1 /*
2 * Copyright (c) 1997, 2023, 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 "cds/archiveHeapLoader.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/heapShared.hpp"
29 #include "classfile/classLoaderData.inline.hpp"
30 #include "classfile/classLoaderDataGraph.inline.hpp"
31 #include "classfile/javaClasses.inline.hpp"
32 #include "classfile/moduleEntry.hpp"
33 #include "classfile/systemDictionary.hpp"
34 #include "classfile/systemDictionaryShared.hpp"
35 #include "classfile/vmClasses.hpp"
36 #include "classfile/vmSymbols.hpp"
37 #include "gc/shared/collectedHeap.inline.hpp"
38 #include "jvm_io.h"
39 #include "logging/log.hpp"
40 #include "memory/metadataFactory.hpp"
41 #include "memory/metaspaceClosure.hpp"
42 #include "memory/oopFactory.hpp"
43 #include "memory/resourceArea.hpp"
44 #include "memory/universe.hpp"
45 #include "oops/compressedOops.inline.hpp"
46 #include "oops/instanceKlass.hpp"
47 #include "oops/klass.inline.hpp"
48 #include "oops/objArrayKlass.hpp"
49 #include "oops/oop.inline.hpp"
50 #include "oops/oopHandle.inline.hpp"
51 #include "prims/jvmtiExport.hpp"
52 #include "runtime/atomic.hpp"
53 #include "runtime/handles.inline.hpp"
54 #include "utilities/macros.hpp"
55 #include "utilities/powerOfTwo.hpp"
56 #include "utilities/stack.inline.hpp"
57
58 void Klass::set_java_mirror(Handle m) {
59 assert(!m.is_null(), "New mirror should never be null.");
60 assert(_java_mirror.is_empty(), "should only be used to initialize mirror");
61 _java_mirror = class_loader_data()->add_handle(m);
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(vmClasses::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 != nullptr) _name->increment_refcount();
87
88 if (CDSConfig::is_dumping_archive() && is_instance_klass()) {
89 SystemDictionaryShared::init_dumptime_info(InstanceKlass::cast(this));
90 }
91 }
92
93 bool Klass::is_subclass_of(const Klass* k) const {
94 // Run up the super chain and check
95 if (this == k) return true;
96
97 Klass* t = const_cast<Klass*>(this)->super();
98
99 while (t != nullptr) {
100 if (t == k) return true;
101 t = t->super();
102 }
103 return false;
104 }
105
106 void Klass::release_C_heap_structures(bool release_constant_pool) {
107 if (_name != nullptr) _name->decrement_refcount();
108 }
109
110 bool Klass::search_secondary_supers(Klass* k) const {
111 // Put some extra logic here out-of-line, before the search proper.
112 // This cuts down the size of the inline method.
113
114 // This is necessary, since I am never in my own secondary_super list.
115 if (this == k)
116 return true;
117 // Scan the array-of-objects for a match
118 int cnt = secondary_supers()->length();
119 for (int i = 0; i < cnt; i++) {
120 if (secondary_supers()->at(i) == k) {
121 ((Klass*)this)->set_secondary_super_cache(k);
122 return true;
123 }
124 }
125 return false;
126 }
127
128 // Return self, except for abstract classes with exactly 1
129 // implementor. Then return the 1 concrete implementation.
130 Klass *Klass::up_cast_abstract() {
131 Klass *r = this;
132 while( r->is_abstract() ) { // Receiver is abstract?
133 Klass *s = r->subklass(); // Check for exactly 1 subklass
134 if (s == nullptr || s->next_sibling() != nullptr) // Oops; wrong count; give up
135 return this; // Return 'this' as a no-progress flag
136 r = s; // Loop till find concrete class
137 }
138 return r; // Return the 1 concrete class
139 }
140
141 // Find LCA in class hierarchy
142 Klass *Klass::LCA( Klass *k2 ) {
143 Klass *k1 = this;
144 while( 1 ) {
145 if( k1->is_subtype_of(k2) ) return k2;
146 if( k2->is_subtype_of(k1) ) return k1;
147 k1 = k1->super();
148 k2 = k2->super();
149 }
150 }
151
152
153 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
154 ResourceMark rm(THREAD);
155 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
156 : vmSymbols::java_lang_InstantiationException(), external_name());
157 }
158
159
160 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
161 ResourceMark rm(THREAD);
162 assert(s != nullptr, "Throw NPE!");
163 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(),
164 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name()));
165 }
166
167
168 void Klass::initialize(TRAPS) {
169 ShouldNotReachHere();
170 }
171
172 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
173 #ifdef ASSERT
174 tty->print_cr("Error: find_field 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 nullptr;
180 }
181
182 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature,
183 OverpassLookupMode overpass_mode,
184 PrivateLookupMode private_mode) const {
185 #ifdef ASSERT
186 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
187 " Likely error: reflection method does not correctly"
188 " wrap return value in a mirror object.");
189 #endif
190 ShouldNotReachHere();
191 return nullptr;
192 }
193
194 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
195 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
196 }
197
198 Klass::Klass() : _kind(UnknownKlassKind) {
199 assert(CDSConfig::is_dumping_static_archive() || UseSharedSpaces, "only for cds");
200 }
201
202 // "Normal" instantiation is preceded by a MetaspaceObj allocation
203 // which zeros out memory - calloc equivalent.
204 // The constructor is also used from CppVtableCloner,
205 // which doesn't zero out the memory before calling the constructor.
206 Klass::Klass(KlassKind kind) : _kind(kind),
207 _shared_class_path_index(-1) {
208 CDS_ONLY(_shared_class_flags = 0;)
209 CDS_JAVA_HEAP_ONLY(_archived_mirror_index = -1;)
210 _primary_supers[0] = this;
211 set_super_check_offset(in_bytes(primary_supers_offset()));
212 }
213
214 jint Klass::array_layout_helper(BasicType etype) {
215 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
216 // Note that T_ARRAY is not allowed here.
217 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
218 int esize = type2aelembytes(etype);
219 bool isobj = (etype == T_OBJECT);
220 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
221 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
222
223 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
224 assert(layout_helper_is_array(lh), "correct kind");
225 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
226 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
227 assert(layout_helper_header_size(lh) == hsize, "correct decode");
228 assert(layout_helper_element_type(lh) == etype, "correct decode");
229 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
230
231 return lh;
232 }
233
234 bool Klass::can_be_primary_super_slow() const {
235 if (super() == nullptr)
236 return true;
237 else if (super()->super_depth() >= primary_super_limit()-1)
238 return false;
239 else
240 return true;
241 }
242
243 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) {
244 if (k == nullptr) {
245 set_super(nullptr);
246 _primary_supers[0] = this;
247 assert(super_depth() == 0, "Object must already be initialized properly");
248 } else if (k != super() || k == vmClasses::Object_klass()) {
249 assert(super() == nullptr || super() == vmClasses::Object_klass(),
250 "initialize this only once to a non-trivial value");
251 set_super(k);
252 Klass* sup = k;
253 int sup_depth = sup->super_depth();
254 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
255 if (!can_be_primary_super_slow())
256 my_depth = primary_super_limit();
257 for (juint i = 0; i < my_depth; i++) {
258 _primary_supers[i] = sup->_primary_supers[i];
259 }
260 Klass* *super_check_cell;
261 if (my_depth < primary_super_limit()) {
262 _primary_supers[my_depth] = this;
263 super_check_cell = &_primary_supers[my_depth];
264 } else {
265 // Overflow of the primary_supers array forces me to be secondary.
266 super_check_cell = &_secondary_super_cache;
267 }
268 set_super_check_offset(u4((address)super_check_cell - (address) this));
269
270 #ifdef ASSERT
271 {
272 juint j = super_depth();
273 assert(j == my_depth, "computed accessor gets right answer");
274 Klass* t = this;
275 while (!t->can_be_primary_super()) {
276 t = t->super();
277 j = t->super_depth();
278 }
279 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
280 assert(primary_super_of_depth(j1) == nullptr, "super list padding");
281 }
282 while (t != nullptr) {
283 assert(primary_super_of_depth(j) == t, "super list initialization");
284 t = t->super();
285 --j;
286 }
287 assert(j == (juint)-1, "correct depth count");
288 }
289 #endif
290 }
291
292 if (secondary_supers() == nullptr) {
293
294 // Now compute the list of secondary supertypes.
295 // Secondaries can occasionally be on the super chain,
296 // if the inline "_primary_supers" array overflows.
297 int extras = 0;
298 Klass* p;
299 for (p = super(); !(p == nullptr || p->can_be_primary_super()); p = p->super()) {
300 ++extras;
301 }
302
303 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
304
305 // Compute the "real" non-extra secondaries.
306 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces);
307 if (secondaries == nullptr) {
308 // secondary_supers set by compute_secondary_supers
309 return;
310 }
311
312 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
313
314 for (p = super(); !(p == nullptr || p->can_be_primary_super()); p = p->super()) {
315 int i; // Scan for overflow primaries being duplicates of 2nd'arys
316
317 // This happens frequently for very deeply nested arrays: the
318 // primary superclass chain overflows into the secondary. The
319 // secondary list contains the element_klass's secondaries with
320 // an extra array dimension added. If the element_klass's
321 // secondary list already contains some primary overflows, they
322 // (with the extra level of array-ness) will collide with the
323 // normal primary superclass overflows.
324 for( i = 0; i < secondaries->length(); i++ ) {
325 if( secondaries->at(i) == p )
326 break;
327 }
328 if( i < secondaries->length() )
329 continue; // It's a dup, don't put it in
330 primaries->push(p);
331 }
332 // Combine the two arrays into a metadata object to pack the array.
333 // The primaries are added in the reverse order, then the secondaries.
334 int new_length = primaries->length() + secondaries->length();
335 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
336 class_loader_data(), new_length, CHECK);
337 int fill_p = primaries->length();
338 for (int j = 0; j < fill_p; j++) {
339 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
340 }
341 for( int j = 0; j < secondaries->length(); j++ ) {
342 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
343 }
344
345 #ifdef ASSERT
346 // We must not copy any null placeholders left over from bootstrap.
347 for (int j = 0; j < s2->length(); j++) {
348 assert(s2->at(j) != nullptr, "correct bootstrapping order");
349 }
350 #endif
351
352 set_secondary_supers(s2);
353 }
354 }
355
356 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots,
357 Array<InstanceKlass*>* transitive_interfaces) {
358 assert(num_extra_slots == 0, "override for complex klasses");
359 assert(transitive_interfaces == nullptr, "sanity");
360 set_secondary_supers(Universe::the_empty_klass_array());
361 return nullptr;
362 }
363
364
365 // superklass links
366 InstanceKlass* Klass::superklass() const {
367 assert(super() == nullptr || super()->is_instance_klass(), "must be instance klass");
368 return _super == nullptr ? nullptr : InstanceKlass::cast(_super);
369 }
370
371 // subklass links. Used by the compiler (and vtable initialization)
372 // May be cleaned concurrently, so must use the Compile_lock.
373 // The log parameter is for clean_weak_klass_links to report unlinked classes.
374 Klass* Klass::subklass(bool log) const {
375 // Need load_acquire on the _subklass, because it races with inserts that
376 // publishes freshly initialized data.
377 for (Klass* chain = Atomic::load_acquire(&_subklass);
378 chain != nullptr;
379 // Do not need load_acquire on _next_sibling, because inserts never
380 // create _next_sibling edges to dead data.
381 chain = Atomic::load(&chain->_next_sibling))
382 {
383 if (chain->is_loader_alive()) {
384 return chain;
385 } else if (log) {
386 if (log_is_enabled(Trace, class, unload)) {
387 ResourceMark rm;
388 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name());
389 }
390 }
391 }
392 return nullptr;
393 }
394
395 Klass* Klass::next_sibling(bool log) const {
396 // Do not need load_acquire on _next_sibling, because inserts never
397 // create _next_sibling edges to dead data.
398 for (Klass* chain = Atomic::load(&_next_sibling);
399 chain != nullptr;
400 chain = Atomic::load(&chain->_next_sibling)) {
401 // Only return alive klass, there may be stale klass
402 // in this chain if cleaned concurrently.
403 if (chain->is_loader_alive()) {
404 return chain;
405 } else if (log) {
406 if (log_is_enabled(Trace, class, unload)) {
407 ResourceMark rm;
408 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name());
409 }
410 }
411 }
412 return nullptr;
413 }
414
415 void Klass::set_subklass(Klass* s) {
416 assert(s != this, "sanity check");
417 Atomic::release_store(&_subklass, s);
418 }
419
420 void Klass::set_next_sibling(Klass* s) {
421 assert(s != this, "sanity check");
422 // Does not need release semantics. If used by cleanup, it will link to
423 // already safely published data, and if used by inserts, will be published
424 // safely using cmpxchg.
425 Atomic::store(&_next_sibling, s);
426 }
427
428 void Klass::append_to_sibling_list() {
429 if (Universe::is_fully_initialized()) {
430 assert_locked_or_safepoint(Compile_lock);
431 }
432 debug_only(verify();)
433 // add ourselves to superklass' subklass list
434 InstanceKlass* super = superklass();
435 if (super == nullptr) return; // special case: class Object
436 assert((!super->is_interface() // interfaces cannot be supers
437 && (super->superklass() == nullptr || !is_interface())),
438 "an interface can only be a subklass of Object");
439
440 // Make sure there is no stale subklass head
441 super->clean_subklass();
442
443 for (;;) {
444 Klass* prev_first_subklass = Atomic::load_acquire(&_super->_subklass);
445 if (prev_first_subklass != nullptr) {
446 // set our sibling to be the superklass' previous first subklass
447 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses");
448 set_next_sibling(prev_first_subklass);
449 }
450 // Note that the prev_first_subklass is always alive, meaning no sibling_next links
451 // are ever created to not alive klasses. This is an important invariant of the lock-free
452 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list.
453 if (Atomic::cmpxchg(&super->_subklass, prev_first_subklass, this) == prev_first_subklass) {
454 return;
455 }
456 }
457 debug_only(verify();)
458 }
459
460 void Klass::clean_subklass() {
461 for (;;) {
462 // Need load_acquire, due to contending with concurrent inserts
463 Klass* subklass = Atomic::load_acquire(&_subklass);
464 if (subklass == nullptr || subklass->is_loader_alive()) {
465 return;
466 }
467 // Try to fix _subklass until it points at something not dead.
468 Atomic::cmpxchg(&_subklass, subklass, subklass->next_sibling());
469 }
470 }
471
472 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
473 if (!ClassUnloading || !unloading_occurred) {
474 return;
475 }
476
477 Klass* root = vmClasses::Object_klass();
478 Stack<Klass*, mtGC> stack;
479
480 stack.push(root);
481 while (!stack.is_empty()) {
482 Klass* current = stack.pop();
483
484 assert(current->is_loader_alive(), "just checking, this should be live");
485
486 // Find and set the first alive subklass
487 Klass* sub = current->subklass(true);
488 current->clean_subklass();
489 if (sub != nullptr) {
490 stack.push(sub);
491 }
492
493 // Find and set the first alive sibling
494 Klass* sibling = current->next_sibling(true);
495 current->set_next_sibling(sibling);
496 if (sibling != nullptr) {
497 stack.push(sibling);
498 }
499
500 // Clean the implementors list and method data.
501 if (clean_alive_klasses && current->is_instance_klass()) {
502 InstanceKlass* ik = InstanceKlass::cast(current);
503 ik->clean_weak_instanceklass_links();
504
505 // JVMTI RedefineClasses creates previous versions that are not in
506 // the class hierarchy, so process them here.
507 while ((ik = ik->previous_versions()) != nullptr) {
508 ik->clean_weak_instanceklass_links();
509 }
510 }
511 }
512 }
513
514 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
515 if (log_is_enabled(Trace, cds)) {
516 ResourceMark rm;
517 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
518 }
519
520 it->push(&_name);
521 it->push(&_secondary_super_cache);
522 it->push(&_secondary_supers);
523 for (int i = 0; i < _primary_super_limit; i++) {
524 it->push(&_primary_supers[i]);
525 }
526 it->push(&_super);
527 if (!CDSConfig::is_dumping_archive()) {
528 // If dumping archive, these may point to excluded classes. There's no need
529 // to follow these pointers anyway, as they will be set to null in
530 // remove_unshareable_info().
531 it->push((Klass**)&_subklass);
532 it->push((Klass**)&_next_sibling);
533 it->push(&_next_link);
534 }
535
536 vtableEntry* vt = start_of_vtable();
537 for (int i=0; i<vtable_length(); i++) {
538 it->push(vt[i].method_addr());
539 }
540 }
541
542 #if INCLUDE_CDS
543 void Klass::remove_unshareable_info() {
544 assert(CDSConfig::is_dumping_archive(),
545 "only called during CDS dump time");
546 JFR_ONLY(REMOVE_ID(this);)
547 if (log_is_enabled(Trace, cds, unshareable)) {
548 ResourceMark rm;
549 log_trace(cds, unshareable)("remove: %s", external_name());
550 }
551
552 set_subklass(nullptr);
553 set_next_sibling(nullptr);
554 set_next_link(nullptr);
555
556 // Null out class_loader_data because we don't share that yet.
557 set_class_loader_data(nullptr);
558 set_is_shared();
559 }
560
561 void Klass::remove_java_mirror() {
562 assert(CDSConfig::is_dumping_archive(), "sanity");
563 if (log_is_enabled(Trace, cds, unshareable)) {
564 ResourceMark rm;
565 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
566 }
567 // Just null out the mirror. The class_loader_data() no longer exists.
568 clear_java_mirror_handle();
569 }
570
571 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
572 assert(is_klass(), "ensure C++ vtable is restored");
573 assert(is_shared(), "must be set");
574 JFR_ONLY(RESTORE_ID(this);)
575 if (log_is_enabled(Trace, cds, unshareable)) {
576 ResourceMark rm(THREAD);
577 oop class_loader = loader_data->class_loader();
578 log_trace(cds, unshareable)("restore: %s with class loader: %s", external_name(),
579 class_loader != nullptr ? class_loader->klass()->external_name() : "boot");
580 }
581
582 // If an exception happened during CDS restore, some of these fields may already be
583 // set. We leave the class on the CLD list, even if incomplete so that we don't
584 // modify the CLD list outside a safepoint.
585 if (class_loader_data() == nullptr) {
586 set_class_loader_data(loader_data);
587
588 // Add to class loader list first before creating the mirror
589 // (same order as class file parsing)
590 loader_data->add_class(this);
591 }
592
593 Handle loader(THREAD, loader_data->class_loader());
594 ModuleEntry* module_entry = nullptr;
595 Klass* k = this;
596 if (k->is_objArray_klass()) {
597 k = ObjArrayKlass::cast(k)->bottom_klass();
598 }
599 // Obtain klass' module.
600 if (k->is_instance_klass()) {
601 InstanceKlass* ik = (InstanceKlass*) k;
602 module_entry = ik->module();
603 } else {
604 module_entry = ModuleEntryTable::javabase_moduleEntry();
605 }
606 // Obtain java.lang.Module, if available
607 Handle module_handle(THREAD, ((module_entry != nullptr) ? module_entry->module() : (oop)nullptr));
608
609 if (this->has_archived_mirror_index()) {
610 ResourceMark rm(THREAD);
611 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
612 if (ArchiveHeapLoader::is_in_use()) {
613 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle,
614 protection_domain,
615 CHECK);
616 if (present) {
617 return;
618 }
619 }
620
621 // No archived mirror data
622 log_debug(cds, mirror)("No archived mirror data for %s", external_name());
623 clear_java_mirror_handle();
624 this->clear_archived_mirror_index();
625 }
626
627 // Only recreate it if not present. A previous attempt to restore may have
628 // gotten an OOM later but keep the mirror if it was created.
629 if (java_mirror() == nullptr) {
630 ResourceMark rm(THREAD);
631 log_trace(cds, mirror)("Recreate mirror for %s", external_name());
632 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, Handle(), CHECK);
633 }
634 }
635 #endif // INCLUDE_CDS
636
637 #if INCLUDE_CDS_JAVA_HEAP
638 oop Klass::archived_java_mirror() {
639 assert(has_archived_mirror_index(), "must have archived mirror");
640 return HeapShared::get_root(_archived_mirror_index);
641 }
642
643 void Klass::clear_archived_mirror_index() {
644 if (_archived_mirror_index >= 0) {
645 HeapShared::clear_root(_archived_mirror_index);
646 }
647 _archived_mirror_index = -1;
648 }
649
650 // No GC barrier
651 void Klass::set_archived_java_mirror(int mirror_index) {
652 assert(CDSConfig::is_dumping_heap(), "sanity");
653 _archived_mirror_index = mirror_index;
654 }
655 #endif // INCLUDE_CDS_JAVA_HEAP
656
657 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) {
658 if (length > max_length) {
659 if (!THREAD->in_retryable_allocation()) {
660 report_java_out_of_memory("Requested array size exceeds VM limit");
661 JvmtiExport::post_array_size_exhausted();
662 THROW_OOP(Universe::out_of_memory_error_array_size());
663 } else {
664 THROW_OOP(Universe::out_of_memory_error_retry());
665 }
666 } else if (length < 0) {
667 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length));
668 }
669 }
670
671 // Replace the last '+' char with '/'.
672 static char* convert_hidden_name_to_java(Symbol* name) {
673 size_t name_len = name->utf8_length();
674 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1);
675 name->as_klass_external_name(result, (int)name_len + 1);
676 for (int index = (int)name_len; index > 0; index--) {
677 if (result[index] == '+') {
678 result[index] = JVM_SIGNATURE_SLASH;
679 break;
680 }
681 }
682 return result;
683 }
684
685 // In product mode, this function doesn't have virtual function calls so
686 // there might be some performance advantage to handling InstanceKlass here.
687 const char* Klass::external_name() const {
688 if (is_instance_klass()) {
689 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
690 if (ik->is_hidden()) {
691 char* result = convert_hidden_name_to_java(name());
692 return result;
693 }
694 } else if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) {
695 char* result = convert_hidden_name_to_java(name());
696 return result;
697 }
698 if (name() == nullptr) return "<unknown>";
699 return name()->as_klass_external_name();
700 }
701
702 const char* Klass::signature_name() const {
703 if (name() == nullptr) return "<unknown>";
704 if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) {
705 size_t name_len = name()->utf8_length();
706 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1);
707 name()->as_C_string(result, (int)name_len + 1);
708 for (int index = (int)name_len; index > 0; index--) {
709 if (result[index] == '+') {
710 result[index] = JVM_SIGNATURE_DOT;
711 break;
712 }
713 }
714 return result;
715 }
716 return name()->as_C_string();
717 }
718
719 const char* Klass::external_kind() const {
720 if (is_interface()) return "interface";
721 if (is_abstract()) return "abstract class";
722 return "class";
723 }
724
725 // Unless overridden, jvmti_class_status has no flags set.
726 jint Klass::jvmti_class_status() const {
727 return 0;
728 }
729
730
731 // Printing
732
733 void Klass::print_on(outputStream* st) const {
734 ResourceMark rm;
735 // print title
736 st->print("%s", internal_name());
737 print_address_on(st);
738 st->cr();
739 }
740
741 #define BULLET " - "
742
743 // Caller needs ResourceMark
744 void Klass::oop_print_on(oop obj, outputStream* st) {
745 // print title
746 st->print_cr("%s ", internal_name());
747 obj->print_address_on(st);
748
749 if (WizardMode) {
750 // print header
751 obj->mark().print_on(st);
752 st->cr();
753 }
754
755 // print class
756 st->print(BULLET"klass: ");
757 obj->klass()->print_value_on(st);
758 st->cr();
759 }
760
761 void Klass::oop_print_value_on(oop obj, outputStream* st) {
762 // print title
763 ResourceMark rm; // Cannot print in debug mode without this
764 st->print("%s", internal_name());
765 obj->print_address_on(st);
766 }
767
768 // Verification
769
770 void Klass::verify_on(outputStream* st) {
771
772 // This can be expensive, but it is worth checking that this klass is actually
773 // in the CLD graph but not in production.
774 assert(Metaspace::contains((address)this), "Should be");
775
776 guarantee(this->is_klass(),"should be klass");
777
778 if (super() != nullptr) {
779 guarantee(super()->is_klass(), "should be klass");
780 }
781 if (secondary_super_cache() != nullptr) {
782 Klass* ko = secondary_super_cache();
783 guarantee(ko->is_klass(), "should be klass");
784 }
785 for ( uint i = 0; i < primary_super_limit(); i++ ) {
786 Klass* ko = _primary_supers[i];
787 if (ko != nullptr) {
788 guarantee(ko->is_klass(), "should be klass");
789 }
790 }
791
792 if (java_mirror_no_keepalive() != nullptr) {
793 guarantee(java_lang_Class::is_instance(java_mirror_no_keepalive()), "should be instance");
794 }
795 }
796
797 void Klass::oop_verify_on(oop obj, outputStream* st) {
798 guarantee(oopDesc::is_oop(obj), "should be oop");
799 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
800 }
801
802 bool Klass::is_valid(Klass* k) {
803 if (!is_aligned(k, sizeof(MetaWord))) return false;
804 if ((size_t)k < os::min_page_size()) return false;
805
806 if (!os::is_readable_range(k, k + 1)) return false;
807 if (!Metaspace::contains(k)) return false;
808
809 if (!Symbol::is_valid(k->name())) return false;
810 return ClassLoaderDataGraph::is_valid(k->class_loader_data());
811 }
812
813 Method* Klass::method_at_vtable(int index) {
814 #ifndef PRODUCT
815 assert(index >= 0, "valid vtable index");
816 if (DebugVtables) {
817 verify_vtable_index(index);
818 }
819 #endif
820 return start_of_vtable()[index].method();
821 }
822
823
824 #ifndef PRODUCT
825
826 bool Klass::verify_vtable_index(int i) {
827 int limit = vtable_length()/vtableEntry::size();
828 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
829 return true;
830 }
831
832 #endif // PRODUCT
833
834 // Caller needs ResourceMark
835 // joint_in_module_of_loader provides an optimization if 2 classes are in
836 // the same module to succinctly print out relevant information about their
837 // module name and class loader's name_and_id for error messages.
838 // Format:
839 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2>
840 // are in module <module-name>[@<version>]
841 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
842 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const {
843 assert(module() == class2->module(), "classes do not have the same module");
844 const char* class1_name = external_name();
845 size_t len = strlen(class1_name) + 1;
846
847 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader);
848 len += strlen(class2_description);
849
850 len += strlen(" and ");
851
852 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
853
854 // Just return the FQN if error when allocating string
855 if (joint_description == nullptr) {
856 return class1_name;
857 }
858
859 jio_snprintf(joint_description, len, "%s and %s",
860 class1_name,
861 class2_description);
862
863 return joint_description;
864 }
865
866 // Caller needs ResourceMark
867 // class_in_module_of_loader provides a standard way to include
868 // relevant information about a class, such as its module name as
869 // well as its class loader's name_and_id, in error messages and logging.
870 // Format:
871 // <fully-qualified-external-class-name> is in module <module-name>[@<version>]
872 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
873 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const {
874 // 1. fully qualified external name of class
875 const char* klass_name = external_name();
876 size_t len = strlen(klass_name) + 1;
877
878 // 2. module name + @version
879 const char* module_name = "";
880 const char* version = "";
881 bool has_version = false;
882 bool module_is_named = false;
883 const char* module_name_phrase = "";
884 const Klass* bottom_klass = is_objArray_klass() ?
885 ObjArrayKlass::cast(this)->bottom_klass() : this;
886 if (bottom_klass->is_instance_klass()) {
887 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module();
888 if (module->is_named()) {
889 module_is_named = true;
890 module_name_phrase = "module ";
891 module_name = module->name()->as_C_string();
892 len += strlen(module_name);
893 // Use version if exists and is not a jdk module
894 if (module->should_show_version()) {
895 has_version = true;
896 version = module->version()->as_C_string();
897 // Include stlen(version) + 1 for the "@"
898 len += strlen(version) + 1;
899 }
900 } else {
901 module_name = UNNAMED_MODULE;
902 len += UNNAMED_MODULE_LEN;
903 }
904 } else {
905 // klass is an array of primitives, module is java.base
906 module_is_named = true;
907 module_name_phrase = "module ";
908 module_name = JAVA_BASE_NAME;
909 len += JAVA_BASE_NAME_LEN;
910 }
911
912 // 3. class loader's name_and_id
913 ClassLoaderData* cld = class_loader_data();
914 assert(cld != nullptr, "class_loader_data should not be null");
915 const char* loader_name_and_id = cld->loader_name_and_id();
916 len += strlen(loader_name_and_id);
917
918 // 4. include parent loader information
919 const char* parent_loader_phrase = "";
920 const char* parent_loader_name_and_id = "";
921 if (include_parent_loader &&
922 !cld->is_builtin_class_loader_data()) {
923 oop parent_loader = java_lang_ClassLoader::parent(class_loader());
924 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data_or_null(parent_loader);
925 // The parent loader's ClassLoaderData could be null if it is
926 // a delegating class loader that has never defined a class.
927 // In this case the loader's name must be obtained via the parent loader's oop.
928 if (parent_cld == nullptr) {
929 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader);
930 if (cl_name_and_id != nullptr) {
931 parent_loader_name_and_id = java_lang_String::as_utf8_string(cl_name_and_id);
932 }
933 } else {
934 parent_loader_name_and_id = parent_cld->loader_name_and_id();
935 }
936 parent_loader_phrase = ", parent loader ";
937 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id);
938 }
939
940 // Start to construct final full class description string
941 len += ((use_are) ? strlen(" are in ") : strlen(" is in "));
942 len += strlen(module_name_phrase) + strlen(" of loader ");
943
944 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
945
946 // Just return the FQN if error when allocating string
947 if (class_description == nullptr) {
948 return klass_name;
949 }
950
951 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s",
952 klass_name,
953 (use_are) ? "are" : "is",
954 module_name_phrase,
955 module_name,
956 (has_version) ? "@" : "",
957 (has_version) ? version : "",
958 loader_name_and_id,
959 parent_loader_phrase,
960 parent_loader_name_and_id);
961
962 return class_description;
963 }