constantPool.hpp revision 7418:ef7449e07592
1/* 2 * Copyright (c) 1997, 2014, 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 46class SymbolHashMap; 47 48class CPSlot VALUE_OBJ_CLASS_SPEC { 49 intptr_t _ptr; 50 public: 51 CPSlot(intptr_t ptr): _ptr(ptr) {} 52 CPSlot(Klass* ptr): _ptr((intptr_t)ptr) {} 53 CPSlot(Symbol* ptr): _ptr((intptr_t)ptr | 1) {} 54 55 intptr_t value() { return _ptr; } 56 bool is_resolved() { return (_ptr & 1) == 0; } 57 bool is_unresolved() { return (_ptr & 1) == 1; } 58 59 Symbol* get_symbol() { 60 assert(is_unresolved(), "bad call"); 61 return (Symbol*)(_ptr & ~1); 62 } 63 Klass* get_klass() { 64 assert(is_resolved(), "bad call"); 65 return (Klass*)_ptr; 66 } 67}; 68 69class KlassSizeStats; 70 71class ConstantPool : public Metadata { 72 friend class VMStructs; 73 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast 74 friend class Universe; // For null constructor 75 private: 76 Array<u1>* _tags; // the tag array describing the constant pool's contents 77 ConstantPoolCache* _cache; // the cache holding interpreter runtime information 78 InstanceKlass* _pool_holder; // the corresponding class 79 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty 80 81 // Array of resolved objects from the constant pool and map from resolved 82 // object index to original constant pool index 83 jobject _resolved_references; 84 Array<u2>* _reference_map; 85 86 enum { 87 _has_preresolution = 1, // Flags 88 _on_stack = 2 89 }; 90 91 int _flags; // old fashioned bit twiddling 92 int _length; // number of elements in the array 93 94 union { 95 // set for CDS to restore resolved references 96 int _resolved_reference_length; 97 // keeps version number for redefined classes (used in backtrace) 98 int _version; 99 } _saved; 100 101 void set_tags(Array<u1>* tags) { _tags = tags; } 102 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); } 103 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); } 104 105 u1* tag_addr_at(int which) const { return tags()->adr_at(which); } 106 107 void set_operands(Array<u2>* operands) { _operands = operands; } 108 109 int flags() const { return _flags; } 110 void set_flags(int f) { _flags = f; } 111 112 private: 113 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); } 114 115 CPSlot slot_at(int which) { 116 assert(is_within_bounds(which), "index out of bounds"); 117 // Uses volatile because the klass slot changes without a lock. 118 volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which)); 119 assert(adr != 0 || which == 0, "cp entry for klass should not be zero"); 120 return CPSlot(adr); 121 } 122 123 void slot_at_put(int which, CPSlot s) const { 124 assert(is_within_bounds(which), "index out of bounds"); 125 assert(s.value() != 0, "Caught something"); 126 *(intptr_t*)&base()[which] = s.value(); 127 } 128 intptr_t* obj_at_addr_raw(int which) const { 129 assert(is_within_bounds(which), "index out of bounds"); 130 return (intptr_t*) &base()[which]; 131 } 132 133 jint* int_at_addr(int which) const { 134 assert(is_within_bounds(which), "index out of bounds"); 135 return (jint*) &base()[which]; 136 } 137 138 jlong* long_at_addr(int which) const { 139 assert(is_within_bounds(which), "index out of bounds"); 140 return (jlong*) &base()[which]; 141 } 142 143 jfloat* float_at_addr(int which) const { 144 assert(is_within_bounds(which), "index out of bounds"); 145 return (jfloat*) &base()[which]; 146 } 147 148 jdouble* double_at_addr(int which) const { 149 assert(is_within_bounds(which), "index out of bounds"); 150 return (jdouble*) &base()[which]; 151 } 152 153 ConstantPool(Array<u1>* tags); 154 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); } 155 public: 156 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS); 157 158 bool is_constantPool() const volatile { return true; } 159 160 Array<u1>* tags() const { return _tags; } 161 Array<u2>* operands() const { return _operands; } 162 163 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; } 164 void set_has_preresolution() { _flags |= _has_preresolution; } 165 166 // Redefine classes support. If a method refering to this constant pool 167 // is on the executing stack, or as a handle in vm code, this constant pool 168 // can't be removed from the set of previous versions saved in the instance 169 // class. 170 bool on_stack() const { return (_flags &_on_stack) != 0; } 171 void set_on_stack(const bool value); 172 173 // Klass holding pool 174 InstanceKlass* pool_holder() const { return _pool_holder; } 175 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; } 176 InstanceKlass** pool_holder_addr() { return &_pool_holder; } 177 178 // Interpreter runtime support 179 ConstantPoolCache* cache() const { return _cache; } 180 void set_cache(ConstantPoolCache* cache){ _cache = cache; } 181 182 // Create object cache in the constant pool 183 void initialize_resolved_references(ClassLoaderData* loader_data, 184 intStack reference_map, 185 int constant_pool_map_length, 186 TRAPS); 187 188 // resolved strings, methodHandles and callsite objects from the constant pool 189 objArrayOop resolved_references() const; 190 // mapping resolved object array indexes to cp indexes and back. 191 int object_to_cp_index(int index) { return _reference_map->at(index); } 192 int cp_to_object_index(int index); 193 194 // Invokedynamic indexes. 195 // They must look completely different from normal indexes. 196 // The main reason is that byte swapping is sometimes done on normal indexes. 197 // Finally, it is helpful for debugging to tell the two apart. 198 static bool is_invokedynamic_index(int i) { return (i < 0); } 199 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; } 200 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; } 201 202 203 // The invokedynamic points at a CP cache entry. This entry points back 204 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry 205 // in the resolved_references array (which provides the appendix argument). 206 int invokedynamic_cp_cache_index(int index) const { 207 assert (is_invokedynamic_index(index), "should be a invokedynamic index"); 208 int cache_index = decode_invokedynamic_index(index); 209 return cache_index; 210 } 211 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const { 212 // decode index that invokedynamic points to. 213 int cp_cache_index = invokedynamic_cp_cache_index(index); 214 return cache()->entry_at(cp_cache_index); 215 } 216 217 // Assembly code support 218 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); } 219 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); } 220 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); } 221 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPool, _resolved_references); } 222 223 // Storing constants 224 225 void klass_at_put(int which, Klass* k) { 226 assert(k != NULL, "resolved class shouldn't be null"); 227 assert(is_within_bounds(which), "index out of bounds"); 228 OrderAccess::release_store_ptr((Klass* volatile *)obj_at_addr_raw(which), k); 229 // The interpreter assumes when the tag is stored, the klass is resolved 230 // and the Klass* is a klass rather than a Symbol*, so we need 231 // hardware store ordering here. 232 release_tag_at_put(which, JVM_CONSTANT_Class); 233 } 234 235 // For temporary use while constructing constant pool 236 void klass_index_at_put(int which, int name_index) { 237 tag_at_put(which, JVM_CONSTANT_ClassIndex); 238 *int_at_addr(which) = name_index; 239 } 240 241 // Temporary until actual use 242 void unresolved_klass_at_put(int which, Symbol* s) { 243 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass); 244 slot_at_put(which, s); 245 } 246 247 void method_handle_index_at_put(int which, int ref_kind, int ref_index) { 248 tag_at_put(which, JVM_CONSTANT_MethodHandle); 249 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind; 250 } 251 252 void method_type_index_at_put(int which, int ref_index) { 253 tag_at_put(which, JVM_CONSTANT_MethodType); 254 *int_at_addr(which) = ref_index; 255 } 256 257 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) { 258 tag_at_put(which, JVM_CONSTANT_InvokeDynamic); 259 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index; 260 } 261 262 void unresolved_string_at_put(int which, Symbol* s) { 263 release_tag_at_put(which, JVM_CONSTANT_String); 264 *symbol_at_addr(which) = s; 265 } 266 267 void int_at_put(int which, jint i) { 268 tag_at_put(which, JVM_CONSTANT_Integer); 269 *int_at_addr(which) = i; 270 } 271 272 void long_at_put(int which, jlong l) { 273 tag_at_put(which, JVM_CONSTANT_Long); 274 // *long_at_addr(which) = l; 275 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l)); 276 } 277 278 void float_at_put(int which, jfloat f) { 279 tag_at_put(which, JVM_CONSTANT_Float); 280 *float_at_addr(which) = f; 281 } 282 283 void double_at_put(int which, jdouble d) { 284 tag_at_put(which, JVM_CONSTANT_Double); 285 // *double_at_addr(which) = d; 286 // u8 temp = *(u8*) &d; 287 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d)); 288 } 289 290 Symbol** symbol_at_addr(int which) const { 291 assert(is_within_bounds(which), "index out of bounds"); 292 return (Symbol**) &base()[which]; 293 } 294 295 void symbol_at_put(int which, Symbol* s) { 296 assert(s->refcount() != 0, "should have nonzero refcount"); 297 tag_at_put(which, JVM_CONSTANT_Utf8); 298 *symbol_at_addr(which) = s; 299 } 300 301 void string_at_put(int which, int obj_index, oop str) { 302 resolved_references()->obj_at_put(obj_index, str); 303 } 304 305 // For temporary use while constructing constant pool 306 void string_index_at_put(int which, int string_index) { 307 tag_at_put(which, JVM_CONSTANT_StringIndex); 308 *int_at_addr(which) = string_index; 309 } 310 311 void field_at_put(int which, int class_index, int name_and_type_index) { 312 tag_at_put(which, JVM_CONSTANT_Fieldref); 313 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; 314 } 315 316 void method_at_put(int which, int class_index, int name_and_type_index) { 317 tag_at_put(which, JVM_CONSTANT_Methodref); 318 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; 319 } 320 321 void interface_method_at_put(int which, int class_index, int name_and_type_index) { 322 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref); 323 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice 324 } 325 326 void name_and_type_at_put(int which, int name_index, int signature_index) { 327 tag_at_put(which, JVM_CONSTANT_NameAndType); 328 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice 329 } 330 331 // Tag query 332 333 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); } 334 335 // Fetching constants 336 337 Klass* klass_at(int which, TRAPS) { 338 constantPoolHandle h_this(THREAD, this); 339 return klass_at_impl(h_this, which, true, THREAD); 340 } 341 342 // Version of klass_at that doesn't save the resolution error, called during deopt 343 Klass* klass_at_ignore_error(int which, TRAPS) { 344 constantPoolHandle h_this(THREAD, this); 345 return klass_at_impl(h_this, which, false, THREAD); 346 } 347 348 Symbol* klass_name_at(int which); // Returns the name, w/o resolving. 349 350 Klass* resolved_klass_at(int which) const { // Used by Compiler 351 guarantee(tag_at(which).is_klass(), "Corrupted constant pool"); 352 // Must do an acquire here in case another thread resolved the klass 353 // behind our back, lest we later load stale values thru the oop. 354 return CPSlot((Klass*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_klass(); 355 } 356 357 // RedefineClasses() API support: 358 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); } 359 360 jint int_at(int which) { 361 assert(tag_at(which).is_int(), "Corrupted constant pool"); 362 return *int_at_addr(which); 363 } 364 365 jlong long_at(int which) { 366 assert(tag_at(which).is_long(), "Corrupted constant pool"); 367 // return *long_at_addr(which); 368 u8 tmp = Bytes::get_native_u8((address)&base()[which]); 369 return *((jlong*)&tmp); 370 } 371 372 jfloat float_at(int which) { 373 assert(tag_at(which).is_float(), "Corrupted constant pool"); 374 return *float_at_addr(which); 375 } 376 377 jdouble double_at(int which) { 378 assert(tag_at(which).is_double(), "Corrupted constant pool"); 379 u8 tmp = Bytes::get_native_u8((address)&base()[which]); 380 return *((jdouble*)&tmp); 381 } 382 383 Symbol* symbol_at(int which) { 384 assert(tag_at(which).is_utf8(), "Corrupted constant pool"); 385 return *symbol_at_addr(which); 386 } 387 388 oop string_at(int which, int obj_index, TRAPS) { 389 constantPoolHandle h_this(THREAD, this); 390 return string_at_impl(h_this, which, obj_index, THREAD); 391 } 392 oop string_at(int which, TRAPS) { 393 int obj_index = cp_to_object_index(which); 394 return string_at(which, obj_index, THREAD); 395 } 396 397 // Version that can be used before string oop array is created. 398 oop uncached_string_at(int which, TRAPS); 399 400 // A "pseudo-string" is an non-string oop that has found its way into 401 // a String entry. 402 // This can happen if the user patches a live 403 // object into a CONSTANT_String entry of an anonymous class. 404 // Method oops internally created for method handles may also 405 // use pseudo-strings to link themselves to related metaobjects. 406 407 bool is_pseudo_string_at(int which) { 408 // A pseudo string is a string that doesn't have a symbol in the cpSlot 409 return unresolved_string_at(which) == NULL; 410 } 411 412 oop pseudo_string_at(int which, int obj_index) { 413 assert(tag_at(which).is_string(), "Corrupted constant pool"); 414 assert(unresolved_string_at(which) == NULL, "shouldn't have symbol"); 415 oop s = resolved_references()->obj_at(obj_index); 416 return s; 417 } 418 419 oop pseudo_string_at(int which) { 420 assert(tag_at(which).is_string(), "Corrupted constant pool"); 421 assert(unresolved_string_at(which) == NULL, "shouldn't have symbol"); 422 int obj_index = cp_to_object_index(which); 423 oop s = resolved_references()->obj_at(obj_index); 424 return s; 425 } 426 427 void pseudo_string_at_put(int which, int obj_index, oop x) { 428 assert(tag_at(which).is_string(), "Corrupted constant pool"); 429 unresolved_string_at_put(which, NULL); // indicates patched string 430 string_at_put(which, obj_index, x); // this works just fine 431 } 432 433 // only called when we are sure a string entry is already resolved (via an 434 // earlier string_at call. 435 oop resolved_string_at(int which) { 436 assert(tag_at(which).is_string(), "Corrupted constant pool"); 437 // Must do an acquire here in case another thread resolved the klass 438 // behind our back, lest we later load stale values thru the oop. 439 // we might want a volatile_obj_at in ObjArrayKlass. 440 int obj_index = cp_to_object_index(which); 441 return resolved_references()->obj_at(obj_index); 442 } 443 444 Symbol* unresolved_string_at(int which) { 445 assert(tag_at(which).is_string(), "Corrupted constant pool"); 446 Symbol* s = *symbol_at_addr(which); 447 return s; 448 } 449 450 // Returns an UTF8 for a CONSTANT_String entry at a given index. 451 // UTF8 char* representation was chosen to avoid conversion of 452 // java_lang_Strings at resolved entries into Symbol*s 453 // or vice versa. 454 // Caller is responsible for checking for pseudo-strings. 455 char* string_at_noresolve(int which); 456 457 jint name_and_type_at(int which) { 458 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool"); 459 return *int_at_addr(which); 460 } 461 462 private: 463 int method_handle_ref_kind_at(int which, bool error_ok) { 464 assert(tag_at(which).is_method_handle() || 465 (error_ok && tag_at(which).is_method_handle_in_error()), "Corrupted constant pool"); 466 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits 467 } 468 int method_handle_index_at(int which, bool error_ok) { 469 assert(tag_at(which).is_method_handle() || 470 (error_ok && tag_at(which).is_method_handle_in_error()), "Corrupted constant pool"); 471 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits 472 } 473 int method_type_index_at(int which, bool error_ok) { 474 assert(tag_at(which).is_method_type() || 475 (error_ok && tag_at(which).is_method_type_in_error()), "Corrupted constant pool"); 476 return *int_at_addr(which); 477 } 478 public: 479 int method_handle_ref_kind_at(int which) { 480 return method_handle_ref_kind_at(which, false); 481 } 482 int method_handle_ref_kind_at_error_ok(int which) { 483 return method_handle_ref_kind_at(which, true); 484 } 485 int method_handle_index_at(int which) { 486 return method_handle_index_at(which, false); 487 } 488 int method_handle_index_at_error_ok(int which) { 489 return method_handle_index_at(which, true); 490 } 491 int method_type_index_at(int which) { 492 return method_type_index_at(which, false); 493 } 494 int method_type_index_at_error_ok(int which) { 495 return method_type_index_at(which, true); 496 } 497 498 // Derived queries: 499 Symbol* method_handle_name_ref_at(int which) { 500 int member = method_handle_index_at(which); 501 return impl_name_ref_at(member, true); 502 } 503 Symbol* method_handle_signature_ref_at(int which) { 504 int member = method_handle_index_at(which); 505 return impl_signature_ref_at(member, true); 506 } 507 int method_handle_klass_index_at(int which) { 508 int member = method_handle_index_at(which); 509 return impl_klass_ref_index_at(member, true); 510 } 511 Symbol* method_type_signature_at(int which) { 512 int sym = method_type_index_at(which); 513 return symbol_at(sym); 514 } 515 516 int invoke_dynamic_name_and_type_ref_index_at(int which) { 517 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 518 return extract_high_short_from_int(*int_at_addr(which)); 519 } 520 int invoke_dynamic_bootstrap_specifier_index(int which) { 521 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool"); 522 return extract_low_short_from_int(*int_at_addr(which)); 523 } 524 int invoke_dynamic_operand_base(int which) { 525 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which); 526 return operand_offset_at(operands(), bootstrap_specifier_index); 527 } 528 // The first part of the operands array consists of an index into the second part. 529 // Extract a 32-bit index value from the first part. 530 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) { 531 int n = (bootstrap_specifier_index * 2); 532 assert(n >= 0 && n+2 <= operands->length(), "oob"); 533 // The first 32-bit index points to the beginning of the second part 534 // of the operands array. Make sure this index is in the first part. 535 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0), 536 operands->at(1))); 537 assert(second_part == 0 || n+2 <= second_part, "oob (2)"); 538 int offset = build_int_from_shorts(operands->at(n+0), 539 operands->at(n+1)); 540 // The offset itself must point into the second part of the array. 541 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)"); 542 return offset; 543 } 544 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) { 545 int n = bootstrap_specifier_index * 2; 546 assert(n >= 0 && n+2 <= operands->length(), "oob"); 547 operands->at_put(n+0, extract_low_short_from_int(offset)); 548 operands->at_put(n+1, extract_high_short_from_int(offset)); 549 } 550 static int operand_array_length(Array<u2>* operands) { 551 if (operands == NULL || operands->length() == 0) return 0; 552 int second_part = operand_offset_at(operands, 0); 553 return (second_part / 2); 554 } 555 556#ifdef ASSERT 557 // operand tuples fit together exactly, end to end 558 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) { 559 int nextidx = bootstrap_specifier_index + 1; 560 if (nextidx == operand_array_length(operands)) 561 return operands->length(); 562 else 563 return operand_offset_at(operands, nextidx); 564 } 565 int invoke_dynamic_operand_limit(int which) { 566 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which); 567 return operand_limit_at(operands(), bootstrap_specifier_index); 568 } 569#endif //ASSERT 570 571 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array): 572 enum { 573 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm 574 _indy_argc_offset = 1, // u2 argc 575 _indy_argv_offset = 2 // u2 argv[argc] 576 }; 577 578 // These functions are used in RedefineClasses for CP merge 579 580 int operand_offset_at(int bootstrap_specifier_index) { 581 assert(0 <= bootstrap_specifier_index && 582 bootstrap_specifier_index < operand_array_length(operands()), 583 "Corrupted CP operands"); 584 return operand_offset_at(operands(), bootstrap_specifier_index); 585 } 586 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) { 587 int offset = operand_offset_at(bootstrap_specifier_index); 588 return operands()->at(offset + _indy_bsm_offset); 589 } 590 int operand_argument_count_at(int bootstrap_specifier_index) { 591 int offset = operand_offset_at(bootstrap_specifier_index); 592 int argc = operands()->at(offset + _indy_argc_offset); 593 return argc; 594 } 595 int operand_argument_index_at(int bootstrap_specifier_index, int j) { 596 int offset = operand_offset_at(bootstrap_specifier_index); 597 return operands()->at(offset + _indy_argv_offset + j); 598 } 599 int operand_next_offset_at(int bootstrap_specifier_index) { 600 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset 601 + operand_argument_count_at(bootstrap_specifier_index); 602 return offset; 603 } 604 // Compare a bootsrap specifier in the operands arrays 605 bool compare_operand_to(int bootstrap_specifier_index1, constantPoolHandle cp2, 606 int bootstrap_specifier_index2, TRAPS); 607 // Find a bootsrap specifier in the operands array 608 int find_matching_operand(int bootstrap_specifier_index, constantPoolHandle search_cp, 609 int operands_cur_len, TRAPS); 610 // Resize the operands array with delta_len and delta_size 611 void resize_operands(int delta_len, int delta_size, TRAPS); 612 // Extend the operands array with the length and size of the ext_cp operands 613 void extend_operands(constantPoolHandle ext_cp, TRAPS); 614 // Shrink the operands array to a smaller array with new_len length 615 void shrink_operands(int new_len, TRAPS); 616 617 618 int invoke_dynamic_bootstrap_method_ref_index_at(int which) { 619 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 620 int op_base = invoke_dynamic_operand_base(which); 621 return operands()->at(op_base + _indy_bsm_offset); 622 } 623 int invoke_dynamic_argument_count_at(int which) { 624 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 625 int op_base = invoke_dynamic_operand_base(which); 626 int argc = operands()->at(op_base + _indy_argc_offset); 627 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc; 628 int next_offset = invoke_dynamic_operand_limit(which)); 629 assert(end_offset == next_offset, "matched ending"); 630 return argc; 631 } 632 int invoke_dynamic_argument_index_at(int which, int j) { 633 int op_base = invoke_dynamic_operand_base(which); 634 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset)); 635 assert((uint)j < (uint)argc, "oob"); 636 return operands()->at(op_base + _indy_argv_offset + j); 637 } 638 639 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve, 640 // name_and_type_ref_index_at) all expect to be passed indices obtained 641 // directly from the bytecode. 642 // If the indices are meant to refer to fields or methods, they are 643 // actually rewritten constant pool cache indices. 644 // The routine remap_instruction_operand_from_cache manages the adjustment 645 // of these values back to constant pool indices. 646 647 // There are also "uncached" versions which do not adjust the operand index; see below. 648 649 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear. 650 // In a few cases (the verifier) there are uses before a cpcache has been built, 651 // which are handled by a dynamic check in remap_instruction_operand_from_cache. 652 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode. 653 654 // Lookup for entries consisting of (klass_index, name_and_type index) 655 Klass* klass_ref_at(int which, TRAPS); 656 Symbol* klass_ref_at_noresolve(int which); 657 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); } 658 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); } 659 660 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); } 661 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); } 662 663 // Lookup for entries consisting of (name_index, signature_index) 664 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt) 665 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt) 666 667 BasicType basic_type_for_signature_at(int which); 668 669 // Resolve string constants (to prevent allocation during compilation) 670 void resolve_string_constants(TRAPS) { 671 constantPoolHandle h_this(THREAD, this); 672 resolve_string_constants_impl(h_this, CHECK); 673 } 674 675 // CDS support 676 void remove_unshareable_info(); 677 void restore_unshareable_info(TRAPS); 678 bool resolve_class_constants(TRAPS); 679 // The ConstantPool vtable is restored by this call when the ConstantPool is 680 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for 681 // all the gory details. SA, dtrace and pstack helpers distinguish metadata 682 // by their vtable. 683 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); } 684 685 private: 686 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 }; 687 public: 688 689 // Resolve late bound constants. 690 oop resolve_constant_at(int index, TRAPS) { 691 constantPoolHandle h_this(THREAD, this); 692 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD); 693 } 694 695 oop resolve_cached_constant_at(int cache_index, TRAPS) { 696 constantPoolHandle h_this(THREAD, this); 697 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD); 698 } 699 700 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) { 701 constantPoolHandle h_this(THREAD, this); 702 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD); 703 } 704 705 oop resolve_bootstrap_specifier_at(int index, TRAPS) { 706 constantPoolHandle h_this(THREAD, this); 707 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD); 708 } 709 710 // Klass name matches name at offset 711 bool klass_name_at_matches(instanceKlassHandle k, int which); 712 713 // Sizing 714 int length() const { return _length; } 715 void set_length(int length) { _length = length; } 716 717 // Tells whether index is within bounds. 718 bool is_within_bounds(int index) const { 719 return 0 <= index && index < length(); 720 } 721 722 // Sizing (in words) 723 static int header_size() { return sizeof(ConstantPool)/HeapWordSize; } 724 static int size(int length) { return align_object_size(header_size() + length); } 725 int size() const { return size(length()); } 726#if INCLUDE_SERVICES 727 void collect_statistics(KlassSizeStats *sz) const; 728#endif 729 730 friend class ClassFileParser; 731 friend class SystemDictionary; 732 733 // Used by compiler to prevent classloading. 734 static Method* method_at_if_loaded (constantPoolHandle this_cp, int which); 735 static bool has_appendix_at_if_loaded (constantPoolHandle this_cp, int which); 736 static oop appendix_at_if_loaded (constantPoolHandle this_cp, int which); 737 static bool has_method_type_at_if_loaded (constantPoolHandle this_cp, int which); 738 static oop method_type_at_if_loaded (constantPoolHandle this_cp, int which); 739 static Klass* klass_at_if_loaded (constantPoolHandle this_cp, int which); 740 static Klass* klass_ref_at_if_loaded (constantPoolHandle this_cp, int which); 741 742 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the 743 // future by other Java code. These take constant pool indices rather than 744 // constant pool cache indices as do the peer methods above. 745 Symbol* uncached_klass_ref_at_noresolve(int which); 746 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); } 747 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); } 748 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); } 749 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); } 750 751 // Sharing 752 int pre_resolve_shared_klasses(TRAPS); 753 754 // Debugging 755 const char* printable_name_at(int which) PRODUCT_RETURN0; 756 757#ifdef ASSERT 758 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices 759#else 760 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op 761#endif //ASSERT 762 763 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) { 764 if (invokedynamic_ok && is_invokedynamic_index(raw_index)) 765 return decode_invokedynamic_index(raw_index); 766 else 767 return raw_index - CPCACHE_INDEX_TAG; 768 } 769 770 private: 771 772 void set_resolved_references(jobject s) { _resolved_references = s; } 773 Array<u2>* reference_map() const { return _reference_map; } 774 void set_reference_map(Array<u2>* o) { _reference_map = o; } 775 776 // patch JSR 292 resolved references after the class is linked. 777 void patch_resolved_references(GrowableArray<Handle>* cp_patches); 778 779 Symbol* impl_name_ref_at(int which, bool uncached); 780 Symbol* impl_signature_ref_at(int which, bool uncached); 781 int impl_klass_ref_index_at(int which, bool uncached); 782 int impl_name_and_type_ref_index_at(int which, bool uncached); 783 784 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG 785 786 // Used while constructing constant pool (only by ClassFileParser) 787 jint klass_index_at(int which) { 788 assert(tag_at(which).is_klass_index(), "Corrupted constant pool"); 789 return *int_at_addr(which); 790 } 791 792 jint string_index_at(int which) { 793 assert(tag_at(which).is_string_index(), "Corrupted constant pool"); 794 return *int_at_addr(which); 795 } 796 797 // Performs the LinkResolver checks 798 static void verify_constant_pool_resolve(constantPoolHandle this_cp, KlassHandle klass, TRAPS); 799 800 // Implementation of methods that needs an exposed 'this' pointer, in order to 801 // handle GC while executing the method 802 static Klass* klass_at_impl(constantPoolHandle this_cp, int which, 803 bool save_resolution_error, TRAPS); 804 static oop string_at_impl(constantPoolHandle this_cp, int which, int obj_index, TRAPS); 805 806 static void trace_class_resolution(constantPoolHandle this_cp, KlassHandle k); 807 808 // Resolve string constants (to prevent allocation during compilation) 809 static void resolve_string_constants_impl(constantPoolHandle this_cp, TRAPS); 810 811 static oop resolve_constant_at_impl(constantPoolHandle this_cp, int index, int cache_index, TRAPS); 812 static oop resolve_bootstrap_specifier_at_impl(constantPoolHandle this_cp, int index, TRAPS); 813 814 // Exception handling 815 static void throw_resolution_error(constantPoolHandle this_cp, int which, TRAPS); 816 static Symbol* exception_message(constantPoolHandle this_cp, int which, constantTag tag, oop pending_exception); 817 static void save_and_throw_exception(constantPoolHandle this_cp, int which, constantTag tag, TRAPS); 818 819 public: 820 // Merging ConstantPool* support: 821 bool compare_entry_to(int index1, constantPoolHandle cp2, int index2, TRAPS); 822 void copy_cp_to(int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS) { 823 constantPoolHandle h_this(THREAD, this); 824 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD); 825 } 826 static void copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS); 827 static void copy_entry_to(constantPoolHandle from_cp, int from_i, constantPoolHandle to_cp, int to_i, TRAPS); 828 static void copy_operands(constantPoolHandle from_cp, constantPoolHandle to_cp, TRAPS); 829 int find_matching_entry(int pattern_i, constantPoolHandle search_cp, TRAPS); 830 int version() const { return _saved._version; } 831 void set_version(int version) { _saved._version = version; } 832 void increment_and_save_version(int version) { 833 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow 834 } 835 836 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; } 837 int resolved_reference_length() const { return _saved._resolved_reference_length; } 838 839 // Decrease ref counts of symbols that are in the constant pool 840 // when the holder class is unloaded 841 void unreference_symbols(); 842 843 // Deallocate constant pool for RedefineClasses 844 void deallocate_contents(ClassLoaderData* loader_data); 845 void release_C_heap_structures(); 846 847 // JVMTI accesss - GetConstantPool, RetransformClasses, ... 848 friend class JvmtiConstantPoolReconstituter; 849 850 private: 851 jint cpool_entry_size(jint idx); 852 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap); 853 854 // Copy cpool bytes into byte array. 855 // Returns: 856 // int > 0, count of the raw cpool bytes that have been copied 857 // 0, OutOfMemory error 858 // -1, Internal error 859 int copy_cpool_bytes(int cpool_size, 860 SymbolHashMap* tbl, 861 unsigned char *bytes); 862 863 public: 864 // Verify 865 void verify_on(outputStream* st); 866 867 // Printing 868 void print_on(outputStream* st) const; 869 void print_value_on(outputStream* st) const; 870 void print_entry_on(int index, outputStream* st); 871 872 const char* internal_name() const { return "{constant pool}"; } 873 874#ifndef PRODUCT 875 // Compile the world support 876 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS); 877#endif 878}; 879 880class SymbolHashMapEntry : public CHeapObj<mtSymbol> { 881 private: 882 unsigned int _hash; // 32-bit hash for item 883 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket 884 Symbol* _symbol; // 1-st part of the mapping: symbol => value 885 u2 _value; // 2-nd part of the mapping: symbol => value 886 887 public: 888 unsigned int hash() const { return _hash; } 889 void set_hash(unsigned int hash) { _hash = hash; } 890 891 SymbolHashMapEntry* next() const { return _next; } 892 void set_next(SymbolHashMapEntry* next) { _next = next; } 893 894 Symbol* symbol() const { return _symbol; } 895 void set_symbol(Symbol* sym) { _symbol = sym; } 896 897 u2 value() const { return _value; } 898 void set_value(u2 value) { _value = value; } 899 900 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value) 901 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {} 902 903}; // End SymbolHashMapEntry class 904 905 906class SymbolHashMapBucket : public CHeapObj<mtSymbol> { 907 908private: 909 SymbolHashMapEntry* _entry; 910 911public: 912 SymbolHashMapEntry* entry() const { return _entry; } 913 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; } 914 void clear() { _entry = NULL; } 915 916}; // End SymbolHashMapBucket class 917 918 919class SymbolHashMap: public CHeapObj<mtSymbol> { 920 921 private: 922 // Default number of entries in the table 923 enum SymbolHashMap_Constants { 924 _Def_HashMap_Size = 256 925 }; 926 927 int _table_size; 928 SymbolHashMapBucket* _buckets; 929 930 void initialize_table(int table_size) { 931 _table_size = table_size; 932 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol); 933 for (int index = 0; index < table_size; index++) { 934 _buckets[index].clear(); 935 } 936 } 937 938 public: 939 940 int table_size() const { return _table_size; } 941 942 SymbolHashMap() { initialize_table(_Def_HashMap_Size); } 943 SymbolHashMap(int table_size) { initialize_table(table_size); } 944 945 // hash P(31) from Kernighan & Ritchie 946 static unsigned int compute_hash(const char* str, int len) { 947 unsigned int hash = 0; 948 while (len-- > 0) { 949 hash = 31*hash + (unsigned) *str; 950 str++; 951 } 952 return hash; 953 } 954 955 SymbolHashMapEntry* bucket(int i) { 956 return _buckets[i].entry(); 957 } 958 959 void add_entry(Symbol* sym, u2 value); 960 SymbolHashMapEntry* find_entry(Symbol* sym); 961 962 u2 symbol_to_value(Symbol* sym) { 963 SymbolHashMapEntry *entry = find_entry(sym); 964 return (entry == NULL) ? 0 : entry->value(); 965 } 966 967 ~SymbolHashMap() { 968 SymbolHashMapEntry* next; 969 for (int i = 0; i < _table_size; i++) { 970 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) { 971 next = cur->next(); 972 delete(cur); 973 } 974 } 975 delete _buckets; 976 } 977}; // End SymbolHashMap class 978 979#endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP 980