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 == NULL || s->next_sibling() != NULL) // 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 // superklass links
362 InstanceKlass* Klass::superklass() const {
363 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
364 return _super == NULL ? NULL : InstanceKlass::cast(_super);
365 }
366
367 // subklass links. Used by the compiler (and vtable initialization)
368 // May be cleaned concurrently, so must use the Compile_lock.
369 // The log parameter is for clean_weak_klass_links to report unlinked classes.
370 Klass* Klass::subklass(bool log) const {
371 assert_locked_or_safepoint(Compile_lock);
372 for (Klass* chain = _subklass; chain != NULL;
373 chain = chain->_next_sibling) {
374 if (chain->is_loader_alive()) {
375 return chain;
376 } else if (log) {
377 if (log_is_enabled(Trace, class, unload)) {
378 ResourceMark rm;
379 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name());
380 }
381 }
382 }
383 return NULL;
384 }
385
386 Klass* Klass::next_sibling(bool log) const {
387 assert_locked_or_safepoint(Compile_lock);
388 for (Klass* chain = _next_sibling; chain != NULL;
389 chain = chain->_next_sibling) {
390 // Only return alive klass, there may be stale klass
391 // in this chain if cleaned concurrently.
392 if (chain->is_loader_alive()) {
393 return chain;
394 } else if (log) {
395 if (log_is_enabled(Trace, class, unload)) {
396 ResourceMark rm;
397 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name());
398 }
399 }
400 }
401 return NULL;
402 }
403
404 void Klass::set_subklass(Klass* s) {
405 assert(s != this, "sanity check");
406 _subklass = s;
407 }
408
409 void Klass::set_next_sibling(Klass* s) {
410 assert(s != this, "sanity check");
411 _next_sibling = s;
412 }
413
414 void Klass::append_to_sibling_list() {
415 assert_locked_or_safepoint(Compile_lock);
416 debug_only(verify();)
417 // add ourselves to superklass' subklass list
418 InstanceKlass* super = superklass();
419 if (super == NULL) return; // special case: class Object
420 assert((!super->is_interface() // interfaces cannot be supers
421 && (super->superklass() == NULL || !is_interface())),
422 "an interface can only be a subklass of Object");
423
424 Klass* prev_first_subklass = super->subklass();
425 if (prev_first_subklass != NULL) {
426 // set our sibling to be the superklass' previous first subklass
427 set_next_sibling(prev_first_subklass);
428 }
429 // make ourselves the superklass' first subklass
430 super->set_subklass(this);
431 debug_only(verify();)
432 }
433
434 oop Klass::holder_phantom() const {
435 return class_loader_data()->holder_phantom();
436 }
437
438 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
439 assert_locked_or_safepoint(Compile_lock);
440 if (!ClassUnloading || !unloading_occurred) {
441 return;
442 }
443
444 Klass* root = SystemDictionary::Object_klass();
445 Stack<Klass*, mtGC> stack;
446
447 stack.push(root);
448 while (!stack.is_empty()) {
449 Klass* current = stack.pop();
450
451 assert(current->is_loader_alive(), "just checking, this should be live");
452
453 // Find and set the first alive subklass
454 Klass* sub = current->subklass(true);
455 current->set_subklass(sub);
456 if (sub != NULL) {
457 stack.push(sub);
458 }
459
460 // Find and set the first alive sibling
461 Klass* sibling = current->next_sibling(true);
462 current->set_next_sibling(sibling);
463 if (sibling != NULL) {
464 stack.push(sibling);
465 }
466
467 // Clean the implementors list and method data.
468 if (clean_alive_klasses && current->is_instance_klass()) {
469 InstanceKlass* ik = InstanceKlass::cast(current);
470 ik->clean_weak_instanceklass_links();
471
472 // JVMTI RedefineClasses creates previous versions that are not in
473 // the class hierarchy, so process them here.
474 while ((ik = ik->previous_versions()) != NULL) {
475 ik->clean_weak_instanceklass_links();
476 }
477 }
478 }
479 }
480
481 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
482 if (log_is_enabled(Trace, cds)) {
483 ResourceMark rm;
484 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
485 }
486
487 it->push(&_name);
488 it->push(&_secondary_super_cache);
489 it->push(&_secondary_supers);
490 for (int i = 0; i < _primary_super_limit; i++) {
491 it->push(&_primary_supers[i]);
492 }
493 it->push(&_super);
494 it->push(&_subklass);
495 it->push(&_next_sibling);
496 it->push(&_next_link);
497
498 vtableEntry* vt = start_of_vtable();
499 for (int i=0; i<vtable_length(); i++) {
500 it->push(vt[i].method_addr());
501 }
502 }
503
504 void Klass::remove_unshareable_info() {
505 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
506 JFR_ONLY(REMOVE_ID(this);)
507 if (log_is_enabled(Trace, cds, unshareable)) {
508 ResourceMark rm;
509 log_trace(cds, unshareable)("remove: %s", external_name());
510 }
511
512 set_subklass(NULL);
513 set_next_sibling(NULL);
514 set_next_link(NULL);
515
516 // Null out class_loader_data because we don't share that yet.
517 set_class_loader_data(NULL);
518 set_is_shared();
519 }
520
521 void Klass::remove_java_mirror() {
522 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
523 if (log_is_enabled(Trace, cds, unshareable)) {
524 ResourceMark rm;
525 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
526 }
527 // Just null out the mirror. The class_loader_data() no longer exists.
528 _java_mirror = NULL;
529 }
530
531 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
532 assert(is_klass(), "ensure C++ vtable is restored");
533 assert(is_shared(), "must be set");
534 JFR_ONLY(RESTORE_ID(this);)
535 if (log_is_enabled(Trace, cds, unshareable)) {
536 ResourceMark rm;
537 log_trace(cds, unshareable)("restore: %s", external_name());
538 }
539
540 // If an exception happened during CDS restore, some of these fields may already be
541 // set. We leave the class on the CLD list, even if incomplete so that we don't
542 // modify the CLD list outside a safepoint.
543 if (class_loader_data() == NULL) {
544 // Restore class_loader_data to the null class loader data
545 set_class_loader_data(loader_data);
546
547 // Add to null class loader list first before creating the mirror
548 // (same order as class file parsing)
549 loader_data->add_class(this);
550 }
551
552 Handle loader(THREAD, loader_data->class_loader());
553 ModuleEntry* module_entry = NULL;
554 Klass* k = this;
555 if (k->is_objArray_klass()) {
556 k = ObjArrayKlass::cast(k)->bottom_klass();
557 }
558 // Obtain klass' module.
559 if (k->is_instance_klass()) {
560 InstanceKlass* ik = (InstanceKlass*) k;
561 module_entry = ik->module();
562 } else {
563 module_entry = ModuleEntryTable::javabase_moduleEntry();
564 }
565 // Obtain java.lang.Module, if available
566 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
567
568 if (this->has_raw_archived_mirror()) {
569 ResourceMark rm;
570 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
571 if (HeapShared::open_archive_heap_region_mapped()) {
572 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle,
573 protection_domain,
574 CHECK);
575 if (present) {
576 return;
577 }
578 }
579
580 // No archived mirror data
581 log_debug(cds, mirror)("No archived mirror data for %s", external_name());
582 _java_mirror = NULL;
583 this->clear_has_raw_archived_mirror();
584 }
585
586 // Only recreate it if not present. A previous attempt to restore may have
587 // gotten an OOM later but keep the mirror if it was created.
588 if (java_mirror() == NULL) {
589 log_trace(cds, mirror)("Recreate mirror for %s", external_name());
590 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
591 }
592 }
593
594 #if INCLUDE_CDS_JAVA_HEAP
595 // Used at CDS dump time to access the archived mirror. No GC barrier.
596 oop Klass::archived_java_mirror_raw() {
597 assert(has_raw_archived_mirror(), "must have raw archived mirror");
598 return CompressedOops::decode(_archived_mirror);
599 }
600
601 narrowOop Klass::archived_java_mirror_raw_narrow() {
602 assert(has_raw_archived_mirror(), "must have raw archived mirror");
603 return _archived_mirror;
604 }
605
606 // No GC barrier
607 void Klass::set_archived_java_mirror_raw(oop m) {
608 assert(DumpSharedSpaces, "called only during runtime");
609 _archived_mirror = CompressedOops::encode(m);
610 }
611 #endif // INCLUDE_CDS_JAVA_HEAP
612
613 Klass* Klass::array_klass_or_null(int rank) {
614 EXCEPTION_MARK;
615 // No exception can be thrown by array_klass_impl when called with or_null == true.
616 // (In anycase, the execption mark will fail if it do so)
617 return array_klass_impl(true, rank, THREAD);
618 }
619
620
621 Klass* Klass::array_klass_or_null() {
622 EXCEPTION_MARK;
623 // No exception can be thrown by array_klass_impl when called with or_null == true.
624 // (In anycase, the execption mark will fail if it do so)
625 return array_klass_impl(true, THREAD);
626 }
627
628
629 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
630 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
631 return NULL;
632 }
633
634
635 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
636 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
637 return NULL;
638 }
639
640 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) {
641 if (length > max_length) {
642 if (!THREAD->in_retryable_allocation()) {
643 report_java_out_of_memory("Requested array size exceeds VM limit");
644 JvmtiExport::post_array_size_exhausted();
645 THROW_OOP(Universe::out_of_memory_error_array_size());
646 } else {
647 THROW_OOP(Universe::out_of_memory_error_retry());
648 }
649 } else if (length < 0) {
650 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length));
651 }
652 }
653
654 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
655
656 // In product mode, this function doesn't have virtual function calls so
657 // there might be some performance advantage to handling InstanceKlass here.
658 const char* Klass::external_name() const {
659 if (is_instance_klass()) {
660 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
661 if (ik->is_unsafe_anonymous()) {
662 char addr_buf[20];
663 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
664 size_t addr_len = strlen(addr_buf);
665 size_t name_len = name()->utf8_length();
666 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
667 name()->as_klass_external_name(result, (int) name_len + 1);
668 assert(strlen(result) == name_len, "");
669 strcpy(result + name_len, addr_buf);
670 assert(strlen(result) == name_len + addr_len, "");
671 return result;
672 }
673 }
674 if (name() == NULL) return "<unknown>";
675 return name()->as_klass_external_name();
676 }
677
678 const char* Klass::signature_name() const {
679 if (name() == NULL) return "<unknown>";
680 return name()->as_C_string();
681 }
682
683 const char* Klass::external_kind() const {
684 if (is_interface()) return "interface";
685 if (is_abstract()) return "abstract class";
686 return "class";
687 }
688
689 // Unless overridden, modifier_flags is 0.
690 jint Klass::compute_modifier_flags(TRAPS) const {
691 return 0;
692 }
693
694 int Klass::atomic_incr_biased_lock_revocation_count() {
695 return (int) Atomic::add(1, &_biased_lock_revocation_count);
696 }
697
698 // Unless overridden, jvmti_class_status has no flags set.
699 jint Klass::jvmti_class_status() const {
700 return 0;
701 }
702
703
704 // Printing
705
706 void Klass::print_on(outputStream* st) const {
707 ResourceMark rm;
708 // print title
709 st->print("%s", internal_name());
710 print_address_on(st);
711 st->cr();
712 }
713
714 void Klass::oop_print_on(oop obj, outputStream* st) {
715 ResourceMark rm;
716 // print title
717 st->print_cr("%s ", internal_name());
718 obj->print_address_on(st);
719
720 if (WizardMode) {
721 // print header
722 obj->mark()->print_on(st);
723 }
724
725 // print class
726 st->print(" - klass: ");
727 obj->klass()->print_value_on(st);
728 st->cr();
729 }
730
731 void Klass::oop_print_value_on(oop obj, outputStream* st) {
732 // print title
733 ResourceMark rm; // Cannot print in debug mode without this
734 st->print("%s", internal_name());
735 obj->print_address_on(st);
736 }
737
738 #if INCLUDE_SERVICES
739 // Size Statistics
740 void Klass::collect_statistics(KlassSizeStats *sz) const {
741 sz->_klass_bytes = sz->count(this);
742 sz->_mirror_bytes = sz->count(java_mirror());
743 sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
744
745 sz->_ro_bytes += sz->_secondary_supers_bytes;
746 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
747 }
748 #endif // INCLUDE_SERVICES
749
750 // Verification
751
752 void Klass::verify_on(outputStream* st) {
753
754 // This can be expensive, but it is worth checking that this klass is actually
755 // in the CLD graph but not in production.
756 assert(Metaspace::contains((address)this), "Should be");
757
758 guarantee(this->is_klass(),"should be klass");
759
760 if (super() != NULL) {
761 guarantee(super()->is_klass(), "should be klass");
762 }
763 if (secondary_super_cache() != NULL) {
764 Klass* ko = secondary_super_cache();
765 guarantee(ko->is_klass(), "should be klass");
766 }
767 for ( uint i = 0; i < primary_super_limit(); i++ ) {
768 Klass* ko = _primary_supers[i];
769 if (ko != NULL) {
770 guarantee(ko->is_klass(), "should be klass");
771 }
772 }
773
774 if (java_mirror() != NULL) {
775 guarantee(oopDesc::is_oop(java_mirror()), "should be instance");
776 }
777 }
778
779 void Klass::oop_verify_on(oop obj, outputStream* st) {
780 guarantee(oopDesc::is_oop(obj), "should be oop");
781 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
782 }
783
784 Klass* Klass::decode_klass_raw(narrowKlass narrow_klass) {
785 return (Klass*)(void*)( (uintptr_t)Universe::narrow_klass_base() +
786 ((uintptr_t)narrow_klass << Universe::narrow_klass_shift()));
787 }
788
789 bool Klass::is_valid(Klass* k) {
790 if (!is_aligned(k, sizeof(MetaWord))) return false;
791 if ((size_t)k < os::min_page_size()) return false;
792
793 if (!os::is_readable_range(k, k + 1)) return false;
794 if (!MetaspaceUtils::is_range_in_committed(k, k + 1)) return false;
795
796 if (!Symbol::is_valid(k->name())) return false;
797 return ClassLoaderDataGraph::is_valid(k->class_loader_data());
798 }
799
800 klassVtable Klass::vtable() const {
801 return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size());
802 }
803
804 vtableEntry* Klass::start_of_vtable() const {
805 return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset()));
806 }
807
808 Method* Klass::method_at_vtable(int index) {
809 #ifndef PRODUCT
810 assert(index >= 0, "valid vtable index");
811 if (DebugVtables) {
812 verify_vtable_index(index);
813 }
814 #endif
815 return start_of_vtable()[index].method();
816 }
817
818 ByteSize Klass::vtable_start_offset() {
819 return in_ByteSize(InstanceKlass::header_size() * wordSize);
820 }
821
822 #ifndef PRODUCT
823
824 bool Klass::verify_vtable_index(int i) {
825 int limit = vtable_length()/vtableEntry::size();
826 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
827 return true;
828 }
829
830 #endif // PRODUCT
831
832 // Caller needs ResourceMark
833 // joint_in_module_of_loader provides an optimization if 2 classes are in
834 // the same module to succinctly print out relevant information about their
835 // module name and class loader's name_and_id for error messages.
836 // Format:
837 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2>
838 // are in module <module-name>[@<version>]
839 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
840 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const {
841 assert(module() == class2->module(), "classes do not have the same module");
842 const char* class1_name = external_name();
843 size_t len = strlen(class1_name) + 1;
844
845 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader);
846 len += strlen(class2_description);
847
848 len += strlen(" and ");
849
850 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
851
852 // Just return the FQN if error when allocating string
853 if (joint_description == NULL) {
854 return class1_name;
855 }
856
857 jio_snprintf(joint_description, len, "%s and %s",
858 class1_name,
859 class2_description);
860
861 return joint_description;
862 }
863
864 // Caller needs ResourceMark
865 // class_in_module_of_loader provides a standard way to include
866 // relevant information about a class, such as its module name as
867 // well as its class loader's name_and_id, in error messages and logging.
868 // Format:
869 // <fully-qualified-external-class-name> is in module <module-name>[@<version>]
870 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
871 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const {
872 // 1. fully qualified external name of class
873 const char* klass_name = external_name();
874 size_t len = strlen(klass_name) + 1;
875
876 // 2. module name + @version
877 const char* module_name = "";
878 const char* version = "";
879 bool has_version = false;
880 bool module_is_named = false;
881 const char* module_name_phrase = "";
882 const Klass* bottom_klass = is_objArray_klass() ?
883 ObjArrayKlass::cast(this)->bottom_klass() : this;
884 if (bottom_klass->is_instance_klass()) {
885 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module();
886 if (module->is_named()) {
887 module_is_named = true;
888 module_name_phrase = "module ";
889 module_name = module->name()->as_C_string();
890 len += strlen(module_name);
891 // Use version if exists and is not a jdk module
892 if (module->should_show_version()) {
893 has_version = true;
894 version = module->version()->as_C_string();
895 // Include stlen(version) + 1 for the "@"
896 len += strlen(version) + 1;
897 }
898 } else {
899 module_name = UNNAMED_MODULE;
900 len += UNNAMED_MODULE_LEN;
901 }
902 } else {
903 // klass is an array of primitives, module is java.base
904 module_is_named = true;
905 module_name_phrase = "module ";
906 module_name = JAVA_BASE_NAME;
907 len += JAVA_BASE_NAME_LEN;
908 }
909
910 // 3. class loader's name_and_id
911 ClassLoaderData* cld = class_loader_data();
912 assert(cld != NULL, "class_loader_data should not be null");
913 const char* loader_name_and_id = cld->loader_name_and_id();
914 len += strlen(loader_name_and_id);
915
916 // 4. include parent loader information
917 const char* parent_loader_phrase = "";
918 const char* parent_loader_name_and_id = "";
919 if (include_parent_loader &&
920 !cld->is_builtin_class_loader_data()) {
921 oop parent_loader = java_lang_ClassLoader::parent(class_loader());
922 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data(parent_loader);
923 assert(parent_cld != NULL, "parent's class loader data should not be null");
924 parent_loader_name_and_id = parent_cld->loader_name_and_id();
925 parent_loader_phrase = ", parent loader ";
926 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id);
927 }
928
929 // Start to construct final full class description string
930 len += ((use_are) ? strlen(" are in ") : strlen(" is in "));
931 len += strlen(module_name_phrase) + strlen(" of loader ");
932
933 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
934
935 // Just return the FQN if error when allocating string
936 if (class_description == NULL) {
937 return klass_name;
938 }
939
940 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s",
941 klass_name,
942 (use_are) ? "are" : "is",
943 module_name_phrase,
944 module_name,
945 (has_version) ? "@" : "",
946 (has_version) ? version : "",
947 loader_name_and_id,
948 parent_loader_phrase,
949 parent_loader_name_and_id);
950
951 return class_description;
952 }