1 /* 2 * Copyright (c) 2003, 2020, 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_CLASSFILE_DICTIONARY_HPP 26 #define SHARE_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 "oops/oopHandle.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. 41 42 class Dictionary : public Hashtable<InstanceKlass*, mtClass> { 43 friend class VMStructs; 44 45 static bool _some_dictionary_needs_resizing; 46 bool _resizable; 47 bool _needs_resizing; 48 void check_if_needs_resize(); 49 50 ClassLoaderData* _loader_data; // backpointer to owning loader 51 ClassLoaderData* loader_data() const { return _loader_data; } 52 53 DictionaryEntry* get_entry(int index, unsigned int hash, Symbol* name); 54 55 public: 56 Dictionary(ClassLoaderData* loader_data, int table_size, bool resizable = false); 57 Dictionary(ClassLoaderData* loader_data, int table_size, HashtableBucket<mtClass>* t, int number_of_entries, bool resizable = false); 58 ~Dictionary(); 59 60 static bool does_any_dictionary_needs_resizing(); 61 bool resize_if_needed(); 62 63 void add_klass(unsigned int hash, Symbol* class_name, InstanceKlass* obj); 64 // replace the existing class with k, return old class. 65 InstanceKlass* replace_class(int index, unsigned hash, Symbol* class_name, InstanceKlass* k); 66 67 InstanceKlass* find_class(int index, unsigned int hash, Symbol* name); 68 69 void classes_do(void f(InstanceKlass*)); 70 void classes_do(void f(InstanceKlass*, TRAPS), TRAPS); 71 void all_entries_do(KlassClosure* closure); 72 void classes_do(MetaspaceClosure* it); 73 74 void clean_cached_protection_domains(); 75 76 // Protection domains 77 InstanceKlass* find(unsigned int hash, Symbol* name, Handle protection_domain); 78 bool is_valid_protection_domain(unsigned int hash, 79 Symbol* name, 80 Handle protection_domain); 81 void add_protection_domain(int index, unsigned int hash, 82 InstanceKlass* klass, 83 Handle protection_domain, TRAPS); 84 85 void print_on(outputStream* st) const; 86 void verify(); 87 88 private: 89 DictionaryEntry* new_entry(unsigned int hash, InstanceKlass* klass); 90 91 DictionaryEntry* bucket(int i) const { 92 return (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i); 93 } 94 95 // The following method is not MT-safe and must be done under lock. 96 DictionaryEntry** bucket_addr(int i) { 97 return (DictionaryEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i); 98 } 99 100 void add_entry(int index, DictionaryEntry* new_entry) { 101 Hashtable<InstanceKlass*, mtClass>::add_entry(index, (HashtableEntry<InstanceKlass*, mtClass>*)new_entry); 102 } 103 104 void unlink_entry(DictionaryEntry* entry) { 105 Hashtable<InstanceKlass*, mtClass>::unlink_entry((HashtableEntry<InstanceKlass*, mtClass>*)entry); 106 } 107 108 void free_entry(DictionaryEntry* entry); 109 }; 110 111 // An entry in the class loader data dictionaries, this describes a class as 112 // { InstanceKlass*, protection_domain }. 113 114 class DictionaryEntry : public HashtableEntry<InstanceKlass*, mtClass> { 115 friend class VMStructs; 116 private: 117 // Contains the set of approved protection domains that can access 118 // this dictionary entry. 119 // 120 // This protection domain set is a set of tuples: 121 // 122 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD) 123 // 124 // [Note that C.protection_domain(), which is stored in the java.lang.Class 125 // mirror of C, is NOT the same as PD] 126 // 127 // If such an entry (C, ICL, PD) exists in the table, it means that 128 // it is okay for a class Foo to reference C, where 129 // 130 // Foo.protection_domain() == PD, and 131 // Foo's defining class loader == ICL 132 // 133 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain() 134 // It is essentially a cache to avoid repeated Java up-calls to 135 // ClassLoader.checkPackageAccess(). 136 // 137 ProtectionDomainEntry* volatile _pd_set; 138 139 public: 140 // Tells whether a protection is in the approved set. 141 bool contains_protection_domain(oop protection_domain) const; 142 // Adds a protection domain to the approved set. 143 void add_protection_domain(Dictionary* dict, Handle protection_domain); 144 145 InstanceKlass* instance_klass() const { return literal(); } 146 InstanceKlass** klass_addr() { return (InstanceKlass**)literal_addr(); } 147 148 DictionaryEntry* next() const { 149 return (DictionaryEntry*)HashtableEntry<InstanceKlass*, mtClass>::next(); 150 } 151 152 DictionaryEntry** next_addr() { 153 return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr(); 154 } 155 156 ProtectionDomainEntry* pd_set() const { return _pd_set; } 157 void set_pd_set(ProtectionDomainEntry* new_head) { _pd_set = new_head; } 158 159 // Tells whether the initiating class' protection domain can access the klass in this entry 160 bool is_valid_protection_domain(Handle protection_domain) { 161 if (!ProtectionDomainVerification) return true; 162 163 return protection_domain() == NULL 164 ? true 165 : contains_protection_domain(protection_domain()); 166 } 167 168 void verify_protection_domain_set(); 169 170 bool equals(const Symbol* class_name) const { 171 InstanceKlass* klass = (InstanceKlass*)literal(); 172 return (klass->name() == class_name); 173 } 174 175 void print_count(outputStream *st); 176 void verify(); 177 }; 178 179 // Entry in a SymbolPropertyTable, mapping a single Symbol* 180 // to a managed and an unmanaged pointer. 181 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> { 182 friend class VMStructs; 183 private: 184 intptr_t _symbol_mode; // secondary key 185 Method* _method; 186 OopHandle _method_type; 187 188 public: 189 Symbol* symbol() const { return literal(); } 190 191 intptr_t symbol_mode() const { return _symbol_mode; } 192 void set_symbol_mode(intptr_t m) { _symbol_mode = m; } 193 194 Method* method() const { return _method; } 195 void set_method(Method* p) { _method = p; } 196 197 oop method_type() const; 198 void set_method_type(oop p); 199 200 // We need to clear the OopHandle because these hashtable entries are not constructed properly. 201 void clear_method_type() { _method_type = OopHandle(); } 202 203 void free_entry(); 204 205 SymbolPropertyEntry* next() const { 206 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next(); 207 } 208 209 SymbolPropertyEntry** next_addr() { 210 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr(); 211 } 212 213 void print_entry(outputStream* st) const { 214 symbol()->print_value_on(st); 215 st->print("/mode=" INTX_FORMAT, symbol_mode()); 216 st->print(" -> "); 217 bool printed = false; 218 if (method() != NULL) { 219 method()->print_value_on(st); 220 printed = true; 221 } 222 if (method_type() != NULL) { 223 if (printed) st->print(" and "); 224 st->print(INTPTR_FORMAT, p2i((void *)method_type())); 225 printed = true; 226 } 227 st->print_cr(printed ? "" : "(empty)"); 228 } 229 }; 230 231 // A system-internal mapping of symbols to pointers, both managed 232 // and unmanaged. Used to record the auto-generation of each method 233 // MethodHandle.invoke(S)T, for all signatures (S)T. 234 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> { 235 friend class VMStructs; 236 private: 237 // The following method is not MT-safe and must be done under lock. 238 SymbolPropertyEntry** bucket_addr(int i) { 239 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i); 240 } 241 242 void add_entry(int index, SymbolPropertyEntry* new_entry) { 243 ShouldNotReachHere(); 244 } 245 void set_entry(int index, SymbolPropertyEntry* new_entry) { 246 ShouldNotReachHere(); 247 } 248 249 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) { 250 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol); 251 // Hashtable with Symbol* literal must increment and decrement refcount. 252 symbol->increment_refcount(); 253 entry->set_symbol_mode(symbol_mode); 254 entry->set_method(NULL); 255 entry->clear_method_type(); 256 return entry; 257 } 258 259 public: 260 SymbolPropertyTable(int table_size); 261 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries); 262 263 void free_entry(SymbolPropertyEntry* entry); 264 265 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) { 266 // Use the regular identity_hash. 267 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode; 268 } 269 270 int index_for(Symbol* name, intptr_t symbol_mode) { 271 return hash_to_index(compute_hash(name, symbol_mode)); 272 } 273 274 // need not be locked; no state change 275 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 276 277 // must be done under SystemDictionary_lock 278 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 279 280 void methods_do(void f(Method*)); 281 282 void verify(); 283 284 SymbolPropertyEntry* bucket(int i) { 285 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i); 286 } 287 }; 288 #endif // SHARE_CLASSFILE_DICTIONARY_HPP