1 /*
2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jvm.h"
27 #include "aot/aotLoader.hpp"
28 #include "classfile/classFileParser.hpp"
29 #include "classfile/classFileStream.hpp"
30 #include "classfile/classLoader.hpp"
31 #include "classfile/javaClasses.hpp"
32 #include "classfile/moduleEntry.hpp"
33 #include "classfile/systemDictionary.hpp"
34 #include "classfile/systemDictionaryShared.hpp"
35 #include "classfile/verifier.hpp"
36 #include "classfile/vmSymbols.hpp"
37 #include "code/dependencyContext.hpp"
38 #include "compiler/compileBroker.hpp"
39 #include "gc/shared/collectedHeap.inline.hpp"
40 #include "gc/shared/specialized_oop_closures.hpp"
41 #include "interpreter/oopMapCache.hpp"
42 #include "interpreter/rewriter.hpp"
43 #include "jvmtifiles/jvmti.h"
44 #include "logging/log.hpp"
45 #include "logging/logMessage.hpp"
46 #include "logging/logStream.hpp"
47 #include "memory/heapInspection.hpp"
48 #include "memory/iterator.inline.hpp"
49 #include "memory/metadataFactory.hpp"
50 #include "memory/metaspaceClosure.hpp"
51 #include "memory/metaspaceShared.hpp"
52 #include "memory/oopFactory.hpp"
53 #include "memory/resourceArea.hpp"
54 #include "oops/fieldStreams.hpp"
55 #include "oops/instanceClassLoaderKlass.hpp"
56 #include "oops/instanceKlass.inline.hpp"
57 #include "oops/instanceMirrorKlass.hpp"
58 #include "oops/instanceOop.hpp"
59 #include "oops/klass.inline.hpp"
60 #include "oops/method.hpp"
61 #include "oops/oop.inline.hpp"
62 #include "oops/symbol.hpp"
63 #include "prims/jvmtiExport.hpp"
64 #include "prims/jvmtiRedefineClasses.hpp"
65 #include "prims/jvmtiThreadState.hpp"
66 #include "prims/methodComparator.hpp"
67 #include "runtime/atomic.hpp"
68 #include "runtime/fieldDescriptor.hpp"
69 #include "runtime/handles.inline.hpp"
70 #include "runtime/javaCalls.hpp"
71 #include "runtime/mutexLocker.hpp"
72 #include "runtime/orderAccess.inline.hpp"
73 #include "runtime/thread.inline.hpp"
74 #include "services/classLoadingService.hpp"
75 #include "services/threadService.hpp"
76 #include "utilities/dtrace.hpp"
77 #include "utilities/macros.hpp"
78 #include "utilities/stringUtils.hpp"
79 #ifdef COMPILER1
80 #include "c1/c1_Compiler.hpp"
81 #endif
82
83 #ifdef DTRACE_ENABLED
84
85
86 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
87 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
88 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
89 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
90 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
91 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
92 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
93 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
94 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
95 { \
96 char* data = NULL; \
97 int len = 0; \
98 Symbol* clss_name = name(); \
99 if (clss_name != NULL) { \
100 data = (char*)clss_name->bytes(); \
101 len = clss_name->utf8_length(); \
102 } \
103 HOTSPOT_CLASS_INITIALIZATION_##type( \
104 data, len, (void*)class_loader(), thread_type); \
105 }
106
107 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
108 { \
109 char* data = NULL; \
110 int len = 0; \
111 Symbol* clss_name = name(); \
112 if (clss_name != NULL) { \
113 data = (char*)clss_name->bytes(); \
114 len = clss_name->utf8_length(); \
115 } \
116 HOTSPOT_CLASS_INITIALIZATION_##type( \
117 data, len, (void*)class_loader(), thread_type, wait); \
118 }
119
120 #else // ndef DTRACE_ENABLED
121
122 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
123 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
124
125 #endif // ndef DTRACE_ENABLED
126
127 volatile int InstanceKlass::_total_instanceKlass_count = 0;
128
129 static inline bool is_class_loader(const Symbol* class_name,
130 const ClassFileParser& parser) {
131 assert(class_name != NULL, "invariant");
132
133 if (class_name == vmSymbols::java_lang_ClassLoader()) {
134 return true;
135 }
136
137 if (SystemDictionary::ClassLoader_klass_loaded()) {
138 const Klass* const super_klass = parser.super_klass();
139 if (super_klass != NULL) {
140 if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
141 return true;
142 }
143 }
144 }
145 return false;
146 }
147
148 // called to verify that k is a member of this nest
149 bool InstanceKlass::has_nest_member(InstanceKlass* k, TRAPS) const {
150 if (_nest_members == NULL || _nest_members == Universe::the_empty_short_array()) {
151 if (log_is_enabled(Trace, class, nestmates)) {
152 ResourceMark rm(THREAD);
153 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
154 k->external_name(), this->external_name());
155 }
156 return false;
157 }
158
159 if (log_is_enabled(Trace, class, nestmates)) {
160 ResourceMark rm(THREAD);
161 log_trace(class, nestmates)("Checking nest membership of %s in %s",
162 k->external_name(), this->external_name());
163 }
164
165 // Check names first and if they match then check actual klass. This avoids
166 // resolving anything unnecessarily.
167 for (int i = 0; i < _nest_members->length(); i++) {
168 int cp_index = _nest_members->at(i);
169 Symbol* name = _constants->klass_name_at(cp_index);
170 if (name == k->name()) {
171 log_trace(class, nestmates)("- Found it at nest_members[%d] => cp[%d]", i, cp_index);
172
173 // names match so check actual klass - this may trigger class loading if
174 // it doesn't match (but that should be impossible)
175 Klass* k2 = _constants->klass_at(cp_index, CHECK_false);
176 if (k2 == k) {
177 log_trace(class, nestmates)("- class is listed as a nest member");
178 return true;
179 }
180 else {
181 // same name but different klass!
182 log_trace(class, nestmates)(" - klass comparison failed!");
183 }
184 }
185 }
186 log_trace(class, nestmates)("- class is NOT a nest member!");
187 return false;
188 }
189
190 // Return nest-host class, resolving, validating and saving it if needed.
191 // In cases where this is called from a thread that can not do classloading
192 // (such as a native JIT thread) then we simply return NULL, which in turn
193 // causes the access check to return false. Such code will retry the access
194 // from a more suitable environment later.
195 InstanceKlass* InstanceKlass::nest_host(Symbol* validationException, TRAPS) {
196 InstanceKlass* nest_host_k = _nest_host;
197 if (nest_host_k == NULL) {
198 // need to resolve and save our nest-host class. This could be attempted
199 // concurrently but as the result is idempotent and we don't use the class
200 // then we do not need any synchronization beyond what is implicitly used
201 // during class loading.
202 if (_nest_host_index != 0) { // we have a real nest_host
203 // Before trying to resolve check if we're in a suitable context
204 if (!THREAD->can_call_java() && !_constants->tag_at(_nest_host_index).is_klass()) {
205 if (log_is_enabled(Trace, class, nestmates)) {
206 ResourceMark rm(THREAD);
207 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
208 this->external_name());
209 }
210 return NULL;
211 }
212
213 if (log_is_enabled(Trace, class, nestmates)) {
214 ResourceMark rm(THREAD);
215 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
216 this->external_name(),
217 _constants->klass_name_at(_nest_host_index)->as_C_string());
218 }
219
220 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
221 if (HAS_PENDING_EXCEPTION) {
222 Handle exc_h = Handle(THREAD, PENDING_EXCEPTION);
223 if (exc_h->is_a(SystemDictionary::NoClassDefFoundError_klass())) {
224 // throw a new CDNFE with the original as its cause, and a clear msg
225 ResourceMark rm(THREAD);
226 char buf[200];
227 CLEAR_PENDING_EXCEPTION;
228 jio_snprintf(buf, sizeof(buf),
229 "Unable to load nest-host class (%s) of %s",
230 _constants->klass_name_at(_nest_host_index)->as_C_string(),
231 this->external_name());
232 log_trace(class, nestmates)("%s - NoClassDefFoundError", buf);
233 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), buf, exc_h);
234 }
235 // other exceptions pass through (OOME, StackOverflowError etc)
236 return NULL;
237 }
238
239 // A valid nest-host is an instance class in the current package that lists this
240 // class as a nest member. If any of these conditions are not met we post the
241 // requested exception type (if any) and return NULL
242
243 const char* error = NULL;
244
245 // JVMS 5.4.4 indicates package check comes first
246 if (is_same_class_package(k)) {
247
248 // Now check actual membership. We can't be a member if our "host" is
249 // not an instance class.
250 if (k->is_instance_klass()) {
251 nest_host_k = InstanceKlass::cast(k);
252
253 // FIXME: an exception from this is perhaps impossible
254 bool is_member = nest_host_k->has_nest_member(this, CHECK_NULL);
255 if (is_member) {
256 // save resolved nest-host value
257 _nest_host = nest_host_k;
258
259 if (log_is_enabled(Trace, class, nestmates)) {
260 ResourceMark rm(THREAD);
261 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
262 this->external_name(), k->external_name());
263 }
264 return nest_host_k;
265 }
266 }
267 error = "current type is not listed as a nest member";
268 }
269 else {
270 error = "types are in different packages";
271 }
272
273 if (log_is_enabled(Trace, class, nestmates)) {
274 ResourceMark rm(THREAD);
275 log_trace(class, nestmates)("Type %s is not a nest member of resolved type %s: %s",
276 this->external_name(),
277 k->external_name(),
278 error);
279 }
280
281 if (validationException != NULL) {
282 ResourceMark rm(THREAD);
283 Exceptions::fthrow(THREAD_AND_LOCATION,
284 validationException,
285 "Type %s is not a nest member of %s: %s",
286 this->external_name(),
287 k->external_name(),
288 error
289 );
290 }
291 return NULL;
292 }
293 else {
294 if (log_is_enabled(Trace, class, nestmates)) {
295 ResourceMark rm(THREAD);
296 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
297 this->external_name());
298 }
299 // save resolved nest-host value
300 return (_nest_host = this);
301 }
302 }
303 return nest_host_k;
304 }
305
306 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
307 // or we are k's nest_host - all of which is covered by comparing the two
308 // resolved_nest_hosts
309 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
310
311 assert(this != k, "this should be handled by higher-level code");
312
313 // Per JVMS 5.4.4 we first resolve and validate the current class, then
314 // the target class k. Resolution exceptions will be passed on by upper
315 // layers. IncompatibleClassChangeErrors from membership validation failures
316 // will also be passed through.
317
318 Symbol* icce = vmSymbols::java_lang_IncompatibleClassChangeError();
319 InstanceKlass* cur_host = nest_host(icce, THREAD);
320 if (cur_host == NULL || HAS_PENDING_EXCEPTION) {
321 return false;
322 }
323
324 Klass* k_nest_host = k->nest_host(icce, THREAD);
325 if (k_nest_host == NULL || HAS_PENDING_EXCEPTION) {
326 return false;
327 }
328
329 bool access = (cur_host == k_nest_host);
330
331 if (log_is_enabled(Trace, class, nestmates)) {
332 ResourceMark rm(THREAD);
333 log_trace(class, nestmates)("Class %s does %shave nestmate accesss to %s",
334 this->external_name(),
335 access ? "" : "NOT ",
336 k->external_name());
337 }
338
339 return access;
340 }
341
342 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
343 const int size = InstanceKlass::size(parser.vtable_size(),
344 parser.itable_size(),
345 nonstatic_oop_map_size(parser.total_oop_map_count()),
346 parser.is_interface(),
347 parser.is_anonymous(),
348 should_store_fingerprint(parser.is_anonymous()));
349
350 const Symbol* const class_name = parser.class_name();
351 assert(class_name != NULL, "invariant");
352 ClassLoaderData* loader_data = parser.loader_data();
353 assert(loader_data != NULL, "invariant");
354
355 InstanceKlass* ik;
356
357 // Allocation
358 if (REF_NONE == parser.reference_type()) {
359 if (class_name == vmSymbols::java_lang_Class()) {
360 // mirror
361 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
362 }
363 else if (is_class_loader(class_name, parser)) {
364 // class loader
365 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
366 }
367 else {
368 // normal
369 ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
370 }
371 }
372 else {
373 // reference
374 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
375 }
376
377 // Check for pending exception before adding to the loader data and incrementing
378 // class count. Can get OOM here.
379 if (HAS_PENDING_EXCEPTION) {
380 return NULL;
381 }
382
383 assert(ik != NULL, "invariant");
384
385 const bool publicize = !parser.is_internal();
386
387 // Add all classes to our internal class loader list here,
388 // including classes in the bootstrap (NULL) class loader.
389 loader_data->add_class(ik, publicize);
390 Atomic::inc(&_total_instanceKlass_count);
391
392 return ik;
393 }
394
395
396 // copy method ordering from resource area to Metaspace
397 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
398 if (m != NULL) {
399 // allocate a new array and copy contents (memcpy?)
400 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
401 for (int i = 0; i < m->length(); i++) {
402 _method_ordering->at_put(i, m->at(i));
403 }
404 } else {
405 _method_ordering = Universe::the_empty_int_array();
406 }
407 }
408
409 // create a new array of vtable_indices for default methods
410 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
411 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
412 assert(default_vtable_indices() == NULL, "only create once");
413 set_default_vtable_indices(vtable_indices);
414 return vtable_indices;
415 }
416
417 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind) :
418 _static_field_size(parser.static_field_size()),
419 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
420 _itable_len(parser.itable_size()),
421 _reference_type(parser.reference_type()),
422 _nest_members(NULL),
423 _nest_host_index(0),
424 _nest_host(NULL) {
425 set_vtable_length(parser.vtable_size());
426 set_kind(kind);
427 set_access_flags(parser.access_flags());
428 set_is_anonymous(parser.is_anonymous());
429 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
430 false));
431
432 assert(NULL == _methods, "underlying memory not zeroed?");
433 assert(is_instance_klass(), "is layout incorrect?");
434 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
435 }
436
437 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
438 Array<Method*>* methods) {
439 if (methods != NULL && methods != Universe::the_empty_method_array() &&
440 !methods->is_shared()) {
441 for (int i = 0; i < methods->length(); i++) {
442 Method* method = methods->at(i);
443 if (method == NULL) continue; // maybe null if error processing
444 // Only want to delete methods that are not executing for RedefineClasses.
445 // The previous version will point to them so they're not totally dangling
446 assert (!method->on_stack(), "shouldn't be called with methods on stack");
447 MetadataFactory::free_metadata(loader_data, method);
448 }
449 MetadataFactory::free_array<Method*>(loader_data, methods);
450 }
451 }
452
453 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
454 const Klass* super_klass,
455 Array<Klass*>* local_interfaces,
456 Array<Klass*>* transitive_interfaces) {
457 // Only deallocate transitive interfaces if not empty, same as super class
458 // or same as local interfaces. See code in parseClassFile.
459 Array<Klass*>* ti = transitive_interfaces;
460 if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
461 // check that the interfaces don't come from super class
462 Array<Klass*>* sti = (super_klass == NULL) ? NULL :
463 InstanceKlass::cast(super_klass)->transitive_interfaces();
464 if (ti != sti && ti != NULL && !ti->is_shared()) {
465 MetadataFactory::free_array<Klass*>(loader_data, ti);
466 }
467 }
468
469 // local interfaces can be empty
470 if (local_interfaces != Universe::the_empty_klass_array() &&
471 local_interfaces != NULL && !local_interfaces->is_shared()) {
472 MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
473 }
474 }
475
476 // This function deallocates the metadata and C heap pointers that the
477 // InstanceKlass points to.
478 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
479
480 // Orphan the mirror first, CMS thinks it's still live.
481 if (java_mirror() != NULL) {
482 java_lang_Class::set_klass(java_mirror(), NULL);
483 }
484
485 // Also remove mirror from handles
486 loader_data->remove_handle(_java_mirror);
487
488 // Need to take this class off the class loader data list.
489 loader_data->remove_class(this);
490
491 // The array_klass for this class is created later, after error handling.
492 // For class redefinition, we keep the original class so this scratch class
493 // doesn't have an array class. Either way, assert that there is nothing
494 // to deallocate.
495 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
496
497 // Release C heap allocated data that this might point to, which includes
498 // reference counting symbol names.
499 release_C_heap_structures();
500
501 deallocate_methods(loader_data, methods());
502 set_methods(NULL);
503
504 if (method_ordering() != NULL &&
505 method_ordering() != Universe::the_empty_int_array() &&
506 !method_ordering()->is_shared()) {
507 MetadataFactory::free_array<int>(loader_data, method_ordering());
508 }
509 set_method_ordering(NULL);
510
511 // default methods can be empty
512 if (default_methods() != NULL &&
513 default_methods() != Universe::the_empty_method_array() &&
514 !default_methods()->is_shared()) {
515 MetadataFactory::free_array<Method*>(loader_data, default_methods());
516 }
517 // Do NOT deallocate the default methods, they are owned by superinterfaces.
518 set_default_methods(NULL);
519
520 // default methods vtable indices can be empty
521 if (default_vtable_indices() != NULL &&
522 !default_vtable_indices()->is_shared()) {
523 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
524 }
525 set_default_vtable_indices(NULL);
526
527
528 // This array is in Klass, but remove it with the InstanceKlass since
529 // this place would be the only caller and it can share memory with transitive
530 // interfaces.
531 if (secondary_supers() != NULL &&
532 secondary_supers() != Universe::the_empty_klass_array() &&
533 secondary_supers() != transitive_interfaces() &&
534 !secondary_supers()->is_shared()) {
535 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
536 }
537 set_secondary_supers(NULL);
538
539 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
540 set_transitive_interfaces(NULL);
541 set_local_interfaces(NULL);
542
543 if (fields() != NULL && !fields()->is_shared()) {
544 MetadataFactory::free_array<jushort>(loader_data, fields());
545 }
546 set_fields(NULL, 0);
547
548 // If a method from a redefined class is using this constant pool, don't
549 // delete it, yet. The new class's previous version will point to this.
550 if (constants() != NULL) {
551 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
552 if (!constants()->is_shared()) {
553 MetadataFactory::free_metadata(loader_data, constants());
554 }
555 // Delete any cached resolution errors for the constant pool
556 SystemDictionary::delete_resolution_error(constants());
557
558 set_constants(NULL);
559 }
560
561 if (inner_classes() != NULL &&
562 inner_classes() != Universe::the_empty_short_array() &&
563 !inner_classes()->is_shared()) {
564 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
565 }
566 set_inner_classes(NULL);
567
568 if (nest_members() != NULL &&
569 nest_members() != Universe::the_empty_short_array() &&
570 !nest_members()->is_shared()) {
571 MetadataFactory::free_array<jushort>(loader_data, nest_members());
572 }
573 set_nest_members(NULL);
574
575 // We should deallocate the Annotations instance if it's not in shared spaces.
576 if (annotations() != NULL && !annotations()->is_shared()) {
577 MetadataFactory::free_metadata(loader_data, annotations());
578 }
579 set_annotations(NULL);
580 }
581
582 bool InstanceKlass::should_be_initialized() const {
583 return !is_initialized();
584 }
585
586 klassItable InstanceKlass::itable() const {
587 return klassItable(const_cast<InstanceKlass*>(this));
588 }
589
590 void InstanceKlass::eager_initialize(Thread *thread) {
591 if (!EagerInitialization) return;
592
593 if (this->is_not_initialized()) {
594 // abort if the the class has a class initializer
595 if (this->class_initializer() != NULL) return;
596
597 // abort if it is java.lang.Object (initialization is handled in genesis)
598 Klass* super_klass = super();
599 if (super_klass == NULL) return;
600
601 // abort if the super class should be initialized
602 if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
603
604 // call body to expose the this pointer
605 eager_initialize_impl();
606 }
607 }
608
609 // JVMTI spec thinks there are signers and protection domain in the
610 // instanceKlass. These accessors pretend these fields are there.
611 // The hprof specification also thinks these fields are in InstanceKlass.
612 oop InstanceKlass::protection_domain() const {
613 // return the protection_domain from the mirror
614 return java_lang_Class::protection_domain(java_mirror());
615 }
616
617 // To remove these from requires an incompatible change and CCC request.
618 objArrayOop InstanceKlass::signers() const {
619 // return the signers from the mirror
620 return java_lang_Class::signers(java_mirror());
621 }
622
623 oop InstanceKlass::init_lock() const {
624 // return the init lock from the mirror
625 oop lock = java_lang_Class::init_lock(java_mirror());
626 // Prevent reordering with any access of initialization state
627 OrderAccess::loadload();
628 assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
629 "only fully initialized state can have a null lock");
630 return lock;
631 }
632
633 // Set the initialization lock to null so the object can be GC'ed. Any racing
634 // threads to get this lock will see a null lock and will not lock.
635 // That's okay because they all check for initialized state after getting
636 // the lock and return.
637 void InstanceKlass::fence_and_clear_init_lock() {
638 // make sure previous stores are all done, notably the init_state.
639 OrderAccess::storestore();
640 java_lang_Class::set_init_lock(java_mirror(), NULL);
641 assert(!is_not_initialized(), "class must be initialized now");
642 }
643
644 void InstanceKlass::eager_initialize_impl() {
645 EXCEPTION_MARK;
646 HandleMark hm(THREAD);
647 Handle h_init_lock(THREAD, init_lock());
648 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
649
650 // abort if someone beat us to the initialization
651 if (!is_not_initialized()) return; // note: not equivalent to is_initialized()
652
653 ClassState old_state = init_state();
654 link_class_impl(true, THREAD);
655 if (HAS_PENDING_EXCEPTION) {
656 CLEAR_PENDING_EXCEPTION;
657 // Abort if linking the class throws an exception.
658
659 // Use a test to avoid redundantly resetting the state if there's
660 // no change. Set_init_state() asserts that state changes make
661 // progress, whereas here we might just be spinning in place.
662 if (old_state != _init_state)
663 set_init_state(old_state);
664 } else {
665 // linking successfull, mark class as initialized
666 set_init_state(fully_initialized);
667 fence_and_clear_init_lock();
668 // trace
669 if (log_is_enabled(Info, class, init)) {
670 ResourceMark rm(THREAD);
671 log_info(class, init)("[Initialized %s without side effects]", external_name());
672 }
673 }
674 }
675
676
677 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
678 // process. The step comments refers to the procedure described in that section.
679 // Note: implementation moved to static method to expose the this pointer.
680 void InstanceKlass::initialize(TRAPS) {
681 if (this->should_be_initialized()) {
682 initialize_impl(CHECK);
683 // Note: at this point the class may be initialized
684 // OR it may be in the state of being initialized
685 // in case of recursive initialization!
686 } else {
687 assert(is_initialized(), "sanity check");
688 }
689 }
690
691
692 bool InstanceKlass::verify_code(bool throw_verifyerror, TRAPS) {
693 // 1) Verify the bytecodes
694 Verifier::Mode mode =
695 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
696 return Verifier::verify(this, mode, should_verify_class(), THREAD);
697 }
698
699
700 // Used exclusively by the shared spaces dump mechanism to prevent
701 // classes mapped into the shared regions in new VMs from appearing linked.
702
703 void InstanceKlass::unlink_class() {
704 assert(is_linked(), "must be linked");
705 _init_state = loaded;
706 }
707
708 void InstanceKlass::link_class(TRAPS) {
709 assert(is_loaded(), "must be loaded");
710 if (!is_linked()) {
711 link_class_impl(true, CHECK);
712 }
713 }
714
715 // Called to verify that a class can link during initialization, without
716 // throwing a VerifyError.
717 bool InstanceKlass::link_class_or_fail(TRAPS) {
718 assert(is_loaded(), "must be loaded");
719 if (!is_linked()) {
720 link_class_impl(false, CHECK_false);
721 }
722 return is_linked();
723 }
724
725 bool InstanceKlass::link_class_impl(bool throw_verifyerror, TRAPS) {
726 if (DumpSharedSpaces && is_in_error_state()) {
727 // This is for CDS dumping phase only -- we use the in_error_state to indicate that
728 // the class has failed verification. Throwing the NoClassDefFoundError here is just
729 // a convenient way to stop repeat attempts to verify the same (bad) class.
730 //
731 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
732 // if we are executing Java code. This is not a problem for CDS dumping phase since
733 // it doesn't execute any Java code.
734 ResourceMark rm(THREAD);
735 Exceptions::fthrow(THREAD_AND_LOCATION,
736 vmSymbols::java_lang_NoClassDefFoundError(),
737 "Class %s, or one of its supertypes, failed class initialization",
738 external_name());
739 return false;
740 }
741 // return if already verified
742 if (is_linked()) {
743 return true;
744 }
745
746 // Timing
747 // timer handles recursion
748 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
749 JavaThread* jt = (JavaThread*)THREAD;
750
751 // link super class before linking this class
752 Klass* super_klass = super();
753 if (super_klass != NULL) {
754 if (super_klass->is_interface()) { // check if super class is an interface
755 ResourceMark rm(THREAD);
756 Exceptions::fthrow(
757 THREAD_AND_LOCATION,
758 vmSymbols::java_lang_IncompatibleClassChangeError(),
759 "class %s has interface %s as super class",
760 external_name(),
761 super_klass->external_name()
762 );
763 return false;
764 }
765
766 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
767 ik_super->link_class_impl(throw_verifyerror, CHECK_false);
768 }
769
770 // link all interfaces implemented by this class before linking this class
771 Array<Klass*>* interfaces = local_interfaces();
772 int num_interfaces = interfaces->length();
773 for (int index = 0; index < num_interfaces; index++) {
774 InstanceKlass* interk = InstanceKlass::cast(interfaces->at(index));
775 interk->link_class_impl(throw_verifyerror, CHECK_false);
776 }
777
778 // in case the class is linked in the process of linking its superclasses
779 if (is_linked()) {
780 return true;
781 }
782
783 // trace only the link time for this klass that includes
784 // the verification time
785 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
786 ClassLoader::perf_class_link_selftime(),
787 ClassLoader::perf_classes_linked(),
788 jt->get_thread_stat()->perf_recursion_counts_addr(),
789 jt->get_thread_stat()->perf_timers_addr(),
790 PerfClassTraceTime::CLASS_LINK);
791
792 // verification & rewriting
793 {
794 HandleMark hm(THREAD);
795 Handle h_init_lock(THREAD, init_lock());
796 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
797 // rewritten will have been set if loader constraint error found
798 // on an earlier link attempt
799 // don't verify or rewrite if already rewritten
800 //
801
802 if (!is_linked()) {
803 if (!is_rewritten()) {
804 {
805 bool verify_ok = verify_code(throw_verifyerror, THREAD);
806 if (!verify_ok) {
807 return false;
808 }
809 }
810
811 // Just in case a side-effect of verify linked this class already
812 // (which can sometimes happen since the verifier loads classes
813 // using custom class loaders, which are free to initialize things)
814 if (is_linked()) {
815 return true;
816 }
817
818 // also sets rewritten
819 rewrite_class(CHECK_false);
820 } else if (is_shared()) {
821 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
822 }
823
824 // relocate jsrs and link methods after they are all rewritten
825 link_methods(CHECK_false);
826
827 // Initialize the vtable and interface table after
828 // methods have been rewritten since rewrite may
829 // fabricate new Method*s.
830 // also does loader constraint checking
831 //
832 // initialize_vtable and initialize_itable need to be rerun for
833 // a shared class if the class is not loaded by the NULL classloader.
834 ClassLoaderData * loader_data = class_loader_data();
835 if (!(is_shared() &&
836 loader_data->is_the_null_class_loader_data())) {
837 ResourceMark rm(THREAD);
838 vtable().initialize_vtable(true, CHECK_false);
839 itable().initialize_itable(true, CHECK_false);
840 }
841 #ifdef ASSERT
842 else {
843 vtable().verify(tty, true);
844 // In case itable verification is ever added.
845 // itable().verify(tty, true);
846 }
847 #endif
848 set_init_state(linked);
849 if (JvmtiExport::should_post_class_prepare()) {
850 Thread *thread = THREAD;
851 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
852 JvmtiExport::post_class_prepare((JavaThread *) thread, this);
853 }
854 }
855 }
856 return true;
857 }
858
859 // Rewrite the byte codes of all of the methods of a class.
860 // The rewriter must be called exactly once. Rewriting must happen after
861 // verification but before the first method of the class is executed.
862 void InstanceKlass::rewrite_class(TRAPS) {
863 assert(is_loaded(), "must be loaded");
864 if (is_rewritten()) {
865 assert(is_shared(), "rewriting an unshared class?");
866 return;
867 }
868 Rewriter::rewrite(this, CHECK);
869 set_rewritten();
870 }
871
872 // Now relocate and link method entry points after class is rewritten.
873 // This is outside is_rewritten flag. In case of an exception, it can be
874 // executed more than once.
875 void InstanceKlass::link_methods(TRAPS) {
876 int len = methods()->length();
877 for (int i = len-1; i >= 0; i--) {
878 methodHandle m(THREAD, methods()->at(i));
879
880 // Set up method entry points for compiler and interpreter .
881 m->link_method(m, CHECK);
882 }
883 }
884
885 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
886 void InstanceKlass::initialize_super_interfaces(TRAPS) {
887 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
888 for (int i = 0; i < local_interfaces()->length(); ++i) {
889 Klass* iface = local_interfaces()->at(i);
890 InstanceKlass* ik = InstanceKlass::cast(iface);
891
892 // Initialization is depth first search ie. we start with top of the inheritance tree
893 // has_nonstatic_concrete_methods drives searching superinterfaces since it
894 // means has_nonstatic_concrete_methods in its superinterface hierarchy
895 if (ik->has_nonstatic_concrete_methods()) {
896 ik->initialize_super_interfaces(CHECK);
897 }
898
899 // Only initialize() interfaces that "declare" concrete methods.
900 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
901 ik->initialize(CHECK);
902 }
903 }
904 }
905
906 void InstanceKlass::initialize_impl(TRAPS) {
907 HandleMark hm(THREAD);
908
909 // Make sure klass is linked (verified) before initialization
910 // A class could already be verified, since it has been reflected upon.
911 link_class(CHECK);
912
913 DTRACE_CLASSINIT_PROBE(required, -1);
914
915 bool wait = false;
916
917 // refer to the JVM book page 47 for description of steps
918 // Step 1
919 {
920 Handle h_init_lock(THREAD, init_lock());
921 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
922
923 Thread *self = THREAD; // it's passed the current thread
924
925 // Step 2
926 // If we were to use wait() instead of waitInterruptibly() then
927 // we might end up throwing IE from link/symbol resolution sites
928 // that aren't expected to throw. This would wreak havoc. See 6320309.
929 while(is_being_initialized() && !is_reentrant_initialization(self)) {
930 wait = true;
931 ol.waitUninterruptibly(CHECK);
932 }
933
934 // Step 3
935 if (is_being_initialized() && is_reentrant_initialization(self)) {
936 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
937 return;
938 }
939
940 // Step 4
941 if (is_initialized()) {
942 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
943 return;
944 }
945
946 // Step 5
947 if (is_in_error_state()) {
948 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
949 ResourceMark rm(THREAD);
950 const char* desc = "Could not initialize class ";
951 const char* className = external_name();
952 size_t msglen = strlen(desc) + strlen(className) + 1;
953 char* message = NEW_RESOURCE_ARRAY(char, msglen);
954 if (NULL == message) {
955 // Out of memory: can't create detailed error message
956 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
957 } else {
958 jio_snprintf(message, msglen, "%s%s", desc, className);
959 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
960 }
961 }
962
963 // Step 6
964 set_init_state(being_initialized);
965 set_init_thread(self);
966 }
967
968 // Step 7
969 // Next, if C is a class rather than an interface, initialize it's super class and super
970 // interfaces.
971 if (!is_interface()) {
972 Klass* super_klass = super();
973 if (super_klass != NULL && super_klass->should_be_initialized()) {
974 super_klass->initialize(THREAD);
975 }
976 // If C implements any interface that declares a non-static, concrete method,
977 // the initialization of C triggers initialization of its super interfaces.
978 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
979 // having a superinterface that declares, non-static, concrete methods
980 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
981 initialize_super_interfaces(THREAD);
982 }
983
984 // If any exceptions, complete abruptly, throwing the same exception as above.
985 if (HAS_PENDING_EXCEPTION) {
986 Handle e(THREAD, PENDING_EXCEPTION);
987 CLEAR_PENDING_EXCEPTION;
988 {
989 EXCEPTION_MARK;
990 // Locks object, set state, and notify all waiting threads
991 set_initialization_state_and_notify(initialization_error, THREAD);
992 CLEAR_PENDING_EXCEPTION;
993 }
994 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
995 THROW_OOP(e());
996 }
997 }
998
999
1000 // Look for aot compiled methods for this klass, including class initializer.
1001 AOTLoader::load_for_klass(this, THREAD);
1002
1003 // Step 8
1004 {
1005 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
1006 JavaThread* jt = (JavaThread*)THREAD;
1007 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1008 // Timer includes any side effects of class initialization (resolution,
1009 // etc), but not recursive entry into call_class_initializer().
1010 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1011 ClassLoader::perf_class_init_selftime(),
1012 ClassLoader::perf_classes_inited(),
1013 jt->get_thread_stat()->perf_recursion_counts_addr(),
1014 jt->get_thread_stat()->perf_timers_addr(),
1015 PerfClassTraceTime::CLASS_CLINIT);
1016 call_class_initializer(THREAD);
1017 }
1018
1019 // Step 9
1020 if (!HAS_PENDING_EXCEPTION) {
1021 set_initialization_state_and_notify(fully_initialized, CHECK);
1022 {
1023 debug_only(vtable().verify(tty, true);)
1024 }
1025 }
1026 else {
1027 // Step 10 and 11
1028 Handle e(THREAD, PENDING_EXCEPTION);
1029 CLEAR_PENDING_EXCEPTION;
1030 // JVMTI has already reported the pending exception
1031 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1032 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
1033 {
1034 EXCEPTION_MARK;
1035 set_initialization_state_and_notify(initialization_error, THREAD);
1036 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1037 // JVMTI has already reported the pending exception
1038 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1039 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
1040 }
1041 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1042 if (e->is_a(SystemDictionary::Error_klass())) {
1043 THROW_OOP(e());
1044 } else {
1045 JavaCallArguments args(e);
1046 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1047 vmSymbols::throwable_void_signature(),
1048 &args);
1049 }
1050 }
1051 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1052 }
1053
1054
1055 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1056 Handle h_init_lock(THREAD, init_lock());
1057 if (h_init_lock() != NULL) {
1058 ObjectLocker ol(h_init_lock, THREAD);
1059 set_init_state(state);
1060 fence_and_clear_init_lock();
1061 ol.notify_all(CHECK);
1062 } else {
1063 assert(h_init_lock() != NULL, "The initialization state should never be set twice");
1064 set_init_state(state);
1065 }
1066 }
1067
1068 // The embedded _implementor field can only record one implementor.
1069 // When there are more than one implementors, the _implementor field
1070 // is set to the interface Klass* itself. Following are the possible
1071 // values for the _implementor field:
1072 // NULL - no implementor
1073 // implementor Klass* - one implementor
1074 // self - more than one implementor
1075 //
1076 // The _implementor field only exists for interfaces.
1077 void InstanceKlass::add_implementor(Klass* k) {
1078 assert(Compile_lock->owned_by_self(), "");
1079 assert(is_interface(), "not interface");
1080 // Filter out my subinterfaces.
1081 // (Note: Interfaces are never on the subklass list.)
1082 if (InstanceKlass::cast(k)->is_interface()) return;
1083
1084 // Filter out subclasses whose supers already implement me.
1085 // (Note: CHA must walk subclasses of direct implementors
1086 // in order to locate indirect implementors.)
1087 Klass* sk = k->super();
1088 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
1089 // We only need to check one immediate superclass, since the
1090 // implements_interface query looks at transitive_interfaces.
1091 // Any supers of the super have the same (or fewer) transitive_interfaces.
1092 return;
1093
1094 Klass* ik = implementor();
1095 if (ik == NULL) {
1096 set_implementor(k);
1097 } else if (ik != this) {
1098 // There is already an implementor. Use itself as an indicator of
1099 // more than one implementors.
1100 set_implementor(this);
1101 }
1102
1103 // The implementor also implements the transitive_interfaces
1104 for (int index = 0; index < local_interfaces()->length(); index++) {
1105 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
1106 }
1107 }
1108
1109 void InstanceKlass::init_implementor() {
1110 if (is_interface()) {
1111 set_implementor(NULL);
1112 }
1113 }
1114
1115
1116 void InstanceKlass::process_interfaces(Thread *thread) {
1117 // link this class into the implementors list of every interface it implements
1118 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1119 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1120 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
1121 assert(interf->is_interface(), "expected interface");
1122 interf->add_implementor(this);
1123 }
1124 }
1125
1126 bool InstanceKlass::can_be_primary_super_slow() const {
1127 if (is_interface())
1128 return false;
1129 else
1130 return Klass::can_be_primary_super_slow();
1131 }
1132
1133 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
1134 // The secondaries are the implemented interfaces.
1135 Array<Klass*>* interfaces = transitive_interfaces();
1136 int num_secondaries = num_extra_slots + interfaces->length();
1137 if (num_secondaries == 0) {
1138 // Must share this for correct bootstrapping!
1139 set_secondary_supers(Universe::the_empty_klass_array());
1140 return NULL;
1141 } else if (num_extra_slots == 0) {
1142 // The secondary super list is exactly the same as the transitive interfaces.
1143 // Redefine classes has to be careful not to delete this!
1144 set_secondary_supers(interfaces);
1145 return NULL;
1146 } else {
1147 // Copy transitive interfaces to a temporary growable array to be constructed
1148 // into the secondary super list with extra slots.
1149 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1150 for (int i = 0; i < interfaces->length(); i++) {
1151 secondaries->push(interfaces->at(i));
1152 }
1153 return secondaries;
1154 }
1155 }
1156
1157 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
1158 if (k->is_interface()) {
1159 return implements_interface(k);
1160 } else {
1161 return Klass::compute_is_subtype_of(k);
1162 }
1163 }
1164
1165 bool InstanceKlass::implements_interface(Klass* k) const {
1166 if (this == k) return true;
1167 assert(k->is_interface(), "should be an interface class");
1168 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1169 if (transitive_interfaces()->at(i) == k) {
1170 return true;
1171 }
1172 }
1173 return false;
1174 }
1175
1176 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1177 // Verify direct super interface
1178 if (this == k) return true;
1179 assert(k->is_interface(), "should be an interface class");
1180 for (int i = 0; i < local_interfaces()->length(); i++) {
1181 if (local_interfaces()->at(i) == k) {
1182 return true;
1183 }
1184 }
1185 return false;
1186 }
1187
1188 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1189 if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
1190 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
1191 report_java_out_of_memory("Requested array size exceeds VM limit");
1192 JvmtiExport::post_array_size_exhausted();
1193 THROW_OOP_0(Universe::out_of_memory_error_array_size());
1194 }
1195 int size = objArrayOopDesc::object_size(length);
1196 Klass* ak = array_klass(n, CHECK_NULL);
1197 objArrayOop o =
1198 (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_NULL);
1199 return o;
1200 }
1201
1202 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1203 if (TraceFinalizerRegistration) {
1204 tty->print("Registered ");
1205 i->print_value_on(tty);
1206 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1207 }
1208 instanceHandle h_i(THREAD, i);
1209 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1210 JavaValue result(T_VOID);
1211 JavaCallArguments args(h_i);
1212 methodHandle mh (THREAD, Universe::finalizer_register_method());
1213 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1214 return h_i();
1215 }
1216
1217 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1218 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1219 int size = size_helper(); // Query before forming handle.
1220
1221 instanceOop i;
1222
1223 i = (instanceOop)CollectedHeap::obj_allocate(this, size, CHECK_NULL);
1224 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1225 i = register_finalizer(i, CHECK_NULL);
1226 }
1227 return i;
1228 }
1229
1230 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1231 if (is_interface() || is_abstract()) {
1232 ResourceMark rm(THREAD);
1233 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1234 : vmSymbols::java_lang_InstantiationException(), external_name());
1235 }
1236 if (this == SystemDictionary::Class_klass()) {
1237 ResourceMark rm(THREAD);
1238 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1239 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1240 }
1241 }
1242
1243 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1244 // Need load-acquire for lock-free read
1245 if (array_klasses_acquire() == NULL) {
1246 if (or_null) return NULL;
1247
1248 ResourceMark rm;
1249 JavaThread *jt = (JavaThread *)THREAD;
1250 {
1251 // Atomic creation of array_klasses
1252 MutexLocker mc(Compile_lock, THREAD); // for vtables
1253 MutexLocker ma(MultiArray_lock, THREAD);
1254
1255 // Check if update has already taken place
1256 if (array_klasses() == NULL) {
1257 Klass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1258 // use 'release' to pair with lock-free load
1259 release_set_array_klasses(k);
1260 }
1261 }
1262 }
1263 // _this will always be set at this point
1264 ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1265 if (or_null) {
1266 return oak->array_klass_or_null(n);
1267 }
1268 return oak->array_klass(n, THREAD);
1269 }
1270
1271 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1272 return array_klass_impl(or_null, 1, THREAD);
1273 }
1274
1275 static int call_class_initializer_counter = 0; // for debugging
1276
1277 Method* InstanceKlass::class_initializer() const {
1278 Method* clinit = find_method(
1279 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1280 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1281 return clinit;
1282 }
1283 return NULL;
1284 }
1285
1286 void InstanceKlass::call_class_initializer(TRAPS) {
1287 if (ReplayCompiles &&
1288 (ReplaySuppressInitializers == 1 ||
1289 (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1290 // Hide the existence of the initializer for the purpose of replaying the compile
1291 return;
1292 }
1293
1294 methodHandle h_method(THREAD, class_initializer());
1295 assert(!is_initialized(), "we cannot initialize twice");
1296 LogTarget(Info, class, init) lt;
1297 if (lt.is_enabled()) {
1298 ResourceMark rm;
1299 LogStream ls(lt);
1300 ls.print("%d Initializing ", call_class_initializer_counter++);
1301 name()->print_value_on(&ls);
1302 ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1303 }
1304 if (h_method() != NULL) {
1305 JavaCallArguments args; // No arguments
1306 JavaValue result(T_VOID);
1307 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1308 }
1309 }
1310
1311
1312 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1313 InterpreterOopMap* entry_for) {
1314 // Lazily create the _oop_map_cache at first request
1315 // Lock-free access requires load_acquire.
1316 OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache);
1317 if (oop_map_cache == NULL) {
1318 MutexLocker x(OopMapCacheAlloc_lock);
1319 // Check if _oop_map_cache was allocated while we were waiting for this lock
1320 if ((oop_map_cache = _oop_map_cache) == NULL) {
1321 oop_map_cache = new OopMapCache();
1322 // Ensure _oop_map_cache is stable, since it is examined without a lock
1323 OrderAccess::release_store(&_oop_map_cache, oop_map_cache);
1324 }
1325 }
1326 // _oop_map_cache is constant after init; lookup below does its own locking.
1327 oop_map_cache->lookup(method, bci, entry_for);
1328 }
1329
1330
1331 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1332 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1333 Symbol* f_name = fs.name();
1334 Symbol* f_sig = fs.signature();
1335 if (f_name == name && f_sig == sig) {
1336 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1337 return true;
1338 }
1339 }
1340 return false;
1341 }
1342
1343
1344 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1345 const int n = local_interfaces()->length();
1346 for (int i = 0; i < n; i++) {
1347 Klass* intf1 = local_interfaces()->at(i);
1348 assert(intf1->is_interface(), "just checking type");
1349 // search for field in current interface
1350 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1351 assert(fd->is_static(), "interface field must be static");
1352 return intf1;
1353 }
1354 // search for field in direct superinterfaces
1355 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1356 if (intf2 != NULL) return intf2;
1357 }
1358 // otherwise field lookup fails
1359 return NULL;
1360 }
1361
1362
1363 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1364 // search order according to newest JVM spec (5.4.3.2, p.167).
1365 // 1) search for field in current klass
1366 if (find_local_field(name, sig, fd)) {
1367 return const_cast<InstanceKlass*>(this);
1368 }
1369 // 2) search for field recursively in direct superinterfaces
1370 { Klass* intf = find_interface_field(name, sig, fd);
1371 if (intf != NULL) return intf;
1372 }
1373 // 3) apply field lookup recursively if superclass exists
1374 { Klass* supr = super();
1375 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1376 }
1377 // 4) otherwise field lookup fails
1378 return NULL;
1379 }
1380
1381
1382 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1383 // search order according to newest JVM spec (5.4.3.2, p.167).
1384 // 1) search for field in current klass
1385 if (find_local_field(name, sig, fd)) {
1386 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1387 }
1388 // 2) search for field recursively in direct superinterfaces
1389 if (is_static) {
1390 Klass* intf = find_interface_field(name, sig, fd);
1391 if (intf != NULL) return intf;
1392 }
1393 // 3) apply field lookup recursively if superclass exists
1394 { Klass* supr = super();
1395 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1396 }
1397 // 4) otherwise field lookup fails
1398 return NULL;
1399 }
1400
1401
1402 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1403 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1404 if (fs.offset() == offset) {
1405 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1406 if (fd->is_static() == is_static) return true;
1407 }
1408 }
1409 return false;
1410 }
1411
1412
1413 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1414 Klass* klass = const_cast<InstanceKlass*>(this);
1415 while (klass != NULL) {
1416 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1417 return true;
1418 }
1419 klass = klass->super();
1420 }
1421 return false;
1422 }
1423
1424
1425 void InstanceKlass::methods_do(void f(Method* method)) {
1426 // Methods aren't stable until they are loaded. This can be read outside
1427 // a lock through the ClassLoaderData for profiling
1428 if (!is_loaded()) {
1429 return;
1430 }
1431
1432 int len = methods()->length();
1433 for (int index = 0; index < len; index++) {
1434 Method* m = methods()->at(index);
1435 assert(m->is_method(), "must be method");
1436 f(m);
1437 }
1438 }
1439
1440
1441 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1442 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1443 if (fs.access_flags().is_static()) {
1444 fieldDescriptor& fd = fs.field_descriptor();
1445 cl->do_field(&fd);
1446 }
1447 }
1448 }
1449
1450
1451 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1452 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1453 if (fs.access_flags().is_static()) {
1454 fieldDescriptor& fd = fs.field_descriptor();
1455 f(&fd, mirror, CHECK);
1456 }
1457 }
1458 }
1459
1460
1461 static int compare_fields_by_offset(int* a, int* b) {
1462 return a[0] - b[0];
1463 }
1464
1465 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1466 InstanceKlass* super = superklass();
1467 if (super != NULL) {
1468 super->do_nonstatic_fields(cl);
1469 }
1470 fieldDescriptor fd;
1471 int length = java_fields_count();
1472 // In DebugInfo nonstatic fields are sorted by offset.
1473 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1474 int j = 0;
1475 for (int i = 0; i < length; i += 1) {
1476 fd.reinitialize(this, i);
1477 if (!fd.is_static()) {
1478 fields_sorted[j + 0] = fd.offset();
1479 fields_sorted[j + 1] = i;
1480 j += 2;
1481 }
1482 }
1483 if (j > 0) {
1484 length = j;
1485 // _sort_Fn is defined in growableArray.hpp.
1486 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1487 for (int i = 0; i < length; i += 2) {
1488 fd.reinitialize(this, fields_sorted[i + 1]);
1489 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1490 cl->do_field(&fd);
1491 }
1492 }
1493 FREE_C_HEAP_ARRAY(int, fields_sorted);
1494 }
1495
1496
1497 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1498 if (array_klasses() != NULL)
1499 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1500 }
1501
1502 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1503 if (array_klasses() != NULL)
1504 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1505 }
1506
1507 #ifdef ASSERT
1508 static int linear_search(const Array<Method*>* methods,
1509 const Symbol* name,
1510 const Symbol* signature) {
1511 const int len = methods->length();
1512 for (int index = 0; index < len; index++) {
1513 const Method* const m = methods->at(index);
1514 assert(m->is_method(), "must be method");
1515 if (m->signature() == signature && m->name() == name) {
1516 return index;
1517 }
1518 }
1519 return -1;
1520 }
1521 #endif
1522
1523 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1524 int len = methods->length();
1525 // methods are sorted, so do binary search
1526 int l = 0;
1527 int h = len - 1;
1528 while (l <= h) {
1529 int mid = (l + h) >> 1;
1530 Method* m = methods->at(mid);
1531 assert(m->is_method(), "must be method");
1532 int res = m->name()->fast_compare(name);
1533 if (res == 0) {
1534 return mid;
1535 } else if (res < 0) {
1536 l = mid + 1;
1537 } else {
1538 h = mid - 1;
1539 }
1540 }
1541 return -1;
1542 }
1543
1544 // find_method looks up the name/signature in the local methods array
1545 Method* InstanceKlass::find_method(const Symbol* name,
1546 const Symbol* signature) const {
1547 return find_method_impl(name, signature, find_overpass, find_static, find_private);
1548 }
1549
1550 Method* InstanceKlass::find_method_impl(const Symbol* name,
1551 const Symbol* signature,
1552 OverpassLookupMode overpass_mode,
1553 StaticLookupMode static_mode,
1554 PrivateLookupMode private_mode) const {
1555 return InstanceKlass::find_method_impl(methods(),
1556 name,
1557 signature,
1558 overpass_mode,
1559 static_mode,
1560 private_mode);
1561 }
1562
1563 // find_instance_method looks up the name/signature in the local methods array
1564 // and skips over static methods
1565 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1566 const Symbol* name,
1567 const Symbol* signature) {
1568 Method* const meth = InstanceKlass::find_method_impl(methods,
1569 name,
1570 signature,
1571 find_overpass,
1572 skip_static,
1573 find_private);
1574 assert(((meth == NULL) || !meth->is_static()),
1575 "find_instance_method should have skipped statics");
1576 return meth;
1577 }
1578
1579 // find_instance_method looks up the name/signature in the local methods array
1580 // and skips over static methods
1581 Method* InstanceKlass::find_instance_method(const Symbol* name, const Symbol* signature) const {
1582 return InstanceKlass::find_instance_method(methods(), name, signature);
1583 }
1584
1585 // Find looks up the name/signature in the local methods array
1586 // and filters on the overpass, static and private flags
1587 // This returns the first one found
1588 // note that the local methods array can have up to one overpass, one static
1589 // and one instance (private or not) with the same name/signature
1590 Method* InstanceKlass::find_local_method(const Symbol* name,
1591 const Symbol* signature,
1592 OverpassLookupMode overpass_mode,
1593 StaticLookupMode static_mode,
1594 PrivateLookupMode private_mode) const {
1595 return InstanceKlass::find_method_impl(methods(),
1596 name,
1597 signature,
1598 overpass_mode,
1599 static_mode,
1600 private_mode);
1601 }
1602
1603 // Find looks up the name/signature in the local methods array
1604 // and filters on the overpass, static and private flags
1605 // This returns the first one found
1606 // note that the local methods array can have up to one overpass, one static
1607 // and one instance (private or not) with the same name/signature
1608 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1609 const Symbol* name,
1610 const Symbol* signature,
1611 OverpassLookupMode overpass_mode,
1612 StaticLookupMode static_mode,
1613 PrivateLookupMode private_mode) {
1614 return InstanceKlass::find_method_impl(methods,
1615 name,
1616 signature,
1617 overpass_mode,
1618 static_mode,
1619 private_mode);
1620 }
1621
1622 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1623 const Symbol* name,
1624 const Symbol* signature) {
1625 return InstanceKlass::find_method_impl(methods,
1626 name,
1627 signature,
1628 find_overpass,
1629 find_static,
1630 find_private);
1631 }
1632
1633 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1634 const Symbol* name,
1635 const Symbol* signature,
1636 OverpassLookupMode overpass_mode,
1637 StaticLookupMode static_mode,
1638 PrivateLookupMode private_mode) {
1639 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1640 return hit >= 0 ? methods->at(hit): NULL;
1641 }
1642
1643 // true if method matches signature and conforms to skipping_X conditions.
1644 static bool method_matches(const Method* m,
1645 const Symbol* signature,
1646 bool skipping_overpass,
1647 bool skipping_static,
1648 bool skipping_private) {
1649 return ((m->signature() == signature) &&
1650 (!skipping_overpass || !m->is_overpass()) &&
1651 (!skipping_static || !m->is_static()) &&
1652 (!skipping_private || !m->is_private()));
1653 }
1654
1655 // Used directly for default_methods to find the index into the
1656 // default_vtable_indices, and indirectly by find_method
1657 // find_method_index looks in the local methods array to return the index
1658 // of the matching name/signature. If, overpass methods are being ignored,
1659 // the search continues to find a potential non-overpass match. This capability
1660 // is important during method resolution to prefer a static method, for example,
1661 // over an overpass method.
1662 // There is the possibility in any _method's array to have the same name/signature
1663 // for a static method, an overpass method and a local instance method
1664 // To correctly catch a given method, the search criteria may need
1665 // to explicitly skip the other two. For local instance methods, it
1666 // is often necessary to skip private methods
1667 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1668 const Symbol* name,
1669 const Symbol* signature,
1670 OverpassLookupMode overpass_mode,
1671 StaticLookupMode static_mode,
1672 PrivateLookupMode private_mode) {
1673 const bool skipping_overpass = (overpass_mode == skip_overpass);
1674 const bool skipping_static = (static_mode == skip_static);
1675 const bool skipping_private = (private_mode == skip_private);
1676 const int hit = binary_search(methods, name);
1677 if (hit != -1) {
1678 const Method* const m = methods->at(hit);
1679
1680 // Do linear search to find matching signature. First, quick check
1681 // for common case, ignoring overpasses if requested.
1682 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1683 return hit;
1684 }
1685
1686 // search downwards through overloaded methods
1687 int i;
1688 for (i = hit - 1; i >= 0; --i) {
1689 const Method* const m = methods->at(i);
1690 assert(m->is_method(), "must be method");
1691 if (m->name() != name) {
1692 break;
1693 }
1694 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1695 return i;
1696 }
1697 }
1698 // search upwards
1699 for (i = hit + 1; i < methods->length(); ++i) {
1700 const Method* const m = methods->at(i);
1701 assert(m->is_method(), "must be method");
1702 if (m->name() != name) {
1703 break;
1704 }
1705 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1706 return i;
1707 }
1708 }
1709 // not found
1710 #ifdef ASSERT
1711 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1712 linear_search(methods, name, signature);
1713 assert(-1 == index, "binary search should have found entry %d", index);
1714 #endif
1715 }
1716 return -1;
1717 }
1718
1719 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1720 return find_method_by_name(methods(), name, end);
1721 }
1722
1723 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1724 const Symbol* name,
1725 int* end_ptr) {
1726 assert(end_ptr != NULL, "just checking");
1727 int start = binary_search(methods, name);
1728 int end = start + 1;
1729 if (start != -1) {
1730 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1731 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1732 *end_ptr = end;
1733 return start;
1734 }
1735 return -1;
1736 }
1737
1738 // uncached_lookup_method searches both the local class methods array and all
1739 // superclasses methods arrays, skipping any overpass methods in superclasses.
1740 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1741 const Symbol* signature,
1742 OverpassLookupMode overpass_mode) const {
1743 OverpassLookupMode overpass_local_mode = overpass_mode;
1744 const Klass* klass = this;
1745 while (klass != NULL) {
1746 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1747 signature,
1748 overpass_local_mode,
1749 find_static,
1750 find_private);
1751 if (method != NULL) {
1752 return method;
1753 }
1754 klass = klass->super();
1755 overpass_local_mode = skip_overpass; // Always ignore overpass methods in superclasses
1756 }
1757 return NULL;
1758 }
1759
1760 #ifdef ASSERT
1761 // search through class hierarchy and return true if this class or
1762 // one of the superclasses was redefined
1763 bool InstanceKlass::has_redefined_this_or_super() const {
1764 const Klass* klass = this;
1765 while (klass != NULL) {
1766 if (InstanceKlass::cast(klass)->has_been_redefined()) {
1767 return true;
1768 }
1769 klass = klass->super();
1770 }
1771 return false;
1772 }
1773 #endif
1774
1775 // lookup a method in the default methods list then in all transitive interfaces
1776 // Do NOT return private or static methods
1777 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1778 Symbol* signature) const {
1779 Method* m = NULL;
1780 if (default_methods() != NULL) {
1781 m = find_method(default_methods(), name, signature);
1782 }
1783 // Look up interfaces
1784 if (m == NULL) {
1785 m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1786 }
1787 return m;
1788 }
1789
1790 // lookup a method in all the interfaces that this class implements
1791 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1792 // They should only be found in the initial InterfaceMethodRef
1793 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1794 Symbol* signature,
1795 DefaultsLookupMode defaults_mode) const {
1796 Array<Klass*>* all_ifs = transitive_interfaces();
1797 int num_ifs = all_ifs->length();
1798 InstanceKlass *ik = NULL;
1799 for (int i = 0; i < num_ifs; i++) {
1800 ik = InstanceKlass::cast(all_ifs->at(i));
1801 Method* m = ik->lookup_method(name, signature);
1802 if (m != NULL && m->is_public() && !m->is_static() &&
1803 ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1804 return m;
1805 }
1806 }
1807 return NULL;
1808 }
1809
1810 /* jni_id_for_impl for jfieldIds only */
1811 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1812 MutexLocker ml(JfieldIdCreation_lock);
1813 // Retry lookup after we got the lock
1814 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1815 if (probe == NULL) {
1816 // Slow case, allocate new static field identifier
1817 probe = new JNIid(this, offset, jni_ids());
1818 set_jni_ids(probe);
1819 }
1820 return probe;
1821 }
1822
1823
1824 /* jni_id_for for jfieldIds only */
1825 JNIid* InstanceKlass::jni_id_for(int offset) {
1826 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1827 if (probe == NULL) {
1828 probe = jni_id_for_impl(offset);
1829 }
1830 return probe;
1831 }
1832
1833 u2 InstanceKlass::enclosing_method_data(int offset) const {
1834 const Array<jushort>* const inner_class_list = inner_classes();
1835 if (inner_class_list == NULL) {
1836 return 0;
1837 }
1838 const int length = inner_class_list->length();
1839 if (length % inner_class_next_offset == 0) {
1840 return 0;
1841 }
1842 const int index = length - enclosing_method_attribute_size;
1843 assert(offset < enclosing_method_attribute_size, "invalid offset");
1844 return inner_class_list->at(index + offset);
1845 }
1846
1847 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1848 u2 method_index) {
1849 Array<jushort>* inner_class_list = inner_classes();
1850 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1851 int length = inner_class_list->length();
1852 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1853 int index = length - enclosing_method_attribute_size;
1854 inner_class_list->at_put(
1855 index + enclosing_method_class_index_offset, class_index);
1856 inner_class_list->at_put(
1857 index + enclosing_method_method_index_offset, method_index);
1858 }
1859 }
1860
1861 // Lookup or create a jmethodID.
1862 // This code is called by the VMThread and JavaThreads so the
1863 // locking has to be done very carefully to avoid deadlocks
1864 // and/or other cache consistency problems.
1865 //
1866 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
1867 size_t idnum = (size_t)method_h->method_idnum();
1868 jmethodID* jmeths = methods_jmethod_ids_acquire();
1869 size_t length = 0;
1870 jmethodID id = NULL;
1871
1872 // We use a double-check locking idiom here because this cache is
1873 // performance sensitive. In the normal system, this cache only
1874 // transitions from NULL to non-NULL which is safe because we use
1875 // release_set_methods_jmethod_ids() to advertise the new cache.
1876 // A partially constructed cache should never be seen by a racing
1877 // thread. We also use release_store() to save a new jmethodID
1878 // in the cache so a partially constructed jmethodID should never be
1879 // seen either. Cache reads of existing jmethodIDs proceed without a
1880 // lock, but cache writes of a new jmethodID requires uniqueness and
1881 // creation of the cache itself requires no leaks so a lock is
1882 // generally acquired in those two cases.
1883 //
1884 // If the RedefineClasses() API has been used, then this cache can
1885 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1886 // Cache creation requires no leaks and we require safety between all
1887 // cache accesses and freeing of the old cache so a lock is generally
1888 // acquired when the RedefineClasses() API has been used.
1889
1890 if (jmeths != NULL) {
1891 // the cache already exists
1892 if (!idnum_can_increment()) {
1893 // the cache can't grow so we can just get the current values
1894 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1895 } else {
1896 // cache can grow so we have to be more careful
1897 if (Threads::number_of_threads() == 0 ||
1898 SafepointSynchronize::is_at_safepoint()) {
1899 // we're single threaded or at a safepoint - no locking needed
1900 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1901 } else {
1902 MutexLocker ml(JmethodIdCreation_lock);
1903 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1904 }
1905 }
1906 }
1907 // implied else:
1908 // we need to allocate a cache so default length and id values are good
1909
1910 if (jmeths == NULL || // no cache yet
1911 length <= idnum || // cache is too short
1912 id == NULL) { // cache doesn't contain entry
1913
1914 // This function can be called by the VMThread so we have to do all
1915 // things that might block on a safepoint before grabbing the lock.
1916 // Otherwise, we can deadlock with the VMThread or have a cache
1917 // consistency issue. These vars keep track of what we might have
1918 // to free after the lock is dropped.
1919 jmethodID to_dealloc_id = NULL;
1920 jmethodID* to_dealloc_jmeths = NULL;
1921
1922 // may not allocate new_jmeths or use it if we allocate it
1923 jmethodID* new_jmeths = NULL;
1924 if (length <= idnum) {
1925 // allocate a new cache that might be used
1926 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1927 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1928 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1929 // cache size is stored in element[0], other elements offset by one
1930 new_jmeths[0] = (jmethodID)size;
1931 }
1932
1933 // allocate a new jmethodID that might be used
1934 jmethodID new_id = NULL;
1935 if (method_h->is_old() && !method_h->is_obsolete()) {
1936 // The method passed in is old (but not obsolete), we need to use the current version
1937 Method* current_method = method_with_idnum((int)idnum);
1938 assert(current_method != NULL, "old and but not obsolete, so should exist");
1939 new_id = Method::make_jmethod_id(class_loader_data(), current_method);
1940 } else {
1941 // It is the current version of the method or an obsolete method,
1942 // use the version passed in
1943 new_id = Method::make_jmethod_id(class_loader_data(), method_h());
1944 }
1945
1946 if (Threads::number_of_threads() == 0 ||
1947 SafepointSynchronize::is_at_safepoint()) {
1948 // we're single threaded or at a safepoint - no locking needed
1949 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1950 &to_dealloc_id, &to_dealloc_jmeths);
1951 } else {
1952 MutexLocker ml(JmethodIdCreation_lock);
1953 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1954 &to_dealloc_id, &to_dealloc_jmeths);
1955 }
1956
1957 // The lock has been dropped so we can free resources.
1958 // Free up either the old cache or the new cache if we allocated one.
1959 if (to_dealloc_jmeths != NULL) {
1960 FreeHeap(to_dealloc_jmeths);
1961 }
1962 // free up the new ID since it wasn't needed
1963 if (to_dealloc_id != NULL) {
1964 Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
1965 }
1966 }
1967 return id;
1968 }
1969
1970 // Figure out how many jmethodIDs haven't been allocated, and make
1971 // sure space for them is pre-allocated. This makes getting all
1972 // method ids much, much faster with classes with more than 8
1973 // methods, and has a *substantial* effect on performance with jvmti
1974 // code that loads all jmethodIDs for all classes.
1975 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1976 int new_jmeths = 0;
1977 int length = methods()->length();
1978 for (int index = start_offset; index < length; index++) {
1979 Method* m = methods()->at(index);
1980 jmethodID id = m->find_jmethod_id_or_null();
1981 if (id == NULL) {
1982 new_jmeths++;
1983 }
1984 }
1985 if (new_jmeths != 0) {
1986 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1987 }
1988 }
1989
1990 // Common code to fetch the jmethodID from the cache or update the
1991 // cache with the new jmethodID. This function should never do anything
1992 // that causes the caller to go to a safepoint or we can deadlock with
1993 // the VMThread or have cache consistency issues.
1994 //
1995 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1996 size_t idnum, jmethodID new_id,
1997 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1998 jmethodID** to_dealloc_jmeths_p) {
1999 assert(new_id != NULL, "sanity check");
2000 assert(to_dealloc_id_p != NULL, "sanity check");
2001 assert(to_dealloc_jmeths_p != NULL, "sanity check");
2002 assert(Threads::number_of_threads() == 0 ||
2003 SafepointSynchronize::is_at_safepoint() ||
2004 JmethodIdCreation_lock->owned_by_self(), "sanity check");
2005
2006 // reacquire the cache - we are locked, single threaded or at a safepoint
2007 jmethodID* jmeths = methods_jmethod_ids_acquire();
2008 jmethodID id = NULL;
2009 size_t length = 0;
2010
2011 if (jmeths == NULL || // no cache yet
2012 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
2013 if (jmeths != NULL) {
2014 // copy any existing entries from the old cache
2015 for (size_t index = 0; index < length; index++) {
2016 new_jmeths[index+1] = jmeths[index+1];
2017 }
2018 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
2019 }
2020 release_set_methods_jmethod_ids(jmeths = new_jmeths);
2021 } else {
2022 // fetch jmethodID (if any) from the existing cache
2023 id = jmeths[idnum+1];
2024 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
2025 }
2026 if (id == NULL) {
2027 // No matching jmethodID in the existing cache or we have a new
2028 // cache or we just grew the cache. This cache write is done here
2029 // by the first thread to win the foot race because a jmethodID
2030 // needs to be unique once it is generally available.
2031 id = new_id;
2032
2033 // The jmethodID cache can be read while unlocked so we have to
2034 // make sure the new jmethodID is complete before installing it
2035 // in the cache.
2036 OrderAccess::release_store(&jmeths[idnum+1], id);
2037 } else {
2038 *to_dealloc_id_p = new_id; // save new id for later delete
2039 }
2040 return id;
2041 }
2042
2043
2044 // Common code to get the jmethodID cache length and the jmethodID
2045 // value at index idnum if there is one.
2046 //
2047 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
2048 size_t idnum, size_t *length_p, jmethodID* id_p) {
2049 assert(cache != NULL, "sanity check");
2050 assert(length_p != NULL, "sanity check");
2051 assert(id_p != NULL, "sanity check");
2052
2053 // cache size is stored in element[0], other elements offset by one
2054 *length_p = (size_t)cache[0];
2055 if (*length_p <= idnum) { // cache is too short
2056 *id_p = NULL;
2057 } else {
2058 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
2059 }
2060 }
2061
2062
2063 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
2064 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2065 size_t idnum = (size_t)method->method_idnum();
2066 jmethodID* jmeths = methods_jmethod_ids_acquire();
2067 size_t length; // length assigned as debugging crumb
2068 jmethodID id = NULL;
2069 if (jmeths != NULL && // If there is a cache
2070 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
2071 id = jmeths[idnum+1]; // Look up the id (may be NULL)
2072 }
2073 return id;
2074 }
2075
2076 inline DependencyContext InstanceKlass::dependencies() {
2077 DependencyContext dep_context(&_dep_context);
2078 return dep_context;
2079 }
2080
2081 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
2082 return dependencies().mark_dependent_nmethods(changes);
2083 }
2084
2085 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2086 dependencies().add_dependent_nmethod(nm);
2087 }
2088
2089 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
2090 dependencies().remove_dependent_nmethod(nm, delete_immediately);
2091 }
2092
2093 #ifndef PRODUCT
2094 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2095 dependencies().print_dependent_nmethods(verbose);
2096 }
2097
2098 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2099 return dependencies().is_dependent_nmethod(nm);
2100 }
2101 #endif //PRODUCT
2102
2103 void InstanceKlass::clean_weak_instanceklass_links(BoolObjectClosure* is_alive) {
2104 clean_implementors_list(is_alive);
2105 clean_method_data(is_alive);
2106
2107 // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here.
2108 DependencyContext dep_context(&_dep_context);
2109 dep_context.expunge_stale_entries();
2110 }
2111
2112 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
2113 assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
2114 if (is_interface()) {
2115 if (ClassUnloading) {
2116 Klass* impl = implementor();
2117 if (impl != NULL) {
2118 if (!impl->is_loader_alive(is_alive)) {
2119 // remove this guy
2120 Klass** klass = adr_implementor();
2121 assert(klass != NULL, "null klass");
2122 if (klass != NULL) {
2123 *klass = NULL;
2124 }
2125 }
2126 }
2127 }
2128 }
2129 }
2130
2131 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
2132 for (int m = 0; m < methods()->length(); m++) {
2133 MethodData* mdo = methods()->at(m)->method_data();
2134 if (mdo != NULL) {
2135 mdo->clean_method_data(is_alive);
2136 }
2137 }
2138 }
2139
2140 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
2141 if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
2142 ResourceMark rm;
2143 log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
2144 return false;
2145 }
2146
2147 Array<Klass*>* local_interfaces = this->local_interfaces();
2148 if (local_interfaces != NULL) {
2149 int length = local_interfaces->length();
2150 for (int i = 0; i < length; i++) {
2151 InstanceKlass* intf = InstanceKlass::cast(local_interfaces->at(i));
2152 if (!intf->has_passed_fingerprint_check()) {
2153 ResourceMark rm;
2154 log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
2155 return false;
2156 }
2157 }
2158 }
2159
2160 return true;
2161 }
2162
2163 bool InstanceKlass::should_store_fingerprint(bool is_anonymous) {
2164 #if INCLUDE_AOT
2165 // We store the fingerprint into the InstanceKlass only in the following 2 cases:
2166 if (CalculateClassFingerprint) {
2167 // (1) We are running AOT to generate a shared library.
2168 return true;
2169 }
2170 if (DumpSharedSpaces) {
2171 // (2) We are running -Xshare:dump to create a shared archive
2172 return true;
2173 }
2174 if (UseAOT && is_anonymous) {
2175 // (3) We are using AOT code from a shared library and see an anonymous class
2176 return true;
2177 }
2178 #endif
2179
2180 // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
2181 // but do not store the 64-bit fingerprint to save space.
2182 return false;
2183 }
2184
2185 bool InstanceKlass::has_stored_fingerprint() const {
2186 #if INCLUDE_AOT
2187 return should_store_fingerprint() || is_shared();
2188 #else
2189 return false;
2190 #endif
2191 }
2192
2193 uint64_t InstanceKlass::get_stored_fingerprint() const {
2194 address adr = adr_fingerprint();
2195 if (adr != NULL) {
2196 return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
2197 }
2198 return 0;
2199 }
2200
2201 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
2202 address adr = adr_fingerprint();
2203 if (adr != NULL) {
2204 Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2205
2206 ResourceMark rm;
2207 log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2208 }
2209 }
2210
2211 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2212 Klass::metaspace_pointers_do(it);
2213
2214 if (log_is_enabled(Trace, cds)) {
2215 ResourceMark rm;
2216 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2217 }
2218
2219 it->push(&_annotations);
2220 it->push((Klass**)&_array_klasses);
2221 it->push(&_constants);
2222 it->push(&_inner_classes);
2223 it->push(&_array_name);
2224 #if INCLUDE_JVMTI
2225 it->push(&_previous_versions);
2226 #endif
2227 it->push(&_methods);
2228 it->push(&_default_methods);
2229 it->push(&_local_interfaces);
2230 it->push(&_transitive_interfaces);
2231 it->push(&_method_ordering);
2232 it->push(&_default_vtable_indices);
2233 it->push(&_fields);
2234
2235 if (itable_length() > 0) {
2236 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2237 int method_table_offset_in_words = ioe->offset()/wordSize;
2238 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2239 / itableOffsetEntry::size();
2240
2241 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2242 if (ioe->interface_klass() != NULL) {
2243 it->push(ioe->interface_klass_addr());
2244 itableMethodEntry* ime = ioe->first_method_entry(this);
2245 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2246 for (int index = 0; index < n; index ++) {
2247 it->push(ime[index].method_addr());
2248 }
2249 }
2250 }
2251 }
2252
2253 it->push(&_nest_members);
2254 }
2255
2256 void InstanceKlass::remove_unshareable_info() {
2257 Klass::remove_unshareable_info();
2258
2259 if (is_in_error_state()) {
2260 // Classes are attempted to link during dumping and may fail,
2261 // but these classes are still in the dictionary and class list in CLD.
2262 // Check in_error state first because in_error is > linked state, so
2263 // is_linked() is true.
2264 // If there's a linking error, there is nothing else to remove.
2265 return;
2266 }
2267
2268 // Unlink the class
2269 if (is_linked()) {
2270 unlink_class();
2271 }
2272 init_implementor();
2273
2274 constants()->remove_unshareable_info();
2275
2276 for (int i = 0; i < methods()->length(); i++) {
2277 Method* m = methods()->at(i);
2278 m->remove_unshareable_info();
2279 }
2280
2281 // do array classes also.
2282 if (array_klasses() != NULL) {
2283 array_klasses()->remove_unshareable_info();
2284 }
2285
2286 // These are not allocated from metaspace, but they should should all be empty
2287 // during dump time, so we don't need to worry about them in InstanceKlass::iterate().
2288 guarantee(_source_debug_extension == NULL, "must be");
2289 guarantee(_dep_context == DependencyContext::EMPTY, "must be");
2290 guarantee(_osr_nmethods_head == NULL, "must be");
2291
2292 #if INCLUDE_JVMTI
2293 guarantee(_breakpoints == NULL, "must be");
2294 guarantee(_previous_versions == NULL, "must be");
2295 #endif
2296
2297 _init_thread = NULL;
2298 _methods_jmethod_ids = NULL;
2299 _jni_ids = NULL;
2300 _oop_map_cache = NULL;
2301 // clear _nest_host to ensure re-load at runtime
2302 _nest_host = NULL;
2303 }
2304
2305 void InstanceKlass::remove_java_mirror() {
2306 Klass::remove_java_mirror();
2307
2308 // do array classes also.
2309 if (array_klasses() != NULL) {
2310 array_klasses()->remove_java_mirror();
2311 }
2312 }
2313
2314 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2315 set_package(loader_data, CHECK);
2316 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2317
2318 Array<Method*>* methods = this->methods();
2319 int num_methods = methods->length();
2320 for (int index2 = 0; index2 < num_methods; ++index2) {
2321 methodHandle m(THREAD, methods->at(index2));
2322 m->restore_unshareable_info(CHECK);
2323 }
2324 if (JvmtiExport::has_redefined_a_class()) {
2325 // Reinitialize vtable because RedefineClasses may have changed some
2326 // entries in this vtable for super classes so the CDS vtable might
2327 // point to old or obsolete entries. RedefineClasses doesn't fix up
2328 // vtables in the shared system dictionary, only the main one.
2329 // It also redefines the itable too so fix that too.
2330 ResourceMark rm(THREAD);
2331 vtable().initialize_vtable(false, CHECK);
2332 itable().initialize_itable(false, CHECK);
2333 }
2334
2335 // restore constant pool resolved references
2336 constants()->restore_unshareable_info(CHECK);
2337
2338 if (array_klasses() != NULL) {
2339 // Array classes have null protection domain.
2340 // --> see ArrayKlass::complete_create_array_klass()
2341 array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2342 }
2343 }
2344
2345 // returns true IFF is_in_error_state() has been changed as a result of this call.
2346 bool InstanceKlass::check_sharing_error_state() {
2347 assert(DumpSharedSpaces, "should only be called during dumping");
2348 bool old_state = is_in_error_state();
2349
2350 if (!is_in_error_state()) {
2351 bool bad = false;
2352 for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2353 if (sup->is_in_error_state()) {
2354 bad = true;
2355 break;
2356 }
2357 }
2358 if (!bad) {
2359 Array<Klass*>* interfaces = transitive_interfaces();
2360 for (int i = 0; i < interfaces->length(); i++) {
2361 Klass* iface = interfaces->at(i);
2362 if (InstanceKlass::cast(iface)->is_in_error_state()) {
2363 bad = true;
2364 break;
2365 }
2366 }
2367 }
2368
2369 if (bad) {
2370 set_in_error_state();
2371 }
2372 }
2373
2374 return (old_state != is_in_error_state());
2375 }
2376
2377 #if INCLUDE_JVMTI
2378 static void clear_all_breakpoints(Method* m) {
2379 m->clear_all_breakpoints();
2380 }
2381 #endif
2382
2383 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2384 // notify the debugger
2385 if (JvmtiExport::should_post_class_unload()) {
2386 JvmtiExport::post_class_unload(ik);
2387 }
2388
2389 // notify ClassLoadingService of class unload
2390 ClassLoadingService::notify_class_unloaded(ik);
2391 }
2392
2393 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2394 // Clean up C heap
2395 ik->release_C_heap_structures();
2396 ik->constants()->release_C_heap_structures();
2397 }
2398
2399 void InstanceKlass::release_C_heap_structures() {
2400 // Can't release the constant pool here because the constant pool can be
2401 // deallocated separately from the InstanceKlass for default methods and
2402 // redefine classes.
2403
2404 // Deallocate oop map cache
2405 if (_oop_map_cache != NULL) {
2406 delete _oop_map_cache;
2407 _oop_map_cache = NULL;
2408 }
2409
2410 // Deallocate JNI identifiers for jfieldIDs
2411 JNIid::deallocate(jni_ids());
2412 set_jni_ids(NULL);
2413
2414 jmethodID* jmeths = methods_jmethod_ids_acquire();
2415 if (jmeths != (jmethodID*)NULL) {
2416 release_set_methods_jmethod_ids(NULL);
2417 FreeHeap(jmeths);
2418 }
2419
2420 // Release dependencies.
2421 // It is desirable to use DC::remove_all_dependents() here, but, unfortunately,
2422 // it is not safe (see JDK-8143408). The problem is that the klass dependency
2423 // context can contain live dependencies, since there's a race between nmethod &
2424 // klass unloading. If the klass is dead when nmethod unloading happens, relevant
2425 // dependencies aren't removed from the context associated with the class (see
2426 // nmethod::flush_dependencies). It ends up during klass unloading as seemingly
2427 // live dependencies pointing to unloaded nmethods and causes a crash in
2428 // DC::remove_all_dependents() when it touches unloaded nmethod.
2429 dependencies().wipe();
2430
2431 #if INCLUDE_JVMTI
2432 // Deallocate breakpoint records
2433 if (breakpoints() != 0x0) {
2434 methods_do(clear_all_breakpoints);
2435 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2436 }
2437
2438 // deallocate the cached class file
2439 if (_cached_class_file != NULL && !MetaspaceShared::is_in_shared_space(_cached_class_file)) {
2440 os::free(_cached_class_file);
2441 _cached_class_file = NULL;
2442 }
2443 #endif
2444
2445 // Decrement symbol reference counts associated with the unloaded class.
2446 if (_name != NULL) _name->decrement_refcount();
2447 // unreference array name derived from this class name (arrays of an unloaded
2448 // class can't be referenced anymore).
2449 if (_array_name != NULL) _array_name->decrement_refcount();
2450 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2451
2452 assert(_total_instanceKlass_count >= 1, "Sanity check");
2453 Atomic::dec(&_total_instanceKlass_count);
2454 }
2455
2456 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2457 if (array == NULL) {
2458 _source_debug_extension = NULL;
2459 } else {
2460 // Adding one to the attribute length in order to store a null terminator
2461 // character could cause an overflow because the attribute length is
2462 // already coded with an u4 in the classfile, but in practice, it's
2463 // unlikely to happen.
2464 assert((length+1) > length, "Overflow checking");
2465 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2466 for (int i = 0; i < length; i++) {
2467 sde[i] = array[i];
2468 }
2469 sde[length] = '\0';
2470 _source_debug_extension = sde;
2471 }
2472 }
2473
2474 address InstanceKlass::static_field_addr(int offset) {
2475 return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
2476 }
2477
2478
2479 const char* InstanceKlass::signature_name() const {
2480 int hash_len = 0;
2481 char hash_buf[40];
2482
2483 // If this is an anonymous class, append a hash to make the name unique
2484 if (is_anonymous()) {
2485 intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2486 jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2487 hash_len = (int)strlen(hash_buf);
2488 }
2489
2490 // Get the internal name as a c string
2491 const char* src = (const char*) (name()->as_C_string());
2492 const int src_length = (int)strlen(src);
2493
2494 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2495
2496 // Add L as type indicator
2497 int dest_index = 0;
2498 dest[dest_index++] = 'L';
2499
2500 // Add the actual class name
2501 for (int src_index = 0; src_index < src_length; ) {
2502 dest[dest_index++] = src[src_index++];
2503 }
2504
2505 // If we have a hash, append it
2506 for (int hash_index = 0; hash_index < hash_len; ) {
2507 dest[dest_index++] = hash_buf[hash_index++];
2508 }
2509
2510 // Add the semicolon and the NULL
2511 dest[dest_index++] = ';';
2512 dest[dest_index] = '\0';
2513 return dest;
2514 }
2515
2516 // Used to obtain the package name from a fully qualified class name.
2517 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2518 if (name == NULL) {
2519 return NULL;
2520 } else {
2521 if (name->utf8_length() <= 0) {
2522 return NULL;
2523 }
2524 ResourceMark rm;
2525 const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2526 if (package_name == NULL) {
2527 return NULL;
2528 }
2529 Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD);
2530 return pkg_name;
2531 }
2532 }
2533
2534 ModuleEntry* InstanceKlass::module() const {
2535 if (!in_unnamed_package()) {
2536 return _package_entry->module();
2537 }
2538 const Klass* host = host_klass();
2539 if (host == NULL) {
2540 return class_loader_data()->unnamed_module();
2541 }
2542 return host->class_loader_data()->unnamed_module();
2543 }
2544
2545 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2546
2547 // ensure java/ packages only loaded by boot or platform builtin loaders
2548 Handle class_loader(THREAD, loader_data->class_loader());
2549 check_prohibited_package(name(), class_loader, CHECK);
2550
2551 TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2552
2553 if (pkg_name != NULL && loader_data != NULL) {
2554
2555 // Find in class loader's package entry table.
2556 _package_entry = loader_data->packages()->lookup_only(pkg_name);
2557
2558 // If the package name is not found in the loader's package
2559 // entry table, it is an indication that the package has not
2560 // been defined. Consider it defined within the unnamed module.
2561 if (_package_entry == NULL) {
2562 ResourceMark rm;
2563
2564 if (!ModuleEntryTable::javabase_defined()) {
2565 // Before java.base is defined during bootstrapping, define all packages in
2566 // the java.base module. If a non-java.base package is erroneously placed
2567 // in the java.base module it will be caught later when java.base
2568 // is defined by ModuleEntryTable::verify_javabase_packages check.
2569 assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2570 _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2571 } else {
2572 assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2573 _package_entry = loader_data->packages()->lookup(pkg_name,
2574 loader_data->unnamed_module());
2575 }
2576
2577 // A package should have been successfully created
2578 assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2579 name()->as_C_string(), loader_data->loader_name());
2580 }
2581
2582 if (log_is_enabled(Debug, module)) {
2583 ResourceMark rm;
2584 ModuleEntry* m = _package_entry->module();
2585 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2586 external_name(),
2587 pkg_name->as_C_string(),
2588 loader_data->loader_name(),
2589 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2590 }
2591 } else {
2592 ResourceMark rm;
2593 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2594 external_name(),
2595 (loader_data != NULL) ? loader_data->loader_name() : "NULL",
2596 UNNAMED_MODULE);
2597 }
2598 }
2599
2600
2601 // different versions of is_same_class_package
2602
2603 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2604 oop classloader1 = this->class_loader();
2605 PackageEntry* classpkg1 = this->package();
2606 if (class2->is_objArray_klass()) {
2607 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2608 }
2609
2610 oop classloader2;
2611 PackageEntry* classpkg2;
2612 if (class2->is_instance_klass()) {
2613 classloader2 = class2->class_loader();
2614 classpkg2 = class2->package();
2615 } else {
2616 assert(class2->is_typeArray_klass(), "should be type array");
2617 classloader2 = NULL;
2618 classpkg2 = NULL;
2619 }
2620
2621 // Same package is determined by comparing class loader
2622 // and package entries. Both must be the same. This rule
2623 // applies even to classes that are defined in the unnamed
2624 // package, they still must have the same class loader.
2625 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2626 return true;
2627 }
2628
2629 return false;
2630 }
2631
2632 // return true if this class and other_class are in the same package. Classloader
2633 // and classname information is enough to determine a class's package
2634 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2635 const Symbol* other_class_name) const {
2636 if (class_loader() != other_class_loader) {
2637 return false;
2638 }
2639 if (name()->fast_compare(other_class_name) == 0) {
2640 return true;
2641 }
2642
2643 {
2644 ResourceMark rm;
2645
2646 bool bad_class_name = false;
2647 const char* other_pkg =
2648 ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2649 if (bad_class_name) {
2650 return false;
2651 }
2652 // Check that package_from_name() returns NULL, not "", if there is no package.
2653 assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2654
2655 const Symbol* const this_package_name =
2656 this->package() != NULL ? this->package()->name() : NULL;
2657
2658 if (this_package_name == NULL || other_pkg == NULL) {
2659 // One of the two doesn't have a package. Only return true if the other
2660 // one also doesn't have a package.
2661 return (const char*)this_package_name == other_pkg;
2662 }
2663
2664 // Check if package is identical
2665 return this_package_name->equals(other_pkg);
2666 }
2667 }
2668
2669 // Returns true iff super_method can be overridden by a method in targetclassname
2670 // See JLS 3rd edition 8.4.6.1
2671 // Assumes name-signature match
2672 // "this" is InstanceKlass of super_method which must exist
2673 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2674 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2675 // Private methods can not be overridden
2676 if (super_method->is_private()) {
2677 return false;
2678 }
2679 // If super method is accessible, then override
2680 if ((super_method->is_protected()) ||
2681 (super_method->is_public())) {
2682 return true;
2683 }
2684 // Package-private methods are not inherited outside of package
2685 assert(super_method->is_package_private(), "must be package private");
2686 return(is_same_class_package(targetclassloader(), targetclassname));
2687 }
2688
2689 // Only boot and platform class loaders can define classes in "java/" packages.
2690 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2691 Handle class_loader,
2692 TRAPS) {
2693 if (!class_loader.is_null() &&
2694 !SystemDictionary::is_platform_class_loader(class_loader()) &&
2695 class_name != NULL) {
2696 ResourceMark rm(THREAD);
2697 char* name = class_name->as_C_string();
2698 if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2699 TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2700 assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2701 name = pkg_name->as_C_string();
2702 const char* class_loader_name = SystemDictionary::loader_name(class_loader());
2703 StringUtils::replace_no_expand(name, "/", ".");
2704 const char* msg_text1 = "Class loader (instance of): ";
2705 const char* msg_text2 = " tried to load prohibited package name: ";
2706 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2707 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2708 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2709 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2710 }
2711 }
2712 return;
2713 }
2714
2715 // tell if two classes have the same enclosing class (at package level)
2716 bool InstanceKlass::is_same_package_member(const Klass* class2, TRAPS) const {
2717 if (class2 == this) return true;
2718 if (!class2->is_instance_klass()) return false;
2719
2720 // must be in same package before we try anything else
2721 if (!is_same_class_package(class2))
2722 return false;
2723
2724 // As long as there is an outer_this.getEnclosingClass,
2725 // shift the search outward.
2726 const InstanceKlass* outer_this = this;
2727 for (;;) {
2728 // As we walk along, look for equalities between outer_this and class2.
2729 // Eventually, the walks will terminate as outer_this stops
2730 // at the top-level class around the original class.
2731 bool ignore_inner_is_member;
2732 const Klass* next = outer_this->compute_enclosing_class(&ignore_inner_is_member,
2733 CHECK_false);
2734 if (next == NULL) break;
2735 if (next == class2) return true;
2736 outer_this = InstanceKlass::cast(next);
2737 }
2738
2739 // Now do the same for class2.
2740 const InstanceKlass* outer2 = InstanceKlass::cast(class2);
2741 for (;;) {
2742 bool ignore_inner_is_member;
2743 Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2744 CHECK_false);
2745 if (next == NULL) break;
2746 // Might as well check the new outer against all available values.
2747 if (next == this) return true;
2748 if (next == outer_this) return true;
2749 outer2 = InstanceKlass::cast(next);
2750 }
2751
2752 // If by this point we have not found an equality between the
2753 // two classes, we know they are in separate package members.
2754 return false;
2755 }
2756
2757 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2758 constantPoolHandle i_cp(THREAD, constants());
2759 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2760 int ioff = iter.inner_class_info_index();
2761 if (ioff != 0) {
2762 // Check to see if the name matches the class we're looking for
2763 // before attempting to find the class.
2764 if (i_cp->klass_name_at_matches(this, ioff)) {
2765 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2766 if (this == inner_klass) {
2767 *ooff = iter.outer_class_info_index();
2768 *noff = iter.inner_name_index();
2769 return true;
2770 }
2771 }
2772 }
2773 }
2774 return false;
2775 }
2776
2777 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2778 InstanceKlass* outer_klass = NULL;
2779 *inner_is_member = false;
2780 int ooff = 0, noff = 0;
2781 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2782 if (has_inner_classes_attr) {
2783 constantPoolHandle i_cp(THREAD, constants());
2784 if (ooff != 0) {
2785 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2786 outer_klass = InstanceKlass::cast(ok);
2787 *inner_is_member = true;
2788 }
2789 if (NULL == outer_klass) {
2790 // It may be anonymous; try for that.
2791 int encl_method_class_idx = enclosing_method_class_index();
2792 if (encl_method_class_idx != 0) {
2793 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2794 outer_klass = InstanceKlass::cast(ok);
2795 *inner_is_member = false;
2796 }
2797 }
2798 }
2799
2800 // If no inner class attribute found for this class.
2801 if (NULL == outer_klass) return NULL;
2802
2803 // Throws an exception if outer klass has not declared k as an inner klass
2804 // We need evidence that each klass knows about the other, or else
2805 // the system could allow a spoof of an inner class to gain access rights.
2806 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2807 return outer_klass;
2808 }
2809
2810 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2811 jint access = access_flags().as_int();
2812
2813 // But check if it happens to be member class.
2814 InnerClassesIterator iter(this);
2815 for (; !iter.done(); iter.next()) {
2816 int ioff = iter.inner_class_info_index();
2817 // Inner class attribute can be zero, skip it.
2818 // Strange but true: JVM spec. allows null inner class refs.
2819 if (ioff == 0) continue;
2820
2821 // only look at classes that are already loaded
2822 // since we are looking for the flags for our self.
2823 Symbol* inner_name = constants()->klass_name_at(ioff);
2824 if (name() == inner_name) {
2825 // This is really a member class.
2826 access = iter.inner_access_flags();
2827 break;
2828 }
2829 }
2830 // Remember to strip ACC_SUPER bit
2831 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2832 }
2833
2834 jint InstanceKlass::jvmti_class_status() const {
2835 jint result = 0;
2836
2837 if (is_linked()) {
2838 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2839 }
2840
2841 if (is_initialized()) {
2842 assert(is_linked(), "Class status is not consistent");
2843 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2844 }
2845 if (is_in_error_state()) {
2846 result |= JVMTI_CLASS_STATUS_ERROR;
2847 }
2848 return result;
2849 }
2850
2851 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2852 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2853 int method_table_offset_in_words = ioe->offset()/wordSize;
2854 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2855 / itableOffsetEntry::size();
2856
2857 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2858 // If the interface isn't implemented by the receiver class,
2859 // the VM should throw IncompatibleClassChangeError.
2860 if (cnt >= nof_interfaces) {
2861 THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2862 }
2863
2864 Klass* ik = ioe->interface_klass();
2865 if (ik == holder) break;
2866 }
2867
2868 itableMethodEntry* ime = ioe->first_method_entry(this);
2869 Method* m = ime[index].method();
2870 if (m == NULL) {
2871 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2872 }
2873 return m;
2874 }
2875
2876
2877 #if INCLUDE_JVMTI
2878 // update default_methods for redefineclasses for methods that are
2879 // not yet in the vtable due to concurrent subclass define and superinterface
2880 // redefinition
2881 // Note: those in the vtable, should have been updated via adjust_method_entries
2882 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2883 // search the default_methods for uses of either obsolete or EMCP methods
2884 if (default_methods() != NULL) {
2885 for (int index = 0; index < default_methods()->length(); index ++) {
2886 Method* old_method = default_methods()->at(index);
2887 if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2888 continue; // skip uninteresting entries
2889 }
2890 assert(!old_method->is_deleted(), "default methods may not be deleted");
2891
2892 Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2893
2894 assert(new_method != NULL, "method_with_idnum() should not be NULL");
2895 assert(old_method != new_method, "sanity check");
2896
2897 default_methods()->at_put(index, new_method);
2898 if (log_is_enabled(Info, redefine, class, update)) {
2899 ResourceMark rm;
2900 if (!(*trace_name_printed)) {
2901 log_info(redefine, class, update)
2902 ("adjust: klassname=%s default methods from name=%s",
2903 external_name(), old_method->method_holder()->external_name());
2904 *trace_name_printed = true;
2905 }
2906 log_debug(redefine, class, update, vtables)
2907 ("default method update: %s(%s) ",
2908 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
2909 }
2910 }
2911 }
2912 }
2913 #endif // INCLUDE_JVMTI
2914
2915 // On-stack replacement stuff
2916 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2917 // only one compilation can be active
2918 {
2919 // This is a short non-blocking critical region, so the no safepoint check is ok.
2920 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2921 assert(n->is_osr_method(), "wrong kind of nmethod");
2922 n->set_osr_link(osr_nmethods_head());
2923 set_osr_nmethods_head(n);
2924 // Raise the highest osr level if necessary
2925 if (TieredCompilation) {
2926 Method* m = n->method();
2927 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2928 }
2929 }
2930
2931 // Get rid of the osr methods for the same bci that have lower levels.
2932 if (TieredCompilation) {
2933 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2934 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2935 if (inv != NULL && inv->is_in_use()) {
2936 inv->make_not_entrant();
2937 }
2938 }
2939 }
2940 }
2941
2942 // Remove osr nmethod from the list. Return true if found and removed.
2943 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
2944 // This is a short non-blocking critical region, so the no safepoint check is ok.
2945 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2946 assert(n->is_osr_method(), "wrong kind of nmethod");
2947 nmethod* last = NULL;
2948 nmethod* cur = osr_nmethods_head();
2949 int max_level = CompLevel_none; // Find the max comp level excluding n
2950 Method* m = n->method();
2951 // Search for match
2952 bool found = false;
2953 while(cur != NULL && cur != n) {
2954 if (TieredCompilation && m == cur->method()) {
2955 // Find max level before n
2956 max_level = MAX2(max_level, cur->comp_level());
2957 }
2958 last = cur;
2959 cur = cur->osr_link();
2960 }
2961 nmethod* next = NULL;
2962 if (cur == n) {
2963 found = true;
2964 next = cur->osr_link();
2965 if (last == NULL) {
2966 // Remove first element
2967 set_osr_nmethods_head(next);
2968 } else {
2969 last->set_osr_link(next);
2970 }
2971 }
2972 n->set_osr_link(NULL);
2973 if (TieredCompilation) {
2974 cur = next;
2975 while (cur != NULL) {
2976 // Find max level after n
2977 if (m == cur->method()) {
2978 max_level = MAX2(max_level, cur->comp_level());
2979 }
2980 cur = cur->osr_link();
2981 }
2982 m->set_highest_osr_comp_level(max_level);
2983 }
2984 return found;
2985 }
2986
2987 int InstanceKlass::mark_osr_nmethods(const Method* m) {
2988 // This is a short non-blocking critical region, so the no safepoint check is ok.
2989 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2990 nmethod* osr = osr_nmethods_head();
2991 int found = 0;
2992 while (osr != NULL) {
2993 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2994 if (osr->method() == m) {
2995 osr->mark_for_deoptimization();
2996 found++;
2997 }
2998 osr = osr->osr_link();
2999 }
3000 return found;
3001 }
3002
3003 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3004 // This is a short non-blocking critical region, so the no safepoint check is ok.
3005 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
3006 nmethod* osr = osr_nmethods_head();
3007 nmethod* best = NULL;
3008 while (osr != NULL) {
3009 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3010 // There can be a time when a c1 osr method exists but we are waiting
3011 // for a c2 version. When c2 completes its osr nmethod we will trash
3012 // the c1 version and only be able to find the c2 version. However
3013 // while we overflow in the c1 code at back branches we don't want to
3014 // try and switch to the same code as we are already running
3015
3016 if (osr->method() == m &&
3017 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3018 if (match_level) {
3019 if (osr->comp_level() == comp_level) {
3020 // Found a match - return it.
3021 return osr;
3022 }
3023 } else {
3024 if (best == NULL || (osr->comp_level() > best->comp_level())) {
3025 if (osr->comp_level() == CompLevel_highest_tier) {
3026 // Found the best possible - return it.
3027 return osr;
3028 }
3029 best = osr;
3030 }
3031 }
3032 }
3033 osr = osr->osr_link();
3034 }
3035 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
3036 return best;
3037 }
3038 return NULL;
3039 }
3040
3041 // -----------------------------------------------------------------------------------------------------
3042 // Printing
3043
3044 #ifndef PRODUCT
3045
3046 #define BULLET " - "
3047
3048 static const char* state_names[] = {
3049 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3050 };
3051
3052 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3053 for (int i = 0; i < len; i++) {
3054 intptr_t e = start[i];
3055 st->print("%d : " INTPTR_FORMAT, i, e);
3056 if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
3057 st->print(" ");
3058 ((Metadata*)e)->print_value_on(st);
3059 }
3060 st->cr();
3061 }
3062 }
3063
3064 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3065 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3066 }
3067
3068 void InstanceKlass::print_on(outputStream* st) const {
3069 assert(is_klass(), "must be klass");
3070 Klass::print_on(st);
3071
3072 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3073 st->print(BULLET"klass size: %d", size()); st->cr();
3074 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3075 st->print(BULLET"state: "); st->print_cr("%s", state_names[_init_state]);
3076 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3077 st->print(BULLET"super: "); super()->print_value_on_maybe_null(st); st->cr();
3078 st->print(BULLET"sub: ");
3079 Klass* sub = subklass();
3080 int n;
3081 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
3082 if (n < MaxSubklassPrintSize) {
3083 sub->print_value_on(st);
3084 st->print(" ");
3085 }
3086 }
3087 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3088 st->cr();
3089
3090 if (is_interface()) {
3091 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3092 if (nof_implementors() == 1) {
3093 st->print_cr(BULLET"implementor: ");
3094 st->print(" ");
3095 implementor()->print_value_on(st);
3096 st->cr();
3097 }
3098 }
3099
3100 st->print(BULLET"arrays: "); array_klasses()->print_value_on_maybe_null(st); st->cr();
3101 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3102 if (Verbose || WizardMode) {
3103 Array<Method*>* method_array = methods();
3104 for (int i = 0; i < method_array->length(); i++) {
3105 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3106 }
3107 }
3108 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3109 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3110 if (Verbose && default_methods() != NULL) {
3111 Array<Method*>* method_array = default_methods();
3112 for (int i = 0; i < method_array->length(); i++) {
3113 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3114 }
3115 }
3116 if (default_vtable_indices() != NULL) {
3117 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
3118 }
3119 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3120 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3121 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3122 if (class_loader_data() != NULL) {
3123 st->print(BULLET"class loader data: ");
3124 class_loader_data()->print_value_on(st);
3125 st->cr();
3126 }
3127 st->print(BULLET"host class: "); host_klass()->print_value_on_maybe_null(st); st->cr();
3128 if (source_file_name() != NULL) {
3129 st->print(BULLET"source file: ");
3130 source_file_name()->print_value_on(st);
3131 st->cr();
3132 }
3133 if (source_debug_extension() != NULL) {
3134 st->print(BULLET"source debug extension: ");
3135 st->print("%s", source_debug_extension());
3136 st->cr();
3137 }
3138 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
3139 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
3140 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
3141 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
3142 {
3143 bool have_pv = false;
3144 // previous versions are linked together through the InstanceKlass
3145 for (InstanceKlass* pv_node = previous_versions();
3146 pv_node != NULL;
3147 pv_node = pv_node->previous_versions()) {
3148 if (!have_pv)
3149 st->print(BULLET"previous version: ");
3150 have_pv = true;
3151 pv_node->constants()->print_value_on(st);
3152 }
3153 if (have_pv) st->cr();
3154 }
3155
3156 if (generic_signature() != NULL) {
3157 st->print(BULLET"generic signature: ");
3158 generic_signature()->print_value_on(st);
3159 st->cr();
3160 }
3161 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3162 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3163 st->print(BULLET"java mirror: "); java_mirror()->print_value_on(st); st->cr();
3164 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3165 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3166 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3167 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3168 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3169 FieldPrinter print_static_field(st);
3170 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3171 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3172 FieldPrinter print_nonstatic_field(st);
3173 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3174 ik->do_nonstatic_fields(&print_nonstatic_field);
3175
3176 st->print(BULLET"non-static oop maps: ");
3177 OopMapBlock* map = start_of_nonstatic_oop_maps();
3178 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3179 while (map < end_map) {
3180 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3181 map++;
3182 }
3183 st->cr();
3184 }
3185
3186 #endif //PRODUCT
3187
3188 void InstanceKlass::print_value_on(outputStream* st) const {
3189 assert(is_klass(), "must be klass");
3190 if (Verbose || WizardMode) access_flags().print_on(st);
3191 name()->print_value_on(st);
3192 }
3193
3194 #ifndef PRODUCT
3195
3196 void FieldPrinter::do_field(fieldDescriptor* fd) {
3197 _st->print(BULLET);
3198 if (_obj == NULL) {
3199 fd->print_on(_st);
3200 _st->cr();
3201 } else {
3202 fd->print_on_for(_st, _obj);
3203 _st->cr();
3204 }
3205 }
3206
3207
3208 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3209 Klass::oop_print_on(obj, st);
3210
3211 if (this == SystemDictionary::String_klass()) {
3212 typeArrayOop value = java_lang_String::value(obj);
3213 juint length = java_lang_String::length(obj);
3214 if (value != NULL &&
3215 value->is_typeArray() &&
3216 length <= (juint) value->length()) {
3217 st->print(BULLET"string: ");
3218 java_lang_String::print(obj, st);
3219 st->cr();
3220 if (!WizardMode) return; // that is enough
3221 }
3222 }
3223
3224 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3225 FieldPrinter print_field(st, obj);
3226 do_nonstatic_fields(&print_field);
3227
3228 if (this == SystemDictionary::Class_klass()) {
3229 st->print(BULLET"signature: ");
3230 java_lang_Class::print_signature(obj, st);
3231 st->cr();
3232 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3233 st->print(BULLET"fake entry for mirror: ");
3234 mirrored_klass->print_value_on_maybe_null(st);
3235 st->cr();
3236 Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3237 st->print(BULLET"fake entry for array: ");
3238 array_klass->print_value_on_maybe_null(st);
3239 st->cr();
3240 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3241 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3242 Klass* real_klass = java_lang_Class::as_Klass(obj);
3243 if (real_klass != NULL && real_klass->is_instance_klass()) {
3244 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3245 }
3246 } else if (this == SystemDictionary::MethodType_klass()) {
3247 st->print(BULLET"signature: ");
3248 java_lang_invoke_MethodType::print_signature(obj, st);
3249 st->cr();
3250 }
3251 }
3252
3253 #endif //PRODUCT
3254
3255 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3256 st->print("a ");
3257 name()->print_value_on(st);
3258 obj->print_address_on(st);
3259 if (this == SystemDictionary::String_klass()
3260 && java_lang_String::value(obj) != NULL) {
3261 ResourceMark rm;
3262 int len = java_lang_String::length(obj);
3263 int plen = (len < 24 ? len : 12);
3264 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3265 st->print(" = \"%s\"", str);
3266 if (len > plen)
3267 st->print("...[%d]", len);
3268 } else if (this == SystemDictionary::Class_klass()) {
3269 Klass* k = java_lang_Class::as_Klass(obj);
3270 st->print(" = ");
3271 if (k != NULL) {
3272 k->print_value_on(st);
3273 } else {
3274 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3275 st->print("%s", tname ? tname : "type?");
3276 }
3277 } else if (this == SystemDictionary::MethodType_klass()) {
3278 st->print(" = ");
3279 java_lang_invoke_MethodType::print_signature(obj, st);
3280 } else if (java_lang_boxing_object::is_instance(obj)) {
3281 st->print(" = ");
3282 java_lang_boxing_object::print(obj, st);
3283 } else if (this == SystemDictionary::LambdaForm_klass()) {
3284 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3285 if (vmentry != NULL) {
3286 st->print(" => ");
3287 vmentry->print_value_on(st);
3288 }
3289 } else if (this == SystemDictionary::MemberName_klass()) {
3290 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3291 if (vmtarget != NULL) {
3292 st->print(" = ");
3293 vmtarget->print_value_on(st);
3294 } else {
3295 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3296 st->print(".");
3297 java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3298 }
3299 }
3300 }
3301
3302 const char* InstanceKlass::internal_name() const {
3303 return external_name();
3304 }
3305
3306 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3307 const char* module_name,
3308 const ClassFileStream* cfs) const {
3309 if (!log_is_enabled(Info, class, load)) {
3310 return;
3311 }
3312
3313 ResourceMark rm;
3314 LogMessage(class, load) msg;
3315 stringStream info_stream;
3316
3317 // Name and class hierarchy info
3318 info_stream.print("%s", external_name());
3319
3320 // Source
3321 if (cfs != NULL) {
3322 if (cfs->source() != NULL) {
3323 if (module_name != NULL) {
3324 if (ClassLoader::is_modules_image(cfs->source())) {
3325 info_stream.print(" source: jrt:/%s", module_name);
3326 } else {
3327 info_stream.print(" source: %s", cfs->source());
3328 }
3329 } else {
3330 info_stream.print(" source: %s", cfs->source());
3331 }
3332 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3333 Thread* THREAD = Thread::current();
3334 Klass* caller =
3335 THREAD->is_Java_thread()
3336 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3337 : NULL;
3338 // caller can be NULL, for example, during a JVMTI VM_Init hook
3339 if (caller != NULL) {
3340 info_stream.print(" source: instance of %s", caller->external_name());
3341 } else {
3342 // source is unknown
3343 }
3344 } else {
3345 oop class_loader = loader_data->class_loader();
3346 info_stream.print(" source: %s", class_loader->klass()->external_name());
3347 }
3348 } else {
3349 info_stream.print(" source: shared objects file");
3350 }
3351
3352 msg.info("%s", info_stream.as_string());
3353
3354 if (log_is_enabled(Debug, class, load)) {
3355 stringStream debug_stream;
3356
3357 // Class hierarchy info
3358 debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3359 p2i(this), p2i(superklass()));
3360
3361 // Interfaces
3362 if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3363 debug_stream.print(" interfaces:");
3364 int length = local_interfaces()->length();
3365 for (int i = 0; i < length; i++) {
3366 debug_stream.print(" " INTPTR_FORMAT,
3367 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3368 }
3369 }
3370
3371 // Class loader
3372 debug_stream.print(" loader: [");
3373 loader_data->print_value_on(&debug_stream);
3374 debug_stream.print("]");
3375
3376 // Classfile checksum
3377 if (cfs) {
3378 debug_stream.print(" bytes: %d checksum: %08x",
3379 cfs->length(),
3380 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3381 cfs->length()));
3382 }
3383
3384 msg.debug("%s", debug_stream.as_string());
3385 }
3386 }
3387
3388 #if INCLUDE_SERVICES
3389 // Size Statistics
3390 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3391 Klass::collect_statistics(sz);
3392
3393 sz->_inst_size = wordSize * size_helper();
3394 sz->_vtab_bytes = wordSize * vtable_length();
3395 sz->_itab_bytes = wordSize * itable_length();
3396 sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3397
3398 int n = 0;
3399 n += (sz->_methods_array_bytes = sz->count_array(methods()));
3400 n += (sz->_method_ordering_bytes = sz->count_array(method_ordering()));
3401 n += (sz->_local_interfaces_bytes = sz->count_array(local_interfaces()));
3402 n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3403 n += (sz->_fields_bytes = sz->count_array(fields()));
3404 n += (sz->_inner_classes_bytes = sz->count_array(inner_classes()));
3405 n += (sz->_nest_members_bytes = sz->count_array(nest_members()));
3406 sz->_ro_bytes += n;
3407
3408 const ConstantPool* cp = constants();
3409 if (cp) {
3410 cp->collect_statistics(sz);
3411 }
3412
3413 const Annotations* anno = annotations();
3414 if (anno) {
3415 anno->collect_statistics(sz);
3416 }
3417
3418 const Array<Method*>* methods_array = methods();
3419 if (methods()) {
3420 for (int i = 0; i < methods_array->length(); i++) {
3421 Method* method = methods_array->at(i);
3422 if (method) {
3423 sz->_method_count ++;
3424 method->collect_statistics(sz);
3425 }
3426 }
3427 }
3428 }
3429 #endif // INCLUDE_SERVICES
3430
3431 // Verification
3432
3433 class VerifyFieldClosure: public OopClosure {
3434 protected:
3435 template <class T> void do_oop_work(T* p) {
3436 oop obj = oopDesc::load_decode_heap_oop(p);
3437 if (!oopDesc::is_oop_or_null(obj)) {
3438 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3439 Universe::print_on(tty);
3440 guarantee(false, "boom");
3441 }
3442 }
3443 public:
3444 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3445 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3446 };
3447
3448 void InstanceKlass::verify_on(outputStream* st) {
3449 #ifndef PRODUCT
3450 // Avoid redundant verifies, this really should be in product.
3451 if (_verify_count == Universe::verify_count()) return;
3452 _verify_count = Universe::verify_count();
3453 #endif
3454
3455 // Verify Klass
3456 Klass::verify_on(st);
3457
3458 // Verify that klass is present in ClassLoaderData
3459 guarantee(class_loader_data()->contains_klass(this),
3460 "this class isn't found in class loader data");
3461
3462 // Verify vtables
3463 if (is_linked()) {
3464 // $$$ This used to be done only for m/s collections. Doing it
3465 // always seemed a valid generalization. (DLD -- 6/00)
3466 vtable().verify(st);
3467 }
3468
3469 // Verify first subklass
3470 if (subklass() != NULL) {
3471 guarantee(subklass()->is_klass(), "should be klass");
3472 }
3473
3474 // Verify siblings
3475 Klass* super = this->super();
3476 Klass* sib = next_sibling();
3477 if (sib != NULL) {
3478 if (sib == this) {
3479 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3480 }
3481
3482 guarantee(sib->is_klass(), "should be klass");
3483 guarantee(sib->super() == super, "siblings should have same superklass");
3484 }
3485
3486 // Verify implementor fields
3487 Klass* im = implementor();
3488 if (im != NULL) {
3489 guarantee(is_interface(), "only interfaces should have implementor set");
3490 guarantee(im->is_klass(), "should be klass");
3491 guarantee(!im->is_interface() || im == this,
3492 "implementors cannot be interfaces");
3493 }
3494
3495 // Verify local interfaces
3496 if (local_interfaces()) {
3497 Array<Klass*>* local_interfaces = this->local_interfaces();
3498 for (int j = 0; j < local_interfaces->length(); j++) {
3499 Klass* e = local_interfaces->at(j);
3500 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3501 }
3502 }
3503
3504 // Verify transitive interfaces
3505 if (transitive_interfaces() != NULL) {
3506 Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3507 for (int j = 0; j < transitive_interfaces->length(); j++) {
3508 Klass* e = transitive_interfaces->at(j);
3509 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3510 }
3511 }
3512
3513 // Verify methods
3514 if (methods() != NULL) {
3515 Array<Method*>* methods = this->methods();
3516 for (int j = 0; j < methods->length(); j++) {
3517 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3518 }
3519 for (int j = 0; j < methods->length() - 1; j++) {
3520 Method* m1 = methods->at(j);
3521 Method* m2 = methods->at(j + 1);
3522 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3523 }
3524 }
3525
3526 // Verify method ordering
3527 if (method_ordering() != NULL) {
3528 Array<int>* method_ordering = this->method_ordering();
3529 int length = method_ordering->length();
3530 if (JvmtiExport::can_maintain_original_method_order() ||
3531 ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3532 guarantee(length == methods()->length(), "invalid method ordering length");
3533 jlong sum = 0;
3534 for (int j = 0; j < length; j++) {
3535 int original_index = method_ordering->at(j);
3536 guarantee(original_index >= 0, "invalid method ordering index");
3537 guarantee(original_index < length, "invalid method ordering index");
3538 sum += original_index;
3539 }
3540 // Verify sum of indices 0,1,...,length-1
3541 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3542 } else {
3543 guarantee(length == 0, "invalid method ordering length");
3544 }
3545 }
3546
3547 // Verify default methods
3548 if (default_methods() != NULL) {
3549 Array<Method*>* methods = this->default_methods();
3550 for (int j = 0; j < methods->length(); j++) {
3551 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3552 }
3553 for (int j = 0; j < methods->length() - 1; j++) {
3554 Method* m1 = methods->at(j);
3555 Method* m2 = methods->at(j + 1);
3556 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3557 }
3558 }
3559
3560 // Verify JNI static field identifiers
3561 if (jni_ids() != NULL) {
3562 jni_ids()->verify(this);
3563 }
3564
3565 // Verify other fields
3566 if (array_klasses() != NULL) {
3567 guarantee(array_klasses()->is_klass(), "should be klass");
3568 }
3569 if (constants() != NULL) {
3570 guarantee(constants()->is_constantPool(), "should be constant pool");
3571 }
3572 const Klass* host = host_klass();
3573 if (host != NULL) {
3574 guarantee(host->is_klass(), "should be klass");
3575 }
3576 }
3577
3578 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3579 Klass::oop_verify_on(obj, st);
3580 VerifyFieldClosure blk;
3581 obj->oop_iterate_no_header(&blk);
3582 }
3583
3584
3585 // JNIid class for jfieldIDs only
3586 // Note to reviewers:
3587 // These JNI functions are just moved over to column 1 and not changed
3588 // in the compressed oops workspace.
3589 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3590 _holder = holder;
3591 _offset = offset;
3592 _next = next;
3593 debug_only(_is_static_field_id = false;)
3594 }
3595
3596
3597 JNIid* JNIid::find(int offset) {
3598 JNIid* current = this;
3599 while (current != NULL) {
3600 if (current->offset() == offset) return current;
3601 current = current->next();
3602 }
3603 return NULL;
3604 }
3605
3606 void JNIid::deallocate(JNIid* current) {
3607 while (current != NULL) {
3608 JNIid* next = current->next();
3609 delete current;
3610 current = next;
3611 }
3612 }
3613
3614
3615 void JNIid::verify(Klass* holder) {
3616 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3617 int end_field_offset;
3618 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3619
3620 JNIid* current = this;
3621 while (current != NULL) {
3622 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3623 #ifdef ASSERT
3624 int o = current->offset();
3625 if (current->is_static_field_id()) {
3626 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3627 }
3628 #endif
3629 current = current->next();
3630 }
3631 }
3632
3633
3634 #ifdef ASSERT
3635 void InstanceKlass::set_init_state(ClassState state) {
3636 bool good_state = is_shared() ? (_init_state <= state)
3637 : (_init_state < state);
3638 assert(good_state || state == allocated, "illegal state transition");
3639 _init_state = (u1)state;
3640 }
3641 #endif
3642
3643 #if INCLUDE_JVMTI
3644
3645 // RedefineClasses() support for previous versions
3646
3647 // Globally, there is at least one previous version of a class to walk
3648 // during class unloading, which is saved because old methods in the class
3649 // are still running. Otherwise the previous version list is cleaned up.
3650 bool InstanceKlass::_has_previous_versions = false;
3651
3652 // Returns true if there are previous versions of a class for class
3653 // unloading only. Also resets the flag to false. purge_previous_version
3654 // will set the flag to true if there are any left, i.e., if there's any
3655 // work to do for next time. This is to avoid the expensive code cache
3656 // walk in CLDG::do_unloading().
3657 bool InstanceKlass::has_previous_versions_and_reset() {
3658 bool ret = _has_previous_versions;
3659 log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3660 ret ? "true" : "false");
3661 _has_previous_versions = false;
3662 return ret;
3663 }
3664
3665 // Purge previous versions before adding new previous versions of the class and
3666 // during class unloading.
3667 void InstanceKlass::purge_previous_version_list() {
3668 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3669 assert(has_been_redefined(), "Should only be called for main class");
3670
3671 // Quick exit.
3672 if (previous_versions() == NULL) {
3673 return;
3674 }
3675
3676 // This klass has previous versions so see what we can cleanup
3677 // while it is safe to do so.
3678
3679 int deleted_count = 0; // leave debugging breadcrumbs
3680 int live_count = 0;
3681 ClassLoaderData* loader_data = class_loader_data();
3682 assert(loader_data != NULL, "should never be null");
3683
3684 ResourceMark rm;
3685 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3686
3687 // previous versions are linked together through the InstanceKlass
3688 InstanceKlass* pv_node = previous_versions();
3689 InstanceKlass* last = this;
3690 int version = 0;
3691
3692 // check the previous versions list
3693 for (; pv_node != NULL; ) {
3694
3695 ConstantPool* pvcp = pv_node->constants();
3696 assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3697
3698 if (!pvcp->on_stack()) {
3699 // If the constant pool isn't on stack, none of the methods
3700 // are executing. Unlink this previous_version.
3701 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3702 // so will be deallocated during the next phase of class unloading.
3703 log_trace(redefine, class, iklass, purge)
3704 ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3705 // For debugging purposes.
3706 pv_node->set_is_scratch_class();
3707 // Unlink from previous version list.
3708 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3709 InstanceKlass* next = pv_node->previous_versions();
3710 pv_node->link_previous_versions(NULL); // point next to NULL
3711 last->link_previous_versions(next);
3712 // Add to the deallocate list after unlinking
3713 loader_data->add_to_deallocate_list(pv_node);
3714 pv_node = next;
3715 deleted_count++;
3716 version++;
3717 continue;
3718 } else {
3719 log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3720 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3721 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3722 live_count++;
3723 // found a previous version for next time we do class unloading
3724 _has_previous_versions = true;
3725 }
3726
3727 // At least one method is live in this previous version.
3728 // Reset dead EMCP methods not to get breakpoints.
3729 // All methods are deallocated when all of the methods for this class are no
3730 // longer running.
3731 Array<Method*>* method_refs = pv_node->methods();
3732 if (method_refs != NULL) {
3733 log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3734 for (int j = 0; j < method_refs->length(); j++) {
3735 Method* method = method_refs->at(j);
3736
3737 if (!method->on_stack()) {
3738 // no breakpoints for non-running methods
3739 if (method->is_running_emcp()) {
3740 method->set_running_emcp(false);
3741 }
3742 } else {
3743 assert (method->is_obsolete() || method->is_running_emcp(),
3744 "emcp method cannot run after emcp bit is cleared");
3745 log_trace(redefine, class, iklass, purge)
3746 ("purge: %s(%s): prev method @%d in version @%d is alive",
3747 method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3748 }
3749 }
3750 }
3751 // next previous version
3752 last = pv_node;
3753 pv_node = pv_node->previous_versions();
3754 version++;
3755 }
3756 log_trace(redefine, class, iklass, purge)
3757 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3758 }
3759
3760 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3761 int emcp_method_count) {
3762 int obsolete_method_count = old_methods->length() - emcp_method_count;
3763
3764 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3765 _previous_versions != NULL) {
3766 // We have a mix of obsolete and EMCP methods so we have to
3767 // clear out any matching EMCP method entries the hard way.
3768 int local_count = 0;
3769 for (int i = 0; i < old_methods->length(); i++) {
3770 Method* old_method = old_methods->at(i);
3771 if (old_method->is_obsolete()) {
3772 // only obsolete methods are interesting
3773 Symbol* m_name = old_method->name();
3774 Symbol* m_signature = old_method->signature();
3775
3776 // previous versions are linked together through the InstanceKlass
3777 int j = 0;
3778 for (InstanceKlass* prev_version = _previous_versions;
3779 prev_version != NULL;
3780 prev_version = prev_version->previous_versions(), j++) {
3781
3782 Array<Method*>* method_refs = prev_version->methods();
3783 for (int k = 0; k < method_refs->length(); k++) {
3784 Method* method = method_refs->at(k);
3785
3786 if (!method->is_obsolete() &&
3787 method->name() == m_name &&
3788 method->signature() == m_signature) {
3789 // The current RedefineClasses() call has made all EMCP
3790 // versions of this method obsolete so mark it as obsolete
3791 log_trace(redefine, class, iklass, add)
3792 ("%s(%s): flush obsolete method @%d in version @%d",
3793 m_name->as_C_string(), m_signature->as_C_string(), k, j);
3794
3795 method->set_is_obsolete();
3796 break;
3797 }
3798 }
3799
3800 // The previous loop may not find a matching EMCP method, but
3801 // that doesn't mean that we can optimize and not go any
3802 // further back in the PreviousVersion generations. The EMCP
3803 // method for this generation could have already been made obsolete,
3804 // but there still may be an older EMCP method that has not
3805 // been made obsolete.
3806 }
3807
3808 if (++local_count >= obsolete_method_count) {
3809 // no more obsolete methods so bail out now
3810 break;
3811 }
3812 }
3813 }
3814 }
3815 }
3816
3817 // Save the scratch_class as the previous version if any of the methods are running.
3818 // The previous_versions are used to set breakpoints in EMCP methods and they are
3819 // also used to clean MethodData links to redefined methods that are no longer running.
3820 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3821 int emcp_method_count) {
3822 assert(Thread::current()->is_VM_thread(),
3823 "only VMThread can add previous versions");
3824
3825 ResourceMark rm;
3826 log_trace(redefine, class, iklass, add)
3827 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3828
3829 // Clean out old previous versions for this class
3830 purge_previous_version_list();
3831
3832 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
3833 // a previous redefinition may be made obsolete by this redefinition.
3834 Array<Method*>* old_methods = scratch_class->methods();
3835 mark_newly_obsolete_methods(old_methods, emcp_method_count);
3836
3837 // If the constant pool for this previous version of the class
3838 // is not marked as being on the stack, then none of the methods
3839 // in this previous version of the class are on the stack so
3840 // we don't need to add this as a previous version.
3841 ConstantPool* cp_ref = scratch_class->constants();
3842 if (!cp_ref->on_stack()) {
3843 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3844 // For debugging purposes.
3845 scratch_class->set_is_scratch_class();
3846 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3847 return;
3848 }
3849
3850 if (emcp_method_count != 0) {
3851 // At least one method is still running, check for EMCP methods
3852 for (int i = 0; i < old_methods->length(); i++) {
3853 Method* old_method = old_methods->at(i);
3854 if (!old_method->is_obsolete() && old_method->on_stack()) {
3855 // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3856 // we can add breakpoints for it.
3857
3858 // We set the method->on_stack bit during safepoints for class redefinition
3859 // and use this bit to set the is_running_emcp bit.
3860 // After the safepoint, the on_stack bit is cleared and the running emcp
3861 // method may exit. If so, we would set a breakpoint in a method that
3862 // is never reached, but this won't be noticeable to the programmer.
3863 old_method->set_running_emcp(true);
3864 log_trace(redefine, class, iklass, add)
3865 ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3866 } else if (!old_method->is_obsolete()) {
3867 log_trace(redefine, class, iklass, add)
3868 ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3869 }
3870 }
3871 }
3872
3873 // Add previous version if any methods are still running.
3874 // Set has_previous_version flag for processing during class unloading.
3875 _has_previous_versions = true;
3876 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3877 assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3878 scratch_class->link_previous_versions(previous_versions());
3879 link_previous_versions(scratch_class);
3880 } // end add_previous_version()
3881
3882 #endif // INCLUDE_JVMTI
3883
3884 Method* InstanceKlass::method_with_idnum(int idnum) {
3885 Method* m = NULL;
3886 if (idnum < methods()->length()) {
3887 m = methods()->at(idnum);
3888 }
3889 if (m == NULL || m->method_idnum() != idnum) {
3890 for (int index = 0; index < methods()->length(); ++index) {
3891 m = methods()->at(index);
3892 if (m->method_idnum() == idnum) {
3893 return m;
3894 }
3895 }
3896 // None found, return null for the caller to handle.
3897 return NULL;
3898 }
3899 return m;
3900 }
3901
3902
3903 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3904 if (idnum >= methods()->length()) {
3905 return NULL;
3906 }
3907 Method* m = methods()->at(idnum);
3908 if (m != NULL && m->orig_method_idnum() == idnum) {
3909 return m;
3910 }
3911 // Obsolete method idnum does not match the original idnum
3912 for (int index = 0; index < methods()->length(); ++index) {
3913 m = methods()->at(index);
3914 if (m->orig_method_idnum() == idnum) {
3915 return m;
3916 }
3917 }
3918 // None found, return null for the caller to handle.
3919 return NULL;
3920 }
3921
3922
3923 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3924 InstanceKlass* holder = get_klass_version(version);
3925 if (holder == NULL) {
3926 return NULL; // The version of klass is gone, no method is found
3927 }
3928 Method* method = holder->method_with_orig_idnum(idnum);
3929 return method;
3930 }
3931
3932 #if INCLUDE_JVMTI
3933 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
3934 if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
3935 // Ignore the archived class stream data
3936 return NULL;
3937 } else {
3938 return _cached_class_file;
3939 }
3940 }
3941
3942 jint InstanceKlass::get_cached_class_file_len() {
3943 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3944 }
3945
3946 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3947 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3948 }
3949
3950 #if INCLUDE_CDS
3951 JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() {
3952 if (DumpSharedSpaces) {
3953 return _cached_class_file;
3954 } else {
3955 assert(this->is_shared(), "class should be shared");
3956 if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
3957 return _cached_class_file;
3958 } else {
3959 return NULL;
3960 }
3961 }
3962 }
3963 #endif
3964 #endif