1 /* 2 * Copyright (c) 2003, 2014, 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 21 * questions. 22 * 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 DictionaryEntry* bucket(int i) { 57 return (DictionaryEntry*)Hashtable<Klass*, mtClass>::bucket(i); 58 } 59 60 // The following method is not MT-safe and must be done under lock. 61 DictionaryEntry** bucket_addr(int i) { 62 return (DictionaryEntry**)Hashtable<Klass*, mtClass>::bucket_addr(i); 63 } 64 65 void add_entry(int index, DictionaryEntry* new_entry) { 66 Hashtable<Klass*, mtClass>::add_entry(index, (HashtableEntry<Klass*, mtClass>*)new_entry); 67 } 68 69 public: 70 Dictionary(int table_size); 71 Dictionary(int table_size, HashtableBucket<mtClass>* t, int number_of_entries); 72 73 DictionaryEntry* new_entry(unsigned int hash, Klass* klass, ClassLoaderData* loader_data); 74 75 DictionaryEntry* new_entry(); 76 77 void free_entry(DictionaryEntry* entry); 78 79 void add_klass(Symbol* class_name, ClassLoaderData* loader_data,KlassHandle obj); 80 81 Klass* find_class(int index, unsigned int hash, 82 Symbol* name, ClassLoaderData* loader_data); 83 84 Klass* find_shared_class(int index, unsigned int hash, Symbol* name); 85 86 // Compiler support 87 Klass* try_get_next_class(); 88 89 // GC support 90 void oops_do(OopClosure* f); 91 void always_strong_oops_do(OopClosure* blk); 92 void roots_oops_do(OopClosure* strong, OopClosure* weak); 93 94 void always_strong_classes_do(KlassClosure* closure); 95 96 void classes_do(void f(Klass*)); 97 void classes_do(void f(Klass*, TRAPS), TRAPS); 98 void classes_do(void f(Klass*, ClassLoaderData*)); 99 100 void methods_do(void f(Method*)); 101 102 void unlink(BoolObjectClosure* is_alive); 103 void remove_classes_in_error_state(); 104 105 // Classes loaded by the bootstrap loader are always strongly reachable. 106 // If we're not doing class unloading, all classes are strongly reachable. 107 static bool is_strongly_reachable(ClassLoaderData* loader_data, Klass* klass) { 108 assert (klass != NULL, "should have non-null klass"); 109 return (loader_data->is_the_null_class_loader_data() || !ClassUnloading); 110 } 111 112 // Unload (that is, break root links to) all unmarked classes and 113 // loaders. Returns "true" iff something was unloaded. 114 bool 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(oop protection_domain); 130 131 void print(bool details = true); 132 void verify(); 133 }; 134 135 // The following classes can be in dictionary.cpp, but we need these 136 // to be in header file so that SA's vmStructs can access them. 137 class ProtectionDomainCacheEntry : public HashtableEntry<oop, mtClass> { 138 friend class VMStructs; 139 private: 140 // Flag indicating whether this protection domain entry is strongly reachable. 141 // Used during iterating over the system dictionary to remember oops that need 142 // to be updated. 143 bool _strongly_reachable; 144 public: 145 oop protection_domain() { return literal(); } 146 147 void init() { 148 _strongly_reachable = false; 149 } 150 151 ProtectionDomainCacheEntry* next() { 152 return (ProtectionDomainCacheEntry*)HashtableEntry<oop, mtClass>::next(); 153 } 154 155 ProtectionDomainCacheEntry** next_addr() { 156 return (ProtectionDomainCacheEntry**)HashtableEntry<oop, mtClass>::next_addr(); 157 } 158 159 void oops_do(OopClosure* f) { 160 f->do_oop(literal_addr()); 161 } 162 163 void set_strongly_reachable() { _strongly_reachable = true; } 164 bool is_strongly_reachable() { return _strongly_reachable; } 165 void reset_strongly_reachable() { _strongly_reachable = false; } 166 167 void print() PRODUCT_RETURN; 168 void verify(); 169 }; 170 171 // The ProtectionDomainCacheTable contains all protection domain oops. The system 172 // dictionary entries reference its entries instead of having references to oops 173 // directly. 174 // This is used to speed up system dictionary iteration: the oops in the 175 // protection domain are the only ones referring the Java heap. So when there is 176 // need to update these, instead of going over every entry of the system dictionary, 177 // we only need to iterate over this set. 178 // The amount of different protection domains used is typically magnitudes smaller 179 // than the number of system dictionary entries (loaded classes). 