return CardTableRS::ct_max_alignment_constraint();

}

class HasAccumulatedModifiedOopsClosure : public KlassClosure {

  bool _found;

 public:

  HasAccumulatedModifiedOopsClosure() : _found(false) {}

  void do_klass(Klass* klass) {

    if (_found) {

      return;

    }

    if (klass->has_accumulated_modified_oops()) {

      _found = true;

    }

  }

  bool found() {

    return _found;

  }

};

bool KlassRemSet::mod_union_is_clear() {

  HasAccumulatedModifiedOopsClosure closure;

  ClassLoaderDataGraph::classes_do(&closure);

  return !closure.found();

}

class ClearKlassModUnionClosure : public KlassClosure {

 public:

  void do_klass(Klass* klass) {

    if (klass->has_accumulated_modified_oops()) {

      klass->clear_accumulated_modified_oops();

    }

  }

};

void KlassRemSet::clear_mod_union() {

  ClearKlassModUnionClosure closure;

  ClassLoaderDataGraph::classes_do(&closure);

}