1 /*
2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
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/metadataFactory.hpp"
38 #include "memory/oopFactory.hpp"
39 #include "oops/fieldStreams.hpp"
40 #include "oops/instanceClassLoaderKlass.hpp"
41 #include "oops/instanceKlass.hpp"
42 #include "oops/instanceMirrorKlass.hpp"
43 #include "oops/instanceOop.hpp"
44 #include "oops/klass.inline.hpp"
45 #include "oops/method.hpp"
46 #include "oops/oop.inline.hpp"
47 #include "oops/symbol.hpp"
48 #include "prims/jvmtiExport.hpp"
49 #include "prims/jvmtiRedefineClassesTrace.hpp"
50 #include "runtime/fieldDescriptor.hpp"
51 #include "runtime/handles.inline.hpp"
52 #include "runtime/javaCalls.hpp"
53 #include "runtime/mutexLocker.hpp"
54 #include "runtime/thread.inline.hpp"
55 #include "services/threadService.hpp"
56 #include "utilities/dtrace.hpp"
57 #ifndef SERIALGC
58 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
59 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
60 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
61 #include "gc_implementation/g1/g1RemSet.inline.hpp"
62 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
63 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
64 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
65 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
66 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
67 #include "oops/oop.pcgc.inline.hpp"
68 #endif
69 #ifdef COMPILER1
70 #include "c1/c1_Compiler.hpp"
71 #endif
72
73 #ifdef DTRACE_ENABLED
74
75 #ifndef USDT2
76
77 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
78 char*, intptr_t, oop, intptr_t);
79 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
80 char*, intptr_t, oop, intptr_t, int);
81 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
82 char*, intptr_t, oop, intptr_t, int);
83 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
84 char*, intptr_t, oop, intptr_t, int);
85 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
86 char*, intptr_t, oop, intptr_t, int);
87 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
88 char*, intptr_t, oop, intptr_t, int);
89 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
90 char*, intptr_t, oop, intptr_t, int);
91 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
92 char*, intptr_t, oop, intptr_t, int);
93
94 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
95 { \
96 char* data = NULL; \
97 int len = 0; \
98 Symbol* name = (clss)->name(); \
99 if (name != NULL) { \
100 data = (char*)name->bytes(); \
101 len = name->utf8_length(); \
102 } \
103 HS_DTRACE_PROBE4(hotspot, class__initialization__##type, \
104 data, len, (clss)->class_loader(), thread_type); \
105 }
106
107 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
108 { \
109 char* data = NULL; \
110 int len = 0; \
111 Symbol* name = (clss)->name(); \
112 if (name != NULL) { \
113 data = (char*)name->bytes(); \
114 len = name->utf8_length(); \
115 } \
116 HS_DTRACE_PROBE5(hotspot, class__initialization__##type, \
117 data, len, (clss)->class_loader(), thread_type, wait); \
118 }
119 #else /* USDT2 */
120
121 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
122 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
123 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
124 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
125 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
126 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
127 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
128 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
129 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
130 { \
131 char* data = NULL; \
132 int len = 0; \
133 Symbol* name = (clss)->name(); \
134 if (name != NULL) { \
135 data = (char*)name->bytes(); \
136 len = name->utf8_length(); \
137 } \
138 HOTSPOT_CLASS_INITIALIZATION_##type( \
139 data, len, (clss)->class_loader(), thread_type); \
140 }
141
142 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
143 { \
144 char* data = NULL; \
145 int len = 0; \
146 Symbol* name = (clss)->name(); \
147 if (name != NULL) { \
148 data = (char*)name->bytes(); \
149 len = name->utf8_length(); \
150 } \
151 HOTSPOT_CLASS_INITIALIZATION_##type( \
152 data, len, (clss)->class_loader(), thread_type, wait); \
153 }
154 #endif /* USDT2 */
155
156 #else // ndef DTRACE_ENABLED
157
158 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
159 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
160
161 #endif // ndef DTRACE_ENABLED
162
163 Klass* InstanceKlass::allocate_instance_klass(ClassLoaderData* loader_data,
164 int vtable_len,
165 int itable_len,
166 int static_field_size,
167 int nonstatic_oop_map_size,
168 ReferenceType rt,
169 AccessFlags access_flags,
170 Symbol* name,
171 Klass* super_klass,
172 KlassHandle host_klass,
173 TRAPS) {
174
175 int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
176 access_flags.is_interface(),
177 !host_klass.is_null());
178
179 // Allocation
180 InstanceKlass* ik;
181 if (rt == REF_NONE) {
182 if (name == vmSymbols::java_lang_Class()) {
183 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
184 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
185 access_flags, !host_klass.is_null());
186 } else if (name == vmSymbols::java_lang_ClassLoader() ||
187 (SystemDictionary::ClassLoader_klass_loaded() &&
188 super_klass != NULL &&
189 super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
190 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
191 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
192 access_flags, !host_klass.is_null());
193 } else {
194 // normal class
195 ik = new (loader_data, size, THREAD) InstanceKlass(
196 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
197 access_flags, !host_klass.is_null());
198 }
199 } else {
200 // reference klass
201 ik = new (loader_data, size, THREAD) InstanceRefKlass(
202 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
203 access_flags, !host_klass.is_null());
204 }
205
206 return ik;
207 }
208
209 InstanceKlass::InstanceKlass(int vtable_len,
210 int itable_len,
211 int static_field_size,
212 int nonstatic_oop_map_size,
213 ReferenceType rt,
214 AccessFlags access_flags,
215 bool is_anonymous) {
216 No_Safepoint_Verifier no_safepoint; // until k becomes parsable
217
218 int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
219 access_flags.is_interface(), is_anonymous);
220
221 // The sizes of these these three variables are used for determining the
222 // size of the instanceKlassOop. It is critical that these are set to the right
223 // sizes before the first GC, i.e., when we allocate the mirror.
224 this->set_vtable_length(vtable_len);
225 this->set_itable_length(itable_len);
226 this->set_static_field_size(static_field_size);
227 this->set_nonstatic_oop_map_size(nonstatic_oop_map_size);
228 this->set_access_flags(access_flags);
229 this->set_is_anonymous(is_anonymous);
230 assert(this->size() == size, "wrong size for object");
231
232 this->set_array_klasses(NULL);
233 this->set_methods(NULL);
234 this->set_method_ordering(NULL);
235 this->set_local_interfaces(NULL);
236 this->set_transitive_interfaces(NULL);
237 this->init_implementor();
238 this->set_fields(NULL, 0);
239 this->set_constants(NULL);
240 this->set_class_loader_data(NULL);
241 this->set_protection_domain(NULL);
242 this->set_signers(NULL);
243 this->set_source_file_name(NULL);
244 this->set_source_debug_extension(NULL, 0);
245 this->set_array_name(NULL);
246 this->set_inner_classes(NULL);
247 this->set_static_oop_field_count(0);
248 this->set_nonstatic_field_size(0);
249 this->set_is_marked_dependent(false);
250 this->set_init_state(InstanceKlass::allocated);
251 this->set_init_thread(NULL);
252 this->set_init_lock(NULL);
253 this->set_reference_type(rt);
254 this->set_oop_map_cache(NULL);
255 this->set_jni_ids(NULL);
256 this->set_osr_nmethods_head(NULL);
257 this->set_breakpoints(NULL);
258 this->init_previous_versions();
259 this->set_generic_signature(NULL);
260 this->release_set_methods_jmethod_ids(NULL);
261 this->release_set_methods_cached_itable_indices(NULL);
262 this->set_annotations(NULL);
263 this->set_jvmti_cached_class_field_map(NULL);
264 this->set_initial_method_idnum(0);
265
266 // initialize the non-header words to zero
267 intptr_t* p = (intptr_t*)this;
268 for (int index = InstanceKlass::header_size(); index < size; index++) {
269 p[index] = NULL_WORD;
270 }
271
272 // Set temporary value until parseClassFile updates it with the real instance
273 // size.
274 this->set_layout_helper(Klass::instance_layout_helper(0, true));
275 }
276
277
278 // This function deallocates the metadata and C heap pointers that the
279 // InstanceKlass points to.
280 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
281
282 // Orphan the mirror first, CMS thinks it's still live.
283 java_lang_Class::set_klass(java_mirror(), NULL);
284
285 // Need to take this class off the class loader data list.
286 loader_data->remove_class(this);
287
288 // The array_klass for this class is created later, after error handling.
289 // For class redefinition, we keep the original class so this scratch class
290 // doesn't have an array class. Either way, assert that there is nothing
291 // to deallocate.
292 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
293
294 // Release C heap allocated data that this might point to, which includes
295 // reference counting symbol names.
296 release_C_heap_structures();
297
298 Array<Method*>* ms = methods();
299 if (ms != Universe::the_empty_method_array()) {
300 for (int i = 0; i <= methods()->length() -1 ; i++) {
301 Method* method = methods()->at(i);
302 // Only want to delete methods that are not executing for RedefineClasses.
303 // The previous version will point to them so they're not totally dangling
304 assert (!method->on_stack(), "shouldn't be called with methods on stack");
305 MetadataFactory::free_metadata(loader_data, method);
306 }
307 MetadataFactory::free_array<Method*>(loader_data, methods());
308 }
309 set_methods(NULL);
310
311 if (method_ordering() != Universe::the_empty_int_array()) {
312 MetadataFactory::free_array<int>(loader_data, method_ordering());
313 }
314 set_method_ordering(NULL);
315
316 // This array is in Klass, but remove it with the InstanceKlass since
317 // this place would be the only caller and it can share memory with transitive
318 // interfaces.
319 if (secondary_supers() != Universe::the_empty_klass_array() &&
320 secondary_supers() != transitive_interfaces()) {
321 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
322 }
323 set_secondary_supers(NULL);
324
325 // Only deallocate transitive interfaces if not empty, same as super class
326 // or same as local interfaces. See code in parseClassFile.
327 Array<Klass*>* ti = transitive_interfaces();
328 if (ti != Universe::the_empty_klass_array() && ti != local_interfaces()) {
329 // check that the interfaces don't come from super class
330 Array<Klass*>* sti = (super() == NULL) ? NULL :
331 InstanceKlass::cast(super())->transitive_interfaces();
332 if (ti != sti) {
333 MetadataFactory::free_array<Klass*>(loader_data, ti);
334 }
335 }
336 set_transitive_interfaces(NULL);
337
338 // local interfaces can be empty
339 Array<Klass*>* li = local_interfaces();
340 if (li != Universe::the_empty_klass_array()) {
341 MetadataFactory::free_array<Klass*>(loader_data, li);
342 }
343 set_local_interfaces(NULL);
344
345 MetadataFactory::free_array<jushort>(loader_data, fields());
346 set_fields(NULL, 0);
347
348 // If a method from a redefined class is using this constant pool, don't
349 // delete it, yet. The new class's previous version will point to this.
350 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
351 MetadataFactory::free_metadata(loader_data, constants());
352 set_constants(NULL);
353
354 if (inner_classes() != Universe::the_empty_short_array()) {
355 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
356 }
357 set_inner_classes(NULL);
358
359 // Null out Java heap objects, although these won't be walked to keep
360 // alive once this InstanceKlass is deallocated.
361 set_protection_domain(NULL);
362 set_signers(NULL);
363 set_init_lock(NULL);
364 set_annotations(NULL);
365 }
366
367 volatile oop InstanceKlass::init_lock() const {
368 volatile oop lock = _init_lock; // read once
369 assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
370 "only fully initialized state can have a null lock");
371 return lock;
372 }
373
374 // Set the initialization lock to null so the object can be GC'ed. Any racing
375 // threads to get this lock will see a null lock and will not lock.
376 // That's okay because they all check for initialized state after getting
377 // the lock and return.
378 void InstanceKlass::fence_and_clear_init_lock() {
379 // make sure previous stores are all done, notably the init_state.
380 OrderAccess::storestore();
381 klass_oop_store(&_init_lock, NULL);
382 assert(!is_not_initialized(), "class must be initialized now");
383 }
384
385
386 bool InstanceKlass::should_be_initialized() const {
387 return !is_initialized();
388 }
389
390 klassVtable* InstanceKlass::vtable() const {
391 return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
392 }
393
394 klassItable* InstanceKlass::itable() const {
395 return new klassItable(instanceKlassHandle(this));
396 }
397
398 void InstanceKlass::eager_initialize(Thread *thread) {
399 if (!EagerInitialization) return;
400
401 if (this->is_not_initialized()) {
402 // abort if the the class has a class initializer
403 if (this->class_initializer() != NULL) return;
404
405 // abort if it is java.lang.Object (initialization is handled in genesis)
406 Klass* super = this->super();
407 if (super == NULL) return;
408
409 // abort if the super class should be initialized
410 if (!InstanceKlass::cast(super)->is_initialized()) return;
411
412 // call body to expose the this pointer
413 instanceKlassHandle this_oop(thread, this);
414 eager_initialize_impl(this_oop);
415 }
416 }
417
418
419 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
420 EXCEPTION_MARK;
421 volatile oop init_lock = this_oop->init_lock();
422 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
423
424 // abort if someone beat us to the initialization
425 if (!this_oop->is_not_initialized()) return; // note: not equivalent to is_initialized()
426
427 ClassState old_state = this_oop->init_state();
428 link_class_impl(this_oop, true, THREAD);
429 if (HAS_PENDING_EXCEPTION) {
430 CLEAR_PENDING_EXCEPTION;
431 // Abort if linking the class throws an exception.
432
433 // Use a test to avoid redundantly resetting the state if there's
434 // no change. Set_init_state() asserts that state changes make
435 // progress, whereas here we might just be spinning in place.
436 if( old_state != this_oop->_init_state )
437 this_oop->set_init_state (old_state);
438 } else {
439 // linking successfull, mark class as initialized
440 this_oop->set_init_state (fully_initialized);
441 this_oop->fence_and_clear_init_lock();
442 // trace
443 if (TraceClassInitialization) {
444 ResourceMark rm(THREAD);
445 tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
446 }
447 }
448 }
449
450
451 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
452 // process. The step comments refers to the procedure described in that section.
453 // Note: implementation moved to static method to expose the this pointer.
454 void InstanceKlass::initialize(TRAPS) {
455 if (this->should_be_initialized()) {
456 HandleMark hm(THREAD);
457 instanceKlassHandle this_oop(THREAD, this);
458 initialize_impl(this_oop, CHECK);
459 // Note: at this point the class may be initialized
460 // OR it may be in the state of being initialized
461 // in case of recursive initialization!
462 } else {
463 assert(is_initialized(), "sanity check");
464 }
465 }
466
467
468 bool InstanceKlass::verify_code(
469 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
470 // 1) Verify the bytecodes
471 Verifier::Mode mode =
472 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
473 return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
474 }
475
476
477 // Used exclusively by the shared spaces dump mechanism to prevent
478 // classes mapped into the shared regions in new VMs from appearing linked.
479
480 void InstanceKlass::unlink_class() {
481 assert(is_linked(), "must be linked");
482 _init_state = loaded;
483 }
484
485 void InstanceKlass::link_class(TRAPS) {
486 assert(is_loaded(), "must be loaded");
487 if (!is_linked()) {
488 HandleMark hm(THREAD);
489 instanceKlassHandle this_oop(THREAD, this);
490 link_class_impl(this_oop, true, CHECK);
491 }
492 }
493
494 // Called to verify that a class can link during initialization, without
495 // throwing a VerifyError.
496 bool InstanceKlass::link_class_or_fail(TRAPS) {
497 assert(is_loaded(), "must be loaded");
498 if (!is_linked()) {
499 HandleMark hm(THREAD);
500 instanceKlassHandle this_oop(THREAD, this);
501 link_class_impl(this_oop, false, CHECK_false);
502 }
503 return is_linked();
504 }
505
506 bool InstanceKlass::link_class_impl(
507 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
508 // check for error state
509 if (this_oop->is_in_error_state()) {
510 ResourceMark rm(THREAD);
511 THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
512 this_oop->external_name(), false);
513 }
514 // return if already verified
515 if (this_oop->is_linked()) {
516 return true;
517 }
518
519 // Timing
520 // timer handles recursion
521 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
522 JavaThread* jt = (JavaThread*)THREAD;
523
524 // link super class before linking this class
525 instanceKlassHandle super(THREAD, this_oop->super());
526 if (super.not_null()) {
527 if (super->is_interface()) { // check if super class is an interface
528 ResourceMark rm(THREAD);
529 Exceptions::fthrow(
530 THREAD_AND_LOCATION,
531 vmSymbols::java_lang_IncompatibleClassChangeError(),
532 "class %s has interface %s as super class",
533 this_oop->external_name(),
534 super->external_name()
535 );
536 return false;
537 }
538
539 link_class_impl(super, throw_verifyerror, CHECK_false);
540 }
541
542 // link all interfaces implemented by this class before linking this class
543 Array<Klass*>* interfaces = this_oop->local_interfaces();
544 int num_interfaces = interfaces->length();
545 for (int index = 0; index < num_interfaces; index++) {
546 HandleMark hm(THREAD);
547 instanceKlassHandle ih(THREAD, interfaces->at(index));
548 link_class_impl(ih, throw_verifyerror, CHECK_false);
549 }
550
551 // in case the class is linked in the process of linking its superclasses
552 if (this_oop->is_linked()) {
553 return true;
554 }
555
556 // trace only the link time for this klass that includes
557 // the verification time
558 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
559 ClassLoader::perf_class_link_selftime(),
560 ClassLoader::perf_classes_linked(),
561 jt->get_thread_stat()->perf_recursion_counts_addr(),
562 jt->get_thread_stat()->perf_timers_addr(),
563 PerfClassTraceTime::CLASS_LINK);
564
565 // verification & rewriting
566 {
567 volatile oop init_lock = this_oop->init_lock();
568 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
569 // rewritten will have been set if loader constraint error found
570 // on an earlier link attempt
571 // don't verify or rewrite if already rewritten
572
573 if (!this_oop->is_linked()) {
574 if (!this_oop->is_rewritten()) {
575 {
576 // Timer includes any side effects of class verification (resolution,
577 // etc), but not recursive entry into verify_code().
578 PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
579 ClassLoader::perf_class_verify_selftime(),
580 ClassLoader::perf_classes_verified(),
581 jt->get_thread_stat()->perf_recursion_counts_addr(),
582 jt->get_thread_stat()->perf_timers_addr(),
583 PerfClassTraceTime::CLASS_VERIFY);
584 bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
585 if (!verify_ok) {
586 return false;
587 }
588 }
589
590 // Just in case a side-effect of verify linked this class already
591 // (which can sometimes happen since the verifier loads classes
592 // using custom class loaders, which are free to initialize things)
593 if (this_oop->is_linked()) {
594 return true;
595 }
596
597 // also sets rewritten
598 this_oop->rewrite_class(CHECK_false);
599 }
600
601 // relocate jsrs and link methods after they are all rewritten
602 this_oop->relocate_and_link_methods(CHECK_false);
603
604 // Initialize the vtable and interface table after
605 // methods have been rewritten since rewrite may
606 // fabricate new Method*s.
607 // also does loader constraint checking
608 if (!this_oop()->is_shared()) {
609 ResourceMark rm(THREAD);
610 this_oop->vtable()->initialize_vtable(true, CHECK_false);
611 this_oop->itable()->initialize_itable(true, CHECK_false);
612 }
613 #ifdef ASSERT
614 else {
615 ResourceMark rm(THREAD);
616 this_oop->vtable()->verify(tty, true);
617 // In case itable verification is ever added.
618 // this_oop->itable()->verify(tty, true);
619 }
620 #endif
621 this_oop->set_init_state(linked);
622 if (JvmtiExport::should_post_class_prepare()) {
623 Thread *thread = THREAD;
624 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
625 JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
626 }
627 }
628 }
629 return true;
630 }
631
632
633 // Rewrite the byte codes of all of the methods of a class.
634 // The rewriter must be called exactly once. Rewriting must happen after
635 // verification but before the first method of the class is executed.
636 void InstanceKlass::rewrite_class(TRAPS) {
637 assert(is_loaded(), "must be loaded");
638 instanceKlassHandle this_oop(THREAD, this);
639 if (this_oop->is_rewritten()) {
640 assert(this_oop()->is_shared(), "rewriting an unshared class?");
641 return;
642 }
643 Rewriter::rewrite(this_oop, CHECK);
644 this_oop->set_rewritten();
645 }
646
647 // Now relocate and link method entry points after class is rewritten.
648 // This is outside is_rewritten flag. In case of an exception, it can be
649 // executed more than once.
650 void InstanceKlass::relocate_and_link_methods(TRAPS) {
651 assert(is_loaded(), "must be loaded");
652 instanceKlassHandle this_oop(THREAD, this);
653 Rewriter::relocate_and_link(this_oop, CHECK);
654 }
655
656
657 void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
658 // Make sure klass is linked (verified) before initialization
659 // A class could already be verified, since it has been reflected upon.
660 this_oop->link_class(CHECK);
661
662 DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
663
664 bool wait = false;
665
666 // refer to the JVM book page 47 for description of steps
667 // Step 1
668 {
669 volatile oop init_lock = this_oop->init_lock();
670 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
671
672 Thread *self = THREAD; // it's passed the current thread
673
674 // Step 2
675 // If we were to use wait() instead of waitInterruptibly() then
676 // we might end up throwing IE from link/symbol resolution sites
677 // that aren't expected to throw. This would wreak havoc. See 6320309.
678 while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
679 wait = true;
680 ol.waitUninterruptibly(CHECK);
681 }
682
683 // Step 3
684 if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
685 DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
686 return;
687 }
688
689 // Step 4
690 if (this_oop->is_initialized()) {
691 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
692 return;
693 }
694
695 // Step 5
696 if (this_oop->is_in_error_state()) {
697 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
698 ResourceMark rm(THREAD);
699 const char* desc = "Could not initialize class ";
700 const char* className = this_oop->external_name();
701 size_t msglen = strlen(desc) + strlen(className) + 1;
702 char* message = NEW_RESOURCE_ARRAY(char, msglen);
703 if (NULL == message) {
704 // Out of memory: can't create detailed error message
705 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
706 } else {
707 jio_snprintf(message, msglen, "%s%s", desc, className);
708 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
709 }
710 }
711
712 // Step 6
713 this_oop->set_init_state(being_initialized);
714 this_oop->set_init_thread(self);
715 }
716
717 // Step 7
718 Klass* super_klass = this_oop->super();
719 if (super_klass != NULL && !this_oop->is_interface() && super_klass->should_be_initialized()) {
720 super_klass->initialize(THREAD);
721
722 if (HAS_PENDING_EXCEPTION) {
723 Handle e(THREAD, PENDING_EXCEPTION);
724 CLEAR_PENDING_EXCEPTION;
725 {
726 EXCEPTION_MARK;
727 this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
728 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, superclass initialization error is thrown below
729 }
730 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
731 THROW_OOP(e());
732 }
733 }
734
735 if (this_oop->has_default_methods()) {
736 // Step 7.5: initialize any interfaces which have default methods
737 for (int i = 0; i < this_oop->local_interfaces()->length(); ++i) {
738 Klass* iface = this_oop->local_interfaces()->at(i);
739 InstanceKlass* ik = InstanceKlass::cast(iface);
740 if (ik->has_default_methods() && ik->should_be_initialized()) {
741 ik->initialize(THREAD);
742
743 if (HAS_PENDING_EXCEPTION) {
744 Handle e(THREAD, PENDING_EXCEPTION);
745 CLEAR_PENDING_EXCEPTION;
746 {
747 EXCEPTION_MARK;
748 // Locks object, set state, and notify all waiting threads
749 this_oop->set_initialization_state_and_notify(
750 initialization_error, THREAD);
751
752 // ignore any exception thrown, superclass initialization error is
753 // thrown below
754 CLEAR_PENDING_EXCEPTION;
755 }
756 DTRACE_CLASSINIT_PROBE_WAIT(
757 super__failed, InstanceKlass::cast(this_oop()), -1, wait);
758 THROW_OOP(e());
759 }
760 }
761 }
762 }
763
764 // Step 8
765 {
766 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
767 JavaThread* jt = (JavaThread*)THREAD;
768 DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
769 // Timer includes any side effects of class initialization (resolution,
770 // etc), but not recursive entry into call_class_initializer().
771 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
772 ClassLoader::perf_class_init_selftime(),
773 ClassLoader::perf_classes_inited(),
774 jt->get_thread_stat()->perf_recursion_counts_addr(),
775 jt->get_thread_stat()->perf_timers_addr(),
776 PerfClassTraceTime::CLASS_CLINIT);
777 this_oop->call_class_initializer(THREAD);
778 }
779
780 // Step 9
781 if (!HAS_PENDING_EXCEPTION) {
782 this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
783 { ResourceMark rm(THREAD);
784 debug_only(this_oop->vtable()->verify(tty, true);)
785 }
786 }
787 else {
788 // Step 10 and 11
789 Handle e(THREAD, PENDING_EXCEPTION);
790 CLEAR_PENDING_EXCEPTION;
791 {
792 EXCEPTION_MARK;
793 this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
794 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
795 }
796 DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
797 if (e->is_a(SystemDictionary::Error_klass())) {
798 THROW_OOP(e());
799 } else {
800 JavaCallArguments args(e);
801 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
802 vmSymbols::throwable_void_signature(),
803 &args);
804 }
805 }
806 DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
807 }
808
809
810 // Note: implementation moved to static method to expose the this pointer.
811 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
812 instanceKlassHandle kh(THREAD, this);
813 set_initialization_state_and_notify_impl(kh, state, CHECK);
814 }
815
816 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
817 volatile oop init_lock = this_oop->init_lock();
818 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
819 this_oop->set_init_state(state);
820 this_oop->fence_and_clear_init_lock();
821 ol.notify_all(CHECK);
822 }
823
824 // The embedded _implementor field can only record one implementor.
825 // When there are more than one implementors, the _implementor field
826 // is set to the interface Klass* itself. Following are the possible
827 // values for the _implementor field:
828 // NULL - no implementor
829 // implementor Klass* - one implementor
830 // self - more than one implementor
831 //
832 // The _implementor field only exists for interfaces.
833 void InstanceKlass::add_implementor(Klass* k) {
834 assert(Compile_lock->owned_by_self(), "");
835 assert(is_interface(), "not interface");
836 // Filter out my subinterfaces.
837 // (Note: Interfaces are never on the subklass list.)
838 if (InstanceKlass::cast(k)->is_interface()) return;
839
840 // Filter out subclasses whose supers already implement me.
841 // (Note: CHA must walk subclasses of direct implementors
842 // in order to locate indirect implementors.)
843 Klass* sk = InstanceKlass::cast(k)->super();
844 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
845 // We only need to check one immediate superclass, since the
846 // implements_interface query looks at transitive_interfaces.
847 // Any supers of the super have the same (or fewer) transitive_interfaces.
848 return;
849
850 Klass* ik = implementor();
851 if (ik == NULL) {
852 set_implementor(k);
853 } else if (ik != this) {
854 // There is already an implementor. Use itself as an indicator of
855 // more than one implementors.
856 set_implementor(this);
857 }
858
859 // The implementor also implements the transitive_interfaces
860 for (int index = 0; index < local_interfaces()->length(); index++) {
861 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
862 }
863 }
864
865 void InstanceKlass::init_implementor() {
866 if (is_interface()) {
867 set_implementor(NULL);
868 }
869 }
870
871
872 void InstanceKlass::process_interfaces(Thread *thread) {
873 // link this class into the implementors list of every interface it implements
874 Klass* this_as_klass_oop = this;
875 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
876 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
877 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
878 assert(interf->is_interface(), "expected interface");
879 interf->add_implementor(this_as_klass_oop);
880 }
881 }
882
883 bool InstanceKlass::can_be_primary_super_slow() const {
884 if (is_interface())
885 return false;
886 else
887 return Klass::can_be_primary_super_slow();
888 }
889
890 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
891 // The secondaries are the implemented interfaces.
892 InstanceKlass* ik = InstanceKlass::cast(this);
893 Array<Klass*>* interfaces = ik->transitive_interfaces();
894 int num_secondaries = num_extra_slots + interfaces->length();
895 if (num_secondaries == 0) {
896 // Must share this for correct bootstrapping!
897 set_secondary_supers(Universe::the_empty_klass_array());
898 return NULL;
899 } else if (num_extra_slots == 0) {
900 // The secondary super list is exactly the same as the transitive interfaces.
901 // Redefine classes has to be careful not to delete this!
902 set_secondary_supers(interfaces);
903 return NULL;
904 } else {
905 // Copy transitive interfaces to a temporary growable array to be constructed
906 // into the secondary super list with extra slots.
907 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
908 for (int i = 0; i < interfaces->length(); i++) {
909 secondaries->push(interfaces->at(i));
910 }
911 return secondaries;
912 }
913 }
914
915 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
916 if (k->is_interface()) {
917 return implements_interface(k);
918 } else {
919 return Klass::compute_is_subtype_of(k);
920 }
921 }
922
923 bool InstanceKlass::implements_interface(Klass* k) const {
924 if (this == k) return true;
925 assert(k->is_interface(), "should be an interface class");
926 for (int i = 0; i < transitive_interfaces()->length(); i++) {
927 if (transitive_interfaces()->at(i) == k) {
928 return true;
929 }
930 }
931 return false;
932 }
933
934 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
935 if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
936 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
937 report_java_out_of_memory("Requested array size exceeds VM limit");
938 JvmtiExport::post_array_size_exhausted();
939 THROW_OOP_0(Universe::out_of_memory_error_array_size());
940 }
941 int size = objArrayOopDesc::object_size(length);
942 Klass* ak = array_klass(n, CHECK_NULL);
943 KlassHandle h_ak (THREAD, ak);
944 objArrayOop o =
945 (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
946 return o;
947 }
948
949 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
950 if (TraceFinalizerRegistration) {
951 tty->print("Registered ");
952 i->print_value_on(tty);
953 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
954 }
955 instanceHandle h_i(THREAD, i);
956 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
957 JavaValue result(T_VOID);
958 JavaCallArguments args(h_i);
959 methodHandle mh (THREAD, Universe::finalizer_register_method());
960 JavaCalls::call(&result, mh, &args, CHECK_NULL);
961 return h_i();
962 }
963
964 instanceOop InstanceKlass::allocate_instance(TRAPS) {
965 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
966 int size = size_helper(); // Query before forming handle.
967
968 KlassHandle h_k(THREAD, this);
969
970 instanceOop i;
971
972 i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
973 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
974 i = register_finalizer(i, CHECK_NULL);
975 }
976 return i;
977 }
978
979 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
980 if (is_interface() || is_abstract()) {
981 ResourceMark rm(THREAD);
982 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
983 : vmSymbols::java_lang_InstantiationException(), external_name());
984 }
985 if (this == SystemDictionary::Class_klass()) {
986 ResourceMark rm(THREAD);
987 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
988 : vmSymbols::java_lang_IllegalAccessException(), external_name());
989 }
990 }
991
992 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
993 instanceKlassHandle this_oop(THREAD, this);
994 return array_klass_impl(this_oop, or_null, n, THREAD);
995 }
996
997 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
998 if (this_oop->array_klasses() == NULL) {
999 if (or_null) return NULL;
1000
1001 ResourceMark rm;
1002 JavaThread *jt = (JavaThread *)THREAD;
1003 {
1004 // Atomic creation of array_klasses
1005 MutexLocker mc(Compile_lock, THREAD); // for vtables
1006 MutexLocker ma(MultiArray_lock, THREAD);
1007
1008 // Check if update has already taken place
1009 if (this_oop->array_klasses() == NULL) {
1010 Klass* k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
1011 this_oop->set_array_klasses(k);
1012 }
1013 }
1014 }
1015 // _this will always be set at this point
1016 ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
1017 if (or_null) {
1018 return oak->array_klass_or_null(n);
1019 }
1020 return oak->array_klass(n, CHECK_NULL);
1021 }
1022
1023 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1024 return array_klass_impl(or_null, 1, THREAD);
1025 }
1026
1027 void InstanceKlass::call_class_initializer(TRAPS) {
1028 instanceKlassHandle ik (THREAD, this);
1029 call_class_initializer_impl(ik, THREAD);
1030 }
1031
1032 static int call_class_initializer_impl_counter = 0; // for debugging
1033
1034 Method* InstanceKlass::class_initializer() {
1035 Method* clinit = find_method(
1036 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1037 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1038 return clinit;
1039 }
1040 return NULL;
1041 }
1042
1043 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
1044 if (ReplayCompiles &&
1045 (ReplaySuppressInitializers == 1 ||
1046 ReplaySuppressInitializers >= 2 && this_oop->class_loader() != NULL)) {
1047 // Hide the existence of the initializer for the purpose of replaying the compile
1048 return;
1049 }
1050
1051 methodHandle h_method(THREAD, this_oop->class_initializer());
1052 assert(!this_oop->is_initialized(), "we cannot initialize twice");
1053 if (TraceClassInitialization) {
1054 tty->print("%d Initializing ", call_class_initializer_impl_counter++);
1055 this_oop->name()->print_value();
1056 tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
1057 }
1058 if (h_method() != NULL) {
1059 JavaCallArguments args; // No arguments
1060 JavaValue result(T_VOID);
1061 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1062 }
1063 }
1064
1065
1066 void InstanceKlass::mask_for(methodHandle method, int bci,
1067 InterpreterOopMap* entry_for) {
1068 // Dirty read, then double-check under a lock.
1069 if (_oop_map_cache == NULL) {
1070 // Otherwise, allocate a new one.
1071 MutexLocker x(OopMapCacheAlloc_lock);
1072 // First time use. Allocate a cache in C heap
1073 if (_oop_map_cache == NULL) {
1074 _oop_map_cache = new OopMapCache();
1075 }
1076 }
1077 // _oop_map_cache is constant after init; lookup below does is own locking.
1078 _oop_map_cache->lookup(method, bci, entry_for);
1079 }
1080
1081
1082 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1083 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1084 Symbol* f_name = fs.name();
1085 Symbol* f_sig = fs.signature();
1086 if (f_name == name && f_sig == sig) {
1087 fd->initialize(const_cast<InstanceKlass*>(this), fs.index());
1088 return true;
1089 }
1090 }
1091 return false;
1092 }
1093
1094
1095 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1096 const int n = local_interfaces()->length();
1097 for (int i = 0; i < n; i++) {
1098 Klass* intf1 = local_interfaces()->at(i);
1099 assert(intf1->is_interface(), "just checking type");
1100 // search for field in current interface
1101 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1102 assert(fd->is_static(), "interface field must be static");
1103 return intf1;
1104 }
1105 // search for field in direct superinterfaces
1106 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1107 if (intf2 != NULL) return intf2;
1108 }
1109 // otherwise field lookup fails
1110 return NULL;
1111 }
1112
1113
1114 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1115 // search order according to newest JVM spec (5.4.3.2, p.167).
1116 // 1) search for field in current klass
1117 if (find_local_field(name, sig, fd)) {
1118 return const_cast<InstanceKlass*>(this);
1119 }
1120 // 2) search for field recursively in direct superinterfaces
1121 { Klass* intf = find_interface_field(name, sig, fd);
1122 if (intf != NULL) return intf;
1123 }
1124 // 3) apply field lookup recursively if superclass exists
1125 { Klass* supr = super();
1126 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1127 }
1128 // 4) otherwise field lookup fails
1129 return NULL;
1130 }
1131
1132
1133 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1134 // search order according to newest JVM spec (5.4.3.2, p.167).
1135 // 1) search for field in current klass
1136 if (find_local_field(name, sig, fd)) {
1137 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1138 }
1139 // 2) search for field recursively in direct superinterfaces
1140 if (is_static) {
1141 Klass* intf = find_interface_field(name, sig, fd);
1142 if (intf != NULL) return intf;
1143 }
1144 // 3) apply field lookup recursively if superclass exists
1145 { Klass* supr = super();
1146 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1147 }
1148 // 4) otherwise field lookup fails
1149 return NULL;
1150 }
1151
1152
1153 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1154 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1155 if (fs.offset() == offset) {
1156 fd->initialize(const_cast<InstanceKlass*>(this), fs.index());
1157 if (fd->is_static() == is_static) return true;
1158 }
1159 }
1160 return false;
1161 }
1162
1163
1164 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1165 Klass* klass = const_cast<InstanceKlass*>(this);
1166 while (klass != NULL) {
1167 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1168 return true;
1169 }
1170 klass = klass->super();
1171 }
1172 return false;
1173 }
1174
1175
1176 void InstanceKlass::methods_do(void f(Method* method)) {
1177 int len = methods()->length();
1178 for (int index = 0; index < len; index++) {
1179 Method* m = methods()->at(index);
1180 assert(m->is_method(), "must be method");
1181 f(m);
1182 }
1183 }
1184
1185
1186 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1187 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1188 if (fs.access_flags().is_static()) {
1189 fieldDescriptor fd;
1190 fd.initialize(this, fs.index());
1191 cl->do_field(&fd);
1192 }
1193 }
1194 }
1195
1196
1197 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
1198 instanceKlassHandle h_this(THREAD, this);
1199 do_local_static_fields_impl(h_this, f, CHECK);
1200 }
1201
1202
1203 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
1204 for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
1205 if (fs.access_flags().is_static()) {
1206 fieldDescriptor fd;
1207 fd.initialize(this_oop(), fs.index());
1208 f(&fd, CHECK);
1209 }
1210 }
1211 }
1212
1213
1214 static int compare_fields_by_offset(int* a, int* b) {
1215 return a[0] - b[0];
1216 }
1217
1218 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1219 InstanceKlass* super = superklass();
1220 if (super != NULL) {
1221 super->do_nonstatic_fields(cl);
1222 }
1223 fieldDescriptor fd;
1224 int length = java_fields_count();
1225 // In DebugInfo nonstatic fields are sorted by offset.
1226 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1227 int j = 0;
1228 for (int i = 0; i < length; i += 1) {
1229 fd.initialize(this, i);
1230 if (!fd.is_static()) {
1231 fields_sorted[j + 0] = fd.offset();
1232 fields_sorted[j + 1] = i;
1233 j += 2;
1234 }
1235 }
1236 if (j > 0) {
1237 length = j;
1238 // _sort_Fn is defined in growableArray.hpp.
1239 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1240 for (int i = 0; i < length; i += 2) {
1241 fd.initialize(this, fields_sorted[i + 1]);
1242 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1243 cl->do_field(&fd);
1244 }
1245 }
1246 FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
1247 }
1248
1249
1250 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1251 if (array_klasses() != NULL)
1252 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1253 }
1254
1255 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1256 if (array_klasses() != NULL)
1257 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1258 }
1259
1260
1261 void InstanceKlass::with_array_klasses_do(void f(Klass* k)) {
1262 f(this);
1263 array_klasses_do(f);
1264 }
1265
1266 #ifdef ASSERT
1267 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
1268 int len = methods->length();
1269 for (int index = 0; index < len; index++) {
1270 Method* m = methods->at(index);
1271 assert(m->is_method(), "must be method");
1272 if (m->signature() == signature && m->name() == name) {
1273 return index;
1274 }
1275 }
1276 return -1;
1277 }
1278 #endif
1279
1280 static int binary_search(Array<Method*>* methods, Symbol* name) {
1281 int len = methods->length();
1282 // methods are sorted, so do binary search
1283 int l = 0;
1284 int h = len - 1;
1285 while (l <= h) {
1286 int mid = (l + h) >> 1;
1287 Method* m = methods->at(mid);
1288 assert(m->is_method(), "must be method");
1289 int res = m->name()->fast_compare(name);
1290 if (res == 0) {
1291 return mid;
1292 } else if (res < 0) {
1293 l = mid + 1;
1294 } else {
1295 h = mid - 1;
1296 }
1297 }
1298 return -1;
1299 }
1300
1301 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
1302 return InstanceKlass::find_method(methods(), name, signature);
1303 }
1304
1305 Method* InstanceKlass::find_method(
1306 Array<Method*>* methods, Symbol* name, Symbol* signature) {
1307 int hit = binary_search(methods, name);
1308 if (hit != -1) {
1309 Method* m = methods->at(hit);
1310 // Do linear search to find matching signature. First, quick check
1311 // for common case
1312 if (m->signature() == signature) return m;
1313 // search downwards through overloaded methods
1314 int i;
1315 for (i = hit - 1; i >= 0; --i) {
1316 Method* m = methods->at(i);
1317 assert(m->is_method(), "must be method");
1318 if (m->name() != name) break;
1319 if (m->signature() == signature) return m;
1320 }
1321 // search upwards
1322 for (i = hit + 1; i < methods->length(); ++i) {
1323 Method* m = methods->at(i);
1324 assert(m->is_method(), "must be method");
1325 if (m->name() != name) break;
1326 if (m->signature() == signature) return m;
1327 }
1328 // not found
1329 #ifdef ASSERT
1330 int index = linear_search(methods, name, signature);
1331 assert(index == -1, err_msg("binary search should have found entry %d", index));
1332 #endif
1333 }
1334 return NULL;
1335 }
1336
1337 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
1338 return find_method_by_name(methods(), name, end);
1339 }
1340
1341 int InstanceKlass::find_method_by_name(
1342 Array<Method*>* methods, Symbol* name, int* end_ptr) {
1343 assert(end_ptr != NULL, "just checking");
1344 int start = binary_search(methods, name);
1345 int end = start + 1;
1346 if (start != -1) {
1347 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1348 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1349 *end_ptr = end;
1350 return start;
1351 }
1352 return -1;
1353 }
1354
1355 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
1356 Klass* klass = const_cast<InstanceKlass*>(this);
1357 while (klass != NULL) {
1358 Method* method = InstanceKlass::cast(klass)->find_method(name, signature);
1359 if (method != NULL) return method;
1360 klass = InstanceKlass::cast(klass)->super();
1361 }
1362 return NULL;
1363 }
1364
1365 // lookup a method in all the interfaces that this class implements
1366 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1367 Symbol* signature) const {
1368 Array<Klass*>* all_ifs = transitive_interfaces();
1369 int num_ifs = all_ifs->length();
1370 InstanceKlass *ik = NULL;
1371 for (int i = 0; i < num_ifs; i++) {
1372 ik = InstanceKlass::cast(all_ifs->at(i));
1373 Method* m = ik->lookup_method(name, signature);
1374 if (m != NULL) {
1375 return m;
1376 }
1377 }
1378 return NULL;
1379 }
1380
1381 /* jni_id_for_impl for jfieldIds only */
1382 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
1383 MutexLocker ml(JfieldIdCreation_lock);
1384 // Retry lookup after we got the lock
1385 JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
1386 if (probe == NULL) {
1387 // Slow case, allocate new static field identifier
1388 probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
1389 this_oop->set_jni_ids(probe);
1390 }
1391 return probe;
1392 }
1393
1394
1395 /* jni_id_for for jfieldIds only */
1396 JNIid* InstanceKlass::jni_id_for(int offset) {
1397 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1398 if (probe == NULL) {
1399 probe = jni_id_for_impl(this, offset);
1400 }
1401 return probe;
1402 }
1403
1404 u2 InstanceKlass::enclosing_method_data(int offset) {
1405 Array<jushort>* inner_class_list = inner_classes();
1406 if (inner_class_list == NULL) {
1407 return 0;
1408 }
1409 int length = inner_class_list->length();
1410 if (length % inner_class_next_offset == 0) {
1411 return 0;
1412 } else {
1413 int index = length - enclosing_method_attribute_size;
1414 assert(offset < enclosing_method_attribute_size, "invalid offset");
1415 return inner_class_list->at(index + offset);
1416 }
1417 }
1418
1419 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1420 u2 method_index) {
1421 Array<jushort>* inner_class_list = inner_classes();
1422 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1423 int length = inner_class_list->length();
1424 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1425 int index = length - enclosing_method_attribute_size;
1426 inner_class_list->at_put(
1427 index + enclosing_method_class_index_offset, class_index);
1428 inner_class_list->at_put(
1429 index + enclosing_method_method_index_offset, method_index);
1430 }
1431 }
1432
1433 // Lookup or create a jmethodID.
1434 // This code is called by the VMThread and JavaThreads so the
1435 // locking has to be done very carefully to avoid deadlocks
1436 // and/or other cache consistency problems.
1437 //
1438 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1439 size_t idnum = (size_t)method_h->method_idnum();
1440 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1441 size_t length = 0;
1442 jmethodID id = NULL;
1443
1444 // We use a double-check locking idiom here because this cache is
1445 // performance sensitive. In the normal system, this cache only
1446 // transitions from NULL to non-NULL which is safe because we use
1447 // release_set_methods_jmethod_ids() to advertise the new cache.
1448 // A partially constructed cache should never be seen by a racing
1449 // thread. We also use release_store_ptr() to save a new jmethodID
1450 // in the cache so a partially constructed jmethodID should never be
1451 // seen either. Cache reads of existing jmethodIDs proceed without a
1452 // lock, but cache writes of a new jmethodID requires uniqueness and
1453 // creation of the cache itself requires no leaks so a lock is
1454 // generally acquired in those two cases.
1455 //
1456 // If the RedefineClasses() API has been used, then this cache can
1457 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1458 // Cache creation requires no leaks and we require safety between all
1459 // cache accesses and freeing of the old cache so a lock is generally
1460 // acquired when the RedefineClasses() API has been used.
1461
1462 if (jmeths != NULL) {
1463 // the cache already exists
1464 if (!ik_h->idnum_can_increment()) {
1465 // the cache can't grow so we can just get the current values
1466 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1467 } else {
1468 // cache can grow so we have to be more careful
1469 if (Threads::number_of_threads() == 0 ||
1470 SafepointSynchronize::is_at_safepoint()) {
1471 // we're single threaded or at a safepoint - no locking needed
1472 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1473 } else {
1474 MutexLocker ml(JmethodIdCreation_lock);
1475 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1476 }
1477 }
1478 }
1479 // implied else:
1480 // we need to allocate a cache so default length and id values are good
1481
1482 if (jmeths == NULL || // no cache yet
1483 length <= idnum || // cache is too short
1484 id == NULL) { // cache doesn't contain entry
1485
1486 // This function can be called by the VMThread so we have to do all
1487 // things that might block on a safepoint before grabbing the lock.
1488 // Otherwise, we can deadlock with the VMThread or have a cache
1489 // consistency issue. These vars keep track of what we might have
1490 // to free after the lock is dropped.
1491 jmethodID to_dealloc_id = NULL;
1492 jmethodID* to_dealloc_jmeths = NULL;
1493
1494 // may not allocate new_jmeths or use it if we allocate it
1495 jmethodID* new_jmeths = NULL;
1496 if (length <= idnum) {
1497 // allocate a new cache that might be used
1498 size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1499 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1500 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1501 // cache size is stored in element[0], other elements offset by one
1502 new_jmeths[0] = (jmethodID)size;
1503 }
1504
1505 // allocate a new jmethodID that might be used
1506 jmethodID new_id = NULL;
1507 if (method_h->is_old() && !method_h->is_obsolete()) {
1508 // The method passed in is old (but not obsolete), we need to use the current version
1509 Method* current_method = ik_h->method_with_idnum((int)idnum);
1510 assert(current_method != NULL, "old and but not obsolete, so should exist");
1511 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
1512 } else {
1513 // It is the current version of the method or an obsolete method,
1514 // use the version passed in
1515 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
1516 }
1517
1518 if (Threads::number_of_threads() == 0 ||
1519 SafepointSynchronize::is_at_safepoint()) {
1520 // we're single threaded or at a safepoint - no locking needed
1521 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1522 &to_dealloc_id, &to_dealloc_jmeths);
1523 } else {
1524 MutexLocker ml(JmethodIdCreation_lock);
1525 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1526 &to_dealloc_id, &to_dealloc_jmeths);
1527 }
1528
1529 // The lock has been dropped so we can free resources.
1530 // Free up either the old cache or the new cache if we allocated one.
1531 if (to_dealloc_jmeths != NULL) {
1532 FreeHeap(to_dealloc_jmeths);
1533 }
1534 // free up the new ID since it wasn't needed
1535 if (to_dealloc_id != NULL) {
1536 Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
1537 }
1538 }
1539 return id;
1540 }
1541
1542
1543 // Common code to fetch the jmethodID from the cache or update the
1544 // cache with the new jmethodID. This function should never do anything
1545 // that causes the caller to go to a safepoint or we can deadlock with
1546 // the VMThread or have cache consistency issues.
1547 //
1548 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1549 instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1550 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1551 jmethodID** to_dealloc_jmeths_p) {
1552 assert(new_id != NULL, "sanity check");
1553 assert(to_dealloc_id_p != NULL, "sanity check");
1554 assert(to_dealloc_jmeths_p != NULL, "sanity check");
1555 assert(Threads::number_of_threads() == 0 ||
1556 SafepointSynchronize::is_at_safepoint() ||
1557 JmethodIdCreation_lock->owned_by_self(), "sanity check");
1558
1559 // reacquire the cache - we are locked, single threaded or at a safepoint
1560 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1561 jmethodID id = NULL;
1562 size_t length = 0;
1563
1564 if (jmeths == NULL || // no cache yet
1565 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
1566 if (jmeths != NULL) {
1567 // copy any existing entries from the old cache
1568 for (size_t index = 0; index < length; index++) {
1569 new_jmeths[index+1] = jmeths[index+1];
1570 }
1571 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
1572 }
1573 ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1574 } else {
1575 // fetch jmethodID (if any) from the existing cache
1576 id = jmeths[idnum+1];
1577 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
1578 }
1579 if (id == NULL) {
1580 // No matching jmethodID in the existing cache or we have a new
1581 // cache or we just grew the cache. This cache write is done here
1582 // by the first thread to win the foot race because a jmethodID
1583 // needs to be unique once it is generally available.
1584 id = new_id;
1585
1586 // The jmethodID cache can be read while unlocked so we have to
1587 // make sure the new jmethodID is complete before installing it
1588 // in the cache.
1589 OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1590 } else {
1591 *to_dealloc_id_p = new_id; // save new id for later delete
1592 }
1593 return id;
1594 }
1595
1596
1597 // Common code to get the jmethodID cache length and the jmethodID
1598 // value at index idnum if there is one.
1599 //
1600 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1601 size_t idnum, size_t *length_p, jmethodID* id_p) {
1602 assert(cache != NULL, "sanity check");
1603 assert(length_p != NULL, "sanity check");
1604 assert(id_p != NULL, "sanity check");
1605
1606 // cache size is stored in element[0], other elements offset by one
1607 *length_p = (size_t)cache[0];
1608 if (*length_p <= idnum) { // cache is too short
1609 *id_p = NULL;
1610 } else {
1611 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
1612 }
1613 }
1614
1615
1616 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
1617 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1618 size_t idnum = (size_t)method->method_idnum();
1619 jmethodID* jmeths = methods_jmethod_ids_acquire();
1620 size_t length; // length assigned as debugging crumb
1621 jmethodID id = NULL;
1622 if (jmeths != NULL && // If there is a cache
1623 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
1624 id = jmeths[idnum+1]; // Look up the id (may be NULL)
1625 }
1626 return id;
1627 }
1628
1629
1630 // Cache an itable index
1631 void InstanceKlass::set_cached_itable_index(size_t idnum, int index) {
1632 int* indices = methods_cached_itable_indices_acquire();
1633 int* to_dealloc_indices = NULL;
1634
1635 // We use a double-check locking idiom here because this cache is
1636 // performance sensitive. In the normal system, this cache only
1637 // transitions from NULL to non-NULL which is safe because we use
1638 // release_set_methods_cached_itable_indices() to advertise the
1639 // new cache. A partially constructed cache should never be seen
1640 // by a racing thread. Cache reads and writes proceed without a
1641 // lock, but creation of the cache itself requires no leaks so a
1642 // lock is generally acquired in that case.
1643 //
1644 // If the RedefineClasses() API has been used, then this cache can
1645 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1646 // Cache creation requires no leaks and we require safety between all
1647 // cache accesses and freeing of the old cache so a lock is generally
1648 // acquired when the RedefineClasses() API has been used.
1649
1650 if (indices == NULL || idnum_can_increment()) {
1651 // we need a cache or the cache can grow
1652 MutexLocker ml(JNICachedItableIndex_lock);
1653 // reacquire the cache to see if another thread already did the work
1654 indices = methods_cached_itable_indices_acquire();
1655 size_t length = 0;
1656 // cache size is stored in element[0], other elements offset by one
1657 if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
1658 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1659 int* new_indices = NEW_C_HEAP_ARRAY(int, size+1, mtClass);
1660 new_indices[0] = (int)size;
1661 // copy any existing entries
1662 size_t i;
1663 for (i = 0; i < length; i++) {
1664 new_indices[i+1] = indices[i+1];
1665 }
1666 // Set all the rest to -1
1667 for (i = length; i < size; i++) {
1668 new_indices[i+1] = -1;
1669 }
1670 if (indices != NULL) {
1671 // We have an old cache to delete so save it for after we
1672 // drop the lock.
1673 to_dealloc_indices = indices;
1674 }
1675 release_set_methods_cached_itable_indices(indices = new_indices);
1676 }
1677
1678 if (idnum_can_increment()) {
1679 // this cache can grow so we have to write to it safely
1680 indices[idnum+1] = index;
1681 }
1682 } else {
1683 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
1684 }
1685
1686 if (!idnum_can_increment()) {
1687 // The cache cannot grow and this JNI itable index value does not
1688 // have to be unique like a jmethodID. If there is a race to set it,
1689 // it doesn't matter.
1690 indices[idnum+1] = index;
1691 }
1692
1693 if (to_dealloc_indices != NULL) {
1694 // we allocated a new cache so free the old one
1695 FreeHeap(to_dealloc_indices);
1696 }
1697 }
1698
1699
1700 // Retrieve a cached itable index
1701 int InstanceKlass::cached_itable_index(size_t idnum) {
1702 int* indices = methods_cached_itable_indices_acquire();
1703 if (indices != NULL && ((size_t)indices[0]) > idnum) {
1704 // indices exist and are long enough, retrieve possible cached
1705 return indices[idnum+1];
1706 }
1707 return -1;
1708 }
1709
1710
1711 //
1712 // Walk the list of dependent nmethods searching for nmethods which
1713 // are dependent on the changes that were passed in and mark them for
1714 // deoptimization. Returns the number of nmethods found.
1715 //
1716 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
1717 assert_locked_or_safepoint(CodeCache_lock);
1718 int found = 0;
1719 nmethodBucket* b = _dependencies;
1720 while (b != NULL) {
1721 nmethod* nm = b->get_nmethod();
1722 // since dependencies aren't removed until an nmethod becomes a zombie,
1723 // the dependency list may contain nmethods which aren't alive.
1724 if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1725 if (TraceDependencies) {
1726 ResourceMark rm;
1727 tty->print_cr("Marked for deoptimization");
1728 tty->print_cr(" context = %s", this->external_name());
1729 changes.print();
1730 nm->print();
1731 nm->print_dependencies();
1732 }
1733 nm->mark_for_deoptimization();
1734 found++;
1735 }
1736 b = b->next();
1737 }
1738 return found;
1739 }
1740
1741
1742 //
1743 // Add an nmethodBucket to the list of dependencies for this nmethod.
1744 // It's possible that an nmethod has multiple dependencies on this klass
1745 // so a count is kept for each bucket to guarantee that creation and
1746 // deletion of dependencies is consistent.
1747 //
1748 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1749 assert_locked_or_safepoint(CodeCache_lock);
1750 nmethodBucket* b = _dependencies;
1751 nmethodBucket* last = NULL;
1752 while (b != NULL) {
1753 if (nm == b->get_nmethod()) {
1754 b->increment();
1755 return;
1756 }
1757 b = b->next();
1758 }
1759 _dependencies = new nmethodBucket(nm, _dependencies);
1760 }
1761
1762
1763 //
1764 // Decrement count of the nmethod in the dependency list and remove
1765 // the bucket competely when the count goes to 0. This method must
1766 // find a corresponding bucket otherwise there's a bug in the
1767 // recording of dependecies.
1768 //
1769 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
1770 assert_locked_or_safepoint(CodeCache_lock);
1771 nmethodBucket* b = _dependencies;
1772 nmethodBucket* last = NULL;
1773 while (b != NULL) {
1774 if (nm == b->get_nmethod()) {
1775 if (b->decrement() == 0) {
1776 if (last == NULL) {
1777 _dependencies = b->next();
1778 } else {
1779 last->set_next(b->next());
1780 }
1781 delete b;
1782 }
1783 return;
1784 }
1785 last = b;
1786 b = b->next();
1787 }
1788 #ifdef ASSERT
1789 tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1790 nm->print();
1791 #endif // ASSERT
1792 ShouldNotReachHere();
1793 }
1794
1795
1796 #ifndef PRODUCT
1797 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1798 nmethodBucket* b = _dependencies;
1799 int idx = 0;
1800 while (b != NULL) {
1801 nmethod* nm = b->get_nmethod();
1802 tty->print("[%d] count=%d { ", idx++, b->count());
1803 if (!verbose) {
1804 nm->print_on(tty, "nmethod");
1805 tty->print_cr(" } ");
1806 } else {
1807 nm->print();
1808 nm->print_dependencies();
1809 tty->print_cr("--- } ");
1810 }
1811 b = b->next();
1812 }
1813 }
1814
1815
1816 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1817 nmethodBucket* b = _dependencies;
1818 while (b != NULL) {
1819 if (nm == b->get_nmethod()) {
1820 return true;
1821 }
1822 b = b->next();
1823 }
1824 return false;
1825 }
1826 #endif //PRODUCT
1827
1828
1829 // Garbage collection
1830
1831 void InstanceKlass::oops_do(OopClosure* cl) {
1832 Klass::oops_do(cl);
1833
1834 cl->do_oop(adr_protection_domain());
1835 cl->do_oop(adr_signers());
1836 cl->do_oop(adr_init_lock());
1837
1838 // Don't walk the arrays since they are walked from the ClassLoaderData objects.
1839 }
1840
1841 #ifdef ASSERT
1842 template <class T> void assert_is_in(T *p) {
1843 T heap_oop = oopDesc::load_heap_oop(p);
1844 if (!oopDesc::is_null(heap_oop)) {
1845 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1846 assert(Universe::heap()->is_in(o), "should be in heap");
1847 }
1848 }
1849 template <class T> void assert_is_in_closed_subset(T *p) {
1850 T heap_oop = oopDesc::load_heap_oop(p);
1851 if (!oopDesc::is_null(heap_oop)) {
1852 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1853 assert(Universe::heap()->is_in_closed_subset(o),
1854 err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
1855 }
1856 }
1857 template <class T> void assert_is_in_reserved(T *p) {
1858 T heap_oop = oopDesc::load_heap_oop(p);
1859 if (!oopDesc::is_null(heap_oop)) {
1860 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1861 assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
1862 }
1863 }
1864 template <class T> void assert_nothing(T *p) {}
1865
1866 #else
1867 template <class T> void assert_is_in(T *p) {}
1868 template <class T> void assert_is_in_closed_subset(T *p) {}
1869 template <class T> void assert_is_in_reserved(T *p) {}
1870 template <class T> void assert_nothing(T *p) {}
1871 #endif // ASSERT
1872
1873 //
1874 // Macros that iterate over areas of oops which are specialized on type of
1875 // oop pointer either narrow or wide, depending on UseCompressedOops
1876 //
1877 // Parameters are:
1878 // T - type of oop to point to (either oop or narrowOop)
1879 // start_p - starting pointer for region to iterate over
1880 // count - number of oops or narrowOops to iterate over
1881 // do_oop - action to perform on each oop (it's arbitrary C code which
1882 // makes it more efficient to put in a macro rather than making
1883 // it a template function)
1884 // assert_fn - assert function which is template function because performance
1885 // doesn't matter when enabled.
1886 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
1887 T, start_p, count, do_oop, \
1888 assert_fn) \
1889 { \
1890 T* p = (T*)(start_p); \
1891 T* const end = p + (count); \
1892 while (p < end) { \
1893 (assert_fn)(p); \
1894 do_oop; \
1895 ++p; \
1896 } \
1897 }
1898
1899 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
1900 T, start_p, count, do_oop, \
1901 assert_fn) \
1902 { \
1903 T* const start = (T*)(start_p); \
1904 T* p = start + (count); \
1905 while (start < p) { \
1906 --p; \
1907 (assert_fn)(p); \
1908 do_oop; \
1909 } \
1910 }
1911
1912 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
1913 T, start_p, count, low, high, \
1914 do_oop, assert_fn) \
1915 { \
1916 T* const l = (T*)(low); \
1917 T* const h = (T*)(high); \
1918 assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
1919 mask_bits((intptr_t)h, sizeof(T)-1) == 0, \
1920 "bounded region must be properly aligned"); \
1921 T* p = (T*)(start_p); \
1922 T* end = p + (count); \
1923 if (p < l) p = l; \
1924 if (end > h) end = h; \
1925 while (p < end) { \
1926 (assert_fn)(p); \
1927 do_oop; \
1928 ++p; \
1929 } \
1930 }
1931
1932
1933 // The following macros call specialized macros, passing either oop or
1934 // narrowOop as the specialization type. These test the UseCompressedOops
1935 // flag.
1936 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \
1937 { \
1938 /* Compute oopmap block range. The common case \
1939 is nonstatic_oop_map_size == 1. */ \
1940 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1941 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1942 if (UseCompressedOops) { \
1943 while (map < end_map) { \
1944 InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
1945 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1946 do_oop, assert_fn) \
1947 ++map; \
1948 } \
1949 } else { \
1950 while (map < end_map) { \
1951 InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
1952 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1953 do_oop, assert_fn) \
1954 ++map; \
1955 } \
1956 } \
1957 }
1958
1959 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \
1960 { \
1961 OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \
1962 OopMapBlock* map = start_map + nonstatic_oop_map_count(); \
1963 if (UseCompressedOops) { \
1964 while (start_map < map) { \
1965 --map; \
1966 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \
1967 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1968 do_oop, assert_fn) \
1969 } \
1970 } else { \
1971 while (start_map < map) { \
1972 --map; \
1973 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \
1974 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1975 do_oop, assert_fn) \
1976 } \
1977 } \
1978 }
1979
1980 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \
1981 assert_fn) \
1982 { \
1983 /* Compute oopmap block range. The common case is \
1984 nonstatic_oop_map_size == 1, so we accept the \
1985 usually non-existent extra overhead of examining \
1986 all the maps. */ \
1987 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1988 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1989 if (UseCompressedOops) { \
1990 while (map < end_map) { \
1991 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
1992 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1993 low, high, \
1994 do_oop, assert_fn) \
1995 ++map; \
1996 } \
1997 } else { \
1998 while (map < end_map) { \
1999 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
2000 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2001 low, high, \
2002 do_oop, assert_fn) \
2003 ++map; \
2004 } \
2005 } \
2006 }
2007
2008 void InstanceKlass::oop_follow_contents(oop obj) {
2009 assert(obj != NULL, "can't follow the content of NULL object");
2010 MarkSweep::follow_klass(obj->klass());
2011 InstanceKlass_OOP_MAP_ITERATE( \
2012 obj, \
2013 MarkSweep::mark_and_push(p), \
2014 assert_is_in_closed_subset)
2015 }
2016
2017 #ifndef SERIALGC
2018 void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
2019 oop obj) {
2020 assert(obj != NULL, "can't follow the content of NULL object");
2021 PSParallelCompact::follow_klass(cm, obj->klass());
2022 // Only mark the header and let the scan of the meta-data mark
2023 // everything else.
2024 InstanceKlass_OOP_MAP_ITERATE( \
2025 obj, \
2026 PSParallelCompact::mark_and_push(cm, p), \
2027 assert_is_in)
2028 }
2029 #endif // SERIALGC
2030
2031 // closure's do_metadata() method dictates whether the given closure should be
2032 // applied to the klass ptr in the object header.
2033
2034 #define if_do_metadata_checked(closure, nv_suffix) \
2035 /* Make sure the non-virtual and the virtual versions match. */ \
2036 assert(closure->do_metadata##nv_suffix() == closure->do_metadata(), \
2037 "Inconsistency in do_metadata"); \
2038 if (closure->do_metadata##nv_suffix())
2039
2040 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
2041 \
2042 int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
2043 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2044 /* header */ \
2045 if_do_metadata_checked(closure, nv_suffix) { \
2046 closure->do_klass##nv_suffix(obj->klass()); \
2047 } \
2048 InstanceKlass_OOP_MAP_ITERATE( \
2049 obj, \
2050 SpecializationStats:: \
2051 record_do_oop_call##nv_suffix(SpecializationStats::ik); \
2052 (closure)->do_oop##nv_suffix(p), \
2053 assert_is_in_closed_subset) \
2054 return size_helper(); \
2055 }
2056
2057 #ifndef SERIALGC
2058 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
2059 \
2060 int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \
2061 OopClosureType* closure) { \
2062 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
2063 /* header */ \
2064 if_do_metadata_checked(closure, nv_suffix) { \
2065 closure->do_klass##nv_suffix(obj->klass()); \
2066 } \
2067 /* instance variables */ \
2068 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2069 obj, \
2070 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
2071 (closure)->do_oop##nv_suffix(p), \
2072 assert_is_in_closed_subset) \
2073 return size_helper(); \
2074 }
2075 #endif // !SERIALGC
2076
2077 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
2078 \
2079 int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \
2080 OopClosureType* closure, \
2081 MemRegion mr) { \
2082 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2083 if_do_metadata_checked(closure, nv_suffix) { \
2084 if (mr.contains(obj)) { \
2085 closure->do_klass##nv_suffix(obj->klass()); \
2086 } \
2087 } \
2088 InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
2089 obj, mr.start(), mr.end(), \
2090 (closure)->do_oop##nv_suffix(p), \
2091 assert_is_in_closed_subset) \
2092 return size_helper(); \
2093 }
2094
2095 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2096 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2097 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2098 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2099 #ifndef SERIALGC
2100 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2101 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2102 #endif // !SERIALGC
2103
2104 int InstanceKlass::oop_adjust_pointers(oop obj) {
2105 int size = size_helper();
2106 InstanceKlass_OOP_MAP_ITERATE( \
2107 obj, \
2108 MarkSweep::adjust_pointer(p), \
2109 assert_is_in)
2110 MarkSweep::adjust_klass(obj->klass());
2111 return size;
2112 }
2113
2114 #ifndef SERIALGC
2115 void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
2116 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2117 obj, \
2118 if (PSScavenge::should_scavenge(p)) { \
2119 pm->claim_or_forward_depth(p); \
2120 }, \
2121 assert_nothing )
2122 }
2123
2124 int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
2125 int size = size_helper();
2126 InstanceKlass_OOP_MAP_ITERATE( \
2127 obj, \
2128 PSParallelCompact::adjust_pointer(p), \
2129 assert_is_in)
2130 obj->update_header(cm);
2131 return size;
2132 }
2133
2134 #endif // SERIALGC
2135
2136 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
2137 assert(is_loader_alive(is_alive), "this klass should be live");
2138 if (is_interface()) {
2139 if (ClassUnloading) {
2140 Klass* impl = implementor();
2141 if (impl != NULL) {
2142 if (!impl->is_loader_alive(is_alive)) {
2143 // remove this guy
2144 *adr_implementor() = NULL;
2145 }
2146 }
2147 }
2148 }
2149 }
2150
2151 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
2152 #ifdef COMPILER2
2153 // Currently only used by C2.
2154 for (int m = 0; m < methods()->length(); m++) {
2155 MethodData* mdo = methods()->at(m)->method_data();
2156 if (mdo != NULL) {
2157 for (ProfileData* data = mdo->first_data();
2158 mdo->is_valid(data);
2159 data = mdo->next_data(data)) {
2160 data->clean_weak_klass_links(is_alive);
2161 }
2162 }
2163 }
2164 #else
2165 #ifdef ASSERT
2166 // Verify that we haven't started to use MDOs for C1.
2167 for (int m = 0; m < methods()->length(); m++) {
2168 MethodData* mdo = methods()->at(m)->method_data();
2169 assert(mdo == NULL, "Didn't expect C1 to use MDOs");
2170 }
2171 #endif // ASSERT
2172 #endif // !COMPILER2
2173 }
2174
2175
2176 static void remove_unshareable_in_class(Klass* k) {
2177 // remove klass's unshareable info
2178 k->remove_unshareable_info();
2179 }
2180
2181 void InstanceKlass::remove_unshareable_info() {
2182 Klass::remove_unshareable_info();
2183 // Unlink the class
2184 if (is_linked()) {
2185 unlink_class();
2186 }
2187 init_implementor();
2188
2189 constants()->remove_unshareable_info();
2190
2191 for (int i = 0; i < methods()->length(); i++) {
2192 Method* m = methods()->at(i);
2193 m->remove_unshareable_info();
2194 }
2195
2196 // Need to reinstate when reading back the class.
2197 set_init_lock(NULL);
2198
2199 // do array classes also.
2200 array_klasses_do(remove_unshareable_in_class);
2201 }
2202
2203 void restore_unshareable_in_class(Klass* k, TRAPS) {
2204 k->restore_unshareable_info(CHECK);
2205 }
2206
2207 void InstanceKlass::restore_unshareable_info(TRAPS) {
2208 Klass::restore_unshareable_info(CHECK);
2209 instanceKlassHandle ik(THREAD, this);
2210
2211 Array<Method*>* methods = ik->methods();
2212 int num_methods = methods->length();
2213 for (int index2 = 0; index2 < num_methods; ++index2) {
2214 methodHandle m(THREAD, methods->at(index2));
2215 m()->link_method(m, CHECK);
2216 // restore method's vtable by calling a virtual function
2217 m->restore_vtable();
2218 }
2219 if (JvmtiExport::has_redefined_a_class()) {
2220 // Reinitialize vtable because RedefineClasses may have changed some
2221 // entries in this vtable for super classes so the CDS vtable might
2222 // point to old or obsolete entries. RedefineClasses doesn't fix up
2223 // vtables in the shared system dictionary, only the main one.
2224 // It also redefines the itable too so fix that too.
2225 ResourceMark rm(THREAD);
2226 ik->vtable()->initialize_vtable(false, CHECK);
2227 ik->itable()->initialize_itable(false, CHECK);
2228 }
2229
2230 // Allocate a simple java object for a lock.
2231 // This needs to be a java object because during class initialization
2232 // it can be held across a java call.
2233 typeArrayOop r = oopFactory::new_typeArray(T_INT, 0, CHECK);
2234 Handle h(THREAD, (oop)r);
2235 ik->set_init_lock(h());
2236
2237 // restore constant pool resolved references
2238 ik->constants()->restore_unshareable_info(CHECK);
2239
2240 ik->array_klasses_do(restore_unshareable_in_class, CHECK);
2241 }
2242
2243 static void clear_all_breakpoints(Method* m) {
2244 m->clear_all_breakpoints();
2245 }
2246
2247 void InstanceKlass::release_C_heap_structures() {
2248 // Deallocate oop map cache
2249 if (_oop_map_cache != NULL) {
2250 delete _oop_map_cache;
2251 _oop_map_cache = NULL;
2252 }
2253
2254 // Deallocate JNI identifiers for jfieldIDs
2255 JNIid::deallocate(jni_ids());
2256 set_jni_ids(NULL);
2257
2258 jmethodID* jmeths = methods_jmethod_ids_acquire();
2259 if (jmeths != (jmethodID*)NULL) {
2260 release_set_methods_jmethod_ids(NULL);
2261 FreeHeap(jmeths);
2262 }
2263
2264 int* indices = methods_cached_itable_indices_acquire();
2265 if (indices != (int*)NULL) {
2266 release_set_methods_cached_itable_indices(NULL);
2267 FreeHeap(indices);
2268 }
2269
2270 // release dependencies
2271 nmethodBucket* b = _dependencies;
2272 _dependencies = NULL;
2273 while (b != NULL) {
2274 nmethodBucket* next = b->next();
2275 delete b;
2276 b = next;
2277 }
2278
2279 // Deallocate breakpoint records
2280 if (breakpoints() != 0x0) {
2281 methods_do(clear_all_breakpoints);
2282 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2283 }
2284
2285 // deallocate information about previous versions
2286 if (_previous_versions != NULL) {
2287 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
2288 PreviousVersionNode * pv_node = _previous_versions->at(i);
2289 delete pv_node;
2290 }
2291 delete _previous_versions;
2292 _previous_versions = NULL;
2293 }
2294
2295 // deallocate the cached class file
2296 if (_cached_class_file_bytes != NULL) {
2297 os::free(_cached_class_file_bytes, mtClass);
2298 _cached_class_file_bytes = NULL;
2299 _cached_class_file_len = 0;
2300 }
2301
2302 // Decrement symbol reference counts associated with the unloaded class.
2303 if (_name != NULL) _name->decrement_refcount();
2304 // unreference array name derived from this class name (arrays of an unloaded
2305 // class can't be referenced anymore).
2306 if (_array_name != NULL) _array_name->decrement_refcount();
2307 if (_source_file_name != NULL) _source_file_name->decrement_refcount();
2308 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
2309 }
2310
2311 void InstanceKlass::set_source_file_name(Symbol* n) {
2312 _source_file_name = n;
2313 if (_source_file_name != NULL) _source_file_name->increment_refcount();
2314 }
2315
2316 void InstanceKlass::set_source_debug_extension(char* array, int length) {
2317 if (array == NULL) {
2318 _source_debug_extension = NULL;
2319 } else {
2320 // Adding one to the attribute length in order to store a null terminator
2321 // character could cause an overflow because the attribute length is
2322 // already coded with an u4 in the classfile, but in practice, it's
2323 // unlikely to happen.
2324 assert((length+1) > length, "Overflow checking");
2325 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2326 for (int i = 0; i < length; i++) {
2327 sde[i] = array[i];
2328 }
2329 sde[length] = '\0';
2330 _source_debug_extension = sde;
2331 }
2332 }
2333
2334 address InstanceKlass::static_field_addr(int offset) {
2335 return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + (intptr_t)java_mirror());
2336 }
2337
2338
2339 const char* InstanceKlass::signature_name() const {
2340 const char* src = (const char*) (name()->as_C_string());
2341 const int src_length = (int)strlen(src);
2342 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
2343 int src_index = 0;
2344 int dest_index = 0;
2345 dest[dest_index++] = 'L';
2346 while (src_index < src_length) {
2347 dest[dest_index++] = src[src_index++];
2348 }
2349 dest[dest_index++] = ';';
2350 dest[dest_index] = '\0';
2351 return dest;
2352 }
2353
2354 // different verisons of is_same_class_package
2355 bool InstanceKlass::is_same_class_package(Klass* class2) {
2356 Klass* class1 = this;
2357 oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2358 Symbol* classname1 = class1->name();
2359
2360 if (class2->oop_is_objArray()) {
2361 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2362 }
2363 oop classloader2;
2364 if (class2->oop_is_instance()) {
2365 classloader2 = InstanceKlass::cast(class2)->class_loader();
2366 } else {
2367 assert(class2->oop_is_typeArray(), "should be type array");
2368 classloader2 = NULL;
2369 }
2370 Symbol* classname2 = class2->name();
2371
2372 return InstanceKlass::is_same_class_package(classloader1, classname1,
2373 classloader2, classname2);
2374 }
2375
2376 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
2377 Klass* class1 = this;
2378 oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2379 Symbol* classname1 = class1->name();
2380
2381 return InstanceKlass::is_same_class_package(classloader1, classname1,
2382 classloader2, classname2);
2383 }
2384
2385 // return true if two classes are in the same package, classloader
2386 // and classname information is enough to determine a class's package
2387 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
2388 oop class_loader2, Symbol* class_name2) {
2389 if (class_loader1 != class_loader2) {
2390 return false;
2391 } else if (class_name1 == class_name2) {
2392 return true; // skip painful bytewise comparison
2393 } else {
2394 ResourceMark rm;
2395
2396 // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
2397 // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
2398 // Otherwise, we just compare jbyte values between the strings.
2399 const jbyte *name1 = class_name1->base();
2400 const jbyte *name2 = class_name2->base();
2401
2402 const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
2403 const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
2404
2405 if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
2406 // One of the two doesn't have a package. Only return true
2407 // if the other one also doesn't have a package.
2408 return last_slash1 == last_slash2;
2409 } else {
2410 // Skip over '['s
2411 if (*name1 == '[') {
2412 do {
2413 name1++;
2414 } while (*name1 == '[');
2415 if (*name1 != 'L') {
2416 // Something is terribly wrong. Shouldn't be here.
2417 return false;
2418 }
2419 }
2420 if (*name2 == '[') {
2421 do {
2422 name2++;
2423 } while (*name2 == '[');
2424 if (*name2 != 'L') {
2425 // Something is terribly wrong. Shouldn't be here.
2426 return false;
2427 }
2428 }
2429
2430 // Check that package part is identical
2431 int length1 = last_slash1 - name1;
2432 int length2 = last_slash2 - name2;
2433
2434 return UTF8::equal(name1, length1, name2, length2);
2435 }
2436 }
2437 }
2438
2439 // Returns true iff super_method can be overridden by a method in targetclassname
2440 // See JSL 3rd edition 8.4.6.1
2441 // Assumes name-signature match
2442 // "this" is InstanceKlass of super_method which must exist
2443 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2444 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2445 // Private methods can not be overridden
2446 if (super_method->is_private()) {
2447 return false;
2448 }
2449 // If super method is accessible, then override
2450 if ((super_method->is_protected()) ||
2451 (super_method->is_public())) {
2452 return true;
2453 }
2454 // Package-private methods are not inherited outside of package
2455 assert(super_method->is_package_private(), "must be package private");
2456 return(is_same_class_package(targetclassloader(), targetclassname));
2457 }
2458
2459 /* defined for now in jvm.cpp, for historical reasons *--
2460 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2461 Symbol*& simple_name_result, TRAPS) {
2462 ...
2463 }
2464 */
2465
2466 // tell if two classes have the same enclosing class (at package level)
2467 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2468 Klass* class2_oop, TRAPS) {
2469 if (class2_oop == class1()) return true;
2470 if (!class2_oop->oop_is_instance()) return false;
2471 instanceKlassHandle class2(THREAD, class2_oop);
2472
2473 // must be in same package before we try anything else
2474 if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2475 return false;
2476
2477 // As long as there is an outer1.getEnclosingClass,
2478 // shift the search outward.
2479 instanceKlassHandle outer1 = class1;
2480 for (;;) {
2481 // As we walk along, look for equalities between outer1 and class2.
2482 // Eventually, the walks will terminate as outer1 stops
2483 // at the top-level class around the original class.
2484 bool ignore_inner_is_member;
2485 Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2486 CHECK_false);
2487 if (next == NULL) break;
2488 if (next == class2()) return true;
2489 outer1 = instanceKlassHandle(THREAD, next);
2490 }
2491
2492 // Now do the same for class2.
2493 instanceKlassHandle outer2 = class2;
2494 for (;;) {
2495 bool ignore_inner_is_member;
2496 Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2497 CHECK_false);
2498 if (next == NULL) break;
2499 // Might as well check the new outer against all available values.
2500 if (next == class1()) return true;
2501 if (next == outer1()) return true;
2502 outer2 = instanceKlassHandle(THREAD, next);
2503 }
2504
2505 // If by this point we have not found an equality between the
2506 // two classes, we know they are in separate package members.
2507 return false;
2508 }
2509
2510
2511 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2512 jint access = access_flags().as_int();
2513
2514 // But check if it happens to be member class.
2515 instanceKlassHandle ik(THREAD, this);
2516 InnerClassesIterator iter(ik);
2517 for (; !iter.done(); iter.next()) {
2518 int ioff = iter.inner_class_info_index();
2519 // Inner class attribute can be zero, skip it.
2520 // Strange but true: JVM spec. allows null inner class refs.
2521 if (ioff == 0) continue;
2522
2523 // only look at classes that are already loaded
2524 // since we are looking for the flags for our self.
2525 Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2526 if ((ik->name() == inner_name)) {
2527 // This is really a member class.
2528 access = iter.inner_access_flags();
2529 break;
2530 }
2531 }
2532 // Remember to strip ACC_SUPER bit
2533 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2534 }
2535
2536 jint InstanceKlass::jvmti_class_status() const {
2537 jint result = 0;
2538
2539 if (is_linked()) {
2540 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2541 }
2542
2543 if (is_initialized()) {
2544 assert(is_linked(), "Class status is not consistent");
2545 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2546 }
2547 if (is_in_error_state()) {
2548 result |= JVMTI_CLASS_STATUS_ERROR;
2549 }
2550 return result;
2551 }
2552
2553 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2554 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2555 int method_table_offset_in_words = ioe->offset()/wordSize;
2556 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2557 / itableOffsetEntry::size();
2558
2559 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2560 // If the interface isn't implemented by the receiver class,
2561 // the VM should throw IncompatibleClassChangeError.
2562 if (cnt >= nof_interfaces) {
2563 THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2564 }
2565
2566 Klass* ik = ioe->interface_klass();
2567 if (ik == holder) break;
2568 }
2569
2570 itableMethodEntry* ime = ioe->first_method_entry(this);
2571 Method* m = ime[index].method();
2572 if (m == NULL) {
2573 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2574 }
2575 return m;
2576 }
2577
2578 // On-stack replacement stuff
2579 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2580 // only one compilation can be active
2581 NEEDS_CLEANUP
2582 // This is a short non-blocking critical region, so the no safepoint check is ok.
2583 OsrList_lock->lock_without_safepoint_check();
2584 assert(n->is_osr_method(), "wrong kind of nmethod");
2585 n->set_osr_link(osr_nmethods_head());
2586 set_osr_nmethods_head(n);
2587 // Raise the highest osr level if necessary
2588 if (TieredCompilation) {
2589 Method* m = n->method();
2590 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2591 }
2592 // Remember to unlock again
2593 OsrList_lock->unlock();
2594
2595 // Get rid of the osr methods for the same bci that have lower levels.
2596 if (TieredCompilation) {
2597 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2598 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2599 if (inv != NULL && inv->is_in_use()) {
2600 inv->make_not_entrant();
2601 }
2602 }
2603 }
2604 }
2605
2606
2607 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
2608 // This is a short non-blocking critical region, so the no safepoint check is ok.
2609 OsrList_lock->lock_without_safepoint_check();
2610 assert(n->is_osr_method(), "wrong kind of nmethod");
2611 nmethod* last = NULL;
2612 nmethod* cur = osr_nmethods_head();
2613 int max_level = CompLevel_none; // Find the max comp level excluding n
2614 Method* m = n->method();
2615 // Search for match
2616 while(cur != NULL && cur != n) {
2617 if (TieredCompilation) {
2618 // Find max level before n
2619 max_level = MAX2(max_level, cur->comp_level());
2620 }
2621 last = cur;
2622 cur = cur->osr_link();
2623 }
2624 nmethod* next = NULL;
2625 if (cur == n) {
2626 next = cur->osr_link();
2627 if (last == NULL) {
2628 // Remove first element
2629 set_osr_nmethods_head(next);
2630 } else {
2631 last->set_osr_link(next);
2632 }
2633 }
2634 n->set_osr_link(NULL);
2635 if (TieredCompilation) {
2636 cur = next;
2637 while (cur != NULL) {
2638 // Find max level after n
2639 max_level = MAX2(max_level, cur->comp_level());
2640 cur = cur->osr_link();
2641 }
2642 m->set_highest_osr_comp_level(max_level);
2643 }
2644 // Remember to unlock again
2645 OsrList_lock->unlock();
2646 }
2647
2648 nmethod* InstanceKlass::lookup_osr_nmethod(Method* const m, int bci, int comp_level, bool match_level) const {
2649 // This is a short non-blocking critical region, so the no safepoint check is ok.
2650 OsrList_lock->lock_without_safepoint_check();
2651 nmethod* osr = osr_nmethods_head();
2652 nmethod* best = NULL;
2653 while (osr != NULL) {
2654 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2655 // There can be a time when a c1 osr method exists but we are waiting
2656 // for a c2 version. When c2 completes its osr nmethod we will trash
2657 // the c1 version and only be able to find the c2 version. However
2658 // while we overflow in the c1 code at back branches we don't want to
2659 // try and switch to the same code as we are already running
2660
2661 if (osr->method() == m &&
2662 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2663 if (match_level) {
2664 if (osr->comp_level() == comp_level) {
2665 // Found a match - return it.
2666 OsrList_lock->unlock();
2667 return osr;
2668 }
2669 } else {
2670 if (best == NULL || (osr->comp_level() > best->comp_level())) {
2671 if (osr->comp_level() == CompLevel_highest_tier) {
2672 // Found the best possible - return it.
2673 OsrList_lock->unlock();
2674 return osr;
2675 }
2676 best = osr;
2677 }
2678 }
2679 }
2680 osr = osr->osr_link();
2681 }
2682 OsrList_lock->unlock();
2683 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2684 return best;
2685 }
2686 return NULL;
2687 }
2688
2689 // -----------------------------------------------------------------------------------------------------
2690 // Printing
2691
2692 #ifndef PRODUCT
2693
2694 #define BULLET " - "
2695
2696 static const char* state_names[] = {
2697 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2698 };
2699
2700 void InstanceKlass::print_on(outputStream* st) const {
2701 assert(is_klass(), "must be klass");
2702 Klass::print_on(st);
2703
2704 st->print(BULLET"instance size: %d", size_helper()); st->cr();
2705 st->print(BULLET"klass size: %d", size()); st->cr();
2706 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
2707 st->print(BULLET"state: "); st->print_cr(state_names[_init_state]);
2708 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
2709 st->print(BULLET"super: "); super()->print_value_on_maybe_null(st); st->cr();
2710 st->print(BULLET"sub: ");
2711 Klass* sub = subklass();
2712 int n;
2713 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2714 if (n < MaxSubklassPrintSize) {
2715 sub->print_value_on(st);
2716 st->print(" ");
2717 }
2718 }
2719 if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
2720 st->cr();
2721
2722 if (is_interface()) {
2723 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
2724 if (nof_implementors() == 1) {
2725 st->print_cr(BULLET"implementor: ");
2726 st->print(" ");
2727 implementor()->print_value_on(st);
2728 st->cr();
2729 }
2730 }
2731
2732 st->print(BULLET"arrays: "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2733 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
2734 if (Verbose) {
2735 Array<Method*>* method_array = methods();
2736 for(int i = 0; i < method_array->length(); i++) {
2737 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2738 }
2739 }
2740 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
2741 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
2742 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2743 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
2744 if (class_loader_data() != NULL) {
2745 st->print(BULLET"class loader data: ");
2746 class_loader_data()->print_value_on(st);
2747 st->cr();
2748 }
2749 st->print(BULLET"protection domain: "); ((InstanceKlass*)this)->protection_domain()->print_value_on(st); st->cr();
2750 st->print(BULLET"host class: "); host_klass()->print_value_on_maybe_null(st); st->cr();
2751 st->print(BULLET"signers: "); signers()->print_value_on(st); st->cr();
2752 st->print(BULLET"init_lock: "); ((oop)init_lock())->print_value_on(st); st->cr();
2753 if (source_file_name() != NULL) {
2754 st->print(BULLET"source file: ");
2755 source_file_name()->print_value_on(st);
2756 st->cr();
2757 }
2758 if (source_debug_extension() != NULL) {
2759 st->print(BULLET"source debug extension: ");
2760 st->print("%s", source_debug_extension());
2761 st->cr();
2762 }
2763 st->print(BULLET"annotations: "); annotations()->print_value_on(st); st->cr();
2764 {
2765 ResourceMark rm;
2766 // PreviousVersionInfo objects returned via PreviousVersionWalker
2767 // contain a GrowableArray of handles. We have to clean up the
2768 // GrowableArray _after_ the PreviousVersionWalker destructor
2769 // has destroyed the handles.
2770 {
2771 bool have_pv = false;
2772 PreviousVersionWalker pvw((InstanceKlass*)this);
2773 for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
2774 pv_info != NULL; pv_info = pvw.next_previous_version()) {
2775 if (!have_pv)
2776 st->print(BULLET"previous version: ");
2777 have_pv = true;
2778 pv_info->prev_constant_pool_handle()()->print_value_on(st);
2779 }
2780 if (have_pv) st->cr();
2781 } // pvw is cleaned up
2782 } // rm is cleaned up
2783
2784 if (generic_signature() != NULL) {
2785 st->print(BULLET"generic signature: ");
2786 generic_signature()->print_value_on(st);
2787 st->cr();
2788 }
2789 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
2790 st->print(BULLET"java mirror: "); java_mirror()->print_value_on(st); st->cr();
2791 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable()); st->cr();
2792 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
2793 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2794 FieldPrinter print_static_field(st);
2795 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2796 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2797 FieldPrinter print_nonstatic_field(st);
2798 ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
2799
2800 st->print(BULLET"non-static oop maps: ");
2801 OopMapBlock* map = start_of_nonstatic_oop_maps();
2802 OopMapBlock* end_map = map + nonstatic_oop_map_count();
2803 while (map < end_map) {
2804 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2805 map++;
2806 }
2807 st->cr();
2808 }
2809
2810 #endif //PRODUCT
2811
2812 void InstanceKlass::print_value_on(outputStream* st) const {
2813 assert(is_klass(), "must be klass");
2814 name()->print_value_on(st);
2815 }
2816
2817 #ifndef PRODUCT
2818
2819 void FieldPrinter::do_field(fieldDescriptor* fd) {
2820 _st->print(BULLET);
2821 if (_obj == NULL) {
2822 fd->print_on(_st);
2823 _st->cr();
2824 } else {
2825 fd->print_on_for(_st, _obj);
2826 _st->cr();
2827 }
2828 }
2829
2830
2831 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
2832 Klass::oop_print_on(obj, st);
2833
2834 if (this == SystemDictionary::String_klass()) {
2835 typeArrayOop value = java_lang_String::value(obj);
2836 juint offset = java_lang_String::offset(obj);
2837 juint length = java_lang_String::length(obj);
2838 if (value != NULL &&
2839 value->is_typeArray() &&
2840 offset <= (juint) value->length() &&
2841 offset + length <= (juint) value->length()) {
2842 st->print(BULLET"string: ");
2843 Handle h_obj(obj);
2844 java_lang_String::print(h_obj, st);
2845 st->cr();
2846 if (!WizardMode) return; // that is enough
2847 }
2848 }
2849
2850 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
2851 FieldPrinter print_field(st, obj);
2852 do_nonstatic_fields(&print_field);
2853
2854 if (this == SystemDictionary::Class_klass()) {
2855 st->print(BULLET"signature: ");
2856 java_lang_Class::print_signature(obj, st);
2857 st->cr();
2858 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
2859 st->print(BULLET"fake entry for mirror: ");
2860 mirrored_klass->print_value_on_maybe_null(st);
2861 st->cr();
2862 st->print(BULLET"fake entry resolved_constructor: ");
2863 Method* ctor = java_lang_Class::resolved_constructor(obj);
2864 ctor->print_value_on_maybe_null(st);
2865 Klass* array_klass = java_lang_Class::array_klass(obj);
2866 st->cr();
2867 st->print(BULLET"fake entry for array: ");
2868 array_klass->print_value_on_maybe_null(st);
2869 st->cr();
2870 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
2871 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
2872 Klass* real_klass = java_lang_Class::as_Klass(obj);
2873 if (real_klass != NULL && real_klass->oop_is_instance()) {
2874 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
2875 }
2876 } else if (this == SystemDictionary::MethodType_klass()) {
2877 st->print(BULLET"signature: ");
2878 java_lang_invoke_MethodType::print_signature(obj, st);
2879 st->cr();
2880 }
2881 }
2882
2883 #endif //PRODUCT
2884
2885 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
2886 st->print("a ");
2887 name()->print_value_on(st);
2888 obj->print_address_on(st);
2889 if (this == SystemDictionary::String_klass()
2890 && java_lang_String::value(obj) != NULL) {
2891 ResourceMark rm;
2892 int len = java_lang_String::length(obj);
2893 int plen = (len < 24 ? len : 12);
2894 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
2895 st->print(" = \"%s\"", str);
2896 if (len > plen)
2897 st->print("...[%d]", len);
2898 } else if (this == SystemDictionary::Class_klass()) {
2899 Klass* k = java_lang_Class::as_Klass(obj);
2900 st->print(" = ");
2901 if (k != NULL) {
2902 k->print_value_on(st);
2903 } else {
2904 const char* tname = type2name(java_lang_Class::primitive_type(obj));
2905 st->print("%s", tname ? tname : "type?");
2906 }
2907 } else if (this == SystemDictionary::MethodType_klass()) {
2908 st->print(" = ");
2909 java_lang_invoke_MethodType::print_signature(obj, st);
2910 } else if (java_lang_boxing_object::is_instance(obj)) {
2911 st->print(" = ");
2912 java_lang_boxing_object::print(obj, st);
2913 } else if (this == SystemDictionary::LambdaForm_klass()) {
2914 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
2915 if (vmentry != NULL) {
2916 st->print(" => ");
2917 vmentry->print_value_on(st);
2918 }
2919 } else if (this == SystemDictionary::MemberName_klass()) {
2920 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
2921 if (vmtarget != NULL) {
2922 st->print(" = ");
2923 vmtarget->print_value_on(st);
2924 } else {
2925 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
2926 st->print(".");
2927 java_lang_invoke_MemberName::name(obj)->print_value_on(st);
2928 }
2929 }
2930 }
2931
2932 const char* InstanceKlass::internal_name() const {
2933 return external_name();
2934 }
2935
2936 // Verification
2937
2938 class VerifyFieldClosure: public OopClosure {
2939 protected:
2940 template <class T> void do_oop_work(T* p) {
2941 oop obj = oopDesc::load_decode_heap_oop(p);
2942 if (!obj->is_oop_or_null()) {
2943 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
2944 Universe::print();
2945 guarantee(false, "boom");
2946 }
2947 }
2948 public:
2949 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
2950 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
2951 };
2952
2953 void InstanceKlass::verify_on(outputStream* st) {
2954 Klass::verify_on(st);
2955 Thread *thread = Thread::current();
2956
2957 #ifndef PRODUCT
2958 // Avoid redundant verifies
2959 if (_verify_count == Universe::verify_count()) return;
2960 _verify_count = Universe::verify_count();
2961 #endif
2962 // Verify that klass is present in SystemDictionary
2963 if (is_loaded() && !is_anonymous()) {
2964 Symbol* h_name = name();
2965 SystemDictionary::verify_obj_klass_present(h_name, class_loader_data());
2966 }
2967
2968 // Verify static fields
2969 VerifyFieldClosure blk;
2970
2971 // Verify vtables
2972 if (is_linked()) {
2973 ResourceMark rm(thread);
2974 // $$$ This used to be done only for m/s collections. Doing it
2975 // always seemed a valid generalization. (DLD -- 6/00)
2976 vtable()->verify(st);
2977 }
2978
2979 // Verify first subklass
2980 if (subklass_oop() != NULL) {
2981 guarantee(subklass_oop()->is_metadata(), "should be in metaspace");
2982 guarantee(subklass_oop()->is_klass(), "should be klass");
2983 }
2984
2985 // Verify siblings
2986 Klass* super = this->super();
2987 Klass* sib = next_sibling();
2988 if (sib != NULL) {
2989 if (sib == this) {
2990 fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
2991 }
2992
2993 guarantee(sib->is_metadata(), "should be in metaspace");
2994 guarantee(sib->is_klass(), "should be klass");
2995 guarantee(sib->super() == super, "siblings should have same superklass");
2996 }
2997
2998 // Verify implementor fields
2999 Klass* im = implementor();
3000 if (im != NULL) {
3001 guarantee(is_interface(), "only interfaces should have implementor set");
3002 guarantee(im->is_klass(), "should be klass");
3003 guarantee(!im->is_interface() || im == this,
3004 "implementors cannot be interfaces");
3005 }
3006
3007 // Verify local interfaces
3008 if (local_interfaces()) {
3009 Array<Klass*>* local_interfaces = this->local_interfaces();
3010 for (int j = 0; j < local_interfaces->length(); j++) {
3011 Klass* e = local_interfaces->at(j);
3012 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3013 }
3014 }
3015
3016 // Verify transitive interfaces
3017 if (transitive_interfaces() != NULL) {
3018 Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3019 for (int j = 0; j < transitive_interfaces->length(); j++) {
3020 Klass* e = transitive_interfaces->at(j);
3021 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3022 }
3023 }
3024
3025 // Verify methods
3026 if (methods() != NULL) {
3027 Array<Method*>* methods = this->methods();
3028 for (int j = 0; j < methods->length(); j++) {
3029 guarantee(methods->at(j)->is_metadata(), "should be in metaspace");
3030 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3031 }
3032 for (int j = 0; j < methods->length() - 1; j++) {
3033 Method* m1 = methods->at(j);
3034 Method* m2 = methods->at(j + 1);
3035 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3036 }
3037 }
3038
3039 // Verify method ordering
3040 if (method_ordering() != NULL) {
3041 Array<int>* method_ordering = this->method_ordering();
3042 int length = method_ordering->length();
3043 if (JvmtiExport::can_maintain_original_method_order() ||
3044 (UseSharedSpaces && length != 0)) {
3045 guarantee(length == methods()->length(), "invalid method ordering length");
3046 jlong sum = 0;
3047 for (int j = 0; j < length; j++) {
3048 int original_index = method_ordering->at(j);
3049 guarantee(original_index >= 0, "invalid method ordering index");
3050 guarantee(original_index < length, "invalid method ordering index");
3051 sum += original_index;
3052 }
3053 // Verify sum of indices 0,1,...,length-1
3054 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3055 } else {
3056 guarantee(length == 0, "invalid method ordering length");
3057 }
3058 }
3059
3060 // Verify JNI static field identifiers
3061 if (jni_ids() != NULL) {
3062 jni_ids()->verify(this);
3063 }
3064
3065 // Verify other fields
3066 if (array_klasses() != NULL) {
3067 guarantee(array_klasses()->is_metadata(), "should be in metaspace");
3068 guarantee(array_klasses()->is_klass(), "should be klass");
3069 }
3070 if (constants() != NULL) {
3071 guarantee(constants()->is_metadata(), "should be in metaspace");
3072 guarantee(constants()->is_constantPool(), "should be constant pool");
3073 }
3074 if (protection_domain() != NULL) {
3075 guarantee(protection_domain()->is_oop(), "should be oop");
3076 }
3077 if (host_klass() != NULL) {
3078 guarantee(host_klass()->is_metadata(), "should be in metaspace");
3079 guarantee(host_klass()->is_klass(), "should be klass");
3080 }
3081 if (signers() != NULL) {
3082 guarantee(signers()->is_objArray(), "should be obj array");
3083 }
3084 }
3085
3086 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3087 Klass::oop_verify_on(obj, st);
3088 VerifyFieldClosure blk;
3089 obj->oop_iterate_no_header(&blk);
3090 }
3091
3092
3093 // JNIid class for jfieldIDs only
3094 // Note to reviewers:
3095 // These JNI functions are just moved over to column 1 and not changed
3096 // in the compressed oops workspace.
3097 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3098 _holder = holder;
3099 _offset = offset;
3100 _next = next;
3101 debug_only(_is_static_field_id = false;)
3102 }
3103
3104
3105 JNIid* JNIid::find(int offset) {
3106 JNIid* current = this;
3107 while (current != NULL) {
3108 if (current->offset() == offset) return current;
3109 current = current->next();
3110 }
3111 return NULL;
3112 }
3113
3114 void JNIid::deallocate(JNIid* current) {
3115 while (current != NULL) {
3116 JNIid* next = current->next();
3117 delete current;
3118 current = next;
3119 }
3120 }
3121
3122
3123 void JNIid::verify(Klass* holder) {
3124 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3125 int end_field_offset;
3126 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3127
3128 JNIid* current = this;
3129 while (current != NULL) {
3130 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3131 #ifdef ASSERT
3132 int o = current->offset();
3133 if (current->is_static_field_id()) {
3134 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3135 }
3136 #endif
3137 current = current->next();
3138 }
3139 }
3140
3141
3142 #ifdef ASSERT
3143 void InstanceKlass::set_init_state(ClassState state) {
3144 bool good_state = is_shared() ? (_init_state <= state)
3145 : (_init_state < state);
3146 assert(good_state || state == allocated, "illegal state transition");
3147 _init_state = (u1)state;
3148 }
3149 #endif
3150
3151
3152 // RedefineClasses() support for previous versions:
3153
3154 // Purge previous versions
3155 static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
3156 if (ik->previous_versions() != NULL) {
3157 // This klass has previous versions so see what we can cleanup
3158 // while it is safe to do so.
3159
3160 int deleted_count = 0; // leave debugging breadcrumbs
3161 int live_count = 0;
3162 ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
3163 ClassLoaderData::the_null_class_loader_data() :
3164 ik->class_loader_data();
3165
3166 // RC_TRACE macro has an embedded ResourceMark
3167 RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
3168 ik->external_name(), ik->previous_versions()->length()));
3169
3170 for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
3171 // check the previous versions array
3172 PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
3173 ConstantPool* cp_ref = pv_node->prev_constant_pool();
3174 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
3175
3176 ConstantPool* pvcp = cp_ref;
3177 if (!pvcp->on_stack()) {
3178 // If the constant pool isn't on stack, none of the methods
3179 // are executing. Delete all the methods, the constant pool and
3180 // and this previous version node.
3181 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3182 if (method_refs != NULL) {
3183 for (int j = method_refs->length() - 1; j >= 0; j--) {
3184 Method* method = method_refs->at(j);
3185 assert(method != NULL, "method ref was unexpectedly cleared");
3186 method_refs->remove_at(j);
3187 // method will be freed with associated class.
3188 }
3189 }
3190 // Remove the constant pool
3191 delete pv_node;
3192 // Since we are traversing the array backwards, we don't have to
3193 // do anything special with the index.
3194 ik->previous_versions()->remove_at(i);
3195 deleted_count++;
3196 continue;
3197 } else {
3198 RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
3199 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3200 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3201 live_count++;
3202 }
3203
3204 // At least one method is live in this previous version, clean out
3205 // the others or mark them as obsolete.
3206 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3207 if (method_refs != NULL) {
3208 RC_TRACE(0x00000200, ("purge: previous methods length=%d",
3209 method_refs->length()));
3210 for (int j = method_refs->length() - 1; j >= 0; j--) {
3211 Method* method = method_refs->at(j);
3212 assert(method != NULL, "method ref was unexpectedly cleared");
3213
3214 // Remove the emcp method if it's not executing
3215 // If it's been made obsolete by a redefinition of a non-emcp
3216 // method, mark it as obsolete but leave it to clean up later.
3217 if (!method->on_stack()) {
3218 method_refs->remove_at(j);
3219 } else if (emcp_method_count == 0) {
3220 method->set_is_obsolete();
3221 } else {
3222 // RC_TRACE macro has an embedded ResourceMark
3223 RC_TRACE(0x00000200,
3224 ("purge: %s(%s): prev method @%d in version @%d is alive",
3225 method->name()->as_C_string(),
3226 method->signature()->as_C_string(), j, i));
3227 }
3228 }
3229 }
3230 }
3231 assert(ik->previous_versions()->length() == live_count, "sanity check");
3232 RC_TRACE(0x00000200,
3233 ("purge: previous version stats: live=%d, deleted=%d", live_count,
3234 deleted_count));
3235 }
3236 }
3237
3238 // External interface for use during class unloading.
3239 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
3240 // Call with >0 emcp methods since they are not currently being redefined.
3241 purge_previous_versions_internal(ik, 1);
3242 }
3243
3244
3245 // Potentially add an information node that contains pointers to the
3246 // interesting parts of the previous version of the_class.
3247 // This is also where we clean out any unused references.
3248 // Note that while we delete nodes from the _previous_versions
3249 // array, we never delete the array itself until the klass is
3250 // unloaded. The has_been_redefined() query depends on that fact.
3251 //
3252 void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
3253 BitMap* emcp_methods, int emcp_method_count) {
3254 assert(Thread::current()->is_VM_thread(),
3255 "only VMThread can add previous versions");
3256
3257 if (_previous_versions == NULL) {
3258 // This is the first previous version so make some space.
3259 // Start with 2 elements under the assumption that the class
3260 // won't be redefined much.
3261 _previous_versions = new (ResourceObj::C_HEAP, mtClass)
3262 GrowableArray<PreviousVersionNode *>(2, true);
3263 }
3264
3265 ConstantPool* cp_ref = ikh->constants();
3266
3267 // RC_TRACE macro has an embedded ResourceMark
3268 RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
3269 "on_stack=%d",
3270 ikh->external_name(), _previous_versions->length(), emcp_method_count,
3271 cp_ref->on_stack()));
3272
3273 // If the constant pool for this previous version of the class
3274 // is not marked as being on the stack, then none of the methods
3275 // in this previous version of the class are on the stack so
3276 // we don't need to create a new PreviousVersionNode. However,
3277 // we still need to examine older previous versions below.
3278 Array<Method*>* old_methods = ikh->methods();
3279
3280 if (cp_ref->on_stack()) {
3281 PreviousVersionNode * pv_node = NULL;
3282 if (emcp_method_count == 0) {
3283 // non-shared ConstantPool gets a reference
3284 pv_node = new PreviousVersionNode(cp_ref, !cp_ref->is_shared(), NULL);
3285 RC_TRACE(0x00000400,
3286 ("add: all methods are obsolete; flushing any EMCP refs"));
3287 } else {
3288 int local_count = 0;
3289 GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
3290 GrowableArray<Method*>(emcp_method_count, true);
3291 for (int i = 0; i < old_methods->length(); i++) {
3292 if (emcp_methods->at(i)) {
3293 // this old method is EMCP. Save it only if it's on the stack
3294 Method* old_method = old_methods->at(i);
3295 if (old_method->on_stack()) {
3296 method_refs->append(old_method);
3297 }
3298 if (++local_count >= emcp_method_count) {
3299 // no more EMCP methods so bail out now
3300 break;
3301 }
3302 }
3303 }
3304 // non-shared ConstantPool gets a reference
3305 pv_node = new PreviousVersionNode(cp_ref, !cp_ref->is_shared(), method_refs);
3306 }
3307 // append new previous version.
3308 _previous_versions->append(pv_node);
3309 }
3310
3311 // Since the caller is the VMThread and we are at a safepoint, this
3312 // is a good time to clear out unused references.
3313
3314 RC_TRACE(0x00000400, ("add: previous version length=%d",
3315 _previous_versions->length()));
3316
3317 // Purge previous versions not executing on the stack
3318 purge_previous_versions_internal(this, emcp_method_count);
3319
3320 int obsolete_method_count = old_methods->length() - emcp_method_count;
3321
3322 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3323 _previous_versions->length() > 0) {
3324 // We have a mix of obsolete and EMCP methods so we have to
3325 // clear out any matching EMCP method entries the hard way.
3326 int local_count = 0;
3327 for (int i = 0; i < old_methods->length(); i++) {
3328 if (!emcp_methods->at(i)) {
3329 // only obsolete methods are interesting
3330 Method* old_method = old_methods->at(i);
3331 Symbol* m_name = old_method->name();
3332 Symbol* m_signature = old_method->signature();
3333
3334 // we might not have added the last entry
3335 for (int j = _previous_versions->length() - 1; j >= 0; j--) {
3336 // check the previous versions array for non executing obsolete methods
3337 PreviousVersionNode * pv_node = _previous_versions->at(j);
3338
3339 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3340 if (method_refs == NULL) {
3341 // We have run into a PreviousVersion generation where
3342 // all methods were made obsolete during that generation's
3343 // RedefineClasses() operation. At the time of that
3344 // operation, all EMCP methods were flushed so we don't
3345 // have to go back any further.
3346 //
3347 // A NULL method_refs is different than an empty method_refs.
3348 // We cannot infer any optimizations about older generations
3349 // from an empty method_refs for the current generation.
3350 break;
3351 }
3352
3353 for (int k = method_refs->length() - 1; k >= 0; k--) {
3354 Method* method = method_refs->at(k);
3355
3356 if (!method->is_obsolete() &&
3357 method->name() == m_name &&
3358 method->signature() == m_signature) {
3359 // The current RedefineClasses() call has made all EMCP
3360 // versions of this method obsolete so mark it as obsolete
3361 // and remove the reference.
3362 RC_TRACE(0x00000400,
3363 ("add: %s(%s): flush obsolete method @%d in version @%d",
3364 m_name->as_C_string(), m_signature->as_C_string(), k, j));
3365
3366 method->set_is_obsolete();
3367 // Leave obsolete methods on the previous version list to
3368 // clean up later.
3369 break;
3370 }
3371 }
3372
3373 // The previous loop may not find a matching EMCP method, but
3374 // that doesn't mean that we can optimize and not go any
3375 // further back in the PreviousVersion generations. The EMCP
3376 // method for this generation could have already been deleted,
3377 // but there still may be an older EMCP method that has not
3378 // been deleted.
3379 }
3380
3381 if (++local_count >= obsolete_method_count) {
3382 // no more obsolete methods so bail out now
3383 break;
3384 }
3385 }
3386 }
3387 }
3388 } // end add_previous_version()
3389
3390
3391 // Determine if InstanceKlass has a previous version.
3392 bool InstanceKlass::has_previous_version() const {
3393 return (_previous_versions != NULL && _previous_versions->length() > 0);
3394 } // end has_previous_version()
3395
3396
3397 Method* InstanceKlass::method_with_idnum(int idnum) {
3398 Method* m = NULL;
3399 if (idnum < methods()->length()) {
3400 m = methods()->at(idnum);
3401 }
3402 if (m == NULL || m->method_idnum() != idnum) {
3403 for (int index = 0; index < methods()->length(); ++index) {
3404 m = methods()->at(index);
3405 if (m->method_idnum() == idnum) {
3406 return m;
3407 }
3408 }
3409 }
3410 return m;
3411 }
3412
3413
3414 // Construct a PreviousVersionNode entry for the array hung off
3415 // the InstanceKlass.
3416 PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
3417 bool prev_cp_is_weak, GrowableArray<Method*>* prev_EMCP_methods) {
3418
3419 _prev_constant_pool = prev_constant_pool;
3420 _prev_cp_is_weak = prev_cp_is_weak;
3421 _prev_EMCP_methods = prev_EMCP_methods;
3422 }
3423
3424
3425 // Destroy a PreviousVersionNode
3426 PreviousVersionNode::~PreviousVersionNode() {
3427 if (_prev_constant_pool != NULL) {
3428 _prev_constant_pool = NULL;
3429 }
3430
3431 if (_prev_EMCP_methods != NULL) {
3432 delete _prev_EMCP_methods;
3433 }
3434 }
3435
3436
3437 // Construct a PreviousVersionInfo entry
3438 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
3439 _prev_constant_pool_handle = constantPoolHandle(); // NULL handle
3440 _prev_EMCP_method_handles = NULL;
3441
3442 ConstantPool* cp = pv_node->prev_constant_pool();
3443 assert(cp != NULL, "constant pool ref was unexpectedly cleared");
3444 if (cp == NULL) {
3445 return; // robustness
3446 }
3447
3448 // make the ConstantPool* safe to return
3449 _prev_constant_pool_handle = constantPoolHandle(cp);
3450
3451 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3452 if (method_refs == NULL) {
3453 // the InstanceKlass did not have any EMCP methods
3454 return;
3455 }
3456
3457 _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
3458
3459 int n_methods = method_refs->length();
3460 for (int i = 0; i < n_methods; i++) {
3461 Method* method = method_refs->at(i);
3462 assert (method != NULL, "method has been cleared");
3463 if (method == NULL) {
3464 continue; // robustness
3465 }
3466 // make the Method* safe to return
3467 _prev_EMCP_method_handles->append(methodHandle(method));
3468 }
3469 }
3470
3471
3472 // Destroy a PreviousVersionInfo
3473 PreviousVersionInfo::~PreviousVersionInfo() {
3474 // Since _prev_EMCP_method_handles is not C-heap allocated, we
3475 // don't have to delete it.
3476 }
3477
3478
3479 // Construct a helper for walking the previous versions array
3480 PreviousVersionWalker::PreviousVersionWalker(InstanceKlass *ik) {
3481 _previous_versions = ik->previous_versions();
3482 _current_index = 0;
3483 // _hm needs no initialization
3484 _current_p = NULL;
3485 }
3486
3487
3488 // Destroy a PreviousVersionWalker
3489 PreviousVersionWalker::~PreviousVersionWalker() {
3490 // Delete the current info just in case the caller didn't walk to
3491 // the end of the previous versions list. No harm if _current_p is
3492 // already NULL.
3493 delete _current_p;
3494
3495 // When _hm is destroyed, all the Handles returned in
3496 // PreviousVersionInfo objects will be destroyed.
3497 // Also, after this destructor is finished it will be
3498 // safe to delete the GrowableArray allocated in the
3499 // PreviousVersionInfo objects.
3500 }
3501
3502
3503 // Return the interesting information for the next previous version
3504 // of the klass. Returns NULL if there are no more previous versions.
3505 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
3506 if (_previous_versions == NULL) {
3507 // no previous versions so nothing to return
3508 return NULL;
3509 }
3510
3511 delete _current_p; // cleanup the previous info for the caller
3512 _current_p = NULL; // reset to NULL so we don't delete same object twice
3513
3514 int length = _previous_versions->length();
3515
3516 while (_current_index < length) {
3517 PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
3518 PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP, mtClass)
3519 PreviousVersionInfo(pv_node);
3520
3521 constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
3522 assert (!cp_h.is_null(), "null cp found in previous version");
3523
3524 // The caller will need to delete pv_info when they are done with it.
3525 _current_p = pv_info;
3526 return pv_info;
3527 }
3528
3529 // all of the underlying nodes' info has been deleted
3530 return NULL;
3531 } // end next_previous_version()