1 /* 2 * Copyright (c) 1999, 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 #include "incls/_precompiled.incl" 26 #include "incls/_ciInstanceKlass.cpp.incl" 27 28 // ciInstanceKlass 29 // 30 // This class represents a klassOop in the HotSpot virtual machine 31 // whose Klass part in an instanceKlass. 32 33 // ------------------------------------------------------------------ 34 // ciInstanceKlass::ciInstanceKlass 35 // 36 // Loaded instance klass. 37 ciInstanceKlass::ciInstanceKlass(KlassHandle h_k) : 38 ciKlass(h_k), _non_static_fields(NULL) 39 { 40 assert(get_Klass()->oop_is_instance(), "wrong type"); 41 instanceKlass* ik = get_instanceKlass(); 42 43 AccessFlags access_flags = ik->access_flags(); 44 _flags = ciFlags(access_flags); 45 _has_finalizer = access_flags.has_finalizer(); 46 _has_subklass = ik->subklass() != NULL; 47 _init_state = (instanceKlass::ClassState)ik->get_init_state(); 48 _nonstatic_field_size = ik->nonstatic_field_size(); 49 _has_nonstatic_fields = ik->has_nonstatic_fields(); 50 _nonstatic_fields = NULL; // initialized lazily by compute_nonstatic_fields: 51 52 _nof_implementors = ik->nof_implementors(); 53 for (int i = 0; i < implementors_limit; i++) { 54 _implementors[i] = NULL; // we will fill these lazily 55 } 56 57 Thread *thread = Thread::current(); 58 if (ciObjectFactory::is_initialized()) { 59 _loader = JNIHandles::make_local(thread, ik->class_loader()); 60 _protection_domain = JNIHandles::make_local(thread, 61 ik->protection_domain()); 62 _is_shared = false; 63 } else { 64 Handle h_loader(thread, ik->class_loader()); 65 Handle h_protection_domain(thread, ik->protection_domain()); 66 _loader = JNIHandles::make_global(h_loader); 67 _protection_domain = JNIHandles::make_global(h_protection_domain); 68 _is_shared = true; 69 } 70 71 // Lazy fields get filled in only upon request. 72 _super = NULL; 73 _java_mirror = NULL; 74 75 if (is_shared()) { 76 if (h_k() != SystemDictionary::Object_klass()) { 77 super(); 78 } 79 java_mirror(); 80 //compute_nonstatic_fields(); // done outside of constructor 81 } 82 83 _field_cache = NULL; 84 } 85 86 // Version for unloaded classes: 87 ciInstanceKlass::ciInstanceKlass(ciSymbol* name, 88 jobject loader, jobject protection_domain) 89 : ciKlass(name, ciInstanceKlassKlass::make()) 90 { 91 assert(name->byte_at(0) != '[', "not an instance klass"); 92 _init_state = (instanceKlass::ClassState)0; 93 _nonstatic_field_size = -1; 94 _has_nonstatic_fields = false; 95 _nonstatic_fields = NULL; 96 _nof_implementors = -1; 97 _loader = loader; 98 _protection_domain = protection_domain; 99 _is_shared = false; 100 _super = NULL; 101 _java_mirror = NULL; 102 _field_cache = NULL; 103 } 104 105 106 107 // ------------------------------------------------------------------ 108 // ciInstanceKlass::compute_shared_is_initialized 109 void ciInstanceKlass::compute_shared_init_state() { 110 GUARDED_VM_ENTRY( 111 instanceKlass* ik = get_instanceKlass(); 112 _init_state = (instanceKlass::ClassState)ik->get_init_state(); 113 ) 114 } 115 116 // ------------------------------------------------------------------ 117 // ciInstanceKlass::compute_shared_has_subklass 118 bool ciInstanceKlass::compute_shared_has_subklass() { 119 GUARDED_VM_ENTRY( 120 instanceKlass* ik = get_instanceKlass(); 121 _has_subklass = ik->subklass() != NULL; 122 return _has_subklass; 123 ) 124 } 125 126 // ------------------------------------------------------------------ 127 // ciInstanceKlass::compute_shared_nof_implementors 128 int ciInstanceKlass::compute_shared_nof_implementors() { 129 // We requery this property, since it is a very old ciObject. 