1 /*
2 * Copyright (c) 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 #include "cds/aotClassLinker.hpp"
26 #include "cds/aotArtifactFinder.hpp"
27 #include "cds/aotClassInitializer.hpp"
28 #include "cds/dumpTimeClassInfo.inline.hpp"
29 #include "cds/heapShared.hpp"
30 #include "classfile/systemDictionaryShared.hpp"
31 #include "logging/log.hpp"
32 #include "memory/metaspaceClosure.hpp"
33 #include "oops/instanceKlass.hpp"
34 #include "oops/objArrayKlass.hpp"
35 #include "utilities/resourceHash.hpp"
36
37 // All the classes that should be included in the AOT cache (in at least the "allocated" state)
38 static GrowableArrayCHeap<Klass*, mtClassShared>* _all_cached_classes = nullptr;
39
40 // This is a stack that tracks all the AOT-inited classes that are waiting to be passed
41 // to HeapShared::copy_and_rescan_aot_inited_mirror().
42 static GrowableArrayCHeap<InstanceKlass*, mtClassShared>* _pending_aot_inited_classes = nullptr;
43
44 static const int TABLE_SIZE = 15889; // prime number
45 using ClassesTable = ResourceHashtable<Klass*, bool, TABLE_SIZE, AnyObj::C_HEAP, mtClassShared>;
46 static ClassesTable* _seen_classes; // all classes that have been seen by AOTArtifactFinder
47 static ClassesTable* _aot_inited_classes; // all classes that need to be AOT-initialized.
48
49 void AOTArtifactFinder::initialize() {
50 _all_cached_classes = new GrowableArrayCHeap<Klass*, mtClassShared>();
51 _pending_aot_inited_classes = new GrowableArrayCHeap<InstanceKlass*, mtClassShared>();
52 _seen_classes = new (mtClass)ClassesTable();
53 _aot_inited_classes = new (mtClass)ClassesTable();
54 }
55
56 void AOTArtifactFinder::dispose() {
57 delete _all_cached_classes;
58 delete _seen_classes;
59 delete _aot_inited_classes;
60 delete _pending_aot_inited_classes;
61 _all_cached_classes = nullptr;
62 _seen_classes = nullptr;
63 _aot_inited_classes = nullptr;
64 _pending_aot_inited_classes = nullptr;
65 }
66
67 // Find all Klasses and oops that should be included in the AOT cache. See aotArtifactFinder.hpp
68 void AOTArtifactFinder::find_artifacts() {
69 // Some classes might have been marked as excluded as a side effect of running
70 // AOTConstantPoolResolver. Make sure we check all the remaining ones.
71 //
72 // Note, if a class is not excluded, it does NOT mean it will be automatically included
73 // into the AOT cache -- that will be decided by the code below.
74 SystemDictionaryShared::finish_exclusion_checks();
75
76 start_scanning_for_oops();
77
78 // Add the primitive array classes
79 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
80 BasicType bt = (BasicType)i;
81 if (is_java_primitive(bt)) {
82 add_cached_type_array_class(Universe::typeArrayKlass(bt));
83 }
84 }
85
86 #if INCLUDE_CDS_JAVA_HEAP
87 // Add the mirrors that aren't associated with a Klass
88 // - primitive mirrors (E.g., "int.class" in Java code)
89 // - mirror of fillerArrayKlass
90 if (CDSConfig::is_dumping_heap()) {
91 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
92 BasicType bt = (BasicType)i;
93 if (!is_reference_type(bt)) {
94 oop orig_mirror = Universe::java_mirror(bt);
95 oop scratch_mirror = HeapShared::scratch_java_mirror(bt);
96 HeapShared::scan_java_mirror(orig_mirror);
97 log_trace(cds, heap, mirror)(
98 "Archived %s mirror object from " PTR_FORMAT,
99 type2name(bt), p2i(scratch_mirror));
100 Universe::set_archived_basic_type_mirror_index(bt, HeapShared::append_root(scratch_mirror));
101 }
102 }
103
104 // Universe::fillerArrayKlass() isn't in the class hierarchy, so handle it specially.
105 HeapShared::scan_java_mirror(Universe::fillerArrayKlass()->java_mirror());
106 }
107 #endif
108
109 // Add all the InstanceKlasses (and their array classes) that are always included.
110 SystemDictionaryShared::dumptime_table()->iterate_all_live_classes([&] (InstanceKlass* ik, DumpTimeClassInfo& info) {
111 if (!info.is_excluded()) {
112 bool add = false;
113 if (!ik->is_hidden()) {
114 // All non-hidden classes are always included into the AOT cache
115 add = true;
116 } else {
117 if (!CDSConfig::is_dumping_invokedynamic()) {
118 // Legacy support of lambda proxies -- these are always included into the AOT cache
119 if (SystemDictionaryShared::is_registered_lambda_proxy_class(ik)) {
120 add = true;
121 }
122 } else {
123 assert(!SystemDictionaryShared::is_registered_lambda_proxy_class(ik),
124 "registered lambda proxies are only for legacy lambda proxy support");
125 }
126 }
127
128 if (add) {
129 add_cached_instance_class(ik);
130 if (AOTClassInitializer::can_archive_initialized_mirror(ik)) {
131 add_aot_inited_class(ik);
132 }
133 }
134 }
135 });
136
137 #if INCLUDE_CDS_JAVA_HEAP
138 // Keep scanning until we discover no more class that need to be AOT-initialized.
139 if (CDSConfig::is_initing_classes_at_dump_time()) {
140 while (_pending_aot_inited_classes->length() > 0) {
141 InstanceKlass* ik = _pending_aot_inited_classes->pop();
142 HeapShared::copy_and_rescan_aot_inited_mirror(ik);
143 }
144 }
145 #endif
146
147 // Exclude all the (hidden) classes that have not been discovered by the code above.
148 SystemDictionaryShared::dumptime_table()->iterate_all_live_classes([&] (InstanceKlass* k, DumpTimeClassInfo& info) {
149 if (!info.is_excluded() && _seen_classes->get(k) == nullptr) {
150 info.set_excluded();
151 assert(k->is_hidden(), "must be");
152 if (log_is_enabled(Info, cds)) {
153 ResourceMark rm;
154 log_info(cds)("Skipping %s: Hidden class", k->name()->as_C_string());
155 }
156 }
157 });
158
159 end_scanning_for_oops();
160 }
161
162 void AOTArtifactFinder::start_scanning_for_oops() {
163 #if INCLUDE_CDS_JAVA_HEAP
164 if (CDSConfig::is_dumping_heap()) {
165 HeapShared::start_scanning_for_oops();
166 }
167 #endif
168 }
169
170 void AOTArtifactFinder::end_scanning_for_oops() {
171 #if INCLUDE_CDS_JAVA_HEAP
172 if (CDSConfig::is_dumping_heap()) {
173 HeapShared::end_scanning_for_oops();
174 }
175 #endif
176 }
177
178 void AOTArtifactFinder::add_aot_inited_class(InstanceKlass* ik) {
179 if (CDSConfig::is_initing_classes_at_dump_time()) {
180 assert(ik->is_initialized(), "must be");
181 add_cached_instance_class(ik);
182
183 bool created;
184 _aot_inited_classes->put_if_absent(ik, &created);
185 if (created) {
186 _pending_aot_inited_classes->push(ik);
187
188 InstanceKlass* s = ik->java_super();
189 if (s != nullptr) {
190 add_aot_inited_class(s);
191 }
192
193 Array<InstanceKlass*>* interfaces = ik->local_interfaces();
194 int len = interfaces->length();
195 for (int i = 0; i < len; i++) {
196 InstanceKlass* intf = interfaces->at(i);
197 if (intf->is_initialized()) {
198 add_aot_inited_class(intf);
199 }
200 }
201 }
202 }
203 }
204
205 void AOTArtifactFinder::add_cached_instance_class(InstanceKlass* ik) {
206 bool created;
207 _seen_classes->put_if_absent(ik, &created);
208 if (created) {
209 _all_cached_classes->append(ik);
210 scan_oops_in_instance_class(ik);
211 if (ik->is_hidden() && CDSConfig::is_initing_classes_at_dump_time()) {
212 bool succeed = AOTClassLinker::try_add_candidate(ik);
213 guarantee(succeed, "All cached hidden classes must be aot-linkable");
214 add_aot_inited_class(ik);
215 }
216 }
217 }
218
219 void AOTArtifactFinder::add_cached_type_array_class(TypeArrayKlass* tak) {
220 bool created;
221 _seen_classes->put_if_absent(tak, &created);
222 if (created) {
223 _all_cached_classes->append(tak);
224 scan_oops_in_array_class(tak);
225 }
226 }
227
228 void AOTArtifactFinder::add_cached_class(Klass* k) {
229 if (k->is_typeArray_klass()) {
230 add_cached_type_array_class(TypeArrayKlass::cast(k));
231 } else if (k->is_objArray_klass()) {
232 add_cached_class(ObjArrayKlass::cast(k)->element_klass());
233 } else {
234 add_cached_instance_class(InstanceKlass::cast(k));
235 }
236 }
237
238 void AOTArtifactFinder::scan_oops_in_instance_class(InstanceKlass* ik) {
239 #if INCLUDE_CDS_JAVA_HEAP
240 if (CDSConfig::is_dumping_heap()) {
241 HeapShared::scan_java_class(ik);
242 scan_oops_in_array_class(ik->array_klasses());
243 }
244 #endif
245 }
246
247 void AOTArtifactFinder::scan_oops_in_array_class(ArrayKlass* ak) {
248 #if INCLUDE_CDS_JAVA_HEAP
249 if (CDSConfig::is_dumping_heap()) {
250 while (ak != nullptr) {
251 HeapShared::scan_java_class(ak);
252 ak = ak->array_klass_or_null();
253 }
254 }
255 #endif
256 }
257
258 void AOTArtifactFinder::all_cached_classes_do(MetaspaceClosure* it) {
259 for (int i = 0; i < _all_cached_classes->length(); i++) {
260 it->push(_all_cached_classes->adr_at(i));
261 }
262 }