1 /*
2 * Copyright (c) 2003, 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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24
25 #ifndef SHARE_CLASSFILE_DICTIONARY_HPP
26 #define SHARE_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 "oops/oopHandle.hpp"
33 #include "utilities/hashtable.hpp"
34 #include "utilities/ostream.hpp"
35
36 class DictionaryEntry;
37 class BoolObjectClosure;
38
39 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
40 // The data structure for the class loader data dictionaries.
41
42 class Dictionary : public Hashtable<InstanceKlass*, mtClass> {
43 friend class VMStructs;
44
45 static bool _some_dictionary_needs_resizing;
46 bool _resizable;
47 bool _needs_resizing;
48 void check_if_needs_resize();
49
50 ClassLoaderData* _loader_data; // backpointer to owning loader
51 ClassLoaderData* loader_data() const { return _loader_data; }
52
53 DictionaryEntry* get_entry(int index, unsigned int hash, Symbol* name);
54
55 public:
56 Dictionary(ClassLoaderData* loader_data, int table_size, bool resizable = false);
57 Dictionary(ClassLoaderData* loader_data, int table_size, HashtableBucket<mtClass>* t, int number_of_entries, bool resizable = false);
58 ~Dictionary();
59
60 static bool does_any_dictionary_needs_resizing();
61 bool resize_if_needed();
62
63 void add_klass(unsigned int hash, Symbol* class_name, InstanceKlass* obj);
64
65 InstanceKlass* find_class(int index, unsigned int hash, Symbol* name);
66
67 void classes_do(void f(InstanceKlass*));
68 void classes_do(void f(InstanceKlass*, TRAPS), TRAPS);
69 void all_entries_do(KlassClosure* closure);
70 void classes_do(MetaspaceClosure* it);
71
72 void clean_cached_protection_domains();
73
74 // Protection domains
75 InstanceKlass* find(unsigned int hash, Symbol* name, Handle protection_domain);
76 bool is_valid_protection_domain(unsigned int hash,
77 Symbol* name,
78 Handle protection_domain);
79 void add_protection_domain(int index, unsigned int hash,
80 InstanceKlass* klass,
81 Handle protection_domain, TRAPS);
82
83 void print_on(outputStream* st) const;
84 void verify();
85
86 private:
87 DictionaryEntry* new_entry(unsigned int hash, InstanceKlass* klass);
88
89 DictionaryEntry* bucket(int i) const {
90 return (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i);
91 }
92
93 // The following method is not MT-safe and must be done under lock.
94 DictionaryEntry** bucket_addr(int i) {
95 return (DictionaryEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i);
96 }
97
98 void add_entry(int index, DictionaryEntry* new_entry) {
99 Hashtable<InstanceKlass*, mtClass>::add_entry(index, (HashtableEntry<InstanceKlass*, mtClass>*)new_entry);
100 }
101
102 void unlink_entry(DictionaryEntry* entry) {
103 Hashtable<InstanceKlass*, mtClass>::unlink_entry((HashtableEntry<InstanceKlass*, mtClass>*)entry);
104 }
105
106 void free_entry(DictionaryEntry* entry);
107 };
108
109 // An entry in the class loader data dictionaries, this describes a class as
110 // { InstanceKlass*, protection_domain }.
111
112 class DictionaryEntry : public HashtableEntry<InstanceKlass*, mtClass> {
113 friend class VMStructs;
114 private:
115 // Contains the set of approved protection domains that can access
116 // this dictionary entry.
117 //
118 // This protection domain set is a set of tuples:
119 //
120 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
121 //
122 // [Note that C.protection_domain(), which is stored in the java.lang.Class
123 // mirror of C, is NOT the same as PD]
124 //
125 // If such an entry (C, ICL, PD) exists in the table, it means that
126 // it is okay for a class Foo to reference C, where
127 //
128 // Foo.protection_domain() == PD, and
129 // Foo's defining class loader == ICL
130 //
131 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
132 // It is essentially a cache to avoid repeated Java up-calls to
133 // ClassLoader.checkPackageAccess().
134 //
135 ProtectionDomainEntry* volatile _pd_set;
136
137 public:
138 // Tells whether a protection is in the approved set.
139 bool contains_protection_domain(oop protection_domain) const;
140 // Adds a protection domain to the approved set.
141 void add_protection_domain(Dictionary* dict, Handle protection_domain);
142
143 InstanceKlass* instance_klass() const { return literal(); }
144 InstanceKlass** klass_addr() { return (InstanceKlass**)literal_addr(); }
145
146 DictionaryEntry* next() const {
147 return (DictionaryEntry*)HashtableEntry<InstanceKlass*, mtClass>::next();
148 }
149
150 DictionaryEntry** next_addr() {
151 return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();
152 }
153
154 ProtectionDomainEntry* pd_set() const { return _pd_set; }
155 void set_pd_set(ProtectionDomainEntry* new_head) { _pd_set = new_head; }
156
157 // Tells whether the initiating class' protection domain can access the klass in this entry
158 bool is_valid_protection_domain(Handle protection_domain) {
159 if (!ProtectionDomainVerification) return true;
160
161 return protection_domain() == NULL
162 ? true
163 : contains_protection_domain(protection_domain());
164 }
165
166 void verify_protection_domain_set();
167
168 bool equals(const Symbol* class_name) const {
169 InstanceKlass* klass = (InstanceKlass*)literal();
170 return (klass->name() == class_name);
171 }
172
173 void print_count(outputStream *st);
174 void verify();
175 };
176
177 // Entry in a SymbolPropertyTable, mapping a single Symbol*
178 // to a managed and an unmanaged pointer.
179 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
180 friend class VMStructs;
181 private:
182 intptr_t _symbol_mode; // secondary key
183 Method* _method;
184 OopHandle _method_type;
185
186 public:
187 Symbol* symbol() const { return literal(); }
188
189 intptr_t symbol_mode() const { return _symbol_mode; }
190 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
191
192 Method* method() const { return _method; }
193 void set_method(Method* p) { _method = p; }
194
195 oop method_type() const;
196 void set_method_type(oop p);
197
198 // We need to clear the OopHandle because these hashtable entries are not constructed properly.
199 void clear_method_type() { _method_type = OopHandle(); }
200
201 void free_entry();
202
203 SymbolPropertyEntry* next() const {
204 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
205 }
206
207 SymbolPropertyEntry** next_addr() {
208 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
209 }
210
211 void print_entry(outputStream* st) const {
212 symbol()->print_value_on(st);
213 st->print("/mode=" INTX_FORMAT, symbol_mode());
214 st->print(" -> ");
215 bool printed = false;
216 if (method() != NULL) {
217 method()->print_value_on(st);
218 printed = true;
219 }
220 if (method_type() != NULL) {
221 if (printed) st->print(" and ");
222 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
223 printed = true;
224 }
225 st->print_cr(printed ? "" : "(empty)");
226 }
227 };
228
229 // A system-internal mapping of symbols to pointers, both managed
230 // and unmanaged. Used to record the auto-generation of each method
231 // MethodHandle.invoke(S)T, for all signatures (S)T.
232 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
233 friend class VMStructs;
234 private:
235 // The following method is not MT-safe and must be done under lock.
236 SymbolPropertyEntry** bucket_addr(int i) {
237 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
238 }
239
240 void add_entry(int index, SymbolPropertyEntry* new_entry) {
241 ShouldNotReachHere();
242 }
243 void set_entry(int index, SymbolPropertyEntry* new_entry) {
244 ShouldNotReachHere();
245 }
246
247 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
248 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
249 // Hashtable with Symbol* literal must increment and decrement refcount.
250 symbol->increment_refcount();
251 entry->set_symbol_mode(symbol_mode);
252 entry->set_method(NULL);
253 entry->clear_method_type();
254 return entry;
255 }
256
257 public:
258 SymbolPropertyTable(int table_size);
259 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
260
261 void free_entry(SymbolPropertyEntry* entry);
262
263 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
264 // Use the regular identity_hash.
265 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
266 }
267
268 int index_for(Symbol* name, intptr_t symbol_mode) {
269 return hash_to_index(compute_hash(name, symbol_mode));
270 }
271
272 // need not be locked; no state change
273 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
274
275 // must be done under SystemDictionary_lock
276 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
277
278 void methods_do(void f(Method*));
279
280 void verify();
281
282 SymbolPropertyEntry* bucket(int i) {
283 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
284 }
285 };
286 #endif // SHARE_CLASSFILE_DICTIONARY_HPP