1 /* 2 * Copyright (c) 1997, 2018, 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 "precompiled.hpp" 26 #include "classfile/classLoaderData.inline.hpp" 27 #include "classfile/classLoaderDataGraph.inline.hpp" 28 #include "classfile/dictionary.hpp" 29 #include "classfile/javaClasses.hpp" 30 #include "classfile/systemDictionary.hpp" 31 #include "classfile/vmSymbols.hpp" 32 #include "gc/shared/collectedHeap.inline.hpp" 33 #include "logging/log.hpp" 34 #include "memory/heapInspection.hpp" 35 #include "memory/metadataFactory.hpp" 36 #include "memory/metaspaceClosure.hpp" 37 #include "memory/metaspaceShared.hpp" 38 #include "memory/oopFactory.hpp" 39 #include "memory/resourceArea.hpp" 40 #include "oops/compressedOops.inline.hpp" 41 #include "oops/instanceKlass.hpp" 42 #include "oops/klass.inline.hpp" 43 #include "oops/oop.inline.hpp" 44 #include "oops/oopHandle.inline.hpp" 45 #include "runtime/atomic.hpp" 46 #include "runtime/handles.inline.hpp" 47 #include "runtime/orderAccess.hpp" 48 #include "utilities/macros.hpp" 49 #include "utilities/stack.inline.hpp" 50 51 void Klass::set_java_mirror(Handle m) { 52 assert(!m.is_null(), "New mirror should never be null."); 53 assert(_java_mirror.resolve() == NULL, "should only be used to initialize mirror"); 54 _java_mirror = class_loader_data()->add_handle(m); 55 } 56 57 oop Klass::java_mirror() const { 58 return _java_mirror.resolve(); 59 } 60 61 bool Klass::is_cloneable() const { 62 return _access_flags.is_cloneable_fast() || 63 is_subtype_of(SystemDictionary::Cloneable_klass()); 64 } 65 66 void Klass::set_is_cloneable() { 67 if (name() == vmSymbols::java_lang_invoke_MemberName()) { 68 assert(is_final(), "no subclasses allowed"); 69 // MemberName cloning should not be intrinsified and always happen in JVM_Clone. 70 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) { 71 // Reference cloning should not be intrinsified and always happen in JVM_Clone. 72 } else { 73 _access_flags.set_is_cloneable_fast(); 74 } 75 } 76 77 void Klass::set_name(Symbol* n) { 78 _name = n; 79 if (_name != NULL) _name->increment_refcount(); 80 } 81 82 bool Klass::is_subclass_of(const Klass* k) const { 83 // Run up the super chain and check 84 if (this == k) return true; 85 86 Klass* t = const_cast<Klass*>(this)->super(); 87 88 while (t != NULL) { 89 if (t == k) return true; 90 t = t->super(); 91 } 92 return false; 93 } 94 95 bool Klass::search_secondary_supers(Klass* k) const { 96 // Put some extra logic here out-of-line, before the search proper. 97 // This cuts down the size of the inline method. 98 99 // This is necessary, since I am never in my own secondary_super list. 100 if (this == k) 101 return true; 102 // Scan the array-of-objects for a match 103 int cnt = secondary_supers()->length(); 104 for (int i = 0; i < cnt; i++) { 105 if (secondary_supers()->at(i) == k) { 106 ((Klass*)this)->set_secondary_super_cache(k); 107 return true; 108 } 109 } 110 return false; 111 } 112 113 // Return self, except for abstract classes with exactly 1 114 // implementor. Then return the 1 concrete implementation. 115 Klass *Klass::up_cast_abstract() { 116 Klass *r = this; 117 while( r->is_abstract() ) { // Receiver is abstract? 118 Klass *s = r->subklass(); // Check for exactly 1 subklass 119 if( !s || s->next_sibling() ) // Oops; wrong count; give up 120 return this; // Return 'this' as a no-progress flag 121 r = s; // Loop till find concrete class 122 } 123 return r; // Return the 1 concrete class 124 } 125 126 // Find LCA in class hierarchy 127 Klass *Klass::LCA( Klass *k2 ) { 128 Klass *k1 = this; 129 while( 1 ) { 130 if( k1->is_subtype_of(k2) ) return k2; 131 if( k2->is_subtype_of(k1) ) return k1; 132 k1 = k1->super(); 133 k2 = k2->super(); 134 } 135 } 136 137 138 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) { 139 ResourceMark rm(THREAD); 140 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError() 141 : vmSymbols::java_lang_InstantiationException(), external_name()); 142 } 143 144 145 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) { 146 ResourceMark rm(THREAD); 147 assert(s != NULL, "Throw NPE!"); 148 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), 149 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name())); 150 } 151 152 153 void Klass::initialize(TRAPS) { 154 ShouldNotReachHere(); 155 } 156 157 bool Klass::compute_is_subtype_of(Klass* k) { 158 assert(k->is_klass(), "argument must be a class"); 159 return is_subclass_of(k); 160 } 161 162 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 163 #ifdef ASSERT 164 tty->print_cr("Error: find_field called on a klass oop." 165 " Likely error: reflection method does not correctly" 166 " wrap return value in a mirror object."); 167 #endif 168 ShouldNotReachHere(); 169 return NULL; 170 } 171 172 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, 173 OverpassLookupMode overpass_mode, 174 PrivateLookupMode private_mode) const { 175 #ifdef ASSERT 176 tty->print_cr("Error: uncached_lookup_method called on a klass oop." 177 " Likely error: reflection method does not correctly" 178 " wrap return value in a mirror object."); 179 #endif 180 ShouldNotReachHere(); 181 return NULL; 182 } 183 184 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() { 185 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD); 186 } 187 188 // "Normal" instantiation is preceeded by a MetaspaceObj allocation 189 // which zeros out memory - calloc equivalent. 190 // The constructor is also used from CppVtableCloner, 191 // which doesn't zero out the memory before calling the constructor. 192 // Need to set the _java_mirror field explicitly to not hit an assert that the field 193 // should be NULL before setting it. 194 Klass::Klass(KlassID id) : _id(id), 195 _java_mirror(NULL), 196 _prototype_header(markOopDesc::prototype()), 197 _shared_class_path_index(-1) { 198 CDS_ONLY(_shared_class_flags = 0;) 199 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;) 200 _primary_supers[0] = this; 201 set_super_check_offset(in_bytes(primary_supers_offset())); 202 } 203 204 jint Klass::array_layout_helper(BasicType etype) { 205 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype"); 206 // Note that T_ARRAY is not allowed here. 207 int hsize = arrayOopDesc::base_offset_in_bytes(etype); 208 int esize = type2aelembytes(etype); 209 bool isobj = (etype == T_OBJECT); 210 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value; 211 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize)); 212 213 assert(lh < (int)_lh_neutral_value, "must look like an array layout"); 214 assert(layout_helper_is_array(lh), "correct kind"); 215 assert(layout_helper_is_objArray(lh) == isobj, "correct kind"); 216 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind"); 217 assert(layout_helper_header_size(lh) == hsize, "correct decode"); 218 assert(layout_helper_element_type(lh) == etype, "correct decode"); 219 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode"); 220 221 return lh; 222 } 223 224 bool Klass::can_be_primary_super_slow() const { 225 if (super() == NULL) 226 return true; 227 else if (super()->super_depth() >= primary_super_limit()-1) 228 return false; 229 else 230 return true; 231 } 232 233 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) { 234 if (FastSuperclassLimit == 0) { 235 // None of the other machinery matters. 236 set_super(k); 237 return; 238 } 239 if (k == NULL) { 240 set_super(NULL); 241 _primary_supers[0] = this; 242 assert(super_depth() == 0, "Object must already be initialized properly"); 243 } else if (k != super() || k == SystemDictionary::Object_klass()) { 244 assert(super() == NULL || super() == SystemDictionary::Object_klass(), 245 "initialize this only once to a non-trivial value"); 246 set_super(k); 247 Klass* sup = k; 248 int sup_depth = sup->super_depth(); 249 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit()); 250 if (!can_be_primary_super_slow()) 251 my_depth = primary_super_limit(); 252 for (juint i = 0; i < my_depth; i++) { 253 _primary_supers[i] = sup->_primary_supers[i]; 254 } 255 Klass* *super_check_cell; 256 if (my_depth < primary_super_limit()) { 257 _primary_supers[my_depth] = this; 258 super_check_cell = &_primary_supers[my_depth]; 259 } else { 260 // Overflow of the primary_supers array forces me to be secondary. 261 super_check_cell = &_secondary_super_cache; 262 } 263 set_super_check_offset((address)super_check_cell - (address) this); 264 265 #ifdef ASSERT 266 { 267 juint j = super_depth(); 268 assert(j == my_depth, "computed accessor gets right answer"); 269 Klass* t = this; 270 while (!t->can_be_primary_super()) { 271 t = t->super(); 272 j = t->super_depth(); 273 } 274 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) { 275 assert(primary_super_of_depth(j1) == NULL, "super list padding"); 276 } 277 while (t != NULL) { 278 assert(primary_super_of_depth(j) == t, "super list initialization"); 279 t = t->super(); 280 --j; 281 } 282 assert(j == (juint)-1, "correct depth count"); 283 } 284 #endif 285 } 286 287 if (secondary_supers() == NULL) { 288 289 // Now compute the list of secondary supertypes. 290 // Secondaries can occasionally be on the super chain, 291 // if the inline "_primary_supers" array overflows. 292 int extras = 0; 293 Klass* p; 294 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 295 ++extras; 296 } 297 298 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below 299 300 // Compute the "real" non-extra secondaries. 301 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces); 302 if (secondaries == NULL) { 303 // secondary_supers set by compute_secondary_supers 304 return; 305 } 306 307 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras); 308 309 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 310 int i; // Scan for overflow primaries being duplicates of 2nd'arys 311 312 // This happens frequently for very deeply nested arrays: the 313 // primary superclass chain overflows into the secondary. The 314 // secondary list contains the element_klass's secondaries with 315 // an extra array dimension added. If the element_klass's 316 // secondary list already contains some primary overflows, they 317 // (with the extra level of array-ness) will collide with the 318 // normal primary superclass overflows. 319 for( i = 0; i < secondaries->length(); i++ ) { 320 if( secondaries->at(i) == p ) 321 break; 322 } 323 if( i < secondaries->length() ) 324 continue; // It's a dup, don't put it in 325 primaries->push(p); 326 } 327 // Combine the two arrays into a metadata object to pack the array. 328 // The primaries are added in the reverse order, then the secondaries. 329 int new_length = primaries->length() + secondaries->length(); 330 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>( 331 class_loader_data(), new_length, CHECK); 332 int fill_p = primaries->length(); 333 for (int j = 0; j < fill_p; j++) { 334 s2->at_put(j, primaries->pop()); // add primaries in reverse order. 335 } 336 for( int j = 0; j < secondaries->length(); j++ ) { 337 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end. 338 } 339 340 #ifdef ASSERT 341 // We must not copy any NULL placeholders left over from bootstrap. 342 for (int j = 0; j < s2->length(); j++) { 343 assert(s2->at(j) != NULL, "correct bootstrapping order"); 344 } 345 #endif 346 347 set_secondary_supers(s2); 348 } 349 } 350 351 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots, 352 Array<InstanceKlass*>* transitive_interfaces) { 353 assert(num_extra_slots == 0, "override for complex klasses"); 354 assert(transitive_interfaces == NULL, "sanity"); 355 set_secondary_supers(Universe::the_empty_klass_array()); 356 return NULL; 357 } 358 359 360 InstanceKlass* Klass::superklass() const { 361 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass"); 362 return _super == NULL ? NULL : InstanceKlass::cast(_super); 363 } 364 365 void Klass::set_subklass(Klass* s) { 366 assert(s != this, "sanity check"); 367 _subklass = s; 368 } 369 370 void Klass::set_next_sibling(Klass* s) { 371 assert(s != this, "sanity check"); 372 _next_sibling = s; 373 } 374 375 void Klass::append_to_sibling_list() { 376 debug_only(verify();) 377 // add ourselves to superklass' subklass list 378 InstanceKlass* super = superklass(); 379 if (super == NULL) return; // special case: class Object 380 assert((!super->is_interface() // interfaces cannot be supers 381 && (super->superklass() == NULL || !is_interface())), 382 "an interface can only be a subklass of Object"); 383 Klass* prev_first_subklass = super->subklass(); 384 if (prev_first_subklass != NULL) { 385 // set our sibling to be the superklass' previous first subklass 386 set_next_sibling(prev_first_subklass); 387 } 388 // make ourselves the superklass' first subklass 389 super->set_subklass(this); 390 debug_only(verify();) 391 } 392 393 oop Klass::holder_phantom() const { 394 return class_loader_data()->holder_phantom(); 395 } 396 397 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) { 398 if (!ClassUnloading || !unloading_occurred) { 399 return; 400 } 401 402 Klass* root = SystemDictionary::Object_klass(); 403 Stack<Klass*, mtGC> stack; 404 405 stack.push(root); 406 while (!stack.is_empty()) { 407 Klass* current = stack.pop(); 408 409 assert(current->is_loader_alive(), "just checking, this should be live"); 410 411 // Find and set the first alive subklass 412 Klass* sub = current->subklass(); 413 while (sub != NULL && !sub->is_loader_alive()) { 414 #ifndef PRODUCT 415 if (log_is_enabled(Trace, class, unload)) { 416 ResourceMark rm; 417 log_trace(class, unload)("unlinking class (subclass): %s", sub->external_name()); 418 } 419 #endif 420 sub = sub->next_sibling(); 421 } 422 current->set_subklass(sub); 423 if (sub != NULL) { 424 stack.push(sub); 425 } 426 427 // Find and set the first alive sibling 428 Klass* sibling = current->next_sibling(); 429 while (sibling != NULL && !sibling->is_loader_alive()) { 430 if (log_is_enabled(Trace, class, unload)) { 431 ResourceMark rm; 432 log_trace(class, unload)("[Unlinking class (sibling) %s]", sibling->external_name()); 433 } 434 sibling = sibling->next_sibling(); 435 } 436 current->set_next_sibling(sibling); 437 if (sibling != NULL) { 438 stack.push(sibling); 439 } 440 441 // Clean the implementors list and method data. 442 if (clean_alive_klasses && current->is_instance_klass()) { 443 InstanceKlass* ik = InstanceKlass::cast(current); 444 ik->clean_weak_instanceklass_links(); 445 446 // JVMTI RedefineClasses creates previous versions that are not in 447 // the class hierarchy, so process them here. 448 while ((ik = ik->previous_versions()) != NULL) { 449 ik->clean_weak_instanceklass_links(); 450 } 451 } 452 } 453 } 454 455 void Klass::metaspace_pointers_do(MetaspaceClosure* it) { 456 if (log_is_enabled(Trace, cds)) { 457 ResourceMark rm; 458 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name()); 459 } 460 461 it->push(&_name); 462 it->push(&_secondary_super_cache); 463 it->push(&_secondary_supers); 464 for (int i = 0; i < _primary_super_limit; i++) { 465 it->push(&_primary_supers[i]); 466 } 467 it->push(&_super); 468 it->push(&_subklass); 469 it->push(&_next_sibling); 470 it->push(&_next_link); 471 472 vtableEntry* vt = start_of_vtable(); 473 for (int i=0; i<vtable_length(); i++) { 474 it->push(vt[i].method_addr()); 475 } 476 } 477 478 void Klass::remove_unshareable_info() { 479 assert (DumpSharedSpaces, "only called for DumpSharedSpaces"); 480 JFR_ONLY(REMOVE_ID(this);) 481 if (log_is_enabled(Trace, cds, unshareable)) { 482 ResourceMark rm; 483 log_trace(cds, unshareable)("remove: %s", external_name()); 484 } 485 486 set_subklass(NULL); 487 set_next_sibling(NULL); 488 set_next_link(NULL); 489 490 // Null out class_loader_data because we don't share that yet. 491 set_class_loader_data(NULL); 492 set_is_shared(); 493 } 494 495 void Klass::remove_java_mirror() { 496 assert (DumpSharedSpaces, "only called for DumpSharedSpaces"); 497 if (log_is_enabled(Trace, cds, unshareable)) { 498 ResourceMark rm; 499 log_trace(cds, unshareable)("remove java_mirror: %s", external_name()); 500 } 501 // Just null out the mirror. The class_loader_data() no longer exists. 502 _java_mirror = NULL; 503 } 504 505 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 506 assert(is_klass(), "ensure C++ vtable is restored"); 507 assert(is_shared(), "must be set"); 508 JFR_ONLY(RESTORE_ID(this);) 509 if (log_is_enabled(Trace, cds, unshareable)) { 510 ResourceMark rm; 511 log_trace(cds, unshareable)("restore: %s", external_name()); 512 } 513 514 // If an exception happened during CDS restore, some of these fields may already be 515 // set. We leave the class on the CLD list, even if incomplete so that we don't 516 // modify the CLD list outside a safepoint. 517 if (class_loader_data() == NULL) { 518 // Restore class_loader_data to the null class loader data 519 set_class_loader_data(loader_data); 520 521 // Add to null class loader list first before creating the mirror 522 // (same order as class file parsing) 523 loader_data->add_class(this); 524 } 525 526 Handle loader(THREAD, loader_data->class_loader()); 527 ModuleEntry* module_entry = NULL; 528 Klass* k = this; 529 if (k->is_objArray_klass()) { 530 k = ObjArrayKlass::cast(k)->bottom_klass(); 531 } 532 // Obtain klass' module. 533 if (k->is_instance_klass()) { 534 InstanceKlass* ik = (InstanceKlass*) k; 535 module_entry = ik->module(); 536 } else { 537 module_entry = ModuleEntryTable::javabase_moduleEntry(); 538 } 539 // Obtain java.lang.Module, if available 540 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL)); 541 542 if (this->has_raw_archived_mirror()) { 543 ResourceMark rm; 544 log_debug(cds, mirror)("%s has raw archived mirror", external_name()); 545 if (MetaspaceShared::open_archive_heap_region_mapped()) { 546 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle, 547 protection_domain, 548 CHECK); 549 if (present) { 550 return; 551 } 552 } 553 554 // No archived mirror data 555 log_debug(cds, mirror)("No archived mirror data for %s", external_name()); 556 _java_mirror = NULL; 557 this->clear_has_raw_archived_mirror(); 558 } 559 560 // Only recreate it if not present. A previous attempt to restore may have 561 // gotten an OOM later but keep the mirror if it was created. 562 if (java_mirror() == NULL) { 563 log_trace(cds, mirror)("Recreate mirror for %s", external_name()); 564 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK); 565 } 566 } 567 568 #if INCLUDE_CDS_JAVA_HEAP 569 // Used at CDS dump time to access the archived mirror. No GC barrier. 570 oop Klass::archived_java_mirror_raw() { 571 assert(has_raw_archived_mirror(), "must have raw archived mirror"); 572 return CompressedOops::decode(_archived_mirror); 573 } 574 575 narrowOop Klass::archived_java_mirror_raw_narrow() { 576 assert(has_raw_archived_mirror(), "must have raw archived mirror"); 577 return _archived_mirror; 578 } 579 580 // No GC barrier 581 void Klass::set_archived_java_mirror_raw(oop m) { 582 assert(DumpSharedSpaces, "called only during runtime"); 583 _archived_mirror = CompressedOops::encode(m); 584 } 585 #endif // INCLUDE_CDS_JAVA_HEAP 586 587 Klass* Klass::array_klass_or_null(int rank) { 588 EXCEPTION_MARK; 589 // No exception can be thrown by array_klass_impl when called with or_null == true. 590 // (In anycase, the execption mark will fail if it do so) 591 return array_klass_impl(true, rank, THREAD); 592 } 593 594 595 Klass* Klass::array_klass_or_null() { 596 EXCEPTION_MARK; 597 // No exception can be thrown by array_klass_impl when called with or_null == true. 598 // (In anycase, the execption mark will fail if it do so) 599 return array_klass_impl(true, THREAD); 600 } 601 602 603 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) { 604 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass"); 605 return NULL; 606 } 607 608 609 Klass* Klass::array_klass_impl(bool or_null, TRAPS) { 610 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass"); 611 return NULL; 612 } 613 614 oop Klass::class_loader() const { return class_loader_data()->class_loader(); } 615 616 // In product mode, this function doesn't have virtual function calls so 617 // there might be some performance advantage to handling InstanceKlass here. 618 const char* Klass::external_name() const { 619 if (is_instance_klass()) { 620 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this); 621 if (ik->is_unsafe_anonymous()) { 622 char addr_buf[20]; 623 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik)); 624 size_t addr_len = strlen(addr_buf); 625 size_t name_len = name()->utf8_length(); 626 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1); 627 name()->as_klass_external_name(result, (int) name_len + 1); 628 assert(strlen(result) == name_len, ""); 629 strcpy(result + name_len, addr_buf); 630 assert(strlen(result) == name_len + addr_len, ""); 631 return result; 632 } 633 } 634 if (name() == NULL) return "<unknown>"; 635 return name()->as_klass_external_name(); 636 } 637 638 const char* Klass::signature_name() const { 639 if (name() == NULL) return "<unknown>"; 640 return name()->as_C_string(); 641 } 642 643 const char* Klass::external_kind() const { 644 if (is_interface()) return "interface"; 645 if (is_abstract()) return "abstract class"; 646 return "class"; 647 } 648 649 // Unless overridden, modifier_flags is 0. 650 jint Klass::compute_modifier_flags(TRAPS) const { 651 return 0; 652 } 653 654 int Klass::atomic_incr_biased_lock_revocation_count() { 655 return (int) Atomic::add(1, &_biased_lock_revocation_count); 656 } 657 658 // Unless overridden, jvmti_class_status has no flags set. 659 jint Klass::jvmti_class_status() const { 660 return 0; 661 } 662 663 664 // Printing 665 666 void Klass::print_on(outputStream* st) const { 667 ResourceMark rm; 668 // print title 669 st->print("%s", internal_name()); 670 print_address_on(st); 671 st->cr(); 672 } 673 674 void Klass::oop_print_on(oop obj, outputStream* st) { 675 ResourceMark rm; 676 // print title 677 st->print_cr("%s ", internal_name()); 678 obj->print_address_on(st); 679 680 if (WizardMode) { 681 // print header 682 obj->mark()->print_on(st); 683 } 684 685 // print class 686 st->print(" - klass: "); 687 obj->klass()->print_value_on(st); 688 st->cr(); 689 } 690 691 void Klass::oop_print_value_on(oop obj, outputStream* st) { 692 // print title 693 ResourceMark rm; // Cannot print in debug mode without this 694 st->print("%s", internal_name()); 695 obj->print_address_on(st); 696 } 697 698 #if INCLUDE_SERVICES 699 // Size Statistics 700 void Klass::collect_statistics(KlassSizeStats *sz) const { 701 sz->_klass_bytes = sz->count(this); 702 sz->_mirror_bytes = sz->count(java_mirror()); 703 sz->_secondary_supers_bytes = sz->count_array(secondary_supers()); 704 705 sz->_ro_bytes += sz->_secondary_supers_bytes; 706 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes; 707 } 708 #endif // INCLUDE_SERVICES 709 710 // Verification 711 712 void Klass::verify_on(outputStream* st) { 713 714 // This can be expensive, but it is worth checking that this klass is actually 715 // in the CLD graph but not in production. 716 assert(Metaspace::contains((address)this), "Should be"); 717 718 guarantee(this->is_klass(),"should be klass"); 719 720 if (super() != NULL) { 721 guarantee(super()->is_klass(), "should be klass"); 722 } 723 if (secondary_super_cache() != NULL) { 724 Klass* ko = secondary_super_cache(); 725 guarantee(ko->is_klass(), "should be klass"); 726 } 727 for ( uint i = 0; i < primary_super_limit(); i++ ) { 728 Klass* ko = _primary_supers[i]; 729 if (ko != NULL) { 730 guarantee(ko->is_klass(), "should be klass"); 731 } 732 } 733 734 if (java_mirror() != NULL) { 735 guarantee(oopDesc::is_oop(java_mirror()), "should be instance"); 736 } 737 } 738 739 void Klass::oop_verify_on(oop obj, outputStream* st) { 740 guarantee(oopDesc::is_oop(obj), "should be oop"); 741 guarantee(obj->klass()->is_klass(), "klass field is not a klass"); 742 } 743 744 Klass* Klass::decode_klass_raw(narrowKlass narrow_klass) { 745 return (Klass*)(void*)( (uintptr_t)Universe::narrow_klass_base() + 746 ((uintptr_t)narrow_klass << Universe::narrow_klass_shift())); 747 } 748 749 bool Klass::is_valid(Klass* k) { 750 if (!is_aligned(k, sizeof(MetaWord))) return false; 751 if ((size_t)k < os::min_page_size()) return false; 752 753 if (!os::is_readable_range(k, k + 1)) return false; 754 if (!MetaspaceUtils::is_range_in_committed(k, k + 1)) return false; 755 756 if (!Symbol::is_valid(k->name())) return false; 757 return ClassLoaderDataGraph::is_valid(k->class_loader_data()); 758 } 759 760 klassVtable Klass::vtable() const { 761 return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size()); 762 } 763 764 vtableEntry* Klass::start_of_vtable() const { 765 return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset())); 766 } 767 768 Method* Klass::method_at_vtable(int index) { 769 #ifndef PRODUCT 770 assert(index >= 0, "valid vtable index"); 771 if (DebugVtables) { 772 verify_vtable_index(index); 773 } 774 #endif 775 return start_of_vtable()[index].method(); 776 } 777 778 ByteSize Klass::vtable_start_offset() { 779 return in_ByteSize(InstanceKlass::header_size() * wordSize); 780 } 781 782 #ifndef PRODUCT 783 784 bool Klass::verify_vtable_index(int i) { 785 int limit = vtable_length()/vtableEntry::size(); 786 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit); 787 return true; 788 } 789 790 #endif // PRODUCT 791 792 // Caller needs ResourceMark 793 // joint_in_module_of_loader provides an optimization if 2 classes are in 794 // the same module to succinctly print out relevant information about their 795 // module name and class loader's name_and_id for error messages. 796 // Format: 797 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2> 798 // are in module <module-name>[@<version>] 799 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 800 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const { 801 assert(module() == class2->module(), "classes do not have the same module"); 802 const char* class1_name = external_name(); 803 size_t len = strlen(class1_name) + 1; 804 805 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader); 806 len += strlen(class2_description); 807 808 len += strlen(" and "); 809 810 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 811 812 // Just return the FQN if error when allocating string 813 if (joint_description == NULL) { 814 return class1_name; 815 } 816 817 jio_snprintf(joint_description, len, "%s and %s", 818 class1_name, 819 class2_description); 820 821 return joint_description; 822 } 823 824 // Caller needs ResourceMark 825 // class_in_module_of_loader provides a standard way to include 826 // relevant information about a class, such as its module name as 827 // well as its class loader's name_and_id, in error messages and logging. 828 // Format: 829 // <fully-qualified-external-class-name> is in module <module-name>[@<version>] 830 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 831 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const { 832 // 1. fully qualified external name of class 833 const char* klass_name = external_name(); 834 size_t len = strlen(klass_name) + 1; 835 836 // 2. module name + @version 837 const char* module_name = ""; 838 const char* version = ""; 839 bool has_version = false; 840 bool module_is_named = false; 841 const char* module_name_phrase = ""; 842 const Klass* bottom_klass = is_objArray_klass() ? 843 ObjArrayKlass::cast(this)->bottom_klass() : this; 844 if (bottom_klass->is_instance_klass()) { 845 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module(); 846 if (module->is_named()) { 847 module_is_named = true; 848 module_name_phrase = "module "; 849 module_name = module->name()->as_C_string(); 850 len += strlen(module_name); 851 // Use version if exists and is not a jdk module 852 if (module->should_show_version()) { 853 has_version = true; 854 version = module->version()->as_C_string(); 855 // Include stlen(version) + 1 for the "@" 856 len += strlen(version) + 1; 857 } 858 } else { 859 module_name = UNNAMED_MODULE; 860 len += UNNAMED_MODULE_LEN; 861 } 862 } else { 863 // klass is an array of primitives, module is java.base 864 module_is_named = true; 865 module_name_phrase = "module "; 866 module_name = JAVA_BASE_NAME; 867 len += JAVA_BASE_NAME_LEN; 868 } 869 870 // 3. class loader's name_and_id 871 ClassLoaderData* cld = class_loader_data(); 872 assert(cld != NULL, "class_loader_data should not be null"); 873 const char* loader_name_and_id = cld->loader_name_and_id(); 874 len += strlen(loader_name_and_id); 875 876 // 4. include parent loader information 877 const char* parent_loader_phrase = ""; 878 const char* parent_loader_name_and_id = ""; 879 if (include_parent_loader && 880 !cld->is_builtin_class_loader_data()) { 881 oop parent_loader = java_lang_ClassLoader::parent(class_loader()); 882 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data(parent_loader); 883 assert(parent_cld != NULL, "parent's class loader data should not be null"); 884 parent_loader_name_and_id = parent_cld->loader_name_and_id(); 885 parent_loader_phrase = ", parent loader "; 886 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id); 887 } 888 889 // Start to construct final full class description string 890 len += ((use_are) ? strlen(" are in ") : strlen(" is in ")); 891 len += strlen(module_name_phrase) + strlen(" of loader "); 892 893 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 894 895 // Just return the FQN if error when allocating string 896 if (class_description == NULL) { 897 return klass_name; 898 } 899 900 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s", 901 klass_name, 902 (use_are) ? "are" : "is", 903 module_name_phrase, 904 module_name, 905 (has_version) ? "@" : "", 906 (has_version) ? version : "", 907 loader_name_and_id, 908 parent_loader_phrase, 909 parent_loader_name_and_id); 910 911 return class_description; 912 }