1 /*
2 * Copyright (c) 2014, 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.
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23 */
24
25 #ifndef SHARE_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP
26 #define SHARE_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP
27
28 #include "cds/cds_globals.hpp"
29 #include "cds/dumpTimeClassInfo.hpp"
30 #include "cds/filemap.hpp"
31 #include "cds/runTimeClassInfo.hpp"
32 #include "classfile/classLoaderData.hpp"
33 #include "classfile/packageEntry.hpp"
34 #include "classfile/systemDictionary.hpp"
35 #include "oops/klass.hpp"
36 #include "oops/oopHandle.hpp"
37 #include "oops/trainingData.hpp"
38
39
40 /*===============================================================================
41
42 Handling of the classes in the AppCDS archive
43
44 To ensure safety and to simplify the implementation, archived classes are
45 "segregated" into 2 types. The following rules describe how they
46 are stored and looked up.
47
48 [1] Category of archived classes
49
50 There are 2 disjoint groups of classes stored in the AppCDS archive:
51
52 BUILTIN: These classes may be defined ONLY by the BOOT/PLATFORM/APP
53 loaders.
54
55 UNREGISTERED: These classes may be defined ONLY by a ClassLoader
56 instance that's not listed above (using fingerprint matching)
57
58 [2] How classes from different categories are specified in the classlist:
59
60 Starting from JDK9, each class in the classlist may be specified with
61 these keywords: "id", "super", "interfaces", "loader" and "source".
62
63
64 BUILTIN Only the "id" keyword may be (optionally) specified. All other
65 keywords are forbidden.
66
67 The named class is looked up from the jimage and from
68 Xbootclasspath/a and CLASSPATH.
69
70 UNREGISTERED: The "id", "super", and "source" keywords must all be
71 specified.
72
73 The "interfaces" keyword must be specified if the class implements
74 one or more local interfaces. The "interfaces" keyword must not be
75 specified if the class does not implement local interfaces.
76
77 The named class is looked up from the location specified in the
78 "source" keyword.
79
80 Example classlist:
81
82 # BUILTIN
83 java/lang/Object id: 0
84 java/lang/Cloneable id: 1
85 java/lang/String
86
87 # UNREGISTERED
88 Bar id: 3 super: 0 interfaces: 1 source: /foo.jar
89
90
91 [3] Identifying the category of archived classes
92
93 BUILTIN: (C->shared_classpath_index() >= 0)
94 UNREGISTERED: (C->shared_classpath_index() == UNREGISTERED_INDEX (-9999))
95
96 [4] Lookup of archived classes at run time:
97
98 (a) BUILTIN loaders:
99
100 search _builtin_dictionary
101
102 (b) UNREGISTERED loaders:
103
104 search _unregistered_dictionary for an entry that matches the
105 (name, clsfile_len, clsfile_crc32).
106
107 ===============================================================================*/
108 #define UNREGISTERED_INDEX -9999
109
110 class BootstrapInfo;
111 class ClassFileStream;
112 class ConstantPoolCache;
113 class Dictionary;
114 class DumpTimeClassInfo;
115 class DumpTimeSharedClassTable;
116 class RunTimeClassInfo;
117 class RunTimeSharedDictionary;
118
119 template <typename E> class GrowableArray;
120
121 class SharedClassLoadingMark {
122 private:
123 Thread* THREAD;
124 InstanceKlass* _klass;
125 public:
126 SharedClassLoadingMark(Thread* current, InstanceKlass* ik) : THREAD(current), _klass(ik) {}
127 ~SharedClassLoadingMark() {
128 assert(THREAD != nullptr, "Current thread is nullptr");
129 assert(_klass != nullptr, "InstanceKlass is nullptr");
130 if (HAS_PENDING_EXCEPTION) {
131 if (_klass->in_aot_cache()) {
132 _klass->set_shared_loading_failed();
133 }
134 }
135 }
136 };
137
138 class SystemDictionaryShared: public SystemDictionary {
139 friend class LambdaProxyClassDictionary;
140
141 struct ArchiveInfo {
142 RunTimeSharedDictionary _builtin_dictionary;
143 RunTimeSharedDictionary _unregistered_dictionary;
144
145 void print_on(const char* prefix, outputStream* st, bool is_static_archive);
146 void print_table_statistics(const char* prefix, outputStream* st, bool is_static_archive);
147 };
148
149 private:
150
151 static DumpTimeSharedClassTable* _dumptime_table;
152
153 static ArchiveInfo _static_archive;
154 static ArchiveInfo _dynamic_archive;
155
156 static ArchiveInfo* get_archive(bool is_static_archive) {
157 return is_static_archive ? &_static_archive : &_dynamic_archive;
158 }
159
160 static InstanceKlass* load_shared_class_for_builtin_loader(
161 Symbol* class_name,
162 Handle class_loader,
163 TRAPS);
164 static InstanceKlass* acquire_class_for_current_thread(
165 InstanceKlass *ik,
166 Handle class_loader,
167 Handle protection_domain,
168 const ClassFileStream* cfs,
169 TRAPS);
170
171
172 static void write_dictionary(RunTimeSharedDictionary* dictionary,
173 bool is_builtin);
174 static bool check_for_exclusion_impl(InstanceKlass* k);
175 static void remove_dumptime_info(InstanceKlass* k) NOT_CDS_RETURN;
176 DEBUG_ONLY(static bool _class_loading_may_happen;)
177
178 static void copy_verification_constraints_from_preimage(InstanceKlass* klass);
179 static void copy_linking_constraints_from_preimage(InstanceKlass* klass);
180
181 public:
182 // Guaranteed to return non-null value for non-shared classes.
183 // k must not be a shared class.
184 static DumpTimeClassInfo* get_info(InstanceKlass* k);
185 static DumpTimeClassInfo* get_info_locked(InstanceKlass* k);
186 static DumpTimeSharedClassTable* dumptime_table() { return _dumptime_table; }
187
188 static bool should_hidden_class_be_archived(InstanceKlass* k);
189 static void mark_required_hidden_class(InstanceKlass* k);
190 static bool has_been_redefined(InstanceKlass* k);
191 static bool is_jfr_event_class(InstanceKlass *k);
192 static bool is_early_klass(InstanceKlass* k); // Was k loaded while JvmtiExport::is_early_phase()==true
193 static bool has_archived_enum_objs(InstanceKlass* ik);
194 static void set_has_archived_enum_objs(InstanceKlass* ik);
195
196 static InstanceKlass* find_builtin_class(Symbol* class_name);
197
198 static const RunTimeClassInfo* find_record(RunTimeSharedDictionary* static_dict,
199 RunTimeSharedDictionary* dynamic_dict,
200 Symbol* name);
201
202 static bool has_platform_or_app_classes();
203
204 // Called by PLATFORM/APP loader only
205 static InstanceKlass* find_or_load_shared_class(Symbol* class_name,
206 Handle class_loader,
207 TRAPS);
208
209
210 static void allocate_shared_data_arrays(int size, TRAPS);
211
212 static bool is_builtin_loader(ClassLoaderData* loader_data);
213
214 static InstanceKlass* lookup_super_for_unregistered_class(Symbol* class_name,
215 Symbol* super_name, bool is_superclass);
216
217 static void initialize() NOT_CDS_RETURN;
218 static void init_dumptime_info(InstanceKlass* k) NOT_CDS_RETURN;
219 static void init_dumptime_info_from_preimage(InstanceKlass* k) NOT_CDS_RETURN;
220 static void handle_class_unloading(InstanceKlass* k) NOT_CDS_RETURN;
221
222 static bool can_be_preinited(InstanceKlass* ik);
223 static bool can_be_preinited_locked(InstanceKlass* ik);
224 static void reset_preinit_check();
225
226 static Dictionary* boot_loader_dictionary() {
227 return ClassLoaderData::the_null_class_loader_data()->dictionary();
228 }
229
230 static void update_shared_entry(InstanceKlass* klass, int id);
231 static void set_shared_class_misc_info(InstanceKlass* k, ClassFileStream* cfs);
232
233 static InstanceKlass* lookup_from_stream(Symbol* class_name,
234 Handle class_loader,
235 Handle protection_domain,
236 const ClassFileStream* st,
237 TRAPS);
238 // "verification_constraints" are a set of checks performed by
239 // VerificationType::is_reference_assignable_from when verifying a shared class during
240 // dump time.
241 //
242 // With AppCDS, it is possible to override archived classes by calling
243 // ClassLoader.defineClass() directly. SystemDictionary::load_shared_class() already
244 // ensures that you cannot load a shared class if its super type(s) are changed. However,
245 // we need an additional check to ensure that the verification_constraints did not change
246 // between dump time and runtime.
247 static void add_verification_constraint(InstanceKlass* k, Symbol* name,
248 Symbol* from_name, bool from_field_is_protected,
249 bool from_is_array, bool from_is_object,
250 bool* skip_assignability_check);
251 static void check_verification_constraints(InstanceKlass* klass,
252 TRAPS) NOT_CDS_RETURN;
253 static void add_enum_klass_static_field(InstanceKlass* ik, int root_index);
254 static void set_class_has_failed_verification(InstanceKlass* ik) NOT_CDS_RETURN;
255 static bool has_class_failed_verification(InstanceKlass* ik) NOT_CDS_RETURN_(false);
256 static bool check_linking_constraints(Thread* current, InstanceKlass* klass) NOT_CDS_RETURN_(false);
257 static void record_linking_constraint(Symbol* name, InstanceKlass* klass,
258 Handle loader1, Handle loader2) NOT_CDS_RETURN;
259 static bool is_builtin(const InstanceKlass* k) {
260 return (k->shared_classpath_index() != UNREGISTERED_INDEX);
261 }
262 static bool add_unregistered_class(Thread* current, InstanceKlass* k);
263 static InstanceKlass* get_unregistered_class(Symbol* name);
264 static void copy_unregistered_class_size_and_crc32(InstanceKlass* klass);
265
266 static void finish_exclusion_checks();
267
268 static bool should_be_excluded(Klass* k);
269 static bool check_for_exclusion(InstanceKlass* k, DumpTimeClassInfo* info);
270 static void validate_before_archiving(InstanceKlass* k);
271 static bool is_excluded_class(InstanceKlass* k);
272 static void set_excluded(InstanceKlass* k);
273 static void set_excluded_locked(InstanceKlass* k);
274 static void set_from_class_file_load_hook(InstanceKlass* k) NOT_CDS_RETURN;
275 static bool warn_excluded(InstanceKlass* k, const char* reason);
276 static void dumptime_classes_do(class MetaspaceClosure* it);
277 static void write_to_archive(bool is_static_archive = true);
278 static void serialize_dictionary_headers(class SerializeClosure* soc,
279 bool is_static_archive = true);
280 static void serialize_vm_classes(class SerializeClosure* soc);
281 static const char* loader_type_for_shared_class(Klass* k);
282 static void get_all_archived_classes(bool is_static_archive, GrowableArray<Klass*>* classes);
283 static void print() { return print_on(tty); }
284 static void print_on(outputStream* st) NOT_CDS_RETURN;
285 static void print_shared_archive(outputStream* st, bool is_static = true) NOT_CDS_RETURN;
286 static void print_table_statistics(outputStream* st) NOT_CDS_RETURN;
287 static bool is_dumptime_table_empty() NOT_CDS_RETURN_(true);
288 DEBUG_ONLY(static bool class_loading_may_happen() {return _class_loading_may_happen;})
289
290 #ifdef ASSERT
291 // This object marks a critical period when writing the CDS archive. During this
292 // period, the JVM must not load any new classes, so as to avoid adding new
293 // items in the SystemDictionaryShared::_dumptime_table.
294 class NoClassLoadingMark: public StackObj {
295 public:
296 NoClassLoadingMark() {
297 assert(_class_loading_may_happen, "must not be nested");
298 _class_loading_may_happen = false;
299 }
300 ~NoClassLoadingMark() {
301 _class_loading_may_happen = true;
302 }
303 };
304 #endif
305
306 template <typename T>
307 static unsigned int hash_for_shared_dictionary_quick(T* ptr) {
308 assert(MetaspaceObj::in_aot_cache((const MetaspaceObj*)ptr), "must be");
309 assert(ptr > (T*)SharedBaseAddress, "must be");
310 uintx offset = uintx(ptr) - uintx(SharedBaseAddress);
311 return primitive_hash<uintx>(offset);
312 }
313
314 static unsigned int hash_for_shared_dictionary(address ptr);
315 static void create_loader_positive_lookup_cache(TRAPS);
316 };
317
318 #endif // SHARE_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP