1 /* 2 * Copyright (c) 1997, 2021, 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 "jvm_io.h" 27 #include "cds/heapShared.hpp" 28 #include "classfile/classLoaderData.inline.hpp" 29 #include "classfile/classLoaderDataGraph.inline.hpp" 30 #include "classfile/javaClasses.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 "logging/log.hpp" 38 #include "memory/metadataFactory.hpp" 39 #include "memory/metaspaceClosure.hpp" 40 #include "memory/oopFactory.hpp" 41 #include "memory/resourceArea.hpp" 42 #include "memory/universe.hpp" 43 #include "oops/compressedOops.inline.hpp" 44 #include "oops/instanceKlass.hpp" 45 #include "oops/klass.inline.hpp" 46 #include "oops/oop.inline.hpp" 47 #include "oops/oopHandle.inline.hpp" 48 #include "prims/jvmtiExport.hpp" 49 #include "runtime/arguments.hpp" 50 #include "runtime/atomic.hpp" 51 #include "runtime/handles.inline.hpp" 52 #include "utilities/macros.hpp" 53 #include "utilities/powerOfTwo.hpp" 54 #include "utilities/stack.inline.hpp" 55 56 void Klass::set_java_mirror(Handle m) { 57 assert(!m.is_null(), "New mirror should never be null."); 58 assert(_java_mirror.is_empty(), "should only be used to initialize mirror"); 59 _java_mirror = class_loader_data()->add_handle(m); 60 } 61 62 oop Klass::java_mirror_no_keepalive() const { 63 return _java_mirror.peek(); 64 } 65 66 void Klass::replace_java_mirror(oop mirror) { 67 _java_mirror.replace(mirror); 68 } 69 70 bool Klass::is_cloneable() const { 71 return _access_flags.is_cloneable_fast() || 72 is_subtype_of(vmClasses::Cloneable_klass()); 73 } 74 75 void Klass::set_is_cloneable() { 76 if (name() == vmSymbols::java_lang_invoke_MemberName()) { 77 assert(is_final(), "no subclasses allowed"); 78 // MemberName cloning should not be intrinsified and always happen in JVM_Clone. 79 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) { 80 // Reference cloning should not be intrinsified and always happen in JVM_Clone. 81 } else { 82 _access_flags.set_is_cloneable_fast(); 83 } 84 } 85 86 void Klass::set_name(Symbol* n) { 87 _name = n; 88 if (_name != NULL) _name->increment_refcount(); 89 90 if (Arguments::is_dumping_archive() && is_instance_klass()) { 91 SystemDictionaryShared::init_dumptime_info(InstanceKlass::cast(this)); 92 } 93 } 94 95 bool Klass::is_subclass_of(const Klass* k) const { 96 // Run up the super chain and check 97 if (this == k) return true; 98 99 Klass* t = const_cast<Klass*>(this)->super(); 100 101 while (t != NULL) { 102 if (t == k) return true; 103 t = t->super(); 104 } 105 return false; 106 } 107 108 void Klass::release_C_heap_structures(bool release_constant_pool) { 109 if (_name != NULL) _name->decrement_refcount(); 110 } 111 112 bool Klass::search_secondary_supers(Klass* k) const { 113 // Put some extra logic here out-of-line, before the search proper. 114 // This cuts down the size of the inline method. 115 116 // This is necessary, since I am never in my own secondary_super list. 117 if (this == k) 118 return true; 119 // Scan the array-of-objects for a match 120 int cnt = secondary_supers()->length(); 121 for (int i = 0; i < cnt; i++) { 122 if (secondary_supers()->at(i) == k) { 123 ((Klass*)this)->set_secondary_super_cache(k); 124 return true; 125 } 126 } 127 return false; 128 } 129 130 // Return self, except for abstract classes with exactly 1 131 // implementor. Then return the 1 concrete implementation. 132 Klass *Klass::up_cast_abstract() { 133 Klass *r = this; 134 while( r->is_abstract() ) { // Receiver is abstract? 135 Klass *s = r->subklass(); // Check for exactly 1 subklass 136 if (s == NULL || s->next_sibling() != NULL) // Oops; wrong count; give up 137 return this; // Return 'this' as a no-progress flag 138 r = s; // Loop till find concrete class 139 } 140 return r; // Return the 1 concrete class 141 } 142 143 // Find LCA in class hierarchy 144 Klass *Klass::LCA( Klass *k2 ) { 145 Klass *k1 = this; 146 while( 1 ) { 147 if( k1->is_subtype_of(k2) ) return k2; 148 if( k2->is_subtype_of(k1) ) return k1; 149 k1 = k1->super(); 150 k2 = k2->super(); 151 } 152 } 153 154 155 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) { 156 ResourceMark rm(THREAD); 157 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError() 158 : vmSymbols::java_lang_InstantiationException(), external_name()); 159 } 160 161 162 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) { 163 ResourceMark rm(THREAD); 164 assert(s != NULL, "Throw NPE!"); 165 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), 166 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name())); 167 } 168 169 170 void Klass::initialize(TRAPS) { 171 ShouldNotReachHere(); 172 } 173 174 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 175 #ifdef ASSERT 176 tty->print_cr("Error: find_field 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 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, 185 OverpassLookupMode overpass_mode, 186 PrivateLookupMode private_mode) const { 187 #ifdef ASSERT 188 tty->print_cr("Error: uncached_lookup_method called on a klass oop." 189 " Likely error: reflection method does not correctly" 190 " wrap return value in a mirror object."); 191 #endif 192 ShouldNotReachHere(); 193 return NULL; 194 } 195 196 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() { 197 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD); 198 } 199 200 static markWord make_prototype(Klass* kls) { 201 markWord prototype = markWord::prototype(); 202 #ifdef _LP64 203 if (UseCompactObjectHeaders) { 204 prototype = prototype.set_klass(kls); 205 } 206 #endif 207 return prototype; 208 } 209 210 // "Normal" instantiation is preceeded by a MetaspaceObj allocation 211 // which zeros out memory - calloc equivalent. 212 // The constructor is also used from CppVtableCloner, 213 // which doesn't zero out the memory before calling the constructor. 214 Klass::Klass(KlassID id) : _id(id), 215 _prototype_header(make_prototype(this)), 216 _shared_class_path_index(-1) { 217 CDS_ONLY(_shared_class_flags = 0;) 218 CDS_JAVA_HEAP_ONLY(_archived_mirror_index = -1;) 219 _primary_supers[0] = this; 220 set_super_check_offset(in_bytes(primary_supers_offset())); 221 } 222 223 jint Klass::array_layout_helper(BasicType etype) { 224 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype"); 225 // Note that T_ARRAY is not allowed here. 226 int hsize = arrayOopDesc::base_offset_in_bytes(etype); 227 int esize = type2aelembytes(etype); 228 bool isobj = (etype == T_OBJECT); 229 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value; 230 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize)); 231 232 assert(lh < (int)_lh_neutral_value, "must look like an array layout"); 233 assert(layout_helper_is_array(lh), "correct kind"); 234 assert(layout_helper_is_objArray(lh) == isobj, "correct kind"); 235 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind"); 236 assert(layout_helper_header_size(lh) == hsize, "correct decode"); 237 assert(layout_helper_element_type(lh) == etype, "correct decode"); 238 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode"); 239 240 return lh; 241 } 242 243 bool Klass::can_be_primary_super_slow() const { 244 if (super() == NULL) 245 return true; 246 else if (super()->super_depth() >= primary_super_limit()-1) 247 return false; 248 else 249 return true; 250 } 251 252 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) { 253 if (k == NULL) { 254 set_super(NULL); 255 _primary_supers[0] = this; 256 assert(super_depth() == 0, "Object must already be initialized properly"); 257 } else if (k != super() || k == vmClasses::Object_klass()) { 258 assert(super() == NULL || super() == vmClasses::Object_klass(), 259 "initialize this only once to a non-trivial value"); 260 set_super(k); 261 Klass* sup = k; 262 int sup_depth = sup->super_depth(); 263 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit()); 264 if (!can_be_primary_super_slow()) 265 my_depth = primary_super_limit(); 266 for (juint i = 0; i < my_depth; i++) { 267 _primary_supers[i] = sup->_primary_supers[i]; 268 } 269 Klass* *super_check_cell; 270 if (my_depth < primary_super_limit()) { 271 _primary_supers[my_depth] = this; 272 super_check_cell = &_primary_supers[my_depth]; 273 } else { 274 // Overflow of the primary_supers array forces me to be secondary. 275 super_check_cell = &_secondary_super_cache; 276 } 277 set_super_check_offset((address)super_check_cell - (address) this); 278 279 #ifdef ASSERT 280 { 281 juint j = super_depth(); 282 assert(j == my_depth, "computed accessor gets right answer"); 283 Klass* t = this; 284 while (!t->can_be_primary_super()) { 285 t = t->super(); 286 j = t->super_depth(); 287 } 288 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) { 289 assert(primary_super_of_depth(j1) == NULL, "super list padding"); 290 } 291 while (t != NULL) { 292 assert(primary_super_of_depth(j) == t, "super list initialization"); 293 t = t->super(); 294 --j; 295 } 296 assert(j == (juint)-1, "correct depth count"); 297 } 298 #endif 299 } 300 301 if (secondary_supers() == NULL) { 302 303 // Now compute the list of secondary supertypes. 304 // Secondaries can occasionally be on the super chain, 305 // if the inline "_primary_supers" array overflows. 306 int extras = 0; 307 Klass* p; 308 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 309 ++extras; 310 } 311 312 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below 313 314 // Compute the "real" non-extra secondaries. 315 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces); 316 if (secondaries == NULL) { 317 // secondary_supers set by compute_secondary_supers 318 return; 319 } 320 321 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras); 322 323 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 324 int i; // Scan for overflow primaries being duplicates of 2nd'arys 325 326 // This happens frequently for very deeply nested arrays: the 327 // primary superclass chain overflows into the secondary. The 328 // secondary list contains the element_klass's secondaries with 329 // an extra array dimension added. If the element_klass's 330 // secondary list already contains some primary overflows, they 331 // (with the extra level of array-ness) will collide with the 332 // normal primary superclass overflows. 333 for( i = 0; i < secondaries->length(); i++ ) { 334 if( secondaries->at(i) == p ) 335 break; 336 } 337 if( i < secondaries->length() ) 338 continue; // It's a dup, don't put it in 339 primaries->push(p); 340 } 341 // Combine the two arrays into a metadata object to pack the array. 342 // The primaries are added in the reverse order, then the secondaries. 343 int new_length = primaries->length() + secondaries->length(); 344 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>( 345 class_loader_data(), new_length, CHECK); 346 int fill_p = primaries->length(); 347 for (int j = 0; j < fill_p; j++) { 348 s2->at_put(j, primaries->pop()); // add primaries in reverse order. 349 } 350 for( int j = 0; j < secondaries->length(); j++ ) { 351 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end. 352 } 353 354 #ifdef ASSERT 355 // We must not copy any NULL placeholders left over from bootstrap. 356 for (int j = 0; j < s2->length(); j++) { 357 assert(s2->at(j) != NULL, "correct bootstrapping order"); 358 } 359 #endif 360 361 set_secondary_supers(s2); 362 } 363 } 364 365 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots, 366 Array<InstanceKlass*>* transitive_interfaces) { 367 assert(num_extra_slots == 0, "override for complex klasses"); 368 assert(transitive_interfaces == NULL, "sanity"); 369 set_secondary_supers(Universe::the_empty_klass_array()); 370 return NULL; 371 } 372 373 374 // superklass links 375 InstanceKlass* Klass::superklass() const { 376 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass"); 377 return _super == NULL ? NULL : InstanceKlass::cast(_super); 378 } 379 380 // subklass links. Used by the compiler (and vtable initialization) 381 // May be cleaned concurrently, so must use the Compile_lock. 382 // The log parameter is for clean_weak_klass_links to report unlinked classes. 383 Klass* Klass::subklass(bool log) const { 384 // Need load_acquire on the _subklass, because it races with inserts that 385 // publishes freshly initialized data. 386 for (Klass* chain = Atomic::load_acquire(&_subklass); 387 chain != NULL; 388 // Do not need load_acquire on _next_sibling, because inserts never 389 // create _next_sibling edges to dead data. 390 chain = Atomic::load(&chain->_next_sibling)) 391 { 392 if (chain->is_loader_alive()) { 393 return chain; 394 } else if (log) { 395 if (log_is_enabled(Trace, class, unload)) { 396 ResourceMark rm; 397 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name()); 398 } 399 } 400 } 401 return NULL; 402 } 403 404 Klass* Klass::next_sibling(bool log) const { 405 // Do not need load_acquire on _next_sibling, because inserts never 406 // create _next_sibling edges to dead data. 407 for (Klass* chain = Atomic::load(&_next_sibling); 408 chain != NULL; 409 chain = Atomic::load(&chain->_next_sibling)) { 410 // Only return alive klass, there may be stale klass 411 // in this chain if cleaned concurrently. 412 if (chain->is_loader_alive()) { 413 return chain; 414 } else if (log) { 415 if (log_is_enabled(Trace, class, unload)) { 416 ResourceMark rm; 417 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name()); 418 } 419 } 420 } 421 return NULL; 422 } 423 424 void Klass::set_subklass(Klass* s) { 425 assert(s != this, "sanity check"); 426 Atomic::release_store(&_subklass, s); 427 } 428 429 void Klass::set_next_sibling(Klass* s) { 430 assert(s != this, "sanity check"); 431 // Does not need release semantics. If used by cleanup, it will link to 432 // already safely published data, and if used by inserts, will be published 433 // safely using cmpxchg. 434 Atomic::store(&_next_sibling, s); 435 } 436 437 void Klass::append_to_sibling_list() { 438 if (Universe::is_fully_initialized()) { 439 assert_locked_or_safepoint(Compile_lock); 440 } 441 debug_only(verify();) 442 // add ourselves to superklass' subklass list 443 InstanceKlass* super = superklass(); 444 if (super == NULL) return; // special case: class Object 445 assert((!super->is_interface() // interfaces cannot be supers 446 && (super->superklass() == NULL || !is_interface())), 447 "an interface can only be a subklass of Object"); 448 449 // Make sure there is no stale subklass head 450 super->clean_subklass(); 451 452 for (;;) { 453 Klass* prev_first_subklass = Atomic::load_acquire(&_super->_subklass); 454 if (prev_first_subklass != NULL) { 455 // set our sibling to be the superklass' previous first subklass 456 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses"); 457 set_next_sibling(prev_first_subklass); 458 } 459 // Note that the prev_first_subklass is always alive, meaning no sibling_next links 460 // are ever created to not alive klasses. This is an important invariant of the lock-free 461 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list. 462 if (Atomic::cmpxchg(&super->_subklass, prev_first_subklass, this) == prev_first_subklass) { 463 return; 464 } 465 } 466 debug_only(verify();) 467 } 468 469 void Klass::clean_subklass() { 470 for (;;) { 471 // Need load_acquire, due to contending with concurrent inserts 472 Klass* subklass = Atomic::load_acquire(&_subklass); 473 if (subklass == NULL || subklass->is_loader_alive()) { 474 return; 475 } 476 // Try to fix _subklass until it points at something not dead. 477 Atomic::cmpxchg(&_subklass, subklass, subklass->next_sibling()); 478 } 479 } 480 481 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) { 482 if (!ClassUnloading || !unloading_occurred) { 483 return; 484 } 485 486 Klass* root = vmClasses::Object_klass(); 487 Stack<Klass*, mtGC> stack; 488 489 stack.push(root); 490 while (!stack.is_empty()) { 491 Klass* current = stack.pop(); 492 493 assert(current->is_loader_alive(), "just checking, this should be live"); 494 495 // Find and set the first alive subklass 496 Klass* sub = current->subklass(true); 497 current->clean_subklass(); 498 if (sub != NULL) { 499 stack.push(sub); 500 } 501 502 // Find and set the first alive sibling 503 Klass* sibling = current->next_sibling(true); 504 current->set_next_sibling(sibling); 505 if (sibling != NULL) { 506 stack.push(sibling); 507 } 508 509 // Clean the implementors list and method data. 510 if (clean_alive_klasses && current->is_instance_klass()) { 511 InstanceKlass* ik = InstanceKlass::cast(current); 512 ik->clean_weak_instanceklass_links(); 513 514 // JVMTI RedefineClasses creates previous versions that are not in 515 // the class hierarchy, so process them here. 516 while ((ik = ik->previous_versions()) != NULL) { 517 ik->clean_weak_instanceklass_links(); 518 } 519 } 520 } 521 } 522 523 void Klass::metaspace_pointers_do(MetaspaceClosure* it) { 524 if (log_is_enabled(Trace, cds)) { 525 ResourceMark rm; 526 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name()); 527 } 528 529 it->push(&_name); 530 it->push(&_secondary_super_cache); 531 it->push(&_secondary_supers); 532 for (int i = 0; i < _primary_super_limit; i++) { 533 it->push(&_primary_supers[i]); 534 } 535 it->push(&_super); 536 it->push((Klass**)&_subklass); 537 it->push((Klass**)&_next_sibling); 538 it->push(&_next_link); 539 540 vtableEntry* vt = start_of_vtable(); 541 for (int i=0; i<vtable_length(); i++) { 542 it->push(vt[i].method_addr()); 543 } 544 } 545 546 void Klass::remove_unshareable_info() { 547 assert (Arguments::is_dumping_archive(), 548 "only called during CDS dump time"); 549 JFR_ONLY(REMOVE_ID(this);) 550 if (log_is_enabled(Trace, cds, unshareable)) { 551 ResourceMark rm; 552 log_trace(cds, unshareable)("remove: %s", external_name()); 553 } 554 555 set_subklass(NULL); 556 set_next_sibling(NULL); 557 set_next_link(NULL); 558 559 // Null out class_loader_data because we don't share that yet. 560 set_class_loader_data(NULL); 561 set_is_shared(); 562 } 563 564 void Klass::remove_java_mirror() { 565 Arguments::assert_is_dumping_archive(); 566 if (log_is_enabled(Trace, cds, unshareable)) { 567 ResourceMark rm; 568 log_trace(cds, unshareable)("remove java_mirror: %s", external_name()); 569 } 570 // Just null out the mirror. The class_loader_data() no longer exists. 571 clear_java_mirror_handle(); 572 } 573 574 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 575 assert(is_klass(), "ensure C++ vtable is restored"); 576 assert(is_shared(), "must be set"); 577 JFR_ONLY(RESTORE_ID(this);) 578 if (log_is_enabled(Trace, cds, unshareable)) { 579 ResourceMark rm(THREAD); 580 log_trace(cds, unshareable)("restore: %s", external_name()); 581 } 582 583 // If an exception happened during CDS restore, some of these fields may already be 584 // set. We leave the class on the CLD list, even if incomplete so that we don't 585 // modify the CLD list outside a safepoint. 586 if (class_loader_data() == NULL) { 587 set_class_loader_data(loader_data); 588 589 // Add to class loader list first before creating the mirror 590 // (same order as class file parsing) 591 loader_data->add_class(this); 592 } 593 594 Handle loader(THREAD, loader_data->class_loader()); 595 ModuleEntry* module_entry = NULL; 596 Klass* k = this; 597 if (k->is_objArray_klass()) { 598 k = ObjArrayKlass::cast(k)->bottom_klass(); 599 } 600 // Obtain klass' module. 601 if (k->is_instance_klass()) { 602 InstanceKlass* ik = (InstanceKlass*) k; 603 module_entry = ik->module(); 604 } else { 605 module_entry = ModuleEntryTable::javabase_moduleEntry(); 606 } 607 // Obtain java.lang.Module, if available 608 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL)); 609 610 if (this->has_archived_mirror_index()) { 611 ResourceMark rm(THREAD); 612 log_debug(cds, mirror)("%s has raw archived mirror", external_name()); 613 if (HeapShared::open_archive_heap_region_mapped()) { 614 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle, 615 protection_domain, 616 CHECK); 617 if (present) { 618 return; 619 } 620 } 621 622 // No archived mirror data 623 log_debug(cds, mirror)("No archived mirror data for %s", external_name()); 624 clear_java_mirror_handle(); 625 this->clear_archived_mirror_index(); 626 } 627 628 // Only recreate it if not present. A previous attempt to restore may have 629 // gotten an OOM later but keep the mirror if it was created. 630 if (java_mirror() == NULL) { 631 ResourceMark rm(THREAD); 632 log_trace(cds, mirror)("Recreate mirror for %s", external_name()); 633 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, Handle(), CHECK); 634 } 635 } 636 637 #if INCLUDE_CDS_JAVA_HEAP 638 oop Klass::archived_java_mirror() { 639 assert(has_archived_mirror_index(), "must have archived mirror"); 640 return HeapShared::get_root(_archived_mirror_index); 641 } 642 643 void Klass::clear_archived_mirror_index() { 644 if (_archived_mirror_index >= 0) { 645 HeapShared::clear_root(_archived_mirror_index); 646 } 647 _archived_mirror_index = -1; 648 } 649 650 // No GC barrier 651 void Klass::set_archived_java_mirror(oop m) { 652 assert(DumpSharedSpaces, "called only during runtime"); 653 _archived_mirror_index = HeapShared::append_root(m); 654 } 655 #endif // INCLUDE_CDS_JAVA_HEAP 656 657 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) { 658 if (length > max_length) { 659 if (!THREAD->in_retryable_allocation()) { 660 report_java_out_of_memory("Requested array size exceeds VM limit"); 661 JvmtiExport::post_array_size_exhausted(); 662 THROW_OOP(Universe::out_of_memory_error_array_size()); 663 } else { 664 THROW_OOP(Universe::out_of_memory_error_retry()); 665 } 666 } else if (length < 0) { 667 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length)); 668 } 669 } 670 671 // Replace the last '+' char with '/'. 672 static char* convert_hidden_name_to_java(Symbol* name) { 673 size_t name_len = name->utf8_length(); 674 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1); 675 name->as_klass_external_name(result, (int)name_len + 1); 676 for (int index = (int)name_len; index > 0; index--) { 677 if (result[index] == '+') { 678 result[index] = JVM_SIGNATURE_SLASH; 679 break; 680 } 681 } 682 return result; 683 } 684 685 // In product mode, this function doesn't have virtual function calls so 686 // there might be some performance advantage to handling InstanceKlass here. 687 const char* Klass::external_name() const { 688 if (is_instance_klass()) { 689 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this); 690 if (ik->is_hidden()) { 691 char* result = convert_hidden_name_to_java(name()); 692 return result; 693 } 694 } else if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) { 695 char* result = convert_hidden_name_to_java(name()); 696 return result; 697 } 698 if (name() == NULL) return "<unknown>"; 699 return name()->as_klass_external_name(); 700 } 701 702 const char* Klass::signature_name() const { 703 if (name() == NULL) return "<unknown>"; 704 if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) { 705 size_t name_len = name()->utf8_length(); 706 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1); 707 name()->as_C_string(result, (int)name_len + 1); 708 for (int index = (int)name_len; index > 0; index--) { 709 if (result[index] == '+') { 710 result[index] = JVM_SIGNATURE_DOT; 711 break; 712 } 713 } 714 return result; 715 } 716 return name()->as_C_string(); 717 } 718 719 const char* Klass::external_kind() const { 720 if (is_interface()) return "interface"; 721 if (is_abstract()) return "abstract class"; 722 return "class"; 723 } 724 725 int Klass::atomic_incr_biased_lock_revocation_count() { 726 return (int) Atomic::add(&_biased_lock_revocation_count, 1); 727 } 728 729 // Unless overridden, jvmti_class_status has no flags set. 730 jint Klass::jvmti_class_status() const { 731 return 0; 732 } 733 734 735 // Printing 736 737 void Klass::print_on(outputStream* st) const { 738 ResourceMark rm; 739 // print title 740 st->print("%s", internal_name()); 741 print_address_on(st); 742 st->cr(); 743 } 744 745 #define BULLET " - " 746 747 // Caller needs ResourceMark 748 void Klass::oop_print_on(oop obj, outputStream* st) { 749 // print title 750 st->print_cr("%s ", internal_name()); 751 obj->print_address_on(st); 752 753 if (WizardMode) { 754 // print header 755 obj->mark().print_on(st); 756 st->cr(); 757 st->print(BULLET"prototype_header: " INTPTR_FORMAT, _prototype_header.value()); 758 st->cr(); 759 } 760 761 // print class 762 st->print(BULLET"klass: "); 763 obj->klass()->print_value_on(st); 764 st->cr(); 765 } 766 767 void Klass::oop_print_value_on(oop obj, outputStream* st) { 768 // print title 769 ResourceMark rm; // Cannot print in debug mode without this 770 st->print("%s", internal_name()); 771 obj->print_address_on(st); 772 } 773 774 // Verification 775 776 void Klass::verify_on(outputStream* st) { 777 778 // This can be expensive, but it is worth checking that this klass is actually 779 // in the CLD graph but not in production. 780 assert(Metaspace::contains((address)this), "Should be"); 781 782 guarantee(this->is_klass(),"should be klass"); 783 784 if (super() != NULL) { 785 guarantee(super()->is_klass(), "should be klass"); 786 } 787 if (secondary_super_cache() != NULL) { 788 Klass* ko = secondary_super_cache(); 789 guarantee(ko->is_klass(), "should be klass"); 790 } 791 for ( uint i = 0; i < primary_super_limit(); i++ ) { 792 Klass* ko = _primary_supers[i]; 793 if (ko != NULL) { 794 guarantee(ko->is_klass(), "should be klass"); 795 } 796 } 797 798 if (java_mirror_no_keepalive() != NULL) { 799 guarantee(oopDesc::is_oop(java_mirror_no_keepalive()), "should be instance"); 800 } 801 } 802 803 void Klass::oop_verify_on(oop obj, outputStream* st) { 804 guarantee(oopDesc::is_oop(obj), "should be oop"); 805 guarantee(obj->klass()->is_klass(), "klass field is not a klass"); 806 } 807 808 bool Klass::is_valid(Klass* k) { 809 if (!is_aligned(k, sizeof(MetaWord))) return false; 810 if ((size_t)k < os::min_page_size()) return false; 811 812 if (!os::is_readable_range(k, k + 1)) return false; 813 if (!Metaspace::contains(k)) return false; 814 815 if (!Symbol::is_valid(k->name())) return false; 816 return ClassLoaderDataGraph::is_valid(k->class_loader_data()); 817 } 818 819 Method* Klass::method_at_vtable(int index) { 820 #ifndef PRODUCT 821 assert(index >= 0, "valid vtable index"); 822 if (DebugVtables) { 823 verify_vtable_index(index); 824 } 825 #endif 826 return start_of_vtable()[index].method(); 827 } 828 829 830 #ifndef PRODUCT 831 832 bool Klass::verify_vtable_index(int i) { 833 int limit = vtable_length()/vtableEntry::size(); 834 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit); 835 return true; 836 } 837 838 #endif // PRODUCT 839 840 // Caller needs ResourceMark 841 // joint_in_module_of_loader provides an optimization if 2 classes are in 842 // the same module to succinctly print out relevant information about their 843 // module name and class loader's name_and_id for error messages. 844 // Format: 845 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2> 846 // are in module <module-name>[@<version>] 847 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 848 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const { 849 assert(module() == class2->module(), "classes do not have the same module"); 850 const char* class1_name = external_name(); 851 size_t len = strlen(class1_name) + 1; 852 853 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader); 854 len += strlen(class2_description); 855 856 len += strlen(" and "); 857 858 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 859 860 // Just return the FQN if error when allocating string 861 if (joint_description == NULL) { 862 return class1_name; 863 } 864 865 jio_snprintf(joint_description, len, "%s and %s", 866 class1_name, 867 class2_description); 868 869 return joint_description; 870 } 871 872 // Caller needs ResourceMark 873 // class_in_module_of_loader provides a standard way to include 874 // relevant information about a class, such as its module name as 875 // well as its class loader's name_and_id, in error messages and logging. 876 // Format: 877 // <fully-qualified-external-class-name> is in module <module-name>[@<version>] 878 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 879 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const { 880 // 1. fully qualified external name of class 881 const char* klass_name = external_name(); 882 size_t len = strlen(klass_name) + 1; 883 884 // 2. module name + @version 885 const char* module_name = ""; 886 const char* version = ""; 887 bool has_version = false; 888 bool module_is_named = false; 889 const char* module_name_phrase = ""; 890 const Klass* bottom_klass = is_objArray_klass() ? 891 ObjArrayKlass::cast(this)->bottom_klass() : this; 892 if (bottom_klass->is_instance_klass()) { 893 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module(); 894 if (module->is_named()) { 895 module_is_named = true; 896 module_name_phrase = "module "; 897 module_name = module->name()->as_C_string(); 898 len += strlen(module_name); 899 // Use version if exists and is not a jdk module 900 if (module->should_show_version()) { 901 has_version = true; 902 version = module->version()->as_C_string(); 903 // Include stlen(version) + 1 for the "@" 904 len += strlen(version) + 1; 905 } 906 } else { 907 module_name = UNNAMED_MODULE; 908 len += UNNAMED_MODULE_LEN; 909 } 910 } else { 911 // klass is an array of primitives, module is java.base 912 module_is_named = true; 913 module_name_phrase = "module "; 914 module_name = JAVA_BASE_NAME; 915 len += JAVA_BASE_NAME_LEN; 916 } 917 918 // 3. class loader's name_and_id 919 ClassLoaderData* cld = class_loader_data(); 920 assert(cld != NULL, "class_loader_data should not be null"); 921 const char* loader_name_and_id = cld->loader_name_and_id(); 922 len += strlen(loader_name_and_id); 923 924 // 4. include parent loader information 925 const char* parent_loader_phrase = ""; 926 const char* parent_loader_name_and_id = ""; 927 if (include_parent_loader && 928 !cld->is_builtin_class_loader_data()) { 929 oop parent_loader = java_lang_ClassLoader::parent(class_loader()); 930 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data_or_null(parent_loader); 931 // The parent loader's ClassLoaderData could be null if it is 932 // a delegating class loader that has never defined a class. 933 // In this case the loader's name must be obtained via the parent loader's oop. 934 if (parent_cld == NULL) { 935 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader); 936 if (cl_name_and_id != NULL) { 937 parent_loader_name_and_id = java_lang_String::as_utf8_string(cl_name_and_id); 938 } 939 } else { 940 parent_loader_name_and_id = parent_cld->loader_name_and_id(); 941 } 942 parent_loader_phrase = ", parent loader "; 943 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id); 944 } 945 946 // Start to construct final full class description string 947 len += ((use_are) ? strlen(" are in ") : strlen(" is in ")); 948 len += strlen(module_name_phrase) + strlen(" of loader "); 949 950 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 951 952 // Just return the FQN if error when allocating string 953 if (class_description == NULL) { 954 return klass_name; 955 } 956 957 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s", 958 klass_name, 959 (use_are) ? "are" : "is", 960 module_name_phrase, 961 module_name, 962 (has_version) ? "@" : "", 963 (has_version) ? version : "", 964 loader_name_and_id, 965 parent_loader_phrase, 966 parent_loader_name_and_id); 967 968 return class_description; 969 }