1 /*
2 * Copyright (c) 2001, 2018, 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/g1/g1BarrierSet.inline.hpp"
27 #include "gc/g1/g1BarrierSetAssembler.hpp"
28 #include "gc/g1/g1CardTable.inline.hpp"
29 #include "gc/g1/g1CollectedHeap.inline.hpp"
30 #include "gc/g1/g1ThreadLocalData.hpp"
31 #include "gc/g1/heapRegion.hpp"
32 #include "gc/g1/satbMarkQueue.hpp"
33 #include "logging/log.hpp"
34 #include "oops/access.inline.hpp"
35 #include "oops/compressedOops.inline.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "runtime/interfaceSupport.inline.hpp"
38 #include "runtime/mutexLocker.hpp"
39 #include "runtime/thread.inline.hpp"
40 #include "utilities/macros.hpp"
41 #ifdef COMPILER1
42 #include "gc/g1/c1/g1BarrierSetC1.hpp"
43 #endif
44 #ifdef COMPILER2
45 #include "gc/g1/c2/g1BarrierSetC2.hpp"
46 #endif
47
48 class G1BarrierSetC1;
49 class G1BarrierSetC2;
50
51 SATBMarkQueueSet G1BarrierSet::_satb_mark_queue_set;
52 DirtyCardQueueSet G1BarrierSet::_dirty_card_queue_set;
53
54 G1BarrierSet::G1BarrierSet(G1CardTable* card_table) :
55 CardTableBarrierSet(make_barrier_set_assembler<G1BarrierSetAssembler>(),
56 make_barrier_set_c1<G1BarrierSetC1>(),
57 make_barrier_set_c2<G1BarrierSetC2>(),
58 card_table,
59 BarrierSet::FakeRtti(BarrierSet::G1BarrierSet)) {}
60
61 void G1BarrierSet::enqueue(oop pre_val) {
62 // Nulls should have been already filtered.
63 assert(oopDesc::is_oop(pre_val, true), "Error");
64
65 if (!_satb_mark_queue_set.is_active()) return;
66 Thread* thr = Thread::current();
67 if (thr->is_Java_thread()) {
68 G1ThreadLocalData::satb_mark_queue(thr).enqueue(pre_val);
69 } else {
70 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag);
71 _satb_mark_queue_set.shared_satb_queue()->enqueue(pre_val);
72 }
73 }
74
75 template <class T> void
76 G1BarrierSet::write_ref_array_pre_work(T* dst, size_t count) {
77 if (!_satb_mark_queue_set.is_active()) return;
78 T* elem_ptr = dst;
79 for (size_t i = 0; i < count; i++, elem_ptr++) {
80 T heap_oop = RawAccess<>::oop_load(elem_ptr);
81 if (!CompressedOops::is_null(heap_oop)) {
82 enqueue(CompressedOops::decode_not_null(heap_oop));
83 }
84 }
85 }
86
87 void G1BarrierSet::write_ref_array_pre(oop* dst, size_t count, bool dest_uninitialized) {
88 if (!dest_uninitialized) {
89 write_ref_array_pre_work(dst, count);
90 }
91 }
92
93 void G1BarrierSet::write_ref_array_pre(narrowOop* dst, size_t count, bool dest_uninitialized) {
94 if (!dest_uninitialized) {
95 write_ref_array_pre_work(dst, count);
96 }
97 }
98
99 void G1BarrierSet::write_ref_field_post_slow(volatile jbyte* byte) {
100 // In the slow path, we know a card is not young
101 assert(*byte != G1CardTable::g1_young_card_val(), "slow path invoked without filtering");
102 OrderAccess::storeload();
103 if (*byte != G1CardTable::dirty_card_val()) {
104 *byte = G1CardTable::dirty_card_val();
105 Thread* thr = Thread::current();
106 if (thr->is_Java_thread()) {
107 G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte);
108 } else {
109 MutexLockerEx x(Shared_DirtyCardQ_lock,
110 Mutex::_no_safepoint_check_flag);
111 _dirty_card_queue_set.shared_dirty_card_queue()->enqueue(byte);
112 }
113 }
114 }
115
116 void G1BarrierSet::invalidate(MemRegion mr) {
117 if (mr.is_empty()) {
118 return;
119 }
120 volatile jbyte* byte = _card_table->byte_for(mr.start());
121 jbyte* last_byte = _card_table->byte_for(mr.last());
122 Thread* thr = Thread::current();
123 // skip all consecutive young cards
124 for (; byte <= last_byte && *byte == G1CardTable::g1_young_card_val(); byte++);
125
126 if (byte <= last_byte) {
127 OrderAccess::storeload();
128 // Enqueue if necessary.
129 if (thr->is_Java_thread()) {
130 for (; byte <= last_byte; byte++) {
131 if (*byte == G1CardTable::g1_young_card_val()) {
132 continue;
133 }
134 if (*byte != G1CardTable::dirty_card_val()) {
135 *byte = G1CardTable::dirty_card_val();
136 G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte);
137 }
138 }
139 } else {
140 MutexLockerEx x(Shared_DirtyCardQ_lock,
141 Mutex::_no_safepoint_check_flag);
142 for (; byte <= last_byte; byte++) {
143 if (*byte == G1CardTable::g1_young_card_val()) {
144 continue;
145 }
146 if (*byte != G1CardTable::dirty_card_val()) {
147 *byte = G1CardTable::dirty_card_val();
148 _dirty_card_queue_set.shared_dirty_card_queue()->enqueue(byte);
149 }
150 }
151 }
152 }
153 }
154
155 void G1BarrierSet::on_thread_create(Thread* thread) {
156 // Create thread local data
157 G1ThreadLocalData::create(thread);
158 }
159
160 void G1BarrierSet::on_thread_destroy(Thread* thread) {
161 // Destroy thread local data
162 G1ThreadLocalData::destroy(thread);
163 }
164
165 void G1BarrierSet::on_thread_attach(JavaThread* thread) {
166 // This method initializes the SATB and dirty card queues before a
167 // JavaThread is added to the Java thread list. Right now, we don't
168 // have to do anything to the dirty card queue (it should have been
169 // activated when the thread was created), but we have to activate
170 // the SATB queue if the thread is created while a marking cycle is
171 // in progress. The activation / de-activation of the SATB queues at
172 // the beginning / end of a marking cycle is done during safepoints
173 // so we have to make sure this method is called outside one to be
174 // able to safely read the active field of the SATB queue set. Right
175 // now, it is called just before the thread is added to the Java
176 // thread list in the Threads::add() method. That method is holding
177 // the Threads_lock which ensures we are outside a safepoint. We
178 // cannot do the obvious and set the active field of the SATB queue
179 // when the thread is created given that, in some cases, safepoints
180 // might happen between the JavaThread constructor being called and the
181 // thread being added to the Java thread list (an example of this is
182 // when the structure for the DestroyJavaVM thread is created).
183 assert(!SafepointSynchronize::is_at_safepoint(), "We should not be at a safepoint");
184 assert(!G1ThreadLocalData::satb_mark_queue(thread).is_active(), "SATB queue should not be active");
185 assert(G1ThreadLocalData::satb_mark_queue(thread).is_empty(), "SATB queue should be empty");
186 assert(G1ThreadLocalData::dirty_card_queue(thread).is_active(), "Dirty card queue should be active");
187
188 // If we are creating the thread during a marking cycle, we should
189 // set the active field of the SATB queue to true.
190 if (_satb_mark_queue_set.is_active()) {
191 G1ThreadLocalData::satb_mark_queue(thread).set_active(true);
192 }
193 }
194
195 void G1BarrierSet::on_thread_detach(JavaThread* thread) {
196 // Flush any deferred card marks, SATB buffers and dirty card queue buffers
197 CardTableBarrierSet::on_thread_detach(thread);
198 G1ThreadLocalData::satb_mark_queue(thread).flush();
199 G1ThreadLocalData::dirty_card_queue(thread).flush();
200 }