1 /*
2 * Copyright (c) 1997, 2024, 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 "cds/archiveUtils.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/classListWriter.hpp"
29 #include "cds/heapShared.hpp"
30 #include "cds/metaspaceShared.hpp"
31 #include "classfile/classFileParser.hpp"
32 #include "classfile/classFileStream.hpp"
33 #include "classfile/classLoader.hpp"
34 #include "classfile/classLoaderData.inline.hpp"
35 #include "classfile/javaClasses.hpp"
36 #include "classfile/moduleEntry.hpp"
37 #include "classfile/systemDictionary.hpp"
38 #include "classfile/systemDictionaryShared.hpp"
39 #include "classfile/verifier.hpp"
40 #include "classfile/vmClasses.hpp"
41 #include "classfile/vmSymbols.hpp"
42 #include "code/codeCache.hpp"
43 #include "code/dependencyContext.hpp"
44 #include "compiler/compilationPolicy.hpp"
45 #include "compiler/compileBroker.hpp"
46 #include "gc/shared/collectedHeap.inline.hpp"
47 #include "interpreter/bytecodeStream.hpp"
48 #include "interpreter/oopMapCache.hpp"
49 #include "interpreter/rewriter.hpp"
50 #include "jvm.h"
51 #include "jvmtifiles/jvmti.h"
52 #include "logging/log.hpp"
53 #include "logging/logMessage.hpp"
54 #include "logging/logStream.hpp"
55 #include "memory/allocation.inline.hpp"
56 #include "memory/iterator.inline.hpp"
57 #include "memory/metadataFactory.hpp"
58 #include "memory/metaspaceClosure.hpp"
59 #include "memory/oopFactory.hpp"
60 #include "memory/resourceArea.hpp"
61 #include "memory/universe.hpp"
62 #include "oops/fieldStreams.inline.hpp"
63 #include "oops/constantPool.hpp"
64 #include "oops/instanceClassLoaderKlass.hpp"
65 #include "oops/instanceKlass.inline.hpp"
66 #include "oops/instanceMirrorKlass.hpp"
67 #include "oops/instanceOop.hpp"
68 #include "oops/instanceStackChunkKlass.hpp"
69 #include "oops/klass.inline.hpp"
70 #include "oops/method.hpp"
71 #include "oops/oop.inline.hpp"
72 #include "oops/recordComponent.hpp"
73 #include "oops/symbol.hpp"
74 #include "prims/jvmtiExport.hpp"
75 #include "prims/jvmtiRedefineClasses.hpp"
76 #include "prims/jvmtiThreadState.hpp"
77 #include "prims/methodComparator.hpp"
78 #include "runtime/arguments.hpp"
79 #include "runtime/deoptimization.hpp"
80 #include "runtime/atomic.hpp"
81 #include "runtime/fieldDescriptor.inline.hpp"
82 #include "runtime/handles.inline.hpp"
83 #include "runtime/javaCalls.hpp"
84 #include "runtime/javaThread.inline.hpp"
85 #include "runtime/mutexLocker.hpp"
86 #include "runtime/orderAccess.hpp"
87 #include "runtime/os.inline.hpp"
88 #include "runtime/reflection.hpp"
89 #include "runtime/threads.hpp"
90 #include "services/classLoadingService.hpp"
91 #include "services/finalizerService.hpp"
92 #include "services/threadService.hpp"
93 #include "utilities/dtrace.hpp"
94 #include "utilities/events.hpp"
95 #include "utilities/macros.hpp"
96 #include "utilities/stringUtils.hpp"
97 #include "utilities/pair.hpp"
98 #ifdef COMPILER1
99 #include "c1/c1_Compiler.hpp"
100 #endif
101 #if INCLUDE_JFR
102 #include "jfr/jfrEvents.hpp"
103 #endif
104
105 #ifdef DTRACE_ENABLED
106
107
108 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
109 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
110 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
111 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
112 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
113 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
114 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
115 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
116 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
117 { \
118 char* data = nullptr; \
119 int len = 0; \
120 Symbol* clss_name = name(); \
121 if (clss_name != nullptr) { \
122 data = (char*)clss_name->bytes(); \
123 len = clss_name->utf8_length(); \
124 } \
125 HOTSPOT_CLASS_INITIALIZATION_##type( \
126 data, len, (void*)class_loader(), thread_type); \
127 }
128
129 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
130 { \
131 char* data = nullptr; \
132 int len = 0; \
133 Symbol* clss_name = name(); \
134 if (clss_name != nullptr) { \
135 data = (char*)clss_name->bytes(); \
136 len = clss_name->utf8_length(); \
137 } \
138 HOTSPOT_CLASS_INITIALIZATION_##type( \
139 data, len, (void*)class_loader(), thread_type, wait); \
140 }
141
142 #else // ndef DTRACE_ENABLED
143
144 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
145 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
146
147 #endif // ndef DTRACE_ENABLED
148
149 bool InstanceKlass::_finalization_enabled = true;
150
151 static inline bool is_class_loader(const Symbol* class_name,
152 const ClassFileParser& parser) {
153 assert(class_name != nullptr, "invariant");
154
155 if (class_name == vmSymbols::java_lang_ClassLoader()) {
156 return true;
157 }
158
159 if (vmClasses::ClassLoader_klass_loaded()) {
160 const Klass* const super_klass = parser.super_klass();
161 if (super_klass != nullptr) {
162 if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
163 return true;
164 }
165 }
166 }
167 return false;
168 }
169
170 static inline bool is_stack_chunk_class(const Symbol* class_name,
171 const ClassLoaderData* loader_data) {
172 return (class_name == vmSymbols::jdk_internal_vm_StackChunk() &&
173 loader_data->is_the_null_class_loader_data());
174 }
175
176 // private: called to verify that k is a static member of this nest.
177 // We know that k is an instance class in the same package and hence the
178 // same classloader.
179 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
180 assert(!is_hidden(), "unexpected hidden class");
181 if (_nest_members == nullptr || _nest_members == Universe::the_empty_short_array()) {
182 if (log_is_enabled(Trace, class, nestmates)) {
183 ResourceMark rm(current);
184 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
185 k->external_name(), this->external_name());
186 }
187 return false;
188 }
189
190 if (log_is_enabled(Trace, class, nestmates)) {
191 ResourceMark rm(current);
192 log_trace(class, nestmates)("Checking nest membership of %s in %s",
193 k->external_name(), this->external_name());
194 }
195
196 // Check for the named class in _nest_members.
197 // We don't resolve, or load, any classes.
198 for (int i = 0; i < _nest_members->length(); i++) {
199 int cp_index = _nest_members->at(i);
200 Symbol* name = _constants->klass_name_at(cp_index);
201 if (name == k->name()) {
202 log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
203 return true;
204 }
205 }
206 log_trace(class, nestmates)("- class is NOT a nest member!");
207 return false;
208 }
209
210 // Called to verify that k is a permitted subclass of this class
211 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k) const {
212 Thread* current = Thread::current();
213 assert(k != nullptr, "sanity check");
214 assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
215 "unexpected empty _permitted_subclasses array");
216
217 if (log_is_enabled(Trace, class, sealed)) {
218 ResourceMark rm(current);
219 log_trace(class, sealed)("Checking for permitted subclass of %s in %s",
220 k->external_name(), this->external_name());
221 }
222
223 // Check that the class and its super are in the same module.
224 if (k->module() != this->module()) {
225 ResourceMark rm(current);
226 log_trace(class, sealed)("Check failed for same module of permitted subclass %s and sealed class %s",
227 k->external_name(), this->external_name());
228 return false;
229 }
230
231 if (!k->is_public() && !is_same_class_package(k)) {
232 ResourceMark rm(current);
233 log_trace(class, sealed)("Check failed, subclass %s not public and not in the same package as sealed class %s",
234 k->external_name(), this->external_name());
235 return false;
236 }
237
238 for (int i = 0; i < _permitted_subclasses->length(); i++) {
239 int cp_index = _permitted_subclasses->at(i);
240 Symbol* name = _constants->klass_name_at(cp_index);
241 if (name == k->name()) {
242 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
243 return true;
244 }
245 }
246 log_trace(class, sealed)("- class is NOT a permitted subclass!");
247 return false;
248 }
249
250 // Return nest-host class, resolving, validating and saving it if needed.
251 // In cases where this is called from a thread that cannot do classloading
252 // (such as a native JIT thread) then we simply return null, which in turn
253 // causes the access check to return false. Such code will retry the access
254 // from a more suitable environment later. Otherwise the _nest_host is always
255 // set once this method returns.
256 // Any errors from nest-host resolution must be preserved so they can be queried
257 // from higher-level access checking code, and reported as part of access checking
258 // exceptions.
259 // VirtualMachineErrors are propagated with a null return.
260 // Under any conditions where the _nest_host can be set to non-null the resulting
261 // value of it and, if applicable, the nest host resolution/validation error,
262 // are idempotent.
263 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
264 InstanceKlass* nest_host_k = _nest_host;
265 if (nest_host_k != nullptr) {
266 return nest_host_k;
267 }
268
269 ResourceMark rm(THREAD);
270
271 // need to resolve and save our nest-host class.
272 if (_nest_host_index != 0) { // we have a real nest_host
273 // Before trying to resolve check if we're in a suitable context
274 bool can_resolve = THREAD->can_call_java();
275 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
276 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
277 this->external_name());
278 return nullptr; // sentinel to say "try again from a different context"
279 }
280
281 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
282 this->external_name(),
283 _constants->klass_name_at(_nest_host_index)->as_C_string());
284
285 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
286 if (HAS_PENDING_EXCEPTION) {
287 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
288 return nullptr; // propagate VMEs
289 }
290 stringStream ss;
291 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
292 ss.print("Nest host resolution of %s with host %s failed: ",
293 this->external_name(), target_host_class);
294 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
295 const char* msg = ss.as_string(true /* on C-heap */);
296 constantPoolHandle cph(THREAD, constants());
297 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
298 CLEAR_PENDING_EXCEPTION;
299
300 log_trace(class, nestmates)("%s", msg);
301 } else {
302 // A valid nest-host is an instance class in the current package that lists this
303 // class as a nest member. If any of these conditions are not met the class is
304 // its own nest-host.
305 const char* error = nullptr;
306
307 // JVMS 5.4.4 indicates package check comes first
308 if (is_same_class_package(k)) {
309 // Now check actual membership. We can't be a member if our "host" is
310 // not an instance class.
311 if (k->is_instance_klass()) {
312 nest_host_k = InstanceKlass::cast(k);
313 bool is_member = nest_host_k->has_nest_member(THREAD, this);
314 if (is_member) {
315 _nest_host = nest_host_k; // save resolved nest-host value
316
317 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
318 this->external_name(), k->external_name());
319 return nest_host_k;
320 } else {
321 error = "current type is not listed as a nest member";
322 }
323 } else {
324 error = "host is not an instance class";
325 }
326 } else {
327 error = "types are in different packages";
328 }
329
330 // something went wrong, so record what and log it
331 {
332 stringStream ss;
333 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
334 this->external_name(),
335 this->class_loader_data()->loader_name_and_id(),
336 k->external_name(),
337 k->class_loader_data()->loader_name_and_id(),
338 error);
339 const char* msg = ss.as_string(true /* on C-heap */);
340 constantPoolHandle cph(THREAD, constants());
341 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
342 log_trace(class, nestmates)("%s", msg);
343 }
344 }
345 } else {
346 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
347 this->external_name());
348 }
349
350 // Either not in an explicit nest, or else an error occurred, so
351 // the nest-host is set to `this`. Any thread that sees this assignment
352 // will also see any setting of nest_host_error(), if applicable.
353 return (_nest_host = this);
354 }
355
356 // Dynamic nest member support: set this class's nest host to the given class.
357 // This occurs as part of the class definition, as soon as the instanceKlass
358 // has been created and doesn't require further resolution. The code:
359 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
360 // results in:
361 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
362 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
363 // We also know the "host" is a valid nest-host in the same package so we can
364 // assert some of those facts.
365 void InstanceKlass::set_nest_host(InstanceKlass* host) {
366 assert(is_hidden(), "must be a hidden class");
367 assert(host != nullptr, "null nest host specified");
368 assert(_nest_host == nullptr, "current class has resolved nest-host");
369 assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
370 nest_host_error());
371 assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
372 (host->_nest_host == host), "proposed host is not a valid nest-host");
373 // Can't assert this as package is not set yet:
374 // assert(is_same_class_package(host), "proposed host is in wrong package");
375
376 if (log_is_enabled(Trace, class, nestmates)) {
377 ResourceMark rm;
378 const char* msg = "";
379 // a hidden class does not expect a statically defined nest-host
380 if (_nest_host_index > 0) {
381 msg = "(the NestHost attribute in the current class is ignored)";
382 } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
383 msg = "(the NestMembers attribute in the current class is ignored)";
384 }
385 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
386 this->external_name(),
387 host->external_name(),
388 msg);
389 }
390 // set dynamic nest host
391 _nest_host = host;
392 // Record dependency to keep nest host from being unloaded before this class.
393 ClassLoaderData* this_key = class_loader_data();
394 assert(this_key != nullptr, "sanity");
395 this_key->record_dependency(host);
396 }
397
398 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
399 // or we are k's nest_host - all of which is covered by comparing the two
400 // resolved_nest_hosts.
401 // Any exceptions (i.e. VMEs) are propagated.
402 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
403
404 assert(this != k, "this should be handled by higher-level code");
405
406 // Per JVMS 5.4.4 we first resolve and validate the current class, then
407 // the target class k.
408
409 InstanceKlass* cur_host = nest_host(CHECK_false);
410 if (cur_host == nullptr) {
411 return false;
412 }
413
414 Klass* k_nest_host = k->nest_host(CHECK_false);
415 if (k_nest_host == nullptr) {
416 return false;
417 }
418
419 bool access = (cur_host == k_nest_host);
420
421 ResourceMark rm(THREAD);
422 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
423 this->external_name(),
424 access ? "" : "NOT ",
425 k->external_name());
426 return access;
427 }
428
429 const char* InstanceKlass::nest_host_error() {
430 if (_nest_host_index == 0) {
431 return nullptr;
432 } else {
433 constantPoolHandle cph(Thread::current(), constants());
434 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
435 }
436 }
437
438 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
439 const int size = InstanceKlass::size(parser.vtable_size(),
440 parser.itable_size(),
441 nonstatic_oop_map_size(parser.total_oop_map_count()),
442 parser.is_interface());
443
444 const Symbol* const class_name = parser.class_name();
445 assert(class_name != nullptr, "invariant");
446 ClassLoaderData* loader_data = parser.loader_data();
447 assert(loader_data != nullptr, "invariant");
448
449 InstanceKlass* ik;
450
451 // Allocation
452 if (parser.is_instance_ref_klass()) {
453 // java.lang.ref.Reference
454 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
455 } else if (class_name == vmSymbols::java_lang_Class()) {
456 // mirror - java.lang.Class
457 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
458 } else if (is_stack_chunk_class(class_name, loader_data)) {
459 // stack chunk
460 ik = new (loader_data, size, THREAD) InstanceStackChunkKlass(parser);
461 } else if (is_class_loader(class_name, parser)) {
462 // class loader - java.lang.ClassLoader
463 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
464 } else {
465 // normal
466 ik = new (loader_data, size, THREAD) InstanceKlass(parser);
467 }
468
469 // Check for pending exception before adding to the loader data and incrementing
470 // class count. Can get OOM here.
471 if (HAS_PENDING_EXCEPTION) {
472 return nullptr;
473 }
474
475 return ik;
476 }
477
478
479 // copy method ordering from resource area to Metaspace
480 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
481 if (m != nullptr) {
482 // allocate a new array and copy contents (memcpy?)
483 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
484 for (int i = 0; i < m->length(); i++) {
485 _method_ordering->at_put(i, m->at(i));
486 }
487 } else {
488 _method_ordering = Universe::the_empty_int_array();
489 }
490 }
491
492 // create a new array of vtable_indices for default methods
493 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
494 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
495 assert(default_vtable_indices() == nullptr, "only create once");
496 set_default_vtable_indices(vtable_indices);
497 return vtable_indices;
498 }
499
500 static Monitor* create_init_monitor(const char* name) {
501 return new Monitor(Mutex::safepoint, name);
502 }
503
504 InstanceKlass::InstanceKlass() {
505 assert(CDSConfig::is_dumping_static_archive() || UseSharedSpaces, "only for CDS");
506 }
507
508 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, ReferenceType reference_type) :
509 Klass(kind),
510 _nest_members(nullptr),
511 _nest_host(nullptr),
512 _permitted_subclasses(nullptr),
513 _record_components(nullptr),
514 _static_field_size(parser.static_field_size()),
515 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
516 _itable_len(parser.itable_size()),
517 _nest_host_index(0),
518 _init_state(allocated),
519 _reference_type(reference_type),
520 _init_monitor(create_init_monitor("InstanceKlassInitMonitor_lock")),
521 _init_thread(nullptr)
522 {
523 set_vtable_length(parser.vtable_size());
524 set_access_flags(parser.access_flags());
525 if (parser.is_hidden()) set_is_hidden();
526 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
527 false));
528
529 assert(nullptr == _methods, "underlying memory not zeroed?");
530 assert(is_instance_klass(), "is layout incorrect?");
531 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
532 }
533
534 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
535 Array<Method*>* methods) {
536 if (methods != nullptr && methods != Universe::the_empty_method_array() &&
537 !methods->is_shared()) {
538 for (int i = 0; i < methods->length(); i++) {
539 Method* method = methods->at(i);
540 if (method == nullptr) continue; // maybe null if error processing
541 // Only want to delete methods that are not executing for RedefineClasses.
542 // The previous version will point to them so they're not totally dangling
543 assert (!method->on_stack(), "shouldn't be called with methods on stack");
544 MetadataFactory::free_metadata(loader_data, method);
545 }
546 MetadataFactory::free_array<Method*>(loader_data, methods);
547 }
548 }
549
550 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
551 const Klass* super_klass,
552 Array<InstanceKlass*>* local_interfaces,
553 Array<InstanceKlass*>* transitive_interfaces) {
554 // Only deallocate transitive interfaces if not empty, same as super class
555 // or same as local interfaces. See code in parseClassFile.
556 Array<InstanceKlass*>* ti = transitive_interfaces;
557 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
558 // check that the interfaces don't come from super class
559 Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
560 InstanceKlass::cast(super_klass)->transitive_interfaces();
561 if (ti != sti && ti != nullptr && !ti->is_shared()) {
562 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
563 }
564 }
565
566 // local interfaces can be empty
567 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
568 local_interfaces != nullptr && !local_interfaces->is_shared()) {
569 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
570 }
571 }
572
573 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
574 Array<RecordComponent*>* record_components) {
575 if (record_components != nullptr && !record_components->is_shared()) {
576 for (int i = 0; i < record_components->length(); i++) {
577 RecordComponent* record_component = record_components->at(i);
578 MetadataFactory::free_metadata(loader_data, record_component);
579 }
580 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
581 }
582 }
583
584 // This function deallocates the metadata and C heap pointers that the
585 // InstanceKlass points to.
586 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
587 // Orphan the mirror first, CMS thinks it's still live.
588 if (java_mirror() != nullptr) {
589 java_lang_Class::set_klass(java_mirror(), nullptr);
590 }
591
592 // Also remove mirror from handles
593 loader_data->remove_handle(_java_mirror);
594
595 // Need to take this class off the class loader data list.
596 loader_data->remove_class(this);
597
598 // The array_klass for this class is created later, after error handling.
599 // For class redefinition, we keep the original class so this scratch class
600 // doesn't have an array class. Either way, assert that there is nothing
601 // to deallocate.
602 assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
603
604 // Release C heap allocated data that this points to, which includes
605 // reference counting symbol names.
606 // Can't release the constant pool or MethodData C heap data here because the constant
607 // pool can be deallocated separately from the InstanceKlass for default methods and
608 // redefine classes. MethodData can also be released separately.
609 release_C_heap_structures(/* release_sub_metadata */ false);
610
611 deallocate_methods(loader_data, methods());
612 set_methods(nullptr);
613
614 deallocate_record_components(loader_data, record_components());
615 set_record_components(nullptr);
616
617 if (method_ordering() != nullptr &&
618 method_ordering() != Universe::the_empty_int_array() &&
619 !method_ordering()->is_shared()) {
620 MetadataFactory::free_array<int>(loader_data, method_ordering());
621 }
622 set_method_ordering(nullptr);
623
624 // default methods can be empty
625 if (default_methods() != nullptr &&
626 default_methods() != Universe::the_empty_method_array() &&
627 !default_methods()->is_shared()) {
628 MetadataFactory::free_array<Method*>(loader_data, default_methods());
629 }
630 // Do NOT deallocate the default methods, they are owned by superinterfaces.
631 set_default_methods(nullptr);
632
633 // default methods vtable indices can be empty
634 if (default_vtable_indices() != nullptr &&
635 !default_vtable_indices()->is_shared()) {
636 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
637 }
638 set_default_vtable_indices(nullptr);
639
640
641 // This array is in Klass, but remove it with the InstanceKlass since
642 // this place would be the only caller and it can share memory with transitive
643 // interfaces.
644 if (secondary_supers() != nullptr &&
645 secondary_supers() != Universe::the_empty_klass_array() &&
646 // see comments in compute_secondary_supers about the following cast
647 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
648 !secondary_supers()->is_shared()) {
649 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
650 }
651 set_secondary_supers(nullptr);
652
653 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
654 set_transitive_interfaces(nullptr);
655 set_local_interfaces(nullptr);
656
657 if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->is_shared()) {
658 MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
659 }
660 set_fieldinfo_stream(nullptr);
661
662 if (fields_status() != nullptr && !fields_status()->is_shared()) {
663 MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
664 }
665 set_fields_status(nullptr);
666
667 // If a method from a redefined class is using this constant pool, don't
668 // delete it, yet. The new class's previous version will point to this.
669 if (constants() != nullptr) {
670 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
671 if (!constants()->is_shared()) {
672 MetadataFactory::free_metadata(loader_data, constants());
673 }
674 // Delete any cached resolution errors for the constant pool
675 SystemDictionary::delete_resolution_error(constants());
676
677 set_constants(nullptr);
678 }
679
680 if (inner_classes() != nullptr &&
681 inner_classes() != Universe::the_empty_short_array() &&
682 !inner_classes()->is_shared()) {
683 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
684 }
685 set_inner_classes(nullptr);
686
687 if (nest_members() != nullptr &&
688 nest_members() != Universe::the_empty_short_array() &&
689 !nest_members()->is_shared()) {
690 MetadataFactory::free_array<jushort>(loader_data, nest_members());
691 }
692 set_nest_members(nullptr);
693
694 if (permitted_subclasses() != nullptr &&
695 permitted_subclasses() != Universe::the_empty_short_array() &&
696 !permitted_subclasses()->is_shared()) {
697 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
698 }
699 set_permitted_subclasses(nullptr);
700
701 // We should deallocate the Annotations instance if it's not in shared spaces.
702 if (annotations() != nullptr && !annotations()->is_shared()) {
703 MetadataFactory::free_metadata(loader_data, annotations());
704 }
705 set_annotations(nullptr);
706
707 SystemDictionaryShared::handle_class_unloading(this);
708
709 #if INCLUDE_CDS_JAVA_HEAP
710 if (CDSConfig::is_dumping_heap()) {
711 HeapShared::remove_scratch_objects(this);
712 }
713 #endif
714 }
715
716 bool InstanceKlass::is_record() const {
717 return _record_components != nullptr &&
718 is_final() &&
719 java_super() == vmClasses::Record_klass();
720 }
721
722 bool InstanceKlass::is_sealed() const {
723 return _permitted_subclasses != nullptr &&
724 _permitted_subclasses != Universe::the_empty_short_array();
725 }
726
727 bool InstanceKlass::should_be_initialized() const {
728 return !is_initialized();
729 }
730
731 klassItable InstanceKlass::itable() const {
732 return klassItable(const_cast<InstanceKlass*>(this));
733 }
734
735 // JVMTI spec thinks there are signers and protection domain in the
736 // instanceKlass. These accessors pretend these fields are there.
737 // The hprof specification also thinks these fields are in InstanceKlass.
738 oop InstanceKlass::protection_domain() const {
739 // return the protection_domain from the mirror
740 return java_lang_Class::protection_domain(java_mirror());
741 }
742
743 objArrayOop InstanceKlass::signers() const {
744 // return the signers from the mirror
745 return java_lang_Class::signers(java_mirror());
746 }
747
748 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
749 // process. The step comments refers to the procedure described in that section.
750 // Note: implementation moved to static method to expose the this pointer.
751 void InstanceKlass::initialize(TRAPS) {
752 if (this->should_be_initialized()) {
753 initialize_impl(CHECK);
754 // Note: at this point the class may be initialized
755 // OR it may be in the state of being initialized
756 // in case of recursive initialization!
757 } else {
758 assert(is_initialized(), "sanity check");
759 }
760 }
761
762
763 bool InstanceKlass::verify_code(TRAPS) {
764 // 1) Verify the bytecodes
765 return Verifier::verify(this, should_verify_class(), THREAD);
766 }
767
768 void InstanceKlass::link_class(TRAPS) {
769 assert(is_loaded(), "must be loaded");
770 if (!is_linked()) {
771 link_class_impl(CHECK);
772 }
773 }
774
775 void InstanceKlass::check_link_state_and_wait(JavaThread* current) {
776 MonitorLocker ml(current, _init_monitor);
777
778 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
779
780 // Another thread is linking this class, wait.
781 while (is_being_linked() && !is_init_thread(current)) {
782 if (debug_logging_enabled) {
783 ResourceMark rm(current);
784 log_debug(class, init)("Thread \"%s\" waiting for linking of %s by thread \"%s\"",
785 current->name(), external_name(), init_thread_name());
786 }
787 ml.wait();
788 }
789
790 // This thread is recursively linking this class, continue
791 if (is_being_linked() && is_init_thread(current)) {
792 if (debug_logging_enabled) {
793 ResourceMark rm(current);
794 log_debug(class, init)("Thread \"%s\" recursively linking %s",
795 current->name(), external_name());
796 }
797 return;
798 }
799
800 // If this class wasn't linked already, set state to being_linked
801 if (!is_linked()) {
802 if (debug_logging_enabled) {
803 ResourceMark rm(current);
804 log_debug(class, init)("Thread \"%s\" linking %s",
805 current->name(), external_name());
806 }
807 set_init_state(being_linked);
808 set_init_thread(current);
809 } else {
810 if (debug_logging_enabled) {
811 ResourceMark rm(current);
812 log_debug(class, init)("Thread \"%s\" found %s already linked",
813 current->name(), external_name());
814 }
815 }
816 }
817
818 // Called to verify that a class can link during initialization, without
819 // throwing a VerifyError.
820 bool InstanceKlass::link_class_or_fail(TRAPS) {
821 assert(is_loaded(), "must be loaded");
822 if (!is_linked()) {
823 link_class_impl(CHECK_false);
824 }
825 return is_linked();
826 }
827
828 bool InstanceKlass::link_class_impl(TRAPS) {
829 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
830 // This is for CDS static dump only -- we use the in_error_state to indicate that
831 // the class has failed verification. Throwing the NoClassDefFoundError here is just
832 // a convenient way to stop repeat attempts to verify the same (bad) class.
833 //
834 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
835 // if we are executing Java code. This is not a problem for CDS dumping phase since
836 // it doesn't execute any Java code.
837 ResourceMark rm(THREAD);
838 Exceptions::fthrow(THREAD_AND_LOCATION,
839 vmSymbols::java_lang_NoClassDefFoundError(),
840 "Class %s, or one of its supertypes, failed class initialization",
841 external_name());
842 return false;
843 }
844 // return if already verified
845 if (is_linked()) {
846 return true;
847 }
848
849 // Timing
850 // timer handles recursion
851 JavaThread* jt = THREAD;
852
853 // link super class before linking this class
854 Klass* super_klass = super();
855 if (super_klass != nullptr) {
856 if (super_klass->is_interface()) { // check if super class is an interface
857 ResourceMark rm(THREAD);
858 Exceptions::fthrow(
859 THREAD_AND_LOCATION,
860 vmSymbols::java_lang_IncompatibleClassChangeError(),
861 "class %s has interface %s as super class",
862 external_name(),
863 super_klass->external_name()
864 );
865 return false;
866 }
867
868 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
869 ik_super->link_class_impl(CHECK_false);
870 }
871
872 // link all interfaces implemented by this class before linking this class
873 Array<InstanceKlass*>* interfaces = local_interfaces();
874 int num_interfaces = interfaces->length();
875 for (int index = 0; index < num_interfaces; index++) {
876 InstanceKlass* interk = interfaces->at(index);
877 interk->link_class_impl(CHECK_false);
878 }
879
880 // in case the class is linked in the process of linking its superclasses
881 if (is_linked()) {
882 return true;
883 }
884
885 // trace only the link time for this klass that includes
886 // the verification time
887 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
888 ClassLoader::perf_class_link_selftime(),
889 ClassLoader::perf_classes_linked(),
890 jt->get_thread_stat()->perf_recursion_counts_addr(),
891 jt->get_thread_stat()->perf_timers_addr(),
892 PerfClassTraceTime::CLASS_LINK);
893
894 // verification & rewriting
895 {
896 LockLinkState init_lock(this, jt);
897
898 // rewritten will have been set if loader constraint error found
899 // on an earlier link attempt
900 // don't verify or rewrite if already rewritten
901 //
902
903 if (!is_linked()) {
904 if (!is_rewritten()) {
905 if (is_shared()) {
906 assert(!verified_at_dump_time(), "must be");
907 }
908 {
909 bool verify_ok = verify_code(THREAD);
910 if (!verify_ok) {
911 return false;
912 }
913 }
914
915 // Just in case a side-effect of verify linked this class already
916 // (which can sometimes happen since the verifier loads classes
917 // using custom class loaders, which are free to initialize things)
918 if (is_linked()) {
919 return true;
920 }
921
922 // also sets rewritten
923 rewrite_class(CHECK_false);
924 } else if (is_shared()) {
925 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
926 }
927
928 // relocate jsrs and link methods after they are all rewritten
929 link_methods(CHECK_false);
930
931 // Initialize the vtable and interface table after
932 // methods have been rewritten since rewrite may
933 // fabricate new Method*s.
934 // also does loader constraint checking
935 //
936 // initialize_vtable and initialize_itable need to be rerun
937 // for a shared class if
938 // 1) the class is loaded by custom class loader or
939 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
940 // 3) the class was not verified during dump time
941 bool need_init_table = true;
942 if (is_shared() && verified_at_dump_time() &&
943 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
944 need_init_table = false;
945 }
946 if (need_init_table) {
947 vtable().initialize_vtable_and_check_constraints(CHECK_false);
948 itable().initialize_itable_and_check_constraints(CHECK_false);
949 }
950 #ifdef ASSERT
951 vtable().verify(tty, true);
952 // In case itable verification is ever added.
953 // itable().verify(tty, true);
954 #endif
955 set_initialization_state_and_notify(linked, THREAD);
956 if (JvmtiExport::should_post_class_prepare()) {
957 JvmtiExport::post_class_prepare(THREAD, this);
958 }
959 }
960 }
961 return true;
962 }
963
964 // Rewrite the byte codes of all of the methods of a class.
965 // The rewriter must be called exactly once. Rewriting must happen after
966 // verification but before the first method of the class is executed.
967 void InstanceKlass::rewrite_class(TRAPS) {
968 assert(is_loaded(), "must be loaded");
969 if (is_rewritten()) {
970 assert(is_shared(), "rewriting an unshared class?");
971 return;
972 }
973 Rewriter::rewrite(this, CHECK);
974 set_rewritten();
975 }
976
977 // Now relocate and link method entry points after class is rewritten.
978 // This is outside is_rewritten flag. In case of an exception, it can be
979 // executed more than once.
980 void InstanceKlass::link_methods(TRAPS) {
981 int len = methods()->length();
982 for (int i = len-1; i >= 0; i--) {
983 methodHandle m(THREAD, methods()->at(i));
984
985 // Set up method entry points for compiler and interpreter .
986 m->link_method(m, CHECK);
987 }
988 }
989
990 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
991 void InstanceKlass::initialize_super_interfaces(TRAPS) {
992 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
993 for (int i = 0; i < local_interfaces()->length(); ++i) {
994 InstanceKlass* ik = local_interfaces()->at(i);
995
996 // Initialization is depth first search ie. we start with top of the inheritance tree
997 // has_nonstatic_concrete_methods drives searching superinterfaces since it
998 // means has_nonstatic_concrete_methods in its superinterface hierarchy
999 if (ik->has_nonstatic_concrete_methods()) {
1000 ik->initialize_super_interfaces(CHECK);
1001 }
1002
1003 // Only initialize() interfaces that "declare" concrete methods.
1004 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1005 ik->initialize(CHECK);
1006 }
1007 }
1008 }
1009
1010 using InitializationErrorTable = ResourceHashtable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1011 static InitializationErrorTable* _initialization_error_table;
1012
1013 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1014 // Create the same exception with a message indicating the thread name,
1015 // and the StackTraceElements.
1016 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1017 ResourceMark rm(current);
1018 if (init_error.is_null()) {
1019 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1020
1021 // We failed to create the new exception, most likely due to either out-of-memory or
1022 // a stackoverflow error. If the original exception was either of those then we save
1023 // the shared, pre-allocated, stackless, instance of that exception.
1024 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1025 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1026 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1027 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1028 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1029 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1030 } else {
1031 return;
1032 }
1033 }
1034
1035 MutexLocker ml(current, ClassInitError_lock);
1036 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1037 bool created;
1038 if (_initialization_error_table == nullptr) {
1039 _initialization_error_table = new (mtClass) InitializationErrorTable();
1040 }
1041 _initialization_error_table->put_if_absent(this, elem, &created);
1042 assert(created, "Initialization is single threaded");
1043 log_trace(class, init)("Initialization error added for class %s", external_name());
1044 }
1045
1046 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1047 MutexLocker ml(current, ClassInitError_lock);
1048 if (_initialization_error_table == nullptr) {
1049 return nullptr;
1050 }
1051 OopHandle* h = _initialization_error_table->get(this);
1052 return (h != nullptr) ? h->resolve() : nullptr;
1053 }
1054
1055 // Need to remove entries for unloaded classes.
1056 void InstanceKlass::clean_initialization_error_table() {
1057 struct InitErrorTableCleaner {
1058 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1059 if (!ik->is_loader_alive()) {
1060 h.release(Universe::vm_global());
1061 return true;
1062 } else {
1063 return false;
1064 }
1065 }
1066 };
1067
1068 assert_locked_or_safepoint(ClassInitError_lock);
1069 InitErrorTableCleaner cleaner;
1070 if (_initialization_error_table != nullptr) {
1071 _initialization_error_table->unlink(&cleaner);
1072 }
1073 }
1074
1075 void InstanceKlass::initialize_impl(TRAPS) {
1076 HandleMark hm(THREAD);
1077
1078 // Make sure klass is linked (verified) before initialization
1079 // A class could already be verified, since it has been reflected upon.
1080 link_class(CHECK);
1081
1082 DTRACE_CLASSINIT_PROBE(required, -1);
1083
1084 bool wait = false;
1085 bool throw_error = false;
1086
1087 JavaThread* jt = THREAD;
1088
1089 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1090
1091 // refer to the JVM book page 47 for description of steps
1092 // Step 1
1093 {
1094 MonitorLocker ml(jt, _init_monitor);
1095
1096 // Step 2
1097 while (is_being_initialized() && !is_init_thread(jt)) {
1098 if (debug_logging_enabled) {
1099 ResourceMark rm(jt);
1100 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1101 jt->name(), external_name(), init_thread_name());
1102 }
1103
1104 wait = true;
1105 jt->set_class_to_be_initialized(this);
1106 ml.wait();
1107 jt->set_class_to_be_initialized(nullptr);
1108 }
1109
1110 // Step 3
1111 if (is_being_initialized() && is_init_thread(jt)) {
1112 if (debug_logging_enabled) {
1113 ResourceMark rm(jt);
1114 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1115 jt->name(), external_name());
1116 }
1117 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1118 return;
1119 }
1120
1121 // Step 4
1122 if (is_initialized()) {
1123 if (debug_logging_enabled) {
1124 ResourceMark rm(jt);
1125 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1126 jt->name(), external_name());
1127 }
1128 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1129 return;
1130 }
1131
1132 // Step 5
1133 if (is_in_error_state()) {
1134 if (debug_logging_enabled) {
1135 ResourceMark rm(jt);
1136 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1137 jt->name(), external_name());
1138 }
1139 throw_error = true;
1140 } else {
1141
1142 // Step 6
1143 set_init_state(being_initialized);
1144 set_init_thread(jt);
1145 if (debug_logging_enabled) {
1146 ResourceMark rm(jt);
1147 log_debug(class, init)("Thread \"%s\" is initializing %s",
1148 jt->name(), external_name());
1149 }
1150 }
1151 }
1152
1153 // Throw error outside lock
1154 if (throw_error) {
1155 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1156 ResourceMark rm(THREAD);
1157 Handle cause(THREAD, get_initialization_error(THREAD));
1158
1159 stringStream ss;
1160 ss.print("Could not initialize class %s", external_name());
1161 if (cause.is_null()) {
1162 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1163 } else {
1164 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1165 ss.as_string(), cause);
1166 }
1167 }
1168
1169 // Step 7
1170 // Next, if C is a class rather than an interface, initialize it's super class and super
1171 // interfaces.
1172 if (!is_interface()) {
1173 Klass* super_klass = super();
1174 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1175 super_klass->initialize(THREAD);
1176 }
1177 // If C implements any interface that declares a non-static, concrete method,
1178 // the initialization of C triggers initialization of its super interfaces.
1179 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1180 // having a superinterface that declares, non-static, concrete methods
1181 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1182 initialize_super_interfaces(THREAD);
1183 }
1184
1185 // If any exceptions, complete abruptly, throwing the same exception as above.
1186 if (HAS_PENDING_EXCEPTION) {
1187 Handle e(THREAD, PENDING_EXCEPTION);
1188 CLEAR_PENDING_EXCEPTION;
1189 {
1190 EXCEPTION_MARK;
1191 add_initialization_error(THREAD, e);
1192 // Locks object, set state, and notify all waiting threads
1193 set_initialization_state_and_notify(initialization_error, THREAD);
1194 CLEAR_PENDING_EXCEPTION;
1195 }
1196 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1197 THROW_OOP(e());
1198 }
1199 }
1200
1201
1202 // Step 8
1203 {
1204 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1205 if (class_initializer() != nullptr) {
1206 // Timer includes any side effects of class initialization (resolution,
1207 // etc), but not recursive entry into call_class_initializer().
1208 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1209 ClassLoader::perf_class_init_selftime(),
1210 ClassLoader::perf_classes_inited(),
1211 jt->get_thread_stat()->perf_recursion_counts_addr(),
1212 jt->get_thread_stat()->perf_timers_addr(),
1213 PerfClassTraceTime::CLASS_CLINIT);
1214 call_class_initializer(THREAD);
1215 } else {
1216 // The elapsed time is so small it's not worth counting.
1217 if (UsePerfData) {
1218 ClassLoader::perf_classes_inited()->inc();
1219 }
1220 call_class_initializer(THREAD);
1221 }
1222 }
1223
1224 // Step 9
1225 if (!HAS_PENDING_EXCEPTION) {
1226 set_initialization_state_and_notify(fully_initialized, THREAD);
1227 debug_only(vtable().verify(tty, true);)
1228 }
1229 else {
1230 // Step 10 and 11
1231 Handle e(THREAD, PENDING_EXCEPTION);
1232 CLEAR_PENDING_EXCEPTION;
1233 // JVMTI has already reported the pending exception
1234 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1235 JvmtiExport::clear_detected_exception(jt);
1236 {
1237 EXCEPTION_MARK;
1238 add_initialization_error(THREAD, e);
1239 set_initialization_state_and_notify(initialization_error, THREAD);
1240 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1241 // JVMTI has already reported the pending exception
1242 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1243 JvmtiExport::clear_detected_exception(jt);
1244 }
1245 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1246 if (e->is_a(vmClasses::Error_klass())) {
1247 THROW_OOP(e());
1248 } else {
1249 JavaCallArguments args(e);
1250 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1251 vmSymbols::throwable_void_signature(),
1252 &args);
1253 }
1254 }
1255 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1256 }
1257
1258
1259 void InstanceKlass::set_initialization_state_and_notify(ClassState state, JavaThread* current) {
1260 MonitorLocker ml(current, _init_monitor);
1261
1262 if (state == linked && UseVtableBasedCHA && Universe::is_fully_initialized()) {
1263 DeoptimizationScope deopt_scope;
1264 {
1265 // Now mark all code that assumes the class is not linked.
1266 // Set state under the Compile_lock also.
1267 MutexLocker ml(current, Compile_lock);
1268
1269 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1270 set_init_state(state);
1271
1272 CodeCache::mark_dependents_on(&deopt_scope, this);
1273 }
1274 // Perform the deopt handshake outside Compile_lock.
1275 deopt_scope.deoptimize_marked();
1276 } else {
1277 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1278 set_init_state(state);
1279 }
1280 ml.notify_all();
1281 }
1282
1283 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1284 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1285 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1286 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1287
1288 // In case we are not using CHA based vtables we need to make sure the loaded
1289 // deopt is completed before anyone links this class.
1290 // Linking is done with _init_monitor held, by loading and deopting with it
1291 // held we make sure the deopt is completed before linking.
1292 if (!UseVtableBasedCHA) {
1293 init_monitor()->lock();
1294 }
1295
1296 DeoptimizationScope deopt_scope;
1297 {
1298 MutexLocker ml(current, Compile_lock);
1299
1300 set_init_state(InstanceKlass::loaded);
1301 // make sure init_state store is already done.
1302 // The compiler reads the hierarchy outside of the Compile_lock.
1303 // Access ordering is used to add to hierarchy.
1304
1305 // Link into hierarchy.
1306 append_to_sibling_list(); // add to superklass/sibling list
1307 process_interfaces(); // handle all "implements" declarations
1308
1309 // Now mark all code that depended on old class hierarchy.
1310 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1311 if (Universe::is_fully_initialized()) {
1312 CodeCache::mark_dependents_on(&deopt_scope, this);
1313 }
1314 }
1315 // Perform the deopt handshake outside Compile_lock.
1316 deopt_scope.deoptimize_marked();
1317
1318 if (!UseVtableBasedCHA) {
1319 init_monitor()->unlock();
1320 }
1321 }
1322
1323 InstanceKlass* InstanceKlass::implementor() const {
1324 InstanceKlass* volatile* ik = adr_implementor();
1325 if (ik == nullptr) {
1326 return nullptr;
1327 } else {
1328 // This load races with inserts, and therefore needs acquire.
1329 InstanceKlass* ikls = Atomic::load_acquire(ik);
1330 if (ikls != nullptr && !ikls->is_loader_alive()) {
1331 return nullptr; // don't return unloaded class
1332 } else {
1333 return ikls;
1334 }
1335 }
1336 }
1337
1338
1339 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1340 assert_locked_or_safepoint(Compile_lock);
1341 assert(is_interface(), "not interface");
1342 InstanceKlass* volatile* addr = adr_implementor();
1343 assert(addr != nullptr, "null addr");
1344 if (addr != nullptr) {
1345 Atomic::release_store(addr, ik);
1346 }
1347 }
1348
1349 int InstanceKlass::nof_implementors() const {
1350 InstanceKlass* ik = implementor();
1351 if (ik == nullptr) {
1352 return 0;
1353 } else if (ik != this) {
1354 return 1;
1355 } else {
1356 return 2;
1357 }
1358 }
1359
1360 // The embedded _implementor field can only record one implementor.
1361 // When there are more than one implementors, the _implementor field
1362 // is set to the interface Klass* itself. Following are the possible
1363 // values for the _implementor field:
1364 // null - no implementor
1365 // implementor Klass* - one implementor
1366 // self - more than one implementor
1367 //
1368 // The _implementor field only exists for interfaces.
1369 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1370 if (Universe::is_fully_initialized()) {
1371 assert_lock_strong(Compile_lock);
1372 }
1373 assert(is_interface(), "not interface");
1374 // Filter out my subinterfaces.
1375 // (Note: Interfaces are never on the subklass list.)
1376 if (ik->is_interface()) return;
1377
1378 // Filter out subclasses whose supers already implement me.
1379 // (Note: CHA must walk subclasses of direct implementors
1380 // in order to locate indirect implementors.)
1381 InstanceKlass* super_ik = ik->java_super();
1382 if (super_ik != nullptr && super_ik->implements_interface(this))
1383 // We only need to check one immediate superclass, since the
1384 // implements_interface query looks at transitive_interfaces.
1385 // Any supers of the super have the same (or fewer) transitive_interfaces.
1386 return;
1387
1388 InstanceKlass* iklass = implementor();
1389 if (iklass == nullptr) {
1390 set_implementor(ik);
1391 } else if (iklass != this && iklass != ik) {
1392 // There is already an implementor. Use itself as an indicator of
1393 // more than one implementors.
1394 set_implementor(this);
1395 }
1396
1397 // The implementor also implements the transitive_interfaces
1398 for (int index = 0; index < local_interfaces()->length(); index++) {
1399 local_interfaces()->at(index)->add_implementor(ik);
1400 }
1401 }
1402
1403 void InstanceKlass::init_implementor() {
1404 if (is_interface()) {
1405 set_implementor(nullptr);
1406 }
1407 }
1408
1409
1410 void InstanceKlass::process_interfaces() {
1411 // link this class into the implementors list of every interface it implements
1412 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1413 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1414 InstanceKlass* interf = local_interfaces()->at(i);
1415 assert(interf->is_interface(), "expected interface");
1416 interf->add_implementor(this);
1417 }
1418 }
1419
1420 bool InstanceKlass::can_be_primary_super_slow() const {
1421 if (is_interface())
1422 return false;
1423 else
1424 return Klass::can_be_primary_super_slow();
1425 }
1426
1427 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1428 Array<InstanceKlass*>* transitive_interfaces) {
1429 // The secondaries are the implemented interfaces.
1430 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1431 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1432 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1433 int num_secondaries = num_extra_slots + interfaces->length();
1434 if (num_secondaries == 0) {
1435 // Must share this for correct bootstrapping!
1436 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1437 return nullptr;
1438 } else if (num_extra_slots == 0) {
1439 // The secondary super list is exactly the same as the transitive interfaces, so
1440 // let's use it instead of making a copy.
1441 // Redefine classes has to be careful not to delete this!
1442 if (!UseSecondarySupersTable) {
1443 set_secondary_supers(interfaces);
1444 return nullptr;
1445 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1446 // We will reuse the transitive interfaces list if we're certain
1447 // it's in hash order.
1448 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1449 set_secondary_supers(interfaces, bitmap);
1450 return nullptr;
1451 }
1452 // ... fall through if that didn't work.
1453 }
1454 // Copy transitive interfaces to a temporary growable array to be constructed
1455 // into the secondary super list with extra slots.
1456 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1457 for (int i = 0; i < interfaces->length(); i++) {
1458 secondaries->push(interfaces->at(i));
1459 }
1460 return secondaries;
1461 }
1462
1463 bool InstanceKlass::implements_interface(Klass* k) const {
1464 if (this == k) return true;
1465 assert(k->is_interface(), "should be an interface class");
1466 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1467 if (transitive_interfaces()->at(i) == k) {
1468 return true;
1469 }
1470 }
1471 return false;
1472 }
1473
1474 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1475 // Verify direct super interface
1476 if (this == k) return true;
1477 assert(k->is_interface(), "should be an interface class");
1478 for (int i = 0; i < local_interfaces()->length(); i++) {
1479 if (local_interfaces()->at(i) == k) {
1480 return true;
1481 }
1482 }
1483 return false;
1484 }
1485
1486 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1487 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1488 size_t size = objArrayOopDesc::object_size(length);
1489 ArrayKlass* ak = array_klass(n, CHECK_NULL);
1490 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1491 /* do_zero */ true, CHECK_NULL);
1492 return o;
1493 }
1494
1495 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1496 if (TraceFinalizerRegistration) {
1497 tty->print("Registered ");
1498 i->print_value_on(tty);
1499 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1500 }
1501 instanceHandle h_i(THREAD, i);
1502 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1503 JavaValue result(T_VOID);
1504 JavaCallArguments args(h_i);
1505 methodHandle mh(THREAD, Universe::finalizer_register_method());
1506 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1507 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1508 return h_i();
1509 }
1510
1511 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1512 assert(!is_abstract() && !is_interface(), "Should not create this object");
1513 size_t size = size_helper(); // Query before forming handle.
1514 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1515 }
1516
1517 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1518 Klass* k = java_lang_Class::as_Klass(java_class);
1519 if (k == nullptr) {
1520 ResourceMark rm(THREAD);
1521 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1522 }
1523 InstanceKlass* ik = cast(k);
1524 ik->check_valid_for_instantiation(false, CHECK_NULL);
1525 ik->initialize(CHECK_NULL);
1526 return ik->allocate_instance(THREAD);
1527 }
1528
1529 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1530 return instanceHandle(THREAD, allocate_instance(THREAD));
1531 }
1532
1533 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1534 if (is_interface() || is_abstract()) {
1535 ResourceMark rm(THREAD);
1536 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1537 : vmSymbols::java_lang_InstantiationException(), external_name());
1538 }
1539 if (this == vmClasses::Class_klass()) {
1540 ResourceMark rm(THREAD);
1541 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1542 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1543 }
1544 }
1545
1546 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1547 // Need load-acquire for lock-free read
1548 if (array_klasses_acquire() == nullptr) {
1549
1550 // Recursively lock array allocation
1551 RecursiveLocker rl(MultiArray_lock, THREAD);
1552
1553 // Check if another thread created the array klass while we were waiting for the lock.
1554 if (array_klasses() == nullptr) {
1555 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1556 // use 'release' to pair with lock-free load
1557 release_set_array_klasses(k);
1558 }
1559 }
1560
1561 // array_klasses() will always be set at this point
1562 ObjArrayKlass* ak = array_klasses();
1563 assert(ak != nullptr, "should be set");
1564 return ak->array_klass(n, THREAD);
1565 }
1566
1567 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1568 // Need load-acquire for lock-free read
1569 ObjArrayKlass* oak = array_klasses_acquire();
1570 if (oak == nullptr) {
1571 return nullptr;
1572 } else {
1573 return oak->array_klass_or_null(n);
1574 }
1575 }
1576
1577 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1578 return array_klass(1, THREAD);
1579 }
1580
1581 ArrayKlass* InstanceKlass::array_klass_or_null() {
1582 return array_klass_or_null(1);
1583 }
1584
1585 static int call_class_initializer_counter = 0; // for debugging
1586
1587 Method* InstanceKlass::class_initializer() const {
1588 Method* clinit = find_method(
1589 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1590 if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1591 return clinit;
1592 }
1593 return nullptr;
1594 }
1595
1596 void InstanceKlass::call_class_initializer(TRAPS) {
1597 if (ReplayCompiles &&
1598 (ReplaySuppressInitializers == 1 ||
1599 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1600 // Hide the existence of the initializer for the purpose of replaying the compile
1601 return;
1602 }
1603
1604 #if INCLUDE_CDS
1605 // This is needed to ensure the consistency of the archived heap objects.
1606 if (has_archived_enum_objs()) {
1607 assert(is_shared(), "must be");
1608 bool initialized = HeapShared::initialize_enum_klass(this, CHECK);
1609 if (initialized) {
1610 return;
1611 }
1612 }
1613 #endif
1614
1615 methodHandle h_method(THREAD, class_initializer());
1616 assert(!is_initialized(), "we cannot initialize twice");
1617 LogTarget(Info, class, init) lt;
1618 if (lt.is_enabled()) {
1619 ResourceMark rm(THREAD);
1620 LogStream ls(lt);
1621 ls.print("%d Initializing ", call_class_initializer_counter++);
1622 name()->print_value_on(&ls);
1623 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1624 h_method() == nullptr ? "(no method)" : "", p2i(this),
1625 THREAD->name());
1626 }
1627 if (h_method() != nullptr) {
1628 JavaCallArguments args; // No arguments
1629 JavaValue result(T_VOID);
1630 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1631 }
1632 }
1633
1634
1635 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1636 InterpreterOopMap* entry_for) {
1637 // Lazily create the _oop_map_cache at first request.
1638 // Load_acquire is needed to safely get instance published with CAS by another thread.
1639 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1640 if (oop_map_cache == nullptr) {
1641 // Try to install new instance atomically.
1642 oop_map_cache = new OopMapCache();
1643 OopMapCache* other = Atomic::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
1644 if (other != nullptr) {
1645 // Someone else managed to install before us, ditch local copy and use the existing one.
1646 delete oop_map_cache;
1647 oop_map_cache = other;
1648 }
1649 }
1650 // _oop_map_cache is constant after init; lookup below does its own locking.
1651 oop_map_cache->lookup(method, bci, entry_for);
1652 }
1653
1654 bool InstanceKlass::contains_field_offset(int offset) {
1655 fieldDescriptor fd;
1656 return find_field_from_offset(offset, false, &fd);
1657 }
1658
1659 FieldInfo InstanceKlass::field(int index) const {
1660 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1661 if (fs.index() == index) {
1662 return fs.to_FieldInfo();
1663 }
1664 }
1665 fatal("Field not found");
1666 return FieldInfo();
1667 }
1668
1669 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1670 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1671 Symbol* f_name = fs.name();
1672 Symbol* f_sig = fs.signature();
1673 if (f_name == name && f_sig == sig) {
1674 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1675 return true;
1676 }
1677 }
1678 return false;
1679 }
1680
1681
1682 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1683 const int n = local_interfaces()->length();
1684 for (int i = 0; i < n; i++) {
1685 Klass* intf1 = local_interfaces()->at(i);
1686 assert(intf1->is_interface(), "just checking type");
1687 // search for field in current interface
1688 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1689 assert(fd->is_static(), "interface field must be static");
1690 return intf1;
1691 }
1692 // search for field in direct superinterfaces
1693 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1694 if (intf2 != nullptr) return intf2;
1695 }
1696 // otherwise field lookup fails
1697 return nullptr;
1698 }
1699
1700
1701 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1702 // search order according to newest JVM spec (5.4.3.2, p.167).
1703 // 1) search for field in current klass
1704 if (find_local_field(name, sig, fd)) {
1705 return const_cast<InstanceKlass*>(this);
1706 }
1707 // 2) search for field recursively in direct superinterfaces
1708 { Klass* intf = find_interface_field(name, sig, fd);
1709 if (intf != nullptr) return intf;
1710 }
1711 // 3) apply field lookup recursively if superclass exists
1712 { Klass* supr = super();
1713 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1714 }
1715 // 4) otherwise field lookup fails
1716 return nullptr;
1717 }
1718
1719
1720 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1721 // search order according to newest JVM spec (5.4.3.2, p.167).
1722 // 1) search for field in current klass
1723 if (find_local_field(name, sig, fd)) {
1724 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1725 }
1726 // 2) search for field recursively in direct superinterfaces
1727 if (is_static) {
1728 Klass* intf = find_interface_field(name, sig, fd);
1729 if (intf != nullptr) return intf;
1730 }
1731 // 3) apply field lookup recursively if superclass exists
1732 { Klass* supr = super();
1733 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1734 }
1735 // 4) otherwise field lookup fails
1736 return nullptr;
1737 }
1738
1739
1740 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1741 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1742 if (fs.offset() == offset) {
1743 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1744 if (fd->is_static() == is_static) return true;
1745 }
1746 }
1747 return false;
1748 }
1749
1750
1751 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1752 Klass* klass = const_cast<InstanceKlass*>(this);
1753 while (klass != nullptr) {
1754 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1755 return true;
1756 }
1757 klass = klass->super();
1758 }
1759 return false;
1760 }
1761
1762
1763 void InstanceKlass::methods_do(void f(Method* method)) {
1764 // Methods aren't stable until they are loaded. This can be read outside
1765 // a lock through the ClassLoaderData for profiling
1766 // Redefined scratch classes are on the list and need to be cleaned
1767 if (!is_loaded() && !is_scratch_class()) {
1768 return;
1769 }
1770
1771 int len = methods()->length();
1772 for (int index = 0; index < len; index++) {
1773 Method* m = methods()->at(index);
1774 assert(m->is_method(), "must be method");
1775 f(m);
1776 }
1777 }
1778
1779
1780 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1781 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1782 if (fs.access_flags().is_static()) {
1783 fieldDescriptor& fd = fs.field_descriptor();
1784 cl->do_field(&fd);
1785 }
1786 }
1787 }
1788
1789
1790 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1791 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1792 if (fs.access_flags().is_static()) {
1793 fieldDescriptor& fd = fs.field_descriptor();
1794 f(&fd, mirror, CHECK);
1795 }
1796 }
1797 }
1798
1799 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1800 InstanceKlass* super = superklass();
1801 if (super != nullptr) {
1802 super->do_nonstatic_fields(cl);
1803 }
1804 fieldDescriptor fd;
1805 int length = java_fields_count();
1806 for (int i = 0; i < length; i += 1) {
1807 fd.reinitialize(this, i);
1808 if (!fd.is_static()) {
1809 cl->do_field(&fd);
1810 }
1811 }
1812 }
1813
1814 // first in Pair is offset, second is index.
1815 static int compare_fields_by_offset(Pair<int,int>* a, Pair<int,int>* b) {
1816 return a->first - b->first;
1817 }
1818
1819 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1820 InstanceKlass* super = superklass();
1821 if (super != nullptr) {
1822 super->print_nonstatic_fields(cl);
1823 }
1824 ResourceMark rm;
1825 fieldDescriptor fd;
1826 // In DebugInfo nonstatic fields are sorted by offset.
1827 GrowableArray<Pair<int,int> > fields_sorted;
1828 int i = 0;
1829 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1830 if (!fs.access_flags().is_static()) {
1831 fd = fs.field_descriptor();
1832 Pair<int,int> f(fs.offset(), fs.index());
1833 fields_sorted.push(f);
1834 i++;
1835 }
1836 }
1837 if (i > 0) {
1838 int length = i;
1839 assert(length == fields_sorted.length(), "duh");
1840 fields_sorted.sort(compare_fields_by_offset);
1841 for (int i = 0; i < length; i++) {
1842 fd.reinitialize(this, fields_sorted.at(i).second);
1843 assert(!fd.is_static() && fd.offset() == fields_sorted.at(i).first, "only nonstatic fields");
1844 cl->do_field(&fd);
1845 }
1846 }
1847 }
1848
1849 #ifdef ASSERT
1850 static int linear_search(const Array<Method*>* methods,
1851 const Symbol* name,
1852 const Symbol* signature) {
1853 const int len = methods->length();
1854 for (int index = 0; index < len; index++) {
1855 const Method* const m = methods->at(index);
1856 assert(m->is_method(), "must be method");
1857 if (m->signature() == signature && m->name() == name) {
1858 return index;
1859 }
1860 }
1861 return -1;
1862 }
1863 #endif
1864
1865 bool InstanceKlass::_disable_method_binary_search = false;
1866
1867 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1868 int len = methods->length();
1869 int l = 0;
1870 int h = len - 1;
1871 while (l <= h) {
1872 Method* m = methods->at(l);
1873 if (m->name() == name) {
1874 return l;
1875 }
1876 l++;
1877 }
1878 return -1;
1879 }
1880
1881 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1882 if (_disable_method_binary_search) {
1883 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1884 // At the final stage of dynamic dumping, the methods array may not be sorted
1885 // by ascending addresses of their names, so we can't use binary search anymore.
1886 // However, methods with the same name are still laid out consecutively inside the
1887 // methods array, so let's look for the first one that matches.
1888 return linear_search(methods, name);
1889 }
1890
1891 int len = methods->length();
1892 int l = 0;
1893 int h = len - 1;
1894
1895 // methods are sorted by ascending addresses of their names, so do binary search
1896 while (l <= h) {
1897 int mid = (l + h) >> 1;
1898 Method* m = methods->at(mid);
1899 assert(m->is_method(), "must be method");
1900 int res = m->name()->fast_compare(name);
1901 if (res == 0) {
1902 return mid;
1903 } else if (res < 0) {
1904 l = mid + 1;
1905 } else {
1906 h = mid - 1;
1907 }
1908 }
1909 return -1;
1910 }
1911
1912 // find_method looks up the name/signature in the local methods array
1913 Method* InstanceKlass::find_method(const Symbol* name,
1914 const Symbol* signature) const {
1915 return find_method_impl(name, signature,
1916 OverpassLookupMode::find,
1917 StaticLookupMode::find,
1918 PrivateLookupMode::find);
1919 }
1920
1921 Method* InstanceKlass::find_method_impl(const Symbol* name,
1922 const Symbol* signature,
1923 OverpassLookupMode overpass_mode,
1924 StaticLookupMode static_mode,
1925 PrivateLookupMode private_mode) const {
1926 return InstanceKlass::find_method_impl(methods(),
1927 name,
1928 signature,
1929 overpass_mode,
1930 static_mode,
1931 private_mode);
1932 }
1933
1934 // find_instance_method looks up the name/signature in the local methods array
1935 // and skips over static methods
1936 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1937 const Symbol* name,
1938 const Symbol* signature,
1939 PrivateLookupMode private_mode) {
1940 Method* const meth = InstanceKlass::find_method_impl(methods,
1941 name,
1942 signature,
1943 OverpassLookupMode::find,
1944 StaticLookupMode::skip,
1945 private_mode);
1946 assert(((meth == nullptr) || !meth->is_static()),
1947 "find_instance_method should have skipped statics");
1948 return meth;
1949 }
1950
1951 // find_instance_method looks up the name/signature in the local methods array
1952 // and skips over static methods
1953 Method* InstanceKlass::find_instance_method(const Symbol* name,
1954 const Symbol* signature,
1955 PrivateLookupMode private_mode) const {
1956 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1957 }
1958
1959 // Find looks up the name/signature in the local methods array
1960 // and filters on the overpass, static and private flags
1961 // This returns the first one found
1962 // note that the local methods array can have up to one overpass, one static
1963 // and one instance (private or not) with the same name/signature
1964 Method* InstanceKlass::find_local_method(const Symbol* name,
1965 const Symbol* signature,
1966 OverpassLookupMode overpass_mode,
1967 StaticLookupMode static_mode,
1968 PrivateLookupMode private_mode) const {
1969 return InstanceKlass::find_method_impl(methods(),
1970 name,
1971 signature,
1972 overpass_mode,
1973 static_mode,
1974 private_mode);
1975 }
1976
1977 // Find looks up the name/signature in the local methods array
1978 // and filters on the overpass, static and private flags
1979 // This returns the first one found
1980 // note that the local methods array can have up to one overpass, one static
1981 // and one instance (private or not) with the same name/signature
1982 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1983 const Symbol* name,
1984 const Symbol* signature,
1985 OverpassLookupMode overpass_mode,
1986 StaticLookupMode static_mode,
1987 PrivateLookupMode private_mode) {
1988 return InstanceKlass::find_method_impl(methods,
1989 name,
1990 signature,
1991 overpass_mode,
1992 static_mode,
1993 private_mode);
1994 }
1995
1996 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1997 const Symbol* name,
1998 const Symbol* signature) {
1999 return InstanceKlass::find_method_impl(methods,
2000 name,
2001 signature,
2002 OverpassLookupMode::find,
2003 StaticLookupMode::find,
2004 PrivateLookupMode::find);
2005 }
2006
2007 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2008 const Symbol* name,
2009 const Symbol* signature,
2010 OverpassLookupMode overpass_mode,
2011 StaticLookupMode static_mode,
2012 PrivateLookupMode private_mode) {
2013 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2014 return hit >= 0 ? methods->at(hit): nullptr;
2015 }
2016
2017 // true if method matches signature and conforms to skipping_X conditions.
2018 static bool method_matches(const Method* m,
2019 const Symbol* signature,
2020 bool skipping_overpass,
2021 bool skipping_static,
2022 bool skipping_private) {
2023 return ((m->signature() == signature) &&
2024 (!skipping_overpass || !m->is_overpass()) &&
2025 (!skipping_static || !m->is_static()) &&
2026 (!skipping_private || !m->is_private()));
2027 }
2028
2029 // Used directly for default_methods to find the index into the
2030 // default_vtable_indices, and indirectly by find_method
2031 // find_method_index looks in the local methods array to return the index
2032 // of the matching name/signature. If, overpass methods are being ignored,
2033 // the search continues to find a potential non-overpass match. This capability
2034 // is important during method resolution to prefer a static method, for example,
2035 // over an overpass method.
2036 // There is the possibility in any _method's array to have the same name/signature
2037 // for a static method, an overpass method and a local instance method
2038 // To correctly catch a given method, the search criteria may need
2039 // to explicitly skip the other two. For local instance methods, it
2040 // is often necessary to skip private methods
2041 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2042 const Symbol* name,
2043 const Symbol* signature,
2044 OverpassLookupMode overpass_mode,
2045 StaticLookupMode static_mode,
2046 PrivateLookupMode private_mode) {
2047 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2048 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2049 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2050 const int hit = quick_search(methods, name);
2051 if (hit != -1) {
2052 const Method* const m = methods->at(hit);
2053
2054 // Do linear search to find matching signature. First, quick check
2055 // for common case, ignoring overpasses if requested.
2056 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2057 return hit;
2058 }
2059
2060 // search downwards through overloaded methods
2061 int i;
2062 for (i = hit - 1; i >= 0; --i) {
2063 const Method* const m = methods->at(i);
2064 assert(m->is_method(), "must be method");
2065 if (m->name() != name) {
2066 break;
2067 }
2068 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2069 return i;
2070 }
2071 }
2072 // search upwards
2073 for (i = hit + 1; i < methods->length(); ++i) {
2074 const Method* const m = methods->at(i);
2075 assert(m->is_method(), "must be method");
2076 if (m->name() != name) {
2077 break;
2078 }
2079 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2080 return i;
2081 }
2082 }
2083 // not found
2084 #ifdef ASSERT
2085 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2086 linear_search(methods, name, signature);
2087 assert(-1 == index, "binary search should have found entry %d", index);
2088 #endif
2089 }
2090 return -1;
2091 }
2092
2093 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2094 return find_method_by_name(methods(), name, end);
2095 }
2096
2097 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2098 const Symbol* name,
2099 int* end_ptr) {
2100 assert(end_ptr != nullptr, "just checking");
2101 int start = quick_search(methods, name);
2102 int end = start + 1;
2103 if (start != -1) {
2104 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2105 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2106 *end_ptr = end;
2107 return start;
2108 }
2109 return -1;
2110 }
2111
2112 // uncached_lookup_method searches both the local class methods array and all
2113 // superclasses methods arrays, skipping any overpass methods in superclasses,
2114 // and possibly skipping private methods.
2115 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2116 const Symbol* signature,
2117 OverpassLookupMode overpass_mode,
2118 PrivateLookupMode private_mode) const {
2119 OverpassLookupMode overpass_local_mode = overpass_mode;
2120 const Klass* klass = this;
2121 while (klass != nullptr) {
2122 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
2123 signature,
2124 overpass_local_mode,
2125 StaticLookupMode::find,
2126 private_mode);
2127 if (method != nullptr) {
2128 return method;
2129 }
2130 klass = klass->super();
2131 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2132 }
2133 return nullptr;
2134 }
2135
2136 #ifdef ASSERT
2137 // search through class hierarchy and return true if this class or
2138 // one of the superclasses was redefined
2139 bool InstanceKlass::has_redefined_this_or_super() const {
2140 const Klass* klass = this;
2141 while (klass != nullptr) {
2142 if (InstanceKlass::cast(klass)->has_been_redefined()) {
2143 return true;
2144 }
2145 klass = klass->super();
2146 }
2147 return false;
2148 }
2149 #endif
2150
2151 // lookup a method in the default methods list then in all transitive interfaces
2152 // Do NOT return private or static methods
2153 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2154 Symbol* signature) const {
2155 Method* m = nullptr;
2156 if (default_methods() != nullptr) {
2157 m = find_method(default_methods(), name, signature);
2158 }
2159 // Look up interfaces
2160 if (m == nullptr) {
2161 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2162 }
2163 return m;
2164 }
2165
2166 // lookup a method in all the interfaces that this class implements
2167 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2168 // They should only be found in the initial InterfaceMethodRef
2169 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2170 Symbol* signature,
2171 DefaultsLookupMode defaults_mode) const {
2172 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2173 int num_ifs = all_ifs->length();
2174 InstanceKlass *ik = nullptr;
2175 for (int i = 0; i < num_ifs; i++) {
2176 ik = all_ifs->at(i);
2177 Method* m = ik->lookup_method(name, signature);
2178 if (m != nullptr && m->is_public() && !m->is_static() &&
2179 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2180 return m;
2181 }
2182 }
2183 return nullptr;
2184 }
2185
2186 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2187 :_st(st), _verbose(verbose) {
2188 ResourceMark rm;
2189 _st->print("%-18s ", "KlassAddr");
2190 _st->print("%-4s ", "Size");
2191 _st->print("%-20s ", "State");
2192 _st->print("%-7s ", "Flags");
2193 _st->print("%-5s ", "ClassName");
2194 _st->cr();
2195 }
2196
2197 void PrintClassClosure::do_klass(Klass* k) {
2198 ResourceMark rm;
2199 // klass pointer
2200 _st->print(PTR_FORMAT " ", p2i(k));
2201 // klass size
2202 _st->print("%4d ", k->size());
2203 // initialization state
2204 if (k->is_instance_klass()) {
2205 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2206 } else {
2207 _st->print("%-20s ","");
2208 }
2209 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2210 char buf[10];
2211 int i = 0;
2212 if (k->has_finalizer()) buf[i++] = 'F';
2213 if (k->is_instance_klass()) {
2214 InstanceKlass* ik = InstanceKlass::cast(k);
2215 if (ik->has_final_method()) buf[i++] = 'f';
2216 if (ik->is_rewritten()) buf[i++] = 'W';
2217 if (ik->is_contended()) buf[i++] = 'C';
2218 if (ik->has_been_redefined()) buf[i++] = 'R';
2219 if (ik->is_shared()) buf[i++] = 'S';
2220 }
2221 buf[i++] = '\0';
2222 _st->print("%-7s ", buf);
2223 // klass name
2224 _st->print("%-5s ", k->external_name());
2225 // end
2226 _st->cr();
2227 if (_verbose) {
2228 k->print_on(_st);
2229 }
2230 }
2231
2232 /* jni_id_for for jfieldIds only */
2233 JNIid* InstanceKlass::jni_id_for(int offset) {
2234 MutexLocker ml(JfieldIdCreation_lock);
2235 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2236 if (probe == nullptr) {
2237 // Allocate new static field identifier
2238 probe = new JNIid(this, offset, jni_ids());
2239 set_jni_ids(probe);
2240 }
2241 return probe;
2242 }
2243
2244 u2 InstanceKlass::enclosing_method_data(int offset) const {
2245 const Array<jushort>* const inner_class_list = inner_classes();
2246 if (inner_class_list == nullptr) {
2247 return 0;
2248 }
2249 const int length = inner_class_list->length();
2250 if (length % inner_class_next_offset == 0) {
2251 return 0;
2252 }
2253 const int index = length - enclosing_method_attribute_size;
2254 assert(offset < enclosing_method_attribute_size, "invalid offset");
2255 return inner_class_list->at(index + offset);
2256 }
2257
2258 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2259 u2 method_index) {
2260 Array<jushort>* inner_class_list = inner_classes();
2261 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2262 int length = inner_class_list->length();
2263 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2264 int index = length - enclosing_method_attribute_size;
2265 inner_class_list->at_put(
2266 index + enclosing_method_class_index_offset, class_index);
2267 inner_class_list->at_put(
2268 index + enclosing_method_method_index_offset, method_index);
2269 }
2270 }
2271
2272 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2273 if (method->is_old() && !method->is_obsolete()) {
2274 // If the method passed in is old (but not obsolete), use the current version.
2275 method = method_with_idnum((int)idnum);
2276 assert(method != nullptr, "old and but not obsolete, so should exist");
2277 }
2278 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2279 Atomic::release_store(&jmeths[idnum + 1], new_id);
2280 return new_id;
2281 }
2282
2283 // Lookup or create a jmethodID.
2284 // This code is called by the VMThread and JavaThreads so the
2285 // locking has to be done very carefully to avoid deadlocks
2286 // and/or other cache consistency problems.
2287 //
2288 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2289 Method* method = method_h();
2290 int idnum = method->method_idnum();
2291 jmethodID* jmeths = methods_jmethod_ids_acquire();
2292
2293 // We use a double-check locking idiom here because this cache is
2294 // performance sensitive. In the normal system, this cache only
2295 // transitions from null to non-null which is safe because we use
2296 // release_set_methods_jmethod_ids() to advertise the new cache.
2297 // A partially constructed cache should never be seen by a racing
2298 // thread. We also use release_store() to save a new jmethodID
2299 // in the cache so a partially constructed jmethodID should never be
2300 // seen either. Cache reads of existing jmethodIDs proceed without a
2301 // lock, but cache writes of a new jmethodID requires uniqueness and
2302 // creation of the cache itself requires no leaks so a lock is
2303 // acquired in those two cases.
2304 //
2305 // If the RedefineClasses() API has been used, then this cache grows
2306 // in the redefinition safepoint.
2307
2308 if (jmeths == nullptr) {
2309 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2310 jmeths = methods_jmethod_ids_acquire();
2311 // Still null?
2312 if (jmeths == nullptr) {
2313 size_t size = idnum_allocated_count();
2314 assert(size > (size_t)idnum, "should already have space");
2315 jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2316 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2317 // cache size is stored in element[0], other elements offset by one
2318 jmeths[0] = (jmethodID)size;
2319 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2320
2321 // publish jmeths
2322 release_set_methods_jmethod_ids(jmeths);
2323 return new_id;
2324 }
2325 }
2326
2327 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2328 if (id == nullptr) {
2329 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2330 id = jmeths[idnum + 1];
2331 // Still null?
2332 if (id == nullptr) {
2333 return update_jmethod_id(jmeths, method, idnum);
2334 }
2335 }
2336 return id;
2337 }
2338
2339 void InstanceKlass::update_methods_jmethod_cache() {
2340 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2341 jmethodID* cache = _methods_jmethod_ids;
2342 if (cache != nullptr) {
2343 size_t size = idnum_allocated_count();
2344 size_t old_size = (size_t)cache[0];
2345 if (old_size < size + 1) {
2346 // Allocate a larger one and copy entries to the new one.
2347 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2348 jmethodID* new_cache = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2349 memset(new_cache, 0, (size + 1) * sizeof(jmethodID));
2350 // The cache size is stored in element[0]; the other elements are offset by one.
2351 new_cache[0] = (jmethodID)size;
2352
2353 for (int i = 1; i <= (int)old_size; i++) {
2354 new_cache[i] = cache[i];
2355 }
2356 _methods_jmethod_ids = new_cache;
2357 FREE_C_HEAP_ARRAY(jmethodID, cache);
2358 }
2359 }
2360 }
2361
2362 // Figure out how many jmethodIDs haven't been allocated, and make
2363 // sure space for them is pre-allocated. This makes getting all
2364 // method ids much, much faster with classes with more than 8
2365 // methods, and has a *substantial* effect on performance with jvmti
2366 // code that loads all jmethodIDs for all classes.
2367 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2368 int new_jmeths = 0;
2369 int length = methods()->length();
2370 for (int index = start_offset; index < length; index++) {
2371 Method* m = methods()->at(index);
2372 jmethodID id = m->find_jmethod_id_or_null();
2373 if (id == nullptr) {
2374 new_jmeths++;
2375 }
2376 }
2377 if (new_jmeths != 0) {
2378 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2379 }
2380 }
2381
2382 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2383 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2384 int idnum = method->method_idnum();
2385 jmethodID* jmeths = methods_jmethod_ids_acquire();
2386 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2387 }
2388
2389 inline DependencyContext InstanceKlass::dependencies() {
2390 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2391 return dep_context;
2392 }
2393
2394 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2395 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2396 }
2397
2398 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2399 dependencies().add_dependent_nmethod(nm);
2400 }
2401
2402 void InstanceKlass::clean_dependency_context() {
2403 dependencies().clean_unloading_dependents();
2404 }
2405
2406 #ifndef PRODUCT
2407 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2408 dependencies().print_dependent_nmethods(verbose);
2409 }
2410
2411 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2412 return dependencies().is_dependent_nmethod(nm);
2413 }
2414 #endif //PRODUCT
2415
2416 void InstanceKlass::clean_weak_instanceklass_links() {
2417 clean_implementors_list();
2418 clean_method_data();
2419 }
2420
2421 void InstanceKlass::clean_implementors_list() {
2422 assert(is_loader_alive(), "this klass should be live");
2423 if (is_interface()) {
2424 assert (ClassUnloading, "only called for ClassUnloading");
2425 for (;;) {
2426 // Use load_acquire due to competing with inserts
2427 InstanceKlass* volatile* iklass = adr_implementor();
2428 assert(iklass != nullptr, "Klass must not be null");
2429 InstanceKlass* impl = Atomic::load_acquire(iklass);
2430 if (impl != nullptr && !impl->is_loader_alive()) {
2431 // null this field, might be an unloaded instance klass or null
2432 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2433 // Successfully unlinking implementor.
2434 if (log_is_enabled(Trace, class, unload)) {
2435 ResourceMark rm;
2436 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2437 }
2438 return;
2439 }
2440 } else {
2441 return;
2442 }
2443 }
2444 }
2445 }
2446
2447 void InstanceKlass::clean_method_data() {
2448 for (int m = 0; m < methods()->length(); m++) {
2449 MethodData* mdo = methods()->at(m)->method_data();
2450 if (mdo != nullptr) {
2451 mdo->clean_method_data(/*always_clean*/false);
2452 }
2453 }
2454 }
2455
2456 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2457 Klass::metaspace_pointers_do(it);
2458
2459 if (log_is_enabled(Trace, cds)) {
2460 ResourceMark rm;
2461 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2462 }
2463
2464 it->push(&_annotations);
2465 it->push((Klass**)&_array_klasses);
2466 if (!is_rewritten()) {
2467 it->push(&_constants, MetaspaceClosure::_writable);
2468 } else {
2469 it->push(&_constants);
2470 }
2471 it->push(&_inner_classes);
2472 #if INCLUDE_JVMTI
2473 it->push(&_previous_versions);
2474 #endif
2475 #if INCLUDE_CDS
2476 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2477 // be rewritten during runtime (see Rewriter::rewrite_jsrs()). So setting the _methods to
2478 // be writable. The length check on the _methods is necessary because classes which
2479 // don't have any methods share the Universe::_the_empty_method_array which is in the RO region.
2480 if (_methods != nullptr && _methods->length() > 0 &&
2481 !can_be_verified_at_dumptime() && methods_contain_jsr_bytecode()) {
2482 // To handle jsr bytecode, new Method* maybe stored into _methods
2483 it->push(&_methods, MetaspaceClosure::_writable);
2484 } else {
2485 #endif
2486 it->push(&_methods);
2487 #if INCLUDE_CDS
2488 }
2489 #endif
2490 it->push(&_default_methods);
2491 it->push(&_local_interfaces);
2492 it->push(&_transitive_interfaces);
2493 it->push(&_method_ordering);
2494 if (!is_rewritten()) {
2495 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2496 } else {
2497 it->push(&_default_vtable_indices);
2498 }
2499
2500 it->push(&_fieldinfo_stream);
2501 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2502 it->push(&_fields_status, MetaspaceClosure::_writable);
2503
2504 if (itable_length() > 0) {
2505 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2506 int method_table_offset_in_words = ioe->offset()/wordSize;
2507 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2508
2509 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2510 / itableOffsetEntry::size();
2511
2512 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2513 if (ioe->interface_klass() != nullptr) {
2514 it->push(ioe->interface_klass_addr());
2515 itableMethodEntry* ime = ioe->first_method_entry(this);
2516 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2517 for (int index = 0; index < n; index ++) {
2518 it->push(ime[index].method_addr());
2519 }
2520 }
2521 }
2522 }
2523
2524 it->push(&_nest_members);
2525 it->push(&_permitted_subclasses);
2526 it->push(&_record_components);
2527 }
2528
2529 #if INCLUDE_CDS
2530 void InstanceKlass::remove_unshareable_info() {
2531
2532 if (is_linked()) {
2533 assert(can_be_verified_at_dumptime(), "must be");
2534 // Remember this so we can avoid walking the hierarchy at runtime.
2535 set_verified_at_dump_time();
2536 }
2537
2538 Klass::remove_unshareable_info();
2539
2540 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2541 // Classes are attempted to link during dumping and may fail,
2542 // but these classes are still in the dictionary and class list in CLD.
2543 // If the class has failed verification, there is nothing else to remove.
2544 return;
2545 }
2546
2547 // Reset to the 'allocated' state to prevent any premature accessing to
2548 // a shared class at runtime while the class is still being loaded and
2549 // restored. A class' init_state is set to 'loaded' at runtime when it's
2550 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2551 _init_state = allocated;
2552
2553 { // Otherwise this needs to take out the Compile_lock.
2554 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2555 init_implementor();
2556 }
2557
2558 constants()->remove_unshareable_info();
2559
2560 for (int i = 0; i < methods()->length(); i++) {
2561 Method* m = methods()->at(i);
2562 m->remove_unshareable_info();
2563 }
2564
2565 // do array classes also.
2566 if (array_klasses() != nullptr) {
2567 array_klasses()->remove_unshareable_info();
2568 }
2569
2570 // These are not allocated from metaspace. They are safe to set to null.
2571 _source_debug_extension = nullptr;
2572 _dep_context = nullptr;
2573 _osr_nmethods_head = nullptr;
2574 #if INCLUDE_JVMTI
2575 _breakpoints = nullptr;
2576 _previous_versions = nullptr;
2577 _cached_class_file = nullptr;
2578 _jvmti_cached_class_field_map = nullptr;
2579 #endif
2580
2581 _init_thread = nullptr;
2582 _methods_jmethod_ids = nullptr;
2583 _jni_ids = nullptr;
2584 _oop_map_cache = nullptr;
2585 // clear _nest_host to ensure re-load at runtime
2586 _nest_host = nullptr;
2587 init_shared_package_entry();
2588 _dep_context_last_cleaned = 0;
2589 _init_monitor = nullptr;
2590
2591 remove_unshareable_flags();
2592 }
2593
2594 void InstanceKlass::remove_unshareable_flags() {
2595 // clear all the flags/stats that shouldn't be in the archived version
2596 assert(!is_scratch_class(), "must be");
2597 assert(!has_been_redefined(), "must be");
2598 #if INCLUDE_JVMTI
2599 set_is_being_redefined(false);
2600 #endif
2601 set_has_resolved_methods(false);
2602 }
2603
2604 void InstanceKlass::remove_java_mirror() {
2605 Klass::remove_java_mirror();
2606
2607 // do array classes also.
2608 if (array_klasses() != nullptr) {
2609 array_klasses()->remove_java_mirror();
2610 }
2611 }
2612
2613 void InstanceKlass::init_shared_package_entry() {
2614 assert(CDSConfig::is_dumping_archive(), "must be");
2615 #if !INCLUDE_CDS_JAVA_HEAP
2616 _package_entry = nullptr;
2617 #else
2618 if (CDSConfig::is_dumping_full_module_graph()) {
2619 if (is_shared_unregistered_class()) {
2620 _package_entry = nullptr;
2621 } else {
2622 _package_entry = PackageEntry::get_archived_entry(_package_entry);
2623 }
2624 } else if (CDSConfig::is_dumping_dynamic_archive() &&
2625 CDSConfig::is_using_full_module_graph() &&
2626 MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
2627 // _package_entry is an archived package in the base archive. Leave it as is.
2628 } else {
2629 _package_entry = nullptr;
2630 }
2631 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2632 #endif
2633 }
2634
2635 void InstanceKlass::compute_has_loops_flag_for_methods() {
2636 Array<Method*>* methods = this->methods();
2637 for (int index = 0; index < methods->length(); ++index) {
2638 Method* m = methods->at(index);
2639 if (!m->is_overpass()) { // work around JDK-8305771
2640 m->compute_has_loops_flag();
2641 }
2642 }
2643 }
2644
2645 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2646 PackageEntry* pkg_entry, TRAPS) {
2647 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2648 // before the InstanceKlass is added to the SystemDictionary. Make
2649 // sure the current state is <loaded.
2650 assert(!is_loaded(), "invalid init state");
2651 assert(!shared_loading_failed(), "Must not try to load failed class again");
2652 set_package(loader_data, pkg_entry, CHECK);
2653 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2654
2655 Array<Method*>* methods = this->methods();
2656 int num_methods = methods->length();
2657 for (int index = 0; index < num_methods; ++index) {
2658 methods->at(index)->restore_unshareable_info(CHECK);
2659 }
2660 #if INCLUDE_JVMTI
2661 if (JvmtiExport::has_redefined_a_class()) {
2662 // Reinitialize vtable because RedefineClasses may have changed some
2663 // entries in this vtable for super classes so the CDS vtable might
2664 // point to old or obsolete entries. RedefineClasses doesn't fix up
2665 // vtables in the shared system dictionary, only the main one.
2666 // It also redefines the itable too so fix that too.
2667 // First fix any default methods that point to a super class that may
2668 // have been redefined.
2669 bool trace_name_printed = false;
2670 adjust_default_methods(&trace_name_printed);
2671 vtable().initialize_vtable();
2672 itable().initialize_itable();
2673 }
2674 #endif
2675
2676 // restore constant pool resolved references
2677 constants()->restore_unshareable_info(CHECK);
2678
2679 if (array_klasses() != nullptr) {
2680 // To get a consistent list of classes we need MultiArray_lock to ensure
2681 // array classes aren't observed while they are being restored.
2682 RecursiveLocker rl(MultiArray_lock, THREAD);
2683 assert(this == array_klasses()->bottom_klass(), "sanity");
2684 // Array classes have null protection domain.
2685 // --> see ArrayKlass::complete_create_array_klass()
2686 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2687 }
2688
2689 // Initialize @ValueBased class annotation
2690 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation()) {
2691 set_is_value_based();
2692 }
2693
2694 // restore the monitor
2695 _init_monitor = create_init_monitor("InstanceKlassInitMonitorRestored_lock");
2696 }
2697
2698 // Check if a class or any of its supertypes has a version older than 50.
2699 // CDS will not perform verification of old classes during dump time because
2700 // without changing the old verifier, the verification constraint cannot be
2701 // retrieved during dump time.
2702 // Verification of archived old classes will be performed during run time.
2703 bool InstanceKlass::can_be_verified_at_dumptime() const {
2704 if (MetaspaceShared::is_in_shared_metaspace(this)) {
2705 // This is a class that was dumped into the base archive, so we know
2706 // it was verified at dump time.
2707 return true;
2708 }
2709 if (major_version() < 50 /*JAVA_6_VERSION*/) {
2710 return false;
2711 }
2712 if (java_super() != nullptr && !java_super()->can_be_verified_at_dumptime()) {
2713 return false;
2714 }
2715 Array<InstanceKlass*>* interfaces = local_interfaces();
2716 int len = interfaces->length();
2717 for (int i = 0; i < len; i++) {
2718 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2719 return false;
2720 }
2721 }
2722 return true;
2723 }
2724
2725 bool InstanceKlass::methods_contain_jsr_bytecode() const {
2726 Thread* thread = Thread::current();
2727 for (int i = 0; i < _methods->length(); i++) {
2728 methodHandle m(thread, _methods->at(i));
2729 BytecodeStream bcs(m);
2730 while (!bcs.is_last_bytecode()) {
2731 Bytecodes::Code opcode = bcs.next();
2732 if (opcode == Bytecodes::_jsr || opcode == Bytecodes::_jsr_w) {
2733 return true;
2734 }
2735 }
2736 }
2737 return false;
2738 }
2739 #endif // INCLUDE_CDS
2740
2741 #if INCLUDE_JVMTI
2742 static void clear_all_breakpoints(Method* m) {
2743 m->clear_all_breakpoints();
2744 }
2745 #endif
2746
2747 void InstanceKlass::unload_class(InstanceKlass* ik) {
2748 // Release dependencies.
2749 ik->dependencies().remove_all_dependents();
2750
2751 // notify the debugger
2752 if (JvmtiExport::should_post_class_unload()) {
2753 JvmtiExport::post_class_unload(ik);
2754 }
2755
2756 // notify ClassLoadingService of class unload
2757 ClassLoadingService::notify_class_unloaded(ik);
2758
2759 SystemDictionaryShared::handle_class_unloading(ik);
2760
2761 if (log_is_enabled(Info, class, unload)) {
2762 ResourceMark rm;
2763 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2764 }
2765
2766 Events::log_class_unloading(Thread::current(), ik);
2767
2768 #if INCLUDE_JFR
2769 assert(ik != nullptr, "invariant");
2770 EventClassUnload event;
2771 event.set_unloadedClass(ik);
2772 event.set_definingClassLoader(ik->class_loader_data());
2773 event.commit();
2774 #endif
2775 }
2776
2777 static void method_release_C_heap_structures(Method* m) {
2778 m->release_C_heap_structures();
2779 }
2780
2781 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2782 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2783 // Clean up C heap
2784 Klass::release_C_heap_structures();
2785
2786 // Deallocate and call destructors for MDO mutexes
2787 if (release_sub_metadata) {
2788 methods_do(method_release_C_heap_structures);
2789 }
2790
2791 // Destroy the init_monitor
2792 delete _init_monitor;
2793
2794 // Deallocate oop map cache
2795 if (_oop_map_cache != nullptr) {
2796 delete _oop_map_cache;
2797 _oop_map_cache = nullptr;
2798 }
2799
2800 // Deallocate JNI identifiers for jfieldIDs
2801 JNIid::deallocate(jni_ids());
2802 set_jni_ids(nullptr);
2803
2804 jmethodID* jmeths = methods_jmethod_ids_acquire();
2805 if (jmeths != nullptr) {
2806 release_set_methods_jmethod_ids(nullptr);
2807 FreeHeap(jmeths);
2808 }
2809
2810 assert(_dep_context == nullptr,
2811 "dependencies should already be cleaned");
2812
2813 #if INCLUDE_JVMTI
2814 // Deallocate breakpoint records
2815 if (breakpoints() != 0x0) {
2816 methods_do(clear_all_breakpoints);
2817 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2818 }
2819
2820 // deallocate the cached class file
2821 if (_cached_class_file != nullptr) {
2822 os::free(_cached_class_file);
2823 _cached_class_file = nullptr;
2824 }
2825 #endif
2826
2827 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2828
2829 if (release_sub_metadata) {
2830 constants()->release_C_heap_structures();
2831 }
2832 }
2833
2834 // The constant pool is on stack if any of the methods are executing or
2835 // referenced by handles.
2836 bool InstanceKlass::on_stack() const {
2837 return _constants->on_stack();
2838 }
2839
2840 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
2841 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
2842 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
2843
2844 // minor and major version numbers of class file
2845 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
2846 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
2847 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
2848 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
2849
2850 InstanceKlass* InstanceKlass::get_klass_version(int version) {
2851 for (InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
2852 if (ik->constants()->version() == version) {
2853 return ik;
2854 }
2855 }
2856 return nullptr;
2857 }
2858
2859 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2860 if (array == nullptr) {
2861 _source_debug_extension = nullptr;
2862 } else {
2863 // Adding one to the attribute length in order to store a null terminator
2864 // character could cause an overflow because the attribute length is
2865 // already coded with an u4 in the classfile, but in practice, it's
2866 // unlikely to happen.
2867 assert((length+1) > length, "Overflow checking");
2868 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2869 for (int i = 0; i < length; i++) {
2870 sde[i] = array[i];
2871 }
2872 sde[length] = '\0';
2873 _source_debug_extension = sde;
2874 }
2875 }
2876
2877 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
2878 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
2879 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
2880
2881 const char* InstanceKlass::signature_name() const {
2882
2883 // Get the internal name as a c string
2884 const char* src = (const char*) (name()->as_C_string());
2885 const int src_length = (int)strlen(src);
2886
2887 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
2888
2889 // Add L as type indicator
2890 int dest_index = 0;
2891 dest[dest_index++] = JVM_SIGNATURE_CLASS;
2892
2893 // Add the actual class name
2894 for (int src_index = 0; src_index < src_length; ) {
2895 dest[dest_index++] = src[src_index++];
2896 }
2897
2898 if (is_hidden()) { // Replace the last '+' with a '.'.
2899 for (int index = (int)src_length; index > 0; index--) {
2900 if (dest[index] == '+') {
2901 dest[index] = JVM_SIGNATURE_DOT;
2902 break;
2903 }
2904 }
2905 }
2906
2907 // Add the semicolon and the null
2908 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
2909 dest[dest_index] = '\0';
2910 return dest;
2911 }
2912
2913 ModuleEntry* InstanceKlass::module() const {
2914 if (is_hidden() &&
2915 in_unnamed_package() &&
2916 class_loader_data()->has_class_mirror_holder()) {
2917 // For a non-strong hidden class defined to an unnamed package,
2918 // its (class held) CLD will not have an unnamed module created for it.
2919 // Two choices to find the correct ModuleEntry:
2920 // 1. If hidden class is within a nest, use nest host's module
2921 // 2. Find the unnamed module off from the class loader
2922 // For now option #2 is used since a nest host is not set until
2923 // after the instance class is created in jvm_lookup_define_class().
2924 if (class_loader_data()->is_boot_class_loader_data()) {
2925 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
2926 } else {
2927 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
2928 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
2929 return java_lang_Module::module_entry(module);
2930 }
2931 }
2932
2933 // Class is in a named package
2934 if (!in_unnamed_package()) {
2935 return _package_entry->module();
2936 }
2937
2938 // Class is in an unnamed package, return its loader's unnamed module
2939 return class_loader_data()->unnamed_module();
2940 }
2941
2942 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
2943
2944 // ensure java/ packages only loaded by boot or platform builtin loaders
2945 // not needed for shared class since CDS does not archive prohibited classes.
2946 if (!is_shared()) {
2947 check_prohibited_package(name(), loader_data, CHECK);
2948 }
2949
2950 if (is_shared() && _package_entry != nullptr) {
2951 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
2952 // we can use the saved package
2953 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
2954 return;
2955 } else {
2956 _package_entry = nullptr;
2957 }
2958 }
2959
2960 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
2961 // it returns, so we need to decrement it when the current function exits.
2962 TempNewSymbol from_class_name =
2963 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
2964
2965 Symbol* pkg_name;
2966 if (pkg_entry != nullptr) {
2967 pkg_name = pkg_entry->name();
2968 } else {
2969 pkg_name = from_class_name;
2970 }
2971
2972 if (pkg_name != nullptr && loader_data != nullptr) {
2973
2974 // Find in class loader's package entry table.
2975 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
2976
2977 // If the package name is not found in the loader's package
2978 // entry table, it is an indication that the package has not
2979 // been defined. Consider it defined within the unnamed module.
2980 if (_package_entry == nullptr) {
2981
2982 if (!ModuleEntryTable::javabase_defined()) {
2983 // Before java.base is defined during bootstrapping, define all packages in
2984 // the java.base module. If a non-java.base package is erroneously placed
2985 // in the java.base module it will be caught later when java.base
2986 // is defined by ModuleEntryTable::verify_javabase_packages check.
2987 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
2988 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2989 } else {
2990 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
2991 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
2992 }
2993
2994 // A package should have been successfully created
2995 DEBUG_ONLY(ResourceMark rm(THREAD));
2996 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
2997 name()->as_C_string(), loader_data->loader_name_and_id());
2998 }
2999
3000 if (log_is_enabled(Debug, module)) {
3001 ResourceMark rm(THREAD);
3002 ModuleEntry* m = _package_entry->module();
3003 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3004 external_name(),
3005 pkg_name->as_C_string(),
3006 loader_data->loader_name_and_id(),
3007 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3008 }
3009 } else {
3010 ResourceMark rm(THREAD);
3011 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3012 external_name(),
3013 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3014 UNNAMED_MODULE);
3015 }
3016 }
3017
3018 // Function set_classpath_index ensures that for a non-null _package_entry
3019 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3020 // It then sets the classpath_index in the package entry record.
3021 //
3022 // The classpath_index field is used to find the entry on the boot loader class
3023 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3024 // in an unnamed module. It is also used to indicate (for all packages whose
3025 // classes are loaded by the boot loader) that at least one of the package's
3026 // classes has been loaded.
3027 void InstanceKlass::set_classpath_index(s2 path_index) {
3028 if (_package_entry != nullptr) {
3029 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3030 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3031 assert(path_index != -1, "Unexpected classpath_index");
3032 _package_entry->set_classpath_index(path_index);
3033 }
3034 }
3035
3036 // different versions of is_same_class_package
3037
3038 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3039 oop classloader1 = this->class_loader();
3040 PackageEntry* classpkg1 = this->package();
3041 if (class2->is_objArray_klass()) {
3042 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3043 }
3044
3045 oop classloader2;
3046 PackageEntry* classpkg2;
3047 if (class2->is_instance_klass()) {
3048 classloader2 = class2->class_loader();
3049 classpkg2 = class2->package();
3050 } else {
3051 assert(class2->is_typeArray_klass(), "should be type array");
3052 classloader2 = nullptr;
3053 classpkg2 = nullptr;
3054 }
3055
3056 // Same package is determined by comparing class loader
3057 // and package entries. Both must be the same. This rule
3058 // applies even to classes that are defined in the unnamed
3059 // package, they still must have the same class loader.
3060 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3061 return true;
3062 }
3063
3064 return false;
3065 }
3066
3067 // return true if this class and other_class are in the same package. Classloader
3068 // and classname information is enough to determine a class's package
3069 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3070 const Symbol* other_class_name) const {
3071 if (class_loader() != other_class_loader) {
3072 return false;
3073 }
3074 if (name()->fast_compare(other_class_name) == 0) {
3075 return true;
3076 }
3077
3078 {
3079 ResourceMark rm;
3080
3081 bool bad_class_name = false;
3082 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3083 if (bad_class_name) {
3084 return false;
3085 }
3086 // Check that package_from_class_name() returns null, not "", if there is no package.
3087 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3088
3089 const Symbol* const this_package_name =
3090 this->package() != nullptr ? this->package()->name() : nullptr;
3091
3092 if (this_package_name == nullptr || other_pkg == nullptr) {
3093 // One of the two doesn't have a package. Only return true if the other
3094 // one also doesn't have a package.
3095 return this_package_name == other_pkg;
3096 }
3097
3098 // Check if package is identical
3099 return this_package_name->fast_compare(other_pkg) == 0;
3100 }
3101 }
3102
3103 static bool is_prohibited_package_slow(Symbol* class_name) {
3104 // Caller has ResourceMark
3105 int length;
3106 jchar* unicode = class_name->as_unicode(length);
3107 return (length >= 5 &&
3108 unicode[0] == 'j' &&
3109 unicode[1] == 'a' &&
3110 unicode[2] == 'v' &&
3111 unicode[3] == 'a' &&
3112 unicode[4] == '/');
3113 }
3114
3115 // Only boot and platform class loaders can define classes in "java/" packages.
3116 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3117 ClassLoaderData* loader_data,
3118 TRAPS) {
3119 if (!loader_data->is_boot_class_loader_data() &&
3120 !loader_data->is_platform_class_loader_data() &&
3121 class_name != nullptr && class_name->utf8_length() >= 5) {
3122 ResourceMark rm(THREAD);
3123 bool prohibited;
3124 const u1* base = class_name->base();
3125 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3126 prohibited = is_prohibited_package_slow(class_name);
3127 } else {
3128 char* name = class_name->as_C_string();
3129 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3130 }
3131 if (prohibited) {
3132 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3133 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3134 char* name = pkg_name->as_C_string();
3135 const char* class_loader_name = loader_data->loader_name_and_id();
3136 StringUtils::replace_no_expand(name, "/", ".");
3137 const char* msg_text1 = "Class loader (instance of): ";
3138 const char* msg_text2 = " tried to load prohibited package name: ";
3139 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3140 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3141 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3142 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3143 }
3144 }
3145 return;
3146 }
3147
3148 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3149 constantPoolHandle i_cp(THREAD, constants());
3150 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3151 int ioff = iter.inner_class_info_index();
3152 if (ioff != 0) {
3153 // Check to see if the name matches the class we're looking for
3154 // before attempting to find the class.
3155 if (i_cp->klass_name_at_matches(this, ioff)) {
3156 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3157 if (this == inner_klass) {
3158 *ooff = iter.outer_class_info_index();
3159 *noff = iter.inner_name_index();
3160 return true;
3161 }
3162 }
3163 }
3164 }
3165 return false;
3166 }
3167
3168 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3169 InstanceKlass* outer_klass = nullptr;
3170 *inner_is_member = false;
3171 int ooff = 0, noff = 0;
3172 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3173 if (has_inner_classes_attr) {
3174 constantPoolHandle i_cp(THREAD, constants());
3175 if (ooff != 0) {
3176 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3177 if (!ok->is_instance_klass()) {
3178 // If the outer class is not an instance klass then it cannot have
3179 // declared any inner classes.
3180 ResourceMark rm(THREAD);
3181 Exceptions::fthrow(
3182 THREAD_AND_LOCATION,
3183 vmSymbols::java_lang_IncompatibleClassChangeError(),
3184 "%s and %s disagree on InnerClasses attribute",
3185 ok->external_name(),
3186 external_name());
3187 return nullptr;
3188 }
3189 outer_klass = InstanceKlass::cast(ok);
3190 *inner_is_member = true;
3191 }
3192 if (nullptr == outer_klass) {
3193 // It may be a local class; try for that.
3194 int encl_method_class_idx = enclosing_method_class_index();
3195 if (encl_method_class_idx != 0) {
3196 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3197 outer_klass = InstanceKlass::cast(ok);
3198 *inner_is_member = false;
3199 }
3200 }
3201 }
3202
3203 // If no inner class attribute found for this class.
3204 if (nullptr == outer_klass) return nullptr;
3205
3206 // Throws an exception if outer klass has not declared k as an inner klass
3207 // We need evidence that each klass knows about the other, or else
3208 // the system could allow a spoof of an inner class to gain access rights.
3209 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3210 return outer_klass;
3211 }
3212
3213 jint InstanceKlass::compute_modifier_flags() const {
3214 jint access = access_flags().as_int();
3215
3216 // But check if it happens to be member class.
3217 InnerClassesIterator iter(this);
3218 for (; !iter.done(); iter.next()) {
3219 int ioff = iter.inner_class_info_index();
3220 // Inner class attribute can be zero, skip it.
3221 // Strange but true: JVM spec. allows null inner class refs.
3222 if (ioff == 0) continue;
3223
3224 // only look at classes that are already loaded
3225 // since we are looking for the flags for our self.
3226 Symbol* inner_name = constants()->klass_name_at(ioff);
3227 if (name() == inner_name) {
3228 // This is really a member class.
3229 access = iter.inner_access_flags();
3230 break;
3231 }
3232 }
3233 // Remember to strip ACC_SUPER bit
3234 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
3235 }
3236
3237 jint InstanceKlass::jvmti_class_status() const {
3238 jint result = 0;
3239
3240 if (is_linked()) {
3241 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3242 }
3243
3244 if (is_initialized()) {
3245 assert(is_linked(), "Class status is not consistent");
3246 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3247 }
3248 if (is_in_error_state()) {
3249 result |= JVMTI_CLASS_STATUS_ERROR;
3250 }
3251 return result;
3252 }
3253
3254 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3255 bool implements_interface; // initialized by method_at_itable_or_null
3256 Method* m = method_at_itable_or_null(holder, index,
3257 implements_interface); // out parameter
3258 if (m != nullptr) {
3259 assert(implements_interface, "sanity");
3260 return m;
3261 } else if (implements_interface) {
3262 // Throw AbstractMethodError since corresponding itable slot is empty.
3263 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3264 } else {
3265 // If the interface isn't implemented by the receiver class,
3266 // the VM should throw IncompatibleClassChangeError.
3267 ResourceMark rm(THREAD);
3268 stringStream ss;
3269 bool same_module = (module() == holder->module());
3270 ss.print("Receiver class %s does not implement "
3271 "the interface %s defining the method to be called "
3272 "(%s%s%s)",
3273 external_name(), holder->external_name(),
3274 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3275 (same_module) ? "" : "; ",
3276 (same_module) ? "" : holder->class_in_module_of_loader());
3277 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3278 }
3279 }
3280
3281 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3282 klassItable itable(this);
3283 for (int i = 0; i < itable.size_offset_table(); i++) {
3284 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3285 if (offset_entry->interface_klass() == holder) {
3286 implements_interface = true;
3287 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3288 Method* m = ime[index].method();
3289 return m;
3290 }
3291 }
3292 implements_interface = false;
3293 return nullptr; // offset entry not found
3294 }
3295
3296 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3297 assert(is_linked(), "required");
3298 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3299 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3300
3301 int vtable_index = Method::invalid_vtable_index;
3302 Symbol* name = intf_method->name();
3303 Symbol* signature = intf_method->signature();
3304
3305 // First check in default method array
3306 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3307 int index = find_method_index(default_methods(),
3308 name, signature,
3309 Klass::OverpassLookupMode::find,
3310 Klass::StaticLookupMode::find,
3311 Klass::PrivateLookupMode::find);
3312 if (index >= 0) {
3313 vtable_index = default_vtable_indices()->at(index);
3314 }
3315 }
3316 if (vtable_index == Method::invalid_vtable_index) {
3317 // get vtable_index for miranda methods
3318 klassVtable vt = vtable();
3319 vtable_index = vt.index_of_miranda(name, signature);
3320 }
3321 return vtable_index;
3322 }
3323
3324 #if INCLUDE_JVMTI
3325 // update default_methods for redefineclasses for methods that are
3326 // not yet in the vtable due to concurrent subclass define and superinterface
3327 // redefinition
3328 // Note: those in the vtable, should have been updated via adjust_method_entries
3329 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3330 // search the default_methods for uses of either obsolete or EMCP methods
3331 if (default_methods() != nullptr) {
3332 for (int index = 0; index < default_methods()->length(); index ++) {
3333 Method* old_method = default_methods()->at(index);
3334 if (old_method == nullptr || !old_method->is_old()) {
3335 continue; // skip uninteresting entries
3336 }
3337 assert(!old_method->is_deleted(), "default methods may not be deleted");
3338 Method* new_method = old_method->get_new_method();
3339 default_methods()->at_put(index, new_method);
3340
3341 if (log_is_enabled(Info, redefine, class, update)) {
3342 ResourceMark rm;
3343 if (!(*trace_name_printed)) {
3344 log_info(redefine, class, update)
3345 ("adjust: klassname=%s default methods from name=%s",
3346 external_name(), old_method->method_holder()->external_name());
3347 *trace_name_printed = true;
3348 }
3349 log_debug(redefine, class, update, vtables)
3350 ("default method update: %s(%s) ",
3351 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3352 }
3353 }
3354 }
3355 }
3356 #endif // INCLUDE_JVMTI
3357
3358 // On-stack replacement stuff
3359 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3360 assert_lock_strong(NMethodState_lock);
3361 #ifndef PRODUCT
3362 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3363 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3364 "redundant OSR recompilation detected. memory leak in CodeCache!");
3365 #endif
3366 // only one compilation can be active
3367 assert(n->is_osr_method(), "wrong kind of nmethod");
3368 n->set_osr_link(osr_nmethods_head());
3369 set_osr_nmethods_head(n);
3370 // Raise the highest osr level if necessary
3371 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3372
3373 // Get rid of the osr methods for the same bci that have lower levels.
3374 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3375 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3376 if (inv != nullptr && inv->is_in_use()) {
3377 inv->make_not_entrant();
3378 }
3379 }
3380 }
3381
3382 // Remove osr nmethod from the list. Return true if found and removed.
3383 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3384 // This is a short non-blocking critical region, so the no safepoint check is ok.
3385 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3386 assert(n->is_osr_method(), "wrong kind of nmethod");
3387 nmethod* last = nullptr;
3388 nmethod* cur = osr_nmethods_head();
3389 int max_level = CompLevel_none; // Find the max comp level excluding n
3390 Method* m = n->method();
3391 // Search for match
3392 bool found = false;
3393 while(cur != nullptr && cur != n) {
3394 if (m == cur->method()) {
3395 // Find max level before n
3396 max_level = MAX2(max_level, cur->comp_level());
3397 }
3398 last = cur;
3399 cur = cur->osr_link();
3400 }
3401 nmethod* next = nullptr;
3402 if (cur == n) {
3403 found = true;
3404 next = cur->osr_link();
3405 if (last == nullptr) {
3406 // Remove first element
3407 set_osr_nmethods_head(next);
3408 } else {
3409 last->set_osr_link(next);
3410 }
3411 }
3412 n->set_osr_link(nullptr);
3413 cur = next;
3414 while (cur != nullptr) {
3415 // Find max level after n
3416 if (m == cur->method()) {
3417 max_level = MAX2(max_level, cur->comp_level());
3418 }
3419 cur = cur->osr_link();
3420 }
3421 m->set_highest_osr_comp_level(max_level);
3422 return found;
3423 }
3424
3425 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3426 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3427 nmethod* osr = osr_nmethods_head();
3428 int found = 0;
3429 while (osr != nullptr) {
3430 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3431 if (osr->method() == m) {
3432 deopt_scope->mark(osr);
3433 found++;
3434 }
3435 osr = osr->osr_link();
3436 }
3437 return found;
3438 }
3439
3440 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3441 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3442 nmethod* osr = osr_nmethods_head();
3443 nmethod* best = nullptr;
3444 while (osr != nullptr) {
3445 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3446 // There can be a time when a c1 osr method exists but we are waiting
3447 // for a c2 version. When c2 completes its osr nmethod we will trash
3448 // the c1 version and only be able to find the c2 version. However
3449 // while we overflow in the c1 code at back branches we don't want to
3450 // try and switch to the same code as we are already running
3451
3452 if (osr->method() == m &&
3453 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3454 if (match_level) {
3455 if (osr->comp_level() == comp_level) {
3456 // Found a match - return it.
3457 return osr;
3458 }
3459 } else {
3460 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3461 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3462 // Found the best possible - return it.
3463 return osr;
3464 }
3465 best = osr;
3466 }
3467 }
3468 }
3469 osr = osr->osr_link();
3470 }
3471
3472 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3473 if (best != nullptr && best->comp_level() >= comp_level) {
3474 return best;
3475 }
3476 return nullptr;
3477 }
3478
3479 // -----------------------------------------------------------------------------------------------------
3480 // Printing
3481
3482 #define BULLET " - "
3483
3484 static const char* state_names[] = {
3485 "allocated", "loaded", "being_linked", "linked", "being_initialized", "fully_initialized", "initialization_error"
3486 };
3487
3488 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3489 for (int i = 0; i < len; i++) {
3490 intptr_t e = start[i];
3491 st->print("%d : " INTPTR_FORMAT, i, e);
3492 if (MetaspaceObj::is_valid((Metadata*)e)) {
3493 st->print(" ");
3494 ((Metadata*)e)->print_value_on(st);
3495 }
3496 st->cr();
3497 }
3498 }
3499
3500 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3501 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3502 }
3503
3504 const char* InstanceKlass::init_state_name() const {
3505 return state_names[init_state()];
3506 }
3507
3508 void InstanceKlass::print_on(outputStream* st) const {
3509 assert(is_klass(), "must be klass");
3510 Klass::print_on(st);
3511
3512 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3513 st->print(BULLET"klass size: %d", size()); st->cr();
3514 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3515 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
3516 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
3517 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3518 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3519 st->print(BULLET"sub: ");
3520 Klass* sub = subklass();
3521 int n;
3522 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3523 if (n < MaxSubklassPrintSize) {
3524 sub->print_value_on(st);
3525 st->print(" ");
3526 }
3527 }
3528 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3529 st->cr();
3530
3531 if (is_interface()) {
3532 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3533 if (nof_implementors() == 1) {
3534 st->print_cr(BULLET"implementor: ");
3535 st->print(" ");
3536 implementor()->print_value_on(st);
3537 st->cr();
3538 }
3539 }
3540
3541 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3542 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3543 if (Verbose || WizardMode) {
3544 Array<Method*>* method_array = methods();
3545 for (int i = 0; i < method_array->length(); i++) {
3546 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3547 }
3548 }
3549 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3550 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3551 if (Verbose && default_methods() != nullptr) {
3552 Array<Method*>* method_array = default_methods();
3553 for (int i = 0; i < method_array->length(); i++) {
3554 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3555 }
3556 }
3557 if (default_vtable_indices() != nullptr) {
3558 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
3559 }
3560 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3561 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3562
3563 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
3564 if (UseSecondarySupersTable) {
3565 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
3566 st->print(BULLET"bitmap: " UINTX_FORMAT_X_0, _bitmap); st->cr();
3567 }
3568 if (secondary_supers() != nullptr) {
3569 if (Verbose) {
3570 bool is_hashed = UseSecondarySupersTable && (_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
3571 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
3572 for (int i = 0; i < _secondary_supers->length(); i++) {
3573 ResourceMark rm; // for external_name()
3574 Klass* secondary_super = _secondary_supers->at(i);
3575 st->print(BULLET"%2d:", i);
3576 if (is_hashed) {
3577 int home_slot = compute_home_slot(secondary_super, _bitmap);
3578 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
3579 st->print(" dist:%02d:", distance);
3580 }
3581 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
3582 }
3583 }
3584 }
3585 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3586 if (class_loader_data() != nullptr) {
3587 st->print(BULLET"class loader data: ");
3588 class_loader_data()->print_value_on(st);
3589 st->cr();
3590 }
3591 if (source_file_name() != nullptr) {
3592 st->print(BULLET"source file: ");
3593 source_file_name()->print_value_on(st);
3594 st->cr();
3595 }
3596 if (source_debug_extension() != nullptr) {
3597 st->print(BULLET"source debug extension: ");
3598 st->print("%s", source_debug_extension());
3599 st->cr();
3600 }
3601 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
3602 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
3603 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
3604 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
3605 {
3606 bool have_pv = false;
3607 // previous versions are linked together through the InstanceKlass
3608 for (InstanceKlass* pv_node = previous_versions();
3609 pv_node != nullptr;
3610 pv_node = pv_node->previous_versions()) {
3611 if (!have_pv)
3612 st->print(BULLET"previous version: ");
3613 have_pv = true;
3614 pv_node->constants()->print_value_on(st);
3615 }
3616 if (have_pv) st->cr();
3617 }
3618
3619 if (generic_signature() != nullptr) {
3620 st->print(BULLET"generic signature: ");
3621 generic_signature()->print_value_on(st);
3622 st->cr();
3623 }
3624 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3625 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3626 if (record_components() != nullptr) {
3627 st->print(BULLET"record components: "); record_components()->print_value_on(st); st->cr();
3628 }
3629 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
3630 if (java_mirror() != nullptr) {
3631 st->print(BULLET"java mirror: ");
3632 java_mirror()->print_value_on(st);
3633 st->cr();
3634 } else {
3635 st->print_cr(BULLET"java mirror: null");
3636 }
3637 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3638 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3639 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3640 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3641 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3642
3643 FieldPrinter print_static_field(st);
3644 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3645 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3646 FieldPrinter print_nonstatic_field(st);
3647 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3648 ik->print_nonstatic_fields(&print_nonstatic_field);
3649
3650 st->print(BULLET"non-static oop maps: ");
3651 OopMapBlock* map = start_of_nonstatic_oop_maps();
3652 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3653 while (map < end_map) {
3654 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3655 map++;
3656 }
3657 st->cr();
3658 }
3659
3660 void InstanceKlass::print_value_on(outputStream* st) const {
3661 assert(is_klass(), "must be klass");
3662 if (Verbose || WizardMode) access_flags().print_on(st);
3663 name()->print_value_on(st);
3664 }
3665
3666 void FieldPrinter::do_field(fieldDescriptor* fd) {
3667 _st->print(BULLET);
3668 if (_obj == nullptr) {
3669 fd->print_on(_st);
3670 _st->cr();
3671 } else {
3672 fd->print_on_for(_st, _obj);
3673 _st->cr();
3674 }
3675 }
3676
3677
3678 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3679 Klass::oop_print_on(obj, st);
3680
3681 if (this == vmClasses::String_klass()) {
3682 typeArrayOop value = java_lang_String::value(obj);
3683 juint length = java_lang_String::length(obj);
3684 if (value != nullptr &&
3685 value->is_typeArray() &&
3686 length <= (juint) value->length()) {
3687 st->print(BULLET"string: ");
3688 java_lang_String::print(obj, st);
3689 st->cr();
3690 }
3691 }
3692
3693 st->print_cr(BULLET"---- fields (total size " SIZE_FORMAT " words):", oop_size(obj));
3694 FieldPrinter print_field(st, obj);
3695 print_nonstatic_fields(&print_field);
3696
3697 if (this == vmClasses::Class_klass()) {
3698 st->print(BULLET"signature: ");
3699 java_lang_Class::print_signature(obj, st);
3700 st->cr();
3701 Klass* real_klass = java_lang_Class::as_Klass(obj);
3702 if (real_klass != nullptr && real_klass->is_instance_klass()) {
3703 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3704 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3705 }
3706 } else if (this == vmClasses::MethodType_klass()) {
3707 st->print(BULLET"signature: ");
3708 java_lang_invoke_MethodType::print_signature(obj, st);
3709 st->cr();
3710 }
3711 }
3712
3713 #ifndef PRODUCT
3714
3715 bool InstanceKlass::verify_itable_index(int i) {
3716 int method_count = klassItable::method_count_for_interface(this);
3717 assert(i >= 0 && i < method_count, "index out of bounds");
3718 return true;
3719 }
3720
3721 #endif //PRODUCT
3722
3723 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3724 st->print("a ");
3725 name()->print_value_on(st);
3726 obj->print_address_on(st);
3727 if (this == vmClasses::String_klass()
3728 && java_lang_String::value(obj) != nullptr) {
3729 ResourceMark rm;
3730 int len = java_lang_String::length(obj);
3731 int plen = (len < 24 ? len : 12);
3732 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3733 st->print(" = \"%s\"", str);
3734 if (len > plen)
3735 st->print("...[%d]", len);
3736 } else if (this == vmClasses::Class_klass()) {
3737 Klass* k = java_lang_Class::as_Klass(obj);
3738 st->print(" = ");
3739 if (k != nullptr) {
3740 k->print_value_on(st);
3741 } else {
3742 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3743 st->print("%s", tname ? tname : "type?");
3744 }
3745 } else if (this == vmClasses::MethodType_klass()) {
3746 st->print(" = ");
3747 java_lang_invoke_MethodType::print_signature(obj, st);
3748 } else if (java_lang_boxing_object::is_instance(obj)) {
3749 st->print(" = ");
3750 java_lang_boxing_object::print(obj, st);
3751 } else if (this == vmClasses::LambdaForm_klass()) {
3752 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3753 if (vmentry != nullptr) {
3754 st->print(" => ");
3755 vmentry->print_value_on(st);
3756 }
3757 } else if (this == vmClasses::MemberName_klass()) {
3758 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3759 if (vmtarget != nullptr) {
3760 st->print(" = ");
3761 vmtarget->print_value_on(st);
3762 } else {
3763 oop clazz = java_lang_invoke_MemberName::clazz(obj);
3764 oop name = java_lang_invoke_MemberName::name(obj);
3765 if (clazz != nullptr) {
3766 clazz->print_value_on(st);
3767 } else {
3768 st->print("null");
3769 }
3770 st->print(".");
3771 if (name != nullptr) {
3772 name->print_value_on(st);
3773 } else {
3774 st->print("null");
3775 }
3776 }
3777 }
3778 }
3779
3780 const char* InstanceKlass::internal_name() const {
3781 return external_name();
3782 }
3783
3784 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3785 const ModuleEntry* module_entry,
3786 const ClassFileStream* cfs) const {
3787
3788 if (ClassListWriter::is_enabled()) {
3789 ClassListWriter::write(this, cfs);
3790 }
3791
3792 print_class_load_helper(loader_data, module_entry, cfs);
3793 print_class_load_cause_logging();
3794 }
3795
3796 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3797 const ModuleEntry* module_entry,
3798 const ClassFileStream* cfs) const {
3799
3800 if (!log_is_enabled(Info, class, load)) {
3801 return;
3802 }
3803
3804 ResourceMark rm;
3805 LogMessage(class, load) msg;
3806 stringStream info_stream;
3807
3808 // Name and class hierarchy info
3809 info_stream.print("%s", external_name());
3810
3811 // Source
3812 if (cfs != nullptr) {
3813 if (cfs->source() != nullptr) {
3814 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3815 if (module_name != nullptr) {
3816 // When the boot loader created the stream, it didn't know the module name
3817 // yet. Let's format it now.
3818 if (cfs->from_boot_loader_modules_image()) {
3819 info_stream.print(" source: jrt:/%s", module_name);
3820 } else {
3821 info_stream.print(" source: %s", cfs->source());
3822 }
3823 } else {
3824 info_stream.print(" source: %s", cfs->source());
3825 }
3826 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3827 Thread* current = Thread::current();
3828 Klass* caller = current->is_Java_thread() ?
3829 JavaThread::cast(current)->security_get_caller_class(1):
3830 nullptr;
3831 // caller can be null, for example, during a JVMTI VM_Init hook
3832 if (caller != nullptr) {
3833 info_stream.print(" source: instance of %s", caller->external_name());
3834 } else {
3835 // source is unknown
3836 }
3837 } else {
3838 oop class_loader = loader_data->class_loader();
3839 info_stream.print(" source: %s", class_loader->klass()->external_name());
3840 }
3841 } else {
3842 assert(this->is_shared(), "must be");
3843 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3844 info_stream.print(" source: shared objects file (top)");
3845 } else {
3846 info_stream.print(" source: shared objects file");
3847 }
3848 }
3849
3850 msg.info("%s", info_stream.as_string());
3851
3852 if (log_is_enabled(Debug, class, load)) {
3853 stringStream debug_stream;
3854
3855 // Class hierarchy info
3856 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
3857 p2i(this), p2i(superklass()));
3858
3859 // Interfaces
3860 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
3861 debug_stream.print(" interfaces:");
3862 int length = local_interfaces()->length();
3863 for (int i = 0; i < length; i++) {
3864 debug_stream.print(" " PTR_FORMAT,
3865 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3866 }
3867 }
3868
3869 // Class loader
3870 debug_stream.print(" loader: [");
3871 loader_data->print_value_on(&debug_stream);
3872 debug_stream.print("]");
3873
3874 // Classfile checksum
3875 if (cfs) {
3876 debug_stream.print(" bytes: %d checksum: %08x",
3877 cfs->length(),
3878 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3879 cfs->length()));
3880 }
3881
3882 msg.debug("%s", debug_stream.as_string());
3883 }
3884 }
3885
3886 void InstanceKlass::print_class_load_cause_logging() const {
3887 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
3888 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
3889 JavaThread* current = JavaThread::current();
3890 ResourceMark rm(current);
3891 const char* name = external_name();
3892
3893 if (LogClassLoadingCauseFor == nullptr ||
3894 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
3895 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
3896 return;
3897 }
3898
3899 // Log Java stack first
3900 {
3901 LogMessage(class, load, cause) msg;
3902 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
3903
3904 info_stream.print_cr("Java stack when loading %s:", name);
3905 current->print_stack_on(&info_stream);
3906 }
3907
3908 // Log native stack second
3909 if (log_cause_native) {
3910 // Log to string first so that lines can be indented
3911 stringStream stack_stream;
3912 char buf[O_BUFLEN];
3913 address lastpc = nullptr;
3914 if (os::platform_print_native_stack(&stack_stream, nullptr, buf, O_BUFLEN, lastpc)) {
3915 // We have printed the native stack in platform-specific code,
3916 // so nothing else to do in this case.
3917 } else {
3918 frame f = os::current_frame();
3919 VMError::print_native_stack(&stack_stream, f, current, true /*print_source_info */,
3920 -1 /* max stack_stream */, buf, O_BUFLEN);
3921 }
3922
3923 LogMessage(class, load, cause, native) msg;
3924 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
3925 info_stream.print_cr("Native stack when loading %s:", name);
3926
3927 // Print each native stack line to the log
3928 int size = (int) stack_stream.size();
3929 char* stack = stack_stream.as_string();
3930 char* stack_end = stack + size;
3931 char* line_start = stack;
3932 for (char* p = stack; p < stack_end; p++) {
3933 if (*p == '\n') {
3934 *p = '\0';
3935 info_stream.print_cr("\t%s", line_start);
3936 line_start = p + 1;
3937 }
3938 }
3939 if (line_start < stack_end) {
3940 info_stream.print_cr("\t%s", line_start);
3941 }
3942 }
3943 }
3944 }
3945
3946 // Verification
3947
3948 class VerifyFieldClosure: public BasicOopIterateClosure {
3949 protected:
3950 template <class T> void do_oop_work(T* p) {
3951 oop obj = RawAccess<>::oop_load(p);
3952 if (!oopDesc::is_oop_or_null(obj)) {
3953 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3954 Universe::print_on(tty);
3955 guarantee(false, "boom");
3956 }
3957 }
3958 public:
3959 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3960 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3961 };
3962
3963 void InstanceKlass::verify_on(outputStream* st) {
3964 #ifndef PRODUCT
3965 // Avoid redundant verifies, this really should be in product.
3966 if (_verify_count == Universe::verify_count()) return;
3967 _verify_count = Universe::verify_count();
3968 #endif
3969
3970 // Verify Klass
3971 Klass::verify_on(st);
3972
3973 // Verify that klass is present in ClassLoaderData
3974 guarantee(class_loader_data()->contains_klass(this),
3975 "this class isn't found in class loader data");
3976
3977 // Verify vtables
3978 if (is_linked()) {
3979 // $$$ This used to be done only for m/s collections. Doing it
3980 // always seemed a valid generalization. (DLD -- 6/00)
3981 vtable().verify(st);
3982 }
3983
3984 // Verify first subklass
3985 if (subklass() != nullptr) {
3986 guarantee(subklass()->is_klass(), "should be klass");
3987 }
3988
3989 // Verify siblings
3990 Klass* super = this->super();
3991 Klass* sib = next_sibling();
3992 if (sib != nullptr) {
3993 if (sib == this) {
3994 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3995 }
3996
3997 guarantee(sib->is_klass(), "should be klass");
3998 guarantee(sib->super() == super, "siblings should have same superklass");
3999 }
4000
4001 // Verify local interfaces
4002 if (local_interfaces()) {
4003 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4004 for (int j = 0; j < local_interfaces->length(); j++) {
4005 InstanceKlass* e = local_interfaces->at(j);
4006 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4007 }
4008 }
4009
4010 // Verify transitive interfaces
4011 if (transitive_interfaces() != nullptr) {
4012 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4013 for (int j = 0; j < transitive_interfaces->length(); j++) {
4014 InstanceKlass* e = transitive_interfaces->at(j);
4015 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4016 }
4017 }
4018
4019 // Verify methods
4020 if (methods() != nullptr) {
4021 Array<Method*>* methods = this->methods();
4022 for (int j = 0; j < methods->length(); j++) {
4023 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4024 }
4025 for (int j = 0; j < methods->length() - 1; j++) {
4026 Method* m1 = methods->at(j);
4027 Method* m2 = methods->at(j + 1);
4028 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4029 }
4030 }
4031
4032 // Verify method ordering
4033 if (method_ordering() != nullptr) {
4034 Array<int>* method_ordering = this->method_ordering();
4035 int length = method_ordering->length();
4036 if (JvmtiExport::can_maintain_original_method_order() ||
4037 ((UseSharedSpaces || CDSConfig::is_dumping_archive()) && length != 0)) {
4038 guarantee(length == methods()->length(), "invalid method ordering length");
4039 jlong sum = 0;
4040 for (int j = 0; j < length; j++) {
4041 int original_index = method_ordering->at(j);
4042 guarantee(original_index >= 0, "invalid method ordering index");
4043 guarantee(original_index < length, "invalid method ordering index");
4044 sum += original_index;
4045 }
4046 // Verify sum of indices 0,1,...,length-1
4047 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4048 } else {
4049 guarantee(length == 0, "invalid method ordering length");
4050 }
4051 }
4052
4053 // Verify default methods
4054 if (default_methods() != nullptr) {
4055 Array<Method*>* methods = this->default_methods();
4056 for (int j = 0; j < methods->length(); j++) {
4057 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4058 }
4059 for (int j = 0; j < methods->length() - 1; j++) {
4060 Method* m1 = methods->at(j);
4061 Method* m2 = methods->at(j + 1);
4062 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4063 }
4064 }
4065
4066 // Verify JNI static field identifiers
4067 if (jni_ids() != nullptr) {
4068 jni_ids()->verify(this);
4069 }
4070
4071 // Verify other fields
4072 if (constants() != nullptr) {
4073 guarantee(constants()->is_constantPool(), "should be constant pool");
4074 }
4075 }
4076
4077 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4078 Klass::oop_verify_on(obj, st);
4079 VerifyFieldClosure blk;
4080 obj->oop_iterate(&blk);
4081 }
4082
4083
4084 // JNIid class for jfieldIDs only
4085 // Note to reviewers:
4086 // These JNI functions are just moved over to column 1 and not changed
4087 // in the compressed oops workspace.
4088 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
4089 _holder = holder;
4090 _offset = offset;
4091 _next = next;
4092 debug_only(_is_static_field_id = false;)
4093 }
4094
4095
4096 JNIid* JNIid::find(int offset) {
4097 JNIid* current = this;
4098 while (current != nullptr) {
4099 if (current->offset() == offset) return current;
4100 current = current->next();
4101 }
4102 return nullptr;
4103 }
4104
4105 void JNIid::deallocate(JNIid* current) {
4106 while (current != nullptr) {
4107 JNIid* next = current->next();
4108 delete current;
4109 current = next;
4110 }
4111 }
4112
4113
4114 void JNIid::verify(Klass* holder) {
4115 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4116 int end_field_offset;
4117 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
4118
4119 JNIid* current = this;
4120 while (current != nullptr) {
4121 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4122 #ifdef ASSERT
4123 int o = current->offset();
4124 if (current->is_static_field_id()) {
4125 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4126 }
4127 #endif
4128 current = current->next();
4129 }
4130 }
4131
4132 void InstanceKlass::set_init_state(ClassState state) {
4133 if (state > loaded) {
4134 assert_lock_strong(_init_monitor);
4135 }
4136 #ifdef ASSERT
4137 bool good_state = is_shared() ? (_init_state <= state)
4138 : (_init_state < state);
4139 bool link_failed = _init_state == being_linked && state == loaded;
4140 assert(good_state || state == allocated || link_failed, "illegal state transition");
4141 #endif
4142 assert(_init_thread == nullptr, "should be cleared before state change");
4143 Atomic::store(&_init_state, state);
4144 }
4145
4146 #if INCLUDE_JVMTI
4147
4148 // RedefineClasses() support for previous versions
4149
4150 // Globally, there is at least one previous version of a class to walk
4151 // during class unloading, which is saved because old methods in the class
4152 // are still running. Otherwise the previous version list is cleaned up.
4153 bool InstanceKlass::_should_clean_previous_versions = false;
4154
4155 // Returns true if there are previous versions of a class for class
4156 // unloading only. Also resets the flag to false. purge_previous_version
4157 // will set the flag to true if there are any left, i.e., if there's any
4158 // work to do for next time. This is to avoid the expensive code cache
4159 // walk in CLDG::clean_deallocate_lists().
4160 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4161 bool ret = _should_clean_previous_versions;
4162 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4163 ret ? "true" : "false");
4164 _should_clean_previous_versions = false;
4165 return ret;
4166 }
4167
4168 // This nulls out jmethodIDs for all methods in 'klass'
4169 // It needs to be called explicitly for all previous versions of a class because these may not be cleaned up
4170 // during class unloading.
4171 // We can not use the jmethodID cache associated with klass directly because the 'previous' versions
4172 // do not have the jmethodID cache filled in. Instead, we need to lookup jmethodID for each method and this
4173 // is expensive - O(n) for one jmethodID lookup. For all contained methods it is O(n^2).
4174 // The reason for expensive jmethodID lookup for each method is that there is no direct link between method and jmethodID.
4175 void InstanceKlass::clear_jmethod_ids(InstanceKlass* klass) {
4176 Array<Method*>* method_refs = klass->methods();
4177 for (int k = 0; k < method_refs->length(); k++) {
4178 Method* method = method_refs->at(k);
4179 if (method != nullptr && method->is_obsolete()) {
4180 method->clear_jmethod_id();
4181 }
4182 }
4183 }
4184
4185 // Purge previous versions before adding new previous versions of the class and
4186 // during class unloading.
4187 void InstanceKlass::purge_previous_version_list() {
4188 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4189 assert(has_been_redefined(), "Should only be called for main class");
4190
4191 // Quick exit.
4192 if (previous_versions() == nullptr) {
4193 return;
4194 }
4195
4196 // This klass has previous versions so see what we can cleanup
4197 // while it is safe to do so.
4198
4199 int deleted_count = 0; // leave debugging breadcrumbs
4200 int live_count = 0;
4201 ClassLoaderData* loader_data = class_loader_data();
4202 assert(loader_data != nullptr, "should never be null");
4203
4204 ResourceMark rm;
4205 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4206
4207 // previous versions are linked together through the InstanceKlass
4208 InstanceKlass* pv_node = previous_versions();
4209 InstanceKlass* last = this;
4210 int version = 0;
4211
4212 // check the previous versions list
4213 for (; pv_node != nullptr; ) {
4214
4215 ConstantPool* pvcp = pv_node->constants();
4216 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4217
4218 if (!pvcp->on_stack()) {
4219 // If the constant pool isn't on stack, none of the methods
4220 // are executing. Unlink this previous_version.
4221 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4222 // so will be deallocated during the next phase of class unloading.
4223 log_trace(redefine, class, iklass, purge)
4224 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4225 // Unlink from previous version list.
4226 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4227 InstanceKlass* next = pv_node->previous_versions();
4228 clear_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4229 pv_node->link_previous_versions(nullptr); // point next to null
4230 last->link_previous_versions(next);
4231 // Delete this node directly. Nothing is referring to it and we don't
4232 // want it to increase the counter for metadata to delete in CLDG.
4233 MetadataFactory::free_metadata(loader_data, pv_node);
4234 pv_node = next;
4235 deleted_count++;
4236 version++;
4237 continue;
4238 } else {
4239 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4240 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4241 live_count++;
4242 if (pvcp->is_shared()) {
4243 // Shared previous versions can never be removed so no cleaning is needed.
4244 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4245 } else {
4246 // Previous version alive, set that clean is needed for next time.
4247 _should_clean_previous_versions = true;
4248 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4249 }
4250 }
4251
4252 // next previous version
4253 last = pv_node;
4254 pv_node = pv_node->previous_versions();
4255 version++;
4256 }
4257 log_trace(redefine, class, iklass, purge)
4258 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4259 }
4260
4261 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4262 int emcp_method_count) {
4263 int obsolete_method_count = old_methods->length() - emcp_method_count;
4264
4265 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4266 _previous_versions != nullptr) {
4267 // We have a mix of obsolete and EMCP methods so we have to
4268 // clear out any matching EMCP method entries the hard way.
4269 int local_count = 0;
4270 for (int i = 0; i < old_methods->length(); i++) {
4271 Method* old_method = old_methods->at(i);
4272 if (old_method->is_obsolete()) {
4273 // only obsolete methods are interesting
4274 Symbol* m_name = old_method->name();
4275 Symbol* m_signature = old_method->signature();
4276
4277 // previous versions are linked together through the InstanceKlass
4278 int j = 0;
4279 for (InstanceKlass* prev_version = _previous_versions;
4280 prev_version != nullptr;
4281 prev_version = prev_version->previous_versions(), j++) {
4282
4283 Array<Method*>* method_refs = prev_version->methods();
4284 for (int k = 0; k < method_refs->length(); k++) {
4285 Method* method = method_refs->at(k);
4286
4287 if (!method->is_obsolete() &&
4288 method->name() == m_name &&
4289 method->signature() == m_signature) {
4290 // The current RedefineClasses() call has made all EMCP
4291 // versions of this method obsolete so mark it as obsolete
4292 log_trace(redefine, class, iklass, add)
4293 ("%s(%s): flush obsolete method @%d in version @%d",
4294 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4295
4296 method->set_is_obsolete();
4297 break;
4298 }
4299 }
4300
4301 // The previous loop may not find a matching EMCP method, but
4302 // that doesn't mean that we can optimize and not go any
4303 // further back in the PreviousVersion generations. The EMCP
4304 // method for this generation could have already been made obsolete,
4305 // but there still may be an older EMCP method that has not
4306 // been made obsolete.
4307 }
4308
4309 if (++local_count >= obsolete_method_count) {
4310 // no more obsolete methods so bail out now
4311 break;
4312 }
4313 }
4314 }
4315 }
4316 }
4317
4318 // Save the scratch_class as the previous version if any of the methods are running.
4319 // The previous_versions are used to set breakpoints in EMCP methods and they are
4320 // also used to clean MethodData links to redefined methods that are no longer running.
4321 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4322 int emcp_method_count) {
4323 assert(Thread::current()->is_VM_thread(),
4324 "only VMThread can add previous versions");
4325
4326 ResourceMark rm;
4327 log_trace(redefine, class, iklass, add)
4328 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4329
4330 // Clean out old previous versions for this class
4331 purge_previous_version_list();
4332
4333 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4334 // a previous redefinition may be made obsolete by this redefinition.
4335 Array<Method*>* old_methods = scratch_class->methods();
4336 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4337
4338 // If the constant pool for this previous version of the class
4339 // is not marked as being on the stack, then none of the methods
4340 // in this previous version of the class are on the stack so
4341 // we don't need to add this as a previous version.
4342 ConstantPool* cp_ref = scratch_class->constants();
4343 if (!cp_ref->on_stack()) {
4344 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4345 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4346 return;
4347 }
4348
4349 // Add previous version if any methods are still running or if this is
4350 // a shared class which should never be removed.
4351 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4352 scratch_class->link_previous_versions(previous_versions());
4353 link_previous_versions(scratch_class);
4354 if (cp_ref->is_shared()) {
4355 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4356 } else {
4357 // We only set clean_previous_versions flag for processing during class
4358 // unloading for non-shared classes.
4359 _should_clean_previous_versions = true;
4360 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4361 }
4362 } // end add_previous_version()
4363
4364 #endif // INCLUDE_JVMTI
4365
4366 Method* InstanceKlass::method_with_idnum(int idnum) {
4367 Method* m = nullptr;
4368 if (idnum < methods()->length()) {
4369 m = methods()->at(idnum);
4370 }
4371 if (m == nullptr || m->method_idnum() != idnum) {
4372 for (int index = 0; index < methods()->length(); ++index) {
4373 m = methods()->at(index);
4374 if (m->method_idnum() == idnum) {
4375 return m;
4376 }
4377 }
4378 // None found, return null for the caller to handle.
4379 return nullptr;
4380 }
4381 return m;
4382 }
4383
4384
4385 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4386 if (idnum >= methods()->length()) {
4387 return nullptr;
4388 }
4389 Method* m = methods()->at(idnum);
4390 if (m != nullptr && m->orig_method_idnum() == idnum) {
4391 return m;
4392 }
4393 // Obsolete method idnum does not match the original idnum
4394 for (int index = 0; index < methods()->length(); ++index) {
4395 m = methods()->at(index);
4396 if (m->orig_method_idnum() == idnum) {
4397 return m;
4398 }
4399 }
4400 // None found, return null for the caller to handle.
4401 return nullptr;
4402 }
4403
4404
4405 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4406 InstanceKlass* holder = get_klass_version(version);
4407 if (holder == nullptr) {
4408 return nullptr; // The version of klass is gone, no method is found
4409 }
4410 Method* method = holder->method_with_orig_idnum(idnum);
4411 return method;
4412 }
4413
4414 #if INCLUDE_JVMTI
4415 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4416 return _cached_class_file;
4417 }
4418
4419 jint InstanceKlass::get_cached_class_file_len() {
4420 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4421 }
4422
4423 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4424 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4425 }
4426 #endif
4427
4428 // Make a step iterating over the class hierarchy under the root class.
4429 // Skips subclasses if requested.
4430 void ClassHierarchyIterator::next() {
4431 assert(_current != nullptr, "required");
4432 if (_visit_subclasses && _current->subklass() != nullptr) {
4433 _current = _current->subklass();
4434 return; // visit next subclass
4435 }
4436 _visit_subclasses = true; // reset
4437 while (_current->next_sibling() == nullptr && _current != _root) {
4438 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4439 }
4440 if (_current == _root) {
4441 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4442 _current = nullptr;
4443 return;
4444 }
4445 _current = _current->next_sibling();
4446 return; // visit next sibling subclass
4447 }