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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  22  *
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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(BarrierSetAssembler* barrier_set_assembler,
  36                    BarrierSetC1* barrier_set_c1,
  37                    BarrierSetC2* barrier_set_c2,
  38                    const BarrierSet::FakeRtti& fake_rtti)
  39     : BarrierSet(barrier_set_assembler,
  40                  barrier_set_c1,
  41                  barrier_set_c2,
  42                  fake_rtti.add_tag(BarrierSet::ModRef)) { }
  43   ~ModRefBarrierSet() { }
  44 
  45 public:
  46   template <DecoratorSet decorators, typename T>
  47   inline void write_ref_field_pre(T* addr) {}
  48 
  49   template <DecoratorSet decorators, typename T>
  50   inline void write_ref_field_post(T *addr, oop new_value) {}
  51 
  52   // Causes all refs in "mr" to be assumed to be modified.
  53   virtual void invalidate(MemRegion mr) = 0;
  54   virtual void write_region(MemRegion mr) = 0;
  55 
  56   // Operations on arrays, or general regions (e.g., for "clone") may be
  57   // optimized by some barriers.
  58 
  59   // Below length is the # array elements being written
  60   virtual void write_ref_array_pre(oop* dst, size_t length,
  61                                    bool dest_uninitialized = false) {}
  62   virtual void write_ref_array_pre(narrowOop* dst, size_t length,
  63                                    bool dest_uninitialized = false) {}
  64   // Below count is the # array elements being written, starting
  65   // at the address "start", which may not necessarily be HeapWord-aligned
  66   inline void write_ref_array(HeapWord* start, size_t count);
  67 
  68  protected:
  69   virtual void write_ref_array_work(MemRegion mr) = 0;
  70 
  71  public:
  72   // The ModRef abstraction introduces pre and post barriers
  73   template <DecoratorSet decorators, typename BarrierSetT>
  74   class AccessBarrier: public BarrierSet::AccessBarrier<decorators, BarrierSetT> {
  75     typedef BarrierSet::AccessBarrier<decorators, BarrierSetT> Raw;
  76 
  77   public:
  78     template <typename T>
  79     static void oop_store_in_heap(T* addr, oop value);
  80     template <typename T>
  81     static oop oop_atomic_cmpxchg_in_heap(oop new_value, T* addr, oop compare_value);
  82     template <typename T>
  83     static oop oop_atomic_xchg_in_heap(oop new_value, T* addr);
  84 
  85     template <typename T>
  86     static bool oop_arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length);
  87 
  88     static void clone_in_heap(oop src, oop dst, size_t size);
  89 
  90     static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
  91       oop_store_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), value);
  92     }
  93 
  94     static oop oop_atomic_xchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset) {
  95       return oop_atomic_xchg_in_heap(new_value, AccessInternal::oop_field_addr<decorators>(base, offset));
  96     }
  97 
  98     static oop oop_atomic_cmpxchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value) {
  99       return oop_atomic_cmpxchg_in_heap(new_value, AccessInternal::oop_field_addr<decorators>(base, offset), compare_value);
 100     }
 101   };
 102 };
 103 
 104 template<>
 105 struct BarrierSet::GetName<ModRefBarrierSet> {
 106   static const BarrierSet::Name value = BarrierSet::ModRef;
 107 };
 108 
 109 #endif // SHARE_VM_GC_SHARED_MODREFBARRIERSET_HPP