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