/*

 * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates.

 *

 * 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_EPSILON_BARRIERSET_HPP

#define SHARE_VM_GC_EPSILON_BARRIERSET_HPP

#include "gc/shared/collectorPolicy.hpp"

#include "gc/shared/barrierSet.hpp"

// Most are no-ops.

class EpsilonBarrierSet: public ModRefBarrierSet {

  friend class VMStructs;

public:

  EpsilonBarrierSet() :

          ModRefBarrierSet(BarrierSet::FakeRtti(BarrierSet::Epsilon)) {};

  virtual bool has_write_ref_barrier()     { return false; }

  virtual bool has_write_ref_pre_barrier() { return false; }

  virtual bool has_write_ref_array_opt()   { return true;  } // claim we have these, and then do noop

  virtual bool has_write_region_opt()      { return true;  } // claim we have these, and then do noop

  virtual bool is_aligned(HeapWord *addr)  { Unimplemented(); return true; } // no calls for it?

  virtual void resize_covered_region(MemRegion new_region) {}

  virtual void print_on(outputStream *st) const {}

protected:

  virtual void write_ref_field_work(void *field, oop new_val, bool release) {}

  virtual void write_ref_array_work(MemRegion mr) {}

  virtual void write_region_work(MemRegion mr) {}

public:

  virtual void invalidate(MemRegion mr) {}

  virtual void clear(MemRegion mr) {}

};

template<>

struct BarrierSet::GetName<EpsilonBarrierSet> {

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

};

#endif // SHARE_VM_GC_EPSILON_BARRIERSET_HPP