1 /*
2 * Copyright (c) 2014, 2020, 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 "oops/klass.hpp"
29 #include "classfile/dictionary.hpp"
30 #include "classfile/packageEntry.hpp"
31 #include "classfile/systemDictionary.hpp"
32 #include "memory/filemap.hpp"
33
34
35 /*===============================================================================
36
37 Handling of the classes in the AppCDS archive
38
39 To ensure safety and to simplify the implementation, archived classes are
40 "segregated" into 2 types. The following rules describe how they
41 are stored and looked up.
42
43 [1] Category of archived classes
44
45 There are 2 disjoint groups of classes stored in the AppCDS archive:
46
47 BUILTIN: These classes may be defined ONLY by the BOOT/PLATFORM/APP
48 loaders.
49
50 UNREGISTERED: These classes may be defined ONLY by a ClassLoader
51 instance that's not listed above (using fingerprint matching)
52
53 [2] How classes from different categories are specified in the classlist:
54
55 Starting from JDK9, each class in the classlist may be specified with
56 these keywords: "id", "super", "interfaces", "loader" and "source".
57
58
59 BUILTIN Only the "id" keyword may be (optionally) specified. All other
60 keywords are forbidden.
61
62 The named class is looked up from the jimage and from
63 Xbootclasspath/a and CLASSPATH.
64
65 UNREGISTERED: The "id", "super", and "source" keywords must all be
66 specified.
67
68 The "interfaces" keyword must be specified if the class implements
69 one or more local interfaces. The "interfaces" keyword must not be
70 specified if the class does not implement local interfaces.
71
72 The named class is looked up from the location specified in the
73 "source" keyword.
74
75 Example classlist:
76
77 # BUILTIN
78 java/lang/Object id: 0
79 java/lang/Cloneable id: 1
80 java/lang/String
81
82 # UNREGISTERED
83 Bar id: 3 super: 0 interfaces: 1 source: /foo.jar
84
85
86 [3] Identifying the category of archived classes
87
88 BUILTIN: (C->shared_classpath_index() >= 0)
89 UNREGISTERED: (C->shared_classpath_index() == UNREGISTERED_INDEX (-9999))
90
91 [4] Lookup of archived classes at run time:
92
93 (a) BUILTIN loaders:
94
95 search _builtin_dictionary
96
97 (b) UNREGISTERED loaders:
98
99 search _unregistered_dictionary for an entry that matches the
100 (name, clsfile_len, clsfile_crc32).
101
102 ===============================================================================*/
103 #define UNREGISTERED_INDEX -9999
104
105 class ClassFileStream;
106 class DumpTimeSharedClassInfo;
107 class DumpTimeSharedClassTable;
108 class RunTimeSharedClassInfo;
109 class RunTimeSharedDictionary;
110
111 class SystemDictionaryShared: public SystemDictionary {
112 friend class ExcludeDumpTimeSharedClasses;
113 public:
114 enum {
115 FROM_FIELD_IS_PROTECTED = 1 << 0,
116 FROM_IS_ARRAY = 1 << 1,
117 FROM_IS_OBJECT = 1 << 2
118 };
119
120 private:
121 // These _shared_xxxs arrays are used to initialize the java.lang.Package and
122 // java.security.ProtectionDomain objects associated with each shared class.
123 //
124 // See SystemDictionaryShared::init_security_info for more info.
125 static objArrayOop _shared_protection_domains;
126 static objArrayOop _shared_jar_urls;
127 static objArrayOop _shared_jar_manifests;
128
129 static InstanceKlass* load_shared_class_for_builtin_loader(
130 Symbol* class_name,
131 Handle class_loader,
132 TRAPS);
133 static Handle get_package_name(Symbol* class_name, TRAPS);
134
135 static PackageEntry* get_package_entry_from_class_name(Handle class_loader, Symbol* class_name);
136
137
138 // Package handling:
139 //
140 // 1. For named modules in the runtime image
141 // BOOT classes: Reuses the existing JVM_GetSystemPackage(s) interfaces
142 // to get packages in named modules for shared classes.
143 // Package for non-shared classes in named module is also
144 // handled using JVM_GetSystemPackage(s).
145 //
146 // APP classes: VM calls ClassLoaders.AppClassLoader::definePackage(String, Module)
147 // to define package for shared app classes from named
148 // modules.
149 //
150 // PLATFORM classes: VM calls ClassLoaders.PlatformClassLoader::definePackage(String, Module)
151 // to define package for shared platform classes from named
152 // modules.
153 //
154 // 2. For unnamed modules
155 // BOOT classes: Reuses the existing JVM_GetSystemPackage(s) interfaces to
156 // get packages for shared boot classes in unnamed modules.
157 //
158 // APP classes: VM calls ClassLoaders.AppClassLoader::defineOrCheckPackage()
159 // with with the manifest and url from archived data.
160 //
161 // PLATFORM classes: No package is defined.
162 //
163 // The following two define_shared_package() functions are used to define
164 // package for shared APP and PLATFORM classes.
165 static void define_shared_package(Symbol* class_name,
166 Handle class_loader,
167 Handle manifest,
168 Handle url,
169 TRAPS);
170 static void define_shared_package(Symbol* class_name,
171 Handle class_loader,
172 ModuleEntry* mod_entry,
173 TRAPS);
174
175 static Handle get_shared_jar_manifest(int shared_path_index, TRAPS);
176 static Handle get_shared_jar_url(int shared_path_index, TRAPS);
177 static Handle get_protection_domain_from_classloader(Handle class_loader,
178 Handle url, TRAPS);
179 static Handle get_shared_protection_domain(Handle class_loader,
180 int shared_path_index,
181 Handle url,
182 TRAPS);
183 static Handle get_shared_protection_domain(Handle class_loader,
184 ModuleEntry* mod, TRAPS);
185 static Handle init_security_info(Handle class_loader, InstanceKlass* ik, PackageEntry* pkg_entry, TRAPS);
186
187 static void atomic_set_array_index(objArrayOop array, int index, oop o) {
188 // Benign race condition: array.obj_at(index) may already be filled in.
189 // The important thing here is that all threads pick up the same result.
190 // It doesn't matter which racing thread wins, as long as only one
191 // result is used by all threads, and all future queries.
192 array->atomic_compare_exchange_oop(index, o, NULL);
193 }
194
195 static oop shared_protection_domain(int index);
196 static void atomic_set_shared_protection_domain(int index, oop pd) {
197 atomic_set_array_index(_shared_protection_domains, index, pd);
198 }
199 static void allocate_shared_protection_domain_array(int size, TRAPS);
200 static oop shared_jar_url(int index);
201 static void atomic_set_shared_jar_url(int index, oop url) {
202 atomic_set_array_index(_shared_jar_urls, index, url);
203 }
204 static void allocate_shared_jar_url_array(int size, TRAPS);
205 static oop shared_jar_manifest(int index);
206 static void atomic_set_shared_jar_manifest(int index, oop man) {
207 atomic_set_array_index(_shared_jar_manifests, index, man);
208 }
209 static void allocate_shared_jar_manifest_array(int size, TRAPS);
210 static InstanceKlass* acquire_class_for_current_thread(
211 InstanceKlass *ik,
212 Handle class_loader,
213 Handle protection_domain,
214 const ClassFileStream* cfs,
215 TRAPS);
216 static DumpTimeSharedClassInfo* find_or_allocate_info_for(InstanceKlass* k);
217 static void write_dictionary(RunTimeSharedDictionary* dictionary,
218 bool is_builtin,
219 bool is_static_archive = true);
220 static bool is_jfr_event_class(InstanceKlass *k);
221 static void warn_excluded(InstanceKlass* k, const char* reason);
222 static bool should_be_excluded(InstanceKlass* k);
223
224 DEBUG_ONLY(static bool _no_class_loading_should_happen;)
225 static void update_archived_mirror_native_pointers(RunTimeSharedDictionary* dict);
226
227 public:
228 static InstanceKlass* find_builtin_class(Symbol* class_name);
229
230 static const RunTimeSharedClassInfo* find_record(RunTimeSharedDictionary* static_dict,
231 RunTimeSharedDictionary* dynamic_dict,
232 Symbol* name);
233
234 static bool has_platform_or_app_classes();
235
236 // Called by PLATFORM/APP loader only
237 static InstanceKlass* find_or_load_shared_class(Symbol* class_name,
238 Handle class_loader,
239 TRAPS);
240
241
242 static void allocate_shared_data_arrays(int size, TRAPS);
243 static void oops_do(OopClosure* f);
244
245 // Check if sharing is supported for the class loader.