130 GUARDED_VM_ENTRY( 131 instanceKlass* ik = get_instanceKlass(); 132 _nof_implementors = ik->nof_implementors(); 133 return _nof_implementors; 134 ) 135 } 136 137 // ------------------------------------------------------------------ 138 // ciInstanceKlass::loader 139 oop ciInstanceKlass::loader() { 140 ASSERT_IN_VM; 141 return JNIHandles::resolve(_loader); 142 } 143 144 // ------------------------------------------------------------------ 145 // ciInstanceKlass::loader_handle 146 jobject ciInstanceKlass::loader_handle() { 147 return _loader; 148 } 149 150 // ------------------------------------------------------------------ 151 // ciInstanceKlass::protection_domain 152 oop ciInstanceKlass::protection_domain() { 153 ASSERT_IN_VM; 154 return JNIHandles::resolve(_protection_domain); 155 } 156 157 // ------------------------------------------------------------------ 158 // ciInstanceKlass::protection_domain_handle 159 jobject ciInstanceKlass::protection_domain_handle() { 160 return _protection_domain; 161 } 162 163 // ------------------------------------------------------------------ 164 // ciInstanceKlass::field_cache 165 // 166 // Get the field cache associated with this klass. 167 ciConstantPoolCache* ciInstanceKlass::field_cache() { 168 if (is_shared()) { 169 return NULL; 170 } 171 if (_field_cache == NULL) { 172 assert(!is_java_lang_Object(), "Object has no fields"); 173 Arena* arena = CURRENT_ENV->arena(); 174 _field_cache = new (arena) ciConstantPoolCache(arena, 5); 175 } 176 return _field_cache; 177 } 178 179 // ------------------------------------------------------------------ 180 // ciInstanceKlass::get_canonical_holder 181 // 182 ciInstanceKlass* ciInstanceKlass::get_canonical_holder(int offset) { 183 #ifdef ASSERT 184 if (!(offset >= 0 && offset < layout_helper())) { 185 tty->print("*** get_canonical_holder(%d) on ", offset); 186 this->print(); 187 tty->print_cr(" ***"); 188 }; 189 assert(offset >= 0 && offset < layout_helper(), "offset must be tame"); 190 #endif 191 192 if (offset < instanceOopDesc::base_offset_in_bytes()) { 193 // All header offsets belong properly to java/lang/Object. 194 return CURRENT_ENV->Object_klass(); 195 } 196 197 ciInstanceKlass* self = this; 198 for (;;) { 199 assert(self->is_loaded(), "must be loaded to have size"); 200 ciInstanceKlass* super = self->super(); 201 if (super == NULL || super->nof_nonstatic_fields() == 0 || 202 !super->contains_field_offset(offset)) { 203 return self; 204 } else { 205 self = super; // return super->get_canonical_holder(offset) 206 } 207 } 208 } 209 210 // ------------------------------------------------------------------ 211 // ciInstanceKlass::is_java_lang_Object 212 // 213 // Is this klass java.lang.Object? 214 bool ciInstanceKlass::is_java_lang_Object() { 215 return equals(CURRENT_ENV->Object_klass()); 216 } 217 218 // ------------------------------------------------------------------ 219 // ciInstanceKlass::uses_default_loader 220 bool ciInstanceKlass::uses_default_loader() { 221 // Note: We do not need to resolve the handle or enter the VM 222 // in order to test null-ness. 223 return _loader == NULL; 224 } 225 226 // ------------------------------------------------------------------ 227 // ciInstanceKlass::is_in_package 228 // 229 // Is this klass in the given package? 230 bool ciInstanceKlass::is_in_package(const char* packagename, int len) { 231 // To avoid class loader mischief, this test always rejects application classes. 232 if (!uses_default_loader()) 233 return false; 234 GUARDED_VM_ENTRY( 235 return is_in_package_impl(packagename, len); 236 ) 237 } 238 239 bool ciInstanceKlass::is_in_package_impl(const char* packagename, int len) { 240 ASSERT_IN_VM; 241 242 // If packagename contains trailing '/' exclude it from the 243 // prefix-test since we test for it explicitly. 244 if (packagename[len - 1] == '/') 245 len--; 246 247 if (!name()->starts_with(packagename, len)) 248 return false; 249 250 // Test if the class name is something like "java/lang". 251 if ((len + 1) > name()->utf8_length()) 252 return false; 253 254 // Test for trailing '/' 255 if ((char) name()->byte_at(len) != '/') 256 return false; 257 258 // Make sure it's not actually in a subpackage: 259 if (name()->index_of_at(len+1, "/", 1) >= 0) 260 return false; 261 262 return true; 263 } 264 265 // ------------------------------------------------------------------ 266 // ciInstanceKlass::print_impl 267 // 268 // Implementation of the print method. 269 void ciInstanceKlass::print_impl(outputStream* st) { 270 ciKlass::print_impl(st); 271 GUARDED_VM_ENTRY(st->print(" loader=0x%x", (address)loader());) 272 if (is_loaded()) { 273 st->print(" loaded=true initialized=%s finalized=%s subklass=%s size=%d flags=", 274 bool_to_str(is_initialized()), 275 bool_to_str(has_finalizer()), 276 bool_to_str(has_subklass()), 277 layout_helper()); 278 279 _flags.print_klass_flags(); 280 281 if (_super) { 282 st->print(" super="); 283 _super->print_name(); 284 } 285 if (_java_mirror) { 286 st->print(" mirror=PRESENT"); 287 } 288 } else { 289 st->print(" loaded=false"); 290 } 291 } 292 293 // ------------------------------------------------------------------ 294 // ciInstanceKlass::super 295 // 296 // Get the superklass of this klass. 297 ciInstanceKlass* ciInstanceKlass::super() { 298 assert(is_loaded(), "must be loaded"); 299 if (_super == NULL && !is_java_lang_Object()) { 300 GUARDED_VM_ENTRY( 301 klassOop super_klass = get_instanceKlass()->super(); 302 _super = CURRENT_ENV->get_object(super_klass)->as_instance_klass(); 303 ) 304 } 305 return _super; 306 } 307 308 // ------------------------------------------------------------------ 309 // ciInstanceKlass::java_mirror 310 // 311 // Get the instance of java.lang.Class corresponding to this klass. 312 // Cache it on this->_java_mirror. 313 ciInstance* ciInstanceKlass::java_mirror() { 314 if (_java_mirror == NULL) { 315 _java_mirror = ciKlass::java_mirror(); 316 } 317 return _java_mirror; 318 } 319 320 // ------------------------------------------------------------------ 321 // ciInstanceKlass::unique_concrete_subklass 322 ciInstanceKlass* ciInstanceKlass::unique_concrete_subklass() { 323 if (!is_loaded()) return NULL; // No change if class is not loaded 324 if (!is_abstract()) return NULL; // Only applies to abstract classes. 325 if (!has_subklass()) return NULL; // Must have at least one subklass. 326 VM_ENTRY_MARK; 327 instanceKlass* ik = get_instanceKlass(); 328 Klass* up = ik->up_cast_abstract(); 329 assert(up->oop_is_instance(), "must be instanceKlass"); 330 if (ik == up) { 331 return NULL; 332 } 333 return CURRENT_THREAD_ENV->get_object(up->as_klassOop())->as_instance_klass(); 334 } 335 336 // ------------------------------------------------------------------ 337 // ciInstanceKlass::has_finalizable_subclass 338 bool ciInstanceKlass::has_finalizable_subclass() { 339 if (!is_loaded()) return true; 340 VM_ENTRY_MARK; 341 return Dependencies::find_finalizable_subclass(get_instanceKlass()) != NULL; 342 } 343 344 // ------------------------------------------------------------------ 345 // ciInstanceKlass::get_field_by_offset 346 ciField* ciInstanceKlass::get_field_by_offset(int field_offset, bool is_static) { 347 if (!is_static) { 348 for (int i = 0, len = nof_nonstatic_fields(); i < len; i++) { 349 ciField* field = _nonstatic_fields->at(i); 350 int field_off = field->offset_in_bytes(); 351 if (field_off == field_offset) 352 return field; 353 if (field_off > field_offset) 354 break; 355 // could do binary search or check bins, but probably not worth it 356 } 357 return NULL; 358 } 359 VM_ENTRY_MARK; 360 instanceKlass* k = get_instanceKlass(); 361 fieldDescriptor fd; 362 if (!k->find_field_from_offset(field_offset, is_static, &fd)) { 363 return NULL; 364 } 365 ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd); 366 return field; 367 } 368 369 // ------------------------------------------------------------------ 370 // ciInstanceKlass::get_field_by_name 371 ciField* ciInstanceKlass::get_field_by_name(ciSymbol* name, ciSymbol* signature, bool is_static) { 372 VM_ENTRY_MARK; 373 instanceKlass* k = get_instanceKlass(); 374 fieldDescriptor fd; 375 klassOop def = k->find_field(name->get_symbolOop(), signature->get_symbolOop(), is_static, &fd); 376 if (def == NULL) { 377 return NULL; 378 } 379 ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd); 380 return field; 381 } 382 383 // ------------------------------------------------------------------ 384 // ciInstanceKlass::non_static_fields. 385 386 class NonStaticFieldFiller: public FieldClosure { 387 GrowableArray<ciField*>* _arr; 388 ciEnv* _curEnv; 389 public: 390 NonStaticFieldFiller(ciEnv* curEnv, GrowableArray<ciField*>* arr) : 391 _curEnv(curEnv), _arr(arr) 392 {} 393 void do_field(fieldDescriptor* fd) { 394 ciField* field = new (_curEnv->arena()) ciField(fd); 395 _arr->append(field); 396 } 397 }; 398 399 GrowableArray<ciField*>* ciInstanceKlass::non_static_fields() { 400 if (_non_static_fields == NULL) { 401 VM_ENTRY_MARK; 402 ciEnv* curEnv = ciEnv::current(); 403 instanceKlass* ik = get_instanceKlass(); 404 int max_n_fields = ik->fields()->length()/instanceKlass::next_offset; 405 406 Arena* arena = curEnv->arena(); 407 _non_static_fields = 408 new (arena) GrowableArray<ciField*>(arena, max_n_fields, 0, NULL); 409 NonStaticFieldFiller filler(curEnv, _non_static_fields); 410 ik->do_nonstatic_fields(&filler); 411 } 412 return _non_static_fields; 413 } 414 415 static int sort_field_by_offset(ciField** a, ciField** b) { 416 return (*a)->offset_in_bytes() - (*b)->offset_in_bytes(); 417 // (no worries about 32-bit overflow...) 418 } 419 420 // ------------------------------------------------------------------ 421 // ciInstanceKlass::compute_nonstatic_fields 422 int ciInstanceKlass::compute_nonstatic_fields() { 423 assert(is_loaded(), "must be loaded"); 424 425 if (_nonstatic_fields != NULL) 426 return _nonstatic_fields->length(); 427 428 if (!has_nonstatic_fields()) { 429 Arena* arena = CURRENT_ENV->arena(); 430 _nonstatic_fields = new (arena) GrowableArray<ciField*>(arena, 0, 0, NULL); 431 return 0; 432 } 433 assert(!is_java_lang_Object(), "bootstrap OK"); 434 435 // Size in bytes of my fields, including inherited fields. 436 int fsize = nonstatic_field_size() * heapOopSize; 437 438 ciInstanceKlass* super = this->super(); 439 GrowableArray<ciField*>* super_fields = NULL; 440 if (super != NULL && super->has_nonstatic_fields()) { 441 int super_fsize = super->nonstatic_field_size() * heapOopSize; 442 int super_flen = super->nof_nonstatic_fields(); 443 super_fields = super->_nonstatic_fields; 444 assert(super_flen == 0 || super_fields != NULL, "first get nof_fields"); 445 // See if I am no larger than my super; if so, I can use his fields. 446 if (fsize == super_fsize) { 447 _nonstatic_fields = super_fields; 448 return super_fields->length(); 449 } 450 } 451 452 GrowableArray<ciField*>* fields = NULL; 453 GUARDED_VM_ENTRY({ 454 fields = compute_nonstatic_fields_impl(super_fields); 455 }); 456 457 if (fields == NULL) { 458 // This can happen if this class (java.lang.Class) has invisible fields. 459 _nonstatic_fields = super_fields; 460 return super_fields->length(); 461 } 462 463 int flen = fields->length(); 464 465 // Now sort them by offset, ascending. 466 // (In principle, they could mix with superclass fields.) 467 fields->sort(sort_field_by_offset); 468 #ifdef ASSERT 469 int last_offset = instanceOopDesc::base_offset_in_bytes(); 470 for (int i = 0; i < fields->length(); i++) { 471 ciField* field = fields->at(i); 472 int offset = field->offset_in_bytes(); 473 int size = (field->_type == NULL) ? heapOopSize : field->size_in_bytes(); 474 assert(last_offset <= offset, err_msg("no field overlap: %d <= %d", last_offset, offset)); 475 if (last_offset > (int)sizeof(oopDesc)) 476 assert((offset - last_offset) < BytesPerLong, "no big holes"); 477 // Note: Two consecutive T_BYTE fields will be separated by wordSize-1 478 // padding bytes if one of them is declared by a superclass. 479 // This is a minor inefficiency classFileParser.cpp. 480 last_offset = offset + size; 481 } 482 assert(last_offset <= (int)instanceOopDesc::base_offset_in_bytes() + fsize, "no overflow"); 483 #endif 484 485 _nonstatic_fields = fields; 486 return flen; 487 } 488 489 GrowableArray<ciField*>* 490 ciInstanceKlass::compute_nonstatic_fields_impl(GrowableArray<ciField*>* 491 super_fields) { 492 ASSERT_IN_VM; 493 Arena* arena = CURRENT_ENV->arena(); 494 int flen = 0; 495 GrowableArray<ciField*>* fields = NULL; 496 instanceKlass* k = get_instanceKlass(); 497 typeArrayOop fields_array = k->fields(); 498 for (int pass = 0; pass <= 1; pass++) { 499 for (int i = 0, alen = fields_array->length(); i < alen; i += instanceKlass::next_offset) { 500 fieldDescriptor fd; 501 fd.initialize(k->as_klassOop(), i); 502 if (fd.is_static()) continue; 503 if (pass == 0) { 504 flen += 1; 505 } else { 506 ciField* field = new (arena) ciField(&fd); 507 fields->append(field); 508 } 509 } 510 511 // Between passes, allocate the array: 512 if (pass == 0) { 513 if (flen == 0) { 514 return NULL; // return nothing if none are locally declared 515 } 516 if (super_fields != NULL) { 517 flen += super_fields->length(); 518 } 519 fields = new (arena) GrowableArray<ciField*>(arena, flen, 0, NULL); 520 if (super_fields != NULL) { 521 fields->appendAll(super_fields); 522 } 523 } 524 } 525 assert(fields->length() == flen, "sanity"); 526 return fields; 527 } 528 529 // ------------------------------------------------------------------ 530 // ciInstanceKlass::find_method 531 // 532 // Find a method in this klass. 533 ciMethod* ciInstanceKlass::find_method(ciSymbol* name, ciSymbol* signature) { 534 VM_ENTRY_MARK; 535 instanceKlass* k = get_instanceKlass(); 536 symbolOop name_sym = name->get_symbolOop(); 537 symbolOop sig_sym= signature->get_symbolOop(); 538 539 methodOop m = k->find_method(name_sym, sig_sym); 540 if (m == NULL) return NULL; 541 542 return CURRENT_THREAD_ENV->get_object(m)->as_method(); 543 } 544 545 // ------------------------------------------------------------------ 546 // ciInstanceKlass::is_leaf_type 547 bool ciInstanceKlass::is_leaf_type() { 548 assert(is_loaded(), "must be loaded"); 549 if (is_shared()) { 550 return is_final(); // approximately correct 551 } else { 552 return !_has_subklass && (_nof_implementors == 0); 553 } 554 } 555 556 // ------------------------------------------------------------------ 557 // ciInstanceKlass::implementor 558 // 559 // Report an implementor of this interface. 560 // Returns NULL if exact information is not available. 561 // Note that there are various races here, since my copy 562 // of _nof_implementors might be out of date with respect 563 // to results returned by instanceKlass::implementor. 564 // This is OK, since any dependencies we decide to assert 565 // will be checked later under the Compile_lock. 566 ciInstanceKlass* ciInstanceKlass::implementor(int n) { 567 if (n >= implementors_limit) { 568 return NULL; 569 } 570 ciInstanceKlass* impl = _implementors[n]; 571 if (impl == NULL) { 572 if (_nof_implementors > implementors_limit) { 573 return NULL; 574 } 575 // Go into the VM to fetch the implementor. 576 { 577 VM_ENTRY_MARK; 578 klassOop k = get_instanceKlass()->implementor(n); 579 if (k != NULL) { 580 impl = CURRENT_THREAD_ENV->get_object(k)->as_instance_klass(); 581 } 582 } 583 // Memoize this result. 584 if (!is_shared()) { 585 _implementors[n] = (impl == NULL)? this: impl; 586 } 587 } else if (impl == this) { 588 impl = NULL; // memoized null result from a VM query 589 } 590 return impl; 591 }