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.
22 *
23 */
24
25 #ifndef SHARE_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP
26 #define SHARE_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP
27
28 #include "cds/cds_globals.hpp"
29 #include "cds/filemap.hpp"
30 #include "cds/dumpTimeClassInfo.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
38
39 /*===============================================================================
40
41 Handling of the classes in the AppCDS archive
42
43 To ensure safety and to simplify the implementation, archived classes are
44 "segregated" into 2 types. The following rules describe how they
45 are stored and looked up.
46
47 [1] Category of archived classes
48
49 There are 2 disjoint groups of classes stored in the AppCDS archive:
50
51 BUILTIN: These classes may be defined ONLY by the BOOT/PLATFORM/APP
52 loaders.
53
54 UNREGISTERED: These classes may be defined ONLY by a ClassLoader
55 instance that's not listed above (using fingerprint matching)
56
57 [2] How classes from different categories are specified in the classlist:
58
59 Starting from JDK9, each class in the classlist may be specified with
60 these keywords: "id", "super", "interfaces", "loader" and "source".
61
62
63 BUILTIN Only the "id" keyword may be (optionally) specified. All other
64 keywords are forbidden.
65
66 The named class is looked up from the jimage and from
67 Xbootclasspath/a and CLASSPATH.
68
69 UNREGISTERED: The "id", "super", and "source" keywords must all be
70 specified.
71
72 The "interfaces" keyword must be specified if the class implements
73 one or more local interfaces. The "interfaces" keyword must not be
74 specified if the class does not implement local interfaces.
75
76 The named class is looked up from the location specified in the
77 "source" keyword.
78
79 Example classlist:
80
81 # BUILTIN
82 java/lang/Object id: 0
83 java/lang/Cloneable id: 1
84 java/lang/String
85
86 # UNREGISTERED
87 Bar id: 3 super: 0 interfaces: 1 source: /foo.jar
88
89
90 [3] Identifying the category of archived classes
91
92 BUILTIN: (C->shared_classpath_index() >= 0)
93 UNREGISTERED: (C->shared_classpath_index() == UNREGISTERED_INDEX (-9999))
94
95 [4] Lookup of archived classes at run time:
96
97 (a) BUILTIN loaders:
98
99 search _builtin_dictionary
100
101 (b) UNREGISTERED loaders:
102
103 search _unregistered_dictionary for an entry that matches the
104 (name, clsfile_len, clsfile_crc32).
105
106 ===============================================================================*/
107 #define UNREGISTERED_INDEX -9999
108
109 class BootstrapInfo;
110 class ClassFileStream;
111 class ConstantPoolCache;
112 class Dictionary;
113 class DumpTimeClassInfo;
114 class DumpTimeSharedClassTable;
115 class RunTimeClassInfo;
116 class RunTimeSharedDictionary;
117
118 class SharedClassLoadingMark {
119 private:
120 Thread* THREAD;
121 InstanceKlass* _klass;
122 public:
123 SharedClassLoadingMark(Thread* current, InstanceKlass* ik) : THREAD(current), _klass(ik) {}
124 ~SharedClassLoadingMark() {
125 assert(THREAD != nullptr, "Current thread is nullptr");
126 assert(_klass != nullptr, "InstanceKlass is nullptr");
127 if (HAS_PENDING_EXCEPTION) {
128 if (_klass->is_shared()) {
129 _klass->set_shared_loading_failed();
130 }
131 }
132 }
133 };
134
135 class SystemDictionaryShared: public SystemDictionary {
136 friend class LambdaProxyClassDictionary;
137
138 struct ArchiveInfo {
139 RunTimeSharedDictionary _builtin_dictionary;
140 RunTimeSharedDictionary _unregistered_dictionary;
141
142 void print_on(const char* prefix, outputStream* st, bool is_static_archive);
143 void print_table_statistics(const char* prefix, outputStream* st, bool is_static_archive);
144 };
145
146 private:
147
148 static DumpTimeSharedClassTable* _dumptime_table;
149
150 static ArchiveInfo _static_archive;
151 static ArchiveInfo _dynamic_archive;
152
153 static ArchiveInfo* get_archive(bool is_static_archive) {
154 return is_static_archive ? &_static_archive : &_dynamic_archive;
155 }
156
157 static InstanceKlass* load_shared_class_for_builtin_loader(
158 Symbol* class_name,
159 Handle class_loader,
160 TRAPS);
161 static InstanceKlass* acquire_class_for_current_thread(
162 InstanceKlass *ik,
163 Handle class_loader,
164 Handle protection_domain,
165 const ClassFileStream* cfs,
166 TRAPS);
167
168 // Guaranteed to return non-null value for non-shared classes.
169 // k must not be a shared class.
170 static DumpTimeClassInfo* get_info(InstanceKlass* k);
171 static DumpTimeClassInfo* get_info_locked(InstanceKlass* k);
172
173 static void write_dictionary(RunTimeSharedDictionary* dictionary,
174 bool is_builtin);
175 static bool is_jfr_event_class(InstanceKlass *k);
176 static bool check_for_exclusion_impl(InstanceKlass* k);
177 static void remove_dumptime_info(InstanceKlass* k) NOT_CDS_RETURN;
178 static bool has_been_redefined(InstanceKlass* k);
179 DEBUG_ONLY(static bool _class_loading_may_happen;)
180
181 static void copy_verification_constraints_from_preimage(InstanceKlass* klass);
182 static void copy_linking_constraints_from_preimage(InstanceKlass* klass);
183
184 public:
185 static bool is_early_klass(InstanceKlass* k); // Was k loaded while JvmtiExport::is_early_phase()==true
186 static bool has_archived_enum_objs(InstanceKlass* ik);
187 static void set_has_archived_enum_objs(InstanceKlass* ik);
188
189 static InstanceKlass* find_builtin_class(Symbol* class_name);
190
191 static const RunTimeClassInfo* find_record(RunTimeSharedDictionary* static_dict,
192 RunTimeSharedDictionary* dynamic_dict,
193 Symbol* name);
194
195 static bool has_platform_or_app_classes();
196
197 // Called by PLATFORM/APP loader only
198 static InstanceKlass* find_or_load_shared_class(Symbol* class_name,
199 Handle class_loader,
200 TRAPS);
201
202
203 static void allocate_shared_data_arrays(int size, TRAPS);
204
205 static bool is_builtin_loader(ClassLoaderData* loader_data);
206
207 static InstanceKlass* lookup_super_for_unregistered_class(Symbol* class_name,
208 Symbol* super_name, bool is_superclass);
209
210 static void initialize() NOT_CDS_RETURN;
211 static void init_dumptime_info(InstanceKlass* k) NOT_CDS_RETURN;
212 static void init_dumptime_info_from_preimage(InstanceKlass* k) NOT_CDS_RETURN;
213 static void handle_class_unloading(InstanceKlass* k) NOT_CDS_RETURN;
214
215 static Dictionary* boot_loader_dictionary() {
216 return ClassLoaderData::the_null_class_loader_data()->dictionary();
217 }
218
219 static void update_shared_entry(InstanceKlass* klass, int id);
220 static void set_shared_class_misc_info(InstanceKlass* k, ClassFileStream* cfs);
221
222 static InstanceKlass* lookup_from_stream(Symbol* class_name,
223 Handle class_loader,
224 Handle protection_domain,
225 const ClassFileStream* st,
226 TRAPS);
227 // "verification_constraints" are a set of checks performed by
228 // VerificationType::is_reference_assignable_from when verifying a shared class during
229 // dump time.
230 //
231 // With AppCDS, it is possible to override archived classes by calling
232 // ClassLoader.defineClass() directly. SystemDictionary::load_shared_class() already
233 // ensures that you cannot load a shared class if its super type(s) are changed. However,
234 // we need an additional check to ensure that the verification_constraints did not change
235 // between dump time and runtime.
