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/g1CollectedHeap.inline.hpp"
27 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
28 #include "gc_implementation/g1/heapRegion.hpp"
29 #include "gc_implementation/g1/satbQueue.hpp"
30 #include "runtime/atomic.inline.hpp"
31 #include "runtime/mutexLocker.hpp"
32 #include "runtime/orderAccess.inline.hpp"
33 #include "runtime/thread.inline.hpp"
34
35 G1SATBCardTableModRefBS::G1SATBCardTableModRefBS(MemRegion whole_heap) :
36 CardTableModRefBS(whole_heap)
37 {
38 _kind = G1SATBCT;
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 void G1SATBCardTableModRefBS::write_ref_array_pre(oop* dst, int count, bool dest_uninitialized) {
69 if (!dest_uninitialized) {
70 write_ref_array_pre_work(dst, count);
71 }
72 }
73 void G1SATBCardTableModRefBS::write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized) {
74 if (!dest_uninitialized) {
75 write_ref_array_pre_work(dst, count);
76 }
77 }
78
79 bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {
80 jbyte val = _byte_map[card_index];
81 // It's already processed
82 if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
83 return false;
84 }
85
86 if (val == g1_young_gen) {
87 // the card is for a young gen region. We don't need to keep track of all pointers into young
88 return false;
89 }
90
91 // Cached bit can be installed either on a clean card or on a claimed card.
92 jbyte new_val = val;
93 if (val == clean_card_val()) {
94 new_val = (jbyte)deferred_card_val();
95 } else {
96 if (val & claimed_card_val()) {
97 new_val = val | (jbyte)deferred_card_val();
98 }
99 }
100 if (new_val != val) {
101 Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
102 }
103 return true;
104 }
105
106 void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) {
107 jbyte *const first = byte_for(mr.start());
108 jbyte *const last = byte_after(mr.last());
109
110 // Below we may use an explicit loop instead of memset() because on
111 // certain platforms memset() can give concurrent readers phantom zeros.
112 if (UseMemSetInBOT) {
113 memset(first, g1_young_gen, last - first);
114 } else {
115 for (jbyte* i = first; i < last; i++) {
116 *i = g1_young_gen;
117 }
118 }
119 }
120
121 #ifndef PRODUCT
122 void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) {
123 verify_region(mr, g1_young_gen, true);
124 }
125 #endif
126
127 void G1SATBCardTableLoggingModRefBSChangedListener::on_commit(uint start_idx, size_t num_regions, bool zero_filled) {
128 // Default value for a clean card on the card table is -1. So we cannot take advantage of the zero_filled parameter.
129 MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_idx), num_regions * HeapRegion::GrainWords);
130 _card_table->clear(mr);
131 }
132
133 G1SATBCardTableLoggingModRefBS::
134 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap) :
135 G1SATBCardTableModRefBS(whole_heap),
136 _dcqs(JavaThread::dirty_card_queue_set()),
137 _listener()
138 {
139 _kind = G1SATBCTLogging;
140 _listener.set_card_table(this);
141 }
142
143 void G1SATBCardTableLoggingModRefBS::initialize(G1RegionToSpaceMapper* mapper) {
144 mapper->set_mapping_changed_listener(&_listener);
145
146 _byte_map_size = mapper->reserved().byte_size();
147
148 _guard_index = cards_required(_whole_heap.word_size()) - 1;
149 _last_valid_index = _guard_index - 1;
150
151 HeapWord* low_bound = _whole_heap.start();
152 HeapWord* high_bound = _whole_heap.end();
153
154 _cur_covered_regions = 1;
155 _covered[0] = _whole_heap;
156
157 _byte_map = (jbyte*) mapper->reserved().start();
158 byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift);
159 assert(byte_for(low_bound) == &_byte_map[0], "Checking start of map");
160 assert(byte_for(high_bound-1) <= &_byte_map[_last_valid_index], "Checking end of map");
161
162 if (TraceCardTableModRefBS) {
163 gclog_or_tty->print_cr("G1SATBCardTableModRefBS::G1SATBCardTableModRefBS: ");
164 gclog_or_tty->print_cr(" "
165 " &_byte_map[0]: " INTPTR_FORMAT
166 " &_byte_map[_last_valid_index]: " INTPTR_FORMAT,
167 p2i(&_byte_map[0]),
168 p2i(&_byte_map[_last_valid_index]));
169 gclog_or_tty->print_cr(" "
170 " byte_map_base: " INTPTR_FORMAT,
171 p2i(byte_map_base));
172 }
173 }
174
175 void
176 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
177 oop new_val,
178 bool release) {
179 volatile jbyte* byte = byte_for(field);
180 if (*byte == g1_young_gen) {
181 return;
182 }
183 OrderAccess::storeload();
184 if (*byte != dirty_card) {
185 *byte = dirty_card;
186 Thread* thr = Thread::current();
187 if (thr->is_Java_thread()) {
188 JavaThread* jt = (JavaThread*)thr;
189 jt->dirty_card_queue().enqueue(byte);
190 } else {
191 MutexLockerEx x(Shared_DirtyCardQ_lock,
192 Mutex::_no_safepoint_check_flag);
193 _dcqs.shared_dirty_card_queue()->enqueue(byte);
194 }
195 }
196 }
197
198 void
199 G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
200 oop new_val) {
201 uintptr_t field_uint = (uintptr_t)field;
202 uintptr_t new_val_uint = cast_from_oop<uintptr_t>(new_val);
203 uintptr_t comb = field_uint ^ new_val_uint;
204 comb = comb >> HeapRegion::LogOfHRGrainBytes;
205 if (comb == 0) return;
206 if (new_val == NULL) return;
207 // Otherwise, log it.
208 G1SATBCardTableLoggingModRefBS* g1_bs =
209 (G1SATBCardTableLoggingModRefBS*)Universe::heap()->barrier_set();
210 g1_bs->write_ref_field_work(field, new_val);
211 }
212
213 void
214 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
215 volatile jbyte* byte = byte_for(mr.start());
216 jbyte* last_byte = byte_for(mr.last());
217 Thread* thr = Thread::current();
218 if (whole_heap) {
219 while (byte <= last_byte) {
220 *byte = dirty_card;
221 byte++;
222 }
223 } else {
224 // skip all consecutive young cards
225 for (; byte <= last_byte && *byte == g1_young_gen; byte++);
226
227 if (byte <= last_byte) {
228 OrderAccess::storeload();
229 // Enqueue if necessary.
230 if (thr->is_Java_thread()) {
231 JavaThread* jt = (JavaThread*)thr;
232 for (; byte <= last_byte; byte++) {
233 if (*byte == g1_young_gen) {
234 continue;
235 }
236 if (*byte != dirty_card) {
237 *byte = dirty_card;
238 jt->dirty_card_queue().enqueue(byte);
239 }
240 }
241 } else {
242 MutexLockerEx x(Shared_DirtyCardQ_lock,
243 Mutex::_no_safepoint_check_flag);
244 for (; byte <= last_byte; byte++) {
245 if (*byte == g1_young_gen) {
246 continue;
247 }
248 if (*byte != dirty_card) {
249 *byte = dirty_card;
250 _dcqs.shared_dirty_card_queue()->enqueue(byte);
251 }
252 }
253 }
254 }
255 }
256 }