Fri, 16 Nov 2012 09:19:12 -0500
Merge
1 /*
2 * Copyright (c) 1997, 2012, 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 */
25 #include "precompiled.hpp"
26 #include "classfile/javaClasses.hpp"
27 #include "classfile/dictionary.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "gc_implementation/shared/markSweep.inline.hpp"
31 #include "gc_interface/collectedHeap.inline.hpp"
32 #include "memory/metadataFactory.hpp"
33 #include "memory/oopFactory.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "oops/instanceKlass.hpp"
36 #include "oops/klass.inline.hpp"
37 #include "oops/oop.inline2.hpp"
38 #include "runtime/atomic.hpp"
39 #include "utilities/stack.hpp"
40 #ifndef SERIALGC
41 #include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
42 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
43 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
44 #endif
46 void Klass::set_name(Symbol* n) {
47 _name = n;
48 if (_name != NULL) _name->increment_refcount();
49 }
51 bool Klass::is_subclass_of(Klass* k) const {
52 // Run up the super chain and check
53 if (this == k) return true;
55 Klass* t = const_cast<Klass*>(this)->super();
57 while (t != NULL) {
58 if (t == k) return true;
59 t = t->super();
60 }
61 return false;
62 }
64 bool Klass::search_secondary_supers(Klass* k) const {
65 // Put some extra logic here out-of-line, before the search proper.
66 // This cuts down the size of the inline method.
68 // This is necessary, since I am never in my own secondary_super list.
69 if (this == k)
70 return true;
71 // Scan the array-of-objects for a match
72 int cnt = secondary_supers()->length();
73 for (int i = 0; i < cnt; i++) {
74 if (secondary_supers()->at(i) == k) {
75 ((Klass*)this)->set_secondary_super_cache(k);
76 return true;
77 }
78 }
79 return false;
80 }
82 // Return self, except for abstract classes with exactly 1
83 // implementor. Then return the 1 concrete implementation.
84 Klass *Klass::up_cast_abstract() {
85 Klass *r = this;
86 while( r->is_abstract() ) { // Receiver is abstract?
87 Klass *s = r->subklass(); // Check for exactly 1 subklass
88 if( !s || s->next_sibling() ) // Oops; wrong count; give up
89 return this; // Return 'this' as a no-progress flag
90 r = s; // Loop till find concrete class
91 }
92 return r; // Return the 1 concrete class
93 }
95 // Find LCA in class hierarchy
96 Klass *Klass::LCA( Klass *k2 ) {
97 Klass *k1 = this;
98 while( 1 ) {
99 if( k1->is_subtype_of(k2) ) return k2;
100 if( k2->is_subtype_of(k1) ) return k1;
101 k1 = k1->super();
102 k2 = k2->super();
103 }
104 }
107 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
108 ResourceMark rm(THREAD);
109 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
110 : vmSymbols::java_lang_InstantiationException(), external_name());
111 }
114 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
115 THROW(vmSymbols::java_lang_ArrayStoreException());
116 }
119 void Klass::initialize(TRAPS) {
120 ShouldNotReachHere();
121 }
123 bool Klass::compute_is_subtype_of(Klass* k) {
124 assert(k->is_klass(), "argument must be a class");
125 return is_subclass_of(k);
126 }
129 Method* Klass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
130 #ifdef ASSERT
131 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
132 " Likely error: reflection method does not correctly"
133 " wrap return value in a mirror object.");
134 #endif
135 ShouldNotReachHere();
136 return NULL;
137 }
139 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) {
140 return Metaspace::allocate(loader_data, word_size, /*read_only*/false,
141 Metaspace::ClassType, CHECK_NULL);
142 }
144 Klass::Klass() {
145 Klass* k = this;
147 { // Preinitialize supertype information.
148 // A later call to initialize_supers() may update these settings:
149 set_super(NULL);
150 for (juint i = 0; i < Klass::primary_super_limit(); i++) {
151 _primary_supers[i] = NULL;
152 }
153 set_secondary_supers(NULL);
154 _primary_supers[0] = k;
155 set_super_check_offset(in_bytes(primary_supers_offset()));
156 }
158 set_java_mirror(NULL);
159 set_modifier_flags(0);
160 set_layout_helper(Klass::_lh_neutral_value);
161 set_name(NULL);
162 AccessFlags af;
163 af.set_flags(0);
164 set_access_flags(af);
165 set_subklass(NULL);
166 set_next_sibling(NULL);
167 set_next_link(NULL);
168 set_alloc_count(0);
169 TRACE_SET_KLASS_TRACE_ID(this, 0);
171 set_prototype_header(markOopDesc::prototype());
172 set_biased_lock_revocation_count(0);
173 set_last_biased_lock_bulk_revocation_time(0);
175 // The klass doesn't have any references at this point.
176 clear_modified_oops();
177 clear_accumulated_modified_oops();
178 }
180 jint Klass::array_layout_helper(BasicType etype) {
181 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
182 // Note that T_ARRAY is not allowed here.
183 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
184 int esize = type2aelembytes(etype);
185 bool isobj = (etype == T_OBJECT);
186 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
187 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
189 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
190 assert(layout_helper_is_array(lh), "correct kind");
191 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
192 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
193 assert(layout_helper_header_size(lh) == hsize, "correct decode");
194 assert(layout_helper_element_type(lh) == etype, "correct decode");
195 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
197 return lh;
198 }
200 bool Klass::can_be_primary_super_slow() const {
201 if (super() == NULL)
202 return true;
203 else if (super()->super_depth() >= primary_super_limit()-1)
204 return false;
205 else
206 return true;
207 }
209 void Klass::initialize_supers(Klass* k, TRAPS) {
210 if (FastSuperclassLimit == 0) {
211 // None of the other machinery matters.
212 set_super(k);
213 return;
214 }
215 if (k == NULL) {
216 set_super(NULL);
217 _primary_supers[0] = this;
218 assert(super_depth() == 0, "Object must already be initialized properly");
219 } else if (k != super() || k == SystemDictionary::Object_klass()) {
220 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
221 "initialize this only once to a non-trivial value");
222 set_super(k);
223 Klass* sup = k;
224 int sup_depth = sup->super_depth();
225 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
226 if (!can_be_primary_super_slow())
227 my_depth = primary_super_limit();
228 for (juint i = 0; i < my_depth; i++) {
229 _primary_supers[i] = sup->_primary_supers[i];
230 }
231 Klass* *super_check_cell;
232 if (my_depth < primary_super_limit()) {
233 _primary_supers[my_depth] = this;
234 super_check_cell = &_primary_supers[my_depth];
235 } else {
236 // Overflow of the primary_supers array forces me to be secondary.
237 super_check_cell = &_secondary_super_cache;
238 }
239 set_super_check_offset((address)super_check_cell - (address) this);
241 #ifdef ASSERT
242 {
243 juint j = super_depth();
244 assert(j == my_depth, "computed accessor gets right answer");
245 Klass* t = this;
246 while (!t->can_be_primary_super()) {
247 t = t->super();
248 j = t->super_depth();
249 }
250 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
251 assert(primary_super_of_depth(j1) == NULL, "super list padding");
252 }
253 while (t != NULL) {
254 assert(primary_super_of_depth(j) == t, "super list initialization");
255 t = t->super();
256 --j;
257 }
258 assert(j == (juint)-1, "correct depth count");
259 }
260 #endif
261 }
263 if (secondary_supers() == NULL) {
264 KlassHandle this_kh (THREAD, this);
266 // Now compute the list of secondary supertypes.
267 // Secondaries can occasionally be on the super chain,
268 // if the inline "_primary_supers" array overflows.
269 int extras = 0;
270 Klass* p;
271 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
272 ++extras;
273 }
275 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
277 // Compute the "real" non-extra secondaries.
278 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras);
279 if (secondaries == NULL) {
280 // secondary_supers set by compute_secondary_supers
281 return;
282 }
284 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
286 for (p = this_kh->super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
287 int i; // Scan for overflow primaries being duplicates of 2nd'arys
289 // This happens frequently for very deeply nested arrays: the
290 // primary superclass chain overflows into the secondary. The
291 // secondary list contains the element_klass's secondaries with
292 // an extra array dimension added. If the element_klass's
293 // secondary list already contains some primary overflows, they
294 // (with the extra level of array-ness) will collide with the
295 // normal primary superclass overflows.
296 for( i = 0; i < secondaries->length(); i++ ) {
297 if( secondaries->at(i) == p )
298 break;
299 }
300 if( i < secondaries->length() )
301 continue; // It's a dup, don't put it in
302 primaries->push(p);
303 }
304 // Combine the two arrays into a metadata object to pack the array.
305 // The primaries are added in the reverse order, then the secondaries.
306 int new_length = primaries->length() + secondaries->length();
307 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
308 class_loader_data(), new_length, CHECK);
309 int fill_p = primaries->length();
310 for (int j = 0; j < fill_p; j++) {
311 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
312 }
313 for( int j = 0; j < secondaries->length(); j++ ) {
314 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
315 }
317 #ifdef ASSERT
318 // We must not copy any NULL placeholders left over from bootstrap.
319 for (int j = 0; j < s2->length(); j++) {
320 assert(s2->at(j) != NULL, "correct bootstrapping order");
321 }
322 #endif
324 this_kh->set_secondary_supers(s2);
325 }
326 }
328 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots) {
329 assert(num_extra_slots == 0, "override for complex klasses");
330 set_secondary_supers(Universe::the_empty_klass_array());
331 return NULL;
332 }
335 Klass* Klass::subklass() const {
336 return _subklass == NULL ? NULL : _subklass;
337 }
339 InstanceKlass* Klass::superklass() const {
340 assert(super() == NULL || super()->oop_is_instance(), "must be instance klass");
341 return _super == NULL ? NULL : InstanceKlass::cast(_super);
342 }
344 Klass* Klass::next_sibling() const {
345 return _next_sibling == NULL ? NULL : _next_sibling;
346 }
348 void Klass::set_subklass(Klass* s) {
349 assert(s != this, "sanity check");
350 _subklass = s;
351 }
353 void Klass::set_next_sibling(Klass* s) {
354 assert(s != this, "sanity check");
355 _next_sibling = s;
356 }
358 void Klass::append_to_sibling_list() {
359 debug_only(verify();)
360 // add ourselves to superklass' subklass list
361 InstanceKlass* super = superklass();
362 if (super == NULL) return; // special case: class Object
363 assert((!super->is_interface() // interfaces cannot be supers
364 && (super->superklass() == NULL || !is_interface())),
365 "an interface can only be a subklass of Object");
366 Klass* prev_first_subklass = super->subklass_oop();
367 if (prev_first_subklass != NULL) {
368 // set our sibling to be the superklass' previous first subklass
369 set_next_sibling(prev_first_subklass);
370 }
371 // make ourselves the superklass' first subklass
372 super->set_subklass(this);
373 debug_only(verify();)
374 }
376 void Klass::remove_from_sibling_list() {
377 // remove receiver from sibling list
378 InstanceKlass* super = superklass();
379 assert(super != NULL || this == SystemDictionary::Object_klass(), "should have super");
380 if (super == NULL) return; // special case: class Object
381 if (super->subklass() == this) {
382 // first subklass
383 super->set_subklass(_next_sibling);
384 } else {
385 Klass* sib = super->subklass();
386 while (sib->next_sibling() != this) {
387 sib = sib->next_sibling();
388 };
389 sib->set_next_sibling(_next_sibling);
390 }
391 }
393 bool Klass::is_loader_alive(BoolObjectClosure* is_alive) {
394 assert(is_metadata(), "p is not meta-data");
395 assert(ClassLoaderDataGraph::contains((address)this), "is in the metaspace");
396 // The class is alive iff the class loader is alive.
397 oop loader = class_loader();
398 return (loader == NULL) || is_alive->do_object_b(loader);
399 }
401 void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive) {
402 if (!ClassUnloading) {
403 return;
404 }
406 Klass* root = SystemDictionary::Object_klass();
407 Stack<Klass*, mtGC> stack;
409 stack.push(root);
410 while (!stack.is_empty()) {
411 Klass* current = stack.pop();
413 assert(current->is_loader_alive(is_alive), "just checking, this should be live");
415 // Find and set the first alive subklass
416 Klass* sub = current->subklass_oop();
417 while (sub != NULL && !sub->is_loader_alive(is_alive)) {
418 #ifndef PRODUCT
419 if (TraceClassUnloading && WizardMode) {
420 ResourceMark rm;
421 tty->print_cr("[Unlinking class (subclass) %s]", sub->external_name());
422 }
423 #endif
424 sub = sub->next_sibling_oop();
425 }
426 current->set_subklass(sub);
427 if (sub != NULL) {
428 stack.push(sub);
429 }
431 // Find and set the first alive sibling
432 Klass* sibling = current->next_sibling_oop();
433 while (sibling != NULL && !sibling->is_loader_alive(is_alive)) {
434 if (TraceClassUnloading && WizardMode) {
435 ResourceMark rm;
436 tty->print_cr("[Unlinking class (sibling) %s]", sibling->external_name());
437 }
438 sibling = sibling->next_sibling_oop();
439 }
440 current->set_next_sibling(sibling);
441 if (sibling != NULL) {
442 stack.push(sibling);
443 }
445 // Clean the implementors list and method data.
446 if (current->oop_is_instance()) {
447 InstanceKlass* ik = InstanceKlass::cast(current);
448 ik->clean_implementors_list(is_alive);
449 ik->clean_method_data(is_alive);
450 }
451 }
452 }
454 void Klass::klass_update_barrier_set(oop v) {
455 record_modified_oops();
456 }
458 void Klass::klass_update_barrier_set_pre(void* p, oop v) {
459 // This barrier used by G1, where it's used remember the old oop values,
460 // so that we don't forget any objects that were live at the snapshot at
461 // the beginning. This function is only used when we write oops into
462 // Klasses. Since the Klasses are used as roots in G1, we don't have to
463 // do anything here.
464 }
466 void Klass::klass_oop_store(oop* p, oop v) {
467 assert(!Universe::heap()->is_in_reserved((void*)p), "Should store pointer into metadata");
468 assert(v == NULL || Universe::heap()->is_in_reserved((void*)v), "Should store pointer to an object");
470 // do the store
471 if (always_do_update_barrier) {
472 klass_oop_store((volatile oop*)p, v);
473 } else {
474 klass_update_barrier_set_pre((void*)p, v);
475 *p = v;
476 klass_update_barrier_set(v);
477 }
478 }
480 void Klass::klass_oop_store(volatile oop* p, oop v) {
481 assert(!Universe::heap()->is_in_reserved((void*)p), "Should store pointer into metadata");
482 assert(v == NULL || Universe::heap()->is_in_reserved((void*)v), "Should store pointer to an object");
484 klass_update_barrier_set_pre((void*)p, v);
485 OrderAccess::release_store_ptr(p, v);
486 klass_update_barrier_set(v);
487 }
489 void Klass::oops_do(OopClosure* cl) {
490 cl->do_oop(&_java_mirror);
491 }
493 void Klass::remove_unshareable_info() {
494 set_subklass(NULL);
495 set_next_sibling(NULL);
496 // Clear the java mirror
497 set_java_mirror(NULL);
498 set_next_link(NULL);
500 // Null out class_loader_data because we don't share that yet.
501 set_class_loader_data(NULL);
502 }
504 void Klass::restore_unshareable_info(TRAPS) {
505 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
506 // Restore class_loader_data to the null class loader data
507 set_class_loader_data(loader_data);
509 // Add to null class loader list first before creating the mirror
510 // (same order as class file parsing)
511 loader_data->add_class(this);
513 // Recreate the class mirror
514 java_lang_Class::create_mirror(this, CHECK);
515 }
517 Klass* Klass::array_klass_or_null(int rank) {
518 EXCEPTION_MARK;
519 // No exception can be thrown by array_klass_impl when called with or_null == true.
520 // (In anycase, the execption mark will fail if it do so)
521 return array_klass_impl(true, rank, THREAD);
522 }
525 Klass* Klass::array_klass_or_null() {
526 EXCEPTION_MARK;
527 // No exception can be thrown by array_klass_impl when called with or_null == true.
528 // (In anycase, the execption mark will fail if it do so)
529 return array_klass_impl(true, THREAD);
530 }
533 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
534 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
535 return NULL;
536 }
539 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
540 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
541 return NULL;
542 }
545 void Klass::with_array_klasses_do(void f(Klass* k)) {
546 f(this);
547 }
550 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
552 const char* Klass::external_name() const {
553 if (oop_is_instance()) {
554 InstanceKlass* ik = (InstanceKlass*) this;
555 if (ik->is_anonymous()) {
556 assert(EnableInvokeDynamic, "");
557 intptr_t hash = ik->java_mirror()->identity_hash();
558 char hash_buf[40];
559 sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
560 size_t hash_len = strlen(hash_buf);
562 size_t result_len = name()->utf8_length();
563 char* result = NEW_RESOURCE_ARRAY(char, result_len + hash_len + 1);
564 name()->as_klass_external_name(result, (int) result_len + 1);
565 assert(strlen(result) == result_len, "");
566 strcpy(result + result_len, hash_buf);
567 assert(strlen(result) == result_len + hash_len, "");
568 return result;
569 }
570 }
571 if (name() == NULL) return "<unknown>";
572 return name()->as_klass_external_name();
573 }
576 const char* Klass::signature_name() const {
577 if (name() == NULL) return "<unknown>";
578 return name()->as_C_string();
579 }
581 // Unless overridden, modifier_flags is 0.
582 jint Klass::compute_modifier_flags(TRAPS) const {
583 return 0;
584 }
586 int Klass::atomic_incr_biased_lock_revocation_count() {
587 return (int) Atomic::add(1, &_biased_lock_revocation_count);
588 }
590 // Unless overridden, jvmti_class_status has no flags set.
591 jint Klass::jvmti_class_status() const {
592 return 0;
593 }
596 // Printing
598 void Klass::print_on(outputStream* st) const {
599 ResourceMark rm;
600 // print title
601 st->print("%s", internal_name());
602 print_address_on(st);
603 st->cr();
604 }
606 void Klass::oop_print_on(oop obj, outputStream* st) {
607 ResourceMark rm;
608 // print title
609 st->print_cr("%s ", internal_name());
610 obj->print_address_on(st);
612 if (WizardMode) {
613 // print header
614 obj->mark()->print_on(st);
615 }
617 // print class
618 st->print(" - klass: ");
619 obj->klass()->print_value_on(st);
620 st->cr();
621 }
623 void Klass::oop_print_value_on(oop obj, outputStream* st) {
624 // print title
625 ResourceMark rm; // Cannot print in debug mode without this
626 st->print("%s", internal_name());
627 obj->print_address_on(st);
628 }
631 // Verification
633 void Klass::verify_on(outputStream* st) {
634 guarantee(!Universe::heap()->is_in_reserved(this), "Shouldn't be");
635 guarantee(this->is_metadata(), "should be in metaspace");
637 assert(ClassLoaderDataGraph::contains((address)this), "Should be");
639 guarantee(this->is_klass(),"should be klass");
641 if (super() != NULL) {
642 guarantee(super()->is_metadata(), "should be in metaspace");
643 guarantee(super()->is_klass(), "should be klass");
644 }
645 if (secondary_super_cache() != NULL) {
646 Klass* ko = secondary_super_cache();
647 guarantee(ko->is_metadata(), "should be in metaspace");
648 guarantee(ko->is_klass(), "should be klass");
649 }
650 for ( uint i = 0; i < primary_super_limit(); i++ ) {
651 Klass* ko = _primary_supers[i];
652 if (ko != NULL) {
653 guarantee(ko->is_metadata(), "should be in metaspace");
654 guarantee(ko->is_klass(), "should be klass");
655 }
656 }
658 if (java_mirror() != NULL) {
659 guarantee(java_mirror()->is_oop(), "should be instance");
660 }
661 }
663 void Klass::oop_verify_on(oop obj, outputStream* st) {
664 guarantee(obj->is_oop(), "should be oop");
665 guarantee(obj->klass()->is_metadata(), "should not be in Java heap");
666 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
667 }
669 #ifndef PRODUCT
671 void Klass::verify_vtable_index(int i) {
672 if (oop_is_instance()) {
673 assert(i>=0 && i<((InstanceKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds");
674 } else {
675 assert(oop_is_array(), "Must be");
676 assert(i>=0 && i<((ArrayKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds");
677 }
678 }
680 #endif