1 /*
2 * Copyright (c) 1997, 2018, 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/classLoaderData.inline.hpp"
32 #include "classfile/javaClasses.hpp"
33 #include "classfile/moduleEntry.hpp"
34 #include "classfile/systemDictionary.hpp"
35 #include "classfile/systemDictionaryShared.hpp"
36 #include "classfile/verifier.hpp"
37 #include "classfile/vmSymbols.hpp"
38 #include "code/dependencyContext.hpp"
39 #include "compiler/compileBroker.hpp"
40 #include "gc/shared/collectedHeap.inline.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/allocation.inline.hpp"
48 #include "memory/heapInspection.hpp"
49 #include "memory/iterator.inline.hpp"
50 #include "memory/metadataFactory.hpp"
51 #include "memory/metaspaceClosure.hpp"
52 #include "memory/metaspaceShared.hpp"
53 #include "memory/oopFactory.hpp"
54 #include "memory/resourceArea.hpp"
55 #include "oops/fieldStreams.hpp"
56 #include "oops/instanceClassLoaderKlass.hpp"
57 #include "oops/instanceKlass.inline.hpp"
58 #include "oops/instanceMirrorKlass.hpp"
59 #include "oops/instanceOop.hpp"
60 #include "oops/klass.inline.hpp"
61 #include "oops/method.hpp"
62 #include "oops/oop.inline.hpp"
63 #include "oops/symbol.hpp"
64 #include "prims/jvmtiExport.hpp"
65 #include "prims/jvmtiRedefineClasses.hpp"
66 #include "prims/jvmtiThreadState.hpp"
67 #include "prims/methodComparator.hpp"
68 #include "runtime/atomic.hpp"
69 #include "runtime/fieldDescriptor.hpp"
70 #include "runtime/handles.inline.hpp"
71 #include "runtime/javaCalls.hpp"
72 #include "runtime/mutexLocker.hpp"
73 #include "runtime/orderAccess.hpp"
74 #include "runtime/thread.inline.hpp"
75 #include "services/classLoadingService.hpp"
76 #include "services/threadService.hpp"
77 #include "utilities/dtrace.hpp"
78 #include "utilities/macros.hpp"
79 #include "utilities/stringUtils.hpp"
80 #ifdef COMPILER1
81 #include "c1/c1_Compiler.hpp"
82 #endif
83
84 #ifdef DTRACE_ENABLED
85
86
87 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
88 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
89 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
90 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
91 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
92 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
93 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
94 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
95 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
96 { \
97 char* data = NULL; \
98 int len = 0; \
99 Symbol* clss_name = name(); \
100 if (clss_name != NULL) { \
101 data = (char*)clss_name->bytes(); \
102 len = clss_name->utf8_length(); \
103 } \
104 HOTSPOT_CLASS_INITIALIZATION_##type( \
105 data, len, (void*)class_loader(), thread_type); \
106 }
107
108 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
109 { \
110 char* data = NULL; \
111 int len = 0; \
112 Symbol* clss_name = name(); \
113 if (clss_name != NULL) { \
114 data = (char*)clss_name->bytes(); \
115 len = clss_name->utf8_length(); \
116 } \
117 HOTSPOT_CLASS_INITIALIZATION_##type( \
118 data, len, (void*)class_loader(), thread_type, wait); \
119 }
120
121 #else // ndef DTRACE_ENABLED
122
123 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
124 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
125
126 #endif // ndef DTRACE_ENABLED
127
128 static inline bool is_class_loader(const Symbol* class_name,
129 const ClassFileParser& parser) {
130 assert(class_name != NULL, "invariant");
131
132 if (class_name == vmSymbols::java_lang_ClassLoader()) {
133 return true;
134 }
135
136 if (SystemDictionary::ClassLoader_klass_loaded()) {
137 const Klass* const super_klass = parser.super_klass();
138 if (super_klass != NULL) {
139 if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
140 return true;
141 }
142 }
143 }
144 return false;
145 }
146
147 // called to verify that k is a member of this nest
148 bool InstanceKlass::has_nest_member(InstanceKlass* k, TRAPS) const {
149 if (_nest_members == NULL || _nest_members == Universe::the_empty_short_array()) {
150 if (log_is_enabled(Trace, class, nestmates)) {
151 ResourceMark rm(THREAD);
152 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
153 k->external_name(), this->external_name());
154 }
155 return false;
156 }
157
158 if (log_is_enabled(Trace, class, nestmates)) {
159 ResourceMark rm(THREAD);
160 log_trace(class, nestmates)("Checking nest membership of %s in %s",
161 k->external_name(), this->external_name());
162 }
163
164 // Check names first and if they match then check actual klass. This avoids
165 // resolving anything unnecessarily.
166 for (int i = 0; i < _nest_members->length(); i++) {
167 int cp_index = _nest_members->at(i);
168 Symbol* name = _constants->klass_name_at(cp_index);
169 if (name == k->name()) {
170 log_trace(class, nestmates)("- Found it at nest_members[%d] => cp[%d]", i, cp_index);
171
172 // names match so check actual klass - this may trigger class loading if
173 // it doesn't match (but that should be impossible)
174 Klass* k2 = _constants->klass_at(cp_index, CHECK_false);
175 if (k2 == k) {
176 log_trace(class, nestmates)("- class is listed as a nest member");
177 return true;
178 } else {
179 // same name but different klass!
180 log_trace(class, nestmates)(" - klass comparison failed!");
181 // can't have different classes for the same name, so we're done
182 return false;
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 // All other exceptions pass through (OOME, StackOverflowError, LinkageErrors 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 bool is_member = nest_host_k->has_nest_member(this, CHECK_NULL);
254 if (is_member) {
255 // save resolved nest-host value
256 _nest_host = nest_host_k;
257
258 if (log_is_enabled(Trace, class, nestmates)) {
259 ResourceMark rm(THREAD);
260 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
261 this->external_name(), k->external_name());
262 }
263 return nest_host_k;
264 }
265 }
266 error = "current type is not listed as a nest member";
267 } else {
268 error = "types are in different packages";
269 }
270
271 if (log_is_enabled(Trace, class, nestmates)) {
272 ResourceMark rm(THREAD);
273 log_trace(class, nestmates)("Type %s is not a nest member of resolved type %s: %s",
274 this->external_name(),
275 k->external_name(),
276 error);
277 }
278
279 if (validationException != NULL) {
280 ResourceMark rm(THREAD);
281 Exceptions::fthrow(THREAD_AND_LOCATION,
282 validationException,
283 "Type %s is not a nest member of %s: %s",
284 this->external_name(),
285 k->external_name(),
286 error
287 );
288 }
289 return NULL;
290 } else {
291 if (log_is_enabled(Trace, class, nestmates)) {
292 ResourceMark rm(THREAD);
293 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
294 this->external_name());
295 }
296 // save resolved nest-host value
297 return (_nest_host = this);
298 }
299 }
300 return nest_host_k;
301 }
302
303 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
304 // or we are k's nest_host - all of which is covered by comparing the two
305 // resolved_nest_hosts
306 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
307
308 assert(this != k, "this should be handled by higher-level code");
309
310 // Per JVMS 5.4.4 we first resolve and validate the current class, then
311 // the target class k. Resolution exceptions will be passed on by upper
312 // layers. IncompatibleClassChangeErrors from membership validation failures
313 // will also be passed through.
314
315 Symbol* icce = vmSymbols::java_lang_IncompatibleClassChangeError();
316 InstanceKlass* cur_host = nest_host(icce, CHECK_false);
317 if (cur_host == NULL) {
318 return false;
319 }
320
321 Klass* k_nest_host = k->nest_host(icce, CHECK_false);
322 if (k_nest_host == NULL) {
323 return false;
324 }
325
326 bool access = (cur_host == k_nest_host);
327
328 if (log_is_enabled(Trace, class, nestmates)) {
329 ResourceMark rm(THREAD);
330 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
331 this->external_name(),
332 access ? "" : "NOT ",
333 k->external_name());
334 }
335
336 return access;
337 }
338
339 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
340 const int size = InstanceKlass::size(parser.vtable_size(),
341 parser.itable_size(),
342 nonstatic_oop_map_size(parser.total_oop_map_count()),
343 parser.is_interface(),
344 parser.is_anonymous(),
345 should_store_fingerprint(parser.is_anonymous()));
346
347 const Symbol* const class_name = parser.class_name();
348 assert(class_name != NULL, "invariant");
349 ClassLoaderData* loader_data = parser.loader_data();
350 assert(loader_data != NULL, "invariant");
351
352 InstanceKlass* ik;
353
354 // Allocation
355 if (REF_NONE == parser.reference_type()) {
356 if (class_name == vmSymbols::java_lang_Class()) {
357 // mirror
358 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
359 }
360 else if (is_class_loader(class_name, parser)) {
361 // class loader
362 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
363 } else {
364 // normal
365 ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
366 }
367 } else {
368 // reference
369 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
370 }
371
372 // Check for pending exception before adding to the loader data and incrementing
373 // class count. Can get OOM here.
374 if (HAS_PENDING_EXCEPTION) {
375 return NULL;
376 }
377
378 return ik;
379 }
380
381
382 // copy method ordering from resource area to Metaspace
383 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
384 if (m != NULL) {
385 // allocate a new array and copy contents (memcpy?)
386 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
387 for (int i = 0; i < m->length(); i++) {
388 _method_ordering->at_put(i, m->at(i));
389 }
390 } else {
391 _method_ordering = Universe::the_empty_int_array();
392 }
393 }
394
395 // create a new array of vtable_indices for default methods
396 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
397 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
398 assert(default_vtable_indices() == NULL, "only create once");
399 set_default_vtable_indices(vtable_indices);
400 return vtable_indices;
401 }
402
403 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind, KlassID id) :
404 Klass(id),
405 _static_field_size(parser.static_field_size()),
406 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
407 _itable_len(parser.itable_size()),
408 _reference_type(parser.reference_type()),
409 _nest_members(NULL),
410 _nest_host_index(0),
411 _nest_host(NULL) {
412 set_vtable_length(parser.vtable_size());
413 set_kind(kind);
414 set_access_flags(parser.access_flags());
415 set_is_anonymous(parser.is_anonymous());
416 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
417 false));
418
419 assert(NULL == _methods, "underlying memory not zeroed?");
420 assert(is_instance_klass(), "is layout incorrect?");
421 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
422 }
423
424 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
425 Array<Method*>* methods) {
426 if (methods != NULL && methods != Universe::the_empty_method_array() &&
427 !methods->is_shared()) {
428 for (int i = 0; i < methods->length(); i++) {
429 Method* method = methods->at(i);
430 if (method == NULL) continue; // maybe null if error processing
431 // Only want to delete methods that are not executing for RedefineClasses.
432 // The previous version will point to them so they're not totally dangling
433 assert (!method->on_stack(), "shouldn't be called with methods on stack");
434 MetadataFactory::free_metadata(loader_data, method);
435 }
436 MetadataFactory::free_array<Method*>(loader_data, methods);
437 }
438 }
439
440 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
441 const Klass* super_klass,
442 Array<Klass*>* local_interfaces,
443 Array<Klass*>* transitive_interfaces) {
444 // Only deallocate transitive interfaces if not empty, same as super class
445 // or same as local interfaces. See code in parseClassFile.
446 Array<Klass*>* ti = transitive_interfaces;
447 if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
448 // check that the interfaces don't come from super class
449 Array<Klass*>* sti = (super_klass == NULL) ? NULL :
450 InstanceKlass::cast(super_klass)->transitive_interfaces();
451 if (ti != sti && ti != NULL && !ti->is_shared()) {
452 MetadataFactory::free_array<Klass*>(loader_data, ti);
453 }
454 }
455
456 // local interfaces can be empty
457 if (local_interfaces != Universe::the_empty_klass_array() &&
458 local_interfaces != NULL && !local_interfaces->is_shared()) {
459 MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
460 }
461 }
462
463 // This function deallocates the metadata and C heap pointers that the
464 // InstanceKlass points to.
465 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
466
467 // Orphan the mirror first, CMS thinks it's still live.
468 if (java_mirror() != NULL) {
469 java_lang_Class::set_klass(java_mirror(), NULL);
470 }
471
472 // Also remove mirror from handles
473 loader_data->remove_handle(_java_mirror);
474
475 // Need to take this class off the class loader data list.
476 loader_data->remove_class(this);
477
478 // The array_klass for this class is created later, after error handling.
479 // For class redefinition, we keep the original class so this scratch class
480 // doesn't have an array class. Either way, assert that there is nothing
481 // to deallocate.
482 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
483
484 // Release C heap allocated data that this might point to, which includes
485 // reference counting symbol names.
486 release_C_heap_structures();
487
488 deallocate_methods(loader_data, methods());
489 set_methods(NULL);
490
491 if (method_ordering() != NULL &&
492 method_ordering() != Universe::the_empty_int_array() &&
493 !method_ordering()->is_shared()) {
494 MetadataFactory::free_array<int>(loader_data, method_ordering());
495 }
496 set_method_ordering(NULL);
497
498 // default methods can be empty
499 if (default_methods() != NULL &&
500 default_methods() != Universe::the_empty_method_array() &&
501 !default_methods()->is_shared()) {
502 MetadataFactory::free_array<Method*>(loader_data, default_methods());
503 }
504 // Do NOT deallocate the default methods, they are owned by superinterfaces.
505 set_default_methods(NULL);
506
507 // default methods vtable indices can be empty
508 if (default_vtable_indices() != NULL &&
509 !default_vtable_indices()->is_shared()) {
510 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
511 }
512 set_default_vtable_indices(NULL);
513
514
515 // This array is in Klass, but remove it with the InstanceKlass since
516 // this place would be the only caller and it can share memory with transitive
517 // interfaces.
518 if (secondary_supers() != NULL &&
519 secondary_supers() != Universe::the_empty_klass_array() &&
520 secondary_supers() != transitive_interfaces() &&
521 !secondary_supers()->is_shared()) {
522 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
523 }
524 set_secondary_supers(NULL);
525
526 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
527 set_transitive_interfaces(NULL);
528 set_local_interfaces(NULL);
529
530 if (fields() != NULL && !fields()->is_shared()) {
531 MetadataFactory::free_array<jushort>(loader_data, fields());
532 }
533 set_fields(NULL, 0);
534
535 // If a method from a redefined class is using this constant pool, don't
536 // delete it, yet. The new class's previous version will point to this.
537 if (constants() != NULL) {
538 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
539 if (!constants()->is_shared()) {
540 MetadataFactory::free_metadata(loader_data, constants());
541 }
542 // Delete any cached resolution errors for the constant pool
543 SystemDictionary::delete_resolution_error(constants());
544
545 set_constants(NULL);
546 }
547
548 if (inner_classes() != NULL &&
549 inner_classes() != Universe::the_empty_short_array() &&
550 !inner_classes()->is_shared()) {
551 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
552 }
553 set_inner_classes(NULL);
554
555 if (nest_members() != NULL &&
556 nest_members() != Universe::the_empty_short_array() &&
557 !nest_members()->is_shared()) {
558 MetadataFactory::free_array<jushort>(loader_data, nest_members());
559 }
560 set_nest_members(NULL);
561
562 // We should deallocate the Annotations instance if it's not in shared spaces.
563 if (annotations() != NULL && !annotations()->is_shared()) {
564 MetadataFactory::free_metadata(loader_data, annotations());
565 }
566 set_annotations(NULL);
567 }
568
569 bool InstanceKlass::should_be_initialized() const {
570 return !is_initialized();
571 }
572
573 klassItable InstanceKlass::itable() const {
574 return klassItable(const_cast<InstanceKlass*>(this));
575 }
576
577 void InstanceKlass::eager_initialize(Thread *thread) {
578 if (!EagerInitialization) return;
579
580 if (this->is_not_initialized()) {
581 // abort if the the class has a class initializer
582 if (this->class_initializer() != NULL) return;
583
584 // abort if it is java.lang.Object (initialization is handled in genesis)
585 Klass* super_klass = super();
586 if (super_klass == NULL) return;
587
588 // abort if the super class should be initialized
589 if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
590
591 // call body to expose the this pointer
592 eager_initialize_impl();
593 }
594 }
595
596 // JVMTI spec thinks there are signers and protection domain in the
597 // instanceKlass. These accessors pretend these fields are there.
598 // The hprof specification also thinks these fields are in InstanceKlass.
599 oop InstanceKlass::protection_domain() const {
600 // return the protection_domain from the mirror
601 return java_lang_Class::protection_domain(java_mirror());
602 }
603
604 // To remove these from requires an incompatible change and CCC request.
605 objArrayOop InstanceKlass::signers() const {
606 // return the signers from the mirror
607 return java_lang_Class::signers(java_mirror());
608 }
609
610 oop InstanceKlass::init_lock() const {
611 // return the init lock from the mirror
612 oop lock = java_lang_Class::init_lock(java_mirror());
613 // Prevent reordering with any access of initialization state
614 OrderAccess::loadload();
615 assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
616 "only fully initialized state can have a null lock");
617 return lock;
618 }
619
620 // Set the initialization lock to null so the object can be GC'ed. Any racing
621 // threads to get this lock will see a null lock and will not lock.
622 // That's okay because they all check for initialized state after getting
623 // the lock and return.
624 void InstanceKlass::fence_and_clear_init_lock() {
625 // make sure previous stores are all done, notably the init_state.
626 OrderAccess::storestore();
627 java_lang_Class::set_init_lock(java_mirror(), NULL);
628 assert(!is_not_initialized(), "class must be initialized now");
629 }
630
631 void InstanceKlass::eager_initialize_impl() {
632 EXCEPTION_MARK;
633 HandleMark hm(THREAD);
634 Handle h_init_lock(THREAD, init_lock());
635 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
636
637 // abort if someone beat us to the initialization
638 if (!is_not_initialized()) return; // note: not equivalent to is_initialized()
639
640 ClassState old_state = init_state();
641 link_class_impl(true, THREAD);
642 if (HAS_PENDING_EXCEPTION) {
643 CLEAR_PENDING_EXCEPTION;
644 // Abort if linking the class throws an exception.
645
646 // Use a test to avoid redundantly resetting the state if there's
647 // no change. Set_init_state() asserts that state changes make
648 // progress, whereas here we might just be spinning in place.
649 if (old_state != _init_state)
650 set_init_state(old_state);
651 } else {
652 // linking successfull, mark class as initialized
653 set_init_state(fully_initialized);
654 fence_and_clear_init_lock();
655 // trace
656 if (log_is_enabled(Info, class, init)) {
657 ResourceMark rm(THREAD);
658 log_info(class, init)("[Initialized %s without side effects]", external_name());
659 }
660 }
661 }
662
663
664 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
665 // process. The step comments refers to the procedure described in that section.
666 // Note: implementation moved to static method to expose the this pointer.
667 void InstanceKlass::initialize(TRAPS) {
668 if (this->should_be_initialized()) {
669 initialize_impl(CHECK);
670 // Note: at this point the class may be initialized
671 // OR it may be in the state of being initialized
672 // in case of recursive initialization!
673 } else {
674 assert(is_initialized(), "sanity check");
675 }
676 }
677
678
679 bool InstanceKlass::verify_code(bool throw_verifyerror, TRAPS) {
680 // 1) Verify the bytecodes
681 Verifier::Mode mode =
682 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
683 return Verifier::verify(this, mode, should_verify_class(), THREAD);
684 }
685
686
687 // Used exclusively by the shared spaces dump mechanism to prevent
688 // classes mapped into the shared regions in new VMs from appearing linked.
689
690 void InstanceKlass::unlink_class() {
691 assert(is_linked(), "must be linked");
692 _init_state = loaded;
693 }
694
695 void InstanceKlass::link_class(TRAPS) {
696 assert(is_loaded(), "must be loaded");
697 if (!is_linked()) {
698 link_class_impl(true, CHECK);
699 }
700 }
701
702 // Called to verify that a class can link during initialization, without
703 // throwing a VerifyError.
704 bool InstanceKlass::link_class_or_fail(TRAPS) {
705 assert(is_loaded(), "must be loaded");
706 if (!is_linked()) {
707 link_class_impl(false, CHECK_false);
708 }
709 return is_linked();
710 }
711
712 bool InstanceKlass::link_class_impl(bool throw_verifyerror, TRAPS) {
713 if (DumpSharedSpaces && is_in_error_state()) {
714 // This is for CDS dumping phase only -- we use the in_error_state to indicate that
715 // the class has failed verification. Throwing the NoClassDefFoundError here is just
716 // a convenient way to stop repeat attempts to verify the same (bad) class.
717 //
718 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
719 // if we are executing Java code. This is not a problem for CDS dumping phase since
720 // it doesn't execute any Java code.
721 ResourceMark rm(THREAD);
722 Exceptions::fthrow(THREAD_AND_LOCATION,
723 vmSymbols::java_lang_NoClassDefFoundError(),
724 "Class %s, or one of its supertypes, failed class initialization",
725 external_name());
726 return false;
727 }
728 // return if already verified
729 if (is_linked()) {
730 return true;
731 }
732
733 // Timing
734 // timer handles recursion
735 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
736 JavaThread* jt = (JavaThread*)THREAD;
737
738 // link super class before linking this class
739 Klass* super_klass = super();
740 if (super_klass != NULL) {
741 if (super_klass->is_interface()) { // check if super class is an interface
742 ResourceMark rm(THREAD);
743 Exceptions::fthrow(
744 THREAD_AND_LOCATION,
745 vmSymbols::java_lang_IncompatibleClassChangeError(),
746 "class %s has interface %s as super class",
747 external_name(),
748 super_klass->external_name()
749 );
750 return false;
751 }
752
753 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
754 ik_super->link_class_impl(throw_verifyerror, CHECK_false);
755 }
756
757 // link all interfaces implemented by this class before linking this class
758 Array<Klass*>* interfaces = local_interfaces();
759 int num_interfaces = interfaces->length();
760 for (int index = 0; index < num_interfaces; index++) {
761 InstanceKlass* interk = InstanceKlass::cast(interfaces->at(index));
762 interk->link_class_impl(throw_verifyerror, CHECK_false);
763 }
764
765 // in case the class is linked in the process of linking its superclasses
766 if (is_linked()) {
767 return true;
768 }
769
770 // trace only the link time for this klass that includes
771 // the verification time
772 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
773 ClassLoader::perf_class_link_selftime(),
774 ClassLoader::perf_classes_linked(),
775 jt->get_thread_stat()->perf_recursion_counts_addr(),
776 jt->get_thread_stat()->perf_timers_addr(),
777 PerfClassTraceTime::CLASS_LINK);
778
779 // verification & rewriting
780 {
781 HandleMark hm(THREAD);
782 Handle h_init_lock(THREAD, init_lock());
783 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
784 // rewritten will have been set if loader constraint error found
785 // on an earlier link attempt
786 // don't verify or rewrite if already rewritten
787 //
788
789 if (!is_linked()) {
790 if (!is_rewritten()) {
791 {
792 bool verify_ok = verify_code(throw_verifyerror, THREAD);
793 if (!verify_ok) {
794 return false;
795 }
796 }
797
798 // Just in case a side-effect of verify linked this class already
799 // (which can sometimes happen since the verifier loads classes
800 // using custom class loaders, which are free to initialize things)
801 if (is_linked()) {
802 return true;
803 }
804
805 // also sets rewritten
806 rewrite_class(CHECK_false);
807 } else if (is_shared()) {
808 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
809 }
810
811 // relocate jsrs and link methods after they are all rewritten
812 link_methods(CHECK_false);
813
814 // Initialize the vtable and interface table after
815 // methods have been rewritten since rewrite may
816 // fabricate new Method*s.
817 // also does loader constraint checking
818 //
819 // initialize_vtable and initialize_itable need to be rerun for
820 // a shared class if the class is not loaded by the NULL classloader.
821 ClassLoaderData * loader_data = class_loader_data();
822 if (!(is_shared() &&
823 loader_data->is_the_null_class_loader_data())) {
824 ResourceMark rm(THREAD);
825 vtable().initialize_vtable(true, CHECK_false);
826 itable().initialize_itable(true, CHECK_false);
827 }
828 #ifdef ASSERT
829 else {
830 vtable().verify(tty, true);
831 // In case itable verification is ever added.
832 // itable().verify(tty, true);
833 }
834 #endif
835 set_init_state(linked);
836 if (JvmtiExport::should_post_class_prepare()) {
837 Thread *thread = THREAD;
838 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
839 JvmtiExport::post_class_prepare((JavaThread *) thread, this);
840 }
841 }
842 }
843 return true;
844 }
845
846 // Rewrite the byte codes of all of the methods of a class.
847 // The rewriter must be called exactly once. Rewriting must happen after
848 // verification but before the first method of the class is executed.
849 void InstanceKlass::rewrite_class(TRAPS) {
850 assert(is_loaded(), "must be loaded");
851 if (is_rewritten()) {
852 assert(is_shared(), "rewriting an unshared class?");
853 return;
854 }
855 Rewriter::rewrite(this, CHECK);
856 set_rewritten();
857 }
858
859 // Now relocate and link method entry points after class is rewritten.
860 // This is outside is_rewritten flag. In case of an exception, it can be
861 // executed more than once.
862 void InstanceKlass::link_methods(TRAPS) {
863 int len = methods()->length();
864 for (int i = len-1; i >= 0; i--) {
865 methodHandle m(THREAD, methods()->at(i));
866
867 // Set up method entry points for compiler and interpreter .
868 m->link_method(m, CHECK);
869 }
870 }
871
872 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
873 void InstanceKlass::initialize_super_interfaces(TRAPS) {
874 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
875 for (int i = 0; i < local_interfaces()->length(); ++i) {
876 Klass* iface = local_interfaces()->at(i);
877 InstanceKlass* ik = InstanceKlass::cast(iface);
878
879 // Initialization is depth first search ie. we start with top of the inheritance tree
880 // has_nonstatic_concrete_methods drives searching superinterfaces since it
881 // means has_nonstatic_concrete_methods in its superinterface hierarchy
882 if (ik->has_nonstatic_concrete_methods()) {
883 ik->initialize_super_interfaces(CHECK);
884 }
885
886 // Only initialize() interfaces that "declare" concrete methods.
887 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
888 ik->initialize(CHECK);
889 }
890 }
891 }
892
893 void InstanceKlass::initialize_impl(TRAPS) {
894 HandleMark hm(THREAD);
895
896 // Make sure klass is linked (verified) before initialization
897 // A class could already be verified, since it has been reflected upon.
898 link_class(CHECK);
899
900 DTRACE_CLASSINIT_PROBE(required, -1);
901
902 bool wait = false;
903
904 // refer to the JVM book page 47 for description of steps
905 // Step 1
906 {
907 Handle h_init_lock(THREAD, init_lock());
908 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
909
910 Thread *self = THREAD; // it's passed the current thread
911
912 // Step 2
913 // If we were to use wait() instead of waitInterruptibly() then
914 // we might end up throwing IE from link/symbol resolution sites
915 // that aren't expected to throw. This would wreak havoc. See 6320309.
916 while(is_being_initialized() && !is_reentrant_initialization(self)) {
917 wait = true;
918 ol.waitUninterruptibly(CHECK);
919 }
920
921 // Step 3
922 if (is_being_initialized() && is_reentrant_initialization(self)) {
923 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
924 return;
925 }
926
927 // Step 4
928 if (is_initialized()) {
929 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
930 return;
931 }
932
933 // Step 5
934 if (is_in_error_state()) {
935 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
936 ResourceMark rm(THREAD);
937 const char* desc = "Could not initialize class ";
938 const char* className = external_name();
939 size_t msglen = strlen(desc) + strlen(className) + 1;
940 char* message = NEW_RESOURCE_ARRAY(char, msglen);
941 if (NULL == message) {
942 // Out of memory: can't create detailed error message
943 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
944 } else {
945 jio_snprintf(message, msglen, "%s%s", desc, className);
946 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
947 }
948 }
949
950 // Step 6
951 set_init_state(being_initialized);
952 set_init_thread(self);
953 }
954
955 // Step 7
956 // Next, if C is a class rather than an interface, initialize it's super class and super
957 // interfaces.
958 if (!is_interface()) {
959 Klass* super_klass = super();
960 if (super_klass != NULL && super_klass->should_be_initialized()) {
961 super_klass->initialize(THREAD);
962 }
963 // If C implements any interface that declares a non-static, concrete method,
964 // the initialization of C triggers initialization of its super interfaces.
965 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
966 // having a superinterface that declares, non-static, concrete methods
967 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
968 initialize_super_interfaces(THREAD);
969 }
970
971 // If any exceptions, complete abruptly, throwing the same exception as above.
972 if (HAS_PENDING_EXCEPTION) {
973 Handle e(THREAD, PENDING_EXCEPTION);
974 CLEAR_PENDING_EXCEPTION;
975 {
976 EXCEPTION_MARK;
977 // Locks object, set state, and notify all waiting threads
978 set_initialization_state_and_notify(initialization_error, THREAD);
979 CLEAR_PENDING_EXCEPTION;
980 }
981 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
982 THROW_OOP(e());
983 }
984 }
985
986
987 // Look for aot compiled methods for this klass, including class initializer.
988 AOTLoader::load_for_klass(this, THREAD);
989
990 // Step 8
991 {
992 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
993 JavaThread* jt = (JavaThread*)THREAD;
994 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
995 // Timer includes any side effects of class initialization (resolution,
996 // etc), but not recursive entry into call_class_initializer().
997 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
998 ClassLoader::perf_class_init_selftime(),
999 ClassLoader::perf_classes_inited(),
1000 jt->get_thread_stat()->perf_recursion_counts_addr(),
1001 jt->get_thread_stat()->perf_timers_addr(),
1002 PerfClassTraceTime::CLASS_CLINIT);
1003 call_class_initializer(THREAD);
1004 }
1005
1006 // Step 9
1007 if (!HAS_PENDING_EXCEPTION) {
1008 set_initialization_state_and_notify(fully_initialized, CHECK);
1009 {
1010 debug_only(vtable().verify(tty, true);)
1011 }
1012 }
1013 else {
1014 // Step 10 and 11
1015 Handle e(THREAD, PENDING_EXCEPTION);
1016 CLEAR_PENDING_EXCEPTION;
1017 // JVMTI has already reported the pending exception
1018 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1019 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
1020 {
1021 EXCEPTION_MARK;
1022 set_initialization_state_and_notify(initialization_error, THREAD);
1023 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1024 // JVMTI has already reported the pending exception
1025 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1026 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
1027 }
1028 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1029 if (e->is_a(SystemDictionary::Error_klass())) {
1030 THROW_OOP(e());
1031 } else {
1032 JavaCallArguments args(e);
1033 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1034 vmSymbols::throwable_void_signature(),
1035 &args);
1036 }
1037 }
1038 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1039 }
1040
1041
1042 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1043 Handle h_init_lock(THREAD, init_lock());
1044 if (h_init_lock() != NULL) {
1045 ObjectLocker ol(h_init_lock, THREAD);
1046 set_init_state(state);
1047 fence_and_clear_init_lock();
1048 ol.notify_all(CHECK);
1049 } else {
1050 assert(h_init_lock() != NULL, "The initialization state should never be set twice");
1051 set_init_state(state);
1052 }
1053 }
1054
1055 // The embedded _implementor field can only record one implementor.
1056 // When there are more than one implementors, the _implementor field
1057 // is set to the interface Klass* itself. Following are the possible
1058 // values for the _implementor field:
1059 // NULL - no implementor
1060 // implementor Klass* - one implementor
1061 // self - more than one implementor
1062 //
1063 // The _implementor field only exists for interfaces.
1064 void InstanceKlass::add_implementor(Klass* k) {
1065 assert(Compile_lock->owned_by_self(), "");
1066 assert(is_interface(), "not interface");
1067 // Filter out my subinterfaces.
1068 // (Note: Interfaces are never on the subklass list.)
1069 if (InstanceKlass::cast(k)->is_interface()) return;
1070
1071 // Filter out subclasses whose supers already implement me.
1072 // (Note: CHA must walk subclasses of direct implementors
1073 // in order to locate indirect implementors.)
1074 Klass* sk = k->super();
1075 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
1076 // We only need to check one immediate superclass, since the
1077 // implements_interface query looks at transitive_interfaces.
1078 // Any supers of the super have the same (or fewer) transitive_interfaces.
1079 return;
1080
1081 Klass* ik = implementor();
1082 if (ik == NULL) {
1083 set_implementor(k);
1084 } else if (ik != this) {
1085 // There is already an implementor. Use itself as an indicator of
1086 // more than one implementors.
1087 set_implementor(this);
1088 }
1089
1090 // The implementor also implements the transitive_interfaces
1091 for (int index = 0; index < local_interfaces()->length(); index++) {
1092 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
1093 }
1094 }
1095
1096 void InstanceKlass::init_implementor() {
1097 if (is_interface()) {
1098 set_implementor(NULL);
1099 }
1100 }
1101
1102
1103 void InstanceKlass::process_interfaces(Thread *thread) {
1104 // link this class into the implementors list of every interface it implements
1105 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1106 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1107 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
1108 assert(interf->is_interface(), "expected interface");
1109 interf->add_implementor(this);
1110 }
1111 }
1112
1113 bool InstanceKlass::can_be_primary_super_slow() const {
1114 if (is_interface())
1115 return false;
1116 else
1117 return Klass::can_be_primary_super_slow();
1118 }
1119
1120 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1121 Array<Klass*>* transitive_interfaces) {
1122 // The secondaries are the implemented interfaces.
1123 Array<Klass*>* interfaces = transitive_interfaces;
1124 int num_secondaries = num_extra_slots + interfaces->length();
1125 if (num_secondaries == 0) {
1126 // Must share this for correct bootstrapping!
1127 set_secondary_supers(Universe::the_empty_klass_array());
1128 return NULL;
1129 } else if (num_extra_slots == 0) {
1130 // The secondary super list is exactly the same as the transitive interfaces.
1131 // Redefine classes has to be careful not to delete this!
1132 set_secondary_supers(interfaces);
1133 return NULL;
1134 } else {
1135 // Copy transitive interfaces to a temporary growable array to be constructed
1136 // into the secondary super list with extra slots.
1137 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1138 for (int i = 0; i < interfaces->length(); i++) {
1139 secondaries->push(interfaces->at(i));
1140 }
1141 return secondaries;
1142 }
1143 }
1144
1145 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
1146 if (k->is_interface()) {
1147 return implements_interface(k);
1148 } else {
1149 return Klass::compute_is_subtype_of(k);
1150 }
1151 }
1152
1153 bool InstanceKlass::implements_interface(Klass* k) const {
1154 if (this == k) return true;
1155 assert(k->is_interface(), "should be an interface class");
1156 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1157 if (transitive_interfaces()->at(i) == k) {
1158 return true;
1159 }
1160 }
1161 return false;
1162 }
1163
1164 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1165 // Verify direct super interface
1166 if (this == k) return true;
1167 assert(k->is_interface(), "should be an interface class");
1168 for (int i = 0; i < local_interfaces()->length(); i++) {
1169 if (local_interfaces()->at(i) == k) {
1170 return true;
1171 }
1172 }
1173 return false;
1174 }
1175
1176 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1177 if (length < 0) {
1178 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length));
1179 }
1180 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
1181 report_java_out_of_memory("Requested array size exceeds VM limit");
1182 JvmtiExport::post_array_size_exhausted();
1183 THROW_OOP_0(Universe::out_of_memory_error_array_size());
1184 }
1185 int size = objArrayOopDesc::object_size(length);
1186 Klass* ak = array_klass(n, CHECK_NULL);
1187 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1188 /* do_zero */ true, CHECK_NULL);
1189 return o;
1190 }
1191
1192 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1193 if (TraceFinalizerRegistration) {
1194 tty->print("Registered ");
1195 i->print_value_on(tty);
1196 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1197 }
1198 instanceHandle h_i(THREAD, i);
1199 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1200 JavaValue result(T_VOID);
1201 JavaCallArguments args(h_i);
1202 methodHandle mh (THREAD, Universe::finalizer_register_method());
1203 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1204 return h_i();
1205 }
1206
1207 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1208 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1209 int size = size_helper(); // Query before forming handle.
1210
1211 instanceOop i;
1212
1213 i = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1214 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1215 i = register_finalizer(i, CHECK_NULL);
1216 }
1217 return i;
1218 }
1219
1220 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1221 return instanceHandle(THREAD, allocate_instance(THREAD));
1222 }
1223
1224 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1225 if (is_interface() || is_abstract()) {
1226 ResourceMark rm(THREAD);
1227 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1228 : vmSymbols::java_lang_InstantiationException(), external_name());
1229 }
1230 if (this == SystemDictionary::Class_klass()) {
1231 ResourceMark rm(THREAD);
1232 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1233 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1234 }
1235 }
1236
1237 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1238 // Need load-acquire for lock-free read
1239 if (array_klasses_acquire() == NULL) {
1240 if (or_null) return NULL;
1241
1242 ResourceMark rm;
1243 JavaThread *jt = (JavaThread *)THREAD;
1244 {
1245 // Atomic creation of array_klasses
1246 MutexLocker mc(Compile_lock, THREAD); // for vtables
1247 MutexLocker ma(MultiArray_lock, THREAD);
1248
1249 // Check if update has already taken place
1250 if (array_klasses() == NULL) {
1251 Klass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1252 // use 'release' to pair with lock-free load
1253 release_set_array_klasses(k);
1254 }
1255 }
1256 }
1257 // _this will always be set at this point
1258 ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1259 if (or_null) {
1260 return oak->array_klass_or_null(n);
1261 }
1262 return oak->array_klass(n, THREAD);
1263 }
1264
1265 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1266 return array_klass_impl(or_null, 1, THREAD);
1267 }
1268
1269 static int call_class_initializer_counter = 0; // for debugging
1270
1271 Method* InstanceKlass::class_initializer() const {
1272 Method* clinit = find_method(
1273 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1274 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1275 return clinit;
1276 }
1277 return NULL;
1278 }
1279
1280 void InstanceKlass::call_class_initializer(TRAPS) {
1281 if (ReplayCompiles &&
1282 (ReplaySuppressInitializers == 1 ||
1283 (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1284 // Hide the existence of the initializer for the purpose of replaying the compile
1285 return;
1286 }
1287
1288 methodHandle h_method(THREAD, class_initializer());
1289 assert(!is_initialized(), "we cannot initialize twice");
1290 LogTarget(Info, class, init) lt;
1291 if (lt.is_enabled()) {
1292 ResourceMark rm;
1293 LogStream ls(lt);
1294 ls.print("%d Initializing ", call_class_initializer_counter++);
1295 name()->print_value_on(&ls);
1296 ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1297 }
1298 if (h_method() != NULL) {
1299 JavaCallArguments args; // No arguments
1300 JavaValue result(T_VOID);
1301 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1302 }
1303 }
1304
1305
1306 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1307 InterpreterOopMap* entry_for) {
1308 // Lazily create the _oop_map_cache at first request
1309 // Lock-free access requires load_acquire.
1310 OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache);
1311 if (oop_map_cache == NULL) {
1312 MutexLocker x(OopMapCacheAlloc_lock);
1313 // Check if _oop_map_cache was allocated while we were waiting for this lock
1314 if ((oop_map_cache = _oop_map_cache) == NULL) {
1315 oop_map_cache = new OopMapCache();
1316 // Ensure _oop_map_cache is stable, since it is examined without a lock
1317 OrderAccess::release_store(&_oop_map_cache, oop_map_cache);
1318 }
1319 }
1320 // _oop_map_cache is constant after init; lookup below does its own locking.
1321 oop_map_cache->lookup(method, bci, entry_for);
1322 }
1323
1324
1325 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1326 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1327 Symbol* f_name = fs.name();
1328 Symbol* f_sig = fs.signature();
1329 if (f_name == name && f_sig == sig) {
1330 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1331 return true;
1332 }
1333 }
1334 return false;
1335 }
1336
1337
1338 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1339 const int n = local_interfaces()->length();
1340 for (int i = 0; i < n; i++) {
1341 Klass* intf1 = local_interfaces()->at(i);
1342 assert(intf1->is_interface(), "just checking type");
1343 // search for field in current interface
1344 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1345 assert(fd->is_static(), "interface field must be static");
1346 return intf1;
1347 }
1348 // search for field in direct superinterfaces
1349 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1350 if (intf2 != NULL) return intf2;
1351 }
1352 // otherwise field lookup fails
1353 return NULL;
1354 }
1355
1356
1357 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1358 // search order according to newest JVM spec (5.4.3.2, p.167).
1359 // 1) search for field in current klass
1360 if (find_local_field(name, sig, fd)) {
1361 return const_cast<InstanceKlass*>(this);
1362 }
1363 // 2) search for field recursively in direct superinterfaces
1364 { Klass* intf = find_interface_field(name, sig, fd);
1365 if (intf != NULL) return intf;
1366 }
1367 // 3) apply field lookup recursively if superclass exists
1368 { Klass* supr = super();
1369 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1370 }
1371 // 4) otherwise field lookup fails
1372 return NULL;
1373 }
1374
1375
1376 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1377 // search order according to newest JVM spec (5.4.3.2, p.167).
1378 // 1) search for field in current klass
1379 if (find_local_field(name, sig, fd)) {
1380 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1381 }
1382 // 2) search for field recursively in direct superinterfaces
1383 if (is_static) {
1384 Klass* intf = find_interface_field(name, sig, fd);
1385 if (intf != NULL) return intf;
1386 }
1387 // 3) apply field lookup recursively if superclass exists
1388 { Klass* supr = super();
1389 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1390 }
1391 // 4) otherwise field lookup fails
1392 return NULL;
1393 }
1394
1395
1396 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1397 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1398 if (fs.offset() == offset) {
1399 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1400 if (fd->is_static() == is_static) return true;
1401 }
1402 }
1403 return false;
1404 }
1405
1406
1407 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1408 Klass* klass = const_cast<InstanceKlass*>(this);
1409 while (klass != NULL) {
1410 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1411 return true;
1412 }
1413 klass = klass->super();
1414 }
1415 return false;
1416 }
1417
1418
1419 void InstanceKlass::methods_do(void f(Method* method)) {
1420 // Methods aren't stable until they are loaded. This can be read outside
1421 // a lock through the ClassLoaderData for profiling
1422 if (!is_loaded()) {
1423 return;
1424 }
1425
1426 int len = methods()->length();
1427 for (int index = 0; index < len; index++) {
1428 Method* m = methods()->at(index);
1429 assert(m->is_method(), "must be method");
1430 f(m);
1431 }
1432 }
1433
1434
1435 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1436 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1437 if (fs.access_flags().is_static()) {
1438 fieldDescriptor& fd = fs.field_descriptor();
1439 cl->do_field(&fd);
1440 }
1441 }
1442 }
1443
1444
1445 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1446 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1447 if (fs.access_flags().is_static()) {
1448 fieldDescriptor& fd = fs.field_descriptor();
1449 f(&fd, mirror, CHECK);
1450 }
1451 }
1452 }
1453
1454
1455 static int compare_fields_by_offset(int* a, int* b) {
1456 return a[0] - b[0];
1457 }
1458
1459 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1460 InstanceKlass* super = superklass();
1461 if (super != NULL) {
1462 super->do_nonstatic_fields(cl);
1463 }
1464 fieldDescriptor fd;
1465 int length = java_fields_count();
1466 // In DebugInfo nonstatic fields are sorted by offset.
1467 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1468 int j = 0;
1469 for (int i = 0; i < length; i += 1) {
1470 fd.reinitialize(this, i);
1471 if (!fd.is_static()) {
1472 fields_sorted[j + 0] = fd.offset();
1473 fields_sorted[j + 1] = i;
1474 j += 2;
1475 }
1476 }
1477 if (j > 0) {
1478 length = j;
1479 // _sort_Fn is defined in growableArray.hpp.
1480 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1481 for (int i = 0; i < length; i += 2) {
1482 fd.reinitialize(this, fields_sorted[i + 1]);
1483 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1484 cl->do_field(&fd);
1485 }
1486 }
1487 FREE_C_HEAP_ARRAY(int, fields_sorted);
1488 }
1489
1490
1491 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1492 if (array_klasses() != NULL)
1493 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1494 }
1495
1496 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1497 if (array_klasses() != NULL)
1498 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1499 }
1500
1501 #ifdef ASSERT
1502 static int linear_search(const Array<Method*>* methods,
1503 const Symbol* name,
1504 const Symbol* signature) {
1505 const int len = methods->length();
1506 for (int index = 0; index < len; index++) {
1507 const Method* const m = methods->at(index);
1508 assert(m->is_method(), "must be method");
1509 if (m->signature() == signature && m->name() == name) {
1510 return index;
1511 }
1512 }
1513 return -1;
1514 }
1515 #endif
1516
1517 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1518 int len = methods->length();
1519 // methods are sorted, so do binary search
1520 int l = 0;
1521 int h = len - 1;
1522 while (l <= h) {
1523 int mid = (l + h) >> 1;
1524 Method* m = methods->at(mid);
1525 assert(m->is_method(), "must be method");
1526 int res = m->name()->fast_compare(name);
1527 if (res == 0) {
1528 return mid;
1529 } else if (res < 0) {
1530 l = mid + 1;
1531 } else {
1532 h = mid - 1;
1533 }
1534 }
1535 return -1;
1536 }
1537
1538 // find_method looks up the name/signature in the local methods array
1539 Method* InstanceKlass::find_method(const Symbol* name,
1540 const Symbol* signature) const {
1541 return find_method_impl(name, signature, find_overpass, find_static, find_private);
1542 }
1543
1544 Method* InstanceKlass::find_method_impl(const Symbol* name,
1545 const Symbol* signature,
1546 OverpassLookupMode overpass_mode,
1547 StaticLookupMode static_mode,
1548 PrivateLookupMode private_mode) const {
1549 return InstanceKlass::find_method_impl(methods(),
1550 name,
1551 signature,
1552 overpass_mode,
1553 static_mode,
1554 private_mode);
1555 }
1556
1557 // find_instance_method looks up the name/signature in the local methods array
1558 // and skips over static methods
1559 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1560 const Symbol* name,
1561 const Symbol* signature,
1562 PrivateLookupMode private_mode) {
1563 Method* const meth = InstanceKlass::find_method_impl(methods,
1564 name,
1565 signature,
1566 find_overpass,
1567 skip_static,
1568 private_mode);
1569 assert(((meth == NULL) || !meth->is_static()),
1570 "find_instance_method should have skipped statics");
1571 return meth;
1572 }
1573
1574 // find_instance_method looks up the name/signature in the local methods array
1575 // and skips over static methods
1576 Method* InstanceKlass::find_instance_method(const Symbol* name,
1577 const Symbol* signature,
1578 PrivateLookupMode private_mode) const {
1579 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1580 }
1581
1582 // Find looks up the name/signature in the local methods array
1583 // and filters on the overpass, static and private flags
1584 // This returns the first one found
1585 // note that the local methods array can have up to one overpass, one static
1586 // and one instance (private or not) with the same name/signature
1587 Method* InstanceKlass::find_local_method(const Symbol* name,
1588 const Symbol* signature,
1589 OverpassLookupMode overpass_mode,
1590 StaticLookupMode static_mode,
1591 PrivateLookupMode private_mode) const {
1592 return InstanceKlass::find_method_impl(methods(),
1593 name,
1594 signature,
1595 overpass_mode,
1596 static_mode,
1597 private_mode);
1598 }
1599
1600 // Find looks up the name/signature in the local methods array
1601 // and filters on the overpass, static and private flags
1602 // This returns the first one found
1603 // note that the local methods array can have up to one overpass, one static
1604 // and one instance (private or not) with the same name/signature
1605 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1606 const Symbol* name,
1607 const Symbol* signature,
1608 OverpassLookupMode overpass_mode,
1609 StaticLookupMode static_mode,
1610 PrivateLookupMode private_mode) {
1611 return InstanceKlass::find_method_impl(methods,
1612 name,
1613 signature,
1614 overpass_mode,
1615 static_mode,
1616 private_mode);
1617 }
1618
1619 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1620 const Symbol* name,
1621 const Symbol* signature) {
1622 return InstanceKlass::find_method_impl(methods,
1623 name,
1624 signature,
1625 find_overpass,
1626 find_static,
1627 find_private);
1628 }
1629
1630 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1631 const Symbol* name,
1632 const Symbol* signature,
1633 OverpassLookupMode overpass_mode,
1634 StaticLookupMode static_mode,
1635 PrivateLookupMode private_mode) {
1636 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1637 return hit >= 0 ? methods->at(hit): NULL;
1638 }
1639
1640 // true if method matches signature and conforms to skipping_X conditions.
1641 static bool method_matches(const Method* m,
1642 const Symbol* signature,
1643 bool skipping_overpass,
1644 bool skipping_static,
1645 bool skipping_private) {
1646 return ((m->signature() == signature) &&
1647 (!skipping_overpass || !m->is_overpass()) &&
1648 (!skipping_static || !m->is_static()) &&
1649 (!skipping_private || !m->is_private()));
1650 }
1651
1652 // Used directly for default_methods to find the index into the
1653 // default_vtable_indices, and indirectly by find_method
1654 // find_method_index looks in the local methods array to return the index
1655 // of the matching name/signature. If, overpass methods are being ignored,
1656 // the search continues to find a potential non-overpass match. This capability
1657 // is important during method resolution to prefer a static method, for example,
1658 // over an overpass method.
1659 // There is the possibility in any _method's array to have the same name/signature
1660 // for a static method, an overpass method and a local instance method
1661 // To correctly catch a given method, the search criteria may need
1662 // to explicitly skip the other two. For local instance methods, it
1663 // is often necessary to skip private methods
1664 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1665 const Symbol* name,
1666 const Symbol* signature,
1667 OverpassLookupMode overpass_mode,
1668 StaticLookupMode static_mode,
1669 PrivateLookupMode private_mode) {
1670 const bool skipping_overpass = (overpass_mode == skip_overpass);
1671 const bool skipping_static = (static_mode == skip_static);
1672 const bool skipping_private = (private_mode == skip_private);
1673 const int hit = binary_search(methods, name);
1674 if (hit != -1) {
1675 const Method* const m = methods->at(hit);
1676
1677 // Do linear search to find matching signature. First, quick check
1678 // for common case, ignoring overpasses if requested.
1679 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1680 return hit;
1681 }
1682
1683 // search downwards through overloaded methods
1684 int i;
1685 for (i = hit - 1; i >= 0; --i) {
1686 const Method* const m = methods->at(i);
1687 assert(m->is_method(), "must be method");
1688 if (m->name() != name) {
1689 break;
1690 }
1691 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1692 return i;
1693 }
1694 }
1695 // search upwards
1696 for (i = hit + 1; i < methods->length(); ++i) {
1697 const Method* const m = methods->at(i);
1698 assert(m->is_method(), "must be method");
1699 if (m->name() != name) {
1700 break;
1701 }
1702 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1703 return i;
1704 }
1705 }
1706 // not found
1707 #ifdef ASSERT
1708 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1709 linear_search(methods, name, signature);
1710 assert(-1 == index, "binary search should have found entry %d", index);
1711 #endif
1712 }
1713 return -1;
1714 }
1715
1716 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1717 return find_method_by_name(methods(), name, end);
1718 }
1719
1720 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1721 const Symbol* name,
1722 int* end_ptr) {
1723 assert(end_ptr != NULL, "just checking");
1724 int start = binary_search(methods, name);
1725 int end = start + 1;
1726 if (start != -1) {
1727 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1728 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1729 *end_ptr = end;
1730 return start;
1731 }
1732 return -1;
1733 }
1734
1735 // uncached_lookup_method searches both the local class methods array and all
1736 // superclasses methods arrays, skipping any overpass methods in superclasses,
1737 // and possibly skipping private methods.
1738 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1739 const Symbol* signature,
1740 OverpassLookupMode overpass_mode,
1741 PrivateLookupMode private_mode) const {
1742 OverpassLookupMode overpass_local_mode = overpass_mode;
1743 const Klass* klass = this;
1744 while (klass != NULL) {
1745 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1746 signature,
1747 overpass_local_mode,
1748 find_static,
1749 private_mode);
1750 if (method != NULL) {
1751 return method;
1752 }
1753 klass = klass->super();
1754 overpass_local_mode = skip_overpass; // Always ignore overpass methods in superclasses
1755 }
1756 return NULL;
1757 }
1758
1759 #ifdef ASSERT
1760 // search through class hierarchy and return true if this class or
1761 // one of the superclasses was redefined
1762 bool InstanceKlass::has_redefined_this_or_super() const {
1763 const Klass* klass = this;
1764 while (klass != NULL) {
1765 if (InstanceKlass::cast(klass)->has_been_redefined()) {
1766 return true;
1767 }
1768 klass = klass->super();
1769 }
1770 return false;
1771 }
1772 #endif
1773
1774 // lookup a method in the default methods list then in all transitive interfaces
1775 // Do NOT return private or static methods
1776 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1777 Symbol* signature) const {
1778 Method* m = NULL;
1779 if (default_methods() != NULL) {
1780 m = find_method(default_methods(), name, signature);
1781 }
1782 // Look up interfaces
1783 if (m == NULL) {
1784 m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1785 }
1786 return m;
1787 }
1788
1789 // lookup a method in all the interfaces that this class implements
1790 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1791 // They should only be found in the initial InterfaceMethodRef
1792 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1793 Symbol* signature,
1794 DefaultsLookupMode defaults_mode) const {
1795 Array<Klass*>* all_ifs = transitive_interfaces();
1796 int num_ifs = all_ifs->length();
1797 InstanceKlass *ik = NULL;
1798 for (int i = 0; i < num_ifs; i++) {
1799 ik = InstanceKlass::cast(all_ifs->at(i));
1800 Method* m = ik->lookup_method(name, signature);
1801 if (m != NULL && m->is_public() && !m->is_static() &&
1802 ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1803 return m;
1804 }
1805 }
1806 return NULL;
1807 }
1808
1809 /* jni_id_for_impl for jfieldIds only */
1810 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1811 MutexLocker ml(JfieldIdCreation_lock);
1812 // Retry lookup after we got the lock
1813 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1814 if (probe == NULL) {
1815 // Slow case, allocate new static field identifier
1816 probe = new JNIid(this, offset, jni_ids());
1817 set_jni_ids(probe);
1818 }
1819 return probe;
1820 }
1821
1822
1823 /* jni_id_for for jfieldIds only */
1824 JNIid* InstanceKlass::jni_id_for(int offset) {
1825 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1826 if (probe == NULL) {
1827 probe = jni_id_for_impl(offset);
1828 }
1829 return probe;
1830 }
1831
1832 u2 InstanceKlass::enclosing_method_data(int offset) const {
1833 const Array<jushort>* const inner_class_list = inner_classes();
1834 if (inner_class_list == NULL) {
1835 return 0;
1836 }
1837 const int length = inner_class_list->length();
1838 if (length % inner_class_next_offset == 0) {
1839 return 0;
1840 }
1841 const int index = length - enclosing_method_attribute_size;
1842 assert(offset < enclosing_method_attribute_size, "invalid offset");
1843 return inner_class_list->at(index + offset);
1844 }
1845
1846 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1847 u2 method_index) {
1848 Array<jushort>* inner_class_list = inner_classes();
1849 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1850 int length = inner_class_list->length();
1851 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1852 int index = length - enclosing_method_attribute_size;
1853 inner_class_list->at_put(
1854 index + enclosing_method_class_index_offset, class_index);
1855 inner_class_list->at_put(
1856 index + enclosing_method_method_index_offset, method_index);
1857 }
1858 }
1859
1860 // Lookup or create a jmethodID.
1861 // This code is called by the VMThread and JavaThreads so the
1862 // locking has to be done very carefully to avoid deadlocks
1863 // and/or other cache consistency problems.
1864 //
1865 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
1866 size_t idnum = (size_t)method_h->method_idnum();
1867 jmethodID* jmeths = methods_jmethod_ids_acquire();
1868 size_t length = 0;
1869 jmethodID id = NULL;
1870
1871 // We use a double-check locking idiom here because this cache is
1872 // performance sensitive. In the normal system, this cache only
1873 // transitions from NULL to non-NULL which is safe because we use
1874 // release_set_methods_jmethod_ids() to advertise the new cache.
1875 // A partially constructed cache should never be seen by a racing
1876 // thread. We also use release_store() to save a new jmethodID
1877 // in the cache so a partially constructed jmethodID should never be
1878 // seen either. Cache reads of existing jmethodIDs proceed without a
1879 // lock, but cache writes of a new jmethodID requires uniqueness and
1880 // creation of the cache itself requires no leaks so a lock is
1881 // generally acquired in those two cases.
1882 //
1883 // If the RedefineClasses() API has been used, then this cache can
1884 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1885 // Cache creation requires no leaks and we require safety between all
1886 // cache accesses and freeing of the old cache so a lock is generally
1887 // acquired when the RedefineClasses() API has been used.
1888
1889 if (jmeths != NULL) {
1890 // the cache already exists
1891 if (!idnum_can_increment()) {
1892 // the cache can't grow so we can just get the current values
1893 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1894 } else {
1895 // cache can grow so we have to be more careful
1896 if (Threads::number_of_threads() == 0 ||
1897 SafepointSynchronize::is_at_safepoint()) {
1898 // we're single threaded or at a safepoint - no locking needed
1899 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1900 } else {
1901 MutexLocker ml(JmethodIdCreation_lock);
1902 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1903 }
1904 }
1905 }
1906 // implied else:
1907 // we need to allocate a cache so default length and id values are good
1908
1909 if (jmeths == NULL || // no cache yet
1910 length <= idnum || // cache is too short
1911 id == NULL) { // cache doesn't contain entry
1912
1913 // This function can be called by the VMThread so we have to do all
1914 // things that might block on a safepoint before grabbing the lock.
1915 // Otherwise, we can deadlock with the VMThread or have a cache
1916 // consistency issue. These vars keep track of what we might have
1917 // to free after the lock is dropped.
1918 jmethodID to_dealloc_id = NULL;
1919 jmethodID* to_dealloc_jmeths = NULL;
1920
1921 // may not allocate new_jmeths or use it if we allocate it
1922 jmethodID* new_jmeths = NULL;
1923 if (length <= idnum) {
1924 // allocate a new cache that might be used
1925 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1926 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1927 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1928 // cache size is stored in element[0], other elements offset by one
1929 new_jmeths[0] = (jmethodID)size;
1930 }
1931
1932 // allocate a new jmethodID that might be used
1933 jmethodID new_id = NULL;
1934 if (method_h->is_old() && !method_h->is_obsolete()) {
1935 // The method passed in is old (but not obsolete), we need to use the current version
1936 Method* current_method = method_with_idnum((int)idnum);
1937 assert(current_method != NULL, "old and but not obsolete, so should exist");
1938 new_id = Method::make_jmethod_id(class_loader_data(), current_method);
1939 } else {
1940 // It is the current version of the method or an obsolete method,
1941 // use the version passed in
1942 new_id = Method::make_jmethod_id(class_loader_data(), method_h());
1943 }
1944
1945 if (Threads::number_of_threads() == 0 ||
1946 SafepointSynchronize::is_at_safepoint()) {
1947 // we're single threaded or at a safepoint - no locking needed
1948 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1949 &to_dealloc_id, &to_dealloc_jmeths);
1950 } else {
1951 MutexLocker ml(JmethodIdCreation_lock);
1952 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1953 &to_dealloc_id, &to_dealloc_jmeths);
1954 }
1955
1956 // The lock has been dropped so we can free resources.
1957 // Free up either the old cache or the new cache if we allocated one.
1958 if (to_dealloc_jmeths != NULL) {
1959 FreeHeap(to_dealloc_jmeths);
1960 }
1961 // free up the new ID since it wasn't needed
1962 if (to_dealloc_id != NULL) {
1963 Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
1964 }
1965 }
1966 return id;
1967 }
1968
1969 // Figure out how many jmethodIDs haven't been allocated, and make
1970 // sure space for them is pre-allocated. This makes getting all
1971 // method ids much, much faster with classes with more than 8
1972 // methods, and has a *substantial* effect on performance with jvmti
1973 // code that loads all jmethodIDs for all classes.
1974 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1975 int new_jmeths = 0;
1976 int length = methods()->length();
1977 for (int index = start_offset; index < length; index++) {
1978 Method* m = methods()->at(index);
1979 jmethodID id = m->find_jmethod_id_or_null();
1980 if (id == NULL) {
1981 new_jmeths++;
1982 }
1983 }
1984 if (new_jmeths != 0) {
1985 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1986 }
1987 }
1988
1989 // Common code to fetch the jmethodID from the cache or update the
1990 // cache with the new jmethodID. This function should never do anything
1991 // that causes the caller to go to a safepoint or we can deadlock with
1992 // the VMThread or have cache consistency issues.
1993 //
1994 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1995 size_t idnum, jmethodID new_id,
1996 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1997 jmethodID** to_dealloc_jmeths_p) {
1998 assert(new_id != NULL, "sanity check");
1999 assert(to_dealloc_id_p != NULL, "sanity check");
2000 assert(to_dealloc_jmeths_p != NULL, "sanity check");
2001 assert(Threads::number_of_threads() == 0 ||
2002 SafepointSynchronize::is_at_safepoint() ||
2003 JmethodIdCreation_lock->owned_by_self(), "sanity check");
2004
2005 // reacquire the cache - we are locked, single threaded or at a safepoint
2006 jmethodID* jmeths = methods_jmethod_ids_acquire();
2007 jmethodID id = NULL;
2008 size_t length = 0;
2009
2010 if (jmeths == NULL || // no cache yet
2011 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
2012 if (jmeths != NULL) {
2013 // copy any existing entries from the old cache
2014 for (size_t index = 0; index < length; index++) {
2015 new_jmeths[index+1] = jmeths[index+1];
2016 }
2017 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
2018 }
2019 release_set_methods_jmethod_ids(jmeths = new_jmeths);
2020 } else {
2021 // fetch jmethodID (if any) from the existing cache
2022 id = jmeths[idnum+1];
2023 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
2024 }
2025 if (id == NULL) {
2026 // No matching jmethodID in the existing cache or we have a new
2027 // cache or we just grew the cache. This cache write is done here
2028 // by the first thread to win the foot race because a jmethodID
2029 // needs to be unique once it is generally available.
2030 id = new_id;
2031
2032 // The jmethodID cache can be read while unlocked so we have to
2033 // make sure the new jmethodID is complete before installing it
2034 // in the cache.
2035 OrderAccess::release_store(&jmeths[idnum+1], id);
2036 } else {
2037 *to_dealloc_id_p = new_id; // save new id for later delete
2038 }
2039 return id;
2040 }
2041
2042
2043 // Common code to get the jmethodID cache length and the jmethodID
2044 // value at index idnum if there is one.
2045 //
2046 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
2047 size_t idnum, size_t *length_p, jmethodID* id_p) {
2048 assert(cache != NULL, "sanity check");
2049 assert(length_p != NULL, "sanity check");
2050 assert(id_p != NULL, "sanity check");
2051
2052 // cache size is stored in element[0], other elements offset by one
2053 *length_p = (size_t)cache[0];
2054 if (*length_p <= idnum) { // cache is too short
2055 *id_p = NULL;
2056 } else {
2057 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
2058 }
2059 }
2060
2061
2062 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
2063 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2064 size_t idnum = (size_t)method->method_idnum();
2065 jmethodID* jmeths = methods_jmethod_ids_acquire();
2066 size_t length; // length assigned as debugging crumb
2067 jmethodID id = NULL;
2068 if (jmeths != NULL && // If there is a cache
2069 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
2070 id = jmeths[idnum+1]; // Look up the id (may be NULL)
2071 }
2072 return id;
2073 }
2074
2075 inline DependencyContext InstanceKlass::dependencies() {
2076 DependencyContext dep_context(&_dep_context);
2077 return dep_context;
2078 }
2079
2080 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
2081 return dependencies().mark_dependent_nmethods(changes);
2082 }
2083
2084 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2085 dependencies().add_dependent_nmethod(nm);
2086 }
2087
2088 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
2089 dependencies().remove_dependent_nmethod(nm, delete_immediately);
2090 }
2091
2092 #ifndef PRODUCT
2093 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2094 dependencies().print_dependent_nmethods(verbose);
2095 }
2096
2097 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2098 return dependencies().is_dependent_nmethod(nm);
2099 }
2100 #endif //PRODUCT
2101
2102 void InstanceKlass::clean_weak_instanceklass_links() {
2103 clean_implementors_list();
2104 clean_method_data();
2105
2106 // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here.
2107 DependencyContext dep_context(&_dep_context);
2108 dep_context.expunge_stale_entries();
2109 }
2110
2111 void InstanceKlass::clean_implementors_list() {
2112 assert(is_loader_alive(), "this klass should be live");
2113 if (is_interface()) {
2114 if (ClassUnloading) {
2115 Klass* impl = implementor();
2116 if (impl != NULL) {
2117 if (!impl->is_loader_alive()) {
2118 // remove this guy
2119 Klass** klass = adr_implementor();
2120 assert(klass != NULL, "null klass");
2121 if (klass != NULL) {
2122 *klass = NULL;
2123 }
2124 }
2125 }
2126 }
2127 }
2128 }
2129
2130 void InstanceKlass::clean_method_data() {
2131 for (int m = 0; m < methods()->length(); m++) {
2132 MethodData* mdo = methods()->at(m)->method_data();
2133 if (mdo != NULL) {
2134 mdo->clean_method_data(/*always_clean*/false);
2135 }
2136 }
2137 }
2138
2139 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
2140 if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
2141 ResourceMark rm;
2142 log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
2143 return false;
2144 }
2145
2146 Array<Klass*>* local_interfaces = this->local_interfaces();
2147 if (local_interfaces != NULL) {
2148 int length = local_interfaces->length();
2149 for (int i = 0; i < length; i++) {
2150 InstanceKlass* intf = InstanceKlass::cast(local_interfaces->at(i));
2151 if (!intf->has_passed_fingerprint_check()) {
2152 ResourceMark rm;
2153 log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
2154 return false;
2155 }
2156 }
2157 }
2158
2159 return true;
2160 }
2161
2162 bool InstanceKlass::should_store_fingerprint(bool is_anonymous) {
2163 #if INCLUDE_AOT
2164 // We store the fingerprint into the InstanceKlass only in the following 2 cases:
2165 if (CalculateClassFingerprint) {
2166 // (1) We are running AOT to generate a shared library.
2167 return true;
2168 }
2169 if (DumpSharedSpaces) {
2170 // (2) We are running -Xshare:dump to create a shared archive
2171 return true;
2172 }
2173 if (UseAOT && is_anonymous) {
2174 // (3) We are using AOT code from a shared library and see an anonymous class
2175 return true;
2176 }
2177 #endif
2178
2179 // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
2180 // but do not store the 64-bit fingerprint to save space.
2181 return false;
2182 }
2183
2184 bool InstanceKlass::has_stored_fingerprint() const {
2185 #if INCLUDE_AOT
2186 return should_store_fingerprint() || is_shared();
2187 #else
2188 return false;
2189 #endif
2190 }
2191
2192 uint64_t InstanceKlass::get_stored_fingerprint() const {
2193 address adr = adr_fingerprint();
2194 if (adr != NULL) {
2195 return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
2196 }
2197 return 0;
2198 }
2199
2200 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
2201 address adr = adr_fingerprint();
2202 if (adr != NULL) {
2203 Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2204
2205 ResourceMark rm;
2206 log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2207 }
2208 }
2209
2210 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2211 Klass::metaspace_pointers_do(it);
2212
2213 if (log_is_enabled(Trace, cds)) {
2214 ResourceMark rm;
2215 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2216 }
2217
2218 it->push(&_annotations);
2219 it->push((Klass**)&_array_klasses);
2220 it->push(&_constants);
2221 it->push(&_inner_classes);
2222 it->push(&_array_name);
2223 #if INCLUDE_JVMTI
2224 it->push(&_previous_versions);
2225 #endif
2226 it->push(&_methods);
2227 it->push(&_default_methods);
2228 it->push(&_local_interfaces);
2229 it->push(&_transitive_interfaces);
2230 it->push(&_method_ordering);
2231 it->push(&_default_vtable_indices);
2232 it->push(&_fields);
2233
2234 if (itable_length() > 0) {
2235 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2236 int method_table_offset_in_words = ioe->offset()/wordSize;
2237 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2238 / itableOffsetEntry::size();
2239
2240 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2241 if (ioe->interface_klass() != NULL) {
2242 it->push(ioe->interface_klass_addr());
2243 itableMethodEntry* ime = ioe->first_method_entry(this);
2244 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2245 for (int index = 0; index < n; index ++) {
2246 it->push(ime[index].method_addr());
2247 }
2248 }
2249 }
2250 }
2251
2252 it->push(&_nest_members);
2253 }
2254
2255 void InstanceKlass::remove_unshareable_info() {
2256 Klass::remove_unshareable_info();
2257
2258 if (is_in_error_state()) {
2259 // Classes are attempted to link during dumping and may fail,
2260 // but these classes are still in the dictionary and class list in CLD.
2261 // Check in_error state first because in_error is > linked state, so
2262 // is_linked() is true.
2263 // If there's a linking error, there is nothing else to remove.
2264 return;
2265 }
2266
2267 // Unlink the class
2268 if (is_linked()) {
2269 unlink_class();
2270 }
2271 init_implementor();
2272
2273 constants()->remove_unshareable_info();
2274
2275 for (int i = 0; i < methods()->length(); i++) {
2276 Method* m = methods()->at(i);
2277 m->remove_unshareable_info();
2278 }
2279
2280 // do array classes also.
2281 if (array_klasses() != NULL) {
2282 array_klasses()->remove_unshareable_info();
2283 }
2284
2285 // These are not allocated from metaspace, but they should should all be empty
2286 // during dump time, so we don't need to worry about them in InstanceKlass::iterate().
2287 guarantee(_source_debug_extension == NULL, "must be");
2288 guarantee(_dep_context == DependencyContext::EMPTY, "must be");
2289 guarantee(_osr_nmethods_head == NULL, "must be");
2290
2291 #if INCLUDE_JVMTI
2292 guarantee(_breakpoints == NULL, "must be");
2293 guarantee(_previous_versions == NULL, "must be");
2294 #endif
2295
2296 _init_thread = NULL;
2297 _methods_jmethod_ids = NULL;
2298 _jni_ids = NULL;
2299 _oop_map_cache = NULL;
2300 // clear _nest_host to ensure re-load at runtime
2301 _nest_host = NULL;
2302 }
2303
2304 void InstanceKlass::remove_java_mirror() {
2305 Klass::remove_java_mirror();
2306
2307 // do array classes also.
2308 if (array_klasses() != NULL) {
2309 array_klasses()->remove_java_mirror();
2310 }
2311 }
2312
2313 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2314 set_package(loader_data, CHECK);
2315 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2316
2317 Array<Method*>* methods = this->methods();
2318 int num_methods = methods->length();
2319 for (int index2 = 0; index2 < num_methods; ++index2) {
2320 methodHandle m(THREAD, methods->at(index2));
2321 m->restore_unshareable_info(CHECK);
2322 }
2323 if (JvmtiExport::has_redefined_a_class()) {
2324 // Reinitialize vtable because RedefineClasses may have changed some
2325 // entries in this vtable for super classes so the CDS vtable might
2326 // point to old or obsolete entries. RedefineClasses doesn't fix up
2327 // vtables in the shared system dictionary, only the main one.
2328 // It also redefines the itable too so fix that too.
2329 ResourceMark rm(THREAD);
2330 vtable().initialize_vtable(false, CHECK);
2331 itable().initialize_itable(false, CHECK);
2332 }
2333
2334 // restore constant pool resolved references
2335 constants()->restore_unshareable_info(CHECK);
2336
2337 if (array_klasses() != NULL) {
2338 // Array classes have null protection domain.
2339 // --> see ArrayKlass::complete_create_array_klass()
2340 array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2341 }
2342 }
2343
2344 // returns true IFF is_in_error_state() has been changed as a result of this call.
2345 bool InstanceKlass::check_sharing_error_state() {
2346 assert(DumpSharedSpaces, "should only be called during dumping");
2347 bool old_state = is_in_error_state();
2348
2349 if (!is_in_error_state()) {
2350 bool bad = false;
2351 for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2352 if (sup->is_in_error_state()) {
2353 bad = true;
2354 break;
2355 }
2356 }
2357 if (!bad) {
2358 Array<Klass*>* interfaces = transitive_interfaces();
2359 for (int i = 0; i < interfaces->length(); i++) {
2360 Klass* iface = interfaces->at(i);
2361 if (InstanceKlass::cast(iface)->is_in_error_state()) {
2362 bad = true;
2363 break;
2364 }
2365 }
2366 }
2367
2368 if (bad) {
2369 set_in_error_state();
2370 }
2371 }
2372
2373 return (old_state != is_in_error_state());
2374 }
2375
2376 #if INCLUDE_JVMTI
2377 static void clear_all_breakpoints(Method* m) {
2378 m->clear_all_breakpoints();
2379 }
2380 #endif
2381
2382 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2383 // notify the debugger
2384 if (JvmtiExport::should_post_class_unload()) {
2385 JvmtiExport::post_class_unload(ik);
2386 }
2387
2388 // notify ClassLoadingService of class unload
2389 ClassLoadingService::notify_class_unloaded(ik);
2390 }
2391
2392 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2393 // Clean up C heap
2394 ik->release_C_heap_structures();
2395 ik->constants()->release_C_heap_structures();
2396 }
2397
2398 void InstanceKlass::release_C_heap_structures() {
2399 // Can't release the constant pool here because the constant pool can be
2400 // deallocated separately from the InstanceKlass for default methods and
2401 // redefine classes.
2402
2403 // Deallocate oop map cache
2404 if (_oop_map_cache != NULL) {
2405 delete _oop_map_cache;
2406 _oop_map_cache = NULL;
2407 }
2408
2409 // Deallocate JNI identifiers for jfieldIDs
2410 JNIid::deallocate(jni_ids());
2411 set_jni_ids(NULL);
2412
2413 jmethodID* jmeths = methods_jmethod_ids_acquire();
2414 if (jmeths != (jmethodID*)NULL) {
2415 release_set_methods_jmethod_ids(NULL);
2416 FreeHeap(jmeths);
2417 }
2418
2419 // Release dependencies.
2420 // It is desirable to use DC::remove_all_dependents() here, but, unfortunately,
2421 // it is not safe (see JDK-8143408). The problem is that the klass dependency
2422 // context can contain live dependencies, since there's a race between nmethod &
2423 // klass unloading. If the klass is dead when nmethod unloading happens, relevant
2424 // dependencies aren't removed from the context associated with the class (see
2425 // nmethod::flush_dependencies). It ends up during klass unloading as seemingly
2426 // live dependencies pointing to unloaded nmethods and causes a crash in
2427 // DC::remove_all_dependents() when it touches unloaded nmethod.
2428 dependencies().wipe();
2429
2430 #if INCLUDE_JVMTI
2431 // Deallocate breakpoint records
2432 if (breakpoints() != 0x0) {
2433 methods_do(clear_all_breakpoints);
2434 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2435 }
2436
2437 // deallocate the cached class file
2438 if (_cached_class_file != NULL && !MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
2439 os::free(_cached_class_file);
2440 _cached_class_file = NULL;
2441 }
2442 #endif
2443
2444 // Decrement symbol reference counts associated with the unloaded class.
2445 if (_name != NULL) _name->decrement_refcount();
2446 // unreference array name derived from this class name (arrays of an unloaded
2447 // class can't be referenced anymore).
2448 if (_array_name != NULL) _array_name->decrement_refcount();
2449 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2450 }
2451
2452 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2453 if (array == NULL) {
2454 _source_debug_extension = NULL;
2455 } else {
2456 // Adding one to the attribute length in order to store a null terminator
2457 // character could cause an overflow because the attribute length is
2458 // already coded with an u4 in the classfile, but in practice, it's
2459 // unlikely to happen.
2460 assert((length+1) > length, "Overflow checking");
2461 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2462 for (int i = 0; i < length; i++) {
2463 sde[i] = array[i];
2464 }
2465 sde[length] = '\0';
2466 _source_debug_extension = sde;
2467 }
2468 }
2469
2470 const char* InstanceKlass::signature_name() const {
2471 int hash_len = 0;
2472 char hash_buf[40];
2473
2474 // If this is an anonymous class, append a hash to make the name unique
2475 if (is_anonymous()) {
2476 intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2477 jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2478 hash_len = (int)strlen(hash_buf);
2479 }
2480
2481 // Get the internal name as a c string
2482 const char* src = (const char*) (name()->as_C_string());
2483 const int src_length = (int)strlen(src);
2484
2485 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2486
2487 // Add L as type indicator
2488 int dest_index = 0;
2489 dest[dest_index++] = 'L';
2490
2491 // Add the actual class name
2492 for (int src_index = 0; src_index < src_length; ) {
2493 dest[dest_index++] = src[src_index++];
2494 }
2495
2496 // If we have a hash, append it
2497 for (int hash_index = 0; hash_index < hash_len; ) {
2498 dest[dest_index++] = hash_buf[hash_index++];
2499 }
2500
2501 // Add the semicolon and the NULL
2502 dest[dest_index++] = ';';
2503 dest[dest_index] = '\0';
2504 return dest;
2505 }
2506
2507 // Used to obtain the package name from a fully qualified class name.
2508 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2509 if (name == NULL) {
2510 return NULL;
2511 } else {
2512 if (name->utf8_length() <= 0) {
2513 return NULL;
2514 }
2515 ResourceMark rm;
2516 const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2517 if (package_name == NULL) {
2518 return NULL;
2519 }
2520 Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD);
2521 return pkg_name;
2522 }
2523 }
2524
2525 ModuleEntry* InstanceKlass::module() const {
2526 if (!in_unnamed_package()) {
2527 return _package_entry->module();
2528 }
2529 const Klass* host = host_klass();
2530 if (host == NULL) {
2531 return class_loader_data()->unnamed_module();
2532 }
2533 return host->class_loader_data()->unnamed_module();
2534 }
2535
2536 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2537
2538 // ensure java/ packages only loaded by boot or platform builtin loaders
2539 check_prohibited_package(name(), loader_data, CHECK);
2540
2541 TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2542
2543 if (pkg_name != NULL && loader_data != NULL) {
2544
2545 // Find in class loader's package entry table.
2546 _package_entry = loader_data->packages()->lookup_only(pkg_name);
2547
2548 // If the package name is not found in the loader's package
2549 // entry table, it is an indication that the package has not
2550 // been defined. Consider it defined within the unnamed module.
2551 if (_package_entry == NULL) {
2552 ResourceMark rm;
2553
2554 if (!ModuleEntryTable::javabase_defined()) {
2555 // Before java.base is defined during bootstrapping, define all packages in
2556 // the java.base module. If a non-java.base package is erroneously placed
2557 // in the java.base module it will be caught later when java.base
2558 // is defined by ModuleEntryTable::verify_javabase_packages check.
2559 assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2560 _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2561 } else {
2562 assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2563 _package_entry = loader_data->packages()->lookup(pkg_name,
2564 loader_data->unnamed_module());
2565 }
2566
2567 // A package should have been successfully created
2568 assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2569 name()->as_C_string(), loader_data->loader_name_and_id());
2570 }
2571
2572 if (log_is_enabled(Debug, module)) {
2573 ResourceMark rm;
2574 ModuleEntry* m = _package_entry->module();
2575 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2576 external_name(),
2577 pkg_name->as_C_string(),
2578 loader_data->loader_name_and_id(),
2579 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2580 }
2581 } else {
2582 ResourceMark rm;
2583 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2584 external_name(),
2585 (loader_data != NULL) ? loader_data->loader_name_and_id() : "NULL",
2586 UNNAMED_MODULE);
2587 }
2588 }
2589
2590
2591 // different versions of is_same_class_package
2592
2593 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2594 oop classloader1 = this->class_loader();
2595 PackageEntry* classpkg1 = this->package();
2596 if (class2->is_objArray_klass()) {
2597 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2598 }
2599
2600 oop classloader2;
2601 PackageEntry* classpkg2;
2602 if (class2->is_instance_klass()) {
2603 classloader2 = class2->class_loader();
2604 classpkg2 = class2->package();
2605 } else {
2606 assert(class2->is_typeArray_klass(), "should be type array");
2607 classloader2 = NULL;
2608 classpkg2 = NULL;
2609 }
2610
2611 // Same package is determined by comparing class loader
2612 // and package entries. Both must be the same. This rule
2613 // applies even to classes that are defined in the unnamed
2614 // package, they still must have the same class loader.
2615 if (oopDesc::equals(classloader1, classloader2) && (classpkg1 == classpkg2)) {
2616 return true;
2617 }
2618
2619 return false;
2620 }
2621
2622 // return true if this class and other_class are in the same package. Classloader
2623 // and classname information is enough to determine a class's package
2624 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2625 const Symbol* other_class_name) const {
2626 if (!oopDesc::equals(class_loader(), other_class_loader)) {
2627 return false;
2628 }
2629 if (name()->fast_compare(other_class_name) == 0) {
2630 return true;
2631 }
2632
2633 {
2634 ResourceMark rm;
2635
2636 bool bad_class_name = false;
2637 const char* other_pkg =
2638 ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2639 if (bad_class_name) {
2640 return false;
2641 }
2642 // Check that package_from_name() returns NULL, not "", if there is no package.
2643 assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2644
2645 const Symbol* const this_package_name =
2646 this->package() != NULL ? this->package()->name() : NULL;
2647
2648 if (this_package_name == NULL || other_pkg == NULL) {
2649 // One of the two doesn't have a package. Only return true if the other
2650 // one also doesn't have a package.
2651 return (const char*)this_package_name == other_pkg;
2652 }
2653
2654 // Check if package is identical
2655 return this_package_name->equals(other_pkg);
2656 }
2657 }
2658
2659 // Returns true iff super_method can be overridden by a method in targetclassname
2660 // See JLS 3rd edition 8.4.6.1
2661 // Assumes name-signature match
2662 // "this" is InstanceKlass of super_method which must exist
2663 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2664 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2665 // Private methods can not be overridden
2666 if (super_method->is_private()) {
2667 return false;
2668 }
2669 // If super method is accessible, then override
2670 if ((super_method->is_protected()) ||
2671 (super_method->is_public())) {
2672 return true;
2673 }
2674 // Package-private methods are not inherited outside of package
2675 assert(super_method->is_package_private(), "must be package private");
2676 return(is_same_class_package(targetclassloader(), targetclassname));
2677 }
2678
2679 // Only boot and platform class loaders can define classes in "java/" packages.
2680 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2681 ClassLoaderData* loader_data,
2682 TRAPS) {
2683 if (!loader_data->is_boot_class_loader_data() &&
2684 !loader_data->is_platform_class_loader_data() &&
2685 class_name != NULL) {
2686 ResourceMark rm(THREAD);
2687 char* name = class_name->as_C_string();
2688 if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2689 TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2690 assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2691 name = pkg_name->as_C_string();
2692 const char* class_loader_name = loader_data->loader_name_and_id();
2693 StringUtils::replace_no_expand(name, "/", ".");
2694 const char* msg_text1 = "Class loader (instance of): ";
2695 const char* msg_text2 = " tried to load prohibited package name: ";
2696 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2697 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2698 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2699 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2700 }
2701 }
2702 return;
2703 }
2704
2705 // tell if two classes have the same enclosing class (at package level)
2706 bool InstanceKlass::is_same_package_member(const Klass* class2, TRAPS) const {
2707 if (class2 == this) return true;
2708 if (!class2->is_instance_klass()) return false;
2709
2710 // must be in same package before we try anything else
2711 if (!is_same_class_package(class2))
2712 return false;
2713
2714 // As long as there is an outer_this.getEnclosingClass,
2715 // shift the search outward.
2716 const InstanceKlass* outer_this = this;
2717 for (;;) {
2718 // As we walk along, look for equalities between outer_this and class2.
2719 // Eventually, the walks will terminate as outer_this stops
2720 // at the top-level class around the original class.
2721 bool ignore_inner_is_member;
2722 const Klass* next = outer_this->compute_enclosing_class(&ignore_inner_is_member,
2723 CHECK_false);
2724 if (next == NULL) break;
2725 if (next == class2) return true;
2726 outer_this = InstanceKlass::cast(next);
2727 }
2728
2729 // Now do the same for class2.
2730 const InstanceKlass* outer2 = InstanceKlass::cast(class2);
2731 for (;;) {
2732 bool ignore_inner_is_member;
2733 Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2734 CHECK_false);
2735 if (next == NULL) break;
2736 // Might as well check the new outer against all available values.
2737 if (next == this) return true;
2738 if (next == outer_this) return true;
2739 outer2 = InstanceKlass::cast(next);
2740 }
2741
2742 // If by this point we have not found an equality between the
2743 // two classes, we know they are in separate package members.
2744 return false;
2745 }
2746
2747 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2748 constantPoolHandle i_cp(THREAD, constants());
2749 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2750 int ioff = iter.inner_class_info_index();
2751 if (ioff != 0) {
2752 // Check to see if the name matches the class we're looking for
2753 // before attempting to find the class.
2754 if (i_cp->klass_name_at_matches(this, ioff)) {
2755 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2756 if (this == inner_klass) {
2757 *ooff = iter.outer_class_info_index();
2758 *noff = iter.inner_name_index();
2759 return true;
2760 }
2761 }
2762 }
2763 }
2764 return false;
2765 }
2766
2767 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2768 InstanceKlass* outer_klass = NULL;
2769 *inner_is_member = false;
2770 int ooff = 0, noff = 0;
2771 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2772 if (has_inner_classes_attr) {
2773 constantPoolHandle i_cp(THREAD, constants());
2774 if (ooff != 0) {
2775 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2776 outer_klass = InstanceKlass::cast(ok);
2777 *inner_is_member = true;
2778 }
2779 if (NULL == outer_klass) {
2780 // It may be anonymous; try for that.
2781 int encl_method_class_idx = enclosing_method_class_index();
2782 if (encl_method_class_idx != 0) {
2783 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2784 outer_klass = InstanceKlass::cast(ok);
2785 *inner_is_member = false;
2786 }
2787 }
2788 }
2789
2790 // If no inner class attribute found for this class.
2791 if (NULL == outer_klass) return NULL;
2792
2793 // Throws an exception if outer klass has not declared k as an inner klass
2794 // We need evidence that each klass knows about the other, or else
2795 // the system could allow a spoof of an inner class to gain access rights.
2796 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2797 return outer_klass;
2798 }
2799
2800 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2801 jint access = access_flags().as_int();
2802
2803 // But check if it happens to be member class.
2804 InnerClassesIterator iter(this);
2805 for (; !iter.done(); iter.next()) {
2806 int ioff = iter.inner_class_info_index();
2807 // Inner class attribute can be zero, skip it.
2808 // Strange but true: JVM spec. allows null inner class refs.
2809 if (ioff == 0) continue;
2810
2811 // only look at classes that are already loaded
2812 // since we are looking for the flags for our self.
2813 Symbol* inner_name = constants()->klass_name_at(ioff);
2814 if (name() == inner_name) {
2815 // This is really a member class.
2816 access = iter.inner_access_flags();
2817 break;
2818 }
2819 }
2820 // Remember to strip ACC_SUPER bit
2821 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2822 }
2823
2824 jint InstanceKlass::jvmti_class_status() const {
2825 jint result = 0;
2826
2827 if (is_linked()) {
2828 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2829 }
2830
2831 if (is_initialized()) {
2832 assert(is_linked(), "Class status is not consistent");
2833 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2834 }
2835 if (is_in_error_state()) {
2836 result |= JVMTI_CLASS_STATUS_ERROR;
2837 }
2838 return result;
2839 }
2840
2841 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2842 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2843 int method_table_offset_in_words = ioe->offset()/wordSize;
2844 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2845 / itableOffsetEntry::size();
2846
2847 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2848 // If the interface isn't implemented by the receiver class,
2849 // the VM should throw IncompatibleClassChangeError.
2850 if (cnt >= nof_interfaces) {
2851 ResourceMark rm(THREAD);
2852 stringStream ss;
2853 bool same_module = (module() == holder->module());
2854 ss.print("Receiver class %s does not implement "
2855 "the interface %s defining the method to be called "
2856 "(%s%s%s)",
2857 external_name(), holder->external_name(),
2858 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
2859 (same_module) ? "" : "; ",
2860 (same_module) ? "" : holder->class_in_module_of_loader());
2861 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
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 BasicOopIterateClosure {
3434 protected:
3435 template <class T> void do_oop_work(T* p) {
3436 oop obj = RawAccess<>::oop_load(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(&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 #ifdef ASSERT
3634 void InstanceKlass::set_init_state(ClassState state) {
3635 bool good_state = is_shared() ? (_init_state <= state)
3636 : (_init_state < state);
3637 assert(good_state || state == allocated, "illegal state transition");
3638 _init_state = (u1)state;
3639 }
3640 #endif
3641
3642 #if INCLUDE_JVMTI
3643
3644 // RedefineClasses() support for previous versions
3645
3646 // Globally, there is at least one previous version of a class to walk
3647 // during class unloading, which is saved because old methods in the class
3648 // are still running. Otherwise the previous version list is cleaned up.
3649 bool InstanceKlass::_has_previous_versions = false;
3650
3651 // Returns true if there are previous versions of a class for class
3652 // unloading only. Also resets the flag to false. purge_previous_version
3653 // will set the flag to true if there are any left, i.e., if there's any
3654 // work to do for next time. This is to avoid the expensive code cache
3655 // walk in CLDG::do_unloading().
3656 bool InstanceKlass::has_previous_versions_and_reset() {
3657 bool ret = _has_previous_versions;
3658 log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3659 ret ? "true" : "false");
3660 _has_previous_versions = false;
3661 return ret;
3662 }
3663
3664 // Purge previous versions before adding new previous versions of the class and
3665 // during class unloading.
3666 void InstanceKlass::purge_previous_version_list() {
3667 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3668 assert(has_been_redefined(), "Should only be called for main class");
3669
3670 // Quick exit.
3671 if (previous_versions() == NULL) {
3672 return;
3673 }
3674
3675 // This klass has previous versions so see what we can cleanup
3676 // while it is safe to do so.
3677
3678 int deleted_count = 0; // leave debugging breadcrumbs
3679 int live_count = 0;
3680 ClassLoaderData* loader_data = class_loader_data();
3681 assert(loader_data != NULL, "should never be null");
3682
3683 ResourceMark rm;
3684 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3685
3686 // previous versions are linked together through the InstanceKlass
3687 InstanceKlass* pv_node = previous_versions();
3688 InstanceKlass* last = this;
3689 int version = 0;
3690
3691 // check the previous versions list
3692 for (; pv_node != NULL; ) {
3693
3694 ConstantPool* pvcp = pv_node->constants();
3695 assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3696
3697 if (!pvcp->on_stack()) {
3698 // If the constant pool isn't on stack, none of the methods
3699 // are executing. Unlink this previous_version.
3700 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3701 // so will be deallocated during the next phase of class unloading.
3702 log_trace(redefine, class, iklass, purge)
3703 ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3704 // For debugging purposes.
3705 pv_node->set_is_scratch_class();
3706 // Unlink from previous version list.
3707 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3708 InstanceKlass* next = pv_node->previous_versions();
3709 pv_node->link_previous_versions(NULL); // point next to NULL
3710 last->link_previous_versions(next);
3711 // Add to the deallocate list after unlinking
3712 loader_data->add_to_deallocate_list(pv_node);
3713 pv_node = next;
3714 deleted_count++;
3715 version++;
3716 continue;
3717 } else {
3718 log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3719 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3720 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3721 live_count++;
3722 // found a previous version for next time we do class unloading
3723 _has_previous_versions = true;
3724 }
3725
3726 // At least one method is live in this previous version.
3727 // Reset dead EMCP methods not to get breakpoints.
3728 // All methods are deallocated when all of the methods for this class are no
3729 // longer running.
3730 Array<Method*>* method_refs = pv_node->methods();
3731 if (method_refs != NULL) {
3732 log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3733 for (int j = 0; j < method_refs->length(); j++) {
3734 Method* method = method_refs->at(j);
3735
3736 if (!method->on_stack()) {
3737 // no breakpoints for non-running methods
3738 if (method->is_running_emcp()) {
3739 method->set_running_emcp(false);
3740 }
3741 } else {
3742 assert (method->is_obsolete() || method->is_running_emcp(),
3743 "emcp method cannot run after emcp bit is cleared");
3744 log_trace(redefine, class, iklass, purge)
3745 ("purge: %s(%s): prev method @%d in version @%d is alive",
3746 method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3747 }
3748 }
3749 }
3750 // next previous version
3751 last = pv_node;
3752 pv_node = pv_node->previous_versions();
3753 version++;
3754 }
3755 log_trace(redefine, class, iklass, purge)
3756 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3757 }
3758
3759 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3760 int emcp_method_count) {
3761 int obsolete_method_count = old_methods->length() - emcp_method_count;
3762
3763 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3764 _previous_versions != NULL) {
3765 // We have a mix of obsolete and EMCP methods so we have to
3766 // clear out any matching EMCP method entries the hard way.
3767 int local_count = 0;
3768 for (int i = 0; i < old_methods->length(); i++) {
3769 Method* old_method = old_methods->at(i);
3770 if (old_method->is_obsolete()) {
3771 // only obsolete methods are interesting
3772 Symbol* m_name = old_method->name();
3773 Symbol* m_signature = old_method->signature();
3774
3775 // previous versions are linked together through the InstanceKlass
3776 int j = 0;
3777 for (InstanceKlass* prev_version = _previous_versions;
3778 prev_version != NULL;
3779 prev_version = prev_version->previous_versions(), j++) {
3780
3781 Array<Method*>* method_refs = prev_version->methods();
3782 for (int k = 0; k < method_refs->length(); k++) {
3783 Method* method = method_refs->at(k);
3784
3785 if (!method->is_obsolete() &&
3786 method->name() == m_name &&
3787 method->signature() == m_signature) {
3788 // The current RedefineClasses() call has made all EMCP
3789 // versions of this method obsolete so mark it as obsolete
3790 log_trace(redefine, class, iklass, add)
3791 ("%s(%s): flush obsolete method @%d in version @%d",
3792 m_name->as_C_string(), m_signature->as_C_string(), k, j);
3793
3794 method->set_is_obsolete();
3795 break;
3796 }
3797 }
3798
3799 // The previous loop may not find a matching EMCP method, but
3800 // that doesn't mean that we can optimize and not go any
3801 // further back in the PreviousVersion generations. The EMCP
3802 // method for this generation could have already been made obsolete,
3803 // but there still may be an older EMCP method that has not
3804 // been made obsolete.
3805 }
3806
3807 if (++local_count >= obsolete_method_count) {
3808 // no more obsolete methods so bail out now
3809 break;
3810 }
3811 }
3812 }
3813 }
3814 }
3815
3816 // Save the scratch_class as the previous version if any of the methods are running.
3817 // The previous_versions are used to set breakpoints in EMCP methods and they are
3818 // also used to clean MethodData links to redefined methods that are no longer running.
3819 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3820 int emcp_method_count) {
3821 assert(Thread::current()->is_VM_thread(),
3822 "only VMThread can add previous versions");
3823
3824 ResourceMark rm;
3825 log_trace(redefine, class, iklass, add)
3826 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3827
3828 // Clean out old previous versions for this class
3829 purge_previous_version_list();
3830
3831 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
3832 // a previous redefinition may be made obsolete by this redefinition.
3833 Array<Method*>* old_methods = scratch_class->methods();
3834 mark_newly_obsolete_methods(old_methods, emcp_method_count);
3835
3836 // If the constant pool for this previous version of the class
3837 // is not marked as being on the stack, then none of the methods
3838 // in this previous version of the class are on the stack so
3839 // we don't need to add this as a previous version.
3840 ConstantPool* cp_ref = scratch_class->constants();
3841 if (!cp_ref->on_stack()) {
3842 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3843 // For debugging purposes.
3844 scratch_class->set_is_scratch_class();
3845 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3846 return;
3847 }
3848
3849 if (emcp_method_count != 0) {
3850 // At least one method is still running, check for EMCP methods
3851 for (int i = 0; i < old_methods->length(); i++) {
3852 Method* old_method = old_methods->at(i);
3853 if (!old_method->is_obsolete() && old_method->on_stack()) {
3854 // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3855 // we can add breakpoints for it.
3856
3857 // We set the method->on_stack bit during safepoints for class redefinition
3858 // and use this bit to set the is_running_emcp bit.
3859 // After the safepoint, the on_stack bit is cleared and the running emcp
3860 // method may exit. If so, we would set a breakpoint in a method that
3861 // is never reached, but this won't be noticeable to the programmer.
3862 old_method->set_running_emcp(true);
3863 log_trace(redefine, class, iklass, add)
3864 ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3865 } else if (!old_method->is_obsolete()) {
3866 log_trace(redefine, class, iklass, add)
3867 ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3868 }
3869 }
3870 }
3871
3872 // Add previous version if any methods are still running.
3873 // Set has_previous_version flag for processing during class unloading.
3874 _has_previous_versions = true;
3875 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3876 assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3877 scratch_class->link_previous_versions(previous_versions());
3878 link_previous_versions(scratch_class);
3879 } // end add_previous_version()
3880
3881 #endif // INCLUDE_JVMTI
3882
3883 Method* InstanceKlass::method_with_idnum(int idnum) {
3884 Method* m = NULL;
3885 if (idnum < methods()->length()) {
3886 m = methods()->at(idnum);
3887 }
3888 if (m == NULL || m->method_idnum() != idnum) {
3889 for (int index = 0; index < methods()->length(); ++index) {
3890 m = methods()->at(index);
3891 if (m->method_idnum() == idnum) {
3892 return m;
3893 }
3894 }
3895 // None found, return null for the caller to handle.
3896 return NULL;
3897 }
3898 return m;
3899 }
3900
3901
3902 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3903 if (idnum >= methods()->length()) {
3904 return NULL;
3905 }
3906 Method* m = methods()->at(idnum);
3907 if (m != NULL && m->orig_method_idnum() == idnum) {
3908 return m;
3909 }
3910 // Obsolete method idnum does not match the original idnum
3911 for (int index = 0; index < methods()->length(); ++index) {
3912 m = methods()->at(index);
3913 if (m->orig_method_idnum() == idnum) {
3914 return m;
3915 }
3916 }
3917 // None found, return null for the caller to handle.
3918 return NULL;
3919 }
3920
3921
3922 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3923 InstanceKlass* holder = get_klass_version(version);
3924 if (holder == NULL) {
3925 return NULL; // The version of klass is gone, no method is found
3926 }
3927 Method* method = holder->method_with_orig_idnum(idnum);
3928 return method;
3929 }
3930
3931 #if INCLUDE_JVMTI
3932 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
3933 if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
3934 // Ignore the archived class stream data
3935 return NULL;
3936 } else {
3937 return _cached_class_file;
3938 }
3939 }
3940
3941 jint InstanceKlass::get_cached_class_file_len() {
3942 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3943 }
3944
3945 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3946 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3947 }
3948
3949 #if INCLUDE_CDS
3950 JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() {
3951 if (DumpSharedSpaces) {
3952 return _cached_class_file;
3953 } else {
3954 assert(this->is_shared(), "class should be shared");
3955 if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
3956 return _cached_class_file;
3957 } else {
3958 return NULL;
3959 }
3960 }
3961 }
3962 #endif
3963 #endif