1 /*
2 * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoaderData.inline.hpp"
27 #include "classfile/classLoaderDataGraph.inline.hpp"
28 #include "classfile/dictionary.hpp"
29 #include "classfile/javaClasses.hpp"
30 #include "classfile/moduleEntry.hpp"
31 #include "classfile/systemDictionary.hpp"
32 #include "classfile/systemDictionaryShared.hpp"
33 #include "classfile/vmSymbols.hpp"
34 #include "gc/shared/collectedHeap.inline.hpp"
35 #include "logging/log.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/arguments.hpp"
49 #include "runtime/atomic.hpp"
50 #include "runtime/handles.inline.hpp"
51 #include "utilities/macros.hpp"
52 #include "utilities/powerOfTwo.hpp"
53 #include "utilities/stack.inline.hpp"
54
55 void Klass::set_java_mirror(Handle m) {
56 assert(!m.is_null(), "New mirror should never be null.");
57 assert(_java_mirror.is_empty(), "should only be used to initialize mirror");
58 _java_mirror = class_loader_data()->add_handle(m);
59 }
60
61 oop Klass::java_mirror_no_keepalive() const {
62 return _java_mirror.peek();
63 }
64
65 void Klass::replace_java_mirror(oop mirror) {
66 _java_mirror.replace(mirror);
67 }
68
69 bool Klass::is_cloneable() const {
70 return _access_flags.is_cloneable_fast() ||
71 is_subtype_of(SystemDictionary::Cloneable_klass());
72 }
73
74 void Klass::set_is_cloneable() {
75 if (name() == vmSymbols::java_lang_invoke_MemberName()) {
76 assert(is_final(), "no subclasses allowed");
77 // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
78 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) {
79 // Reference cloning should not be intrinsified and always happen in JVM_Clone.
80 } else {
81 _access_flags.set_is_cloneable_fast();
82 }
83 }
84
85 void Klass::set_name(Symbol* n) {
86 _name = n;
87 if (_name != NULL) _name->increment_refcount();
88
89 if (Arguments::is_dumping_archive() && is_instance_klass()) {
90 SystemDictionaryShared::init_dumptime_info(InstanceKlass::cast(this));
91 }
92 }
93
94 bool Klass::is_subclass_of(const Klass* k) const {
95 // Run up the super chain and check
96 if (this == k) return true;
97
98 Klass* t = const_cast<Klass*>(this)->super();
99
100 while (t != NULL) {
101 if (t == k) return true;
102 t = t->super();
103 }
104 return false;
105 }
106
107 void Klass::release_C_heap_structures() {
108 if (_name != NULL) _name->decrement_refcount();
109 }
110
111 bool Klass::search_secondary_supers(Klass* k) const {
112 // Put some extra logic here out-of-line, before the search proper.
113 // This cuts down the size of the inline method.
114
115 // This is necessary, since I am never in my own secondary_super list.
116 if (this == k)
117 return true;
118 // Scan the array-of-objects for a match
119 int cnt = secondary_supers()->length();
120 for (int i = 0; i < cnt; i++) {
121 if (secondary_supers()->at(i) == k) {
122 ((Klass*)this)->set_secondary_super_cache(k);
123 return true;
124 }
125 }
126 return false;
127 }
128
129 // Return self, except for abstract classes with exactly 1
130 // implementor. Then return the 1 concrete implementation.
131 Klass *Klass::up_cast_abstract() {
132 Klass *r = this;
133 while( r->is_abstract() ) { // Receiver is abstract?
134 Klass *s = r->subklass(); // Check for exactly 1 subklass
135 if (s == NULL || s->next_sibling() != NULL) // Oops; wrong count; give up
136 return this; // Return 'this' as a no-progress flag
137 r = s; // Loop till find concrete class
138 }
139 return r; // Return the 1 concrete class
140 }
141
142 // Find LCA in class hierarchy
143 Klass *Klass::LCA( Klass *k2 ) {
144 Klass *k1 = this;
145 while( 1 ) {
146 if( k1->is_subtype_of(k2) ) return k2;
147 if( k2->is_subtype_of(k1) ) return k1;
148 k1 = k1->super();
149 k2 = k2->super();
150 }
151 }
152
153
154 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
155 ResourceMark rm(THREAD);
156 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
157 : vmSymbols::java_lang_InstantiationException(), external_name());
158 }
159
160
161 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
162 ResourceMark rm(THREAD);
163 assert(s != NULL, "Throw NPE!");
164 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(),
165 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name()));
166 }
167
168
169 void Klass::initialize(TRAPS) {
170 ShouldNotReachHere();
171 }
172
173 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
174 #ifdef ASSERT
175 tty->print_cr("Error: find_field called on a klass oop."
176 " Likely error: reflection method does not correctly"
177 " wrap return value in a mirror object.");
178 #endif
179 ShouldNotReachHere();
180 return NULL;
181 }
182
183 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature,
184 OverpassLookupMode overpass_mode,
185 PrivateLookupMode private_mode) const {
186 #ifdef ASSERT
187 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
188 " Likely error: reflection method does not correctly"
189 " wrap return value in a mirror object.");
190 #endif
191 ShouldNotReachHere();
192 return NULL;
193 }
194
195 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
196 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
197 }
198
199 // "Normal" instantiation is preceeded by a MetaspaceObj allocation
200 // which zeros out memory - calloc equivalent.
201 // The constructor is also used from CppVtableCloner,
202 // which doesn't zero out the memory before calling the constructor.
203 Klass::Klass(KlassID id) : _id(id),
204 _prototype_header(markWord::prototype()),
205 _shared_class_path_index(-1) {
206 CDS_ONLY(_shared_class_flags = 0);
207 CDS_JAVA_HEAP_ONLY(_archived_mirror_index = -1);
208 _primary_supers[0] = this;
209 set_super_check_offset(in_bytes(primary_supers_offset()));
210 }
211
212 jint Klass::array_layout_helper(BasicType etype) {
213 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
214 // Note that T_ARRAY is not allowed here.
215 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
216 int esize = type2aelembytes(etype);
217 bool isobj = (etype == T_OBJECT);
218 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
219 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
220
221 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
222 assert(layout_helper_is_array(lh), "correct kind");
223 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
224 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
225 assert(layout_helper_header_size(lh) == hsize, "correct decode");
226 assert(layout_helper_element_type(lh) == etype, "correct decode");
227 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
228
229 return lh;
230 }
231
232 bool Klass::can_be_primary_super_slow() const {
233 if (super() == NULL)
234 return true;
235 else if (super()->super_depth() >= primary_super_limit()-1)
236 return false;
237 else
238 return true;
239 }
240
241 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) {
242 if (k == NULL) {
243 set_super(NULL);
244 _primary_supers[0] = this;
245 assert(super_depth() == 0, "Object must already be initialized properly");
246 } else if (k != super() || k == SystemDictionary::Object_klass()) {
247 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
248 "initialize this only once to a non-trivial value");
249 set_super(k);
250 Klass* sup = k;
251 int sup_depth = sup->super_depth();
252 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
253 if (!can_be_primary_super_slow())
254 my_depth = primary_super_limit();
255 for (juint i = 0; i < my_depth; i++) {
256 _primary_supers[i] = sup->_primary_supers[i];
257 }
258 Klass* *super_check_cell;
259 if (my_depth < primary_super_limit()) {
260 _primary_supers[my_depth] = this;
261 super_check_cell = &_primary_supers[my_depth];
262 } else {
263 // Overflow of the primary_supers array forces me to be secondary.
264 super_check_cell = &_secondary_super_cache;
265 }
266 set_super_check_offset((address)super_check_cell - (address) this);
267
268 #ifdef ASSERT
269 {
270 juint j = super_depth();
271 assert(j == my_depth, "computed accessor gets right answer");
272 Klass* t = this;
273 while (!t->can_be_primary_super()) {
274 t = t->super();
275 j = t->super_depth();
276 }
277 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
278 assert(primary_super_of_depth(j1) == NULL, "super list padding");
279 }
280 while (t != NULL) {
281 assert(primary_super_of_depth(j) == t, "super list initialization");
282 t = t->super();
283 --j;
284 }
285 assert(j == (juint)-1, "correct depth count");
286 }
287 #endif
288 }
289
290 if (secondary_supers() == NULL) {
291
292 // Now compute the list of secondary supertypes.
293 // Secondaries can occasionally be on the super chain,
294 // if the inline "_primary_supers" array overflows.
295 int extras = 0;
296 Klass* p;
297 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
298 ++extras;
299 }
300
301 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
302
303 // Compute the "real" non-extra secondaries.
304 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces);
305 if (secondaries == NULL) {
306 // secondary_supers set by compute_secondary_supers
307 return;
308 }
309
310 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
311
312 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
313 int i; // Scan for overflow primaries being duplicates of 2nd'arys
314
315 // This happens frequently for very deeply nested arrays: the
316 // primary superclass chain overflows into the secondary. The
317 // secondary list contains the element_klass's secondaries with
318 // an extra array dimension added. If the element_klass's
319 // secondary list already contains some primary overflows, they
320 // (with the extra level of array-ness) will collide with the
321 // normal primary superclass overflows.
322 for( i = 0; i < secondaries->length(); i++ ) {
323 if( secondaries->at(i) == p )
324 break;
325 }
326 if( i < secondaries->length() )
327 continue; // It's a dup, don't put it in
328 primaries->push(p);
329 }
330 // Combine the two arrays into a metadata object to pack the array.
331 // The primaries are added in the reverse order, then the secondaries.
332 int new_length = primaries->length() + secondaries->length();
333 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
334 class_loader_data(), new_length, CHECK);
335 int fill_p = primaries->length();
336 for (int j = 0; j < fill_p; j++) {
337 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
338 }
339 for( int j = 0; j < secondaries->length(); j++ ) {
340 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
341 }
342
343 #ifdef ASSERT
344 // We must not copy any NULL placeholders left over from bootstrap.
345 for (int j = 0; j < s2->length(); j++) {
346 assert(s2->at(j) != NULL, "correct bootstrapping order");
347 }
348 #endif
349
350 set_secondary_supers(s2);
351 }
352 }
353
354 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots,
355 Array<InstanceKlass*>* transitive_interfaces) {
356 assert(num_extra_slots == 0, "override for complex klasses");
357 assert(transitive_interfaces == NULL, "sanity");
358 set_secondary_supers(Universe::the_empty_klass_array());
359 return NULL;
360 }
361
362
363 // superklass links
364 InstanceKlass* Klass::superklass() const {
365 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
366 return _super == NULL ? NULL : InstanceKlass::cast(_super);
367 }
368
369 // subklass links. Used by the compiler (and vtable initialization)
370 // May be cleaned concurrently, so must use the Compile_lock.
371 // The log parameter is for clean_weak_klass_links to report unlinked classes.
372 Klass* Klass::subklass(bool log) const {
373 // Need load_acquire on the _subklass, because it races with inserts that
374 // publishes freshly initialized data.
375 for (Klass* chain = Atomic::load_acquire(&_subklass);
376 chain != NULL;
377 // Do not need load_acquire on _next_sibling, because inserts never
378 // create _next_sibling edges to dead data.
379 chain = Atomic::load(&chain->_next_sibling))
380 {
381 if (chain->is_loader_alive()) {
382 return chain;
383 } else if (log) {
384 if (log_is_enabled(Trace, class, unload)) {
385 ResourceMark rm;
386 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name());
387 }
388 }
389 }
390 return NULL;
391 }
392
393 Klass* Klass::next_sibling(bool log) const {
394 // Do not need load_acquire on _next_sibling, because inserts never
395 // create _next_sibling edges to dead data.
396 for (Klass* chain = Atomic::load(&_next_sibling);
397 chain != NULL;
398 chain = Atomic::load(&chain->_next_sibling)) {
399 // Only return alive klass, there may be stale klass
400 // in this chain if cleaned concurrently.
401 if (chain->is_loader_alive()) {
402 return chain;
403 } else if (log) {
404 if (log_is_enabled(Trace, class, unload)) {
405 ResourceMark rm;
406 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name());
407 }
408 }
409 }
410 return NULL;
411 }
412
413 void Klass::set_subklass(Klass* s) {
414 assert(s != this, "sanity check");
415 Atomic::release_store(&_subklass, s);
416 }
417
418 void Klass::set_next_sibling(Klass* s) {
419 assert(s != this, "sanity check");
420 // Does not need release semantics. If used by cleanup, it will link to
421 // already safely published data, and if used by inserts, will be published
422 // safely using cmpxchg.
423 Atomic::store(&_next_sibling, s);
424 }
425
426 void Klass::append_to_sibling_list() {
427 if (Universe::is_fully_initialized()) {
428 assert_locked_or_safepoint(Compile_lock);
429 }
430 debug_only(verify();)
431 // add ourselves to superklass' subklass list
432 InstanceKlass* super = superklass();
433 if (super == NULL) return; // special case: class Object
434 assert((!super->is_interface() // interfaces cannot be supers
435 && (super->superklass() == NULL || !is_interface())),
436 "an interface can only be a subklass of Object");
437
438 // Make sure there is no stale subklass head
439 super->clean_subklass();
440
441 for (;;) {
442 Klass* prev_first_subklass = Atomic::load_acquire(&_super->_subklass);
443 if (prev_first_subklass != NULL) {
444 // set our sibling to be the superklass' previous first subklass
445 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses");
446 set_next_sibling(prev_first_subklass);
447 }
448 // Note that the prev_first_subklass is always alive, meaning no sibling_next links
449 // are ever created to not alive klasses. This is an important invariant of the lock-free
450 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list.
451 if (Atomic::cmpxchg(&super->_subklass, prev_first_subklass, this) == prev_first_subklass) {
452 return;
453 }
454 }
455 debug_only(verify();)
456 }
457
458 void Klass::clean_subklass() {
459 for (;;) {
460 // Need load_acquire, due to contending with concurrent inserts
461 Klass* subklass = Atomic::load_acquire(&_subklass);
462 if (subklass == NULL || subklass->is_loader_alive()) {
463 return;
464 }
465 // Try to fix _subklass until it points at something not dead.
466 Atomic::cmpxchg(&_subklass, subklass, subklass->next_sibling());
467 }
468 }
469
470 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
471 if (!ClassUnloading || !unloading_occurred) {
472 return;
473 }
474
475 Klass* root = SystemDictionary::Object_klass();
476 Stack<Klass*, mtGC> stack;
477
478 stack.push(root);
479 while (!stack.is_empty()) {
480 Klass* current = stack.pop();
481
482 assert(current->is_loader_alive(), "just checking, this should be live");
483
484 // Find and set the first alive subklass
485 Klass* sub = current->subklass(true);
486 current->clean_subklass();
487 if (sub != NULL) {
488 stack.push(sub);
489 }
490
491 // Find and set the first alive sibling
492 Klass* sibling = current->next_sibling(true);
493 current->set_next_sibling(sibling);
494 if (sibling != NULL) {
495 stack.push(sibling);
496 }
497
498 // Clean the implementors list and method data.
499 if (clean_alive_klasses && current->is_instance_klass()) {
500 InstanceKlass* ik = InstanceKlass::cast(current);
501 ik->clean_weak_instanceklass_links();
502
503 // JVMTI RedefineClasses creates previous versions that are not in
504 // the class hierarchy, so process them here.
505 while ((ik = ik->previous_versions()) != NULL) {
506 ik->clean_weak_instanceklass_links();
507 }
508 }
509 }
510 }
511
512 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
513 if (log_is_enabled(Trace, cds)) {
514 ResourceMark rm;
515 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
516 }
517
518 it->push(&_name);
519 it->push(&_secondary_super_cache);
520 it->push(&_secondary_supers);
521 for (int i = 0; i < _primary_super_limit; i++) {
522 it->push(&_primary_supers[i]);
523 }
524 it->push(&_super);
525 it->push((Klass**)&_subklass);
526 it->push((Klass**)&_next_sibling);
527 it->push(&_next_link);
528
529 vtableEntry* vt = start_of_vtable();
530 for (int i=0; i<vtable_length(); i++) {
531 it->push(vt[i].method_addr());
532 }
533 }
534
535 void Klass::remove_unshareable_info() {
536 assert (Arguments::is_dumping_archive(),
537 "only called during CDS dump time");
538 JFR_ONLY(REMOVE_ID(this);)
539 if (log_is_enabled(Trace, cds, unshareable)) {
540 ResourceMark rm;
541 log_trace(cds, unshareable)("remove: %s", external_name());
542 }
543
544 set_subklass(NULL);
545 set_next_sibling(NULL);
546 set_next_link(NULL);
547
548 // Null out class_loader_data because we don't share that yet.
549 set_class_loader_data(NULL);
550 set_is_shared();
551 }
552
553 void Klass::remove_java_mirror() {
554 Arguments::assert_is_dumping_archive();
555 if (log_is_enabled(Trace, cds, unshareable)) {
556 ResourceMark rm;
557 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
558 }
559 // Just null out the mirror. The class_loader_data() no longer exists.
560 clear_java_mirror_handle();
561 }
562
563 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
564 assert(is_klass(), "ensure C++ vtable is restored");
565 assert(is_shared(), "must be set");
566 JFR_ONLY(RESTORE_ID(this);)
567 if (log_is_enabled(Trace, cds, unshareable)) {
568 ResourceMark rm(THREAD);
569 log_trace(cds, unshareable)("restore: %s", external_name());
570 }
571
572 // If an exception happened during CDS restore, some of these fields may already be
573 // set. We leave the class on the CLD list, even if incomplete so that we don't
574 // modify the CLD list outside a safepoint.
575 if (class_loader_data() == NULL) {
576 set_class_loader_data(loader_data);
577
578 // Add to class loader list first before creating the mirror
579 // (same order as class file parsing)
580 loader_data->add_class(this);
581 }
582
583 Handle loader(THREAD, loader_data->class_loader());
584 ModuleEntry* module_entry = NULL;
585 Klass* k = this;
586 if (k->is_objArray_klass()) {
587 k = ObjArrayKlass::cast(k)->bottom_klass();
588 }
589 // Obtain klass' module.
590 if (k->is_instance_klass()) {
591 InstanceKlass* ik = (InstanceKlass*) k;
592 module_entry = ik->module();
593 } else {
594 module_entry = ModuleEntryTable::javabase_moduleEntry();
595 }
596 // Obtain java.lang.Module, if available
597 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
598
599 if (this->has_archived_mirror_index()) {
600 ResourceMark rm(THREAD);
601 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
602 if (HeapShared::open_archive_heap_region_mapped()) {
603 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle,
604 protection_domain,
605 CHECK);
606 if (present) {
607 return;
608 }
609 }
610
611 // No archived mirror data
612 log_debug(cds, mirror)("No archived mirror data for %s", external_name());
613 clear_java_mirror_handle();
614 this->clear_archived_mirror_index();
615 }
616
617 // Only recreate it if not present. A previous attempt to restore may have
618 // gotten an OOM later but keep the mirror if it was created.
619 if (java_mirror() == NULL) {
620 log_trace(cds, mirror)("Recreate mirror for %s", external_name());
621 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, Handle(), CHECK);
622 }
623 }
624
625 #if INCLUDE_CDS_JAVA_HEAP
626 oop Klass::archived_java_mirror() {
627 assert(has_archived_mirror_index(), "must have archived mirror");
628 return HeapShared::get_root(_archived_mirror_index);
629 }
630
631 void Klass::clear_archived_mirror_index() {
632 if (_archived_mirror_index >= 0) {
633 HeapShared::clear_root(_archived_mirror_index);
634 }
635 _archived_mirror_index = -1;
636 }
637
638 // No GC barrier
639 void Klass::set_archived_java_mirror(oop m) {
640 assert(DumpSharedSpaces, "called only during runtime");
641 _archived_mirror_index = HeapShared::append_root(m);
642 }
643 #endif // INCLUDE_CDS_JAVA_HEAP
644
645 Klass* Klass::array_klass_or_null(int rank) {
646 EXCEPTION_MARK;
647 // No exception can be thrown by array_klass_impl when called with or_null == true.
648 // (In anycase, the execption mark will fail if it do so)
649 return array_klass_impl(true, rank, THREAD);
650 }
651
652
653 Klass* Klass::array_klass_or_null() {
654 EXCEPTION_MARK;
655 // No exception can be thrown by array_klass_impl when called with or_null == true.
656 // (In anycase, the execption mark will fail if it do so)
657 return array_klass_impl(true, THREAD);
658 }
659
660
661 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
662 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
663 return NULL;
664 }
665
666
667 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
668 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
669 return NULL;
670 }
671
672 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) {
673 if (length > max_length) {
674 if (!THREAD->in_retryable_allocation()) {
675 report_java_out_of_memory("Requested array size exceeds VM limit");
676 JvmtiExport::post_array_size_exhausted();
677 THROW_OOP(Universe::out_of_memory_error_array_size());
678 } else {
679 THROW_OOP(Universe::out_of_memory_error_retry());
680 }
681 } else if (length < 0) {
682 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length));
683 }
684 }
685
686 // Replace the last '+' char with '/'.
687 static char* convert_hidden_name_to_java(Symbol* name) {
688 size_t name_len = name->utf8_length();
689 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1);
690 name->as_klass_external_name(result, (int)name_len + 1);
691 for (int index = (int)name_len; index > 0; index--) {
692 if (result[index] == '+') {
693 result[index] = JVM_SIGNATURE_SLASH;
694 break;
695 }
696 }
697 return result;
698 }
699
700 // In product mode, this function doesn't have virtual function calls so
701 // there might be some performance advantage to handling InstanceKlass here.
702 const char* Klass::external_name() const {
703 if (is_instance_klass()) {
704 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
705 if (ik->is_unsafe_anonymous()) {
706 char addr_buf[20];
707 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
708 size_t addr_len = strlen(addr_buf);
709 size_t name_len = name()->utf8_length();
710 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
711 name()->as_klass_external_name(result, (int) name_len + 1);
712 assert(strlen(result) == name_len, "");
713 strcpy(result + name_len, addr_buf);
714 assert(strlen(result) == name_len + addr_len, "");
715 return result;
716
717 } else if (ik->is_hidden()) {
718 char* result = convert_hidden_name_to_java(name());
719 return result;
720 }
721 } else if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) {
722 char* result = convert_hidden_name_to_java(name());
723 return result;
724 }
725 if (name() == NULL) return "<unknown>";
726 return name()->as_klass_external_name();
727 }
728
729 const char* Klass::signature_name() const {
730 if (name() == NULL) return "<unknown>";
731 if (is_objArray_klass() && ObjArrayKlass::cast(this)->bottom_klass()->is_hidden()) {
732 size_t name_len = name()->utf8_length();
733 char* result = NEW_RESOURCE_ARRAY(char, name_len + 1);
734 name()->as_C_string(result, (int)name_len + 1);
735 for (int index = (int)name_len; index > 0; index--) {
736 if (result[index] == '+') {
737 result[index] = JVM_SIGNATURE_DOT;
738 break;
739 }
740 }
741 return result;
742 }
743 return name()->as_C_string();
744 }
745
746 const char* Klass::external_kind() const {
747 if (is_interface()) return "interface";
748 if (is_abstract()) return "abstract class";
749 return "class";
750 }
751
752 // Unless overridden, modifier_flags is 0.
753 jint Klass::compute_modifier_flags(TRAPS) const {
754 return 0;
755 }
756
757 int Klass::atomic_incr_biased_lock_revocation_count() {
758 return (int) Atomic::add(&_biased_lock_revocation_count, 1);
759 }
760
761 // Unless overridden, jvmti_class_status has no flags set.
762 jint Klass::jvmti_class_status() const {
763 return 0;
764 }
765
766
767 // Printing
768
769 void Klass::print_on(outputStream* st) const {
770 ResourceMark rm;
771 // print title
772 st->print("%s", internal_name());
773 print_address_on(st);
774 st->cr();
775 }
776
777 #define BULLET " - "
778
779 // Caller needs ResourceMark
780 void Klass::oop_print_on(oop obj, outputStream* st) {
781 // print title
782 st->print_cr("%s ", internal_name());
783 obj->print_address_on(st);
784
785 if (WizardMode) {
786 // print header
787 obj->mark().print_on(st);
788 st->cr();
789 st->print(BULLET"prototype_header: " INTPTR_FORMAT, _prototype_header.value());
790 st->cr();
791 }
792
793 // print class
794 st->print(BULLET"klass: ");
795 obj->klass()->print_value_on(st);
796 st->cr();
797 }
798
799 void Klass::oop_print_value_on(oop obj, outputStream* st) {
800 // print title
801 ResourceMark rm; // Cannot print in debug mode without this
802 st->print("%s", internal_name());
803 obj->print_address_on(st);
804 }
805
806 // Verification
807
808 void Klass::verify_on(outputStream* st) {
809
810 // This can be expensive, but it is worth checking that this klass is actually
811 // in the CLD graph but not in production.
812 assert(Metaspace::contains((address)this), "Should be");
813
814 guarantee(this->is_klass(),"should be klass");
815
816 if (super() != NULL) {
817 guarantee(super()->is_klass(), "should be klass");
818 }
819 if (secondary_super_cache() != NULL) {
820 Klass* ko = secondary_super_cache();
821 guarantee(ko->is_klass(), "should be klass");
822 }
823 for ( uint i = 0; i < primary_super_limit(); i++ ) {
824 Klass* ko = _primary_supers[i];
825 if (ko != NULL) {
826 guarantee(ko->is_klass(), "should be klass");
827 }
828 }
829
830 if (java_mirror_no_keepalive() != NULL) {
831 guarantee(oopDesc::is_oop(java_mirror_no_keepalive()), "should be instance");
832 }
833 }
834
835 void Klass::oop_verify_on(oop obj, outputStream* st) {
836 guarantee(oopDesc::is_oop(obj), "should be oop");
837 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
838 }
839
840 bool Klass::is_valid(Klass* k) {
841 if (!is_aligned(k, sizeof(MetaWord))) return false;
842 if ((size_t)k < os::min_page_size()) return false;
843
844 if (!os::is_readable_range(k, k + 1)) return false;
845 if (!Metaspace::contains(k)) return false;
846
847 if (!Symbol::is_valid(k->name())) return false;
848 return ClassLoaderDataGraph::is_valid(k->class_loader_data());
849 }
850
851 Method* Klass::method_at_vtable(int index) {
852 #ifndef PRODUCT
853 assert(index >= 0, "valid vtable index");
854 if (DebugVtables) {
855 verify_vtable_index(index);
856 }
857 #endif
858 return start_of_vtable()[index].method();
859 }
860
861
862 #ifndef PRODUCT
863
864 bool Klass::verify_vtable_index(int i) {
865 int limit = vtable_length()/vtableEntry::size();
866 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
867 return true;
868 }
869
870 #endif // PRODUCT
871
872 // Caller needs ResourceMark
873 // joint_in_module_of_loader provides an optimization if 2 classes are in
874 // the same module to succinctly print out relevant information about their
875 // module name and class loader's name_and_id for error messages.
876 // Format:
877 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2>
878 // are in module <module-name>[@<version>]
879 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
880 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const {
881 assert(module() == class2->module(), "classes do not have the same module");
882 const char* class1_name = external_name();
883 size_t len = strlen(class1_name) + 1;
884
885 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader);
886 len += strlen(class2_description);
887
888 len += strlen(" and ");
889
890 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
891
892 // Just return the FQN if error when allocating string
893 if (joint_description == NULL) {
894 return class1_name;
895 }
896
897 jio_snprintf(joint_description, len, "%s and %s",
898 class1_name,
899 class2_description);
900
901 return joint_description;
902 }
903
904 // Caller needs ResourceMark
905 // class_in_module_of_loader provides a standard way to include
906 // relevant information about a class, such as its module name as
907 // well as its class loader's name_and_id, in error messages and logging.
908 // Format:
909 // <fully-qualified-external-class-name> is in module <module-name>[@<version>]
910 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
911 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const {
912 // 1. fully qualified external name of class
913 const char* klass_name = external_name();
914 size_t len = strlen(klass_name) + 1;
915
916 // 2. module name + @version
917 const char* module_name = "";
918 const char* version = "";
919 bool has_version = false;
920 bool module_is_named = false;
921 const char* module_name_phrase = "";
922 const Klass* bottom_klass = is_objArray_klass() ?
923 ObjArrayKlass::cast(this)->bottom_klass() : this;
924 if (bottom_klass->is_instance_klass()) {
925 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module();
926 if (module->is_named()) {
927 module_is_named = true;
928 module_name_phrase = "module ";
929 module_name = module->name()->as_C_string();
930 len += strlen(module_name);
931 // Use version if exists and is not a jdk module
932 if (module->should_show_version()) {
933 has_version = true;
934 version = module->version()->as_C_string();
935 // Include stlen(version) + 1 for the "@"
936 len += strlen(version) + 1;
937 }
938 } else {
939 module_name = UNNAMED_MODULE;
940 len += UNNAMED_MODULE_LEN;
941 }
942 } else {
943 // klass is an array of primitives, module is java.base
944 module_is_named = true;
945 module_name_phrase = "module ";
946 module_name = JAVA_BASE_NAME;
947 len += JAVA_BASE_NAME_LEN;
948 }
949
950 // 3. class loader's name_and_id
951 ClassLoaderData* cld = class_loader_data();
952 assert(cld != NULL, "class_loader_data should not be null");
953 const char* loader_name_and_id = cld->loader_name_and_id();
954 len += strlen(loader_name_and_id);
955
956 // 4. include parent loader information
957 const char* parent_loader_phrase = "";
958 const char* parent_loader_name_and_id = "";
959 if (include_parent_loader &&
960 !cld->is_builtin_class_loader_data()) {
961 oop parent_loader = java_lang_ClassLoader::parent(class_loader());
962 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data_or_null(parent_loader);
963 // The parent loader's ClassLoaderData could be null if it is
964 // a delegating class loader that has never defined a class.
965 // In this case the loader's name must be obtained via the parent loader's oop.
966 if (parent_cld == NULL) {
967 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader);
968 if (cl_name_and_id != NULL) {
969 parent_loader_name_and_id = java_lang_String::as_utf8_string(cl_name_and_id);
970 }
971 } else {
972 parent_loader_name_and_id = parent_cld->loader_name_and_id();
973 }
974 parent_loader_phrase = ", parent loader ";
975 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id);
976 }
977
978 // Start to construct final full class description string
979 len += ((use_are) ? strlen(" are in ") : strlen(" is in "));
980 len += strlen(module_name_phrase) + strlen(" of loader ");
981
982 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
983
984 // Just return the FQN if error when allocating string
985 if (class_description == NULL) {
986 return klass_name;
987 }
988
989 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s",
990 klass_name,
991 (use_are) ? "are" : "is",
992 module_name_phrase,
993 module_name,
994 (has_version) ? "@" : "",
995 (has_version) ? version : "",
996 loader_name_and_id,
997 parent_loader_phrase,
998 parent_loader_name_and_id);
999
1000 return class_description;
1001 }