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/aotReferenceObjSupport.hpp"
29 #include "cds/dumpTimeClassInfo.inline.hpp"
30 #include "cds/heapShared.hpp"
31 #include "cds/lambdaProxyClassDictionary.hpp"
32 #include "classfile/systemDictionaryShared.hpp"
33 #include "logging/log.hpp"
34 #include "memory/metaspaceClosure.hpp"
35 #include "oops/instanceKlass.hpp"
36 #include "oops/objArrayKlass.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 AOTReferenceObjSupport::init_keep_alive_objs_table();
78
79 start_scanning_for_oops();
80
81 // Add the primitive array classes
82 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
83 BasicType bt = (BasicType)i;
84 if (is_java_primitive(bt)) {
85 add_cached_type_array_class(Universe::typeArrayKlass(bt));
86 }
87 }
88
89 #if INCLUDE_CDS_JAVA_HEAP
90 // Add the mirrors that aren't associated with a Klass
91 // - primitive mirrors (E.g., "int.class" in Java code)
92 // - mirror of fillerArrayKlass
93 if (CDSConfig::is_dumping_heap()) {
94 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
95 BasicType bt = (BasicType)i;
96 if (!is_reference_type(bt)) {
97 oop orig_mirror = Universe::java_mirror(bt);
98 oop scratch_mirror = HeapShared::scratch_java_mirror(bt);
99 HeapShared::scan_java_mirror(orig_mirror);
100 log_trace(cds, heap, mirror)(
101 "Archived %s mirror object from " PTR_FORMAT,
102 type2name(bt), p2i(scratch_mirror));
103 Universe::set_archived_basic_type_mirror_index(bt, HeapShared::append_root(scratch_mirror));
104 }
105 }
106
107 // Universe::fillerArrayKlass() isn't in the class hierarchy, so handle it specially.
108 HeapShared::scan_java_mirror(Universe::fillerArrayKlass()->java_mirror());
109 }
110 #endif
111
112 // Add all the InstanceKlasses (and their array classes) that are always included.
113 SystemDictionaryShared::dumptime_table()->iterate_all_live_classes([&] (InstanceKlass* ik, DumpTimeClassInfo& info) {
114 // Skip "AOT tooling classes" in this block. They will be included in the AOT cache only if
115 // - One of their subtypes is included
116 // - One of their instances is found by HeapShared.
117 if (!info.is_excluded() && !info.is_aot_tooling_class()) {
118 bool add = false;
119 if (!ik->is_hidden()) {
120 // All non-hidden classes are always included into the AOT cache
121 add = true;
122 } else {
123 if (CDSConfig::is_dumping_lambdas_in_legacy_mode()) {
124 // Legacy support of lambda proxies -- these are always included into the AOT cache
125 if (LambdaProxyClassDictionary::is_registered_lambda_proxy_class(ik)) {
126 add = true;
127 }
128 } else {
129 assert(!LambdaProxyClassDictionary::is_registered_lambda_proxy_class(ik),
130 "registered lambda proxies are only for legacy lambda proxy support");
131 }
132 }
133
134 if (add) {
135 add_cached_instance_class(ik);
136 if (AOTClassInitializer::can_archive_initialized_mirror(ik)) {
137 add_aot_inited_class(ik);
138 }
139 }
140 }
141 });
142
143 #if INCLUDE_CDS_JAVA_HEAP
144 // Keep scanning until we discover no more class that need to be AOT-initialized.
145 if (CDSConfig::is_initing_classes_at_dump_time()) {
146 while (_pending_aot_inited_classes->length() > 0) {
147 InstanceKlass* ik = _pending_aot_inited_classes->pop();
148 HeapShared::copy_and_rescan_aot_inited_mirror(ik);
149 }
150 }
151 #endif
152
153 // Exclude all the (hidden) classes that have not been discovered by the code above.
154 SystemDictionaryShared::dumptime_table()->iterate_all_live_classes([&] (InstanceKlass* k, DumpTimeClassInfo& info) {
155 if (!info.is_excluded() && _seen_classes->get(k) == nullptr) {
156 info.set_excluded();
157 info.set_has_checked_exclusion();
158 if (log_is_enabled(Debug, cds)) {
159 ResourceMark rm;
160 log_debug(cds)("Skipping %s: %s class", k->name()->as_C_string(),
161 k->is_hidden() ? "Unreferenced hidden" : "AOT tooling");
162 }
163 }
164 });
165
166 end_scanning_for_oops();
167 }
168
169 void AOTArtifactFinder::start_scanning_for_oops() {
170 #if INCLUDE_CDS_JAVA_HEAP
171 if (CDSConfig::is_dumping_heap()) {
172 HeapShared::start_scanning_for_oops();
173 }
174 #endif
175 }
176
177 void AOTArtifactFinder::end_scanning_for_oops() {
178 #if INCLUDE_CDS_JAVA_HEAP
179 if (CDSConfig::is_dumping_heap()) {
180 HeapShared::end_scanning_for_oops();
181 }
182 #endif
183 }
184
185 void AOTArtifactFinder::add_aot_inited_class(InstanceKlass* ik) {
186 if (CDSConfig::is_initing_classes_at_dump_time()) {
187 assert(ik->is_initialized(), "must be");
188 add_cached_instance_class(ik);
189
190 bool created;
191 _aot_inited_classes->put_if_absent(ik, &created);
192 if (created) {
193 _pending_aot_inited_classes->push(ik);
194
195 InstanceKlass* s = ik->java_super();
196 if (s != nullptr) {
197 add_aot_inited_class(s);
198 }
199
200 Array<InstanceKlass*>* interfaces = ik->local_interfaces();
201 int len = interfaces->length();
202 for (int i = 0; i < len; i++) {
203 InstanceKlass* intf = interfaces->at(i);
204 if (intf->is_initialized()) {
205 add_aot_inited_class(intf);
206 }
207 }
208 }
209 }
210 }
211
212 void AOTArtifactFinder::append_to_all_cached_classes(Klass* k) {
213 precond(!SystemDictionaryShared::should_be_excluded(k));
214 _all_cached_classes->append(k);
215 }
216
217 void AOTArtifactFinder::add_cached_instance_class(InstanceKlass* ik) {
218 if (CDSConfig::is_dumping_dynamic_archive() && ik->is_shared()) {
219 // This class is already included in the base archive. No need to cache
220 // it again in the dynamic archive.
221 return;
222 }
223
224 bool created;
225 _seen_classes->put_if_absent(ik, &created);
226 if (created) {
227 append_to_all_cached_classes(ik);
228
229 // All super types must be added.
230 InstanceKlass* s = ik->java_super();
231 if (s != nullptr) {
232 add_cached_instance_class(s);
233 }
234
235 Array<InstanceKlass*>* interfaces = ik->local_interfaces();
236 int len = interfaces->length();
237 for (int i = 0; i < len; i++) {
238 InstanceKlass* intf = interfaces->at(i);
239 add_cached_instance_class(intf);
240 }
241
242 if (CDSConfig::is_dumping_final_static_archive() && ik->is_shared_unregistered_class()) {
243 // The following are not appliable to unregistered classes
244 return;
245 }
246 scan_oops_in_instance_class(ik);
247 if (ik->is_hidden() && CDSConfig::is_initing_classes_at_dump_time()) {
248 bool succeed = AOTClassLinker::try_add_candidate(ik);
249 guarantee(succeed, "All cached hidden classes must be aot-linkable");
250 add_aot_inited_class(ik);
251 }
252 }
253 }
254
255 void AOTArtifactFinder::add_cached_type_array_class(TypeArrayKlass* tak) {
256 bool created;
257 _seen_classes->put_if_absent(tak, &created);
258 if (created) {
259 append_to_all_cached_classes(tak);
260 scan_oops_in_array_class(tak);
261 }
262 }
263
264 void AOTArtifactFinder::add_cached_class(Klass* k) {
265 if (k->is_typeArray_klass()) {
266 add_cached_type_array_class(TypeArrayKlass::cast(k));
267 } else if (k->is_objArray_klass()) {
268 add_cached_class(ObjArrayKlass::cast(k)->element_klass());
269 } else {
270 add_cached_instance_class(InstanceKlass::cast(k));
271 }
272 }
273
274 void AOTArtifactFinder::scan_oops_in_instance_class(InstanceKlass* ik) {
275 #if INCLUDE_CDS_JAVA_HEAP
276 if (CDSConfig::is_dumping_heap()) {
277 HeapShared::scan_java_class(ik);
278 scan_oops_in_array_class(ik->array_klasses());
279 }
280 #endif
281 }
282
283 void AOTArtifactFinder::scan_oops_in_array_class(ArrayKlass* ak) {
284 #if INCLUDE_CDS_JAVA_HEAP
285 if (CDSConfig::is_dumping_heap()) {
286 while (ak != nullptr) {
287 HeapShared::scan_java_class(ak);
288 ak = ak->array_klass_or_null();
289 }
290 }
291 #endif
292 }
293
294 void AOTArtifactFinder::all_cached_classes_do(MetaspaceClosure* it) {
295 for (int i = 0; i < _all_cached_classes->length(); i++) {
296 it->push(_all_cached_classes->adr_at(i));
297 }
298 }