1 /* 2 * Copyright (c) 1997, 2023, 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 "cds/archiveHeapLoader.hpp" 27 #include "cds/cdsConfig.hpp" 28 #include "cds/heapShared.hpp" 29 #include "classfile/classLoaderData.inline.hpp" 30 #include "classfile/classLoaderDataGraph.inline.hpp" 31 #include "classfile/javaClasses.inline.hpp" 32 #include "classfile/moduleEntry.hpp" 33 #include "classfile/systemDictionary.hpp" 34 #include "classfile/systemDictionaryShared.hpp" 35 #include "classfile/vmClasses.hpp" 36 #include "classfile/vmSymbols.hpp" 37 #include "gc/shared/collectedHeap.inline.hpp" 38 #include "jvm_io.h" 39 #include "logging/log.hpp" 40 #include "memory/metadataFactory.hpp" 41 #include "memory/metaspaceClosure.hpp" 42 #include "memory/oopFactory.hpp" 43 #include "memory/resourceArea.hpp" 44 #include "memory/universe.hpp" 45 #include "oops/compressedOops.inline.hpp" 46 #include "oops/instanceKlass.hpp" 47 #include "oops/klass.inline.hpp" 48 #include "oops/objArrayKlass.hpp" 49 #include "oops/oop.inline.hpp" 50 #include "oops/oopHandle.inline.hpp" 51 #include "prims/jvmtiExport.hpp" 52 #include "runtime/atomic.hpp" 53 #include "runtime/handles.inline.hpp" 54 #include "utilities/macros.hpp" 55 #include "utilities/powerOfTwo.hpp" 56 #include "utilities/stack.inline.hpp" 57 58 void Klass::set_java_mirror(Handle m) { 59 assert(!m.is_null(), "New mirror should never be null."); 60 assert(_java_mirror.is_empty(), "should only be used to initialize mirror"); 61 _java_mirror = class_loader_data()->add_handle(m); 62 } 63 64 bool Klass::is_cloneable() const { 65 return _access_flags.is_cloneable_fast() || 66 is_subtype_of(vmClasses::Cloneable_klass()); 67 } 68 69 void Klass::set_is_cloneable() { 70 if (name() == vmSymbols::java_lang_invoke_MemberName()) { 71 assert(is_final(), "no subclasses allowed"); 72 // MemberName cloning should not be intrinsified and always happen in JVM_Clone. 73 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) { 74 // Reference cloning should not be intrinsified and always happen in JVM_Clone. 75 } else { 76 _access_flags.set_is_cloneable_fast(); 77 } 78 } 79 80 void Klass::set_name(Symbol* n) { 81 _name = n; 82 if (_name != nullptr) _name->increment_refcount(); 83 84 if (CDSConfig::is_dumping_archive() && is_instance_klass()) { 85 SystemDictionaryShared::init_dumptime_info(InstanceKlass::cast(this)); 86 } 87 } 88 89 bool Klass::is_subclass_of(const Klass* k) const { 90 // Run up the super chain and check 91 if (this == k) return true; 92 93 Klass* t = const_cast<Klass*>(this)->super(); 94 95 while (t != nullptr) { 96 if (t == k) return true; 97 t = t->super(); 98 } 99 return false; 100 } 101 102 void Klass::release_C_heap_structures(bool release_constant_pool) { 103 if (_name != nullptr) _name->decrement_refcount(); 104 } 105 106 bool Klass::search_secondary_supers(Klass* k) const { 107 // Put some extra logic here out-of-line, before the search proper. 108 // This cuts down the size of the inline method. 109 110 // This is necessary, since I am never in my own secondary_super list. 111 if (this == k) 112 return true; 113 // Scan the array-of-objects for a match 114 int cnt = secondary_supers()->length(); 115 for (int i = 0; i < cnt; i++) { 116 if (secondary_supers()->at(i) == k) { 117 ((Klass*)this)->set_secondary_super_cache(k); 118 return true; 119 } 120 } 121 return false; 122 } 123 124 // Return self, except for abstract classes with exactly 1 125 // implementor. Then return the 1 concrete implementation. 126 Klass *Klass::up_cast_abstract() { 127 Klass *r = this; 128 while( r->is_abstract() ) { // Receiver is abstract? 129 Klass *s = r->subklass(); // Check for exactly 1 subklass 130 if (s == nullptr || s->next_sibling() != nullptr) // Oops; wrong count; give up 131 return this; // Return 'this' as a no-progress flag 132 r = s; // Loop till find concrete class 133 } 134 return r; // Return the 1 concrete class 135 } 136 137 // Find LCA in class hierarchy 138 Klass *Klass::LCA( Klass *k2 ) { 139 Klass *k1 = this; 140 while( 1 ) { 141 if( k1->is_subtype_of(k2) ) return k2; 142 if( k2->is_subtype_of(k1) ) return k1; 143 k1 = k1->super(); 144 k2 = k2->super(); 145 } 146 } 147 148 149 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) { 150 ResourceMark rm(THREAD); 151 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError() 152 : vmSymbols::java_lang_InstantiationException(), external_name()); 153 } 154 155 156 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) { 157 ResourceMark rm(THREAD); 158 assert(s != nullptr, "Throw NPE!"); 159 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), 160 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name())); 161 } 162 163 164 void Klass::initialize(TRAPS) { 165 ShouldNotReachHere(); 166 } 167 168 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 169 #ifdef ASSERT 170 tty->print_cr("Error: find_field called on a klass oop." 171 " Likely error: reflection method does not correctly" 172 " wrap return value in a mirror object."); 173 #endif 174 ShouldNotReachHere(); 175 return nullptr; 176 } 177 178 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, 179 OverpassLookupMode overpass_mode, 180 PrivateLookupMode private_mode) const { 181 #ifdef ASSERT 182 tty->print_cr("Error: uncached_lookup_method called on a klass oop." 183 " Likely error: reflection method does not correctly" 184 " wrap return value in a mirror object."); 185 #endif 186 ShouldNotReachHere(); 187 return nullptr; 188 } 189 190 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() { 191 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD); 192 } 193 194 Klass::Klass() : _kind(UnknownKlassKind) { 195 assert(CDSConfig::is_dumping_static_archive() || UseSharedSpaces, "only for cds"); 196 } 197 198 // "Normal" instantiation is preceded by a MetaspaceObj allocation 199 // which zeros out memory - calloc equivalent. 200 // The constructor is also used from CppVtableCloner, 201 // which doesn't zero out the memory before calling the constructor. 202 Klass::Klass(KlassKind kind) : _kind(kind), 203 _shared_class_path_index(-1) { 204 CDS_ONLY(_shared_class_flags = 0;) 205 CDS_JAVA_HEAP_ONLY(_archived_mirror_index = -1;) 206 _primary_supers[0] = this; 207 set_super_check_offset(in_bytes(primary_supers_offset())); 208 } 209 210 jint Klass::array_layout_helper(BasicType etype) { 211 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype"); 212 // Note that T_ARRAY is not allowed here. 213 int hsize = arrayOopDesc::base_offset_in_bytes(etype); 214 int esize = type2aelembytes(etype); 215 bool isobj = (etype == T_OBJECT); 216 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value; 217 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize)); 218 219 assert(lh < (int)_lh_neutral_value, "must look like an array layout"); 220 assert(layout_helper_is_array(lh), "correct kind"); 221 assert(layout_helper_is_objArray(lh) == isobj, "correct kind"); 222 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind"); 223 assert(layout_helper_header_size(lh) == hsize, "correct decode"); 224 assert(layout_helper_element_type(lh) == etype, "correct decode"); 225 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode"); 226 227 return lh; 228 } 229 230 bool Klass::can_be_primary_super_slow() const { 231 if (super() == nullptr) 232 return true; 233 else if (super()->super_depth() >= primary_super_limit()-1) 234 return false; 235 else 236 return true; 237 } 238 239 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) { 240 if (k == nullptr) { 241 set_super(nullptr); 242 _primary_supers[0] = this; 243 assert(super_depth() == 0, "Object must already be initialized properly"); 244 } else if (k != super() || k == vmClasses::Object_klass()) { 245 assert(super() == nullptr || super() == vmClasses::Object_klass(), 246 "initialize this only once to a non-trivial value"); 247 set_super(k); 248 Klass* sup = k; 249 int sup_depth = sup->super_depth(); 250 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit()); 251 if (!can_be_primary_super_slow()) 252 my_depth = primary_super_limit(); 253 for (juint i = 0; i < my_depth; i++) { 254 _primary_supers[i] = sup->_primary_supers[i]; 255 } 256 Klass* *super_check_cell; 257 if (my_depth < primary_super_limit()) { 258 _primary_supers[my_depth] = this; 259 super_check_cell = &_primary_supers[my_depth]; 260 } else { 261 // Overflow of the primary_supers array forces me to be secondary. 262 super_check_cell = &_secondary_super_cache; 263 } 264 set_super_check_offset(u4((address)super_check_cell - (address) this)); 265 266 #ifdef ASSERT 267 { 268 juint j = super_depth(); 269 assert(j == my_depth, "computed accessor gets right answer"); 270 Klass* t = this; 271 while (!t->can_be_primary_super()) { 272 t = t->super(); 273 j = t->super_depth(); 274 } 275 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) { 276 assert(primary_super_of_depth(j1) == nullptr, "super list padding"); 277 } 278 while (t != nullptr) { 279 assert(primary_super_of_depth(j) == t, "super list initialization"); 280 t = t->super(); 281 --j; 282 } 283 assert(j == (juint)-1, "correct depth count"); 284 } 285 #endif 286 } 287 288 if (secondary_supers() == nullptr) { 289 290 // Now compute the list of secondary supertypes. 291 // Secondaries can occasionally be on the super chain, 292 // if the inline "_primary_supers" array overflows. 293 int extras = 0; 294 Klass* p; 295 for (p = super(); !(p == nullptr || p->can_be_primary_super()); p = p->super()) { 296 ++extras; 297 } 298 299 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below 300 301 // Compute the "real" non-extra secondaries. 302 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces); 303 if (secondaries == nullptr) { 304 // secondary_supers set by compute_secondary_supers 305 return; 306 } 307 308 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras); 309 310 for (p = super(); !(p == nullptr || p->can_be_primary_super()); p = p->super()) { 311 int i; // Scan for overflow primaries being duplicates of 2nd'arys 312 313 // This happens frequently for very deeply nested arrays: the 314 // primary superclass chain overflows into the secondary. The 315 // secondary list contains the element_klass's secondaries with 316 // an extra array dimension added. If the element_klass's 317 // secondary list already contains some primary overflows, they 318 // (with the extra level of array-ness) will collide with the 319 // normal primary superclass overflows. 320 for( i = 0; i < secondaries->length(); i++ ) { 321 if( secondaries->at(i) == p ) 322 break; 323 } 324 if( i < secondaries->length() ) 325 continue; // It's a dup, don't put it in 326 primaries->push(p); 327 } 328 // Combine the two arrays into a metadata object to pack the array. 329 // The primaries are added in the reverse order, then the secondaries. 330 int new_length = primaries->length() + secondaries->length(); 331 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>( 332 class_loader_data(), new_length, CHECK); 333 int fill_p = primaries->length(); 334 for (int j = 0; j < fill_p; j++) { 335 s2->at_put(j, primaries->pop()); // add primaries in reverse order. 336 } 337 for( int j = 0; j < secondaries->length(); j++ ) { 338 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end. 339 } 340 341 #ifdef ASSERT 342 // We must not copy any null placeholders left over from bootstrap. 343 for (int j = 0; j < s2->length(); j++) { 344 assert(s2->at(j) != nullptr, "correct bootstrapping order"); 345 } 346 #endif 347 348 set_secondary_supers(s2); 349 } 350 } 351 352 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots, 353 Array<InstanceKlass*>* transitive_interfaces) { 354 assert(num_extra_slots == 0, "override for complex klasses"); 355 assert(transitive_interfaces == nullptr, "sanity"); 356 set_secondary_supers(Universe::the_empty_klass_array()); 357 return nullptr; 358 } 359 360 361 // superklass links 362 InstanceKlass* Klass::superklass() const { 363 assert(super() == nullptr || super()->is_instance_klass(), "must be instance klass"); 364 return _super == nullptr ? nullptr : InstanceKlass::cast(_super); 365 } 366 367 // subklass links. Used by the compiler (and vtable initialization) 368 // May be cleaned concurrently, so must use the Compile_lock. 369 // The log parameter is for clean_weak_klass_links to report unlinked classes. 370 Klass* Klass::subklass(bool log) const { 371 // Need load_acquire on the _subklass, because it races with inserts that 372 // publishes freshly initialized data. 373 for (Klass* chain = Atomic::load_acquire(&_subklass); 374 chain != nullptr; 375 // Do not need load_acquire on _next_sibling, because inserts never 376 // create _next_sibling edges to dead data. 377 chain = Atomic::load(&chain->_next_sibling)) 378 { 379 if (chain->is_loader_alive()) { 380 return chain; 381 } else if (log) { 382 if (log_is_enabled(Trace, class, unload)) { 383 ResourceMark rm; 384 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name()); 385 } 386 } 387 } 388 return nullptr; 389 } 390 391 Klass* Klass::next_sibling(bool log) const { 392 // Do not need load_acquire on _next_sibling, because inserts never 393 // create _next_sibling edges to dead data. 394 for (Klass* chain = Atomic::load(&_next_sibling); 395 chain != nullptr; 396 chain = Atomic::load(&chain->_next_sibling)) { 397 // Only return alive klass, there may be stale klass 398 // in this chain if cleaned concurrently. 399 if (chain->is_loader_alive()) { 400 return chain; 401 } else if (log) { 402 if (log_is_enabled(Trace, class, unload)) { 403 ResourceMark rm; 404 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name()); 405 } 406 } 407 } 408 return nullptr; 409 } 410 411 void Klass::set_subklass(Klass* s) { 412 assert(s != this, "sanity check"); 413 Atomic::release_store(&_subklass, s); 414 } 415 416 void Klass::set_next_sibling(Klass* s) { 417 assert(s != this, "sanity check"); 418 // Does not need release semantics. If used by cleanup, it will link to 419 // already safely published data, and if used by inserts, will be published 420 // safely using cmpxchg. 421 Atomic::store(&_next_sibling, s); 422 } 423 424 void Klass::append_to_sibling_list() { 425 if (Universe::is_fully_initialized()) { 426 assert_locked_or_safepoint(Compile_lock); 427 } 428 debug_only(verify();) 429 // add ourselves to superklass' subklass list 430 InstanceKlass* super = superklass(); 431 if (super == nullptr) return; // special case: class Object 432 assert((!super->is_interface() // interfaces cannot be supers 433 && (super->superklass() == nullptr || !is_interface())), 434 "an interface can only be a subklass of Object"); 435 436 // Make sure there is no stale subklass head 437 super->clean_subklass(); 438 439 for (;;) { 440 Klass* prev_first_subklass = Atomic::load_acquire(&_super->_subklass); 441 if (prev_first_subklass != nullptr) { 442 // set our sibling to be the superklass' previous first subklass 443 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses"); 444 set_next_sibling(prev_first_subklass); 445 } 446 // Note that the prev_first_subklass is always alive, meaning no sibling_next links 447 // are ever created to not alive klasses. This is an important invariant of the lock-free 448 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list. 449 if (Atomic::cmpxchg(&super->_subklass, prev_first_subklass, this) == prev_first_subklass) { 450 return; 451 } 452 } 453 debug_only(verify();) 454 } 455 456 void Klass::clean_subklass() { 457 for (;;) { 458 // Need load_acquire, due to contending with concurrent inserts 459 Klass* subklass = Atomic::load_acquire(&_subklass); 460 if (subklass == nullptr || subklass->is_loader_alive()) { 461 return; 462 } 463 // Try to fix _subklass until it points at something not dead. 464 Atomic::cmpxchg(&_subklass, subklass, subklass->next_sibling()); 465 } 466 } 467 468 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) { 469 if (!ClassUnloading || !unloading_occurred) { 470 return; 471 } 472 473 Klass* root = vmClasses::Object_klass(); 474 Stack<Klass*, mtGC> stack; 475 476 stack.push(root); 477 while (!stack.is_empty()) { 478 Klass* current = stack.pop(); 479 480 assert(current->is_loader_alive(), "just checking, this should be live"); 481 482 // Find and set the first alive subklass 483 Klass* sub = current->subklass(true); 484 current->clean_subklass(); 485 if (sub != nullptr) { 486 stack.push(sub); 487 } 488 489 // Find and set the first alive sibling 490 Klass* sibling = current->next_sibling(true); 491 current->set_next_sibling(sibling); 492 if (sibling != nullptr) { 493 stack.push(sibling); 494 } 495 496 // Clean the implementors list and method data. 497 if (clean_alive_klasses && current->is_instance_klass()) { 498 InstanceKlass* ik = InstanceKlass::cast(current); 499 ik->clean_weak_instanceklass_links(); 500 501 // JVMTI RedefineClasses creates previous versions that are not in 502 // the class hierarchy, so process them here. 503 while ((ik = ik->previous_versions()) != nullptr) { 504 ik->clean_weak_instanceklass_links(); 505 } 506 } 507 } 508 } 509 510 void Klass::metaspace_pointers_do(MetaspaceClosure* it) { 511 if (log_is_enabled(Trace, cds)) { 512 ResourceMark rm; 513 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name()); 514 } 515 516 it->push(&_name); 517 it->push(&_secondary_super_cache); 518 it->push(&_secondary_supers); 519 for (int i = 0; i < _primary_super_limit; i++) { 520 it->push(&_primary_supers[i]); 521 } 522 it->push(&_super); 523 if (!CDSConfig::is_dumping_archive()) { 524 // If dumping archive, these may point to excluded classes. There's no need 525 // to follow these pointers anyway, as they will be set to null in 526 // remove_unshareable_info(). 527 it->push((Klass**)&_subklass); 528 it->push((Klass**)&_next_sibling); 529 it->push(&_next_link); 530 } 531 532 vtableEntry* vt = start_of_vtable(); 533 for (int i=0; i<vtable_length(); i++) { 534 it->push(vt[i].method_addr()); 535 } 536 } 537 538 #if INCLUDE_CDS 539 void Klass::remove_unshareable_info() { 540 assert(CDSConfig::is_dumping_archive(), 541 "only called during CDS dump time"); 542 JFR_ONLY(REMOVE_ID(this);) 543 if (log_is_enabled(Trace, cds, unshareable)) { 544 ResourceMark rm; 545 log_trace(cds, unshareable)("remove: %s", external_name()); 546 } 547 548 set_subklass(nullptr); 549 set_next_sibling(nullptr); 550 set_next_link(nullptr); 551 552 // Null out class_loader_data because we don't share that yet. 553 set_class_loader_data(nullptr); 554 set_is_shared(); 555 } 556 557 void Klass::remove_java_mirror() { 558 assert(CDSConfig::is_dumping_archive(), "sanity"); 559 if (log_is_enabled(Trace, cds, unshareable)) { 560 ResourceMark rm; 561 log_trace(cds, unshareable)("remove java_mirror: %s", external_name()); 562 } 563 // Just null out the mirror. The class_loader_data() no longer exists. 564 clear_java_mirror_handle(); 565 } 566 567 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 568 assert(is_klass(), "ensure C++ vtable is restored"); 569 assert(is_shared(), "must be set"); 570 JFR_ONLY(RESTORE_ID(this);) 571 if (log_is_enabled(Trace, cds, unshareable)) { 572 ResourceMark rm(THREAD); 573 oop class_loader = loader_data->class_loader(); 574 log_trace(cds, unshareable)("restore: %s with class loader: %s", external_name(), 575 class_loader != nullptr ? class_loader->klass()->external_name() : "boot"); 576 } 577 578 // If an exception happened during CDS restore, some of these fields may already be 579 // set. We leave the class on the CLD list, even if incomplete so that we don't 580 // modify the CLD list outside a safepoint. 581 if (class_loader_data() == nullptr) { 582 set_class_loader_data(loader_data); 583 584 // Add to class loader list first before creating the mirror 585 // (same order as class file parsing) 586 loader_data->add_class(this); 587 } 588 589 Handle loader(THREAD, loader_data->class_loader()); 590 ModuleEntry* module_entry = nullptr; 591 Klass* k = this; 592 if (k->is_objArray_klass()) { 593 k = ObjArrayKlass::cast(k)->bottom_klass(); 594 } 595 // Obtain klass' module. 596 if (k->is_instance_klass()) { 597 InstanceKlass* ik = (InstanceKlass*) k; 598 module_entry = ik->module(); 599 } else { 600 module_entry = ModuleEntryTable::javabase_moduleEntry(); 601 } 602 // Obtain java.lang.Module, if available 603 Handle module_handle(THREAD, ((module_entry != nullptr) ? module_entry->module() : (oop)nullptr)); 604 605 if (this->has_archived_mirror_index()) { 606 ResourceMark rm(THREAD); 607 log_debug(cds, mirror)("%s has raw archived mirror", external_name()); 608 if (ArchiveHeapLoader::is_in_use()) { 609 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle, 610 protection_domain, 611 CHECK); 612 if (present) { 613 return; 614 } 615 } 616 617 // No archived mirror data 618 log_debug(cds, mirror)("No archived mirror data for %s", external_name()); 619 clear_java_mirror_handle(); 620 this->clear_archived_mirror_index(); 621 } 622 623 // Only recreate it if not present. A previous attempt to restore may have 624 // gotten an OOM later but keep the mirror if it was created. 625 if (java_mirror() == nullptr) { 626 ResourceMark rm(THREAD); 627 log_trace(cds, mirror)("Recreate mirror for %s", external_name()); 628 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, Handle(), CHECK); 629 } 630 } 631 #endif // INCLUDE_CDS 632 633 #if INCLUDE_CDS_JAVA_HEAP 634 oop Klass::archived_java_mirror() { 635 assert(has_archived_mirror_index(), "must have archived mirror"); 636 return HeapShared::get_root(_archived_mirror_index); 637 } 638 639 void Klass::clear_archived_mirror_index() { 640 if (_archived_mirror_index >= 0) { 641 HeapShared::clear_root(_archived_mirror_index); 642 } 643 _archived_mirror_index = -1; 644 } 645 646 // No GC barrier 647 void Klass::set_archived_java_mirror(int mirror_index) { 648 assert(CDSConfig::is_dumping_heap(), "sanity"); 649 _archived_mirror_index = mirror_index; 650 } 651 #endif // INCLUDE_CDS_JAVA_HEAP 652 653 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) { 654 if (length > max_length) { 655 if (!THREAD->in_retryable_allocation()) { 656 report_java_out_of_memory("Requested array size exceeds VM limit"); 657 JvmtiExport::post_array_size_exhausted(); 658 THROW_OOP(Universe::out_of_memory_error_array_size()); 659 } else { 660 THROW_OOP(Universe::out_of_memory_error_retry()); 661 } 662 } else if (length < 0) { 663 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length)); 664 } 665 } 666 667 // Replace the last '+' char with '/'. 668 static char* convert_hidden_name_to_java(Symbol* name) { 669 size_t name_len = name->utf8_length(); 670 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1); 671 name->as_klass_external_name(result, (int)name_len + 1); 672 for (int index = (int)name_len; index > 0; index--) { 673 if (result[index] == '+') { 674 result[index] = JVM_SIGNATURE_SLASH; 675 break; 676 } 677 } 678 return result; 679 } 680 681 // In product mode, this function doesn't have virtual function calls so 682 // there might be some performance advantage to handling InstanceKlass here. 683 const char* Klass::external_name() const { 684 if (is_instance_klass()) { 685 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this); 686 if (ik->is_hidden()) { 687 char* result = convert_hidden_name_to_java(name()); 688 return result; 689 } 690 } else if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) { 691 char* result = convert_hidden_name_to_java(name()); 692 return result; 693 } 694 if (name() == nullptr) return "<unknown>"; 695 return name()->as_klass_external_name(); 696 } 697 698 const char* Klass::signature_name() const { 699 if (name() == nullptr) return "<unknown>"; 700 if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) { 701 size_t name_len = name()->utf8_length(); 702 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1); 703 name()->as_C_string(result, (int)name_len + 1); 704 for (int index = (int)name_len; index > 0; index--) { 705 if (result[index] == '+') { 706 result[index] = JVM_SIGNATURE_DOT; 707 break; 708 } 709 } 710 return result; 711 } 712 return name()->as_C_string(); 713 } 714 715 const char* Klass::external_kind() const { 716 if (is_interface()) return "interface"; 717 if (is_abstract()) return "abstract class"; 718 return "class"; 719 } 720 721 // Unless overridden, jvmti_class_status has no flags set. 722 jint Klass::jvmti_class_status() const { 723 return 0; 724 } 725 726 727 // Printing 728 729 void Klass::print_on(outputStream* st) const { 730 ResourceMark rm; 731 // print title 732 st->print("%s", internal_name()); 733 print_address_on(st); 734 st->cr(); 735 } 736 737 #define BULLET " - " 738 739 // Caller needs ResourceMark 740 void Klass::oop_print_on(oop obj, outputStream* st) { 741 // print title 742 st->print_cr("%s ", internal_name()); 743 obj->print_address_on(st); 744 745 if (WizardMode) { 746 // print header 747 obj->mark().print_on(st); 748 st->cr(); 749 } 750 751 // print class 752 st->print(BULLET"klass: "); 753 obj->klass()->print_value_on(st); 754 st->cr(); 755 } 756 757 void Klass::oop_print_value_on(oop obj, outputStream* st) { 758 // print title 759 ResourceMark rm; // Cannot print in debug mode without this 760 st->print("%s", internal_name()); 761 obj->print_address_on(st); 762 } 763 764 // Verification 765 766 void Klass::verify_on(outputStream* st) { 767 768 // This can be expensive, but it is worth checking that this klass is actually 769 // in the CLD graph but not in production. 770 assert(Metaspace::contains((address)this), "Should be"); 771 772 guarantee(this->is_klass(),"should be klass"); 773 774 if (super() != nullptr) { 775 guarantee(super()->is_klass(), "should be klass"); 776 } 777 if (secondary_super_cache() != nullptr) { 778 Klass* ko = secondary_super_cache(); 779 guarantee(ko->is_klass(), "should be klass"); 780 } 781 for ( uint i = 0; i < primary_super_limit(); i++ ) { 782 Klass* ko = _primary_supers[i]; 783 if (ko != nullptr) { 784 guarantee(ko->is_klass(), "should be klass"); 785 } 786 } 787 788 if (java_mirror_no_keepalive() != nullptr) { 789 guarantee(java_lang_Class::is_instance(java_mirror_no_keepalive()), "should be instance"); 790 } 791 } 792 793 void Klass::oop_verify_on(oop obj, outputStream* st) { 794 guarantee(oopDesc::is_oop(obj), "should be oop"); 795 guarantee(obj->klass()->is_klass(), "klass field is not a klass"); 796 } 797 798 bool Klass::is_valid(Klass* k) { 799 if (!is_aligned(k, sizeof(MetaWord))) return false; 800 if ((size_t)k < os::min_page_size()) return false; 801 802 if (!os::is_readable_range(k, k + 1)) return false; 803 if (!Metaspace::contains(k)) return false; 804 805 if (!Symbol::is_valid(k->name())) return false; 806 return ClassLoaderDataGraph::is_valid(k->class_loader_data()); 807 } 808 809 Method* Klass::method_at_vtable(int index) { 810 #ifndef PRODUCT 811 assert(index >= 0, "valid vtable index"); 812 if (DebugVtables) { 813 verify_vtable_index(index); 814 } 815 #endif 816 return start_of_vtable()[index].method(); 817 } 818 819 820 #ifndef PRODUCT 821 822 bool Klass::verify_vtable_index(int i) { 823 int limit = vtable_length()/vtableEntry::size(); 824 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit); 825 return true; 826 } 827 828 #endif // PRODUCT 829 830 // Caller needs ResourceMark 831 // joint_in_module_of_loader provides an optimization if 2 classes are in 832 // the same module to succinctly print out relevant information about their 833 // module name and class loader's name_and_id for error messages. 834 // Format: 835 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2> 836 // are in module <module-name>[@<version>] 837 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 838 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const { 839 assert(module() == class2->module(), "classes do not have the same module"); 840 const char* class1_name = external_name(); 841 size_t len = strlen(class1_name) + 1; 842 843 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader); 844 len += strlen(class2_description); 845 846 len += strlen(" and "); 847 848 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 849 850 // Just return the FQN if error when allocating string 851 if (joint_description == nullptr) { 852 return class1_name; 853 } 854 855 jio_snprintf(joint_description, len, "%s and %s", 856 class1_name, 857 class2_description); 858 859 return joint_description; 860 } 861 862 // Caller needs ResourceMark 863 // class_in_module_of_loader provides a standard way to include 864 // relevant information about a class, such as its module name as 865 // well as its class loader's name_and_id, in error messages and logging. 866 // Format: 867 // <fully-qualified-external-class-name> is in module <module-name>[@<version>] 868 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 869 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const { 870 // 1. fully qualified external name of class 871 const char* klass_name = external_name(); 872 size_t len = strlen(klass_name) + 1; 873 874 // 2. module name + @version 875 const char* module_name = ""; 876 const char* version = ""; 877 bool has_version = false; 878 bool module_is_named = false; 879 const char* module_name_phrase = ""; 880 const Klass* bottom_klass = is_objArray_klass() ? 881 ObjArrayKlass::cast(this)->bottom_klass() : this; 882 if (bottom_klass->is_instance_klass()) { 883 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module(); 884 if (module->is_named()) { 885 module_is_named = true; 886 module_name_phrase = "module "; 887 module_name = module->name()->as_C_string(); 888 len += strlen(module_name); 889 // Use version if exists and is not a jdk module 890 if (module->should_show_version()) { 891 has_version = true; 892 version = module->version()->as_C_string(); 893 // Include stlen(version) + 1 for the "@" 894 len += strlen(version) + 1; 895 } 896 } else { 897 module_name = UNNAMED_MODULE; 898 len += UNNAMED_MODULE_LEN; 899 } 900 } else { 901 // klass is an array of primitives, module is java.base 902 module_is_named = true; 903 module_name_phrase = "module "; 904 module_name = JAVA_BASE_NAME; 905 len += JAVA_BASE_NAME_LEN; 906 } 907 908 // 3. class loader's name_and_id 909 ClassLoaderData* cld = class_loader_data(); 910 assert(cld != nullptr, "class_loader_data should not be null"); 911 const char* loader_name_and_id = cld->loader_name_and_id(); 912 len += strlen(loader_name_and_id); 913 914 // 4. include parent loader information 915 const char* parent_loader_phrase = ""; 916 const char* parent_loader_name_and_id = ""; 917 if (include_parent_loader && 918 !cld->is_builtin_class_loader_data()) { 919 oop parent_loader = java_lang_ClassLoader::parent(class_loader()); 920 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data_or_null(parent_loader); 921 // The parent loader's ClassLoaderData could be null if it is 922 // a delegating class loader that has never defined a class. 923 // In this case the loader's name must be obtained via the parent loader's oop. 924 if (parent_cld == nullptr) { 925 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader); 926 if (cl_name_and_id != nullptr) { 927 parent_loader_name_and_id = java_lang_String::as_utf8_string(cl_name_and_id); 928 } 929 } else { 930 parent_loader_name_and_id = parent_cld->loader_name_and_id(); 931 } 932 parent_loader_phrase = ", parent loader "; 933 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id); 934 } 935 936 // Start to construct final full class description string 937 len += ((use_are) ? strlen(" are in ") : strlen(" is in ")); 938 len += strlen(module_name_phrase) + strlen(" of loader "); 939 940 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 941 942 // Just return the FQN if error when allocating string 943 if (class_description == nullptr) { 944 return klass_name; 945 } 946 947 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s", 948 klass_name, 949 (use_are) ? "are" : "is", 950 module_name_phrase, 951 module_name, 952 (has_version) ? "@" : "", 953 (has_version) ? version : "", 954 loader_name_and_id, 955 parent_loader_phrase, 956 parent_loader_name_and_id); 957 958 return class_description; 959 } --- EOF ---