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 Array<InstanceKlass*>* interfaces = transitive_interfaces;
1431 int num_secondaries = num_extra_slots + interfaces->length();
1432 if (num_secondaries == 0) {
1433 // Must share this for correct bootstrapping!
1434 set_secondary_supers(Universe::the_empty_klass_array());
1435 return nullptr;
1436 } else if (num_extra_slots == 0) {
1437 // The secondary super list is exactly the same as the transitive interfaces, so
1438 // let's use it instead of making a copy.
1439 // Redefine classes has to be careful not to delete this!
1440 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1441 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1442 set_secondary_supers((Array<Klass*>*)(address)interfaces);
1443 return nullptr;
1444 } else {
1445 // Copy transitive interfaces to a temporary growable array to be constructed
1446 // into the secondary super list with extra slots.
1447 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1448 for (int i = 0; i < interfaces->length(); i++) {
1449 secondaries->push(interfaces->at(i));
1450 }
1451 return secondaries;
1452 }
1453 }
1454
1455 bool InstanceKlass::implements_interface(Klass* k) const {
1456 if (this == k) return true;
1457 assert(k->is_interface(), "should be an interface class");
1458 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1459 if (transitive_interfaces()->at(i) == k) {
1460 return true;
1461 }
1462 }
1463 return false;
1464 }
1465
1466 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1467 // Verify direct super interface
1468 if (this == k) return true;
1469 assert(k->is_interface(), "should be an interface class");
1470 for (int i = 0; i < local_interfaces()->length(); i++) {
1471 if (local_interfaces()->at(i) == k) {
1472 return true;
1473 }
1474 }
1475 return false;
1476 }
1477
1478 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1479 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1480 size_t size = objArrayOopDesc::object_size(length);
1481 ArrayKlass* ak = array_klass(n, CHECK_NULL);
1482 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1483 /* do_zero */ true, CHECK_NULL);
1484 return o;
1485 }
1486
1487 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1488 if (TraceFinalizerRegistration) {
1489 tty->print("Registered ");
1490 i->print_value_on(tty);
1491 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1492 }
1493 instanceHandle h_i(THREAD, i);
1494 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1495 JavaValue result(T_VOID);
1496 JavaCallArguments args(h_i);
1497 methodHandle mh(THREAD, Universe::finalizer_register_method());
1498 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1499 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1500 return h_i();
1501 }
1502
1503 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1504 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1505 size_t size = size_helper(); // Query before forming handle.
1506
1507 instanceOop i;
1508
1509 i = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1510 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1511 i = register_finalizer(i, CHECK_NULL);
1512 }
1513 return i;
1514 }
1515
1516 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1517 Klass* k = java_lang_Class::as_Klass(java_class);
1518 if (k == nullptr) {
1519 ResourceMark rm(THREAD);
1520 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1521 }
1522 InstanceKlass* ik = cast(k);
1523 ik->check_valid_for_instantiation(false, CHECK_NULL);
1524 ik->initialize(CHECK_NULL);
1525 return ik->allocate_instance(THREAD);
1526 }
1527
1528 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1529 return instanceHandle(THREAD, allocate_instance(THREAD));
1530 }
1531
1532 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1533 if (is_interface() || is_abstract()) {
1534 ResourceMark rm(THREAD);
1535 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1536 : vmSymbols::java_lang_InstantiationException(), external_name());
1537 }
1538 if (this == vmClasses::Class_klass()) {
1539 ResourceMark rm(THREAD);
1540 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1541 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1542 }
1543 }
1544
1545 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1546 // Need load-acquire for lock-free read
1547 if (array_klasses_acquire() == nullptr) {
1548
1549 // Recursively lock array allocation
1550 RecursiveLocker rl(MultiArray_lock, THREAD);
1551
1552 // Check if another thread created the array klass while we were waiting for the lock.
1553 if (array_klasses() == nullptr) {
1554 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1555 // use 'release' to pair with lock-free load
1556 release_set_array_klasses(k);
1557 }
1558 }
1559
1560 // array_klasses() will always be set at this point
1561 ObjArrayKlass* ak = array_klasses();
1562 assert(ak != nullptr, "should be set");
1563 return ak->array_klass(n, THREAD);
1564 }
1565
1566 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1567 // Need load-acquire for lock-free read
1568 ObjArrayKlass* oak = array_klasses_acquire();
1569 if (oak == nullptr) {
1570 return nullptr;
1571 } else {
1572 return oak->array_klass_or_null(n);
1573 }
1574 }
1575
1576 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1577 return array_klass(1, THREAD);
1578 }
1579
1580 ArrayKlass* InstanceKlass::array_klass_or_null() {
1581 return array_klass_or_null(1);
1582 }
1583
1584 static int call_class_initializer_counter = 0; // for debugging
1585
1586 Method* InstanceKlass::class_initializer() const {
1587 Method* clinit = find_method(
1588 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1589 if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1590 return clinit;
1591 }
1592 return nullptr;
1593 }
1594
1595 void InstanceKlass::call_class_initializer(TRAPS) {
1596 if (ReplayCompiles &&
1597 (ReplaySuppressInitializers == 1 ||
1598 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1599 // Hide the existence of the initializer for the purpose of replaying the compile
1600 return;
1601 }
1602
1603 #if INCLUDE_CDS
1604 // This is needed to ensure the consistency of the archived heap objects.
1605 if (has_archived_enum_objs()) {
1606 assert(is_shared(), "must be");
1607 bool initialized = HeapShared::initialize_enum_klass(this, CHECK);
1608 if (initialized) {
1609 return;
1610 }
1611 }
1612 #endif
1613
1614 methodHandle h_method(THREAD, class_initializer());
1615 assert(!is_initialized(), "we cannot initialize twice");
1616 LogTarget(Info, class, init) lt;
1617 if (lt.is_enabled()) {
1618 ResourceMark rm(THREAD);
1619 LogStream ls(lt);
1620 ls.print("%d Initializing ", call_class_initializer_counter++);
1621 name()->print_value_on(&ls);
1622 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1623 h_method() == nullptr ? "(no method)" : "", p2i(this),
1624 THREAD->name());
1625 }
1626 if (h_method() != nullptr) {
1627 JavaCallArguments args; // No arguments
1628 JavaValue result(T_VOID);
1629 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1630 }
1631 }
1632
1633
1634 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1635 InterpreterOopMap* entry_for) {
1636 // Lazily create the _oop_map_cache at first request
1637 // Lock-free access requires load_acquire.
1638 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1639 if (oop_map_cache == nullptr) {
1640 MutexLocker x(OopMapCacheAlloc_lock);
1641 // Check if _oop_map_cache was allocated while we were waiting for this lock
1642 if ((oop_map_cache = _oop_map_cache) == nullptr) {
1643 oop_map_cache = new OopMapCache();
1644 // Ensure _oop_map_cache is stable, since it is examined without a lock
1645 Atomic::release_store(&_oop_map_cache, oop_map_cache);
1646 }
1647 }
1648 // _oop_map_cache is constant after init; lookup below does its own locking.
1649 oop_map_cache->lookup(method, bci, entry_for);
1650 }
1651
1652 bool InstanceKlass::contains_field_offset(int offset) {
1653 fieldDescriptor fd;
1654 return find_field_from_offset(offset, false, &fd);
1655 }
1656
1657 FieldInfo InstanceKlass::field(int index) const {
1658 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1659 if (fs.index() == index) {
1660 return fs.to_FieldInfo();
1661 }
1662 }
1663 fatal("Field not found");
1664 return FieldInfo();
1665 }
1666
1667 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1668 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1669 Symbol* f_name = fs.name();
1670 Symbol* f_sig = fs.signature();
1671 if (f_name == name && f_sig == sig) {
1672 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1673 return true;
1674 }
1675 }
1676 return false;
1677 }
1678
1679
1680 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1681 const int n = local_interfaces()->length();
1682 for (int i = 0; i < n; i++) {
1683 Klass* intf1 = local_interfaces()->at(i);
1684 assert(intf1->is_interface(), "just checking type");
1685 // search for field in current interface
1686 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1687 assert(fd->is_static(), "interface field must be static");
1688 return intf1;
1689 }
1690 // search for field in direct superinterfaces
1691 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1692 if (intf2 != nullptr) return intf2;
1693 }
1694 // otherwise field lookup fails
1695 return nullptr;
1696 }
1697
1698
1699 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1700 // search order according to newest JVM spec (5.4.3.2, p.167).
1701 // 1) search for field in current klass
1702 if (find_local_field(name, sig, fd)) {
1703 return const_cast<InstanceKlass*>(this);
1704 }
1705 // 2) search for field recursively in direct superinterfaces
1706 { Klass* intf = find_interface_field(name, sig, fd);
1707 if (intf != nullptr) return intf;
1708 }
1709 // 3) apply field lookup recursively if superclass exists
1710 { Klass* supr = super();
1711 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1712 }
1713 // 4) otherwise field lookup fails
1714 return nullptr;
1715 }
1716
1717
1718 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1719 // search order according to newest JVM spec (5.4.3.2, p.167).
1720 // 1) search for field in current klass
1721 if (find_local_field(name, sig, fd)) {
1722 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1723 }
1724 // 2) search for field recursively in direct superinterfaces
1725 if (is_static) {
1726 Klass* intf = find_interface_field(name, sig, fd);
1727 if (intf != nullptr) return intf;
1728 }
1729 // 3) apply field lookup recursively if superclass exists
1730 { Klass* supr = super();
1731 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1732 }
1733 // 4) otherwise field lookup fails
1734 return nullptr;
1735 }
1736
1737
1738 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1739 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1740 if (fs.offset() == offset) {
1741 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1742 if (fd->is_static() == is_static) return true;
1743 }
1744 }
1745 return false;
1746 }
1747
1748
1749 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1750 Klass* klass = const_cast<InstanceKlass*>(this);
1751 while (klass != nullptr) {
1752 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1753 return true;
1754 }
1755 klass = klass->super();
1756 }
1757 return false;
1758 }
1759
1760
1761 void InstanceKlass::methods_do(void f(Method* method)) {
1762 // Methods aren't stable until they are loaded. This can be read outside
1763 // a lock through the ClassLoaderData for profiling
1764 // Redefined scratch classes are on the list and need to be cleaned
1765 if (!is_loaded() && !is_scratch_class()) {
1766 return;
1767 }
1768
1769 int len = methods()->length();
1770 for (int index = 0; index < len; index++) {
1771 Method* m = methods()->at(index);
1772 assert(m->is_method(), "must be method");
1773 f(m);
1774 }
1775 }
1776
1777
1778 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1779 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1780 if (fs.access_flags().is_static()) {
1781 fieldDescriptor& fd = fs.field_descriptor();
1782 cl->do_field(&fd);
1783 }
1784 }
1785 }
1786
1787
1788 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1789 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1790 if (fs.access_flags().is_static()) {
1791 fieldDescriptor& fd = fs.field_descriptor();
1792 f(&fd, mirror, CHECK);
1793 }
1794 }
1795 }
1796
1797 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1798 InstanceKlass* super = superklass();
1799 if (super != nullptr) {
1800 super->do_nonstatic_fields(cl);
1801 }
1802 fieldDescriptor fd;
1803 int length = java_fields_count();
1804 for (int i = 0; i < length; i += 1) {
1805 fd.reinitialize(this, i);
1806 if (!fd.is_static()) {
1807 cl->do_field(&fd);
1808 }
1809 }
1810 }
1811
1812 // first in Pair is offset, second is index.
1813 static int compare_fields_by_offset(Pair<int,int>* a, Pair<int,int>* b) {
1814 return a->first - b->first;
1815 }
1816
1817 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1818 InstanceKlass* super = superklass();
1819 if (super != nullptr) {
1820 super->print_nonstatic_fields(cl);
1821 }
1822 ResourceMark rm;
1823 fieldDescriptor fd;
1824 // In DebugInfo nonstatic fields are sorted by offset.
1825 GrowableArray<Pair<int,int> > fields_sorted;
1826 int i = 0;
1827 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1828 if (!fs.access_flags().is_static()) {
1829 fd = fs.field_descriptor();
1830 Pair<int,int> f(fs.offset(), fs.index());
1831 fields_sorted.push(f);
1832 i++;
1833 }
1834 }
1835 if (i > 0) {
1836 int length = i;
1837 assert(length == fields_sorted.length(), "duh");
1838 fields_sorted.sort(compare_fields_by_offset);
1839 for (int i = 0; i < length; i++) {
1840 fd.reinitialize(this, fields_sorted.at(i).second);
1841 assert(!fd.is_static() && fd.offset() == fields_sorted.at(i).first, "only nonstatic fields");
1842 cl->do_field(&fd);
1843 }
1844 }
1845 }
1846
1847 #ifdef ASSERT
1848 static int linear_search(const Array<Method*>* methods,
1849 const Symbol* name,
1850 const Symbol* signature) {
1851 const int len = methods->length();
1852 for (int index = 0; index < len; index++) {
1853 const Method* const m = methods->at(index);
1854 assert(m->is_method(), "must be method");
1855 if (m->signature() == signature && m->name() == name) {
1856 return index;
1857 }
1858 }
1859 return -1;
1860 }
1861 #endif
1862
1863 bool InstanceKlass::_disable_method_binary_search = false;
1864
1865 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1866 int len = methods->length();
1867 int l = 0;
1868 int h = len - 1;
1869 while (l <= h) {
1870 Method* m = methods->at(l);
1871 if (m->name() == name) {
1872 return l;
1873 }
1874 l++;
1875 }
1876 return -1;
1877 }
1878
1879 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1880 if (_disable_method_binary_search) {
1881 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1882 // At the final stage of dynamic dumping, the methods array may not be sorted
1883 // by ascending addresses of their names, so we can't use binary search anymore.
1884 // However, methods with the same name are still laid out consecutively inside the
1885 // methods array, so let's look for the first one that matches.
1886 return linear_search(methods, name);
1887 }
1888
1889 int len = methods->length();
1890 int l = 0;
1891 int h = len - 1;
1892
1893 // methods are sorted by ascending addresses of their names, so do binary search
1894 while (l <= h) {
1895 int mid = (l + h) >> 1;
1896 Method* m = methods->at(mid);
1897 assert(m->is_method(), "must be method");
1898 int res = m->name()->fast_compare(name);
1899 if (res == 0) {
1900 return mid;
1901 } else if (res < 0) {
1902 l = mid + 1;
1903 } else {
1904 h = mid - 1;
1905 }
1906 }
1907 return -1;
1908 }
1909
1910 // find_method looks up the name/signature in the local methods array
1911 Method* InstanceKlass::find_method(const Symbol* name,
1912 const Symbol* signature) const {
1913 return find_method_impl(name, signature,
1914 OverpassLookupMode::find,
1915 StaticLookupMode::find,
1916 PrivateLookupMode::find);
1917 }
1918
1919 Method* InstanceKlass::find_method_impl(const Symbol* name,
1920 const Symbol* signature,
1921 OverpassLookupMode overpass_mode,
1922 StaticLookupMode static_mode,
1923 PrivateLookupMode private_mode) const {
1924 return InstanceKlass::find_method_impl(methods(),
1925 name,
1926 signature,
1927 overpass_mode,
1928 static_mode,
1929 private_mode);
1930 }
1931
1932 // find_instance_method looks up the name/signature in the local methods array
1933 // and skips over static methods
1934 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1935 const Symbol* name,
1936 const Symbol* signature,
1937 PrivateLookupMode private_mode) {
1938 Method* const meth = InstanceKlass::find_method_impl(methods,
1939 name,
1940 signature,
1941 OverpassLookupMode::find,
1942 StaticLookupMode::skip,
1943 private_mode);
1944 assert(((meth == nullptr) || !meth->is_static()),
1945 "find_instance_method should have skipped statics");
1946 return meth;
1947 }
1948
1949 // find_instance_method looks up the name/signature in the local methods array
1950 // and skips over static methods
1951 Method* InstanceKlass::find_instance_method(const Symbol* name,
1952 const Symbol* signature,
1953 PrivateLookupMode private_mode) const {
1954 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1955 }
1956
1957 // Find looks up the name/signature in the local methods array
1958 // and filters on the overpass, static and private flags
1959 // This returns the first one found
1960 // note that the local methods array can have up to one overpass, one static
1961 // and one instance (private or not) with the same name/signature
1962 Method* InstanceKlass::find_local_method(const Symbol* name,
1963 const Symbol* signature,
1964 OverpassLookupMode overpass_mode,
1965 StaticLookupMode static_mode,
1966 PrivateLookupMode private_mode) const {
1967 return InstanceKlass::find_method_impl(methods(),
1968 name,
1969 signature,
1970 overpass_mode,
1971 static_mode,
1972 private_mode);
1973 }
1974
1975 // Find looks up the name/signature in the local methods array
1976 // and filters on the overpass, static and private flags
1977 // This returns the first one found
1978 // note that the local methods array can have up to one overpass, one static
1979 // and one instance (private or not) with the same name/signature
1980 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1981 const Symbol* name,
1982 const Symbol* signature,
1983 OverpassLookupMode overpass_mode,
1984 StaticLookupMode static_mode,
1985 PrivateLookupMode private_mode) {
1986 return InstanceKlass::find_method_impl(methods,
1987 name,
1988 signature,
1989 overpass_mode,
1990 static_mode,
1991 private_mode);
1992 }
1993
1994 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1995 const Symbol* name,
1996 const Symbol* signature) {
1997 return InstanceKlass::find_method_impl(methods,
1998 name,
1999 signature,
2000 OverpassLookupMode::find,
2001 StaticLookupMode::find,
2002 PrivateLookupMode::find);
2003 }
2004
2005 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2006 const Symbol* name,
2007 const Symbol* signature,
2008 OverpassLookupMode overpass_mode,
2009 StaticLookupMode static_mode,
2010 PrivateLookupMode private_mode) {
2011 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2012 return hit >= 0 ? methods->at(hit): nullptr;
2013 }
2014
2015 // true if method matches signature and conforms to skipping_X conditions.
2016 static bool method_matches(const Method* m,
2017 const Symbol* signature,
2018 bool skipping_overpass,
2019 bool skipping_static,
2020 bool skipping_private) {
2021 return ((m->signature() == signature) &&
2022 (!skipping_overpass || !m->is_overpass()) &&
2023 (!skipping_static || !m->is_static()) &&
2024 (!skipping_private || !m->is_private()));
2025 }
2026
2027 // Used directly for default_methods to find the index into the
2028 // default_vtable_indices, and indirectly by find_method
2029 // find_method_index looks in the local methods array to return the index
2030 // of the matching name/signature. If, overpass methods are being ignored,
2031 // the search continues to find a potential non-overpass match. This capability
2032 // is important during method resolution to prefer a static method, for example,
2033 // over an overpass method.
2034 // There is the possibility in any _method's array to have the same name/signature
2035 // for a static method, an overpass method and a local instance method
2036 // To correctly catch a given method, the search criteria may need
2037 // to explicitly skip the other two. For local instance methods, it
2038 // is often necessary to skip private methods
2039 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2040 const Symbol* name,
2041 const Symbol* signature,
2042 OverpassLookupMode overpass_mode,
2043 StaticLookupMode static_mode,
2044 PrivateLookupMode private_mode) {
2045 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2046 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2047 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2048 const int hit = quick_search(methods, name);
2049 if (hit != -1) {
2050 const Method* const m = methods->at(hit);
2051
2052 // Do linear search to find matching signature. First, quick check
2053 // for common case, ignoring overpasses if requested.
2054 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2055 return hit;
2056 }
2057
2058 // search downwards through overloaded methods
2059 int i;
2060 for (i = hit - 1; i >= 0; --i) {
2061 const Method* const m = methods->at(i);
2062 assert(m->is_method(), "must be method");
2063 if (m->name() != name) {
2064 break;
2065 }
2066 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2067 return i;
2068 }
2069 }
2070 // search upwards
2071 for (i = hit + 1; i < methods->length(); ++i) {
2072 const Method* const m = methods->at(i);
2073 assert(m->is_method(), "must be method");
2074 if (m->name() != name) {
2075 break;
2076 }
2077 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2078 return i;
2079 }
2080 }
2081 // not found
2082 #ifdef ASSERT
2083 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2084 linear_search(methods, name, signature);
2085 assert(-1 == index, "binary search should have found entry %d", index);
2086 #endif
2087 }
2088 return -1;
2089 }
2090
2091 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2092 return find_method_by_name(methods(), name, end);
2093 }
2094
2095 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2096 const Symbol* name,
2097 int* end_ptr) {
2098 assert(end_ptr != nullptr, "just checking");
2099 int start = quick_search(methods, name);
2100 int end = start + 1;
2101 if (start != -1) {
2102 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2103 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2104 *end_ptr = end;
2105 return start;
2106 }
2107 return -1;
2108 }
2109
2110 // uncached_lookup_method searches both the local class methods array and all
2111 // superclasses methods arrays, skipping any overpass methods in superclasses,
2112 // and possibly skipping private methods.
2113 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2114 const Symbol* signature,
2115 OverpassLookupMode overpass_mode,
2116 PrivateLookupMode private_mode) const {
2117 OverpassLookupMode overpass_local_mode = overpass_mode;
2118 const Klass* klass = this;
2119 while (klass != nullptr) {
2120 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
2121 signature,
2122 overpass_local_mode,
2123 StaticLookupMode::find,
2124 private_mode);
2125 if (method != nullptr) {
2126 return method;
2127 }
2128 klass = klass->super();
2129 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2130 }
2131 return nullptr;
2132 }
2133
2134 #ifdef ASSERT
2135 // search through class hierarchy and return true if this class or
2136 // one of the superclasses was redefined
2137 bool InstanceKlass::has_redefined_this_or_super() const {
2138 const Klass* klass = this;
2139 while (klass != nullptr) {
2140 if (InstanceKlass::cast(klass)->has_been_redefined()) {
2141 return true;
2142 }
2143 klass = klass->super();
2144 }
2145 return false;
2146 }
2147 #endif
2148
2149 // lookup a method in the default methods list then in all transitive interfaces
2150 // Do NOT return private or static methods
2151 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2152 Symbol* signature) const {
2153 Method* m = nullptr;
2154 if (default_methods() != nullptr) {
2155 m = find_method(default_methods(), name, signature);
2156 }
2157 // Look up interfaces
2158 if (m == nullptr) {
2159 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2160 }
2161 return m;
2162 }
2163
2164 // lookup a method in all the interfaces that this class implements
2165 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2166 // They should only be found in the initial InterfaceMethodRef
2167 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2168 Symbol* signature,
2169 DefaultsLookupMode defaults_mode) const {
2170 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2171 int num_ifs = all_ifs->length();
2172 InstanceKlass *ik = nullptr;
2173 for (int i = 0; i < num_ifs; i++) {
2174 ik = all_ifs->at(i);
2175 Method* m = ik->lookup_method(name, signature);
2176 if (m != nullptr && m->is_public() && !m->is_static() &&
2177 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2178 return m;
2179 }
2180 }
2181 return nullptr;
2182 }
2183
2184 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2185 :_st(st), _verbose(verbose) {
2186 ResourceMark rm;
2187 _st->print("%-18s ", "KlassAddr");
2188 _st->print("%-4s ", "Size");
2189 _st->print("%-20s ", "State");
2190 _st->print("%-7s ", "Flags");
2191 _st->print("%-5s ", "ClassName");
2192 _st->cr();
2193 }
2194
2195 void PrintClassClosure::do_klass(Klass* k) {
2196 ResourceMark rm;
2197 // klass pointer
2198 _st->print(PTR_FORMAT " ", p2i(k));
2199 // klass size
2200 _st->print("%4d ", k->size());
2201 // initialization state
2202 if (k->is_instance_klass()) {
2203 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2204 } else {
2205 _st->print("%-20s ","");
2206 }
2207 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2208 char buf[10];
2209 int i = 0;
2210 if (k->has_finalizer()) buf[i++] = 'F';
2211 if (k->is_instance_klass()) {
2212 InstanceKlass* ik = InstanceKlass::cast(k);
2213 if (ik->has_final_method()) buf[i++] = 'f';
2214 if (ik->is_rewritten()) buf[i++] = 'W';
2215 if (ik->is_contended()) buf[i++] = 'C';
2216 if (ik->has_been_redefined()) buf[i++] = 'R';
2217 if (ik->is_shared()) buf[i++] = 'S';
2218 }
2219 buf[i++] = '\0';
2220 _st->print("%-7s ", buf);
2221 // klass name
2222 _st->print("%-5s ", k->external_name());
2223 // end
2224 _st->cr();
2225 if (_verbose) {
2226 k->print_on(_st);
2227 }
2228 }
2229
2230 /* jni_id_for for jfieldIds only */
2231 JNIid* InstanceKlass::jni_id_for(int offset) {
2232 MutexLocker ml(JfieldIdCreation_lock);
2233 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2234 if (probe == nullptr) {
2235 // Allocate new static field identifier
2236 probe = new JNIid(this, offset, jni_ids());
2237 set_jni_ids(probe);
2238 }
2239 return probe;
2240 }
2241
2242 u2 InstanceKlass::enclosing_method_data(int offset) const {
2243 const Array<jushort>* const inner_class_list = inner_classes();
2244 if (inner_class_list == nullptr) {
2245 return 0;
2246 }
2247 const int length = inner_class_list->length();
2248 if (length % inner_class_next_offset == 0) {
2249 return 0;
2250 }
2251 const int index = length - enclosing_method_attribute_size;
2252 assert(offset < enclosing_method_attribute_size, "invalid offset");
2253 return inner_class_list->at(index + offset);
2254 }
2255
2256 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2257 u2 method_index) {
2258 Array<jushort>* inner_class_list = inner_classes();
2259 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2260 int length = inner_class_list->length();
2261 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2262 int index = length - enclosing_method_attribute_size;
2263 inner_class_list->at_put(
2264 index + enclosing_method_class_index_offset, class_index);
2265 inner_class_list->at_put(
2266 index + enclosing_method_method_index_offset, method_index);
2267 }
2268 }
2269
2270 // Lookup or create a jmethodID.
2271 // This code is called by the VMThread and JavaThreads so the
2272 // locking has to be done very carefully to avoid deadlocks
2273 // and/or other cache consistency problems.
2274 //
2275 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2276 size_t idnum = (size_t)method_h->method_idnum();
2277 jmethodID* jmeths = methods_jmethod_ids_acquire();
2278 size_t length = 0;
2279 jmethodID id = nullptr;
2280
2281 // We use a double-check locking idiom here because this cache is
2282 // performance sensitive. In the normal system, this cache only
2283 // transitions from null to non-null which is safe because we use
2284 // release_set_methods_jmethod_ids() to advertise the new cache.
2285 // A partially constructed cache should never be seen by a racing
2286 // thread. We also use release_store() to save a new jmethodID
2287 // in the cache so a partially constructed jmethodID should never be
2288 // seen either. Cache reads of existing jmethodIDs proceed without a
2289 // lock, but cache writes of a new jmethodID requires uniqueness and
2290 // creation of the cache itself requires no leaks so a lock is
2291 // generally acquired in those two cases.
2292 //
2293 // If the RedefineClasses() API has been used, then this cache can
2294 // grow and we'll have transitions from non-null to bigger non-null.
2295 // Cache creation requires no leaks and we require safety between all
2296 // cache accesses and freeing of the old cache so a lock is generally
2297 // acquired when the RedefineClasses() API has been used.
2298
2299 if (jmeths != nullptr) {
2300 // the cache already exists
2301 if (!idnum_can_increment()) {
2302 // the cache can't grow so we can just get the current values
2303 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2304 } else {
2305 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2306 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2307 }
2308 }
2309 // implied else:
2310 // we need to allocate a cache so default length and id values are good
2311
2312 if (jmeths == nullptr || // no cache yet
2313 length <= idnum || // cache is too short
2314 id == nullptr) { // cache doesn't contain entry
2315
2316 // This function can be called by the VMThread or GC worker threads so we
2317 // have to do all things that might block on a safepoint before grabbing the lock.
2318 // Otherwise, we can deadlock with the VMThread or have a cache
2319 // consistency issue. These vars keep track of what we might have
2320 // to free after the lock is dropped.
2321 jmethodID to_dealloc_id = nullptr;
2322 jmethodID* to_dealloc_jmeths = nullptr;
2323
2324 // may not allocate new_jmeths or use it if we allocate it
2325 jmethodID* new_jmeths = nullptr;
2326 if (length <= idnum) {
2327 // allocate a new cache that might be used
2328 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
2329 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
2330 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
2331 // cache size is stored in element[0], other elements offset by one
2332 new_jmeths[0] = (jmethodID)size;
2333 }
2334
2335 // allocate a new jmethodID that might be used
2336 {
2337 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2338 jmethodID new_id = nullptr;
2339 if (method_h->is_old() && !method_h->is_obsolete()) {
2340 // The method passed in is old (but not obsolete), we need to use the current version
2341 Method* current_method = method_with_idnum((int)idnum);
2342 assert(current_method != nullptr, "old and but not obsolete, so should exist");
2343 new_id = Method::make_jmethod_id(class_loader_data(), current_method);
2344 } else {
2345 // It is the current version of the method or an obsolete method,
2346 // use the version passed in
2347 new_id = Method::make_jmethod_id(class_loader_data(), method_h());
2348 }
2349
2350 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2351 &to_dealloc_id, &to_dealloc_jmeths);
2352 }
2353
2354 // The lock has been dropped so we can free resources.
2355 // Free up either the old cache or the new cache if we allocated one.
2356 if (to_dealloc_jmeths != nullptr) {
2357 FreeHeap(to_dealloc_jmeths);
2358 }
2359 // free up the new ID since it wasn't needed
2360 if (to_dealloc_id != nullptr) {
2361 Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
2362 }
2363 }
2364 return id;
2365 }
2366
2367 // Figure out how many jmethodIDs haven't been allocated, and make
2368 // sure space for them is pre-allocated. This makes getting all
2369 // method ids much, much faster with classes with more than 8
2370 // methods, and has a *substantial* effect on performance with jvmti
2371 // code that loads all jmethodIDs for all classes.
2372 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2373 int new_jmeths = 0;
2374 int length = methods()->length();
2375 for (int index = start_offset; index < length; index++) {
2376 Method* m = methods()->at(index);
2377 jmethodID id = m->find_jmethod_id_or_null();
2378 if (id == nullptr) {
2379 new_jmeths++;
2380 }
2381 }
2382 if (new_jmeths != 0) {
2383 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2384 }
2385 }
2386
2387 // Common code to fetch the jmethodID from the cache or update the
2388 // cache with the new jmethodID. This function should never do anything
2389 // that causes the caller to go to a safepoint or we can deadlock with
2390 // the VMThread or have cache consistency issues.
2391 //
2392 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
2393 size_t idnum, jmethodID new_id,
2394 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
2395 jmethodID** to_dealloc_jmeths_p) {
2396 assert(new_id != nullptr, "sanity check");
2397 assert(to_dealloc_id_p != nullptr, "sanity check");
2398 assert(to_dealloc_jmeths_p != nullptr, "sanity check");
2399 assert(JmethodIdCreation_lock->owned_by_self(), "sanity check");
2400
2401 // reacquire the cache - we are locked, single threaded or at a safepoint
2402 jmethodID* jmeths = methods_jmethod_ids_acquire();
2403 jmethodID id = nullptr;
2404 size_t length = 0;
2405
2406 if (jmeths == nullptr || // no cache yet
2407 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
2408 if (jmeths != nullptr) {
2409 // copy any existing entries from the old cache
2410 for (size_t index = 0; index < length; index++) {
2411 new_jmeths[index+1] = jmeths[index+1];
2412 }
2413 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
2414 }
2415 release_set_methods_jmethod_ids(jmeths = new_jmeths);
2416 } else {
2417 // fetch jmethodID (if any) from the existing cache
2418 id = jmeths[idnum+1];
2419 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
2420 }
2421 if (id == nullptr) {
2422 // No matching jmethodID in the existing cache or we have a new
2423 // cache or we just grew the cache. This cache write is done here
2424 // by the first thread to win the foot race because a jmethodID
2425 // needs to be unique once it is generally available.
2426 id = new_id;
2427
2428 // The jmethodID cache can be read while unlocked so we have to
2429 // make sure the new jmethodID is complete before installing it
2430 // in the cache.
2431 Atomic::release_store(&jmeths[idnum+1], id);
2432 } else {
2433 *to_dealloc_id_p = new_id; // save new id for later delete
2434 }
2435 return id;
2436 }
2437
2438
2439 // Common code to get the jmethodID cache length and the jmethodID
2440 // value at index idnum if there is one.
2441 //
2442 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
2443 size_t idnum, size_t *length_p, jmethodID* id_p) {
2444 assert(cache != nullptr, "sanity check");
2445 assert(length_p != nullptr, "sanity check");
2446 assert(id_p != nullptr, "sanity check");
2447
2448 // cache size is stored in element[0], other elements offset by one
2449 *length_p = (size_t)cache[0];
2450 if (*length_p <= idnum) { // cache is too short
2451 *id_p = nullptr;
2452 } else {
2453 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
2454 }
2455 }
2456
2457
2458 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2459 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2460 size_t idnum = (size_t)method->method_idnum();
2461 jmethodID* jmeths = methods_jmethod_ids_acquire();
2462 size_t length; // length assigned as debugging crumb
2463 jmethodID id = nullptr;
2464 if (jmeths != nullptr && // If there is a cache
2465 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
2466 id = jmeths[idnum+1]; // Look up the id (may be null)
2467 }
2468 return id;
2469 }
2470
2471 inline DependencyContext InstanceKlass::dependencies() {
2472 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2473 return dep_context;
2474 }
2475
2476 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2477 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2478 }
2479
2480 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2481 dependencies().add_dependent_nmethod(nm);
2482 }
2483
2484 void InstanceKlass::clean_dependency_context() {
2485 dependencies().clean_unloading_dependents();
2486 }
2487
2488 #ifndef PRODUCT
2489 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2490 dependencies().print_dependent_nmethods(verbose);
2491 }
2492
2493 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2494 return dependencies().is_dependent_nmethod(nm);
2495 }
2496 #endif //PRODUCT
2497
2498 void InstanceKlass::clean_weak_instanceklass_links() {
2499 clean_implementors_list();
2500 clean_method_data();
2501 }
2502
2503 void InstanceKlass::clean_implementors_list() {
2504 assert(is_loader_alive(), "this klass should be live");
2505 if (is_interface()) {
2506 assert (ClassUnloading, "only called for ClassUnloading");
2507 for (;;) {
2508 // Use load_acquire due to competing with inserts
2509 InstanceKlass* volatile* iklass = adr_implementor();
2510 assert(iklass != nullptr, "Klass must not be null");
2511 InstanceKlass* impl = Atomic::load_acquire(iklass);
2512 if (impl != nullptr && !impl->is_loader_alive()) {
2513 // null this field, might be an unloaded instance klass or null
2514 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2515 // Successfully unlinking implementor.
2516 if (log_is_enabled(Trace, class, unload)) {
2517 ResourceMark rm;
2518 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2519 }
2520 return;
2521 }
2522 } else {
2523 return;
2524 }
2525 }
2526 }
2527 }
2528
2529 void InstanceKlass::clean_method_data() {
2530 for (int m = 0; m < methods()->length(); m++) {
2531 MethodData* mdo = methods()->at(m)->method_data();
2532 if (mdo != nullptr) {
2533 mdo->clean_method_data(/*always_clean*/false);
2534 }
2535 }
2536 }
2537
2538 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2539 Klass::metaspace_pointers_do(it);
2540
2541 if (log_is_enabled(Trace, cds)) {
2542 ResourceMark rm;
2543 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2544 }
2545
2546 it->push(&_annotations);
2547 it->push((Klass**)&_array_klasses);
2548 if (!is_rewritten()) {
2549 it->push(&_constants, MetaspaceClosure::_writable);
2550 } else {
2551 it->push(&_constants);
2552 }
2553 it->push(&_inner_classes);
2554 #if INCLUDE_JVMTI
2555 it->push(&_previous_versions);
2556 #endif
2557 #if INCLUDE_CDS
2558 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2559 // be rewritten during runtime (see Rewriter::rewrite_jsrs()). So setting the _methods to
2560 // be writable. The length check on the _methods is necessary because classes which
2561 // don't have any methods share the Universe::_the_empty_method_array which is in the RO region.
2562 if (_methods != nullptr && _methods->length() > 0 &&
2563 !can_be_verified_at_dumptime() && methods_contain_jsr_bytecode()) {
2564 // To handle jsr bytecode, new Method* maybe stored into _methods
2565 it->push(&_methods, MetaspaceClosure::_writable);
2566 } else {
2567 #endif
2568 it->push(&_methods);
2569 #if INCLUDE_CDS
2570 }
2571 #endif
2572 it->push(&_default_methods);
2573 it->push(&_local_interfaces);
2574 it->push(&_transitive_interfaces);
2575 it->push(&_method_ordering);
2576 if (!is_rewritten()) {
2577 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2578 } else {
2579 it->push(&_default_vtable_indices);
2580 }
2581
2582 it->push(&_fieldinfo_stream);
2583 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2584 it->push(&_fields_status, MetaspaceClosure::_writable);
2585
2586 if (itable_length() > 0) {
2587 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2588 int method_table_offset_in_words = ioe->offset()/wordSize;
2589 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2590
2591 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2592 / itableOffsetEntry::size();
2593
2594 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2595 if (ioe->interface_klass() != nullptr) {
2596 it->push(ioe->interface_klass_addr());
2597 itableMethodEntry* ime = ioe->first_method_entry(this);
2598 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2599 for (int index = 0; index < n; index ++) {
2600 it->push(ime[index].method_addr());
2601 }
2602 }
2603 }
2604 }
2605
2606 it->push(&_nest_members);
2607 it->push(&_permitted_subclasses);
2608 it->push(&_record_components);
2609 }
2610
2611 #if INCLUDE_CDS
2612 void InstanceKlass::remove_unshareable_info() {
2613
2614 if (is_linked()) {
2615 assert(can_be_verified_at_dumptime(), "must be");
2616 // Remember this so we can avoid walking the hierarchy at runtime.
2617 set_verified_at_dump_time();
2618 }
2619
2620 Klass::remove_unshareable_info();
2621
2622 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2623 // Classes are attempted to link during dumping and may fail,
2624 // but these classes are still in the dictionary and class list in CLD.
2625 // If the class has failed verification, there is nothing else to remove.
2626 return;
2627 }
2628
2629 // Reset to the 'allocated' state to prevent any premature accessing to
2630 // a shared class at runtime while the class is still being loaded and
2631 // restored. A class' init_state is set to 'loaded' at runtime when it's
2632 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2633 _init_state = allocated;
2634
2635 { // Otherwise this needs to take out the Compile_lock.
2636 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2637 init_implementor();
2638 }
2639
2640 constants()->remove_unshareable_info();
2641
2642 for (int i = 0; i < methods()->length(); i++) {
2643 Method* m = methods()->at(i);
2644 m->remove_unshareable_info();
2645 }
2646
2647 // do array classes also.
2648 if (array_klasses() != nullptr) {
2649 array_klasses()->remove_unshareable_info();
2650 }
2651
2652 // These are not allocated from metaspace. They are safe to set to null.
2653 _source_debug_extension = nullptr;
2654 _dep_context = nullptr;
2655 _osr_nmethods_head = nullptr;
2656 #if INCLUDE_JVMTI
2657 _breakpoints = nullptr;
2658 _previous_versions = nullptr;
2659 _cached_class_file = nullptr;
2660 _jvmti_cached_class_field_map = nullptr;
2661 #endif
2662
2663 _init_thread = nullptr;
2664 _methods_jmethod_ids = nullptr;
2665 _jni_ids = nullptr;
2666 _oop_map_cache = nullptr;
2667 // clear _nest_host to ensure re-load at runtime
2668 _nest_host = nullptr;
2669 init_shared_package_entry();
2670 _dep_context_last_cleaned = 0;
2671 _init_monitor = nullptr;
2672
2673 remove_unshareable_flags();
2674 }
2675
2676 void InstanceKlass::remove_unshareable_flags() {
2677 // clear all the flags/stats that shouldn't be in the archived version
2678 assert(!is_scratch_class(), "must be");
2679 assert(!has_been_redefined(), "must be");
2680 #if INCLUDE_JVMTI
2681 set_is_being_redefined(false);
2682 #endif
2683 set_has_resolved_methods(false);
2684 }
2685
2686 void InstanceKlass::remove_java_mirror() {
2687 Klass::remove_java_mirror();
2688
2689 // do array classes also.
2690 if (array_klasses() != nullptr) {
2691 array_klasses()->remove_java_mirror();
2692 }
2693 }
2694
2695 void InstanceKlass::init_shared_package_entry() {
2696 assert(CDSConfig::is_dumping_archive(), "must be");
2697 #if !INCLUDE_CDS_JAVA_HEAP
2698 _package_entry = nullptr;
2699 #else
2700 if (CDSConfig::is_dumping_full_module_graph()) {
2701 if (is_shared_unregistered_class()) {
2702 _package_entry = nullptr;
2703 } else {
2704 _package_entry = PackageEntry::get_archived_entry(_package_entry);
2705 }
2706 } else if (CDSConfig::is_dumping_dynamic_archive() &&
2707 CDSConfig::is_using_full_module_graph() &&
2708 MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
2709 // _package_entry is an archived package in the base archive. Leave it as is.
2710 } else {
2711 _package_entry = nullptr;
2712 }
2713 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2714 #endif
2715 }
2716
2717 void InstanceKlass::compute_has_loops_flag_for_methods() {
2718 Array<Method*>* methods = this->methods();
2719 for (int index = 0; index < methods->length(); ++index) {
2720 Method* m = methods->at(index);
2721 if (!m->is_overpass()) { // work around JDK-8305771
2722 m->compute_has_loops_flag();
2723 }
2724 }
2725 }
2726
2727 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2728 PackageEntry* pkg_entry, TRAPS) {
2729 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2730 // before the InstanceKlass is added to the SystemDictionary. Make
2731 // sure the current state is <loaded.
2732 assert(!is_loaded(), "invalid init state");
2733 assert(!shared_loading_failed(), "Must not try to load failed class again");
2734 set_package(loader_data, pkg_entry, CHECK);
2735 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2736
2737 Array<Method*>* methods = this->methods();
2738 int num_methods = methods->length();
2739 for (int index = 0; index < num_methods; ++index) {
2740 methods->at(index)->restore_unshareable_info(CHECK);
2741 }
2742 #if INCLUDE_JVMTI
2743 if (JvmtiExport::has_redefined_a_class()) {
2744 // Reinitialize vtable because RedefineClasses may have changed some
2745 // entries in this vtable for super classes so the CDS vtable might
2746 // point to old or obsolete entries. RedefineClasses doesn't fix up
2747 // vtables in the shared system dictionary, only the main one.
2748 // It also redefines the itable too so fix that too.
2749 // First fix any default methods that point to a super class that may
2750 // have been redefined.
2751 bool trace_name_printed = false;
2752 adjust_default_methods(&trace_name_printed);
2753 vtable().initialize_vtable();
2754 itable().initialize_itable();
2755 }
2756 #endif
2757
2758 // restore constant pool resolved references
2759 constants()->restore_unshareable_info(CHECK);
2760
2761 if (array_klasses() != nullptr) {
2762 // To get a consistent list of classes we need MultiArray_lock to ensure
2763 // array classes aren't observed while they are being restored.
2764 RecursiveLocker rl(MultiArray_lock, THREAD);
2765 assert(this == array_klasses()->bottom_klass(), "sanity");
2766 // Array classes have null protection domain.
2767 // --> see ArrayKlass::complete_create_array_klass()
2768 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2769 }
2770
2771 // Initialize @ValueBased class annotation
2772 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation()) {
2773 set_is_value_based();
2774 }
2775
2776 // restore the monitor
2777 _init_monitor = create_init_monitor("InstanceKlassInitMonitorRestored_lock");
2778 }
2779
2780 // Check if a class or any of its supertypes has a version older than 50.
2781 // CDS will not perform verification of old classes during dump time because
2782 // without changing the old verifier, the verification constraint cannot be
2783 // retrieved during dump time.
2784 // Verification of archived old classes will be performed during run time.
2785 bool InstanceKlass::can_be_verified_at_dumptime() const {
2786 if (MetaspaceShared::is_in_shared_metaspace(this)) {
2787 // This is a class that was dumped into the base archive, so we know
2788 // it was verified at dump time.
2789 return true;
2790 }
2791 if (major_version() < 50 /*JAVA_6_VERSION*/) {
2792 return false;
2793 }
2794 if (java_super() != nullptr && !java_super()->can_be_verified_at_dumptime()) {
2795 return false;
2796 }
2797 Array<InstanceKlass*>* interfaces = local_interfaces();
2798 int len = interfaces->length();
2799 for (int i = 0; i < len; i++) {
2800 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2801 return false;
2802 }
2803 }
2804 return true;
2805 }
2806
2807 bool InstanceKlass::methods_contain_jsr_bytecode() const {
2808 Thread* thread = Thread::current();
2809 for (int i = 0; i < _methods->length(); i++) {
2810 methodHandle m(thread, _methods->at(i));
2811 BytecodeStream bcs(m);
2812 while (!bcs.is_last_bytecode()) {
2813 Bytecodes::Code opcode = bcs.next();
2814 if (opcode == Bytecodes::_jsr || opcode == Bytecodes::_jsr_w) {
2815 return true;
2816 }
2817 }
2818 }
2819 return false;
2820 }
2821 #endif // INCLUDE_CDS
2822
2823 #if INCLUDE_JVMTI
2824 static void clear_all_breakpoints(Method* m) {
2825 m->clear_all_breakpoints();
2826 }
2827 #endif
2828
2829 void InstanceKlass::unload_class(InstanceKlass* ik) {
2830 // Release dependencies.
2831 ik->dependencies().remove_all_dependents();
2832
2833 // notify the debugger
2834 if (JvmtiExport::should_post_class_unload()) {
2835 JvmtiExport::post_class_unload(ik);
2836 }
2837
2838 // notify ClassLoadingService of class unload
2839 ClassLoadingService::notify_class_unloaded(ik);
2840
2841 SystemDictionaryShared::handle_class_unloading(ik);
2842
2843 if (log_is_enabled(Info, class, unload)) {
2844 ResourceMark rm;
2845 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2846 }
2847
2848 Events::log_class_unloading(Thread::current(), ik);
2849
2850 #if INCLUDE_JFR
2851 assert(ik != nullptr, "invariant");
2852 EventClassUnload event;
2853 event.set_unloadedClass(ik);
2854 event.set_definingClassLoader(ik->class_loader_data());
2855 event.commit();
2856 #endif
2857 }
2858
2859 static void method_release_C_heap_structures(Method* m) {
2860 m->release_C_heap_structures();
2861 }
2862
2863 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2864 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2865 // Clean up C heap
2866 Klass::release_C_heap_structures();
2867
2868 // Deallocate and call destructors for MDO mutexes
2869 if (release_sub_metadata) {
2870 methods_do(method_release_C_heap_structures);
2871 }
2872
2873 // Destroy the init_monitor
2874 delete _init_monitor;
2875
2876 // Deallocate oop map cache
2877 if (_oop_map_cache != nullptr) {
2878 delete _oop_map_cache;
2879 _oop_map_cache = nullptr;
2880 }
2881
2882 // Deallocate JNI identifiers for jfieldIDs
2883 JNIid::deallocate(jni_ids());
2884 set_jni_ids(nullptr);
2885
2886 jmethodID* jmeths = methods_jmethod_ids_acquire();
2887 if (jmeths != (jmethodID*)nullptr) {
2888 release_set_methods_jmethod_ids(nullptr);
2889 FreeHeap(jmeths);
2890 }
2891
2892 assert(_dep_context == nullptr,
2893 "dependencies should already be cleaned");
2894
2895 #if INCLUDE_JVMTI
2896 // Deallocate breakpoint records
2897 if (breakpoints() != 0x0) {
2898 methods_do(clear_all_breakpoints);
2899 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2900 }
2901
2902 // deallocate the cached class file
2903 if (_cached_class_file != nullptr) {
2904 os::free(_cached_class_file);
2905 _cached_class_file = nullptr;
2906 }
2907 #endif
2908
2909 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2910
2911 if (release_sub_metadata) {
2912 constants()->release_C_heap_structures();
2913 }
2914 }
2915
2916 // The constant pool is on stack if any of the methods are executing or
2917 // referenced by handles.
2918 bool InstanceKlass::on_stack() const {
2919 return _constants->on_stack();
2920 }
2921
2922 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
2923 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
2924 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
2925
2926 // minor and major version numbers of class file
2927 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
2928 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
2929 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
2930 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
2931
2932 InstanceKlass* InstanceKlass::get_klass_version(int version) {
2933 for (InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
2934 if (ik->constants()->version() == version) {
2935 return ik;
2936 }
2937 }
2938 return nullptr;
2939 }
2940
2941 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2942 if (array == nullptr) {
2943 _source_debug_extension = nullptr;
2944 } else {
2945 // Adding one to the attribute length in order to store a null terminator
2946 // character could cause an overflow because the attribute length is
2947 // already coded with an u4 in the classfile, but in practice, it's
2948 // unlikely to happen.
2949 assert((length+1) > length, "Overflow checking");
2950 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2951 for (int i = 0; i < length; i++) {
2952 sde[i] = array[i];
2953 }
2954 sde[length] = '\0';
2955 _source_debug_extension = sde;
2956 }
2957 }
2958
2959 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
2960 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
2961 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
2962
2963 const char* InstanceKlass::signature_name() const {
2964
2965 // Get the internal name as a c string
2966 const char* src = (const char*) (name()->as_C_string());
2967 const int src_length = (int)strlen(src);
2968
2969 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
2970
2971 // Add L as type indicator
2972 int dest_index = 0;
2973 dest[dest_index++] = JVM_SIGNATURE_CLASS;
2974
2975 // Add the actual class name
2976 for (int src_index = 0; src_index < src_length; ) {
2977 dest[dest_index++] = src[src_index++];
2978 }
2979
2980 if (is_hidden()) { // Replace the last '+' with a '.'.
2981 for (int index = (int)src_length; index > 0; index--) {
2982 if (dest[index] == '+') {
2983 dest[index] = JVM_SIGNATURE_DOT;
2984 break;
2985 }
2986 }
2987 }
2988
2989 // Add the semicolon and the null
2990 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
2991 dest[dest_index] = '\0';
2992 return dest;
2993 }
2994
2995 ModuleEntry* InstanceKlass::module() const {
2996 if (is_hidden() &&
2997 in_unnamed_package() &&
2998 class_loader_data()->has_class_mirror_holder()) {
2999 // For a non-strong hidden class defined to an unnamed package,
3000 // its (class held) CLD will not have an unnamed module created for it.
3001 // Two choices to find the correct ModuleEntry:
3002 // 1. If hidden class is within a nest, use nest host's module
3003 // 2. Find the unnamed module off from the class loader
3004 // For now option #2 is used since a nest host is not set until
3005 // after the instance class is created in jvm_lookup_define_class().
3006 if (class_loader_data()->is_boot_class_loader_data()) {
3007 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3008 } else {
3009 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3010 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3011 return java_lang_Module::module_entry(module);
3012 }
3013 }
3014
3015 // Class is in a named package
3016 if (!in_unnamed_package()) {
3017 return _package_entry->module();
3018 }
3019
3020 // Class is in an unnamed package, return its loader's unnamed module
3021 return class_loader_data()->unnamed_module();
3022 }
3023
3024 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3025
3026 // ensure java/ packages only loaded by boot or platform builtin loaders
3027 // not needed for shared class since CDS does not archive prohibited classes.
3028 if (!is_shared()) {
3029 check_prohibited_package(name(), loader_data, CHECK);
3030 }
3031
3032 if (is_shared() && _package_entry != nullptr) {
3033 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3034 // we can use the saved package
3035 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
3036 return;
3037 } else {
3038 _package_entry = nullptr;
3039 }
3040 }
3041
3042 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3043 // it returns, so we need to decrement it when the current function exits.
3044 TempNewSymbol from_class_name =
3045 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3046
3047 Symbol* pkg_name;
3048 if (pkg_entry != nullptr) {
3049 pkg_name = pkg_entry->name();
3050 } else {
3051 pkg_name = from_class_name;
3052 }
3053
3054 if (pkg_name != nullptr && loader_data != nullptr) {
3055
3056 // Find in class loader's package entry table.
3057 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3058
3059 // If the package name is not found in the loader's package
3060 // entry table, it is an indication that the package has not
3061 // been defined. Consider it defined within the unnamed module.
3062 if (_package_entry == nullptr) {
3063
3064 if (!ModuleEntryTable::javabase_defined()) {
3065 // Before java.base is defined during bootstrapping, define all packages in
3066 // the java.base module. If a non-java.base package is erroneously placed
3067 // in the java.base module it will be caught later when java.base
3068 // is defined by ModuleEntryTable::verify_javabase_packages check.
3069 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3070 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3071 } else {
3072 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3073 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3074 }
3075
3076 // A package should have been successfully created
3077 DEBUG_ONLY(ResourceMark rm(THREAD));
3078 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3079 name()->as_C_string(), loader_data->loader_name_and_id());
3080 }
3081
3082 if (log_is_enabled(Debug, module)) {
3083 ResourceMark rm(THREAD);
3084 ModuleEntry* m = _package_entry->module();
3085 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3086 external_name(),
3087 pkg_name->as_C_string(),
3088 loader_data->loader_name_and_id(),
3089 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3090 }
3091 } else {
3092 ResourceMark rm(THREAD);
3093 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3094 external_name(),
3095 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3096 UNNAMED_MODULE);
3097 }
3098 }
3099
3100 // Function set_classpath_index ensures that for a non-null _package_entry
3101 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3102 // It then sets the classpath_index in the package entry record.
3103 //
3104 // The classpath_index field is used to find the entry on the boot loader class
3105 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3106 // in an unnamed module. It is also used to indicate (for all packages whose
3107 // classes are loaded by the boot loader) that at least one of the package's
3108 // classes has been loaded.
3109 void InstanceKlass::set_classpath_index(s2 path_index) {
3110 if (_package_entry != nullptr) {
3111 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3112 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3113 assert(path_index != -1, "Unexpected classpath_index");
3114 _package_entry->set_classpath_index(path_index);
3115 }
3116 }
3117
3118 // different versions of is_same_class_package
3119
3120 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3121 oop classloader1 = this->class_loader();
3122 PackageEntry* classpkg1 = this->package();
3123 if (class2->is_objArray_klass()) {
3124 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3125 }
3126
3127 oop classloader2;
3128 PackageEntry* classpkg2;
3129 if (class2->is_instance_klass()) {
3130 classloader2 = class2->class_loader();
3131 classpkg2 = class2->package();
3132 } else {
3133 assert(class2->is_typeArray_klass(), "should be type array");
3134 classloader2 = nullptr;
3135 classpkg2 = nullptr;
3136 }
3137
3138 // Same package is determined by comparing class loader
3139 // and package entries. Both must be the same. This rule
3140 // applies even to classes that are defined in the unnamed
3141 // package, they still must have the same class loader.
3142 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3143 return true;
3144 }
3145
3146 return false;
3147 }
3148
3149 // return true if this class and other_class are in the same package. Classloader
3150 // and classname information is enough to determine a class's package
3151 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3152 const Symbol* other_class_name) const {
3153 if (class_loader() != other_class_loader) {
3154 return false;
3155 }
3156 if (name()->fast_compare(other_class_name) == 0) {
3157 return true;
3158 }
3159
3160 {
3161 ResourceMark rm;
3162
3163 bool bad_class_name = false;
3164 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3165 if (bad_class_name) {
3166 return false;
3167 }
3168 // Check that package_from_class_name() returns null, not "", if there is no package.
3169 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3170
3171 const Symbol* const this_package_name =
3172 this->package() != nullptr ? this->package()->name() : nullptr;
3173
3174 if (this_package_name == nullptr || other_pkg == nullptr) {
3175 // One of the two doesn't have a package. Only return true if the other
3176 // one also doesn't have a package.
3177 return this_package_name == other_pkg;
3178 }
3179
3180 // Check if package is identical
3181 return this_package_name->fast_compare(other_pkg) == 0;
3182 }
3183 }
3184
3185 static bool is_prohibited_package_slow(Symbol* class_name) {
3186 // Caller has ResourceMark
3187 int length;
3188 jchar* unicode = class_name->as_unicode(length);
3189 return (length >= 5 &&
3190 unicode[0] == 'j' &&
3191 unicode[1] == 'a' &&
3192 unicode[2] == 'v' &&
3193 unicode[3] == 'a' &&
3194 unicode[4] == '/');
3195 }
3196
3197 // Only boot and platform class loaders can define classes in "java/" packages.
3198 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3199 ClassLoaderData* loader_data,
3200 TRAPS) {
3201 if (!loader_data->is_boot_class_loader_data() &&
3202 !loader_data->is_platform_class_loader_data() &&
3203 class_name != nullptr && class_name->utf8_length() >= 5) {
3204 ResourceMark rm(THREAD);
3205 bool prohibited;
3206 const u1* base = class_name->base();
3207 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3208 prohibited = is_prohibited_package_slow(class_name);
3209 } else {
3210 char* name = class_name->as_C_string();
3211 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3212 }
3213 if (prohibited) {
3214 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3215 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3216 char* name = pkg_name->as_C_string();
3217 const char* class_loader_name = loader_data->loader_name_and_id();
3218 StringUtils::replace_no_expand(name, "/", ".");
3219 const char* msg_text1 = "Class loader (instance of): ";
3220 const char* msg_text2 = " tried to load prohibited package name: ";
3221 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3222 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3223 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3224 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3225 }
3226 }
3227 return;
3228 }
3229
3230 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3231 constantPoolHandle i_cp(THREAD, constants());
3232 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3233 int ioff = iter.inner_class_info_index();
3234 if (ioff != 0) {
3235 // Check to see if the name matches the class we're looking for
3236 // before attempting to find the class.
3237 if (i_cp->klass_name_at_matches(this, ioff)) {
3238 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3239 if (this == inner_klass) {
3240 *ooff = iter.outer_class_info_index();
3241 *noff = iter.inner_name_index();
3242 return true;
3243 }
3244 }
3245 }
3246 }
3247 return false;
3248 }
3249
3250 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3251 InstanceKlass* outer_klass = nullptr;
3252 *inner_is_member = false;
3253 int ooff = 0, noff = 0;
3254 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3255 if (has_inner_classes_attr) {
3256 constantPoolHandle i_cp(THREAD, constants());
3257 if (ooff != 0) {
3258 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3259 if (!ok->is_instance_klass()) {
3260 // If the outer class is not an instance klass then it cannot have
3261 // declared any inner classes.
3262 ResourceMark rm(THREAD);
3263 Exceptions::fthrow(
3264 THREAD_AND_LOCATION,
3265 vmSymbols::java_lang_IncompatibleClassChangeError(),
3266 "%s and %s disagree on InnerClasses attribute",
3267 ok->external_name(),
3268 external_name());
3269 return nullptr;
3270 }
3271 outer_klass = InstanceKlass::cast(ok);
3272 *inner_is_member = true;
3273 }
3274 if (nullptr == outer_klass) {
3275 // It may be a local class; try for that.
3276 int encl_method_class_idx = enclosing_method_class_index();
3277 if (encl_method_class_idx != 0) {
3278 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3279 outer_klass = InstanceKlass::cast(ok);
3280 *inner_is_member = false;
3281 }
3282 }
3283 }
3284
3285 // If no inner class attribute found for this class.
3286 if (nullptr == outer_klass) return nullptr;
3287
3288 // Throws an exception if outer klass has not declared k as an inner klass
3289 // We need evidence that each klass knows about the other, or else
3290 // the system could allow a spoof of an inner class to gain access rights.
3291 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3292 return outer_klass;
3293 }
3294
3295 jint InstanceKlass::compute_modifier_flags() const {
3296 jint access = access_flags().as_int();
3297
3298 // But check if it happens to be member class.
3299 InnerClassesIterator iter(this);
3300 for (; !iter.done(); iter.next()) {
3301 int ioff = iter.inner_class_info_index();
3302 // Inner class attribute can be zero, skip it.
3303 // Strange but true: JVM spec. allows null inner class refs.
3304 if (ioff == 0) continue;
3305
3306 // only look at classes that are already loaded
3307 // since we are looking for the flags for our self.
3308 Symbol* inner_name = constants()->klass_name_at(ioff);
3309 if (name() == inner_name) {
3310 // This is really a member class.
3311 access = iter.inner_access_flags();
3312 break;
3313 }
3314 }
3315 // Remember to strip ACC_SUPER bit
3316 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
3317 }
3318
3319 jint InstanceKlass::jvmti_class_status() const {
3320 jint result = 0;
3321
3322 if (is_linked()) {
3323 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3324 }
3325
3326 if (is_initialized()) {
3327 assert(is_linked(), "Class status is not consistent");
3328 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3329 }
3330 if (is_in_error_state()) {
3331 result |= JVMTI_CLASS_STATUS_ERROR;
3332 }
3333 return result;
3334 }
3335
3336 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3337 bool implements_interface; // initialized by method_at_itable_or_null
3338 Method* m = method_at_itable_or_null(holder, index,
3339 implements_interface); // out parameter
3340 if (m != nullptr) {
3341 assert(implements_interface, "sanity");
3342 return m;
3343 } else if (implements_interface) {
3344 // Throw AbstractMethodError since corresponding itable slot is empty.
3345 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3346 } else {
3347 // If the interface isn't implemented by the receiver class,
3348 // the VM should throw IncompatibleClassChangeError.
3349 ResourceMark rm(THREAD);
3350 stringStream ss;
3351 bool same_module = (module() == holder->module());
3352 ss.print("Receiver class %s does not implement "
3353 "the interface %s defining the method to be called "
3354 "(%s%s%s)",
3355 external_name(), holder->external_name(),
3356 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3357 (same_module) ? "" : "; ",
3358 (same_module) ? "" : holder->class_in_module_of_loader());
3359 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3360 }
3361 }
3362
3363 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3364 klassItable itable(this);
3365 for (int i = 0; i < itable.size_offset_table(); i++) {
3366 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3367 if (offset_entry->interface_klass() == holder) {
3368 implements_interface = true;
3369 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3370 Method* m = ime[index].method();
3371 return m;
3372 }
3373 }
3374 implements_interface = false;
3375 return nullptr; // offset entry not found
3376 }
3377
3378 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3379 assert(is_linked(), "required");
3380 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3381 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3382
3383 int vtable_index = Method::invalid_vtable_index;
3384 Symbol* name = intf_method->name();
3385 Symbol* signature = intf_method->signature();
3386
3387 // First check in default method array
3388 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3389 int index = find_method_index(default_methods(),
3390 name, signature,
3391 Klass::OverpassLookupMode::find,
3392 Klass::StaticLookupMode::find,
3393 Klass::PrivateLookupMode::find);
3394 if (index >= 0) {
3395 vtable_index = default_vtable_indices()->at(index);
3396 }
3397 }
3398 if (vtable_index == Method::invalid_vtable_index) {
3399 // get vtable_index for miranda methods
3400 klassVtable vt = vtable();
3401 vtable_index = vt.index_of_miranda(name, signature);
3402 }
3403 return vtable_index;
3404 }
3405
3406 #if INCLUDE_JVMTI
3407 // update default_methods for redefineclasses for methods that are
3408 // not yet in the vtable due to concurrent subclass define and superinterface
3409 // redefinition
3410 // Note: those in the vtable, should have been updated via adjust_method_entries
3411 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3412 // search the default_methods for uses of either obsolete or EMCP methods
3413 if (default_methods() != nullptr) {
3414 for (int index = 0; index < default_methods()->length(); index ++) {
3415 Method* old_method = default_methods()->at(index);
3416 if (old_method == nullptr || !old_method->is_old()) {
3417 continue; // skip uninteresting entries
3418 }
3419 assert(!old_method->is_deleted(), "default methods may not be deleted");
3420 Method* new_method = old_method->get_new_method();
3421 default_methods()->at_put(index, new_method);
3422
3423 if (log_is_enabled(Info, redefine, class, update)) {
3424 ResourceMark rm;
3425 if (!(*trace_name_printed)) {
3426 log_info(redefine, class, update)
3427 ("adjust: klassname=%s default methods from name=%s",
3428 external_name(), old_method->method_holder()->external_name());
3429 *trace_name_printed = true;
3430 }
3431 log_debug(redefine, class, update, vtables)
3432 ("default method update: %s(%s) ",
3433 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3434 }
3435 }
3436 }
3437 }
3438 #endif // INCLUDE_JVMTI
3439
3440 // On-stack replacement stuff
3441 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3442 assert_lock_strong(CompiledMethod_lock);
3443 #ifndef PRODUCT
3444 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3445 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3446 "redundant OSR recompilation detected. memory leak in CodeCache!");
3447 #endif
3448 // only one compilation can be active
3449 assert(n->is_osr_method(), "wrong kind of nmethod");
3450 n->set_osr_link(osr_nmethods_head());
3451 set_osr_nmethods_head(n);
3452 // Raise the highest osr level if necessary
3453 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3454
3455 // Get rid of the osr methods for the same bci that have lower levels.
3456 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3457 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3458 if (inv != nullptr && inv->is_in_use()) {
3459 inv->make_not_entrant();
3460 }
3461 }
3462 }
3463
3464 // Remove osr nmethod from the list. Return true if found and removed.
3465 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3466 // This is a short non-blocking critical region, so the no safepoint check is ok.
3467 ConditionalMutexLocker ml(CompiledMethod_lock, !CompiledMethod_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3468 assert(n->is_osr_method(), "wrong kind of nmethod");
3469 nmethod* last = nullptr;
3470 nmethod* cur = osr_nmethods_head();
3471 int max_level = CompLevel_none; // Find the max comp level excluding n
3472 Method* m = n->method();
3473 // Search for match
3474 bool found = false;
3475 while(cur != nullptr && cur != n) {
3476 if (m == cur->method()) {
3477 // Find max level before n
3478 max_level = MAX2(max_level, cur->comp_level());
3479 }
3480 last = cur;
3481 cur = cur->osr_link();
3482 }
3483 nmethod* next = nullptr;
3484 if (cur == n) {
3485 found = true;
3486 next = cur->osr_link();
3487 if (last == nullptr) {
3488 // Remove first element
3489 set_osr_nmethods_head(next);
3490 } else {
3491 last->set_osr_link(next);
3492 }
3493 }
3494 n->set_osr_link(nullptr);
3495 cur = next;
3496 while (cur != nullptr) {
3497 // Find max level after n
3498 if (m == cur->method()) {
3499 max_level = MAX2(max_level, cur->comp_level());
3500 }
3501 cur = cur->osr_link();
3502 }
3503 m->set_highest_osr_comp_level(max_level);
3504 return found;
3505 }
3506
3507 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3508 ConditionalMutexLocker ml(CompiledMethod_lock, !CompiledMethod_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3509 nmethod* osr = osr_nmethods_head();
3510 int found = 0;
3511 while (osr != nullptr) {
3512 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3513 if (osr->method() == m) {
3514 deopt_scope->mark(osr);
3515 found++;
3516 }
3517 osr = osr->osr_link();
3518 }
3519 return found;
3520 }
3521
3522 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3523 ConditionalMutexLocker ml(CompiledMethod_lock, !CompiledMethod_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3524 nmethod* osr = osr_nmethods_head();
3525 nmethod* best = nullptr;
3526 while (osr != nullptr) {
3527 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3528 // There can be a time when a c1 osr method exists but we are waiting
3529 // for a c2 version. When c2 completes its osr nmethod we will trash
3530 // the c1 version and only be able to find the c2 version. However
3531 // while we overflow in the c1 code at back branches we don't want to
3532 // try and switch to the same code as we are already running
3533
3534 if (osr->method() == m &&
3535 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3536 if (match_level) {
3537 if (osr->comp_level() == comp_level) {
3538 // Found a match - return it.
3539 return osr;
3540 }
3541 } else {
3542 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3543 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3544 // Found the best possible - return it.
3545 return osr;
3546 }
3547 best = osr;
3548 }
3549 }
3550 }
3551 osr = osr->osr_link();
3552 }
3553
3554 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3555 if (best != nullptr && best->comp_level() >= comp_level) {
3556 return best;
3557 }
3558 return nullptr;
3559 }
3560
3561 // -----------------------------------------------------------------------------------------------------
3562 // Printing
3563
3564 #define BULLET " - "
3565
3566 static const char* state_names[] = {
3567 "allocated", "loaded", "being_linked", "linked", "being_initialized", "fully_initialized", "initialization_error"
3568 };
3569
3570 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3571 for (int i = 0; i < len; i++) {
3572 intptr_t e = start[i];
3573 st->print("%d : " INTPTR_FORMAT, i, e);
3574 if (MetaspaceObj::is_valid((Metadata*)e)) {
3575 st->print(" ");
3576 ((Metadata*)e)->print_value_on(st);
3577 }
3578 st->cr();
3579 }
3580 }
3581
3582 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3583 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3584 }
3585
3586 const char* InstanceKlass::init_state_name() const {
3587 return state_names[init_state()];
3588 }
3589
3590 void InstanceKlass::print_on(outputStream* st) const {
3591 assert(is_klass(), "must be klass");
3592 Klass::print_on(st);
3593
3594 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3595 st->print(BULLET"klass size: %d", size()); st->cr();
3596 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3597 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
3598 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
3599 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3600 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3601 st->print(BULLET"sub: ");
3602 Klass* sub = subklass();
3603 int n;
3604 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3605 if (n < MaxSubklassPrintSize) {
3606 sub->print_value_on(st);
3607 st->print(" ");
3608 }
3609 }
3610 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3611 st->cr();
3612
3613 if (is_interface()) {
3614 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3615 if (nof_implementors() == 1) {
3616 st->print_cr(BULLET"implementor: ");
3617 st->print(" ");
3618 implementor()->print_value_on(st);
3619 st->cr();
3620 }
3621 }
3622
3623 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3624 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3625 if (Verbose || WizardMode) {
3626 Array<Method*>* method_array = methods();
3627 for (int i = 0; i < method_array->length(); i++) {
3628 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3629 }
3630 }
3631 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3632 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3633 if (Verbose && default_methods() != nullptr) {
3634 Array<Method*>* method_array = default_methods();
3635 for (int i = 0; i < method_array->length(); i++) {
3636 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3637 }
3638 }
3639 if (default_vtable_indices() != nullptr) {
3640 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
3641 }
3642 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3643 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3644 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3645 if (class_loader_data() != nullptr) {
3646 st->print(BULLET"class loader data: ");
3647 class_loader_data()->print_value_on(st);
3648 st->cr();
3649 }
3650 if (source_file_name() != nullptr) {
3651 st->print(BULLET"source file: ");
3652 source_file_name()->print_value_on(st);
3653 st->cr();
3654 }
3655 if (source_debug_extension() != nullptr) {
3656 st->print(BULLET"source debug extension: ");
3657 st->print("%s", source_debug_extension());
3658 st->cr();
3659 }
3660 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
3661 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
3662 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
3663 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
3664 {
3665 bool have_pv = false;
3666 // previous versions are linked together through the InstanceKlass
3667 for (InstanceKlass* pv_node = previous_versions();
3668 pv_node != nullptr;
3669 pv_node = pv_node->previous_versions()) {
3670 if (!have_pv)
3671 st->print(BULLET"previous version: ");
3672 have_pv = true;
3673 pv_node->constants()->print_value_on(st);
3674 }
3675 if (have_pv) st->cr();
3676 }
3677
3678 if (generic_signature() != nullptr) {
3679 st->print(BULLET"generic signature: ");
3680 generic_signature()->print_value_on(st);
3681 st->cr();
3682 }
3683 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3684 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3685 if (record_components() != nullptr) {
3686 st->print(BULLET"record components: "); record_components()->print_value_on(st); st->cr();
3687 }
3688 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
3689 if (java_mirror() != nullptr) {
3690 st->print(BULLET"java mirror: ");
3691 java_mirror()->print_value_on(st);
3692 st->cr();
3693 } else {
3694 st->print_cr(BULLET"java mirror: null");
3695 }
3696 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3697 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3698 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3699 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3700 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3701 FieldPrinter print_static_field(st);
3702 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3703 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3704 FieldPrinter print_nonstatic_field(st);
3705 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3706 ik->print_nonstatic_fields(&print_nonstatic_field);
3707
3708 st->print(BULLET"non-static oop maps: ");
3709 OopMapBlock* map = start_of_nonstatic_oop_maps();
3710 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3711 while (map < end_map) {
3712 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3713 map++;
3714 }
3715 st->cr();
3716 }
3717
3718 void InstanceKlass::print_value_on(outputStream* st) const {
3719 assert(is_klass(), "must be klass");
3720 if (Verbose || WizardMode) access_flags().print_on(st);
3721 name()->print_value_on(st);
3722 }
3723
3724 void FieldPrinter::do_field(fieldDescriptor* fd) {
3725 _st->print(BULLET);
3726 if (_obj == nullptr) {
3727 fd->print_on(_st);
3728 _st->cr();
3729 } else {
3730 fd->print_on_for(_st, _obj);
3731 _st->cr();
3732 }
3733 }
3734
3735
3736 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3737 Klass::oop_print_on(obj, st);
3738
3739 if (this == vmClasses::String_klass()) {
3740 typeArrayOop value = java_lang_String::value(obj);
3741 juint length = java_lang_String::length(obj);
3742 if (value != nullptr &&
3743 value->is_typeArray() &&
3744 length <= (juint) value->length()) {
3745 st->print(BULLET"string: ");
3746 java_lang_String::print(obj, st);
3747 st->cr();
3748 }
3749 }
3750
3751 st->print_cr(BULLET"---- fields (total size " SIZE_FORMAT " words):", oop_size(obj));
3752 FieldPrinter print_field(st, obj);
3753 print_nonstatic_fields(&print_field);
3754
3755 if (this == vmClasses::Class_klass()) {
3756 st->print(BULLET"signature: ");
3757 java_lang_Class::print_signature(obj, st);
3758 st->cr();
3759 Klass* real_klass = java_lang_Class::as_Klass(obj);
3760 if (real_klass != nullptr && real_klass->is_instance_klass()) {
3761 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3762 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3763 }
3764 } else if (this == vmClasses::MethodType_klass()) {
3765 st->print(BULLET"signature: ");
3766 java_lang_invoke_MethodType::print_signature(obj, st);
3767 st->cr();
3768 }
3769 }
3770
3771 #ifndef PRODUCT
3772
3773 bool InstanceKlass::verify_itable_index(int i) {
3774 int method_count = klassItable::method_count_for_interface(this);
3775 assert(i >= 0 && i < method_count, "index out of bounds");
3776 return true;
3777 }
3778
3779 #endif //PRODUCT
3780
3781 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3782 st->print("a ");
3783 name()->print_value_on(st);
3784 obj->print_address_on(st);
3785 if (this == vmClasses::String_klass()
3786 && java_lang_String::value(obj) != nullptr) {
3787 ResourceMark rm;
3788 int len = java_lang_String::length(obj);
3789 int plen = (len < 24 ? len : 12);
3790 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3791 st->print(" = \"%s\"", str);
3792 if (len > plen)
3793 st->print("...[%d]", len);
3794 } else if (this == vmClasses::Class_klass()) {
3795 Klass* k = java_lang_Class::as_Klass(obj);
3796 st->print(" = ");
3797 if (k != nullptr) {
3798 k->print_value_on(st);
3799 } else {
3800 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3801 st->print("%s", tname ? tname : "type?");
3802 }
3803 } else if (this == vmClasses::MethodType_klass()) {
3804 st->print(" = ");
3805 java_lang_invoke_MethodType::print_signature(obj, st);
3806 } else if (java_lang_boxing_object::is_instance(obj)) {
3807 st->print(" = ");
3808 java_lang_boxing_object::print(obj, st);
3809 } else if (this == vmClasses::LambdaForm_klass()) {
3810 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3811 if (vmentry != nullptr) {
3812 st->print(" => ");
3813 vmentry->print_value_on(st);
3814 }
3815 } else if (this == vmClasses::MemberName_klass()) {
3816 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3817 if (vmtarget != nullptr) {
3818 st->print(" = ");
3819 vmtarget->print_value_on(st);
3820 } else {
3821 oop clazz = java_lang_invoke_MemberName::clazz(obj);
3822 oop name = java_lang_invoke_MemberName::name(obj);
3823 if (clazz != nullptr) {
3824 clazz->print_value_on(st);
3825 } else {
3826 st->print("null");
3827 }
3828 st->print(".");
3829 if (name != nullptr) {
3830 name->print_value_on(st);
3831 } else {
3832 st->print("null");
3833 }
3834 }
3835 }
3836 }
3837
3838 const char* InstanceKlass::internal_name() const {
3839 return external_name();
3840 }
3841
3842 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3843 const ModuleEntry* module_entry,
3844 const ClassFileStream* cfs) const {
3845
3846 if (ClassListWriter::is_enabled()) {
3847 ClassListWriter::write(this, cfs);
3848 }
3849
3850 print_class_load_helper(loader_data, module_entry, cfs);
3851 print_class_load_cause_logging();
3852 }
3853
3854 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3855 const ModuleEntry* module_entry,
3856 const ClassFileStream* cfs) const {
3857
3858 if (!log_is_enabled(Info, class, load)) {
3859 return;
3860 }
3861
3862 ResourceMark rm;
3863 LogMessage(class, load) msg;
3864 stringStream info_stream;
3865
3866 // Name and class hierarchy info
3867 info_stream.print("%s", external_name());
3868
3869 // Source
3870 if (cfs != nullptr) {
3871 if (cfs->source() != nullptr) {
3872 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3873 if (module_name != nullptr) {
3874 // When the boot loader created the stream, it didn't know the module name
3875 // yet. Let's format it now.
3876 if (cfs->from_boot_loader_modules_image()) {
3877 info_stream.print(" source: jrt:/%s", module_name);
3878 } else {
3879 info_stream.print(" source: %s", cfs->source());
3880 }
3881 } else {
3882 info_stream.print(" source: %s", cfs->source());
3883 }
3884 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3885 Thread* current = Thread::current();
3886 Klass* caller = current->is_Java_thread() ?
3887 JavaThread::cast(current)->security_get_caller_class(1):
3888 nullptr;
3889 // caller can be null, for example, during a JVMTI VM_Init hook
3890 if (caller != nullptr) {
3891 info_stream.print(" source: instance of %s", caller->external_name());
3892 } else {
3893 // source is unknown
3894 }
3895 } else {
3896 oop class_loader = loader_data->class_loader();
3897 info_stream.print(" source: %s", class_loader->klass()->external_name());
3898 }
3899 } else {
3900 assert(this->is_shared(), "must be");
3901 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3902 info_stream.print(" source: shared objects file (top)");
3903 } else {
3904 info_stream.print(" source: shared objects file");
3905 }
3906 }
3907
3908 msg.info("%s", info_stream.as_string());
3909
3910 if (log_is_enabled(Debug, class, load)) {
3911 stringStream debug_stream;
3912
3913 // Class hierarchy info
3914 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
3915 p2i(this), p2i(superklass()));
3916
3917 // Interfaces
3918 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
3919 debug_stream.print(" interfaces:");
3920 int length = local_interfaces()->length();
3921 for (int i = 0; i < length; i++) {
3922 debug_stream.print(" " PTR_FORMAT,
3923 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3924 }
3925 }
3926
3927 // Class loader
3928 debug_stream.print(" loader: [");
3929 loader_data->print_value_on(&debug_stream);
3930 debug_stream.print("]");
3931
3932 // Classfile checksum
3933 if (cfs) {
3934 debug_stream.print(" bytes: %d checksum: %08x",
3935 cfs->length(),
3936 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3937 cfs->length()));
3938 }
3939
3940 msg.debug("%s", debug_stream.as_string());
3941 }
3942 }
3943
3944 void InstanceKlass::print_class_load_cause_logging() const {
3945 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
3946 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
3947 JavaThread* current = JavaThread::current();
3948 ResourceMark rm(current);
3949 const char* name = external_name();
3950
3951 if (LogClassLoadingCauseFor == nullptr ||
3952 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
3953 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
3954 return;
3955 }
3956
3957 // Log Java stack first
3958 {
3959 LogMessage(class, load, cause) msg;
3960 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
3961
3962 info_stream.print_cr("Java stack when loading %s:", name);
3963 current->print_stack_on(&info_stream);
3964 }
3965
3966 // Log native stack second
3967 if (log_cause_native) {
3968 // Log to string first so that lines can be indented
3969 stringStream stack_stream;
3970 char buf[O_BUFLEN];
3971 address lastpc = nullptr;
3972 if (os::platform_print_native_stack(&stack_stream, nullptr, buf, O_BUFLEN, lastpc)) {
3973 // We have printed the native stack in platform-specific code,
3974 // so nothing else to do in this case.
3975 } else {
3976 frame f = os::current_frame();
3977 VMError::print_native_stack(&stack_stream, f, current, true /*print_source_info */,
3978 -1 /* max stack_stream */, buf, O_BUFLEN);
3979 }
3980
3981 LogMessage(class, load, cause, native) msg;
3982 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
3983 info_stream.print_cr("Native stack when loading %s:", name);
3984
3985 // Print each native stack line to the log
3986 int size = (int) stack_stream.size();
3987 char* stack = stack_stream.as_string();
3988 char* stack_end = stack + size;
3989 char* line_start = stack;
3990 for (char* p = stack; p < stack_end; p++) {
3991 if (*p == '\n') {
3992 *p = '\0';
3993 info_stream.print_cr("\t%s", line_start);
3994 line_start = p + 1;
3995 }
3996 }
3997 if (line_start < stack_end) {
3998 info_stream.print_cr("\t%s", line_start);
3999 }
4000 }
4001 }
4002 }
4003
4004 // Verification
4005
4006 class VerifyFieldClosure: public BasicOopIterateClosure {
4007 protected:
4008 template <class T> void do_oop_work(T* p) {
4009 oop obj = RawAccess<>::oop_load(p);
4010 if (!oopDesc::is_oop_or_null(obj)) {
4011 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4012 Universe::print_on(tty);
4013 guarantee(false, "boom");
4014 }
4015 }
4016 public:
4017 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
4018 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4019 };
4020
4021 void InstanceKlass::verify_on(outputStream* st) {
4022 #ifndef PRODUCT
4023 // Avoid redundant verifies, this really should be in product.
4024 if (_verify_count == Universe::verify_count()) return;
4025 _verify_count = Universe::verify_count();
4026 #endif
4027
4028 // Verify Klass
4029 Klass::verify_on(st);
4030
4031 // Verify that klass is present in ClassLoaderData
4032 guarantee(class_loader_data()->contains_klass(this),
4033 "this class isn't found in class loader data");
4034
4035 // Verify vtables
4036 if (is_linked()) {
4037 // $$$ This used to be done only for m/s collections. Doing it
4038 // always seemed a valid generalization. (DLD -- 6/00)
4039 vtable().verify(st);
4040 }
4041
4042 // Verify first subklass
4043 if (subklass() != nullptr) {
4044 guarantee(subklass()->is_klass(), "should be klass");
4045 }
4046
4047 // Verify siblings
4048 Klass* super = this->super();
4049 Klass* sib = next_sibling();
4050 if (sib != nullptr) {
4051 if (sib == this) {
4052 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4053 }
4054
4055 guarantee(sib->is_klass(), "should be klass");
4056 guarantee(sib->super() == super, "siblings should have same superklass");
4057 }
4058
4059 // Verify local interfaces
4060 if (local_interfaces()) {
4061 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4062 for (int j = 0; j < local_interfaces->length(); j++) {
4063 InstanceKlass* e = local_interfaces->at(j);
4064 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4065 }
4066 }
4067
4068 // Verify transitive interfaces
4069 if (transitive_interfaces() != nullptr) {
4070 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4071 for (int j = 0; j < transitive_interfaces->length(); j++) {
4072 InstanceKlass* e = transitive_interfaces->at(j);
4073 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4074 }
4075 }
4076
4077 // Verify methods
4078 if (methods() != nullptr) {
4079 Array<Method*>* methods = this->methods();
4080 for (int j = 0; j < methods->length(); j++) {
4081 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4082 }
4083 for (int j = 0; j < methods->length() - 1; j++) {
4084 Method* m1 = methods->at(j);
4085 Method* m2 = methods->at(j + 1);
4086 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4087 }
4088 }
4089
4090 // Verify method ordering
4091 if (method_ordering() != nullptr) {
4092 Array<int>* method_ordering = this->method_ordering();
4093 int length = method_ordering->length();
4094 if (JvmtiExport::can_maintain_original_method_order() ||
4095 ((UseSharedSpaces || CDSConfig::is_dumping_archive()) && length != 0)) {
4096 guarantee(length == methods()->length(), "invalid method ordering length");
4097 jlong sum = 0;
4098 for (int j = 0; j < length; j++) {
4099 int original_index = method_ordering->at(j);
4100 guarantee(original_index >= 0, "invalid method ordering index");
4101 guarantee(original_index < length, "invalid method ordering index");
4102 sum += original_index;
4103 }
4104 // Verify sum of indices 0,1,...,length-1
4105 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4106 } else {
4107 guarantee(length == 0, "invalid method ordering length");
4108 }
4109 }
4110
4111 // Verify default methods
4112 if (default_methods() != nullptr) {
4113 Array<Method*>* methods = this->default_methods();
4114 for (int j = 0; j < methods->length(); j++) {
4115 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4116 }
4117 for (int j = 0; j < methods->length() - 1; j++) {
4118 Method* m1 = methods->at(j);
4119 Method* m2 = methods->at(j + 1);
4120 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4121 }
4122 }
4123
4124 // Verify JNI static field identifiers
4125 if (jni_ids() != nullptr) {
4126 jni_ids()->verify(this);
4127 }
4128
4129 // Verify other fields
4130 if (constants() != nullptr) {
4131 guarantee(constants()->is_constantPool(), "should be constant pool");
4132 }
4133 }
4134
4135 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4136 Klass::oop_verify_on(obj, st);
4137 VerifyFieldClosure blk;
4138 obj->oop_iterate(&blk);
4139 }
4140
4141
4142 // JNIid class for jfieldIDs only
4143 // Note to reviewers:
4144 // These JNI functions are just moved over to column 1 and not changed
4145 // in the compressed oops workspace.
4146 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
4147 _holder = holder;
4148 _offset = offset;
4149 _next = next;
4150 debug_only(_is_static_field_id = false;)
4151 }
4152
4153
4154 JNIid* JNIid::find(int offset) {
4155 JNIid* current = this;
4156 while (current != nullptr) {
4157 if (current->offset() == offset) return current;
4158 current = current->next();
4159 }
4160 return nullptr;
4161 }
4162
4163 void JNIid::deallocate(JNIid* current) {
4164 while (current != nullptr) {
4165 JNIid* next = current->next();
4166 delete current;
4167 current = next;
4168 }
4169 }
4170
4171
4172 void JNIid::verify(Klass* holder) {
4173 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4174 int end_field_offset;
4175 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
4176
4177 JNIid* current = this;
4178 while (current != nullptr) {
4179 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4180 #ifdef ASSERT
4181 int o = current->offset();
4182 if (current->is_static_field_id()) {
4183 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4184 }
4185 #endif
4186 current = current->next();
4187 }
4188 }
4189
4190 void InstanceKlass::set_init_state(ClassState state) {
4191 if (state > loaded) {
4192 assert_lock_strong(_init_monitor);
4193 }
4194 #ifdef ASSERT
4195 bool good_state = is_shared() ? (_init_state <= state)
4196 : (_init_state < state);
4197 bool link_failed = _init_state == being_linked && state == loaded;
4198 assert(good_state || state == allocated || link_failed, "illegal state transition");
4199 #endif
4200 assert(_init_thread == nullptr, "should be cleared before state change");
4201 Atomic::store(&_init_state, state);
4202 }
4203
4204 #if INCLUDE_JVMTI
4205
4206 // RedefineClasses() support for previous versions
4207
4208 // Globally, there is at least one previous version of a class to walk
4209 // during class unloading, which is saved because old methods in the class
4210 // are still running. Otherwise the previous version list is cleaned up.
4211 bool InstanceKlass::_should_clean_previous_versions = false;
4212
4213 // Returns true if there are previous versions of a class for class
4214 // unloading only. Also resets the flag to false. purge_previous_version
4215 // will set the flag to true if there are any left, i.e., if there's any
4216 // work to do for next time. This is to avoid the expensive code cache
4217 // walk in CLDG::clean_deallocate_lists().
4218 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4219 bool ret = _should_clean_previous_versions;
4220 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4221 ret ? "true" : "false");
4222 _should_clean_previous_versions = false;
4223 return ret;
4224 }
4225
4226 // This nulls out jmethodIDs for all methods in 'klass'
4227 // It needs to be called explicitly for all previous versions of a class because these may not be cleaned up
4228 // during class unloading.
4229 // We can not use the jmethodID cache associated with klass directly because the 'previous' versions
4230 // do not have the jmethodID cache filled in. Instead, we need to lookup jmethodID for each method and this
4231 // is expensive - O(n) for one jmethodID lookup. For all contained methods it is O(n^2).
4232 // The reason for expensive jmethodID lookup for each method is that there is no direct link between method and jmethodID.
4233 void InstanceKlass::clear_jmethod_ids(InstanceKlass* klass) {
4234 Array<Method*>* method_refs = klass->methods();
4235 for (int k = 0; k < method_refs->length(); k++) {
4236 Method* method = method_refs->at(k);
4237 if (method != nullptr && method->is_obsolete()) {
4238 method->clear_jmethod_id();
4239 }
4240 }
4241 }
4242
4243 // Purge previous versions before adding new previous versions of the class and
4244 // during class unloading.
4245 void InstanceKlass::purge_previous_version_list() {
4246 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4247 assert(has_been_redefined(), "Should only be called for main class");
4248
4249 // Quick exit.
4250 if (previous_versions() == nullptr) {
4251 return;
4252 }
4253
4254 // This klass has previous versions so see what we can cleanup
4255 // while it is safe to do so.
4256
4257 int deleted_count = 0; // leave debugging breadcrumbs
4258 int live_count = 0;
4259 ClassLoaderData* loader_data = class_loader_data();
4260 assert(loader_data != nullptr, "should never be null");
4261
4262 ResourceMark rm;
4263 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4264
4265 // previous versions are linked together through the InstanceKlass
4266 InstanceKlass* pv_node = previous_versions();
4267 InstanceKlass* last = this;
4268 int version = 0;
4269
4270 // check the previous versions list
4271 for (; pv_node != nullptr; ) {
4272
4273 ConstantPool* pvcp = pv_node->constants();
4274 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4275
4276 if (!pvcp->on_stack()) {
4277 // If the constant pool isn't on stack, none of the methods
4278 // are executing. Unlink this previous_version.
4279 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4280 // so will be deallocated during the next phase of class unloading.
4281 log_trace(redefine, class, iklass, purge)
4282 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4283 // Unlink from previous version list.
4284 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4285 InstanceKlass* next = pv_node->previous_versions();
4286 clear_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4287 pv_node->link_previous_versions(nullptr); // point next to null
4288 last->link_previous_versions(next);
4289 // Delete this node directly. Nothing is referring to it and we don't
4290 // want it to increase the counter for metadata to delete in CLDG.
4291 MetadataFactory::free_metadata(loader_data, pv_node);
4292 pv_node = next;
4293 deleted_count++;
4294 version++;
4295 continue;
4296 } else {
4297 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4298 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4299 live_count++;
4300 if (pvcp->is_shared()) {
4301 // Shared previous versions can never be removed so no cleaning is needed.
4302 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4303 } else {
4304 // Previous version alive, set that clean is needed for next time.
4305 _should_clean_previous_versions = true;
4306 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4307 }
4308 }
4309
4310 // next previous version
4311 last = pv_node;
4312 pv_node = pv_node->previous_versions();
4313 version++;
4314 }
4315 log_trace(redefine, class, iklass, purge)
4316 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4317 }
4318
4319 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4320 int emcp_method_count) {
4321 int obsolete_method_count = old_methods->length() - emcp_method_count;
4322
4323 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4324 _previous_versions != nullptr) {
4325 // We have a mix of obsolete and EMCP methods so we have to
4326 // clear out any matching EMCP method entries the hard way.
4327 int local_count = 0;
4328 for (int i = 0; i < old_methods->length(); i++) {
4329 Method* old_method = old_methods->at(i);
4330 if (old_method->is_obsolete()) {
4331 // only obsolete methods are interesting
4332 Symbol* m_name = old_method->name();
4333 Symbol* m_signature = old_method->signature();
4334
4335 // previous versions are linked together through the InstanceKlass
4336 int j = 0;
4337 for (InstanceKlass* prev_version = _previous_versions;
4338 prev_version != nullptr;
4339 prev_version = prev_version->previous_versions(), j++) {
4340
4341 Array<Method*>* method_refs = prev_version->methods();
4342 for (int k = 0; k < method_refs->length(); k++) {
4343 Method* method = method_refs->at(k);
4344
4345 if (!method->is_obsolete() &&
4346 method->name() == m_name &&
4347 method->signature() == m_signature) {
4348 // The current RedefineClasses() call has made all EMCP
4349 // versions of this method obsolete so mark it as obsolete
4350 log_trace(redefine, class, iklass, add)
4351 ("%s(%s): flush obsolete method @%d in version @%d",
4352 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4353
4354 method->set_is_obsolete();
4355 break;
4356 }
4357 }
4358
4359 // The previous loop may not find a matching EMCP method, but
4360 // that doesn't mean that we can optimize and not go any
4361 // further back in the PreviousVersion generations. The EMCP
4362 // method for this generation could have already been made obsolete,
4363 // but there still may be an older EMCP method that has not
4364 // been made obsolete.
4365 }
4366
4367 if (++local_count >= obsolete_method_count) {
4368 // no more obsolete methods so bail out now
4369 break;
4370 }
4371 }
4372 }
4373 }
4374 }
4375
4376 // Save the scratch_class as the previous version if any of the methods are running.
4377 // The previous_versions are used to set breakpoints in EMCP methods and they are
4378 // also used to clean MethodData links to redefined methods that are no longer running.
4379 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4380 int emcp_method_count) {
4381 assert(Thread::current()->is_VM_thread(),
4382 "only VMThread can add previous versions");
4383
4384 ResourceMark rm;
4385 log_trace(redefine, class, iklass, add)
4386 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4387
4388 // Clean out old previous versions for this class
4389 purge_previous_version_list();
4390
4391 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4392 // a previous redefinition may be made obsolete by this redefinition.
4393 Array<Method*>* old_methods = scratch_class->methods();
4394 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4395
4396 // If the constant pool for this previous version of the class
4397 // is not marked as being on the stack, then none of the methods
4398 // in this previous version of the class are on the stack so
4399 // we don't need to add this as a previous version.
4400 ConstantPool* cp_ref = scratch_class->constants();
4401 if (!cp_ref->on_stack()) {
4402 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4403 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4404 return;
4405 }
4406
4407 // Add previous version if any methods are still running or if this is
4408 // a shared class which should never be removed.
4409 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4410 scratch_class->link_previous_versions(previous_versions());
4411 link_previous_versions(scratch_class);
4412 if (cp_ref->is_shared()) {
4413 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4414 } else {
4415 // We only set clean_previous_versions flag for processing during class
4416 // unloading for non-shared classes.
4417 _should_clean_previous_versions = true;
4418 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4419 }
4420 } // end add_previous_version()
4421
4422 #endif // INCLUDE_JVMTI
4423
4424 Method* InstanceKlass::method_with_idnum(int idnum) {
4425 Method* m = nullptr;
4426 if (idnum < methods()->length()) {
4427 m = methods()->at(idnum);
4428 }
4429 if (m == nullptr || m->method_idnum() != idnum) {
4430 for (int index = 0; index < methods()->length(); ++index) {
4431 m = methods()->at(index);
4432 if (m->method_idnum() == idnum) {
4433 return m;
4434 }
4435 }
4436 // None found, return null for the caller to handle.
4437 return nullptr;
4438 }
4439 return m;
4440 }
4441
4442
4443 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4444 if (idnum >= methods()->length()) {
4445 return nullptr;
4446 }
4447 Method* m = methods()->at(idnum);
4448 if (m != nullptr && m->orig_method_idnum() == idnum) {
4449 return m;
4450 }
4451 // Obsolete method idnum does not match the original idnum
4452 for (int index = 0; index < methods()->length(); ++index) {
4453 m = methods()->at(index);
4454 if (m->orig_method_idnum() == idnum) {
4455 return m;
4456 }
4457 }
4458 // None found, return null for the caller to handle.
4459 return nullptr;
4460 }
4461
4462
4463 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4464 InstanceKlass* holder = get_klass_version(version);
4465 if (holder == nullptr) {
4466 return nullptr; // The version of klass is gone, no method is found
4467 }
4468 Method* method = holder->method_with_orig_idnum(idnum);
4469 return method;
4470 }
4471
4472 #if INCLUDE_JVMTI
4473 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4474 return _cached_class_file;
4475 }
4476
4477 jint InstanceKlass::get_cached_class_file_len() {
4478 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4479 }
4480
4481 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4482 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4483 }
4484 #endif
4485
4486 // Make a step iterating over the class hierarchy under the root class.
4487 // Skips subclasses if requested.
4488 void ClassHierarchyIterator::next() {
4489 assert(_current != nullptr, "required");
4490 if (_visit_subclasses && _current->subklass() != nullptr) {
4491 _current = _current->subklass();
4492 return; // visit next subclass
4493 }
4494 _visit_subclasses = true; // reset
4495 while (_current->next_sibling() == nullptr && _current != _root) {
4496 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4497 }
4498 if (_current == _root) {
4499 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4500 _current = nullptr;
4501 return;
4502 }
4503 _current = _current->next_sibling();
4504 return; // visit next sibling subclass
4505 }