1 /*
2 * Copyright (c) 2003, 2018, 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 static bool _some_dictionary_needs_resizing;
47 bool _resizable;
48 bool _needs_resizing;
49 void check_if_needs_resize();
50
51 ClassLoaderData* _loader_data; // backpointer to owning loader
52 ClassLoaderData* loader_data() const { return _loader_data; }
53
54 DictionaryEntry* get_entry(int index, unsigned int hash, Symbol* name);
55
56 void clean_cached_protection_domains(BoolObjectClosure* is_alive, DictionaryEntry* probe);
57
58 protected:
59 static size_t entry_size();
60 public:
61 Dictionary(ClassLoaderData* loader_data, int table_size, bool resizable = false);
62 Dictionary(ClassLoaderData* loader_data, int table_size, HashtableBucket<mtClass>* t, int number_of_entries, bool resizable = false);
63 ~Dictionary();
64
65 static bool does_any_dictionary_needs_resizing();
66 bool resize_if_needed();
67
68 DictionaryEntry* new_entry(unsigned int hash, InstanceKlass* klass);
69
70 void add_klass(unsigned int hash, Symbol* class_name, InstanceKlass* obj);
71
72 InstanceKlass* find_class(int index, unsigned int hash, Symbol* name);
73
74 InstanceKlass* find_shared_class(int index, unsigned int hash, Symbol* name);
75
76 // GC support
77 void oops_do(OopClosure* f);
78 void roots_oops_do(OopClosure* strong, OopClosure* weak);
79
80 void classes_do(void f(InstanceKlass*));
81 void classes_do(void f(InstanceKlass*, TRAPS), TRAPS);
82 void all_entries_do(void f(InstanceKlass*, ClassLoaderData*));
83 void classes_do(MetaspaceClosure* it);
84
85 void unlink(BoolObjectClosure* is_alive);
86 void remove_classes_in_error_state();
87
88 // Unload classes whose defining loaders are unloaded
89 void do_unloading(BoolObjectClosure* is_alive);
90
91 // Protection domains
92 InstanceKlass* find(unsigned int hash, Symbol* name, Handle protection_domain);
93 bool is_valid_protection_domain(unsigned int hash,
94 Symbol* name,
95 Handle protection_domain);
96 void add_protection_domain(int index, unsigned int hash,
97 InstanceKlass* klass,
98 Handle protection_domain, TRAPS);
99
100 // Sharing support
101 void reorder_dictionary_for_sharing() NOT_CDS_RETURN;
102
103 void print_on(outputStream* st) const;
104 void verify();
105 DictionaryEntry* bucket(int i) const {
106 return (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i);
107 }
108
109 // The following method is not MT-safe and must be done under lock.
110 DictionaryEntry** bucket_addr(int i) {
111 return (DictionaryEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i);
112 }
113
114 void add_entry(int index, DictionaryEntry* new_entry) {
115 Hashtable<InstanceKlass*, mtClass>::add_entry(index, (HashtableEntry<InstanceKlass*, mtClass>*)new_entry);
116 }
117
118 void unlink_entry(DictionaryEntry* entry) {
119 Hashtable<InstanceKlass*, mtClass>::unlink_entry((HashtableEntry<InstanceKlass*, mtClass>*)entry);
120 }
121
122 void free_entry(DictionaryEntry* entry);
123 };
124
125 // An entry in the class loader data dictionaries, this describes a class as
126 // { InstanceKlass*, protection_domain }.
127
128 class DictionaryEntry : public HashtableEntry<InstanceKlass*, mtClass> {
129 friend class VMStructs;
130 private:
131 // Contains the set of approved protection domains that can access
132 // this dictionary entry.
133 //
134 // This protection domain set is a set of tuples:
135 //
136 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
137 //
138 // [Note that C.protection_domain(), which is stored in the java.lang.Class
139 // mirror of C, is NOT the same as PD]
140 //
141 // If such an entry (C, ICL, PD) exists in the table, it means that
142 // it is okay for a class Foo to reference C, where
143 //
144 // Foo.protection_domain() == PD, and
145 // Foo's defining class loader == ICL
146 //
147 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
148 // It is essentially a cache to avoid repeated Java up-calls to
149 // ClassLoader.checkPackageAccess().
150 //
151 ProtectionDomainEntry* volatile _pd_set;
152
153 public:
154 // Tells whether a protection is in the approved set.
155 bool contains_protection_domain(oop protection_domain) const;
156 // Adds a protection domain to the approved set.
