1 /*
2 * Copyright (c) 1997, 2011, 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 "classfile/javaClasses.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/verifier.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "gc_implementation/shared/markSweep.inline.hpp"
32 #include "gc_interface/collectedHeap.inline.hpp"
33 #include "interpreter/oopMapCache.hpp"
34 #include "interpreter/rewriter.hpp"
35 #include "jvmtifiles/jvmti.h"
36 #include "memory/genOopClosures.inline.hpp"
37 #include "memory/oopFactory.hpp"
38 #include "memory/permGen.hpp"
39 #include "oops/instanceKlass.hpp"
40 #include "oops/instanceMirrorKlass.hpp"
41 #include "oops/instanceOop.hpp"
42 #include "oops/methodOop.hpp"
43 #include "oops/objArrayKlassKlass.hpp"
44 #include "oops/oop.inline.hpp"
45 #include "oops/symbol.hpp"
46 #include "prims/jvmtiExport.hpp"
47 #include "prims/jvmtiRedefineClassesTrace.hpp"
48 #include "runtime/fieldDescriptor.hpp"
49 #include "runtime/handles.inline.hpp"
50 #include "runtime/javaCalls.hpp"
51 #include "runtime/mutexLocker.hpp"
52 #include "services/threadService.hpp"
53 #include "utilities/dtrace.hpp"
54 #ifdef TARGET_OS_FAMILY_linux
55 # include "thread_linux.inline.hpp"
56 #endif
57 #ifdef TARGET_OS_FAMILY_solaris
58 # include "thread_solaris.inline.hpp"
59 #endif
60 #ifdef TARGET_OS_FAMILY_windows
61 # include "thread_windows.inline.hpp"
62 #endif
63 #ifndef SERIALGC
64 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
65 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
66 #include "gc_implementation/g1/g1RemSet.inline.hpp"
67 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
68 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
69 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
70 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
71 #include "oops/oop.pcgc.inline.hpp"
72 #endif
73 #ifdef COMPILER1
74 #include "c1/c1_Compiler.hpp"
75 #endif
76
77 #ifdef DTRACE_ENABLED
78
79 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
80 char*, intptr_t, oop, intptr_t);
81 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
82 char*, intptr_t, oop, intptr_t, int);
83 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
84 char*, intptr_t, oop, intptr_t, int);
85 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
86 char*, intptr_t, oop, intptr_t, int);
87 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
88 char*, intptr_t, oop, intptr_t, int);
89 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
90 char*, intptr_t, oop, intptr_t, int);
91 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
92 char*, intptr_t, oop, intptr_t, int);
93 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
94 char*, intptr_t, oop, intptr_t, int);
95
96 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
97 { \
98 char* data = NULL; \
99 int len = 0; \
100 Symbol* name = (clss)->name(); \
101 if (name != NULL) { \
102 data = (char*)name->bytes(); \
103 len = name->utf8_length(); \
104 } \
105 HS_DTRACE_PROBE4(hotspot, class__initialization__##type, \
106 data, len, (clss)->class_loader(), thread_type); \
107 }
108
109 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
110 { \
111 char* data = NULL; \
112 int len = 0; \
113 Symbol* name = (clss)->name(); \
114 if (name != NULL) { \
115 data = (char*)name->bytes(); \
116 len = name->utf8_length(); \
117 } \
118 HS_DTRACE_PROBE5(hotspot, class__initialization__##type, \
119 data, len, (clss)->class_loader(), thread_type, wait); \
120 }
121
122 #else // ndef DTRACE_ENABLED
123
124 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
125 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
126
127 #endif // ndef DTRACE_ENABLED
128
129 bool instanceKlass::should_be_initialized() const {
130 return !is_initialized();
131 }
132
133 klassVtable* instanceKlass::vtable() const {
134 return new klassVtable(as_klassOop(), start_of_vtable(), vtable_length() / vtableEntry::size());
135 }
136
137 klassItable* instanceKlass::itable() const {
138 return new klassItable(as_klassOop());
139 }
140
141 void instanceKlass::eager_initialize(Thread *thread) {
142 if (!EagerInitialization) return;
143
144 if (this->is_not_initialized()) {
145 // abort if the the class has a class initializer
146 if (this->class_initializer() != NULL) return;
147
148 // abort if it is java.lang.Object (initialization is handled in genesis)
149 klassOop super = this->super();
150 if (super == NULL) return;
151
152 // abort if the super class should be initialized
153 if (!instanceKlass::cast(super)->is_initialized()) return;
154
155 // call body to expose the this pointer
156 instanceKlassHandle this_oop(thread, this->as_klassOop());
157 eager_initialize_impl(this_oop);
158 }
159 }
160
161
162 void instanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
163 EXCEPTION_MARK;
164 ObjectLocker ol(this_oop, THREAD);
165
166 // abort if someone beat us to the initialization
167 if (!this_oop->is_not_initialized()) return; // note: not equivalent to is_initialized()
168
169 ClassState old_state = this_oop->_init_state;
170 link_class_impl(this_oop, true, THREAD);
171 if (HAS_PENDING_EXCEPTION) {
172 CLEAR_PENDING_EXCEPTION;
173 // Abort if linking the class throws an exception.
174
175 // Use a test to avoid redundantly resetting the state if there's
176 // no change. Set_init_state() asserts that state changes make
177 // progress, whereas here we might just be spinning in place.
178 if( old_state != this_oop->_init_state )
179 this_oop->set_init_state (old_state);
180 } else {
181 // linking successfull, mark class as initialized
182 this_oop->set_init_state (fully_initialized);
183 // trace
184 if (TraceClassInitialization) {
185 ResourceMark rm(THREAD);
186 tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
187 }
188 }
189 }
190
191
192 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
193 // process. The step comments refers to the procedure described in that section.
194 // Note: implementation moved to static method to expose the this pointer.
195 void instanceKlass::initialize(TRAPS) {
196 if (this->should_be_initialized()) {
197 HandleMark hm(THREAD);
198 instanceKlassHandle this_oop(THREAD, this->as_klassOop());
199 initialize_impl(this_oop, CHECK);
200 // Note: at this point the class may be initialized
201 // OR it may be in the state of being initialized
202 // in case of recursive initialization!
203 } else {
204 assert(is_initialized(), "sanity check");
205 }
206 }
207
208
209 bool instanceKlass::verify_code(
210 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
211 // 1) Verify the bytecodes
212 Verifier::Mode mode =
213 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
214 return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
215 }
216
217
218 // Used exclusively by the shared spaces dump mechanism to prevent
219 // classes mapped into the shared regions in new VMs from appearing linked.
220
221 void instanceKlass::unlink_class() {
222 assert(is_linked(), "must be linked");
223 _init_state = loaded;
224 }
225
226 void instanceKlass::link_class(TRAPS) {
227 assert(is_loaded(), "must be loaded");
228 if (!is_linked()) {
229 instanceKlassHandle this_oop(THREAD, this->as_klassOop());
230 link_class_impl(this_oop, true, CHECK);
231 }
232 }
233
234 // Called to verify that a class can link during initialization, without
235 // throwing a VerifyError.
236 bool instanceKlass::link_class_or_fail(TRAPS) {
237 assert(is_loaded(), "must be loaded");
238 if (!is_linked()) {
239 instanceKlassHandle this_oop(THREAD, this->as_klassOop());
240 link_class_impl(this_oop, false, CHECK_false);
241 }
242 return is_linked();
243 }
244
245 bool instanceKlass::link_class_impl(
246 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
247 // check for error state
248 if (this_oop->is_in_error_state()) {
249 ResourceMark rm(THREAD);
250 THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
251 this_oop->external_name(), false);
252 }
253 // return if already verified
254 if (this_oop->is_linked()) {
255 return true;
256 }
257
258 // Timing
259 // timer handles recursion
260 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
261 JavaThread* jt = (JavaThread*)THREAD;
262
263 // link super class before linking this class
264 instanceKlassHandle super(THREAD, this_oop->super());
265 if (super.not_null()) {
266 if (super->is_interface()) { // check if super class is an interface
267 ResourceMark rm(THREAD);
268 Exceptions::fthrow(
269 THREAD_AND_LOCATION,
270 vmSymbols::java_lang_IncompatibleClassChangeError(),
271 "class %s has interface %s as super class",
272 this_oop->external_name(),
273 super->external_name()
274 );
275 return false;
276 }
277
278 link_class_impl(super, throw_verifyerror, CHECK_false);
279 }
280
281 // link all interfaces implemented by this class before linking this class
282 objArrayHandle interfaces (THREAD, this_oop->local_interfaces());
283 int num_interfaces = interfaces->length();
284 for (int index = 0; index < num_interfaces; index++) {
285 HandleMark hm(THREAD);
286 instanceKlassHandle ih(THREAD, klassOop(interfaces->obj_at(index)));
287 link_class_impl(ih, throw_verifyerror, CHECK_false);
288 }
289
290 // in case the class is linked in the process of linking its superclasses
291 if (this_oop->is_linked()) {
292 return true;
293 }
294
295 // trace only the link time for this klass that includes
296 // the verification time
297 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
298 ClassLoader::perf_class_link_selftime(),
299 ClassLoader::perf_classes_linked(),
300 jt->get_thread_stat()->perf_recursion_counts_addr(),
301 jt->get_thread_stat()->perf_timers_addr(),
302 PerfClassTraceTime::CLASS_LINK);
303
304 // verification & rewriting
305 {
306 ObjectLocker ol(this_oop, THREAD);
307 // rewritten will have been set if loader constraint error found
308 // on an earlier link attempt
309 // don't verify or rewrite if already rewritten
310 if (!this_oop->is_linked()) {
311 if (!this_oop->is_rewritten()) {
312 {
313 // Timer includes any side effects of class verification (resolution,
314 // etc), but not recursive entry into verify_code().
315 PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
316 ClassLoader::perf_class_verify_selftime(),
317 ClassLoader::perf_classes_verified(),
318 jt->get_thread_stat()->perf_recursion_counts_addr(),
319 jt->get_thread_stat()->perf_timers_addr(),
320 PerfClassTraceTime::CLASS_VERIFY);
321 bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
322 if (!verify_ok) {
323 return false;
324 }
325 }
326
327 // Just in case a side-effect of verify linked this class already
328 // (which can sometimes happen since the verifier loads classes
329 // using custom class loaders, which are free to initialize things)
330 if (this_oop->is_linked()) {
331 return true;
332 }
333
334 // also sets rewritten
335 this_oop->rewrite_class(CHECK_false);
336 }
337
338 // relocate jsrs and link methods after they are all rewritten
339 this_oop->relocate_and_link_methods(CHECK_false);
340
341 // Initialize the vtable and interface table after
342 // methods have been rewritten since rewrite may
343 // fabricate new methodOops.
344 // also does loader constraint checking
345 if (!this_oop()->is_shared()) {
346 ResourceMark rm(THREAD);
347 this_oop->vtable()->initialize_vtable(true, CHECK_false);
348 this_oop->itable()->initialize_itable(true, CHECK_false);
349 }
350 #ifdef ASSERT
351 else {
352 ResourceMark rm(THREAD);
353 this_oop->vtable()->verify(tty, true);
354 // In case itable verification is ever added.
355 // this_oop->itable()->verify(tty, true);
356 }
357 #endif
358 this_oop->set_init_state(linked);
359 if (JvmtiExport::should_post_class_prepare()) {
360 Thread *thread = THREAD;
361 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
362 JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
363 }
364 }
365 }
366 return true;
367 }
368
369
370 // Rewrite the byte codes of all of the methods of a class.
371 // The rewriter must be called exactly once. Rewriting must happen after
372 // verification but before the first method of the class is executed.
373 void instanceKlass::rewrite_class(TRAPS) {
374 assert(is_loaded(), "must be loaded");
375 instanceKlassHandle this_oop(THREAD, this->as_klassOop());
376 if (this_oop->is_rewritten()) {
377 assert(this_oop()->is_shared(), "rewriting an unshared class?");
378 return;
379 }
380 Rewriter::rewrite(this_oop, CHECK);
381 this_oop->set_rewritten();
382 }
383
384 // Now relocate and link method entry points after class is rewritten.
385 // This is outside is_rewritten flag. In case of an exception, it can be
386 // executed more than once.
387 void instanceKlass::relocate_and_link_methods(TRAPS) {
388 assert(is_loaded(), "must be loaded");
389 instanceKlassHandle this_oop(THREAD, this->as_klassOop());
390 Rewriter::relocate_and_link(this_oop, CHECK);
391 }
392
393
394 void instanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
395 // Make sure klass is linked (verified) before initialization
396 // A class could already be verified, since it has been reflected upon.
397 this_oop->link_class(CHECK);
398
399 DTRACE_CLASSINIT_PROBE(required, instanceKlass::cast(this_oop()), -1);
400
401 bool wait = false;
402
403 // refer to the JVM book page 47 for description of steps
404 // Step 1
405 { ObjectLocker ol(this_oop, THREAD);
406
407 Thread *self = THREAD; // it's passed the current thread
408
409 // Step 2
410 // If we were to use wait() instead of waitInterruptibly() then
411 // we might end up throwing IE from link/symbol resolution sites
412 // that aren't expected to throw. This would wreak havoc. See 6320309.
413 while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
414 wait = true;
415 ol.waitUninterruptibly(CHECK);
416 }
417
418 // Step 3
419 if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
420 DTRACE_CLASSINIT_PROBE_WAIT(recursive, instanceKlass::cast(this_oop()), -1,wait);
421 return;
422 }
423
424 // Step 4
425 if (this_oop->is_initialized()) {
426 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, instanceKlass::cast(this_oop()), -1,wait);
427 return;
428 }
429
430 // Step 5
431 if (this_oop->is_in_error_state()) {
432 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, instanceKlass::cast(this_oop()), -1,wait);
433 ResourceMark rm(THREAD);
434 const char* desc = "Could not initialize class ";
435 const char* className = this_oop->external_name();
436 size_t msglen = strlen(desc) + strlen(className) + 1;
437 char* message = NEW_RESOURCE_ARRAY(char, msglen);
438 if (NULL == message) {
439 // Out of memory: can't create detailed error message
440 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
441 } else {
442 jio_snprintf(message, msglen, "%s%s", desc, className);
443 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
444 }
445 }
446
447 // Step 6
448 this_oop->set_init_state(being_initialized);
449 this_oop->set_init_thread(self);
450 }
451
452 // Step 7
453 klassOop super_klass = this_oop->super();
454 if (super_klass != NULL && !this_oop->is_interface() && Klass::cast(super_klass)->should_be_initialized()) {
455 Klass::cast(super_klass)->initialize(THREAD);
456
457 if (HAS_PENDING_EXCEPTION) {
458 Handle e(THREAD, PENDING_EXCEPTION);
459 CLEAR_PENDING_EXCEPTION;
460 {
461 EXCEPTION_MARK;
462 this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
463 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, superclass initialization error is thrown below
464 }
465 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, instanceKlass::cast(this_oop()), -1,wait);
466 THROW_OOP(e());
467 }
468 }
469
470 // Step 8
471 {
472 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
473 JavaThread* jt = (JavaThread*)THREAD;
474 DTRACE_CLASSINIT_PROBE_WAIT(clinit, instanceKlass::cast(this_oop()), -1,wait);
475 // Timer includes any side effects of class initialization (resolution,
476 // etc), but not recursive entry into call_class_initializer().
477 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
478 ClassLoader::perf_class_init_selftime(),
479 ClassLoader::perf_classes_inited(),
480 jt->get_thread_stat()->perf_recursion_counts_addr(),
481 jt->get_thread_stat()->perf_timers_addr(),
482 PerfClassTraceTime::CLASS_CLINIT);
483 this_oop->call_class_initializer(THREAD);
484 }
485
486 // Step 9
487 if (!HAS_PENDING_EXCEPTION) {
488 this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
489 { ResourceMark rm(THREAD);
490 debug_only(this_oop->vtable()->verify(tty, true);)
491 }
492 }
493 else {
494 // Step 10 and 11
495 Handle e(THREAD, PENDING_EXCEPTION);
496 CLEAR_PENDING_EXCEPTION;
497 {
498 EXCEPTION_MARK;
499 this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
500 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
501 }
502 DTRACE_CLASSINIT_PROBE_WAIT(error, instanceKlass::cast(this_oop()), -1,wait);
503 if (e->is_a(SystemDictionary::Error_klass())) {
504 THROW_OOP(e());
505 } else {
506 JavaCallArguments args(e);
507 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
508 vmSymbols::throwable_void_signature(),
509 &args);
510 }
511 }
512 DTRACE_CLASSINIT_PROBE_WAIT(end, instanceKlass::cast(this_oop()), -1,wait);
513 }
514
515
516 // Note: implementation moved to static method to expose the this pointer.
517 void instanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
518 instanceKlassHandle kh(THREAD, this->as_klassOop());
519 set_initialization_state_and_notify_impl(kh, state, CHECK);
520 }
521
522 void instanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
523 ObjectLocker ol(this_oop, THREAD);
524 this_oop->set_init_state(state);
525 ol.notify_all(CHECK);
526 }
527
528 void instanceKlass::add_implementor(klassOop k) {
529 assert(Compile_lock->owned_by_self(), "");
530 // Filter out my subinterfaces.
531 // (Note: Interfaces are never on the subklass list.)
532 if (instanceKlass::cast(k)->is_interface()) return;
533
534 // Filter out subclasses whose supers already implement me.
535 // (Note: CHA must walk subclasses of direct implementors
536 // in order to locate indirect implementors.)
537 klassOop sk = instanceKlass::cast(k)->super();
538 if (sk != NULL && instanceKlass::cast(sk)->implements_interface(as_klassOop()))
539 // We only need to check one immediate superclass, since the
540 // implements_interface query looks at transitive_interfaces.
541 // Any supers of the super have the same (or fewer) transitive_interfaces.
542 return;
543
544 // Update number of implementors
545 int i = _nof_implementors++;
546
547 // Record this implementor, if there are not too many already
548 if (i < implementors_limit) {
549 assert(_implementors[i] == NULL, "should be exactly one implementor");
550 oop_store_without_check((oop*)&_implementors[i], k);
551 } else if (i == implementors_limit) {
552 // clear out the list on first overflow
553 for (int i2 = 0; i2 < implementors_limit; i2++)
554 oop_store_without_check((oop*)&_implementors[i2], NULL);
555 }
556
557 // The implementor also implements the transitive_interfaces
558 for (int index = 0; index < local_interfaces()->length(); index++) {
559 instanceKlass::cast(klassOop(local_interfaces()->obj_at(index)))->add_implementor(k);
560 }
561 }
562
563 void instanceKlass::init_implementor() {
564 for (int i = 0; i < implementors_limit; i++)
565 oop_store_without_check((oop*)&_implementors[i], NULL);
566 _nof_implementors = 0;
567 }
568
569
570 void instanceKlass::process_interfaces(Thread *thread) {
571 // link this class into the implementors list of every interface it implements
572 KlassHandle this_as_oop (thread, this->as_klassOop());
573 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
574 assert(local_interfaces()->obj_at(i)->is_klass(), "must be a klass");
575 instanceKlass* interf = instanceKlass::cast(klassOop(local_interfaces()->obj_at(i)));
576 assert(interf->is_interface(), "expected interface");
577 interf->add_implementor(this_as_oop());
578 }
579 }
580
581 bool instanceKlass::can_be_primary_super_slow() const {
582 if (is_interface())
583 return false;
584 else
585 return Klass::can_be_primary_super_slow();
586 }
587
588 objArrayOop instanceKlass::compute_secondary_supers(int num_extra_slots, TRAPS) {
589 // The secondaries are the implemented interfaces.
590 instanceKlass* ik = instanceKlass::cast(as_klassOop());
591 objArrayHandle interfaces (THREAD, ik->transitive_interfaces());
592 int num_secondaries = num_extra_slots + interfaces->length();
593 if (num_secondaries == 0) {
594 return Universe::the_empty_system_obj_array();
595 } else if (num_extra_slots == 0) {
596 return interfaces();
597 } else {
598 // a mix of both
599 objArrayOop secondaries = oopFactory::new_system_objArray(num_secondaries, CHECK_NULL);
600 for (int i = 0; i < interfaces->length(); i++) {
601 secondaries->obj_at_put(num_extra_slots+i, interfaces->obj_at(i));
602 }
603 return secondaries;
604 }
605 }
606
607 bool instanceKlass::compute_is_subtype_of(klassOop k) {
608 if (Klass::cast(k)->is_interface()) {
609 return implements_interface(k);
610 } else {
611 return Klass::compute_is_subtype_of(k);
612 }
613 }
614
615 bool instanceKlass::implements_interface(klassOop k) const {
616 if (as_klassOop() == k) return true;
617 assert(Klass::cast(k)->is_interface(), "should be an interface class");
618 for (int i = 0; i < transitive_interfaces()->length(); i++) {
619 if (transitive_interfaces()->obj_at(i) == k) {
620 return true;
621 }
622 }
623 return false;
624 }
625
626 objArrayOop instanceKlass::allocate_objArray(int n, int length, TRAPS) {
627 if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
628 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
629 report_java_out_of_memory("Requested array size exceeds VM limit");
630 THROW_OOP_0(Universe::out_of_memory_error_array_size());
631 }
632 int size = objArrayOopDesc::object_size(length);
633 klassOop ak = array_klass(n, CHECK_NULL);
634 KlassHandle h_ak (THREAD, ak);
635 objArrayOop o =
636 (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
637 return o;
638 }
639
640 instanceOop instanceKlass::register_finalizer(instanceOop i, TRAPS) {
641 if (TraceFinalizerRegistration) {
642 tty->print("Registered ");
643 i->print_value_on(tty);
644 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
645 }
646 instanceHandle h_i(THREAD, i);
647 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
648 JavaValue result(T_VOID);
649 JavaCallArguments args(h_i);
650 methodHandle mh (THREAD, Universe::finalizer_register_method());
651 JavaCalls::call(&result, mh, &args, CHECK_NULL);
652 return h_i();
653 }
654
655 instanceOop instanceKlass::allocate_instance(TRAPS) {
656 assert(!oop_is_instanceMirror(), "wrong allocation path");
657 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
658 int size = size_helper(); // Query before forming handle.
659
660 KlassHandle h_k(THREAD, as_klassOop());
661
662 instanceOop i;
663
664 i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
665 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
666 i = register_finalizer(i, CHECK_NULL);
667 }
668 return i;
669 }
670
671 instanceOop instanceKlass::allocate_permanent_instance(TRAPS) {
672 // Finalizer registration occurs in the Object.<init> constructor
673 // and constructors normally aren't run when allocating perm
674 // instances so simply disallow finalizable perm objects. This can
675 // be relaxed if a need for it is found.
676 assert(!has_finalizer(), "perm objects not allowed to have finalizers");
677 assert(!oop_is_instanceMirror(), "wrong allocation path");
678 int size = size_helper(); // Query before forming handle.
679 KlassHandle h_k(THREAD, as_klassOop());
680 instanceOop i = (instanceOop)
681 CollectedHeap::permanent_obj_allocate(h_k, size, CHECK_NULL);
682 return i;
683 }
684
685 void instanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
686 if (is_interface() || is_abstract()) {
687 ResourceMark rm(THREAD);
688 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
689 : vmSymbols::java_lang_InstantiationException(), external_name());
690 }
691 if (as_klassOop() == SystemDictionary::Class_klass()) {
692 ResourceMark rm(THREAD);
693 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
694 : vmSymbols::java_lang_IllegalAccessException(), external_name());
695 }
696 }
697
698 klassOop instanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
699 instanceKlassHandle this_oop(THREAD, as_klassOop());
700 return array_klass_impl(this_oop, or_null, n, THREAD);
701 }
702
703 klassOop instanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
704 if (this_oop->array_klasses() == NULL) {
705 if (or_null) return NULL;
706
707 ResourceMark rm;
708 JavaThread *jt = (JavaThread *)THREAD;
709 {
710 // Atomic creation of array_klasses
711 MutexLocker mc(Compile_lock, THREAD); // for vtables
712 MutexLocker ma(MultiArray_lock, THREAD);
713
714 // Check if update has already taken place
715 if (this_oop->array_klasses() == NULL) {
716 objArrayKlassKlass* oakk =
717 (objArrayKlassKlass*)Universe::objArrayKlassKlassObj()->klass_part();
718
719 klassOop k = oakk->allocate_objArray_klass(1, this_oop, CHECK_NULL);
720 this_oop->set_array_klasses(k);
721 }
722 }
723 }
724 // _this will always be set at this point
725 objArrayKlass* oak = (objArrayKlass*)this_oop->array_klasses()->klass_part();
726 if (or_null) {
727 return oak->array_klass_or_null(n);
728 }
729 return oak->array_klass(n, CHECK_NULL);
730 }
731
732 klassOop instanceKlass::array_klass_impl(bool or_null, TRAPS) {
733 return array_klass_impl(or_null, 1, THREAD);
734 }
735
736 void instanceKlass::call_class_initializer(TRAPS) {
737 instanceKlassHandle ik (THREAD, as_klassOop());
738 call_class_initializer_impl(ik, THREAD);
739 }
740
741 static int call_class_initializer_impl_counter = 0; // for debugging
742
743 methodOop instanceKlass::class_initializer() {
744 methodOop clinit = find_method(
745 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
746 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
747 return clinit;
748 }
749 return NULL;
750 }
751
752 void instanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
753 methodHandle h_method(THREAD, this_oop->class_initializer());
754 assert(!this_oop->is_initialized(), "we cannot initialize twice");
755 if (TraceClassInitialization) {
756 tty->print("%d Initializing ", call_class_initializer_impl_counter++);
757 this_oop->name()->print_value();
758 tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
759 }
760 if (h_method() != NULL) {
761 JavaCallArguments args; // No arguments
762 JavaValue result(T_VOID);
763 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
764 }
765 }
766
767
768 void instanceKlass::mask_for(methodHandle method, int bci,
769 InterpreterOopMap* entry_for) {
770 // Dirty read, then double-check under a lock.
