1 /*
2 * Copyright (c) 2001, 2019, 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/g1SATBMarkQueueSet.hpp"
31 #include "gc/g1/g1ThreadLocalData.hpp"
32 #include "gc/g1/heapRegion.hpp"
33 #include "gc/shared/satbMarkQueue.hpp"
34 #include "logging/log.hpp"
35 #include "oops/access.inline.hpp"
36 #include "oops/compressedOops.inline.hpp"
37 #include "oops/oop.inline.hpp"
38 #include "runtime/interfaceSupport.inline.hpp"
39 #include "runtime/mutexLocker.hpp"
40 #include "runtime/thread.inline.hpp"
41 #include "utilities/macros.hpp"
42 #ifdef COMPILER1
43 #include "gc/g1/c1/g1BarrierSetC1.hpp"
44 #endif
45 #ifdef COMPILER2
46 #include "gc/g1/c2/g1BarrierSetC2.hpp"
47 #endif
48
49 class G1BarrierSetC1;
50 class G1BarrierSetC2;
51
52 G1BarrierSet::G1BarrierSet(G1CardTable* card_table) :
53 CardTableBarrierSet(make_barrier_set_assembler<G1BarrierSetAssembler>(),
54 make_barrier_set_c1<G1BarrierSetC1>(),
55 make_barrier_set_c2<G1BarrierSetC2>(),
56 card_table,
57 BarrierSet::FakeRtti(BarrierSet::G1BarrierSet)),
58 _satb_mark_queue_buffer_allocator("SATB Buffer Allocator", G1SATBBufferSize),
59 _dirty_card_queue_buffer_allocator("DC Buffer Allocator", G1UpdateBufferSize),
60 _satb_mark_queue_set(),
61 _dirty_card_queue_set()
62 {}
63
64 void G1BarrierSet::enqueue(oop pre_val) {
65 // Nulls should have been already filtered.
66 assert(oopDesc::is_oop(pre_val, true), "Error");
67
68 G1SATBMarkQueueSet& queue_set = satb_mark_queue_set();
69 if (!queue_set.is_active()) {
70 return;
71 }
72 Thread* thr = Thread::current();
73 if (thr->is_Java_thread()) {
74 G1ThreadLocalData::satb_mark_queue(thr).enqueue(pre_val);
75 } else {
76 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag);
77 queue_set.shared_satb_queue()->enqueue(pre_val);
78 }
79 }
80
81 template <class T> void
82 G1BarrierSet::write_ref_array_pre_work(T* dst, size_t count) {
83 if (!_satb_mark_queue_set.is_active()) return;
84 T* elem_ptr = dst;
85 for (size_t i = 0; i < count; i++, elem_ptr++) {
86 T heap_oop = RawAccess<>::oop_load(elem_ptr);
87 if (!CompressedOops::is_null(heap_oop)) {
88 enqueue(CompressedOops::decode_not_null(heap_oop));
89 }
90 }
91 }
92
93 void G1BarrierSet::write_ref_array_pre(oop* 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_array_pre(narrowOop* dst, size_t count, bool dest_uninitialized) {
100 if (!dest_uninitialized) {
101 write_ref_array_pre_work(dst, count);
102 }
103 }
104
105 void G1BarrierSet::write_ref_field_post_slow(volatile jbyte* byte) {
106 // In the slow path, we know a card is not young
107 assert(*byte != G1CardTable::g1_young_card_val(), "slow path invoked without filtering");
108 OrderAccess::storeload();
109 if (*byte != G1CardTable::dirty_card_val()) {
110 *byte = G1CardTable::dirty_card_val();
111 Thread* thr = Thread::current();
112 if (thr->is_Java_thread()) {
113 G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte);
114 } else {
115 MutexLockerEx x(Shared_DirtyCardQ_lock,
116 Mutex::_no_safepoint_check_flag);
117 _dirty_card_queue_set.shared_dirty_card_queue()->enqueue(byte);
118 }
119 }
120 }
121
122 void G1BarrierSet::invalidate(MemRegion mr) {
123 if (mr.is_empty()) {
124 return;
125 }
126 volatile jbyte* byte = _card_table->byte_for(mr.start());
127 jbyte* last_byte = _card_table->byte_for(mr.last());
128 Thread* thr = Thread::current();
129 // skip all consecutive young cards
130 for (; byte <= last_byte && *byte == G1CardTable::g1_young_card_val(); byte++);
131
132 if (byte <= last_byte) {
133 OrderAccess::storeload();
134 // Enqueue if necessary.
135 if (thr->is_Java_thread()) {
136 for (; byte <= last_byte; byte++) {
137 if (*byte == G1CardTable::g1_young_card_val()) {
138 continue;
139 }
140 if (*byte != G1CardTable::dirty_card_val()) {
141 *byte = G1CardTable::dirty_card_val();
142 G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte);
143 }
144 }
145 } else {
146 MutexLockerEx x(Shared_DirtyCardQ_lock,
147 Mutex::_no_safepoint_check_flag);
148 for (; byte <= last_byte; byte++) {
149 if (*byte == G1CardTable::g1_young_card_val()) {
150 continue;
151 }
152 if (*byte != G1CardTable::dirty_card_val()) {
153 *byte = G1CardTable::dirty_card_val();
154 _dirty_card_queue_set.shared_dirty_card_queue()->enqueue(byte);
155 }
156 }
157 }
158 }
159 }
160
161 void G1BarrierSet::on_thread_create(Thread* thread) {
162 // Create thread local data
163 G1ThreadLocalData::create(thread);
164 }
165
166 void G1BarrierSet::on_thread_destroy(Thread* thread) {
167 // Destroy thread local data
168 G1ThreadLocalData::destroy(thread);
169 }
170
171 void G1BarrierSet::on_thread_attach(JavaThread* thread) {
172 // This method initializes the SATB and dirty card queues before a
173 // JavaThread is added to the Java thread list. Right now, we don't
174 // have to do anything to the dirty card queue (it should have been
175 // activated when the thread was created), but we have to activate
176 // the SATB queue if the thread is created while a marking cycle is
177 // in progress. The activation / de-activation of the SATB queues at
178 // the beginning / end of a marking cycle is done during safepoints
179 // so we have to make sure this method is called outside one to be
180 // able to safely read the active field of the SATB queue set. Right
181 // now, it is called just before the thread is added to the Java
182 // thread list in the Threads::add() method. That method is holding
183 // the Threads_lock which ensures we are outside a safepoint. We
184 // cannot do the obvious and set the active field of the SATB queue
185 // when the thread is created given that, in some cases, safepoints
186 // might happen between the JavaThread constructor being called and the
187 // thread being added to the Java thread list (an example of this is
188 // when the structure for the DestroyJavaVM thread is created).
189 assert(!SafepointSynchronize::is_at_safepoint(), "We should not be at a safepoint");
190 assert(!G1ThreadLocalData::satb_mark_queue(thread).is_active(), "SATB queue should not be active");
191 assert(G1ThreadLocalData::satb_mark_queue(thread).is_empty(), "SATB queue should be empty");
192 assert(G1ThreadLocalData::dirty_card_queue(thread).is_active(), "Dirty card queue should be active");
193
194 // If we are creating the thread during a marking cycle, we should
195 // set the active field of the SATB queue to true.
196 if (_satb_mark_queue_set.is_active()) {
197 G1ThreadLocalData::satb_mark_queue(thread).set_active(true);
198 }
199 }
200
201 void G1BarrierSet::on_thread_detach(JavaThread* thread) {
202 // Flush any deferred card marks, SATB buffers and dirty card queue buffers
203 CardTableBarrierSet::on_thread_detach(thread);
204 G1ThreadLocalData::satb_mark_queue(thread).flush();
205 G1ThreadLocalData::dirty_card_queue(thread).flush();
206 }
207
208 BufferNode::Allocator& G1BarrierSet::satb_mark_queue_buffer_allocator() {
209 return _satb_mark_queue_buffer_allocator;
210 }
211
212 BufferNode::Allocator& G1BarrierSet::dirty_card_queue_buffer_allocator() {
213 return _dirty_card_queue_buffer_allocator;
214 }