1 /*
2 * Copyright (c) 2001, 2013, 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 #if INCLUDE_ALL_GCS
35
36 class DirtyCardQueueSet;
37 class G1SATBCardTableLoggingModRefBS;
38
39 // This barrier is specialized to use a logging barrier to support
40 // snapshot-at-the-beginning marking.
41
42 class G1SATBCardTableModRefBS: public CardTableModRefBSForCTRS {
43 protected:
44 enum G1CardValues {
45 g1_young_gen = CT_MR_BS_last_reserved << 1
46 };
47
48 public:
49 static int g1_young_card_val() { return g1_young_gen; }
50
51 // Add "pre_val" to a set of objects that may have been disconnected from the
52 // pre-marking object graph.
53 static void enqueue(oop pre_val);
54
55 G1SATBCardTableModRefBS(MemRegion whole_heap,
56 int max_covered_regions);
57
58 bool is_a(BarrierSet::Name bsn) {
59 return bsn == BarrierSet::G1SATBCT || CardTableModRefBS::is_a(bsn);
60 }
61
62 virtual bool has_write_ref_pre_barrier() { return true; }
63
64 // This notes that we don't need to access any BarrierSet data
65 // structures, so this can be called from a static context.
66 template <class T> static void write_ref_field_pre_static(T* field, oop newVal) {
67 T heap_oop = oopDesc::load_heap_oop(field);
68 if (!oopDesc::is_null(heap_oop)) {
69 enqueue(oopDesc::decode_heap_oop(heap_oop));
70 }
71 }
72
73 // We export this to make it available in cases where the static
74 // type of the barrier set is known. Note that it is non-virtual.
75 template <class T> inline void inline_write_ref_field_pre(T* field, oop newVal) {
76 write_ref_field_pre_static(field, newVal);
77 }
78
79 // These are the more general virtual versions.
80 virtual void write_ref_field_pre_work(oop* field, oop new_val) {
81 inline_write_ref_field_pre(field, new_val);
82 }
83 virtual void write_ref_field_pre_work(narrowOop* field, oop new_val) {
84 inline_write_ref_field_pre(field, new_val);
85 }
86 virtual void write_ref_field_pre_work(void* field, oop new_val) {
87 guarantee(false, "Not needed");
88 }
89
90 template <class T> void write_ref_array_pre_work(T* dst, int count);
91 virtual void write_ref_array_pre(oop* dst, int count, bool dest_uninitialized);
92 virtual void write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized);
93
94 /*
95 Claimed and deferred bits are used together in G1 during the evacuation
96 pause. These bits can have the following state transitions:
97 1. The claimed bit can be put over any other card state. Except that
98 the "dirty -> dirty and claimed" transition is checked for in
99 G1 code and is not used.
100 2. Deferred bit can be set only if the previous state of the card
101 was either clean or claimed. mark_card_deferred() is wait-free.
102 We do not care if the operation is be successful because if
103 it does not it will only result in duplicate entry in the update
104 buffer because of the "cache-miss". So it's not worth spinning.
105 */
106
107 bool is_card_claimed(size_t card_index) {
108 jbyte val = _byte_map[card_index];
109 return (val & (clean_card_mask_val() | claimed_card_val())) == claimed_card_val();
110 }
111
112 void set_card_claimed(size_t card_index) {
113 jbyte val = _byte_map[card_index];
114 if (val == clean_card_val()) {
115 val = (jbyte)claimed_card_val();
116 } else {
117 val |= (jbyte)claimed_card_val();
118 }
119 _byte_map[card_index] = val;
120 }
121
122 void verify_g1_young_region(MemRegion mr) PRODUCT_RETURN;
123 void g1_mark_as_young(const MemRegion& mr);
124
125 bool mark_card_deferred(size_t card_index);
126
127 bool is_card_deferred(size_t card_index) {
128 jbyte val = _byte_map[card_index];
129 return (val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val();
130 }
131 };
132
133 class G1SATBCardTableLoggingModRefBSChangedListener : public G1MappingChangedListener {
134 private:
135 G1SATBCardTableLoggingModRefBS* _card_table;
136 public:
137 G1SATBCardTableLoggingModRefBSChangedListener() : _card_table(NULL) { }
138
139 void set_card_table(G1SATBCardTableLoggingModRefBS* card_table) { _card_table = card_table; }
140
141 virtual void on_commit(uint start_idx, size_t num_regions);
142 };
143
144 // Adds card-table logging to the post-barrier.
145 // Usual invariant: all dirty cards are logged in the DirtyCardQueueSet.
146 class G1SATBCardTableLoggingModRefBS: public G1SATBCardTableModRefBS {
147 friend class G1SATBCardTableLoggingModRefBSChangedListener;
148 private:
149 G1SATBCardTableLoggingModRefBSChangedListener _listener;
150 DirtyCardQueueSet& _dcqs;
151 public:
152 static size_t compute_size(size_t mem_region_size_in_words) {
153 size_t number_of_slots = (mem_region_size_in_words / card_size_in_words);
154 return ReservedSpace::allocation_align_size_up(number_of_slots);
155 }
156
157 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
158 int max_covered_regions);
159
160 virtual void initialize() { }
161 virtual void initialize(G1RegionToSpaceMapper* mapper);
162
163 virtual void resize_covered_region(MemRegion new_region) { ShouldNotReachHere(); }
164
165 bool is_a(BarrierSet::Name bsn) {
166 return bsn == BarrierSet::G1SATBCTLogging ||
167 G1SATBCardTableModRefBS::is_a(bsn);
168 }
169
170 void write_ref_field_work(void* field, oop new_val, bool release = false);
171
172 // Can be called from static contexts.
173 static void write_ref_field_static(void* field, oop new_val);
174
175 // NB: if you do a whole-heap invalidation, the "usual invariant" defined
176 // above no longer applies.
177 void invalidate(MemRegion mr, bool whole_heap = false);
178
179 void write_region_work(MemRegion mr) { invalidate(mr); }
180 void write_ref_array_work(MemRegion mr) { invalidate(mr); }
181 };
182
183
184 #endif // INCLUDE_ALL_GCS
185
186 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1SATBCARDTABLEMODREFBS_HPP