1 /* 2 * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/classLoaderData.inline.hpp" 27 #include "classfile/classLoaderDataGraph.inline.hpp" 28 #include "classfile/dictionary.hpp" 29 #include "classfile/javaClasses.hpp" 30 #include "classfile/moduleEntry.hpp" 31 #include "classfile/systemDictionary.hpp" 32 #include "classfile/vmSymbols.hpp" 33 #include "gc/shared/collectedHeap.inline.hpp" 34 #include "logging/log.hpp" 35 #include "memory/heapShared.hpp" 36 #include "memory/metadataFactory.hpp" 37 #include "memory/metaspaceClosure.hpp" 38 #include "memory/metaspaceShared.hpp" 39 #include "memory/oopFactory.hpp" 40 #include "memory/resourceArea.hpp" 41 #include "memory/universe.hpp" 42 #include "oops/compressedOops.inline.hpp" 43 #include "oops/instanceKlass.hpp" 44 #include "oops/klass.inline.hpp" 45 #include "oops/oop.inline.hpp" 46 #include "oops/oopHandle.inline.hpp" 47 #include "runtime/atomic.hpp" 48 #include "runtime/handles.inline.hpp" 49 #include "utilities/macros.hpp" 50 #include "utilities/powerOfTwo.hpp" 51 #include "utilities/stack.inline.hpp" 52 53 void Klass::set_java_mirror(Handle m) { 54 assert(!m.is_null(), "New mirror should never be null."); 55 assert(_java_mirror.resolve() == NULL, "should only be used to initialize mirror"); 56 _java_mirror = class_loader_data()->add_handle(m); 57 } 58 59 oop Klass::java_mirror_no_keepalive() const { 60 return _java_mirror.peek(); 61 } 62 63 bool Klass::is_cloneable() const { 64 return _access_flags.is_cloneable_fast() || 65 is_subtype_of(SystemDictionary::Cloneable_klass()); 66 } 67 68 void Klass::set_is_cloneable() { 69 if (name() == vmSymbols::java_lang_invoke_MemberName()) { 70 assert(is_final(), "no subclasses allowed"); 71 // MemberName cloning should not be intrinsified and always happen in JVM_Clone. 72 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) { 73 // Reference cloning should not be intrinsified and always happen in JVM_Clone. 74 } else { 75 _access_flags.set_is_cloneable_fast(); 76 } 77 } 78 79 void Klass::set_name(Symbol* n) { 80 _name = n; 81 if (_name != NULL) _name->increment_refcount(); 82 } 83 84 bool Klass::is_subclass_of(const Klass* k) const { 85 // Run up the super chain and check 86 if (this == k) return true; 87 88 Klass* t = const_cast<Klass*>(this)->super(); 89 90 while (t != NULL) { 91 if (t == k) return true; 92 t = t->super(); 93 } 94 return false; 95 } 96 97 bool Klass::search_secondary_supers(Klass* k) const { 98 // Put some extra logic here out-of-line, before the search proper. 99 // This cuts down the size of the inline method. 100 101 // This is necessary, since I am never in my own secondary_super list. 102 if (this == k) 103 return true; 104 // Scan the array-of-objects for a match 105 int cnt = secondary_supers()->length(); 106 for (int i = 0; i < cnt; i++) { 107 if (secondary_supers()->at(i) == k) { 108 ((Klass*)this)->set_secondary_super_cache(k); 109 return true; 110 } 111 } 112 return false; 113 } 114 115 // Return self, except for abstract classes with exactly 1 116 // implementor. Then return the 1 concrete implementation. 117 Klass *Klass::up_cast_abstract() { 118 Klass *r = this; 119 while( r->is_abstract() ) { // Receiver is abstract? 120 Klass *s = r->subklass(); // Check for exactly 1 subklass 121 if (s == NULL || s->next_sibling() != NULL) // Oops; wrong count; give up 122 return this; // Return 'this' as a no-progress flag 123 r = s; // Loop till find concrete class 124 } 125 return r; // Return the 1 concrete class 126 } 127 128 // Find LCA in class hierarchy 129 Klass *Klass::LCA( Klass *k2 ) { 130 Klass *k1 = this; 131 while( 1 ) { 132 if( k1->is_subtype_of(k2) ) return k2; 133 if( k2->is_subtype_of(k1) ) return k1; 134 k1 = k1->super(); 135 k2 = k2->super(); 136 } 137 } 138 139 140 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) { 141 ResourceMark rm(THREAD); 142 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError() 143 : vmSymbols::java_lang_InstantiationException(), external_name()); 144 } 145 146 147 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) { 148 ResourceMark rm(THREAD); 149 assert(s != NULL, "Throw NPE!"); 150 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), 151 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name())); 152 } 153 154 155 void Klass::initialize(TRAPS) { 156 ShouldNotReachHere(); 157 } 158 159 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 160 #ifdef ASSERT 161 tty->print_cr("Error: find_field called on a klass oop." 162 " Likely error: reflection method does not correctly" 163 " wrap return value in a mirror object."); 164 #endif 165 ShouldNotReachHere(); 166 return NULL; 167 } 168 169 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, 170 OverpassLookupMode overpass_mode, 171 PrivateLookupMode private_mode) const { 172 #ifdef ASSERT 173 tty->print_cr("Error: uncached_lookup_method called on a klass oop." 174 " Likely error: reflection method does not correctly" 175 " wrap return value in a mirror object."); 176 #endif 177 ShouldNotReachHere(); 178 return NULL; 179 } 180 181 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() { 182 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD); 183 } 184 185 // "Normal" instantiation is preceeded by a MetaspaceObj allocation 186 // which zeros out memory - calloc equivalent. 187 // The constructor is also used from CppVtableCloner, 188 // which doesn't zero out the memory before calling the constructor. 189 // Need to set the _java_mirror field explicitly to not hit an assert that the field 190 // should be NULL before setting it. 191 Klass::Klass(KlassID id) : _id(id), 192 _java_mirror(NULL), 193 _prototype_header(markWord::prototype()), 194 _shared_class_path_index(-1) { 195 CDS_ONLY(_shared_class_flags = 0;) 196 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;) 197 _primary_supers[0] = this; 198 set_super_check_offset(in_bytes(primary_supers_offset())); 199 } 200 201 jint Klass::array_layout_helper(BasicType etype) { 202 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype"); 203 // Note that T_ARRAY is not allowed here. 204 int hsize = arrayOopDesc::base_offset_in_bytes(etype); 205 int esize = type2aelembytes(etype); 206 bool isobj = (etype == T_OBJECT); 207 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value; 208 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize)); 209 210 assert(lh < (int)_lh_neutral_value, "must look like an array layout"); 211 assert(layout_helper_is_array(lh), "correct kind"); 212 assert(layout_helper_is_objArray(lh) == isobj, "correct kind"); 213 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind"); 214 assert(layout_helper_header_size(lh) == hsize, "correct decode"); 215 assert(layout_helper_element_type(lh) == etype, "correct decode"); 216 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode"); 217 218 return lh; 219 } 220 221 bool Klass::can_be_primary_super_slow() const { 222 if (super() == NULL) 223 return true; 224 else if (super()->super_depth() >= primary_super_limit()-1) 225 return false; 226 else 227 return true; 228 } 229 230 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) { 231 if (k == NULL) { 232 set_super(NULL); 233 _primary_supers[0] = this; 234 assert(super_depth() == 0, "Object must already be initialized properly"); 235 } else if (k != super() || k == SystemDictionary::Object_klass()) { 236 assert(super() == NULL || super() == SystemDictionary::Object_klass(), 237 "initialize this only once to a non-trivial value"); 238 set_super(k); 239 Klass* sup = k; 240 int sup_depth = sup->super_depth(); 241 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit()); 242 if (!can_be_primary_super_slow()) 243 my_depth = primary_super_limit(); 244 for (juint i = 0; i < my_depth; i++) { 245 _primary_supers[i] = sup->_primary_supers[i]; 246 } 247 Klass* *super_check_cell; 248 if (my_depth < primary_super_limit()) { 249 _primary_supers[my_depth] = this; 250 super_check_cell = &_primary_supers[my_depth]; 251 } else { 252 // Overflow of the primary_supers array forces me to be secondary. 253 super_check_cell = &_secondary_super_cache; 254 } 255 set_super_check_offset((address)super_check_cell - (address) this); 256 257 #ifdef ASSERT 258 { 259 juint j = super_depth(); 260 assert(j == my_depth, "computed accessor gets right answer"); 261 Klass* t = this; 262 while (!t->can_be_primary_super()) { 263 t = t->super(); 264 j = t->super_depth(); 265 } 266 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) { 267 assert(primary_super_of_depth(j1) == NULL, "super list padding"); 268 } 269 while (t != NULL) { 270 assert(primary_super_of_depth(j) == t, "super list initialization"); 271 t = t->super(); 272 --j; 273 } 274 assert(j == (juint)-1, "correct depth count"); 275 } 276 #endif 277 } 278 279 if (secondary_supers() == NULL) { 280 281 // Now compute the list of secondary supertypes. 282 // Secondaries can occasionally be on the super chain, 283 // if the inline "_primary_supers" array overflows. 284 int extras = 0; 285 Klass* p; 286 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 287 ++extras; 288 } 289 290 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below 291 292 // Compute the "real" non-extra secondaries. 293 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces); 294 if (secondaries == NULL) { 295 // secondary_supers set by compute_secondary_supers 296 return; 297 } 298 299 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras); 300 301 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 302 int i; // Scan for overflow primaries being duplicates of 2nd'arys 303 304 // This happens frequently for very deeply nested arrays: the 305 // primary superclass chain overflows into the secondary. The 306 // secondary list contains the element_klass's secondaries with 307 // an extra array dimension added. If the element_klass's 308 // secondary list already contains some primary overflows, they 309 // (with the extra level of array-ness) will collide with the 310 // normal primary superclass overflows. 311 for( i = 0; i < secondaries->length(); i++ ) { 312 if( secondaries->at(i) == p ) 313 break; 314 } 315 if( i < secondaries->length() ) 316 continue; // It's a dup, don't put it in 317 primaries->push(p); 318 } 319 // Combine the two arrays into a metadata object to pack the array. 320 // The primaries are added in the reverse order, then the secondaries. 321 int new_length = primaries->length() + secondaries->length(); 322 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>( 323 class_loader_data(), new_length, CHECK); 324 int fill_p = primaries->length(); 325 for (int j = 0; j < fill_p; j++) { 326 s2->at_put(j, primaries->pop()); // add primaries in reverse order. 327 } 328 for( int j = 0; j < secondaries->length(); j++ ) { 329 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end. 330 } 331 332 #ifdef ASSERT 333 // We must not copy any NULL placeholders left over from bootstrap. 334 for (int j = 0; j < s2->length(); j++) { 335 assert(s2->at(j) != NULL, "correct bootstrapping order"); 336 } 337 #endif 338 339 set_secondary_supers(s2); 340 } 341 } 342 343 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots, 344 Array<InstanceKlass*>* transitive_interfaces) { 345 assert(num_extra_slots == 0, "override for complex klasses"); 346 assert(transitive_interfaces == NULL, "sanity"); 347 set_secondary_supers(Universe::the_empty_klass_array()); 348 return NULL; 349 } 350 351 352 // superklass links 353 InstanceKlass* Klass::superklass() const { 354 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass"); 355 return _super == NULL ? NULL : InstanceKlass::cast(_super); 356 } 357 358 // subklass links. Used by the compiler (and vtable initialization) 359 // May be cleaned concurrently, so must use the Compile_lock. 360 // The log parameter is for clean_weak_klass_links to report unlinked classes. 361 Klass* Klass::subklass(bool log) const { 362 // Need load_acquire on the _subklass, because it races with inserts that 363 // publishes freshly initialized data. 364 for (Klass* chain = Atomic::load_acquire(&_subklass); 365 chain != NULL; 366 // Do not need load_acquire on _next_sibling, because inserts never 367 // create _next_sibling edges to dead data. 368 chain = Atomic::load(&chain->_next_sibling)) 369 { 370 if (chain->is_loader_alive()) { 371 return chain; 372 } else if (log) { 373 if (log_is_enabled(Trace, class, unload)) { 374 ResourceMark rm; 375 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name()); 376 } 377 } 378 } 379 return NULL; 380 } 381 382 Klass* Klass::next_sibling(bool log) const { 383 // Do not need load_acquire on _next_sibling, because inserts never 384 // create _next_sibling edges to dead data. 385 for (Klass* chain = Atomic::load(&_next_sibling); 386 chain != NULL; 387 chain = Atomic::load(&chain->_next_sibling)) { 388 // Only return alive klass, there may be stale klass 389 // in this chain if cleaned concurrently. 390 if (chain->is_loader_alive()) { 391 return chain; 392 } else if (log) { 393 if (log_is_enabled(Trace, class, unload)) { 394 ResourceMark rm; 395 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name()); 396 } 397 } 398 } 399 return NULL; 400 } 401 402 void Klass::set_subklass(Klass* s) { 403 assert(s != this, "sanity check"); 404 Atomic::release_store(&_subklass, s); 405 } 406 407 void Klass::set_next_sibling(Klass* s) { 408 assert(s != this, "sanity check"); 409 // Does not need release semantics. If used by cleanup, it will link to 410 // already safely published data, and if used by inserts, will be published 411 // safely using cmpxchg. 412 Atomic::store(&_next_sibling, s); 413 } 414 415 void Klass::append_to_sibling_list() { 416 if (Universe::is_fully_initialized()) { 417 assert_locked_or_safepoint(Compile_lock); 418 } 419 debug_only(verify();) 420 // add ourselves to superklass' subklass list 421 InstanceKlass* super = superklass(); 422 if (super == NULL) return; // special case: class Object 423 assert((!super->is_interface() // interfaces cannot be supers 424 && (super->superklass() == NULL || !is_interface())), 425 "an interface can only be a subklass of Object"); 426 427 // Make sure there is no stale subklass head 428 super->clean_subklass(); 429 430 for (;;) { 431 Klass* prev_first_subklass = Atomic::load_acquire(&_super->_subklass); 432 if (prev_first_subklass != NULL) { 433 // set our sibling to be the superklass' previous first subklass 434 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses"); 435 set_next_sibling(prev_first_subklass); 436 } 437 // Note that the prev_first_subklass is always alive, meaning no sibling_next links 438 // are ever created to not alive klasses. This is an important invariant of the lock-free 439 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list. 440 if (Atomic::cmpxchg(&super->_subklass, prev_first_subklass, this) == prev_first_subklass) { 441 return; 442 } 443 } 444 debug_only(verify();) 445 } 446 447 void Klass::clean_subklass() { 448 for (;;) { 449 // Need load_acquire, due to contending with concurrent inserts 450 Klass* subklass = Atomic::load_acquire(&_subklass); 451 if (subklass == NULL || subklass->is_loader_alive()) { 452 return; 453 } 454 // Try to fix _subklass until it points at something not dead. 455 Atomic::cmpxchg(&_subklass, subklass, subklass->next_sibling()); 456 } 457 } 458 459 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) { 460 if (!ClassUnloading || !unloading_occurred) { 461 return; 462 } 463 464 Klass* root = SystemDictionary::Object_klass(); 465 Stack<Klass*, mtGC> stack; 466 467 stack.push(root); 468 while (!stack.is_empty()) { 469 Klass* current = stack.pop(); 470 471 assert(current->is_loader_alive(), "just checking, this should be live"); 472 473 // Find and set the first alive subklass 474 Klass* sub = current->subklass(true); 475 current->clean_subklass(); 476 if (sub != NULL) { 477 stack.push(sub); 478 } 479 480 // Find and set the first alive sibling 481 Klass* sibling = current->next_sibling(true); 482 current->set_next_sibling(sibling); 483 if (sibling != NULL) { 484 stack.push(sibling); 485 } 486 487 // Clean the implementors list and method data. 488 if (clean_alive_klasses && current->is_instance_klass()) { 489 InstanceKlass* ik = InstanceKlass::cast(current); 490 ik->clean_weak_instanceklass_links(); 491 492 // JVMTI RedefineClasses creates previous versions that are not in 493 // the class hierarchy, so process them here. 494 while ((ik = ik->previous_versions()) != NULL) { 495 ik->clean_weak_instanceklass_links(); 496 } 497 } 498 } 499 } 500 501 void Klass::metaspace_pointers_do(MetaspaceClosure* it) { 502 if (log_is_enabled(Trace, cds)) { 503 ResourceMark rm; 504 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name()); 505 } 506 507 it->push(&_name); 508 it->push(&_secondary_super_cache); 509 it->push(&_secondary_supers); 510 for (int i = 0; i < _primary_super_limit; i++) { 511 it->push(&_primary_supers[i]); 512 } 513 it->push(&_super); 514 it->push((Klass**)&_subklass); 515 it->push((Klass**)&_next_sibling); 516 it->push(&_next_link); 517 518 vtableEntry* vt = start_of_vtable(); 519 for (int i=0; i<vtable_length(); i++) { 520 it->push(vt[i].method_addr()); 521 } 522 } 523 524 void Klass::remove_unshareable_info() { 525 assert (Arguments::is_dumping_archive(), 526 "only called during CDS dump time"); 527 JFR_ONLY(REMOVE_ID(this);) 528 if (log_is_enabled(Trace, cds, unshareable)) { 529 ResourceMark rm; 530 log_trace(cds, unshareable)("remove: %s", external_name()); 531 } 532 533 set_subklass(NULL); 534 set_next_sibling(NULL); 535 set_next_link(NULL); 536 537 // Null out class_loader_data because we don't share that yet. 538 set_class_loader_data(NULL); 539 set_is_shared(); 540 } 541 542 void Klass::remove_java_mirror() { 543 Arguments::assert_is_dumping_archive(); 544 if (log_is_enabled(Trace, cds, unshareable)) { 545 ResourceMark rm; 546 log_trace(cds, unshareable)("remove java_mirror: %s", external_name()); 547 } 548 // Just null out the mirror. The class_loader_data() no longer exists. 549 _java_mirror = NULL; 550 } 551 552 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 553 assert(is_klass(), "ensure C++ vtable is restored"); 554 assert(is_shared(), "must be set"); 555 JFR_ONLY(RESTORE_ID(this);) 556 if (log_is_enabled(Trace, cds, unshareable)) { 557 ResourceMark rm(THREAD); 558 log_trace(cds, unshareable)("restore: %s", external_name()); 559 } 560 561 // If an exception happened during CDS restore, some of these fields may already be 562 // set. We leave the class on the CLD list, even if incomplete so that we don't 563 // modify the CLD list outside a safepoint. 564 if (class_loader_data() == NULL) { 565 // Restore class_loader_data to the null class loader data 566 set_class_loader_data(loader_data); 567 568 // Add to null class loader list first before creating the mirror 569 // (same order as class file parsing) 570 loader_data->add_class(this); 571 } 572 573 Handle loader(THREAD, loader_data->class_loader()); 574 ModuleEntry* module_entry = NULL; 575 Klass* k = this; 576 if (k->is_objArray_klass()) { 577 k = ObjArrayKlass::cast(k)->bottom_klass(); 578 } 579 // Obtain klass' module. 580 if (k->is_instance_klass()) { 581 InstanceKlass* ik = (InstanceKlass*) k; 582 module_entry = ik->module(); 583 } else { 584 module_entry = ModuleEntryTable::javabase_moduleEntry(); 585 } 586 // Obtain java.lang.Module, if available 587 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL)); 588 589 if (this->has_raw_archived_mirror()) { 590 ResourceMark rm(THREAD); 591 log_debug(cds, mirror)("%s has raw archived mirror", external_name()); 592 if (HeapShared::open_archive_heap_region_mapped()) { 593 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle, 594 protection_domain, 595 CHECK); 596 if (present) { 597 return; 598 } 599 } 600 601 // No archived mirror data 602 log_debug(cds, mirror)("No archived mirror data for %s", external_name()); 603 _java_mirror = NULL; 604 this->clear_has_raw_archived_mirror(); 605 } 606 607 // Only recreate it if not present. A previous attempt to restore may have 608 // gotten an OOM later but keep the mirror if it was created. 609 if (java_mirror() == NULL) { 610 log_trace(cds, mirror)("Recreate mirror for %s", external_name()); 611 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK); 612 } 613 } 614 615 #if INCLUDE_CDS_JAVA_HEAP 616 // Used at CDS dump time to access the archived mirror. No GC barrier. 617 oop Klass::archived_java_mirror_raw() { 618 assert(has_raw_archived_mirror(), "must have raw archived mirror"); 619 return CompressedOops::decode(_archived_mirror); 620 } 621 622 narrowOop Klass::archived_java_mirror_raw_narrow() { 623 assert(has_raw_archived_mirror(), "must have raw archived mirror"); 624 return _archived_mirror; 625 } 626 627 // No GC barrier 628 void Klass::set_archived_java_mirror_raw(oop m) { 629 assert(DumpSharedSpaces, "called only during runtime"); 630 _archived_mirror = CompressedOops::encode(m); 631 } 632 #endif // INCLUDE_CDS_JAVA_HEAP 633 634 Klass* Klass::array_klass_or_null(int rank) { 635 EXCEPTION_MARK; 636 // No exception can be thrown by array_klass_impl when called with or_null == true. 637 // (In anycase, the execption mark will fail if it do so) 638 return array_klass_impl(true, rank, THREAD); 639 } 640 641 642 Klass* Klass::array_klass_or_null() { 643 EXCEPTION_MARK; 644 // No exception can be thrown by array_klass_impl when called with or_null == true. 645 // (In anycase, the execption mark will fail if it do so) 646 return array_klass_impl(true, THREAD); 647 } 648 649 650 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) { 651 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass"); 652 return NULL; 653 } 654 655 656 Klass* Klass::array_klass_impl(bool or_null, TRAPS) { 657 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass"); 658 return NULL; 659 } 660 661 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) { 662 if (length > max_length) { 663 if (!THREAD->in_retryable_allocation()) { 664 report_java_out_of_memory("Requested array size exceeds VM limit"); 665 JvmtiExport::post_array_size_exhausted(); 666 THROW_OOP(Universe::out_of_memory_error_array_size()); 667 } else { 668 THROW_OOP(Universe::out_of_memory_error_retry()); 669 } 670 } else if (length < 0) { 671 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length)); 672 } 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_unsafe_anonymous()) { 681 char addr_buf[20]; 682 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik)); 683 size_t addr_len = strlen(addr_buf); 684 size_t name_len = name()->utf8_length(); 685 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1); 686 name()->as_klass_external_name(result, (int) name_len + 1); 687 assert(strlen(result) == name_len, ""); 688 strcpy(result + name_len, addr_buf); 689 assert(strlen(result) == name_len + addr_len, ""); 690 return result; 691 } 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 return name()->as_C_string(); 700 } 701 702 const char* Klass::external_kind() const { 703 if (is_interface()) return "interface"; 704 if (is_abstract()) return "abstract class"; 705 return "class"; 706 } 707 708 // Unless overridden, modifier_flags is 0. 709 jint Klass::compute_modifier_flags(TRAPS) const { 710 return 0; 711 } 712 713 int Klass::atomic_incr_biased_lock_revocation_count() { 714 return (int) Atomic::add(&_biased_lock_revocation_count, 1); 715 } 716 717 // Unless overridden, jvmti_class_status has no flags set. 718 jint Klass::jvmti_class_status() const { 719 return 0; 720 } 721 722 723 // Printing 724 725 void Klass::print_on(outputStream* st) const { 726 ResourceMark rm; 727 // print title 728 st->print("%s", internal_name()); 729 print_address_on(st); 730 st->cr(); 731 } 732 733 #define BULLET " - " 734 735 void Klass::oop_print_on(oop obj, outputStream* st) { 736 // print title 737 st->print_cr("%s ", internal_name()); 738 obj->print_address_on(st); 739 740 if (WizardMode) { 741 // print header 742 obj->mark().print_on(st); 743 st->cr(); 744 st->print(BULLET"prototype_header: " INTPTR_FORMAT, _prototype_header.value()); 745 st->cr(); 746 } 747 748 // print class 749 st->print(BULLET"klass: "); 750 obj->klass()->print_value_on(st); 751 st->cr(); 752 } 753 754 void Klass::oop_print_value_on(oop obj, outputStream* st) { 755 // print title 756 ResourceMark rm; // Cannot print in debug mode without this 757 st->print("%s", internal_name()); 758 obj->print_address_on(st); 759 } 760 761 // Verification 762 763 void Klass::verify_on(outputStream* st) { 764 765 // This can be expensive, but it is worth checking that this klass is actually 766 // in the CLD graph but not in production. 767 assert(Metaspace::contains((address)this), "Should be"); 768 769 guarantee(this->is_klass(),"should be klass"); 770 771 if (super() != NULL) { 772 guarantee(super()->is_klass(), "should be klass"); 773 } 774 if (secondary_super_cache() != NULL) { 775 Klass* ko = secondary_super_cache(); 776 guarantee(ko->is_klass(), "should be klass"); 777 } 778 for ( uint i = 0; i < primary_super_limit(); i++ ) { 779 Klass* ko = _primary_supers[i]; 780 if (ko != NULL) { 781 guarantee(ko->is_klass(), "should be klass"); 782 } 783 } 784 785 if (java_mirror_no_keepalive() != NULL) { 786 guarantee(oopDesc::is_oop(java_mirror_no_keepalive()), "should be instance"); 787 } 788 } 789 790 void Klass::oop_verify_on(oop obj, outputStream* st) { 791 guarantee(oopDesc::is_oop(obj), "should be oop"); 792 guarantee(obj->klass()->is_klass(), "klass field is not a klass"); 793 } 794 795 bool Klass::is_valid(Klass* k) { 796 if (!is_aligned(k, sizeof(MetaWord))) return false; 797 if ((size_t)k < os::min_page_size()) return false; 798 799 if (!os::is_readable_range(k, k + 1)) return false; 800 if (!Metaspace::contains(k)) return false; 801 802 if (!Symbol::is_valid(k->name())) return false; 803 return ClassLoaderDataGraph::is_valid(k->class_loader_data()); 804 } 805 806 Method* Klass::method_at_vtable(int index) { 807 #ifndef PRODUCT 808 assert(index >= 0, "valid vtable index"); 809 if (DebugVtables) { 810 verify_vtable_index(index); 811 } 812 #endif 813 return start_of_vtable()[index].method(); 814 } 815 816 817 #ifndef PRODUCT 818 819 bool Klass::verify_vtable_index(int i) { 820 int limit = vtable_length()/vtableEntry::size(); 821 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit); 822 return true; 823 } 824 825 #endif // PRODUCT 826 827 // Caller needs ResourceMark 828 // joint_in_module_of_loader provides an optimization if 2 classes are in 829 // the same module to succinctly print out relevant information about their 830 // module name and class loader's name_and_id for error messages. 831 // Format: 832 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2> 833 // are in module <module-name>[@<version>] 834 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 835 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const { 836 assert(module() == class2->module(), "classes do not have the same module"); 837 const char* class1_name = external_name(); 838 size_t len = strlen(class1_name) + 1; 839 840 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader); 841 len += strlen(class2_description); 842 843 len += strlen(" and "); 844 845 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 846 847 // Just return the FQN if error when allocating string 848 if (joint_description == NULL) { 849 return class1_name; 850 } 851 852 jio_snprintf(joint_description, len, "%s and %s", 853 class1_name, 854 class2_description); 855 856 return joint_description; 857 } 858 859 // Caller needs ResourceMark 860 // class_in_module_of_loader provides a standard way to include 861 // relevant information about a class, such as its module name as 862 // well as its class loader's name_and_id, in error messages and logging. 863 // Format: 864 // <fully-qualified-external-class-name> is in module <module-name>[@<version>] 865 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 866 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const { 867 // 1. fully qualified external name of class 868 const char* klass_name = external_name(); 869 size_t len = strlen(klass_name) + 1; 870 871 // 2. module name + @version 872 const char* module_name = ""; 873 const char* version = ""; 874 bool has_version = false; 875 bool module_is_named = false; 876 const char* module_name_phrase = ""; 877 const Klass* bottom_klass = is_objArray_klass() ? 878 ObjArrayKlass::cast(this)->bottom_klass() : this; 879 if (bottom_klass->is_instance_klass()) { 880 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module(); 881 if (module->is_named()) { 882 module_is_named = true; 883 module_name_phrase = "module "; 884 module_name = module->name()->as_C_string(); 885 len += strlen(module_name); 886 // Use version if exists and is not a jdk module 887 if (module->should_show_version()) { 888 has_version = true; 889 version = module->version()->as_C_string(); 890 // Include stlen(version) + 1 for the "@" 891 len += strlen(version) + 1; 892 } 893 } else { 894 module_name = UNNAMED_MODULE; 895 len += UNNAMED_MODULE_LEN; 896 } 897 } else { 898 // klass is an array of primitives, module is java.base 899 module_is_named = true; 900 module_name_phrase = "module "; 901 module_name = JAVA_BASE_NAME; 902 len += JAVA_BASE_NAME_LEN; 903 } 904 905 // 3. class loader's name_and_id 906 ClassLoaderData* cld = class_loader_data(); 907 assert(cld != NULL, "class_loader_data should not be null"); 908 const char* loader_name_and_id = cld->loader_name_and_id(); 909 len += strlen(loader_name_and_id); 910 911 // 4. include parent loader information 912 const char* parent_loader_phrase = ""; 913 const char* parent_loader_name_and_id = ""; 914 if (include_parent_loader && 915 !cld->is_builtin_class_loader_data()) { 916 oop parent_loader = java_lang_ClassLoader::parent(class_loader()); 917 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data_or_null(parent_loader); 918 // The parent loader's ClassLoaderData could be null if it is 919 // a delegating class loader that has never defined a class. 920 // In this case the loader's name must be obtained via the parent loader's oop. 921 if (parent_cld == NULL) { 922 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader); 923 if (cl_name_and_id != NULL) { 924 parent_loader_name_and_id = java_lang_String::as_utf8_string(cl_name_and_id); 925 } 926 } else { 927 parent_loader_name_and_id = parent_cld->loader_name_and_id(); 928 } 929 parent_loader_phrase = ", parent loader "; 930 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id); 931 } 932 933 // Start to construct final full class description string 934 len += ((use_are) ? strlen(" are in ") : strlen(" is in ")); 935 len += strlen(module_name_phrase) + strlen(" of loader "); 936 937 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 938 939 // Just return the FQN if error when allocating string 940 if (class_description == NULL) { 941 return klass_name; 942 } 943 944 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s", 945 klass_name, 946 (use_are) ? "are" : "is", 947 module_name_phrase, 948 module_name, 949 (has_version) ? "@" : "", 950 (has_version) ? version : "", 951 loader_name_and_id, 952 parent_loader_phrase, 953 parent_loader_name_and_id); 954 955 return class_description; 956 }