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/shenandoahCardTable.hpp"
33 #include "gc/shenandoah/shenandoahClosures.inline.hpp"
34 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
35 #include "gc/shenandoah/shenandoahScanRemembered.inline.hpp"
36 #include "gc/shenandoah/shenandoahStackWatermark.hpp"
37 #ifdef COMPILER1
38 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
39 #endif
40 #ifdef COMPILER2
41 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
42 #endif
43
44 class ShenandoahBarrierSetC1;
45 class ShenandoahBarrierSetC2;
46
47 ShenandoahBarrierSet::ShenandoahBarrierSet(ShenandoahHeap* heap, MemRegion heap_region) :
48 BarrierSet(make_barrier_set_assembler<ShenandoahBarrierSetAssembler>(),
49 make_barrier_set_c1<ShenandoahBarrierSetC1>(),
50 make_barrier_set_c2<ShenandoahBarrierSetC2>(),
51 new ShenandoahBarrierSetNMethod(heap),
52 new ShenandoahBarrierSetStackChunk(),
53 BarrierSet::FakeRtti(BarrierSet::ShenandoahBarrierSet)),
54 _heap(heap),
55 _card_table(nullptr),
56 _satb_mark_queue_buffer_allocator("SATB Buffer Allocator", ShenandoahSATBBufferSize),
57 _satb_mark_queue_set(&_satb_mark_queue_buffer_allocator)
58 {
59 if (ShenandoahCardBarrier) {
60 _card_table = new ShenandoahCardTable(heap_region);
61 _card_table->initialize();
62 }
63 }
64
65 ShenandoahBarrierSetAssembler* ShenandoahBarrierSet::assembler() {
66 BarrierSetAssembler* const bsa = BarrierSet::barrier_set()->barrier_set_assembler();
67 return reinterpret_cast<ShenandoahBarrierSetAssembler*>(bsa);
68 }
69
70 void ShenandoahBarrierSet::print_on(outputStream* st) const {
71 st->print("ShenandoahBarrierSet");
72 }
73
74 bool ShenandoahBarrierSet::need_load_reference_barrier(DecoratorSet decorators, BasicType type) {
75 if (!ShenandoahLoadRefBarrier) return false;
76 // Only needed for references
77 return is_reference_type(type);
78 }
79
80 bool ShenandoahBarrierSet::need_keep_alive_barrier(DecoratorSet decorators, BasicType type) {
81 if (!ShenandoahSATBBarrier) return false;
82 // Only needed for references
83 if (!is_reference_type(type)) return false;
84
85 bool keep_alive = (decorators & AS_NO_KEEPALIVE) == 0;
86 bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0;
87 bool on_weak_ref = (decorators & (ON_WEAK_OOP_REF | ON_PHANTOM_OOP_REF)) != 0;
88 return (on_weak_ref || unknown) && keep_alive;
89 }
90
91 void ShenandoahBarrierSet::on_thread_create(Thread* thread) {
92 // Create thread local data
93 ShenandoahThreadLocalData::create(thread);
94 }
95
96 void ShenandoahBarrierSet::on_thread_destroy(Thread* thread) {
97 // Destroy thread local data
98 ShenandoahThreadLocalData::destroy(thread);
99 }
100
101 void ShenandoahBarrierSet::on_thread_attach(Thread *thread) {
102 assert(!thread->is_Java_thread() || !SafepointSynchronize::is_at_safepoint(),
103 "We should not be at a safepoint");
104 SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
105 assert(!queue.is_active(), "SATB queue should not be active");
106 assert(queue.buffer() == nullptr, "SATB queue should not have a buffer");
107 assert(queue.index() == 0, "SATB queue index should be zero");
108 queue.set_active(_satb_mark_queue_set.is_active());
109 if (thread->is_Java_thread()) {
110 ShenandoahThreadLocalData::set_gc_state(thread, _heap->gc_state());
111 ShenandoahThreadLocalData::initialize_gclab(thread);
112
113 BarrierSetNMethod* bs_nm = barrier_set_nmethod();
114 if (bs_nm != nullptr) {
115 thread->set_nmethod_disarmed_guard_value(bs_nm->disarmed_guard_value());
116 }
117
118 if (ShenandoahStackWatermarkBarrier) {
119 JavaThread* const jt = JavaThread::cast(thread);
120 StackWatermark* const watermark = new ShenandoahStackWatermark(jt);
121 StackWatermarkSet::add_watermark(jt, watermark);
122 }
123 }
124 }
125
126 void ShenandoahBarrierSet::on_thread_detach(Thread *thread) {
127 SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
128 _satb_mark_queue_set.flush_queue(queue);
129 if (thread->is_Java_thread()) {
130 PLAB* gclab = ShenandoahThreadLocalData::gclab(thread);
131 if (gclab != nullptr) {
132 gclab->retire();
133 }
134
135 PLAB* plab = ShenandoahThreadLocalData::plab(thread);
136 if (plab != nullptr) {
137 // This will assert if plab is not null in non-generational mode
138 ShenandoahGenerationalHeap::heap()->retire_plab(plab);
139 }
140
141 // SATB protocol requires to keep alive reachable oops from roots at the beginning of GC
142 if (ShenandoahStackWatermarkBarrier) {
143 if (_heap->is_concurrent_mark_in_progress()) {
144 ShenandoahKeepAliveClosure oops;
145 StackWatermarkSet::finish_processing(JavaThread::cast(thread), &oops, StackWatermarkKind::gc);
146 } else if (_heap->is_concurrent_weak_root_in_progress() && _heap->is_evacuation_in_progress()) {
147 ShenandoahContextEvacuateUpdateRootsClosure oops;
148 StackWatermarkSet::finish_processing(JavaThread::cast(thread), &oops, StackWatermarkKind::gc);
149 }
150 }
151 }
152 }
153
154 void ShenandoahBarrierSet::clone_barrier_runtime(oop src) {
155 if (_heap->has_forwarded_objects()) {
156 clone_barrier(src);
157 }
158 }
159
160 void ShenandoahBarrierSet::write_ref_array(HeapWord* start, size_t count) {
161 assert(ShenandoahCardBarrier, "Should have been checked by caller");
162
163 HeapWord* end = (HeapWord*)((char*) start + (count * heapOopSize));
164 // In the case of compressed oops, start and end may potentially be misaligned;
165 // so we need to conservatively align the first downward (this is not
166 // strictly necessary for current uses, but a case of good hygiene and,
167 // if you will, aesthetics) and the second upward (this is essential for
168 // current uses) to a HeapWord boundary, so we mark all cards overlapping
169 // this write.
170 HeapWord* aligned_start = align_down(start, HeapWordSize);
171 HeapWord* aligned_end = align_up (end, HeapWordSize);
172 // If compressed oops were not being used, these should already be aligned
173 assert(UseCompressedOops || (aligned_start == start && aligned_end == end),
174 "Expected heap word alignment of start and end");
175 _heap->old_generation()->card_scan()->mark_range_as_dirty(aligned_start, (aligned_end - aligned_start));
176 }
177