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.
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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.inline.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) {
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
72 public:
73 Dictionary(int table_size);
74 Dictionary(int table_size, HashtableBucket<mtClass>* t, int number_of_entries);
75
76 DictionaryEntry* new_entry(unsigned int hash, Klass* klass, ClassLoaderData* loader_data);
77
78 DictionaryEntry* new_entry();
79
80 void free_entry(DictionaryEntry* entry);
81
82 void add_klass(Symbol* class_name, ClassLoaderData* loader_data,KlassHandle obj);
83
84 Klass* find_class(int index, unsigned int hash,
85 Symbol* name, ClassLoaderData* loader_data);
86
87 Klass* find_shared_class(int index, unsigned int hash, Symbol* name);
88
89 // Compiler support
90 Klass* try_get_next_class();
91
92 // GC support
93 void oops_do(OopClosure* f);
94 void always_strong_oops_do(OopClosure* blk);
95 void roots_oops_do(OopClosure* strong, OopClosure* weak);
96
97 void always_strong_classes_do(KlassClosure* closure);
98
99 void classes_do(void f(Klass*));
100 void classes_do(void f(Klass*, TRAPS), TRAPS);
101 void classes_do(void f(Klass*, ClassLoaderData*));
102
103 void methods_do(void f(Method*));
104
105 void unlink(BoolObjectClosure* is_alive);
106 void remove_classes_in_error_state();
107
108 // Classes loaded by the bootstrap loader are always strongly reachable.
109 // If we're not doing class unloading, all classes are strongly reachable.
110 static bool is_strongly_reachable(ClassLoaderData* loader_data, Klass* klass) {
111 assert (klass != NULL, "should have non-null klass");
112 return (loader_data->is_the_null_class_loader_data() || !ClassUnloading);
113 }
114
115 // Unload (that is, break root links to) all unmarked classes and loaders.
116 void do_unloading();
117
118 // Protection domains
119 Klass* find(int index, unsigned int hash, Symbol* name,
120 ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
121 bool is_valid_protection_domain(int index, unsigned int hash,
122 Symbol* name, ClassLoaderData* loader_data,
123 Handle protection_domain);
124 void add_protection_domain(int index, unsigned int hash,
125 instanceKlassHandle klass, ClassLoaderData* loader_data,
126 Handle protection_domain, TRAPS);
127
128 // Sharing support
129 void reorder_dictionary();
130
131 ProtectionDomainCacheEntry* cache_get(oop protection_domain);
132
133 void print(bool details = true);
134 void verify();
135 };
136
137 // The following classes can be in dictionary.cpp, but we need these
138 // to be in header file so that SA's vmStructs can access them.
139 class ProtectionDomainCacheEntry : public HashtableEntry<oop, mtClass> {
140 friend class VMStructs;
141 private:
142 // Flag indicating whether this protection domain entry is strongly reachable.
143 // Used during iterating over the system dictionary to remember oops that need
144 // to be updated.
145 bool _strongly_reachable;
146 public:
147 oop protection_domain() { return literal(); }
148
149 void init() {
150 _strongly_reachable = false;
151 }
152
153 ProtectionDomainCacheEntry* next() {
154 return (ProtectionDomainCacheEntry*)HashtableEntry<oop, mtClass>::next();
155 }
156
157 ProtectionDomainCacheEntry** next_addr() {
158 return (ProtectionDomainCacheEntry**)HashtableEntry<oop, mtClass>::next_addr();
159 }
160
161 void oops_do(OopClosure* f) {
162 f->do_oop(literal_addr());
163 }
164
165 void set_strongly_reachable() { _strongly_reachable = true; }
166 bool is_strongly_reachable() { return _strongly_reachable; }
167 void reset_strongly_reachable() { _strongly_reachable = false; }
168
169 void print() PRODUCT_RETURN;
170 void verify();
171 };
172
173 // The ProtectionDomainCacheTable contains all protection domain oops. The system
174 // dictionary entries reference its entries instead of having references to oops
175 // directly.
176 // This is used to speed up system dictionary iteration: the oops in the
177 // protection domain are the only ones referring the Java heap. So when there is
178 // need to update these, instead of going over every entry of the system dictionary,
179 // we only need to iterate over this set.
180 // The amount of different protection domains used is typically magnitudes smaller
181 // than the number of system dictionary entries (loaded classes).
182 class ProtectionDomainCacheTable : public Hashtable<oop, mtClass> {
183 friend class VMStructs;
184 private:
185 ProtectionDomainCacheEntry* bucket(int i) {
186 return (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::bucket(i);
187 }
188
189 // The following method is not MT-safe and must be done under lock.
190 ProtectionDomainCacheEntry** bucket_addr(int i) {
191 return (ProtectionDomainCacheEntry**) Hashtable<oop, mtClass>::bucket_addr(i);
192 }
193
194 ProtectionDomainCacheEntry* new_entry(unsigned int hash, oop protection_domain) {
195 ProtectionDomainCacheEntry* entry = (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::new_entry(hash, protection_domain);
196 entry->init();
197 return entry;
198 }
199
200 static unsigned int compute_hash(oop protection_domain) {
201 return (unsigned int)(protection_domain->identity_hash());
202 }
203
204 int index_for(oop protection_domain) {
205 return hash_to_index(compute_hash(protection_domain));
206 }
207
208 ProtectionDomainCacheEntry* add_entry(int index, unsigned int hash, oop protection_domain);
209 ProtectionDomainCacheEntry* find_entry(int index, oop protection_domain);
210
211 public:
212
213 ProtectionDomainCacheTable(int table_size);
214
215 ProtectionDomainCacheEntry* get(oop protection_domain);
216 void free(ProtectionDomainCacheEntry* entry);
217
218 void unlink(BoolObjectClosure* cl);
219
220 // GC support
221 void oops_do(OopClosure* f);
222 void always_strong_oops_do(OopClosure* f);
223 void roots_oops_do(OopClosure* strong, OopClosure* weak);
224
225 static uint bucket_size();
226
227 void print() PRODUCT_RETURN;
228 void verify();
229 };
230
231
232 class ProtectionDomainEntry :public CHeapObj<mtClass> {
233 friend class VMStructs;
234 public:
235 ProtectionDomainEntry* _next;
236 ProtectionDomainCacheEntry* _pd_cache;
237
238 ProtectionDomainEntry(ProtectionDomainCacheEntry* pd_cache, ProtectionDomainEntry* next) {
239 _pd_cache = pd_cache;
240 _next = next;
241 }
242
243 ProtectionDomainEntry* next() { return _next; }
244 oop protection_domain() { return _pd_cache->protection_domain(); }
245 };
246
247 // An entry in the system dictionary, this describes a class as
248 // { Klass*, loader, protection_domain }.
249
250 class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
251 friend class VMStructs;
252 private:
253 // Contains the set of approved protection domains that can access
254 // this system dictionary entry.
255 //
256 // This protection domain set is a set of tuples:
257 //
258 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
259 //
260 // [Note that C.protection_domain(), which is stored in the java.lang.Class
261 // mirror of C, is NOT the same as PD]
262 //
263 // If such an entry (C, ICL, PD) exists in the table, it means that
264 // it is okay for a class Foo to reference C, where
265 //
266 // Foo.protection_domain() == PD, and
267 // Foo's defining class loader == ICL
268 //
269 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
270 // It is essentially a cache to avoid repeated Java up-calls to
271 // ClassLoader.checkPackageAccess().
272 //
273 ProtectionDomainEntry* _pd_set;
274 ClassLoaderData* _loader_data;
275
276 public:
277 // Tells whether a protection is in the approved set.
278 bool contains_protection_domain(oop protection_domain) const;
279 // Adds a protection domain to the approved set.
280 void add_protection_domain(Dictionary* dict, oop protection_domain);
281
282 Klass* klass() const { return (Klass*)literal(); }
283 Klass** klass_addr() { return (Klass**)literal_addr(); }
284
285 DictionaryEntry* next() const {
286 return (DictionaryEntry*)HashtableEntry<Klass*, mtClass>::next();
287 }
288
289 DictionaryEntry** next_addr() {
290 return (DictionaryEntry**)HashtableEntry<Klass*, mtClass>::next_addr();
291 }
292
293 ClassLoaderData* loader_data() const { return _loader_data; }
294 void set_loader_data(ClassLoaderData* loader_data) { _loader_data = loader_data; }
295
296 ProtectionDomainEntry* pd_set() const { return _pd_set; }
297 void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; }
298
299 bool has_protection_domain() { return _pd_set != NULL; }
300
301 // Tells whether the initiating class' protection can access the this _klass
302 bool is_valid_protection_domain(Handle protection_domain) {
303 if (!ProtectionDomainVerification) return true;
304 if (!SystemDictionary::has_checkPackageAccess()) return true;
305
306 return protection_domain() == NULL
307 ? true
308 : contains_protection_domain(protection_domain());
309 }
310
311 void set_strongly_reachable() {
312 for (ProtectionDomainEntry* current = _pd_set;
313 current != NULL;
314 current = current->_next) {
315 current->_pd_cache->set_strongly_reachable();
316 }
317 }
318
319 void verify_protection_domain_set() {
320 for (ProtectionDomainEntry* current = _pd_set;
321 current != NULL;
322 current = current->_next) {
323 current->_pd_cache->protection_domain()->verify();
324 }
325 }
326
327 bool equals(Symbol* class_name, ClassLoaderData* loader_data) const {
328 Klass* klass = (Klass*)literal();
329 return (InstanceKlass::cast(klass)->name() == class_name &&
330 _loader_data == loader_data);
331 }
332
333 void print() {
334 int count = 0;
335 for (ProtectionDomainEntry* current = _pd_set;
336 current != NULL;
337 current = current->_next) {
338 count++;
339 }
340 tty->print_cr("pd set = #%d", count);
341 }
342 };
343
344 // Entry in a SymbolPropertyTable, mapping a single Symbol*
345 // to a managed and an unmanaged pointer.
346 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
347 friend class VMStructs;
348 private:
349 intptr_t _symbol_mode; // secondary key
350 Method* _method;
351 oop _method_type;
352
353 public:
354 Symbol* symbol() const { return literal(); }
355
356 intptr_t symbol_mode() const { return _symbol_mode; }
357 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
358
359 Method* method() const { return _method; }
360 void set_method(Method* p) { _method = p; }
361
362 oop method_type() const { return _method_type; }
363 oop* method_type_addr() { return &_method_type; }
364 void set_method_type(oop p) { _method_type = p; }
365
366 SymbolPropertyEntry* next() const {
367 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
368 }
369
370 SymbolPropertyEntry** next_addr() {
371 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
372 }
373
374 void print_on(outputStream* st) const {
375 symbol()->print_value_on(st);
376 st->print("/mode="INTX_FORMAT, symbol_mode());
377 st->print(" -> ");
378 bool printed = false;
379 if (method() != NULL) {
380 method()->print_value_on(st);
381 printed = true;
382 }
383 if (method_type() != NULL) {
384 if (printed) st->print(" and ");
385 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
386 printed = true;
387 }
388 st->print_cr(printed ? "" : "(empty)");
389 }
390 };
391
392 // A system-internal mapping of symbols to pointers, both managed
393 // and unmanaged. Used to record the auto-generation of each method
394 // MethodHandle.invoke(S)T, for all signatures (S)T.
395 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
396 friend class VMStructs;
397 private:
398 SymbolPropertyEntry* bucket(int i) {
399 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
400 }
401
402 // The following method is not MT-safe and must be done under lock.
403 SymbolPropertyEntry** bucket_addr(int i) {
404 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
405 }
406
407 void add_entry(int index, SymbolPropertyEntry* new_entry) {
408 ShouldNotReachHere();
409 }
410 void set_entry(int index, SymbolPropertyEntry* new_entry) {
411 ShouldNotReachHere();
412 }
413
414 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
415 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
416 // Hashtable with Symbol* literal must increment and decrement refcount.
417 symbol->increment_refcount();
418 entry->set_symbol_mode(symbol_mode);
419 entry->set_method(NULL);
420 entry->set_method_type(NULL);
421 return entry;
422 }
423
424 public:
425 SymbolPropertyTable(int table_size);
426 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
427
428 void free_entry(SymbolPropertyEntry* entry) {
429 // decrement Symbol refcount here because hashtable doesn't.
430 entry->literal()->decrement_refcount();
431 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
432 }
433
434 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
435 // Use the regular identity_hash.
436 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
437 }
438
439 int index_for(Symbol* name, intptr_t symbol_mode) {
440 return hash_to_index(compute_hash(name, symbol_mode));
441 }
442
443 // need not be locked; no state change
444 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
445
446 // must be done under SystemDictionary_lock
447 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
448
449 // GC support
450 void oops_do(OopClosure* f);
451
452 void methods_do(void f(Method*));
453
454 // Sharing support
455 void reorder_dictionary();
456
457 #ifndef PRODUCT
458 void print();
459 #endif
460 void verify();
461 };
462 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP