/*
 * 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 HOTSPOT_EPSILONBARRIERSET_HPP_H
#define HOTSPOT_EPSILONBARRIERSET_HPP_H

#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; } // TODO: why?
  virtual bool has_write_region_opt()      { return true; } // TODO: why?

  virtual bool is_aligned(HeapWord *addr)  { return true; } // TODO: Safe?

  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