1 /*
2 * Copyright (c) 2020, 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/aotLogging.hpp"
26 #include "cds/cdsConfig.hpp"
27 #include "cds/heapShared.hpp"
28 #include "cds/serializeClosure.hpp"
29 #include "classfile/classLoaderData.inline.hpp"
30 #include "classfile/classLoaderDataShared.hpp"
31 #include "classfile/moduleEntry.hpp"
32 #include "classfile/modules.hpp"
33 #include "classfile/packageEntry.hpp"
34 #include "classfile/systemDictionary.hpp"
35 #include "logging/log.hpp"
36 #include "runtime/handles.inline.hpp"
37 #include "runtime/safepoint.hpp"
38
39 #if INCLUDE_CDS_JAVA_HEAP
40
41 bool ClassLoaderDataShared::_full_module_graph_loaded = false;
42
43 class ArchivedClassLoaderData {
44 Array<PackageEntry*>* _packages;
45 Array<ModuleEntry*>* _modules;
46 ModuleEntry* _unnamed_module;
47
48 void assert_valid(ClassLoaderData* loader_data) {
49 // loader_data may be null if the boot layer has loaded no modules for the platform or
50 // system loaders (e.g., if you create a custom JDK image with only java.base).
51 if (loader_data != nullptr) {
52 assert(!loader_data->has_class_mirror_holder(),
53 "loaders for non-strong hidden classes not supported");
54 }
55 }
56 public:
57 ArchivedClassLoaderData() : _packages(nullptr), _modules(nullptr), _unnamed_module(nullptr) {}
58
59 void iterate_symbols(ClassLoaderData* loader_data, MetaspaceClosure* closure);
60 void allocate(ClassLoaderData* loader_data);
61 void init_archived_entries(ClassLoaderData* loader_data);
62 ModuleEntry* unnamed_module() {
63 return _unnamed_module;
64 }
65
66 void serialize(SerializeClosure* f) {
67 f->do_ptr(&_packages);
68 f->do_ptr(&_modules);
69 f->do_ptr(&_unnamed_module);
70 }
71
72 void restore(ClassLoaderData* loader_data, bool do_entries, bool do_oops);
73 void clear_archived_oops();
74 };
75
76 static ArchivedClassLoaderData _archived_boot_loader_data;
77 static ArchivedClassLoaderData _archived_platform_loader_data;
78 static ArchivedClassLoaderData _archived_system_loader_data;
79 static ModuleEntry* _archived_javabase_moduleEntry = nullptr;
80 static int _platform_loader_root_index = -1;
81 static int _system_loader_root_index = -1;
82
83 void ArchivedClassLoaderData::iterate_symbols(ClassLoaderData* loader_data, MetaspaceClosure* closure) {
84 assert(CDSConfig::is_dumping_full_module_graph(), "must be");
85 assert_valid(loader_data);
86 if (loader_data != nullptr) {
87 loader_data->packages()->iterate_symbols(closure);
88 loader_data->modules() ->iterate_symbols(closure);
89 loader_data->unnamed_module()->iterate_symbols(closure);
90 }
91 }
92
93 void ArchivedClassLoaderData::allocate(ClassLoaderData* loader_data) {
94 assert(CDSConfig::is_dumping_full_module_graph(), "must be");
95 assert_valid(loader_data);
96 if (loader_data != nullptr) {
97 // We can't create hashtables at dump time because the hashcode depends on the
98 // address of the Symbols, which may be relocated at runtime due to ASLR.
99 // So we store the packages/modules in Arrays. At runtime, we create
100 // the hashtables using these arrays.
101 _packages = loader_data->packages()->allocate_archived_entries();
102 _modules = loader_data->modules() ->allocate_archived_entries();
103 _unnamed_module = loader_data->unnamed_module()->allocate_archived_entry();
104 }
105 }
106
107 void ArchivedClassLoaderData::init_archived_entries(ClassLoaderData* loader_data) {
108 assert(CDSConfig::is_dumping_full_module_graph(), "must be");
109 assert_valid(loader_data);
110 if (loader_data != nullptr) {
111 loader_data->packages()->init_archived_entries(_packages);
112 loader_data->modules() ->init_archived_entries(_modules);
113 _unnamed_module->init_as_archived_entry();
114 }
115 }
116
117 void ArchivedClassLoaderData::restore(ClassLoaderData* loader_data, bool do_entries, bool do_oops) {
118 assert(CDSConfig::is_using_archive(), "must be");
119 assert_valid(loader_data);
120 if (_modules != nullptr) { // Could be null if we have archived no modules for platform/system loaders
121 ModuleEntryTable* modules = loader_data->modules();
122 PackageEntryTable* packages = loader_data->packages();
123
124 MutexLocker m1(Module_lock);
125 if (do_entries) {
126 modules->load_archived_entries(loader_data, _modules);
127 packages->load_archived_entries(_packages);
128 }
129 if (do_oops) {
130 modules->restore_archived_oops(loader_data, _modules);
131 if (_unnamed_module != nullptr) {
132 oop module_oop = _unnamed_module->module_oop();
133 assert(module_oop != nullptr, "must be already set");
134 assert(_unnamed_module == java_lang_Module::module_entry(module_oop), "must be already set");
135 assert(loader_data->class_loader() == java_lang_Module::loader(module_oop), "must be set in dump time");
136 }
137 }
138 }
139 }
140
141 void ArchivedClassLoaderData::clear_archived_oops() {
142 assert(CDSConfig::is_using_archive(), "must be");
143 if (_modules != nullptr) {
144 for (int i = 0; i < _modules->length(); i++) {
145 _modules->at(i)->clear_archived_oops();
146 }
147 if (_unnamed_module != nullptr) {
148 _unnamed_module->clear_archived_oops();
149 }
150 }
151 }
152
153 // ------------------------------
154
155 static ClassLoaderData* null_class_loader_data() {
156 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
157 assert(loader_data != nullptr, "must be");
158 return loader_data;
159 }
160
161 static ClassLoaderData* java_platform_loader_data_or_null() {
162 return ClassLoaderData::class_loader_data_or_null(SystemDictionary::java_platform_loader());
163 }
164
165 static ClassLoaderData* java_system_loader_data_or_null() {
166 return ClassLoaderData::class_loader_data_or_null(SystemDictionary::java_system_loader());
167 }
168
169 // ModuleEntryTables (even if empty) are required for iterate_symbols() to scan the
170 // platform/system loaders inside the CDS safepoint, but the tables can be created only
171 // when outside of safepoints. Let's do that now.
172 void ClassLoaderDataShared::ensure_module_entry_tables_exist() {
173 assert(!SafepointSynchronize::is_at_safepoint(), "sanity");
174 ensure_module_entry_table_exists(SystemDictionary::java_platform_loader());
175 ensure_module_entry_table_exists(SystemDictionary::java_system_loader());
176 }
177
178 void ClassLoaderDataShared::ensure_module_entry_table_exists(oop class_loader) {
179 Handle h_loader(JavaThread::current(), class_loader);
180 ModuleEntryTable* met = Modules::get_module_entry_table(h_loader);
181 assert(met != nullptr, "sanity");
182 }
183
184 void ClassLoaderDataShared::iterate_symbols(MetaspaceClosure* closure) {
185 assert(CDSConfig::is_dumping_full_module_graph(), "must be");
186 _archived_boot_loader_data.iterate_symbols (null_class_loader_data(), closure);
187 _archived_platform_loader_data.iterate_symbols(java_platform_loader_data_or_null(), closure);
188 _archived_system_loader_data.iterate_symbols (java_system_loader_data_or_null(), closure);
189 }
190
191 void ClassLoaderDataShared::allocate_archived_tables() {
192 assert(CDSConfig::is_dumping_full_module_graph(), "must be");
193 _archived_boot_loader_data.allocate (null_class_loader_data());
194 _archived_platform_loader_data.allocate(java_platform_loader_data_or_null());
195 _archived_system_loader_data.allocate (java_system_loader_data_or_null());
196 }
197
198 void ClassLoaderDataShared::init_archived_tables() {
199 assert(CDSConfig::is_dumping_full_module_graph(), "must be");
200
201 _archived_boot_loader_data.init_archived_entries (null_class_loader_data());
202 _archived_platform_loader_data.init_archived_entries(java_platform_loader_data_or_null());
203 _archived_system_loader_data.init_archived_entries (java_system_loader_data_or_null());
204
205 _archived_javabase_moduleEntry = ModuleEntry::get_archived_entry(ModuleEntryTable::javabase_moduleEntry());
206
207 _platform_loader_root_index = HeapShared::append_root(SystemDictionary::java_platform_loader());
208 _system_loader_root_index = HeapShared::append_root(SystemDictionary::java_system_loader());
209 }
210
211 void ClassLoaderDataShared::serialize(SerializeClosure* f) {
212 _archived_boot_loader_data.serialize(f);
213 _archived_platform_loader_data.serialize(f);
214 _archived_system_loader_data.serialize(f);
215 f->do_ptr(&_archived_javabase_moduleEntry);
216 f->do_int(&_platform_loader_root_index);
217 f->do_int(&_system_loader_root_index);
218 }
219
220 ModuleEntry* ClassLoaderDataShared::archived_boot_unnamed_module() {
221 if (CDSConfig::is_using_full_module_graph()) {
222 return _archived_boot_loader_data.unnamed_module();
223 } else {
224 return nullptr;
225 }
226 }
227
228 ModuleEntry* ClassLoaderDataShared::archived_unnamed_module(ClassLoaderData* loader_data) {
229 ModuleEntry* archived_module = nullptr;
230
231 if (!Universe::is_module_initialized() && CDSConfig::is_using_full_module_graph()) {
232 precond(_platform_loader_root_index >= 0);
233 precond(_system_loader_root_index >= 0);
234
235 if (loader_data->class_loader() == HeapShared::get_root(_platform_loader_root_index)) {
236 archived_module = _archived_platform_loader_data.unnamed_module();
237 } else if (loader_data->class_loader() == HeapShared::get_root(_system_loader_root_index)) {
238 archived_module = _archived_system_loader_data.unnamed_module();
239 }
240 }
241
242 return archived_module;
243 }
244
245
246 void ClassLoaderDataShared::clear_archived_oops() {
247 assert(!CDSConfig::is_using_full_module_graph(), "must be");
248 _archived_boot_loader_data.clear_archived_oops();
249 _archived_platform_loader_data.clear_archived_oops();
250 _archived_system_loader_data.clear_archived_oops();
251 if (_platform_loader_root_index >= 0) {
252 HeapShared::clear_root(_platform_loader_root_index);
253 HeapShared::clear_root(_system_loader_root_index);
254 }
255 }
256
257 // Must be done before ClassLoader::create_javabase()
258 void ClassLoaderDataShared::restore_archived_entries_for_null_class_loader_data() {
259 precond(CDSConfig::is_using_full_module_graph());
260 _archived_boot_loader_data.restore(null_class_loader_data(), true, false);
261 ModuleEntryTable::set_javabase_moduleEntry(_archived_javabase_moduleEntry);
262 aot_log_info(aot)("use_full_module_graph = true; java.base = " INTPTR_FORMAT,
263 p2i(_archived_javabase_moduleEntry));
264 }
265
266 oop ClassLoaderDataShared::restore_archived_oops_for_null_class_loader_data() {
267 assert(CDSConfig::is_using_full_module_graph(), "must be");
268 _archived_boot_loader_data.restore(null_class_loader_data(), false, true);
269 return _archived_javabase_moduleEntry->module_oop();
270 }
271
272 void ClassLoaderDataShared::restore_java_platform_loader_from_archive(ClassLoaderData* loader_data) {
273 assert(CDSConfig::is_using_full_module_graph(), "must be");
274 _archived_platform_loader_data.restore(loader_data, true, true);
275 }
276
277 void ClassLoaderDataShared::restore_java_system_loader_from_archive(ClassLoaderData* loader_data) {
278 assert(CDSConfig::is_using_full_module_graph(), "must be");
279 _archived_system_loader_data.restore(loader_data, true, true);
280 _full_module_graph_loaded = true;
281 }
282
283 #endif // INCLUDE_CDS_JAVA_HEAP