1 /*
2 * Copyright (c) 2001, 2014, 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.
22 *
23 */
24
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1SATBCARDTABLEMODREFBS_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1SATBCARDTABLEMODREFBS_HPP
27
28 #include "gc_implementation/g1/g1RegionToSpaceMapper.hpp"
29 #include "memory/cardTableModRefBS.hpp"
30 #include "memory/memRegion.hpp"
31 #include "oops/oop.inline.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 public:
47 static int g1_young_card_val() { return g1_young_gen; }
48
49 // Add "pre_val" to a set of objects that may have been disconnected from the
50 // pre-marking object graph.
51 static void enqueue(oop pre_val);
52
53 G1SATBCardTableModRefBS(MemRegion whole_heap);
54
55 bool is_a(BarrierSet::Name bsn) {
56 return bsn == BarrierSet::G1SATBCT || CardTableModRefBS::is_a(bsn);
57 }
58
59 virtual bool has_write_ref_pre_barrier() { return true; }
60
61 // This notes that we don't need to access any BarrierSet data
62 // structures, so this can be called from a static context.
63 template <class T> static void write_ref_field_pre_static(T* field, oop newVal) {
64 T heap_oop = oopDesc::load_heap_oop(field);
65 if (!oopDesc::is_null(heap_oop)) {
66 enqueue(oopDesc::decode_heap_oop(heap_oop));
67 }
68 }
69
70 // We export this to make it available in cases where the static
71 // type of the barrier set is known. Note that it is non-virtual.
72 template <class T> inline void inline_write_ref_field_pre(T* field, oop newVal) {
73 write_ref_field_pre_static(field, newVal);
74 }
75
76 // These are the more general virtual versions.
77 virtual void write_ref_field_pre_work(oop* field, oop new_val) {
78 inline_write_ref_field_pre(field, new_val);
79 }
80 virtual void write_ref_field_pre_work(narrowOop* field, oop new_val) {
81 inline_write_ref_field_pre(field, new_val);
82 }
83 virtual void write_ref_field_pre_work(void* field, oop new_val) {
84 guarantee(false, "Not needed");
85 }
86
87 template <class T> void write_ref_array_pre_work(T* dst, int count);
88 virtual void write_ref_array_pre(oop* dst, int count, bool dest_uninitialized);
89 virtual void write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized);
90
91 /*
92 Claimed and deferred bits are used together in G1 during the evacuation
93 pause. These bits can have the following state transitions:
94 1. The claimed bit can be put over any other card state. Except that
95 the "dirty -> dirty and claimed" transition is checked for in
96 G1 code and is not used.
97 2. Deferred bit can be set only if the previous state of the card
98 was either clean or claimed. mark_card_deferred() is wait-free.
99 We do not care if the operation is be successful because if
100 it does not it will only result in duplicate entry in the update
101 buffer because of the "cache-miss". So it's not worth spinning.
102 */
103
104 bool is_card_claimed(size_t card_index) {
105 jbyte val = _byte_map[card_index];
106 return (val & (clean_card_mask_val() | claimed_card_val())) == claimed_card_val();
107 }
108
109 void set_card_claimed(size_t card_index) {
110 jbyte val = _byte_map[card_index];
111 if (val == clean_card_val()) {
112 val = (jbyte)claimed_card_val();
113 } else {
114 val |= (jbyte)claimed_card_val();
115 }
116 _byte_map[card_index] = val;
117 }
118
119 void verify_g1_young_region(MemRegion mr) PRODUCT_RETURN;
120 void g1_mark_as_young(const MemRegion& mr);
121
122 bool mark_card_deferred(size_t card_index);
123
124 bool is_card_deferred(size_t card_index) {
125 jbyte val = _byte_map[card_index];
126 return (val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val();
127 }
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 public:
149 static size_t compute_size(size_t mem_region_size_in_words) {
150 size_t number_of_slots = (mem_region_size_in_words / card_size_in_words);
151 return ReservedSpace::allocation_align_size_up(number_of_slots);
152 }
153
154 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap);
155
156 virtual void initialize() { }
157 virtual void initialize(G1RegionToSpaceMapper* mapper);
158
159 virtual void resize_covered_region(MemRegion new_region) { ShouldNotReachHere(); }
160
161 bool is_a(BarrierSet::Name bsn) {
162 return bsn == BarrierSet::G1SATBCTLogging ||
163 G1SATBCardTableModRefBS::is_a(bsn);
164 }
165
166 void write_ref_field_work(void* field, oop new_val, bool release = false);
167
168 // Can be called from static contexts.
169 static void write_ref_field_static(void* field, oop new_val);
170
171 // NB: if you do a whole-heap invalidation, the "usual invariant" defined
172 // above no longer applies.
173 void invalidate(MemRegion mr, bool whole_heap = false);
174
175 void write_region_work(MemRegion mr) { invalidate(mr); }
176 void write_ref_array_work(MemRegion mr) { invalidate(mr); }
177 };
178
179 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1SATBCARDTABLEMODREFBS_HPP