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