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