1 /*
2 * Copyright (c) 2003, 2016, 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/systemDictionary.hpp"
29 #include "oops/instanceKlass.hpp"
30 #include "oops/oop.hpp"
31 #include "utilities/hashtable.hpp"
32
33 class DictionaryEntry;
34 class PSPromotionManager;
35 class ProtectionDomainCacheTable;
36 class ProtectionDomainCacheEntry;
37 class BoolObjectClosure;
38
39 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
40 // The data structure for the system dictionary (and the shared system
41 // dictionary).
42
43 class Dictionary : public TwoOopHashtable<Klass*, mtClass> {
44 friend class VMStructs;
45 private:
46 // current iteration index.
47 static int _current_class_index;
48 // pointer to the current hash table entry.
49 static DictionaryEntry* _current_class_entry;
50
51 ProtectionDomainCacheTable* _pd_cache_table;
52
53 DictionaryEntry* get_entry(int index, unsigned int hash,
54 Symbol* name, ClassLoaderData* loader_data);
55
56 protected:
57 DictionaryEntry* bucket(int i) const {
58 return (DictionaryEntry*)Hashtable<Klass*, mtClass>::bucket(i);
59 }
60
61 // The following method is not MT-safe and must be done under lock.
62 DictionaryEntry** bucket_addr(int i) {
63 return (DictionaryEntry**)Hashtable<Klass*, mtClass>::bucket_addr(i);
64 }
65
66 void add_entry(int index, DictionaryEntry* new_entry) {
67 Hashtable<Klass*, mtClass>::add_entry(index, (HashtableEntry<Klass*, mtClass>*)new_entry);
68 }
69
70 static size_t entry_size();
71 public:
72 Dictionary(int table_size);
73 Dictionary(int table_size, HashtableBucket<mtClass>* t, int number_of_entries);
74
75 DictionaryEntry* new_entry(unsigned int hash, Klass* klass, ClassLoaderData* loader_data);
76
77 DictionaryEntry* new_entry();
78
79 void free_entry(DictionaryEntry* entry);
80
81 void add_klass(Symbol* class_name, ClassLoaderData* loader_data,KlassHandle obj);
82
83 Klass* find_class(int index, unsigned int hash,
84 Symbol* name, ClassLoaderData* loader_data);
85
86 Klass* find_shared_class(int index, unsigned int hash, Symbol* name);
87
88 // Compiler support
89 Klass* try_get_next_class();
90
91 // GC support
92 void oops_do(OopClosure* f);
93 void always_strong_oops_do(OopClosure* blk);
94 void roots_oops_do(OopClosure* strong, OopClosure* weak);
95
96 void always_strong_classes_do(KlassClosure* closure);
97
98 void classes_do(void f(Klass*));
99 void classes_do(void f(Klass*, TRAPS), TRAPS);
100 void classes_do(void f(Klass*, ClassLoaderData*));
101
102 void methods_do(void f(Method*));
103
104 void unlink(BoolObjectClosure* is_alive);
105 void remove_classes_in_error_state();
106
107 // Classes loaded by the bootstrap loader are always strongly reachable.
108 // If we're not doing class unloading, all classes are strongly reachable.
109 static bool is_strongly_reachable(ClassLoaderData* loader_data, Klass* klass) {
110 assert (klass != NULL, "should have non-null klass");
111 return (loader_data->is_the_null_class_loader_data() || !ClassUnloading);
112 }
113
114 // Unload (that is, break root links to) all unmarked classes and loaders.
115 void do_unloading();
116
117 // Protection domains
118 Klass* find(int index, unsigned int hash, Symbol* name,
119 ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
120 bool is_valid_protection_domain(int index, unsigned int hash,
121 Symbol* name, ClassLoaderData* loader_data,
122 Handle protection_domain);
123 void add_protection_domain(int index, unsigned int hash,
124 instanceKlassHandle klass, ClassLoaderData* loader_data,
125 Handle protection_domain, TRAPS);
126
127 // Sharing support
128 void reorder_dictionary();
129
130 ProtectionDomainCacheEntry* cache_get(oop protection_domain);
131
132 void print(bool details = true);
133 void verify();
134 };
135
136 // The following classes can be in dictionary.cpp, but we need these
137 // to be in header file so that SA's vmStructs can access them.
138 class ProtectionDomainCacheEntry : public HashtableEntry<oop, mtClass> {
139 friend class VMStructs;
140 private:
141 // Flag indicating whether this protection domain entry is strongly reachable.
142 // Used during iterating over the system dictionary to remember oops that need
143 // to be updated.
144 bool _strongly_reachable;
145 public:
146 oop protection_domain() { return literal(); }
147
148 void init() {
149 _strongly_reachable = false;
150 }
151
152 ProtectionDomainCacheEntry* next() {
153 return (ProtectionDomainCacheEntry*)HashtableEntry<oop, mtClass>::next();
154 }
155
156 ProtectionDomainCacheEntry** next_addr() {
157 return (ProtectionDomainCacheEntry**)HashtableEntry<oop, mtClass>::next_addr();
158 }
159
160 void oops_do(OopClosure* f) {
161 f->do_oop(literal_addr());
162 }
163
164 void set_strongly_reachable() { _strongly_reachable = true; }
165 bool is_strongly_reachable() { return _strongly_reachable; }
166 void reset_strongly_reachable() { _strongly_reachable = false; }
167
168 void print() PRODUCT_RETURN;
169 void verify();
170 };
171
172 // The ProtectionDomainCacheTable contains all protection domain oops. The system
173 // dictionary entries reference its entries instead of having references to oops
174 // directly.
175 // This is used to speed up system dictionary iteration: the oops in the
176 // protection domain are the only ones referring the Java heap. So when there is
177 // need to update these, instead of going over every entry of the system dictionary,
178 // we only need to iterate over this set.
179 // The amount of different protection domains used is typically magnitudes smaller
180 // than the number of system dictionary entries (loaded classes).
181 class ProtectionDomainCacheTable : public Hashtable<oop, mtClass> {
182 friend class VMStructs;
183 private:
184 ProtectionDomainCacheEntry* bucket(int i) {
185 return (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::bucket(i);
186 }
187
188 // The following method is not MT-safe and must be done under lock.
189 ProtectionDomainCacheEntry** bucket_addr(int i) {
190 return (ProtectionDomainCacheEntry**) Hashtable<oop, mtClass>::bucket_addr(i);
191 }
192
193 ProtectionDomainCacheEntry* new_entry(unsigned int hash, oop protection_domain) {
194 ProtectionDomainCacheEntry* entry = (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::new_entry(hash, protection_domain);
195 entry->init();
196 return entry;
197 }
198
199 static unsigned int compute_hash(oop protection_domain);
200
201 int index_for(oop protection_domain);
202 ProtectionDomainCacheEntry* add_entry(int index, unsigned int hash, oop protection_domain);
203 ProtectionDomainCacheEntry* find_entry(int index, oop protection_domain);
204
205 public:
206
207 ProtectionDomainCacheTable(int table_size);
208
209 ProtectionDomainCacheEntry* get(oop protection_domain);
210 void free(ProtectionDomainCacheEntry* entry);
211
212 void unlink(BoolObjectClosure* cl);
213
214 // GC support
215 void oops_do(OopClosure* f);
216 void always_strong_oops_do(OopClosure* f);
217 void roots_oops_do(OopClosure* strong, OopClosure* weak);
218
219 static uint bucket_size();
220
221 void print() PRODUCT_RETURN;
222 void verify();
223 };
224
225
226 class ProtectionDomainEntry :public CHeapObj<mtClass> {
227 friend class VMStructs;
228 public:
229 ProtectionDomainEntry* _next;
230 ProtectionDomainCacheEntry* _pd_cache;
231
232 ProtectionDomainEntry(ProtectionDomainCacheEntry* pd_cache, ProtectionDomainEntry* next) {
233 _pd_cache = pd_cache;
234 _next = next;
235 }
236
237 ProtectionDomainEntry* next() { return _next; }
238 oop protection_domain() { return _pd_cache->protection_domain(); }
239 };
240
241 // An entry in the system dictionary, this describes a class as
242 // { Klass*, loader, protection_domain }.
243
244 class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
245 friend class VMStructs;
246 private:
247 // Contains the set of approved protection domains that can access
248 // this system dictionary entry.
249 //
250 // This protection domain set is a set of tuples:
251 //
252 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
253 //
254 // [Note that C.protection_domain(), which is stored in the java.lang.Class
255 // mirror of C, is NOT the same as PD]
256 //
257 // If such an entry (C, ICL, PD) exists in the table, it means that
258 // it is okay for a class Foo to reference C, where
259 //
260 // Foo.protection_domain() == PD, and
261 // Foo's defining class loader == ICL
262 //
263 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
264 // It is essentially a cache to avoid repeated Java up-calls to
265 // ClassLoader.checkPackageAccess().
266 //
267 ProtectionDomainEntry* _pd_set;
268 ClassLoaderData* _loader_data;
269
270 public:
271 // Tells whether a protection is in the approved set.
272 bool contains_protection_domain(oop protection_domain) const;
273 // Adds a protection domain to the approved set.
274 void add_protection_domain(Dictionary* dict, oop protection_domain);
275
276 Klass* klass() const { return (Klass*)literal(); }
277 Klass** klass_addr() { return (Klass**)literal_addr(); }
278
279 DictionaryEntry* next() const {
280 return (DictionaryEntry*)HashtableEntry<Klass*, mtClass>::next();
281 }
282
283 DictionaryEntry** next_addr() {
284 return (DictionaryEntry**)HashtableEntry<Klass*, mtClass>::next_addr();
285 }
286
287 ClassLoaderData* loader_data() const { return _loader_data; }
288 void set_loader_data(ClassLoaderData* loader_data) { _loader_data = loader_data; }
289
290 ProtectionDomainEntry* pd_set() const { return _pd_set; }
291 void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; }
292
293 bool has_protection_domain() { return _pd_set != NULL; }
294
295 // Tells whether the initiating class' protection can access the this _klass
296 bool is_valid_protection_domain(Handle protection_domain) {
297 if (!ProtectionDomainVerification) return true;
298 if (!SystemDictionary::has_checkPackageAccess()) return true;
299
300 return protection_domain() == NULL
301 ? true
302 : contains_protection_domain(protection_domain());
303 }
304
305 void set_strongly_reachable() {
306 for (ProtectionDomainEntry* current = _pd_set;
307 current != NULL;
308 current = current->_next) {
309 current->_pd_cache->set_strongly_reachable();
310 }
311 }
312
313 void verify_protection_domain_set() {
314 for (ProtectionDomainEntry* current = _pd_set;
315 current != NULL;
316 current = current->_next) {
317 current->_pd_cache->protection_domain()->verify();
318 }
319 }
320
321 bool equals(const Symbol* class_name, ClassLoaderData* loader_data) const {
322 Klass* klass = (Klass*)literal();
323 return (klass->name() == class_name && _loader_data == loader_data);
324 }
325
326 void print() {
327 int count = 0;
328 for (ProtectionDomainEntry* current = _pd_set;
329 current != NULL;
330 current = current->_next) {
331 count++;
332 }
333 tty->print_cr("pd set = #%d", count);
334 }
335 };
336
337 // Entry in a SymbolPropertyTable, mapping a single Symbol*
338 // to a managed and an unmanaged pointer.
339 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
340 friend class VMStructs;
341 private:
342 intptr_t _symbol_mode; // secondary key
343 Method* _method;
344 oop _method_type;
345
346 public:
347 Symbol* symbol() const { return literal(); }
348
349 intptr_t symbol_mode() const { return _symbol_mode; }
350 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
351
352 Method* method() const { return _method; }
353 void set_method(Method* p) { _method = p; }
354
355 oop method_type() const { return _method_type; }
356 oop* method_type_addr() { return &_method_type; }
357 void set_method_type(oop p) { _method_type = p; }
358
359 SymbolPropertyEntry* next() const {
360 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
361 }
362
363 SymbolPropertyEntry** next_addr() {
364 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
365 }
366
367 void print_on(outputStream* st) const {
368 symbol()->print_value_on(st);
369 st->print("/mode=" INTX_FORMAT, symbol_mode());
370 st->print(" -> ");
371 bool printed = false;
372 if (method() != NULL) {
373 method()->print_value_on(st);
374 printed = true;
375 }
376 if (method_type() != NULL) {
377 if (printed) st->print(" and ");
378 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
379 printed = true;
380 }
381 st->print_cr(printed ? "" : "(empty)");
382 }
383 };
384
385 // A system-internal mapping of symbols to pointers, both managed
386 // and unmanaged. Used to record the auto-generation of each method
387 // MethodHandle.invoke(S)T, for all signatures (S)T.
388 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
389 friend class VMStructs;
390 private:
391 SymbolPropertyEntry* bucket(int i) {
392 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
393 }
394
395 // The following method is not MT-safe and must be done under lock.
396 SymbolPropertyEntry** bucket_addr(int i) {
397 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
398 }
399
400 void add_entry(int index, SymbolPropertyEntry* new_entry) {
401 ShouldNotReachHere();
402 }
403 void set_entry(int index, SymbolPropertyEntry* new_entry) {
404 ShouldNotReachHere();
405 }
406
407 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
408 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
409 // Hashtable with Symbol* literal must increment and decrement refcount.
410 symbol->increment_refcount();
411 entry->set_symbol_mode(symbol_mode);
412 entry->set_method(NULL);
413 entry->set_method_type(NULL);
414 return entry;
415 }
416
417 public:
418 SymbolPropertyTable(int table_size);
419 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
420
421 void free_entry(SymbolPropertyEntry* entry) {
422 // decrement Symbol refcount here because hashtable doesn't.
423 entry->literal()->decrement_refcount();
424 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
425 }
426
427 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
428 // Use the regular identity_hash.
429 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
430 }
431
432 int index_for(Symbol* name, intptr_t symbol_mode) {
433 return hash_to_index(compute_hash(name, symbol_mode));
434 }
435
436 // need not be locked; no state change
437 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
438
439 // must be done under SystemDictionary_lock
440 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
441
442 // GC support
443 void oops_do(OopClosure* f);
444
445 void methods_do(void f(Method*));
446
447 // Sharing support
448 void reorder_dictionary();
449
450 #ifndef PRODUCT
451 void print();
452 #endif
453 void verify();
454 };
455 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP