forked from openjdk/jdk11u-dev
-
Notifications
You must be signed in to change notification settings - Fork 0
/
constantPool.cpp
2615 lines (2338 loc) · 94.7 KB
/
constantPool.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "jvm.h"
#include "classfile/classLoaderData.hpp"
#include "classfile/javaClasses.inline.hpp"
#include "classfile/metadataOnStackMark.hpp"
#include "classfile/stringTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/vmSymbols.hpp"
#include "interpreter/linkResolver.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/heapInspection.hpp"
#include "memory/metadataFactory.hpp"
#include "memory/metaspaceClosure.hpp"
#include "memory/metaspaceShared.hpp"
#include "memory/oopFactory.hpp"
#include "memory/resourceArea.hpp"
#include "oops/array.inline.hpp"
#include "oops/constantPool.inline.hpp"
#include "oops/cpCache.inline.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/objArrayKlass.hpp"
#include "oops/objArrayOop.inline.hpp"
#include "oops/oop.inline.hpp"
#include "oops/typeArrayOop.inline.hpp"
#include "runtime/fieldType.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/init.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/signature.hpp"
#include "runtime/vframe.inline.hpp"
#include "utilities/copy.hpp"
constantTag ConstantPool::tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
void ConstantPool::release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); }
ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
Array<u1>* tags = MetadataFactory::new_array<u1>(loader_data, length, 0, CHECK_NULL);
int size = ConstantPool::size(length);
return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
}
#ifdef ASSERT
// MetaspaceObj allocation invariant is calloc equivalent memory
// simple verification of this here (JVM_CONSTANT_Invalid == 0 )
static bool tag_array_is_zero_initialized(Array<u1>* tags) {
assert(tags != NULL, "invariant");
const int length = tags->length();
for (int index = 0; index < length; ++index) {
if (JVM_CONSTANT_Invalid != tags->at(index)) {
return false;
}
}
return true;
}
#endif
ConstantPool::ConstantPool(Array<u1>* tags) :
_tags(tags),
_length(tags->length()) {
assert(_tags != NULL, "invariant");
assert(tags->length() == _length, "invariant");
assert(tag_array_is_zero_initialized(tags), "invariant");
assert(0 == flags(), "invariant");
assert(0 == version(), "invariant");
assert(NULL == _pool_holder, "invariant");
}
void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
if (cache() != NULL) {
MetadataFactory::free_metadata(loader_data, cache());
set_cache(NULL);
}
MetadataFactory::free_array<Klass*>(loader_data, resolved_klasses());
set_resolved_klasses(NULL);
MetadataFactory::free_array<jushort>(loader_data, operands());
set_operands(NULL);
release_C_heap_structures();
// free tag array
MetadataFactory::free_array<u1>(loader_data, tags());
set_tags(NULL);
}
void ConstantPool::release_C_heap_structures() {
// walk constant pool and decrement symbol reference counts
unreference_symbols();
}
void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) {
log_trace(cds)("Iter(ConstantPool): %p", this);
it->push(&_tags, MetaspaceClosure::_writable);
it->push(&_cache);
it->push(&_pool_holder);
it->push(&_operands);
it->push(&_resolved_klasses, MetaspaceClosure::_writable);
for (int i = 0; i < length(); i++) {
// The only MSO's embedded in the CP entries are Symbols:
// JVM_CONSTANT_String (normal and pseudo)
// JVM_CONSTANT_Utf8
constantTag ctag = tag_at(i);
if (ctag.is_string() || ctag.is_utf8()) {
it->push(symbol_at_addr(i));
}
}
}
objArrayOop ConstantPool::resolved_references() const {
return (objArrayOop)_cache->resolved_references();
}
// Called from outside constant pool resolution where a resolved_reference array
// may not be present.
objArrayOop ConstantPool::resolved_references_or_null() const {
if (_cache == NULL) {
return NULL;
} else {
return (objArrayOop)_cache->resolved_references();
}
}
// Create resolved_references array and mapping array for original cp indexes
// The ldc bytecode was rewritten to have the resolved reference array index so need a way
// to map it back for resolving and some unlikely miscellaneous uses.
// The objects created by invokedynamic are appended to this list.
void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
const intStack& reference_map,
int constant_pool_map_length,
TRAPS) {
// Initialized the resolved object cache.
int map_length = reference_map.length();
if (map_length > 0) {
// Only need mapping back to constant pool entries. The map isn't used for
// invokedynamic resolved_reference entries. For invokedynamic entries,
// the constant pool cache index has the mapping back to both the constant
// pool and to the resolved reference index.
if (constant_pool_map_length > 0) {
Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
for (int i = 0; i < constant_pool_map_length; i++) {
int x = reference_map.at(i);
assert(x == (int)(jushort) x, "klass index is too big");
om->at_put(i, (jushort)x);
}
set_reference_map(om);
}
// Create Java array for holding resolved strings, methodHandles,
// methodTypes, invokedynamic and invokehandle appendix objects, etc.
objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
Handle refs_handle (THREAD, (oop)stom); // must handleize.
set_resolved_references(loader_data->add_handle(refs_handle));
}
}
void ConstantPool::allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS) {
// A ConstantPool can't possibly have 0xffff valid class entries,
// because entry #0 must be CONSTANT_Invalid, and each class entry must refer to a UTF8
// entry for the class's name. So at most we will have 0xfffe class entries.
// This allows us to use 0xffff (ConstantPool::_temp_resolved_klass_index) to indicate
// UnresolvedKlass entries that are temporarily created during class redefinition.
assert(num_klasses < CPKlassSlot::_temp_resolved_klass_index, "sanity");
assert(resolved_klasses() == NULL, "sanity");
Array<Klass*>* rk = MetadataFactory::new_array<Klass*>(loader_data, num_klasses, CHECK);
set_resolved_klasses(rk);
}
void ConstantPool::initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS) {
int len = length();
int num_klasses = 0;
for (int i = 1; i <len; i++) {
switch (tag_at(i).value()) {
case JVM_CONSTANT_ClassIndex:
{
const int class_index = klass_index_at(i);
unresolved_klass_at_put(i, class_index, num_klasses++);
}
break;
#ifndef PRODUCT
case JVM_CONSTANT_Class:
case JVM_CONSTANT_UnresolvedClass:
case JVM_CONSTANT_UnresolvedClassInError:
// All of these should have been reverted back to ClassIndex before calling
// this function.
ShouldNotReachHere();
#endif
}
}
allocate_resolved_klasses(loader_data, num_klasses, THREAD);
}
// Anonymous class support:
void ConstantPool::klass_at_put(int class_index, int name_index, int resolved_klass_index, Klass* k, Symbol* name) {
assert(is_within_bounds(class_index), "index out of bounds");
assert(is_within_bounds(name_index), "index out of bounds");
assert((resolved_klass_index & 0xffff0000) == 0, "must be");
*int_at_addr(class_index) =
build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
symbol_at_put(name_index, name);
name->increment_refcount();
Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
OrderAccess::release_store(adr, k);
// The interpreter assumes when the tag is stored, the klass is resolved
// and the Klass* non-NULL, so we need hardware store ordering here.
if (k != NULL) {
release_tag_at_put(class_index, JVM_CONSTANT_Class);
} else {
release_tag_at_put(class_index, JVM_CONSTANT_UnresolvedClass);
}
}
// Anonymous class support:
void ConstantPool::klass_at_put(int class_index, Klass* k) {
assert(k != NULL, "must be valid klass");
CPKlassSlot kslot = klass_slot_at(class_index);
int resolved_klass_index = kslot.resolved_klass_index();
Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
OrderAccess::release_store(adr, k);
// The interpreter assumes when the tag is stored, the klass is resolved
// and the Klass* non-NULL, so we need hardware store ordering here.
release_tag_at_put(class_index, JVM_CONSTANT_Class);
}
#if INCLUDE_CDS_JAVA_HEAP
// Archive the resolved references
void ConstantPool::archive_resolved_references(Thread* THREAD) {
if (_cache == NULL) {
return; // nothing to do
}
InstanceKlass *ik = pool_holder();
if (!(ik->is_shared_boot_class() || ik->is_shared_platform_class() ||
ik->is_shared_app_class())) {
// Archiving resolved references for classes from non-builtin loaders
// is not yet supported.
