1 /*
2 * Copyright (c) 2024, 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/aotConstantPoolResolver.hpp"
27 #include "cds/aotLinkedClassTable.hpp"
28 #include "cds/archiveBuilder.hpp"
29 #include "cds/archiveUtils.inline.hpp"
30 #include "cds/cdsConfig.hpp"
31 #include "cds/heapShared.hpp"
32 #include "cds/lambdaFormInvokers.inline.hpp"
33 #include "classfile/classLoader.hpp"
34 #include "classfile/dictionary.hpp"
35 #include "classfile/systemDictionary.hpp"
36 #include "classfile/systemDictionaryShared.hpp"
37 #include "classfile/vmClasses.hpp"
38 #include "memory/resourceArea.hpp"
39 #include "oops/constantPool.inline.hpp"
40 #include "oops/instanceKlass.hpp"
41 #include "oops/klass.inline.hpp"
42 #include "runtime/handles.inline.hpp"
43
44 AOTClassLinker::ClassesTable* AOTClassLinker::_vm_classes = nullptr;
45 AOTClassLinker::ClassesTable* AOTClassLinker::_candidates = nullptr;
46 GrowableArrayCHeap<InstanceKlass*, mtClassShared>* AOTClassLinker::_sorted_candidates = nullptr;
47
48 #ifdef ASSERT
49 bool AOTClassLinker::is_initialized() {
50 assert(CDSConfig::is_dumping_archive(), "AOTClassLinker is for CDS dumping only");
51 return _vm_classes != nullptr;
52 }
53 #endif
54
55 void AOTClassLinker::initialize() {
56 assert(!is_initialized(), "sanity");
57
58 _vm_classes = new (mtClass)ClassesTable();
59 _candidates = new (mtClass)ClassesTable();
60 _sorted_candidates = new GrowableArrayCHeap<InstanceKlass*, mtClassShared>(1000);
61
62 for (auto id : EnumRange<vmClassID>{}) {
63 add_vm_class(vmClasses::klass_at(id));
64 }
65
66 assert(is_initialized(), "sanity");
67
68 AOTConstantPoolResolver::initialize();
69 }
70
71 void AOTClassLinker::dispose() {
72 assert(is_initialized(), "sanity");
73
74 delete _vm_classes;
75 delete _candidates;
76 delete _sorted_candidates;
77 _vm_classes = nullptr;
78 _candidates = nullptr;
79 _sorted_candidates = nullptr;
80
81 assert(!is_initialized(), "sanity");
82
83 AOTConstantPoolResolver::dispose();
84 }
85
86 bool AOTClassLinker::is_vm_class(InstanceKlass* ik) {
87 assert(is_initialized(), "sanity");
88 return (_vm_classes->get(ik) != nullptr);
89 }
90
91 void AOTClassLinker::add_vm_class(InstanceKlass* ik) {
92 assert(is_initialized(), "sanity");
93 bool created;
94 _vm_classes->put_if_absent(ik, &created);
95 if (created) {
96 if (CDSConfig::is_dumping_aot_linked_classes()) {
97 bool v = try_add_candidate(ik);
98 assert(v, "must succeed for VM class");
99 }
100 InstanceKlass* super = ik->java_super();
101 if (super != nullptr) {
102 add_vm_class(super);
103 }
104 Array<InstanceKlass*>* ifs = ik->local_interfaces();
105 for (int i = 0; i < ifs->length(); i++) {
106 add_vm_class(ifs->at(i));
107 }
108 }
109 }
110
111 bool AOTClassLinker::is_candidate(InstanceKlass* ik) {
112 return (_candidates->get(ik) != nullptr);
113 }
114
115 void AOTClassLinker::add_new_candidate(InstanceKlass* ik) {
116 assert(!is_candidate(ik), "caller need to check");
117 _candidates->put_when_absent(ik, true);
118 _sorted_candidates->append(ik);
119
120 if (log_is_enabled(Info, cds, aot, link)) {
121 ResourceMark rm;
122 log_info(cds, aot, link)("%s %s %p", class_category_name(ik), ik->external_name(), ik);
123 }
124 }
125
126 // ik is a candidate for aot-linking; see if it can really work
127 // that way, and return success or failure. Not only must ik itself
128 // look like a class that can be aot-linked but its supers must also be
129 // aot-linkable.
130 bool AOTClassLinker::try_add_candidate(InstanceKlass* ik) {
131 assert(is_initialized(), "sanity");
132 assert(CDSConfig::is_dumping_aot_linked_classes(), "sanity");
133
134 if (!SystemDictionaryShared::is_builtin(ik)) {
135 // not loaded by a class loader which we know about
136 return false;
137 }
138
139 if (is_candidate(ik)) { // already checked.
140 return true;
141 }
142
143 if (ik->is_hidden()) {
144 assert(ik->shared_class_loader_type() != ClassLoader::OTHER, "must have been set");
145 if (!CDSConfig::is_dumping_invokedynamic()) {
146 return false;
147 }
148 if (HeapShared::is_lambda_proxy_klass(ik)) {
149 InstanceKlass* nest_host = ik->nest_host_not_null();
150 if (!try_add_candidate(nest_host)) {
151 ResourceMark rm;
152 log_warning(cds, aot, link)("%s cannot be aot-linked because it nest host is not aot-linked", ik->external_name());
153 return false;
154 }
155 }
156 }
157
158 InstanceKlass* s = ik->java_super();
159 if (s != nullptr && !try_add_candidate(s)) {
160 return false;
161 }
162
163 Array<InstanceKlass*>* interfaces = ik->local_interfaces();
164 int num_interfaces = interfaces->length();
165 for (int index = 0; index < num_interfaces; index++) {
166 InstanceKlass* intf = interfaces->at(index);
167 if (!try_add_candidate(intf)) {
168 return false;
169 }
170 }
171
172 // There are no loops in the class hierarchy, and this function is always called single-threaded, so
173 // we know ik has not been added yet.
174 assert(CDSConfig::current_thread_is_vm_or_dumper(), "that's why we don't need locks");
175 add_new_candidate(ik);
176
177 return true;
178 }
179
180 void AOTClassLinker::add_candidates() {
181 assert_at_safepoint();
182 if (CDSConfig::is_dumping_aot_linked_classes()) {
183 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
184 for (GrowableArrayIterator<Klass*> it = klasses->begin(); it != klasses->end(); ++it) {
185 Klass* k = *it;
186 if (k->is_instance_klass()) {
187 try_add_candidate(InstanceKlass::cast(k));
188 }
189 }
190 }
191 }
192
193 void AOTClassLinker::write_to_archive() {
194 assert(is_initialized(), "sanity");
195 assert_at_safepoint();
196
197 if (CDSConfig::is_dumping_aot_linked_classes()) {
198 AOTLinkedClassTable* table = AOTLinkedClassTable::get(CDSConfig::is_dumping_static_archive());
199 table->set_boot(write_classes(nullptr, true));
200 table->set_boot2(write_classes(nullptr, false));
201 table->set_platform(write_classes(SystemDictionary::java_platform_loader(), false));
202 table->set_app(write_classes(SystemDictionary::java_system_loader(), false));
203 }
204 }
205
206 Array<InstanceKlass*>* AOTClassLinker::write_classes(oop class_loader, bool is_javabase) {
207 ResourceMark rm;
208 GrowableArray<InstanceKlass*> list;
209
210 for (int i = 0; i < _sorted_candidates->length(); i++) {
211 InstanceKlass* ik = _sorted_candidates->at(i);
212 if (ik->class_loader() != class_loader) {
213 continue;
214 }
215 if ((ik->module() == ModuleEntryTable::javabase_moduleEntry()) != is_javabase) {
216 continue;
217 }
218
219 if (ik->is_shared() && CDSConfig::is_dumping_dynamic_archive()) {
220 if (CDSConfig::is_using_aot_linked_classes()) {
221 // This class was recorded as AOT-linked for the base archive,
222 // so there's no need to do so again for the dynamic archive.
223 } else {
224 list.append(ik);
225 }
226 } else {
227 list.append(ArchiveBuilder::current()->get_buffered_addr(ik));
228 }
229 }
230
231 if (list.length() == 0) {
232 return nullptr;
233 } else {
234 const char* category = class_category_name(list.at(0));
235 log_info(cds, aot, link)("wrote %d class(es) for category %s", list.length(), category);
236 return ArchiveUtils::archive_array(&list);
237 }
238 }
239
240 int AOTClassLinker::num_platform_initiated_classes() {
241 if (CDSConfig::is_dumping_aot_linked_classes()) {
242 // AOTLinkedClassBulkLoader will initiate loading of all public boot classes in the platform loader.
243 return count_public_classes(nullptr);
244 } else {
245 return 0;
246 }
247 }
248
249 int AOTClassLinker::num_app_initiated_classes() {
250 if (CDSConfig::is_dumping_aot_linked_classes()) {
251 // AOTLinkedClassBulkLoader will initiate loading of all public boot/platform classes in the app loader.
252 return count_public_classes(nullptr) + count_public_classes(SystemDictionary::java_platform_loader());
253 } else {
254 return 0;
255 }
256 }
257
258 int AOTClassLinker::count_public_classes(oop loader) {
259 int n = 0;
260 for (int i = 0; i < _sorted_candidates->length(); i++) {
261 InstanceKlass* ik = _sorted_candidates->at(i);
262 if (ik->is_public() && !ik->is_hidden() && ik->class_loader() == loader) {
263 n++;
264 }
265 }
266
267 return n;
268 }
269
270 // Used in logging: "boot1", "boot2", "plat", "app" and "unreg", or "array"
271 const char* AOTClassLinker::class_category_name(Klass* k) {
272 if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(k)) {
273 k = ArchiveBuilder::current()->get_source_addr(k);
274 }
275
276 if (k->is_array_klass()) {
277 return "array";
278 } else {
279 oop loader = k->class_loader();
280 if (loader == nullptr) {
281 if (k->module() != nullptr &&
282 k->module()->name() != nullptr &&
283 k->module()->name()->equals("java.base")) {
284 return "boot1"; // boot classes in java.base are loaded in the 1st phase
285 } else {
286 return "boot2"; // boot classes outside of java.base are loaded in the 2nd phase phase
287 }
288 } else {
289 if (loader == SystemDictionary::java_platform_loader()) {
290 return "plat";
291 } else if (loader == SystemDictionary::java_system_loader()) {
292 return "app";
293 } else {
294 return "unreg";
295 }
296 }
297 }
298 }
299
300 const char* AOTClassLinker::class_category_name(AOTLinkedClassCategory category) {
301 switch (category) {
302 case AOTLinkedClassCategory::BOOT1:
303 return "boot1";
304 case AOTLinkedClassCategory::BOOT2:
305 return "boot2";
306 case AOTLinkedClassCategory::PLATFORM:
307 return "plat";
308 case AOTLinkedClassCategory::APP:
309 return "app";
310 case AOTLinkedClassCategory::UNREGISTERED:
311 default:
312 return "unreg";
313 }
314 }