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() const { 61 return _java_mirror.resolve(); 62 } 63 64 oop Klass::java_mirror_no_keepalive() const { 65 return _java_mirror.peek(); 66 } 67 68 bool Klass::is_cloneable() const { 69 return _access_flags.is_cloneable_fast() || 70 is_subtype_of(SystemDictionary::Cloneable_klass()); 71 } 72 73 void Klass::set_is_cloneable() { 74 if (name() == vmSymbols::java_lang_invoke_MemberName()) { 75 assert(is_final(), "no subclasses allowed"); 76 // MemberName cloning should not be intrinsified and always happen in JVM_Clone. 77 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) { 78 // Reference cloning should not be intrinsified and always happen in JVM_Clone. 79 } else { 80 _access_flags.set_is_cloneable_fast(); 81 } 82 } 83 84 void Klass::set_name(Symbol* n) { 85 _name = n; 86 if (_name != NULL) _name->increment_refcount(); 87 } 88 89 bool Klass::is_subclass_of(const Klass* k) const { 90 // Run up the super chain and check 91 if (this == k) return true; 92 93 Klass* t = const_cast<Klass*>(this)->super(); 94 95 while (t != NULL) { 96 if (t == k) return true; 97 t = t->super(); 98 } 99 return false; 100 } 101 102 bool Klass::search_secondary_supers(Klass* k) const { 103 // Put some extra logic here out-of-line, before the search proper. 104 // This cuts down the size of the inline method. 105 106 // This is necessary, since I am never in my own secondary_super list. 107 if (this == k) 108 return true; 109 // Scan the array-of-objects for a match 110 int cnt = secondary_supers()->length(); 111 for (int i = 0; i < cnt; i++) { 112 if (secondary_supers()->at(i) == k) { 113 ((Klass*)this)->set_secondary_super_cache(k); 114 return true; 115 } 116 } 117 return false; 118 } 119 120 // Return self, except for abstract classes with exactly 1 121 // implementor. Then return the 1 concrete implementation. 122 Klass *Klass::up_cast_abstract() { 123 Klass *r = this; 124 while( r->is_abstract() ) { // Receiver is abstract? 125 Klass *s = r->subklass(); // Check for exactly 1 subklass 126 if (s == NULL || s->next_sibling() != NULL) // Oops; wrong count; give up 127 return this; // Return 'this' as a no-progress flag 128 r = s; // Loop till find concrete class 129 } 130 return r; // Return the 1 concrete class 131 } 132 133 // Find LCA in class hierarchy 134 Klass *Klass::LCA( Klass *k2 ) { 135 Klass *k1 = this; 136 while( 1 ) { 137 if( k1->is_subtype_of(k2) ) return k2; 138 if( k2->is_subtype_of(k1) ) return k1; 139 k1 = k1->super(); 140 k2 = k2->super(); 141 } 142 } 143 144 145 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) { 146 ResourceMark rm(THREAD); 147 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError() 148 : vmSymbols::java_lang_InstantiationException(), external_name()); 149 } 150 151 152 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) { 153 ResourceMark rm(THREAD); 154 assert(s != NULL, "Throw NPE!"); 155 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), 156 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name())); 157 } 158 159 160 void Klass::initialize(TRAPS) { 161 ShouldNotReachHere(); 162 } 163 164 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 165 #ifdef ASSERT 166 tty->print_cr("Error: find_field called on a klass oop." 167 " Likely error: reflection method does not correctly" 168 " wrap return value in a mirror object."); 169 #endif 170 ShouldNotReachHere(); 171 return NULL; 172 } 173 174 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, 175 OverpassLookupMode overpass_mode, 176 PrivateLookupMode private_mode) const { 177 #ifdef ASSERT 178 tty->print_cr("Error: uncached_lookup_method called on a klass oop." 179 " Likely error: reflection method does not correctly" 180 " wrap return value in a mirror object."); 181 #endif 182 ShouldNotReachHere(); 183 return NULL; 184 } 185 186 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() { 187 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD); 188 } 189 190 // "Normal" instantiation is preceeded by a MetaspaceObj allocation 191 // which zeros out memory - calloc equivalent. 192 // The constructor is also used from CppVtableCloner, 193 // which doesn't zero out the memory before calling the constructor. 194 // Need to set the _java_mirror field explicitly to not hit an assert that the field 195 // should be NULL before setting it. 196 Klass::Klass(KlassID id) : _id(id), 197 _java_mirror(NULL), 198 _prototype_header(markWord::prototype()), 199 _shared_class_path_index(-1) { 200 CDS_ONLY(_shared_class_flags = 0;) 201 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;) 202 _primary_supers[0] = this; 203 set_super_check_offset(in_bytes(primary_supers_offset())); 204 } 205 206 jint Klass::array_layout_helper(BasicType etype) { 207 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype"); 208 // Note that T_ARRAY is not allowed here. 209 int hsize = arrayOopDesc::base_offset_in_bytes(etype); 210 int esize = type2aelembytes(etype); 211 bool isobj = (etype == T_OBJECT); 212 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value; 213 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize)); 214 215 assert(lh < (int)_lh_neutral_value, "must look like an array layout"); 216 assert(layout_helper_is_array(lh), "correct kind"); 217 assert(layout_helper_is_objArray(lh) == isobj, "correct kind"); 218 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind"); 219 assert(layout_helper_header_size(lh) == hsize, "correct decode"); 220 assert(layout_helper_element_type(lh) == etype, "correct decode"); 221 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode"); 222 223 return lh; 224 } 225 226 bool Klass::can_be_primary_super_slow() const { 227 if (super() == NULL) 228 return true; 229 else if (super()->super_depth() >= primary_super_limit()-1) 230 return false; 231 else 232 return true; 233 } 234 235 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) { 236 if (k == NULL) { 237 set_super(NULL); 238 _primary_supers[0] = this; 239 assert(super_depth() == 0, "Object must already be initialized properly"); 240 } else if (k != super() || k == SystemDictionary::Object_klass()) { 241 assert(super() == NULL || super() == SystemDictionary::Object_klass(), 242 "initialize this only once to a non-trivial value"); 243 set_super(k); 244 Klass* sup = k; 245 int sup_depth = sup->super_depth(); 246 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit()); 247 if (!can_be_primary_super_slow()) 248 my_depth = primary_super_limit(); 249 for (juint i = 0; i < my_depth; i++) { 250 _primary_supers[i] = sup->_primary_supers[i]; 251 } 252 Klass* *super_check_cell; 253 if (my_depth < primary_super_limit()) { 254 _primary_supers[my_depth] = this; 255 super_check_cell = &_primary_supers[my_depth]; 256 } else { 257 // Overflow of the primary_supers array forces me to be secondary. 258 super_check_cell = &_secondary_super_cache; 259 } 260 set_super_check_offset((address)super_check_cell - (address) this); 261 262 #ifdef ASSERT 263 { 264 juint j = super_depth(); 265 assert(j == my_depth, "computed accessor gets right answer"); 266 Klass* t = this; 267 while (!t->can_be_primary_super()) { 268 t = t->super(); 269 j = t->super_depth(); 270 } 271 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) { 272 assert(primary_super_of_depth(j1) == NULL, "super list padding"); 273 } 274 while (t != NULL) { 275 assert(primary_super_of_depth(j) == t, "super list initialization"); 276 t = t->super(); 277 --j; 278 } 279 assert(j == (juint)-1, "correct depth count"); 280 } 281 #endif 282 } 283 284 if (secondary_supers() == NULL) { 285 286 // Now compute the list of secondary supertypes. 287 // Secondaries can occasionally be on the super chain, 288 // if the inline "_primary_supers" array overflows. 289 int extras = 0; 290 Klass* p; 291 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 292 ++extras; 293 } 294 295 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below 296 297 // Compute the "real" non-extra secondaries. 298 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces); 299 if (secondaries == NULL) { 300 // secondary_supers set by compute_secondary_supers 301 return; 302 } 303 304 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras); 305 306 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) { 307 int i; // Scan for overflow primaries being duplicates of 2nd'arys 308 309 // This happens frequently for very deeply nested arrays: the 310 // primary superclass chain overflows into the secondary. The 311 // secondary list contains the element_klass's secondaries with 312 // an extra array dimension added. If the element_klass's 313 // secondary list already contains some primary overflows, they 314 // (with the extra level of array-ness) will collide with the 315 // normal primary superclass overflows. 316 for( i = 0; i < secondaries->length(); i++ ) { 317 if( secondaries->at(i) == p ) 318 break; 319 } 320 if( i < secondaries->length() ) 321 continue; // It's a dup, don't put it in 322 primaries->push(p); 323 } 324 // Combine the two arrays into a metadata object to pack the array. 325 // The primaries are added in the reverse order, then the secondaries. 326 int new_length = primaries->length() + secondaries->length(); 327 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>( 328 class_loader_data(), new_length, CHECK); 329 int fill_p = primaries->length(); 330 for (int j = 0; j < fill_p; j++) { 331 s2->at_put(j, primaries->pop()); // add primaries in reverse order. 332 } 333 for( int j = 0; j < secondaries->length(); j++ ) { 334 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end. 335 } 336 337 #ifdef ASSERT 338 // We must not copy any NULL placeholders left over from bootstrap. 339 for (int j = 0; j < s2->length(); j++) { 340 assert(s2->at(j) != NULL, "correct bootstrapping order"); 341 } 342 #endif 343 344 set_secondary_supers(s2); 345 } 346 } 347 348 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots, 349 Array<InstanceKlass*>* transitive_interfaces) { 350 assert(num_extra_slots == 0, "override for complex klasses"); 351 assert(transitive_interfaces == NULL, "sanity"); 352 set_secondary_supers(Universe::the_empty_klass_array()); 353 return NULL; 354 } 355 356 357 // superklass links 358 InstanceKlass* Klass::superklass() const { 359 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass"); 360 return _super == NULL ? NULL : InstanceKlass::cast(_super); 361 } 362 363 // subklass links. Used by the compiler (and vtable initialization) 364 // May be cleaned concurrently, so must use the Compile_lock. 365 // The log parameter is for clean_weak_klass_links to report unlinked classes. 366 Klass* Klass::subklass(bool log) const { 367 // Need load_acquire on the _subklass, because it races with inserts that 368 // publishes freshly initialized data. 369 for (Klass* chain = OrderAccess::load_acquire(&_subklass); 370 chain != NULL; 371 // Do not need load_acquire on _next_sibling, because inserts never 372 // create _next_sibling edges to dead data. 373 chain = Atomic::load(&chain->_next_sibling)) 374 { 375 if (chain->is_loader_alive()) { 376 return chain; 377 } else if (log) { 378 if (log_is_enabled(Trace, class, unload)) { 379 ResourceMark rm; 380 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name()); 381 } 382 } 383 } 384 return NULL; 385 } 386 387 Klass* Klass::next_sibling(bool log) const { 388 // Do not need load_acquire on _next_sibling, because inserts never 389 // create _next_sibling edges to dead data. 390 for (Klass* chain = Atomic::load(&_next_sibling); 391 chain != NULL; 392 chain = Atomic::load(&chain->_next_sibling)) { 393 // Only return alive klass, there may be stale klass 394 // in this chain if cleaned concurrently. 395 if (chain->is_loader_alive()) { 396 return chain; 397 } else if (log) { 398 if (log_is_enabled(Trace, class, unload)) { 399 ResourceMark rm; 400 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name()); 401 } 402 } 403 } 404 return NULL; 405 } 406 407 void Klass::set_subklass(Klass* s) { 408 assert(s != this, "sanity check"); 409 OrderAccess::release_store(&_subklass, s); 410 } 411 412 void Klass::set_next_sibling(Klass* s) { 413 assert(s != this, "sanity check"); 414 // Does not need release semantics. If used by cleanup, it will link to 415 // already safely published data, and if used by inserts, will be published 416 // safely using cmpxchg. 417 Atomic::store(s, &_next_sibling); 418 } 419 420 void Klass::append_to_sibling_list() { 421 assert_locked_or_safepoint(Compile_lock); 422 debug_only(verify();) 423 // add ourselves to superklass' subklass list 424 InstanceKlass* super = superklass(); 425 if (super == NULL) return; // special case: class Object 426 assert((!super->is_interface() // interfaces cannot be supers 427 && (super->superklass() == NULL || !is_interface())), 428 "an interface can only be a subklass of Object"); 429 430 // Make sure there is no stale subklass head 431 super->clean_subklass(); 432 433 for (;;) { 434 Klass* prev_first_subklass = OrderAccess::load_acquire(&_super->_subklass); 435 if (prev_first_subklass != NULL) { 436 // set our sibling to be the superklass' previous first subklass 437 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses"); 438 set_next_sibling(prev_first_subklass); 439 } 440 // Note that the prev_first_subklass is always alive, meaning no sibling_next links 441 // are ever created to not alive klasses. This is an important invariant of the lock-free 442 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list. 443 if (Atomic::cmpxchg(this, &super->_subklass, prev_first_subklass) == prev_first_subklass) { 444 return; 445 } 446 } 447 debug_only(verify();) 448 } 449 450 void Klass::clean_subklass() { 451 for (;;) { 452 // Need load_acquire, due to contending with concurrent inserts 453 Klass* subklass = OrderAccess::load_acquire(&_subklass); 454 if (subklass == NULL || subklass->is_loader_alive()) { 455 return; 456 } 457 // Try to fix _subklass until it points at something not dead. 458 Atomic::cmpxchg(subklass->next_sibling(), &_subklass, subklass); 459 } 460 } 461 462 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) { 463 if (!ClassUnloading || !unloading_occurred) { 464 return; 465 } 466 467 Klass* root = SystemDictionary::Object_klass(); 468 Stack<Klass*, mtGC> stack; 469 470 stack.push(root); 471 while (!stack.is_empty()) { 472 Klass* current = stack.pop(); 473 474 assert(current->is_loader_alive(), "just checking, this should be live"); 475 476 // Find and set the first alive subklass 477 Klass* sub = current->subklass(true); 478 current->clean_subklass(); 479 if (sub != NULL) { 480 stack.push(sub); 481 } 482 483 // Find and set the first alive sibling 484 Klass* sibling = current->next_sibling(true); 485 current->set_next_sibling(sibling); 486 if (sibling != NULL) { 487 stack.push(sibling); 488 } 489 490 // Clean the implementors list and method data. 491 if (clean_alive_klasses && current->is_instance_klass()) { 492 InstanceKlass* ik = InstanceKlass::cast(current); 493 ik->clean_weak_instanceklass_links(); 494 495 // JVMTI RedefineClasses creates previous versions that are not in 496 // the class hierarchy, so process them here. 497 while ((ik = ik->previous_versions()) != NULL) { 498 ik->clean_weak_instanceklass_links(); 499 } 500 } 501 } 502 } 503 504 void Klass::metaspace_pointers_do(MetaspaceClosure* it) { 505 if (log_is_enabled(Trace, cds)) { 506 ResourceMark rm; 507 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name()); 508 } 509 510 it->push(&_name); 511 it->push(&_secondary_super_cache); 512 it->push(&_secondary_supers); 513 for (int i = 0; i < _primary_super_limit; i++) { 514 it->push(&_primary_supers[i]); 515 } 516 it->push(&_super); 517 it->push((Klass**)&_subklass); 518 it->push((Klass**)&_next_sibling); 519 it->push(&_next_link); 520 521 vtableEntry* vt = start_of_vtable(); 522 for (int i=0; i<vtable_length(); i++) { 523 it->push(vt[i].method_addr()); 524 } 525 } 526 527 void Klass::remove_unshareable_info() { 528 assert (DumpSharedSpaces || DynamicDumpSharedSpaces, 529 "only called during CDS dump time"); 530 JFR_ONLY(REMOVE_ID(this);) 531 if (log_is_enabled(Trace, cds, unshareable)) { 532 ResourceMark rm; 533 log_trace(cds, unshareable)("remove: %s", external_name()); 534 } 535 536 set_subklass(NULL); 537 set_next_sibling(NULL); 538 set_next_link(NULL); 539 540 // Null out class_loader_data because we don't share that yet. 541 set_class_loader_data(NULL); 542 set_is_shared(); 543 } 544 545 void Klass::remove_java_mirror() { 546 assert(DumpSharedSpaces || DynamicDumpSharedSpaces, "only called during CDS dump time"); 547 if (log_is_enabled(Trace, cds, unshareable)) { 548 ResourceMark rm; 549 log_trace(cds, unshareable)("remove java_mirror: %s", external_name()); 550 } 551 // Just null out the mirror. The class_loader_data() no longer exists. 552 _java_mirror = NULL; 553 } 554 555 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 556 assert(is_klass(), "ensure C++ vtable is restored"); 557 assert(is_shared(), "must be set"); 558 JFR_ONLY(RESTORE_ID(this);) 559 if (log_is_enabled(Trace, cds, unshareable)) { 560 ResourceMark rm; 561 log_trace(cds, unshareable)("restore: %s", external_name()); 562 } 563 564 // If an exception happened during CDS restore, some of these fields may already be 565 // set. We leave the class on the CLD list, even if incomplete so that we don't 566 // modify the CLD list outside a safepoint. 567 if (class_loader_data() == NULL) { 568 // Restore class_loader_data to the null class loader data 569 set_class_loader_data(loader_data); 570 571 // Workaround for suspected bug. Make sure other threads see this assignment. 572 // This shouldn't be necessary but the compiler thread seems to be behind 573 // the times, even though this thread takes MethodCompileQueue_lock and the thread 574 // that doesn't see this value also takes that lock. 575 OrderAccess::fence(); 576 577 // Add to null class loader list first before creating the mirror 578 // (same order as class file parsing) 579 loader_data->add_class(this); 580 } 581 582 Handle loader(THREAD, loader_data->class_loader()); 583 ModuleEntry* module_entry = NULL; 584 Klass* k = this; 585 if (k->is_objArray_klass()) { 586 k = ObjArrayKlass::cast(k)->bottom_klass(); 587 } 588 // Obtain klass' module. 589 if (k->is_instance_klass()) { 590 InstanceKlass* ik = (InstanceKlass*) k; 591 module_entry = ik->module(); 592 } else { 593 module_entry = ModuleEntryTable::javabase_moduleEntry(); 594 } 595 // Obtain java.lang.Module, if available 596 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL)); 597 598 if (this->has_raw_archived_mirror()) { 599 ResourceMark rm; 600 log_debug(cds, mirror)("%s has raw archived mirror", external_name()); 601 if (HeapShared::open_archive_heap_region_mapped()) { 602 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle, 603 protection_domain, 604 CHECK); 605 if (present) { 606 return; 607 } 608 } 609 610 // No archived mirror data 611 log_debug(cds, mirror)("No archived mirror data for %s", external_name()); 612 _java_mirror = NULL; 613 this->clear_has_raw_archived_mirror(); 614 } 615 616 // Only recreate it if not present. A previous attempt to restore may have 617 // gotten an OOM later but keep the mirror if it was created. 618 if (java_mirror() == NULL) { 619 log_trace(cds, mirror)("Recreate mirror for %s", external_name()); 620 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK); 621 } 622 } 623 624 #if INCLUDE_CDS_JAVA_HEAP 625 // Used at CDS dump time to access the archived mirror. No GC barrier. 626 oop Klass::archived_java_mirror_raw() { 627 assert(has_raw_archived_mirror(), "must have raw archived mirror"); 628 return CompressedOops::decode(_archived_mirror); 629 } 630 631 narrowOop Klass::archived_java_mirror_raw_narrow() { 632 assert(has_raw_archived_mirror(), "must have raw archived mirror"); 633 return _archived_mirror; 634 } 635 636 // No GC barrier 637 void Klass::set_archived_java_mirror_raw(oop m) { 638 assert(DumpSharedSpaces, "called only during runtime"); 639 _archived_mirror = CompressedOops::encode(m); 640 } 641 #endif // INCLUDE_CDS_JAVA_HEAP 642 643 Klass* Klass::array_klass_or_null(int rank) { 644 EXCEPTION_MARK; 645 // No exception can be thrown by array_klass_impl when called with or_null == true. 646 // (In anycase, the execption mark will fail if it do so) 647 return array_klass_impl(true, rank, THREAD); 648 } 649 650 651 Klass* Klass::array_klass_or_null() { 652 EXCEPTION_MARK; 653 // No exception can be thrown by array_klass_impl when called with or_null == true. 654 // (In anycase, the execption mark will fail if it do so) 655 return array_klass_impl(true, THREAD); 656 } 657 658 659 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) { 660 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass"); 661 return NULL; 662 } 663 664 665 Klass* Klass::array_klass_impl(bool or_null, TRAPS) { 666 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass"); 667 return NULL; 668 } 669 670 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) { 671 if (length > max_length) { 672 if (!THREAD->in_retryable_allocation()) { 673 report_java_out_of_memory("Requested array size exceeds VM limit"); 674 JvmtiExport::post_array_size_exhausted(); 675 THROW_OOP(Universe::out_of_memory_error_array_size()); 676 } else { 677 THROW_OOP(Universe::out_of_memory_error_retry()); 678 } 679 } else if (length < 0) { 680 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length)); 681 } 682 } 683 684 oop Klass::class_loader() const { return class_loader_data()->class_loader(); } 685 686 // In product mode, this function doesn't have virtual function calls so 687 // there might be some performance advantage to handling InstanceKlass here. 688 const char* Klass::external_name() const { 689 if (is_instance_klass()) { 690 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this); 691 if (ik->is_unsafe_anonymous()) { 692 char addr_buf[20]; 693 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik)); 694 size_t addr_len = strlen(addr_buf); 695 size_t name_len = name()->utf8_length(); 696 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1); 697 name()->as_klass_external_name(result, (int) name_len + 1); 698 assert(strlen(result) == name_len, ""); 699 strcpy(result + name_len, addr_buf); 700 assert(strlen(result) == name_len + addr_len, ""); 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(1, &_biased_lock_revocation_count); 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 klassVtable Klass::vtable() const { 830 return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size()); 831 } 832 833 vtableEntry* Klass::start_of_vtable() const { 834 return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset())); 835 } 836 837 Method* Klass::method_at_vtable(int index) { 838 #ifndef PRODUCT 839 assert(index >= 0, "valid vtable index"); 840 if (DebugVtables) { 841 verify_vtable_index(index); 842 } 843 #endif 844 return start_of_vtable()[index].method(); 845 } 846 847 ByteSize Klass::vtable_start_offset() { 848 return in_ByteSize(InstanceKlass::header_size() * wordSize); 849 } 850 851 #ifndef PRODUCT 852 853 bool Klass::verify_vtable_index(int i) { 854 int limit = vtable_length()/vtableEntry::size(); 855 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit); 856 return true; 857 } 858 859 #endif // PRODUCT 860 861 // Caller needs ResourceMark 862 // joint_in_module_of_loader provides an optimization if 2 classes are in 863 // the same module to succinctly print out relevant information about their 864 // module name and class loader's name_and_id for error messages. 865 // Format: 866 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2> 867 // are in module <module-name>[@<version>] 868 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 869 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const { 870 assert(module() == class2->module(), "classes do not have the same module"); 871 const char* class1_name = external_name(); 872 size_t len = strlen(class1_name) + 1; 873 874 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader); 875 len += strlen(class2_description); 876 877 len += strlen(" and "); 878 879 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 880 881 // Just return the FQN if error when allocating string 882 if (joint_description == NULL) { 883 return class1_name; 884 } 885 886 jio_snprintf(joint_description, len, "%s and %s", 887 class1_name, 888 class2_description); 889 890 return joint_description; 891 } 892 893 // Caller needs ResourceMark 894 // class_in_module_of_loader provides a standard way to include 895 // relevant information about a class, such as its module name as 896 // well as its class loader's name_and_id, in error messages and logging. 897 // Format: 898 // <fully-qualified-external-class-name> is in module <module-name>[@<version>] 899 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>] 900 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const { 901 // 1. fully qualified external name of class 902 const char* klass_name = external_name(); 903 size_t len = strlen(klass_name) + 1; 904 905 // 2. module name + @version 906 const char* module_name = ""; 907 const char* version = ""; 908 bool has_version = false; 909 bool module_is_named = false; 910 const char* module_name_phrase = ""; 911 const Klass* bottom_klass = is_objArray_klass() ? 912 ObjArrayKlass::cast(this)->bottom_klass() : this; 913 if (bottom_klass->is_instance_klass()) { 914 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module(); 915 if (module->is_named()) { 916 module_is_named = true; 917 module_name_phrase = "module "; 918 module_name = module->name()->as_C_string(); 919 len += strlen(module_name); 920 // Use version if exists and is not a jdk module 921 if (module->should_show_version()) { 922 has_version = true; 923 version = module->version()->as_C_string(); 924 // Include stlen(version) + 1 for the "@" 925 len += strlen(version) + 1; 926 } 927 } else { 928 module_name = UNNAMED_MODULE; 929 len += UNNAMED_MODULE_LEN; 930 } 931 } else { 932 // klass is an array of primitives, module is java.base 933 module_is_named = true; 934 module_name_phrase = "module "; 935 module_name = JAVA_BASE_NAME; 936 len += JAVA_BASE_NAME_LEN; 937 } 938 939 // 3. class loader's name_and_id 940 ClassLoaderData* cld = class_loader_data(); 941 assert(cld != NULL, "class_loader_data should not be null"); 942 const char* loader_name_and_id = cld->loader_name_and_id(); 943 len += strlen(loader_name_and_id); 944 945 // 4. include parent loader information 946 const char* parent_loader_phrase = ""; 947 const char* parent_loader_name_and_id = ""; 948 if (include_parent_loader && 949 !cld->is_builtin_class_loader_data()) { 950 oop parent_loader = java_lang_ClassLoader::parent(class_loader()); 951 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data_or_null(parent_loader); 952 // The parent loader's ClassLoaderData could be null if it is 953 // a delegating class loader that has never defined a class. 954 // In this case the loader's name must be obtained via the parent loader's oop. 955 if (parent_cld == NULL) { 956 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader); 957 if (cl_name_and_id != NULL) { 958 parent_loader_name_and_id = java_lang_String::as_utf8_string(cl_name_and_id); 959 } 960 } else { 961 parent_loader_name_and_id = parent_cld->loader_name_and_id(); 962 } 963 parent_loader_phrase = ", parent loader "; 964 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id); 965 } 966 967 // Start to construct final full class description string 968 len += ((use_are) ? strlen(" are in ") : strlen(" is in ")); 969 len += strlen(module_name_phrase) + strlen(" of loader "); 970 971 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len); 972 973 // Just return the FQN if error when allocating string 974 if (class_description == NULL) { 975 return klass_name; 976 } 977 978 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s", 979 klass_name, 980 (use_are) ? "are" : "is", 981 module_name_phrase, 982 module_name, 983 (has_version) ? "@" : "", 984 (has_version) ? version : "", 985 loader_name_and_id, 986 parent_loader_phrase, 987 parent_loader_name_and_id); 988 989 return class_description; 990 }