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 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 virtual bool has_write_ref_pre_barrier() { return true; }
58
59 // This notes that we don't need to access any BarrierSet data
60 // structures, so this can be called from a static context.
61 template <class T> static void write_ref_field_pre_static(T* field, oop newVal) {
62 T heap_oop = oopDesc::load_heap_oop(field);
63 if (!oopDesc::is_null(heap_oop)) {
64 enqueue(oopDesc::decode_heap_oop(heap_oop));
65 }
66 }
67
68 // We export this to make it available in cases where the static
69 // type of the barrier set is known. Note that it is non-virtual.
70 template <class T> inline void inline_write_ref_field_pre(T* field, oop newVal) {
71 write_ref_field_pre_static(field, newVal);
72 }
73
74 // These are the more general virtual versions.
75 virtual void write_ref_field_pre_work(oop* field, oop new_val) {
76 inline_write_ref_field_pre(field, new_val);
77 }
78 virtual void write_ref_field_pre_work(narrowOop* field, oop new_val) {
79 inline_write_ref_field_pre(field, new_val);
80 }
81 virtual void write_ref_field_pre_work(void* field, oop new_val) {
82 guarantee(false, "Not needed");
83 }
84
85 template <class T> void write_ref_array_pre_work(T* dst, int count);
86 virtual void write_ref_array_pre(oop* dst, int count, bool dest_uninitialized);
87 virtual void write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized);
88
89 /*
90 Claimed and deferred bits are used together in G1 during the evacuation
91 pause. These bits can have the following state transitions:
92 1. The claimed bit can be put over any other card state. Except that
93 the "dirty -> dirty and claimed" transition is checked for in
94 G1 code and is not used.
95 2. Deferred bit can be set only if the previous state of the card
96 was either clean or claimed. mark_card_deferred() is wait-free.
97 We do not care if the operation is be successful because if
98 it does not it will only result in duplicate entry in the update
99 buffer because of the "cache-miss". So it's not worth spinning.
100 */
101
102 bool is_card_claimed(size_t card_index) {
103 jbyte val = _byte_map[card_index];
104 return (val & (clean_card_mask_val() | claimed_card_val())) == claimed_card_val();
105 }
106
107 void set_card_claimed(size_t card_index) {
108 jbyte val = _byte_map[card_index];
109 if (val == clean_card_val()) {
110 val = (jbyte)claimed_card_val();
111 } else {
112 val |= (jbyte)claimed_card_val();
113 }
114 _byte_map[card_index] = val;
115 }
116
117 void verify_g1_young_region(MemRegion mr) PRODUCT_RETURN;
118 void g1_mark_as_young(const MemRegion& mr);
119
120 bool mark_card_deferred(size_t card_index);
121
122 bool is_card_deferred(size_t card_index) {
123 jbyte val = _byte_map[card_index];
124 return (val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val();
125 }
126 virtual void write_ref_nmethod_pre(oop* dst, nmethod* nm);
127 virtual void write_ref_nmethod_post(oop* dst, nmethod* nm);
128
129 };
130
131 template<>
132 struct BarrierSet::GetName<G1SATBCardTableModRefBS> {
133 static const BarrierSet::Name value = BarrierSet::G1SATBCT;
134 };
135
136 class G1SATBCardTableLoggingModRefBSChangedListener : public G1MappingChangedListener {
137 private:
138 G1SATBCardTableLoggingModRefBS* _card_table;
139 public:
140 G1SATBCardTableLoggingModRefBSChangedListener() : _card_table(NULL) { }
141
142 void set_card_table(G1SATBCardTableLoggingModRefBS* card_table) { _card_table = card_table; }
143
144 virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled);
145 };
146
147 // Adds card-table logging to the post-barrier.
148 // Usual invariant: all dirty cards are logged in the DirtyCardQueueSet.
149 class G1SATBCardTableLoggingModRefBS: public G1SATBCardTableModRefBS {
150 friend class G1SATBCardTableLoggingModRefBSChangedListener;
151 private:
152 G1SATBCardTableLoggingModRefBSChangedListener _listener;
153 DirtyCardQueueSet& _dcqs;
154
155 protected:
156 virtual void write_ref_field_work(void* field, oop new_val, bool release);
157
158 public:
159 static size_t compute_size(size_t mem_region_size_in_words) {
160 size_t number_of_slots = (mem_region_size_in_words / card_size_in_words);
161 return ReservedSpace::allocation_align_size_up(number_of_slots);
162 }
163
164 // Returns how many bytes of the heap a single byte of the Card Table corresponds to.
165 static size_t heap_map_factor() {
166 return CardTableModRefBS::card_size;
167 }
168
169 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap);
170
171 virtual void initialize() { }
172 virtual void initialize(G1RegionToSpaceMapper* mapper);
173
174 virtual void resize_covered_region(MemRegion new_region) { ShouldNotReachHere(); }
175
176 // Can be called from static contexts.
177 static void write_ref_field_static(void* field, oop new_val);
178
179 // NB: if you do a whole-heap invalidation, the "usual invariant" defined
180 // above no longer applies.
181 void invalidate(MemRegion mr, bool whole_heap = false);
182
183 void write_region_work(MemRegion mr) { invalidate(mr); }
184 void write_ref_array_work(MemRegion mr) { invalidate(mr); }
185 };
186
187 template<>
188 struct BarrierSet::GetName<G1SATBCardTableLoggingModRefBS> {
189 static const BarrierSet::Name value = BarrierSet::G1SATBCTLogging;
190 };
191
192 #endif // SHARE_VM_GC_G1_G1SATBCARDTABLEMODREFBS_HPP