Tue, 26 Nov 2013 14:35:38 +0100
8027675: Full collections with Serial slower in JDK 8 compared to 7u40
Summary: Reduced the number of calls to follow_class_loader and instead marked and pushed the klass holder directly. Also removed unneeded calls to adjust_klass.
Reviewed-by: coleenp, jmasa, mgerdin, tschatzl
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 */
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
78 #ifdef DTRACE_ENABLED
80 #ifndef USDT2
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);
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 }
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 */
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 }
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 */
161 #else // ndef DTRACE_ENABLED
163 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
164 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
166 #endif // ndef DTRACE_ENABLED
168 volatile int InstanceKlass::_total_instanceKlass_count = 0;
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) {
183 int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
184 access_flags.is_interface(), is_anonymous);
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 }
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 }
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);
223 Atomic::inc(&_total_instanceKlass_count);
224 return ik;
225 }
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 }
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 }
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
258 int iksize = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
259 access_flags.is_interface(), is_anonymous);
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");
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;)
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 }
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 }
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 }
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 }
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 }
360 // This function deallocates the metadata and C heap pointers that the
361 // InstanceKlass points to.
362 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
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 }
369 // Need to take this class off the class loader data list.
370 loader_data->remove_class(this);
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");
378 // Release C heap allocated data that this might point to, which includes
379 // reference counting symbol names.
380 release_C_heap_structures();
382 deallocate_methods(loader_data, methods());
383 set_methods(NULL);
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);
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);
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);
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);
420 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
421 set_transitive_interfaces(NULL);
422 set_local_interfaces(NULL);
424 if (fields() != NULL && !fields()->is_shared()) {
425 MetadataFactory::free_array<jushort>(loader_data, fields());
426 }
427 set_fields(NULL, 0);
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 }
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);
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 }
453 bool InstanceKlass::should_be_initialized() const {
454 return !is_initialized();
455 }
457 klassVtable* InstanceKlass::vtable() const {
458 return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
459 }
461 klassItable* InstanceKlass::itable() const {
462 return new klassItable(instanceKlassHandle(this));
463 }
465 void InstanceKlass::eager_initialize(Thread *thread) {
466 if (!EagerInitialization) return;
468 if (this->is_not_initialized()) {
469 // abort if the the class has a class initializer
470 if (this->class_initializer() != NULL) return;
472 // abort if it is java.lang.Object (initialization is handled in genesis)
473 Klass* super = this->super();
474 if (super == NULL) return;
476 // abort if the super class should be initialized
477 if (!InstanceKlass::cast(super)->is_initialized()) return;
479 // call body to expose the this pointer
480 instanceKlassHandle this_oop(thread, this);
481 eager_initialize_impl(this_oop);
482 }
483 }
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 }
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 }
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 }
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 }
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);
523 // abort if someone beat us to the initialization
524 if (!this_oop->is_not_initialized()) return; // note: not equivalent to is_initialized()
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.
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 }
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 }
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 }
576 // Used exclusively by the shared spaces dump mechanism to prevent
577 // classes mapped into the shared regions in new VMs from appearing linked.
579 void InstanceKlass::unlink_class() {
580 assert(is_linked(), "must be linked");
581 _init_state = loaded;
582 }
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 }
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 }
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 }
618 // Timing
619 // timer handles recursion
620 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
621 JavaThread* jt = (JavaThread*)THREAD;
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 }
638 link_class_impl(super, throw_verifyerror, CHECK_false);
639 }
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 }
650 // in case the class is linked in the process of linking its superclasses
651 if (this_oop->is_linked()) {
652 return true;
653 }
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);
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
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 }
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 }
696 // also sets rewritten
697 this_oop->rewrite_class(CHECK_false);
698 }
700 // relocate jsrs and link methods after they are all rewritten
701 this_oop->link_methods(CHECK_false);
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 }
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 }
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));
754 // Set up method entry points for compiler and interpreter .
755 m->link_method(m, CHECK);
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 }
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);
782 DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
784 bool wait = false;
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);
792 Thread *self = THREAD; // it's passed the current thread
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 }
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 }
809 // Step 4
810 if (this_oop->is_initialized()) {
811 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
812 return;
813 }
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 }
832 // Step 6
833 this_oop->set_init_state(being_initialized);
834 this_oop->set_init_thread(self);
835 }
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);
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 }
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);
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);
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 }
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 }
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 }
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 }
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 }
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;
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;
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 }
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 }
985 void InstanceKlass::init_implementor() {
986 if (is_interface()) {
987 set_implementor(NULL);
988 }
989 }
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 }
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 }
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 }
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 }
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 }
1054 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1055 if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
1056 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
1057 report_java_out_of_memory("Requested array size exceeds VM limit");
1058 JvmtiExport::post_array_size_exhausted();
1059 THROW_OOP_0(Universe::out_of_memory_error_array_size());
1060 }
1061 int size = objArrayOopDesc::object_size(length);
1062 Klass* ak = array_klass(n, CHECK_NULL);
1063 KlassHandle h_ak (THREAD, ak);
1064 objArrayOop o =
1065 (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
1066 return o;
1067 }
1069 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1070 if (TraceFinalizerRegistration) {
1071 tty->print("Registered ");
1072 i->print_value_on(tty);
1073 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
1074 }
1075 instanceHandle h_i(THREAD, i);
1076 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1077 JavaValue result(T_VOID);
1078 JavaCallArguments args(h_i);
1079 methodHandle mh (THREAD, Universe::finalizer_register_method());
1080 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1081 return h_i();
1082 }
1084 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1085 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1086 int size = size_helper(); // Query before forming handle.
1088 KlassHandle h_k(THREAD, this);
1090 instanceOop i;
1092 i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
1093 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1094 i = register_finalizer(i, CHECK_NULL);
1095 }
1096 return i;
1097 }
1099 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1100 if (is_interface() || is_abstract()) {
1101 ResourceMark rm(THREAD);
1102 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1103 : vmSymbols::java_lang_InstantiationException(), external_name());
1104 }
1105 if (this == SystemDictionary::Class_klass()) {
1106 ResourceMark rm(THREAD);
1107 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1108 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1109 }
1110 }
1112 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1113 instanceKlassHandle this_oop(THREAD, this);
1114 return array_klass_impl(this_oop, or_null, n, THREAD);
1115 }
1117 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
1118 if (this_oop->array_klasses() == NULL) {
1119 if (or_null) return NULL;
1121 ResourceMark rm;
1122 JavaThread *jt = (JavaThread *)THREAD;
1123 {
1124 // Atomic creation of array_klasses
1125 MutexLocker mc(Compile_lock, THREAD); // for vtables
1126 MutexLocker ma(MultiArray_lock, THREAD);
1128 // Check if update has already taken place
1129 if (this_oop->array_klasses() == NULL) {
1130 Klass* k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
1131 this_oop->set_array_klasses(k);
1132 }
1133 }
1134 }
1135 // _this will always be set at this point
1136 ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
1137 if (or_null) {
1138 return oak->array_klass_or_null(n);
1139 }
1140 return oak->array_klass(n, CHECK_NULL);
1141 }
1143 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1144 return array_klass_impl(or_null, 1, THREAD);
1145 }
1147 void InstanceKlass::call_class_initializer(TRAPS) {
1148 instanceKlassHandle ik (THREAD, this);
1149 call_class_initializer_impl(ik, THREAD);
1150 }
1152 static int call_class_initializer_impl_counter = 0; // for debugging
1154 Method* InstanceKlass::class_initializer() {
1155 Method* clinit = find_method(
1156 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1157 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1158 return clinit;
1159 }
1160 return NULL;
1161 }
1163 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
1164 if (ReplayCompiles &&
1165 (ReplaySuppressInitializers == 1 ||
1166 ReplaySuppressInitializers >= 2 && this_oop->class_loader() != NULL)) {
1167 // Hide the existence of the initializer for the purpose of replaying the compile
1168 return;
1169 }
1171 methodHandle h_method(THREAD, this_oop->class_initializer());
1172 assert(!this_oop->is_initialized(), "we cannot initialize twice");
1173 if (TraceClassInitialization) {
1174 tty->print("%d Initializing ", call_class_initializer_impl_counter++);
1175 this_oop->name()->print_value();
1176 tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
1177 }
1178 if (h_method() != NULL) {
1179 JavaCallArguments args; // No arguments
1180 JavaValue result(T_VOID);
1181 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1182 }
1183 }
1186 void InstanceKlass::mask_for(methodHandle method, int bci,
1187 InterpreterOopMap* entry_for) {
1188 // Dirty read, then double-check under a lock.
1189 if (_oop_map_cache == NULL) {
1190 // Otherwise, allocate a new one.
1191 MutexLocker x(OopMapCacheAlloc_lock);
1192 // First time use. Allocate a cache in C heap
1193 if (_oop_map_cache == NULL) {
1194 _oop_map_cache = new OopMapCache();
1195 }
1196 }
1197 // _oop_map_cache is constant after init; lookup below does is own locking.
1198 _oop_map_cache->lookup(method, bci, entry_for);
1199 }
1202 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1203 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1204 Symbol* f_name = fs.name();
1205 Symbol* f_sig = fs.signature();
1206 if (f_name == name && f_sig == sig) {
1207 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1208 return true;
1209 }
1210 }
1211 return false;
1212 }
1215 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1216 const int n = local_interfaces()->length();
1217 for (int i = 0; i < n; i++) {
1218 Klass* intf1 = local_interfaces()->at(i);
1219 assert(intf1->is_interface(), "just checking type");
1220 // search for field in current interface
1221 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1222 assert(fd->is_static(), "interface field must be static");
1223 return intf1;
1224 }
1225 // search for field in direct superinterfaces
1226 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1227 if (intf2 != NULL) return intf2;
1228 }
1229 // otherwise field lookup fails
1230 return NULL;
1231 }
1234 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1235 // search order according to newest JVM spec (5.4.3.2, p.167).
1236 // 1) search for field in current klass
1237 if (find_local_field(name, sig, fd)) {
1238 return const_cast<InstanceKlass*>(this);
1239 }
1240 // 2) search for field recursively in direct superinterfaces
1241 { Klass* intf = find_interface_field(name, sig, fd);
1242 if (intf != NULL) return intf;
1243 }
1244 // 3) apply field lookup recursively if superclass exists
1245 { Klass* supr = super();
1246 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1247 }
1248 // 4) otherwise field lookup fails
1249 return NULL;
1250 }
1253 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1254 // search order according to newest JVM spec (5.4.3.2, p.167).
1255 // 1) search for field in current klass
1256 if (find_local_field(name, sig, fd)) {
1257 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1258 }
1259 // 2) search for field recursively in direct superinterfaces
1260 if (is_static) {
1261 Klass* intf = find_interface_field(name, sig, fd);
1262 if (intf != NULL) return intf;
1263 }
1264 // 3) apply field lookup recursively if superclass exists
1265 { Klass* supr = super();
1266 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1267 }
1268 // 4) otherwise field lookup fails
1269 return NULL;
1270 }
1273 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1274 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1275 if (fs.offset() == offset) {
1276 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1277 if (fd->is_static() == is_static) return true;
1278 }
1279 }
1280 return false;
1281 }
1284 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1285 Klass* klass = const_cast<InstanceKlass*>(this);
1286 while (klass != NULL) {
1287 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1288 return true;
1289 }
1290 klass = klass->super();
1291 }
1292 return false;
1293 }
1296 void InstanceKlass::methods_do(void f(Method* method)) {
1297 int len = methods()->length();
1298 for (int index = 0; index < len; index++) {
1299 Method* m = methods()->at(index);
1300 assert(m->is_method(), "must be method");
1301 f(m);
1302 }
1303 }
1306 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1307 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1308 if (fs.access_flags().is_static()) {
1309 fieldDescriptor& fd = fs.field_descriptor();
1310 cl->do_field(&fd);
1311 }
1312 }
1313 }
1316 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
1317 instanceKlassHandle h_this(THREAD, this);
1318 do_local_static_fields_impl(h_this, f, CHECK);
1319 }
1322 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
1323 for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
1324 if (fs.access_flags().is_static()) {
1325 fieldDescriptor& fd = fs.field_descriptor();
1326 f(&fd, CHECK);
1327 }
1328 }
1329 }
1332 static int compare_fields_by_offset(int* a, int* b) {
1333 return a[0] - b[0];
1334 }
1336 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1337 InstanceKlass* super = superklass();
1338 if (super != NULL) {
1339 super->do_nonstatic_fields(cl);
1340 }
1341 fieldDescriptor fd;
1342 int length = java_fields_count();
1343 // In DebugInfo nonstatic fields are sorted by offset.
1344 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1345 int j = 0;
1346 for (int i = 0; i < length; i += 1) {
1347 fd.reinitialize(this, i);
1348 if (!fd.is_static()) {
1349 fields_sorted[j + 0] = fd.offset();
1350 fields_sorted[j + 1] = i;
1351 j += 2;
1352 }
1353 }
1354 if (j > 0) {
1355 length = j;
1356 // _sort_Fn is defined in growableArray.hpp.
1357 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1358 for (int i = 0; i < length; i += 2) {
1359 fd.reinitialize(this, fields_sorted[i + 1]);
1360 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1361 cl->do_field(&fd);
1362 }
1363 }
1364 FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
1365 }
1368 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1369 if (array_klasses() != NULL)
1370 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1371 }
1373 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1374 if (array_klasses() != NULL)
1375 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1376 }
1378 #ifdef ASSERT
1379 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
1380 int len = methods->length();
1381 for (int index = 0; index < len; index++) {
1382 Method* m = methods->at(index);
1383 assert(m->is_method(), "must be method");
1384 if (m->signature() == signature && m->name() == name) {
1385 return index;
1386 }
1387 }
1388 return -1;
1389 }
1390 #endif
1392 static int binary_search(Array<Method*>* methods, Symbol* name) {
1393 int len = methods->length();
1394 // methods are sorted, so do binary search
1395 int l = 0;
1396 int h = len - 1;
1397 while (l <= h) {
1398 int mid = (l + h) >> 1;
1399 Method* m = methods->at(mid);
1400 assert(m->is_method(), "must be method");
1401 int res = m->name()->fast_compare(name);
1402 if (res == 0) {
1403 return mid;
1404 } else if (res < 0) {
1405 l = mid + 1;
1406 } else {
1407 h = mid - 1;
1408 }
1409 }
1410 return -1;
1411 }
1413 // find_method looks up the name/signature in the local methods array
1414 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
1415 return InstanceKlass::find_method(methods(), name, signature);
1416 }
1418 // find_method looks up the name/signature in the local methods array
1419 Method* InstanceKlass::find_method(
1420 Array<Method*>* methods, Symbol* name, Symbol* signature) {
1421 int hit = find_method_index(methods, name, signature);
1422 return hit >= 0 ? methods->at(hit): NULL;
1423 }
1425 // Used directly for default_methods to find the index into the
1426 // default_vtable_indices, and indirectly by find_method
1427 // find_method_index looks in the local methods array to return the index
1428 // of the matching name/signature
1429 int InstanceKlass::find_method_index(
1430 Array<Method*>* methods, Symbol* name, Symbol* signature) {
1431 int hit = binary_search(methods, name);
1432 if (hit != -1) {
1433 Method* m = methods->at(hit);
1434 // Do linear search to find matching signature. First, quick check
1435 // for common case
1436 if (m->signature() == signature) return hit;
1437 // search downwards through overloaded methods
1438 int i;
1439 for (i = hit - 1; i >= 0; --i) {
1440 Method* m = methods->at(i);
1441 assert(m->is_method(), "must be method");
1442 if (m->name() != name) break;
1443 if (m->signature() == signature) return i;
1444 }
1445 // search upwards
1446 for (i = hit + 1; i < methods->length(); ++i) {
1447 Method* m = methods->at(i);
1448 assert(m->is_method(), "must be method");
1449 if (m->name() != name) break;
1450 if (m->signature() == signature) return i;
1451 }
1452 // not found
1453 #ifdef ASSERT
1454 int index = linear_search(methods, name, signature);
1455 assert(index == -1, err_msg("binary search should have found entry %d", index));
1456 #endif
1457 }
1458 return -1;
1459 }
1460 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
1461 return find_method_by_name(methods(), name, end);
1462 }
1464 int InstanceKlass::find_method_by_name(
1465 Array<Method*>* methods, Symbol* name, int* end_ptr) {
1466 assert(end_ptr != NULL, "just checking");
1467 int start = binary_search(methods, name);
1468 int end = start + 1;
1469 if (start != -1) {
1470 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1471 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1472 *end_ptr = end;
1473 return start;
1474 }
1475 return -1;
1476 }
1478 // lookup_method searches both the local methods array and all superclasses methods arrays
1479 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
1480 Klass* klass = const_cast<InstanceKlass*>(this);
1481 while (klass != NULL) {
1482 Method* method = InstanceKlass::cast(klass)->find_method(name, signature);
1483 if (method != NULL) return method;
1484 klass = InstanceKlass::cast(klass)->super();
1485 }
1486 return NULL;
1487 }
1489 // lookup a method in the default methods list then in all transitive interfaces
1490 // Do NOT return private or static methods
1491 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1492 Symbol* signature) const {
1493 Method* m = NULL;
1494 if (default_methods() != NULL) {
1495 m = find_method(default_methods(), name, signature);
1496 }
1497 // Look up interfaces
1498 if (m == NULL) {
1499 m = lookup_method_in_all_interfaces(name, signature);
1500 }
1501 return m;
1502 }
1504 // lookup a method in all the interfaces that this class implements
1505 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1506 // They should only be found in the initial InterfaceMethodRef
1507 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1508 Symbol* signature) const {
1509 Array<Klass*>* all_ifs = transitive_interfaces();
1510 int num_ifs = all_ifs->length();
1511 InstanceKlass *ik = NULL;
1512 for (int i = 0; i < num_ifs; i++) {
1513 ik = InstanceKlass::cast(all_ifs->at(i));
1514 Method* m = ik->lookup_method(name, signature);
1515 if (m != NULL && m->is_public() && !m->is_static()) {
1516 return m;
1517 }
1518 }
1519 return NULL;
1520 }
1522 /* jni_id_for_impl for jfieldIds only */
1523 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
1524 MutexLocker ml(JfieldIdCreation_lock);
1525 // Retry lookup after we got the lock
1526 JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
1527 if (probe == NULL) {
1528 // Slow case, allocate new static field identifier
1529 probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
1530 this_oop->set_jni_ids(probe);
1531 }
1532 return probe;
1533 }
1536 /* jni_id_for for jfieldIds only */
1537 JNIid* InstanceKlass::jni_id_for(int offset) {
1538 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1539 if (probe == NULL) {
1540 probe = jni_id_for_impl(this, offset);
1541 }
1542 return probe;
1543 }
1545 u2 InstanceKlass::enclosing_method_data(int offset) {
1546 Array<jushort>* inner_class_list = inner_classes();
1547 if (inner_class_list == NULL) {
1548 return 0;
1549 }
1550 int length = inner_class_list->length();
1551 if (length % inner_class_next_offset == 0) {
1552 return 0;
1553 } else {
1554 int index = length - enclosing_method_attribute_size;
1555 assert(offset < enclosing_method_attribute_size, "invalid offset");
1556 return inner_class_list->at(index + offset);
1557 }
1558 }
1560 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1561 u2 method_index) {
1562 Array<jushort>* inner_class_list = inner_classes();
1563 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1564 int length = inner_class_list->length();
1565 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1566 int index = length - enclosing_method_attribute_size;
1567 inner_class_list->at_put(
1568 index + enclosing_method_class_index_offset, class_index);
1569 inner_class_list->at_put(
1570 index + enclosing_method_method_index_offset, method_index);
1571 }
1572 }
1574 // Lookup or create a jmethodID.
1575 // This code is called by the VMThread and JavaThreads so the
1576 // locking has to be done very carefully to avoid deadlocks
1577 // and/or other cache consistency problems.
1578 //
1579 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1580 size_t idnum = (size_t)method_h->method_idnum();
1581 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1582 size_t length = 0;
1583 jmethodID id = NULL;
1585 // We use a double-check locking idiom here because this cache is
1586 // performance sensitive. In the normal system, this cache only
1587 // transitions from NULL to non-NULL which is safe because we use
1588 // release_set_methods_jmethod_ids() to advertise the new cache.
1589 // A partially constructed cache should never be seen by a racing
1590 // thread. We also use release_store_ptr() to save a new jmethodID
1591 // in the cache so a partially constructed jmethodID should never be
1592 // seen either. Cache reads of existing jmethodIDs proceed without a
1593 // lock, but cache writes of a new jmethodID requires uniqueness and
1594 // creation of the cache itself requires no leaks so a lock is
1595 // generally acquired in those two cases.
1596 //
1597 // If the RedefineClasses() API has been used, then this cache can
1598 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1599 // Cache creation requires no leaks and we require safety between all
1600 // cache accesses and freeing of the old cache so a lock is generally
1601 // acquired when the RedefineClasses() API has been used.
1603 if (jmeths != NULL) {
1604 // the cache already exists
1605 if (!ik_h->idnum_can_increment()) {
1606 // the cache can't grow so we can just get the current values
1607 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1608 } else {
1609 // cache can grow so we have to be more careful
1610 if (Threads::number_of_threads() == 0 ||
1611 SafepointSynchronize::is_at_safepoint()) {
1612 // we're single threaded or at a safepoint - no locking needed
1613 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1614 } else {
1615 MutexLocker ml(JmethodIdCreation_lock);
1616 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1617 }
1618 }
1619 }
1620 // implied else:
1621 // we need to allocate a cache so default length and id values are good
1623 if (jmeths == NULL || // no cache yet
1624 length <= idnum || // cache is too short
1625 id == NULL) { // cache doesn't contain entry
1627 // This function can be called by the VMThread so we have to do all
1628 // things that might block on a safepoint before grabbing the lock.
1629 // Otherwise, we can deadlock with the VMThread or have a cache
1630 // consistency issue. These vars keep track of what we might have
1631 // to free after the lock is dropped.
1632 jmethodID to_dealloc_id = NULL;
1633 jmethodID* to_dealloc_jmeths = NULL;
1635 // may not allocate new_jmeths or use it if we allocate it
1636 jmethodID* new_jmeths = NULL;
1637 if (length <= idnum) {
1638 // allocate a new cache that might be used
1639 size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1640 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1641 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1642 // cache size is stored in element[0], other elements offset by one
1643 new_jmeths[0] = (jmethodID)size;
1644 }
1646 // allocate a new jmethodID that might be used
1647 jmethodID new_id = NULL;
1648 if (method_h->is_old() && !method_h->is_obsolete()) {
1649 // The method passed in is old (but not obsolete), we need to use the current version
1650 Method* current_method = ik_h->method_with_idnum((int)idnum);
1651 assert(current_method != NULL, "old and but not obsolete, so should exist");
1652 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
1653 } else {
1654 // It is the current version of the method or an obsolete method,
1655 // use the version passed in
1656 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
1657 }
1659 if (Threads::number_of_threads() == 0 ||
1660 SafepointSynchronize::is_at_safepoint()) {
1661 // we're single threaded or at a safepoint - no locking needed
1662 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1663 &to_dealloc_id, &to_dealloc_jmeths);
1664 } else {
1665 MutexLocker ml(JmethodIdCreation_lock);
1666 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1667 &to_dealloc_id, &to_dealloc_jmeths);
1668 }
1670 // The lock has been dropped so we can free resources.
1671 // Free up either the old cache or the new cache if we allocated one.
1672 if (to_dealloc_jmeths != NULL) {
1673 FreeHeap(to_dealloc_jmeths);
1674 }
1675 // free up the new ID since it wasn't needed
1676 if (to_dealloc_id != NULL) {
1677 Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
1678 }
1679 }
1680 return id;
1681 }
1684 // Common code to fetch the jmethodID from the cache or update the
1685 // cache with the new jmethodID. This function should never do anything
1686 // that causes the caller to go to a safepoint or we can deadlock with
1687 // the VMThread or have cache consistency issues.
1688 //
1689 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1690 instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1691 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1692 jmethodID** to_dealloc_jmeths_p) {
1693 assert(new_id != NULL, "sanity check");
1694 assert(to_dealloc_id_p != NULL, "sanity check");
1695 assert(to_dealloc_jmeths_p != NULL, "sanity check");
1696 assert(Threads::number_of_threads() == 0 ||
1697 SafepointSynchronize::is_at_safepoint() ||
1698 JmethodIdCreation_lock->owned_by_self(), "sanity check");
1700 // reacquire the cache - we are locked, single threaded or at a safepoint
1701 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1702 jmethodID id = NULL;
1703 size_t length = 0;
1705 if (jmeths == NULL || // no cache yet
1706 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
1707 if (jmeths != NULL) {
1708 // copy any existing entries from the old cache
1709 for (size_t index = 0; index < length; index++) {
1710 new_jmeths[index+1] = jmeths[index+1];
1711 }
1712 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
1713 }
1714 ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1715 } else {
1716 // fetch jmethodID (if any) from the existing cache
1717 id = jmeths[idnum+1];
1718 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
1719 }
1720 if (id == NULL) {
1721 // No matching jmethodID in the existing cache or we have a new
1722 // cache or we just grew the cache. This cache write is done here
1723 // by the first thread to win the foot race because a jmethodID
1724 // needs to be unique once it is generally available.
1725 id = new_id;
1727 // The jmethodID cache can be read while unlocked so we have to
1728 // make sure the new jmethodID is complete before installing it
1729 // in the cache.
1730 OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1731 } else {
1732 *to_dealloc_id_p = new_id; // save new id for later delete
1733 }
1734 return id;
1735 }
1738 // Common code to get the jmethodID cache length and the jmethodID
1739 // value at index idnum if there is one.
1740 //
1741 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1742 size_t idnum, size_t *length_p, jmethodID* id_p) {
1743 assert(cache != NULL, "sanity check");
1744 assert(length_p != NULL, "sanity check");
1745 assert(id_p != NULL, "sanity check");
1747 // cache size is stored in element[0], other elements offset by one
1748 *length_p = (size_t)cache[0];
1749 if (*length_p <= idnum) { // cache is too short
1750 *id_p = NULL;
1751 } else {
1752 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
1753 }
1754 }
1757 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
1758 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1759 size_t idnum = (size_t)method->method_idnum();
1760 jmethodID* jmeths = methods_jmethod_ids_acquire();
1761 size_t length; // length assigned as debugging crumb
1762 jmethodID id = NULL;
1763 if (jmeths != NULL && // If there is a cache
1764 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
1765 id = jmeths[idnum+1]; // Look up the id (may be NULL)
1766 }
1767 return id;
1768 }
1771 //
1772 // Walk the list of dependent nmethods searching for nmethods which
1773 // are dependent on the changes that were passed in and mark them for
1774 // deoptimization. Returns the number of nmethods found.
1775 //
1776 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
1777 assert_locked_or_safepoint(CodeCache_lock);
1778 int found = 0;
1779 nmethodBucket* b = _dependencies;
1780 while (b != NULL) {
1781 nmethod* nm = b->get_nmethod();
1782 // since dependencies aren't removed until an nmethod becomes a zombie,
1783 // the dependency list may contain nmethods which aren't alive.
1784 if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1785 if (TraceDependencies) {
1786 ResourceMark rm;
1787 tty->print_cr("Marked for deoptimization");
1788 tty->print_cr(" context = %s", this->external_name());
1789 changes.print();
1790 nm->print();
1791 nm->print_dependencies();
1792 }
1793 nm->mark_for_deoptimization();
1794 found++;
1795 }
1796 b = b->next();
1797 }
1798 return found;
1799 }
1802 //
1803 // Add an nmethodBucket to the list of dependencies for this nmethod.
1804 // It's possible that an nmethod has multiple dependencies on this klass
1805 // so a count is kept for each bucket to guarantee that creation and
1806 // deletion of dependencies is consistent.
1807 //
1808 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1809 assert_locked_or_safepoint(CodeCache_lock);
1810 nmethodBucket* b = _dependencies;
1811 nmethodBucket* last = NULL;
1812 while (b != NULL) {
1813 if (nm == b->get_nmethod()) {
1814 b->increment();
1815 return;
1816 }
1817 b = b->next();
1818 }
1819 _dependencies = new nmethodBucket(nm, _dependencies);
1820 }
1823 //
1824 // Decrement count of the nmethod in the dependency list and remove
1825 // the bucket competely when the count goes to 0. This method must
1826 // find a corresponding bucket otherwise there's a bug in the
1827 // recording of dependecies.
1828 //
1829 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
1830 assert_locked_or_safepoint(CodeCache_lock);
1831 nmethodBucket* b = _dependencies;
1832 nmethodBucket* last = NULL;
1833 while (b != NULL) {
1834 if (nm == b->get_nmethod()) {
1835 if (b->decrement() == 0) {
1836 if (last == NULL) {
1837 _dependencies = b->next();
1838 } else {
1839 last->set_next(b->next());
1840 }
1841 delete b;
1842 }
1843 return;
1844 }
1845 last = b;
1846 b = b->next();
1847 }
1848 #ifdef ASSERT
1849 tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1850 nm->print();
1851 #endif // ASSERT
1852 ShouldNotReachHere();
1853 }
1856 #ifndef PRODUCT
1857 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1858 nmethodBucket* b = _dependencies;
1859 int idx = 0;
1860 while (b != NULL) {
1861 nmethod* nm = b->get_nmethod();
1862 tty->print("[%d] count=%d { ", idx++, b->count());
1863 if (!verbose) {
1864 nm->print_on(tty, "nmethod");
1865 tty->print_cr(" } ");
1866 } else {
1867 nm->print();
1868 nm->print_dependencies();
1869 tty->print_cr("--- } ");
1870 }
1871 b = b->next();
1872 }
1873 }
1876 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1877 nmethodBucket* b = _dependencies;
1878 while (b != NULL) {
1879 if (nm == b->get_nmethod()) {
1880 return true;
1881 }
1882 b = b->next();
1883 }
1884 return false;
1885 }
1886 #endif //PRODUCT
1889 // Garbage collection
1891 #ifdef ASSERT
1892 template <class T> void assert_is_in(T *p) {
1893 T heap_oop = oopDesc::load_heap_oop(p);
1894 if (!oopDesc::is_null(heap_oop)) {
1895 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1896 assert(Universe::heap()->is_in(o), "should be in heap");
1897 }
1898 }
1899 template <class T> void assert_is_in_closed_subset(T *p) {
1900 T heap_oop = oopDesc::load_heap_oop(p);
1901 if (!oopDesc::is_null(heap_oop)) {
1902 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1903 assert(Universe::heap()->is_in_closed_subset(o),
1904 err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
1905 }
1906 }
1907 template <class T> void assert_is_in_reserved(T *p) {
1908 T heap_oop = oopDesc::load_heap_oop(p);
1909 if (!oopDesc::is_null(heap_oop)) {
1910 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1911 assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
1912 }
1913 }
1914 template <class T> void assert_nothing(T *p) {}
1916 #else
1917 template <class T> void assert_is_in(T *p) {}
1918 template <class T> void assert_is_in_closed_subset(T *p) {}
1919 template <class T> void assert_is_in_reserved(T *p) {}
1920 template <class T> void assert_nothing(T *p) {}
1921 #endif // ASSERT
1923 //
1924 // Macros that iterate over areas of oops which are specialized on type of
1925 // oop pointer either narrow or wide, depending on UseCompressedOops
1926 //
1927 // Parameters are:
1928 // T - type of oop to point to (either oop or narrowOop)
1929 // start_p - starting pointer for region to iterate over
1930 // count - number of oops or narrowOops to iterate over
1931 // do_oop - action to perform on each oop (it's arbitrary C code which
1932 // makes it more efficient to put in a macro rather than making
1933 // it a template function)
1934 // assert_fn - assert function which is template function because performance
1935 // doesn't matter when enabled.
1936 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
1937 T, start_p, count, do_oop, \
1938 assert_fn) \
1939 { \
1940 T* p = (T*)(start_p); \
1941 T* const end = p + (count); \
1942 while (p < end) { \
1943 (assert_fn)(p); \
1944 do_oop; \
1945 ++p; \
1946 } \
1947 }
1949 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
1950 T, start_p, count, do_oop, \
1951 assert_fn) \
1952 { \
1953 T* const start = (T*)(start_p); \
1954 T* p = start + (count); \
1955 while (start < p) { \
1956 --p; \
1957 (assert_fn)(p); \
1958 do_oop; \
1959 } \
1960 }
1962 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
1963 T, start_p, count, low, high, \
1964 do_oop, assert_fn) \
1965 { \
1966 T* const l = (T*)(low); \
1967 T* const h = (T*)(high); \
1968 assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
1969 mask_bits((intptr_t)h, sizeof(T)-1) == 0, \
1970 "bounded region must be properly aligned"); \
1971 T* p = (T*)(start_p); \
1972 T* end = p + (count); \
1973 if (p < l) p = l; \
1974 if (end > h) end = h; \
1975 while (p < end) { \
1976 (assert_fn)(p); \
1977 do_oop; \
1978 ++p; \
1979 } \
1980 }
1983 // The following macros call specialized macros, passing either oop or
1984 // narrowOop as the specialization type. These test the UseCompressedOops
1985 // flag.
1986 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \
1987 { \
1988 /* Compute oopmap block range. The common case \
1989 is nonstatic_oop_map_size == 1. */ \
1990 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1991 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1992 if (UseCompressedOops) { \
1993 while (map < end_map) { \
1994 InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
1995 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1996 do_oop, assert_fn) \
1997 ++map; \
1998 } \
1999 } else { \
2000 while (map < end_map) { \
2001 InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
2002 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2003 do_oop, assert_fn) \
2004 ++map; \
2005 } \
2006 } \
2007 }
2009 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \
2010 { \
2011 OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \
2012 OopMapBlock* map = start_map + nonstatic_oop_map_count(); \
2013 if (UseCompressedOops) { \
2014 while (start_map < map) { \
2015 --map; \
2016 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \
2017 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
2018 do_oop, assert_fn) \
2019 } \
2020 } else { \
2021 while (start_map < map) { \
2022 --map; \
2023 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \
2024 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2025 do_oop, assert_fn) \
2026 } \
2027 } \
2028 }
2030 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \
2031 assert_fn) \
2032 { \
2033 /* Compute oopmap block range. The common case is \
2034 nonstatic_oop_map_size == 1, so we accept the \
2035 usually non-existent extra overhead of examining \
2036 all the maps. */ \
2037 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
2038 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
2039 if (UseCompressedOops) { \
2040 while (map < end_map) { \
2041 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
2042 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
2043 low, high, \
2044 do_oop, assert_fn) \
2045 ++map; \
2046 } \
2047 } else { \
2048 while (map < end_map) { \
2049 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
2050 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2051 low, high, \
2052 do_oop, assert_fn) \
2053 ++map; \
2054 } \
2055 } \
2056 }
2058 void InstanceKlass::oop_follow_contents(oop obj) {
2059 assert(obj != NULL, "can't follow the content of NULL object");
2060 MarkSweep::follow_klass(obj->klass());
2061 InstanceKlass_OOP_MAP_ITERATE( \
2062 obj, \
2063 MarkSweep::mark_and_push(p), \
2064 assert_is_in_closed_subset)
2065 }
2067 #if INCLUDE_ALL_GCS
2068 void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
2069 oop obj) {
2070 assert(obj != NULL, "can't follow the content of NULL object");
2071 PSParallelCompact::follow_klass(cm, obj->klass());
2072 // Only mark the header and let the scan of the meta-data mark
2073 // everything else.
2074 InstanceKlass_OOP_MAP_ITERATE( \
2075 obj, \
2076 PSParallelCompact::mark_and_push(cm, p), \
2077 assert_is_in)
2078 }
2079 #endif // INCLUDE_ALL_GCS
2081 // closure's do_metadata() method dictates whether the given closure should be
2082 // applied to the klass ptr in the object header.
2084 #define if_do_metadata_checked(closure, nv_suffix) \
2085 /* Make sure the non-virtual and the virtual versions match. */ \
2086 assert(closure->do_metadata##nv_suffix() == closure->do_metadata(), \
2087 "Inconsistency in do_metadata"); \
2088 if (closure->do_metadata##nv_suffix())
2090 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
2091 \
2092 int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
2093 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2094 /* header */ \
2095 if_do_metadata_checked(closure, nv_suffix) { \
2096 closure->do_klass##nv_suffix(obj->klass()); \
2097 } \
2098 InstanceKlass_OOP_MAP_ITERATE( \
2099 obj, \
2100 SpecializationStats:: \
2101 record_do_oop_call##nv_suffix(SpecializationStats::ik); \
2102 (closure)->do_oop##nv_suffix(p), \
2103 assert_is_in_closed_subset) \
2104 return size_helper(); \
2105 }
2107 #if INCLUDE_ALL_GCS
2108 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
2109 \
2110 int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \
2111 OopClosureType* closure) { \
2112 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
2113 /* header */ \
2114 if_do_metadata_checked(closure, nv_suffix) { \
2115 closure->do_klass##nv_suffix(obj->klass()); \
2116 } \
2117 /* instance variables */ \
2118 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2119 obj, \
2120 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
2121 (closure)->do_oop##nv_suffix(p), \
2122 assert_is_in_closed_subset) \
2123 return size_helper(); \
2124 }
2125 #endif // INCLUDE_ALL_GCS
2127 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
2128 \
2129 int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \
2130 OopClosureType* closure, \
2131 MemRegion mr) { \
2132 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2133 if_do_metadata_checked(closure, nv_suffix) { \
2134 if (mr.contains(obj)) { \
2135 closure->do_klass##nv_suffix(obj->klass()); \
2136 } \
2137 } \
2138 InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
2139 obj, mr.start(), mr.end(), \
2140 (closure)->do_oop##nv_suffix(p), \
2141 assert_is_in_closed_subset) \
2142 return size_helper(); \
2143 }
2145 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2146 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2147 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2148 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2149 #if INCLUDE_ALL_GCS
2150 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2151 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2152 #endif // INCLUDE_ALL_GCS
2154 int InstanceKlass::oop_adjust_pointers(oop obj) {
2155 int size = size_helper();
2156 InstanceKlass_OOP_MAP_ITERATE( \
2157 obj, \
2158 MarkSweep::adjust_pointer(p), \
2159 assert_is_in)
2160 return size;
2161 }
2163 #if INCLUDE_ALL_GCS
2164 void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
2165 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2166 obj, \
2167 if (PSScavenge::should_scavenge(p)) { \
2168 pm->claim_or_forward_depth(p); \
2169 }, \
2170 assert_nothing )
2171 }
2173 int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
2174 int size = size_helper();
2175 InstanceKlass_OOP_MAP_ITERATE( \
2176 obj, \
2177 PSParallelCompact::adjust_pointer(p), \
2178 assert_is_in)
2179 obj->update_header(cm);
2180 return size;
2181 }
2183 #endif // INCLUDE_ALL_GCS
2185 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
2186 assert(is_loader_alive(is_alive), "this klass should be live");
2187 if (is_interface()) {
2188 if (ClassUnloading) {
2189 Klass* impl = implementor();
2190 if (impl != NULL) {
2191 if (!impl->is_loader_alive(is_alive)) {
2192 // remove this guy
2193 Klass** klass = adr_implementor();
2194 assert(klass != NULL, "null klass");
2195 if (klass != NULL) {
2196 *klass = NULL;
2197 }
2198 }
2199 }
2200 }
2201 }
2202 }
2204 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
2205 for (int m = 0; m < methods()->length(); m++) {
2206 MethodData* mdo = methods()->at(m)->method_data();
2207 if (mdo != NULL) {
2208 for (ProfileData* data = mdo->first_data();
2209 mdo->is_valid(data);
2210 data = mdo->next_data(data)) {
2211 data->clean_weak_klass_links(is_alive);
2212 }
2213 ParametersTypeData* parameters = mdo->parameters_type_data();
2214 if (parameters != NULL) {
2215 parameters->clean_weak_klass_links(is_alive);
2216 }
2217 }
2218 }
2219 }
2222 static void remove_unshareable_in_class(Klass* k) {
2223 // remove klass's unshareable info
2224 k->remove_unshareable_info();
2225 }
2227 void InstanceKlass::remove_unshareable_info() {
2228 Klass::remove_unshareable_info();
2229 // Unlink the class
2230 if (is_linked()) {
2231 unlink_class();
2232 }
2233 init_implementor();
2235 constants()->remove_unshareable_info();
2237 for (int i = 0; i < methods()->length(); i++) {
2238 Method* m = methods()->at(i);
2239 m->remove_unshareable_info();
2240 }
2242 // do array classes also.
2243 array_klasses_do(remove_unshareable_in_class);
2244 }
2246 void restore_unshareable_in_class(Klass* k, TRAPS) {
2247 k->restore_unshareable_info(CHECK);
2248 }
2250 void InstanceKlass::restore_unshareable_info(TRAPS) {
2251 Klass::restore_unshareable_info(CHECK);
2252 instanceKlassHandle ik(THREAD, this);
2254 Array<Method*>* methods = ik->methods();
2255 int num_methods = methods->length();
2256 for (int index2 = 0; index2 < num_methods; ++index2) {
2257 methodHandle m(THREAD, methods->at(index2));
2258 m()->link_method(m, CHECK);
2259 // restore method's vtable by calling a virtual function
2260 m->restore_vtable();
2261 }
2262 if (JvmtiExport::has_redefined_a_class()) {
2263 // Reinitialize vtable because RedefineClasses may have changed some
2264 // entries in this vtable for super classes so the CDS vtable might
2265 // point to old or obsolete entries. RedefineClasses doesn't fix up
2266 // vtables in the shared system dictionary, only the main one.
2267 // It also redefines the itable too so fix that too.
2268 ResourceMark rm(THREAD);
2269 ik->vtable()->initialize_vtable(false, CHECK);
2270 ik->itable()->initialize_itable(false, CHECK);
2271 }
2273 // restore constant pool resolved references
2274 ik->constants()->restore_unshareable_info(CHECK);
2276 ik->array_klasses_do(restore_unshareable_in_class, CHECK);
2277 }
2279 static void clear_all_breakpoints(Method* m) {
2280 m->clear_all_breakpoints();
2281 }
2284 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2285 // notify the debugger
2286 if (JvmtiExport::should_post_class_unload()) {
2287 JvmtiExport::post_class_unload(ik);
2288 }
2290 // notify ClassLoadingService of class unload
2291 ClassLoadingService::notify_class_unloaded(ik);
2292 }
2294 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2295 // Clean up C heap
2296 ik->release_C_heap_structures();
2297 ik->constants()->release_C_heap_structures();
2298 }
2300 void InstanceKlass::release_C_heap_structures() {
2302 // Can't release the constant pool here because the constant pool can be
2303 // deallocated separately from the InstanceKlass for default methods and
2304 // redefine classes.
2306 // Deallocate oop map cache
2307 if (_oop_map_cache != NULL) {
2308 delete _oop_map_cache;
2309 _oop_map_cache = NULL;
2310 }
2312 // Deallocate JNI identifiers for jfieldIDs
2313 JNIid::deallocate(jni_ids());
2314 set_jni_ids(NULL);
2316 jmethodID* jmeths = methods_jmethod_ids_acquire();
2317 if (jmeths != (jmethodID*)NULL) {
2318 release_set_methods_jmethod_ids(NULL);
2319 FreeHeap(jmeths);
2320 }
2322 // Deallocate MemberNameTable
2323 {
2324 Mutex* lock_or_null = SafepointSynchronize::is_at_safepoint() ? NULL : MemberNameTable_lock;
2325 MutexLockerEx ml(lock_or_null, Mutex::_no_safepoint_check_flag);
2326 MemberNameTable* mnt = member_names();
2327 if (mnt != NULL) {
2328 delete mnt;
2329 set_member_names(NULL);
2330 }
2331 }
2333 // release dependencies
2334 nmethodBucket* b = _dependencies;
2335 _dependencies = NULL;
2336 while (b != NULL) {
2337 nmethodBucket* next = b->next();
2338 delete b;
2339 b = next;
2340 }
2342 // Deallocate breakpoint records
2343 if (breakpoints() != 0x0) {
2344 methods_do(clear_all_breakpoints);
2345 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2346 }
2348 // deallocate information about previous versions
2349 if (_previous_versions != NULL) {
2350 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
2351 PreviousVersionNode * pv_node = _previous_versions->at(i);
2352 delete pv_node;
2353 }
2354 delete _previous_versions;
2355 _previous_versions = NULL;
2356 }
2358 // deallocate the cached class file
2359 if (_cached_class_file != NULL) {
2360 os::free(_cached_class_file, mtClass);
2361 _cached_class_file = NULL;
2362 }
2364 // Decrement symbol reference counts associated with the unloaded class.
2365 if (_name != NULL) _name->decrement_refcount();
2366 // unreference array name derived from this class name (arrays of an unloaded
2367 // class can't be referenced anymore).
2368 if (_array_name != NULL) _array_name->decrement_refcount();
2369 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
2371 assert(_total_instanceKlass_count >= 1, "Sanity check");
2372 Atomic::dec(&_total_instanceKlass_count);
2373 }
2375 void InstanceKlass::set_source_debug_extension(char* array, int length) {
2376 if (array == NULL) {
2377 _source_debug_extension = NULL;
2378 } else {
2379 // Adding one to the attribute length in order to store a null terminator
2380 // character could cause an overflow because the attribute length is
2381 // already coded with an u4 in the classfile, but in practice, it's
2382 // unlikely to happen.
2383 assert((length+1) > length, "Overflow checking");
2384 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2385 for (int i = 0; i < length; i++) {
2386 sde[i] = array[i];
2387 }
2388 sde[length] = '\0';
2389 _source_debug_extension = sde;
2390 }
2391 }
2393 address InstanceKlass::static_field_addr(int offset) {
2394 return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
2395 }
2398 const char* InstanceKlass::signature_name() const {
2399 int hash_len = 0;
2400 char hash_buf[40];
2402 // If this is an anonymous class, append a hash to make the name unique
2403 if (is_anonymous()) {
2404 assert(EnableInvokeDynamic, "EnableInvokeDynamic was not set.");
2405 intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2406 sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
2407 hash_len = (int)strlen(hash_buf);
2408 }
2410 // Get the internal name as a c string
2411 const char* src = (const char*) (name()->as_C_string());
2412 const int src_length = (int)strlen(src);
2414 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2416 // Add L as type indicator
2417 int dest_index = 0;
2418 dest[dest_index++] = 'L';
2420 // Add the actual class name
2421 for (int src_index = 0; src_index < src_length; ) {
2422 dest[dest_index++] = src[src_index++];
2423 }
2425 // If we have a hash, append it
2426 for (int hash_index = 0; hash_index < hash_len; ) {
2427 dest[dest_index++] = hash_buf[hash_index++];
2428 }
2430 // Add the semicolon and the NULL
2431 dest[dest_index++] = ';';
2432 dest[dest_index] = '\0';
2433 return dest;
2434 }
2436 // different verisons of is_same_class_package
2437 bool InstanceKlass::is_same_class_package(Klass* class2) {
2438 Klass* class1 = this;
2439 oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2440 Symbol* classname1 = class1->name();
2442 if (class2->oop_is_objArray()) {
2443 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2444 }
2445 oop classloader2;
2446 if (class2->oop_is_instance()) {
2447 classloader2 = InstanceKlass::cast(class2)->class_loader();
2448 } else {
2449 assert(class2->oop_is_typeArray(), "should be type array");
2450 classloader2 = NULL;
2451 }
2452 Symbol* classname2 = class2->name();
2454 return InstanceKlass::is_same_class_package(classloader1, classname1,
2455 classloader2, classname2);
2456 }
2458 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
2459 Klass* class1 = this;
2460 oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2461 Symbol* classname1 = class1->name();
2463 return InstanceKlass::is_same_class_package(classloader1, classname1,
2464 classloader2, classname2);
2465 }
2467 // return true if two classes are in the same package, classloader
2468 // and classname information is enough to determine a class's package
2469 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
2470 oop class_loader2, Symbol* class_name2) {
2471 if (class_loader1 != class_loader2) {
2472 return false;
2473 } else if (class_name1 == class_name2) {
2474 return true; // skip painful bytewise comparison
2475 } else {
2476 ResourceMark rm;
2478 // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
2479 // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
2480 // Otherwise, we just compare jbyte values between the strings.
2481 const jbyte *name1 = class_name1->base();
2482 const jbyte *name2 = class_name2->base();
2484 const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
2485 const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
2487 if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
2488 // One of the two doesn't have a package. Only return true
2489 // if the other one also doesn't have a package.
2490 return last_slash1 == last_slash2;
2491 } else {
2492 // Skip over '['s
2493 if (*name1 == '[') {
2494 do {
2495 name1++;
2496 } while (*name1 == '[');
2497 if (*name1 != 'L') {
2498 // Something is terribly wrong. Shouldn't be here.
2499 return false;
2500 }
2501 }
2502 if (*name2 == '[') {
2503 do {
2504 name2++;
2505 } while (*name2 == '[');
2506 if (*name2 != 'L') {
2507 // Something is terribly wrong. Shouldn't be here.
2508 return false;
2509 }
2510 }
2512 // Check that package part is identical
2513 int length1 = last_slash1 - name1;
2514 int length2 = last_slash2 - name2;
2516 return UTF8::equal(name1, length1, name2, length2);
2517 }
2518 }
2519 }
2521 // Returns true iff super_method can be overridden by a method in targetclassname
2522 // See JSL 3rd edition 8.4.6.1
2523 // Assumes name-signature match
2524 // "this" is InstanceKlass of super_method which must exist
2525 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2526 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2527 // Private methods can not be overridden
2528 if (super_method->is_private()) {
2529 return false;
2530 }
2531 // If super method is accessible, then override
2532 if ((super_method->is_protected()) ||
2533 (super_method->is_public())) {
2534 return true;
2535 }
2536 // Package-private methods are not inherited outside of package
2537 assert(super_method->is_package_private(), "must be package private");
2538 return(is_same_class_package(targetclassloader(), targetclassname));
2539 }
2541 /* defined for now in jvm.cpp, for historical reasons *--
2542 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2543 Symbol*& simple_name_result, TRAPS) {
2544 ...
2545 }
2546 */
2548 // tell if two classes have the same enclosing class (at package level)
2549 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2550 Klass* class2_oop, TRAPS) {
2551 if (class2_oop == class1()) return true;
2552 if (!class2_oop->oop_is_instance()) return false;
2553 instanceKlassHandle class2(THREAD, class2_oop);
2555 // must be in same package before we try anything else
2556 if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2557 return false;
2559 // As long as there is an outer1.getEnclosingClass,
2560 // shift the search outward.
2561 instanceKlassHandle outer1 = class1;
2562 for (;;) {
2563 // As we walk along, look for equalities between outer1 and class2.
2564 // Eventually, the walks will terminate as outer1 stops
2565 // at the top-level class around the original class.
2566 bool ignore_inner_is_member;
2567 Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2568 CHECK_false);
2569 if (next == NULL) break;
2570 if (next == class2()) return true;
2571 outer1 = instanceKlassHandle(THREAD, next);
2572 }
2574 // Now do the same for class2.
2575 instanceKlassHandle outer2 = class2;
2576 for (;;) {
2577 bool ignore_inner_is_member;
2578 Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2579 CHECK_false);
2580 if (next == NULL) break;
2581 // Might as well check the new outer against all available values.
2582 if (next == class1()) return true;
2583 if (next == outer1()) return true;
2584 outer2 = instanceKlassHandle(THREAD, next);
2585 }
2587 // If by this point we have not found an equality between the
2588 // two classes, we know they are in separate package members.
2589 return false;
2590 }
2593 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2594 jint access = access_flags().as_int();
2596 // But check if it happens to be member class.
2597 instanceKlassHandle ik(THREAD, this);
2598 InnerClassesIterator iter(ik);
2599 for (; !iter.done(); iter.next()) {
2600 int ioff = iter.inner_class_info_index();
2601 // Inner class attribute can be zero, skip it.
2602 // Strange but true: JVM spec. allows null inner class refs.
2603 if (ioff == 0) continue;
2605 // only look at classes that are already loaded
2606 // since we are looking for the flags for our self.
2607 Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2608 if ((ik->name() == inner_name)) {
2609 // This is really a member class.
2610 access = iter.inner_access_flags();
2611 break;
2612 }
2613 }
2614 // Remember to strip ACC_SUPER bit
2615 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2616 }
2618 jint InstanceKlass::jvmti_class_status() const {
2619 jint result = 0;
2621 if (is_linked()) {
2622 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2623 }
2625 if (is_initialized()) {
2626 assert(is_linked(), "Class status is not consistent");
2627 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2628 }
2629 if (is_in_error_state()) {
2630 result |= JVMTI_CLASS_STATUS_ERROR;
2631 }
2632 return result;
2633 }
2635 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2636 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2637 int method_table_offset_in_words = ioe->offset()/wordSize;
2638 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2639 / itableOffsetEntry::size();
2641 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2642 // If the interface isn't implemented by the receiver class,
2643 // the VM should throw IncompatibleClassChangeError.
2644 if (cnt >= nof_interfaces) {
2645 THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2646 }
2648 Klass* ik = ioe->interface_klass();
2649 if (ik == holder) break;
2650 }
2652 itableMethodEntry* ime = ioe->first_method_entry(this);
2653 Method* m = ime[index].method();
2654 if (m == NULL) {
2655 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2656 }
2657 return m;
2658 }
2661 #if INCLUDE_JVMTI
2662 // update default_methods for redefineclasses for methods that are
2663 // not yet in the vtable due to concurrent subclass define and superinterface
2664 // redefinition
2665 // Note: those in the vtable, should have been updated via adjust_method_entries
2666 void InstanceKlass::adjust_default_methods(Method** old_methods, Method** new_methods,
2667 int methods_length, bool* trace_name_printed) {
2668 // search the default_methods for uses of either obsolete or EMCP methods
2669 if (default_methods() != NULL) {
2670 for (int j = 0; j < methods_length; j++) {
2671 Method* old_method = old_methods[j];
2672 Method* new_method = new_methods[j];
2674 for (int index = 0; index < default_methods()->length(); index ++) {
2675 if (default_methods()->at(index) == old_method) {
2676 default_methods()->at_put(index, new_method);
2677 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
2678 if (!(*trace_name_printed)) {
2679 // RC_TRACE_MESG macro has an embedded ResourceMark
2680 RC_TRACE_MESG(("adjust: klassname=%s default methods from name=%s",
2681 external_name(),
2682 old_method->method_holder()->external_name()));
2683 *trace_name_printed = true;
2684 }
2685 RC_TRACE(0x00100000, ("default method update: %s(%s) ",
2686 new_method->name()->as_C_string(),
2687 new_method->signature()->as_C_string()));
2688 }
2689 }
2690 }
2691 }
2692 }
2693 }
2694 #endif // INCLUDE_JVMTI
2696 // On-stack replacement stuff
2697 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2698 // only one compilation can be active
2699 NEEDS_CLEANUP
2700 // This is a short non-blocking critical region, so the no safepoint check is ok.
2701 OsrList_lock->lock_without_safepoint_check();
2702 assert(n->is_osr_method(), "wrong kind of nmethod");
2703 n->set_osr_link(osr_nmethods_head());
2704 set_osr_nmethods_head(n);
2705 // Raise the highest osr level if necessary
2706 if (TieredCompilation) {
2707 Method* m = n->method();
2708 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2709 }
2710 // Remember to unlock again
2711 OsrList_lock->unlock();
2713 // Get rid of the osr methods for the same bci that have lower levels.
2714 if (TieredCompilation) {
2715 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2716 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2717 if (inv != NULL && inv->is_in_use()) {
2718 inv->make_not_entrant();
2719 }
2720 }
2721 }
2722 }
2725 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
2726 // This is a short non-blocking critical region, so the no safepoint check is ok.
2727 OsrList_lock->lock_without_safepoint_check();
2728 assert(n->is_osr_method(), "wrong kind of nmethod");
2729 nmethod* last = NULL;
2730 nmethod* cur = osr_nmethods_head();
2731 int max_level = CompLevel_none; // Find the max comp level excluding n
2732 Method* m = n->method();
2733 // Search for match
2734 while(cur != NULL && cur != n) {
2735 if (TieredCompilation) {
2736 // Find max level before n
2737 max_level = MAX2(max_level, cur->comp_level());
2738 }
2739 last = cur;
2740 cur = cur->osr_link();
2741 }
2742 nmethod* next = NULL;
2743 if (cur == n) {
2744 next = cur->osr_link();
2745 if (last == NULL) {
2746 // Remove first element
2747 set_osr_nmethods_head(next);
2748 } else {
2749 last->set_osr_link(next);
2750 }
2751 }
2752 n->set_osr_link(NULL);
2753 if (TieredCompilation) {
2754 cur = next;
2755 while (cur != NULL) {
2756 // Find max level after n
2757 max_level = MAX2(max_level, cur->comp_level());
2758 cur = cur->osr_link();
2759 }
2760 m->set_highest_osr_comp_level(max_level);
2761 }
2762 // Remember to unlock again
2763 OsrList_lock->unlock();
2764 }
2766 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2767 // This is a short non-blocking critical region, so the no safepoint check is ok.
2768 OsrList_lock->lock_without_safepoint_check();
2769 nmethod* osr = osr_nmethods_head();
2770 nmethod* best = NULL;
2771 while (osr != NULL) {
2772 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2773 // There can be a time when a c1 osr method exists but we are waiting
2774 // for a c2 version. When c2 completes its osr nmethod we will trash
2775 // the c1 version and only be able to find the c2 version. However
2776 // while we overflow in the c1 code at back branches we don't want to
2777 // try and switch to the same code as we are already running
2779 if (osr->method() == m &&
2780 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2781 if (match_level) {
2782 if (osr->comp_level() == comp_level) {
2783 // Found a match - return it.
2784 OsrList_lock->unlock();
2785 return osr;
2786 }
2787 } else {
2788 if (best == NULL || (osr->comp_level() > best->comp_level())) {
2789 if (osr->comp_level() == CompLevel_highest_tier) {
2790 // Found the best possible - return it.
2791 OsrList_lock->unlock();
2792 return osr;
2793 }
2794 best = osr;
2795 }
2796 }
2797 }
2798 osr = osr->osr_link();
2799 }
2800 OsrList_lock->unlock();
2801 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2802 return best;
2803 }
2804 return NULL;
2805 }
2807 void InstanceKlass::add_member_name(int index, Handle mem_name) {
2808 jweak mem_name_wref = JNIHandles::make_weak_global(mem_name);
2809 MutexLocker ml(MemberNameTable_lock);
2810 assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
2811 DEBUG_ONLY(No_Safepoint_Verifier nsv);
2813 if (_member_names == NULL) {
2814 _member_names = new (ResourceObj::C_HEAP, mtClass) MemberNameTable(idnum_allocated_count());
2815 }
2816 _member_names->add_member_name(index, mem_name_wref);
2817 }
2819 oop InstanceKlass::get_member_name(int index) {
2820 MutexLocker ml(MemberNameTable_lock);
2821 assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
2822 DEBUG_ONLY(No_Safepoint_Verifier nsv);
2824 if (_member_names == NULL) {
2825 return NULL;
2826 }
2827 oop mem_name =_member_names->get_member_name(index);
2828 return mem_name;
2829 }
2831 // -----------------------------------------------------------------------------------------------------
2832 // Printing
2834 #ifndef PRODUCT
2836 #define BULLET " - "
2838 static const char* state_names[] = {
2839 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2840 };
2842 static void print_vtable(intptr_t* start, int len, outputStream* st) {
2843 for (int i = 0; i < len; i++) {
2844 intptr_t e = start[i];
2845 st->print("%d : " INTPTR_FORMAT, i, e);
2846 if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2847 st->print(" ");
2848 ((Metadata*)e)->print_value_on(st);
2849 }
2850 st->cr();
2851 }
2852 }
2854 void InstanceKlass::print_on(outputStream* st) const {
2855 assert(is_klass(), "must be klass");
2856 Klass::print_on(st);
2858 st->print(BULLET"instance size: %d", size_helper()); st->cr();
2859 st->print(BULLET"klass size: %d", size()); st->cr();
2860 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
2861 st->print(BULLET"state: "); st->print_cr(state_names[_init_state]);
2862 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
2863 st->print(BULLET"super: "); super()->print_value_on_maybe_null(st); st->cr();
2864 st->print(BULLET"sub: ");
2865 Klass* sub = subklass();
2866 int n;
2867 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2868 if (n < MaxSubklassPrintSize) {
2869 sub->print_value_on(st);
2870 st->print(" ");
2871 }
2872 }
2873 if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
2874 st->cr();
2876 if (is_interface()) {
2877 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
2878 if (nof_implementors() == 1) {
2879 st->print_cr(BULLET"implementor: ");
2880 st->print(" ");
2881 implementor()->print_value_on(st);
2882 st->cr();
2883 }
2884 }
2886 st->print(BULLET"arrays: "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2887 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
2888 if (Verbose || WizardMode) {
2889 Array<Method*>* method_array = methods();
2890 for (int i = 0; i < method_array->length(); i++) {
2891 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2892 }
2893 }
2894 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
2895 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
2896 if (Verbose && default_methods() != NULL) {
2897 Array<Method*>* method_array = default_methods();
2898 for (int i = 0; i < method_array->length(); i++) {
2899 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2900 }
2901 }
2902 if (default_vtable_indices() != NULL) {
2903 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
2904 }
2905 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
2906 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2907 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
2908 if (class_loader_data() != NULL) {
2909 st->print(BULLET"class loader data: ");
2910 class_loader_data()->print_value_on(st);
2911 st->cr();
2912 }
2913 st->print(BULLET"host class: "); host_klass()->print_value_on_maybe_null(st); st->cr();
2914 if (source_file_name() != NULL) {
2915 st->print(BULLET"source file: ");
2916 source_file_name()->print_value_on(st);
2917 st->cr();
2918 }
2919 if (source_debug_extension() != NULL) {
2920 st->print(BULLET"source debug extension: ");
2921 st->print("%s", source_debug_extension());
2922 st->cr();
2923 }
2924 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
2925 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
2926 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
2927 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
2928 {
2929 bool have_pv = false;
2930 PreviousVersionWalker pvw(Thread::current(), (InstanceKlass*)this);
2931 for (PreviousVersionNode * pv_node = pvw.next_previous_version();
2932 pv_node != NULL; pv_node = pvw.next_previous_version()) {
2933 if (!have_pv)
2934 st->print(BULLET"previous version: ");
2935 have_pv = true;
2936 pv_node->prev_constant_pool()->print_value_on(st);
2937 }
2938 if (have_pv) st->cr();
2939 } // pvw is cleaned up
2941 if (generic_signature() != NULL) {
2942 st->print(BULLET"generic signature: ");
2943 generic_signature()->print_value_on(st);
2944 st->cr();
2945 }
2946 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
2947 st->print(BULLET"java mirror: "); java_mirror()->print_value_on(st); st->cr();
2948 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable()); st->cr();
2949 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
2950 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
2951 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
2952 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2953 FieldPrinter print_static_field(st);
2954 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2955 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2956 FieldPrinter print_nonstatic_field(st);
2957 ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
2959 st->print(BULLET"non-static oop maps: ");
2960 OopMapBlock* map = start_of_nonstatic_oop_maps();
2961 OopMapBlock* end_map = map + nonstatic_oop_map_count();
2962 while (map < end_map) {
2963 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2964 map++;
2965 }
2966 st->cr();
2967 }
2969 #endif //PRODUCT
2971 void InstanceKlass::print_value_on(outputStream* st) const {
2972 assert(is_klass(), "must be klass");
2973 if (Verbose || WizardMode) access_flags().print_on(st);
2974 name()->print_value_on(st);
2975 }
2977 #ifndef PRODUCT
2979 void FieldPrinter::do_field(fieldDescriptor* fd) {
2980 _st->print(BULLET);
2981 if (_obj == NULL) {
2982 fd->print_on(_st);
2983 _st->cr();
2984 } else {
2985 fd->print_on_for(_st, _obj);
2986 _st->cr();
2987 }
2988 }
2991 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
2992 Klass::oop_print_on(obj, st);
2994 if (this == SystemDictionary::String_klass()) {
2995 typeArrayOop value = java_lang_String::value(obj);
2996 juint offset = java_lang_String::offset(obj);
2997 juint length = java_lang_String::length(obj);
2998 if (value != NULL &&
2999 value->is_typeArray() &&
3000 offset <= (juint) value->length() &&
3001 offset + length <= (juint) value->length()) {
3002 st->print(BULLET"string: ");
3003 Handle h_obj(obj);
3004 java_lang_String::print(h_obj, st);
3005 st->cr();
3006 if (!WizardMode) return; // that is enough
3007 }
3008 }
3010 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3011 FieldPrinter print_field(st, obj);
3012 do_nonstatic_fields(&print_field);
3014 if (this == SystemDictionary::Class_klass()) {
3015 st->print(BULLET"signature: ");
3016 java_lang_Class::print_signature(obj, st);
3017 st->cr();
3018 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3019 st->print(BULLET"fake entry for mirror: ");
3020 mirrored_klass->print_value_on_maybe_null(st);
3021 st->cr();
3022 Klass* array_klass = java_lang_Class::array_klass(obj);
3023 st->print(BULLET"fake entry for array: ");
3024 array_klass->print_value_on_maybe_null(st);
3025 st->cr();
3026 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3027 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3028 Klass* real_klass = java_lang_Class::as_Klass(obj);
3029 if (real_klass != NULL && real_klass->oop_is_instance()) {
3030 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3031 }
3032 } else if (this == SystemDictionary::MethodType_klass()) {
3033 st->print(BULLET"signature: ");
3034 java_lang_invoke_MethodType::print_signature(obj, st);
3035 st->cr();
3036 }
3037 }
3039 #endif //PRODUCT
3041 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3042 st->print("a ");
3043 name()->print_value_on(st);
3044 obj->print_address_on(st);
3045 if (this == SystemDictionary::String_klass()
3046 && java_lang_String::value(obj) != NULL) {
3047 ResourceMark rm;
3048 int len = java_lang_String::length(obj);
3049 int plen = (len < 24 ? len : 12);
3050 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3051 st->print(" = \"%s\"", str);
3052 if (len > plen)
3053 st->print("...[%d]", len);
3054 } else if (this == SystemDictionary::Class_klass()) {
3055 Klass* k = java_lang_Class::as_Klass(obj);
3056 st->print(" = ");
3057 if (k != NULL) {
3058 k->print_value_on(st);
3059 } else {
3060 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3061 st->print("%s", tname ? tname : "type?");
3062 }
3063 } else if (this == SystemDictionary::MethodType_klass()) {
3064 st->print(" = ");
3065 java_lang_invoke_MethodType::print_signature(obj, st);
3066 } else if (java_lang_boxing_object::is_instance(obj)) {
3067 st->print(" = ");
3068 java_lang_boxing_object::print(obj, st);
3069 } else if (this == SystemDictionary::LambdaForm_klass()) {
3070 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3071 if (vmentry != NULL) {
3072 st->print(" => ");
3073 vmentry->print_value_on(st);
3074 }
3075 } else if (this == SystemDictionary::MemberName_klass()) {
3076 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3077 if (vmtarget != NULL) {
3078 st->print(" = ");
3079 vmtarget->print_value_on(st);
3080 } else {
3081 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3082 st->print(".");
3083 java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3084 }
3085 }
3086 }
3088 const char* InstanceKlass::internal_name() const {
3089 return external_name();
3090 }
3092 #if INCLUDE_SERVICES
3093 // Size Statistics
3094 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3095 Klass::collect_statistics(sz);
3097 sz->_inst_size = HeapWordSize * size_helper();
3098 sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
3099 sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
3100 sz->_nonstatic_oopmap_bytes = HeapWordSize *
3101 ((is_interface() || is_anonymous()) ?
3102 align_object_offset(nonstatic_oop_map_size()) :
3103 nonstatic_oop_map_size());
3105 int n = 0;
3106 n += (sz->_methods_array_bytes = sz->count_array(methods()));
3107 n += (sz->_method_ordering_bytes = sz->count_array(method_ordering()));
3108 n += (sz->_local_interfaces_bytes = sz->count_array(local_interfaces()));
3109 n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3110 n += (sz->_fields_bytes = sz->count_array(fields()));
3111 n += (sz->_inner_classes_bytes = sz->count_array(inner_classes()));
3112 sz->_ro_bytes += n;
3114 const ConstantPool* cp = constants();
3115 if (cp) {
3116 cp->collect_statistics(sz);
3117 }
3119 const Annotations* anno = annotations();
3120 if (anno) {
3121 anno->collect_statistics(sz);
3122 }
3124 const Array<Method*>* methods_array = methods();
3125 if (methods()) {
3126 for (int i = 0; i < methods_array->length(); i++) {
3127 Method* method = methods_array->at(i);
3128 if (method) {
3129 sz->_method_count ++;
3130 method->collect_statistics(sz);
3131 }
3132 }
3133 }
3134 }
3135 #endif // INCLUDE_SERVICES
3137 // Verification
3139 class VerifyFieldClosure: public OopClosure {
3140 protected:
3141 template <class T> void do_oop_work(T* p) {
3142 oop obj = oopDesc::load_decode_heap_oop(p);
3143 if (!obj->is_oop_or_null()) {
3144 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
3145 Universe::print();
3146 guarantee(false, "boom");
3147 }
3148 }
3149 public:
3150 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3151 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3152 };
3154 void InstanceKlass::verify_on(outputStream* st, bool check_dictionary) {
3155 #ifndef PRODUCT
3156 // Avoid redundant verifies, this really should be in product.
3157 if (_verify_count == Universe::verify_count()) return;
3158 _verify_count = Universe::verify_count();
3159 #endif
3161 // Verify Klass
3162 Klass::verify_on(st, check_dictionary);
3164 // Verify that klass is present in SystemDictionary if not already
3165 // verifying the SystemDictionary.
3166 if (is_loaded() && !is_anonymous() && check_dictionary) {
3167 Symbol* h_name = name();
3168 SystemDictionary::verify_obj_klass_present(h_name, class_loader_data());
3169 }
3171 // Verify vtables
3172 if (is_linked()) {
3173 ResourceMark rm;
3174 // $$$ This used to be done only for m/s collections. Doing it
3175 // always seemed a valid generalization. (DLD -- 6/00)
3176 vtable()->verify(st);
3177 }
3179 // Verify first subklass
3180 if (subklass_oop() != NULL) {
3181 guarantee(subklass_oop()->is_klass(), "should be klass");
3182 }
3184 // Verify siblings
3185 Klass* super = this->super();
3186 Klass* sib = next_sibling();
3187 if (sib != NULL) {
3188 if (sib == this) {
3189 fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
3190 }
3192 guarantee(sib->is_klass(), "should be klass");
3193 guarantee(sib->super() == super, "siblings should have same superklass");
3194 }
3196 // Verify implementor fields
3197 Klass* im = implementor();
3198 if (im != NULL) {
3199 guarantee(is_interface(), "only interfaces should have implementor set");
3200 guarantee(im->is_klass(), "should be klass");
3201 guarantee(!im->is_interface() || im == this,
3202 "implementors cannot be interfaces");
3203 }
3205 // Verify local interfaces
3206 if (local_interfaces()) {
3207 Array<Klass*>* local_interfaces = this->local_interfaces();
3208 for (int j = 0; j < local_interfaces->length(); j++) {
3209 Klass* e = local_interfaces->at(j);
3210 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3211 }
3212 }
3214 // Verify transitive interfaces
3215 if (transitive_interfaces() != NULL) {
3216 Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3217 for (int j = 0; j < transitive_interfaces->length(); j++) {
3218 Klass* e = transitive_interfaces->at(j);
3219 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3220 }
3221 }
3223 // Verify methods
3224 if (methods() != NULL) {
3225 Array<Method*>* methods = this->methods();
3226 for (int j = 0; j < methods->length(); j++) {
3227 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3228 }
3229 for (int j = 0; j < methods->length() - 1; j++) {
3230 Method* m1 = methods->at(j);
3231 Method* m2 = methods->at(j + 1);
3232 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3233 }
3234 }
3236 // Verify method ordering
3237 if (method_ordering() != NULL) {
3238 Array<int>* method_ordering = this->method_ordering();
3239 int length = method_ordering->length();
3240 if (JvmtiExport::can_maintain_original_method_order() ||
3241 ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3242 guarantee(length == methods()->length(), "invalid method ordering length");
3243 jlong sum = 0;
3244 for (int j = 0; j < length; j++) {
3245 int original_index = method_ordering->at(j);
3246 guarantee(original_index >= 0, "invalid method ordering index");
3247 guarantee(original_index < length, "invalid method ordering index");
3248 sum += original_index;
3249 }
3250 // Verify sum of indices 0,1,...,length-1
3251 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3252 } else {
3253 guarantee(length == 0, "invalid method ordering length");
3254 }
3255 }
3257 // Verify default methods
3258 if (default_methods() != NULL) {
3259 Array<Method*>* methods = this->default_methods();
3260 for (int j = 0; j < methods->length(); j++) {
3261 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3262 }
3263 for (int j = 0; j < methods->length() - 1; j++) {
3264 Method* m1 = methods->at(j);
3265 Method* m2 = methods->at(j + 1);
3266 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3267 }
3268 }
3270 // Verify JNI static field identifiers
3271 if (jni_ids() != NULL) {
3272 jni_ids()->verify(this);
3273 }
3275 // Verify other fields
3276 if (array_klasses() != NULL) {
3277 guarantee(array_klasses()->is_klass(), "should be klass");
3278 }
3279 if (constants() != NULL) {
3280 guarantee(constants()->is_constantPool(), "should be constant pool");
3281 }
3282 const Klass* host = host_klass();
3283 if (host != NULL) {
3284 guarantee(host->is_klass(), "should be klass");
3285 }
3286 }
3288 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3289 Klass::oop_verify_on(obj, st);
3290 VerifyFieldClosure blk;
3291 obj->oop_iterate_no_header(&blk);
3292 }
3295 // JNIid class for jfieldIDs only
3296 // Note to reviewers:
3297 // These JNI functions are just moved over to column 1 and not changed
3298 // in the compressed oops workspace.
3299 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3300 _holder = holder;
3301 _offset = offset;
3302 _next = next;
3303 debug_only(_is_static_field_id = false;)
3304 }
3307 JNIid* JNIid::find(int offset) {
3308 JNIid* current = this;
3309 while (current != NULL) {
3310 if (current->offset() == offset) return current;
3311 current = current->next();
3312 }
3313 return NULL;
3314 }
3316 void JNIid::deallocate(JNIid* current) {
3317 while (current != NULL) {
3318 JNIid* next = current->next();
3319 delete current;
3320 current = next;
3321 }
3322 }
3325 void JNIid::verify(Klass* holder) {
3326 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3327 int end_field_offset;
3328 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3330 JNIid* current = this;
3331 while (current != NULL) {
3332 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3333 #ifdef ASSERT
3334 int o = current->offset();
3335 if (current->is_static_field_id()) {
3336 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3337 }
3338 #endif
3339 current = current->next();
3340 }
3341 }
3344 #ifdef ASSERT
3345 void InstanceKlass::set_init_state(ClassState state) {
3346 bool good_state = is_shared() ? (_init_state <= state)
3347 : (_init_state < state);
3348 assert(good_state || state == allocated, "illegal state transition");
3349 _init_state = (u1)state;
3350 }
3351 #endif
3354 // RedefineClasses() support for previous versions:
3356 // Purge previous versions
3357 static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
3358 if (ik->previous_versions() != NULL) {
3359 // This klass has previous versions so see what we can cleanup
3360 // while it is safe to do so.
3362 int deleted_count = 0; // leave debugging breadcrumbs
3363 int live_count = 0;
3364 ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
3365 ClassLoaderData::the_null_class_loader_data() :
3366 ik->class_loader_data();
3368 // RC_TRACE macro has an embedded ResourceMark
3369 RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
3370 ik->external_name(), ik->previous_versions()->length()));
3372 for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
3373 // check the previous versions array
3374 PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
3375 ConstantPool* cp_ref = pv_node->prev_constant_pool();
3376 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
3378 ConstantPool* pvcp = cp_ref;
3379 if (!pvcp->on_stack()) {
3380 // If the constant pool isn't on stack, none of the methods
3381 // are executing. Delete all the methods, the constant pool and
3382 // and this previous version node.
3383 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3384 if (method_refs != NULL) {
3385 for (int j = method_refs->length() - 1; j >= 0; j--) {
3386 Method* method = method_refs->at(j);
3387 assert(method != NULL, "method ref was unexpectedly cleared");
3388 method_refs->remove_at(j);
3389 // method will be freed with associated class.
3390 }
3391 }
3392 // Remove the constant pool
3393 delete pv_node;
3394 // Since we are traversing the array backwards, we don't have to
3395 // do anything special with the index.
3396 ik->previous_versions()->remove_at(i);
3397 deleted_count++;
3398 continue;
3399 } else {
3400 RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
3401 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3402 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3403 live_count++;
3404 }
3406 // At least one method is live in this previous version, clean out
3407 // the others or mark them as obsolete.
3408 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3409 if (method_refs != NULL) {
3410 RC_TRACE(0x00000200, ("purge: previous methods length=%d",
3411 method_refs->length()));
3412 for (int j = method_refs->length() - 1; j >= 0; j--) {
3413 Method* method = method_refs->at(j);
3414 assert(method != NULL, "method ref was unexpectedly cleared");
3416 // Remove the emcp method if it's not executing
3417 // If it's been made obsolete by a redefinition of a non-emcp
3418 // method, mark it as obsolete but leave it to clean up later.
3419 if (!method->on_stack()) {
3420 method_refs->remove_at(j);
3421 } else if (emcp_method_count == 0) {
3422 method->set_is_obsolete();
3423 } else {
3424 // RC_TRACE macro has an embedded ResourceMark
3425 RC_TRACE(0x00000200,
3426 ("purge: %s(%s): prev method @%d in version @%d is alive",
3427 method->name()->as_C_string(),
3428 method->signature()->as_C_string(), j, i));
3429 }
3430 }
3431 }
3432 }
3433 assert(ik->previous_versions()->length() == live_count, "sanity check");
3434 RC_TRACE(0x00000200,
3435 ("purge: previous version stats: live=%d, deleted=%d", live_count,
3436 deleted_count));
3437 }
3438 }
3440 // External interface for use during class unloading.
3441 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
3442 // Call with >0 emcp methods since they are not currently being redefined.
3443 purge_previous_versions_internal(ik, 1);
3444 }
3447 // Potentially add an information node that contains pointers to the
3448 // interesting parts of the previous version of the_class.
3449 // This is also where we clean out any unused references.
3450 // Note that while we delete nodes from the _previous_versions
3451 // array, we never delete the array itself until the klass is
3452 // unloaded. The has_been_redefined() query depends on that fact.
3453 //
3454 void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
3455 BitMap* emcp_methods, int emcp_method_count) {
3456 assert(Thread::current()->is_VM_thread(),
3457 "only VMThread can add previous versions");
3459 if (_previous_versions == NULL) {
3460 // This is the first previous version so make some space.
3461 // Start with 2 elements under the assumption that the class
3462 // won't be redefined much.
3463 _previous_versions = new (ResourceObj::C_HEAP, mtClass)
3464 GrowableArray<PreviousVersionNode *>(2, true);
3465 }
3467 ConstantPool* cp_ref = ikh->constants();
3469 // RC_TRACE macro has an embedded ResourceMark
3470 RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
3471 "on_stack=%d",
3472 ikh->external_name(), _previous_versions->length(), emcp_method_count,
3473 cp_ref->on_stack()));
3475 // If the constant pool for this previous version of the class
3476 // is not marked as being on the stack, then none of the methods
3477 // in this previous version of the class are on the stack so
3478 // we don't need to create a new PreviousVersionNode. However,
3479 // we still need to examine older previous versions below.
3480 Array<Method*>* old_methods = ikh->methods();
3482 if (cp_ref->on_stack()) {
3483 PreviousVersionNode * pv_node = NULL;
3484 if (emcp_method_count == 0) {
3485 // non-shared ConstantPool gets a reference
3486 pv_node = new PreviousVersionNode(cp_ref, NULL);
3487 RC_TRACE(0x00000400,
3488 ("add: all methods are obsolete; flushing any EMCP refs"));
3489 } else {
3490 int local_count = 0;
3491 GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
3492 GrowableArray<Method*>(emcp_method_count, true);
3493 for (int i = 0; i < old_methods->length(); i++) {
3494 if (emcp_methods->at(i)) {
3495 // this old method is EMCP. Save it only if it's on the stack
3496 Method* old_method = old_methods->at(i);
3497 if (old_method->on_stack()) {
3498 method_refs->append(old_method);
3499 }
3500 if (++local_count >= emcp_method_count) {
3501 // no more EMCP methods so bail out now
3502 break;
3503 }
3504 }
3505 }
3506 // non-shared ConstantPool gets a reference
3507 pv_node = new PreviousVersionNode(cp_ref, method_refs);
3508 }
3509 // append new previous version.
3510 _previous_versions->append(pv_node);
3511 }
3513 // Since the caller is the VMThread and we are at a safepoint, this
3514 // is a good time to clear out unused references.
3516 RC_TRACE(0x00000400, ("add: previous version length=%d",
3517 _previous_versions->length()));
3519 // Purge previous versions not executing on the stack
3520 purge_previous_versions_internal(this, emcp_method_count);
3522 int obsolete_method_count = old_methods->length() - emcp_method_count;
3524 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3525 _previous_versions->length() > 0) {
3526 // We have a mix of obsolete and EMCP methods so we have to
3527 // clear out any matching EMCP method entries the hard way.
3528 int local_count = 0;
3529 for (int i = 0; i < old_methods->length(); i++) {
3530 if (!emcp_methods->at(i)) {
3531 // only obsolete methods are interesting
3532 Method* old_method = old_methods->at(i);
3533 Symbol* m_name = old_method->name();
3534 Symbol* m_signature = old_method->signature();
3536 // we might not have added the last entry
3537 for (int j = _previous_versions->length() - 1; j >= 0; j--) {
3538 // check the previous versions array for non executing obsolete methods
3539 PreviousVersionNode * pv_node = _previous_versions->at(j);
3541 GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3542 if (method_refs == NULL) {
3543 // We have run into a PreviousVersion generation where
3544 // all methods were made obsolete during that generation's
3545 // RedefineClasses() operation. At the time of that
3546 // operation, all EMCP methods were flushed so we don't
3547 // have to go back any further.
3548 //
3549 // A NULL method_refs is different than an empty method_refs.
3550 // We cannot infer any optimizations about older generations
3551 // from an empty method_refs for the current generation.
3552 break;
3553 }
3555 for (int k = method_refs->length() - 1; k >= 0; k--) {
3556 Method* method = method_refs->at(k);
3558 if (!method->is_obsolete() &&
3559 method->name() == m_name &&
3560 method->signature() == m_signature) {
3561 // The current RedefineClasses() call has made all EMCP
3562 // versions of this method obsolete so mark it as obsolete
3563 // and remove the reference.
3564 RC_TRACE(0x00000400,
3565 ("add: %s(%s): flush obsolete method @%d in version @%d",
3566 m_name->as_C_string(), m_signature->as_C_string(), k, j));
3568 method->set_is_obsolete();
3569 // Leave obsolete methods on the previous version list to
3570 // clean up later.
3571 break;
3572 }
3573 }
3575 // The previous loop may not find a matching EMCP method, but
3576 // that doesn't mean that we can optimize and not go any
3577 // further back in the PreviousVersion generations. The EMCP
3578 // method for this generation could have already been deleted,
3579 // but there still may be an older EMCP method that has not
3580 // been deleted.
3581 }
3583 if (++local_count >= obsolete_method_count) {
3584 // no more obsolete methods so bail out now
3585 break;
3586 }
3587 }
3588 }
3589 }
3590 } // end add_previous_version()
3593 // Determine if InstanceKlass has a previous version.
3594 bool InstanceKlass::has_previous_version() const {
3595 return (_previous_versions != NULL && _previous_versions->length() > 0);
3596 } // end has_previous_version()
3599 Method* InstanceKlass::method_with_idnum(int idnum) {
3600 Method* m = NULL;
3601 if (idnum < methods()->length()) {
3602 m = methods()->at(idnum);
3603 }
3604 if (m == NULL || m->method_idnum() != idnum) {
3605 for (int index = 0; index < methods()->length(); ++index) {
3606 m = methods()->at(index);
3607 if (m->method_idnum() == idnum) {
3608 return m;
3609 }
3610 }
3611 // None found, return null for the caller to handle.
3612 return NULL;
3613 }
3614 return m;
3615 }
3617 jint InstanceKlass::get_cached_class_file_len() {
3618 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3619 }
3621 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3622 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3623 }
3626 // Construct a PreviousVersionNode entry for the array hung off
3627 // the InstanceKlass.
3628 PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
3629 GrowableArray<Method*>* prev_EMCP_methods) {
3631 _prev_constant_pool = prev_constant_pool;
3632 _prev_EMCP_methods = prev_EMCP_methods;
3633 }
3636 // Destroy a PreviousVersionNode
3637 PreviousVersionNode::~PreviousVersionNode() {
3638 if (_prev_constant_pool != NULL) {
3639 _prev_constant_pool = NULL;
3640 }
3642 if (_prev_EMCP_methods != NULL) {
3643 delete _prev_EMCP_methods;
3644 }
3645 }
3647 // Construct a helper for walking the previous versions array
3648 PreviousVersionWalker::PreviousVersionWalker(Thread* thread, InstanceKlass *ik) {
3649 _thread = thread;
3650 _previous_versions = ik->previous_versions();
3651 _current_index = 0;
3652 _current_p = NULL;
3653 _current_constant_pool_handle = constantPoolHandle(thread, ik->constants());
3654 }
3657 // Return the interesting information for the next previous version
3658 // of the klass. Returns NULL if there are no more previous versions.
3659 PreviousVersionNode* PreviousVersionWalker::next_previous_version() {
3660 if (_previous_versions == NULL) {
3661 // no previous versions so nothing to return
3662 return NULL;
3663 }
3665 _current_p = NULL; // reset to NULL
3666 _current_constant_pool_handle = NULL;
3668 int length = _previous_versions->length();
3670 while (_current_index < length) {
3671 PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
3673 // Save a handle to the constant pool for this previous version,
3674 // which keeps all the methods from being deallocated.
3675 _current_constant_pool_handle = constantPoolHandle(_thread, pv_node->prev_constant_pool());
3676 _current_p = pv_node;
3677 return pv_node;
3678 }
3680 return NULL;
3681 } // end next_previous_version()