246 static bool is_sharing_possible(ClassLoaderData* loader_data);
247 static bool is_shared_class_visible_for_classloader(InstanceKlass* ik,
248 Handle class_loader,
249 Symbol* pkg_name,
250 PackageEntry* pkg_entry,
251 ModuleEntry* mod_entry,
252 TRAPS);
253
254 static bool add_unregistered_class(InstanceKlass* k, TRAPS);
255 static InstanceKlass* dump_time_resolve_super_or_fail(Symbol* child_name,
256 Symbol* class_name,
257 Handle class_loader,
258 Handle protection_domain,
259 bool is_superclass,
260 TRAPS);
261
262 static void init_dumptime_info(InstanceKlass* k) NOT_CDS_RETURN;
263 static void remove_dumptime_info(InstanceKlass* k) NOT_CDS_RETURN;
264
265 static Dictionary* boot_loader_dictionary() {
266 return ClassLoaderData::the_null_class_loader_data()->dictionary();
267 }
268
269 static void update_shared_entry(InstanceKlass* klass, int id);
270 static void set_shared_class_misc_info(InstanceKlass* k, ClassFileStream* cfs);
271
272 static InstanceKlass* lookup_from_stream(Symbol* class_name,
273 Handle class_loader,
274 Handle protection_domain,
275 const ClassFileStream* st,
276 TRAPS);
277 // "verification_constraints" are a set of checks performed by
278 // VerificationType::is_reference_assignable_from when verifying a shared class during
279 // dump time.
280 //
281 // With AppCDS, it is possible to override archived classes by calling
282 // ClassLoader.defineClass() directly. SystemDictionary::load_shared_class() already
283 // ensures that you cannot load a shared class if its super type(s) are changed. However,
284 // we need an additional check to ensure that the verification_constraints did not change
285 // between dump time and runtime.
286 static bool add_verification_constraint(InstanceKlass* k, Symbol* name,
287 Symbol* from_name, bool from_field_is_protected,
288 bool from_is_array, bool from_is_object) NOT_CDS_RETURN_(false);
289 static void check_verification_constraints(InstanceKlass* klass,
290 TRAPS) NOT_CDS_RETURN;
291 static void set_class_has_failed_verification(InstanceKlass* ik) NOT_CDS_RETURN;
292 static bool has_class_failed_verification(InstanceKlass* ik) NOT_CDS_RETURN_(false);
293 static bool is_builtin(InstanceKlass* k) {
294 return (k->shared_classpath_index() != UNREGISTERED_INDEX);
295 }
296 static void check_excluded_classes();
297 static void validate_before_archiving(InstanceKlass* k);
298 static bool is_excluded_class(InstanceKlass* k);
299 static void dumptime_classes_do(class MetaspaceClosure* it);
300 static size_t estimate_size_for_archive();
301 static void write_to_archive(bool is_static_archive = true);
302 static void serialize_dictionary_headers(class SerializeClosure* soc,
303 bool is_static_archive = true);
304 static void serialize_well_known_klasses(class SerializeClosure* soc);
305 static void print() { return print_on(tty); }
306 static void print_on(outputStream* st) NOT_CDS_RETURN;
307 static void print_table_statistics(outputStream* st) NOT_CDS_RETURN;
308 static bool empty_dumptime_table() NOT_CDS_RETURN_(true);
309
310 DEBUG_ONLY(static bool no_class_loading_should_happen() {return _no_class_loading_should_happen;})
311
312 #ifdef ASSERT
313 class NoClassLoadingMark: public StackObj {
314 public:
315 NoClassLoadingMark() {
316 assert(!_no_class_loading_should_happen, "must not be nested");
317 _no_class_loading_should_happen = true;
318 }
319 ~NoClassLoadingMark() {
320 _no_class_loading_should_happen = false;
321 }
322 };
323 #endif
324
325 template <typename T>
326 static unsigned int hash_for_shared_dictionary(T* ptr) {
327 assert(ptr > (T*)SharedBaseAddress, "must be");
328 address p = address(ptr) - SharedBaseAddress;
329 return primitive_hash<address>(p);
330 }
331
332 static void update_archived_mirror_native_pointers() NOT_CDS_RETURN;
333 };
334
335 #endif // SHARE_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP