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