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.inline.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 #if INCLUDE_JFR
84 #include "utilities/ticks.hpp"
85 #include "jfr/jfr.hpp"
86 #include "jfr/jfrEvents.hpp"
87 Ticks InstanceKlass::_class_unload_time;
88 #endif
89
90
91 #ifdef DTRACE_ENABLED
92
93
94 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
95 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
96 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
97 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
98 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
99 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
100 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
101 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
102 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
103 { \
104 char* data = NULL; \
105 int len = 0; \
106 Symbol* clss_name = name(); \
107 if (clss_name != NULL) { \
108 data = (char*)clss_name->bytes(); \
109 len = clss_name->utf8_length(); \
110 } \
111 HOTSPOT_CLASS_INITIALIZATION_##type( \
112 data, len, (void*)class_loader(), thread_type); \
113 }
114
115 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
116 { \
117 char* data = NULL; \
118 int len = 0; \
119 Symbol* clss_name = name(); \
120 if (clss_name != NULL) { \
121 data = (char*)clss_name->bytes(); \
122 len = clss_name->utf8_length(); \
123 } \
124 HOTSPOT_CLASS_INITIALIZATION_##type( \
125 data, len, (void*)class_loader(), thread_type, wait); \
126 }
127
128 #else // ndef DTRACE_ENABLED
129
130 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
131 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
132
133 #endif // ndef DTRACE_ENABLED
134
135 static inline bool is_class_loader(const Symbol* class_name,
136 const ClassFileParser& parser) {
137 assert(class_name != NULL, "invariant");
138
139 if (class_name == vmSymbols::java_lang_ClassLoader()) {
140 return true;
141 }
142
143 if (SystemDictionary::ClassLoader_klass_loaded()) {
144 const Klass* const super_klass = parser.super_klass();
145 if (super_klass != NULL) {
146 if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
147 return true;
148 }
149 }
150 }
151 return false;
152 }
153
154 // called to verify that k is a member of this nest
155 bool InstanceKlass::has_nest_member(InstanceKlass* k, TRAPS) const {
156 if (_nest_members == NULL || _nest_members == Universe::the_empty_short_array()) {
157 if (log_is_enabled(Trace, class, nestmates)) {
158 ResourceMark rm(THREAD);
159 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
160 k->external_name(), this->external_name());
161 }
162 return false;
163 }
164
165 if (log_is_enabled(Trace, class, nestmates)) {
166 ResourceMark rm(THREAD);
167 log_trace(class, nestmates)("Checking nest membership of %s in %s",
168 k->external_name(), this->external_name());
169 }
170
171 // Check names first and if they match then check actual klass. This avoids
172 // resolving anything unnecessarily.
173 for (int i = 0; i < _nest_members->length(); i++) {
174 int cp_index = _nest_members->at(i);
175 Symbol* name = _constants->klass_name_at(cp_index);
176 if (name == k->name()) {
177 log_trace(class, nestmates)("- Found it at nest_members[%d] => cp[%d]", i, cp_index);
178
179 // names match so check actual klass - this may trigger class loading if
180 // it doesn't match (but that should be impossible)
181 Klass* k2 = _constants->klass_at(cp_index, CHECK_false);
182 if (k2 == k) {
183 log_trace(class, nestmates)("- class is listed as a nest member");
184 return true;
185 } else {
186 // same name but different klass!
187 log_trace(class, nestmates)(" - klass comparison failed!");
188 // can't have different classes for the same name, so we're done
189 return false;
190 }
191 }
192 }
193 log_trace(class, nestmates)("- class is NOT a nest member!");
194 return false;
195 }
196
197 // Return nest-host class, resolving, validating and saving it if needed.
198 // In cases where this is called from a thread that can not do classloading
199 // (such as a native JIT thread) then we simply return NULL, which in turn
200 // causes the access check to return false. Such code will retry the access
201 // from a more suitable environment later.
202 InstanceKlass* InstanceKlass::nest_host(Symbol* validationException, TRAPS) {
203 InstanceKlass* nest_host_k = _nest_host;
204 if (nest_host_k == NULL) {
205 // need to resolve and save our nest-host class. This could be attempted
206 // concurrently but as the result is idempotent and we don't use the class
207 // then we do not need any synchronization beyond what is implicitly used
208 // during class loading.
209 if (_nest_host_index != 0) { // we have a real nest_host
210 // Before trying to resolve check if we're in a suitable context
211 if (!THREAD->can_call_java() && !_constants->tag_at(_nest_host_index).is_klass()) {
212 if (log_is_enabled(Trace, class, nestmates)) {
213 ResourceMark rm(THREAD);
214 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
215 this->external_name());
216 }
217 return NULL;
218 }
219
220 if (log_is_enabled(Trace, class, nestmates)) {
221 ResourceMark rm(THREAD);
222 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
223 this->external_name(),
224 _constants->klass_name_at(_nest_host_index)->as_C_string());
225 }
226
227 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
228 if (HAS_PENDING_EXCEPTION) {
229 Handle exc_h = Handle(THREAD, PENDING_EXCEPTION);
230 if (exc_h->is_a(SystemDictionary::NoClassDefFoundError_klass())) {
231 // throw a new CDNFE with the original as its cause, and a clear msg
232 ResourceMark rm(THREAD);
233 char buf[200];
234 CLEAR_PENDING_EXCEPTION;
235 jio_snprintf(buf, sizeof(buf),
236 "Unable to load nest-host class (%s) of %s",
237 _constants->klass_name_at(_nest_host_index)->as_C_string(),
238 this->external_name());
239 log_trace(class, nestmates)("%s - NoClassDefFoundError", buf);
240 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), buf, exc_h);
241 }
242 // All other exceptions pass through (OOME, StackOverflowError, LinkageErrors etc).
243 return NULL;
244 }
245
246 // A valid nest-host is an instance class in the current package that lists this
247 // class as a nest member. If any of these conditions are not met we post the
248 // requested exception type (if any) and return NULL
249
250 const char* error = NULL;
251
252 // JVMS 5.4.4 indicates package check comes first
253 if (is_same_class_package(k)) {
254
255 // Now check actual membership. We can't be a member if our "host" is
256 // not an instance class.
257 if (k->is_instance_klass()) {
258 nest_host_k = InstanceKlass::cast(k);
259
260 bool is_member = nest_host_k->has_nest_member(this, CHECK_NULL);
261 if (is_member) {
262 // save resolved nest-host value
263 _nest_host = nest_host_k;
264
265 if (log_is_enabled(Trace, class, nestmates)) {
266 ResourceMark rm(THREAD);
267 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
268 this->external_name(), k->external_name());
269 }
270 return nest_host_k;
271 }
272 }
273 error = "current type is not listed as a nest member";
274 } else {
275 error = "types are in different packages";
276 }
277
278 if (log_is_enabled(Trace, class, nestmates)) {
279 ResourceMark rm(THREAD);
280 log_trace(class, nestmates)("Type %s is not a nest member of resolved type %s: %s",
281 this->external_name(),
282 k->external_name(),
283 error);
284 }
285
286 if (validationException != NULL) {
287 ResourceMark rm(THREAD);
288 Exceptions::fthrow(THREAD_AND_LOCATION,
289 validationException,
290 "Type %s is not a nest member of %s: %s",
291 this->external_name(),
292 k->external_name(),
293 error
294 );
295 }
296 return NULL;
297 } else {
298 if (log_is_enabled(Trace, class, nestmates)) {
299 ResourceMark rm(THREAD);
300 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
301 this->external_name());
302 }
303 // save resolved nest-host value
304 return (_nest_host = this);
305 }
306 }
307 return nest_host_k;
308 }
309
310 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
311 // or we are k's nest_host - all of which is covered by comparing the two
312 // resolved_nest_hosts
313 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
314
315 assert(this != k, "this should be handled by higher-level code");
316
317 // Per JVMS 5.4.4 we first resolve and validate the current class, then
318 // the target class k. Resolution exceptions will be passed on by upper
319 // layers. IncompatibleClassChangeErrors from membership validation failures
320 // will also be passed through.
321
322 Symbol* icce = vmSymbols::java_lang_IncompatibleClassChangeError();
323 InstanceKlass* cur_host = nest_host(icce, CHECK_false);
324 if (cur_host == NULL) {
325 return false;
326 }
327
328 Klass* k_nest_host = k->nest_host(icce, CHECK_false);
329 if (k_nest_host == NULL) {
330 return false;
331 }
332
333 bool access = (cur_host == k_nest_host);
334
335 if (log_is_enabled(Trace, class, nestmates)) {
336 ResourceMark rm(THREAD);
337 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
338 this->external_name(),
339 access ? "" : "NOT ",
340 k->external_name());
341 }
342
343 return access;
344 }
345
346 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
347 const int size = InstanceKlass::size(parser.vtable_size(),
348 parser.itable_size(),
349 nonstatic_oop_map_size(parser.total_oop_map_count()),
350 parser.is_interface(),
351 parser.is_unsafe_anonymous(),
352 should_store_fingerprint(parser.is_unsafe_anonymous()));
353
354 const Symbol* const class_name = parser.class_name();
355 assert(class_name != NULL, "invariant");
356 ClassLoaderData* loader_data = parser.loader_data();
357 assert(loader_data != NULL, "invariant");
358
359 InstanceKlass* ik;
360
361 // Allocation
362 if (REF_NONE == parser.reference_type()) {
363 if (class_name == vmSymbols::java_lang_Class()) {
364 // mirror
365 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
366 }
367 else if (is_class_loader(class_name, parser)) {
368 // class loader
369 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
370 } else {
371 // normal
372 ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
373 }
374 } else {
375 // reference
376 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
377 }
378
379 // Check for pending exception before adding to the loader data and incrementing
380 // class count. Can get OOM here.
381 if (HAS_PENDING_EXCEPTION) {
382 return NULL;
383 }
384
385 return ik;
386 }
387
388
389 // copy method ordering from resource area to Metaspace
390 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
391 if (m != NULL) {
392 // allocate a new array and copy contents (memcpy?)
393 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
394 for (int i = 0; i < m->length(); i++) {
395 _method_ordering->at_put(i, m->at(i));
396 }
397 } else {
398 _method_ordering = Universe::the_empty_int_array();
399 }
400 }
401
402 // create a new array of vtable_indices for default methods
403 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
404 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
405 assert(default_vtable_indices() == NULL, "only create once");
406 set_default_vtable_indices(vtable_indices);
407 return vtable_indices;
408 }
409
410 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind, KlassID id) :
411 Klass(id),
412 _nest_members(NULL),
413 _nest_host_index(0),
414 _nest_host(NULL),
415 _static_field_size(parser.static_field_size()),
416 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
417 _itable_len(parser.itable_size()),
418 _reference_type(parser.reference_type()) {
419 set_vtable_length(parser.vtable_size());
420 set_kind(kind);
421 set_access_flags(parser.access_flags());
422 set_is_unsafe_anonymous(parser.is_unsafe_anonymous());
423 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
424 false));
425
426 assert(NULL == _methods, "underlying memory not zeroed?");
427 assert(is_instance_klass(), "is layout incorrect?");
428 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
429 }
430
431 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
432 Array<Method*>* methods) {
433 if (methods != NULL && methods != Universe::the_empty_method_array() &&
434 !methods->is_shared()) {
435 for (int i = 0; i < methods->length(); i++) {
436 Method* method = methods->at(i);
437 if (method == NULL) continue; // maybe null if error processing
438 // Only want to delete methods that are not executing for RedefineClasses.
439 // The previous version will point to them so they're not totally dangling
440 assert (!method->on_stack(), "shouldn't be called with methods on stack");
441 MetadataFactory::free_metadata(loader_data, method);
442 }
443 MetadataFactory::free_array<Method*>(loader_data, methods);
444 }
445 }
446
447 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
448 const Klass* super_klass,
449 Array<InstanceKlass*>* local_interfaces,
450 Array<InstanceKlass*>* transitive_interfaces) {
451 // Only deallocate transitive interfaces if not empty, same as super class
452 // or same as local interfaces. See code in parseClassFile.
453 Array<InstanceKlass*>* ti = transitive_interfaces;
454 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
455 // check that the interfaces don't come from super class
456 Array<InstanceKlass*>* sti = (super_klass == NULL) ? NULL :
457 InstanceKlass::cast(super_klass)->transitive_interfaces();
458 if (ti != sti && ti != NULL && !ti->is_shared()) {
459 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
460 }
461 }
462
463 // local interfaces can be empty
464 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
465 local_interfaces != NULL && !local_interfaces->is_shared()) {
466 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
467 }
468 }
469
470 // This function deallocates the metadata and C heap pointers that the
471 // InstanceKlass points to.
472 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
473
474 // Orphan the mirror first, CMS thinks it's still live.
475 if (java_mirror() != NULL) {
476 java_lang_Class::set_klass(java_mirror(), NULL);
477 }
478
479 // Also remove mirror from handles
480 loader_data->remove_handle(_java_mirror);
481
482 // Need to take this class off the class loader data list.
483 loader_data->remove_class(this);
484
485 // The array_klass for this class is created later, after error handling.
486 // For class redefinition, we keep the original class so this scratch class
487 // doesn't have an array class. Either way, assert that there is nothing
488 // to deallocate.
489 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
490
491 // Release C heap allocated data that this might point to, which includes
492 // reference counting symbol names.
493 release_C_heap_structures();
494
495 deallocate_methods(loader_data, methods());
496 set_methods(NULL);
497
498 if (method_ordering() != NULL &&
499 method_ordering() != Universe::the_empty_int_array() &&
500 !method_ordering()->is_shared()) {
501 MetadataFactory::free_array<int>(loader_data, method_ordering());
502 }
503 set_method_ordering(NULL);
504
505 // default methods can be empty
506 if (default_methods() != NULL &&
507 default_methods() != Universe::the_empty_method_array() &&
508 !default_methods()->is_shared()) {
509 MetadataFactory::free_array<Method*>(loader_data, default_methods());
510 }
511 // Do NOT deallocate the default methods, they are owned by superinterfaces.
512 set_default_methods(NULL);
513
514 // default methods vtable indices can be empty
515 if (default_vtable_indices() != NULL &&
516 !default_vtable_indices()->is_shared()) {
517 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
518 }
519 set_default_vtable_indices(NULL);
520
521
522 // This array is in Klass, but remove it with the InstanceKlass since
523 // this place would be the only caller and it can share memory with transitive
524 // interfaces.
525 if (secondary_supers() != NULL &&
526 secondary_supers() != Universe::the_empty_klass_array() &&
527 // see comments in compute_secondary_supers about the following cast
528 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
529 !secondary_supers()->is_shared()) {
530 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
531 }
532 set_secondary_supers(NULL);
533
534 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
535 set_transitive_interfaces(NULL);
536 set_local_interfaces(NULL);
537
538 if (fields() != NULL && !fields()->is_shared()) {
539 MetadataFactory::free_array<jushort>(loader_data, fields());
540 }
541 set_fields(NULL, 0);
542
543 // If a method from a redefined class is using this constant pool, don't
544 // delete it, yet. The new class's previous version will point to this.
545 if (constants() != NULL) {
546 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
547 if (!constants()->is_shared()) {
548 MetadataFactory::free_metadata(loader_data, constants());
549 }
550 // Delete any cached resolution errors for the constant pool
551 SystemDictionary::delete_resolution_error(constants());
552
553 set_constants(NULL);
554 }
555
556 if (inner_classes() != NULL &&
557 inner_classes() != Universe::the_empty_short_array() &&
558 !inner_classes()->is_shared()) {
559 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
560 }
561 set_inner_classes(NULL);
562
563 if (nest_members() != NULL &&
564 nest_members() != Universe::the_empty_short_array() &&
565 !nest_members()->is_shared()) {
566 MetadataFactory::free_array<jushort>(loader_data, nest_members());
567 }
568 set_nest_members(NULL);
569
570 // We should deallocate the Annotations instance if it's not in shared spaces.
571 if (annotations() != NULL && !annotations()->is_shared()) {
572 MetadataFactory::free_metadata(loader_data, annotations());
573 }
574 set_annotations(NULL);
575 }
576
577 bool InstanceKlass::should_be_initialized() const {
578 return !is_initialized();
579 }
580
581 klassItable InstanceKlass::itable() const {
582 return klassItable(const_cast<InstanceKlass*>(this));
583 }
584
585 void InstanceKlass::eager_initialize(Thread *thread) {
586 if (!EagerInitialization) return;
587
588 if (this->is_not_initialized()) {
589 // abort if the the class has a class initializer
590 if (this->class_initializer() != NULL) return;
591
592 // abort if it is java.lang.Object (initialization is handled in genesis)
593 Klass* super_klass = super();
594 if (super_klass == NULL) return;
595
596 // abort if the super class should be initialized
597 if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
598
599 // call body to expose the this pointer
600 eager_initialize_impl();
601 }
602 }
603
604 // JVMTI spec thinks there are signers and protection domain in the
605 // instanceKlass. These accessors pretend these fields are there.
606 // The hprof specification also thinks these fields are in InstanceKlass.
607 oop InstanceKlass::protection_domain() const {
608 // return the protection_domain from the mirror
609 return java_lang_Class::protection_domain(java_mirror());
610 }
611
612 // To remove these from requires an incompatible change and CCC request.
613 objArrayOop InstanceKlass::signers() const {
614 // return the signers from the mirror
615 return java_lang_Class::signers(java_mirror());
616 }
617
618 oop InstanceKlass::init_lock() const {
619 // return the init lock from the mirror
620 oop lock = java_lang_Class::init_lock(java_mirror());
621 // Prevent reordering with any access of initialization state
622 OrderAccess::loadload();
623 assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
624 "only fully initialized state can have a null lock");
625 return lock;
626 }
627
628 // Set the initialization lock to null so the object can be GC'ed. Any racing
629 // threads to get this lock will see a null lock and will not lock.
630 // That's okay because they all check for initialized state after getting
631 // the lock and return.
632 void InstanceKlass::fence_and_clear_init_lock() {
633 // make sure previous stores are all done, notably the init_state.
634 OrderAccess::storestore();
635 java_lang_Class::set_init_lock(java_mirror(), NULL);
636 assert(!is_not_initialized(), "class must be initialized now");
637 }
638
639 void InstanceKlass::eager_initialize_impl() {
640 EXCEPTION_MARK;
641 HandleMark hm(THREAD);
642 Handle h_init_lock(THREAD, init_lock());
643 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
644
645 // abort if someone beat us to the initialization
646 if (!is_not_initialized()) return; // note: not equivalent to is_initialized()
647
648 ClassState old_state = init_state();
649 link_class_impl(true, THREAD);
650 if (HAS_PENDING_EXCEPTION) {
651 CLEAR_PENDING_EXCEPTION;
652 // Abort if linking the class throws an exception.
653
654 // Use a test to avoid redundantly resetting the state if there's
655 // no change. Set_init_state() asserts that state changes make
656 // progress, whereas here we might just be spinning in place.
657 if (old_state != _init_state)
658 set_init_state(old_state);
659 } else {
660 // linking successfull, mark class as initialized
661 set_init_state(fully_initialized);
662 fence_and_clear_init_lock();
663 // trace
664 if (log_is_enabled(Info, class, init)) {
665 ResourceMark rm(THREAD);
666 log_info(class, init)("[Initialized %s without side effects]", external_name());
667 }
668 }
669 }
670
671
672 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
673 // process. The step comments refers to the procedure described in that section.
674 // Note: implementation moved to static method to expose the this pointer.
675 void InstanceKlass::initialize(TRAPS) {
676 if (this->should_be_initialized()) {
677 initialize_impl(CHECK);
678 // Note: at this point the class may be initialized
679 // OR it may be in the state of being initialized
680 // in case of recursive initialization!
681 } else {
682 assert(is_initialized(), "sanity check");
683 }
684 }
685
686
687 bool InstanceKlass::verify_code(bool throw_verifyerror, TRAPS) {
688 // 1) Verify the bytecodes
689 Verifier::Mode mode =
690 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
691 return Verifier::verify(this, mode, should_verify_class(), THREAD);
692 }
693
694
695 // Used exclusively by the shared spaces dump mechanism to prevent
696 // classes mapped into the shared regions in new VMs from appearing linked.
697
698 void InstanceKlass::unlink_class() {
699 assert(is_linked(), "must be linked");
700 _init_state = loaded;
701 }
702
703 void InstanceKlass::link_class(TRAPS) {
704 assert(is_loaded(), "must be loaded");
705 if (!is_linked()) {
706 link_class_impl(true, CHECK);
707 }
708 }
709
710 // Called to verify that a class can link during initialization, without
711 // throwing a VerifyError.
712 bool InstanceKlass::link_class_or_fail(TRAPS) {
713 assert(is_loaded(), "must be loaded");
714 if (!is_linked()) {
715 link_class_impl(false, CHECK_false);
716 }
717 return is_linked();
718 }
719
720 bool InstanceKlass::link_class_impl(bool throw_verifyerror, TRAPS) {
721 if (DumpSharedSpaces && is_in_error_state()) {
722 // This is for CDS dumping phase only -- we use the in_error_state to indicate that
723 // the class has failed verification. Throwing the NoClassDefFoundError here is just
724 // a convenient way to stop repeat attempts to verify the same (bad) class.
725 //
726 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
727 // if we are executing Java code. This is not a problem for CDS dumping phase since
728 // it doesn't execute any Java code.
729 ResourceMark rm(THREAD);
730 Exceptions::fthrow(THREAD_AND_LOCATION,
731 vmSymbols::java_lang_NoClassDefFoundError(),
732 "Class %s, or one of its supertypes, failed class initialization",
733 external_name());
734 return false;
735 }
736 // return if already verified
737 if (is_linked()) {
738 return true;
739 }
740
741 // Timing
742 // timer handles recursion
743 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
744 JavaThread* jt = (JavaThread*)THREAD;
745
746 // link super class before linking this class
747 Klass* super_klass = super();
748 if (super_klass != NULL) {
749 if (super_klass->is_interface()) { // check if super class is an interface
750 ResourceMark rm(THREAD);
751 Exceptions::fthrow(
752 THREAD_AND_LOCATION,
753 vmSymbols::java_lang_IncompatibleClassChangeError(),
754 "class %s has interface %s as super class",
755 external_name(),
756 super_klass->external_name()
757 );
758 return false;
759 }
760
761 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
762 ik_super->link_class_impl(throw_verifyerror, CHECK_false);
763 }
764
765 // link all interfaces implemented by this class before linking this class
766 Array<InstanceKlass*>* interfaces = local_interfaces();
767 int num_interfaces = interfaces->length();
768 for (int index = 0; index < num_interfaces; index++) {
769 InstanceKlass* interk = interfaces->at(index);
770 interk->link_class_impl(throw_verifyerror, CHECK_false);
771 }
772
773 // in case the class is linked in the process of linking its superclasses
774 if (is_linked()) {
775 return true;
776 }
777
778 // trace only the link time for this klass that includes
779 // the verification time
780 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
781 ClassLoader::perf_class_link_selftime(),
782 ClassLoader::perf_classes_linked(),
783 jt->get_thread_stat()->perf_recursion_counts_addr(),
784 jt->get_thread_stat()->perf_timers_addr(),
785 PerfClassTraceTime::CLASS_LINK);
786
787 // verification & rewriting
788 {
789 HandleMark hm(THREAD);
790 Handle h_init_lock(THREAD, init_lock());
791 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
792 // rewritten will have been set if loader constraint error found
793 // on an earlier link attempt
794 // don't verify or rewrite if already rewritten
795 //
796
797 if (!is_linked()) {
798 if (!is_rewritten()) {
799 {
800 bool verify_ok = verify_code(throw_verifyerror, THREAD);
801 if (!verify_ok) {
802 return false;
803 }
804 }
805
806 // Just in case a side-effect of verify linked this class already
807 // (which can sometimes happen since the verifier loads classes
808 // using custom class loaders, which are free to initialize things)
809 if (is_linked()) {
810 return true;
811 }
812
813 // also sets rewritten
814 rewrite_class(CHECK_false);
815 } else if (is_shared()) {
816 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
817 }
818
819 // relocate jsrs and link methods after they are all rewritten
820 link_methods(CHECK_false);
821
822 // Initialize the vtable and interface table after
823 // methods have been rewritten since rewrite may
824 // fabricate new Method*s.
825 // also does loader constraint checking
826 //
827 // initialize_vtable and initialize_itable need to be rerun for
828 // a shared class if the class is not loaded by the NULL classloader.
829 ClassLoaderData * loader_data = class_loader_data();
830 if (!(is_shared() &&
831 loader_data->is_the_null_class_loader_data())) {
832 vtable().initialize_vtable(true, CHECK_false);
833 itable().initialize_itable(true, CHECK_false);
834 }
835 #ifdef ASSERT
836 else {
837 vtable().verify(tty, true);
838 // In case itable verification is ever added.
839 // itable().verify(tty, true);
840 }
841 #endif
842 set_init_state(linked);
843 if (JvmtiExport::should_post_class_prepare()) {
844 Thread *thread = THREAD;
845 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
846 JvmtiExport::post_class_prepare((JavaThread *) thread, this);
847 }
848 }
849 }
850 return true;
851 }
852
853 // Rewrite the byte codes of all of the methods of a class.
854 // The rewriter must be called exactly once. Rewriting must happen after
855 // verification but before the first method of the class is executed.
856 void InstanceKlass::rewrite_class(TRAPS) {
857 assert(is_loaded(), "must be loaded");
858 if (is_rewritten()) {
859 assert(is_shared(), "rewriting an unshared class?");
860 return;
861 }
862 Rewriter::rewrite(this, CHECK);
863 set_rewritten();
864 }
865
866 // Now relocate and link method entry points after class is rewritten.
867 // This is outside is_rewritten flag. In case of an exception, it can be
868 // executed more than once.
869 void InstanceKlass::link_methods(TRAPS) {
870 int len = methods()->length();
871 for (int i = len-1; i >= 0; i--) {
872 methodHandle m(THREAD, methods()->at(i));
873
874 // Set up method entry points for compiler and interpreter .
875 m->link_method(m, CHECK);
876 }
877 }
878
879 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
880 void InstanceKlass::initialize_super_interfaces(TRAPS) {
881 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
882 for (int i = 0; i < local_interfaces()->length(); ++i) {
883 InstanceKlass* ik = local_interfaces()->at(i);
884
885 // Initialization is depth first search ie. we start with top of the inheritance tree
886 // has_nonstatic_concrete_methods drives searching superinterfaces since it
887 // means has_nonstatic_concrete_methods in its superinterface hierarchy
888 if (ik->has_nonstatic_concrete_methods()) {
889 ik->initialize_super_interfaces(CHECK);
890 }
891
892 // Only initialize() interfaces that "declare" concrete methods.
893 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
894 ik->initialize(CHECK);
895 }
896 }
897 }
898
899 void InstanceKlass::initialize_impl(TRAPS) {
900 HandleMark hm(THREAD);
901
902 // Make sure klass is linked (verified) before initialization
903 // A class could already be verified, since it has been reflected upon.
904 link_class(CHECK);
905
906 DTRACE_CLASSINIT_PROBE(required, -1);
907
908 bool wait = false;
909
910 // refer to the JVM book page 47 for description of steps
911 // Step 1
912 {
913 Handle h_init_lock(THREAD, init_lock());
914 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
915
916 Thread *self = THREAD; // it's passed the current thread
917
918 // Step 2
919 // If we were to use wait() instead of waitInterruptibly() then
920 // we might end up throwing IE from link/symbol resolution sites
921 // that aren't expected to throw. This would wreak havoc. See 6320309.
922 while(is_being_initialized() && !is_reentrant_initialization(self)) {
923 wait = true;
924 ol.waitUninterruptibly(CHECK);
925 }
926
927 // Step 3
928 if (is_being_initialized() && is_reentrant_initialization(self)) {
929 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
930 return;
931 }
932
933 // Step 4
934 if (is_initialized()) {
935 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
936 return;
937 }
938
939 // Step 5
940 if (is_in_error_state()) {
941 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
942 ResourceMark rm(THREAD);
943 const char* desc = "Could not initialize class ";
944 const char* className = external_name();
945 size_t msglen = strlen(desc) + strlen(className) + 1;
946 char* message = NEW_RESOURCE_ARRAY(char, msglen);
947 if (NULL == message) {
948 // Out of memory: can't create detailed error message
949 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
950 } else {
951 jio_snprintf(message, msglen, "%s%s", desc, className);
952 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
953 }
954 }
955
956 // Step 6
957 set_init_state(being_initialized);
958 set_init_thread(self);
959 }
960
961 // Step 7
962 // Next, if C is a class rather than an interface, initialize it's super class and super
963 // interfaces.
964 if (!is_interface()) {
965 Klass* super_klass = super();
966 if (super_klass != NULL && super_klass->should_be_initialized()) {
967 super_klass->initialize(THREAD);
968 }
969 // If C implements any interface that declares a non-static, concrete method,
970 // the initialization of C triggers initialization of its super interfaces.
971 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
972 // having a superinterface that declares, non-static, concrete methods
973 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
974 initialize_super_interfaces(THREAD);
975 }
976
977 // If any exceptions, complete abruptly, throwing the same exception as above.
978 if (HAS_PENDING_EXCEPTION) {
979 Handle e(THREAD, PENDING_EXCEPTION);
980 CLEAR_PENDING_EXCEPTION;
981 {
982 EXCEPTION_MARK;
983 // Locks object, set state, and notify all waiting threads
984 set_initialization_state_and_notify(initialization_error, THREAD);
985 CLEAR_PENDING_EXCEPTION;
986 }
987 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
988 THROW_OOP(e());
989 }
990 }
991
992
993 // Look for aot compiled methods for this klass, including class initializer.
994 AOTLoader::load_for_klass(this, THREAD);
995
996 // Step 8
997 {
998 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
999 JavaThread* jt = (JavaThread*)THREAD;
1000 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1001 // Timer includes any side effects of class initialization (resolution,
1002 // etc), but not recursive entry into call_class_initializer().
1003 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1004 ClassLoader::perf_class_init_selftime(),
1005 ClassLoader::perf_classes_inited(),
1006 jt->get_thread_stat()->perf_recursion_counts_addr(),
1007 jt->get_thread_stat()->perf_timers_addr(),
1008 PerfClassTraceTime::CLASS_CLINIT);
1009 call_class_initializer(THREAD);
1010 }
1011
1012 // Step 9
1013 if (!HAS_PENDING_EXCEPTION) {
1014 set_initialization_state_and_notify(fully_initialized, CHECK);
1015 {
1016 debug_only(vtable().verify(tty, true);)
1017 }
1018 }
1019 else {
1020 // Step 10 and 11
1021 Handle e(THREAD, PENDING_EXCEPTION);
1022 CLEAR_PENDING_EXCEPTION;
1023 // JVMTI has already reported the pending exception
1024 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1025 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
1026 {
1027 EXCEPTION_MARK;
1028 set_initialization_state_and_notify(initialization_error, THREAD);
1029 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1030 // JVMTI has already reported the pending exception
1031 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1032 JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
1033 }
1034 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1035 if (e->is_a(SystemDictionary::Error_klass())) {
1036 THROW_OOP(e());
1037 } else {
1038 JavaCallArguments args(e);
1039 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1040 vmSymbols::throwable_void_signature(),
1041 &args);
1042 }
1043 }
1044 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1045 }
1046
1047
1048 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1049 Handle h_init_lock(THREAD, init_lock());
1050 if (h_init_lock() != NULL) {
1051 ObjectLocker ol(h_init_lock, THREAD);
1052 set_init_state(state);
1053 fence_and_clear_init_lock();
1054 ol.notify_all(CHECK);
1055 } else {
1056 assert(h_init_lock() != NULL, "The initialization state should never be set twice");
1057 set_init_state(state);
1058 }
1059 }
1060
1061 Klass* InstanceKlass::implementor() const {
1062 assert_locked_or_safepoint(Compile_lock);
1063 Klass** k = adr_implementor();
1064 if (k == NULL) {
1065 return NULL;
1066 } else {
1067 return *k;
1068 }
1069 }
1070
1071 void InstanceKlass::set_implementor(Klass* k) {
1072 assert_lock_strong(Compile_lock);
1073 assert(is_interface(), "not interface");
1074 Klass** addr = adr_implementor();
1075 assert(addr != NULL, "null addr");
1076 if (addr != NULL) {
1077 *addr = k;
1078 }
1079 }
1080
1081 int InstanceKlass::nof_implementors() const {
1082 assert_lock_strong(Compile_lock);
1083 Klass* k = implementor();
1084 if (k == NULL) {
1085 return 0;
1086 } else if (k != this) {
1087 return 1;
1088 } else {
1089 return 2;
1090 }
1091 }
1092
1093 // The embedded _implementor field can only record one implementor.
1094 // When there are more than one implementors, the _implementor field
1095 // is set to the interface Klass* itself. Following are the possible
1096 // values for the _implementor field:
1097 // NULL - no implementor
1098 // implementor Klass* - one implementor
1099 // self - more than one implementor
1100 //
1101 // The _implementor field only exists for interfaces.
1102 void InstanceKlass::add_implementor(Klass* k) {
1103 assert_lock_strong(Compile_lock);
1104 assert(is_interface(), "not interface");
1105 // Filter out my subinterfaces.
1106 // (Note: Interfaces are never on the subklass list.)
1107 if (InstanceKlass::cast(k)->is_interface()) return;
1108
1109 // Filter out subclasses whose supers already implement me.
1110 // (Note: CHA must walk subclasses of direct implementors
1111 // in order to locate indirect implementors.)
1112 Klass* sk = k->super();
1113 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
1114 // We only need to check one immediate superclass, since the
1115 // implements_interface query looks at transitive_interfaces.
1116 // Any supers of the super have the same (or fewer) transitive_interfaces.
1117 return;
1118
1119 Klass* ik = implementor();
1120 if (ik == NULL) {
1121 set_implementor(k);
1122 } else if (ik != this) {
1123 // There is already an implementor. Use itself as an indicator of
1124 // more than one implementors.
1125 set_implementor(this);
1126 }
1127
1128 // The implementor also implements the transitive_interfaces
1129 for (int index = 0; index < local_interfaces()->length(); index++) {
1130 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
1131 }
1132 }
1133
1134 void InstanceKlass::init_implementor() {
1135 if (is_interface()) {
1136 set_implementor(NULL);
1137 }
1138 }
1139
1140
1141 void InstanceKlass::process_interfaces(Thread *thread) {
1142 // link this class into the implementors list of every interface it implements
1143 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1144 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1145 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
1146 assert(interf->is_interface(), "expected interface");
1147 interf->add_implementor(this);
1148 }
1149 }
1150
1151 bool InstanceKlass::can_be_primary_super_slow() const {
1152 if (is_interface())
1153 return false;
1154 else
1155 return Klass::can_be_primary_super_slow();
1156 }
1157
1158 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1159 Array<InstanceKlass*>* transitive_interfaces) {
1160 // The secondaries are the implemented interfaces.
1161 Array<InstanceKlass*>* interfaces = transitive_interfaces;
1162 int num_secondaries = num_extra_slots + interfaces->length();
1163 if (num_secondaries == 0) {
1164 // Must share this for correct bootstrapping!
1165 set_secondary_supers(Universe::the_empty_klass_array());
1166 return NULL;
1167 } else if (num_extra_slots == 0) {
1168 // The secondary super list is exactly the same as the transitive interfaces, so
1169 // let's use it instead of making a copy.
1170 // Redefine classes has to be careful not to delete this!
1171 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1172 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1173 set_secondary_supers((Array<Klass*>*)(address)interfaces);
1174 return NULL;
1175 } else {
1176 // Copy transitive interfaces to a temporary growable array to be constructed
1177 // into the secondary super list with extra slots.
1178 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1179 for (int i = 0; i < interfaces->length(); i++) {
1180 secondaries->push(interfaces->at(i));
1181 }
1182 return secondaries;
1183 }
1184 }
1185
1186 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
1187 if (k->is_interface()) {
1188 return implements_interface(k);
1189 } else {
1190 return Klass::compute_is_subtype_of(k);
1191 }
1192 }
1193
1194 bool InstanceKlass::implements_interface(Klass* k) const {
1195 if (this == k) return true;
1196 assert(k->is_interface(), "should be an interface class");
1197 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1198 if (transitive_interfaces()->at(i) == k) {
1199 return true;
1200 }
1201 }
1202 return false;
1203 }
1204
1205 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1206 // Verify direct super interface
1207 if (this == k) return true;
1208 assert(k->is_interface(), "should be an interface class");
1209 for (int i = 0; i < local_interfaces()->length(); i++) {
1210 if (local_interfaces()->at(i) == k) {
1211 return true;
1212 }
1213 }
1214 return false;
1215 }
1216
1217 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1218 if (length < 0) {
1219 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length));
1220 }
1221 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
1222 report_java_out_of_memory("Requested array size exceeds VM limit");
1223 JvmtiExport::post_array_size_exhausted();
1224 THROW_OOP_0(Universe::out_of_memory_error_array_size());
1225 }
1226 int size = objArrayOopDesc::object_size(length);
1227 Klass* ak = array_klass(n, CHECK_NULL);
1228 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1229 /* do_zero */ true, CHECK_NULL);
1230 return o;
1231 }
1232
1233 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1234 if (TraceFinalizerRegistration) {
1235 tty->print("Registered ");
1236 i->print_value_on(tty);
1237 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1238 }
1239 instanceHandle h_i(THREAD, i);
1240 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1241 JavaValue result(T_VOID);
1242 JavaCallArguments args(h_i);
1243 methodHandle mh (THREAD, Universe::finalizer_register_method());
1244 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1245 return h_i();
1246 }
1247
1248 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1249 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1250 int size = size_helper(); // Query before forming handle.
1251
1252 instanceOop i;
1253
1254 i = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1255 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1256 i = register_finalizer(i, CHECK_NULL);
1257 }
1258 return i;
1259 }
1260
1261 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1262 return instanceHandle(THREAD, allocate_instance(THREAD));
1263 }
1264
1265 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1266 if (is_interface() || is_abstract()) {
1267 ResourceMark rm(THREAD);
1268 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1269 : vmSymbols::java_lang_InstantiationException(), external_name());
1270 }
1271 if (this == SystemDictionary::Class_klass()) {
1272 ResourceMark rm(THREAD);
1273 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1274 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1275 }
1276 }
1277
1278 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1279 // Need load-acquire for lock-free read
1280 if (array_klasses_acquire() == NULL) {
1281 if (or_null) return NULL;
1282
1283 ResourceMark rm;
1284 JavaThread *jt = (JavaThread *)THREAD;
1285 {
1286 // Atomic creation of array_klasses
1287 MutexLocker mc(Compile_lock, THREAD); // for vtables
1288 MutexLocker ma(MultiArray_lock, THREAD);
1289
1290 // Check if update has already taken place
1291 if (array_klasses() == NULL) {
1292 Klass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1293 // use 'release' to pair with lock-free load
1294 release_set_array_klasses(k);
1295 }
1296 }
1297 }
1298 // _this will always be set at this point
1299 ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1300 if (or_null) {
1301 return oak->array_klass_or_null(n);
1302 }
1303 return oak->array_klass(n, THREAD);
1304 }
1305
1306 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1307 return array_klass_impl(or_null, 1, THREAD);
1308 }
1309
1310 static int call_class_initializer_counter = 0; // for debugging
1311
1312 Method* InstanceKlass::class_initializer() const {
1313 Method* clinit = find_method(
1314 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1315 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1316 return clinit;
1317 }
1318 return NULL;
1319 }
1320
1321 void InstanceKlass::call_class_initializer(TRAPS) {
1322 if (ReplayCompiles &&
1323 (ReplaySuppressInitializers == 1 ||
1324 (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1325 // Hide the existence of the initializer for the purpose of replaying the compile
1326 return;
1327 }
1328
1329 methodHandle h_method(THREAD, class_initializer());
1330 assert(!is_initialized(), "we cannot initialize twice");
1331 LogTarget(Info, class, init) lt;
1332 if (lt.is_enabled()) {
1333 ResourceMark rm;
1334 LogStream ls(lt);
1335 ls.print("%d Initializing ", call_class_initializer_counter++);
1336 name()->print_value_on(&ls);
1337 ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1338 }
1339 if (h_method() != NULL) {
1340 JavaCallArguments args; // No arguments
1341 JavaValue result(T_VOID);
1342 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1343 }
1344 }
1345
1346
1347 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1348 InterpreterOopMap* entry_for) {
1349 // Lazily create the _oop_map_cache at first request
1350 // Lock-free access requires load_acquire.
1351 OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache);
1352 if (oop_map_cache == NULL) {
1353 MutexLocker x(OopMapCacheAlloc_lock);
1354 // Check if _oop_map_cache was allocated while we were waiting for this lock
1355 if ((oop_map_cache = _oop_map_cache) == NULL) {
1356 oop_map_cache = new OopMapCache();
1357 // Ensure _oop_map_cache is stable, since it is examined without a lock
1358 OrderAccess::release_store(&_oop_map_cache, oop_map_cache);
1359 }
1360 }
1361 // _oop_map_cache is constant after init; lookup below does its own locking.
1362 oop_map_cache->lookup(method, bci, entry_for);
1363 }
1364
1365
1366 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1367 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1368 Symbol* f_name = fs.name();
1369 Symbol* f_sig = fs.signature();
1370 if (f_name == name && f_sig == sig) {
1371 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1372 return true;
1373 }
1374 }
1375 return false;
1376 }
1377
1378
1379 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1380 const int n = local_interfaces()->length();
1381 for (int i = 0; i < n; i++) {
1382 Klass* intf1 = local_interfaces()->at(i);
1383 assert(intf1->is_interface(), "just checking type");
1384 // search for field in current interface
1385 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1386 assert(fd->is_static(), "interface field must be static");
1387 return intf1;
1388 }
1389 // search for field in direct superinterfaces
1390 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1391 if (intf2 != NULL) return intf2;
1392 }
1393 // otherwise field lookup fails
1394 return NULL;
1395 }
1396
1397
1398 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1399 // search order according to newest JVM spec (5.4.3.2, p.167).
1400 // 1) search for field in current klass
1401 if (find_local_field(name, sig, fd)) {
1402 return const_cast<InstanceKlass*>(this);
1403 }
1404 // 2) search for field recursively in direct superinterfaces
1405 { Klass* intf = find_interface_field(name, sig, fd);
1406 if (intf != NULL) return intf;
1407 }
1408 // 3) apply field lookup recursively if superclass exists
1409 { Klass* supr = super();
1410 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1411 }
1412 // 4) otherwise field lookup fails
1413 return NULL;
1414 }
1415
1416
1417 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1418 // search order according to newest JVM spec (5.4.3.2, p.167).
1419 // 1) search for field in current klass
1420 if (find_local_field(name, sig, fd)) {
1421 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1422 }
1423 // 2) search for field recursively in direct superinterfaces
1424 if (is_static) {
1425 Klass* intf = find_interface_field(name, sig, fd);
1426 if (intf != NULL) return intf;
1427 }
1428 // 3) apply field lookup recursively if superclass exists
1429 { Klass* supr = super();
1430 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1431 }
1432 // 4) otherwise field lookup fails
1433 return NULL;
1434 }
1435
1436
1437 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1438 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1439 if (fs.offset() == offset) {
1440 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1441 if (fd->is_static() == is_static) return true;
1442 }
1443 }
1444 return false;
1445 }
1446
1447
1448 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1449 Klass* klass = const_cast<InstanceKlass*>(this);
1450 while (klass != NULL) {
1451 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1452 return true;
1453 }
1454 klass = klass->super();
1455 }
1456 return false;
1457 }
1458
1459
1460 void InstanceKlass::methods_do(void f(Method* method)) {
1461 // Methods aren't stable until they are loaded. This can be read outside
1462 // a lock through the ClassLoaderData for profiling
1463 if (!is_loaded()) {
1464 return;
1465 }
1466
1467 int len = methods()->length();
1468 for (int index = 0; index < len; index++) {
1469 Method* m = methods()->at(index);
1470 assert(m->is_method(), "must be method");
1471 f(m);
1472 }
1473 }
1474
1475
1476 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1477 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1478 if (fs.access_flags().is_static()) {
1479 fieldDescriptor& fd = fs.field_descriptor();
1480 cl->do_field(&fd);
1481 }
1482 }
1483 }
1484
1485
1486 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1487 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1488 if (fs.access_flags().is_static()) {
1489 fieldDescriptor& fd = fs.field_descriptor();
1490 f(&fd, mirror, CHECK);
1491 }
1492 }
1493 }
1494
1495
1496 static int compare_fields_by_offset(int* a, int* b) {
1497 return a[0] - b[0];
1498 }
1499
1500 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1501 InstanceKlass* super = superklass();
1502 if (super != NULL) {
1503 super->do_nonstatic_fields(cl);
1504 }
1505 fieldDescriptor fd;
1506 int length = java_fields_count();
1507 // In DebugInfo nonstatic fields are sorted by offset.
1508 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1509 int j = 0;
1510 for (int i = 0; i < length; i += 1) {
1511 fd.reinitialize(this, i);
1512 if (!fd.is_static()) {
1513 fields_sorted[j + 0] = fd.offset();
1514 fields_sorted[j + 1] = i;
1515 j += 2;
1516 }
1517 }
1518 if (j > 0) {
1519 length = j;
1520 // _sort_Fn is defined in growableArray.hpp.
1521 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1522 for (int i = 0; i < length; i += 2) {
1523 fd.reinitialize(this, fields_sorted[i + 1]);
1524 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1525 cl->do_field(&fd);
1526 }
1527 }
1528 FREE_C_HEAP_ARRAY(int, fields_sorted);
1529 }
1530
1531
1532 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1533 if (array_klasses() != NULL)
1534 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1535 }
1536
1537 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1538 if (array_klasses() != NULL)
1539 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1540 }
1541
1542 #ifdef ASSERT
1543 static int linear_search(const Array<Method*>* methods,
1544 const Symbol* name,
1545 const Symbol* signature) {
1546 const int len = methods->length();
1547 for (int index = 0; index < len; index++) {
1548 const Method* const m = methods->at(index);
1549 assert(m->is_method(), "must be method");
1550 if (m->signature() == signature && m->name() == name) {
1551 return index;
1552 }
1553 }
1554 return -1;
1555 }
1556 #endif
1557
1558 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1559 int len = methods->length();
1560 // methods are sorted, so do binary search
1561 int l = 0;
1562 int h = len - 1;
1563 while (l <= h) {
1564 int mid = (l + h) >> 1;
1565 Method* m = methods->at(mid);
1566 assert(m->is_method(), "must be method");
1567 int res = m->name()->fast_compare(name);
1568 if (res == 0) {
1569 return mid;
1570 } else if (res < 0) {
1571 l = mid + 1;
1572 } else {
1573 h = mid - 1;
1574 }
1575 }
1576 return -1;
1577 }
1578
1579 // find_method looks up the name/signature in the local methods array
1580 Method* InstanceKlass::find_method(const Symbol* name,
1581 const Symbol* signature) const {
1582 return find_method_impl(name, signature, find_overpass, find_static, find_private);
1583 }
1584
1585 Method* InstanceKlass::find_method_impl(const Symbol* name,
1586 const Symbol* signature,
1587 OverpassLookupMode overpass_mode,
1588 StaticLookupMode static_mode,
1589 PrivateLookupMode private_mode) const {
1590 return InstanceKlass::find_method_impl(methods(),
1591 name,
1592 signature,
1593 overpass_mode,
1594 static_mode,
1595 private_mode);
1596 }
1597
1598 // find_instance_method looks up the name/signature in the local methods array
1599 // and skips over static methods
1600 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1601 const Symbol* name,
1602 const Symbol* signature,
1603 PrivateLookupMode private_mode) {
1604 Method* const meth = InstanceKlass::find_method_impl(methods,
1605 name,
1606 signature,
1607 find_overpass,
1608 skip_static,
1609 private_mode);
1610 assert(((meth == NULL) || !meth->is_static()),
1611 "find_instance_method should have skipped statics");
1612 return meth;
1613 }
1614
1615 // find_instance_method looks up the name/signature in the local methods array
1616 // and skips over static methods
1617 Method* InstanceKlass::find_instance_method(const Symbol* name,
1618 const Symbol* signature,
1619 PrivateLookupMode private_mode) const {
1620 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1621 }
1622
1623 // Find looks up the name/signature in the local methods array
1624 // and filters on the overpass, static and private flags
1625 // This returns the first one found
1626 // note that the local methods array can have up to one overpass, one static
1627 // and one instance (private or not) with the same name/signature
1628 Method* InstanceKlass::find_local_method(const Symbol* name,
1629 const Symbol* signature,
1630 OverpassLookupMode overpass_mode,
1631 StaticLookupMode static_mode,
1632 PrivateLookupMode private_mode) const {
1633 return InstanceKlass::find_method_impl(methods(),
1634 name,
1635 signature,
1636 overpass_mode,
1637 static_mode,
1638 private_mode);
1639 }
1640
1641 // Find looks up the name/signature in the local methods array
1642 // and filters on the overpass, static and private flags
1643 // This returns the first one found
1644 // note that the local methods array can have up to one overpass, one static
1645 // and one instance (private or not) with the same name/signature
1646 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1647 const Symbol* name,
1648 const Symbol* signature,
1649 OverpassLookupMode overpass_mode,
1650 StaticLookupMode static_mode,
1651 PrivateLookupMode private_mode) {
1652 return InstanceKlass::find_method_impl(methods,
1653 name,
1654 signature,
1655 overpass_mode,
1656 static_mode,
1657 private_mode);
1658 }
1659
1660 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1661 const Symbol* name,
1662 const Symbol* signature) {
1663 return InstanceKlass::find_method_impl(methods,
1664 name,
1665 signature,
1666 find_overpass,
1667 find_static,
1668 find_private);
1669 }
1670
1671 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1672 const Symbol* name,
1673 const Symbol* signature,
1674 OverpassLookupMode overpass_mode,
1675 StaticLookupMode static_mode,
1676 PrivateLookupMode private_mode) {
1677 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1678 return hit >= 0 ? methods->at(hit): NULL;
1679 }
1680
1681 // true if method matches signature and conforms to skipping_X conditions.
1682 static bool method_matches(const Method* m,
1683 const Symbol* signature,
1684 bool skipping_overpass,
1685 bool skipping_static,
1686 bool skipping_private) {
1687 return ((m->signature() == signature) &&
1688 (!skipping_overpass || !m->is_overpass()) &&
1689 (!skipping_static || !m->is_static()) &&
1690 (!skipping_private || !m->is_private()));
1691 }
1692
1693 // Used directly for default_methods to find the index into the
1694 // default_vtable_indices, and indirectly by find_method
1695 // find_method_index looks in the local methods array to return the index
1696 // of the matching name/signature. If, overpass methods are being ignored,
1697 // the search continues to find a potential non-overpass match. This capability
1698 // is important during method resolution to prefer a static method, for example,
1699 // over an overpass method.
1700 // There is the possibility in any _method's array to have the same name/signature
1701 // for a static method, an overpass method and a local instance method
1702 // To correctly catch a given method, the search criteria may need
1703 // to explicitly skip the other two. For local instance methods, it
1704 // is often necessary to skip private methods
1705 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1706 const Symbol* name,
1707 const Symbol* signature,
1708 OverpassLookupMode overpass_mode,
1709 StaticLookupMode static_mode,
1710 PrivateLookupMode private_mode) {
1711 const bool skipping_overpass = (overpass_mode == skip_overpass);
1712 const bool skipping_static = (static_mode == skip_static);
1713 const bool skipping_private = (private_mode == skip_private);
1714 const int hit = binary_search(methods, name);
1715 if (hit != -1) {
1716 const Method* const m = methods->at(hit);
1717
1718 // Do linear search to find matching signature. First, quick check
1719 // for common case, ignoring overpasses if requested.
1720 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1721 return hit;
1722 }
1723
1724 // search downwards through overloaded methods
1725 int i;
1726 for (i = hit - 1; i >= 0; --i) {
1727 const Method* const m = methods->at(i);
1728 assert(m->is_method(), "must be method");
1729 if (m->name() != name) {
1730 break;
1731 }
1732 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1733 return i;
1734 }
1735 }
1736 // search upwards
1737 for (i = hit + 1; i < methods->length(); ++i) {
1738 const Method* const m = methods->at(i);
1739 assert(m->is_method(), "must be method");
1740 if (m->name() != name) {
1741 break;
1742 }
1743 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1744 return i;
1745 }
1746 }
1747 // not found
1748 #ifdef ASSERT
1749 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1750 linear_search(methods, name, signature);
1751 assert(-1 == index, "binary search should have found entry %d", index);
1752 #endif
1753 }
1754 return -1;
1755 }
1756
1757 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1758 return find_method_by_name(methods(), name, end);
1759 }
1760
1761 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1762 const Symbol* name,
1763 int* end_ptr) {
1764 assert(end_ptr != NULL, "just checking");
1765 int start = binary_search(methods, name);
1766 int end = start + 1;
1767 if (start != -1) {
1768 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1769 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1770 *end_ptr = end;
1771 return start;
1772 }
1773 return -1;
1774 }
1775
1776 // uncached_lookup_method searches both the local class methods array and all
1777 // superclasses methods arrays, skipping any overpass methods in superclasses,
1778 // and possibly skipping private methods.
1779 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1780 const Symbol* signature,
1781 OverpassLookupMode overpass_mode,
1782 PrivateLookupMode private_mode) const {
1783 OverpassLookupMode overpass_local_mode = overpass_mode;
1784 const Klass* klass = this;
1785 while (klass != NULL) {
1786 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1787 signature,
1788 overpass_local_mode,
1789 find_static,
1790 private_mode);
1791 if (method != NULL) {
1792 return method;
1793 }
1794 klass = klass->super();
1795 overpass_local_mode = skip_overpass; // Always ignore overpass methods in superclasses
1796 }
1797 return NULL;
1798 }
1799
1800 #ifdef ASSERT
1801 // search through class hierarchy and return true if this class or
1802 // one of the superclasses was redefined
1803 bool InstanceKlass::has_redefined_this_or_super() const {
1804 const Klass* klass = this;
1805 while (klass != NULL) {
1806 if (InstanceKlass::cast(klass)->has_been_redefined()) {
1807 return true;
1808 }
1809 klass = klass->super();
1810 }
1811 return false;
1812 }
1813 #endif
1814
1815 // lookup a method in the default methods list then in all transitive interfaces
1816 // Do NOT return private or static methods
1817 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1818 Symbol* signature) const {
1819 Method* m = NULL;
1820 if (default_methods() != NULL) {
1821 m = find_method(default_methods(), name, signature);
1822 }
1823 // Look up interfaces
1824 if (m == NULL) {
1825 m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1826 }
1827 return m;
1828 }
1829
1830 // lookup a method in all the interfaces that this class implements
1831 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1832 // They should only be found in the initial InterfaceMethodRef
1833 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1834 Symbol* signature,
1835 DefaultsLookupMode defaults_mode) const {
1836 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1837 int num_ifs = all_ifs->length();
1838 InstanceKlass *ik = NULL;
1839 for (int i = 0; i < num_ifs; i++) {
1840 ik = all_ifs->at(i);
1841 Method* m = ik->lookup_method(name, signature);
1842 if (m != NULL && m->is_public() && !m->is_static() &&
1843 ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1844 return m;
1845 }
1846 }
1847 return NULL;
1848 }
1849
1850 /* jni_id_for_impl for jfieldIds only */
1851 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1852 MutexLocker ml(JfieldIdCreation_lock);
1853 // Retry lookup after we got the lock
1854 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1855 if (probe == NULL) {
1856 // Slow case, allocate new static field identifier
1857 probe = new JNIid(this, offset, jni_ids());
1858 set_jni_ids(probe);
1859 }
1860 return probe;
1861 }
1862
1863
1864 /* jni_id_for for jfieldIds only */
1865 JNIid* InstanceKlass::jni_id_for(int offset) {
1866 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1867 if (probe == NULL) {
1868 probe = jni_id_for_impl(offset);
1869 }
1870 return probe;
1871 }
1872
1873 u2 InstanceKlass::enclosing_method_data(int offset) const {
1874 const Array<jushort>* const inner_class_list = inner_classes();
1875 if (inner_class_list == NULL) {
1876 return 0;
1877 }
1878 const int length = inner_class_list->length();
1879 if (length % inner_class_next_offset == 0) {
1880 return 0;
1881 }
1882 const int index = length - enclosing_method_attribute_size;
1883 assert(offset < enclosing_method_attribute_size, "invalid offset");
1884 return inner_class_list->at(index + offset);
1885 }
1886
1887 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1888 u2 method_index) {
1889 Array<jushort>* inner_class_list = inner_classes();
1890 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1891 int length = inner_class_list->length();
1892 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1893 int index = length - enclosing_method_attribute_size;
1894 inner_class_list->at_put(
1895 index + enclosing_method_class_index_offset, class_index);
1896 inner_class_list->at_put(
1897 index + enclosing_method_method_index_offset, method_index);
1898 }
1899 }
1900
1901 // Lookup or create a jmethodID.
1902 // This code is called by the VMThread and JavaThreads so the
1903 // locking has to be done very carefully to avoid deadlocks
1904 // and/or other cache consistency problems.
1905 //
1906 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
1907 size_t idnum = (size_t)method_h->method_idnum();
1908 jmethodID* jmeths = methods_jmethod_ids_acquire();
1909 size_t length = 0;
1910 jmethodID id = NULL;
1911
1912 // We use a double-check locking idiom here because this cache is
1913 // performance sensitive. In the normal system, this cache only
1914 // transitions from NULL to non-NULL which is safe because we use
1915 // release_set_methods_jmethod_ids() to advertise the new cache.
1916 // A partially constructed cache should never be seen by a racing
1917 // thread. We also use release_store() to save a new jmethodID
1918 // in the cache so a partially constructed jmethodID should never be
1919 // seen either. Cache reads of existing jmethodIDs proceed without a
1920 // lock, but cache writes of a new jmethodID requires uniqueness and
1921 // creation of the cache itself requires no leaks so a lock is
1922 // generally acquired in those two cases.
1923 //
1924 // If the RedefineClasses() API has been used, then this cache can
1925 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1926 // Cache creation requires no leaks and we require safety between all
1927 // cache accesses and freeing of the old cache so a lock is generally
1928 // acquired when the RedefineClasses() API has been used.
1929
1930 if (jmeths != NULL) {
1931 // the cache already exists
1932 if (!idnum_can_increment()) {
1933 // the cache can't grow so we can just get the current values
1934 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1935 } else {
1936 // cache can grow so we have to be more careful
1937 if (Threads::number_of_threads() == 0 ||
1938 SafepointSynchronize::is_at_safepoint()) {
1939 // we're single threaded or at a safepoint - no locking needed
1940 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1941 } else {
1942 MutexLocker ml(JmethodIdCreation_lock);
1943 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1944 }
1945 }
1946 }
1947 // implied else:
1948 // we need to allocate a cache so default length and id values are good
1949
1950 if (jmeths == NULL || // no cache yet
1951 length <= idnum || // cache is too short
1952 id == NULL) { // cache doesn't contain entry
1953
1954 // This function can be called by the VMThread so we have to do all
1955 // things that might block on a safepoint before grabbing the lock.
1956 // Otherwise, we can deadlock with the VMThread or have a cache
1957 // consistency issue. These vars keep track of what we might have
1958 // to free after the lock is dropped.
1959 jmethodID to_dealloc_id = NULL;
1960 jmethodID* to_dealloc_jmeths = NULL;
1961
1962 // may not allocate new_jmeths or use it if we allocate it
1963 jmethodID* new_jmeths = NULL;
1964 if (length <= idnum) {
1965 // allocate a new cache that might be used
1966 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1967 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1968 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1969 // cache size is stored in element[0], other elements offset by one
1970 new_jmeths[0] = (jmethodID)size;
1971 }
1972
1973 // allocate a new jmethodID that might be used
1974 jmethodID new_id = NULL;
1975 if (method_h->is_old() && !method_h->is_obsolete()) {
1976 // The method passed in is old (but not obsolete), we need to use the current version
1977 Method* current_method = method_with_idnum((int)idnum);
1978 assert(current_method != NULL, "old and but not obsolete, so should exist");
1979 new_id = Method::make_jmethod_id(class_loader_data(), current_method);
1980 } else {
1981 // It is the current version of the method or an obsolete method,
1982 // use the version passed in
1983 new_id = Method::make_jmethod_id(class_loader_data(), method_h());
1984 }
1985
1986 if (Threads::number_of_threads() == 0 ||
1987 SafepointSynchronize::is_at_safepoint()) {
1988 // we're single threaded or at a safepoint - no locking needed
1989 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1990 &to_dealloc_id, &to_dealloc_jmeths);
1991 } else {
1992 MutexLocker ml(JmethodIdCreation_lock);
1993 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1994 &to_dealloc_id, &to_dealloc_jmeths);
1995 }
1996
1997 // The lock has been dropped so we can free resources.
1998 // Free up either the old cache or the new cache if we allocated one.
1999 if (to_dealloc_jmeths != NULL) {
2000 FreeHeap(to_dealloc_jmeths);
2001 }
2002 // free up the new ID since it wasn't needed
2003 if (to_dealloc_id != NULL) {
2004 Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
2005 }
2006 }
2007 return id;
2008 }
2009
2010 // Figure out how many jmethodIDs haven't been allocated, and make
2011 // sure space for them is pre-allocated. This makes getting all
2012 // method ids much, much faster with classes with more than 8
2013 // methods, and has a *substantial* effect on performance with jvmti
2014 // code that loads all jmethodIDs for all classes.
2015 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2016 int new_jmeths = 0;
2017 int length = methods()->length();
2018 for (int index = start_offset; index < length; index++) {
2019 Method* m = methods()->at(index);
2020 jmethodID id = m->find_jmethod_id_or_null();
2021 if (id == NULL) {
2022 new_jmeths++;
2023 }
2024 }
2025 if (new_jmeths != 0) {
2026 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2027 }
2028 }
2029
2030 // Common code to fetch the jmethodID from the cache or update the
2031 // cache with the new jmethodID. This function should never do anything
2032 // that causes the caller to go to a safepoint or we can deadlock with
2033 // the VMThread or have cache consistency issues.
2034 //
2035 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
2036 size_t idnum, jmethodID new_id,
2037 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
2038 jmethodID** to_dealloc_jmeths_p) {
2039 assert(new_id != NULL, "sanity check");
2040 assert(to_dealloc_id_p != NULL, "sanity check");
2041 assert(to_dealloc_jmeths_p != NULL, "sanity check");
2042 assert(Threads::number_of_threads() == 0 ||
2043 SafepointSynchronize::is_at_safepoint() ||
2044 JmethodIdCreation_lock->owned_by_self(), "sanity check");
2045
2046 // reacquire the cache - we are locked, single threaded or at a safepoint
2047 jmethodID* jmeths = methods_jmethod_ids_acquire();
2048 jmethodID id = NULL;
2049 size_t length = 0;
2050
2051 if (jmeths == NULL || // no cache yet
2052 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
2053 if (jmeths != NULL) {
2054 // copy any existing entries from the old cache
2055 for (size_t index = 0; index < length; index++) {
2056 new_jmeths[index+1] = jmeths[index+1];
2057 }
2058 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
2059 }
2060 release_set_methods_jmethod_ids(jmeths = new_jmeths);
2061 } else {
2062 // fetch jmethodID (if any) from the existing cache
2063 id = jmeths[idnum+1];
2064 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
2065 }
2066 if (id == NULL) {
2067 // No matching jmethodID in the existing cache or we have a new
2068 // cache or we just grew the cache. This cache write is done here
2069 // by the first thread to win the foot race because a jmethodID
2070 // needs to be unique once it is generally available.
2071 id = new_id;
2072
2073 // The jmethodID cache can be read while unlocked so we have to
2074 // make sure the new jmethodID is complete before installing it
2075 // in the cache.
2076 OrderAccess::release_store(&jmeths[idnum+1], id);
2077 } else {
2078 *to_dealloc_id_p = new_id; // save new id for later delete
2079 }
2080 return id;
2081 }
2082
2083
2084 // Common code to get the jmethodID cache length and the jmethodID
2085 // value at index idnum if there is one.
2086 //
2087 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
2088 size_t idnum, size_t *length_p, jmethodID* id_p) {
2089 assert(cache != NULL, "sanity check");
2090 assert(length_p != NULL, "sanity check");
2091 assert(id_p != NULL, "sanity check");
2092
2093 // cache size is stored in element[0], other elements offset by one
2094 *length_p = (size_t)cache[0];
2095 if (*length_p <= idnum) { // cache is too short
2096 *id_p = NULL;
2097 } else {
2098 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
2099 }
2100 }
2101
2102
2103 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
2104 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2105 size_t idnum = (size_t)method->method_idnum();
2106 jmethodID* jmeths = methods_jmethod_ids_acquire();
2107 size_t length; // length assigned as debugging crumb
2108 jmethodID id = NULL;
2109 if (jmeths != NULL && // If there is a cache
2110 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
2111 id = jmeths[idnum+1]; // Look up the id (may be NULL)
2112 }
2113 return id;
2114 }
2115
2116 inline DependencyContext InstanceKlass::dependencies() {
2117 DependencyContext dep_context(&_dep_context);
2118 return dep_context;
2119 }
2120
2121 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
2122 return dependencies().mark_dependent_nmethods(changes);
2123 }
2124
2125 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2126 dependencies().add_dependent_nmethod(nm);
2127 }
2128
2129 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
2130 dependencies().remove_dependent_nmethod(nm, delete_immediately);
2131 }
2132
2133 #ifndef PRODUCT
2134 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2135 dependencies().print_dependent_nmethods(verbose);
2136 }
2137
2138 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2139 return dependencies().is_dependent_nmethod(nm);
2140 }
2141 #endif //PRODUCT
2142
2143 void InstanceKlass::clean_weak_instanceklass_links() {
2144 clean_implementors_list();
2145 clean_method_data();
2146
2147 // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here.
2148 DependencyContext dep_context(&_dep_context);
2149 dep_context.expunge_stale_entries();
2150 }
2151
2152 void InstanceKlass::clean_implementors_list() {
2153 assert(is_loader_alive(), "this klass should be live");
2154 if (is_interface()) {
2155 if (ClassUnloading) {
2156 Klass* impl = implementor();
2157 if (impl != NULL) {
2158 if (!impl->is_loader_alive()) {
2159 // remove this guy
2160 Klass** klass = adr_implementor();
2161 assert(klass != NULL, "null klass");
2162 if (klass != NULL) {
2163 *klass = NULL;
2164 }
2165 }
2166 }
2167 }
2168 }
2169 }
2170
2171 void InstanceKlass::clean_method_data() {
2172 for (int m = 0; m < methods()->length(); m++) {
2173 MethodData* mdo = methods()->at(m)->method_data();
2174 if (mdo != NULL) {
2175 mdo->clean_method_data(/*always_clean*/false);
2176 }
2177 }
2178 }
2179
2180 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
2181 if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
2182 ResourceMark rm;
2183 log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
2184 return false;
2185 }
2186
2187 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
2188 if (local_interfaces != NULL) {
2189 int length = local_interfaces->length();
2190 for (int i = 0; i < length; i++) {
2191 InstanceKlass* intf = local_interfaces->at(i);
2192 if (!intf->has_passed_fingerprint_check()) {
2193 ResourceMark rm;
2194 log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
2195 return false;
2196 }
2197 }
2198 }
2199
2200 return true;
2201 }
2202
2203 bool InstanceKlass::should_store_fingerprint(bool is_unsafe_anonymous) {
2204 #if INCLUDE_AOT
2205 // We store the fingerprint into the InstanceKlass only in the following 2 cases:
2206 if (CalculateClassFingerprint) {
2207 // (1) We are running AOT to generate a shared library.
2208 return true;
2209 }
2210 if (DumpSharedSpaces) {
2211 // (2) We are running -Xshare:dump to create a shared archive
2212 return true;
2213 }
2214 if (UseAOT && is_unsafe_anonymous) {
2215 // (3) We are using AOT code from a shared library and see an unsafe anonymous class
2216 return true;
2217 }
2218 #endif
2219
2220 // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
2221 // but do not store the 64-bit fingerprint to save space.
2222 return false;
2223 }
2224
2225 bool InstanceKlass::has_stored_fingerprint() const {
2226 #if INCLUDE_AOT
2227 return should_store_fingerprint() || is_shared();
2228 #else
2229 return false;
2230 #endif
2231 }
2232
2233 uint64_t InstanceKlass::get_stored_fingerprint() const {
2234 address adr = adr_fingerprint();
2235 if (adr != NULL) {
2236 return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
2237 }
2238 return 0;
2239 }
2240
2241 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
2242 address adr = adr_fingerprint();
2243 if (adr != NULL) {
2244 Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2245
2246 ResourceMark rm;
2247 log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2248 }
2249 }
2250
2251 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2252 Klass::metaspace_pointers_do(it);
2253
2254 if (log_is_enabled(Trace, cds)) {
2255 ResourceMark rm;
2256 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2257 }
2258
2259 it->push(&_annotations);
2260 it->push((Klass**)&_array_klasses);
2261 it->push(&_constants);
2262 it->push(&_inner_classes);
2263 it->push(&_array_name);
2264 #if INCLUDE_JVMTI
2265 it->push(&_previous_versions);
2266 #endif
2267 it->push(&_methods);
2268 it->push(&_default_methods);
2269 it->push(&_local_interfaces);
2270 it->push(&_transitive_interfaces);
2271 it->push(&_method_ordering);
2272 it->push(&_default_vtable_indices);
2273 it->push(&_fields);
2274
2275 if (itable_length() > 0) {
2276 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2277 int method_table_offset_in_words = ioe->offset()/wordSize;
2278 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2279 / itableOffsetEntry::size();
2280
2281 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2282 if (ioe->interface_klass() != NULL) {
2283 it->push(ioe->interface_klass_addr());
2284 itableMethodEntry* ime = ioe->first_method_entry(this);
2285 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2286 for (int index = 0; index < n; index ++) {
2287 it->push(ime[index].method_addr());
2288 }
2289 }
2290 }
2291 }
2292
2293 it->push(&_nest_members);
2294 }
2295
2296 void InstanceKlass::remove_unshareable_info() {
2297 Klass::remove_unshareable_info();
2298
2299 if (is_in_error_state()) {
2300 // Classes are attempted to link during dumping and may fail,
2301 // but these classes are still in the dictionary and class list in CLD.
2302 // Check in_error state first because in_error is > linked state, so
2303 // is_linked() is true.
2304 // If there's a linking error, there is nothing else to remove.
2305 return;
2306 }
2307
2308 // Unlink the class
2309 if (is_linked()) {
2310 unlink_class();
2311 }
2312 {
2313 MutexLocker ml(Compile_lock);
2314 init_implementor();
2315 }
2316
2317 constants()->remove_unshareable_info();
2318
2319 for (int i = 0; i < methods()->length(); i++) {
2320 Method* m = methods()->at(i);
2321 m->remove_unshareable_info();
2322 }
2323
2324 // do array classes also.
2325 if (array_klasses() != NULL) {
2326 array_klasses()->remove_unshareable_info();
2327 }
2328
2329 // These are not allocated from metaspace, but they should should all be empty
2330 // during dump time, so we don't need to worry about them in InstanceKlass::iterate().
2331 guarantee(_source_debug_extension == NULL, "must be");
2332 guarantee(_dep_context == DependencyContext::EMPTY, "must be");
2333 guarantee(_osr_nmethods_head == NULL, "must be");
2334
2335 #if INCLUDE_JVMTI
2336 guarantee(_breakpoints == NULL, "must be");
2337 guarantee(_previous_versions == NULL, "must be");
2338 #endif
2339
2340 _init_thread = NULL;
2341 _methods_jmethod_ids = NULL;
2342 _jni_ids = NULL;
2343 _oop_map_cache = NULL;
2344 // clear _nest_host to ensure re-load at runtime
2345 _nest_host = NULL;
2346 }
2347
2348 void InstanceKlass::remove_java_mirror() {
2349 Klass::remove_java_mirror();
2350
2351 // do array classes also.
2352 if (array_klasses() != NULL) {
2353 array_klasses()->remove_java_mirror();
2354 }
2355 }
2356
2357 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2358 set_package(loader_data, CHECK);
2359 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2360
2361 Array<Method*>* methods = this->methods();
2362 int num_methods = methods->length();
2363 for (int index2 = 0; index2 < num_methods; ++index2) {
2364 methodHandle m(THREAD, methods->at(index2));
2365 m->restore_unshareable_info(CHECK);
2366 }
2367 if (JvmtiExport::has_redefined_a_class()) {
2368 // Reinitialize vtable because RedefineClasses may have changed some
2369 // entries in this vtable for super classes so the CDS vtable might
2370 // point to old or obsolete entries. RedefineClasses doesn't fix up
2371 // vtables in the shared system dictionary, only the main one.
2372 // It also redefines the itable too so fix that too.
2373 vtable().initialize_vtable(false, CHECK);
2374 itable().initialize_itable(false, CHECK);
2375 }
2376
2377 // restore constant pool resolved references
2378 constants()->restore_unshareable_info(CHECK);
2379
2380 if (array_klasses() != NULL) {
2381 // Array classes have null protection domain.
2382 // --> see ArrayKlass::complete_create_array_klass()
2383 array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2384 }
2385 }
2386
2387 // returns true IFF is_in_error_state() has been changed as a result of this call.
2388 bool InstanceKlass::check_sharing_error_state() {
2389 assert(DumpSharedSpaces, "should only be called during dumping");
2390 bool old_state = is_in_error_state();
2391
2392 if (!is_in_error_state()) {
2393 bool bad = false;
2394 for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2395 if (sup->is_in_error_state()) {
2396 bad = true;
2397 break;
2398 }
2399 }
2400 if (!bad) {
2401 Array<InstanceKlass*>* interfaces = transitive_interfaces();
2402 for (int i = 0; i < interfaces->length(); i++) {
2403 InstanceKlass* iface = interfaces->at(i);
2404 if (iface->is_in_error_state()) {
2405 bad = true;
2406 break;
2407 }
2408 }
2409 }
2410
2411 if (bad) {
2412 set_in_error_state();
2413 }
2414 }
2415
2416 return (old_state != is_in_error_state());
2417 }
2418
2419 #if INCLUDE_JVMTI
2420 static void clear_all_breakpoints(Method* m) {
2421 m->clear_all_breakpoints();
2422 }
2423 #endif
2424
2425 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2426 // notify the debugger
2427 if (JvmtiExport::should_post_class_unload()) {
2428 JvmtiExport::post_class_unload(ik);
2429 }
2430
2431 // notify ClassLoadingService of class unload
2432 ClassLoadingService::notify_class_unloaded(ik);
2433
2434 #if INCLUDE_JFR
2435 if (Jfr::is_enabled()) {
2436 assert(ik != NULL, "invariant");
2437 EventClassUnload event(UNTIMED);
2438 event.set_endtime(class_unload_time());
2439 event.set_unloadedClass(ik);
2440 event.set_definingClassLoader(ik->class_loader_data());
2441 event.commit();
2442 }
2443 #endif
2444
2445 }
2446
2447 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2448 // Clean up C heap
2449 ik->release_C_heap_structures();
2450 ik->constants()->release_C_heap_structures();
2451 }
2452
2453 void InstanceKlass::release_C_heap_structures() {
2454 // Can't release the constant pool here because the constant pool can be
2455 // deallocated separately from the InstanceKlass for default methods and
2456 // redefine classes.
2457
2458 // Deallocate oop map cache
2459 if (_oop_map_cache != NULL) {
2460 delete _oop_map_cache;
2461 _oop_map_cache = NULL;
2462 }
2463
2464 // Deallocate JNI identifiers for jfieldIDs
2465 JNIid::deallocate(jni_ids());
2466 set_jni_ids(NULL);
2467
2468 jmethodID* jmeths = methods_jmethod_ids_acquire();
2469 if (jmeths != (jmethodID*)NULL) {
2470 release_set_methods_jmethod_ids(NULL);
2471 FreeHeap(jmeths);
2472 }
2473
2474 // Release dependencies.
2475 // It is desirable to use DC::remove_all_dependents() here, but, unfortunately,
2476 // it is not safe (see JDK-8143408). The problem is that the klass dependency
2477 // context can contain live dependencies, since there's a race between nmethod &
2478 // klass unloading. If the klass is dead when nmethod unloading happens, relevant
2479 // dependencies aren't removed from the context associated with the class (see
2480 // nmethod::flush_dependencies). It ends up during klass unloading as seemingly
2481 // live dependencies pointing to unloaded nmethods and causes a crash in
2482 // DC::remove_all_dependents() when it touches unloaded nmethod.
2483 dependencies().wipe();
2484
2485 #if INCLUDE_JVMTI
2486 // Deallocate breakpoint records
2487 if (breakpoints() != 0x0) {
2488 methods_do(clear_all_breakpoints);
2489 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2490 }
2491
2492 // deallocate the cached class file
2493 if (_cached_class_file != NULL && !MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
2494 os::free(_cached_class_file);
2495 _cached_class_file = NULL;
2496 }
2497 #endif
2498
2499 // Decrement symbol reference counts associated with the unloaded class.
2500 if (_name != NULL) _name->decrement_refcount();
2501 // unreference array name derived from this class name (arrays of an unloaded
2502 // class can't be referenced anymore).
2503 if (_array_name != NULL) _array_name->decrement_refcount();
2504 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2505 }
2506
2507 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2508 if (array == NULL) {
2509 _source_debug_extension = NULL;
2510 } else {
2511 // Adding one to the attribute length in order to store a null terminator
2512 // character could cause an overflow because the attribute length is
2513 // already coded with an u4 in the classfile, but in practice, it's
2514 // unlikely to happen.
2515 assert((length+1) > length, "Overflow checking");
2516 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2517 for (int i = 0; i < length; i++) {
2518 sde[i] = array[i];
2519 }
2520 sde[length] = '\0';
2521 _source_debug_extension = sde;
2522 }
2523 }
2524
2525 const char* InstanceKlass::signature_name() const {
2526 int hash_len = 0;
2527 char hash_buf[40];
2528
2529 // If this is an unsafe anonymous class, append a hash to make the name unique
2530 if (is_unsafe_anonymous()) {
2531 intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2532 jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2533 hash_len = (int)strlen(hash_buf);
2534 }
2535
2536 // Get the internal name as a c string
2537 const char* src = (const char*) (name()->as_C_string());
2538 const int src_length = (int)strlen(src);
2539
2540 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2541
2542 // Add L as type indicator
2543 int dest_index = 0;
2544 dest[dest_index++] = 'L';
2545
2546 // Add the actual class name
2547 for (int src_index = 0; src_index < src_length; ) {
2548 dest[dest_index++] = src[src_index++];
2549 }
2550
2551 // If we have a hash, append it
2552 for (int hash_index = 0; hash_index < hash_len; ) {
2553 dest[dest_index++] = hash_buf[hash_index++];
2554 }
2555
2556 // Add the semicolon and the NULL
2557 dest[dest_index++] = ';';
2558 dest[dest_index] = '\0';
2559 return dest;
2560 }
2561
2562 // Used to obtain the package name from a fully qualified class name.
2563 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2564 if (name == NULL) {
2565 return NULL;
2566 } else {
2567 if (name->utf8_length() <= 0) {
2568 return NULL;
2569 }
2570 ResourceMark rm;
2571 const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2572 if (package_name == NULL) {
2573 return NULL;
2574 }
2575 Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD);
2576 return pkg_name;
2577 }
2578 }
2579
2580 ModuleEntry* InstanceKlass::module() const {
2581 // For an unsafe anonymous class return the host class' module
2582 if (is_unsafe_anonymous()) {
2583 assert(unsafe_anonymous_host() != NULL, "unsafe anonymous class must have a host class");
2584 return unsafe_anonymous_host()->module();
2585 }
2586
2587 // Class is in a named package
2588 if (!in_unnamed_package()) {
2589 return _package_entry->module();
2590 }
2591
2592 // Class is in an unnamed package, return its loader's unnamed module
2593 return class_loader_data()->unnamed_module();
2594 }
2595
2596 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2597
2598 // ensure java/ packages only loaded by boot or platform builtin loaders
2599 check_prohibited_package(name(), loader_data, CHECK);
2600
2601 TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2602
2603 if (pkg_name != NULL && loader_data != NULL) {
2604
2605 // Find in class loader's package entry table.
2606 _package_entry = loader_data->packages()->lookup_only(pkg_name);
2607
2608 // If the package name is not found in the loader's package
2609 // entry table, it is an indication that the package has not
2610 // been defined. Consider it defined within the unnamed module.
2611 if (_package_entry == NULL) {
2612 ResourceMark rm;
2613
2614 if (!ModuleEntryTable::javabase_defined()) {
2615 // Before java.base is defined during bootstrapping, define all packages in
2616 // the java.base module. If a non-java.base package is erroneously placed
2617 // in the java.base module it will be caught later when java.base
2618 // is defined by ModuleEntryTable::verify_javabase_packages check.
2619 assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2620 _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2621 } else {
2622 assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2623 _package_entry = loader_data->packages()->lookup(pkg_name,
2624 loader_data->unnamed_module());
2625 }
2626
2627 // A package should have been successfully created
2628 assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2629 name()->as_C_string(), loader_data->loader_name_and_id());
2630 }
2631
2632 if (log_is_enabled(Debug, module)) {
2633 ResourceMark rm;
2634 ModuleEntry* m = _package_entry->module();
2635 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2636 external_name(),
2637 pkg_name->as_C_string(),
2638 loader_data->loader_name_and_id(),
2639 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2640 }
2641 } else {
2642 ResourceMark rm;
2643 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2644 external_name(),
2645 (loader_data != NULL) ? loader_data->loader_name_and_id() : "NULL",
2646 UNNAMED_MODULE);
2647 }
2648 }
2649
2650
2651 // different versions of is_same_class_package
2652
2653 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2654 oop classloader1 = this->class_loader();
2655 PackageEntry* classpkg1 = this->package();
2656 if (class2->is_objArray_klass()) {
2657 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2658 }
2659
2660 oop classloader2;
2661 PackageEntry* classpkg2;
2662 if (class2->is_instance_klass()) {
2663 classloader2 = class2->class_loader();
2664 classpkg2 = class2->package();
2665 } else {
2666 assert(class2->is_typeArray_klass(), "should be type array");
2667 classloader2 = NULL;
2668 classpkg2 = NULL;
2669 }
2670
2671 // Same package is determined by comparing class loader
2672 // and package entries. Both must be the same. This rule
2673 // applies even to classes that are defined in the unnamed
2674 // package, they still must have the same class loader.
2675 if (oopDesc::equals(classloader1, classloader2) && (classpkg1 == classpkg2)) {
2676 return true;
2677 }
2678
2679 return false;
2680 }
2681
2682 // return true if this class and other_class are in the same package. Classloader
2683 // and classname information is enough to determine a class's package
2684 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2685 const Symbol* other_class_name) const {
2686 if (!oopDesc::equals(class_loader(), other_class_loader)) {
2687 return false;
2688 }
2689 if (name()->fast_compare(other_class_name) == 0) {
2690 return true;
2691 }
2692
2693 {
2694 ResourceMark rm;
2695
2696 bool bad_class_name = false;
2697 const char* other_pkg =
2698 ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2699 if (bad_class_name) {
2700 return false;
2701 }
2702 // Check that package_from_name() returns NULL, not "", if there is no package.
2703 assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2704
2705 const Symbol* const this_package_name =
2706 this->package() != NULL ? this->package()->name() : NULL;
2707
2708 if (this_package_name == NULL || other_pkg == NULL) {
2709 // One of the two doesn't have a package. Only return true if the other
2710 // one also doesn't have a package.
2711 return (const char*)this_package_name == other_pkg;
2712 }
2713
2714 // Check if package is identical
2715 return this_package_name->equals(other_pkg);
2716 }
2717 }
2718
2719 // Returns true iff super_method can be overridden by a method in targetclassname
2720 // See JLS 3rd edition 8.4.6.1
2721 // Assumes name-signature match
2722 // "this" is InstanceKlass of super_method which must exist
2723 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2724 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2725 // Private methods can not be overridden
2726 if (super_method->is_private()) {
2727 return false;
2728 }
2729 // If super method is accessible, then override
2730 if ((super_method->is_protected()) ||
2731 (super_method->is_public())) {
2732 return true;
2733 }
2734 // Package-private methods are not inherited outside of package
2735 assert(super_method->is_package_private(), "must be package private");
2736 return(is_same_class_package(targetclassloader(), targetclassname));
2737 }
2738
2739 // Only boot and platform class loaders can define classes in "java/" packages.
2740 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2741 ClassLoaderData* loader_data,
2742 TRAPS) {
2743 if (!loader_data->is_boot_class_loader_data() &&
2744 !loader_data->is_platform_class_loader_data() &&
2745 class_name != NULL) {
2746 ResourceMark rm(THREAD);
2747 char* name = class_name->as_C_string();
2748 if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2749 TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2750 assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2751 name = pkg_name->as_C_string();
2752 const char* class_loader_name = loader_data->loader_name_and_id();
2753 StringUtils::replace_no_expand(name, "/", ".");
2754 const char* msg_text1 = "Class loader (instance of): ";
2755 const char* msg_text2 = " tried to load prohibited package name: ";
2756 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2757 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2758 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2759 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2760 }
2761 }
2762 return;
2763 }
2764
2765 // tell if two classes have the same enclosing class (at package level)
2766 bool InstanceKlass::is_same_package_member(const Klass* class2, TRAPS) const {
2767 if (class2 == this) return true;
2768 if (!class2->is_instance_klass()) return false;
2769
2770 // must be in same package before we try anything else
2771 if (!is_same_class_package(class2))
2772 return false;
2773
2774 // As long as there is an outer_this.getEnclosingClass,
2775 // shift the search outward.
2776 const InstanceKlass* outer_this = this;
2777 for (;;) {
2778 // As we walk along, look for equalities between outer_this and class2.
2779 // Eventually, the walks will terminate as outer_this stops
2780 // at the top-level class around the original class.
2781 bool ignore_inner_is_member;
2782 const Klass* next = outer_this->compute_enclosing_class(&ignore_inner_is_member,
2783 CHECK_false);
2784 if (next == NULL) break;
2785 if (next == class2) return true;
2786 outer_this = InstanceKlass::cast(next);
2787 }
2788
2789 // Now do the same for class2.
2790 const InstanceKlass* outer2 = InstanceKlass::cast(class2);
2791 for (;;) {
2792 bool ignore_inner_is_member;
2793 Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2794 CHECK_false);
2795 if (next == NULL) break;
2796 // Might as well check the new outer against all available values.
2797 if (next == this) return true;
2798 if (next == outer_this) return true;
2799 outer2 = InstanceKlass::cast(next);
2800 }
2801
2802 // If by this point we have not found an equality between the
2803 // two classes, we know they are in separate package members.
2804 return false;
2805 }
2806
2807 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2808 constantPoolHandle i_cp(THREAD, constants());
2809 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2810 int ioff = iter.inner_class_info_index();
2811 if (ioff != 0) {
2812 // Check to see if the name matches the class we're looking for
2813 // before attempting to find the class.
2814 if (i_cp->klass_name_at_matches(this, ioff)) {
2815 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2816 if (this == inner_klass) {
2817 *ooff = iter.outer_class_info_index();
2818 *noff = iter.inner_name_index();
2819 return true;
2820 }
2821 }
2822 }
2823 }
2824 return false;
2825 }
2826
2827 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2828 InstanceKlass* outer_klass = NULL;
2829 *inner_is_member = false;
2830 int ooff = 0, noff = 0;
2831 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2832 if (has_inner_classes_attr) {
2833 constantPoolHandle i_cp(THREAD, constants());
2834 if (ooff != 0) {
2835 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2836 outer_klass = InstanceKlass::cast(ok);
2837 *inner_is_member = true;
2838 }
2839 if (NULL == outer_klass) {
2840 // It may be unsafe anonymous; try for that.
2841 int encl_method_class_idx = enclosing_method_class_index();
2842 if (encl_method_class_idx != 0) {
2843 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2844 outer_klass = InstanceKlass::cast(ok);
2845 *inner_is_member = false;
2846 }
2847 }
2848 }
2849
2850 // If no inner class attribute found for this class.
2851 if (NULL == outer_klass) return NULL;
2852
2853 // Throws an exception if outer klass has not declared k as an inner klass
2854 // We need evidence that each klass knows about the other, or else
2855 // the system could allow a spoof of an inner class to gain access rights.
2856 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2857 return outer_klass;
2858 }
2859
2860 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2861 jint access = access_flags().as_int();
2862
2863 // But check if it happens to be member class.
2864 InnerClassesIterator iter(this);
2865 for (; !iter.done(); iter.next()) {
2866 int ioff = iter.inner_class_info_index();
2867 // Inner class attribute can be zero, skip it.
2868 // Strange but true: JVM spec. allows null inner class refs.
2869 if (ioff == 0) continue;
2870
2871 // only look at classes that are already loaded
2872 // since we are looking for the flags for our self.
2873 Symbol* inner_name = constants()->klass_name_at(ioff);
2874 if (name() == inner_name) {
2875 // This is really a member class.
2876 access = iter.inner_access_flags();
2877 break;
2878 }
2879 }
2880 // Remember to strip ACC_SUPER bit
2881 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2882 }
2883
2884 jint InstanceKlass::jvmti_class_status() const {
2885 jint result = 0;
2886
2887 if (is_linked()) {
2888 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2889 }
2890
2891 if (is_initialized()) {
2892 assert(is_linked(), "Class status is not consistent");
2893 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2894 }
2895 if (is_in_error_state()) {
2896 result |= JVMTI_CLASS_STATUS_ERROR;
2897 }
2898 return result;
2899 }
2900
2901 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2902 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2903 int method_table_offset_in_words = ioe->offset()/wordSize;
2904 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2905 / itableOffsetEntry::size();
2906
2907 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2908 // If the interface isn't implemented by the receiver class,
2909 // the VM should throw IncompatibleClassChangeError.
2910 if (cnt >= nof_interfaces) {
2911 ResourceMark rm(THREAD);
2912 stringStream ss;
2913 bool same_module = (module() == holder->module());
2914 ss.print("Receiver class %s does not implement "
2915 "the interface %s defining the method to be called "
2916 "(%s%s%s)",
2917 external_name(), holder->external_name(),
2918 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
2919 (same_module) ? "" : "; ",
2920 (same_module) ? "" : holder->class_in_module_of_loader());
2921 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
2922 }
2923
2924 Klass* ik = ioe->interface_klass();
2925 if (ik == holder) break;
2926 }
2927
2928 itableMethodEntry* ime = ioe->first_method_entry(this);
2929 Method* m = ime[index].method();
2930 if (m == NULL) {
2931 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2932 }
2933 return m;
2934 }
2935
2936
2937 #if INCLUDE_JVMTI
2938 // update default_methods for redefineclasses for methods that are
2939 // not yet in the vtable due to concurrent subclass define and superinterface
2940 // redefinition
2941 // Note: those in the vtable, should have been updated via adjust_method_entries
2942 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2943 // search the default_methods for uses of either obsolete or EMCP methods
2944 if (default_methods() != NULL) {
2945 for (int index = 0; index < default_methods()->length(); index ++) {
2946 Method* old_method = default_methods()->at(index);
2947 if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2948 continue; // skip uninteresting entries
2949 }
2950 assert(!old_method->is_deleted(), "default methods may not be deleted");
2951
2952 Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2953
2954 assert(new_method != NULL, "method_with_idnum() should not be NULL");
2955 assert(old_method != new_method, "sanity check");
2956
2957 default_methods()->at_put(index, new_method);
2958 if (log_is_enabled(Info, redefine, class, update)) {
2959 ResourceMark rm;
2960 if (!(*trace_name_printed)) {
2961 log_info(redefine, class, update)
2962 ("adjust: klassname=%s default methods from name=%s",
2963 external_name(), old_method->method_holder()->external_name());
2964 *trace_name_printed = true;
2965 }
2966 log_debug(redefine, class, update, vtables)
2967 ("default method update: %s(%s) ",
2968 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
2969 }
2970 }
2971 }
2972 }
2973 #endif // INCLUDE_JVMTI
2974
2975 // On-stack replacement stuff
2976 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2977 // only one compilation can be active
2978 {
2979 // This is a short non-blocking critical region, so the no safepoint check is ok.
2980 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2981 assert(n->is_osr_method(), "wrong kind of nmethod");
2982 n->set_osr_link(osr_nmethods_head());
2983 set_osr_nmethods_head(n);
2984 // Raise the highest osr level if necessary
2985 if (TieredCompilation) {
2986 Method* m = n->method();
2987 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2988 }
2989 }
2990
2991 // Get rid of the osr methods for the same bci that have lower levels.
2992 if (TieredCompilation) {
2993 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2994 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2995 if (inv != NULL && inv->is_in_use()) {
2996 inv->make_not_entrant();
2997 }
2998 }
2999 }
3000 }
3001
3002 // Remove osr nmethod from the list. Return true if found and removed.
3003 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
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 assert(n->is_osr_method(), "wrong kind of nmethod");
3007 nmethod* last = NULL;
3008 nmethod* cur = osr_nmethods_head();
3009 int max_level = CompLevel_none; // Find the max comp level excluding n
3010 Method* m = n->method();
3011 // Search for match
3012 bool found = false;
3013 while(cur != NULL && cur != n) {
3014 if (TieredCompilation && m == cur->method()) {
3015 // Find max level before n
3016 max_level = MAX2(max_level, cur->comp_level());
3017 }
3018 last = cur;
3019 cur = cur->osr_link();
3020 }
3021 nmethod* next = NULL;
3022 if (cur == n) {
3023 found = true;
3024 next = cur->osr_link();
3025 if (last == NULL) {
3026 // Remove first element
3027 set_osr_nmethods_head(next);
3028 } else {
3029 last->set_osr_link(next);
3030 }
3031 }
3032 n->set_osr_link(NULL);
3033 if (TieredCompilation) {
3034 cur = next;
3035 while (cur != NULL) {
3036 // Find max level after n
3037 if (m == cur->method()) {
3038 max_level = MAX2(max_level, cur->comp_level());
3039 }
3040 cur = cur->osr_link();
3041 }
3042 m->set_highest_osr_comp_level(max_level);
3043 }
3044 return found;
3045 }
3046
3047 int InstanceKlass::mark_osr_nmethods(const Method* m) {
3048 // This is a short non-blocking critical region, so the no safepoint check is ok.
3049 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
3050 nmethod* osr = osr_nmethods_head();
3051 int found = 0;
3052 while (osr != NULL) {
3053 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3054 if (osr->method() == m) {
3055 osr->mark_for_deoptimization();
3056 found++;
3057 }
3058 osr = osr->osr_link();
3059 }
3060 return found;
3061 }
3062
3063 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3064 // This is a short non-blocking critical region, so the no safepoint check is ok.
3065 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
3066 nmethod* osr = osr_nmethods_head();
3067 nmethod* best = NULL;
3068 while (osr != NULL) {
3069 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3070 // There can be a time when a c1 osr method exists but we are waiting
3071 // for a c2 version. When c2 completes its osr nmethod we will trash
3072 // the c1 version and only be able to find the c2 version. However
3073 // while we overflow in the c1 code at back branches we don't want to
3074 // try and switch to the same code as we are already running
3075
3076 if (osr->method() == m &&
3077 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3078 if (match_level) {
3079 if (osr->comp_level() == comp_level) {
3080 // Found a match - return it.
3081 return osr;
3082 }
3083 } else {
3084 if (best == NULL || (osr->comp_level() > best->comp_level())) {
3085 if (osr->comp_level() == CompLevel_highest_tier) {
3086 // Found the best possible - return it.
3087 return osr;
3088 }
3089 best = osr;
3090 }
3091 }
3092 }
3093 osr = osr->osr_link();
3094 }
3095 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
3096 return best;
3097 }
3098 return NULL;
3099 }
3100
3101 // -----------------------------------------------------------------------------------------------------
3102 // Printing
3103
3104 #ifndef PRODUCT
3105
3106 #define BULLET " - "
3107
3108 static const char* state_names[] = {
3109 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3110 };
3111
3112 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3113 for (int i = 0; i < len; i++) {
3114 intptr_t e = start[i];
3115 st->print("%d : " INTPTR_FORMAT, i, e);
3116 if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
3117 st->print(" ");
3118 ((Metadata*)e)->print_value_on(st);
3119 }
3120 st->cr();
3121 }
3122 }
3123
3124 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3125 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3126 }
3127
3128 void InstanceKlass::print_on(outputStream* st) const {
3129 assert(is_klass(), "must be klass");
3130 Klass::print_on(st);
3131
3132 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3133 st->print(BULLET"klass size: %d", size()); st->cr();
3134 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3135 st->print(BULLET"state: "); st->print_cr("%s", state_names[_init_state]);
3136 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3137 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3138 st->print(BULLET"sub: ");
3139 Klass* sub = subklass();
3140 int n;
3141 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
3142 if (n < MaxSubklassPrintSize) {
3143 sub->print_value_on(st);
3144 st->print(" ");
3145 }
3146 }
3147 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3148 st->cr();
3149
3150 if (is_interface()) {
3151 MutexLocker ml(Compile_lock);
3152 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3153 if (nof_implementors() == 1) {
3154 st->print_cr(BULLET"implementor: ");
3155 st->print(" ");
3156 implementor()->print_value_on(st);
3157 st->cr();
3158 }
3159 }
3160
3161 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3162 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3163 if (Verbose || WizardMode) {
3164 Array<Method*>* method_array = methods();
3165 for (int i = 0; i < method_array->length(); i++) {
3166 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3167 }
3168 }
3169 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3170 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3171 if (Verbose && default_methods() != NULL) {
3172 Array<Method*>* method_array = default_methods();
3173 for (int i = 0; i < method_array->length(); i++) {
3174 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3175 }
3176 }
3177 if (default_vtable_indices() != NULL) {
3178 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
3179 }
3180 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3181 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3182 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3183 if (class_loader_data() != NULL) {
3184 st->print(BULLET"class loader data: ");
3185 class_loader_data()->print_value_on(st);
3186 st->cr();
3187 }
3188 st->print(BULLET"unsafe anonymous host class: "); Metadata::print_value_on_maybe_null(st, unsafe_anonymous_host()); st->cr();
3189 if (source_file_name() != NULL) {
3190 st->print(BULLET"source file: ");
3191 source_file_name()->print_value_on(st);
3192 st->cr();
3193 }
3194 if (source_debug_extension() != NULL) {
3195 st->print(BULLET"source debug extension: ");
3196 st->print("%s", source_debug_extension());
3197 st->cr();
3198 }
3199 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
3200 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
3201 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
3202 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
3203 {
3204 bool have_pv = false;
3205 // previous versions are linked together through the InstanceKlass
3206 for (InstanceKlass* pv_node = previous_versions();
3207 pv_node != NULL;
3208 pv_node = pv_node->previous_versions()) {
3209 if (!have_pv)
3210 st->print(BULLET"previous version: ");
3211 have_pv = true;
3212 pv_node->constants()->print_value_on(st);
3213 }
3214 if (have_pv) st->cr();
3215 }
3216
3217 if (generic_signature() != NULL) {
3218 st->print(BULLET"generic signature: ");
3219 generic_signature()->print_value_on(st);
3220 st->cr();
3221 }
3222 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3223 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3224 if (java_mirror() != NULL) {
3225 st->print(BULLET"java mirror: ");
3226 java_mirror()->print_value_on(st);
3227 st->cr();
3228 } else {
3229 st->print_cr(BULLET"java mirror: NULL");
3230 }
3231 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3232 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3233 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3234 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3235 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3236 FieldPrinter print_static_field(st);
3237 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3238 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3239 FieldPrinter print_nonstatic_field(st);
3240 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3241 ik->do_nonstatic_fields(&print_nonstatic_field);
3242
3243 st->print(BULLET"non-static oop maps: ");
3244 OopMapBlock* map = start_of_nonstatic_oop_maps();
3245 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3246 while (map < end_map) {
3247 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3248 map++;
3249 }
3250 st->cr();
3251 }
3252
3253 #endif //PRODUCT
3254
3255 void InstanceKlass::print_value_on(outputStream* st) const {
3256 assert(is_klass(), "must be klass");
3257 if (Verbose || WizardMode) access_flags().print_on(st);
3258 name()->print_value_on(st);
3259 }
3260
3261 #ifndef PRODUCT
3262
3263 void FieldPrinter::do_field(fieldDescriptor* fd) {
3264 _st->print(BULLET);
3265 if (_obj == NULL) {
3266 fd->print_on(_st);
3267 _st->cr();
3268 } else {
3269 fd->print_on_for(_st, _obj);
3270 _st->cr();
3271 }
3272 }
3273
3274
3275 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3276 Klass::oop_print_on(obj, st);
3277
3278 if (this == SystemDictionary::String_klass()) {
3279 typeArrayOop value = java_lang_String::value(obj);
3280 juint length = java_lang_String::length(obj);
3281 if (value != NULL &&
3282 value->is_typeArray() &&
3283 length <= (juint) value->length()) {
3284 st->print(BULLET"string: ");
3285 java_lang_String::print(obj, st);
3286 st->cr();
3287 if (!WizardMode) return; // that is enough
3288 }
3289 }
3290
3291 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3292 FieldPrinter print_field(st, obj);
3293 do_nonstatic_fields(&print_field);
3294
3295 if (this == SystemDictionary::Class_klass()) {
3296 st->print(BULLET"signature: ");
3297 java_lang_Class::print_signature(obj, st);
3298 st->cr();
3299 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3300 st->print(BULLET"fake entry for mirror: ");
3301 Metadata::print_value_on_maybe_null(st, mirrored_klass);
3302 st->cr();
3303 Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3304 st->print(BULLET"fake entry for array: ");
3305 Metadata::print_value_on_maybe_null(st, array_klass);
3306 st->cr();
3307 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3308 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3309 Klass* real_klass = java_lang_Class::as_Klass(obj);
3310 if (real_klass != NULL && real_klass->is_instance_klass()) {
3311 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3312 }
3313 } else if (this == SystemDictionary::MethodType_klass()) {
3314 st->print(BULLET"signature: ");
3315 java_lang_invoke_MethodType::print_signature(obj, st);
3316 st->cr();
3317 }
3318 }
3319
3320 bool InstanceKlass::verify_itable_index(int i) {
3321 int method_count = klassItable::method_count_for_interface(this);
3322 assert(i >= 0 && i < method_count, "index out of bounds");
3323 return true;
3324 }
3325
3326 #endif //PRODUCT
3327
3328 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3329 st->print("a ");
3330 name()->print_value_on(st);
3331 obj->print_address_on(st);
3332 if (this == SystemDictionary::String_klass()
3333 && java_lang_String::value(obj) != NULL) {
3334 ResourceMark rm;
3335 int len = java_lang_String::length(obj);
3336 int plen = (len < 24 ? len : 12);
3337 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3338 st->print(" = \"%s\"", str);
3339 if (len > plen)
3340 st->print("...[%d]", len);
3341 } else if (this == SystemDictionary::Class_klass()) {
3342 Klass* k = java_lang_Class::as_Klass(obj);
3343 st->print(" = ");
3344 if (k != NULL) {
3345 k->print_value_on(st);
3346 } else {
3347 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3348 st->print("%s", tname ? tname : "type?");
3349 }
3350 } else if (this == SystemDictionary::MethodType_klass()) {
3351 st->print(" = ");
3352 java_lang_invoke_MethodType::print_signature(obj, st);
3353 } else if (java_lang_boxing_object::is_instance(obj)) {
3354 st->print(" = ");
3355 java_lang_boxing_object::print(obj, st);
3356 } else if (this == SystemDictionary::LambdaForm_klass()) {
3357 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3358 if (vmentry != NULL) {
3359 st->print(" => ");
3360 vmentry->print_value_on(st);
3361 }
3362 } else if (this == SystemDictionary::MemberName_klass()) {
3363 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3364 if (vmtarget != NULL) {
3365 st->print(" = ");
3366 vmtarget->print_value_on(st);
3367 } else {
3368 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3369 st->print(".");
3370 java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3371 }
3372 }
3373 }
3374
3375 const char* InstanceKlass::internal_name() const {
3376 return external_name();
3377 }
3378
3379 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3380 const char* module_name,
3381 const ClassFileStream* cfs) const {
3382 if (!log_is_enabled(Info, class, load)) {
3383 return;
3384 }
3385
3386 ResourceMark rm;
3387 LogMessage(class, load) msg;
3388 stringStream info_stream;
3389
3390 // Name and class hierarchy info
3391 info_stream.print("%s", external_name());
3392
3393 // Source
3394 if (cfs != NULL) {
3395 if (cfs->source() != NULL) {
3396 if (module_name != NULL) {
3397 if (ClassLoader::is_modules_image(cfs->source())) {
3398 info_stream.print(" source: jrt:/%s", module_name);
3399 } else {
3400 info_stream.print(" source: %s", cfs->source());
3401 }
3402 } else {
3403 info_stream.print(" source: %s", cfs->source());
3404 }
3405 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3406 Thread* THREAD = Thread::current();
3407 Klass* caller =
3408 THREAD->is_Java_thread()
3409 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3410 : NULL;
3411 // caller can be NULL, for example, during a JVMTI VM_Init hook
3412 if (caller != NULL) {
3413 info_stream.print(" source: instance of %s", caller->external_name());
3414 } else {
3415 // source is unknown
3416 }
3417 } else {
3418 oop class_loader = loader_data->class_loader();
3419 info_stream.print(" source: %s", class_loader->klass()->external_name());
3420 }
3421 } else {
3422 info_stream.print(" source: shared objects file");
3423 }
3424
3425 msg.info("%s", info_stream.as_string());
3426
3427 if (log_is_enabled(Debug, class, load)) {
3428 stringStream debug_stream;
3429
3430 // Class hierarchy info
3431 debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3432 p2i(this), p2i(superklass()));
3433
3434 // Interfaces
3435 if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3436 debug_stream.print(" interfaces:");
3437 int length = local_interfaces()->length();
3438 for (int i = 0; i < length; i++) {
3439 debug_stream.print(" " INTPTR_FORMAT,
3440 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3441 }
3442 }
3443
3444 // Class loader
3445 debug_stream.print(" loader: [");
3446 loader_data->print_value_on(&debug_stream);
3447 debug_stream.print("]");
3448
3449 // Classfile checksum
3450 if (cfs) {
3451 debug_stream.print(" bytes: %d checksum: %08x",
3452 cfs->length(),
3453 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3454 cfs->length()));
3455 }
3456
3457 msg.debug("%s", debug_stream.as_string());
3458 }
3459 }
3460
3461 #if INCLUDE_SERVICES
3462 // Size Statistics
3463 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3464 Klass::collect_statistics(sz);
3465
3466 sz->_inst_size = wordSize * size_helper();
3467 sz->_vtab_bytes = wordSize * vtable_length();
3468 sz->_itab_bytes = wordSize * itable_length();
3469 sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3470
3471 int n = 0;
3472 n += (sz->_methods_array_bytes = sz->count_array(methods()));
3473 n += (sz->_method_ordering_bytes = sz->count_array(method_ordering()));
3474 n += (sz->_local_interfaces_bytes = sz->count_array(local_interfaces()));
3475 n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3476 n += (sz->_fields_bytes = sz->count_array(fields()));
3477 n += (sz->_inner_classes_bytes = sz->count_array(inner_classes()));
3478 n += (sz->_nest_members_bytes = sz->count_array(nest_members()));
3479 sz->_ro_bytes += n;
3480
3481 const ConstantPool* cp = constants();
3482 if (cp) {
3483 cp->collect_statistics(sz);
3484 }
3485
3486 const Annotations* anno = annotations();
3487 if (anno) {
3488 anno->collect_statistics(sz);
3489 }
3490
3491 const Array<Method*>* methods_array = methods();
3492 if (methods()) {
3493 for (int i = 0; i < methods_array->length(); i++) {
3494 Method* method = methods_array->at(i);
3495 if (method) {
3496 sz->_method_count ++;
3497 method->collect_statistics(sz);
3498 }
3499 }
3500 }
3501 }
3502 #endif // INCLUDE_SERVICES
3503
3504 // Verification
3505
3506 class VerifyFieldClosure: public BasicOopIterateClosure {
3507 protected:
3508 template <class T> void do_oop_work(T* p) {
3509 oop obj = RawAccess<>::oop_load(p);
3510 if (!oopDesc::is_oop_or_null(obj)) {
3511 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3512 Universe::print_on(tty);
3513 guarantee(false, "boom");
3514 }
3515 }
3516 public:
3517 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3518 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3519 };
3520
3521 void InstanceKlass::verify_on(outputStream* st) {
3522 #ifndef PRODUCT
3523 // Avoid redundant verifies, this really should be in product.
3524 if (_verify_count == Universe::verify_count()) return;
3525 _verify_count = Universe::verify_count();
3526 #endif
3527
3528 // Verify Klass
3529 Klass::verify_on(st);
3530
3531 // Verify that klass is present in ClassLoaderData
3532 guarantee(class_loader_data()->contains_klass(this),
3533 "this class isn't found in class loader data");
3534
3535 // Verify vtables
3536 if (is_linked()) {
3537 // $$$ This used to be done only for m/s collections. Doing it
3538 // always seemed a valid generalization. (DLD -- 6/00)
3539 vtable().verify(st);
3540 }
3541
3542 // Verify first subklass
3543 if (subklass() != NULL) {
3544 guarantee(subklass()->is_klass(), "should be klass");
3545 }
3546
3547 // Verify siblings
3548 Klass* super = this->super();
3549 Klass* sib = next_sibling();
3550 if (sib != NULL) {
3551 if (sib == this) {
3552 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3553 }
3554
3555 guarantee(sib->is_klass(), "should be klass");
3556 guarantee(sib->super() == super, "siblings should have same superklass");
3557 }
3558
3559 // Verify implementor fields requires the Compile_lock, but this is sometimes
3560 // called inside a safepoint, so don't verify.
3561
3562 // Verify local interfaces
3563 if (local_interfaces()) {
3564 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
3565 for (int j = 0; j < local_interfaces->length(); j++) {
3566 InstanceKlass* e = local_interfaces->at(j);
3567 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3568 }
3569 }
3570
3571 // Verify transitive interfaces
3572 if (transitive_interfaces() != NULL) {
3573 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
3574 for (int j = 0; j < transitive_interfaces->length(); j++) {
3575 InstanceKlass* e = transitive_interfaces->at(j);
3576 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3577 }
3578 }
3579
3580 // Verify methods
3581 if (methods() != NULL) {
3582 Array<Method*>* methods = this->methods();
3583 for (int j = 0; j < methods->length(); j++) {
3584 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3585 }
3586 for (int j = 0; j < methods->length() - 1; j++) {
3587 Method* m1 = methods->at(j);
3588 Method* m2 = methods->at(j + 1);
3589 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3590 }
3591 }
3592
3593 // Verify method ordering
3594 if (method_ordering() != NULL) {
3595 Array<int>* method_ordering = this->method_ordering();
3596 int length = method_ordering->length();
3597 if (JvmtiExport::can_maintain_original_method_order() ||
3598 ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3599 guarantee(length == methods()->length(), "invalid method ordering length");
3600 jlong sum = 0;
3601 for (int j = 0; j < length; j++) {
3602 int original_index = method_ordering->at(j);
3603 guarantee(original_index >= 0, "invalid method ordering index");
3604 guarantee(original_index < length, "invalid method ordering index");
3605 sum += original_index;
3606 }
3607 // Verify sum of indices 0,1,...,length-1
3608 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3609 } else {
3610 guarantee(length == 0, "invalid method ordering length");
3611 }
3612 }
3613
3614 // Verify default methods
3615 if (default_methods() != NULL) {
3616 Array<Method*>* methods = this->default_methods();
3617 for (int j = 0; j < methods->length(); j++) {
3618 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3619 }
3620 for (int j = 0; j < methods->length() - 1; j++) {
3621 Method* m1 = methods->at(j);
3622 Method* m2 = methods->at(j + 1);
3623 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3624 }
3625 }
3626
3627 // Verify JNI static field identifiers
3628 if (jni_ids() != NULL) {
3629 jni_ids()->verify(this);
3630 }
3631
3632 // Verify other fields
3633 if (array_klasses() != NULL) {
3634 guarantee(array_klasses()->is_klass(), "should be klass");
3635 }
3636 if (constants() != NULL) {
3637 guarantee(constants()->is_constantPool(), "should be constant pool");
3638 }
3639 const Klass* anonymous_host = unsafe_anonymous_host();
3640 if (anonymous_host != NULL) {
3641 guarantee(anonymous_host->is_klass(), "should be klass");
3642 }
3643 }
3644
3645 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3646 Klass::oop_verify_on(obj, st);
3647 VerifyFieldClosure blk;
3648 obj->oop_iterate(&blk);
3649 }
3650
3651
3652 // JNIid class for jfieldIDs only
3653 // Note to reviewers:
3654 // These JNI functions are just moved over to column 1 and not changed
3655 // in the compressed oops workspace.
3656 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3657 _holder = holder;
3658 _offset = offset;
3659 _next = next;
3660 debug_only(_is_static_field_id = false;)
3661 }
3662
3663
3664 JNIid* JNIid::find(int offset) {
3665 JNIid* current = this;
3666 while (current != NULL) {
3667 if (current->offset() == offset) return current;
3668 current = current->next();
3669 }
3670 return NULL;
3671 }
3672
3673 void JNIid::deallocate(JNIid* current) {
3674 while (current != NULL) {
3675 JNIid* next = current->next();
3676 delete current;
3677 current = next;
3678 }
3679 }
3680
3681
3682 void JNIid::verify(Klass* holder) {
3683 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3684 int end_field_offset;
3685 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3686
3687 JNIid* current = this;
3688 while (current != NULL) {
3689 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3690 #ifdef ASSERT
3691 int o = current->offset();
3692 if (current->is_static_field_id()) {
3693 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3694 }
3695 #endif
3696 current = current->next();
3697 }
3698 }
3699
3700 #ifdef ASSERT
3701 void InstanceKlass::set_init_state(ClassState state) {
3702 bool good_state = is_shared() ? (_init_state <= state)
3703 : (_init_state < state);
3704 assert(good_state || state == allocated, "illegal state transition");
3705 _init_state = (u1)state;
3706 }
3707 #endif
3708
3709 #if INCLUDE_JVMTI
3710
3711 // RedefineClasses() support for previous versions
3712
3713 // Globally, there is at least one previous version of a class to walk
3714 // during class unloading, which is saved because old methods in the class
3715 // are still running. Otherwise the previous version list is cleaned up.
3716 bool InstanceKlass::_has_previous_versions = false;
3717
3718 // Returns true if there are previous versions of a class for class
3719 // unloading only. Also resets the flag to false. purge_previous_version
3720 // will set the flag to true if there are any left, i.e., if there's any
3721 // work to do for next time. This is to avoid the expensive code cache
3722 // walk in CLDG::clean_deallocate_lists().
3723 bool InstanceKlass::has_previous_versions_and_reset() {
3724 bool ret = _has_previous_versions;
3725 log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3726 ret ? "true" : "false");
3727 _has_previous_versions = false;
3728 return ret;
3729 }
3730
3731 // Purge previous versions before adding new previous versions of the class and
3732 // during class unloading.
3733 void InstanceKlass::purge_previous_version_list() {
3734 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3735 assert(has_been_redefined(), "Should only be called for main class");
3736
3737 // Quick exit.
3738 if (previous_versions() == NULL) {
3739 return;
3740 }
3741
3742 // This klass has previous versions so see what we can cleanup
3743 // while it is safe to do so.
3744
3745 int deleted_count = 0; // leave debugging breadcrumbs
3746 int live_count = 0;
3747 ClassLoaderData* loader_data = class_loader_data();
3748 assert(loader_data != NULL, "should never be null");
3749
3750 ResourceMark rm;
3751 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3752
3753 // previous versions are linked together through the InstanceKlass
3754 InstanceKlass* pv_node = previous_versions();
3755 InstanceKlass* last = this;
3756 int version = 0;
3757
3758 // check the previous versions list
3759 for (; pv_node != NULL; ) {
3760
3761 ConstantPool* pvcp = pv_node->constants();
3762 assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3763
3764 if (!pvcp->on_stack()) {
3765 // If the constant pool isn't on stack, none of the methods
3766 // are executing. Unlink this previous_version.
3767 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3768 // so will be deallocated during the next phase of class unloading.
3769 log_trace(redefine, class, iklass, purge)
3770 ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3771 // For debugging purposes.
3772 pv_node->set_is_scratch_class();
3773 // Unlink from previous version list.
3774 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3775 InstanceKlass* next = pv_node->previous_versions();
3776 pv_node->link_previous_versions(NULL); // point next to NULL
3777 last->link_previous_versions(next);
3778 // Add to the deallocate list after unlinking
3779 loader_data->add_to_deallocate_list(pv_node);
3780 pv_node = next;
3781 deleted_count++;
3782 version++;
3783 continue;
3784 } else {
3785 log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3786 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3787 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3788 live_count++;
3789 // found a previous version for next time we do class unloading
3790 _has_previous_versions = true;
3791 }
3792
3793 // At least one method is live in this previous version.
3794 // Reset dead EMCP methods not to get breakpoints.
3795 // All methods are deallocated when all of the methods for this class are no
3796 // longer running.
3797 Array<Method*>* method_refs = pv_node->methods();
3798 if (method_refs != NULL) {
3799 log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3800 for (int j = 0; j < method_refs->length(); j++) {
3801 Method* method = method_refs->at(j);
3802
3803 if (!method->on_stack()) {
3804 // no breakpoints for non-running methods
3805 if (method->is_running_emcp()) {
3806 method->set_running_emcp(false);
3807 }
3808 } else {
3809 assert (method->is_obsolete() || method->is_running_emcp(),
3810 "emcp method cannot run after emcp bit is cleared");
3811 log_trace(redefine, class, iklass, purge)
3812 ("purge: %s(%s): prev method @%d in version @%d is alive",
3813 method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3814 }
3815 }
3816 }
3817 // next previous version
3818 last = pv_node;
3819 pv_node = pv_node->previous_versions();
3820 version++;
3821 }
3822 log_trace(redefine, class, iklass, purge)
3823 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3824 }
3825
3826 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3827 int emcp_method_count) {
3828 int obsolete_method_count = old_methods->length() - emcp_method_count;
3829
3830 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3831 _previous_versions != NULL) {
3832 // We have a mix of obsolete and EMCP methods so we have to
3833 // clear out any matching EMCP method entries the hard way.
3834 int local_count = 0;
3835 for (int i = 0; i < old_methods->length(); i++) {
3836 Method* old_method = old_methods->at(i);
3837 if (old_method->is_obsolete()) {
3838 // only obsolete methods are interesting
3839 Symbol* m_name = old_method->name();
3840 Symbol* m_signature = old_method->signature();
3841
3842 // previous versions are linked together through the InstanceKlass
3843 int j = 0;
3844 for (InstanceKlass* prev_version = _previous_versions;
3845 prev_version != NULL;
3846 prev_version = prev_version->previous_versions(), j++) {
3847
3848 Array<Method*>* method_refs = prev_version->methods();
3849 for (int k = 0; k < method_refs->length(); k++) {
3850 Method* method = method_refs->at(k);
3851
3852 if (!method->is_obsolete() &&
3853 method->name() == m_name &&
3854 method->signature() == m_signature) {
3855 // The current RedefineClasses() call has made all EMCP
3856 // versions of this method obsolete so mark it as obsolete
3857 log_trace(redefine, class, iklass, add)
3858 ("%s(%s): flush obsolete method @%d in version @%d",
3859 m_name->as_C_string(), m_signature->as_C_string(), k, j);
3860
3861 method->set_is_obsolete();
3862 break;
3863 }
3864 }
3865
3866 // The previous loop may not find a matching EMCP method, but
3867 // that doesn't mean that we can optimize and not go any
3868 // further back in the PreviousVersion generations. The EMCP
3869 // method for this generation could have already been made obsolete,
3870 // but there still may be an older EMCP method that has not
3871 // been made obsolete.
3872 }
3873
3874 if (++local_count >= obsolete_method_count) {
3875 // no more obsolete methods so bail out now
3876 break;
3877 }
3878 }
3879 }
3880 }
3881 }
3882
3883 // Save the scratch_class as the previous version if any of the methods are running.
3884 // The previous_versions are used to set breakpoints in EMCP methods and they are
3885 // also used to clean MethodData links to redefined methods that are no longer running.
3886 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3887 int emcp_method_count) {
3888 assert(Thread::current()->is_VM_thread(),
3889 "only VMThread can add previous versions");
3890
3891 ResourceMark rm;
3892 log_trace(redefine, class, iklass, add)
3893 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3894
3895 // Clean out old previous versions for this class
3896 purge_previous_version_list();
3897
3898 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
3899 // a previous redefinition may be made obsolete by this redefinition.
3900 Array<Method*>* old_methods = scratch_class->methods();
3901 mark_newly_obsolete_methods(old_methods, emcp_method_count);
3902
3903 // If the constant pool for this previous version of the class
3904 // is not marked as being on the stack, then none of the methods
3905 // in this previous version of the class are on the stack so
3906 // we don't need to add this as a previous version.
3907 ConstantPool* cp_ref = scratch_class->constants();
3908 if (!cp_ref->on_stack()) {
3909 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3910 // For debugging purposes.
3911 scratch_class->set_is_scratch_class();
3912 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3913 return;
3914 }
3915
3916 if (emcp_method_count != 0) {
3917 // At least one method is still running, check for EMCP methods
3918 for (int i = 0; i < old_methods->length(); i++) {
3919 Method* old_method = old_methods->at(i);
3920 if (!old_method->is_obsolete() && old_method->on_stack()) {
3921 // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3922 // we can add breakpoints for it.
3923
3924 // We set the method->on_stack bit during safepoints for class redefinition
3925 // and use this bit to set the is_running_emcp bit.
3926 // After the safepoint, the on_stack bit is cleared and the running emcp
3927 // method may exit. If so, we would set a breakpoint in a method that
3928 // is never reached, but this won't be noticeable to the programmer.
3929 old_method->set_running_emcp(true);
3930 log_trace(redefine, class, iklass, add)
3931 ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3932 } else if (!old_method->is_obsolete()) {
3933 log_trace(redefine, class, iklass, add)
3934 ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3935 }
3936 }
3937 }
3938
3939 // Add previous version if any methods are still running.
3940 // Set has_previous_version flag for processing during class unloading.
3941 _has_previous_versions = true;
3942 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3943 assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3944 scratch_class->link_previous_versions(previous_versions());
3945 link_previous_versions(scratch_class);
3946 } // end add_previous_version()
3947
3948 #endif // INCLUDE_JVMTI
3949
3950 Method* InstanceKlass::method_with_idnum(int idnum) {
3951 Method* m = NULL;
3952 if (idnum < methods()->length()) {
3953 m = methods()->at(idnum);
3954 }
3955 if (m == NULL || m->method_idnum() != idnum) {
3956 for (int index = 0; index < methods()->length(); ++index) {
3957 m = methods()->at(index);
3958 if (m->method_idnum() == idnum) {
3959 return m;
3960 }
3961 }
3962 // None found, return null for the caller to handle.
3963 return NULL;
3964 }
3965 return m;
3966 }
3967
3968
3969 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3970 if (idnum >= methods()->length()) {
3971 return NULL;
3972 }
3973 Method* m = methods()->at(idnum);
3974 if (m != NULL && m->orig_method_idnum() == idnum) {
3975 return m;
3976 }
3977 // Obsolete method idnum does not match the original idnum
3978 for (int index = 0; index < methods()->length(); ++index) {
3979 m = methods()->at(index);
3980 if (m->orig_method_idnum() == idnum) {
3981 return m;
3982 }
3983 }
3984 // None found, return null for the caller to handle.
3985 return NULL;
3986 }
3987
3988
3989 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3990 InstanceKlass* holder = get_klass_version(version);
3991 if (holder == NULL) {
3992 return NULL; // The version of klass is gone, no method is found
3993 }
3994 Method* method = holder->method_with_orig_idnum(idnum);
3995 return method;
3996 }
3997
3998 #if INCLUDE_JVMTI
3999 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4000 if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
4001 // Ignore the archived class stream data
4002 return NULL;
4003 } else {
4004 return _cached_class_file;
4005 }
4006 }
4007
4008 jint InstanceKlass::get_cached_class_file_len() {
4009 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4010 }
4011
4012 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4013 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4014 }
4015
4016 #if INCLUDE_CDS
4017 JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() {
4018 if (DumpSharedSpaces) {
4019 return _cached_class_file;
4020 } else {
4021 assert(this->is_shared(), "class should be shared");
4022 if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
4023 return _cached_class_file;
4024 } else {
4025 return NULL;
4026 }
4027 }
4028 }
4029 #endif
4030 #endif