set_resolved_references(NULL);
return;
}
objArrayOop rr = resolved_references();
Array<u2>* ref_map = reference_map();
if (rr != NULL) {
int ref_map_len = ref_map == NULL ? 0 : ref_map->length();
int rr_len = rr->length();
for (int i = 0; i < rr_len; i++) {
oop p = rr->obj_at(i);
rr->obj_at_put(i, NULL);
if (p != NULL && i < ref_map_len) {
int index = object_to_cp_index(i);
// Skip the entry if the string hash code is 0 since the string
// is not included in the shared string_table, see StringTable::copy_shared_string.
if (tag_at(index).is_string() && java_lang_String::hash_code(p) != 0) {
oop op = StringTable::create_archived_string(p, THREAD);
// If the String object is not archived (possibly too large),
// NULL is returned. Also set it in the array, so we won't
// have a 'bad' reference in the archived resolved_reference
// array.
rr->obj_at_put(i, op);
}
}
}
oop archived = MetaspaceShared::archive_heap_object(rr, THREAD);
// If the resolved references array is not archived (too large),
// the 'archived' object is NULL. No need to explicitly check
// the return value of archive_heap_object here. At runtime, the
// resolved references will be created using the normal process
// when there is no archived value.
_cache->set_archived_references(archived);
set_resolved_references(NULL);
}
}
void ConstantPool::resolve_class_constants(TRAPS) {
assert(DumpSharedSpaces, "used during dump time only");
// The _cache may be NULL if the _pool_holder klass fails verification
// at dump time due to missing dependencies.
if (cache() == NULL || reference_map() == NULL) {
return; // nothing to do
}
constantPoolHandle cp(THREAD, this);
for (int index = 1; index < length(); index++) { // Index 0 is unused
if (tag_at(index).is_string() && !cp->is_pseudo_string_at(index)) {
int cache_index = cp->cp_to_object_index(index);
string_at_impl(cp, index, cache_index, CHECK);
}
}
}
#endif
// CDS support. Create a new resolved_references array.
void ConstantPool::restore_unshareable_info(TRAPS) {
if (!_pool_holder->is_linked() && !_pool_holder->is_rewritten()) {
return;
}
assert(is_constantPool(), "ensure C++ vtable is restored");
assert(on_stack(), "should always be set for shared constant pools");
assert(is_shared(), "should always be set for shared constant pools");
assert(_cache != NULL, "constant pool _cache should not be NULL");
// Only create the new resolved references array if it hasn't been attempted before
if (resolved_references() != NULL) return;
// restore the C++ vtable from the shared archive
restore_vtable();
if (SystemDictionary::Object_klass_loaded()) {
ClassLoaderData* loader_data = pool_holder()->class_loader_data();
#if INCLUDE_CDS_JAVA_HEAP
if (MetaspaceShared::open_archive_heap_region_mapped() &&
_cache->archived_references() != NULL) {
oop archived = _cache->archived_references();
// Create handle for the archived resolved reference array object
Handle refs_handle(THREAD, archived);
set_resolved_references(loader_data->add_handle(refs_handle));
} else
#endif
{
// No mapped archived resolved reference array
// Recreate the object array and add to ClassLoaderData.
int map_length = resolved_reference_length();
if (map_length > 0) {
objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
Handle refs_handle(THREAD, (oop)stom); // must handleize.
set_resolved_references(loader_data->add_handle(refs_handle));
}
}
}
}
void ConstantPool::remove_unshareable_info() {
if (!_pool_holder->is_linked() && !_pool_holder->verified_at_dump_time()) {
return;
}
// Resolved references are not in the shared archive.
// Save the length for restoration. It is not necessarily the same length
// as reference_map.length() if invokedynamic is saved. It is needed when
// re-creating the resolved reference array if archived heap data cannot be map
// at runtime.
set_resolved_reference_length(
resolved_references() != NULL ? resolved_references()->length() : 0);
// If archiving heap objects is not allowed, clear the resolved references.
// Otherwise, it is cleared after the resolved references array is cached
// (see archive_resolved_references()).
if (!MetaspaceShared::is_heap_object_archiving_allowed()) {
set_resolved_references(NULL);
}
// Shared ConstantPools are in the RO region, so the _flags cannot be modified.
// The _on_stack flag is used to prevent ConstantPools from deallocation during
// class redefinition. Since shared ConstantPools cannot be deallocated anyway,
// we always set _on_stack to true to avoid having to change _flags during runtime.
_flags |= (_on_stack | _is_shared);
int num_klasses = 0;
for (int index = 1; index < length(); index++) { // Index 0 is unused
assert(!tag_at(index).is_unresolved_klass_in_error(), "This must not happen during dump time");
if (tag_at(index).is_klass()) {
// This class was resolved as a side effect of executing Java code
// during dump time. We need to restore it back to an UnresolvedClass,
// so that the proper class loading and initialization can happen
// at runtime.
CPKlassSlot kslot = klass_slot_at(index);
int resolved_klass_index = kslot.resolved_klass_index();
int name_index = kslot.name_index();
assert(tag_at(name_index).is_symbol(), "sanity");
resolved_klasses()->at_put(resolved_klass_index, NULL);
tag_at_put(index, JVM_CONSTANT_UnresolvedClass);
assert(klass_name_at(index) == symbol_at(name_index), "sanity");
}
}
if (cache() != NULL) {
cache()->remove_unshareable_info();
}
}
int ConstantPool::cp_to_object_index(int cp_index) {
// this is harder don't do this so much.
int i = reference_map()->find(cp_index);
// We might not find the index for jsr292 call.
return (i < 0) ? _no_index_sentinel : i;
}
void ConstantPool::string_at_put(int which, int obj_index, oop str) {
resolved_references()->obj_at_put(obj_index, str);
}
void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
ResourceMark rm;
int line_number = -1;
const char * source_file = NULL;
if (JavaThread::current()->has_last_Java_frame()) {
// try to identify the method which called this function.
vframeStream vfst(JavaThread::current());
if (!vfst.at_end()) {
line_number = vfst.method()->line_number_from_bci(vfst.bci());
Symbol* s = vfst.method()->method_holder()->source_file_name();
if (s != NULL) {
source_file = s->as_C_string();
}
}
}
if (k != this_cp->pool_holder()) {
// only print something if the classes are different
if (source_file != NULL) {
log_debug(class, resolve)("%s %s %s:%d",
this_cp->pool_holder()->external_name(),
k->external_name(), source_file, line_number);
} else {
log_debug(class, resolve)("%s %s",
this_cp->pool_holder()->external_name(),
k->external_name());
}
}
}
Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int which,
bool save_resolution_error, TRAPS) {
assert(THREAD->is_Java_thread(), "must be a Java thread");
// A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
// It is not safe to rely on the tag bit's here, since we don't have a lock, and
// the entry and tag is not updated atomicly.
CPKlassSlot kslot = this_cp->klass_slot_at(which);
int resolved_klass_index = kslot.resolved_klass_index();
int name_index = kslot.name_index();
assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
if (klass != NULL) {
return klass;
}
// This tag doesn't change back to unresolved class unless at a safepoint.
if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
// The original attempt to resolve this constant pool entry failed so find the
// class of the original error and throw another error of the same class
// (JVMS 5.4.3).
// If there is a detail message, pass that detail message to the error.
// The JVMS does not strictly require us to duplicate the same detail message,
// or any internal exception fields such as cause or stacktrace. But since the
// detail message is often a class name or other literal string, we will repeat it
// if we can find it in the symbol table.
throw_resolution_error(this_cp, which, CHECK_0);
ShouldNotReachHere();
}
Handle mirror_handle;
Symbol* name = this_cp->symbol_at(name_index);
Handle loader (THREAD, this_cp->pool_holder()->class_loader());
Handle protection_domain (THREAD, this_cp->pool_holder()->protection_domain());
Klass* k = SystemDictionary::resolve_or_fail(name, loader, protection_domain, true, THREAD);
if (!HAS_PENDING_EXCEPTION) {
// preserve the resolved klass from unloading
mirror_handle = Handle(THREAD, k->java_mirror());
// Do access check for klasses
verify_constant_pool_resolve(this_cp, k, THREAD);
}
// Failed to resolve class. We must record the errors so that subsequent attempts
// to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
if (HAS_PENDING_EXCEPTION) {
if (save_resolution_error) {
save_and_throw_exception(this_cp, which, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
// If CHECK_NULL above doesn't return the exception, that means that
// some other thread has beaten us and has resolved the class.
// To preserve old behavior, we return the resolved class.
klass = this_cp->resolved_klasses()->at(resolved_klass_index);
assert(klass != NULL, "must be resolved if exception was cleared");
return klass;
} else {
return NULL; // return the pending exception
}
}
// logging for class+resolve.
if (log_is_enabled(Debug, class, resolve)){
trace_class_resolution(this_cp, k);
}
Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
OrderAccess::release_store(adr, k);
// The interpreter assumes when the tag is stored, the klass is resolved
// and the Klass* stored in _resolved_klasses is non-NULL, so we need
// hardware store ordering here.
this_cp->release_tag_at_put(which, JVM_CONSTANT_Class);
return k;
}
// Does not update ConstantPool* - to avoid any exception throwing. Used
// by compiler and exception handling. Also used to avoid classloads for
// instanceof operations. Returns NULL if the class has not been loaded or
// if the verification of constant pool failed
Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
CPKlassSlot kslot = this_cp->klass_slot_at(which);
int resolved_klass_index = kslot.resolved_klass_index();
int name_index = kslot.name_index();
assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
if (k != NULL) {
return k;
} else {
Thread *thread = Thread::current();
Symbol* name = this_cp->symbol_at(name_index);
oop loader = this_cp->pool_holder()->class_loader();
oop protection_domain = this_cp->pool_holder()->protection_domain();
Handle h_prot (thread, protection_domain);
Handle h_loader (thread, loader);
Klass* k = SystemDictionary::find(name, h_loader, h_prot, thread);
if (k != NULL) {
// Make sure that resolving is legal
EXCEPTION_MARK;
// return NULL if verification fails
verify_constant_pool_resolve(this_cp, k, THREAD);
if (HAS_PENDING_EXCEPTION) {
CLEAR_PENDING_EXCEPTION;
return NULL;
}
return k;
} else {
return k;
}
}
}
Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
int which) {
if (cpool->cache() == NULL) return NULL; // nothing to load yet
int cache_index = decode_cpcache_index(which, true);
if (!(cache_index >= 0 && cache_index < cpool->cache()->length())) {
// FIXME: should be an assert
log_debug(class, resolve)("bad operand %d in:", which); cpool->print();
return NULL;
}
ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
return e->method_if_resolved(cpool);
}
bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which) {
if (cpool->cache() == NULL) return false; // nothing to load yet
int cache_index = decode_cpcache_index(which, true);
ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
return e->has_appendix();
}
oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which) {
if (cpool->cache() == NULL) return NULL; // nothing to load yet
int cache_index = decode_cpcache_index(which, true);
ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
return e->appendix_if_resolved(cpool);
}
bool ConstantPool::has_method_type_at_if_loaded(const constantPoolHandle& cpool, int which) {
if (cpool->cache() == NULL) return false; // nothing to load yet
int cache_index = decode_cpcache_index(which, true);
ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
return e->has_method_type();
}
oop ConstantPool::method_type_at_if_loaded(const constantPoolHandle& cpool, int which) {
if (cpool->cache() == NULL) return NULL; // nothing to load yet
int cache_index = decode_cpcache_index(which, true);
ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
return e->method_type_if_resolved(cpool);
}
Symbol* ConstantPool::impl_name_ref_at(int which, bool uncached) {
int name_index = name_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
return symbol_at(name_index);
}
Symbol* ConstantPool::impl_signature_ref_at(int which, bool uncached) {
int signature_index = signature_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
return symbol_at(signature_index);
}
int ConstantPool::impl_name_and_type_ref_index_at(int which, bool uncached) {
int i = which;
if (!uncached && cache() != NULL) {
if (ConstantPool::is_invokedynamic_index(which)) {
// Invokedynamic index is index into the constant pool cache
int pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index();
pool_index = invoke_dynamic_name_and_type_ref_index_at(pool_index);
assert(tag_at(pool_index).is_name_and_type(), "");
return pool_index;
}
// change byte-ordering and go via cache
i = remap_instruction_operand_from_cache(which);
} else {
if (tag_at(which).is_invoke_dynamic() ||
tag_at(which).is_dynamic_constant() ||
tag_at(which).is_dynamic_constant_in_error()) {
int pool_index = invoke_dynamic_name_and_type_ref_index_at(which);
assert(tag_at(pool_index).is_name_and_type(), "");
return pool_index;
}
}
assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
assert(!tag_at(i).is_invoke_dynamic() &&
!tag_at(i).is_dynamic_constant() &&
!tag_at(i).is_dynamic_constant_in_error(), "Must be handled above");
jint ref_index = *int_at_addr(i);
return extract_high_short_from_int(ref_index);
}
constantTag ConstantPool::impl_tag_ref_at(int which, bool uncached) {
int pool_index = which;
if (!uncached && cache() != NULL) {
if (ConstantPool::is_invokedynamic_index(which)) {
// Invokedynamic index is index into resolved_references
pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index();
} else {
// change byte-ordering and go via cache
pool_index = remap_instruction_operand_from_cache(which);
}
}
return tag_at(pool_index);
}
int ConstantPool::impl_klass_ref_index_at(int which, bool uncached) {
guarantee(!ConstantPool::is_invokedynamic_index(which),
"an invokedynamic instruction does not have a klass");
int i = which;
if (!uncached && cache() != NULL) {
// change byte-ordering and go via cache
i = remap_instruction_operand_from_cache(which);
}
assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
jint ref_index = *int_at_addr(i);
return extract_low_short_from_int(ref_index);
}
int ConstantPool::remap_instruction_operand_from_cache(int operand) {
int cpc_index = operand;
DEBUG_ONLY(cpc_index -= CPCACHE_INDEX_TAG);
assert((int)(u2)cpc_index == cpc_index, "clean u2");
int member_index = cache()->entry_at(cpc_index)->constant_pool_index();
return member_index;
}
void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
if (!(k->is_instance_klass() || k->is_objArray_klass())) {
return; // short cut, typeArray klass is always accessible
}
Klass* holder = this_cp->pool_holder();
bool fold_type_to_class = true;
LinkResolver::check_klass_accessability(holder, k, fold_type_to_class, CHECK);
}
int ConstantPool::name_ref_index_at(int which_nt) {
jint ref_index = name_and_type_at(which_nt);
return extract_low_short_from_int(ref_index);
}
int ConstantPool::signature_ref_index_at(int which_nt) {
jint ref_index = name_and_type_at(which_nt);
return extract_high_short_from_int(ref_index);
}
Klass* ConstantPool::klass_ref_at(int which, TRAPS) {
return klass_at(klass_ref_index_at(which), THREAD);
}
Symbol* ConstantPool::klass_name_at(int which) const {
return symbol_at(klass_slot_at(which).name_index());
}
Symbol* ConstantPool::klass_ref_at_noresolve(int which) {
jint ref_index = klass_ref_index_at(which);
return klass_at_noresolve(ref_index);
}
Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int which) {
jint ref_index = uncached_klass_ref_index_at(which);
return klass_at_noresolve(ref_index);
}
char* ConstantPool::string_at_noresolve(int which) {
return unresolved_string_at(which)->as_C_string();
}
BasicType ConstantPool::basic_type_for_signature_at(int which) const {
return FieldType::basic_type(symbol_at(which));
}
void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
if (this_cp->tag_at(index).is_string()) {
this_cp->string_at(index, CHECK);
}
}
}
Symbol* ConstantPool::exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
// Dig out the detailed message to reuse if possible
Symbol* message = java_lang_Throwable::detail_message(pending_exception);
if (message != NULL) {
return message;
}
// Return specific message for the tag
switch (tag.value()) {
case JVM_CONSTANT_UnresolvedClass:
// return the class name in the error message
message = this_cp->klass_name_at(which);
break;
case JVM_CONSTANT_MethodHandle:
// return the method handle name in the error message
message = this_cp->method_handle_name_ref_at(which);
break;
case JVM_CONSTANT_MethodType:
// return the method type signature in the error message
message = this_cp->method_type_signature_at(which);
break;
case JVM_CONSTANT_Dynamic:
// return the name of the condy in the error message
message = this_cp->uncached_name_ref_at(which);
break;
default:
ShouldNotReachHere();
}
return message;
}
void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
Symbol* message = NULL;
Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message);
assert(error != NULL && message != NULL, "checking");
CLEAR_PENDING_EXCEPTION;
ResourceMark rm;
THROW_MSG(error, message->as_C_string());
}
// If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
// exception in the resolution error table, so that the same exception is thrown again.
void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int which,
constantTag tag, TRAPS) {
Symbol* error = PENDING_EXCEPTION->klass()->name();
int error_tag = tag.error_value();
if (!PENDING_EXCEPTION->
is_a(SystemDictionary::LinkageError_klass())) {
// Just throw the exception and don't prevent these classes from
// being loaded due to virtual machine errors like StackOverflow
// and OutOfMemoryError, etc, or if the thread was hit by stop()
// Needs clarification to section 5.4.3 of the VM spec (see 6308271)
} else if (this_cp->tag_at(which).value() != error_tag) {
Symbol* message = exception_message(this_cp, which, tag, PENDING_EXCEPTION);
SystemDictionary::add_resolution_error(this_cp, which, error, message);
// CAS in the tag. If a thread beat us to registering this error that's fine.
// If another thread resolved the reference, this is a race condition. This
// thread may have had a security manager or something temporary.
// This doesn't deterministically get an error. So why do we save this?
// We save this because jvmti can add classes to the bootclass path after
// this error, so it needs to get the same error if the error is first.
jbyte old_tag = Atomic::cmpxchg((jbyte)error_tag,
(jbyte*)this_cp->tag_addr_at(which), (jbyte)tag.value());
if (old_tag != error_tag && old_tag != tag.value()) {
// MethodHandles and MethodType doesn't change to resolved version.
assert(this_cp->tag_at(which).is_klass(), "Wrong tag value");
// Forget the exception and use the resolved class.
CLEAR_PENDING_EXCEPTION;
}
} else {
// some other thread put this in error state
throw_resolution_error(this_cp, which, CHECK);
}
}
constantTag ConstantPool::constant_tag_at(int which) {
constantTag tag = tag_at(which);
if (tag.is_dynamic_constant() ||
tag.is_dynamic_constant_in_error()) {
BasicType bt = basic_type_for_constant_at(which);
// dynamic constant could return an array, treat as object
return constantTag::ofBasicType(is_reference_type(bt) ? T_OBJECT : bt);
}
return tag;
}
BasicType ConstantPool::basic_type_for_constant_at(int which) {
constantTag tag = tag_at(which);
if (tag.is_dynamic_constant() ||
tag.is_dynamic_constant_in_error()) {
// have to look at the signature for this one
Symbol* constant_type = uncached_signature_ref_at(which);
return FieldType::basic_type(constant_type);
}
return tag.basic_type();
}
// Called to resolve constants in the constant pool and return an oop.
// Some constant pool entries cache their resolved oop. This is also
// called to create oops from constants to use in arguments for invokedynamic
oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
int index, int cache_index,
bool* status_return, TRAPS) {
oop result_oop = NULL;
Handle throw_exception;
if (cache_index == _possible_index_sentinel) {
// It is possible that this constant is one which is cached in the objects.
// We'll do a linear search. This should be OK because this usage is rare.
// FIXME: If bootstrap specifiers stress this code, consider putting in
// a reverse index. Binary search over a short array should do it.
assert(index > 0, "valid index");
cache_index = this_cp->cp_to_object_index(index);
}
assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
assert(index == _no_index_sentinel || index >= 0, "");
if (cache_index >= 0) {
result_oop = this_cp->resolved_references()->obj_at(cache_index);
if (result_oop != NULL) {
if (result_oop == Universe::the_null_sentinel()) {
DEBUG_ONLY(int temp_index = (index >= 0 ? index : this_cp->object_to_cp_index(cache_index)));
assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
result_oop = NULL;
}
if (status_return != NULL) (*status_return) = true;
return result_oop;
// That was easy...
}
index = this_cp->object_to_cp_index(cache_index);
}
jvalue prim_value; // temp used only in a few cases below
constantTag tag = this_cp->tag_at(index);
if (status_return != NULL) {
// don't trigger resolution if the constant might need it
switch (tag.value()) {
case JVM_CONSTANT_Class:
{
CPKlassSlot kslot = this_cp->klass_slot_at(index);
int resolved_klass_index = kslot.resolved_klass_index();
if (this_cp->resolved_klasses()->at(resolved_klass_index) == NULL) {
(*status_return) = false;
return NULL;
}
// the klass is waiting in the CP; go get it
break;
}
case JVM_CONSTANT_String:
case JVM_CONSTANT_Integer:
case JVM_CONSTANT_Float:
case JVM_CONSTANT_Long:
case JVM_CONSTANT_Double:
// these guys trigger OOM at worst
break;
default:
(*status_return) = false;
return NULL;
}
// from now on there is either success or an OOME
(*status_return) = true;
}
switch (tag.value()) {
case JVM_CONSTANT_UnresolvedClass:
case JVM_CONSTANT_UnresolvedClassInError:
case JVM_CONSTANT_Class:
{
assert(cache_index == _no_index_sentinel, "should not have been set");
Klass* resolved = klass_at_impl(this_cp, index, true, CHECK_NULL);
// ldc wants the java mirror.
result_oop = resolved->java_mirror();
break;
}
case JVM_CONSTANT_Dynamic:
{
Klass* current_klass = this_cp->pool_holder();
Symbol* constant_name = this_cp->uncached_name_ref_at(index);
Symbol* constant_type = this_cp->uncached_signature_ref_at(index);
// The initial step in resolving an unresolved symbolic reference to a
// dynamically-computed constant is to resolve the symbolic reference to a
// method handle which will be the bootstrap method for the dynamically-computed
// constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
// method fails, then a MethodHandleInError is stored at the corresponding
// bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
// set a DynamicConstantInError here since any subsequent use of this
// bootstrap method will encounter the resolution of MethodHandleInError.
oop bsm_info = this_cp->resolve_bootstrap_specifier_at(index, THREAD);
Exceptions::wrap_dynamic_exception(CHECK_NULL);
assert(bsm_info != NULL, "");
// FIXME: Cache this once per BootstrapMethods entry, not once per CONSTANT_Dynamic.
Handle bootstrap_specifier = Handle(THREAD, bsm_info);
// Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
Handle value = SystemDictionary::link_dynamic_constant(current_klass,
index,
bootstrap_specifier,
constant_name,
constant_type,
THREAD);
result_oop = value();
Exceptions::wrap_dynamic_exception(THREAD);
if (HAS_PENDING_EXCEPTION) {
// Resolution failure of the dynamically-computed constant, save_and_throw_exception
// will check for a LinkageError and store a DynamicConstantInError.
save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
}
BasicType type = FieldType::basic_type(constant_type);
if (!is_reference_type(type)) {
// Make sure the primitive value is properly boxed.
// This is a JDK responsibility.
const char* fail = NULL;
if (result_oop == NULL) {
fail = "null result instead of box";
} else if (!is_java_primitive(type)) {
// FIXME: support value types via unboxing
fail = "can only handle references and primitives";
} else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
fail = "primitive is not properly boxed";
}
if (fail != NULL) {
// Since this exception is not a LinkageError, throw exception
// but do not save a DynamicInError resolution result.
// See section 5.4.3 of the VM spec.
THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
}
}
break;
}
case JVM_CONSTANT_String:
assert(cache_index != _no_index_sentinel, "should have been set");
if (this_cp->is_pseudo_string_at(index)) {
result_oop = this_cp->pseudo_string_at(index, cache_index);
break;
}
result_oop = string_at_impl(this_cp, index, cache_index, CHECK_NULL);
break;
case JVM_CONSTANT_DynamicInError:
case JVM_CONSTANT_MethodHandleInError:
case JVM_CONSTANT_MethodTypeInError:
{
throw_resolution_error(this_cp, index, CHECK_NULL);
break;
}
case JVM_CONSTANT_MethodHandle:
{
int ref_kind = this_cp->method_handle_ref_kind_at(index);