1 /*
   2  * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 #ifndef SHARE_VM_GC_EPSILON_BARRIERSET_HPP
  25 #define SHARE_VM_GC_EPSILON_BARRIERSET_HPP
  26 
  27 #include "gc/shared/barrierSetAssembler.hpp"
  28 #include "gc/shared/barrierSet.hpp"
  29 
  30 // No interaction with application is required for Epsilon, and therefore
  31 // the barrier set is empty.
  32 class EpsilonBarrierSet: public BarrierSet {
  33   friend class VMStructs;
  34 
  35 public:
  36   EpsilonBarrierSet();
  37 
  38   virtual void print_on(outputStream *st) const {}
  39 
  40   virtual void on_thread_create(Thread* thread);
  41   virtual void on_thread_destroy(Thread* thread);
  42 
  43   template <DecoratorSet decorators, typename BarrierSetT = EpsilonBarrierSet>
  44   class AccessBarrier: public BarrierSet::AccessBarrier<decorators, BarrierSetT> {};
  45 };
  46 
  47 template<>
  48 struct BarrierSet::GetName<EpsilonBarrierSet> {
  49   static const BarrierSet::Name value = BarrierSet::EpsilonBarrierSet;
  50 };
  51 
  52 template<>
  53 struct BarrierSet::GetType<BarrierSet::EpsilonBarrierSet> {
  54   typedef ::EpsilonBarrierSet type;
  55 };
  56 
  57 #endif // SHARE_VM_GC_EPSILON_BARRIERSET_HPP