1 /* 2 * Copyright (c) 2003, 2015, 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.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 loaders. 113 void do_unloading(); 114 115 // Protection domains 116 Klass* find(int index, unsigned int hash, Symbol* name, 117 ClassLoaderData* loader_data, Handle protection_domain, TRAPS); 118 bool is_valid_protection_domain(int index, unsigned int hash, 119 Symbol* name, ClassLoaderData* loader_data, 120 Handle protection_domain); 121 void add_protection_domain(int index, unsigned int hash, 122 instanceKlassHandle klass, ClassLoaderData* loader_data, 123 Handle protection_domain, TRAPS); 124 125 // Sharing support 126 void reorder_dictionary(); 127 128 ProtectionDomainCacheEntry* cache_get(oop protection_domain); 129 130 void print(bool details = true); 131 void verify(); 132 }; 133 134 // The following classes can be in dictionary.cpp, but we need these 135 // to be in header file so that SA's vmStructs can access them. 136 class ProtectionDomainCacheEntry : public HashtableEntry<oop, mtClass> { 137 friend class VMStructs; 138 private: 139 // Flag indicating whether this protection domain entry is strongly reachable. 140 // Used during iterating over the system dictionary to remember oops that need 141 // to be updated. 142 bool _strongly_reachable; 143 public: 144 oop protection_domain() { return literal(); } 145 146 void init() { 147 _strongly_reachable = false; 148 } 149 150 ProtectionDomainCacheEntry* next() { 151 return (ProtectionDomainCacheEntry*)HashtableEntry<oop, mtClass>::next(); 152 } 153 154 ProtectionDomainCacheEntry** next_addr() { 155 return (ProtectionDomainCacheEntry**)HashtableEntry<oop, mtClass>::next_addr(); 156 } 157 158 void oops_do(OopClosure* f) { 159 f->do_oop(literal_addr()); 160 } 161 162 void set_strongly_reachable() { _strongly_reachable = true; } 163 bool is_strongly_reachable() { return _strongly_reachable; } 164 void reset_strongly_reachable() { _strongly_reachable = false; } 165 166 void print() PRODUCT_RETURN; 167 void verify(); 168 }; 169 170 // The ProtectionDomainCacheTable contains all protection domain oops. The system 171 // dictionary entries reference its entries instead of having references to oops 172 // directly. 173 // This is used to speed up system dictionary iteration: the oops in the 174 // protection domain are the only ones referring the Java heap. So when there is 175 // need to update these, instead of going over every entry of the system dictionary, 176 // we only need to iterate over this set. 177 // The amount of different protection domains used is typically magnitudes smaller 178 // than the number of system dictionary entries (loaded classes). 179 class ProtectionDomainCacheTable : public Hashtable<oop, mtClass> { 180 friend class VMStructs; 181 private: 182 ProtectionDomainCacheEntry* bucket(int i) { 183 return (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::bucket(i); 184 } 185 186 // The following method is not MT-safe and must be done under lock. 187 ProtectionDomainCacheEntry** bucket_addr(int i) { 188 return (ProtectionDomainCacheEntry**) Hashtable<oop, mtClass>::bucket_addr(i); 189 } 190 191 ProtectionDomainCacheEntry* new_entry(unsigned int hash, oop protection_domain) { 192 ProtectionDomainCacheEntry* entry = (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::new_entry(hash, protection_domain); 193 entry->init(); 194 return entry; 195 } 196 197 static unsigned int compute_hash(oop protection_domain) { 198 return (unsigned int)(protection_domain->identity_hash()); 199 } 200 201 int index_for(oop protection_domain) { 202 return hash_to_index(compute_hash(protection_domain)); 203 } 204 205 ProtectionDomainCacheEntry* add_entry(int index, unsigned int hash, oop protection_domain); 206 ProtectionDomainCacheEntry* find_entry(int index, oop protection_domain); 207 208 public: 209 210 ProtectionDomainCacheTable(int table_size); 211 212 ProtectionDomainCacheEntry* get(oop protection_domain); 213 void free(ProtectionDomainCacheEntry* entry); 214 215 void unlink(BoolObjectClosure* cl); 216 217 // GC support 218 void oops_do(OopClosure* f); 219 void always_strong_oops_do(OopClosure* f); 220 void roots_oops_do(OopClosure* strong, OopClosure* weak); 221 222 static uint bucket_size(); 223 224 void print() PRODUCT_RETURN; 225 void verify(); 226 }; 227 228 229 class ProtectionDomainEntry :public CHeapObj<mtClass> { 230 friend class VMStructs; 231 public: 232 ProtectionDomainEntry* _next; 233 ProtectionDomainCacheEntry* _pd_cache; 234 235 ProtectionDomainEntry(ProtectionDomainCacheEntry* pd_cache, ProtectionDomainEntry* next) { 236 _pd_cache = pd_cache; 237 _next = next; 238 } 239 240 ProtectionDomainEntry* next() { return _next; } 241 oop protection_domain() { return _pd_cache->protection_domain(); } 242 }; 243 244 // An entry in the system dictionary, this describes a class as 245 // { Klass*, loader, protection_domain }. 246 247 class DictionaryEntry : public HashtableEntry<Klass*, mtClass> { 248 friend class VMStructs; 249 private: 250 // Contains the set of approved protection domains that can access 251 // this system dictionary entry. 252 // 253 // This protection domain set is a set of tuples: 254 // 255 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD) 256 // 257 // [Note that C.protection_domain(), which is stored in the java.lang.Class 258 // mirror of C, is NOT the same as PD] 259 // 260 // If such an entry (C, ICL, PD) exists in the table, it means that 261 // it is okay for a class Foo to reference C, where 262 // 263 // Foo.protection_domain() == PD, and 264 // Foo's defining class loader == ICL 265 // 266 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain() 267 // It is essentially a cache to avoid repeated Java up-calls to 268 // ClassLoader.checkPackageAccess(). 269 // 270 ProtectionDomainEntry* _pd_set; 271 ClassLoaderData* _loader_data; 272 273 public: 274 // Tells whether a protection is in the approved set. 275 bool contains_protection_domain(oop protection_domain) const; 276 // Adds a protection domain to the approved set. 277 void add_protection_domain(Dictionary* dict, oop protection_domain); 278 279 Klass* klass() const { return (Klass*)literal(); } 280 Klass** klass_addr() { return (Klass**)literal_addr(); } 281 282 DictionaryEntry* next() const { 283 return (DictionaryEntry*)HashtableEntry<Klass*, mtClass>::next(); 284 } 285 286 DictionaryEntry** next_addr() { 287 return (DictionaryEntry**)HashtableEntry<Klass*, mtClass>::next_addr(); 288 } 289 290 ClassLoaderData* loader_data() const { return _loader_data; } 291 void set_loader_data(ClassLoaderData* loader_data) { _loader_data = loader_data; } 292 293 ProtectionDomainEntry* pd_set() const { return _pd_set; } 294 void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; } 295 296 bool has_protection_domain() { return _pd_set != NULL; } 297 298 // Tells whether the initiating class' protection can access the this _klass 299 bool is_valid_protection_domain(Handle protection_domain) { 300 if (!ProtectionDomainVerification) return true; 301 if (!SystemDictionary::has_checkPackageAccess()) return true; 302 303 return protection_domain() == NULL 304 ? true 305 : contains_protection_domain(protection_domain()); 306 } 307 308 void set_strongly_reachable() { 309 for (ProtectionDomainEntry* current = _pd_set; 310 current != NULL; 311 current = current->_next) { 312 current->_pd_cache->set_strongly_reachable(); 313 } 314 } 315 316 void verify_protection_domain_set() { 317 for (ProtectionDomainEntry* current = _pd_set; 318 current != NULL; 319 current = current->_next) { 320 current->_pd_cache->protection_domain()->verify(); 321 } 322 } 323 324 bool equals(Symbol* class_name, ClassLoaderData* loader_data) const { 325 Klass* klass = (Klass*)literal(); 326 return (InstanceKlass::cast(klass)->name() == class_name && 327 _loader_data == loader_data); 328 } 329 330 void print() { 331 int count = 0; 332 for (ProtectionDomainEntry* current = _pd_set; 333 current != NULL; 334 current = current->_next) { 335 count++; 336 } 337 tty->print_cr("pd set = #%d", count); 338 } 339 }; 340 341 // Entry in a SymbolPropertyTable, mapping a single Symbol* 342 // to a managed and an unmanaged pointer. 343 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> { 344 friend class VMStructs; 345 private: 346 intptr_t _symbol_mode; // secondary key 347 Method* _method; 348 oop _method_type; 349 350 public: 351 Symbol* symbol() const { return literal(); } 352 353 intptr_t symbol_mode() const { return _symbol_mode; } 354 void set_symbol_mode(intptr_t m) { _symbol_mode = m; } 355 356 Method* method() const { return _method; } 357 void set_method(Method* p) { _method = p; } 358 359 oop method_type() const { return _method_type; } 360 oop* method_type_addr() { return &_method_type; } 361 void set_method_type(oop p) { _method_type = p; } 362 363 SymbolPropertyEntry* next() const { 364 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next(); 365 } 366 367 SymbolPropertyEntry** next_addr() { 368 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr(); 369 } 370 371 void print_on(outputStream* st) const { 372 symbol()->print_value_on(st); 373 st->print("/mode="INTX_FORMAT, symbol_mode()); 374 st->print(" -> "); 375 bool printed = false; 376 if (method() != NULL) { 377 method()->print_value_on(st); 378 printed = true; 379 } 380 if (method_type() != NULL) { 381 if (printed) st->print(" and "); 382 st->print(INTPTR_FORMAT, p2i((void *)method_type())); 383 printed = true; 384 } 385 st->print_cr(printed ? "" : "(empty)"); 386 } 387 }; 388 389 // A system-internal mapping of symbols to pointers, both managed 390 // and unmanaged. Used to record the auto-generation of each method 391 // MethodHandle.invoke(S)T, for all signatures (S)T. 392 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> { 393 friend class VMStructs; 394 private: 395 SymbolPropertyEntry* bucket(int i) { 396 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i); 397 } 398 399 // The following method is not MT-safe and must be done under lock. 400 SymbolPropertyEntry** bucket_addr(int i) { 401 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i); 402 } 403 404 void add_entry(int index, SymbolPropertyEntry* new_entry) { 405 ShouldNotReachHere(); 406 } 407 void set_entry(int index, SymbolPropertyEntry* new_entry) { 408 ShouldNotReachHere(); 409 } 410 411 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) { 412 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol); 413 // Hashtable with Symbol* literal must increment and decrement refcount. 414 symbol->increment_refcount(); 415 entry->set_symbol_mode(symbol_mode); 416 entry->set_method(NULL); 417 entry->set_method_type(NULL); 418 return entry; 419 } 420 421 public: 422 SymbolPropertyTable(int table_size); 423 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries); 424 425 void free_entry(SymbolPropertyEntry* entry) { 426 // decrement Symbol refcount here because hashtable doesn't. 427 entry->literal()->decrement_refcount(); 428 Hashtable<Symbol*, mtSymbol>::free_entry(entry); 429 } 430 431 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) { 432 // Use the regular identity_hash. 433 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode; 434 } 435 436 int index_for(Symbol* name, intptr_t symbol_mode) { 437 return hash_to_index(compute_hash(name, symbol_mode)); 438 } 439 440 // need not be locked; no state change 441 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 442 443 // must be done under SystemDictionary_lock 444 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 445 446 // GC support 447 void oops_do(OopClosure* f); 448 449 void methods_do(void f(Method*)); 450 451 // Sharing support 452 void reorder_dictionary(); 453 454 #ifndef PRODUCT 455 void print(); 456 #endif 457 void verify(); 458 }; 459 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP