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 #include "utilities/ostream.hpp"
33
34 class DictionaryEntry;
35 class PSPromotionManager;
36 class ProtectionDomainCacheTable;
37 class ProtectionDomainCacheEntry;
38 class BoolObjectClosure;
39
40 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
41 // The data structure for the system dictionary (and the shared system
42 // dictionary).
43
44 class Dictionary : public TwoOopHashtable<Klass*, mtClass> {
45 friend class VMStructs;
46 private:
47 // current iteration index.
48 static int _current_class_index;
49 // pointer to the current hash table entry.
50 static DictionaryEntry* _current_class_entry;
51
52 ProtectionDomainCacheTable* _pd_cache_table;
53
54 DictionaryEntry* get_entry(int index, unsigned int hash,
55 Symbol* name, ClassLoaderData* loader_data);
56
57 protected:
58 DictionaryEntry* bucket(int i) const {
59 return (DictionaryEntry*)Hashtable<Klass*, mtClass>::bucket(i);
60 }
61
62 // The following method is not MT-safe and must be done under lock.
63 DictionaryEntry** bucket_addr(int i) {
64 return (DictionaryEntry**)Hashtable<Klass*, mtClass>::bucket_addr(i);
65 }
66
67 void add_entry(int index, DictionaryEntry* new_entry) {
68 Hashtable<Klass*, mtClass>::add_entry(index, (HashtableEntry<Klass*, mtClass>*)new_entry);
69 }
70
71 static size_t entry_size();
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
202 int index_for(oop protection_domain);
203 ProtectionDomainCacheEntry* add_entry(int index, unsigned int hash, oop protection_domain);
204 ProtectionDomainCacheEntry* find_entry(int index, oop protection_domain);
205
206 public:
207
208 ProtectionDomainCacheTable(int table_size);
209
210 ProtectionDomainCacheEntry* get(oop protection_domain);
211 void free(ProtectionDomainCacheEntry* entry);
212
213 void unlink(BoolObjectClosure* cl);
214
215 // GC support
216 void oops_do(OopClosure* f);
217 void always_strong_oops_do(OopClosure* f);
218 void roots_oops_do(OopClosure* strong, OopClosure* weak);
219
220 static uint bucket_size();
221
222 void print() PRODUCT_RETURN;
223 void verify();
224 };
225
226
227 class ProtectionDomainEntry :public CHeapObj<mtClass> {
228 friend class VMStructs;
229 public:
230 ProtectionDomainEntry* _next;
231 ProtectionDomainCacheEntry* _pd_cache;
232
233 ProtectionDomainEntry(ProtectionDomainCacheEntry* pd_cache, ProtectionDomainEntry* next) {
234 _pd_cache = pd_cache;
235 _next = next;
236 }
237
238 ProtectionDomainEntry* next() { return _next; }
239 oop protection_domain() { return _pd_cache->protection_domain(); }
240 };
241
242 // An entry in the system dictionary, this describes a class as
243 // { Klass*, loader, protection_domain }.
244
245 class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
246 friend class VMStructs;
247 private:
248 // Contains the set of approved protection domains that can access
249 // this system dictionary entry.
250 //
251 // This protection domain set is a set of tuples:
252 //
253 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
254 //
255 // [Note that C.protection_domain(), which is stored in the java.lang.Class
256 // mirror of C, is NOT the same as PD]
257 //
258 // If such an entry (C, ICL, PD) exists in the table, it means that
259 // it is okay for a class Foo to reference C, where
260 //
261 // Foo.protection_domain() == PD, and
262 // Foo's defining class loader == ICL
263 //
264 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
265 // It is essentially a cache to avoid repeated Java up-calls to
266 // ClassLoader.checkPackageAccess().
267 //
268 ProtectionDomainEntry* _pd_set;
269 ClassLoaderData* _loader_data;
270
271 public:
272 // Tells whether a protection is in the approved set.
273 bool contains_protection_domain(oop protection_domain) const;
274 // Adds a protection domain to the approved set.
