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