1 /*
2 * Copyright (c) 2000, 2025, 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 #ifndef SHARE_GC_SHARED_CARDTABLEBARRIERSET_INLINE_HPP
26 #define SHARE_GC_SHARED_CARDTABLEBARRIERSET_INLINE_HPP
27
28 #include "gc/shared/cardTableBarrierSet.hpp"
29
30 #include "gc/shared/barrierSet.hpp"
31 #include "gc/shared/cardTable.hpp"
32 #include "oops/compressedOops.inline.hpp"
33 #include "oops/inlineKlass.inline.hpp"
34 #include "oops/objArrayOop.hpp"
35 #include "oops/oop.hpp"
36
37 template <DecoratorSet decorators, typename T>
38 inline void CardTableBarrierSet::write_ref_field_post(T* field) {
39 volatile CardValue* byte = _card_table->byte_for(field);
40 *byte = CardTable::dirty_card_val();
41 }
42
43 class Klass;
44
45 // count is number of array elements being written
46 void CardTableBarrierSet::write_ref_array(HeapWord* start, size_t count) {
47 HeapWord* end = (HeapWord*)((char*)start + (count*heapOopSize));
48 // In the case of compressed oops, start and end may potentially be misaligned;
49 // so we need to conservatively align the first downward (this is not
50 // strictly necessary for current uses, but a case of good hygiene and,
51 // if you will, aesthetics) and the second upward (this is essential for
52 // current uses) to a HeapWord boundary, so we mark all cards overlapping
53 // this write. If this evolves in the future to calling a
54 // logging barrier of narrow oop granularity, like the pre-barrier for G1
55 // (mentioned here merely by way of example), we will need to change this
56 // interface, so it is "exactly precise" (if i may be allowed the adverbial
57 // redundancy for emphasis) and does not include narrow oop slots not
58 // included in the original write interval.
59 HeapWord* aligned_start = align_down(start, HeapWordSize);
60 HeapWord* aligned_end = align_up (end, HeapWordSize);
61 // If compressed oops were not being used, these should already be aligned
62 assert(UseCompressedOops || (aligned_start == start && aligned_end == end),
63 "Expected heap word alignment of start and end");
64 write_region(MemRegion(aligned_start, aligned_end));
65 }
66
67 template <DecoratorSet decorators, typename BarrierSetT>
68 template <typename T>
69 inline void CardTableBarrierSet::AccessBarrier<decorators, BarrierSetT>::
70 oop_store_in_heap(T* addr, oop value) {
71 BarrierSetT *bs = barrier_set_cast<BarrierSetT>(barrier_set());
72 bs->template write_ref_field_pre<decorators>(addr);
73 Raw::oop_store(addr, value);
74 bs->template write_ref_field_post<decorators>(addr);
75 }
76
77 template <DecoratorSet decorators, typename BarrierSetT>
78 template <typename T>
79 inline oop CardTableBarrierSet::AccessBarrier<decorators, BarrierSetT>::
80 oop_atomic_cmpxchg_in_heap(T* addr, oop compare_value, oop new_value) {
81 BarrierSetT *bs = barrier_set_cast<BarrierSetT>(barrier_set());
82 bs->template write_ref_field_pre<decorators>(addr);
83 oop result = Raw::oop_atomic_cmpxchg(addr, compare_value, new_value);
84 if (result == compare_value) {
85 bs->template write_ref_field_post<decorators>(addr);
86 }
87 return result;
88 }
89
90 template <DecoratorSet decorators, typename BarrierSetT>
91 template <typename T>
92 inline oop CardTableBarrierSet::AccessBarrier<decorators, BarrierSetT>::
93 oop_atomic_xchg_in_heap(T* addr, oop new_value) {
94 BarrierSetT *bs = barrier_set_cast<BarrierSetT>(barrier_set());
95 bs->template write_ref_field_pre<decorators>(addr);
96 oop result = Raw::oop_atomic_xchg(addr, new_value);
97 bs->template write_ref_field_post<decorators>(addr);
98 return result;
99 }
100
101 template <DecoratorSet decorators, typename BarrierSetT>
102 template <typename T>
103 inline void CardTableBarrierSet::AccessBarrier<decorators, BarrierSetT>::
104 oop_arraycopy_partial_barrier(BarrierSetT *bs, T* dst_raw, T* p) {
105 const size_t pd = pointer_delta(p, dst_raw, (size_t)heapOopSize);
106 // pointer delta is scaled to number of elements (length field in
107 // objArrayOop) which we assume is 32 bit.
108 assert(pd == (size_t)(int)pd, "length field overflow");
109 bs->write_ref_array((HeapWord*)dst_raw, pd);
110 }
111
112 template <DecoratorSet decorators, typename BarrierSetT>
113 template <typename T>
114 inline void CardTableBarrierSet::AccessBarrier<decorators, BarrierSetT>::
115 oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
116 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
117 size_t length) {
118 BarrierSetT *bs = barrier_set_cast<BarrierSetT>(barrier_set());
119
120 src_raw = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw);
121 dst_raw = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw);
122
123 if ((!HasDecorator<decorators, ARRAYCOPY_CHECKCAST>::value) &&
124 (!HasDecorator<decorators, ARRAYCOPY_NOTNULL>::value)) {
125 // Optimized covariant case
126 bs->write_ref_array_pre(dst_raw, length,
127 HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value);
128 Raw::oop_arraycopy(nullptr, 0, src_raw, nullptr, 0, dst_raw, length);
129 bs->write_ref_array((HeapWord*)dst_raw, length);
130 } else {
131 assert(dst_obj != nullptr, "better have an actual oop");
132 Klass* bound = objArrayOop(dst_obj)->element_klass();
133 T* from = const_cast<T*>(src_raw);
134 T* end = from + length;
135 for (T* p = dst_raw; from < end; from++, p++) {
136 T element = *from;
137 // Apply any required checks
138 if (HasDecorator<decorators, ARRAYCOPY_NOTNULL>::value && CompressedOops::is_null(element)) {
139 oop_arraycopy_partial_barrier(bs, dst_raw, p);
140 throw_array_null_pointer_store_exception(src_obj, dst_obj, JavaThread::current());
141 return;
142 }
143 if (HasDecorator<decorators, ARRAYCOPY_CHECKCAST>::value &&
144 (!oopDesc::is_instanceof_or_null(CompressedOops::decode(element), bound))) {
145 oop_arraycopy_partial_barrier(bs, dst_raw, p);
146 throw_array_store_exception(src_obj, dst_obj, JavaThread::current());
147 return;
148 }
149 // write
150 bs->template write_ref_field_pre<decorators>(p);
151 *p = element;
152 }
153 bs->write_ref_array((HeapWord*)dst_raw, length);
154 }
155 }
156
157 template <DecoratorSet decorators, typename BarrierSetT>
158 inline void CardTableBarrierSet::AccessBarrier<decorators, BarrierSetT>::
159 clone_in_heap(oop src, oop dst, size_t size) {
160 Raw::clone(src, dst, size);
161 BarrierSetT *bs = barrier_set_cast<BarrierSetT>(barrier_set());
162 bs->write_region(MemRegion((HeapWord*)(void*)dst, size));
163 }
164
165 template <DecoratorSet decorators, typename BarrierSetT>
166 inline void CardTableBarrierSet::AccessBarrier<decorators, BarrierSetT>::
167 value_copy_in_heap(void* src, void* dst, InlineKlass* md, LayoutKind lk) {
168 if (!md->contains_oops()) {
169 // If we do not have oops in the flat array, we can just do a raw copy.
170 Raw::value_copy(src, dst, md, lk);
171 } else {
172 BarrierSetT* bs = barrier_set_cast<BarrierSetT>(BarrierSet::barrier_set());
173 // src/dst aren't oops, need offset to adjust oop map offset
174 const address dst_oop_addr_offset = ((address) dst) - md->payload_offset();
175 typedef typename ValueOopType<decorators>::type OopType;
176
177 // Pre-barriers...
178 OopMapBlock* map = md->start_of_nonstatic_oop_maps();
179 OopMapBlock* const end = map + md->nonstatic_oop_map_count();
180 bool is_uninitialized = HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value;
181 while (map != end) {
182 address doop_address = dst_oop_addr_offset + map->offset();
183 // The pre-barrier only impacts G1, which will emit a barrier if the destination is
184 // initialized. Note that we should not emit a barrier if the destination is uninitialized,
185 // as doing so will fill the SATB queue with garbage data.
186 bs->write_ref_array_pre((OopType*) doop_address, map->count(), is_uninitialized);
187 map++;
188 }
189
190 Raw::value_copy(src, dst, md, lk);
191
192 // Post-barriers...
193 map = md->start_of_nonstatic_oop_maps();
194 while (map != end) {
195 address doop_address = dst_oop_addr_offset + map->offset();
196 // The post-barrier needs to be called for initialized and uninitialized destinations.
197 bs->write_ref_array((HeapWord*) doop_address, map->count());
198 map++;
199 }
200 }
201 }
202
203 #endif // SHARE_GC_SHARED_CARDTABLEBARRIERSET_INLINE_HPP