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 "runtime/orderAccess.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 (and the shared system
41 // dictionary).
42
43 class Dictionary : public Hashtable<InstanceKlass*, mtClass> {
44 friend class VMStructs;
45
46 ClassLoaderData* _loader_data; // backpointer to owning loader
47 ClassLoaderData* loader_data() const { return _loader_data; }
48
49 DictionaryEntry* get_entry(int index, unsigned int hash, Symbol* name);
50
51 protected:
52 DictionaryEntry* bucket(int i) const {
53 return (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i);
54 }
55
56 // The following method is not MT-safe and must be done under lock.
57 DictionaryEntry** bucket_addr(int i) {
58 return (DictionaryEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i);
59 }
60
61 void add_entry(int index, DictionaryEntry* new_entry) {
62 Hashtable<InstanceKlass*, mtClass>::add_entry(index, (HashtableEntry<InstanceKlass*, mtClass>*)new_entry);
63 }
64
65 void free_entry(DictionaryEntry* entry);
66
67 static size_t entry_size();
68 public:
69 Dictionary(ClassLoaderData* loader_data, int table_size);
70 Dictionary(ClassLoaderData* loader_data, int table_size, HashtableBucket<mtClass>* t, int number_of_entries);
71 ~Dictionary();
72
73 DictionaryEntry* new_entry(unsigned int hash, InstanceKlass* klass);
74
75 void add_klass(int index, unsigned int hash, Symbol* class_name, InstanceKlass* obj);
76
77 InstanceKlass* find_class(int index, unsigned int hash, Symbol* name);
78
79 InstanceKlass* find_shared_class(int index, unsigned int hash, Symbol* name);
80
81 // GC support
82 void oops_do(OopClosure* f);
83 void roots_oops_do(OopClosure* strong, OopClosure* weak);
84
85 void classes_do(void f(InstanceKlass*));
86 void classes_do(void f(InstanceKlass*, TRAPS), TRAPS);
87 void all_entries_do(void f(InstanceKlass*, ClassLoaderData*));
88 void classes_do(MetaspaceClosure* it);
89
90 void unlink(BoolObjectClosure* is_alive);
91 void remove_classes_in_error_state();
92
93 // Unload classes whose defining loaders are unloaded
94 void do_unloading();
95
96 // Protection domains
97 InstanceKlass* find(int index, unsigned int hash, Symbol* name, Handle protection_domain);
98 bool is_valid_protection_domain(int index, unsigned int hash,
99 Symbol* name,
100 Handle protection_domain);
101 void add_protection_domain(int index, unsigned int hash,
102 InstanceKlass* klass,
103 Handle protection_domain, TRAPS);
104
105 // Sharing support
106 void reorder_dictionary_for_sharing();
107
108 void print_on(outputStream* st) const;
109 void verify();
110 };
111
112 // An entry in the class loader data dictionaries, this describes a class as
113 // { InstanceKlass*, protection_domain }.
114
115 class DictionaryEntry : public HashtableEntry<InstanceKlass*, mtClass> {
116 friend class VMStructs;
117 private:
118 // Contains the set of approved protection domains that can access
119 // this dictionary entry.
120 //
121 // This protection domain set is a set of tuples:
122 //
123 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
124 //
125 // [Note that C.protection_domain(), which is stored in the java.lang.Class
126 // mirror of C, is NOT the same as PD]
127 //
128 // If such an entry (C, ICL, PD) exists in the table, it means that
129 // it is okay for a class Foo to reference C, where
130 //
131 // Foo.protection_domain() == PD, and
132 // Foo's defining class loader == ICL
133 //
134 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
135 // It is essentially a cache to avoid repeated Java up-calls to
136 // ClassLoader.checkPackageAccess().
137 //
138 ProtectionDomainEntry* volatile _pd_set;
139
140 public:
141 // Tells whether a protection is in the approved set.
142 bool contains_protection_domain(oop protection_domain) const;
143 // Adds a protection domain to the approved set.
144 void add_protection_domain(Dictionary* dict, Handle protection_domain);
145
146 InstanceKlass* instance_klass() const { return literal(); }
147 InstanceKlass** klass_addr() { return (InstanceKlass**)literal_addr(); }
148
149 DictionaryEntry* next() const {
150 return (DictionaryEntry*)HashtableEntry<InstanceKlass*, mtClass>::next();
151 }
152
153 DictionaryEntry** next_addr() {
154 return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();
155 }
156
157 ProtectionDomainEntry* pd_set() const { return _pd_set; }
158 void set_pd_set(ProtectionDomainEntry* new_head) { _pd_set = new_head; }
159
160 ProtectionDomainEntry* pd_set_acquire() const {
161 return (ProtectionDomainEntry*)OrderAccess::load_ptr_acquire(&_pd_set);
162 }
163 void release_set_pd_set(ProtectionDomainEntry* new_head) {
164 OrderAccess::release_store_ptr(&_pd_set, new_head);
165 }
166
167 // Tells whether the initiating class' protection domain can access the klass in this entry
168 bool is_valid_protection_domain(Handle protection_domain) {
169 if (!ProtectionDomainVerification) return true;
170 if (!SystemDictionary::has_checkPackageAccess()) return true;
171
172 return protection_domain() == NULL
173 ? true
174 : contains_protection_domain(protection_domain());
175 }
176
177 void verify_protection_domain_set() {
178 for (ProtectionDomainEntry* current = pd_set();
179 current != NULL;
180 current = current->_next) {
181 current->_pd_cache->protection_domain()->verify();
182 }
183 }
184
185 bool equals(const Symbol* class_name) const {
186 InstanceKlass* klass = (InstanceKlass*)literal();
187 return (klass->name() == class_name);
188 }
189
190 void print_count(outputStream *st) {
191 int count = 0;
192 for (ProtectionDomainEntry* current = pd_set();
193 current != NULL;
194 current = current->_next) {
195 count++;
196 }
197 st->print_cr("pd set count = #%d", count);
198 }
199
200 void verify();
201 };
202
203 // Entry in a SymbolPropertyTable, mapping a single Symbol*
204 // to a managed and an unmanaged pointer.
205 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
206 friend class VMStructs;
207 private:
208 intptr_t _symbol_mode; // secondary key
209 Method* _method;
210 oop _method_type;
211
212 public:
213 Symbol* symbol() const { return literal(); }
214
215 intptr_t symbol_mode() const { return _symbol_mode; }
216 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
217
218 Method* method() const { return _method; }
219 void set_method(Method* p) { _method = p; }
220
221 oop method_type() const { return _method_type; }
222 oop* method_type_addr() { return &_method_type; }
223 void set_method_type(oop p) { _method_type = p; }
224
225 SymbolPropertyEntry* next() const {
226 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
227 }
228
229 SymbolPropertyEntry** next_addr() {
230 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
231 }
232
233 void print_entry(outputStream* st) const {
234 symbol()->print_value_on(st);
235 st->print("/mode=" INTX_FORMAT, symbol_mode());
236 st->print(" -> ");
237 bool printed = false;
238 if (method() != NULL) {
239 method()->print_value_on(st);
240 printed = true;
241 }
242 if (method_type() != NULL) {
243 if (printed) st->print(" and ");
244 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
245 printed = true;
246 }
247 st->print_cr(printed ? "" : "(empty)");
248 }
249 };
250
251 // A system-internal mapping of symbols to pointers, both managed
252 // and unmanaged. Used to record the auto-generation of each method
253 // MethodHandle.invoke(S)T, for all signatures (S)T.
254 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
255 friend class VMStructs;
256 private:
257 SymbolPropertyEntry* bucket(int i) {
258 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
259 }
260
261 // The following method is not MT-safe and must be done under lock.
262 SymbolPropertyEntry** bucket_addr(int i) {
263 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
264 }
265
266 void add_entry(int index, SymbolPropertyEntry* new_entry) {
267 ShouldNotReachHere();
268 }
269 void set_entry(int index, SymbolPropertyEntry* new_entry) {
270 ShouldNotReachHere();
271 }
272
273 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
274 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
275 // Hashtable with Symbol* literal must increment and decrement refcount.
276 symbol->increment_refcount();
277 entry->set_symbol_mode(symbol_mode);
278 entry->set_method(NULL);
279 entry->set_method_type(NULL);
280 return entry;
281 }
282
283 public:
284 SymbolPropertyTable(int table_size);
285 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
286
287 void free_entry(SymbolPropertyEntry* entry) {
288 // decrement Symbol refcount here because hashtable doesn't.
289 entry->literal()->decrement_refcount();
290 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
291 }
292
293 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
294 // Use the regular identity_hash.
295 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
296 }
297
298 int index_for(Symbol* name, intptr_t symbol_mode) {
299 return hash_to_index(compute_hash(name, symbol_mode));
300 }
301
302 // need not be locked; no state change
303 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
304
305 // must be done under SystemDictionary_lock
306 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
307
308 // GC support
309 void oops_do(OopClosure* f);
310
311 void methods_do(void f(Method*));
312
313 void verify();
314 };
315 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP