1 /*
2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/javaClasses.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/verifier.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "gc_implementation/shared/markSweep.inline.hpp"
32 #include "gc_interface/collectedHeap.inline.hpp"
33 #include "interpreter/oopMapCache.hpp"
34 #include "interpreter/rewriter.hpp"
35 #include "jvmtifiles/jvmti.h"
36 #include "memory/genOopClosures.inline.hpp"
37 #include "memory/oopFactory.hpp"
38 #include "memory/permGen.hpp"
39 #include "oops/fieldStreams.hpp"
40 #include "oops/instanceKlass.hpp"
41 #include "oops/instanceMirrorKlass.hpp"
42 #include "oops/instanceOop.hpp"
43 #include "oops/methodOop.hpp"
44 #include "oops/objArrayKlassKlass.hpp"
45 #include "oops/oop.inline.hpp"
46 #include "oops/symbol.hpp"
47 #include "prims/jvmtiExport.hpp"
48 #include "prims/jvmtiRedefineClassesTrace.hpp"
49 #include "runtime/fieldDescriptor.hpp"
50 #include "runtime/handles.inline.hpp"
51 #include "runtime/javaCalls.hpp"
52 #include "runtime/mutexLocker.hpp"
53 #include "services/threadService.hpp"
54 #include "utilities/dtrace.hpp"
55 #ifdef TARGET_OS_FAMILY_linux
56 # include "thread_linux.inline.hpp"
57 #endif
58 #ifdef TARGET_OS_FAMILY_solaris
59 # include "thread_solaris.inline.hpp"
60 #endif
61 #ifdef TARGET_OS_FAMILY_windows
62 # include "thread_windows.inline.hpp"
63 #endif
64 #ifdef TARGET_OS_FAMILY_bsd
65 # include "thread_bsd.inline.hpp"
66 #endif
67 #ifndef SERIALGC
68 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
69 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
70 #include "gc_implementation/g1/g1RemSet.inline.hpp"
71 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
72 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
73 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
74 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
75 #include "oops/oop.pcgc.inline.hpp"
76 #endif
77 #ifdef COMPILER1
78 #include "c1/c1_Compiler.hpp"
79 #endif
80
81 #ifdef DTRACE_ENABLED
82
83 #ifndef USDT2
84
85 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
86 char*, intptr_t, oop, intptr_t);
87 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
88 char*, intptr_t, oop, intptr_t, int);
89 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
90 char*, intptr_t, oop, intptr_t, int);
91 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
92 char*, intptr_t, oop, intptr_t, int);
93 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
94 char*, intptr_t, oop, intptr_t, int);
95 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
96 char*, intptr_t, oop, intptr_t, int);
97 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
98 char*, intptr_t, oop, intptr_t, int);
99 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
100 char*, intptr_t, oop, intptr_t, int);
101
102 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
103 { \
104 char* data = NULL; \
105 int len = 0; \
106 Symbol* name = (clss)->name(); \
107 if (name != NULL) { \
108 data = (char*)name->bytes(); \
109 len = name->utf8_length(); \
110 } \
111 HS_DTRACE_PROBE4(hotspot, class__initialization__##type, \
112 data, len, (clss)->class_loader(), thread_type); \
113 }
114
115 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
116 { \
117 char* data = NULL; \
118 int len = 0; \
119 Symbol* name = (clss)->name(); \
120 if (name != NULL) { \
121 data = (char*)name->bytes(); \
122 len = name->utf8_length(); \
123 } \
124 HS_DTRACE_PROBE5(hotspot, class__initialization__##type, \
125 data, len, (clss)->class_loader(), thread_type, wait); \
126 }
127 #else /* USDT2 */
128
129 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
130 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
131 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
132 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
133 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
134 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
135 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
136 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
137 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
138 { \
139 char* data = NULL; \
140 int len = 0; \
141 Symbol* name = (clss)->name(); \
142 if (name != NULL) { \
143 data = (char*)name->bytes(); \
144 len = name->utf8_length(); \
145 } \
146 HOTSPOT_CLASS_INITIALIZATION_##type( \
147 data, len, (clss)->class_loader(), thread_type); \
148 }
149
150 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
151 { \
152 char* data = NULL; \
153 int len = 0; \
154 Symbol* name = (clss)->name(); \
155 if (name != NULL) { \
156 data = (char*)name->bytes(); \
157 len = name->utf8_length(); \
158 } \
159 HOTSPOT_CLASS_INITIALIZATION_##type( \
160 data, len, (clss)->class_loader(), thread_type, wait); \
161 }
162 #endif /* USDT2 */
163
164 #else // ndef DTRACE_ENABLED
165
166 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
167 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
168
169 #endif // ndef DTRACE_ENABLED
170
171 bool instanceKlass::should_be_initialized() const {
172 return !is_initialized();
173 }
174
175 klassVtable* instanceKlass::vtable() const {
176 return new klassVtable(as_klassOop(), start_of_vtable(), vtable_length() / vtableEntry::size());
177 }
178
179 klassItable* instanceKlass::itable() const {
180 return new klassItable(as_klassOop());
181 }
182
183 void instanceKlass::eager_initialize(Thread *thread) {
184 if (!EagerInitialization) return;
185
186 if (this->is_not_initialized()) {
187 // abort if the the class has a class initializer
188 if (this->class_initializer() != NULL) return;
189
190 // abort if it is java.lang.Object (initialization is handled in genesis)
191 klassOop super = this->super();
192 if (super == NULL) return;
193
194 // abort if the super class should be initialized
195 if (!instanceKlass::cast(super)->is_initialized()) return;
196
197 // call body to expose the this pointer
198 instanceKlassHandle this_oop(thread, this->as_klassOop());
199 eager_initialize_impl(this_oop);
200 }
201 }
202
203
204 void instanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
205 EXCEPTION_MARK;
206 ObjectLocker ol(this_oop, THREAD);
207
208 // abort if someone beat us to the initialization
209 if (!this_oop->is_not_initialized()) return; // note: not equivalent to is_initialized()
210
211 ClassState old_state = this_oop->init_state();
212 link_class_impl(this_oop, true, THREAD);
213 if (HAS_PENDING_EXCEPTION) {
214 CLEAR_PENDING_EXCEPTION;
215 // Abort if linking the class throws an exception.
216
217 // Use a test to avoid redundantly resetting the state if there's
218 // no change. Set_init_state() asserts that state changes make
219 // progress, whereas here we might just be spinning in place.
220 if( old_state != this_oop->_init_state )
221 this_oop->set_init_state (old_state);
222 } else {
223 // linking successfull, mark class as initialized
224 this_oop->set_init_state (fully_initialized);
225 // trace
226 if (TraceClassInitialization) {
227 ResourceMark rm(THREAD);
228 tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
229 }
230 }
231 }
232
233
234 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
235 // process. The step comments refers to the procedure described in that section.
236 // Note: implementation moved to static method to expose the this pointer.
237 void instanceKlass::initialize(TRAPS) {
238 if (this->should_be_initialized()) {
239 HandleMark hm(THREAD);
240 instanceKlassHandle this_oop(THREAD, this->as_klassOop());
241 initialize_impl(this_oop, CHECK);
242 // Note: at this point the class may be initialized
243 // OR it may be in the state of being initialized
244 // in case of recursive initialization!
245 } else {
246 assert(is_initialized(), "sanity check");
247 }
248 }
249
250
251 bool instanceKlass::verify_code(
252 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
253 // 1) Verify the bytecodes
254 Verifier::Mode mode =
255 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
256 return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
257 }
258
259
260 // Used exclusively by the shared spaces dump mechanism to prevent
261 // classes mapped into the shared regions in new VMs from appearing linked.
262
263 void instanceKlass::unlink_class() {
264 assert(is_linked(), "must be linked");
265 _init_state = loaded;
266 }
267
268 void instanceKlass::link_class(TRAPS) {
269 assert(is_loaded(), "must be loaded");
270 if (!is_linked()) {
271 instanceKlassHandle this_oop(THREAD, this->as_klassOop());
272 link_class_impl(this_oop, true, CHECK);
273 }
274 }
275
276 // Called to verify that a class can link during initialization, without
277 // throwing a VerifyError.
278 bool instanceKlass::link_class_or_fail(TRAPS) {
279 assert(is_loaded(), "must be loaded");
280 if (!is_linked()) {
281 instanceKlassHandle this_oop(THREAD, this->as_klassOop());
282 link_class_impl(this_oop, false, CHECK_false);
283 }
284 return is_linked();
285 }
286
287 bool instanceKlass::link_class_impl(
288 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
289 // check for error state
290 if (this_oop->is_in_error_state()) {
291 ResourceMark rm(THREAD);
292 THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
293 this_oop->external_name(), false);
294 }
295 // return if already verified
296 if (this_oop->is_linked()) {
297 return true;
298 }
299
300 // Timing
301 // timer handles recursion
302 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
303 JavaThread* jt = (JavaThread*)THREAD;
304
305 // link super class before linking this class
306 instanceKlassHandle super(THREAD, this_oop->super());
307 if (super.not_null()) {
308 if (super->is_interface()) { // check if super class is an interface
309 ResourceMark rm(THREAD);
310 Exceptions::fthrow(
311 THREAD_AND_LOCATION,
312 vmSymbols::java_lang_IncompatibleClassChangeError(),
313 "class %s has interface %s as super class",
314 this_oop->external_name(),
315 super->external_name()
316 );
317 return false;
318 }
319
320 link_class_impl(super, throw_verifyerror, CHECK_false);
321 }
322
323 // link all interfaces implemented by this class before linking this class
324 objArrayHandle interfaces (THREAD, this_oop->local_interfaces());
325 int num_interfaces = interfaces->length();
326 for (int index = 0; index < num_interfaces; index++) {
327 HandleMark hm(THREAD);
328 instanceKlassHandle ih(THREAD, klassOop(interfaces->obj_at(index)));
329 link_class_impl(ih, throw_verifyerror, CHECK_false);
330 }
331
332 // in case the class is linked in the process of linking its superclasses
333 if (this_oop->is_linked()) {
334 return true;
335 }
336
337 // trace only the link time for this klass that includes
338 // the verification time
339 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
340 ClassLoader::perf_class_link_selftime(),
341 ClassLoader::perf_classes_linked(),
342 jt->get_thread_stat()->perf_recursion_counts_addr(),
343 jt->get_thread_stat()->perf_timers_addr(),
344 PerfClassTraceTime::CLASS_LINK);
345
346 // verification & rewriting
347 {
348 ObjectLocker ol(this_oop, THREAD);
349 // rewritten will have been set if loader constraint error found
350 // on an earlier link attempt
351 // don't verify or rewrite if already rewritten
352 if (!this_oop->is_linked()) {
353 if (!this_oop->is_rewritten()) {
354 {
355 // Timer includes any side effects of class verification (resolution,
356 // etc), but not recursive entry into verify_code().
357 PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
358 ClassLoader::perf_class_verify_selftime(),
359 ClassLoader::perf_classes_verified(),
360 jt->get_thread_stat()->perf_recursion_counts_addr(),
361 jt->get_thread_stat()->perf_timers_addr(),
362 PerfClassTraceTime::CLASS_VERIFY);
363 bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
364 if (!verify_ok) {
365 return false;
366 }
367 }
368
369 // Just in case a side-effect of verify linked this class already
370 // (which can sometimes happen since the verifier loads classes
371 // using custom class loaders, which are free to initialize things)
372 if (this_oop->is_linked()) {
373 return true;
374 }
375
376 // also sets rewritten
377 this_oop->rewrite_class(CHECK_false);
378 }
379
380 // relocate jsrs and link methods after they are all rewritten
381 this_oop->relocate_and_link_methods(CHECK_false);
382
383 // Initialize the vtable and interface table after
384 // methods have been rewritten since rewrite may
385 // fabricate new methodOops.
386 // also does loader constraint checking
387 if (!this_oop()->is_shared()) {
388 ResourceMark rm(THREAD);
389 this_oop->vtable()->initialize_vtable(true, CHECK_false);
390 this_oop->itable()->initialize_itable(true, CHECK_false);
391 }
392 #ifdef ASSERT
393 else {
394 ResourceMark rm(THREAD);
395 this_oop->vtable()->verify(tty, true);
396 // In case itable verification is ever added.
397 // this_oop->itable()->verify(tty, true);
398 }
399 #endif
400 this_oop->set_init_state(linked);
401 if (JvmtiExport::should_post_class_prepare()) {
402 Thread *thread = THREAD;
403 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
404 JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
405 }
406 }
407 }
408 return true;
409 }
410
411
412 // Rewrite the byte codes of all of the methods of a class.
413 // The rewriter must be called exactly once. Rewriting must happen after
414 // verification but before the first method of the class is executed.
