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/atomic.inline.hpp"
30 #include "runtime/mutexLocker.hpp"
31 #include "runtime/orderAccess.inline.hpp"
32 #include "runtime/thread.inline.hpp"
33
34 G1SATBCardTableModRefBS::G1SATBCardTableModRefBS(MemRegion whole_heap,
35 int max_covered_regions) :
36 CardTableModRefBSForCTRS(whole_heap, max_covered_regions)
37 {
38 _kind = G1SATBCT;
39 }
40
41
42 void G1SATBCardTableModRefBS::enqueue(oop pre_val) {
43 // Nulls should have been already filtered.
44 assert(pre_val->is_oop(true), "Error");
45
46 if (!JavaThread::satb_mark_queue_set().is_active()) return;
47 Thread* thr = Thread::current();
48 if (thr->is_Java_thread()) {
49 JavaThread* jt = (JavaThread*)thr;
50 jt->satb_mark_queue().enqueue(pre_val);
51 } else {
52 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag);
53 JavaThread::satb_mark_queue_set().shared_satb_queue()->enqueue(pre_val);
54 }
55 }
56
57 template <class T> void
58 G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) {
59 if (!JavaThread::satb_mark_queue_set().is_active()) return;
60 T* elem_ptr = dst;
61 for (int i = 0; i < count; i++, elem_ptr++) {
62 T heap_oop = oopDesc::load_heap_oop(elem_ptr);
63 if (!oopDesc::is_null(heap_oop)) {
64 enqueue(oopDesc::decode_heap_oop_not_null(heap_oop));
65 }
66 }
67 }
68
69 void G1SATBCardTableModRefBS::write_ref_array_pre(oop* dst, int count, bool dest_uninitialized) {
70 if (!dest_uninitialized) {
71 write_ref_array_pre_work(dst, count);
72 }
73 }
74 void G1SATBCardTableModRefBS::write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized) {
75 if (!dest_uninitialized) {
76 write_ref_array_pre_work(dst, count);
77 }
78 }
79
80 bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {
81 jbyte val = _byte_map[card_index];
82 // It's already processed
83 if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
84 return false;
85 }
86
87 if (val == g1_young_gen) {
88 // the card is for a young gen region. We don't need to keep track of all pointers into young
89 return false;
90 }
91
92 // Cached bit can be installed either on a clean card or on a claimed card.
93 jbyte new_val = val;
94 if (val == clean_card_val()) {
95 new_val = (jbyte)deferred_card_val();
96 } else {
97 if (val & claimed_card_val()) {
98 new_val = val | (jbyte)deferred_card_val();
99 }
100 }
101 if (new_val != val) {
102 Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
103 }
104 return true;
105 }
106
107 void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) {
108 jbyte *const first = byte_for(mr.start());
109 jbyte *const last = byte_after(mr.last());
110
111 // Below we may use an explicit loop instead of memset() because on
112 // certain platforms memset() can give concurrent readers phantom zeros.
113 if (UseMemSetInBOT) {
114 memset(first, g1_young_gen, last - first);
115 } else {
116 for (jbyte* i = first; i < last; i++) {
117 *i = g1_young_gen;
118 }
119 }
120 }
121
122 #ifndef PRODUCT
123 void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) {
124 verify_region(mr, g1_young_gen, true);
125 }
126 #endif
127
128 G1SATBCardTableLoggingModRefBS::
129 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
130 int max_covered_regions) :
131 G1SATBCardTableModRefBS(whole_heap, max_covered_regions),
132 _dcqs(JavaThread::dirty_card_queue_set())
133 {
134 _kind = G1SATBCTLogging;
135 }
136
137 void
138 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
139 oop new_val,
140 bool release) {
141 volatile jbyte* byte = byte_for(field);
142 if (*byte == g1_young_gen) {
143 return;
144 }
145 OrderAccess::storeload();
146 if (*byte != dirty_card) {
147 *byte = dirty_card;
148 Thread* thr = Thread::current();
149 if (thr->is_Java_thread()) {
150 JavaThread* jt = (JavaThread*)thr;
151 jt->dirty_card_queue().enqueue(byte);
152 } else {
153 MutexLockerEx x(Shared_DirtyCardQ_lock,
154 Mutex::_no_safepoint_check_flag);
155 _dcqs.shared_dirty_card_queue()->enqueue(byte);
156 }
157 }
158 }
159
160 void
161 G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
162 oop new_val) {
163 uintptr_t field_uint = (uintptr_t)field;
164 uintptr_t new_val_uint = cast_from_oop<uintptr_t>(new_val);
165 uintptr_t comb = field_uint ^ new_val_uint;
166 comb = comb >> HeapRegion::LogOfHRGrainBytes;
167 if (comb == 0) return;
168 if (new_val == NULL) return;
169 // Otherwise, log it.
170 G1SATBCardTableLoggingModRefBS* g1_bs =
171 (G1SATBCardTableLoggingModRefBS*)Universe::heap()->barrier_set();
172 g1_bs->write_ref_field_work(field, new_val);
173 }
174
175 void
176 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
177 volatile jbyte* byte = byte_for(mr.start());
178 jbyte* last_byte = byte_for(mr.last());
179 Thread* thr = Thread::current();
180 if (whole_heap) {
181 while (byte <= last_byte) {
182 *byte = dirty_card;
183 byte++;
184 }
185 } else {
186 // skip all consecutive young cards
187 for (; byte <= last_byte && *byte == g1_young_gen; byte++);
188
189 if (byte <= last_byte) {
190 OrderAccess::storeload();
191 // Enqueue if necessary.
192 if (thr->is_Java_thread()) {
193 JavaThread* jt = (JavaThread*)thr;
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 jt->dirty_card_queue().enqueue(byte);
201 }
202 }
203 } else {
204 MutexLockerEx x(Shared_DirtyCardQ_lock,
205 Mutex::_no_safepoint_check_flag);
206 for (; byte <= last_byte; byte++) {
207 if (*byte == g1_young_gen) {
208 continue;
209 }
210 if (*byte != dirty_card) {
211 *byte = dirty_card;
212 _dcqs.shared_dirty_card_queue()->enqueue(byte);
213 }
214 }
215 }
216 }
217 }
218 }