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.
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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.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 unlink(BoolObjectClosure* is_alive);
104 void remove_classes_in_error_state();
105
106 // Classes loaded by the bootstrap loader are always strongly reachable.
107 // If we're not doing class unloading, all classes are strongly reachable.
108 static bool is_strongly_reachable(ClassLoaderData* loader_data, Klass* klass) {
109 assert (klass != NULL, "should have non-null klass");
110 return (loader_data->is_the_null_class_loader_data() || !ClassUnloading);
111 }
112
113 // Unload (that is, break root links to) all unmarked classes and loaders.
114 void do_unloading();
115
116 // Protection domains
117 Klass* find(int index, unsigned int hash, Symbol* name,
118 ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
119 bool is_valid_protection_domain(int index, unsigned int hash,
120 Symbol* name, ClassLoaderData* loader_data,
121 Handle protection_domain);
122 void add_protection_domain(int index, unsigned int hash,
123 instanceKlassHandle klass, ClassLoaderData* loader_data,
124 Handle protection_domain, TRAPS);
125
126 // Sharing support
127 void reorder_dictionary();
128
129 ProtectionDomainCacheEntry* cache_get(Handle protection_domain);
130
131 void print(bool details = true);
132 #ifdef ASSERT
133 void printPerformanceInfoDetails();
134 #endif // ASSERT
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, Handle 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(Handle protection_domain);
202
203 int index_for(Handle protection_domain);
204 ProtectionDomainCacheEntry* add_entry(int index, unsigned int hash, Handle protection_domain);
205 ProtectionDomainCacheEntry* find_entry(int index, Handle protection_domain);
206
207 public:
208
209 ProtectionDomainCacheTable(int table_size);
210
211 ProtectionDomainCacheEntry* get(Handle protection_domain);
212 void free(ProtectionDomainCacheEntry* entry);
213
214 void unlink(BoolObjectClosure* cl);
215
216 // GC support
217 void oops_do(OopClosure* f);
218 void always_strong_oops_do(OopClosure* f);
219 void roots_oops_do(OopClosure* strong, OopClosure* weak);
220
221 static uint bucket_size();
222
223 void print() PRODUCT_RETURN;
224 void verify();
225 };
226
227
228 class ProtectionDomainEntry :public CHeapObj<mtClass> {
229 friend class VMStructs;
230 public:
231 ProtectionDomainEntry* _next;
232 ProtectionDomainCacheEntry* _pd_cache;
233
234 ProtectionDomainEntry(ProtectionDomainCacheEntry* pd_cache, ProtectionDomainEntry* next) {
235 _pd_cache = pd_cache;
236 _next = next;
237 }
238
239 ProtectionDomainEntry* next() { return _next; }
240 oop protection_domain() { return _pd_cache->protection_domain(); }
241 };
242
243 // An entry in the system dictionary, this describes a class as
244 // { Klass*, loader, protection_domain }.
245
246 class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
247 friend class VMStructs;
248 private:
249 // Contains the set of approved protection domains that can access
250 // this system dictionary entry.
251 //
252 // This protection domain set is a set of tuples:
253 //
254 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
255 //
256 // [Note that C.protection_domain(), which is stored in the java.lang.Class
257 // mirror of C, is NOT the same as PD]
258 //
259 // If such an entry (C, ICL, PD) exists in the table, it means that
260 // it is okay for a class Foo to reference C, where
261 //
262 // Foo.protection_domain() == PD, and
263 // Foo's defining class loader == ICL
264 //
265 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
266 // It is essentially a cache to avoid repeated Java up-calls to
267 // ClassLoader.checkPackageAccess().
268 //
269 ProtectionDomainEntry* _pd_set;
270 ClassLoaderData* _loader_data;
271
272 public:
273 // Tells whether a protection is in the approved set.
274 bool contains_protection_domain(oop protection_domain) const;
275 // Adds a protection domain to the approved set.
