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/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_set(),
59 _dirty_card_queue_set()
60 {}
61
62 void G1BarrierSet::enqueue(oop pre_val) {
63 // Nulls should have been already filtered.
64 assert(oopDesc::is_oop(pre_val, true), "Error");
65
66 G1SATBMarkQueueSet& queue_set = satb_mark_queue_set();
67 if (!queue_set.is_active()) {
68 return;
69 }
70 Thread* thr = Thread::current();
71 if (thr->is_Java_thread()) {
72 G1ThreadLocalData::satb_mark_queue(thr).enqueue(pre_val);
73 } else {
74 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag);
75 queue_set.shared_satb_queue()->enqueue(pre_val);
76 }
77 }
78
79 template <class T> void
80 G1BarrierSet::write_ref_array_pre_work(T* dst, size_t count) {
81 if (!_satb_mark_queue_set.is_active()) return;
82 T* elem_ptr = dst;
83 for (size_t i = 0; i < count; i++, elem_ptr++) {
84 T heap_oop = RawAccess<>::oop_load(elem_ptr);
85 if (!CompressedOops::is_null(heap_oop)) {
86 enqueue(CompressedOops::decode_not_null(heap_oop));
87 }
88 }
89 }
90
91 void G1BarrierSet::write_ref_array_pre(oop* dst, size_t count, bool dest_uninitialized) {
92 if (!dest_uninitialized) {
93 write_ref_array_pre_work(dst, count);
94 }
95 }
96
97 void G1BarrierSet::write_ref_array_pre(narrowOop* dst, size_t count, bool dest_uninitialized) {
98 if (!dest_uninitialized) {
99 write_ref_array_pre_work(dst, count);
100 }
101 }
102
103 void G1BarrierSet::write_ref_field_post_slow(volatile jbyte* byte) {
104 // In the slow path, we know a card is not young
105 assert(*byte != G1CardTable::g1_young_card_val(), "slow path invoked without filtering");
106 OrderAccess::storeload();
107 if (*byte != G1CardTable::dirty_card_val()) {
108 *byte = G1CardTable::dirty_card_val();
109 Thread* thr = Thread::current();
110 if (thr->is_Java_thread()) {
111 G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte);
112 } else {
113 MutexLockerEx x(Shared_DirtyCardQ_lock,
114 Mutex::_no_safepoint_check_flag);
115 _dirty_card_queue_set.shared_dirty_card_queue()->enqueue(byte);
116 }
117 }
118 }
119
120 void G1BarrierSet::invalidate(MemRegion mr) {
121 if (mr.is_empty()) {
122 return;
123 }
124 volatile jbyte* byte = _card_table->byte_for(mr.start());
125 jbyte* last_byte = _card_table->byte_for(mr.last());
126 Thread* thr = Thread::current();
127 // skip all consecutive young cards
128 for (; byte <= last_byte && *byte == G1CardTable::g1_young_card_val(); byte++);
129
130 if (byte <= last_byte) {
131 OrderAccess::storeload();
132 // Enqueue if necessary.
133 if (thr->is_Java_thread()) {
134 for (; byte <= last_byte; byte++) {
135 if (*byte == G1CardTable::g1_young_card_val()) {
136 continue;
137 }
138 if (*byte != G1CardTable::dirty_card_val()) {
139 *byte = G1CardTable::dirty_card_val();
140 G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte);
141 }
142 }
143 } else {
144 MutexLockerEx x(Shared_DirtyCardQ_lock,
145 Mutex::_no_safepoint_check_flag);
146 for (; byte <= last_byte; byte++) {
147 if (*byte == G1CardTable::g1_young_card_val()) {
148 continue;
149 }
150 if (*byte != G1CardTable::dirty_card_val()) {
151 *byte = G1CardTable::dirty_card_val();
152 _dirty_card_queue_set.shared_dirty_card_queue()->enqueue(byte);
153 }
154 }
155 }
156 }
157 }
158
159 void G1BarrierSet::on_thread_create(Thread* thread) {
160 // Create thread local data
161 G1ThreadLocalData::create(thread);
162 }
163
164 void G1BarrierSet::on_thread_destroy(Thread* thread) {
165 // Destroy thread local data
166 G1ThreadLocalData::destroy(thread);
167 }
168
169 void G1BarrierSet::on_thread_attach(JavaThread* thread) {
170 // This method initializes the SATB and dirty card queues before a
171 // JavaThread is added to the Java thread list. Right now, we don't
172 // have to do anything to the dirty card queue (it should have been
173 // activated when the thread was created), but we have to activate
174 // the SATB queue if the thread is created while a marking cycle is
175 // in progress. The activation / de-activation of the SATB queues at
176 // the beginning / end of a marking cycle is done during safepoints
177 // so we have to make sure this method is called outside one to be
178 // able to safely read the active field of the SATB queue set. Right
179 // now, it is called just before the thread is added to the Java
180 // thread list in the Threads::add() method. That method is holding
181 // the Threads_lock which ensures we are outside a safepoint. We
182 // cannot do the obvious and set the active field of the SATB queue
183 // when the thread is created given that, in some cases, safepoints
184 // might happen between the JavaThread constructor being called and the
185 // thread being added to the Java thread list (an example of this is
186 // when the structure for the DestroyJavaVM thread is created).
187 assert(!SafepointSynchronize::is_at_safepoint(), "We should not be at a safepoint");
188 assert(!G1ThreadLocalData::satb_mark_queue(thread).is_active(), "SATB queue should not be active");
189 assert(G1ThreadLocalData::satb_mark_queue(thread).is_empty(), "SATB queue should be empty");
190 assert(G1ThreadLocalData::dirty_card_queue(thread).is_active(), "Dirty card queue should be active");
191
192 // If we are creating the thread during a marking cycle, we should
193 // set the active field of the SATB queue to true.
194 if (_satb_mark_queue_set.is_active()) {
195 G1ThreadLocalData::satb_mark_queue(thread).set_active(true);
196 }
197 }
198
199 void G1BarrierSet::on_thread_detach(JavaThread* thread) {
200 // Flush any deferred card marks, SATB buffers and dirty card queue buffers
201 CardTableBarrierSet::on_thread_detach(thread);
202 G1ThreadLocalData::satb_mark_queue(thread).flush();
203 G1ThreadLocalData::dirty_card_queue(thread).flush();
204 }