1 /*
  2  * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
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 24 
 25 #ifndef SHARE_VM_GC_SHARED_MODREFBARRIERSET_HPP
 26 #define SHARE_VM_GC_SHARED_MODREFBARRIERSET_HPP
 27 
 28 #include "gc/shared/barrierSet.hpp"
 29 #include "memory/memRegion.hpp"
 30 
 31 class Klass;
 32 
 33 class ModRefBarrierSet: public BarrierSet {
 34 protected:
 35   ModRefBarrierSet(const BarrierSet::FakeRtti& fake_rtti)
 36     : BarrierSet(fake_rtti.add_tag(BarrierSet::ModRef)) { }
 37   ~ModRefBarrierSet() { }
 38 
 39 public:
 40   template <DecoratorSet decorators, typename T>
 41   inline void write_ref_field_pre(T* addr) {}
 42 
 43   template <DecoratorSet decorators, typename T>
 44   inline void write_ref_field_post(T *addr, oop new_value) {}
 45 
 46   // Causes all refs in "mr" to be assumed to be modified.
 47   virtual void invalidate(MemRegion mr) = 0;
 48   virtual void write_region(MemRegion mr) = 0;
 49 
 50   // Operations on arrays, or general regions (e.g., for "clone") may be
 51   // optimized by some barriers.
 52 
 53   // Below length is the # array elements being written
 54   virtual void write_ref_array_pre(oop* dst, int length,
 55                                    bool dest_uninitialized = false) {}
 56   virtual void write_ref_array_pre(narrowOop* dst, int length,
 57                                    bool dest_uninitialized = false) {}
 58   // Below count is the # array elements being written, starting
 59   // at the address "start", which may not necessarily be HeapWord-aligned
 60   inline void write_ref_array(HeapWord* start, size_t count);
 61 
 62  protected:
 63   virtual void write_ref_array_work(MemRegion mr) = 0;
 64 
 65  public:
 66   // The ModRef abstraction introduces pre and post barriers
 67   template <DecoratorSet decorators, typename BarrierSetT>
 68   class AccessBarrier: public BarrierSet::AccessBarrier<decorators, BarrierSetT> {
 69     typedef BarrierSet::AccessBarrier<decorators, BarrierSetT> Raw;
 70 
 71   public:
 72     template <typename T>
 73     static void oop_store_in_heap(T* addr, oop value);
 74     template <typename T>
 75     static oop oop_atomic_cmpxchg_in_heap(oop new_value, T* addr, oop compare_value);
 76     template <typename T>
 77     static oop oop_atomic_xchg_in_heap(oop new_value, T* addr);
 78 
 79     template <typename T>
 80     static bool oop_arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length);
 81 
 82     static void clone_in_heap(oop src, oop dst, size_t size);
 83 
 84     static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
 85       oop_store_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), value);
 86     }
 87 
 88     static oop oop_atomic_xchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset) {
 89       return oop_atomic_xchg_in_heap(new_value, AccessInternal::oop_field_addr<decorators>(base, offset));
 90     }
 91 
 92     static oop oop_atomic_cmpxchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value) {
 93       return oop_atomic_cmpxchg_in_heap(new_value, AccessInternal::oop_field_addr<decorators>(base, offset), compare_value);
 94     }
 95   };
 96 };
 97 
 98 template<>
 99 struct BarrierSet::GetName<ModRefBarrierSet> {
100   static const BarrierSet::Name value = BarrierSet::ModRef;
101 };
102 
103 #endif // SHARE_VM_GC_SHARED_MODREFBARRIERSET_HPP