275 void add_protection_domain(Dictionary* dict, oop protection_domain);
276
277 Klass* klass() const { return (Klass*)literal(); }
278 Klass** klass_addr() { return (Klass**)literal_addr(); }
279
280 DictionaryEntry* next() const {
281 return (DictionaryEntry*)HashtableEntry<Klass*, mtClass>::next();
282 }
283
284 DictionaryEntry** next_addr() {
285 return (DictionaryEntry**)HashtableEntry<Klass*, mtClass>::next_addr();
286 }
287
288 ClassLoaderData* loader_data() const { return _loader_data; }
289 void set_loader_data(ClassLoaderData* loader_data) { _loader_data = loader_data; }
290
291 ProtectionDomainEntry* pd_set() const { return _pd_set; }
292 void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; }
293
294 bool has_protection_domain() { return _pd_set != NULL; }
295
296 // Tells whether the initiating class' protection can access the this _klass
297 bool is_valid_protection_domain(Handle protection_domain) {
298 if (!ProtectionDomainVerification) return true;
299 if (!SystemDictionary::has_checkPackageAccess()) return true;
300
301 return protection_domain() == NULL
302 ? true
303 : contains_protection_domain(protection_domain());
304 }
305
306 void set_strongly_reachable() {
307 for (ProtectionDomainEntry* current = _pd_set;
308 current != NULL;
309 current = current->_next) {
310 current->_pd_cache->set_strongly_reachable();
311 }
312 }
313
314 void verify_protection_domain_set() {
315 for (ProtectionDomainEntry* current = _pd_set;
316 current != NULL;
317 current = current->_next) {
318 current->_pd_cache->protection_domain()->verify();
319 }
320 }
321
322 bool equals(const Symbol* class_name, ClassLoaderData* loader_data) const {
323 Klass* klass = (Klass*)literal();
324 return (klass->name() == class_name && _loader_data == loader_data);
325 }
326
327 void print(outputStream *st) {
328 int count = 0;
329 for (ProtectionDomainEntry* current = _pd_set;
330 current != NULL;
331 current = current->_next) {
332 count++;
333 }
334 st->print_cr("pd set = #%d", count);
335 }
336 };
337
338 // Entry in a SymbolPropertyTable, mapping a single Symbol*
339 // to a managed and an unmanaged pointer.
340 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
341 friend class VMStructs;
342 private:
343 intptr_t _symbol_mode; // secondary key
344 Method* _method;
345 oop _method_type;
346
347 public:
348 Symbol* symbol() const { return literal(); }
349
350 intptr_t symbol_mode() const { return _symbol_mode; }
351 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
352
353 Method* method() const { return _method; }
354 void set_method(Method* p) { _method = p; }
355
356 oop method_type() const { return _method_type; }
357 oop* method_type_addr() { return &_method_type; }
358 void set_method_type(oop p) { _method_type = p; }
359
360 SymbolPropertyEntry* next() const {
361 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
362 }
363
364 SymbolPropertyEntry** next_addr() {
365 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
366 }
367
368 void print_on(outputStream* st) const {
369 symbol()->print_value_on(st);
370 st->print("/mode=" INTX_FORMAT, symbol_mode());
371 st->print(" -> ");
372 bool printed = false;
373 if (method() != NULL) {
374 method()->print_value_on(st);
375 printed = true;
376 }
377 if (method_type() != NULL) {
378 if (printed) st->print(" and ");
379 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
380 printed = true;
381 }
382 st->print_cr(printed ? "" : "(empty)");
383 }
384 };
385
386 // A system-internal mapping of symbols to pointers, both managed
387 // and unmanaged. Used to record the auto-generation of each method
388 // MethodHandle.invoke(S)T, for all signatures (S)T.
389 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
390 friend class VMStructs;
391 private:
392 SymbolPropertyEntry* bucket(int i) {
393 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
394 }
395
396 // The following method is not MT-safe and must be done under lock.
397 SymbolPropertyEntry** bucket_addr(int i) {
398 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
399 }
400
401 void add_entry(int index, SymbolPropertyEntry* new_entry) {
402 ShouldNotReachHere();
403 }
404 void set_entry(int index, SymbolPropertyEntry* new_entry) {
405 ShouldNotReachHere();
406 }
407
408 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
409 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
410 // Hashtable with Symbol* literal must increment and decrement refcount.
411 symbol->increment_refcount();
412 entry->set_symbol_mode(symbol_mode);
413 entry->set_method(NULL);
414 entry->set_method_type(NULL);
415 return entry;
416 }
417
418 public:
419 SymbolPropertyTable(int table_size);
420 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
421
422 void free_entry(SymbolPropertyEntry* entry) {
423 // decrement Symbol refcount here because hashtable doesn't.
424 entry->literal()->decrement_refcount();
425 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
426 }
427
428 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
429 // Use the regular identity_hash.
430 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
431 }
432
433 int index_for(Symbol* name, intptr_t symbol_mode) {
434 return hash_to_index(compute_hash(name, symbol_mode));
435 }
436
437 // need not be locked; no state change
438 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
439
440 // must be done under SystemDictionary_lock
441 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
442
443 // GC support
444 void oops_do(OopClosure* f);
445
446 void methods_do(void f(Method*));
447
448 // Sharing support
449 void reorder_dictionary();
450
451 #ifndef PRODUCT
452 void print();
453 #endif
454 void verify();
455 };
456 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP