constantPool.hpp (original) (raw)

1 /* 2 * Copyright (c) 1997, 2015, 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_CONSTANTPOOLOOP_HPP 26 #define SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP 27 28 #include "oops/arrayOop.hpp" 29 #include "oops/cpCache.hpp" 30 #include "oops/objArrayOop.hpp" 31 #include "oops/symbol.hpp" 32 #include "oops/typeArrayOop.hpp" 33 #include "runtime/handles.hpp" 34 #include "utilities/bytes.hpp" 35 #include "utilities/constantTag.hpp" 36 37 // A ConstantPool is an array containing class constants as described in the 38 // class file. 39 // 40 // Most of the constant pool entries are written during class parsing, which 41 // is safe. For klass types, the constant pool entry is 42 // modified when the entry is resolved. If a klass constant pool 43 // entry is read without a lock, only the resolved state guarantees that 44 // the entry in the constant pool is a klass object and not a Symbol. 45 46 class SymbolHashMap; 47 48 class CPSlot VALUE_OBJ_CLASS_SPEC { 49 intptr_t _ptr; 50 public: 51 enum TagBits { _resolved_value = 0, _symbol_bit = 1, _pseudo_bit = 2, _symbol_mask = 3 }; 52 53 CPSlot(intptr_t ptr): _ptr(ptr) {} 54 CPSlot(Klass* ptr): _ptr((intptr_t)ptr) {} 55 CPSlot(Symbol* ptr): _ptr((intptr_t)ptr | _symbol_bit) {} 56 CPSlot(Symbol* ptr, int tag_bits): _ptr((intptr_t)ptr | tag_bits) {} 57 58 intptr_t value() { return _ptr; } 59 bool is_resolved() { return (_ptr & _symbol_bit ) == _resolved_value; } 60 bool is_unresolved() { return (_ptr & _symbol_bit ) != _resolved_value; } 61 bool is_pseudo_string() { return (_ptr & _symbol_mask) == _symbol_bit + _pseudo_bit; } 62 63 Symbol* get_symbol() { 64 assert(is_unresolved(), "bad call"); 65 return (Symbol*)(_ptr & ~_symbol_mask); 66 } 67 Klass* get_klass() { 68 assert(is_resolved(), "bad call"); 69 return (Klass*)_ptr; 70 } 71 }; 72 73 class KlassSizeStats; 74 75 class ConstantPool : public Metadata { 76 friend class VMStructs; 77 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast 78 friend class Universe; // For null constructor 79 private: 80 Array* _tags; // the tag array describing the constant pool's contents 81 ConstantPoolCache* _cache; // the cache holding interpreter runtime information 82 InstanceKlass* _pool_holder; // the corresponding class 83 Array* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty 84 85 // Array of resolved objects from the constant pool and map from resolved 86 // object index to original constant pool index 87 jobject _resolved_references; 88 Array* _reference_map; 89 90 enum { 91 _has_preresolution = 1, // Flags 92 _on_stack = 2 93 }; 94 95 int _flags; // old fashioned bit twiddling 96 int _length; // number of elements in the array 97 98 union { 99 // set for CDS to restore resolved references 100 int _resolved_reference_length; 101 // keeps version number for redefined classes (used in backtrace) 102 int _version; 103 } _saved; 104 105 void set_tags(Array* tags) { _tags = tags; } 106 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); } 107 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); } 108 109 u1* tag_addr_at(int which) const { return tags()->adr_at(which); } 110 111 void set_operands(Array* operands) { _operands = operands; } 112 113 int flags() const { return _flags; } 114 void set_flags(int f) { _flags = f; } 115 116 private: 117 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); } 118 119 CPSlot slot_at(int which) { 120 assert(is_within_bounds(which), "index out of bounds"); 121 // Uses volatile because the klass slot changes without a lock. 122 volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which)); 123 assert(adr != 0 || which == 0, "cp entry for klass should not be zero"); 124 return CPSlot(adr); 125 } 126 127 void slot_at_put(int which, CPSlot s) const { 128 assert(is_within_bounds(which), "index out of bounds"); 129 assert(s.value() != 0, "Caught something"); 130 (intptr_t)&base()[which] = s.value(); 131 } 132 intptr_t* obj_at_addr_raw(int which) const { 133 assert(is_within_bounds(which), "index out of bounds"); 134 return (intptr_t*) &base()[which]; 135 } 136 137 jint* int_at_addr(int which) const { 138 assert(is_within_bounds(which), "index out of bounds"); 139 return (jint*) &base()[which]; 140 } 141 142 jlong* long_at_addr(int which) const { 143 assert(is_within_bounds(which), "index out of bounds"); 144 return (jlong*) &base()[which]; 145 } 146 147 jfloat* float_at_addr(int which) const { 148 assert(is_within_bounds(which), "index out of bounds"); 149 return (jfloat*) &base()[which]; 150 } 151 152 jdouble* double_at_addr(int which) const { 153 assert(is_within_bounds(which), "index out of bounds"); 154 return (jdouble*) &base()[which]; 155 } 156 157 ConstantPool(Array* tags); 158 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); } 159 public: 160 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS); 161 162 bool is_constantPool() const volatile { return true; } 163 164 Array* tags() const { return _tags; } 165 Array* operands() const { return _operands; } 166 167 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; } 168 void set_has_preresolution() { _flags |= _has_preresolution; } 169 170 // Redefine classes support. If a method refering to this constant pool 171 // is on the executing stack, or as a handle in vm code, this constant pool 172 // can't be removed from the set of previous versions saved in the instance 173 // class. 174 bool on_stack() const { return (_flags &_on_stack) != 0; } 175 void set_on_stack(const bool value); 176 177 // Klass holding pool 178 InstanceKlass* pool_holder() const { return _pool_holder; } 179 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; } 180 InstanceKlass** pool_holder_addr() { return &_pool_holder; } 181 182 // Interpreter runtime support 183 ConstantPoolCache* cache() const { return _cache; } 184 void set_cache(ConstantPoolCache* cache){ _cache = cache; } 185 186 // Create object cache in the constant pool 187 void initialize_resolved_references(ClassLoaderData* loader_data, 188 intStack reference_map, 189 int constant_pool_map_length, 190 TRAPS); 191 192 // resolved strings, methodHandles and callsite objects from the constant pool 193 objArrayOop resolved_references() const; 194 // mapping resolved object array indexes to cp indexes and back. 195 int object_to_cp_index(int index) { return _reference_map->at(index); } 196 int cp_to_object_index(int index); 197 198 // Invokedynamic indexes. 199 // They must look completely different from normal indexes. 200 // The main reason is that byte swapping is sometimes done on normal indexes. 201 // Finally, it is helpful for debugging to tell the two apart. 202 static bool is_invokedynamic_index(int i) { return (i < 0); } 203 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; } 204 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; } 205 206 207 // The invokedynamic points at a CP cache entry. This entry points back 208 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry 209 // in the resolved_references array (which provides the appendix argument). 210 int invokedynamic_cp_cache_index(int index) const { 211 assert (is_invokedynamic_index(index), "should be a invokedynamic index"); 212 int cache_index = decode_invokedynamic_index(index); 213 return cache_index; 214 } 215 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const { 216 // decode index that invokedynamic points to. 217 int cp_cache_index = invokedynamic_cp_cache_index(index); 218 return cache()->entry_at(cp_cache_index); 219 } 220 221 // Assembly code support 222 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); } 223 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); } 224 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); } 225 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPool, _resolved_references); } 226 227 // Storing constants 228 229 void klass_at_put(int which, Klass* k) { 230 assert(k != NULL, "resolved class shouldn't be null"); 231 assert(is_within_bounds(which), "index out of bounds"); 232 OrderAccess::release_store_ptr((Klass* volatile )obj_at_addr_raw(which), k); 233 // The interpreter assumes when the tag is stored, the klass is resolved 234 // and the Klass is a klass rather than a Symbol*, so we need 235 // hardware store ordering here. 236 release_tag_at_put(which, JVM_CONSTANT_Class); 237 } 238 239 // For temporary use while constructing constant pool 240 void klass_index_at_put(int which, int name_index) { 241 tag_at_put(which, JVM_CONSTANT_ClassIndex); 242 int_at_addr(which) = name_index; 243 } 244 245 // Temporary until actual use 246 void unresolved_klass_at_put(int which, Symbol s) { 247 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass); 248 slot_at_put(which, s); 249 } 250 251 void method_handle_index_at_put(int which, int ref_kind, int ref_index) { 252 tag_at_put(which, JVM_CONSTANT_MethodHandle); 253 int_at_addr(which) = ((jint) ref_index<<16) | ref_kind; 254 } 255 256 void method_type_index_at_put(int which, int ref_index) { 257 tag_at_put(which, JVM_CONSTANT_MethodType); 258 *int_at_addr(which) = ref_index; 259 } 260 261 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) { 262 tag_at_put(which, JVM_CONSTANT_InvokeDynamic); 263 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index; 264 } 265 266 void unresolved_string_at_put(int which, Symbol* s) { 267 release_tag_at_put(which, JVM_CONSTANT_String); 268 slot_at_put(which, CPSlot(s, CPSlot::_symbol_bit)); 269 } 270 271 void int_at_put(int which, jint i) { 272 tag_at_put(which, JVM_CONSTANT_Integer); 273 *int_at_addr(which) = i; 274 } 275 276 void long_at_put(int which, jlong l) { 277 tag_at_put(which, JVM_CONSTANT_Long); 278 // *long_at_addr(which) = l; 279 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l)); 280 } 281 282 void float_at_put(int which, jfloat f) { 283 tag_at_put(which, JVM_CONSTANT_Float); 284 *float_at_addr(which) = f; 285 } 286 287 void double_at_put(int which, jdouble d) { 288 tag_at_put(which, JVM_CONSTANT_Double); 289 // *double_at_addr(which) = d; 290 // u8 temp = *(u8*) &d; 291 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d)); 292 } 293 294 Symbol** symbol_at_addr(int which) const { 295 assert(is_within_bounds(which), "index out of bounds"); 296 return (Symbol**) &base()[which]; 297 } 298 299 void symbol_at_put(int which, Symbol* s) { 300 assert(s->refcount() != 0, "should have nonzero refcount"); 301 tag_at_put(which, JVM_CONSTANT_Utf8); 302 symbol_at_addr(which) = s; 303 } 304 305 void string_at_put(int which, int obj_index, oop str) { 306 resolved_references()->obj_at_put(obj_index, str); 307 } 308 309 // For temporary use while constructing constant pool 310 void string_index_at_put(int which, int string_index) { 311 tag_at_put(which, JVM_CONSTANT_StringIndex); 312 int_at_addr(which) = string_index; 313 } 314 315 void field_at_put(int which, int class_index, int name_and_type_index) { 316 tag_at_put(which, JVM_CONSTANT_Fieldref); 317 int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; 318 } 319 320 void method_at_put(int which, int class_index, int name_and_type_index) { 321 tag_at_put(which, JVM_CONSTANT_Methodref); 322 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; 323 } 324 325 void interface_method_at_put(int which, int class_index, int name_and_type_index) { 326 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref); 327 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice 328 } 329 330 void name_and_type_at_put(int which, int name_index, int signature_index) { 331 tag_at_put(which, JVM_CONSTANT_NameAndType); 332 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice 333 } 334 335 // Tag query 336 337 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); } 338 339 // Fetching constants 340 341 Klass klass_at(int which, TRAPS) { 342 constantPoolHandle h_this(THREAD, this); 343 return klass_at_impl(h_this, which, true, THREAD); 344 } 345 346 // Version of klass_at that doesn't save the resolution error, called during deopt 347 Klass klass_at_ignore_error(int which, TRAPS) { 348 constantPoolHandle h_this(THREAD, this); 349 return klass_at_impl(h_this, which, false, THREAD); 350 } 351 352 Symbol klass_name_at(int which); // Returns the name, w/o resolving. 353 354 Klass resolved_klass_at(int which) const { // Used by Compiler 355 guarantee(tag_at(which).is_klass(), "Corrupted constant pool"); 356 // Must do an acquire here in case another thread resolved the klass 357 // behind our back, lest we later load stale values thru the oop. 358 return CPSlot((Klass*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_klass(); 359 } 360 361 // RedefineClasses() API support: 362 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); } 363 364 jint int_at(int which) { 365 assert(tag_at(which).is_int(), "Corrupted constant pool"); 366 return int_at_addr(which); 367 } 368 369 jlong long_at(int which) { 370 assert(tag_at(which).is_long(), "Corrupted constant pool"); 371 // return long_at_addr(which); 372 u8 tmp = Bytes::get_native_u8((address)&base()[which]); 373 return ((jlong)&tmp); 374 } 375 376 jfloat float_at(int which) { 377 assert(tag_at(which).is_float(), "Corrupted constant pool"); 378 return float_at_addr(which); 379 } 380 381 jdouble double_at(int which) { 382 assert(tag_at(which).is_double(), "Corrupted constant pool"); 383 u8 tmp = Bytes::get_native_u8((address)&base()[which]); 384 return ((jdouble)&tmp); 385 } 386 387 Symbol symbol_at(int which) { 388 assert(tag_at(which).is_utf8(), "Corrupted constant pool"); 389 return symbol_at_addr(which); 390 } 391 392 oop string_at(int which, int obj_index, TRAPS) { 393 constantPoolHandle h_this(THREAD, this); 394 return string_at_impl(h_this, which, obj_index, THREAD); 395 } 396 oop string_at(int which, TRAPS) { 397 int obj_index = cp_to_object_index(which); 398 return string_at(which, obj_index, THREAD); 399 } 400 401 // Version that can be used before string oop array is created. 402 oop uncached_string_at(int which, TRAPS); 403 404 // A "pseudo-string" is an non-string oop that has found its way into 405 // a String entry. 406 // This can happen if the user patches a live 407 // object into a CONSTANT_String entry of an anonymous class. 408 // Method oops internally created for method handles may also 409 // use pseudo-strings to link themselves to related metaobjects. 410 411 bool is_pseudo_string_at(int which) { 412 assert(tag_at(which).is_string(), "Corrupted constant pool"); 413 return slot_at(which).is_pseudo_string(); 414 } 415 416 oop pseudo_string_at(int which, int obj_index) { 417 assert(is_pseudo_string_at(which), "must be a pseudo-string"); 418 oop s = resolved_references()->obj_at(obj_index); 419 return s; 420 } 421 422 oop pseudo_string_at(int which) { 423 assert(is_pseudo_string_at(which), "must be a pseudo-string"); 424 int obj_index = cp_to_object_index(which); 425 oop s = resolved_references()->obj_at(obj_index); 426 return s; 427 } 428 429 void pseudo_string_at_put(int which, int obj_index, oop x) { 430 assert(tag_at(which).is_string(), "Corrupted constant pool"); 431 Symbol sym = unresolved_string_at(which); 432 slot_at_put(which, CPSlot(sym, (CPSlot::_symbol_bit | CPSlot::_pseudo_bit))); 433 string_at_put(which, obj_index, x); // this works just fine 434 } 435 436 // only called when we are sure a string entry is already resolved (via an 437 // earlier string_at call. 438 oop resolved_string_at(int which) { 439 assert(tag_at(which).is_string(), "Corrupted constant pool"); 440 // Must do an acquire here in case another thread resolved the klass 441 // behind our back, lest we later load stale values thru the oop. 442 // we might want a volatile_obj_at in ObjArrayKlass. 443 int obj_index = cp_to_object_index(which); 444 return resolved_references()->obj_at(obj_index); 445 } 446 447 Symbol unresolved_string_at(int which) { 448 assert(tag_at(which).is_string(), "Corrupted constant pool"); 449 Symbol sym = slot_at(which).get_symbol(); 450 return sym; 451 } 452 453 // Returns an UTF8 for a CONSTANT_String entry at a given index. 454 // UTF8 char* representation was chosen to avoid conversion of 455 // java_lang_Strings at resolved entries into Symbols 456 // or vice versa. 457 char string_at_noresolve(int which); 458 459 jint name_and_type_at(int which) { 460 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool"); 461 return int_at_addr(which); 462 } 463 464 private: 465 int method_handle_ref_kind_at(int which, bool error_ok) { 466 assert(tag_at(which).is_method_handle() || 467 (error_ok && tag_at(which).is_method_handle_in_error()), "Corrupted constant pool"); 468 return extract_low_short_from_int(int_at_addr(which)); // mask out unwanted ref_index bits 469 } 470 int method_handle_index_at(int which, bool error_ok) { 471 assert(tag_at(which).is_method_handle() || 472 (error_ok && tag_at(which).is_method_handle_in_error()), "Corrupted constant pool"); 473 return extract_high_short_from_int(int_at_addr(which)); // shift out unwanted ref_kind bits 474 } 475 int method_type_index_at(int which, bool error_ok) { 476 assert(tag_at(which).is_method_type() || 477 (error_ok && tag_at(which).is_method_type_in_error()), "Corrupted constant pool"); 478 return int_at_addr(which); 479 } 480 public: 481 int method_handle_ref_kind_at(int which) { 482 return method_handle_ref_kind_at(which, false); 483 } 484 int method_handle_ref_kind_at_error_ok(int which) { 485 return method_handle_ref_kind_at(which, true); 486 } 487 int method_handle_index_at(int which) { 488 return method_handle_index_at(which, false); 489 } 490 int method_handle_index_at_error_ok(int which) { 491 return method_handle_index_at(which, true); 492 } 493 int method_type_index_at(int which) { 494 return method_type_index_at(which, false); 495 } 496 int method_type_index_at_error_ok(int which) { 497 return method_type_index_at(which, true); 498 } 499 500 // Derived queries: 501 Symbol method_handle_name_ref_at(int which) { 502 int member = method_handle_index_at(which); 503 return impl_name_ref_at(member, true); 504 } 505 Symbol method_handle_signature_ref_at(int which) { 506 int member = method_handle_index_at(which); 507 return impl_signature_ref_at(member, true); 508 } 509 int method_handle_klass_index_at(int which) { 510 int member = method_handle_index_at(which); 511 return impl_klass_ref_index_at(member, true); 512 } 513 Symbol method_type_signature_at(int which) { 514 int sym = method_type_index_at(which); 515 return symbol_at(sym); 516 } 517 518 int invoke_dynamic_name_and_type_ref_index_at(int which) { 519 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 520 return extract_high_short_from_int(int_at_addr(which)); 521 } 522 int invoke_dynamic_bootstrap_specifier_index(int which) { 523 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool"); 524 return extract_low_short_from_int(int_at_addr(which)); 525 } 526 int invoke_dynamic_operand_base(int which) { 527 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which); 528 return operand_offset_at(operands(), bootstrap_specifier_index); 529 } 530 // The first part of the operands array consists of an index into the second part. 531 // Extract a 32-bit index value from the first part. 532 static int operand_offset_at(Array operands, int bootstrap_specifier_index) { 533 int n = (bootstrap_specifier_index * 2); 534 assert(n >= 0 && n+2 <= operands->length(), "oob"); 535 // The first 32-bit index points to the beginning of the second part 536 // of the operands array. Make sure this index is in the first part. 537 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0), 538 operands->at(1))); 539 assert(second_part == 0 || n+2 <= second_part, "oob (2)"); 540 int offset = build_int_from_shorts(operands->at(n+0), 541 operands->at(n+1)); 542 // The offset itself must point into the second part of the array. 543 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)"); 544 return offset; 545 } 546 static void operand_offset_at_put(Array operands, int bootstrap_specifier_index, int offset) { 547 int n = bootstrap_specifier_index * 2; 548 assert(n >= 0 && n+2 <= operands->length(), "oob"); 549 operands->at_put(n+0, extract_low_short_from_int(offset)); 550 operands->at_put(n+1, extract_high_short_from_int(offset)); 551 } 552 static int operand_array_length(Array operands) { 553 if (operands == NULL || operands->length() == 0) return 0; 554 int second_part = operand_offset_at(operands, 0); 555 return (second_part / 2); 556 } 557 558 #ifdef ASSERT 559 // operand tuples fit together exactly, end to end 560 static int operand_limit_at(Array* operands, int bootstrap_specifier_index) { 561 int nextidx = bootstrap_specifier_index + 1; 562 if (nextidx == operand_array_length(operands)) 563 return operands->length(); 564 else 565 return operand_offset_at(operands, nextidx); 566 } 567 int invoke_dynamic_operand_limit(int which) { 568 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which); 569 return operand_limit_at(operands(), bootstrap_specifier_index); 570 } 571 #endif //ASSERT 572 573 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array): 574 enum { 575 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm 576 _indy_argc_offset = 1, // u2 argc 577 _indy_argv_offset = 2 // u2 argv[argc] 578 }; 579 580 // These functions are used in RedefineClasses for CP merge 581 582 int operand_offset_at(int bootstrap_specifier_index) { 583 assert(0 <= bootstrap_specifier_index && 584 bootstrap_specifier_index < operand_array_length(operands()), 585 "Corrupted CP operands"); 586 return operand_offset_at(operands(), bootstrap_specifier_index); 587 } 588 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) { 589 int offset = operand_offset_at(bootstrap_specifier_index); 590 return operands()->at(offset + _indy_bsm_offset); 591 } 592 int operand_argument_count_at(int bootstrap_specifier_index) { 593 int offset = operand_offset_at(bootstrap_specifier_index); 594 int argc = operands()->at(offset + _indy_argc_offset); 595 return argc; 596 } 597 int operand_argument_index_at(int bootstrap_specifier_index, int j) { 598 int offset = operand_offset_at(bootstrap_specifier_index); 599 return operands()->at(offset + _indy_argv_offset + j); 600 } 601 int operand_next_offset_at(int bootstrap_specifier_index) { 602 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset 603 + operand_argument_count_at(bootstrap_specifier_index); 604 return offset; 605 } 606 // Compare a bootsrap specifier in the operands arrays 607 bool compare_operand_to(int bootstrap_specifier_index1, constantPoolHandle cp2, 608 int bootstrap_specifier_index2, TRAPS); 609 // Find a bootsrap specifier in the operands array 610 int find_matching_operand(int bootstrap_specifier_index, constantPoolHandle search_cp, 611 int operands_cur_len, TRAPS); 612 // Resize the operands array with delta_len and delta_size 613 void resize_operands(int delta_len, int delta_size, TRAPS); 614 // Extend the operands array with the length and size of the ext_cp operands 615 void extend_operands(constantPoolHandle ext_cp, TRAPS); 616 // Shrink the operands array to a smaller array with new_len length 617 void shrink_operands(int new_len, TRAPS); 618 619 620 int invoke_dynamic_bootstrap_method_ref_index_at(int which) { 621 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 622 int op_base = invoke_dynamic_operand_base(which); 623 return operands()->at(op_base + _indy_bsm_offset); 624 } 625 int invoke_dynamic_argument_count_at(int which) { 626 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 627 int op_base = invoke_dynamic_operand_base(which); 628 int argc = operands()->at(op_base + _indy_argc_offset); 629 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc; 630 int next_offset = invoke_dynamic_operand_limit(which)); 631 assert(end_offset == next_offset, "matched ending"); 632 return argc; 633 } 634 int invoke_dynamic_argument_index_at(int which, int j) { 635 int op_base = invoke_dynamic_operand_base(which); 636 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset)); 637 assert((uint)j < (uint)argc, "oob"); 638 return operands()->at(op_base + indy_argv_offset + j); 639 } 640 641 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve, 642 // name_and_type_ref_index_at) all expect to be passed indices obtained 643 // directly from the bytecode. 644 // If the indices are meant to refer to fields or methods, they are 645 // actually rewritten constant pool cache indices. 646 // The routine remap_instruction_operand_from_cache manages the adjustment 647 // of these values back to constant pool indices. 648 649 // There are also "uncached" versions which do not adjust the operand index; see below. 650 651 // FIXME: Consider renaming these with a prefix "cached" to make the distinction clear. 652 // In a few cases (the verifier) there are uses before a cpcache has been built, 653 // which are handled by a dynamic check in remap_instruction_operand_from_cache. 654 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode. 655 656 // Lookup for entries consisting of (klass_index, name_and_type index) 657 Klass* klass_ref_at(int which, TRAPS); 658 Symbol* klass_ref_at_noresolve(int which); 659 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); } 660 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); } 661 662 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); } 663 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); } 664 665 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG 666 667 // Lookup for entries consisting of (name_index, signature_index) 668 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt) 669 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt) 670 671 BasicType basic_type_for_signature_at(int which); 672 673 // Resolve string constants (to prevent allocation during compilation) 674 void resolve_string_constants(TRAPS) { 675 constantPoolHandle h_this(THREAD, this); 676 resolve_string_constants_impl(h_this, CHECK); 677 } 678 679 // CDS support 680 void remove_unshareable_info(); 681 void restore_unshareable_info(TRAPS); 682 bool resolve_class_constants(TRAPS); 683 // The ConstantPool vtable is restored by this call when the ConstantPool is 684 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for 685 // all the gory details. SA, dtrace and pstack helpers distinguish metadata 686 // by their vtable. 687 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); } 688 689 private: 690 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 }; 691 public: 692 693 // Resolve late bound constants. 694 oop resolve_constant_at(int index, TRAPS) { 695 constantPoolHandle h_this(THREAD, this); 696 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD); 697 } 698 699 oop resolve_cached_constant_at(int cache_index, TRAPS) { 700 constantPoolHandle h_this(THREAD, this); 701 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD); 702 } 703 704 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) { 705 constantPoolHandle h_this(THREAD, this); 706 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD); 707 } 708 709 oop resolve_bootstrap_specifier_at(int index, TRAPS) { 710 constantPoolHandle h_this(THREAD, this); 711 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD); 712 } 713 714 // Klass name matches name at offset 715 bool klass_name_at_matches(instanceKlassHandle k, int which); 716 717 // Sizing 718 int length() const { return _length; } 719 void set_length(int length) { _length = length; } 720 721 // Tells whether index is within bounds. 722 bool is_within_bounds(int index) const { 723 return 0 <= index && index < length(); 724 } 725 726 // Sizing (in words) 727 static int header_size() { return sizeof(ConstantPool)/HeapWordSize; } 728 static int size(int length) { return align_object_size(header_size() + length); } 729 int size() const { return size(length()); } 730 #if INCLUDE_SERVICES 731 void collect_statistics(KlassSizeStats sz) const; 732 #endif 733 734 friend class ClassFileParser; 735 friend class SystemDictionary; 736 737 // Used by compiler to prevent classloading. 738 static Method* method_at_if_loaded (constantPoolHandle this_cp, int which); 739 static bool has_appendix_at_if_loaded (constantPoolHandle this_cp, int which); 740 static oop appendix_at_if_loaded (constantPoolHandle this_cp, int which); 741 static bool has_method_type_at_if_loaded (constantPoolHandle this_cp, int which); 742 static oop method_type_at_if_loaded (constantPoolHandle this_cp, int which); 743 static Klass* klass_at_if_loaded (constantPoolHandle this_cp, int which); 744 static Klass* klass_ref_at_if_loaded (constantPoolHandle this_cp, int which); 745 746 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the 747 // future by other Java code. These take constant pool indices rather than 748 // constant pool cache indices as do the peer methods above. 749 Symbol* uncached_klass_ref_at_noresolve(int which); 750 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); } 751 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); } 752 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); } 753 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); } 754 755 // Sharing 756 int pre_resolve_shared_klasses(TRAPS); 757 758 // Debugging 759 const char* printable_name_at(int which) PRODUCT_RETURN0; 760 761 #ifdef ASSERT 762 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices 763 #else 764 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op 765 #endif //ASSERT 766 767 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) { 768 if (invokedynamic_ok && is_invokedynamic_index(raw_index)) 769 return decode_invokedynamic_index(raw_index); 770 else 771 return raw_index - CPCACHE_INDEX_TAG; 772 } 773 774 private: 775 776 void set_resolved_references(jobject s) { _resolved_references = s; } 777 Array reference_map() const { return _reference_map; } 778 void set_reference_map(Array* o) { _reference_map = o; } 779 780 // patch JSR 292 resolved references after the class is linked. 781 void patch_resolved_references(GrowableArray* cp_patches); 782 783 Symbol* impl_name_ref_at(int which, bool uncached); 784 Symbol* impl_signature_ref_at(int which, bool uncached); 785 int impl_klass_ref_index_at(int which, bool uncached); 786 int impl_name_and_type_ref_index_at(int which, bool uncached); 787 788 // Used while constructing constant pool (only by ClassFileParser) 789 jint klass_index_at(int which) { 790 assert(tag_at(which).is_klass_index(), "Corrupted constant pool"); 791 return int_at_addr(which); 792 } 793 794 jint string_index_at(int which) { 795 assert(tag_at(which).is_string_index(), "Corrupted constant pool"); 796 return int_at_addr(which); 797 } 798 799 // Performs the LinkResolver checks 800 static void verify_constant_pool_resolve(constantPoolHandle this_cp, KlassHandle klass, TRAPS); 801 802 // Implementation of methods that needs an exposed 'this' pointer, in order to 803 // handle GC while executing the method 804 static Klass klass_at_impl(constantPoolHandle this_cp, int which, 805 bool save_resolution_error, TRAPS); 806 static oop string_at_impl(constantPoolHandle this_cp, int which, int obj_index, TRAPS); 807 808 static void trace_class_resolution(constantPoolHandle this_cp, KlassHandle k); 809 810 // Resolve string constants (to prevent allocation during compilation) 811 static void resolve_string_constants_impl(constantPoolHandle this_cp, TRAPS); 812 813 static oop resolve_constant_at_impl(constantPoolHandle this_cp, int index, int cache_index, TRAPS); 814 static oop resolve_bootstrap_specifier_at_impl(constantPoolHandle this_cp, int index, TRAPS); 815 816 // Exception handling 817 static void throw_resolution_error(constantPoolHandle this_cp, int which, TRAPS); 818 static Symbol exception_message(constantPoolHandle this_cp, int which, constantTag tag, oop pending_exception); 819 static void save_and_throw_exception(constantPoolHandle this_cp, int which, constantTag tag, TRAPS); 820 821 public: 822 // Merging ConstantPool* support: 823 bool compare_entry_to(int index1, constantPoolHandle cp2, int index2, TRAPS); 824 void copy_cp_to(int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS) { 825 constantPoolHandle h_this(THREAD, this); 826 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD); 827 } 828 static void copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS); 829 static void copy_entry_to(constantPoolHandle from_cp, int from_i, constantPoolHandle to_cp, int to_i, TRAPS); 830 static void copy_operands(constantPoolHandle from_cp, constantPoolHandle to_cp, TRAPS); 831 int find_matching_entry(int pattern_i, constantPoolHandle search_cp, TRAPS); 832 int version() const { return _saved._version; } 833 void set_version(int version) { _saved._version = version; } 834 void increment_and_save_version(int version) { 835 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow 836 } 837 838 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; } 839 int resolved_reference_length() const { return _saved._resolved_reference_length; } 840 841 // Decrease ref counts of symbols that are in the constant pool 842 // when the holder class is unloaded 843 void unreference_symbols(); 844 845 // Deallocate constant pool for RedefineClasses 846 void deallocate_contents(ClassLoaderData* loader_data); 847 void release_C_heap_structures(); 848 849 // JVMTI accesss - GetConstantPool, RetransformClasses, ... 850 friend class JvmtiConstantPoolReconstituter; 851 852 private: 853 jint cpool_entry_size(jint idx); 854 jint hash_entries_to(SymbolHashMap symmap, SymbolHashMap classmap); 855 856 // Copy cpool bytes into byte array. 857 // Returns: 858 // int > 0, count of the raw cpool bytes that have been copied 859 // 0, OutOfMemory error 860 // -1, Internal error 861 int copy_cpool_bytes(int cpool_size, 862 SymbolHashMap tbl, 863 unsigned char bytes); 864 865 public: 866 // Verify 867 void verify_on(outputStream st); 868 869 // Printing 870 void print_on(outputStream st) const; 871 void print_value_on(outputStream* st) const; 872 void print_entry_on(int index, outputStream* st); 873 874 const char* internal_name() const { return "{constant pool}"; } 875 876 #ifndef PRODUCT 877 // Compile the world support 878 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS); 879 #endif 880 }; 881 882 class SymbolHashMapEntry : public CHeapObj { 883 private: 884 unsigned int _hash; // 32-bit hash for item 885 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket 886 Symbol* _symbol; // 1-st part of the mapping: symbol => value 887 u2 _value; // 2-nd part of the mapping: symbol => value 888 889 public: 890 unsigned int hash() const { return _hash; } 891 void set_hash(unsigned int hash) { _hash = hash; } 892 893 SymbolHashMapEntry* next() const { return _next; } 894 void set_next(SymbolHashMapEntry* next) { _next = next; } 895 896 Symbol* symbol() const { return _symbol; } 897 void set_symbol(Symbol* sym) { _symbol = sym; } 898 899 u2 value() const { return _value; } 900 void set_value(u2 value) { _value = value; } 901 902 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value) 903 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {} 904 905 }; // End SymbolHashMapEntry class 906 907 908 class SymbolHashMapBucket : public CHeapObj { 909 910 private: 911 SymbolHashMapEntry* _entry; 912 913 public: 914 SymbolHashMapEntry* entry() const { return _entry; } 915 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; } 916 void clear() { _entry = NULL; } 917 918 }; // End SymbolHashMapBucket class 919 920 921 class SymbolHashMap: public CHeapObj { 922 923 private: 924 // Default number of entries in the table 925 enum SymbolHashMap_Constants { 926 _Def_HashMap_Size = 256 927 }; 928 929 int _table_size; 930 SymbolHashMapBucket* _buckets; 931 932 void initialize_table(int table_size) { 933 _table_size = table_size; 934 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol); 935 for (int index = 0; index < table_size; index++) { 936 _buckets[index].clear(); 937 } 938 } 939 940 public: 941 942 int table_size() const { return _table_size; } 943 944 SymbolHashMap() { initialize_table(_Def_HashMap_Size); } 945 SymbolHashMap(int table_size) { initialize_table(table_size); } 946 947 // hash P(31) from Kernighan & Ritchie 948 static unsigned int compute_hash(const char* str, int len) { 949 unsigned int hash = 0; 950 while (len-- > 0) { 951 hash = 31hash + (unsigned) str; 952 str++; 953 } 954 return hash; 955 } 956 957 SymbolHashMapEntry bucket(int i) { 958 return _buckets[i].entry(); 959 } 960 961 void add_entry(Symbol sym, u2 value); 962 SymbolHashMapEntry* find_entry(Symbol* sym); 963 964 u2 symbol_to_value(Symbol* sym) { 965 SymbolHashMapEntry entry = find_entry(sym); 966 return (entry == NULL) ? 0 : entry->value(); 967 } 968 969 ~SymbolHashMap() { 970 SymbolHashMapEntry next; 971 for (int i = 0; i < _table_size; i++) { 972 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) { 973 next = cur->next(); 974 delete(cur); 975 } 976 } 977 delete _buckets; 978 } 979 }; // End SymbolHashMap class 980 981 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP