1 /*
2 * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jvm.h"
27 #include "cds/archiveUtils.hpp"
28 #include "cds/classListWriter.hpp"
29 #include "cds/metaspaceShared.hpp"
30 #include "classfile/classFileParser.hpp"
31 #include "classfile/classFileStream.hpp"
32 #include "classfile/classLoader.hpp"
33 #include "classfile/classLoaderData.inline.hpp"
34 #include "classfile/javaClasses.hpp"
35 #include "classfile/moduleEntry.hpp"
36 #include "classfile/resolutionErrors.hpp"
37 #include "classfile/symbolTable.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/oopMapCache.hpp"
49 #include "interpreter/rewriter.hpp"
50 #include "jvmtifiles/jvmti.h"
51 #include "logging/log.hpp"
52 #include "logging/logMessage.hpp"
53 #include "logging/logStream.hpp"
54 #include "memory/allocation.inline.hpp"
55 #include "memory/iterator.inline.hpp"
56 #include "memory/metadataFactory.hpp"
57 #include "memory/metaspaceClosure.hpp"
58 #include "memory/oopFactory.hpp"
59 #include "memory/resourceArea.hpp"
60 #include "memory/universe.hpp"
61 #include "oops/fieldStreams.inline.hpp"
62 #include "oops/constantPool.hpp"
63 #include "oops/instanceClassLoaderKlass.hpp"
64 #include "oops/instanceKlass.inline.hpp"
65 #include "oops/instanceMirrorKlass.hpp"
66 #include "oops/instanceOop.hpp"
67 #include "oops/klass.inline.hpp"
68 #include "oops/method.hpp"
69 #include "oops/oop.inline.hpp"
70 #include "oops/recordComponent.hpp"
71 #include "oops/symbol.hpp"
72 #include "prims/jvmtiExport.hpp"
73 #include "prims/jvmtiRedefineClasses.hpp"
74 #include "prims/jvmtiThreadState.hpp"
75 #include "prims/methodComparator.hpp"
76 #include "runtime/arguments.hpp"
77 #include "runtime/atomic.hpp"
78 #include "runtime/biasedLocking.hpp"
79 #include "runtime/fieldDescriptor.inline.hpp"
80 #include "runtime/handles.inline.hpp"
81 #include "runtime/javaCalls.hpp"
82 #include "runtime/mutexLocker.hpp"
83 #include "runtime/orderAccess.hpp"
84 #include "runtime/reflectionUtils.hpp"
85 #include "runtime/thread.inline.hpp"
86 #include "services/classLoadingService.hpp"
87 #include "services/threadService.hpp"
88 #include "utilities/dtrace.hpp"
89 #include "utilities/events.hpp"
90 #include "utilities/macros.hpp"
91 #include "utilities/stringUtils.hpp"
92 #ifdef COMPILER1
93 #include "c1/c1_Compiler.hpp"
94 #endif
95 #if INCLUDE_JFR
96 #include "jfr/jfrEvents.hpp"
97 #endif
98
99
100 #ifdef DTRACE_ENABLED
101
102
103 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
104 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
105 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
106 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
107 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
108 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
109 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
110 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
111 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
112 { \
113 char* data = NULL; \
114 int len = 0; \
115 Symbol* clss_name = name(); \
116 if (clss_name != NULL) { \
117 data = (char*)clss_name->bytes(); \
118 len = clss_name->utf8_length(); \
119 } \
120 HOTSPOT_CLASS_INITIALIZATION_##type( \
121 data, len, (void*)class_loader(), thread_type); \
122 }
123
124 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
125 { \
126 char* data = NULL; \
127 int len = 0; \
128 Symbol* clss_name = name(); \
129 if (clss_name != NULL) { \
130 data = (char*)clss_name->bytes(); \
131 len = clss_name->utf8_length(); \
132 } \
133 HOTSPOT_CLASS_INITIALIZATION_##type( \
134 data, len, (void*)class_loader(), thread_type, wait); \
135 }
136
137 #else // ndef DTRACE_ENABLED
138
139 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
140 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
141
142 #endif // ndef DTRACE_ENABLED
143
144
is_class_loader(const Symbol * class_name,const ClassFileParser & parser)145 static inline bool is_class_loader(const Symbol* class_name,
146 const ClassFileParser& parser) {
147 assert(class_name != NULL, "invariant");
148
149 if (class_name == vmSymbols::java_lang_ClassLoader()) {
150 return true;
151 }
152
153 if (vmClasses::ClassLoader_klass_loaded()) {
154 const Klass* const super_klass = parser.super_klass();
155 if (super_klass != NULL) {
156 if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
157 return true;
158 }
159 }
160 }
161 return false;
162 }
163
164 // private: called to verify that k is a static member of this nest.
165 // We know that k is an instance class in the same package and hence the
166 // same classloader.
has_nest_member(JavaThread * current,InstanceKlass * k) const167 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
168 assert(!is_hidden(), "unexpected hidden class");
169 if (_nest_members == NULL || _nest_members == Universe::the_empty_short_array()) {
170 if (log_is_enabled(Trace, class, nestmates)) {
171 ResourceMark rm(current);
172 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
173 k->external_name(), this->external_name());
174 }
175 return false;
176 }
177
178 if (log_is_enabled(Trace, class, nestmates)) {
179 ResourceMark rm(current);
180 log_trace(class, nestmates)("Checking nest membership of %s in %s",
181 k->external_name(), this->external_name());
182 }
183
184 // Check for the named class in _nest_members.
185 // We don't resolve, or load, any classes.
186 for (int i = 0; i < _nest_members->length(); i++) {
187 int cp_index = _nest_members->at(i);
188 Symbol* name = _constants->klass_name_at(cp_index);
189 if (name == k->name()) {
190 log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
191 return true;
192 }
193 }
194 log_trace(class, nestmates)("- class is NOT a nest member!");
195 return false;
196 }
197
198 // Called to verify that k is a permitted subclass of this class
has_as_permitted_subclass(const InstanceKlass * k) const199 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k) const {
200 Thread* current = Thread::current();
201 assert(k != NULL, "sanity check");
202 assert(_permitted_subclasses != NULL && _permitted_subclasses != Universe::the_empty_short_array(),
203 "unexpected empty _permitted_subclasses array");
204
205 if (log_is_enabled(Trace, class, sealed)) {
206 ResourceMark rm(current);
207 log_trace(class, sealed)("Checking for permitted subclass of %s in %s",
208 k->external_name(), this->external_name());
209 }
210
211 // Check that the class and its super are in the same module.
212 if (k->module() != this->module()) {
213 ResourceMark rm(current);
214 log_trace(class, sealed)("Check failed for same module of permitted subclass %s and sealed class %s",
215 k->external_name(), this->external_name());
216 return false;
217 }
218
219 if (!k->is_public() && !is_same_class_package(k)) {
220 ResourceMark rm(current);
221 log_trace(class, sealed)("Check failed, subclass %s not public and not in the same package as sealed class %s",
222 k->external_name(), this->external_name());
223 return false;
224 }
225
226 for (int i = 0; i < _permitted_subclasses->length(); i++) {
227 int cp_index = _permitted_subclasses->at(i);
228 Symbol* name = _constants->klass_name_at(cp_index);
229 if (name == k->name()) {
230 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
231 return true;
232 }
233 }
234 log_trace(class, sealed)("- class is NOT a permitted subclass!");
235 return false;
236 }
237
238 // Return nest-host class, resolving, validating and saving it if needed.
239 // In cases where this is called from a thread that cannot do classloading
240 // (such as a native JIT thread) then we simply return NULL, which in turn
241 // causes the access check to return false. Such code will retry the access
242 // from a more suitable environment later. Otherwise the _nest_host is always
243 // set once this method returns.
244 // Any errors from nest-host resolution must be preserved so they can be queried
245 // from higher-level access checking code, and reported as part of access checking
246 // exceptions.
247 // VirtualMachineErrors are propagated with a NULL return.
248 // Under any conditions where the _nest_host can be set to non-NULL the resulting
249 // value of it and, if applicable, the nest host resolution/validation error,
250 // are idempotent.
nest_host(TRAPS)251 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
252 InstanceKlass* nest_host_k = _nest_host;
253 if (nest_host_k != NULL) {
254 return nest_host_k;
255 }
256
257 ResourceMark rm(THREAD);
258
259 // need to resolve and save our nest-host class.
260 if (_nest_host_index != 0) { // we have a real nest_host
261 // Before trying to resolve check if we're in a suitable context
262 bool can_resolve = THREAD->can_call_java();
263 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
264 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
265 this->external_name());
266 return NULL; // sentinel to say "try again from a different context"
267 }
268
269 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
270 this->external_name(),
271 _constants->klass_name_at(_nest_host_index)->as_C_string());
272
273 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
274 if (HAS_PENDING_EXCEPTION) {
275 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
276 return NULL; // propagate VMEs
277 }
278 stringStream ss;
279 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
280 ss.print("Nest host resolution of %s with host %s failed: ",
281 this->external_name(), target_host_class);
282 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
283 const char* msg = ss.as_string(true /* on C-heap */);
284 constantPoolHandle cph(THREAD, constants());
285 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
286 CLEAR_PENDING_EXCEPTION;
287
288 log_trace(class, nestmates)("%s", msg);
289 } else {
290 // A valid nest-host is an instance class in the current package that lists this
291 // class as a nest member. If any of these conditions are not met the class is
292 // its own nest-host.
293 const char* error = NULL;
294
295 // JVMS 5.4.4 indicates package check comes first
296 if (is_same_class_package(k)) {
297 // Now check actual membership. We can't be a member if our "host" is
298 // not an instance class.
299 if (k->is_instance_klass()) {
300 nest_host_k = InstanceKlass::cast(k);
301 bool is_member = nest_host_k->has_nest_member(THREAD, this);
302 if (is_member) {
303 _nest_host = nest_host_k; // save resolved nest-host value
304
305 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
306 this->external_name(), k->external_name());
307 return nest_host_k;
308 } else {
309 error = "current type is not listed as a nest member";
310 }
311 } else {
312 error = "host is not an instance class";
313 }
314 } else {
315 error = "types are in different packages";
316 }
317
318 // something went wrong, so record what and log it
319 {
320 stringStream ss;
321 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
322 this->external_name(),
323 this->class_loader_data()->loader_name_and_id(),
324 k->external_name(),
325 k->class_loader_data()->loader_name_and_id(),
326 error);
327 const char* msg = ss.as_string(true /* on C-heap */);
328 constantPoolHandle cph(THREAD, constants());
329 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
330 log_trace(class, nestmates)("%s", msg);
331 }
332 }
333 } else {
334 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
335 this->external_name());
336 }
337
338 // Either not in an explicit nest, or else an error occurred, so
339 // the nest-host is set to `this`. Any thread that sees this assignment
340 // will also see any setting of nest_host_error(), if applicable.
341 return (_nest_host = this);
342 }
343
344 // Dynamic nest member support: set this class's nest host to the given class.
345 // This occurs as part of the class definition, as soon as the instanceKlass
346 // has been created and doesn't require further resolution. The code:
347 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
348 // results in:
349 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
350 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
351 // We also know the "host" is a valid nest-host in the same package so we can
352 // assert some of those facts.
set_nest_host(InstanceKlass * host)353 void InstanceKlass::set_nest_host(InstanceKlass* host) {
354 assert(is_hidden(), "must be a hidden class");
355 assert(host != NULL, "NULL nest host specified");
356 assert(_nest_host == NULL, "current class has resolved nest-host");
357 assert(nest_host_error() == NULL, "unexpected nest host resolution error exists: %s",
358 nest_host_error());
359 assert((host->_nest_host == NULL && host->_nest_host_index == 0) ||
360 (host->_nest_host == host), "proposed host is not a valid nest-host");
361 // Can't assert this as package is not set yet:
362 // assert(is_same_class_package(host), "proposed host is in wrong package");
363
364 if (log_is_enabled(Trace, class, nestmates)) {
365 ResourceMark rm;
366 const char* msg = "";
367 // a hidden class does not expect a statically defined nest-host
368 if (_nest_host_index > 0) {
369 msg = "(the NestHost attribute in the current class is ignored)";
370 } else if (_nest_members != NULL && _nest_members != Universe::the_empty_short_array()) {
371 msg = "(the NestMembers attribute in the current class is ignored)";
372 }
373 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
374 this->external_name(),
375 host->external_name(),
376 msg);
377 }
378 // set dynamic nest host
379 _nest_host = host;
380 // Record dependency to keep nest host from being unloaded before this class.
381 ClassLoaderData* this_key = class_loader_data();
382 this_key->record_dependency(host);
383 }
384
385 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
386 // or we are k's nest_host - all of which is covered by comparing the two
387 // resolved_nest_hosts.
388 // Any exceptions (i.e. VMEs) are propagated.
has_nestmate_access_to(InstanceKlass * k,TRAPS)389 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
390
391 assert(this != k, "this should be handled by higher-level code");
392
393 // Per JVMS 5.4.4 we first resolve and validate the current class, then
394 // the target class k.
395
396 InstanceKlass* cur_host = nest_host(CHECK_false);
397 if (cur_host == NULL) {
398 return false;
399 }
400
401 Klass* k_nest_host = k->nest_host(CHECK_false);
402 if (k_nest_host == NULL) {
403 return false;
404 }
405
406 bool access = (cur_host == k_nest_host);
407
408 ResourceMark rm(THREAD);
409 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
410 this->external_name(),
411 access ? "" : "NOT ",
412 k->external_name());
413 return access;
414 }
415
nest_host_error()416 const char* InstanceKlass::nest_host_error() {
417 if (_nest_host_index == 0) {
418 return NULL;
419 } else {
420 constantPoolHandle cph(Thread::current(), constants());
421 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
422 }
423 }
424
allocate_instance_klass(const ClassFileParser & parser,TRAPS)425 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
426 const int size = InstanceKlass::size(parser.vtable_size(),
427 parser.itable_size(),
428 nonstatic_oop_map_size(parser.total_oop_map_count()),
429 parser.is_interface());
430
431 const Symbol* const class_name = parser.class_name();
432 assert(class_name != NULL, "invariant");
433 ClassLoaderData* loader_data = parser.loader_data();
434 assert(loader_data != NULL, "invariant");
435
436 InstanceKlass* ik;
437
438 // Allocation
439 if (REF_NONE == parser.reference_type()) {
440 if (class_name == vmSymbols::java_lang_Class()) {
441 // mirror
442 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
443 }
444 else if (is_class_loader(class_name, parser)) {
445 // class loader
446 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
447 } else {
448 // normal
449 ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_kind_other);
450 }
451 } else {
452 // reference
453 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
454 }
455
456 // Check for pending exception before adding to the loader data and incrementing
457 // class count. Can get OOM here.
458 if (HAS_PENDING_EXCEPTION) {
459 return NULL;
460 }
461
462 return ik;
463 }
464
465
466 // copy method ordering from resource area to Metaspace
copy_method_ordering(const intArray * m,TRAPS)467 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
468 if (m != NULL) {
469 // allocate a new array and copy contents (memcpy?)
470 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
471 for (int i = 0; i < m->length(); i++) {
472 _method_ordering->at_put(i, m->at(i));
473 }
474 } else {
475 _method_ordering = Universe::the_empty_int_array();
476 }
477 }
478
479 // create a new array of vtable_indices for default methods
create_new_default_vtable_indices(int len,TRAPS)480 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
481 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
482 assert(default_vtable_indices() == NULL, "only create once");
483 set_default_vtable_indices(vtable_indices);
484 return vtable_indices;
485 }
486
InstanceKlass(const ClassFileParser & parser,unsigned kind,KlassID id)487 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind, KlassID id) :
488 Klass(id),
489 _nest_members(NULL),
490 _nest_host(NULL),
491 _permitted_subclasses(NULL),
492 _record_components(NULL),
493 _static_field_size(parser.static_field_size()),
494 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
495 _itable_len(parser.itable_size()),
496 _nest_host_index(0),
497 _init_state(allocated),
498 _reference_type(parser.reference_type()),
499 _init_thread(NULL)
500 {
501 set_vtable_length(parser.vtable_size());
502 set_kind(kind);
503 set_access_flags(parser.access_flags());
504 if (parser.is_hidden()) set_is_hidden();
505 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
506 false));
507
508 assert(NULL == _methods, "underlying memory not zeroed?");
509 assert(is_instance_klass(), "is layout incorrect?");
510 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
511
512 // Set biased locking bit for all instances of this class; it will be
513 // cleared if revocation occurs too often for this type
514 if (UseBiasedLocking && BiasedLocking::enabled()) {
515 set_prototype_header(markWord::biased_locking_prototype());
516 }
517 }
518
deallocate_methods(ClassLoaderData * loader_data,Array<Method * > * methods)519 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
520 Array<Method*>* methods) {
521 if (methods != NULL && methods != Universe::the_empty_method_array() &&
522 !methods->is_shared()) {
523 for (int i = 0; i < methods->length(); i++) {
524 Method* method = methods->at(i);
525 if (method == NULL) continue; // maybe null if error processing
526 // Only want to delete methods that are not executing for RedefineClasses.
527 // The previous version will point to them so they're not totally dangling
528 assert (!method->on_stack(), "shouldn't be called with methods on stack");
529 MetadataFactory::free_metadata(loader_data, method);
530 }
531 MetadataFactory::free_array<Method*>(loader_data, methods);
532 }
533 }
534
deallocate_interfaces(ClassLoaderData * loader_data,const Klass * super_klass,Array<InstanceKlass * > * local_interfaces,Array<InstanceKlass * > * transitive_interfaces)535 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
536 const Klass* super_klass,
537 Array<InstanceKlass*>* local_interfaces,
538 Array<InstanceKlass*>* transitive_interfaces) {
539 // Only deallocate transitive interfaces if not empty, same as super class
540 // or same as local interfaces. See code in parseClassFile.
541 Array<InstanceKlass*>* ti = transitive_interfaces;
542 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
543 // check that the interfaces don't come from super class
544 Array<InstanceKlass*>* sti = (super_klass == NULL) ? NULL :
545 InstanceKlass::cast(super_klass)->transitive_interfaces();
546 if (ti != sti && ti != NULL && !ti->is_shared()) {
547 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
548 }
549 }
550
551 // local interfaces can be empty
552 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
553 local_interfaces != NULL && !local_interfaces->is_shared()) {
554 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
555 }
556 }
557
deallocate_record_components(ClassLoaderData * loader_data,Array<RecordComponent * > * record_components)558 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
559 Array<RecordComponent*>* record_components) {
560 if (record_components != NULL && !record_components->is_shared()) {
561 for (int i = 0; i < record_components->length(); i++) {
562 RecordComponent* record_component = record_components->at(i);
563 MetadataFactory::free_metadata(loader_data, record_component);
564 }
565 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
566 }
567 }
568
569 // This function deallocates the metadata and C heap pointers that the
570 // InstanceKlass points to.
deallocate_contents(ClassLoaderData * loader_data)571 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
572
573 // Orphan the mirror first, CMS thinks it's still live.
574 if (java_mirror() != NULL) {
575 java_lang_Class::set_klass(java_mirror(), NULL);
576 }
577
578 // Also remove mirror from handles
579 loader_data->remove_handle(_java_mirror);
580
581 // Need to take this class off the class loader data list.
582 loader_data->remove_class(this);
583
584 // The array_klass for this class is created later, after error handling.
585 // For class redefinition, we keep the original class so this scratch class
586 // doesn't have an array class. Either way, assert that there is nothing
587 // to deallocate.
588 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
589
590 // Release C heap allocated data that this points to, which includes
591 // reference counting symbol names.
592 release_C_heap_structures_internal();
593
594 deallocate_methods(loader_data, methods());
595 set_methods(NULL);
596
597 deallocate_record_components(loader_data, record_components());
598 set_record_components(NULL);
599
600 if (method_ordering() != NULL &&
601 method_ordering() != Universe::the_empty_int_array() &&
602 !method_ordering()->is_shared()) {
603 MetadataFactory::free_array<int>(loader_data, method_ordering());
604 }
605 set_method_ordering(NULL);
606
607 // default methods can be empty
608 if (default_methods() != NULL &&
609 default_methods() != Universe::the_empty_method_array() &&
610 !default_methods()->is_shared()) {
611 MetadataFactory::free_array<Method*>(loader_data, default_methods());
612 }
613 // Do NOT deallocate the default methods, they are owned by superinterfaces.
614 set_default_methods(NULL);
615
616 // default methods vtable indices can be empty
617 if (default_vtable_indices() != NULL &&
618 !default_vtable_indices()->is_shared()) {
619 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
620 }
621 set_default_vtable_indices(NULL);
622
623
624 // This array is in Klass, but remove it with the InstanceKlass since
625 // this place would be the only caller and it can share memory with transitive
626 // interfaces.
627 if (secondary_supers() != NULL &&
628 secondary_supers() != Universe::the_empty_klass_array() &&
629 // see comments in compute_secondary_supers about the following cast
630 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
631 !secondary_supers()->is_shared()) {
632 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
633 }
634 set_secondary_supers(NULL);
635
636 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
637 set_transitive_interfaces(NULL);
638 set_local_interfaces(NULL);
639
640 if (fields() != NULL && !fields()->is_shared()) {
641 MetadataFactory::free_array<jushort>(loader_data, fields());
642 }
643 set_fields(NULL, 0);
644
645 // If a method from a redefined class is using this constant pool, don't
646 // delete it, yet. The new class's previous version will point to this.
647 if (constants() != NULL) {
648 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
649 if (!constants()->is_shared()) {
650 MetadataFactory::free_metadata(loader_data, constants());
651 }
652 // Delete any cached resolution errors for the constant pool
653 SystemDictionary::delete_resolution_error(constants());
654
655 set_constants(NULL);
656 }
657
658 if (inner_classes() != NULL &&
659 inner_classes() != Universe::the_empty_short_array() &&
660 !inner_classes()->is_shared()) {
661 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
662 }
663 set_inner_classes(NULL);
664
665 if (nest_members() != NULL &&
666 nest_members() != Universe::the_empty_short_array() &&
667 !nest_members()->is_shared()) {
668 MetadataFactory::free_array<jushort>(loader_data, nest_members());
669 }
670 set_nest_members(NULL);
671
672 if (permitted_subclasses() != NULL &&
673 permitted_subclasses() != Universe::the_empty_short_array() &&
674 !permitted_subclasses()->is_shared()) {
675 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
676 }
677 set_permitted_subclasses(NULL);
678
679 // We should deallocate the Annotations instance if it's not in shared spaces.
680 if (annotations() != NULL && !annotations()->is_shared()) {
681 MetadataFactory::free_metadata(loader_data, annotations());
682 }
683 set_annotations(NULL);
684
685 if (Arguments::is_dumping_archive()) {
686 SystemDictionaryShared::remove_dumptime_info(this);
687 }
688 }
689
is_record() const690 bool InstanceKlass::is_record() const {
691 return _record_components != NULL &&
692 is_final() &&
693 java_super() == vmClasses::Record_klass();
694 }
695
is_sealed() const696 bool InstanceKlass::is_sealed() const {
697 return _permitted_subclasses != NULL &&
698 _permitted_subclasses != Universe::the_empty_short_array();
699 }
700
should_be_initialized() const701 bool InstanceKlass::should_be_initialized() const {
702 return !is_initialized();
703 }
704
itable() const705 klassItable InstanceKlass::itable() const {
706 return klassItable(const_cast<InstanceKlass*>(this));
707 }
708
eager_initialize(Thread * thread)709 void InstanceKlass::eager_initialize(Thread *thread) {
710 if (!EagerInitialization) return;
711
712 if (this->is_not_initialized()) {
713 // abort if the the class has a class initializer
714 if (this->class_initializer() != NULL) return;
715
716 // abort if it is java.lang.Object (initialization is handled in genesis)
717 Klass* super_klass = super();
718 if (super_klass == NULL) return;
719
720 // abort if the super class should be initialized
721 if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
722
723 // call body to expose the this pointer
724 eager_initialize_impl();
725 }
726 }
727
728 // JVMTI spec thinks there are signers and protection domain in the
729 // instanceKlass. These accessors pretend these fields are there.
730 // The hprof specification also thinks these fields are in InstanceKlass.
protection_domain() const731 oop InstanceKlass::protection_domain() const {
732 // return the protection_domain from the mirror
733 return java_lang_Class::protection_domain(java_mirror());
734 }
735
736 // To remove these from requires an incompatible change and CCC request.
signers() const737 objArrayOop InstanceKlass::signers() const {
738 // return the signers from the mirror
739 return java_lang_Class::signers(java_mirror());
740 }
741
init_lock() const742 oop InstanceKlass::init_lock() const {
743 // return the init lock from the mirror
744 oop lock = java_lang_Class::init_lock(java_mirror());
745 // Prevent reordering with any access of initialization state
746 OrderAccess::loadload();
747 assert(lock != NULL || !is_not_initialized(), // initialized or in_error state
748 "only fully initialized state can have a null lock");
749 return lock;
750 }
751
752 // Set the initialization lock to null so the object can be GC'ed. Any racing
753 // threads to get this lock will see a null lock and will not lock.
754 // That's okay because they all check for initialized state after getting
755 // the lock and return.
fence_and_clear_init_lock()756 void InstanceKlass::fence_and_clear_init_lock() {
757 // make sure previous stores are all done, notably the init_state.
758 OrderAccess::storestore();
759 java_lang_Class::clear_init_lock(java_mirror());
760 assert(!is_not_initialized(), "class must be initialized now");
761 }
762
eager_initialize_impl()763 void InstanceKlass::eager_initialize_impl() {
764 EXCEPTION_MARK;
765 HandleMark hm(THREAD);
766 Handle h_init_lock(THREAD, init_lock());
767 ObjectLocker ol(h_init_lock, THREAD);
768
769 // abort if someone beat us to the initialization
770 if (!is_not_initialized()) return; // note: not equivalent to is_initialized()
771
772 ClassState old_state = init_state();
773 link_class_impl(THREAD);
774 if (HAS_PENDING_EXCEPTION) {
775 CLEAR_PENDING_EXCEPTION;
776 // Abort if linking the class throws an exception.
777
778 // Use a test to avoid redundantly resetting the state if there's
779 // no change. Set_init_state() asserts that state changes make
780 // progress, whereas here we might just be spinning in place.
781 if (old_state != _init_state)
782 set_init_state(old_state);
783 } else {
784 // linking successfull, mark class as initialized
785 set_init_state(fully_initialized);
786 fence_and_clear_init_lock();
787 // trace
788 if (log_is_enabled(Info, class, init)) {
789 ResourceMark rm(THREAD);
790 log_info(class, init)("[Initialized %s without side effects]", external_name());
791 }
792 }
793 }
794
795
796 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
797 // process. The step comments refers to the procedure described in that section.
798 // Note: implementation moved to static method to expose the this pointer.
initialize(TRAPS)799 void InstanceKlass::initialize(TRAPS) {
800 if (this->should_be_initialized()) {
801 initialize_impl(CHECK);
802 // Note: at this point the class may be initialized
803 // OR it may be in the state of being initialized
804 // in case of recursive initialization!
805 } else {
806 assert(is_initialized(), "sanity check");
807 }
808 }
809
810
verify_code(TRAPS)811 bool InstanceKlass::verify_code(TRAPS) {
812 // 1) Verify the bytecodes
813 return Verifier::verify(this, should_verify_class(), THREAD);
814 }
815
link_class(TRAPS)816 void InstanceKlass::link_class(TRAPS) {
817 assert(is_loaded(), "must be loaded");
818 if (!is_linked()) {
819 link_class_impl(CHECK);
820 }
821 }
822
823 // Called to verify that a class can link during initialization, without
824 // throwing a VerifyError.
link_class_or_fail(TRAPS)825 bool InstanceKlass::link_class_or_fail(TRAPS) {
826 assert(is_loaded(), "must be loaded");
827 if (!is_linked()) {
828 link_class_impl(CHECK_false);
829 }
830 return is_linked();
831 }
832
link_class_impl(TRAPS)833 bool InstanceKlass::link_class_impl(TRAPS) {
834 if (DumpSharedSpaces && SystemDictionaryShared::has_class_failed_verification(this)) {
835 // This is for CDS dumping phase only -- we use the in_error_state to indicate that
836 // the class has failed verification. Throwing the NoClassDefFoundError here is just
837 // a convenient way to stop repeat attempts to verify the same (bad) class.
838 //
839 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
840 // if we are executing Java code. This is not a problem for CDS dumping phase since
841 // it doesn't execute any Java code.
842 ResourceMark rm(THREAD);
843 Exceptions::fthrow(THREAD_AND_LOCATION,
844 vmSymbols::java_lang_NoClassDefFoundError(),
845 "Class %s, or one of its supertypes, failed class initialization",
846 external_name());
847 return false;
848 }
849 // return if already verified
850 if (is_linked()) {
851 return true;
852 }
853
854 // Timing
855 // timer handles recursion
856 JavaThread* jt = THREAD;
857
858 // link super class before linking this class
859 Klass* super_klass = super();
860 if (super_klass != NULL) {
861 if (super_klass->is_interface()) { // check if super class is an interface
862 ResourceMark rm(THREAD);
863 Exceptions::fthrow(
864 THREAD_AND_LOCATION,
865 vmSymbols::java_lang_IncompatibleClassChangeError(),
866 "class %s has interface %s as super class",
867 external_name(),
868 super_klass->external_name()
869 );
870 return false;
871 }
872
873 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
874 ik_super->link_class_impl(CHECK_false);
875 }
876
877 // link all interfaces implemented by this class before linking this class
878 Array<InstanceKlass*>* interfaces = local_interfaces();
879 int num_interfaces = interfaces->length();
880 for (int index = 0; index < num_interfaces; index++) {
881 InstanceKlass* interk = interfaces->at(index);
882 interk->link_class_impl(CHECK_false);
883 }
884
885 // in case the class is linked in the process of linking its superclasses
886 if (is_linked()) {
887 return true;
888 }
889
890 // trace only the link time for this klass that includes
891 // the verification time
892 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
893 ClassLoader::perf_class_link_selftime(),
894 ClassLoader::perf_classes_linked(),
895 jt->get_thread_stat()->perf_recursion_counts_addr(),
896 jt->get_thread_stat()->perf_timers_addr(),
897 PerfClassTraceTime::CLASS_LINK);
898
899 // verification & rewriting
900 {
901 HandleMark hm(THREAD);
902 Handle h_init_lock(THREAD, init_lock());
903 ObjectLocker ol(h_init_lock, jt);
904 // rewritten will have been set if loader constraint error found
905 // on an earlier link attempt
906 // don't verify or rewrite if already rewritten
907 //
908
909 if (!is_linked()) {
910 if (!is_rewritten()) {
911 {
912 bool verify_ok = verify_code(THREAD);
913 if (!verify_ok) {
914 return false;
915 }
916 }
917
918 // Just in case a side-effect of verify linked this class already
919 // (which can sometimes happen since the verifier loads classes
920 // using custom class loaders, which are free to initialize things)
921 if (is_linked()) {
922 return true;
923 }
924
925 // also sets rewritten
926 rewrite_class(CHECK_false);
927 } else if (is_shared()) {
928 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
929 }
930
931 // relocate jsrs and link methods after they are all rewritten
932 link_methods(CHECK_false);
933
934 // Initialize the vtable and interface table after
935 // methods have been rewritten since rewrite may
936 // fabricate new Method*s.
937 // also does loader constraint checking
938 //
939 // initialize_vtable and initialize_itable need to be rerun
940 // for a shared class if
941 // 1) the class is loaded by custom class loader or
942 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints
943 bool need_init_table = true;
944 if (is_shared() && SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
945 need_init_table = false;
946 }
947 if (need_init_table) {
948 vtable().initialize_vtable_and_check_constraints(CHECK_false);
949 itable().initialize_itable_and_check_constraints(CHECK_false);
950 }
951 #ifdef ASSERT
952 vtable().verify(tty, true);
953 // In case itable verification is ever added.
954 // itable().verify(tty, true);
955 #endif
956 if (UseVtableBasedCHA) {
957 MutexLocker ml(THREAD, Compile_lock);
958 set_init_state(linked);
959
960 // Now flush all code that assume the class is not linked.
961 if (Universe::is_fully_initialized()) {
962 CodeCache::flush_dependents_on(this);
963 }
964 } else {
965 set_init_state(linked);
966 }
967 if (JvmtiExport::should_post_class_prepare()) {
968 JvmtiExport::post_class_prepare(THREAD, this);
969 }
970 }
971 }
972 return true;
973 }
974
975 // Rewrite the byte codes of all of the methods of a class.
976 // The rewriter must be called exactly once. Rewriting must happen after
977 // verification but before the first method of the class is executed.
rewrite_class(TRAPS)978 void InstanceKlass::rewrite_class(TRAPS) {
979 assert(is_loaded(), "must be loaded");
980 if (is_rewritten()) {
981 assert(is_shared(), "rewriting an unshared class?");
982 return;
983 }
984 Rewriter::rewrite(this, CHECK);
985 set_rewritten();
986 }
987
988 // Now relocate and link method entry points after class is rewritten.
989 // This is outside is_rewritten flag. In case of an exception, it can be
990 // executed more than once.
link_methods(TRAPS)991 void InstanceKlass::link_methods(TRAPS) {
992 int len = methods()->length();
993 for (int i = len-1; i >= 0; i--) {
994 methodHandle m(THREAD, methods()->at(i));
995
996 // Set up method entry points for compiler and interpreter .
997 m->link_method(m, CHECK);
998 }
999 }
1000
1001 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
initialize_super_interfaces(TRAPS)1002 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1003 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1004 for (int i = 0; i < local_interfaces()->length(); ++i) {
1005 InstanceKlass* ik = local_interfaces()->at(i);
1006
1007 // Initialization is depth first search ie. we start with top of the inheritance tree
1008 // has_nonstatic_concrete_methods drives searching superinterfaces since it
1009 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1010 if (ik->has_nonstatic_concrete_methods()) {
1011 ik->initialize_super_interfaces(CHECK);
1012 }
1013
1014 // Only initialize() interfaces that "declare" concrete methods.
1015 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1016 ik->initialize(CHECK);
1017 }
1018 }
1019 }
1020
initialize_impl(TRAPS)1021 void InstanceKlass::initialize_impl(TRAPS) {
1022 HandleMark hm(THREAD);
1023
1024 // Make sure klass is linked (verified) before initialization
1025 // A class could already be verified, since it has been reflected upon.
1026 link_class(CHECK);
1027
1028 DTRACE_CLASSINIT_PROBE(required, -1);
1029
1030 bool wait = false;
1031
1032 JavaThread* jt = THREAD;
1033
1034 // refer to the JVM book page 47 for description of steps
1035 // Step 1
1036 {
1037 Handle h_init_lock(THREAD, init_lock());
1038 ObjectLocker ol(h_init_lock, jt);
1039
1040 // Step 2
1041 // If we were to use wait() instead of waitInterruptibly() then
1042 // we might end up throwing IE from link/symbol resolution sites
1043 // that aren't expected to throw. This would wreak havoc. See 6320309.
1044 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1045 wait = true;
1046 jt->set_class_to_be_initialized(this);
1047 ol.wait_uninterruptibly(jt);
1048 jt->set_class_to_be_initialized(NULL);
1049 }
1050
1051 // Step 3
1052 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1053 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1054 return;
1055 }
1056
1057 // Step 4
1058 if (is_initialized()) {
1059 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1060 return;
1061 }
1062
1063 // Step 5
1064 if (is_in_error_state()) {
1065 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1066 ResourceMark rm(THREAD);
1067 const char* desc = "Could not initialize class ";
1068 const char* className = external_name();
1069 size_t msglen = strlen(desc) + strlen(className) + 1;
1070 char* message = NEW_RESOURCE_ARRAY(char, msglen);
1071 if (NULL == message) {
1072 // Out of memory: can't create detailed error message
1073 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
1074 } else {
1075 jio_snprintf(message, msglen, "%s%s", desc, className);
1076 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
1077 }
1078 }
1079
1080 // Step 6
1081 set_init_state(being_initialized);
1082 set_init_thread(jt);
1083 }
1084
1085 // Step 7
1086 // Next, if C is a class rather than an interface, initialize it's super class and super
1087 // interfaces.
1088 if (!is_interface()) {
1089 Klass* super_klass = super();
1090 if (super_klass != NULL && super_klass->should_be_initialized()) {
1091 super_klass->initialize(THREAD);
1092 }
1093 // If C implements any interface that declares a non-static, concrete method,
1094 // the initialization of C triggers initialization of its super interfaces.
1095 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1096 // having a superinterface that declares, non-static, concrete methods
1097 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1098 initialize_super_interfaces(THREAD);
1099 }
1100
1101 // If any exceptions, complete abruptly, throwing the same exception as above.
1102 if (HAS_PENDING_EXCEPTION) {
1103 Handle e(THREAD, PENDING_EXCEPTION);
1104 CLEAR_PENDING_EXCEPTION;
1105 {
1106 EXCEPTION_MARK;
1107 // Locks object, set state, and notify all waiting threads
1108 set_initialization_state_and_notify(initialization_error, THREAD);
1109 CLEAR_PENDING_EXCEPTION;
1110 }
1111 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1112 THROW_OOP(e());
1113 }
1114 }
1115
1116
1117 // Step 8
1118 {
1119 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1120 if (class_initializer() != NULL) {
1121 // Timer includes any side effects of class initialization (resolution,
1122 // etc), but not recursive entry into call_class_initializer().
1123 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1124 ClassLoader::perf_class_init_selftime(),
1125 ClassLoader::perf_classes_inited(),
1126 jt->get_thread_stat()->perf_recursion_counts_addr(),
1127 jt->get_thread_stat()->perf_timers_addr(),
1128 PerfClassTraceTime::CLASS_CLINIT);
1129 call_class_initializer(THREAD);
1130 } else {
1131 // The elapsed time is so small it's not worth counting.
1132 if (UsePerfData) {
1133 ClassLoader::perf_classes_inited()->inc();
1134 }
1135 call_class_initializer(THREAD);
1136 }
1137 }
1138
1139 // Step 9
1140 if (!HAS_PENDING_EXCEPTION) {
1141 set_initialization_state_and_notify(fully_initialized, CHECK);
1142 {
1143 debug_only(vtable().verify(tty, true);)
1144 }
1145 }
1146 else {
1147 // Step 10 and 11
1148 Handle e(THREAD, PENDING_EXCEPTION);
1149 CLEAR_PENDING_EXCEPTION;
1150 // JVMTI has already reported the pending exception
1151 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1152 JvmtiExport::clear_detected_exception(jt);
1153 {
1154 EXCEPTION_MARK;
1155 set_initialization_state_and_notify(initialization_error, THREAD);
1156 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1157 // JVMTI has already reported the pending exception
1158 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1159 JvmtiExport::clear_detected_exception(jt);
1160 }
1161 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1162 if (e->is_a(vmClasses::Error_klass())) {
1163 THROW_OOP(e());
1164 } else {
1165 JavaCallArguments args(e);
1166 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1167 vmSymbols::throwable_void_signature(),
1168 &args);
1169 }
1170 }
1171 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1172 }
1173
1174
set_initialization_state_and_notify(ClassState state,TRAPS)1175 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1176 Handle h_init_lock(THREAD, init_lock());
1177 if (h_init_lock() != NULL) {
1178 ObjectLocker ol(h_init_lock, THREAD);
1179 set_init_thread(NULL); // reset _init_thread before changing _init_state
1180 set_init_state(state);
1181 fence_and_clear_init_lock();
1182 ol.notify_all(CHECK);
1183 } else {
1184 assert(h_init_lock() != NULL, "The initialization state should never be set twice");
1185 set_init_thread(NULL); // reset _init_thread before changing _init_state
1186 set_init_state(state);
1187 }
1188 }
1189
implementor() const1190 InstanceKlass* InstanceKlass::implementor() const {
1191 InstanceKlass* volatile* ik = adr_implementor();
1192 if (ik == NULL) {
1193 return NULL;
1194 } else {
1195 // This load races with inserts, and therefore needs acquire.
1196 InstanceKlass* ikls = Atomic::load_acquire(ik);
1197 if (ikls != NULL && !ikls->is_loader_alive()) {
1198 return NULL; // don't return unloaded class
1199 } else {
1200 return ikls;
1201 }
1202 }
1203 }
1204
1205
set_implementor(InstanceKlass * ik)1206 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1207 assert_locked_or_safepoint(Compile_lock);
1208 assert(is_interface(), "not interface");
1209 InstanceKlass* volatile* addr = adr_implementor();
1210 assert(addr != NULL, "null addr");
1211 if (addr != NULL) {
1212 Atomic::release_store(addr, ik);
1213 }
1214 }
1215
nof_implementors() const1216 int InstanceKlass::nof_implementors() const {
1217 InstanceKlass* ik = implementor();
1218 if (ik == NULL) {
1219 return 0;
1220 } else if (ik != this) {
1221 return 1;
1222 } else {
1223 return 2;
1224 }
1225 }
1226
1227 // The embedded _implementor field can only record one implementor.
1228 // When there are more than one implementors, the _implementor field
1229 // is set to the interface Klass* itself. Following are the possible
1230 // values for the _implementor field:
1231 // NULL - no implementor
1232 // implementor Klass* - one implementor
1233 // self - more than one implementor
1234 //
1235 // The _implementor field only exists for interfaces.
add_implementor(InstanceKlass * ik)1236 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1237 if (Universe::is_fully_initialized()) {
1238 assert_lock_strong(Compile_lock);
1239 }
1240 assert(is_interface(), "not interface");
1241 // Filter out my subinterfaces.
1242 // (Note: Interfaces are never on the subklass list.)
1243 if (ik->is_interface()) return;
1244
1245 // Filter out subclasses whose supers already implement me.
1246 // (Note: CHA must walk subclasses of direct implementors
1247 // in order to locate indirect implementors.)
1248 InstanceKlass* super_ik = ik->java_super();
1249 if (super_ik != NULL && super_ik->implements_interface(this))
1250 // We only need to check one immediate superclass, since the
1251 // implements_interface query looks at transitive_interfaces.
1252 // Any supers of the super have the same (or fewer) transitive_interfaces.
1253 return;
1254
1255 InstanceKlass* iklass = implementor();
1256 if (iklass == NULL) {
1257 set_implementor(ik);
1258 } else if (iklass != this && iklass != ik) {
1259 // There is already an implementor. Use itself as an indicator of
1260 // more than one implementors.
1261 set_implementor(this);
1262 }
1263
1264 // The implementor also implements the transitive_interfaces
1265 for (int index = 0; index < local_interfaces()->length(); index++) {
1266 local_interfaces()->at(index)->add_implementor(ik);
1267 }
1268 }
1269
init_implementor()1270 void InstanceKlass::init_implementor() {
1271 if (is_interface()) {
1272 set_implementor(NULL);
1273 }
1274 }
1275
1276
process_interfaces()1277 void InstanceKlass::process_interfaces() {
1278 // link this class into the implementors list of every interface it implements
1279 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1280 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1281 InstanceKlass* interf = local_interfaces()->at(i);
1282 assert(interf->is_interface(), "expected interface");
1283 interf->add_implementor(this);
1284 }
1285 }
1286
can_be_primary_super_slow() const1287 bool InstanceKlass::can_be_primary_super_slow() const {
1288 if (is_interface())
1289 return false;
1290 else
1291 return Klass::can_be_primary_super_slow();
1292 }
1293
compute_secondary_supers(int num_extra_slots,Array<InstanceKlass * > * transitive_interfaces)1294 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1295 Array<InstanceKlass*>* transitive_interfaces) {
1296 // The secondaries are the implemented interfaces.
1297 Array<InstanceKlass*>* interfaces = transitive_interfaces;
1298 int num_secondaries = num_extra_slots + interfaces->length();
1299 if (num_secondaries == 0) {
1300 // Must share this for correct bootstrapping!
1301 set_secondary_supers(Universe::the_empty_klass_array());
1302 return NULL;
1303 } else if (num_extra_slots == 0) {
1304 // The secondary super list is exactly the same as the transitive interfaces, so
1305 // let's use it instead of making a copy.
1306 // Redefine classes has to be careful not to delete this!
1307 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1308 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1309 set_secondary_supers((Array<Klass*>*)(address)interfaces);
1310 return NULL;
1311 } else {
1312 // Copy transitive interfaces to a temporary growable array to be constructed
1313 // into the secondary super list with extra slots.
1314 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1315 for (int i = 0; i < interfaces->length(); i++) {
1316 secondaries->push(interfaces->at(i));
1317 }
1318 return secondaries;
1319 }
1320 }
1321
implements_interface(Klass * k) const1322 bool InstanceKlass::implements_interface(Klass* k) const {
1323 if (this == k) return true;
1324 assert(k->is_interface(), "should be an interface class");
1325 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1326 if (transitive_interfaces()->at(i) == k) {
1327 return true;
1328 }
1329 }
1330 return false;
1331 }
1332
is_same_or_direct_interface(Klass * k) const1333 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1334 // Verify direct super interface
1335 if (this == k) return true;
1336 assert(k->is_interface(), "should be an interface class");
1337 for (int i = 0; i < local_interfaces()->length(); i++) {
1338 if (local_interfaces()->at(i) == k) {
1339 return true;
1340 }
1341 }
1342 return false;
1343 }
1344
allocate_objArray(int n,int length,TRAPS)1345 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1346 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1347 int size = objArrayOopDesc::object_size(length);
1348 Klass* ak = array_klass(n, CHECK_NULL);
1349 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1350 /* do_zero */ true, CHECK_NULL);
1351 return o;
1352 }
1353
register_finalizer(instanceOop i,TRAPS)1354 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1355 if (TraceFinalizerRegistration) {
1356 tty->print("Registered ");
1357 i->print_value_on(tty);
1358 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1359 }
1360 instanceHandle h_i(THREAD, i);
1361 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1362 JavaValue result(T_VOID);
1363 JavaCallArguments args(h_i);
1364 methodHandle mh (THREAD, Universe::finalizer_register_method());
1365 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1366 return h_i();
1367 }
1368
allocate_instance(TRAPS)1369 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1370 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1371 int size = size_helper(); // Query before forming handle.
1372
1373 instanceOop i;
1374
1375 i = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1376 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1377 i = register_finalizer(i, CHECK_NULL);
1378 }
1379 return i;
1380 }
1381
allocate_instance_handle(TRAPS)1382 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1383 return instanceHandle(THREAD, allocate_instance(THREAD));
1384 }
1385
check_valid_for_instantiation(bool throwError,TRAPS)1386 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1387 if (is_interface() || is_abstract()) {
1388 ResourceMark rm(THREAD);
1389 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1390 : vmSymbols::java_lang_InstantiationException(), external_name());
1391 }
1392 if (this == vmClasses::Class_klass()) {
1393 ResourceMark rm(THREAD);
1394 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1395 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1396 }
1397 }
1398
array_klass(int n,TRAPS)1399 Klass* InstanceKlass::array_klass(int n, TRAPS) {
1400 // Need load-acquire for lock-free read
1401 if (array_klasses_acquire() == NULL) {
1402 ResourceMark rm(THREAD);
1403 JavaThread *jt = THREAD;
1404 {
1405 // Atomic creation of array_klasses
1406 MutexLocker ma(THREAD, MultiArray_lock);
1407
1408 // Check if update has already taken place
1409 if (array_klasses() == NULL) {
1410 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1411 // use 'release' to pair with lock-free load
1412 release_set_array_klasses(k);
1413 }
1414 }
1415 }
1416 // array_klasses() will always be set at this point
1417 ObjArrayKlass* oak = array_klasses();
1418 return oak->array_klass(n, THREAD);
1419 }
1420
array_klass_or_null(int n)1421 Klass* InstanceKlass::array_klass_or_null(int n) {
1422 // Need load-acquire for lock-free read
1423 ObjArrayKlass* oak = array_klasses_acquire();
1424 if (oak == NULL) {
1425 return NULL;
1426 } else {
1427 return oak->array_klass_or_null(n);
1428 }
1429 }
1430
array_klass(TRAPS)1431 Klass* InstanceKlass::array_klass(TRAPS) {
1432 return array_klass(1, THREAD);
1433 }
1434
array_klass_or_null()1435 Klass* InstanceKlass::array_klass_or_null() {
1436 return array_klass_or_null(1);
1437 }
1438
1439 static int call_class_initializer_counter = 0; // for debugging
1440
class_initializer() const1441 Method* InstanceKlass::class_initializer() const {
1442 Method* clinit = find_method(
1443 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1444 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1445 return clinit;
1446 }
1447 return NULL;
1448 }
1449
call_class_initializer(TRAPS)1450 void InstanceKlass::call_class_initializer(TRAPS) {
1451 if (ReplayCompiles &&
1452 (ReplaySuppressInitializers == 1 ||
1453 (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1454 // Hide the existence of the initializer for the purpose of replaying the compile
1455 return;
1456 }
1457
1458 methodHandle h_method(THREAD, class_initializer());
1459 assert(!is_initialized(), "we cannot initialize twice");
1460 LogTarget(Info, class, init) lt;
1461 if (lt.is_enabled()) {
1462 ResourceMark rm(THREAD);
1463 LogStream ls(lt);
1464 ls.print("%d Initializing ", call_class_initializer_counter++);
1465 name()->print_value_on(&ls);
1466 ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1467 }
1468 if (h_method() != NULL) {
1469 JavaCallArguments args; // No arguments
1470 JavaValue result(T_VOID);
1471 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1472 }
1473 }
1474
1475
mask_for(const methodHandle & method,int bci,InterpreterOopMap * entry_for)1476 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1477 InterpreterOopMap* entry_for) {
1478 // Lazily create the _oop_map_cache at first request
1479 // Lock-free access requires load_acquire.
1480 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1481 if (oop_map_cache == NULL) {
1482 MutexLocker x(OopMapCacheAlloc_lock);
1483 // Check if _oop_map_cache was allocated while we were waiting for this lock
1484 if ((oop_map_cache = _oop_map_cache) == NULL) {
1485 oop_map_cache = new OopMapCache();
1486 // Ensure _oop_map_cache is stable, since it is examined without a lock
1487 Atomic::release_store(&_oop_map_cache, oop_map_cache);
1488 }
1489 }
1490 // _oop_map_cache is constant after init; lookup below does its own locking.
1491 oop_map_cache->lookup(method, bci, entry_for);
1492 }
1493
contains_field_offset(int offset)1494 bool InstanceKlass::contains_field_offset(int offset) {
1495 fieldDescriptor fd;
1496 return find_field_from_offset(offset, false, &fd);
1497 }
1498
find_local_field(Symbol * name,Symbol * sig,fieldDescriptor * fd) const1499 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1500 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1501 Symbol* f_name = fs.name();
1502 Symbol* f_sig = fs.signature();
1503 if (f_name == name && f_sig == sig) {
1504 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1505 return true;
1506 }
1507 }
1508 return false;
1509 }
1510
1511
find_interface_field(Symbol * name,Symbol * sig,fieldDescriptor * fd) const1512 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1513 const int n = local_interfaces()->length();
1514 for (int i = 0; i < n; i++) {
1515 Klass* intf1 = local_interfaces()->at(i);
1516 assert(intf1->is_interface(), "just checking type");
1517 // search for field in current interface
1518 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1519 assert(fd->is_static(), "interface field must be static");
1520 return intf1;
1521 }
1522 // search for field in direct superinterfaces
1523 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1524 if (intf2 != NULL) return intf2;
1525 }
1526 // otherwise field lookup fails
1527 return NULL;
1528 }
1529
1530
find_field(Symbol * name,Symbol * sig,fieldDescriptor * fd) const1531 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1532 // search order according to newest JVM spec (5.4.3.2, p.167).
1533 // 1) search for field in current klass
1534 if (find_local_field(name, sig, fd)) {
1535 return const_cast<InstanceKlass*>(this);
1536 }
1537 // 2) search for field recursively in direct superinterfaces
1538 { Klass* intf = find_interface_field(name, sig, fd);
1539 if (intf != NULL) return intf;
1540 }
1541 // 3) apply field lookup recursively if superclass exists
1542 { Klass* supr = super();
1543 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1544 }
1545 // 4) otherwise field lookup fails
1546 return NULL;
1547 }
1548
1549
find_field(Symbol * name,Symbol * sig,bool is_static,fieldDescriptor * fd) const1550 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1551 // search order according to newest JVM spec (5.4.3.2, p.167).
1552 // 1) search for field in current klass
1553 if (find_local_field(name, sig, fd)) {
1554 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1555 }
1556 // 2) search for field recursively in direct superinterfaces
1557 if (is_static) {
1558 Klass* intf = find_interface_field(name, sig, fd);
1559 if (intf != NULL) return intf;
1560 }
1561 // 3) apply field lookup recursively if superclass exists
1562 { Klass* supr = super();
1563 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1564 }
1565 // 4) otherwise field lookup fails
1566 return NULL;
1567 }
1568
1569
find_local_field_from_offset(int offset,bool is_static,fieldDescriptor * fd) const1570 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1571 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1572 if (fs.offset() == offset) {
1573 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1574 if (fd->is_static() == is_static) return true;
1575 }
1576 }
1577 return false;
1578 }
1579
1580
find_field_from_offset(int offset,bool is_static,fieldDescriptor * fd) const1581 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1582 Klass* klass = const_cast<InstanceKlass*>(this);
1583 while (klass != NULL) {
1584 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1585 return true;
1586 }
1587 klass = klass->super();
1588 }
1589 return false;
1590 }
1591
1592
methods_do(void f (Method * method))1593 void InstanceKlass::methods_do(void f(Method* method)) {
1594 // Methods aren't stable until they are loaded. This can be read outside
1595 // a lock through the ClassLoaderData for profiling
1596 if (!is_loaded()) {
1597 return;
1598 }
1599
1600 int len = methods()->length();
1601 for (int index = 0; index < len; index++) {
1602 Method* m = methods()->at(index);
1603 assert(m->is_method(), "must be method");
1604 f(m);
1605 }
1606 }
1607
1608
do_local_static_fields(FieldClosure * cl)1609 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1610 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1611 if (fs.access_flags().is_static()) {
1612 fieldDescriptor& fd = fs.field_descriptor();
1613 cl->do_field(&fd);
1614 }
1615 }
1616 }
1617
1618
do_local_static_fields(void f (fieldDescriptor *,Handle,TRAPS),Handle mirror,TRAPS)1619 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1620 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1621 if (fs.access_flags().is_static()) {
1622 fieldDescriptor& fd = fs.field_descriptor();
1623 f(&fd, mirror, CHECK);
1624 }
1625 }
1626 }
1627
1628
compare_fields_by_offset(int * a,int * b)1629 static int compare_fields_by_offset(int* a, int* b) {
1630 return a[0] - b[0];
1631 }
1632
do_nonstatic_fields(FieldClosure * cl)1633 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1634 InstanceKlass* super = superklass();
1635 if (super != NULL) {
1636 super->do_nonstatic_fields(cl);
1637 }
1638 fieldDescriptor fd;
1639 int length = java_fields_count();
1640 // In DebugInfo nonstatic fields are sorted by offset.
1641 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1642 int j = 0;
1643 for (int i = 0; i < length; i += 1) {
1644 fd.reinitialize(this, i);
1645 if (!fd.is_static()) {
1646 fields_sorted[j + 0] = fd.offset();
1647 fields_sorted[j + 1] = i;
1648 j += 2;
1649 }
1650 }
1651 if (j > 0) {
1652 length = j;
1653 // _sort_Fn is defined in growableArray.hpp.
1654 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1655 for (int i = 0; i < length; i += 2) {
1656 fd.reinitialize(this, fields_sorted[i + 1]);
1657 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1658 cl->do_field(&fd);
1659 }
1660 }
1661 FREE_C_HEAP_ARRAY(int, fields_sorted);
1662 }
1663
1664
array_klasses_do(void f (Klass * k,TRAPS),TRAPS)1665 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1666 if (array_klasses() != NULL)
1667 array_klasses()->array_klasses_do(f, THREAD);
1668 }
1669
array_klasses_do(void f (Klass * k))1670 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1671 if (array_klasses() != NULL)
1672 array_klasses()->array_klasses_do(f);
1673 }
1674
1675 #ifdef ASSERT
linear_search(const Array<Method * > * methods,const Symbol * name,const Symbol * signature)1676 static int linear_search(const Array<Method*>* methods,
1677 const Symbol* name,
1678 const Symbol* signature) {
1679 const int len = methods->length();
1680 for (int index = 0; index < len; index++) {
1681 const Method* const m = methods->at(index);
1682 assert(m->is_method(), "must be method");
1683 if (m->signature() == signature && m->name() == name) {
1684 return index;
1685 }
1686 }
1687 return -1;
1688 }
1689 #endif
1690
1691 bool InstanceKlass::_disable_method_binary_search = false;
1692
linear_search(const Array<Method * > * methods,const Symbol * name)1693 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1694 int len = methods->length();
1695 int l = 0;
1696 int h = len - 1;
1697 while (l <= h) {
1698 Method* m = methods->at(l);
1699 if (m->name() == name) {
1700 return l;
1701 }
1702 l++;
1703 }
1704 return -1;
1705 }
1706
quick_search(const Array<Method * > * methods,const Symbol * name)1707 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1708 if (_disable_method_binary_search) {
1709 assert(DynamicDumpSharedSpaces, "must be");
1710 // At the final stage of dynamic dumping, the methods array may not be sorted
1711 // by ascending addresses of their names, so we can't use binary search anymore.
1712 // However, methods with the same name are still laid out consecutively inside the
1713 // methods array, so let's look for the first one that matches.
1714 return linear_search(methods, name);
1715 }
1716
1717 int len = methods->length();
1718 int l = 0;
1719 int h = len - 1;
1720
1721 // methods are sorted by ascending addresses of their names, so do binary search
1722 while (l <= h) {
1723 int mid = (l + h) >> 1;
1724 Method* m = methods->at(mid);
1725 assert(m->is_method(), "must be method");
1726 int res = m->name()->fast_compare(name);
1727 if (res == 0) {
1728 return mid;
1729 } else if (res < 0) {
1730 l = mid + 1;
1731 } else {
1732 h = mid - 1;
1733 }
1734 }
1735 return -1;
1736 }
1737
1738 // find_method looks up the name/signature in the local methods array
find_method(const Symbol * name,const Symbol * signature) const1739 Method* InstanceKlass::find_method(const Symbol* name,
1740 const Symbol* signature) const {
1741 return find_method_impl(name, signature,
1742 OverpassLookupMode::find,
1743 StaticLookupMode::find,
1744 PrivateLookupMode::find);
1745 }
1746
find_method_impl(const Symbol * name,const Symbol * signature,OverpassLookupMode overpass_mode,StaticLookupMode static_mode,PrivateLookupMode private_mode) const1747 Method* InstanceKlass::find_method_impl(const Symbol* name,
1748 const Symbol* signature,
1749 OverpassLookupMode overpass_mode,
1750 StaticLookupMode static_mode,
1751 PrivateLookupMode private_mode) const {
1752 return InstanceKlass::find_method_impl(methods(),
1753 name,
1754 signature,
1755 overpass_mode,
1756 static_mode,
1757 private_mode);
1758 }
1759
1760 // find_instance_method looks up the name/signature in the local methods array
1761 // and skips over static methods
find_instance_method(const Array<Method * > * methods,const Symbol * name,const Symbol * signature,PrivateLookupMode private_mode)1762 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1763 const Symbol* name,
1764 const Symbol* signature,
1765 PrivateLookupMode private_mode) {
1766 Method* const meth = InstanceKlass::find_method_impl(methods,
1767 name,
1768 signature,
1769 OverpassLookupMode::find,
1770 StaticLookupMode::skip,
1771 private_mode);
1772 assert(((meth == NULL) || !meth->is_static()),
1773 "find_instance_method should have skipped statics");
1774 return meth;
1775 }
1776
1777 // find_instance_method looks up the name/signature in the local methods array
1778 // and skips over static methods
find_instance_method(const Symbol * name,const Symbol * signature,PrivateLookupMode private_mode) const1779 Method* InstanceKlass::find_instance_method(const Symbol* name,
1780 const Symbol* signature,
1781 PrivateLookupMode private_mode) const {
1782 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1783 }
1784
1785 // Find looks up the name/signature in the local methods array
1786 // and filters on the overpass, static and private flags
1787 // This returns the first one found
1788 // note that the local methods array can have up to one overpass, one static
1789 // and one instance (private or not) with the same name/signature
find_local_method(const Symbol * name,const Symbol * signature,OverpassLookupMode overpass_mode,StaticLookupMode static_mode,PrivateLookupMode private_mode) const1790 Method* InstanceKlass::find_local_method(const Symbol* name,
1791 const Symbol* signature,
1792 OverpassLookupMode overpass_mode,
1793 StaticLookupMode static_mode,
1794 PrivateLookupMode private_mode) const {
1795 return InstanceKlass::find_method_impl(methods(),
1796 name,
1797 signature,
1798 overpass_mode,
1799 static_mode,
1800 private_mode);
1801 }
1802
1803 // Find looks up the name/signature in the local methods array
1804 // and filters on the overpass, static and private flags
1805 // This returns the first one found
1806 // note that the local methods array can have up to one overpass, one static
1807 // and one instance (private or not) with the same name/signature
find_local_method(const Array<Method * > * methods,const Symbol * name,const Symbol * signature,OverpassLookupMode overpass_mode,StaticLookupMode static_mode,PrivateLookupMode private_mode)1808 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1809 const Symbol* name,
1810 const Symbol* signature,
1811 OverpassLookupMode overpass_mode,
1812 StaticLookupMode static_mode,
1813 PrivateLookupMode private_mode) {
1814 return InstanceKlass::find_method_impl(methods,
1815 name,
1816 signature,
1817 overpass_mode,
1818 static_mode,
1819 private_mode);
1820 }
1821
find_method(const Array<Method * > * methods,const Symbol * name,const Symbol * signature)1822 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1823 const Symbol* name,
1824 const Symbol* signature) {
1825 return InstanceKlass::find_method_impl(methods,
1826 name,
1827 signature,
1828 OverpassLookupMode::find,
1829 StaticLookupMode::find,
1830 PrivateLookupMode::find);
1831 }
1832
find_method_impl(const Array<Method * > * methods,const Symbol * name,const Symbol * signature,OverpassLookupMode overpass_mode,StaticLookupMode static_mode,PrivateLookupMode private_mode)1833 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1834 const Symbol* name,
1835 const Symbol* signature,
1836 OverpassLookupMode overpass_mode,
1837 StaticLookupMode static_mode,
1838 PrivateLookupMode private_mode) {
1839 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1840 return hit >= 0 ? methods->at(hit): NULL;
1841 }
1842
1843 // true if method matches signature and conforms to skipping_X conditions.
method_matches(const Method * m,const Symbol * signature,bool skipping_overpass,bool skipping_static,bool skipping_private)1844 static bool method_matches(const Method* m,
1845 const Symbol* signature,
1846 bool skipping_overpass,
1847 bool skipping_static,
1848 bool skipping_private) {
1849 return ((m->signature() == signature) &&
1850 (!skipping_overpass || !m->is_overpass()) &&
1851 (!skipping_static || !m->is_static()) &&
1852 (!skipping_private || !m->is_private()));
1853 }
1854
1855 // Used directly for default_methods to find the index into the
1856 // default_vtable_indices, and indirectly by find_method
1857 // find_method_index looks in the local methods array to return the index
1858 // of the matching name/signature. If, overpass methods are being ignored,
1859 // the search continues to find a potential non-overpass match. This capability
1860 // is important during method resolution to prefer a static method, for example,
1861 // over an overpass method.
1862 // There is the possibility in any _method's array to have the same name/signature
1863 // for a static method, an overpass method and a local instance method
1864 // To correctly catch a given method, the search criteria may need
1865 // to explicitly skip the other two. For local instance methods, it
1866 // is often necessary to skip private methods
find_method_index(const Array<Method * > * methods,const Symbol * name,const Symbol * signature,OverpassLookupMode overpass_mode,StaticLookupMode static_mode,PrivateLookupMode private_mode)1867 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1868 const Symbol* name,
1869 const Symbol* signature,
1870 OverpassLookupMode overpass_mode,
1871 StaticLookupMode static_mode,
1872 PrivateLookupMode private_mode) {
1873 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
1874 const bool skipping_static = (static_mode == StaticLookupMode::skip);
1875 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
1876 const int hit = quick_search(methods, name);
1877 if (hit != -1) {
1878 const Method* const m = methods->at(hit);
1879
1880 // Do linear search to find matching signature. First, quick check
1881 // for common case, ignoring overpasses if requested.
1882 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1883 return hit;
1884 }
1885
1886 // search downwards through overloaded methods
1887 int i;
1888 for (i = hit - 1; i >= 0; --i) {
1889 const Method* const m = methods->at(i);
1890 assert(m->is_method(), "must be method");
1891 if (m->name() != name) {
1892 break;
1893 }
1894 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1895 return i;
1896 }
1897 }
1898 // search upwards
1899 for (i = hit + 1; i < methods->length(); ++i) {
1900 const Method* const m = methods->at(i);
1901 assert(m->is_method(), "must be method");
1902 if (m->name() != name) {
1903 break;
1904 }
1905 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1906 return i;
1907 }
1908 }
1909 // not found
1910 #ifdef ASSERT
1911 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1912 linear_search(methods, name, signature);
1913 assert(-1 == index, "binary search should have found entry %d", index);
1914 #endif
1915 }
1916 return -1;
1917 }
1918
find_method_by_name(const Symbol * name,int * end) const1919 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1920 return find_method_by_name(methods(), name, end);
1921 }
1922
find_method_by_name(const Array<Method * > * methods,const Symbol * name,int * end_ptr)1923 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1924 const Symbol* name,
1925 int* end_ptr) {
1926 assert(end_ptr != NULL, "just checking");
1927 int start = quick_search(methods, name);
1928 int end = start + 1;
1929 if (start != -1) {
1930 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1931 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1932 *end_ptr = end;
1933 return start;
1934 }
1935 return -1;
1936 }
1937
1938 // uncached_lookup_method searches both the local class methods array and all
1939 // superclasses methods arrays, skipping any overpass methods in superclasses,
1940 // and possibly skipping private methods.
uncached_lookup_method(const Symbol * name,const Symbol * signature,OverpassLookupMode overpass_mode,PrivateLookupMode private_mode) const1941 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1942 const Symbol* signature,
1943 OverpassLookupMode overpass_mode,
1944 PrivateLookupMode private_mode) const {
1945 OverpassLookupMode overpass_local_mode = overpass_mode;
1946 const Klass* klass = this;
1947 while (klass != NULL) {
1948 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1949 signature,
1950 overpass_local_mode,
1951 StaticLookupMode::find,
1952 private_mode);
1953 if (method != NULL) {
1954 return method;
1955 }
1956 klass = klass->super();
1957 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
1958 }
1959 return NULL;
1960 }
1961
1962 #ifdef ASSERT
1963 // search through class hierarchy and return true if this class or
1964 // one of the superclasses was redefined
has_redefined_this_or_super() const1965 bool InstanceKlass::has_redefined_this_or_super() const {
1966 const Klass* klass = this;
1967 while (klass != NULL) {
1968 if (InstanceKlass::cast(klass)->has_been_redefined()) {
1969 return true;
1970 }
1971 klass = klass->super();
1972 }
1973 return false;
1974 }
1975 #endif
1976
1977 // lookup a method in the default methods list then in all transitive interfaces
1978 // Do NOT return private or static methods
lookup_method_in_ordered_interfaces(Symbol * name,Symbol * signature) const1979 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1980 Symbol* signature) const {
1981 Method* m = NULL;
1982 if (default_methods() != NULL) {
1983 m = find_method(default_methods(), name, signature);
1984 }
1985 // Look up interfaces
1986 if (m == NULL) {
1987 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
1988 }
1989 return m;
1990 }
1991
1992 // lookup a method in all the interfaces that this class implements
1993 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1994 // They should only be found in the initial InterfaceMethodRef
lookup_method_in_all_interfaces(Symbol * name,Symbol * signature,DefaultsLookupMode defaults_mode) const1995 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1996 Symbol* signature,
1997 DefaultsLookupMode defaults_mode) const {
1998 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1999 int num_ifs = all_ifs->length();
2000 InstanceKlass *ik = NULL;
2001 for (int i = 0; i < num_ifs; i++) {
2002 ik = all_ifs->at(i);
2003 Method* m = ik->lookup_method(name, signature);
2004 if (m != NULL && m->is_public() && !m->is_static() &&
2005 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2006 return m;
2007 }
2008 }
2009 return NULL;
2010 }
2011
2012 /* jni_id_for_impl for jfieldIds only */
jni_id_for_impl(int offset)2013 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
2014 MutexLocker ml(JfieldIdCreation_lock);
2015 // Retry lookup after we got the lock
2016 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
2017 if (probe == NULL) {
2018 // Slow case, allocate new static field identifier
2019 probe = new JNIid(this, offset, jni_ids());
2020 set_jni_ids(probe);
2021 }
2022 return probe;
2023 }
2024
2025
2026 /* jni_id_for for jfieldIds only */
jni_id_for(int offset)2027 JNIid* InstanceKlass::jni_id_for(int offset) {
2028 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
2029 if (probe == NULL) {
2030 probe = jni_id_for_impl(offset);
2031 }
2032 return probe;
2033 }
2034
enclosing_method_data(int offset) const2035 u2 InstanceKlass::enclosing_method_data(int offset) const {
2036 const Array<jushort>* const inner_class_list = inner_classes();
2037 if (inner_class_list == NULL) {
2038 return 0;
2039 }
2040 const int length = inner_class_list->length();
2041 if (length % inner_class_next_offset == 0) {
2042 return 0;
2043 }
2044 const int index = length - enclosing_method_attribute_size;
2045 assert(offset < enclosing_method_attribute_size, "invalid offset");
2046 return inner_class_list->at(index + offset);
2047 }
2048
set_enclosing_method_indices(u2 class_index,u2 method_index)2049 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2050 u2 method_index) {
2051 Array<jushort>* inner_class_list = inner_classes();
2052 assert (inner_class_list != NULL, "_inner_classes list is not set up");
2053 int length = inner_class_list->length();
2054 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2055 int index = length - enclosing_method_attribute_size;
2056 inner_class_list->at_put(
2057 index + enclosing_method_class_index_offset, class_index);
2058 inner_class_list->at_put(
2059 index + enclosing_method_method_index_offset, method_index);
2060 }
2061 }
2062
2063 // Lookup or create a jmethodID.
2064 // This code is called by the VMThread and JavaThreads so the
2065 // locking has to be done very carefully to avoid deadlocks
2066 // and/or other cache consistency problems.
2067 //
get_jmethod_id(const methodHandle & method_h)2068 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2069 size_t idnum = (size_t)method_h->method_idnum();
2070 jmethodID* jmeths = methods_jmethod_ids_acquire();
2071 size_t length = 0;
2072 jmethodID id = NULL;
2073
2074 // We use a double-check locking idiom here because this cache is
2075 // performance sensitive. In the normal system, this cache only
2076 // transitions from NULL to non-NULL which is safe because we use
2077 // release_set_methods_jmethod_ids() to advertise the new cache.
2078 // A partially constructed cache should never be seen by a racing
2079 // thread. We also use release_store() to save a new jmethodID
2080 // in the cache so a partially constructed jmethodID should never be
2081 // seen either. Cache reads of existing jmethodIDs proceed without a
2082 // lock, but cache writes of a new jmethodID requires uniqueness and
2083 // creation of the cache itself requires no leaks so a lock is
2084 // generally acquired in those two cases.
2085 //
2086 // If the RedefineClasses() API has been used, then this cache can
2087 // grow and we'll have transitions from non-NULL to bigger non-NULL.
2088 // Cache creation requires no leaks and we require safety between all
2089 // cache accesses and freeing of the old cache so a lock is generally
2090 // acquired when the RedefineClasses() API has been used.
2091
2092 if (jmeths != NULL) {
2093 // the cache already exists
2094 if (!idnum_can_increment()) {
2095 // the cache can't grow so we can just get the current values
2096 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2097 } else {
2098 // cache can grow so we have to be more careful
2099 if (Threads::number_of_threads() == 0 ||
2100 SafepointSynchronize::is_at_safepoint()) {
2101 // we're single threaded or at a safepoint - no locking needed
2102 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2103 } else {
2104 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2105 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2106 }
2107 }
2108 }
2109 // implied else:
2110 // we need to allocate a cache so default length and id values are good
2111
2112 if (jmeths == NULL || // no cache yet
2113 length <= idnum || // cache is too short
2114 id == NULL) { // cache doesn't contain entry
2115
2116 // This function can be called by the VMThread so we have to do all
2117 // things that might block on a safepoint before grabbing the lock.
2118 // Otherwise, we can deadlock with the VMThread or have a cache
2119 // consistency issue. These vars keep track of what we might have
2120 // to free after the lock is dropped.
2121 jmethodID to_dealloc_id = NULL;
2122 jmethodID* to_dealloc_jmeths = NULL;
2123
2124 // may not allocate new_jmeths or use it if we allocate it
2125 jmethodID* new_jmeths = NULL;
2126 if (length <= idnum) {
2127 // allocate a new cache that might be used
2128 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
2129 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
2130 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
2131 // cache size is stored in element[0], other elements offset by one
2132 new_jmeths[0] = (jmethodID)size;
2133 }
2134
2135 // allocate a new jmethodID that might be used
2136 jmethodID new_id = NULL;
2137 if (method_h->is_old() && !method_h->is_obsolete()) {
2138 // The method passed in is old (but not obsolete), we need to use the current version
2139 Method* current_method = method_with_idnum((int)idnum);
2140 assert(current_method != NULL, "old and but not obsolete, so should exist");
2141 new_id = Method::make_jmethod_id(class_loader_data(), current_method);
2142 } else {
2143 // It is the current version of the method or an obsolete method,
2144 // use the version passed in
2145 new_id = Method::make_jmethod_id(class_loader_data(), method_h());
2146 }
2147
2148 if (Threads::number_of_threads() == 0 ||
2149 SafepointSynchronize::is_at_safepoint()) {
2150 // we're single threaded or at a safepoint - no locking needed
2151 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2152 &to_dealloc_id, &to_dealloc_jmeths);
2153 } else {
2154 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2155 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2156 &to_dealloc_id, &to_dealloc_jmeths);
2157 }
2158
2159 // The lock has been dropped so we can free resources.
2160 // Free up either the old cache or the new cache if we allocated one.
2161 if (to_dealloc_jmeths != NULL) {
2162 FreeHeap(to_dealloc_jmeths);
2163 }
2164 // free up the new ID since it wasn't needed
2165 if (to_dealloc_id != NULL) {
2166 Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
2167 }
2168 }
2169 return id;
2170 }
2171
2172 // Figure out how many jmethodIDs haven't been allocated, and make
2173 // sure space for them is pre-allocated. This makes getting all
2174 // method ids much, much faster with classes with more than 8
2175 // methods, and has a *substantial* effect on performance with jvmti
2176 // code that loads all jmethodIDs for all classes.
ensure_space_for_methodids(int start_offset)2177 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2178 int new_jmeths = 0;
2179 int length = methods()->length();
2180 for (int index = start_offset; index < length; index++) {
2181 Method* m = methods()->at(index);
2182 jmethodID id = m->find_jmethod_id_or_null();
2183 if (id == NULL) {
2184 new_jmeths++;
2185 }
2186 }
2187 if (new_jmeths != 0) {
2188 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2189 }
2190 }
2191
2192 // Common code to fetch the jmethodID from the cache or update the
2193 // cache with the new jmethodID. This function should never do anything
2194 // that causes the caller to go to a safepoint or we can deadlock with
2195 // the VMThread or have cache consistency issues.
2196 //
get_jmethod_id_fetch_or_update(size_t idnum,jmethodID new_id,jmethodID * new_jmeths,jmethodID * to_dealloc_id_p,jmethodID ** to_dealloc_jmeths_p)2197 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
2198 size_t idnum, jmethodID new_id,
2199 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
2200 jmethodID** to_dealloc_jmeths_p) {
2201 assert(new_id != NULL, "sanity check");
2202 assert(to_dealloc_id_p != NULL, "sanity check");
2203 assert(to_dealloc_jmeths_p != NULL, "sanity check");
2204 assert(Threads::number_of_threads() == 0 ||
2205 SafepointSynchronize::is_at_safepoint() ||
2206 JmethodIdCreation_lock->owned_by_self(), "sanity check");
2207
2208 // reacquire the cache - we are locked, single threaded or at a safepoint
2209 jmethodID* jmeths = methods_jmethod_ids_acquire();
2210 jmethodID id = NULL;
2211 size_t length = 0;
2212
2213 if (jmeths == NULL || // no cache yet
2214 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
2215 if (jmeths != NULL) {
2216 // copy any existing entries from the old cache
2217 for (size_t index = 0; index < length; index++) {
2218 new_jmeths[index+1] = jmeths[index+1];
2219 }
2220 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
2221 }
2222 release_set_methods_jmethod_ids(jmeths = new_jmeths);
2223 } else {
2224 // fetch jmethodID (if any) from the existing cache
2225 id = jmeths[idnum+1];
2226 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
2227 }
2228 if (id == NULL) {
2229 // No matching jmethodID in the existing cache or we have a new
2230 // cache or we just grew the cache. This cache write is done here
2231 // by the first thread to win the foot race because a jmethodID
2232 // needs to be unique once it is generally available.
2233 id = new_id;
2234
2235 // The jmethodID cache can be read while unlocked so we have to
2236 // make sure the new jmethodID is complete before installing it
2237 // in the cache.
2238 Atomic::release_store(&jmeths[idnum+1], id);
2239 } else {
2240 *to_dealloc_id_p = new_id; // save new id for later delete
2241 }
2242 return id;
2243 }
2244
2245
2246 // Common code to get the jmethodID cache length and the jmethodID
2247 // value at index idnum if there is one.
2248 //
get_jmethod_id_length_value(jmethodID * cache,size_t idnum,size_t * length_p,jmethodID * id_p)2249 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
2250 size_t idnum, size_t *length_p, jmethodID* id_p) {
2251 assert(cache != NULL, "sanity check");
2252 assert(length_p != NULL, "sanity check");
2253 assert(id_p != NULL, "sanity check");
2254
2255 // cache size is stored in element[0], other elements offset by one
2256 *length_p = (size_t)cache[0];
2257 if (*length_p <= idnum) { // cache is too short
2258 *id_p = NULL;
2259 } else {
2260 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
2261 }
2262 }
2263
2264
2265 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
jmethod_id_or_null(Method * method)2266 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2267 size_t idnum = (size_t)method->method_idnum();
2268 jmethodID* jmeths = methods_jmethod_ids_acquire();
2269 size_t length; // length assigned as debugging crumb
2270 jmethodID id = NULL;
2271 if (jmeths != NULL && // If there is a cache
2272 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
2273 id = jmeths[idnum+1]; // Look up the id (may be NULL)
2274 }
2275 return id;
2276 }
2277
dependencies()2278 inline DependencyContext InstanceKlass::dependencies() {
2279 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2280 return dep_context;
2281 }
2282
mark_dependent_nmethods(KlassDepChange & changes)2283 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
2284 return dependencies().mark_dependent_nmethods(changes);
2285 }
2286
add_dependent_nmethod(nmethod * nm)2287 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2288 dependencies().add_dependent_nmethod(nm);
2289 }
2290
remove_dependent_nmethod(nmethod * nm)2291 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
2292 dependencies().remove_dependent_nmethod(nm);
2293 }
2294
clean_dependency_context()2295 void InstanceKlass::clean_dependency_context() {
2296 dependencies().clean_unloading_dependents();
2297 }
2298
2299 #ifndef PRODUCT
print_dependent_nmethods(bool verbose)2300 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2301 dependencies().print_dependent_nmethods(verbose);
2302 }
2303
is_dependent_nmethod(nmethod * nm)2304 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2305 return dependencies().is_dependent_nmethod(nm);
2306 }
2307 #endif //PRODUCT
2308
clean_weak_instanceklass_links()2309 void InstanceKlass::clean_weak_instanceklass_links() {
2310 clean_implementors_list();
2311 clean_method_data();
2312 }
2313
clean_implementors_list()2314 void InstanceKlass::clean_implementors_list() {
2315 assert(is_loader_alive(), "this klass should be live");
2316 if (is_interface()) {
2317 assert (ClassUnloading, "only called for ClassUnloading");
2318 for (;;) {
2319 // Use load_acquire due to competing with inserts
2320 InstanceKlass* impl = Atomic::load_acquire(adr_implementor());
2321 if (impl != NULL && !impl->is_loader_alive()) {
2322 // NULL this field, might be an unloaded instance klass or NULL
2323 InstanceKlass* volatile* iklass = adr_implementor();
2324 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)NULL) == impl) {
2325 // Successfully unlinking implementor.
2326 if (log_is_enabled(Trace, class, unload)) {
2327 ResourceMark rm;
2328 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2329 }
2330 return;
2331 }
2332 } else {
2333 return;
2334 }
2335 }
2336 }
2337 }
2338
clean_method_data()2339 void InstanceKlass::clean_method_data() {
2340 for (int m = 0; m < methods()->length(); m++) {
2341 MethodData* mdo = methods()->at(m)->method_data();
2342 if (mdo != NULL) {
2343 MutexLocker ml(SafepointSynchronize::is_at_safepoint() ? NULL : mdo->extra_data_lock());
2344 mdo->clean_method_data(/*always_clean*/false);
2345 }
2346 }
2347 }
2348
metaspace_pointers_do(MetaspaceClosure * it)2349 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2350 Klass::metaspace_pointers_do(it);
2351
2352 if (log_is_enabled(Trace, cds)) {
2353 ResourceMark rm;
2354 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2355 }
2356
2357 it->push(&_annotations);
2358 it->push((Klass**)&_array_klasses);
2359 if (!is_rewritten()) {
2360 it->push(&_constants, MetaspaceClosure::_writable);
2361 } else {
2362 it->push(&_constants);
2363 }
2364 it->push(&_inner_classes);
2365 #if INCLUDE_JVMTI
2366 it->push(&_previous_versions);
2367 #endif
2368 it->push(&_methods);
2369 it->push(&_default_methods);
2370 it->push(&_local_interfaces);
2371 it->push(&_transitive_interfaces);
2372 it->push(&_method_ordering);
2373 if (!is_rewritten()) {
2374 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2375 } else {
2376 it->push(&_default_vtable_indices);
2377 }
2378 it->push(&_fields);
2379
2380 if (itable_length() > 0) {
2381 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2382 int method_table_offset_in_words = ioe->offset()/wordSize;
2383 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2384 / itableOffsetEntry::size();
2385
2386 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2387 if (ioe->interface_klass() != NULL) {
2388 it->push(ioe->interface_klass_addr());
2389 itableMethodEntry* ime = ioe->first_method_entry(this);
2390 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2391 for (int index = 0; index < n; index ++) {
2392 it->push(ime[index].method_addr());
2393 }
2394 }
2395 }
2396 }
2397
2398 it->push(&_nest_members);
2399 it->push(&_permitted_subclasses);
2400 it->push(&_record_components);
2401 }
2402
remove_unshareable_info()2403 void InstanceKlass::remove_unshareable_info() {
2404
2405 if (can_be_verified_at_dumptime()) {
2406 // Remember this so we can avoid walking the hierarchy at runtime.
2407 set_verified_at_dump_time();
2408 }
2409
2410 Klass::remove_unshareable_info();
2411
2412 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2413 // Classes are attempted to link during dumping and may fail,
2414 // but these classes are still in the dictionary and class list in CLD.
2415 // If the class has failed verification, there is nothing else to remove.
2416 return;
2417 }
2418
2419 // Reset to the 'allocated' state to prevent any premature accessing to
2420 // a shared class at runtime while the class is still being loaded and
2421 // restored. A class' init_state is set to 'loaded' at runtime when it's
2422 // being added to class hierarchy (see SystemDictionary:::add_to_hierarchy()).
2423 _init_state = allocated;
2424
2425 { // Otherwise this needs to take out the Compile_lock.
2426 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2427 init_implementor();
2428 }
2429
2430 constants()->remove_unshareable_info();
2431
2432 for (int i = 0; i < methods()->length(); i++) {
2433 Method* m = methods()->at(i);
2434 m->remove_unshareable_info();
2435 }
2436
2437 // do array classes also.
2438 if (array_klasses() != NULL) {
2439 array_klasses()->remove_unshareable_info();
2440 }
2441
2442 // These are not allocated from metaspace. They are safe to set to NULL.
2443 _source_debug_extension = NULL;
2444 _dep_context = NULL;
2445 _osr_nmethods_head = NULL;
2446 #if INCLUDE_JVMTI
2447 _breakpoints = NULL;
2448 _previous_versions = NULL;
2449 _cached_class_file = NULL;
2450 _jvmti_cached_class_field_map = NULL;
2451 #endif
2452
2453 _init_thread = NULL;
2454 _methods_jmethod_ids = NULL;
2455 _jni_ids = NULL;
2456 _oop_map_cache = NULL;
2457 // clear _nest_host to ensure re-load at runtime
2458 _nest_host = NULL;
2459 init_shared_package_entry();
2460 _dep_context_last_cleaned = 0;
2461 }
2462
remove_java_mirror()2463 void InstanceKlass::remove_java_mirror() {
2464 Klass::remove_java_mirror();
2465
2466 // do array classes also.
2467 if (array_klasses() != NULL) {
2468 array_klasses()->remove_java_mirror();
2469 }
2470 }
2471
init_shared_package_entry()2472 void InstanceKlass::init_shared_package_entry() {
2473 #if !INCLUDE_CDS_JAVA_HEAP
2474 _package_entry = NULL;
2475 #else
2476 if (!MetaspaceShared::use_full_module_graph()) {
2477 _package_entry = NULL;
2478 } else if (DynamicDumpSharedSpaces) {
2479 if (!MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
2480 _package_entry = NULL;
2481 }
2482 } else {
2483 if (is_shared_unregistered_class()) {
2484 _package_entry = NULL;
2485 } else {
2486 _package_entry = PackageEntry::get_archived_entry(_package_entry);
2487 }
2488 }
2489 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2490 #endif
2491 }
2492
restore_unshareable_info(ClassLoaderData * loader_data,Handle protection_domain,PackageEntry * pkg_entry,TRAPS)2493 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2494 PackageEntry* pkg_entry, TRAPS) {
2495 // SystemDictionary::add_to_hierarchy() sets the init_state to loaded
2496 // before the InstanceKlass is added to the SystemDictionary. Make
2497 // sure the current state is <loaded.
2498 assert(!is_loaded(), "invalid init state");
2499 assert(!shared_loading_failed(), "Must not try to load failed class again");
2500 set_package(loader_data, pkg_entry, CHECK);
2501 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2502
2503 Array<Method*>* methods = this->methods();
2504 int num_methods = methods->length();
2505 for (int index = 0; index < num_methods; ++index) {
2506 methods->at(index)->restore_unshareable_info(CHECK);
2507 }
2508 #if INCLUDE_JVMTI
2509 if (JvmtiExport::has_redefined_a_class()) {
2510 // Reinitialize vtable because RedefineClasses may have changed some
2511 // entries in this vtable for super classes so the CDS vtable might
2512 // point to old or obsolete entries. RedefineClasses doesn't fix up
2513 // vtables in the shared system dictionary, only the main one.
2514 // It also redefines the itable too so fix that too.
2515 // First fix any default methods that point to a super class that may
2516 // have been redefined.
2517 bool trace_name_printed = false;
2518 adjust_default_methods(&trace_name_printed);
2519 vtable().initialize_vtable();
2520 itable().initialize_itable();
2521 }
2522 #endif
2523
2524 // restore constant pool resolved references
2525 constants()->restore_unshareable_info(CHECK);
2526
2527 if (array_klasses() != NULL) {
2528 // Array classes have null protection domain.
2529 // --> see ArrayKlass::complete_create_array_klass()
2530 array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2531 }
2532
2533 // Initialize current biased locking state.
2534 if (UseBiasedLocking && BiasedLocking::enabled()) {
2535 set_prototype_header(markWord::biased_locking_prototype());
2536 }
2537
2538 // Initialize @ValueBased class annotation
2539 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation()) {
2540 set_is_value_based();
2541 set_prototype_header(markWord::prototype());
2542 }
2543 }
2544
2545 // Check if a class or any of its supertypes has a version older than 50.
2546 // CDS will not perform verification of old classes during dump time because
2547 // without changing the old verifier, the verification constraint cannot be
2548 // retrieved during dump time.
2549 // Verification of archived old classes will be performed during run time.
can_be_verified_at_dumptime() const2550 bool InstanceKlass::can_be_verified_at_dumptime() const {
2551 if (major_version() < 50 /*JAVA_6_VERSION*/) {
2552 return false;
2553 }
2554 if (java_super() != NULL && !java_super()->can_be_verified_at_dumptime()) {
2555 return false;
2556 }
2557 Array<InstanceKlass*>* interfaces = local_interfaces();
2558 int len = interfaces->length();
2559 for (int i = 0; i < len; i++) {
2560 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2561 return false;
2562 }
2563 }
2564 return true;
2565 }
2566
set_shared_class_loader_type(s2 loader_type)2567 void InstanceKlass::set_shared_class_loader_type(s2 loader_type) {
2568 switch (loader_type) {
2569 case ClassLoader::BOOT_LOADER:
2570 _misc_flags |= _misc_is_shared_boot_class;
2571 break;
2572 case ClassLoader::PLATFORM_LOADER:
2573 _misc_flags |= _misc_is_shared_platform_class;
2574 break;
2575 case ClassLoader::APP_LOADER:
2576 _misc_flags |= _misc_is_shared_app_class;
2577 break;
2578 default:
2579 ShouldNotReachHere();
2580 break;
2581 }
2582 }
2583
assign_class_loader_type()2584 void InstanceKlass::assign_class_loader_type() {
2585 ClassLoaderData *cld = class_loader_data();
2586 if (cld->is_boot_class_loader_data()) {
2587 set_shared_class_loader_type(ClassLoader::BOOT_LOADER);
2588 }
2589 else if (cld->is_platform_class_loader_data()) {
2590 set_shared_class_loader_type(ClassLoader::PLATFORM_LOADER);
2591 }
2592 else if (cld->is_system_class_loader_data()) {
2593 set_shared_class_loader_type(ClassLoader::APP_LOADER);
2594 }
2595 }
2596
2597 #if INCLUDE_JVMTI
clear_all_breakpoints(Method * m)2598 static void clear_all_breakpoints(Method* m) {
2599 m->clear_all_breakpoints();
2600 }
2601 #endif
2602
unload_class(InstanceKlass * ik)2603 void InstanceKlass::unload_class(InstanceKlass* ik) {
2604 // Release dependencies.
2605 ik->dependencies().remove_all_dependents();
2606
2607 // notify the debugger
2608 if (JvmtiExport::should_post_class_unload()) {
2609 JvmtiExport::post_class_unload(ik);
2610 }
2611
2612 // notify ClassLoadingService of class unload
2613 ClassLoadingService::notify_class_unloaded(ik);
2614
2615 if (Arguments::is_dumping_archive()) {
2616 SystemDictionaryShared::remove_dumptime_info(ik);
2617 }
2618
2619 if (log_is_enabled(Info, class, unload)) {
2620 ResourceMark rm;
2621 log_info(class, unload)("unloading class %s " INTPTR_FORMAT, ik->external_name(), p2i(ik));
2622 }
2623
2624 Events::log_class_unloading(Thread::current(), ik);
2625
2626 #if INCLUDE_JFR
2627 assert(ik != NULL, "invariant");
2628 EventClassUnload event;
2629 event.set_unloadedClass(ik);
2630 event.set_definingClassLoader(ik->class_loader_data());
2631 event.commit();
2632 #endif
2633 }
2634
method_release_C_heap_structures(Method * m)2635 static void method_release_C_heap_structures(Method* m) {
2636 m->release_C_heap_structures();
2637 }
2638
release_C_heap_structures()2639 void InstanceKlass::release_C_heap_structures() {
2640
2641 // Clean up C heap
2642 release_C_heap_structures_internal();
2643 constants()->release_C_heap_structures();
2644
2645 // Deallocate and call destructors for MDO mutexes
2646 methods_do(method_release_C_heap_structures);
2647 }
2648
release_C_heap_structures_internal()2649 void InstanceKlass::release_C_heap_structures_internal() {
2650 Klass::release_C_heap_structures();
2651
2652 // Can't release the constant pool here because the constant pool can be
2653 // deallocated separately from the InstanceKlass for default methods and
2654 // redefine classes.
2655
2656 // Deallocate oop map cache
2657 if (_oop_map_cache != NULL) {
2658 delete _oop_map_cache;
2659 _oop_map_cache = NULL;
2660 }
2661
2662 // Deallocate JNI identifiers for jfieldIDs
2663 JNIid::deallocate(jni_ids());
2664 set_jni_ids(NULL);
2665
2666 jmethodID* jmeths = methods_jmethod_ids_acquire();
2667 if (jmeths != (jmethodID*)NULL) {
2668 release_set_methods_jmethod_ids(NULL);
2669 FreeHeap(jmeths);
2670 }
2671
2672 assert(_dep_context == NULL,
2673 "dependencies should already be cleaned");
2674
2675 #if INCLUDE_JVMTI
2676 // Deallocate breakpoint records
2677 if (breakpoints() != 0x0) {
2678 methods_do(clear_all_breakpoints);
2679 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2680 }
2681
2682 // deallocate the cached class file
2683 if (_cached_class_file != NULL) {
2684 os::free(_cached_class_file);
2685 _cached_class_file = NULL;
2686 }
2687 #endif
2688
2689 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2690 }
2691
set_source_debug_extension(const char * array,int length)2692 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2693 if (array == NULL) {
2694 _source_debug_extension = NULL;
2695 } else {
2696 // Adding one to the attribute length in order to store a null terminator
2697 // character could cause an overflow because the attribute length is
2698 // already coded with an u4 in the classfile, but in practice, it's
2699 // unlikely to happen.
2700 assert((length+1) > length, "Overflow checking");
2701 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2702 for (int i = 0; i < length; i++) {
2703 sde[i] = array[i];
2704 }
2705 sde[length] = '\0';
2706 _source_debug_extension = sde;
2707 }
2708 }
2709
signature_name() const2710 const char* InstanceKlass::signature_name() const {
2711 int hash_len = 0;
2712 char hash_buf[40];
2713
2714 // Get the internal name as a c string
2715 const char* src = (const char*) (name()->as_C_string());
2716 const int src_length = (int)strlen(src);
2717
2718 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2719
2720 // Add L as type indicator
2721 int dest_index = 0;
2722 dest[dest_index++] = JVM_SIGNATURE_CLASS;
2723
2724 // Add the actual class name
2725 for (int src_index = 0; src_index < src_length; ) {
2726 dest[dest_index++] = src[src_index++];
2727 }
2728
2729 if (is_hidden()) { // Replace the last '+' with a '.'.
2730 for (int index = (int)src_length; index > 0; index--) {
2731 if (dest[index] == '+') {
2732 dest[index] = JVM_SIGNATURE_DOT;
2733 break;
2734 }
2735 }
2736 }
2737
2738 // If we have a hash, append it
2739 for (int hash_index = 0; hash_index < hash_len; ) {
2740 dest[dest_index++] = hash_buf[hash_index++];
2741 }
2742
2743 // Add the semicolon and the NULL
2744 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
2745 dest[dest_index] = '\0';
2746 return dest;
2747 }
2748
module() const2749 ModuleEntry* InstanceKlass::module() const {
2750 if (is_hidden() &&
2751 in_unnamed_package() &&
2752 class_loader_data()->has_class_mirror_holder()) {
2753 // For a non-strong hidden class defined to an unnamed package,
2754 // its (class held) CLD will not have an unnamed module created for it.
2755 // Two choices to find the correct ModuleEntry:
2756 // 1. If hidden class is within a nest, use nest host's module
2757 // 2. Find the unnamed module off from the class loader
2758 // For now option #2 is used since a nest host is not set until
2759 // after the instance class is created in jvm_lookup_define_class().
2760 if (class_loader_data()->is_boot_class_loader_data()) {
2761 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
2762 } else {
2763 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
2764 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
2765 return java_lang_Module::module_entry(module);
2766 }
2767 }
2768
2769 // Class is in a named package
2770 if (!in_unnamed_package()) {
2771 return _package_entry->module();
2772 }
2773
2774 // Class is in an unnamed package, return its loader's unnamed module
2775 return class_loader_data()->unnamed_module();
2776 }
2777
set_package(ClassLoaderData * loader_data,PackageEntry * pkg_entry,TRAPS)2778 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
2779
2780 // ensure java/ packages only loaded by boot or platform builtin loaders
2781 // not needed for shared class since CDS does not archive prohibited classes.
2782 if (!is_shared()) {
2783 check_prohibited_package(name(), loader_data, CHECK);
2784 }
2785
2786 if (is_shared() && _package_entry != NULL) {
2787 if (MetaspaceShared::use_full_module_graph() && _package_entry == pkg_entry) {
2788 // we can use the saved package
2789 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
2790 return;
2791 } else {
2792 _package_entry = NULL;
2793 }
2794 }
2795
2796 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
2797 // it returns, so we need to decrement it when the current function exits.
2798 TempNewSymbol from_class_name =
2799 (pkg_entry != NULL) ? NULL : ClassLoader::package_from_class_name(name());
2800
2801 Symbol* pkg_name;
2802 if (pkg_entry != NULL) {
2803 pkg_name = pkg_entry->name();
2804 } else {
2805 pkg_name = from_class_name;
2806 }
2807
2808 if (pkg_name != NULL && loader_data != NULL) {
2809
2810 // Find in class loader's package entry table.
2811 _package_entry = pkg_entry != NULL ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
2812
2813 // If the package name is not found in the loader's package
2814 // entry table, it is an indication that the package has not
2815 // been defined. Consider it defined within the unnamed module.
2816 if (_package_entry == NULL) {
2817
2818 if (!ModuleEntryTable::javabase_defined()) {
2819 // Before java.base is defined during bootstrapping, define all packages in
2820 // the java.base module. If a non-java.base package is erroneously placed
2821 // in the java.base module it will be caught later when java.base
2822 // is defined by ModuleEntryTable::verify_javabase_packages check.
2823 assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2824 _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2825 } else {
2826 assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2827 _package_entry = loader_data->packages()->lookup(pkg_name,
2828 loader_data->unnamed_module());
2829 }
2830
2831 // A package should have been successfully created
2832 DEBUG_ONLY(ResourceMark rm(THREAD));
2833 assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2834 name()->as_C_string(), loader_data->loader_name_and_id());
2835 }
2836
2837 if (log_is_enabled(Debug, module)) {
2838 ResourceMark rm(THREAD);
2839 ModuleEntry* m = _package_entry->module();
2840 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2841 external_name(),
2842 pkg_name->as_C_string(),
2843 loader_data->loader_name_and_id(),
2844 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2845 }
2846 } else {
2847 ResourceMark rm(THREAD);
2848 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2849 external_name(),
2850 (loader_data != NULL) ? loader_data->loader_name_and_id() : "NULL",
2851 UNNAMED_MODULE);
2852 }
2853 }
2854
2855 // Function set_classpath_index ensures that for a non-null _package_entry
2856 // of the InstanceKlass, the entry is in the boot loader's package entry table.
2857 // It then sets the classpath_index in the package entry record.
2858 //
2859 // The classpath_index field is used to find the entry on the boot loader class
2860 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
2861 // in an unnamed module. It is also used to indicate (for all packages whose
2862 // classes are loaded by the boot loader) that at least one of the package's
2863 // classes has been loaded.
set_classpath_index(s2 path_index)2864 void InstanceKlass::set_classpath_index(s2 path_index) {
2865 if (_package_entry != NULL) {
2866 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
2867 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
2868 assert(path_index != -1, "Unexpected classpath_index");
2869 _package_entry->set_classpath_index(path_index);
2870 }
2871 }
2872
2873 // different versions of is_same_class_package
2874
is_same_class_package(const Klass * class2) const2875 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2876 oop classloader1 = this->class_loader();
2877 PackageEntry* classpkg1 = this->package();
2878 if (class2->is_objArray_klass()) {
2879 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2880 }
2881
2882 oop classloader2;
2883 PackageEntry* classpkg2;
2884 if (class2->is_instance_klass()) {
2885 classloader2 = class2->class_loader();
2886 classpkg2 = class2->package();
2887 } else {
2888 assert(class2->is_typeArray_klass(), "should be type array");
2889 classloader2 = NULL;
2890 classpkg2 = NULL;
2891 }
2892
2893 // Same package is determined by comparing class loader
2894 // and package entries. Both must be the same. This rule
2895 // applies even to classes that are defined in the unnamed
2896 // package, they still must have the same class loader.
2897 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2898 return true;
2899 }
2900
2901 return false;
2902 }
2903
2904 // return true if this class and other_class are in the same package. Classloader
2905 // and classname information is enough to determine a class's package
is_same_class_package(oop other_class_loader,const Symbol * other_class_name) const2906 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2907 const Symbol* other_class_name) const {
2908 if (class_loader() != other_class_loader) {
2909 return false;
2910 }
2911 if (name()->fast_compare(other_class_name) == 0) {
2912 return true;
2913 }
2914
2915 {
2916 ResourceMark rm;
2917
2918 bool bad_class_name = false;
2919 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
2920 if (bad_class_name) {
2921 return false;
2922 }
2923 // Check that package_from_class_name() returns NULL, not "", if there is no package.
2924 assert(other_pkg == NULL || other_pkg->utf8_length() > 0, "package name is empty string");
2925
2926 const Symbol* const this_package_name =
2927 this->package() != NULL ? this->package()->name() : NULL;
2928
2929 if (this_package_name == NULL || other_pkg == NULL) {
2930 // One of the two doesn't have a package. Only return true if the other
2931 // one also doesn't have a package.
2932 return this_package_name == other_pkg;
2933 }
2934
2935 // Check if package is identical
2936 return this_package_name->fast_compare(other_pkg) == 0;
2937 }
2938 }
2939
is_prohibited_package_slow(Symbol * class_name)2940 static bool is_prohibited_package_slow(Symbol* class_name) {
2941 // Caller has ResourceMark
2942 int length;
2943 jchar* unicode = class_name->as_unicode(length);
2944 return (length >= 5 &&
2945 unicode[0] == 'j' &&
2946 unicode[1] == 'a' &&
2947 unicode[2] == 'v' &&
2948 unicode[3] == 'a' &&
2949 unicode[4] == '/');
2950 }
2951
2952 // Only boot and platform class loaders can define classes in "java/" packages.
check_prohibited_package(Symbol * class_name,ClassLoaderData * loader_data,TRAPS)2953 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2954 ClassLoaderData* loader_data,
2955 TRAPS) {
2956 if (!loader_data->is_boot_class_loader_data() &&
2957 !loader_data->is_platform_class_loader_data() &&
2958 class_name != NULL && class_name->utf8_length() >= 5) {
2959 ResourceMark rm(THREAD);
2960 bool prohibited;
2961 const u1* base = class_name->base();
2962 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
2963 prohibited = is_prohibited_package_slow(class_name);
2964 } else {
2965 char* name = class_name->as_C_string();
2966 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
2967 }
2968 if (prohibited) {
2969 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
2970 assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2971 char* name = pkg_name->as_C_string();
2972 const char* class_loader_name = loader_data->loader_name_and_id();
2973 StringUtils::replace_no_expand(name, "/", ".");
2974 const char* msg_text1 = "Class loader (instance of): ";
2975 const char* msg_text2 = " tried to load prohibited package name: ";
2976 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2977 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2978 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2979 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2980 }
2981 }
2982 return;
2983 }
2984
find_inner_classes_attr(int * ooff,int * noff,TRAPS) const2985 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2986 constantPoolHandle i_cp(THREAD, constants());
2987 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2988 int ioff = iter.inner_class_info_index();
2989 if (ioff != 0) {
2990 // Check to see if the name matches the class we're looking for
2991 // before attempting to find the class.
2992 if (i_cp->klass_name_at_matches(this, ioff)) {
2993 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2994 if (this == inner_klass) {
2995 *ooff = iter.outer_class_info_index();
2996 *noff = iter.inner_name_index();
2997 return true;
2998 }
2999 }
3000 }
3001 }
3002 return false;
3003 }
3004
compute_enclosing_class(bool * inner_is_member,TRAPS) const3005 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3006 InstanceKlass* outer_klass = NULL;
3007 *inner_is_member = false;
3008 int ooff = 0, noff = 0;
3009 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3010 if (has_inner_classes_attr) {
3011 constantPoolHandle i_cp(THREAD, constants());
3012 if (ooff != 0) {
3013 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3014 if (!ok->is_instance_klass()) {
3015 // If the outer class is not an instance klass then it cannot have
3016 // declared any inner classes.
3017 ResourceMark rm(THREAD);
3018 Exceptions::fthrow(
3019 THREAD_AND_LOCATION,
3020 vmSymbols::java_lang_IncompatibleClassChangeError(),
3021 "%s and %s disagree on InnerClasses attribute",
3022 ok->external_name(),
3023 external_name());
3024 return NULL;
3025 }
3026 outer_klass = InstanceKlass::cast(ok);
3027 *inner_is_member = true;
3028 }
3029 if (NULL == outer_klass) {
3030 // It may be a local class; try for that.
3031 int encl_method_class_idx = enclosing_method_class_index();
3032 if (encl_method_class_idx != 0) {
3033 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3034 outer_klass = InstanceKlass::cast(ok);
3035 *inner_is_member = false;
3036 }
3037 }
3038 }
3039
3040 // If no inner class attribute found for this class.
3041 if (NULL == outer_klass) return NULL;
3042
3043 // Throws an exception if outer klass has not declared k as an inner klass
3044 // We need evidence that each klass knows about the other, or else
3045 // the system could allow a spoof of an inner class to gain access rights.
3046 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3047 return outer_klass;
3048 }
3049
compute_modifier_flags() const3050 jint InstanceKlass::compute_modifier_flags() const {
3051 jint access = access_flags().as_int();
3052
3053 // But check if it happens to be member class.
3054 InnerClassesIterator iter(this);
3055 for (; !iter.done(); iter.next()) {
3056 int ioff = iter.inner_class_info_index();
3057 // Inner class attribute can be zero, skip it.
3058 // Strange but true: JVM spec. allows null inner class refs.
3059 if (ioff == 0) continue;
3060
3061 // only look at classes that are already loaded
3062 // since we are looking for the flags for our self.
3063 Symbol* inner_name = constants()->klass_name_at(ioff);
3064 if (name() == inner_name) {
3065 // This is really a member class.
3066 access = iter.inner_access_flags();
3067 break;
3068 }
3069 }
3070 // Remember to strip ACC_SUPER bit
3071 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
3072 }
3073
jvmti_class_status() const3074 jint InstanceKlass::jvmti_class_status() const {
3075 jint result = 0;
3076
3077 if (is_linked()) {
3078 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3079 }
3080
3081 if (is_initialized()) {
3082 assert(is_linked(), "Class status is not consistent");
3083 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3084 }
3085 if (is_in_error_state()) {
3086 result |= JVMTI_CLASS_STATUS_ERROR;
3087 }
3088 return result;
3089 }
3090
method_at_itable(InstanceKlass * holder,int index,TRAPS)3091 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3092 bool implements_interface; // initialized by method_at_itable_or_null
3093 Method* m = method_at_itable_or_null(holder, index,
3094 implements_interface); // out parameter
3095 if (m != NULL) {
3096 assert(implements_interface, "sanity");
3097 return m;
3098 } else if (implements_interface) {
3099 // Throw AbstractMethodError since corresponding itable slot is empty.
3100 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3101 } else {
3102 // If the interface isn't implemented by the receiver class,
3103 // the VM should throw IncompatibleClassChangeError.
3104 ResourceMark rm(THREAD);
3105 stringStream ss;
3106 bool same_module = (module() == holder->module());
3107 ss.print("Receiver class %s does not implement "
3108 "the interface %s defining the method to be called "
3109 "(%s%s%s)",
3110 external_name(), holder->external_name(),
3111 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3112 (same_module) ? "" : "; ",
3113 (same_module) ? "" : holder->class_in_module_of_loader());
3114 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3115 }
3116 }
3117
method_at_itable_or_null(InstanceKlass * holder,int index,bool & implements_interface)3118 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3119 klassItable itable(this);
3120 for (int i = 0; i < itable.size_offset_table(); i++) {
3121 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3122 if (offset_entry->interface_klass() == holder) {
3123 implements_interface = true;
3124 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3125 Method* m = ime[index].method();
3126 return m;
3127 }
3128 }
3129 implements_interface = false;
3130 return NULL; // offset entry not found
3131 }
3132
vtable_index_of_interface_method(Method * intf_method)3133 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3134 assert(is_linked(), "required");
3135 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3136 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3137
3138 int vtable_index = Method::invalid_vtable_index;
3139 Symbol* name = intf_method->name();
3140 Symbol* signature = intf_method->signature();
3141
3142 // First check in default method array
3143 if (!intf_method->is_abstract() && default_methods() != NULL) {
3144 int index = find_method_index(default_methods(),
3145 name, signature,
3146 Klass::OverpassLookupMode::find,
3147 Klass::StaticLookupMode::find,
3148 Klass::PrivateLookupMode::find);
3149 if (index >= 0) {
3150 vtable_index = default_vtable_indices()->at(index);
3151 }
3152 }
3153 if (vtable_index == Method::invalid_vtable_index) {
3154 // get vtable_index for miranda methods
3155 klassVtable vt = vtable();
3156 vtable_index = vt.index_of_miranda(name, signature);
3157 }
3158 return vtable_index;
3159 }
3160
3161 #if INCLUDE_JVMTI
3162 // update default_methods for redefineclasses for methods that are
3163 // not yet in the vtable due to concurrent subclass define and superinterface
3164 // redefinition
3165 // Note: those in the vtable, should have been updated via adjust_method_entries
adjust_default_methods(bool * trace_name_printed)3166 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3167 // search the default_methods for uses of either obsolete or EMCP methods
3168 if (default_methods() != NULL) {
3169 for (int index = 0; index < default_methods()->length(); index ++) {
3170 Method* old_method = default_methods()->at(index);
3171 if (old_method == NULL || !old_method->is_old()) {
3172 continue; // skip uninteresting entries
3173 }
3174 assert(!old_method->is_deleted(), "default methods may not be deleted");
3175 Method* new_method = old_method->get_new_method();
3176 default_methods()->at_put(index, new_method);
3177
3178 if (log_is_enabled(Info, redefine, class, update)) {
3179 ResourceMark rm;
3180 if (!(*trace_name_printed)) {
3181 log_info(redefine, class, update)
3182 ("adjust: klassname=%s default methods from name=%s",
3183 external_name(), old_method->method_holder()->external_name());
3184 *trace_name_printed = true;
3185 }
3186 log_debug(redefine, class, update, vtables)
3187 ("default method update: %s(%s) ",
3188 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3189 }
3190 }
3191 }
3192 }
3193 #endif // INCLUDE_JVMTI
3194
3195 // On-stack replacement stuff
add_osr_nmethod(nmethod * n)3196 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3197 assert_lock_strong(CompiledMethod_lock);
3198 #ifndef PRODUCT
3199 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3200 assert(prev == NULL || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3201 "redundant OSR recompilation detected. memory leak in CodeCache!");
3202 #endif
3203 // only one compilation can be active
3204 assert(n->is_osr_method(), "wrong kind of nmethod");
3205 n->set_osr_link(osr_nmethods_head());
3206 set_osr_nmethods_head(n);
3207 // Raise the highest osr level if necessary
3208 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3209
3210 // Get rid of the osr methods for the same bci that have lower levels.
3211 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3212 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3213 if (inv != NULL && inv->is_in_use()) {
3214 inv->make_not_entrant();
3215 }
3216 }
3217 }
3218
3219 // Remove osr nmethod from the list. Return true if found and removed.
remove_osr_nmethod(nmethod * n)3220 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3221 // This is a short non-blocking critical region, so the no safepoint check is ok.
3222 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock
3223 , Mutex::_no_safepoint_check_flag);
3224 assert(n->is_osr_method(), "wrong kind of nmethod");
3225 nmethod* last = NULL;
3226 nmethod* cur = osr_nmethods_head();
3227 int max_level = CompLevel_none; // Find the max comp level excluding n
3228 Method* m = n->method();
3229 // Search for match
3230 bool found = false;
3231 while(cur != NULL && cur != n) {
3232 if (m == cur->method()) {
3233 // Find max level before n
3234 max_level = MAX2(max_level, cur->comp_level());
3235 }
3236 last = cur;
3237 cur = cur->osr_link();
3238 }
3239 nmethod* next = NULL;
3240 if (cur == n) {
3241 found = true;
3242 next = cur->osr_link();
3243 if (last == NULL) {
3244 // Remove first element
3245 set_osr_nmethods_head(next);
3246 } else {
3247 last->set_osr_link(next);
3248 }
3249 }
3250 n->set_osr_link(NULL);
3251 cur = next;
3252 while (cur != NULL) {
3253 // Find max level after n
3254 if (m == cur->method()) {
3255 max_level = MAX2(max_level, cur->comp_level());
3256 }
3257 cur = cur->osr_link();
3258 }
3259 m->set_highest_osr_comp_level(max_level);
3260 return found;
3261 }
3262
mark_osr_nmethods(const Method * m)3263 int InstanceKlass::mark_osr_nmethods(const Method* m) {
3264 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock,
3265 Mutex::_no_safepoint_check_flag);
3266 nmethod* osr = osr_nmethods_head();
3267 int found = 0;
3268 while (osr != NULL) {
3269 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3270 if (osr->method() == m) {
3271 osr->mark_for_deoptimization();
3272 found++;
3273 }
3274 osr = osr->osr_link();
3275 }
3276 return found;
3277 }
3278
lookup_osr_nmethod(const Method * m,int bci,int comp_level,bool match_level) const3279 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3280 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock,
3281 Mutex::_no_safepoint_check_flag);
3282 nmethod* osr = osr_nmethods_head();
3283 nmethod* best = NULL;
3284 while (osr != NULL) {
3285 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3286 // There can be a time when a c1 osr method exists but we are waiting
3287 // for a c2 version. When c2 completes its osr nmethod we will trash
3288 // the c1 version and only be able to find the c2 version. However
3289 // while we overflow in the c1 code at back branches we don't want to
3290 // try and switch to the same code as we are already running
3291
3292 if (osr->method() == m &&
3293 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3294 if (match_level) {
3295 if (osr->comp_level() == comp_level) {
3296 // Found a match - return it.
3297 return osr;
3298 }
3299 } else {
3300 if (best == NULL || (osr->comp_level() > best->comp_level())) {
3301 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3302 // Found the best possible - return it.
3303 return osr;
3304 }
3305 best = osr;
3306 }
3307 }
3308 }
3309 osr = osr->osr_link();
3310 }
3311
3312 assert(match_level == false || best == NULL, "shouldn't pick up anything if match_level is set");
3313 if (best != NULL && best->comp_level() >= comp_level) {
3314 return best;
3315 }
3316 return NULL;
3317 }
3318
3319 // -----------------------------------------------------------------------------------------------------
3320 // Printing
3321
3322 #define BULLET " - "
3323
3324 static const char* state_names[] = {
3325 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3326 };
3327
print_vtable(intptr_t * start,int len,outputStream * st)3328 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3329 for (int i = 0; i < len; i++) {
3330 intptr_t e = start[i];
3331 st->print("%d : " INTPTR_FORMAT, i, e);
3332 if (MetaspaceObj::is_valid((Metadata*)e)) {
3333 st->print(" ");
3334 ((Metadata*)e)->print_value_on(st);
3335 }
3336 st->cr();
3337 }
3338 }
3339
print_vtable(vtableEntry * start,int len,outputStream * st)3340 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3341 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3342 }
3343
print_on(outputStream * st) const3344 void InstanceKlass::print_on(outputStream* st) const {
3345 assert(is_klass(), "must be klass");
3346 Klass::print_on(st);
3347
3348 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3349 st->print(BULLET"klass size: %d", size()); st->cr();
3350 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3351 st->print(BULLET"state: "); st->print_cr("%s", state_names[_init_state]);
3352 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3353 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3354 st->print(BULLET"sub: ");
3355 Klass* sub = subklass();
3356 int n;
3357 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
3358 if (n < MaxSubklassPrintSize) {
3359 sub->print_value_on(st);
3360 st->print(" ");
3361 }
3362 }
3363 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3364 st->cr();
3365
3366 if (is_interface()) {
3367 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3368 if (nof_implementors() == 1) {
3369 st->print_cr(BULLET"implementor: ");
3370 st->print(" ");
3371 implementor()->print_value_on(st);
3372 st->cr();
3373 }
3374 }
3375
3376 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3377 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3378 if (Verbose || WizardMode) {
3379 Array<Method*>* method_array = methods();
3380 for (int i = 0; i < method_array->length(); i++) {
3381 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3382 }
3383 }
3384 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3385 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3386 if (Verbose && default_methods() != NULL) {
3387 Array<Method*>* method_array = default_methods();
3388 for (int i = 0; i < method_array->length(); i++) {
3389 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3390 }
3391 }
3392 if (default_vtable_indices() != NULL) {
3393 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
3394 }
3395 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3396 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3397 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3398 if (class_loader_data() != NULL) {
3399 st->print(BULLET"class loader data: ");
3400 class_loader_data()->print_value_on(st);
3401 st->cr();
3402 }
3403 if (source_file_name() != NULL) {
3404 st->print(BULLET"source file: ");
3405 source_file_name()->print_value_on(st);
3406 st->cr();
3407 }
3408 if (source_debug_extension() != NULL) {
3409 st->print(BULLET"source debug extension: ");
3410 st->print("%s", source_debug_extension());
3411 st->cr();
3412 }
3413 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
3414 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
3415 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
3416 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
3417 {
3418 bool have_pv = false;
3419 // previous versions are linked together through the InstanceKlass
3420 for (InstanceKlass* pv_node = previous_versions();
3421 pv_node != NULL;
3422 pv_node = pv_node->previous_versions()) {
3423 if (!have_pv)
3424 st->print(BULLET"previous version: ");
3425 have_pv = true;
3426 pv_node->constants()->print_value_on(st);
3427 }
3428 if (have_pv) st->cr();
3429 }
3430
3431 if (generic_signature() != NULL) {
3432 st->print(BULLET"generic signature: ");
3433 generic_signature()->print_value_on(st);
3434 st->cr();
3435 }
3436 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3437 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3438 if (record_components() != NULL) {
3439 st->print(BULLET"record components: "); record_components()->print_value_on(st); st->cr();
3440 }
3441 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
3442 if (java_mirror() != NULL) {
3443 st->print(BULLET"java mirror: ");
3444 java_mirror()->print_value_on(st);
3445 st->cr();
3446 } else {
3447 st->print_cr(BULLET"java mirror: NULL");
3448 }
3449 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3450 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3451 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3452 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3453 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3454 FieldPrinter print_static_field(st);
3455 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3456 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3457 FieldPrinter print_nonstatic_field(st);
3458 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3459 ik->do_nonstatic_fields(&print_nonstatic_field);
3460
3461 st->print(BULLET"non-static oop maps: ");
3462 OopMapBlock* map = start_of_nonstatic_oop_maps();
3463 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3464 while (map < end_map) {
3465 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3466 map++;
3467 }
3468 st->cr();
3469 }
3470
print_value_on(outputStream * st) const3471 void InstanceKlass::print_value_on(outputStream* st) const {
3472 assert(is_klass(), "must be klass");
3473 if (Verbose || WizardMode) access_flags().print_on(st);
3474 name()->print_value_on(st);
3475 }
3476
do_field(fieldDescriptor * fd)3477 void FieldPrinter::do_field(fieldDescriptor* fd) {
3478 _st->print(BULLET);
3479 if (_obj == NULL) {
3480 fd->print_on(_st);
3481 _st->cr();
3482 } else {
3483 fd->print_on_for(_st, _obj);
3484 _st->cr();
3485 }
3486 }
3487
3488
oop_print_on(oop obj,outputStream * st)3489 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3490 Klass::oop_print_on(obj, st);
3491
3492 if (this == vmClasses::String_klass()) {
3493 typeArrayOop value = java_lang_String::value(obj);
3494 juint length = java_lang_String::length(obj);
3495 if (value != NULL &&
3496 value->is_typeArray() &&
3497 length <= (juint) value->length()) {
3498 st->print(BULLET"string: ");
3499 java_lang_String::print(obj, st);
3500 st->cr();
3501 if (!WizardMode) return; // that is enough
3502 }
3503 }
3504
3505 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3506 FieldPrinter print_field(st, obj);
3507 do_nonstatic_fields(&print_field);
3508
3509 if (this == vmClasses::Class_klass()) {
3510 st->print(BULLET"signature: ");
3511 java_lang_Class::print_signature(obj, st);
3512 st->cr();
3513 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3514 st->print(BULLET"fake entry for mirror: ");
3515 Metadata::print_value_on_maybe_null(st, mirrored_klass);
3516 st->cr();
3517 Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3518 st->print(BULLET"fake entry for array: ");
3519 Metadata::print_value_on_maybe_null(st, array_klass);
3520 st->cr();
3521 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3522 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3523 Klass* real_klass = java_lang_Class::as_Klass(obj);
3524 if (real_klass != NULL && real_klass->is_instance_klass()) {
3525 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3526 }
3527 } else if (this == vmClasses::MethodType_klass()) {
3528 st->print(BULLET"signature: ");
3529 java_lang_invoke_MethodType::print_signature(obj, st);
3530 st->cr();
3531 }
3532 }
3533
3534 #ifndef PRODUCT
3535
verify_itable_index(int i)3536 bool InstanceKlass::verify_itable_index(int i) {
3537 int method_count = klassItable::method_count_for_interface(this);
3538 assert(i >= 0 && i < method_count, "index out of bounds");
3539 return true;
3540 }
3541
3542 #endif //PRODUCT
3543
oop_print_value_on(oop obj,outputStream * st)3544 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3545 st->print("a ");
3546 name()->print_value_on(st);
3547 obj->print_address_on(st);
3548 if (this == vmClasses::String_klass()
3549 && java_lang_String::value(obj) != NULL) {
3550 ResourceMark rm;
3551 int len = java_lang_String::length(obj);
3552 int plen = (len < 24 ? len : 12);
3553 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3554 st->print(" = \"%s\"", str);
3555 if (len > plen)
3556 st->print("...[%d]", len);
3557 } else if (this == vmClasses::Class_klass()) {
3558 Klass* k = java_lang_Class::as_Klass(obj);
3559 st->print(" = ");
3560 if (k != NULL) {
3561 k->print_value_on(st);
3562 } else {
3563 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3564 st->print("%s", tname ? tname : "type?");
3565 }
3566 } else if (this == vmClasses::MethodType_klass()) {
3567 st->print(" = ");
3568 java_lang_invoke_MethodType::print_signature(obj, st);
3569 } else if (java_lang_boxing_object::is_instance(obj)) {
3570 st->print(" = ");
3571 java_lang_boxing_object::print(obj, st);
3572 } else if (this == vmClasses::LambdaForm_klass()) {
3573 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3574 if (vmentry != NULL) {
3575 st->print(" => ");
3576 vmentry->print_value_on(st);
3577 }
3578 } else if (this == vmClasses::MemberName_klass()) {
3579 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3580 if (vmtarget != NULL) {
3581 st->print(" = ");
3582 vmtarget->print_value_on(st);
3583 } else {
3584 oop clazz = java_lang_invoke_MemberName::clazz(obj);
3585 oop name = java_lang_invoke_MemberName::name(obj);
3586 if (clazz != NULL) {
3587 clazz->print_value_on(st);
3588 } else {
3589 st->print("NULL");
3590 }
3591 st->print(".");
3592 if (name != NULL) {
3593 name->print_value_on(st);
3594 } else {
3595 st->print("NULL");
3596 }
3597 }
3598 }
3599 }
3600
internal_name() const3601 const char* InstanceKlass::internal_name() const {
3602 return external_name();
3603 }
3604
print_class_load_logging(ClassLoaderData * loader_data,const ModuleEntry * module_entry,const ClassFileStream * cfs) const3605 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3606 const ModuleEntry* module_entry,
3607 const ClassFileStream* cfs) const {
3608 log_to_classlist();
3609
3610 if (!log_is_enabled(Info, class, load)) {
3611 return;
3612 }
3613
3614 ResourceMark rm;
3615 LogMessage(class, load) msg;
3616 stringStream info_stream;
3617
3618 // Name and class hierarchy info
3619 info_stream.print("%s", external_name());
3620
3621 // Source
3622 if (cfs != NULL) {
3623 if (cfs->source() != NULL) {
3624 const char* module_name = (module_entry->name() == NULL) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3625 if (module_name != NULL) {
3626 // When the boot loader created the stream, it didn't know the module name
3627 // yet. Let's format it now.
3628 if (cfs->from_boot_loader_modules_image()) {
3629 info_stream.print(" source: jrt:/%s", module_name);
3630 } else {
3631 info_stream.print(" source: %s", cfs->source());
3632 }
3633 } else {
3634 info_stream.print(" source: %s", cfs->source());
3635 }
3636 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3637 Thread* current = Thread::current();
3638 Klass* caller = current->is_Java_thread() ?
3639 current->as_Java_thread()->security_get_caller_class(1):
3640 NULL;
3641 // caller can be NULL, for example, during a JVMTI VM_Init hook
3642 if (caller != NULL) {
3643 info_stream.print(" source: instance of %s", caller->external_name());
3644 } else {
3645 // source is unknown
3646 }
3647 } else {
3648 oop class_loader = loader_data->class_loader();
3649 info_stream.print(" source: %s", class_loader->klass()->external_name());
3650 }
3651 } else {
3652 assert(this->is_shared(), "must be");
3653 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3654 info_stream.print(" source: shared objects file (top)");
3655 } else {
3656 info_stream.print(" source: shared objects file");
3657 }
3658 }
3659
3660 msg.info("%s", info_stream.as_string());
3661
3662 if (log_is_enabled(Debug, class, load)) {
3663 stringStream debug_stream;
3664
3665 // Class hierarchy info
3666 debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3667 p2i(this), p2i(superklass()));
3668
3669 // Interfaces
3670 if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3671 debug_stream.print(" interfaces:");
3672 int length = local_interfaces()->length();
3673 for (int i = 0; i < length; i++) {
3674 debug_stream.print(" " INTPTR_FORMAT,
3675 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3676 }
3677 }
3678
3679 // Class loader
3680 debug_stream.print(" loader: [");
3681 loader_data->print_value_on(&debug_stream);
3682 debug_stream.print("]");
3683
3684 // Classfile checksum
3685 if (cfs) {
3686 debug_stream.print(" bytes: %d checksum: %08x",
3687 cfs->length(),
3688 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3689 cfs->length()));
3690 }
3691
3692 msg.debug("%s", debug_stream.as_string());
3693 }
3694 }
3695
3696 // Verification
3697
3698 class VerifyFieldClosure: public BasicOopIterateClosure {
3699 protected:
do_oop_work(T * p)3700 template <class T> void do_oop_work(T* p) {
3701 oop obj = RawAccess<>::oop_load(p);
3702 if (!oopDesc::is_oop_or_null(obj)) {
3703 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3704 Universe::print_on(tty);
3705 guarantee(false, "boom");
3706 }
3707 }
3708 public:
do_oop(oop * p)3709 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
do_oop(narrowOop * p)3710 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3711 };
3712
verify_on(outputStream * st)3713 void InstanceKlass::verify_on(outputStream* st) {
3714 #ifndef PRODUCT
3715 // Avoid redundant verifies, this really should be in product.
3716 if (_verify_count == Universe::verify_count()) return;
3717 _verify_count = Universe::verify_count();
3718 #endif
3719
3720 // Verify Klass
3721 Klass::verify_on(st);
3722
3723 // Verify that klass is present in ClassLoaderData
3724 guarantee(class_loader_data()->contains_klass(this),
3725 "this class isn't found in class loader data");
3726
3727 // Verify vtables
3728 if (is_linked()) {
3729 // $$$ This used to be done only for m/s collections. Doing it
3730 // always seemed a valid generalization. (DLD -- 6/00)
3731 vtable().verify(st);
3732 }
3733
3734 // Verify first subklass
3735 if (subklass() != NULL) {
3736 guarantee(subklass()->is_klass(), "should be klass");
3737 }
3738
3739 // Verify siblings
3740 Klass* super = this->super();
3741 Klass* sib = next_sibling();
3742 if (sib != NULL) {
3743 if (sib == this) {
3744 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3745 }
3746
3747 guarantee(sib->is_klass(), "should be klass");
3748 guarantee(sib->super() == super, "siblings should have same superklass");
3749 }
3750
3751 // Verify local interfaces
3752 if (local_interfaces()) {
3753 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
3754 for (int j = 0; j < local_interfaces->length(); j++) {
3755 InstanceKlass* e = local_interfaces->at(j);
3756 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3757 }
3758 }
3759
3760 // Verify transitive interfaces
3761 if (transitive_interfaces() != NULL) {
3762 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
3763 for (int j = 0; j < transitive_interfaces->length(); j++) {
3764 InstanceKlass* e = transitive_interfaces->at(j);
3765 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3766 }
3767 }
3768
3769 // Verify methods
3770 if (methods() != NULL) {
3771 Array<Method*>* methods = this->methods();
3772 for (int j = 0; j < methods->length(); j++) {
3773 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3774 }
3775 for (int j = 0; j < methods->length() - 1; j++) {
3776 Method* m1 = methods->at(j);
3777 Method* m2 = methods->at(j + 1);
3778 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3779 }
3780 }
3781
3782 // Verify method ordering
3783 if (method_ordering() != NULL) {
3784 Array<int>* method_ordering = this->method_ordering();
3785 int length = method_ordering->length();
3786 if (JvmtiExport::can_maintain_original_method_order() ||
3787 ((UseSharedSpaces || Arguments::is_dumping_archive()) && length != 0)) {
3788 guarantee(length == methods()->length(), "invalid method ordering length");
3789 jlong sum = 0;
3790 for (int j = 0; j < length; j++) {
3791 int original_index = method_ordering->at(j);
3792 guarantee(original_index >= 0, "invalid method ordering index");
3793 guarantee(original_index < length, "invalid method ordering index");
3794 sum += original_index;
3795 }
3796 // Verify sum of indices 0,1,...,length-1
3797 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3798 } else {
3799 guarantee(length == 0, "invalid method ordering length");
3800 }
3801 }
3802
3803 // Verify default methods
3804 if (default_methods() != NULL) {
3805 Array<Method*>* methods = this->default_methods();
3806 for (int j = 0; j < methods->length(); j++) {
3807 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3808 }
3809 for (int j = 0; j < methods->length() - 1; j++) {
3810 Method* m1 = methods->at(j);
3811 Method* m2 = methods->at(j + 1);
3812 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3813 }
3814 }
3815
3816 // Verify JNI static field identifiers
3817 if (jni_ids() != NULL) {
3818 jni_ids()->verify(this);
3819 }
3820
3821 // Verify other fields
3822 if (constants() != NULL) {
3823 guarantee(constants()->is_constantPool(), "should be constant pool");
3824 }
3825 }
3826
oop_verify_on(oop obj,outputStream * st)3827 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3828 Klass::oop_verify_on(obj, st);
3829 VerifyFieldClosure blk;
3830 obj->oop_iterate(&blk);
3831 }
3832
3833
3834 // JNIid class for jfieldIDs only
3835 // Note to reviewers:
3836 // These JNI functions are just moved over to column 1 and not changed
3837 // in the compressed oops workspace.
JNIid(Klass * holder,int offset,JNIid * next)3838 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3839 _holder = holder;
3840 _offset = offset;
3841 _next = next;
3842 debug_only(_is_static_field_id = false;)
3843 }
3844
3845
find(int offset)3846 JNIid* JNIid::find(int offset) {
3847 JNIid* current = this;
3848 while (current != NULL) {
3849 if (current->offset() == offset) return current;
3850 current = current->next();
3851 }
3852 return NULL;
3853 }
3854
deallocate(JNIid * current)3855 void JNIid::deallocate(JNIid* current) {
3856 while (current != NULL) {
3857 JNIid* next = current->next();
3858 delete current;
3859 current = next;
3860 }
3861 }
3862
3863
verify(Klass * holder)3864 void JNIid::verify(Klass* holder) {
3865 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3866 int end_field_offset;
3867 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3868
3869 JNIid* current = this;
3870 while (current != NULL) {
3871 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3872 #ifdef ASSERT
3873 int o = current->offset();
3874 if (current->is_static_field_id()) {
3875 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3876 }
3877 #endif
3878 current = current->next();
3879 }
3880 }
3881
set_init_state(ClassState state)3882 void InstanceKlass::set_init_state(ClassState state) {
3883 #ifdef ASSERT
3884 bool good_state = is_shared() ? (_init_state <= state)
3885 : (_init_state < state);
3886 assert(good_state || state == allocated, "illegal state transition");
3887 #endif
3888 assert(_init_thread == NULL, "should be cleared before state change");
3889 _init_state = (u1)state;
3890 }
3891
3892 #if INCLUDE_JVMTI
3893
3894 // RedefineClasses() support for previous versions
3895
3896 // Globally, there is at least one previous version of a class to walk
3897 // during class unloading, which is saved because old methods in the class
3898 // are still running. Otherwise the previous version list is cleaned up.
3899 bool InstanceKlass::_has_previous_versions = false;
3900
3901 // Returns true if there are previous versions of a class for class
3902 // unloading only. Also resets the flag to false. purge_previous_version
3903 // will set the flag to true if there are any left, i.e., if there's any
3904 // work to do for next time. This is to avoid the expensive code cache
3905 // walk in CLDG::clean_deallocate_lists().
has_previous_versions_and_reset()3906 bool InstanceKlass::has_previous_versions_and_reset() {
3907 bool ret = _has_previous_versions;
3908 log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3909 ret ? "true" : "false");
3910 _has_previous_versions = false;
3911 return ret;
3912 }
3913
3914 // Purge previous versions before adding new previous versions of the class and
3915 // during class unloading.
purge_previous_version_list()3916 void InstanceKlass::purge_previous_version_list() {
3917 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3918 assert(has_been_redefined(), "Should only be called for main class");
3919
3920 // Quick exit.
3921 if (previous_versions() == NULL) {
3922 return;
3923 }
3924
3925 // This klass has previous versions so see what we can cleanup
3926 // while it is safe to do so.
3927
3928 int deleted_count = 0; // leave debugging breadcrumbs
3929 int live_count = 0;
3930 ClassLoaderData* loader_data = class_loader_data();
3931 assert(loader_data != NULL, "should never be null");
3932
3933 ResourceMark rm;
3934 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3935
3936 // previous versions are linked together through the InstanceKlass
3937 InstanceKlass* pv_node = previous_versions();
3938 InstanceKlass* last = this;
3939 int version = 0;
3940
3941 // check the previous versions list
3942 for (; pv_node != NULL; ) {
3943
3944 ConstantPool* pvcp = pv_node->constants();
3945 assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3946
3947 if (!pvcp->on_stack()) {
3948 // If the constant pool isn't on stack, none of the methods
3949 // are executing. Unlink this previous_version.
3950 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3951 // so will be deallocated during the next phase of class unloading.
3952 log_trace(redefine, class, iklass, purge)
3953 ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3954 // For debugging purposes.
3955 pv_node->set_is_scratch_class();
3956 // Unlink from previous version list.
3957 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3958 InstanceKlass* next = pv_node->previous_versions();
3959 pv_node->link_previous_versions(NULL); // point next to NULL
3960 last->link_previous_versions(next);
3961 // Delete this node directly. Nothing is referring to it and we don't
3962 // want it to increase the counter for metadata to delete in CLDG.
3963 MetadataFactory::free_metadata(loader_data, pv_node);
3964 pv_node = next;
3965 deleted_count++;
3966 version++;
3967 continue;
3968 } else {
3969 log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3970 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3971 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3972 live_count++;
3973 // found a previous version for next time we do class unloading
3974 _has_previous_versions = true;
3975 }
3976
3977 // next previous version
3978 last = pv_node;
3979 pv_node = pv_node->previous_versions();
3980 version++;
3981 }
3982 log_trace(redefine, class, iklass, purge)
3983 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3984 }
3985
mark_newly_obsolete_methods(Array<Method * > * old_methods,int emcp_method_count)3986 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3987 int emcp_method_count) {
3988 int obsolete_method_count = old_methods->length() - emcp_method_count;
3989
3990 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3991 _previous_versions != NULL) {
3992 // We have a mix of obsolete and EMCP methods so we have to
3993 // clear out any matching EMCP method entries the hard way.
3994 int local_count = 0;
3995 for (int i = 0; i < old_methods->length(); i++) {
3996 Method* old_method = old_methods->at(i);
3997 if (old_method->is_obsolete()) {
3998 // only obsolete methods are interesting
3999 Symbol* m_name = old_method->name();
4000 Symbol* m_signature = old_method->signature();
4001
4002 // previous versions are linked together through the InstanceKlass
4003 int j = 0;
4004 for (InstanceKlass* prev_version = _previous_versions;
4005 prev_version != NULL;
4006 prev_version = prev_version->previous_versions(), j++) {
4007
4008 Array<Method*>* method_refs = prev_version->methods();
4009 for (int k = 0; k < method_refs->length(); k++) {
4010 Method* method = method_refs->at(k);
4011
4012 if (!method->is_obsolete() &&
4013 method->name() == m_name &&
4014 method->signature() == m_signature) {
4015 // The current RedefineClasses() call has made all EMCP
4016 // versions of this method obsolete so mark it as obsolete
4017 log_trace(redefine, class, iklass, add)
4018 ("%s(%s): flush obsolete method @%d in version @%d",
4019 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4020
4021 method->set_is_obsolete();
4022 break;
4023 }
4024 }
4025
4026 // The previous loop may not find a matching EMCP method, but
4027 // that doesn't mean that we can optimize and not go any
4028 // further back in the PreviousVersion generations. The EMCP
4029 // method for this generation could have already been made obsolete,
4030 // but there still may be an older EMCP method that has not
4031 // been made obsolete.
4032 }
4033
4034 if (++local_count >= obsolete_method_count) {
4035 // no more obsolete methods so bail out now
4036 break;
4037 }
4038 }
4039 }
4040 }
4041 }
4042
4043 // Save the scratch_class as the previous version if any of the methods are running.
4044 // The previous_versions are used to set breakpoints in EMCP methods and they are
4045 // also used to clean MethodData links to redefined methods that are no longer running.
add_previous_version(InstanceKlass * scratch_class,int emcp_method_count)4046 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4047 int emcp_method_count) {
4048 assert(Thread::current()->is_VM_thread(),
4049 "only VMThread can add previous versions");
4050
4051 ResourceMark rm;
4052 log_trace(redefine, class, iklass, add)
4053 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4054
4055 // Clean out old previous versions for this class
4056 purge_previous_version_list();
4057
4058 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4059 // a previous redefinition may be made obsolete by this redefinition.
4060 Array<Method*>* old_methods = scratch_class->methods();
4061 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4062
4063 // If the constant pool for this previous version of the class
4064 // is not marked as being on the stack, then none of the methods
4065 // in this previous version of the class are on the stack so
4066 // we don't need to add this as a previous version.
4067 ConstantPool* cp_ref = scratch_class->constants();
4068 if (!cp_ref->on_stack()) {
4069 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4070 // For debugging purposes.
4071 scratch_class->set_is_scratch_class();
4072 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4073 return;
4074 }
4075
4076 // Add previous version if any methods are still running.
4077 // Set has_previous_version flag for processing during class unloading.
4078 _has_previous_versions = true;
4079 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4080 assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
4081 scratch_class->link_previous_versions(previous_versions());
4082 link_previous_versions(scratch_class);
4083 } // end add_previous_version()
4084
4085 #endif // INCLUDE_JVMTI
4086
method_with_idnum(int idnum)4087 Method* InstanceKlass::method_with_idnum(int idnum) {
4088 Method* m = NULL;
4089 if (idnum < methods()->length()) {
4090 m = methods()->at(idnum);
4091 }
4092 if (m == NULL || m->method_idnum() != idnum) {
4093 for (int index = 0; index < methods()->length(); ++index) {
4094 m = methods()->at(index);
4095 if (m->method_idnum() == idnum) {
4096 return m;
4097 }
4098 }
4099 // None found, return null for the caller to handle.
4100 return NULL;
4101 }
4102 return m;
4103 }
4104
4105
method_with_orig_idnum(int idnum)4106 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4107 if (idnum >= methods()->length()) {
4108 return NULL;
4109 }
4110 Method* m = methods()->at(idnum);
4111 if (m != NULL && m->orig_method_idnum() == idnum) {
4112 return m;
4113 }
4114 // Obsolete method idnum does not match the original idnum
4115 for (int index = 0; index < methods()->length(); ++index) {
4116 m = methods()->at(index);
4117 if (m->orig_method_idnum() == idnum) {
4118 return m;
4119 }
4120 }
4121 // None found, return null for the caller to handle.
4122 return NULL;
4123 }
4124
4125
method_with_orig_idnum(int idnum,int version)4126 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4127 InstanceKlass* holder = get_klass_version(version);
4128 if (holder == NULL) {
4129 return NULL; // The version of klass is gone, no method is found
4130 }
4131 Method* method = holder->method_with_orig_idnum(idnum);
4132 return method;
4133 }
4134
4135 #if INCLUDE_JVMTI
get_cached_class_file()4136 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4137 return _cached_class_file;
4138 }
4139
get_cached_class_file_len()4140 jint InstanceKlass::get_cached_class_file_len() {
4141 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4142 }
4143
get_cached_class_file_bytes()4144 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4145 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4146 }
4147 #endif
4148
is_shareable() const4149 bool InstanceKlass::is_shareable() const {
4150 #if INCLUDE_CDS
4151 ClassLoaderData* loader_data = class_loader_data();
4152 if (!SystemDictionaryShared::is_sharing_possible(loader_data)) {
4153 return false;
4154 }
4155
4156 if (is_hidden()) {
4157 return false;
4158 }
4159
4160 if (module()->is_patched()) {
4161 return false;
4162 }
4163
4164 return true;
4165 #else
4166 return false;
4167 #endif
4168 }
4169
log_to_classlist() const4170 void InstanceKlass::log_to_classlist() const {
4171 #if INCLUDE_CDS
4172 ResourceMark rm;
4173 if (ClassListWriter::is_enabled()) {
4174 if (!ClassLoader::has_jrt_entry()) {
4175 warning("DumpLoadedClassList and CDS are not supported in exploded build");
4176 DumpLoadedClassList = NULL;
4177 return;
4178 }
4179 if (is_shareable()) {
4180 ClassListWriter w;
4181 w.stream()->print_cr("%s", name()->as_C_string());
4182 w.stream()->flush();
4183 }
4184 }
4185 #endif // INCLUDE_CDS
4186 }
4187
4188 // Make a step iterating over the class hierarchy under the root class.
4189 // Skips subclasses if requested.
next()4190 void ClassHierarchyIterator::next() {
4191 assert(_current != NULL, "required");
4192 if (_visit_subclasses && _current->subklass() != NULL) {
4193 _current = _current->subklass();
4194 return; // visit next subclass
4195 }
4196 _visit_subclasses = true; // reset
4197 while (_current->next_sibling() == NULL && _current != _root) {
4198 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4199 }
4200 if (_current == _root) {
4201 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4202 _current = NULL;
4203 return;
4204 }
4205 _current = _current->next_sibling();
4206 return; // visit next sibling subclass
4207 }
4208