1 /*
  2  * Copyright (c) 2001, 2021, 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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 24 
 25 #ifndef SHARE_GC_G1_G1BARRIERSET_HPP
 26 #define SHARE_GC_G1_G1BARRIERSET_HPP
 27 
 28 #include "gc/g1/g1DirtyCardQueue.hpp"
 29 #include "gc/g1/g1SATBMarkQueueSet.hpp"
 30 #include "gc/shared/cardTable.hpp"
 31 #include "gc/shared/cardTableBarrierSet.hpp"
 32 
 33 class G1CardTable;
 34 
 35 // This barrier is specialized to use a logging barrier to support
 36 // snapshot-at-the-beginning marking.
 37 
 38 class G1BarrierSet: public CardTableBarrierSet {
 39   friend class VMStructs;
 40  private:
 41   BufferNode::Allocator _satb_mark_queue_buffer_allocator;
 42   BufferNode::Allocator _dirty_card_queue_buffer_allocator;
 43   G1SATBMarkQueueSet _satb_mark_queue_set;
 44   G1DirtyCardQueueSet _dirty_card_queue_set;
 45 
 46   static G1BarrierSet* g1_barrier_set() {
 47     return barrier_set_cast<G1BarrierSet>(BarrierSet::barrier_set());
 48   }
 49 
 50  public:
 51   G1BarrierSet(G1CardTable* table);
 52   ~G1BarrierSet() { }
 53 
 54   virtual bool card_mark_must_follow_store() const {
 55     return true;
 56   }
 57 
 58   // Add "pre_val" to a set of objects that may have been disconnected from the
 59   // pre-marking object graph.
 60   static void enqueue(oop pre_val);
 61 
 62   static void enqueue_if_weak(DecoratorSet decorators, oop value);
 63 
 64   template <class T> void write_ref_array_pre_work(T* dst, size_t count);
 65   virtual void write_ref_array_pre(oop* dst, size_t count, bool dest_uninitialized);
 66   virtual void write_ref_array_pre(narrowOop* dst, size_t count, bool dest_uninitialized);
 67 
 68   template <DecoratorSet decorators, typename T>
 69   void write_ref_field_pre(T* field);
 70 
 71   // NB: if you do a whole-heap invalidation, the "usual invariant" defined
 72   // above no longer applies.
 73   void invalidate(MemRegion mr);
 74 
 75   void write_region(MemRegion mr)         { invalidate(mr); }
 76   void write_ref_array_work(MemRegion mr) { invalidate(mr); }
 77 
 78   template <DecoratorSet decorators, typename T>
 79   void write_ref_field_post(T* field, oop new_val);
 80   void write_ref_field_post_slow(volatile CardValue* byte);
 81 
 82   virtual void on_thread_create(Thread* thread);
 83   virtual void on_thread_destroy(Thread* thread);
 84   virtual void on_thread_attach(Thread* thread);
 85   virtual void on_thread_detach(Thread* thread);
 86 
 87   static G1SATBMarkQueueSet& satb_mark_queue_set() {
 88     return g1_barrier_set()->_satb_mark_queue_set;
 89   }
 90 
 91   static G1DirtyCardQueueSet& dirty_card_queue_set() {
 92     return g1_barrier_set()->_dirty_card_queue_set;
 93   }
 94 
 95   // Callbacks for runtime accesses.
 96   template <DecoratorSet decorators, typename BarrierSetT = G1BarrierSet>
 97   class AccessBarrier: public ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT> {
 98     typedef ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT> ModRef;
 99     typedef BarrierSet::AccessBarrier<decorators, BarrierSetT> Raw;
100 
101   public:
102     // Needed for loads on non-heap weak references
103     template <typename T>
104     static oop oop_load_not_in_heap(T* addr);
105 
106     // Needed for non-heap stores
107     template <typename T>
108     static void oop_store_not_in_heap(T* addr, oop new_value);
109 
110     // Needed for weak references
111     static oop oop_load_in_heap_at(oop base, ptrdiff_t offset);
112 
113     // Defensive: will catch weak oops at addresses in heap
114     template <typename T>
115     static oop oop_load_in_heap(T* addr);
116   };
117 };
118 
119 template<>
120 struct BarrierSet::GetName<G1BarrierSet> {
121   static const BarrierSet::Name value = BarrierSet::G1BarrierSet;
122 };
123 
124 template<>
125 struct BarrierSet::GetType<BarrierSet::G1BarrierSet> {
126   typedef ::G1BarrierSet type;
127 };
128 
129 #endif // SHARE_GC_G1_G1BARRIERSET_HPP