1 /* 2 * Copyright (c) 1997, 2022, 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/heapShared.hpp" 28 #include "classfile/classLoaderData.inline.hpp" 29 #include "classfile/classLoaderDataGraph.inline.hpp" 30 #include "classfile/javaClasses.inline.hpp" 31 #include "classfile/moduleEntry.hpp" 32 #include "classfile/systemDictionary.hpp" 33 #include "classfile/systemDictionaryShared.hpp" 34 #include "classfile/vmClasses.hpp" 35 #include "classfile/vmSymbols.hpp" 36 #include "gc/shared/collectedHeap.inline.hpp" 37 #include "jvm_io.h" 38 #include "logging/log.hpp" 39 #include "memory/metadataFactory.hpp" 40 #include "memory/metaspaceClosure.hpp" 41 #include "memory/oopFactory.hpp" 42 #include "memory/resourceArea.hpp" 43 #include "memory/universe.hpp" 44 #include "oops/compressedOops.inline.hpp" 45 #include "oops/instanceKlass.hpp" 46 #include "oops/klass.inline.hpp" 47 #include "oops/objArrayKlass.hpp" 48 #include "oops/oop.inline.hpp" 49 #include "oops/oopHandle.inline.hpp" 50 #include "prims/jvmtiExport.hpp" 51 #include "runtime/arguments.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 oop Klass::java_mirror_no_keepalive() const { 65 return _java_mirror.peek(); 66 } 67 68 bool Klass::is_cloneable() const { 69 return _access_flags.is_cloneable_fast() || 70 is_subtype_of(vmClasses::Cloneable_klass()); 71 } 72 73 void Klass::set_is_cloneable() { 74 if (name() == vmSymbols::java_lang_invoke_MemberName()) { 75 assert(is_final(), "no subclasses allowed"); 76 // MemberName cloning should not be intrinsified and always happen in JVM_Clone. 77 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) { 78 // Reference cloning should not be intrinsified and always happen in JVM_Clone. 79 } else { 80 _access_flags.set_is_cloneable_fast(); 81 } 82 } 83 84 void Klass::set_name(Symbol* n) { 85 _name = n; 86 if (_name != NULL) _name->increment_refcount(); 87 88 if (Arguments::is_dumping_archive() && is_instance_klass()) { 89 SystemDictionaryShared::init_dumptime_info(InstanceKlass::cast(this)); 90 } 91 } 92 93 bool Klass::is_subclass_of(const Klass* k) const { 94 // Run up the super chain and check 95 if (this == k) return true; 96 97 Klass* t = const_cast<Klass*>(this)->super(); 98 99 while (t != NULL) { 100 if (t == k) return true; 101 t = t->super(); 102 } 103 return false; 104 } 105 106 void Klass::release_C_heap_structures(bool release_constant_pool) { 107 if (_name != NULL) _name->decrement_refcount(); 108 } 109 110 bool Klass::search_secondary_supers(Klass* k) const { 111 // Put some extra logic here out-of-line, before the search proper. 112 // This cuts down the size of the inline method. 113 114 // This is necessary, since I am never in my own secondary_super list. 115 if (this == k) 116 return true; 117 // Scan the array-of-objects for a match 118 int cnt = secondary_supers()->length(); 119 for (int i = 0; i < cnt; i++) { 120 if (secondary_supers()->at(i) == k) { 121 ((Klass*)this)->set_secondary_super_cache(k); 122 return true; 123 } 124 } 125 return false; 126 } 127 128 // Return self, except for abstract classes with exactly 1 129 // implementor. Then return the 1 concrete implementation. 130 Klass *Klass::up_cast_abstract() { 131 Klass *r = this; 132 while( r->is_abstract() ) { // Receiver is abstract? 133 Klass *s = r->subklass(); // Check for exactly 1 subklass 134 if (s == NULL || s->next_sibling() != NULL) // Oops; wrong count; give up 135 return this; // Return 'this' as a no-progress flag 136 r = s; // Loop till find concrete class 137 } 138 return r; // Return the 1 concrete class 139 } 140 141 // Find LCA in class hierarchy 142 Klass *Klass::LCA( Klass *k2 ) { 143 Klass *k1 = this; 144 while( 1 ) { 145 if( k1->is_subtype_of(k2) ) return k2; 146 if( k2->is_subtype_of(k1) ) return k1; 147 k1 = k1->super(); 148 k2 = k2->super(); 149 } 150 } 151 152 153 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) { 154 ResourceMark rm(THREAD); 155 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError() 156 : vmSymbols::java_lang_InstantiationException(), external_name()); 157 } 158 159 160 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) { 161 ResourceMark rm(THREAD); 162 assert(s != NULL, "Throw NPE!"); 163 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), 164 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name())); 165 } 166 167 168 void Klass::initialize(TRAPS) { 169 ShouldNotReachHere(); 170 } 171 172 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 173 #ifdef ASSERT 174 tty->print_cr("Error: find_field called on a klass oop." 175 " Likely error: reflection method does not correctly" 176 " wrap return value in a mirror object."); 177 #endif 178 ShouldNotReachHere(); 179 return NULL; 180 } 181 182 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, 183 OverpassLookupMode overpass_mode, 184 PrivateLookupMode private_mode) const { 185 #ifdef ASSERT 186 tty->print_cr("Error: uncached_lookup_method called on a klass oop." 187 " Likely error: reflection method does not correctly" 188 " wrap return value in a mirror object."); 189 #endif 190 ShouldNotReachHere(); 191 return NULL; 192 } 193 194 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() { 195 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD); 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 _prototype_header(markWord::prototype()), 204 _shared_class_path_index(-1) { 205 CDS_ONLY(_shared_class_flags = 0;) 206 CDS_JAVA_HEAP_ONLY(_archived_mirror_index = -1;) 207 _primary_supers[0] = this; 208 set_super_check_offset(in_bytes(primary_supers_offset())); 209 } 210 211 jint Klass::array_layout_helper(BasicType etype) { 212 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype"); 213 // Note that T_ARRAY is not allowed here. 214 int hsize = arrayOopDesc::base_offset_in_bytes(etype); 215 int esize = type2aelembytes(etype); 216 bool isobj = (etype == T_OBJECT); 217 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value; 218 int lh = array_layout_helper(tag, false, hsize, etype, exact_log2(esize)); 219 220 assert(lh < (int)_lh_neutral_value, "must look like an array layout"); 221 assert(layout_helper_is_array(lh), "correct kind"); 222 assert(layout_helper_is_objArray(lh) == isobj, "correct kind"); 223 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind"); 224 assert(layout_helper_header_size(lh) == hsize, "correct decode"); 225 assert(layout_helper_element_type(lh) == etype, "correct decode"); 226 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode"); 227 228 return lh; 229 } 230 231 bool Klass::can_be_primary_super_slow() const { 232 if (super() == NULL) 233 return true; 234 else if (super()->super_depth() >= primary_super_limit()-1) 235 return false; 236 else 237 return true; 238 } 239 240 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) { 241 if (k == NULL) { 242 set_super(NULL); 243 _primary_supers[0] = this; 244 assert(super_depth() == 0, "Object must already be initialized properly"); 245 } else if (k != super() || k == vmClasses::Object_klass()) { 246 assert(super() == NULL || super() == vmClasses::Object_klass(), 247 "initialize this only once to a non-trivial value"); 248 set_super(k); 249 Klass* sup = k; 250 int sup_depth = sup->super_depth(); 251 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit()); 252 if (!can_be_primary_super_slow()) 253 my_depth = primary_super_limit(); 254 for (juint i = 0; i < my_depth; i++) { 255 _primary_supers[i] = sup->_primary_supers[i]; 256 } 257 Klass* *super_check_cell; 258 if (my_depth < primary_super_limit()) { 259 _primary_supers[my_depth] = this; 260 super_check_cell = &_primary_supers[my_depth]; 261 } else { 262 // Overflow of the primary_supers array forces me to be secondary. 263 super_check_cell = &_secondary_super_cache; 264 } 265 set_super_check_offset((address)super_check_cell - (address) this); 266 267 #ifdef ASSERT 268 { 269 juint j = super_depth(); 270 assert(j == my_depth, "computed accessor gets right answer"); 271 Klass* t = this; 272 while (!t->can_be_primary_super()) { 273 t = t->super(); 274 j = t->super_depth(); 275 } 276 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) { 277 assert(primary_super_of_depth(j1) == NULL, "super list padding"); 278 } 279 while (t != NULL) { 280 assert(primary_super_of_depth(j) == t, "super list initialization"); 281 t = t->super(); 282 --j; 283 } 284 assert(j == (juint)-1, "correct depth count"); 285 } 286 #endif 287 } 288 289 if (secondary_supers() == NULL) { 290 291 // Now compute the list of secondary supertypes. 292 // Secondaries can occasionally be on the super chain, 293 // if the inline "_primary_supers" array overflows. 294 int extras = 0; 295 Klass* p; 296 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 297 ++extras; 298 } 299 300 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below 301 302 // Compute the "real" non-extra secondaries. 303 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces); 304 if (secondaries == NULL) { 305 // secondary_supers set by compute_secondary_supers 306 return; 307 } 308 309 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras); 310 311 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 312 int i; // Scan for overflow primaries being duplicates of 2nd'arys 313 314 // This happens frequently for very deeply nested arrays: the 315 // primary superclass chain overflows into the secondary. The 316 // secondary list contains the element_klass's secondaries with 317 // an extra array dimension added. If the element_klass's 318 // secondary list already contains some primary overflows, they 319 // (with the extra level of array-ness) will collide with the 320 // normal primary superclass overflows. 321 for( i = 0; i < secondaries->length(); i++ ) { 322 if( secondaries->at(i) == p ) 323 break; 324 } 325 if( i < secondaries->length() ) 326 continue; // It's a dup, don't put it in 327 primaries->push(p); 328 } 329 // Combine the two arrays into a metadata object to pack the array. 330 // The primaries are added in the reverse order, then the secondaries. 331 int new_length = primaries->length() + secondaries->length(); 332 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>( 333 class_loader_data(), new_length, CHECK); 334 int fill_p = primaries->length(); 335 for (int j = 0; j < fill_p; j++) { 336 s2->at_put(j, primaries->pop()); // add primaries in reverse order. 337 } 338 for( int j = 0; j < secondaries->length(); j++ ) { 339 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end. 340 } 341 342 #ifdef ASSERT 343 // We must not copy any NULL placeholders left over from bootstrap. 344 for (int j = 0; j < s2->length(); j++) { 345 assert(s2->at(j) != NULL, "correct bootstrapping order"); 346 } 347 #endif 348 349 set_secondary_supers(s2); 350 } 351 } 352 353 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots, 354 Array<InstanceKlass*>* transitive_interfaces) { 355 assert(num_extra_slots == 0, "override for complex klasses"); 356 assert(transitive_interfaces == NULL, "sanity"); 357 set_secondary_supers(Universe::the_empty_klass_array()); 358 return NULL; 359 } 360 361 362 // superklass links 363 InstanceKlass* Klass::superklass() const { 364 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass"); 365 return _super == NULL ? NULL : InstanceKlass::cast(_super); 366 } 367 368 // subklass links. Used by the compiler (and vtable initialization) 369 // May be cleaned concurrently, so must use the Compile_lock. 370 // The log parameter is for clean_weak_klass_links to report unlinked classes. 371 Klass* Klass::subklass(bool log) const { 372 // Need load_acquire on the _subklass, because it races with inserts that 373 // publishes freshly initialized data. 374 for (Klass* chain = Atomic::load_acquire(&_subklass); 375 chain != NULL; 376 // Do not need load_acquire on _next_sibling, because inserts never 377 // create _next_sibling edges to dead data. 378 chain = Atomic::load(&chain->_next_sibling)) 379 { 380 if (chain->is_loader_alive()) { 381 return chain; 382 } else if (log) { 383 if (log_is_enabled(Trace, class, unload)) { 384 ResourceMark rm; 385 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name()); 386 } 387 } 388 } 389 return NULL; 390 } 391 392 Klass* Klass::next_sibling(bool log) const { 393 // Do not need load_acquire on _next_sibling, because inserts never 394 // create _next_sibling edges to dead data. 395 for (Klass* chain = Atomic::load(&_next_sibling); 396 chain != NULL; 397 chain = Atomic::load(&chain->_next_sibling)) { 398 // Only return alive klass, there may be stale klass 399 // in this chain if cleaned concurrently. 400 if (chain->is_loader_alive()) { 401 return chain; 402 } else if (log) { 403 if (log_is_enabled(Trace, class, unload)) { 404 ResourceMark rm; 405 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name()); 406 } 407 } 408 } 409 return NULL; 410 } 411 412 void Klass::set_subklass(Klass* s) { 413 assert(s != this, "sanity check"); 414 Atomic::release_store(&_subklass, s); 415 } 416 417 void Klass::set_next_sibling(Klass* s) { 418 assert(s != this, "sanity check"); 419 // Does not need release semantics. If used by cleanup, it will link to 420 // already safely published data, and if used by inserts, will be published 421 // safely using cmpxchg. 422 Atomic::store(&_next_sibling, s); 423 } 424 425 void Klass::append_to_sibling_list() { 426 if (Universe::is_fully_initialized()) { 427 assert_locked_or_safepoint(Compile_lock); 428 } 429 debug_only(verify();) 430 // add ourselves to superklass' subklass list 431 InstanceKlass* super = superklass(); 432 if (super == NULL) return; // special case: class Object 433 assert((!super->is_interface() // interfaces cannot be supers 434 && (super->superklass() == NULL || !is_interface())), 435 "an interface can only be a subklass of Object"); 436 437 // Make sure there is no stale subklass head 438 super->clean_subklass(); 439 440 for (;;) { 441 Klass* prev_first_subklass = Atomic::load_acquire(&_super->_subklass); 442 if (prev_first_subklass != NULL) { 443 // set our sibling to be the superklass' previous first subklass 444 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses"); 445 set_next_sibling(prev_first_subklass); 446 } 447 // Note that the prev_first_subklass is always alive, meaning no sibling_next links 448 // are ever created to not alive klasses. This is an important invariant of the lock-free 449 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list. 450 if (Atomic::cmpxchg(&super->_subklass, prev_first_subklass, this) == prev_first_subklass) { 451 return; 452 } 453 } 454 debug_only(verify();) 455 } 456 457 void Klass::clean_subklass() { 458 for (;;) { 459 // Need load_acquire, due to contending with concurrent inserts 460 Klass* subklass = Atomic::load_acquire(&_subklass); 461 if (subklass == NULL || subklass->is_loader_alive()) { 462 return; 463 } 464 // Try to fix _subklass until it points at something not dead. 465 Atomic::cmpxchg(&_subklass, subklass, subklass->next_sibling()); 466 } 467 } 468 469 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) { 470 if (!ClassUnloading || !unloading_occurred) { 471 return; 472 } 473 474 Klass* root = vmClasses::Object_klass(); 475 Stack<Klass*, mtGC> stack; 476 477 stack.push(root); 478 while (!stack.is_empty()) { 479 Klass* current = stack.pop(); 480 481 assert(current->is_loader_alive(), "just checking, this should be live"); 482 483 // Find and set the first alive subklass 484 Klass* sub = current->subklass(true); 485 current->clean_subklass(); 486 if (sub != NULL) { 487 stack.push(sub); 488 } 489 490 // Find and set the first alive sibling 491 Klass* sibling = current->next_sibling(true); 492 current->set_next_sibling(sibling); 493 if (sibling != NULL) { 494 stack.push(sibling); 495 } 496 497 // Clean the implementors list and method data. 498 if (clean_alive_klasses && current->is_instance_klass()) { 499 InstanceKlass* ik = InstanceKlass::cast(current); 500 ik->clean_weak_instanceklass_links(); 501 502 // JVMTI RedefineClasses creates previous versions that are not in 503 // the class hierarchy, so process them here. 504 while ((ik = ik->previous_versions()) != NULL) { 505 ik->clean_weak_instanceklass_links(); 506 } 507 } 508 } 509 } 510 511 void Klass::metaspace_pointers_do(MetaspaceClosure* it) { 512 if (log_is_enabled(Trace, cds)) { 513 ResourceMark rm; 514 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name()); 515 } 516 517 it->push(&_name); 518 it->push(&_secondary_super_cache); 519 it->push(&_secondary_supers); 520 for (int i = 0; i < _primary_super_limit; i++) { 521 it->push(&_primary_supers[i]); 522 } 523 it->push(&_super); 524 if (!Arguments::is_dumping_archive()) { 525 // If dumping archive, these may point to excluded classes. There's no need 526 // to follow these pointers anyway, as they will be set to NULL in 527 // remove_unshareable_info(). 528 it->push((Klass**)&_subklass); 529 it->push((Klass**)&_next_sibling); 530 it->push(&_next_link); 531 } 532 533 vtableEntry* vt = start_of_vtable(); 534 for (int i=0; i<vtable_length(); i++) { 535 it->push(vt[i].method_addr()); 536 } 537 } 538 539 #if INCLUDE_CDS 540 void Klass::remove_unshareable_info() { 541 assert (Arguments::is_dumping_archive(), 542 "only called during CDS dump time"); 543 JFR_ONLY(REMOVE_ID(this);) 544 if (log_is_enabled(Trace, cds, unshareable)) { 545 ResourceMark rm; 546 log_trace(cds, unshareable)("remove: %s", external_name()); 547 } 548 549 set_subklass(NULL); 550 set_next_sibling(NULL); 551 set_next_link(NULL); 552 553 // Null out class_loader_data because we don't share that yet. 554 set_class_loader_data(NULL); 555 set_is_shared(); 556 } 557 558 void Klass::remove_java_mirror() { 559 Arguments::assert_is_dumping_archive(); 560 if (log_is_enabled(Trace, cds, unshareable)) { 561 ResourceMark rm; 562 log_trace(cds, unshareable)("remove java_mirror: %s", external_name()); 563 } 564 // Just null out the mirror. The class_loader_data() no longer exists. 565 clear_java_mirror_handle(); 566 } 567 568 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 569 assert(is_klass(), "ensure C++ vtable is restored"); 570 assert(is_shared(), "must be set"); 571 JFR_ONLY(RESTORE_ID(this);) 572 if (log_is_enabled(Trace, cds, unshareable)) { 573 ResourceMark rm(THREAD); 574 log_trace(cds, unshareable)("restore: %s", external_name()); 575 } 576 577 // If an exception happened during CDS restore, some of these fields may already be 578 // set. We leave the class on the CLD list, even if incomplete so that we don't 579 // modify the CLD list outside a safepoint. 580 if (class_loader_data() == NULL) { 581 set_class_loader_data(loader_data); 582 583 // Add to class loader list first before creating the mirror 584 // (same order as class file parsing) 585 loader_data->add_class(this); 586 } 587 588 Handle loader(THREAD, loader_data->class_loader()); 589 ModuleEntry* module_entry = NULL; 590 Klass* k = this; 591 if (k->is_objArray_klass()) { 592 k = ObjArrayKlass::cast(k)->bottom_klass(); 593 } 594 // Obtain klass' module. 595 if (k->is_instance_klass()) { 596 InstanceKlass* ik = (InstanceKlass*) k; 597 module_entry = ik->module(); 598 } else { 599 module_entry = ModuleEntryTable::javabase_moduleEntry(); 600 } 601 // Obtain java.lang.Module, if available 602 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL)); 603 604 if (this->has_archived_mirror_index()) { 605 ResourceMark rm(THREAD); 606 log_debug(cds, mirror)("%s has raw archived mirror", external_name()); 607 if (ArchiveHeapLoader::are_archived_mirrors_available()) { 608 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle, 609 protection_domain, 610 CHECK); 611 if (present) { 612 return; 613 } 614 } 615 616 // No archived mirror data 617 log_debug(cds, mirror)("No archived mirror data for %s", external_name()); 618 clear_java_mirror_handle(); 619 this->clear_archived_mirror_index(); 620 } 621 622 // Only recreate it if not present. A previous attempt to restore may have 623 // gotten an OOM later but keep the mirror if it was created. 624 if (java_mirror() == NULL) { 625 ResourceMark rm(THREAD); 626 log_trace(cds, mirror)("Recreate mirror for %s", external_name()); 627 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, Handle(), CHECK); 628 } 629 } 630 #endif // INCLUDE_CDS 631 632 #if INCLUDE_CDS_JAVA_HEAP 633 oop Klass::archived_java_mirror() { 634 assert(has_archived_mirror_index(), "must have archived mirror"); 635 return HeapShared::get_root(_archived_mirror_index); 636 } 637 638 void Klass::clear_archived_mirror_index() { 639 if (_archived_mirror_index >= 0) { 640 HeapShared::clear_root(_archived_mirror_index); 641 } 642 _archived_mirror_index = -1; 643 } 644 645 // No GC barrier 646 void Klass::set_archived_java_mirror(oop m) { 647 assert(DumpSharedSpaces, "called only during runtime"); 648 _archived_mirror_index = HeapShared::append_root(m); 649 } 650 #endif // INCLUDE_CDS_JAVA_HEAP 651 652 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) { 653 if (length > max_length) { 654 if (!THREAD->in_retryable_allocation()) { 655 report_java_out_of_memory("Requested array size exceeds VM limit"); 656 JvmtiExport::post_array_size_exhausted(); 657 THROW_OOP(Universe::out_of_memory_error_array_size()); 658 } else { 659 THROW_OOP(Universe::out_of_memory_error_retry()); 660 } 661 } else if (length < 0) { 662 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length)); 663 } 664 } 665 666 // Replace the last '+' char with '/'. 667 static char* convert_hidden_name_to_java(Symbol* name) { 668 size_t name_len = name->utf8_length(); 669 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1); 670 name->as_klass_external_name(result, (int)name_len + 1); 671 for (int index = (int)name_len; index > 0; index--) { 672 if (result[index] == '+') { 673 result[index] = JVM_SIGNATURE_SLASH; 674 break; 675 } 676 } 677 return result; 678 } 679 680 // In product mode, this function doesn't have virtual function calls so 681 // there might be some performance advantage to handling InstanceKlass here. 682 const char* Klass::external_name() const { 683 if (is_instance_klass()) { 684 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this); 685 if (ik->is_hidden()) { 686 char* result = convert_hidden_name_to_java(name()); 687 return result; 688 } 689 } else if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) { 690 char* result = convert_hidden_name_to_java(name()); 691 return result; 692 } 693 if (name() == NULL) return "<unknown>"; 694 return name()->as_klass_external_name(); 695 } 696 697 const char* Klass::signature_name() const { 698 if (name() == NULL) return "<unknown>"; 699 if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) { 700 size_t name_len = name()->utf8_length(); 701 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1); 702 name()->as_C_string(result, (int)name_len + 1); 703 for (int index = (int)name_len; index > 0; index--) { 704 if (result[index] == '+') { 705 result[index] = JVM_SIGNATURE_DOT; 706 break; 707 } 708 } 709 return result; 710 } 711 return name()->as_C_string(); 712 } 713 714 const char* Klass::external_kind() const { 715 if (is_interface()) return "interface"; 716 if (is_abstract()) return "abstract class"; 717 return "class"; 718 } 719 720 // Unless overridden, jvmti_class_status has no flags set. 721 jint Klass::jvmti_class_status() const { 722 return 0; 723 } 724 725 726 // Printing 727 728 void Klass::print_on(outputStream* st) const { 729 ResourceMark rm; 730 // print title 731 st->print("%s", internal_name()); 732 print_address_on(st); 733 st->cr(); 734 } 735 736 #define BULLET " - " 737 738 // Caller needs ResourceMark 739 void Klass::oop_print_on(oop obj, outputStream* st) { 740 // print title 741 st->print_cr("%s ", internal_name()); 742 obj->print_address_on(st); 743 744 if (WizardMode) { 745 // print header 746 obj->mark().print_on(st); 747 st->cr(); 748 st->print(BULLET"prototype_header: " INTPTR_FORMAT, _prototype_header.value()); 749 st->cr(); 750 } 751 752 // print class 753 st->print(BULLET"klass: "); 754 obj->klass()->print_value_on(st); 755 st->cr(); 756 } 757 758 void Klass::oop_print_value_on(oop obj, outputStream* st) { 759 // print title 760 ResourceMark rm; // Cannot print in debug mode without this 761 st->print("%s", internal_name()); 762 obj->print_address_on(st); 763 } 764 765 // Verification 766 767 void Klass::verify_on(outputStream* st) { 768 769 // This can be expensive, but it is worth checking that this klass is actually 770 // in the CLD graph but not in production. 771 assert(Metaspace::contains((address)this), "Should be"); 772 773 guarantee(this->is_klass(),"should be klass"); 774 775 if (super() != NULL) { 776 guarantee(super()->is_klass(), "should be klass"); 777 } 778 if (secondary_super_cache() != NULL) { 779 Klass* ko = secondary_super_cache(); 780 guarantee(ko->is_klass(), "should be klass"); 781 } 782 for ( uint i = 0; i < primary_super_limit(); i++ ) { 783 Klass* ko = _primary_supers[i]; 784 if (ko != NULL) { 785 guarantee(ko->is_klass(), "should be klass"); 786 } 787 } 788 789 if (java_mirror_no_keepalive() != NULL) { 790 guarantee(java_lang_Class::is_instance(java_mirror_no_keepalive()), "should be instance"); 791 } 792 } 793 794 void Klass::oop_verify_on(oop obj, outputStream* st) { 795 guarantee(oopDesc::is_oop(obj), "should be oop"); 796 guarantee(obj->klass()->is_klass(), "klass field is not a klass"); 797 } 798 799 bool Klass::is_valid(Klass* k) { 800 if (!is_aligned(k, sizeof(MetaWord))) return false; 801 if ((size_t)k < os::min_page_size()) return false; 802 803 if (!os::is_readable_range(k, k + 1)) return false; 804 if (!Metaspace::contains(k)) return false; 805 806 if (!Symbol::is_valid(k->name())) return false; 807 return ClassLoaderDataGraph::is_valid(k->class_loader_data()); 808 } 809 810 Method* Klass::method_at_vtable(int index) { 811 #ifndef PRODUCT 812 assert(index >= 0, "valid vtable index"); 813 if (DebugVtables) { 814 verify_vtable_index(index); 815 } 816 #endif 817 return start_of_vtable()[index].method(); 818 } 819 820 821 #ifndef PRODUCT 822 823 bool Klass::verify_vtable_index(int i) { 824 int limit = vtable_length()/vtableEntry::size(); 825 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit); 826 return true; 827 } 828 829 #endif // PRODUCT 830 831 // Caller needs ResourceMark 832 // joint_in_module_of_loader provides an optimization if 2 classes are in 833 // the same module to succinctly print out relevant information about their 834 // module name and class loader's name_and_id for error messages. 835 // Format: 836 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2> 837 // are in module <module-name>[@<version>] 838 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 839 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const { 840 assert(module() == class2->module(), "classes do not have the same module"); 841 const char* class1_name = external_name(); 842 size_t len = strlen(class1_name) + 1; 843 844 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader); 845 len += strlen(class2_description); 846 847 len += strlen(" and "); 848 849 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 850 851 // Just return the FQN if error when allocating string 852 if (joint_description == NULL) { 853 return class1_name; 854 } 855 856 jio_snprintf(joint_description, len, "%s and %s", 857 class1_name, 858 class2_description); 859 860 return joint_description; 861 } 862 863 // Caller needs ResourceMark 864 // class_in_module_of_loader provides a standard way to include 865 // relevant information about a class, such as its module name as 866 // well as its class loader's name_and_id, in error messages and logging. 867 // Format: 868 // <fully-qualified-external-class-name> is in module <module-name>[@<version>] 869 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 870 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const { 871 // 1. fully qualified external name of class 872 const char* klass_name = external_name(); 873 size_t len = strlen(klass_name) + 1; 874 875 // 2. module name + @version 876 const char* module_name = ""; 877 const char* version = ""; 878 bool has_version = false; 879 bool module_is_named = false; 880 const char* module_name_phrase = ""; 881 const Klass* bottom_klass = is_objArray_klass() ? 882 ObjArrayKlass::cast(this)->bottom_klass() : this; 883 if (bottom_klass->is_instance_klass()) { 884 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module(); 885 if (module->is_named()) { 886 module_is_named = true; 887 module_name_phrase = "module "; 888 module_name = module->name()->as_C_string(); 889 len += strlen(module_name); 890 // Use version if exists and is not a jdk module 891 if (module->should_show_version()) { 892 has_version = true; 893 version = module->version()->as_C_string(); 894 // Include stlen(version) + 1 for the "@" 895 len += strlen(version) + 1; 896 } 897 } else { 898 module_name = UNNAMED_MODULE; 899 len += UNNAMED_MODULE_LEN; 900 } 901 } else { 902 // klass is an array of primitives, module is java.base 903 module_is_named = true; 904 module_name_phrase = "module "; 905 module_name = JAVA_BASE_NAME; 906 len += JAVA_BASE_NAME_LEN; 907 } 908 909 // 3. class loader's name_and_id 910 ClassLoaderData* cld = class_loader_data(); 911 assert(cld != NULL, "class_loader_data should not be null"); 912 const char* loader_name_and_id = cld->loader_name_and_id(); 913 len += strlen(loader_name_and_id); 914 915 // 4. include parent loader information 916 const char* parent_loader_phrase = ""; 917 const char* parent_loader_name_and_id = ""; 918 if (include_parent_loader && 919 !cld->is_builtin_class_loader_data()) { 920 oop parent_loader = java_lang_ClassLoader::parent(class_loader()); 921 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data_or_null(parent_loader); 922 // The parent loader's ClassLoaderData could be null if it is 923 // a delegating class loader that has never defined a class. 924 // In this case the loader's name must be obtained via the parent loader's oop. 925 if (parent_cld == NULL) { 926 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader); 927 if (cl_name_and_id != NULL) { 928 parent_loader_name_and_id = java_lang_String::as_utf8_string(cl_name_and_id); 929 } 930 } else { 931 parent_loader_name_and_id = parent_cld->loader_name_and_id(); 932 } 933 parent_loader_phrase = ", parent loader "; 934 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id); 935 } 936 937 // Start to construct final full class description string 938 len += ((use_are) ? strlen(" are in ") : strlen(" is in ")); 939 len += strlen(module_name_phrase) + strlen(" of loader "); 940 941 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 942 943 // Just return the FQN if error when allocating string 944 if (class_description == NULL) { 945 return klass_name; 946 } 947 948 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s", 949 klass_name, 950 (use_are) ? "are" : "is", 951 module_name_phrase, 952 module_name, 953 (has_version) ? "@" : "", 954 (has_version) ? version : "", 955 loader_name_and_id, 956 parent_loader_phrase, 957 parent_loader_name_and_id); 958 959 return class_description; 960 }