1 /*
2 * Copyright (c) 2001, 2015, 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 "oops/oop.inline.hpp"
31 #include "runtime/atomic.inline.hpp"
32 #include "runtime/mutexLocker.hpp"
33 #include "runtime/orderAccess.inline.hpp"
34 #include "runtime/thread.inline.hpp"
35
36 G1SATBCardTableModRefBS::G1SATBCardTableModRefBS(MemRegion whole_heap, BarrierSet::Name kind) :
37 CardTableModRefBS(whole_heap, kind) { }
38
39 void G1SATBCardTableModRefBS::enqueue(oop pre_val) {
40 // Nulls should have been already filtered.
41 assert(pre_val->is_oop(true), "Error");
42
43 if (!JavaThread::satb_mark_queue_set().is_active()) return;
44 Thread* thr = Thread::current();
45 if (thr->is_Java_thread()) {
46 JavaThread* jt = (JavaThread*)thr;
47 jt->satb_mark_queue().enqueue(pre_val);
48 } else {
49 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag);
50 JavaThread::satb_mark_queue_set().shared_satb_queue()->enqueue(pre_val);
51 }
52 }
53
54 template <class T> void
55 G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) {
56 if (!JavaThread::satb_mark_queue_set().is_active()) return;
57 T* elem_ptr = dst;
58 for (int i = 0; i < count; i++, elem_ptr++) {
59 T heap_oop = oopDesc::load_heap_oop(elem_ptr);
60 if (!oopDesc::is_null(heap_oop)) {
61 enqueue(oopDesc::decode_heap_oop_not_null(heap_oop));
62 }
63 }
64 }
65
66 void G1SATBCardTableModRefBS::write_ref_array_pre(oop* dst, int count, bool dest_uninitialized) {
67 if (!dest_uninitialized) {
68 write_ref_array_pre_work(dst, count);
69 }
70 }
71 void G1SATBCardTableModRefBS::write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized) {
72 if (!dest_uninitialized) {
73 write_ref_array_pre_work(dst, count);
74 }
75 }
76
77 bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {
78 jbyte val = _byte_map[card_index];
79 // It's already processed
80 if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
81 return false;
82 }
83
84 if (val == g1_young_gen) {
85 // the card is for a young gen region. We don't need to keep track of all pointers into young
86 return false;
87 }
88
89 // Cached bit can be installed either on a clean card or on a claimed card.
90 jbyte new_val = val;
91 if (val == clean_card_val()) {
92 new_val = (jbyte)deferred_card_val();
93 } else {
94 if (val & claimed_card_val()) {
95 new_val = val | (jbyte)deferred_card_val();
96 }
97 }
98 if (new_val != val) {
99 Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
100 }
101 return true;
102 }
103
104 void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) {
105 jbyte *const first = byte_for(mr.start());
106 jbyte *const last = byte_after(mr.last());
107
108 // Below we may use an explicit loop instead of memset() because on
109 // certain platforms memset() can give concurrent readers phantom zeros.
110 if (UseMemSetInBOT) {
111 memset(first, g1_young_gen, last - first);
112 } else {
113 for (jbyte* i = first; i < last; i++) {
114 *i = g1_young_gen;
115 }
116 }
117 }
118
119 #ifndef PRODUCT
120 void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) {
121 verify_region(mr, g1_young_gen, true);
122 }
123 #endif
124
125 void G1SATBCardTableLoggingModRefBSChangedListener::on_commit(uint start_idx, size_t num_regions, bool zero_filled) {
126 // Default value for a clean card on the card table is -1. So we cannot take advantage of the zero_filled parameter.
127 MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_idx), num_regions * HeapRegion::GrainWords);
128 _card_table->clear(mr);
129 }
130
131 G1SATBCardTableLoggingModRefBS::
132 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap) :
133 G1SATBCardTableModRefBS(whole_heap, BarrierSet::G1SATBCTLogging),
134 _dcqs(JavaThread::dirty_card_queue_set()),
135 _listener()
136 {
137 _listener.set_card_table(this);
138 }
139
140 void G1SATBCardTableLoggingModRefBS::initialize(G1RegionToSpaceMapper* mapper) {
141 mapper->set_mapping_changed_listener(&_listener);
142
143 _byte_map_size = mapper->reserved().byte_size();
144
145 _guard_index = cards_required(_whole_heap.word_size()) - 1;
146 _last_valid_index = _guard_index - 1;
147
148 HeapWord* low_bound = _whole_heap.start();
149 HeapWord* high_bound = _whole_heap.end();
150
151 _cur_covered_regions = 1;
152 _covered[0] = _whole_heap;
153
154 _byte_map = (jbyte*) mapper->reserved().start();
155 byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift);
156 assert(byte_for(low_bound) == &_byte_map[0], "Checking start of map");
157 assert(byte_for(high_bound-1) <= &_byte_map[_last_valid_index], "Checking end of map");
158
159 if (TraceCardTableModRefBS) {
160 gclog_or_tty->print_cr("G1SATBCardTableModRefBS::G1SATBCardTableModRefBS: ");
161 gclog_or_tty->print_cr(" "
162 " &_byte_map[0]: " INTPTR_FORMAT
163 " &_byte_map[_last_valid_index]: " INTPTR_FORMAT,
164 p2i(&_byte_map[0]),
165 p2i(&_byte_map[_last_valid_index]));
166 gclog_or_tty->print_cr(" "
167 " byte_map_base: " INTPTR_FORMAT,
168 p2i(byte_map_base));
169 }
170 }
171
172 void
173 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
174 oop new_val,
175 bool release) {
176 volatile jbyte* byte = byte_for(field);
177 if (*byte == g1_young_gen) {
178 return;
179 }
180 OrderAccess::storeload();
181 if (*byte != dirty_card) {
182 *byte = dirty_card;
183 Thread* thr = Thread::current();
184 if (thr->is_Java_thread()) {
185 JavaThread* jt = (JavaThread*)thr;
186 jt->dirty_card_queue().enqueue(byte);
187 } else {
188 MutexLockerEx x(Shared_DirtyCardQ_lock,
189 Mutex::_no_safepoint_check_flag);
190 _dcqs.shared_dirty_card_queue()->enqueue(byte);
191 }
192 }
193 }
194
195 void
196 G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
197 oop new_val) {
198 uintptr_t field_uint = (uintptr_t)field;
199 uintptr_t new_val_uint = cast_from_oop<uintptr_t>(new_val);
200 uintptr_t comb = field_uint ^ new_val_uint;
201 comb = comb >> HeapRegion::LogOfHRGrainBytes;
202 if (comb == 0) return;
203 if (new_val == NULL) return;
204 // Otherwise, log it.
205 G1SATBCardTableLoggingModRefBS* g1_bs =
206 (G1SATBCardTableLoggingModRefBS*)Universe::heap()->barrier_set();
207 g1_bs->write_ref_field_work(field, new_val);
208 }
209
210 void
211 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
212 volatile jbyte* byte = byte_for(mr.start());
213 jbyte* last_byte = byte_for(mr.last());
214 Thread* thr = Thread::current();
215 if (whole_heap) {
216 while (byte <= last_byte) {
217 *byte = dirty_card;
218 byte++;
219 }
220 } else {
221 // skip all consecutive young cards
222 for (; byte <= last_byte && *byte == g1_young_gen; byte++);
223
224 if (byte <= last_byte) {
225 OrderAccess::storeload();
226 // Enqueue if necessary.
227 if (thr->is_Java_thread()) {
228 JavaThread* jt = (JavaThread*)thr;
229 for (; byte <= last_byte; byte++) {
230 if (*byte == g1_young_gen) {
231 continue;
232 }
233 if (*byte != dirty_card) {
234 *byte = dirty_card;
235 jt->dirty_card_queue().enqueue(byte);
236 }
237 }
238 } else {
239 MutexLockerEx x(Shared_DirtyCardQ_lock,
240 Mutex::_no_safepoint_check_flag);
241 for (; byte <= last_byte; byte++) {
242 if (*byte == g1_young_gen) {
243 continue;
244 }
245 if (*byte != dirty_card) {
246 *byte = dirty_card;
247 _dcqs.shared_dirty_card_queue()->enqueue(byte);
248 }
249 }
250 }
251 }
252 }
253 }