236 static bool add_verification_constraint(InstanceKlass* k, Symbol* name,
237 Symbol* from_name, bool from_field_is_protected,
238 bool from_is_array, bool from_is_object) NOT_CDS_RETURN_(false);
239 static void check_verification_constraints(InstanceKlass* klass,
240 TRAPS) NOT_CDS_RETURN;
241 static void add_enum_klass_static_field(InstanceKlass* ik, int root_index);
242 static void set_class_has_failed_verification(InstanceKlass* ik) NOT_CDS_RETURN;
243 static bool has_class_failed_verification(InstanceKlass* ik) NOT_CDS_RETURN_(false);
244 static bool check_linking_constraints(Thread* current, InstanceKlass* klass) NOT_CDS_RETURN_(false);
245 static void record_linking_constraint(Symbol* name, InstanceKlass* klass,
246 Handle loader1, Handle loader2) NOT_CDS_RETURN;
247 static bool is_builtin(const InstanceKlass* k) {
248 return (k->shared_classpath_index() != UNREGISTERED_INDEX);
249 }
250 static bool add_unregistered_class(Thread* current, InstanceKlass* k);
251 static void copy_unregistered_class_size_and_crc32(InstanceKlass* klass);
252
253 static void finish_exclusion_checks();
254 static DumpTimeSharedClassTable* dumptime_table() { return _dumptime_table; }
255
256 static bool should_be_excluded(Klass* k);
257 static bool check_for_exclusion(InstanceKlass* k, DumpTimeClassInfo* info);
258 static void validate_before_archiving(InstanceKlass* k);
259 static bool is_excluded_class(InstanceKlass* k);
260 static void set_excluded(InstanceKlass* k);
261 static void set_excluded_locked(InstanceKlass* k);
262 static bool warn_excluded(InstanceKlass* k, const char* reason);
263 static void dumptime_classes_do(class MetaspaceClosure* it);
264 static void write_to_archive(bool is_static_archive = true);
265 static void serialize_dictionary_headers(class SerializeClosure* soc,
266 bool is_static_archive = true);
267 static void serialize_vm_classes(class SerializeClosure* soc);
268 static const char* loader_type_for_shared_class(Klass* k);
269 static void print() { return print_on(tty); }
270 static void print_on(outputStream* st) NOT_CDS_RETURN;
271 static void print_shared_archive(outputStream* st, bool is_static = true) NOT_CDS_RETURN;
272 static void print_table_statistics(outputStream* st) NOT_CDS_RETURN;
273 static bool is_dumptime_table_empty() NOT_CDS_RETURN_(true);
274 DEBUG_ONLY(static bool class_loading_may_happen() {return _class_loading_may_happen;})
275
276 #ifdef ASSERT
277 // This object marks a critical period when writing the CDS archive. During this
278 // period, the JVM must not load any new classes, so as to avoid adding new
279 // items in the SystemDictionaryShared::_dumptime_table.
280 class NoClassLoadingMark: public StackObj {
281 public:
282 NoClassLoadingMark() {
283 assert(_class_loading_may_happen, "must not be nested");
284 _class_loading_may_happen = false;
285 }
286 ~NoClassLoadingMark() {
287 _class_loading_may_happen = true;
288 }
289 };
290 #endif
291
292 template <typename T>
293 static unsigned int hash_for_shared_dictionary_quick(T* ptr) {
294 assert(MetaspaceObj::is_shared((const MetaspaceObj*)ptr), "must be");
295 assert(ptr > (T*)SharedBaseAddress, "must be");
296 uintx offset = uintx(ptr) - uintx(SharedBaseAddress);
297 return primitive_hash<uintx>(offset);
298 }
299
300 static unsigned int hash_for_shared_dictionary(address ptr);
301 };
302
303 #endif // SHARE_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP