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 bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {
70 jbyte val = _byte_map[card_index];
71 // It's already processed
72 if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
73 return false;
74 }
75
76 if (val == g1_young_gen) {
77 // the card is for a young gen region. We don't need to keep track of all pointers into young
78 return false;
79 }
80
81 // Cached bit can be installed either on a clean card or on a claimed card.
82 jbyte new_val = val;
83 if (val == clean_card_val()) {
84 new_val = (jbyte)deferred_card_val();
85 } else {
86 if (val & claimed_card_val()) {
87 new_val = val | (jbyte)deferred_card_val();
88 }
89 }
90 if (new_val != val) {
91 Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
92 }
93 return true;
94 }
95
96 void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) {
97 jbyte *const first = byte_for(mr.start());
98 jbyte *const last = byte_after(mr.last());
99
100 // Below we may use an explicit loop instead of memset() because on
101 // certain platforms memset() can give concurrent readers phantom zeros.
102 if (UseMemSetInBOT) {
103 memset(first, g1_young_gen, last - first);
104 } else {
105 for (jbyte* i = first; i < last; i++) {
106 *i = g1_young_gen;
107 }
108 }
109 }
110
111 #ifndef PRODUCT
112 void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) {
113 verify_region(mr, g1_young_gen, true);
114 }
115 #endif
116
117 G1SATBCardTableLoggingModRefBS::
118 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
119 int max_covered_regions) :
120 G1SATBCardTableModRefBS(whole_heap, max_covered_regions),
121 _dcqs(JavaThread::dirty_card_queue_set())
122 {
123 _kind = G1SATBCTLogging;
124 }
125
126 void
127 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
128 oop new_val,
129 bool release) {
130 volatile jbyte* byte = byte_for(field);
131 if (*byte == g1_young_gen) {
132 return;
133 }
134 OrderAccess::storeload();
135 if (*byte != dirty_card) {
136 *byte = dirty_card;
137 Thread* thr = Thread::current();
138 if (thr->is_Java_thread()) {
139 JavaThread* jt = (JavaThread*)thr;
140 jt->dirty_card_queue().enqueue(byte);
141 } else {
142 MutexLockerEx x(Shared_DirtyCardQ_lock,
143 Mutex::_no_safepoint_check_flag);
144 _dcqs.shared_dirty_card_queue()->enqueue(byte);
145 }
146 }
147 }
148
149 void
150 G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
151 oop new_val) {
152 uintptr_t field_uint = (uintptr_t)field;
153 uintptr_t new_val_uint = cast_from_oop<uintptr_t>(new_val);
154 uintptr_t comb = field_uint ^ new_val_uint;
155 comb = comb >> HeapRegion::LogOfHRGrainBytes;
156 if (comb == 0) return;
157 if (new_val == NULL) return;
158 // Otherwise, log it.
159 G1SATBCardTableLoggingModRefBS* g1_bs =
160 (G1SATBCardTableLoggingModRefBS*)Universe::heap()->barrier_set();
161 g1_bs->write_ref_field_work(field, new_val);
162 }
163
164 void
165 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
166 volatile jbyte* byte = byte_for(mr.start());
167 jbyte* last_byte = byte_for(mr.last());
168 Thread* thr = Thread::current();
169 if (whole_heap) {
170 while (byte <= last_byte) {
171 *byte = dirty_card;
172 byte++;
173 }
174 } else {
175 // skip all consecutive young cards
176 for (; byte <= last_byte && *byte == g1_young_gen; byte++);
177
178 if (byte <= last_byte) {
179 OrderAccess::storeload();
180 // Enqueue if necessary.
181 if (thr->is_Java_thread()) {
182 JavaThread* jt = (JavaThread*)thr;
183 for (; byte <= last_byte; byte++) {
184 if (*byte == g1_young_gen) {
185 continue;
186 }
187 if (*byte != dirty_card) {
188 *byte = dirty_card;
189 jt->dirty_card_queue().enqueue(byte);
190 }
191 }
192 } else {
193 MutexLockerEx x(Shared_DirtyCardQ_lock,
194 Mutex::_no_safepoint_check_flag);
195 for (; byte <= last_byte; byte++) {
196 if (*byte == g1_young_gen) {
197 continue;
198 }
199 if (*byte != dirty_card) {
200 *byte = dirty_card;
201 _dcqs.shared_dirty_card_queue()->enqueue(byte);
202 }
203 }
204 }
205 }
206 }
207 }