1 /* 2 * Copyright (c) 1998, 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_CPCACHEOOP_HPP 26 #define SHARE_VM_OOPS_CPCACHEOOP_HPP 27 28 #include "interpreter/bytecodes.hpp" 29 #include "memory/allocation.hpp" 30 #include "oops/arrayOop.hpp" 31 #include "utilities/array.hpp" 32 33 // A ConstantPoolCacheEntry describes an individual entry of the constant 34 // pool cache. There's 2 principal kinds of entries: field entries for in- 35 // stance & static field access, and method entries for invokes. Some of 36 // the entry layout is shared and looks as follows: 37 // 38 // bit number |31 0| 39 // bit length |-8--|-8--|---16----| 40 // -------------------------------- 41 // _indices [ b2 | b1 | index ] 42 // _f1 [ entry specific ] 43 // _f2 [ entry specific ] 44 // _flags [t|f|vf|v|m|h|unused|field_index] (for field entries) 45 // bit length |4|1|1 |1|1|0|---7--|----16-----] 46 // _flags [t|f|vf|v|m|h|unused|eidx|psze] (for method entries) 47 // bit length |4|1|1 |1|1|1|---7--|-8--|-8--] 48 49 // -------------------------------- 50 // 51 // with: 52 // index = original constant pool index 53 // b1 = bytecode 1 54 // b2 = bytecode 2 55 // psze = parameters size (method entries only) 56 // eidx = interpreter entry index (method entries only) 57 // field_index = index into field information in holder instanceKlass 58 // The index max is 0xffff (max number of fields in constant pool) 59 // and is multiplied by (instanceKlass::next_offset) when accessing. 60 // t = TosState (see below) 61 // f = field is marked final (see below) 62 // vf = virtual, final (method entries only : is_vfinal()) 63 // v = field is volatile (see below) 64 // m = invokeinterface used for method in class Object (see below) 65 // h = RedefineClasses/Hotswap bit (see below) 66 // 67 // The flags after TosState have the following interpretation: 68 // bit 27: f flag true if field is marked final 69 // bit 26: vf flag true if virtual final method 70 // bit 25: v flag true if field is volatile (only for fields) 71 // bit 24: m flag true if invokeinterface used for method in class Object 72 // bit 23: 0 for fields, 1 for methods 73 // 74 // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 8 with the 75 // following mapping to the TosState states: 76 // 77 // btos: 0 78 // ctos: 1 79 // stos: 2 80 // itos: 3 81 // ltos: 4 82 // ftos: 5 83 // dtos: 6 84 // atos: 7 85 // vtos: 8 86 // 87 // Entry specific: field entries: 88 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index 89 // _f1 = field holder 90 // _f2 = field offset in words 91 // _flags = field type information, original field index in field holder 92 // (field_index section) 93 // 94 // Entry specific: method entries: 95 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section), 96 // original constant pool index 97 // _f1 = method for all but virtual calls, unused by virtual calls 98 // (note: for interface calls, which are essentially virtual, 99 // contains klassOop for the corresponding interface. 100 // for invokedynamic, f1 contains the CallSite object for the invocation 101 // _f2 = method/vtable index for virtual calls only, unused by all other 102 // calls. The vf flag indicates this is a method pointer not an 103 // index. 104 // _flags = field type info (f section), 105 // virtual final entry (vf), 106 // interpreter entry index (eidx section), 107 // parameter size (psze section) 108 // 109 // Note: invokevirtual & invokespecial bytecodes can share the same constant 110 // pool entry and thus the same constant pool cache entry. All invoke 111 // bytecodes but invokevirtual use only _f1 and the corresponding b1 112 // bytecode, while invokevirtual uses only _f2 and the corresponding 113 // b2 bytecode. The value of _flags is shared for both types of entries. 114 // 115 // The fields are volatile so that they are stored in the order written in the 116 // source code. The _indices field with the bytecode must be written last. 117 118 class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC { 119 friend class VMStructs; 120 friend class constantPoolCacheKlass; 121 friend class constantPoolOopDesc; //resolve_constant_at_impl => set_f1 122 123 private: 124 volatile intx _indices; // constant pool index & rewrite bytecodes 125 volatile oop _f1; // entry specific oop field 126 volatile intx _f2; // entry specific int/oop field 127 volatile intx _flags; // flags 128 129 130 #ifdef ASSERT 131 bool same_methodOop(oop cur_f1, oop f1); 132 #endif 133 134 void set_bytecode_1(Bytecodes::Code code); 135 void set_bytecode_2(Bytecodes::Code code); 136 void set_f1(oop f1) { 137 oop existing_f1 = _f1; // read once 138 assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change"); 139 oop_store(&_f1, f1); 140 } 141 void set_f2(intx f2) { assert(_f2 == 0 || _f2 == f2, "illegal field change"); _f2 = f2; } 142 int as_flags(TosState state, bool is_final, bool is_vfinal, bool is_volatile, 143 bool is_method_interface, bool is_method); 144 void set_flags(intx flags) { _flags = flags; } 145 146 public: 147 // specific bit values in flag field 148 // Note: the interpreter knows this layout! 149 enum FlagBitValues { 150 hotSwapBit = 23, 151 methodInterface = 24, 152 volatileField = 25, 153 vfinalMethod = 26, 154 finalField = 27 155 }; 156 157 enum { field_index_mask = 0xFFFF }; 158 159 // start of type bits in flags 160 // Note: the interpreter knows this layout! 161 enum FlagValues { 162 tosBits = 28 163 }; 164 165 // Initialization 166 void initialize_entry(int original_index); // initialize primary entry 167 void initialize_secondary_entry(int main_index); // initialize secondary entry 168 169 void set_field( // sets entry to resolved field state 170 Bytecodes::Code get_code, // the bytecode used for reading the field 171 Bytecodes::Code put_code, // the bytecode used for writing the field 172 KlassHandle field_holder, // the object/klass holding the field 173 int orig_field_index, // the original field index in the field holder 174 int field_offset, // the field offset in words in the field holder 175 TosState field_type, // the (machine) field type 176 bool is_final, // the field is final 177 bool is_volatile // the field is volatile 178 ); 179 180 void set_method( // sets entry to resolved method entry 181 Bytecodes::Code invoke_code, // the bytecode used for invoking the method 182 methodHandle method, // the method/prototype if any (NULL, otherwise) 183 int vtable_index // the vtable index if any, else negative 184 ); 185 186 void set_interface_call( 187 methodHandle method, // Resolved method 188 int index // Method index into interface 189 ); 190 191 void set_dynamic_call( 192 Handle call_site, // Resolved java.dyn.CallSite (f1) 193 methodHandle signature_invoker // determines signature information 194 ); 195 196 // For JVM_CONSTANT_InvokeDynamic cache entries: 197 void initialize_bootstrap_method_index_in_cache(int bsm_cache_index); 198 int bootstrap_method_index_in_cache(); 199 200 void set_parameter_size(int value) { 201 assert(parameter_size() == 0 || parameter_size() == value, 202 "size must not change"); 203 // Setting the parameter size by itself is only safe if the 204 // current value of _flags is 0, otherwise another thread may have 205 // updated it and we don't want to overwrite that value. Don't 206 // bother trying to update it once it's nonzero but always make 207 // sure that the final parameter size agrees with what was passed. 208 if (_flags == 0) { 209 Atomic::cmpxchg_ptr((value & 0xFF), &_flags, 0); 210 } 211 guarantee(parameter_size() == value, "size must not change"); 212 } 213 214 // Which bytecode number (1 or 2) in the index field is valid for this bytecode? 215 // Returns -1 if neither is valid. 216 static int bytecode_number(Bytecodes::Code code) { 217 switch (code) { 218 case Bytecodes::_getstatic : // fall through 219 case Bytecodes::_getfield : // fall through 220 case Bytecodes::_invokespecial : // fall through 221 case Bytecodes::_invokestatic : // fall through 222 case Bytecodes::_invokedynamic : // fall through 223 case Bytecodes::_invokeinterface : return 1; 224 case Bytecodes::_putstatic : // fall through 225 case Bytecodes::_putfield : // fall through 226 case Bytecodes::_invokevirtual : return 2; 227 default : break; 228 } 229 return -1; 230 } 231 232 // Has this bytecode been resolved? Only valid for invokes and get/put field/static. 233 bool is_resolved(Bytecodes::Code code) const { 234 switch (bytecode_number(code)) { 235 case 1: return (bytecode_1() == code); 236 case 2: return (bytecode_2() == code); 237 } 238 return false; // default: not resolved 239 } 240 241 // Accessors 242 bool is_secondary_entry() const { return (_indices & 0xFFFF) == 0; } 243 int constant_pool_index() const { assert((_indices & 0xFFFF) != 0, "must be main entry"); 244 return (_indices & 0xFFFF); } 245 int main_entry_index() const { assert((_indices & 0xFFFF) == 0, "must be secondary entry"); 246 return ((uintx)_indices >> 16); } 247 Bytecodes::Code bytecode_1() const { return Bytecodes::cast((_indices >> 16) & 0xFF); } 248 Bytecodes::Code bytecode_2() const { return Bytecodes::cast((_indices >> 24) & 0xFF); } 249 volatile oop f1() const { return _f1; } 250 bool is_f1_null() const { return (oop)_f1 == NULL; } // classifies a CPC entry as unbound 251 intx f2() const { return _f2; } 252 int field_index() const; 253 int parameter_size() const { return _flags & 0xFF; } 254 bool is_vfinal() const { return ((_flags & (1 << vfinalMethod)) == (1 << vfinalMethod)); } 255 bool is_volatile() const { return ((_flags & (1 << volatileField)) == (1 << volatileField)); } 256 bool is_methodInterface() const { return ((_flags & (1 << methodInterface)) == (1 << methodInterface)); } 257 bool is_byte() const { return (((uintx) _flags >> tosBits) == btos); } 258 bool is_char() const { return (((uintx) _flags >> tosBits) == ctos); } 259 bool is_short() const { return (((uintx) _flags >> tosBits) == stos); } 260 bool is_int() const { return (((uintx) _flags >> tosBits) == itos); } 261 bool is_long() const { return (((uintx) _flags >> tosBits) == ltos); } 262 bool is_float() const { return (((uintx) _flags >> tosBits) == ftos); } 263 bool is_double() const { return (((uintx) _flags >> tosBits) == dtos); } 264 bool is_object() const { return (((uintx) _flags >> tosBits) == atos); } 265 TosState flag_state() const { assert( ( (_flags >> tosBits) & 0x0F ) < number_of_states, "Invalid state in as_flags"); 266 return (TosState)((_flags >> tosBits) & 0x0F); } 267 268 // Code generation support 269 static WordSize size() { return in_WordSize(sizeof(ConstantPoolCacheEntry) / HeapWordSize); } 270 static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); } 271 static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); } 272 static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); } 273 static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); } 274 static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); } 275 276 // GC Support 277 void oops_do(void f(oop*)); 278 void oop_iterate(OopClosure* blk); 279 void oop_iterate_m(OopClosure* blk, MemRegion mr); 280 void follow_contents(); 281 void adjust_pointers(); 282 283 #ifndef SERIALGC 284 // Parallel Old 285 void follow_contents(ParCompactionManager* cm); 286 #endif // SERIALGC 287 288 void update_pointers(); 289 void update_pointers(HeapWord* beg_addr, HeapWord* end_addr); 290 291 // RedefineClasses() API support: 292 // If this constantPoolCacheEntry refers to old_method then update it 293 // to refer to new_method. 294 // trace_name_printed is set to true if the current call has 295 // printed the klass name so that other routines in the adjust_* 296 // group don't print the klass name. 297 bool adjust_method_entry(methodOop old_method, methodOop new_method, 298 bool * trace_name_printed); 299 bool is_interesting_method_entry(klassOop k); 300 bool is_field_entry() const { return (_flags & (1 << hotSwapBit)) == 0; } 301 bool is_method_entry() const { return (_flags & (1 << hotSwapBit)) != 0; } 302 303 // Debugging & Printing 304 void print (outputStream* st, int index) const; 305 void verify(outputStream* st) const; 306 307 static void verify_tosBits() { 308 assert(tosBits == 28, "interpreter now assumes tosBits is 28"); 309 } 310 }; 311 312 313 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache 314 // holds interpreter runtime information for all field access and invoke bytecodes. The cache 315 // is created and initialized before a class is actively used (i.e., initialized), the indivi- 316 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*). 317 318 class constantPoolCacheOopDesc: public oopDesc { 319 friend class VMStructs; 320 private: 321 int _length; 322 constantPoolOop _constant_pool; // the corresponding constant pool 323 // If true, safe for concurrent GC processing, 324 // Set unconditionally in constantPoolCacheKlass::allocate() 325 volatile bool _is_conc_safe; 326 327 // Sizing 328 debug_only(friend class ClassVerifier;) 329 int length() const { return _length; } 330 void set_length(int length) { _length = length; } 331 332 static int header_size() { return sizeof(constantPoolCacheOopDesc) / HeapWordSize; } 333 static int object_size(int length) { return align_object_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); } 334 int object_size() { return object_size(length()); } 335 336 // Helpers 337 constantPoolOop* constant_pool_addr() { return &_constant_pool; } 338 ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); } 339 340 friend class constantPoolCacheKlass; 341 friend class ConstantPoolCacheEntry; 342 343 public: 344 // Initialization 345 void initialize(intArray& inverse_index_map); 346 347 // Secondary indexes. 348 // They must look completely different from normal indexes. 349 // The main reason is that byte swapping is sometimes done on normal indexes. 350 // Also, some of the CP accessors do different things for secondary indexes. 351 // Finally, it is helpful for debugging to tell the two apart. 352 static bool is_secondary_index(int i) { return (i < 0); } 353 static int decode_secondary_index(int i) { assert(is_secondary_index(i), ""); return ~i; } 354 static int encode_secondary_index(int i) { assert(!is_secondary_index(i), ""); return ~i; } 355 356 // Accessors 357 void set_constant_pool(constantPoolOop pool) { oop_store_without_check((oop*)&_constant_pool, (oop)pool); } 358 constantPoolOop constant_pool() const { return _constant_pool; } 359 // Fetches the entry at the given index. 360 // The entry may be either primary or secondary. 361 // In either case the index must not be encoded or byte-swapped in any way. 362 ConstantPoolCacheEntry* entry_at(int i) const { 363 assert(0 <= i && i < length(), "index out of bounds"); 364 return base() + i; 365 } 366 // Fetches the secondary entry referred to by index. 367 // The index may be a secondary index, and must not be byte-swapped. 368 ConstantPoolCacheEntry* secondary_entry_at(int i) const { 369 int raw_index = i; 370 if (is_secondary_index(i)) { // correct these on the fly 371 raw_index = decode_secondary_index(i); 372 } 373 assert(entry_at(raw_index)->is_secondary_entry(), "not a secondary entry"); 374 return entry_at(raw_index); 375 } 376 // Given a primary or secondary index, fetch the corresponding primary entry. 377 // Indirect through the secondary entry, if the index is encoded as a secondary index. 378 // The index must not be byte-swapped. 379 ConstantPoolCacheEntry* main_entry_at(int i) const { 380 int primary_index = i; 381 if (is_secondary_index(i)) { 382 // run through an extra level of indirection: 383 int raw_index = decode_secondary_index(i); 384 primary_index = entry_at(raw_index)->main_entry_index(); 385 } 386 assert(!entry_at(primary_index)->is_secondary_entry(), "only one level of indirection"); 387 return entry_at(primary_index); 388 } 389 390 // GC support 391 // If the _length field has not been set, the size of the 392 // constantPoolCache cannot be correctly calculated. 393 bool is_conc_safe() { return _is_conc_safe; } 394 void set_is_conc_safe(bool v) { _is_conc_safe = v; } 395 396 // Code generation 397 static ByteSize base_offset() { return in_ByteSize(sizeof(constantPoolCacheOopDesc)); } 398 static ByteSize entry_offset(int raw_index) { 399 int index = raw_index; 400 if (is_secondary_index(raw_index)) 401 index = decode_secondary_index(raw_index); 402 return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index); 403 } 404 405 // RedefineClasses() API support: 406 // If any entry of this constantPoolCache points to any of 407 // old_methods, replace it with the corresponding new_method. 408 // trace_name_printed is set to true if the current call has 409 // printed the klass name so that other routines in the adjust_* 410 // group don't print the klass name. 411 void adjust_method_entries(methodOop* old_methods, methodOop* new_methods, 412 int methods_length, bool * trace_name_printed); 413 }; 414 415 #endif // SHARE_VM_OOPS_CPCACHEOOP_HPP