1 /*
2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoaderData.inline.hpp"
27 #include "classfile/classLoaderDataGraph.inline.hpp"
28 #include "classfile/dictionary.hpp"
29 #include "classfile/javaClasses.hpp"
30 #include "classfile/moduleEntry.hpp"
31 #include "classfile/systemDictionary.hpp"
32 #include "classfile/vmSymbols.hpp"
33 #include "gc/shared/collectedHeap.inline.hpp"
34 #include "logging/log.hpp"
35 #include "memory/heapInspection.hpp"
36 #include "memory/heapShared.hpp"
37 #include "memory/metadataFactory.hpp"
38 #include "memory/metaspaceClosure.hpp"
39 #include "memory/metaspaceShared.hpp"
40 #include "memory/oopFactory.hpp"
41 #include "memory/resourceArea.hpp"
42 #include "memory/universe.hpp"
43 #include "oops/compressedOops.inline.hpp"
44 #include "oops/instanceKlass.hpp"
45 #include "oops/klass.inline.hpp"
46 #include "oops/oop.inline.hpp"
47 #include "oops/oopHandle.inline.hpp"
48 #include "runtime/atomic.hpp"
49 #include "runtime/handles.inline.hpp"
50 #include "utilities/macros.hpp"
51 #include "utilities/stack.inline.hpp"
52
53 void Klass::set_java_mirror(Handle m) {
54 assert(!m.is_null(), "New mirror should never be null.");
55 assert(_java_mirror.resolve() == NULL, "should only be used to initialize mirror");
56 _java_mirror = class_loader_data()->add_handle(m);
57 }
58
59 oop Klass::java_mirror_no_keepalive() const {
60 return _java_mirror.peek();
61 }
62
63 bool Klass::is_cloneable() const {
64 return _access_flags.is_cloneable_fast() ||
65 is_subtype_of(SystemDictionary::Cloneable_klass());
66 }
67
68 void Klass::set_is_cloneable() {
69 if (name() == vmSymbols::java_lang_invoke_MemberName()) {
70 assert(is_final(), "no subclasses allowed");
71 // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
72 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) {
73 // Reference cloning should not be intrinsified and always happen in JVM_Clone.
74 } else {
75 _access_flags.set_is_cloneable_fast();
76 }
77 }
78
79 void Klass::set_name(Symbol* n) {
80 _name = n;
81 if (_name != NULL) _name->increment_refcount();
82 }
83
84 bool Klass::is_subclass_of(const Klass* k) const {
85 // Run up the super chain and check
86 if (this == k) return true;
87
88 Klass* t = const_cast<Klass*>(this)->super();
89
90 while (t != NULL) {
91 if (t == k) return true;
92 t = t->super();
93 }
94 return false;
95 }
96
97 bool Klass::search_secondary_supers(Klass* k) const {
98 // Put some extra logic here out-of-line, before the search proper.
99 // This cuts down the size of the inline method.
100
101 // This is necessary, since I am never in my own secondary_super list.
102 if (this == k)
103 return true;
104 // Scan the array-of-objects for a match
105 int cnt = secondary_supers()->length();
106 for (int i = 0; i < cnt; i++) {
107 if (secondary_supers()->at(i) == k) {
108 ((Klass*)this)->set_secondary_super_cache(k);
109 return true;
110 }
111 }
112 return false;
113 }
114
115 // Return self, except for abstract classes with exactly 1
116 // implementor. Then return the 1 concrete implementation.
117 Klass *Klass::up_cast_abstract() {
118 Klass *r = this;
119 while( r->is_abstract() ) { // Receiver is abstract?
120 Klass *s = r->subklass(); // Check for exactly 1 subklass
121 if (s == NULL || s->next_sibling() != NULL) // Oops; wrong count; give up
122 return this; // Return 'this' as a no-progress flag
123 r = s; // Loop till find concrete class
124 }
125 return r; // Return the 1 concrete class
126 }
127
128 // Find LCA in class hierarchy
129 Klass *Klass::LCA( Klass *k2 ) {
130 Klass *k1 = this;
131 while( 1 ) {
132 if( k1->is_subtype_of(k2) ) return k2;
133 if( k2->is_subtype_of(k1) ) return k1;
134 k1 = k1->super();
135 k2 = k2->super();
136 }
137 }
138
139
140 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
141 ResourceMark rm(THREAD);
142 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
143 : vmSymbols::java_lang_InstantiationException(), external_name());
144 }
145
146
147 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
148 ResourceMark rm(THREAD);
149 assert(s != NULL, "Throw NPE!");
150 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(),
151 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name()));
152 }
153
154
155 void Klass::initialize(TRAPS) {
156 ShouldNotReachHere();
157 }
158
159 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
160 #ifdef ASSERT
161 tty->print_cr("Error: find_field called on a klass oop."
162 " Likely error: reflection method does not correctly"
163 " wrap return value in a mirror object.");
164 #endif
165 ShouldNotReachHere();
166 return NULL;
167 }
168
169 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature,
170 OverpassLookupMode overpass_mode,
171 PrivateLookupMode private_mode) const {
172 #ifdef ASSERT
173 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
174 " Likely error: reflection method does not correctly"
175 " wrap return value in a mirror object.");
176 #endif
177 ShouldNotReachHere();
178 return NULL;
179 }
180
181 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
182 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
183 }
184
185 // "Normal" instantiation is preceeded by a MetaspaceObj allocation
186 // which zeros out memory - calloc equivalent.
187 // The constructor is also used from CppVtableCloner,
188 // which doesn't zero out the memory before calling the constructor.
189 // Need to set the _java_mirror field explicitly to not hit an assert that the field
190 // should be NULL before setting it.
191 Klass::Klass(KlassID id) : _id(id),
192 _java_mirror(NULL),
193 _prototype_header(markWord::prototype()),
194 _shared_class_path_index(-1) {
195 CDS_ONLY(_shared_class_flags = 0;)
196 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;)
197 _primary_supers[0] = this;
198 set_super_check_offset(in_bytes(primary_supers_offset()));
199 }
200
201 jint Klass::array_layout_helper(BasicType etype) {
202 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
203 // Note that T_ARRAY is not allowed here.
204 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
205 int esize = type2aelembytes(etype);
206 bool isobj = (etype == T_OBJECT);
207 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
208 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
209
210 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
211 assert(layout_helper_is_array(lh), "correct kind");
212 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
213 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
214 assert(layout_helper_header_size(lh) == hsize, "correct decode");
215 assert(layout_helper_element_type(lh) == etype, "correct decode");
216 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
217
218 return lh;
219 }
220
221 bool Klass::can_be_primary_super_slow() const {
222 if (super() == NULL)
223 return true;
224 else if (super()->super_depth() >= primary_super_limit()-1)
225 return false;
226 else
227 return true;
228 }
229
230 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) {
231 if (k == NULL) {
232 set_super(NULL);
233 _primary_supers[0] = this;
234 assert(super_depth() == 0, "Object must already be initialized properly");
235 } else if (k != super() || k == SystemDictionary::Object_klass()) {
236 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
237 "initialize this only once to a non-trivial value");
238 set_super(k);
239 Klass* sup = k;
240 int sup_depth = sup->super_depth();
241 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
242 if (!can_be_primary_super_slow())
243 my_depth = primary_super_limit();
244 for (juint i = 0; i < my_depth; i++) {
245 _primary_supers[i] = sup->_primary_supers[i];
246 }
247 Klass* *super_check_cell;
248 if (my_depth < primary_super_limit()) {
249 _primary_supers[my_depth] = this;
250 super_check_cell = &_primary_supers[my_depth];
251 } else {
252 // Overflow of the primary_supers array forces me to be secondary.
253 super_check_cell = &_secondary_super_cache;
254 }
255 set_super_check_offset((address)super_check_cell - (address) this);
256
257 #ifdef ASSERT
258 {
259 juint j = super_depth();
260 assert(j == my_depth, "computed accessor gets right answer");
261 Klass* t = this;
262 while (!t->can_be_primary_super()) {
263 t = t->super();
264 j = t->super_depth();
265 }
266 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
267 assert(primary_super_of_depth(j1) == NULL, "super list padding");
268 }
269 while (t != NULL) {
270 assert(primary_super_of_depth(j) == t, "super list initialization");
271 t = t->super();
272 --j;
273 }
274 assert(j == (juint)-1, "correct depth count");
275 }
276 #endif
277 }
278
279 if (secondary_supers() == NULL) {
280
281 // Now compute the list of secondary supertypes.
282 // Secondaries can occasionally be on the super chain,
283 // if the inline "_primary_supers" array overflows.
284 int extras = 0;
285 Klass* p;
286 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
287 ++extras;
288 }
289
290 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
291
292 // Compute the "real" non-extra secondaries.
293 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces);
294 if (secondaries == NULL) {
295 // secondary_supers set by compute_secondary_supers
296 return;
297 }
298
299 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
300
301 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
302 int i; // Scan for overflow primaries being duplicates of 2nd'arys
303
304 // This happens frequently for very deeply nested arrays: the
305 // primary superclass chain overflows into the secondary. The
306 // secondary list contains the element_klass's secondaries with
307 // an extra array dimension added. If the element_klass's
308 // secondary list already contains some primary overflows, they
309 // (with the extra level of array-ness) will collide with the
310 // normal primary superclass overflows.
311 for( i = 0; i < secondaries->length(); i++ ) {
312 if( secondaries->at(i) == p )
313 break;
314 }
315 if( i < secondaries->length() )
316 continue; // It's a dup, don't put it in
317 primaries->push(p);
318 }
319 // Combine the two arrays into a metadata object to pack the array.
320 // The primaries are added in the reverse order, then the secondaries.
321 int new_length = primaries->length() + secondaries->length();
322 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
323 class_loader_data(), new_length, CHECK);
324 int fill_p = primaries->length();
325 for (int j = 0; j < fill_p; j++) {
326 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
327 }
328 for( int j = 0; j < secondaries->length(); j++ ) {
329 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
330 }
331
332 #ifdef ASSERT
333 // We must not copy any NULL placeholders left over from bootstrap.
334 for (int j = 0; j < s2->length(); j++) {
335 assert(s2->at(j) != NULL, "correct bootstrapping order");
336 }
337 #endif
338
339 set_secondary_supers(s2);
340 }
341 }
342
343 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots,
344 Array<InstanceKlass*>* transitive_interfaces) {
345 assert(num_extra_slots == 0, "override for complex klasses");
346 assert(transitive_interfaces == NULL, "sanity");
347 set_secondary_supers(Universe::the_empty_klass_array());
348 return NULL;
349 }
350
351
352 // superklass links
353 InstanceKlass* Klass::superklass() const {
354 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
355 return _super == NULL ? NULL : InstanceKlass::cast(_super);
356 }
357
358 // subklass links. Used by the compiler (and vtable initialization)
359 // May be cleaned concurrently, so must use the Compile_lock.
360 // The log parameter is for clean_weak_klass_links to report unlinked classes.
361 Klass* Klass::subklass(bool log) const {
362 // Need load_acquire on the _subklass, because it races with inserts that
363 // publishes freshly initialized data.
364 for (Klass* chain = Atomic::load_acquire(&_subklass);
365 chain != NULL;
366 // Do not need load_acquire on _next_sibling, because inserts never
367 // create _next_sibling edges to dead data.
368 chain = Atomic::load(&chain->_next_sibling))
369 {
370 if (chain->is_loader_alive()) {
371 return chain;
372 } else if (log) {
373 if (log_is_enabled(Trace, class, unload)) {
374 ResourceMark rm;
375 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name());
376 }
377 }
378 }
379 return NULL;
380 }
381
382 Klass* Klass::next_sibling(bool log) const {
383 // Do not need load_acquire on _next_sibling, because inserts never
384 // create _next_sibling edges to dead data.
385 for (Klass* chain = Atomic::load(&_next_sibling);
386 chain != NULL;
387 chain = Atomic::load(&chain->_next_sibling)) {
388 // Only return alive klass, there may be stale klass
389 // in this chain if cleaned concurrently.
390 if (chain->is_loader_alive()) {
391 return chain;
392 } else if (log) {
393 if (log_is_enabled(Trace, class, unload)) {
394 ResourceMark rm;
395 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name());
396 }
397 }
398 }
399 return NULL;
400 }
401
402 void Klass::set_subklass(Klass* s) {
403 assert(s != this, "sanity check");
404 Atomic::release_store(&_subklass, s);
405 }
406
407 void Klass::set_next_sibling(Klass* s) {
408 assert(s != this, "sanity check");
409 // Does not need release semantics. If used by cleanup, it will link to
410 // already safely published data, and if used by inserts, will be published
411 // safely using cmpxchg.
412 Atomic::store(&_next_sibling, s);
413 }
414
415 void Klass::append_to_sibling_list() {
416 assert_locked_or_safepoint(Compile_lock);
417 debug_only(verify();)
418 // add ourselves to superklass' subklass list
419 InstanceKlass* super = superklass();
420 if (super == NULL) return; // special case: class Object
421 assert((!super->is_interface() // interfaces cannot be supers
422 && (super->superklass() == NULL || !is_interface())),
423 "an interface can only be a subklass of Object");
424
425 // Make sure there is no stale subklass head
426 super->clean_subklass();
427
428 for (;;) {
429 Klass* prev_first_subklass = Atomic::load_acquire(&_super->_subklass);
430 if (prev_first_subklass != NULL) {
431 // set our sibling to be the superklass' previous first subklass
432 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses");
433 set_next_sibling(prev_first_subklass);
434 }
435 // Note that the prev_first_subklass is always alive, meaning no sibling_next links
436 // are ever created to not alive klasses. This is an important invariant of the lock-free
437 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list.
438 if (Atomic::cmpxchg(&super->_subklass, prev_first_subklass, this) == prev_first_subklass) {
439 return;
440 }
441 }
442 debug_only(verify();)
443 }
444
445 void Klass::clean_subklass() {
446 for (;;) {
447 // Need load_acquire, due to contending with concurrent inserts
448 Klass* subklass = Atomic::load_acquire(&_subklass);
449 if (subklass == NULL || subklass->is_loader_alive()) {
450 return;
451 }
452 // Try to fix _subklass until it points at something not dead.
453 Atomic::cmpxchg(&_subklass, subklass, subklass->next_sibling());
454 }
455 }
456
457 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
458 if (!ClassUnloading || !unloading_occurred) {
459 return;
460 }
461
462 Klass* root = SystemDictionary::Object_klass();
463 Stack<Klass*, mtGC> stack;
464
465 stack.push(root);
466 while (!stack.is_empty()) {
467 Klass* current = stack.pop();
468
469 assert(current->is_loader_alive(), "just checking, this should be live");
470
471 // Find and set the first alive subklass
472 Klass* sub = current->subklass(true);
473 current->clean_subklass();
474 if (sub != NULL) {
475 stack.push(sub);
476 }
477
478 // Find and set the first alive sibling
479 Klass* sibling = current->next_sibling(true);
480 current->set_next_sibling(sibling);
481 if (sibling != NULL) {
482 stack.push(sibling);
483 }
484
485 // Clean the implementors list and method data.
486 if (clean_alive_klasses && current->is_instance_klass()) {
487 InstanceKlass* ik = InstanceKlass::cast(current);
488 ik->clean_weak_instanceklass_links();
489
490 // JVMTI RedefineClasses creates previous versions that are not in
491 // the class hierarchy, so process them here.
492 while ((ik = ik->previous_versions()) != NULL) {
493 ik->clean_weak_instanceklass_links();
494 }
495 }
496 }
497 }
498
499 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
500 if (log_is_enabled(Trace, cds)) {
501 ResourceMark rm;
502 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
503 }
504
505 it->push(&_name);
506 it->push(&_secondary_super_cache);
507 it->push(&_secondary_supers);
508 for (int i = 0; i < _primary_super_limit; i++) {
509 it->push(&_primary_supers[i]);
510 }
511 it->push(&_super);
512 it->push((Klass**)&_subklass);
513 it->push((Klass**)&_next_sibling);
514 it->push(&_next_link);
515
516 vtableEntry* vt = start_of_vtable();
517 for (int i=0; i<vtable_length(); i++) {
518 it->push(vt[i].method_addr());
519 }
520 }
521
522 void Klass::remove_unshareable_info() {
523 assert (Arguments::is_dumping_archive(),
524 "only called during CDS dump time");
525 JFR_ONLY(REMOVE_ID(this);)
526 if (log_is_enabled(Trace, cds, unshareable)) {
527 ResourceMark rm;
528 log_trace(cds, unshareable)("remove: %s", external_name());
529 }
530
531 set_subklass(NULL);
532 set_next_sibling(NULL);
533 set_next_link(NULL);
534
535 // Null out class_loader_data because we don't share that yet.
536 set_class_loader_data(NULL);
537 set_is_shared();
538 }
539
540 void Klass::remove_java_mirror() {
541 Arguments::assert_is_dumping_archive();
542 if (log_is_enabled(Trace, cds, unshareable)) {
543 ResourceMark rm;
544 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
545 }
546 // Just null out the mirror. The class_loader_data() no longer exists.
547 _java_mirror = NULL;
548 }
549
550 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
551 assert(is_klass(), "ensure C++ vtable is restored");
552 assert(is_shared(), "must be set");
553 JFR_ONLY(RESTORE_ID(this);)
554 if (log_is_enabled(Trace, cds, unshareable)) {
555 ResourceMark rm;
556 log_trace(cds, unshareable)("restore: %s", external_name());
557 }
558
559 // If an exception happened during CDS restore, some of these fields may already be
560 // set. We leave the class on the CLD list, even if incomplete so that we don't
561 // modify the CLD list outside a safepoint.
562 if (class_loader_data() == NULL) {
563 // Restore class_loader_data to the null class loader data
564 set_class_loader_data(loader_data);
565
566 // Add to null class loader list first before creating the mirror
567 // (same order as class file parsing)
568 loader_data->add_class(this);
569 }
570
571 Handle loader(THREAD, loader_data->class_loader());
572 ModuleEntry* module_entry = NULL;
573 Klass* k = this;
574 if (k->is_objArray_klass()) {
575 k = ObjArrayKlass::cast(k)->bottom_klass();
576 }
577 // Obtain klass' module.
578 if (k->is_instance_klass()) {
579 InstanceKlass* ik = (InstanceKlass*) k;
580 module_entry = ik->module();
581 } else {
582 module_entry = ModuleEntryTable::javabase_moduleEntry();
583 }
584 // Obtain java.lang.Module, if available
585 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
586
587 if (this->has_raw_archived_mirror()) {
588 ResourceMark rm;
589 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
590 if (HeapShared::open_archive_heap_region_mapped()) {
591 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle,
592 protection_domain,
593 CHECK);
594 if (present) {
595 return;
596 }
597 }
598
599 // No archived mirror data
600 log_debug(cds, mirror)("No archived mirror data for %s", external_name());
601 _java_mirror = NULL;
602 this->clear_has_raw_archived_mirror();
603 }
604
605 // Only recreate it if not present. A previous attempt to restore may have
606 // gotten an OOM later but keep the mirror if it was created.
607 if (java_mirror() == NULL) {
608 log_trace(cds, mirror)("Recreate mirror for %s", external_name());
609 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
610 }
611 }
612
613 #if INCLUDE_CDS_JAVA_HEAP
614 // Used at CDS dump time to access the archived mirror. No GC barrier.
615 oop Klass::archived_java_mirror_raw() {
616 assert(has_raw_archived_mirror(), "must have raw archived mirror");
617 return CompressedOops::decode(_archived_mirror);
618 }
619
620 narrowOop Klass::archived_java_mirror_raw_narrow() {
621 assert(has_raw_archived_mirror(), "must have raw archived mirror");
622 return _archived_mirror;
623 }
624
625 // No GC barrier
626 void Klass::set_archived_java_mirror_raw(oop m) {
627 assert(DumpSharedSpaces, "called only during runtime");
628 _archived_mirror = CompressedOops::encode(m);
629 }
630 #endif // INCLUDE_CDS_JAVA_HEAP
631
632 Klass* Klass::array_klass_or_null(int rank) {
633 EXCEPTION_MARK;
634 // No exception can be thrown by array_klass_impl when called with or_null == true.
635 // (In anycase, the execption mark will fail if it do so)
636 return array_klass_impl(true, rank, THREAD);
637 }
638
639
640 Klass* Klass::array_klass_or_null() {
641 EXCEPTION_MARK;
642 // No exception can be thrown by array_klass_impl when called with or_null == true.
643 // (In anycase, the execption mark will fail if it do so)
644 return array_klass_impl(true, THREAD);
645 }
646
647
648 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
649 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
650 return NULL;
651 }
652
653
654 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
655 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
656 return NULL;
657 }
658
659 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) {
660 if (length > max_length) {
661 if (!THREAD->in_retryable_allocation()) {
662 report_java_out_of_memory("Requested array size exceeds VM limit");
663 JvmtiExport::post_array_size_exhausted();
664 THROW_OOP(Universe::out_of_memory_error_array_size());
665 } else {
666 THROW_OOP(Universe::out_of_memory_error_retry());
667 }
668 } else if (length < 0) {
669 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length));
670 }
671 }
672
673 // In product mode, this function doesn't have virtual function calls so
674 // there might be some performance advantage to handling InstanceKlass here.
675 const char* Klass::external_name() const {
676 if (is_instance_klass()) {
677 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
678 if (ik->is_unsafe_anonymous()) {
679 char addr_buf[20];
680 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
681 size_t addr_len = strlen(addr_buf);
682 size_t name_len = name()->utf8_length();
683 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
684 name()->as_klass_external_name(result, (int) name_len + 1);
685 assert(strlen(result) == name_len, "");
686 strcpy(result + name_len, addr_buf);
687 assert(strlen(result) == name_len + addr_len, "");
688 return result;
689 }
690 }
691 if (name() == NULL) return "<unknown>";
692 return name()->as_klass_external_name();
693 }
694
695 const char* Klass::signature_name() const {
696 if (name() == NULL) return "<unknown>";
697 return name()->as_C_string();
698 }
699
700 const char* Klass::external_kind() const {
701 if (is_interface()) return "interface";
702 if (is_abstract()) return "abstract class";
703 return "class";
704 }
705
706 // Unless overridden, modifier_flags is 0.
707 jint Klass::compute_modifier_flags(TRAPS) const {
708 return 0;
709 }
710
711 int Klass::atomic_incr_biased_lock_revocation_count() {
712 return (int) Atomic::add(&_biased_lock_revocation_count, 1);
713 }
714
715 // Unless overridden, jvmti_class_status has no flags set.
716 jint Klass::jvmti_class_status() const {
717 return 0;
718 }
719
720
721 // Printing
722
723 void Klass::print_on(outputStream* st) const {
724 ResourceMark rm;
725 // print title
726 st->print("%s", internal_name());
727 print_address_on(st);
728 st->cr();
729 }
730
731 #define BULLET " - "
732
733 void Klass::oop_print_on(oop obj, outputStream* st) {
734 // print title
735 st->print_cr("%s ", internal_name());
736 obj->print_address_on(st);
737
738 if (WizardMode) {
739 // print header
740 obj->mark().print_on(st);
741 st->cr();
742 st->print(BULLET"prototype_header: " INTPTR_FORMAT, _prototype_header.value());
743 st->cr();
744 }
745
746 // print class
747 st->print(BULLET"klass: ");
748 obj->klass()->print_value_on(st);
749 st->cr();
750 }
751
752 void Klass::oop_print_value_on(oop obj, outputStream* st) {
753 // print title
754 ResourceMark rm; // Cannot print in debug mode without this
755 st->print("%s", internal_name());
756 obj->print_address_on(st);
757 }
758
759 #if INCLUDE_SERVICES
760 // Size Statistics
761 void Klass::collect_statistics(KlassSizeStats *sz) const {
762 sz->_klass_bytes = sz->count(this);
763 sz->_mirror_bytes = sz->count(java_mirror_no_keepalive());
764 sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
765
766 sz->_ro_bytes += sz->_secondary_supers_bytes;
767 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
768 }
769 #endif // INCLUDE_SERVICES
770
771 // Verification
772
773 void Klass::verify_on(outputStream* st) {
774
775 // This can be expensive, but it is worth checking that this klass is actually
776 // in the CLD graph but not in production.
777 assert(Metaspace::contains((address)this), "Should be");
778
779 guarantee(this->is_klass(),"should be klass");
780
781 if (super() != NULL) {
782 guarantee(super()->is_klass(), "should be klass");
783 }
784 if (secondary_super_cache() != NULL) {
785 Klass* ko = secondary_super_cache();
786 guarantee(ko->is_klass(), "should be klass");
787 }
788 for ( uint i = 0; i < primary_super_limit(); i++ ) {
789 Klass* ko = _primary_supers[i];
790 if (ko != NULL) {
791 guarantee(ko->is_klass(), "should be klass");
792 }
793 }
794
795 if (java_mirror_no_keepalive() != NULL) {
796 guarantee(oopDesc::is_oop(java_mirror_no_keepalive()), "should be instance");
797 }
798 }
799
800 void Klass::oop_verify_on(oop obj, outputStream* st) {
801 guarantee(oopDesc::is_oop(obj), "should be oop");
802 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
803 }
804
805 bool Klass::is_valid(Klass* k) {
806 if (!is_aligned(k, sizeof(MetaWord))) return false;
807 if ((size_t)k < os::min_page_size()) return false;
808
809 if (!os::is_readable_range(k, k + 1)) return false;
810 if (!Metaspace::contains(k)) return false;
811
812 if (!Symbol::is_valid(k->name())) return false;
813 return ClassLoaderDataGraph::is_valid(k->class_loader_data());
814 }
815
816 Method* Klass::method_at_vtable(int index) {
817 #ifndef PRODUCT
818 assert(index >= 0, "valid vtable index");
819 if (DebugVtables) {
820 verify_vtable_index(index);
821 }
822 #endif
823 return start_of_vtable()[index].method();
824 }
825
826
827 #ifndef PRODUCT
828
829 bool Klass::verify_vtable_index(int i) {
830 int limit = vtable_length()/vtableEntry::size();
831 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
832 return true;
833 }
834
835 #endif // PRODUCT
836
837 // Caller needs ResourceMark
838 // joint_in_module_of_loader provides an optimization if 2 classes are in
839 // the same module to succinctly print out relevant information about their
840 // module name and class loader's name_and_id for error messages.
841 // Format:
842 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2>
843 // are in module <module-name>[@<version>]
844 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
845 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const {
846 assert(module() == class2->module(), "classes do not have the same module");
847 const char* class1_name = external_name();
848 size_t len = strlen(class1_name) + 1;
849
850 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader);
851 len += strlen(class2_description);
852
853 len += strlen(" and ");
854
855 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
856
857 // Just return the FQN if error when allocating string
858 if (joint_description == NULL) {
859 return class1_name;
860 }
861
862 jio_snprintf(joint_description, len, "%s and %s",
863 class1_name,
864 class2_description);
865
866 return joint_description;
867 }
868
869 // Caller needs ResourceMark
870 // class_in_module_of_loader provides a standard way to include
871 // relevant information about a class, such as its module name as
872 // well as its class loader's name_and_id, in error messages and logging.
873 // Format:
874 // <fully-qualified-external-class-name> is in module <module-name>[@<version>]
875 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
876 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const {
877 // 1. fully qualified external name of class
878 const char* klass_name = external_name();
879 size_t len = strlen(klass_name) + 1;
880
881 // 2. module name + @version
882 const char* module_name = "";
883 const char* version = "";
884 bool has_version = false;
885 bool module_is_named = false;
886 const char* module_name_phrase = "";
887 const Klass* bottom_klass = is_objArray_klass() ?
888 ObjArrayKlass::cast(this)->bottom_klass() : this;
889 if (bottom_klass->is_instance_klass()) {
890 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module();
891 if (module->is_named()) {
892 module_is_named = true;
893 module_name_phrase = "module ";
894 module_name = module->name()->as_C_string();
895 len += strlen(module_name);
896 // Use version if exists and is not a jdk module
897 if (module->should_show_version()) {
898 has_version = true;
899 version = module->version()->as_C_string();
900 // Include stlen(version) + 1 for the "@"
901 len += strlen(version) + 1;
902 }
903 } else {
904 module_name = UNNAMED_MODULE;
905 len += UNNAMED_MODULE_LEN;
906 }
907 } else {
908 // klass is an array of primitives, module is java.base
909 module_is_named = true;
910 module_name_phrase = "module ";
911 module_name = JAVA_BASE_NAME;
912 len += JAVA_BASE_NAME_LEN;
913 }
914
915 // 3. class loader's name_and_id
916 ClassLoaderData* cld = class_loader_data();
917 assert(cld != NULL, "class_loader_data should not be null");
918 const char* loader_name_and_id = cld->loader_name_and_id();
919 len += strlen(loader_name_and_id);
920
921 // 4. include parent loader information
922 const char* parent_loader_phrase = "";
923 const char* parent_loader_name_and_id = "";
924 if (include_parent_loader &&
925 !cld->is_builtin_class_loader_data()) {
926 oop parent_loader = java_lang_ClassLoader::parent(class_loader());
927 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data_or_null(parent_loader);
928 // The parent loader's ClassLoaderData could be null if it is
929 // a delegating class loader that has never defined a class.
930 // In this case the loader's name must be obtained via the parent loader's oop.
931 if (parent_cld == NULL) {
932 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader);
933 if (cl_name_and_id != NULL) {
934 parent_loader_name_and_id = java_lang_String::as_utf8_string(cl_name_and_id);
935 }
936 } else {
937 parent_loader_name_and_id = parent_cld->loader_name_and_id();
938 }
939 parent_loader_phrase = ", parent loader ";
940 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id);
941 }
942
943 // Start to construct final full class description string
944 len += ((use_are) ? strlen(" are in ") : strlen(" is in "));
945 len += strlen(module_name_phrase) + strlen(" of loader ");
946
947 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
948
949 // Just return the FQN if error when allocating string
950 if (class_description == NULL) {
951 return klass_name;
952 }
953
954 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s",
955 klass_name,
956 (use_are) ? "are" : "is",
957 module_name_phrase,
958 module_name,
959 (has_version) ? "@" : "",
960 (has_version) ? version : "",
961 loader_name_and_id,
962 parent_loader_phrase,
963 parent_loader_name_and_id);
964
965 return class_description;
966 }