1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/javaClasses.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/verifier.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "gc_implementation/shared/markSweep.inline.hpp"
32 #include "gc_interface/collectedHeap.inline.hpp"
33 #include "interpreter/oopMapCache.hpp"
34 #include "interpreter/rewriter.hpp"
35 #include "jvmtifiles/jvmti.h"
36 #include "memory/genOopClosures.inline.hpp"
37 #include "memory/heapInspection.hpp"
38 #include "memory/metadataFactory.hpp"
39 #include "memory/oopFactory.hpp"
40 #include "oops/fieldStreams.hpp"
41 #include "oops/instanceClassLoaderKlass.hpp"
42 #include "oops/instanceKlass.hpp"
43 #include "oops/instanceMirrorKlass.hpp"
44 #include "oops/instanceOop.hpp"
45 #include "oops/klass.inline.hpp"
46 #include "oops/method.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "oops/symbol.hpp"
49 #include "prims/jvmtiExport.hpp"
50 #include "prims/jvmtiRedefineClassesTrace.hpp"
51 #include "prims/jvmtiRedefineClasses.hpp"
52 #include "prims/methodComparator.hpp"
53 #include "runtime/fieldDescriptor.hpp"
54 #include "runtime/handles.inline.hpp"
55 #include "runtime/javaCalls.hpp"
56 #include "runtime/mutexLocker.hpp"
57 #include "runtime/thread.inline.hpp"
58 #include "services/classLoadingService.hpp"
59 #include "services/threadService.hpp"
60 #include "utilities/dtrace.hpp"
61 #include "utilities/macros.hpp"
62 #if INCLUDE_ALL_GCS
63 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
64 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
65 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
66 #include "gc_implementation/g1/g1RemSet.inline.hpp"
67 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
68 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
69 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
70 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
71 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
72 #include "oops/oop.pcgc.inline.hpp"
73 #endif // INCLUDE_ALL_GCS
74 #ifdef COMPILER1
75 #include "c1/c1_Compiler.hpp"
76 #endif
77
78 #ifdef DTRACE_ENABLED
79
80 #ifndef USDT2
81
82 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
83 char*, intptr_t, oop, intptr_t);
84 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
85 char*, intptr_t, oop, intptr_t, int);
86 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
87 char*, intptr_t, oop, intptr_t, int);
88 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
89 char*, intptr_t, oop, intptr_t, int);
90 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
91 char*, intptr_t, oop, intptr_t, int);
92 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
93 char*, intptr_t, oop, intptr_t, int);
94 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
95 char*, intptr_t, oop, intptr_t, int);
96 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
97 char*, intptr_t, oop, intptr_t, int);
98
99 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
100 { \
101 char* data = NULL; \
102 int len = 0; \
103 Symbol* name = (clss)->name(); \
104 if (name != NULL) { \
105 data = (char*)name->bytes(); \
106 len = name->utf8_length(); \
107 } \
108 HS_DTRACE_PROBE4(hotspot, class__initialization__##type, \
109 data, len, SOLARIS_ONLY((void *))(clss)->class_loader(), thread_type); \
110 }
111
112 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
113 { \
114 char* data = NULL; \
115 int len = 0; \
116 Symbol* name = (clss)->name(); \
117 if (name != NULL) { \
118 data = (char*)name->bytes(); \
119 len = name->utf8_length(); \
120 } \
121 HS_DTRACE_PROBE5(hotspot, class__initialization__##type, \
122 data, len, SOLARIS_ONLY((void *))(clss)->class_loader(), thread_type, wait); \
123 }
124 #else /* USDT2 */
125
126 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
127 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
128 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
129 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
130 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
131 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
132 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
133 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
134 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
135 { \
136 char* data = NULL; \
137 int len = 0; \
138 Symbol* name = (clss)->name(); \
139 if (name != NULL) { \
140 data = (char*)name->bytes(); \
141 len = name->utf8_length(); \
142 } \
143 HOTSPOT_CLASS_INITIALIZATION_##type( \
144 data, len, (clss)->class_loader(), thread_type); \
145 }
146
147 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
148 { \
149 char* data = NULL; \
150 int len = 0; \
151 Symbol* name = (clss)->name(); \
152 if (name != NULL) { \
153 data = (char*)name->bytes(); \
154 len = name->utf8_length(); \
155 } \
156 HOTSPOT_CLASS_INITIALIZATION_##type( \
157 data, len, (clss)->class_loader(), thread_type, wait); \
158 }
159 #endif /* USDT2 */
160
161 #else // ndef DTRACE_ENABLED
162
163 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
164 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
165
166 #endif // ndef DTRACE_ENABLED
167
168 volatile int InstanceKlass::_total_instanceKlass_count = 0;
169
170 InstanceKlass* InstanceKlass::allocate_instance_klass(
171 ClassLoaderData* loader_data,
172 int vtable_len,
173 int itable_len,
174 int static_field_size,
175 int nonstatic_oop_map_size,
176 ReferenceType rt,
177 AccessFlags access_flags,
178 Symbol* name,
179 Klass* super_klass,
180 bool is_anonymous,
181 TRAPS) {
182
183 int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
184 access_flags.is_interface(), is_anonymous);
185
186 // Allocation
187 InstanceKlass* ik;
188 if (rt == REF_NONE) {
189 if (name == vmSymbols::java_lang_Class()) {
190 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
191 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
192 access_flags, is_anonymous);
193 } else if (name == vmSymbols::java_lang_ClassLoader() ||
194 (SystemDictionary::ClassLoader_klass_loaded() &&
195 super_klass != NULL &&
196 super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
197 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
198 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
199 access_flags, is_anonymous);
200 } else {
201 // normal class
202 ik = new (loader_data, size, THREAD) InstanceKlass(
203 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
204 access_flags, is_anonymous);
205 }
206 } else {
207 // reference klass
208 ik = new (loader_data, size, THREAD) InstanceRefKlass(
209 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
210 access_flags, is_anonymous);
211 }
212
213 // Check for pending exception before adding to the loader data and incrementing
214 // class count. Can get OOM here.
215 if (HAS_PENDING_EXCEPTION) {
216 return NULL;
217 }
218
219 // Add all classes to our internal class loader list here,
220 // including classes in the bootstrap (NULL) class loader.
221 loader_data->add_class(ik);
222
223 Atomic::inc(&_total_instanceKlass_count);
224 return ik;
225 }
226
227
228 // copy method ordering from resource area to Metaspace
229 void InstanceKlass::copy_method_ordering(intArray* m, TRAPS) {
230 if (m != NULL) {
231 // allocate a new array and copy contents (memcpy?)
232 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
233 for (int i = 0; i < m->length(); i++) {
234 _method_ordering->at_put(i, m->at(i));
235 }
236 } else {
237 _method_ordering = Universe::the_empty_int_array();
238 }
239 }
240
241 // create a new array of vtable_indices for default methods
242 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
243 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
244 assert(default_vtable_indices() == NULL, "only create once");
245 set_default_vtable_indices(vtable_indices);
246 return vtable_indices;
247 }
248
249 InstanceKlass::InstanceKlass(int vtable_len,
250 int itable_len,
251 int static_field_size,
252 int nonstatic_oop_map_size,
253 ReferenceType rt,
254 AccessFlags access_flags,
255 bool is_anonymous) {
256 No_Safepoint_Verifier no_safepoint; // until k becomes parsable
257
258 int iksize = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
259 access_flags.is_interface(), is_anonymous);
260
261 set_vtable_length(vtable_len);
262 set_itable_length(itable_len);
263 set_static_field_size(static_field_size);
264 set_nonstatic_oop_map_size(nonstatic_oop_map_size);
265 set_access_flags(access_flags);
266 _misc_flags = 0; // initialize to zero
267 set_is_anonymous(is_anonymous);
268 assert(size() == iksize, "wrong size for object");
269
270 set_array_klasses(NULL);
271 set_methods(NULL);
272 set_method_ordering(NULL);
273 set_default_methods(NULL);
274 set_default_vtable_indices(NULL);
275 set_local_interfaces(NULL);
276 set_transitive_interfaces(NULL);
277 init_implementor();
278 set_fields(NULL, 0);
279 set_constants(NULL);
280 set_class_loader_data(NULL);
281 set_source_file_name_index(0);
282 set_source_debug_extension(NULL, 0);
283 set_array_name(NULL);
284 set_inner_classes(NULL);
285 set_static_oop_field_count(0);
286 set_nonstatic_field_size(0);
287 set_is_marked_dependent(false);
288 set_init_state(InstanceKlass::allocated);
289 set_init_thread(NULL);
290 set_reference_type(rt);
291 set_oop_map_cache(NULL);
292 set_jni_ids(NULL);
293 set_osr_nmethods_head(NULL);
294 set_breakpoints(NULL);
295 init_previous_versions();
296 set_generic_signature_index(0);
297 release_set_methods_jmethod_ids(NULL);
298 set_annotations(NULL);
299 set_jvmti_cached_class_field_map(NULL);
300 set_initial_method_idnum(0);
301 _dependencies = NULL;
302 set_jvmti_cached_class_field_map(NULL);
303 set_cached_class_file(NULL);
304 set_initial_method_idnum(0);
305 set_minor_version(0);
306 set_major_version(0);
307 NOT_PRODUCT(_verify_count = 0;)
308
309 // initialize the non-header words to zero
310 intptr_t* p = (intptr_t*)this;
311 for (int index = InstanceKlass::header_size(); index < iksize; index++) {
312 p[index] = NULL_WORD;
313 }
314
315 // Set temporary value until parseClassFile updates it with the real instance
316 // size.
317 set_layout_helper(Klass::instance_layout_helper(0, true));
318 }
319
320
321 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
322 Array<Method*>* methods) {
323 if (methods != NULL && methods != Universe::the_empty_method_array() &&
324 !methods->is_shared()) {
325 for (int i = 0; i < methods->length(); i++) {
326 Method* method = methods->at(i);
327 if (method == NULL) continue; // maybe null if error processing
328 // Only want to delete methods that are not executing for RedefineClasses.
329 // The previous version will point to them so they're not totally dangling
330 assert (!method->on_stack(), "shouldn't be called with methods on stack");
331 MetadataFactory::free_metadata(loader_data, method);
332 }
333 MetadataFactory::free_array<Method*>(loader_data, methods);
334 }
335 }
336
337 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
338 Klass* super_klass,
339 Array<Klass*>* local_interfaces,
340 Array<Klass*>* transitive_interfaces) {
341 // Only deallocate transitive interfaces if not empty, same as super class
342 // or same as local interfaces. See code in parseClassFile.
343 Array<Klass*>* ti = transitive_interfaces;
344 if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
345 // check that the interfaces don't come from super class
346 Array<Klass*>* sti = (super_klass == NULL) ? NULL :
347 InstanceKlass::cast(super_klass)->transitive_interfaces();
348 if (ti != sti && ti != NULL && !ti->is_shared()) {
349 MetadataFactory::free_array<Klass*>(loader_data, ti);
350 }
351 }
352
353 // local interfaces can be empty
354 if (local_interfaces != Universe::the_empty_klass_array() &&
355 local_interfaces != NULL && !local_interfaces->is_shared()) {
356 MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
357 }
358 }
359
360 // This function deallocates the metadata and C heap pointers that the
361 // InstanceKlass points to.
362 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
363
364 // Orphan the mirror first, CMS thinks it's still live.
365 if (java_mirror() != NULL) {
366 java_lang_Class::set_klass(java_mirror(), NULL);
367 }
368
369 // Need to take this class off the class loader data list.
370 loader_data->remove_class(this);
371
372 // The array_klass for this class is created later, after error handling.
373 // For class redefinition, we keep the original class so this scratch class
374 // doesn't have an array class. Either way, assert that there is nothing
375 // to deallocate.
376 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
377
378 // Release C heap allocated data that this might point to, which includes
379 // reference counting symbol names.
380 release_C_heap_structures();
381
382 deallocate_methods(loader_data, methods());
383 set_methods(NULL);
384
385 if (method_ordering() != NULL &&
386 method_ordering() != Universe::the_empty_int_array() &&
387 !method_ordering()->is_shared()) {
388 MetadataFactory::free_array<int>(loader_data, method_ordering());
389 }
390 set_method_ordering(NULL);
391
392 // default methods can be empty
393 if (default_methods() != NULL &&
394 default_methods() != Universe::the_empty_method_array() &&
395 !default_methods()->is_shared()) {
396 MetadataFactory::free_array<Method*>(loader_data, default_methods());
397 }
398 // Do NOT deallocate the default methods, they are owned by superinterfaces.
399 set_default_methods(NULL);
400
401 // default methods vtable indices can be empty
402 if (default_vtable_indices() != NULL &&
403 !default_vtable_indices()->is_shared()) {
404 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
405 }
406 set_default_vtable_indices(NULL);
407
408
409 // This array is in Klass, but remove it with the InstanceKlass since
410 // this place would be the only caller and it can share memory with transitive
411 // interfaces.
412 if (secondary_supers() != NULL &&
413 secondary_supers() != Universe::the_empty_klass_array() &&
414 secondary_supers() != transitive_interfaces() &&
415 !secondary_supers()->is_shared()) {
416 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
417 }
418 set_secondary_supers(NULL);
419
420 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
421 set_transitive_interfaces(NULL);
422 set_local_interfaces(NULL);
423
424 if (fields() != NULL && !fields()->is_shared()) {
425 MetadataFactory::free_array<jushort>(loader_data, fields());
426 }
427 set_fields(NULL, 0);
428
429 // If a method from a redefined class is using this constant pool, don't
430 // delete it, yet. The new class's previous version will point to this.
431 if (constants() != NULL) {
432 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
433 if (!constants()->is_shared()) {
434 MetadataFactory::free_metadata(loader_data, constants());
435 }
436 set_constants(NULL);
437 }
438
439 if (inner_classes() != NULL &&
440 inner_classes() != Universe::the_empty_short_array() &&
441 !inner_classes()->is_shared()) {
442 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
443 }
444 set_inner_classes(NULL);
445
446 // We should deallocate the Annotations instance if it's not in shared spaces.
447 if (annotations() != NULL && !annotations()->is_shared()) {
448 MetadataFactory::free_metadata(loader_data, annotations());
449 }
450 set_annotations(NULL);
451 }
452
453 bool InstanceKlass::should_be_initialized() const {
454 return !is_initialized();
455 }
456
457 klassVtable* InstanceKlass::vtable() const {
458 return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
459 }
460
461 klassItable* InstanceKlass::itable() const {
462 return new klassItable(instanceKlassHandle(this));
463 }
464
465 void InstanceKlass::eager_initialize(Thread *thread) {
466 if (!EagerInitialization) return;
467
468 if (this->is_not_initialized()) {
469 // abort if the the class has a class initializer
470 if (this->class_initializer() != NULL) return;
471
472 // abort if it is java.lang.Object (initialization is handled in genesis)
473 Klass* super = this->super();
474 if (super == NULL) return;
475
476 // abort if the super class should be initialized
477 if (!InstanceKlass::cast(super)->is_initialized()) return;
478
479 // call body to expose the this pointer
480 instanceKlassHandle this_oop(thread, this);
481 eager_initialize_impl(this_oop);
482 }
483 }
484
485 // JVMTI spec thinks there are signers and protection domain in the
486 // instanceKlass. These accessors pretend these fields are there.
487 // The hprof specification also thinks these fields are in InstanceKlass.
488 oop InstanceKlass::protection_domain() const {
489 // return the protection_domain from the mirror
490 return java_lang_Class::protection_domain(java_mirror());
491 }
492
493 // To remove these from requires an incompatible change and CCC request.
494 objArrayOop InstanceKlass::signers() const {
495 // return the signers from the mirror
496 return java_lang_Class::signers(java_mirror());
497 }
498
499 oop InstanceKlass::init_lock() const {
500 // return the init lock from the mirror
501 oop lock = java_lang_Class::init_lock(java_mirror());
502 assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
503 "only fully initialized state can have a null lock");
504 return lock;
505 }
506
507 // Set the initialization lock to null so the object can be GC'ed. Any racing
508 // threads to get this lock will see a null lock and will not lock.
509 // That's okay because they all check for initialized state after getting
510 // the lock and return.
511 void InstanceKlass::fence_and_clear_init_lock() {
512 // make sure previous stores are all done, notably the init_state.
513 OrderAccess::storestore();
514 java_lang_Class::set_init_lock(java_mirror(), NULL);
515 assert(!is_not_initialized(), "class must be initialized now");
516 }
517
518 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
519 EXCEPTION_MARK;
520 oop init_lock = this_oop->init_lock();
521 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
522
523 // abort if someone beat us to the initialization
524 if (!this_oop->is_not_initialized()) return; // note: not equivalent to is_initialized()
525
526 ClassState old_state = this_oop->init_state();
527 link_class_impl(this_oop, true, THREAD);
528 if (HAS_PENDING_EXCEPTION) {
529 CLEAR_PENDING_EXCEPTION;
530 // Abort if linking the class throws an exception.
531
532 // Use a test to avoid redundantly resetting the state if there's
533 // no change. Set_init_state() asserts that state changes make
534 // progress, whereas here we might just be spinning in place.
535 if( old_state != this_oop->_init_state )
536 this_oop->set_init_state (old_state);
537 } else {
538 // linking successfull, mark class as initialized
539 this_oop->set_init_state (fully_initialized);
540 this_oop->fence_and_clear_init_lock();
541 // trace
542 if (TraceClassInitialization) {
543 ResourceMark rm(THREAD);
544 tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
545 }
546 }
547 }
548
549
550 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
551 // process. The step comments refers to the procedure described in that section.
552 // Note: implementation moved to static method to expose the this pointer.
553 void InstanceKlass::initialize(TRAPS) {
554 if (this->should_be_initialized()) {
555 HandleMark hm(THREAD);
556 instanceKlassHandle this_oop(THREAD, this);
557 initialize_impl(this_oop, CHECK);
558 // Note: at this point the class may be initialized
559 // OR it may be in the state of being initialized
560 // in case of recursive initialization!
561 } else {
562 assert(is_initialized(), "sanity check");
563 }
564 }
565
566
567 bool InstanceKlass::verify_code(
568 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
569 // 1) Verify the bytecodes
570 Verifier::Mode mode =
571 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
572 return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
573 }
574
575
576 // Used exclusively by the shared spaces dump mechanism to prevent
577 // classes mapped into the shared regions in new VMs from appearing linked.
578
579 void InstanceKlass::unlink_class() {
580 assert(is_linked(), "must be linked");
581 _init_state = loaded;
582 }
583
584 void InstanceKlass::link_class(TRAPS) {
585 assert(is_loaded(), "must be loaded");
586 if (!is_linked()) {
587 HandleMark hm(THREAD);
588 instanceKlassHandle this_oop(THREAD, this);
589 link_class_impl(this_oop, true, CHECK);
590 }
591 }
592
593 // Called to verify that a class can link during initialization, without
594 // throwing a VerifyError.
595 bool InstanceKlass::link_class_or_fail(TRAPS) {
596 assert(is_loaded(), "must be loaded");
597 if (!is_linked()) {
598 HandleMark hm(THREAD);
599 instanceKlassHandle this_oop(THREAD, this);
600 link_class_impl(this_oop, false, CHECK_false);
601 }
602 return is_linked();
603 }
604
605 bool InstanceKlass::link_class_impl(
606 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
607 // check for error state
608 if (this_oop->is_in_error_state()) {
609 ResourceMark rm(THREAD);
610 THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
611 this_oop->external_name(), false);
612 }
613 // return if already verified
614 if (this_oop->is_linked()) {
615 return true;
616 }
617
618 // Timing
619 // timer handles recursion
620 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
621 JavaThread* jt = (JavaThread*)THREAD;
622
623 // link super class before linking this class
624 instanceKlassHandle super(THREAD, this_oop->super());
625 if (super.not_null()) {
626 if (super->is_interface()) { // check if super class is an interface
627 ResourceMark rm(THREAD);
628 Exceptions::fthrow(
629 THREAD_AND_LOCATION,
630 vmSymbols::java_lang_IncompatibleClassChangeError(),
631 "class %s has interface %s as super class",
632 this_oop->external_name(),
633 super->external_name()
634 );
635 return false;
636 }
637
638 link_class_impl(super, throw_verifyerror, CHECK_false);
639 }
640
641 // link all interfaces implemented by this class before linking this class
642 Array<Klass*>* interfaces = this_oop->local_interfaces();
643 int num_interfaces = interfaces->length();
644 for (int index = 0; index < num_interfaces; index++) {
645 HandleMark hm(THREAD);
646 instanceKlassHandle ih(THREAD, interfaces->at(index));
647 link_class_impl(ih, throw_verifyerror, CHECK_false);
648 }
649
650 // in case the class is linked in the process of linking its superclasses
651 if (this_oop->is_linked()) {
652 return true;
653 }
654
655 // trace only the link time for this klass that includes
656 // the verification time
657 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
658 ClassLoader::perf_class_link_selftime(),
659 ClassLoader::perf_classes_linked(),
660 jt->get_thread_stat()->perf_recursion_counts_addr(),
661 jt->get_thread_stat()->perf_timers_addr(),
662 PerfClassTraceTime::CLASS_LINK);
663
664 // verification & rewriting
665 {
666 oop init_lock = this_oop->init_lock();
667 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
668 // rewritten will have been set if loader constraint error found
669 // on an earlier link attempt
670 // don't verify or rewrite if already rewritten
671
672 if (!this_oop->is_linked()) {
673 if (!this_oop->is_rewritten()) {
674 {
675 // Timer includes any side effects of class verification (resolution,
676 // etc), but not recursive entry into verify_code().
677 PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
678 ClassLoader::perf_class_verify_selftime(),
679 ClassLoader::perf_classes_verified(),
680 jt->get_thread_stat()->perf_recursion_counts_addr(),
681 jt->get_thread_stat()->perf_timers_addr(),
682 PerfClassTraceTime::CLASS_VERIFY);
683 bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
684 if (!verify_ok) {
685 return false;
686 }
687 }
688
689 // Just in case a side-effect of verify linked this class already
690 // (which can sometimes happen since the verifier loads classes
691 // using custom class loaders, which are free to initialize things)
692 if (this_oop->is_linked()) {
693 return true;
694 }
695
696 // also sets rewritten
697 this_oop->rewrite_class(CHECK_false);
698 }
699
700 // relocate jsrs and link methods after they are all rewritten
701 this_oop->link_methods(CHECK_false);
702
703 // Initialize the vtable and interface table after
704 // methods have been rewritten since rewrite may
705 // fabricate new Method*s.
706 // also does loader constraint checking
707 if (!this_oop()->is_shared()) {
708 ResourceMark rm(THREAD);
709 this_oop->vtable()->initialize_vtable(true, CHECK_false);
710 this_oop->itable()->initialize_itable(true, CHECK_false);
711 }
712 #ifdef ASSERT
713 else {
714 ResourceMark rm(THREAD);
715 this_oop->vtable()->verify(tty, true);
716 // In case itable verification is ever added.
717 // this_oop->itable()->verify(tty, true);
718 }
719 #endif
720 this_oop->set_init_state(linked);
721 if (JvmtiExport::should_post_class_prepare()) {
722 Thread *thread = THREAD;
723 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
724 JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
725 }
726 }
727 }
728 return true;
729 }
730
731
732 // Rewrite the byte codes of all of the methods of a class.
733 // The rewriter must be called exactly once. Rewriting must happen after
734 // verification but before the first method of the class is executed.
735 void InstanceKlass::rewrite_class(TRAPS) {
736 assert(is_loaded(), "must be loaded");
737 instanceKlassHandle this_oop(THREAD, this);
738 if (this_oop->is_rewritten()) {
739 assert(this_oop()->is_shared(), "rewriting an unshared class?");
740 return;
741 }
742 Rewriter::rewrite(this_oop, CHECK);
743 this_oop->set_rewritten();
744 }
745
746 // Now relocate and link method entry points after class is rewritten.
747 // This is outside is_rewritten flag. In case of an exception, it can be
748 // executed more than once.
749 void InstanceKlass::link_methods(TRAPS) {
750 int len = methods()->length();
751 for (int i = len-1; i >= 0; i--) {
752 methodHandle m(THREAD, methods()->at(i));
753
754 // Set up method entry points for compiler and interpreter .
755 m->link_method(m, CHECK);
756
757 // This is for JVMTI and unrelated to relocator but the last thing we do
758 #ifdef ASSERT
759 if (StressMethodComparator) {
760 ResourceMark rm(THREAD);
761 static int nmc = 0;
762 for (int j = i; j >= 0 && j >= i-4; j--) {
763 if ((++nmc % 1000) == 0) tty->print_cr("Have run MethodComparator %d times...", nmc);
764 bool z = MethodComparator::methods_EMCP(m(),
765 methods()->at(j));
766 if (j == i && !z) {
767 tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
768 assert(z, "method must compare equal to itself");
769 }
770 }
771 }
772 #endif //ASSERT
773 }
774 }
775
776
777 void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
778 // Make sure klass is linked (verified) before initialization
779 // A class could already be verified, since it has been reflected upon.
780 this_oop->link_class(CHECK);
781
782 DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
783
784 bool wait = false;
785
786 // refer to the JVM book page 47 for description of steps
787 // Step 1
788 {
789 oop init_lock = this_oop->init_lock();
790 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
791
792 Thread *self = THREAD; // it's passed the current thread
793
794 // Step 2
795 // If we were to use wait() instead of waitInterruptibly() then
796 // we might end up throwing IE from link/symbol resolution sites
797 // that aren't expected to throw. This would wreak havoc. See 6320309.
798 while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
799 wait = true;
800 ol.waitUninterruptibly(CHECK);
801 }
802
803 // Step 3
804 if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
805 DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
806 return;
807 }
808
809 // Step 4
810 if (this_oop->is_initialized()) {
811 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
812 return;
813 }
814
815 // Step 5
816 if (this_oop->is_in_error_state()) {
817 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
818 ResourceMark rm(THREAD);
819 const char* desc = "Could not initialize class ";
820 const char* className = this_oop->external_name();
821 size_t msglen = strlen(desc) + strlen(className) + 1;
822 char* message = NEW_RESOURCE_ARRAY(char, msglen);
823 if (NULL == message) {
824 // Out of memory: can't create detailed error message
825 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
826 } else {
827 jio_snprintf(message, msglen, "%s%s", desc, className);
828 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
829 }
830 }
831
832 // Step 6
833 this_oop->set_init_state(being_initialized);
834 this_oop->set_init_thread(self);
835 }
836
837 // Step 7
838 Klass* super_klass = this_oop->super();
839 if (super_klass != NULL && !this_oop->is_interface() && super_klass->should_be_initialized()) {
840 super_klass->initialize(THREAD);
841
842 if (HAS_PENDING_EXCEPTION) {
843 Handle e(THREAD, PENDING_EXCEPTION);
844 CLEAR_PENDING_EXCEPTION;
845 {
846 EXCEPTION_MARK;
847 this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
848 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, superclass initialization error is thrown below
849 }
850 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
851 THROW_OOP(e());
852 }
853 }
854
855 if (this_oop->has_default_methods()) {
856 // Step 7.5: initialize any interfaces which have default methods
857 for (int i = 0; i < this_oop->local_interfaces()->length(); ++i) {
858 Klass* iface = this_oop->local_interfaces()->at(i);
859 InstanceKlass* ik = InstanceKlass::cast(iface);
860 if (ik->has_default_methods() && ik->should_be_initialized()) {
861 ik->initialize(THREAD);
862
863 if (HAS_PENDING_EXCEPTION) {
864 Handle e(THREAD, PENDING_EXCEPTION);
865 CLEAR_PENDING_EXCEPTION;
866 {
867 EXCEPTION_MARK;
868 // Locks object, set state, and notify all waiting threads
869 this_oop->set_initialization_state_and_notify(
870 initialization_error, THREAD);
871
872 // ignore any exception thrown, superclass initialization error is
873 // thrown below
874 CLEAR_PENDING_EXCEPTION;
875 }
876 DTRACE_CLASSINIT_PROBE_WAIT(
877 super__failed, InstanceKlass::cast(this_oop()), -1, wait);
878 THROW_OOP(e());
879 }
880 }
881 }
882 }
883
884 // Step 8
885 {
886 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
887 JavaThread* jt = (JavaThread*)THREAD;
888 DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
889 // Timer includes any side effects of class initialization (resolution,
890 // etc), but not recursive entry into call_class_initializer().
891 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
892 ClassLoader::perf_class_init_selftime(),
893 ClassLoader::perf_classes_inited(),
894 jt->get_thread_stat()->perf_recursion_counts_addr(),
895 jt->get_thread_stat()->perf_timers_addr(),
896 PerfClassTraceTime::CLASS_CLINIT);
897 this_oop->call_class_initializer(THREAD);
898 }
899
900 // Step 9
901 if (!HAS_PENDING_EXCEPTION) {
902 this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
903 { ResourceMark rm(THREAD);
904 debug_only(this_oop->vtable()->verify(tty, true);)
905 }
906 }
907 else {
908 // Step 10 and 11
909 Handle e(THREAD, PENDING_EXCEPTION);
910 CLEAR_PENDING_EXCEPTION;
911 {
912 EXCEPTION_MARK;
913 this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
914 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
915 }
916 DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
917 if (e->is_a(SystemDictionary::Error_klass())) {
918 THROW_OOP(e());
919 } else {
920 JavaCallArguments args(e);
921 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
922 vmSymbols::throwable_void_signature(),
923 &args);
924 }
925 }
926 DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
927 }
928
929
930 // Note: implementation moved to static method to expose the this pointer.
931 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
932 instanceKlassHandle kh(THREAD, this);
933 set_initialization_state_and_notify_impl(kh, state, CHECK);
934 }
935
936 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
937 oop init_lock = this_oop->init_lock();
938 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
939 this_oop->set_init_state(state);
940 this_oop->fence_and_clear_init_lock();
941 ol.notify_all(CHECK);
942 }
943
944 // The embedded _implementor field can only record one implementor.
945 // When there are more than one implementors, the _implementor field
946 // is set to the interface Klass* itself. Following are the possible
947 // values for the _implementor field:
948 // NULL - no implementor
949 // implementor Klass* - one implementor
950 // self - more than one implementor
951 //
952 // The _implementor field only exists for interfaces.
953 void InstanceKlass::add_implementor(Klass* k) {
954 assert(Compile_lock->owned_by_self(), "");
955 assert(is_interface(), "not interface");
956 // Filter out my subinterfaces.
957 // (Note: Interfaces are never on the subklass list.)
958 if (InstanceKlass::cast(k)->is_interface()) return;
959
960 // Filter out subclasses whose supers already implement me.
961 // (Note: CHA must walk subclasses of direct implementors
962 // in order to locate indirect implementors.)
963 Klass* sk = InstanceKlass::cast(k)->super();
964 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
965 // We only need to check one immediate superclass, since the
966 // implements_interface query looks at transitive_interfaces.
967 // Any supers of the super have the same (or fewer) transitive_interfaces.
968 return;
969
970 Klass* ik = implementor();
971 if (ik == NULL) {
972 set_implementor(k);
973 } else if (ik != this) {
974 // There is already an implementor. Use itself as an indicator of
975 // more than one implementors.
976 set_implementor(this);
977 }
978
979 // The implementor also implements the transitive_interfaces
980 for (int index = 0; index < local_interfaces()->length(); index++) {
981 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
982 }
983 }
984
985 void InstanceKlass::init_implementor() {
986 if (is_interface()) {
987 set_implementor(NULL);
988 }
989 }
990
991
992 void InstanceKlass::process_interfaces(Thread *thread) {
993 // link this class into the implementors list of every interface it implements
994 Klass* this_as_klass_oop = this;
995 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
996 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
997 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
998 assert(interf->is_interface(), "expected interface");
999 interf->add_implementor(this_as_klass_oop);
1000 }
1001 }
1002
1003 bool InstanceKlass::can_be_primary_super_slow() const {
1004 if (is_interface())
1005 return false;
1006 else
1007 return Klass::can_be_primary_super_slow();
1008 }
1009
1010 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
1011 // The secondaries are the implemented interfaces.
1012 InstanceKlass* ik = InstanceKlass::cast(this);
1013 Array<Klass*>* interfaces = ik->transitive_interfaces();
1014 int num_secondaries = num_extra_slots + interfaces->length();
1015 if (num_secondaries == 0) {
1016 // Must share this for correct bootstrapping!
1017 set_secondary_supers(Universe::the_empty_klass_array());
1018 return NULL;
1019 } else if (num_extra_slots == 0) {
1020 // The secondary super list is exactly the same as the transitive interfaces.
1021 // Redefine classes has to be careful not to delete this!
1022 set_secondary_supers(interfaces);
1023 return NULL;
1024 } else {
1025 // Copy transitive interfaces to a temporary growable array to be constructed
1026 // into the secondary super list with extra slots.
1027 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1028 for (int i = 0; i < interfaces->length(); i++) {
1029 secondaries->push(interfaces->at(i));
1030 }
1031 return secondaries;
1032 }
1033 }
1034
1035 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
1036 if (k->is_interface()) {
1037 return implements_interface(k);
1038 } else {
1039 return Klass::compute_is_subtype_of(k);
1040 }
1041 }
1042
1043 bool InstanceKlass::implements_interface(Klass* k) const {
1044 if (this == k) return true;
1045 assert(k->is_interface(), "should be an interface class");
1046 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1047 if (transitive_interfaces()->at(i) == k) {
1048 return true;
1049 }
1050 }
1051 return false;
1052 }
1053
1054 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1055 // Verify direct super interface
1056 if (this == k) return true;
1057 assert(k->is_interface(), "should be an interface class");
1058 for (int i = 0; i < local_interfaces()->length(); i++) {
1059 if (local_interfaces()->at(i) == k) {
1060 return true;
1061 }
1062 }
1063 return false;
1064 }
1065
1066 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1067 if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
1068 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
1069 report_java_out_of_memory("Requested array size exceeds VM limit");
1070 JvmtiExport::post_array_size_exhausted();
1071 THROW_OOP_0(Universe::out_of_memory_error_array_size());
1072 }
1073 int size = objArrayOopDesc::object_size(length);
1074 Klass* ak = array_klass(n, CHECK_NULL);
1075 KlassHandle h_ak (THREAD, ak);
1076 objArrayOop o =
1077 (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
1078 return o;
1079 }
1080
1081 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1082 if (TraceFinalizerRegistration) {
1083 tty->print("Registered ");
1084 i->print_value_on(tty);
1085 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
1086 }
1087 instanceHandle h_i(THREAD, i);
1088 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1089 JavaValue result(T_VOID);
1090 JavaCallArguments args(h_i);
1091 methodHandle mh (THREAD, Universe::finalizer_register_method());
1092 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1093 return h_i();
1094 }
1095
1096 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1097 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1098 int size = size_helper(); // Query before forming handle.
1099
1100 KlassHandle h_k(THREAD, this);
1101
1102 instanceOop i;
1103
1104 i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
1105 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1106 i = register_finalizer(i, CHECK_NULL);
1107 }
1108 return i;
1109 }
1110
1111 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1112 if (is_interface() || is_abstract()) {
1113 ResourceMark rm(THREAD);
1114 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1115 : vmSymbols::java_lang_InstantiationException(), external_name());
1116 }
1117 if (this == SystemDictionary::Class_klass()) {
1118 ResourceMark rm(THREAD);
1119 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1120 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1121 }
1122 }
1123
1124 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1125 instanceKlassHandle this_oop(THREAD, this);
1126 return array_klass_impl(this_oop, or_null, n, THREAD);
1127 }
1128
1129 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
1130 if (this_oop->array_klasses() == NULL) {
1131 if (or_null) return NULL;
1132
1133 ResourceMark rm;
1134 JavaThread *jt = (JavaThread *)THREAD;
1135 {
1136 // Atomic creation of array_klasses
1137 MutexLocker mc(Compile_lock, THREAD); // for vtables
1138 MutexLocker ma(MultiArray_lock, THREAD);
1139
1140 // Check if update has already taken place
1141 if (this_oop->array_klasses() == NULL) {
1142 Klass* k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
1143 this_oop->set_array_klasses(k);
1144 }
1145 }
1146 }
1147 // _this will always be set at this point
1148 ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
1149 if (or_null) {
1150 return oak->array_klass_or_null(n);
1151 }
1152 return oak->array_klass(n, CHECK_NULL);
1153 }
1154
1155 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1156 return array_klass_impl(or_null, 1, THREAD);
1157 }
1158
1159 void InstanceKlass::call_class_initializer(TRAPS) {
1160 instanceKlassHandle ik (THREAD, this);
1161 call_class_initializer_impl(ik, THREAD);
1162 }
1163
1164 static int call_class_initializer_impl_counter = 0; // for debugging
1165
1166 Method* InstanceKlass::class_initializer() {
1167 Method* clinit = find_method(
1168 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1169 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1170 return clinit;
1171 }
1172 return NULL;
1173 }
1174
1175 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
1176 if (ReplayCompiles &&
1177 (ReplaySuppressInitializers == 1 ||
1178 ReplaySuppressInitializers >= 2 && this_oop->class_loader() != NULL)) {
1179 // Hide the existence of the initializer for the purpose of replaying the compile
1180 return;
1181 }
1182
1183 methodHandle h_method(THREAD, this_oop->class_initializer());
1184 assert(!this_oop->is_initialized(), "we cannot initialize twice");
1185 if (TraceClassInitialization) {
1186 tty->print("%d Initializing ", call_class_initializer_impl_counter++);
1187 this_oop->name()->print_value();
1188 tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
1189 }
1190 if (h_method() != NULL) {
1191 JavaCallArguments args; // No arguments
1192 JavaValue result(T_VOID);
1193 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1194 }
1195 }
1196
1197
1198 void InstanceKlass::mask_for(methodHandle method, int bci,
1199 InterpreterOopMap* entry_for) {
1200 // Dirty read, then double-check under a lock.
1201 if (_oop_map_cache == NULL) {
1202 // Otherwise, allocate a new one.
1203 MutexLocker x(OopMapCacheAlloc_lock);
1204 // First time use. Allocate a cache in C heap
1205 if (_oop_map_cache == NULL) {
1206 // Release stores from OopMapCache constructor before assignment
1207 // to _oop_map_cache. C++ compilers on ppc do not emit the
1208 // required memory barrier only because of the volatile
1209 // qualifier of _oop_map_cache.
1210 OrderAccess::release_store_ptr(&_oop_map_cache, new OopMapCache());
1211 }
1212 }
1213 // _oop_map_cache is constant after init; lookup below does is own locking.
1214 _oop_map_cache->lookup(method, bci, entry_for);
1215 }
1216
1217
1218 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1219 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1220 Symbol* f_name = fs.name();
1221 Symbol* f_sig = fs.signature();
1222 if (f_name == name && f_sig == sig) {
1223 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1224 return true;
1225 }
1226 }
1227 return false;
1228 }
1229
1230
1231 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1232 const int n = local_interfaces()->length();
1233 for (int i = 0; i < n; i++) {
1234 Klass* intf1 = local_interfaces()->at(i);
1235 assert(intf1->is_interface(), "just checking type");
1236 // search for field in current interface
1237 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1238 assert(fd->is_static(), "interface field must be static");
1239 return intf1;
1240 }
1241 // search for field in direct superinterfaces
1242 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1243 if (intf2 != NULL) return intf2;
1244 }
1245 // otherwise field lookup fails
1246 return NULL;
1247 }
1248
1249
1250 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1251 // search order according to newest JVM spec (5.4.3.2, p.167).
1252 // 1) search for field in current klass
1253 if (find_local_field(name, sig, fd)) {
1254 return const_cast<InstanceKlass*>(this);
1255 }
1256 // 2) search for field recursively in direct superinterfaces
1257 { Klass* intf = find_interface_field(name, sig, fd);
1258 if (intf != NULL) return intf;
1259 }
1260 // 3) apply field lookup recursively if superclass exists
1261 { Klass* supr = super();
1262 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1263 }
1264 // 4) otherwise field lookup fails
1265 return NULL;
1266 }
1267
1268
1269 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1270 // search order according to newest JVM spec (5.4.3.2, p.167).
1271 // 1) search for field in current klass
1272 if (find_local_field(name, sig, fd)) {
1273 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1274 }
1275 // 2) search for field recursively in direct superinterfaces
1276 if (is_static) {
1277 Klass* intf = find_interface_field(name, sig, fd);
1278 if (intf != NULL) return intf;
1279 }
1280 // 3) apply field lookup recursively if superclass exists
1281 { Klass* supr = super();
1282 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1283 }
1284 // 4) otherwise field lookup fails
1285 return NULL;
1286 }
1287
1288
1289 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1290 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1291 if (fs.offset() == offset) {
1292 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1293 if (fd->is_static() == is_static) return true;
1294 }
1295 }
1296 return false;
1297 }
1298
1299
1300 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1301 Klass* klass = const_cast<InstanceKlass*>(this);
1302 while (klass != NULL) {
1303 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1304 return true;
1305 }
1306 klass = klass->super();
1307 }
1308 return false;
1309 }
1310
1311
1312 void InstanceKlass::methods_do(void f(Method* method)) {
1313 int len = methods()->length();
1314 for (int index = 0; index < len; index++) {
1315 Method* m = methods()->at(index);
1316 assert(m->is_method(), "must be method");
1317 f(m);
1318 }
1319 }
1320
1321
1322 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1323 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1324 if (fs.access_flags().is_static()) {
1325 fieldDescriptor& fd = fs.field_descriptor();
1326 cl->do_field(&fd);
1327 }
1328 }
1329 }
1330
1331
1332 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
1333 instanceKlassHandle h_this(THREAD, this);
1334 do_local_static_fields_impl(h_this, f, CHECK);
1335 }
1336
1337
1338 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
1339 for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
1340 if (fs.access_flags().is_static()) {
1341 fieldDescriptor& fd = fs.field_descriptor();
1342 f(&fd, CHECK);
1343 }
1344 }
1345 }
1346
1347
1348 static int compare_fields_by_offset(int* a, int* b) {
1349 return a[0] - b[0];
1350 }
1351
1352 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1353 InstanceKlass* super = superklass();
1354 if (super != NULL) {
1355 super->do_nonstatic_fields(cl);
1356 }
1357 fieldDescriptor fd;
1358 int length = java_fields_count();
1359 // In DebugInfo nonstatic fields are sorted by offset.
1360 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1361 int j = 0;
1362 for (int i = 0; i < length; i += 1) {
1363 fd.reinitialize(this, i);
1364 if (!fd.is_static()) {
1365 fields_sorted[j + 0] = fd.offset();
1366 fields_sorted[j + 1] = i;
1367 j += 2;
1368 }
1369 }
1370 if (j > 0) {
1371 length = j;
1372 // _sort_Fn is defined in growableArray.hpp.
1373 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1374 for (int i = 0; i < length; i += 2) {
1375 fd.reinitialize(this, fields_sorted[i + 1]);
1376 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1377 cl->do_field(&fd);
1378 }
1379 }
1380 FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
1381 }
1382
1383
1384 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1385 if (array_klasses() != NULL)
1386 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1387 }
1388
1389 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1390 if (array_klasses() != NULL)
1391 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1392 }
1393
1394 #ifdef ASSERT
1395 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
1396 int len = methods->length();
1397 for (int index = 0; index < len; index++) {
1398 Method* m = methods->at(index);
1399 assert(m->is_method(), "must be method");
1400 if (m->signature() == signature && m->name() == name) {
1401 return index;
1402 }
1403 }
1404 return -1;
1405 }
1406 #endif
1407
1408 static int binary_search(Array<Method*>* methods, Symbol* name) {
1409 int len = methods->length();
1410 // methods are sorted, so do binary search
1411 int l = 0;
1412 int h = len - 1;
1413 while (l <= h) {
1414 int mid = (l + h) >> 1;
1415 Method* m = methods->at(mid);
1416 assert(m->is_method(), "must be method");
1417 int res = m->name()->fast_compare(name);
1418 if (res == 0) {
1419 return mid;
1420 } else if (res < 0) {
1421 l = mid + 1;
1422 } else {
1423 h = mid - 1;
1424 }
1425 }
1426 return -1;
1427 }
1428
1429 // find_method looks up the name/signature in the local methods array
1430 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
1431 return InstanceKlass::find_method(methods(), name, signature);
1432 }
1433
1434 // find_instance_method looks up the name/signature in the local methods array
1435 // and skips over static methods
1436 Method* InstanceKlass::find_instance_method(
1437 Array<Method*>* methods, Symbol* name, Symbol* signature) {
1438 Method* meth = InstanceKlass::find_method(methods, name, signature);
1439 if (meth != NULL && meth->is_static()) {
1440 meth = NULL;
1441 }
1442 return meth;
1443 }
1444
1445 // find_method looks up the name/signature in the local methods array
1446 Method* InstanceKlass::find_method(
1447 Array<Method*>* methods, Symbol* name, Symbol* signature) {
1448 int hit = find_method_index(methods, name, signature);
1449 return hit >= 0 ? methods->at(hit): NULL;
1450 }
1451
1452 // Used directly for default_methods to find the index into the
1453 // default_vtable_indices, and indirectly by find_method
1454 // find_method_index looks in the local methods array to return the index
1455 // of the matching name/signature
1456 int InstanceKlass::find_method_index(
1457 Array<Method*>* methods, Symbol* name, Symbol* signature) {
1458 int hit = binary_search(methods, name);
1459 if (hit != -1) {
1460 Method* m = methods->at(hit);
1461 // Do linear search to find matching signature. First, quick check
1462 // for common case
1463 if (m->signature() == signature) return hit;
1464 // search downwards through overloaded methods
1465 int i;
1466 for (i = hit - 1; i >= 0; --i) {
1467 Method* m = methods->at(i);
1468 assert(m->is_method(), "must be method");
1469 if (m->name() != name) break;
1470 if (m->signature() == signature) return i;
1471 }
1472 // search upwards
1473 for (i = hit + 1; i < methods->length(); ++i) {
1474 Method* m = methods->at(i);
1475 assert(m->is_method(), "must be method");
1476 if (m->name() != name) break;
1477 if (m->signature() == signature) return i;
1478 }
1479 // not found
1480 #ifdef ASSERT
1481 int index = linear_search(methods, name, signature);
1482 assert(index == -1, err_msg("binary search should have found entry %d", index));
1483 #endif
1484 }
1485 return -1;
1486 }
1487 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
1488 return find_method_by_name(methods(), name, end);
1489 }
1490
1491 int InstanceKlass::find_method_by_name(
1492 Array<Method*>* methods, Symbol* name, int* end_ptr) {
1493 assert(end_ptr != NULL, "just checking");
1494 int start = binary_search(methods, name);
1495 int end = start + 1;
1496 if (start != -1) {
1497 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1498 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1499 *end_ptr = end;
1500 return start;
1501 }
1502 return -1;
1503 }
1504
1505 // uncached_lookup_method searches both the local class methods array and all
1506 // superclasses methods arrays, skipping any overpass methods in superclasses.
1507 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
1508 Klass* klass = const_cast<InstanceKlass*>(this);
1509 bool dont_ignore_overpasses = true; // For the class being searched, find its overpasses.
1510 while (klass != NULL) {
1511 Method* method = InstanceKlass::cast(klass)->find_method(name, signature);
1512 if ((method != NULL) && (dont_ignore_overpasses || !method->is_overpass())) {
1513 return method;
1514 }
1515 klass = InstanceKlass::cast(klass)->super();
1516 dont_ignore_overpasses = false; // Ignore overpass methods in all superclasses.
1517 }
1518 return NULL;
1519 }
1520
1521 // lookup a method in the default methods list then in all transitive interfaces
1522 // Do NOT return private or static methods
1523 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1524 Symbol* signature) const {
1525 Method* m = NULL;
1526 if (default_methods() != NULL) {
1527 m = find_method(default_methods(), name, signature);
1528 }
1529 // Look up interfaces
1530 if (m == NULL) {
1531 m = lookup_method_in_all_interfaces(name, signature, false);
1532 }
1533 return m;
1534 }
1535
1536 // lookup a method in all the interfaces that this class implements
1537 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1538 // They should only be found in the initial InterfaceMethodRef
1539 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1540 Symbol* signature,
1541 bool skip_default_methods) const {
1542 Array<Klass*>* all_ifs = transitive_interfaces();
1543 int num_ifs = all_ifs->length();
1544 InstanceKlass *ik = NULL;
1545 for (int i = 0; i < num_ifs; i++) {
1546 ik = InstanceKlass::cast(all_ifs->at(i));
1547 Method* m = ik->lookup_method(name, signature);
1548 if (m != NULL && m->is_public() && !m->is_static() &&
1549 (!skip_default_methods || !m->is_default_method())) {
1550 return m;
1551 }
1552 }
1553 return NULL;
1554 }
1555
1556 /* jni_id_for_impl for jfieldIds only */
1557 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
1558 MutexLocker ml(JfieldIdCreation_lock);
1559 // Retry lookup after we got the lock
1560 JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
1561 if (probe == NULL) {
1562 // Slow case, allocate new static field identifier
1563 probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
1564 this_oop->set_jni_ids(probe);
1565 }
1566 return probe;
1567 }
1568
1569
1570 /* jni_id_for for jfieldIds only */
1571 JNIid* InstanceKlass::jni_id_for(int offset) {
1572 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1573 if (probe == NULL) {
1574 probe = jni_id_for_impl(this, offset);
1575 }
1576 return probe;
1577 }
1578
1579 u2 InstanceKlass::enclosing_method_data(int offset) {
1580 Array<jushort>* inner_class_list = inner_classes();
1581 if (inner_class_list == NULL) {
1582 return 0;
1583 }
1584 int length = inner_class_list->length();
1585 if (length % inner_class_next_offset == 0) {
1586 return 0;
1587 } else {
1588 int index = length - enclosing_method_attribute_size;
1589 assert(offset < enclosing_method_attribute_size, "invalid offset");
1590 return inner_class_list->at(index + offset);
1591 }
1592 }
1593
1594 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1595 u2 method_index) {
1596 Array<jushort>* inner_class_list = inner_classes();
1597 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1598 int length = inner_class_list->length();
1599 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1600 int index = length - enclosing_method_attribute_size;
1601 inner_class_list->at_put(
1602 index + enclosing_method_class_index_offset, class_index);
1603 inner_class_list->at_put(
1604 index + enclosing_method_method_index_offset, method_index);
1605 }
1606 }
1607
1608 // Lookup or create a jmethodID.
1609 // This code is called by the VMThread and JavaThreads so the
1610 // locking has to be done very carefully to avoid deadlocks
1611 // and/or other cache consistency problems.
1612 //
1613 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1614 size_t idnum = (size_t)method_h->method_idnum();
1615 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1616 size_t length = 0;
1617 jmethodID id = NULL;
1618
1619 // We use a double-check locking idiom here because this cache is
1620 // performance sensitive. In the normal system, this cache only
1621 // transitions from NULL to non-NULL which is safe because we use
1622 // release_set_methods_jmethod_ids() to advertise the new cache.
1623 // A partially constructed cache should never be seen by a racing
1624 // thread. We also use release_store_ptr() to save a new jmethodID
1625 // in the cache so a partially constructed jmethodID should never be
1626 // seen either. Cache reads of existing jmethodIDs proceed without a
1627 // lock, but cache writes of a new jmethodID requires uniqueness and
1628 // creation of the cache itself requires no leaks so a lock is
1629 // generally acquired in those two cases.
1630 //
1631 // If the RedefineClasses() API has been used, then this cache can
1632 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1633 // Cache creation requires no leaks and we require safety between all
1634 // cache accesses and freeing of the old cache so a lock is generally
1635 // acquired when the RedefineClasses() API has been used.
1636
1637 if (jmeths != NULL) {
1638 // the cache already exists
1639 if (!ik_h->idnum_can_increment()) {
1640 // the cache can't grow so we can just get the current values
1641 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1642 } else {
1643 // cache can grow so we have to be more careful
1644 if (Threads::number_of_threads() == 0 ||
1645 SafepointSynchronize::is_at_safepoint()) {
1646 // we're single threaded or at a safepoint - no locking needed
1647 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1648 } else {
1649 MutexLocker ml(JmethodIdCreation_lock);
1650 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1651 }
1652 }
1653 }
1654 // implied else:
1655 // we need to allocate a cache so default length and id values are good
1656
1657 if (jmeths == NULL || // no cache yet
1658 length <= idnum || // cache is too short
1659 id == NULL) { // cache doesn't contain entry
1660
1661 // This function can be called by the VMThread so we have to do all
1662 // things that might block on a safepoint before grabbing the lock.
1663 // Otherwise, we can deadlock with the VMThread or have a cache
1664 // consistency issue. These vars keep track of what we might have
1665 // to free after the lock is dropped.
1666 jmethodID to_dealloc_id = NULL;
1667 jmethodID* to_dealloc_jmeths = NULL;
1668
1669 // may not allocate new_jmeths or use it if we allocate it
1670 jmethodID* new_jmeths = NULL;
1671 if (length <= idnum) {
1672 // allocate a new cache that might be used
1673 size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1674 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1675 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1676 // cache size is stored in element[0], other elements offset by one
1677 new_jmeths[0] = (jmethodID)size;
1678 }
1679
1680 // allocate a new jmethodID that might be used
1681 jmethodID new_id = NULL;
1682 if (method_h->is_old() && !method_h->is_obsolete()) {
1683 // The method passed in is old (but not obsolete), we need to use the current version
1684 Method* current_method = ik_h->method_with_idnum((int)idnum);
1685 assert(current_method != NULL, "old and but not obsolete, so should exist");
1686 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
1687 } else {
1688 // It is the current version of the method or an obsolete method,
1689 // use the version passed in
1690 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
1691 }
1692
1693 if (Threads::number_of_threads() == 0 ||
1694 SafepointSynchronize::is_at_safepoint()) {
1695 // we're single threaded or at a safepoint - no locking needed
1696 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1697 &to_dealloc_id, &to_dealloc_jmeths);
1698 } else {
1699 MutexLocker ml(JmethodIdCreation_lock);
1700 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1701 &to_dealloc_id, &to_dealloc_jmeths);
1702 }
1703
1704 // The lock has been dropped so we can free resources.
1705 // Free up either the old cache or the new cache if we allocated one.
1706 if (to_dealloc_jmeths != NULL) {
1707 FreeHeap(to_dealloc_jmeths);
1708 }
1709 // free up the new ID since it wasn't needed
1710 if (to_dealloc_id != NULL) {
1711 Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
1712 }
1713 }
1714 return id;
1715 }
1716
1717
1718 // Common code to fetch the jmethodID from the cache or update the
1719 // cache with the new jmethodID. This function should never do anything
1720 // that causes the caller to go to a safepoint or we can deadlock with
1721 // the VMThread or have cache consistency issues.
1722 //
1723 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1724 instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1725 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1726 jmethodID** to_dealloc_jmeths_p) {
1727 assert(new_id != NULL, "sanity check");
1728 assert(to_dealloc_id_p != NULL, "sanity check");
1729 assert(to_dealloc_jmeths_p != NULL, "sanity check");
1730 assert(Threads::number_of_threads() == 0 ||
1731 SafepointSynchronize::is_at_safepoint() ||
1732 JmethodIdCreation_lock->owned_by_self(), "sanity check");
1733
1734 // reacquire the cache - we are locked, single threaded or at a safepoint
1735 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1736 jmethodID id = NULL;
1737 size_t length = 0;
1738
1739 if (jmeths == NULL || // no cache yet
1740 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
1741 if (jmeths != NULL) {
1742 // copy any existing entries from the old cache
1743 for (size_t index = 0; index < length; index++) {
1744 new_jmeths[index+1] = jmeths[index+1];
1745 }
1746 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
1747 }
1748 ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1749 } else {
1750 // fetch jmethodID (if any) from the existing cache
1751 id = jmeths[idnum+1];
1752 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
1753 }
1754 if (id == NULL) {
1755 // No matching jmethodID in the existing cache or we have a new
1756 // cache or we just grew the cache. This cache write is done here
1757 // by the first thread to win the foot race because a jmethodID
1758 // needs to be unique once it is generally available.
1759 id = new_id;
1760
1761 // The jmethodID cache can be read while unlocked so we have to
1762 // make sure the new jmethodID is complete before installing it
1763 // in the cache.
1764 OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1765 } else {
1766 *to_dealloc_id_p = new_id; // save new id for later delete
1767 }
1768 return id;
1769 }
1770
1771
1772 // Common code to get the jmethodID cache length and the jmethodID
1773 // value at index idnum if there is one.
1774 //
1775 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1776 size_t idnum, size_t *length_p, jmethodID* id_p) {
1777 assert(cache != NULL, "sanity check");
1778 assert(length_p != NULL, "sanity check");
1779 assert(id_p != NULL, "sanity check");
1780
1781 // cache size is stored in element[0], other elements offset by one
1782 *length_p = (size_t)cache[0];
1783 if (*length_p <= idnum) { // cache is too short
1784 *id_p = NULL;
1785 } else {
1786 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
1787 }
1788 }
1789
1790
1791 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
1792 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1793 size_t idnum = (size_t)method->method_idnum();
1794 jmethodID* jmeths = methods_jmethod_ids_acquire();
1795 size_t length; // length assigned as debugging crumb
1796 jmethodID id = NULL;
1797 if (jmeths != NULL && // If there is a cache
1798 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
1799 id = jmeths[idnum+1]; // Look up the id (may be NULL)
1800 }
1801 return id;
1802 }
1803
1804
1805 //
1806 // Walk the list of dependent nmethods searching for nmethods which
1807 // are dependent on the changes that were passed in and mark them for
1808 // deoptimization. Returns the number of nmethods found.
1809 //
1810 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
1811 assert_locked_or_safepoint(CodeCache_lock);
1812 int found = 0;
1813 nmethodBucket* b = _dependencies;
1814 while (b != NULL) {
1815 nmethod* nm = b->get_nmethod();
1816 // since dependencies aren't removed until an nmethod becomes a zombie,
1817 // the dependency list may contain nmethods which aren't alive.
1818 if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1819 if (TraceDependencies) {
1820 ResourceMark rm;
1821 tty->print_cr("Marked for deoptimization");
1822 tty->print_cr(" context = %s", this->external_name());
1823 changes.print();
1824 nm->print();
1825 nm->print_dependencies();
1826 }
1827 nm->mark_for_deoptimization();
1828 found++;
1829 }
1830 b = b->next();
1831 }
1832 return found;
1833 }
1834
1835
1836 //
1837 // Add an nmethodBucket to the list of dependencies for this nmethod.
1838 // It's possible that an nmethod has multiple dependencies on this klass
1839 // so a count is kept for each bucket to guarantee that creation and
1840 // deletion of dependencies is consistent.
1841 //
1842 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1843 assert_locked_or_safepoint(CodeCache_lock);
1844 nmethodBucket* b = _dependencies;
1845 nmethodBucket* last = NULL;
1846 while (b != NULL) {
1847 if (nm == b->get_nmethod()) {
1848 b->increment();
1849 return;
1850 }
1851 b = b->next();
1852 }
1853 _dependencies = new nmethodBucket(nm, _dependencies);
1854 }
1855
1856
1857 //
1858 // Decrement count of the nmethod in the dependency list and remove
1859 // the bucket competely when the count goes to 0. This method must
1860 // find a corresponding bucket otherwise there's a bug in the
1861 // recording of dependecies.
1862 //
1863 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
1864 assert_locked_or_safepoint(CodeCache_lock);
1865 nmethodBucket* b = _dependencies;
1866 nmethodBucket* last = NULL;
1867 while (b != NULL) {
1868 if (nm == b->get_nmethod()) {
1869 if (b->decrement() == 0) {
1870 if (last == NULL) {
1871 _dependencies = b->next();
1872 } else {
1873 last->set_next(b->next());
1874 }
1875 delete b;
1876 }
1877 return;
1878 }
1879 last = b;
1880 b = b->next();
1881 }
1882 #ifdef ASSERT
1883 tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1884 nm->print();
1885 #endif // ASSERT
1886 ShouldNotReachHere();
1887 }
1888
1889
1890 #ifndef PRODUCT
1891 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1892 nmethodBucket* b = _dependencies;
1893 int idx = 0;
1894 while (b != NULL) {
1895 nmethod* nm = b->get_nmethod();
1896 tty->print("[%d] count=%d { ", idx++, b->count());
1897 if (!verbose) {
1898 nm->print_on(tty, "nmethod");
1899 tty->print_cr(" } ");
1900 } else {
1901 nm->print();
1902 nm->print_dependencies();
1903 tty->print_cr("--- } ");
1904 }
1905 b = b->next();
1906 }
1907 }
1908
1909
1910 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1911 nmethodBucket* b = _dependencies;
1912 while (b != NULL) {
1913 if (nm == b->get_nmethod()) {
1914 return true;
1915 }
1916 b = b->next();
1917 }
1918 return false;
1919 }
1920 #endif //PRODUCT
1921
1922
1923 // Garbage collection
1924
1925 #ifdef ASSERT
1926 template <class T> void assert_is_in(T *p) {
1927 T heap_oop = oopDesc::load_heap_oop(p);
1928 if (!oopDesc::is_null(heap_oop)) {
1929 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1930 assert(Universe::heap()->is_in(o), "should be in heap");
1931 }
1932 }
1933 template <class T> void assert_is_in_closed_subset(T *p) {
1934 T heap_oop = oopDesc::load_heap_oop(p);
1935 if (!oopDesc::is_null(heap_oop)) {
1936 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1937 assert(Universe::heap()->is_in_closed_subset(o),
1938 err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
1939 }
1940 }
1941 template <class T> void assert_is_in_reserved(T *p) {
1942 T heap_oop = oopDesc::load_heap_oop(p);
1943 if (!oopDesc::is_null(heap_oop)) {
1944 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1945 assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
1946 }
1947 }
1948 template <class T> void assert_nothing(T *p) {}
1949
1950 #else
1951 template <class T> void assert_is_in(T *p) {}
1952 template <class T> void assert_is_in_closed_subset(T *p) {}
1953 template <class T> void assert_is_in_reserved(T *p) {}
1954 template <class T> void assert_nothing(T *p) {}
1955 #endif // ASSERT
1956
1957 //
1958 // Macros that iterate over areas of oops which are specialized on type of
1959 // oop pointer either narrow or wide, depending on UseCompressedOops
1960 //
1961 // Parameters are:
1962 // T - type of oop to point to (either oop or narrowOop)
1963 // start_p - starting pointer for region to iterate over
1964 // count - number of oops or narrowOops to iterate over
1965 // do_oop - action to perform on each oop (it's arbitrary C code which
1966 // makes it more efficient to put in a macro rather than making
1967 // it a template function)
1968 // assert_fn - assert function which is template function because performance
1969 // doesn't matter when enabled.
1970 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
1971 T, start_p, count, do_oop, \
1972 assert_fn) \
1973 { \
1974 T* p = (T*)(start_p); \
1975 T* const end = p + (count); \
1976 while (p < end) { \
1977 (assert_fn)(p); \
1978 do_oop; \
1979 ++p; \
1980 } \
1981 }
1982
1983 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
1984 T, start_p, count, do_oop, \
1985 assert_fn) \
1986 { \
1987 T* const start = (T*)(start_p); \
1988 T* p = start + (count); \
1989 while (start < p) { \
1990 --p; \
1991 (assert_fn)(p); \
1992 do_oop; \
1993 } \
1994 }
1995
1996 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
1997 T, start_p, count, low, high, \
1998 do_oop, assert_fn) \
1999 { \
2000 T* const l = (T*)(low); \
2001 T* const h = (T*)(high); \
2002 assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
2003 mask_bits((intptr_t)h, sizeof(T)-1) == 0, \
2004 "bounded region must be properly aligned"); \
2005 T* p = (T*)(start_p); \
2006 T* end = p + (count); \
2007 if (p < l) p = l; \
2008 if (end > h) end = h; \
2009 while (p < end) { \
2010 (assert_fn)(p); \
2011 do_oop; \
2012 ++p; \
2013 } \
2014 }
2015
2016
2017 // The following macros call specialized macros, passing either oop or
2018 // narrowOop as the specialization type. These test the UseCompressedOops
2019 // flag.
2020 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \
2021 { \
2022 /* Compute oopmap block range. The common case \
2023 is nonstatic_oop_map_size == 1. */ \
2024 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
2025 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
2026 if (UseCompressedOops) { \
2027 while (map < end_map) { \
2028 InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
2029 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
2030 do_oop, assert_fn) \
2031 ++map; \
2032 } \
2033 } else { \
2034 while (map < end_map) { \
2035 InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
2036 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2037 do_oop, assert_fn) \
2038 ++map; \
2039 } \
2040 } \
2041 }
2042
2043 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \
2044 { \
2045 OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \
2046 OopMapBlock* map = start_map + nonstatic_oop_map_count(); \
2047 if (UseCompressedOops) { \
2048 while (start_map < map) { \
2049 --map; \
2050 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \
2051 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
2052 do_oop, assert_fn) \
2053 } \
2054 } else { \
2055 while (start_map < map) { \
2056 --map; \
2057 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \
2058 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2059 do_oop, assert_fn) \
2060 } \
2061 } \
2062 }
2063
2064 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \
2065 assert_fn) \
2066 { \
2067 /* Compute oopmap block range. The common case is \
2068 nonstatic_oop_map_size == 1, so we accept the \
2069 usually non-existent extra overhead of examining \
2070 all the maps. */ \
2071 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
2072 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
2073 if (UseCompressedOops) { \
2074 while (map < end_map) { \
2075 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
2076 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
2077 low, high, \
2078 do_oop, assert_fn) \
2079 ++map; \
2080 } \
2081 } else { \
2082 while (map < end_map) { \
2083 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
2084 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2085 low, high, \
2086 do_oop, assert_fn) \
2087 ++map; \
2088 } \
2089 } \
2090 }
2091
2092 void InstanceKlass::oop_follow_contents(oop obj) {
2093 assert(obj != NULL, "can't follow the content of NULL object");
2094 MarkSweep::follow_klass(obj->klass());
2095 InstanceKlass_OOP_MAP_ITERATE( \
2096 obj, \
2097 MarkSweep::mark_and_push(p), \
2098 assert_is_in_closed_subset)
2099 }
2100
2101 #if INCLUDE_ALL_GCS
2102 void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
2103 oop obj) {
2104 assert(obj != NULL, "can't follow the content of NULL object");
2105 PSParallelCompact::follow_klass(cm, obj->klass());
2106 // Only mark the header and let the scan of the meta-data mark
2107 // everything else.
2108 InstanceKlass_OOP_MAP_ITERATE( \
2109 obj, \
2110 PSParallelCompact::mark_and_push(cm, p), \
2111 assert_is_in)
2112 }
2113 #endif // INCLUDE_ALL_GCS
2114
2115 // closure's do_metadata() method dictates whether the given closure should be
2116 // applied to the klass ptr in the object header.
2117
2118 #define if_do_metadata_checked(closure, nv_suffix) \
2119 /* Make sure the non-virtual and the virtual versions match. */ \
2120 assert(closure->do_metadata##nv_suffix() == closure->do_metadata(), \
2121 "Inconsistency in do_metadata"); \
2122 if (closure->do_metadata##nv_suffix())
2123
2124 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
2125 \
2126 int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
2127 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2128 /* header */ \
2129 if_do_metadata_checked(closure, nv_suffix) { \
2130 closure->do_klass##nv_suffix(obj->klass()); \
2131 } \
2132 InstanceKlass_OOP_MAP_ITERATE( \
2133 obj, \
2134 SpecializationStats:: \
2135 record_do_oop_call##nv_suffix(SpecializationStats::ik); \
2136 (closure)->do_oop##nv_suffix(p), \
2137 assert_is_in_closed_subset) \
2138 return size_helper(); \
2139 }
2140
2141 #if INCLUDE_ALL_GCS
2142 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
2143 \
2144 int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \
2145 OopClosureType* closure) { \
2146 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
2147 /* header */ \
2148 if_do_metadata_checked(closure, nv_suffix) { \
2149 closure->do_klass##nv_suffix(obj->klass()); \
2150 } \
2151 /* instance variables */ \
2152 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2153 obj, \
2154 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
2155 (closure)->do_oop##nv_suffix(p), \
2156 assert_is_in_closed_subset) \
2157 return size_helper(); \
2158 }
2159 #endif // INCLUDE_ALL_GCS
2160
2161 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
2162 \
2163 int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \
2164 OopClosureType* closure, \
2165 MemRegion mr) { \
2166 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2167 if_do_metadata_checked(closure, nv_suffix) { \
2168 if (mr.contains(obj)) { \
2169 closure->do_klass##nv_suffix(obj->klass()); \
2170 } \
2171 } \
2172 InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
2173 obj, mr.start(), mr.end(), \
2174 (closure)->do_oop##nv_suffix(p), \
2175 assert_is_in_closed_subset) \
2176 return size_helper(); \
2177 }
2178
2179 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2180 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2181 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2182 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2183 #if INCLUDE_ALL_GCS
2184 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2185 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2186 #endif // INCLUDE_ALL_GCS
2187
2188 int InstanceKlass::oop_adjust_pointers(oop obj) {
2189 int size = size_helper();
2190 InstanceKlass_OOP_MAP_ITERATE( \
2191 obj, \
2192 MarkSweep::adjust_pointer(p), \
2193 assert_is_in)
2194 return size;
2195 }
2196
2197 #if INCLUDE_ALL_GCS
2198 void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
2199 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2200 obj, \
2201 if (PSScavenge::should_scavenge(p)) { \
2202 pm->claim_or_forward_depth(p); \
2203 }, \
2204 assert_nothing )
2205 }
2206
2207 int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
2208 int size = size_helper();
2209 InstanceKlass_OOP_MAP_ITERATE( \
2210 obj, \
2211 PSParallelCompact::adjust_pointer(p), \
2212 assert_is_in)
2213 return size;
2214 }
2215
2216 #endif // INCLUDE_ALL_GCS
2217
2218 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
2219 assert(is_loader_alive(is_alive), "this klass should be live");
2220 if (is_interface()) {
2221 if (ClassUnloading) {
2222 Klass* impl = implementor();
2223 if (impl != NULL) {
2224 if (!impl->is_loader_alive(is_alive)) {
2225 // remove this guy
2226 Klass** klass = adr_implementor();
2227 assert(klass != NULL, "null klass");
2228 if (klass != NULL) {
2229 *klass = NULL;
2230 }
2231 }
2232 }
2233 }
2234 }
2235 }
2236
2237 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
2238 for (int m = 0; m < methods()->length(); m++) {
2239 MethodData* mdo = methods()->at(m)->method_data();
2240 if (mdo != NULL) {
2241 for (ProfileData* data = mdo->first_data();
2242 mdo->is_valid(data);
2243 data = mdo->next_data(data)) {
2244 data->clean_weak_klass_links(is_alive);
2245 }
2246 ParametersTypeData* parameters = mdo->parameters_type_data();
2247 if (parameters != NULL) {
2248 parameters->clean_weak_klass_links(is_alive);
2249 }
2250 }
2251 }
2252 }
2253
2254
2255 static void remove_unshareable_in_class(Klass* k) {
2256 // remove klass's unshareable info
2257 k->remove_unshareable_info();
2258 }
2259
2260 void InstanceKlass::remove_unshareable_info() {
2261 Klass::remove_unshareable_info();
2262 // Unlink the class
2263 if (is_linked()) {
2264 unlink_class();
2265 }
2266 init_implementor();
2267
2268 constants()->remove_unshareable_info();
2269
2270 for (int i = 0; i < methods()->length(); i++) {
2271 Method* m = methods()->at(i);
2272 m->remove_unshareable_info();
2273 }
2274
2275 // do array classes also.
2276 array_klasses_do(remove_unshareable_in_class);
2277 }
2278
2279 void restore_unshareable_in_class(Klass* k, TRAPS) {
2280 k->restore_unshareable_info(CHECK);
2281 }
2282
2283 void InstanceKlass::restore_unshareable_info(TRAPS) {
2284 Klass::restore_unshareable_info(CHECK);
2285 instanceKlassHandle ik(THREAD, this);
2286
2287 Array<Method*>* methods = ik->methods();
2288 int num_methods = methods->length();
2289 for (int index2 = 0; index2 < num_methods; ++index2) {
2290 methodHandle m(THREAD, methods->at(index2));
2291 m()->link_method(m, CHECK);
2292 // restore method's vtable by calling a virtual function
2293 m->restore_vtable();
2294 }
2295 if (JvmtiExport::has_redefined_a_class()) {
2296 // Reinitialize vtable because RedefineClasses may have changed some
2297 // entries in this vtable for super classes so the CDS vtable might
2298 // point to old or obsolete entries. RedefineClasses doesn't fix up
2299 // vtables in the shared system dictionary, only the main one.
2300 // It also redefines the itable too so fix that too.
2301 ResourceMark rm(THREAD);
2302 ik->vtable()->initialize_vtable(false, CHECK);
2303 ik->itable()->initialize_itable(false, CHECK);
2304 }
2305
2306 // restore constant pool resolved references
2307 ik->constants()->restore_unshareable_info(CHECK);
2308
2309 ik->array_klasses_do(restore_unshareable_in_class, CHECK);
2310 }
2311
2312 static void clear_all_breakpoints(Method* m) {
2313 m->clear_all_breakpoints();
2314 }
2315
2316
2317 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2318 // notify the debugger
2319 if (JvmtiExport::should_post_class_unload()) {
2320 JvmtiExport::post_class_unload(ik);
2321 }
2322
2323 // notify ClassLoadingService of class unload
2324 ClassLoadingService::notify_class_unloaded(ik);
2325 }
2326
2327 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2328 // Clean up C heap
2329 ik->release_C_heap_structures();
2330 ik->constants()->release_C_heap_structures();
2331 }
2332
2333 void InstanceKlass::release_C_heap_structures() {
2334
2335 // Can't release the constant pool here because the constant pool can be
2336 // deallocated separately from the InstanceKlass for default methods and
2337 // redefine classes.
2338
2339 // Deallocate oop map cache
2340 if (_oop_map_cache != NULL) {
2341 delete _oop_map_cache;
2342 _oop_map_cache = NULL;
2343 }
2344
2345 // Deallocate JNI identifiers for jfieldIDs
2346 JNIid::deallocate(jni_ids());
2347 set_jni_ids(NULL);
2348
2349 jmethodID* jmeths = methods_jmethod_ids_acquire();
2350 if (jmeths != (jmethodID*)NULL) {
2351 release_set_methods_jmethod_ids(NULL);
2352 FreeHeap(jmeths);
2353 }
2354
2355 // Deallocate MemberNameTable
2356 {
2357 Mutex* lock_or_null = SafepointSynchronize::is_at_safepoint() ? NULL : MemberNameTable_lock;
2358 MutexLockerEx ml(lock_or_null, Mutex::_no_safepoint_check_flag);
2359 MemberNameTable* mnt = member_names();
2360 if (mnt != NULL) {
2361 delete mnt;
2362 set_member_names(NULL);
2363 }
2364 }
2365
2366 // release dependencies
2367 nmethodBucket* b = _dependencies;
2368 _dependencies = NULL;
2369 while (b != NULL) {
2370 nmethodBucket* next = b->next();
2371 delete b;
2372 b = next;
2373 }
2374
2375 // Deallocate breakpoint records
2376 if (breakpoints() != 0x0) {
2377 methods_do(clear_all_breakpoints);
2378 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2379 }
2380
2381 // deallocate information about previous versions
2382 if (_previous_versions != NULL) {
2383 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
2384 PreviousVersionNode * pv_node = _previous_versions->at(i);
2385 delete pv_node;
2386 }
2387 delete _previous_versions;
2388 _previous_versions = NULL;
2389 }
2390
2391 // deallocate the cached class file
2392 if (_cached_class_file != NULL) {
2393 os::free(_cached_class_file, mtClass);
2394 _cached_class_file = NULL;
2395 }
2396
2397 // Decrement symbol reference counts associated with the unloaded class.
2398 if (_name != NULL) _name->decrement_refcount();
2399 // unreference array name derived from this class name (arrays of an unloaded
2400 // class can't be referenced anymore).
2401 if (_array_name != NULL) _array_name->decrement_refcount();
2402 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
2403
2404 assert(_total_instanceKlass_count >= 1, "Sanity check");
2405 Atomic::dec(&_total_instanceKlass_count);
2406 }
2407
2408 void InstanceKlass::set_source_debug_extension(char* array, int length) {
2409 if (array == NULL) {
2410 _source_debug_extension = NULL;
2411 } else {
2412 // Adding one to the attribute length in order to store a null terminator
2413 // character could cause an overflow because the attribute length is
2414 // already coded with an u4 in the classfile, but in practice, it's
2415 // unlikely to happen.
2416 assert((length+1) > length, "Overflow checking");
2417 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2418 for (int i = 0; i < length; i++) {
2419 sde[i] = array[i];
2420 }
2421 sde[length] = '\0';
2422 _source_debug_extension = sde;
2423 }
2424 }
2425
2426 address InstanceKlass::static_field_addr(int offset) {
2427 return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
2428 }
2429
2430
2431 const char* InstanceKlass::signature_name() const {
2432 int hash_len = 0;
2433 char hash_buf[40];
2434
2435 // If this is an anonymous class, append a hash to make the name unique
2436 if (is_anonymous()) {
2437 assert(EnableInvokeDynamic, "EnableInvokeDynamic was not set.");
2438 intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2439 sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
2440 hash_len = (int)strlen(hash_buf);
2441 }
2442
2443 // Get the internal name as a c string
2444 const char* src = (const char*) (name()->as_C_string());
2445 const int src_length = (int)strlen(src);
2446
2447 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2448
2449 // Add L as type indicator
2450 int dest_index = 0;
2451 dest[dest_index++] = 'L';
2452
2453 // Add the actual class name
2454 for (int src_index = 0; src_index < src_length; ) {
2455 dest[dest_index++] = src[src_index++];
2456 }
2457
2458 // If we have a hash, append it
2459 for (int hash_index = 0; hash_index < hash_len; ) {
2460 dest[dest_index++] = hash_buf[hash_index++];
2461 }
2462
2463 // Add the semicolon and the NULL
2464 dest[dest_index++] = ';';
2465 dest[dest_index] = '\0';
2466 return dest;
2467 }
2468
2469 // different verisons of is_same_class_package
2470 bool InstanceKlass::is_same_class_package(Klass* class2) {
2471 Klass* class1 = this;
2472 oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2473 Symbol* classname1 = class1->name();
2474
2475 if (class2->oop_is_objArray()) {
2476 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2477 }
2478 oop classloader2;
2479 if (class2->oop_is_instance()) {
2480 classloader2 = InstanceKlass::cast(class2)->class_loader();
2481 } else {
2482 assert(class2->oop_is_typeArray(), "should be type array");
2483 classloader2 = NULL;
2484 }
2485 Symbol* classname2 = class2->name();
2486
2487 return InstanceKlass::is_same_class_package(classloader1, classname1,
2488 classloader2, classname2);
2489 }
2490
2491 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
2492 Klass* class1 = this;
2493 oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2494 Symbol* classname1 = class1->name();
2495
2496 return InstanceKlass::is_same_class_package(classloader1, classname1,
2497 classloader2, classname2);
2498 }
2499
2500 // return true if two classes are in the same package, classloader
2501 // and classname information is enough to determine a class's package
2502 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
2503 oop class_loader2, Symbol* class_name2) {
2504 if (class_loader1 != class_loader2) {
2505 return false;
2506 } else if (class_name1 == class_name2) {
2507 return true; // skip painful bytewise comparison
2508 } else {
2509 ResourceMark rm;
2510
2511 // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
2512 // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
2513 // Otherwise, we just compare jbyte values between the strings.
2514 const jbyte *name1 = class_name1->base();
2515 const jbyte *name2 = class_name2->base();
2516
2517 const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
2518 const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
2519
2520 if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
2521 // One of the two doesn't have a package. Only return true
2522 // if the other one also doesn't have a package.
2523 return last_slash1 == last_slash2;
2524 } else {
2525 // Skip over '['s
2526 if (*name1 == '[') {
2527 do {
2528 name1++;
2529 } while (*name1 == '[');
2530 if (*name1 != 'L') {
2531 // Something is terribly wrong. Shouldn't be here.
2532 return false;
2533 }
2534 }
2535 if (*name2 == '[') {
2536 do {
2537 name2++;
2538 } while (*name2 == '[');
2539 if (*name2 != 'L') {
2540 // Something is terribly wrong. Shouldn't be here.
2541 return false;
2542 }
2543 }
2544
2545 // Check that package part is identical
2546 int length1 = last_slash1 - name1;
2547 int length2 = last_slash2 - name2;
2548
2549 return UTF8::equal(name1, length1, name2, length2);
2550 }
2551 }
2552 }
2553
2554 // Returns true iff super_method can be overridden by a method in targetclassname
2555 // See JSL 3rd edition 8.4.6.1
2556 // Assumes name-signature match
2557 // "this" is InstanceKlass of super_method which must exist
2558 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2559 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2560 // Private methods can not be overridden
2561 if (super_method->is_private()) {
2562 return false;
2563 }
2564 // If super method is accessible, then override
2565 if ((super_method->is_protected()) ||
2566 (super_method->is_public())) {
2567 return true;
2568 }
2569 // Package-private methods are not inherited outside of package
2570 assert(super_method->is_package_private(), "must be package private");
2571 return(is_same_class_package(targetclassloader(), targetclassname));
2572 }
2573
2574 /* defined for now in jvm.cpp, for historical reasons *--
2575 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2576 Symbol*& simple_name_result, TRAPS) {
2577 ...
2578 }
2579 */
2580
2581 // tell if two classes have the same enclosing class (at package level)
2582 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2583 Klass* class2_oop, TRAPS) {
2584 if (class2_oop == class1()) return true;
2585 if (!class2_oop->oop_is_instance()) return false;
2586 instanceKlassHandle class2(THREAD, class2_oop);
2587
2588 // must be in same package before we try anything else
2589 if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2590 return false;
2591
2592 // As long as there is an outer1.getEnclosingClass,
2593 // shift the search outward.
2594 instanceKlassHandle outer1 = class1;
2595 for (;;) {
2596 // As we walk along, look for equalities between outer1 and class2.
2597 // Eventually, the walks will terminate as outer1 stops
2598 // at the top-level class around the original class.
2599 bool ignore_inner_is_member;
2600 Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2601 CHECK_false);
2602 if (next == NULL) break;
2603 if (next == class2()) return true;
2604 outer1 = instanceKlassHandle(THREAD, next);
2605 }
2606
2607 // Now do the same for class2.
2608 instanceKlassHandle outer2 = class2;
2609 for (;;) {
2610 bool ignore_inner_is_member;
2611 Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2612 CHECK_false);
2613 if (next == NULL) break;
2614 // Might as well check the new outer against all available values.
2615 if (next == class1()) return true;
2616 if (next == outer1()) return true;
2617 outer2 = instanceKlassHandle(THREAD, next);
2618 }
2619
2620 // If by this point we have not found an equality between the
2621 // two classes, we know they are in separate package members.
2622 return false;
2623 }
2624
2625
2626 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2627 jint access = access_flags().as_int();
2628
2629 // But check if it happens to be member class.
2630 instanceKlassHandle ik(THREAD, this);
2631 InnerClassesIterator iter(ik);
2632 for (; !iter.done(); iter.next()) {
2633 int ioff = iter.inner_class_info_index();
2634 // Inner class attribute can be zero, skip it.
2635 // Strange but true: JVM spec. allows null inner class refs.
2636 if (ioff == 0) continue;
2637
2638 // only look at classes that are already loaded
2639 // since we are looking for the flags for our self.
2640 Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2641 if ((ik->name() == inner_name)) {
2642 // This is really a member class.
2643 access = iter.inner_access_flags();
2644 break;
2645 }
2646 }
2647 // Remember to strip ACC_SUPER bit
2648 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2649 }
2650
2651 jint InstanceKlass::jvmti_class_status() const {
2652 jint result = 0;
2653
2654 if (is_linked()) {
2655 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2656 }
2657
2658 if (is_initialized()) {
2659 assert(is_linked(), "Class status is not consistent");
2660 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2661 }
2662 if (is_in_error_state()) {
2663 result |= JVMTI_CLASS_STATUS_ERROR;
2664 }
2665 return result;
2666 }
2667
2668 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2669 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2670 int method_table_offset_in_words = ioe->offset()/wordSize;
2671 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2672 / itableOffsetEntry::size();
2673
2674 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2675 // If the interface isn't implemented by the receiver class,
2676 // the VM should throw IncompatibleClassChangeError.
2677 if (cnt >= nof_interfaces) {
2678 THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2679 }
2680
2681 Klass* ik = ioe->interface_klass();
2682 if (ik == holder) break;
2683 }
2684
2685 itableMethodEntry* ime = ioe->first_method_entry(this);
2686 Method* m = ime[index].method();
2687 if (m == NULL) {
2688 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2689 }
2690 return m;
2691 }
2692
2693
2694 #if INCLUDE_JVMTI
2695 // update default_methods for redefineclasses for methods that are
2696 // not yet in the vtable due to concurrent subclass define and superinterface
2697 // redefinition
2698 // Note: those in the vtable, should have been updated via adjust_method_entries
2699 void InstanceKlass::adjust_default_methods(Method** old_methods, Method** new_methods,
2700 int methods_length, bool* trace_name_printed) {
2701 // search the default_methods for uses of either obsolete or EMCP methods
2702 if (default_methods() != NULL) {
2703 for (int j = 0; j < methods_length; j++) {
2704 Method* old_method = old_methods[j];
2705 Method* new_method = new_methods[j];
2706
2707 for (int index = 0; index < default_methods()->length(); index ++) {
2708 if (default_methods()->at(index) == old_method) {
2709 default_methods()->at_put(index, new_method);
2710 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
2711 if (!(*trace_name_printed)) {
2712 // RC_TRACE_MESG macro has an embedded ResourceMark
2713 RC_TRACE_MESG(("adjust: klassname=%s default methods from name=%s",
2714 external_name(),
2715 old_method->method_holder()->external_name()));
2716 *trace_name_printed = true;
2717 }
2718 RC_TRACE(0x00100000, ("default method update: %s(%s) ",
2719 new_method->name()->as_C_string(),
2720 new_method->signature()->as_C_string()));
2721 }
2722 }
2723 }
2724 }
2725 }
2726 }
2727 #endif // INCLUDE_JVMTI
2728
2729 // On-stack replacement stuff
2730 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2731 // only one compilation can be active
2732 NEEDS_CLEANUP
2733 // This is a short non-blocking critical region, so the no safepoint check is ok.
2734 OsrList_lock->lock_without_safepoint_check();
2735 assert(n->is_osr_method(), "wrong kind of nmethod");
2736 n->set_osr_link(osr_nmethods_head());
2737 set_osr_nmethods_head(n);
2738 // Raise the highest osr level if necessary
2739 if (TieredCompilation) {
2740 Method* m = n->method();
2741 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2742 }
2743 // Remember to unlock again
2744 OsrList_lock->unlock();
2745
2746 // Get rid of the osr methods for the same bci that have lower levels.
2747 if (TieredCompilation) {
2748 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2749 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2750 if (inv != NULL && inv->is_in_use()) {
2751 inv->make_not_entrant();
2752 }
2753 }
2754 }
2755 }
2756
2757
2758 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
2759 // This is a short non-blocking critical region, so the no safepoint check is ok.
2760 OsrList_lock->lock_without_safepoint_check();
2761 assert(n->is_osr_method(), "wrong kind of nmethod");
2762 nmethod* last = NULL;
2763 nmethod* cur = osr_nmethods_head();
2764 int max_level = CompLevel_none; // Find the max comp level excluding n
2765 Method* m = n->method();
2766 // Search for match
2767 while(cur != NULL && cur != n) {
2768 if (TieredCompilation) {
2769 // Find max level before n
2770 max_level = MAX2(max_level, cur->comp_level());
2771 }
2772 last = cur;
2773 cur = cur->osr_link();
2774 }
2775 nmethod* next = NULL;
2776 if (cur == n) {
2777 next = cur->osr_link();
2778 if (last == NULL) {
2779 // Remove first element
2780 set_osr_nmethods_head(next);
2781 } else {
2782 last->set_osr_link(next);
2783 }
2784 }
2785 n->set_osr_link(NULL);
2786 if (TieredCompilation) {
2787 cur = next;
2788 while (cur != NULL) {
2789 // Find max level after n
2790 max_level = MAX2(max_level, cur->comp_level());
2791 cur = cur->osr_link();
2792 }
2793 m->set_highest_osr_comp_level(max_level);
2794 }
2795 // Remember to unlock again
2796 OsrList_lock->unlock();
2797 }
2798
2799 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2800 // This is a short non-blocking critical region, so the no safepoint check is ok.
2801 OsrList_lock->lock_without_safepoint_check();
2802 nmethod* osr = osr_nmethods_head();
2803 nmethod* best = NULL;
2804 while (osr != NULL) {
2805 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2806 // There can be a time when a c1 osr method exists but we are waiting
2807 // for a c2 version. When c2 completes its osr nmethod we will trash
2808 // the c1 version and only be able to find the c2 version. However
2809 // while we overflow in the c1 code at back branches we don't want to
2810 // try and switch to the same code as we are already running
2811
2812 if (osr->method() == m &&
2813 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2814 if (match_level) {
2815 if (osr->comp_level() == comp_level) {
2816 // Found a match - return it.
2817 OsrList_lock->unlock();
2818 return osr;
2819 }
2820 } else {
2821 if (best == NULL || (osr->comp_level() > best->comp_level())) {
2822 if (osr->comp_level() == CompLevel_highest_tier) {
2823 // Found the best possible - return it.
2824 OsrList_lock->unlock();
2825 return osr;
2826 }
2827 best = osr;
2828 }
2829 }
2830 }
2831 osr = osr->osr_link();
2832 }
2833 OsrList_lock->unlock();
2834 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2835 return best;
2836 }
2837 return NULL;
2838 }
2839
2840 void InstanceKlass::add_member_name(int index, Handle mem_name) {
2841 jweak mem_name_wref = JNIHandles::make_weak_global(mem_name);
2842 MutexLocker ml(MemberNameTable_lock);
2843 assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
2844 DEBUG_ONLY(No_Safepoint_Verifier nsv);
2845
2846 if (_member_names == NULL) {
2847 _member_names = new (ResourceObj::C_HEAP, mtClass) MemberNameTable(idnum_allocated_count());
2848 }
2849 _member_names->add_member_name(index, mem_name_wref);
2850 }
2851
2852 oop InstanceKlass::get_member_name(int index) {
2853 MutexLocker ml(MemberNameTable_lock);
2854 assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
2855 DEBUG_ONLY(No_Safepoint_Verifier nsv);
2856
2857 if (_member_names == NULL) {
2858 return NULL;
2859 }
2860 oop mem_name =_member_names->get_member_name(index);
2861 return mem_name;
2862 }
2863
2864 // -----------------------------------------------------------------------------------------------------
2865 // Printing
2866
2867 #ifndef PRODUCT
2868
2869 #define BULLET " - "
2870
2871 static const char* state_names[] = {
2872 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2873 };
2874
2875 static void print_vtable(intptr_t* start, int len, outputStream* st) {
2876 for (int i = 0; i < len; i++) {
2877 intptr_t e = start[i];
2878 st->print("%d : " INTPTR_FORMAT, i, e);
2879 if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2880 st->print(" ");
2881 ((Metadata*)e)->print_value_on(st);
2882 }
2883 st->cr();
2884 }
2885 }
2886
2887 void InstanceKlass::print_on(outputStream* st) const {
2888 assert(is_klass(), "must be klass");
2889 Klass::print_on(st);
2890
2891 st->print(BULLET"instance size: %d", size_helper()); st->cr();
2892 st->print(BULLET"klass size: %d", size()); st->cr();
2893 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
2894 st->print(BULLET"state: "); st->print_cr(state_names[_init_state]);
2895 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
2896 st->print(BULLET"super: "); super()->print_value_on_maybe_null(st); st->cr();
2897 st->print(BULLET"sub: ");
2898 Klass* sub = subklass();
2899 int n;
2900 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2901 if (n < MaxSubklassPrintSize) {
2902 sub->print_value_on(st);
2903 st->print(" ");
2904 }
2905 }
2906 if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
2907 st->cr();
2908
2909 if (is_interface()) {
2910 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
2911 if (nof_implementors() == 1) {
2912 st->print_cr(BULLET"implementor: ");
2913 st->print(" ");
2914 implementor()->print_value_on(st);
2915 st->cr();
2916 }
2917 }
2918
2919 st->print(BULLET"arrays: "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2920 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
2921 if (Verbose || WizardMode) {
2922 Array<Method*>* method_array = methods();
2923 for (int i = 0; i < method_array->length(); i++) {
2924 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2925 }
2926 }
2927 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
2928 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
2929 if (Verbose && default_methods() != NULL) {
2930 Array<Method*>* method_array = default_methods();
2931 for (int i = 0; i < method_array->length(); i++) {
2932 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2933 }
2934 }
2935 if (default_vtable_indices() != NULL) {
2936 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
2937 }
2938 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
2939 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2940 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
2941 if (class_loader_data() != NULL) {
2942 st->print(BULLET"class loader data: ");
2943 class_loader_data()->print_value_on(st);
2944 st->cr();
2945 }
2946 st->print(BULLET"host class: "); host_klass()->print_value_on_maybe_null(st); st->cr();
2947 if (source_file_name() != NULL) {
2948 st->print(BULLET"source file: ");
2949 source_file_name()->print_value_on(st);
2950 st->cr();
2951 }
2952 if (source_debug_extension() != NULL) {
2953 st->print(BULLET"source debug extension: ");
2954 st->print("%s", source_debug_extension());
2955 st->cr();
2956 }
2957 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
2958 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
2959 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
2960 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
2961 {
2962 bool have_pv = false;
2963 PreviousVersionWalker pvw(Thread::current(), (InstanceKlass*)this);
2964 for (PreviousVersionNode * pv_node = pvw.next_previous_version();
2965 pv_node != NULL; pv_node = pvw.next_previous_version()) {
2966 if (!have_pv)
2967 st->print(BULLET"previous version: ");
2968 have_pv = true;
2969 pv_node->prev_constant_pool()->print_value_on(st);
2970 }
2971 if (have_pv) st->cr();
2972 } // pvw is cleaned up
2973
2974 if (generic_signature() != NULL) {
2975 st->print(BULLET"generic signature: ");
2976 generic_signature()->print_value_on(st);
2977 st->cr();
2978 }
2979 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
2980 st->print(BULLET"java mirror: "); java_mirror()->print_value_on(st); st->cr();
2981 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable()); st->cr();
2982 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
2983 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
2984 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
2985 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2986 FieldPrinter print_static_field(st);
2987 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2988 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2989 FieldPrinter print_nonstatic_field(st);
2990 ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
2991
2992 st->print(BULLET"non-static oop maps: ");
2993 OopMapBlock* map = start_of_nonstatic_oop_maps();
2994 OopMapBlock* end_map = map + nonstatic_oop_map_count();
2995 while (map < end_map) {
2996 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2997 map++;
2998 }
2999 st->cr();
3000 }
3001
3002 #endif //PRODUCT
3003
3004 void InstanceKlass::print_value_on(outputStream* st) const {
3005 assert(is_klass(), "must be klass");
3006 if (Verbose || WizardMode) access_flags().print_on(st);
3007 name()->print_value_on(st);
3008 }
3009
3010 #ifndef PRODUCT
3011
3012 void FieldPrinter::do_field(fieldDescriptor* fd) {
3013 _st->print(BULLET);
3014 if (_obj == NULL) {
3015 fd->print_on(_st);
3016 _st->cr();
3017 } else {
3018 fd->print_on_for(_st, _obj);
3019 _st->cr();
3020 }
3021 }
3022
3023
3024 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3025 Klass::oop_print_on(obj, st);
3026
3027 if (this == SystemDictionary::String_klass()) {
3028 typeArrayOop value = java_lang_String::value(obj);
3029 juint offset = java_lang_String::offset(obj);
3030 juint length = java_lang_String::length(obj);
3031 if (value != NULL &&
3032 value->is_typeArray() &&
3033 offset <= (juint) value->length() &&
3034 offset + length <= (juint) value->length()) {
3035 st->print(BULLET"string: ");
3036 Handle h_obj(obj);
3037 java_lang_String::print(h_obj, st);
3038 st->cr();
3039 if (!WizardMode) return; // that is enough
3040 }
3041 }
3042
3043 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3044 FieldPrinter print_field(st, obj);
3045 do_nonstatic_fields(&print_field);
3046
3047 if (this == SystemDictionary::Class_klass()) {
3048 st->print(BULLET"signature: ");
3049 java_lang_Class::print_signature(obj, st);
3050 st->cr();
3051 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3052 st->print(BULLET"fake entry for mirror: ");
3053 mirrored_klass->print_value_on_maybe_null(st);
3054 st->cr();
3055 Klass* array_klass = java_lang_Class::array_klass(obj);
3056 st->print(BULLET"fake entry for array: ");
3057 array_klass->print_value_on_maybe_null(st);
3058 st->cr();
3059 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3060 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3061 Klass* real_klass = java_lang_Class::as_Klass(obj);
3062 if (real_klass != NULL && real_klass->oop_is_instance()) {
3063 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3064 }
3065 } else if (this == SystemDictionary::MethodType_klass()) {
3066 st->print(BULLET"signature: ");
3067 java_lang_invoke_MethodType::print_signature(obj, st);
3068 st->cr();
3069 }
3070 }
3071
3072 #endif //PRODUCT
3073
3074 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3075 st->print("a ");
3076 name()->print_value_on(st);
3077 obj->print_address_on(st);
3078 if (this == SystemDictionary::String_klass()
3079 && java_lang_String::value(obj) != NULL) {
3080 ResourceMark rm;
3081 int len = java_lang_String::length(obj);
3082 int plen = (len < 24 ? len : 12);
3083 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3084 st->print(" = \"%s\"", str);
3085 if (len > plen)
3086 st->print("...[%d]", len);
3087 } else if (this == SystemDictionary::Class_klass()) {
3088 Klass* k = java_lang_Class::as_Klass(obj);
3089 st->print(" = ");
3090 if (k != NULL) {
3091 k->print_value_on(st);
3092 } else {
3093 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3094 st->print("%s", tname ? tname : "type?");
3095 }
3096 } else if (this == SystemDictionary::MethodType_klass()) {
3097 st->print(" = ");
3098 java_lang_invoke_MethodType::print_signature(obj, st);
3099 } else if (java_lang_boxing_object::is_instance(obj)) {
3100 st->print(" = ");
3101 java_lang_boxing_object::print(obj, st);
3102 } else if (this == SystemDictionary::LambdaForm_klass()) {
3103 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3104 if (vmentry != NULL) {
3105 st->print(" => ");
3106 vmentry->print_value_on(st);
3107 }
3108 } else if (this == SystemDictionary::MemberName_klass()) {
3109 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3110 if (vmtarget != NULL) {
3111 st->print(" = ");
3112 vmtarget->print_value_on(st);
3113 } else {
3114 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3115 st->print(".");
3116 java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3117 }
3118 }
3119 }
3120
3121 const char* InstanceKlass::internal_name() const {
3122 return external_name();
3123 }
3124
3125 #if INCLUDE_SERVICES
3126 // Size Statistics
3127 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3128 Klass::collect_statistics(sz);
3129
3130 sz->_inst_size = HeapWordSize * size_helper();
3131 sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
3132 sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
3133 sz->_nonstatic_oopmap_bytes = HeapWordSize *
3134 ((is_interface() || is_anonymous()) ?
3135 align_object_offset(nonstatic_oop_map_size()) :
3136 nonstatic_oop_map_size());
3137
3138 int n = 0;
3139 n += (sz->_methods_array_bytes = sz->count_array(methods()));
3140 n += (sz->_method_ordering_bytes = sz->count_array(method_ordering()));
3141 n += (sz->_local_interfaces_bytes = sz->count_array(local_interfaces()));
3142 n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3143 n += (sz->_fields_bytes = sz->count_array(fields()));
3144 n += (sz->_inner_classes_bytes = sz->count_array(inner_classes()));
3145 sz->_ro_bytes += n;
3146
3147 const ConstantPool* cp = constants();
3148 if (cp) {
3149 cp->collect_statistics(sz);
3150 }
3151
3152 const Annotations* anno = annotations();
3153 if (anno) {
3154 anno->collect_statistics(sz);
3155 }
3156
3157 const Array<Method*>* methods_array = methods();
3158 if (methods()) {
3159 for (int i = 0; i < methods_array->length(); i++) {
3160 Method* method = methods_array->at(i);
3161 if (method) {
3162 sz->_method_count ++;
3163 method->collect_statistics(sz);
3164 }
3165 }
3166 }
3167 }
3168 #endif // INCLUDE_SERVICES
3169
3170 // Verification
3171
3172 class VerifyFieldClosure: public OopClosure {
3173 protected:
3174 template <class T> void do_oop_work(T* p) {
3175 oop obj = oopDesc::load_decode_heap_oop(p);
3176 if (!obj->is_oop_or_null()) {
3177 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
3178 Universe::print();
3179 guarantee(false, "boom");
3180 }
3181 }
3182 public:
3183 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3184 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3185 };
3186
3187 void InstanceKlass::verify_on(outputStream* st, bool check_dictionary) {
3188 #ifndef PRODUCT
3189 // Avoid redundant verifies, this really should be in product.
3190 if (_verify_count == Universe::verify_count()) return;
3191 _verify_count = Universe::verify_count();
3192 #endif
3193
3194 // Verify Klass
3195 Klass::verify_on(st, check_dictionary);
3196
3197 // Verify that klass is present in SystemDictionary if not already
3198 // verifying the SystemDictionary.
3199 if (is_loaded() && !is_anonymous() && check_dictionary) {
3200 Symbol* h_name = name();
3201 SystemDictionary::verify_obj_klass_present(h_name, class_loader_data());
3202 }
3203
3204 // Verify vtables
3205 if (is_linked()) {
3206 ResourceMark rm;
3207 // $$$ This used to be done only for m/s collections. Doing it
3208 // always seemed a valid generalization. (DLD -- 6/00)
3209 vtable()->verify(st);
3210 }
3211
3212 // Verify first subklass
3213 if (subklass_oop() != NULL) {
3214 guarantee(subklass_oop()->is_klass(), "should be klass");
3215 }
3216
3217 // Verify siblings
3218 Klass* super = this->super();
3219 Klass* sib = next_sibling();
3220 if (sib != NULL) {
3221 if (sib == this) {
3222 fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
3223 }
3224
3225 guarantee(sib->is_klass(), "should be klass");
3226 guarantee(sib->super() == super, "siblings should have same superklass");
3227 }
3228
3229 // Verify implementor fields
3230 Klass* im = implementor();
3231 if (im != NULL) {
3232 guarantee(is_interface(), "only interfaces should have implementor set");
3233 guarantee(im->is_klass(), "should be klass");
3234 guarantee(!im->is_interface() || im == this,
3235 "implementors cannot be interfaces");
3236 }
3237
3238 // Verify local interfaces
3239 if (local_interfaces()) {
3240 Array<Klass*>* local_interfaces = this->local_interfaces();
3241 for (int j = 0; j < local_interfaces->length(); j++) {
3242 Klass* e = local_interfaces->at(j);
3243 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3244 }
3245 }
3246
3247 // Verify transitive interfaces
3248 if (transitive_interfaces() != NULL) {
3249 Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3250 for (int j = 0; j < transitive_interfaces->length(); j++) {
3251 Klass* e = transitive_interfaces->at(j);
3252 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3253 }
3254 }
3255
3256 // Verify methods
3257 if (methods() != NULL) {
3258 Array<Method*>* methods = this->methods();
3259 for (int j = 0; j < methods->length(); j++) {
3260 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3261 }
3262 for (int j = 0; j < methods->length() - 1; j++) {
3263 Method* m1 = methods->at(j);
3264 Method* m2 = methods->at(j + 1);
3265 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3266 }
3267 }
3268
3269 // Verify method ordering
3270 if (method_ordering() != NULL) {
3271 Array<int>* method_ordering = this->method_ordering();
3272 int length = method_ordering->length();
3273 if (JvmtiExport::can_maintain_original_method_order() ||
3274 ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3275 guarantee(length == methods()->length(), "invalid method ordering length");
3276 jlong sum = 0;
3277 for (int j = 0; j < length; j++) {
3278 int original_index = method_ordering->at(j);
3279 guarantee(original_index >= 0, "invalid method ordering index");
3280 guarantee(original_index < length, "invalid method ordering index");
3281 sum += original_index;
3282 }
3283 // Verify sum of indices 0,1,...,length-1
3284 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3285 } else {
3286 guarantee(length == 0, "invalid method ordering length");
3287 }
3288 }
3289
3290 // Verify default methods
3291 if (default_methods() != NULL) {
3292 Array<Method*>* methods = this->default_methods();
3293 for (int j = 0; j < methods->length(); j++) {
3294 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3295 }
3296 for (int j = 0; j < methods->length() - 1; j++) {
3297 Method* m1 = methods->at(j);
3298 Method* m2 = methods->at(j + 1);
3299 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3300 }
3301 }
3302
3303 // Verify JNI static field identifiers
3304 if (jni_ids() != NULL) {
3305 jni_ids()->verify(this);
3306 }
3307
3308 // Verify other fields
3309 if (array_klasses() != NULL) {
3310 guarantee(array_klasses()->is_klass(), "should be klass");
3311 }
3312 if (constants() != NULL) {
3313 guarantee(constants()->is_constantPool(), "should be constant pool");
3314 }
3315 const Klass* host = host_klass();
3316 if (host != NULL) {
3317 guarantee(host->is_klass(), "should be klass");
3318 }
3319 }
3320
3321 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3322 Klass::oop_verify_on(obj, st);
3323 VerifyFieldClosure blk;
3324 obj->oop_iterate_no_header(&blk);
3325 }
3326
3327
3328 // JNIid class for jfieldIDs only
3329 // Note to reviewers:
3330 // These JNI functions are just moved over to column 1 and not changed
3331 // in the compressed oops workspace.
3332 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3333 _holder = holder;
3334 _offset = offset;
3335 _next = next;
3336 debug_only(_is_static_field_id = false;)
3337 }
3338
3339
3340 JNIid* JNIid::find(int offset) {
3341 JNIid* current = this;
3342 while (current != NULL) {
3343 if (current->offset() == offset) return current;
3344 current = current->next();
3345 }
3346 return NULL;
3347 }
3348
3349 void JNIid::deallocate(JNIid* current) {
3350 while (current != NULL) {
3351 JNIid* next = current->next();
3352 delete current;
3353 current = next;
3354 }
3355 }
3356
3357
3358 void JNIid::verify(Klass* holder) {
3359 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3360 int end_field_offset;
3361 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3362
3363 JNIid* current = this;
3364 while (current != NULL) {
3365 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3366 #ifdef ASSERT
3367 int o = current->offset();
3368 if (current->is_static_field_id()) {
3369 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3370 }
3371 #endif
3372 current = current->next();
3373 }
3374 }
3375
3376
3377 #ifdef ASSERT
3378 void InstanceKlass::set_init_state(ClassState state) {
3379 bool good_state = is_shared() ? (_init_state <= state)
3380 : (_init_state < state);
3381 assert(good_state || state == allocated, "illegal state transition");
3382 _init_state = (u1)state;
3383 }
3384 #endif
3385
3386
3387 // RedefineClasses() support for previous versions:
3388
3389 // Purge previous versions
3390 static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
3391 if (ik->previous_versions() != NULL) {
3392 // This klass has previous versions so see what we can cleanup
3393 // while it is safe to do so.
3394
3395 int deleted_count = 0; // leave debugging breadcrumbs
3396 int live_count = 0;
3397 ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
3398 ClassLoaderData::the_null_class_loader_data() :
3399 ik->class_loader_data();
3400
3401 // RC_TRACE macro has an embedded ResourceMark
3402 RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
3403 ik->external_name(), ik->previous_versions()->length()));
3404
3405 for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
3406 // check the previous versions array
3407 PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
3408 ConstantPool* cp_ref = pv_node->prev_constant_pool();
3409 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
3410
3411 ConstantPool* pvcp = cp_ref;
3412 if (!pvcp->on_stack()) {
3413 // If the constant pool isn't on stack, none of the methods
3414 // are executing. Delete all the methods, the constant pool and
3415 // and this previous version node.
3416 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3417 if (method_refs != NULL) {
3418 for (int j = method_refs->length() - 1; j >= 0; j--) {
3419 Method* method = method_refs->at(j);
3420 assert(method != NULL, "method ref was unexpectedly cleared");
3421 method_refs->remove_at(j);
3422 // method will be freed with associated class.
3423 }
3424 }
3425 // Remove the constant pool
3426 delete pv_node;
3427 // Since we are traversing the array backwards, we don't have to
3428 // do anything special with the index.
3429 ik->previous_versions()->remove_at(i);
3430 deleted_count++;
3431 continue;
3432 } else {
3433 RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
3434 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3435 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3436 live_count++;
3437 }
3438
3439 // At least one method is live in this previous version, clean out
3440 // the others or mark them as obsolete.
3441 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3442 if (method_refs != NULL) {
3443 RC_TRACE(0x00000200, ("purge: previous methods length=%d",
3444 method_refs->length()));
3445 for (int j = method_refs->length() - 1; j >= 0; j--) {
3446 Method* method = method_refs->at(j);
3447 assert(method != NULL, "method ref was unexpectedly cleared");
3448
3449 // Remove the emcp method if it's not executing
3450 // If it's been made obsolete by a redefinition of a non-emcp
3451 // method, mark it as obsolete but leave it to clean up later.
3452 if (!method->on_stack()) {
3453 method_refs->remove_at(j);
3454 } else if (emcp_method_count == 0) {
3455 method->set_is_obsolete();
3456 } else {
3457 // RC_TRACE macro has an embedded ResourceMark
3458 RC_TRACE(0x00000200,
3459 ("purge: %s(%s): prev method @%d in version @%d is alive",
3460 method->name()->as_C_string(),
3461 method->signature()->as_C_string(), j, i));
3462 }
3463 }
3464 }
3465 }
3466 assert(ik->previous_versions()->length() == live_count, "sanity check");
3467 RC_TRACE(0x00000200,
3468 ("purge: previous version stats: live=%d, deleted=%d", live_count,
3469 deleted_count));
3470 }
3471 }
3472
3473 // External interface for use during class unloading.
3474 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
3475 // Call with >0 emcp methods since they are not currently being redefined.
3476 purge_previous_versions_internal(ik, 1);
3477 }
3478
3479
3480 // Potentially add an information node that contains pointers to the
3481 // interesting parts of the previous version of the_class.
3482 // This is also where we clean out any unused references.
3483 // Note that while we delete nodes from the _previous_versions
3484 // array, we never delete the array itself until the klass is
3485 // unloaded. The has_been_redefined() query depends on that fact.
3486 //
3487 void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
3488 BitMap* emcp_methods, int emcp_method_count) {
3489 assert(Thread::current()->is_VM_thread(),
3490 "only VMThread can add previous versions");
3491
3492 if (_previous_versions == NULL) {
3493 // This is the first previous version so make some space.
3494 // Start with 2 elements under the assumption that the class
3495 // won't be redefined much.
3496 _previous_versions = new (ResourceObj::C_HEAP, mtClass)
3497 GrowableArray<PreviousVersionNode *>(2, true);
3498 }
3499
3500 ConstantPool* cp_ref = ikh->constants();
3501
3502 // RC_TRACE macro has an embedded ResourceMark
3503 RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
3504 "on_stack=%d",
3505 ikh->external_name(), _previous_versions->length(), emcp_method_count,
3506 cp_ref->on_stack()));
3507
3508 // If the constant pool for this previous version of the class
3509 // is not marked as being on the stack, then none of the methods
3510 // in this previous version of the class are on the stack so
3511 // we don't need to create a new PreviousVersionNode. However,
3512 // we still need to examine older previous versions below.
3513 Array<Method*>* old_methods = ikh->methods();
3514
3515 if (cp_ref->on_stack()) {
3516 PreviousVersionNode * pv_node = NULL;
3517 if (emcp_method_count == 0) {
3518 // non-shared ConstantPool gets a reference
3519 pv_node = new PreviousVersionNode(cp_ref, NULL);
3520 RC_TRACE(0x00000400,
3521 ("add: all methods are obsolete; flushing any EMCP refs"));
3522 } else {
3523 int local_count = 0;
3524 GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
3525 GrowableArray<Method*>(emcp_method_count, true);
3526 for (int i = 0; i < old_methods->length(); i++) {
3527 if (emcp_methods->at(i)) {
3528 // this old method is EMCP. Save it only if it's on the stack
3529 Method* old_method = old_methods->at(i);
3530 if (old_method->on_stack()) {
3531 method_refs->append(old_method);
3532 }
3533 if (++local_count >= emcp_method_count) {
3534 // no more EMCP methods so bail out now
3535 break;
3536 }
3537 }
3538 }
3539 // non-shared ConstantPool gets a reference
3540 pv_node = new PreviousVersionNode(cp_ref, method_refs);
3541 }
3542 // append new previous version.
3543 _previous_versions->append(pv_node);
3544 }
3545
3546 // Since the caller is the VMThread and we are at a safepoint, this
3547 // is a good time to clear out unused references.
3548
3549 RC_TRACE(0x00000400, ("add: previous version length=%d",
3550 _previous_versions->length()));
3551
3552 // Purge previous versions not executing on the stack
3553 purge_previous_versions_internal(this, emcp_method_count);
3554
3555 int obsolete_method_count = old_methods->length() - emcp_method_count;
3556
3557 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3558 _previous_versions->length() > 0) {
3559 // We have a mix of obsolete and EMCP methods so we have to
3560 // clear out any matching EMCP method entries the hard way.
3561 int local_count = 0;
3562 for (int i = 0; i < old_methods->length(); i++) {
3563 if (!emcp_methods->at(i)) {
3564 // only obsolete methods are interesting
3565 Method* old_method = old_methods->at(i);
3566 Symbol* m_name = old_method->name();
3567 Symbol* m_signature = old_method->signature();
3568
3569 // we might not have added the last entry
3570 for (int j = _previous_versions->length() - 1; j >= 0; j--) {
3571 // check the previous versions array for non executing obsolete methods
3572 PreviousVersionNode * pv_node = _previous_versions->at(j);
3573
3574 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3575 if (method_refs == NULL) {
3576 // We have run into a PreviousVersion generation where
3577 // all methods were made obsolete during that generation's
3578 // RedefineClasses() operation. At the time of that
3579 // operation, all EMCP methods were flushed so we don't
3580 // have to go back any further.
3581 //
3582 // A NULL method_refs is different than an empty method_refs.
3583 // We cannot infer any optimizations about older generations
3584 // from an empty method_refs for the current generation.
3585 break;
3586 }
3587
3588 for (int k = method_refs->length() - 1; k >= 0; k--) {
3589 Method* method = method_refs->at(k);
3590
3591 if (!method->is_obsolete() &&
3592 method->name() == m_name &&
3593 method->signature() == m_signature) {
3594 // The current RedefineClasses() call has made all EMCP
3595 // versions of this method obsolete so mark it as obsolete
3596 // and remove the reference.
3597 RC_TRACE(0x00000400,
3598 ("add: %s(%s): flush obsolete method @%d in version @%d",
3599 m_name->as_C_string(), m_signature->as_C_string(), k, j));
3600
3601 method->set_is_obsolete();
3602 // Leave obsolete methods on the previous version list to
3603 // clean up later.
3604 break;
3605 }
3606 }
3607
3608 // The previous loop may not find a matching EMCP method, but
3609 // that doesn't mean that we can optimize and not go any
3610 // further back in the PreviousVersion generations. The EMCP
3611 // method for this generation could have already been deleted,
3612 // but there still may be an older EMCP method that has not
3613 // been deleted.
3614 }
3615
3616 if (++local_count >= obsolete_method_count) {
3617 // no more obsolete methods so bail out now
3618 break;
3619 }
3620 }
3621 }
3622 }
3623 } // end add_previous_version()
3624
3625
3626 // Determine if InstanceKlass has a previous version.
3627 bool InstanceKlass::has_previous_version() const {
3628 return (_previous_versions != NULL && _previous_versions->length() > 0);
3629 } // end has_previous_version()
3630
3631
3632 Method* InstanceKlass::method_with_idnum(int idnum) {
3633 Method* m = NULL;
3634 if (idnum < methods()->length()) {
3635 m = methods()->at(idnum);
3636 }
3637 if (m == NULL || m->method_idnum() != idnum) {
3638 for (int index = 0; index < methods()->length(); ++index) {
3639 m = methods()->at(index);
3640 if (m->method_idnum() == idnum) {
3641 return m;
3642 }
3643 }
3644 // None found, return null for the caller to handle.
3645 return NULL;
3646 }
3647 return m;
3648 }
3649
3650 jint InstanceKlass::get_cached_class_file_len() {
3651 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3652 }
3653
3654 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3655 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3656 }
3657
3658
3659 // Construct a PreviousVersionNode entry for the array hung off
3660 // the InstanceKlass.
3661 PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
3662 GrowableArray<Method*>* prev_EMCP_methods) {
3663
3664 _prev_constant_pool = prev_constant_pool;
3665 _prev_EMCP_methods = prev_EMCP_methods;
3666 }
3667
3668
3669 // Destroy a PreviousVersionNode
3670 PreviousVersionNode::~PreviousVersionNode() {
3671 if (_prev_constant_pool != NULL) {
3672 _prev_constant_pool = NULL;
3673 }
3674
3675 if (_prev_EMCP_methods != NULL) {
3676 delete _prev_EMCP_methods;
3677 }
3678 }
3679
3680 // Construct a helper for walking the previous versions array
3681 PreviousVersionWalker::PreviousVersionWalker(Thread* thread, InstanceKlass *ik) {
3682 _thread = thread;
3683 _previous_versions = ik->previous_versions();
3684 _current_index = 0;
3685 _current_p = NULL;
3686 _current_constant_pool_handle = constantPoolHandle(thread, ik->constants());
3687 }
3688
3689
3690 // Return the interesting information for the next previous version
3691 // of the klass. Returns NULL if there are no more previous versions.
3692 PreviousVersionNode* PreviousVersionWalker::next_previous_version() {
3693 if (_previous_versions == NULL) {
3694 // no previous versions so nothing to return
3695 return NULL;
3696 }
3697
3698 _current_p = NULL; // reset to NULL
3699 _current_constant_pool_handle = NULL;
3700
3701 int length = _previous_versions->length();
3702
3703 while (_current_index < length) {
3704 PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
3705
3706 // Save a handle to the constant pool for this previous version,
3707 // which keeps all the methods from being deallocated.
3708 _current_constant_pool_handle = constantPoolHandle(_thread, pv_node->prev_constant_pool());
3709 _current_p = pv_node;
3710 return pv_node;
3711 }
3712
3713 return NULL;
3714 } // end next_previous_version()