180 class ProtectionDomainCacheTable : public Hashtable<oop, mtClass> { 181 friend class VMStructs; 182 private: 183 ProtectionDomainCacheEntry* bucket(int i) { 184 return (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::bucket(i); 185 } 186 187 // The following method is not MT-safe and must be done under lock. 188 ProtectionDomainCacheEntry** bucket_addr(int i) { 189 return (ProtectionDomainCacheEntry**) Hashtable<oop, mtClass>::bucket_addr(i); 190 } 191 192 ProtectionDomainCacheEntry* new_entry(unsigned int hash, oop protection_domain) { 193 ProtectionDomainCacheEntry* entry = (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::new_entry(hash, protection_domain); 194 entry->init(); 195 return entry; 196 } 197 198 static unsigned int compute_hash(oop protection_domain) { 199 return (unsigned int)(protection_domain->identity_hash()); 200 } 201 202 int index_for(oop protection_domain) { 203 return hash_to_index(compute_hash(protection_domain)); 204 } 205 206 ProtectionDomainCacheEntry* add_entry(int index, unsigned int hash, oop protection_domain); 207 ProtectionDomainCacheEntry* find_entry(int index, oop protection_domain); 208 209 public: 210 211 ProtectionDomainCacheTable(int table_size); 212 213 ProtectionDomainCacheEntry* get(oop protection_domain); 214 void free(ProtectionDomainCacheEntry* entry); 215 216 void unlink(BoolObjectClosure* cl); 217 218 // GC support 219 void oops_do(OopClosure* f); 220 void always_strong_oops_do(OopClosure* f); 221 void roots_oops_do(OopClosure* strong, OopClosure* weak); 222 223 static uint bucket_size(); 224 225 void print() PRODUCT_RETURN; 226 void verify(); 227 }; 228 229 230 class ProtectionDomainEntry :public CHeapObj<mtClass> { 231 friend class VMStructs; 232 public: 233 ProtectionDomainEntry* _next; 234 ProtectionDomainCacheEntry* _pd_cache; 235 236 ProtectionDomainEntry(ProtectionDomainCacheEntry* pd_cache, ProtectionDomainEntry* next) { 237 _pd_cache = pd_cache; 238 _next = next; 239 } 240 241 ProtectionDomainEntry* next() { return _next; } 242 oop protection_domain() { return _pd_cache->protection_domain(); } 243 }; 244 245 // An entry in the system dictionary, this describes a class as 246 // { Klass*, loader, protection_domain }. 247 248 class DictionaryEntry : public HashtableEntry<Klass*, mtClass> { 249 friend class VMStructs; 250 private: 251 // Contains the set of approved protection domains that can access 252 // this system dictionary entry. 253 // 254 // This protection domain set is a set of tuples: 255 // 256 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD) 257 // 258 // [Note that C.protection_domain(), which is stored in the java.lang.Class 259 // mirror of C, is NOT the same as PD] 260 // 261 // If such an entry (C, ICL, PD) exists in the table, it means that 262 // it is okay for a class Foo to reference C, where 263 // 264 // Foo.protection_domain() == PD, and 265 // Foo's defining class loader == ICL 266 // 267 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain() 268 // It is essentially a cache to avoid repeated Java up-calls to 269 // ClassLoader.checkPackageAccess(). 270 // 271 ProtectionDomainEntry* _pd_set; 272 ClassLoaderData* _loader_data; 273 274 public: 275 // Tells whether a protection is in the approved set. 276 bool contains_protection_domain(oop protection_domain) const; 277 // Adds a protection domain to the approved set. 278 void add_protection_domain(Dictionary* dict, oop protection_domain); 279 280 Klass* klass() const { return (Klass*)literal(); } 281 Klass** klass_addr() { return (Klass**)literal_addr(); } 282 283 DictionaryEntry* next() const { 284 return (DictionaryEntry*)HashtableEntry<Klass*, mtClass>::next(); 285 } 286 287 DictionaryEntry** next_addr() { 288 return (DictionaryEntry**)HashtableEntry<Klass*, mtClass>::next_addr(); 289 } 290 291 ClassLoaderData* loader_data() const { return _loader_data; } 292 void set_loader_data(ClassLoaderData* loader_data) { _loader_data = loader_data; } 293 294 ProtectionDomainEntry* pd_set() const { return _pd_set; } 295 void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; } 296 297 bool has_protection_domain() { return _pd_set != NULL; } 298 299 // Tells whether the initiating class' protection can access the this _klass 300 bool is_valid_protection_domain(Handle protection_domain) { 301 if (!ProtectionDomainVerification) return true; 302 if (!SystemDictionary::has_checkPackageAccess()) return true; 303 304 return protection_domain() == NULL 305 ? true 306 : contains_protection_domain(protection_domain()); 307 } 308 309 void set_strongly_reachable() { 310 for (ProtectionDomainEntry* current = _pd_set; 311 current != NULL; 312 current = current->_next) { 313 current->_pd_cache->set_strongly_reachable(); 314 } 315 } 316 317 void verify_protection_domain_set() { 318 for (ProtectionDomainEntry* current = _pd_set; 319 current != NULL; 320 current = current->_next) { 321 current->_pd_cache->protection_domain()->verify(); 322 } 323 } 324 325 bool equals(Symbol* class_name, ClassLoaderData* loader_data) const { 326 Klass* klass = (Klass*)literal(); 327 return (InstanceKlass::cast(klass)->name() == class_name && 328 _loader_data == loader_data); 329 } 330 331 void print() { 332 int count = 0; 333 for (ProtectionDomainEntry* current = _pd_set; 334 current != NULL; 335 current = current->_next) { 336 count++; 337 } 338 tty->print_cr("pd set = #%d", count); 339 } 340 }; 341 342 // Entry in a SymbolPropertyTable, mapping a single Symbol* 343 // to a managed and an unmanaged pointer. 344 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> { 345 friend class VMStructs; 346 private: 347 intptr_t _symbol_mode; // secondary key 348 Method* _method; 349 oop _method_type; 350 351 public: 352 Symbol* symbol() const { return literal(); } 353 354 intptr_t symbol_mode() const { return _symbol_mode; } 355 void set_symbol_mode(intptr_t m) { _symbol_mode = m; } 356 357 Method* method() const { return _method; } 358 void set_method(Method* p) { _method = p; } 359 360 oop method_type() const { return _method_type; } 361 oop* method_type_addr() { return &_method_type; } 362 void set_method_type(oop p) { _method_type = p; } 363 364 SymbolPropertyEntry* next() const { 365 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next(); 366 } 367 368 SymbolPropertyEntry** next_addr() { 369 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr(); 370 } 371 372 void print_on(outputStream* st) const { 373 symbol()->print_value_on(st); 374 st->print("/mode="INTX_FORMAT, symbol_mode()); 375 st->print(" -> "); 376 bool printed = false; 377 if (method() != NULL) { 378 method()->print_value_on(st); 379 printed = true; 380 } 381 if (method_type() != NULL) { 382 if (printed) st->print(" and "); 383 st->print(INTPTR_FORMAT, p2i((void *)method_type())); 384 printed = true; 385 } 386 st->print_cr(printed ? "" : "(empty)"); 387 } 388 }; 389 390 // A system-internal mapping of symbols to pointers, both managed 391 // and unmanaged. Used to record the auto-generation of each method 392 // MethodHandle.invoke(S)T, for all signatures (S)T. 393 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> { 394 friend class VMStructs; 395 private: 396 SymbolPropertyEntry* bucket(int i) { 397 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i); 398 } 399 400 // The following method is not MT-safe and must be done under lock. 401 SymbolPropertyEntry** bucket_addr(int i) { 402 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i); 403 } 404 405 void add_entry(int index, SymbolPropertyEntry* new_entry) { 406 ShouldNotReachHere(); 407 } 408 void set_entry(int index, SymbolPropertyEntry* new_entry) { 409 ShouldNotReachHere(); 410 } 411 412 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) { 413 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol); 414 // Hashtable with Symbol* literal must increment and decrement refcount. 415 symbol->increment_refcount(); 416 entry->set_symbol_mode(symbol_mode); 417 entry->set_method(NULL); 418 entry->set_method_type(NULL); 419 return entry; 420 } 421 422 public: 423 SymbolPropertyTable(int table_size); 424 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries); 425 426 void free_entry(SymbolPropertyEntry* entry) { 427 // decrement Symbol refcount here because hashtable doesn't. 428 entry->literal()->decrement_refcount(); 429 Hashtable<Symbol*, mtSymbol>::free_entry(entry); 430 } 431 432 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) { 433 // Use the regular identity_hash. 434 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode; 435 } 436 437 int index_for(Symbol* name, intptr_t symbol_mode) { 438 return hash_to_index(compute_hash(name, symbol_mode)); 439 } 440 441 // need not be locked; no state change 442 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 443 444 // must be done under SystemDictionary_lock 445 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 446 447 // GC support 448 void oops_do(OopClosure* f); 449 450 void methods_do(void f(Method*)); 451 452 // Sharing support 453 void reorder_dictionary(); 454 455 #ifndef PRODUCT 456 void print(); 457 #endif 458 void verify(); 459 }; 460 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP