1 /*
2 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/javaClasses.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/verifier.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/dependencyContext.hpp"
31 #include "compiler/compileBroker.hpp"
32 #include "gc/shared/collectedHeap.inline.hpp"
33 #include "gc/shared/specialized_oop_closures.hpp"
34 #include "interpreter/oopMapCache.hpp"
35 #include "interpreter/rewriter.hpp"
36 #include "jvmtifiles/jvmti.h"
37 #include "memory/heapInspection.hpp"
38 #include "memory/iterator.inline.hpp"
39 #include "memory/metadataFactory.hpp"
40 #include "memory/oopFactory.hpp"
41 #include "oops/fieldStreams.hpp"
42 #include "oops/instanceClassLoaderKlass.hpp"
43 #include "oops/instanceKlass.inline.hpp"
44 #include "oops/instanceMirrorKlass.hpp"
45 #include "oops/instanceOop.hpp"
46 #include "oops/klass.inline.hpp"
47 #include "oops/method.hpp"
48 #include "oops/oop.inline.hpp"
49 #include "oops/symbol.hpp"
50 #include "prims/jvmtiExport.hpp"
51 #include "prims/jvmtiRedefineClasses.hpp"
52 #include "prims/jvmtiRedefineClassesTrace.hpp"
53 #include "prims/jvmtiThreadState.hpp"
54 #include "prims/methodComparator.hpp"
55 #include "runtime/atomic.inline.hpp"
56 #include "runtime/fieldDescriptor.hpp"
57 #include "runtime/handles.inline.hpp"
58 #include "runtime/javaCalls.hpp"
59 #include "runtime/mutexLocker.hpp"
60 #include "runtime/orderAccess.inline.hpp"
61 #include "runtime/thread.inline.hpp"
62 #include "services/classLoadingService.hpp"
63 #include "services/threadService.hpp"
64 #include "utilities/dtrace.hpp"
65 #include "utilities/macros.hpp"
66 #ifdef COMPILER1
67 #include "c1/c1_Compiler.hpp"
68 #endif
69
70 #ifdef DTRACE_ENABLED
71
72
73 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
74 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
75 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
76 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
77 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
78 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
79 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
80 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
81 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
82 { \
83 char* data = NULL; \
84 int len = 0; \
85 Symbol* name = (clss)->name(); \
86 if (name != NULL) { \
87 data = (char*)name->bytes(); \
88 len = name->utf8_length(); \
89 } \
90 HOTSPOT_CLASS_INITIALIZATION_##type( \
91 data, len, (clss)->class_loader(), thread_type); \
92 }
93
94 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
95 { \
96 char* data = NULL; \
97 int len = 0; \
98 Symbol* name = (clss)->name(); \
99 if (name != NULL) { \
100 data = (char*)name->bytes(); \
101 len = name->utf8_length(); \
102 } \
103 HOTSPOT_CLASS_INITIALIZATION_##type( \
104 data, len, (clss)->class_loader(), thread_type, wait); \
105 }
106
107 #else // ndef DTRACE_ENABLED
108
109 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
110 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
111
112 #endif // ndef DTRACE_ENABLED
113
114 volatile int InstanceKlass::_total_instanceKlass_count = 0;
115
116 InstanceKlass* InstanceKlass::allocate_instance_klass(
117 ClassLoaderData* loader_data,
118 int vtable_len,
119 int itable_len,
120 int static_field_size,
121 int nonstatic_oop_map_size,
122 ReferenceType rt,
123 AccessFlags access_flags,
124 Symbol* name,
125 Klass* super_klass,
126 bool is_anonymous,
127 TRAPS) {
128
129 int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
130 access_flags.is_interface(), is_anonymous);
131
132 // Allocation
133 InstanceKlass* ik;
134 if (rt == REF_NONE) {
135 if (name == vmSymbols::java_lang_Class()) {
136 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
137 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
138 access_flags, is_anonymous);
139 } else if (name == vmSymbols::java_lang_ClassLoader() ||
140 (SystemDictionary::ClassLoader_klass_loaded() &&
141 super_klass != NULL &&
142 super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
143 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
144 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
145 access_flags, is_anonymous);
146 } else {
147 // normal class
148 ik = new (loader_data, size, THREAD) InstanceKlass(
149 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size,
150 InstanceKlass::_misc_kind_other, rt, access_flags, is_anonymous);
151 }
152 } else {
153 // reference klass
154 ik = new (loader_data, size, THREAD) InstanceRefKlass(
155 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
156 access_flags, is_anonymous);
157 }
158
159 // Check for pending exception before adding to the loader data and incrementing
160 // class count. Can get OOM here.
161 if (HAS_PENDING_EXCEPTION) {
162 return NULL;
163 }
164
165 // Add all classes to our internal class loader list here,
166 // including classes in the bootstrap (NULL) class loader.
167 loader_data->add_class(ik);
168
169 Atomic::inc(&_total_instanceKlass_count);
170 return ik;
171 }
172
173
174 // copy method ordering from resource area to Metaspace
175 void InstanceKlass::copy_method_ordering(intArray* m, TRAPS) {
176 if (m != NULL) {
177 // allocate a new array and copy contents (memcpy?)
178 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
179 for (int i = 0; i < m->length(); i++) {
180 _method_ordering->at_put(i, m->at(i));
181 }
182 } else {
183 _method_ordering = Universe::the_empty_int_array();
184 }
185 }
186
187 // create a new array of vtable_indices for default methods
188 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
189 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
190 assert(default_vtable_indices() == NULL, "only create once");
191 set_default_vtable_indices(vtable_indices);
192 return vtable_indices;
193 }
194
195 InstanceKlass::InstanceKlass(int vtable_len,
196 int itable_len,
197 int static_field_size,
198 int nonstatic_oop_map_size,
199 unsigned kind,
200 ReferenceType rt,
201 AccessFlags access_flags,
202 bool is_anonymous) {
203 No_Safepoint_Verifier no_safepoint; // until k becomes parsable
204
205 int iksize = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
206 access_flags.is_interface(), is_anonymous);
207 set_vtable_length(vtable_len);
208 set_itable_length(itable_len);
209 set_static_field_size(static_field_size);
210 set_nonstatic_oop_map_size(nonstatic_oop_map_size);
211 set_access_flags(access_flags);
212 _misc_flags = 0; // initialize to zero
213 set_kind(kind);
214 set_is_anonymous(is_anonymous);
215 assert(size() == iksize, "wrong size for object");
216
217 set_array_klasses(NULL);
218 set_methods(NULL);
219 set_method_ordering(NULL);
220 set_default_methods(NULL);
221 set_default_vtable_indices(NULL);
222 set_local_interfaces(NULL);
223 set_transitive_interfaces(NULL);
224 init_implementor();
225 set_fields(NULL, 0);
226 set_constants(NULL);
227 set_class_loader_data(NULL);
228 set_source_file_name_index(0);
229 set_source_debug_extension(NULL, 0);
230 set_array_name(NULL);
231 set_inner_classes(NULL);
232 set_static_oop_field_count(0);
233 set_nonstatic_field_size(0);
234 set_is_marked_dependent(false);
235 _dep_context = DependencyContext::EMPTY;
236 set_init_state(InstanceKlass::allocated);
237 set_init_thread(NULL);
238 set_reference_type(rt);
239 set_oop_map_cache(NULL);
240 set_jni_ids(NULL);
241 set_osr_nmethods_head(NULL);
242 set_breakpoints(NULL);
243 init_previous_versions();
244 set_generic_signature_index(0);
245 release_set_methods_jmethod_ids(NULL);
246 set_annotations(NULL);
247 set_jvmti_cached_class_field_map(NULL);
248 set_initial_method_idnum(0);
249 set_jvmti_cached_class_field_map(NULL);
250 set_cached_class_file(NULL);
251 set_initial_method_idnum(0);
252 set_minor_version(0);
253 set_major_version(0);
254 NOT_PRODUCT(_verify_count = 0;)
255
256 // initialize the non-header words to zero
257 intptr_t* p = (intptr_t*)this;
258 for (int index = InstanceKlass::header_size(); index < iksize; index++) {
259 p[index] = NULL_WORD;
260 }
261
262 // Set temporary value until parseClassFile updates it with the real instance
263 // size.
264 set_layout_helper(Klass::instance_layout_helper(0, true));
265 }
266
267
268 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
269 Array<Method*>* methods) {
270 if (methods != NULL && methods != Universe::the_empty_method_array() &&
271 !methods->is_shared()) {
272 for (int i = 0; i < methods->length(); i++) {
273 Method* method = methods->at(i);
274 if (method == NULL) continue; // maybe null if error processing
275 // Only want to delete methods that are not executing for RedefineClasses.
276 // The previous version will point to them so they're not totally dangling
277 assert (!method->on_stack(), "shouldn't be called with methods on stack");
278 MetadataFactory::free_metadata(loader_data, method);
279 }
280 MetadataFactory::free_array<Method*>(loader_data, methods);
281 }
282 }
283
284 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
285 Klass* super_klass,
286 Array<Klass*>* local_interfaces,
287 Array<Klass*>* transitive_interfaces) {
288 // Only deallocate transitive interfaces if not empty, same as super class
289 // or same as local interfaces. See code in parseClassFile.
290 Array<Klass*>* ti = transitive_interfaces;
291 if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
292 // check that the interfaces don't come from super class
293 Array<Klass*>* sti = (super_klass == NULL) ? NULL :
294 InstanceKlass::cast(super_klass)->transitive_interfaces();
295 if (ti != sti && ti != NULL && !ti->is_shared()) {
296 MetadataFactory::free_array<Klass*>(loader_data, ti);
297 }
298 }
299
300 // local interfaces can be empty
301 if (local_interfaces != Universe::the_empty_klass_array() &&
302 local_interfaces != NULL && !local_interfaces->is_shared()) {
303 MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
304 }
305 }
306
307 // This function deallocates the metadata and C heap pointers that the
308 // InstanceKlass points to.
309 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
310
311 // Orphan the mirror first, CMS thinks it's still live.
312 if (java_mirror() != NULL) {
313 java_lang_Class::set_klass(java_mirror(), NULL);
314 }
315
316 // Need to take this class off the class loader data list.
317 loader_data->remove_class(this);
318
319 // The array_klass for this class is created later, after error handling.
320 // For class redefinition, we keep the original class so this scratch class
321 // doesn't have an array class. Either way, assert that there is nothing
322 // to deallocate.
323 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
324
325 // Release C heap allocated data that this might point to, which includes
326 // reference counting symbol names.
327 release_C_heap_structures();
328
329 deallocate_methods(loader_data, methods());
330 set_methods(NULL);
331
332 if (method_ordering() != NULL &&
333 method_ordering() != Universe::the_empty_int_array() &&
334 !method_ordering()->is_shared()) {
335 MetadataFactory::free_array<int>(loader_data, method_ordering());
336 }
337 set_method_ordering(NULL);
338
339 // default methods can be empty
340 if (default_methods() != NULL &&
341 default_methods() != Universe::the_empty_method_array() &&
342 !default_methods()->is_shared()) {
343 MetadataFactory::free_array<Method*>(loader_data, default_methods());
344 }
345 // Do NOT deallocate the default methods, they are owned by superinterfaces.
346 set_default_methods(NULL);
347
348 // default methods vtable indices can be empty
349 if (default_vtable_indices() != NULL &&
350 !default_vtable_indices()->is_shared()) {
351 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
352 }
353 set_default_vtable_indices(NULL);
354
355
356 // This array is in Klass, but remove it with the InstanceKlass since
357 // this place would be the only caller and it can share memory with transitive
358 // interfaces.
359 if (secondary_supers() != NULL &&
360 secondary_supers() != Universe::the_empty_klass_array() &&
361 secondary_supers() != transitive_interfaces() &&
362 !secondary_supers()->is_shared()) {
363 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
364 }
365 set_secondary_supers(NULL);
366
367 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
368 set_transitive_interfaces(NULL);
369 set_local_interfaces(NULL);
370
371 if (fields() != NULL && !fields()->is_shared()) {
372 MetadataFactory::free_array<jushort>(loader_data, fields());
373 }
374 set_fields(NULL, 0);
375
376 // If a method from a redefined class is using this constant pool, don't
377 // delete it, yet. The new class's previous version will point to this.
378 if (constants() != NULL) {
379 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
380 if (!constants()->is_shared()) {
381 MetadataFactory::free_metadata(loader_data, constants());
382 }
383 // Delete any cached resolution errors for the constant pool
384 SystemDictionary::delete_resolution_error(constants());
385
386 set_constants(NULL);
387 }
388
389 if (inner_classes() != NULL &&
390 inner_classes() != Universe::the_empty_short_array() &&
391 !inner_classes()->is_shared()) {
392 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
393 }
394 set_inner_classes(NULL);
395
396 // We should deallocate the Annotations instance if it's not in shared spaces.
397 if (annotations() != NULL && !annotations()->is_shared()) {
398 MetadataFactory::free_metadata(loader_data, annotations());
399 }
400 set_annotations(NULL);
401 }
402
403 bool InstanceKlass::should_be_initialized() const {
404 return !is_initialized();
405 }
406
407 klassVtable* InstanceKlass::vtable() const {
408 return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
409 }
410
411 klassItable* InstanceKlass::itable() const {
412 return new klassItable(instanceKlassHandle(this));
413 }
414
415 void InstanceKlass::eager_initialize(Thread *thread) {
416 if (!EagerInitialization) return;
417
418 if (this->is_not_initialized()) {
419 // abort if the the class has a class initializer
420 if (this->class_initializer() != NULL) return;
421
422 // abort if it is java.lang.Object (initialization is handled in genesis)
423 Klass* super = this->super();
424 if (super == NULL) return;
425
426 // abort if the super class should be initialized
427 if (!InstanceKlass::cast(super)->is_initialized()) return;
428
429 // call body to expose the this pointer
430 instanceKlassHandle this_k(thread, this);
431 eager_initialize_impl(this_k);
432 }
433 }
434
435 // JVMTI spec thinks there are signers and protection domain in the
436 // instanceKlass. These accessors pretend these fields are there.
437 // The hprof specification also thinks these fields are in InstanceKlass.
438 oop InstanceKlass::protection_domain() const {
439 // return the protection_domain from the mirror
440 return java_lang_Class::protection_domain(java_mirror());
441 }
442
443 // To remove these from requires an incompatible change and CCC request.
444 objArrayOop InstanceKlass::signers() const {
445 // return the signers from the mirror
446 return java_lang_Class::signers(java_mirror());
447 }
448
449 oop InstanceKlass::init_lock() const {
450 // return the init lock from the mirror
451 oop lock = java_lang_Class::init_lock(java_mirror());
452 // Prevent reordering with any access of initialization state
453 OrderAccess::loadload();
454 assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
455 "only fully initialized state can have a null lock");
456 return lock;
457 }
458
459 // Set the initialization lock to null so the object can be GC'ed. Any racing
460 // threads to get this lock will see a null lock and will not lock.
461 // That's okay because they all check for initialized state after getting
462 // the lock and return.
463 void InstanceKlass::fence_and_clear_init_lock() {
464 // make sure previous stores are all done, notably the init_state.
465 OrderAccess::storestore();
466 java_lang_Class::set_init_lock(java_mirror(), NULL);
467 assert(!is_not_initialized(), "class must be initialized now");
468 }
469
470 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_k) {
471 EXCEPTION_MARK;
472 oop init_lock = this_k->init_lock();
473 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
474
475 // abort if someone beat us to the initialization
476 if (!this_k->is_not_initialized()) return; // note: not equivalent to is_initialized()
477
478 ClassState old_state = this_k->init_state();
479 link_class_impl(this_k, true, THREAD);
480 if (HAS_PENDING_EXCEPTION) {
481 CLEAR_PENDING_EXCEPTION;
482 // Abort if linking the class throws an exception.
483
484 // Use a test to avoid redundantly resetting the state if there's
485 // no change. Set_init_state() asserts that state changes make
486 // progress, whereas here we might just be spinning in place.
487 if( old_state != this_k->_init_state )
488 this_k->set_init_state (old_state);
489 } else {
490 // linking successfull, mark class as initialized
491 this_k->set_init_state (fully_initialized);
492 this_k->fence_and_clear_init_lock();
493 // trace
494 if (TraceClassInitialization) {
495 ResourceMark rm(THREAD);
496 tty->print_cr("[Initialized %s without side effects]", this_k->external_name());
497 }
498 }
499 }
500
501
502 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
503 // process. The step comments refers to the procedure described in that section.
504 // Note: implementation moved to static method to expose the this pointer.
505 void InstanceKlass::initialize(TRAPS) {
506 if (this->should_be_initialized()) {
507 HandleMark hm(THREAD);
508 instanceKlassHandle this_k(THREAD, this);
509 initialize_impl(this_k, CHECK);
510 // Note: at this point the class may be initialized
511 // OR it may be in the state of being initialized
512 // in case of recursive initialization!
513 } else {
514 assert(is_initialized(), "sanity check");
515 }
516 }
517
518
519 bool InstanceKlass::verify_code(
520 instanceKlassHandle this_k, bool throw_verifyerror, TRAPS) {
521 // 1) Verify the bytecodes
522 Verifier::Mode mode =
523 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
524 return Verifier::verify(this_k, mode, this_k->should_verify_class(), THREAD);
525 }
526
527
528 // Used exclusively by the shared spaces dump mechanism to prevent
529 // classes mapped into the shared regions in new VMs from appearing linked.
530
531 void InstanceKlass::unlink_class() {
532 assert(is_linked(), "must be linked");
533 _init_state = loaded;
534 }
535
536 void InstanceKlass::link_class(TRAPS) {
537 assert(is_loaded(), "must be loaded");
538 if (!is_linked()) {
539 HandleMark hm(THREAD);
540 instanceKlassHandle this_k(THREAD, this);
541 link_class_impl(this_k, true, CHECK);
542 }
543 }
544
545 // Called to verify that a class can link during initialization, without
546 // throwing a VerifyError.
547 bool InstanceKlass::link_class_or_fail(TRAPS) {
548 assert(is_loaded(), "must be loaded");
549 if (!is_linked()) {
550 HandleMark hm(THREAD);
551 instanceKlassHandle this_k(THREAD, this);
552 link_class_impl(this_k, false, CHECK_false);
553 }
554 return is_linked();
555 }
556
557 bool InstanceKlass::link_class_impl(
558 instanceKlassHandle this_k, bool throw_verifyerror, TRAPS) {
559 // check for error state
560 if (this_k->is_in_error_state()) {
561 ResourceMark rm(THREAD);
562 THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
563 this_k->external_name(), false);
564 }
565 // return if already verified
566 if (this_k->is_linked()) {
567 return true;
568 }
569
570 // Timing
571 // timer handles recursion
572 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
573 JavaThread* jt = (JavaThread*)THREAD;
574
575 // link super class before linking this class
576 instanceKlassHandle super(THREAD, this_k->super());
577 if (super.not_null()) {
578 if (super->is_interface()) { // check if super class is an interface
579 ResourceMark rm(THREAD);
580 Exceptions::fthrow(
581 THREAD_AND_LOCATION,
582 vmSymbols::java_lang_IncompatibleClassChangeError(),
583 "class %s has interface %s as super class",
584 this_k->external_name(),
585 super->external_name()
586 );
587 return false;
588 }
589
590 link_class_impl(super, throw_verifyerror, CHECK_false);
591 }
592
593 // link all interfaces implemented by this class before linking this class
594 Array<Klass*>* interfaces = this_k->local_interfaces();
595 int num_interfaces = interfaces->length();
596 for (int index = 0; index < num_interfaces; index++) {
597 HandleMark hm(THREAD);
598 instanceKlassHandle ih(THREAD, interfaces->at(index));
599 link_class_impl(ih, throw_verifyerror, CHECK_false);
600 }
601
602 // in case the class is linked in the process of linking its superclasses
603 if (this_k->is_linked()) {
604 return true;
605 }
606
607 // trace only the link time for this klass that includes
608 // the verification time
609 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
610 ClassLoader::perf_class_link_selftime(),
611 ClassLoader::perf_classes_linked(),
612 jt->get_thread_stat()->perf_recursion_counts_addr(),
613 jt->get_thread_stat()->perf_timers_addr(),
614 PerfClassTraceTime::CLASS_LINK);
615
616 // verification & rewriting
617 {
618 oop init_lock = this_k->init_lock();
619 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
620 // rewritten will have been set if loader constraint error found
621 // on an earlier link attempt
622 // don't verify or rewrite if already rewritten
623
624 if (!this_k->is_linked()) {
625 if (!this_k->is_rewritten()) {
626 {
627 bool verify_ok = verify_code(this_k, throw_verifyerror, THREAD);
628 if (!verify_ok) {
629 return false;
630 }
631 }
632
633 // Just in case a side-effect of verify linked this class already
634 // (which can sometimes happen since the verifier loads classes
635 // using custom class loaders, which are free to initialize things)
636 if (this_k->is_linked()) {
637 return true;
638 }
639
640 // also sets rewritten
641 this_k->rewrite_class(CHECK_false);
642 }
643
644 // relocate jsrs and link methods after they are all rewritten
645 this_k->link_methods(CHECK_false);
646
647 // Initialize the vtable and interface table after
648 // methods have been rewritten since rewrite may
649 // fabricate new Method*s.
650 // also does loader constraint checking
651 if (!this_k()->is_shared()) {
652 ResourceMark rm(THREAD);
653 this_k->vtable()->initialize_vtable(true, CHECK_false);
654 this_k->itable()->initialize_itable(true, CHECK_false);
655 }
656 #ifdef ASSERT
657 else {
658 ResourceMark rm(THREAD);
659 this_k->vtable()->verify(tty, true);
660 // In case itable verification is ever added.
661 // this_k->itable()->verify(tty, true);
662 }
663 #endif
664 this_k->set_init_state(linked);
665 if (JvmtiExport::should_post_class_prepare()) {
666 Thread *thread = THREAD;
667 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
668 JvmtiExport::post_class_prepare((JavaThread *) thread, this_k());
669 }
670 }
671 }
672 return true;
673 }
674
675
676 // Rewrite the byte codes of all of the methods of a class.
677 // The rewriter must be called exactly once. Rewriting must happen after
678 // verification but before the first method of the class is executed.
679 void InstanceKlass::rewrite_class(TRAPS) {
680 assert(is_loaded(), "must be loaded");
681 instanceKlassHandle this_k(THREAD, this);
682 if (this_k->is_rewritten()) {
683 assert(this_k()->is_shared(), "rewriting an unshared class?");
684 return;
685 }
686 Rewriter::rewrite(this_k, CHECK);
687 this_k->set_rewritten();
688 }
689
690 // Now relocate and link method entry points after class is rewritten.
691 // This is outside is_rewritten flag. In case of an exception, it can be
692 // executed more than once.
693 void InstanceKlass::link_methods(TRAPS) {
694 int len = methods()->length();
695 for (int i = len-1; i >= 0; i--) {
696 methodHandle m(THREAD, methods()->at(i));
697
698 // Set up method entry points for compiler and interpreter .
699 m->link_method(m, CHECK);
700 }
701 }
702
703 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
704 void InstanceKlass::initialize_super_interfaces(instanceKlassHandle this_k, TRAPS) {
705 if (this_k->has_default_methods()) {
706 for (int i = 0; i < this_k->local_interfaces()->length(); ++i) {
707 Klass* iface = this_k->local_interfaces()->at(i);
708 InstanceKlass* ik = InstanceKlass::cast(iface);
709 if (ik->should_be_initialized()) {
710 if (ik->has_default_methods()) {
711 ik->initialize_super_interfaces(ik, THREAD);
712 }
713 // Only initialize() interfaces that "declare" concrete methods.
714 // has_default_methods drives searching superinterfaces since it
715 // means has_default_methods in its superinterface hierarchy
716 if (!HAS_PENDING_EXCEPTION && ik->declares_default_methods()) {
717 ik->initialize(THREAD);
718 }
719 if (HAS_PENDING_EXCEPTION) {
720 Handle e(THREAD, PENDING_EXCEPTION);
721 CLEAR_PENDING_EXCEPTION;
722 {
723 EXCEPTION_MARK;
724 // Locks object, set state, and notify all waiting threads
725 this_k->set_initialization_state_and_notify(
726 initialization_error, THREAD);
727
728 // ignore any exception thrown, superclass initialization error is
729 // thrown below
730 CLEAR_PENDING_EXCEPTION;
731 }
732 THROW_OOP(e());
733 }
734 }
735 }
736 }
737 }
738
739 void InstanceKlass::initialize_impl(instanceKlassHandle this_k, TRAPS) {
740 // Make sure klass is linked (verified) before initialization
741 // A class could already be verified, since it has been reflected upon.
742 this_k->link_class(CHECK);
743
744 DTRACE_CLASSINIT_PROBE(required, this_k(), -1);
745
746 bool wait = false;
747
748 // refer to the JVM book page 47 for description of steps
749 // Step 1
750 {
751 oop init_lock = this_k->init_lock();
752 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
753
754 Thread *self = THREAD; // it's passed the current thread
755
756 // Step 2
757 // If we were to use wait() instead of waitInterruptibly() then
758 // we might end up throwing IE from link/symbol resolution sites
759 // that aren't expected to throw. This would wreak havoc. See 6320309.
760 while(this_k->is_being_initialized() && !this_k->is_reentrant_initialization(self)) {
761 wait = true;
762 ol.waitUninterruptibly(CHECK);
763 }
764
765 // Step 3
766 if (this_k->is_being_initialized() && this_k->is_reentrant_initialization(self)) {
767 DTRACE_CLASSINIT_PROBE_WAIT(recursive, this_k(), -1,wait);
768 return;
769 }
770
771 // Step 4
772 if (this_k->is_initialized()) {
773 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, this_k(), -1,wait);
774 return;
775 }
776
777 // Step 5
778 if (this_k->is_in_error_state()) {
779 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, this_k(), -1,wait);
780 ResourceMark rm(THREAD);
781 const char* desc = "Could not initialize class ";
782 const char* className = this_k->external_name();
783 size_t msglen = strlen(desc) + strlen(className) + 1;
784 char* message = NEW_RESOURCE_ARRAY(char, msglen);
785 if (NULL == message) {
786 // Out of memory: can't create detailed error message
787 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
788 } else {
789 jio_snprintf(message, msglen, "%s%s", desc, className);
790 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
791 }
792 }
793
794 // Step 6
795 this_k->set_init_state(being_initialized);
796 this_k->set_init_thread(self);
797 }
798
799 // Step 7
800 Klass* super_klass = this_k->super();
801 if (super_klass != NULL && !this_k->is_interface() && super_klass->should_be_initialized()) {
802 super_klass->initialize(THREAD);
803
804 if (HAS_PENDING_EXCEPTION) {
805 Handle e(THREAD, PENDING_EXCEPTION);
806 CLEAR_PENDING_EXCEPTION;
807 {
808 EXCEPTION_MARK;
809 this_k->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
810 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, superclass initialization error is thrown below
811 }
812 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, this_k(), -1,wait);
813 THROW_OOP(e());
814 }
815 }
816
817 // Recursively initialize any superinterfaces that declare default methods
818 // Only need to recurse if has_default_methods which includes declaring and
819 // inheriting default methods
820 if (this_k->has_default_methods()) {
821 this_k->initialize_super_interfaces(this_k, CHECK);
822 }
823
824 // Step 8
825 {
826 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
827 JavaThread* jt = (JavaThread*)THREAD;
828 DTRACE_CLASSINIT_PROBE_WAIT(clinit, this_k(), -1,wait);
829 // Timer includes any side effects of class initialization (resolution,
830 // etc), but not recursive entry into call_class_initializer().
831 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
832 ClassLoader::perf_class_init_selftime(),
833 ClassLoader::perf_classes_inited(),
834 jt->get_thread_stat()->perf_recursion_counts_addr(),
835 jt->get_thread_stat()->perf_timers_addr(),
836 PerfClassTraceTime::CLASS_CLINIT);
837 this_k->call_class_initializer(THREAD);
838 }
839
840 // Step 9
841 if (!HAS_PENDING_EXCEPTION) {
842 this_k->set_initialization_state_and_notify(fully_initialized, CHECK);
843 { ResourceMark rm(THREAD);
844 debug_only(this_k->vtable()->verify(tty, true);)
845 }
846 }
847 else {
848 // Step 10 and 11
849 Handle e(THREAD, PENDING_EXCEPTION);
850 CLEAR_PENDING_EXCEPTION;
851 // JVMTI has already reported the pending exception
852 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
853 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
854 {
855 EXCEPTION_MARK;
856 this_k->set_initialization_state_and_notify(initialization_error, THREAD);
857 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
858 // JVMTI has already reported the pending exception
859 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
860 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
861 }
862 DTRACE_CLASSINIT_PROBE_WAIT(error, this_k(), -1,wait);
863 if (e->is_a(SystemDictionary::Error_klass())) {
864 THROW_OOP(e());
865 } else {
866 JavaCallArguments args(e);
867 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
868 vmSymbols::throwable_void_signature(),
869 &args);
870 }
871 }
872 DTRACE_CLASSINIT_PROBE_WAIT(end, this_k(), -1,wait);
873 }
874
875
876 // Note: implementation moved to static method to expose the this pointer.
877 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
878 instanceKlassHandle kh(THREAD, this);
879 set_initialization_state_and_notify_impl(kh, state, CHECK);
880 }
881
882 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_k, ClassState state, TRAPS) {
883 oop init_lock = this_k->init_lock();
884 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
885 this_k->set_init_state(state);
886 this_k->fence_and_clear_init_lock();
887 ol.notify_all(CHECK);
888 }
889
890 // The embedded _implementor field can only record one implementor.
891 // When there are more than one implementors, the _implementor field
892 // is set to the interface Klass* itself. Following are the possible
893 // values for the _implementor field:
894 // NULL - no implementor
895 // implementor Klass* - one implementor
896 // self - more than one implementor
897 //
898 // The _implementor field only exists for interfaces.
899 void InstanceKlass::add_implementor(Klass* k) {
900 assert(Compile_lock->owned_by_self(), "");
901 assert(is_interface(), "not interface");
902 // Filter out my subinterfaces.
903 // (Note: Interfaces are never on the subklass list.)
904 if (InstanceKlass::cast(k)->is_interface()) return;
905
906 // Filter out subclasses whose supers already implement me.
907 // (Note: CHA must walk subclasses of direct implementors
908 // in order to locate indirect implementors.)
909 Klass* sk = k->super();
910 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
911 // We only need to check one immediate superclass, since the
912 // implements_interface query looks at transitive_interfaces.
913 // Any supers of the super have the same (or fewer) transitive_interfaces.
914 return;
915
916 Klass* ik = implementor();
917 if (ik == NULL) {
918 set_implementor(k);
919 } else if (ik != this) {
920 // There is already an implementor. Use itself as an indicator of
921 // more than one implementors.
922 set_implementor(this);
923 }
924
925 // The implementor also implements the transitive_interfaces
926 for (int index = 0; index < local_interfaces()->length(); index++) {
927 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
928 }
929 }
930
931 void InstanceKlass::init_implementor() {
932 if (is_interface()) {
933 set_implementor(NULL);
934 }
935 }
936
937
938 void InstanceKlass::process_interfaces(Thread *thread) {
939 // link this class into the implementors list of every interface it implements
940 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
941 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
942 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
943 assert(interf->is_interface(), "expected interface");
944 interf->add_implementor(this);
945 }
946 }
947
948 bool InstanceKlass::can_be_primary_super_slow() const {
949 if (is_interface())
950 return false;
951 else
952 return Klass::can_be_primary_super_slow();
953 }
954
955 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
956 // The secondaries are the implemented interfaces.
957 Array<Klass*>* interfaces = transitive_interfaces();
958 int num_secondaries = num_extra_slots + interfaces->length();
959 if (num_secondaries == 0) {
960 // Must share this for correct bootstrapping!
961 set_secondary_supers(Universe::the_empty_klass_array());
962 return NULL;
963 } else if (num_extra_slots == 0) {
964 // The secondary super list is exactly the same as the transitive interfaces.
965 // Redefine classes has to be careful not to delete this!
966 set_secondary_supers(interfaces);
967 return NULL;
968 } else {
969 // Copy transitive interfaces to a temporary growable array to be constructed
970 // into the secondary super list with extra slots.
971 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
972 for (int i = 0; i < interfaces->length(); i++) {
973 secondaries->push(interfaces->at(i));
974 }
975 return secondaries;
976 }
977 }
978
979 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
980 if (k->is_interface()) {
981 return implements_interface(k);
982 } else {
983 return Klass::compute_is_subtype_of(k);
984 }
985 }
986
987 bool InstanceKlass::implements_interface(Klass* k) const {
988 if (this == k) return true;
989 assert(k->is_interface(), "should be an interface class");
990 for (int i = 0; i < transitive_interfaces()->length(); i++) {
991 if (transitive_interfaces()->at(i) == k) {
992 return true;
993 }
994 }
995 return false;
996 }
997
998 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
999 // Verify direct super interface
1000 if (this == k) return true;
1001 assert(k->is_interface(), "should be an interface class");
1002 for (int i = 0; i < local_interfaces()->length(); i++) {
1003 if (local_interfaces()->at(i) == k) {
1004 return true;
1005 }
1006 }
1007 return false;
1008 }
1009
1010 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1011 if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
1012 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
1013 report_java_out_of_memory("Requested array size exceeds VM limit");
1014 JvmtiExport::post_array_size_exhausted();
1015 THROW_OOP_0(Universe::out_of_memory_error_array_size());
1016 }
1017 int size = objArrayOopDesc::object_size(length);
1018 Klass* ak = array_klass(n, CHECK_NULL);
1019 KlassHandle h_ak (THREAD, ak);
1020 objArrayOop o =
1021 (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
1022 return o;
1023 }
1024
1025 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1026 if (TraceFinalizerRegistration) {
1027 tty->print("Registered ");
1028 i->print_value_on(tty);
1029 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1030 }
1031 instanceHandle h_i(THREAD, i);
1032 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1033 JavaValue result(T_VOID);
1034 JavaCallArguments args(h_i);
1035 methodHandle mh (THREAD, Universe::finalizer_register_method());
1036 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1037 return h_i();
1038 }
1039
1040 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1041 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1042 int size = size_helper(); // Query before forming handle.
1043
1044 KlassHandle h_k(THREAD, this);
1045
1046 instanceOop i;
1047
1048 i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
1049 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1050 i = register_finalizer(i, CHECK_NULL);
1051 }
1052 return i;
1053 }
1054
1055 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1056 if (is_interface() || is_abstract()) {
1057 ResourceMark rm(THREAD);
1058 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1059 : vmSymbols::java_lang_InstantiationException(), external_name());
1060 }
1061 if (this == SystemDictionary::Class_klass()) {
1062 ResourceMark rm(THREAD);
1063 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1064 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1065 }
1066 }
1067
1068 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1069 instanceKlassHandle this_k(THREAD, this);
1070 return array_klass_impl(this_k, or_null, n, THREAD);
1071 }
1072
1073 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_k, bool or_null, int n, TRAPS) {
1074 if (this_k->array_klasses() == NULL) {
1075 if (or_null) return NULL;
1076
1077 ResourceMark rm;
1078 JavaThread *jt = (JavaThread *)THREAD;
1079 {
1080 // Atomic creation of array_klasses
1081 MutexLocker mc(Compile_lock, THREAD); // for vtables
1082 MutexLocker ma(MultiArray_lock, THREAD);
1083
1084 // Check if update has already taken place
1085 if (this_k->array_klasses() == NULL) {
1086 Klass* k = ObjArrayKlass::allocate_objArray_klass(this_k->class_loader_data(), 1, this_k, CHECK_NULL);
1087 this_k->set_array_klasses(k);
1088 }
1089 }
1090 }
1091 // _this will always be set at this point
1092 ObjArrayKlass* oak = (ObjArrayKlass*)this_k->array_klasses();
1093 if (or_null) {
1094 return oak->array_klass_or_null(n);
1095 }
1096 return oak->array_klass(n, THREAD);
1097 }
1098
1099 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1100 return array_klass_impl(or_null, 1, THREAD);
1101 }
1102
1103 void InstanceKlass::call_class_initializer(TRAPS) {
1104 instanceKlassHandle ik (THREAD, this);
1105 call_class_initializer_impl(ik, THREAD);
1106 }
1107
1108 static int call_class_initializer_impl_counter = 0; // for debugging
1109
1110 Method* InstanceKlass::class_initializer() {
1111 Method* clinit = find_method(
1112 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1113 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1114 return clinit;
1115 }
1116 return NULL;
1117 }
1118
1119 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_k, TRAPS) {
1120 if (ReplayCompiles &&
1121 (ReplaySuppressInitializers == 1 ||
1122 ReplaySuppressInitializers >= 2 && this_k->class_loader() != NULL)) {
1123 // Hide the existence of the initializer for the purpose of replaying the compile
1124 return;
1125 }
1126
1127 methodHandle h_method(THREAD, this_k->class_initializer());
1128 assert(!this_k->is_initialized(), "we cannot initialize twice");
1129 if (TraceClassInitialization) {
1130 tty->print("%d Initializing ", call_class_initializer_impl_counter++);
1131 this_k->name()->print_value();
1132 tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this_k()));
1133 }
1134 if (h_method() != NULL) {
1135 JavaCallArguments args; // No arguments
1136 JavaValue result(T_VOID);
1137 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1138 }
1139 }
1140
1141
1142 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1143 InterpreterOopMap* entry_for) {
1144 // Dirty read, then double-check under a lock.
1145 if (_oop_map_cache == NULL) {
1146 // Otherwise, allocate a new one.
1147 MutexLocker x(OopMapCacheAlloc_lock);
1148 // First time use. Allocate a cache in C heap
1149 if (_oop_map_cache == NULL) {
1150 // Release stores from OopMapCache constructor before assignment
1151 // to _oop_map_cache. C++ compilers on ppc do not emit the
1152 // required memory barrier only because of the volatile
1153 // qualifier of _oop_map_cache.
1154 OrderAccess::release_store_ptr(&_oop_map_cache, new OopMapCache());
1155 }
1156 }
1157 // _oop_map_cache is constant after init; lookup below does is own locking.
1158 _oop_map_cache->lookup(method, bci, entry_for);
1159 }
1160
1161
1162 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1163 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1164 Symbol* f_name = fs.name();
1165 Symbol* f_sig = fs.signature();
1166 if (f_name == name && f_sig == sig) {
1167 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1168 return true;
1169 }
1170 }
1171 return false;
1172 }
1173
1174
1175 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1176 const int n = local_interfaces()->length();
1177 for (int i = 0; i < n; i++) {
1178 Klass* intf1 = local_interfaces()->at(i);
1179 assert(intf1->is_interface(), "just checking type");
1180 // search for field in current interface
1181 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1182 assert(fd->is_static(), "interface field must be static");
1183 return intf1;
1184 }
1185 // search for field in direct superinterfaces
1186 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1187 if (intf2 != NULL) return intf2;
1188 }
1189 // otherwise field lookup fails
1190 return NULL;
1191 }
1192
1193
1194 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, 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 return const_cast<InstanceKlass*>(this);
1199 }
1200 // 2) search for field recursively in direct superinterfaces
1201 { Klass* intf = find_interface_field(name, sig, fd);
1202 if (intf != NULL) return intf;
1203 }
1204 // 3) apply field lookup recursively if superclass exists
1205 { Klass* supr = super();
1206 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1207 }
1208 // 4) otherwise field lookup fails
1209 return NULL;
1210 }
1211
1212
1213 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1214 // search order according to newest JVM spec (5.4.3.2, p.167).
1215 // 1) search for field in current klass
1216 if (find_local_field(name, sig, fd)) {
1217 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1218 }
1219 // 2) search for field recursively in direct superinterfaces
1220 if (is_static) {
1221 Klass* intf = find_interface_field(name, sig, fd);
1222 if (intf != NULL) return intf;
1223 }
1224 // 3) apply field lookup recursively if superclass exists
1225 { Klass* supr = super();
1226 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1227 }
1228 // 4) otherwise field lookup fails
1229 return NULL;
1230 }
1231
1232
1233 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1234 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1235 if (fs.offset() == offset) {
1236 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1237 if (fd->is_static() == is_static) return true;
1238 }
1239 }
1240 return false;
1241 }
1242
1243
1244 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1245 Klass* klass = const_cast<InstanceKlass*>(this);
1246 while (klass != NULL) {
1247 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1248 return true;
1249 }
1250 klass = klass->super();
1251 }
1252 return false;
1253 }
1254
1255
1256 void InstanceKlass::methods_do(void f(Method* method)) {
1257 // Methods aren't stable until they are loaded. This can be read outside
1258 // a lock through the ClassLoaderData for profiling
1259 if (!is_loaded()) {
1260 return;
1261 }
1262
1263 int len = methods()->length();
1264 for (int index = 0; index < len; index++) {
1265 Method* m = methods()->at(index);
1266 assert(m->is_method(), "must be method");
1267 f(m);
1268 }
1269 }
1270
1271
1272 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1273 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1274 if (fs.access_flags().is_static()) {
1275 fieldDescriptor& fd = fs.field_descriptor();
1276 cl->do_field(&fd);
1277 }
1278 }
1279 }
1280
1281
1282 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1283 instanceKlassHandle h_this(THREAD, this);
1284 do_local_static_fields_impl(h_this, f, mirror, CHECK);
1285 }
1286
1287
1288 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_k,
1289 void f(fieldDescriptor* fd, Handle, TRAPS), Handle mirror, TRAPS) {
1290 for (JavaFieldStream fs(this_k()); !fs.done(); fs.next()) {
1291 if (fs.access_flags().is_static()) {
1292 fieldDescriptor& fd = fs.field_descriptor();
1293 f(&fd, mirror, CHECK);
1294 }
1295 }
1296 }
1297
1298
1299 static int compare_fields_by_offset(int* a, int* b) {
1300 return a[0] - b[0];
1301 }
1302
1303 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1304 InstanceKlass* super = superklass();
1305 if (super != NULL) {
1306 super->do_nonstatic_fields(cl);
1307 }
1308 fieldDescriptor fd;
1309 int length = java_fields_count();
1310 // In DebugInfo nonstatic fields are sorted by offset.
1311 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1312 int j = 0;
1313 for (int i = 0; i < length; i += 1) {
1314 fd.reinitialize(this, i);
1315 if (!fd.is_static()) {
1316 fields_sorted[j + 0] = fd.offset();
1317 fields_sorted[j + 1] = i;
1318 j += 2;
1319 }
1320 }
1321 if (j > 0) {
1322 length = j;
1323 // _sort_Fn is defined in growableArray.hpp.
1324 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1325 for (int i = 0; i < length; i += 2) {
1326 fd.reinitialize(this, fields_sorted[i + 1]);
1327 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1328 cl->do_field(&fd);
1329 }
1330 }
1331 FREE_C_HEAP_ARRAY(int, fields_sorted);
1332 }
1333
1334
1335 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1336 if (array_klasses() != NULL)
1337 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1338 }
1339
1340 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1341 if (array_klasses() != NULL)
1342 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1343 }
1344
1345 #ifdef ASSERT
1346 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
1347 int len = methods->length();
1348 for (int index = 0; index < len; index++) {
1349 Method* m = methods->at(index);
1350 assert(m->is_method(), "must be method");
1351 if (m->signature() == signature && m->name() == name) {
1352 return index;
1353 }
1354 }
1355 return -1;
1356 }
1357 #endif
1358
1359 static int binary_search(Array<Method*>* methods, Symbol* name) {
1360 int len = methods->length();
1361 // methods are sorted, so do binary search
1362 int l = 0;
1363 int h = len - 1;
1364 while (l <= h) {
1365 int mid = (l + h) >> 1;
1366 Method* m = methods->at(mid);
1367 assert(m->is_method(), "must be method");
1368 int res = m->name()->fast_compare(name);
1369 if (res == 0) {
1370 return mid;
1371 } else if (res < 0) {
1372 l = mid + 1;
1373 } else {
1374 h = mid - 1;
1375 }
1376 }
1377 return -1;
1378 }
1379
1380 // find_method looks up the name/signature in the local methods array
1381 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
1382 return find_method_impl(name, signature, find_overpass, find_static, find_private);
1383 }
1384
1385 Method* InstanceKlass::find_method_impl(Symbol* name, Symbol* signature,
1386 OverpassLookupMode overpass_mode,
1387 StaticLookupMode static_mode,
1388 PrivateLookupMode private_mode) const {
1389 return InstanceKlass::find_method_impl(methods(), name, signature, overpass_mode, static_mode, private_mode);
1390 }
1391
1392 // find_instance_method looks up the name/signature in the local methods array
1393 // and skips over static methods
1394 Method* InstanceKlass::find_instance_method(
1395 Array<Method*>* methods, Symbol* name, Symbol* signature) {
1396 Method* meth = InstanceKlass::find_method_impl(methods, name, signature,
1397 find_overpass, skip_static, find_private);
1398 assert(((meth == NULL) || !meth->is_static()), "find_instance_method should have skipped statics");
1399 return meth;
1400 }
1401
1402 // find_instance_method looks up the name/signature in the local methods array
1403 // and skips over static methods
1404 Method* InstanceKlass::find_instance_method(Symbol* name, Symbol* signature) {
1405 return InstanceKlass::find_instance_method(methods(), name, signature);
1406 }
1407
1408 // Find looks up the name/signature in the local methods array
1409 // and filters on the overpass, static and private flags
1410 // This returns the first one found
1411 // note that the local methods array can have up to one overpass, one static
1412 // and one instance (private or not) with the same name/signature
1413 Method* InstanceKlass::find_local_method(Symbol* name, Symbol* signature,
1414 OverpassLookupMode overpass_mode,
1415 StaticLookupMode static_mode,
1416 PrivateLookupMode private_mode) const {
1417 return InstanceKlass::find_method_impl(methods(), name, signature, overpass_mode, static_mode, private_mode);
1418 }
1419
1420 // Find looks up the name/signature in the local methods array
1421 // and filters on the overpass, static and private flags
1422 // This returns the first one found
1423 // note that the local methods array can have up to one overpass, one static
1424 // and one instance (private or not) with the same name/signature
1425 Method* InstanceKlass::find_local_method(Array<Method*>* methods,
1426 Symbol* name, Symbol* signature,
1427 OverpassLookupMode overpass_mode,
1428 StaticLookupMode static_mode,
1429 PrivateLookupMode private_mode) {
1430 return InstanceKlass::find_method_impl(methods, name, signature, overpass_mode, static_mode, private_mode);
1431 }
1432
1433
1434 // find_method looks up the name/signature in the local methods array
1435 Method* InstanceKlass::find_method(
1436 Array<Method*>* methods, Symbol* name, Symbol* signature) {
1437 return InstanceKlass::find_method_impl(methods, name, signature, find_overpass, find_static, find_private);
1438 }
1439
1440 Method* InstanceKlass::find_method_impl(
1441 Array<Method*>* methods, Symbol* name, Symbol* signature,
1442 OverpassLookupMode overpass_mode, StaticLookupMode static_mode,
1443 PrivateLookupMode private_mode) {
1444 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1445 return hit >= 0 ? methods->at(hit): NULL;
1446 }
1447
1448 bool InstanceKlass::method_matches(Method* m, Symbol* signature, bool skipping_overpass, bool skipping_static, bool skipping_private) {
1449 return ((m->signature() == signature) &&
1450 (!skipping_overpass || !m->is_overpass()) &&
1451 (!skipping_static || !m->is_static()) &&
1452 (!skipping_private || !m->is_private()));
1453 }
1454
1455 // Used directly for default_methods to find the index into the
1456 // default_vtable_indices, and indirectly by find_method
1457 // find_method_index looks in the local methods array to return the index
1458 // of the matching name/signature. If, overpass methods are being ignored,
1459 // the search continues to find a potential non-overpass match. This capability
1460 // is important during method resolution to prefer a static method, for example,
1461 // over an overpass method.
1462 // There is the possibility in any _method's array to have the same name/signature
1463 // for a static method, an overpass method and a local instance method
1464 // To correctly catch a given method, the search criteria may need
1465 // to explicitly skip the other two. For local instance methods, it
1466 // is often necessary to skip private methods
1467 int InstanceKlass::find_method_index(
1468 Array<Method*>* methods, Symbol* name, Symbol* signature,
1469 OverpassLookupMode overpass_mode, StaticLookupMode static_mode,
1470 PrivateLookupMode private_mode) {
1471 bool skipping_overpass = (overpass_mode == skip_overpass);
1472 bool skipping_static = (static_mode == skip_static);
1473 bool skipping_private = (private_mode == skip_private);
1474 int hit = binary_search(methods, name);
1475 if (hit != -1) {
1476 Method* m = methods->at(hit);
1477
1478 // Do linear search to find matching signature. First, quick check
1479 // for common case, ignoring overpasses if requested.
1480 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) return hit;
1481
1482 // search downwards through overloaded methods
1483 int i;
1484 for (i = hit - 1; i >= 0; --i) {
1485 Method* m = methods->at(i);
1486 assert(m->is_method(), "must be method");
1487 if (m->name() != name) break;
1488 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) return i;
1489 }
1490 // search upwards
1491 for (i = hit + 1; i < methods->length(); ++i) {
1492 Method* m = methods->at(i);
1493 assert(m->is_method(), "must be method");
1494 if (m->name() != name) break;
1495 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) return i;
1496 }
1497 // not found
1498 #ifdef ASSERT
1499 int index = (skipping_overpass || skipping_static || skipping_private) ? -1 : linear_search(methods, name, signature);
1500 assert(index == -1, "binary search should have found entry %d", index);
1501 #endif
1502 }
1503 return -1;
1504 }
1505 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
1506 return find_method_by_name(methods(), name, end);
1507 }
1508
1509 int InstanceKlass::find_method_by_name(
1510 Array<Method*>* methods, Symbol* name, int* end_ptr) {
1511 assert(end_ptr != NULL, "just checking");
1512 int start = binary_search(methods, name);
1513 int end = start + 1;
1514 if (start != -1) {
1515 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1516 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1517 *end_ptr = end;
1518 return start;
1519 }
1520 return -1;
1521 }
1522
1523 // uncached_lookup_method searches both the local class methods array and all
1524 // superclasses methods arrays, skipping any overpass methods in superclasses.
1525 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature, OverpassLookupMode overpass_mode) const {
1526 OverpassLookupMode overpass_local_mode = overpass_mode;
1527 Klass* klass = const_cast<InstanceKlass*>(this);
1528 while (klass != NULL) {
1529 Method* method = InstanceKlass::cast(klass)->find_method_impl(name, signature, overpass_local_mode, find_static, find_private);
1530 if (method != NULL) {
1531 return method;
1532 }
1533 klass = klass->super();
1534 overpass_local_mode = skip_overpass; // Always ignore overpass methods in superclasses
1535 }
1536 return NULL;
1537 }
1538
1539 #ifdef ASSERT
1540 // search through class hierarchy and return true if this class or
1541 // one of the superclasses was redefined
1542 bool InstanceKlass::has_redefined_this_or_super() {
1543 Klass* klass = this;
1544 while (klass != NULL) {
1545 if (InstanceKlass::cast(klass)->has_been_redefined()) {
1546 return true;
1547 }
1548 klass = klass->super();
1549 }
1550 return false;
1551 }
1552 #endif
1553
1554 // lookup a method in the default methods list then in all transitive interfaces
1555 // Do NOT return private or static methods
1556 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1557 Symbol* signature) const {
1558 Method* m = NULL;
1559 if (default_methods() != NULL) {
1560 m = find_method(default_methods(), name, signature);
1561 }
1562 // Look up interfaces
1563 if (m == NULL) {
1564 m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1565 }
1566 return m;
1567 }
1568
1569 // lookup a method in all the interfaces that this class implements
1570 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1571 // They should only be found in the initial InterfaceMethodRef
1572 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1573 Symbol* signature,
1574 DefaultsLookupMode defaults_mode) const {
1575 Array<Klass*>* all_ifs = transitive_interfaces();
1576 int num_ifs = all_ifs->length();
1577 InstanceKlass *ik = NULL;
1578 for (int i = 0; i < num_ifs; i++) {
1579 ik = InstanceKlass::cast(all_ifs->at(i));
1580 Method* m = ik->lookup_method(name, signature);
1581 if (m != NULL && m->is_public() && !m->is_static() &&
1582 ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1583 return m;
1584 }
1585 }
1586 return NULL;
1587 }
1588
1589 /* jni_id_for_impl for jfieldIds only */
1590 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_k, int offset) {
1591 MutexLocker ml(JfieldIdCreation_lock);
1592 // Retry lookup after we got the lock
1593 JNIid* probe = this_k->jni_ids() == NULL ? NULL : this_k->jni_ids()->find(offset);
1594 if (probe == NULL) {
1595 // Slow case, allocate new static field identifier
1596 probe = new JNIid(this_k(), offset, this_k->jni_ids());
1597 this_k->set_jni_ids(probe);
1598 }
1599 return probe;
1600 }
1601
1602
1603 /* jni_id_for for jfieldIds only */
1604 JNIid* InstanceKlass::jni_id_for(int offset) {
1605 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1606 if (probe == NULL) {
1607 probe = jni_id_for_impl(this, offset);
1608 }
1609 return probe;
1610 }
1611
1612 u2 InstanceKlass::enclosing_method_data(int offset) {
1613 Array<jushort>* inner_class_list = inner_classes();
1614 if (inner_class_list == NULL) {
1615 return 0;
1616 }
1617 int length = inner_class_list->length();
1618 if (length % inner_class_next_offset == 0) {
1619 return 0;
1620 } else {
1621 int index = length - enclosing_method_attribute_size;
1622 assert(offset < enclosing_method_attribute_size, "invalid offset");
1623 return inner_class_list->at(index + offset);
1624 }
1625 }
1626
1627 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1628 u2 method_index) {
1629 Array<jushort>* inner_class_list = inner_classes();
1630 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1631 int length = inner_class_list->length();
1632 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1633 int index = length - enclosing_method_attribute_size;
1634 inner_class_list->at_put(
1635 index + enclosing_method_class_index_offset, class_index);
1636 inner_class_list->at_put(
1637 index + enclosing_method_method_index_offset, method_index);
1638 }
1639 }
1640
1641 // Lookup or create a jmethodID.
1642 // This code is called by the VMThread and JavaThreads so the
1643 // locking has to be done very carefully to avoid deadlocks
1644 // and/or other cache consistency problems.
1645 //
1646 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, const methodHandle& method_h) {
1647 size_t idnum = (size_t)method_h->method_idnum();
1648 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1649 size_t length = 0;
1650 jmethodID id = NULL;
1651
1652 // We use a double-check locking idiom here because this cache is
1653 // performance sensitive. In the normal system, this cache only
1654 // transitions from NULL to non-NULL which is safe because we use
1655 // release_set_methods_jmethod_ids() to advertise the new cache.
1656 // A partially constructed cache should never be seen by a racing
1657 // thread. We also use release_store_ptr() to save a new jmethodID
1658 // in the cache so a partially constructed jmethodID should never be
1659 // seen either. Cache reads of existing jmethodIDs proceed without a
1660 // lock, but cache writes of a new jmethodID requires uniqueness and
1661 // creation of the cache itself requires no leaks so a lock is
1662 // generally acquired in those two cases.
1663 //
1664 // If the RedefineClasses() API has been used, then this cache can
1665 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1666 // Cache creation requires no leaks and we require safety between all
1667 // cache accesses and freeing of the old cache so a lock is generally
1668 // acquired when the RedefineClasses() API has been used.
1669
1670 if (jmeths != NULL) {
1671 // the cache already exists
1672 if (!ik_h->idnum_can_increment()) {
1673 // the cache can't grow so we can just get the current values
1674 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1675 } else {
1676 // cache can grow so we have to be more careful
1677 if (Threads::number_of_threads() == 0 ||
1678 SafepointSynchronize::is_at_safepoint()) {
1679 // we're single threaded or at a safepoint - no locking needed
1680 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1681 } else {
1682 MutexLocker ml(JmethodIdCreation_lock);
1683 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1684 }
1685 }
1686 }
1687 // implied else:
1688 // we need to allocate a cache so default length and id values are good
1689
1690 if (jmeths == NULL || // no cache yet
1691 length <= idnum || // cache is too short
1692 id == NULL) { // cache doesn't contain entry
1693
1694 // This function can be called by the VMThread so we have to do all
1695 // things that might block on a safepoint before grabbing the lock.
1696 // Otherwise, we can deadlock with the VMThread or have a cache
1697 // consistency issue. These vars keep track of what we might have
1698 // to free after the lock is dropped.
1699 jmethodID to_dealloc_id = NULL;
1700 jmethodID* to_dealloc_jmeths = NULL;
1701
1702 // may not allocate new_jmeths or use it if we allocate it
1703 jmethodID* new_jmeths = NULL;
1704 if (length <= idnum) {
1705 // allocate a new cache that might be used
1706 size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1707 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1708 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1709 // cache size is stored in element[0], other elements offset by one
1710 new_jmeths[0] = (jmethodID)size;
1711 }
1712
1713 // allocate a new jmethodID that might be used
1714 jmethodID new_id = NULL;
1715 if (method_h->is_old() && !method_h->is_obsolete()) {
1716 // The method passed in is old (but not obsolete), we need to use the current version
1717 Method* current_method = ik_h->method_with_idnum((int)idnum);
1718 assert(current_method != NULL, "old and but not obsolete, so should exist");
1719 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
1720 } else {
1721 // It is the current version of the method or an obsolete method,
1722 // use the version passed in
1723 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
1724 }
1725
1726 if (Threads::number_of_threads() == 0 ||
1727 SafepointSynchronize::is_at_safepoint()) {
1728 // we're single threaded or at a safepoint - no locking needed
1729 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1730 &to_dealloc_id, &to_dealloc_jmeths);
1731 } else {
1732 MutexLocker ml(JmethodIdCreation_lock);
1733 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1734 &to_dealloc_id, &to_dealloc_jmeths);
1735 }
1736
1737 // The lock has been dropped so we can free resources.
1738 // Free up either the old cache or the new cache if we allocated one.
1739 if (to_dealloc_jmeths != NULL) {
1740 FreeHeap(to_dealloc_jmeths);
1741 }
1742 // free up the new ID since it wasn't needed
1743 if (to_dealloc_id != NULL) {
1744 Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
1745 }
1746 }
1747 return id;
1748 }
1749
1750 // Figure out how many jmethodIDs haven't been allocated, and make
1751 // sure space for them is pre-allocated. This makes getting all
1752 // method ids much, much faster with classes with more than 8
1753 // methods, and has a *substantial* effect on performance with jvmti
1754 // code that loads all jmethodIDs for all classes.
1755 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1756 int new_jmeths = 0;
1757 int length = methods()->length();
1758 for (int index = start_offset; index < length; index++) {
1759 Method* m = methods()->at(index);
1760 jmethodID id = m->find_jmethod_id_or_null();
1761 if (id == NULL) {
1762 new_jmeths++;
1763 }
1764 }
1765 if (new_jmeths != 0) {
1766 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1767 }
1768 }
1769
1770 // Common code to fetch the jmethodID from the cache or update the
1771 // cache with the new jmethodID. This function should never do anything
1772 // that causes the caller to go to a safepoint or we can deadlock with
1773 // the VMThread or have cache consistency issues.
1774 //
1775 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1776 instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1777 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1778 jmethodID** to_dealloc_jmeths_p) {
1779 assert(new_id != NULL, "sanity check");
1780 assert(to_dealloc_id_p != NULL, "sanity check");
1781 assert(to_dealloc_jmeths_p != NULL, "sanity check");
1782 assert(Threads::number_of_threads() == 0 ||
1783 SafepointSynchronize::is_at_safepoint() ||
1784 JmethodIdCreation_lock->owned_by_self(), "sanity check");
1785
1786 // reacquire the cache - we are locked, single threaded or at a safepoint
1787 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1788 jmethodID id = NULL;
1789 size_t length = 0;
1790
1791 if (jmeths == NULL || // no cache yet
1792 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
1793 if (jmeths != NULL) {
1794 // copy any existing entries from the old cache
1795 for (size_t index = 0; index < length; index++) {
1796 new_jmeths[index+1] = jmeths[index+1];
1797 }
1798 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
1799 }
1800 ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1801 } else {
1802 // fetch jmethodID (if any) from the existing cache
1803 id = jmeths[idnum+1];
1804 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
1805 }
1806 if (id == NULL) {
1807 // No matching jmethodID in the existing cache or we have a new
1808 // cache or we just grew the cache. This cache write is done here
1809 // by the first thread to win the foot race because a jmethodID
1810 // needs to be unique once it is generally available.
1811 id = new_id;
1812
1813 // The jmethodID cache can be read while unlocked so we have to
1814 // make sure the new jmethodID is complete before installing it
1815 // in the cache.
1816 OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1817 } else {
1818 *to_dealloc_id_p = new_id; // save new id for later delete
1819 }
1820 return id;
1821 }
1822
1823
1824 // Common code to get the jmethodID cache length and the jmethodID
1825 // value at index idnum if there is one.
1826 //
1827 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1828 size_t idnum, size_t *length_p, jmethodID* id_p) {
1829 assert(cache != NULL, "sanity check");
1830 assert(length_p != NULL, "sanity check");
1831 assert(id_p != NULL, "sanity check");
1832
1833 // cache size is stored in element[0], other elements offset by one
1834 *length_p = (size_t)cache[0];
1835 if (*length_p <= idnum) { // cache is too short
1836 *id_p = NULL;
1837 } else {
1838 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
1839 }
1840 }
1841
1842
1843 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
1844 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1845 size_t idnum = (size_t)method->method_idnum();
1846 jmethodID* jmeths = methods_jmethod_ids_acquire();
1847 size_t length; // length assigned as debugging crumb
1848 jmethodID id = NULL;
1849 if (jmeths != NULL && // If there is a cache
1850 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
1851 id = jmeths[idnum+1]; // Look up the id (may be NULL)
1852 }
1853 return id;
1854 }
1855
1856 inline DependencyContext InstanceKlass::dependencies() {
1857 DependencyContext dep_context(&_dep_context);
1858 return dep_context;
1859 }
1860
1861 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
1862 return dependencies().mark_dependent_nmethods(changes);
1863 }
1864
1865 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1866 dependencies().add_dependent_nmethod(nm);
1867 }
1868
1869 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
1870 dependencies().remove_dependent_nmethod(nm, delete_immediately);
1871 }
1872
1873 #ifndef PRODUCT
1874 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1875 dependencies().print_dependent_nmethods(verbose);
1876 }
1877
1878 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1879 return dependencies().is_dependent_nmethod(nm);
1880 }
1881 #endif //PRODUCT
1882
1883 void InstanceKlass::clean_weak_instanceklass_links(BoolObjectClosure* is_alive) {
1884 clean_implementors_list(is_alive);
1885 clean_method_data(is_alive);
1886
1887 // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here.
1888 DependencyContext dep_context(&_dep_context);
1889 dep_context.expunge_stale_entries();
1890 }
1891
1892 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
1893 assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
1894 if (is_interface()) {
1895 if (ClassUnloading) {
1896 Klass* impl = implementor();
1897 if (impl != NULL) {
1898 if (!impl->is_loader_alive(is_alive)) {
1899 // remove this guy
1900 Klass** klass = adr_implementor();
1901 assert(klass != NULL, "null klass");
1902 if (klass != NULL) {
1903 *klass = NULL;
1904 }
1905 }
1906 }
1907 }
1908 }
1909 }
1910
1911 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
1912 for (int m = 0; m < methods()->length(); m++) {
1913 MethodData* mdo = methods()->at(m)->method_data();
1914 if (mdo != NULL) {
1915 mdo->clean_method_data(is_alive);
1916 }
1917 }
1918 }
1919
1920
1921 static void remove_unshareable_in_class(Klass* k) {
1922 // remove klass's unshareable info
1923 k->remove_unshareable_info();
1924 }
1925
1926 void InstanceKlass::remove_unshareable_info() {
1927 Klass::remove_unshareable_info();
1928 // Unlink the class
1929 if (is_linked()) {
1930 unlink_class();
1931 }
1932 init_implementor();
1933
1934 constants()->remove_unshareable_info();
1935
1936 assert(_dep_context == DependencyContext::EMPTY, "dependency context is not shareable");
1937
1938 for (int i = 0; i < methods()->length(); i++) {
1939 Method* m = methods()->at(i);
1940 m->remove_unshareable_info();
1941 }
1942
1943 // do array classes also.
1944 array_klasses_do(remove_unshareable_in_class);
1945 }
1946
1947 static void restore_unshareable_in_class(Klass* k, TRAPS) {
1948 // Array classes have null protection domain.
1949 // --> see ArrayKlass::complete_create_array_klass()
1950 k->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
1951 }
1952
1953 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
1954 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
1955 instanceKlassHandle ik(THREAD, this);
1956
1957 Array<Method*>* methods = ik->methods();
1958 int num_methods = methods->length();
1959 for (int index2 = 0; index2 < num_methods; ++index2) {
1960 methodHandle m(THREAD, methods->at(index2));
1961 m->restore_unshareable_info(CHECK);
1962 }
1963 if (JvmtiExport::has_redefined_a_class()) {
1964 // Reinitialize vtable because RedefineClasses may have changed some
1965 // entries in this vtable for super classes so the CDS vtable might
1966 // point to old or obsolete entries. RedefineClasses doesn't fix up
1967 // vtables in the shared system dictionary, only the main one.
1968 // It also redefines the itable too so fix that too.
1969 ResourceMark rm(THREAD);
1970 ik->vtable()->initialize_vtable(false, CHECK);
1971 ik->itable()->initialize_itable(false, CHECK);
1972 }
1973
1974 // restore constant pool resolved references
1975 ik->constants()->restore_unshareable_info(CHECK);
1976
1977 ik->array_klasses_do(restore_unshareable_in_class, CHECK);
1978 }
1979
1980 // returns true IFF is_in_error_state() has been changed as a result of this call.
1981 bool InstanceKlass::check_sharing_error_state() {
1982 assert(DumpSharedSpaces, "should only be called during dumping");
1983 bool old_state = is_in_error_state();
1984
1985 if (!is_in_error_state()) {
1986 bool bad = false;
1987 for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
1988 if (sup->is_in_error_state()) {
1989 bad = true;
1990 break;
1991 }
1992 }
1993 if (!bad) {
1994 Array<Klass*>* interfaces = transitive_interfaces();
1995 for (int i = 0; i < interfaces->length(); i++) {
1996 Klass* iface = interfaces->at(i);
1997 if (InstanceKlass::cast(iface)->is_in_error_state()) {
1998 bad = true;
1999 break;
2000 }
2001 }
2002 }
2003
2004 if (bad) {
2005 set_in_error_state();
2006 }
2007 }
2008
2009 return (old_state != is_in_error_state());
2010 }
2011
2012 static void clear_all_breakpoints(Method* m) {
2013 m->clear_all_breakpoints();
2014 }
2015
2016
2017 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2018 // notify the debugger
2019 if (JvmtiExport::should_post_class_unload()) {
2020 JvmtiExport::post_class_unload(ik);
2021 }
2022
2023 // notify ClassLoadingService of class unload
2024 ClassLoadingService::notify_class_unloaded(ik);
2025 }
2026
2027 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2028 // Clean up C heap
2029 ik->release_C_heap_structures();
2030 ik->constants()->release_C_heap_structures();
2031 }
2032
2033 void InstanceKlass::release_C_heap_structures() {
2034
2035 // Can't release the constant pool here because the constant pool can be
2036 // deallocated separately from the InstanceKlass for default methods and
2037 // redefine classes.
2038
2039 // Deallocate oop map cache
2040 if (_oop_map_cache != NULL) {
2041 delete _oop_map_cache;
2042 _oop_map_cache = NULL;
2043 }
2044
2045 // Deallocate JNI identifiers for jfieldIDs
2046 JNIid::deallocate(jni_ids());
2047 set_jni_ids(NULL);
2048
2049 jmethodID* jmeths = methods_jmethod_ids_acquire();
2050 if (jmeths != (jmethodID*)NULL) {
2051 release_set_methods_jmethod_ids(NULL);
2052 FreeHeap(jmeths);
2053 }
2054
2055 // Deallocate MemberNameTable
2056 {
2057 Mutex* lock_or_null = SafepointSynchronize::is_at_safepoint() ? NULL : MemberNameTable_lock;
2058 MutexLockerEx ml(lock_or_null, Mutex::_no_safepoint_check_flag);
2059 MemberNameTable* mnt = member_names();
2060 if (mnt != NULL) {
2061 delete mnt;
2062 set_member_names(NULL);
2063 }
2064 }
2065
2066 // Release dependencies.
2067 // It is desirable to use DC::remove_all_dependents() here, but, unfortunately,
2068 // it is not safe (see JDK-8143408). The problem is that the klass dependency
2069 // context can contain live dependencies, since there's a race between nmethod &
2070 // klass unloading. If the klass is dead when nmethod unloading happens, relevant
2071 // dependencies aren't removed from the context associated with the class (see
2072 // nmethod::flush_dependencies). It ends up during klass unloading as seemingly
2073 // live dependencies pointing to unloaded nmethods and causes a crash in
2074 // DC::remove_all_dependents() when it touches unloaded nmethod.
2075 dependencies().wipe();
2076
2077 // Deallocate breakpoint records
2078 if (breakpoints() != 0x0) {
2079 methods_do(clear_all_breakpoints);
2080 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2081 }
2082
2083 // deallocate the cached class file
2084 if (_cached_class_file != NULL) {
2085 os::free(_cached_class_file);
2086 _cached_class_file = NULL;
2087 }
2088
2089 // Decrement symbol reference counts associated with the unloaded class.
2090 if (_name != NULL) _name->decrement_refcount();
2091 // unreference array name derived from this class name (arrays of an unloaded
2092 // class can't be referenced anymore).
2093 if (_array_name != NULL) _array_name->decrement_refcount();
2094 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2095
2096 assert(_total_instanceKlass_count >= 1, "Sanity check");
2097 Atomic::dec(&_total_instanceKlass_count);
2098 }
2099
2100 void InstanceKlass::set_source_debug_extension(char* array, int length) {
2101 if (array == NULL) {
2102 _source_debug_extension = NULL;
2103 } else {
2104 // Adding one to the attribute length in order to store a null terminator
2105 // character could cause an overflow because the attribute length is
2106 // already coded with an u4 in the classfile, but in practice, it's
2107 // unlikely to happen.
2108 assert((length+1) > length, "Overflow checking");
2109 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2110 for (int i = 0; i < length; i++) {
2111 sde[i] = array[i];
2112 }
2113 sde[length] = '\0';
2114 _source_debug_extension = sde;
2115 }
2116 }
2117
2118 address InstanceKlass::static_field_addr(int offset) {
2119 return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
2120 }
2121
2122
2123 const char* InstanceKlass::signature_name() const {
2124 int hash_len = 0;
2125 char hash_buf[40];
2126
2127 // If this is an anonymous class, append a hash to make the name unique
2128 if (is_anonymous()) {
2129 intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2130 jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2131 hash_len = (int)strlen(hash_buf);
2132 }
2133
2134 // Get the internal name as a c string
2135 const char* src = (const char*) (name()->as_C_string());
2136 const int src_length = (int)strlen(src);
2137
2138 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2139
2140 // Add L as type indicator
2141 int dest_index = 0;
2142 dest[dest_index++] = 'L';
2143
2144 // Add the actual class name
2145 for (int src_index = 0; src_index < src_length; ) {
2146 dest[dest_index++] = src[src_index++];
2147 }
2148
2149 // If we have a hash, append it
2150 for (int hash_index = 0; hash_index < hash_len; ) {
2151 dest[dest_index++] = hash_buf[hash_index++];
2152 }
2153
2154 // Add the semicolon and the NULL
2155 dest[dest_index++] = ';';
2156 dest[dest_index] = '\0';
2157 return dest;
2158 }
2159
2160 // different verisons of is_same_class_package
2161 bool InstanceKlass::is_same_class_package(Klass* class2) {
2162 if (class2->is_objArray_klass()) {
2163 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2164 }
2165 oop classloader2 = class2->class_loader();
2166 Symbol* classname2 = class2->name();
2167
2168 return InstanceKlass::is_same_class_package(class_loader(), name(),
2169 classloader2, classname2);
2170 }
2171
2172 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
2173 return InstanceKlass::is_same_class_package(class_loader(), name(),
2174 classloader2, classname2);
2175 }
2176
2177 // return true if two classes are in the same package, classloader
2178 // and classname information is enough to determine a class's package
2179 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
2180 oop class_loader2, Symbol* class_name2) {
2181 if (class_loader1 != class_loader2) {
2182 return false;
2183 } else if (class_name1 == class_name2) {
2184 return true; // skip painful bytewise comparison
2185 } else {
2186 ResourceMark rm;
2187
2188 // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
2189 // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
2190 // Otherwise, we just compare jbyte values between the strings.
2191 const jbyte *name1 = class_name1->base();
2192 const jbyte *name2 = class_name2->base();
2193
2194 const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
2195 const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
2196
2197 if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
2198 // One of the two doesn't have a package. Only return true
2199 // if the other one also doesn't have a package.
2200 return last_slash1 == last_slash2;
2201 } else {
2202 // Skip over '['s
2203 if (*name1 == '[') {
2204 do {
2205 name1++;
2206 } while (*name1 == '[');
2207 if (*name1 != 'L') {
2208 // Something is terribly wrong. Shouldn't be here.
2209 return false;
2210 }
2211 }
2212 if (*name2 == '[') {
2213 do {
2214 name2++;
2215 } while (*name2 == '[');
2216 if (*name2 != 'L') {
2217 // Something is terribly wrong. Shouldn't be here.
2218 return false;
2219 }
2220 }
2221
2222 // Check that package part is identical
2223 int length1 = last_slash1 - name1;
2224 int length2 = last_slash2 - name2;
2225
2226 return UTF8::equal(name1, length1, name2, length2);
2227 }
2228 }
2229 }
2230
2231 // Returns true iff super_method can be overridden by a method in targetclassname
2232 // See JSL 3rd edition 8.4.6.1
2233 // Assumes name-signature match
2234 // "this" is InstanceKlass of super_method which must exist
2235 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2236 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2237 // Private methods can not be overridden
2238 if (super_method->is_private()) {
2239 return false;
2240 }
2241 // If super method is accessible, then override
2242 if ((super_method->is_protected()) ||
2243 (super_method->is_public())) {
2244 return true;
2245 }
2246 // Package-private methods are not inherited outside of package
2247 assert(super_method->is_package_private(), "must be package private");
2248 return(is_same_class_package(targetclassloader(), targetclassname));
2249 }
2250
2251 /* defined for now in jvm.cpp, for historical reasons *--
2252 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2253 Symbol*& simple_name_result, TRAPS) {
2254 ...
2255 }
2256 */
2257
2258 // tell if two classes have the same enclosing class (at package level)
2259 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2260 Klass* class2_oop, TRAPS) {
2261 if (class2_oop == class1()) return true;
2262 if (!class2_oop->is_instance_klass()) return false;
2263 instanceKlassHandle class2(THREAD, class2_oop);
2264
2265 // must be in same package before we try anything else
2266 if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2267 return false;
2268
2269 // As long as there is an outer1.getEnclosingClass,
2270 // shift the search outward.
2271 instanceKlassHandle outer1 = class1;
2272 for (;;) {
2273 // As we walk along, look for equalities between outer1 and class2.
2274 // Eventually, the walks will terminate as outer1 stops
2275 // at the top-level class around the original class.
2276 bool ignore_inner_is_member;
2277 Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2278 CHECK_false);
2279 if (next == NULL) break;
2280 if (next == class2()) return true;
2281 outer1 = instanceKlassHandle(THREAD, next);
2282 }
2283
2284 // Now do the same for class2.
2285 instanceKlassHandle outer2 = class2;
2286 for (;;) {
2287 bool ignore_inner_is_member;
2288 Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2289 CHECK_false);
2290 if (next == NULL) break;
2291 // Might as well check the new outer against all available values.
2292 if (next == class1()) return true;
2293 if (next == outer1()) return true;
2294 outer2 = instanceKlassHandle(THREAD, next);
2295 }
2296
2297 // If by this point we have not found an equality between the
2298 // two classes, we know they are in separate package members.
2299 return false;
2300 }
2301
2302 bool InstanceKlass::find_inner_classes_attr(instanceKlassHandle k, int* ooff, int* noff, TRAPS) {
2303 constantPoolHandle i_cp(THREAD, k->constants());
2304 for (InnerClassesIterator iter(k); !iter.done(); iter.next()) {
2305 int ioff = iter.inner_class_info_index();
2306 if (ioff != 0) {
2307 // Check to see if the name matches the class we're looking for
2308 // before attempting to find the class.
2309 if (i_cp->klass_name_at_matches(k, ioff)) {
2310 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2311 if (k() == inner_klass) {
2312 *ooff = iter.outer_class_info_index();
2313 *noff = iter.inner_name_index();
2314 return true;
2315 }
2316 }
2317 }
2318 }
2319 return false;
2320 }
2321
2322 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle k, bool* inner_is_member, TRAPS) {
2323 instanceKlassHandle outer_klass;
2324 *inner_is_member = false;
2325 int ooff = 0, noff = 0;
2326 if (find_inner_classes_attr(k, &ooff, &noff, THREAD)) {
2327 constantPoolHandle i_cp(THREAD, k->constants());
2328 if (ooff != 0) {
2329 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2330 outer_klass = instanceKlassHandle(THREAD, ok);
2331 *inner_is_member = true;
2332 }
2333 if (outer_klass.is_null()) {
2334 // It may be anonymous; try for that.
2335 int encl_method_class_idx = k->enclosing_method_class_index();
2336 if (encl_method_class_idx != 0) {
2337 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2338 outer_klass = instanceKlassHandle(THREAD, ok);
2339 *inner_is_member = false;
2340 }
2341 }
2342 }
2343
2344 // If no inner class attribute found for this class.
2345 if (outer_klass.is_null()) return NULL;
2346
2347 // Throws an exception if outer klass has not declared k as an inner klass
2348 // We need evidence that each klass knows about the other, or else
2349 // the system could allow a spoof of an inner class to gain access rights.
2350 Reflection::check_for_inner_class(outer_klass, k, *inner_is_member, CHECK_NULL);
2351 return outer_klass();
2352 }
2353
2354 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2355 jint access = access_flags().as_int();
2356
2357 // But check if it happens to be member class.
2358 instanceKlassHandle ik(THREAD, this);
2359 InnerClassesIterator iter(ik);
2360 for (; !iter.done(); iter.next()) {
2361 int ioff = iter.inner_class_info_index();
2362 // Inner class attribute can be zero, skip it.
2363 // Strange but true: JVM spec. allows null inner class refs.
2364 if (ioff == 0) continue;
2365
2366 // only look at classes that are already loaded
2367 // since we are looking for the flags for our self.
2368 Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2369 if ((ik->name() == inner_name)) {
2370 // This is really a member class.
2371 access = iter.inner_access_flags();
2372 break;
2373 }
2374 }
2375 // Remember to strip ACC_SUPER bit
2376 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2377 }
2378
2379 jint InstanceKlass::jvmti_class_status() const {
2380 jint result = 0;
2381
2382 if (is_linked()) {
2383 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2384 }
2385
2386 if (is_initialized()) {
2387 assert(is_linked(), "Class status is not consistent");
2388 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2389 }
2390 if (is_in_error_state()) {
2391 result |= JVMTI_CLASS_STATUS_ERROR;
2392 }
2393 return result;
2394 }
2395
2396 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2397 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2398 int method_table_offset_in_words = ioe->offset()/wordSize;
2399 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2400 / itableOffsetEntry::size();
2401
2402 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2403 // If the interface isn't implemented by the receiver class,
2404 // the VM should throw IncompatibleClassChangeError.
2405 if (cnt >= nof_interfaces) {
2406 THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2407 }
2408
2409 Klass* ik = ioe->interface_klass();
2410 if (ik == holder) break;
2411 }
2412
2413 itableMethodEntry* ime = ioe->first_method_entry(this);
2414 Method* m = ime[index].method();
2415 if (m == NULL) {
2416 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2417 }
2418 return m;
2419 }
2420
2421
2422 #if INCLUDE_JVMTI
2423 // update default_methods for redefineclasses for methods that are
2424 // not yet in the vtable due to concurrent subclass define and superinterface
2425 // redefinition
2426 // Note: those in the vtable, should have been updated via adjust_method_entries
2427 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2428 // search the default_methods for uses of either obsolete or EMCP methods
2429 if (default_methods() != NULL) {
2430 for (int index = 0; index < default_methods()->length(); index ++) {
2431 Method* old_method = default_methods()->at(index);
2432 if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2433 continue; // skip uninteresting entries
2434 }
2435 assert(!old_method->is_deleted(), "default methods may not be deleted");
2436
2437 Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2438
2439 assert(new_method != NULL, "method_with_idnum() should not be NULL");
2440 assert(old_method != new_method, "sanity check");
2441
2442 default_methods()->at_put(index, new_method);
2443 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
2444 if (!(*trace_name_printed)) {
2445 // RC_TRACE_MESG macro has an embedded ResourceMark
2446 RC_TRACE_MESG(("adjust: klassname=%s default methods from name=%s",
2447 external_name(),
2448 old_method->method_holder()->external_name()));
2449 *trace_name_printed = true;
2450 }
2451 RC_TRACE(0x00100000, ("default method update: %s(%s) ",
2452 new_method->name()->as_C_string(),
2453 new_method->signature()->as_C_string()));
2454 }
2455 }
2456 }
2457 }
2458 #endif // INCLUDE_JVMTI
2459
2460 // On-stack replacement stuff
2461 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2462 // only one compilation can be active
2463 {
2464 // This is a short non-blocking critical region, so the no safepoint check is ok.
2465 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2466 assert(n->is_osr_method(), "wrong kind of nmethod");
2467 n->set_osr_link(osr_nmethods_head());
2468 set_osr_nmethods_head(n);
2469 // Raise the highest osr level if necessary
2470 if (TieredCompilation) {
2471 Method* m = n->method();
2472 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2473 }
2474 }
2475
2476 // Get rid of the osr methods for the same bci that have lower levels.
2477 if (TieredCompilation) {
2478 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2479 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2480 if (inv != NULL && inv->is_in_use()) {
2481 inv->make_not_entrant();
2482 }
2483 }
2484 }
2485 }
2486
2487
2488 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
2489 // This is a short non-blocking critical region, so the no safepoint check is ok.
2490 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2491 assert(n->is_osr_method(), "wrong kind of nmethod");
2492 nmethod* last = NULL;
2493 nmethod* cur = osr_nmethods_head();
2494 int max_level = CompLevel_none; // Find the max comp level excluding n
2495 Method* m = n->method();
2496 // Search for match
2497 while(cur != NULL && cur != n) {
2498 if (TieredCompilation && m == cur->method()) {
2499 // Find max level before n
2500 max_level = MAX2(max_level, cur->comp_level());
2501 }
2502 last = cur;
2503 cur = cur->osr_link();
2504 }
2505 nmethod* next = NULL;
2506 if (cur == n) {
2507 next = cur->osr_link();
2508 if (last == NULL) {
2509 // Remove first element
2510 set_osr_nmethods_head(next);
2511 } else {
2512 last->set_osr_link(next);
2513 }
2514 }
2515 n->set_osr_link(NULL);
2516 if (TieredCompilation) {
2517 cur = next;
2518 while (cur != NULL) {
2519 // Find max level after n
2520 if (m == cur->method()) {
2521 max_level = MAX2(max_level, cur->comp_level());
2522 }
2523 cur = cur->osr_link();
2524 }
2525 m->set_highest_osr_comp_level(max_level);
2526 }
2527 }
2528
2529 int InstanceKlass::mark_osr_nmethods(const Method* m) {
2530 // This is a short non-blocking critical region, so the no safepoint check is ok.
2531 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2532 nmethod* osr = osr_nmethods_head();
2533 int found = 0;
2534 while (osr != NULL) {
2535 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2536 if (osr->method() == m) {
2537 osr->mark_for_deoptimization();
2538 found++;
2539 }
2540 osr = osr->osr_link();
2541 }
2542 return found;
2543 }
2544
2545 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2546 // This is a short non-blocking critical region, so the no safepoint check is ok.
2547 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2548 nmethod* osr = osr_nmethods_head();
2549 nmethod* best = NULL;
2550 while (osr != NULL) {
2551 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2552 // There can be a time when a c1 osr method exists but we are waiting
2553 // for a c2 version. When c2 completes its osr nmethod we will trash
2554 // the c1 version and only be able to find the c2 version. However
2555 // while we overflow in the c1 code at back branches we don't want to
2556 // try and switch to the same code as we are already running
2557
2558 if (osr->method() == m &&
2559 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2560 if (match_level) {
2561 if (osr->comp_level() == comp_level) {
2562 // Found a match - return it.
2563 return osr;
2564 }
2565 } else {
2566 if (best == NULL || (osr->comp_level() > best->comp_level())) {
2567 if (osr->comp_level() == CompLevel_highest_tier) {
2568 // Found the best possible - return it.
2569 return osr;
2570 }
2571 best = osr;
2572 }
2573 }
2574 }
2575 osr = osr->osr_link();
2576 }
2577 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2578 return best;
2579 }
2580 return NULL;
2581 }
2582
2583 bool InstanceKlass::add_member_name(Handle mem_name) {
2584 jweak mem_name_wref = JNIHandles::make_weak_global(mem_name);
2585 MutexLocker ml(MemberNameTable_lock);
2586 DEBUG_ONLY(No_Safepoint_Verifier nsv);
2587
2588 // Check if method has been redefined while taking out MemberNameTable_lock, if so
2589 // return false. We cannot cache obsolete methods. They will crash when the function
2590 // is called!
2591 Method* method = (Method*)java_lang_invoke_MemberName::vmtarget(mem_name());
2592 if (method->is_obsolete()) {
2593 return false;
2594 } else if (method->is_old()) {
2595 // Replace method with redefined version
2596 java_lang_invoke_MemberName::set_vmtarget(mem_name(), method_with_idnum(method->method_idnum()));
2597 }
2598
2599 if (_member_names == NULL) {
2600 _member_names = new (ResourceObj::C_HEAP, mtClass) MemberNameTable(idnum_allocated_count());
2601 }
2602 _member_names->add_member_name(mem_name_wref);
2603 return true;
2604 }
2605
2606 // -----------------------------------------------------------------------------------------------------
2607 // Printing
2608
2609 #ifndef PRODUCT
2610
2611 #define BULLET " - "
2612
2613 static const char* state_names[] = {
2614 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2615 };
2616
2617 static void print_vtable(intptr_t* start, int len, outputStream* st) {
2618 for (int i = 0; i < len; i++) {
2619 intptr_t e = start[i];
2620 st->print("%d : " INTPTR_FORMAT, i, e);
2621 if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2622 st->print(" ");
2623 ((Metadata*)e)->print_value_on(st);
2624 }
2625 st->cr();
2626 }
2627 }
2628
2629 void InstanceKlass::print_on(outputStream* st) const {
2630 assert(is_klass(), "must be klass");
2631 Klass::print_on(st);
2632
2633 st->print(BULLET"instance size: %d", size_helper()); st->cr();
2634 st->print(BULLET"klass size: %d", size()); st->cr();
2635 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
2636 st->print(BULLET"state: "); st->print_cr("%s", state_names[_init_state]);
2637 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
2638 st->print(BULLET"super: "); super()->print_value_on_maybe_null(st); st->cr();
2639 st->print(BULLET"sub: ");
2640 Klass* sub = subklass();
2641 int n;
2642 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2643 if (n < MaxSubklassPrintSize) {
2644 sub->print_value_on(st);
2645 st->print(" ");
2646 }
2647 }
2648 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
2649 st->cr();
2650
2651 if (is_interface()) {
2652 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
2653 if (nof_implementors() == 1) {
2654 st->print_cr(BULLET"implementor: ");
2655 st->print(" ");
2656 implementor()->print_value_on(st);
2657 st->cr();
2658 }
2659 }
2660
2661 st->print(BULLET"arrays: "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2662 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
2663 if (Verbose || WizardMode) {
2664 Array<Method*>* method_array = methods();
2665 for (int i = 0; i < method_array->length(); i++) {
2666 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2667 }
2668 }
2669 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
2670 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
2671 if (Verbose && default_methods() != NULL) {
2672 Array<Method*>* method_array = default_methods();
2673 for (int i = 0; i < method_array->length(); i++) {
2674 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2675 }
2676 }
2677 if (default_vtable_indices() != NULL) {
2678 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
2679 }
2680 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
2681 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2682 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
2683 if (class_loader_data() != NULL) {
2684 st->print(BULLET"class loader data: ");
2685 class_loader_data()->print_value_on(st);
2686 st->cr();
2687 }
2688 st->print(BULLET"host class: "); host_klass()->print_value_on_maybe_null(st); st->cr();
2689 if (source_file_name() != NULL) {
2690 st->print(BULLET"source file: ");
2691 source_file_name()->print_value_on(st);
2692 st->cr();
2693 }
2694 if (source_debug_extension() != NULL) {
2695 st->print(BULLET"source debug extension: ");
2696 st->print("%s", source_debug_extension());
2697 st->cr();
2698 }
2699 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
2700 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
2701 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
2702 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
2703 {
2704 bool have_pv = false;
2705 // previous versions are linked together through the InstanceKlass
2706 for (InstanceKlass* pv_node = _previous_versions;
2707 pv_node != NULL;
2708 pv_node = pv_node->previous_versions()) {
2709 if (!have_pv)
2710 st->print(BULLET"previous version: ");
2711 have_pv = true;
2712 pv_node->constants()->print_value_on(st);
2713 }
2714 if (have_pv) st->cr();
2715 }
2716
2717 if (generic_signature() != NULL) {
2718 st->print(BULLET"generic signature: ");
2719 generic_signature()->print_value_on(st);
2720 st->cr();
2721 }
2722 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
2723 st->print(BULLET"java mirror: "); java_mirror()->print_value_on(st); st->cr();
2724 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
2725 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
2726 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
2727 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
2728 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2729 FieldPrinter print_static_field(st);
2730 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2731 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2732 FieldPrinter print_nonstatic_field(st);
2733 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
2734 ik->do_nonstatic_fields(&print_nonstatic_field);
2735
2736 st->print(BULLET"non-static oop maps: ");
2737 OopMapBlock* map = start_of_nonstatic_oop_maps();
2738 OopMapBlock* end_map = map + nonstatic_oop_map_count();
2739 while (map < end_map) {
2740 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2741 map++;
2742 }
2743 st->cr();
2744 }
2745
2746 #endif //PRODUCT
2747
2748 void InstanceKlass::print_value_on(outputStream* st) const {
2749 assert(is_klass(), "must be klass");
2750 if (Verbose || WizardMode) access_flags().print_on(st);
2751 name()->print_value_on(st);
2752 }
2753
2754 #ifndef PRODUCT
2755
2756 void FieldPrinter::do_field(fieldDescriptor* fd) {
2757 _st->print(BULLET);
2758 if (_obj == NULL) {
2759 fd->print_on(_st);
2760 _st->cr();
2761 } else {
2762 fd->print_on_for(_st, _obj);
2763 _st->cr();
2764 }
2765 }
2766
2767
2768 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
2769 Klass::oop_print_on(obj, st);
2770
2771 if (this == SystemDictionary::String_klass()) {
2772 typeArrayOop value = java_lang_String::value(obj);
2773 juint length = java_lang_String::length(obj);
2774 if (value != NULL &&
2775 value->is_typeArray() &&
2776 length <= (juint) value->length()) {
2777 st->print(BULLET"string: ");
2778 java_lang_String::print(obj, st);
2779 st->cr();
2780 if (!WizardMode) return; // that is enough
2781 }
2782 }
2783
2784 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
2785 FieldPrinter print_field(st, obj);
2786 do_nonstatic_fields(&print_field);
2787
2788 if (this == SystemDictionary::Class_klass()) {
2789 st->print(BULLET"signature: ");
2790 java_lang_Class::print_signature(obj, st);
2791 st->cr();
2792 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
2793 st->print(BULLET"fake entry for mirror: ");
2794 mirrored_klass->print_value_on_maybe_null(st);
2795 st->cr();
2796 Klass* array_klass = java_lang_Class::array_klass(obj);
2797 st->print(BULLET"fake entry for array: ");
2798 array_klass->print_value_on_maybe_null(st);
2799 st->cr();
2800 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
2801 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
2802 Klass* real_klass = java_lang_Class::as_Klass(obj);
2803 if (real_klass != NULL && real_klass->is_instance_klass()) {
2804 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
2805 }
2806 } else if (this == SystemDictionary::MethodType_klass()) {
2807 st->print(BULLET"signature: ");
2808 java_lang_invoke_MethodType::print_signature(obj, st);
2809 st->cr();
2810 }
2811 }
2812
2813 #endif //PRODUCT
2814
2815 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
2816 st->print("a ");
2817 name()->print_value_on(st);
2818 obj->print_address_on(st);
2819 if (this == SystemDictionary::String_klass()
2820 && java_lang_String::value(obj) != NULL) {
2821 ResourceMark rm;
2822 int len = java_lang_String::length(obj);
2823 int plen = (len < 24 ? len : 12);
2824 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
2825 st->print(" = \"%s\"", str);
2826 if (len > plen)
2827 st->print("...[%d]", len);
2828 } else if (this == SystemDictionary::Class_klass()) {
2829 Klass* k = java_lang_Class::as_Klass(obj);
2830 st->print(" = ");
2831 if (k != NULL) {
2832 k->print_value_on(st);
2833 } else {
2834 const char* tname = type2name(java_lang_Class::primitive_type(obj));
2835 st->print("%s", tname ? tname : "type?");
2836 }
2837 } else if (this == SystemDictionary::MethodType_klass()) {
2838 st->print(" = ");
2839 java_lang_invoke_MethodType::print_signature(obj, st);
2840 } else if (java_lang_boxing_object::is_instance(obj)) {
2841 st->print(" = ");
2842 java_lang_boxing_object::print(obj, st);
2843 } else if (this == SystemDictionary::LambdaForm_klass()) {
2844 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
2845 if (vmentry != NULL) {
2846 st->print(" => ");
2847 vmentry->print_value_on(st);
2848 }
2849 } else if (this == SystemDictionary::MemberName_klass()) {
2850 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
2851 if (vmtarget != NULL) {
2852 st->print(" = ");
2853 vmtarget->print_value_on(st);
2854 } else {
2855 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
2856 st->print(".");
2857 java_lang_invoke_MemberName::name(obj)->print_value_on(st);
2858 }
2859 }
2860 }
2861
2862 const char* InstanceKlass::internal_name() const {
2863 return external_name();
2864 }
2865
2866 #if INCLUDE_SERVICES
2867 // Size Statistics
2868 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
2869 Klass::collect_statistics(sz);
2870
2871 sz->_inst_size = HeapWordSize * size_helper();
2872 sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
2873 sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
2874 sz->_nonstatic_oopmap_bytes = HeapWordSize *
2875 ((is_interface() || is_anonymous()) ?
2876 align_object_offset(nonstatic_oop_map_size()) :
2877 nonstatic_oop_map_size());
2878
2879 int n = 0;
2880 n += (sz->_methods_array_bytes = sz->count_array(methods()));
2881 n += (sz->_method_ordering_bytes = sz->count_array(method_ordering()));
2882 n += (sz->_local_interfaces_bytes = sz->count_array(local_interfaces()));
2883 n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
2884 n += (sz->_fields_bytes = sz->count_array(fields()));
2885 n += (sz->_inner_classes_bytes = sz->count_array(inner_classes()));
2886 sz->_ro_bytes += n;
2887
2888 const ConstantPool* cp = constants();
2889 if (cp) {
2890 cp->collect_statistics(sz);
2891 }
2892
2893 const Annotations* anno = annotations();
2894 if (anno) {
2895 anno->collect_statistics(sz);
2896 }
2897
2898 const Array<Method*>* methods_array = methods();
2899 if (methods()) {
2900 for (int i = 0; i < methods_array->length(); i++) {
2901 Method* method = methods_array->at(i);
2902 if (method) {
2903 sz->_method_count ++;
2904 method->collect_statistics(sz);
2905 }
2906 }
2907 }
2908 }
2909 #endif // INCLUDE_SERVICES
2910
2911 // Verification
2912
2913 class VerifyFieldClosure: public OopClosure {
2914 protected:
2915 template <class T> void do_oop_work(T* p) {
2916 oop obj = oopDesc::load_decode_heap_oop(p);
2917 if (!obj->is_oop_or_null()) {
2918 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
2919 Universe::print();
2920 guarantee(false, "boom");
2921 }
2922 }
2923 public:
2924 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
2925 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
2926 };
2927
2928 void InstanceKlass::verify_on(outputStream* st) {
2929 #ifndef PRODUCT
2930 // Avoid redundant verifies, this really should be in product.
2931 if (_verify_count == Universe::verify_count()) return;
2932 _verify_count = Universe::verify_count();
2933 #endif
2934
2935 // Verify Klass
2936 Klass::verify_on(st);
2937
2938 // Verify that klass is present in ClassLoaderData
2939 guarantee(class_loader_data()->contains_klass(this),
2940 "this class isn't found in class loader data");
2941
2942 // Verify vtables
2943 if (is_linked()) {
2944 ResourceMark rm;
2945 // $$$ This used to be done only for m/s collections. Doing it
2946 // always seemed a valid generalization. (DLD -- 6/00)
2947 vtable()->verify(st);
2948 }
2949
2950 // Verify first subklass
2951 if (subklass() != NULL) {
2952 guarantee(subklass()->is_klass(), "should be klass");
2953 }
2954
2955 // Verify siblings
2956 Klass* super = this->super();
2957 Klass* sib = next_sibling();
2958 if (sib != NULL) {
2959 if (sib == this) {
2960 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
2961 }
2962
2963 guarantee(sib->is_klass(), "should be klass");
2964 guarantee(sib->super() == super, "siblings should have same superklass");
2965 }
2966
2967 // Verify implementor fields
2968 Klass* im = implementor();
2969 if (im != NULL) {
2970 guarantee(is_interface(), "only interfaces should have implementor set");
2971 guarantee(im->is_klass(), "should be klass");
2972 guarantee(!im->is_interface() || im == this,
2973 "implementors cannot be interfaces");
2974 }
2975
2976 // Verify local interfaces
2977 if (local_interfaces()) {
2978 Array<Klass*>* local_interfaces = this->local_interfaces();
2979 for (int j = 0; j < local_interfaces->length(); j++) {
2980 Klass* e = local_interfaces->at(j);
2981 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
2982 }
2983 }
2984
2985 // Verify transitive interfaces
2986 if (transitive_interfaces() != NULL) {
2987 Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
2988 for (int j = 0; j < transitive_interfaces->length(); j++) {
2989 Klass* e = transitive_interfaces->at(j);
2990 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
2991 }
2992 }
2993
2994 // Verify methods
2995 if (methods() != NULL) {
2996 Array<Method*>* methods = this->methods();
2997 for (int j = 0; j < methods->length(); j++) {
2998 guarantee(methods->at(j)->is_method(), "non-method in methods array");
2999 }
3000 for (int j = 0; j < methods->length() - 1; j++) {
3001 Method* m1 = methods->at(j);
3002 Method* m2 = methods->at(j + 1);
3003 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3004 }
3005 }
3006
3007 // Verify method ordering
3008 if (method_ordering() != NULL) {
3009 Array<int>* method_ordering = this->method_ordering();
3010 int length = method_ordering->length();
3011 if (JvmtiExport::can_maintain_original_method_order() ||
3012 ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3013 guarantee(length == methods()->length(), "invalid method ordering length");
3014 jlong sum = 0;
3015 for (int j = 0; j < length; j++) {
3016 int original_index = method_ordering->at(j);
3017 guarantee(original_index >= 0, "invalid method ordering index");
3018 guarantee(original_index < length, "invalid method ordering index");
3019 sum += original_index;
3020 }
3021 // Verify sum of indices 0,1,...,length-1
3022 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3023 } else {
3024 guarantee(length == 0, "invalid method ordering length");
3025 }
3026 }
3027
3028 // Verify default methods
3029 if (default_methods() != NULL) {
3030 Array<Method*>* methods = this->default_methods();
3031 for (int j = 0; j < methods->length(); j++) {
3032 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3033 }
3034 for (int j = 0; j < methods->length() - 1; j++) {
3035 Method* m1 = methods->at(j);
3036 Method* m2 = methods->at(j + 1);
3037 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3038 }
3039 }
3040
3041 // Verify JNI static field identifiers
3042 if (jni_ids() != NULL) {
3043 jni_ids()->verify(this);
3044 }
3045
3046 // Verify other fields
3047 if (array_klasses() != NULL) {
3048 guarantee(array_klasses()->is_klass(), "should be klass");
3049 }
3050 if (constants() != NULL) {
3051 guarantee(constants()->is_constantPool(), "should be constant pool");
3052 }
3053 const Klass* host = host_klass();
3054 if (host != NULL) {
3055 guarantee(host->is_klass(), "should be klass");
3056 }
3057 }
3058
3059 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3060 Klass::oop_verify_on(obj, st);
3061 VerifyFieldClosure blk;
3062 obj->oop_iterate_no_header(&blk);
3063 }
3064
3065
3066 // JNIid class for jfieldIDs only
3067 // Note to reviewers:
3068 // These JNI functions are just moved over to column 1 and not changed
3069 // in the compressed oops workspace.
3070 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3071 _holder = holder;
3072 _offset = offset;
3073 _next = next;
3074 debug_only(_is_static_field_id = false;)
3075 }
3076
3077
3078 JNIid* JNIid::find(int offset) {
3079 JNIid* current = this;
3080 while (current != NULL) {
3081 if (current->offset() == offset) return current;
3082 current = current->next();
3083 }
3084 return NULL;
3085 }
3086
3087 void JNIid::deallocate(JNIid* current) {
3088 while (current != NULL) {
3089 JNIid* next = current->next();
3090 delete current;
3091 current = next;
3092 }
3093 }
3094
3095
3096 void JNIid::verify(Klass* holder) {
3097 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3098 int end_field_offset;
3099 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3100
3101 JNIid* current = this;
3102 while (current != NULL) {
3103 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3104 #ifdef ASSERT
3105 int o = current->offset();
3106 if (current->is_static_field_id()) {
3107 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3108 }
3109 #endif
3110 current = current->next();
3111 }
3112 }
3113
3114
3115 #ifdef ASSERT
3116 void InstanceKlass::set_init_state(ClassState state) {
3117 bool good_state = is_shared() ? (_init_state <= state)
3118 : (_init_state < state);
3119 assert(good_state || state == allocated, "illegal state transition");
3120 _init_state = (u1)state;
3121 }
3122 #endif
3123
3124
3125
3126 // RedefineClasses() support for previous versions:
3127 int InstanceKlass::_previous_version_count = 0;
3128
3129 // Purge previous versions before adding new previous versions of the class.
3130 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
3131 if (ik->previous_versions() != NULL) {
3132 // This klass has previous versions so see what we can cleanup
3133 // while it is safe to do so.
3134
3135 int deleted_count = 0; // leave debugging breadcrumbs
3136 int live_count = 0;
3137 ClassLoaderData* loader_data = ik->class_loader_data();
3138 assert(loader_data != NULL, "should never be null");
3139
3140 // RC_TRACE macro has an embedded ResourceMark
3141 RC_TRACE(0x00000200, ("purge: %s: previous versions", ik->external_name()));
3142
3143 // previous versions are linked together through the InstanceKlass
3144 InstanceKlass* pv_node = ik->previous_versions();
3145 InstanceKlass* last = ik;
3146 int version = 0;
3147
3148 // check the previous versions list
3149 for (; pv_node != NULL; ) {
3150
3151 ConstantPool* pvcp = pv_node->constants();
3152 assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3153
3154 if (!pvcp->on_stack()) {
3155 // If the constant pool isn't on stack, none of the methods
3156 // are executing. Unlink this previous_version.
3157 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3158 // so will be deallocated during the next phase of class unloading.
3159 RC_TRACE(0x00000200, ("purge: previous version " INTPTR_FORMAT " is dead",
3160 p2i(pv_node)));
3161 // For debugging purposes.
3162 pv_node->set_is_scratch_class();
3163 pv_node->class_loader_data()->add_to_deallocate_list(pv_node);
3164 pv_node = pv_node->previous_versions();
3165 last->link_previous_versions(pv_node);
3166 deleted_count++;
3167 version++;
3168 continue;
3169 } else {
3170 RC_TRACE(0x00000200, ("purge: previous version " INTPTR_FORMAT " is alive",
3171 p2i(pv_node)));
3172 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3173 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3174 live_count++;
3175 }
3176
3177 // At least one method is live in this previous version.
3178 // Reset dead EMCP methods not to get breakpoints.
3179 // All methods are deallocated when all of the methods for this class are no
3180 // longer running.
3181 Array<Method*>* method_refs = pv_node->methods();
3182 if (method_refs != NULL) {
3183 RC_TRACE(0x00000200, ("purge: previous methods length=%d",
3184 method_refs->length()));
3185 for (int j = 0; j < method_refs->length(); j++) {
3186 Method* method = method_refs->at(j);
3187
3188 if (!method->on_stack()) {
3189 // no breakpoints for non-running methods
3190 if (method->is_running_emcp()) {
3191 method->set_running_emcp(false);
3192 }
3193 } else {
3194 assert (method->is_obsolete() || method->is_running_emcp(),
3195 "emcp method cannot run after emcp bit is cleared");
3196 // RC_TRACE macro has an embedded ResourceMark
3197 RC_TRACE(0x00000200,
3198 ("purge: %s(%s): prev method @%d in version @%d is alive",
3199 method->name()->as_C_string(),
3200 method->signature()->as_C_string(), j, version));
3201 }
3202 }
3203 }
3204 // next previous version
3205 last = pv_node;
3206 pv_node = pv_node->previous_versions();
3207 version++;
3208 }
3209 RC_TRACE(0x00000200,
3210 ("purge: previous version stats: live=%d, deleted=%d", live_count,
3211 deleted_count));
3212 }
3213 }
3214
3215 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3216 int emcp_method_count) {
3217 int obsolete_method_count = old_methods->length() - emcp_method_count;
3218
3219 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3220 _previous_versions != NULL) {
3221 // We have a mix of obsolete and EMCP methods so we have to
3222 // clear out any matching EMCP method entries the hard way.
3223 int local_count = 0;
3224 for (int i = 0; i < old_methods->length(); i++) {
3225 Method* old_method = old_methods->at(i);
3226 if (old_method->is_obsolete()) {
3227 // only obsolete methods are interesting
3228 Symbol* m_name = old_method->name();
3229 Symbol* m_signature = old_method->signature();
3230
3231 // previous versions are linked together through the InstanceKlass
3232 int j = 0;
3233 for (InstanceKlass* prev_version = _previous_versions;
3234 prev_version != NULL;
3235 prev_version = prev_version->previous_versions(), j++) {
3236
3237 Array<Method*>* method_refs = prev_version->methods();
3238 for (int k = 0; k < method_refs->length(); k++) {
3239 Method* method = method_refs->at(k);
3240
3241 if (!method->is_obsolete() &&
3242 method->name() == m_name &&
3243 method->signature() == m_signature) {
3244 // The current RedefineClasses() call has made all EMCP
3245 // versions of this method obsolete so mark it as obsolete
3246 RC_TRACE(0x00000400,
3247 ("add: %s(%s): flush obsolete method @%d in version @%d",
3248 m_name->as_C_string(), m_signature->as_C_string(), k, j));
3249
3250 method->set_is_obsolete();
3251 break;
3252 }
3253 }
3254
3255 // The previous loop may not find a matching EMCP method, but
3256 // that doesn't mean that we can optimize and not go any
3257 // further back in the PreviousVersion generations. The EMCP
3258 // method for this generation could have already been made obsolete,
3259 // but there still may be an older EMCP method that has not
3260 // been made obsolete.
3261 }
3262
3263 if (++local_count >= obsolete_method_count) {
3264 // no more obsolete methods so bail out now
3265 break;
3266 }
3267 }
3268 }
3269 }
3270 }
3271
3272 // Save the scratch_class as the previous version if any of the methods are running.
3273 // The previous_versions are used to set breakpoints in EMCP methods and they are
3274 // also used to clean MethodData links to redefined methods that are no longer running.
3275 void InstanceKlass::add_previous_version(instanceKlassHandle scratch_class,
3276 int emcp_method_count) {
3277 assert(Thread::current()->is_VM_thread(),
3278 "only VMThread can add previous versions");
3279
3280 // RC_TRACE macro has an embedded ResourceMark
3281 RC_TRACE(0x00000400, ("adding previous version ref for %s, EMCP_cnt=%d",
3282 scratch_class->external_name(), emcp_method_count));
3283
3284 // Clean out old previous versions
3285 purge_previous_versions(this);
3286
3287 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
3288 // a previous redefinition may be made obsolete by this redefinition.
3289 Array<Method*>* old_methods = scratch_class->methods();
3290 mark_newly_obsolete_methods(old_methods, emcp_method_count);
3291
3292 // If the constant pool for this previous version of the class
3293 // is not marked as being on the stack, then none of the methods
3294 // in this previous version of the class are on the stack so
3295 // we don't need to add this as a previous version.
3296 ConstantPool* cp_ref = scratch_class->constants();
3297 if (!cp_ref->on_stack()) {
3298 RC_TRACE(0x00000400, ("add: scratch class not added; no methods are running"));
3299 // For debugging purposes.
3300 scratch_class->set_is_scratch_class();
3301 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class());
3302 // Update count for class unloading.
3303 _previous_version_count--;
3304 return;
3305 }
3306
3307 if (emcp_method_count != 0) {
3308 // At least one method is still running, check for EMCP methods
3309 for (int i = 0; i < old_methods->length(); i++) {
3310 Method* old_method = old_methods->at(i);
3311 if (!old_method->is_obsolete() && old_method->on_stack()) {
3312 // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3313 // we can add breakpoints for it.
3314
3315 // We set the method->on_stack bit during safepoints for class redefinition
3316 // and use this bit to set the is_running_emcp bit.
3317 // After the safepoint, the on_stack bit is cleared and the running emcp
3318 // method may exit. If so, we would set a breakpoint in a method that
3319 // is never reached, but this won't be noticeable to the programmer.
3320 old_method->set_running_emcp(true);
3321 RC_TRACE(0x00000400, ("add: EMCP method %s is on_stack " INTPTR_FORMAT,
3322 old_method->name_and_sig_as_C_string(), p2i(old_method)));
3323 } else if (!old_method->is_obsolete()) {
3324 RC_TRACE(0x00000400, ("add: EMCP method %s is NOT on_stack " INTPTR_FORMAT,
3325 old_method->name_and_sig_as_C_string(), p2i(old_method)));
3326 }
3327 }
3328 }
3329
3330 // Add previous version if any methods are still running.
3331 RC_TRACE(0x00000400, ("add: scratch class added; one of its methods is on_stack"));
3332 assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3333 scratch_class->link_previous_versions(previous_versions());
3334 link_previous_versions(scratch_class());
3335 // Update count for class unloading.
3336 _previous_version_count++;
3337 } // end add_previous_version()
3338
3339
3340 Method* InstanceKlass::method_with_idnum(int idnum) {
3341 Method* m = NULL;
3342 if (idnum < methods()->length()) {
3343 m = methods()->at(idnum);
3344 }
3345 if (m == NULL || m->method_idnum() != idnum) {
3346 for (int index = 0; index < methods()->length(); ++index) {
3347 m = methods()->at(index);
3348 if (m->method_idnum() == idnum) {
3349 return m;
3350 }
3351 }
3352 // None found, return null for the caller to handle.
3353 return NULL;
3354 }
3355 return m;
3356 }
3357
3358
3359 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3360 if (idnum >= methods()->length()) {
3361 return NULL;
3362 }
3363 Method* m = methods()->at(idnum);
3364 if (m != NULL && m->orig_method_idnum() == idnum) {
3365 return m;
3366 }
3367 // Obsolete method idnum does not match the original idnum
3368 for (int index = 0; index < methods()->length(); ++index) {
3369 m = methods()->at(index);
3370 if (m->orig_method_idnum() == idnum) {
3371 return m;
3372 }
3373 }
3374 // None found, return null for the caller to handle.
3375 return NULL;
3376 }
3377
3378
3379 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3380 InstanceKlass* holder = get_klass_version(version);
3381 if (holder == NULL) {
3382 return NULL; // The version of klass is gone, no method is found
3383 }
3384 Method* method = holder->method_with_orig_idnum(idnum);
3385 return method;
3386 }
3387
3388
3389 jint InstanceKlass::get_cached_class_file_len() {
3390 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3391 }
3392
3393 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3394 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3395 }