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 // "Normal" instantiation is preceeded by a MetaspaceObj allocation 201 // which zeros out memory - calloc equivalent. 202 // The constructor is also used from CppVtableCloner, 203 // which doesn't zero out the memory before calling the constructor. 204 Klass::Klass(KlassID id) : _id(id), 205 _prototype_header(markWord::prototype()), 206 _shared_class_path_index(-1) { 207 CDS_ONLY(_shared_class_flags = 0;) 208 CDS_JAVA_HEAP_ONLY(_archived_mirror_index = -1;) 209 _primary_supers[0] = this; 210 set_super_check_offset(in_bytes(primary_supers_offset())); 211 } 212 213 jint Klass::array_layout_helper(BasicType etype) { 214 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype"); 215 // Note that T_ARRAY is not allowed here. 216 int hsize = arrayOopDesc::base_offset_in_bytes(etype); 217 int esize = type2aelembytes(etype); 218 bool isobj = (etype == T_OBJECT); 219 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value; 220 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize)); 221 222 assert(lh < (int)_lh_neutral_value, "must look like an array layout"); 223 assert(layout_helper_is_array(lh), "correct kind"); 224 assert(layout_helper_is_objArray(lh) == isobj, "correct kind"); 225 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind"); 226 assert(layout_helper_header_size(lh) == hsize, "correct decode"); 227 assert(layout_helper_element_type(lh) == etype, "correct decode"); 228 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode"); 229 230 return lh; 231 } 232 233 bool Klass::can_be_primary_super_slow() const { 234 if (super() == NULL) 235 return true; 236 else if (super()->super_depth() >= primary_super_limit()-1) 237 return false; 238 else 239 return true; 240 } 241 242 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) { 243 if (k == NULL) { 244 set_super(NULL); 245 _primary_supers[0] = this; 246 assert(super_depth() == 0, "Object must already be initialized properly"); 247 } else if (k != super() || k == vmClasses::Object_klass()) { 248 assert(super() == NULL || super() == vmClasses::Object_klass(), 249 "initialize this only once to a non-trivial value"); 250 set_super(k); 251 Klass* sup = k; 252 int sup_depth = sup->super_depth(); 253 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit()); 254 if (!can_be_primary_super_slow()) 255 my_depth = primary_super_limit(); 256 for (juint i = 0; i < my_depth; i++) { 257 _primary_supers[i] = sup->_primary_supers[i]; 258 } 259 Klass* *super_check_cell; 260 if (my_depth < primary_super_limit()) { 261 _primary_supers[my_depth] = this; 262 super_check_cell = &_primary_supers[my_depth]; 263 } else { 264 // Overflow of the primary_supers array forces me to be secondary. 265 super_check_cell = &_secondary_super_cache; 266 } 267 set_super_check_offset((address)super_check_cell - (address) this); 268 269 #ifdef ASSERT 270 { 271 juint j = super_depth(); 272 assert(j == my_depth, "computed accessor gets right answer"); 273 Klass* t = this; 274 while (!t->can_be_primary_super()) { 275 t = t->super(); 276 j = t->super_depth(); 277 } 278 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) { 279 assert(primary_super_of_depth(j1) == NULL, "super list padding"); 280 } 281 while (t != NULL) { 282 assert(primary_super_of_depth(j) == t, "super list initialization"); 283 t = t->super(); 284 --j; 285 } 286 assert(j == (juint)-1, "correct depth count"); 287 } 288 #endif 289 } 290 291 if (secondary_supers() == NULL) { 292 293 // Now compute the list of secondary supertypes. 294 // Secondaries can occasionally be on the super chain, 295 // if the inline "_primary_supers" array overflows. 296 int extras = 0; 297 Klass* p; 298 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 299 ++extras; 300 } 301 302 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below 303 304 // Compute the "real" non-extra secondaries. 305 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces); 306 if (secondaries == NULL) { 307 // secondary_supers set by compute_secondary_supers 308 return; 309 } 310 311 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras); 312 313 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 314 int i; // Scan for overflow primaries being duplicates of 2nd'arys 315 316 // This happens frequently for very deeply nested arrays: the 317 // primary superclass chain overflows into the secondary. The 318 // secondary list contains the element_klass's secondaries with 319 // an extra array dimension added. If the element_klass's 320 // secondary list already contains some primary overflows, they 321 // (with the extra level of array-ness) will collide with the 322 // normal primary superclass overflows. 323 for( i = 0; i < secondaries->length(); i++ ) { 324 if( secondaries->at(i) == p ) 325 break; 326 } 327 if( i < secondaries->length() ) 328 continue; // It's a dup, don't put it in 329 primaries->push(p); 330 } 331 // Combine the two arrays into a metadata object to pack the array. 332 // The primaries are added in the reverse order, then the secondaries. 333 int new_length = primaries->length() + secondaries->length(); 334 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>( 335 class_loader_data(), new_length, CHECK); 336 int fill_p = primaries->length(); 337 for (int j = 0; j < fill_p; j++) { 338 s2->at_put(j, primaries->pop()); // add primaries in reverse order. 339 } 340 for( int j = 0; j < secondaries->length(); j++ ) { 341 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end. 342 } 343 344 #ifdef ASSERT 345 // We must not copy any NULL placeholders left over from bootstrap. 346 for (int j = 0; j < s2->length(); j++) { 347 assert(s2->at(j) != NULL, "correct bootstrapping order"); 348 } 349 #endif 350 351 set_secondary_supers(s2); 352 } 353 } 354 355 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots, 356 Array<InstanceKlass*>* transitive_interfaces) { 357 assert(num_extra_slots == 0, "override for complex klasses"); 358 assert(transitive_interfaces == NULL, "sanity"); 359 set_secondary_supers(Universe::the_empty_klass_array()); 360 return NULL; 361 } 362 363 364 // superklass links 365 InstanceKlass* Klass::superklass() const { 366 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass"); 367 return _super == NULL ? NULL : InstanceKlass::cast(_super); 368 } 369 370 // subklass links. Used by the compiler (and vtable initialization) 371 // May be cleaned concurrently, so must use the Compile_lock. 372 // The log parameter is for clean_weak_klass_links to report unlinked classes. 373 Klass* Klass::subklass(bool log) const { 374 // Need load_acquire on the _subklass, because it races with inserts that 375 // publishes freshly initialized data. 376 for (Klass* chain = Atomic::load_acquire(&_subklass); 377 chain != NULL; 378 // Do not need load_acquire on _next_sibling, because inserts never 379 // create _next_sibling edges to dead data. 380 chain = Atomic::load(&chain->_next_sibling)) 381 { 382 if (chain->is_loader_alive()) { 383 return chain; 384 } else if (log) { 385 if (log_is_enabled(Trace, class, unload)) { 386 ResourceMark rm; 387 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name()); 388 } 389 } 390 } 391 return NULL; 392 } 393 394 Klass* Klass::next_sibling(bool log) const { 395 // Do not need load_acquire on _next_sibling, because inserts never 396 // create _next_sibling edges to dead data. 397 for (Klass* chain = Atomic::load(&_next_sibling); 398 chain != NULL; 399 chain = Atomic::load(&chain->_next_sibling)) { 400 // Only return alive klass, there may be stale klass 401 // in this chain if cleaned concurrently. 402 if (chain->is_loader_alive()) { 403 return chain; 404 } else if (log) { 405 if (log_is_enabled(Trace, class, unload)) { 406 ResourceMark rm; 407 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name()); 408 } 409 } 410 } 411 return NULL; 412 } 413 414 void Klass::set_subklass(Klass* s) { 415 assert(s != this, "sanity check"); 416 Atomic::release_store(&_subklass, s); 417 } 418 419 void Klass::set_next_sibling(Klass* s) { 420 assert(s != this, "sanity check"); 421 // Does not need release semantics. If used by cleanup, it will link to 422 // already safely published data, and if used by inserts, will be published 423 // safely using cmpxchg. 424 Atomic::store(&_next_sibling, s); 425 } 426 427 void Klass::append_to_sibling_list() { 428 if (Universe::is_fully_initialized()) { 429 assert_locked_or_safepoint(Compile_lock); 430 } 431 debug_only(verify();) 432 // add ourselves to superklass' subklass list 433 InstanceKlass* super = superklass(); 434 if (super == NULL) return; // special case: class Object 435 assert((!super->is_interface() // interfaces cannot be supers 436 && (super->superklass() == NULL || !is_interface())), 437 "an interface can only be a subklass of Object"); 438 439 // Make sure there is no stale subklass head 440 super->clean_subklass(); 441 442 for (;;) { 443 Klass* prev_first_subklass = Atomic::load_acquire(&_super->_subklass); 444 if (prev_first_subklass != NULL) { 445 // set our sibling to be the superklass' previous first subklass 446 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses"); 447 set_next_sibling(prev_first_subklass); 448 } 449 // Note that the prev_first_subklass is always alive, meaning no sibling_next links 450 // are ever created to not alive klasses. This is an important invariant of the lock-free 451 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list. 452 if (Atomic::cmpxchg(&super->_subklass, prev_first_subklass, this) == prev_first_subklass) { 453 return; 454 } 455 } 456 debug_only(verify();) 457 } 458 459 void Klass::clean_subklass() { 460 for (;;) { 461 // Need load_acquire, due to contending with concurrent inserts 462 Klass* subklass = Atomic::load_acquire(&_subklass); 463 if (subklass == NULL || subklass->is_loader_alive()) { 464 return; 465 } 466 // Try to fix _subklass until it points at something not dead. 467 Atomic::cmpxchg(&_subklass, subklass, subklass->next_sibling()); 468 } 469 } 470 471 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) { 472 if (!ClassUnloading || !unloading_occurred) { 473 return; 474 } 475 476 Klass* root = vmClasses::Object_klass(); 477 Stack<Klass*, mtGC> stack; 478 479 stack.push(root); 480 while (!stack.is_empty()) { 481 Klass* current = stack.pop(); 482 483 assert(current->is_loader_alive(), "just checking, this should be live"); 484 485 // Find and set the first alive subklass 486 Klass* sub = current->subklass(true); 487 current->clean_subklass(); 488 if (sub != NULL) { 489 stack.push(sub); 490 } 491 492 // Find and set the first alive sibling 493 Klass* sibling = current->next_sibling(true); 494 current->set_next_sibling(sibling); 495 if (sibling != NULL) { 496 stack.push(sibling); 497 } 498 499 // Clean the implementors list and method data. 500 if (clean_alive_klasses && current->is_instance_klass()) { 501 InstanceKlass* ik = InstanceKlass::cast(current); 502 ik->clean_weak_instanceklass_links(); 503 504 // JVMTI RedefineClasses creates previous versions that are not in 505 // the class hierarchy, so process them here. 506 while ((ik = ik->previous_versions()) != NULL) { 507 ik->clean_weak_instanceklass_links(); 508 } 509 } 510 } 511 } 512 513 void Klass::metaspace_pointers_do(MetaspaceClosure* it) { 514 if (log_is_enabled(Trace, cds)) { 515 ResourceMark rm; 516 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name()); 517 } 518 519 it->push(&_name); 520 it->push(&_secondary_super_cache); 521 it->push(&_secondary_supers); 522 for (int i = 0; i < _primary_super_limit; i++) { 523 it->push(&_primary_supers[i]); 524 } 525 it->push(&_super); 526 it->push((Klass**)&_subklass); 527 it->push((Klass**)&_next_sibling); 528 it->push(&_next_link); 529 530 vtableEntry* vt = start_of_vtable(); 531 for (int i=0; i<vtable_length(); i++) { 532 it->push(vt[i].method_addr()); 533 } 534 } 535 536 void Klass::remove_unshareable_info() { 537 assert (Arguments::is_dumping_archive(), 538 "only called during CDS dump time"); 539 JFR_ONLY(REMOVE_ID(this);) 540 if (log_is_enabled(Trace, cds, unshareable)) { 541 ResourceMark rm; 542 log_trace(cds, unshareable)("remove: %s", external_name()); 543 } 544 545 set_subklass(NULL); 546 set_next_sibling(NULL); 547 set_next_link(NULL); 548 549 // Null out class_loader_data because we don't share that yet. 550 set_class_loader_data(NULL); 551 set_is_shared(); 552 } 553 554 void Klass::remove_java_mirror() { 555 Arguments::assert_is_dumping_archive(); 556 if (log_is_enabled(Trace, cds, unshareable)) { 557 ResourceMark rm; 558 log_trace(cds, unshareable)("remove java_mirror: %s", external_name()); 559 } 560 // Just null out the mirror. The class_loader_data() no longer exists. 561 clear_java_mirror_handle(); 562 } 563 564 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 565 assert(is_klass(), "ensure C++ vtable is restored"); 566 assert(is_shared(), "must be set"); 567 JFR_ONLY(RESTORE_ID(this);) 568 if (log_is_enabled(Trace, cds, unshareable)) { 569 ResourceMark rm(THREAD); 570 log_trace(cds, unshareable)("restore: %s", external_name()); 571 } 572 573 // If an exception happened during CDS restore, some of these fields may already be 574 // set. We leave the class on the CLD list, even if incomplete so that we don't 575 // modify the CLD list outside a safepoint. 576 if (class_loader_data() == NULL) { 577 set_class_loader_data(loader_data); 578 579 // Add to class loader list first before creating the mirror 580 // (same order as class file parsing) 581 loader_data->add_class(this); 582 } 583 584 Handle loader(THREAD, loader_data->class_loader()); 585 ModuleEntry* module_entry = NULL; 586 Klass* k = this; 587 if (k->is_objArray_klass()) { 588 k = ObjArrayKlass::cast(k)->bottom_klass(); 589 } 590 // Obtain klass' module. 591 if (k->is_instance_klass()) { 592 InstanceKlass* ik = (InstanceKlass*) k; 593 module_entry = ik->module(); 594 } else { 595 module_entry = ModuleEntryTable::javabase_moduleEntry(); 596 } 597 // Obtain java.lang.Module, if available 598 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL)); 599 600 if (this->has_archived_mirror_index()) { 601 ResourceMark rm(THREAD); 602 log_debug(cds, mirror)("%s has raw archived mirror", external_name()); 603 if (HeapShared::open_archive_heap_region_mapped()) { 604 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle, 605 protection_domain, 606 CHECK); 607 if (present) { 608 return; 609 } 610 } 611 612 // No archived mirror data 613 log_debug(cds, mirror)("No archived mirror data for %s", external_name()); 614 clear_java_mirror_handle(); 615 this->clear_archived_mirror_index(); 616 } 617 618 // Only recreate it if not present. A previous attempt to restore may have 619 // gotten an OOM later but keep the mirror if it was created. 620 if (java_mirror() == NULL) { 621 ResourceMark rm(THREAD); 622 log_trace(cds, mirror)("Recreate mirror for %s", external_name()); 623 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, Handle(), CHECK); 624 } 625 } 626 627 #if INCLUDE_CDS_JAVA_HEAP 628 oop Klass::archived_java_mirror() { 629 assert(has_archived_mirror_index(), "must have archived mirror"); 630 return HeapShared::get_root(_archived_mirror_index); 631 } 632 633 void Klass::clear_archived_mirror_index() { 634 if (_archived_mirror_index >= 0) { 635 HeapShared::clear_root(_archived_mirror_index); 636 } 637 _archived_mirror_index = -1; 638 } 639 640 // No GC barrier 641 void Klass::set_archived_java_mirror(oop m) { 642 assert(DumpSharedSpaces, "called only during runtime"); 643 _archived_mirror_index = HeapShared::append_root(m); 644 } 645 #endif // INCLUDE_CDS_JAVA_HEAP 646 647 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) { 648 if (length > max_length) { 649 if (!THREAD->in_retryable_allocation()) { 650 report_java_out_of_memory("Requested array size exceeds VM limit"); 651 JvmtiExport::post_array_size_exhausted(); 652 THROW_OOP(Universe::out_of_memory_error_array_size()); 653 } else { 654 THROW_OOP(Universe::out_of_memory_error_retry()); 655 } 656 } else if (length < 0) { 657 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length)); 658 } 659 } 660 661 // Replace the last '+' char with '/'. 662 static char* convert_hidden_name_to_java(Symbol* name) { 663 size_t name_len = name->utf8_length(); 664 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1); 665 name->as_klass_external_name(result, (int)name_len + 1); 666 for (int index = (int)name_len; index > 0; index--) { 667 if (result[index] == '+') { 668 result[index] = JVM_SIGNATURE_SLASH; 669 break; 670 } 671 } 672 return result; 673 } 674 675 // In product mode, this function doesn't have virtual function calls so 676 // there might be some performance advantage to handling InstanceKlass here. 677 const char* Klass::external_name() const { 678 if (is_instance_klass()) { 679 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this); 680 if (ik->is_hidden()) { 681 char* result = convert_hidden_name_to_java(name()); 682 return result; 683 } 684 } else if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) { 685 char* result = convert_hidden_name_to_java(name()); 686 return result; 687 } 688 if (name() == NULL) return "<unknown>"; 689 return name()->as_klass_external_name(); 690 } 691 692 const char* Klass::signature_name() const { 693 if (name() == NULL) return "<unknown>"; 694 if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) { 695 size_t name_len = name()->utf8_length(); 696 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1); 697 name()->as_C_string(result, (int)name_len + 1); 698 for (int index = (int)name_len; index > 0; index--) { 699 if (result[index] == '+') { 700 result[index] = JVM_SIGNATURE_DOT; 701 break; 702 } 703 } 704 return result; 705 } 706 return name()->as_C_string(); 707 } 708 709 const char* Klass::external_kind() const { 710 if (is_interface()) return "interface"; 711 if (is_abstract()) return "abstract class"; 712 return "class"; 713 } 714 715 int Klass::atomic_incr_biased_lock_revocation_count() { 716 return (int) Atomic::add(&_biased_lock_revocation_count, 1); 717 } 718 719 // Unless overridden, jvmti_class_status has no flags set. 720 jint Klass::jvmti_class_status() const { 721 return 0; 722 } 723 724 725 // Printing 726 727 void Klass::print_on(outputStream* st) const { 728 ResourceMark rm; 729 // print title 730 st->print("%s", internal_name()); 731 print_address_on(st); 732 st->cr(); 733 } 734 735 #define BULLET " - " 736 737 // Caller needs ResourceMark 738 void Klass::oop_print_on(oop obj, outputStream* st) { 739 // print title 740 st->print_cr("%s ", internal_name()); 741 obj->print_address_on(st); 742 743 if (WizardMode) { 744 // print header 745 obj->mark().print_on(st); 746 st->cr(); 747 st->print(BULLET"prototype_header: " INTPTR_FORMAT, _prototype_header.value()); 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() != NULL) { 775 guarantee(super()->is_klass(), "should be klass"); 776 } 777 if (secondary_super_cache() != NULL) { 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 != NULL) { 784 guarantee(ko->is_klass(), "should be klass"); 785 } 786 } 787 788 if (java_mirror_no_keepalive() != NULL) { 789 guarantee(oopDesc::is_oop(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 == NULL) { 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 != NULL, "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 == NULL) { 925 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader); 926 if (cl_name_and_id != NULL) { 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 == NULL) { 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 }