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); 103 104 // Classes loaded by the bootstrap loader are always strongly reachable. 105 // If we're not doing class unloading, all classes are strongly reachable. 106 static bool is_strongly_reachable(ClassLoaderData* loader_data, Klass* klass) { 107 assert (klass != NULL, "should have non-null klass"); 108 return (loader_data->is_the_null_class_loader_data() || !ClassUnloading); 109 } 110 111 // Unload (that is, break root links to) all unmarked classes and 112 // loaders. Returns "true" iff something was unloaded. 113 bool 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 #ifndef PRODUCT 131 void print(); 132 #endif 133 void verify(); 134 }; 135 136 // The following classes can be in dictionary.cpp, but we need these 137 // to be in header file so that SA's vmStructs can access them. 138 class ProtectionDomainCacheEntry : public HashtableEntry<oop, mtClass> { 139 friend class VMStructs; 140 private: 141 // Flag indicating whether this protection domain entry is strongly reachable. 142 // Used during iterating over the system dictionary to remember oops that need 143 // to be updated. 144 bool _strongly_reachable; 145 public: 146 oop protection_domain() { return literal(); } 147 148 void init() { 149 _strongly_reachable = false; 150 } 151 152 ProtectionDomainCacheEntry* next() { 153 return (ProtectionDomainCacheEntry*)HashtableEntry<oop, mtClass>::next(); 154 } 155 156 ProtectionDomainCacheEntry** next_addr() { 157 return (ProtectionDomainCacheEntry**)HashtableEntry<oop, mtClass>::next_addr(); 158 } 159 160 void oops_do(OopClosure* f) { 161 f->do_oop(literal_addr()); 162 } 163 164 void set_strongly_reachable() { _strongly_reachable = true; } 165 bool is_strongly_reachable() { return _strongly_reachable; } 166 void reset_strongly_reachable() { _strongly_reachable = false; } 167 168 void print() PRODUCT_RETURN; 169 void verify(); 170 }; 171 172 // The ProtectionDomainCacheTable contains all protection domain oops. The system 173 // dictionary entries reference its entries instead of having references to oops 174 // directly. 175 // This is used to speed up system dictionary iteration: the oops in the 176 // protection domain are the only ones referring the Java heap. So when there is 177 // need to update these, instead of going over every entry of the system dictionary, 178 // we only need to iterate over this set. 179 // The amount of different protection domains used is typically magnitudes smaller 180 // than the number of system dictionary entries (loaded classes). 181 class ProtectionDomainCacheTable : public Hashtable<oop, mtClass> { 182 friend class VMStructs; 183 private: 184 ProtectionDomainCacheEntry* bucket(int i) { 185 return (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::bucket(i); 186 } 187 188 // The following method is not MT-safe and must be done under lock. 189 ProtectionDomainCacheEntry** bucket_addr(int i) { 190 return (ProtectionDomainCacheEntry**) Hashtable<oop, mtClass>::bucket_addr(i); 191 } 192 193 ProtectionDomainCacheEntry* new_entry(unsigned int hash, oop protection_domain) { 194 ProtectionDomainCacheEntry* entry = (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::new_entry(hash, protection_domain); 195 entry->init(); 196 return entry; 197 } 198 199 static unsigned int compute_hash(oop protection_domain) { 200 return (unsigned int)(protection_domain->identity_hash()); 201 } 202 203 int index_for(oop protection_domain) { 204 return hash_to_index(compute_hash(protection_domain)); 205 } 206 207 ProtectionDomainCacheEntry* add_entry(int index, unsigned int hash, oop protection_domain); 208 ProtectionDomainCacheEntry* find_entry(int index, oop protection_domain); 209 210 public: 211 212 ProtectionDomainCacheTable(int table_size); 213 214 ProtectionDomainCacheEntry* get(oop protection_domain); 215 void free(ProtectionDomainCacheEntry* entry); 216 217 void unlink(BoolObjectClosure* cl); 218 219 // GC support 220 void oops_do(OopClosure* f); 221 void always_strong_oops_do(OopClosure* f); 222 void roots_oops_do(OopClosure* strong, OopClosure* weak); 223 224 static uint bucket_size(); 225 226 void print() PRODUCT_RETURN; 227 void verify(); 228 }; 229 230 231 class ProtectionDomainEntry :public CHeapObj<mtClass> { 232 friend class VMStructs; 233 public: 234 ProtectionDomainEntry* _next; 235 ProtectionDomainCacheEntry* _pd_cache; 236 237 ProtectionDomainEntry(ProtectionDomainCacheEntry* pd_cache, ProtectionDomainEntry* next) { 238 _pd_cache = pd_cache; 239 _next = next; 240 } 241 242 ProtectionDomainEntry* next() { return _next; } 243 oop protection_domain() { return _pd_cache->protection_domain(); } 244 }; 245 246 // An entry in the system dictionary, this describes a class as 247 // { Klass*, loader, protection_domain }. 248 249 class DictionaryEntry : public HashtableEntry<Klass*, mtClass> { 250 friend class VMStructs; 251 private: 252 // Contains the set of approved protection domains that can access 253 // this system dictionary entry. 254 // 255 // This protection domain set is a set of tuples: 256 // 257 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD) 258 // 259 // [Note that C.protection_domain(), which is stored in the java.lang.Class 260 // mirror of C, is NOT the same as PD] 261 // 262 // If such an entry (C, ICL, PD) exists in the table, it means that 263 // it is okay for a class Foo to reference C, where 264 // 265 // Foo.protection_domain() == PD, and 266 // Foo's defining class loader == ICL 267 // 268 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain() 269 // It is essentially a cache to avoid repeated Java up-calls to 270 // ClassLoader.checkPackageAccess(). 271 // 272 ProtectionDomainEntry* _pd_set; 273 ClassLoaderData* _loader_data; 274 275 public: 276 // Tells whether a protection is in the approved set. 277 bool contains_protection_domain(oop protection_domain) const; 278 // Adds a protection domain to the approved set. 279 void add_protection_domain(Dictionary* dict, oop protection_domain); 280 281 Klass* klass() const { return (Klass*)literal(); } 282 Klass** klass_addr() { return (Klass**)literal_addr(); } 283 284 DictionaryEntry* next() const { 285 return (DictionaryEntry*)HashtableEntry<Klass*, mtClass>::next(); 286 } 287 288 DictionaryEntry** next_addr() { 289 return (DictionaryEntry**)HashtableEntry<Klass*, mtClass>::next_addr(); 290 } 291 292 ClassLoaderData* loader_data() const { return _loader_data; } 293 void set_loader_data(ClassLoaderData* loader_data) { _loader_data = loader_data; } 294 295 ProtectionDomainEntry* pd_set() const { return _pd_set; } 296 void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; } 297 298 bool has_protection_domain() { return _pd_set != NULL; } 299 300 // Tells whether the initiating class' protection can access the this _klass 301 bool is_valid_protection_domain(Handle protection_domain) { 302 if (!ProtectionDomainVerification) return true; 303 if (!SystemDictionary::has_checkPackageAccess()) return true; 304 305 return protection_domain() == NULL 306 ? true 307 : contains_protection_domain(protection_domain()); 308 } 309 310 void set_strongly_reachable() { 311 for (ProtectionDomainEntry* current = _pd_set; 312 current != NULL; 313 current = current->_next) { 314 current->_pd_cache->set_strongly_reachable(); 315 } 316 } 317 318 void verify_protection_domain_set() { 319 for (ProtectionDomainEntry* current = _pd_set; 320 current != NULL; 321 current = current->_next) { 322 current->_pd_cache->protection_domain()->verify(); 323 } 324 } 325 326 bool equals(Symbol* class_name, ClassLoaderData* loader_data) const { 327 Klass* klass = (Klass*)literal(); 328 return (InstanceKlass::cast(klass)->name() == class_name && 329 _loader_data == loader_data); 330 } 331 332 void print() { 333 int count = 0; 334 for (ProtectionDomainEntry* current = _pd_set; 335 current != NULL; 336 current = current->_next) { 337 count++; 338 } 339 tty->print_cr("pd set = #%d", count); 340 } 341 }; 342 343 // Entry in a SymbolPropertyTable, mapping a single Symbol* 344 // to a managed and an unmanaged pointer. 345 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> { 346 friend class VMStructs; 347 private: 348 intptr_t _symbol_mode; // secondary key 349 Method* _method; 350 oop _method_type; 351 352 public: 353 Symbol* symbol() const { return literal(); } 354 355 intptr_t symbol_mode() const { return _symbol_mode; } 356 void set_symbol_mode(intptr_t m) { _symbol_mode = m; } 357 358 Method* method() const { return _method; } 359 void set_method(Method* p) { _method = p; } 360 361 oop method_type() const { return _method_type; } 362 oop* method_type_addr() { return &_method_type; } 363 void set_method_type(oop p) { _method_type = p; } 364 365 SymbolPropertyEntry* next() const { 366 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next(); 367 } 368 369 SymbolPropertyEntry** next_addr() { 370 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr(); 371 } 372 373 void print_on(outputStream* st) const { 374 symbol()->print_value_on(st); 375 st->print("/mode="INTX_FORMAT, symbol_mode()); 376 st->print(" -> "); 377 bool printed = false; 378 if (method() != NULL) { 379 method()->print_value_on(st); 380 printed = true; 381 } 382 if (method_type() != NULL) { 383 if (printed) st->print(" and "); 384 st->print(INTPTR_FORMAT, p2i((void *)method_type())); 385 printed = true; 386 } 387 st->print_cr(printed ? "" : "(empty)"); 388 } 389 }; 390 391 // A system-internal mapping of symbols to pointers, both managed 392 // and unmanaged. Used to record the auto-generation of each method 393 // MethodHandle.invoke(S)T, for all signatures (S)T. 394 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> { 395 friend class VMStructs; 396 private: 397 SymbolPropertyEntry* bucket(int i) { 398 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i); 399 } 400 401 // The following method is not MT-safe and must be done under lock. 402 SymbolPropertyEntry** bucket_addr(int i) { 403 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i); 404 } 405 406 void add_entry(int index, SymbolPropertyEntry* new_entry) { 407 ShouldNotReachHere(); 408 } 409 void set_entry(int index, SymbolPropertyEntry* new_entry) { 410 ShouldNotReachHere(); 411 } 412 413 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) { 414 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol); 415 // Hashtable with Symbol* literal must increment and decrement refcount. 416 symbol->increment_refcount(); 417 entry->set_symbol_mode(symbol_mode); 418 entry->set_method(NULL); 419 entry->set_method_type(NULL); 420 return entry; 421 } 422 423 public: 424 SymbolPropertyTable(int table_size); 425 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries); 426 427 void free_entry(SymbolPropertyEntry* entry) { 428 // decrement Symbol refcount here because hashtable doesn't. 429 entry->literal()->decrement_refcount(); 430 Hashtable<Symbol*, mtSymbol>::free_entry(entry); 431 } 432 433 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) { 434 // Use the regular identity_hash. 435 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode; 436 } 437 438 int index_for(Symbol* name, intptr_t symbol_mode) { 439 return hash_to_index(compute_hash(name, symbol_mode)); 440 } 441 442 // need not be locked; no state change 443 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 444 445 // must be done under SystemDictionary_lock 446 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 447 448 // GC support 449 void oops_do(OopClosure* f); 450 451 void methods_do(void f(Method*)); 452 453 // Sharing support 454 void reorder_dictionary(); 455 456 #ifndef PRODUCT 457 void print(); 458 #endif 459 void verify(); 460 }; 461 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP