1 /*
2 * Copyright (c) 1997, 2025, 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 "cds/aotClassInitializer.hpp"
26 #include "cds/archiveUtils.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/cdsEnumKlass.hpp"
29 #include "cds/classListWriter.hpp"
30 #include "cds/heapShared.hpp"
31 #include "cds/metaspaceShared.hpp"
32 #include "classfile/classFileParser.hpp"
33 #include "classfile/classFileStream.hpp"
34 #include "classfile/classLoader.hpp"
35 #include "classfile/classLoaderData.inline.hpp"
36 #include "classfile/javaClasses.hpp"
37 #include "classfile/moduleEntry.hpp"
38 #include "classfile/systemDictionary.hpp"
39 #include "classfile/systemDictionaryShared.hpp"
40 #include "classfile/verifier.hpp"
41 #include "classfile/vmClasses.hpp"
42 #include "classfile/vmSymbols.hpp"
43 #include "code/codeCache.hpp"
44 #include "code/dependencyContext.hpp"
45 #include "compiler/compilationPolicy.hpp"
46 #include "compiler/compileBroker.hpp"
47 #include "gc/shared/collectedHeap.inline.hpp"
48 #include "interpreter/bytecodeStream.hpp"
49 #include "interpreter/oopMapCache.hpp"
50 #include "interpreter/rewriter.hpp"
51 #include "jvm.h"
52 #include "jvmtifiles/jvmti.h"
53 #include "logging/log.hpp"
54 #include "klass.inline.hpp"
55 #include "logging/logMessage.hpp"
56 #include "logging/logStream.hpp"
57 #include "memory/allocation.inline.hpp"
58 #include "memory/iterator.inline.hpp"
59 #include "memory/metadataFactory.hpp"
60 #include "memory/metaspaceClosure.hpp"
61 #include "memory/oopFactory.hpp"
62 #include "memory/resourceArea.hpp"
63 #include "memory/universe.hpp"
64 #include "oops/fieldStreams.inline.hpp"
65 #include "oops/constantPool.hpp"
66 #include "oops/instanceClassLoaderKlass.hpp"
67 #include "oops/instanceKlass.inline.hpp"
68 #include "oops/instanceMirrorKlass.hpp"
69 #include "oops/instanceOop.hpp"
70 #include "oops/instanceStackChunkKlass.hpp"
71 #include "oops/klass.inline.hpp"
72 #include "oops/method.hpp"
73 #include "oops/oop.inline.hpp"
74 #include "oops/recordComponent.hpp"
75 #include "oops/symbol.hpp"
76 #include "prims/jvmtiExport.hpp"
77 #include "prims/jvmtiRedefineClasses.hpp"
78 #include "prims/jvmtiThreadState.hpp"
79 #include "prims/methodComparator.hpp"
80 #include "runtime/arguments.hpp"
81 #include "runtime/deoptimization.hpp"
82 #include "runtime/atomic.hpp"
83 #include "runtime/fieldDescriptor.inline.hpp"
84 #include "runtime/handles.inline.hpp"
85 #include "runtime/javaCalls.hpp"
86 #include "runtime/javaThread.inline.hpp"
87 #include "runtime/mutexLocker.hpp"
88 #include "runtime/orderAccess.hpp"
89 #include "runtime/os.inline.hpp"
90 #include "runtime/reflection.hpp"
91 #include "runtime/synchronizer.hpp"
92 #include "runtime/threads.hpp"
93 #include "services/classLoadingService.hpp"
94 #include "services/finalizerService.hpp"
95 #include "services/threadService.hpp"
96 #include "utilities/dtrace.hpp"
97 #include "utilities/events.hpp"
98 #include "utilities/macros.hpp"
99 #include "utilities/nativeStackPrinter.hpp"
100 #include "utilities/stringUtils.hpp"
101 #ifdef COMPILER1
102 #include "c1/c1_Compiler.hpp"
103 #endif
104 #if INCLUDE_JFR
105 #include "jfr/jfrEvents.hpp"
106 #endif
107
108 #ifdef DTRACE_ENABLED
109
110
111 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
112 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
113 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
114 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
115 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
116 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
117 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
118 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
119 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
120 { \
121 char* data = nullptr; \
122 int len = 0; \
123 Symbol* clss_name = name(); \
124 if (clss_name != nullptr) { \
125 data = (char*)clss_name->bytes(); \
126 len = clss_name->utf8_length(); \
127 } \
128 HOTSPOT_CLASS_INITIALIZATION_##type( \
129 data, len, (void*)class_loader(), thread_type); \
130 }
131
132 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
133 { \
134 char* data = nullptr; \
135 int len = 0; \
136 Symbol* clss_name = name(); \
137 if (clss_name != nullptr) { \
138 data = (char*)clss_name->bytes(); \
139 len = clss_name->utf8_length(); \
140 } \
141 HOTSPOT_CLASS_INITIALIZATION_##type( \
142 data, len, (void*)class_loader(), thread_type, wait); \
143 }
144
145 #else // ndef DTRACE_ENABLED
146
147 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
148 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
149
150 #endif // ndef DTRACE_ENABLED
151
152 bool InstanceKlass::_finalization_enabled = true;
153
154 static inline bool is_class_loader(const Symbol* class_name,
155 const ClassFileParser& parser) {
156 assert(class_name != nullptr, "invariant");
157
158 if (class_name == vmSymbols::java_lang_ClassLoader()) {
159 return true;
160 }
161
162 if (vmClasses::ClassLoader_klass_loaded()) {
163 const Klass* const super_klass = parser.super_klass();
164 if (super_klass != nullptr) {
165 if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
166 return true;
167 }
168 }
169 }
170 return false;
171 }
172
173 static inline bool is_stack_chunk_class(const Symbol* class_name,
174 const ClassLoaderData* loader_data) {
175 return (class_name == vmSymbols::jdk_internal_vm_StackChunk() &&
176 loader_data->is_the_null_class_loader_data());
177 }
178
179 // private: called to verify that k is a static member of this nest.
180 // We know that k is an instance class in the same package and hence the
181 // same classloader.
182 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
183 assert(!is_hidden(), "unexpected hidden class");
184 if (_nest_members == nullptr || _nest_members == Universe::the_empty_short_array()) {
185 if (log_is_enabled(Trace, class, nestmates)) {
186 ResourceMark rm(current);
187 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
188 k->external_name(), this->external_name());
189 }
190 return false;
191 }
192
193 if (log_is_enabled(Trace, class, nestmates)) {
194 ResourceMark rm(current);
195 log_trace(class, nestmates)("Checking nest membership of %s in %s",
196 k->external_name(), this->external_name());
197 }
198
199 // Check for the named class in _nest_members.
200 // We don't resolve, or load, any classes.
201 for (int i = 0; i < _nest_members->length(); i++) {
202 int cp_index = _nest_members->at(i);
203 Symbol* name = _constants->klass_name_at(cp_index);
204 if (name == k->name()) {
205 log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
206 return true;
207 }
208 }
209 log_trace(class, nestmates)("- class is NOT a nest member!");
210 return false;
211 }
212
213 // Called to verify that k is a permitted subclass of this class.
214 // The incoming stringStream is used to format the messages for error logging and for the caller
215 // to use for exception throwing.
216 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const {
217 Thread* current = Thread::current();
218 assert(k != nullptr, "sanity check");
219 assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
220 "unexpected empty _permitted_subclasses array");
221
222 if (log_is_enabled(Trace, class, sealed)) {
223 ResourceMark rm(current);
224 log_trace(class, sealed)("Checking for permitted subclass %s in %s",
225 k->external_name(), this->external_name());
226 }
227
228 // Check that the class and its super are in the same module.
229 if (k->module() != this->module()) {
230 ss.print("Failed same module check: subclass %s is in module '%s' with loader %s, "
231 "and sealed class %s is in module '%s' with loader %s",
232 k->external_name(),
233 k->module()->name_as_C_string(),
234 k->module()->loader_data()->loader_name_and_id(),
235 this->external_name(),
236 this->module()->name_as_C_string(),
237 this->module()->loader_data()->loader_name_and_id());
238 log_trace(class, sealed)(" - %s", ss.as_string());
239 return false;
240 }
241
242 if (!k->is_public() && !is_same_class_package(k)) {
243 ss.print("Failed same package check: non-public subclass %s is in package '%s' with classloader %s, "
244 "and sealed class %s is in package '%s' with classloader %s",
245 k->external_name(),
246 k->package() != nullptr ? k->package()->name()->as_C_string() : "unnamed",
247 k->module()->loader_data()->loader_name_and_id(),
248 this->external_name(),
249 this->package() != nullptr ? this->package()->name()->as_C_string() : "unnamed",
250 this->module()->loader_data()->loader_name_and_id());
251 log_trace(class, sealed)(" - %s", ss.as_string());
252 return false;
253 }
254
255 for (int i = 0; i < _permitted_subclasses->length(); i++) {
256 int cp_index = _permitted_subclasses->at(i);
257 Symbol* name = _constants->klass_name_at(cp_index);
258 if (name == k->name()) {
259 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
260 return true;
261 }
262 }
263
264 ss.print("Failed listed permitted subclass check: class %s is not a permitted subclass of %s",
265 k->external_name(), this->external_name());
266 log_trace(class, sealed)(" - %s", ss.as_string());
267 return false;
268 }
269
270 // Return nest-host class, resolving, validating and saving it if needed.
271 // In cases where this is called from a thread that cannot do classloading
272 // (such as a native JIT thread) then we simply return null, which in turn
273 // causes the access check to return false. Such code will retry the access
274 // from a more suitable environment later. Otherwise the _nest_host is always
275 // set once this method returns.
276 // Any errors from nest-host resolution must be preserved so they can be queried
277 // from higher-level access checking code, and reported as part of access checking
278 // exceptions.
279 // VirtualMachineErrors are propagated with a null return.
280 // Under any conditions where the _nest_host can be set to non-null the resulting
281 // value of it and, if applicable, the nest host resolution/validation error,
282 // are idempotent.
283 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
284 InstanceKlass* nest_host_k = _nest_host;
285 if (nest_host_k != nullptr) {
286 return nest_host_k;
287 }
288
289 ResourceMark rm(THREAD);
290
291 // need to resolve and save our nest-host class.
292 if (_nest_host_index != 0) { // we have a real nest_host
293 // Before trying to resolve check if we're in a suitable context
294 bool can_resolve = THREAD->can_call_java();
295 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
296 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
297 this->external_name());
298 return nullptr; // sentinel to say "try again from a different context"
299 }
300
301 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
302 this->external_name(),
303 _constants->klass_name_at(_nest_host_index)->as_C_string());
304
305 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
306 if (HAS_PENDING_EXCEPTION) {
307 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
308 return nullptr; // propagate VMEs
309 }
310 stringStream ss;
311 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
312 ss.print("Nest host resolution of %s with host %s failed: ",
313 this->external_name(), target_host_class);
314 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
315 const char* msg = ss.as_string(true /* on C-heap */);
316 constantPoolHandle cph(THREAD, constants());
317 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
318 CLEAR_PENDING_EXCEPTION;
319
320 log_trace(class, nestmates)("%s", msg);
321 } else {
322 // A valid nest-host is an instance class in the current package that lists this
323 // class as a nest member. If any of these conditions are not met the class is
324 // its own nest-host.
325 const char* error = nullptr;
326
327 // JVMS 5.4.4 indicates package check comes first
328 if (is_same_class_package(k)) {
329 // Now check actual membership. We can't be a member if our "host" is
330 // not an instance class.
331 if (k->is_instance_klass()) {
332 nest_host_k = InstanceKlass::cast(k);
333 bool is_member = nest_host_k->has_nest_member(THREAD, this);
334 if (is_member) {
335 _nest_host = nest_host_k; // save resolved nest-host value
336
337 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
338 this->external_name(), k->external_name());
339 return nest_host_k;
340 } else {
341 error = "current type is not listed as a nest member";
342 }
343 } else {
344 error = "host is not an instance class";
345 }
346 } else {
347 error = "types are in different packages";
348 }
349
350 // something went wrong, so record what and log it
351 {
352 stringStream ss;
353 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
354 this->external_name(),
355 this->class_loader_data()->loader_name_and_id(),
356 k->external_name(),
357 k->class_loader_data()->loader_name_and_id(),
358 error);
359 const char* msg = ss.as_string(true /* on C-heap */);
360 constantPoolHandle cph(THREAD, constants());
361 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
362 log_trace(class, nestmates)("%s", msg);
363 }
364 }
365 } else {
366 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
367 this->external_name());
368 }
369
370 // Either not in an explicit nest, or else an error occurred, so
371 // the nest-host is set to `this`. Any thread that sees this assignment
372 // will also see any setting of nest_host_error(), if applicable.
373 return (_nest_host = this);
374 }
375
376 // Dynamic nest member support: set this class's nest host to the given class.
377 // This occurs as part of the class definition, as soon as the instanceKlass
378 // has been created and doesn't require further resolution. The code:
379 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
380 // results in:
381 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
382 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
383 // We also know the "host" is a valid nest-host in the same package so we can
384 // assert some of those facts.
385 void InstanceKlass::set_nest_host(InstanceKlass* host) {
386 assert(is_hidden(), "must be a hidden class");
387 assert(host != nullptr, "null nest host specified");
388 assert(_nest_host == nullptr, "current class has resolved nest-host");
389 assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
390 nest_host_error());
391 assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
392 (host->_nest_host == host), "proposed host is not a valid nest-host");
393 // Can't assert this as package is not set yet:
394 // assert(is_same_class_package(host), "proposed host is in wrong package");
395
396 if (log_is_enabled(Trace, class, nestmates)) {
397 ResourceMark rm;
398 const char* msg = "";
399 // a hidden class does not expect a statically defined nest-host
400 if (_nest_host_index > 0) {
401 msg = "(the NestHost attribute in the current class is ignored)";
402 } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
403 msg = "(the NestMembers attribute in the current class is ignored)";
404 }
405 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
406 this->external_name(),
407 host->external_name(),
408 msg);
409 }
410 // set dynamic nest host
411 _nest_host = host;
412 // Record dependency to keep nest host from being unloaded before this class.
413 ClassLoaderData* this_key = class_loader_data();
414 assert(this_key != nullptr, "sanity");
415 this_key->record_dependency(host);
416 }
417
418 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
419 // or we are k's nest_host - all of which is covered by comparing the two
420 // resolved_nest_hosts.
421 // Any exceptions (i.e. VMEs) are propagated.
422 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
423
424 assert(this != k, "this should be handled by higher-level code");
425
426 // Per JVMS 5.4.4 we first resolve and validate the current class, then
427 // the target class k.
428
429 InstanceKlass* cur_host = nest_host(CHECK_false);
430 if (cur_host == nullptr) {
431 return false;
432 }
433
434 Klass* k_nest_host = k->nest_host(CHECK_false);
435 if (k_nest_host == nullptr) {
436 return false;
437 }
438
439 bool access = (cur_host == k_nest_host);
440
441 ResourceMark rm(THREAD);
442 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
443 this->external_name(),
444 access ? "" : "NOT ",
445 k->external_name());
446 return access;
447 }
448
449 const char* InstanceKlass::nest_host_error() {
450 if (_nest_host_index == 0) {
451 return nullptr;
452 } else {
453 constantPoolHandle cph(Thread::current(), constants());
454 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
455 }
456 }
457
458 void* InstanceKlass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size,
459 bool use_class_space, TRAPS) throw() {
460 return Metaspace::allocate(loader_data, word_size, ClassType, use_class_space, THREAD);
461 }
462
463 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
464 const int size = InstanceKlass::size(parser.vtable_size(),
465 parser.itable_size(),
466 nonstatic_oop_map_size(parser.total_oop_map_count()),
467 parser.is_interface());
468
469 const Symbol* const class_name = parser.class_name();
470 assert(class_name != nullptr, "invariant");
471 ClassLoaderData* loader_data = parser.loader_data();
472 assert(loader_data != nullptr, "invariant");
473
474 InstanceKlass* ik;
475 const bool use_class_space = parser.klass_needs_narrow_id();
476
477 // Allocation
478 if (parser.is_instance_ref_klass()) {
479 // java.lang.ref.Reference
480 ik = new (loader_data, size, use_class_space, THREAD) InstanceRefKlass(parser);
481 } else if (class_name == vmSymbols::java_lang_Class()) {
482 // mirror - java.lang.Class
483 ik = new (loader_data, size, use_class_space, THREAD) InstanceMirrorKlass(parser);
484 } else if (is_stack_chunk_class(class_name, loader_data)) {
485 // stack chunk
486 ik = new (loader_data, size, use_class_space, THREAD) InstanceStackChunkKlass(parser);
487 } else if (is_class_loader(class_name, parser)) {
488 // class loader - java.lang.ClassLoader
489 ik = new (loader_data, size, use_class_space, THREAD) InstanceClassLoaderKlass(parser);
490 } else {
491 // normal
492 ik = new (loader_data, size, use_class_space, THREAD) InstanceKlass(parser);
493 }
494
495 if (ik != nullptr && UseCompressedClassPointers && use_class_space) {
496 assert(CompressedKlassPointers::is_encodable(ik),
497 "Klass " PTR_FORMAT "needs a narrow Klass ID, but is not encodable", p2i(ik));
498 }
499
500 // Check for pending exception before adding to the loader data and incrementing
501 // class count. Can get OOM here.
502 if (HAS_PENDING_EXCEPTION) {
503 return nullptr;
504 }
505
506 return ik;
507 }
508
509
510 // copy method ordering from resource area to Metaspace
511 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
512 if (m != nullptr) {
513 // allocate a new array and copy contents (memcpy?)
514 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
515 for (int i = 0; i < m->length(); i++) {
516 _method_ordering->at_put(i, m->at(i));
517 }
518 } else {
519 _method_ordering = Universe::the_empty_int_array();
520 }
521 }
522
523 // create a new array of vtable_indices for default methods
524 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
525 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
526 assert(default_vtable_indices() == nullptr, "only create once");
527 set_default_vtable_indices(vtable_indices);
528 return vtable_indices;
529 }
530
531
532 InstanceKlass::InstanceKlass() {
533 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
534 }
535
536 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, ReferenceType reference_type) :
537 Klass(kind),
538 _nest_members(nullptr),
539 _nest_host(nullptr),
540 _permitted_subclasses(nullptr),
541 _record_components(nullptr),
542 _static_field_size(parser.static_field_size()),
543 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
544 _itable_len(parser.itable_size()),
545 _nest_host_index(0),
546 _init_state(allocated),
547 _reference_type(reference_type),
548 _init_thread(nullptr)
549 {
550 set_vtable_length(parser.vtable_size());
551 set_access_flags(parser.access_flags());
552 if (parser.is_hidden()) set_is_hidden();
553 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
554 false));
555
556 assert(nullptr == _methods, "underlying memory not zeroed?");
557 assert(is_instance_klass(), "is layout incorrect?");
558 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
559 }
560
561 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
562 Array<Method*>* methods) {
563 if (methods != nullptr && methods != Universe::the_empty_method_array() &&
564 !methods->is_shared()) {
565 for (int i = 0; i < methods->length(); i++) {
566 Method* method = methods->at(i);
567 if (method == nullptr) continue; // maybe null if error processing
568 // Only want to delete methods that are not executing for RedefineClasses.
569 // The previous version will point to them so they're not totally dangling
570 assert (!method->on_stack(), "shouldn't be called with methods on stack");
571 MetadataFactory::free_metadata(loader_data, method);
572 }
573 MetadataFactory::free_array<Method*>(loader_data, methods);
574 }
575 }
576
577 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
578 const Klass* super_klass,
579 Array<InstanceKlass*>* local_interfaces,
580 Array<InstanceKlass*>* transitive_interfaces) {
581 // Only deallocate transitive interfaces if not empty, same as super class
582 // or same as local interfaces. See code in parseClassFile.
583 Array<InstanceKlass*>* ti = transitive_interfaces;
584 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
585 // check that the interfaces don't come from super class
586 Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
587 InstanceKlass::cast(super_klass)->transitive_interfaces();
588 if (ti != sti && ti != nullptr && !ti->is_shared()) {
589 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
590 }
591 }
592
593 // local interfaces can be empty
594 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
595 local_interfaces != nullptr && !local_interfaces->is_shared()) {
596 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
597 }
598 }
599
600 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
601 Array<RecordComponent*>* record_components) {
602 if (record_components != nullptr && !record_components->is_shared()) {
603 for (int i = 0; i < record_components->length(); i++) {
604 RecordComponent* record_component = record_components->at(i);
605 MetadataFactory::free_metadata(loader_data, record_component);
606 }
607 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
608 }
609 }
610
611 // This function deallocates the metadata and C heap pointers that the
612 // InstanceKlass points to.
613 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
614 // Orphan the mirror first, CMS thinks it's still live.
615 if (java_mirror() != nullptr) {
616 java_lang_Class::set_klass(java_mirror(), nullptr);
617 }
618
619 // Also remove mirror from handles
620 loader_data->remove_handle(_java_mirror);
621
622 // Need to take this class off the class loader data list.
623 loader_data->remove_class(this);
624
625 // The array_klass for this class is created later, after error handling.
626 // For class redefinition, we keep the original class so this scratch class
627 // doesn't have an array class. Either way, assert that there is nothing
628 // to deallocate.
629 assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
630
631 // Release C heap allocated data that this points to, which includes
632 // reference counting symbol names.
633 // Can't release the constant pool or MethodData C heap data here because the constant
634 // pool can be deallocated separately from the InstanceKlass for default methods and
635 // redefine classes. MethodData can also be released separately.
636 release_C_heap_structures(/* release_sub_metadata */ false);
637
638 deallocate_methods(loader_data, methods());
639 set_methods(nullptr);
640
641 deallocate_record_components(loader_data, record_components());
642 set_record_components(nullptr);
643
644 if (method_ordering() != nullptr &&
645 method_ordering() != Universe::the_empty_int_array() &&
646 !method_ordering()->is_shared()) {
647 MetadataFactory::free_array<int>(loader_data, method_ordering());
648 }
649 set_method_ordering(nullptr);
650
651 // default methods can be empty
652 if (default_methods() != nullptr &&
653 default_methods() != Universe::the_empty_method_array() &&
654 !default_methods()->is_shared()) {
655 MetadataFactory::free_array<Method*>(loader_data, default_methods());
656 }
657 // Do NOT deallocate the default methods, they are owned by superinterfaces.
658 set_default_methods(nullptr);
659
660 // default methods vtable indices can be empty
661 if (default_vtable_indices() != nullptr &&
662 !default_vtable_indices()->is_shared()) {
663 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
664 }
665 set_default_vtable_indices(nullptr);
666
667
668 // This array is in Klass, but remove it with the InstanceKlass since
669 // this place would be the only caller and it can share memory with transitive
670 // interfaces.
671 if (secondary_supers() != nullptr &&
672 secondary_supers() != Universe::the_empty_klass_array() &&
673 // see comments in compute_secondary_supers about the following cast
674 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
675 !secondary_supers()->is_shared()) {
676 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
677 }
678 set_secondary_supers(nullptr, SECONDARY_SUPERS_BITMAP_EMPTY);
679
680 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
681 set_transitive_interfaces(nullptr);
682 set_local_interfaces(nullptr);
683
684 if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->is_shared()) {
685 MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
686 }
687 set_fieldinfo_stream(nullptr);
688
689 if (fields_status() != nullptr && !fields_status()->is_shared()) {
690 MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
691 }
692 set_fields_status(nullptr);
693
694 // If a method from a redefined class is using this constant pool, don't
695 // delete it, yet. The new class's previous version will point to this.
696 if (constants() != nullptr) {
697 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
698 if (!constants()->is_shared()) {
699 MetadataFactory::free_metadata(loader_data, constants());
700 }
701 // Delete any cached resolution errors for the constant pool
702 SystemDictionary::delete_resolution_error(constants());
703
704 set_constants(nullptr);
705 }
706
707 if (inner_classes() != nullptr &&
708 inner_classes() != Universe::the_empty_short_array() &&
709 !inner_classes()->is_shared()) {
710 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
711 }
712 set_inner_classes(nullptr);
713
714 if (nest_members() != nullptr &&
715 nest_members() != Universe::the_empty_short_array() &&
716 !nest_members()->is_shared()) {
717 MetadataFactory::free_array<jushort>(loader_data, nest_members());
718 }
719 set_nest_members(nullptr);
720
721 if (permitted_subclasses() != nullptr &&
722 permitted_subclasses() != Universe::the_empty_short_array() &&
723 !permitted_subclasses()->is_shared()) {
724 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
725 }
726 set_permitted_subclasses(nullptr);
727
728 // We should deallocate the Annotations instance if it's not in shared spaces.
729 if (annotations() != nullptr && !annotations()->is_shared()) {
730 MetadataFactory::free_metadata(loader_data, annotations());
731 }
732 set_annotations(nullptr);
733
734 SystemDictionaryShared::handle_class_unloading(this);
735
736 #if INCLUDE_CDS_JAVA_HEAP
737 if (CDSConfig::is_dumping_heap()) {
738 HeapShared::remove_scratch_objects(this);
739 }
740 #endif
741 }
742
743 bool InstanceKlass::is_record() const {
744 return _record_components != nullptr &&
745 is_final() &&
746 java_super() == vmClasses::Record_klass();
747 }
748
749 bool InstanceKlass::is_sealed() const {
750 return _permitted_subclasses != nullptr &&
751 _permitted_subclasses != Universe::the_empty_short_array();
752 }
753
754 // JLS 8.9: An enum class is either implicitly final and derives
755 // from java.lang.Enum, or else is implicitly sealed to its
756 // anonymous subclasses. This query detects both kinds.
757 // It does not validate the finality or
758 // sealing conditions: it merely checks for a super of Enum.
759 // This is sufficient for recognizing well-formed enums.
760 bool InstanceKlass::is_enum_subclass() const {
761 InstanceKlass* s = java_super();
762 return (s == vmClasses::Enum_klass() ||
763 (s != nullptr && s->java_super() == vmClasses::Enum_klass()));
764 }
765
766 bool InstanceKlass::should_be_initialized() const {
767 return !is_initialized();
768 }
769
770 klassItable InstanceKlass::itable() const {
771 return klassItable(const_cast<InstanceKlass*>(this));
772 }
773
774 // JVMTI spec thinks there are signers and protection domain in the
775 // instanceKlass. These accessors pretend these fields are there.
776 // The hprof specification also thinks these fields are in InstanceKlass.
777 oop InstanceKlass::protection_domain() const {
778 // return the protection_domain from the mirror
779 return java_lang_Class::protection_domain(java_mirror());
780 }
781
782 objArrayOop InstanceKlass::signers() const {
783 // return the signers from the mirror
784 return java_lang_Class::signers(java_mirror());
785 }
786
787 oop InstanceKlass::init_lock() const {
788 // return the init lock from the mirror
789 oop lock = java_lang_Class::init_lock(java_mirror());
790 // Prevent reordering with any access of initialization state
791 OrderAccess::loadload();
792 assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
793 "only fully initialized state can have a null lock");
794 return lock;
795 }
796
797 // Set the initialization lock to null so the object can be GC'ed. Any racing
798 // threads to get this lock will see a null lock and will not lock.
799 // That's okay because they all check for initialized state after getting
800 // the lock and return.
801 void InstanceKlass::fence_and_clear_init_lock() {
802 // make sure previous stores are all done, notably the init_state.
803 OrderAccess::storestore();
804 java_lang_Class::clear_init_lock(java_mirror());
805 assert(!is_not_initialized(), "class must be initialized now");
806 }
807
808
809 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
810 // process. The step comments refers to the procedure described in that section.
811 // Note: implementation moved to static method to expose the this pointer.
812 void InstanceKlass::initialize(TRAPS) {
813 if (this->should_be_initialized()) {
814 initialize_impl(CHECK);
815 // Note: at this point the class may be initialized
816 // OR it may be in the state of being initialized
817 // in case of recursive initialization!
818 } else {
819 assert(is_initialized(), "sanity check");
820 }
821 }
822
823 #ifdef ASSERT
824 void InstanceKlass::assert_no_clinit_will_run_for_aot_initialized_class() const {
825 assert(has_aot_initialized_mirror(), "must be");
826
827 InstanceKlass* s = java_super();
828 if (s != nullptr) {
829 DEBUG_ONLY(ResourceMark rm);
830 assert(s->is_initialized(), "super class %s of aot-inited class %s must have been initialized",
831 s->external_name(), external_name());
832 s->assert_no_clinit_will_run_for_aot_initialized_class();
833 }
834
835 Array<InstanceKlass*>* interfaces = local_interfaces();
836 int len = interfaces->length();
837 for (int i = 0; i < len; i++) {
838 InstanceKlass* intf = interfaces->at(i);
839 if (!intf->is_initialized()) {
840 ResourceMark rm;
841 // Note: an interface needs to be marked as is_initialized() only if
842 // - it has a <clinit>
843 // - it has declared a default method.
844 assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false),
845 "uninitialized super interface %s of aot-inited class %s must not have <clinit>",
846 intf->external_name(), external_name());
847 }
848 }
849 }
850 #endif
851
852 #if INCLUDE_CDS
853 void InstanceKlass::initialize_with_aot_initialized_mirror(TRAPS) {
854 assert(has_aot_initialized_mirror(), "must be");
855 assert(CDSConfig::is_loading_heap(), "must be");
856 assert(CDSConfig::is_using_aot_linked_classes(), "must be");
857 assert_no_clinit_will_run_for_aot_initialized_class();
858
859 if (is_initialized()) {
860 return;
861 }
862
863 if (log_is_enabled(Info, cds, init)) {
864 ResourceMark rm;
865 log_info(cds, init)("%s (aot-inited)", external_name());
866 }
867
868 link_class(CHECK);
869
870 #ifdef ASSERT
871 {
872 Handle h_init_lock(THREAD, init_lock());
873 ObjectLocker ol(h_init_lock, THREAD);
874 assert(!is_initialized(), "sanity");
875 assert(!is_being_initialized(), "sanity");
876 assert(!is_in_error_state(), "sanity");
877 }
878 #endif
879
880 set_init_thread(THREAD);
881 AOTClassInitializer::call_runtime_setup(THREAD, this);
882 set_initialization_state_and_notify(fully_initialized, CHECK);
883 }
884 #endif
885
886 bool InstanceKlass::verify_code(TRAPS) {
887 // 1) Verify the bytecodes
888 return Verifier::verify(this, should_verify_class(), THREAD);
889 }
890
891 void InstanceKlass::link_class(TRAPS) {
892 assert(is_loaded(), "must be loaded");
893 if (!is_linked()) {
894 link_class_impl(CHECK);
895 }
896 }
897
898 // Called to verify that a class can link during initialization, without
899 // throwing a VerifyError.
900 bool InstanceKlass::link_class_or_fail(TRAPS) {
901 assert(is_loaded(), "must be loaded");
902 if (!is_linked()) {
903 link_class_impl(CHECK_false);
904 }
905 return is_linked();
906 }
907
908 bool InstanceKlass::link_class_impl(TRAPS) {
909 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
910 // This is for CDS static dump only -- we use the in_error_state to indicate that
911 // the class has failed verification. Throwing the NoClassDefFoundError here is just
912 // a convenient way to stop repeat attempts to verify the same (bad) class.
913 //
914 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
915 // if we are executing Java code. This is not a problem for CDS dumping phase since
916 // it doesn't execute any Java code.
917 ResourceMark rm(THREAD);
918 // Names are all known to be < 64k so we know this formatted message is not excessively large.
919 Exceptions::fthrow(THREAD_AND_LOCATION,
920 vmSymbols::java_lang_NoClassDefFoundError(),
921 "Class %s, or one of its supertypes, failed class initialization",
922 external_name());
923 return false;
924 }
925 // return if already verified
926 if (is_linked()) {
927 return true;
928 }
929
930 // Timing
931 // timer handles recursion
932 JavaThread* jt = THREAD;
933
934 // link super class before linking this class
935 Klass* super_klass = super();
936 if (super_klass != nullptr) {
937 if (super_klass->is_interface()) { // check if super class is an interface
938 ResourceMark rm(THREAD);
939 // Names are all known to be < 64k so we know this formatted message is not excessively large.
940 Exceptions::fthrow(
941 THREAD_AND_LOCATION,
942 vmSymbols::java_lang_IncompatibleClassChangeError(),
943 "class %s has interface %s as super class",
944 external_name(),
945 super_klass->external_name()
946 );
947 return false;
948 }
949
950 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
951 ik_super->link_class_impl(CHECK_false);
952 }
953
954 // link all interfaces implemented by this class before linking this class
955 Array<InstanceKlass*>* interfaces = local_interfaces();
956 int num_interfaces = interfaces->length();
957 for (int index = 0; index < num_interfaces; index++) {
958 InstanceKlass* interk = interfaces->at(index);
959 interk->link_class_impl(CHECK_false);
960 }
961
962 // in case the class is linked in the process of linking its superclasses
963 if (is_linked()) {
964 return true;
965 }
966
967 // trace only the link time for this klass that includes
968 // the verification time
969 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
970 ClassLoader::perf_class_link_selftime(),
971 ClassLoader::perf_classes_linked(),
972 jt->get_thread_stat()->perf_recursion_counts_addr(),
973 jt->get_thread_stat()->perf_timers_addr(),
974 PerfClassTraceTime::CLASS_LINK);
975
976 // verification & rewriting
977 {
978 HandleMark hm(THREAD);
979 Handle h_init_lock(THREAD, init_lock());
980 ObjectLocker ol(h_init_lock, jt);
981 // rewritten will have been set if loader constraint error found
982 // on an earlier link attempt
983 // don't verify or rewrite if already rewritten
984 //
985
986 if (!is_linked()) {
987 if (!is_rewritten()) {
988 if (is_shared()) {
989 assert(!verified_at_dump_time(), "must be");
990 }
991 {
992 bool verify_ok = verify_code(THREAD);
993 if (!verify_ok) {
994 return false;
995 }
996 }
997
998 // Just in case a side-effect of verify linked this class already
999 // (which can sometimes happen since the verifier loads classes
1000 // using custom class loaders, which are free to initialize things)
1001 if (is_linked()) {
1002 return true;
1003 }
1004
1005 // also sets rewritten
1006 rewrite_class(CHECK_false);
1007 } else if (is_shared()) {
1008 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1009 }
1010
1011 // relocate jsrs and link methods after they are all rewritten
1012 link_methods(CHECK_false);
1013
1014 // Initialize the vtable and interface table after
1015 // methods have been rewritten since rewrite may
1016 // fabricate new Method*s.
1017 // also does loader constraint checking
1018 //
1019 // initialize_vtable and initialize_itable need to be rerun
1020 // for a shared class if
1021 // 1) the class is loaded by custom class loader or
1022 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1023 // 3) the class was not verified during dump time
1024 bool need_init_table = true;
1025 if (is_shared() && verified_at_dump_time() &&
1026 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1027 need_init_table = false;
1028 }
1029 if (need_init_table) {
1030 vtable().initialize_vtable_and_check_constraints(CHECK_false);
1031 itable().initialize_itable_and_check_constraints(CHECK_false);
1032 }
1033 #ifdef ASSERT
1034 vtable().verify(tty, true);
1035 // In case itable verification is ever added.
1036 // itable().verify(tty, true);
1037 #endif
1038 if (Universe::is_fully_initialized()) {
1039 DeoptimizationScope deopt_scope;
1040 {
1041 // Now mark all code that assumes the class is not linked.
1042 // Set state under the Compile_lock also.
1043 MutexLocker ml(THREAD, Compile_lock);
1044
1045 set_init_state(linked);
1046 CodeCache::mark_dependents_on(&deopt_scope, this);
1047 }
1048 // Perform the deopt handshake outside Compile_lock.
1049 deopt_scope.deoptimize_marked();
1050 } else {
1051 set_init_state(linked);
1052 }
1053 if (JvmtiExport::should_post_class_prepare()) {
1054 JvmtiExport::post_class_prepare(THREAD, this);
1055 }
1056 }
1057 }
1058 return true;
1059 }
1060
1061 // Rewrite the byte codes of all of the methods of a class.
1062 // The rewriter must be called exactly once. Rewriting must happen after
1063 // verification but before the first method of the class is executed.
1064 void InstanceKlass::rewrite_class(TRAPS) {
1065 assert(is_loaded(), "must be loaded");
1066 if (is_rewritten()) {
1067 assert(is_shared(), "rewriting an unshared class?");
1068 return;
1069 }
1070 Rewriter::rewrite(this, CHECK);
1071 set_rewritten();
1072 }
1073
1074 // Now relocate and link method entry points after class is rewritten.
1075 // This is outside is_rewritten flag. In case of an exception, it can be
1076 // executed more than once.
1077 void InstanceKlass::link_methods(TRAPS) {
1078 PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1079
1080 int len = methods()->length();
1081 for (int i = len-1; i >= 0; i--) {
1082 methodHandle m(THREAD, methods()->at(i));
1083
1084 // Set up method entry points for compiler and interpreter .
1085 m->link_method(m, CHECK);
1086 }
1087 }
1088
1089 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1090 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1091 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1092 for (int i = 0; i < local_interfaces()->length(); ++i) {
1093 InstanceKlass* ik = local_interfaces()->at(i);
1094
1095 // Initialization is depth first search ie. we start with top of the inheritance tree
1096 // has_nonstatic_concrete_methods drives searching superinterfaces since it
1097 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1098 if (ik->has_nonstatic_concrete_methods()) {
1099 ik->initialize_super_interfaces(CHECK);
1100 }
1101
1102 // Only initialize() interfaces that "declare" concrete methods.
1103 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1104 ik->initialize(CHECK);
1105 }
1106 }
1107 }
1108
1109 using InitializationErrorTable = ResourceHashtable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1110 static InitializationErrorTable* _initialization_error_table;
1111
1112 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1113 // Create the same exception with a message indicating the thread name,
1114 // and the StackTraceElements.
1115 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1116 ResourceMark rm(current);
1117 if (init_error.is_null()) {
1118 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1119
1120 // We failed to create the new exception, most likely due to either out-of-memory or
1121 // a stackoverflow error. If the original exception was either of those then we save
1122 // the shared, pre-allocated, stackless, instance of that exception.
1123 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1124 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1125 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1126 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1127 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1128 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1129 } else {
1130 return;
1131 }
1132 }
1133
1134 MutexLocker ml(current, ClassInitError_lock);
1135 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1136 bool created;
1137 if (_initialization_error_table == nullptr) {
1138 _initialization_error_table = new (mtClass) InitializationErrorTable();
1139 }
1140 _initialization_error_table->put_if_absent(this, elem, &created);
1141 assert(created, "Initialization is single threaded");
1142 log_trace(class, init)("Initialization error added for class %s", external_name());
1143 }
1144
1145 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1146 MutexLocker ml(current, ClassInitError_lock);
1147 if (_initialization_error_table == nullptr) {
1148 return nullptr;
1149 }
1150 OopHandle* h = _initialization_error_table->get(this);
1151 return (h != nullptr) ? h->resolve() : nullptr;
1152 }
1153
1154 // Need to remove entries for unloaded classes.
1155 void InstanceKlass::clean_initialization_error_table() {
1156 struct InitErrorTableCleaner {
1157 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1158 if (!ik->is_loader_alive()) {
1159 h.release(Universe::vm_global());
1160 return true;
1161 } else {
1162 return false;
1163 }
1164 }
1165 };
1166
1167 assert_locked_or_safepoint(ClassInitError_lock);
1168 InitErrorTableCleaner cleaner;
1169 if (_initialization_error_table != nullptr) {
1170 _initialization_error_table->unlink(&cleaner);
1171 }
1172 }
1173
1174 void InstanceKlass::initialize_impl(TRAPS) {
1175 HandleMark hm(THREAD);
1176
1177 // Make sure klass is linked (verified) before initialization
1178 // A class could already be verified, since it has been reflected upon.
1179 link_class(CHECK);
1180
1181 DTRACE_CLASSINIT_PROBE(required, -1);
1182
1183 bool wait = false;
1184
1185 JavaThread* jt = THREAD;
1186
1187 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1188
1189 // refer to the JVM book page 47 for description of steps
1190 // Step 1
1191 {
1192 Handle h_init_lock(THREAD, init_lock());
1193 ObjectLocker ol(h_init_lock, jt);
1194
1195 // Step 2
1196 // If we were to use wait() instead of waitInterruptibly() then
1197 // we might end up throwing IE from link/symbol resolution sites
1198 // that aren't expected to throw. This would wreak havoc. See 6320309.
1199 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1200 if (debug_logging_enabled) {
1201 ResourceMark rm(jt);
1202 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1203 jt->name(), external_name(), init_thread_name());
1204 }
1205 wait = true;
1206 jt->set_class_to_be_initialized(this);
1207 ol.wait_uninterruptibly(jt);
1208 jt->set_class_to_be_initialized(nullptr);
1209 }
1210
1211 // Step 3
1212 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1213 if (debug_logging_enabled) {
1214 ResourceMark rm(jt);
1215 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1216 jt->name(), external_name());
1217 }
1218 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1219 return;
1220 }
1221
1222 // Step 4
1223 if (is_initialized()) {
1224 if (debug_logging_enabled) {
1225 ResourceMark rm(jt);
1226 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1227 jt->name(), external_name());
1228 }
1229 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1230 return;
1231 }
1232
1233 // Step 5
1234 if (is_in_error_state()) {
1235 if (debug_logging_enabled) {
1236 ResourceMark rm(jt);
1237 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1238 jt->name(), external_name());
1239 }
1240
1241 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1242 ResourceMark rm(THREAD);
1243 Handle cause(THREAD, get_initialization_error(THREAD));
1244
1245 stringStream ss;
1246 ss.print("Could not initialize class %s", external_name());
1247 if (cause.is_null()) {
1248 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1249 } else {
1250 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1251 ss.as_string(), cause);
1252 }
1253 } else {
1254
1255 // Step 6
1256 set_init_state(being_initialized);
1257 set_init_thread(jt);
1258 if (debug_logging_enabled) {
1259 ResourceMark rm(jt);
1260 log_debug(class, init)("Thread \"%s\" is initializing %s",
1261 jt->name(), external_name());
1262 }
1263 }
1264 }
1265
1266 // Step 7
1267 // Next, if C is a class rather than an interface, initialize it's super class and super
1268 // interfaces.
1269 if (!is_interface()) {
1270 Klass* super_klass = super();
1271 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1272 super_klass->initialize(THREAD);
1273 }
1274 // If C implements any interface that declares a non-static, concrete method,
1275 // the initialization of C triggers initialization of its super interfaces.
1276 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1277 // having a superinterface that declares, non-static, concrete methods
1278 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1279 initialize_super_interfaces(THREAD);
1280 }
1281
1282 // If any exceptions, complete abruptly, throwing the same exception as above.
1283 if (HAS_PENDING_EXCEPTION) {
1284 Handle e(THREAD, PENDING_EXCEPTION);
1285 CLEAR_PENDING_EXCEPTION;
1286 {
1287 EXCEPTION_MARK;
1288 add_initialization_error(THREAD, e);
1289 // Locks object, set state, and notify all waiting threads
1290 set_initialization_state_and_notify(initialization_error, THREAD);
1291 CLEAR_PENDING_EXCEPTION;
1292 }
1293 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1294 THROW_OOP(e());
1295 }
1296 }
1297
1298
1299 // Step 8
1300 {
1301 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1302 if (class_initializer() != nullptr) {
1303 // Timer includes any side effects of class initialization (resolution,
1304 // etc), but not recursive entry into call_class_initializer().
1305 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1306 ClassLoader::perf_class_init_selftime(),
1307 ClassLoader::perf_classes_inited(),
1308 jt->get_thread_stat()->perf_recursion_counts_addr(),
1309 jt->get_thread_stat()->perf_timers_addr(),
1310 PerfClassTraceTime::CLASS_CLINIT);
1311 call_class_initializer(THREAD);
1312 } else {
1313 // The elapsed time is so small it's not worth counting.
1314 if (UsePerfData) {
1315 ClassLoader::perf_classes_inited()->inc();
1316 }
1317 call_class_initializer(THREAD);
1318 }
1319 }
1320
1321 // Step 9
1322 if (!HAS_PENDING_EXCEPTION) {
1323 set_initialization_state_and_notify(fully_initialized, CHECK);
1324 debug_only(vtable().verify(tty, true);)
1325 }
1326 else {
1327 // Step 10 and 11
1328 Handle e(THREAD, PENDING_EXCEPTION);
1329 CLEAR_PENDING_EXCEPTION;
1330 // JVMTI has already reported the pending exception
1331 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1332 JvmtiExport::clear_detected_exception(jt);
1333 {
1334 EXCEPTION_MARK;
1335 add_initialization_error(THREAD, e);
1336 set_initialization_state_and_notify(initialization_error, THREAD);
1337 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1338 // JVMTI has already reported the pending exception
1339 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1340 JvmtiExport::clear_detected_exception(jt);
1341 }
1342 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1343 if (e->is_a(vmClasses::Error_klass())) {
1344 THROW_OOP(e());
1345 } else {
1346 JavaCallArguments args(e);
1347 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1348 vmSymbols::throwable_void_signature(),
1349 &args);
1350 }
1351 }
1352 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1353 }
1354
1355
1356 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1357 Handle h_init_lock(THREAD, init_lock());
1358 if (h_init_lock() != nullptr) {
1359 ObjectLocker ol(h_init_lock, THREAD);
1360 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1361 set_init_state(state);
1362 fence_and_clear_init_lock();
1363 ol.notify_all(CHECK);
1364 } else {
1365 assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1366 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1367 set_init_state(state);
1368 }
1369 }
1370
1371 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1372 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1373 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1374 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1375
1376 DeoptimizationScope deopt_scope;
1377 {
1378 MutexLocker ml(current, Compile_lock);
1379
1380 set_init_state(InstanceKlass::loaded);
1381 // make sure init_state store is already done.
1382 // The compiler reads the hierarchy outside of the Compile_lock.
1383 // Access ordering is used to add to hierarchy.
1384
1385 // Link into hierarchy.
1386 append_to_sibling_list(); // add to superklass/sibling list
1387 process_interfaces(); // handle all "implements" declarations
1388
1389 // Now mark all code that depended on old class hierarchy.
1390 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1391 if (Universe::is_fully_initialized()) {
1392 CodeCache::mark_dependents_on(&deopt_scope, this);
1393 }
1394 }
1395 // Perform the deopt handshake outside Compile_lock.
1396 deopt_scope.deoptimize_marked();
1397 }
1398
1399
1400 InstanceKlass* InstanceKlass::implementor() const {
1401 InstanceKlass* volatile* ik = adr_implementor();
1402 if (ik == nullptr) {
1403 return nullptr;
1404 } else {
1405 // This load races with inserts, and therefore needs acquire.
1406 InstanceKlass* ikls = Atomic::load_acquire(ik);
1407 if (ikls != nullptr && !ikls->is_loader_alive()) {
1408 return nullptr; // don't return unloaded class
1409 } else {
1410 return ikls;
1411 }
1412 }
1413 }
1414
1415
1416 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1417 assert_locked_or_safepoint(Compile_lock);
1418 assert(is_interface(), "not interface");
1419 InstanceKlass* volatile* addr = adr_implementor();
1420 assert(addr != nullptr, "null addr");
1421 if (addr != nullptr) {
1422 Atomic::release_store(addr, ik);
1423 }
1424 }
1425
1426 int InstanceKlass::nof_implementors() const {
1427 InstanceKlass* ik = implementor();
1428 if (ik == nullptr) {
1429 return 0;
1430 } else if (ik != this) {
1431 return 1;
1432 } else {
1433 return 2;
1434 }
1435 }
1436
1437 // The embedded _implementor field can only record one implementor.
1438 // When there are more than one implementors, the _implementor field
1439 // is set to the interface Klass* itself. Following are the possible
1440 // values for the _implementor field:
1441 // null - no implementor
1442 // implementor Klass* - one implementor
1443 // self - more than one implementor
1444 //
1445 // The _implementor field only exists for interfaces.
1446 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1447 if (Universe::is_fully_initialized()) {
1448 assert_lock_strong(Compile_lock);
1449 }
1450 assert(is_interface(), "not interface");
1451 // Filter out my subinterfaces.
1452 // (Note: Interfaces are never on the subklass list.)
1453 if (ik->is_interface()) return;
1454
1455 // Filter out subclasses whose supers already implement me.
1456 // (Note: CHA must walk subclasses of direct implementors
1457 // in order to locate indirect implementors.)
1458 InstanceKlass* super_ik = ik->java_super();
1459 if (super_ik != nullptr && super_ik->implements_interface(this))
1460 // We only need to check one immediate superclass, since the
1461 // implements_interface query looks at transitive_interfaces.
1462 // Any supers of the super have the same (or fewer) transitive_interfaces.
1463 return;
1464
1465 InstanceKlass* iklass = implementor();
1466 if (iklass == nullptr) {
1467 set_implementor(ik);
1468 } else if (iklass != this && iklass != ik) {
1469 // There is already an implementor. Use itself as an indicator of
1470 // more than one implementors.
1471 set_implementor(this);
1472 }
1473
1474 // The implementor also implements the transitive_interfaces
1475 for (int index = 0; index < local_interfaces()->length(); index++) {
1476 local_interfaces()->at(index)->add_implementor(ik);
1477 }
1478 }
1479
1480 void InstanceKlass::init_implementor() {
1481 if (is_interface()) {
1482 set_implementor(nullptr);
1483 }
1484 }
1485
1486
1487 void InstanceKlass::process_interfaces() {
1488 // link this class into the implementors list of every interface it implements
1489 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1490 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1491 InstanceKlass* interf = local_interfaces()->at(i);
1492 assert(interf->is_interface(), "expected interface");
1493 interf->add_implementor(this);
1494 }
1495 }
1496
1497 bool InstanceKlass::can_be_primary_super_slow() const {
1498 if (is_interface())
1499 return false;
1500 else
1501 return Klass::can_be_primary_super_slow();
1502 }
1503
1504 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1505 Array<InstanceKlass*>* transitive_interfaces) {
1506 // The secondaries are the implemented interfaces.
1507 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1508 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1509 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1510 int num_secondaries = num_extra_slots + interfaces->length();
1511 if (num_secondaries == 0) {
1512 // Must share this for correct bootstrapping!
1513 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1514 return nullptr;
1515 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1516 // We will reuse the transitive interfaces list if we're certain
1517 // it's in hash order.
1518 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1519 set_secondary_supers(interfaces, bitmap);
1520 return nullptr;
1521 }
1522 // Copy transitive interfaces to a temporary growable array to be constructed
1523 // into the secondary super list with extra slots.
1524 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1525 for (int i = 0; i < interfaces->length(); i++) {
1526 secondaries->push(interfaces->at(i));
1527 }
1528 return secondaries;
1529 }
1530
1531 bool InstanceKlass::implements_interface(Klass* k) const {
1532 if (this == k) return true;
1533 assert(k->is_interface(), "should be an interface class");
1534 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1535 if (transitive_interfaces()->at(i) == k) {
1536 return true;
1537 }
1538 }
1539 return false;
1540 }
1541
1542 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1543 // Verify direct super interface
1544 if (this == k) return true;
1545 assert(k->is_interface(), "should be an interface class");
1546 for (int i = 0; i < local_interfaces()->length(); i++) {
1547 if (local_interfaces()->at(i) == k) {
1548 return true;
1549 }
1550 }
1551 return false;
1552 }
1553
1554 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1555 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1556 size_t size = objArrayOopDesc::object_size(length);
1557 ArrayKlass* ak = array_klass(n, CHECK_NULL);
1558 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1559 /* do_zero */ true, CHECK_NULL);
1560 return o;
1561 }
1562
1563 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1564 if (TraceFinalizerRegistration) {
1565 tty->print("Registered ");
1566 i->print_value_on(tty);
1567 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1568 }
1569 instanceHandle h_i(THREAD, i);
1570 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1571 JavaValue result(T_VOID);
1572 JavaCallArguments args(h_i);
1573 methodHandle mh(THREAD, Universe::finalizer_register_method());
1574 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1575 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1576 return h_i();
1577 }
1578
1579 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1580 assert(!is_abstract() && !is_interface(), "Should not create this object");
1581 size_t size = size_helper(); // Query before forming handle.
1582 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1583 }
1584
1585 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1586 Klass* k = java_lang_Class::as_Klass(java_class);
1587 if (k == nullptr) {
1588 ResourceMark rm(THREAD);
1589 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1590 }
1591 InstanceKlass* ik = cast(k);
1592 ik->check_valid_for_instantiation(false, CHECK_NULL);
1593 ik->initialize(CHECK_NULL);
1594 return ik->allocate_instance(THREAD);
1595 }
1596
1597 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1598 return instanceHandle(THREAD, allocate_instance(THREAD));
1599 }
1600
1601 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1602 if (is_interface() || is_abstract()) {
1603 ResourceMark rm(THREAD);
1604 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1605 : vmSymbols::java_lang_InstantiationException(), external_name());
1606 }
1607 if (this == vmClasses::Class_klass()) {
1608 ResourceMark rm(THREAD);
1609 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1610 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1611 }
1612 }
1613
1614 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1615 // Need load-acquire for lock-free read
1616 if (array_klasses_acquire() == nullptr) {
1617
1618 // Recursively lock array allocation
1619 RecursiveLocker rl(MultiArray_lock, THREAD);
1620
1621 // Check if another thread created the array klass while we were waiting for the lock.
1622 if (array_klasses() == nullptr) {
1623 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1624 // use 'release' to pair with lock-free load
1625 release_set_array_klasses(k);
1626 }
1627 }
1628
1629 // array_klasses() will always be set at this point
1630 ObjArrayKlass* ak = array_klasses();
1631 assert(ak != nullptr, "should be set");
1632 return ak->array_klass(n, THREAD);
1633 }
1634
1635 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1636 // Need load-acquire for lock-free read
1637 ObjArrayKlass* oak = array_klasses_acquire();
1638 if (oak == nullptr) {
1639 return nullptr;
1640 } else {
1641 return oak->array_klass_or_null(n);
1642 }
1643 }
1644
1645 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1646 return array_klass(1, THREAD);
1647 }
1648
1649 ArrayKlass* InstanceKlass::array_klass_or_null() {
1650 return array_klass_or_null(1);
1651 }
1652
1653 static int call_class_initializer_counter = 0; // for debugging
1654
1655 Method* InstanceKlass::class_initializer() const {
1656 Method* clinit = find_method(
1657 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1658 if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1659 return clinit;
1660 }
1661 return nullptr;
1662 }
1663
1664 void InstanceKlass::call_class_initializer(TRAPS) {
1665 if (ReplayCompiles &&
1666 (ReplaySuppressInitializers == 1 ||
1667 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1668 // Hide the existence of the initializer for the purpose of replaying the compile
1669 return;
1670 }
1671
1672 #if INCLUDE_CDS
1673 // This is needed to ensure the consistency of the archived heap objects.
1674 if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
1675 AOTClassInitializer::call_runtime_setup(THREAD, this);
1676 return;
1677 } else if (has_archived_enum_objs()) {
1678 assert(is_shared(), "must be");
1679 bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1680 if (initialized) {
1681 return;
1682 }
1683 }
1684 #endif
1685
1686 methodHandle h_method(THREAD, class_initializer());
1687 assert(!is_initialized(), "we cannot initialize twice");
1688 LogTarget(Info, class, init) lt;
1689 if (lt.is_enabled()) {
1690 ResourceMark rm(THREAD);
1691 LogStream ls(lt);
1692 ls.print("%d Initializing ", call_class_initializer_counter++);
1693 name()->print_value_on(&ls);
1694 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1695 h_method() == nullptr ? "(no method)" : "", p2i(this),
1696 THREAD->name());
1697 }
1698 if (h_method() != nullptr) {
1699 ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
1700 JavaCallArguments args; // No arguments
1701 JavaValue result(T_VOID);
1702 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1703 }
1704 }
1705
1706 // If a class that implements this interface is initialized, is the JVM required
1707 // to first execute a <clinit> method declared in this interface,
1708 // or (if also_check_supers==true) any of the super types of this interface?
1709 //
1710 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
1711 // an interface, then let SC be its superclass and let SI1, ..., SIn
1712 // be all superinterfaces of C (whether direct or indirect) that
1713 // declare at least one non-abstract, non-static method.
1714 //
1715 // So when an interface is initialized, it does not look at its
1716 // supers. But a proper class will ensure that all of its supers have
1717 // run their <clinit> methods, except that it disregards interfaces
1718 // that lack a non-static concrete method (i.e., a default method).
1719 // Therefore, you should probably call this method only when the
1720 // current class is a super of some proper class, not an interface.
1721 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
1722 assert(is_interface(), "must be");
1723
1724 if (!has_nonstatic_concrete_methods()) {
1725 // quick check: no nonstatic concrete methods are declared by this or any super interfaces
1726 return false;
1727 }
1728
1729 // JVMS 5.5. Initialization
1730 // ...If C is an interface that declares a non-abstract,
1731 // non-static method, the initialization of a class that
1732 // implements C directly or indirectly.
1733 if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
1734 return true;
1735 }
1736 if (also_check_supers) {
1737 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1738 for (int i = 0; i < all_ifs->length(); ++i) {
1739 InstanceKlass* super_intf = all_ifs->at(i);
1740 if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
1741 return true;
1742 }
1743 }
1744 }
1745 return false;
1746 }
1747
1748 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1749 InterpreterOopMap* entry_for) {
1750 // Lazily create the _oop_map_cache at first request.
1751 // Load_acquire is needed to safely get instance published with CAS by another thread.
1752 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1753 if (oop_map_cache == nullptr) {
1754 // Try to install new instance atomically.
1755 oop_map_cache = new OopMapCache();
1756 OopMapCache* other = Atomic::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
1757 if (other != nullptr) {
1758 // Someone else managed to install before us, ditch local copy and use the existing one.
1759 delete oop_map_cache;
1760 oop_map_cache = other;
1761 }
1762 }
1763 // _oop_map_cache is constant after init; lookup below does its own locking.
1764 oop_map_cache->lookup(method, bci, entry_for);
1765 }
1766
1767 bool InstanceKlass::contains_field_offset(int offset) {
1768 fieldDescriptor fd;
1769 return find_field_from_offset(offset, false, &fd);
1770 }
1771
1772 FieldInfo InstanceKlass::field(int index) const {
1773 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1774 if (fs.index() == index) {
1775 return fs.to_FieldInfo();
1776 }
1777 }
1778 fatal("Field not found");
1779 return FieldInfo();
1780 }
1781
1782 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1783 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1784 Symbol* f_name = fs.name();
1785 Symbol* f_sig = fs.signature();
1786 if (f_name == name && f_sig == sig) {
1787 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1788 return true;
1789 }
1790 }
1791 return false;
1792 }
1793
1794
1795 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1796 const int n = local_interfaces()->length();
1797 for (int i = 0; i < n; i++) {
1798 Klass* intf1 = local_interfaces()->at(i);
1799 assert(intf1->is_interface(), "just checking type");
1800 // search for field in current interface
1801 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1802 assert(fd->is_static(), "interface field must be static");
1803 return intf1;
1804 }
1805 // search for field in direct superinterfaces
1806 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1807 if (intf2 != nullptr) return intf2;
1808 }
1809 // otherwise field lookup fails
1810 return nullptr;
1811 }
1812
1813
1814 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1815 // search order according to newest JVM spec (5.4.3.2, p.167).
1816 // 1) search for field in current klass
1817 if (find_local_field(name, sig, fd)) {
1818 return const_cast<InstanceKlass*>(this);
1819 }
1820 // 2) search for field recursively in direct superinterfaces
1821 { Klass* intf = find_interface_field(name, sig, fd);
1822 if (intf != nullptr) return intf;
1823 }
1824 // 3) apply field lookup recursively if superclass exists
1825 { Klass* supr = super();
1826 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1827 }
1828 // 4) otherwise field lookup fails
1829 return nullptr;
1830 }
1831
1832
1833 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1834 // search order according to newest JVM spec (5.4.3.2, p.167).
1835 // 1) search for field in current klass
1836 if (find_local_field(name, sig, fd)) {
1837 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1838 }
1839 // 2) search for field recursively in direct superinterfaces
1840 if (is_static) {
1841 Klass* intf = find_interface_field(name, sig, fd);
1842 if (intf != nullptr) return intf;
1843 }
1844 // 3) apply field lookup recursively if superclass exists
1845 { Klass* supr = super();
1846 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1847 }
1848 // 4) otherwise field lookup fails
1849 return nullptr;
1850 }
1851
1852
1853 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1854 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1855 if (fs.offset() == offset) {
1856 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1857 if (fd->is_static() == is_static) return true;
1858 }
1859 }
1860 return false;
1861 }
1862
1863
1864 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1865 Klass* klass = const_cast<InstanceKlass*>(this);
1866 while (klass != nullptr) {
1867 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1868 return true;
1869 }
1870 klass = klass->super();
1871 }
1872 return false;
1873 }
1874
1875
1876 void InstanceKlass::methods_do(void f(Method* method)) {
1877 // Methods aren't stable until they are loaded. This can be read outside
1878 // a lock through the ClassLoaderData for profiling
1879 // Redefined scratch classes are on the list and need to be cleaned
1880 if (!is_loaded() && !is_scratch_class()) {
1881 return;
1882 }
1883
1884 int len = methods()->length();
1885 for (int index = 0; index < len; index++) {
1886 Method* m = methods()->at(index);
1887 assert(m->is_method(), "must be method");
1888 f(m);
1889 }
1890 }
1891
1892
1893 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1894 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1895 if (fs.access_flags().is_static()) {
1896 fieldDescriptor& fd = fs.field_descriptor();
1897 cl->do_field(&fd);
1898 }
1899 }
1900 }
1901
1902
1903 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1904 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1905 if (fs.access_flags().is_static()) {
1906 fieldDescriptor& fd = fs.field_descriptor();
1907 f(&fd, mirror, CHECK);
1908 }
1909 }
1910 }
1911
1912 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1913 InstanceKlass* super = superklass();
1914 if (super != nullptr) {
1915 super->do_nonstatic_fields(cl);
1916 }
1917 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1918 fieldDescriptor& fd = fs.field_descriptor();
1919 if (!fd.is_static()) {
1920 cl->do_field(&fd);
1921 }
1922 }
1923 }
1924
1925 static int compare_fields_by_offset(FieldInfo* a, FieldInfo* b) {
1926 return a->offset() - b->offset();
1927 }
1928
1929 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1930 InstanceKlass* super = superklass();
1931 if (super != nullptr) {
1932 super->print_nonstatic_fields(cl);
1933 }
1934 ResourceMark rm;
1935 // In DebugInfo nonstatic fields are sorted by offset.
1936 GrowableArray<FieldInfo> fields_sorted;
1937 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1938 if (!fs.access_flags().is_static()) {
1939 fields_sorted.push(fs.to_FieldInfo());
1940 }
1941 }
1942 int length = fields_sorted.length();
1943 if (length > 0) {
1944 fields_sorted.sort(compare_fields_by_offset);
1945 fieldDescriptor fd;
1946 for (int i = 0; i < length; i++) {
1947 fd.reinitialize(this, fields_sorted.at(i));
1948 assert(!fd.is_static() && fd.offset() == checked_cast<int>(fields_sorted.at(i).offset()), "only nonstatic fields");
1949 cl->do_field(&fd);
1950 }
1951 }
1952 }
1953
1954 #ifdef ASSERT
1955 static int linear_search(const Array<Method*>* methods,
1956 const Symbol* name,
1957 const Symbol* signature) {
1958 const int len = methods->length();
1959 for (int index = 0; index < len; index++) {
1960 const Method* const m = methods->at(index);
1961 assert(m->is_method(), "must be method");
1962 if (m->signature() == signature && m->name() == name) {
1963 return index;
1964 }
1965 }
1966 return -1;
1967 }
1968 #endif
1969
1970 bool InstanceKlass::_disable_method_binary_search = false;
1971
1972 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1973 int len = methods->length();
1974 int l = 0;
1975 int h = len - 1;
1976 while (l <= h) {
1977 Method* m = methods->at(l);
1978 if (m->name() == name) {
1979 return l;
1980 }
1981 l++;
1982 }
1983 return -1;
1984 }
1985
1986 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1987 if (_disable_method_binary_search) {
1988 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1989 // At the final stage of dynamic dumping, the methods array may not be sorted
1990 // by ascending addresses of their names, so we can't use binary search anymore.
1991 // However, methods with the same name are still laid out consecutively inside the
1992 // methods array, so let's look for the first one that matches.
1993 return linear_search(methods, name);
1994 }
1995
1996 int len = methods->length();
1997 int l = 0;
1998 int h = len - 1;
1999
2000 // methods are sorted by ascending addresses of their names, so do binary search
2001 while (l <= h) {
2002 int mid = (l + h) >> 1;
2003 Method* m = methods->at(mid);
2004 assert(m->is_method(), "must be method");
2005 int res = m->name()->fast_compare(name);
2006 if (res == 0) {
2007 return mid;
2008 } else if (res < 0) {
2009 l = mid + 1;
2010 } else {
2011 h = mid - 1;
2012 }
2013 }
2014 return -1;
2015 }
2016
2017 // find_method looks up the name/signature in the local methods array
2018 Method* InstanceKlass::find_method(const Symbol* name,
2019 const Symbol* signature) const {
2020 return find_method_impl(name, signature,
2021 OverpassLookupMode::find,
2022 StaticLookupMode::find,
2023 PrivateLookupMode::find);
2024 }
2025
2026 Method* InstanceKlass::find_method_impl(const Symbol* name,
2027 const Symbol* signature,
2028 OverpassLookupMode overpass_mode,
2029 StaticLookupMode static_mode,
2030 PrivateLookupMode private_mode) const {
2031 return InstanceKlass::find_method_impl(methods(),
2032 name,
2033 signature,
2034 overpass_mode,
2035 static_mode,
2036 private_mode);
2037 }
2038
2039 // find_instance_method looks up the name/signature in the local methods array
2040 // and skips over static methods
2041 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2042 const Symbol* name,
2043 const Symbol* signature,
2044 PrivateLookupMode private_mode) {
2045 Method* const meth = InstanceKlass::find_method_impl(methods,
2046 name,
2047 signature,
2048 OverpassLookupMode::find,
2049 StaticLookupMode::skip,
2050 private_mode);
2051 assert(((meth == nullptr) || !meth->is_static()),
2052 "find_instance_method should have skipped statics");
2053 return meth;
2054 }
2055
2056 // find_instance_method looks up the name/signature in the local methods array
2057 // and skips over static methods
2058 Method* InstanceKlass::find_instance_method(const Symbol* name,
2059 const Symbol* signature,
2060 PrivateLookupMode private_mode) const {
2061 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2062 }
2063
2064 // Find looks up the name/signature in the local methods array
2065 // and filters on the overpass, static and private flags
2066 // This returns the first one found
2067 // note that the local methods array can have up to one overpass, one static
2068 // and one instance (private or not) with the same name/signature
2069 Method* InstanceKlass::find_local_method(const Symbol* name,
2070 const Symbol* signature,
2071 OverpassLookupMode overpass_mode,
2072 StaticLookupMode static_mode,
2073 PrivateLookupMode private_mode) const {
2074 return InstanceKlass::find_method_impl(methods(),
2075 name,
2076 signature,
2077 overpass_mode,
2078 static_mode,
2079 private_mode);
2080 }
2081
2082 // Find looks up the name/signature in the local methods array
2083 // and filters on the overpass, static and private flags
2084 // This returns the first one found
2085 // note that the local methods array can have up to one overpass, one static
2086 // and one instance (private or not) with the same name/signature
2087 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2088 const Symbol* name,
2089 const Symbol* signature,
2090 OverpassLookupMode overpass_mode,
2091 StaticLookupMode static_mode,
2092 PrivateLookupMode private_mode) {
2093 return InstanceKlass::find_method_impl(methods,
2094 name,
2095 signature,
2096 overpass_mode,
2097 static_mode,
2098 private_mode);
2099 }
2100
2101 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2102 const Symbol* name,
2103 const Symbol* signature) {
2104 return InstanceKlass::find_method_impl(methods,
2105 name,
2106 signature,
2107 OverpassLookupMode::find,
2108 StaticLookupMode::find,
2109 PrivateLookupMode::find);
2110 }
2111
2112 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2113 const Symbol* name,
2114 const Symbol* signature,
2115 OverpassLookupMode overpass_mode,
2116 StaticLookupMode static_mode,
2117 PrivateLookupMode private_mode) {
2118 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2119 return hit >= 0 ? methods->at(hit): nullptr;
2120 }
2121
2122 // true if method matches signature and conforms to skipping_X conditions.
2123 static bool method_matches(const Method* m,
2124 const Symbol* signature,
2125 bool skipping_overpass,
2126 bool skipping_static,
2127 bool skipping_private) {
2128 return ((m->signature() == signature) &&
2129 (!skipping_overpass || !m->is_overpass()) &&
2130 (!skipping_static || !m->is_static()) &&
2131 (!skipping_private || !m->is_private()));
2132 }
2133
2134 // Used directly for default_methods to find the index into the
2135 // default_vtable_indices, and indirectly by find_method
2136 // find_method_index looks in the local methods array to return the index
2137 // of the matching name/signature. If, overpass methods are being ignored,
2138 // the search continues to find a potential non-overpass match. This capability
2139 // is important during method resolution to prefer a static method, for example,
2140 // over an overpass method.
2141 // There is the possibility in any _method's array to have the same name/signature
2142 // for a static method, an overpass method and a local instance method
2143 // To correctly catch a given method, the search criteria may need
2144 // to explicitly skip the other two. For local instance methods, it
2145 // is often necessary to skip private methods
2146 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2147 const Symbol* name,
2148 const Symbol* signature,
2149 OverpassLookupMode overpass_mode,
2150 StaticLookupMode static_mode,
2151 PrivateLookupMode private_mode) {
2152 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2153 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2154 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2155 const int hit = quick_search(methods, name);
2156 if (hit != -1) {
2157 const Method* const m = methods->at(hit);
2158
2159 // Do linear search to find matching signature. First, quick check
2160 // for common case, ignoring overpasses if requested.
2161 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2162 return hit;
2163 }
2164
2165 // search downwards through overloaded methods
2166 int i;
2167 for (i = hit - 1; i >= 0; --i) {
2168 const Method* const m = methods->at(i);
2169 assert(m->is_method(), "must be method");
2170 if (m->name() != name) {
2171 break;
2172 }
2173 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2174 return i;
2175 }
2176 }
2177 // search upwards
2178 for (i = hit + 1; i < methods->length(); ++i) {
2179 const Method* const m = methods->at(i);
2180 assert(m->is_method(), "must be method");
2181 if (m->name() != name) {
2182 break;
2183 }
2184 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2185 return i;
2186 }
2187 }
2188 // not found
2189 #ifdef ASSERT
2190 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2191 linear_search(methods, name, signature);
2192 assert(-1 == index, "binary search should have found entry %d", index);
2193 #endif
2194 }
2195 return -1;
2196 }
2197
2198 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2199 return find_method_by_name(methods(), name, end);
2200 }
2201
2202 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2203 const Symbol* name,
2204 int* end_ptr) {
2205 assert(end_ptr != nullptr, "just checking");
2206 int start = quick_search(methods, name);
2207 int end = start + 1;
2208 if (start != -1) {
2209 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2210 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2211 *end_ptr = end;
2212 return start;
2213 }
2214 return -1;
2215 }
2216
2217 // uncached_lookup_method searches both the local class methods array and all
2218 // superclasses methods arrays, skipping any overpass methods in superclasses,
2219 // and possibly skipping private methods.
2220 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2221 const Symbol* signature,
2222 OverpassLookupMode overpass_mode,
2223 PrivateLookupMode private_mode) const {
2224 OverpassLookupMode overpass_local_mode = overpass_mode;
2225 const Klass* klass = this;
2226 while (klass != nullptr) {
2227 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
2228 signature,
2229 overpass_local_mode,
2230 StaticLookupMode::find,
2231 private_mode);
2232 if (method != nullptr) {
2233 return method;
2234 }
2235 klass = klass->super();
2236 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2237 }
2238 return nullptr;
2239 }
2240
2241 #ifdef ASSERT
2242 // search through class hierarchy and return true if this class or
2243 // one of the superclasses was redefined
2244 bool InstanceKlass::has_redefined_this_or_super() const {
2245 const Klass* klass = this;
2246 while (klass != nullptr) {
2247 if (InstanceKlass::cast(klass)->has_been_redefined()) {
2248 return true;
2249 }
2250 klass = klass->super();
2251 }
2252 return false;
2253 }
2254 #endif
2255
2256 // lookup a method in the default methods list then in all transitive interfaces
2257 // Do NOT return private or static methods
2258 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2259 Symbol* signature) const {
2260 Method* m = nullptr;
2261 if (default_methods() != nullptr) {
2262 m = find_method(default_methods(), name, signature);
2263 }
2264 // Look up interfaces
2265 if (m == nullptr) {
2266 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2267 }
2268 return m;
2269 }
2270
2271 // lookup a method in all the interfaces that this class implements
2272 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2273 // They should only be found in the initial InterfaceMethodRef
2274 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2275 Symbol* signature,
2276 DefaultsLookupMode defaults_mode) const {
2277 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2278 int num_ifs = all_ifs->length();
2279 InstanceKlass *ik = nullptr;
2280 for (int i = 0; i < num_ifs; i++) {
2281 ik = all_ifs->at(i);
2282 Method* m = ik->lookup_method(name, signature);
2283 if (m != nullptr && m->is_public() && !m->is_static() &&
2284 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2285 return m;
2286 }
2287 }
2288 return nullptr;
2289 }
2290
2291 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2292 :_st(st), _verbose(verbose) {
2293 ResourceMark rm;
2294 _st->print("%-18s ", "KlassAddr");
2295 _st->print("%-4s ", "Size");
2296 _st->print("%-20s ", "State");
2297 _st->print("%-7s ", "Flags");
2298 _st->print("%-5s ", "ClassName");
2299 _st->cr();
2300 }
2301
2302 void PrintClassClosure::do_klass(Klass* k) {
2303 ResourceMark rm;
2304 // klass pointer
2305 _st->print(PTR_FORMAT " ", p2i(k));
2306 // klass size
2307 _st->print("%4d ", k->size());
2308 // initialization state
2309 if (k->is_instance_klass()) {
2310 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2311 } else {
2312 _st->print("%-20s ","");
2313 }
2314 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2315 char buf[10];
2316 int i = 0;
2317 if (k->has_finalizer()) buf[i++] = 'F';
2318 if (k->is_instance_klass()) {
2319 InstanceKlass* ik = InstanceKlass::cast(k);
2320 if (ik->has_final_method()) buf[i++] = 'f';
2321 if (ik->is_rewritten()) buf[i++] = 'W';
2322 if (ik->is_contended()) buf[i++] = 'C';
2323 if (ik->has_been_redefined()) buf[i++] = 'R';
2324 if (ik->is_shared()) buf[i++] = 'S';
2325 }
2326 buf[i++] = '\0';
2327 _st->print("%-7s ", buf);
2328 // klass name
2329 _st->print("%-5s ", k->external_name());
2330 // end
2331 _st->cr();
2332 if (_verbose) {
2333 k->print_on(_st);
2334 }
2335 }
2336
2337 /* jni_id_for for jfieldIds only */
2338 JNIid* InstanceKlass::jni_id_for(int offset) {
2339 MutexLocker ml(JfieldIdCreation_lock);
2340 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2341 if (probe == nullptr) {
2342 // Allocate new static field identifier
2343 probe = new JNIid(this, offset, jni_ids());
2344 set_jni_ids(probe);
2345 }
2346 return probe;
2347 }
2348
2349 u2 InstanceKlass::enclosing_method_data(int offset) const {
2350 const Array<jushort>* const inner_class_list = inner_classes();
2351 if (inner_class_list == nullptr) {
2352 return 0;
2353 }
2354 const int length = inner_class_list->length();
2355 if (length % inner_class_next_offset == 0) {
2356 return 0;
2357 }
2358 const int index = length - enclosing_method_attribute_size;
2359 assert(offset < enclosing_method_attribute_size, "invalid offset");
2360 return inner_class_list->at(index + offset);
2361 }
2362
2363 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2364 u2 method_index) {
2365 Array<jushort>* inner_class_list = inner_classes();
2366 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2367 int length = inner_class_list->length();
2368 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2369 int index = length - enclosing_method_attribute_size;
2370 inner_class_list->at_put(
2371 index + enclosing_method_class_index_offset, class_index);
2372 inner_class_list->at_put(
2373 index + enclosing_method_method_index_offset, method_index);
2374 }
2375 }
2376
2377 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2378 if (method->is_old() && !method->is_obsolete()) {
2379 // If the method passed in is old (but not obsolete), use the current version.
2380 method = method_with_idnum((int)idnum);
2381 assert(method != nullptr, "old and but not obsolete, so should exist");
2382 }
2383 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2384 Atomic::release_store(&jmeths[idnum + 1], new_id);
2385 return new_id;
2386 }
2387
2388 // Lookup or create a jmethodID.
2389 // This code is called by the VMThread and JavaThreads so the
2390 // locking has to be done very carefully to avoid deadlocks
2391 // and/or other cache consistency problems.
2392 //
2393 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2394 Method* method = method_h();
2395 int idnum = method->method_idnum();
2396 jmethodID* jmeths = methods_jmethod_ids_acquire();
2397
2398 // We use a double-check locking idiom here because this cache is
2399 // performance sensitive. In the normal system, this cache only
2400 // transitions from null to non-null which is safe because we use
2401 // release_set_methods_jmethod_ids() to advertise the new cache.
2402 // A partially constructed cache should never be seen by a racing
2403 // thread. We also use release_store() to save a new jmethodID
2404 // in the cache so a partially constructed jmethodID should never be
2405 // seen either. Cache reads of existing jmethodIDs proceed without a
2406 // lock, but cache writes of a new jmethodID requires uniqueness and
2407 // creation of the cache itself requires no leaks so a lock is
2408 // acquired in those two cases.
2409 //
2410 // If the RedefineClasses() API has been used, then this cache grows
2411 // in the redefinition safepoint.
2412
2413 if (jmeths == nullptr) {
2414 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2415 jmeths = methods_jmethod_ids_acquire();
2416 // Still null?
2417 if (jmeths == nullptr) {
2418 size_t size = idnum_allocated_count();
2419 assert(size > (size_t)idnum, "should already have space");
2420 jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2421 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2422 // cache size is stored in element[0], other elements offset by one
2423 jmeths[0] = (jmethodID)size;
2424 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2425
2426 // publish jmeths
2427 release_set_methods_jmethod_ids(jmeths);
2428 return new_id;
2429 }
2430 }
2431
2432 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2433 if (id == nullptr) {
2434 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2435 id = jmeths[idnum + 1];
2436 // Still null?
2437 if (id == nullptr) {
2438 return update_jmethod_id(jmeths, method, idnum);
2439 }
2440 }
2441 return id;
2442 }
2443
2444 void InstanceKlass::update_methods_jmethod_cache() {
2445 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2446 jmethodID* cache = _methods_jmethod_ids;
2447 if (cache != nullptr) {
2448 size_t size = idnum_allocated_count();
2449 size_t old_size = (size_t)cache[0];
2450 if (old_size < size + 1) {
2451 // Allocate a larger one and copy entries to the new one.
2452 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2453 jmethodID* new_cache = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2454 memset(new_cache, 0, (size + 1) * sizeof(jmethodID));
2455 // The cache size is stored in element[0]; the other elements are offset by one.
2456 new_cache[0] = (jmethodID)size;
2457
2458 for (int i = 1; i <= (int)old_size; i++) {
2459 new_cache[i] = cache[i];
2460 }
2461 _methods_jmethod_ids = new_cache;
2462 FREE_C_HEAP_ARRAY(jmethodID, cache);
2463 }
2464 }
2465 }
2466
2467 // Figure out how many jmethodIDs haven't been allocated, and make
2468 // sure space for them is pre-allocated. This makes getting all
2469 // method ids much, much faster with classes with more than 8
2470 // methods, and has a *substantial* effect on performance with jvmti
2471 // code that loads all jmethodIDs for all classes.
2472 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2473 int new_jmeths = 0;
2474 int length = methods()->length();
2475 for (int index = start_offset; index < length; index++) {
2476 Method* m = methods()->at(index);
2477 jmethodID id = m->find_jmethod_id_or_null();
2478 if (id == nullptr) {
2479 new_jmeths++;
2480 }
2481 }
2482 if (new_jmeths != 0) {
2483 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2484 }
2485 }
2486
2487 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2488 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2489 int idnum = method->method_idnum();
2490 jmethodID* jmeths = methods_jmethod_ids_acquire();
2491 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2492 }
2493
2494 inline DependencyContext InstanceKlass::dependencies() {
2495 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2496 return dep_context;
2497 }
2498
2499 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2500 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2501 }
2502
2503 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2504 dependencies().add_dependent_nmethod(nm);
2505 }
2506
2507 void InstanceKlass::clean_dependency_context() {
2508 dependencies().clean_unloading_dependents();
2509 }
2510
2511 #ifndef PRODUCT
2512 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2513 dependencies().print_dependent_nmethods(verbose);
2514 }
2515
2516 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2517 return dependencies().is_dependent_nmethod(nm);
2518 }
2519 #endif //PRODUCT
2520
2521 void InstanceKlass::clean_weak_instanceklass_links() {
2522 clean_implementors_list();
2523 clean_method_data();
2524 }
2525
2526 void InstanceKlass::clean_implementors_list() {
2527 assert(is_loader_alive(), "this klass should be live");
2528 if (is_interface()) {
2529 assert (ClassUnloading, "only called for ClassUnloading");
2530 for (;;) {
2531 // Use load_acquire due to competing with inserts
2532 InstanceKlass* volatile* iklass = adr_implementor();
2533 assert(iklass != nullptr, "Klass must not be null");
2534 InstanceKlass* impl = Atomic::load_acquire(iklass);
2535 if (impl != nullptr && !impl->is_loader_alive()) {
2536 // null this field, might be an unloaded instance klass or null
2537 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2538 // Successfully unlinking implementor.
2539 if (log_is_enabled(Trace, class, unload)) {
2540 ResourceMark rm;
2541 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2542 }
2543 return;
2544 }
2545 } else {
2546 return;
2547 }
2548 }
2549 }
2550 }
2551
2552 void InstanceKlass::clean_method_data() {
2553 for (int m = 0; m < methods()->length(); m++) {
2554 MethodData* mdo = methods()->at(m)->method_data();
2555 if (mdo != nullptr) {
2556 mdo->clean_method_data(/*always_clean*/false);
2557 }
2558 }
2559 }
2560
2561 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2562 Klass::metaspace_pointers_do(it);
2563
2564 if (log_is_enabled(Trace, cds)) {
2565 ResourceMark rm;
2566 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2567 }
2568
2569 it->push(&_annotations);
2570 it->push((Klass**)&_array_klasses);
2571 if (!is_rewritten()) {
2572 it->push(&_constants, MetaspaceClosure::_writable);
2573 } else {
2574 it->push(&_constants);
2575 }
2576 it->push(&_inner_classes);
2577 #if INCLUDE_JVMTI
2578 it->push(&_previous_versions);
2579 #endif
2580 #if INCLUDE_CDS
2581 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2582 // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2583 // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2584 // The length check on the _methods is necessary because classes which don't have any
2585 // methods share the Universe::_the_empty_method_array which is in the RO region.
2586 if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2587 // To handle jsr bytecode, new Method* maybe stored into _methods
2588 it->push(&_methods, MetaspaceClosure::_writable);
2589 } else {
2590 #endif
2591 it->push(&_methods);
2592 #if INCLUDE_CDS
2593 }
2594 #endif
2595 it->push(&_default_methods);
2596 it->push(&_local_interfaces);
2597 it->push(&_transitive_interfaces);
2598 it->push(&_method_ordering);
2599 if (!is_rewritten()) {
2600 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2601 } else {
2602 it->push(&_default_vtable_indices);
2603 }
2604
2605 it->push(&_fieldinfo_stream);
2606 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2607 it->push(&_fields_status, MetaspaceClosure::_writable);
2608
2609 if (itable_length() > 0) {
2610 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2611 int method_table_offset_in_words = ioe->offset()/wordSize;
2612 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2613
2614 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2615 / itableOffsetEntry::size();
2616
2617 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2618 if (ioe->interface_klass() != nullptr) {
2619 it->push(ioe->interface_klass_addr());
2620 itableMethodEntry* ime = ioe->first_method_entry(this);
2621 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2622 for (int index = 0; index < n; index ++) {
2623 it->push(ime[index].method_addr());
2624 }
2625 }
2626 }
2627 }
2628
2629 it->push(&_nest_host);
2630 it->push(&_nest_members);
2631 it->push(&_permitted_subclasses);
2632 it->push(&_record_components);
2633 }
2634
2635 #if INCLUDE_CDS
2636 void InstanceKlass::remove_unshareable_info() {
2637
2638 if (is_linked()) {
2639 assert(can_be_verified_at_dumptime(), "must be");
2640 // Remember this so we can avoid walking the hierarchy at runtime.
2641 set_verified_at_dump_time();
2642 }
2643
2644 Klass::remove_unshareable_info();
2645
2646 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2647 // Classes are attempted to link during dumping and may fail,
2648 // but these classes are still in the dictionary and class list in CLD.
2649 // If the class has failed verification, there is nothing else to remove.
2650 return;
2651 }
2652
2653 // Reset to the 'allocated' state to prevent any premature accessing to
2654 // a shared class at runtime while the class is still being loaded and
2655 // restored. A class' init_state is set to 'loaded' at runtime when it's
2656 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2657 _init_state = allocated;
2658
2659 { // Otherwise this needs to take out the Compile_lock.
2660 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2661 init_implementor();
2662 }
2663
2664 // Call remove_unshareable_info() on other objects that belong to this class, except
2665 // for constants()->remove_unshareable_info(), which is called in a separate pass in
2666 // ArchiveBuilder::make_klasses_shareable(),
2667
2668 for (int i = 0; i < methods()->length(); i++) {
2669 Method* m = methods()->at(i);
2670 m->remove_unshareable_info();
2671 }
2672
2673 // do array classes also.
2674 if (array_klasses() != nullptr) {
2675 array_klasses()->remove_unshareable_info();
2676 }
2677
2678 // These are not allocated from metaspace. They are safe to set to null.
2679 _source_debug_extension = nullptr;
2680 _dep_context = nullptr;
2681 _osr_nmethods_head = nullptr;
2682 #if INCLUDE_JVMTI
2683 _breakpoints = nullptr;
2684 _previous_versions = nullptr;
2685 _cached_class_file = nullptr;
2686 _jvmti_cached_class_field_map = nullptr;
2687 #endif
2688
2689 _init_thread = nullptr;
2690 _methods_jmethod_ids = nullptr;
2691 _jni_ids = nullptr;
2692 _oop_map_cache = nullptr;
2693 if (CDSConfig::is_dumping_method_handles() && HeapShared::is_lambda_proxy_klass(this)) {
2694 // keep _nest_host
2695 } else {
2696 // clear _nest_host to ensure re-load at runtime
2697 _nest_host = nullptr;
2698 }
2699 init_shared_package_entry();
2700 _dep_context_last_cleaned = 0;
2701 DEBUG_ONLY(_shared_class_load_count = 0);
2702
2703 remove_unshareable_flags();
2704 }
2705
2706 void InstanceKlass::remove_unshareable_flags() {
2707 // clear all the flags/stats that shouldn't be in the archived version
2708 assert(!is_scratch_class(), "must be");
2709 assert(!has_been_redefined(), "must be");
2710 #if INCLUDE_JVMTI
2711 set_is_being_redefined(false);
2712 #endif
2713 set_has_resolved_methods(false);
2714 }
2715
2716 void InstanceKlass::remove_java_mirror() {
2717 Klass::remove_java_mirror();
2718
2719 // do array classes also.
2720 if (array_klasses() != nullptr) {
2721 array_klasses()->remove_java_mirror();
2722 }
2723 }
2724
2725 void InstanceKlass::init_shared_package_entry() {
2726 assert(CDSConfig::is_dumping_archive(), "must be");
2727 #if !INCLUDE_CDS_JAVA_HEAP
2728 _package_entry = nullptr;
2729 #else
2730 if (CDSConfig::is_dumping_full_module_graph()) {
2731 if (is_shared_unregistered_class()) {
2732 _package_entry = nullptr;
2733 } else {
2734 _package_entry = PackageEntry::get_archived_entry(_package_entry);
2735 }
2736 } else if (CDSConfig::is_dumping_dynamic_archive() &&
2737 CDSConfig::is_using_full_module_graph() &&
2738 MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
2739 // _package_entry is an archived package in the base archive. Leave it as is.
2740 } else {
2741 _package_entry = nullptr;
2742 }
2743 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2744 #endif
2745 }
2746
2747 void InstanceKlass::compute_has_loops_flag_for_methods() {
2748 Array<Method*>* methods = this->methods();
2749 for (int index = 0; index < methods->length(); ++index) {
2750 Method* m = methods->at(index);
2751 if (!m->is_overpass()) { // work around JDK-8305771
2752 m->compute_has_loops_flag();
2753 }
2754 }
2755 }
2756
2757 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2758 PackageEntry* pkg_entry, TRAPS) {
2759 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2760 // before the InstanceKlass is added to the SystemDictionary. Make
2761 // sure the current state is <loaded.
2762 assert(!is_loaded(), "invalid init state");
2763 assert(!shared_loading_failed(), "Must not try to load failed class again");
2764 set_package(loader_data, pkg_entry, CHECK);
2765 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2766
2767 Array<Method*>* methods = this->methods();
2768 int num_methods = methods->length();
2769 for (int index = 0; index < num_methods; ++index) {
2770 methods->at(index)->restore_unshareable_info(CHECK);
2771 }
2772 #if INCLUDE_JVMTI
2773 if (JvmtiExport::has_redefined_a_class()) {
2774 // Reinitialize vtable because RedefineClasses may have changed some
2775 // entries in this vtable for super classes so the CDS vtable might
2776 // point to old or obsolete entries. RedefineClasses doesn't fix up
2777 // vtables in the shared system dictionary, only the main one.
2778 // It also redefines the itable too so fix that too.
2779 // First fix any default methods that point to a super class that may
2780 // have been redefined.
2781 bool trace_name_printed = false;
2782 adjust_default_methods(&trace_name_printed);
2783 if (verified_at_dump_time()) {
2784 // Initialize vtable and itable for classes which can be verified at dump time.
2785 // Unlinked classes such as old classes with major version < 50 cannot be verified
2786 // at dump time.
2787 vtable().initialize_vtable();
2788 itable().initialize_itable();
2789 }
2790 }
2791 #endif // INCLUDE_JVMTI
2792
2793 // restore constant pool resolved references
2794 constants()->restore_unshareable_info(CHECK);
2795
2796 if (array_klasses() != nullptr) {
2797 // To get a consistent list of classes we need MultiArray_lock to ensure
2798 // array classes aren't observed while they are being restored.
2799 RecursiveLocker rl(MultiArray_lock, THREAD);
2800 assert(this == array_klasses()->bottom_klass(), "sanity");
2801 // Array classes have null protection domain.
2802 // --> see ArrayKlass::complete_create_array_klass()
2803 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2804 }
2805
2806 // Initialize @ValueBased class annotation if not already set in the archived klass.
2807 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
2808 set_is_value_based();
2809 }
2810 }
2811
2812 // Check if a class or any of its supertypes has a version older than 50.
2813 // CDS will not perform verification of old classes during dump time because
2814 // without changing the old verifier, the verification constraint cannot be
2815 // retrieved during dump time.
2816 // Verification of archived old classes will be performed during run time.
2817 bool InstanceKlass::can_be_verified_at_dumptime() const {
2818 if (MetaspaceShared::is_in_shared_metaspace(this)) {
2819 // This is a class that was dumped into the base archive, so we know
2820 // it was verified at dump time.
2821 return true;
2822 }
2823 if (major_version() < 50 /*JAVA_6_VERSION*/) {
2824 return false;
2825 }
2826 if (java_super() != nullptr && !java_super()->can_be_verified_at_dumptime()) {
2827 return false;
2828 }
2829 Array<InstanceKlass*>* interfaces = local_interfaces();
2830 int len = interfaces->length();
2831 for (int i = 0; i < len; i++) {
2832 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2833 return false;
2834 }
2835 }
2836 return true;
2837 }
2838
2839 int InstanceKlass::shared_class_loader_type() const {
2840 if (is_shared_boot_class()) {
2841 return ClassLoader::BOOT_LOADER;
2842 } else if (is_shared_platform_class()) {
2843 return ClassLoader::PLATFORM_LOADER;
2844 } else if (is_shared_app_class()) {
2845 return ClassLoader::APP_LOADER;
2846 } else {
2847 return ClassLoader::OTHER;
2848 }
2849 }
2850 #endif // INCLUDE_CDS
2851
2852 #if INCLUDE_JVMTI
2853 static void clear_all_breakpoints(Method* m) {
2854 m->clear_all_breakpoints();
2855 }
2856 #endif
2857
2858 void InstanceKlass::unload_class(InstanceKlass* ik) {
2859
2860 if (ik->is_scratch_class()) {
2861 assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
2862 return;
2863 }
2864 assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
2865
2866 // Release dependencies.
2867 ik->dependencies().remove_all_dependents();
2868
2869 // notify the debugger
2870 if (JvmtiExport::should_post_class_unload()) {
2871 JvmtiExport::post_class_unload(ik);
2872 }
2873
2874 // notify ClassLoadingService of class unload
2875 ClassLoadingService::notify_class_unloaded(ik);
2876
2877 SystemDictionaryShared::handle_class_unloading(ik);
2878
2879 if (log_is_enabled(Info, class, unload)) {
2880 ResourceMark rm;
2881 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2882 }
2883
2884 Events::log_class_unloading(Thread::current(), ik);
2885
2886 #if INCLUDE_JFR
2887 assert(ik != nullptr, "invariant");
2888 EventClassUnload event;
2889 event.set_unloadedClass(ik);
2890 event.set_definingClassLoader(ik->class_loader_data());
2891 event.commit();
2892 #endif
2893 }
2894
2895 static void method_release_C_heap_structures(Method* m) {
2896 m->release_C_heap_structures();
2897 }
2898
2899 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2900 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2901 // Clean up C heap
2902 Klass::release_C_heap_structures();
2903
2904 // Deallocate and call destructors for MDO mutexes
2905 if (release_sub_metadata) {
2906 methods_do(method_release_C_heap_structures);
2907 }
2908
2909 // Deallocate oop map cache
2910 if (_oop_map_cache != nullptr) {
2911 delete _oop_map_cache;
2912 _oop_map_cache = nullptr;
2913 }
2914
2915 // Deallocate JNI identifiers for jfieldIDs
2916 JNIid::deallocate(jni_ids());
2917 set_jni_ids(nullptr);
2918
2919 jmethodID* jmeths = methods_jmethod_ids_acquire();
2920 if (jmeths != nullptr) {
2921 release_set_methods_jmethod_ids(nullptr);
2922 FreeHeap(jmeths);
2923 }
2924
2925 assert(_dep_context == nullptr,
2926 "dependencies should already be cleaned");
2927
2928 #if INCLUDE_JVMTI
2929 // Deallocate breakpoint records
2930 if (breakpoints() != nullptr) {
2931 methods_do(clear_all_breakpoints);
2932 assert(breakpoints() == nullptr, "should have cleared breakpoints");
2933 }
2934
2935 // deallocate the cached class file
2936 if (_cached_class_file != nullptr) {
2937 os::free(_cached_class_file);
2938 _cached_class_file = nullptr;
2939 }
2940 #endif
2941
2942 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2943
2944 if (release_sub_metadata) {
2945 constants()->release_C_heap_structures();
2946 }
2947 }
2948
2949 // The constant pool is on stack if any of the methods are executing or
2950 // referenced by handles.
2951 bool InstanceKlass::on_stack() const {
2952 return _constants->on_stack();
2953 }
2954
2955 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
2956 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
2957 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
2958
2959 // minor and major version numbers of class file
2960 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
2961 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
2962 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
2963 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
2964
2965 InstanceKlass* InstanceKlass::get_klass_version(int version) {
2966 for (InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
2967 if (ik->constants()->version() == version) {
2968 return ik;
2969 }
2970 }
2971 return nullptr;
2972 }
2973
2974 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2975 if (array == nullptr) {
2976 _source_debug_extension = nullptr;
2977 } else {
2978 // Adding one to the attribute length in order to store a null terminator
2979 // character could cause an overflow because the attribute length is
2980 // already coded with an u4 in the classfile, but in practice, it's
2981 // unlikely to happen.
2982 assert((length+1) > length, "Overflow checking");
2983 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2984 for (int i = 0; i < length; i++) {
2985 sde[i] = array[i];
2986 }
2987 sde[length] = '\0';
2988 _source_debug_extension = sde;
2989 }
2990 }
2991
2992 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
2993 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
2994 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
2995
2996 const char* InstanceKlass::signature_name() const {
2997
2998 // Get the internal name as a c string
2999 const char* src = (const char*) (name()->as_C_string());
3000 const int src_length = (int)strlen(src);
3001
3002 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3003
3004 // Add L as type indicator
3005 int dest_index = 0;
3006 dest[dest_index++] = JVM_SIGNATURE_CLASS;
3007
3008 // Add the actual class name
3009 for (int src_index = 0; src_index < src_length; ) {
3010 dest[dest_index++] = src[src_index++];
3011 }
3012
3013 if (is_hidden()) { // Replace the last '+' with a '.'.
3014 for (int index = (int)src_length; index > 0; index--) {
3015 if (dest[index] == '+') {
3016 dest[index] = JVM_SIGNATURE_DOT;
3017 break;
3018 }
3019 }
3020 }
3021
3022 // Add the semicolon and the null
3023 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3024 dest[dest_index] = '\0';
3025 return dest;
3026 }
3027
3028 ModuleEntry* InstanceKlass::module() const {
3029 if (is_hidden() &&
3030 in_unnamed_package() &&
3031 class_loader_data()->has_class_mirror_holder()) {
3032 // For a non-strong hidden class defined to an unnamed package,
3033 // its (class held) CLD will not have an unnamed module created for it.
3034 // Two choices to find the correct ModuleEntry:
3035 // 1. If hidden class is within a nest, use nest host's module
3036 // 2. Find the unnamed module off from the class loader
3037 // For now option #2 is used since a nest host is not set until
3038 // after the instance class is created in jvm_lookup_define_class().
3039 if (class_loader_data()->is_boot_class_loader_data()) {
3040 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3041 } else {
3042 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3043 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3044 return java_lang_Module::module_entry(module);
3045 }
3046 }
3047
3048 // Class is in a named package
3049 if (!in_unnamed_package()) {
3050 return _package_entry->module();
3051 }
3052
3053 // Class is in an unnamed package, return its loader's unnamed module
3054 return class_loader_data()->unnamed_module();
3055 }
3056
3057 bool InstanceKlass::in_javabase_module() const {
3058 return module()->name() == vmSymbols::java_base();
3059 }
3060
3061 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3062
3063 // ensure java/ packages only loaded by boot or platform builtin loaders
3064 // not needed for shared class since CDS does not archive prohibited classes.
3065 if (!is_shared()) {
3066 check_prohibited_package(name(), loader_data, CHECK);
3067 }
3068
3069 if (is_shared() && _package_entry != nullptr) {
3070 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3071 // we can use the saved package
3072 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
3073 return;
3074 } else {
3075 _package_entry = nullptr;
3076 }
3077 }
3078
3079 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3080 // it returns, so we need to decrement it when the current function exits.
3081 TempNewSymbol from_class_name =
3082 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3083
3084 Symbol* pkg_name;
3085 if (pkg_entry != nullptr) {
3086 pkg_name = pkg_entry->name();
3087 } else {
3088 pkg_name = from_class_name;
3089 }
3090
3091 if (pkg_name != nullptr && loader_data != nullptr) {
3092
3093 // Find in class loader's package entry table.
3094 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3095
3096 // If the package name is not found in the loader's package
3097 // entry table, it is an indication that the package has not
3098 // been defined. Consider it defined within the unnamed module.
3099 if (_package_entry == nullptr) {
3100
3101 if (!ModuleEntryTable::javabase_defined()) {
3102 // Before java.base is defined during bootstrapping, define all packages in
3103 // the java.base module. If a non-java.base package is erroneously placed
3104 // in the java.base module it will be caught later when java.base
3105 // is defined by ModuleEntryTable::verify_javabase_packages check.
3106 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3107 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3108 } else {
3109 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3110 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3111 }
3112
3113 // A package should have been successfully created
3114 DEBUG_ONLY(ResourceMark rm(THREAD));
3115 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3116 name()->as_C_string(), loader_data->loader_name_and_id());
3117 }
3118
3119 if (log_is_enabled(Debug, module)) {
3120 ResourceMark rm(THREAD);
3121 ModuleEntry* m = _package_entry->module();
3122 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3123 external_name(),
3124 pkg_name->as_C_string(),
3125 loader_data->loader_name_and_id(),
3126 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3127 }
3128 } else {
3129 ResourceMark rm(THREAD);
3130 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3131 external_name(),
3132 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3133 UNNAMED_MODULE);
3134 }
3135 }
3136
3137 // Function set_classpath_index ensures that for a non-null _package_entry
3138 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3139 // It then sets the classpath_index in the package entry record.
3140 //
3141 // The classpath_index field is used to find the entry on the boot loader class
3142 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3143 // in an unnamed module. It is also used to indicate (for all packages whose
3144 // classes are loaded by the boot loader) that at least one of the package's
3145 // classes has been loaded.
3146 void InstanceKlass::set_classpath_index(s2 path_index) {
3147 if (_package_entry != nullptr) {
3148 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3149 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3150 assert(path_index != -1, "Unexpected classpath_index");
3151 _package_entry->set_classpath_index(path_index);
3152 }
3153 }
3154
3155 // different versions of is_same_class_package
3156
3157 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3158 oop classloader1 = this->class_loader();
3159 PackageEntry* classpkg1 = this->package();
3160 if (class2->is_objArray_klass()) {
3161 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3162 }
3163
3164 oop classloader2;
3165 PackageEntry* classpkg2;
3166 if (class2->is_instance_klass()) {
3167 classloader2 = class2->class_loader();
3168 classpkg2 = class2->package();
3169 } else {
3170 assert(class2->is_typeArray_klass(), "should be type array");
3171 classloader2 = nullptr;
3172 classpkg2 = nullptr;
3173 }
3174
3175 // Same package is determined by comparing class loader
3176 // and package entries. Both must be the same. This rule
3177 // applies even to classes that are defined in the unnamed
3178 // package, they still must have the same class loader.
3179 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3180 return true;
3181 }
3182
3183 return false;
3184 }
3185
3186 // return true if this class and other_class are in the same package. Classloader
3187 // and classname information is enough to determine a class's package
3188 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3189 const Symbol* other_class_name) const {
3190 if (class_loader() != other_class_loader) {
3191 return false;
3192 }
3193 if (name()->fast_compare(other_class_name) == 0) {
3194 return true;
3195 }
3196
3197 {
3198 ResourceMark rm;
3199
3200 bool bad_class_name = false;
3201 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3202 if (bad_class_name) {
3203 return false;
3204 }
3205 // Check that package_from_class_name() returns null, not "", if there is no package.
3206 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3207
3208 const Symbol* const this_package_name =
3209 this->package() != nullptr ? this->package()->name() : nullptr;
3210
3211 if (this_package_name == nullptr || other_pkg == nullptr) {
3212 // One of the two doesn't have a package. Only return true if the other
3213 // one also doesn't have a package.
3214 return this_package_name == other_pkg;
3215 }
3216
3217 // Check if package is identical
3218 return this_package_name->fast_compare(other_pkg) == 0;
3219 }
3220 }
3221
3222 static bool is_prohibited_package_slow(Symbol* class_name) {
3223 // Caller has ResourceMark
3224 int length;
3225 jchar* unicode = class_name->as_unicode(length);
3226 return (length >= 5 &&
3227 unicode[0] == 'j' &&
3228 unicode[1] == 'a' &&
3229 unicode[2] == 'v' &&
3230 unicode[3] == 'a' &&
3231 unicode[4] == '/');
3232 }
3233
3234 // Only boot and platform class loaders can define classes in "java/" packages.
3235 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3236 ClassLoaderData* loader_data,
3237 TRAPS) {
3238 if (!loader_data->is_boot_class_loader_data() &&
3239 !loader_data->is_platform_class_loader_data() &&
3240 class_name != nullptr && class_name->utf8_length() >= 5) {
3241 ResourceMark rm(THREAD);
3242 bool prohibited;
3243 const u1* base = class_name->base();
3244 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3245 prohibited = is_prohibited_package_slow(class_name);
3246 } else {
3247 char* name = class_name->as_C_string();
3248 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3249 }
3250 if (prohibited) {
3251 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3252 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3253 char* name = pkg_name->as_C_string();
3254 const char* class_loader_name = loader_data->loader_name_and_id();
3255 StringUtils::replace_no_expand(name, "/", ".");
3256 const char* msg_text1 = "Class loader (instance of): ";
3257 const char* msg_text2 = " tried to load prohibited package name: ";
3258 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3259 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3260 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3261 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3262 }
3263 }
3264 return;
3265 }
3266
3267 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3268 constantPoolHandle i_cp(THREAD, constants());
3269 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3270 int ioff = iter.inner_class_info_index();
3271 if (ioff != 0) {
3272 // Check to see if the name matches the class we're looking for
3273 // before attempting to find the class.
3274 if (i_cp->klass_name_at_matches(this, ioff)) {
3275 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3276 if (this == inner_klass) {
3277 *ooff = iter.outer_class_info_index();
3278 *noff = iter.inner_name_index();
3279 return true;
3280 }
3281 }
3282 }
3283 }
3284 return false;
3285 }
3286
3287 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3288 InstanceKlass* outer_klass = nullptr;
3289 *inner_is_member = false;
3290 int ooff = 0, noff = 0;
3291 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3292 if (has_inner_classes_attr) {
3293 constantPoolHandle i_cp(THREAD, constants());
3294 if (ooff != 0) {
3295 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3296 if (!ok->is_instance_klass()) {
3297 // If the outer class is not an instance klass then it cannot have
3298 // declared any inner classes.
3299 ResourceMark rm(THREAD);
3300 // Names are all known to be < 64k so we know this formatted message is not excessively large.
3301 Exceptions::fthrow(
3302 THREAD_AND_LOCATION,
3303 vmSymbols::java_lang_IncompatibleClassChangeError(),
3304 "%s and %s disagree on InnerClasses attribute",
3305 ok->external_name(),
3306 external_name());
3307 return nullptr;
3308 }
3309 outer_klass = InstanceKlass::cast(ok);
3310 *inner_is_member = true;
3311 }
3312 if (nullptr == outer_klass) {
3313 // It may be a local class; try for that.
3314 int encl_method_class_idx = enclosing_method_class_index();
3315 if (encl_method_class_idx != 0) {
3316 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3317 outer_klass = InstanceKlass::cast(ok);
3318 *inner_is_member = false;
3319 }
3320 }
3321 }
3322
3323 // If no inner class attribute found for this class.
3324 if (nullptr == outer_klass) return nullptr;
3325
3326 // Throws an exception if outer klass has not declared k as an inner klass
3327 // We need evidence that each klass knows about the other, or else
3328 // the system could allow a spoof of an inner class to gain access rights.
3329 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3330 return outer_klass;
3331 }
3332
3333 u2 InstanceKlass::compute_modifier_flags() const {
3334 u2 access = access_flags().as_unsigned_short();
3335
3336 // But check if it happens to be member class.
3337 InnerClassesIterator iter(this);
3338 for (; !iter.done(); iter.next()) {
3339 int ioff = iter.inner_class_info_index();
3340 // Inner class attribute can be zero, skip it.
3341 // Strange but true: JVM spec. allows null inner class refs.
3342 if (ioff == 0) continue;
3343
3344 // only look at classes that are already loaded
3345 // since we are looking for the flags for our self.
3346 Symbol* inner_name = constants()->klass_name_at(ioff);
3347 if (name() == inner_name) {
3348 // This is really a member class.
3349 access = iter.inner_access_flags();
3350 break;
3351 }
3352 }
3353 // Remember to strip ACC_SUPER bit
3354 return (access & (~JVM_ACC_SUPER));
3355 }
3356
3357 jint InstanceKlass::jvmti_class_status() const {
3358 jint result = 0;
3359
3360 if (is_linked()) {
3361 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3362 }
3363
3364 if (is_initialized()) {
3365 assert(is_linked(), "Class status is not consistent");
3366 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3367 }
3368 if (is_in_error_state()) {
3369 result |= JVMTI_CLASS_STATUS_ERROR;
3370 }
3371 return result;
3372 }
3373
3374 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3375 bool implements_interface; // initialized by method_at_itable_or_null
3376 Method* m = method_at_itable_or_null(holder, index,
3377 implements_interface); // out parameter
3378 if (m != nullptr) {
3379 assert(implements_interface, "sanity");
3380 return m;
3381 } else if (implements_interface) {
3382 // Throw AbstractMethodError since corresponding itable slot is empty.
3383 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3384 } else {
3385 // If the interface isn't implemented by the receiver class,
3386 // the VM should throw IncompatibleClassChangeError.
3387 ResourceMark rm(THREAD);
3388 stringStream ss;
3389 bool same_module = (module() == holder->module());
3390 ss.print("Receiver class %s does not implement "
3391 "the interface %s defining the method to be called "
3392 "(%s%s%s)",
3393 external_name(), holder->external_name(),
3394 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3395 (same_module) ? "" : "; ",
3396 (same_module) ? "" : holder->class_in_module_of_loader());
3397 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3398 }
3399 }
3400
3401 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3402 klassItable itable(this);
3403 for (int i = 0; i < itable.size_offset_table(); i++) {
3404 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3405 if (offset_entry->interface_klass() == holder) {
3406 implements_interface = true;
3407 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3408 Method* m = ime[index].method();
3409 return m;
3410 }
3411 }
3412 implements_interface = false;
3413 return nullptr; // offset entry not found
3414 }
3415
3416 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3417 assert(is_linked(), "required");
3418 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3419 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3420
3421 int vtable_index = Method::invalid_vtable_index;
3422 Symbol* name = intf_method->name();
3423 Symbol* signature = intf_method->signature();
3424
3425 // First check in default method array
3426 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3427 int index = find_method_index(default_methods(),
3428 name, signature,
3429 Klass::OverpassLookupMode::find,
3430 Klass::StaticLookupMode::find,
3431 Klass::PrivateLookupMode::find);
3432 if (index >= 0) {
3433 vtable_index = default_vtable_indices()->at(index);
3434 }
3435 }
3436 if (vtable_index == Method::invalid_vtable_index) {
3437 // get vtable_index for miranda methods
3438 klassVtable vt = vtable();
3439 vtable_index = vt.index_of_miranda(name, signature);
3440 }
3441 return vtable_index;
3442 }
3443
3444 #if INCLUDE_JVMTI
3445 // update default_methods for redefineclasses for methods that are
3446 // not yet in the vtable due to concurrent subclass define and superinterface
3447 // redefinition
3448 // Note: those in the vtable, should have been updated via adjust_method_entries
3449 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3450 // search the default_methods for uses of either obsolete or EMCP methods
3451 if (default_methods() != nullptr) {
3452 for (int index = 0; index < default_methods()->length(); index ++) {
3453 Method* old_method = default_methods()->at(index);
3454 if (old_method == nullptr || !old_method->is_old()) {
3455 continue; // skip uninteresting entries
3456 }
3457 assert(!old_method->is_deleted(), "default methods may not be deleted");
3458 Method* new_method = old_method->get_new_method();
3459 default_methods()->at_put(index, new_method);
3460
3461 if (log_is_enabled(Info, redefine, class, update)) {
3462 ResourceMark rm;
3463 if (!(*trace_name_printed)) {
3464 log_info(redefine, class, update)
3465 ("adjust: klassname=%s default methods from name=%s",
3466 external_name(), old_method->method_holder()->external_name());
3467 *trace_name_printed = true;
3468 }
3469 log_debug(redefine, class, update, vtables)
3470 ("default method update: %s(%s) ",
3471 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3472 }
3473 }
3474 }
3475 }
3476 #endif // INCLUDE_JVMTI
3477
3478 // On-stack replacement stuff
3479 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3480 assert_lock_strong(NMethodState_lock);
3481 #ifndef PRODUCT
3482 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3483 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3484 "redundant OSR recompilation detected. memory leak in CodeCache!");
3485 #endif
3486 // only one compilation can be active
3487 assert(n->is_osr_method(), "wrong kind of nmethod");
3488 n->set_osr_link(osr_nmethods_head());
3489 set_osr_nmethods_head(n);
3490 // Raise the highest osr level if necessary
3491 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3492
3493 // Get rid of the osr methods for the same bci that have lower levels.
3494 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3495 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3496 if (inv != nullptr && inv->is_in_use()) {
3497 inv->make_not_entrant("OSR invalidation of lower levels");
3498 }
3499 }
3500 }
3501
3502 // Remove osr nmethod from the list. Return true if found and removed.
3503 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3504 // This is a short non-blocking critical region, so the no safepoint check is ok.
3505 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3506 assert(n->is_osr_method(), "wrong kind of nmethod");
3507 nmethod* last = nullptr;
3508 nmethod* cur = osr_nmethods_head();
3509 int max_level = CompLevel_none; // Find the max comp level excluding n
3510 Method* m = n->method();
3511 // Search for match
3512 bool found = false;
3513 while(cur != nullptr && cur != n) {
3514 if (m == cur->method()) {
3515 // Find max level before n
3516 max_level = MAX2(max_level, cur->comp_level());
3517 }
3518 last = cur;
3519 cur = cur->osr_link();
3520 }
3521 nmethod* next = nullptr;
3522 if (cur == n) {
3523 found = true;
3524 next = cur->osr_link();
3525 if (last == nullptr) {
3526 // Remove first element
3527 set_osr_nmethods_head(next);
3528 } else {
3529 last->set_osr_link(next);
3530 }
3531 }
3532 n->set_osr_link(nullptr);
3533 cur = next;
3534 while (cur != nullptr) {
3535 // Find max level after n
3536 if (m == cur->method()) {
3537 max_level = MAX2(max_level, cur->comp_level());
3538 }
3539 cur = cur->osr_link();
3540 }
3541 m->set_highest_osr_comp_level(max_level);
3542 return found;
3543 }
3544
3545 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3546 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3547 nmethod* osr = osr_nmethods_head();
3548 int found = 0;
3549 while (osr != nullptr) {
3550 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3551 if (osr->method() == m) {
3552 deopt_scope->mark(osr);
3553 found++;
3554 }
3555 osr = osr->osr_link();
3556 }
3557 return found;
3558 }
3559
3560 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3561 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3562 nmethod* osr = osr_nmethods_head();
3563 nmethod* best = nullptr;
3564 while (osr != nullptr) {
3565 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3566 // There can be a time when a c1 osr method exists but we are waiting
3567 // for a c2 version. When c2 completes its osr nmethod we will trash
3568 // the c1 version and only be able to find the c2 version. However
3569 // while we overflow in the c1 code at back branches we don't want to
3570 // try and switch to the same code as we are already running
3571
3572 if (osr->method() == m &&
3573 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3574 if (match_level) {
3575 if (osr->comp_level() == comp_level) {
3576 // Found a match - return it.
3577 return osr;
3578 }
3579 } else {
3580 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3581 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3582 // Found the best possible - return it.
3583 return osr;
3584 }
3585 best = osr;
3586 }
3587 }
3588 }
3589 osr = osr->osr_link();
3590 }
3591
3592 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3593 if (best != nullptr && best->comp_level() >= comp_level) {
3594 return best;
3595 }
3596 return nullptr;
3597 }
3598
3599 // -----------------------------------------------------------------------------------------------------
3600 // Printing
3601
3602 #define BULLET " - "
3603
3604 static const char* state_names[] = {
3605 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3606 };
3607
3608 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3609 for (int i = 0; i < len; i++) {
3610 intptr_t e = start[i];
3611 st->print("%d : " INTPTR_FORMAT, i, e);
3612 if (MetaspaceObj::is_valid((Metadata*)e)) {
3613 st->print(" ");
3614 ((Metadata*)e)->print_value_on(st);
3615 }
3616 st->cr();
3617 }
3618 }
3619
3620 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3621 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3622 }
3623
3624 const char* InstanceKlass::init_state_name() const {
3625 return state_names[init_state()];
3626 }
3627
3628 void InstanceKlass::print_on(outputStream* st) const {
3629 assert(is_klass(), "must be klass");
3630 Klass::print_on(st);
3631
3632 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3633 st->print(BULLET"klass size: %d", size()); st->cr();
3634 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3635 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
3636 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
3637 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3638 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3639 st->print(BULLET"sub: ");
3640 Klass* sub = subklass();
3641 int n;
3642 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3643 if (n < MaxSubklassPrintSize) {
3644 sub->print_value_on(st);
3645 st->print(" ");
3646 }
3647 }
3648 if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
3649 st->cr();
3650
3651 if (is_interface()) {
3652 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3653 if (nof_implementors() == 1) {
3654 st->print_cr(BULLET"implementor: ");
3655 st->print(" ");
3656 implementor()->print_value_on(st);
3657 st->cr();
3658 }
3659 }
3660
3661 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3662 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3663 if (Verbose || WizardMode) {
3664 Array<Method*>* method_array = methods();
3665 for (int i = 0; i < method_array->length(); i++) {
3666 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3667 }
3668 }
3669 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3670 if (default_methods() != nullptr) {
3671 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3672 if (Verbose) {
3673 Array<Method*>* method_array = default_methods();
3674 for (int i = 0; i < method_array->length(); i++) {
3675 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3676 }
3677 }
3678 }
3679 print_on_maybe_null(st, BULLET"default vtable indices: ", default_vtable_indices());
3680 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3681 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3682
3683 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
3684
3685 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
3686 st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
3687
3688 if (secondary_supers() != nullptr) {
3689 if (Verbose) {
3690 bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
3691 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
3692 for (int i = 0; i < _secondary_supers->length(); i++) {
3693 ResourceMark rm; // for external_name()
3694 Klass* secondary_super = _secondary_supers->at(i);
3695 st->print(BULLET"%2d:", i);
3696 if (is_hashed) {
3697 int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
3698 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
3699 st->print(" dist:%02d:", distance);
3700 }
3701 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
3702 }
3703 }
3704 }
3705 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3706
3707 print_on_maybe_null(st, BULLET"class loader data: ", class_loader_data());
3708 print_on_maybe_null(st, BULLET"source file: ", source_file_name());
3709 if (source_debug_extension() != nullptr) {
3710 st->print(BULLET"source debug extension: ");
3711 st->print("%s", source_debug_extension());
3712 st->cr();
3713 }
3714 print_on_maybe_null(st, BULLET"class annotations: ", class_annotations());
3715 print_on_maybe_null(st, BULLET"class type annotations: ", class_type_annotations());
3716 print_on_maybe_null(st, BULLET"field annotations: ", fields_annotations());
3717 print_on_maybe_null(st, BULLET"field type annotations: ", fields_type_annotations());
3718 {
3719 bool have_pv = false;
3720 // previous versions are linked together through the InstanceKlass
3721 for (InstanceKlass* pv_node = previous_versions();
3722 pv_node != nullptr;
3723 pv_node = pv_node->previous_versions()) {
3724 if (!have_pv)
3725 st->print(BULLET"previous version: ");
3726 have_pv = true;
3727 pv_node->constants()->print_value_on(st);
3728 }
3729 if (have_pv) st->cr();
3730 }
3731
3732 print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
3733 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3734 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3735 print_on_maybe_null(st, BULLET"record components: ", record_components());
3736 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
3737 if (java_mirror() != nullptr) {
3738 st->print(BULLET"java mirror: ");
3739 java_mirror()->print_value_on(st);
3740 st->cr();
3741 } else {
3742 st->print_cr(BULLET"java mirror: null");
3743 }
3744 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3745 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3746 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3747 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3748 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3749
3750 FieldPrinter print_static_field(st);
3751 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3752 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3753 FieldPrinter print_nonstatic_field(st);
3754 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3755 ik->print_nonstatic_fields(&print_nonstatic_field);
3756
3757 st->print(BULLET"non-static oop maps (%d entries): ", nonstatic_oop_map_count());
3758 OopMapBlock* map = start_of_nonstatic_oop_maps();
3759 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3760 while (map < end_map) {
3761 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3762 map++;
3763 }
3764 st->cr();
3765 }
3766
3767 void InstanceKlass::print_value_on(outputStream* st) const {
3768 assert(is_klass(), "must be klass");
3769 if (Verbose || WizardMode) access_flags().print_on(st);
3770 name()->print_value_on(st);
3771 }
3772
3773 void FieldPrinter::do_field(fieldDescriptor* fd) {
3774 _st->print(BULLET);
3775 if (_obj == nullptr) {
3776 fd->print_on(_st);
3777 _st->cr();
3778 } else {
3779 fd->print_on_for(_st, _obj);
3780 _st->cr();
3781 }
3782 }
3783
3784
3785 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3786 Klass::oop_print_on(obj, st);
3787
3788 if (this == vmClasses::String_klass()) {
3789 typeArrayOop value = java_lang_String::value(obj);
3790 juint length = java_lang_String::length(obj);
3791 if (value != nullptr &&
3792 value->is_typeArray() &&
3793 length <= (juint) value->length()) {
3794 st->print(BULLET"string: ");
3795 java_lang_String::print(obj, st);
3796 st->cr();
3797 }
3798 }
3799
3800 st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj));
3801 FieldPrinter print_field(st, obj);
3802 print_nonstatic_fields(&print_field);
3803
3804 if (this == vmClasses::Class_klass()) {
3805 st->print(BULLET"signature: ");
3806 java_lang_Class::print_signature(obj, st);
3807 st->cr();
3808 Klass* real_klass = java_lang_Class::as_Klass(obj);
3809 if (real_klass != nullptr && real_klass->is_instance_klass()) {
3810 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3811 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3812 }
3813 } else if (this == vmClasses::MethodType_klass()) {
3814 st->print(BULLET"signature: ");
3815 java_lang_invoke_MethodType::print_signature(obj, st);
3816 st->cr();
3817 }
3818 }
3819
3820 #ifndef PRODUCT
3821
3822 bool InstanceKlass::verify_itable_index(int i) {
3823 int method_count = klassItable::method_count_for_interface(this);
3824 assert(i >= 0 && i < method_count, "index out of bounds");
3825 return true;
3826 }
3827
3828 #endif //PRODUCT
3829
3830 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3831 st->print("a ");
3832 name()->print_value_on(st);
3833 obj->print_address_on(st);
3834 if (this == vmClasses::String_klass()
3835 && java_lang_String::value(obj) != nullptr) {
3836 ResourceMark rm;
3837 int len = java_lang_String::length(obj);
3838 int plen = (len < 24 ? len : 12);
3839 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3840 st->print(" = \"%s\"", str);
3841 if (len > plen)
3842 st->print("...[%d]", len);
3843 } else if (this == vmClasses::Class_klass()) {
3844 Klass* k = java_lang_Class::as_Klass(obj);
3845 st->print(" = ");
3846 if (k != nullptr) {
3847 k->print_value_on(st);
3848 } else {
3849 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3850 st->print("%s", tname ? tname : "type?");
3851 }
3852 } else if (this == vmClasses::MethodType_klass()) {
3853 st->print(" = ");
3854 java_lang_invoke_MethodType::print_signature(obj, st);
3855 } else if (java_lang_boxing_object::is_instance(obj)) {
3856 st->print(" = ");
3857 java_lang_boxing_object::print(obj, st);
3858 } else if (this == vmClasses::LambdaForm_klass()) {
3859 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3860 if (vmentry != nullptr) {
3861 st->print(" => ");
3862 vmentry->print_value_on(st);
3863 }
3864 } else if (this == vmClasses::MemberName_klass()) {
3865 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3866 if (vmtarget != nullptr) {
3867 st->print(" = ");
3868 vmtarget->print_value_on(st);
3869 } else {
3870 oop clazz = java_lang_invoke_MemberName::clazz(obj);
3871 oop name = java_lang_invoke_MemberName::name(obj);
3872 if (clazz != nullptr) {
3873 clazz->print_value_on(st);
3874 } else {
3875 st->print("null");
3876 }
3877 st->print(".");
3878 if (name != nullptr) {
3879 name->print_value_on(st);
3880 } else {
3881 st->print("null");
3882 }
3883 }
3884 }
3885 }
3886
3887 const char* InstanceKlass::internal_name() const {
3888 return external_name();
3889 }
3890
3891 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3892 const ModuleEntry* module_entry,
3893 const ClassFileStream* cfs) const {
3894
3895 if (ClassListWriter::is_enabled()) {
3896 ClassListWriter::write(this, cfs);
3897 }
3898
3899 print_class_load_helper(loader_data, module_entry, cfs);
3900 print_class_load_cause_logging();
3901 }
3902
3903 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3904 const ModuleEntry* module_entry,
3905 const ClassFileStream* cfs) const {
3906
3907 if (!log_is_enabled(Info, class, load)) {
3908 return;
3909 }
3910
3911 ResourceMark rm;
3912 LogMessage(class, load) msg;
3913 stringStream info_stream;
3914
3915 // Name and class hierarchy info
3916 info_stream.print("%s", external_name());
3917
3918 // Source
3919 if (cfs != nullptr) {
3920 if (cfs->source() != nullptr) {
3921 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3922 if (module_name != nullptr) {
3923 // When the boot loader created the stream, it didn't know the module name
3924 // yet. Let's format it now.
3925 if (cfs->from_boot_loader_modules_image()) {
3926 info_stream.print(" source: jrt:/%s", module_name);
3927 } else {
3928 info_stream.print(" source: %s", cfs->source());
3929 }
3930 } else {
3931 info_stream.print(" source: %s", cfs->source());
3932 }
3933 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3934 Thread* current = Thread::current();
3935 Klass* caller = current->is_Java_thread() ?
3936 JavaThread::cast(current)->security_get_caller_class(1):
3937 nullptr;
3938 // caller can be null, for example, during a JVMTI VM_Init hook
3939 if (caller != nullptr) {
3940 info_stream.print(" source: instance of %s", caller->external_name());
3941 } else {
3942 // source is unknown
3943 }
3944 } else {
3945 oop class_loader = loader_data->class_loader();
3946 info_stream.print(" source: %s", class_loader->klass()->external_name());
3947 }
3948 } else {
3949 assert(this->is_shared(), "must be");
3950 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3951 info_stream.print(" source: shared objects file (top)");
3952 } else {
3953 info_stream.print(" source: shared objects file");
3954 }
3955 }
3956
3957 msg.info("%s", info_stream.as_string());
3958
3959 if (log_is_enabled(Debug, class, load)) {
3960 stringStream debug_stream;
3961
3962 // Class hierarchy info
3963 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
3964 p2i(this), p2i(superklass()));
3965
3966 // Interfaces
3967 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
3968 debug_stream.print(" interfaces:");
3969 int length = local_interfaces()->length();
3970 for (int i = 0; i < length; i++) {
3971 debug_stream.print(" " PTR_FORMAT,
3972 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3973 }
3974 }
3975
3976 // Class loader
3977 debug_stream.print(" loader: [");
3978 loader_data->print_value_on(&debug_stream);
3979 debug_stream.print("]");
3980
3981 // Classfile checksum
3982 if (cfs) {
3983 debug_stream.print(" bytes: %d checksum: %08x",
3984 cfs->length(),
3985 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3986 cfs->length()));
3987 }
3988
3989 msg.debug("%s", debug_stream.as_string());
3990 }
3991 }
3992
3993 void InstanceKlass::print_class_load_cause_logging() const {
3994 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
3995 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
3996 JavaThread* current = JavaThread::current();
3997 ResourceMark rm(current);
3998 const char* name = external_name();
3999
4000 if (LogClassLoadingCauseFor == nullptr ||
4001 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4002 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4003 return;
4004 }
4005
4006 // Log Java stack first
4007 {
4008 LogMessage(class, load, cause) msg;
4009 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4010
4011 info_stream.print_cr("Java stack when loading %s:", name);
4012 current->print_stack_on(&info_stream);
4013 }
4014
4015 // Log native stack second
4016 if (log_cause_native) {
4017 // Log to string first so that lines can be indented
4018 stringStream stack_stream;
4019 char buf[O_BUFLEN];
4020 address lastpc = nullptr;
4021 NativeStackPrinter nsp(current);
4022 nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4023 true /* print_source_info */, -1 /* max stack */);
4024
4025 LogMessage(class, load, cause, native) msg;
4026 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4027 info_stream.print_cr("Native stack when loading %s:", name);
4028
4029 // Print each native stack line to the log
4030 int size = (int) stack_stream.size();
4031 char* stack = stack_stream.as_string();
4032 char* stack_end = stack + size;
4033 char* line_start = stack;
4034 for (char* p = stack; p < stack_end; p++) {
4035 if (*p == '\n') {
4036 *p = '\0';
4037 info_stream.print_cr("\t%s", line_start);
4038 line_start = p + 1;
4039 }
4040 }
4041 if (line_start < stack_end) {
4042 info_stream.print_cr("\t%s", line_start);
4043 }
4044 }
4045 }
4046 }
4047
4048 // Verification
4049
4050 class VerifyFieldClosure: public BasicOopIterateClosure {
4051 protected:
4052 template <class T> void do_oop_work(T* p) {
4053 oop obj = RawAccess<>::oop_load(p);
4054 if (!oopDesc::is_oop_or_null(obj)) {
4055 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4056 Universe::print_on(tty);
4057 guarantee(false, "boom");
4058 }
4059 }
4060 public:
4061 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
4062 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4063 };
4064
4065 void InstanceKlass::verify_on(outputStream* st) {
4066 #ifndef PRODUCT
4067 // Avoid redundant verifies, this really should be in product.
4068 if (_verify_count == Universe::verify_count()) return;
4069 _verify_count = Universe::verify_count();
4070 #endif
4071
4072 // Verify Klass
4073 Klass::verify_on(st);
4074
4075 // Verify that klass is present in ClassLoaderData
4076 guarantee(class_loader_data()->contains_klass(this),
4077 "this class isn't found in class loader data");
4078
4079 // Verify vtables
4080 if (is_linked()) {
4081 // $$$ This used to be done only for m/s collections. Doing it
4082 // always seemed a valid generalization. (DLD -- 6/00)
4083 vtable().verify(st);
4084 }
4085
4086 // Verify first subklass
4087 if (subklass() != nullptr) {
4088 guarantee(subklass()->is_klass(), "should be klass");
4089 }
4090
4091 // Verify siblings
4092 Klass* super = this->super();
4093 Klass* sib = next_sibling();
4094 if (sib != nullptr) {
4095 if (sib == this) {
4096 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4097 }
4098
4099 guarantee(sib->is_klass(), "should be klass");
4100 guarantee(sib->super() == super, "siblings should have same superklass");
4101 }
4102
4103 // Verify local interfaces
4104 if (local_interfaces()) {
4105 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4106 for (int j = 0; j < local_interfaces->length(); j++) {
4107 InstanceKlass* e = local_interfaces->at(j);
4108 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4109 }
4110 }
4111
4112 // Verify transitive interfaces
4113 if (transitive_interfaces() != nullptr) {
4114 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4115 for (int j = 0; j < transitive_interfaces->length(); j++) {
4116 InstanceKlass* e = transitive_interfaces->at(j);
4117 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4118 }
4119 }
4120
4121 // Verify methods
4122 if (methods() != nullptr) {
4123 Array<Method*>* methods = this->methods();
4124 for (int j = 0; j < methods->length(); j++) {
4125 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4126 }
4127 for (int j = 0; j < methods->length() - 1; j++) {
4128 Method* m1 = methods->at(j);
4129 Method* m2 = methods->at(j + 1);
4130 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4131 }
4132 }
4133
4134 // Verify method ordering
4135 if (method_ordering() != nullptr) {
4136 Array<int>* method_ordering = this->method_ordering();
4137 int length = method_ordering->length();
4138 if (JvmtiExport::can_maintain_original_method_order() ||
4139 ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4140 guarantee(length == methods()->length(), "invalid method ordering length");
4141 jlong sum = 0;
4142 for (int j = 0; j < length; j++) {
4143 int original_index = method_ordering->at(j);
4144 guarantee(original_index >= 0, "invalid method ordering index");
4145 guarantee(original_index < length, "invalid method ordering index");
4146 sum += original_index;
4147 }
4148 // Verify sum of indices 0,1,...,length-1
4149 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4150 } else {
4151 guarantee(length == 0, "invalid method ordering length");
4152 }
4153 }
4154
4155 // Verify default methods
4156 if (default_methods() != nullptr) {
4157 Array<Method*>* methods = this->default_methods();
4158 for (int j = 0; j < methods->length(); j++) {
4159 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4160 }
4161 for (int j = 0; j < methods->length() - 1; j++) {
4162 Method* m1 = methods->at(j);
4163 Method* m2 = methods->at(j + 1);
4164 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4165 }
4166 }
4167
4168 // Verify JNI static field identifiers
4169 if (jni_ids() != nullptr) {
4170 jni_ids()->verify(this);
4171 }
4172
4173 // Verify other fields
4174 if (constants() != nullptr) {
4175 guarantee(constants()->is_constantPool(), "should be constant pool");
4176 }
4177 }
4178
4179 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4180 Klass::oop_verify_on(obj, st);
4181 VerifyFieldClosure blk;
4182 obj->oop_iterate(&blk);
4183 }
4184
4185
4186 // JNIid class for jfieldIDs only
4187 // Note to reviewers:
4188 // These JNI functions are just moved over to column 1 and not changed
4189 // in the compressed oops workspace.
4190 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
4191 _holder = holder;
4192 _offset = offset;
4193 _next = next;
4194 debug_only(_is_static_field_id = false;)
4195 }
4196
4197
4198 JNIid* JNIid::find(int offset) {
4199 JNIid* current = this;
4200 while (current != nullptr) {
4201 if (current->offset() == offset) return current;
4202 current = current->next();
4203 }
4204 return nullptr;
4205 }
4206
4207 void JNIid::deallocate(JNIid* current) {
4208 while (current != nullptr) {
4209 JNIid* next = current->next();
4210 delete current;
4211 current = next;
4212 }
4213 }
4214
4215
4216 void JNIid::verify(Klass* holder) {
4217 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4218 int end_field_offset;
4219 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
4220
4221 JNIid* current = this;
4222 while (current != nullptr) {
4223 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4224 #ifdef ASSERT
4225 int o = current->offset();
4226 if (current->is_static_field_id()) {
4227 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4228 }
4229 #endif
4230 current = current->next();
4231 }
4232 }
4233
4234 void InstanceKlass::set_init_state(ClassState state) {
4235 #ifdef ASSERT
4236 bool good_state = is_shared() ? (_init_state <= state)
4237 : (_init_state < state);
4238 assert(good_state || state == allocated, "illegal state transition");
4239 #endif
4240 assert(_init_thread == nullptr, "should be cleared before state change");
4241 Atomic::release_store(&_init_state, state);
4242 }
4243
4244 #if INCLUDE_JVMTI
4245
4246 // RedefineClasses() support for previous versions
4247
4248 // Globally, there is at least one previous version of a class to walk
4249 // during class unloading, which is saved because old methods in the class
4250 // are still running. Otherwise the previous version list is cleaned up.
4251 bool InstanceKlass::_should_clean_previous_versions = false;
4252
4253 // Returns true if there are previous versions of a class for class
4254 // unloading only. Also resets the flag to false. purge_previous_version
4255 // will set the flag to true if there are any left, i.e., if there's any
4256 // work to do for next time. This is to avoid the expensive code cache
4257 // walk in CLDG::clean_deallocate_lists().
4258 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4259 bool ret = _should_clean_previous_versions;
4260 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4261 ret ? "true" : "false");
4262 _should_clean_previous_versions = false;
4263 return ret;
4264 }
4265
4266 // This nulls out jmethodIDs for all methods in 'klass'
4267 // It needs to be called explicitly for all previous versions of a class because these may not be cleaned up
4268 // during class unloading.
4269 // We can not use the jmethodID cache associated with klass directly because the 'previous' versions
4270 // do not have the jmethodID cache filled in. Instead, we need to lookup jmethodID for each method and this
4271 // is expensive - O(n) for one jmethodID lookup. For all contained methods it is O(n^2).
4272 // The reason for expensive jmethodID lookup for each method is that there is no direct link between method and jmethodID.
4273 void InstanceKlass::clear_jmethod_ids(InstanceKlass* klass) {
4274 Array<Method*>* method_refs = klass->methods();
4275 for (int k = 0; k < method_refs->length(); k++) {
4276 Method* method = method_refs->at(k);
4277 if (method != nullptr && method->is_obsolete()) {
4278 method->clear_jmethod_id();
4279 }
4280 }
4281 }
4282
4283 // Purge previous versions before adding new previous versions of the class and
4284 // during class unloading.
4285 void InstanceKlass::purge_previous_version_list() {
4286 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4287 assert(has_been_redefined(), "Should only be called for main class");
4288
4289 // Quick exit.
4290 if (previous_versions() == nullptr) {
4291 return;
4292 }
4293
4294 // This klass has previous versions so see what we can cleanup
4295 // while it is safe to do so.
4296
4297 int deleted_count = 0; // leave debugging breadcrumbs
4298 int live_count = 0;
4299 ClassLoaderData* loader_data = class_loader_data();
4300 assert(loader_data != nullptr, "should never be null");
4301
4302 ResourceMark rm;
4303 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4304
4305 // previous versions are linked together through the InstanceKlass
4306 InstanceKlass* pv_node = previous_versions();
4307 InstanceKlass* last = this;
4308 int version = 0;
4309
4310 // check the previous versions list
4311 for (; pv_node != nullptr; ) {
4312
4313 ConstantPool* pvcp = pv_node->constants();
4314 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4315
4316 if (!pvcp->on_stack()) {
4317 // If the constant pool isn't on stack, none of the methods
4318 // are executing. Unlink this previous_version.
4319 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4320 // so will be deallocated during the next phase of class unloading.
4321 log_trace(redefine, class, iklass, purge)
4322 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4323 // Unlink from previous version list.
4324 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4325 InstanceKlass* next = pv_node->previous_versions();
4326 clear_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4327 pv_node->link_previous_versions(nullptr); // point next to null
4328 last->link_previous_versions(next);
4329 // Delete this node directly. Nothing is referring to it and we don't
4330 // want it to increase the counter for metadata to delete in CLDG.
4331 MetadataFactory::free_metadata(loader_data, pv_node);
4332 pv_node = next;
4333 deleted_count++;
4334 version++;
4335 continue;
4336 } else {
4337 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4338 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4339 live_count++;
4340 if (pvcp->is_shared()) {
4341 // Shared previous versions can never be removed so no cleaning is needed.
4342 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4343 } else {
4344 // Previous version alive, set that clean is needed for next time.
4345 _should_clean_previous_versions = true;
4346 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4347 }
4348 }
4349
4350 // next previous version
4351 last = pv_node;
4352 pv_node = pv_node->previous_versions();
4353 version++;
4354 }
4355 log_trace(redefine, class, iklass, purge)
4356 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4357 }
4358
4359 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4360 int emcp_method_count) {
4361 int obsolete_method_count = old_methods->length() - emcp_method_count;
4362
4363 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4364 _previous_versions != nullptr) {
4365 // We have a mix of obsolete and EMCP methods so we have to
4366 // clear out any matching EMCP method entries the hard way.
4367 int local_count = 0;
4368 for (int i = 0; i < old_methods->length(); i++) {
4369 Method* old_method = old_methods->at(i);
4370 if (old_method->is_obsolete()) {
4371 // only obsolete methods are interesting
4372 Symbol* m_name = old_method->name();
4373 Symbol* m_signature = old_method->signature();
4374
4375 // previous versions are linked together through the InstanceKlass
4376 int j = 0;
4377 for (InstanceKlass* prev_version = _previous_versions;
4378 prev_version != nullptr;
4379 prev_version = prev_version->previous_versions(), j++) {
4380
4381 Array<Method*>* method_refs = prev_version->methods();
4382 for (int k = 0; k < method_refs->length(); k++) {
4383 Method* method = method_refs->at(k);
4384
4385 if (!method->is_obsolete() &&
4386 method->name() == m_name &&
4387 method->signature() == m_signature) {
4388 // The current RedefineClasses() call has made all EMCP
4389 // versions of this method obsolete so mark it as obsolete
4390 log_trace(redefine, class, iklass, add)
4391 ("%s(%s): flush obsolete method @%d in version @%d",
4392 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4393
4394 method->set_is_obsolete();
4395 break;
4396 }
4397 }
4398
4399 // The previous loop may not find a matching EMCP method, but
4400 // that doesn't mean that we can optimize and not go any
4401 // further back in the PreviousVersion generations. The EMCP
4402 // method for this generation could have already been made obsolete,
4403 // but there still may be an older EMCP method that has not
4404 // been made obsolete.
4405 }
4406
4407 if (++local_count >= obsolete_method_count) {
4408 // no more obsolete methods so bail out now
4409 break;
4410 }
4411 }
4412 }
4413 }
4414 }
4415
4416 // Save the scratch_class as the previous version if any of the methods are running.
4417 // The previous_versions are used to set breakpoints in EMCP methods and they are
4418 // also used to clean MethodData links to redefined methods that are no longer running.
4419 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4420 int emcp_method_count) {
4421 assert(Thread::current()->is_VM_thread(),
4422 "only VMThread can add previous versions");
4423
4424 ResourceMark rm;
4425 log_trace(redefine, class, iklass, add)
4426 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4427
4428 // Clean out old previous versions for this class
4429 purge_previous_version_list();
4430
4431 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4432 // a previous redefinition may be made obsolete by this redefinition.
4433 Array<Method*>* old_methods = scratch_class->methods();
4434 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4435
4436 // If the constant pool for this previous version of the class
4437 // is not marked as being on the stack, then none of the methods
4438 // in this previous version of the class are on the stack so
4439 // we don't need to add this as a previous version.
4440 ConstantPool* cp_ref = scratch_class->constants();
4441 if (!cp_ref->on_stack()) {
4442 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4443 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4444 return;
4445 }
4446
4447 // Add previous version if any methods are still running or if this is
4448 // a shared class which should never be removed.
4449 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4450 scratch_class->link_previous_versions(previous_versions());
4451 link_previous_versions(scratch_class);
4452 if (cp_ref->is_shared()) {
4453 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4454 } else {
4455 // We only set clean_previous_versions flag for processing during class
4456 // unloading for non-shared classes.
4457 _should_clean_previous_versions = true;
4458 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4459 }
4460 } // end add_previous_version()
4461
4462 #endif // INCLUDE_JVMTI
4463
4464 Method* InstanceKlass::method_with_idnum(int idnum) {
4465 Method* m = nullptr;
4466 if (idnum < methods()->length()) {
4467 m = methods()->at(idnum);
4468 }
4469 if (m == nullptr || m->method_idnum() != idnum) {
4470 for (int index = 0; index < methods()->length(); ++index) {
4471 m = methods()->at(index);
4472 if (m->method_idnum() == idnum) {
4473 return m;
4474 }
4475 }
4476 // None found, return null for the caller to handle.
4477 return nullptr;
4478 }
4479 return m;
4480 }
4481
4482
4483 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4484 if (idnum >= methods()->length()) {
4485 return nullptr;
4486 }
4487 Method* m = methods()->at(idnum);
4488 if (m != nullptr && m->orig_method_idnum() == idnum) {
4489 return m;
4490 }
4491 // Obsolete method idnum does not match the original idnum
4492 for (int index = 0; index < methods()->length(); ++index) {
4493 m = methods()->at(index);
4494 if (m->orig_method_idnum() == idnum) {
4495 return m;
4496 }
4497 }
4498 // None found, return null for the caller to handle.
4499 return nullptr;
4500 }
4501
4502
4503 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4504 InstanceKlass* holder = get_klass_version(version);
4505 if (holder == nullptr) {
4506 return nullptr; // The version of klass is gone, no method is found
4507 }
4508 Method* method = holder->method_with_orig_idnum(idnum);
4509 return method;
4510 }
4511
4512 #if INCLUDE_JVMTI
4513 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4514 return _cached_class_file;
4515 }
4516
4517 jint InstanceKlass::get_cached_class_file_len() {
4518 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4519 }
4520
4521 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4522 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4523 }
4524 #endif
4525
4526 // Make a step iterating over the class hierarchy under the root class.
4527 // Skips subclasses if requested.
4528 void ClassHierarchyIterator::next() {
4529 assert(_current != nullptr, "required");
4530 if (_visit_subclasses && _current->subklass() != nullptr) {
4531 _current = _current->subklass();
4532 return; // visit next subclass
4533 }
4534 _visit_subclasses = true; // reset
4535 while (_current->next_sibling() == nullptr && _current != _root) {
4536 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4537 }
4538 if (_current == _root) {
4539 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4540 _current = nullptr;
4541 return;
4542 }
4543 _current = _current->next_sibling();
4544 return; // visit next sibling subclass
4545 }