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. 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/protectionDomainCache.hpp" 29 #include "classfile/systemDictionary.hpp" 30 #include "oops/instanceKlass.hpp" 31 #include "oops/oop.hpp" 32 #include "runtime/orderAccess.hpp" 33 #include "utilities/hashtable.hpp" 34 #include "utilities/ostream.hpp" 35 36 class DictionaryEntry; 37 class BoolObjectClosure; 38 39 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 40 // The data structure for the class loader data dictionaries (and the shared system 41 // dictionary). 42 43 class Dictionary : public Hashtable<InstanceKlass*, mtClass> { 44 friend class VMStructs; 45 46 ClassLoaderData* _loader_data; // backpointer to owning loader 47 ClassLoaderData* loader_data() const { return _loader_data; } 48 49 DictionaryEntry* get_entry(int index, unsigned int hash, Symbol* name); 50 51 protected: 52 static size_t entry_size(); 53 public: 54 Dictionary(ClassLoaderData* loader_data, int table_size); 55 Dictionary(ClassLoaderData* loader_data, int table_size, HashtableBucket<mtClass>* t, int number_of_entries); 56 ~Dictionary(); 57 58 DictionaryEntry* new_entry(unsigned int hash, InstanceKlass* klass); 59 60 void add_klass(int index, unsigned int hash, Symbol* class_name, InstanceKlass* obj); 61 62 InstanceKlass* find_class(int index, unsigned int hash, Symbol* name); 63 64 InstanceKlass* find_shared_class(int index, unsigned int hash, Symbol* name); 65 66 // GC support 67 void oops_do(OopClosure* f); 68 void roots_oops_do(OopClosure* strong, OopClosure* weak); 69 70 void classes_do(void f(InstanceKlass*)); 71 void classes_do(void f(InstanceKlass*, TRAPS), TRAPS); 72 void all_entries_do(void f(InstanceKlass*, ClassLoaderData*)); 73 void classes_do(MetaspaceClosure* it); 74 75 void unlink(BoolObjectClosure* is_alive); 76 void remove_classes_in_error_state(); 77 78 // Unload classes whose defining loaders are unloaded 79 void do_unloading(); 80 81 // Protection domains 82 InstanceKlass* find(int index, unsigned int hash, Symbol* name, Handle protection_domain); 83 bool is_valid_protection_domain(int index, unsigned int hash, 84 Symbol* name, 85 Handle protection_domain); 86 void add_protection_domain(int index, unsigned int hash, 87 InstanceKlass* klass, 88 Handle protection_domain, TRAPS); 89 90 // Sharing support 91 void reorder_dictionary_for_sharing(); 92 93 void print_on(outputStream* st) const; 94 void verify(); 95 DictionaryEntry* bucket(int i) const { 96 return (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i); 97 } 98 99 // The following method is not MT-safe and must be done under lock. 100 DictionaryEntry** bucket_addr(int i) { 101 return (DictionaryEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i); 102 } 103 104 void add_entry(int index, DictionaryEntry* new_entry) { 105 Hashtable<InstanceKlass*, mtClass>::add_entry(index, (HashtableEntry<InstanceKlass*, mtClass>*)new_entry); 106 } 107 108 void unlink_entry(DictionaryEntry* entry) { 109 Hashtable<InstanceKlass*, mtClass>::unlink_entry((HashtableEntry<InstanceKlass*, mtClass>*)entry); 110 } 111 112 void free_entry(DictionaryEntry* entry); 113 }; 114 115 // An entry in the class loader data dictionaries, this describes a class as 116 // { InstanceKlass*, protection_domain }. 117 118 class DictionaryEntry : public HashtableEntry<InstanceKlass*, mtClass> { 119 friend class VMStructs; 120 private: 121 // Contains the set of approved protection domains that can access 122 // this dictionary entry. 123 // 124 // This protection domain set is a set of tuples: 125 // 126 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD) 127 // 128 // [Note that C.protection_domain(), which is stored in the java.lang.Class 129 // mirror of C, is NOT the same as PD] 130 // 131 // If such an entry (C, ICL, PD) exists in the table, it means that 132 // it is okay for a class Foo to reference C, where 133 // 134 // Foo.protection_domain() == PD, and 135 // Foo's defining class loader == ICL 136 // 137 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain() 138 // It is essentially a cache to avoid repeated Java up-calls to 139 // ClassLoader.checkPackageAccess(). 140 // 141 ProtectionDomainEntry* volatile _pd_set; 142 143 public: 144 // Tells whether a protection is in the approved set. 145 bool contains_protection_domain(oop protection_domain) const; 146 // Adds a protection domain to the approved set. 147 void add_protection_domain(Dictionary* dict, Handle protection_domain); 148 149 InstanceKlass* instance_klass() const { return literal(); } 150 InstanceKlass** klass_addr() { return (InstanceKlass**)literal_addr(); } 151 152 DictionaryEntry* next() const { 153 return (DictionaryEntry*)HashtableEntry<InstanceKlass*, mtClass>::next(); 154 } 155 156 DictionaryEntry** next_addr() { 157 return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr(); 158 } 159 160 ProtectionDomainEntry* pd_set() const { return _pd_set; } 161 void set_pd_set(ProtectionDomainEntry* new_head) { _pd_set = new_head; } 