1 /*
2 * Copyright (c) 1997, 2018, 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/systemDictionary.hpp"
31 #include "classfile/vmSymbols.hpp"
32 #include "gc/shared/collectedHeap.inline.hpp"
33 #include "logging/log.hpp"
34 #include "memory/heapInspection.hpp"
35 #include "memory/heapShared.hpp"
36 #include "memory/metadataFactory.hpp"
37 #include "memory/metaspaceClosure.hpp"
38 #include "memory/metaspaceShared.hpp"
39 #include "memory/oopFactory.hpp"
40 #include "memory/resourceArea.hpp"
41 #include "oops/compressedOops.inline.hpp"
42 #include "oops/instanceKlass.hpp"
43 #include "oops/klass.inline.hpp"
44 #include "oops/oop.inline.hpp"
45 #include "oops/oopHandle.inline.hpp"
46 #include "runtime/atomic.hpp"
47 #include "runtime/handles.inline.hpp"
48 #include "runtime/orderAccess.hpp"
49 #include "utilities/macros.hpp"
50 #include "utilities/stack.inline.hpp"
51
52 void Klass::set_java_mirror(Handle m) {
53 assert(!m.is_null(), "New mirror should never be null.");
54 assert(_java_mirror.resolve() == NULL, "should only be used to initialize mirror");
55 _java_mirror = class_loader_data()->add_handle(m);
56 }
57
58 oop Klass::java_mirror() const {
59 return _java_mirror.resolve();
60 }
61
62 bool Klass::is_cloneable() const {
63 return _access_flags.is_cloneable_fast() ||
64 is_subtype_of(SystemDictionary::Cloneable_klass());
65 }
66
67 void Klass::set_is_cloneable() {
68 if (name() == vmSymbols::java_lang_invoke_MemberName()) {
69 assert(is_final(), "no subclasses allowed");
70 // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
71 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) {
72 // Reference cloning should not be intrinsified and always happen in JVM_Clone.
73 } else {
74 _access_flags.set_is_cloneable_fast();
75 }
76 }
77
78 void Klass::set_name(Symbol* n) {
79 _name = n;
80 if (_name != NULL) _name->increment_refcount();
81 }
82
83 bool Klass::is_subclass_of(const Klass* k) const {
84 // Run up the super chain and check
85 if (this == k) return true;
86
87 Klass* t = const_cast<Klass*>(this)->super();
88
89 while (t != NULL) {
90 if (t == k) return true;
91 t = t->super();
92 }
93 return false;
94 }
95
96 bool Klass::search_secondary_supers(Klass* k) const {
97 // Put some extra logic here out-of-line, before the search proper.
98 // This cuts down the size of the inline method.
99
100 // This is necessary, since I am never in my own secondary_super list.
101 if (this == k)
102 return true;
103 // Scan the array-of-objects for a match
104 int cnt = secondary_supers()->length();
105 for (int i = 0; i < cnt; i++) {
106 if (secondary_supers()->at(i) == k) {
107 ((Klass*)this)->set_secondary_super_cache(k);
108 return true;
109 }
110 }
111 return false;
112 }
113
114 // Return self, except for abstract classes with exactly 1
115 // implementor. Then return the 1 concrete implementation.
116 Klass *Klass::up_cast_abstract() {
117 Klass *r = this;
118 while( r->is_abstract() ) { // Receiver is abstract?
119 Klass *s = r->subklass(); // Check for exactly 1 subklass
120 if( !s || s->next_sibling() ) // Oops; wrong count; give up
121 return this; // Return 'this' as a no-progress flag
122 r = s; // Loop till find concrete class
123 }
124 return r; // Return the 1 concrete class
125 }
126
127 // Find LCA in class hierarchy
128 Klass *Klass::LCA( Klass *k2 ) {
129 Klass *k1 = this;
130 while( 1 ) {
131 if( k1->is_subtype_of(k2) ) return k2;
132 if( k2->is_subtype_of(k1) ) return k1;
133 k1 = k1->super();
134 k2 = k2->super();
135 }
136 }
137
138
139 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
140 ResourceMark rm(THREAD);
141 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
142 : vmSymbols::java_lang_InstantiationException(), external_name());
143 }
144
145
146 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
147 ResourceMark rm(THREAD);
148 assert(s != NULL, "Throw NPE!");
149 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(),
150 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name()));
151 }
152
153
154 void Klass::initialize(TRAPS) {
155 ShouldNotReachHere();
156 }
157
158 bool Klass::compute_is_subtype_of(Klass* k) {
159 assert(k->is_klass(), "argument must be a class");
160 return is_subclass_of(k);
161 }
162
163 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
164 #ifdef ASSERT
165 tty->print_cr("Error: find_field called on a klass oop."
166 " Likely error: reflection method does not correctly"
167 " wrap return value in a mirror object.");
168 #endif
169 ShouldNotReachHere();
170 return NULL;
171 }
172
173 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature,
174 OverpassLookupMode overpass_mode,
175 PrivateLookupMode private_mode) const {
176 #ifdef ASSERT
177 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
178 " Likely error: reflection method does not correctly"
179 " wrap return value in a mirror object.");
180 #endif
181 ShouldNotReachHere();
182 return NULL;
183 }
184
185 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
186 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
187 }
188
189 // "Normal" instantiation is preceeded by a MetaspaceObj allocation
190 // which zeros out memory - calloc equivalent.
191 // The constructor is also used from CppVtableCloner,
192 // which doesn't zero out the memory before calling the constructor.
193 // Need to set the _java_mirror field explicitly to not hit an assert that the field
194 // should be NULL before setting it.
195 Klass::Klass(KlassID id) : _id(id),
196 _java_mirror(NULL),
197 _prototype_header(markOopDesc::prototype()),
198 _shared_class_path_index(-1) {
199 CDS_ONLY(_shared_class_flags = 0;)
200 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;)
201 _primary_supers[0] = this;
202 set_super_check_offset(in_bytes(primary_supers_offset()));
203 }
204
205 jint Klass::array_layout_helper(BasicType etype) {
206 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
207 // Note that T_ARRAY is not allowed here.
208 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
209 int esize = type2aelembytes(etype);
210 bool isobj = (etype == T_OBJECT);
211 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
212 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
213
214 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
215 assert(layout_helper_is_array(lh), "correct kind");
216 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
217 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
218 assert(layout_helper_header_size(lh) == hsize, "correct decode");
219 assert(layout_helper_element_type(lh) == etype, "correct decode");
220 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
221
222 return lh;
223 }
224
225 bool Klass::can_be_primary_super_slow() const {
226 if (super() == NULL)
227 return true;
228 else if (super()->super_depth() >= primary_super_limit()-1)
229 return false;
230 else
231 return true;
232 }
233
234 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) {
235 if (FastSuperclassLimit == 0) {
236 // None of the other machinery matters.
237 set_super(k);
238 return;
239 }
240 if (k == NULL) {
241 set_super(NULL);
242 _primary_supers[0] = this;
243 assert(super_depth() == 0, "Object must already be initialized properly");
244 } else if (k != super() || k == SystemDictionary::Object_klass()) {
245 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
246 "initialize this only once to a non-trivial value");
247 set_super(k);
248 Klass* sup = k;
249 int sup_depth = sup->super_depth();
250 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
251 if (!can_be_primary_super_slow())
252 my_depth = primary_super_limit();
253 for (juint i = 0; i < my_depth; i++) {
254 _primary_supers[i] = sup->_primary_supers[i];
255 }
256 Klass* *super_check_cell;
257 if (my_depth < primary_super_limit()) {
258 _primary_supers[my_depth] = this;
259 super_check_cell = &_primary_supers[my_depth];
260 } else {
261 // Overflow of the primary_supers array forces me to be secondary.
262 super_check_cell = &_secondary_super_cache;
263 }
264 set_super_check_offset((address)super_check_cell - (address) this);
265
266 #ifdef ASSERT
267 {
268 juint j = super_depth();
269 assert(j == my_depth, "computed accessor gets right answer");
270 Klass* t = this;
271 while (!t->can_be_primary_super()) {
272 t = t->super();
273 j = t->super_depth();
274 }
275 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
276 assert(primary_super_of_depth(j1) == NULL, "super list padding");
277 }
278 while (t != NULL) {
279 assert(primary_super_of_depth(j) == t, "super list initialization");
280 t = t->super();
281 --j;
282 }
283 assert(j == (juint)-1, "correct depth count");
284 }
285 #endif
286 }
287
288 if (secondary_supers() == NULL) {
289
290 // Now compute the list of secondary supertypes.
291 // Secondaries can occasionally be on the super chain,
292 // if the inline "_primary_supers" array overflows.
293 int extras = 0;
294 Klass* p;
295 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
296 ++extras;
297 }
298
299 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
300
301 // Compute the "real" non-extra secondaries.
302 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces);
303 if (secondaries == NULL) {
304 // secondary_supers set by compute_secondary_supers
305 return;
306 }
307
308 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
309
310 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
311 int i; // Scan for overflow primaries being duplicates of 2nd'arys
312
313 // This happens frequently for very deeply nested arrays: the
314 // primary superclass chain overflows into the secondary. The
315 // secondary list contains the element_klass's secondaries with
316 // an extra array dimension added. If the element_klass's
317 // secondary list already contains some primary overflows, they
318 // (with the extra level of array-ness) will collide with the
319 // normal primary superclass overflows.
320 for( i = 0; i < secondaries->length(); i++ ) {
321 if( secondaries->at(i) == p )
322 break;
323 }
324 if( i < secondaries->length() )
325 continue; // It's a dup, don't put it in
326 primaries->push(p);
327 }
328 // Combine the two arrays into a metadata object to pack the array.
329 // The primaries are added in the reverse order, then the secondaries.
330 int new_length = primaries->length() + secondaries->length();
331 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
332 class_loader_data(), new_length, CHECK);
333 int fill_p = primaries->length();
334 for (int j = 0; j < fill_p; j++) {
335 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
336 }
337 for( int j = 0; j < secondaries->length(); j++ ) {
338 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
339 }
340
341 #ifdef ASSERT
342 // We must not copy any NULL placeholders left over from bootstrap.
343 for (int j = 0; j < s2->length(); j++) {
344 assert(s2->at(j) != NULL, "correct bootstrapping order");
345 }
346 #endif
347
348 set_secondary_supers(s2);
349 }
350 }
351
352 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots,
353 Array<InstanceKlass*>* transitive_interfaces) {
354 assert(num_extra_slots == 0, "override for complex klasses");
355 assert(transitive_interfaces == NULL, "sanity");
356 set_secondary_supers(Universe::the_empty_klass_array());
357 return NULL;
358 }
359
360
361 InstanceKlass* Klass::superklass() const {
362 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
363 return _super == NULL ? NULL : InstanceKlass::cast(_super);
364 }
365
366 void Klass::set_subklass(Klass* s) {
367 assert(s != this, "sanity check");
368 _subklass = s;
369 }
370
371 void Klass::set_next_sibling(Klass* s) {
372 assert(s != this, "sanity check");
373 _next_sibling = s;
374 }
375
376 void Klass::append_to_sibling_list() {
377 debug_only(verify();)
378 // add ourselves to superklass' subklass list
379 InstanceKlass* super = superklass();
380 if (super == NULL) return; // special case: class Object
381 assert((!super->is_interface() // interfaces cannot be supers
382 && (super->superklass() == NULL || !is_interface())),
383 "an interface can only be a subklass of Object");
384 Klass* prev_first_subklass = super->subklass();
385 if (prev_first_subklass != NULL) {
386 // set our sibling to be the superklass' previous first subklass
387 set_next_sibling(prev_first_subklass);
388 }
389 // make ourselves the superklass' first subklass
390 super->set_subklass(this);
391 debug_only(verify();)
392 }
393
394 oop Klass::holder_phantom() const {
395 return class_loader_data()->holder_phantom();
396 }
397
398 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
399 if (!ClassUnloading || !unloading_occurred) {
400 return;
401 }
402
403 Klass* root = SystemDictionary::Object_klass();
404 Stack<Klass*, mtGC> stack;
405
406 stack.push(root);
407 while (!stack.is_empty()) {
408 Klass* current = stack.pop();
409
410 assert(current->is_loader_alive(), "just checking, this should be live");
411
412 // Find and set the first alive subklass
413 Klass* sub = current->subklass();
414 while (sub != NULL && !sub->is_loader_alive()) {
415 #ifndef PRODUCT
416 if (log_is_enabled(Trace, class, unload)) {
417 ResourceMark rm;
418 log_trace(class, unload)("unlinking class (subclass): %s", sub->external_name());
419 }
420 #endif
421 sub = sub->next_sibling();
422 }
423 current->set_subklass(sub);
424 if (sub != NULL) {
425 stack.push(sub);
426 }
427
428 // Find and set the first alive sibling
429 Klass* sibling = current->next_sibling();
430 while (sibling != NULL && !sibling->is_loader_alive()) {
431 if (log_is_enabled(Trace, class, unload)) {
432 ResourceMark rm;
433 log_trace(class, unload)("[Unlinking class (sibling) %s]", sibling->external_name());
434 }
435 sibling = sibling->next_sibling();
436 }
437 current->set_next_sibling(sibling);
438 if (sibling != NULL) {
439 stack.push(sibling);
440 }
441
442 // Clean the implementors list and method data.
443 if (clean_alive_klasses && current->is_instance_klass()) {
444 InstanceKlass* ik = InstanceKlass::cast(current);
445 ik->clean_weak_instanceklass_links();
446
447 // JVMTI RedefineClasses creates previous versions that are not in
448 // the class hierarchy, so process them here.
449 while ((ik = ik->previous_versions()) != NULL) {
450 ik->clean_weak_instanceklass_links();
451 }
452 }
453 }
454 }
455
456 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
457 if (log_is_enabled(Trace, cds)) {
458 ResourceMark rm;
459 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
460 }
461
462 it->push(&_name);
463 it->push(&_secondary_super_cache);
464 it->push(&_secondary_supers);
465 for (int i = 0; i < _primary_super_limit; i++) {
466 it->push(&_primary_supers[i]);
467 }
468 it->push(&_super);
469 it->push(&_subklass);
470 it->push(&_next_sibling);
471 it->push(&_next_link);
472
473 vtableEntry* vt = start_of_vtable();
474 for (int i=0; i<vtable_length(); i++) {
475 it->push(vt[i].method_addr());
476 }
477 }
478
479 void Klass::remove_unshareable_info() {
480 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
481 JFR_ONLY(REMOVE_ID(this);)
482 if (log_is_enabled(Trace, cds, unshareable)) {
483 ResourceMark rm;
484 log_trace(cds, unshareable)("remove: %s", external_name());
485 }
486
487 set_subklass(NULL);
488 set_next_sibling(NULL);
489 set_next_link(NULL);
490
491 // Null out class_loader_data because we don't share that yet.
492 set_class_loader_data(NULL);
493 set_is_shared();
494 }
495
496 void Klass::remove_java_mirror() {
497 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
498 if (log_is_enabled(Trace, cds, unshareable)) {
499 ResourceMark rm;
500 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
501 }
502 // Just null out the mirror. The class_loader_data() no longer exists.
503 _java_mirror = NULL;
504 }
505
506 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
507 assert(is_klass(), "ensure C++ vtable is restored");
508 assert(is_shared(), "must be set");
509 JFR_ONLY(RESTORE_ID(this);)
510 if (log_is_enabled(Trace, cds, unshareable)) {
511 ResourceMark rm;
512 log_trace(cds, unshareable)("restore: %s", external_name());
513 }
514
515 // If an exception happened during CDS restore, some of these fields may already be
516 // set. We leave the class on the CLD list, even if incomplete so that we don't
517 // modify the CLD list outside a safepoint.
518 if (class_loader_data() == NULL) {
519 // Restore class_loader_data to the null class loader data
520 set_class_loader_data(loader_data);
521
522 // Add to null class loader list first before creating the mirror
523 // (same order as class file parsing)
524 loader_data->add_class(this);
525 }
526
527 Handle loader(THREAD, loader_data->class_loader());
528 ModuleEntry* module_entry = NULL;
529 Klass* k = this;
530 if (k->is_objArray_klass()) {
531 k = ObjArrayKlass::cast(k)->bottom_klass();
532 }
533 // Obtain klass' module.
534 if (k->is_instance_klass()) {
535 InstanceKlass* ik = (InstanceKlass*) k;
536 module_entry = ik->module();
537 } else {
538 module_entry = ModuleEntryTable::javabase_moduleEntry();
539 }
540 // Obtain java.lang.Module, if available
541 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
542
543 if (this->has_raw_archived_mirror()) {
544 ResourceMark rm;
545 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
546 if (HeapShared::open_archive_heap_region_mapped()) {
547 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle,
548 protection_domain,
549 CHECK);
550 if (present) {
551 return;
552 }
553 }
554
555 // No archived mirror data
556 log_debug(cds, mirror)("No archived mirror data for %s", external_name());
557 _java_mirror = NULL;
558 this->clear_has_raw_archived_mirror();
559 }
560
561 // Only recreate it if not present. A previous attempt to restore may have
562 // gotten an OOM later but keep the mirror if it was created.
563 if (java_mirror() == NULL) {
564 log_trace(cds, mirror)("Recreate mirror for %s", external_name());
565 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
566 }
567 }
568
569 #if INCLUDE_CDS_JAVA_HEAP
570 // Used at CDS dump time to access the archived mirror. No GC barrier.
571 oop Klass::archived_java_mirror_raw() {
572 assert(has_raw_archived_mirror(), "must have raw archived mirror");
573 return CompressedOops::decode(_archived_mirror);
574 }
575
576 narrowOop Klass::archived_java_mirror_raw_narrow() {
577 assert(has_raw_archived_mirror(), "must have raw archived mirror");
578 return _archived_mirror;
579 }
580
581 // No GC barrier
582 void Klass::set_archived_java_mirror_raw(oop m) {
583 assert(DumpSharedSpaces, "called only during runtime");
584 _archived_mirror = CompressedOops::encode(m);
585 }
586 #endif // INCLUDE_CDS_JAVA_HEAP
587
588 Klass* Klass::array_klass_or_null(int rank) {
589 EXCEPTION_MARK;
590 // No exception can be thrown by array_klass_impl when called with or_null == true.
591 // (In anycase, the execption mark will fail if it do so)
592 return array_klass_impl(true, rank, THREAD);
593 }
594
595
596 Klass* Klass::array_klass_or_null() {
597 EXCEPTION_MARK;
598 // No exception can be thrown by array_klass_impl when called with or_null == true.
599 // (In anycase, the execption mark will fail if it do so)
600 return array_klass_impl(true, THREAD);
601 }
602
603
604 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
605 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
606 return NULL;
607 }
608
609
610 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
611 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
612 return NULL;
613 }
614
615 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) {
616 if (length > max_length) {
617 if (!THREAD->in_retryable_allocation()) {
618 report_java_out_of_memory("Requested array size exceeds VM limit");
619 JvmtiExport::post_array_size_exhausted();
620 THROW_OOP(Universe::out_of_memory_error_array_size());
621 } else {
622 THROW_OOP(Universe::out_of_memory_error_retry());
623 }
624 } else if (length < 0) {
625 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length));
626 }
627 }
628
629 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
630
631 // In product mode, this function doesn't have virtual function calls so
632 // there might be some performance advantage to handling InstanceKlass here.
633 const char* Klass::external_name() const {
634 if (is_instance_klass()) {
635 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
636 if (ik->is_unsafe_anonymous()) {
637 char addr_buf[20];
638 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
639 size_t addr_len = strlen(addr_buf);
640 size_t name_len = name()->utf8_length();
641 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
642 name()->as_klass_external_name(result, (int) name_len + 1);
643 assert(strlen(result) == name_len, "");
644 strcpy(result + name_len, addr_buf);
645 assert(strlen(result) == name_len + addr_len, "");
646 return result;
647 }
648 }
649 if (name() == NULL) return "<unknown>";
650 return name()->as_klass_external_name();
651 }
652
653 const char* Klass::signature_name() const {
654 if (name() == NULL) return "<unknown>";
655 return name()->as_C_string();
656 }
657
658 const char* Klass::external_kind() const {
659 if (is_interface()) return "interface";
660 if (is_abstract()) return "abstract class";
661 return "class";
662 }
663
664 // Unless overridden, modifier_flags is 0.
665 jint Klass::compute_modifier_flags(TRAPS) const {
666 return 0;
667 }
668
669 int Klass::atomic_incr_biased_lock_revocation_count() {
670 return (int) Atomic::add(1, &_biased_lock_revocation_count);
671 }
672
673 // Unless overridden, jvmti_class_status has no flags set.
674 jint Klass::jvmti_class_status() const {
675 return 0;
676 }
677
678
679 // Printing
680
681 void Klass::print_on(outputStream* st) const {
682 ResourceMark rm;
683 // print title
684 st->print("%s", internal_name());
685 print_address_on(st);
686 st->cr();
687 }
688
689 void Klass::oop_print_on(oop obj, outputStream* st) {
690 ResourceMark rm;
691 // print title
692 st->print_cr("%s ", internal_name());
693 obj->print_address_on(st);
694
695 if (WizardMode) {
696 // print header
697 obj->mark()->print_on(st);
698 }
699
700 // print class
701 st->print(" - klass: ");
702 obj->klass()->print_value_on(st);
703 st->cr();
704 }
705
706 void Klass::oop_print_value_on(oop obj, outputStream* st) {
707 // print title
708 ResourceMark rm; // Cannot print in debug mode without this
709 st->print("%s", internal_name());
710 obj->print_address_on(st);
711 }
712
713 #if INCLUDE_SERVICES
714 // Size Statistics
715 void Klass::collect_statistics(KlassSizeStats *sz) const {
716 sz->_klass_bytes = sz->count(this);
717 sz->_mirror_bytes = sz->count(java_mirror());
718 sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
719
720 sz->_ro_bytes += sz->_secondary_supers_bytes;
721 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
722 }
723 #endif // INCLUDE_SERVICES
724
725 // Verification
726
727 void Klass::verify_on(outputStream* st) {
728
729 // This can be expensive, but it is worth checking that this klass is actually
730 // in the CLD graph but not in production.
731 assert(Metaspace::contains((address)this), "Should be");
732
733 guarantee(this->is_klass(),"should be klass");
734
735 if (super() != NULL) {
736 guarantee(super()->is_klass(), "should be klass");
737 }
738 if (secondary_super_cache() != NULL) {
739 Klass* ko = secondary_super_cache();
740 guarantee(ko->is_klass(), "should be klass");
741 }
742 for ( uint i = 0; i < primary_super_limit(); i++ ) {
743 Klass* ko = _primary_supers[i];
744 if (ko != NULL) {
745 guarantee(ko->is_klass(), "should be klass");
746 }
747 }
748
749 if (java_mirror() != NULL) {
750 guarantee(oopDesc::is_oop(java_mirror()), "should be instance");
751 }
752 }
753
754 void Klass::oop_verify_on(oop obj, outputStream* st) {
755 guarantee(oopDesc::is_oop(obj), "should be oop");
756 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
757 }
758
759 Klass* Klass::decode_klass_raw(narrowKlass narrow_klass) {
760 return (Klass*)(void*)( (uintptr_t)Universe::narrow_klass_base() +
761 ((uintptr_t)narrow_klass << Universe::narrow_klass_shift()));
762 }
763
764 bool Klass::is_valid(Klass* k) {
765 if (!is_aligned(k, sizeof(MetaWord))) return false;
766 if ((size_t)k < os::min_page_size()) return false;
767
768 if (!os::is_readable_range(k, k + 1)) return false;
769 if (!MetaspaceUtils::is_range_in_committed(k, k + 1)) return false;
770
771 if (!Symbol::is_valid(k->name())) return false;
772 return ClassLoaderDataGraph::is_valid(k->class_loader_data());
773 }
774
775 klassVtable Klass::vtable() const {
776 return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size());
777 }
778
779 vtableEntry* Klass::start_of_vtable() const {
780 return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset()));
781 }
782
783 Method* Klass::method_at_vtable(int index) {
784 #ifndef PRODUCT
785 assert(index >= 0, "valid vtable index");
786 if (DebugVtables) {
787 verify_vtable_index(index);
788 }
789 #endif
790 return start_of_vtable()[index].method();
791 }
792
793 ByteSize Klass::vtable_start_offset() {
794 return in_ByteSize(InstanceKlass::header_size() * wordSize);
795 }
796
797 #ifndef PRODUCT
798
799 bool Klass::verify_vtable_index(int i) {
800 int limit = vtable_length()/vtableEntry::size();
801 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
802 return true;
803 }
804
805 #endif // PRODUCT
806
807 // Caller needs ResourceMark
808 // joint_in_module_of_loader provides an optimization if 2 classes are in
809 // the same module to succinctly print out relevant information about their
810 // module name and class loader's name_and_id for error messages.
811 // Format:
812 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2>
813 // are in module <module-name>[@<version>]
814 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
815 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const {
816 assert(module() == class2->module(), "classes do not have the same module");
817 const char* class1_name = external_name();
818 size_t len = strlen(class1_name) + 1;
819
820 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader);
821 len += strlen(class2_description);
822
823 len += strlen(" and ");
824
825 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
826
827 // Just return the FQN if error when allocating string
828 if (joint_description == NULL) {
829 return class1_name;
830 }
831
832 jio_snprintf(joint_description, len, "%s and %s",
833 class1_name,
834 class2_description);
835
836 return joint_description;
837 }
838
839 // Caller needs ResourceMark
840 // class_in_module_of_loader provides a standard way to include
841 // relevant information about a class, such as its module name as
842 // well as its class loader's name_and_id, in error messages and logging.
843 // Format:
844 // <fully-qualified-external-class-name> is in module <module-name>[@<version>]
845 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
846 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const {
847 // 1. fully qualified external name of class
848 const char* klass_name = external_name();
849 size_t len = strlen(klass_name) + 1;
850
851 // 2. module name + @version
852 const char* module_name = "";
853 const char* version = "";
854 bool has_version = false;
855 bool module_is_named = false;
856 const char* module_name_phrase = "";
857 const Klass* bottom_klass = is_objArray_klass() ?
858 ObjArrayKlass::cast(this)->bottom_klass() : this;
859 if (bottom_klass->is_instance_klass()) {
860 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module();
861 if (module->is_named()) {
862 module_is_named = true;
863 module_name_phrase = "module ";
864 module_name = module->name()->as_C_string();
865 len += strlen(module_name);
866 // Use version if exists and is not a jdk module
867 if (module->should_show_version()) {
868 has_version = true;
869 version = module->version()->as_C_string();
870 // Include stlen(version) + 1 for the "@"
871 len += strlen(version) + 1;
872 }
873 } else {
874 module_name = UNNAMED_MODULE;
875 len += UNNAMED_MODULE_LEN;
876 }
877 } else {
878 // klass is an array of primitives, module is java.base
879 module_is_named = true;
880 module_name_phrase = "module ";
881 module_name = JAVA_BASE_NAME;
882 len += JAVA_BASE_NAME_LEN;
883 }
884
885 // 3. class loader's name_and_id
886 ClassLoaderData* cld = class_loader_data();
887 assert(cld != NULL, "class_loader_data should not be null");
888 const char* loader_name_and_id = cld->loader_name_and_id();
889 len += strlen(loader_name_and_id);
890
891 // 4. include parent loader information
892 const char* parent_loader_phrase = "";
893 const char* parent_loader_name_and_id = "";
894 if (include_parent_loader &&
895 !cld->is_builtin_class_loader_data()) {
896 oop parent_loader = java_lang_ClassLoader::parent(class_loader());
897 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data(parent_loader);
898 assert(parent_cld != NULL, "parent's class loader data should not be null");
899 parent_loader_name_and_id = parent_cld->loader_name_and_id();
900 parent_loader_phrase = ", parent loader ";
901 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id);
902 }
903
904 // Start to construct final full class description string
905 len += ((use_are) ? strlen(" are in ") : strlen(" is in "));
906 len += strlen(module_name_phrase) + strlen(" of loader ");
907
908 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
909
910 // Just return the FQN if error when allocating string
911 if (class_description == NULL) {
912 return klass_name;
913 }
914
915 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s",
916 klass_name,
917 (use_are) ? "are" : "is",
918 module_name_phrase,
919 module_name,
920 (has_version) ? "@" : "",
921 (has_version) ? version : "",
922 loader_name_and_id,
923 parent_loader_phrase,
924 parent_loader_name_and_id);
925
926 return class_description;
927 }