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 "compiler/compileBroker.hpp"
31 #include "gc_implementation/shared/markSweep.inline.hpp"
32 #include "gc_interface/collectedHeap.inline.hpp"
33 #include "interpreter/oopMapCache.hpp"
34 #include "interpreter/rewriter.hpp"
35 #include "jvmtifiles/jvmti.h"
36 #include "memory/genOopClosures.inline.hpp"
37 #include "memory/heapInspection.hpp"
38 #include "memory/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.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/jvmtiRedefineClassesTrace.hpp"
52 #include "prims/jvmtiRedefineClasses.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 #if INCLUDE_ALL_GCS
67 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
68 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
69 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
70 #include "gc_implementation/g1/g1RemSet.inline.hpp"
71 #include "gc_implementation/g1/heapRegionManager.inline.hpp"
72 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
73 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
74 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
75 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
76 #include "oops/oop.pcgc.inline.hpp"
77 #endif // INCLUDE_ALL_GCS
78 #ifdef COMPILER1
79 #include "c1/c1_Compiler.hpp"
80 #endif
81
82 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
83
84 #ifdef DTRACE_ENABLED
85
86
87 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
88 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
89 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
90 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
91 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
92 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
93 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
94 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
95 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
96 { \
97 char* data = NULL; \
98 int len = 0; \
99 Symbol* name = (clss)->name(); \
100 if (name != NULL) { \
101 data = (char*)name->bytes(); \
102 len = name->utf8_length(); \
103 } \
104 HOTSPOT_CLASS_INITIALIZATION_##type( \
105 data, len, (clss)->class_loader(), thread_type); \
106 }
107
108 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
109 { \
110 char* data = NULL; \
111 int len = 0; \
112 Symbol* name = (clss)->name(); \
113 if (name != NULL) { \
114 data = (char*)name->bytes(); \
115 len = name->utf8_length(); \
116 } \
117 HOTSPOT_CLASS_INITIALIZATION_##type( \
118 data, len, (clss)->class_loader(), thread_type, wait); \
119 }
120
121 #else // ndef DTRACE_ENABLED
122
123 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
124 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
125
126 #endif // ndef DTRACE_ENABLED
127
128 volatile int InstanceKlass::_total_instanceKlass_count = 0;
129
130 InstanceKlass* InstanceKlass::allocate_instance_klass(
131 ClassLoaderData* loader_data,
132 int vtable_len,
133 int itable_len,
134 int static_field_size,
135 int nonstatic_oop_map_size,
136 ReferenceType rt,
137 AccessFlags access_flags,
138 Symbol* name,
139 Klass* super_klass,
140 bool is_anonymous,
141 TRAPS) {
142
143 int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
144 access_flags.is_interface(), is_anonymous);
145
146 // Allocation
147 InstanceKlass* ik;
148 if (rt == REF_NONE) {
149 if (name == vmSymbols::java_lang_Class()) {
150 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
151 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
152 access_flags, is_anonymous);
153 } else if (name == vmSymbols::java_lang_ClassLoader() ||
154 (SystemDictionary::ClassLoader_klass_loaded() &&
155 super_klass != NULL &&
156 super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
157 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
158 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
159 access_flags, is_anonymous);
160 } else {
161 // normal class
162 ik = new (loader_data, size, THREAD) InstanceKlass(
163 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
164 access_flags, is_anonymous);
165 }
166 } else {
167 // reference klass
168 ik = new (loader_data, size, THREAD) InstanceRefKlass(
169 vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
170 access_flags, is_anonymous);
171 }
172
173 // Check for pending exception before adding to the loader data and incrementing
174 // class count. Can get OOM here.
175 if (HAS_PENDING_EXCEPTION) {
176 return NULL;
177 }
178
179 // Add all classes to our internal class loader list here,
180 // including classes in the bootstrap (NULL) class loader.
181 loader_data->add_class(ik);
182
183 Atomic::inc(&_total_instanceKlass_count);
184 return ik;
185 }
186
187
188 // copy method ordering from resource area to Metaspace
189 void InstanceKlass::copy_method_ordering(intArray* m, TRAPS) {
190 if (m != NULL) {
191 // allocate a new array and copy contents (memcpy?)
192 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
193 for (int i = 0; i < m->length(); i++) {
194 _method_ordering->at_put(i, m->at(i));
195 }
196 } else {
197 _method_ordering = Universe::the_empty_int_array();
198 }
199 }
200
201 // create a new array of vtable_indices for default methods
202 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
203 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
204 assert(default_vtable_indices() == NULL, "only create once");
205 set_default_vtable_indices(vtable_indices);
206 return vtable_indices;
207 }
208
209 InstanceKlass::InstanceKlass(int vtable_len,
210 int itable_len,
211 int static_field_size,
212 int nonstatic_oop_map_size,
213 ReferenceType rt,
214 AccessFlags access_flags,
215 bool is_anonymous) {
216 No_Safepoint_Verifier no_safepoint; // until k becomes parsable
217
218 int iksize = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
219 access_flags.is_interface(), is_anonymous);
220
221 set_vtable_length(vtable_len);
222 set_itable_length(itable_len);
223 set_static_field_size(static_field_size);
224 set_nonstatic_oop_map_size(nonstatic_oop_map_size);
225 set_access_flags(access_flags);
226 _misc_flags = 0; // initialize to zero
227 set_is_anonymous(is_anonymous);
228 assert(size() == iksize, "wrong size for object");
229
230 set_array_klasses(NULL);
231 set_methods(NULL);
232 set_method_ordering(NULL);
233 set_default_methods(NULL);
234 set_default_vtable_indices(NULL);
235 set_local_interfaces(NULL);
236 set_transitive_interfaces(NULL);
237 init_implementor();
238 set_fields(NULL, 0);
239 set_constants(NULL);
240 set_class_loader_data(NULL);
241 set_source_file_name_index(0);
242 set_source_debug_extension(NULL, 0);
243 set_array_name(NULL);
244 set_inner_classes(NULL);
245 set_static_oop_field_count(0);
246 set_nonstatic_field_size(0);
247 set_is_marked_dependent(false);
248 set_has_unloaded_dependent(false);
249 set_init_state(InstanceKlass::allocated);
250 set_init_thread(NULL);
251 set_reference_type(rt);
252 set_oop_map_cache(NULL);
253 set_jni_ids(NULL);
254 set_osr_nmethods_head(NULL);
255 set_breakpoints(NULL);
256 init_previous_versions();
257 set_generic_signature_index(0);
258 release_set_methods_jmethod_ids(NULL);
259 set_annotations(NULL);
260 set_jvmti_cached_class_field_map(NULL);
261 set_initial_method_idnum(0);
262 _dependencies = NULL;
263 set_jvmti_cached_class_field_map(NULL);
264 set_cached_class_file(NULL);
265 set_initial_method_idnum(0);
266 set_minor_version(0);
267 set_major_version(0);
268 NOT_PRODUCT(_verify_count = 0;)
269
270 // initialize the non-header words to zero
271 intptr_t* p = (intptr_t*)this;
272 for (int index = InstanceKlass::header_size(); index < iksize; index++) {
273 p[index] = NULL_WORD;
274 }
275
276 // Set temporary value until parseClassFile updates it with the real instance
277 // size.
278 set_layout_helper(Klass::instance_layout_helper(0, true));
279 }
280
281
282 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
283 Array<Method*>* methods) {
284 if (methods != NULL && methods != Universe::the_empty_method_array() &&
285 !methods->is_shared()) {
286 for (int i = 0; i < methods->length(); i++) {
287 Method* method = methods->at(i);
288 if (method == NULL) continue; // maybe null if error processing
289 // Only want to delete methods that are not executing for RedefineClasses.
290 // The previous version will point to them so they're not totally dangling
291 assert (!method->on_stack(), "shouldn't be called with methods on stack");
292 MetadataFactory::free_metadata(loader_data, method);
293 }
294 MetadataFactory::free_array<Method*>(loader_data, methods);
295 }
296 }
297
298 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
299 Klass* super_klass,
300 Array<Klass*>* local_interfaces,
301 Array<Klass*>* transitive_interfaces) {
302 // Only deallocate transitive interfaces if not empty, same as super class
303 // or same as local interfaces. See code in parseClassFile.
304 Array<Klass*>* ti = transitive_interfaces;
305 if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
306 // check that the interfaces don't come from super class
307 Array<Klass*>* sti = (super_klass == NULL) ? NULL :
308 InstanceKlass::cast(super_klass)->transitive_interfaces();
309 if (ti != sti && ti != NULL && !ti->is_shared()) {
310 MetadataFactory::free_array<Klass*>(loader_data, ti);
311 }
312 }
313
314 // local interfaces can be empty
315 if (local_interfaces != Universe::the_empty_klass_array() &&
316 local_interfaces != NULL && !local_interfaces->is_shared()) {
317 MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
318 }
319 }
320
321 // This function deallocates the metadata and C heap pointers that the
322 // InstanceKlass points to.
323 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
324
325 // Orphan the mirror first, CMS thinks it's still live.
326 if (java_mirror() != NULL) {
327 java_lang_Class::set_klass(java_mirror(), NULL);
328 }
329
330 // Need to take this class off the class loader data list.
331 loader_data->remove_class(this);
332
333 // The array_klass for this class is created later, after error handling.
334 // For class redefinition, we keep the original class so this scratch class
335 // doesn't have an array class. Either way, assert that there is nothing
336 // to deallocate.
337 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
338
339 // Release C heap allocated data that this might point to, which includes
340 // reference counting symbol names.
341 release_C_heap_structures();
342
343 deallocate_methods(loader_data, methods());
344 set_methods(NULL);
345
346 if (method_ordering() != NULL &&
347 method_ordering() != Universe::the_empty_int_array() &&
348 !method_ordering()->is_shared()) {
349 MetadataFactory::free_array<int>(loader_data, method_ordering());
350 }
351 set_method_ordering(NULL);
352
353 // default methods can be empty
354 if (default_methods() != NULL &&
355 default_methods() != Universe::the_empty_method_array() &&
356 !default_methods()->is_shared()) {
357 MetadataFactory::free_array<Method*>(loader_data, default_methods());
358 }
359 // Do NOT deallocate the default methods, they are owned by superinterfaces.
360 set_default_methods(NULL);
361
362 // default methods vtable indices can be empty
363 if (default_vtable_indices() != NULL &&
364 !default_vtable_indices()->is_shared()) {
365 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
366 }
367 set_default_vtable_indices(NULL);
368
369
370 // This array is in Klass, but remove it with the InstanceKlass since
371 // this place would be the only caller and it can share memory with transitive
372 // interfaces.
373 if (secondary_supers() != NULL &&
374 secondary_supers() != Universe::the_empty_klass_array() &&
375 secondary_supers() != transitive_interfaces() &&
376 !secondary_supers()->is_shared()) {
377 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
378 }
379 set_secondary_supers(NULL);
380
381 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
382 set_transitive_interfaces(NULL);
383 set_local_interfaces(NULL);
384
385 if (fields() != NULL && !fields()->is_shared()) {
386 MetadataFactory::free_array<jushort>(loader_data, fields());
387 }
388 set_fields(NULL, 0);
389
390 // If a method from a redefined class is using this constant pool, don't
391 // delete it, yet. The new class's previous version will point to this.
392 if (constants() != NULL) {
393 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
394 if (!constants()->is_shared()) {
395 MetadataFactory::free_metadata(loader_data, constants());
396 }
397 set_constants(NULL);
398 }
399
400 if (inner_classes() != NULL &&
401 inner_classes() != Universe::the_empty_short_array() &&
402 !inner_classes()->is_shared()) {
403 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
404 }
405 set_inner_classes(NULL);
406
407 // We should deallocate the Annotations instance if it's not in shared spaces.
408 if (annotations() != NULL && !annotations()->is_shared()) {
409 MetadataFactory::free_metadata(loader_data, annotations());
410 }
411 set_annotations(NULL);
412 }
413
414 bool InstanceKlass::should_be_initialized() const {
415 return !is_initialized();
416 }
417
418 klassVtable* InstanceKlass::vtable() const {
419 return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
420 }
421
422 klassItable* InstanceKlass::itable() const {
423 return new klassItable(instanceKlassHandle(this));
424 }
425
426 void InstanceKlass::eager_initialize(Thread *thread) {
427 if (!EagerInitialization) return;
428
429 if (this->is_not_initialized()) {
430 // abort if the the class has a class initializer
431 if (this->class_initializer() != NULL) return;
432
433 // abort if it is java.lang.Object (initialization is handled in genesis)
434 Klass* super = this->super();
435 if (super == NULL) return;
436
437 // abort if the super class should be initialized
438 if (!InstanceKlass::cast(super)->is_initialized()) return;
439
440 // call body to expose the this pointer
441 instanceKlassHandle this_k(thread, this);
442 eager_initialize_impl(this_k);
443 }
444 }
445
446 // JVMTI spec thinks there are signers and protection domain in the
447 // instanceKlass. These accessors pretend these fields are there.
448 // The hprof specification also thinks these fields are in InstanceKlass.
449 oop InstanceKlass::protection_domain() const {
450 // return the protection_domain from the mirror
451 return java_lang_Class::protection_domain(java_mirror());
452 }
453
454 // To remove these from requires an incompatible change and CCC request.
455 objArrayOop InstanceKlass::signers() const {
456 // return the signers from the mirror
457 return java_lang_Class::signers(java_mirror());
458 }
459
460 oop InstanceKlass::init_lock() const {
461 // return the init lock from the mirror
462 oop lock = java_lang_Class::init_lock(java_mirror());
463 // Prevent reordering with any access of initialization state
464 OrderAccess::loadload();
465 assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
466 "only fully initialized state can have a null lock");
467 return lock;
468 }
469
470 // Set the initialization lock to null so the object can be GC'ed. Any racing
471 // threads to get this lock will see a null lock and will not lock.
472 // That's okay because they all check for initialized state after getting
473 // the lock and return.
474 void InstanceKlass::fence_and_clear_init_lock() {
475 // make sure previous stores are all done, notably the init_state.
476 OrderAccess::storestore();
477 java_lang_Class::set_init_lock(java_mirror(), NULL);
478 assert(!is_not_initialized(), "class must be initialized now");
479 }
480
481 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_k) {
482 EXCEPTION_MARK;
483 oop init_lock = this_k->init_lock();
484 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
485
486 // abort if someone beat us to the initialization
487 if (!this_k->is_not_initialized()) return; // note: not equivalent to is_initialized()
488
489 ClassState old_state = this_k->init_state();
490 link_class_impl(this_k, true, THREAD);
491 if (HAS_PENDING_EXCEPTION) {
492 CLEAR_PENDING_EXCEPTION;
493 // Abort if linking the class throws an exception.
494
495 // Use a test to avoid redundantly resetting the state if there's
496 // no change. Set_init_state() asserts that state changes make
497 // progress, whereas here we might just be spinning in place.
498 if( old_state != this_k->_init_state )
499 this_k->set_init_state (old_state);
500 } else {
501 // linking successfull, mark class as initialized
502 this_k->set_init_state (fully_initialized);
503 this_k->fence_and_clear_init_lock();
504 // trace
505 if (TraceClassInitialization) {
506 ResourceMark rm(THREAD);
507 tty->print_cr("[Initialized %s without side effects]", this_k->external_name());
508 }
509 }
510 }
511
512
513 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
514 // process. The step comments refers to the procedure described in that section.
515 // Note: implementation moved to static method to expose the this pointer.
516 void InstanceKlass::initialize(TRAPS) {
517 if (this->should_be_initialized()) {
518 HandleMark hm(THREAD);
519 instanceKlassHandle this_k(THREAD, this);
520 initialize_impl(this_k, CHECK);
521 // Note: at this point the class may be initialized
522 // OR it may be in the state of being initialized
523 // in case of recursive initialization!
524 } else {
525 assert(is_initialized(), "sanity check");
526 }
527 }
528
529
530 bool InstanceKlass::verify_code(
531 instanceKlassHandle this_k, bool throw_verifyerror, TRAPS) {
532 // 1) Verify the bytecodes
533 Verifier::Mode mode =
534 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
535 return Verifier::verify(this_k, mode, this_k->should_verify_class(), THREAD);
536 }
537
538
539 // Used exclusively by the shared spaces dump mechanism to prevent
540 // classes mapped into the shared regions in new VMs from appearing linked.
541
542 void InstanceKlass::unlink_class() {
543 assert(is_linked(), "must be linked");
544 _init_state = loaded;
545 }
546
547 void InstanceKlass::link_class(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, true, CHECK);
553 }
554 }
555
556 // Called to verify that a class can link during initialization, without
557 // throwing a VerifyError.
558 bool InstanceKlass::link_class_or_fail(TRAPS) {
559 assert(is_loaded(), "must be loaded");
560 if (!is_linked()) {
561 HandleMark hm(THREAD);
562 instanceKlassHandle this_k(THREAD, this);
563 link_class_impl(this_k, false, CHECK_false);
564 }
565 return is_linked();
566 }
567
568 bool InstanceKlass::link_class_impl(
569 instanceKlassHandle this_k, bool throw_verifyerror, TRAPS) {
570 // check for error state
571 if (this_k->is_in_error_state()) {
572 ResourceMark rm(THREAD);
573 THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
574 this_k->external_name(), false);
575 }
576 // return if already verified
577 if (this_k->is_linked()) {
578 return true;
579 }
580
581 // Timing
582 // timer handles recursion
583 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
584 JavaThread* jt = (JavaThread*)THREAD;
585
586 // link super class before linking this class
587 instanceKlassHandle super(THREAD, this_k->super());
588 if (super.not_null()) {
589 if (super->is_interface()) { // check if super class is an interface
590 ResourceMark rm(THREAD);
591 Exceptions::fthrow(
592 THREAD_AND_LOCATION,
593 vmSymbols::java_lang_IncompatibleClassChangeError(),
594 "class %s has interface %s as super class",
595 this_k->external_name(),
596 super->external_name()
597 );
598 return false;
599 }
600
601 link_class_impl(super, throw_verifyerror, CHECK_false);
602 }
603
604 // link all interfaces implemented by this class before linking this class
605 Array<Klass*>* interfaces = this_k->local_interfaces();
606 int num_interfaces = interfaces->length();
607 for (int index = 0; index < num_interfaces; index++) {
608 HandleMark hm(THREAD);
609 instanceKlassHandle ih(THREAD, interfaces->at(index));
610 link_class_impl(ih, throw_verifyerror, CHECK_false);
611 }
612
613 // in case the class is linked in the process of linking its superclasses
614 if (this_k->is_linked()) {
615 return true;
616 }
617
618 // trace only the link time for this klass that includes
619 // the verification time
620 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
621 ClassLoader::perf_class_link_selftime(),
622 ClassLoader::perf_classes_linked(),
623 jt->get_thread_stat()->perf_recursion_counts_addr(),
624 jt->get_thread_stat()->perf_timers_addr(),
625 PerfClassTraceTime::CLASS_LINK);
626
627 // verification & rewriting
628 {
629 oop init_lock = this_k->init_lock();
630 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
631 // rewritten will have been set if loader constraint error found
632 // on an earlier link attempt
633 // don't verify or rewrite if already rewritten
634
635 if (!this_k->is_linked()) {
636 if (!this_k->is_rewritten()) {
637 {
638 // Timer includes any side effects of class verification (resolution,
639 // etc), but not recursive entry into verify_code().
640 PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
641 ClassLoader::perf_class_verify_selftime(),
642 ClassLoader::perf_classes_verified(),
643 jt->get_thread_stat()->perf_recursion_counts_addr(),
644 jt->get_thread_stat()->perf_timers_addr(),
645 PerfClassTraceTime::CLASS_VERIFY);
646 bool verify_ok = verify_code(this_k, throw_verifyerror, THREAD);
647 if (!verify_ok) {
648 return false;
649 }
650 }
651
652 // Just in case a side-effect of verify linked this class already
653 // (which can sometimes happen since the verifier loads classes
654 // using custom class loaders, which are free to initialize things)
655 if (this_k->is_linked()) {
656 return true;
657 }
658
659 // also sets rewritten
660 this_k->rewrite_class(CHECK_false);
661 }
662
663 // relocate jsrs and link methods after they are all rewritten
664 this_k->link_methods(CHECK_false);
665
666 // Initialize the vtable and interface table after
667 // methods have been rewritten since rewrite may
668 // fabricate new Method*s.
669 // also does loader constraint checking
670 if (!this_k()->is_shared()) {
671 ResourceMark rm(THREAD);
672 this_k->vtable()->initialize_vtable(true, CHECK_false);
673 this_k->itable()->initialize_itable(true, CHECK_false);
674 }
675 #ifdef ASSERT
676 else {
677 ResourceMark rm(THREAD);
678 this_k->vtable()->verify(tty, true);
679 // In case itable verification is ever added.
680 // this_k->itable()->verify(tty, true);
681 }
682 #endif
683 this_k->set_init_state(linked);
684 if (JvmtiExport::should_post_class_prepare()) {
685 Thread *thread = THREAD;
686 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
687 JvmtiExport::post_class_prepare((JavaThread *) thread, this_k());
688 }
689 }
690 }
691 return true;
692 }
693
694
695 // Rewrite the byte codes of all of the methods of a class.
696 // The rewriter must be called exactly once. Rewriting must happen after
697 // verification but before the first method of the class is executed.
698 void InstanceKlass::rewrite_class(TRAPS) {
699 assert(is_loaded(), "must be loaded");
700 instanceKlassHandle this_k(THREAD, this);
701 if (this_k->is_rewritten()) {
702 assert(this_k()->is_shared(), "rewriting an unshared class?");
703 return;
704 }
705 Rewriter::rewrite(this_k, CHECK);
706 this_k->set_rewritten();
707 }
708
709 // Now relocate and link method entry points after class is rewritten.
710 // This is outside is_rewritten flag. In case of an exception, it can be
711 // executed more than once.
712 void InstanceKlass::link_methods(TRAPS) {
713 int len = methods()->length();
714 for (int i = len-1; i >= 0; i--) {
715 methodHandle m(THREAD, methods()->at(i));
716
717 // Set up method entry points for compiler and interpreter .
718 m->link_method(m, CHECK);
719
720 // This is for JVMTI and unrelated to relocator but the last thing we do
721 #ifdef ASSERT
722 if (StressMethodComparator) {
723 ResourceMark rm(THREAD);
724 static int nmc = 0;
725 for (int j = i; j >= 0 && j >= i-4; j--) {
726 if ((++nmc % 1000) == 0) tty->print_cr("Have run MethodComparator %d times...", nmc);
727 bool z = MethodComparator::methods_EMCP(m(),
728 methods()->at(j));
729 if (j == i && !z) {
730 tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
731 assert(z, "method must compare equal to itself");
732 }
733 }
734 }
735 #endif //ASSERT
736 }
737 }
738
739 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
740 void InstanceKlass::initialize_super_interfaces(instanceKlassHandle this_k, TRAPS) {
741 if (this_k->has_default_methods()) {
742 for (int i = 0; i < this_k->local_interfaces()->length(); ++i) {
743 Klass* iface = this_k->local_interfaces()->at(i);
744 InstanceKlass* ik = InstanceKlass::cast(iface);
745 if (ik->should_be_initialized()) {
746 if (ik->has_default_methods()) {
747 ik->initialize_super_interfaces(ik, THREAD);
748 }
749 // Only initialize() interfaces that "declare" concrete methods.
750 // has_default_methods drives searching superinterfaces since it
751 // means has_default_methods in its superinterface hierarchy
752 if (!HAS_PENDING_EXCEPTION && ik->declares_default_methods()) {
753 ik->initialize(THREAD);
754 }
755 if (HAS_PENDING_EXCEPTION) {
756 Handle e(THREAD, PENDING_EXCEPTION);
757 CLEAR_PENDING_EXCEPTION;
758 {
759 EXCEPTION_MARK;
760 // Locks object, set state, and notify all waiting threads
761 this_k->set_initialization_state_and_notify(
762 initialization_error, THREAD);
763
764 // ignore any exception thrown, superclass initialization error is
765 // thrown below
766 CLEAR_PENDING_EXCEPTION;
767 }
768 THROW_OOP(e());
769 }
770 }
771 }
772 }
773 }
774
775 void InstanceKlass::initialize_impl(instanceKlassHandle this_k, TRAPS) {
776 // Make sure klass is linked (verified) before initialization
777 // A class could already be verified, since it has been reflected upon.
778 this_k->link_class(CHECK);
779
780 DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_k()), -1);
781
782 bool wait = false;
783
784 // refer to the JVM book page 47 for description of steps
785 // Step 1
786 {
787 oop init_lock = this_k->init_lock();
788 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
789
790 Thread *self = THREAD; // it's passed the current thread
791
792 // Step 2
793 // If we were to use wait() instead of waitInterruptibly() then
794 // we might end up throwing IE from link/symbol resolution sites
795 // that aren't expected to throw. This would wreak havoc. See 6320309.
796 while(this_k->is_being_initialized() && !this_k->is_reentrant_initialization(self)) {
797 wait = true;
798 ol.waitUninterruptibly(CHECK);
799 }
800
801 // Step 3
802 if (this_k->is_being_initialized() && this_k->is_reentrant_initialization(self)) {
803 DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_k()), -1,wait);
804 return;
805 }
806
807 // Step 4
808 if (this_k->is_initialized()) {
809 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_k()), -1,wait);
810 return;
811 }
812
813 // Step 5
814 if (this_k->is_in_error_state()) {
815 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_k()), -1,wait);
816 ResourceMark rm(THREAD);
817 const char* desc = "Could not initialize class ";
818 const char* className = this_k->external_name();
819 size_t msglen = strlen(desc) + strlen(className) + 1;
820 char* message = NEW_RESOURCE_ARRAY(char, msglen);
821 if (NULL == message) {
822 // Out of memory: can't create detailed error message
823 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
824 } else {
825 jio_snprintf(message, msglen, "%s%s", desc, className);
826 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
827 }
828 }
829
830 // Step 6
831 this_k->set_init_state(being_initialized);
832 this_k->set_init_thread(self);
833 }
834
835 // Step 7
836 Klass* super_klass = this_k->super();
837 if (super_klass != NULL && !this_k->is_interface() && super_klass->should_be_initialized()) {
838 super_klass->initialize(THREAD);
839
840 if (HAS_PENDING_EXCEPTION) {
841 Handle e(THREAD, PENDING_EXCEPTION);
842 CLEAR_PENDING_EXCEPTION;
843 {
844 EXCEPTION_MARK;
845 this_k->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
846 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, superclass initialization error is thrown below
847 }
848 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_k()), -1,wait);
849 THROW_OOP(e());
850 }
851 }
852
853 // Recursively initialize any superinterfaces that declare default methods
854 // Only need to recurse if has_default_methods which includes declaring and
855 // inheriting default methods
856 if (this_k->has_default_methods()) {
857 this_k->initialize_super_interfaces(this_k, CHECK);
858 }
859
860 // Step 8
861 {
862 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
863 JavaThread* jt = (JavaThread*)THREAD;
864 DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_k()), -1,wait);
865 // Timer includes any side effects of class initialization (resolution,
866 // etc), but not recursive entry into call_class_initializer().
867 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
868 ClassLoader::perf_class_init_selftime(),
869 ClassLoader::perf_classes_inited(),
870 jt->get_thread_stat()->perf_recursion_counts_addr(),
871 jt->get_thread_stat()->perf_timers_addr(),
872 PerfClassTraceTime::CLASS_CLINIT);
873 this_k->call_class_initializer(THREAD);
874 }
875
876 // Step 9
877 if (!HAS_PENDING_EXCEPTION) {
878 this_k->set_initialization_state_and_notify(fully_initialized, CHECK);
879 { ResourceMark rm(THREAD);
880 debug_only(this_k->vtable()->verify(tty, true);)
881 }
882 }
883 else {
884 // Step 10 and 11
885 Handle e(THREAD, PENDING_EXCEPTION);
886 CLEAR_PENDING_EXCEPTION;
887 // JVMTI has already reported the pending exception
888 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
889 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
890 {
891 EXCEPTION_MARK;
892 this_k->set_initialization_state_and_notify(initialization_error, THREAD);
893 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
894 // JVMTI has already reported the pending exception
895 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
896 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
897 }
898 DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_k()), -1,wait);
899 if (e->is_a(SystemDictionary::Error_klass())) {
900 THROW_OOP(e());
901 } else {
902 JavaCallArguments args(e);
903 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
904 vmSymbols::throwable_void_signature(),
905 &args);
906 }
907 }
908 DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_k()), -1,wait);
909 }
910
911
912 // Note: implementation moved to static method to expose the this pointer.
913 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
914 instanceKlassHandle kh(THREAD, this);
915 set_initialization_state_and_notify_impl(kh, state, CHECK);
916 }
917
918 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_k, ClassState state, TRAPS) {
919 oop init_lock = this_k->init_lock();
920 ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
921 this_k->set_init_state(state);
922 this_k->fence_and_clear_init_lock();
923 ol.notify_all(CHECK);
924 }
925
926 // The embedded _implementor field can only record one implementor.
927 // When there are more than one implementors, the _implementor field
928 // is set to the interface Klass* itself. Following are the possible
929 // values for the _implementor field:
930 // NULL - no implementor
931 // implementor Klass* - one implementor
932 // self - more than one implementor
933 //
934 // The _implementor field only exists for interfaces.
935 void InstanceKlass::add_implementor(Klass* k) {
936 assert(Compile_lock->owned_by_self(), "");
937 assert(is_interface(), "not interface");
938 // Filter out my subinterfaces.
939 // (Note: Interfaces are never on the subklass list.)
940 if (InstanceKlass::cast(k)->is_interface()) return;
941
942 // Filter out subclasses whose supers already implement me.
943 // (Note: CHA must walk subclasses of direct implementors
944 // in order to locate indirect implementors.)
945 Klass* sk = InstanceKlass::cast(k)->super();
946 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
947 // We only need to check one immediate superclass, since the
948 // implements_interface query looks at transitive_interfaces.
949 // Any supers of the super have the same (or fewer) transitive_interfaces.
950 return;
951
952 Klass* ik = implementor();
953 if (ik == NULL) {
954 set_implementor(k);
955 } else if (ik != this) {
956 // There is already an implementor. Use itself as an indicator of
957 // more than one implementors.
958 set_implementor(this);
959 }
960
961 // The implementor also implements the transitive_interfaces
962 for (int index = 0; index < local_interfaces()->length(); index++) {
963 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
964 }
965 }
966
967 void InstanceKlass::init_implementor() {
968 if (is_interface()) {
969 set_implementor(NULL);
970 }
971 }
972
973
974 void InstanceKlass::process_interfaces(Thread *thread) {
975 // link this class into the implementors list of every interface it implements
976 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
977 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
978 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
979 assert(interf->is_interface(), "expected interface");
980 interf->add_implementor(this);
981 }
982 }
983
984 bool InstanceKlass::can_be_primary_super_slow() const {
985 if (is_interface())
986 return false;
987 else
988 return Klass::can_be_primary_super_slow();
989 }
990
991 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
992 // The secondaries are the implemented interfaces.
993 InstanceKlass* ik = InstanceKlass::cast(this);
994 Array<Klass*>* interfaces = ik->transitive_interfaces();
995 int num_secondaries = num_extra_slots + interfaces->length();
996 if (num_secondaries == 0) {
997 // Must share this for correct bootstrapping!
998 set_secondary_supers(Universe::the_empty_klass_array());
999 return NULL;
1000 } else if (num_extra_slots == 0) {
1001 // The secondary super list is exactly the same as the transitive interfaces.
1002 // Redefine classes has to be careful not to delete this!
1003 set_secondary_supers(interfaces);
1004 return NULL;
1005 } else {
1006 // Copy transitive interfaces to a temporary growable array to be constructed
1007 // into the secondary super list with extra slots.
1008 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1009 for (int i = 0; i < interfaces->length(); i++) {
1010 secondaries->push(interfaces->at(i));
1011 }
1012 return secondaries;
1013 }
1014 }
1015
1016 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
1017 if (k->is_interface()) {
1018 return implements_interface(k);
1019 } else {
1020 return Klass::compute_is_subtype_of(k);
1021 }
1022 }
1023
1024 bool InstanceKlass::implements_interface(Klass* k) const {
1025 if (this == k) return true;
1026 assert(k->is_interface(), "should be an interface class");
1027 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1028 if (transitive_interfaces()->at(i) == k) {
1029 return true;
1030 }
1031 }
1032 return false;
1033 }
1034
1035 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1036 // Verify direct super interface
1037 if (this == k) return true;
1038 assert(k->is_interface(), "should be an interface class");
1039 for (int i = 0; i < local_interfaces()->length(); i++) {
1040 if (local_interfaces()->at(i) == k) {
1041 return true;
1042 }
1043 }
1044 return false;
1045 }
1046
1047 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1048 if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
1049 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
1050 report_java_out_of_memory("Requested array size exceeds VM limit");
1051 JvmtiExport::post_array_size_exhausted();
1052 THROW_OOP_0(Universe::out_of_memory_error_array_size());
1053 }
1054 int size = objArrayOopDesc::object_size(length);
1055 Klass* ak = array_klass(n, CHECK_NULL);
1056 KlassHandle h_ak (THREAD, ak);
1057 objArrayOop o =
1058 (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
1059 return o;
1060 }
1061
1062 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1063 if (TraceFinalizerRegistration) {
1064 tty->print("Registered ");
1065 i->print_value_on(tty);
1066 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
1067 }
1068 instanceHandle h_i(THREAD, i);
1069 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1070 JavaValue result(T_VOID);
1071 JavaCallArguments args(h_i);
1072 methodHandle mh (THREAD, Universe::finalizer_register_method());
1073 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1074 return h_i();
1075 }
1076
1077 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1078 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1079 int size = size_helper(); // Query before forming handle.
1080
1081 KlassHandle h_k(THREAD, this);
1082
1083 instanceOop i;
1084
1085 i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
1086 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1087 i = register_finalizer(i, CHECK_NULL);
1088 }
1089 return i;
1090 }
1091
1092 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1093 if (is_interface() || is_abstract()) {
1094 ResourceMark rm(THREAD);
1095 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1096 : vmSymbols::java_lang_InstantiationException(), external_name());
1097 }
1098 if (this == SystemDictionary::Class_klass()) {
1099 ResourceMark rm(THREAD);
1100 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1101 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1102 }
1103 }
1104
1105 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1106 instanceKlassHandle this_k(THREAD, this);
1107 return array_klass_impl(this_k, or_null, n, THREAD);
1108 }
1109
1110 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_k, bool or_null, int n, TRAPS) {
1111 if (this_k->array_klasses() == NULL) {
1112 if (or_null) return NULL;
1113
1114 ResourceMark rm;
1115 JavaThread *jt = (JavaThread *)THREAD;
1116 {
1117 // Atomic creation of array_klasses
1118 MutexLocker mc(Compile_lock, THREAD); // for vtables
1119 MutexLocker ma(MultiArray_lock, THREAD);
1120
1121 // Check if update has already taken place
1122 if (this_k->array_klasses() == NULL) {
1123 Klass* k = ObjArrayKlass::allocate_objArray_klass(this_k->class_loader_data(), 1, this_k, CHECK_NULL);
1124 this_k->set_array_klasses(k);
1125 }
1126 }
1127 }
1128 // _this will always be set at this point
1129 ObjArrayKlass* oak = (ObjArrayKlass*)this_k->array_klasses();
1130 if (or_null) {
1131 return oak->array_klass_or_null(n);
1132 }
1133 return oak->array_klass(n, THREAD);
1134 }
1135
1136 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1137 return array_klass_impl(or_null, 1, THREAD);
1138 }
1139
1140 void InstanceKlass::call_class_initializer(TRAPS) {
1141 instanceKlassHandle ik (THREAD, this);
1142 call_class_initializer_impl(ik, THREAD);
1143 }
1144
1145 static int call_class_initializer_impl_counter = 0; // for debugging
1146
1147 Method* InstanceKlass::class_initializer() {
1148 Method* clinit = find_method(
1149 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1150 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1151 return clinit;
1152 }
1153 return NULL;
1154 }
1155
1156 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_k, TRAPS) {
1157 if (ReplayCompiles &&
1158 (ReplaySuppressInitializers == 1 ||
1159 ReplaySuppressInitializers >= 2 && this_k->class_loader() != NULL)) {
1160 // Hide the existence of the initializer for the purpose of replaying the compile
1161 return;
1162 }
1163
1164 methodHandle h_method(THREAD, this_k->class_initializer());
1165 assert(!this_k->is_initialized(), "we cannot initialize twice");
1166 if (TraceClassInitialization) {
1167 tty->print("%d Initializing ", call_class_initializer_impl_counter++);
1168 this_k->name()->print_value();
1169 tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_k());
1170 }
1171 if (h_method() != NULL) {
1172 JavaCallArguments args; // No arguments
1173 JavaValue result(T_VOID);
1174 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1175 }
1176 }
1177
1178
1179 void InstanceKlass::mask_for(methodHandle method, int bci,
1180 InterpreterOopMap* entry_for) {
1181 // Dirty read, then double-check under a lock.
1182 if (_oop_map_cache == NULL) {
1183 // Otherwise, allocate a new one.
1184 MutexLocker x(OopMapCacheAlloc_lock);
1185 // First time use. Allocate a cache in C heap
1186 if (_oop_map_cache == NULL) {
1187 // Release stores from OopMapCache constructor before assignment
1188 // to _oop_map_cache. C++ compilers on ppc do not emit the
1189 // required memory barrier only because of the volatile
1190 // qualifier of _oop_map_cache.
1191 OrderAccess::release_store_ptr(&_oop_map_cache, new OopMapCache());
1192 }
1193 }
1194 // _oop_map_cache is constant after init; lookup below does is own locking.
1195 _oop_map_cache->lookup(method, bci, entry_for);
1196 }
1197
1198
1199 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1200 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1201 Symbol* f_name = fs.name();
1202 Symbol* f_sig = fs.signature();
1203 if (f_name == name && f_sig == sig) {
1204 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1205 return true;
1206 }
1207 }
1208 return false;
1209 }
1210
1211
1212 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1213 const int n = local_interfaces()->length();
1214 for (int i = 0; i < n; i++) {
1215 Klass* intf1 = local_interfaces()->at(i);
1216 assert(intf1->is_interface(), "just checking type");
1217 // search for field in current interface
1218 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1219 assert(fd->is_static(), "interface field must be static");
1220 return intf1;
1221 }
1222 // search for field in direct superinterfaces
1223 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1224 if (intf2 != NULL) return intf2;
1225 }
1226 // otherwise field lookup fails
1227 return NULL;
1228 }
1229
1230
1231 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1232 // search order according to newest JVM spec (5.4.3.2, p.167).
1233 // 1) search for field in current klass
1234 if (find_local_field(name, sig, fd)) {
1235 return const_cast<InstanceKlass*>(this);
1236 }
1237 // 2) search for field recursively in direct superinterfaces
1238 { Klass* intf = find_interface_field(name, sig, fd);
1239 if (intf != NULL) return intf;
1240 }
1241 // 3) apply field lookup recursively if superclass exists
1242 { Klass* supr = super();
1243 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1244 }
1245 // 4) otherwise field lookup fails
1246 return NULL;
1247 }
1248
1249
1250 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1251 // search order according to newest JVM spec (5.4.3.2, p.167).
1252 // 1) search for field in current klass
1253 if (find_local_field(name, sig, fd)) {
1254 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1255 }
1256 // 2) search for field recursively in direct superinterfaces
1257 if (is_static) {
1258 Klass* intf = find_interface_field(name, sig, fd);
1259 if (intf != NULL) return intf;
1260 }
1261 // 3) apply field lookup recursively if superclass exists
1262 { Klass* supr = super();
1263 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1264 }
1265 // 4) otherwise field lookup fails
1266 return NULL;
1267 }
1268
1269
1270 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1271 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1272 if (fs.offset() == offset) {
1273 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1274 if (fd->is_static() == is_static) return true;
1275 }
1276 }
1277 return false;
1278 }
1279
1280
1281 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1282 Klass* klass = const_cast<InstanceKlass*>(this);
1283 while (klass != NULL) {
1284 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1285 return true;
1286 }
1287 klass = klass->super();
1288 }
1289 return false;
1290 }
1291
1292
1293 void InstanceKlass::methods_do(void f(Method* method)) {
1294 // Methods aren't stable until they are loaded. This can be read outside
1295 // a lock through the ClassLoaderData for profiling
1296 if (!is_loaded()) {
1297 return;
1298 }
1299
1300 int len = methods()->length();
1301 for (int index = 0; index < len; index++) {
1302 Method* m = methods()->at(index);
1303 assert(m->is_method(), "must be method");
1304 f(m);
1305 }
1306 }
1307
1308
1309 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1310 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1311 if (fs.access_flags().is_static()) {
1312 fieldDescriptor& fd = fs.field_descriptor();
1313 cl->do_field(&fd);
1314 }
1315 }
1316 }
1317
1318
1319 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1320 instanceKlassHandle h_this(THREAD, this);
1321 do_local_static_fields_impl(h_this, f, mirror, CHECK);
1322 }
1323
1324
1325 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_k,
1326 void f(fieldDescriptor* fd, Handle, TRAPS), Handle mirror, TRAPS) {
1327 for (JavaFieldStream fs(this_k()); !fs.done(); fs.next()) {
1328 if (fs.access_flags().is_static()) {
1329 fieldDescriptor& fd = fs.field_descriptor();
1330 f(&fd, mirror, CHECK);
1331 }
1332 }
1333 }
1334
1335
1336 static int compare_fields_by_offset(int* a, int* b) {
1337 return a[0] - b[0];
1338 }
1339
1340 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1341 InstanceKlass* super = superklass();
1342 if (super != NULL) {
1343 super->do_nonstatic_fields(cl);
1344 }
1345 fieldDescriptor fd;
1346 int length = java_fields_count();
1347 // In DebugInfo nonstatic fields are sorted by offset.
1348 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1349 int j = 0;
1350 for (int i = 0; i < length; i += 1) {
1351 fd.reinitialize(this, i);
1352 if (!fd.is_static()) {
1353 fields_sorted[j + 0] = fd.offset();
1354 fields_sorted[j + 1] = i;
1355 j += 2;
1356 }
1357 }
1358 if (j > 0) {
1359 length = j;
1360 // _sort_Fn is defined in growableArray.hpp.
1361 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1362 for (int i = 0; i < length; i += 2) {
1363 fd.reinitialize(this, fields_sorted[i + 1]);
1364 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1365 cl->do_field(&fd);
1366 }
1367 }
1368 FREE_C_HEAP_ARRAY(int, fields_sorted);
1369 }
1370
1371
1372 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1373 if (array_klasses() != NULL)
1374 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1375 }
1376
1377 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1378 if (array_klasses() != NULL)
1379 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1380 }
1381
1382 #ifdef ASSERT
1383 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
1384 int len = methods->length();
1385 for (int index = 0; index < len; index++) {
1386 Method* m = methods->at(index);
1387 assert(m->is_method(), "must be method");
1388 if (m->signature() == signature && m->name() == name) {
1389 return index;
1390 }
1391 }
1392 return -1;
1393 }
1394 #endif
1395
1396 static int binary_search(Array<Method*>* methods, Symbol* name) {
1397 int len = methods->length();
1398 // methods are sorted, so do binary search
1399 int l = 0;
1400 int h = len - 1;
1401 while (l <= h) {
1402 int mid = (l + h) >> 1;
1403 Method* m = methods->at(mid);
1404 assert(m->is_method(), "must be method");
1405 int res = m->name()->fast_compare(name);
1406 if (res == 0) {
1407 return mid;
1408 } else if (res < 0) {
1409 l = mid + 1;
1410 } else {
1411 h = mid - 1;
1412 }
1413 }
1414 return -1;
1415 }
1416
1417 // find_method looks up the name/signature in the local methods array
1418 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
1419 return find_method_impl(name, signature, find_overpass, find_static);
1420 }
1421
1422 Method* InstanceKlass::find_method_impl(Symbol* name, Symbol* signature,
1423 OverpassLookupMode overpass_mode, StaticLookupMode static_mode) const {
1424 return InstanceKlass::find_method_impl(methods(), name, signature, overpass_mode, static_mode);
1425 }
1426
1427 // find_instance_method looks up the name/signature in the local methods array
1428 // and skips over static methods
1429 Method* InstanceKlass::find_instance_method(
1430 Array<Method*>* methods, Symbol* name, Symbol* signature) {
1431 Method* meth = InstanceKlass::find_method_impl(methods, name, signature,
1432 find_overpass, skip_static);
1433 assert(((meth == NULL) || !meth->is_static()), "find_instance_method should have skipped statics");
1434 return meth;
1435 }
1436
1437 // find_instance_method looks up the name/signature in the local methods array
1438 // and skips over static methods
1439 Method* InstanceKlass::find_instance_method(Symbol* name, Symbol* signature) {
1440 return InstanceKlass::find_instance_method(methods(), name, signature);
1441 }
1442
1443 // find_method looks up the name/signature in the local methods array
1444 Method* InstanceKlass::find_method(
1445 Array<Method*>* methods, Symbol* name, Symbol* signature) {
1446 return InstanceKlass::find_method_impl(methods, name, signature, find_overpass, find_static);
1447 }
1448
1449 Method* InstanceKlass::find_method_impl(
1450 Array<Method*>* methods, Symbol* name, Symbol* signature, OverpassLookupMode overpass_mode, StaticLookupMode static_mode) {
1451 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode);
1452 return hit >= 0 ? methods->at(hit): NULL;
1453 }
1454
1455 bool InstanceKlass::method_matches(Method* m, Symbol* signature, bool skipping_overpass, bool skipping_static) {
1456 return (m->signature() == signature) &&
1457 (!skipping_overpass || !m->is_overpass()) &&
1458 (!skipping_static || !m->is_static());
1459 }
1460
1461 // Used directly for default_methods to find the index into the
1462 // default_vtable_indices, and indirectly by find_method
1463 // find_method_index looks in the local methods array to return the index
1464 // of the matching name/signature. If, overpass methods are being ignored,
1465 // the search continues to find a potential non-overpass match. This capability
1466 // is important during method resolution to prefer a static method, for example,
1467 // over an overpass method.
1468 int InstanceKlass::find_method_index(
1469 Array<Method*>* methods, Symbol* name, Symbol* signature, OverpassLookupMode overpass_mode, StaticLookupMode static_mode) {
1470 bool skipping_overpass = (overpass_mode == skip_overpass);
1471 bool skipping_static = (static_mode == skip_static);
1472 int hit = binary_search(methods, name);
1473 if (hit != -1) {
1474 Method* m = methods->at(hit);
1475
1476 // Do linear search to find matching signature. First, quick check
1477 // for common case, ignoring overpasses if requested.
1478 if (method_matches(m, signature, skipping_overpass, skipping_static)) return hit;
1479
1480 // search downwards through overloaded methods
1481 int i;
1482 for (i = hit - 1; i >= 0; --i) {
1483 Method* m = methods->at(i);
1484 assert(m->is_method(), "must be method");
1485 if (m->name() != name) break;
1486 if (method_matches(m, signature, skipping_overpass, skipping_static)) return i;
1487 }
1488 // search upwards
1489 for (i = hit + 1; i < methods->length(); ++i) {
1490 Method* m = methods->at(i);
1491 assert(m->is_method(), "must be method");
1492 if (m->name() != name) break;
1493 if (method_matches(m, signature, skipping_overpass, skipping_static)) return i;
1494 }
1495 // not found
1496 #ifdef ASSERT
1497 int index = (skipping_overpass || skipping_static) ? -1 : linear_search(methods, name, signature);
1498 assert(index == -1, err_msg("binary search should have found entry %d", index));
1499 #endif
1500 }
1501 return -1;
1502 }
1503 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
1504 return find_method_by_name(methods(), name, end);
1505 }
1506
1507 int InstanceKlass::find_method_by_name(
1508 Array<Method*>* methods, Symbol* name, int* end_ptr) {
1509 assert(end_ptr != NULL, "just checking");
1510 int start = binary_search(methods, name);
1511 int end = start + 1;
1512 if (start != -1) {
1513 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1514 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1515 *end_ptr = end;
1516 return start;
1517 }
1518 return -1;
1519 }
1520
1521 // uncached_lookup_method searches both the local class methods array and all
1522 // superclasses methods arrays, skipping any overpass methods in superclasses.
1523 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature, OverpassLookupMode overpass_mode) const {
1524 OverpassLookupMode overpass_local_mode = overpass_mode;
1525 Klass* klass = const_cast<InstanceKlass*>(this);
1526 while (klass != NULL) {
1527 Method* method = InstanceKlass::cast(klass)->find_method_impl(name, signature, overpass_local_mode, find_static);
1528 if (method != NULL) {
1529 return method;
1530 }
1531 klass = InstanceKlass::cast(klass)->super();
1532 overpass_local_mode = skip_overpass; // Always ignore overpass methods in superclasses
1533 }
1534 return NULL;
1535 }
1536
1537 #ifdef ASSERT
1538 // search through class hierarchy and return true if this class or
1539 // one of the superclasses was redefined
1540 bool InstanceKlass::has_redefined_this_or_super() const {
1541 const InstanceKlass* klass = this;
1542 while (klass != NULL) {
1543 if (klass->has_been_redefined()) {
1544 return true;
1545 }
1546 klass = InstanceKlass::cast(klass->super());
1547 }
1548 return false;
1549 }
1550 #endif
1551
1552 // lookup a method in the default methods list then in all transitive interfaces
1553 // Do NOT return private or static methods
1554 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1555 Symbol* signature) const {
1556 Method* m = NULL;
1557 if (default_methods() != NULL) {
1558 m = find_method(default_methods(), name, signature);
1559 }
1560 // Look up interfaces
1561 if (m == NULL) {
1562 m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1563 }
1564 return m;
1565 }
1566
1567 // lookup a method in all the interfaces that this class implements
1568 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1569 // They should only be found in the initial InterfaceMethodRef
1570 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1571 Symbol* signature,
1572 DefaultsLookupMode defaults_mode) const {
1573 Array<Klass*>* all_ifs = transitive_interfaces();
1574 int num_ifs = all_ifs->length();
1575 InstanceKlass *ik = NULL;
1576 for (int i = 0; i < num_ifs; i++) {
1577 ik = InstanceKlass::cast(all_ifs->at(i));
1578 Method* m = ik->lookup_method(name, signature);
1579 if (m != NULL && m->is_public() && !m->is_static() &&
1580 ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1581 return m;
1582 }
1583 }
1584 return NULL;
1585 }
1586
1587 /* jni_id_for_impl for jfieldIds only */
1588 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_k, int offset) {
1589 MutexLocker ml(JfieldIdCreation_lock);
1590 // Retry lookup after we got the lock
1591 JNIid* probe = this_k->jni_ids() == NULL ? NULL : this_k->jni_ids()->find(offset);
1592 if (probe == NULL) {
1593 // Slow case, allocate new static field identifier
1594 probe = new JNIid(this_k(), offset, this_k->jni_ids());
1595 this_k->set_jni_ids(probe);
1596 }
1597 return probe;
1598 }
1599
1600
1601 /* jni_id_for for jfieldIds only */
1602 JNIid* InstanceKlass::jni_id_for(int offset) {
1603 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1604 if (probe == NULL) {
1605 probe = jni_id_for_impl(this, offset);
1606 }
1607 return probe;
1608 }
1609
1610 u2 InstanceKlass::enclosing_method_data(int offset) {
1611 Array<jushort>* inner_class_list = inner_classes();
1612 if (inner_class_list == NULL) {
1613 return 0;
1614 }
1615 int length = inner_class_list->length();
1616 if (length % inner_class_next_offset == 0) {
1617 return 0;
1618 } else {
1619 int index = length - enclosing_method_attribute_size;
1620 assert(offset < enclosing_method_attribute_size, "invalid offset");
1621 return inner_class_list->at(index + offset);
1622 }
1623 }
1624
1625 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1626 u2 method_index) {
1627 Array<jushort>* inner_class_list = inner_classes();
1628 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1629 int length = inner_class_list->length();
1630 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1631 int index = length - enclosing_method_attribute_size;
1632 inner_class_list->at_put(
1633 index + enclosing_method_class_index_offset, class_index);
1634 inner_class_list->at_put(
1635 index + enclosing_method_method_index_offset, method_index);
1636 }
1637 }
1638
1639 // Lookup or create a jmethodID.
1640 // This code is called by the VMThread and JavaThreads so the
1641 // locking has to be done very carefully to avoid deadlocks
1642 // and/or other cache consistency problems.
1643 //
1644 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1645 size_t idnum = (size_t)method_h->method_idnum();
1646 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1647 size_t length = 0;
1648 jmethodID id = NULL;
1649
1650 // We use a double-check locking idiom here because this cache is
1651 // performance sensitive. In the normal system, this cache only
1652 // transitions from NULL to non-NULL which is safe because we use
1653 // release_set_methods_jmethod_ids() to advertise the new cache.
1654 // A partially constructed cache should never be seen by a racing
1655 // thread. We also use release_store_ptr() to save a new jmethodID
1656 // in the cache so a partially constructed jmethodID should never be
1657 // seen either. Cache reads of existing jmethodIDs proceed without a
1658 // lock, but cache writes of a new jmethodID requires uniqueness and
1659 // creation of the cache itself requires no leaks so a lock is
1660 // generally acquired in those two cases.
1661 //
1662 // If the RedefineClasses() API has been used, then this cache can
1663 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1664 // Cache creation requires no leaks and we require safety between all
1665 // cache accesses and freeing of the old cache so a lock is generally
1666 // acquired when the RedefineClasses() API has been used.
1667
1668 if (jmeths != NULL) {
1669 // the cache already exists
1670 if (!ik_h->idnum_can_increment()) {
1671 // the cache can't grow so we can just get the current values
1672 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1673 } else {
1674 // cache can grow so we have to be more careful
1675 if (Threads::number_of_threads() == 0 ||
1676 SafepointSynchronize::is_at_safepoint()) {
1677 // we're single threaded or at a safepoint - no locking needed
1678 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1679 } else {
1680 MutexLocker ml(JmethodIdCreation_lock);
1681 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1682 }
1683 }
1684 }
1685 // implied else:
1686 // we need to allocate a cache so default length and id values are good
1687
1688 if (jmeths == NULL || // no cache yet
1689 length <= idnum || // cache is too short
1690 id == NULL) { // cache doesn't contain entry
1691
1692 // This function can be called by the VMThread so we have to do all
1693 // things that might block on a safepoint before grabbing the lock.
1694 // Otherwise, we can deadlock with the VMThread or have a cache
1695 // consistency issue. These vars keep track of what we might have
1696 // to free after the lock is dropped.
1697 jmethodID to_dealloc_id = NULL;
1698 jmethodID* to_dealloc_jmeths = NULL;
1699
1700 // may not allocate new_jmeths or use it if we allocate it
1701 jmethodID* new_jmeths = NULL;
1702 if (length <= idnum) {
1703 // allocate a new cache that might be used
1704 size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1705 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1706 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1707 // cache size is stored in element[0], other elements offset by one
1708 new_jmeths[0] = (jmethodID)size;
1709 }
1710
1711 // allocate a new jmethodID that might be used
1712 jmethodID new_id = NULL;
1713 if (method_h->is_old() && !method_h->is_obsolete()) {
1714 // The method passed in is old (but not obsolete), we need to use the current version
1715 Method* current_method = ik_h->method_with_idnum((int)idnum);
1716 assert(current_method != NULL, "old and but not obsolete, so should exist");
1717 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
1718 } else {
1719 // It is the current version of the method or an obsolete method,
1720 // use the version passed in
1721 new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
1722 }
1723
1724 if (Threads::number_of_threads() == 0 ||
1725 SafepointSynchronize::is_at_safepoint()) {
1726 // we're single threaded or at a safepoint - no locking needed
1727 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1728 &to_dealloc_id, &to_dealloc_jmeths);
1729 } else {
1730 MutexLocker ml(JmethodIdCreation_lock);
1731 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1732 &to_dealloc_id, &to_dealloc_jmeths);
1733 }
1734
1735 // The lock has been dropped so we can free resources.
1736 // Free up either the old cache or the new cache if we allocated one.
1737 if (to_dealloc_jmeths != NULL) {
1738 FreeHeap(to_dealloc_jmeths);
1739 }
1740 // free up the new ID since it wasn't needed
1741 if (to_dealloc_id != NULL) {
1742 Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
1743 }
1744 }
1745 return id;
1746 }
1747
1748 // Figure out how many jmethodIDs haven't been allocated, and make
1749 // sure space for them is pre-allocated. This makes getting all
1750 // method ids much, much faster with classes with more than 8
1751 // methods, and has a *substantial* effect on performance with jvmti
1752 // code that loads all jmethodIDs for all classes.
1753 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1754 int new_jmeths = 0;
1755 int length = methods()->length();
1756 for (int index = start_offset; index < length; index++) {
1757 Method* m = methods()->at(index);
1758 jmethodID id = m->find_jmethod_id_or_null();
1759 if (id == NULL) {
1760 new_jmeths++;
1761 }
1762 }
1763 if (new_jmeths != 0) {
1764 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1765 }
1766 }
1767
1768 // Common code to fetch the jmethodID from the cache or update the
1769 // cache with the new jmethodID. This function should never do anything
1770 // that causes the caller to go to a safepoint or we can deadlock with
1771 // the VMThread or have cache consistency issues.
1772 //
1773 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1774 instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1775 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1776 jmethodID** to_dealloc_jmeths_p) {
1777 assert(new_id != NULL, "sanity check");
1778 assert(to_dealloc_id_p != NULL, "sanity check");
1779 assert(to_dealloc_jmeths_p != NULL, "sanity check");
1780 assert(Threads::number_of_threads() == 0 ||
1781 SafepointSynchronize::is_at_safepoint() ||
1782 JmethodIdCreation_lock->owned_by_self(), "sanity check");
1783
1784 // reacquire the cache - we are locked, single threaded or at a safepoint
1785 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1786 jmethodID id = NULL;
1787 size_t length = 0;
1788
1789 if (jmeths == NULL || // no cache yet
1790 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
1791 if (jmeths != NULL) {
1792 // copy any existing entries from the old cache
1793 for (size_t index = 0; index < length; index++) {
1794 new_jmeths[index+1] = jmeths[index+1];
1795 }
1796 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
1797 }
1798 ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1799 } else {
1800 // fetch jmethodID (if any) from the existing cache
1801 id = jmeths[idnum+1];
1802 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
1803 }
1804 if (id == NULL) {
1805 // No matching jmethodID in the existing cache or we have a new
1806 // cache or we just grew the cache. This cache write is done here
1807 // by the first thread to win the foot race because a jmethodID
1808 // needs to be unique once it is generally available.
1809 id = new_id;
1810
1811 // The jmethodID cache can be read while unlocked so we have to
1812 // make sure the new jmethodID is complete before installing it
1813 // in the cache.
1814 OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1815 } else {
1816 *to_dealloc_id_p = new_id; // save new id for later delete
1817 }
1818 return id;
1819 }
1820
1821
1822 // Common code to get the jmethodID cache length and the jmethodID
1823 // value at index idnum if there is one.
1824 //
1825 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1826 size_t idnum, size_t *length_p, jmethodID* id_p) {
1827 assert(cache != NULL, "sanity check");
1828 assert(length_p != NULL, "sanity check");
1829 assert(id_p != NULL, "sanity check");
1830
1831 // cache size is stored in element[0], other elements offset by one
1832 *length_p = (size_t)cache[0];
1833 if (*length_p <= idnum) { // cache is too short
1834 *id_p = NULL;
1835 } else {
1836 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
1837 }
1838 }
1839
1840
1841 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
1842 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1843 size_t idnum = (size_t)method->method_idnum();
1844 jmethodID* jmeths = methods_jmethod_ids_acquire();
1845 size_t length; // length assigned as debugging crumb
1846 jmethodID id = NULL;
1847 if (jmeths != NULL && // If there is a cache
1848 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
1849 id = jmeths[idnum+1]; // Look up the id (may be NULL)
1850 }
1851 return id;
1852 }
1853
1854 int nmethodBucket::decrement() {
1855 return Atomic::add(-1, (volatile int *)&_count);
1856 }
1857
1858 //
1859 // Walk the list of dependent nmethods searching for nmethods which
1860 // are dependent on the changes that were passed in and mark them for
1861 // deoptimization. Returns the number of nmethods found.
1862 //
1863 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
1864 assert_locked_or_safepoint(CodeCache_lock);
1865 int found = 0;
1866 nmethodBucket* b = _dependencies;
1867 while (b != NULL) {
1868 nmethod* nm = b->get_nmethod();
1869 // since dependencies aren't removed until an nmethod becomes a zombie,
1870 // the dependency list may contain nmethods which aren't alive.
1871 if (b->count() > 0 && nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1872 if (TraceDependencies) {
1873 ResourceMark rm;
1874 tty->print_cr("Marked for deoptimization");
1875 tty->print_cr(" context = %s", this->external_name());
1876 changes.print();
1877 nm->print();
1878 nm->print_dependencies();
1879 }
1880 nm->mark_for_deoptimization();
1881 found++;
1882 }
1883 b = b->next();
1884 }
1885 return found;
1886 }
1887
1888 void InstanceKlass::clean_dependent_nmethods() {
1889 assert_locked_or_safepoint(CodeCache_lock);
1890
1891 if (has_unloaded_dependent()) {
1892 nmethodBucket* b = _dependencies;
1893 nmethodBucket* last = NULL;
1894 while (b != NULL) {
1895 assert(b->count() >= 0, err_msg("bucket count: %d", b->count()));
1896
1897 nmethodBucket* next = b->next();
1898
1899 if (b->count() == 0) {
1900 if (last == NULL) {
1901 _dependencies = next;
1902 } else {
1903 last->set_next(next);
1904 }
1905 delete b;
1906 // last stays the same.
1907 } else {
1908 last = b;
1909 }
1910
1911 b = next;
1912 }
1913 set_has_unloaded_dependent(false);
1914 }
1915 #ifdef ASSERT
1916 else {
1917 // Verification
1918 for (nmethodBucket* b = _dependencies; b != NULL; b = b->next()) {
1919 assert(b->count() >= 0, err_msg("bucket count: %d", b->count()));
1920 assert(b->count() != 0, "empty buckets need to be cleaned");
1921 }
1922 }
1923 #endif
1924 }
1925
1926 //
1927 // Add an nmethodBucket to the list of dependencies for this nmethod.
1928 // It's possible that an nmethod has multiple dependencies on this klass
1929 // so a count is kept for each bucket to guarantee that creation and
1930 // deletion of dependencies is consistent.
1931 //
1932 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1933 assert_locked_or_safepoint(CodeCache_lock);
1934 nmethodBucket* b = _dependencies;
1935 nmethodBucket* last = NULL;
1936 while (b != NULL) {
1937 if (nm == b->get_nmethod()) {
1938 b->increment();
1939 return;
1940 }
1941 b = b->next();
1942 }
1943 _dependencies = new nmethodBucket(nm, _dependencies);
1944 }
1945
1946
1947 //
1948 // Decrement count of the nmethod in the dependency list and remove
1949 // the bucket competely when the count goes to 0. This method must
1950 // find a corresponding bucket otherwise there's a bug in the
1951 // recording of dependecies.
1952 //
1953 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
1954 assert_locked_or_safepoint(CodeCache_lock);
1955 nmethodBucket* b = _dependencies;
1956 nmethodBucket* last = NULL;
1957 while (b != NULL) {
1958 if (nm == b->get_nmethod()) {
1959 int val = b->decrement();
1960 guarantee(val >= 0, err_msg("Underflow: %d", val));
1961 if (val == 0) {
1962 set_has_unloaded_dependent(true);
1963 }
1964 return;
1965 }
1966 last = b;
1967 b = b->next();
1968 }
1969 #ifdef ASSERT
1970 tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1971 nm->print();
1972 #endif // ASSERT
1973 ShouldNotReachHere();
1974 }
1975
1976
1977 #ifndef PRODUCT
1978 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1979 nmethodBucket* b = _dependencies;
1980 int idx = 0;
1981 while (b != NULL) {
1982 nmethod* nm = b->get_nmethod();
1983 tty->print("[%d] count=%d { ", idx++, b->count());
1984 if (!verbose) {
1985 nm->print_on(tty, "nmethod");
1986 tty->print_cr(" } ");
1987 } else {
1988 nm->print();
1989 nm->print_dependencies();
1990 tty->print_cr("--- } ");
1991 }
1992 b = b->next();
1993 }
1994 }
1995
1996
1997 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1998 nmethodBucket* b = _dependencies;
1999 while (b != NULL) {
2000 if (nm == b->get_nmethod()) {
2001 #ifdef ASSERT
2002 int count = b->count();
2003 assert(count >= 0, err_msg("count shouldn't be negative: %d", count));
2004 #endif
2005 return true;
2006 }
2007 b = b->next();
2008 }
2009 return false;
2010 }
2011 #endif //PRODUCT
2012
2013
2014 // Garbage collection
2015
2016 #ifdef ASSERT
2017 template <class T> void assert_is_in(T *p) {
2018 T heap_oop = oopDesc::load_heap_oop(p);
2019 if (!oopDesc::is_null(heap_oop)) {
2020 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
2021 assert(Universe::heap()->is_in(o), "should be in heap");
2022 }
2023 }
2024 template <class T> void assert_is_in_closed_subset(T *p) {
2025 T heap_oop = oopDesc::load_heap_oop(p);
2026 if (!oopDesc::is_null(heap_oop)) {
2027 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
2028 assert(Universe::heap()->is_in_closed_subset(o),
2029 err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
2030 }
2031 }
2032 template <class T> void assert_is_in_reserved(T *p) {
2033 T heap_oop = oopDesc::load_heap_oop(p);
2034 if (!oopDesc::is_null(heap_oop)) {
2035 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
2036 assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
2037 }
2038 }
2039 template <class T> void assert_nothing(T *p) {}
2040
2041 #else
2042 template <class T> void assert_is_in(T *p) {}
2043 template <class T> void assert_is_in_closed_subset(T *p) {}
2044 template <class T> void assert_is_in_reserved(T *p) {}
2045 template <class T> void assert_nothing(T *p) {}
2046 #endif // ASSERT
2047
2048 //
2049 // Macros that iterate over areas of oops which are specialized on type of
2050 // oop pointer either narrow or wide, depending on UseCompressedOops
2051 //
2052 // Parameters are:
2053 // T - type of oop to point to (either oop or narrowOop)
2054 // start_p - starting pointer for region to iterate over
2055 // count - number of oops or narrowOops to iterate over
2056 // do_oop - action to perform on each oop (it's arbitrary C code which
2057 // makes it more efficient to put in a macro rather than making
2058 // it a template function)
2059 // assert_fn - assert function which is template function because performance
2060 // doesn't matter when enabled.
2061 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
2062 T, start_p, count, do_oop, \
2063 assert_fn) \
2064 { \
2065 T* p = (T*)(start_p); \
2066 T* const end = p + (count); \
2067 while (p < end) { \
2068 (assert_fn)(p); \
2069 do_oop; \
2070 ++p; \
2071 } \
2072 }
2073
2074 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
2075 T, start_p, count, do_oop, \
2076 assert_fn) \
2077 { \
2078 T* const start = (T*)(start_p); \
2079 T* p = start + (count); \
2080 while (start < p) { \
2081 --p; \
2082 (assert_fn)(p); \
2083 do_oop; \
2084 } \
2085 }
2086
2087 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
2088 T, start_p, count, low, high, \
2089 do_oop, assert_fn) \
2090 { \
2091 T* const l = (T*)(low); \
2092 T* const h = (T*)(high); \
2093 assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
2094 mask_bits((intptr_t)h, sizeof(T)-1) == 0, \
2095 "bounded region must be properly aligned"); \
2096 T* p = (T*)(start_p); \
2097 T* end = p + (count); \
2098 if (p < l) p = l; \
2099 if (end > h) end = h; \
2100 while (p < end) { \
2101 (assert_fn)(p); \
2102 do_oop; \
2103 ++p; \
2104 } \
2105 }
2106
2107
2108 // The following macros call specialized macros, passing either oop or
2109 // narrowOop as the specialization type. These test the UseCompressedOops
2110 // flag.
2111 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \
2112 { \
2113 /* Compute oopmap block range. The common case \
2114 is nonstatic_oop_map_size == 1. */ \
2115 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
2116 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
2117 if (UseCompressedOops) { \
2118 while (map < end_map) { \
2119 InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
2120 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
2121 do_oop, assert_fn) \
2122 ++map; \
2123 } \
2124 } else { \
2125 while (map < end_map) { \
2126 InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
2127 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2128 do_oop, assert_fn) \
2129 ++map; \
2130 } \
2131 } \
2132 }
2133
2134 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \
2135 { \
2136 OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \
2137 OopMapBlock* map = start_map + nonstatic_oop_map_count(); \
2138 if (UseCompressedOops) { \
2139 while (start_map < map) { \
2140 --map; \
2141 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \
2142 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
2143 do_oop, assert_fn) \
2144 } \
2145 } else { \
2146 while (start_map < map) { \
2147 --map; \
2148 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \
2149 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2150 do_oop, assert_fn) \
2151 } \
2152 } \
2153 }
2154
2155 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \
2156 assert_fn) \
2157 { \
2158 /* Compute oopmap block range. The common case is \
2159 nonstatic_oop_map_size == 1, so we accept the \
2160 usually non-existent extra overhead of examining \
2161 all the maps. */ \
2162 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
2163 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
2164 if (UseCompressedOops) { \
2165 while (map < end_map) { \
2166 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
2167 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
2168 low, high, \
2169 do_oop, assert_fn) \
2170 ++map; \
2171 } \
2172 } else { \
2173 while (map < end_map) { \
2174 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
2175 obj->obj_field_addr<oop>(map->offset()), map->count(), \
2176 low, high, \
2177 do_oop, assert_fn) \
2178 ++map; \
2179 } \
2180 } \
2181 }
2182
2183 void InstanceKlass::oop_follow_contents(oop obj) {
2184 assert(obj != NULL, "can't follow the content of NULL object");
2185 MarkSweep::follow_klass(obj->klass());
2186 InstanceKlass_OOP_MAP_ITERATE( \
2187 obj, \
2188 MarkSweep::mark_and_push(p), \
2189 assert_is_in_closed_subset)
2190 }
2191
2192 #if INCLUDE_ALL_GCS
2193 void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
2194 oop obj) {
2195 assert(obj != NULL, "can't follow the content of NULL object");
2196 PSParallelCompact::follow_klass(cm, obj->klass());
2197 // Only mark the header and let the scan of the meta-data mark
2198 // everything else.
2199 InstanceKlass_OOP_MAP_ITERATE( \
2200 obj, \
2201 PSParallelCompact::mark_and_push(cm, p), \
2202 assert_is_in)
2203 }
2204 #endif // INCLUDE_ALL_GCS
2205
2206 // closure's do_metadata() method dictates whether the given closure should be
2207 // applied to the klass ptr in the object header.
2208
2209 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
2210 \
2211 int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
2212 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2213 /* header */ \
2214 if_do_metadata_checked(closure, nv_suffix) { \
2215 closure->do_klass##nv_suffix(obj->klass()); \
2216 } \
2217 InstanceKlass_OOP_MAP_ITERATE( \
2218 obj, \
2219 SpecializationStats:: \
2220 record_do_oop_call##nv_suffix(SpecializationStats::ik); \
2221 (closure)->do_oop##nv_suffix(p), \
2222 assert_is_in_closed_subset) \
2223 return size_helper(); \
2224 }
2225
2226 #if INCLUDE_ALL_GCS
2227 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
2228 \
2229 int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \
2230 OopClosureType* closure) { \
2231 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
2232 \
2233 assert_should_ignore_metadata(closure, nv_suffix); \
2234 \
2235 /* instance variables */ \
2236 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2237 obj, \
2238 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
2239 (closure)->do_oop##nv_suffix(p), \
2240 assert_is_in_closed_subset) \
2241 return size_helper(); \
2242 }
2243 #endif // INCLUDE_ALL_GCS
2244
2245 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
2246 \
2247 int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \
2248 OopClosureType* closure, \
2249 MemRegion mr) { \
2250 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2251 if_do_metadata_checked(closure, nv_suffix) { \
2252 if (mr.contains(obj)) { \
2253 closure->do_klass##nv_suffix(obj->klass()); \
2254 } \
2255 } \
2256 InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
2257 obj, mr.start(), mr.end(), \
2258 (closure)->do_oop##nv_suffix(p), \
2259 assert_is_in_closed_subset) \
2260 return size_helper(); \
2261 }
2262
2263 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2264 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2265 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2266 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2267 #if INCLUDE_ALL_GCS
2268 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2269 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2270 #endif // INCLUDE_ALL_GCS
2271
2272 int InstanceKlass::oop_adjust_pointers(oop obj) {
2273 int size = size_helper();
2274 InstanceKlass_OOP_MAP_ITERATE( \
2275 obj, \
2276 MarkSweep::adjust_pointer(p), \
2277 assert_is_in)
2278 return size;
2279 }
2280
2281 #if INCLUDE_ALL_GCS
2282 void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
2283 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2284 obj, \
2285 if (PSScavenge::should_scavenge(p)) { \
2286 pm->claim_or_forward_depth(p); \
2287 }, \
2288 assert_nothing )
2289 }
2290
2291 int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
2292 int size = size_helper();
2293 InstanceKlass_OOP_MAP_ITERATE( \
2294 obj, \
2295 PSParallelCompact::adjust_pointer(p), \
2296 assert_is_in)
2297 return size;
2298 }
2299
2300 #endif // INCLUDE_ALL_GCS
2301
2302 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
2303 assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
2304 if (is_interface()) {
2305 if (ClassUnloading) {
2306 Klass* impl = implementor();
2307 if (impl != NULL) {
2308 if (!impl->is_loader_alive(is_alive)) {
2309 // remove this guy
2310 Klass** klass = adr_implementor();
2311 assert(klass != NULL, "null klass");
2312 if (klass != NULL) {
2313 *klass = NULL;
2314 }
2315 }
2316 }
2317 }
2318 }
2319 }
2320
2321 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
2322 for (int m = 0; m < methods()->length(); m++) {
2323 MethodData* mdo = methods()->at(m)->method_data();
2324 if (mdo != NULL) {
2325 mdo->clean_method_data(is_alive);
2326 }
2327 }
2328 }
2329
2330
2331 static void remove_unshareable_in_class(Klass* k) {
2332 // remove klass's unshareable info
2333 k->remove_unshareable_info();
2334 }
2335
2336 void InstanceKlass::remove_unshareable_info() {
2337 Klass::remove_unshareable_info();
2338 // Unlink the class
2339 if (is_linked()) {
2340 unlink_class();
2341 }
2342 init_implementor();
2343
2344 constants()->remove_unshareable_info();
2345
2346 for (int i = 0; i < methods()->length(); i++) {
2347 Method* m = methods()->at(i);
2348 m->remove_unshareable_info();
2349 }
2350
2351 // do array classes also.
2352 array_klasses_do(remove_unshareable_in_class);
2353 }
2354
2355 static void restore_unshareable_in_class(Klass* k, TRAPS) {
2356 // Array classes have null protection domain.
2357 // --> see ArrayKlass::complete_create_array_klass()
2358 k->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2359 }
2360
2361 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2362 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2363 instanceKlassHandle ik(THREAD, this);
2364
2365 Array<Method*>* methods = ik->methods();
2366 int num_methods = methods->length();
2367 for (int index2 = 0; index2 < num_methods; ++index2) {
2368 methodHandle m(THREAD, methods->at(index2));
2369 m->restore_unshareable_info(CHECK);
2370 }
2371 if (JvmtiExport::has_redefined_a_class()) {
2372 // Reinitialize vtable because RedefineClasses may have changed some
2373 // entries in this vtable for super classes so the CDS vtable might
2374 // point to old or obsolete entries. RedefineClasses doesn't fix up
2375 // vtables in the shared system dictionary, only the main one.
2376 // It also redefines the itable too so fix that too.
2377 ResourceMark rm(THREAD);
2378 ik->vtable()->initialize_vtable(false, CHECK);
2379 ik->itable()->initialize_itable(false, CHECK);
2380 }
2381
2382 // restore constant pool resolved references
2383 ik->constants()->restore_unshareable_info(CHECK);
2384
2385 ik->array_klasses_do(restore_unshareable_in_class, CHECK);
2386 }
2387
2388 // returns true IFF is_in_error_state() has been changed as a result of this call.
2389 bool InstanceKlass::check_sharing_error_state() {
2390 assert(DumpSharedSpaces, "should only be called during dumping");
2391 bool old_state = is_in_error_state();
2392
2393 if (!is_in_error_state()) {
2394 bool bad = false;
2395 for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2396 if (sup->is_in_error_state()) {
2397 bad = true;
2398 break;
2399 }
2400 }
2401 if (!bad) {
2402 Array<Klass*>* interfaces = transitive_interfaces();
2403 for (int i = 0; i < interfaces->length(); i++) {
2404 Klass* iface = interfaces->at(i);
2405 if (InstanceKlass::cast(iface)->is_in_error_state()) {
2406 bad = true;
2407 break;
2408 }
2409 }
2410 }
2411
2412 if (bad) {
2413 set_in_error_state();
2414 }
2415 }
2416
2417 return (old_state != is_in_error_state());
2418 }
2419
2420 static void clear_all_breakpoints(Method* m) {
2421 m->clear_all_breakpoints();
2422 }
2423
2424
2425 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2426 // notify the debugger
2427 if (JvmtiExport::should_post_class_unload()) {
2428 JvmtiExport::post_class_unload(ik);
2429 }
2430
2431 // notify ClassLoadingService of class unload
2432 ClassLoadingService::notify_class_unloaded(ik);
2433 }
2434
2435 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2436 // Clean up C heap
2437 ik->release_C_heap_structures();
2438 ik->constants()->release_C_heap_structures();
2439 }
2440
2441 void InstanceKlass::release_C_heap_structures() {
2442
2443 // Can't release the constant pool here because the constant pool can be
2444 // deallocated separately from the InstanceKlass for default methods and
2445 // redefine classes.
2446
2447 // Deallocate oop map cache
2448 if (_oop_map_cache != NULL) {
2449 delete _oop_map_cache;
2450 _oop_map_cache = NULL;
2451 }
2452
2453 // Deallocate JNI identifiers for jfieldIDs
2454 JNIid::deallocate(jni_ids());
2455 set_jni_ids(NULL);
2456
2457 jmethodID* jmeths = methods_jmethod_ids_acquire();
2458 if (jmeths != (jmethodID*)NULL) {
2459 release_set_methods_jmethod_ids(NULL);
2460 FreeHeap(jmeths);
2461 }
2462
2463 // Deallocate MemberNameTable
2464 {
2465 Mutex* lock_or_null = SafepointSynchronize::is_at_safepoint() ? NULL : MemberNameTable_lock;
2466 MutexLockerEx ml(lock_or_null, Mutex::_no_safepoint_check_flag);
2467 MemberNameTable* mnt = member_names();
2468 if (mnt != NULL) {
2469 delete mnt;
2470 set_member_names(NULL);
2471 }
2472 }
2473
2474 // release dependencies
2475 nmethodBucket* b = _dependencies;
2476 _dependencies = NULL;
2477 while (b != NULL) {
2478 nmethodBucket* next = b->next();
2479 delete b;
2480 b = next;
2481 }
2482
2483 // Deallocate breakpoint records
2484 if (breakpoints() != 0x0) {
2485 methods_do(clear_all_breakpoints);
2486 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2487 }
2488
2489 // deallocate the cached class file
2490 if (_cached_class_file != NULL) {
2491 os::free(_cached_class_file);
2492 _cached_class_file = NULL;
2493 }
2494
2495 // Decrement symbol reference counts associated with the unloaded class.
2496 if (_name != NULL) _name->decrement_refcount();
2497 // unreference array name derived from this class name (arrays of an unloaded
2498 // class can't be referenced anymore).
2499 if (_array_name != NULL) _array_name->decrement_refcount();
2500 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2501
2502 assert(_total_instanceKlass_count >= 1, "Sanity check");
2503 Atomic::dec(&_total_instanceKlass_count);
2504 }
2505
2506 void InstanceKlass::set_source_debug_extension(char* array, int length) {
2507 if (array == NULL) {
2508 _source_debug_extension = NULL;
2509 } else {
2510 // Adding one to the attribute length in order to store a null terminator
2511 // character could cause an overflow because the attribute length is
2512 // already coded with an u4 in the classfile, but in practice, it's
2513 // unlikely to happen.
2514 assert((length+1) > length, "Overflow checking");
2515 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2516 for (int i = 0; i < length; i++) {
2517 sde[i] = array[i];
2518 }
2519 sde[length] = '\0';
2520 _source_debug_extension = sde;
2521 }
2522 }
2523
2524 address InstanceKlass::static_field_addr(int offset) {
2525 return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
2526 }
2527
2528
2529 const char* InstanceKlass::signature_name() const {
2530 int hash_len = 0;
2531 char hash_buf[40];
2532
2533 // If this is an anonymous class, append a hash to make the name unique
2534 if (is_anonymous()) {
2535 intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2536 jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2537 hash_len = (int)strlen(hash_buf);
2538 }
2539
2540 // Get the internal name as a c string
2541 const char* src = (const char*) (name()->as_C_string());
2542 const int src_length = (int)strlen(src);
2543
2544 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2545
2546 // Add L as type indicator
2547 int dest_index = 0;
2548 dest[dest_index++] = 'L';
2549
2550 // Add the actual class name
2551 for (int src_index = 0; src_index < src_length; ) {
2552 dest[dest_index++] = src[src_index++];
2553 }
2554
2555 // If we have a hash, append it
2556 for (int hash_index = 0; hash_index < hash_len; ) {
2557 dest[dest_index++] = hash_buf[hash_index++];
2558 }
2559
2560 // Add the semicolon and the NULL
2561 dest[dest_index++] = ';';
2562 dest[dest_index] = '\0';
2563 return dest;
2564 }
2565
2566 // different verisons of is_same_class_package
2567 bool InstanceKlass::is_same_class_package(Klass* class2) {
2568 Klass* class1 = this;
2569 oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2570 Symbol* classname1 = class1->name();
2571
2572 if (class2->oop_is_objArray()) {
2573 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2574 }
2575 oop classloader2;
2576 if (class2->oop_is_instance()) {
2577 classloader2 = InstanceKlass::cast(class2)->class_loader();
2578 } else {
2579 assert(class2->oop_is_typeArray(), "should be type array");
2580 classloader2 = NULL;
2581 }
2582 Symbol* classname2 = class2->name();
2583
2584 return InstanceKlass::is_same_class_package(classloader1, classname1,
2585 classloader2, classname2);
2586 }
2587
2588 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
2589 Klass* class1 = this;
2590 oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2591 Symbol* classname1 = class1->name();
2592
2593 return InstanceKlass::is_same_class_package(classloader1, classname1,
2594 classloader2, classname2);
2595 }
2596
2597 // return true if two classes are in the same package, classloader
2598 // and classname information is enough to determine a class's package
2599 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
2600 oop class_loader2, Symbol* class_name2) {
2601 if (class_loader1 != class_loader2) {
2602 return false;
2603 } else if (class_name1 == class_name2) {
2604 return true; // skip painful bytewise comparison
2605 } else {
2606 ResourceMark rm;
2607
2608 // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
2609 // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
2610 // Otherwise, we just compare jbyte values between the strings.
2611 const jbyte *name1 = class_name1->base();
2612 const jbyte *name2 = class_name2->base();
2613
2614 const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
2615 const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
2616
2617 if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
2618 // One of the two doesn't have a package. Only return true
2619 // if the other one also doesn't have a package.
2620 return last_slash1 == last_slash2;
2621 } else {
2622 // Skip over '['s
2623 if (*name1 == '[') {
2624 do {
2625 name1++;
2626 } while (*name1 == '[');
2627 if (*name1 != 'L') {
2628 // Something is terribly wrong. Shouldn't be here.
2629 return false;
2630 }
2631 }
2632 if (*name2 == '[') {
2633 do {
2634 name2++;
2635 } while (*name2 == '[');
2636 if (*name2 != 'L') {
2637 // Something is terribly wrong. Shouldn't be here.
2638 return false;
2639 }
2640 }
2641
2642 // Check that package part is identical
2643 int length1 = last_slash1 - name1;
2644 int length2 = last_slash2 - name2;
2645
2646 return UTF8::equal(name1, length1, name2, length2);
2647 }
2648 }
2649 }
2650
2651 // Returns true iff super_method can be overridden by a method in targetclassname
2652 // See JSL 3rd edition 8.4.6.1
2653 // Assumes name-signature match
2654 // "this" is InstanceKlass of super_method which must exist
2655 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2656 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2657 // Private methods can not be overridden
2658 if (super_method->is_private()) {
2659 return false;
2660 }
2661 // If super method is accessible, then override
2662 if ((super_method->is_protected()) ||
2663 (super_method->is_public())) {
2664 return true;
2665 }
2666 // Package-private methods are not inherited outside of package
2667 assert(super_method->is_package_private(), "must be package private");
2668 return(is_same_class_package(targetclassloader(), targetclassname));
2669 }
2670
2671 /* defined for now in jvm.cpp, for historical reasons *--
2672 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2673 Symbol*& simple_name_result, TRAPS) {
2674 ...
2675 }
2676 */
2677
2678 // tell if two classes have the same enclosing class (at package level)
2679 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2680 Klass* class2_oop, TRAPS) {
2681 if (class2_oop == class1()) return true;
2682 if (!class2_oop->oop_is_instance()) return false;
2683 instanceKlassHandle class2(THREAD, class2_oop);
2684
2685 // must be in same package before we try anything else
2686 if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2687 return false;
2688
2689 // As long as there is an outer1.getEnclosingClass,
2690 // shift the search outward.
2691 instanceKlassHandle outer1 = class1;
2692 for (;;) {
2693 // As we walk along, look for equalities between outer1 and class2.
2694 // Eventually, the walks will terminate as outer1 stops
2695 // at the top-level class around the original class.
2696 bool ignore_inner_is_member;
2697 Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2698 CHECK_false);
2699 if (next == NULL) break;
2700 if (next == class2()) return true;
2701 outer1 = instanceKlassHandle(THREAD, next);
2702 }
2703
2704 // Now do the same for class2.
2705 instanceKlassHandle outer2 = class2;
2706 for (;;) {
2707 bool ignore_inner_is_member;
2708 Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2709 CHECK_false);
2710 if (next == NULL) break;
2711 // Might as well check the new outer against all available values.
2712 if (next == class1()) return true;
2713 if (next == outer1()) return true;
2714 outer2 = instanceKlassHandle(THREAD, next);
2715 }
2716
2717 // If by this point we have not found an equality between the
2718 // two classes, we know they are in separate package members.
2719 return false;
2720 }
2721
2722 bool InstanceKlass::find_inner_classes_attr(instanceKlassHandle k, int* ooff, int* noff, TRAPS) {
2723 constantPoolHandle i_cp(THREAD, k->constants());
2724 for (InnerClassesIterator iter(k); !iter.done(); iter.next()) {
2725 int ioff = iter.inner_class_info_index();
2726 if (ioff != 0) {
2727 // Check to see if the name matches the class we're looking for
2728 // before attempting to find the class.
2729 if (i_cp->klass_name_at_matches(k, ioff)) {
2730 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2731 if (k() == inner_klass) {
2732 *ooff = iter.outer_class_info_index();
2733 *noff = iter.inner_name_index();
2734 return true;
2735 }
2736 }
2737 }
2738 }
2739 return false;
2740 }
2741
2742 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle k, bool* inner_is_member, TRAPS) {
2743 instanceKlassHandle outer_klass;
2744 *inner_is_member = false;
2745 int ooff = 0, noff = 0;
2746 if (find_inner_classes_attr(k, &ooff, &noff, THREAD)) {
2747 constantPoolHandle i_cp(THREAD, k->constants());
2748 if (ooff != 0) {
2749 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2750 outer_klass = instanceKlassHandle(THREAD, ok);
2751 *inner_is_member = true;
2752 }
2753 if (outer_klass.is_null()) {
2754 // It may be anonymous; try for that.
2755 int encl_method_class_idx = k->enclosing_method_class_index();
2756 if (encl_method_class_idx != 0) {
2757 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2758 outer_klass = instanceKlassHandle(THREAD, ok);
2759 *inner_is_member = false;
2760 }
2761 }
2762 }
2763
2764 // If no inner class attribute found for this class.
2765 if (outer_klass.is_null()) return NULL;
2766
2767 // Throws an exception if outer klass has not declared k as an inner klass
2768 // We need evidence that each klass knows about the other, or else
2769 // the system could allow a spoof of an inner class to gain access rights.
2770 Reflection::check_for_inner_class(outer_klass, k, *inner_is_member, CHECK_NULL);
2771 return outer_klass();
2772 }
2773
2774 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2775 jint access = access_flags().as_int();
2776
2777 // But check if it happens to be member class.
2778 instanceKlassHandle ik(THREAD, this);
2779 InnerClassesIterator iter(ik);
2780 for (; !iter.done(); iter.next()) {
2781 int ioff = iter.inner_class_info_index();
2782 // Inner class attribute can be zero, skip it.
2783 // Strange but true: JVM spec. allows null inner class refs.
2784 if (ioff == 0) continue;
2785
2786 // only look at classes that are already loaded
2787 // since we are looking for the flags for our self.
2788 Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2789 if ((ik->name() == inner_name)) {
2790 // This is really a member class.
2791 access = iter.inner_access_flags();
2792 break;
2793 }
2794 }
2795 // Remember to strip ACC_SUPER bit
2796 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2797 }
2798
2799 jint InstanceKlass::jvmti_class_status() const {
2800 jint result = 0;
2801
2802 if (is_linked()) {
2803 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2804 }
2805
2806 if (is_initialized()) {
2807 assert(is_linked(), "Class status is not consistent");
2808 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2809 }
2810 if (is_in_error_state()) {
2811 result |= JVMTI_CLASS_STATUS_ERROR;
2812 }
2813 return result;
2814 }
2815
2816 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2817 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2818 int method_table_offset_in_words = ioe->offset()/wordSize;
2819 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2820 / itableOffsetEntry::size();
2821
2822 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2823 // If the interface isn't implemented by the receiver class,
2824 // the VM should throw IncompatibleClassChangeError.
2825 if (cnt >= nof_interfaces) {
2826 THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2827 }
2828
2829 Klass* ik = ioe->interface_klass();
2830 if (ik == holder) break;
2831 }
2832
2833 itableMethodEntry* ime = ioe->first_method_entry(this);
2834 Method* m = ime[index].method();
2835 if (m == NULL) {
2836 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2837 }
2838 return m;
2839 }
2840
2841
2842 #if INCLUDE_JVMTI
2843 // update default_methods for redefineclasses for methods that are
2844 // not yet in the vtable due to concurrent subclass define and superinterface
2845 // redefinition
2846 // Note: those in the vtable, should have been updated via adjust_method_entries
2847 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2848 // search the default_methods for uses of either obsolete or EMCP methods
2849 if (default_methods() != NULL) {
2850 for (int index = 0; index < default_methods()->length(); index ++) {
2851 Method* old_method = default_methods()->at(index);
2852 if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2853 continue; // skip uninteresting entries
2854 }
2855 assert(!old_method->is_deleted(), "default methods may not be deleted");
2856
2857 Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2858
2859 assert(new_method != NULL, "method_with_idnum() should not be NULL");
2860 assert(old_method != new_method, "sanity check");
2861
2862 default_methods()->at_put(index, new_method);
2863 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
2864 if (!(*trace_name_printed)) {
2865 // RC_TRACE_MESG macro has an embedded ResourceMark
2866 RC_TRACE_MESG(("adjust: klassname=%s default methods from name=%s",
2867 external_name(),
2868 old_method->method_holder()->external_name()));
2869 *trace_name_printed = true;
2870 }
2871 RC_TRACE(0x00100000, ("default method update: %s(%s) ",
2872 new_method->name()->as_C_string(),
2873 new_method->signature()->as_C_string()));
2874 }
2875 }
2876 }
2877 }
2878 #endif // INCLUDE_JVMTI
2879
2880 // On-stack replacement stuff
2881 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2882 // only one compilation can be active
2883 {
2884 // This is a short non-blocking critical region, so the no safepoint check is ok.
2885 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2886 assert(n->is_osr_method(), "wrong kind of nmethod");
2887 n->set_osr_link(osr_nmethods_head());
2888 set_osr_nmethods_head(n);
2889 // Raise the highest osr level if necessary
2890 if (TieredCompilation) {
2891 Method* m = n->method();
2892 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2893 }
2894 }
2895
2896 // Get rid of the osr methods for the same bci that have lower levels.
2897 if (TieredCompilation) {
2898 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2899 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2900 if (inv != NULL && inv->is_in_use()) {
2901 inv->make_not_entrant();
2902 }
2903 }
2904 }
2905 }
2906
2907
2908 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
2909 // This is a short non-blocking critical region, so the no safepoint check is ok.
2910 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2911 assert(n->is_osr_method(), "wrong kind of nmethod");
2912 nmethod* last = NULL;
2913 nmethod* cur = osr_nmethods_head();
2914 int max_level = CompLevel_none; // Find the max comp level excluding n
2915 Method* m = n->method();
2916 // Search for match
2917 while(cur != NULL && cur != n) {
2918 if (TieredCompilation && m == cur->method()) {
2919 // Find max level before n
2920 max_level = MAX2(max_level, cur->comp_level());
2921 }
2922 last = cur;
2923 cur = cur->osr_link();
2924 }
2925 nmethod* next = NULL;
2926 if (cur == n) {
2927 next = cur->osr_link();
2928 if (last == NULL) {
2929 // Remove first element
2930 set_osr_nmethods_head(next);
2931 } else {
2932 last->set_osr_link(next);
2933 }
2934 }
2935 n->set_osr_link(NULL);
2936 if (TieredCompilation) {
2937 cur = next;
2938 while (cur != NULL) {
2939 // Find max level after n
2940 if (m == cur->method()) {
2941 max_level = MAX2(max_level, cur->comp_level());
2942 }
2943 cur = cur->osr_link();
2944 }
2945 m->set_highest_osr_comp_level(max_level);
2946 }
2947 }
2948
2949 int InstanceKlass::mark_osr_nmethods(const Method* m) {
2950 // This is a short non-blocking critical region, so the no safepoint check is ok.
2951 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2952 nmethod* osr = osr_nmethods_head();
2953 int found = 0;
2954 while (osr != NULL) {
2955 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2956 if (osr->method() == m) {
2957 osr->mark_for_deoptimization();
2958 found++;
2959 }
2960 osr = osr->osr_link();
2961 }
2962 return found;
2963 }
2964
2965 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2966 // This is a short non-blocking critical region, so the no safepoint check is ok.
2967 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2968 nmethod* osr = osr_nmethods_head();
2969 nmethod* best = NULL;
2970 while (osr != NULL) {
2971 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2972 // There can be a time when a c1 osr method exists but we are waiting
2973 // for a c2 version. When c2 completes its osr nmethod we will trash
2974 // the c1 version and only be able to find the c2 version. However
2975 // while we overflow in the c1 code at back branches we don't want to
2976 // try and switch to the same code as we are already running
2977
2978 if (osr->method() == m &&
2979 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2980 if (match_level) {
2981 if (osr->comp_level() == comp_level) {
2982 // Found a match - return it.
2983 return osr;
2984 }
2985 } else {
2986 if (best == NULL || (osr->comp_level() > best->comp_level())) {
2987 if (osr->comp_level() == CompLevel_highest_tier) {
2988 // Found the best possible - return it.
2989 return osr;
2990 }
2991 best = osr;
2992 }
2993 }
2994 }
2995 osr = osr->osr_link();
2996 }
2997 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2998 return best;
2999 }
3000 return NULL;
3001 }
3002
3003 bool InstanceKlass::add_member_name(Handle mem_name) {
3004 jweak mem_name_wref = JNIHandles::make_weak_global(mem_name);
3005 MutexLocker ml(MemberNameTable_lock);
3006 DEBUG_ONLY(No_Safepoint_Verifier nsv);
3007
3008 // Check if method has been redefined while taking out MemberNameTable_lock, if so
3009 // return false. We cannot cache obsolete methods. They will crash when the function
3010 // is called!
3011 Method* method = (Method*)java_lang_invoke_MemberName::vmtarget(mem_name());
3012 if (method->is_obsolete()) {
3013 return false;
3014 } else if (method->is_old()) {
3015 // Replace method with redefined version
3016 java_lang_invoke_MemberName::set_vmtarget(mem_name(), method_with_idnum(method->method_idnum()));
3017 }
3018
3019 if (_member_names == NULL) {
3020 _member_names = new (ResourceObj::C_HEAP, mtClass) MemberNameTable(idnum_allocated_count());
3021 }
3022 _member_names->add_member_name(mem_name_wref);
3023 return true;
3024 }
3025
3026 // -----------------------------------------------------------------------------------------------------
3027 // Printing
3028
3029 #ifndef PRODUCT
3030
3031 #define BULLET " - "
3032
3033 static const char* state_names[] = {
3034 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3035 };
3036
3037 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3038 for (int i = 0; i < len; i++) {
3039 intptr_t e = start[i];
3040 st->print("%d : " INTPTR_FORMAT, i, e);
3041 if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
3042 st->print(" ");
3043 ((Metadata*)e)->print_value_on(st);
3044 }
3045 st->cr();
3046 }
3047 }
3048
3049 void InstanceKlass::print_on(outputStream* st) const {
3050 assert(is_klass(), "must be klass");
3051 Klass::print_on(st);
3052
3053 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3054 st->print(BULLET"klass size: %d", size()); st->cr();
3055 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3056 st->print(BULLET"state: "); st->print_cr("%s", state_names[_init_state]);
3057 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3058 st->print(BULLET"super: "); super()->print_value_on_maybe_null(st); st->cr();
3059 st->print(BULLET"sub: ");
3060 Klass* sub = subklass();
3061 int n;
3062 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
3063 if (n < MaxSubklassPrintSize) {
3064 sub->print_value_on(st);
3065 st->print(" ");
3066 }
3067 }
3068 if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
3069 st->cr();
3070
3071 if (is_interface()) {
3072 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3073 if (nof_implementors() == 1) {
3074 st->print_cr(BULLET"implementor: ");
3075 st->print(" ");
3076 implementor()->print_value_on(st);
3077 st->cr();
3078 }
3079 }
3080
3081 st->print(BULLET"arrays: "); array_klasses()->print_value_on_maybe_null(st); st->cr();
3082 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3083 if (Verbose || WizardMode) {
3084 Array<Method*>* method_array = methods();
3085 for (int i = 0; i < method_array->length(); i++) {
3086 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3087 }
3088 }
3089 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3090 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3091 if (Verbose && default_methods() != NULL) {
3092 Array<Method*>* method_array = default_methods();
3093 for (int i = 0; i < method_array->length(); i++) {
3094 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3095 }
3096 }
3097 if (default_vtable_indices() != NULL) {
3098 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
3099 }
3100 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3101 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3102 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3103 if (class_loader_data() != NULL) {
3104 st->print(BULLET"class loader data: ");
3105 class_loader_data()->print_value_on(st);
3106 st->cr();
3107 }
3108 st->print(BULLET"host class: "); host_klass()->print_value_on_maybe_null(st); st->cr();
3109 if (source_file_name() != NULL) {
3110 st->print(BULLET"source file: ");
3111 source_file_name()->print_value_on(st);
3112 st->cr();
3113 }
3114 if (source_debug_extension() != NULL) {
3115 st->print(BULLET"source debug extension: ");
3116 st->print("%s", source_debug_extension());
3117 st->cr();
3118 }
3119 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
3120 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
3121 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
3122 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
3123 {
3124 bool have_pv = false;
3125 // previous versions are linked together through the InstanceKlass
3126 for (InstanceKlass* pv_node = _previous_versions;
3127 pv_node != NULL;
3128 pv_node = pv_node->previous_versions()) {
3129 if (!have_pv)
3130 st->print(BULLET"previous version: ");
3131 have_pv = true;
3132 pv_node->constants()->print_value_on(st);
3133 }
3134 if (have_pv) st->cr();
3135 }
3136
3137 if (generic_signature() != NULL) {
3138 st->print(BULLET"generic signature: ");
3139 generic_signature()->print_value_on(st);
3140 st->cr();
3141 }
3142 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3143 st->print(BULLET"java mirror: "); java_mirror()->print_value_on(st); st->cr();
3144 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable()); st->cr();
3145 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3146 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
3147 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3148 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3149 FieldPrinter print_static_field(st);
3150 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3151 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3152 FieldPrinter print_nonstatic_field(st);
3153 ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
3154
3155 st->print(BULLET"non-static oop maps: ");
3156 OopMapBlock* map = start_of_nonstatic_oop_maps();
3157 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3158 while (map < end_map) {
3159 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3160 map++;
3161 }
3162 st->cr();
3163 }
3164
3165 #endif //PRODUCT
3166
3167 void InstanceKlass::print_value_on(outputStream* st) const {
3168 assert(is_klass(), "must be klass");
3169 if (Verbose || WizardMode) access_flags().print_on(st);
3170 name()->print_value_on(st);
3171 }
3172
3173 #ifndef PRODUCT
3174
3175 void FieldPrinter::do_field(fieldDescriptor* fd) {
3176 _st->print(BULLET);
3177 if (_obj == NULL) {
3178 fd->print_on(_st);
3179 _st->cr();
3180 } else {
3181 fd->print_on_for(_st, _obj);
3182 _st->cr();
3183 }
3184 }
3185
3186
3187 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3188 Klass::oop_print_on(obj, st);
3189
3190 if (this == SystemDictionary::String_klass()) {
3191 typeArrayOop value = java_lang_String::value(obj);
3192 juint offset = java_lang_String::offset(obj);
3193 juint length = java_lang_String::length(obj);
3194 if (value != NULL &&
3195 value->is_typeArray() &&
3196 offset <= (juint) value->length() &&
3197 offset + length <= (juint) value->length()) {
3198 st->print(BULLET"string: ");
3199 java_lang_String::print(obj, st);
3200 st->cr();
3201 if (!WizardMode) return; // that is enough
3202 }
3203 }
3204
3205 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3206 FieldPrinter print_field(st, obj);
3207 do_nonstatic_fields(&print_field);
3208
3209 if (this == SystemDictionary::Class_klass()) {
3210 st->print(BULLET"signature: ");
3211 java_lang_Class::print_signature(obj, st);
3212 st->cr();
3213 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3214 st->print(BULLET"fake entry for mirror: ");
3215 mirrored_klass->print_value_on_maybe_null(st);
3216 st->cr();
3217 Klass* array_klass = java_lang_Class::array_klass(obj);
3218 st->print(BULLET"fake entry for array: ");
3219 array_klass->print_value_on_maybe_null(st);
3220 st->cr();
3221 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3222 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3223 Klass* real_klass = java_lang_Class::as_Klass(obj);
3224 if (real_klass != NULL && real_klass->oop_is_instance()) {
3225 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3226 }
3227 } else if (this == SystemDictionary::MethodType_klass()) {
3228 st->print(BULLET"signature: ");
3229 java_lang_invoke_MethodType::print_signature(obj, st);
3230 st->cr();
3231 }
3232 }
3233
3234 #endif //PRODUCT
3235
3236 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3237 st->print("a ");
3238 name()->print_value_on(st);
3239 obj->print_address_on(st);
3240 if (this == SystemDictionary::String_klass()
3241 && java_lang_String::value(obj) != NULL) {
3242 ResourceMark rm;
3243 int len = java_lang_String::length(obj);
3244 int plen = (len < 24 ? len : 12);
3245 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3246 st->print(" = \"%s\"", str);
3247 if (len > plen)
3248 st->print("...[%d]", len);
3249 } else if (this == SystemDictionary::Class_klass()) {
3250 Klass* k = java_lang_Class::as_Klass(obj);
3251 st->print(" = ");
3252 if (k != NULL) {
3253 k->print_value_on(st);
3254 } else {
3255 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3256 st->print("%s", tname ? tname : "type?");
3257 }
3258 } else if (this == SystemDictionary::MethodType_klass()) {
3259 st->print(" = ");
3260 java_lang_invoke_MethodType::print_signature(obj, st);
3261 } else if (java_lang_boxing_object::is_instance(obj)) {
3262 st->print(" = ");
3263 java_lang_boxing_object::print(obj, st);
3264 } else if (this == SystemDictionary::LambdaForm_klass()) {
3265 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3266 if (vmentry != NULL) {
3267 st->print(" => ");
3268 vmentry->print_value_on(st);
3269 }
3270 } else if (this == SystemDictionary::MemberName_klass()) {
3271 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3272 if (vmtarget != NULL) {
3273 st->print(" = ");
3274 vmtarget->print_value_on(st);
3275 } else {
3276 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3277 st->print(".");
3278 java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3279 }
3280 }
3281 }
3282
3283 const char* InstanceKlass::internal_name() const {
3284 return external_name();
3285 }
3286
3287 #if INCLUDE_SERVICES
3288 // Size Statistics
3289 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3290 Klass::collect_statistics(sz);
3291
3292 sz->_inst_size = HeapWordSize * size_helper();
3293 sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
3294 sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
3295 sz->_nonstatic_oopmap_bytes = HeapWordSize *
3296 ((is_interface() || is_anonymous()) ?
3297 align_object_offset(nonstatic_oop_map_size()) :
3298 nonstatic_oop_map_size());
3299
3300 int n = 0;
3301 n += (sz->_methods_array_bytes = sz->count_array(methods()));
3302 n += (sz->_method_ordering_bytes = sz->count_array(method_ordering()));
3303 n += (sz->_local_interfaces_bytes = sz->count_array(local_interfaces()));
3304 n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3305 n += (sz->_fields_bytes = sz->count_array(fields()));
3306 n += (sz->_inner_classes_bytes = sz->count_array(inner_classes()));
3307 sz->_ro_bytes += n;
3308
3309 const ConstantPool* cp = constants();
3310 if (cp) {
3311 cp->collect_statistics(sz);
3312 }
3313
3314 const Annotations* anno = annotations();
3315 if (anno) {
3316 anno->collect_statistics(sz);
3317 }
3318
3319 const Array<Method*>* methods_array = methods();
3320 if (methods()) {
3321 for (int i = 0; i < methods_array->length(); i++) {
3322 Method* method = methods_array->at(i);
3323 if (method) {
3324 sz->_method_count ++;
3325 method->collect_statistics(sz);
3326 }
3327 }
3328 }
3329 }
3330 #endif // INCLUDE_SERVICES
3331
3332 // Verification
3333
3334 class VerifyFieldClosure: public OopClosure {
3335 protected:
3336 template <class T> void do_oop_work(T* p) {
3337 oop obj = oopDesc::load_decode_heap_oop(p);
3338 if (!obj->is_oop_or_null()) {
3339 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
3340 Universe::print();
3341 guarantee(false, "boom");
3342 }
3343 }
3344 public:
3345 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3346 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3347 };
3348
3349 void InstanceKlass::verify_on(outputStream* st) {
3350 #ifndef PRODUCT
3351 // Avoid redundant verifies, this really should be in product.
3352 if (_verify_count == Universe::verify_count()) return;
3353 _verify_count = Universe::verify_count();
3354 #endif
3355
3356 // Verify Klass
3357 Klass::verify_on(st);
3358
3359 // Verify that klass is present in ClassLoaderData
3360 guarantee(class_loader_data()->contains_klass(this),
3361 "this class isn't found in class loader data");
3362
3363 // Verify vtables
3364 if (is_linked()) {
3365 ResourceMark rm;
3366 // $$$ This used to be done only for m/s collections. Doing it
3367 // always seemed a valid generalization. (DLD -- 6/00)
3368 vtable()->verify(st);
3369 }
3370
3371 // Verify first subklass
3372 if (subklass() != NULL) {
3373 guarantee(subklass()->is_klass(), "should be klass");
3374 }
3375
3376 // Verify siblings
3377 Klass* super = this->super();
3378 Klass* sib = next_sibling();
3379 if (sib != NULL) {
3380 if (sib == this) {
3381 fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
3382 }
3383
3384 guarantee(sib->is_klass(), "should be klass");
3385 guarantee(sib->super() == super, "siblings should have same superklass");
3386 }
3387
3388 // Verify implementor fields
3389 Klass* im = implementor();
3390 if (im != NULL) {
3391 guarantee(is_interface(), "only interfaces should have implementor set");
3392 guarantee(im->is_klass(), "should be klass");
3393 guarantee(!im->is_interface() || im == this,
3394 "implementors cannot be interfaces");
3395 }
3396
3397 // Verify local interfaces
3398 if (local_interfaces()) {
3399 Array<Klass*>* local_interfaces = this->local_interfaces();
3400 for (int j = 0; j < local_interfaces->length(); j++) {
3401 Klass* e = local_interfaces->at(j);
3402 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3403 }
3404 }
3405
3406 // Verify transitive interfaces
3407 if (transitive_interfaces() != NULL) {
3408 Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3409 for (int j = 0; j < transitive_interfaces->length(); j++) {
3410 Klass* e = transitive_interfaces->at(j);
3411 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3412 }
3413 }
3414
3415 // Verify methods
3416 if (methods() != NULL) {
3417 Array<Method*>* methods = this->methods();
3418 for (int j = 0; j < methods->length(); j++) {
3419 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3420 }
3421 for (int j = 0; j < methods->length() - 1; j++) {
3422 Method* m1 = methods->at(j);
3423 Method* m2 = methods->at(j + 1);
3424 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3425 }
3426 }
3427
3428 // Verify method ordering
3429 if (method_ordering() != NULL) {
3430 Array<int>* method_ordering = this->method_ordering();
3431 int length = method_ordering->length();
3432 if (JvmtiExport::can_maintain_original_method_order() ||
3433 ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3434 guarantee(length == methods()->length(), "invalid method ordering length");
3435 jlong sum = 0;
3436 for (int j = 0; j < length; j++) {
3437 int original_index = method_ordering->at(j);
3438 guarantee(original_index >= 0, "invalid method ordering index");
3439 guarantee(original_index < length, "invalid method ordering index");
3440 sum += original_index;
3441 }
3442 // Verify sum of indices 0,1,...,length-1
3443 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3444 } else {
3445 guarantee(length == 0, "invalid method ordering length");
3446 }
3447 }
3448
3449 // Verify default methods
3450 if (default_methods() != NULL) {
3451 Array<Method*>* methods = this->default_methods();
3452 for (int j = 0; j < methods->length(); j++) {
3453 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3454 }
3455 for (int j = 0; j < methods->length() - 1; j++) {
3456 Method* m1 = methods->at(j);
3457 Method* m2 = methods->at(j + 1);
3458 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3459 }
3460 }
3461
3462 // Verify JNI static field identifiers
3463 if (jni_ids() != NULL) {
3464 jni_ids()->verify(this);
3465 }
3466
3467 // Verify other fields
3468 if (array_klasses() != NULL) {
3469 guarantee(array_klasses()->is_klass(), "should be klass");
3470 }
3471 if (constants() != NULL) {
3472 guarantee(constants()->is_constantPool(), "should be constant pool");
3473 }
3474 const Klass* host = host_klass();
3475 if (host != NULL) {
3476 guarantee(host->is_klass(), "should be klass");
3477 }
3478 }
3479
3480 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3481 Klass::oop_verify_on(obj, st);
3482 VerifyFieldClosure blk;
3483 obj->oop_iterate_no_header(&blk);
3484 }
3485
3486
3487 // JNIid class for jfieldIDs only
3488 // Note to reviewers:
3489 // These JNI functions are just moved over to column 1 and not changed
3490 // in the compressed oops workspace.
3491 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3492 _holder = holder;
3493 _offset = offset;
3494 _next = next;
3495 debug_only(_is_static_field_id = false;)
3496 }
3497
3498
3499 JNIid* JNIid::find(int offset) {
3500 JNIid* current = this;
3501 while (current != NULL) {
3502 if (current->offset() == offset) return current;
3503 current = current->next();
3504 }
3505 return NULL;
3506 }
3507
3508 void JNIid::deallocate(JNIid* current) {
3509 while (current != NULL) {
3510 JNIid* next = current->next();
3511 delete current;
3512 current = next;
3513 }
3514 }
3515
3516
3517 void JNIid::verify(Klass* holder) {
3518 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3519 int end_field_offset;
3520 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3521
3522 JNIid* current = this;
3523 while (current != NULL) {
3524 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3525 #ifdef ASSERT
3526 int o = current->offset();
3527 if (current->is_static_field_id()) {
3528 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3529 }
3530 #endif
3531 current = current->next();
3532 }
3533 }
3534
3535
3536 #ifdef ASSERT
3537 void InstanceKlass::set_init_state(ClassState state) {
3538 bool good_state = is_shared() ? (_init_state <= state)
3539 : (_init_state < state);
3540 assert(good_state || state == allocated, "illegal state transition");
3541 _init_state = (u1)state;
3542 }
3543 #endif
3544
3545
3546
3547 // RedefineClasses() support for previous versions:
3548 int InstanceKlass::_previous_version_count = 0;
3549
3550 // Purge previous versions before adding new previous versions of the class.
3551 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
3552 if (ik->previous_versions() != NULL) {
3553 // This klass has previous versions so see what we can cleanup
3554 // while it is safe to do so.
3555
3556 int deleted_count = 0; // leave debugging breadcrumbs
3557 int live_count = 0;
3558 ClassLoaderData* loader_data = ik->class_loader_data();
3559 assert(loader_data != NULL, "should never be null");
3560
3561 // RC_TRACE macro has an embedded ResourceMark
3562 RC_TRACE(0x00000200, ("purge: %s: previous versions", ik->external_name()));
3563
3564 // previous versions are linked together through the InstanceKlass
3565 InstanceKlass* pv_node = ik->previous_versions();
3566 InstanceKlass* last = ik;
3567 int version = 0;
3568
3569 // check the previous versions list
3570 for (; pv_node != NULL; ) {
3571
3572 ConstantPool* pvcp = pv_node->constants();
3573 assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3574
3575 if (!pvcp->on_stack()) {
3576 // If the constant pool isn't on stack, none of the methods
3577 // are executing. Unlink this previous_version.
3578 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3579 // so will be deallocated during the next phase of class unloading.
3580 RC_TRACE(0x00000200, ("purge: previous version " INTPTR_FORMAT " is dead",
3581 pv_node));
3582 // For debugging purposes.
3583 pv_node->set_is_scratch_class();
3584 pv_node->class_loader_data()->add_to_deallocate_list(pv_node);
3585 pv_node = pv_node->previous_versions();
3586 last->link_previous_versions(pv_node);
3587 deleted_count++;
3588 version++;
3589 continue;
3590 } else {
3591 RC_TRACE(0x00000200, ("purge: previous version " INTPTR_FORMAT " is alive",
3592 pv_node));
3593 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3594 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3595 live_count++;
3596 }
3597
3598 // At least one method is live in this previous version.
3599 // Reset dead EMCP methods not to get breakpoints.
3600 // All methods are deallocated when all of the methods for this class are no
3601 // longer running.
3602 Array<Method*>* method_refs = pv_node->methods();
3603 if (method_refs != NULL) {
3604 RC_TRACE(0x00000200, ("purge: previous methods length=%d",
3605 method_refs->length()));
3606 for (int j = 0; j < method_refs->length(); j++) {
3607 Method* method = method_refs->at(j);
3608
3609 if (!method->on_stack()) {
3610 // no breakpoints for non-running methods
3611 if (method->is_running_emcp()) {
3612 method->set_running_emcp(false);
3613 }
3614 } else {
3615 assert (method->is_obsolete() || method->is_running_emcp(),
3616 "emcp method cannot run after emcp bit is cleared");
3617 // RC_TRACE macro has an embedded ResourceMark
3618 RC_TRACE(0x00000200,
3619 ("purge: %s(%s): prev method @%d in version @%d is alive",
3620 method->name()->as_C_string(),
3621 method->signature()->as_C_string(), j, version));
3622 }
3623 }
3624 }
3625 // next previous version
3626 last = pv_node;
3627 pv_node = pv_node->previous_versions();
3628 version++;
3629 }
3630 RC_TRACE(0x00000200,
3631 ("purge: previous version stats: live=%d, deleted=%d", live_count,
3632 deleted_count));
3633 }
3634 }
3635
3636 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3637 int emcp_method_count) {
3638 int obsolete_method_count = old_methods->length() - emcp_method_count;
3639
3640 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3641 _previous_versions != NULL) {
3642 // We have a mix of obsolete and EMCP methods so we have to
3643 // clear out any matching EMCP method entries the hard way.
3644 int local_count = 0;
3645 for (int i = 0; i < old_methods->length(); i++) {
3646 Method* old_method = old_methods->at(i);
3647 if (old_method->is_obsolete()) {
3648 // only obsolete methods are interesting
3649 Symbol* m_name = old_method->name();
3650 Symbol* m_signature = old_method->signature();
3651
3652 // previous versions are linked together through the InstanceKlass
3653 int j = 0;
3654 for (InstanceKlass* prev_version = _previous_versions;
3655 prev_version != NULL;
3656 prev_version = prev_version->previous_versions(), j++) {
3657
3658 Array<Method*>* method_refs = prev_version->methods();
3659 for (int k = 0; k < method_refs->length(); k++) {
3660 Method* method = method_refs->at(k);
3661
3662 if (!method->is_obsolete() &&
3663 method->name() == m_name &&
3664 method->signature() == m_signature) {
3665 // The current RedefineClasses() call has made all EMCP
3666 // versions of this method obsolete so mark it as obsolete
3667 RC_TRACE(0x00000400,
3668 ("add: %s(%s): flush obsolete method @%d in version @%d",
3669 m_name->as_C_string(), m_signature->as_C_string(), k, j));
3670
3671 method->set_is_obsolete();
3672 break;
3673 }
3674 }
3675
3676 // The previous loop may not find a matching EMCP method, but
3677 // that doesn't mean that we can optimize and not go any
3678 // further back in the PreviousVersion generations. The EMCP
3679 // method for this generation could have already been made obsolete,
3680 // but there still may be an older EMCP method that has not
3681 // been made obsolete.
3682 }
3683
3684 if (++local_count >= obsolete_method_count) {
3685 // no more obsolete methods so bail out now
3686 break;
3687 }
3688 }
3689 }
3690 }
3691 }
3692
3693 // Save the scratch_class as the previous version if any of the methods are running.
3694 // The previous_versions are used to set breakpoints in EMCP methods and they are
3695 // also used to clean MethodData links to redefined methods that are no longer running.
3696 void InstanceKlass::add_previous_version(instanceKlassHandle scratch_class,
3697 int emcp_method_count) {
3698 assert(Thread::current()->is_VM_thread(),
3699 "only VMThread can add previous versions");
3700
3701 // RC_TRACE macro has an embedded ResourceMark
3702 RC_TRACE(0x00000400, ("adding previous version ref for %s, EMCP_cnt=%d",
3703 scratch_class->external_name(), emcp_method_count));
3704
3705 // Clean out old previous versions
3706 purge_previous_versions(this);
3707
3708 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
3709 // a previous redefinition may be made obsolete by this redefinition.
3710 Array<Method*>* old_methods = scratch_class->methods();
3711 mark_newly_obsolete_methods(old_methods, emcp_method_count);
3712
3713 // If the constant pool for this previous version of the class
3714 // is not marked as being on the stack, then none of the methods
3715 // in this previous version of the class are on the stack so
3716 // we don't need to add this as a previous version.
3717 ConstantPool* cp_ref = scratch_class->constants();
3718 if (!cp_ref->on_stack()) {
3719 RC_TRACE(0x00000400, ("add: scratch class not added; no methods are running"));
3720 // For debugging purposes.
3721 scratch_class->set_is_scratch_class();
3722 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class());
3723 // Update count for class unloading.
3724 _previous_version_count--;
3725 return;
3726 }
3727
3728 if (emcp_method_count != 0) {
3729 // At least one method is still running, check for EMCP methods
3730 for (int i = 0; i < old_methods->length(); i++) {
3731 Method* old_method = old_methods->at(i);
3732 if (!old_method->is_obsolete() && old_method->on_stack()) {
3733 // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3734 // we can add breakpoints for it.
3735
3736 // We set the method->on_stack bit during safepoints for class redefinition
3737 // and use this bit to set the is_running_emcp bit.
3738 // After the safepoint, the on_stack bit is cleared and the running emcp
3739 // method may exit. If so, we would set a breakpoint in a method that
3740 // is never reached, but this won't be noticeable to the programmer.
3741 old_method->set_running_emcp(true);
3742 RC_TRACE(0x00000400, ("add: EMCP method %s is on_stack " INTPTR_FORMAT,
3743 old_method->name_and_sig_as_C_string(), old_method));
3744 } else if (!old_method->is_obsolete()) {
3745 RC_TRACE(0x00000400, ("add: EMCP method %s is NOT on_stack " INTPTR_FORMAT,
3746 old_method->name_and_sig_as_C_string(), old_method));
3747 }
3748 }
3749 }
3750
3751 // Add previous version if any methods are still running.
3752 RC_TRACE(0x00000400, ("add: scratch class added; one of its methods is on_stack"));
3753 assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3754 scratch_class->link_previous_versions(previous_versions());
3755 link_previous_versions(scratch_class());
3756 // Update count for class unloading.
3757 _previous_version_count++;
3758 } // end add_previous_version()
3759
3760
3761 Method* InstanceKlass::method_with_idnum(int idnum) {
3762 Method* m = NULL;
3763 if (idnum < methods()->length()) {
3764 m = methods()->at(idnum);
3765 }
3766 if (m == NULL || m->method_idnum() != idnum) {
3767 for (int index = 0; index < methods()->length(); ++index) {
3768 m = methods()->at(index);
3769 if (m->method_idnum() == idnum) {
3770 return m;
3771 }
3772 }
3773 // None found, return null for the caller to handle.
3774 return NULL;
3775 }
3776 return m;
3777 }
3778
3779 jint InstanceKlass::get_cached_class_file_len() {
3780 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3781 }
3782
3783 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3784 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3785 }