1 /*
2 * Copyright (c) 2013, 2022, Red Hat, Inc. All rights reserved.
3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "gc/shared/barrierSetNMethod.hpp"
28 #include "gc/shenandoah/shenandoahBarrierSetClone.inline.hpp"
29 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
30 #include "gc/shenandoah/shenandoahBarrierSetNMethod.hpp"
31 #include "gc/shenandoah/shenandoahBarrierSetStackChunk.hpp"
32 #include "gc/shenandoah/shenandoahClosures.inline.hpp"
33 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
34 #include "gc/shenandoah/shenandoahScanRemembered.inline.hpp"
35 #include "gc/shenandoah/shenandoahStackWatermark.hpp"
36 #ifdef COMPILER1
37 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
38 #endif
39 #ifdef COMPILER2
40 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
41 #endif
42
43 class ShenandoahBarrierSetC1;
44 class ShenandoahBarrierSetC2;
45
46 ShenandoahBarrierSet::ShenandoahBarrierSet(ShenandoahHeap* heap, MemRegion heap_region) :
47 BarrierSet(make_barrier_set_assembler<ShenandoahBarrierSetAssembler>(),
48 make_barrier_set_c1<ShenandoahBarrierSetC1>(),
49 make_barrier_set_c2<ShenandoahBarrierSetC2>(),
50 new ShenandoahBarrierSetNMethod(heap),
51 new ShenandoahBarrierSetStackChunk(),
52 BarrierSet::FakeRtti(BarrierSet::ShenandoahBarrierSet)),
53 _heap(heap),
54 _satb_mark_queue_buffer_allocator("SATB Buffer Allocator", ShenandoahSATBBufferSize),
55 _satb_mark_queue_set(&_satb_mark_queue_buffer_allocator)
56 {
57 if (ShenandoahCardBarrier) {
58 _card_table = new ShenandoahCardTable(heap_region);
59 _card_table->initialize();
60 }
61 }
62
63 ShenandoahBarrierSetAssembler* ShenandoahBarrierSet::assembler() {
64 BarrierSetAssembler* const bsa = BarrierSet::barrier_set()->barrier_set_assembler();
65 return reinterpret_cast<ShenandoahBarrierSetAssembler*>(bsa);
66 }
67
68 void ShenandoahBarrierSet::print_on(outputStream* st) const {
69 st->print("ShenandoahBarrierSet");
70 }
71
72 bool ShenandoahBarrierSet::need_load_reference_barrier(DecoratorSet decorators, BasicType type) {
73 if (!ShenandoahLoadRefBarrier) return false;
74 // Only needed for references
75 return is_reference_type(type);
76 }
77
78 bool ShenandoahBarrierSet::need_keep_alive_barrier(DecoratorSet decorators, BasicType type) {
79 if (!ShenandoahSATBBarrier) return false;
80 // Only needed for references
81 if (!is_reference_type(type)) return false;
82
83 bool keep_alive = (decorators & AS_NO_KEEPALIVE) == 0;
84 bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0;
85 bool on_weak_ref = (decorators & (ON_WEAK_OOP_REF | ON_PHANTOM_OOP_REF)) != 0;
86 return (on_weak_ref || unknown) && keep_alive;
87 }
88
89 void ShenandoahBarrierSet::on_thread_create(Thread* thread) {
90 // Create thread local data
91 ShenandoahThreadLocalData::create(thread);
92 }
93
94 void ShenandoahBarrierSet::on_thread_destroy(Thread* thread) {
95 // Destroy thread local data
96 ShenandoahThreadLocalData::destroy(thread);
97 }
98
99 void ShenandoahBarrierSet::on_thread_attach(Thread *thread) {
100 assert(!thread->is_Java_thread() || !SafepointSynchronize::is_at_safepoint(),
101 "We should not be at a safepoint");
102 SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
103 assert(!queue.is_active(), "SATB queue should not be active");
104 assert(queue.buffer() == nullptr, "SATB queue should not have a buffer");
105 assert(queue.index() == 0, "SATB queue index should be zero");
106 queue.set_active(_satb_mark_queue_set.is_active());
107 if (thread->is_Java_thread()) {
108 ShenandoahThreadLocalData::set_gc_state(thread, _heap->gc_state());
109 ShenandoahThreadLocalData::initialize_gclab(thread);
110
111 BarrierSetNMethod* bs_nm = barrier_set_nmethod();
112 if (bs_nm != nullptr) {
113 thread->set_nmethod_disarmed_guard_value(bs_nm->disarmed_guard_value());
114 }
115
116 if (ShenandoahStackWatermarkBarrier) {
117 JavaThread* const jt = JavaThread::cast(thread);
118 StackWatermark* const watermark = new ShenandoahStackWatermark(jt);
119 StackWatermarkSet::add_watermark(jt, watermark);
120 }
121 }
122 }
123
124 void ShenandoahBarrierSet::on_thread_detach(Thread *thread) {
125 SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
126 _satb_mark_queue_set.flush_queue(queue);
127 if (thread->is_Java_thread()) {
128 PLAB* gclab = ShenandoahThreadLocalData::gclab(thread);
129 if (gclab != nullptr) {
130 gclab->retire();
131 }
132
133 if (ShenandoahCardBarrier) {
134 PLAB* plab = ShenandoahThreadLocalData::plab(thread);
135 // retire_plab may register the remnant filler object with the remembered set scanner without a lock.
136 // This is safe because it is assured that each PLAB is a whole-number multiple of card-mark memory size and each
137 // PLAB is aligned with the start of each card's memory range.
138 if (plab != nullptr) {
139 ShenandoahGenerationalHeap::heap()->retire_plab(plab);
140 }
141 }
142
143 // SATB protocol requires to keep alive reachable oops from roots at the beginning of GC
144 if (ShenandoahStackWatermarkBarrier) {
145 if (_heap->is_concurrent_mark_in_progress()) {
146 ShenandoahKeepAliveClosure oops;
147 StackWatermarkSet::finish_processing(JavaThread::cast(thread), &oops, StackWatermarkKind::gc);
148 } else if (_heap->is_concurrent_weak_root_in_progress() && _heap->is_evacuation_in_progress()) {
149 ShenandoahContextEvacuateUpdateRootsClosure oops;
150 StackWatermarkSet::finish_processing(JavaThread::cast(thread), &oops, StackWatermarkKind::gc);
151 }
152 }
153 }
154 }
155
156 void ShenandoahBarrierSet::clone_barrier_runtime(oop src) {
157 if (_heap->has_forwarded_objects() || (ShenandoahIUBarrier && _heap->is_concurrent_mark_in_progress())) {
158 clone_barrier(src);
159 }
160 }
161
162 void ShenandoahBarrierSet::write_ref_array(HeapWord* start, size_t count) {
163 assert(ShenandoahCardBarrier, "Did you mean to enable ShenandoahCardBarrier?");
164
165 HeapWord* end = (HeapWord*)((char*) start + (count * heapOopSize));
166 // In the case of compressed oops, start and end may potentially be misaligned;
167 // so we need to conservatively align the first downward (this is not
168 // strictly necessary for current uses, but a case of good hygiene and,
169 // if you will, aesthetics) and the second upward (this is essential for
170 // current uses) to a HeapWord boundary, so we mark all cards overlapping
171 // this write.
172 HeapWord* aligned_start = align_down(start, HeapWordSize);
173 HeapWord* aligned_end = align_up (end, HeapWordSize);
174 // If compressed oops were not being used, these should already be aligned
175 assert(UseCompressedOops || (aligned_start == start && aligned_end == end),
176 "Expected heap word alignment of start and end");
177 _heap->old_generation()->card_scan()->mark_range_as_dirty(aligned_start, (aligned_end - aligned_start));
178 }
179