276 void add_protection_domain(Dictionary* dict, Handle protection_domain);
277
278 Klass* klass() const { return (Klass*)literal(); }
279 Klass** klass_addr() { return (Klass**)literal_addr(); }
280
281 DictionaryEntry* next() const {
282 return (DictionaryEntry*)HashtableEntry<Klass*, mtClass>::next();
283 }
284
285 DictionaryEntry** next_addr() {
286 return (DictionaryEntry**)HashtableEntry<Klass*, mtClass>::next_addr();
287 }
288
289 ClassLoaderData* loader_data() const { return _loader_data; }
290 void set_loader_data(ClassLoaderData* loader_data) { _loader_data = loader_data; }
291
292 ProtectionDomainEntry* pd_set() const { return _pd_set; }
293 void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; }
294
295 bool has_protection_domain() { return _pd_set != NULL; }
296
297 // Tells whether the initiating class' protection can access the this _klass
298 bool is_valid_protection_domain(Handle protection_domain) {
299 if (!ProtectionDomainVerification) return true;
300 if (!SystemDictionary::has_checkPackageAccess()) return true;
301
302 return protection_domain() == NULL
303 ? true
304 : contains_protection_domain(protection_domain());
305 }
306
307 void set_strongly_reachable() {
308 for (ProtectionDomainEntry* current = _pd_set;
309 current != NULL;
310 current = current->_next) {
311 current->_pd_cache->set_strongly_reachable();
312 }
313 }
314
315 void verify_protection_domain_set() {
316 for (ProtectionDomainEntry* current = _pd_set;
317 current != NULL;
318 current = current->_next) {
319 current->_pd_cache->protection_domain()->verify();
320 }
321 }
322
323 bool equals(const Symbol* class_name, ClassLoaderData* loader_data) const {
324 Klass* klass = (Klass*)literal();
325 return (klass->name() == class_name && _loader_data == loader_data);
326 }
327
328 void print_count(outputStream *st) {
329 int count = 0;
330 for (ProtectionDomainEntry* current = _pd_set;
331 current != NULL;
332 current = current->_next) {
333 count++;
334 }
335 st->print_cr("pd set count = #%d", count);
336 }
337 };
338
339 // Entry in a SymbolPropertyTable, mapping a single Symbol*
340 // to a managed and an unmanaged pointer.
341 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
342 friend class VMStructs;
343 private:
344 intptr_t _symbol_mode; // secondary key
345 Method* _method;
346 oop _method_type;
347
348 public:
349 Symbol* symbol() const { return literal(); }
350
351 intptr_t symbol_mode() const { return _symbol_mode; }
352 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
353
354 Method* method() const { return _method; }
355 void set_method(Method* p) { _method = p; }
356
357 oop method_type() const { return _method_type; }
358 oop* method_type_addr() { return &_method_type; }
359 void set_method_type(oop p) { _method_type = p; }
360
361 SymbolPropertyEntry* next() const {
362 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
363 }
364
365 SymbolPropertyEntry** next_addr() {
366 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
367 }
368
369 void print_on(outputStream* st) const {
370 symbol()->print_value_on(st);
371 st->print("/mode=" INTX_FORMAT, symbol_mode());
372 st->print(" -> ");
373 bool printed = false;
374 if (method() != NULL) {
375 method()->print_value_on(st);
376 printed = true;
377 }
378 if (method_type() != NULL) {
379 if (printed) st->print(" and ");
380 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
381 printed = true;
382 }
383 st->print_cr(printed ? "" : "(empty)");
384 }
385 };
386
387 // A system-internal mapping of symbols to pointers, both managed
388 // and unmanaged. Used to record the auto-generation of each method
389 // MethodHandle.invoke(S)T, for all signatures (S)T.
390 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
391 friend class VMStructs;
392 private:
393 SymbolPropertyEntry* bucket(int i) {
394 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
395 }
396
397 // The following method is not MT-safe and must be done under lock.
398 SymbolPropertyEntry** bucket_addr(int i) {
399 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
400 }
401
402 void add_entry(int index, SymbolPropertyEntry* new_entry) {
403 ShouldNotReachHere();
404 }
405 void set_entry(int index, SymbolPropertyEntry* new_entry) {
406 ShouldNotReachHere();
407 }
408
409 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
410 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
411 // Hashtable with Symbol* literal must increment and decrement refcount.
412 symbol->increment_refcount();
413 entry->set_symbol_mode(symbol_mode);
414 entry->set_method(NULL);
415 entry->set_method_type(NULL);
416 return entry;
417 }
418
419 public:
420 SymbolPropertyTable(int table_size);
421 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
422
423 void free_entry(SymbolPropertyEntry* entry) {
424 // decrement Symbol refcount here because hashtable doesn't.
425 entry->literal()->decrement_refcount();
426 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
427 }
428
429 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
430 // Use the regular identity_hash.
431 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
432 }
433
434 int index_for(Symbol* name, intptr_t symbol_mode) {
435 return hash_to_index(compute_hash(name, symbol_mode));
436 }
437
438 // need not be locked; no state change
439 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
440
441 // must be done under SystemDictionary_lock
442 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
443
444 // GC support
445 void oops_do(OopClosure* f);
446
447 void methods_do(void f(Method*));
448
449 // Sharing support
450 void reorder_dictionary();
451
452 #ifndef PRODUCT
453 void print();
454 #endif
455 void verify();
456 };
457 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP