1 /*
2 * Copyright (c) 2001, 2017, 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_G1SATBCARDTABLEMODREFBS_HPP
26 #define SHARE_VM_GC_G1_G1SATBCARDTABLEMODREFBS_HPP
27
28 #include "gc/g1/g1RegionToSpaceMapper.hpp"
29 #include "gc/shared/cardTableModRefBS.hpp"
30 #include "memory/memRegion.hpp"
31 #include "oops/oop.hpp"
32 #include "utilities/macros.hpp"
33
34 class DirtyCardQueueSet;
35 class G1SATBCardTableLoggingModRefBS;
36
37 // This barrier is specialized to use a logging barrier to support
38 // snapshot-at-the-beginning marking.
39
40 class G1SATBCardTableModRefBS: public CardTableModRefBS {
41 friend class VMStructs;
42 protected:
43 enum G1CardValues {
44 g1_young_gen = CT_MR_BS_last_reserved << 1
45 };
46
47 G1SATBCardTableModRefBS(MemRegion whole_heap, const BarrierSet::FakeRtti& fake_rtti);
48 ~G1SATBCardTableModRefBS() { }
49
50 public:
51 static int g1_young_card_val() { return g1_young_gen; }
52
53 // Add "pre_val" to a set of objects that may have been disconnected from the
54 // pre-marking object graph.
55 static void enqueue(oop pre_val);
56
57 // We export this to make it available in cases where the static
58 // type of the barrier set is known. Note that it is non-virtual.
59 template <class T> inline void inline_write_ref_field_pre(T* field, oop newVal);
60
61 // These are the more general virtual versions.
62 inline virtual void write_ref_field_pre_work(oop* field, oop new_val);
63 inline virtual void write_ref_field_pre_work(narrowOop* field, oop new_val);
64
65 template <class T> void write_ref_array_pre_work(T* dst, int count);
66 virtual void write_ref_array_pre(oop* dst, int count, bool dest_uninitialized);
67 virtual void write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized);
68
69 /*
70 Claimed and deferred bits are used together in G1 during the evacuation
71 pause. These bits can have the following state transitions:
72 1. The claimed bit can be put over any other card state. Except that
73 the "dirty -> dirty and claimed" transition is checked for in
74 G1 code and is not used.
75 2. Deferred bit can be set only if the previous state of the card
76 was either clean or claimed. mark_card_deferred() is wait-free.
77 We do not care if the operation is be successful because if
78 it does not it will only result in duplicate entry in the update
79 buffer because of the "cache-miss". So it's not worth spinning.
80 */
81
82 bool is_card_claimed(size_t card_index) {
83 jbyte val = _byte_map[card_index];
84 return (val & (clean_card_mask_val() | claimed_card_val())) == claimed_card_val();
85 }
86
87 inline void set_card_claimed(size_t card_index);
88
89 void verify_g1_young_region(MemRegion mr) PRODUCT_RETURN;
90 void g1_mark_as_young(const MemRegion& mr);
91
92 bool mark_card_deferred(size_t card_index);
93
94 bool is_card_deferred(size_t card_index) {
95 jbyte val = _byte_map[card_index];
96 return (val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val();
97 }
98 virtual void write_ref_nmethod_pre(oop* dst, nmethod* nm);
99 virtual void write_ref_nmethod_post(oop* dst, nmethod* nm);
100
101 };
102
103 template<>
104 struct BarrierSet::GetName<G1SATBCardTableModRefBS> {
105 static const BarrierSet::Name value = BarrierSet::G1SATBCT;
106 };
107
108 class G1SATBCardTableLoggingModRefBSChangedListener : public G1MappingChangedListener {
109 private:
110 G1SATBCardTableLoggingModRefBS* _card_table;
111 public:
112 G1SATBCardTableLoggingModRefBSChangedListener() : _card_table(NULL) { }
113
114 void set_card_table(G1SATBCardTableLoggingModRefBS* card_table) { _card_table = card_table; }
115
116 virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled);
117 };
118
119 // Adds card-table logging to the post-barrier.
120 // Usual invariant: all dirty cards are logged in the DirtyCardQueueSet.
121 class G1SATBCardTableLoggingModRefBS: public G1SATBCardTableModRefBS {
122 friend class G1SATBCardTableLoggingModRefBSChangedListener;
123 private:
124 G1SATBCardTableLoggingModRefBSChangedListener _listener;
125 DirtyCardQueueSet& _dcqs;
126
127 protected:
128 virtual void write_ref_field_work(void* field, oop new_val, bool release);
129
130 public:
131 static size_t compute_size(size_t mem_region_size_in_words) {
132 size_t number_of_slots = (mem_region_size_in_words / card_size_in_words);
133 return ReservedSpace::allocation_align_size_up(number_of_slots);
134 }
135
136 // Returns how many bytes of the heap a single byte of the Card Table corresponds to.
137 static size_t heap_map_factor() {
138 return CardTableModRefBS::card_size;
139 }
140
141 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap);
142
143 virtual void initialize() { }
144 virtual void initialize(G1RegionToSpaceMapper* mapper);
145
146 virtual void resize_covered_region(MemRegion new_region) { ShouldNotReachHere(); }
147
148 // NB: if you do a whole-heap invalidation, the "usual invariant" defined
149 // above no longer applies.
150 void invalidate(MemRegion mr);
151
152 void write_region_work(MemRegion mr) { invalidate(mr); }
153 void write_ref_array_work(MemRegion mr) { invalidate(mr); }
154 };
155
156 template<>
157 struct BarrierSet::GetName<G1SATBCardTableLoggingModRefBS> {
158 static const BarrierSet::Name value = BarrierSet::G1SATBCTLogging;
159 };
160
161 #endif // SHARE_VM_GC_G1_G1SATBCARDTABLEMODREFBS_HPP