1 /*
2 * Copyright (c) 2003, 2017, 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_VM_CLASSFILE_DICTIONARY_HPP
26 #define SHARE_VM_CLASSFILE_DICTIONARY_HPP
27
28 #include "classfile/protectionDomainCache.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "oops/instanceKlass.hpp"
31 #include "oops/oop.hpp"
32 #include "utilities/hashtable.hpp"
33 #include "utilities/ostream.hpp"
34
35 class DictionaryEntry;
36 class BoolObjectClosure;
37
38 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
39 // The data structure for the class loader data dictionaries (and the shared system
40 // dictionary).
41
42 class Dictionary : public Hashtable<InstanceKlass*, mtClass> {
43 friend class VMStructs;
44
45 ClassLoaderData* _loader_data; // backpointer to owning loader
46 ClassLoaderData* loader_data() const { return _loader_data; }
47
48 DictionaryEntry* get_entry(int index, unsigned int hash, Symbol* name);
49
50 protected:
51 DictionaryEntry* bucket(int i) const {
52 return (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i);
53 }
54
55 // The following method is not MT-safe and must be done under lock.
56 DictionaryEntry** bucket_addr(int i) {
57 return (DictionaryEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i);
58 }
59
60 void add_entry(int index, DictionaryEntry* new_entry) {
61 Hashtable<InstanceKlass*, mtClass>::add_entry(index, (HashtableEntry<InstanceKlass*, mtClass>*)new_entry);
62 }
63
64 void free_entry(DictionaryEntry* entry);
65
66 static size_t entry_size();
67 public:
68 Dictionary(ClassLoaderData* loader_data, int table_size);
69 Dictionary(ClassLoaderData* loader_data, int table_size, HashtableBucket<mtClass>* t, int number_of_entries);
70 ~Dictionary();
71
72 DictionaryEntry* new_entry(unsigned int hash, InstanceKlass* klass);
73
74 void add_klass(int index, unsigned int hash, Symbol* class_name, InstanceKlass* obj);
75
76 InstanceKlass* find_class(int index, unsigned int hash, Symbol* name);
77
78 InstanceKlass* find_shared_class(int index, unsigned int hash, Symbol* name);
79
80 // GC support
81 void oops_do(OopClosure* f);
82 void roots_oops_do(OopClosure* strong, OopClosure* weak);
83
84 void classes_do(void f(InstanceKlass*));
85 void classes_do(void f(InstanceKlass*, TRAPS), TRAPS);
86 void all_entries_do(void f(InstanceKlass*, ClassLoaderData*));
87 void classes_do(MetaspaceClosure* it);
88
89 void unlink(BoolObjectClosure* is_alive);
90 void remove_classes_in_error_state();
91
92 // Unload classes whose defining loaders are unloaded
93 void do_unloading();
94
95 // Protection domains
96 InstanceKlass* find(int index, unsigned int hash, Symbol* name, Handle protection_domain);
97 bool is_valid_protection_domain(int index, unsigned int hash,
98 Symbol* name,
99 Handle protection_domain);
100 void add_protection_domain(int index, unsigned int hash,
101 InstanceKlass* klass,
102 Handle protection_domain, TRAPS);
103
104 // Sharing support
105 void reorder_dictionary_for_sharing();
106
107 void print_on(outputStream* st) const;
108 void verify();
109 };
110
111 // An entry in the class loader data dictionaries, this describes a class as
112 // { InstanceKlass*, protection_domain }.
113
114 class DictionaryEntry : public HashtableEntry<InstanceKlass*, mtClass> {
115 friend class VMStructs;
116 private:
117 // Contains the set of approved protection domains that can access
118 // this dictionary entry.
119 //
120 // This protection domain set is a set of tuples:
121 //
122 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
123 //
124 // [Note that C.protection_domain(), which is stored in the java.lang.Class
125 // mirror of C, is NOT the same as PD]
126 //
127 // If such an entry (C, ICL, PD) exists in the table, it means that
128 // it is okay for a class Foo to reference C, where
129 //
130 // Foo.protection_domain() == PD, and
131 // Foo's defining class loader == ICL
132 //
133 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
134 // It is essentially a cache to avoid repeated Java up-calls to
135 // ClassLoader.checkPackageAccess().
136 //
137 ProtectionDomainEntry* _pd_set;
138
139 public:
140 // Tells whether a protection is in the approved set.
141 bool contains_protection_domain(oop protection_domain) const;
142 // Adds a protection domain to the approved set.
143 void add_protection_domain(Dictionary* dict, Handle protection_domain);
144
145 InstanceKlass* instance_klass() const { return literal(); }
146 InstanceKlass** klass_addr() { return (InstanceKlass**)literal_addr(); }
147
148 DictionaryEntry* next() const {
149 return (DictionaryEntry*)HashtableEntry<InstanceKlass*, mtClass>::next();
150 }
151
152 DictionaryEntry** next_addr() {
153 return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();
154 }
155
156 ProtectionDomainEntry* pd_set() const { return _pd_set; }
157 void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; }
158
159 // Tells whether the initiating class' protection domain can access the klass in this entry
160 bool is_valid_protection_domain(Handle protection_domain) {
161 if (!ProtectionDomainVerification) return true;
162 if (!SystemDictionary::has_checkPackageAccess()) return true;
163
164 return protection_domain() == NULL
165 ? true
166 : contains_protection_domain(protection_domain());
167 }
168
169 void verify_protection_domain_set() {
170 for (ProtectionDomainEntry* current = _pd_set;
171 current != NULL;
172 current = current->_next) {
173 current->_pd_cache->protection_domain()->verify();
174 }
175 }
176
177 bool equals(const Symbol* class_name) const {
178 InstanceKlass* klass = (InstanceKlass*)literal();
179 return (klass->name() == class_name);
180 }
181
182 void print_count(outputStream *st) {
183 int count = 0;
184 for (ProtectionDomainEntry* current = _pd_set;
185 current != NULL;
186 current = current->_next) {
187 count++;
188 }
189 st->print_cr("pd set count = #%d", count);
190 }
191
192 void verify();
193 };
194
195 // Entry in a SymbolPropertyTable, mapping a single Symbol*
196 // to a managed and an unmanaged pointer.
197 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
198 friend class VMStructs;
199 private:
200 intptr_t _symbol_mode; // secondary key
201 Method* _method;
202 oop _method_type;
203
204 public:
205 Symbol* symbol() const { return literal(); }
206
207 intptr_t symbol_mode() const { return _symbol_mode; }
208 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
209
210 Method* method() const { return _method; }
211 void set_method(Method* p) { _method = p; }
212
213 oop method_type() const { return _method_type; }
214 oop* method_type_addr() { return &_method_type; }
215 void set_method_type(oop p) { _method_type = p; }
216
217 SymbolPropertyEntry* next() const {
218 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
219 }
220
221 SymbolPropertyEntry** next_addr() {
222 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
223 }
224
225 void print_entry(outputStream* st) const {
226 symbol()->print_value_on(st);
227 st->print("/mode=" INTX_FORMAT, symbol_mode());
228 st->print(" -> ");
229 bool printed = false;
230 if (method() != NULL) {
231 method()->print_value_on(st);
232 printed = true;
233 }
234 if (method_type() != NULL) {
235 if (printed) st->print(" and ");
236 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
237 printed = true;
238 }
239 st->print_cr(printed ? "" : "(empty)");
240 }
241 };
242
243 // A system-internal mapping of symbols to pointers, both managed
244 // and unmanaged. Used to record the auto-generation of each method
245 // MethodHandle.invoke(S)T, for all signatures (S)T.
246 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
247 friend class VMStructs;
248 private:
249 SymbolPropertyEntry* bucket(int i) {
250 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
251 }
252
253 // The following method is not MT-safe and must be done under lock.
254 SymbolPropertyEntry** bucket_addr(int i) {
255 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
256 }
257
258 void add_entry(int index, SymbolPropertyEntry* new_entry) {
259 ShouldNotReachHere();
260 }
261 void set_entry(int index, SymbolPropertyEntry* new_entry) {
262 ShouldNotReachHere();
263 }
264
265 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
266 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
267 // Hashtable with Symbol* literal must increment and decrement refcount.
268 symbol->increment_refcount();
269 entry->set_symbol_mode(symbol_mode);
270 entry->set_method(NULL);
271 entry->set_method_type(NULL);
272 return entry;
273 }
274
275 public:
276 SymbolPropertyTable(int table_size);
277 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
278
279 void free_entry(SymbolPropertyEntry* entry) {
280 // decrement Symbol refcount here because hashtable doesn't.
281 entry->literal()->decrement_refcount();
282 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
283 }
284
285 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
286 // Use the regular identity_hash.
287 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
288 }
289
290 int index_for(Symbol* name, intptr_t symbol_mode) {
291 return hash_to_index(compute_hash(name, symbol_mode));
292 }
293
294 // need not be locked; no state change
295 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
296
297 // must be done under SystemDictionary_lock
298 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
299
300 // GC support
301 void oops_do(OopClosure* f);
302
303 void methods_do(void f(Method*));
304
305 void verify();
306 };
307 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP