/*

 * 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.

 *

 */

#ifndef SHARE_VM_GC_SHARED_MODREFBARRIERSET_HPP

#define SHARE_VM_GC_SHARED_MODREFBARRIERSET_HPP

#include "gc/shared/barrierSet.hpp"

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

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

// enumeration), using a card table.

class OopClosure;

class Generation;

class ModRefBarrierSet: public BarrierSet {

protected:

  ModRefBarrierSet(const BarrierSet::FakeRtti& fake_rtti)

    : BarrierSet(fake_rtti.add_tag(BarrierSet::ModRef)) { }

  ~ModRefBarrierSet() { }

public:

  // Causes all refs in "mr" to be assumed to be modified.

  virtual void invalidate(MemRegion mr) = 0;

  // The caller guarantees that "mr" contains no references.  (Perhaps it's

  // objects have been moved elsewhere.)

  virtual void clear(MemRegion mr) = 0;

};

template<>

struct BarrierSet::GetName<ModRefBarrierSet> {

  static const BarrierSet::Name value = BarrierSet::ModRef;

};

#endif // SHARE_VM_GC_SHARED_MODREFBARRIERSET_HPP