1 /*
2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "aot/aotLoader.hpp"
27 #include "classfile/classFileParser.hpp"
28 #include "classfile/classFileStream.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "classfile/javaClasses.hpp"
31 #include "classfile/moduleEntry.hpp"
32 #include "classfile/systemDictionary.hpp"
33 #include "classfile/systemDictionaryShared.hpp"
34 #include "classfile/verifier.hpp"
35 #include "classfile/vmSymbols.hpp"
36 #include "code/dependencyContext.hpp"
37 #include "compiler/compileBroker.hpp"
38 #include "gc/shared/collectedHeap.inline.hpp"
39 #include "gc/shared/specialized_oop_closures.hpp"
40 #include "interpreter/oopMapCache.hpp"
41 #include "interpreter/rewriter.hpp"
42 #include "jvmtifiles/jvmti.h"
43 #include "logging/log.hpp"
44 #include "memory/heapInspection.hpp"
45 #include "memory/iterator.inline.hpp"
46 #include "memory/metadataFactory.hpp"
47 #include "memory/metaspaceShared.hpp"
48 #include "memory/oopFactory.hpp"
49 #include "memory/resourceArea.hpp"
50 #include "oops/fieldStreams.hpp"
51 #include "oops/instanceClassLoaderKlass.hpp"
52 #include "oops/instanceKlass.inline.hpp"
53 #include "oops/instanceMirrorKlass.hpp"
54 #include "oops/instanceOop.hpp"
55 #include "oops/klass.inline.hpp"
56 #include "oops/method.hpp"
57 #include "oops/oop.inline.hpp"
58 #include "oops/symbol.hpp"
59 #include "prims/jvmtiExport.hpp"
60 #include "prims/jvmtiRedefineClasses.hpp"
61 #include "prims/jvmtiThreadState.hpp"
62 #include "prims/methodComparator.hpp"
63 #include "runtime/atomic.hpp"
64 #include "runtime/fieldDescriptor.hpp"
65 #include "runtime/handles.inline.hpp"
66 #include "runtime/javaCalls.hpp"
67 #include "runtime/mutexLocker.hpp"
68 #include "runtime/orderAccess.inline.hpp"
69 #include "runtime/thread.inline.hpp"
70 #include "services/classLoadingService.hpp"
71 #include "services/threadService.hpp"
72 #include "utilities/dtrace.hpp"
73 #include "utilities/macros.hpp"
74 #include "utilities/stringUtils.hpp"
75 #include "logging/log.hpp"
76 #ifdef COMPILER1
77 #include "c1/c1_Compiler.hpp"
78 #endif
79
80 #ifdef DTRACE_ENABLED
81
82
83 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
84 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
85 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
86 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
87 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
88 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
89 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
90 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
91 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
92 { \
93 char* data = NULL; \
94 int len = 0; \
95 Symbol* name = (clss)->name(); \
96 if (name != NULL) { \
97 data = (char*)name->bytes(); \
98 len = name->utf8_length(); \
99 } \
100 HOTSPOT_CLASS_INITIALIZATION_##type( \
101 data, len, (clss)->class_loader(), thread_type); \
102 }
103
104 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
105 { \
106 char* data = NULL; \
107 int len = 0; \
108 Symbol* name = (clss)->name(); \
109 if (name != NULL) { \
110 data = (char*)name->bytes(); \
111 len = name->utf8_length(); \
112 } \
113 HOTSPOT_CLASS_INITIALIZATION_##type( \
114 data, len, (clss)->class_loader(), thread_type, wait); \
115 }
116
117 #else // ndef DTRACE_ENABLED
118
119 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
120 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
121
122 #endif // ndef DTRACE_ENABLED
123
124 volatile int InstanceKlass::_total_instanceKlass_count = 0;
125
126 static inline bool is_class_loader(const Symbol* class_name,
127 const ClassFileParser& parser) {
128 assert(class_name != NULL, "invariant");
129
130 if (class_name == vmSymbols::java_lang_ClassLoader()) {
131 return true;
132 }
133
134 if (SystemDictionary::ClassLoader_klass_loaded()) {
135 const Klass* const super_klass = parser.super_klass();
136 if (super_klass != NULL) {
137 if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
138 return true;
139 }
140 }
141 }
142 return false;
143 }
144
145 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
146 const int size = InstanceKlass::size(parser.vtable_size(),
147 parser.itable_size(),
148 nonstatic_oop_map_size(parser.total_oop_map_count()),
149 parser.is_interface(),
150 parser.is_anonymous(),
151 should_store_fingerprint());
152
153 const Symbol* const class_name = parser.class_name();
154 assert(class_name != NULL, "invariant");
155 ClassLoaderData* loader_data = parser.loader_data();
156 assert(loader_data != NULL, "invariant");
157
158 InstanceKlass* ik;
159
160 // Allocation
161 if (REF_NONE == parser.reference_type()) {
162 if (class_name == vmSymbols::java_lang_Class()) {
163 // mirror
164 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
165 }
166 else if (is_class_loader(class_name, parser)) {
167 // class loader
168 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
169 }
170 else {
171 // normal
172 ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
173 }
174 }
175 else {
176 // reference
177 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
178 }
179
180 // Check for pending exception before adding to the loader data and incrementing
181 // class count. Can get OOM here.
182 if (HAS_PENDING_EXCEPTION) {
183 return NULL;
184 }
185
186 assert(ik != NULL, "invariant");
187
188 const bool publicize = !parser.is_internal();
189
190 // Add all classes to our internal class loader list here,
191 // including classes in the bootstrap (NULL) class loader.
192 loader_data->add_class(ik, publicize);
193 Atomic::inc(&_total_instanceKlass_count);
194
195 return ik;
196 }
197
198
199 // copy method ordering from resource area to Metaspace
200 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
201 if (m != NULL) {
202 // allocate a new array and copy contents (memcpy?)
203 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
204 for (int i = 0; i < m->length(); i++) {
205 _method_ordering->at_put(i, m->at(i));
206 }
207 } else {
208 _method_ordering = Universe::the_empty_int_array();
209 }
210 }
211
212 // create a new array of vtable_indices for default methods
213 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
214 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
215 assert(default_vtable_indices() == NULL, "only create once");
216 set_default_vtable_indices(vtable_indices);
217 return vtable_indices;
218 }
219
220 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind) :
221 _static_field_size(parser.static_field_size()),
222 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
223 _itable_len(parser.itable_size()),
224 _reference_type(parser.reference_type()) {
225 set_vtable_length(parser.vtable_size());
226 set_kind(kind);
227 set_access_flags(parser.access_flags());
228 set_is_anonymous(parser.is_anonymous());
229 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
230 false));
231
232 assert(NULL == _methods, "underlying memory not zeroed?");
233 assert(is_instance_klass(), "is layout incorrect?");
234 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
235 }
236
237 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
238 Array<Method*>* methods) {
239 if (methods != NULL && methods != Universe::the_empty_method_array() &&
240 !methods->is_shared()) {
241 for (int i = 0; i < methods->length(); i++) {
242 Method* method = methods->at(i);
243 if (method == NULL) continue; // maybe null if error processing
244 // Only want to delete methods that are not executing for RedefineClasses.
245 // The previous version will point to them so they're not totally dangling
246 assert (!method->on_stack(), "shouldn't be called with methods on stack");
247 MetadataFactory::free_metadata(loader_data, method);
248 }
249 MetadataFactory::free_array<Method*>(loader_data, methods);
250 }
251 }
252
253 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
254 const Klass* super_klass,
255 Array<Klass*>* local_interfaces,
256 Array<Klass*>* transitive_interfaces) {
257 // Only deallocate transitive interfaces if not empty, same as super class
258 // or same as local interfaces. See code in parseClassFile.
259 Array<Klass*>* ti = transitive_interfaces;
260 if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
261 // check that the interfaces don't come from super class
262 Array<Klass*>* sti = (super_klass == NULL) ? NULL :
263 InstanceKlass::cast(super_klass)->transitive_interfaces();
264 if (ti != sti && ti != NULL && !ti->is_shared()) {
265 MetadataFactory::free_array<Klass*>(loader_data, ti);
266 }
267 }
268
269 // local interfaces can be empty
270 if (local_interfaces != Universe::the_empty_klass_array() &&
271 local_interfaces != NULL && !local_interfaces->is_shared()) {
272 MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
273 }
274 }
275
276 // This function deallocates the metadata and C heap pointers that the
277 // InstanceKlass points to.
278 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
279
280 // Orphan the mirror first, CMS thinks it's still live.
281 if (java_mirror() != NULL) {
282 java_lang_Class::set_klass(java_mirror(), NULL);
283 }
284
285 // Need to take this class off the class loader data list.
286 loader_data->remove_class(this);
287
288 // The array_klass for this class is created later, after error handling.
289 // For class redefinition, we keep the original class so this scratch class
290 // doesn't have an array class. Either way, assert that there is nothing
291 // to deallocate.
292 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
293
294 // Release C heap allocated data that this might point to, which includes
295 // reference counting symbol names.
296 release_C_heap_structures();
297
298 deallocate_methods(loader_data, methods());
299 set_methods(NULL);
300
301 if (method_ordering() != NULL &&
302 method_ordering() != Universe::the_empty_int_array() &&
303 !method_ordering()->is_shared()) {
304 MetadataFactory::free_array<int>(loader_data, method_ordering());
305 }
306 set_method_ordering(NULL);
307
308 // default methods can be empty
309 if (default_methods() != NULL &&
310 default_methods() != Universe::the_empty_method_array() &&
311 !default_methods()->is_shared()) {
312 MetadataFactory::free_array<Method*>(loader_data, default_methods());
313 }
314 // Do NOT deallocate the default methods, they are owned by superinterfaces.
315 set_default_methods(NULL);
316
317 // default methods vtable indices can be empty
318 if (default_vtable_indices() != NULL &&
319 !default_vtable_indices()->is_shared()) {
320 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
321 }
322 set_default_vtable_indices(NULL);
323
324
325 // This array is in Klass, but remove it with the InstanceKlass since
326 // this place would be the only caller and it can share memory with transitive
327 // interfaces.
328 if (secondary_supers() != NULL &&
329 secondary_supers() != Universe::the_empty_klass_array() &&
330 secondary_supers() != transitive_interfaces() &&
331 !secondary_supers()->is_shared()) {
332 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
333 }
334 set_secondary_supers(NULL);
335
336 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
337 set_transitive_interfaces(NULL);
338 set_local_interfaces(NULL);
339
340 if (fields() != NULL && !fields()->is_shared()) {
341 MetadataFactory::free_array<jushort>(loader_data, fields());
342 }
343 set_fields(NULL, 0);
344
345 // If a method from a redefined class is using this constant pool, don't
346 // delete it, yet. The new class's previous version will point to this.
347 if (constants() != NULL) {
348 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
349 if (!constants()->is_shared()) {
350 MetadataFactory::free_metadata(loader_data, constants());
351 }
352 // Delete any cached resolution errors for the constant pool
353 SystemDictionary::delete_resolution_error(constants());
354
355 set_constants(NULL);
356 }
357
358 if (inner_classes() != NULL &&
359 inner_classes() != Universe::the_empty_short_array() &&
360 !inner_classes()->is_shared()) {
361 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
362 }
363 set_inner_classes(NULL);
364
365 // We should deallocate the Annotations instance if it's not in shared spaces.
366 if (annotations() != NULL && !annotations()->is_shared()) {
367 MetadataFactory::free_metadata(loader_data, annotations());
368 }
369 set_annotations(NULL);
370 }
371
372 bool InstanceKlass::should_be_initialized() const {
373 return !is_initialized();
374 }
375
376 klassItable* InstanceKlass::itable() const {
377 return new klassItable(instanceKlassHandle(this));
378 }
379
380 void InstanceKlass::eager_initialize(Thread *thread) {
381 if (!EagerInitialization) return;
382
383 if (this->is_not_initialized()) {
384 // abort if the the class has a class initializer
385 if (this->class_initializer() != NULL) return;
386
387 // abort if it is java.lang.Object (initialization is handled in genesis)
388 Klass* super = this->super();
389 if (super == NULL) return;
390
391 // abort if the super class should be initialized
392 if (!InstanceKlass::cast(super)->is_initialized()) return;
393
394 // call body to expose the this pointer
395 instanceKlassHandle this_k(thread, this);
396 eager_initialize_impl(this_k);
397 }
398 }
399
400 // JVMTI spec thinks there are signers and protection domain in the
401 // instanceKlass. These accessors pretend these fields are there.
402 // The hprof specification also thinks these fields are in InstanceKlass.
403 oop InstanceKlass::protection_domain() const {
404 // return the protection_domain from the mirror
405 return java_lang_Class::protection_domain(java_mirror());
406 }
407
408 // To remove these from requires an incompatible change and CCC request.
409 objArrayOop InstanceKlass::signers() const {
410 // return the signers from the mirror
411 return java_lang_Class::signers(java_mirror());
412 }
413
414 oop InstanceKlass::init_lock() const {
415 // return the init lock from the mirror
416 oop lock = java_lang_Class::init_lock(java_mirror());
417 // Prevent reordering with any access of initialization state
418 OrderAccess::loadload();
419 assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
420 "only fully initialized state can have a null lock");
421 return lock;
422 }
423
424 // Set the initialization lock to null so the object can be GC'ed. Any racing
425 // threads to get this lock will see a null lock and will not lock.
426 // That's okay because they all check for initialized state after getting
427 // the lock and return.
428 void InstanceKlass::fence_and_clear_init_lock() {
429 // make sure previous stores are all done, notably the init_state.
430 OrderAccess::storestore();
431 java_lang_Class::set_init_lock(java_mirror(), NULL);
432 assert(!is_not_initialized(), "class must be initialized now");
433 }
434
435 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_k) {
436 EXCEPTION_MARK;
437 oop init_lock = this_k->init_lock();
438 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
439
440 // abort if someone beat us to the initialization
441 if (!this_k->is_not_initialized()) return; // note: not equivalent to is_initialized()
442
443 ClassState old_state = this_k->init_state();
444 link_class_impl(this_k, true, THREAD);
445 if (HAS_PENDING_EXCEPTION) {
446 CLEAR_PENDING_EXCEPTION;
447 // Abort if linking the class throws an exception.
448
449 // Use a test to avoid redundantly resetting the state if there's
450 // no change. Set_init_state() asserts that state changes make
451 // progress, whereas here we might just be spinning in place.
452 if( old_state != this_k->_init_state )
453 this_k->set_init_state (old_state);
454 } else {
455 // linking successfull, mark class as initialized
456 this_k->set_init_state (fully_initialized);
457 this_k->fence_and_clear_init_lock();
458 // trace
459 if (log_is_enabled(Info, class, init)) {
460 ResourceMark rm(THREAD);
461 log_info(class, init)("[Initialized %s without side effects]", this_k->external_name());
462 }
463 }
464 }
465
466
467 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
468 // process. The step comments refers to the procedure described in that section.
469 // Note: implementation moved to static method to expose the this pointer.
470 void InstanceKlass::initialize(TRAPS) {
471 if (this->should_be_initialized()) {
472 HandleMark hm(THREAD);
473 instanceKlassHandle this_k(THREAD, this);
474 initialize_impl(this_k, CHECK);
475 // Note: at this point the class may be initialized
476 // OR it may be in the state of being initialized
477 // in case of recursive initialization!
478 } else {
479 assert(is_initialized(), "sanity check");
480 }
481 }
482
483
484 bool InstanceKlass::verify_code(
485 instanceKlassHandle this_k, bool throw_verifyerror, TRAPS) {
486 // 1) Verify the bytecodes
487 Verifier::Mode mode =
488 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
489 return Verifier::verify(this_k, mode, this_k->should_verify_class(), THREAD);
490 }
491
492
493 // Used exclusively by the shared spaces dump mechanism to prevent
494 // classes mapped into the shared regions in new VMs from appearing linked.
495
496 void InstanceKlass::unlink_class() {
497 assert(is_linked(), "must be linked");
498 _init_state = loaded;
499 }
500
501 void InstanceKlass::link_class(TRAPS) {
502 assert(is_loaded(), "must be loaded");
503 if (!is_linked()) {
504 HandleMark hm(THREAD);
505 instanceKlassHandle this_k(THREAD, this);
506 link_class_impl(this_k, true, CHECK);
507 }
508 }
509
510 // Called to verify that a class can link during initialization, without
511 // throwing a VerifyError.
512 bool InstanceKlass::link_class_or_fail(TRAPS) {
513 assert(is_loaded(), "must be loaded");
514 if (!is_linked()) {
515 HandleMark hm(THREAD);
516 instanceKlassHandle this_k(THREAD, this);
517 link_class_impl(this_k, false, CHECK_false);
518 }
519 return is_linked();
520 }
521
522 bool InstanceKlass::link_class_impl(
523 instanceKlassHandle this_k, bool throw_verifyerror, TRAPS) {
524 if (DumpSharedSpaces && this_k->is_in_error_state()) {
525 // This is for CDS dumping phase only -- we use the in_error_state to indicate that
526 // the class has failed verification. Throwing the NoClassDefFoundError here is just
527 // a convenient way to stop repeat attempts to verify the same (bad) class.
528 //
529 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
530 // if we are executing Java code. This is not a problem for CDS dumping phase since
531 // it doesn't execute any Java code.
532 ResourceMark rm(THREAD);
533 THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
534 this_k->external_name(), false);
535 }
536 // return if already verified
537 if (this_k->is_linked()) {
538 return true;
539 }
540
541 // Timing
542 // timer handles recursion
543 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
544 JavaThread* jt = (JavaThread*)THREAD;
545
546 // link super class before linking this class
547 instanceKlassHandle super(THREAD, this_k->super());
548 if (super.not_null()) {
549 if (super->is_interface()) { // check if super class is an interface
550 ResourceMark rm(THREAD);
551 Exceptions::fthrow(
552 THREAD_AND_LOCATION,
553 vmSymbols::java_lang_IncompatibleClassChangeError(),
554 "class %s has interface %s as super class",
555 this_k->external_name(),
556 super->external_name()
557 );
558 return false;
559 }
560
561 link_class_impl(super, throw_verifyerror, CHECK_false);
562 }
563
564 // link all interfaces implemented by this class before linking this class
565 Array<Klass*>* interfaces = this_k->local_interfaces();
566 int num_interfaces = interfaces->length();
567 for (int index = 0; index < num_interfaces; index++) {
568 HandleMark hm(THREAD);
569 instanceKlassHandle ih(THREAD, interfaces->at(index));
570 link_class_impl(ih, throw_verifyerror, CHECK_false);
571 }
572
573 // in case the class is linked in the process of linking its superclasses
574 if (this_k->is_linked()) {
575 return true;
576 }
577
578 // trace only the link time for this klass that includes
579 // the verification time
580 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
581 ClassLoader::perf_class_link_selftime(),
582 ClassLoader::perf_classes_linked(),
583 jt->get_thread_stat()->perf_recursion_counts_addr(),
584 jt->get_thread_stat()->perf_timers_addr(),
585 PerfClassTraceTime::CLASS_LINK);
586
587 // verification & rewriting
588 {
589 oop init_lock = this_k->init_lock();
590 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
591 // rewritten will have been set if loader constraint error found
592 // on an earlier link attempt
593 // don't verify or rewrite if already rewritten
594
595 if (!this_k->is_linked()) {
596 if (!this_k->is_rewritten()) {
597 {
598 bool verify_ok = verify_code(this_k, throw_verifyerror, THREAD);
599 if (!verify_ok) {
600 return false;
601 }
602 }
603
604 // Just in case a side-effect of verify linked this class already
605 // (which can sometimes happen since the verifier loads classes
606 // using custom class loaders, which are free to initialize things)
607 if (this_k->is_linked()) {
608 return true;
609 }
610
611 // also sets rewritten
612 this_k->rewrite_class(CHECK_false);
613 } else if (this_k->is_shared()) {
614 SystemDictionaryShared::check_verification_constraints(this_k, CHECK_false);
615 }
616
617 // relocate jsrs and link methods after they are all rewritten
618 this_k->link_methods(CHECK_false);
619
620 // Initialize the vtable and interface table after
621 // methods have been rewritten since rewrite may
622 // fabricate new Method*s.
623 // also does loader constraint checking
624 //
625 // initialize_vtable and initialize_itable need to be rerun for
626 // a shared class if the class is not loaded by the NULL classloader.
627 ClassLoaderData * loader_data = this_k->class_loader_data();
628 if (!(this_k->is_shared() &&
629 loader_data->is_the_null_class_loader_data())) {
630 ResourceMark rm(THREAD);
631 this_k->vtable()->initialize_vtable(true, CHECK_false);
632 this_k->itable()->initialize_itable(true, CHECK_false);
633 }
634 #ifdef ASSERT
635 else {
636 ResourceMark rm(THREAD);
637 this_k->vtable()->verify(tty, true);
638 // In case itable verification is ever added.
639 // this_k->itable()->verify(tty, true);
640 }
641 #endif
642 this_k->set_init_state(linked);
643 if (JvmtiExport::should_post_class_prepare()) {
644 Thread *thread = THREAD;
645 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
646 JvmtiExport::post_class_prepare((JavaThread *) thread, this_k());
647 }
648 }
649 }
650 return true;
651 }
652
653
654 // Rewrite the byte codes of all of the methods of a class.
655 // The rewriter must be called exactly once. Rewriting must happen after
656 // verification but before the first method of the class is executed.
657 void InstanceKlass::rewrite_class(TRAPS) {
658 assert(is_loaded(), "must be loaded");
659 instanceKlassHandle this_k(THREAD, this);
660 if (this_k->is_rewritten()) {
661 assert(this_k()->is_shared(), "rewriting an unshared class?");
662 return;
663 }
664 Rewriter::rewrite(this_k, CHECK);
665 this_k->set_rewritten();
666 }
667
668 // Now relocate and link method entry points after class is rewritten.
669 // This is outside is_rewritten flag. In case of an exception, it can be
670 // executed more than once.
671 void InstanceKlass::link_methods(TRAPS) {
672 int len = methods()->length();
673 for (int i = len-1; i >= 0; i--) {
674 methodHandle m(THREAD, methods()->at(i));
675
676 // Set up method entry points for compiler and interpreter .
677 m->link_method(m, CHECK);
678 }
679 }
680
681 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
682 void InstanceKlass::initialize_super_interfaces(instanceKlassHandle this_k, TRAPS) {
683 assert (this_k->has_nonstatic_concrete_methods(), "caller should have checked this");
684 for (int i = 0; i < this_k->local_interfaces()->length(); ++i) {
685 Klass* iface = this_k->local_interfaces()->at(i);
686 InstanceKlass* ik = InstanceKlass::cast(iface);
687
688 // Initialization is depth first search ie. we start with top of the inheritance tree
689 // has_nonstatic_concrete_methods drives searching superinterfaces since it
690 // means has_nonstatic_concrete_methods in its superinterface hierarchy
691 if (ik->has_nonstatic_concrete_methods()) {
692 ik->initialize_super_interfaces(ik, CHECK);
693 }
694
695 // Only initialize() interfaces that "declare" concrete methods.
696 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
697 ik->initialize(CHECK);
698 }
699 }
700 }
701
702 void InstanceKlass::initialize_impl(instanceKlassHandle this_k, TRAPS) {
703 // Make sure klass is linked (verified) before initialization
704 // A class could already be verified, since it has been reflected upon.
705 this_k->link_class(CHECK);
706
707 DTRACE_CLASSINIT_PROBE(required, this_k(), -1);
708
709 bool wait = false;
710
711 // refer to the JVM book page 47 for description of steps
712 // Step 1
713 {
714 oop init_lock = this_k->init_lock();
715 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
716
717 Thread *self = THREAD; // it's passed the current thread
718
719 // Step 2
720 // If we were to use wait() instead of waitInterruptibly() then
721 // we might end up throwing IE from link/symbol resolution sites
722 // that aren't expected to throw. This would wreak havoc. See 6320309.
723 while(this_k->is_being_initialized() && !this_k->is_reentrant_initialization(self)) {
724 wait = true;
725 ol.waitUninterruptibly(CHECK);
726 }
727
728 // Step 3
729 if (this_k->is_being_initialized() && this_k->is_reentrant_initialization(self)) {
730 DTRACE_CLASSINIT_PROBE_WAIT(recursive, this_k(), -1,wait);
731 return;
732 }
733
734 // Step 4
735 if (this_k->is_initialized()) {
736 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, this_k(), -1,wait);
737 return;
738 }
739
740 // Step 5
741 if (this_k->is_in_error_state()) {
742 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, this_k(), -1,wait);
743 ResourceMark rm(THREAD);
744 const char* desc = "Could not initialize class ";
745 const char* className = this_k->external_name();
746 size_t msglen = strlen(desc) + strlen(className) + 1;
747 char* message = NEW_RESOURCE_ARRAY(char, msglen);
748 if (NULL == message) {
749 // Out of memory: can't create detailed error message
750 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
751 } else {
752 jio_snprintf(message, msglen, "%s%s", desc, className);
753 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
754 }
755 }
756
757 // Step 6
758 this_k->set_init_state(being_initialized);
759 this_k->set_init_thread(self);
760 }
761
762 // Step 7
763 // Next, if C is a class rather than an interface, initialize it's super class and super
764 // interfaces.
765 if (!this_k->is_interface()) {
766 Klass* super_klass = this_k->super();
767 if (super_klass != NULL && super_klass->should_be_initialized()) {
768 super_klass->initialize(THREAD);
769 }
770 // If C implements any interface that declares a non-static, concrete method,
771 // the initialization of C triggers initialization of its super interfaces.
772 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
773 // having a superinterface that declares, non-static, concrete methods
774 if (!HAS_PENDING_EXCEPTION && this_k->has_nonstatic_concrete_methods()) {
775 this_k->initialize_super_interfaces(this_k, THREAD);
776 }
777
778 // If any exceptions, complete abruptly, throwing the same exception as above.
779 if (HAS_PENDING_EXCEPTION) {
780 Handle e(THREAD, PENDING_EXCEPTION);
781 CLEAR_PENDING_EXCEPTION;
782 {
783 EXCEPTION_MARK;
784 // Locks object, set state, and notify all waiting threads
785 this_k->set_initialization_state_and_notify(initialization_error, THREAD);
786 CLEAR_PENDING_EXCEPTION;
787 }
788 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, this_k(), -1,wait);
789 THROW_OOP(e());
790 }
791 }
792
793
794 // Look for aot compiled methods for this klass, including class initializer.
795 AOTLoader::load_for_klass(this_k, THREAD);
796
797 // Step 8
798 {
799 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
800 JavaThread* jt = (JavaThread*)THREAD;
801 DTRACE_CLASSINIT_PROBE_WAIT(clinit, this_k(), -1,wait);
802 // Timer includes any side effects of class initialization (resolution,
803 // etc), but not recursive entry into call_class_initializer().
804 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
805 ClassLoader::perf_class_init_selftime(),
806 ClassLoader::perf_classes_inited(),
807 jt->get_thread_stat()->perf_recursion_counts_addr(),
808 jt->get_thread_stat()->perf_timers_addr(),
809 PerfClassTraceTime::CLASS_CLINIT);
810 this_k->call_class_initializer(THREAD);
811 }
812
813 // Step 9
814 if (!HAS_PENDING_EXCEPTION) {
815 this_k->set_initialization_state_and_notify(fully_initialized, CHECK);
816 { ResourceMark rm(THREAD);
817 debug_only(this_k->vtable()->verify(tty, true);)
818 }
819 }
820 else {
821 // Step 10 and 11
822 Handle e(THREAD, PENDING_EXCEPTION);
823 CLEAR_PENDING_EXCEPTION;
824 // JVMTI has already reported the pending exception
825 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
826 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
827 {
828 EXCEPTION_MARK;
829 this_k->set_initialization_state_and_notify(initialization_error, THREAD);
830 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
831 // JVMTI has already reported the pending exception
832 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
833 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
834 }
835 DTRACE_CLASSINIT_PROBE_WAIT(error, this_k(), -1,wait);
836 if (e->is_a(SystemDictionary::Error_klass())) {
837 THROW_OOP(e());
838 } else {
839 JavaCallArguments args(e);
840 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
841 vmSymbols::throwable_void_signature(),
842 &args);
843 }
844 }
845 DTRACE_CLASSINIT_PROBE_WAIT(end, this_k(), -1,wait);
846 }
847
848
849 // Note: implementation moved to static method to expose the this pointer.
850 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
851 instanceKlassHandle kh(THREAD, this);
852 set_initialization_state_and_notify_impl(kh, state, CHECK);
853 }
854
855 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_k, ClassState state, TRAPS) {
856 oop init_lock = this_k->init_lock();
857 if (init_lock != NULL) {
858 ObjectLocker ol(init_lock, THREAD);
859 this_k->set_init_state(state);
860 this_k->fence_and_clear_init_lock();
861 ol.notify_all(CHECK);
862 } else {
863 assert(init_lock != NULL, "The initialization state should never be set twice");
864 this_k->set_init_state(state);
865 }
866 }
867
868 // The embedded _implementor field can only record one implementor.
869 // When there are more than one implementors, the _implementor field
870 // is set to the interface Klass* itself. Following are the possible
871 // values for the _implementor field:
872 // NULL - no implementor
873 // implementor Klass* - one implementor
874 // self - more than one implementor
875 //
876 // The _implementor field only exists for interfaces.
877 void InstanceKlass::add_implementor(Klass* k) {
878 assert(Compile_lock->owned_by_self(), "");
879 assert(is_interface(), "not interface");
880 // Filter out my subinterfaces.
881 // (Note: Interfaces are never on the subklass list.)
882 if (InstanceKlass::cast(k)->is_interface()) return;
883
884 // Filter out subclasses whose supers already implement me.
885 // (Note: CHA must walk subclasses of direct implementors
886 // in order to locate indirect implementors.)
887 Klass* sk = k->super();
888 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
889 // We only need to check one immediate superclass, since the
890 // implements_interface query looks at transitive_interfaces.
891 // Any supers of the super have the same (or fewer) transitive_interfaces.
892 return;
893
894 Klass* ik = implementor();
895 if (ik == NULL) {
896 set_implementor(k);
897 } else if (ik != this) {
898 // There is already an implementor. Use itself as an indicator of
899 // more than one implementors.
900 set_implementor(this);
901 }
902
903 // The implementor also implements the transitive_interfaces
904 for (int index = 0; index < local_interfaces()->length(); index++) {
905 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
906 }
907 }
908
909 void InstanceKlass::init_implementor() {
910 if (is_interface()) {
911 set_implementor(NULL);
912 }
913 }
914
915
916 void InstanceKlass::process_interfaces(Thread *thread) {
917 // link this class into the implementors list of every interface it implements
918 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
919 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
920 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
921 assert(interf->is_interface(), "expected interface");
922 interf->add_implementor(this);
923 }
924 }
925
926 bool InstanceKlass::can_be_primary_super_slow() const {
927 if (is_interface())
928 return false;
929 else
930 return Klass::can_be_primary_super_slow();
931 }
932
933 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
934 // The secondaries are the implemented interfaces.
935 Array<Klass*>* interfaces = transitive_interfaces();
936 int num_secondaries = num_extra_slots + interfaces->length();
937 if (num_secondaries == 0) {
938 // Must share this for correct bootstrapping!
939 set_secondary_supers(Universe::the_empty_klass_array());
940 return NULL;
941 } else if (num_extra_slots == 0) {
942 // The secondary super list is exactly the same as the transitive interfaces.
943 // Redefine classes has to be careful not to delete this!
944 set_secondary_supers(interfaces);
945 return NULL;
946 } else {
947 // Copy transitive interfaces to a temporary growable array to be constructed
948 // into the secondary super list with extra slots.
949 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
950 for (int i = 0; i < interfaces->length(); i++) {
951 secondaries->push(interfaces->at(i));
952 }
953 return secondaries;
954 }
955 }
956
957 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
958 if (k->is_interface()) {
959 return implements_interface(k);
960 } else {
961 return Klass::compute_is_subtype_of(k);
962 }
963 }
964
965 bool InstanceKlass::implements_interface(Klass* k) const {
966 if (this == k) return true;
967 assert(k->is_interface(), "should be an interface class");
968 for (int i = 0; i < transitive_interfaces()->length(); i++) {
969 if (transitive_interfaces()->at(i) == k) {
970 return true;
971 }
972 }
973 return false;
974 }
975
976 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
977 // Verify direct super interface
978 if (this == k) return true;
979 assert(k->is_interface(), "should be an interface class");
980 for (int i = 0; i < local_interfaces()->length(); i++) {
981 if (local_interfaces()->at(i) == k) {
982 return true;
983 }
984 }
985 return false;
986 }
987
988 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
989 if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
990 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
991 report_java_out_of_memory("Requested array size exceeds VM limit");
992 JvmtiExport::post_array_size_exhausted();
993 THROW_OOP_0(Universe::out_of_memory_error_array_size());
994 }
995 int size = objArrayOopDesc::object_size(length);
996 Klass* ak = array_klass(n, CHECK_NULL);
997 KlassHandle h_ak (THREAD, ak);
998 objArrayOop o =
999 (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
1000 return o;
1001 }
1002
1003 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1004 if (TraceFinalizerRegistration) {
1005 tty->print("Registered ");
1006 i->print_value_on(tty);
1007 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1008 }
1009 instanceHandle h_i(THREAD, i);
1010 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1011 JavaValue result(T_VOID);
1012 JavaCallArguments args(h_i);
1013 methodHandle mh (THREAD, Universe::finalizer_register_method());
1014 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1015 return h_i();
1016 }
1017
1018 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1019 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1020 int size = size_helper(); // Query before forming handle.
1021
1022 KlassHandle h_k(THREAD, this);
1023
1024 instanceOop i;
1025
1026 i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
1027 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1028 i = register_finalizer(i, CHECK_NULL);
1029 }
1030 return i;
1031 }
1032
1033 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1034 if (is_interface() || is_abstract()) {
1035 ResourceMark rm(THREAD);
1036 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1037 : vmSymbols::java_lang_InstantiationException(), external_name());
1038 }
1039 if (this == SystemDictionary::Class_klass()) {
1040 ResourceMark rm(THREAD);
1041 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1042 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1043 }
1044 }
1045
1046 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1047 instanceKlassHandle this_k(THREAD, this);
1048 return array_klass_impl(this_k, or_null, n, THREAD);
1049 }
1050
1051 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_k, bool or_null, int n, TRAPS) {
1052 // Need load-acquire for lock-free read
1053 if (this_k->array_klasses_acquire() == NULL) {
1054 if (or_null) return NULL;
1055
1056 ResourceMark rm;
1057 JavaThread *jt = (JavaThread *)THREAD;
1058 {
1059 // Atomic creation of array_klasses
1060 MutexLocker mc(Compile_lock, THREAD); // for vtables
1061 MutexLocker ma(MultiArray_lock, THREAD);
1062
1063 // Check if update has already taken place
1064 if (this_k->array_klasses() == NULL) {
1065 Klass* k = ObjArrayKlass::allocate_objArray_klass(this_k->class_loader_data(), 1, this_k, CHECK_NULL);
1066 // use 'release' to pair with lock-free load
1067 this_k->release_set_array_klasses(k);
1068 }
1069 }
1070 }
1071 // _this will always be set at this point
1072 ObjArrayKlass* oak = (ObjArrayKlass*)this_k->array_klasses();
1073 if (or_null) {
1074 return oak->array_klass_or_null(n);
1075 }
1076 return oak->array_klass(n, THREAD);
1077 }
1078
1079 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1080 return array_klass_impl(or_null, 1, THREAD);
1081 }
1082
1083 void InstanceKlass::call_class_initializer(TRAPS) {
1084 instanceKlassHandle ik (THREAD, this);
1085 call_class_initializer_impl(ik, THREAD);
1086 }
1087
1088 static int call_class_initializer_impl_counter = 0; // for debugging
1089
1090 Method* InstanceKlass::class_initializer() {
1091 Method* clinit = find_method(
1092 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1093 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1094 return clinit;
1095 }
1096 return NULL;
1097 }
1098
1099 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_k, TRAPS) {
1100 if (ReplayCompiles &&
1101 (ReplaySuppressInitializers == 1 ||
1102 ReplaySuppressInitializers >= 2 && this_k->class_loader() != NULL)) {
1103 // Hide the existence of the initializer for the purpose of replaying the compile
1104 return;
1105 }
1106
1107 methodHandle h_method(THREAD, this_k->class_initializer());
1108 assert(!this_k->is_initialized(), "we cannot initialize twice");
1109 if (log_is_enabled(Info, class, init)) {
1110 ResourceMark rm;
1111 outputStream* log = Log(class, init)::info_stream();
1112 log->print("%d Initializing ", call_class_initializer_impl_counter++);
1113 this_k->name()->print_value_on(log);
1114 log->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this_k()));
1115 }
1116 if (h_method() != NULL) {
1117 JavaCallArguments args; // No arguments
1118 JavaValue result(T_VOID);
1119 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1120 }
1121 }
1122
1123
1124 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1125 InterpreterOopMap* entry_for) {
1126 // Lazily create the _oop_map_cache at first request
1127 // Lock-free access requires load_ptr_acquire.
1128 OopMapCache* oop_map_cache =
1129 static_cast<OopMapCache*>(OrderAccess::load_ptr_acquire(&_oop_map_cache));
1130 if (oop_map_cache == NULL) {
1131 MutexLocker x(OopMapCacheAlloc_lock);
1132 // Check if _oop_map_cache was allocated while we were waiting for this lock
1133 if ((oop_map_cache = _oop_map_cache) == NULL) {
1134 oop_map_cache = new OopMapCache();
1135 // Ensure _oop_map_cache is stable, since it is examined without a lock
1136 OrderAccess::release_store_ptr(&_oop_map_cache, oop_map_cache);
1137 }
1138 }
1139 // _oop_map_cache is constant after init; lookup below does its own locking.
1140 oop_map_cache->lookup(method, bci, entry_for);
1141 }
1142
1143
1144 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1145 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1146 Symbol* f_name = fs.name();
1147 Symbol* f_sig = fs.signature();
1148 if (f_name == name && f_sig == sig) {
1149 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1150 return true;
1151 }
1152 }
1153 return false;
1154 }
1155
1156
1157 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1158 const int n = local_interfaces()->length();
1159 for (int i = 0; i < n; i++) {
1160 Klass* intf1 = local_interfaces()->at(i);
1161 assert(intf1->is_interface(), "just checking type");
1162 // search for field in current interface
1163 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1164 assert(fd->is_static(), "interface field must be static");
1165 return intf1;
1166 }
1167 // search for field in direct superinterfaces
1168 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1169 if (intf2 != NULL) return intf2;
1170 }
1171 // otherwise field lookup fails
1172 return NULL;
1173 }
1174
1175
1176 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1177 // search order according to newest JVM spec (5.4.3.2, p.167).
1178 // 1) search for field in current klass
1179 if (find_local_field(name, sig, fd)) {
1180 return const_cast<InstanceKlass*>(this);
1181 }
1182 // 2) search for field recursively in direct superinterfaces
1183 { Klass* intf = find_interface_field(name, sig, fd);
1184 if (intf != NULL) return intf;
1185 }
1186 // 3) apply field lookup recursively if superclass exists
1187 { Klass* supr = super();
1188 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1189 }
1190 // 4) otherwise field lookup fails
1191 return NULL;
1192 }
1193
1194
1195 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1196 // search order according to newest JVM spec (5.4.3.2, p.167).
1197 // 1) search for field in current klass
1198 if (find_local_field(name, sig, fd)) {
1199 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1200 }
1201 // 2) search for field recursively in direct superinterfaces
1202 if (is_static) {
1203 Klass* intf = find_interface_field(name, sig, fd);
1204 if (intf != NULL) return intf;
1205 }
1206 // 3) apply field lookup recursively if superclass exists
1207 { Klass* supr = super();
1208 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1209 }
1210 // 4) otherwise field lookup fails
1211 return NULL;
1212 }
1213
1214
1215 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1216 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1217 if (fs.offset() == offset) {
1218 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1219 if (fd->is_static() == is_static) return true;
1220 }
1221 }
1222 return false;
1223 }
1224
1225
1226 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1227 Klass* klass = const_cast<InstanceKlass*>(this);
1228 while (klass != NULL) {
1229 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1230 return true;
1231 }
1232 klass = klass->super();
1233 }
1234 return false;
1235 }
1236
1237
1238 void InstanceKlass::methods_do(void f(Method* method)) {
1239 // Methods aren't stable until they are loaded. This can be read outside
1240 // a lock through the ClassLoaderData for profiling
1241 if (!is_loaded()) {
1242 return;
1243 }
1244
1245 int len = methods()->length();
1246 for (int index = 0; index < len; index++) {
1247 Method* m = methods()->at(index);
1248 assert(m->is_method(), "must be method");
1249 f(m);
1250 }
1251 }
1252
1253
1254 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1255 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1256 if (fs.access_flags().is_static()) {
1257 fieldDescriptor& fd = fs.field_descriptor();
1258 cl->do_field(&fd);
1259 }
1260 }
1261 }
1262
1263
1264 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1265 instanceKlassHandle h_this(THREAD, this);
1266 do_local_static_fields_impl(h_this, f, mirror, CHECK);
1267 }
1268
1269
1270 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_k,
1271 void f(fieldDescriptor* fd, Handle, TRAPS), Handle mirror, TRAPS) {
1272 for (JavaFieldStream fs(this_k()); !fs.done(); fs.next()) {
1273 if (fs.access_flags().is_static()) {
1274 fieldDescriptor& fd = fs.field_descriptor();
1275 f(&fd, mirror, CHECK);
1276 }
1277 }
1278 }
1279
1280
1281 static int compare_fields_by_offset(int* a, int* b) {
1282 return a[0] - b[0];
1283 }
1284
1285 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1286 InstanceKlass* super = superklass();
1287 if (super != NULL) {
1288 super->do_nonstatic_fields(cl);
1289 }
1290 fieldDescriptor fd;
1291 int length = java_fields_count();
1292 // In DebugInfo nonstatic fields are sorted by offset.
1293 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1294 int j = 0;
1295 for (int i = 0; i < length; i += 1) {
1296 fd.reinitialize(this, i);
1297 if (!fd.is_static()) {
1298 fields_sorted[j + 0] = fd.offset();
1299 fields_sorted[j + 1] = i;
1300 j += 2;
1301 }
1302 }
1303 if (j > 0) {
1304 length = j;
1305 // _sort_Fn is defined in growableArray.hpp.
1306 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1307 for (int i = 0; i < length; i += 2) {
1308 fd.reinitialize(this, fields_sorted[i + 1]);
1309 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1310 cl->do_field(&fd);
1311 }
1312 }
1313 FREE_C_HEAP_ARRAY(int, fields_sorted);
1314 }
1315
1316
1317 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1318 if (array_klasses() != NULL)
1319 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1320 }
1321
1322 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1323 if (array_klasses() != NULL)
1324 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1325 }
1326
1327 #ifdef ASSERT
1328 static int linear_search(const Array<Method*>* methods,
1329 const Symbol* name,
1330 const Symbol* signature) {
1331 const int len = methods->length();
1332 for (int index = 0; index < len; index++) {
1333 const Method* const m = methods->at(index);
1334 assert(m->is_method(), "must be method");
1335 if (m->signature() == signature && m->name() == name) {
1336 return index;
1337 }
1338 }
1339 return -1;
1340 }
1341 #endif
1342
1343 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1344 int len = methods->length();
1345 // methods are sorted, so do binary search
1346 int l = 0;
1347 int h = len - 1;
1348 while (l <= h) {
1349 int mid = (l + h) >> 1;
1350 Method* m = methods->at(mid);
1351 assert(m->is_method(), "must be method");
1352 int res = m->name()->fast_compare(name);
1353 if (res == 0) {
1354 return mid;
1355 } else if (res < 0) {
1356 l = mid + 1;
1357 } else {
1358 h = mid - 1;
1359 }
1360 }
1361 return -1;
1362 }
1363
1364 // find_method looks up the name/signature in the local methods array
1365 Method* InstanceKlass::find_method(const Symbol* name,
1366 const Symbol* signature) const {
1367 return find_method_impl(name, signature, find_overpass, find_static, find_private);
1368 }
1369
1370 Method* InstanceKlass::find_method_impl(const Symbol* name,
1371 const Symbol* signature,
1372 OverpassLookupMode overpass_mode,
1373 StaticLookupMode static_mode,
1374 PrivateLookupMode private_mode) const {
1375 return InstanceKlass::find_method_impl(methods(),
1376 name,
1377 signature,
1378 overpass_mode,
1379 static_mode,
1380 private_mode);
1381 }
1382
1383 // find_instance_method looks up the name/signature in the local methods array
1384 // and skips over static methods
1385 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1386 const Symbol* name,
1387 const Symbol* signature) {
1388 Method* const meth = InstanceKlass::find_method_impl(methods,
1389 name,
1390 signature,
1391 find_overpass,
1392 skip_static,
1393 find_private);
1394 assert(((meth == NULL) || !meth->is_static()),
1395 "find_instance_method should have skipped statics");
1396 return meth;
1397 }
1398
1399 // find_instance_method looks up the name/signature in the local methods array
1400 // and skips over static methods
1401 Method* InstanceKlass::find_instance_method(const Symbol* name, const Symbol* signature) const {
1402 return InstanceKlass::find_instance_method(methods(), name, signature);
1403 }
1404
1405 // Find looks up the name/signature in the local methods array
1406 // and filters on the overpass, static and private flags
1407 // This returns the first one found
1408 // note that the local methods array can have up to one overpass, one static
1409 // and one instance (private or not) with the same name/signature
1410 Method* InstanceKlass::find_local_method(const Symbol* name,
1411 const Symbol* signature,
1412 OverpassLookupMode overpass_mode,
1413 StaticLookupMode static_mode,
1414 PrivateLookupMode private_mode) const {
1415 return InstanceKlass::find_method_impl(methods(),
1416 name,
1417 signature,
1418 overpass_mode,
1419 static_mode,
1420 private_mode);
1421 }
1422
1423 // Find looks up the name/signature in the local methods array
1424 // and filters on the overpass, static and private flags
1425 // This returns the first one found
1426 // note that the local methods array can have up to one overpass, one static
1427 // and one instance (private or not) with the same name/signature
1428 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1429 const Symbol* name,
1430 const Symbol* signature,
1431 OverpassLookupMode overpass_mode,
1432 StaticLookupMode static_mode,
1433 PrivateLookupMode private_mode) {
1434 return InstanceKlass::find_method_impl(methods,
1435 name,
1436 signature,
1437 overpass_mode,
1438 static_mode,
1439 private_mode);
1440 }
1441
1442 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1443 const Symbol* name,
1444 const Symbol* signature) {
1445 return InstanceKlass::find_method_impl(methods,
1446 name,
1447 signature,
1448 find_overpass,
1449 find_static,
1450 find_private);
1451 }
1452
1453 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1454 const Symbol* name,
1455 const Symbol* signature,
1456 OverpassLookupMode overpass_mode,
1457 StaticLookupMode static_mode,
1458 PrivateLookupMode private_mode) {
1459 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1460 return hit >= 0 ? methods->at(hit): NULL;
1461 }
1462
1463 // true if method matches signature and conforms to skipping_X conditions.
1464 static bool method_matches(const Method* m,
1465 const Symbol* signature,
1466 bool skipping_overpass,
1467 bool skipping_static,
1468 bool skipping_private) {
1469 return ((m->signature() == signature) &&
1470 (!skipping_overpass || !m->is_overpass()) &&
1471 (!skipping_static || !m->is_static()) &&
1472 (!skipping_private || !m->is_private()));
1473 }
1474
1475 // Used directly for default_methods to find the index into the
1476 // default_vtable_indices, and indirectly by find_method
1477 // find_method_index looks in the local methods array to return the index
1478 // of the matching name/signature. If, overpass methods are being ignored,
1479 // the search continues to find a potential non-overpass match. This capability
1480 // is important during method resolution to prefer a static method, for example,
1481 // over an overpass method.
1482 // There is the possibility in any _method's array to have the same name/signature
1483 // for a static method, an overpass method and a local instance method
1484 // To correctly catch a given method, the search criteria may need
1485 // to explicitly skip the other two. For local instance methods, it
1486 // is often necessary to skip private methods
1487 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1488 const Symbol* name,
1489 const Symbol* signature,
1490 OverpassLookupMode overpass_mode,
1491 StaticLookupMode static_mode,
1492 PrivateLookupMode private_mode) {
1493 const bool skipping_overpass = (overpass_mode == skip_overpass);
1494 const bool skipping_static = (static_mode == skip_static);
1495 const bool skipping_private = (private_mode == skip_private);
1496 const int hit = binary_search(methods, name);
1497 if (hit != -1) {
1498 const Method* const m = methods->at(hit);
1499
1500 // Do linear search to find matching signature. First, quick check
1501 // for common case, ignoring overpasses if requested.
1502 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1503 return hit;
1504 }
1505
1506 // search downwards through overloaded methods
1507 int i;
1508 for (i = hit - 1; i >= 0; --i) {
1509 const Method* const m = methods->at(i);
1510 assert(m->is_method(), "must be method");
1511 if (m->name() != name) {
1512 break;
1513 }
1514 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1515 return i;
1516 }
1517 }
1518 // search upwards
1519 for (i = hit + 1; i < methods->length(); ++i) {
1520 const Method* const m = methods->at(i);
1521 assert(m->is_method(), "must be method");
1522 if (m->name() != name) {
1523 break;
1524 }
1525 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1526 return i;
1527 }
1528 }
1529 // not found
1530 #ifdef ASSERT
1531 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1532 linear_search(methods, name, signature);
1533 assert(-1 == index, "binary search should have found entry %d", index);
1534 #endif
1535 }
1536 return -1;
1537 }
1538
1539 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1540 return find_method_by_name(methods(), name, end);
1541 }
1542
1543 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1544 const Symbol* name,
1545 int* end_ptr) {
1546 assert(end_ptr != NULL, "just checking");
1547 int start = binary_search(methods, name);
1548 int end = start + 1;
1549 if (start != -1) {
1550 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1551 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1552 *end_ptr = end;
1553 return start;
1554 }
1555 return -1;
1556 }
1557
1558 // uncached_lookup_method searches both the local class methods array and all
1559 // superclasses methods arrays, skipping any overpass methods in superclasses.
1560 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1561 const Symbol* signature,
1562 OverpassLookupMode overpass_mode) const {
1563 OverpassLookupMode overpass_local_mode = overpass_mode;
1564 const Klass* klass = this;
1565 while (klass != NULL) {
1566 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1567 signature,
1568 overpass_local_mode,
1569 find_static,
1570 find_private);
1571 if (method != NULL) {
1572 return method;
1573 }
1574 klass = klass->super();
1575 overpass_local_mode = skip_overpass; // Always ignore overpass methods in superclasses
1576 }
1577 return NULL;
1578 }
1579
1580 #ifdef ASSERT
1581 // search through class hierarchy and return true if this class or
1582 // one of the superclasses was redefined
1583 bool InstanceKlass::has_redefined_this_or_super() const {
1584 const Klass* klass = this;
1585 while (klass != NULL) {
1586 if (InstanceKlass::cast(klass)->has_been_redefined()) {
1587 return true;
1588 }
1589 klass = klass->super();
1590 }
1591 return false;
1592 }
1593 #endif
1594
1595 // lookup a method in the default methods list then in all transitive interfaces
1596 // Do NOT return private or static methods
1597 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1598 Symbol* signature) const {
1599 Method* m = NULL;
1600 if (default_methods() != NULL) {
1601 m = find_method(default_methods(), name, signature);
1602 }
1603 // Look up interfaces
1604 if (m == NULL) {
1605 m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1606 }
1607 return m;
1608 }
1609
1610 // lookup a method in all the interfaces that this class implements
1611 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1612 // They should only be found in the initial InterfaceMethodRef
1613 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1614 Symbol* signature,
1615 DefaultsLookupMode defaults_mode) const {
1616 Array<Klass*>* all_ifs = transitive_interfaces();
1617 int num_ifs = all_ifs->length();
1618 InstanceKlass *ik = NULL;
1619 for (int i = 0; i < num_ifs; i++) {
1620 ik = InstanceKlass::cast(all_ifs->at(i));
1621 Method* m = ik->lookup_method(name, signature);
1622 if (m != NULL && m->is_public() && !m->is_static() &&
1623 ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1624 return m;
1625 }
1626 }
1627 return NULL;
1628 }
1629
1630 /* jni_id_for_impl for jfieldIds only */
1631 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_k, int offset) {
1632 MutexLocker ml(JfieldIdCreation_lock);
1633 // Retry lookup after we got the lock
1634 JNIid* probe = this_k->jni_ids() == NULL ? NULL : this_k->jni_ids()->find(offset);
1635 if (probe == NULL) {
1636 // Slow case, allocate new static field identifier
1637 probe = new JNIid(this_k(), offset, this_k->jni_ids());
1638 this_k->set_jni_ids(probe);
1639 }
1640 return probe;
1641 }
1642
1643
1644 /* jni_id_for for jfieldIds only */
1645 JNIid* InstanceKlass::jni_id_for(int offset) {
1646 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1647 if (probe == NULL) {
1648 probe = jni_id_for_impl(this, offset);
1649 }
1650 return probe;
1651 }
1652
1653 u2 InstanceKlass::enclosing_method_data(int offset) const {
1654 const Array<jushort>* const inner_class_list = inner_classes();
1655 if (inner_class_list == NULL) {
1656 return 0;
1657 }
1658 const int length = inner_class_list->length();
1659 if (length % inner_class_next_offset == 0) {
1660 return 0;
1661 }
1662 const int index = length - enclosing_method_attribute_size;
1663 assert(offset < enclosing_method_attribute_size, "invalid offset");
1664 return inner_class_list->at(index + offset);
1665 }
1666
1667 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1668 u2 method_index) {
1669 Array<jushort>* inner_class_list = inner_classes();
1670 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1671 int length = inner_class_list->length();
1672 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1673 int index = length - enclosing_method_attribute_size;
1674 inner_class_list->at_put(
1675 index + enclosing_method_class_index_offset, class_index);
1676 inner_class_list->at_put(
1677 index + enclosing_method_method_index_offset, method_index);
1678 }
1679 }
1680
1681 // Lookup or create a jmethodID.
1682 // This code is called by the VMThread and JavaThreads so the
1683 // locking has to be done very carefully to avoid deadlocks
1684 // and/or other cache consistency problems.
1685 //
1686 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, const methodHandle& method_h) {
1687 size_t idnum = (size_t)method_h->method_idnum();
1688 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1689 size_t length = 0;
1690 jmethodID id = NULL;
1691
1692 // We use a double-check locking idiom here because this cache is
1693 // performance sensitive. In the normal system, this cache only
1694 // transitions from NULL to non-NULL which is safe because we use
1695 // release_set_methods_jmethod_ids() to advertise the new cache.
1696 // A partially constructed cache should never be seen by a racing
1697 // thread. We also use release_store_ptr() to save a new jmethodID
1698 // in the cache so a partially constructed jmethodID should never be
1699 // seen either. Cache reads of existing jmethodIDs proceed without a
1700 // lock, but cache writes of a new jmethodID requires uniqueness and
1701 // creation of the cache itself requires no leaks so a lock is
1702 // generally acquired in those two cases.
1703 //
1704 // If the RedefineClasses() API has been used, then this cache can
1705 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1706 // Cache creation requires no leaks and we require safety between all
1707 // cache accesses and freeing of the old cache so a lock is generally
1708 // acquired when the RedefineClasses() API has been used.
1709
1710 if (jmeths != NULL) {
1711 // the cache already exists
1712 if (!ik_h->idnum_can_increment()) {
1713 // the cache can't grow so we can just get the current values
1714 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1715 } else {
1716 // cache can grow so we have to be more careful
1717 if (Threads::number_of_threads() == 0 ||
1718 SafepointSynchronize::is_at_safepoint()) {
1719 // we're single threaded or at a safepoint - no locking needed
1720 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1721 } else {
1722 MutexLocker ml(JmethodIdCreation_lock);
1723 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1724 }
1725 }
1726 }
1727 // implied else:
1728 // we need to allocate a cache so default length and id values are good
1729
1730 if (jmeths == NULL || // no cache yet
1731 length <= idnum || // cache is too short
1732 id == NULL) { // cache doesn't contain entry
1733
1734 // This function can be called by the VMThread so we have to do all
1735 // things that might block on a safepoint before grabbing the lock.
1736 // Otherwise, we can deadlock with the VMThread or have a cache
1737 // consistency issue. These vars keep track of what we might have
1738 // to free after the lock is dropped.
1739 jmethodID to_dealloc_id = NULL;
1740 jmethodID* to_dealloc_jmeths = NULL;
1741
1742 // may not allocate new_jmeths or use it if we allocate it
1743 jmethodID* new_jmeths = NULL;
1744 if (length <= idnum) {
1745 // allocate a new cache that might be used
1746 size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1747 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1748 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1749 // cache size is stored in element[0], other elements offset by one
1750 new_jmeths[0] = (jmethodID)size;
1751 }
1752
1753 // allocate a new jmethodID that might be used
1754 jmethodID new_id = NULL;
1755 if (method_h->is_old() && !method_h->is_obsolete()) {
1756 // The method passed in is old (but not obsolete), we need to use the current version
1757 Method* current_method = ik_h->method_with_idnum((int)idnum);
1758 assert(current_method != NULL, "old and but not obsolete, so should exist");
1759 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
1760 } else {
1761 // It is the current version of the method or an obsolete method,
1762 // use the version passed in
1763 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
1764 }
1765
1766 if (Threads::number_of_threads() == 0 ||
1767 SafepointSynchronize::is_at_safepoint()) {
1768 // we're single threaded or at a safepoint - no locking needed
1769 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1770 &to_dealloc_id, &to_dealloc_jmeths);
1771 } else {
1772 MutexLocker ml(JmethodIdCreation_lock);
1773 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1774 &to_dealloc_id, &to_dealloc_jmeths);
1775 }
1776
1777 // The lock has been dropped so we can free resources.
1778 // Free up either the old cache or the new cache if we allocated one.
1779 if (to_dealloc_jmeths != NULL) {
1780 FreeHeap(to_dealloc_jmeths);
1781 }
1782 // free up the new ID since it wasn't needed
1783 if (to_dealloc_id != NULL) {
1784 Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
1785 }
1786 }
1787 return id;
1788 }
1789
1790 // Figure out how many jmethodIDs haven't been allocated, and make
1791 // sure space for them is pre-allocated. This makes getting all
1792 // method ids much, much faster with classes with more than 8
1793 // methods, and has a *substantial* effect on performance with jvmti
1794 // code that loads all jmethodIDs for all classes.
1795 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1796 int new_jmeths = 0;
1797 int length = methods()->length();
1798 for (int index = start_offset; index < length; index++) {
1799 Method* m = methods()->at(index);
1800 jmethodID id = m->find_jmethod_id_or_null();
1801 if (id == NULL) {
1802 new_jmeths++;
1803 }
1804 }
1805 if (new_jmeths != 0) {
1806 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1807 }
1808 }
1809
1810 // Common code to fetch the jmethodID from the cache or update the
1811 // cache with the new jmethodID. This function should never do anything
1812 // that causes the caller to go to a safepoint or we can deadlock with
1813 // the VMThread or have cache consistency issues.
1814 //
1815 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1816 instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1817 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1818 jmethodID** to_dealloc_jmeths_p) {
1819 assert(new_id != NULL, "sanity check");
1820 assert(to_dealloc_id_p != NULL, "sanity check");
1821 assert(to_dealloc_jmeths_p != NULL, "sanity check");
1822 assert(Threads::number_of_threads() == 0 ||
1823 SafepointSynchronize::is_at_safepoint() ||
1824 JmethodIdCreation_lock->owned_by_self(), "sanity check");
1825
1826 // reacquire the cache - we are locked, single threaded or at a safepoint
1827 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1828 jmethodID id = NULL;
1829 size_t length = 0;
1830
1831 if (jmeths == NULL || // no cache yet
1832 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
1833 if (jmeths != NULL) {
1834 // copy any existing entries from the old cache
1835 for (size_t index = 0; index < length; index++) {
1836 new_jmeths[index+1] = jmeths[index+1];
1837 }
1838 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
1839 }
1840 ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1841 } else {
1842 // fetch jmethodID (if any) from the existing cache
1843 id = jmeths[idnum+1];
1844 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
1845 }
1846 if (id == NULL) {
1847 // No matching jmethodID in the existing cache or we have a new
1848 // cache or we just grew the cache. This cache write is done here
1849 // by the first thread to win the foot race because a jmethodID
1850 // needs to be unique once it is generally available.
1851 id = new_id;
1852
1853 // The jmethodID cache can be read while unlocked so we have to
1854 // make sure the new jmethodID is complete before installing it
1855 // in the cache.
1856 OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1857 } else {
1858 *to_dealloc_id_p = new_id; // save new id for later delete
1859 }
1860 return id;
1861 }
1862
1863
1864 // Common code to get the jmethodID cache length and the jmethodID
1865 // value at index idnum if there is one.
1866 //
1867 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1868 size_t idnum, size_t *length_p, jmethodID* id_p) {
1869 assert(cache != NULL, "sanity check");
1870 assert(length_p != NULL, "sanity check");
1871 assert(id_p != NULL, "sanity check");
1872
1873 // cache size is stored in element[0], other elements offset by one
1874 *length_p = (size_t)cache[0];
1875 if (*length_p <= idnum) { // cache is too short
1876 *id_p = NULL;
1877 } else {
1878 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
1879 }
1880 }
1881
1882
1883 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
1884 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1885 size_t idnum = (size_t)method->method_idnum();
1886 jmethodID* jmeths = methods_jmethod_ids_acquire();
1887 size_t length; // length assigned as debugging crumb
1888 jmethodID id = NULL;
1889 if (jmeths != NULL && // If there is a cache
1890 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
1891 id = jmeths[idnum+1]; // Look up the id (may be NULL)
1892 }
1893 return id;
1894 }
1895
1896 inline DependencyContext InstanceKlass::dependencies() {
1897 DependencyContext dep_context(&_dep_context);
1898 return dep_context;
1899 }
1900
1901 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
1902 return dependencies().mark_dependent_nmethods(changes);
1903 }
1904
1905 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1906 dependencies().add_dependent_nmethod(nm);
1907 }
1908
1909 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
1910 dependencies().remove_dependent_nmethod(nm, delete_immediately);
1911 }
1912
1913 #ifndef PRODUCT
1914 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1915 dependencies().print_dependent_nmethods(verbose);
1916 }
1917
1918 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1919 return dependencies().is_dependent_nmethod(nm);
1920 }
1921 #endif //PRODUCT
1922
1923 void InstanceKlass::clean_weak_instanceklass_links(BoolObjectClosure* is_alive) {
1924 clean_implementors_list(is_alive);
1925 clean_method_data(is_alive);
1926
1927 // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here.
1928 DependencyContext dep_context(&_dep_context);
1929 dep_context.expunge_stale_entries();
1930 }
1931
1932 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
1933 assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
1934 if (is_interface()) {
1935 if (ClassUnloading) {
1936 Klass* impl = implementor();
1937 if (impl != NULL) {
1938 if (!impl->is_loader_alive(is_alive)) {
1939 // remove this guy
1940 Klass** klass = adr_implementor();
1941 assert(klass != NULL, "null klass");
1942 if (klass != NULL) {
1943 *klass = NULL;
1944 }
1945 }
1946 }
1947 }
1948 }
1949 }
1950
1951 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
1952 for (int m = 0; m < methods()->length(); m++) {
1953 MethodData* mdo = methods()->at(m)->method_data();
1954 if (mdo != NULL) {
1955 mdo->clean_method_data(is_alive);
1956 }
1957 }
1958 }
1959
1960 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
1961 if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
1962 ResourceMark rm;
1963 log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
1964 return false;
1965 }
1966
1967 Array<Klass*>* local_interfaces = this->local_interfaces();
1968 if (local_interfaces != NULL) {
1969 int length = local_interfaces->length();
1970 for (int i = 0; i < length; i++) {
1971 InstanceKlass* intf = InstanceKlass::cast(local_interfaces->at(i));
1972 if (!intf->has_passed_fingerprint_check()) {
1973 ResourceMark rm;
1974 log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
1975 return false;
1976 }
1977 }
1978 }
1979
1980 return true;
1981 }
1982
1983 bool InstanceKlass::should_store_fingerprint() {
1984 #if INCLUDE_AOT
1985 // We store the fingerprint into the InstanceKlass only in the following 2 cases:
1986 if (EnableJVMCI && !UseJVMCICompiler) {
1987 // (1) We are running AOT to generate a shared library.
1988 return true;
1989 }
1990 if (DumpSharedSpaces) {
1991 // (2) We are running -Xshare:dump to create a shared archive
1992 return true;
1993 }
1994 #endif
1995
1996 // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
1997 // but do not store the 64-bit fingerprint to save space.
1998 return false;
1999 }
2000
2001 bool InstanceKlass::has_stored_fingerprint() const {
2002 #if INCLUDE_AOT
2003 return should_store_fingerprint() || is_shared();
2004 #else
2005 return false;
2006 #endif
2007 }
2008
2009 uint64_t InstanceKlass::get_stored_fingerprint() const {
2010 address adr = adr_fingerprint();
2011 if (adr != NULL) {
2012 return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
2013 }
2014 return 0;
2015 }
2016
2017 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
2018 address adr = adr_fingerprint();
2019 if (adr != NULL) {
2020 Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2021
2022 ResourceMark rm;
2023 log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2024 }
2025 }
2026
2027 static void remove_unshareable_in_class(Klass* k) {
2028 // remove klass's unshareable info
2029 k->remove_unshareable_info();
2030 }
2031
2032 void InstanceKlass::remove_unshareable_info() {
2033 Klass::remove_unshareable_info();
2034 // Unlink the class
2035 if (is_linked()) {
2036 unlink_class();
2037 }
2038 init_implementor();
2039
2040 constants()->remove_unshareable_info();
2041
2042 assert(_dep_context == DependencyContext::EMPTY, "dependency context is not shareable");
2043
2044 for (int i = 0; i < methods()->length(); i++) {
2045 Method* m = methods()->at(i);
2046 m->remove_unshareable_info();
2047 }
2048
2049 // do array classes also.
2050 array_klasses_do(remove_unshareable_in_class);
2051 }
2052
2053 static void restore_unshareable_in_class(Klass* k, TRAPS) {
2054 // Array classes have null protection domain.
2055 // --> see ArrayKlass::complete_create_array_klass()
2056 k->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2057 }
2058
2059 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2060 instanceKlassHandle ik(THREAD, this);
2061 ik->set_package(loader_data, CHECK);
2062 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2063
2064 Array<Method*>* methods = ik->methods();
2065 int num_methods = methods->length();
2066 for (int index2 = 0; index2 < num_methods; ++index2) {
2067 methodHandle m(THREAD, methods->at(index2));
2068 m->restore_unshareable_info(CHECK);
2069 }
2070 if (JvmtiExport::has_redefined_a_class()) {
2071 // Reinitialize vtable because RedefineClasses may have changed some
2072 // entries in this vtable for super classes so the CDS vtable might
2073 // point to old or obsolete entries. RedefineClasses doesn't fix up
2074 // vtables in the shared system dictionary, only the main one.
2075 // It also redefines the itable too so fix that too.
2076 ResourceMark rm(THREAD);
2077 ik->vtable()->initialize_vtable(false, CHECK);
2078 ik->itable()->initialize_itable(false, CHECK);
2079 }
2080
2081 // restore constant pool resolved references
2082 ik->constants()->restore_unshareable_info(CHECK);
2083
2084 ik->array_klasses_do(restore_unshareable_in_class, CHECK);
2085 }
2086
2087 // returns true IFF is_in_error_state() has been changed as a result of this call.
2088 bool InstanceKlass::check_sharing_error_state() {
2089 assert(DumpSharedSpaces, "should only be called during dumping");
2090 bool old_state = is_in_error_state();
2091
2092 if (!is_in_error_state()) {
2093 bool bad = false;
2094 for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2095 if (sup->is_in_error_state()) {
2096 bad = true;
2097 break;
2098 }
2099 }
2100 if (!bad) {
2101 Array<Klass*>* interfaces = transitive_interfaces();
2102 for (int i = 0; i < interfaces->length(); i++) {
2103 Klass* iface = interfaces->at(i);
2104 if (InstanceKlass::cast(iface)->is_in_error_state()) {
2105 bad = true;
2106 break;
2107 }
2108 }
2109 }
2110
2111 if (bad) {
2112 set_in_error_state();
2113 }
2114 }
2115
2116 return (old_state != is_in_error_state());
2117 }
2118
2119 #if INCLUDE_JVMTI
2120 static void clear_all_breakpoints(Method* m) {
2121 m->clear_all_breakpoints();
2122 }
2123 #endif
2124
2125 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2126 // notify the debugger
2127 if (JvmtiExport::should_post_class_unload()) {
2128 JvmtiExport::post_class_unload(ik);
2129 }
2130
2131 // notify ClassLoadingService of class unload
2132 ClassLoadingService::notify_class_unloaded(ik);
2133 }
2134
2135 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2136 // Clean up C heap
2137 ik->release_C_heap_structures();
2138 ik->constants()->release_C_heap_structures();
2139 }
2140
2141 void InstanceKlass::release_C_heap_structures() {
2142 // Can't release the constant pool here because the constant pool can be
2143 // deallocated separately from the InstanceKlass for default methods and
2144 // redefine classes.
2145
2146 // Deallocate oop map cache
2147 if (_oop_map_cache != NULL) {
2148 delete _oop_map_cache;
2149 _oop_map_cache = NULL;
2150 }
2151
2152 // Deallocate JNI identifiers for jfieldIDs
2153 JNIid::deallocate(jni_ids());
2154 set_jni_ids(NULL);
2155
2156 jmethodID* jmeths = methods_jmethod_ids_acquire();
2157 if (jmeths != (jmethodID*)NULL) {
2158 release_set_methods_jmethod_ids(NULL);
2159 FreeHeap(jmeths);
2160 }
2161
2162 // Deallocate MemberNameTable
2163 {
2164 Mutex* lock_or_null = SafepointSynchronize::is_at_safepoint() ? NULL : MemberNameTable_lock;
2165 MutexLockerEx ml(lock_or_null, Mutex::_no_safepoint_check_flag);
2166 MemberNameTable* mnt = member_names();
2167 if (mnt != NULL) {
2168 delete mnt;
2169 set_member_names(NULL);
2170 }
2171 }
2172
2173 // Release dependencies.
2174 // It is desirable to use DC::remove_all_dependents() here, but, unfortunately,
2175 // it is not safe (see JDK-8143408). The problem is that the klass dependency
2176 // context can contain live dependencies, since there's a race between nmethod &
2177 // klass unloading. If the klass is dead when nmethod unloading happens, relevant
2178 // dependencies aren't removed from the context associated with the class (see
2179 // nmethod::flush_dependencies). It ends up during klass unloading as seemingly
2180 // live dependencies pointing to unloaded nmethods and causes a crash in
2181 // DC::remove_all_dependents() when it touches unloaded nmethod.
2182 dependencies().wipe();
2183
2184 #if INCLUDE_JVMTI
2185 // Deallocate breakpoint records
2186 if (breakpoints() != 0x0) {
2187 methods_do(clear_all_breakpoints);
2188 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2189 }
2190
2191 // deallocate the cached class file
2192 if (_cached_class_file != NULL && !MetaspaceShared::is_in_shared_space(_cached_class_file)) {
2193 os::free(_cached_class_file);
2194 _cached_class_file = NULL;
2195 }
2196 #endif
2197
2198 // Decrement symbol reference counts associated with the unloaded class.
2199 if (_name != NULL) _name->decrement_refcount();
2200 // unreference array name derived from this class name (arrays of an unloaded
2201 // class can't be referenced anymore).
2202 if (_array_name != NULL) _array_name->decrement_refcount();
2203 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2204
2205 assert(_total_instanceKlass_count >= 1, "Sanity check");
2206 Atomic::dec(&_total_instanceKlass_count);
2207 }
2208
2209 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2210 if (array == NULL) {
2211 _source_debug_extension = NULL;
2212 } else {
2213 // Adding one to the attribute length in order to store a null terminator
2214 // character could cause an overflow because the attribute length is
2215 // already coded with an u4 in the classfile, but in practice, it's
2216 // unlikely to happen.
2217 assert((length+1) > length, "Overflow checking");
2218 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2219 for (int i = 0; i < length; i++) {
2220 sde[i] = array[i];
2221 }
2222 sde[length] = '\0';
2223 _source_debug_extension = sde;
2224 }
2225 }
2226
2227 address InstanceKlass::static_field_addr(int offset) {
2228 return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
2229 }
2230
2231
2232 const char* InstanceKlass::signature_name() const {
2233 int hash_len = 0;
2234 char hash_buf[40];
2235
2236 // If this is an anonymous class, append a hash to make the name unique
2237 if (is_anonymous()) {
2238 intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2239 jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2240 hash_len = (int)strlen(hash_buf);
2241 }
2242
2243 // Get the internal name as a c string
2244 const char* src = (const char*) (name()->as_C_string());
2245 const int src_length = (int)strlen(src);
2246
2247 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2248
2249 // Add L as type indicator
2250 int dest_index = 0;
2251 dest[dest_index++] = 'L';
2252
2253 // Add the actual class name
2254 for (int src_index = 0; src_index < src_length; ) {
2255 dest[dest_index++] = src[src_index++];
2256 }
2257
2258 // If we have a hash, append it
2259 for (int hash_index = 0; hash_index < hash_len; ) {
2260 dest[dest_index++] = hash_buf[hash_index++];
2261 }
2262
2263 // Add the semicolon and the NULL
2264 dest[dest_index++] = ';';
2265 dest[dest_index] = '\0';
2266 return dest;
2267 }
2268
2269 // Used to obtain the package name from a fully qualified class name.
2270 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2271 if (name == NULL) {
2272 return NULL;
2273 } else {
2274 if (name->utf8_length() <= 0) {
2275 return NULL;
2276 }
2277 ResourceMark rm;
2278 const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2279 if (package_name == NULL) {
2280 return NULL;
2281 }
2282 Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD);
2283 return pkg_name;
2284 }
2285 }
2286
2287 ModuleEntry* InstanceKlass::module() const {
2288 if (!in_unnamed_package()) {
2289 return _package_entry->module();
2290 }
2291 const Klass* host = host_klass();
2292 if (host == NULL) {
2293 return class_loader_data()->modules()->unnamed_module();
2294 }
2295 return host->class_loader_data()->modules()->unnamed_module();
2296 }
2297
2298 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2299
2300 // ensure java/ packages only loaded by boot or platform builtin loaders
2301 check_prohibited_package(name(), loader_data->class_loader(), CHECK);
2302
2303 TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2304
2305 if (pkg_name != NULL && loader_data != NULL) {
2306
2307 // Find in class loader's package entry table.
2308 _package_entry = loader_data->packages()->lookup_only(pkg_name);
2309
2310 // If the package name is not found in the loader's package
2311 // entry table, it is an indication that the package has not
2312 // been defined. Consider it defined within the unnamed module.
2313 if (_package_entry == NULL) {
2314 ResourceMark rm;
2315
2316 if (!ModuleEntryTable::javabase_defined()) {
2317 // Before java.base is defined during bootstrapping, define all packages in
2318 // the java.base module. If a non-java.base package is erroneously placed
2319 // in the java.base module it will be caught later when java.base
2320 // is defined by ModuleEntryTable::verify_javabase_packages check.
2321 assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2322 _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2323 } else {
2324 assert(loader_data->modules()->unnamed_module() != NULL, "unnamed module is NULL");
2325 _package_entry = loader_data->packages()->lookup(pkg_name,
2326 loader_data->modules()->unnamed_module());
2327 }
2328
2329 // A package should have been successfully created
2330 assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2331 name()->as_C_string(), loader_data->loader_name());
2332 }
2333
2334 if (log_is_enabled(Debug, modules)) {
2335 ResourceMark rm;
2336 ModuleEntry* m = _package_entry->module();
2337 log_trace(modules)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2338 external_name(),
2339 pkg_name->as_C_string(),
2340 loader_data->loader_name(),
2341 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2342 }
2343 } else {
2344 ResourceMark rm;
2345 log_trace(modules)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2346 external_name(),
2347 (loader_data != NULL) ? loader_data->loader_name() : "NULL",
2348 UNNAMED_MODULE);
2349 }
2350 }
2351
2352
2353 // different versions of is_same_class_package
2354
2355 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2356 oop classloader1 = this->class_loader();
2357 PackageEntry* classpkg1 = this->package();
2358 if (class2->is_objArray_klass()) {
2359 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2360 }
2361
2362 oop classloader2;
2363 PackageEntry* classpkg2;
2364 if (class2->is_instance_klass()) {
2365 classloader2 = class2->class_loader();
2366 classpkg2 = class2->package();
2367 } else {
2368 assert(class2->is_typeArray_klass(), "should be type array");
2369 classloader2 = NULL;
2370 classpkg2 = NULL;
2371 }
2372
2373 // Same package is determined by comparing class loader
2374 // and package entries. Both must be the same. This rule
2375 // applies even to classes that are defined in the unnamed
2376 // package, they still must have the same class loader.
2377 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2378 return true;
2379 }
2380
2381 return false;
2382 }
2383
2384 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2385 const Symbol* other_class_name) const {
2386 oop this_class_loader = class_loader();
2387 const Symbol* const this_class_name = name();
2388
2389 return InstanceKlass::is_same_class_package(this_class_loader,
2390 this_class_name,
2391 other_class_loader,
2392 other_class_name);
2393 }
2394
2395 // return true if two classes are in the same package, classloader
2396 // and classname information is enough to determine a class's package
2397 bool InstanceKlass::is_same_class_package(oop class_loader1, const Symbol* class_name1,
2398 oop class_loader2, const Symbol* class_name2) {
2399 if (class_loader1 != class_loader2) {
2400 return false;
2401 } else if (class_name1 == class_name2) {
2402 return true;
2403 } else {
2404 ResourceMark rm;
2405
2406 bool bad_class_name = false;
2407 const char* name1 = ClassLoader::package_from_name((const char*) class_name1->as_C_string(), &bad_class_name);
2408 if (bad_class_name) {
2409 return false;
2410 }
2411
2412 const char* name2 = ClassLoader::package_from_name((const char*) class_name2->as_C_string(), &bad_class_name);
2413 if (bad_class_name) {
2414 return false;
2415 }
2416
2417 if ((name1 == NULL) || (name2 == NULL)) {
2418 // One of the two doesn't have a package. Only return true
2419 // if the other one also doesn't have a package.
2420 return name1 == name2;
2421 }
2422
2423 // Check that package is identical
2424 return (strcmp(name1, name2) == 0);
2425 }
2426 }
2427
2428 // Returns true iff super_method can be overridden by a method in targetclassname
2429 // See JLS 3rd edition 8.4.6.1
2430 // Assumes name-signature match
2431 // "this" is InstanceKlass of super_method which must exist
2432 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2433 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2434 // Private methods can not be overridden
2435 if (super_method->is_private()) {
2436 return false;
2437 }
2438 // If super method is accessible, then override
2439 if ((super_method->is_protected()) ||
2440 (super_method->is_public())) {
2441 return true;
2442 }
2443 // Package-private methods are not inherited outside of package
2444 assert(super_method->is_package_private(), "must be package private");
2445 return(is_same_class_package(targetclassloader(), targetclassname));
2446 }
2447
2448 /* defined for now in jvm.cpp, for historical reasons *--
2449 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2450 Symbol*& simple_name_result, TRAPS) {
2451 ...
2452 }
2453 */
2454
2455 // Only boot and platform class loaders can define classes in "java/" packages.
2456 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2457 Handle class_loader,
2458 TRAPS) {
2459 if (!class_loader.is_null() &&
2460 !SystemDictionary::is_platform_class_loader(class_loader) &&
2461 class_name != NULL) {
2462 ResourceMark rm(THREAD);
2463 char* name = class_name->as_C_string();
2464 if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2465 TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2466 assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2467 name = pkg_name->as_C_string();
2468 const char* class_loader_name = SystemDictionary::loader_name(class_loader());
2469 StringUtils::replace_no_expand(name, "/", ".");
2470 const char* msg_text1 = "Class loader (instance of): ";
2471 const char* msg_text2 = " tried to load prohibited package name: ";
2472 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2473 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2474 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2475 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2476 }
2477 }
2478 return;
2479 }
2480
2481 // tell if two classes have the same enclosing class (at package level)
2482 bool InstanceKlass::is_same_package_member_impl(const InstanceKlass* class1,
2483 const Klass* class2,
2484 TRAPS) {
2485 if (class2 == class1) return true;
2486 if (!class2->is_instance_klass()) return false;
2487
2488 // must be in same package before we try anything else
2489 if (!class1->is_same_class_package(class2))
2490 return false;
2491
2492 // As long as there is an outer1.getEnclosingClass,
2493 // shift the search outward.
2494 const InstanceKlass* outer1 = class1;
2495 for (;;) {
2496 // As we walk along, look for equalities between outer1 and class2.
2497 // Eventually, the walks will terminate as outer1 stops
2498 // at the top-level class around the original class.
2499 bool ignore_inner_is_member;
2500 const Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2501 CHECK_false);
2502 if (next == NULL) break;
2503 if (next == class2) return true;
2504 outer1 = InstanceKlass::cast(next);
2505 }
2506
2507 // Now do the same for class2.
2508 const InstanceKlass* outer2 = InstanceKlass::cast(class2);
2509 for (;;) {
2510 bool ignore_inner_is_member;
2511 Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2512 CHECK_false);
2513 if (next == NULL) break;
2514 // Might as well check the new outer against all available values.
2515 if (next == class1) return true;
2516 if (next == outer1) return true;
2517 outer2 = InstanceKlass::cast(next);
2518 }
2519
2520 // If by this point we have not found an equality between the
2521 // two classes, we know they are in separate package members.
2522 return false;
2523 }
2524
2525 bool InstanceKlass::find_inner_classes_attr(instanceKlassHandle k, int* ooff, int* noff, TRAPS) {
2526 constantPoolHandle i_cp(THREAD, k->constants());
2527 for (InnerClassesIterator iter(k); !iter.done(); iter.next()) {
2528 int ioff = iter.inner_class_info_index();
2529 if (ioff != 0) {
2530 // Check to see if the name matches the class we're looking for
2531 // before attempting to find the class.
2532 if (i_cp->klass_name_at_matches(k, ioff)) {
2533 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2534 if (k() == inner_klass) {
2535 *ooff = iter.outer_class_info_index();
2536 *noff = iter.inner_name_index();
2537 return true;
2538 }
2539 }
2540 }
2541 }
2542 return false;
2543 }
2544
2545 InstanceKlass* InstanceKlass::compute_enclosing_class_impl(const InstanceKlass* k,
2546 bool* inner_is_member,
2547 TRAPS) {
2548 InstanceKlass* outer_klass = NULL;
2549 *inner_is_member = false;
2550 int ooff = 0, noff = 0;
2551 if (find_inner_classes_attr(k, &ooff, &noff, THREAD)) {
2552 constantPoolHandle i_cp(THREAD, k->constants());
2553 if (ooff != 0) {
2554 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2555 outer_klass = InstanceKlass::cast(ok);
2556 *inner_is_member = true;
2557 }
2558 if (NULL == outer_klass) {
2559 // It may be anonymous; try for that.
2560 int encl_method_class_idx = k->enclosing_method_class_index();
2561 if (encl_method_class_idx != 0) {
2562 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2563 outer_klass = InstanceKlass::cast(ok);
2564 *inner_is_member = false;
2565 }
2566 }
2567 }
2568
2569 // If no inner class attribute found for this class.
2570 if (NULL == outer_klass) return NULL;
2571
2572 // Throws an exception if outer klass has not declared k as an inner klass
2573 // We need evidence that each klass knows about the other, or else
2574 // the system could allow a spoof of an inner class to gain access rights.
2575 Reflection::check_for_inner_class(outer_klass, k, *inner_is_member, CHECK_NULL);
2576 return outer_klass;
2577 }
2578
2579 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2580 jint access = access_flags().as_int();
2581
2582 // But check if it happens to be member class.
2583 instanceKlassHandle ik(THREAD, this);
2584 InnerClassesIterator iter(ik);
2585 for (; !iter.done(); iter.next()) {
2586 int ioff = iter.inner_class_info_index();
2587 // Inner class attribute can be zero, skip it.
2588 // Strange but true: JVM spec. allows null inner class refs.
2589 if (ioff == 0) continue;
2590
2591 // only look at classes that are already loaded
2592 // since we are looking for the flags for our self.
2593 Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2594 if ((ik->name() == inner_name)) {
2595 // This is really a member class.
2596 access = iter.inner_access_flags();
2597 break;
2598 }
2599 }
2600 // Remember to strip ACC_SUPER bit
2601 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2602 }
2603
2604 jint InstanceKlass::jvmti_class_status() const {
2605 jint result = 0;
2606
2607 if (is_linked()) {
2608 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2609 }
2610
2611 if (is_initialized()) {
2612 assert(is_linked(), "Class status is not consistent");
2613 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2614 }
2615 if (is_in_error_state()) {
2616 result |= JVMTI_CLASS_STATUS_ERROR;
2617 }
2618 return result;
2619 }
2620
2621 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2622 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2623 int method_table_offset_in_words = ioe->offset()/wordSize;
2624 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2625 / itableOffsetEntry::size();
2626
2627 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2628 // If the interface isn't implemented by the receiver class,
2629 // the VM should throw IncompatibleClassChangeError.
2630 if (cnt >= nof_interfaces) {
2631 THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2632 }
2633
2634 Klass* ik = ioe->interface_klass();
2635 if (ik == holder) break;
2636 }
2637
2638 itableMethodEntry* ime = ioe->first_method_entry(this);
2639 Method* m = ime[index].method();
2640 if (m == NULL) {
2641 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2642 }
2643 return m;
2644 }
2645
2646
2647 #if INCLUDE_JVMTI
2648 // update default_methods for redefineclasses for methods that are
2649 // not yet in the vtable due to concurrent subclass define and superinterface
2650 // redefinition
2651 // Note: those in the vtable, should have been updated via adjust_method_entries
2652 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2653 // search the default_methods for uses of either obsolete or EMCP methods
2654 if (default_methods() != NULL) {
2655 for (int index = 0; index < default_methods()->length(); index ++) {
2656 Method* old_method = default_methods()->at(index);
2657 if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2658 continue; // skip uninteresting entries
2659 }
2660 assert(!old_method->is_deleted(), "default methods may not be deleted");
2661
2662 Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2663
2664 assert(new_method != NULL, "method_with_idnum() should not be NULL");
2665 assert(old_method != new_method, "sanity check");
2666
2667 default_methods()->at_put(index, new_method);
2668 if (log_is_enabled(Info, redefine, class, update)) {
2669 ResourceMark rm;
2670 if (!(*trace_name_printed)) {
2671 log_info(redefine, class, update)
2672 ("adjust: klassname=%s default methods from name=%s",
2673 external_name(), old_method->method_holder()->external_name());
2674 *trace_name_printed = true;
2675 }
2676 log_debug(redefine, class, update, vtables)
2677 ("default method update: %s(%s) ",
2678 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
2679 }
2680 }
2681 }
2682 }
2683 #endif // INCLUDE_JVMTI
2684
2685 // On-stack replacement stuff
2686 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2687 // only one compilation can be active
2688 {
2689 // This is a short non-blocking critical region, so the no safepoint check is ok.
2690 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2691 assert(n->is_osr_method(), "wrong kind of nmethod");
2692 n->set_osr_link(osr_nmethods_head());
2693 set_osr_nmethods_head(n);
2694 // Raise the highest osr level if necessary
2695 if (TieredCompilation) {
2696 Method* m = n->method();
2697 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2698 }
2699 }
2700
2701 // Get rid of the osr methods for the same bci that have lower levels.
2702 if (TieredCompilation) {
2703 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2704 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2705 if (inv != NULL && inv->is_in_use()) {
2706 inv->make_not_entrant();
2707 }
2708 }
2709 }
2710 }
2711
2712 // Remove osr nmethod from the list. Return true if found and removed.
2713 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
2714 // This is a short non-blocking critical region, so the no safepoint check is ok.
2715 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2716 assert(n->is_osr_method(), "wrong kind of nmethod");
2717 nmethod* last = NULL;
2718 nmethod* cur = osr_nmethods_head();
2719 int max_level = CompLevel_none; // Find the max comp level excluding n
2720 Method* m = n->method();
2721 // Search for match
2722 bool found = false;
2723 while(cur != NULL && cur != n) {
2724 if (TieredCompilation && m == cur->method()) {
2725 // Find max level before n
2726 max_level = MAX2(max_level, cur->comp_level());
2727 }
2728 last = cur;
2729 cur = cur->osr_link();
2730 }
2731 nmethod* next = NULL;
2732 if (cur == n) {
2733 found = true;
2734 next = cur->osr_link();
2735 if (last == NULL) {
2736 // Remove first element
2737 set_osr_nmethods_head(next);
2738 } else {
2739 last->set_osr_link(next);
2740 }
2741 }
2742 n->set_osr_link(NULL);
2743 if (TieredCompilation) {
2744 cur = next;
2745 while (cur != NULL) {
2746 // Find max level after n
2747 if (m == cur->method()) {
2748 max_level = MAX2(max_level, cur->comp_level());
2749 }
2750 cur = cur->osr_link();
2751 }
2752 m->set_highest_osr_comp_level(max_level);
2753 }
2754 return found;
2755 }
2756
2757 int InstanceKlass::mark_osr_nmethods(const Method* m) {
2758 // This is a short non-blocking critical region, so the no safepoint check is ok.
2759 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2760 nmethod* osr = osr_nmethods_head();
2761 int found = 0;
2762 while (osr != NULL) {
2763 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2764 if (osr->method() == m) {
2765 osr->mark_for_deoptimization();
2766 found++;
2767 }
2768 osr = osr->osr_link();
2769 }
2770 return found;
2771 }
2772
2773 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2774 // This is a short non-blocking critical region, so the no safepoint check is ok.
2775 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2776 nmethod* osr = osr_nmethods_head();
2777 nmethod* best = NULL;
2778 while (osr != NULL) {
2779 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2780 // There can be a time when a c1 osr method exists but we are waiting
2781 // for a c2 version. When c2 completes its osr nmethod we will trash
2782 // the c1 version and only be able to find the c2 version. However
2783 // while we overflow in the c1 code at back branches we don't want to
2784 // try and switch to the same code as we are already running
2785
2786 if (osr->method() == m &&
2787 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2788 if (match_level) {
2789 if (osr->comp_level() == comp_level) {
2790 // Found a match - return it.
2791 return osr;
2792 }
2793 } else {
2794 if (best == NULL || (osr->comp_level() > best->comp_level())) {
2795 if (osr->comp_level() == CompLevel_highest_tier) {
2796 // Found the best possible - return it.
2797 return osr;
2798 }
2799 best = osr;
2800 }
2801 }
2802 }
2803 osr = osr->osr_link();
2804 }
2805 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2806 return best;
2807 }
2808 return NULL;
2809 }
2810
2811 oop InstanceKlass::add_member_name(Handle mem_name, bool intern) {
2812 jweak mem_name_wref = JNIHandles::make_weak_global(mem_name);
2813 MutexLocker ml(MemberNameTable_lock);
2814 DEBUG_ONLY(NoSafepointVerifier nsv);
2815
2816 // Check if method has been redefined while taking out MemberNameTable_lock, if so
2817 // return false. We cannot cache obsolete methods. They will crash when the function
2818 // is called!
2819 Method* method = (Method*)java_lang_invoke_MemberName::vmtarget(mem_name());
2820 if (method->is_obsolete()) {
2821 return NULL;
2822 } else if (method->is_old()) {
2823 // Replace method with redefined version
2824 java_lang_invoke_MemberName::set_vmtarget(mem_name(), method_with_idnum(method->method_idnum()));
2825 }
2826
2827 if (_member_names == NULL) {
2828 _member_names = new (ResourceObj::C_HEAP, mtClass) MemberNameTable(idnum_allocated_count());
2829 }
2830 if (intern) {
2831 return _member_names->find_or_add_member_name(mem_name_wref);
2832 } else {
2833 return _member_names->add_member_name(mem_name_wref);
2834 }
2835 }
2836
2837 // -----------------------------------------------------------------------------------------------------
2838 // Printing
2839
2840 #ifndef PRODUCT
2841
2842 #define BULLET " - "
2843
2844 static const char* state_names[] = {
2845 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2846 };
2847
2848 static void print_vtable(intptr_t* start, int len, outputStream* st) {
2849 for (int i = 0; i < len; i++) {
2850 intptr_t e = start[i];
2851 st->print("%d : " INTPTR_FORMAT, i, e);
2852 if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2853 st->print(" ");
2854 ((Metadata*)e)->print_value_on(st);
2855 }
2856 st->cr();
2857 }
2858 }
2859
2860 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
2861 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
2862 }
2863
2864 void InstanceKlass::print_on(outputStream* st) const {
2865 assert(is_klass(), "must be klass");
2866 Klass::print_on(st);
2867
2868 st->print(BULLET"instance size: %d", size_helper()); st->cr();
2869 st->print(BULLET"klass size: %d", size()); st->cr();
2870 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
2871 st->print(BULLET"state: "); st->print_cr("%s", state_names[_init_state]);
2872 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
2873 st->print(BULLET"super: "); super()->print_value_on_maybe_null(st); st->cr();
2874 st->print(BULLET"sub: ");
2875 Klass* sub = subklass();
2876 int n;
2877 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2878 if (n < MaxSubklassPrintSize) {
2879 sub->print_value_on(st);
2880 st->print(" ");
2881 }
2882 }
2883 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
2884 st->cr();
2885
2886 if (is_interface()) {
2887 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
2888 if (nof_implementors() == 1) {
2889 st->print_cr(BULLET"implementor: ");
2890 st->print(" ");
2891 implementor()->print_value_on(st);
2892 st->cr();
2893 }
2894 }
2895
2896 st->print(BULLET"arrays: "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2897 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
2898 if (Verbose || WizardMode) {
2899 Array<Method*>* method_array = methods();
2900 for (int i = 0; i < method_array->length(); i++) {
2901 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2902 }
2903 }
2904 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
2905 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
2906 if (Verbose && default_methods() != NULL) {
2907 Array<Method*>* method_array = default_methods();
2908 for (int i = 0; i < method_array->length(); i++) {
2909 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2910 }
2911 }
2912 if (default_vtable_indices() != NULL) {
2913 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
2914 }
2915 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
2916 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2917 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
2918 if (class_loader_data() != NULL) {
2919 st->print(BULLET"class loader data: ");
2920 class_loader_data()->print_value_on(st);
2921 st->cr();
2922 }
2923 st->print(BULLET"host class: "); host_klass()->print_value_on_maybe_null(st); st->cr();
2924 if (source_file_name() != NULL) {
2925 st->print(BULLET"source file: ");
2926 source_file_name()->print_value_on(st);
2927 st->cr();
2928 }
2929 if (source_debug_extension() != NULL) {
2930 st->print(BULLET"source debug extension: ");
2931 st->print("%s", source_debug_extension());
2932 st->cr();
2933 }
2934 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
2935 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
2936 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
2937 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
2938 {
2939 bool have_pv = false;
2940 // previous versions are linked together through the InstanceKlass
2941 for (InstanceKlass* pv_node = previous_versions();
2942 pv_node != NULL;
2943 pv_node = pv_node->previous_versions()) {
2944 if (!have_pv)
2945 st->print(BULLET"previous version: ");
2946 have_pv = true;
2947 pv_node->constants()->print_value_on(st);
2948 }
2949 if (have_pv) st->cr();
2950 }
2951
2952 if (generic_signature() != NULL) {
2953 st->print(BULLET"generic signature: ");
2954 generic_signature()->print_value_on(st);
2955 st->cr();
2956 }
2957 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
2958 st->print(BULLET"java mirror: "); java_mirror()->print_value_on(st); st->cr();
2959 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
2960 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
2961 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
2962 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
2963 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2964 FieldPrinter print_static_field(st);
2965 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2966 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2967 FieldPrinter print_nonstatic_field(st);
2968 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
2969 ik->do_nonstatic_fields(&print_nonstatic_field);
2970
2971 st->print(BULLET"non-static oop maps: ");
2972 OopMapBlock* map = start_of_nonstatic_oop_maps();
2973 OopMapBlock* end_map = map + nonstatic_oop_map_count();
2974 while (map < end_map) {
2975 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2976 map++;
2977 }
2978 st->cr();
2979 }
2980
2981 #endif //PRODUCT
2982
2983 void InstanceKlass::print_value_on(outputStream* st) const {
2984 assert(is_klass(), "must be klass");
2985 if (Verbose || WizardMode) access_flags().print_on(st);
2986 name()->print_value_on(st);
2987 }
2988
2989 #ifndef PRODUCT
2990
2991 void FieldPrinter::do_field(fieldDescriptor* fd) {
2992 _st->print(BULLET);
2993 if (_obj == NULL) {
2994 fd->print_on(_st);
2995 _st->cr();
2996 } else {
2997 fd->print_on_for(_st, _obj);
2998 _st->cr();
2999 }
3000 }
3001
3002
3003 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3004 Klass::oop_print_on(obj, st);
3005
3006 if (this == SystemDictionary::String_klass()) {
3007 typeArrayOop value = java_lang_String::value(obj);
3008 juint length = java_lang_String::length(obj);
3009 if (value != NULL &&
3010 value->is_typeArray() &&
3011 length <= (juint) value->length()) {
3012 st->print(BULLET"string: ");
3013 java_lang_String::print(obj, st);
3014 st->cr();
3015 if (!WizardMode) return; // that is enough
3016 }
3017 }
3018
3019 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3020 FieldPrinter print_field(st, obj);
3021 do_nonstatic_fields(&print_field);
3022
3023 if (this == SystemDictionary::Class_klass()) {
3024 st->print(BULLET"signature: ");
3025 java_lang_Class::print_signature(obj, st);
3026 st->cr();
3027 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3028 st->print(BULLET"fake entry for mirror: ");
3029 mirrored_klass->print_value_on_maybe_null(st);
3030 st->cr();
3031 Klass* array_klass = java_lang_Class::array_klass(obj);
3032 st->print(BULLET"fake entry for array: ");
3033 array_klass->print_value_on_maybe_null(st);
3034 st->cr();
3035 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3036 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3037 Klass* real_klass = java_lang_Class::as_Klass(obj);
3038 if (real_klass != NULL && real_klass->is_instance_klass()) {
3039 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3040 }
3041 } else if (this == SystemDictionary::MethodType_klass()) {
3042 st->print(BULLET"signature: ");
3043 java_lang_invoke_MethodType::print_signature(obj, st);
3044 st->cr();
3045 }
3046 }
3047
3048 #endif //PRODUCT
3049
3050 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3051 st->print("a ");
3052 name()->print_value_on(st);
3053 obj->print_address_on(st);
3054 if (this == SystemDictionary::String_klass()
3055 && java_lang_String::value(obj) != NULL) {
3056 ResourceMark rm;
3057 int len = java_lang_String::length(obj);
3058 int plen = (len < 24 ? len : 12);
3059 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3060 st->print(" = \"%s\"", str);
3061 if (len > plen)
3062 st->print("...[%d]", len);
3063 } else if (this == SystemDictionary::Class_klass()) {
3064 Klass* k = java_lang_Class::as_Klass(obj);
3065 st->print(" = ");
3066 if (k != NULL) {
3067 k->print_value_on(st);
3068 } else {
3069 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3070 st->print("%s", tname ? tname : "type?");
3071 }
3072 } else if (this == SystemDictionary::MethodType_klass()) {
3073 st->print(" = ");
3074 java_lang_invoke_MethodType::print_signature(obj, st);
3075 } else if (java_lang_boxing_object::is_instance(obj)) {
3076 st->print(" = ");
3077 java_lang_boxing_object::print(obj, st);
3078 } else if (this == SystemDictionary::LambdaForm_klass()) {
3079 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3080 if (vmentry != NULL) {
3081 st->print(" => ");
3082 vmentry->print_value_on(st);
3083 }
3084 } else if (this == SystemDictionary::MemberName_klass()) {
3085 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3086 if (vmtarget != NULL) {
3087 st->print(" = ");
3088 vmtarget->print_value_on(st);
3089 } else {
3090 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3091 st->print(".");
3092 java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3093 }
3094 }
3095 }
3096
3097 const char* InstanceKlass::internal_name() const {
3098 return external_name();
3099 }
3100
3101 void InstanceKlass::print_loading_log(LogLevel::type type,
3102 ClassLoaderData* loader_data,
3103 const char* module_name,
3104 const ClassFileStream* cfs) const {
3105 ResourceMark rm;
3106 outputStream* log;
3107
3108 assert(type == LogLevel::Info || type == LogLevel::Debug, "sanity");
3109
3110 if (type == LogLevel::Info) {
3111 log = Log(class, load)::info_stream();
3112 } else {
3113 assert(type == LogLevel::Debug,
3114 "print_loading_log supports only Debug and Info levels");
3115 log = Log(class, load)::debug_stream();
3116 }
3117
3118 // Name and class hierarchy info
3119 log->print("%s", external_name());
3120
3121 // Source
3122 if (cfs != NULL) {
3123 if (cfs->source() != NULL) {
3124 if (module_name != NULL) {
3125 if (ClassLoader::is_jrt(cfs->source())) {
3126 log->print(" source: jrt:/%s", module_name);
3127 } else {
3128 log->print(" source: %s", cfs->source());
3129 }
3130 } else {
3131 log->print(" source: %s", cfs->source());
3132 }
3133 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3134 Thread* THREAD = Thread::current();
3135 Klass* caller =
3136 THREAD->is_Java_thread()
3137 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3138 : NULL;
3139 // caller can be NULL, for example, during a JVMTI VM_Init hook
3140 if (caller != NULL) {
3141 log->print(" source: instance of %s", caller->external_name());
3142 } else {
3143 // source is unknown
3144 }
3145 } else {
3146 Handle class_loader(loader_data->class_loader());
3147 log->print(" source: %s", class_loader->klass()->external_name());
3148 }
3149 } else {
3150 log->print(" source: shared objects file");
3151 }
3152
3153 if (type == LogLevel::Debug) {
3154 // Class hierarchy info
3155 log->print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3156 p2i(this), p2i(superklass()));
3157
3158 if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3159 log->print(" interfaces:");
3160 int length = local_interfaces()->length();
3161 for (int i = 0; i < length; i++) {
3162 log->print(" " INTPTR_FORMAT,
3163 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3164 }
3165 }
3166
3167 // Class loader
3168 log->print(" loader: [");
3169 loader_data->print_value_on(log);
3170 log->print("]");
3171
3172 // Classfile checksum
3173 if (cfs) {
3174 log->print(" bytes: %d checksum: %08x",
3175 cfs->length(),
3176 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3177 cfs->length()));
3178 }
3179 }
3180 log->cr();
3181 }
3182
3183 #if INCLUDE_SERVICES
3184 // Size Statistics
3185 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3186 Klass::collect_statistics(sz);
3187
3188 sz->_inst_size = wordSize * size_helper();
3189 sz->_vtab_bytes = wordSize * vtable_length();
3190 sz->_itab_bytes = wordSize * itable_length();
3191 sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3192
3193 int n = 0;
3194 n += (sz->_methods_array_bytes = sz->count_array(methods()));
3195 n += (sz->_method_ordering_bytes = sz->count_array(method_ordering()));
3196 n += (sz->_local_interfaces_bytes = sz->count_array(local_interfaces()));
3197 n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3198 n += (sz->_fields_bytes = sz->count_array(fields()));
3199 n += (sz->_inner_classes_bytes = sz->count_array(inner_classes()));
3200 sz->_ro_bytes += n;
3201
3202 const ConstantPool* cp = constants();
3203 if (cp) {
3204 cp->collect_statistics(sz);
3205 }
3206
3207 const Annotations* anno = annotations();
3208 if (anno) {
3209 anno->collect_statistics(sz);
3210 }
3211
3212 const Array<Method*>* methods_array = methods();
3213 if (methods()) {
3214 for (int i = 0; i < methods_array->length(); i++) {
3215 Method* method = methods_array->at(i);
3216 if (method) {
3217 sz->_method_count ++;
3218 method->collect_statistics(sz);
3219 }
3220 }
3221 }
3222 }
3223 #endif // INCLUDE_SERVICES
3224
3225 // Verification
3226
3227 class VerifyFieldClosure: public OopClosure {
3228 protected:
3229 template <class T> void do_oop_work(T* p) {
3230 oop obj = oopDesc::load_decode_heap_oop(p);
3231 if (!obj->is_oop_or_null()) {
3232 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3233 Universe::print_on(tty);
3234 guarantee(false, "boom");
3235 }
3236 }
3237 public:
3238 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3239 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3240 };
3241
3242 void InstanceKlass::verify_on(outputStream* st) {
3243 #ifndef PRODUCT
3244 // Avoid redundant verifies, this really should be in product.
3245 if (_verify_count == Universe::verify_count()) return;
3246 _verify_count = Universe::verify_count();
3247 #endif
3248
3249 // Verify Klass
3250 Klass::verify_on(st);
3251
3252 // Verify that klass is present in ClassLoaderData
3253 guarantee(class_loader_data()->contains_klass(this),
3254 "this class isn't found in class loader data");
3255
3256 // Verify vtables
3257 if (is_linked()) {
3258 ResourceMark rm;
3259 // $$$ This used to be done only for m/s collections. Doing it
3260 // always seemed a valid generalization. (DLD -- 6/00)
3261 vtable()->verify(st);
3262 }
3263
3264 // Verify first subklass
3265 if (subklass() != NULL) {
3266 guarantee(subklass()->is_klass(), "should be klass");
3267 }
3268
3269 // Verify siblings
3270 Klass* super = this->super();
3271 Klass* sib = next_sibling();
3272 if (sib != NULL) {
3273 if (sib == this) {
3274 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3275 }
3276
3277 guarantee(sib->is_klass(), "should be klass");
3278 guarantee(sib->super() == super, "siblings should have same superklass");
3279 }
3280
3281 // Verify implementor fields
3282 Klass* im = implementor();
3283 if (im != NULL) {
3284 guarantee(is_interface(), "only interfaces should have implementor set");
3285 guarantee(im->is_klass(), "should be klass");
3286 guarantee(!im->is_interface() || im == this,
3287 "implementors cannot be interfaces");
3288 }
3289
3290 // Verify local interfaces
3291 if (local_interfaces()) {
3292 Array<Klass*>* local_interfaces = this->local_interfaces();
3293 for (int j = 0; j < local_interfaces->length(); j++) {
3294 Klass* e = local_interfaces->at(j);
3295 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3296 }
3297 }
3298
3299 // Verify transitive interfaces
3300 if (transitive_interfaces() != NULL) {
3301 Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3302 for (int j = 0; j < transitive_interfaces->length(); j++) {
3303 Klass* e = transitive_interfaces->at(j);
3304 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3305 }
3306 }
3307
3308 // Verify methods
3309 if (methods() != NULL) {
3310 Array<Method*>* methods = this->methods();
3311 for (int j = 0; j < methods->length(); j++) {
3312 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3313 }
3314 for (int j = 0; j < methods->length() - 1; j++) {
3315 Method* m1 = methods->at(j);
3316 Method* m2 = methods->at(j + 1);
3317 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3318 }
3319 }
3320
3321 // Verify method ordering
3322 if (method_ordering() != NULL) {
3323 Array<int>* method_ordering = this->method_ordering();
3324 int length = method_ordering->length();
3325 if (JvmtiExport::can_maintain_original_method_order() ||
3326 ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3327 guarantee(length == methods()->length(), "invalid method ordering length");
3328 jlong sum = 0;
3329 for (int j = 0; j < length; j++) {
3330 int original_index = method_ordering->at(j);
3331 guarantee(original_index >= 0, "invalid method ordering index");
3332 guarantee(original_index < length, "invalid method ordering index");
3333 sum += original_index;
3334 }
3335 // Verify sum of indices 0,1,...,length-1
3336 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3337 } else {
3338 guarantee(length == 0, "invalid method ordering length");
3339 }
3340 }
3341
3342 // Verify default methods
3343 if (default_methods() != NULL) {
3344 Array<Method*>* methods = this->default_methods();
3345 for (int j = 0; j < methods->length(); j++) {
3346 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3347 }
3348 for (int j = 0; j < methods->length() - 1; j++) {
3349 Method* m1 = methods->at(j);
3350 Method* m2 = methods->at(j + 1);
3351 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3352 }
3353 }
3354
3355 // Verify JNI static field identifiers
3356 if (jni_ids() != NULL) {
3357 jni_ids()->verify(this);
3358 }
3359
3360 // Verify other fields
3361 if (array_klasses() != NULL) {
3362 guarantee(array_klasses()->is_klass(), "should be klass");
3363 }
3364 if (constants() != NULL) {
3365 guarantee(constants()->is_constantPool(), "should be constant pool");
3366 }
3367 const Klass* host = host_klass();
3368 if (host != NULL) {
3369 guarantee(host->is_klass(), "should be klass");
3370 }
3371 }
3372
3373 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3374 Klass::oop_verify_on(obj, st);
3375 VerifyFieldClosure blk;
3376 obj->oop_iterate_no_header(&blk);
3377 }
3378
3379
3380 // JNIid class for jfieldIDs only
3381 // Note to reviewers:
3382 // These JNI functions are just moved over to column 1 and not changed
3383 // in the compressed oops workspace.
3384 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3385 _holder = holder;
3386 _offset = offset;
3387 _next = next;
3388 debug_only(_is_static_field_id = false;)
3389 }
3390
3391
3392 JNIid* JNIid::find(int offset) {
3393 JNIid* current = this;
3394 while (current != NULL) {
3395 if (current->offset() == offset) return current;
3396 current = current->next();
3397 }
3398 return NULL;
3399 }
3400
3401 void JNIid::deallocate(JNIid* current) {
3402 while (current != NULL) {
3403 JNIid* next = current->next();
3404 delete current;
3405 current = next;
3406 }
3407 }
3408
3409
3410 void JNIid::verify(Klass* holder) {
3411 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3412 int end_field_offset;
3413 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3414
3415 JNIid* current = this;
3416 while (current != NULL) {
3417 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3418 #ifdef ASSERT
3419 int o = current->offset();
3420 if (current->is_static_field_id()) {
3421 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3422 }
3423 #endif
3424 current = current->next();
3425 }
3426 }
3427
3428
3429 #ifdef ASSERT
3430 void InstanceKlass::set_init_state(ClassState state) {
3431 bool good_state = is_shared() ? (_init_state <= state)
3432 : (_init_state < state);
3433 assert(good_state || state == allocated, "illegal state transition");
3434 _init_state = (u1)state;
3435 }
3436 #endif
3437
3438 #if INCLUDE_JVMTI
3439
3440 // RedefineClasses() support for previous versions
3441
3442 // Globally, there is at least one previous version of a class to walk
3443 // during class unloading, which is saved because old methods in the class
3444 // are still running. Otherwise the previous version list is cleaned up.
3445 bool InstanceKlass::_has_previous_versions = false;
3446
3447 // Returns true if there are previous versions of a class for class
3448 // unloading only. Also resets the flag to false. purge_previous_version
3449 // will set the flag to true if there are any left, i.e., if there's any
3450 // work to do for next time. This is to avoid the expensive code cache
3451 // walk in CLDG::do_unloading().
3452 bool InstanceKlass::has_previous_versions_and_reset() {
3453 bool ret = _has_previous_versions;
3454 log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3455 ret ? "true" : "false");
3456 _has_previous_versions = false;
3457 return ret;
3458 }
3459
3460 // Purge previous versions before adding new previous versions of the class and
3461 // during class unloading.
3462 void InstanceKlass::purge_previous_version_list() {
3463 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3464 assert(has_been_redefined(), "Should only be called for main class");
3465
3466 // Quick exit.
3467 if (previous_versions() == NULL) {
3468 return;
3469 }
3470
3471 // This klass has previous versions so see what we can cleanup
3472 // while it is safe to do so.
3473
3474 int deleted_count = 0; // leave debugging breadcrumbs
3475 int live_count = 0;
3476 ClassLoaderData* loader_data = class_loader_data();
3477 assert(loader_data != NULL, "should never be null");
3478
3479 ResourceMark rm;
3480 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3481
3482 // previous versions are linked together through the InstanceKlass
3483 InstanceKlass* pv_node = previous_versions();
3484 InstanceKlass* last = this;
3485 int version = 0;
3486
3487 // check the previous versions list
3488 for (; pv_node != NULL; ) {
3489
3490 ConstantPool* pvcp = pv_node->constants();
3491 assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3492
3493 if (!pvcp->on_stack()) {
3494 // If the constant pool isn't on stack, none of the methods
3495 // are executing. Unlink this previous_version.
3496 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3497 // so will be deallocated during the next phase of class unloading.
3498 log_trace(redefine, class, iklass, purge)
3499 ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3500 // For debugging purposes.
3501 pv_node->set_is_scratch_class();
3502 // Unlink from previous version list.
3503 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3504 InstanceKlass* next = pv_node->previous_versions();
3505 pv_node->link_previous_versions(NULL); // point next to NULL
3506 last->link_previous_versions(next);
3507 // Add to the deallocate list after unlinking
3508 loader_data->add_to_deallocate_list(pv_node);
3509 pv_node = next;
3510 deleted_count++;
3511 version++;
3512 continue;
3513 } else {
3514 log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3515 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3516 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3517 live_count++;
3518 // found a previous version for next time we do class unloading
3519 _has_previous_versions = true;
3520 }
3521
3522 // At least one method is live in this previous version.
3523 // Reset dead EMCP methods not to get breakpoints.
3524 // All methods are deallocated when all of the methods for this class are no
3525 // longer running.
3526 Array<Method*>* method_refs = pv_node->methods();
3527 if (method_refs != NULL) {
3528 log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3529 for (int j = 0; j < method_refs->length(); j++) {
3530 Method* method = method_refs->at(j);
3531
3532 if (!method->on_stack()) {
3533 // no breakpoints for non-running methods
3534 if (method->is_running_emcp()) {
3535 method->set_running_emcp(false);
3536 }
3537 } else {
3538 assert (method->is_obsolete() || method->is_running_emcp(),
3539 "emcp method cannot run after emcp bit is cleared");
3540 log_trace(redefine, class, iklass, purge)
3541 ("purge: %s(%s): prev method @%d in version @%d is alive",
3542 method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3543 }
3544 }
3545 }
3546 // next previous version
3547 last = pv_node;
3548 pv_node = pv_node->previous_versions();
3549 version++;
3550 }
3551 log_trace(redefine, class, iklass, purge)
3552 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3553 }
3554
3555 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3556 int emcp_method_count) {
3557 int obsolete_method_count = old_methods->length() - emcp_method_count;
3558
3559 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3560 _previous_versions != NULL) {
3561 // We have a mix of obsolete and EMCP methods so we have to
3562 // clear out any matching EMCP method entries the hard way.
3563 int local_count = 0;
3564 for (int i = 0; i < old_methods->length(); i++) {
3565 Method* old_method = old_methods->at(i);
3566 if (old_method->is_obsolete()) {
3567 // only obsolete methods are interesting
3568 Symbol* m_name = old_method->name();
3569 Symbol* m_signature = old_method->signature();
3570
3571 // previous versions are linked together through the InstanceKlass
3572 int j = 0;
3573 for (InstanceKlass* prev_version = _previous_versions;
3574 prev_version != NULL;
3575 prev_version = prev_version->previous_versions(), j++) {
3576
3577 Array<Method*>* method_refs = prev_version->methods();
3578 for (int k = 0; k < method_refs->length(); k++) {
3579 Method* method = method_refs->at(k);
3580
3581 if (!method->is_obsolete() &&
3582 method->name() == m_name &&
3583 method->signature() == m_signature) {
3584 // The current RedefineClasses() call has made all EMCP
3585 // versions of this method obsolete so mark it as obsolete
3586 log_trace(redefine, class, iklass, add)
3587 ("%s(%s): flush obsolete method @%d in version @%d",
3588 m_name->as_C_string(), m_signature->as_C_string(), k, j);
3589
3590 method->set_is_obsolete();
3591 break;
3592 }
3593 }
3594
3595 // The previous loop may not find a matching EMCP method, but
3596 // that doesn't mean that we can optimize and not go any
3597 // further back in the PreviousVersion generations. The EMCP
3598 // method for this generation could have already been made obsolete,
3599 // but there still may be an older EMCP method that has not
3600 // been made obsolete.
3601 }
3602
3603 if (++local_count >= obsolete_method_count) {
3604 // no more obsolete methods so bail out now
3605 break;
3606 }
3607 }
3608 }
3609 }
3610 }
3611
3612 // Save the scratch_class as the previous version if any of the methods are running.
3613 // The previous_versions are used to set breakpoints in EMCP methods and they are
3614 // also used to clean MethodData links to redefined methods that are no longer running.
3615 void InstanceKlass::add_previous_version(instanceKlassHandle scratch_class,
3616 int emcp_method_count) {
3617 assert(Thread::current()->is_VM_thread(),
3618 "only VMThread can add previous versions");
3619
3620 ResourceMark rm;
3621 log_trace(redefine, class, iklass, add)
3622 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3623
3624 // Clean out old previous versions for this class
3625 purge_previous_version_list();
3626
3627 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
3628 // a previous redefinition may be made obsolete by this redefinition.
3629 Array<Method*>* old_methods = scratch_class->methods();
3630 mark_newly_obsolete_methods(old_methods, emcp_method_count);
3631
3632 // If the constant pool for this previous version of the class
3633 // is not marked as being on the stack, then none of the methods
3634 // in this previous version of the class are on the stack so
3635 // we don't need to add this as a previous version.
3636 ConstantPool* cp_ref = scratch_class->constants();
3637 if (!cp_ref->on_stack()) {
3638 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3639 // For debugging purposes.
3640 scratch_class->set_is_scratch_class();
3641 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class());
3642 return;
3643 }
3644
3645 if (emcp_method_count != 0) {
3646 // At least one method is still running, check for EMCP methods
3647 for (int i = 0; i < old_methods->length(); i++) {
3648 Method* old_method = old_methods->at(i);
3649 if (!old_method->is_obsolete() && old_method->on_stack()) {
3650 // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3651 // we can add breakpoints for it.
3652
3653 // We set the method->on_stack bit during safepoints for class redefinition
3654 // and use this bit to set the is_running_emcp bit.
3655 // After the safepoint, the on_stack bit is cleared and the running emcp
3656 // method may exit. If so, we would set a breakpoint in a method that
3657 // is never reached, but this won't be noticeable to the programmer.
3658 old_method->set_running_emcp(true);
3659 log_trace(redefine, class, iklass, add)
3660 ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3661 } else if (!old_method->is_obsolete()) {
3662 log_trace(redefine, class, iklass, add)
3663 ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3664 }
3665 }
3666 }
3667
3668 // Add previous version if any methods are still running.
3669 // Set has_previous_version flag for processing during class unloading.
3670 _has_previous_versions = true;
3671 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3672 assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3673 scratch_class->link_previous_versions(previous_versions());
3674 link_previous_versions(scratch_class());
3675 } // end add_previous_version()
3676
3677 #endif // INCLUDE_JVMTI
3678
3679 Method* InstanceKlass::method_with_idnum(int idnum) {
3680 Method* m = NULL;
3681 if (idnum < methods()->length()) {
3682 m = methods()->at(idnum);
3683 }
3684 if (m == NULL || m->method_idnum() != idnum) {
3685 for (int index = 0; index < methods()->length(); ++index) {
3686 m = methods()->at(index);
3687 if (m->method_idnum() == idnum) {
3688 return m;
3689 }
3690 }
3691 // None found, return null for the caller to handle.
3692 return NULL;
3693 }
3694 return m;
3695 }
3696
3697
3698 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3699 if (idnum >= methods()->length()) {
3700 return NULL;
3701 }
3702 Method* m = methods()->at(idnum);
3703 if (m != NULL && m->orig_method_idnum() == idnum) {
3704 return m;
3705 }
3706 // Obsolete method idnum does not match the original idnum
3707 for (int index = 0; index < methods()->length(); ++index) {
3708 m = methods()->at(index);
3709 if (m->orig_method_idnum() == idnum) {
3710 return m;
3711 }
3712 }
3713 // None found, return null for the caller to handle.
3714 return NULL;
3715 }
3716
3717
3718 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3719 InstanceKlass* holder = get_klass_version(version);
3720 if (holder == NULL) {
3721 return NULL; // The version of klass is gone, no method is found
3722 }
3723 Method* method = holder->method_with_orig_idnum(idnum);
3724 return method;
3725 }
3726
3727 #if INCLUDE_JVMTI
3728 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
3729 if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
3730 // Ignore the archived class stream data
3731 return NULL;
3732 } else {
3733 return _cached_class_file;
3734 }
3735 }
3736
3737 jint InstanceKlass::get_cached_class_file_len() {
3738 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3739 }
3740
3741 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3742 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3743 }
3744
3745 #if INCLUDE_CDS
3746 JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() {
3747 assert(this->is_shared(), "class should be shared");
3748 if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
3749 return _cached_class_file;
3750 } else {
3751 return NULL;
3752 }
3753 }
3754 #endif
3755 #endif