klassVtable.hpp revision 2062:3582bf76420e
1/* 2 * Copyright (c) 1997, 2010, 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_OOPS_KLASSVTABLE_HPP 26#define SHARE_VM_OOPS_KLASSVTABLE_HPP 27 28#include "memory/allocation.hpp" 29#include "oops/oopsHierarchy.hpp" 30#include "runtime/handles.hpp" 31#include "utilities/growableArray.hpp" 32 33// A klassVtable abstracts the variable-length vtable that is embedded in instanceKlass 34// and arrayKlass. klassVtable objects are used just as convenient transient accessors to the vtable, 35// not to actually hold the vtable data. 36// Note: the klassVtable should not be accessed before the class has been verified 37// (until that point, the vtable is uninitialized). 38 39// Currently a klassVtable contains a direct reference to the vtable data, and is therefore 40// not preserved across GCs. 41 42class vtableEntry; 43 44class klassVtable : public ResourceObj { 45 KlassHandle _klass; // my klass 46 int _tableOffset; // offset of start of vtable data within klass 47 int _length; // length of vtable (number of entries) 48#ifndef PRODUCT 49 int _verify_count; // to make verify faster 50#endif 51 52 // Ordering important, so greater_than (>) can be used as an merge operator. 53 enum AccessType { 54 acc_private = 0, 55 acc_package_private = 1, 56 acc_publicprotected = 2 57 }; 58 59 public: 60 klassVtable(KlassHandle h_klass, void* base, int length) : _klass(h_klass) { 61 _tableOffset = (address)base - (address)h_klass(); _length = length; 62 } 63 64 // accessors 65 vtableEntry* table() const { return (vtableEntry*)(address(_klass()) + _tableOffset); } 66 KlassHandle klass() const { return _klass; } 67 int length() const { return _length; } 68 inline methodOop method_at(int i) const; 69 inline methodOop unchecked_method_at(int i) const; 70 inline oop* adr_method_at(int i) const; 71 72 // searching; all methods return -1 if not found 73 int index_of(methodOop m) const { return index_of(m, _length); } 74 int index_of_miranda(Symbol* name, Symbol* signature); 75 76 void initialize_vtable(bool checkconstraints, TRAPS); // initialize vtable of a new klass 77 78 // conputes vtable length (in words) and the number of miranda methods 79 static void compute_vtable_size_and_num_mirandas(int &vtable_length, int &num_miranda_methods, 80 klassOop super, objArrayOop methods, 81 AccessFlags class_flags, Handle classloader, 82 Symbol* classname, objArrayOop local_interfaces, 83 TRAPS); 84 85 // RedefineClasses() API support: 86 // If any entry of this vtable points to any of old_methods, 87 // replace it with the corresponding new_method. 88 // trace_name_printed is set to true if the current call has 89 // printed the klass name so that other routines in the adjust_* 90 // group don't print the klass name. 91 void adjust_method_entries(methodOop* old_methods, methodOop* new_methods, 92 int methods_length, bool * trace_name_printed); 93 94 // Garbage collection 95 void oop_follow_contents(); 96 void oop_adjust_pointers(); 97 98#ifndef SERIALGC 99 // Parallel Old 100 void oop_follow_contents(ParCompactionManager* cm); 101 void oop_update_pointers(ParCompactionManager* cm); 102 void oop_update_pointers(ParCompactionManager* cm, 103 HeapWord* beg_addr, HeapWord* end_addr); 104#endif // SERIALGC 105 106 // Iterators 107 void oop_oop_iterate(OopClosure* blk); 108 void oop_oop_iterate_m(OopClosure* blk, MemRegion mr); 109 110 // Debugging code 111 void print() PRODUCT_RETURN; 112 void verify(outputStream* st, bool force = false); 113 static void print_statistics() PRODUCT_RETURN; 114 115#ifndef PRODUCT 116 bool check_no_old_entries(); 117 void dump_vtable(); 118#endif 119 120 protected: 121 friend class vtableEntry; 122 private: 123 enum { VTABLE_TRANSITIVE_OVERRIDE_VERSION = 51 } ; 124 void copy_vtable_to(vtableEntry* start); 125 int initialize_from_super(KlassHandle super); 126 int index_of(methodOop m, int len) const; // same as index_of, but search only up to len 127 void put_method_at(methodOop m, int index); 128 static bool needs_new_vtable_entry(methodHandle m, klassOop super, Handle classloader, Symbol* classname, AccessFlags access_flags, TRAPS); 129 130 bool update_inherited_vtable(instanceKlass* klass, methodHandle target_method, int super_vtable_len, bool checkconstraints, TRAPS); 131 instanceKlass* find_transitive_override(instanceKlass* initialsuper, methodHandle target_method, int vtable_index, 132 Handle target_loader, Symbol* target_classname, Thread* THREAD); 133 134 // support for miranda methods 135 bool is_miranda_entry_at(int i); 136 void fill_in_mirandas(int& initialized); 137 static bool is_miranda(methodOop m, objArrayOop class_methods, klassOop super); 138 static void add_new_mirandas_to_list(GrowableArray<methodOop>* list_of_current_mirandas, objArrayOop current_interface_methods, objArrayOop class_methods, klassOop super); 139 static void get_mirandas(GrowableArray<methodOop>* mirandas, klassOop super, objArrayOop class_methods, objArrayOop local_interfaces); 140 static int get_num_mirandas(klassOop super, objArrayOop class_methods, objArrayOop local_interfaces); 141 142 143 void verify_against(outputStream* st, klassVtable* vt, int index); 144 inline instanceKlass* ik() const; 145}; 146 147 148// private helper class for klassVtable 149// description of entry points: 150// destination is interpreted: 151// from_compiled_code_entry_point -> c2iadapter 152// from_interpreter_entry_point -> interpreter entry point 153// destination is compiled: 154// from_compiled_code_entry_point -> nmethod entry point 155// from_interpreter_entry_point -> i2cadapter 156class vtableEntry VALUE_OBJ_CLASS_SPEC { 157 public: 158 // size in words 159 static int size() { 160 return sizeof(vtableEntry) / sizeof(HeapWord); 161 } 162 static int method_offset_in_bytes() { return offset_of(vtableEntry, _method); } 163 methodOop method() const { return _method; } 164 165 private: 166 methodOop _method; 167 void set(methodOop method) { assert(method != NULL, "use clear"); _method = method; } 168 void clear() { _method = NULL; } 169 void print() PRODUCT_RETURN; 170 void verify(klassVtable* vt, outputStream* st); 171 172 friend class klassVtable; 173}; 174 175 176inline methodOop klassVtable::method_at(int i) const { 177 assert(i >= 0 && i < _length, "index out of bounds"); 178 assert(table()[i].method() != NULL, "should not be null"); 179 assert(oop(table()[i].method())->is_method(), "should be method"); 180 return table()[i].method(); 181} 182 183inline methodOop klassVtable::unchecked_method_at(int i) const { 184 assert(i >= 0 && i < _length, "index out of bounds"); 185 return table()[i].method(); 186} 187 188inline oop* klassVtable::adr_method_at(int i) const { 189 // Allow one past the last entry to be referenced; useful for loop bounds. 190 assert(i >= 0 && i <= _length, "index out of bounds"); 191 return (oop*)(address(table() + i) + vtableEntry::method_offset_in_bytes()); 192} 193 194// -------------------------------------------------------------------------------- 195class klassItable; 196class itableMethodEntry; 197 198class itableOffsetEntry VALUE_OBJ_CLASS_SPEC { 199 private: 200 klassOop _interface; 201 int _offset; 202 public: 203 klassOop interface_klass() const { return _interface; } 204 int offset() const { return _offset; } 205 206 static itableMethodEntry* method_entry(klassOop k, int offset) { return (itableMethodEntry*)(((address)k) + offset); } 207 itableMethodEntry* first_method_entry(klassOop k) { return method_entry(k, _offset); } 208 209 void initialize(klassOop interf, int offset) { _interface = interf; _offset = offset; } 210 211 // Static size and offset accessors 212 static int size() { return sizeof(itableOffsetEntry) / HeapWordSize; } // size in words 213 static int interface_offset_in_bytes() { return offset_of(itableOffsetEntry, _interface); } 214 static int offset_offset_in_bytes() { return offset_of(itableOffsetEntry, _offset); } 215 216 friend class klassItable; 217}; 218 219 220class itableMethodEntry VALUE_OBJ_CLASS_SPEC { 221 private: 222 methodOop _method; 223 224 public: 225 methodOop method() const { return _method; } 226 227 void clear() { _method = NULL; } 228 229 void initialize(methodOop method); 230 231 // Static size and offset accessors 232 static int size() { return sizeof(itableMethodEntry) / HeapWordSize; } // size in words 233 static int method_offset_in_bytes() { return offset_of(itableMethodEntry, _method); } 234 235 friend class klassItable; 236}; 237 238// 239// Format of an itable 240// 241// ---- offset table --- 242// klassOop of interface 1 \ 243// offset to vtable from start of oop / offset table entry 244// ... 245// klassOop of interface n \ 246// offset to vtable from start of oop / offset table entry 247// --- vtable for interface 1 --- 248// methodOop \ 249// compiler entry point / method table entry 250// ... 251// methodOop \ 252// compiler entry point / method table entry 253// -- vtable for interface 2 --- 254// ... 255// 256class klassItable : public ResourceObj { 257 private: 258 instanceKlassHandle _klass; // my klass 259 int _table_offset; // offset of start of itable data within klass (in words) 260 int _size_offset_table; // size of offset table (in itableOffset entries) 261 int _size_method_table; // size of methodtable (in itableMethodEntry entries) 262 263 void initialize_itable_for_interface(int method_table_offset, KlassHandle interf_h, bool checkconstraints, TRAPS); 264 public: 265 klassItable(instanceKlassHandle klass); 266 267 itableOffsetEntry* offset_entry(int i) { assert(0 <= i && i <= _size_offset_table, "index out of bounds"); 268 return &((itableOffsetEntry*)vtable_start())[i]; } 269 270 itableMethodEntry* method_entry(int i) { assert(0 <= i && i <= _size_method_table, "index out of bounds"); 271 return &((itableMethodEntry*)method_start())[i]; } 272 273 int size_offset_table() { return _size_offset_table; } 274 275 // Initialization 276 void initialize_itable(bool checkconstraints, TRAPS); 277 278 // Updates 279 void initialize_with_method(methodOop m); 280 281 // RedefineClasses() API support: 282 // if any entry of this itable points to any of old_methods, 283 // replace it with the corresponding new_method. 284 // trace_name_printed is set to true if the current call has 285 // printed the klass name so that other routines in the adjust_* 286 // group don't print the klass name. 287 void adjust_method_entries(methodOop* old_methods, methodOop* new_methods, 288 int methods_length, bool * trace_name_printed); 289 290 // Garbage collection 291 void oop_follow_contents(); 292 void oop_adjust_pointers(); 293 294#ifndef SERIALGC 295 // Parallel Old 296 void oop_follow_contents(ParCompactionManager* cm); 297 void oop_update_pointers(ParCompactionManager* cm); 298 void oop_update_pointers(ParCompactionManager* cm, 299 HeapWord* beg_addr, HeapWord* end_addr); 300#endif // SERIALGC 301 302 // Iterators 303 void oop_oop_iterate(OopClosure* blk); 304 void oop_oop_iterate_m(OopClosure* blk, MemRegion mr); 305 306 // Setup of itable 307 static int compute_itable_size(objArrayHandle transitive_interfaces); 308 static void setup_itable_offset_table(instanceKlassHandle klass); 309 310 // Resolving of method to index 311 static int compute_itable_index(methodOop m); 312 // ...and back again: 313 static methodOop method_for_itable_index(klassOop klass, int itable_index); 314 315 // Debugging/Statistics 316 static void print_statistics() PRODUCT_RETURN; 317 private: 318 intptr_t* vtable_start() const { return ((intptr_t*)_klass()) + _table_offset; } 319 intptr_t* method_start() const { return vtable_start() + _size_offset_table * itableOffsetEntry::size(); } 320 321 // Helper methods 322 static int calc_itable_size(int num_interfaces, int num_methods) { return (num_interfaces * itableOffsetEntry::size()) + (num_methods * itableMethodEntry::size()); } 323 324 // Statistics 325 NOT_PRODUCT(static int _total_classes;) // Total no. of classes with itables 326 NOT_PRODUCT(static long _total_size;) // Total no. of bytes used for itables 327 328 static void update_stats(int size) PRODUCT_RETURN NOT_PRODUCT({ _total_classes++; _total_size += size; }) 329}; 330 331#endif // SHARE_VM_OOPS_KLASSVTABLE_HPP 332