1 /*
2 * Copyright (c) 2001, 2015, 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 protected:
42 enum G1CardValues {
43 g1_young_gen = CT_MR_BS_last_reserved << 1
44 };
45
46 G1SATBCardTableModRefBS(MemRegion whole_heap, const BarrierSet::FakeRtti& fake_rtti);
47 ~G1SATBCardTableModRefBS() { }
48
49 public:
50 static int g1_young_card_val() { return g1_young_gen; }
51
52 // Add "pre_val" to a set of objects that may have been disconnected from the
53 // pre-marking object graph.
54 static void enqueue(oop pre_val);
55
56 virtual bool has_write_ref_pre_barrier() { return true; }
57
58 // This notes that we don't need to access any BarrierSet data
59 // structures, so this can be called from a static context.
60 template <class T> static void write_ref_field_pre_static(T* field, oop newVal) {
61 T heap_oop = oopDesc::load_heap_oop(field);
62 if (!oopDesc::is_null(heap_oop)) {
63 enqueue(oopDesc::decode_heap_oop(heap_oop));
64 }
65 }
66
67 // We export this to make it available in cases where the static
68 // type of the barrier set is known. Note that it is non-virtual.
69 template <class T> inline void inline_write_ref_field_pre(T* field, oop newVal) {
70 write_ref_field_pre_static(field, newVal);
71 }
72
73 // These are the more general virtual versions.
74 virtual void write_ref_field_pre_work(oop* field, oop new_val) {
75 inline_write_ref_field_pre(field, new_val);
76 }
77 virtual void write_ref_field_pre_work(narrowOop* field, oop new_val) {
78 inline_write_ref_field_pre(field, new_val);
79 }
80 virtual void write_ref_field_pre_work(void* field, oop new_val) {
81 guarantee(false, "Not needed");
82 }
83
84 template <class T> void write_ref_array_pre_work(T* dst, int count);
85 virtual void write_ref_array_pre(oop* dst, int count, bool dest_uninitialized);
86 virtual void write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized);
87
88 /*
89 Claimed and deferred bits are used together in G1 during the evacuation
90 pause. These bits can have the following state transitions:
91 1. The claimed bit can be put over any other card state. Except that
92 the "dirty -> dirty and claimed" transition is checked for in
93 G1 code and is not used.
94 2. Deferred bit can be set only if the previous state of the card
95 was either clean or claimed. mark_card_deferred() is wait-free.
96 We do not care if the operation is be successful because if
97 it does not it will only result in duplicate entry in the update
98 buffer because of the "cache-miss". So it's not worth spinning.
99 */
100
101 bool is_card_claimed(size_t card_index) {
102 jbyte val = _byte_map[card_index];
103 return (val & (clean_card_mask_val() | claimed_card_val())) == claimed_card_val();
104 }
105
106 void set_card_claimed(size_t card_index) {
107 jbyte val = _byte_map[card_index];
108 if (val == clean_card_val()) {
109 val = (jbyte)claimed_card_val();
110 } else {
111 val |= (jbyte)claimed_card_val();
112 }
113 _byte_map[card_index] = val;
114 }
115
116 void verify_g1_young_region(MemRegion mr) PRODUCT_RETURN;
117 void g1_mark_as_young(const MemRegion& mr);
118
119 bool mark_card_deferred(size_t card_index);
120
121 bool is_card_deferred(size_t card_index) {
122 jbyte val = _byte_map[card_index];
123 return (val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val();
124 }
125 };
126
127 template<>
128 struct BarrierSet::GetName<G1SATBCardTableModRefBS> {
129 static const BarrierSet::Name value = BarrierSet::G1SATBCT;
130 };
131
132 class G1SATBCardTableLoggingModRefBSChangedListener : public G1MappingChangedListener {
133 private:
134 G1SATBCardTableLoggingModRefBS* _card_table;
135 public:
136 G1SATBCardTableLoggingModRefBSChangedListener() : _card_table(NULL) { }
137
138 void set_card_table(G1SATBCardTableLoggingModRefBS* card_table) { _card_table = card_table; }
139
140 virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled);
141 };
142
143 // Adds card-table logging to the post-barrier.
144 // Usual invariant: all dirty cards are logged in the DirtyCardQueueSet.
145 class G1SATBCardTableLoggingModRefBS: public G1SATBCardTableModRefBS {
146 friend class G1SATBCardTableLoggingModRefBSChangedListener;
147 private:
148 G1SATBCardTableLoggingModRefBSChangedListener _listener;
149 DirtyCardQueueSet& _dcqs;
150 public:
151 static size_t compute_size(size_t mem_region_size_in_words) {
152 size_t number_of_slots = (mem_region_size_in_words / card_size_in_words);
153 return ReservedSpace::allocation_align_size_up(number_of_slots);
154 }
155
156 // Returns how many bytes of the heap a single byte of the Card Table corresponds to.
157 static size_t heap_map_factor() {
158 return CardTableModRefBS::card_size;
159 }
160
161 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap);
162
163 virtual void initialize() { }
164 virtual void initialize(G1RegionToSpaceMapper* mapper);
165
166 virtual void resize_covered_region(MemRegion new_region) { ShouldNotReachHere(); }
167
168 void write_ref_field_work(void* field, oop new_val, bool release = false);
169
170 // Can be called from static contexts.
171 static void write_ref_field_static(void* field, oop new_val);
172
173 // NB: if you do a whole-heap invalidation, the "usual invariant" defined
174 // above no longer applies.
175 void invalidate(MemRegion mr, bool whole_heap = false);
176
177 void write_region_work(MemRegion mr) { invalidate(mr); }
178 void write_ref_array_work(MemRegion mr) { invalidate(mr); }
179 };
180
181 template<>
182 struct BarrierSet::GetName<G1SATBCardTableLoggingModRefBS> {
183 static const BarrierSet::Name value = BarrierSet::G1SATBCTLogging;
184 };
185
186 #endif // SHARE_VM_GC_G1_G1SATBCARDTABLEMODREFBS_HPP