klassVtable.hpp revision 0:a61af66fc99e
1/* 2 * Copyright 1997-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25// A klassVtable abstracts the variable-length vtable that is embedded in instanceKlass 26// and arrayKlass. klassVtable objects are used just as convenient transient accessors to the vtable, 27// not to actually hold the vtable data. 28// Note: the klassVtable should not be accessed before the class has been verified 29// (until that point, the vtable is uninitialized). 30 31// Currently a klassVtable contains a direct reference to the vtable data, and is therefore 32// not preserved across GCs. 33 34class vtableEntry; 35 36class klassVtable : public ResourceObj { 37 KlassHandle _klass; // my klass 38 int _tableOffset; // offset of start of vtable data within klass 39 int _length; // length of vtable (number of entries) 40#ifndef PRODUCT 41 int _verify_count; // to make verify faster 42#endif 43 44 // Ordering important, so greater_than (>) can be used as an merge operator. 45 enum AccessType { 46 acc_private = 0, 47 acc_package_private = 1, 48 acc_publicprotected = 2 49 }; 50 51 public: 52 klassVtable(KlassHandle h_klass, void* base, int length) : _klass(h_klass) { 53 _tableOffset = (address)base - (address)h_klass(); _length = length; 54 } 55 56 // accessors 57 vtableEntry* table() const { return (vtableEntry*)(address(_klass()) + _tableOffset); } 58 KlassHandle klass() const { return _klass; } 59 int length() const { return _length; } 60 inline methodOop method_at(int i) const; 61 inline methodOop unchecked_method_at(int i) const; 62 inline oop* adr_method_at(int i) const; 63 64 // searching; all methods return -1 if not found 65 int index_of(methodOop m) const { return index_of(m, _length); } 66 int index_of_miranda(symbolOop name, symbolOop signature); 67 68 void initialize_vtable(bool checkconstraints, TRAPS); // initialize vtable of a new klass 69 70 // conputes vtable length (in words) and the number of miranda methods 71 static void compute_vtable_size_and_num_mirandas(int &vtable_length, int &num_miranda_methods, 72 klassOop super, objArrayOop methods, 73 AccessFlags class_flags, oop classloader, 74 symbolOop classname, objArrayOop local_interfaces); 75 76 // RedefineClasses() API support: 77 // If any entry of this vtable points to any of old_methods, 78 // replace it with the corresponding new_method. 79 // trace_name_printed is set to true if the current call has 80 // printed the klass name so that other routines in the adjust_* 81 // group don't print the klass name. 82 void adjust_method_entries(methodOop* old_methods, methodOop* new_methods, 83 int methods_length, bool * trace_name_printed); 84 85 // Garbage collection 86 void oop_follow_contents(); 87 void oop_adjust_pointers(); 88 89#ifndef SERIALGC 90 // Parallel Old 91 void oop_follow_contents(ParCompactionManager* cm); 92 void oop_update_pointers(ParCompactionManager* cm); 93 void oop_update_pointers(ParCompactionManager* cm, 94 HeapWord* beg_addr, HeapWord* end_addr); 95#endif // SERIALGC 96 97 // Iterators 98 void oop_oop_iterate(OopClosure* blk); 99 void oop_oop_iterate_m(OopClosure* blk, MemRegion mr); 100 101 // Debugging code 102 void print() PRODUCT_RETURN; 103 void verify(outputStream* st, bool force = false); 104 static void print_statistics() PRODUCT_RETURN; 105 106#ifndef PRODUCT 107 bool check_no_old_entries(); 108 void dump_vtable(); 109#endif 110 111 protected: 112 friend class vtableEntry; 113 private: 114 void copy_vtable_to(vtableEntry* start); 115 int initialize_from_super(KlassHandle super); 116 int index_of(methodOop m, int len) const; // same as index_of, but search only up to len 117 void put_method_at(methodOop m, int index); 118 static bool needs_new_vtable_entry(methodOop m, klassOop super, oop classloader, symbolOop classname, AccessFlags access_flags); 119 AccessType vtable_accessibility_at(int i); 120 121 bool update_super_vtable(instanceKlass* klass, methodHandle target_method, int super_vtable_len, bool checkconstraints, TRAPS); 122 123 // support for miranda methods 124 bool is_miranda_entry_at(int i); 125 void fill_in_mirandas(int& initialized); 126 static bool is_miranda(methodOop m, objArrayOop class_methods, klassOop super); 127 static void add_new_mirandas_to_list(GrowableArray<methodOop>* list_of_current_mirandas, objArrayOop current_interface_methods, objArrayOop class_methods, klassOop super); 128 static void get_mirandas(GrowableArray<methodOop>* mirandas, klassOop super, objArrayOop class_methods, objArrayOop local_interfaces); 129 static int get_num_mirandas(klassOop super, objArrayOop class_methods, objArrayOop local_interfaces); 130 131 132 void verify_against(outputStream* st, klassVtable* vt, int index); 133 inline instanceKlass* ik() const; 134}; 135 136 137// private helper class for klassVtable 138// description of entry points: 139// destination is interpreted: 140// from_compiled_code_entry_point -> c2iadapter 141// from_interpreter_entry_point -> interpreter entry point 142// destination is compiled: 143// from_compiled_code_entry_point -> nmethod entry point 144// from_interpreter_entry_point -> i2cadapter 145class vtableEntry VALUE_OBJ_CLASS_SPEC { 146 public: 147 // size in words 148 static int size() { 149 return sizeof(vtableEntry) / sizeof(HeapWord); 150 } 151 static int method_offset_in_bytes() { return offset_of(vtableEntry, _method); } 152 methodOop method() const { return _method; } 153 154 private: 155 methodOop _method; 156 void set(methodOop method) { assert(method != NULL, "use clear"); _method = method; } 157 void clear() { _method = NULL; } 158 void print() PRODUCT_RETURN; 159 void verify(klassVtable* vt, outputStream* st); 160 161 friend class klassVtable; 162}; 163 164 165inline methodOop klassVtable::method_at(int i) const { 166 assert(i >= 0 && i < _length, "index out of bounds"); 167 assert(table()[i].method() != NULL, "should not be null"); 168 assert(oop(table()[i].method())->is_method(), "should be method"); 169 return table()[i].method(); 170} 171 172inline methodOop klassVtable::unchecked_method_at(int i) const { 173 assert(i >= 0 && i < _length, "index out of bounds"); 174 return table()[i].method(); 175} 176 177inline oop* klassVtable::adr_method_at(int i) const { 178 // Allow one past the last entry to be referenced; useful for loop bounds. 179 assert(i >= 0 && i <= _length, "index out of bounds"); 180 return (oop*)(address(table() + i) + vtableEntry::method_offset_in_bytes()); 181} 182 183// -------------------------------------------------------------------------------- 184class klassItable; 185class itableMethodEntry; 186 187class itableOffsetEntry VALUE_OBJ_CLASS_SPEC { 188 private: 189 klassOop _interface; 190 int _offset; 191 public: 192 klassOop interface_klass() const { return _interface; } 193 int offset() const { return _offset; } 194 195 static itableMethodEntry* method_entry(klassOop k, int offset) { return (itableMethodEntry*)(((address)k) + offset); } 196 itableMethodEntry* first_method_entry(klassOop k) { return method_entry(k, _offset); } 197 198 void initialize(klassOop interf, int offset) { _interface = interf; _offset = offset; } 199 200 // Static size and offset accessors 201 static int size() { return sizeof(itableOffsetEntry) / HeapWordSize; } // size in words 202 static int interface_offset_in_bytes() { return offset_of(itableOffsetEntry, _interface); } 203 static int offset_offset_in_bytes() { return offset_of(itableOffsetEntry, _offset); } 204 205 friend class klassItable; 206}; 207 208 209class itableMethodEntry VALUE_OBJ_CLASS_SPEC { 210 private: 211 methodOop _method; 212 213 public: 214 methodOop method() const { return _method; } 215 216 void clear() { _method = NULL; } 217 218 void initialize(methodOop method); 219 220 // Static size and offset accessors 221 static int size() { return sizeof(itableMethodEntry) / HeapWordSize; } // size in words 222 static int method_offset_in_bytes() { return offset_of(itableMethodEntry, _method); } 223 224 friend class klassItable; 225}; 226 227// 228// Format of an itable 229// 230// ---- offset table --- 231// klassOop of interface 1 \ 232// offset to vtable from start of oop / offset table entry 233// ... 234// klassOop of interface n \ 235// offset to vtable from start of oop / offset table entry 236// --- vtable for interface 1 --- 237// methodOop \ 238// compiler entry point / method table entry 239// ... 240// methodOop \ 241// compiler entry point / method table entry 242// -- vtable for interface 2 --- 243// ... 244// 245class klassItable : public ResourceObj { 246 private: 247 instanceKlassHandle _klass; // my klass 248 int _table_offset; // offset of start of itable data within klass (in words) 249 int _size_offset_table; // size of offset table (in itableOffset entries) 250 int _size_method_table; // size of methodtable (in itableMethodEntry entries) 251 252 void initialize_itable_for_interface(int method_table_offset, KlassHandle interf_h, bool checkconstraints, TRAPS); 253 public: 254 klassItable(instanceKlassHandle klass); 255 256 itableOffsetEntry* offset_entry(int i) { assert(0 <= i && i <= _size_offset_table, "index out of bounds"); 257 return &((itableOffsetEntry*)vtable_start())[i]; } 258 259 itableMethodEntry* method_entry(int i) { assert(0 <= i && i <= _size_method_table, "index out of bounds"); 260 return &((itableMethodEntry*)method_start())[i]; } 261 262 int nof_interfaces() { return _size_offset_table; } 263 264 // Initialization 265 void initialize_itable(bool checkconstraints, TRAPS); 266 267 // Updates 268 void initialize_with_method(methodOop m); 269 270 // RedefineClasses() API support: 271 // if any entry of this itable points to any of old_methods, 272 // replace it with the corresponding new_method. 273 // trace_name_printed is set to true if the current call has 274 // printed the klass name so that other routines in the adjust_* 275 // group don't print the klass name. 276 void adjust_method_entries(methodOop* old_methods, methodOop* new_methods, 277 int methods_length, bool * trace_name_printed); 278 279 // Garbage collection 280 void oop_follow_contents(); 281 void oop_adjust_pointers(); 282 283#ifndef SERIALGC 284 // Parallel Old 285 void oop_follow_contents(ParCompactionManager* cm); 286 void oop_update_pointers(ParCompactionManager* cm); 287 void oop_update_pointers(ParCompactionManager* cm, 288 HeapWord* beg_addr, HeapWord* end_addr); 289#endif // SERIALGC 290 291 // Iterators 292 void oop_oop_iterate(OopClosure* blk); 293 void oop_oop_iterate_m(OopClosure* blk, MemRegion mr); 294 295 // Setup of itable 296 static int compute_itable_size(objArrayHandle transitive_interfaces); 297 static void setup_itable_offset_table(instanceKlassHandle klass); 298 299 // Resolving of method to index 300 static int compute_itable_index(methodOop m); 301 302 // Debugging/Statistics 303 static void print_statistics() PRODUCT_RETURN; 304 private: 305 intptr_t* vtable_start() const { return ((intptr_t*)_klass()) + _table_offset; } 306 intptr_t* method_start() const { return vtable_start() + _size_offset_table * itableOffsetEntry::size(); } 307 308 // Helper methods 309 static int calc_itable_size(int num_interfaces, int num_methods) { return (num_interfaces * itableOffsetEntry::size()) + (num_methods * itableMethodEntry::size()); } 310 311 // Statistics 312 NOT_PRODUCT(static int _total_classes;) // Total no. of classes with itables 313 NOT_PRODUCT(static long _total_size;) // Total no. of bytes used for itables 314 315 static void update_stats(int size) PRODUCT_RETURN NOT_PRODUCT({ _total_classes++; _total_size += size; }) 316}; 317