1 /* 2 * Copyright (c) 2003, 2018, 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 "utilities/hashtable.hpp" 33 #include "utilities/ostream.hpp" 34 35 class DictionaryEntry; 36 class BoolObjectClosure; 37 38 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 39 // The data structure for the class loader data dictionaries (and the shared system 40 // dictionary). 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 void clean_cached_protection_domains(DictionaryEntry* probe); 56 57 protected: 58 static size_t entry_size(); 59 public: 60 Dictionary(ClassLoaderData* loader_data, int table_size, bool resizable = false); 61 Dictionary(ClassLoaderData* loader_data, int table_size, HashtableBucket<mtClass>* t, int number_of_entries, bool resizable = false); 62 ~Dictionary(); 63 64 static bool does_any_dictionary_needs_resizing(); 65 bool resize_if_needed(); 66 67 DictionaryEntry* new_entry(unsigned int hash, InstanceKlass* klass); 68 69 void add_klass(unsigned int hash, Symbol* class_name, InstanceKlass* obj); 70 71 InstanceKlass* find_class(int index, unsigned int hash, Symbol* name); 72 73 InstanceKlass* find_shared_class(int index, unsigned int hash, Symbol* name); 74 75 void classes_do(void f(InstanceKlass*)); 76 void classes_do(void f(InstanceKlass*, TRAPS), TRAPS); 77 void all_entries_do(KlassClosure* closure); 78 void classes_do(MetaspaceClosure* it); 79 80 void unlink(); 81 void remove_classes_in_error_state(); 82 83 // Unload classes whose defining loaders are unloaded 84 void do_unloading(); 85 86 // Protection domains 87 InstanceKlass* find(unsigned int hash, Symbol* name, Handle protection_domain); 88 bool is_valid_protection_domain(unsigned int hash, 89 Symbol* name, 90 Handle protection_domain); 91 void add_protection_domain(int index, unsigned int hash, 92 InstanceKlass* klass, 93 Handle protection_domain, TRAPS); 94 95 // Sharing support 96 void reorder_dictionary_for_sharing() NOT_CDS_RETURN; 97 98 void print_on(outputStream* st) const; 99 void verify(); 100 DictionaryEntry* bucket(int i) const { 101 return (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i); 102 } 103 104 // The following method is not MT-safe and must be done under lock. 105 DictionaryEntry** bucket_addr(int i) { 106 return (DictionaryEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i); 107 } 108 109 void add_entry(int index, DictionaryEntry* new_entry) { 110 Hashtable<InstanceKlass*, mtClass>::add_entry(index, (HashtableEntry<InstanceKlass*, mtClass>*)new_entry); 111 } 112 113 void unlink_entry(DictionaryEntry* entry) { 114 Hashtable<InstanceKlass*, mtClass>::unlink_entry((HashtableEntry<InstanceKlass*, mtClass>*)entry); 115 } 116 117 void free_entry(DictionaryEntry* entry); 118 }; 119 120 // An entry in the class loader data dictionaries, this describes a class as 121 // { InstanceKlass*, protection_domain }. 122 123 class DictionaryEntry : public HashtableEntry<InstanceKlass*, mtClass> { 124 friend class VMStructs; 125 private: 126 // Contains the set of approved protection domains that can access 127 // this dictionary entry. 128 // 129 // This protection domain set is a set of tuples: 130 // 131 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD) 132 // 133 // [Note that C.protection_domain(), which is stored in the java.lang.Class 134 // mirror of C, is NOT the same as PD] 135 // 136 // If such an entry (C, ICL, PD) exists in the table, it means that 137 // it is okay for a class Foo to reference C, where 138 // 139 // Foo.protection_domain() == PD, and 140 // Foo's defining class loader == ICL 141 // 142 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain() 143 // It is essentially a cache to avoid repeated Java up-calls to 144 // ClassLoader.checkPackageAccess(). 145 // 146 ProtectionDomainEntry* volatile _pd_set; 147 148 public: 149 // Tells whether a protection is in the approved set. 150 bool contains_protection_domain(oop protection_domain) const; 151 // Adds a protection domain to the approved set. 152 void add_protection_domain(Dictionary* dict, Handle protection_domain); 153 154 InstanceKlass* instance_klass() const { return literal(); } 155 InstanceKlass** klass_addr() { return (InstanceKlass**)literal_addr(); } 156 157 DictionaryEntry* next() const { 158 return (DictionaryEntry*)HashtableEntry<InstanceKlass*, mtClass>::next(); 159 } 160 161 DictionaryEntry** next_addr() { 162 return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr(); 163 } 164 165 ProtectionDomainEntry* pd_set() const { return _pd_set; } 166 void set_pd_set(ProtectionDomainEntry* new_head) { _pd_set = new_head; } 167 168 ProtectionDomainEntry* pd_set_acquire() const; 169 void release_set_pd_set(ProtectionDomainEntry* new_head); 170 171 // Tells whether the initiating class' protection domain can access the klass in this entry 172 bool is_valid_protection_domain(Handle protection_domain) { 173 if (!ProtectionDomainVerification) return true; 174 if (!SystemDictionary::has_checkPackageAccess()) return true; 175 176 return protection_domain() == NULL 177 ? true 178 : contains_protection_domain(protection_domain()); 179 } 180 181 void verify_protection_domain_set() { 182 for (ProtectionDomainEntry* current = pd_set(); // accessed at a safepoint 183 current != NULL; 184 current = current->_next) { 185 oopDesc::verify(current->_pd_cache->object_no_keepalive()); 186 } 187 } 188 189 bool equals(const Symbol* class_name) const { 190 InstanceKlass* klass = (InstanceKlass*)literal(); 191 return (klass->name() == class_name); 192 } 193 194 void print_count(outputStream *st) { 195 int count = 0; 196 for (ProtectionDomainEntry* current = pd_set(); // accessed inside SD lock 197 current != NULL; 198 current = current->_next) { 199 count++; 200 } 201 st->print_cr("pd set count = #%d", count); 202 } 203 204 void verify(); 205 }; 206 207 // Entry in a SymbolPropertyTable, mapping a single Symbol* 208 // to a managed and an unmanaged pointer. 209 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> { 210 friend class VMStructs; 211 private: 212 intptr_t _symbol_mode; // secondary key 213 Method* _method; 214 oop _method_type; 215 216 public: 217 Symbol* symbol() const { return literal(); } 218 219 intptr_t symbol_mode() const { return _symbol_mode; } 220 void set_symbol_mode(intptr_t m) { _symbol_mode = m; } 221 222 Method* method() const { return _method; } 223 void set_method(Method* p) { _method = p; } 224 225 oop method_type() const { return _method_type; } 226 oop* method_type_addr() { return &_method_type; } 227 void set_method_type(oop p) { _method_type = p; } 228 229 SymbolPropertyEntry* next() const { 230 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next(); 231 } 232 233 SymbolPropertyEntry** next_addr() { 234 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr(); 235 } 236 237 void print_entry(outputStream* st) const { 238 symbol()->print_value_on(st); 239 st->print("/mode=" INTX_FORMAT, symbol_mode()); 240 st->print(" -> "); 241 bool printed = false; 242 if (method() != NULL) { 243 method()->print_value_on(st); 244 printed = true; 245 } 246 if (method_type() != NULL) { 247 if (printed) st->print(" and "); 248 st->print(INTPTR_FORMAT, p2i((void *)method_type())); 249 printed = true; 250 } 251 st->print_cr(printed ? "" : "(empty)"); 252 } 253 }; 254 255 // A system-internal mapping of symbols to pointers, both managed 256 // and unmanaged. Used to record the auto-generation of each method 257 // MethodHandle.invoke(S)T, for all signatures (S)T. 258 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> { 259 friend class VMStructs; 260 private: 261 // The following method is not MT-safe and must be done under lock. 262 SymbolPropertyEntry** bucket_addr(int i) { 263 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i); 264 } 265 266 void add_entry(int index, SymbolPropertyEntry* new_entry) { 267 ShouldNotReachHere(); 268 } 269 void set_entry(int index, SymbolPropertyEntry* new_entry) { 270 ShouldNotReachHere(); 271 } 272 273 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) { 274 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol); 275 // Hashtable with Symbol* literal must increment and decrement refcount. 276 symbol->increment_refcount(); 277 entry->set_symbol_mode(symbol_mode); 278 entry->set_method(NULL); 279 entry->set_method_type(NULL); 280 return entry; 281 } 282 283 public: 284 SymbolPropertyTable(int table_size); 285 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries); 286 287 void free_entry(SymbolPropertyEntry* entry) { 288 // decrement Symbol refcount here because hashtable doesn't. 289 entry->literal()->decrement_refcount(); 290 Hashtable<Symbol*, mtSymbol>::free_entry(entry); 291 } 292 293 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) { 294 // Use the regular identity_hash. 295 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode; 296 } 297 298 int index_for(Symbol* name, intptr_t symbol_mode) { 299 return hash_to_index(compute_hash(name, symbol_mode)); 300 } 301 302 // need not be locked; no state change 303 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 304 305 // must be done under SystemDictionary_lock 306 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode); 307 308 // GC support 309 void oops_do(OopClosure* f); 310 311 void methods_do(void f(Method*)); 312 313 void verify(); 314 315 SymbolPropertyEntry* bucket(int i) { 316 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i); 317 } 318 }; 319 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP