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