415 void instanceKlass::rewrite_class(TRAPS) {
416 assert(is_loaded(), "must be loaded");
417 instanceKlassHandle this_oop(THREAD, this->as_klassOop());
418 if (this_oop->is_rewritten()) {
419 assert(this_oop()->is_shared(), "rewriting an unshared class?");
420 return;
421 }
422 Rewriter::rewrite(this_oop, CHECK);
423 this_oop->set_rewritten();
424 }
425
426 // Now relocate and link method entry points after class is rewritten.
427 // This is outside is_rewritten flag. In case of an exception, it can be
428 // executed more than once.
429 void instanceKlass::relocate_and_link_methods(TRAPS) {
430 assert(is_loaded(), "must be loaded");
431 instanceKlassHandle this_oop(THREAD, this->as_klassOop());
432 Rewriter::relocate_and_link(this_oop, CHECK);
433 }
434
435
436 void instanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
437 // Make sure klass is linked (verified) before initialization
438 // A class could already be verified, since it has been reflected upon.
439 this_oop->link_class(CHECK);
440
441 DTRACE_CLASSINIT_PROBE(required, instanceKlass::cast(this_oop()), -1);
442
443 bool wait = false;
444
445 // refer to the JVM book page 47 for description of steps
446 // Step 1
447 { ObjectLocker ol(this_oop, THREAD);
448
449 Thread *self = THREAD; // it's passed the current thread
450
451 // Step 2
452 // If we were to use wait() instead of waitInterruptibly() then
453 // we might end up throwing IE from link/symbol resolution sites
454 // that aren't expected to throw. This would wreak havoc. See 6320309.
455 while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
456 wait = true;
457 ol.waitUninterruptibly(CHECK);
458 }
459
460 // Step 3
461 if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
462 DTRACE_CLASSINIT_PROBE_WAIT(recursive, instanceKlass::cast(this_oop()), -1,wait);
463 return;
464 }
465
466 // Step 4
467 if (this_oop->is_initialized()) {
468 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, instanceKlass::cast(this_oop()), -1,wait);
469 return;
470 }
471
472 // Step 5
473 if (this_oop->is_in_error_state()) {
474 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, instanceKlass::cast(this_oop()), -1,wait);
475 ResourceMark rm(THREAD);
476 const char* desc = "Could not initialize class ";
477 const char* className = this_oop->external_name();
478 size_t msglen = strlen(desc) + strlen(className) + 1;
479 char* message = NEW_RESOURCE_ARRAY(char, msglen);
480 if (NULL == message) {
481 // Out of memory: can't create detailed error message
482 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
483 } else {
484 jio_snprintf(message, msglen, "%s%s", desc, className);
485 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
486 }
487 }
488
489 // Step 6
490 this_oop->set_init_state(being_initialized);
491 this_oop->set_init_thread(self);
492 }
493
494 // Step 7
495 klassOop super_klass = this_oop->super();
496 if (super_klass != NULL && !this_oop->is_interface() && Klass::cast(super_klass)->should_be_initialized()) {
497 Klass::cast(super_klass)->initialize(THREAD);
498
499 if (HAS_PENDING_EXCEPTION) {
500 Handle e(THREAD, PENDING_EXCEPTION);
501 CLEAR_PENDING_EXCEPTION;
502 {
503 EXCEPTION_MARK;
504 this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
505 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, superclass initialization error is thrown below
506 }
507 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, instanceKlass::cast(this_oop()), -1,wait);
508 THROW_OOP(e());
509 }
510 }
511
512 // Step 8
513 {
514 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
515 JavaThread* jt = (JavaThread*)THREAD;
516 DTRACE_CLASSINIT_PROBE_WAIT(clinit, instanceKlass::cast(this_oop()), -1,wait);
517 // Timer includes any side effects of class initialization (resolution,
518 // etc), but not recursive entry into call_class_initializer().
519 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
520 ClassLoader::perf_class_init_selftime(),
521 ClassLoader::perf_classes_inited(),
522 jt->get_thread_stat()->perf_recursion_counts_addr(),
523 jt->get_thread_stat()->perf_timers_addr(),
524 PerfClassTraceTime::CLASS_CLINIT);
525 this_oop->call_class_initializer(THREAD);
526 }
527
528 // Step 9
529 if (!HAS_PENDING_EXCEPTION) {
530 this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
531 { ResourceMark rm(THREAD);
532 debug_only(this_oop->vtable()->verify(tty, true);)
533 }
534 }
535 else {
536 // Step 10 and 11
537 Handle e(THREAD, PENDING_EXCEPTION);
538 CLEAR_PENDING_EXCEPTION;
539 {
540 EXCEPTION_MARK;
541 this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
542 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
543 }
544 DTRACE_CLASSINIT_PROBE_WAIT(error, instanceKlass::cast(this_oop()), -1,wait);
545 if (e->is_a(SystemDictionary::Error_klass())) {
546 THROW_OOP(e());
547 } else {
548 JavaCallArguments args(e);
549 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
550 vmSymbols::throwable_void_signature(),
551 &args);
552 }
553 }
554 DTRACE_CLASSINIT_PROBE_WAIT(end, instanceKlass::cast(this_oop()), -1,wait);
555 }
556
557
558 // Note: implementation moved to static method to expose the this pointer.
559 void instanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
560 instanceKlassHandle kh(THREAD, this->as_klassOop());
561 set_initialization_state_and_notify_impl(kh, state, CHECK);
562 }
563
564 void instanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
565 ObjectLocker ol(this_oop, THREAD);
566 this_oop->set_init_state(state);
567 ol.notify_all(CHECK);
568 }
569
570 // The embedded _implementor field can only record one implementor.
571 // When there are more than one implementors, the _implementor field
572 // is set to the interface klassOop itself. Following are the possible
573 // values for the _implementor field:
574 // NULL - no implementor
575 // implementor klassOop - one implementor
576 // self - more than one implementor
577 //
578 // The _implementor field only exists for interfaces.
579 void instanceKlass::add_implementor(klassOop k) {
580 assert(Compile_lock->owned_by_self(), "");
581 assert(is_interface(), "not interface");
582 // Filter out my subinterfaces.
583 // (Note: Interfaces are never on the subklass list.)
584 if (instanceKlass::cast(k)->is_interface()) return;
585
586 // Filter out subclasses whose supers already implement me.
587 // (Note: CHA must walk subclasses of direct implementors
588 // in order to locate indirect implementors.)
589 klassOop sk = instanceKlass::cast(k)->super();
590 if (sk != NULL && instanceKlass::cast(sk)->implements_interface(as_klassOop()))
591 // We only need to check one immediate superclass, since the
592 // implements_interface query looks at transitive_interfaces.
593 // Any supers of the super have the same (or fewer) transitive_interfaces.
594 return;
595
596 klassOop ik = implementor();
597 if (ik == NULL) {
598 set_implementor(k);
599 } else if (ik != this->as_klassOop()) {
600 // There is already an implementor. Use itself as an indicator of
601 // more than one implementors.
602 set_implementor(this->as_klassOop());
603 }
604
605 // The implementor also implements the transitive_interfaces
606 for (int index = 0; index < local_interfaces()->length(); index++) {
607 instanceKlass::cast(klassOop(local_interfaces()->obj_at(index)))->add_implementor(k);
608 }
609 }
610
611 void instanceKlass::init_implementor() {
612 if (is_interface()) {
613 set_implementor(NULL);
614 }
615 }
616
617
618 void instanceKlass::process_interfaces(Thread *thread) {
619 // link this class into the implementors list of every interface it implements
620 KlassHandle this_as_oop (thread, this->as_klassOop());
621 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
622 assert(local_interfaces()->obj_at(i)->is_klass(), "must be a klass");
623 instanceKlass* interf = instanceKlass::cast(klassOop(local_interfaces()->obj_at(i)));
624 assert(interf->is_interface(), "expected interface");
625 interf->add_implementor(this_as_oop());
626 }
627 }
628
629 bool instanceKlass::can_be_primary_super_slow() const {
630 if (is_interface())
631 return false;
632 else
633 return Klass::can_be_primary_super_slow();
634 }
635
636 objArrayOop instanceKlass::compute_secondary_supers(int num_extra_slots, TRAPS) {
637 // The secondaries are the implemented interfaces.
638 instanceKlass* ik = instanceKlass::cast(as_klassOop());
639 objArrayHandle interfaces (THREAD, ik->transitive_interfaces());
640 int num_secondaries = num_extra_slots + interfaces->length();
641 if (num_secondaries == 0) {
642 return Universe::the_empty_system_obj_array();
643 } else if (num_extra_slots == 0) {
644 return interfaces();
645 } else {
646 // a mix of both
647 objArrayOop secondaries = oopFactory::new_system_objArray(num_secondaries, CHECK_NULL);
648 for (int i = 0; i < interfaces->length(); i++) {
649 secondaries->obj_at_put(num_extra_slots+i, interfaces->obj_at(i));
650 }
651 return secondaries;
652 }
653 }
654
655 bool instanceKlass::compute_is_subtype_of(klassOop k) {
656 if (Klass::cast(k)->is_interface()) {
657 return implements_interface(k);
658 } else {
659 return Klass::compute_is_subtype_of(k);
660 }
661 }
662
663 bool instanceKlass::implements_interface(klassOop k) const {
664 if (as_klassOop() == k) return true;
665 assert(Klass::cast(k)->is_interface(), "should be an interface class");
666 for (int i = 0; i < transitive_interfaces()->length(); i++) {
667 if (transitive_interfaces()->obj_at(i) == k) {
668 return true;
669 }
670 }
671 return false;
672 }
673
674 objArrayOop instanceKlass::allocate_objArray(int n, int length, TRAPS) {
675 if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
676 if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
677 report_java_out_of_memory("Requested array size exceeds VM limit");
678 JvmtiExport::post_array_size_exhausted();
679 THROW_OOP_0(Universe::out_of_memory_error_array_size());
680 }
681 int size = objArrayOopDesc::object_size(length);
682 klassOop ak = array_klass(n, CHECK_NULL);
683 KlassHandle h_ak (THREAD, ak);
684 objArrayOop o =
685 (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
686 return o;
687 }
688
689 instanceOop instanceKlass::register_finalizer(instanceOop i, TRAPS) {
690 if (TraceFinalizerRegistration) {
691 tty->print("Registered ");
692 i->print_value_on(tty);
693 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
694 }
695 instanceHandle h_i(THREAD, i);
696 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
697 JavaValue result(T_VOID);
698 JavaCallArguments args(h_i);
699 methodHandle mh (THREAD, Universe::finalizer_register_method());
700 JavaCalls::call(&result, mh, &args, CHECK_NULL);
701 return h_i();
702 }
703
704 instanceOop instanceKlass::allocate_instance(TRAPS) {
705 assert(!oop_is_instanceMirror(), "wrong allocation path");
706 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
707 int size = size_helper(); // Query before forming handle.
708
709 KlassHandle h_k(THREAD, as_klassOop());
710
711 instanceOop i;
712
713 i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
714 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
715 i = register_finalizer(i, CHECK_NULL);
716 }
717 return i;
718 }
719
720 instanceOop instanceKlass::allocate_permanent_instance(TRAPS) {
721 // Finalizer registration occurs in the Object.<init> constructor
722 // and constructors normally aren't run when allocating perm
723 // instances so simply disallow finalizable perm objects. This can
724 // be relaxed if a need for it is found.
725 assert(!has_finalizer(), "perm objects not allowed to have finalizers");
726 assert(!oop_is_instanceMirror(), "wrong allocation path");
727 int size = size_helper(); // Query before forming handle.
728 KlassHandle h_k(THREAD, as_klassOop());
729 instanceOop i = (instanceOop)
730 CollectedHeap::permanent_obj_allocate(h_k, size, CHECK_NULL);
731 return i;
732 }
733
734 void instanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
735 if (is_interface() || is_abstract()) {
736 ResourceMark rm(THREAD);
737 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
738 : vmSymbols::java_lang_InstantiationException(), external_name());
739 }
740 if (as_klassOop() == SystemDictionary::Class_klass()) {
741 ResourceMark rm(THREAD);
742 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
743 : vmSymbols::java_lang_IllegalAccessException(), external_name());
744 }
745 }
746
747 klassOop instanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
748 instanceKlassHandle this_oop(THREAD, as_klassOop());
749 return array_klass_impl(this_oop, or_null, n, THREAD);
750 }
751
752 klassOop instanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
753 if (this_oop->array_klasses() == NULL) {
754 if (or_null) return NULL;
755
756 ResourceMark rm;
757 JavaThread *jt = (JavaThread *)THREAD;
758 {
759 // Atomic creation of array_klasses
760 MutexLocker mc(Compile_lock, THREAD); // for vtables
761 MutexLocker ma(MultiArray_lock, THREAD);
762
763 // Check if update has already taken place
764 if (this_oop->array_klasses() == NULL) {
765 objArrayKlassKlass* oakk =
766 (objArrayKlassKlass*)Universe::objArrayKlassKlassObj()->klass_part();
767
768 klassOop k = oakk->allocate_objArray_klass(1, this_oop, CHECK_NULL);
769 this_oop->set_array_klasses(k);
770 }
771 }
772 }
773 // _this will always be set at this point
774 objArrayKlass* oak = (objArrayKlass*)this_oop->array_klasses()->klass_part();
775 if (or_null) {
776 return oak->array_klass_or_null(n);
777 }
778 return oak->array_klass(n, CHECK_NULL);
779 }
780
781 klassOop instanceKlass::array_klass_impl(bool or_null, TRAPS) {
782 return array_klass_impl(or_null, 1, THREAD);
783 }
784
785 void instanceKlass::call_class_initializer(TRAPS) {
786 instanceKlassHandle ik (THREAD, as_klassOop());
787 call_class_initializer_impl(ik, THREAD);
788 }
789
790 static int call_class_initializer_impl_counter = 0; // for debugging
791
792 methodOop instanceKlass::class_initializer() {
793 methodOop clinit = find_method(
794 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
795 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
796 return clinit;
797 }
798 return NULL;
799 }
800
801 void instanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
802 methodHandle h_method(THREAD, this_oop->class_initializer());
803 assert(!this_oop->is_initialized(), "we cannot initialize twice");
804 if (TraceClassInitialization) {
805 tty->print("%d Initializing ", call_class_initializer_impl_counter++);
806 this_oop->name()->print_value();
807 tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
808 }
809 if (h_method() != NULL) {
810 JavaCallArguments args; // No arguments
811 JavaValue result(T_VOID);
812 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
813 }
814 }
815
816
817 void instanceKlass::mask_for(methodHandle method, int bci,
818 InterpreterOopMap* entry_for) {
819 // Dirty read, then double-check under a lock.
820 if (_oop_map_cache == NULL) {
821 // Otherwise, allocate a new one.
822 MutexLocker x(OopMapCacheAlloc_lock);
823 // First time use. Allocate a cache in C heap
824 if (_oop_map_cache == NULL) {
825 _oop_map_cache = new OopMapCache();
826 }
827 }
828 // _oop_map_cache is constant after init; lookup below does is own locking.
829 _oop_map_cache->lookup(method, bci, entry_for);
830 }
831
832
833 bool instanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
834 for (JavaFieldStream fs(as_klassOop()); !fs.done(); fs.next()) {
835 Symbol* f_name = fs.name();
836 Symbol* f_sig = fs.signature();
837 if (f_name == name && f_sig == sig) {
838 fd->initialize(as_klassOop(), fs.index());
839 return true;
840 }
841 }
842 return false;
843 }
844
845
846 void instanceKlass::shared_symbols_iterate(SymbolClosure* closure) {
847 Klass::shared_symbols_iterate(closure);
848 closure->do_symbol(&_generic_signature);
849 closure->do_symbol(&_source_file_name);
850
851 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
852 int name_index = fs.name_index();
853 closure->do_symbol(constants()->symbol_at_addr(name_index));
854 int sig_index = fs.signature_index();
855 closure->do_symbol(constants()->symbol_at_addr(sig_index));
856 }
857 }
858
859
860 klassOop instanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
861 const int n = local_interfaces()->length();
862 for (int i = 0; i < n; i++) {
863 klassOop intf1 = klassOop(local_interfaces()->obj_at(i));
864 assert(Klass::cast(intf1)->is_interface(), "just checking type");
865 // search for field in current interface
866 if (instanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
867 assert(fd->is_static(), "interface field must be static");
868 return intf1;
869 }
870 // search for field in direct superinterfaces
871 klassOop intf2 = instanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
872 if (intf2 != NULL) return intf2;
873 }
874 // otherwise field lookup fails
875 return NULL;
876 }
877
878
879 klassOop instanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
880 // search order according to newest JVM spec (5.4.3.2, p.167).
881 // 1) search for field in current klass
882 if (find_local_field(name, sig, fd)) {
883 return as_klassOop();
884 }
885 // 2) search for field recursively in direct superinterfaces
886 { klassOop intf = find_interface_field(name, sig, fd);
887 if (intf != NULL) return intf;
888 }
889 // 3) apply field lookup recursively if superclass exists
890 { klassOop supr = super();
891 if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, fd);
892 }
893 // 4) otherwise field lookup fails
894 return NULL;
895 }
896
897
898 klassOop instanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
899 // search order according to newest JVM spec (5.4.3.2, p.167).
900 // 1) search for field in current klass
901 if (find_local_field(name, sig, fd)) {
902 if (fd->is_static() == is_static) return as_klassOop();
903 }
904 // 2) search for field recursively in direct superinterfaces
905 if (is_static) {
906 klassOop intf = find_interface_field(name, sig, fd);
907 if (intf != NULL) return intf;
908 }
909 // 3) apply field lookup recursively if superclass exists
910 { klassOop supr = super();
911 if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
912 }
913 // 4) otherwise field lookup fails
914 return NULL;
915 }
916
917
918 bool instanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
919 for (JavaFieldStream fs(as_klassOop()); !fs.done(); fs.next()) {
920 if (fs.offset() == offset) {
921 fd->initialize(as_klassOop(), fs.index());
922 if (fd->is_static() == is_static) return true;
923 }
924 }
925 return false;
926 }
927
928
929 bool instanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
930 klassOop klass = as_klassOop();
931 while (klass != NULL) {
932 if (instanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
933 return true;
934 }
935 klass = Klass::cast(klass)->super();
936 }
937 return false;
938 }
939
940
941 void instanceKlass::methods_do(void f(methodOop method)) {
942 int len = methods()->length();
943 for (int index = 0; index < len; index++) {
944 methodOop m = methodOop(methods()->obj_at(index));
945 assert(m->is_method(), "must be method");
946 f(m);
947 }
948 }
949
950
951 void instanceKlass::do_local_static_fields(FieldClosure* cl) {
952 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
953 if (fs.access_flags().is_static()) {
954 fieldDescriptor fd;
955 fd.initialize(as_klassOop(), fs.index());
956 cl->do_field(&fd);
957 }
958 }
959 }
960
961
962 void instanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
963 instanceKlassHandle h_this(THREAD, as_klassOop());
964 do_local_static_fields_impl(h_this, f, CHECK);
965 }
966
967
968 void instanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
969 for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
970 if (fs.access_flags().is_static()) {
971 fieldDescriptor fd;
972 fd.initialize(this_oop(), fs.index());
973 f(&fd, CHECK);
974 }
975 }
976 }
977
978
979 static int compare_fields_by_offset(int* a, int* b) {
980 return a[0] - b[0];
981 }
982
983 void instanceKlass::do_nonstatic_fields(FieldClosure* cl) {
984 instanceKlass* super = superklass();
985 if (super != NULL) {
986 super->do_nonstatic_fields(cl);
987 }
988 fieldDescriptor fd;
989 int length = java_fields_count();
990 // In DebugInfo nonstatic fields are sorted by offset.
991 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
992 int j = 0;
993 for (int i = 0; i < length; i += 1) {
994 fd.initialize(as_klassOop(), i);
995 if (!fd.is_static()) {
996 fields_sorted[j + 0] = fd.offset();
997 fields_sorted[j + 1] = i;
998 j += 2;
999 }
1000 }
1001 if (j > 0) {
1002 length = j;
1003 // _sort_Fn is defined in growableArray.hpp.
1004 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1005 for (int i = 0; i < length; i += 2) {
1006 fd.initialize(as_klassOop(), fields_sorted[i + 1]);
1007 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1008 cl->do_field(&fd);
1009 }
1010 }
1011 FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
1012 }
1013
1014
1015 void instanceKlass::array_klasses_do(void f(klassOop k)) {
1016 if (array_klasses() != NULL)
1017 arrayKlass::cast(array_klasses())->array_klasses_do(f);
1018 }
1019
1020
1021 void instanceKlass::with_array_klasses_do(void f(klassOop k)) {
1022 f(as_klassOop());
1023 array_klasses_do(f);
1024 }
1025
1026 #ifdef ASSERT
1027 static int linear_search(objArrayOop methods, Symbol* name, Symbol* signature) {
1028 int len = methods->length();
1029 for (int index = 0; index < len; index++) {
1030 methodOop m = (methodOop)(methods->obj_at(index));
1031 assert(m->is_method(), "must be method");
1032 if (m->signature() == signature && m->name() == name) {
1033 return index;
1034 }
1035 }
1036 return -1;
1037 }
1038 #endif
1039
1040 methodOop instanceKlass::find_method(Symbol* name, Symbol* signature) const {
1041 return instanceKlass::find_method(methods(), name, signature);
1042 }
1043
1044 methodOop instanceKlass::find_method(objArrayOop methods, Symbol* name, Symbol* signature) {
1045 int len = methods->length();
1046 // methods are sorted, so do binary search
1047 int l = 0;
1048 int h = len - 1;
1049 while (l <= h) {
1050 int mid = (l + h) >> 1;
1051 methodOop m = (methodOop)methods->obj_at(mid);
1052 assert(m->is_method(), "must be method");
1053 int res = m->name()->fast_compare(name);
1054 if (res == 0) {
1055 // found matching name; do linear search to find matching signature
1056 // first, quick check for common case
1057 if (m->signature() == signature) return m;
1058 // search downwards through overloaded methods
1059 int i;
1060 for (i = mid - 1; i >= l; i--) {
1061 methodOop m = (methodOop)methods->obj_at(i);
1062 assert(m->is_method(), "must be method");
1063 if (m->name() != name) break;
1064 if (m->signature() == signature) return m;
1065 }
1066 // search upwards
1067 for (i = mid + 1; i <= h; i++) {
1068 methodOop m = (methodOop)methods->obj_at(i);
1069 assert(m->is_method(), "must be method");
1070 if (m->name() != name) break;
1071 if (m->signature() == signature) return m;
1072 }
1073 // not found
1074 #ifdef ASSERT
1075 int index = linear_search(methods, name, signature);
1076 assert(index == -1, err_msg("binary search should have found entry %d", index));
1077 #endif
1078 return NULL;
1079 } else if (res < 0) {
1080 l = mid + 1;
1081 } else {
1082 h = mid - 1;
1083 }
1084 }
1085 #ifdef ASSERT
1086 int index = linear_search(methods, name, signature);
1087 assert(index == -1, err_msg("binary search should have found entry %d", index));
1088 #endif
1089 return NULL;
1090 }
1091
1092 methodOop instanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
1093 klassOop klass = as_klassOop();
1094 while (klass != NULL) {
1095 methodOop method = instanceKlass::cast(klass)->find_method(name, signature);
1096 if (method != NULL) return method;
1097 klass = instanceKlass::cast(klass)->super();
1098 }
1099 return NULL;
1100 }
1101
1102 // lookup a method in all the interfaces that this class implements
1103 methodOop instanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1104 Symbol* signature) const {
1105 objArrayOop all_ifs = instanceKlass::cast(as_klassOop())->transitive_interfaces();
1106 int num_ifs = all_ifs->length();
1107 instanceKlass *ik = NULL;
1108 for (int i = 0; i < num_ifs; i++) {
1109 ik = instanceKlass::cast(klassOop(all_ifs->obj_at(i)));
1110 methodOop m = ik->lookup_method(name, signature);
1111 if (m != NULL) {
1112 return m;
1113 }
1114 }
1115 return NULL;
1116 }
1117
1118 /* jni_id_for_impl for jfieldIds only */
1119 JNIid* instanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
1120 MutexLocker ml(JfieldIdCreation_lock);
1121 // Retry lookup after we got the lock
1122 JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
1123 if (probe == NULL) {
1124 // Slow case, allocate new static field identifier
1125 probe = new JNIid(this_oop->as_klassOop(), offset, this_oop->jni_ids());
1126 this_oop->set_jni_ids(probe);
1127 }
1128 return probe;
1129 }
1130
1131
1132 /* jni_id_for for jfieldIds only */
1133 JNIid* instanceKlass::jni_id_for(int offset) {
1134 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1135 if (probe == NULL) {
1136 probe = jni_id_for_impl(this->as_klassOop(), offset);
1137 }
1138 return probe;
1139 }
1140
1141 u2 instanceKlass::enclosing_method_data(int offset) {
1142 typeArrayOop inner_class_list = inner_classes();
1143 if (inner_class_list == NULL) {
1144 return 0;
1145 }
1146 int length = inner_class_list->length();
1147 if (length % inner_class_next_offset == 0) {
1148 return 0;
1149 } else {
1150 int index = length - enclosing_method_attribute_size;
1151 typeArrayHandle inner_class_list_h(inner_class_list);
1152 assert(offset < enclosing_method_attribute_size, "invalid offset");
1153 return inner_class_list_h->ushort_at(index + offset);
1154 }
1155 }
1156
1157 void instanceKlass::set_enclosing_method_indices(u2 class_index,
1158 u2 method_index) {
1159 typeArrayOop inner_class_list = inner_classes();
1160 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1161 int length = inner_class_list->length();
1162 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1163 int index = length - enclosing_method_attribute_size;
1164 typeArrayHandle inner_class_list_h(inner_class_list);
1165 inner_class_list_h->ushort_at_put(
1166 index + enclosing_method_class_index_offset, class_index);
1167 inner_class_list_h->ushort_at_put(
1168 index + enclosing_method_method_index_offset, method_index);
1169 }
1170 }
1171
1172 // Lookup or create a jmethodID.