157 void add_protection_domain(Dictionary* dict, Handle protection_domain);
158
159 InstanceKlass* instance_klass() const { return literal(); }
160 InstanceKlass** klass_addr() { return (InstanceKlass**)literal_addr(); }
161
162 DictionaryEntry* next() const {
163 return (DictionaryEntry*)HashtableEntry<InstanceKlass*, mtClass>::next();
164 }
165
166 DictionaryEntry** next_addr() {
167 return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();
168 }
169
170 ProtectionDomainEntry* pd_set() const { return _pd_set; }
171 void set_pd_set(ProtectionDomainEntry* new_head) { _pd_set = new_head; }
172
173 ProtectionDomainEntry* pd_set_acquire() const {
174 return OrderAccess::load_acquire(&_pd_set);
175 }
176 void release_set_pd_set(ProtectionDomainEntry* new_head) {
177 OrderAccess::release_store(&_pd_set, new_head);
178 }
179
180 // Tells whether the initiating class' protection domain can access the klass in this entry
181 bool is_valid_protection_domain(Handle protection_domain) {
182 if (!ProtectionDomainVerification) return true;
183 if (!SystemDictionary::has_checkPackageAccess()) return true;
184
185 return protection_domain() == NULL
186 ? true
187 : contains_protection_domain(protection_domain());
188 }
189
190 void verify_protection_domain_set() {
191 for (ProtectionDomainEntry* current = pd_set(); // accessed at a safepoint
192 current != NULL;
193 current = current->_next) {
194 current->_pd_cache->object_no_keepalive()->verify();
195 }
196 }
197
198 bool equals(const Symbol* class_name) const {
199 InstanceKlass* klass = (InstanceKlass*)literal();
200 return (klass->name() == class_name);
201 }
202
203 void print_count(outputStream *st) {
204 int count = 0;
205 for (ProtectionDomainEntry* current = pd_set(); // accessed inside SD lock
206 current != NULL;
207 current = current->_next) {
208 count++;
209 }
210 st->print_cr("pd set count = #%d", count);
211 }
212
213 void verify();
214 };
215
216 // Entry in a SymbolPropertyTable, mapping a single Symbol*
217 // to a managed and an unmanaged pointer.
218 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
219 friend class VMStructs;
220 private:
221 intptr_t _symbol_mode; // secondary key
222 Method* _method;
223 oop _method_type;
224
225 public:
226 Symbol* symbol() const { return literal(); }
227
228 intptr_t symbol_mode() const { return _symbol_mode; }
229 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
230
231 Method* method() const { return _method; }
232 void set_method(Method* p) { _method = p; }
233
234 oop method_type() const { return _method_type; }
235 oop* method_type_addr() { return &_method_type; }
236 void set_method_type(oop p) { _method_type = p; }
237
238 SymbolPropertyEntry* next() const {
239 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
240 }
241
242 SymbolPropertyEntry** next_addr() {
243 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
244 }
245
246 void print_entry(outputStream* st) const {
247 symbol()->print_value_on(st);
248 st->print("/mode=" INTX_FORMAT, symbol_mode());
249 st->print(" -> ");
250 bool printed = false;
251 if (method() != NULL) {
252 method()->print_value_on(st);
253 printed = true;
254 }
255 if (method_type() != NULL) {
256 if (printed) st->print(" and ");
257 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
258 printed = true;
259 }
260 st->print_cr(printed ? "" : "(empty)");
261 }
262 };
263
264 // A system-internal mapping of symbols to pointers, both managed
265 // and unmanaged. Used to record the auto-generation of each method
266 // MethodHandle.invoke(S)T, for all signatures (S)T.
267 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
268 friend class VMStructs;
269 private:
270 // The following method is not MT-safe and must be done under lock.
271 SymbolPropertyEntry** bucket_addr(int i) {
272 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
273 }
274
275 void add_entry(int index, SymbolPropertyEntry* new_entry) {
276 ShouldNotReachHere();
277 }
278 void set_entry(int index, SymbolPropertyEntry* new_entry) {
279 ShouldNotReachHere();
280 }
281
282 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
283 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
284 // Hashtable with Symbol* literal must increment and decrement refcount.
285 symbol->increment_refcount();
286 entry->set_symbol_mode(symbol_mode);
287 entry->set_method(NULL);
288 entry->set_method_type(NULL);
289 return entry;
290 }
291
292 public:
293 SymbolPropertyTable(int table_size);
294 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
295
296 void free_entry(SymbolPropertyEntry* entry) {
297 // decrement Symbol refcount here because hashtable doesn't.
298 entry->literal()->decrement_refcount();
299 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
300 }
301
302 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
303 // Use the regular identity_hash.
304 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
305 }
306
307 int index_for(Symbol* name, intptr_t symbol_mode) {
308 return hash_to_index(compute_hash(name, symbol_mode));
309 }
310
311 // need not be locked; no state change
312 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
313
314 // must be done under SystemDictionary_lock
315 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
316
317 // GC support
318 void oops_do(OopClosure* f);
319
320 void methods_do(void f(Method*));
321
322 void verify();
323
324 SymbolPropertyEntry* bucket(int i) {
325 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
326 }
327 };
328 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP