1 /* 2 * Copyright (c) 1997, 2019, 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/heapInspection.hpp" 36 #include "memory/heapShared.hpp" 37 #include "memory/metadataFactory.hpp" 38 #include "memory/metaspaceClosure.hpp" 39 #include "memory/metaspaceShared.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 "runtime/atomic.hpp" 49 #include "runtime/handles.inline.hpp" 50 #include "runtime/orderAccess.hpp" 51 #include "utilities/macros.hpp" 52 #include "utilities/stack.inline.hpp" 53 54 void Klass::set_java_mirror(Handle m) { 55 assert(!m.is_null(), "New mirror should never be null."); 56 assert(_java_mirror.resolve() == NULL, "should only be used to initialize mirror"); 57 _java_mirror = class_loader_data()->add_handle(m); 58 } 59 60 oop Klass::java_mirror_no_keepalive() const { 61 return _java_mirror.peek(); 62 } 63 64 bool Klass::is_cloneable() const { 65 return _access_flags.is_cloneable_fast() || 66 is_subtype_of(SystemDictionary::Cloneable_klass()); 67 } 68 69 void Klass::set_is_cloneable() { 70 if (name() == vmSymbols::java_lang_invoke_MemberName()) { 71 assert(is_final(), "no subclasses allowed"); 72 // MemberName cloning should not be intrinsified and always happen in JVM_Clone. 73 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) { 74 // Reference cloning should not be intrinsified and always happen in JVM_Clone. 75 } else { 76 _access_flags.set_is_cloneable_fast(); 77 } 78 } 79 80 void Klass::set_name(Symbol* n) { 81 _name = n; 82 if (_name != NULL) _name->increment_refcount(); 83 } 84 85 bool Klass::is_subclass_of(const Klass* k) const { 86 // Run up the super chain and check 87 if (this == k) return true; 88 89 Klass* t = const_cast<Klass*>(this)->super(); 90 91 while (t != NULL) { 92 if (t == k) return true; 93 t = t->super(); 94 } 95 return false; 96 } 97 98 bool Klass::search_secondary_supers(Klass* k) const { 99 // Put some extra logic here out-of-line, before the search proper. 100 // This cuts down the size of the inline method. 101 102 // This is necessary, since I am never in my own secondary_super list. 103 if (this == k) 104 return true; 105 // Scan the array-of-objects for a match 106 int cnt = secondary_supers()->length(); 107 for (int i = 0; i < cnt; i++) { 108 if (secondary_supers()->at(i) == k) { 109 ((Klass*)this)->set_secondary_super_cache(k); 110 return true; 111 } 112 } 113 return false; 114 } 115 116 // Return self, except for abstract classes with exactly 1 117 // implementor. Then return the 1 concrete implementation. 118 Klass *Klass::up_cast_abstract() { 119 Klass *r = this; 120 while( r->is_abstract() ) { // Receiver is abstract? 121 Klass *s = r->subklass(); // Check for exactly 1 subklass 122 if (s == NULL || s->next_sibling() != NULL) // Oops; wrong count; give up 123 return this; // Return 'this' as a no-progress flag 124 r = s; // Loop till find concrete class 125 } 126 return r; // Return the 1 concrete class 127 } 128 129 // Find LCA in class hierarchy 130 Klass *Klass::LCA( Klass *k2 ) { 131 Klass *k1 = this; 132 while( 1 ) { 133 if( k1->is_subtype_of(k2) ) return k2; 134 if( k2->is_subtype_of(k1) ) return k1; 135 k1 = k1->super(); 136 k2 = k2->super(); 137 } 138 } 139 140 141 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) { 142 ResourceMark rm(THREAD); 143 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError() 144 : vmSymbols::java_lang_InstantiationException(), external_name()); 145 } 146 147 148 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) { 149 ResourceMark rm(THREAD); 150 assert(s != NULL, "Throw NPE!"); 151 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), 152 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name())); 153 } 154 155 156 void Klass::initialize(TRAPS) { 157 ShouldNotReachHere(); 158 } 159 160 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 161 #ifdef ASSERT 162 tty->print_cr("Error: find_field called on a klass oop." 163 " Likely error: reflection method does not correctly" 164 " wrap return value in a mirror object."); 165 #endif 166 ShouldNotReachHere(); 167 return NULL; 168 } 169 170 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, 171 OverpassLookupMode overpass_mode, 172 PrivateLookupMode private_mode) const { 173 #ifdef ASSERT 174 tty->print_cr("Error: uncached_lookup_method called on a klass oop." 175 " Likely error: reflection method does not correctly" 176 " wrap return value in a mirror object."); 177 #endif 178 ShouldNotReachHere(); 179 return NULL; 180 } 181 182 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() { 183 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD); 184 } 185 186 // "Normal" instantiation is preceeded by a MetaspaceObj allocation 187 // which zeros out memory - calloc equivalent. 188 // The constructor is also used from CppVtableCloner, 189 // which doesn't zero out the memory before calling the constructor. 190 // Need to set the _java_mirror field explicitly to not hit an assert that the field 191 // should be NULL before setting it. 192 Klass::Klass(KlassID id) : _id(id), 193 _java_mirror(NULL), 194 _prototype_header(markWord::prototype()), 195 _shared_class_path_index(-1) { 196 CDS_ONLY(_shared_class_flags = 0;) 197 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;) 198 _primary_supers[0] = this; 199 set_super_check_offset(in_bytes(primary_supers_offset())); 200 } 201 202 jint Klass::array_layout_helper(BasicType etype) { 203 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype"); 204 // Note that T_ARRAY is not allowed here. 205 int hsize = arrayOopDesc::base_offset_in_bytes(etype); 206 int esize = type2aelembytes(etype); 207 bool isobj = (etype == T_OBJECT); 208 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value; 209 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize)); 210 211 assert(lh < (int)_lh_neutral_value, "must look like an array layout"); 212 assert(layout_helper_is_array(lh), "correct kind"); 213 assert(layout_helper_is_objArray(lh) == isobj, "correct kind"); 214 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind"); 215 assert(layout_helper_header_size(lh) == hsize, "correct decode"); 216 assert(layout_helper_element_type(lh) == etype, "correct decode"); 217 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode"); 218 219 return lh; 220 } 221 222 bool Klass::can_be_primary_super_slow() const { 223 if (super() == NULL) 224 return true; 225 else if (super()->super_depth() >= primary_super_limit()-1) 226 return false; 227 else 228 return true; 229 } 230 231 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) { 232 if (k == NULL) { 233 set_super(NULL); 234 _primary_supers[0] = this; 235 assert(super_depth() == 0, "Object must already be initialized properly"); 236 } else if (k != super() || k == SystemDictionary::Object_klass()) { 237 assert(super() == NULL || super() == SystemDictionary::Object_klass(), 238 "initialize this only once to a non-trivial value"); 239 set_super(k); 240 Klass* sup = k; 241 int sup_depth = sup->super_depth(); 242 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit()); 243 if (!can_be_primary_super_slow()) 244 my_depth = primary_super_limit(); 245 for (juint i = 0; i < my_depth; i++) { 246 _primary_supers[i] = sup->_primary_supers[i]; 247 } 248 Klass* *super_check_cell; 249 if (my_depth < primary_super_limit()) { 250 _primary_supers[my_depth] = this; 251 super_check_cell = &_primary_supers[my_depth]; 252 } else { 253 // Overflow of the primary_supers array forces me to be secondary. 254 super_check_cell = &_secondary_super_cache; 255 } 256 set_super_check_offset((address)super_check_cell - (address) this); 257 258 #ifdef ASSERT 259 { 260 juint j = super_depth(); 261 assert(j == my_depth, "computed accessor gets right answer"); 262 Klass* t = this; 263 while (!t->can_be_primary_super()) { 264 t = t->super(); 265 j = t->super_depth(); 266 } 267 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) { 268 assert(primary_super_of_depth(j1) == NULL, "super list padding"); 269 } 270 while (t != NULL) { 271 assert(primary_super_of_depth(j) == t, "super list initialization"); 272 t = t->super(); 273 --j; 274 } 275 assert(j == (juint)-1, "correct depth count"); 276 } 277 #endif 278 } 279 280 if (secondary_supers() == NULL) { 281 282 // Now compute the list of secondary supertypes. 283 // Secondaries can occasionally be on the super chain, 284 // if the inline "_primary_supers" array overflows. 285 int extras = 0; 286 Klass* p; 287 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 288 ++extras; 289 } 290 291 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below 292 293 // Compute the "real" non-extra secondaries. 294 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces); 295 if (secondaries == NULL) { 296 // secondary_supers set by compute_secondary_supers 297 return; 298 } 299 300 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras); 301 302 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 303 int i; // Scan for overflow primaries being duplicates of 2nd'arys 304 305 // This happens frequently for very deeply nested arrays: the 306 // primary superclass chain overflows into the secondary. The 307 // secondary list contains the element_klass's secondaries with 308 // an extra array dimension added. If the element_klass's 309 // secondary list already contains some primary overflows, they 310 // (with the extra level of array-ness) will collide with the 311 // normal primary superclass overflows. 312 for( i = 0; i < secondaries->length(); i++ ) { 313 if( secondaries->at(i) == p ) 314 break; 315 } 316 if( i < secondaries->length() ) 317 continue; // It's a dup, don't put it in 318 primaries->push(p); 319 } 320 // Combine the two arrays into a metadata object to pack the array. 321 // The primaries are added in the reverse order, then the secondaries. 322 int new_length = primaries->length() + secondaries->length(); 323 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>( 324 class_loader_data(), new_length, CHECK); 325 int fill_p = primaries->length(); 326 for (int j = 0; j < fill_p; j++) { 327 s2->at_put(j, primaries->pop()); // add primaries in reverse order. 328 } 329 for( int j = 0; j < secondaries->length(); j++ ) { 330 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end. 331 } 332 333 #ifdef ASSERT 334 // We must not copy any NULL placeholders left over from bootstrap. 335 for (int j = 0; j < s2->length(); j++) { 336 assert(s2->at(j) != NULL, "correct bootstrapping order"); 337 } 338 #endif 339 340 set_secondary_supers(s2); 341 } 342 } 343 344 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots, 345 Array<InstanceKlass*>* transitive_interfaces) { 346 assert(num_extra_slots == 0, "override for complex klasses"); 347 assert(transitive_interfaces == NULL, "sanity"); 348 set_secondary_supers(Universe::the_empty_klass_array()); 349 return NULL; 350 } 351 352 353 // superklass links 354 InstanceKlass* Klass::superklass() const { 355 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass"); 356 return _super == NULL ? NULL : InstanceKlass::cast(_super); 357 } 358 359 // subklass links. Used by the compiler (and vtable initialization) 360 // May be cleaned concurrently, so must use the Compile_lock. 361 // The log parameter is for clean_weak_klass_links to report unlinked classes. 362 Klass* Klass::subklass(bool log) const { 363 // Need load_acquire on the _subklass, because it races with inserts that 364 // publishes freshly initialized data. 365 for (Klass* chain = Atomic::load_acquire(&_subklass); 366 chain != NULL; 367 // Do not need load_acquire on _next_sibling, because inserts never 368 // create _next_sibling edges to dead data. 369 chain = Atomic::load(&chain->_next_sibling)) 370 { 371 if (chain->is_loader_alive()) { 372 return chain; 373 } else if (log) { 374 if (log_is_enabled(Trace, class, unload)) { 375 ResourceMark rm; 376 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name()); 377 } 378 } 379 } 380 return NULL; 381 } 382 383 Klass* Klass::next_sibling(bool log) const { 384 // Do not need load_acquire on _next_sibling, because inserts never 385 // create _next_sibling edges to dead data. 386 for (Klass* chain = Atomic::load(&_next_sibling); 387 chain != NULL; 388 chain = Atomic::load(&chain->_next_sibling)) { 389 // Only return alive klass, there may be stale klass 390 // in this chain if cleaned concurrently. 391 if (chain->is_loader_alive()) { 392 return chain; 393 } else if (log) { 394 if (log_is_enabled(Trace, class, unload)) { 395 ResourceMark rm; 396 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name()); 397 } 398 } 399 } 400 return NULL; 401 } 402 403 void Klass::set_subklass(Klass* s) { 404 assert(s != this, "sanity check"); 405 Atomic::release_store(&_subklass, s); 406 } 407 408 void Klass::set_next_sibling(Klass* s) { 409 assert(s != this, "sanity check"); 410 // Does not need release semantics. If used by cleanup, it will link to 411 // already safely published data, and if used by inserts, will be published 412 // safely using cmpxchg. 413 Atomic::store(s, &_next_sibling); 414 } 415 416 void Klass::append_to_sibling_list() { 417 assert_locked_or_safepoint(Compile_lock); 418 debug_only(verify();) 419 // add ourselves to superklass' subklass list 420 InstanceKlass* super = superklass(); 421 if (super == NULL) return; // special case: class Object 422 assert((!super->is_interface() // interfaces cannot be supers 423 && (super->superklass() == NULL || !is_interface())), 424 "an interface can only be a subklass of Object"); 425 426 // Make sure there is no stale subklass head 427 super->clean_subklass(); 428 429 for (;;) { 430 Klass* prev_first_subklass = Atomic::load_acquire(&_super->_subklass); 431 if (prev_first_subklass != NULL) { 432 // set our sibling to be the superklass' previous first subklass 433 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses"); 434 set_next_sibling(prev_first_subklass); 435 } 436 // Note that the prev_first_subklass is always alive, meaning no sibling_next links 437 // are ever created to not alive klasses. This is an important invariant of the lock-free 438 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list. 439 if (Atomic::cmpxchg(this, &super->_subklass, prev_first_subklass) == prev_first_subklass) { 440 return; 441 } 442 } 443 debug_only(verify();) 444 } 445 446 void Klass::clean_subklass() { 447 for (;;) { 448 // Need load_acquire, due to contending with concurrent inserts 449 Klass* subklass = Atomic::load_acquire(&_subklass); 450 if (subklass == NULL || subklass->is_loader_alive()) { 451 return; 452 } 453 // Try to fix _subklass until it points at something not dead. 454 Atomic::cmpxchg(subklass->next_sibling(), &_subklass, subklass); 455 } 456 } 457 458 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) { 459 if (!ClassUnloading || !unloading_occurred) { 460 return; 461 } 462 463 Klass* root = SystemDictionary::Object_klass(); 464 Stack<Klass*, mtGC> stack; 465 466 stack.push(root); 467 while (!stack.is_empty()) { 468 Klass* current = stack.pop(); 469 470 assert(current->is_loader_alive(), "just checking, this should be live"); 471 472 // Find and set the first alive subklass 473 Klass* sub = current->subklass(true); 474 current->clean_subklass(); 475 if (sub != NULL) { 476 stack.push(sub); 477 } 478 479 // Find and set the first alive sibling 480 Klass* sibling = current->next_sibling(true); 481 current->set_next_sibling(sibling); 482 if (sibling != NULL) { 483 stack.push(sibling); 484 } 485 486 // Clean the implementors list and method data. 487 if (clean_alive_klasses && current->is_instance_klass()) { 488 InstanceKlass* ik = InstanceKlass::cast(current); 489 ik->clean_weak_instanceklass_links(); 490 491 // JVMTI RedefineClasses creates previous versions that are not in 492 // the class hierarchy, so process them here. 493 while ((ik = ik->previous_versions()) != NULL) { 494 ik->clean_weak_instanceklass_links(); 495 } 496 } 497 } 498 } 499 500 void Klass::metaspace_pointers_do(MetaspaceClosure* it) { 501 if (log_is_enabled(Trace, cds)) { 502 ResourceMark rm; 503 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name()); 504 } 505 506 it->push(&_name); 507 it->push(&_secondary_super_cache); 508 it->push(&_secondary_supers); 509 for (int i = 0; i < _primary_super_limit; i++) { 510 it->push(&_primary_supers[i]); 511 } 512 it->push(&_super); 513 it->push((Klass**)&_subklass); 514 it->push((Klass**)&_next_sibling); 515 it->push(&_next_link); 516 517 vtableEntry* vt = start_of_vtable(); 518 for (int i=0; i<vtable_length(); i++) { 519 it->push(vt[i].method_addr()); 520 } 521 } 522 523 void Klass::remove_unshareable_info() { 524 assert (Arguments::is_dumping_archive(), 525 "only called during CDS dump time"); 526 JFR_ONLY(REMOVE_ID(this);) 527 if (log_is_enabled(Trace, cds, unshareable)) { 528 ResourceMark rm; 529 log_trace(cds, unshareable)("remove: %s", external_name()); 530 } 531 532 set_subklass(NULL); 533 set_next_sibling(NULL); 534 set_next_link(NULL); 535 536 // Null out class_loader_data because we don't share that yet. 537 set_class_loader_data(NULL); 538 set_is_shared(); 539 } 540 541 void Klass::remove_java_mirror() { 542 Arguments::assert_is_dumping_archive(); 543 if (log_is_enabled(Trace, cds, unshareable)) { 544 ResourceMark rm; 545 log_trace(cds, unshareable)("remove java_mirror: %s", external_name()); 546 } 547 // Just null out the mirror. The class_loader_data() no longer exists. 548 _java_mirror = NULL; 549 } 550 551 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 552 assert(is_klass(), "ensure C++ vtable is restored"); 553 assert(is_shared(), "must be set"); 554 JFR_ONLY(RESTORE_ID(this);) 555 if (log_is_enabled(Trace, cds, unshareable)) { 556 ResourceMark rm; 557 log_trace(cds, unshareable)("restore: %s", external_name()); 558 } 559 560 // If an exception happened during CDS restore, some of these fields may already be 561 // set. We leave the class on the CLD list, even if incomplete so that we don't 562 // modify the CLD list outside a safepoint. 563 if (class_loader_data() == NULL) { 564 // Restore class_loader_data to the null class loader data 565 set_class_loader_data(loader_data); 566 567 // Add to null class loader list first before creating the mirror 568 // (same order as class file parsing) 569 loader_data->add_class(this); 570 } 571 572 Handle loader(THREAD, loader_data->class_loader()); 573 ModuleEntry* module_entry = NULL; 574 Klass* k = this; 575 if (k->is_objArray_klass()) { 576 k = ObjArrayKlass::cast(k)->bottom_klass(); 577 } 578 // Obtain klass' module. 579 if (k->is_instance_klass()) { 580 InstanceKlass* ik = (InstanceKlass*) k; 581 module_entry = ik->module(); 582 } else { 583 module_entry = ModuleEntryTable::javabase_moduleEntry(); 584 } 585 // Obtain java.lang.Module, if available 586 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL)); 587 588 if (this->has_raw_archived_mirror()) { 589 ResourceMark rm; 590 log_debug(cds, mirror)("%s has raw archived mirror", external_name()); 591 if (HeapShared::open_archive_heap_region_mapped()) { 592 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle, 593 protection_domain, 594 CHECK); 595 if (present) { 596 return; 597 } 598 } 599 600 // No archived mirror data 601 log_debug(cds, mirror)("No archived mirror data for %s", external_name()); 602 _java_mirror = NULL; 603 this->clear_has_raw_archived_mirror(); 604 } 605 606 // Only recreate it if not present. A previous attempt to restore may have 607 // gotten an OOM later but keep the mirror if it was created. 608 if (java_mirror() == NULL) { 609 log_trace(cds, mirror)("Recreate mirror for %s", external_name()); 610 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK); 611 } 612 } 613 614 #if INCLUDE_CDS_JAVA_HEAP 615 // Used at CDS dump time to access the archived mirror. No GC barrier. 616 oop Klass::archived_java_mirror_raw() { 617 assert(has_raw_archived_mirror(), "must have raw archived mirror"); 618 return CompressedOops::decode(_archived_mirror); 619 } 620 621 narrowOop Klass::archived_java_mirror_raw_narrow() { 622 assert(has_raw_archived_mirror(), "must have raw archived mirror"); 623 return _archived_mirror; 624 } 625 626 // No GC barrier 627 void Klass::set_archived_java_mirror_raw(oop m) { 628 assert(DumpSharedSpaces, "called only during runtime"); 629 _archived_mirror = CompressedOops::encode(m); 630 } 631 #endif // INCLUDE_CDS_JAVA_HEAP 632 633 Klass* Klass::array_klass_or_null(int rank) { 634 EXCEPTION_MARK; 635 // No exception can be thrown by array_klass_impl when called with or_null == true. 636 // (In anycase, the execption mark will fail if it do so) 637 return array_klass_impl(true, rank, THREAD); 638 } 639 640 641 Klass* Klass::array_klass_or_null() { 642 EXCEPTION_MARK; 643 // No exception can be thrown by array_klass_impl when called with or_null == true. 644 // (In anycase, the execption mark will fail if it do so) 645 return array_klass_impl(true, THREAD); 646 } 647 648 649 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) { 650 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass"); 651 return NULL; 652 } 653 654 655 Klass* Klass::array_klass_impl(bool or_null, TRAPS) { 656 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass"); 657 return NULL; 658 } 659 660 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) { 661 if (length > max_length) { 662 if (!THREAD->in_retryable_allocation()) { 663 report_java_out_of_memory("Requested array size exceeds VM limit"); 664 JvmtiExport::post_array_size_exhausted(); 665 THROW_OOP(Universe::out_of_memory_error_array_size()); 666 } else { 667 THROW_OOP(Universe::out_of_memory_error_retry()); 668 } 669 } else if (length < 0) { 670 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length)); 671 } 672 } 673 674 // In product mode, this function doesn't have virtual function calls so 675 // there might be some performance advantage to handling InstanceKlass here. 676 const char* Klass::external_name() const { 677 if (is_instance_klass()) { 678 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this); 679 if (ik->is_unsafe_anonymous()) { 680 char addr_buf[20]; 681 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik)); 682 size_t addr_len = strlen(addr_buf); 683 size_t name_len = name()->utf8_length(); 684 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1); 685 name()->as_klass_external_name(result, (int) name_len + 1); 686 assert(strlen(result) == name_len, ""); 687 strcpy(result + name_len, addr_buf); 688 assert(strlen(result) == name_len + addr_len, ""); 689 return result; 690 } 691 } 692 if (name() == NULL) return "<unknown>"; 693 return name()->as_klass_external_name(); 694 } 695 696 const char* Klass::signature_name() const { 697 if (name() == NULL) return "<unknown>"; 698 return name()->as_C_string(); 699 } 700 701 const char* Klass::external_kind() const { 702 if (is_interface()) return "interface"; 703 if (is_abstract()) return "abstract class"; 704 return "class"; 705 } 706 707 // Unless overridden, modifier_flags is 0. 708 jint Klass::compute_modifier_flags(TRAPS) const { 709 return 0; 710 } 711 712 int Klass::atomic_incr_biased_lock_revocation_count() { 713 return (int) Atomic::add(1, &_biased_lock_revocation_count); 714 } 715 716 // Unless overridden, jvmti_class_status has no flags set. 717 jint Klass::jvmti_class_status() const { 718 return 0; 719 } 720 721 722 // Printing 723 724 void Klass::print_on(outputStream* st) const { 725 ResourceMark rm; 726 // print title 727 st->print("%s", internal_name()); 728 print_address_on(st); 729 st->cr(); 730 } 731 732 #define BULLET " - " 733 734 void Klass::oop_print_on(oop obj, outputStream* st) { 735 // print title 736 st->print_cr("%s ", internal_name()); 737 obj->print_address_on(st); 738 739 if (WizardMode) { 740 // print header 741 obj->mark().print_on(st); 742 st->cr(); 743 st->print(BULLET"prototype_header: " INTPTR_FORMAT, _prototype_header.value()); 744 st->cr(); 745 } 746 747 // print class 748 st->print(BULLET"klass: "); 749 obj->klass()->print_value_on(st); 750 st->cr(); 751 } 752 753 void Klass::oop_print_value_on(oop obj, outputStream* st) { 754 // print title 755 ResourceMark rm; // Cannot print in debug mode without this 756 st->print("%s", internal_name()); 757 obj->print_address_on(st); 758 } 759 760 #if INCLUDE_SERVICES 761 // Size Statistics 762 void Klass::collect_statistics(KlassSizeStats *sz) const { 763 sz->_klass_bytes = sz->count(this); 764 sz->_mirror_bytes = sz->count(java_mirror_no_keepalive()); 765 sz->_secondary_supers_bytes = sz->count_array(secondary_supers()); 766 767 sz->_ro_bytes += sz->_secondary_supers_bytes; 768 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes; 769 } 770 #endif // INCLUDE_SERVICES 771 772 // Verification 773 774 void Klass::verify_on(outputStream* st) { 775 776 // This can be expensive, but it is worth checking that this klass is actually 777 // in the CLD graph but not in production. 778 assert(Metaspace::contains((address)this), "Should be"); 779 780 guarantee(this->is_klass(),"should be klass"); 781 782 if (super() != NULL) { 783 guarantee(super()->is_klass(), "should be klass"); 784 } 785 if (secondary_super_cache() != NULL) { 786 Klass* ko = secondary_super_cache(); 787 guarantee(ko->is_klass(), "should be klass"); 788 } 789 for ( uint i = 0; i < primary_super_limit(); i++ ) { 790 Klass* ko = _primary_supers[i]; 791 if (ko != NULL) { 792 guarantee(ko->is_klass(), "should be klass"); 793 } 794 } 795 796 if (java_mirror_no_keepalive() != NULL) { 797 guarantee(oopDesc::is_oop(java_mirror_no_keepalive()), "should be instance"); 798 } 799 } 800 801 void Klass::oop_verify_on(oop obj, outputStream* st) { 802 guarantee(oopDesc::is_oop(obj), "should be oop"); 803 guarantee(obj->klass()->is_klass(), "klass field is not a klass"); 804 } 805 806 bool Klass::is_valid(Klass* k) { 807 if (!is_aligned(k, sizeof(MetaWord))) return false; 808 if ((size_t)k < os::min_page_size()) return false; 809 810 if (!os::is_readable_range(k, k + 1)) return false; 811 if (!Metaspace::contains(k)) return false; 812 813 if (!Symbol::is_valid(k->name())) return false; 814 return ClassLoaderDataGraph::is_valid(k->class_loader_data()); 815 } 816 817 Method* Klass::method_at_vtable(int index) { 818 #ifndef PRODUCT 819 assert(index >= 0, "valid vtable index"); 820 if (DebugVtables) { 821 verify_vtable_index(index); 822 } 823 #endif 824 return start_of_vtable()[index].method(); 825 } 826 827 828 #ifndef PRODUCT 829 830 bool Klass::verify_vtable_index(int i) { 831 int limit = vtable_length()/vtableEntry::size(); 832 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit); 833 return true; 834 } 835 836 #endif // PRODUCT 837 838 // Caller needs ResourceMark 839 // joint_in_module_of_loader provides an optimization if 2 classes are in 840 // the same module to succinctly print out relevant information about their 841 // module name and class loader's name_and_id for error messages. 842 // Format: 843 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2> 844 // are in module <module-name>[@<version>] 845 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 846 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const { 847 assert(module() == class2->module(), "classes do not have the same module"); 848 const char* class1_name = external_name(); 849 size_t len = strlen(class1_name) + 1; 850 851 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader); 852 len += strlen(class2_description); 853 854 len += strlen(" and "); 855 856 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 857 858 // Just return the FQN if error when allocating string 859 if (joint_description == NULL) { 860 return class1_name; 861 } 862 863 jio_snprintf(joint_description, len, "%s and %s", 864 class1_name, 865 class2_description); 866 867 return joint_description; 868 } 869 870 // Caller needs ResourceMark 871 // class_in_module_of_loader provides a standard way to include 872 // relevant information about a class, such as its module name as 873 // well as its class loader's name_and_id, in error messages and logging. 874 // Format: 875 // <fully-qualified-external-class-name> is in module <module-name>[@<version>] 876 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 877 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const { 878 // 1. fully qualified external name of class 879 const char* klass_name = external_name(); 880 size_t len = strlen(klass_name) + 1; 881 882 // 2. module name + @version 883 const char* module_name = ""; 884 const char* version = ""; 885 bool has_version = false; 886 bool module_is_named = false; 887 const char* module_name_phrase = ""; 888 const Klass* bottom_klass = is_objArray_klass() ? 889 ObjArrayKlass::cast(this)->bottom_klass() : this; 890 if (bottom_klass->is_instance_klass()) { 891 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module(); 892 if (module->is_named()) { 893 module_is_named = true; 894 module_name_phrase = "module "; 895 module_name = module->name()->as_C_string(); 896 len += strlen(module_name); 897 // Use version if exists and is not a jdk module 898 if (module->should_show_version()) { 899 has_version = true; 900 version = module->version()->as_C_string(); 901 // Include stlen(version) + 1 for the "@" 902 len += strlen(version) + 1; 903 } 904 } else { 905 module_name = UNNAMED_MODULE; 906 len += UNNAMED_MODULE_LEN; 907 } 908 } else { 909 // klass is an array of primitives, module is java.base 910 module_is_named = true; 911 module_name_phrase = "module "; 912 module_name = JAVA_BASE_NAME; 913 len += JAVA_BASE_NAME_LEN; 914 } 915 916 // 3. class loader's name_and_id 917 ClassLoaderData* cld = class_loader_data(); 918 assert(cld != NULL, "class_loader_data should not be null"); 919 const char* loader_name_and_id = cld->loader_name_and_id(); 920 len += strlen(loader_name_and_id); 921 922 // 4. include parent loader information 923 const char* parent_loader_phrase = ""; 924 const char* parent_loader_name_and_id = ""; 925 if (include_parent_loader && 926 !cld->is_builtin_class_loader_data()) { 927 oop parent_loader = java_lang_ClassLoader::parent(class_loader()); 928 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data_or_null(parent_loader); 929 // The parent loader's ClassLoaderData could be null if it is 930 // a delegating class loader that has never defined a class. 931 // In this case the loader's name must be obtained via the parent loader's oop. 932 if (parent_cld == NULL) { 933 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader); 934 if (cl_name_and_id != NULL) { 935 parent_loader_name_and_id = java_lang_String::as_utf8_string(cl_name_and_id); 936 } 937 } else { 938 parent_loader_name_and_id = parent_cld->loader_name_and_id(); 939 } 940 parent_loader_phrase = ", parent loader "; 941 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id); 942 } 943 944 // Start to construct final full class description string 945 len += ((use_are) ? strlen(" are in ") : strlen(" is in ")); 946 len += strlen(module_name_phrase) + strlen(" of loader "); 947 948 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 949 950 // Just return the FQN if error when allocating string 951 if (class_description == NULL) { 952 return klass_name; 953 } 954 955 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s", 956 klass_name, 957 (use_are) ? "are" : "is", 958 module_name_phrase, 959 module_name, 960 (has_version) ? "@" : "", 961 (has_version) ? version : "", 962 loader_name_and_id, 963 parent_loader_phrase, 964 parent_loader_name_and_id); 965 966 return class_description; 967 }