162 163 ProtectionDomainEntry* pd_set_acquire() const { 164 return (ProtectionDomainEntry*)OrderAccess::load_ptr_acquire(&_pd_set); 165 } 166 void release_set_pd_set(ProtectionDomainEntry* new_head) { 167 OrderAccess::release_store_ptr(&_pd_set, new_head); 168 } 169 170 // Tells whether the initiating class' protection domain can access the klass in this entry 171 bool is_valid_protection_domain(Handle protection_domain) { 172 if (!ProtectionDomainVerification) return true; 173 if (!SystemDictionary::has_checkPackageAccess()) return true; 174 175 return protection_domain() == NULL 176 ? true 177 : contains_protection_domain(protection_domain()); 178 } 179 180 void verify_protection_domain_set() { 181 for (ProtectionDomainEntry* current = pd_set(); // accessed at a safepoint 182 current != NULL; 183 current = current->_next) { 184 current->_pd_cache->protection_domain()->verify(); 185 } 186 } 187 188 bool equals(const Symbol* class_name) const { 189 InstanceKlass* klass = (InstanceKlass*)literal(); 190 return (klass->name() == class_name); 191 } 192 193 void print_count(outputStream *st) { 194 int count = 0; 195 for (ProtectionDomainEntry* current = pd_set(); // accessed inside SD lock 196 current != NULL; 197 current = current->_next) { 198 count++; 199 } 200 st->print_cr("pd set count = #%d", count); 201 } 202 203 void verify(); 204 }; 205 206 // Entry in a SymbolPropertyTable, mapping a single Symbol* 207 // to a managed and an unmanaged pointer. 208 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> { 209 friend class VMStructs; 210 private: 211 intptr_t _symbol_mode; // secondary key 212 Method* _method; 213 oop _method_type; 214 215 public: 216 Symbol* symbol() const { return literal(); } 217 218 intptr_t symbol_mode() const { return _symbol_mode; } 219 void set_symbol_mode(intptr_t m) { _symbol_mode = m; } 220 221 Method* method() const { return _method; } 222 void set_method(Method* p) { _method = p; } 223 224 oop method_type() const { return _method_type; } 225 oop* method_type_addr() { return &_method_type; } 226 void set_method_type(oop p) { _method_type = p; } 227 228 SymbolPropertyEntry* next() const { 229 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next(); 230 } 231 232 SymbolPropertyEntry** next_addr() { 233 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr(); 234 } 235 236 void print_entry(outputStream* st) const { 237 symbol()->print_value_on(st); 238 st->print("/mode=" INTX_FORMAT, symbol_mode()); 239 st->print(" -> "); 240 bool printed = false; 241 if (method() != NULL) { 242 method()->print_value_on(st); 243 printed = true; 244 } 245 if (method_type() != NULL) { 246 if (printed) st->print(" and "); 247 st->print(INTPTR_FORMAT, p2i((void *)method_type())); 248 printed = true; 249 } 250 st->print_cr(printed ? "" : "(empty)"); 251 } 252 }; 253 254 // A system-internal mapping of symbols to pointers, both managed 255 // and unmanaged. Used to record the auto-generation of each method 256 // MethodHandle.invoke(S)T, for all signatures (S)T. 257 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> { 258 friend class VMStructs; 259 private: 260 // The following method is not MT-safe and must be done under lock. 261 SymbolPropertyEntry** bucket_addr(int i) { 262 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i); 263 } 264 265 void add_entry(int index, SymbolPropertyEntry* new_entry) { 266 ShouldNotReachHere(); 267 } 268 void set_entry(int index, SymbolPropertyEntry* new_entry) { 269 ShouldNotReachHere(); 270 } 271 272 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) { 273 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol); 274 // Hashtable with Symbol* literal must increment and decrement refcount. 275 symbol->increment_refcount(); 276 entry->set_symbol_mode(symbol_mode); 277 entry->set_method(NULL); 278 entry->set_method_type(NULL); 279 return entry; 280 } 281 282 public: 283 SymbolPropertyTable(int table_size); 284 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries); 285 286 void free_entry(SymbolPropertyEntry* entry) { 287 // decrement Symbol refcount here because hashtable doesn't. 288 entry->literal()->decrement_refcount(); 289 Hashtable<Symbol*, mtSymbol>::free_entry(entry); 290 } 291 292 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) { 293 // Use the regular identity_hash. 294 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode; 295 } 296 297 int index_for(Symbol* name, intptr_t symbol_mode) { 298 return hash_to_index(compute_hash(name, symbol_mode)); 299 } 300 301 // need not be locked; no state change 302 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 303 304 // must be done under SystemDictionary_lock 305 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 306 307 // GC support 308 void oops_do(OopClosure* f); 309 310 void methods_do(void f(Method*)); 311 312 void verify(); 313 314 SymbolPropertyEntry* bucket(int i) { 315 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i); 316 } 317 }; 318 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP