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 // nmethodBucket is used to record dependent nmethods for
1376 // deoptimization. nmethod dependencies are actually <klass, method>
1377 // pairs but we really only care about the klass part for purposes of
1378 // finding nmethods which might need to be deoptimized. Instead of
1379 // recording the method, a count of how many times a particular nmethod
1380 // was recorded is kept. This ensures that any recording errors are
1381 // noticed since an nmethod should be removed as many times are it's
1382 // added.
1383 //
1384 class nmethodBucket {
1385 private:
1386 nmethod* _nmethod;
1387 int _count;
1388 nmethodBucket* _next;
1389
1390 public:
1391 nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
1392 _nmethod = nmethod;
1393 _next = next;
1394 _count = 1;
1395 }
1396 int count() { return _count; }
1397 int increment() { _count += 1; return _count; }
1398 int decrement() { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
1399 nmethodBucket* next() { return _next; }
1400 void set_next(nmethodBucket* b) { _next = b; }
1401 nmethod* get_nmethod() { return _nmethod; }
1402 };
1403
1404
1405 //
1406 // Walk the list of dependent nmethods searching for nmethods which
1407 // are dependent on the changes that were passed in and mark them for
1408 // deoptimization. Returns the number of nmethods found.
1409 //
1410 int instanceKlass::mark_dependent_nmethods(DepChange& changes) {
1411 assert_locked_or_safepoint(CodeCache_lock);
1412 int found = 0;
1413 nmethodBucket* b = _dependencies;
1414 while (b != NULL) {
1415 nmethod* nm = b->get_nmethod();
1416 // since dependencies aren't removed until an nmethod becomes a zombie,
1417 // the dependency list may contain nmethods which aren't alive.
1418 if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1419 if (TraceDependencies) {
1420 ResourceMark rm;
1421 tty->print_cr("Marked for deoptimization");
1422 tty->print_cr(" context = %s", this->external_name());
1423 changes.print();
1424 nm->print();
1425 nm->print_dependencies();
1426 }
1427 nm->mark_for_deoptimization();
1428 found++;
1429 }
1430 b = b->next();
1431 }
1432 return found;
1433 }
1434
1435
1436 //
1437 // Add an nmethodBucket to the list of dependencies for this nmethod.
1438 // It's possible that an nmethod has multiple dependencies on this klass
1439 // so a count is kept for each bucket to guarantee that creation and
1440 // deletion of dependencies is consistent.
1441 //
1442 void instanceKlass::add_dependent_nmethod(nmethod* nm) {
1443 assert_locked_or_safepoint(CodeCache_lock);
1444 nmethodBucket* b = _dependencies;
1445 nmethodBucket* last = NULL;
1446 while (b != NULL) {
1447 if (nm == b->get_nmethod()) {
1448 b->increment();
1449 return;
1450 }
1451 b = b->next();
1452 }
1453 _dependencies = new nmethodBucket(nm, _dependencies);
1454 }
1455
1456
1457 //
1458 // Decrement count of the nmethod in the dependency list and remove
1459 // the bucket competely when the count goes to 0. This method must
1460 // find a corresponding bucket otherwise there's a bug in the
1461 // recording of dependecies.
1462 //
1463 void instanceKlass::remove_dependent_nmethod(nmethod* nm) {
1464 assert_locked_or_safepoint(CodeCache_lock);
1465 nmethodBucket* b = _dependencies;
1466 nmethodBucket* last = NULL;
1467 while (b != NULL) {
1468 if (nm == b->get_nmethod()) {
1469 if (b->decrement() == 0) {
1470 if (last == NULL) {
1471 _dependencies = b->next();
1472 } else {
1473 last->set_next(b->next());
1474 }
1475 delete b;
1476 }
1477 return;
1478 }
1479 last = b;
1480 b = b->next();
1481 }
1482 #ifdef ASSERT
1483 tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1484 nm->print();
1485 #endif // ASSERT
1486 ShouldNotReachHere();
1487 }
1488
1489
1490 #ifndef PRODUCT
1491 void instanceKlass::print_dependent_nmethods(bool verbose) {
1492 nmethodBucket* b = _dependencies;
1493 int idx = 0;
1494 while (b != NULL) {
1495 nmethod* nm = b->get_nmethod();
1496 tty->print("[%d] count=%d { ", idx++, b->count());
1497 if (!verbose) {
1498 nm->print_on(tty, "nmethod");
1499 tty->print_cr(" } ");
1500 } else {
1501 nm->print();
1502 nm->print_dependencies();
1503 tty->print_cr("--- } ");
1504 }
1505 b = b->next();
1506 }
1507 }
1508
1509
1510 bool instanceKlass::is_dependent_nmethod(nmethod* nm) {
1511 nmethodBucket* b = _dependencies;
1512 while (b != NULL) {
1513 if (nm == b->get_nmethod()) {
1514 return true;
1515 }
1516 b = b->next();
1517 }
1518 return false;
1519 }
1520 #endif //PRODUCT
1521
1522
1523 #ifdef ASSERT
1524 template <class T> void assert_is_in(T *p) {
1525 T heap_oop = oopDesc::load_heap_oop(p);
1526 if (!oopDesc::is_null(heap_oop)) {
1527 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1528 assert(Universe::heap()->is_in(o), "should be in heap");
1529 }
1530 }
1531 template <class T> void assert_is_in_closed_subset(T *p) {
1532 T heap_oop = oopDesc::load_heap_oop(p);
1533 if (!oopDesc::is_null(heap_oop)) {
1534 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1535 assert(Universe::heap()->is_in_closed_subset(o), "should be in closed");
1536 }
1537 }
1538 template <class T> void assert_is_in_reserved(T *p) {
1539 T heap_oop = oopDesc::load_heap_oop(p);
1540 if (!oopDesc::is_null(heap_oop)) {
1541 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1542 assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
1543 }
1544 }
1545 template <class T> void assert_nothing(T *p) {}
1546
1547 #else
1548 template <class T> void assert_is_in(T *p) {}
1549 template <class T> void assert_is_in_closed_subset(T *p) {}
1550 template <class T> void assert_is_in_reserved(T *p) {}
1551 template <class T> void assert_nothing(T *p) {}
1552 #endif // ASSERT
1553
1554 //
1555 // Macros that iterate over areas of oops which are specialized on type of
1556 // oop pointer either narrow or wide, depending on UseCompressedOops
1557 //
1558 // Parameters are:
1559 // T - type of oop to point to (either oop or narrowOop)
1560 // start_p - starting pointer for region to iterate over
1561 // count - number of oops or narrowOops to iterate over
1562 // do_oop - action to perform on each oop (it's arbitrary C code which
1563 // makes it more efficient to put in a macro rather than making
1564 // it a template function)
1565 // assert_fn - assert function which is template function because performance
1566 // doesn't matter when enabled.
1567 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
1568 T, start_p, count, do_oop, \
1569 assert_fn) \
1570 { \
1571 T* p = (T*)(start_p); \
1572 T* const end = p + (count); \
1573 while (p < end) { \
1574 (assert_fn)(p); \
1575 do_oop; \
1576 ++p; \
1577 } \
1578 }
1579
1580 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
1581 T, start_p, count, do_oop, \
1582 assert_fn) \
1583 { \
1584 T* const start = (T*)(start_p); \
1585 T* p = start + (count); \
1586 while (start < p) { \
1587 --p; \
1588 (assert_fn)(p); \
1589 do_oop; \
1590 } \
1591 }
1592
1593 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
1594 T, start_p, count, low, high, \
1595 do_oop, assert_fn) \
1596 { \
1597 T* const l = (T*)(low); \
1598 T* const h = (T*)(high); \
1599 assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
1600 mask_bits((intptr_t)h, sizeof(T)-1) == 0, \
1601 "bounded region must be properly aligned"); \
1602 T* p = (T*)(start_p); \
1603 T* end = p + (count); \
1604 if (p < l) p = l; \
1605 if (end > h) end = h; \
1606 while (p < end) { \
1607 (assert_fn)(p); \
1608 do_oop; \
1609 ++p; \
1610 } \
1611 }
1612
1613
1614 // The following macros call specialized macros, passing either oop or
1615 // narrowOop as the specialization type. These test the UseCompressedOops
1616 // flag.
1617 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \
1618 { \
1619 /* Compute oopmap block range. The common case \
1620 is nonstatic_oop_map_size == 1. */ \
1621 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1622 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1623 if (UseCompressedOops) { \
1624 while (map < end_map) { \
1625 InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
1626 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1627 do_oop, assert_fn) \
1628 ++map; \
1629 } \
1630 } else { \
1631 while (map < end_map) { \
1632 InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
1633 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1634 do_oop, assert_fn) \
1635 ++map; \
1636 } \
1637 } \
1638 }
1639
1640 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \
1641 { \
1642 OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \
1643 OopMapBlock* map = start_map + nonstatic_oop_map_count(); \
1644 if (UseCompressedOops) { \
1645 while (start_map < map) { \
1646 --map; \
1647 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \
1648 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1649 do_oop, assert_fn) \
1650 } \
1651 } else { \
1652 while (start_map < map) { \
1653 --map; \
1654 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \
1655 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1656 do_oop, assert_fn) \
1657 } \
1658 } \
1659 }
1660
1661 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \
1662 assert_fn) \
1663 { \
1664 /* Compute oopmap block range. The common case is \
1665 nonstatic_oop_map_size == 1, so we accept the \
1666 usually non-existent extra overhead of examining \
1667 all the maps. */ \
1668 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1669 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1670 if (UseCompressedOops) { \
1671 while (map < end_map) { \
1672 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
1673 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1674 low, high, \
1675 do_oop, assert_fn) \
1676 ++map; \
1677 } \
1678 } else { \
1679 while (map < end_map) { \
1680 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
1681 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1682 low, high, \
1683 do_oop, assert_fn) \
1684 ++map; \
1685 } \
1686 } \
1687 }
1688
1689 void instanceKlass::oop_follow_contents(oop obj) {
1690 assert(obj != NULL, "can't follow the content of NULL object");
1691 obj->follow_header();
1692 InstanceKlass_OOP_MAP_ITERATE( \
1693 obj, \
1694 MarkSweep::mark_and_push(p), \
1695 assert_is_in_closed_subset)
1696 }
1697
1698 #ifndef SERIALGC
1699 void instanceKlass::oop_follow_contents(ParCompactionManager* cm,
1700 oop obj) {
1701 assert(obj != NULL, "can't follow the content of NULL object");
1702 obj->follow_header(cm);
1703 InstanceKlass_OOP_MAP_ITERATE( \
1704 obj, \
1705 PSParallelCompact::mark_and_push(cm, p), \
1706 assert_is_in)
1707 }
1708 #endif // SERIALGC
1709
1710 // closure's do_header() method dicates whether the given closure should be
1711 // applied to the klass ptr in the object header.
1712
1713 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
1714 \
1715 int instanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
1716 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
1717 /* header */ \
1718 if (closure->do_header()) { \
1719 obj->oop_iterate_header(closure); \
1720 } \
1721 InstanceKlass_OOP_MAP_ITERATE( \
1722 obj, \
1723 SpecializationStats:: \
1724 record_do_oop_call##nv_suffix(SpecializationStats::ik); \
1725 (closure)->do_oop##nv_suffix(p), \
1726 assert_is_in_closed_subset) \
1727 return size_helper(); \
1728 }
1729
1730 #ifndef SERIALGC
1731 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
1732 \
1733 int instanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \
1734 OopClosureType* closure) { \
1735 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
1736 /* header */ \
1737 if (closure->do_header()) { \
1738 obj->oop_iterate_header(closure); \
1739 } \
1740 /* instance variables */ \
1741 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
1742 obj, \
1743 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
1744 (closure)->do_oop##nv_suffix(p), \
1745 assert_is_in_closed_subset) \
1746 return size_helper(); \
1747 }
1748 #endif // !SERIALGC
1749
1750 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
1751 \
1752 int instanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \
1753 OopClosureType* closure, \
1754 MemRegion mr) { \
1755 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
1756 if (closure->do_header()) { \
1757 obj->oop_iterate_header(closure, mr); \
1758 } \
1759 InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
1760 obj, mr.start(), mr.end(), \
1761 (closure)->do_oop##nv_suffix(p), \
1762 assert_is_in_closed_subset) \
1763 return size_helper(); \
1764 }
1765
1766 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
1767 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
1768 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
1769 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
1770 #ifndef SERIALGC
1771 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
1772 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
1773 #endif // !SERIALGC
1774
1775 int instanceKlass::oop_adjust_pointers(oop obj) {
1776 int size = size_helper();
1777 InstanceKlass_OOP_MAP_ITERATE( \
1778 obj, \
1779 MarkSweep::adjust_pointer(p), \
1780 assert_is_in)
1781 obj->adjust_header();
1782 return size;
1783 }
1784
1785 #ifndef SERIALGC
1786 void instanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
1787 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
1788 obj, \
1789 if (PSScavenge::should_scavenge(p)) { \
1790 pm->claim_or_forward_depth(p); \
1791 }, \
1792 assert_nothing )
1793 }
1794
1795 int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
1796 InstanceKlass_OOP_MAP_ITERATE( \
1797 obj, \
1798 PSParallelCompact::adjust_pointer(p), \
1799 assert_nothing)
1800 return size_helper();
1801 }
1802
1803 #endif // SERIALGC
1804
1805 // This klass is alive but the implementor link is not followed/updated.
1806 // Subklass and sibling links are handled by Klass::follow_weak_klass_links
1807
1808 void instanceKlass::follow_weak_klass_links(
1809 BoolObjectClosure* is_alive, OopClosure* keep_alive) {
1810 assert(is_alive->do_object_b(as_klassOop()), "this oop should be live");
1811 if (ClassUnloading) {
1812 for (int i = 0; i < implementors_limit; i++) {
1813 klassOop impl = _implementors[i];
1814 if (impl == NULL) break; // no more in the list
1815 if (!is_alive->do_object_b(impl)) {
1816 // remove this guy from the list by overwriting him with the tail
1817 int lasti = --_nof_implementors;
1818 assert(lasti >= i && lasti < implementors_limit, "just checking");
1819 _implementors[i] = _implementors[lasti];
1820 _implementors[lasti] = NULL;
1821 --i; // rerun the loop at this index
1822 }
1823 }
1824 } else {
1825 for (int i = 0; i < implementors_limit; i++) {
1826 keep_alive->do_oop(&adr_implementors()[i]);
1827 }
1828 }
1829 Klass::follow_weak_klass_links(is_alive, keep_alive);
1830 }
1831
1832 void instanceKlass::remove_unshareable_info() {
1833 Klass::remove_unshareable_info();
1834 init_implementor();
1835 }
1836
1837 static void clear_all_breakpoints(methodOop m) {
1838 m->clear_all_breakpoints();
1839 }
1840
1841 void instanceKlass::release_C_heap_structures() {
1842 // Deallocate oop map cache
1843 if (_oop_map_cache != NULL) {
1844 delete _oop_map_cache;
1845 _oop_map_cache = NULL;
1846 }
1847
1848 // Deallocate JNI identifiers for jfieldIDs
1849 JNIid::deallocate(jni_ids());
1850 set_jni_ids(NULL);
1851
1852 jmethodID* jmeths = methods_jmethod_ids_acquire();
1853 if (jmeths != (jmethodID*)NULL) {
1854 release_set_methods_jmethod_ids(NULL);
1855 FreeHeap(jmeths);
1856 }
1857
1858 int* indices = methods_cached_itable_indices_acquire();
1859 if (indices != (int*)NULL) {
1860 release_set_methods_cached_itable_indices(NULL);
1861 FreeHeap(indices);
1862 }
1863
1864 // release dependencies
1865 nmethodBucket* b = _dependencies;
1866 _dependencies = NULL;
1867 while (b != NULL) {
1868 nmethodBucket* next = b->next();
1869 delete b;
1870 b = next;
1871 }
1872
1873 // Deallocate breakpoint records
1874 if (breakpoints() != 0x0) {
1875 methods_do(clear_all_breakpoints);
1876 assert(breakpoints() == 0x0, "should have cleared breakpoints");
1877 }
1878
1879 // deallocate information about previous versions
1880 if (_previous_versions != NULL) {
1881 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
1882 PreviousVersionNode * pv_node = _previous_versions->at(i);
1883 delete pv_node;
1884 }
1885 delete _previous_versions;
1886 _previous_versions = NULL;
1887 }
1888
1889 // deallocate the cached class file
1890 if (_cached_class_file_bytes != NULL) {
1891 os::free(_cached_class_file_bytes);
1892 _cached_class_file_bytes = NULL;
1893 _cached_class_file_len = 0;
1894 }
1895
1896 // Decrement symbol reference counts associated with the unloaded class.
1897 if (_name != NULL) _name->decrement_refcount();
1898 // unreference array name derived from this class name (arrays of an unloaded
1899 // class can't be referenced anymore).
1900 if (_array_name != NULL) _array_name->decrement_refcount();
1901 if (_source_file_name != NULL) _source_file_name->decrement_refcount();
1902 if (_source_debug_extension != NULL) _source_debug_extension->decrement_refcount();
1903 // walk constant pool and decrement symbol reference counts
1904 _constants->unreference_symbols();
1905 }
1906
1907 void instanceKlass::set_source_file_name(Symbol* n) {
1908 _source_file_name = n;
1909 if (_source_file_name != NULL) _source_file_name->increment_refcount();
1910 }
1911
1912 void instanceKlass::set_source_debug_extension(Symbol* n) {
1913 _source_debug_extension = n;
1914 if (_source_debug_extension != NULL) _source_debug_extension->increment_refcount();
1915 }
1916
1917 address instanceKlass::static_field_addr(int offset) {
1918 return (address)(offset + instanceMirrorKlass::offset_of_static_fields() + (intptr_t)java_mirror());
1919 }
1920
1921
1922 const char* instanceKlass::signature_name() const {
1923 const char* src = (const char*) (name()->as_C_string());
1924 const int src_length = (int)strlen(src);
1925 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
1926 int src_index = 0;
1927 int dest_index = 0;
1928 dest[dest_index++] = 'L';
1929 while (src_index < src_length) {
1930 dest[dest_index++] = src[src_index++];
1931 }
1932 dest[dest_index++] = ';';
1933 dest[dest_index] = '\0';
1934 return dest;
1935 }
1936
1937 // different verisons of is_same_class_package
1938 bool instanceKlass::is_same_class_package(klassOop class2) {
1939 klassOop class1 = as_klassOop();
1940 oop classloader1 = instanceKlass::cast(class1)->class_loader();
1941 Symbol* classname1 = Klass::cast(class1)->name();
1942
1943 if (Klass::cast(class2)->oop_is_objArray()) {
1944 class2 = objArrayKlass::cast(class2)->bottom_klass();
1945 }
1946 oop classloader2;
1947 if (Klass::cast(class2)->oop_is_instance()) {
1948 classloader2 = instanceKlass::cast(class2)->class_loader();
1949 } else {
1950 assert(Klass::cast(class2)->oop_is_typeArray(), "should be type array");
1951 classloader2 = NULL;
1952 }
1953 Symbol* classname2 = Klass::cast(class2)->name();
1954
1955 return instanceKlass::is_same_class_package(classloader1, classname1,
1956 classloader2, classname2);
1957 }
1958
1959 bool instanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
1960 klassOop class1 = as_klassOop();
1961 oop classloader1 = instanceKlass::cast(class1)->class_loader();
1962 Symbol* classname1 = Klass::cast(class1)->name();
1963
1964 return instanceKlass::is_same_class_package(classloader1, classname1,
1965 classloader2, classname2);
1966 }
1967
1968 // return true if two classes are in the same package, classloader
1969 // and classname information is enough to determine a class's package
1970 bool instanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
1971 oop class_loader2, Symbol* class_name2) {
1972 if (class_loader1 != class_loader2) {
1973 return false;
1974 } else if (class_name1 == class_name2) {
1975 return true; // skip painful bytewise comparison
1976 } else {
1977 ResourceMark rm;
1978
1979 // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
1980 // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
1981 // Otherwise, we just compare jbyte values between the strings.
1982 const jbyte *name1 = class_name1->base();
1983 const jbyte *name2 = class_name2->base();
1984
1985 const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
1986 const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
1987
1988 if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
1989 // One of the two doesn't have a package. Only return true
1990 // if the other one also doesn't have a package.
1991 return last_slash1 == last_slash2;
1992 } else {
1993 // Skip over '['s
1994 if (*name1 == '[') {
1995 do {
1996 name1++;
1997 } while (*name1 == '[');
1998 if (*name1 != 'L') {
1999 // Something is terribly wrong. Shouldn't be here.
2000 return false;
2001 }
2002 }
2003 if (*name2 == '[') {
2004 do {
2005 name2++;
2006 } while (*name2 == '[');
2007 if (*name2 != 'L') {
2008 // Something is terribly wrong. Shouldn't be here.
2009 return false;
2010 }
2011 }
2012
2013 // Check that package part is identical
2014 int length1 = last_slash1 - name1;
2015 int length2 = last_slash2 - name2;
2016
2017 return UTF8::equal(name1, length1, name2, length2);
2018 }
2019 }
2020 }
2021
2022 // Returns true iff super_method can be overridden by a method in targetclassname
2023 // See JSL 3rd edition 8.4.6.1
2024 // Assumes name-signature match
2025 // "this" is instanceKlass of super_method which must exist
2026 // note that the instanceKlass of the method in the targetclassname has not always been created yet
2027 bool instanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2028 // Private methods can not be overridden
2029 if (super_method->is_private()) {
2030 return false;
2031 }
2032 // If super method is accessible, then override
2033 if ((super_method->is_protected()) ||
2034 (super_method->is_public())) {
2035 return true;
2036 }
2037 // Package-private methods are not inherited outside of package
2038 assert(super_method->is_package_private(), "must be package private");
2039 return(is_same_class_package(targetclassloader(), targetclassname));
2040 }
2041
2042 /* defined for now in jvm.cpp, for historical reasons *--
2043 klassOop instanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2044 Symbol*& simple_name_result, TRAPS) {
2045 ...
2046 }
2047 */
2048
2049 // tell if two classes have the same enclosing class (at package level)
2050 bool instanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2051 klassOop class2_oop, TRAPS) {
2052 if (class2_oop == class1->as_klassOop()) return true;
2053 if (!Klass::cast(class2_oop)->oop_is_instance()) return false;
2054 instanceKlassHandle class2(THREAD, class2_oop);
2055
2056 // must be in same package before we try anything else
2057 if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2058 return false;
2059
2060 // As long as there is an outer1.getEnclosingClass,
2061 // shift the search outward.
2062 instanceKlassHandle outer1 = class1;
2063 for (;;) {
2064 // As we walk along, look for equalities between outer1 and class2.
2065 // Eventually, the walks will terminate as outer1 stops
2066 // at the top-level class around the original class.
2067 bool ignore_inner_is_member;
2068 klassOop next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2069 CHECK_false);
2070 if (next == NULL) break;
2071 if (next == class2()) return true;
2072 outer1 = instanceKlassHandle(THREAD, next);
2073 }
2074
2075 // Now do the same for class2.
2076 instanceKlassHandle outer2 = class2;
2077 for (;;) {
2078 bool ignore_inner_is_member;
2079 klassOop next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2080 CHECK_false);
2081 if (next == NULL) break;
2082 // Might as well check the new outer against all available values.
2083 if (next == class1()) return true;
2084 if (next == outer1()) return true;
2085 outer2 = instanceKlassHandle(THREAD, next);
2086 }
2087
2088 // If by this point we have not found an equality between the
2089 // two classes, we know they are in separate package members.
2090 return false;
2091 }
2092
2093
2094 jint instanceKlass::compute_modifier_flags(TRAPS) const {
2095 klassOop k = as_klassOop();
2096 jint access = access_flags().as_int();
2097
2098 // But check if it happens to be member class.
2099 typeArrayOop inner_class_list = inner_classes();
2100 int length = (inner_class_list == NULL) ? 0 : inner_class_list->length();
2101 assert (length % instanceKlass::inner_class_next_offset == 0, "just checking");
2102 if (length > 0) {
2103 typeArrayHandle inner_class_list_h(THREAD, inner_class_list);
2104 instanceKlassHandle ik(THREAD, k);
2105 for (int i = 0; i < length; i += instanceKlass::inner_class_next_offset) {
2106 int ioff = inner_class_list_h->ushort_at(
2107 i + instanceKlass::inner_class_inner_class_info_offset);
2108
2109 // Inner class attribute can be zero, skip it.
2110 // Strange but true: JVM spec. allows null inner class refs.
2111 if (ioff == 0) continue;
2112
2113 // only look at classes that are already loaded
2114 // since we are looking for the flags for our self.
2115 Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2116 if ((ik->name() == inner_name)) {
2117 // This is really a member class.
2118 access = inner_class_list_h->ushort_at(i + instanceKlass::inner_class_access_flags_offset);
2119 break;
2120 }
2121 }
2122 }
2123 // Remember to strip ACC_SUPER bit
2124 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2125 }
2126
2127 jint instanceKlass::jvmti_class_status() const {
2128 jint result = 0;
2129
2130 if (is_linked()) {
2131 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2132 }
2133
2134 if (is_initialized()) {
2135 assert(is_linked(), "Class status is not consistent");
2136 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2137 }
2138 if (is_in_error_state()) {
2139 result |= JVMTI_CLASS_STATUS_ERROR;
2140 }
2141 return result;
2142 }
2143
2144 methodOop instanceKlass::method_at_itable(klassOop holder, int index, TRAPS) {
2145 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2146 int method_table_offset_in_words = ioe->offset()/wordSize;
2147 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2148 / itableOffsetEntry::size();
2149
2150 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2151 // If the interface isn't implemented by the receiver class,
2152 // the VM should throw IncompatibleClassChangeError.
2153 if (cnt >= nof_interfaces) {
2154 THROW_0(vmSymbols::java_lang_IncompatibleClassChangeError());
2155 }
2156
2157 klassOop ik = ioe->interface_klass();
2158 if (ik == holder) break;
2159 }
2160
2161 itableMethodEntry* ime = ioe->first_method_entry(as_klassOop());
2162 methodOop m = ime[index].method();
2163 if (m == NULL) {
2164 THROW_0(vmSymbols::java_lang_AbstractMethodError());
2165 }
2166 return m;
2167 }
2168
2169 // On-stack replacement stuff
2170 void instanceKlass::add_osr_nmethod(nmethod* n) {
2171 // only one compilation can be active
2172 NEEDS_CLEANUP
2173 // This is a short non-blocking critical region, so the no safepoint check is ok.
2174 OsrList_lock->lock_without_safepoint_check();
2175 assert(n->is_osr_method(), "wrong kind of nmethod");
2176 n->set_osr_link(osr_nmethods_head());
2177 set_osr_nmethods_head(n);
2178 // Raise the highest osr level if necessary
2179 if (TieredCompilation) {
2180 methodOop m = n->method();
2181 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2182 }
2183 // Remember to unlock again
2184 OsrList_lock->unlock();
2185
2186 // Get rid of the osr methods for the same bci that have lower levels.
2187 if (TieredCompilation) {
2188 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2189 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2190 if (inv != NULL && inv->is_in_use()) {
2191 inv->make_not_entrant();
2192 }
2193 }
2194 }
2195 }
2196
2197
2198 void instanceKlass::remove_osr_nmethod(nmethod* n) {
2199 // This is a short non-blocking critical region, so the no safepoint check is ok.
2200 OsrList_lock->lock_without_safepoint_check();
2201 assert(n->is_osr_method(), "wrong kind of nmethod");
2202 nmethod* last = NULL;
2203 nmethod* cur = osr_nmethods_head();
2204 int max_level = CompLevel_none; // Find the max comp level excluding n
2205 methodOop m = n->method();
2206 // Search for match
2207 while(cur != NULL && cur != n) {
2208 if (TieredCompilation) {
2209 // Find max level before n
2210 max_level = MAX2(max_level, cur->comp_level());
2211 }
2212 last = cur;
2213 cur = cur->osr_link();
2214 }
2215 nmethod* next = NULL;
2216 if (cur == n) {
2217 next = cur->osr_link();
2218 if (last == NULL) {
2219 // Remove first element
2220 set_osr_nmethods_head(next);
2221 } else {
2222 last->set_osr_link(next);
2223 }
2224 }
2225 n->set_osr_link(NULL);
2226 if (TieredCompilation) {
2227 cur = next;
2228 while (cur != NULL) {
2229 // Find max level after n
2230 max_level = MAX2(max_level, cur->comp_level());
2231 cur = cur->osr_link();
2232 }
2233 m->set_highest_osr_comp_level(max_level);
2234 }
2235 // Remember to unlock again
2236 OsrList_lock->unlock();
2237 }
2238
2239 nmethod* instanceKlass::lookup_osr_nmethod(const methodOop m, int bci, int comp_level, bool match_level) const {
2240 // This is a short non-blocking critical region, so the no safepoint check is ok.
2241 OsrList_lock->lock_without_safepoint_check();
2242 nmethod* osr = osr_nmethods_head();
2243 nmethod* best = NULL;
2244 while (osr != NULL) {
2245 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2246 // There can be a time when a c1 osr method exists but we are waiting
2247 // for a c2 version. When c2 completes its osr nmethod we will trash
2248 // the c1 version and only be able to find the c2 version. However
2249 // while we overflow in the c1 code at back branches we don't want to
2250 // try and switch to the same code as we are already running
2251
2252 if (osr->method() == m &&
2253 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2254 if (match_level) {
2255 if (osr->comp_level() == comp_level) {
2256 // Found a match - return it.
2257 OsrList_lock->unlock();
2258 return osr;
2259 }
2260 } else {
2261 if (best == NULL || (osr->comp_level() > best->comp_level())) {
2262 if (osr->comp_level() == CompLevel_highest_tier) {
2263 // Found the best possible - return it.
2264 OsrList_lock->unlock();
2265 return osr;
2266 }
2267 best = osr;
2268 }
2269 }
2270 }
2271 osr = osr->osr_link();
2272 }
2273 OsrList_lock->unlock();
2274 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2275 return best;
2276 }
2277 return NULL;
2278 }
2279
2280 // -----------------------------------------------------------------------------------------------------
2281 #ifndef PRODUCT
2282
2283 // Printing
2284
2285 #define BULLET " - "
2286
2287 void FieldPrinter::do_field(fieldDescriptor* fd) {
2288 _st->print(BULLET);
2289 if (_obj == NULL) {
2290 fd->print_on(_st);
2291 _st->cr();
2292 } else {
2293 fd->print_on_for(_st, _obj);
2294 _st->cr();
2295 }
2296 }
2297
2298
2299 void instanceKlass::oop_print_on(oop obj, outputStream* st) {
2300 Klass::oop_print_on(obj, st);
2301
2302 if (as_klassOop() == SystemDictionary::String_klass()) {
2303 typeArrayOop value = java_lang_String::value(obj);
2304 juint offset = java_lang_String::offset(obj);
2305 juint length = java_lang_String::length(obj);
2306 if (value != NULL &&
2307 value->is_typeArray() &&
2308 offset <= (juint) value->length() &&
2309 offset + length <= (juint) value->length()) {
2310 st->print(BULLET"string: ");
2311 Handle h_obj(obj);
2312 java_lang_String::print(h_obj, st);
2313 st->cr();
2314 if (!WizardMode) return; // that is enough
2315 }
2316 }
2317
2318 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
2319 FieldPrinter print_field(st, obj);
2320 do_nonstatic_fields(&print_field);
2321
2322 if (as_klassOop() == SystemDictionary::Class_klass()) {
2323 st->print(BULLET"signature: ");
2324 java_lang_Class::print_signature(obj, st);
2325 st->cr();
2326 klassOop mirrored_klass = java_lang_Class::as_klassOop(obj);
2327 st->print(BULLET"fake entry for mirror: ");
2328 mirrored_klass->print_value_on(st);
2329 st->cr();
2330 st->print(BULLET"fake entry resolved_constructor: ");
2331 methodOop ctor = java_lang_Class::resolved_constructor(obj);
2332 ctor->print_value_on(st);
2333 klassOop array_klass = java_lang_Class::array_klass(obj);
2334 st->cr();
2335 st->print(BULLET"fake entry for array: ");
2336 array_klass->print_value_on(st);
2337 st->cr();
2338 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
2339 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
2340 klassOop real_klass = java_lang_Class::as_klassOop(obj);
2341 if (real_klass != NULL && real_klass->klass_part()->oop_is_instance()) {
2342 instanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
2343 }
2344 } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
2345 st->print(BULLET"signature: ");
2346 java_lang_invoke_MethodType::print_signature(obj, st);
2347 st->cr();
2348 }
2349 }
2350
2351 #endif //PRODUCT
2352
2353 void instanceKlass::oop_print_value_on(oop obj, outputStream* st) {
2354 st->print("a ");
2355 name()->print_value_on(st);
2356 obj->print_address_on(st);
2357 if (as_klassOop() == SystemDictionary::String_klass()
2358 && java_lang_String::value(obj) != NULL) {
2359 ResourceMark rm;
2360 int len = java_lang_String::length(obj);
2361 int plen = (len < 24 ? len : 12);
2362 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
2363 st->print(" = \"%s\"", str);
2364 if (len > plen)
2365 st->print("...[%d]", len);
2366 } else if (as_klassOop() == SystemDictionary::Class_klass()) {
2367 klassOop k = java_lang_Class::as_klassOop(obj);
2368 st->print(" = ");
2369 if (k != NULL) {
2370 k->print_value_on(st);
2371 } else {
2372 const char* tname = type2name(java_lang_Class::primitive_type(obj));
2373 st->print("%s", tname ? tname : "type?");
2374 }
2375 } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
2376 st->print(" = ");
2377 java_lang_invoke_MethodType::print_signature(obj, st);
2378 } else if (java_lang_boxing_object::is_instance(obj)) {
2379 st->print(" = ");
2380 java_lang_boxing_object::print(obj, st);
2381 }
2382 }
2383
2384 const char* instanceKlass::internal_name() const {
2385 return external_name();
2386 }
2387
2388 // Verification
2389
2390 class VerifyFieldClosure: public OopClosure {
2391 protected:
2392 template <class T> void do_oop_work(T* p) {
2393 guarantee(Universe::heap()->is_in_closed_subset(p), "should be in heap");
2394 oop obj = oopDesc::load_decode_heap_oop(p);
2395 if (!obj->is_oop_or_null()) {
2396 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
2397 Universe::print();
2398 guarantee(false, "boom");
2399 }
2400 }
2401 public:
2402 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
2403 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
2404 };
2405
2406 void instanceKlass::oop_verify_on(oop obj, outputStream* st) {
2407 Klass::oop_verify_on(obj, st);
2408 VerifyFieldClosure blk;
2409 oop_oop_iterate(obj, &blk);
2410 }
2411
2412 // JNIid class for jfieldIDs only
2413 // Note to reviewers:
2414 // These JNI functions are just moved over to column 1 and not changed
2415 // in the compressed oops workspace.
2416 JNIid::JNIid(klassOop holder, int offset, JNIid* next) {
2417 _holder = holder;
2418 _offset = offset;
2419 _next = next;
2420 debug_only(_is_static_field_id = false;)
2421 }
2422
2423
2424 JNIid* JNIid::find(int offset) {
2425 JNIid* current = this;
2426 while (current != NULL) {
2427 if (current->offset() == offset) return current;
2428 current = current->next();
2429 }
2430 return NULL;
2431 }
2432
2433 void JNIid::oops_do(OopClosure* f) {
2434 for (JNIid* cur = this; cur != NULL; cur = cur->next()) {
2435 f->do_oop(cur->holder_addr());
2436 }
2437 }
2438
2439 void JNIid::deallocate(JNIid* current) {
2440 while (current != NULL) {
2441 JNIid* next = current->next();
2442 delete current;
2443 current = next;
2444 }
2445 }
2446
2447
2448 void JNIid::verify(klassOop holder) {
2449 int first_field_offset = instanceMirrorKlass::offset_of_static_fields();
2450 int end_field_offset;
2451 end_field_offset = first_field_offset + (instanceKlass::cast(holder)->static_field_size() * wordSize);
2452
2453 JNIid* current = this;
2454 while (current != NULL) {
2455 guarantee(current->holder() == holder, "Invalid klass in JNIid");
2456 #ifdef ASSERT
2457 int o = current->offset();
2458 if (current->is_static_field_id()) {
2459 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
2460 }
2461 #endif
2462 current = current->next();
2463 }
2464 }
2465
2466
2467 #ifdef ASSERT
2468 void instanceKlass::set_init_state(ClassState state) {
2469 bool good_state = as_klassOop()->is_shared() ? (_init_state <= state)
2470 : (_init_state < state);
2471 assert(good_state || state == allocated, "illegal state transition");
2472 _init_state = state;
2473 }
2474 #endif
2475
2476
2477 // RedefineClasses() support for previous versions:
2478
2479 // Add an information node that contains weak references to the
2480 // interesting parts of the previous version of the_class.
2481 // This is also where we clean out any unused weak references.
2482 // Note that while we delete nodes from the _previous_versions
2483 // array, we never delete the array itself until the klass is
2484 // unloaded. The has_been_redefined() query depends on that fact.
2485 //
2486 void instanceKlass::add_previous_version(instanceKlassHandle ikh,
2487 BitMap* emcp_methods, int emcp_method_count) {
2488 assert(Thread::current()->is_VM_thread(),
2489 "only VMThread can add previous versions");
2490
2491 if (_previous_versions == NULL) {
2492 // This is the first previous version so make some space.
2493 // Start with 2 elements under the assumption that the class
2494 // won't be redefined much.
2495 _previous_versions = new (ResourceObj::C_HEAP)
2496 GrowableArray<PreviousVersionNode *>(2, true);
2497 }
2498
2499 // RC_TRACE macro has an embedded ResourceMark
2500 RC_TRACE(0x00000100, ("adding previous version ref for %s @%d, EMCP_cnt=%d",
2501 ikh->external_name(), _previous_versions->length(), emcp_method_count));
2502 constantPoolHandle cp_h(ikh->constants());
2503 jobject cp_ref;
2504 if (cp_h->is_shared()) {
2505 // a shared ConstantPool requires a regular reference; a weak
2506 // reference would be collectible
2507 cp_ref = JNIHandles::make_global(cp_h);
2508 } else {
2509 cp_ref = JNIHandles::make_weak_global(cp_h);
2510 }
2511 PreviousVersionNode * pv_node = NULL;
2512 objArrayOop old_methods = ikh->methods();
2513
2514 if (emcp_method_count == 0) {
2515 // non-shared ConstantPool gets a weak reference
2516 pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), NULL);
2517 RC_TRACE(0x00000400,
2518 ("add: all methods are obsolete; flushing any EMCP weak refs"));
2519 } else {
2520 int local_count = 0;
2521 GrowableArray<jweak>* method_refs = new (ResourceObj::C_HEAP)
2522 GrowableArray<jweak>(emcp_method_count, true);
2523 for (int i = 0; i < old_methods->length(); i++) {
2524 if (emcp_methods->at(i)) {
2525 // this old method is EMCP so save a weak ref
2526 methodOop old_method = (methodOop) old_methods->obj_at(i);
2527 methodHandle old_method_h(old_method);
2528 jweak method_ref = JNIHandles::make_weak_global(old_method_h);
2529 method_refs->append(method_ref);
2530 if (++local_count >= emcp_method_count) {
2531 // no more EMCP methods so bail out now
2532 break;
2533 }
2534 }
2535 }
2536 // non-shared ConstantPool gets a weak reference
2537 pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), method_refs);
2538 }
2539
2540 _previous_versions->append(pv_node);
2541
2542 // Using weak references allows the interesting parts of previous
2543 // classes to be GC'ed when they are no longer needed. Since the
2544 // caller is the VMThread and we are at a safepoint, this is a good
2545 // time to clear out unused weak references.
2546
2547 RC_TRACE(0x00000400, ("add: previous version length=%d",
2548 _previous_versions->length()));
2549
2550 // skip the last entry since we just added it
2551 for (int i = _previous_versions->length() - 2; i >= 0; i--) {
2552 // check the previous versions array for a GC'ed weak refs
2553 pv_node = _previous_versions->at(i);
2554 cp_ref = pv_node->prev_constant_pool();
2555 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
2556 if (cp_ref == NULL) {
2557 delete pv_node;
2558 _previous_versions->remove_at(i);
2559 // Since we are traversing the array backwards, we don't have to
2560 // do anything special with the index.
2561 continue; // robustness
2562 }
2563
2564 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2565 if (cp == NULL) {
2566 // this entry has been GC'ed so remove it
2567 delete pv_node;
2568 _previous_versions->remove_at(i);
2569 // Since we are traversing the array backwards, we don't have to
2570 // do anything special with the index.
2571 continue;
2572 } else {
2573 RC_TRACE(0x00000400, ("add: previous version @%d is alive", i));
2574 }
2575
2576 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2577 if (method_refs != NULL) {
2578 RC_TRACE(0x00000400, ("add: previous methods length=%d",
2579 method_refs->length()));
2580 for (int j = method_refs->length() - 1; j >= 0; j--) {
2581 jweak method_ref = method_refs->at(j);
2582 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
2583 if (method_ref == NULL) {
2584 method_refs->remove_at(j);
2585 // Since we are traversing the array backwards, we don't have to
2586 // do anything special with the index.
2587 continue; // robustness
2588 }
2589
2590 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2591 if (method == NULL || emcp_method_count == 0) {
2592 // This method entry has been GC'ed or the current
2593 // RedefineClasses() call has made all methods obsolete
2594 // so remove it.
2595 JNIHandles::destroy_weak_global(method_ref);
2596 method_refs->remove_at(j);
2597 } else {
2598 // RC_TRACE macro has an embedded ResourceMark
2599 RC_TRACE(0x00000400,
2600 ("add: %s(%s): previous method @%d in version @%d is alive",
2601 method->name()->as_C_string(), method->signature()->as_C_string(),
2602 j, i));
2603 }
2604 }
2605 }
2606 }
2607
2608 int obsolete_method_count = old_methods->length() - emcp_method_count;
2609
2610 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
2611 _previous_versions->length() > 1) {
2612 // We have a mix of obsolete and EMCP methods. If there is more
2613 // than the previous version that we just added, then we have to
2614 // clear out any matching EMCP method entries the hard way.
2615 int local_count = 0;
2616 for (int i = 0; i < old_methods->length(); i++) {
2617 if (!emcp_methods->at(i)) {
2618 // only obsolete methods are interesting
2619 methodOop old_method = (methodOop) old_methods->obj_at(i);
2620 Symbol* m_name = old_method->name();
2621 Symbol* m_signature = old_method->signature();
2622
2623 // skip the last entry since we just added it
2624 for (int j = _previous_versions->length() - 2; j >= 0; j--) {
2625 // check the previous versions array for a GC'ed weak refs
2626 pv_node = _previous_versions->at(j);
2627 cp_ref = pv_node->prev_constant_pool();
2628 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
2629 if (cp_ref == NULL) {
2630 delete pv_node;
2631 _previous_versions->remove_at(j);
2632 // Since we are traversing the array backwards, we don't have to
2633 // do anything special with the index.
2634 continue; // robustness
2635 }
2636
2637 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2638 if (cp == NULL) {
2639 // this entry has been GC'ed so remove it
2640 delete pv_node;
2641 _previous_versions->remove_at(j);
2642 // Since we are traversing the array backwards, we don't have to
2643 // do anything special with the index.
2644 continue;
2645 }
2646
2647 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2648 if (method_refs == NULL) {
2649 // We have run into a PreviousVersion generation where
2650 // all methods were made obsolete during that generation's
2651 // RedefineClasses() operation. At the time of that
2652 // operation, all EMCP methods were flushed so we don't
2653 // have to go back any further.
2654 //
2655 // A NULL method_refs is different than an empty method_refs.
2656 // We cannot infer any optimizations about older generations
2657 // from an empty method_refs for the current generation.
2658 break;
2659 }
2660
2661 for (int k = method_refs->length() - 1; k >= 0; k--) {
2662 jweak method_ref = method_refs->at(k);
2663 assert(method_ref != NULL,
2664 "weak method ref was unexpectedly cleared");
2665 if (method_ref == NULL) {
2666 method_refs->remove_at(k);
2667 // Since we are traversing the array backwards, we don't
2668 // have to do anything special with the index.
2669 continue; // robustness
2670 }
2671
2672 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2673 if (method == NULL) {
2674 // this method entry has been GC'ed so skip it
2675 JNIHandles::destroy_weak_global(method_ref);
2676 method_refs->remove_at(k);
2677 continue;
2678 }
2679
2680 if (method->name() == m_name &&
2681 method->signature() == m_signature) {
2682 // The current RedefineClasses() call has made all EMCP
2683 // versions of this method obsolete so mark it as obsolete
2684 // and remove the weak ref.
2685 RC_TRACE(0x00000400,
2686 ("add: %s(%s): flush obsolete method @%d in version @%d",
2687 m_name->as_C_string(), m_signature->as_C_string(), k, j));
2688
2689 method->set_is_obsolete();
2690 JNIHandles::destroy_weak_global(method_ref);
2691 method_refs->remove_at(k);
2692 break;
2693 }
2694 }
2695
2696 // The previous loop may not find a matching EMCP method, but
2697 // that doesn't mean that we can optimize and not go any
2698 // further back in the PreviousVersion generations. The EMCP
2699 // method for this generation could have already been GC'ed,
2700 // but there still may be an older EMCP method that has not
2701 // been GC'ed.
2702 }
2703
2704 if (++local_count >= obsolete_method_count) {
2705 // no more obsolete methods so bail out now
2706 break;
2707 }
2708 }
2709 }
2710 }
2711 } // end add_previous_version()
2712
2713
2714 // Determine if instanceKlass has a previous version.
2715 bool instanceKlass::has_previous_version() const {
2716 if (_previous_versions == NULL) {
2717 // no previous versions array so answer is easy
2718 return false;
2719 }
2720
2721 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
2722 // Check the previous versions array for an info node that hasn't
2723 // been GC'ed
2724 PreviousVersionNode * pv_node = _previous_versions->at(i);
2725
2726 jobject cp_ref = pv_node->prev_constant_pool();
2727 assert(cp_ref != NULL, "cp reference was unexpectedly cleared");
2728 if (cp_ref == NULL) {
2729 continue; // robustness
2730 }
2731
2732 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2733 if (cp != NULL) {
2734 // we have at least one previous version
2735 return true;
2736 }
2737
2738 // We don't have to check the method refs. If the constant pool has
2739 // been GC'ed then so have the methods.
2740 }
2741
2742 // all of the underlying nodes' info has been GC'ed
2743 return false;
2744 } // end has_previous_version()
2745
2746 methodOop instanceKlass::method_with_idnum(int idnum) {
2747 methodOop m = NULL;
2748 if (idnum < methods()->length()) {
2749 m = (methodOop) methods()->obj_at(idnum);
2750 }
2751 if (m == NULL || m->method_idnum() != idnum) {
2752 for (int index = 0; index < methods()->length(); ++index) {
2753 m = (methodOop) methods()->obj_at(index);
2754 if (m->method_idnum() == idnum) {
2755 return m;
2756 }
2757 }
2758 }
2759 return m;
2760 }
2761
2762
2763 // Set the annotation at 'idnum' to 'anno'.
2764 // We don't want to create or extend the array if 'anno' is NULL, since that is the
2765 // default value. However, if the array exists and is long enough, we must set NULL values.
2766 void instanceKlass::set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p) {
2767 objArrayOop md = *md_p;
2768 if (md != NULL && md->length() > idnum) {
2769 md->obj_at_put(idnum, anno);
2770 } else if (anno != NULL) {
2771 // create the array
2772 int length = MAX2(idnum+1, (int)_idnum_allocated_count);
2773 md = oopFactory::new_system_objArray(length, Thread::current());
2774 if (*md_p != NULL) {
2775 // copy the existing entries
2776 for (int index = 0; index < (*md_p)->length(); index++) {
2777 md->obj_at_put(index, (*md_p)->obj_at(index));
2778 }
2779 }
2780 set_annotations(md, md_p);
2781 md->obj_at_put(idnum, anno);
2782 } // if no array and idnum isn't included there is nothing to do
2783 }
2784
2785 // Construct a PreviousVersionNode entry for the array hung off
2786 // the instanceKlass.
2787 PreviousVersionNode::PreviousVersionNode(jobject prev_constant_pool,
2788 bool prev_cp_is_weak, GrowableArray<jweak>* prev_EMCP_methods) {
2789
2790 _prev_constant_pool = prev_constant_pool;
2791 _prev_cp_is_weak = prev_cp_is_weak;
2792 _prev_EMCP_methods = prev_EMCP_methods;
2793 }
2794
2795
2796 // Destroy a PreviousVersionNode
2797 PreviousVersionNode::~PreviousVersionNode() {
2798 if (_prev_constant_pool != NULL) {
2799 if (_prev_cp_is_weak) {
2800 JNIHandles::destroy_weak_global(_prev_constant_pool);
2801 } else {
2802 JNIHandles::destroy_global(_prev_constant_pool);
2803 }
2804 }
2805
2806 if (_prev_EMCP_methods != NULL) {
2807 for (int i = _prev_EMCP_methods->length() - 1; i >= 0; i--) {
2808 jweak method_ref = _prev_EMCP_methods->at(i);
2809 if (method_ref != NULL) {
2810 JNIHandles::destroy_weak_global(method_ref);
2811 }
2812 }
2813 delete _prev_EMCP_methods;
2814 }
2815 }
2816
2817
2818 // Construct a PreviousVersionInfo entry
2819 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
2820 _prev_constant_pool_handle = constantPoolHandle(); // NULL handle
2821 _prev_EMCP_method_handles = NULL;
2822
2823 jobject cp_ref = pv_node->prev_constant_pool();
2824 assert(cp_ref != NULL, "constant pool ref was unexpectedly cleared");
2825 if (cp_ref == NULL) {
2826 return; // robustness
2827 }
2828
2829 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2830 if (cp == NULL) {
2831 // Weak reference has been GC'ed. Since the constant pool has been
2832 // GC'ed, the methods have also been GC'ed.
2833 return;
2834 }
2835
2836 // make the constantPoolOop safe to return
2837 _prev_constant_pool_handle = constantPoolHandle(cp);
2838
2839 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2840 if (method_refs == NULL) {
2841 // the instanceKlass did not have any EMCP methods
2842 return;
2843 }
2844
2845 _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
2846
2847 int n_methods = method_refs->length();
2848 for (int i = 0; i < n_methods; i++) {
2849 jweak method_ref = method_refs->at(i);
2850 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
2851 if (method_ref == NULL) {
2852 continue; // robustness
2853 }
2854
2855 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2856 if (method == NULL) {
2857 // this entry has been GC'ed so skip it
2858 continue;
2859 }
2860
2861 // make the methodOop safe to return
2862 _prev_EMCP_method_handles->append(methodHandle(method));
2863 }
2864 }
2865
2866
2867 // Destroy a PreviousVersionInfo
2868 PreviousVersionInfo::~PreviousVersionInfo() {
2869 // Since _prev_EMCP_method_handles is not C-heap allocated, we
2870 // don't have to delete it.
2871 }
2872
2873
2874 // Construct a helper for walking the previous versions array
2875 PreviousVersionWalker::PreviousVersionWalker(instanceKlass *ik) {
2876 _previous_versions = ik->previous_versions();
2877 _current_index = 0;
2878 // _hm needs no initialization
2879 _current_p = NULL;
2880 }
2881
2882
2883 // Destroy a PreviousVersionWalker
2884 PreviousVersionWalker::~PreviousVersionWalker() {
2885 // Delete the current info just in case the caller didn't walk to
2886 // the end of the previous versions list. No harm if _current_p is
2887 // already NULL.
2888 delete _current_p;
2889
2890 // When _hm is destroyed, all the Handles returned in
2891 // PreviousVersionInfo objects will be destroyed.
2892 // Also, after this destructor is finished it will be
2893 // safe to delete the GrowableArray allocated in the
2894 // PreviousVersionInfo objects.
2895 }
2896
2897
2898 // Return the interesting information for the next previous version
2899 // of the klass. Returns NULL if there are no more previous versions.
2900 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
2901 if (_previous_versions == NULL) {
2902 // no previous versions so nothing to return
2903 return NULL;
2904 }
2905
2906 delete _current_p; // cleanup the previous info for the caller
2907 _current_p = NULL; // reset to NULL so we don't delete same object twice
2908
2909 int length = _previous_versions->length();
2910
2911 while (_current_index < length) {
2912 PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
2913 PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP)
2914 PreviousVersionInfo(pv_node);
2915
2916 constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
2917 if (cp_h.is_null()) {
2918 delete pv_info;
2919
2920 // The underlying node's info has been GC'ed so try the next one.
2921 // We don't have to check the methods. If the constant pool has
2922 // GC'ed then so have the methods.
2923 continue;
2924 }
2925
2926 // Found a node with non GC'ed info so return it. The caller will
2927 // need to delete pv_info when they are done with it.
2928 _current_p = pv_info;
2929 return pv_info;
2930 }
2931
2932 // all of the underlying nodes' info has been GC'ed
2933 return NULL;
2934 } // end next_previous_version()