1 /*
2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jvm.h"
27 #include "aot/aotLoader.hpp"
28 #include "classfile/classFileParser.hpp"
29 #include "classfile/classFileStream.hpp"
30 #include "classfile/classLoader.hpp"
31 #include "classfile/classLoaderData.inline.hpp"
32 #include "classfile/javaClasses.hpp"
33 #include "classfile/moduleEntry.hpp"
34 #include "classfile/systemDictionary.hpp"
35 #include "classfile/systemDictionaryShared.hpp"
36 #include "classfile/verifier.hpp"
37 #include "classfile/vmSymbols.hpp"
38 #include "code/dependencyContext.hpp"
39 #include "compiler/compileBroker.hpp"
40 #include "gc/shared/collectedHeap.inline.hpp"
41 #include "interpreter/oopMapCache.hpp"
42 #include "interpreter/rewriter.hpp"
43 #include "jvmtifiles/jvmti.h"
44 #include "logging/log.hpp"
45 #include "logging/logMessage.hpp"
46 #include "logging/logStream.hpp"
47 #include "memory/allocation.inline.hpp"
48 #include "memory/heapInspection.hpp"
49 #include "memory/iterator.inline.hpp"
50 #include "memory/metadataFactory.hpp"
51 #include "memory/metaspaceClosure.hpp"
52 #include "memory/metaspaceShared.hpp"
53 #include "memory/oopFactory.hpp"
54 #include "memory/resourceArea.hpp"
55 #include "oops/fieldStreams.hpp"
56 #include "oops/constantPool.hpp"
57 #include "oops/instanceClassLoaderKlass.hpp"
58 #include "oops/instanceKlass.inline.hpp"
59 #include "oops/instanceMirrorKlass.hpp"
60 #include "oops/instanceOop.hpp"
61 #include "oops/klass.inline.hpp"
62 #include "oops/method.hpp"
63 #include "oops/oop.inline.hpp"
64 #include "oops/symbol.hpp"
65 #include "oops/valueKlass.hpp"
66 #include "prims/jvmtiExport.hpp"
67 #include "prims/jvmtiRedefineClasses.hpp"
68 #include "prims/jvmtiThreadState.hpp"
69 #include "prims/methodComparator.hpp"
70 #include "runtime/atomic.hpp"
71 #include "runtime/fieldDescriptor.inline.hpp"
72 #include "runtime/handles.inline.hpp"
73 #include "runtime/javaCalls.hpp"
74 #include "runtime/mutexLocker.hpp"
75 #include "runtime/orderAccess.hpp"
76 #include "runtime/thread.inline.hpp"
77 #include "services/classLoadingService.hpp"
78 #include "services/threadService.hpp"
79 #include "utilities/dtrace.hpp"
80 #include "utilities/events.hpp"
81 #include "utilities/macros.hpp"
82 #include "utilities/stringUtils.hpp"
83 #ifdef COMPILER1
84 #include "c1/c1_Compiler.hpp"
85 #endif
86 #if INCLUDE_JFR
87 #include "jfr/jfrEvents.hpp"
88 #endif
89
90
91 #ifdef DTRACE_ENABLED
92
93
94 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
95 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
96 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
97 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
98 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
99 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
100 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
101 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
102 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
103 { \
104 char* data = NULL; \
105 int len = 0; \
106 Symbol* clss_name = name(); \
107 if (clss_name != NULL) { \
108 data = (char*)clss_name->bytes(); \
109 len = clss_name->utf8_length(); \
110 } \
111 HOTSPOT_CLASS_INITIALIZATION_##type( \
112 data, len, (void*)class_loader(), thread_type); \
113 }
114
115 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
116 { \
117 char* data = NULL; \
118 int len = 0; \
119 Symbol* clss_name = name(); \
120 if (clss_name != NULL) { \
121 data = (char*)clss_name->bytes(); \
122 len = clss_name->utf8_length(); \
123 } \
124 HOTSPOT_CLASS_INITIALIZATION_##type( \
125 data, len, (void*)class_loader(), thread_type, wait); \
126 }
127
128 #else // ndef DTRACE_ENABLED
129
130 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
131 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
132
133 #endif // ndef DTRACE_ENABLED
134
135 static inline bool is_class_loader(const Symbol* class_name,
136 const ClassFileParser& parser) {
137 assert(class_name != NULL, "invariant");
138
139 if (class_name == vmSymbols::java_lang_ClassLoader()) {
140 return true;
141 }
142
143 if (SystemDictionary::ClassLoader_klass_loaded()) {
144 const Klass* const super_klass = parser.super_klass();
145 if (super_klass != NULL) {
146 if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
147 return true;
148 }
149 }
150 }
151 return false;
152 }
153
154 // called to verify that k is a member of this nest
155 bool InstanceKlass::has_nest_member(InstanceKlass* k, TRAPS) const {
156 if (_nest_members == NULL || _nest_members == Universe::the_empty_short_array()) {
157 if (log_is_enabled(Trace, class, nestmates)) {
158 ResourceMark rm(THREAD);
159 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
160 k->external_name(), this->external_name());
161 }
162 return false;
163 }
164
165 if (log_is_enabled(Trace, class, nestmates)) {
166 ResourceMark rm(THREAD);
167 log_trace(class, nestmates)("Checking nest membership of %s in %s",
168 k->external_name(), this->external_name());
169 }
170
171 // Check for a resolved cp entry , else fall back to a name check.
172 // We don't want to resolve any class other than the one being checked.
173 for (int i = 0; i < _nest_members->length(); i++) {
174 int cp_index = _nest_members->at(i);
175 if (_constants->tag_at(cp_index).is_klass()) {
176 Klass* k2 = _constants->klass_at(cp_index, CHECK_false);
177 if (k2 == k) {
178 log_trace(class, nestmates)("- class is listed at nest_members[%d] => cp[%d]", i, cp_index);
179 return true;
180 }
181 }
182 else {
183 Symbol* name = _constants->klass_name_at(cp_index);
184 if (name == k->name()) {
185 log_trace(class, nestmates)("- Found it at nest_members[%d] => cp[%d]", i, cp_index);
186
187 // Names match so check actual klass - this may trigger class loading if
188 // it doesn't match (though that should be impossible). But to be safe we
189 // have to check for a compiler thread executing here.
190 if (!THREAD->can_call_java() && !_constants->tag_at(cp_index).is_klass()) {
191 log_trace(class, nestmates)("- validation required resolution in an unsuitable thread");
192 return false;
193 }
194
195 Klass* k2 = _constants->klass_at(cp_index, CHECK_false);
196 if (k2 == k) {
197 log_trace(class, nestmates)("- class is listed as a nest member");
198 return true;
199 }
200 else {
201 // same name but different klass!
202 log_trace(class, nestmates)(" - klass comparison failed!");
203 // can't have two names the same, so we're done
204 return false;
205 }
206 }
207 }
208 }
209 log_trace(class, nestmates)("- class is NOT a nest member!");
210 return false;
211 }
212
213 // Return nest-host class, resolving, validating and saving it if needed.
214 // In cases where this is called from a thread that can not do classloading
215 // (such as a native JIT thread) then we simply return NULL, which in turn
216 // causes the access check to return false. Such code will retry the access
217 // from a more suitable environment later.
218 InstanceKlass* InstanceKlass::nest_host(Symbol* validationException, TRAPS) {
219 InstanceKlass* nest_host_k = _nest_host;
220 if (nest_host_k == NULL) {
221 // need to resolve and save our nest-host class. This could be attempted
222 // concurrently but as the result is idempotent and we don't use the class
223 // then we do not need any synchronization beyond what is implicitly used
224 // during class loading.
225 if (_nest_host_index != 0) { // we have a real nest_host
226 // Before trying to resolve check if we're in a suitable context
227 if (!THREAD->can_call_java() && !_constants->tag_at(_nest_host_index).is_klass()) {
228 if (log_is_enabled(Trace, class, nestmates)) {
229 ResourceMark rm(THREAD);
230 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
231 this->external_name());
232 }
233 return NULL;
234 }
235
236 if (log_is_enabled(Trace, class, nestmates)) {
237 ResourceMark rm(THREAD);
238 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
239 this->external_name(),
240 _constants->klass_name_at(_nest_host_index)->as_C_string());
241 }
242
243 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
244 if (HAS_PENDING_EXCEPTION) {
245 Handle exc_h = Handle(THREAD, PENDING_EXCEPTION);
246 if (exc_h->is_a(SystemDictionary::NoClassDefFoundError_klass())) {
247 // throw a new CDNFE with the original as its cause, and a clear msg
248 ResourceMark rm(THREAD);
249 char buf[200];
250 CLEAR_PENDING_EXCEPTION;
251 jio_snprintf(buf, sizeof(buf),
252 "Unable to load nest-host class (%s) of %s",
253 _constants->klass_name_at(_nest_host_index)->as_C_string(),
254 this->external_name());
255 log_trace(class, nestmates)("%s - NoClassDefFoundError", buf);
256 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), buf, exc_h);
257 }
258 // All other exceptions pass through (OOME, StackOverflowError, LinkageErrors etc).
259 return NULL;
260 }
261
262 // A valid nest-host is an instance class in the current package that lists this
263 // class as a nest member. If any of these conditions are not met we post the
264 // requested exception type (if any) and return NULL
265
266 const char* error = NULL;
267
268 // JVMS 5.4.4 indicates package check comes first
269 if (is_same_class_package(k)) {
270
271 // Now check actual membership. We can't be a member if our "host" is
272 // not an instance class.
273 if (k->is_instance_klass()) {
274 nest_host_k = InstanceKlass::cast(k);
275
276 bool is_member = nest_host_k->has_nest_member(this, CHECK_NULL);
277 if (is_member) {
278 // save resolved nest-host value
279 _nest_host = nest_host_k;
280
281 if (log_is_enabled(Trace, class, nestmates)) {
282 ResourceMark rm(THREAD);
283 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
284 this->external_name(), k->external_name());
285 }
286 return nest_host_k;
287 }
288 }
289 error = "current type is not listed as a nest member";
290 } else {
291 error = "types are in different packages";
292 }
293
294 if (log_is_enabled(Trace, class, nestmates)) {
295 ResourceMark rm(THREAD);
296 log_trace(class, nestmates)
297 ("Type %s (loader: %s) is not a nest member of "
298 "resolved type %s (loader: %s): %s",
299 this->external_name(),
300 this->class_loader_data()->loader_name_and_id(),
301 k->external_name(),
302 k->class_loader_data()->loader_name_and_id(),
303 error);
304 }
305
306 if (validationException != NULL && THREAD->can_call_java()) {
307 ResourceMark rm(THREAD);
308 Exceptions::fthrow(THREAD_AND_LOCATION,
309 validationException,
310 "Type %s (loader: %s) is not a nest member of %s (loader: %s): %s",
311 this->external_name(),
312 this->class_loader_data()->loader_name_and_id(),
313 k->external_name(),
314 k->class_loader_data()->loader_name_and_id(),
315 error
316 );
317 }
318 return NULL;
319 } else {
320 if (log_is_enabled(Trace, class, nestmates)) {
321 ResourceMark rm(THREAD);
322 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
323 this->external_name());
324 }
325 // save resolved nest-host value
326 return (_nest_host = this);
327 }
328 }
329 return nest_host_k;
330 }
331
332 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
333 // or we are k's nest_host - all of which is covered by comparing the two
334 // resolved_nest_hosts
335 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
336
337 assert(this != k, "this should be handled by higher-level code");
338
339 // Per JVMS 5.4.4 we first resolve and validate the current class, then
340 // the target class k. Resolution exceptions will be passed on by upper
341 // layers. IncompatibleClassChangeErrors from membership validation failures
342 // will also be passed through.
343
344 Symbol* icce = vmSymbols::java_lang_IncompatibleClassChangeError();
345 InstanceKlass* cur_host = nest_host(icce, CHECK_false);
346 if (cur_host == NULL) {
347 return false;
348 }
349
350 Klass* k_nest_host = k->nest_host(icce, CHECK_false);
351 if (k_nest_host == NULL) {
352 return false;
353 }
354
355 bool access = (cur_host == k_nest_host);
356
357 if (log_is_enabled(Trace, class, nestmates)) {
358 ResourceMark rm(THREAD);
359 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
360 this->external_name(),
361 access ? "" : "NOT ",
362 k->external_name());
363 }
364
365 return access;
366 }
367
368 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
369 const int size = InstanceKlass::size(parser.vtable_size(),
370 parser.itable_size(),
371 nonstatic_oop_map_size(parser.total_oop_map_count()),
372 parser.is_interface(),
373 parser.is_unsafe_anonymous(),
374 should_store_fingerprint(parser.is_unsafe_anonymous()),
375 parser.has_flattenable_fields() ? parser.java_fields_count() : 0,
376 parser.is_value_type());
377
378 const Symbol* const class_name = parser.class_name();
379 assert(class_name != NULL, "invariant");
380 ClassLoaderData* loader_data = parser.loader_data();
381 assert(loader_data != NULL, "invariant");
382
383 InstanceKlass* ik;
384
385 // Allocation
386 if (REF_NONE == parser.reference_type()) {
387 if (class_name == vmSymbols::java_lang_Class()) {
388 // mirror
389 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
390 } else if (is_class_loader(class_name, parser)) {
391 // class loader
392 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
393 } else if (parser.is_value_type()) {
394 // value type
395 ik = new (loader_data, size, THREAD) ValueKlass(parser);
396 } else {
397 // normal
398 ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
399 }
400 } else {
401 // reference
402 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
403 }
404
405 // Check for pending exception before adding to the loader data and incrementing
406 // class count. Can get OOM here.
407 if (HAS_PENDING_EXCEPTION) {
408 return NULL;
409 }
410
411 #ifdef ASSERT
412 assert(ik->size() == size, "");
413 ik->bounds_check((address) ik->start_of_vtable(), false, size);
414 ik->bounds_check((address) ik->start_of_itable(), false, size);
415 ik->bounds_check((address) ik->end_of_itable(), true, size);
416 ik->bounds_check((address) ik->end_of_nonstatic_oop_maps(), true, size);
417 #endif //ASSERT
418 return ik;
419 }
420
421 #ifndef PRODUCT
422 bool InstanceKlass::bounds_check(address addr, bool edge_ok, intptr_t size_in_bytes) const {
423 const char* bad = NULL;
424 address end = NULL;
425 if (addr < (address)this) {
426 bad = "before";
427 } else if (addr == (address)this) {
428 if (edge_ok) return true;
429 bad = "just before";
430 } else if (addr == (end = (address)this + sizeof(intptr_t) * (size_in_bytes < 0 ? size() : size_in_bytes))) {
431 if (edge_ok) return true;
432 bad = "just after";
433 } else if (addr > end) {
434 bad = "after";
435 } else {
436 return true;
437 }
438 tty->print_cr("%s object bounds: " INTPTR_FORMAT " [" INTPTR_FORMAT ".." INTPTR_FORMAT "]",
439 bad, (intptr_t)addr, (intptr_t)this, (intptr_t)end);
440 Verbose = WizardMode = true; this->print(); //@@
441 return false;
442 }
443 #endif //PRODUCT
444
445 // copy method ordering from resource area to Metaspace
446 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
447 if (m != NULL) {
448 // allocate a new array and copy contents (memcpy?)
449 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
450 for (int i = 0; i < m->length(); i++) {
451 _method_ordering->at_put(i, m->at(i));
452 }
453 } else {
454 _method_ordering = Universe::the_empty_int_array();
455 }
456 }
457
458 // create a new array of vtable_indices for default methods
459 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
460 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
461 assert(default_vtable_indices() == NULL, "only create once");
462 set_default_vtable_indices(vtable_indices);
463 return vtable_indices;
464 }
465
466 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind, KlassID id) :
467 Klass(id),
468 _nest_members(NULL),
469 _nest_host_index(0),
470 _nest_host(NULL),
471 _static_field_size(parser.static_field_size()),
472 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
473 _itable_len(parser.itable_size()),
474 _extra_flags(0),
475 _reference_type(parser.reference_type()),
476 _adr_valueklass_fixed_block(NULL) {
477 set_vtable_length(parser.vtable_size());
478 set_kind(kind);
479 set_access_flags(parser.access_flags());
480 set_is_unsafe_anonymous(parser.is_unsafe_anonymous());
481 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
482 false));
483 if (parser.has_flattenable_fields()) {
484 set_has_value_fields();
485 }
486 _java_fields_count = parser.java_fields_count();
487
488 assert(NULL == _methods, "underlying memory not zeroed?");
489 assert(is_instance_klass(), "is layout incorrect?");
490 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
491
492 if (DumpSharedSpaces) {
493 SystemDictionaryShared::init_dumptime_info(this);
494 }
495 }
496
497 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
498 Array<Method*>* methods) {
499 if (methods != NULL && methods != Universe::the_empty_method_array() &&
500 !methods->is_shared()) {
501 for (int i = 0; i < methods->length(); i++) {
502 Method* method = methods->at(i);
503 if (method == NULL) continue; // maybe null if error processing
504 // Only want to delete methods that are not executing for RedefineClasses.
505 // The previous version will point to them so they're not totally dangling
506 assert (!method->on_stack(), "shouldn't be called with methods on stack");
507 MetadataFactory::free_metadata(loader_data, method);
508 }
509 MetadataFactory::free_array<Method*>(loader_data, methods);
510 }
511 }
512
513 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
514 const Klass* super_klass,
515 Array<InstanceKlass*>* local_interfaces,
516 Array<InstanceKlass*>* transitive_interfaces) {
517 // Only deallocate transitive interfaces if not empty, same as super class
518 // or same as local interfaces. See code in parseClassFile.
519 Array<InstanceKlass*>* ti = transitive_interfaces;
520 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
521 // check that the interfaces don't come from super class
522 Array<InstanceKlass*>* sti = (super_klass == NULL) ? NULL :
523 InstanceKlass::cast(super_klass)->transitive_interfaces();
524 if (ti != sti && ti != NULL && !ti->is_shared()) {
525 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
526 }
527 }
528
529 // local interfaces can be empty
530 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
531 local_interfaces != NULL && !local_interfaces->is_shared()) {
532 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
533 }
534 }
535
536 // This function deallocates the metadata and C heap pointers that the
537 // InstanceKlass points to.
538 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
539
540 // Orphan the mirror first, CMS thinks it's still live.
541 if (java_mirror() != NULL) {
542 java_lang_Class::set_klass(java_mirror(), NULL);
543 }
544
545 // Also remove mirror from handles
546 loader_data->remove_handle(_java_mirror);
547
548 // Need to take this class off the class loader data list.
549 loader_data->remove_class(this);
550
551 // The array_klass for this class is created later, after error handling.
552 // For class redefinition, we keep the original class so this scratch class
553 // doesn't have an array class. Either way, assert that there is nothing
554 // to deallocate.
555 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
556
557 // Release C heap allocated data that this might point to, which includes
558 // reference counting symbol names.
559 release_C_heap_structures();
560
561 deallocate_methods(loader_data, methods());
562 set_methods(NULL);
563
564 if (method_ordering() != NULL &&
565 method_ordering() != Universe::the_empty_int_array() &&
566 !method_ordering()->is_shared()) {
567 MetadataFactory::free_array<int>(loader_data, method_ordering());
568 }
569 set_method_ordering(NULL);
570
571 // default methods can be empty
572 if (default_methods() != NULL &&
573 default_methods() != Universe::the_empty_method_array() &&
574 !default_methods()->is_shared()) {
575 MetadataFactory::free_array<Method*>(loader_data, default_methods());
576 }
577 // Do NOT deallocate the default methods, they are owned by superinterfaces.
578 set_default_methods(NULL);
579
580 // default methods vtable indices can be empty
581 if (default_vtable_indices() != NULL &&
582 !default_vtable_indices()->is_shared()) {
583 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
584 }
585 set_default_vtable_indices(NULL);
586
587
588 // This array is in Klass, but remove it with the InstanceKlass since
589 // this place would be the only caller and it can share memory with transitive
590 // interfaces.
591 if (secondary_supers() != NULL &&
592 secondary_supers() != Universe::the_empty_klass_array() &&
593 // see comments in compute_secondary_supers about the following cast
594 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
595 !secondary_supers()->is_shared()) {
596 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
597 }
598 set_secondary_supers(NULL);
599
600 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
601 set_transitive_interfaces(NULL);
602 set_local_interfaces(NULL);
603
604 if (fields() != NULL && !fields()->is_shared()) {
605 MetadataFactory::free_array<jushort>(loader_data, fields());
606 }
607 set_fields(NULL, 0);
608
609 // If a method from a redefined class is using this constant pool, don't
610 // delete it, yet. The new class's previous version will point to this.
611 if (constants() != NULL) {
612 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
613 if (!constants()->is_shared()) {
614 MetadataFactory::free_metadata(loader_data, constants());
615 }
616 // Delete any cached resolution errors for the constant pool
617 SystemDictionary::delete_resolution_error(constants());
618
619 set_constants(NULL);
620 }
621
622 if (inner_classes() != NULL &&
623 inner_classes() != Universe::the_empty_short_array() &&
624 !inner_classes()->is_shared()) {
625 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
626 }
627 set_inner_classes(NULL);
628
629 if (nest_members() != NULL &&
630 nest_members() != Universe::the_empty_short_array() &&
631 !nest_members()->is_shared()) {
632 MetadataFactory::free_array<jushort>(loader_data, nest_members());
633 }
634 set_nest_members(NULL);
635
636 // We should deallocate the Annotations instance if it's not in shared spaces.
637 if (annotations() != NULL && !annotations()->is_shared()) {
638 MetadataFactory::free_metadata(loader_data, annotations());
639 }
640 set_annotations(NULL);
641
642 if (DumpSharedSpaces) {
643 SystemDictionaryShared::remove_dumptime_info(this);
644 }
645 }
646
647 bool InstanceKlass::should_be_initialized() const {
648 return !is_initialized();
649 }
650
651 klassItable InstanceKlass::itable() const {
652 return klassItable(const_cast<InstanceKlass*>(this));
653 }
654
655 void InstanceKlass::eager_initialize(Thread *thread) {
656 if (!EagerInitialization) return;
657
658 if (this->is_not_initialized()) {
659 // abort if the the class has a class initializer
660 if (this->class_initializer() != NULL) return;
661
662 // abort if it is java.lang.Object (initialization is handled in genesis)
663 Klass* super_klass = super();
664 if (super_klass == NULL) return;
665
666 // abort if the super class should be initialized
667 if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
668
669 // call body to expose the this pointer
670 eager_initialize_impl();
671 }
672 }
673
674 // JVMTI spec thinks there are signers and protection domain in the
675 // instanceKlass. These accessors pretend these fields are there.
676 // The hprof specification also thinks these fields are in InstanceKlass.
677 oop InstanceKlass::protection_domain() const {
678 // return the protection_domain from the mirror
679 return java_lang_Class::protection_domain(java_mirror());
680 }
681
682 // To remove these from requires an incompatible change and CCC request.
683 objArrayOop InstanceKlass::signers() const {
684 // return the signers from the mirror
685 return java_lang_Class::signers(java_mirror());
686 }
687
688 oop InstanceKlass::init_lock() const {
689 // return the init lock from the mirror
690 oop lock = java_lang_Class::init_lock(java_mirror());
691 // Prevent reordering with any access of initialization state
692 OrderAccess::loadload();
693 assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
694 "only fully initialized state can have a null lock");
695 return lock;
696 }
697
698 // Set the initialization lock to null so the object can be GC'ed. Any racing
699 // threads to get this lock will see a null lock and will not lock.
700 // That's okay because they all check for initialized state after getting
701 // the lock and return.
702 void InstanceKlass::fence_and_clear_init_lock() {
703 // make sure previous stores are all done, notably the init_state.
704 OrderAccess::storestore();
705 java_lang_Class::set_init_lock(java_mirror(), NULL);
706 assert(!is_not_initialized(), "class must be initialized now");
707 }
708
709 void InstanceKlass::eager_initialize_impl() {
710 EXCEPTION_MARK;
711 HandleMark hm(THREAD);
712 Handle h_init_lock(THREAD, init_lock());
713 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
714
715 // abort if someone beat us to the initialization
716 if (!is_not_initialized()) return; // note: not equivalent to is_initialized()
717
718 ClassState old_state = init_state();
719 link_class_impl(THREAD);
720 if (HAS_PENDING_EXCEPTION) {
721 CLEAR_PENDING_EXCEPTION;
722 // Abort if linking the class throws an exception.
723
724 // Use a test to avoid redundantly resetting the state if there's
725 // no change. Set_init_state() asserts that state changes make
726 // progress, whereas here we might just be spinning in place.
727 if (old_state != _init_state)
728 set_init_state(old_state);
729 } else {
730 // linking successfull, mark class as initialized
731 set_init_state(fully_initialized);
732 fence_and_clear_init_lock();
733 // trace
734 if (log_is_enabled(Info, class, init)) {
735 ResourceMark rm(THREAD);
736 log_info(class, init)("[Initialized %s without side effects]", external_name());
737 }
738 }
739 }
740
741
742 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
743 // process. The step comments refers to the procedure described in that section.
744 // Note: implementation moved to static method to expose the this pointer.
745 void InstanceKlass::initialize(TRAPS) {
746 if (this->should_be_initialized()) {
747 initialize_impl(CHECK);
748 // Note: at this point the class may be initialized
749 // OR it may be in the state of being initialized
750 // in case of recursive initialization!
751 } else {
752 assert(is_initialized(), "sanity check");
753 }
754 }
755
756
757 bool InstanceKlass::verify_code(TRAPS) {
758 // 1) Verify the bytecodes
759 return Verifier::verify(this, should_verify_class(), THREAD);
760 }
761
762 void InstanceKlass::link_class(TRAPS) {
763 assert(is_loaded(), "must be loaded");
764 if (!is_linked()) {
765 link_class_impl(CHECK);
766 }
767 }
768
769 // Called to verify that a class can link during initialization, without
770 // throwing a VerifyError.
771 bool InstanceKlass::link_class_or_fail(TRAPS) {
772 assert(is_loaded(), "must be loaded");
773 if (!is_linked()) {
774 link_class_impl(CHECK_false);
775 }
776 return is_linked();
777 }
778
779 bool InstanceKlass::link_class_impl(TRAPS) {
780 if (DumpSharedSpaces && is_in_error_state()) {
781 // This is for CDS dumping phase only -- we use the in_error_state to indicate that
782 // the class has failed verification. Throwing the NoClassDefFoundError here is just
783 // a convenient way to stop repeat attempts to verify the same (bad) class.
784 //
785 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
786 // if we are executing Java code. This is not a problem for CDS dumping phase since
787 // it doesn't execute any Java code.
788 ResourceMark rm(THREAD);
789 Exceptions::fthrow(THREAD_AND_LOCATION,
790 vmSymbols::java_lang_NoClassDefFoundError(),
791 "Class %s, or one of its supertypes, failed class initialization",
792 external_name());
793 return false;
794 }
795 // return if already verified
796 if (is_linked()) {
797 return true;
798 }
799
800 // Timing
801 // timer handles recursion
802 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
803 JavaThread* jt = (JavaThread*)THREAD;
804
805 // link super class before linking this class
806 Klass* super_klass = super();
807 if (super_klass != NULL) {
808 if (super_klass->is_interface()) { // check if super class is an interface
809 ResourceMark rm(THREAD);
810 Exceptions::fthrow(
811 THREAD_AND_LOCATION,
812 vmSymbols::java_lang_IncompatibleClassChangeError(),
813 "class %s has interface %s as super class",
814 external_name(),
815 super_klass->external_name()
816 );
817 return false;
818 }
819
820 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
821 ik_super->link_class_impl(CHECK_false);
822 }
823
824 // link all interfaces implemented by this class before linking this class
825 Array<InstanceKlass*>* interfaces = local_interfaces();
826 int num_interfaces = interfaces->length();
827 for (int index = 0; index < num_interfaces; index++) {
828 InstanceKlass* interk = interfaces->at(index);
829 interk->link_class_impl(CHECK_false);
830 }
831
832
833 // If a class declares a method that uses a value class as an argument
834 // type or return value type, this value class must be loaded during the
835 // linking of this class because size and properties of the value class
836 // must be known in order to be able to perform value type optimizations.
837 // The implementation below is an approximation of this rule, the code
838 // iterates over all methods of the current class (including overridden
839 // methods), not only the methods declared by this class. This
840 // approximation makes the code simpler, and doesn't change the semantic
841 // because classes declaring methods overridden by the current class are
842 // linked (and have performed their own pre-loading) before the linking
843 // of the current class.
844 // This is also the moment to detect potential mismatch between the
845 // ValueTypes attribute and the kind of the class effectively loaded.
846
847
848 // Note:
849 // Value class types used for flattenable fields are loaded during
850 // the loading phase (see ClassFileParser::post_process_parsed_stream()).
851 // Value class types used as element types for array creation
852 // are not pre-loaded. Their loading is triggered by either anewarray
853 // or multianewarray bytecodes.
854
855 // Could it be possible to do the following processing only if the
856 // class uses value types?
857 {
858 ResourceMark rm(THREAD);
859 for (int i = 0; i < methods()->length(); i++) {
860 Method* m = methods()->at(i);
861 for (SignatureStream ss(m->signature()); !ss.is_done(); ss.next()) {
862 Symbol* sig = ss.as_symbol(THREAD);
863 if (ss.is_object()) {
864 Symbol* symb = sig;
865 if (ss.is_array()) {
866 int i=0;
867 while (sig->char_at(i) == '[') i++;
868 if (i == sig->utf8_length() - 1 ) continue; // primitive array
869 symb = SymbolTable::lookup(sig->as_C_string() + i + 1,
870 sig->utf8_length() - 3, CHECK_false);
871 }
872 if (ss.type() == T_VALUETYPE) {
873 oop loader = class_loader();
874 oop protection_domain = this->protection_domain();
875 Klass* klass = SystemDictionary::resolve_or_fail(symb,
876 Handle(THREAD, loader), Handle(THREAD, protection_domain), true,
877 CHECK_false);
878 if (symb != sig) {
879 symb->decrement_refcount();
880 }
881 if (klass == NULL) {
882 THROW_(vmSymbols::java_lang_LinkageError(), false);
883 }
884 if (!klass->is_value()) {
885 THROW_(vmSymbols::java_lang_IncompatibleClassChangeError(), false);
886 }
887 }
888 }
889 }
890 }
891 }
892
893 // in case the class is linked in the process of linking its superclasses
894 if (is_linked()) {
895 return true;
896 }
897
898 // trace only the link time for this klass that includes
899 // the verification time
900 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
901 ClassLoader::perf_class_link_selftime(),
902 ClassLoader::perf_classes_linked(),
903 jt->get_thread_stat()->perf_recursion_counts_addr(),
904 jt->get_thread_stat()->perf_timers_addr(),
905 PerfClassTraceTime::CLASS_LINK);
906
907 // verification & rewriting
908 {
909 HandleMark hm(THREAD);
910 Handle h_init_lock(THREAD, init_lock());
911 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
912 // rewritten will have been set if loader constraint error found
913 // on an earlier link attempt
914 // don't verify or rewrite if already rewritten
915 //
916
917 if (!is_linked()) {
918 if (!is_rewritten()) {
919 {
920 bool verify_ok = verify_code(THREAD);
921 if (!verify_ok) {
922 return false;
923 }
924 }
925
926 // Just in case a side-effect of verify linked this class already
927 // (which can sometimes happen since the verifier loads classes
928 // using custom class loaders, which are free to initialize things)
929 if (is_linked()) {
930 return true;
931 }
932
933 // also sets rewritten
934 rewrite_class(CHECK_false);
935 } else if (is_shared()) {
936 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
937 }
938
939 // relocate jsrs and link methods after they are all rewritten
940 link_methods(CHECK_false);
941
942 // Initialize the vtable and interface table after
943 // methods have been rewritten since rewrite may
944 // fabricate new Method*s.
945 // also does loader constraint checking
946 //
947 // initialize_vtable and initialize_itable need to be rerun for
948 // a shared class if the class is not loaded by the NULL classloader.
949 ClassLoaderData * loader_data = class_loader_data();
950 if (!(is_shared() &&
951 loader_data->is_the_null_class_loader_data())) {
952 vtable().initialize_vtable(true, CHECK_false);
953 itable().initialize_itable(true, CHECK_false);
954 }
955 #ifdef ASSERT
956 else {
957 vtable().verify(tty, true);
958 // In case itable verification is ever added.
959 // itable().verify(tty, true);
960 }
961 #endif
962
963 set_init_state(linked);
964 if (JvmtiExport::should_post_class_prepare()) {
965 Thread *thread = THREAD;
966 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
967 JvmtiExport::post_class_prepare((JavaThread *) thread, this);
968 }
969 }
970 }
971 return true;
972 }
973
974 // Rewrite the byte codes of all of the methods of a class.
975 // The rewriter must be called exactly once. Rewriting must happen after
976 // verification but before the first method of the class is executed.
977 void InstanceKlass::rewrite_class(TRAPS) {
978 assert(is_loaded(), "must be loaded");
979 if (is_rewritten()) {
980 assert(is_shared(), "rewriting an unshared class?");
981 return;
982 }
983 Rewriter::rewrite(this, CHECK);
984 set_rewritten();
985 }
986
987 // Now relocate and link method entry points after class is rewritten.
988 // This is outside is_rewritten flag. In case of an exception, it can be
989 // executed more than once.
990 void InstanceKlass::link_methods(TRAPS) {
991 int len = methods()->length();
992 for (int i = len-1; i >= 0; i--) {
993 methodHandle m(THREAD, methods()->at(i));
994
995 // Set up method entry points for compiler and interpreter .
996 m->link_method(m, CHECK);
997 }
998 }
999
1000 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1001 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1002 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1003 for (int i = 0; i < local_interfaces()->length(); ++i) {
1004 InstanceKlass* ik = local_interfaces()->at(i);
1005
1006 // Initialization is depth first search ie. we start with top of the inheritance tree
1007 // has_nonstatic_concrete_methods drives searching superinterfaces since it
1008 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1009 if (ik->has_nonstatic_concrete_methods()) {
1010 ik->initialize_super_interfaces(CHECK);
1011 }
1012
1013 // Only initialize() interfaces that "declare" concrete methods.
1014 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1015 ik->initialize(CHECK);
1016 }
1017 }
1018 }
1019
1020 void InstanceKlass::initialize_impl(TRAPS) {
1021 HandleMark hm(THREAD);
1022
1023 // Make sure klass is linked (verified) before initialization
1024 // A class could already be verified, since it has been reflected upon.
1025 link_class(CHECK);
1026
1027 DTRACE_CLASSINIT_PROBE(required, -1);
1028
1029 bool wait = false;
1030
1031 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
1032 JavaThread* jt = (JavaThread*)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, THREAD, h_init_lock() != NULL);
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.waitUninterruptibly(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 // Step 8
1117 // Initialize classes of flattenable fields
1118 {
1119 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1120 if (fs.is_flattenable()) {
1121 InstanceKlass* field_klass = InstanceKlass::cast(this->get_value_field_klass(fs.index()));
1122 field_klass->initialize(CHECK);
1123 }
1124 }
1125 }
1126
1127
1128 // Look for aot compiled methods for this klass, including class initializer.
1129 AOTLoader::load_for_klass(this, THREAD);
1130
1131 // Step 9
1132 {
1133 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1134 // Timer includes any side effects of class initialization (resolution,
1135 // etc), but not recursive entry into call_class_initializer().
1136 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1137 ClassLoader::perf_class_init_selftime(),
1138 ClassLoader::perf_classes_inited(),
1139 jt->get_thread_stat()->perf_recursion_counts_addr(),
1140 jt->get_thread_stat()->perf_timers_addr(),
1141 PerfClassTraceTime::CLASS_CLINIT);
1142 call_class_initializer(THREAD);
1143 }
1144
1145 // Step 10
1146 if (!HAS_PENDING_EXCEPTION) {
1147 set_initialization_state_and_notify(fully_initialized, CHECK);
1148 {
1149 debug_only(vtable().verify(tty, true);)
1150 }
1151 }
1152 else {
1153 // Step 11 and 12
1154 Handle e(THREAD, PENDING_EXCEPTION);
1155 CLEAR_PENDING_EXCEPTION;
1156 // JVMTI has already reported the pending exception
1157 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1158 JvmtiExport::clear_detected_exception(jt);
1159 {
1160 EXCEPTION_MARK;
1161 set_initialization_state_and_notify(initialization_error, THREAD);
1162 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1163 // JVMTI has already reported the pending exception
1164 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1165 JvmtiExport::clear_detected_exception(jt);
1166 }
1167 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1168 if (e->is_a(SystemDictionary::Error_klass())) {
1169 THROW_OOP(e());
1170 } else {
1171 JavaCallArguments args(e);
1172 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1173 vmSymbols::throwable_void_signature(),
1174 &args);
1175 }
1176 }
1177 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1178 }
1179
1180
1181 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1182 Handle h_init_lock(THREAD, init_lock());
1183 if (h_init_lock() != NULL) {
1184 ObjectLocker ol(h_init_lock, THREAD);
1185 set_init_state(state);
1186 fence_and_clear_init_lock();
1187 ol.notify_all(CHECK);
1188 } else {
1189 assert(h_init_lock() != NULL, "The initialization state should never be set twice");
1190 set_init_state(state);
1191 }
1192 }
1193
1194 Klass* InstanceKlass::implementor() const {
1195 Klass* volatile* k = adr_implementor();
1196 if (k == NULL) {
1197 return NULL;
1198 } else {
1199 // This load races with inserts, and therefore needs acquire.
1200 Klass* kls = OrderAccess::load_acquire(k);
1201 if (kls != NULL && !kls->is_loader_alive()) {
1202 return NULL; // don't return unloaded class
1203 } else {
1204 return kls;
1205 }
1206 }
1207 }
1208
1209
1210 void InstanceKlass::set_implementor(Klass* k) {
1211 assert_lock_strong(Compile_lock);
1212 assert(is_interface(), "not interface");
1213 Klass* volatile* addr = adr_implementor();
1214 assert(addr != NULL, "null addr");
1215 if (addr != NULL) {
1216 OrderAccess::release_store(addr, k);
1217 }
1218 }
1219
1220 int InstanceKlass::nof_implementors() const {
1221 Klass* k = implementor();
1222 if (k == NULL) {
1223 return 0;
1224 } else if (k != this) {
1225 return 1;
1226 } else {
1227 return 2;
1228 }
1229 }
1230
1231 // The embedded _implementor field can only record one implementor.
1232 // When there are more than one implementors, the _implementor field
1233 // is set to the interface Klass* itself. Following are the possible
1234 // values for the _implementor field:
1235 // NULL - no implementor
1236 // implementor Klass* - one implementor
1237 // self - more than one implementor
1238 //
1239 // The _implementor field only exists for interfaces.
1240 void InstanceKlass::add_implementor(Klass* k) {
1241 assert_lock_strong(Compile_lock);
1242 assert(is_interface(), "not interface");
1243 // Filter out my subinterfaces.
1244 // (Note: Interfaces are never on the subklass list.)
1245 if (InstanceKlass::cast(k)->is_interface()) return;
1246
1247 // Filter out subclasses whose supers already implement me.
1248 // (Note: CHA must walk subclasses of direct implementors
1249 // in order to locate indirect implementors.)
1250 Klass* sk = k->super();
1251 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
1252 // We only need to check one immediate superclass, since the
1253 // implements_interface query looks at transitive_interfaces.
1254 // Any supers of the super have the same (or fewer) transitive_interfaces.
1255 return;
1256
1257 Klass* ik = implementor();
1258 if (ik == NULL) {
1259 set_implementor(k);
1260 } else if (ik != this) {
1261 // There is already an implementor. Use itself as an indicator of
1262 // more than one implementors.
1263 set_implementor(this);
1264 }
1265
1266 // The implementor also implements the transitive_interfaces
1267 for (int index = 0; index < local_interfaces()->length(); index++) {
1268 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
1269 }
1270 }
1271
1272 void InstanceKlass::init_implementor() {
1273 if (is_interface()) {
1274 set_implementor(NULL);
1275 }
1276 }
1277
1278
1279 void InstanceKlass::process_interfaces(Thread *thread) {
1280 // link this class into the implementors list of every interface it implements
1281 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1282 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1283 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
1284 assert(interf->is_interface(), "expected interface");
1285 interf->add_implementor(this);
1286 }
1287 }
1288
1289 bool InstanceKlass::can_be_primary_super_slow() const {
1290 if (is_interface())
1291 return false;
1292 else
1293 return Klass::can_be_primary_super_slow();
1294 }
1295
1296 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1297 Array<InstanceKlass*>* transitive_interfaces) {
1298 // The secondaries are the implemented interfaces.
1299 Array<InstanceKlass*>* interfaces = transitive_interfaces;
1300 int num_secondaries = num_extra_slots + interfaces->length();
1301 if (num_secondaries == 0) {
1302 // Must share this for correct bootstrapping!
1303 set_secondary_supers(Universe::the_empty_klass_array());
1304 return NULL;
1305 } else if (num_extra_slots == 0) {
1306 // The secondary super list is exactly the same as the transitive interfaces, so
1307 // let's use it instead of making a copy.
1308 // Redefine classes has to be careful not to delete this!
1309 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1310 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1311 set_secondary_supers((Array<Klass*>*)(address)interfaces);
1312 return NULL;
1313 } else {
1314 // Copy transitive interfaces to a temporary growable array to be constructed
1315 // into the secondary super list with extra slots.
1316 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1317 for (int i = 0; i < interfaces->length(); i++) {
1318 secondaries->push(interfaces->at(i));
1319 }
1320 return secondaries;
1321 }
1322 }
1323
1324 bool InstanceKlass::implements_interface(Klass* k) const {
1325 if (this == k) return true;
1326 assert(k->is_interface(), "should be an interface class");
1327 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1328 if (transitive_interfaces()->at(i) == k) {
1329 return true;
1330 }
1331 }
1332 return false;
1333 }
1334
1335 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1336 // Verify direct super interface
1337 if (this == k) return true;
1338 assert(k->is_interface(), "should be an interface class");
1339 for (int i = 0; i < local_interfaces()->length(); i++) {
1340 if (local_interfaces()->at(i) == k) {
1341 return true;
1342 }
1343 }
1344 return false;
1345 }
1346
1347 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1348 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1349 int size = objArrayOopDesc::object_size(length);
1350 Klass* ak = array_klass(n, CHECK_NULL);
1351 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1352 /* do_zero */ true, CHECK_NULL);
1353 return o;
1354 }
1355
1356 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1357 if (TraceFinalizerRegistration) {
1358 tty->print("Registered ");
1359 i->print_value_on(tty);
1360 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1361 }
1362 instanceHandle h_i(THREAD, i);
1363 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1364 JavaValue result(T_VOID);
1365 JavaCallArguments args(h_i);
1366 methodHandle mh (THREAD, Universe::finalizer_register_method());
1367 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1368 return h_i();
1369 }
1370
1371 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1372 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1373 int size = size_helper(); // Query before forming handle.
1374
1375 instanceOop i;
1376
1377 i = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1378 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1379 i = register_finalizer(i, CHECK_NULL);
1380 }
1381 return i;
1382 }
1383
1384 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1385 return instanceHandle(THREAD, allocate_instance(THREAD));
1386 }
1387
1388 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1389 if (is_interface() || is_abstract()) {
1390 ResourceMark rm(THREAD);
1391 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1392 : vmSymbols::java_lang_InstantiationException(), external_name());
1393 }
1394 if (this == SystemDictionary::Class_klass()) {
1395 ResourceMark rm(THREAD);
1396 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1397 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1398 }
1399 }
1400
1401 Klass* InstanceKlass::array_klass_impl(ArrayStorageProperties storage_props, bool or_null, int n, TRAPS) {
1402 assert(!storage_props.is_flattened(), "Can't be flattened");
1403 // Need load-acquire for lock-free read
1404 if (array_klasses_acquire() == NULL) {
1405 if (or_null) return NULL;
1406
1407 ResourceMark rm;
1408 JavaThread *jt = (JavaThread *)THREAD;
1409 {
1410 // Atomic creation of array_klasses
1411 MutexLocker ma(MultiArray_lock, THREAD);
1412
1413 // Check if update has already taken place
1414 if (array_klasses() == NULL) {
1415 Klass* k = ObjArrayKlass::allocate_objArray_klass(storage_props, 1, this, CHECK_NULL);
1416 // use 'release' to pair with lock-free load
1417 release_set_array_klasses(k);
1418 }
1419 }
1420 }
1421 // _this will always be set at this point
1422 ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1423 if (or_null) {
1424 return oak->array_klass_or_null(storage_props, n);
1425 }
1426 return oak->array_klass(storage_props, n, THREAD);
1427 }
1428
1429 Klass* InstanceKlass::array_klass_impl(ArrayStorageProperties storage_props, bool or_null, TRAPS) {
1430 return array_klass_impl(storage_props, or_null, 1, THREAD);
1431 }
1432
1433 static int call_class_initializer_counter = 0; // for debugging
1434
1435 Method* InstanceKlass::class_initializer() const {
1436 Method* clinit = find_method(
1437 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1438 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1439 return clinit;
1440 }
1441 return NULL;
1442 }
1443
1444 void InstanceKlass::call_class_initializer(TRAPS) {
1445 if (ReplayCompiles &&
1446 (ReplaySuppressInitializers == 1 ||
1447 (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1448 // Hide the existence of the initializer for the purpose of replaying the compile
1449 return;
1450 }
1451
1452 methodHandle h_method(THREAD, class_initializer());
1453 assert(!is_initialized(), "we cannot initialize twice");
1454 LogTarget(Info, class, init) lt;
1455 if (lt.is_enabled()) {
1456 ResourceMark rm;
1457 LogStream ls(lt);
1458 ls.print("%d Initializing ", call_class_initializer_counter++);
1459 name()->print_value_on(&ls);
1460 ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1461 }
1462 if (h_method() != NULL) {
1463 JavaCallArguments args; // No arguments
1464 JavaValue result(T_VOID);
1465 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1466 }
1467 }
1468
1469
1470 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1471 InterpreterOopMap* entry_for) {
1472 // Lazily create the _oop_map_cache at first request
1473 // Lock-free access requires load_acquire.
1474 OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache);
1475 if (oop_map_cache == NULL) {
1476 MutexLockerEx x(OopMapCacheAlloc_lock, Mutex::_no_safepoint_check_flag);
1477 // Check if _oop_map_cache was allocated while we were waiting for this lock
1478 if ((oop_map_cache = _oop_map_cache) == NULL) {
1479 oop_map_cache = new OopMapCache();
1480 // Ensure _oop_map_cache is stable, since it is examined without a lock
1481 OrderAccess::release_store(&_oop_map_cache, oop_map_cache);
1482 }
1483 }
1484 // _oop_map_cache is constant after init; lookup below does its own locking.
1485 oop_map_cache->lookup(method, bci, entry_for);
1486 }
1487
1488
1489 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1490 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1491 Symbol* f_name = fs.name();
1492 Symbol* f_sig = fs.signature();
1493 if (f_name == name && f_sig == sig) {
1494 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1495 return true;
1496 }
1497 }
1498 return false;
1499 }
1500
1501
1502 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1503 const int n = local_interfaces()->length();
1504 for (int i = 0; i < n; i++) {
1505 Klass* intf1 = local_interfaces()->at(i);
1506 assert(intf1->is_interface(), "just checking type");
1507 // search for field in current interface
1508 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1509 assert(fd->is_static(), "interface field must be static");
1510 return intf1;
1511 }
1512 // search for field in direct superinterfaces
1513 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1514 if (intf2 != NULL) return intf2;
1515 }
1516 // otherwise field lookup fails
1517 return NULL;
1518 }
1519
1520
1521 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1522 // search order according to newest JVM spec (5.4.3.2, p.167).
1523 // 1) search for field in current klass
1524 if (find_local_field(name, sig, fd)) {
1525 return const_cast<InstanceKlass*>(this);
1526 }
1527 // 2) search for field recursively in direct superinterfaces
1528 { Klass* intf = find_interface_field(name, sig, fd);
1529 if (intf != NULL) return intf;
1530 }
1531 // 3) apply field lookup recursively if superclass exists
1532 { Klass* supr = super();
1533 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1534 }
1535 // 4) otherwise field lookup fails
1536 return NULL;
1537 }
1538
1539
1540 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1541 // search order according to newest JVM spec (5.4.3.2, p.167).
1542 // 1) search for field in current klass
1543 if (find_local_field(name, sig, fd)) {
1544 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1545 }
1546 // 2) search for field recursively in direct superinterfaces
1547 if (is_static) {
1548 Klass* intf = find_interface_field(name, sig, fd);
1549 if (intf != NULL) return intf;
1550 }
1551 // 3) apply field lookup recursively if superclass exists
1552 { Klass* supr = super();
1553 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1554 }
1555 // 4) otherwise field lookup fails
1556 return NULL;
1557 }
1558
1559
1560 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1561 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1562 if (fs.offset() == offset) {
1563 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1564 if (fd->is_static() == is_static) return true;
1565 }
1566 }
1567 return false;
1568 }
1569
1570
1571 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1572 Klass* klass = const_cast<InstanceKlass*>(this);
1573 while (klass != NULL) {
1574 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1575 return true;
1576 }
1577 klass = klass->super();
1578 }
1579 return false;
1580 }
1581
1582
1583 void InstanceKlass::methods_do(void f(Method* method)) {
1584 // Methods aren't stable until they are loaded. This can be read outside
1585 // a lock through the ClassLoaderData for profiling
1586 if (!is_loaded()) {
1587 return;
1588 }
1589
1590 int len = methods()->length();
1591 for (int index = 0; index < len; index++) {
1592 Method* m = methods()->at(index);
1593 assert(m->is_method(), "must be method");
1594 f(m);
1595 }
1596 }
1597
1598
1599 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1600 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1601 if (fs.access_flags().is_static()) {
1602 fieldDescriptor& fd = fs.field_descriptor();
1603 cl->do_field(&fd);
1604 }
1605 }
1606 }
1607
1608
1609 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1610 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1611 if (fs.access_flags().is_static()) {
1612 fieldDescriptor& fd = fs.field_descriptor();
1613 f(&fd, mirror, CHECK);
1614 }
1615 }
1616 }
1617
1618
1619 static int compare_fields_by_offset(int* a, int* b) {
1620 return a[0] - b[0];
1621 }
1622
1623 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1624 InstanceKlass* super = superklass();
1625 if (super != NULL) {
1626 super->do_nonstatic_fields(cl);
1627 }
1628 fieldDescriptor fd;
1629 int length = java_fields_count();
1630 // In DebugInfo nonstatic fields are sorted by offset.
1631 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1632 int j = 0;
1633 for (int i = 0; i < length; i += 1) {
1634 fd.reinitialize(this, i);
1635 if (!fd.is_static()) {
1636 fields_sorted[j + 0] = fd.offset();
1637 fields_sorted[j + 1] = i;
1638 j += 2;
1639 }
1640 }
1641 if (j > 0) {
1642 length = j;
1643 // _sort_Fn is defined in growableArray.hpp.
1644 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1645 for (int i = 0; i < length; i += 2) {
1646 fd.reinitialize(this, fields_sorted[i + 1]);
1647 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1648 cl->do_field(&fd);
1649 }
1650 }
1651 FREE_C_HEAP_ARRAY(int, fields_sorted);
1652 }
1653
1654
1655 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1656 if (array_klasses() != NULL)
1657 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1658 }
1659
1660 #ifdef ASSERT
1661 static int linear_search(const Array<Method*>* methods,
1662 const Symbol* name,
1663 const Symbol* signature) {
1664 const int len = methods->length();
1665 for (int index = 0; index < len; index++) {
1666 const Method* const m = methods->at(index);
1667 assert(m->is_method(), "must be method");
1668 if (m->signature() == signature && m->name() == name) {
1669 return index;
1670 }
1671 }
1672 return -1;
1673 }
1674 #endif
1675
1676 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1677 int len = methods->length();
1678 // methods are sorted, so do binary search
1679 int l = 0;
1680 int h = len - 1;
1681 while (l <= h) {
1682 int mid = (l + h) >> 1;
1683 Method* m = methods->at(mid);
1684 assert(m->is_method(), "must be method");
1685 int res = m->name()->fast_compare(name);
1686 if (res == 0) {
1687 return mid;
1688 } else if (res < 0) {
1689 l = mid + 1;
1690 } else {
1691 h = mid - 1;
1692 }
1693 }
1694 return -1;
1695 }
1696
1697 // find_method looks up the name/signature in the local methods array
1698 Method* InstanceKlass::find_method(const Symbol* name,
1699 const Symbol* signature) const {
1700 return find_method_impl(name, signature, find_overpass, find_static, find_private);
1701 }
1702
1703 Method* InstanceKlass::find_method_impl(const Symbol* name,
1704 const Symbol* signature,
1705 OverpassLookupMode overpass_mode,
1706 StaticLookupMode static_mode,
1707 PrivateLookupMode private_mode) const {
1708 return InstanceKlass::find_method_impl(methods(),
1709 name,
1710 signature,
1711 overpass_mode,
1712 static_mode,
1713 private_mode);
1714 }
1715
1716 // find_instance_method looks up the name/signature in the local methods array
1717 // and skips over static methods
1718 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1719 const Symbol* name,
1720 const Symbol* signature,
1721 PrivateLookupMode private_mode) {
1722 Method* const meth = InstanceKlass::find_method_impl(methods,
1723 name,
1724 signature,
1725 find_overpass,
1726 skip_static,
1727 private_mode);
1728 assert(((meth == NULL) || !meth->is_static()),
1729 "find_instance_method should have skipped statics");
1730 return meth;
1731 }
1732
1733 // find_instance_method looks up the name/signature in the local methods array
1734 // and skips over static methods
1735 Method* InstanceKlass::find_instance_method(const Symbol* name,
1736 const Symbol* signature,
1737 PrivateLookupMode private_mode) const {
1738 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1739 }
1740
1741 // Find looks up the name/signature in the local methods array
1742 // and filters on the overpass, static and private flags
1743 // This returns the first one found
1744 // note that the local methods array can have up to one overpass, one static
1745 // and one instance (private or not) with the same name/signature
1746 Method* InstanceKlass::find_local_method(const Symbol* name,
1747 const Symbol* signature,
1748 OverpassLookupMode overpass_mode,
1749 StaticLookupMode static_mode,
1750 PrivateLookupMode private_mode) const {
1751 return InstanceKlass::find_method_impl(methods(),
1752 name,
1753 signature,
1754 overpass_mode,
1755 static_mode,
1756 private_mode);
1757 }
1758
1759 // Find looks up the name/signature in the local methods array
1760 // and filters on the overpass, static and private flags
1761 // This returns the first one found
1762 // note that the local methods array can have up to one overpass, one static
1763 // and one instance (private or not) with the same name/signature
1764 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1765 const Symbol* name,
1766 const Symbol* signature,
1767 OverpassLookupMode overpass_mode,
1768 StaticLookupMode static_mode,
1769 PrivateLookupMode private_mode) {
1770 return InstanceKlass::find_method_impl(methods,
1771 name,
1772 signature,
1773 overpass_mode,
1774 static_mode,
1775 private_mode);
1776 }
1777
1778 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1779 const Symbol* name,
1780 const Symbol* signature) {
1781 return InstanceKlass::find_method_impl(methods,
1782 name,
1783 signature,
1784 find_overpass,
1785 find_static,
1786 find_private);
1787 }
1788
1789 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1790 const Symbol* name,
1791 const Symbol* signature,
1792 OverpassLookupMode overpass_mode,
1793 StaticLookupMode static_mode,
1794 PrivateLookupMode private_mode) {
1795 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1796 return hit >= 0 ? methods->at(hit): NULL;
1797 }
1798
1799 // true if method matches signature and conforms to skipping_X conditions.
1800 static bool method_matches(const Method* m,
1801 const Symbol* signature,
1802 bool skipping_overpass,
1803 bool skipping_static,
1804 bool skipping_private) {
1805 return ((m->signature() == signature) &&
1806 (!skipping_overpass || !m->is_overpass()) &&
1807 (!skipping_static || !m->is_static()) &&
1808 (!skipping_private || !m->is_private()));
1809 }
1810
1811 // Used directly for default_methods to find the index into the
1812 // default_vtable_indices, and indirectly by find_method
1813 // find_method_index looks in the local methods array to return the index
1814 // of the matching name/signature. If, overpass methods are being ignored,
1815 // the search continues to find a potential non-overpass match. This capability
1816 // is important during method resolution to prefer a static method, for example,
1817 // over an overpass method.
1818 // There is the possibility in any _method's array to have the same name/signature
1819 // for a static method, an overpass method and a local instance method
1820 // To correctly catch a given method, the search criteria may need
1821 // to explicitly skip the other two. For local instance methods, it
1822 // is often necessary to skip private methods
1823 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1824 const Symbol* name,
1825 const Symbol* signature,
1826 OverpassLookupMode overpass_mode,
1827 StaticLookupMode static_mode,
1828 PrivateLookupMode private_mode) {
1829 const bool skipping_overpass = (overpass_mode == skip_overpass);
1830 const bool skipping_static = (static_mode == skip_static);
1831 const bool skipping_private = (private_mode == skip_private);
1832 const int hit = binary_search(methods, name);
1833 if (hit != -1) {
1834 const Method* const m = methods->at(hit);
1835
1836 // Do linear search to find matching signature. First, quick check
1837 // for common case, ignoring overpasses if requested.
1838 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1839 return hit;
1840 }
1841
1842 // search downwards through overloaded methods
1843 int i;
1844 for (i = hit - 1; i >= 0; --i) {
1845 const Method* const m = methods->at(i);
1846 assert(m->is_method(), "must be method");
1847 if (m->name() != name) {
1848 break;
1849 }
1850 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1851 return i;
1852 }
1853 }
1854 // search upwards
1855 for (i = hit + 1; i < methods->length(); ++i) {
1856 const Method* const m = methods->at(i);
1857 assert(m->is_method(), "must be method");
1858 if (m->name() != name) {
1859 break;
1860 }
1861 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1862 return i;
1863 }
1864 }
1865 // not found
1866 #ifdef ASSERT
1867 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1868 linear_search(methods, name, signature);
1869 assert(-1 == index, "binary search should have found entry %d", index);
1870 #endif
1871 }
1872 return -1;
1873 }
1874
1875 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1876 return find_method_by_name(methods(), name, end);
1877 }
1878
1879 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1880 const Symbol* name,
1881 int* end_ptr) {
1882 assert(end_ptr != NULL, "just checking");
1883 int start = binary_search(methods, name);
1884 int end = start + 1;
1885 if (start != -1) {
1886 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1887 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1888 *end_ptr = end;
1889 return start;
1890 }
1891 return -1;
1892 }
1893
1894 // uncached_lookup_method searches both the local class methods array and all
1895 // superclasses methods arrays, skipping any overpass methods in superclasses,
1896 // and possibly skipping private methods.
1897 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1898 const Symbol* signature,
1899 OverpassLookupMode overpass_mode,
1900 PrivateLookupMode private_mode) const {
1901 OverpassLookupMode overpass_local_mode = overpass_mode;
1902 const Klass* klass = this;
1903 while (klass != NULL) {
1904 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1905 signature,
1906 overpass_local_mode,
1907 find_static,
1908 private_mode);
1909 if (method != NULL) {
1910 return method;
1911 }
1912 klass = klass->super();
1913 overpass_local_mode = skip_overpass; // Always ignore overpass methods in superclasses
1914 }
1915 return NULL;
1916 }
1917
1918 #ifdef ASSERT
1919 // search through class hierarchy and return true if this class or
1920 // one of the superclasses was redefined
1921 bool InstanceKlass::has_redefined_this_or_super() const {
1922 const Klass* klass = this;
1923 while (klass != NULL) {
1924 if (InstanceKlass::cast(klass)->has_been_redefined()) {
1925 return true;
1926 }
1927 klass = klass->super();
1928 }
1929 return false;
1930 }
1931 #endif
1932
1933 // lookup a method in the default methods list then in all transitive interfaces
1934 // Do NOT return private or static methods
1935 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1936 Symbol* signature) const {
1937 Method* m = NULL;
1938 if (default_methods() != NULL) {
1939 m = find_method(default_methods(), name, signature);
1940 }
1941 // Look up interfaces
1942 if (m == NULL) {
1943 m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1944 }
1945 return m;
1946 }
1947
1948 // lookup a method in all the interfaces that this class implements
1949 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1950 // They should only be found in the initial InterfaceMethodRef
1951 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1952 Symbol* signature,
1953 DefaultsLookupMode defaults_mode) const {
1954 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1955 int num_ifs = all_ifs->length();
1956 InstanceKlass *ik = NULL;
1957 for (int i = 0; i < num_ifs; i++) {
1958 ik = all_ifs->at(i);
1959 Method* m = ik->lookup_method(name, signature);
1960 if (m != NULL && m->is_public() && !m->is_static() &&
1961 ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1962 return m;
1963 }
1964 }
1965 return NULL;
1966 }
1967
1968 /* jni_id_for_impl for jfieldIds only */
1969 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1970 MutexLocker ml(JfieldIdCreation_lock);
1971 // Retry lookup after we got the lock
1972 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1973 if (probe == NULL) {
1974 // Slow case, allocate new static field identifier
1975 probe = new JNIid(this, offset, jni_ids());
1976 set_jni_ids(probe);
1977 }
1978 return probe;
1979 }
1980
1981
1982 /* jni_id_for for jfieldIds only */
1983 JNIid* InstanceKlass::jni_id_for(int offset) {
1984 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1985 if (probe == NULL) {
1986 probe = jni_id_for_impl(offset);
1987 }
1988 return probe;
1989 }
1990
1991 u2 InstanceKlass::enclosing_method_data(int offset) const {
1992 const Array<jushort>* const inner_class_list = inner_classes();
1993 if (inner_class_list == NULL) {
1994 return 0;
1995 }
1996 const int length = inner_class_list->length();
1997 if (length % inner_class_next_offset == 0) {
1998 return 0;
1999 }
2000 const int index = length - enclosing_method_attribute_size;
2001 assert(offset < enclosing_method_attribute_size, "invalid offset");
2002 return inner_class_list->at(index + offset);
2003 }
2004
2005 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2006 u2 method_index) {
2007 Array<jushort>* inner_class_list = inner_classes();
2008 assert (inner_class_list != NULL, "_inner_classes list is not set up");
2009 int length = inner_class_list->length();
2010 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2011 int index = length - enclosing_method_attribute_size;
2012 inner_class_list->at_put(
2013 index + enclosing_method_class_index_offset, class_index);
2014 inner_class_list->at_put(
2015 index + enclosing_method_method_index_offset, method_index);
2016 }
2017 }
2018
2019 // Lookup or create a jmethodID.
2020 // This code is called by the VMThread and JavaThreads so the
2021 // locking has to be done very carefully to avoid deadlocks
2022 // and/or other cache consistency problems.
2023 //
2024 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2025 size_t idnum = (size_t)method_h->method_idnum();
2026 jmethodID* jmeths = methods_jmethod_ids_acquire();
2027 size_t length = 0;
2028 jmethodID id = NULL;
2029
2030 // We use a double-check locking idiom here because this cache is
2031 // performance sensitive. In the normal system, this cache only
2032 // transitions from NULL to non-NULL which is safe because we use
2033 // release_set_methods_jmethod_ids() to advertise the new cache.
2034 // A partially constructed cache should never be seen by a racing
2035 // thread. We also use release_store() to save a new jmethodID
2036 // in the cache so a partially constructed jmethodID should never be
2037 // seen either. Cache reads of existing jmethodIDs proceed without a
2038 // lock, but cache writes of a new jmethodID requires uniqueness and
2039 // creation of the cache itself requires no leaks so a lock is
2040 // generally acquired in those two cases.
2041 //
2042 // If the RedefineClasses() API has been used, then this cache can
2043 // grow and we'll have transitions from non-NULL to bigger non-NULL.
2044 // Cache creation requires no leaks and we require safety between all
2045 // cache accesses and freeing of the old cache so a lock is generally
2046 // acquired when the RedefineClasses() API has been used.
2047
2048 if (jmeths != NULL) {
2049 // the cache already exists
2050 if (!idnum_can_increment()) {
2051 // the cache can't grow so we can just get the current values
2052 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2053 } else {
2054 // cache can grow so we have to be more careful
2055 if (Threads::number_of_threads() == 0 ||
2056 SafepointSynchronize::is_at_safepoint()) {
2057 // we're single threaded or at a safepoint - no locking needed
2058 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2059 } else {
2060 MutexLocker ml(JmethodIdCreation_lock);
2061 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2062 }
2063 }
2064 }
2065 // implied else:
2066 // we need to allocate a cache so default length and id values are good
2067
2068 if (jmeths == NULL || // no cache yet
2069 length <= idnum || // cache is too short
2070 id == NULL) { // cache doesn't contain entry
2071
2072 // This function can be called by the VMThread so we have to do all
2073 // things that might block on a safepoint before grabbing the lock.
2074 // Otherwise, we can deadlock with the VMThread or have a cache
2075 // consistency issue. These vars keep track of what we might have
2076 // to free after the lock is dropped.
2077 jmethodID to_dealloc_id = NULL;
2078 jmethodID* to_dealloc_jmeths = NULL;
2079
2080 // may not allocate new_jmeths or use it if we allocate it
2081 jmethodID* new_jmeths = NULL;
2082 if (length <= idnum) {
2083 // allocate a new cache that might be used
2084 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
2085 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
2086 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
2087 // cache size is stored in element[0], other elements offset by one
2088 new_jmeths[0] = (jmethodID)size;
2089 }
2090
2091 // allocate a new jmethodID that might be used
2092 jmethodID new_id = NULL;
2093 if (method_h->is_old() && !method_h->is_obsolete()) {
2094 // The method passed in is old (but not obsolete), we need to use the current version
2095 Method* current_method = method_with_idnum((int)idnum);
2096 assert(current_method != NULL, "old and but not obsolete, so should exist");
2097 new_id = Method::make_jmethod_id(class_loader_data(), current_method);
2098 } else {
2099 // It is the current version of the method or an obsolete method,
2100 // use the version passed in
2101 new_id = Method::make_jmethod_id(class_loader_data(), method_h());
2102 }
2103
2104 if (Threads::number_of_threads() == 0 ||
2105 SafepointSynchronize::is_at_safepoint()) {
2106 // we're single threaded or at a safepoint - no locking needed
2107 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2108 &to_dealloc_id, &to_dealloc_jmeths);
2109 } else {
2110 MutexLocker ml(JmethodIdCreation_lock);
2111 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2112 &to_dealloc_id, &to_dealloc_jmeths);
2113 }
2114
2115 // The lock has been dropped so we can free resources.
2116 // Free up either the old cache or the new cache if we allocated one.
2117 if (to_dealloc_jmeths != NULL) {
2118 FreeHeap(to_dealloc_jmeths);
2119 }
2120 // free up the new ID since it wasn't needed
2121 if (to_dealloc_id != NULL) {
2122 Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
2123 }
2124 }
2125 return id;
2126 }
2127
2128 // Figure out how many jmethodIDs haven't been allocated, and make
2129 // sure space for them is pre-allocated. This makes getting all
2130 // method ids much, much faster with classes with more than 8
2131 // methods, and has a *substantial* effect on performance with jvmti
2132 // code that loads all jmethodIDs for all classes.
2133 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2134 int new_jmeths = 0;
2135 int length = methods()->length();
2136 for (int index = start_offset; index < length; index++) {
2137 Method* m = methods()->at(index);
2138 jmethodID id = m->find_jmethod_id_or_null();
2139 if (id == NULL) {
2140 new_jmeths++;
2141 }
2142 }
2143 if (new_jmeths != 0) {
2144 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2145 }
2146 }
2147
2148 // Common code to fetch the jmethodID from the cache or update the
2149 // cache with the new jmethodID. This function should never do anything
2150 // that causes the caller to go to a safepoint or we can deadlock with
2151 // the VMThread or have cache consistency issues.
2152 //
2153 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
2154 size_t idnum, jmethodID new_id,
2155 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
2156 jmethodID** to_dealloc_jmeths_p) {
2157 assert(new_id != NULL, "sanity check");
2158 assert(to_dealloc_id_p != NULL, "sanity check");
2159 assert(to_dealloc_jmeths_p != NULL, "sanity check");
2160 assert(Threads::number_of_threads() == 0 ||
2161 SafepointSynchronize::is_at_safepoint() ||
2162 JmethodIdCreation_lock->owned_by_self(), "sanity check");
2163
2164 // reacquire the cache - we are locked, single threaded or at a safepoint
2165 jmethodID* jmeths = methods_jmethod_ids_acquire();
2166 jmethodID id = NULL;
2167 size_t length = 0;
2168
2169 if (jmeths == NULL || // no cache yet
2170 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
2171 if (jmeths != NULL) {
2172 // copy any existing entries from the old cache
2173 for (size_t index = 0; index < length; index++) {
2174 new_jmeths[index+1] = jmeths[index+1];
2175 }
2176 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
2177 }
2178 release_set_methods_jmethod_ids(jmeths = new_jmeths);
2179 } else {
2180 // fetch jmethodID (if any) from the existing cache
2181 id = jmeths[idnum+1];
2182 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
2183 }
2184 if (id == NULL) {
2185 // No matching jmethodID in the existing cache or we have a new
2186 // cache or we just grew the cache. This cache write is done here
2187 // by the first thread to win the foot race because a jmethodID
2188 // needs to be unique once it is generally available.
2189 id = new_id;
2190
2191 // The jmethodID cache can be read while unlocked so we have to
2192 // make sure the new jmethodID is complete before installing it
2193 // in the cache.
2194 OrderAccess::release_store(&jmeths[idnum+1], id);
2195 } else {
2196 *to_dealloc_id_p = new_id; // save new id for later delete
2197 }
2198 return id;
2199 }
2200
2201
2202 // Common code to get the jmethodID cache length and the jmethodID
2203 // value at index idnum if there is one.
2204 //
2205 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
2206 size_t idnum, size_t *length_p, jmethodID* id_p) {
2207 assert(cache != NULL, "sanity check");
2208 assert(length_p != NULL, "sanity check");
2209 assert(id_p != NULL, "sanity check");
2210
2211 // cache size is stored in element[0], other elements offset by one
2212 *length_p = (size_t)cache[0];
2213 if (*length_p <= idnum) { // cache is too short
2214 *id_p = NULL;
2215 } else {
2216 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
2217 }
2218 }
2219
2220
2221 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
2222 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2223 size_t idnum = (size_t)method->method_idnum();
2224 jmethodID* jmeths = methods_jmethod_ids_acquire();
2225 size_t length; // length assigned as debugging crumb
2226 jmethodID id = NULL;
2227 if (jmeths != NULL && // If there is a cache
2228 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
2229 id = jmeths[idnum+1]; // Look up the id (may be NULL)
2230 }
2231 return id;
2232 }
2233
2234 inline DependencyContext InstanceKlass::dependencies() {
2235 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2236 return dep_context;
2237 }
2238
2239 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
2240 return dependencies().mark_dependent_nmethods(changes);
2241 }
2242
2243 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2244 dependencies().add_dependent_nmethod(nm);
2245 }
2246
2247 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
2248 dependencies().remove_dependent_nmethod(nm);
2249 }
2250
2251 void InstanceKlass::clean_dependency_context() {
2252 dependencies().clean_unloading_dependents();
2253 }
2254
2255 #ifndef PRODUCT
2256 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2257 dependencies().print_dependent_nmethods(verbose);
2258 }
2259
2260 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2261 return dependencies().is_dependent_nmethod(nm);
2262 }
2263 #endif //PRODUCT
2264
2265 void InstanceKlass::clean_weak_instanceklass_links() {
2266 clean_implementors_list();
2267 clean_method_data();
2268 }
2269
2270 void InstanceKlass::clean_implementors_list() {
2271 assert(is_loader_alive(), "this klass should be live");
2272 if (is_interface()) {
2273 assert (ClassUnloading, "only called for ClassUnloading");
2274 for (;;) {
2275 // Use load_acquire due to competing with inserts
2276 Klass* impl = OrderAccess::load_acquire(adr_implementor());
2277 if (impl != NULL && !impl->is_loader_alive()) {
2278 // NULL this field, might be an unloaded klass or NULL
2279 Klass* volatile* klass = adr_implementor();
2280 if (Atomic::cmpxchg((Klass*)NULL, klass, impl) == impl) {
2281 // Successfully unlinking implementor.
2282 if (log_is_enabled(Trace, class, unload)) {
2283 ResourceMark rm;
2284 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2285 }
2286 return;
2287 }
2288 } else {
2289 return;
2290 }
2291 }
2292 }
2293 }
2294
2295 void InstanceKlass::clean_method_data() {
2296 for (int m = 0; m < methods()->length(); m++) {
2297 MethodData* mdo = methods()->at(m)->method_data();
2298 if (mdo != NULL) {
2299 MutexLockerEx ml(SafepointSynchronize::is_at_safepoint() ? NULL : mdo->extra_data_lock());
2300 mdo->clean_method_data(/*always_clean*/false);
2301 }
2302 }
2303 }
2304
2305 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
2306 if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
2307 ResourceMark rm;
2308 log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
2309 return false;
2310 }
2311
2312 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
2313 if (local_interfaces != NULL) {
2314 int length = local_interfaces->length();
2315 for (int i = 0; i < length; i++) {
2316 InstanceKlass* intf = local_interfaces->at(i);
2317 if (!intf->has_passed_fingerprint_check()) {
2318 ResourceMark rm;
2319 log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
2320 return false;
2321 }
2322 }
2323 }
2324
2325 return true;
2326 }
2327
2328 bool InstanceKlass::should_store_fingerprint(bool is_unsafe_anonymous) {
2329 #if INCLUDE_AOT
2330 // We store the fingerprint into the InstanceKlass only in the following 2 cases:
2331 if (CalculateClassFingerprint) {
2332 // (1) We are running AOT to generate a shared library.
2333 return true;
2334 }
2335 if (DumpSharedSpaces) {
2336 // (2) We are running -Xshare:dump to create a shared archive
2337 return true;
2338 }
2339 if (UseAOT && is_unsafe_anonymous) {
2340 // (3) We are using AOT code from a shared library and see an unsafe anonymous class
2341 return true;
2342 }
2343 #endif
2344
2345 // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
2346 // but do not store the 64-bit fingerprint to save space.
2347 return false;
2348 }
2349
2350 bool InstanceKlass::has_stored_fingerprint() const {
2351 #if INCLUDE_AOT
2352 return should_store_fingerprint() || is_shared();
2353 #else
2354 return false;
2355 #endif
2356 }
2357
2358 uint64_t InstanceKlass::get_stored_fingerprint() const {
2359 address adr = adr_fingerprint();
2360 if (adr != NULL) {
2361 return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
2362 }
2363 return 0;
2364 }
2365
2366 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
2367 address adr = adr_fingerprint();
2368 if (adr != NULL) {
2369 Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2370
2371 ResourceMark rm;
2372 log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2373 }
2374 }
2375
2376 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2377 Klass::metaspace_pointers_do(it);
2378
2379 if (log_is_enabled(Trace, cds)) {
2380 ResourceMark rm;
2381 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2382 }
2383
2384 it->push(&_annotations);
2385 it->push((Klass**)&_array_klasses);
2386 it->push(&_constants);
2387 it->push(&_inner_classes);
2388 it->push(&_array_name);
2389 #if INCLUDE_JVMTI
2390 it->push(&_previous_versions);
2391 #endif
2392 it->push(&_methods);
2393 it->push(&_default_methods);
2394 it->push(&_local_interfaces);
2395 it->push(&_transitive_interfaces);
2396 it->push(&_method_ordering);
2397 it->push(&_default_vtable_indices);
2398 it->push(&_fields);
2399
2400 if (itable_length() > 0) {
2401 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2402 int method_table_offset_in_words = ioe->offset()/wordSize;
2403 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2404 / itableOffsetEntry::size();
2405
2406 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2407 if (ioe->interface_klass() != NULL) {
2408 it->push(ioe->interface_klass_addr());
2409 itableMethodEntry* ime = ioe->first_method_entry(this);
2410 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2411 for (int index = 0; index < n; index ++) {
2412 it->push(ime[index].method_addr());
2413 }
2414 }
2415 }
2416 }
2417
2418 it->push(&_nest_members);
2419 }
2420
2421 void InstanceKlass::remove_unshareable_info() {
2422 Klass::remove_unshareable_info();
2423
2424 if (is_in_error_state()) {
2425 // Classes are attempted to link during dumping and may fail,
2426 // but these classes are still in the dictionary and class list in CLD.
2427 // Check in_error state first because in_error is > linked state, so
2428 // is_linked() is true.
2429 // If there's a linking error, there is nothing else to remove.
2430 return;
2431 }
2432
2433 // Reset to the 'allocated' state to prevent any premature accessing to
2434 // a shared class at runtime while the class is still being loaded and
2435 // restored. A class' init_state is set to 'loaded' at runtime when it's
2436 // being added to class hierarchy (see SystemDictionary:::add_to_hierarchy()).
2437 _init_state = allocated;
2438
2439 {
2440 MutexLocker ml(Compile_lock);
2441 init_implementor();
2442 }
2443
2444 constants()->remove_unshareable_info();
2445
2446 for (int i = 0; i < methods()->length(); i++) {
2447 Method* m = methods()->at(i);
2448 m->remove_unshareable_info();
2449 }
2450
2451 // do array classes also.
2452 if (array_klasses() != NULL) {
2453 array_klasses()->remove_unshareable_info();
2454 }
2455
2456 // These are not allocated from metaspace, but they should should all be empty
2457 // during dump time, so we don't need to worry about them in InstanceKlass::iterate().
2458 guarantee(_source_debug_extension == NULL, "must be");
2459 guarantee(_dep_context == NULL, "must be");
2460 guarantee(_osr_nmethods_head == NULL, "must be");
2461
2462 #if INCLUDE_JVMTI
2463 guarantee(_breakpoints == NULL, "must be");
2464 guarantee(_previous_versions == NULL, "must be");
2465 _cached_class_file = NULL;
2466 #endif
2467
2468 _init_thread = NULL;
2469 _methods_jmethod_ids = NULL;
2470 _jni_ids = NULL;
2471 _oop_map_cache = NULL;
2472 // clear _nest_host to ensure re-load at runtime
2473 _nest_host = NULL;
2474 }
2475
2476 void InstanceKlass::remove_java_mirror() {
2477 Klass::remove_java_mirror();
2478
2479 // do array classes also.
2480 if (array_klasses() != NULL) {
2481 array_klasses()->remove_java_mirror();
2482 }
2483 }
2484
2485 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2486 // SystemDictionary::add_to_hierarchy() sets the init_state to loaded
2487 // before the InstanceKlass is added to the SystemDictionary. Make
2488 // sure the current state is <loaded.
2489 assert(!is_loaded(), "invalid init state");
2490 set_package(loader_data, CHECK);
2491 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2492
2493 Array<Method*>* methods = this->methods();
2494 int num_methods = methods->length();
2495 for (int index = 0; index < num_methods; ++index) {
2496 methods->at(index)->restore_unshareable_info(CHECK);
2497 }
2498 if (JvmtiExport::has_redefined_a_class()) {
2499 // Reinitialize vtable because RedefineClasses may have changed some
2500 // entries in this vtable for super classes so the CDS vtable might
2501 // point to old or obsolete entries. RedefineClasses doesn't fix up
2502 // vtables in the shared system dictionary, only the main one.
2503 // It also redefines the itable too so fix that too.
2504 vtable().initialize_vtable(false, CHECK);
2505 itable().initialize_itable(false, CHECK);
2506 }
2507
2508 // restore constant pool resolved references
2509 constants()->restore_unshareable_info(CHECK);
2510
2511 if (array_klasses() != NULL) {
2512 // Array classes have null protection domain.
2513 // --> see ArrayKlass::complete_create_array_klass()
2514 array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2515 }
2516 }
2517
2518 // returns true IFF is_in_error_state() has been changed as a result of this call.
2519 bool InstanceKlass::check_sharing_error_state() {
2520 assert(DumpSharedSpaces, "should only be called during dumping");
2521 bool old_state = is_in_error_state();
2522
2523 if (!is_in_error_state()) {
2524 bool bad = false;
2525 for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2526 if (sup->is_in_error_state()) {
2527 bad = true;
2528 break;
2529 }
2530 }
2531 if (!bad) {
2532 Array<InstanceKlass*>* interfaces = transitive_interfaces();
2533 for (int i = 0; i < interfaces->length(); i++) {
2534 InstanceKlass* iface = interfaces->at(i);
2535 if (iface->is_in_error_state()) {
2536 bad = true;
2537 break;
2538 }
2539 }
2540 }
2541
2542 if (bad) {
2543 set_in_error_state();
2544 }
2545 }
2546
2547 return (old_state != is_in_error_state());
2548 }
2549
2550 #if INCLUDE_JVMTI
2551 static void clear_all_breakpoints(Method* m) {
2552 m->clear_all_breakpoints();
2553 }
2554 #endif
2555
2556 void InstanceKlass::unload_class(InstanceKlass* ik) {
2557 // Release dependencies.
2558 ik->dependencies().remove_all_dependents();
2559
2560 // notify the debugger
2561 if (JvmtiExport::should_post_class_unload()) {
2562 JvmtiExport::post_class_unload(ik);
2563 }
2564
2565 // notify ClassLoadingService of class unload
2566 ClassLoadingService::notify_class_unloaded(ik);
2567
2568 if (log_is_enabled(Info, class, unload)) {
2569 ResourceMark rm;
2570 log_info(class, unload)("unloading class %s " INTPTR_FORMAT, ik->external_name(), p2i(ik));
2571 }
2572
2573 Events::log_class_unloading(Thread::current(), ik);
2574
2575 #if INCLUDE_JFR
2576 assert(ik != NULL, "invariant");
2577 EventClassUnload event;
2578 event.set_unloadedClass(ik);
2579 event.set_definingClassLoader(ik->class_loader_data());
2580 event.commit();
2581 #endif
2582 }
2583
2584 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2585 // Clean up C heap
2586 ik->release_C_heap_structures();
2587 ik->constants()->release_C_heap_structures();
2588 }
2589
2590 void InstanceKlass::release_C_heap_structures() {
2591 // Can't release the constant pool here because the constant pool can be
2592 // deallocated separately from the InstanceKlass for default methods and
2593 // redefine classes.
2594
2595 // Deallocate oop map cache
2596 if (_oop_map_cache != NULL) {
2597 delete _oop_map_cache;
2598 _oop_map_cache = NULL;
2599 }
2600
2601 // Deallocate JNI identifiers for jfieldIDs
2602 JNIid::deallocate(jni_ids());
2603 set_jni_ids(NULL);
2604
2605 jmethodID* jmeths = methods_jmethod_ids_acquire();
2606 if (jmeths != (jmethodID*)NULL) {
2607 release_set_methods_jmethod_ids(NULL);
2608 FreeHeap(jmeths);
2609 }
2610
2611 assert(_dep_context == NULL,
2612 "dependencies should already be cleaned");
2613
2614 #if INCLUDE_JVMTI
2615 // Deallocate breakpoint records
2616 if (breakpoints() != 0x0) {
2617 methods_do(clear_all_breakpoints);
2618 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2619 }
2620
2621 // deallocate the cached class file
2622 if (_cached_class_file != NULL) {
2623 os::free(_cached_class_file);
2624 _cached_class_file = NULL;
2625 }
2626 #endif
2627
2628 // Decrement symbol reference counts associated with the unloaded class.
2629 if (_name != NULL) _name->decrement_refcount();
2630 // unreference array name derived from this class name (arrays of an unloaded
2631 // class can't be referenced anymore).
2632 if (_array_name != NULL) _array_name->decrement_refcount();
2633 if (_value_types != NULL) {
2634 for (int i = 0; i < _value_types->length(); i++) {
2635 Symbol* s = _value_types->at(i)._class_name;
2636 if (s != NULL) {
2637 s->decrement_refcount();
2638 }
2639 }
2640 }
2641 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2642 }
2643
2644 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2645 if (array == NULL) {
2646 _source_debug_extension = NULL;
2647 } else {
2648 // Adding one to the attribute length in order to store a null terminator
2649 // character could cause an overflow because the attribute length is
2650 // already coded with an u4 in the classfile, but in practice, it's
2651 // unlikely to happen.
2652 assert((length+1) > length, "Overflow checking");
2653 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2654 for (int i = 0; i < length; i++) {
2655 sde[i] = array[i];
2656 }
2657 sde[length] = '\0';
2658 _source_debug_extension = sde;
2659 }
2660 }
2661
2662 const char* InstanceKlass::signature_name() const {
2663 return signature_name_of(is_value() ? 'Q' : 'L');
2664 }
2665
2666 const char* InstanceKlass::signature_name_of(char c) const {
2667 int hash_len = 0;
2668 char hash_buf[40];
2669
2670 // If this is an unsafe anonymous class, append a hash to make the name unique
2671 if (is_unsafe_anonymous()) {
2672 intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2673 jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2674 hash_len = (int)strlen(hash_buf);
2675 }
2676
2677 // Get the internal name as a c string
2678 const char* src = (const char*) (name()->as_C_string());
2679 const int src_length = (int)strlen(src);
2680
2681 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2682
2683 // Add L or Q as type indicator
2684 int dest_index = 0;
2685 dest[dest_index++] = c;
2686
2687 // Add the actual class name
2688 for (int src_index = 0; src_index < src_length; ) {
2689 dest[dest_index++] = src[src_index++];
2690 }
2691
2692 // If we have a hash, append it
2693 for (int hash_index = 0; hash_index < hash_len; ) {
2694 dest[dest_index++] = hash_buf[hash_index++];
2695 }
2696
2697 // Add the semicolon and the NULL
2698 dest[dest_index++] = ';';
2699 dest[dest_index] = '\0';
2700 return dest;
2701 }
2702
2703 // Used to obtain the package name from a fully qualified class name.
2704 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2705 if (name == NULL) {
2706 return NULL;
2707 } else {
2708 if (name->utf8_length() <= 0) {
2709 return NULL;
2710 }
2711 ResourceMark rm;
2712 const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2713 if (package_name == NULL) {
2714 return NULL;
2715 }
2716 Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD);
2717 return pkg_name;
2718 }
2719 }
2720
2721 ModuleEntry* InstanceKlass::module() const {
2722 // For an unsafe anonymous class return the host class' module
2723 if (is_unsafe_anonymous()) {
2724 assert(unsafe_anonymous_host() != NULL, "unsafe anonymous class must have a host class");
2725 return unsafe_anonymous_host()->module();
2726 }
2727
2728 // Class is in a named package
2729 if (!in_unnamed_package()) {
2730 return _package_entry->module();
2731 }
2732
2733 // Class is in an unnamed package, return its loader's unnamed module
2734 return class_loader_data()->unnamed_module();
2735 }
2736
2737 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2738
2739 // ensure java/ packages only loaded by boot or platform builtin loaders
2740 check_prohibited_package(name(), loader_data, CHECK);
2741
2742 TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2743
2744 if (pkg_name != NULL && loader_data != NULL) {
2745
2746 // Find in class loader's package entry table.
2747 _package_entry = loader_data->packages()->lookup_only(pkg_name);
2748
2749 // If the package name is not found in the loader's package
2750 // entry table, it is an indication that the package has not
2751 // been defined. Consider it defined within the unnamed module.
2752 if (_package_entry == NULL) {
2753 ResourceMark rm;
2754
2755 if (!ModuleEntryTable::javabase_defined()) {
2756 // Before java.base is defined during bootstrapping, define all packages in
2757 // the java.base module. If a non-java.base package is erroneously placed
2758 // in the java.base module it will be caught later when java.base
2759 // is defined by ModuleEntryTable::verify_javabase_packages check.
2760 assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2761 _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2762 } else {
2763 assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2764 _package_entry = loader_data->packages()->lookup(pkg_name,
2765 loader_data->unnamed_module());
2766 }
2767
2768 // A package should have been successfully created
2769 assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2770 name()->as_C_string(), loader_data->loader_name_and_id());
2771 }
2772
2773 if (log_is_enabled(Debug, module)) {
2774 ResourceMark rm;
2775 ModuleEntry* m = _package_entry->module();
2776 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2777 external_name(),
2778 pkg_name->as_C_string(),
2779 loader_data->loader_name_and_id(),
2780 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2781 }
2782 } else {
2783 ResourceMark rm;
2784 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2785 external_name(),
2786 (loader_data != NULL) ? loader_data->loader_name_and_id() : "NULL",
2787 UNNAMED_MODULE);
2788 }
2789 }
2790
2791
2792 // different versions of is_same_class_package
2793
2794 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2795 oop classloader1 = this->class_loader();
2796 PackageEntry* classpkg1 = this->package();
2797 if (class2->is_objArray_klass()) {
2798 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2799 }
2800
2801 oop classloader2;
2802 PackageEntry* classpkg2;
2803 if (class2->is_instance_klass()) {
2804 classloader2 = class2->class_loader();
2805 classpkg2 = class2->package();
2806 } else {
2807 assert(class2->is_typeArray_klass(), "should be type array");
2808 classloader2 = NULL;
2809 classpkg2 = NULL;
2810 }
2811
2812 // Same package is determined by comparing class loader
2813 // and package entries. Both must be the same. This rule
2814 // applies even to classes that are defined in the unnamed
2815 // package, they still must have the same class loader.
2816 if (oopDesc::equals(classloader1, classloader2) && (classpkg1 == classpkg2)) {
2817 return true;
2818 }
2819
2820 return false;
2821 }
2822
2823 // return true if this class and other_class are in the same package. Classloader
2824 // and classname information is enough to determine a class's package
2825 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2826 const Symbol* other_class_name) const {
2827 if (!oopDesc::equals(class_loader(), other_class_loader)) {
2828 return false;
2829 }
2830 if (name()->fast_compare(other_class_name) == 0) {
2831 return true;
2832 }
2833
2834 {
2835 ResourceMark rm;
2836
2837 bool bad_class_name = false;
2838 const char* other_pkg =
2839 ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2840 if (bad_class_name) {
2841 return false;
2842 }
2843 // Check that package_from_name() returns NULL, not "", if there is no package.
2844 assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2845
2846 const Symbol* const this_package_name =
2847 this->package() != NULL ? this->package()->name() : NULL;
2848
2849 if (this_package_name == NULL || other_pkg == NULL) {
2850 // One of the two doesn't have a package. Only return true if the other
2851 // one also doesn't have a package.
2852 return (const char*)this_package_name == other_pkg;
2853 }
2854
2855 // Check if package is identical
2856 return this_package_name->equals(other_pkg);
2857 }
2858 }
2859
2860 // Returns true iff super_method can be overridden by a method in targetclassname
2861 // See JLS 3rd edition 8.4.6.1
2862 // Assumes name-signature match
2863 // "this" is InstanceKlass of super_method which must exist
2864 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2865 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2866 // Private methods can not be overridden
2867 if (super_method->is_private()) {
2868 return false;
2869 }
2870 // If super method is accessible, then override
2871 if ((super_method->is_protected()) ||
2872 (super_method->is_public())) {
2873 return true;
2874 }
2875 // Package-private methods are not inherited outside of package
2876 assert(super_method->is_package_private(), "must be package private");
2877 return(is_same_class_package(targetclassloader(), targetclassname));
2878 }
2879
2880 // Only boot and platform class loaders can define classes in "java/" packages.
2881 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2882 ClassLoaderData* loader_data,
2883 TRAPS) {
2884 if (!loader_data->is_boot_class_loader_data() &&
2885 !loader_data->is_platform_class_loader_data() &&
2886 class_name != NULL) {
2887 ResourceMark rm(THREAD);
2888 char* name = class_name->as_C_string();
2889 if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2890 TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2891 assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2892 name = pkg_name->as_C_string();
2893 const char* class_loader_name = loader_data->loader_name_and_id();
2894 StringUtils::replace_no_expand(name, "/", ".");
2895 const char* msg_text1 = "Class loader (instance of): ";
2896 const char* msg_text2 = " tried to load prohibited package name: ";
2897 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2898 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2899 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2900 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2901 }
2902 }
2903 return;
2904 }
2905
2906 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2907 constantPoolHandle i_cp(THREAD, constants());
2908 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2909 int ioff = iter.inner_class_info_index();
2910 if (ioff != 0) {
2911 // Check to see if the name matches the class we're looking for
2912 // before attempting to find the class.
2913 if (i_cp->klass_name_at_matches(this, ioff)) {
2914 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2915 if (this == inner_klass) {
2916 *ooff = iter.outer_class_info_index();
2917 *noff = iter.inner_name_index();
2918 return true;
2919 }
2920 }
2921 }
2922 }
2923 return false;
2924 }
2925
2926 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2927 InstanceKlass* outer_klass = NULL;
2928 *inner_is_member = false;
2929 int ooff = 0, noff = 0;
2930 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2931 if (has_inner_classes_attr) {
2932 constantPoolHandle i_cp(THREAD, constants());
2933 if (ooff != 0) {
2934 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2935 outer_klass = InstanceKlass::cast(ok);
2936 *inner_is_member = true;
2937 }
2938 if (NULL == outer_klass) {
2939 // It may be unsafe anonymous; try for that.
2940 int encl_method_class_idx = enclosing_method_class_index();
2941 if (encl_method_class_idx != 0) {
2942 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2943 outer_klass = InstanceKlass::cast(ok);
2944 *inner_is_member = false;
2945 }
2946 }
2947 }
2948
2949 // If no inner class attribute found for this class.
2950 if (NULL == outer_klass) return NULL;
2951
2952 // Throws an exception if outer klass has not declared k as an inner klass
2953 // We need evidence that each klass knows about the other, or else
2954 // the system could allow a spoof of an inner class to gain access rights.
2955 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2956 return outer_klass;
2957 }
2958
2959 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2960 jint access = access_flags().as_int();
2961
2962 // But check if it happens to be member class.
2963 InnerClassesIterator iter(this);
2964 for (; !iter.done(); iter.next()) {
2965 int ioff = iter.inner_class_info_index();
2966 // Inner class attribute can be zero, skip it.
2967 // Strange but true: JVM spec. allows null inner class refs.
2968 if (ioff == 0) continue;
2969
2970 // only look at classes that are already loaded
2971 // since we are looking for the flags for our self.
2972 Symbol* inner_name = constants()->klass_name_at(ioff);
2973 if (name() == inner_name) {
2974 // This is really a member class.
2975 access = iter.inner_access_flags();
2976 break;
2977 }
2978 }
2979 // Remember to strip ACC_SUPER bit
2980 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2981 }
2982
2983 jint InstanceKlass::jvmti_class_status() const {
2984 jint result = 0;
2985
2986 if (is_linked()) {
2987 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2988 }
2989
2990 if (is_initialized()) {
2991 assert(is_linked(), "Class status is not consistent");
2992 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2993 }
2994 if (is_in_error_state()) {
2995 result |= JVMTI_CLASS_STATUS_ERROR;
2996 }
2997 return result;
2998 }
2999
3000 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
3001 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
3002 int method_table_offset_in_words = ioe->offset()/wordSize;
3003 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
3004 / itableOffsetEntry::size();
3005
3006 for (int cnt = 0 ; ; cnt ++, ioe ++) {
3007 // If the interface isn't implemented by the receiver class,
3008 // the VM should throw IncompatibleClassChangeError.
3009 if (cnt >= nof_interfaces) {
3010 ResourceMark rm(THREAD);
3011 stringStream ss;
3012 bool same_module = (module() == holder->module());
3013 ss.print("Receiver class %s does not implement "
3014 "the interface %s defining the method to be called "
3015 "(%s%s%s)",
3016 external_name(), holder->external_name(),
3017 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3018 (same_module) ? "" : "; ",
3019 (same_module) ? "" : holder->class_in_module_of_loader());
3020 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3021 }
3022
3023 Klass* ik = ioe->interface_klass();
3024 if (ik == holder) break;
3025 }
3026
3027 itableMethodEntry* ime = ioe->first_method_entry(this);
3028 Method* m = ime[index].method();
3029 if (m == NULL) {
3030 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3031 }
3032 return m;
3033 }
3034
3035
3036 #if INCLUDE_JVMTI
3037 // update default_methods for redefineclasses for methods that are
3038 // not yet in the vtable due to concurrent subclass define and superinterface
3039 // redefinition
3040 // Note: those in the vtable, should have been updated via adjust_method_entries
3041 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3042 // search the default_methods for uses of either obsolete or EMCP methods
3043 if (default_methods() != NULL) {
3044 for (int index = 0; index < default_methods()->length(); index ++) {
3045 Method* old_method = default_methods()->at(index);
3046 if (old_method == NULL || !old_method->is_old()) {
3047 continue; // skip uninteresting entries
3048 }
3049 assert(!old_method->is_deleted(), "default methods may not be deleted");
3050 Method* new_method = old_method->get_new_method();
3051 default_methods()->at_put(index, new_method);
3052
3053 if (log_is_enabled(Info, redefine, class, update)) {
3054 ResourceMark rm;
3055 if (!(*trace_name_printed)) {
3056 log_info(redefine, class, update)
3057 ("adjust: klassname=%s default methods from name=%s",
3058 external_name(), old_method->method_holder()->external_name());
3059 *trace_name_printed = true;
3060 }
3061 log_debug(redefine, class, update, vtables)
3062 ("default method update: %s(%s) ",
3063 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3064 }
3065 }
3066 }
3067 }
3068 #endif // INCLUDE_JVMTI
3069
3070 // On-stack replacement stuff
3071 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3072 // only one compilation can be active
3073 {
3074 // This is a short non-blocking critical region, so the no safepoint check is ok.
3075 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
3076 assert(n->is_osr_method(), "wrong kind of nmethod");
3077 n->set_osr_link(osr_nmethods_head());
3078 set_osr_nmethods_head(n);
3079 // Raise the highest osr level if necessary
3080 if (TieredCompilation) {
3081 Method* m = n->method();
3082 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
3083 }
3084 }
3085
3086 // Get rid of the osr methods for the same bci that have lower levels.
3087 if (TieredCompilation) {
3088 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3089 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3090 if (inv != NULL && inv->is_in_use()) {
3091 inv->make_not_entrant();
3092 }
3093 }
3094 }
3095 }
3096
3097 // Remove osr nmethod from the list. Return true if found and removed.
3098 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3099 // This is a short non-blocking critical region, so the no safepoint check is ok.
3100 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
3101 assert(n->is_osr_method(), "wrong kind of nmethod");
3102 nmethod* last = NULL;
3103 nmethod* cur = osr_nmethods_head();
3104 int max_level = CompLevel_none; // Find the max comp level excluding n
3105 Method* m = n->method();
3106 // Search for match
3107 bool found = false;
3108 while(cur != NULL && cur != n) {
3109 if (TieredCompilation && m == cur->method()) {
3110 // Find max level before n
3111 max_level = MAX2(max_level, cur->comp_level());
3112 }
3113 last = cur;
3114 cur = cur->osr_link();
3115 }
3116 nmethod* next = NULL;
3117 if (cur == n) {
3118 found = true;
3119 next = cur->osr_link();
3120 if (last == NULL) {
3121 // Remove first element
3122 set_osr_nmethods_head(next);
3123 } else {
3124 last->set_osr_link(next);
3125 }
3126 }
3127 n->set_osr_link(NULL);
3128 if (TieredCompilation) {
3129 cur = next;
3130 while (cur != NULL) {
3131 // Find max level after n
3132 if (m == cur->method()) {
3133 max_level = MAX2(max_level, cur->comp_level());
3134 }
3135 cur = cur->osr_link();
3136 }
3137 m->set_highest_osr_comp_level(max_level);
3138 }
3139 return found;
3140 }
3141
3142 int InstanceKlass::mark_osr_nmethods(const Method* m) {
3143 // This is a short non-blocking critical region, so the no safepoint check is ok.
3144 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
3145 nmethod* osr = osr_nmethods_head();
3146 int found = 0;
3147 while (osr != NULL) {
3148 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3149 if (osr->method() == m) {
3150 osr->mark_for_deoptimization();
3151 found++;
3152 }
3153 osr = osr->osr_link();
3154 }
3155 return found;
3156 }
3157
3158 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3159 // This is a short non-blocking critical region, so the no safepoint check is ok.
3160 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
3161 nmethod* osr = osr_nmethods_head();
3162 nmethod* best = NULL;
3163 while (osr != NULL) {
3164 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3165 // There can be a time when a c1 osr method exists but we are waiting
3166 // for a c2 version. When c2 completes its osr nmethod we will trash
3167 // the c1 version and only be able to find the c2 version. However
3168 // while we overflow in the c1 code at back branches we don't want to
3169 // try and switch to the same code as we are already running
3170
3171 if (osr->method() == m &&
3172 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3173 if (match_level) {
3174 if (osr->comp_level() == comp_level) {
3175 // Found a match - return it.
3176 return osr;
3177 }
3178 } else {
3179 if (best == NULL || (osr->comp_level() > best->comp_level())) {
3180 if (osr->comp_level() == CompLevel_highest_tier) {
3181 // Found the best possible - return it.
3182 return osr;
3183 }
3184 best = osr;
3185 }
3186 }
3187 }
3188 osr = osr->osr_link();
3189 }
3190 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
3191 return best;
3192 }
3193 return NULL;
3194 }
3195
3196 // -----------------------------------------------------------------------------------------------------
3197 // Printing
3198
3199 #ifndef PRODUCT
3200
3201 #define BULLET " - "
3202
3203 static const char* state_names[] = {
3204 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3205 };
3206
3207 static void print_vtable(address self, intptr_t* start, int len, outputStream* st) {
3208 ResourceMark rm;
3209 int* forward_refs = NEW_RESOURCE_ARRAY(int, len);
3210 for (int i = 0; i < len; i++) forward_refs[i] = 0;
3211 for (int i = 0; i < len; i++) {
3212 intptr_t e = start[i];
3213 st->print("%d : " INTPTR_FORMAT, i, e);
3214 if (forward_refs[i] != 0) {
3215 int from = forward_refs[i];
3216 int off = (int) start[from];
3217 st->print(" (offset %d <= [%d])", off, from);
3218 }
3219 if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
3220 st->print(" ");
3221 ((Metadata*)e)->print_value_on(st);
3222 } else if (self != NULL && e > 0 && e < 0x10000) {
3223 address location = self + e;
3224 int index = (int)((intptr_t*)location - start);
3225 st->print(" (offset %d => [%d])", (int)e, index);
3226 if (index >= 0 && index < len)
3227 forward_refs[index] = i;
3228 }
3229 st->cr();
3230 }
3231 }
3232
3233 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3234 return print_vtable(NULL, reinterpret_cast<intptr_t*>(start), len, st);
3235 }
3236
3237 template<typename T>
3238 static void print_array_on(outputStream* st, Array<T>* array) {
3239 if (array == NULL) { st->print_cr("NULL"); return; }
3240 array->print_value_on(st); st->cr();
3241 if (Verbose || WizardMode) {
3242 for (int i = 0; i < array->length(); i++) {
3243 st->print("%d : ", i); array->at(i)->print_value_on(st); st->cr();
3244 }
3245 }
3246 }
3247
3248 static void print_array_on(outputStream* st, Array<int>* array) {
3249 if (array == NULL) { st->print_cr("NULL"); return; }
3250 array->print_value_on(st); st->cr();
3251 if (Verbose || WizardMode) {
3252 for (int i = 0; i < array->length(); i++) {
3253 st->print("%d : %d", i, array->at(i)); st->cr();
3254 }
3255 }
3256 }
3257
3258 void InstanceKlass::print_on(outputStream* st) const {
3259 assert(is_klass(), "must be klass");
3260 Klass::print_on(st);
3261
3262 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3263 st->print(BULLET"klass size: %d", size()); st->cr();
3264 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3265 st->print(BULLET"misc flags: 0x%x", _misc_flags); st->cr();
3266 st->print(BULLET"state: "); st->print_cr("%s", state_names[_init_state]);
3267 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3268 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3269 st->print(BULLET"sub: ");
3270 Klass* sub = subklass();
3271 int n;
3272 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
3273 if (n < MaxSubklassPrintSize) {
3274 sub->print_value_on(st);
3275 st->print(" ");
3276 }
3277 }
3278 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3279 st->cr();
3280
3281 if (is_interface()) {
3282 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3283 if (nof_implementors() == 1) {
3284 st->print_cr(BULLET"implementor: ");
3285 st->print(" ");
3286 implementor()->print_value_on(st);
3287 st->cr();
3288 }
3289 }
3290
3291 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3292 st->print(BULLET"methods: "); print_array_on(st, methods());
3293 st->print(BULLET"method ordering: "); print_array_on(st, method_ordering());
3294 st->print(BULLET"default_methods: "); print_array_on(st, default_methods());
3295 if (default_vtable_indices() != NULL) {
3296 st->print(BULLET"default vtable indices: "); print_array_on(st, default_vtable_indices());
3297 }
3298 st->print(BULLET"local interfaces: "); print_array_on(st, local_interfaces());
3299 st->print(BULLET"trans. interfaces: "); print_array_on(st, transitive_interfaces());
3300 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3301 if (class_loader_data() != NULL) {
3302 st->print(BULLET"class loader data: ");
3303 class_loader_data()->print_value_on(st);
3304 st->cr();
3305 }
3306 st->print(BULLET"unsafe anonymous host class: "); Metadata::print_value_on_maybe_null(st, unsafe_anonymous_host()); st->cr();
3307 if (source_file_name() != NULL) {
3308 st->print(BULLET"source file: ");
3309 source_file_name()->print_value_on(st);
3310 st->cr();
3311 }
3312 if (source_debug_extension() != NULL) {
3313 st->print(BULLET"source debug extension: ");
3314 st->print("%s", source_debug_extension());
3315 st->cr();
3316 }
3317 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
3318 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
3319 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
3320 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
3321 {
3322 bool have_pv = false;
3323 // previous versions are linked together through the InstanceKlass
3324 for (InstanceKlass* pv_node = previous_versions();
3325 pv_node != NULL;
3326 pv_node = pv_node->previous_versions()) {
3327 if (!have_pv)
3328 st->print(BULLET"previous version: ");
3329 have_pv = true;
3330 pv_node->constants()->print_value_on(st);
3331 }
3332 if (have_pv) st->cr();
3333 }
3334
3335 if (generic_signature() != NULL) {
3336 st->print(BULLET"generic signature: ");
3337 generic_signature()->print_value_on(st);
3338 st->cr();
3339 }
3340 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3341 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3342 if (java_mirror() != NULL) {
3343 st->print(BULLET"java mirror: ");
3344 java_mirror()->print_value_on(st);
3345 st->cr();
3346 } else {
3347 st->print_cr(BULLET"java mirror: NULL");
3348 }
3349 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3350 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3351 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3352 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(NULL, start_of_itable(), itable_length(), st);
3353 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3354 FieldPrinter print_static_field(st);
3355 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3356 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3357 FieldPrinter print_nonstatic_field(st);
3358 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3359 ik->do_nonstatic_fields(&print_nonstatic_field);
3360
3361 st->print(BULLET"non-static oop maps: ");
3362 OopMapBlock* map = start_of_nonstatic_oop_maps();
3363 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3364 while (map < end_map) {
3365 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3366 map++;
3367 }
3368 st->cr();
3369 }
3370
3371 #endif //PRODUCT
3372
3373 void InstanceKlass::print_value_on(outputStream* st) const {
3374 assert(is_klass(), "must be klass");
3375 if (Verbose || WizardMode) access_flags().print_on(st);
3376 name()->print_value_on(st);
3377 }
3378
3379 #ifndef PRODUCT
3380
3381 void FieldPrinter::do_field(fieldDescriptor* fd) {
3382 _st->print(BULLET);
3383 if (_obj == NULL) {
3384 fd->print_on(_st);
3385 _st->cr();
3386 } else {
3387 fd->print_on_for(_st, _obj);
3388 _st->cr();
3389 }
3390 }
3391
3392
3393 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3394 Klass::oop_print_on(obj, st);
3395
3396 if (this == SystemDictionary::String_klass()) {
3397 typeArrayOop value = java_lang_String::value(obj);
3398 juint length = java_lang_String::length(obj);
3399 if (value != NULL &&
3400 value->is_typeArray() &&
3401 length <= (juint) value->length()) {
3402 st->print(BULLET"string: ");
3403 java_lang_String::print(obj, st);
3404 st->cr();
3405 if (!WizardMode) return; // that is enough
3406 }
3407 }
3408
3409 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3410 FieldPrinter print_field(st, obj);
3411 do_nonstatic_fields(&print_field);
3412
3413 if (this == SystemDictionary::Class_klass()) {
3414 st->print(BULLET"signature: ");
3415 java_lang_Class::print_signature(obj, st);
3416 st->cr();
3417 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3418 st->print(BULLET"fake entry for mirror: ");
3419 Metadata::print_value_on_maybe_null(st, mirrored_klass);
3420 st->cr();
3421 Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3422 st->print(BULLET"fake entry for array: ");
3423 Metadata::print_value_on_maybe_null(st, array_klass);
3424 st->cr();
3425 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3426 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3427 Klass* real_klass = java_lang_Class::as_Klass(obj);
3428 if (real_klass != NULL && real_klass->is_instance_klass()) {
3429 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3430 }
3431 } else if (this == SystemDictionary::MethodType_klass()) {
3432 st->print(BULLET"signature: ");
3433 java_lang_invoke_MethodType::print_signature(obj, st);
3434 st->cr();
3435 }
3436 }
3437
3438 bool InstanceKlass::verify_itable_index(int i) {
3439 int method_count = klassItable::method_count_for_interface(this);
3440 assert(i >= 0 && i < method_count, "index out of bounds");
3441 return true;
3442 }
3443
3444 #endif //PRODUCT
3445
3446 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3447 st->print("a ");
3448 name()->print_value_on(st);
3449 obj->print_address_on(st);
3450 if (this == SystemDictionary::String_klass()
3451 && java_lang_String::value(obj) != NULL) {
3452 ResourceMark rm;
3453 int len = java_lang_String::length(obj);
3454 int plen = (len < 24 ? len : 12);
3455 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3456 st->print(" = \"%s\"", str);
3457 if (len > plen)
3458 st->print("...[%d]", len);
3459 } else if (this == SystemDictionary::Class_klass()) {
3460 Klass* k = java_lang_Class::as_Klass(obj);
3461 st->print(" = ");
3462 if (k != NULL) {
3463 k->print_value_on(st);
3464 } else {
3465 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3466 st->print("%s", tname ? tname : "type?");
3467 }
3468 } else if (this == SystemDictionary::MethodType_klass()) {
3469 st->print(" = ");
3470 java_lang_invoke_MethodType::print_signature(obj, st);
3471 } else if (java_lang_boxing_object::is_instance(obj)) {
3472 st->print(" = ");
3473 java_lang_boxing_object::print(obj, st);
3474 } else if (this == SystemDictionary::LambdaForm_klass()) {
3475 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3476 if (vmentry != NULL) {
3477 st->print(" => ");
3478 vmentry->print_value_on(st);
3479 }
3480 } else if (this == SystemDictionary::MemberName_klass()) {
3481 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3482 if (vmtarget != NULL) {
3483 st->print(" = ");
3484 vmtarget->print_value_on(st);
3485 } else {
3486 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3487 st->print(".");
3488 java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3489 }
3490 }
3491 }
3492
3493 const char* InstanceKlass::internal_name() const {
3494 return external_name();
3495 }
3496
3497 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3498 const char* module_name,
3499 const ClassFileStream* cfs) const {
3500 if (!log_is_enabled(Info, class, load)) {
3501 return;
3502 }
3503
3504 ResourceMark rm;
3505 LogMessage(class, load) msg;
3506 stringStream info_stream;
3507
3508 // Name and class hierarchy info
3509 info_stream.print("%s", external_name());
3510
3511 // Source
3512 if (cfs != NULL) {
3513 if (cfs->source() != NULL) {
3514 if (module_name != NULL) {
3515 if (ClassLoader::is_modules_image(cfs->source())) {
3516 info_stream.print(" source: jrt:/%s", module_name);
3517 } else {
3518 info_stream.print(" source: %s", cfs->source());
3519 }
3520 } else {
3521 info_stream.print(" source: %s", cfs->source());
3522 }
3523 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3524 Thread* THREAD = Thread::current();
3525 Klass* caller =
3526 THREAD->is_Java_thread()
3527 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3528 : NULL;
3529 // caller can be NULL, for example, during a JVMTI VM_Init hook
3530 if (caller != NULL) {
3531 info_stream.print(" source: instance of %s", caller->external_name());
3532 } else {
3533 // source is unknown
3534 }
3535 } else {
3536 oop class_loader = loader_data->class_loader();
3537 info_stream.print(" source: %s", class_loader->klass()->external_name());
3538 }
3539 } else {
3540 info_stream.print(" source: shared objects file");
3541 }
3542
3543 msg.info("%s", info_stream.as_string());
3544
3545 if (log_is_enabled(Debug, class, load)) {
3546 stringStream debug_stream;
3547
3548 // Class hierarchy info
3549 debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3550 p2i(this), p2i(superklass()));
3551
3552 // Interfaces
3553 if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3554 debug_stream.print(" interfaces:");
3555 int length = local_interfaces()->length();
3556 for (int i = 0; i < length; i++) {
3557 debug_stream.print(" " INTPTR_FORMAT,
3558 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3559 }
3560 }
3561
3562 // Class loader
3563 debug_stream.print(" loader: [");
3564 loader_data->print_value_on(&debug_stream);
3565 debug_stream.print("]");
3566
3567 // Classfile checksum
3568 if (cfs) {
3569 debug_stream.print(" bytes: %d checksum: %08x",
3570 cfs->length(),
3571 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3572 cfs->length()));
3573 }
3574
3575 msg.debug("%s", debug_stream.as_string());
3576 }
3577 }
3578
3579 #if INCLUDE_SERVICES
3580 // Size Statistics
3581 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3582 Klass::collect_statistics(sz);
3583
3584 sz->_inst_size = wordSize * size_helper();
3585 sz->_vtab_bytes = wordSize * vtable_length();
3586 sz->_itab_bytes = wordSize * itable_length();
3587 sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3588
3589 int n = 0;
3590 n += (sz->_methods_array_bytes = sz->count_array(methods()));
3591 n += (sz->_method_ordering_bytes = sz->count_array(method_ordering()));
3592 n += (sz->_local_interfaces_bytes = sz->count_array(local_interfaces()));
3593 n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3594 n += (sz->_fields_bytes = sz->count_array(fields()));
3595 n += (sz->_inner_classes_bytes = sz->count_array(inner_classes()));
3596 n += (sz->_nest_members_bytes = sz->count_array(nest_members()));
3597 sz->_ro_bytes += n;
3598
3599 const ConstantPool* cp = constants();
3600 if (cp) {
3601 cp->collect_statistics(sz);
3602 }
3603
3604 const Annotations* anno = annotations();
3605 if (anno) {
3606 anno->collect_statistics(sz);
3607 }
3608
3609 const Array<Method*>* methods_array = methods();
3610 if (methods()) {
3611 for (int i = 0; i < methods_array->length(); i++) {
3612 Method* method = methods_array->at(i);
3613 if (method) {
3614 sz->_method_count ++;
3615 method->collect_statistics(sz);
3616 }
3617 }
3618 }
3619 }
3620 #endif // INCLUDE_SERVICES
3621
3622 // Verification
3623
3624 class VerifyFieldClosure: public BasicOopIterateClosure {
3625 protected:
3626 template <class T> void do_oop_work(T* p) {
3627 oop obj = RawAccess<>::oop_load(p);
3628 if (!oopDesc::is_oop_or_null(obj)) {
3629 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3630 Universe::print_on(tty);
3631 guarantee(false, "boom");
3632 }
3633 }
3634 public:
3635 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3636 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3637 };
3638
3639 void InstanceKlass::verify_on(outputStream* st) {
3640 #ifndef PRODUCT
3641 // Avoid redundant verifies, this really should be in product.
3642 if (_verify_count == Universe::verify_count()) return;
3643 _verify_count = Universe::verify_count();
3644 #endif
3645
3646 // Verify Klass
3647 Klass::verify_on(st);
3648
3649 // Verify that klass is present in ClassLoaderData
3650 guarantee(class_loader_data()->contains_klass(this),
3651 "this class isn't found in class loader data");
3652
3653 // Verify vtables
3654 if (is_linked()) {
3655 // $$$ This used to be done only for m/s collections. Doing it
3656 // always seemed a valid generalization. (DLD -- 6/00)
3657 vtable().verify(st);
3658 }
3659
3660 // Verify first subklass
3661 if (subklass() != NULL) {
3662 guarantee(subklass()->is_klass(), "should be klass");
3663 }
3664
3665 // Verify siblings
3666 Klass* super = this->super();
3667 Klass* sib = next_sibling();
3668 if (sib != NULL) {
3669 if (sib == this) {
3670 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3671 }
3672
3673 guarantee(sib->is_klass(), "should be klass");
3674 guarantee(sib->super() == super, "siblings should have same superklass");
3675 }
3676
3677 // Verify local interfaces
3678 if (local_interfaces()) {
3679 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
3680 for (int j = 0; j < local_interfaces->length(); j++) {
3681 InstanceKlass* e = local_interfaces->at(j);
3682 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3683 }
3684 }
3685
3686 // Verify transitive interfaces
3687 if (transitive_interfaces() != NULL) {
3688 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
3689 for (int j = 0; j < transitive_interfaces->length(); j++) {
3690 InstanceKlass* e = transitive_interfaces->at(j);
3691 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3692 }
3693 }
3694
3695 // Verify methods
3696 if (methods() != NULL) {
3697 Array<Method*>* methods = this->methods();
3698 for (int j = 0; j < methods->length(); j++) {
3699 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3700 }
3701 for (int j = 0; j < methods->length() - 1; j++) {
3702 Method* m1 = methods->at(j);
3703 Method* m2 = methods->at(j + 1);
3704 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3705 }
3706 }
3707
3708 // Verify method ordering
3709 if (method_ordering() != NULL) {
3710 Array<int>* method_ordering = this->method_ordering();
3711 int length = method_ordering->length();
3712 if (JvmtiExport::can_maintain_original_method_order() ||
3713 ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3714 guarantee(length == methods()->length(), "invalid method ordering length");
3715 jlong sum = 0;
3716 for (int j = 0; j < length; j++) {
3717 int original_index = method_ordering->at(j);
3718 guarantee(original_index >= 0, "invalid method ordering index");
3719 guarantee(original_index < length, "invalid method ordering index");
3720 sum += original_index;
3721 }
3722 // Verify sum of indices 0,1,...,length-1
3723 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3724 } else {
3725 guarantee(length == 0, "invalid method ordering length");
3726 }
3727 }
3728
3729 // Verify default methods
3730 if (default_methods() != NULL) {
3731 Array<Method*>* methods = this->default_methods();
3732 for (int j = 0; j < methods->length(); j++) {
3733 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3734 }
3735 for (int j = 0; j < methods->length() - 1; j++) {
3736 Method* m1 = methods->at(j);
3737 Method* m2 = methods->at(j + 1);
3738 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3739 }
3740 }
3741
3742 // Verify JNI static field identifiers
3743 if (jni_ids() != NULL) {
3744 jni_ids()->verify(this);
3745 }
3746
3747 // Verify other fields
3748 if (array_klasses() != NULL) {
3749 guarantee(array_klasses()->is_klass(), "should be klass");
3750 }
3751 if (constants() != NULL) {
3752 guarantee(constants()->is_constantPool(), "should be constant pool");
3753 }
3754 const Klass* anonymous_host = unsafe_anonymous_host();
3755 if (anonymous_host != NULL) {
3756 guarantee(anonymous_host->is_klass(), "should be klass");
3757 }
3758 }
3759
3760 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3761 Klass::oop_verify_on(obj, st);
3762 VerifyFieldClosure blk;
3763 obj->oop_iterate(&blk);
3764 }
3765
3766
3767 // JNIid class for jfieldIDs only
3768 // Note to reviewers:
3769 // These JNI functions are just moved over to column 1 and not changed
3770 // in the compressed oops workspace.
3771 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3772 _holder = holder;
3773 _offset = offset;
3774 _next = next;
3775 debug_only(_is_static_field_id = false;)
3776 }
3777
3778
3779 JNIid* JNIid::find(int offset) {
3780 JNIid* current = this;
3781 while (current != NULL) {
3782 if (current->offset() == offset) return current;
3783 current = current->next();
3784 }
3785 return NULL;
3786 }
3787
3788 void JNIid::deallocate(JNIid* current) {
3789 while (current != NULL) {
3790 JNIid* next = current->next();
3791 delete current;
3792 current = next;
3793 }
3794 }
3795
3796
3797 void JNIid::verify(Klass* holder) {
3798 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3799 int end_field_offset;
3800 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3801
3802 JNIid* current = this;
3803 while (current != NULL) {
3804 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3805 #ifdef ASSERT
3806 int o = current->offset();
3807 if (current->is_static_field_id()) {
3808 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3809 }
3810 #endif
3811 current = current->next();
3812 }
3813 }
3814
3815 void InstanceKlass::set_init_state(ClassState state) {
3816 #ifdef ASSERT
3817 bool good_state = is_shared() ? (_init_state <= state)
3818 : (_init_state < state);
3819 assert(good_state || state == allocated, "illegal state transition");
3820 #endif
3821 _init_state = (u1)state;
3822 }
3823
3824 #if INCLUDE_JVMTI
3825
3826 // RedefineClasses() support for previous versions
3827
3828 // Globally, there is at least one previous version of a class to walk
3829 // during class unloading, which is saved because old methods in the class
3830 // are still running. Otherwise the previous version list is cleaned up.
3831 bool InstanceKlass::_has_previous_versions = false;
3832
3833 // Returns true if there are previous versions of a class for class
3834 // unloading only. Also resets the flag to false. purge_previous_version
3835 // will set the flag to true if there are any left, i.e., if there's any
3836 // work to do for next time. This is to avoid the expensive code cache
3837 // walk in CLDG::clean_deallocate_lists().
3838 bool InstanceKlass::has_previous_versions_and_reset() {
3839 bool ret = _has_previous_versions;
3840 log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3841 ret ? "true" : "false");
3842 _has_previous_versions = false;
3843 return ret;
3844 }
3845
3846 // Purge previous versions before adding new previous versions of the class and
3847 // during class unloading.
3848 void InstanceKlass::purge_previous_version_list() {
3849 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3850 assert(has_been_redefined(), "Should only be called for main class");
3851
3852 // Quick exit.
3853 if (previous_versions() == NULL) {
3854 return;
3855 }
3856
3857 // This klass has previous versions so see what we can cleanup
3858 // while it is safe to do so.
3859
3860 int deleted_count = 0; // leave debugging breadcrumbs
3861 int live_count = 0;
3862 ClassLoaderData* loader_data = class_loader_data();
3863 assert(loader_data != NULL, "should never be null");
3864
3865 ResourceMark rm;
3866 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3867
3868 // previous versions are linked together through the InstanceKlass
3869 InstanceKlass* pv_node = previous_versions();
3870 InstanceKlass* last = this;
3871 int version = 0;
3872
3873 // check the previous versions list
3874 for (; pv_node != NULL; ) {
3875
3876 ConstantPool* pvcp = pv_node->constants();
3877 assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3878
3879 if (!pvcp->on_stack()) {
3880 // If the constant pool isn't on stack, none of the methods
3881 // are executing. Unlink this previous_version.
3882 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3883 // so will be deallocated during the next phase of class unloading.
3884 log_trace(redefine, class, iklass, purge)
3885 ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3886 // For debugging purposes.
3887 pv_node->set_is_scratch_class();
3888 // Unlink from previous version list.
3889 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3890 InstanceKlass* next = pv_node->previous_versions();
3891 pv_node->link_previous_versions(NULL); // point next to NULL
3892 last->link_previous_versions(next);
3893 // Add to the deallocate list after unlinking
3894 loader_data->add_to_deallocate_list(pv_node);
3895 pv_node = next;
3896 deleted_count++;
3897 version++;
3898 continue;
3899 } else {
3900 log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3901 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3902 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3903 live_count++;
3904 // found a previous version for next time we do class unloading
3905 _has_previous_versions = true;
3906 }
3907
3908 // At least one method is live in this previous version.
3909 // Reset dead EMCP methods not to get breakpoints.
3910 // All methods are deallocated when all of the methods for this class are no
3911 // longer running.
3912 Array<Method*>* method_refs = pv_node->methods();
3913 if (method_refs != NULL) {
3914 log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3915 for (int j = 0; j < method_refs->length(); j++) {
3916 Method* method = method_refs->at(j);
3917
3918 if (!method->on_stack()) {
3919 // no breakpoints for non-running methods
3920 if (method->is_running_emcp()) {
3921 method->set_running_emcp(false);
3922 }
3923 } else {
3924 assert (method->is_obsolete() || method->is_running_emcp(),
3925 "emcp method cannot run after emcp bit is cleared");
3926 log_trace(redefine, class, iklass, purge)
3927 ("purge: %s(%s): prev method @%d in version @%d is alive",
3928 method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3929 }
3930 }
3931 }
3932 // next previous version
3933 last = pv_node;
3934 pv_node = pv_node->previous_versions();
3935 version++;
3936 }
3937 log_trace(redefine, class, iklass, purge)
3938 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3939 }
3940
3941 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3942 int emcp_method_count) {
3943 int obsolete_method_count = old_methods->length() - emcp_method_count;
3944
3945 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3946 _previous_versions != NULL) {
3947 // We have a mix of obsolete and EMCP methods so we have to
3948 // clear out any matching EMCP method entries the hard way.
3949 int local_count = 0;
3950 for (int i = 0; i < old_methods->length(); i++) {
3951 Method* old_method = old_methods->at(i);
3952 if (old_method->is_obsolete()) {
3953 // only obsolete methods are interesting
3954 Symbol* m_name = old_method->name();
3955 Symbol* m_signature = old_method->signature();
3956
3957 // previous versions are linked together through the InstanceKlass
3958 int j = 0;
3959 for (InstanceKlass* prev_version = _previous_versions;
3960 prev_version != NULL;
3961 prev_version = prev_version->previous_versions(), j++) {
3962
3963 Array<Method*>* method_refs = prev_version->methods();
3964 for (int k = 0; k < method_refs->length(); k++) {
3965 Method* method = method_refs->at(k);
3966
3967 if (!method->is_obsolete() &&
3968 method->name() == m_name &&
3969 method->signature() == m_signature) {
3970 // The current RedefineClasses() call has made all EMCP
3971 // versions of this method obsolete so mark it as obsolete
3972 log_trace(redefine, class, iklass, add)
3973 ("%s(%s): flush obsolete method @%d in version @%d",
3974 m_name->as_C_string(), m_signature->as_C_string(), k, j);
3975
3976 method->set_is_obsolete();
3977 break;
3978 }
3979 }
3980
3981 // The previous loop may not find a matching EMCP method, but
3982 // that doesn't mean that we can optimize and not go any
3983 // further back in the PreviousVersion generations. The EMCP
3984 // method for this generation could have already been made obsolete,
3985 // but there still may be an older EMCP method that has not
3986 // been made obsolete.
3987 }
3988
3989 if (++local_count >= obsolete_method_count) {
3990 // no more obsolete methods so bail out now
3991 break;
3992 }
3993 }
3994 }
3995 }
3996 }
3997
3998 // Save the scratch_class as the previous version if any of the methods are running.
3999 // The previous_versions are used to set breakpoints in EMCP methods and they are
4000 // also used to clean MethodData links to redefined methods that are no longer running.
4001 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4002 int emcp_method_count) {
4003 assert(Thread::current()->is_VM_thread(),
4004 "only VMThread can add previous versions");
4005
4006 ResourceMark rm;
4007 log_trace(redefine, class, iklass, add)
4008 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4009
4010 // Clean out old previous versions for this class
4011 purge_previous_version_list();
4012
4013 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4014 // a previous redefinition may be made obsolete by this redefinition.
4015 Array<Method*>* old_methods = scratch_class->methods();
4016 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4017
4018 // If the constant pool for this previous version of the class
4019 // is not marked as being on the stack, then none of the methods
4020 // in this previous version of the class are on the stack so
4021 // we don't need to add this as a previous version.
4022 ConstantPool* cp_ref = scratch_class->constants();
4023 if (!cp_ref->on_stack()) {
4024 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4025 // For debugging purposes.
4026 scratch_class->set_is_scratch_class();
4027 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4028 return;
4029 }
4030
4031 if (emcp_method_count != 0) {
4032 // At least one method is still running, check for EMCP methods
4033 for (int i = 0; i < old_methods->length(); i++) {
4034 Method* old_method = old_methods->at(i);
4035 if (!old_method->is_obsolete() && old_method->on_stack()) {
4036 // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
4037 // we can add breakpoints for it.
4038
4039 // We set the method->on_stack bit during safepoints for class redefinition
4040 // and use this bit to set the is_running_emcp bit.
4041 // After the safepoint, the on_stack bit is cleared and the running emcp
4042 // method may exit. If so, we would set a breakpoint in a method that
4043 // is never reached, but this won't be noticeable to the programmer.
4044 old_method->set_running_emcp(true);
4045 log_trace(redefine, class, iklass, add)
4046 ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
4047 } else if (!old_method->is_obsolete()) {
4048 log_trace(redefine, class, iklass, add)
4049 ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
4050 }
4051 }
4052 }
4053
4054 // Add previous version if any methods are still running.
4055 // Set has_previous_version flag for processing during class unloading.
4056 _has_previous_versions = true;
4057 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4058 assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
4059 scratch_class->link_previous_versions(previous_versions());
4060 link_previous_versions(scratch_class);
4061 } // end add_previous_version()
4062
4063 #endif // INCLUDE_JVMTI
4064
4065 Method* InstanceKlass::method_with_idnum(int idnum) {
4066 Method* m = NULL;
4067 if (idnum < methods()->length()) {
4068 m = methods()->at(idnum);
4069 }
4070 if (m == NULL || m->method_idnum() != idnum) {
4071 for (int index = 0; index < methods()->length(); ++index) {
4072 m = methods()->at(index);
4073 if (m->method_idnum() == idnum) {
4074 return m;
4075 }
4076 }
4077 // None found, return null for the caller to handle.
4078 return NULL;
4079 }
4080 return m;
4081 }
4082
4083
4084 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4085 if (idnum >= methods()->length()) {
4086 return NULL;
4087 }
4088 Method* m = methods()->at(idnum);
4089 if (m != NULL && m->orig_method_idnum() == idnum) {
4090 return m;
4091 }
4092 // Obsolete method idnum does not match the original idnum
4093 for (int index = 0; index < methods()->length(); ++index) {
4094 m = methods()->at(index);
4095 if (m->orig_method_idnum() == idnum) {
4096 return m;
4097 }
4098 }
4099 // None found, return null for the caller to handle.
4100 return NULL;
4101 }
4102
4103
4104 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4105 InstanceKlass* holder = get_klass_version(version);
4106 if (holder == NULL) {
4107 return NULL; // The version of klass is gone, no method is found
4108 }
4109 Method* method = holder->method_with_orig_idnum(idnum);
4110 return method;
4111 }
4112
4113 #if INCLUDE_JVMTI
4114 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4115 return _cached_class_file;
4116 }
4117
4118 jint InstanceKlass::get_cached_class_file_len() {
4119 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4120 }
4121
4122 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4123 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4124 }
4125 #endif
4126
4127 #define THROW_DVT_ERROR(s) \
4128 Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IncompatibleClassChangeError(), \
4129 "ValueCapableClass class '%s' %s", external_name(),(s)); \
4130 return