771 if (_oop_map_cache == NULL) {
772 // Otherwise, allocate a new one.
773 MutexLocker x(OopMapCacheAlloc_lock);
774 // First time use. Allocate a cache in C heap
775 if (_oop_map_cache == NULL) {
776 _oop_map_cache = new OopMapCache();
777 }
778 }
779 // _oop_map_cache is constant after init; lookup below does is own locking.
780 _oop_map_cache->lookup(method, bci, entry_for);
781 }
782
783
784 bool instanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
785 const int n = fields()->length();
786 for (int i = 0; i < n; i += next_offset ) {
787 int name_index = fields()->ushort_at(i + name_index_offset);
788 int sig_index = fields()->ushort_at(i + signature_index_offset);
789 Symbol* f_name = constants()->symbol_at(name_index);
790 Symbol* f_sig = constants()->symbol_at(sig_index);
791 if (f_name == name && f_sig == sig) {
792 fd->initialize(as_klassOop(), i);
793 return true;
794 }
795 }
796 return false;
797 }
798
799
800 void instanceKlass::shared_symbols_iterate(SymbolClosure* closure) {
801 Klass::shared_symbols_iterate(closure);
802 closure->do_symbol(&_generic_signature);
803 closure->do_symbol(&_source_file_name);
804 closure->do_symbol(&_source_debug_extension);
805
806 const int n = fields()->length();
807 for (int i = 0; i < n; i += next_offset ) {
808 int name_index = fields()->ushort_at(i + name_index_offset);
809 closure->do_symbol(constants()->symbol_at_addr(name_index));
810 int sig_index = fields()->ushort_at(i + signature_index_offset);
811 closure->do_symbol(constants()->symbol_at_addr(sig_index));
812 }
813 }
814
815
816 klassOop instanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
817 const int n = local_interfaces()->length();
818 for (int i = 0; i < n; i++) {
819 klassOop intf1 = klassOop(local_interfaces()->obj_at(i));
820 assert(Klass::cast(intf1)->is_interface(), "just checking type");
821 // search for field in current interface
822 if (instanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
823 assert(fd->is_static(), "interface field must be static");
824 return intf1;
825 }
826 // search for field in direct superinterfaces
827 klassOop intf2 = instanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
828 if (intf2 != NULL) return intf2;
829 }
830 // otherwise field lookup fails
831 return NULL;
832 }
833
834
835 klassOop instanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
836 // search order according to newest JVM spec (5.4.3.2, p.167).
837 // 1) search for field in current klass
838 if (find_local_field(name, sig, fd)) {
839 return as_klassOop();
840 }
841 // 2) search for field recursively in direct superinterfaces
842 { klassOop intf = find_interface_field(name, sig, fd);
843 if (intf != NULL) return intf;
844 }
845 // 3) apply field lookup recursively if superclass exists
846 { klassOop supr = super();
847 if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, fd);
848 }
849 // 4) otherwise field lookup fails
850 return NULL;
851 }
852
853
854 klassOop instanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
855 // search order according to newest JVM spec (5.4.3.2, p.167).
856 // 1) search for field in current klass
857 if (find_local_field(name, sig, fd)) {
858 if (fd->is_static() == is_static) return as_klassOop();
859 }
860 // 2) search for field recursively in direct superinterfaces
861 if (is_static) {
862 klassOop intf = find_interface_field(name, sig, fd);
863 if (intf != NULL) return intf;
864 }
865 // 3) apply field lookup recursively if superclass exists
866 { klassOop supr = super();
867 if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
868 }
869 // 4) otherwise field lookup fails
870 return NULL;
871 }
872
873
874 bool instanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
875 int length = fields()->length();
876 for (int i = 0; i < length; i += next_offset) {
877 if (offset_from_fields( i ) == offset) {
878 fd->initialize(as_klassOop(), i);
879 if (fd->is_static() == is_static) return true;
880 }
881 }
882 return false;
883 }
884
885
886 bool instanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
887 klassOop klass = as_klassOop();
888 while (klass != NULL) {
889 if (instanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
890 return true;
891 }
892 klass = Klass::cast(klass)->super();
893 }
894 return false;
895 }
896
897
898 void instanceKlass::methods_do(void f(methodOop method)) {
899 int len = methods()->length();
900 for (int index = 0; index < len; index++) {
901 methodOop m = methodOop(methods()->obj_at(index));
902 assert(m->is_method(), "must be method");
903 f(m);
904 }
905 }
906
907
908 void instanceKlass::do_local_static_fields(FieldClosure* cl) {
909 fieldDescriptor fd;
910 int length = fields()->length();
911 for (int i = 0; i < length; i += next_offset) {
912 fd.initialize(as_klassOop(), i);
913 if (fd.is_static()) cl->do_field(&fd);
914 }
915 }
916
917
918 void instanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
919 instanceKlassHandle h_this(THREAD, as_klassOop());
920 do_local_static_fields_impl(h_this, f, CHECK);
921 }
922
923
924 void instanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
925 fieldDescriptor fd;
926 int length = this_oop->fields()->length();
927 for (int i = 0; i < length; i += next_offset) {
928 fd.initialize(this_oop(), i);
929 if (fd.is_static()) { f(&fd, CHECK); } // Do NOT remove {}! (CHECK macro expands into several statements)
930 }
931 }
932
933
934 static int compare_fields_by_offset(int* a, int* b) {
935 return a[0] - b[0];
936 }
937
938 void instanceKlass::do_nonstatic_fields(FieldClosure* cl) {
939 instanceKlass* super = superklass();
940 if (super != NULL) {
941 super->do_nonstatic_fields(cl);
942 }
943 fieldDescriptor fd;
944 int length = fields()->length();
945 // In DebugInfo nonstatic fields are sorted by offset.
946 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1));
947 int j = 0;
948 for (int i = 0; i < length; i += next_offset) {
949 fd.initialize(as_klassOop(), i);
950 if (!fd.is_static()) {
951 fields_sorted[j + 0] = fd.offset();
952 fields_sorted[j + 1] = i;
953 j += 2;
954 }
955 }
956 if (j > 0) {
957 length = j;
958 // _sort_Fn is defined in growableArray.hpp.
959 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
960 for (int i = 0; i < length; i += 2) {
961 fd.initialize(as_klassOop(), fields_sorted[i + 1]);
962 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
963 cl->do_field(&fd);
964 }
965 }
966 FREE_C_HEAP_ARRAY(int, fields_sorted);
967 }
968
969
970 void instanceKlass::array_klasses_do(void f(klassOop k)) {
971 if (array_klasses() != NULL)
972 arrayKlass::cast(array_klasses())->array_klasses_do(f);
973 }
974
975
976 void instanceKlass::with_array_klasses_do(void f(klassOop k)) {
977 f(as_klassOop());
978 array_klasses_do(f);
979 }
980
981 #ifdef ASSERT
982 static int linear_search(objArrayOop methods, Symbol* name, Symbol* signature) {
983 int len = methods->length();
984 for (int index = 0; index < len; index++) {
985 methodOop m = (methodOop)(methods->obj_at(index));
986 assert(m->is_method(), "must be method");
987 if (m->signature() == signature && m->name() == name) {
988 return index;
989 }
990 }
991 return -1;
992 }
993 #endif
994
995 methodOop instanceKlass::find_method(Symbol* name, Symbol* signature) const {
996 return instanceKlass::find_method(methods(), name, signature);
997 }
998
999 methodOop instanceKlass::find_method(objArrayOop methods, Symbol* name, Symbol* signature) {
1000 int len = methods->length();
1001 // methods are sorted, so do binary search
1002 int l = 0;
1003 int h = len - 1;
1004 while (l <= h) {
1005 int mid = (l + h) >> 1;
1006 methodOop m = (methodOop)methods->obj_at(mid);
1007 assert(m->is_method(), "must be method");
1008 int res = m->name()->fast_compare(name);
1009 if (res == 0) {
1010 // found matching name; do linear search to find matching signature
1011 // first, quick check for common case
1012 if (m->signature() == signature) return m;
1013 // search downwards through overloaded methods
1014 int i;
1015 for (i = mid - 1; i >= l; i--) {
1016 methodOop m = (methodOop)methods->obj_at(i);
1017 assert(m->is_method(), "must be method");
1018 if (m->name() != name) break;
1019 if (m->signature() == signature) return m;
1020 }
1021 // search upwards
1022 for (i = mid + 1; i <= h; i++) {
1023 methodOop m = (methodOop)methods->obj_at(i);
1024 assert(m->is_method(), "must be method");
1025 if (m->name() != name) break;
1026 if (m->signature() == signature) return m;
1027 }
1028 // not found
1029 #ifdef ASSERT
1030 int index = linear_search(methods, name, signature);
1031 assert(index == -1, err_msg("binary search should have found entry %d", index));
1032 #endif
1033 return NULL;
1034 } else if (res < 0) {
1035 l = mid + 1;
1036 } else {
1037 h = mid - 1;
1038 }
1039 }
1040 #ifdef ASSERT
1041 int index = linear_search(methods, name, signature);
1042 assert(index == -1, err_msg("binary search should have found entry %d", index));
1043 #endif
1044 return NULL;
1045 }
1046
1047 methodOop instanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
1048 klassOop klass = as_klassOop();
1049 while (klass != NULL) {
1050 methodOop method = instanceKlass::cast(klass)->find_method(name, signature);
1051 if (method != NULL) return method;
1052 klass = instanceKlass::cast(klass)->super();
1053 }
1054 return NULL;
1055 }
1056
1057 // lookup a method in all the interfaces that this class implements
1058 methodOop instanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1059 Symbol* signature) const {
1060 objArrayOop all_ifs = instanceKlass::cast(as_klassOop())->transitive_interfaces();
1061 int num_ifs = all_ifs->length();
1062 instanceKlass *ik = NULL;
1063 for (int i = 0; i < num_ifs; i++) {
1064 ik = instanceKlass::cast(klassOop(all_ifs->obj_at(i)));
1065 methodOop m = ik->lookup_method(name, signature);
1066 if (m != NULL) {
1067 return m;
1068 }
1069 }
1070 return NULL;
1071 }
1072
1073 /* jni_id_for_impl for jfieldIds only */
1074 JNIid* instanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
1075 MutexLocker ml(JfieldIdCreation_lock);
1076 // Retry lookup after we got the lock
1077 JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
1078 if (probe == NULL) {
1079 // Slow case, allocate new static field identifier
1080 probe = new JNIid(this_oop->as_klassOop(), offset, this_oop->jni_ids());
1081 this_oop->set_jni_ids(probe);
1082 }
1083 return probe;
1084 }
1085
1086
1087 /* jni_id_for for jfieldIds only */
1088 JNIid* instanceKlass::jni_id_for(int offset) {
1089 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1090 if (probe == NULL) {
1091 probe = jni_id_for_impl(this->as_klassOop(), offset);
1092 }
1093 return probe;
1094 }
1095
1096
1097 // Lookup or create a jmethodID.
1098 // This code is called by the VMThread and JavaThreads so the
1099 // locking has to be done very carefully to avoid deadlocks
1100 // and/or other cache consistency problems.
1101 //
1102 jmethodID instanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1103 size_t idnum = (size_t)method_h->method_idnum();
1104 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1105 size_t length = 0;
1106 jmethodID id = NULL;
1107
1108 // We use a double-check locking idiom here because this cache is
1109 // performance sensitive. In the normal system, this cache only
1110 // transitions from NULL to non-NULL which is safe because we use
1111 // release_set_methods_jmethod_ids() to advertise the new cache.
1112 // A partially constructed cache should never be seen by a racing
1113 // thread. We also use release_store_ptr() to save a new jmethodID
1114 // in the cache so a partially constructed jmethodID should never be
1115 // seen either. Cache reads of existing jmethodIDs proceed without a
1116 // lock, but cache writes of a new jmethodID requires uniqueness and
1117 // creation of the cache itself requires no leaks so a lock is
1118 // generally acquired in those two cases.
1119 //
1120 // If the RedefineClasses() API has been used, then this cache can
1121 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1122 // Cache creation requires no leaks and we require safety between all
1123 // cache accesses and freeing of the old cache so a lock is generally
1124 // acquired when the RedefineClasses() API has been used.
1125
1126 if (jmeths != NULL) {
1127 // the cache already exists
1128 if (!ik_h->idnum_can_increment()) {
1129 // the cache can't grow so we can just get the current values
1130 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1131 } else {
1132 // cache can grow so we have to be more careful
1133 if (Threads::number_of_threads() == 0 ||
1134 SafepointSynchronize::is_at_safepoint()) {
1135 // we're single threaded or at a safepoint - no locking needed
1136 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1137 } else {
1138 MutexLocker ml(JmethodIdCreation_lock);
1139 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1140 }
1141 }
1142 }
1143 // implied else:
1144 // we need to allocate a cache so default length and id values are good
1145
1146 if (jmeths == NULL || // no cache yet
1147 length <= idnum || // cache is too short
1148 id == NULL) { // cache doesn't contain entry
1149
1150 // This function can be called by the VMThread so we have to do all
1151 // things that might block on a safepoint before grabbing the lock.
1152 // Otherwise, we can deadlock with the VMThread or have a cache
1153 // consistency issue. These vars keep track of what we might have
1154 // to free after the lock is dropped.
1155 jmethodID to_dealloc_id = NULL;
1156 jmethodID* to_dealloc_jmeths = NULL;
1157
1158 // may not allocate new_jmeths or use it if we allocate it
1159 jmethodID* new_jmeths = NULL;
1160 if (length <= idnum) {
1161 // allocate a new cache that might be used
1162 size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1163 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1);
1164 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1165 // cache size is stored in element[0], other elements offset by one
1166 new_jmeths[0] = (jmethodID)size;
1167 }
1168
1169 // allocate a new jmethodID that might be used
1170 jmethodID new_id = NULL;
1171 if (method_h->is_old() && !method_h->is_obsolete()) {
1172 // The method passed in is old (but not obsolete), we need to use the current version
1173 methodOop current_method = ik_h->method_with_idnum((int)idnum);
1174 assert(current_method != NULL, "old and but not obsolete, so should exist");
1175 methodHandle current_method_h(current_method == NULL? method_h() : current_method);
1176 new_id = JNIHandles::make_jmethod_id(current_method_h);
1177 } else {
1178 // It is the current version of the method or an obsolete method,
1179 // use the version passed in
1180 new_id = JNIHandles::make_jmethod_id(method_h);
1181 }
1182
1183 if (Threads::number_of_threads() == 0 ||
1184 SafepointSynchronize::is_at_safepoint()) {
1185 // we're single threaded or at a safepoint - no locking needed
1186 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1187 &to_dealloc_id, &to_dealloc_jmeths);
1188 } else {
1189 MutexLocker ml(JmethodIdCreation_lock);
1190 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1191 &to_dealloc_id, &to_dealloc_jmeths);
1192 }
1193
1194 // The lock has been dropped so we can free resources.
1195 // Free up either the old cache or the new cache if we allocated one.
1196 if (to_dealloc_jmeths != NULL) {
1197 FreeHeap(to_dealloc_jmeths);
1198 }
1199 // free up the new ID since it wasn't needed
1200 if (to_dealloc_id != NULL) {
1201 JNIHandles::destroy_jmethod_id(to_dealloc_id);
1202 }
1203 }
1204 return id;
1205 }
1206
1207
1208 // Common code to fetch the jmethodID from the cache or update the
1209 // cache with the new jmethodID. This function should never do anything
1210 // that causes the caller to go to a safepoint or we can deadlock with
1211 // the VMThread or have cache consistency issues.
1212 //
1213 jmethodID instanceKlass::get_jmethod_id_fetch_or_update(
1214 instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1215 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1216 jmethodID** to_dealloc_jmeths_p) {
1217 assert(new_id != NULL, "sanity check");
1218 assert(to_dealloc_id_p != NULL, "sanity check");
1219 assert(to_dealloc_jmeths_p != NULL, "sanity check");
1220 assert(Threads::number_of_threads() == 0 ||
1221 SafepointSynchronize::is_at_safepoint() ||
1222 JmethodIdCreation_lock->owned_by_self(), "sanity check");
1223
1224 // reacquire the cache - we are locked, single threaded or at a safepoint
1225 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1226 jmethodID id = NULL;
1227 size_t length = 0;
1228
1229 if (jmeths == NULL || // no cache yet
1230 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
1231 if (jmeths != NULL) {
1232 // copy any existing entries from the old cache
1233 for (size_t index = 0; index < length; index++) {
1234 new_jmeths[index+1] = jmeths[index+1];
1235 }
1236 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
1237 }
1238 ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1239 } else {
1240 // fetch jmethodID (if any) from the existing cache
1241 id = jmeths[idnum+1];
1242 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
1243 }
1244 if (id == NULL) {
1245 // No matching jmethodID in the existing cache or we have a new
1246 // cache or we just grew the cache. This cache write is done here
1247 // by the first thread to win the foot race because a jmethodID
1248 // needs to be unique once it is generally available.
1249 id = new_id;
1250
1251 // The jmethodID cache can be read while unlocked so we have to
1252 // make sure the new jmethodID is complete before installing it
1253 // in the cache.
1254 OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1255 } else {
1256 *to_dealloc_id_p = new_id; // save new id for later delete
1257 }
1258 return id;
1259 }
1260
1261
1262 // Common code to get the jmethodID cache length and the jmethodID
1263 // value at index idnum if there is one.
1264 //
1265 void instanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1266 size_t idnum, size_t *length_p, jmethodID* id_p) {
1267 assert(cache != NULL, "sanity check");
1268 assert(length_p != NULL, "sanity check");
1269 assert(id_p != NULL, "sanity check");
1270
1271 // cache size is stored in element[0], other elements offset by one
1272 *length_p = (size_t)cache[0];
1273 if (*length_p <= idnum) { // cache is too short
1274 *id_p = NULL;
1275 } else {
1276 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
1277 }
1278 }
1279
1280
1281 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
1282 jmethodID instanceKlass::jmethod_id_or_null(methodOop method) {
1283 size_t idnum = (size_t)method->method_idnum();
1284 jmethodID* jmeths = methods_jmethod_ids_acquire();
1285 size_t length; // length assigned as debugging crumb
1286 jmethodID id = NULL;
1287 if (jmeths != NULL && // If there is a cache
1288 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
1289 id = jmeths[idnum+1]; // Look up the id (may be NULL)
1290 }
1291 return id;
1292 }
1293
1294
1295 // Cache an itable index
1296 void instanceKlass::set_cached_itable_index(size_t idnum, int index) {
1297 int* indices = methods_cached_itable_indices_acquire();
1298 int* to_dealloc_indices = NULL;
1299
1300 // We use a double-check locking idiom here because this cache is
1301 // performance sensitive. In the normal system, this cache only
1302 // transitions from NULL to non-NULL which is safe because we use
1303 // release_set_methods_cached_itable_indices() to advertise the
1304 // new cache. A partially constructed cache should never be seen
1305 // by a racing thread. Cache reads and writes proceed without a
1306 // lock, but creation of the cache itself requires no leaks so a
1307 // lock is generally acquired in that case.
1308 //
1309 // If the RedefineClasses() API has been used, then this cache can
1310 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1311 // Cache creation requires no leaks and we require safety between all
1312 // cache accesses and freeing of the old cache so a lock is generally
1313 // acquired when the RedefineClasses() API has been used.
1314
1315 if (indices == NULL || idnum_can_increment()) {
1316 // we need a cache or the cache can grow
1317 MutexLocker ml(JNICachedItableIndex_lock);
1318 // reacquire the cache to see if another thread already did the work
1319 indices = methods_cached_itable_indices_acquire();
1320 size_t length = 0;
1321 // cache size is stored in element[0], other elements offset by one
1322 if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
1323 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1324 int* new_indices = NEW_C_HEAP_ARRAY(int, size+1);
1325 new_indices[0] = (int)size;
1326 // copy any existing entries
1327 size_t i;
1328 for (i = 0; i < length; i++) {
1329 new_indices[i+1] = indices[i+1];
1330 }
1331 // Set all the rest to -1
1332 for (i = length; i < size; i++) {
1333 new_indices[i+1] = -1;
1334 }
1335 if (indices != NULL) {
1336 // We have an old cache to delete so save it for after we
1337 // drop the lock.
1338 to_dealloc_indices = indices;
1339 }
1340 release_set_methods_cached_itable_indices(indices = new_indices);
1341 }
1342
1343 if (idnum_can_increment()) {
1344 // this cache can grow so we have to write to it safely
1345 indices[idnum+1] = index;
1346 }
1347 } else {
1348 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
1349 }
1350
1351 if (!idnum_can_increment()) {
1352 // The cache cannot grow and this JNI itable index value does not
1353 // have to be unique like a jmethodID. If there is a race to set it,
1354 // it doesn't matter.
1355 indices[idnum+1] = index;
1356 }
1357
1358 if (to_dealloc_indices != NULL) {
1359 // we allocated a new cache so free the old one
1360 FreeHeap(to_dealloc_indices);
1361 }
1362 }
1363
1364
1365 // Retrieve a cached itable index
1366 int instanceKlass::cached_itable_index(size_t idnum) {
1367 int* indices = methods_cached_itable_indices_acquire();
1368 if (indices != NULL && ((size_t)indices[0]) > idnum) {
1369 // indices exist and are long enough, retrieve possible cached
1370 return indices[idnum+1];
1371 }
1372 return -1;
1373 }
1374
1375
1376 //
1377 // Walk the list of dependent nmethods searching for nmethods which
1378 // are dependent on the changes that were passed in and mark them for
1379 // deoptimization. Returns the number of nmethods found.
1380 //
1381 int instanceKlass::mark_dependent_nmethods(DepChange& changes) {
1382 assert_locked_or_safepoint(CodeCache_lock);
1383 int found = 0;
1384 nmethodBucket* b = _dependencies;
1385 while (b != NULL) {
1386 nmethod* nm = b->get_nmethod();
1387 // since dependencies aren't removed until an nmethod becomes a zombie,
1388 // the dependency list may contain nmethods which aren't alive.
1389 if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1390 if (TraceDependencies) {
1391 ResourceMark rm;
1392 tty->print_cr("Marked for deoptimization");
1393 tty->print_cr(" context = %s", this->external_name());
1394 changes.print();
1395 nm->print();
1396 nm->print_dependencies();
1397 }
1398 nm->mark_for_deoptimization();
1399 found++;
1400 }
1401 b = b->next();
1402 }
1403 return found;
1404 }
1405
1406
1407 //
1408 // Add an nmethodBucket to the list of dependencies for this nmethod.
1409 // It's possible that an nmethod has multiple dependencies on this klass
1410 // so a count is kept for each bucket to guarantee that creation and
1411 // deletion of dependencies is consistent.
1412 //
1413 void instanceKlass::add_dependent_nmethod(nmethod* nm) {
1414 assert_locked_or_safepoint(CodeCache_lock);
1415 nmethodBucket* b = _dependencies;
1416 nmethodBucket* last = NULL;
1417 while (b != NULL) {
1418 if (nm == b->get_nmethod()) {
1419 b->increment();
1420 return;
1421 }
1422 b = b->next();
1423 }
1424 _dependencies = new nmethodBucket(nm, _dependencies);
1425 }
1426
1427
1428 //
1429 // Decrement count of the nmethod in the dependency list and remove
1430 // the bucket competely when the count goes to 0. This method must
1431 // find a corresponding bucket otherwise there's a bug in the
1432 // recording of dependecies.
1433 //
1434 void instanceKlass::remove_dependent_nmethod(nmethod* nm) {
1435 assert_locked_or_safepoint(CodeCache_lock);
1436 nmethodBucket* b = _dependencies;
1437 nmethodBucket* last = NULL;
1438 while (b != NULL) {
1439 if (nm == b->get_nmethod()) {
1440 if (b->decrement() == 0) {
1441 if (last == NULL) {
1442 _dependencies = b->next();
1443 } else {
1444 last->set_next(b->next());
1445 }
1446 delete b;
1447 }
1448 return;
1449 }
1450 last = b;
1451 b = b->next();
1452 }
1453 #ifdef ASSERT
1454 tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1455 nm->print();
1456 #endif // ASSERT
1457 ShouldNotReachHere();
1458 }
1459
1460
1461 #ifndef PRODUCT
1462 void instanceKlass::print_dependent_nmethods(bool verbose) {
1463 nmethodBucket* b = _dependencies;
1464 int idx = 0;
1465 while (b != NULL) {
1466 nmethod* nm = b->get_nmethod();
1467 tty->print("[%d] count=%d { ", idx++, b->count());
1468 if (!verbose) {
1469 nm->print_on(tty, "nmethod");
1470 tty->print_cr(" } ");
1471 } else {
1472 nm->print();
1473 nm->print_dependencies();
1474 tty->print_cr("--- } ");
1475 }
1476 b = b->next();
1477 }
1478 }
1479
1480
1481 bool instanceKlass::is_dependent_nmethod(nmethod* nm) {
1482 nmethodBucket* b = _dependencies;
1483 while (b != NULL) {
1484 if (nm == b->get_nmethod()) {
1485 return true;
1486 }
1487 b = b->next();
1488 }
1489 return false;
1490 }
1491 #endif //PRODUCT
1492
1493
1494 #ifdef ASSERT
1495 template <class T> void assert_is_in(T *p) {
1496 T heap_oop = oopDesc::load_heap_oop(p);
1497 if (!oopDesc::is_null(heap_oop)) {
1498 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1499 assert(Universe::heap()->is_in(o), "should be in heap");
1500 }
1501 }
1502 template <class T> void assert_is_in_closed_subset(T *p) {
1503 T heap_oop = oopDesc::load_heap_oop(p);
1504 if (!oopDesc::is_null(heap_oop)) {
1505 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1506 assert(Universe::heap()->is_in_closed_subset(o), "should be in closed");
1507 }
1508 }
1509 template <class T> void assert_is_in_reserved(T *p) {
1510 T heap_oop = oopDesc::load_heap_oop(p);
1511 if (!oopDesc::is_null(heap_oop)) {
1512 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1513 assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
1514 }
1515 }
1516 template <class T> void assert_nothing(T *p) {}
1517
1518 #else
1519 template <class T> void assert_is_in(T *p) {}
1520 template <class T> void assert_is_in_closed_subset(T *p) {}
1521 template <class T> void assert_is_in_reserved(T *p) {}
1522 template <class T> void assert_nothing(T *p) {}
1523 #endif // ASSERT
1524
1525 //
1526 // Macros that iterate over areas of oops which are specialized on type of
1527 // oop pointer either narrow or wide, depending on UseCompressedOops
1528 //
1529 // Parameters are:
1530 // T - type of oop to point to (either oop or narrowOop)
1531 // start_p - starting pointer for region to iterate over
1532 // count - number of oops or narrowOops to iterate over
1533 // do_oop - action to perform on each oop (it's arbitrary C code which
1534 // makes it more efficient to put in a macro rather than making
1535 // it a template function)
1536 // assert_fn - assert function which is template function because performance
1537 // doesn't matter when enabled.
1538 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
1539 T, start_p, count, do_oop, \
1540 assert_fn) \
1541 { \
1542 T* p = (T*)(start_p); \
1543 T* const end = p + (count); \
1544 while (p < end) { \
1545 (assert_fn)(p); \
1546 do_oop; \
1547 ++p; \
1548 } \
1549 }
1550
1551 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
1552 T, start_p, count, do_oop, \
1553 assert_fn) \
1554 { \
1555 T* const start = (T*)(start_p); \
1556 T* p = start + (count); \
1557 while (start < p) { \
1558 --p; \
1559 (assert_fn)(p); \
1560 do_oop; \
1561 } \
1562 }
1563
1564 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
1565 T, start_p, count, low, high, \
1566 do_oop, assert_fn) \
1567 { \
1568 T* const l = (T*)(low); \
1569 T* const h = (T*)(high); \
1570 assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
1571 mask_bits((intptr_t)h, sizeof(T)-1) == 0, \
1572 "bounded region must be properly aligned"); \
1573 T* p = (T*)(start_p); \
1574 T* end = p + (count); \
1575 if (p < l) p = l; \
1576 if (end > h) end = h; \
1577 while (p < end) { \
1578 (assert_fn)(p); \
1579 do_oop; \
1580 ++p; \
1581 } \
1582 }
1583
1584
1585 // The following macros call specialized macros, passing either oop or
1586 // narrowOop as the specialization type. These test the UseCompressedOops
1587 // flag.
1588 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \
1589 { \
1590 /* Compute oopmap block range. The common case \
1591 is nonstatic_oop_map_size == 1. */ \
1592 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1593 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1594 if (UseCompressedOops) { \
1595 while (map < end_map) { \
1596 InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
1597 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1598 do_oop, assert_fn) \
1599 ++map; \
1600 } \
1601 } else { \
1602 while (map < end_map) { \
1603 InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
1604 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1605 do_oop, assert_fn) \
1606 ++map; \
1607 } \
1608 } \
1609 }
1610
1611 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \
1612 { \
1613 OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \
1614 OopMapBlock* map = start_map + nonstatic_oop_map_count(); \
1615 if (UseCompressedOops) { \
1616 while (start_map < map) { \
1617 --map; \
1618 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \
1619 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1620 do_oop, assert_fn) \
1621 } \
1622 } else { \
1623 while (start_map < map) { \
1624 --map; \
1625 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \
1626 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1627 do_oop, assert_fn) \
1628 } \
1629 } \
1630 }
1631
1632 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \
1633 assert_fn) \
1634 { \
1635 /* Compute oopmap block range. The common case is \
1636 nonstatic_oop_map_size == 1, so we accept the \
1637 usually non-existent extra overhead of examining \
1638 all the maps. */ \
1639 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1640 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1641 if (UseCompressedOops) { \
1642 while (map < end_map) { \
1643 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
1644 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1645 low, high, \
1646 do_oop, assert_fn) \
1647 ++map; \
1648 } \
1649 } else { \
1650 while (map < end_map) { \
1651 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
1652 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1653 low, high, \
1654 do_oop, assert_fn) \
1655 ++map; \
1656 } \
1657 } \
1658 }
1659
1660 void instanceKlass::oop_follow_contents(oop obj) {
1661 assert(obj != NULL, "can't follow the content of NULL object");
1662 obj->follow_header();
1663 InstanceKlass_OOP_MAP_ITERATE( \
1664 obj, \
1665 MarkSweep::mark_and_push(p), \
1666 assert_is_in_closed_subset)
1667 }
1668
1669 #ifndef SERIALGC
1670 void instanceKlass::oop_follow_contents(ParCompactionManager* cm,
1671 oop obj) {
1672 assert(obj != NULL, "can't follow the content of NULL object");
1673 obj->follow_header(cm);
1674 InstanceKlass_OOP_MAP_ITERATE( \
1675 obj, \
1676 PSParallelCompact::mark_and_push(cm, p), \
1677 assert_is_in)
1678 }
1679 #endif // SERIALGC
1680
1681 // closure's do_header() method dicates whether the given closure should be
1682 // applied to the klass ptr in the object header.
1683
1684 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
1685 \
1686 int instanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
1687 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
1688 /* header */ \
1689 if (closure->do_header()) { \
1690 obj->oop_iterate_header(closure); \
1691 } \
1692 InstanceKlass_OOP_MAP_ITERATE( \
1693 obj, \
1694 SpecializationStats:: \
1695 record_do_oop_call##nv_suffix(SpecializationStats::ik); \
1696 (closure)->do_oop##nv_suffix(p), \
1697 assert_is_in_closed_subset) \
1698 return size_helper(); \
1699 }
1700
1701 #ifndef SERIALGC
1702 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
1703 \
1704 int instanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \
1705 OopClosureType* closure) { \
1706 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
1707 /* header */ \
1708 if (closure->do_header()) { \
1709 obj->oop_iterate_header(closure); \
1710 } \
1711 /* instance variables */ \
1712 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
1713 obj, \
1714 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
1715 (closure)->do_oop##nv_suffix(p), \
1716 assert_is_in_closed_subset) \
1717 return size_helper(); \
1718 }
1719 #endif // !SERIALGC
1720
1721 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
1722 \
1723 int instanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \
1724 OopClosureType* closure, \
1725 MemRegion mr) { \
1726 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
1727 if (closure->do_header()) { \
1728 obj->oop_iterate_header(closure, mr); \
1729 } \
1730 InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
1731 obj, mr.start(), mr.end(), \
1732 (closure)->do_oop##nv_suffix(p), \
1733 assert_is_in_closed_subset) \
1734 return size_helper(); \
1735 }
1736
1737 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
1738 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
1739 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
1740 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
1741 #ifndef SERIALGC
1742 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
1743 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
1744 #endif // !SERIALGC
1745
1746 int instanceKlass::oop_adjust_pointers(oop obj) {
1747 int size = size_helper();
1748 InstanceKlass_OOP_MAP_ITERATE( \
1749 obj, \
1750 MarkSweep::adjust_pointer(p), \
1751 assert_is_in)
1752 obj->adjust_header();
1753 return size;
1754 }
1755
1756 #ifndef SERIALGC
1757 void instanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
1758 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
1759 obj, \
1760 if (PSScavenge::should_scavenge(p)) { \
1761 pm->claim_or_forward_depth(p); \
1762 }, \
1763 assert_nothing )
1764 }
1765
1766 int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
1767 InstanceKlass_OOP_MAP_ITERATE( \
1768 obj, \
1769 PSParallelCompact::adjust_pointer(p), \
1770 assert_nothing)
1771 return size_helper();
1772 }
1773
1774 #endif // SERIALGC
1775
1776 // This klass is alive but the implementor link is not followed/updated.
1777 // Subklass and sibling links are handled by Klass::follow_weak_klass_links
1778
1779 void instanceKlass::follow_weak_klass_links(
1780 BoolObjectClosure* is_alive, OopClosure* keep_alive) {
1781 assert(is_alive->do_object_b(as_klassOop()), "this oop should be live");
1782 if (ClassUnloading) {
1783 for (int i = 0; i < implementors_limit; i++) {
1784 klassOop impl = _implementors[i];
1785 if (impl == NULL) break; // no more in the list
1786 if (!is_alive->do_object_b(impl)) {
1787 // remove this guy from the list by overwriting him with the tail
1788 int lasti = --_nof_implementors;
1789 assert(lasti >= i && lasti < implementors_limit, "just checking");
1790 _implementors[i] = _implementors[lasti];
1791 _implementors[lasti] = NULL;
1792 --i; // rerun the loop at this index
1793 }
1794 }
1795 } else {
1796 for (int i = 0; i < implementors_limit; i++) {
1797 keep_alive->do_oop(&adr_implementors()[i]);
1798 }
1799 }
1800 Klass::follow_weak_klass_links(is_alive, keep_alive);
1801 }
1802
1803 void instanceKlass::remove_unshareable_info() {
1804 Klass::remove_unshareable_info();
1805 init_implementor();
1806 }
1807
1808 static void clear_all_breakpoints(methodOop m) {
1809 m->clear_all_breakpoints();
1810 }
1811
1812 void instanceKlass::release_C_heap_structures() {
1813 // Deallocate oop map cache
1814 if (_oop_map_cache != NULL) {
1815 delete _oop_map_cache;
1816 _oop_map_cache = NULL;
1817 }
1818
1819 // Deallocate JNI identifiers for jfieldIDs
1820 JNIid::deallocate(jni_ids());
1821 set_jni_ids(NULL);
1822
1823 jmethodID* jmeths = methods_jmethod_ids_acquire();
1824 if (jmeths != (jmethodID*)NULL) {
1825 release_set_methods_jmethod_ids(NULL);
1826 FreeHeap(jmeths);
1827 }
1828
1829 int* indices = methods_cached_itable_indices_acquire();
1830 if (indices != (int*)NULL) {
1831 release_set_methods_cached_itable_indices(NULL);
1832 FreeHeap(indices);
1833 }
1834
1835 // release dependencies
1836 nmethodBucket* b = _dependencies;
1837 _dependencies = NULL;
1838 while (b != NULL) {
1839 nmethodBucket* next = b->next();
1840 delete b;
1841 b = next;
1842 }
1843
1844 // Deallocate breakpoint records
1845 if (breakpoints() != 0x0) {
1846 methods_do(clear_all_breakpoints);
1847 assert(breakpoints() == 0x0, "should have cleared breakpoints");
1848 }
1849
1850 // deallocate information about previous versions
1851 if (_previous_versions != NULL) {
1852 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
1853 PreviousVersionNode * pv_node = _previous_versions->at(i);
1854 delete pv_node;
1855 }
1856 delete _previous_versions;
1857 _previous_versions = NULL;
1858 }
1859
1860 // deallocate the cached class file
1861 if (_cached_class_file_bytes != NULL) {
1862 os::free(_cached_class_file_bytes);
1863 _cached_class_file_bytes = NULL;
1864 _cached_class_file_len = 0;
1865 }
1866
1867 // Decrement symbol reference counts associated with the unloaded class.
1868 if (_name != NULL) _name->decrement_refcount();
1869 // unreference array name derived from this class name (arrays of an unloaded
1870 // class can't be referenced anymore).
1871 if (_array_name != NULL) _array_name->decrement_refcount();
1872 if (_source_file_name != NULL) _source_file_name->decrement_refcount();
1873 if (_source_debug_extension != NULL) _source_debug_extension->decrement_refcount();
1874 // walk constant pool and decrement symbol reference counts
1875 _constants->unreference_symbols();
1876 }
1877
1878 void instanceKlass::set_source_file_name(Symbol* n) {
1879 _source_file_name = n;
1880 if (_source_file_name != NULL) _source_file_name->increment_refcount();
1881 }
1882
1883 void instanceKlass::set_source_debug_extension(Symbol* n) {
1884 _source_debug_extension = n;
1885 if (_source_debug_extension != NULL) _source_debug_extension->increment_refcount();
1886 }
1887
1888 address instanceKlass::static_field_addr(int offset) {
1889 return (address)(offset + instanceMirrorKlass::offset_of_static_fields() + (intptr_t)java_mirror());
1890 }
1891
1892
1893 const char* instanceKlass::signature_name() const {
1894 const char* src = (const char*) (name()->as_C_string());
1895 const int src_length = (int)strlen(src);
1896 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
1897 int src_index = 0;
1898 int dest_index = 0;
1899 dest[dest_index++] = 'L';
1900 while (src_index < src_length) {
1901 dest[dest_index++] = src[src_index++];
1902 }
1903 dest[dest_index++] = ';';
1904 dest[dest_index] = '\0';
1905 return dest;
1906 }
1907
1908 // different verisons of is_same_class_package
1909 bool instanceKlass::is_same_class_package(klassOop class2) {
1910 klassOop class1 = as_klassOop();
1911 oop classloader1 = instanceKlass::cast(class1)->class_loader();
1912 Symbol* classname1 = Klass::cast(class1)->name();
1913
1914 if (Klass::cast(class2)->oop_is_objArray()) {
1915 class2 = objArrayKlass::cast(class2)->bottom_klass();
1916 }
1917 oop classloader2;
1918 if (Klass::cast(class2)->oop_is_instance()) {
1919 classloader2 = instanceKlass::cast(class2)->class_loader();
1920 } else {
1921 assert(Klass::cast(class2)->oop_is_typeArray(), "should be type array");
1922 classloader2 = NULL;
1923 }
1924 Symbol* classname2 = Klass::cast(class2)->name();
1925
1926 return instanceKlass::is_same_class_package(classloader1, classname1,
1927 classloader2, classname2);
1928 }
1929
1930 bool instanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
1931 klassOop class1 = as_klassOop();
1932 oop classloader1 = instanceKlass::cast(class1)->class_loader();
1933 Symbol* classname1 = Klass::cast(class1)->name();
1934
1935 return instanceKlass::is_same_class_package(classloader1, classname1,
1936 classloader2, classname2);
1937 }
1938
1939 // return true if two classes are in the same package, classloader
1940 // and classname information is enough to determine a class's package
1941 bool instanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
1942 oop class_loader2, Symbol* class_name2) {
1943 if (class_loader1 != class_loader2) {
1944 return false;
1945 } else if (class_name1 == class_name2) {
1946 return true; // skip painful bytewise comparison
1947 } else {
1948 ResourceMark rm;
1949
1950 // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
1951 // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
1952 // Otherwise, we just compare jbyte values between the strings.
1953 const jbyte *name1 = class_name1->base();
1954 const jbyte *name2 = class_name2->base();
1955
1956 const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
1957 const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
1958
1959 if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
1960 // One of the two doesn't have a package. Only return true
1961 // if the other one also doesn't have a package.
1962 return last_slash1 == last_slash2;
1963 } else {
1964 // Skip over '['s
1965 if (*name1 == '[') {
1966 do {
1967 name1++;
1968 } while (*name1 == '[');
1969 if (*name1 != 'L') {
1970 // Something is terribly wrong. Shouldn't be here.
1971 return false;
1972 }
1973 }
1974 if (*name2 == '[') {
1975 do {
1976 name2++;
1977 } while (*name2 == '[');
1978 if (*name2 != 'L') {
1979 // Something is terribly wrong. Shouldn't be here.
1980 return false;
1981 }
1982 }
1983
1984 // Check that package part is identical
1985 int length1 = last_slash1 - name1;
1986 int length2 = last_slash2 - name2;
1987
1988 return UTF8::equal(name1, length1, name2, length2);
1989 }
1990 }
1991 }
1992
1993 // Returns true iff super_method can be overridden by a method in targetclassname
1994 // See JSL 3rd edition 8.4.6.1
1995 // Assumes name-signature match
1996 // "this" is instanceKlass of super_method which must exist
1997 // note that the instanceKlass of the method in the targetclassname has not always been created yet
1998 bool instanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
1999 // Private methods can not be overridden
2000 if (super_method->is_private()) {
2001 return false;
2002 }
2003 // If super method is accessible, then override
2004 if ((super_method->is_protected()) ||
2005 (super_method->is_public())) {
2006 return true;
2007 }
2008 // Package-private methods are not inherited outside of package
2009 assert(super_method->is_package_private(), "must be package private");
2010 return(is_same_class_package(targetclassloader(), targetclassname));
2011 }
2012
2013 /* defined for now in jvm.cpp, for historical reasons *--
2014 klassOop instanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2015 Symbol*& simple_name_result, TRAPS) {
2016 ...
2017 }
2018 */
2019
2020 // tell if two classes have the same enclosing class (at package level)
2021 bool instanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2022 klassOop class2_oop, TRAPS) {
2023 if (class2_oop == class1->as_klassOop()) return true;
2024 if (!Klass::cast(class2_oop)->oop_is_instance()) return false;
2025 instanceKlassHandle class2(THREAD, class2_oop);
2026
2027 // must be in same package before we try anything else
2028 if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2029 return false;
2030
2031 // As long as there is an outer1.getEnclosingClass,
2032 // shift the search outward.
2033 instanceKlassHandle outer1 = class1;
2034 for (;;) {
2035 // As we walk along, look for equalities between outer1 and class2.
2036 // Eventually, the walks will terminate as outer1 stops
2037 // at the top-level class around the original class.
2038 bool ignore_inner_is_member;
2039 klassOop next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2040 CHECK_false);
2041 if (next == NULL) break;
2042 if (next == class2()) return true;
2043 outer1 = instanceKlassHandle(THREAD, next);
2044 }
2045
2046 // Now do the same for class2.
2047 instanceKlassHandle outer2 = class2;
2048 for (;;) {
2049 bool ignore_inner_is_member;
2050 klassOop next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2051 CHECK_false);
2052 if (next == NULL) break;
2053 // Might as well check the new outer against all available values.
2054 if (next == class1()) return true;
2055 if (next == outer1()) return true;
2056 outer2 = instanceKlassHandle(THREAD, next);
2057 }
2058
2059 // If by this point we have not found an equality between the
2060 // two classes, we know they are in separate package members.
2061 return false;
2062 }
2063
2064
2065 jint instanceKlass::compute_modifier_flags(TRAPS) const {
2066 klassOop k = as_klassOop();
2067 jint access = access_flags().as_int();
2068
2069 // But check if it happens to be member class.
2070 typeArrayOop inner_class_list = inner_classes();
2071 int length = (inner_class_list == NULL) ? 0 : inner_class_list->length();
2072 assert (length % instanceKlass::inner_class_next_offset == 0, "just checking");
2073 if (length > 0) {
2074 typeArrayHandle inner_class_list_h(THREAD, inner_class_list);
2075 instanceKlassHandle ik(THREAD, k);
2076 for (int i = 0; i < length; i += instanceKlass::inner_class_next_offset) {
2077 int ioff = inner_class_list_h->ushort_at(
2078 i + instanceKlass::inner_class_inner_class_info_offset);
2079
2080 // Inner class attribute can be zero, skip it.
2081 // Strange but true: JVM spec. allows null inner class refs.
2082 if (ioff == 0) continue;
2083
2084 // only look at classes that are already loaded
2085 // since we are looking for the flags for our self.
2086 Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2087 if ((ik->name() == inner_name)) {
2088 // This is really a member class.
2089 access = inner_class_list_h->ushort_at(i + instanceKlass::inner_class_access_flags_offset);
2090 break;
2091 }
2092 }
2093 }
2094 // Remember to strip ACC_SUPER bit
2095 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2096 }
2097
2098 jint instanceKlass::jvmti_class_status() const {
2099 jint result = 0;
2100
2101 if (is_linked()) {
2102 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2103 }
2104
2105 if (is_initialized()) {
2106 assert(is_linked(), "Class status is not consistent");
2107 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2108 }
2109 if (is_in_error_state()) {
2110 result |= JVMTI_CLASS_STATUS_ERROR;
2111 }
2112 return result;
2113 }
2114
2115 methodOop instanceKlass::method_at_itable(klassOop holder, int index, TRAPS) {
2116 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2117 int method_table_offset_in_words = ioe->offset()/wordSize;
2118 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2119 / itableOffsetEntry::size();
2120
2121 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2122 // If the interface isn't implemented by the receiver class,
2123 // the VM should throw IncompatibleClassChangeError.
2124 if (cnt >= nof_interfaces) {
2125 THROW_0(vmSymbols::java_lang_IncompatibleClassChangeError());
2126 }
2127
2128 klassOop ik = ioe->interface_klass();
2129 if (ik == holder) break;
2130 }
2131
2132 itableMethodEntry* ime = ioe->first_method_entry(as_klassOop());
2133 methodOop m = ime[index].method();
2134 if (m == NULL) {
2135 THROW_0(vmSymbols::java_lang_AbstractMethodError());
2136 }
2137 return m;
2138 }
2139
2140 // On-stack replacement stuff
2141 void instanceKlass::add_osr_nmethod(nmethod* n) {
2142 // only one compilation can be active
2143 NEEDS_CLEANUP
2144 // This is a short non-blocking critical region, so the no safepoint check is ok.
2145 OsrList_lock->lock_without_safepoint_check();
2146 assert(n->is_osr_method(), "wrong kind of nmethod");
2147 n->set_osr_link(osr_nmethods_head());
2148 set_osr_nmethods_head(n);
2149 // Raise the highest osr level if necessary
2150 if (TieredCompilation) {
2151 methodOop m = n->method();
2152 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2153 }
2154 // Remember to unlock again
2155 OsrList_lock->unlock();
2156
2157 // Get rid of the osr methods for the same bci that have lower levels.
2158 if (TieredCompilation) {
2159 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2160 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2161 if (inv != NULL && inv->is_in_use()) {
2162 inv->make_not_entrant();
2163 }
2164 }
2165 }
2166 }
2167
2168
2169 void instanceKlass::remove_osr_nmethod(nmethod* n) {
2170 // This is a short non-blocking critical region, so the no safepoint check is ok.
2171 OsrList_lock->lock_without_safepoint_check();
2172 assert(n->is_osr_method(), "wrong kind of nmethod");
2173 nmethod* last = NULL;
2174 nmethod* cur = osr_nmethods_head();
2175 int max_level = CompLevel_none; // Find the max comp level excluding n
2176 methodOop m = n->method();
2177 // Search for match
2178 while(cur != NULL && cur != n) {
2179 if (TieredCompilation) {
2180 // Find max level before n
2181 max_level = MAX2(max_level, cur->comp_level());
2182 }
2183 last = cur;
2184 cur = cur->osr_link();
2185 }
2186 nmethod* next = NULL;
2187 if (cur == n) {
2188 next = cur->osr_link();
2189 if (last == NULL) {
2190 // Remove first element
2191 set_osr_nmethods_head(next);
2192 } else {
2193 last->set_osr_link(next);
2194 }
2195 }
2196 n->set_osr_link(NULL);
2197 if (TieredCompilation) {
2198 cur = next;
2199 while (cur != NULL) {
2200 // Find max level after n
2201 max_level = MAX2(max_level, cur->comp_level());
2202 cur = cur->osr_link();
2203 }
2204 m->set_highest_osr_comp_level(max_level);
2205 }
2206 // Remember to unlock again
2207 OsrList_lock->unlock();
2208 }
2209
2210 nmethod* instanceKlass::lookup_osr_nmethod(const methodOop m, int bci, int comp_level, bool match_level) const {
2211 // This is a short non-blocking critical region, so the no safepoint check is ok.
2212 OsrList_lock->lock_without_safepoint_check();
2213 nmethod* osr = osr_nmethods_head();
2214 nmethod* best = NULL;
2215 while (osr != NULL) {
2216 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2217 // There can be a time when a c1 osr method exists but we are waiting
2218 // for a c2 version. When c2 completes its osr nmethod we will trash
2219 // the c1 version and only be able to find the c2 version. However
2220 // while we overflow in the c1 code at back branches we don't want to
2221 // try and switch to the same code as we are already running
2222
2223 if (osr->method() == m &&
2224 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2225 if (match_level) {
2226 if (osr->comp_level() == comp_level) {
2227 // Found a match - return it.
2228 OsrList_lock->unlock();
2229 return osr;
2230 }
2231 } else {
2232 if (best == NULL || (osr->comp_level() > best->comp_level())) {
2233 if (osr->comp_level() == CompLevel_highest_tier) {
2234 // Found the best possible - return it.
2235 OsrList_lock->unlock();
2236 return osr;
2237 }
2238 best = osr;
2239 }
2240 }
2241 }
2242 osr = osr->osr_link();
2243 }
2244 OsrList_lock->unlock();
2245 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2246 return best;
2247 }
2248 return NULL;
2249 }
2250
2251 // -----------------------------------------------------------------------------------------------------
2252 #ifndef PRODUCT
2253
2254 // Printing
2255
2256 #define BULLET " - "
2257
2258 void FieldPrinter::do_field(fieldDescriptor* fd) {
2259 _st->print(BULLET);
2260 if (_obj == NULL) {
2261 fd->print_on(_st);
2262 _st->cr();
2263 } else {
2264 fd->print_on_for(_st, _obj);
2265 _st->cr();
2266 }
2267 }
2268
2269
2270 void instanceKlass::oop_print_on(oop obj, outputStream* st) {
2271 Klass::oop_print_on(obj, st);
2272
2273 if (as_klassOop() == SystemDictionary::String_klass()) {
2274 typeArrayOop value = java_lang_String::value(obj);
2275 juint offset = java_lang_String::offset(obj);
2276 juint length = java_lang_String::length(obj);
2277 if (value != NULL &&
2278 value->is_typeArray() &&
2279 offset <= (juint) value->length() &&
2280 offset + length <= (juint) value->length()) {
2281 st->print(BULLET"string: ");
2282 Handle h_obj(obj);
2283 java_lang_String::print(h_obj, st);
2284 st->cr();
2285 if (!WizardMode) return; // that is enough
2286 }
2287 }
2288
2289 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
2290 FieldPrinter print_field(st, obj);
2291 do_nonstatic_fields(&print_field);
2292
2293 if (as_klassOop() == SystemDictionary::Class_klass()) {
2294 st->print(BULLET"signature: ");
2295 java_lang_Class::print_signature(obj, st);
2296 st->cr();
2297 klassOop mirrored_klass = java_lang_Class::as_klassOop(obj);
2298 st->print(BULLET"fake entry for mirror: ");
2299 mirrored_klass->print_value_on(st);
2300 st->cr();
2301 st->print(BULLET"fake entry resolved_constructor: ");
2302 methodOop ctor = java_lang_Class::resolved_constructor(obj);
2303 ctor->print_value_on(st);
2304 klassOop array_klass = java_lang_Class::array_klass(obj);
2305 st->cr();
2306 st->print(BULLET"fake entry for array: ");
2307 array_klass->print_value_on(st);
2308 st->cr();
2309 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
2310 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
2311 klassOop real_klass = java_lang_Class::as_klassOop(obj);
2312 if (real_klass != NULL && real_klass->klass_part()->oop_is_instance()) {
2313 instanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
2314 }
2315 } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
2316 st->print(BULLET"signature: ");
2317 java_lang_invoke_MethodType::print_signature(obj, st);
2318 st->cr();
2319 }
2320 }
2321
2322 #endif //PRODUCT
2323
2324 void instanceKlass::oop_print_value_on(oop obj, outputStream* st) {
2325 st->print("a ");
2326 name()->print_value_on(st);
2327 obj->print_address_on(st);
2328 if (as_klassOop() == SystemDictionary::String_klass()
2329 && java_lang_String::value(obj) != NULL) {
2330 ResourceMark rm;
2331 int len = java_lang_String::length(obj);
2332 int plen = (len < 24 ? len : 12);
2333 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
2334 st->print(" = \"%s\"", str);
2335 if (len > plen)
2336 st->print("...[%d]", len);
2337 } else if (as_klassOop() == SystemDictionary::Class_klass()) {
2338 klassOop k = java_lang_Class::as_klassOop(obj);
2339 st->print(" = ");
2340 if (k != NULL) {
2341 k->print_value_on(st);
2342 } else {
2343 const char* tname = type2name(java_lang_Class::primitive_type(obj));
2344 st->print("%s", tname ? tname : "type?");
2345 }
2346 } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
2347 st->print(" = ");
2348 java_lang_invoke_MethodType::print_signature(obj, st);
2349 } else if (java_lang_boxing_object::is_instance(obj)) {
2350 st->print(" = ");
2351 java_lang_boxing_object::print(obj, st);
2352 }
2353 }
2354
2355 const char* instanceKlass::internal_name() const {
2356 return external_name();
2357 }
2358
2359 // Verification
2360
2361 class VerifyFieldClosure: public OopClosure {
2362 protected:
2363 template <class T> void do_oop_work(T* p) {
2364 guarantee(Universe::heap()->is_in_closed_subset(p), "should be in heap");
2365 oop obj = oopDesc::load_decode_heap_oop(p);
2366 if (!obj->is_oop_or_null()) {
2367 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
2368 Universe::print();
2369 guarantee(false, "boom");
2370 }
2371 }
2372 public:
2373 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
2374 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
2375 };
2376
2377 void instanceKlass::oop_verify_on(oop obj, outputStream* st) {
2378 Klass::oop_verify_on(obj, st);
2379 VerifyFieldClosure blk;
2380 oop_oop_iterate(obj, &blk);
2381 }
2382
2383 #ifndef PRODUCT
2384
2385 void instanceKlass::verify_class_klass_nonstatic_oop_maps(klassOop k) {
2386 // This verification code is disabled. JDK_Version::is_gte_jdk14x_version()
2387 // cannot be called since this function is called before the VM is
2388 // able to determine what JDK version is running with.
2389 // The check below always is false since 1.4.
2390 return;
2391
2392 // This verification code temporarily disabled for the 1.4
2393 // reflection implementation since java.lang.Class now has
2394 // Java-level instance fields. Should rewrite this to handle this
2395 // case.
2396 if (!(JDK_Version::is_gte_jdk14x_version() && UseNewReflection)) {
2397 // Verify that java.lang.Class instances have a fake oop field added.
2398 instanceKlass* ik = instanceKlass::cast(k);
2399
2400 // Check that we have the right class
2401 static bool first_time = true;
2402 guarantee(k == SystemDictionary::Class_klass() && first_time, "Invalid verify of maps");
2403 first_time = false;
2404 const int extra = java_lang_Class::number_of_fake_oop_fields;
2405 guarantee(ik->nonstatic_field_size() == extra, "just checking");
2406 guarantee(ik->nonstatic_oop_map_count() == 1, "just checking");
2407 guarantee(ik->size_helper() == align_object_size(instanceOopDesc::header_size() + extra), "just checking");
2408
2409 // Check that the map is (2,extra)
2410 int offset = java_lang_Class::klass_offset;
2411
2412 OopMapBlock* map = ik->start_of_nonstatic_oop_maps();
2413 guarantee(map->offset() == offset && map->count() == (unsigned int) extra,
2414 "sanity");
2415 }
2416 }
2417
2418 #endif // ndef PRODUCT
2419
2420 // JNIid class for jfieldIDs only
2421 // Note to reviewers:
2422 // These JNI functions are just moved over to column 1 and not changed
2423 // in the compressed oops workspace.
2424 JNIid::JNIid(klassOop holder, int offset, JNIid* next) {
2425 _holder = holder;
2426 _offset = offset;
2427 _next = next;
2428 debug_only(_is_static_field_id = false;)
2429 }
2430
2431
2432 JNIid* JNIid::find(int offset) {
2433 JNIid* current = this;
2434 while (current != NULL) {
2435 if (current->offset() == offset) return current;
2436 current = current->next();
2437 }
2438 return NULL;
2439 }
2440
2441 void JNIid::oops_do(OopClosure* f) {
2442 for (JNIid* cur = this; cur != NULL; cur = cur->next()) {
2443 f->do_oop(cur->holder_addr());
2444 }
2445 }
2446
2447 void JNIid::deallocate(JNIid* current) {
2448 while (current != NULL) {
2449 JNIid* next = current->next();
2450 delete current;
2451 current = next;
2452 }
2453 }
2454
2455
2456 void JNIid::verify(klassOop holder) {
2457 int first_field_offset = instanceMirrorKlass::offset_of_static_fields();
2458 int end_field_offset;
2459 end_field_offset = first_field_offset + (instanceKlass::cast(holder)->static_field_size() * wordSize);
2460
2461 JNIid* current = this;
2462 while (current != NULL) {
2463 guarantee(current->holder() == holder, "Invalid klass in JNIid");
2464 #ifdef ASSERT
2465 int o = current->offset();
2466 if (current->is_static_field_id()) {
2467 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
2468 }
2469 #endif
2470 current = current->next();
2471 }
2472 }
2473
2474
2475 #ifdef ASSERT
2476 void instanceKlass::set_init_state(ClassState state) {
2477 bool good_state = as_klassOop()->is_shared() ? (_init_state <= state)
2478 : (_init_state < state);
2479 assert(good_state || state == allocated, "illegal state transition");
2480 _init_state = state;
2481 }
2482 #endif
2483
2484
2485 // RedefineClasses() support for previous versions:
2486
2487 // Add an information node that contains weak references to the
2488 // interesting parts of the previous version of the_class.
2489 // This is also where we clean out any unused weak references.
2490 // Note that while we delete nodes from the _previous_versions
2491 // array, we never delete the array itself until the klass is
2492 // unloaded. The has_been_redefined() query depends on that fact.
2493 //
2494 void instanceKlass::add_previous_version(instanceKlassHandle ikh,
2495 BitMap* emcp_methods, int emcp_method_count) {
2496 assert(Thread::current()->is_VM_thread(),
2497 "only VMThread can add previous versions");
2498
2499 if (_previous_versions == NULL) {
2500 // This is the first previous version so make some space.
2501 // Start with 2 elements under the assumption that the class
2502 // won't be redefined much.
2503 _previous_versions = new (ResourceObj::C_HEAP)
2504 GrowableArray<PreviousVersionNode *>(2, true);
2505 }
2506
2507 // RC_TRACE macro has an embedded ResourceMark
2508 RC_TRACE(0x00000100, ("adding previous version ref for %s @%d, EMCP_cnt=%d",
2509 ikh->external_name(), _previous_versions->length(), emcp_method_count));
2510 constantPoolHandle cp_h(ikh->constants());
2511 jobject cp_ref;
2512 if (cp_h->is_shared()) {
2513 // a shared ConstantPool requires a regular reference; a weak
2514 // reference would be collectible
2515 cp_ref = JNIHandles::make_global(cp_h);
2516 } else {
2517 cp_ref = JNIHandles::make_weak_global(cp_h);
2518 }
2519 PreviousVersionNode * pv_node = NULL;
2520 objArrayOop old_methods = ikh->methods();
2521
2522 if (emcp_method_count == 0) {
2523 // non-shared ConstantPool gets a weak reference
2524 pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), NULL);
2525 RC_TRACE(0x00000400,
2526 ("add: all methods are obsolete; flushing any EMCP weak refs"));
2527 } else {
2528 int local_count = 0;
2529 GrowableArray<jweak>* method_refs = new (ResourceObj::C_HEAP)
2530 GrowableArray<jweak>(emcp_method_count, true);
2531 for (int i = 0; i < old_methods->length(); i++) {
2532 if (emcp_methods->at(i)) {
2533 // this old method is EMCP so save a weak ref
2534 methodOop old_method = (methodOop) old_methods->obj_at(i);
2535 methodHandle old_method_h(old_method);
2536 jweak method_ref = JNIHandles::make_weak_global(old_method_h);
2537 method_refs->append(method_ref);
2538 if (++local_count >= emcp_method_count) {
2539 // no more EMCP methods so bail out now
2540 break;
2541 }
2542 }
2543 }
2544 // non-shared ConstantPool gets a weak reference
2545 pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), method_refs);
2546 }
2547
2548 _previous_versions->append(pv_node);
2549
2550 // Using weak references allows the interesting parts of previous
2551 // classes to be GC'ed when they are no longer needed. Since the
2552 // caller is the VMThread and we are at a safepoint, this is a good
2553 // time to clear out unused weak references.
2554
2555 RC_TRACE(0x00000400, ("add: previous version length=%d",
2556 _previous_versions->length()));
2557
2558 // skip the last entry since we just added it
2559 for (int i = _previous_versions->length() - 2; i >= 0; i--) {
2560 // check the previous versions array for a GC'ed weak refs
2561 pv_node = _previous_versions->at(i);
2562 cp_ref = pv_node->prev_constant_pool();
2563 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
2564 if (cp_ref == NULL) {
2565 delete pv_node;
2566 _previous_versions->remove_at(i);
2567 // Since we are traversing the array backwards, we don't have to
2568 // do anything special with the index.
2569 continue; // robustness
2570 }
2571
2572 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2573 if (cp == NULL) {
2574 // this entry has been GC'ed so remove it
2575 delete pv_node;
2576 _previous_versions->remove_at(i);
2577 // Since we are traversing the array backwards, we don't have to
2578 // do anything special with the index.
2579 continue;
2580 } else {
2581 RC_TRACE(0x00000400, ("add: previous version @%d is alive", i));
2582 }
2583
2584 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2585 if (method_refs != NULL) {
2586 RC_TRACE(0x00000400, ("add: previous methods length=%d",
2587 method_refs->length()));
2588 for (int j = method_refs->length() - 1; j >= 0; j--) {
2589 jweak method_ref = method_refs->at(j);
2590 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
2591 if (method_ref == NULL) {
2592 method_refs->remove_at(j);
2593 // Since we are traversing the array backwards, we don't have to
2594 // do anything special with the index.
2595 continue; // robustness
2596 }
2597
2598 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2599 if (method == NULL || emcp_method_count == 0) {
2600 // This method entry has been GC'ed or the current
2601 // RedefineClasses() call has made all methods obsolete
2602 // so remove it.
2603 JNIHandles::destroy_weak_global(method_ref);
2604 method_refs->remove_at(j);
2605 } else {
2606 // RC_TRACE macro has an embedded ResourceMark
2607 RC_TRACE(0x00000400,
2608 ("add: %s(%s): previous method @%d in version @%d is alive",
2609 method->name()->as_C_string(), method->signature()->as_C_string(),
2610 j, i));
2611 }
2612 }
2613 }
2614 }
2615
2616 int obsolete_method_count = old_methods->length() - emcp_method_count;
2617
2618 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
2619 _previous_versions->length() > 1) {
2620 // We have a mix of obsolete and EMCP methods. If there is more
2621 // than the previous version that we just added, then we have to
2622 // clear out any matching EMCP method entries the hard way.
2623 int local_count = 0;
2624 for (int i = 0; i < old_methods->length(); i++) {
2625 if (!emcp_methods->at(i)) {
2626 // only obsolete methods are interesting
2627 methodOop old_method = (methodOop) old_methods->obj_at(i);
2628 Symbol* m_name = old_method->name();
2629 Symbol* m_signature = old_method->signature();
2630
2631 // skip the last entry since we just added it
2632 for (int j = _previous_versions->length() - 2; j >= 0; j--) {
2633 // check the previous versions array for a GC'ed weak refs
2634 pv_node = _previous_versions->at(j);
2635 cp_ref = pv_node->prev_constant_pool();
2636 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
2637 if (cp_ref == NULL) {
2638 delete pv_node;
2639 _previous_versions->remove_at(j);
2640 // Since we are traversing the array backwards, we don't have to
2641 // do anything special with the index.
2642 continue; // robustness
2643 }
2644
2645 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2646 if (cp == NULL) {
2647 // this entry has been GC'ed so remove it
2648 delete pv_node;
2649 _previous_versions->remove_at(j);
2650 // Since we are traversing the array backwards, we don't have to
2651 // do anything special with the index.
2652 continue;
2653 }
2654
2655 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2656 if (method_refs == NULL) {
2657 // We have run into a PreviousVersion generation where
2658 // all methods were made obsolete during that generation's
2659 // RedefineClasses() operation. At the time of that
2660 // operation, all EMCP methods were flushed so we don't
2661 // have to go back any further.
2662 //
2663 // A NULL method_refs is different than an empty method_refs.
2664 // We cannot infer any optimizations about older generations
2665 // from an empty method_refs for the current generation.
2666 break;
2667 }
2668
2669 for (int k = method_refs->length() - 1; k >= 0; k--) {
2670 jweak method_ref = method_refs->at(k);
2671 assert(method_ref != NULL,
2672 "weak method ref was unexpectedly cleared");
2673 if (method_ref == NULL) {
2674 method_refs->remove_at(k);
2675 // Since we are traversing the array backwards, we don't
2676 // have to do anything special with the index.
2677 continue; // robustness
2678 }
2679
2680 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2681 if (method == NULL) {
2682 // this method entry has been GC'ed so skip it
2683 JNIHandles::destroy_weak_global(method_ref);
2684 method_refs->remove_at(k);
2685 continue;
2686 }
2687
2688 if (method->name() == m_name &&
2689 method->signature() == m_signature) {
2690 // The current RedefineClasses() call has made all EMCP
2691 // versions of this method obsolete so mark it as obsolete
2692 // and remove the weak ref.
2693 RC_TRACE(0x00000400,
2694 ("add: %s(%s): flush obsolete method @%d in version @%d",
2695 m_name->as_C_string(), m_signature->as_C_string(), k, j));
2696
2697 method->set_is_obsolete();
2698 JNIHandles::destroy_weak_global(method_ref);
2699 method_refs->remove_at(k);
2700 break;
2701 }
2702 }
2703
2704 // The previous loop may not find a matching EMCP method, but
2705 // that doesn't mean that we can optimize and not go any
2706 // further back in the PreviousVersion generations. The EMCP
2707 // method for this generation could have already been GC'ed,
2708 // but there still may be an older EMCP method that has not
2709 // been GC'ed.
2710 }
2711
2712 if (++local_count >= obsolete_method_count) {
2713 // no more obsolete methods so bail out now
2714 break;
2715 }
2716 }
2717 }
2718 }
2719 } // end add_previous_version()
2720
2721
2722 // Determine if instanceKlass has a previous version.
2723 bool instanceKlass::has_previous_version() const {
2724 if (_previous_versions == NULL) {
2725 // no previous versions array so answer is easy
2726 return false;
2727 }
2728
2729 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
2730 // Check the previous versions array for an info node that hasn't
2731 // been GC'ed
2732 PreviousVersionNode * pv_node = _previous_versions->at(i);
2733
2734 jobject cp_ref = pv_node->prev_constant_pool();
2735 assert(cp_ref != NULL, "cp reference was unexpectedly cleared");
2736 if (cp_ref == NULL) {
2737 continue; // robustness
2738 }
2739
2740 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2741 if (cp != NULL) {
2742 // we have at least one previous version
2743 return true;
2744 }
2745
2746 // We don't have to check the method refs. If the constant pool has
2747 // been GC'ed then so have the methods.
2748 }
2749
2750 // all of the underlying nodes' info has been GC'ed
2751 return false;
2752 } // end has_previous_version()
2753
2754 methodOop instanceKlass::method_with_idnum(int idnum) {
2755 methodOop m = NULL;
2756 if (idnum < methods()->length()) {
2757 m = (methodOop) methods()->obj_at(idnum);
2758 }
2759 if (m == NULL || m->method_idnum() != idnum) {
2760 for (int index = 0; index < methods()->length(); ++index) {
2761 m = (methodOop) methods()->obj_at(index);
2762 if (m->method_idnum() == idnum) {
2763 return m;
2764 }
2765 }
2766 }
2767 return m;
2768 }
2769
2770
2771 // Set the annotation at 'idnum' to 'anno'.
2772 // We don't want to create or extend the array if 'anno' is NULL, since that is the
2773 // default value. However, if the array exists and is long enough, we must set NULL values.
2774 void instanceKlass::set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p) {
2775 objArrayOop md = *md_p;
2776 if (md != NULL && md->length() > idnum) {
2777 md->obj_at_put(idnum, anno);
2778 } else if (anno != NULL) {
2779 // create the array
2780 int length = MAX2(idnum+1, (int)_idnum_allocated_count);
2781 md = oopFactory::new_system_objArray(length, Thread::current());
2782 if (*md_p != NULL) {
2783 // copy the existing entries
2784 for (int index = 0; index < (*md_p)->length(); index++) {
2785 md->obj_at_put(index, (*md_p)->obj_at(index));
2786 }
2787 }
2788 set_annotations(md, md_p);
2789 md->obj_at_put(idnum, anno);
2790 } // if no array and idnum isn't included there is nothing to do
2791 }
2792
2793 // Construct a PreviousVersionNode entry for the array hung off
2794 // the instanceKlass.
2795 PreviousVersionNode::PreviousVersionNode(jobject prev_constant_pool,
2796 bool prev_cp_is_weak, GrowableArray<jweak>* prev_EMCP_methods) {
2797
2798 _prev_constant_pool = prev_constant_pool;
2799 _prev_cp_is_weak = prev_cp_is_weak;
2800 _prev_EMCP_methods = prev_EMCP_methods;
2801 }
2802
2803
2804 // Destroy a PreviousVersionNode
2805 PreviousVersionNode::~PreviousVersionNode() {
2806 if (_prev_constant_pool != NULL) {
2807 if (_prev_cp_is_weak) {
2808 JNIHandles::destroy_weak_global(_prev_constant_pool);
2809 } else {
2810 JNIHandles::destroy_global(_prev_constant_pool);
2811 }
2812 }
2813
2814 if (_prev_EMCP_methods != NULL) {
2815 for (int i = _prev_EMCP_methods->length() - 1; i >= 0; i--) {
2816 jweak method_ref = _prev_EMCP_methods->at(i);
2817 if (method_ref != NULL) {
2818 JNIHandles::destroy_weak_global(method_ref);
2819 }
2820 }
2821 delete _prev_EMCP_methods;
2822 }
2823 }
2824
2825
2826 // Construct a PreviousVersionInfo entry
2827 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
2828 _prev_constant_pool_handle = constantPoolHandle(); // NULL handle
2829 _prev_EMCP_method_handles = NULL;
2830
2831 jobject cp_ref = pv_node->prev_constant_pool();
2832 assert(cp_ref != NULL, "constant pool ref was unexpectedly cleared");
2833 if (cp_ref == NULL) {
2834 return; // robustness
2835 }
2836
2837 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2838 if (cp == NULL) {
2839 // Weak reference has been GC'ed. Since the constant pool has been
2840 // GC'ed, the methods have also been GC'ed.
2841 return;
2842 }
2843
2844 // make the constantPoolOop safe to return
2845 _prev_constant_pool_handle = constantPoolHandle(cp);
2846
2847 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2848 if (method_refs == NULL) {
2849 // the instanceKlass did not have any EMCP methods
2850 return;
2851 }
2852
2853 _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
2854
2855 int n_methods = method_refs->length();
2856 for (int i = 0; i < n_methods; i++) {
2857 jweak method_ref = method_refs->at(i);
2858 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
2859 if (method_ref == NULL) {
2860 continue; // robustness
2861 }
2862
2863 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2864 if (method == NULL) {
2865 // this entry has been GC'ed so skip it
2866 continue;
2867 }
2868
2869 // make the methodOop safe to return
2870 _prev_EMCP_method_handles->append(methodHandle(method));
2871 }
2872 }
2873
2874
2875 // Destroy a PreviousVersionInfo
2876 PreviousVersionInfo::~PreviousVersionInfo() {
2877 // Since _prev_EMCP_method_handles is not C-heap allocated, we
2878 // don't have to delete it.
2879 }
2880
2881
2882 // Construct a helper for walking the previous versions array
2883 PreviousVersionWalker::PreviousVersionWalker(instanceKlass *ik) {
2884 _previous_versions = ik->previous_versions();
2885 _current_index = 0;
2886 // _hm needs no initialization
2887 _current_p = NULL;
2888 }
2889
2890
2891 // Destroy a PreviousVersionWalker
2892 PreviousVersionWalker::~PreviousVersionWalker() {
2893 // Delete the current info just in case the caller didn't walk to
2894 // the end of the previous versions list. No harm if _current_p is
2895 // already NULL.
2896 delete _current_p;
2897
2898 // When _hm is destroyed, all the Handles returned in
2899 // PreviousVersionInfo objects will be destroyed.
2900 // Also, after this destructor is finished it will be
2901 // safe to delete the GrowableArray allocated in the
2902 // PreviousVersionInfo objects.
2903 }
2904
2905
2906 // Return the interesting information for the next previous version
2907 // of the klass. Returns NULL if there are no more previous versions.
2908 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
2909 if (_previous_versions == NULL) {
2910 // no previous versions so nothing to return
2911 return NULL;
2912 }
2913
2914 delete _current_p; // cleanup the previous info for the caller
2915 _current_p = NULL; // reset to NULL so we don't delete same object twice
2916
2917 int length = _previous_versions->length();
2918
2919 while (_current_index < length) {
2920 PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
2921 PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP)
2922 PreviousVersionInfo(pv_node);
2923
2924 constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
2925 if (cp_h.is_null()) {
2926 delete pv_info;
2927
2928 // The underlying node's info has been GC'ed so try the next one.
2929 // We don't have to check the methods. If the constant pool has
2930 // GC'ed then so have the methods.
2931 continue;
2932 }
2933
2934 // Found a node with non GC'ed info so return it. The caller will
2935 // need to delete pv_info when they are done with it.
2936 _current_p = pv_info;
2937 return pv_info;
2938 }
2939
2940 // all of the underlying nodes' info has been GC'ed
2941 return NULL;
2942 } // end next_previous_version()