1173 // This code is called by the VMThread and JavaThreads so the
1174 // locking has to be done very carefully to avoid deadlocks
1175 // and/or other cache consistency problems.
1176 //
1177 jmethodID instanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1178 size_t idnum = (size_t)method_h->method_idnum();
1179 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1180 size_t length = 0;
1181 jmethodID id = NULL;
1182
1183 // We use a double-check locking idiom here because this cache is
1184 // performance sensitive. In the normal system, this cache only
1185 // transitions from NULL to non-NULL which is safe because we use
1186 // release_set_methods_jmethod_ids() to advertise the new cache.
1187 // A partially constructed cache should never be seen by a racing
1188 // thread. We also use release_store_ptr() to save a new jmethodID
1189 // in the cache so a partially constructed jmethodID should never be
1190 // seen either. Cache reads of existing jmethodIDs proceed without a
1191 // lock, but cache writes of a new jmethodID requires uniqueness and
1192 // creation of the cache itself requires no leaks so a lock is
1193 // generally acquired in those two cases.
1194 //
1195 // If the RedefineClasses() API has been used, then this cache can
1196 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1197 // Cache creation requires no leaks and we require safety between all
1198 // cache accesses and freeing of the old cache so a lock is generally
1199 // acquired when the RedefineClasses() API has been used.
1200
1201 if (jmeths != NULL) {
1202 // the cache already exists
1203 if (!ik_h->idnum_can_increment()) {
1204 // the cache can't grow so we can just get the current values
1205 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1206 } else {
1207 // cache can grow so we have to be more careful
1208 if (Threads::number_of_threads() == 0 ||
1209 SafepointSynchronize::is_at_safepoint()) {
1210 // we're single threaded or at a safepoint - no locking needed
1211 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1212 } else {
1213 MutexLocker ml(JmethodIdCreation_lock);
1214 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1215 }
1216 }
1217 }
1218 // implied else:
1219 // we need to allocate a cache so default length and id values are good
1220
1221 if (jmeths == NULL || // no cache yet
1222 length <= idnum || // cache is too short
1223 id == NULL) { // cache doesn't contain entry
1224
1225 // This function can be called by the VMThread so we have to do all
1226 // things that might block on a safepoint before grabbing the lock.
1227 // Otherwise, we can deadlock with the VMThread or have a cache
1228 // consistency issue. These vars keep track of what we might have
1229 // to free after the lock is dropped.
1230 jmethodID to_dealloc_id = NULL;
1231 jmethodID* to_dealloc_jmeths = NULL;
1232
1233 // may not allocate new_jmeths or use it if we allocate it
1234 jmethodID* new_jmeths = NULL;
1235 if (length <= idnum) {
1236 // allocate a new cache that might be used
1237 size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1238 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1239 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1240 // cache size is stored in element[0], other elements offset by one
1241 new_jmeths[0] = (jmethodID)size;
1242 }
1243
1244 // allocate a new jmethodID that might be used
1245 jmethodID new_id = NULL;
1246 if (method_h->is_old() && !method_h->is_obsolete()) {
1247 // The method passed in is old (but not obsolete), we need to use the current version
1248 methodOop current_method = ik_h->method_with_idnum((int)idnum);
1249 assert(current_method != NULL, "old and but not obsolete, so should exist");
1250 methodHandle current_method_h(current_method == NULL? method_h() : current_method);
1251 new_id = JNIHandles::make_jmethod_id(current_method_h);
1252 } else {
1253 // It is the current version of the method or an obsolete method,
1254 // use the version passed in
1255 new_id = JNIHandles::make_jmethod_id(method_h);
1256 }
1257
1258 if (Threads::number_of_threads() == 0 ||
1259 SafepointSynchronize::is_at_safepoint()) {
1260 // we're single threaded or at a safepoint - no locking needed
1261 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1262 &to_dealloc_id, &to_dealloc_jmeths);
1263 } else {
1264 MutexLocker ml(JmethodIdCreation_lock);
1265 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1266 &to_dealloc_id, &to_dealloc_jmeths);
1267 }
1268
1269 // The lock has been dropped so we can free resources.
1270 // Free up either the old cache or the new cache if we allocated one.
1271 if (to_dealloc_jmeths != NULL) {
1272 FreeHeap(to_dealloc_jmeths);
1273 }
1274 // free up the new ID since it wasn't needed
1275 if (to_dealloc_id != NULL) {
1276 JNIHandles::destroy_jmethod_id(to_dealloc_id);
1277 }
1278 }
1279 return id;
1280 }
1281
1282
1283 // Common code to fetch the jmethodID from the cache or update the
1284 // cache with the new jmethodID. This function should never do anything
1285 // that causes the caller to go to a safepoint or we can deadlock with
1286 // the VMThread or have cache consistency issues.
1287 //
1288 jmethodID instanceKlass::get_jmethod_id_fetch_or_update(
1289 instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1290 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1291 jmethodID** to_dealloc_jmeths_p) {
1292 assert(new_id != NULL, "sanity check");
1293 assert(to_dealloc_id_p != NULL, "sanity check");
1294 assert(to_dealloc_jmeths_p != NULL, "sanity check");
1295 assert(Threads::number_of_threads() == 0 ||
1296 SafepointSynchronize::is_at_safepoint() ||
1297 JmethodIdCreation_lock->owned_by_self(), "sanity check");
1298
1299 // reacquire the cache - we are locked, single threaded or at a safepoint
1300 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1301 jmethodID id = NULL;
1302 size_t length = 0;
1303
1304 if (jmeths == NULL || // no cache yet
1305 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
1306 if (jmeths != NULL) {
1307 // copy any existing entries from the old cache
1308 for (size_t index = 0; index < length; index++) {
1309 new_jmeths[index+1] = jmeths[index+1];
1310 }
1311 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
1312 }
1313 ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1314 } else {
1315 // fetch jmethodID (if any) from the existing cache
1316 id = jmeths[idnum+1];
1317 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
1318 }
1319 if (id == NULL) {
1320 // No matching jmethodID in the existing cache or we have a new
1321 // cache or we just grew the cache. This cache write is done here
1322 // by the first thread to win the foot race because a jmethodID
1323 // needs to be unique once it is generally available.
1324 id = new_id;
1325
1326 // The jmethodID cache can be read while unlocked so we have to
1327 // make sure the new jmethodID is complete before installing it
1328 // in the cache.
1329 OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1330 } else {
1331 *to_dealloc_id_p = new_id; // save new id for later delete
1332 }
1333 return id;
1334 }
1335
1336
1337 // Common code to get the jmethodID cache length and the jmethodID
1338 // value at index idnum if there is one.
1339 //
1340 void instanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1341 size_t idnum, size_t *length_p, jmethodID* id_p) {
1342 assert(cache != NULL, "sanity check");
1343 assert(length_p != NULL, "sanity check");
1344 assert(id_p != NULL, "sanity check");
1345
1346 // cache size is stored in element[0], other elements offset by one
1347 *length_p = (size_t)cache[0];
1348 if (*length_p <= idnum) { // cache is too short
1349 *id_p = NULL;
1350 } else {
1351 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
1352 }
1353 }
1354
1355
1356 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
1357 jmethodID instanceKlass::jmethod_id_or_null(methodOop method) {
1358 size_t idnum = (size_t)method->method_idnum();
1359 jmethodID* jmeths = methods_jmethod_ids_acquire();
1360 size_t length; // length assigned as debugging crumb
1361 jmethodID id = NULL;
1362 if (jmeths != NULL && // If there is a cache
1363 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
1364 id = jmeths[idnum+1]; // Look up the id (may be NULL)
1365 }
1366 return id;
1367 }
1368
1369
1370 // Cache an itable index
1371 void instanceKlass::set_cached_itable_index(size_t idnum, int index) {
1372 int* indices = methods_cached_itable_indices_acquire();
1373 int* to_dealloc_indices = NULL;
1374
1375 // We use a double-check locking idiom here because this cache is
1376 // performance sensitive. In the normal system, this cache only
1377 // transitions from NULL to non-NULL which is safe because we use
1378 // release_set_methods_cached_itable_indices() to advertise the
1379 // new cache. A partially constructed cache should never be seen
1380 // by a racing thread. Cache reads and writes proceed without a
1381 // lock, but creation of the cache itself requires no leaks so a
1382 // lock is generally acquired in that case.
1383 //
1384 // If the RedefineClasses() API has been used, then this cache can
1385 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1386 // Cache creation requires no leaks and we require safety between all
1387 // cache accesses and freeing of the old cache so a lock is generally
1388 // acquired when the RedefineClasses() API has been used.
1389
1390 if (indices == NULL || idnum_can_increment()) {
1391 // we need a cache or the cache can grow
1392 MutexLocker ml(JNICachedItableIndex_lock);
1393 // reacquire the cache to see if another thread already did the work
1394 indices = methods_cached_itable_indices_acquire();
1395 size_t length = 0;
1396 // cache size is stored in element[0], other elements offset by one
1397 if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
1398 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1399 int* new_indices = NEW_C_HEAP_ARRAY(int, size+1, mtClass);
1400 new_indices[0] = (int)size;
1401 // copy any existing entries
1402 size_t i;
1403 for (i = 0; i < length; i++) {
1404 new_indices[i+1] = indices[i+1];
1405 }
1406 // Set all the rest to -1
1407 for (i = length; i < size; i++) {
1408 new_indices[i+1] = -1;
1409 }
1410 if (indices != NULL) {
1411 // We have an old cache to delete so save it for after we
1412 // drop the lock.
1413 to_dealloc_indices = indices;
1414 }
1415 release_set_methods_cached_itable_indices(indices = new_indices);
1416 }
1417
1418 if (idnum_can_increment()) {
1419 // this cache can grow so we have to write to it safely
1420 indices[idnum+1] = index;
1421 }
1422 } else {
1423 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
1424 }
1425
1426 if (!idnum_can_increment()) {
1427 // The cache cannot grow and this JNI itable index value does not
1428 // have to be unique like a jmethodID. If there is a race to set it,
1429 // it doesn't matter.
1430 indices[idnum+1] = index;
1431 }
1432
1433 if (to_dealloc_indices != NULL) {
1434 // we allocated a new cache so free the old one
1435 FreeHeap(to_dealloc_indices);
1436 }
1437 }
1438
1439
1440 // Retrieve a cached itable index
1441 int instanceKlass::cached_itable_index(size_t idnum) {
1442 int* indices = methods_cached_itable_indices_acquire();
1443 if (indices != NULL && ((size_t)indices[0]) > idnum) {
1444 // indices exist and are long enough, retrieve possible cached
1445 return indices[idnum+1];
1446 }
1447 return -1;
1448 }
1449
1450
1451 //
1452 // Walk the list of dependent nmethods searching for nmethods which
1453 // are dependent on the changes that were passed in and mark them for
1454 // deoptimization. Returns the number of nmethods found.
1455 //
1456 int instanceKlass::mark_dependent_nmethods(DepChange& changes) {
1457 assert_locked_or_safepoint(CodeCache_lock);
1458 int found = 0;
1459 nmethodBucket* b = _dependencies;
1460 while (b != NULL) {
1461 nmethod* nm = b->get_nmethod();
1462 // since dependencies aren't removed until an nmethod becomes a zombie,
1463 // the dependency list may contain nmethods which aren't alive.
1464 if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1465 if (TraceDependencies) {
1466 ResourceMark rm;
1467 tty->print_cr("Marked for deoptimization");
1468 tty->print_cr(" context = %s", this->external_name());
1469 changes.print();
1470 nm->print();
1471 nm->print_dependencies();
1472 }
1473 nm->mark_for_deoptimization();
1474 found++;
1475 }
1476 b = b->next();
1477 }
1478 return found;
1479 }
1480
1481
1482 //
1483 // Add an nmethodBucket to the list of dependencies for this nmethod.
1484 // It's possible that an nmethod has multiple dependencies on this klass
1485 // so a count is kept for each bucket to guarantee that creation and
1486 // deletion of dependencies is consistent.
1487 //
1488 void instanceKlass::add_dependent_nmethod(nmethod* nm) {
1489 assert_locked_or_safepoint(CodeCache_lock);
1490 nmethodBucket* b = _dependencies;
1491 nmethodBucket* last = NULL;
1492 while (b != NULL) {
1493 if (nm == b->get_nmethod()) {
1494 b->increment();
1495 return;
1496 }
1497 b = b->next();
1498 }
1499 _dependencies = new nmethodBucket(nm, _dependencies);
1500 }
1501
1502
1503 //
1504 // Decrement count of the nmethod in the dependency list and remove
1505 // the bucket competely when the count goes to 0. This method must
1506 // find a corresponding bucket otherwise there's a bug in the
1507 // recording of dependecies.
1508 //
1509 void instanceKlass::remove_dependent_nmethod(nmethod* nm) {
1510 assert_locked_or_safepoint(CodeCache_lock);
1511 nmethodBucket* b = _dependencies;
1512 nmethodBucket* last = NULL;
1513 while (b != NULL) {
1514 if (nm == b->get_nmethod()) {
1515 if (b->decrement() == 0) {
1516 if (last == NULL) {
1517 _dependencies = b->next();
1518 } else {
1519 last->set_next(b->next());
1520 }
1521 delete b;
1522 }
1523 return;
1524 }
1525 last = b;
1526 b = b->next();
1527 }
1528 #ifdef ASSERT
1529 tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1530 nm->print();
1531 #endif // ASSERT
1532 ShouldNotReachHere();
1533 }
1534
1535
1536 #ifndef PRODUCT
1537 void instanceKlass::print_dependent_nmethods(bool verbose) {
1538 nmethodBucket* b = _dependencies;
1539 int idx = 0;
1540 while (b != NULL) {
1541 nmethod* nm = b->get_nmethod();
1542 tty->print("[%d] count=%d { ", idx++, b->count());
1543 if (!verbose) {
1544 nm->print_on(tty, "nmethod");
1545 tty->print_cr(" } ");
1546 } else {
1547 nm->print();
1548 nm->print_dependencies();
1549 tty->print_cr("--- } ");
1550 }
1551 b = b->next();
1552 }
1553 }
1554
1555
1556 bool instanceKlass::is_dependent_nmethod(nmethod* nm) {
1557 nmethodBucket* b = _dependencies;
1558 while (b != NULL) {
1559 if (nm == b->get_nmethod()) {
1560 return true;
1561 }
1562 b = b->next();
1563 }
1564 return false;
1565 }
1566 #endif //PRODUCT
1567
1568
1569 #ifdef ASSERT
1570 template <class T> void assert_is_in(T *p) {
1571 T heap_oop = oopDesc::load_heap_oop(p);
1572 if (!oopDesc::is_null(heap_oop)) {
1573 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1574 assert(Universe::heap()->is_in(o), "should be in heap");
1575 }
1576 }
1577 template <class T> void assert_is_in_closed_subset(T *p) {
1578 T heap_oop = oopDesc::load_heap_oop(p);
1579 if (!oopDesc::is_null(heap_oop)) {
1580 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1581 assert(Universe::heap()->is_in_closed_subset(o), "should be in closed");
1582 }
1583 }
1584 template <class T> void assert_is_in_reserved(T *p) {
1585 T heap_oop = oopDesc::load_heap_oop(p);
1586 if (!oopDesc::is_null(heap_oop)) {
1587 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1588 assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
1589 }
1590 }
1591 template <class T> void assert_nothing(T *p) {}
1592
1593 #else
1594 template <class T> void assert_is_in(T *p) {}
1595 template <class T> void assert_is_in_closed_subset(T *p) {}
1596 template <class T> void assert_is_in_reserved(T *p) {}
1597 template <class T> void assert_nothing(T *p) {}
1598 #endif // ASSERT
1599
1600 //
1601 // Macros that iterate over areas of oops which are specialized on type of
1602 // oop pointer either narrow or wide, depending on UseCompressedOops
1603 //
1604 // Parameters are:
1605 // T - type of oop to point to (either oop or narrowOop)
1606 // start_p - starting pointer for region to iterate over
1607 // count - number of oops or narrowOops to iterate over
1608 // do_oop - action to perform on each oop (it's arbitrary C code which
1609 // makes it more efficient to put in a macro rather than making
1610 // it a template function)
1611 // assert_fn - assert function which is template function because performance
1612 // doesn't matter when enabled.
1613 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
1614 T, start_p, count, do_oop, \
1615 assert_fn) \
1616 { \
1617 T* p = (T*)(start_p); \
1618 T* const end = p + (count); \
1619 while (p < end) { \
1620 (assert_fn)(p); \
1621 do_oop; \
1622 ++p; \
1623 } \
1624 }
1625
1626 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
1627 T, start_p, count, do_oop, \
1628 assert_fn) \
1629 { \
1630 T* const start = (T*)(start_p); \
1631 T* p = start + (count); \
1632 while (start < p) { \
1633 --p; \
1634 (assert_fn)(p); \
1635 do_oop; \
1636 } \
1637 }
1638
1639 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
1640 T, start_p, count, low, high, \
1641 do_oop, assert_fn) \
1642 { \
1643 T* const l = (T*)(low); \
1644 T* const h = (T*)(high); \
1645 assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
1646 mask_bits((intptr_t)h, sizeof(T)-1) == 0, \
1647 "bounded region must be properly aligned"); \
1648 T* p = (T*)(start_p); \
1649 T* end = p + (count); \
1650 if (p < l) p = l; \
1651 if (end > h) end = h; \
1652 while (p < end) { \
1653 (assert_fn)(p); \
1654 do_oop; \
1655 ++p; \
1656 } \
1657 }
1658
1659
1660 // The following macros call specialized macros, passing either oop or
1661 // narrowOop as the specialization type. These test the UseCompressedOops
1662 // flag.
1663 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \
1664 { \
1665 /* Compute oopmap block range. The common case \
1666 is nonstatic_oop_map_size == 1. */ \
1667 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1668 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1669 if (UseCompressedOops) { \
1670 while (map < end_map) { \
1671 InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
1672 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1673 do_oop, assert_fn) \
1674 ++map; \
1675 } \
1676 } else { \
1677 while (map < end_map) { \
1678 InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
1679 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1680 do_oop, assert_fn) \
1681 ++map; \
1682 } \
1683 } \
1684 }
1685
1686 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \
1687 { \
1688 OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \
1689 OopMapBlock* map = start_map + nonstatic_oop_map_count(); \
1690 if (UseCompressedOops) { \
1691 while (start_map < map) { \
1692 --map; \
1693 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \
1694 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1695 do_oop, assert_fn) \
1696 } \
1697 } else { \
1698 while (start_map < map) { \
1699 --map; \
1700 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \
1701 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1702 do_oop, assert_fn) \
1703 } \
1704 } \
1705 }
1706
1707 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \
1708 assert_fn) \
1709 { \
1710 /* Compute oopmap block range. The common case is \
1711 nonstatic_oop_map_size == 1, so we accept the \
1712 usually non-existent extra overhead of examining \
1713 all the maps. */ \
1714 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1715 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1716 if (UseCompressedOops) { \
1717 while (map < end_map) { \
1718 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
1719 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1720 low, high, \
1721 do_oop, assert_fn) \
1722 ++map; \
1723 } \
1724 } else { \
1725 while (map < end_map) { \
1726 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
1727 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1728 low, high, \
1729 do_oop, assert_fn) \
1730 ++map; \
1731 } \
1732 } \
1733 }
1734
1735 void instanceKlass::oop_follow_contents(oop obj) {
1736 assert(obj != NULL, "can't follow the content of NULL object");
1737 obj->follow_header();
1738 InstanceKlass_OOP_MAP_ITERATE( \
1739 obj, \
1740 MarkSweep::mark_and_push(p), \
1741 assert_is_in_closed_subset)
1742 }
1743
1744 #ifndef SERIALGC
1745 void instanceKlass::oop_follow_contents(ParCompactionManager* cm,
1746 oop obj) {
1747 assert(obj != NULL, "can't follow the content of NULL object");
1748 obj->follow_header(cm);
1749 InstanceKlass_OOP_MAP_ITERATE( \
1750 obj, \
1751 PSParallelCompact::mark_and_push(cm, p), \
1752 assert_is_in)
1753 }
1754 #endif // SERIALGC
1755
1756 // closure's do_header() method dicates whether the given closure should be
1757 // applied to the klass ptr in the object header.
1758
1759 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
1760 \
1761 int instanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
1762 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
1763 /* header */ \
1764 if (closure->do_header()) { \
1765 obj->oop_iterate_header(closure); \
1766 } \
1767 InstanceKlass_OOP_MAP_ITERATE( \
1768 obj, \
1769 SpecializationStats:: \
1770 record_do_oop_call##nv_suffix(SpecializationStats::ik); \
1771 (closure)->do_oop##nv_suffix(p), \
1772 assert_is_in_closed_subset) \
1773 return size_helper(); \
1774 }
1775
1776 #ifndef SERIALGC
1777 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
1778 \
1779 int instanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \
1780 OopClosureType* closure) { \
1781 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
1782 /* header */ \
1783 if (closure->do_header()) { \
1784 obj->oop_iterate_header(closure); \
1785 } \
1786 /* instance variables */ \
1787 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
1788 obj, \
1789 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
1790 (closure)->do_oop##nv_suffix(p), \
1791 assert_is_in_closed_subset) \
1792 return size_helper(); \
1793 }
1794 #endif // !SERIALGC
1795
1796 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
1797 \
1798 int instanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \
1799 OopClosureType* closure, \
1800 MemRegion mr) { \
1801 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
1802 if (closure->do_header()) { \
1803 obj->oop_iterate_header(closure, mr); \
1804 } \
1805 InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
1806 obj, mr.start(), mr.end(), \
1807 (closure)->do_oop##nv_suffix(p), \
1808 assert_is_in_closed_subset) \
1809 return size_helper(); \
1810 }
1811
1812 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
1813 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
1814 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
1815 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
1816 #ifndef SERIALGC
1817 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
1818 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
1819 #endif // !SERIALGC
1820
1821 int instanceKlass::oop_adjust_pointers(oop obj) {
1822 int size = size_helper();
1823 InstanceKlass_OOP_MAP_ITERATE( \
1824 obj, \
1825 MarkSweep::adjust_pointer(p), \
1826 assert_is_in)
1827 obj->adjust_header();
1828 return size;
1829 }
1830
1831 #ifndef SERIALGC
1832 void instanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
1833 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
1834 obj, \
1835 if (PSScavenge::should_scavenge(p)) { \
1836 pm->claim_or_forward_depth(p); \
1837 }, \
1838 assert_nothing )
1839 }
1840
1841 int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
1842 InstanceKlass_OOP_MAP_ITERATE( \
1843 obj, \
1844 PSParallelCompact::adjust_pointer(p), \
1845 assert_nothing)
1846 return size_helper();
1847 }
1848
1849 #endif // SERIALGC
1850
1851 // This klass is alive but the implementor link is not followed/updated.
1852 // Subklass and sibling links are handled by Klass::follow_weak_klass_links
1853
1854 void instanceKlass::follow_weak_klass_links(
1855 BoolObjectClosure* is_alive, OopClosure* keep_alive) {
1856 assert(is_alive->do_object_b(as_klassOop()), "this oop should be live");
1857
1858 if (is_interface()) {
1859 if (ClassUnloading) {
1860 klassOop impl = implementor();
1861 if (impl != NULL) {
1862 if (!is_alive->do_object_b(impl)) {
1863 // remove this guy
1864 *adr_implementor() = NULL;
1865 }
1866 }
1867 } else {
1868 assert(adr_implementor() != NULL, "just checking");
1869 keep_alive->do_oop(adr_implementor());
1870 }
1871 }
1872
1873 Klass::follow_weak_klass_links(is_alive, keep_alive);
1874 }
1875
1876 void instanceKlass::remove_unshareable_info() {
1877 Klass::remove_unshareable_info();
1878 init_implementor();
1879 }
1880
1881 static void clear_all_breakpoints(methodOop m) {
1882 m->clear_all_breakpoints();
1883 }
1884
1885 void instanceKlass::release_C_heap_structures() {
1886 // Deallocate oop map cache
1887 if (_oop_map_cache != NULL) {
1888 delete _oop_map_cache;
1889 _oop_map_cache = NULL;
1890 }
1891
1892 // Deallocate JNI identifiers for jfieldIDs
1893 JNIid::deallocate(jni_ids());
1894 set_jni_ids(NULL);
1895
1896 jmethodID* jmeths = methods_jmethod_ids_acquire();
1897 if (jmeths != (jmethodID*)NULL) {
1898 release_set_methods_jmethod_ids(NULL);
1899 FreeHeap(jmeths);
1900 }
1901
1902 int* indices = methods_cached_itable_indices_acquire();
1903 if (indices != (int*)NULL) {
1904 release_set_methods_cached_itable_indices(NULL);
1905 FreeHeap(indices);
1906 }
1907
1908 // release dependencies
1909 nmethodBucket* b = _dependencies;
1910 _dependencies = NULL;
1911 while (b != NULL) {
1912 nmethodBucket* next = b->next();
1913 delete b;
1914 b = next;
1915 }
1916
1917 // Deallocate breakpoint records
1918 if (breakpoints() != 0x0) {
1919 methods_do(clear_all_breakpoints);
1920 assert(breakpoints() == 0x0, "should have cleared breakpoints");
1921 }
1922
1923 // deallocate information about previous versions
1924 if (_previous_versions != NULL) {
1925 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
1926 PreviousVersionNode * pv_node = _previous_versions->at(i);
1927 delete pv_node;
1928 }
1929 delete _previous_versions;
1930 _previous_versions = NULL;
1931 }
1932
1933 // deallocate the cached class file
1934 if (_cached_class_file_bytes != NULL) {
1935 os::free(_cached_class_file_bytes, mtClass);
1936 _cached_class_file_bytes = NULL;
1937 _cached_class_file_len = 0;
1938 }
1939
1940 // Decrement symbol reference counts associated with the unloaded class.
1941 if (_name != NULL) _name->decrement_refcount();
1942 // unreference array name derived from this class name (arrays of an unloaded
1943 // class can't be referenced anymore).
1944 if (_array_name != NULL) _array_name->decrement_refcount();
1945 if (_source_file_name != NULL) _source_file_name->decrement_refcount();
1946 // walk constant pool and decrement symbol reference counts
1947 _constants->unreference_symbols();
1948
1949 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(u1, _source_debug_extension, mtClass);
1950 }
1951
1952 void instanceKlass::set_source_file_name(Symbol* n) {
1953 _source_file_name = n;
1954 if (_source_file_name != NULL) _source_file_name->increment_refcount();
1955 }
1956
1957 void instanceKlass::set_source_debug_extension(char* array, int length) {
1958 if (array == NULL) {
1959 _source_debug_extension = NULL;
1960 } else {
1961 // Adding one to the attribute length in order to store a null terminator
1962 // character could cause an overflow because the attribute length is
1963 // already coded with an u4 in the classfile, but in practice, it's
1964 // unlikely to happen.
1965 assert((length+1) > length, "Overflow checking");
1966 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
1967 for (int i = 0; i < length; i++) {
1968 sde[i] = array[i];
1969 }
1970 sde[length] = '\0';
1971 _source_debug_extension = (char*)sde;
1972 }
1973 }
1974
1975 address instanceKlass::static_field_addr(int offset) {
1976 return (address)(offset + instanceMirrorKlass::offset_of_static_fields() + (intptr_t)java_mirror());
1977 }
1978
1979
1980 const char* instanceKlass::signature_name() const {
1981 const char* src = (const char*) (name()->as_C_string());
1982 const int src_length = (int)strlen(src);
1983 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
1984 int src_index = 0;
1985 int dest_index = 0;
1986 dest[dest_index++] = 'L';
1987 while (src_index < src_length) {
1988 dest[dest_index++] = src[src_index++];
1989 }
1990 dest[dest_index++] = ';';
1991 dest[dest_index] = '\0';
1992 return dest;
1993 }
1994
1995 // different verisons of is_same_class_package
1996 bool instanceKlass::is_same_class_package(klassOop class2) {
1997 klassOop class1 = as_klassOop();
1998 oop classloader1 = instanceKlass::cast(class1)->class_loader();
1999 Symbol* classname1 = Klass::cast(class1)->name();
2000
2001 if (Klass::cast(class2)->oop_is_objArray()) {
2002 class2 = objArrayKlass::cast(class2)->bottom_klass();
2003 }
2004 oop classloader2;
2005 if (Klass::cast(class2)->oop_is_instance()) {
2006 classloader2 = instanceKlass::cast(class2)->class_loader();
2007 } else {
2008 assert(Klass::cast(class2)->oop_is_typeArray(), "should be type array");
2009 classloader2 = NULL;
2010 }
2011 Symbol* classname2 = Klass::cast(class2)->name();
2012
2013 return instanceKlass::is_same_class_package(classloader1, classname1,
2014 classloader2, classname2);
2015 }
2016
2017 bool instanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
2018 klassOop class1 = as_klassOop();
2019 oop classloader1 = instanceKlass::cast(class1)->class_loader();
2020 Symbol* classname1 = Klass::cast(class1)->name();
2021
2022 return instanceKlass::is_same_class_package(classloader1, classname1,
2023 classloader2, classname2);
2024 }
2025
2026 // return true if two classes are in the same package, classloader
2027 // and classname information is enough to determine a class's package
2028 bool instanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
2029 oop class_loader2, Symbol* class_name2) {
2030 if (class_loader1 != class_loader2) {
2031 return false;
2032 } else if (class_name1 == class_name2) {
2033 return true; // skip painful bytewise comparison
2034 } else {
2035 ResourceMark rm;
2036
2037 // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
2038 // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
2039 // Otherwise, we just compare jbyte values between the strings.
2040 const jbyte *name1 = class_name1->base();
2041 const jbyte *name2 = class_name2->base();
2042
2043 const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
2044 const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
2045
2046 if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
2047 // One of the two doesn't have a package. Only return true
2048 // if the other one also doesn't have a package.
2049 return last_slash1 == last_slash2;
2050 } else {
2051 // Skip over '['s
2052 if (*name1 == '[') {
2053 do {
2054 name1++;
2055 } while (*name1 == '[');
2056 if (*name1 != 'L') {
2057 // Something is terribly wrong. Shouldn't be here.
2058 return false;
2059 }
2060 }
2061 if (*name2 == '[') {
2062 do {
2063 name2++;
2064 } while (*name2 == '[');
2065 if (*name2 != 'L') {
2066 // Something is terribly wrong. Shouldn't be here.
2067 return false;
2068 }
2069 }
2070
2071 // Check that package part is identical
2072 int length1 = last_slash1 - name1;
2073 int length2 = last_slash2 - name2;
2074
2075 return UTF8::equal(name1, length1, name2, length2);
2076 }
2077 }
2078 }
2079
2080 // Returns true iff super_method can be overridden by a method in targetclassname
2081 // See JSL 3rd edition 8.4.6.1
2082 // Assumes name-signature match
2083 // "this" is instanceKlass of super_method which must exist
2084 // note that the instanceKlass of the method in the targetclassname has not always been created yet
2085 bool instanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2086 // Private methods can not be overridden
2087 if (super_method->is_private()) {
2088 return false;
2089 }
2090 // If super method is accessible, then override
2091 if ((super_method->is_protected()) ||
2092 (super_method->is_public())) {
2093 return true;
2094 }
2095 // Package-private methods are not inherited outside of package
2096 assert(super_method->is_package_private(), "must be package private");
2097 return(is_same_class_package(targetclassloader(), targetclassname));
2098 }
2099
2100 /* defined for now in jvm.cpp, for historical reasons *--
2101 klassOop instanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2102 Symbol*& simple_name_result, TRAPS) {
2103 ...
2104 }
2105 */
2106
2107 // tell if two classes have the same enclosing class (at package level)
2108 bool instanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2109 klassOop class2_oop, TRAPS) {
2110 if (class2_oop == class1->as_klassOop()) return true;
2111 if (!Klass::cast(class2_oop)->oop_is_instance()) return false;
2112 instanceKlassHandle class2(THREAD, class2_oop);
2113
2114 // must be in same package before we try anything else
2115 if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2116 return false;
2117
2118 // As long as there is an outer1.getEnclosingClass,
2119 // shift the search outward.
2120 instanceKlassHandle outer1 = class1;
2121 for (;;) {
2122 // As we walk along, look for equalities between outer1 and class2.
2123 // Eventually, the walks will terminate as outer1 stops
2124 // at the top-level class around the original class.
2125 bool ignore_inner_is_member;
2126 klassOop next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2127 CHECK_false);
2128 if (next == NULL) break;
2129 if (next == class2()) return true;
2130 outer1 = instanceKlassHandle(THREAD, next);
2131 }
2132
2133 // Now do the same for class2.
2134 instanceKlassHandle outer2 = class2;
2135 for (;;) {
2136 bool ignore_inner_is_member;
2137 klassOop next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2138 CHECK_false);
2139 if (next == NULL) break;
2140 // Might as well check the new outer against all available values.
2141 if (next == class1()) return true;
2142 if (next == outer1()) return true;
2143 outer2 = instanceKlassHandle(THREAD, next);
2144 }
2145
2146 // If by this point we have not found an equality between the
2147 // two classes, we know they are in separate package members.
2148 return false;
2149 }
2150
2151
2152 jint instanceKlass::compute_modifier_flags(TRAPS) const {
2153 klassOop k = as_klassOop();
2154 jint access = access_flags().as_int();
2155
2156 // But check if it happens to be member class.
2157 instanceKlassHandle ik(THREAD, k);
2158 InnerClassesIterator iter(ik);
2159 for (; !iter.done(); iter.next()) {
2160 int ioff = iter.inner_class_info_index();
2161 // Inner class attribute can be zero, skip it.
2162 // Strange but true: JVM spec. allows null inner class refs.
2163 if (ioff == 0) continue;
2164
2165 // only look at classes that are already loaded
2166 // since we are looking for the flags for our self.
2167 Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2168 if ((ik->name() == inner_name)) {
2169 // This is really a member class.
2170 access = iter.inner_access_flags();
2171 break;
2172 }
2173 }
2174 // Remember to strip ACC_SUPER bit
2175 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2176 }
2177
2178 jint instanceKlass::jvmti_class_status() const {
2179 jint result = 0;
2180
2181 if (is_linked()) {
2182 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2183 }
2184
2185 if (is_initialized()) {
2186 assert(is_linked(), "Class status is not consistent");
2187 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2188 }
2189 if (is_in_error_state()) {
2190 result |= JVMTI_CLASS_STATUS_ERROR;
2191 }
2192 return result;
2193 }
2194
2195 methodOop instanceKlass::method_at_itable(klassOop holder, int index, TRAPS) {
2196 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2197 int method_table_offset_in_words = ioe->offset()/wordSize;
2198 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2199 / itableOffsetEntry::size();
2200
2201 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2202 // If the interface isn't implemented by the receiver class,
2203 // the VM should throw IncompatibleClassChangeError.
2204 if (cnt >= nof_interfaces) {
2205 THROW_0(vmSymbols::java_lang_IncompatibleClassChangeError());
2206 }
2207
2208 klassOop ik = ioe->interface_klass();
2209 if (ik == holder) break;
2210 }
2211
2212 itableMethodEntry* ime = ioe->first_method_entry(as_klassOop());
2213 methodOop m = ime[index].method();
2214 if (m == NULL) {
2215 THROW_0(vmSymbols::java_lang_AbstractMethodError());
2216 }
2217 return m;
2218 }
2219
2220 // On-stack replacement stuff
2221 void instanceKlass::add_osr_nmethod(nmethod* n) {
2222 // only one compilation can be active
2223 NEEDS_CLEANUP
2224 // This is a short non-blocking critical region, so the no safepoint check is ok.
2225 OsrList_lock->lock_without_safepoint_check();
2226 assert(n->is_osr_method(), "wrong kind of nmethod");
2227 n->set_osr_link(osr_nmethods_head());
2228 set_osr_nmethods_head(n);
2229 // Raise the highest osr level if necessary
2230 if (TieredCompilation) {
2231 methodOop m = n->method();
2232 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2233 }
2234 // Remember to unlock again
2235 OsrList_lock->unlock();
2236
2237 // Get rid of the osr methods for the same bci that have lower levels.
2238 if (TieredCompilation) {
2239 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2240 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2241 if (inv != NULL && inv->is_in_use()) {
2242 inv->make_not_entrant();
2243 }
2244 }
2245 }
2246 }
2247
2248
2249 void instanceKlass::remove_osr_nmethod(nmethod* n) {
2250 // This is a short non-blocking critical region, so the no safepoint check is ok.
2251 OsrList_lock->lock_without_safepoint_check();
2252 assert(n->is_osr_method(), "wrong kind of nmethod");
2253 nmethod* last = NULL;
2254 nmethod* cur = osr_nmethods_head();
2255 int max_level = CompLevel_none; // Find the max comp level excluding n
2256 methodOop m = n->method();
2257 // Search for match
2258 while(cur != NULL && cur != n) {
2259 if (TieredCompilation) {
2260 // Find max level before n
2261 max_level = MAX2(max_level, cur->comp_level());
2262 }
2263 last = cur;
2264 cur = cur->osr_link();
2265 }
2266 nmethod* next = NULL;
2267 if (cur == n) {
2268 next = cur->osr_link();
2269 if (last == NULL) {
2270 // Remove first element
2271 set_osr_nmethods_head(next);
2272 } else {
2273 last->set_osr_link(next);
2274 }
2275 }
2276 n->set_osr_link(NULL);
2277 if (TieredCompilation) {
2278 cur = next;
2279 while (cur != NULL) {
2280 // Find max level after n
2281 max_level = MAX2(max_level, cur->comp_level());
2282 cur = cur->osr_link();
2283 }
2284 m->set_highest_osr_comp_level(max_level);
2285 }
2286 // Remember to unlock again
2287 OsrList_lock->unlock();
2288 }
2289
2290 nmethod* instanceKlass::lookup_osr_nmethod(const methodOop m, int bci, int comp_level, bool match_level) const {
2291 // This is a short non-blocking critical region, so the no safepoint check is ok.
2292 OsrList_lock->lock_without_safepoint_check();
2293 nmethod* osr = osr_nmethods_head();
2294 nmethod* best = NULL;
2295 while (osr != NULL) {
2296 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2297 // There can be a time when a c1 osr method exists but we are waiting
2298 // for a c2 version. When c2 completes its osr nmethod we will trash
2299 // the c1 version and only be able to find the c2 version. However
2300 // while we overflow in the c1 code at back branches we don't want to
2301 // try and switch to the same code as we are already running
2302
2303 if (osr->method() == m &&
2304 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2305 if (match_level) {
2306 if (osr->comp_level() == comp_level) {
2307 // Found a match - return it.
2308 OsrList_lock->unlock();
2309 return osr;
2310 }
2311 } else {
2312 if (best == NULL || (osr->comp_level() > best->comp_level())) {
2313 if (osr->comp_level() == CompLevel_highest_tier) {
2314 // Found the best possible - return it.
2315 OsrList_lock->unlock();
2316 return osr;
2317 }
2318 best = osr;
2319 }
2320 }
2321 }
2322 osr = osr->osr_link();
2323 }
2324 OsrList_lock->unlock();
2325 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2326 return best;
2327 }
2328 return NULL;
2329 }
2330
2331 // -----------------------------------------------------------------------------------------------------
2332 #ifndef PRODUCT
2333
2334 // Printing
2335
2336 #define BULLET " - "
2337
2338 void FieldPrinter::do_field(fieldDescriptor* fd) {
2339 _st->print(BULLET);
2340 if (_obj == NULL) {
2341 fd->print_on(_st);
2342 _st->cr();
2343 } else {
2344 fd->print_on_for(_st, _obj);
2345 _st->cr();
2346 }
2347 }
2348
2349
2350 void instanceKlass::oop_print_on(oop obj, outputStream* st) {
2351 Klass::oop_print_on(obj, st);
2352
2353 if (as_klassOop() == SystemDictionary::String_klass()) {
2354 typeArrayOop value = java_lang_String::value(obj);
2355 juint offset = java_lang_String::offset(obj);
2356 juint length = java_lang_String::length(obj);
2357 if (value != NULL &&
2358 value->is_typeArray() &&
2359 offset <= (juint) value->length() &&
2360 offset + length <= (juint) value->length()) {
2361 st->print(BULLET"string: ");
2362 Handle h_obj(obj);
2363 java_lang_String::print(h_obj, st);
2364 st->cr();
2365 if (!WizardMode) return; // that is enough
2366 }
2367 }
2368
2369 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
2370 FieldPrinter print_field(st, obj);
2371 do_nonstatic_fields(&print_field);
2372
2373 if (as_klassOop() == SystemDictionary::Class_klass()) {
2374 st->print(BULLET"signature: ");
2375 java_lang_Class::print_signature(obj, st);
2376 st->cr();
2377 klassOop mirrored_klass = java_lang_Class::as_klassOop(obj);
2378 st->print(BULLET"fake entry for mirror: ");
2379 mirrored_klass->print_value_on(st);
2380 st->cr();
2381 st->print(BULLET"fake entry resolved_constructor: ");
2382 methodOop ctor = java_lang_Class::resolved_constructor(obj);
2383 ctor->print_value_on(st);
2384 klassOop array_klass = java_lang_Class::array_klass(obj);
2385 st->cr();
2386 st->print(BULLET"fake entry for array: ");
2387 array_klass->print_value_on(st);
2388 st->cr();
2389 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
2390 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
2391 klassOop real_klass = java_lang_Class::as_klassOop(obj);
2392 if (real_klass != NULL && real_klass->klass_part()->oop_is_instance()) {
2393 instanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
2394 }
2395 } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
2396 st->print(BULLET"signature: ");
2397 java_lang_invoke_MethodType::print_signature(obj, st);
2398 st->cr();
2399 }
2400 }
2401
2402 #endif //PRODUCT
2403
2404 void instanceKlass::oop_print_value_on(oop obj, outputStream* st) {
2405 st->print("a ");
2406 name()->print_value_on(st);
2407 obj->print_address_on(st);
2408 if (as_klassOop() == SystemDictionary::String_klass()
2409 && java_lang_String::value(obj) != NULL) {
2410 ResourceMark rm;
2411 int len = java_lang_String::length(obj);
2412 int plen = (len < 24 ? len : 12);
2413 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
2414 st->print(" = \"%s\"", str);
2415 if (len > plen)
2416 st->print("...[%d]", len);
2417 } else if (as_klassOop() == SystemDictionary::Class_klass()) {
2418 klassOop k = java_lang_Class::as_klassOop(obj);
2419 st->print(" = ");
2420 if (k != NULL) {
2421 k->print_value_on(st);
2422 } else {
2423 const char* tname = type2name(java_lang_Class::primitive_type(obj));
2424 st->print("%s", tname ? tname : "type?");
2425 }
2426 } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
2427 st->print(" = ");
2428 java_lang_invoke_MethodType::print_signature(obj, st);
2429 } else if (java_lang_boxing_object::is_instance(obj)) {
2430 st->print(" = ");
2431 java_lang_boxing_object::print(obj, st);
2432 }
2433 }
2434
2435 const char* instanceKlass::internal_name() const {
2436 return external_name();
2437 }
2438
2439 // Verification
2440
2441 class VerifyFieldClosure: public OopClosure {
2442 protected:
2443 template <class T> void do_oop_work(T* p) {
2444 guarantee(Universe::heap()->is_in_closed_subset(p), "should be in heap");
2445 oop obj = oopDesc::load_decode_heap_oop(p);
2446 if (!obj->is_oop_or_null()) {
2447 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
2448 Universe::print();
2449 guarantee(false, "boom");
2450 }
2451 }
2452 public:
2453 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
2454 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
2455 };
2456
2457 void instanceKlass::oop_verify_on(oop obj, outputStream* st) {
2458 Klass::oop_verify_on(obj, st);
2459 VerifyFieldClosure blk;
2460 oop_oop_iterate(obj, &blk);
2461 }
2462
2463 // JNIid class for jfieldIDs only
2464 // Note to reviewers:
2465 // These JNI functions are just moved over to column 1 and not changed
2466 // in the compressed oops workspace.
2467 JNIid::JNIid(klassOop holder, int offset, JNIid* next) {
2468 _holder = holder;
2469 _offset = offset;
2470 _next = next;
2471 debug_only(_is_static_field_id = false;)
2472 }
2473
2474
2475 JNIid* JNIid::find(int offset) {
2476 JNIid* current = this;
2477 while (current != NULL) {
2478 if (current->offset() == offset) return current;
2479 current = current->next();
2480 }
2481 return NULL;
2482 }
2483
2484 void JNIid::oops_do(OopClosure* f) {
2485 for (JNIid* cur = this; cur != NULL; cur = cur->next()) {
2486 f->do_oop(cur->holder_addr());
2487 }
2488 }
2489
2490 void JNIid::deallocate(JNIid* current) {
2491 while (current != NULL) {
2492 JNIid* next = current->next();
2493 delete current;
2494 current = next;
2495 }
2496 }
2497
2498
2499 void JNIid::verify(klassOop holder) {
2500 int first_field_offset = instanceMirrorKlass::offset_of_static_fields();
2501 int end_field_offset;
2502 end_field_offset = first_field_offset + (instanceKlass::cast(holder)->static_field_size() * wordSize);
2503
2504 JNIid* current = this;
2505 while (current != NULL) {
2506 guarantee(current->holder() == holder, "Invalid klass in JNIid");
2507 #ifdef ASSERT
2508 int o = current->offset();
2509 if (current->is_static_field_id()) {
2510 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
2511 }
2512 #endif
2513 current = current->next();
2514 }
2515 }
2516
2517
2518 #ifdef ASSERT
2519 void instanceKlass::set_init_state(ClassState state) {
2520 bool good_state = as_klassOop()->is_shared() ? (_init_state <= state)
2521 : (_init_state < state);
2522 assert(good_state || state == allocated, "illegal state transition");
2523 _init_state = (u1)state;
2524 }
2525 #endif
2526
2527
2528 // RedefineClasses() support for previous versions:
2529
2530 // Add an information node that contains weak references to the
2531 // interesting parts of the previous version of the_class.
2532 // This is also where we clean out any unused weak references.
2533 // Note that while we delete nodes from the _previous_versions
2534 // array, we never delete the array itself until the klass is
2535 // unloaded. The has_been_redefined() query depends on that fact.
2536 //
2537 void instanceKlass::add_previous_version(instanceKlassHandle ikh,
2538 BitMap* emcp_methods, int emcp_method_count) {
2539 assert(Thread::current()->is_VM_thread(),
2540 "only VMThread can add previous versions");
2541
2542 if (_previous_versions == NULL) {
2543 // This is the first previous version so make some space.
2544 // Start with 2 elements under the assumption that the class
2545 // won't be redefined much.
2546 _previous_versions = new (ResourceObj::C_HEAP, mtClass)
2547 GrowableArray<PreviousVersionNode *>(2, true);
2548 }
2549
2550 // RC_TRACE macro has an embedded ResourceMark
2551 RC_TRACE(0x00000100, ("adding previous version ref for %s @%d, EMCP_cnt=%d",
2552 ikh->external_name(), _previous_versions->length(), emcp_method_count));
2553 constantPoolHandle cp_h(ikh->constants());
2554 jobject cp_ref;
2555 if (cp_h->is_shared()) {
2556 // a shared ConstantPool requires a regular reference; a weak
2557 // reference would be collectible
2558 cp_ref = JNIHandles::make_global(cp_h);
2559 } else {
2560 cp_ref = JNIHandles::make_weak_global(cp_h);
2561 }
2562 PreviousVersionNode * pv_node = NULL;
2563 objArrayOop old_methods = ikh->methods();
2564
2565 if (emcp_method_count == 0) {
2566 // non-shared ConstantPool gets a weak reference
2567 pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), NULL);
2568 RC_TRACE(0x00000400,
2569 ("add: all methods are obsolete; flushing any EMCP weak refs"));
2570 } else {
2571 int local_count = 0;
2572 GrowableArray<jweak>* method_refs = new (ResourceObj::C_HEAP, mtClass)
2573 GrowableArray<jweak>(emcp_method_count, true);
2574 for (int i = 0; i < old_methods->length(); i++) {
2575 if (emcp_methods->at(i)) {
2576 // this old method is EMCP so save a weak ref
2577 methodOop old_method = (methodOop) old_methods->obj_at(i);
2578 methodHandle old_method_h(old_method);
2579 jweak method_ref = JNIHandles::make_weak_global(old_method_h);
2580 method_refs->append(method_ref);
2581 if (++local_count >= emcp_method_count) {
2582 // no more EMCP methods so bail out now
2583 break;
2584 }
2585 }
2586 }
2587 // non-shared ConstantPool gets a weak reference
2588 pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), method_refs);
2589 }
2590
2591 _previous_versions->append(pv_node);
2592
2593 // Using weak references allows the interesting parts of previous
2594 // classes to be GC'ed when they are no longer needed. Since the
2595 // caller is the VMThread and we are at a safepoint, this is a good
2596 // time to clear out unused weak references.
2597
2598 RC_TRACE(0x00000400, ("add: previous version length=%d",
2599 _previous_versions->length()));
2600
2601 // skip the last entry since we just added it
2602 for (int i = _previous_versions->length() - 2; i >= 0; i--) {
2603 // check the previous versions array for a GC'ed weak refs
2604 pv_node = _previous_versions->at(i);
2605 cp_ref = pv_node->prev_constant_pool();
2606 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
2607 if (cp_ref == NULL) {
2608 delete pv_node;
2609 _previous_versions->remove_at(i);
2610 // Since we are traversing the array backwards, we don't have to
2611 // do anything special with the index.
2612 continue; // robustness
2613 }
2614
2615 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2616 if (cp == NULL) {
2617 // this entry has been GC'ed so remove it
2618 delete pv_node;
2619 _previous_versions->remove_at(i);
2620 // Since we are traversing the array backwards, we don't have to
2621 // do anything special with the index.
2622 continue;
2623 } else {
2624 RC_TRACE(0x00000400, ("add: previous version @%d is alive", i));
2625 }
2626
2627 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2628 if (method_refs != NULL) {
2629 RC_TRACE(0x00000400, ("add: previous methods length=%d",
2630 method_refs->length()));
2631 for (int j = method_refs->length() - 1; j >= 0; j--) {
2632 jweak method_ref = method_refs->at(j);
2633 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
2634 if (method_ref == NULL) {
2635 method_refs->remove_at(j);
2636 // Since we are traversing the array backwards, we don't have to
2637 // do anything special with the index.
2638 continue; // robustness
2639 }
2640
2641 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2642 if (method == NULL || emcp_method_count == 0) {
2643 // This method entry has been GC'ed or the current
2644 // RedefineClasses() call has made all methods obsolete
2645 // so remove it.
2646 JNIHandles::destroy_weak_global(method_ref);
2647 method_refs->remove_at(j);
2648 } else {
2649 // RC_TRACE macro has an embedded ResourceMark
2650 RC_TRACE(0x00000400,
2651 ("add: %s(%s): previous method @%d in version @%d is alive",
2652 method->name()->as_C_string(), method->signature()->as_C_string(),
2653 j, i));
2654 }
2655 }
2656 }
2657 }
2658
2659 int obsolete_method_count = old_methods->length() - emcp_method_count;
2660
2661 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
2662 _previous_versions->length() > 1) {
2663 // We have a mix of obsolete and EMCP methods. If there is more
2664 // than the previous version that we just added, then we have to
2665 // clear out any matching EMCP method entries the hard way.
2666 int local_count = 0;
2667 for (int i = 0; i < old_methods->length(); i++) {
2668 if (!emcp_methods->at(i)) {
2669 // only obsolete methods are interesting
2670 methodOop old_method = (methodOop) old_methods->obj_at(i);
2671 Symbol* m_name = old_method->name();
2672 Symbol* m_signature = old_method->signature();
2673
2674 // skip the last entry since we just added it
2675 for (int j = _previous_versions->length() - 2; j >= 0; j--) {
2676 // check the previous versions array for a GC'ed weak refs
2677 pv_node = _previous_versions->at(j);
2678 cp_ref = pv_node->prev_constant_pool();
2679 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
2680 if (cp_ref == NULL) {
2681 delete pv_node;
2682 _previous_versions->remove_at(j);
2683 // Since we are traversing the array backwards, we don't have to
2684 // do anything special with the index.
2685 continue; // robustness
2686 }
2687
2688 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2689 if (cp == NULL) {
2690 // this entry has been GC'ed so remove it
2691 delete pv_node;
2692 _previous_versions->remove_at(j);
2693 // Since we are traversing the array backwards, we don't have to
2694 // do anything special with the index.
2695 continue;
2696 }
2697
2698 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2699 if (method_refs == NULL) {
2700 // We have run into a PreviousVersion generation where
2701 // all methods were made obsolete during that generation's
2702 // RedefineClasses() operation. At the time of that
2703 // operation, all EMCP methods were flushed so we don't
2704 // have to go back any further.
2705 //
2706 // A NULL method_refs is different than an empty method_refs.
2707 // We cannot infer any optimizations about older generations
2708 // from an empty method_refs for the current generation.
2709 break;
2710 }
2711
2712 for (int k = method_refs->length() - 1; k >= 0; k--) {
2713 jweak method_ref = method_refs->at(k);
2714 assert(method_ref != NULL,
2715 "weak method ref was unexpectedly cleared");
2716 if (method_ref == NULL) {
2717 method_refs->remove_at(k);
2718 // Since we are traversing the array backwards, we don't
2719 // have to do anything special with the index.
2720 continue; // robustness
2721 }
2722
2723 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2724 if (method == NULL) {
2725 // this method entry has been GC'ed so skip it
2726 JNIHandles::destroy_weak_global(method_ref);
2727 method_refs->remove_at(k);
2728 continue;
2729 }
2730
2731 if (method->name() == m_name &&
2732 method->signature() == m_signature) {
2733 // The current RedefineClasses() call has made all EMCP
2734 // versions of this method obsolete so mark it as obsolete
2735 // and remove the weak ref.
2736 RC_TRACE(0x00000400,
2737 ("add: %s(%s): flush obsolete method @%d in version @%d",
2738 m_name->as_C_string(), m_signature->as_C_string(), k, j));
2739
2740 method->set_is_obsolete();
2741 JNIHandles::destroy_weak_global(method_ref);
2742 method_refs->remove_at(k);
2743 break;
2744 }
2745 }
2746
2747 // The previous loop may not find a matching EMCP method, but
2748 // that doesn't mean that we can optimize and not go any
2749 // further back in the PreviousVersion generations. The EMCP
2750 // method for this generation could have already been GC'ed,
2751 // but there still may be an older EMCP method that has not
2752 // been GC'ed.
2753 }
2754
2755 if (++local_count >= obsolete_method_count) {
2756 // no more obsolete methods so bail out now
2757 break;
2758 }
2759 }
2760 }
2761 }
2762 } // end add_previous_version()
2763
2764
2765 // Determine if instanceKlass has a previous version.
2766 bool instanceKlass::has_previous_version() const {
2767 if (_previous_versions == NULL) {
2768 // no previous versions array so answer is easy
2769 return false;
2770 }
2771
2772 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
2773 // Check the previous versions array for an info node that hasn't
2774 // been GC'ed
2775 PreviousVersionNode * pv_node = _previous_versions->at(i);
2776
2777 jobject cp_ref = pv_node->prev_constant_pool();
2778 assert(cp_ref != NULL, "cp reference was unexpectedly cleared");
2779 if (cp_ref == NULL) {
2780 continue; // robustness
2781 }
2782
2783 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2784 if (cp != NULL) {
2785 // we have at least one previous version
2786 return true;
2787 }
2788
2789 // We don't have to check the method refs. If the constant pool has
2790 // been GC'ed then so have the methods.
2791 }
2792
2793 // all of the underlying nodes' info has been GC'ed
2794 return false;
2795 } // end has_previous_version()
2796
2797 methodOop instanceKlass::method_with_idnum(int idnum) {
2798 methodOop m = NULL;
2799 if (idnum < methods()->length()) {
2800 m = (methodOop) methods()->obj_at(idnum);
2801 }
2802 if (m == NULL || m->method_idnum() != idnum) {
2803 for (int index = 0; index < methods()->length(); ++index) {
2804 m = (methodOop) methods()->obj_at(index);
2805 if (m->method_idnum() == idnum) {
2806 return m;
2807 }
2808 }
2809 }
2810 return m;
2811 }
2812
2813
2814 // Set the annotation at 'idnum' to 'anno'.
2815 // We don't want to create or extend the array if 'anno' is NULL, since that is the
2816 // default value. However, if the array exists and is long enough, we must set NULL values.
2817 void instanceKlass::set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p) {
2818 objArrayOop md = *md_p;
2819 if (md != NULL && md->length() > idnum) {
2820 md->obj_at_put(idnum, anno);
2821 } else if (anno != NULL) {
2822 // create the array
2823 int length = MAX2(idnum+1, (int)_idnum_allocated_count);
2824 md = oopFactory::new_system_objArray(length, Thread::current());
2825 if (*md_p != NULL) {
2826 // copy the existing entries
2827 for (int index = 0; index < (*md_p)->length(); index++) {
2828 md->obj_at_put(index, (*md_p)->obj_at(index));
2829 }
2830 }
2831 set_annotations(md, md_p);
2832 md->obj_at_put(idnum, anno);
2833 } // if no array and idnum isn't included there is nothing to do
2834 }
2835
2836 // Construct a PreviousVersionNode entry for the array hung off
2837 // the instanceKlass.
2838 PreviousVersionNode::PreviousVersionNode(jobject prev_constant_pool,
2839 bool prev_cp_is_weak, GrowableArray<jweak>* prev_EMCP_methods) {
2840
2841 _prev_constant_pool = prev_constant_pool;
2842 _prev_cp_is_weak = prev_cp_is_weak;
2843 _prev_EMCP_methods = prev_EMCP_methods;
2844 }
2845
2846
2847 // Destroy a PreviousVersionNode
2848 PreviousVersionNode::~PreviousVersionNode() {
2849 if (_prev_constant_pool != NULL) {
2850 if (_prev_cp_is_weak) {
2851 JNIHandles::destroy_weak_global(_prev_constant_pool);
2852 } else {
2853 JNIHandles::destroy_global(_prev_constant_pool);
2854 }
2855 }
2856
2857 if (_prev_EMCP_methods != NULL) {
2858 for (int i = _prev_EMCP_methods->length() - 1; i >= 0; i--) {
2859 jweak method_ref = _prev_EMCP_methods->at(i);
2860 if (method_ref != NULL) {
2861 JNIHandles::destroy_weak_global(method_ref);
2862 }
2863 }
2864 delete _prev_EMCP_methods;
2865 }
2866 }
2867
2868
2869 // Construct a PreviousVersionInfo entry
2870 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
2871 _prev_constant_pool_handle = constantPoolHandle(); // NULL handle
2872 _prev_EMCP_method_handles = NULL;
2873
2874 jobject cp_ref = pv_node->prev_constant_pool();
2875 assert(cp_ref != NULL, "constant pool ref was unexpectedly cleared");
2876 if (cp_ref == NULL) {
2877 return; // robustness
2878 }
2879
2880 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2881 if (cp == NULL) {
2882 // Weak reference has been GC'ed. Since the constant pool has been
2883 // GC'ed, the methods have also been GC'ed.
2884 return;
2885 }
2886
2887 // make the constantPoolOop safe to return
2888 _prev_constant_pool_handle = constantPoolHandle(cp);
2889
2890 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2891 if (method_refs == NULL) {
2892 // the instanceKlass did not have any EMCP methods
2893 return;
2894 }
2895
2896 _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
2897
2898 int n_methods = method_refs->length();
2899 for (int i = 0; i < n_methods; i++) {
2900 jweak method_ref = method_refs->at(i);
2901 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
2902 if (method_ref == NULL) {
2903 continue; // robustness
2904 }
2905
2906 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2907 if (method == NULL) {
2908 // this entry has been GC'ed so skip it
2909 continue;
2910 }
2911
2912 // make the methodOop safe to return
2913 _prev_EMCP_method_handles->append(methodHandle(method));
2914 }
2915 }
2916
2917
2918 // Destroy a PreviousVersionInfo
2919 PreviousVersionInfo::~PreviousVersionInfo() {
2920 // Since _prev_EMCP_method_handles is not C-heap allocated, we
2921 // don't have to delete it.
2922 }
2923
2924
2925 // Construct a helper for walking the previous versions array
2926 PreviousVersionWalker::PreviousVersionWalker(instanceKlass *ik) {
2927 _previous_versions = ik->previous_versions();
2928 _current_index = 0;
2929 // _hm needs no initialization
2930 _current_p = NULL;
2931 }
2932
2933
2934 // Destroy a PreviousVersionWalker
2935 PreviousVersionWalker::~PreviousVersionWalker() {
2936 // Delete the current info just in case the caller didn't walk to
2937 // the end of the previous versions list. No harm if _current_p is
2938 // already NULL.
2939 delete _current_p;
2940
2941 // When _hm is destroyed, all the Handles returned in
2942 // PreviousVersionInfo objects will be destroyed.
2943 // Also, after this destructor is finished it will be
2944 // safe to delete the GrowableArray allocated in the
2945 // PreviousVersionInfo objects.
2946 }
2947
2948
2949 // Return the interesting information for the next previous version
2950 // of the klass. Returns NULL if there are no more previous versions.
2951 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
2952 if (_previous_versions == NULL) {
2953 // no previous versions so nothing to return
2954 return NULL;
2955 }
2956
2957 delete _current_p; // cleanup the previous info for the caller
2958 _current_p = NULL; // reset to NULL so we don't delete same object twice
2959
2960 int length = _previous_versions->length();
2961
2962 while (_current_index < length) {
2963 PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
2964 PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP, mtClass)
2965 PreviousVersionInfo(pv_node);
2966
2967 constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
2968 if (cp_h.is_null()) {
2969 delete pv_info;
2970
2971 // The underlying node's info has been GC'ed so try the next one.
2972 // We don't have to check the methods. If the constant pool has
2973 // GC'ed then so have the methods.
2974 continue;
2975 }
2976
2977 // Found a node with non GC'ed info so return it. The caller will
2978 // need to delete pv_info when they are done with it.
2979 _current_p = pv_info;
2980 return pv_info;
2981 }
2982
2983 // all of the underlying nodes' info has been GC'ed
2984 return NULL;
2985 } // end next_previous_version()