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 "cds/lambdaProxyClassDictionary.hpp"
31 #include "classfile/systemDictionaryShared.hpp"
32 #include "logging/log.hpp"
33 #include "memory/metaspaceClosure.hpp"
34 #include "oops/instanceKlass.hpp"
35 #include "oops/objArrayKlass.hpp"
36 #include "oops/trainingData.hpp"
37 #include "utilities/resourceHash.hpp"
38
39 // All the classes that should be included in the AOT cache (in at least the "allocated" state)
40 static GrowableArrayCHeap<Klass*, mtClassShared>* _all_cached_classes = nullptr;
41
42 // This is a stack that tracks all the AOT-inited classes that are waiting to be passed
43 // to HeapShared::copy_and_rescan_aot_inited_mirror().
44 static GrowableArrayCHeap<InstanceKlass*, mtClassShared>* _pending_aot_inited_classes = nullptr;
45
46 static const int TABLE_SIZE = 15889; // prime number
47 using ClassesTable = ResourceHashtable<Klass*, bool, TABLE_SIZE, AnyObj::C_HEAP, mtClassShared>;
48 static ClassesTable* _seen_classes; // all classes that have been seen by AOTArtifactFinder
49 static ClassesTable* _aot_inited_classes; // all classes that need to be AOT-initialized.
50
51 void AOTArtifactFinder::initialize() {
52 _all_cached_classes = new GrowableArrayCHeap<Klass*, mtClassShared>();
53 _pending_aot_inited_classes = new GrowableArrayCHeap<InstanceKlass*, mtClassShared>();
54 _seen_classes = new (mtClass)ClassesTable();
55 _aot_inited_classes = new (mtClass)ClassesTable();
56 }
57
58 void AOTArtifactFinder::dispose() {
59 delete _all_cached_classes;
60 delete _seen_classes;
61 delete _aot_inited_classes;
62 delete _pending_aot_inited_classes;
63 _all_cached_classes = nullptr;
64 _seen_classes = nullptr;
65 _aot_inited_classes = nullptr;
66 _pending_aot_inited_classes = nullptr;
67 }
68
69 // Find all Klasses and oops that should be included in the AOT cache. See aotArtifactFinder.hpp
70 void AOTArtifactFinder::find_artifacts() {
71 // Some classes might have been marked as excluded as a side effect of running
72 // AOTConstantPoolResolver. Make sure we check all the remaining ones.
73 //
74 // Note, if a class is not excluded, it does NOT mean it will be automatically included
75 // into the AOT cache -- that will be decided by the code below.
76 SystemDictionaryShared::finish_exclusion_checks();
77
78 start_scanning_for_oops();
79
80 // Add the primitive array classes
81 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
82 BasicType bt = (BasicType)i;
83 if (is_java_primitive(bt)) {
84 add_cached_type_array_class(Universe::typeArrayKlass(bt));
85 }
86 }
87
88 #if INCLUDE_CDS_JAVA_HEAP
89 // Add the mirrors that aren't associated with a Klass
90 // - primitive mirrors (E.g., "int.class" in Java code)
91 // - mirror of fillerArrayKlass
92 if (CDSConfig::is_dumping_heap()) {
93 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
94 BasicType bt = (BasicType)i;
95 if (!is_reference_type(bt)) {
96 oop orig_mirror = Universe::java_mirror(bt);
97 oop scratch_mirror = HeapShared::scratch_java_mirror(bt);
98 HeapShared::scan_java_mirror(orig_mirror);
99 log_trace(cds, heap, mirror)(
100 "Archived %s mirror object from " PTR_FORMAT,
101 type2name(bt), p2i(scratch_mirror));
102 Universe::set_archived_basic_type_mirror_index(bt, HeapShared::append_root(scratch_mirror));
103 }
104 }
105
106 // Universe::fillerArrayKlass() isn't in the class hierarchy, so handle it specially.
107 HeapShared::scan_java_mirror(Universe::fillerArrayKlass()->java_mirror());
108 }
109 #endif
110
111 // Add all the InstanceKlasses (and their array classes) that are always included.
112 SystemDictionaryShared::dumptime_table()->iterate_all_live_classes([&] (InstanceKlass* ik, DumpTimeClassInfo& info) {
113 // Skip "AOT tooling classes" in this block. They will be included in the AOT cache only if
114 // - One of their subtypes is included
115 // - One of their instances is found by HeapShared.
116 if (!info.is_excluded() && !info.is_aot_tooling_class()) {
117 bool add = false;
118 if (!ik->is_hidden()) {
119 // All non-hidden classes are always included into the AOT cache
120 add = true;
121 } else {
122 if (CDSConfig::is_dumping_lambdas_in_legacy_mode()) {
123 // Legacy support of lambda proxies -- these are always included into the AOT cache
124 if (LambdaProxyClassDictionary::is_registered_lambda_proxy_class(ik)) {
125 add = true;
126 }
127 } else {
128 assert(!LambdaProxyClassDictionary::is_registered_lambda_proxy_class(ik),
129 "registered lambda proxies are only for legacy lambda proxy support");
130 }
131 }
132
133 if (add) {
134 add_cached_instance_class(ik);
135 if (AOTClassInitializer::can_archive_initialized_mirror(ik)) {
136 add_aot_inited_class(ik);
137 }
138 }
139 }
140 });
141
142 #if INCLUDE_CDS_JAVA_HEAP
143 // Keep scanning until we discover no more class that need to be AOT-initialized.
144 if (CDSConfig::is_initing_classes_at_dump_time()) {
145 while (_pending_aot_inited_classes->length() > 0) {
146 InstanceKlass* ik = _pending_aot_inited_classes->pop();
147 HeapShared::copy_and_rescan_aot_inited_mirror(ik);
148 }
149 }
150 #endif
151
152 // Exclude all the (hidden) classes that have not been discovered by the code above.
153 SystemDictionaryShared::dumptime_table()->iterate_all_live_classes([&] (InstanceKlass* k, DumpTimeClassInfo& info) {
154 if (!info.is_excluded() && _seen_classes->get(k) == nullptr) {
155 info.set_excluded();
156 info.set_has_checked_exclusion();
157 if (log_is_enabled(Debug, cds)) {
158 ResourceMark rm;
159 log_debug(cds)("Skipping %s: %s class", k->name()->as_C_string(),
160 k->is_hidden() ? "Unreferenced hidden" : "AOT tooling");
161 }
162 }
163 });
164
165 end_scanning_for_oops();
166
167 TrainingData::cleanup_training_data();
168 }
169
170 void AOTArtifactFinder::start_scanning_for_oops() {
171 #if INCLUDE_CDS_JAVA_HEAP
172 if (CDSConfig::is_dumping_heap()) {
173 HeapShared::start_scanning_for_oops();
174 }
175 #endif
176 }
177
178 void AOTArtifactFinder::end_scanning_for_oops() {
179 #if INCLUDE_CDS_JAVA_HEAP
180 if (CDSConfig::is_dumping_heap()) {
181 HeapShared::end_scanning_for_oops();
182 }
183 #endif
184 }
185
186 void AOTArtifactFinder::add_aot_inited_class(InstanceKlass* ik) {
187 if (CDSConfig::is_initing_classes_at_dump_time()) {
188 assert(ik->is_initialized(), "must be");
189 add_cached_instance_class(ik);
190
191 bool created;
192 _aot_inited_classes->put_if_absent(ik, &created);
193 if (created) {
194 _pending_aot_inited_classes->push(ik);
195
196 InstanceKlass* s = ik->java_super();
197 if (s != nullptr) {
198 add_aot_inited_class(s);
199 }
200
201 Array<InstanceKlass*>* interfaces = ik->local_interfaces();
202 int len = interfaces->length();
203 for (int i = 0; i < len; i++) {
204 InstanceKlass* intf = interfaces->at(i);
205 if (intf->is_initialized()) {
206 add_aot_inited_class(intf);
207 }
208 }
209 }
210 }
211 }
212
213 void AOTArtifactFinder::add_cached_instance_class(InstanceKlass* ik) {
214 bool created;
215 _seen_classes->put_if_absent(ik, &created);
216 if (created) {
217 _all_cached_classes->append(ik);
218 if (CDSConfig::is_dumping_final_static_archive() && ik->is_shared_unregistered_class()) {
219 // The following are not appliable to unregistered classes
220 return;
221 }
222 scan_oops_in_instance_class(ik);
223 if (ik->is_hidden() && CDSConfig::is_initing_classes_at_dump_time()) {
224 bool succeed = AOTClassLinker::try_add_candidate(ik);
225 guarantee(succeed, "All cached hidden classes must be aot-linkable");
226 add_aot_inited_class(ik);
227 }
228 }
229 }
230
231 void AOTArtifactFinder::add_cached_type_array_class(TypeArrayKlass* tak) {
232 bool created;
233 _seen_classes->put_if_absent(tak, &created);
234 if (created) {
235 _all_cached_classes->append(tak);
236 scan_oops_in_array_class(tak);
237 }
238 }
239
240 void AOTArtifactFinder::add_cached_class(Klass* k) {
241 if (k->is_typeArray_klass()) {
242 add_cached_type_array_class(TypeArrayKlass::cast(k));
243 } else if (k->is_objArray_klass()) {
244 add_cached_class(ObjArrayKlass::cast(k)->element_klass());
245 } else {
246 add_cached_instance_class(InstanceKlass::cast(k));
247 }
248 }
249
250 void AOTArtifactFinder::scan_oops_in_instance_class(InstanceKlass* ik) {
251 #if INCLUDE_CDS_JAVA_HEAP
252 if (CDSConfig::is_dumping_heap()) {
253 HeapShared::scan_java_class(ik);
254 scan_oops_in_array_class(ik->array_klasses());
255 }
256 #endif
257 }
258
259 void AOTArtifactFinder::scan_oops_in_array_class(ArrayKlass* ak) {
260 #if INCLUDE_CDS_JAVA_HEAP
261 if (CDSConfig::is_dumping_heap()) {
262 while (ak != nullptr) {
263 HeapShared::scan_java_class(ak);
264 ak = ak->array_klass_or_null();
265 }
266 }
267 #endif
268 }
269
270 void AOTArtifactFinder::all_cached_classes_do(MetaspaceClosure* it) {
271 for (int i = 0; i < _all_cached_classes->length(); i++) {
272 it->push(_all_cached_classes->adr_at(i));
273 }
274 }