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 #include "precompiled.hpp"
26 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
27 #include "gc_implementation/g1/heapRegion.hpp"
28 #include "gc_implementation/g1/satbQueue.hpp"
29 #include "runtime/mutexLocker.hpp"
30 #include "runtime/orderAccess.inline.hpp"
31 #include "runtime/thread.inline.hpp"
32
33 G1SATBCardTableModRefBS::G1SATBCardTableModRefBS(MemRegion whole_heap,
34 int max_covered_regions) :
35 CardTableModRefBSForCTRS(whole_heap, max_covered_regions)
36 {
37 _kind = G1SATBCT;
38 }
39
40
41 void G1SATBCardTableModRefBS::enqueue(oop pre_val) {
42 // Nulls should have been already filtered.
43 assert(pre_val->is_oop(true), "Error");
44
45 if (!JavaThread::satb_mark_queue_set().is_active()) return;
46 Thread* thr = Thread::current();
47 if (thr->is_Java_thread()) {
48 JavaThread* jt = (JavaThread*)thr;
49 jt->satb_mark_queue().enqueue(pre_val);
50 } else {
51 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag);
52 JavaThread::satb_mark_queue_set().shared_satb_queue()->enqueue(pre_val);
53 }
54 }
55
56 template <class T> void
57 G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) {
58 if (!JavaThread::satb_mark_queue_set().is_active()) return;
59 T* elem_ptr = dst;
60 for (int i = 0; i < count; i++, elem_ptr++) {
61 T heap_oop = oopDesc::load_heap_oop(elem_ptr);
62 if (!oopDesc::is_null(heap_oop)) {
63 enqueue(oopDesc::decode_heap_oop_not_null(heap_oop));
64 }
65 }
66 }
67
68 bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {
69 jbyte val = _byte_map[card_index];
70 // It's already processed
71 if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
72 return false;
73 }
74
75 if (val == g1_young_gen) {
76 // the card is for a young gen region. We don't need to keep track of all pointers into young
77 return false;
78 }
79
80 // Cached bit can be installed either on a clean card or on a claimed card.
81 jbyte new_val = val;
82 if (val == clean_card_val()) {
83 new_val = (jbyte)deferred_card_val();
84 } else {
85 if (val & claimed_card_val()) {
86 new_val = val | (jbyte)deferred_card_val();
87 }
88 }
89 if (new_val != val) {
90 Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
91 }
92 return true;
93 }
94
95 void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) {
96 jbyte *const first = byte_for(mr.start());
97 jbyte *const last = byte_after(mr.last());
98
99 // Below we may use an explicit loop instead of memset() because on
100 // certain platforms memset() can give concurrent readers phantom zeros.
101 if (UseMemSetInBOT) {
102 memset(first, g1_young_gen, last - first);
103 } else {
104 for (jbyte* i = first; i < last; i++) {
105 *i = g1_young_gen;
106 }
107 }
108 }
109
110 #ifndef PRODUCT
111 void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) {
112 verify_region(mr, g1_young_gen, true);
113 }
114 #endif
115
116 G1SATBCardTableLoggingModRefBS::
117 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
118 int max_covered_regions) :
119 G1SATBCardTableModRefBS(whole_heap, max_covered_regions),
120 _dcqs(JavaThread::dirty_card_queue_set())
121 {
122 _kind = G1SATBCTLogging;
123 }
124
125 void
126 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
127 oop new_val,
128 bool release) {
129 volatile jbyte* byte = byte_for(field);
130 if (*byte == g1_young_gen) {
131 return;
132 }
133 OrderAccess::storeload();
134 if (*byte != dirty_card) {
135 *byte = dirty_card;
136 Thread* thr = Thread::current();
137 if (thr->is_Java_thread()) {
138 JavaThread* jt = (JavaThread*)thr;
139 jt->dirty_card_queue().enqueue(byte);
140 } else {
141 MutexLockerEx x(Shared_DirtyCardQ_lock,
142 Mutex::_no_safepoint_check_flag);
143 _dcqs.shared_dirty_card_queue()->enqueue(byte);
144 }
145 }
146 }
147
148 void
149 G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
150 oop new_val) {
151 uintptr_t field_uint = (uintptr_t)field;
152 uintptr_t new_val_uint = cast_from_oop<uintptr_t>(new_val);
153 uintptr_t comb = field_uint ^ new_val_uint;
154 comb = comb >> HeapRegion::LogOfHRGrainBytes;
155 if (comb == 0) return;
156 if (new_val == NULL) return;
157 // Otherwise, log it.
158 G1SATBCardTableLoggingModRefBS* g1_bs =
159 (G1SATBCardTableLoggingModRefBS*)Universe::heap()->barrier_set();
160 g1_bs->write_ref_field_work(field, new_val);
161 }
162
163 void
164 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
165 volatile jbyte* byte = byte_for(mr.start());
166 jbyte* last_byte = byte_for(mr.last());
167 Thread* thr = Thread::current();
168 if (whole_heap) {
169 while (byte <= last_byte) {
170 *byte = dirty_card;
171 byte++;
172 }
173 } else {
174 // skip all consecutive young cards
175 for (; byte <= last_byte && *byte == g1_young_gen; byte++);
176
177 if (byte <= last_byte) {
178 OrderAccess::storeload();
179 // Enqueue if necessary.
180 if (thr->is_Java_thread()) {
181 JavaThread* jt = (JavaThread*)thr;
182 for (; byte <= last_byte; byte++) {
183 if (*byte == g1_young_gen) {
184 continue;
185 }
186 if (*byte != dirty_card) {
187 *byte = dirty_card;
188 jt->dirty_card_queue().enqueue(byte);
189 }
190 }
191 } else {
192 MutexLockerEx x(Shared_DirtyCardQ_lock,
193 Mutex::_no_safepoint_check_flag);
194 for (; byte <= last_byte; byte++) {
195 if (*byte == g1_young_gen) {
196 continue;
197 }
198 if (*byte != dirty_card) {
199 *byte = dirty_card;
200 _dcqs.shared_dirty_card_queue()->enqueue(byte);
201 }
202 }
203 }
204 }
205 }
206 }