1 /*
  2  * Copyright (c) 2001, 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
 21  * questions.
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 23  */
 24 
 25 #ifndef SHARE_VM_GC_G1_G1BARRIERSET_HPP
 26 #define SHARE_VM_GC_G1_G1BARRIERSET_HPP
 27 
 28 #include "gc/shared/cardTableModRefBS.hpp"
 29 
 30 class DirtyCardQueueSet;
 31 class CardTable;
 32 class G1CardTable;
 33 
 34 // This barrier is specialized to use a logging barrier to support
 35 // snapshot-at-the-beginning marking.
 36 
 37 class G1BarrierSet: public CardTableModRefBS {
 38   friend class VMStructs;
 39  private:
 40   DirtyCardQueueSet& _dcqs;
 41 
 42  public:
 43   G1BarrierSet(G1CardTable* table);
 44   ~G1BarrierSet() { }
 45 
 46   // Add "pre_val" to a set of objects that may have been disconnected from the
 47   // pre-marking object graph.
 48   static void enqueue(oop pre_val);
 49 
 50   static void enqueue_if_weak_or_archive(DecoratorSet decorators, oop value);
 51 
 52   template <class T> void write_ref_array_pre_work(T* dst, int count);
 53   virtual void write_ref_array_pre(oop* dst, int count, bool dest_uninitialized);
 54   virtual void write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized);
 55 
 56   static void write_ref_array_pre_oop_entry(oop* dst, size_t length);
 57   static void write_ref_array_pre_narrow_oop_entry(narrowOop* dst, size_t length);
 58   static void write_ref_array_post_entry(HeapWord* dst, size_t length);
 59 
 60   template <DecoratorSet decorators, typename T>
 61   void write_ref_field_pre(T* field);
 62 
 63   // NB: if you do a whole-heap invalidation, the "usual invariant" defined
 64   // above no longer applies.
 65   void invalidate(MemRegion mr);
 66 
 67   void write_region(MemRegion mr)         { invalidate(mr); }
 68   void write_ref_array_work(MemRegion mr) { invalidate(mr); }
 69 
 70   template <DecoratorSet decorators, typename T>
 71   void write_ref_field_post(T* field, oop new_val);
 72   void write_ref_field_post_slow(volatile jbyte* byte);
 73 
 74   virtual void on_thread_attach(JavaThread* thread);
 75   virtual void on_thread_detach(JavaThread* thread);
 76 
 77 protected:
 78   virtual BarrierSetCodeGen *make_code_gen();
 79 
 80 public:
 81   // Callbacks for runtime accesses.
 82   template <DecoratorSet decorators, typename BarrierSetT = G1BarrierSet>
 83   class AccessBarrier: public ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT> {
 84     typedef ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT> ModRef;
 85     typedef BarrierSet::AccessBarrier<decorators, BarrierSetT> Raw;
 86 
 87   public:
 88     // Needed for loads on non-heap weak references
 89     template <typename T>
 90     static oop oop_load_not_in_heap(T* addr);
 91 
 92     // Needed for non-heap stores
 93     template <typename T>
 94     static void oop_store_not_in_heap(T* addr, oop new_value);
 95 
 96     // Needed for weak references
 97     static oop oop_load_in_heap_at(oop base, ptrdiff_t offset);
 98 
 99     // Defensive: will catch weak oops at addresses in heap
100     template <typename T>
101     static oop oop_load_in_heap(T* addr);
102   };
103 };
104 
105 template<>
106 struct BarrierSet::GetName<G1BarrierSet> {
107   static const BarrierSet::Name value = BarrierSet::G1BarrierSet;
108 };
109 
110 template<>
111 struct BarrierSet::GetType<BarrierSet::G1BarrierSet> {
112   typedef ::G1BarrierSet type;
113 };
114 
115 #endif // SHARE_VM_GC_G1_G1BARRIERSET_HPP