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 "utilities/macros.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 assert_locked_or_safepoint(Compile_lock); 417 debug_only(verify();) 418 // add ourselves to superklass' subklass list 419 InstanceKlass* super = superklass(); 420 if (super == NULL) return; // special case: class Object 421 assert((!super->is_interface() // interfaces cannot be supers 422 && (super->superklass() == NULL || !is_interface())), 423 "an interface can only be a subklass of Object"); 424 425 // Make sure there is no stale subklass head 426 super->clean_subklass(); 427 428 for (;;) { 429 Klass* prev_first_subklass = Atomic::load_acquire(&_super->_subklass); 430 if (prev_first_subklass != NULL) { 431 // set our sibling to be the superklass' previous first subklass 432 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses"); 433 set_next_sibling(prev_first_subklass); 434 } 435 // Note that the prev_first_subklass is always alive, meaning no sibling_next links 436 // are ever created to not alive klasses. This is an important invariant of the lock-free 437 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list. 438 if (Atomic::cmpxchg(&super->_subklass, prev_first_subklass, this) == prev_first_subklass) { 439 return; 440 } 441 } 442 debug_only(verify();) 443 } 444 445 void Klass::clean_subklass() { 446 for (;;) { 447 // Need load_acquire, due to contending with concurrent inserts 448 Klass* subklass = Atomic::load_acquire(&_subklass); 449 if (subklass == NULL || subklass->is_loader_alive()) { 450 return; 451 } 452 // Try to fix _subklass until it points at something not dead. 453 Atomic::cmpxchg(&_subklass, subklass, subklass->next_sibling()); 454 } 455 } 456 457 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) { 458 if (!ClassUnloading || !unloading_occurred) { 459 return; 460 } 461 462 Klass* root = SystemDictionary::Object_klass(); 463 Stack<Klass*, mtGC> stack; 464 465 stack.push(root); 466 while (!stack.is_empty()) { 467 Klass* current = stack.pop(); 468 469 assert(current->is_loader_alive(), "just checking, this should be live"); 470 471 // Find and set the first alive subklass 472 Klass* sub = current->subklass(true); 473 current->clean_subklass(); 474 if (sub != NULL) { 475 stack.push(sub); 476 } 477 478 // Find and set the first alive sibling 479 Klass* sibling = current->next_sibling(true); 480 current->set_next_sibling(sibling); 481 if (sibling != NULL) { 482 stack.push(sibling); 483 } 484 485 // Clean the implementors list and method data. 486 if (clean_alive_klasses && current->is_instance_klass()) { 487 InstanceKlass* ik = InstanceKlass::cast(current); 488 ik->clean_weak_instanceklass_links(); 489 490 // JVMTI RedefineClasses creates previous versions that are not in 491 // the class hierarchy, so process them here. 492 while ((ik = ik->previous_versions()) != NULL) { 493 ik->clean_weak_instanceklass_links(); 494 } 495 } 496 } 497 } 498 499 void Klass::metaspace_pointers_do(MetaspaceClosure* it) { 500 if (log_is_enabled(Trace, cds)) { 501 ResourceMark rm; 502 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name()); 503 } 504 505 it->push(&_name); 506 it->push(&_secondary_super_cache); 507 it->push(&_secondary_supers); 508 for (int i = 0; i < _primary_super_limit; i++) { 509 it->push(&_primary_supers[i]); 510 } 511 it->push(&_super); 512 it->push((Klass**)&_subklass); 513 it->push((Klass**)&_next_sibling); 514 it->push(&_next_link); 515 516 vtableEntry* vt = start_of_vtable(); 517 for (int i=0; i<vtable_length(); i++) { 518 it->push(vt[i].method_addr()); 519 } 520 } 521 522 void Klass::remove_unshareable_info() { 523 assert (Arguments::is_dumping_archive(), 524 "only called during CDS dump time"); 525 JFR_ONLY(REMOVE_ID(this);) 526 if (log_is_enabled(Trace, cds, unshareable)) { 527 ResourceMark rm; 528 log_trace(cds, unshareable)("remove: %s", external_name()); 529 } 530 531 set_subklass(NULL); 532 set_next_sibling(NULL); 533 set_next_link(NULL); 534 535 // Null out class_loader_data because we don't share that yet. 536 set_class_loader_data(NULL); 537 set_is_shared(); 538 } 539 540 void Klass::remove_java_mirror() { 541 Arguments::assert_is_dumping_archive(); 542 if (log_is_enabled(Trace, cds, unshareable)) { 543 ResourceMark rm; 544 log_trace(cds, unshareable)("remove java_mirror: %s", external_name()); 545 } 546 // Just null out the mirror. The class_loader_data() no longer exists. 547 _java_mirror = NULL; 548 } 549 550 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 551 assert(is_klass(), "ensure C++ vtable is restored"); 552 assert(is_shared(), "must be set"); 553 JFR_ONLY(RESTORE_ID(this);) 554 if (log_is_enabled(Trace, cds, unshareable)) { 555 ResourceMark rm; 556 log_trace(cds, unshareable)("restore: %s", external_name()); 557 } 558 559 // If an exception happened during CDS restore, some of these fields may already be 560 // set. We leave the class on the CLD list, even if incomplete so that we don't 561 // modify the CLD list outside a safepoint. 562 if (class_loader_data() == NULL) { 563 // Restore class_loader_data to the null class loader data 564 set_class_loader_data(loader_data); 565 566 // Add to null class loader list first before creating the mirror 567 // (same order as class file parsing) 568 loader_data->add_class(this); 569 } 570 571 Handle loader(THREAD, loader_data->class_loader()); 572 ModuleEntry* module_entry = NULL; 573 Klass* k = this; 574 if (k->is_objArray_klass()) { 575 k = ObjArrayKlass::cast(k)->bottom_klass(); 576 } 577 // Obtain klass' module. 578 if (k->is_instance_klass()) { 579 InstanceKlass* ik = (InstanceKlass*) k; 580 module_entry = ik->module(); 581 } else { 582 module_entry = ModuleEntryTable::javabase_moduleEntry(); 583 } 584 // Obtain java.lang.Module, if available 585 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL)); 586 587 if (this->has_raw_archived_mirror()) { 588 ResourceMark rm; 589 log_debug(cds, mirror)("%s has raw archived mirror", external_name()); 590 if (HeapShared::open_archive_heap_region_mapped()) { 591 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle, 592 protection_domain, 593 CHECK); 594 if (present) { 595 return; 596 } 597 } 598 599 // No archived mirror data 600 log_debug(cds, mirror)("No archived mirror data for %s", external_name()); 601 _java_mirror = NULL; 602 this->clear_has_raw_archived_mirror(); 603 } 604 605 // Only recreate it if not present. A previous attempt to restore may have 606 // gotten an OOM later but keep the mirror if it was created. 607 if (java_mirror() == NULL) { 608 log_trace(cds, mirror)("Recreate mirror for %s", external_name()); 609 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, Handle(), CHECK); 610 } 611 } 612 613 #if INCLUDE_CDS_JAVA_HEAP 614 // Used at CDS dump time to access the archived mirror. No GC barrier. 615 oop Klass::archived_java_mirror_raw() { 616 assert(has_raw_archived_mirror(), "must have raw archived mirror"); 617 return CompressedOops::decode(_archived_mirror); 618 } 619 620 narrowOop Klass::archived_java_mirror_raw_narrow() { 621 assert(has_raw_archived_mirror(), "must have raw archived mirror"); 622 return _archived_mirror; 623 } 624 625 // No GC barrier 626 void Klass::set_archived_java_mirror_raw(oop m) { 627 assert(DumpSharedSpaces, "called only during runtime"); 628 _archived_mirror = CompressedOops::encode(m); 629 } 630 #endif // INCLUDE_CDS_JAVA_HEAP 631 632 Klass* Klass::array_klass_or_null(int rank) { 633 EXCEPTION_MARK; 634 // No exception can be thrown by array_klass_impl when called with or_null == true. 635 // (In anycase, the execption mark will fail if it do so) 636 return array_klass_impl(true, rank, THREAD); 637 } 638 639 640 Klass* Klass::array_klass_or_null() { 641 EXCEPTION_MARK; 642 // No exception can be thrown by array_klass_impl when called with or_null == true. 643 // (In anycase, the execption mark will fail if it do so) 644 return array_klass_impl(true, THREAD); 645 } 646 647 648 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) { 649 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass"); 650 return NULL; 651 } 652 653 654 Klass* Klass::array_klass_impl(bool or_null, TRAPS) { 655 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass"); 656 return NULL; 657 } 658 659 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) { 660 if (length > max_length) { 661 if (!THREAD->in_retryable_allocation()) { 662 report_java_out_of_memory("Requested array size exceeds VM limit"); 663 JvmtiExport::post_array_size_exhausted(); 664 THROW_OOP(Universe::out_of_memory_error_array_size()); 665 } else { 666 THROW_OOP(Universe::out_of_memory_error_retry()); 667 } 668 } else if (length < 0) { 669 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length)); 670 } 671 } 672 673 // In product mode, this function doesn't have virtual function calls so 674 // there might be some performance advantage to handling InstanceKlass here. 675 const char* Klass::external_name() const { 676 if (is_instance_klass()) { 677 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this); 678 if (ik->is_unsafe_anonymous()) { 679 char addr_buf[20]; 680 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik)); 681 size_t addr_len = strlen(addr_buf); 682 size_t name_len = name()->utf8_length(); 683 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1); 684 name()->as_klass_external_name(result, (int) name_len + 1); 685 assert(strlen(result) == name_len, ""); 686 strcpy(result + name_len, addr_buf); 687 assert(strlen(result) == name_len + addr_len, ""); 688 return result; 689 690 } else if (ik->is_hidden()) { 691 // Replace the last '+' char with '/'. 692 size_t name_len = name()->utf8_length(); 693 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1); 694 name()->as_klass_external_name(result, (int)name_len + 1); 695 for (int index = (int)name_len; index > 0; index--) { 696 if (result[index] == '+') { 697 result[index] = '/'; 698 break; 699 } 700 } 701 return result; 702 } 703 } 704 if (name() == NULL) return "<unknown>"; 705 return name()->as_klass_external_name(); 706 } 707 708 const char* Klass::signature_name() const { 709 if (name() == NULL) return "<unknown>"; 710 return name()->as_C_string(); 711 } 712 713 const char* Klass::external_kind() const { 714 if (is_interface()) return "interface"; 715 if (is_abstract()) return "abstract class"; 716 return "class"; 717 } 718 719 // Unless overridden, modifier_flags is 0. 720 jint Klass::compute_modifier_flags(TRAPS) const { 721 return 0; 722 } 723 724 int Klass::atomic_incr_biased_lock_revocation_count() { 725 return (int) Atomic::add(&_biased_lock_revocation_count, 1); 726 } 727 728 // Unless overridden, jvmti_class_status has no flags set. 729 jint Klass::jvmti_class_status() const { 730 return 0; 731 } 732 733 734 // Printing 735 736 void Klass::print_on(outputStream* st) const { 737 ResourceMark rm; 738 // print title 739 st->print("%s", internal_name()); 740 print_address_on(st); 741 st->cr(); 742 } 743 744 #define BULLET " - " 745 746 void Klass::oop_print_on(oop obj, outputStream* st) { 747 // print title 748 st->print_cr("%s ", internal_name()); 749 obj->print_address_on(st); 750 751 if (WizardMode) { 752 // print header 753 obj->mark().print_on(st); 754 st->cr(); 755 st->print(BULLET"prototype_header: " INTPTR_FORMAT, _prototype_header.value()); 756 st->cr(); 757 } 758 759 // print class 760 st->print(BULLET"klass: "); 761 obj->klass()->print_value_on(st); 762 st->cr(); 763 } 764 765 void Klass::oop_print_value_on(oop obj, outputStream* st) { 766 // print title 767 ResourceMark rm; // Cannot print in debug mode without this 768 st->print("%s", internal_name()); 769 obj->print_address_on(st); 770 } 771 772 #if INCLUDE_SERVICES 773 // Size Statistics 774 void Klass::collect_statistics(KlassSizeStats *sz) const { 775 sz->_klass_bytes = sz->count(this); 776 sz->_mirror_bytes = sz->count(java_mirror_no_keepalive()); 777 sz->_secondary_supers_bytes = sz->count_array(secondary_supers()); 778 779 sz->_ro_bytes += sz->_secondary_supers_bytes; 780 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes; 781 } 782 #endif // INCLUDE_SERVICES 783 784 // Verification 785 786 void Klass::verify_on(outputStream* st) { 787 788 // This can be expensive, but it is worth checking that this klass is actually 789 // in the CLD graph but not in production. 790 assert(Metaspace::contains((address)this), "Should be"); 791 792 guarantee(this->is_klass(),"should be klass"); 793 794 if (super() != NULL) { 795 guarantee(super()->is_klass(), "should be klass"); 796 } 797 if (secondary_super_cache() != NULL) { 798 Klass* ko = secondary_super_cache(); 799 guarantee(ko->is_klass(), "should be klass"); 800 } 801 for ( uint i = 0; i < primary_super_limit(); i++ ) { 802 Klass* ko = _primary_supers[i]; 803 if (ko != NULL) { 804 guarantee(ko->is_klass(), "should be klass"); 805 } 806 } 807 808 if (java_mirror_no_keepalive() != NULL) { 809 guarantee(oopDesc::is_oop(java_mirror_no_keepalive()), "should be instance"); 810 } 811 } 812 813 void Klass::oop_verify_on(oop obj, outputStream* st) { 814 guarantee(oopDesc::is_oop(obj), "should be oop"); 815 guarantee(obj->klass()->is_klass(), "klass field is not a klass"); 816 } 817 818 bool Klass::is_valid(Klass* k) { 819 if (!is_aligned(k, sizeof(MetaWord))) return false; 820 if ((size_t)k < os::min_page_size()) return false; 821 822 if (!os::is_readable_range(k, k + 1)) return false; 823 if (!Metaspace::contains(k)) return false; 824 825 if (!Symbol::is_valid(k->name())) return false; 826 return ClassLoaderDataGraph::is_valid(k->class_loader_data()); 827 } 828 829 Method* Klass::method_at_vtable(int index) { 830 #ifndef PRODUCT 831 assert(index >= 0, "valid vtable index"); 832 if (DebugVtables) { 833 verify_vtable_index(index); 834 } 835 #endif 836 return start_of_vtable()[index].method(); 837 } 838 839 840 #ifndef PRODUCT 841 842 bool Klass::verify_vtable_index(int i) { 843 int limit = vtable_length()/vtableEntry::size(); 844 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit); 845 return true; 846 } 847 848 #endif // PRODUCT 849 850 // Caller needs ResourceMark 851 // joint_in_module_of_loader provides an optimization if 2 classes are in 852 // the same module to succinctly print out relevant information about their 853 // module name and class loader's name_and_id for error messages. 854 // Format: 855 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2> 856 // are in module <module-name>[@<version>] 857 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 858 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const { 859 assert(module() == class2->module(), "classes do not have the same module"); 860 const char* class1_name = external_name(); 861 size_t len = strlen(class1_name) + 1; 862 863 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader); 864 len += strlen(class2_description); 865 866 len += strlen(" and "); 867 868 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 869 870 // Just return the FQN if error when allocating string 871 if (joint_description == NULL) { 872 return class1_name; 873 } 874 875 jio_snprintf(joint_description, len, "%s and %s", 876 class1_name, 877 class2_description); 878 879 return joint_description; 880 } 881 882 // Caller needs ResourceMark 883 // class_in_module_of_loader provides a standard way to include 884 // relevant information about a class, such as its module name as 885 // well as its class loader's name_and_id, in error messages and logging. 886 // Format: 887 // <fully-qualified-external-class-name> is in module <module-name>[@<version>] 888 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 889 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const { 890 // 1. fully qualified external name of class 891 const char* klass_name = external_name(); 892 size_t len = strlen(klass_name) + 1; 893 894 // 2. module name + @version 895 const char* module_name = ""; 896 const char* version = ""; 897 bool has_version = false; 898 bool module_is_named = false; 899 const char* module_name_phrase = ""; 900 const Klass* bottom_klass = is_objArray_klass() ? 901 ObjArrayKlass::cast(this)->bottom_klass() : this; 902 if (bottom_klass->is_instance_klass()) { 903 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module(); 904 if (module->is_named()) { 905 module_is_named = true; 906 module_name_phrase = "module "; 907 module_name = module->name()->as_C_string(); 908 len += strlen(module_name); 909 // Use version if exists and is not a jdk module 910 if (module->should_show_version()) { 911 has_version = true; 912 version = module->version()->as_C_string(); 913 // Include stlen(version) + 1 for the "@" 914 len += strlen(version) + 1; 915 } 916 } else { 917 module_name = UNNAMED_MODULE; 918 len += UNNAMED_MODULE_LEN; 919 } 920 } else { 921 // klass is an array of primitives, module is java.base 922 module_is_named = true; 923 module_name_phrase = "module "; 924 module_name = JAVA_BASE_NAME; 925 len += JAVA_BASE_NAME_LEN; 926 } 927 928 // 3. class loader's name_and_id 929 ClassLoaderData* cld = class_loader_data(); 930 assert(cld != NULL, "class_loader_data should not be null"); 931 const char* loader_name_and_id = cld->loader_name_and_id(); 932 len += strlen(loader_name_and_id); 933 934 // 4. include parent loader information 935 const char* parent_loader_phrase = ""; 936 const char* parent_loader_name_and_id = ""; 937 if (include_parent_loader && 938 !cld->is_builtin_class_loader_data()) { 939 oop parent_loader = java_lang_ClassLoader::parent(class_loader()); 940 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data_or_null(parent_loader); 941 // The parent loader's ClassLoaderData could be null if it is 942 // a delegating class loader that has never defined a class. 943 // In this case the loader's name must be obtained via the parent loader's oop. 944 if (parent_cld == NULL) { 945 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader); 946 if (cl_name_and_id != NULL) { 947 parent_loader_name_and_id = java_lang_String::as_utf8_string(cl_name_and_id); 948 } 949 } else { 950 parent_loader_name_and_id = parent_cld->loader_name_and_id(); 951 } 952 parent_loader_phrase = ", parent loader "; 953 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id); 954 } 955 956 // Start to construct final full class description string 957 len += ((use_are) ? strlen(" are in ") : strlen(" is in ")); 958 len += strlen(module_name_phrase) + strlen(" of loader "); 959 960 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 961 962 // Just return the FQN if error when allocating string 963 if (class_description == NULL) { 964 return klass_name; 965 } 966 967 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s", 968 klass_name, 969 (use_are) ? "are" : "is", 970 module_name_phrase, 971 module_name, 972 (has_version) ? "@" : "", 973 (has_version) ? version : "", 974 loader_name_and_id, 975 parent_loader_phrase, 976 parent_loader_name_and_id); 977 978 return class_description; 979 }