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