1 /*
2 * Copyright (c) 1997, 2013, 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/javaClasses.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/verifier.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "gc_implementation/shared/markSweep.inline.hpp"
32 #include "gc_interface/collectedHeap.inline.hpp"
33 #include "interpreter/oopMapCache.hpp"
34 #include "interpreter/rewriter.hpp"
35 #include "jvmtifiles/jvmti.h"
36 #include "memory/genOopClosures.inline.hpp"
37 #include "memory/heapInspection.hpp"
38 #include "memory/metadataFactory.hpp"
39 #include "memory/oopFactory.hpp"
40 #include "oops/fieldStreams.hpp"
41 #include "oops/instanceClassLoaderKlass.hpp"
42 #include "oops/instanceKlass.hpp"
43 #include "oops/instanceMirrorKlass.hpp"
44 #include "oops/instanceOop.hpp"
45 #include "oops/klass.inline.hpp"
46 #include "oops/method.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "oops/symbol.hpp"
49 #include "prims/jvmtiExport.hpp"
50 #include "prims/jvmtiRedefineClassesTrace.hpp"
51 #include "prims/methodComparator.hpp"
52 #include "runtime/fieldDescriptor.hpp"
53 #include "runtime/handles.inline.hpp"
54 #include "runtime/javaCalls.hpp"
55 #include "runtime/mutexLocker.hpp"
56 #include "runtime/thread.inline.hpp"
57 #include "services/threadService.hpp"
58 #include "utilities/dtrace.hpp"
59 #include "utilities/macros.hpp"
60 #if INCLUDE_ALL_GCS
61 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
62 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
63 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
64 #include "gc_implementation/g1/g1RemSet.inline.hpp"
65 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
66 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
67 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
68 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
69 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
70 #include "oops/oop.pcgc.inline.hpp"
71 #endif // INCLUDE_ALL_GCS
72 #ifdef COMPILER1
73 #include "c1/c1_Compiler.hpp"
74 #endif
75
76 #ifdef DTRACE_ENABLED
77
78 #ifndef USDT2
79
80 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
81 char*, intptr_t, oop, intptr_t);
82 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
83 char*, intptr_t, oop, intptr_t, int);
84 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
85 char*, intptr_t, oop, intptr_t, int);
86 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
87 char*, intptr_t, oop, intptr_t, int);
88 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
89 char*, intptr_t, oop, intptr_t, int);
90 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
91 char*, intptr_t, oop, intptr_t, int);
92 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
93 char*, intptr_t, oop, intptr_t, int);
94 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
95 char*, intptr_t, oop, intptr_t, int);
96
97 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
98 { \
99 char* data = NULL; \
100 int len = 0; \
101 Symbol* name = (clss)->name(); \
102 if (name != NULL) { \
103 data = (char*)name->bytes(); \
104 len = name->utf8_length(); \
105 } \
106 HS_DTRACE_PROBE4(hotspot, class__initialization__##type, \
107 data, len, (clss)->class_loader(), thread_type); \
108 }
109
110 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
111 { \
112 char* data = NULL; \
113 int len = 0; \
114 Symbol* name = (clss)->name(); \
115 if (name != NULL) { \
116 data = (char*)name->bytes(); \
117 len = name->utf8_length(); \
118 } \
119 HS_DTRACE_PROBE5(hotspot, class__initialization__##type, \
120 data, len, (clss)->class_loader(), thread_type, wait); \
121 }
122 #else /* USDT2 */
123
124 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
125 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
126 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
127 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
128 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
129 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
130 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
131 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
132 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
133 { \
134 char* data = NULL; \
135 int len = 0; \
136 Symbol* name = (clss)->name(); \
137 if (name != NULL) { \
138 data = (char*)name->bytes(); \
139 len = name->utf8_length(); \
140 } \
141 HOTSPOT_CLASS_INITIALIZATION_##type( \
142 data, len, (clss)->class_loader(), thread_type); \
143 }
144
145 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
146 { \
147 char* data = NULL; \
148 int len = 0; \
149 Symbol* name = (clss)->name(); \
150 if (name != NULL) { \
151 data = (char*)name->bytes(); \
152 len = name->utf8_length(); \
153 } \
154 HOTSPOT_CLASS_INITIALIZATION_##type( \
155 data, len, (clss)->class_loader(), thread_type, wait); \
156 }
157 #endif /* USDT2 */
158
159 #else // ndef DTRACE_ENABLED
160
161 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
162 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
163
164 #endif // ndef DTRACE_ENABLED
165
166 volatile int InstanceKlass::_total_instanceKlass_count = 0;
167
168 InstanceKlass* InstanceKlass::allocate_instance_klass(
169 ClassLoaderData* loader_data,
170 int vtable_len,
171 int itable_len,
172 int static_field_size,
173 int nonstatic_oop_map_size,
174 ReferenceType rt,
175 AccessFlags access_flags,
176 Symbol* name,
177 Klass* super_klass,
178 bool is_anonymous,
179 TRAPS) {
180
181 int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
182 access_flags.is_interface(), is_anonymous);
183
184 // Allocation
185 InstanceKlass* ik;
186 if (rt == REF_NONE) {
187 if (name == vmSymbols::java_lang_Class()) {
188 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
189 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
190 access_flags, is_anonymous);
191 } else if (name == vmSymbols::java_lang_ClassLoader() ||
192 (SystemDictionary::ClassLoader_klass_loaded() &&
193 super_klass != NULL &&
194 super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
195 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
196 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
197 access_flags, is_anonymous);
198 } else {
199 // normal class
200 ik = new (loader_data, size, THREAD) InstanceKlass(
201 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
202 access_flags, is_anonymous);
203 }
204 } else {
205 // reference klass
206 ik = new (loader_data, size, THREAD) InstanceRefKlass(
207 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
208 access_flags, is_anonymous);
209 }
210
211 // Check for pending exception before adding to the loader data and incrementing
212 // class count. Can get OOM here.
213 if (HAS_PENDING_EXCEPTION) {
214 return NULL;
215 }
216
217 // Add all classes to our internal class loader list here,
218 // including classes in the bootstrap (NULL) class loader.
219 loader_data->add_class(ik);
220
221 Atomic::inc(&_total_instanceKlass_count);
222 return ik;
223 }
224
225
226 // copy method ordering from resource area to Metaspace
227 void InstanceKlass::copy_method_ordering(intArray* m, TRAPS) {
228 if (m != NULL) {
229 // allocate a new array and copy contents (memcpy?)
230 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
231 for (int i = 0; i < m->length(); i++) {
232 _method_ordering->at_put(i, m->at(i));
233 }
234 } else {
235 _method_ordering = Universe::the_empty_int_array();
236 }
237 }
238
239
240 InstanceKlass::InstanceKlass(int vtable_len,
241 int itable_len,
242 int static_field_size,
243 int nonstatic_oop_map_size,
244 ReferenceType rt,
245 AccessFlags access_flags,
246 bool is_anonymous) {
247 No_Safepoint_Verifier no_safepoint; // until k becomes parsable
248
249 int iksize = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
250 access_flags.is_interface(), is_anonymous);
251
252 set_vtable_length(vtable_len);
253 set_itable_length(itable_len);
254 set_static_field_size(static_field_size);
255 set_nonstatic_oop_map_size(nonstatic_oop_map_size);
256 set_access_flags(access_flags);
257 _misc_flags = 0; // initialize to zero
258 set_is_anonymous(is_anonymous);
259 assert(size() == iksize, "wrong size for object");
260
261 set_array_klasses(NULL);
262 set_methods(NULL);
263 set_method_ordering(NULL);
264 set_local_interfaces(NULL);
265 set_transitive_interfaces(NULL);
266 init_implementor();
267 set_fields(NULL, 0);
268 set_constants(NULL);
269 set_class_loader_data(NULL);
270 set_protection_domain(NULL);
271 set_signers(NULL);
272 set_source_file_name(NULL);
273 set_source_debug_extension(NULL, 0);
274 set_array_name(NULL);
275 set_inner_classes(NULL);
276 set_static_oop_field_count(0);
277 set_nonstatic_field_size(0);
278 set_is_marked_dependent(false);
279 set_init_state(InstanceKlass::allocated);
280 set_init_thread(NULL);
281 set_per_class_lock(NULL);
282 set_reference_type(rt);
283 set_oop_map_cache(NULL);
284 set_jni_ids(NULL);
285 set_osr_nmethods_head(NULL);
286 set_breakpoints(NULL);
287 init_previous_versions();
288 set_generic_signature(NULL);
289 release_set_methods_jmethod_ids(NULL);
290 release_set_methods_cached_itable_indices(NULL);
291 set_annotations(NULL);
292 set_jvmti_cached_class_field_map(NULL);
293 set_initial_method_idnum(0);
294 _dependencies = NULL;
295 set_jvmti_cached_class_field_map(NULL);
296 set_cached_class_file(NULL, 0);
297 set_initial_method_idnum(0);
298 set_minor_version(0);
299 set_major_version(0);
300 NOT_PRODUCT(_verify_count = 0;)
301
302 // initialize the non-header words to zero
303 intptr_t* p = (intptr_t*)this;
304 for (int index = InstanceKlass::header_size(); index < iksize; index++) {
305 p[index] = NULL_WORD;
306 }
307
308 // Set temporary value until parseClassFile updates it with the real instance
309 // size.
310 set_layout_helper(Klass::instance_layout_helper(0, true));
311 }
312
313
314 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
315 Array<Method*>* methods) {
316 if (methods != NULL && methods != Universe::the_empty_method_array()) {
317 for (int i = 0; i < methods->length(); i++) {
318 Method* method = methods->at(i);
319 if (method == NULL) continue; // maybe null if error processing
320 // Only want to delete methods that are not executing for RedefineClasses.
321 // The previous version will point to them so they're not totally dangling
322 assert (!method->on_stack(), "shouldn't be called with methods on stack");
323 MetadataFactory::free_metadata(loader_data, method);
324 }
325 MetadataFactory::free_array<Method*>(loader_data, methods);
326 }
327 }
328
329 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
330 Klass* super_klass,
331 Array<Klass*>* local_interfaces,
332 Array<Klass*>* transitive_interfaces) {
333 // Only deallocate transitive interfaces if not empty, same as super class
334 // or same as local interfaces. See code in parseClassFile.
335 Array<Klass*>* ti = transitive_interfaces;
336 if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
337 // check that the interfaces don't come from super class
338 Array<Klass*>* sti = (super_klass == NULL) ? NULL :
339 InstanceKlass::cast(super_klass)->transitive_interfaces();
340 if (ti != sti) {
341 MetadataFactory::free_array<Klass*>(loader_data, ti);
342 }
343 }
344
345 // local interfaces can be empty
346 if (local_interfaces != Universe::the_empty_klass_array()) {
347 MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
348 }
349 }
350
351 // This function deallocates the metadata and C heap pointers that the
352 // InstanceKlass points to.
353 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
354
355 // Orphan the mirror first, CMS thinks it's still live.
356 if (java_mirror() != NULL) {
357 java_lang_Class::set_klass(java_mirror(), NULL);
358 }
359
360 // Need to take this class off the class loader data list.
361 loader_data->remove_class(this);
362
363 // The array_klass for this class is created later, after error handling.
364 // For class redefinition, we keep the original class so this scratch class
365 // doesn't have an array class. Either way, assert that there is nothing
366 // to deallocate.
367 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
368
369 // Release C heap allocated data that this might point to, which includes
370 // reference counting symbol names.
371 release_C_heap_structures();
372
373 deallocate_methods(loader_data, methods());
374 set_methods(NULL);
375
376 if (method_ordering() != Universe::the_empty_int_array()) {
377 MetadataFactory::free_array<int>(loader_data, method_ordering());
378 }
379 set_method_ordering(NULL);
380
381 // This array is in Klass, but remove it with the InstanceKlass since
382 // this place would be the only caller and it can share memory with transitive
383 // interfaces.
384 if (secondary_supers() != Universe::the_empty_klass_array() &&
385 secondary_supers() != transitive_interfaces()) {
386 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
387 }
388 set_secondary_supers(NULL);
389
390 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
391 set_transitive_interfaces(NULL);
392 set_local_interfaces(NULL);
393
394 MetadataFactory::free_array<jushort>(loader_data, fields());
395 set_fields(NULL, 0);
396
397 // If a method from a redefined class is using this constant pool, don't
398 // delete it, yet. The new class's previous version will point to this.
399 if (constants() != NULL) {
400 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
401 MetadataFactory::free_metadata(loader_data, constants());
402 set_constants(NULL);
403 }
404
405 if (inner_classes() != Universe::the_empty_short_array()) {
406 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
407 }
408 set_inner_classes(NULL);
409
410 // Null out Java heap objects, although these won't be walked to keep
411 // alive once this InstanceKlass is deallocated.
412 set_protection_domain(NULL);
413 set_signers(NULL);
414 set_per_class_lock(NULL);
415
416 // We should deallocate the Annotations instance
417 MetadataFactory::free_metadata(loader_data, annotations());
418 set_annotations(NULL);
419 }
420
421 bool InstanceKlass::should_be_initialized() const {
422 return !is_initialized();
423 }
424
425 klassVtable* InstanceKlass::vtable() const {
426 return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
427 }
428
429 klassItable* InstanceKlass::itable() const {
430 return new klassItable(instanceKlassHandle(this));
431 }
432
433 void InstanceKlass::eager_initialize(Thread *thread) {
434 if (!EagerInitialization) return;
435
436 if (this->is_not_initialized()) {
437 // abort if the the class has a class initializer
438 if (this->class_initializer() != NULL) return;
439
440 // abort if it is java.lang.Object (initialization is handled in genesis)
441 Klass* super = this->super();
442 if (super == NULL) return;
443
444 // abort if the super class should be initialized
445 if (!InstanceKlass::cast(super)->is_initialized()) return;
446
447 // call body to expose the this pointer
448 instanceKlassHandle this_oop(thread, this);
449 eager_initialize_impl(this_oop);
450 }
451 }
452
453
454 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
455 EXCEPTION_MARK;
456 volatile oop init_lock = this_oop->init_lock();
457 ObjectLocker ol(init_lock, THREAD);
458
459 // abort if someone beat us to the initialization
460 if (!this_oop->is_not_initialized()) return; // note: not equivalent to is_initialized()
461
462 ClassState old_state = this_oop->init_state();
463 link_class_impl(this_oop, true, THREAD);
464 if (HAS_PENDING_EXCEPTION) {
465 CLEAR_PENDING_EXCEPTION;
466 // Abort if linking the class throws an exception.
467
468 // Use a test to avoid redundantly resetting the state if there's
469 // no change. Set_init_state() asserts that state changes make
470 // progress, whereas here we might just be spinning in place.
471 if( old_state != this_oop->_init_state )
472 this_oop->set_init_state (old_state);
473 } else {
474 // linking successfull, mark class as initialized
475 this_oop->set_init_state (fully_initialized);
476 // trace
477 if (TraceClassInitialization) {
478 ResourceMark rm(THREAD);
479 tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
480 }
481 }
482 }
483
484
485 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
486 // process. The step comments refers to the procedure described in that section.
487 // Note: implementation moved to static method to expose the this pointer.
488 void InstanceKlass::initialize(TRAPS) {
489 if (this->should_be_initialized()) {
490 HandleMark hm(THREAD);
491 instanceKlassHandle this_oop(THREAD, this);
492 initialize_impl(this_oop, CHECK);
493 // Note: at this point the class may be initialized
494 // OR it may be in the state of being initialized
495 // in case of recursive initialization!
496 } else {
497 assert(is_initialized(), "sanity check");
498 }
499 }
500
501
502 bool InstanceKlass::verify_code(
503 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
504 // 1) Verify the bytecodes
505 Verifier::Mode mode =
506 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
507 return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
508 }
509
510
511 // Used exclusively by the shared spaces dump mechanism to prevent
512 // classes mapped into the shared regions in new VMs from appearing linked.
513
514 void InstanceKlass::unlink_class() {
515 assert(is_linked(), "must be linked");
516 _init_state = loaded;
517 }
518
519 void InstanceKlass::link_class(TRAPS) {
520 assert(is_loaded(), "must be loaded");
521 if (!is_linked()) {
522 HandleMark hm(THREAD);
523 instanceKlassHandle this_oop(THREAD, this);
524 link_class_impl(this_oop, true, CHECK);
525 }
526 }
527
528 // Called to verify that a class can link during initialization, without
529 // throwing a VerifyError.
530 bool InstanceKlass::link_class_or_fail(TRAPS) {
531 assert(is_loaded(), "must be loaded");
532 if (!is_linked()) {
533 HandleMark hm(THREAD);
534 instanceKlassHandle this_oop(THREAD, this);
535 link_class_impl(this_oop, false, CHECK_false);
536 }
537 return is_linked();
538 }
539
540 bool InstanceKlass::link_class_impl(
541 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
542 // check for error state
543 if (this_oop->is_in_error_state()) {
544 ResourceMark rm(THREAD);
545 THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
546 this_oop->external_name(), false);
547 }
548 // return if already verified
549 if (this_oop->is_linked()) {
550 return true;
551 }
552
553 // Timing
554 // timer handles recursion
555 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
556 JavaThread* jt = (JavaThread*)THREAD;
557
558 // link super class before linking this class
559 instanceKlassHandle super(THREAD, this_oop->super());
560 if (super.not_null()) {
561 if (super->is_interface()) { // check if super class is an interface
562 ResourceMark rm(THREAD);
563 Exceptions::fthrow(
564 THREAD_AND_LOCATION,
565 vmSymbols::java_lang_IncompatibleClassChangeError(),
566 "class %s has interface %s as super class",
567 this_oop->external_name(),
568 super->external_name()
569 );
570 return false;
571 }
572
573 link_class_impl(super, throw_verifyerror, CHECK_false);
574 }
575
576 // link all interfaces implemented by this class before linking this class
577 Array<Klass*>* interfaces = this_oop->local_interfaces();
578 int num_interfaces = interfaces->length();
579 for (int index = 0; index < num_interfaces; index++) {
580 HandleMark hm(THREAD);
581 instanceKlassHandle ih(THREAD, interfaces->at(index));
582 link_class_impl(ih, throw_verifyerror, CHECK_false);
583 }
584
585 // in case the class is linked in the process of linking its superclasses
586 if (this_oop->is_linked()) {
587 return true;
588 }
589
590 // trace only the link time for this klass that includes
591 // the verification time
592 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
593 ClassLoader::perf_class_link_selftime(),
594 ClassLoader::perf_classes_linked(),
595 jt->get_thread_stat()->perf_recursion_counts_addr(),
596 jt->get_thread_stat()->perf_timers_addr(),
597 PerfClassTraceTime::CLASS_LINK);
598
599 // verification & rewriting
600 {
601 volatile oop init_lock = this_oop->init_lock();
602 ObjectLocker ol(init_lock, THREAD);
603 // rewritten will have been set if loader constraint error found
604 // on an earlier link attempt
605 // don't verify or rewrite if already rewritten
606
607 if (!this_oop->is_linked()) {
608 if (!this_oop->is_rewritten()) {
609 {
610 // Timer includes any side effects of class verification (resolution,
611 // etc), but not recursive entry into verify_code().
612 PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
613 ClassLoader::perf_class_verify_selftime(),
614 ClassLoader::perf_classes_verified(),
615 jt->get_thread_stat()->perf_recursion_counts_addr(),
616 jt->get_thread_stat()->perf_timers_addr(),
617 PerfClassTraceTime::CLASS_VERIFY);
618 bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
619 if (!verify_ok) {
620 return false;
621 }
622 }
623
624 // Just in case a side-effect of verify linked this class already
625 // (which can sometimes happen since the verifier loads classes
626 // using custom class loaders, which are free to initialize things)
627 if (this_oop->is_linked()) {
628 return true;
629 }
630
631 // also sets rewritten
632 this_oop->rewrite_class(CHECK_false);
633 }
634
635 // relocate jsrs and link methods after they are all rewritten
636 this_oop->link_methods(CHECK_false);
637
638 // Initialize the vtable and interface table after
639 // methods have been rewritten since rewrite may
640 // fabricate new Method*s.
641 // also does loader constraint checking
642 if (!this_oop()->is_shared()) {
643 ResourceMark rm(THREAD);
644 this_oop->vtable()->initialize_vtable(true, CHECK_false);
645 this_oop->itable()->initialize_itable(true, CHECK_false);
646 }
647 #ifdef ASSERT
648 else {
649 ResourceMark rm(THREAD);
650 this_oop->vtable()->verify(tty, true);
651 // In case itable verification is ever added.
652 // this_oop->itable()->verify(tty, true);
653 }
654 #endif
655 this_oop->set_init_state(linked);
656 if (JvmtiExport::should_post_class_prepare()) {
657 Thread *thread = THREAD;
658 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
659 JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
660 }
661 }
662 }
663 return true;
664 }
665
666
667 // Rewrite the byte codes of all of the methods of a class.
668 // The rewriter must be called exactly once. Rewriting must happen after
669 // verification but before the first method of the class is executed.
670 void InstanceKlass::rewrite_class(TRAPS) {
671 assert(is_loaded(), "must be loaded");
672 instanceKlassHandle this_oop(THREAD, this);
673 if (this_oop->is_rewritten()) {
674 assert(this_oop()->is_shared(), "rewriting an unshared class?");
675 return;
676 }
677 Rewriter::rewrite(this_oop, CHECK);
678 this_oop->set_rewritten();
679 }
680
681 // Now relocate and link method entry points after class is rewritten.
682 // This is outside is_rewritten flag. In case of an exception, it can be
683 // executed more than once.
684 void InstanceKlass::link_methods(TRAPS) {
685 int len = methods()->length();
686 for (int i = len-1; i >= 0; i--) {
687 methodHandle m(THREAD, methods()->at(i));
688
689 // Set up method entry points for compiler and interpreter .
690 m->link_method(m, CHECK);
691
692 // This is for JVMTI and unrelated to relocator but the last thing we do
693 #ifdef ASSERT
694 if (StressMethodComparator) {
695 ResourceMark rm(THREAD);
696 static int nmc = 0;
697 for (int j = i; j >= 0 && j >= i-4; j--) {
698 if ((++nmc % 1000) == 0) tty->print_cr("Have run MethodComparator %d times...", nmc);
699 bool z = MethodComparator::methods_EMCP(m(),
700 methods()->at(j));
701 if (j == i && !z) {
702 tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
703 assert(z, "method must compare equal to itself");
704 }
705 }
706 }
707 #endif //ASSERT
708 }
709 }
710
711
712 void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
713 // Make sure klass is linked (verified) before initialization
714 // A class could already be verified, since it has been reflected upon.
715 this_oop->link_class(CHECK);
716
717 DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
718
719 bool wait = false;
720
721 // refer to the JVM book page 47 for description of steps
722 // Step 1
723 {
724 volatile oop init_lock = this_oop->init_lock();
725 ObjectLocker ol(init_lock, THREAD);
726
727 Thread *self = THREAD; // it's passed the current thread
728
729 // Step 2
730 // If we were to use wait() instead of waitInterruptibly() then
731 // we might end up throwing IE from link/symbol resolution sites
732 // that aren't expected to throw. This would wreak havoc. See 6320309.
733 while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
734 wait = true;
735 ol.waitUninterruptibly(CHECK);
736 }
737
738 // Step 3
739 if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
740 DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
741 return;
742 }
743
744 // Step 4
745 if (this_oop->is_initialized()) {
746 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
747 return;
748 }
749
750 // Step 5
751 if (this_oop->is_in_error_state()) {
752 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
753 ResourceMark rm(THREAD);
754 const char* desc = "Could not initialize class ";
755 const char* className = this_oop->external_name();
756 size_t msglen = strlen(desc) + strlen(className) + 1;
757 char* message = NEW_RESOURCE_ARRAY(char, msglen);
758 if (NULL == message) {
759 // Out of memory: can't create detailed error message
760 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
761 } else {
762 jio_snprintf(message, msglen, "%s%s", desc, className);
763 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
764 }
765 }
766
767 // Step 6
768 this_oop->set_init_state(being_initialized);
769 this_oop->set_init_thread(self);
770 }
771
772 // Step 7
773 Klass* super_klass = this_oop->super();
774 if (super_klass != NULL && !this_oop->is_interface() && super_klass->should_be_initialized()) {
775 super_klass->initialize(THREAD);
776
777 if (HAS_PENDING_EXCEPTION) {
778 Handle e(THREAD, PENDING_EXCEPTION);
779 CLEAR_PENDING_EXCEPTION;
780 {
781 EXCEPTION_MARK;
782 this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
783 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, superclass initialization error is thrown below
784 }
785 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
786 THROW_OOP(e());
787 }
788 }
789
790 if (this_oop->has_default_methods()) {
791 // Step 7.5: initialize any interfaces which have default methods
792 for (int i = 0; i < this_oop->local_interfaces()->length(); ++i) {
793 Klass* iface = this_oop->local_interfaces()->at(i);
794 InstanceKlass* ik = InstanceKlass::cast(iface);
795 if (ik->has_default_methods() && ik->should_be_initialized()) {
796 ik->initialize(THREAD);
797
798 if (HAS_PENDING_EXCEPTION) {
799 Handle e(THREAD, PENDING_EXCEPTION);
800 CLEAR_PENDING_EXCEPTION;
801 {
802 EXCEPTION_MARK;
803 // Locks object, set state, and notify all waiting threads
804 this_oop->set_initialization_state_and_notify(
805 initialization_error, THREAD);
806
807 // ignore any exception thrown, superclass initialization error is
808 // thrown below
809 CLEAR_PENDING_EXCEPTION;
810 }
811 DTRACE_CLASSINIT_PROBE_WAIT(
812 super__failed, InstanceKlass::cast(this_oop()), -1, wait);
813 THROW_OOP(e());
814 }
815 }
816 }
817 }
818
819 // Step 8
820 {
821 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
822 JavaThread* jt = (JavaThread*)THREAD;
823 DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
824 // Timer includes any side effects of class initialization (resolution,
825 // etc), but not recursive entry into call_class_initializer().
826 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
827 ClassLoader::perf_class_init_selftime(),
828 ClassLoader::perf_classes_inited(),
829 jt->get_thread_stat()->perf_recursion_counts_addr(),
830 jt->get_thread_stat()->perf_timers_addr(),
831 PerfClassTraceTime::CLASS_CLINIT);
832 this_oop->call_class_initializer(THREAD);
833 }
834
835 // Step 9
836 if (!HAS_PENDING_EXCEPTION) {
837 this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
838 { ResourceMark rm(THREAD);
839 debug_only(this_oop->vtable()->verify(tty, true);)
840 }
841 }
842 else {
843 // Step 10 and 11
844 Handle e(THREAD, PENDING_EXCEPTION);
845 CLEAR_PENDING_EXCEPTION;
846 {
847 EXCEPTION_MARK;
848 this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
849 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
850 }
851 DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
852 if (e->is_a(SystemDictionary::Error_klass())) {
853 THROW_OOP(e());
854 } else {
855 JavaCallArguments args(e);
856 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
857 vmSymbols::throwable_void_signature(),
858 &args);
859 }
860 }
861 DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
862 }
863
864
865 // Note: implementation moved to static method to expose the this pointer.
866 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
867 instanceKlassHandle kh(THREAD, this);
868 set_initialization_state_and_notify_impl(kh, state, CHECK);
869 }
870
871 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
872 volatile oop init_lock = this_oop->init_lock();
873 ObjectLocker ol(init_lock, THREAD);
874 this_oop->set_init_state(state);
875 ol.notify_all(CHECK);
876 }
877
878 // The embedded _implementor field can only record one implementor.
879 // When there are more than one implementors, the _implementor field
880 // is set to the interface Klass* itself. Following are the possible
881 // values for the _implementor field:
882 // NULL - no implementor
883 // implementor Klass* - one implementor
884 // self - more than one implementor
885 //
886 // The _implementor field only exists for interfaces.
887 void InstanceKlass::add_implementor(Klass* k) {
888 assert(Compile_lock->owned_by_self(), "");
889 assert(is_interface(), "not interface");
890 // Filter out my subinterfaces.
891 // (Note: Interfaces are never on the subklass list.)
892 if (InstanceKlass::cast(k)->is_interface()) return;
893
894 // Filter out subclasses whose supers already implement me.
895 // (Note: CHA must walk subclasses of direct implementors
896 // in order to locate indirect implementors.)
897 Klass* sk = InstanceKlass::cast(k)->super();
898 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
899 // We only need to check one immediate superclass, since the
900 // implements_interface query looks at transitive_interfaces.
901 // Any supers of the super have the same (or fewer) transitive_interfaces.
902 return;
903
904 Klass* ik = implementor();
905 if (ik == NULL) {
906 set_implementor(k);
907 } else if (ik != this) {
908 // There is already an implementor. Use itself as an indicator of
909 // more than one implementors.
910 set_implementor(this);
911 }
912
913 // The implementor also implements the transitive_interfaces
914 for (int index = 0; index < local_interfaces()->length(); index++) {
915 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
916 }
917 }
918
919 void InstanceKlass::init_implementor() {
920 if (is_interface()) {
921 set_implementor(NULL);
922 }
923 }
924
925
926 void InstanceKlass::process_interfaces(Thread *thread) {
927 // link this class into the implementors list of every interface it implements
928 Klass* this_as_klass_oop = this;
929 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
930 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
931 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
932 assert(interf->is_interface(), "expected interface");
933 interf->add_implementor(this_as_klass_oop);
934 }
935 }
936
937 bool InstanceKlass::can_be_primary_super_slow() const {
938 if (is_interface())
939 return false;
940 else
941 return Klass::can_be_primary_super_slow();
942 }
943
944 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
945 // The secondaries are the implemented interfaces.
946 InstanceKlass* ik = InstanceKlass::cast(this);
947 Array<Klass*>* interfaces = ik->transitive_interfaces();
948 int num_secondaries = num_extra_slots + interfaces->length();
949 if (num_secondaries == 0) {
950 // Must share this for correct bootstrapping!
951 set_secondary_supers(Universe::the_empty_klass_array());
952 return NULL;
953 } else if (num_extra_slots == 0) {
954 // The secondary super list is exactly the same as the transitive interfaces.
955 // Redefine classes has to be careful not to delete this!
956 set_secondary_supers(interfaces);
957 return NULL;
958 } else {
959 // Copy transitive interfaces to a temporary growable array to be constructed
960 // into the secondary super list with extra slots.
961 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
962 for (int i = 0; i < interfaces->length(); i++) {
963 secondaries->push(interfaces->at(i));
964 }
965 return secondaries;
966 }
967 }
968
969 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
970 if (k->is_interface()) {
971 return implements_interface(k);
972 } else {
973 return Klass::compute_is_subtype_of(k);
974 }
975 }
976
977 bool InstanceKlass::implements_interface(Klass* k) const {
978 if (this == k) return true;
979 assert(k->is_interface(), "should be an interface class");
980 for (int i = 0; i < transitive_interfaces()->length(); i++) {
981 if (transitive_interfaces()->at(i) == k) {
982 return true;
983 }
984 }
985 return false;
986 }
987
988 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
989 if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
990 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
991 report_java_out_of_memory("Requested array size exceeds VM limit");
992 JvmtiExport::post_array_size_exhausted();
993 THROW_OOP_0(Universe::out_of_memory_error_array_size());
994 }
995 int size = objArrayOopDesc::object_size(length);
996 Klass* ak = array_klass(n, CHECK_NULL);
997 KlassHandle h_ak (THREAD, ak);
998 objArrayOop o =
999 (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
1000 return o;
1001 }
1002
1003 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1004 if (TraceFinalizerRegistration) {
1005 tty->print("Registered ");
1006 i->print_value_on(tty);
1007 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
1008 }
1009 instanceHandle h_i(THREAD, i);
1010 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1011 JavaValue result(T_VOID);
1012 JavaCallArguments args(h_i);
1013 methodHandle mh (THREAD, Universe::finalizer_register_method());
1014 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1015 return h_i();
1016 }
1017
1018 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1019 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1020 int size = size_helper(); // Query before forming handle.
1021
1022 KlassHandle h_k(THREAD, this);
1023
1024 instanceOop i;
1025
1026 i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
1027 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1028 i = register_finalizer(i, CHECK_NULL);
1029 }
1030 return i;
1031 }
1032
1033 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1034 if (is_interface() || is_abstract()) {
1035 ResourceMark rm(THREAD);
1036 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1037 : vmSymbols::java_lang_InstantiationException(), external_name());
1038 }
1039 if (this == SystemDictionary::Class_klass()) {
1040 ResourceMark rm(THREAD);
1041 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1042 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1043 }
1044 }
1045
1046 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1047 instanceKlassHandle this_oop(THREAD, this);
1048 return array_klass_impl(this_oop, or_null, n, THREAD);
1049 }
1050
1051 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
1052 if (this_oop->array_klasses() == NULL) {
1053 if (or_null) return NULL;
1054
1055 ResourceMark rm;
1056 JavaThread *jt = (JavaThread *)THREAD;
1057 {
1058 // Atomic creation of array_klasses
1059 MutexLocker mc(Compile_lock, THREAD); // for vtables
1060 MutexLocker ma(MultiArray_lock, THREAD);
1061
1062 // Check if update has already taken place
1063 if (this_oop->array_klasses() == NULL) {
1064 Klass* k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
1065 this_oop->set_array_klasses(k);
1066 }
1067 }
1068 }
1069 // _this will always be set at this point
1070 ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
1071 if (or_null) {
1072 return oak->array_klass_or_null(n);
1073 }
1074 return oak->array_klass(n, CHECK_NULL);
1075 }
1076
1077 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1078 return array_klass_impl(or_null, 1, THREAD);
1079 }
1080
1081 void InstanceKlass::call_class_initializer(TRAPS) {
1082 instanceKlassHandle ik (THREAD, this);
1083 call_class_initializer_impl(ik, THREAD);
1084 }
1085
1086 static int call_class_initializer_impl_counter = 0; // for debugging
1087
1088 Method* InstanceKlass::class_initializer() {
1089 Method* clinit = find_method(
1090 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1091 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1092 return clinit;
1093 }
1094 return NULL;
1095 }
1096
1097 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
1098 if (ReplayCompiles &&
1099 (ReplaySuppressInitializers == 1 ||
1100 ReplaySuppressInitializers >= 2 && this_oop->class_loader() != NULL)) {
1101 // Hide the existence of the initializer for the purpose of replaying the compile
1102 return;
1103 }
1104
1105 methodHandle h_method(THREAD, this_oop->class_initializer());
1106 assert(!this_oop->is_initialized(), "we cannot initialize twice");
1107 if (TraceClassInitialization) {
1108 tty->print("%d Initializing ", call_class_initializer_impl_counter++);
1109 this_oop->name()->print_value();
1110 tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
1111 }
1112 if (h_method() != NULL) {
1113 JavaCallArguments args; // No arguments
1114 JavaValue result(T_VOID);
1115 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1116 }
1117 }
1118
1119
1120 void InstanceKlass::mask_for(methodHandle method, int bci,
1121 InterpreterOopMap* entry_for) {
1122 // Dirty read, then double-check under a lock.
1123 if (_oop_map_cache == NULL) {
1124 // Otherwise, allocate a new one.
1125 MutexLocker x(OopMapCacheAlloc_lock);
1126 // First time use. Allocate a cache in C heap
1127 if (_oop_map_cache == NULL) {
1128 _oop_map_cache = new OopMapCache();
1129 }
1130 }
1131 // _oop_map_cache is constant after init; lookup below does is own locking.
1132 _oop_map_cache->lookup(method, bci, entry_for);
1133 }
1134
1135
1136 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1137 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1138 Symbol* f_name = fs.name();
1139 Symbol* f_sig = fs.signature();
1140 if (f_name == name && f_sig == sig) {
1141 fd->initialize(const_cast<InstanceKlass*>(this), fs.index());
1142 return true;
1143 }
1144 }
1145 return false;
1146 }
1147
1148
1149 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1150 const int n = local_interfaces()->length();
1151 for (int i = 0; i < n; i++) {
1152 Klass* intf1 = local_interfaces()->at(i);
1153 assert(intf1->is_interface(), "just checking type");
1154 // search for field in current interface
1155 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1156 assert(fd->is_static(), "interface field must be static");
1157 return intf1;
1158 }
1159 // search for field in direct superinterfaces
1160 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1161 if (intf2 != NULL) return intf2;
1162 }
1163 // otherwise field lookup fails
1164 return NULL;
1165 }
1166
1167
1168 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1169 // search order according to newest JVM spec (5.4.3.2, p.167).
1170 // 1) search for field in current klass
1171 if (find_local_field(name, sig, fd)) {
1172 return const_cast<InstanceKlass*>(this);
1173 }
1174 // 2) search for field recursively in direct superinterfaces
1175 { Klass* intf = find_interface_field(name, sig, fd);
1176 if (intf != NULL) return intf;
1177 }
1178 // 3) apply field lookup recursively if superclass exists
1179 { Klass* supr = super();
1180 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1181 }
1182 // 4) otherwise field lookup fails
1183 return NULL;
1184 }
1185
1186
1187 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1188 // search order according to newest JVM spec (5.4.3.2, p.167).
1189 // 1) search for field in current klass
1190 if (find_local_field(name, sig, fd)) {
1191 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1192 }
1193 // 2) search for field recursively in direct superinterfaces
1194 if (is_static) {
1195 Klass* intf = find_interface_field(name, sig, fd);
1196 if (intf != NULL) return intf;
1197 }
1198 // 3) apply field lookup recursively if superclass exists
1199 { Klass* supr = super();
1200 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1201 }
1202 // 4) otherwise field lookup fails
1203 return NULL;
1204 }
1205
1206
1207 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1208 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1209 if (fs.offset() == offset) {
1210 fd->initialize(const_cast<InstanceKlass*>(this), fs.index());
1211 if (fd->is_static() == is_static) return true;
1212 }
1213 }
1214 return false;
1215 }
1216
1217
1218 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1219 Klass* klass = const_cast<InstanceKlass*>(this);
1220 while (klass != NULL) {
1221 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1222 return true;
1223 }
1224 klass = klass->super();
1225 }
1226 return false;
1227 }
1228
1229
1230 void InstanceKlass::methods_do(void f(Method* method)) {
1231 int len = methods()->length();
1232 for (int index = 0; index < len; index++) {
1233 Method* m = methods()->at(index);
1234 assert(m->is_method(), "must be method");
1235 f(m);
1236 }
1237 }
1238
1239
1240 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1241 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1242 if (fs.access_flags().is_static()) {
1243 fieldDescriptor fd;
1244 fd.initialize(this, fs.index());
1245 cl->do_field(&fd);
1246 }
1247 }
1248 }
1249
1250
1251 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
1252 instanceKlassHandle h_this(THREAD, this);
1253 do_local_static_fields_impl(h_this, f, CHECK);
1254 }
1255
1256
1257 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
1258 for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
1259 if (fs.access_flags().is_static()) {
1260 fieldDescriptor fd;
1261 fd.initialize(this_oop(), fs.index());
1262 f(&fd, CHECK);
1263 }
1264 }
1265 }
1266
1267
1268 static int compare_fields_by_offset(int* a, int* b) {
1269 return a[0] - b[0];
1270 }
1271
1272 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1273 InstanceKlass* super = superklass();
1274 if (super != NULL) {
1275 super->do_nonstatic_fields(cl);
1276 }
1277 fieldDescriptor fd;
1278 int length = java_fields_count();
1279 // In DebugInfo nonstatic fields are sorted by offset.
1280 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1281 int j = 0;
1282 for (int i = 0; i < length; i += 1) {
1283 fd.initialize(this, i);
1284 if (!fd.is_static()) {
1285 fields_sorted[j + 0] = fd.offset();
1286 fields_sorted[j + 1] = i;
1287 j += 2;
1288 }
1289 }
1290 if (j > 0) {
1291 length = j;
1292 // _sort_Fn is defined in growableArray.hpp.
1293 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1294 for (int i = 0; i < length; i += 2) {
1295 fd.initialize(this, fields_sorted[i + 1]);
1296 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1297 cl->do_field(&fd);
1298 }
1299 }
1300 FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
1301 }
1302
1303
1304 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1305 if (array_klasses() != NULL)
1306 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1307 }
1308
1309 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1310 if (array_klasses() != NULL)
1311 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1312 }
1313
1314
1315 void InstanceKlass::with_array_klasses_do(void f(Klass* k)) {
1316 f(this);
1317 array_klasses_do(f);
1318 }
1319
1320 #ifdef ASSERT
1321 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
1322 int len = methods->length();
1323 for (int index = 0; index < len; index++) {
1324 Method* m = methods->at(index);
1325 assert(m->is_method(), "must be method");
1326 if (m->signature() == signature && m->name() == name) {
1327 return index;
1328 }
1329 }
1330 return -1;
1331 }
1332 #endif
1333
1334 static int binary_search(Array<Method*>* methods, Symbol* name) {
1335 int len = methods->length();
1336 // methods are sorted, so do binary search
1337 int l = 0;
1338 int h = len - 1;
1339 while (l <= h) {
1340 int mid = (l + h) >> 1;
1341 Method* m = methods->at(mid);
1342 assert(m->is_method(), "must be method");
1343 int res = m->name()->fast_compare(name);
1344 if (res == 0) {
1345 return mid;
1346 } else if (res < 0) {
1347 l = mid + 1;
1348 } else {
1349 h = mid - 1;
1350 }
1351 }
1352 return -1;
1353 }
1354
1355 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
1356 return InstanceKlass::find_method(methods(), name, signature);
1357 }
1358
1359 Method* InstanceKlass::find_method(
1360 Array<Method*>* methods, Symbol* name, Symbol* signature) {
1361 int hit = binary_search(methods, name);
1362 if (hit != -1) {
1363 Method* m = methods->at(hit);
1364 // Do linear search to find matching signature. First, quick check
1365 // for common case
1366 if (m->signature() == signature) return m;
1367 // search downwards through overloaded methods
1368 int i;
1369 for (i = hit - 1; i >= 0; --i) {
1370 Method* m = methods->at(i);
1371 assert(m->is_method(), "must be method");
1372 if (m->name() != name) break;
1373 if (m->signature() == signature) return m;
1374 }
1375 // search upwards
1376 for (i = hit + 1; i < methods->length(); ++i) {
1377 Method* m = methods->at(i);
1378 assert(m->is_method(), "must be method");
1379 if (m->name() != name) break;
1380 if (m->signature() == signature) return m;
1381 }
1382 // not found
1383 #ifdef ASSERT
1384 int index = linear_search(methods, name, signature);
1385 assert(index == -1, err_msg("binary search should have found entry %d", index));
1386 #endif
1387 }
1388 return NULL;
1389 }
1390
1391 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
1392 return find_method_by_name(methods(), name, end);
1393 }
1394
1395 int InstanceKlass::find_method_by_name(
1396 Array<Method*>* methods, Symbol* name, int* end_ptr) {
1397 assert(end_ptr != NULL, "just checking");
1398 int start = binary_search(methods, name);
1399 int end = start + 1;
1400 if (start != -1) {
1401 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1402 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1403 *end_ptr = end;
1404 return start;
1405 }
1406 return -1;
1407 }
1408
1409 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
1410 Klass* klass = const_cast<InstanceKlass*>(this);
1411 while (klass != NULL) {
1412 Method* method = InstanceKlass::cast(klass)->find_method(name, signature);
1413 if (method != NULL) return method;
1414 klass = InstanceKlass::cast(klass)->super();
1415 }
1416 return NULL;
1417 }
1418
1419 // lookup a method in all the interfaces that this class implements
1420 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1421 Symbol* signature) const {
1422 Array<Klass*>* all_ifs = transitive_interfaces();
1423 int num_ifs = all_ifs->length();
1424 InstanceKlass *ik = NULL;
1425 for (int i = 0; i < num_ifs; i++) {
1426 ik = InstanceKlass::cast(all_ifs->at(i));
1427 Method* m = ik->lookup_method(name, signature);
1428 if (m != NULL) {
1429 return m;
1430 }
1431 }
1432 return NULL;
1433 }
1434
1435 /* jni_id_for_impl for jfieldIds only */
1436 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
1437 MutexLocker ml(JfieldIdCreation_lock);
1438 // Retry lookup after we got the lock
1439 JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
1440 if (probe == NULL) {
1441 // Slow case, allocate new static field identifier
1442 probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
1443 this_oop->set_jni_ids(probe);
1444 }
1445 return probe;
1446 }
1447
1448
1449 /* jni_id_for for jfieldIds only */
1450 JNIid* InstanceKlass::jni_id_for(int offset) {
1451 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1452 if (probe == NULL) {
1453 probe = jni_id_for_impl(this, offset);
1454 }
1455 return probe;
1456 }
1457
1458 u2 InstanceKlass::enclosing_method_data(int offset) {
1459 Array<jushort>* inner_class_list = inner_classes();
1460 if (inner_class_list == NULL) {
1461 return 0;
1462 }
1463 int length = inner_class_list->length();
1464 if (length % inner_class_next_offset == 0) {
1465 return 0;
1466 } else {
1467 int index = length - enclosing_method_attribute_size;
1468 assert(offset < enclosing_method_attribute_size, "invalid offset");
1469 return inner_class_list->at(index + offset);
1470 }
1471 }
1472
1473 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1474 u2 method_index) {
1475 Array<jushort>* inner_class_list = inner_classes();
1476 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1477 int length = inner_class_list->length();
1478 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1479 int index = length - enclosing_method_attribute_size;
1480 inner_class_list->at_put(
1481 index + enclosing_method_class_index_offset, class_index);
1482 inner_class_list->at_put(
1483 index + enclosing_method_method_index_offset, method_index);
1484 }
1485 }
1486
1487 // Lookup or create a jmethodID.
1488 // This code is called by the VMThread and JavaThreads so the
1489 // locking has to be done very carefully to avoid deadlocks
1490 // and/or other cache consistency problems.
1491 //
1492 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1493 size_t idnum = (size_t)method_h->method_idnum();
1494 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1495 size_t length = 0;
1496 jmethodID id = NULL;
1497
1498 // We use a double-check locking idiom here because this cache is
1499 // performance sensitive. In the normal system, this cache only
1500 // transitions from NULL to non-NULL which is safe because we use
1501 // release_set_methods_jmethod_ids() to advertise the new cache.
1502 // A partially constructed cache should never be seen by a racing
1503 // thread. We also use release_store_ptr() to save a new jmethodID
1504 // in the cache so a partially constructed jmethodID should never be
1505 // seen either. Cache reads of existing jmethodIDs proceed without a
1506 // lock, but cache writes of a new jmethodID requires uniqueness and
1507 // creation of the cache itself requires no leaks so a lock is
1508 // generally acquired in those two cases.
1509 //
1510 // If the RedefineClasses() API has been used, then this cache can
1511 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1512 // Cache creation requires no leaks and we require safety between all
1513 // cache accesses and freeing of the old cache so a lock is generally
1514 // acquired when the RedefineClasses() API has been used.
1515
1516 if (jmeths != NULL) {
1517 // the cache already exists
1518 if (!ik_h->idnum_can_increment()) {
1519 // the cache can't grow so we can just get the current values
1520 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1521 } else {
1522 // cache can grow so we have to be more careful
1523 if (Threads::number_of_threads() == 0 ||
1524 SafepointSynchronize::is_at_safepoint()) {
1525 // we're single threaded or at a safepoint - no locking needed
1526 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1527 } else {
1528 MutexLocker ml(JmethodIdCreation_lock);
1529 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1530 }
1531 }
1532 }
1533 // implied else:
1534 // we need to allocate a cache so default length and id values are good
1535
1536 if (jmeths == NULL || // no cache yet
1537 length <= idnum || // cache is too short
1538 id == NULL) { // cache doesn't contain entry
1539
1540 // This function can be called by the VMThread so we have to do all
1541 // things that might block on a safepoint before grabbing the lock.
1542 // Otherwise, we can deadlock with the VMThread or have a cache
1543 // consistency issue. These vars keep track of what we might have
1544 // to free after the lock is dropped.
1545 jmethodID to_dealloc_id = NULL;
1546 jmethodID* to_dealloc_jmeths = NULL;
1547
1548 // may not allocate new_jmeths or use it if we allocate it
1549 jmethodID* new_jmeths = NULL;
1550 if (length <= idnum) {
1551 // allocate a new cache that might be used
1552 size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1553 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1554 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1555 // cache size is stored in element[0], other elements offset by one
1556 new_jmeths[0] = (jmethodID)size;
1557 }
1558
1559 // allocate a new jmethodID that might be used
1560 jmethodID new_id = NULL;
1561 if (method_h->is_old() && !method_h->is_obsolete()) {
1562 // The method passed in is old (but not obsolete), we need to use the current version
1563 Method* current_method = ik_h->method_with_idnum((int)idnum);
1564 assert(current_method != NULL, "old and but not obsolete, so should exist");
1565 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
1566 } else {
1567 // It is the current version of the method or an obsolete method,
1568 // use the version passed in
1569 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
1570 }
1571
1572 if (Threads::number_of_threads() == 0 ||
1573 SafepointSynchronize::is_at_safepoint()) {
1574 // we're single threaded or at a safepoint - no locking needed
1575 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1576 &to_dealloc_id, &to_dealloc_jmeths);
1577 } else {
1578 MutexLocker ml(JmethodIdCreation_lock);
1579 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1580 &to_dealloc_id, &to_dealloc_jmeths);
1581 }
1582
1583 // The lock has been dropped so we can free resources.
1584 // Free up either the old cache or the new cache if we allocated one.
1585 if (to_dealloc_jmeths != NULL) {
1586 FreeHeap(to_dealloc_jmeths);
1587 }
1588 // free up the new ID since it wasn't needed
1589 if (to_dealloc_id != NULL) {
1590 Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
1591 }
1592 }
1593 return id;
1594 }
1595
1596
1597 // Common code to fetch the jmethodID from the cache or update the
1598 // cache with the new jmethodID. This function should never do anything
1599 // that causes the caller to go to a safepoint or we can deadlock with
1600 // the VMThread or have cache consistency issues.
1601 //
1602 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1603 instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1604 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1605 jmethodID** to_dealloc_jmeths_p) {
1606 assert(new_id != NULL, "sanity check");
1607 assert(to_dealloc_id_p != NULL, "sanity check");
1608 assert(to_dealloc_jmeths_p != NULL, "sanity check");
1609 assert(Threads::number_of_threads() == 0 ||
1610 SafepointSynchronize::is_at_safepoint() ||
1611 JmethodIdCreation_lock->owned_by_self(), "sanity check");
1612
1613 // reacquire the cache - we are locked, single threaded or at a safepoint
1614 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1615 jmethodID id = NULL;
1616 size_t length = 0;
1617
1618 if (jmeths == NULL || // no cache yet
1619 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
1620 if (jmeths != NULL) {
1621 // copy any existing entries from the old cache
1622 for (size_t index = 0; index < length; index++) {
1623 new_jmeths[index+1] = jmeths[index+1];
1624 }
1625 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
1626 }
1627 ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1628 } else {
1629 // fetch jmethodID (if any) from the existing cache
1630 id = jmeths[idnum+1];
1631 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
1632 }
1633 if (id == NULL) {
1634 // No matching jmethodID in the existing cache or we have a new
1635 // cache or we just grew the cache. This cache write is done here
1636 // by the first thread to win the foot race because a jmethodID
1637 // needs to be unique once it is generally available.
1638 id = new_id;
1639
1640 // The jmethodID cache can be read while unlocked so we have to
1641 // make sure the new jmethodID is complete before installing it
1642 // in the cache.
1643 OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1644 } else {
1645 *to_dealloc_id_p = new_id; // save new id for later delete
1646 }
1647 return id;
1648 }
1649
1650
1651 // Common code to get the jmethodID cache length and the jmethodID
1652 // value at index idnum if there is one.
1653 //
1654 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1655 size_t idnum, size_t *length_p, jmethodID* id_p) {
1656 assert(cache != NULL, "sanity check");
1657 assert(length_p != NULL, "sanity check");
1658 assert(id_p != NULL, "sanity check");
1659
1660 // cache size is stored in element[0], other elements offset by one
1661 *length_p = (size_t)cache[0];
1662 if (*length_p <= idnum) { // cache is too short
1663 *id_p = NULL;
1664 } else {
1665 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
1666 }
1667 }
1668
1669
1670 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
1671 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1672 size_t idnum = (size_t)method->method_idnum();
1673 jmethodID* jmeths = methods_jmethod_ids_acquire();
1674 size_t length; // length assigned as debugging crumb
1675 jmethodID id = NULL;
1676 if (jmeths != NULL && // If there is a cache
1677 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
1678 id = jmeths[idnum+1]; // Look up the id (may be NULL)
1679 }
1680 return id;
1681 }
1682
1683
1684 // Cache an itable index
1685 void InstanceKlass::set_cached_itable_index(size_t idnum, int index) {
1686 int* indices = methods_cached_itable_indices_acquire();
1687 int* to_dealloc_indices = NULL;
1688
1689 // We use a double-check locking idiom here because this cache is
1690 // performance sensitive. In the normal system, this cache only
1691 // transitions from NULL to non-NULL which is safe because we use
1692 // release_set_methods_cached_itable_indices() to advertise the
1693 // new cache. A partially constructed cache should never be seen
1694 // by a racing thread. Cache reads and writes proceed without a
1695 // lock, but creation of the cache itself requires no leaks so a
1696 // lock is generally acquired in that case.
1697 //
1698 // If the RedefineClasses() API has been used, then this cache can
1699 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1700 // Cache creation requires no leaks and we require safety between all
1701 // cache accesses and freeing of the old cache so a lock is generally
1702 // acquired when the RedefineClasses() API has been used.
1703
1704 if (indices == NULL || idnum_can_increment()) {
1705 // we need a cache or the cache can grow
1706 MutexLocker ml(JNICachedItableIndex_lock);
1707 // reacquire the cache to see if another thread already did the work
1708 indices = methods_cached_itable_indices_acquire();
1709 size_t length = 0;
1710 // cache size is stored in element[0], other elements offset by one
1711 if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
1712 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1713 int* new_indices = NEW_C_HEAP_ARRAY(int, size+1, mtClass);
1714 new_indices[0] = (int)size;
1715 // copy any existing entries
1716 size_t i;
1717 for (i = 0; i < length; i++) {
1718 new_indices[i+1] = indices[i+1];
1719 }
1720 // Set all the rest to -1
1721 for (i = length; i < size; i++) {
1722 new_indices[i+1] = -1;
1723 }
1724 if (indices != NULL) {
1725 // We have an old cache to delete so save it for after we
1726 // drop the lock.
1727 to_dealloc_indices = indices;
1728 }
1729 release_set_methods_cached_itable_indices(indices = new_indices);
1730 }
1731
1732 if (idnum_can_increment()) {
1733 // this cache can grow so we have to write to it safely
1734 indices[idnum+1] = index;
1735 }
1736 } else {
1737 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
1738 }
1739
1740 if (!idnum_can_increment()) {
1741 // The cache cannot grow and this JNI itable index value does not
1742 // have to be unique like a jmethodID. If there is a race to set it,
1743 // it doesn't matter.
1744 indices[idnum+1] = index;
1745 }
1746
1747 if (to_dealloc_indices != NULL) {
1748 // we allocated a new cache so free the old one
1749 FreeHeap(to_dealloc_indices);
1750 }
1751 }
1752
1753
1754 // Retrieve a cached itable index
1755 int InstanceKlass::cached_itable_index(size_t idnum) {
1756 int* indices = methods_cached_itable_indices_acquire();
1757 if (indices != NULL && ((size_t)indices[0]) > idnum) {
1758 // indices exist and are long enough, retrieve possible cached
1759 return indices[idnum+1];
1760 }
1761 return -1;
1762 }
1763
1764
1765 //
1766 // Walk the list of dependent nmethods searching for nmethods which
1767 // are dependent on the changes that were passed in and mark them for
1768 // deoptimization. Returns the number of nmethods found.
1769 //
1770 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
1771 assert_locked_or_safepoint(CodeCache_lock);
1772 int found = 0;
1773 nmethodBucket* b = _dependencies;
1774 while (b != NULL) {
1775 nmethod* nm = b->get_nmethod();
1776 // since dependencies aren't removed until an nmethod becomes a zombie,
1777 // the dependency list may contain nmethods which aren't alive.
1778 if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1779 if (TraceDependencies) {
1780 ResourceMark rm;
1781 tty->print_cr("Marked for deoptimization");
1782 tty->print_cr(" context = %s", this->external_name());
1783 changes.print();
1784 nm->print();
1785 nm->print_dependencies();
1786 }
1787 nm->mark_for_deoptimization();
1788 found++;
1789 }
1790 b = b->next();
1791 }
1792 return found;
1793 }
1794
1795
1796 //
1797 // Add an nmethodBucket to the list of dependencies for this nmethod.
1798 // It's possible that an nmethod has multiple dependencies on this klass
1799 // so a count is kept for each bucket to guarantee that creation and
1800 // deletion of dependencies is consistent.
1801 //
1802 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1803 assert_locked_or_safepoint(CodeCache_lock);
1804 nmethodBucket* b = _dependencies;
1805 nmethodBucket* last = NULL;
1806 while (b != NULL) {
1807 if (nm == b->get_nmethod()) {
1808 b->increment();
1809 return;
1810 }
1811 b = b->next();
1812 }
1813 _dependencies = new nmethodBucket(nm, _dependencies);
1814 }
1815
1816
1817 //
1818 // Decrement count of the nmethod in the dependency list and remove
1819 // the bucket competely when the count goes to 0. This method must
1820 // find a corresponding bucket otherwise there's a bug in the
1821 // recording of dependecies.
1822 //
1823 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
1824 assert_locked_or_safepoint(CodeCache_lock);
1825 nmethodBucket* b = _dependencies;
1826 nmethodBucket* last = NULL;
1827 while (b != NULL) {
1828 if (nm == b->get_nmethod()) {
1829 if (b->decrement() == 0) {
1830 if (last == NULL) {
1831 _dependencies = b->next();
1832 } else {
1833 last->set_next(b->next());
1834 }
1835 delete b;
1836 }
1837 return;
1838 }
1839 last = b;
1840 b = b->next();
1841 }
1842 #ifdef ASSERT
1843 tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1844 nm->print();
1845 #endif // ASSERT
1846 ShouldNotReachHere();
1847 }
1848
1849
1850 #ifndef PRODUCT
1851 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1852 nmethodBucket* b = _dependencies;
1853 int idx = 0;
1854 while (b != NULL) {
1855 nmethod* nm = b->get_nmethod();
1856 tty->print("[%d] count=%d { ", idx++, b->count());
1857 if (!verbose) {
1858 nm->print_on(tty, "nmethod");
1859 tty->print_cr(" } ");
1860 } else {
1861 nm->print();
1862 nm->print_dependencies();
1863 tty->print_cr("--- } ");
1864 }
1865 b = b->next();
1866 }
1867 }
1868
1869
1870 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1871 nmethodBucket* b = _dependencies;
1872 while (b != NULL) {
1873 if (nm == b->get_nmethod()) {
1874 return true;
1875 }
1876 b = b->next();
1877 }
1878 return false;
1879 }
1880 #endif //PRODUCT
1881
1882
1883 // Garbage collection
1884
1885 void InstanceKlass::oops_do(OopClosure* cl) {
1886 Klass::oops_do(cl);
1887
1888 cl->do_oop(adr_protection_domain());
1889 cl->do_oop(adr_signers());
1890 cl->do_oop(adr_per_class_lock());
1891
1892 // Don't walk the arrays since they are walked from the ClassLoaderData objects.
1893 }
1894
1895 #ifdef ASSERT
1896 template <class T> void assert_is_in(T *p) {
1897 T heap_oop = oopDesc::load_heap_oop(p);
1898 if (!oopDesc::is_null(heap_oop)) {
1899 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1900 assert(Universe::heap()->is_in(o), "should be in heap");
1901 }
1902 }
1903 template <class T> void assert_is_in_closed_subset(T *p) {
1904 T heap_oop = oopDesc::load_heap_oop(p);
1905 if (!oopDesc::is_null(heap_oop)) {
1906 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1907 assert(Universe::heap()->is_in_closed_subset(o),
1908 err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
1909 }
1910 }
1911 template <class T> void assert_is_in_reserved(T *p) {
1912 T heap_oop = oopDesc::load_heap_oop(p);
1913 if (!oopDesc::is_null(heap_oop)) {
1914 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1915 assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
1916 }
1917 }
1918 template <class T> void assert_nothing(T *p) {}
1919
1920 #else
1921 template <class T> void assert_is_in(T *p) {}
1922 template <class T> void assert_is_in_closed_subset(T *p) {}
1923 template <class T> void assert_is_in_reserved(T *p) {}
1924 template <class T> void assert_nothing(T *p) {}
1925 #endif // ASSERT
1926
1927 //
1928 // Macros that iterate over areas of oops which are specialized on type of
1929 // oop pointer either narrow or wide, depending on UseCompressedOops
1930 //
1931 // Parameters are:
1932 // T - type of oop to point to (either oop or narrowOop)
1933 // start_p - starting pointer for region to iterate over
1934 // count - number of oops or narrowOops to iterate over
1935 // do_oop - action to perform on each oop (it's arbitrary C code which
1936 // makes it more efficient to put in a macro rather than making
1937 // it a template function)
1938 // assert_fn - assert function which is template function because performance
1939 // doesn't matter when enabled.
1940 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
1941 T, start_p, count, do_oop, \
1942 assert_fn) \
1943 { \
1944 T* p = (T*)(start_p); \
1945 T* const end = p + (count); \
1946 while (p < end) { \
1947 (assert_fn)(p); \
1948 do_oop; \
1949 ++p; \
1950 } \
1951 }
1952
1953 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
1954 T, start_p, count, do_oop, \
1955 assert_fn) \
1956 { \
1957 T* const start = (T*)(start_p); \
1958 T* p = start + (count); \
1959 while (start < p) { \
1960 --p; \
1961 (assert_fn)(p); \
1962 do_oop; \
1963 } \
1964 }
1965
1966 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
1967 T, start_p, count, low, high, \
1968 do_oop, assert_fn) \
1969 { \
1970 T* const l = (T*)(low); \
1971 T* const h = (T*)(high); \
1972 assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
1973 mask_bits((intptr_t)h, sizeof(T)-1) == 0, \
1974 "bounded region must be properly aligned"); \
1975 T* p = (T*)(start_p); \
1976 T* end = p + (count); \
1977 if (p < l) p = l; \
1978 if (end > h) end = h; \
1979 while (p < end) { \
1980 (assert_fn)(p); \
1981 do_oop; \
1982 ++p; \
1983 } \
1984 }
1985
1986
1987 // The following macros call specialized macros, passing either oop or
1988 // narrowOop as the specialization type. These test the UseCompressedOops
1989 // flag.
1990 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \
1991 { \
1992 /* Compute oopmap block range. The common case \
1993 is nonstatic_oop_map_size == 1. */ \
1994 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1995 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1996 if (UseCompressedOops) { \
1997 while (map < end_map) { \
1998 InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
1999 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
2000 do_oop, assert_fn) \
2001 ++map; \
2002 } \
2003 } else { \
2004 while (map < end_map) { \
2005 InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
2006 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2007 do_oop, assert_fn) \
2008 ++map; \
2009 } \
2010 } \
2011 }
2012
2013 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \
2014 { \
2015 OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \
2016 OopMapBlock* map = start_map + nonstatic_oop_map_count(); \
2017 if (UseCompressedOops) { \
2018 while (start_map < map) { \
2019 --map; \
2020 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \
2021 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
2022 do_oop, assert_fn) \
2023 } \
2024 } else { \
2025 while (start_map < map) { \
2026 --map; \
2027 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \
2028 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2029 do_oop, assert_fn) \
2030 } \
2031 } \
2032 }
2033
2034 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \
2035 assert_fn) \
2036 { \
2037 /* Compute oopmap block range. The common case is \
2038 nonstatic_oop_map_size == 1, so we accept the \
2039 usually non-existent extra overhead of examining \
2040 all the maps. */ \
2041 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
2042 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
2043 if (UseCompressedOops) { \
2044 while (map < end_map) { \
2045 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
2046 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
2047 low, high, \
2048 do_oop, assert_fn) \
2049 ++map; \
2050 } \
2051 } else { \
2052 while (map < end_map) { \
2053 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
2054 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2055 low, high, \
2056 do_oop, assert_fn) \
2057 ++map; \
2058 } \
2059 } \
2060 }
2061
2062 void InstanceKlass::oop_follow_contents(oop obj) {
2063 assert(obj != NULL, "can't follow the content of NULL object");
2064 MarkSweep::follow_klass(obj->klass());
2065 InstanceKlass_OOP_MAP_ITERATE( \
2066 obj, \
2067 MarkSweep::mark_and_push(p), \
2068 assert_is_in_closed_subset)
2069 }
2070
2071 #if INCLUDE_ALL_GCS
2072 void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
2073 oop obj) {
2074 assert(obj != NULL, "can't follow the content of NULL object");
2075 PSParallelCompact::follow_klass(cm, obj->klass());
2076 // Only mark the header and let the scan of the meta-data mark
2077 // everything else.
2078 InstanceKlass_OOP_MAP_ITERATE( \
2079 obj, \
2080 PSParallelCompact::mark_and_push(cm, p), \
2081 assert_is_in)
2082 }
2083 #endif // INCLUDE_ALL_GCS
2084
2085 // closure's do_metadata() method dictates whether the given closure should be
2086 // applied to the klass ptr in the object header.
2087
2088 #define if_do_metadata_checked(closure, nv_suffix) \
2089 /* Make sure the non-virtual and the virtual versions match. */ \
2090 assert(closure->do_metadata##nv_suffix() == closure->do_metadata(), \
2091 "Inconsistency in do_metadata"); \
2092 if (closure->do_metadata##nv_suffix())
2093
2094 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
2095 \
2096 int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
2097 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2098 /* header */ \
2099 if_do_metadata_checked(closure, nv_suffix) { \
2100 closure->do_klass##nv_suffix(obj->klass()); \
2101 } \
2102 InstanceKlass_OOP_MAP_ITERATE( \
2103 obj, \
2104 SpecializationStats:: \
2105 record_do_oop_call##nv_suffix(SpecializationStats::ik); \
2106 (closure)->do_oop##nv_suffix(p), \
2107 assert_is_in_closed_subset) \
2108 return size_helper(); \
2109 }
2110
2111 #if INCLUDE_ALL_GCS
2112 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
2113 \
2114 int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \
2115 OopClosureType* closure) { \
2116 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
2117 /* header */ \
2118 if_do_metadata_checked(closure, nv_suffix) { \
2119 closure->do_klass##nv_suffix(obj->klass()); \
2120 } \
2121 /* instance variables */ \
2122 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2123 obj, \
2124 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
2125 (closure)->do_oop##nv_suffix(p), \
2126 assert_is_in_closed_subset) \
2127 return size_helper(); \
2128 }
2129 #endif // INCLUDE_ALL_GCS
2130
2131 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
2132 \
2133 int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \
2134 OopClosureType* closure, \
2135 MemRegion mr) { \
2136 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2137 if_do_metadata_checked(closure, nv_suffix) { \
2138 if (mr.contains(obj)) { \
2139 closure->do_klass##nv_suffix(obj->klass()); \
2140 } \
2141 } \
2142 InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
2143 obj, mr.start(), mr.end(), \
2144 (closure)->do_oop##nv_suffix(p), \
2145 assert_is_in_closed_subset) \
2146 return size_helper(); \
2147 }
2148
2149 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2150 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2151 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2152 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2153 #if INCLUDE_ALL_GCS
2154 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2155 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2156 #endif // INCLUDE_ALL_GCS
2157
2158 int InstanceKlass::oop_adjust_pointers(oop obj) {
2159 int size = size_helper();
2160 InstanceKlass_OOP_MAP_ITERATE( \
2161 obj, \
2162 MarkSweep::adjust_pointer(p), \
2163 assert_is_in)
2164 MarkSweep::adjust_klass(obj->klass());
2165 return size;
2166 }
2167
2168 #if INCLUDE_ALL_GCS
2169 void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
2170 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2171 obj, \
2172 if (PSScavenge::should_scavenge(p)) { \
2173 pm->claim_or_forward_depth(p); \
2174 }, \
2175 assert_nothing )
2176 }
2177
2178 int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
2179 int size = size_helper();
2180 InstanceKlass_OOP_MAP_ITERATE( \
2181 obj, \
2182 PSParallelCompact::adjust_pointer(p), \
2183 assert_is_in)
2184 obj->update_header(cm);
2185 return size;
2186 }
2187
2188 #endif // INCLUDE_ALL_GCS
2189
2190 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
2191 assert(is_loader_alive(is_alive), "this klass should be live");
2192 if (is_interface()) {
2193 if (ClassUnloading) {
2194 Klass* impl = implementor();
2195 if (impl != NULL) {
2196 if (!impl->is_loader_alive(is_alive)) {
2197 // remove this guy
2198 Klass** klass = adr_implementor();
2199 assert(klass != NULL, "null klass");
2200 if (klass != NULL) {
2201 *klass = NULL;
2202 }
2203 }
2204 }
2205 }
2206 }
2207 }
2208
2209 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
2210 #ifdef COMPILER2
2211 // Currently only used by C2.
2212 for (int m = 0; m < methods()->length(); m++) {
2213 MethodData* mdo = methods()->at(m)->method_data();
2214 if (mdo != NULL) {
2215 for (ProfileData* data = mdo->first_data();
2216 mdo->is_valid(data);
2217 data = mdo->next_data(data)) {
2218 data->clean_weak_klass_links(is_alive);
2219 }
2220 }
2221 }
2222 #else
2223 #ifdef ASSERT
2224 // Verify that we haven't started to use MDOs for C1.
2225 for (int m = 0; m < methods()->length(); m++) {
2226 MethodData* mdo = methods()->at(m)->method_data();
2227 assert(mdo == NULL, "Didn't expect C1 to use MDOs");
2228 }
2229 #endif // ASSERT
2230 #endif // !COMPILER2
2231 }
2232
2233
2234 static void remove_unshareable_in_class(Klass* k) {
2235 // remove klass's unshareable info
2236 k->remove_unshareable_info();
2237 }
2238
2239 void InstanceKlass::remove_unshareable_info() {
2240 Klass::remove_unshareable_info();
2241 // Unlink the class
2242 if (is_linked()) {
2243 unlink_class();
2244 }
2245 init_implementor();
2246
2247 constants()->remove_unshareable_info();
2248
2249 for (int i = 0; i < methods()->length(); i++) {
2250 Method* m = methods()->at(i);
2251 m->remove_unshareable_info();
2252 }
2253
2254 // Need to reinstate when reading back the class.
2255 set_per_class_lock(NULL);
2256
2257 // do array classes also.
2258 array_klasses_do(remove_unshareable_in_class);
2259 }
2260
2261 void restore_unshareable_in_class(Klass* k, TRAPS) {
2262 k->restore_unshareable_info(CHECK);
2263 }
2264
2265 void InstanceKlass::restore_unshareable_info(TRAPS) {
2266 Klass::restore_unshareable_info(CHECK);
2267 instanceKlassHandle ik(THREAD, this);
2268
2269 Array<Method*>* methods = ik->methods();
2270 int num_methods = methods->length();
2271 for (int index2 = 0; index2 < num_methods; ++index2) {
2272 methodHandle m(THREAD, methods->at(index2));
2273 m()->link_method(m, CHECK);
2274 // restore method's vtable by calling a virtual function
2275 m->restore_vtable();
2276 }
2277 if (JvmtiExport::has_redefined_a_class()) {
2278 // Reinitialize vtable because RedefineClasses may have changed some
2279 // entries in this vtable for super classes so the CDS vtable might
2280 // point to old or obsolete entries. RedefineClasses doesn't fix up
2281 // vtables in the shared system dictionary, only the main one.
2282 // It also redefines the itable too so fix that too.
2283 ResourceMark rm(THREAD);
2284 ik->vtable()->initialize_vtable(false, CHECK);
2285 ik->itable()->initialize_itable(false, CHECK);
2286 }
2287
2288 // Allocate a simple java object for a lock.
2289 // This needs to be a java object because during class initialization
2290 // it can be held across a java call.
2291 typeArrayOop r = oopFactory::new_typeArray(T_INT, 0, CHECK);
2292 Handle h(THREAD, (oop)r);
2293 ik->set_per_class_lock(h());
2294
2295 // restore constant pool resolved references
2296 ik->constants()->restore_unshareable_info(CHECK);
2297
2298 ik->array_klasses_do(restore_unshareable_in_class, CHECK);
2299 }
2300
2301 static void clear_all_breakpoints(Method* m) {
2302 m->clear_all_breakpoints();
2303 }
2304
2305 void InstanceKlass::release_C_heap_structures() {
2306 // Deallocate oop map cache
2307 if (_oop_map_cache != NULL) {
2308 delete _oop_map_cache;
2309 _oop_map_cache = NULL;
2310 }
2311
2312 // Deallocate JNI identifiers for jfieldIDs
2313 JNIid::deallocate(jni_ids());
2314 set_jni_ids(NULL);
2315
2316 jmethodID* jmeths = methods_jmethod_ids_acquire();
2317 if (jmeths != (jmethodID*)NULL) {
2318 release_set_methods_jmethod_ids(NULL);
2319 FreeHeap(jmeths);
2320 }
2321
2322 int* indices = methods_cached_itable_indices_acquire();
2323 if (indices != (int*)NULL) {
2324 release_set_methods_cached_itable_indices(NULL);
2325 FreeHeap(indices);
2326 }
2327
2328 // release dependencies
2329 nmethodBucket* b = _dependencies;
2330 _dependencies = NULL;
2331 while (b != NULL) {
2332 nmethodBucket* next = b->next();
2333 delete b;
2334 b = next;
2335 }
2336
2337 // Deallocate breakpoint records
2338 if (breakpoints() != 0x0) {
2339 methods_do(clear_all_breakpoints);
2340 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2341 }
2342
2343 // deallocate information about previous versions
2344 if (_previous_versions != NULL) {
2345 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
2346 PreviousVersionNode * pv_node = _previous_versions->at(i);
2347 delete pv_node;
2348 }
2349 delete _previous_versions;
2350 _previous_versions = NULL;
2351 }
2352
2353 // deallocate the cached class file
2354 if (_cached_class_file_bytes != NULL) {
2355 os::free(_cached_class_file_bytes, mtClass);
2356 _cached_class_file_bytes = NULL;
2357 _cached_class_file_len = 0;
2358 }
2359
2360 // Decrement symbol reference counts associated with the unloaded class.
2361 if (_name != NULL) _name->decrement_refcount();
2362 // unreference array name derived from this class name (arrays of an unloaded
2363 // class can't be referenced anymore).
2364 if (_array_name != NULL) _array_name->decrement_refcount();
2365 if (_source_file_name != NULL) _source_file_name->decrement_refcount();
2366 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
2367
2368 assert(_total_instanceKlass_count >= 1, "Sanity check");
2369 Atomic::dec(&_total_instanceKlass_count);
2370 }
2371
2372 void InstanceKlass::set_source_file_name(Symbol* n) {
2373 _source_file_name = n;
2374 if (_source_file_name != NULL) _source_file_name->increment_refcount();
2375 }
2376
2377 void InstanceKlass::set_source_debug_extension(char* array, int length) {
2378 if (array == NULL) {
2379 _source_debug_extension = NULL;
2380 } else {
2381 // Adding one to the attribute length in order to store a null terminator
2382 // character could cause an overflow because the attribute length is
2383 // already coded with an u4 in the classfile, but in practice, it's
2384 // unlikely to happen.
2385 assert((length+1) > length, "Overflow checking");
2386 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2387 for (int i = 0; i < length; i++) {
2388 sde[i] = array[i];
2389 }
2390 sde[length] = '\0';
2391 _source_debug_extension = sde;
2392 }
2393 }
2394
2395 address InstanceKlass::static_field_addr(int offset) {
2396 return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + (intptr_t)java_mirror());
2397 }
2398
2399
2400 const char* InstanceKlass::signature_name() const {
2401 const char* src = (const char*) (name()->as_C_string());
2402 const int src_length = (int)strlen(src);
2403 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
2404 int src_index = 0;
2405 int dest_index = 0;
2406 dest[dest_index++] = 'L';
2407 while (src_index < src_length) {
2408 dest[dest_index++] = src[src_index++];
2409 }
2410 dest[dest_index++] = ';';
2411 dest[dest_index] = '\0';
2412 return dest;
2413 }
2414
2415 // different verisons of is_same_class_package
2416 bool InstanceKlass::is_same_class_package(Klass* class2) {
2417 Klass* class1 = this;
2418 oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2419 Symbol* classname1 = class1->name();
2420
2421 if (class2->oop_is_objArray()) {
2422 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2423 }
2424 oop classloader2;
2425 if (class2->oop_is_instance()) {
2426 classloader2 = InstanceKlass::cast(class2)->class_loader();
2427 } else {
2428 assert(class2->oop_is_typeArray(), "should be type array");
2429 classloader2 = NULL;
2430 }
2431 Symbol* classname2 = class2->name();
2432
2433 return InstanceKlass::is_same_class_package(classloader1, classname1,
2434 classloader2, classname2);
2435 }
2436
2437 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
2438 Klass* class1 = this;
2439 oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2440 Symbol* classname1 = class1->name();
2441
2442 return InstanceKlass::is_same_class_package(classloader1, classname1,
2443 classloader2, classname2);
2444 }
2445
2446 // return true if two classes are in the same package, classloader
2447 // and classname information is enough to determine a class's package
2448 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
2449 oop class_loader2, Symbol* class_name2) {
2450 if (class_loader1 != class_loader2) {
2451 return false;
2452 } else if (class_name1 == class_name2) {
2453 return true; // skip painful bytewise comparison
2454 } else {
2455 ResourceMark rm;
2456
2457 // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
2458 // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
2459 // Otherwise, we just compare jbyte values between the strings.
2460 const jbyte *name1 = class_name1->base();
2461 const jbyte *name2 = class_name2->base();
2462
2463 const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
2464 const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
2465
2466 if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
2467 // One of the two doesn't have a package. Only return true
2468 // if the other one also doesn't have a package.
2469 return last_slash1 == last_slash2;
2470 } else {
2471 // Skip over '['s
2472 if (*name1 == '[') {
2473 do {
2474 name1++;
2475 } while (*name1 == '[');
2476 if (*name1 != 'L') {
2477 // Something is terribly wrong. Shouldn't be here.
2478 return false;
2479 }
2480 }
2481 if (*name2 == '[') {
2482 do {
2483 name2++;
2484 } while (*name2 == '[');
2485 if (*name2 != 'L') {
2486 // Something is terribly wrong. Shouldn't be here.
2487 return false;
2488 }
2489 }
2490
2491 // Check that package part is identical
2492 int length1 = last_slash1 - name1;
2493 int length2 = last_slash2 - name2;
2494
2495 return UTF8::equal(name1, length1, name2, length2);
2496 }
2497 }
2498 }
2499
2500 // Returns true iff super_method can be overridden by a method in targetclassname
2501 // See JSL 3rd edition 8.4.6.1
2502 // Assumes name-signature match
2503 // "this" is InstanceKlass of super_method which must exist
2504 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2505 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2506 // Private methods can not be overridden
2507 if (super_method->is_private()) {
2508 return false;
2509 }
2510 // If super method is accessible, then override
2511 if ((super_method->is_protected()) ||
2512 (super_method->is_public())) {
2513 return true;
2514 }
2515 // Package-private methods are not inherited outside of package
2516 assert(super_method->is_package_private(), "must be package private");
2517 return(is_same_class_package(targetclassloader(), targetclassname));
2518 }
2519
2520 /* defined for now in jvm.cpp, for historical reasons *--
2521 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2522 Symbol*& simple_name_result, TRAPS) {
2523 ...
2524 }
2525 */
2526
2527 // tell if two classes have the same enclosing class (at package level)
2528 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2529 Klass* class2_oop, TRAPS) {
2530 if (class2_oop == class1()) return true;
2531 if (!class2_oop->oop_is_instance()) return false;
2532 instanceKlassHandle class2(THREAD, class2_oop);
2533
2534 // must be in same package before we try anything else
2535 if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2536 return false;
2537
2538 // As long as there is an outer1.getEnclosingClass,
2539 // shift the search outward.
2540 instanceKlassHandle outer1 = class1;
2541 for (;;) {
2542 // As we walk along, look for equalities between outer1 and class2.
2543 // Eventually, the walks will terminate as outer1 stops
2544 // at the top-level class around the original class.
2545 bool ignore_inner_is_member;
2546 Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2547 CHECK_false);
2548 if (next == NULL) break;
2549 if (next == class2()) return true;
2550 outer1 = instanceKlassHandle(THREAD, next);
2551 }
2552
2553 // Now do the same for class2.
2554 instanceKlassHandle outer2 = class2;
2555 for (;;) {
2556 bool ignore_inner_is_member;
2557 Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2558 CHECK_false);
2559 if (next == NULL) break;
2560 // Might as well check the new outer against all available values.
2561 if (next == class1()) return true;
2562 if (next == outer1()) return true;
2563 outer2 = instanceKlassHandle(THREAD, next);
2564 }
2565
2566 // If by this point we have not found an equality between the
2567 // two classes, we know they are in separate package members.
2568 return false;
2569 }
2570
2571
2572 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2573 jint access = access_flags().as_int();
2574
2575 // But check if it happens to be member class.
2576 instanceKlassHandle ik(THREAD, this);
2577 InnerClassesIterator iter(ik);
2578 for (; !iter.done(); iter.next()) {
2579 int ioff = iter.inner_class_info_index();
2580 // Inner class attribute can be zero, skip it.
2581 // Strange but true: JVM spec. allows null inner class refs.
2582 if (ioff == 0) continue;
2583
2584 // only look at classes that are already loaded
2585 // since we are looking for the flags for our self.
2586 Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2587 if ((ik->name() == inner_name)) {
2588 // This is really a member class.
2589 access = iter.inner_access_flags();
2590 break;
2591 }
2592 }
2593 // Remember to strip ACC_SUPER bit
2594 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2595 }
2596
2597 jint InstanceKlass::jvmti_class_status() const {
2598 jint result = 0;
2599
2600 if (is_linked()) {
2601 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2602 }
2603
2604 if (is_initialized()) {
2605 assert(is_linked(), "Class status is not consistent");
2606 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2607 }
2608 if (is_in_error_state()) {
2609 result |= JVMTI_CLASS_STATUS_ERROR;
2610 }
2611 return result;
2612 }
2613
2614 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2615 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2616 int method_table_offset_in_words = ioe->offset()/wordSize;
2617 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2618 / itableOffsetEntry::size();
2619
2620 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2621 // If the interface isn't implemented by the receiver class,
2622 // the VM should throw IncompatibleClassChangeError.
2623 if (cnt >= nof_interfaces) {
2624 THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2625 }
2626
2627 Klass* ik = ioe->interface_klass();
2628 if (ik == holder) break;
2629 }
2630
2631 itableMethodEntry* ime = ioe->first_method_entry(this);
2632 Method* m = ime[index].method();
2633 if (m == NULL) {
2634 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2635 }
2636 return m;
2637 }
2638
2639 // On-stack replacement stuff
2640 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2641 // only one compilation can be active
2642 NEEDS_CLEANUP
2643 // This is a short non-blocking critical region, so the no safepoint check is ok.
2644 OsrList_lock->lock_without_safepoint_check();
2645 assert(n->is_osr_method(), "wrong kind of nmethod");
2646 n->set_osr_link(osr_nmethods_head());
2647 set_osr_nmethods_head(n);
2648 // Raise the highest osr level if necessary
2649 if (TieredCompilation) {
2650 Method* m = n->method();
2651 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2652 }
2653 // Remember to unlock again
2654 OsrList_lock->unlock();
2655
2656 // Get rid of the osr methods for the same bci that have lower levels.
2657 if (TieredCompilation) {
2658 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2659 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2660 if (inv != NULL && inv->is_in_use()) {
2661 inv->make_not_entrant();
2662 }
2663 }
2664 }
2665 }
2666
2667
2668 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
2669 // This is a short non-blocking critical region, so the no safepoint check is ok.
2670 OsrList_lock->lock_without_safepoint_check();
2671 assert(n->is_osr_method(), "wrong kind of nmethod");
2672 nmethod* last = NULL;
2673 nmethod* cur = osr_nmethods_head();
2674 int max_level = CompLevel_none; // Find the max comp level excluding n
2675 Method* m = n->method();
2676 // Search for match
2677 while(cur != NULL && cur != n) {
2678 if (TieredCompilation) {
2679 // Find max level before n
2680 max_level = MAX2(max_level, cur->comp_level());
2681 }
2682 last = cur;
2683 cur = cur->osr_link();
2684 }
2685 nmethod* next = NULL;
2686 if (cur == n) {
2687 next = cur->osr_link();
2688 if (last == NULL) {
2689 // Remove first element
2690 set_osr_nmethods_head(next);
2691 } else {
2692 last->set_osr_link(next);
2693 }
2694 }
2695 n->set_osr_link(NULL);
2696 if (TieredCompilation) {
2697 cur = next;
2698 while (cur != NULL) {
2699 // Find max level after n
2700 max_level = MAX2(max_level, cur->comp_level());
2701 cur = cur->osr_link();
2702 }
2703 m->set_highest_osr_comp_level(max_level);
2704 }
2705 // Remember to unlock again
2706 OsrList_lock->unlock();
2707 }
2708
2709 nmethod* InstanceKlass::lookup_osr_nmethod(Method* const m, int bci, int comp_level, bool match_level) const {
2710 // This is a short non-blocking critical region, so the no safepoint check is ok.
2711 OsrList_lock->lock_without_safepoint_check();
2712 nmethod* osr = osr_nmethods_head();
2713 nmethod* best = NULL;
2714 while (osr != NULL) {
2715 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2716 // There can be a time when a c1 osr method exists but we are waiting
2717 // for a c2 version. When c2 completes its osr nmethod we will trash
2718 // the c1 version and only be able to find the c2 version. However
2719 // while we overflow in the c1 code at back branches we don't want to
2720 // try and switch to the same code as we are already running
2721
2722 if (osr->method() == m &&
2723 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2724 if (match_level) {
2725 if (osr->comp_level() == comp_level) {
2726 // Found a match - return it.
2727 OsrList_lock->unlock();
2728 return osr;
2729 }
2730 } else {
2731 if (best == NULL || (osr->comp_level() > best->comp_level())) {
2732 if (osr->comp_level() == CompLevel_highest_tier) {
2733 // Found the best possible - return it.
2734 OsrList_lock->unlock();
2735 return osr;
2736 }
2737 best = osr;
2738 }
2739 }
2740 }
2741 osr = osr->osr_link();
2742 }
2743 OsrList_lock->unlock();
2744 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2745 return best;
2746 }
2747 return NULL;
2748 }
2749
2750 // -----------------------------------------------------------------------------------------------------
2751 // Printing
2752
2753 #ifndef PRODUCT
2754
2755 #define BULLET " - "
2756
2757 static const char* state_names[] = {
2758 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2759 };
2760
2761 void InstanceKlass::print_on(outputStream* st) const {
2762 assert(is_klass(), "must be klass");
2763 Klass::print_on(st);
2764
2765 st->print(BULLET"instance size: %d", size_helper()); st->cr();
2766 st->print(BULLET"klass size: %d", size()); st->cr();
2767 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
2768 st->print(BULLET"state: "); st->print_cr(state_names[_init_state]);
2769 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
2770 st->print(BULLET"super: "); super()->print_value_on_maybe_null(st); st->cr();
2771 st->print(BULLET"sub: ");
2772 Klass* sub = subklass();
2773 int n;
2774 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2775 if (n < MaxSubklassPrintSize) {
2776 sub->print_value_on(st);
2777 st->print(" ");
2778 }
2779 }
2780 if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
2781 st->cr();
2782
2783 if (is_interface()) {
2784 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
2785 if (nof_implementors() == 1) {
2786 st->print_cr(BULLET"implementor: ");
2787 st->print(" ");
2788 implementor()->print_value_on(st);
2789 st->cr();
2790 }
2791 }
2792
2793 st->print(BULLET"arrays: "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2794 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
2795 if (Verbose) {
2796 Array<Method*>* method_array = methods();
2797 for(int i = 0; i < method_array->length(); i++) {
2798 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2799 }
2800 }
2801 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
2802 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
2803 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2804 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
2805 if (class_loader_data() != NULL) {
2806 st->print(BULLET"class loader data: ");
2807 class_loader_data()->print_value_on(st);
2808 st->cr();
2809 }
2810 st->print(BULLET"protection domain: "); ((InstanceKlass*)this)->protection_domain()->print_value_on(st); st->cr();
2811 st->print(BULLET"host class: "); host_klass()->print_value_on_maybe_null(st); st->cr();
2812 st->print(BULLET"signers: "); signers()->print_value_on(st); st->cr();
2813 st->print(BULLET"per_class_lock: "); ((oop)_per_class_lock)->print_value_on(st); st->cr();
2814 if (source_file_name() != NULL) {
2815 st->print(BULLET"source file: ");
2816 source_file_name()->print_value_on(st);
2817 st->cr();
2818 }
2819 if (source_debug_extension() != NULL) {
2820 st->print(BULLET"source debug extension: ");
2821 st->print("%s", source_debug_extension());
2822 st->cr();
2823 }
2824 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
2825 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
2826 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
2827 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
2828 {
2829 ResourceMark rm;
2830 // PreviousVersionInfo objects returned via PreviousVersionWalker
2831 // contain a GrowableArray of handles. We have to clean up the
2832 // GrowableArray _after_ the PreviousVersionWalker destructor
2833 // has destroyed the handles.
2834 {
2835 bool have_pv = false;
2836 PreviousVersionWalker pvw((InstanceKlass*)this);
2837 for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
2838 pv_info != NULL; pv_info = pvw.next_previous_version()) {
2839 if (!have_pv)
2840 st->print(BULLET"previous version: ");
2841 have_pv = true;
2842 pv_info->prev_constant_pool_handle()()->print_value_on(st);
2843 }
2844 if (have_pv) st->cr();
2845 } // pvw is cleaned up
2846 } // rm is cleaned up
2847
2848 if (generic_signature() != NULL) {
2849 st->print(BULLET"generic signature: ");
2850 generic_signature()->print_value_on(st);
2851 st->cr();
2852 }
2853 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
2854 st->print(BULLET"java mirror: "); java_mirror()->print_value_on(st); st->cr();
2855 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable()); st->cr();
2856 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
2857 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2858 FieldPrinter print_static_field(st);
2859 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2860 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2861 FieldPrinter print_nonstatic_field(st);
2862 ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
2863
2864 st->print(BULLET"non-static oop maps: ");
2865 OopMapBlock* map = start_of_nonstatic_oop_maps();
2866 OopMapBlock* end_map = map + nonstatic_oop_map_count();
2867 while (map < end_map) {
2868 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2869 map++;
2870 }
2871 st->cr();
2872 }
2873
2874 #endif //PRODUCT
2875
2876 void InstanceKlass::print_value_on(outputStream* st) const {
2877 assert(is_klass(), "must be klass");
2878 name()->print_value_on(st);
2879 }
2880
2881 #ifndef PRODUCT
2882
2883 void FieldPrinter::do_field(fieldDescriptor* fd) {
2884 _st->print(BULLET);
2885 if (_obj == NULL) {
2886 fd->print_on(_st);
2887 _st->cr();
2888 } else {
2889 fd->print_on_for(_st, _obj);
2890 _st->cr();
2891 }
2892 }
2893
2894
2895 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
2896 Klass::oop_print_on(obj, st);
2897
2898 if (this == SystemDictionary::String_klass()) {
2899 typeArrayOop value = java_lang_String::value(obj);
2900 juint offset = java_lang_String::offset(obj);
2901 juint length = java_lang_String::length(obj);
2902 if (value != NULL &&
2903 value->is_typeArray() &&
2904 offset <= (juint) value->length() &&
2905 offset + length <= (juint) value->length()) {
2906 st->print(BULLET"string: ");
2907 Handle h_obj(obj);
2908 java_lang_String::print(h_obj, st);
2909 st->cr();
2910 if (!WizardMode) return; // that is enough
2911 }
2912 }
2913
2914 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
2915 FieldPrinter print_field(st, obj);
2916 do_nonstatic_fields(&print_field);
2917
2918 if (this == SystemDictionary::Class_klass()) {
2919 st->print(BULLET"signature: ");
2920 java_lang_Class::print_signature(obj, st);
2921 st->cr();
2922 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
2923 st->print(BULLET"fake entry for mirror: ");
2924 mirrored_klass->print_value_on_maybe_null(st);
2925 st->cr();
2926 Klass* array_klass = java_lang_Class::array_klass(obj);
2927 st->print(BULLET"fake entry for array: ");
2928 array_klass->print_value_on_maybe_null(st);
2929 st->cr();
2930 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
2931 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
2932 Klass* real_klass = java_lang_Class::as_Klass(obj);
2933 if (real_klass != NULL && real_klass->oop_is_instance()) {
2934 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
2935 }
2936 } else if (this == SystemDictionary::MethodType_klass()) {
2937 st->print(BULLET"signature: ");
2938 java_lang_invoke_MethodType::print_signature(obj, st);
2939 st->cr();
2940 }
2941 }
2942
2943 #endif //PRODUCT
2944
2945 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
2946 st->print("a ");
2947 name()->print_value_on(st);
2948 obj->print_address_on(st);
2949 if (this == SystemDictionary::String_klass()
2950 && java_lang_String::value(obj) != NULL) {
2951 ResourceMark rm;
2952 int len = java_lang_String::length(obj);
2953 int plen = (len < 24 ? len : 12);
2954 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
2955 st->print(" = \"%s\"", str);
2956 if (len > plen)
2957 st->print("...[%d]", len);
2958 } else if (this == SystemDictionary::Class_klass()) {
2959 Klass* k = java_lang_Class::as_Klass(obj);
2960 st->print(" = ");
2961 if (k != NULL) {
2962 k->print_value_on(st);
2963 } else {
2964 const char* tname = type2name(java_lang_Class::primitive_type(obj));
2965 st->print("%s", tname ? tname : "type?");
2966 }
2967 } else if (this == SystemDictionary::MethodType_klass()) {
2968 st->print(" = ");
2969 java_lang_invoke_MethodType::print_signature(obj, st);
2970 } else if (java_lang_boxing_object::is_instance(obj)) {
2971 st->print(" = ");
2972 java_lang_boxing_object::print(obj, st);
2973 } else if (this == SystemDictionary::LambdaForm_klass()) {
2974 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
2975 if (vmentry != NULL) {
2976 st->print(" => ");
2977 vmentry->print_value_on(st);
2978 }
2979 } else if (this == SystemDictionary::MemberName_klass()) {
2980 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
2981 if (vmtarget != NULL) {
2982 st->print(" = ");
2983 vmtarget->print_value_on(st);
2984 } else {
2985 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
2986 st->print(".");
2987 java_lang_invoke_MemberName::name(obj)->print_value_on(st);
2988 }
2989 }
2990 }
2991
2992 const char* InstanceKlass::internal_name() const {
2993 return external_name();
2994 }
2995
2996 #if INCLUDE_SERVICES
2997 // Size Statistics
2998 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
2999 Klass::collect_statistics(sz);
3000
3001 sz->_inst_size = HeapWordSize * size_helper();
3002 sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
3003 sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
3004 sz->_nonstatic_oopmap_bytes = HeapWordSize *
3005 ((is_interface() || is_anonymous()) ?
3006 align_object_offset(nonstatic_oop_map_size()) :
3007 nonstatic_oop_map_size());
3008
3009 int n = 0;
3010 n += (sz->_methods_array_bytes = sz->count_array(methods()));
3011 n += (sz->_method_ordering_bytes = sz->count_array(method_ordering()));
3012 n += (sz->_local_interfaces_bytes = sz->count_array(local_interfaces()));
3013 n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3014 n += (sz->_signers_bytes = sz->count_array(signers()));
3015 n += (sz->_fields_bytes = sz->count_array(fields()));
3016 n += (sz->_inner_classes_bytes = sz->count_array(inner_classes()));
3017 sz->_ro_bytes += n;
3018
3019 const ConstantPool* cp = constants();
3020 if (cp) {
3021 cp->collect_statistics(sz);
3022 }
3023
3024 const Annotations* anno = annotations();
3025 if (anno) {
3026 anno->collect_statistics(sz);
3027 }
3028
3029 const Array<Method*>* methods_array = methods();
3030 if (methods()) {
3031 for (int i = 0; i < methods_array->length(); i++) {
3032 Method* method = methods_array->at(i);
3033 if (method) {
3034 sz->_method_count ++;
3035 method->collect_statistics(sz);
3036 }
3037 }
3038 }
3039 }
3040 #endif // INCLUDE_SERVICES
3041
3042 // Verification
3043
3044 class VerifyFieldClosure: public OopClosure {
3045 protected:
3046 template <class T> void do_oop_work(T* p) {
3047 oop obj = oopDesc::load_decode_heap_oop(p);
3048 if (!obj->is_oop_or_null()) {
3049 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
3050 Universe::print();
3051 guarantee(false, "boom");
3052 }
3053 }
3054 public:
3055 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3056 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3057 };
3058
3059 void InstanceKlass::verify_on(outputStream* st) {
3060 Klass::verify_on(st);
3061 Thread *thread = Thread::current();
3062
3063 #ifndef PRODUCT
3064 // Avoid redundant verifies
3065 if (_verify_count == Universe::verify_count()) return;
3066 _verify_count = Universe::verify_count();
3067 #endif
3068 // Verify that klass is present in SystemDictionary
3069 if (is_loaded() && !is_anonymous()) {
3070 Symbol* h_name = name();
3071 SystemDictionary::verify_obj_klass_present(h_name, class_loader_data());
3072 }
3073
3074 // Verify static fields
3075 VerifyFieldClosure blk;
3076
3077 // Verify vtables
3078 if (is_linked()) {
3079 ResourceMark rm(thread);
3080 // $$$ This used to be done only for m/s collections. Doing it
3081 // always seemed a valid generalization. (DLD -- 6/00)
3082 vtable()->verify(st);
3083 }
3084
3085 // Verify first subklass
3086 if (subklass_oop() != NULL) {
3087 guarantee(subklass_oop()->is_metadata(), "should be in metaspace");
3088 guarantee(subklass_oop()->is_klass(), "should be klass");
3089 }
3090
3091 // Verify siblings
3092 Klass* super = this->super();
3093 Klass* sib = next_sibling();
3094 if (sib != NULL) {
3095 if (sib == this) {
3096 fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
3097 }
3098
3099 guarantee(sib->is_metadata(), "should be in metaspace");
3100 guarantee(sib->is_klass(), "should be klass");
3101 guarantee(sib->super() == super, "siblings should have same superklass");
3102 }
3103
3104 // Verify implementor fields
3105 Klass* im = implementor();
3106 if (im != NULL) {
3107 guarantee(is_interface(), "only interfaces should have implementor set");
3108 guarantee(im->is_klass(), "should be klass");
3109 guarantee(!im->is_interface() || im == this,
3110 "implementors cannot be interfaces");
3111 }
3112
3113 // Verify local interfaces
3114 if (local_interfaces()) {
3115 Array<Klass*>* local_interfaces = this->local_interfaces();
3116 for (int j = 0; j < local_interfaces->length(); j++) {
3117 Klass* e = local_interfaces->at(j);
3118 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3119 }
3120 }
3121
3122 // Verify transitive interfaces
3123 if (transitive_interfaces() != NULL) {
3124 Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3125 for (int j = 0; j < transitive_interfaces->length(); j++) {
3126 Klass* e = transitive_interfaces->at(j);
3127 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3128 }
3129 }
3130
3131 // Verify methods
3132 if (methods() != NULL) {
3133 Array<Method*>* methods = this->methods();
3134 for (int j = 0; j < methods->length(); j++) {
3135 guarantee(methods->at(j)->is_metadata(), "should be in metaspace");
3136 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3137 }
3138 for (int j = 0; j < methods->length() - 1; j++) {
3139 Method* m1 = methods->at(j);
3140 Method* m2 = methods->at(j + 1);
3141 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3142 }
3143 }
3144
3145 // Verify method ordering
3146 if (method_ordering() != NULL) {
3147 Array<int>* method_ordering = this->method_ordering();
3148 int length = method_ordering->length();
3149 if (JvmtiExport::can_maintain_original_method_order() ||
3150 (UseSharedSpaces && length != 0)) {
3151 guarantee(length == methods()->length(), "invalid method ordering length");
3152 jlong sum = 0;
3153 for (int j = 0; j < length; j++) {
3154 int original_index = method_ordering->at(j);
3155 guarantee(original_index >= 0, "invalid method ordering index");
3156 guarantee(original_index < length, "invalid method ordering index");
3157 sum += original_index;
3158 }
3159 // Verify sum of indices 0,1,...,length-1
3160 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3161 } else {
3162 guarantee(length == 0, "invalid method ordering length");
3163 }
3164 }
3165
3166 // Verify JNI static field identifiers
3167 if (jni_ids() != NULL) {
3168 jni_ids()->verify(this);
3169 }
3170
3171 // Verify other fields
3172 if (array_klasses() != NULL) {
3173 guarantee(array_klasses()->is_metadata(), "should be in metaspace");
3174 guarantee(array_klasses()->is_klass(), "should be klass");
3175 }
3176 if (constants() != NULL) {
3177 guarantee(constants()->is_metadata(), "should be in metaspace");
3178 guarantee(constants()->is_constantPool(), "should be constant pool");
3179 }
3180 if (protection_domain() != NULL) {
3181 guarantee(protection_domain()->is_oop(), "should be oop");
3182 }
3183 const Klass* host = host_klass();
3184 if (host != NULL) {
3185 guarantee(host->is_metadata(), "should be in metaspace");
3186 guarantee(host->is_klass(), "should be klass");
3187 }
3188 if (signers() != NULL) {
3189 guarantee(signers()->is_objArray(), "should be obj array");
3190 }
3191 }
3192
3193 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3194 Klass::oop_verify_on(obj, st);
3195 VerifyFieldClosure blk;
3196 obj->oop_iterate_no_header(&blk);
3197 }
3198
3199
3200 // JNIid class for jfieldIDs only
3201 // Note to reviewers:
3202 // These JNI functions are just moved over to column 1 and not changed
3203 // in the compressed oops workspace.
3204 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3205 _holder = holder;
3206 _offset = offset;
3207 _next = next;
3208 debug_only(_is_static_field_id = false;)
3209 }
3210
3211
3212 JNIid* JNIid::find(int offset) {
3213 JNIid* current = this;
3214 while (current != NULL) {
3215 if (current->offset() == offset) return current;
3216 current = current->next();
3217 }
3218 return NULL;
3219 }
3220
3221 void JNIid::deallocate(JNIid* current) {
3222 while (current != NULL) {
3223 JNIid* next = current->next();
3224 delete current;
3225 current = next;
3226 }
3227 }
3228
3229
3230 void JNIid::verify(Klass* holder) {
3231 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3232 int end_field_offset;
3233 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3234
3235 JNIid* current = this;
3236 while (current != NULL) {
3237 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3238 #ifdef ASSERT
3239 int o = current->offset();
3240 if (current->is_static_field_id()) {
3241 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3242 }
3243 #endif
3244 current = current->next();
3245 }
3246 }
3247
3248
3249 #ifdef ASSERT
3250 void InstanceKlass::set_init_state(ClassState state) {
3251 bool good_state = is_shared() ? (_init_state <= state)
3252 : (_init_state < state);
3253 assert(good_state || state == allocated, "illegal state transition");
3254 _init_state = (u1)state;
3255 }
3256 #endif
3257
3258
3259 // RedefineClasses() support for previous versions:
3260
3261 // Purge previous versions
3262 static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
3263 if (ik->previous_versions() != NULL) {
3264 // This klass has previous versions so see what we can cleanup
3265 // while it is safe to do so.
3266
3267 int deleted_count = 0; // leave debugging breadcrumbs
3268 int live_count = 0;
3269 ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
3270 ClassLoaderData::the_null_class_loader_data() :
3271 ik->class_loader_data();
3272
3273 // RC_TRACE macro has an embedded ResourceMark
3274 RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
3275 ik->external_name(), ik->previous_versions()->length()));
3276
3277 for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
3278 // check the previous versions array
3279 PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
3280 ConstantPool* cp_ref = pv_node->prev_constant_pool();
3281 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
3282
3283 ConstantPool* pvcp = cp_ref;
3284 if (!pvcp->on_stack()) {
3285 // If the constant pool isn't on stack, none of the methods
3286 // are executing. Delete all the methods, the constant pool and
3287 // and this previous version node.
3288 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3289 if (method_refs != NULL) {
3290 for (int j = method_refs->length() - 1; j >= 0; j--) {
3291 Method* method = method_refs->at(j);
3292 assert(method != NULL, "method ref was unexpectedly cleared");
3293 method_refs->remove_at(j);
3294 // method will be freed with associated class.
3295 }
3296 }
3297 // Remove the constant pool
3298 delete pv_node;
3299 // Since we are traversing the array backwards, we don't have to
3300 // do anything special with the index.
3301 ik->previous_versions()->remove_at(i);
3302 deleted_count++;
3303 continue;
3304 } else {
3305 RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
3306 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3307 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3308 live_count++;
3309 }
3310
3311 // At least one method is live in this previous version, clean out
3312 // the others or mark them as obsolete.
3313 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3314 if (method_refs != NULL) {
3315 RC_TRACE(0x00000200, ("purge: previous methods length=%d",
3316 method_refs->length()));
3317 for (int j = method_refs->length() - 1; j >= 0; j--) {
3318 Method* method = method_refs->at(j);
3319 assert(method != NULL, "method ref was unexpectedly cleared");
3320
3321 // Remove the emcp method if it's not executing
3322 // If it's been made obsolete by a redefinition of a non-emcp
3323 // method, mark it as obsolete but leave it to clean up later.
3324 if (!method->on_stack()) {
3325 method_refs->remove_at(j);
3326 } else if (emcp_method_count == 0) {
3327 method->set_is_obsolete();
3328 } else {
3329 // RC_TRACE macro has an embedded ResourceMark
3330 RC_TRACE(0x00000200,
3331 ("purge: %s(%s): prev method @%d in version @%d is alive",
3332 method->name()->as_C_string(),
3333 method->signature()->as_C_string(), j, i));
3334 }
3335 }
3336 }
3337 }
3338 assert(ik->previous_versions()->length() == live_count, "sanity check");
3339 RC_TRACE(0x00000200,
3340 ("purge: previous version stats: live=%d, deleted=%d", live_count,
3341 deleted_count));
3342 }
3343 }
3344
3345 // External interface for use during class unloading.
3346 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
3347 // Call with >0 emcp methods since they are not currently being redefined.
3348 purge_previous_versions_internal(ik, 1);
3349 }
3350
3351
3352 // Potentially add an information node that contains pointers to the
3353 // interesting parts of the previous version of the_class.
3354 // This is also where we clean out any unused references.
3355 // Note that while we delete nodes from the _previous_versions
3356 // array, we never delete the array itself until the klass is
3357 // unloaded. The has_been_redefined() query depends on that fact.
3358 //
3359 void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
3360 BitMap* emcp_methods, int emcp_method_count) {
3361 assert(Thread::current()->is_VM_thread(),
3362 "only VMThread can add previous versions");
3363
3364 if (_previous_versions == NULL) {
3365 // This is the first previous version so make some space.
3366 // Start with 2 elements under the assumption that the class
3367 // won't be redefined much.
3368 _previous_versions = new (ResourceObj::C_HEAP, mtClass)
3369 GrowableArray<PreviousVersionNode *>(2, true);
3370 }
3371
3372 ConstantPool* cp_ref = ikh->constants();
3373
3374 // RC_TRACE macro has an embedded ResourceMark
3375 RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
3376 "on_stack=%d",
3377 ikh->external_name(), _previous_versions->length(), emcp_method_count,
3378 cp_ref->on_stack()));
3379
3380 // If the constant pool for this previous version of the class
3381 // is not marked as being on the stack, then none of the methods
3382 // in this previous version of the class are on the stack so
3383 // we don't need to create a new PreviousVersionNode. However,
3384 // we still need to examine older previous versions below.
3385 Array<Method*>* old_methods = ikh->methods();
3386
3387 if (cp_ref->on_stack()) {
3388 PreviousVersionNode * pv_node = NULL;
3389 if (emcp_method_count == 0) {
3390 // non-shared ConstantPool gets a reference
3391 pv_node = new PreviousVersionNode(cp_ref, !cp_ref->is_shared(), NULL);
3392 RC_TRACE(0x00000400,
3393 ("add: all methods are obsolete; flushing any EMCP refs"));
3394 } else {
3395 int local_count = 0;
3396 GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
3397 GrowableArray<Method*>(emcp_method_count, true);
3398 for (int i = 0; i < old_methods->length(); i++) {
3399 if (emcp_methods->at(i)) {
3400 // this old method is EMCP. Save it only if it's on the stack
3401 Method* old_method = old_methods->at(i);
3402 if (old_method->on_stack()) {
3403 method_refs->append(old_method);
3404 }
3405 if (++local_count >= emcp_method_count) {
3406 // no more EMCP methods so bail out now
3407 break;
3408 }
3409 }
3410 }
3411 // non-shared ConstantPool gets a reference
3412 pv_node = new PreviousVersionNode(cp_ref, !cp_ref->is_shared(), method_refs);
3413 }
3414 // append new previous version.
3415 _previous_versions->append(pv_node);
3416 }
3417
3418 // Since the caller is the VMThread and we are at a safepoint, this
3419 // is a good time to clear out unused references.
3420
3421 RC_TRACE(0x00000400, ("add: previous version length=%d",
3422 _previous_versions->length()));
3423
3424 // Purge previous versions not executing on the stack
3425 purge_previous_versions_internal(this, emcp_method_count);
3426
3427 int obsolete_method_count = old_methods->length() - emcp_method_count;
3428
3429 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3430 _previous_versions->length() > 0) {
3431 // We have a mix of obsolete and EMCP methods so we have to
3432 // clear out any matching EMCP method entries the hard way.
3433 int local_count = 0;
3434 for (int i = 0; i < old_methods->length(); i++) {
3435 if (!emcp_methods->at(i)) {
3436 // only obsolete methods are interesting
3437 Method* old_method = old_methods->at(i);
3438 Symbol* m_name = old_method->name();
3439 Symbol* m_signature = old_method->signature();
3440
3441 // we might not have added the last entry
3442 for (int j = _previous_versions->length() - 1; j >= 0; j--) {
3443 // check the previous versions array for non executing obsolete methods
3444 PreviousVersionNode * pv_node = _previous_versions->at(j);
3445
3446 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3447 if (method_refs == NULL) {
3448 // We have run into a PreviousVersion generation where
3449 // all methods were made obsolete during that generation's
3450 // RedefineClasses() operation. At the time of that
3451 // operation, all EMCP methods were flushed so we don't
3452 // have to go back any further.
3453 //
3454 // A NULL method_refs is different than an empty method_refs.
3455 // We cannot infer any optimizations about older generations
3456 // from an empty method_refs for the current generation.
3457 break;
3458 }
3459
3460 for (int k = method_refs->length() - 1; k >= 0; k--) {
3461 Method* method = method_refs->at(k);
3462
3463 if (!method->is_obsolete() &&
3464 method->name() == m_name &&
3465 method->signature() == m_signature) {
3466 // The current RedefineClasses() call has made all EMCP
3467 // versions of this method obsolete so mark it as obsolete
3468 // and remove the reference.
3469 RC_TRACE(0x00000400,
3470 ("add: %s(%s): flush obsolete method @%d in version @%d",
3471 m_name->as_C_string(), m_signature->as_C_string(), k, j));
3472
3473 method->set_is_obsolete();
3474 // Leave obsolete methods on the previous version list to
3475 // clean up later.
3476 break;
3477 }
3478 }
3479
3480 // The previous loop may not find a matching EMCP method, but
3481 // that doesn't mean that we can optimize and not go any
3482 // further back in the PreviousVersion generations. The EMCP
3483 // method for this generation could have already been deleted,
3484 // but there still may be an older EMCP method that has not
3485 // been deleted.
3486 }
3487
3488 if (++local_count >= obsolete_method_count) {
3489 // no more obsolete methods so bail out now
3490 break;
3491 }
3492 }
3493 }
3494 }
3495 } // end add_previous_version()
3496
3497
3498 // Determine if InstanceKlass has a previous version.
3499 bool InstanceKlass::has_previous_version() const {
3500 return (_previous_versions != NULL && _previous_versions->length() > 0);
3501 } // end has_previous_version()
3502
3503
3504 Method* InstanceKlass::method_with_idnum(int idnum) {
3505 Method* m = NULL;
3506 if (idnum < methods()->length()) {
3507 m = methods()->at(idnum);
3508 }
3509 if (m == NULL || m->method_idnum() != idnum) {
3510 for (int index = 0; index < methods()->length(); ++index) {
3511 m = methods()->at(index);
3512 if (m->method_idnum() == idnum) {
3513 return m;
3514 }
3515 }
3516 }
3517 return m;
3518 }
3519
3520
3521 // Construct a PreviousVersionNode entry for the array hung off
3522 // the InstanceKlass.
3523 PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
3524 bool prev_cp_is_weak, GrowableArray<Method*>* prev_EMCP_methods) {
3525
3526 _prev_constant_pool = prev_constant_pool;
3527 _prev_cp_is_weak = prev_cp_is_weak;
3528 _prev_EMCP_methods = prev_EMCP_methods;
3529 }
3530
3531
3532 // Destroy a PreviousVersionNode
3533 PreviousVersionNode::~PreviousVersionNode() {
3534 if (_prev_constant_pool != NULL) {
3535 _prev_constant_pool = NULL;
3536 }
3537
3538 if (_prev_EMCP_methods != NULL) {
3539 delete _prev_EMCP_methods;
3540 }
3541 }
3542
3543
3544 // Construct a PreviousVersionInfo entry
3545 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
3546 _prev_constant_pool_handle = constantPoolHandle(); // NULL handle
3547 _prev_EMCP_method_handles = NULL;
3548
3549 ConstantPool* cp = pv_node->prev_constant_pool();
3550 assert(cp != NULL, "constant pool ref was unexpectedly cleared");
3551 if (cp == NULL) {
3552 return; // robustness
3553 }
3554
3555 // make the ConstantPool* safe to return
3556 _prev_constant_pool_handle = constantPoolHandle(cp);
3557
3558 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3559 if (method_refs == NULL) {
3560 // the InstanceKlass did not have any EMCP methods
3561 return;
3562 }
3563
3564 _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
3565
3566 int n_methods = method_refs->length();
3567 for (int i = 0; i < n_methods; i++) {
3568 Method* method = method_refs->at(i);
3569 assert (method != NULL, "method has been cleared");
3570 if (method == NULL) {
3571 continue; // robustness
3572 }
3573 // make the Method* safe to return
3574 _prev_EMCP_method_handles->append(methodHandle(method));
3575 }
3576 }
3577
3578
3579 // Destroy a PreviousVersionInfo
3580 PreviousVersionInfo::~PreviousVersionInfo() {
3581 // Since _prev_EMCP_method_handles is not C-heap allocated, we
3582 // don't have to delete it.
3583 }
3584
3585
3586 // Construct a helper for walking the previous versions array
3587 PreviousVersionWalker::PreviousVersionWalker(InstanceKlass *ik) {
3588 _previous_versions = ik->previous_versions();
3589 _current_index = 0;
3590 // _hm needs no initialization
3591 _current_p = NULL;
3592 }
3593
3594
3595 // Destroy a PreviousVersionWalker
3596 PreviousVersionWalker::~PreviousVersionWalker() {
3597 // Delete the current info just in case the caller didn't walk to
3598 // the end of the previous versions list. No harm if _current_p is
3599 // already NULL.
3600 delete _current_p;
3601
3602 // When _hm is destroyed, all the Handles returned in
3603 // PreviousVersionInfo objects will be destroyed.
3604 // Also, after this destructor is finished it will be
3605 // safe to delete the GrowableArray allocated in the
3606 // PreviousVersionInfo objects.
3607 }
3608
3609
3610 // Return the interesting information for the next previous version
3611 // of the klass. Returns NULL if there are no more previous versions.
3612 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
3613 if (_previous_versions == NULL) {
3614 // no previous versions so nothing to return
3615 return NULL;
3616 }
3617
3618 delete _current_p; // cleanup the previous info for the caller
3619 _current_p = NULL; // reset to NULL so we don't delete same object twice
3620
3621 int length = _previous_versions->length();
3622
3623 while (_current_index < length) {
3624 PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
3625 PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP, mtClass)
3626 PreviousVersionInfo(pv_node);
3627
3628 constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
3629 assert (!cp_h.is_null(), "null cp found in previous version");
3630
3631 // The caller will need to delete pv_info when they are done with it.
3632 _current_p = pv_info;
3633 return pv_info;
3634 }
3635
3636 // all of the underlying nodes' info has been deleted
3637 return NULL;
3638 } // end next_previous_version()