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