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 closure->do_symbol(&_source_debug_extension);
851
852 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
853 int name_index = fs.name_index();
854 closure->do_symbol(constants()->symbol_at_addr(name_index));
855 int sig_index = fs.signature_index();
856 closure->do_symbol(constants()->symbol_at_addr(sig_index));
857 }
858 }
859
860
861 klassOop instanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
862 const int n = local_interfaces()->length();
863 for (int i = 0; i < n; i++) {
864 klassOop intf1 = klassOop(local_interfaces()->obj_at(i));
865 assert(Klass::cast(intf1)->is_interface(), "just checking type");
866 // search for field in current interface
867 if (instanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
868 assert(fd->is_static(), "interface field must be static");
869 return intf1;
870 }
871 // search for field in direct superinterfaces
872 klassOop intf2 = instanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
873 if (intf2 != NULL) return intf2;
874 }
875 // otherwise field lookup fails
876 return NULL;
877 }
878
879
880 klassOop instanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
881 // search order according to newest JVM spec (5.4.3.2, p.167).
882 // 1) search for field in current klass
883 if (find_local_field(name, sig, fd)) {
884 return as_klassOop();
885 }
886 // 2) search for field recursively in direct superinterfaces
887 { klassOop intf = find_interface_field(name, sig, fd);
888 if (intf != NULL) return intf;
889 }
890 // 3) apply field lookup recursively if superclass exists
891 { klassOop supr = super();
892 if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, fd);
893 }
894 // 4) otherwise field lookup fails
895 return NULL;
896 }
897
898
899 klassOop instanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
900 // search order according to newest JVM spec (5.4.3.2, p.167).
901 // 1) search for field in current klass
902 if (find_local_field(name, sig, fd)) {
903 if (fd->is_static() == is_static) return as_klassOop();
904 }
905 // 2) search for field recursively in direct superinterfaces
906 if (is_static) {
907 klassOop intf = find_interface_field(name, sig, fd);
908 if (intf != NULL) return intf;
909 }
910 // 3) apply field lookup recursively if superclass exists
911 { klassOop supr = super();
912 if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
913 }
914 // 4) otherwise field lookup fails
915 return NULL;
916 }
917
918
919 bool instanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
920 for (JavaFieldStream fs(as_klassOop()); !fs.done(); fs.next()) {
921 if (fs.offset() == offset) {
922 fd->initialize(as_klassOop(), fs.index());
923 if (fd->is_static() == is_static) return true;
924 }
925 }
926 return false;
927 }
928
929
930 bool instanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
931 klassOop klass = as_klassOop();
932 while (klass != NULL) {
933 if (instanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
934 return true;
935 }
936 klass = Klass::cast(klass)->super();
937 }
938 return false;
939 }
940
941
942 void instanceKlass::methods_do(void f(methodOop method)) {
943 int len = methods()->length();
944 for (int index = 0; index < len; index++) {
945 methodOop m = methodOop(methods()->obj_at(index));
946 assert(m->is_method(), "must be method");
947 f(m);
948 }
949 }
950
951
952 void instanceKlass::do_local_static_fields(FieldClosure* cl) {
953 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
954 if (fs.access_flags().is_static()) {
955 fieldDescriptor fd;
956 fd.initialize(as_klassOop(), fs.index());
957 cl->do_field(&fd);
958 }
959 }
960 }
961
962
963 void instanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
964 instanceKlassHandle h_this(THREAD, as_klassOop());
965 do_local_static_fields_impl(h_this, f, CHECK);
966 }
967
968
969 void instanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
970 for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
971 if (fs.access_flags().is_static()) {
972 fieldDescriptor fd;
973 fd.initialize(this_oop(), fs.index());
974 f(&fd, CHECK);
975 }
976 }
977 }
978
979
980 static int compare_fields_by_offset(int* a, int* b) {
981 return a[0] - b[0];
982 }
983
984 void instanceKlass::do_nonstatic_fields(FieldClosure* cl) {
985 instanceKlass* super = superklass();
986 if (super != NULL) {
987 super->do_nonstatic_fields(cl);
988 }
989 fieldDescriptor fd;
990 int length = java_fields_count();
991 // In DebugInfo nonstatic fields are sorted by offset.
992 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
993 int j = 0;
994 for (int i = 0; i < length; i += 1) {
995 fd.initialize(as_klassOop(), i);
996 if (!fd.is_static()) {
997 fields_sorted[j + 0] = fd.offset();
998 fields_sorted[j + 1] = i;
999 j += 2;
1000 }
1001 }
1002 if (j > 0) {
1003 length = j;
1004 // _sort_Fn is defined in growableArray.hpp.
1005 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1006 for (int i = 0; i < length; i += 2) {
1007 fd.initialize(as_klassOop(), fields_sorted[i + 1]);
1008 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1009 cl->do_field(&fd);
1010 }
1011 }
1012 FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
1013 }
1014
1015
1016 void instanceKlass::array_klasses_do(void f(klassOop k)) {
1017 if (array_klasses() != NULL)
1018 arrayKlass::cast(array_klasses())->array_klasses_do(f);
1019 }
1020
1021
1022 void instanceKlass::with_array_klasses_do(void f(klassOop k)) {
1023 f(as_klassOop());
1024 array_klasses_do(f);
1025 }
1026
1027 #ifdef ASSERT
1028 static int linear_search(objArrayOop methods, Symbol* name, Symbol* signature) {
1029 int len = methods->length();
1030 for (int index = 0; index < len; index++) {
1031 methodOop m = (methodOop)(methods->obj_at(index));
1032 assert(m->is_method(), "must be method");
1033 if (m->signature() == signature && m->name() == name) {
1034 return index;
1035 }
1036 }
1037 return -1;
1038 }
1039 #endif
1040
1041 methodOop instanceKlass::find_method(Symbol* name, Symbol* signature) const {
1042 return instanceKlass::find_method(methods(), name, signature);
1043 }
1044
1045 methodOop instanceKlass::find_method(objArrayOop methods, Symbol* name, Symbol* signature) {
1046 int len = methods->length();
1047 // methods are sorted, so do binary search
1048 int l = 0;
1049 int h = len - 1;
1050 while (l <= h) {
1051 int mid = (l + h) >> 1;
1052 methodOop m = (methodOop)methods->obj_at(mid);
1053 assert(m->is_method(), "must be method");
1054 int res = m->name()->fast_compare(name);
1055 if (res == 0) {
1056 // found matching name; do linear search to find matching signature
1057 // first, quick check for common case
1058 if (m->signature() == signature) return m;
1059 // search downwards through overloaded methods
1060 int i;
1061 for (i = mid - 1; i >= l; i--) {
1062 methodOop m = (methodOop)methods->obj_at(i);
1063 assert(m->is_method(), "must be method");
1064 if (m->name() != name) break;
1065 if (m->signature() == signature) return m;
1066 }
1067 // search upwards
1068 for (i = mid + 1; i <= h; i++) {
1069 methodOop m = (methodOop)methods->obj_at(i);
1070 assert(m->is_method(), "must be method");
1071 if (m->name() != name) break;
1072 if (m->signature() == signature) return m;
1073 }
1074 // not found
1075 #ifdef ASSERT
1076 int index = linear_search(methods, name, signature);
1077 assert(index == -1, err_msg("binary search should have found entry %d", index));
1078 #endif
1079 return NULL;
1080 } else if (res < 0) {
1081 l = mid + 1;
1082 } else {
1083 h = mid - 1;
1084 }
1085 }
1086 #ifdef ASSERT
1087 int index = linear_search(methods, name, signature);
1088 assert(index == -1, err_msg("binary search should have found entry %d", index));
1089 #endif
1090 return NULL;
1091 }
1092
1093 methodOop instanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
1094 klassOop klass = as_klassOop();
1095 while (klass != NULL) {
1096 methodOop method = instanceKlass::cast(klass)->find_method(name, signature);
1097 if (method != NULL) return method;
1098 klass = instanceKlass::cast(klass)->super();
1099 }
1100 return NULL;
1101 }
1102
1103 // lookup a method in all the interfaces that this class implements
1104 methodOop instanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1105 Symbol* signature) const {
1106 objArrayOop all_ifs = instanceKlass::cast(as_klassOop())->transitive_interfaces();
1107 int num_ifs = all_ifs->length();
1108 instanceKlass *ik = NULL;
1109 for (int i = 0; i < num_ifs; i++) {
1110 ik = instanceKlass::cast(klassOop(all_ifs->obj_at(i)));
1111 methodOop m = ik->lookup_method(name, signature);
1112 if (m != NULL) {
1113 return m;
1114 }
1115 }
1116 return NULL;
1117 }
1118
1119 /* jni_id_for_impl for jfieldIds only */
1120 JNIid* instanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
1121 MutexLocker ml(JfieldIdCreation_lock);
1122 // Retry lookup after we got the lock
1123 JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
1124 if (probe == NULL) {
1125 // Slow case, allocate new static field identifier
1126 probe = new JNIid(this_oop->as_klassOop(), offset, this_oop->jni_ids());
1127 this_oop->set_jni_ids(probe);
1128 }
1129 return probe;
1130 }
1131
1132
1133 /* jni_id_for for jfieldIds only */
1134 JNIid* instanceKlass::jni_id_for(int offset) {
1135 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1136 if (probe == NULL) {
1137 probe = jni_id_for_impl(this->as_klassOop(), offset);
1138 }
1139 return probe;
1140 }
1141
1142 u2 instanceKlass::enclosing_method_data(int offset) {
1143 typeArrayOop inner_class_list = inner_classes();
1144 if (inner_class_list == NULL) {
1145 return 0;
1146 }
1147 int length = inner_class_list->length();
1148 if (length % inner_class_next_offset == 0) {
1149 return 0;
1150 } else {
1151 int index = length - enclosing_method_attribute_size;
1152 typeArrayHandle inner_class_list_h(inner_class_list);
1153 assert(offset < enclosing_method_attribute_size, "invalid offset");
1154 return inner_class_list_h->ushort_at(index + offset);
1155 }
1156 }
1157
1158 void instanceKlass::set_enclosing_method_indices(u2 class_index,
1159 u2 method_index) {
1160 typeArrayOop inner_class_list = inner_classes();
1161 assert (inner_class_list != NULL, "_inner_classes list is not set up");
1162 int length = inner_class_list->length();
1163 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1164 int index = length - enclosing_method_attribute_size;
1165 typeArrayHandle inner_class_list_h(inner_class_list);
1166 inner_class_list_h->ushort_at_put(
1167 index + enclosing_method_class_index_offset, class_index);
1168 inner_class_list_h->ushort_at_put(
1169 index + enclosing_method_method_index_offset, method_index);
1170 }
1171 }
1172
1173 // Lookup or create a jmethodID.
1174 // This code is called by the VMThread and JavaThreads so the
1175 // locking has to be done very carefully to avoid deadlocks
1176 // and/or other cache consistency problems.
1177 //
1178 jmethodID instanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1179 size_t idnum = (size_t)method_h->method_idnum();
1180 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1181 size_t length = 0;
1182 jmethodID id = NULL;
1183
1184 // We use a double-check locking idiom here because this cache is
1185 // performance sensitive. In the normal system, this cache only
1186 // transitions from NULL to non-NULL which is safe because we use
1187 // release_set_methods_jmethod_ids() to advertise the new cache.
1188 // A partially constructed cache should never be seen by a racing
1189 // thread. We also use release_store_ptr() to save a new jmethodID
1190 // in the cache so a partially constructed jmethodID should never be
1191 // seen either. Cache reads of existing jmethodIDs proceed without a
1192 // lock, but cache writes of a new jmethodID requires uniqueness and
1193 // creation of the cache itself requires no leaks so a lock is
1194 // generally acquired in those two cases.
1195 //
1196 // If the RedefineClasses() API has been used, then this cache can
1197 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1198 // Cache creation requires no leaks and we require safety between all
1199 // cache accesses and freeing of the old cache so a lock is generally
1200 // acquired when the RedefineClasses() API has been used.
1201
1202 if (jmeths != NULL) {
1203 // the cache already exists
1204 if (!ik_h->idnum_can_increment()) {
1205 // the cache can't grow so we can just get the current values
1206 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1207 } else {
1208 // cache can grow so we have to be more careful
1209 if (Threads::number_of_threads() == 0 ||
1210 SafepointSynchronize::is_at_safepoint()) {
1211 // we're single threaded or at a safepoint - no locking needed
1212 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1213 } else {
1214 MutexLocker ml(JmethodIdCreation_lock);
1215 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1216 }
1217 }
1218 }
1219 // implied else:
1220 // we need to allocate a cache so default length and id values are good
1221
1222 if (jmeths == NULL || // no cache yet
1223 length <= idnum || // cache is too short
1224 id == NULL) { // cache doesn't contain entry
1225
1226 // This function can be called by the VMThread so we have to do all
1227 // things that might block on a safepoint before grabbing the lock.
1228 // Otherwise, we can deadlock with the VMThread or have a cache
1229 // consistency issue. These vars keep track of what we might have
1230 // to free after the lock is dropped.
1231 jmethodID to_dealloc_id = NULL;
1232 jmethodID* to_dealloc_jmeths = NULL;
1233
1234 // may not allocate new_jmeths or use it if we allocate it
1235 jmethodID* new_jmeths = NULL;
1236 if (length <= idnum) {
1237 // allocate a new cache that might be used
1238 size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1239 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1240 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1241 // cache size is stored in element[0], other elements offset by one
1242 new_jmeths[0] = (jmethodID)size;
1243 }
1244
1245 // allocate a new jmethodID that might be used
1246 jmethodID new_id = NULL;
1247 if (method_h->is_old() && !method_h->is_obsolete()) {
1248 // The method passed in is old (but not obsolete), we need to use the current version
1249 methodOop current_method = ik_h->method_with_idnum((int)idnum);
1250 assert(current_method != NULL, "old and but not obsolete, so should exist");
1251 methodHandle current_method_h(current_method == NULL? method_h() : current_method);
1252 new_id = JNIHandles::make_jmethod_id(current_method_h);
1253 } else {
1254 // It is the current version of the method or an obsolete method,
1255 // use the version passed in
1256 new_id = JNIHandles::make_jmethod_id(method_h);
1257 }
1258
1259 if (Threads::number_of_threads() == 0 ||
1260 SafepointSynchronize::is_at_safepoint()) {
1261 // we're single threaded or at a safepoint - no locking needed
1262 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1263 &to_dealloc_id, &to_dealloc_jmeths);
1264 } else {
1265 MutexLocker ml(JmethodIdCreation_lock);
1266 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1267 &to_dealloc_id, &to_dealloc_jmeths);
1268 }
1269
1270 // The lock has been dropped so we can free resources.
1271 // Free up either the old cache or the new cache if we allocated one.
1272 if (to_dealloc_jmeths != NULL) {
1273 FreeHeap(to_dealloc_jmeths);
1274 }
1275 // free up the new ID since it wasn't needed
1276 if (to_dealloc_id != NULL) {
1277 JNIHandles::destroy_jmethod_id(to_dealloc_id);
1278 }
1279 }
1280 return id;
1281 }
1282
1283
1284 // Common code to fetch the jmethodID from the cache or update the
1285 // cache with the new jmethodID. This function should never do anything
1286 // that causes the caller to go to a safepoint or we can deadlock with
1287 // the VMThread or have cache consistency issues.
1288 //
1289 jmethodID instanceKlass::get_jmethod_id_fetch_or_update(
1290 instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1291 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1292 jmethodID** to_dealloc_jmeths_p) {
1293 assert(new_id != NULL, "sanity check");
1294 assert(to_dealloc_id_p != NULL, "sanity check");
1295 assert(to_dealloc_jmeths_p != NULL, "sanity check");
1296 assert(Threads::number_of_threads() == 0 ||
1297 SafepointSynchronize::is_at_safepoint() ||
1298 JmethodIdCreation_lock->owned_by_self(), "sanity check");
1299
1300 // reacquire the cache - we are locked, single threaded or at a safepoint
1301 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1302 jmethodID id = NULL;
1303 size_t length = 0;
1304
1305 if (jmeths == NULL || // no cache yet
1306 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
1307 if (jmeths != NULL) {
1308 // copy any existing entries from the old cache
1309 for (size_t index = 0; index < length; index++) {
1310 new_jmeths[index+1] = jmeths[index+1];
1311 }
1312 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
1313 }
1314 ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1315 } else {
1316 // fetch jmethodID (if any) from the existing cache
1317 id = jmeths[idnum+1];
1318 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
1319 }
1320 if (id == NULL) {
1321 // No matching jmethodID in the existing cache or we have a new
1322 // cache or we just grew the cache. This cache write is done here
1323 // by the first thread to win the foot race because a jmethodID
1324 // needs to be unique once it is generally available.
1325 id = new_id;
1326
1327 // The jmethodID cache can be read while unlocked so we have to
1328 // make sure the new jmethodID is complete before installing it
1329 // in the cache.
1330 OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1331 } else {
1332 *to_dealloc_id_p = new_id; // save new id for later delete
1333 }
1334 return id;
1335 }
1336
1337
1338 // Common code to get the jmethodID cache length and the jmethodID
1339 // value at index idnum if there is one.
1340 //
1341 void instanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1342 size_t idnum, size_t *length_p, jmethodID* id_p) {
1343 assert(cache != NULL, "sanity check");
1344 assert(length_p != NULL, "sanity check");
1345 assert(id_p != NULL, "sanity check");
1346
1347 // cache size is stored in element[0], other elements offset by one
1348 *length_p = (size_t)cache[0];
1349 if (*length_p <= idnum) { // cache is too short
1350 *id_p = NULL;
1351 } else {
1352 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
1353 }
1354 }
1355
1356
1357 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
1358 jmethodID instanceKlass::jmethod_id_or_null(methodOop method) {
1359 size_t idnum = (size_t)method->method_idnum();
1360 jmethodID* jmeths = methods_jmethod_ids_acquire();
1361 size_t length; // length assigned as debugging crumb
1362 jmethodID id = NULL;
1363 if (jmeths != NULL && // If there is a cache
1364 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
1365 id = jmeths[idnum+1]; // Look up the id (may be NULL)
1366 }
1367 return id;
1368 }
1369
1370
1371 // Cache an itable index
1372 void instanceKlass::set_cached_itable_index(size_t idnum, int index) {
1373 int* indices = methods_cached_itable_indices_acquire();
1374 int* to_dealloc_indices = NULL;
1375
1376 // We use a double-check locking idiom here because this cache is
1377 // performance sensitive. In the normal system, this cache only
1378 // transitions from NULL to non-NULL which is safe because we use
1379 // release_set_methods_cached_itable_indices() to advertise the
1380 // new cache. A partially constructed cache should never be seen
1381 // by a racing thread. Cache reads and writes proceed without a
1382 // lock, but creation of the cache itself requires no leaks so a
1383 // lock is generally acquired in that case.
1384 //
1385 // If the RedefineClasses() API has been used, then this cache can
1386 // grow and we'll have transitions from non-NULL to bigger non-NULL.
1387 // Cache creation requires no leaks and we require safety between all
1388 // cache accesses and freeing of the old cache so a lock is generally
1389 // acquired when the RedefineClasses() API has been used.
1390
1391 if (indices == NULL || idnum_can_increment()) {
1392 // we need a cache or the cache can grow
1393 MutexLocker ml(JNICachedItableIndex_lock);
1394 // reacquire the cache to see if another thread already did the work
1395 indices = methods_cached_itable_indices_acquire();
1396 size_t length = 0;
1397 // cache size is stored in element[0], other elements offset by one
1398 if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
1399 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1400 int* new_indices = NEW_C_HEAP_ARRAY(int, size+1, mtClass);
1401 new_indices[0] = (int)size;
1402 // copy any existing entries
1403 size_t i;
1404 for (i = 0; i < length; i++) {
1405 new_indices[i+1] = indices[i+1];
1406 }
1407 // Set all the rest to -1
1408 for (i = length; i < size; i++) {
1409 new_indices[i+1] = -1;
1410 }
1411 if (indices != NULL) {
1412 // We have an old cache to delete so save it for after we
1413 // drop the lock.
1414 to_dealloc_indices = indices;
1415 }
1416 release_set_methods_cached_itable_indices(indices = new_indices);
1417 }
1418
1419 if (idnum_can_increment()) {
1420 // this cache can grow so we have to write to it safely
1421 indices[idnum+1] = index;
1422 }
1423 } else {
1424 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
1425 }
1426
1427 if (!idnum_can_increment()) {
1428 // The cache cannot grow and this JNI itable index value does not
1429 // have to be unique like a jmethodID. If there is a race to set it,
1430 // it doesn't matter.
1431 indices[idnum+1] = index;
1432 }
1433
1434 if (to_dealloc_indices != NULL) {
1435 // we allocated a new cache so free the old one
1436 FreeHeap(to_dealloc_indices);
1437 }
1438 }
1439
1440
1441 // Retrieve a cached itable index
1442 int instanceKlass::cached_itable_index(size_t idnum) {
1443 int* indices = methods_cached_itable_indices_acquire();
1444 if (indices != NULL && ((size_t)indices[0]) > idnum) {
1445 // indices exist and are long enough, retrieve possible cached
1446 return indices[idnum+1];
1447 }
1448 return -1;
1449 }
1450
1451
1452 //
1453 // Walk the list of dependent nmethods searching for nmethods which
1454 // are dependent on the changes that were passed in and mark them for
1455 // deoptimization. Returns the number of nmethods found.
1456 //
1457 int instanceKlass::mark_dependent_nmethods(DepChange& changes) {
1458 assert_locked_or_safepoint(CodeCache_lock);
1459 int found = 0;
1460 nmethodBucket* b = _dependencies;
1461 while (b != NULL) {
1462 nmethod* nm = b->get_nmethod();
1463 // since dependencies aren't removed until an nmethod becomes a zombie,
1464 // the dependency list may contain nmethods which aren't alive.
1465 if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1466 if (TraceDependencies) {
1467 ResourceMark rm;
1468 tty->print_cr("Marked for deoptimization");
1469 tty->print_cr(" context = %s", this->external_name());
1470 changes.print();
1471 nm->print();
1472 nm->print_dependencies();
1473 }
1474 nm->mark_for_deoptimization();
1475 found++;
1476 }
1477 b = b->next();
1478 }
1479 return found;
1480 }
1481
1482
1483 //
1484 // Add an nmethodBucket to the list of dependencies for this nmethod.
1485 // It's possible that an nmethod has multiple dependencies on this klass
1486 // so a count is kept for each bucket to guarantee that creation and
1487 // deletion of dependencies is consistent.
1488 //
1489 void instanceKlass::add_dependent_nmethod(nmethod* nm) {
1490 assert_locked_or_safepoint(CodeCache_lock);
1491 nmethodBucket* b = _dependencies;
1492 nmethodBucket* last = NULL;
1493 while (b != NULL) {
1494 if (nm == b->get_nmethod()) {
1495 b->increment();
1496 return;
1497 }
1498 b = b->next();
1499 }
1500 _dependencies = new nmethodBucket(nm, _dependencies);
1501 }
1502
1503
1504 //
1505 // Decrement count of the nmethod in the dependency list and remove
1506 // the bucket competely when the count goes to 0. This method must
1507 // find a corresponding bucket otherwise there's a bug in the
1508 // recording of dependecies.
1509 //
1510 void instanceKlass::remove_dependent_nmethod(nmethod* nm) {
1511 assert_locked_or_safepoint(CodeCache_lock);
1512 nmethodBucket* b = _dependencies;
1513 nmethodBucket* last = NULL;
1514 while (b != NULL) {
1515 if (nm == b->get_nmethod()) {
1516 if (b->decrement() == 0) {
1517 if (last == NULL) {
1518 _dependencies = b->next();
1519 } else {
1520 last->set_next(b->next());
1521 }
1522 delete b;
1523 }
1524 return;
1525 }
1526 last = b;
1527 b = b->next();
1528 }
1529 #ifdef ASSERT
1530 tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1531 nm->print();
1532 #endif // ASSERT
1533 ShouldNotReachHere();
1534 }
1535
1536
1537 #ifndef PRODUCT
1538 void instanceKlass::print_dependent_nmethods(bool verbose) {
1539 nmethodBucket* b = _dependencies;
1540 int idx = 0;
1541 while (b != NULL) {
1542 nmethod* nm = b->get_nmethod();
1543 tty->print("[%d] count=%d { ", idx++, b->count());
1544 if (!verbose) {
1545 nm->print_on(tty, "nmethod");
1546 tty->print_cr(" } ");
1547 } else {
1548 nm->print();
1549 nm->print_dependencies();
1550 tty->print_cr("--- } ");
1551 }
1552 b = b->next();
1553 }
1554 }
1555
1556
1557 bool instanceKlass::is_dependent_nmethod(nmethod* nm) {
1558 nmethodBucket* b = _dependencies;
1559 while (b != NULL) {
1560 if (nm == b->get_nmethod()) {
1561 return true;
1562 }
1563 b = b->next();
1564 }
1565 return false;
1566 }
1567 #endif //PRODUCT
1568
1569
1570 #ifdef ASSERT
1571 template <class T> void assert_is_in(T *p) {
1572 T heap_oop = oopDesc::load_heap_oop(p);
1573 if (!oopDesc::is_null(heap_oop)) {
1574 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1575 assert(Universe::heap()->is_in(o), "should be in heap");
1576 }
1577 }
1578 template <class T> void assert_is_in_closed_subset(T *p) {
1579 T heap_oop = oopDesc::load_heap_oop(p);
1580 if (!oopDesc::is_null(heap_oop)) {
1581 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1582 assert(Universe::heap()->is_in_closed_subset(o), "should be in closed");
1583 }
1584 }
1585 template <class T> void assert_is_in_reserved(T *p) {
1586 T heap_oop = oopDesc::load_heap_oop(p);
1587 if (!oopDesc::is_null(heap_oop)) {
1588 oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1589 assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
1590 }
1591 }
1592 template <class T> void assert_nothing(T *p) {}
1593
1594 #else
1595 template <class T> void assert_is_in(T *p) {}
1596 template <class T> void assert_is_in_closed_subset(T *p) {}
1597 template <class T> void assert_is_in_reserved(T *p) {}
1598 template <class T> void assert_nothing(T *p) {}
1599 #endif // ASSERT
1600
1601 //
1602 // Macros that iterate over areas of oops which are specialized on type of
1603 // oop pointer either narrow or wide, depending on UseCompressedOops
1604 //
1605 // Parameters are:
1606 // T - type of oop to point to (either oop or narrowOop)
1607 // start_p - starting pointer for region to iterate over
1608 // count - number of oops or narrowOops to iterate over
1609 // do_oop - action to perform on each oop (it's arbitrary C code which
1610 // makes it more efficient to put in a macro rather than making
1611 // it a template function)
1612 // assert_fn - assert function which is template function because performance
1613 // doesn't matter when enabled.
1614 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
1615 T, start_p, count, do_oop, \
1616 assert_fn) \
1617 { \
1618 T* p = (T*)(start_p); \
1619 T* const end = p + (count); \
1620 while (p < end) { \
1621 (assert_fn)(p); \
1622 do_oop; \
1623 ++p; \
1624 } \
1625 }
1626
1627 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
1628 T, start_p, count, do_oop, \
1629 assert_fn) \
1630 { \
1631 T* const start = (T*)(start_p); \
1632 T* p = start + (count); \
1633 while (start < p) { \
1634 --p; \
1635 (assert_fn)(p); \
1636 do_oop; \
1637 } \
1638 }
1639
1640 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
1641 T, start_p, count, low, high, \
1642 do_oop, assert_fn) \
1643 { \
1644 T* const l = (T*)(low); \
1645 T* const h = (T*)(high); \
1646 assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
1647 mask_bits((intptr_t)h, sizeof(T)-1) == 0, \
1648 "bounded region must be properly aligned"); \
1649 T* p = (T*)(start_p); \
1650 T* end = p + (count); \
1651 if (p < l) p = l; \
1652 if (end > h) end = h; \
1653 while (p < end) { \
1654 (assert_fn)(p); \
1655 do_oop; \
1656 ++p; \
1657 } \
1658 }
1659
1660
1661 // The following macros call specialized macros, passing either oop or
1662 // narrowOop as the specialization type. These test the UseCompressedOops
1663 // flag.
1664 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \
1665 { \
1666 /* Compute oopmap block range. The common case \
1667 is nonstatic_oop_map_size == 1. */ \
1668 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1669 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1670 if (UseCompressedOops) { \
1671 while (map < end_map) { \
1672 InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
1673 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1674 do_oop, assert_fn) \
1675 ++map; \
1676 } \
1677 } else { \
1678 while (map < end_map) { \
1679 InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
1680 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1681 do_oop, assert_fn) \
1682 ++map; \
1683 } \
1684 } \
1685 }
1686
1687 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \
1688 { \
1689 OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \
1690 OopMapBlock* map = start_map + nonstatic_oop_map_count(); \
1691 if (UseCompressedOops) { \
1692 while (start_map < map) { \
1693 --map; \
1694 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \
1695 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1696 do_oop, assert_fn) \
1697 } \
1698 } else { \
1699 while (start_map < map) { \
1700 --map; \
1701 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \
1702 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1703 do_oop, assert_fn) \
1704 } \
1705 } \
1706 }
1707
1708 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \
1709 assert_fn) \
1710 { \
1711 /* Compute oopmap block range. The common case is \
1712 nonstatic_oop_map_size == 1, so we accept the \
1713 usually non-existent extra overhead of examining \
1714 all the maps. */ \
1715 OopMapBlock* map = start_of_nonstatic_oop_maps(); \
1716 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
1717 if (UseCompressedOops) { \
1718 while (map < end_map) { \
1719 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
1720 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
1721 low, high, \
1722 do_oop, assert_fn) \
1723 ++map; \
1724 } \
1725 } else { \
1726 while (map < end_map) { \
1727 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
1728 obj->obj_field_addr<oop>(map->offset()), map->count(), \
1729 low, high, \
1730 do_oop, assert_fn) \
1731 ++map; \
1732 } \
1733 } \
1734 }
1735
1736 void instanceKlass::oop_follow_contents(oop obj) {
1737 assert(obj != NULL, "can't follow the content of NULL object");
1738 obj->follow_header();
1739 InstanceKlass_OOP_MAP_ITERATE( \
1740 obj, \
1741 MarkSweep::mark_and_push(p), \
1742 assert_is_in_closed_subset)
1743 }
1744
1745 #ifndef SERIALGC
1746 void instanceKlass::oop_follow_contents(ParCompactionManager* cm,
1747 oop obj) {
1748 assert(obj != NULL, "can't follow the content of NULL object");
1749 obj->follow_header(cm);
1750 InstanceKlass_OOP_MAP_ITERATE( \
1751 obj, \
1752 PSParallelCompact::mark_and_push(cm, p), \
1753 assert_is_in)
1754 }
1755 #endif // SERIALGC
1756
1757 // closure's do_header() method dicates whether the given closure should be
1758 // applied to the klass ptr in the object header.
1759
1760 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
1761 \
1762 int instanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
1763 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
1764 /* header */ \
1765 if (closure->do_header()) { \
1766 obj->oop_iterate_header(closure); \
1767 } \
1768 InstanceKlass_OOP_MAP_ITERATE( \
1769 obj, \
1770 SpecializationStats:: \
1771 record_do_oop_call##nv_suffix(SpecializationStats::ik); \
1772 (closure)->do_oop##nv_suffix(p), \
1773 assert_is_in_closed_subset) \
1774 return size_helper(); \
1775 }
1776
1777 #ifndef SERIALGC
1778 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
1779 \
1780 int instanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \
1781 OopClosureType* closure) { \
1782 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
1783 /* header */ \
1784 if (closure->do_header()) { \
1785 obj->oop_iterate_header(closure); \
1786 } \
1787 /* instance variables */ \
1788 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
1789 obj, \
1790 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
1791 (closure)->do_oop##nv_suffix(p), \
1792 assert_is_in_closed_subset) \
1793 return size_helper(); \
1794 }
1795 #endif // !SERIALGC
1796
1797 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
1798 \
1799 int instanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \
1800 OopClosureType* closure, \
1801 MemRegion mr) { \
1802 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
1803 if (closure->do_header()) { \
1804 obj->oop_iterate_header(closure, mr); \
1805 } \
1806 InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
1807 obj, mr.start(), mr.end(), \
1808 (closure)->do_oop##nv_suffix(p), \
1809 assert_is_in_closed_subset) \
1810 return size_helper(); \
1811 }
1812
1813 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
1814 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
1815 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
1816 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
1817 #ifndef SERIALGC
1818 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
1819 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
1820 #endif // !SERIALGC
1821
1822 int instanceKlass::oop_adjust_pointers(oop obj) {
1823 int size = size_helper();
1824 InstanceKlass_OOP_MAP_ITERATE( \
1825 obj, \
1826 MarkSweep::adjust_pointer(p), \
1827 assert_is_in)
1828 obj->adjust_header();
1829 return size;
1830 }
1831
1832 #ifndef SERIALGC
1833 void instanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
1834 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
1835 obj, \
1836 if (PSScavenge::should_scavenge(p)) { \
1837 pm->claim_or_forward_depth(p); \
1838 }, \
1839 assert_nothing )
1840 }
1841
1842 int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
1843 InstanceKlass_OOP_MAP_ITERATE( \
1844 obj, \
1845 PSParallelCompact::adjust_pointer(p), \
1846 assert_nothing)
1847 return size_helper();
1848 }
1849
1850 #endif // SERIALGC
1851
1852 // This klass is alive but the implementor link is not followed/updated.
1853 // Subklass and sibling links are handled by Klass::follow_weak_klass_links
1854
1855 void instanceKlass::follow_weak_klass_links(
1856 BoolObjectClosure* is_alive, OopClosure* keep_alive) {
1857 assert(is_alive->do_object_b(as_klassOop()), "this oop should be live");
1858
1859 if (is_interface()) {
1860 if (ClassUnloading) {
1861 klassOop impl = implementor();
1862 if (impl != NULL) {
1863 if (!is_alive->do_object_b(impl)) {
1864 // remove this guy
1865 *adr_implementor() = NULL;
1866 }
1867 }
1868 } else {
1869 assert(adr_implementor() != NULL, "just checking");
1870 keep_alive->do_oop(adr_implementor());
1871 }
1872 }
1873
1874 Klass::follow_weak_klass_links(is_alive, keep_alive);
1875 }
1876
1877 void instanceKlass::remove_unshareable_info() {
1878 Klass::remove_unshareable_info();
1879 init_implementor();
1880 }
1881
1882 static void clear_all_breakpoints(methodOop m) {
1883 m->clear_all_breakpoints();
1884 }
1885
1886 void instanceKlass::release_C_heap_structures() {
1887 // Deallocate oop map cache
1888 if (_oop_map_cache != NULL) {
1889 delete _oop_map_cache;
1890 _oop_map_cache = NULL;
1891 }
1892
1893 // Deallocate JNI identifiers for jfieldIDs
1894 JNIid::deallocate(jni_ids());
1895 set_jni_ids(NULL);
1896
1897 jmethodID* jmeths = methods_jmethod_ids_acquire();
1898 if (jmeths != (jmethodID*)NULL) {
1899 release_set_methods_jmethod_ids(NULL);
1900 FreeHeap(jmeths);
1901 }
1902
1903 int* indices = methods_cached_itable_indices_acquire();
1904 if (indices != (int*)NULL) {
1905 release_set_methods_cached_itable_indices(NULL);
1906 FreeHeap(indices);
1907 }
1908
1909 // release dependencies
1910 nmethodBucket* b = _dependencies;
1911 _dependencies = NULL;
1912 while (b != NULL) {
1913 nmethodBucket* next = b->next();
1914 delete b;
1915 b = next;
1916 }
1917
1918 // Deallocate breakpoint records
1919 if (breakpoints() != 0x0) {
1920 methods_do(clear_all_breakpoints);
1921 assert(breakpoints() == 0x0, "should have cleared breakpoints");
1922 }
1923
1924 // deallocate information about previous versions
1925 if (_previous_versions != NULL) {
1926 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
1927 PreviousVersionNode * pv_node = _previous_versions->at(i);
1928 delete pv_node;
1929 }
1930 delete _previous_versions;
1931 _previous_versions = NULL;
1932 }
1933
1934 // deallocate the cached class file
1935 if (_cached_class_file_bytes != NULL) {
1936 os::free(_cached_class_file_bytes, mtClass);
1937 _cached_class_file_bytes = NULL;
1938 _cached_class_file_len = 0;
1939 }
1940
1941 // Decrement symbol reference counts associated with the unloaded class.
1942 if (_name != NULL) _name->decrement_refcount();
1943 // unreference array name derived from this class name (arrays of an unloaded
1944 // class can't be referenced anymore).
1945 if (_array_name != NULL) _array_name->decrement_refcount();
1946 if (_source_file_name != NULL) _source_file_name->decrement_refcount();
1947 if (_source_debug_extension != NULL) _source_debug_extension->decrement_refcount();
1948 // walk constant pool and decrement symbol reference counts
1949 _constants->unreference_symbols();
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(Symbol* n) {
1958 _source_debug_extension = n;
1959 if (_source_debug_extension != NULL) _source_debug_extension->increment_refcount();
1960 }
1961
1962 address instanceKlass::static_field_addr(int offset) {
1963 return (address)(offset + instanceMirrorKlass::offset_of_static_fields() + (intptr_t)java_mirror());
1964 }
1965
1966
1967 const char* instanceKlass::signature_name() const {
1968 const char* src = (const char*) (name()->as_C_string());
1969 const int src_length = (int)strlen(src);
1970 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
1971 int src_index = 0;
1972 int dest_index = 0;
1973 dest[dest_index++] = 'L';
1974 while (src_index < src_length) {
1975 dest[dest_index++] = src[src_index++];
1976 }
1977 dest[dest_index++] = ';';
1978 dest[dest_index] = '\0';
1979 return dest;
1980 }
1981
1982 // different verisons of is_same_class_package
1983 bool instanceKlass::is_same_class_package(klassOop class2) {
1984 klassOop class1 = as_klassOop();
1985 oop classloader1 = instanceKlass::cast(class1)->class_loader();
1986 Symbol* classname1 = Klass::cast(class1)->name();
1987
1988 if (Klass::cast(class2)->oop_is_objArray()) {
1989 class2 = objArrayKlass::cast(class2)->bottom_klass();
1990 }
1991 oop classloader2;
1992 if (Klass::cast(class2)->oop_is_instance()) {
1993 classloader2 = instanceKlass::cast(class2)->class_loader();
1994 } else {
1995 assert(Klass::cast(class2)->oop_is_typeArray(), "should be type array");
1996 classloader2 = NULL;
1997 }
1998 Symbol* classname2 = Klass::cast(class2)->name();
1999
2000 return instanceKlass::is_same_class_package(classloader1, classname1,
2001 classloader2, classname2);
2002 }
2003
2004 bool instanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
2005 klassOop class1 = as_klassOop();
2006 oop classloader1 = instanceKlass::cast(class1)->class_loader();
2007 Symbol* classname1 = Klass::cast(class1)->name();
2008
2009 return instanceKlass::is_same_class_package(classloader1, classname1,
2010 classloader2, classname2);
2011 }
2012
2013 // return true if two classes are in the same package, classloader
2014 // and classname information is enough to determine a class's package
2015 bool instanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
2016 oop class_loader2, Symbol* class_name2) {
2017 if (class_loader1 != class_loader2) {
2018 return false;
2019 } else if (class_name1 == class_name2) {
2020 return true; // skip painful bytewise comparison
2021 } else {
2022 ResourceMark rm;
2023
2024 // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
2025 // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
2026 // Otherwise, we just compare jbyte values between the strings.
2027 const jbyte *name1 = class_name1->base();
2028 const jbyte *name2 = class_name2->base();
2029
2030 const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
2031 const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
2032
2033 if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
2034 // One of the two doesn't have a package. Only return true
2035 // if the other one also doesn't have a package.
2036 return last_slash1 == last_slash2;
2037 } else {
2038 // Skip over '['s
2039 if (*name1 == '[') {
2040 do {
2041 name1++;
2042 } while (*name1 == '[');
2043 if (*name1 != 'L') {
2044 // Something is terribly wrong. Shouldn't be here.
2045 return false;
2046 }
2047 }
2048 if (*name2 == '[') {
2049 do {
2050 name2++;
2051 } while (*name2 == '[');
2052 if (*name2 != 'L') {
2053 // Something is terribly wrong. Shouldn't be here.
2054 return false;
2055 }
2056 }
2057
2058 // Check that package part is identical
2059 int length1 = last_slash1 - name1;
2060 int length2 = last_slash2 - name2;
2061
2062 return UTF8::equal(name1, length1, name2, length2);
2063 }
2064 }
2065 }
2066
2067 // Returns true iff super_method can be overridden by a method in targetclassname
2068 // See JSL 3rd edition 8.4.6.1
2069 // Assumes name-signature match
2070 // "this" is instanceKlass of super_method which must exist
2071 // note that the instanceKlass of the method in the targetclassname has not always been created yet
2072 bool instanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2073 // Private methods can not be overridden
2074 if (super_method->is_private()) {
2075 return false;
2076 }
2077 // If super method is accessible, then override
2078 if ((super_method->is_protected()) ||
2079 (super_method->is_public())) {
2080 return true;
2081 }
2082 // Package-private methods are not inherited outside of package
2083 assert(super_method->is_package_private(), "must be package private");
2084 return(is_same_class_package(targetclassloader(), targetclassname));
2085 }
2086
2087 /* defined for now in jvm.cpp, for historical reasons *--
2088 klassOop instanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2089 Symbol*& simple_name_result, TRAPS) {
2090 ...
2091 }
2092 */
2093
2094 // tell if two classes have the same enclosing class (at package level)
2095 bool instanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2096 klassOop class2_oop, TRAPS) {
2097 if (class2_oop == class1->as_klassOop()) return true;
2098 if (!Klass::cast(class2_oop)->oop_is_instance()) return false;
2099 instanceKlassHandle class2(THREAD, class2_oop);
2100
2101 // must be in same package before we try anything else
2102 if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2103 return false;
2104
2105 // As long as there is an outer1.getEnclosingClass,
2106 // shift the search outward.
2107 instanceKlassHandle outer1 = class1;
2108 for (;;) {
2109 // As we walk along, look for equalities between outer1 and class2.
2110 // Eventually, the walks will terminate as outer1 stops
2111 // at the top-level class around the original class.
2112 bool ignore_inner_is_member;
2113 klassOop next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2114 CHECK_false);
2115 if (next == NULL) break;
2116 if (next == class2()) return true;
2117 outer1 = instanceKlassHandle(THREAD, next);
2118 }
2119
2120 // Now do the same for class2.
2121 instanceKlassHandle outer2 = class2;
2122 for (;;) {
2123 bool ignore_inner_is_member;
2124 klassOop next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2125 CHECK_false);
2126 if (next == NULL) break;
2127 // Might as well check the new outer against all available values.
2128 if (next == class1()) return true;
2129 if (next == outer1()) return true;
2130 outer2 = instanceKlassHandle(THREAD, next);
2131 }
2132
2133 // If by this point we have not found an equality between the
2134 // two classes, we know they are in separate package members.
2135 return false;
2136 }
2137
2138
2139 jint instanceKlass::compute_modifier_flags(TRAPS) const {
2140 klassOop k = as_klassOop();
2141 jint access = access_flags().as_int();
2142
2143 // But check if it happens to be member class.
2144 instanceKlassHandle ik(THREAD, k);
2145 InnerClassesIterator iter(ik);
2146 for (; !iter.done(); iter.next()) {
2147 int ioff = iter.inner_class_info_index();
2148 // Inner class attribute can be zero, skip it.
2149 // Strange but true: JVM spec. allows null inner class refs.
2150 if (ioff == 0) continue;
2151
2152 // only look at classes that are already loaded
2153 // since we are looking for the flags for our self.
2154 Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2155 if ((ik->name() == inner_name)) {
2156 // This is really a member class.
2157 access = iter.inner_access_flags();
2158 break;
2159 }
2160 }
2161 // Remember to strip ACC_SUPER bit
2162 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2163 }
2164
2165 jint instanceKlass::jvmti_class_status() const {
2166 jint result = 0;
2167
2168 if (is_linked()) {
2169 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2170 }
2171
2172 if (is_initialized()) {
2173 assert(is_linked(), "Class status is not consistent");
2174 result |= JVMTI_CLASS_STATUS_INITIALIZED;
2175 }
2176 if (is_in_error_state()) {
2177 result |= JVMTI_CLASS_STATUS_ERROR;
2178 }
2179 return result;
2180 }
2181
2182 methodOop instanceKlass::method_at_itable(klassOop holder, int index, TRAPS) {
2183 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2184 int method_table_offset_in_words = ioe->offset()/wordSize;
2185 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2186 / itableOffsetEntry::size();
2187
2188 for (int cnt = 0 ; ; cnt ++, ioe ++) {
2189 // If the interface isn't implemented by the receiver class,
2190 // the VM should throw IncompatibleClassChangeError.
2191 if (cnt >= nof_interfaces) {
2192 THROW_0(vmSymbols::java_lang_IncompatibleClassChangeError());
2193 }
2194
2195 klassOop ik = ioe->interface_klass();
2196 if (ik == holder) break;
2197 }
2198
2199 itableMethodEntry* ime = ioe->first_method_entry(as_klassOop());
2200 methodOop m = ime[index].method();
2201 if (m == NULL) {
2202 THROW_0(vmSymbols::java_lang_AbstractMethodError());
2203 }
2204 return m;
2205 }
2206
2207 // On-stack replacement stuff
2208 void instanceKlass::add_osr_nmethod(nmethod* n) {
2209 // only one compilation can be active
2210 NEEDS_CLEANUP
2211 // This is a short non-blocking critical region, so the no safepoint check is ok.
2212 OsrList_lock->lock_without_safepoint_check();
2213 assert(n->is_osr_method(), "wrong kind of nmethod");
2214 n->set_osr_link(osr_nmethods_head());
2215 set_osr_nmethods_head(n);
2216 // Raise the highest osr level if necessary
2217 if (TieredCompilation) {
2218 methodOop m = n->method();
2219 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2220 }
2221 // Remember to unlock again
2222 OsrList_lock->unlock();
2223
2224 // Get rid of the osr methods for the same bci that have lower levels.
2225 if (TieredCompilation) {
2226 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2227 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2228 if (inv != NULL && inv->is_in_use()) {
2229 inv->make_not_entrant();
2230 }
2231 }
2232 }
2233 }
2234
2235
2236 void instanceKlass::remove_osr_nmethod(nmethod* n) {
2237 // This is a short non-blocking critical region, so the no safepoint check is ok.
2238 OsrList_lock->lock_without_safepoint_check();
2239 assert(n->is_osr_method(), "wrong kind of nmethod");
2240 nmethod* last = NULL;
2241 nmethod* cur = osr_nmethods_head();
2242 int max_level = CompLevel_none; // Find the max comp level excluding n
2243 methodOop m = n->method();
2244 // Search for match
2245 while(cur != NULL && cur != n) {
2246 if (TieredCompilation) {
2247 // Find max level before n
2248 max_level = MAX2(max_level, cur->comp_level());
2249 }
2250 last = cur;
2251 cur = cur->osr_link();
2252 }
2253 nmethod* next = NULL;
2254 if (cur == n) {
2255 next = cur->osr_link();
2256 if (last == NULL) {
2257 // Remove first element
2258 set_osr_nmethods_head(next);
2259 } else {
2260 last->set_osr_link(next);
2261 }
2262 }
2263 n->set_osr_link(NULL);
2264 if (TieredCompilation) {
2265 cur = next;
2266 while (cur != NULL) {
2267 // Find max level after n
2268 max_level = MAX2(max_level, cur->comp_level());
2269 cur = cur->osr_link();
2270 }
2271 m->set_highest_osr_comp_level(max_level);
2272 }
2273 // Remember to unlock again
2274 OsrList_lock->unlock();
2275 }
2276
2277 nmethod* instanceKlass::lookup_osr_nmethod(const methodOop m, int bci, int comp_level, bool match_level) const {
2278 // This is a short non-blocking critical region, so the no safepoint check is ok.
2279 OsrList_lock->lock_without_safepoint_check();
2280 nmethod* osr = osr_nmethods_head();
2281 nmethod* best = NULL;
2282 while (osr != NULL) {
2283 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2284 // There can be a time when a c1 osr method exists but we are waiting
2285 // for a c2 version. When c2 completes its osr nmethod we will trash
2286 // the c1 version and only be able to find the c2 version. However
2287 // while we overflow in the c1 code at back branches we don't want to
2288 // try and switch to the same code as we are already running
2289
2290 if (osr->method() == m &&
2291 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2292 if (match_level) {
2293 if (osr->comp_level() == comp_level) {
2294 // Found a match - return it.
2295 OsrList_lock->unlock();
2296 return osr;
2297 }
2298 } else {
2299 if (best == NULL || (osr->comp_level() > best->comp_level())) {
2300 if (osr->comp_level() == CompLevel_highest_tier) {
2301 // Found the best possible - return it.
2302 OsrList_lock->unlock();
2303 return osr;
2304 }
2305 best = osr;
2306 }
2307 }
2308 }
2309 osr = osr->osr_link();
2310 }
2311 OsrList_lock->unlock();
2312 if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2313 return best;
2314 }
2315 return NULL;
2316 }
2317
2318 // -----------------------------------------------------------------------------------------------------
2319 #ifndef PRODUCT
2320
2321 // Printing
2322
2323 #define BULLET " - "
2324
2325 void FieldPrinter::do_field(fieldDescriptor* fd) {
2326 _st->print(BULLET);
2327 if (_obj == NULL) {
2328 fd->print_on(_st);
2329 _st->cr();
2330 } else {
2331 fd->print_on_for(_st, _obj);
2332 _st->cr();
2333 }
2334 }
2335
2336
2337 void instanceKlass::oop_print_on(oop obj, outputStream* st) {
2338 Klass::oop_print_on(obj, st);
2339
2340 if (as_klassOop() == SystemDictionary::String_klass()) {
2341 typeArrayOop value = java_lang_String::value(obj);
2342 juint offset = java_lang_String::offset(obj);
2343 juint length = java_lang_String::length(obj);
2344 if (value != NULL &&
2345 value->is_typeArray() &&
2346 offset <= (juint) value->length() &&
2347 offset + length <= (juint) value->length()) {
2348 st->print(BULLET"string: ");
2349 Handle h_obj(obj);
2350 java_lang_String::print(h_obj, st);
2351 st->cr();
2352 if (!WizardMode) return; // that is enough
2353 }
2354 }
2355
2356 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
2357 FieldPrinter print_field(st, obj);
2358 do_nonstatic_fields(&print_field);
2359
2360 if (as_klassOop() == SystemDictionary::Class_klass()) {
2361 st->print(BULLET"signature: ");
2362 java_lang_Class::print_signature(obj, st);
2363 st->cr();
2364 klassOop mirrored_klass = java_lang_Class::as_klassOop(obj);
2365 st->print(BULLET"fake entry for mirror: ");
2366 mirrored_klass->print_value_on(st);
2367 st->cr();
2368 st->print(BULLET"fake entry resolved_constructor: ");
2369 methodOop ctor = java_lang_Class::resolved_constructor(obj);
2370 ctor->print_value_on(st);
2371 klassOop array_klass = java_lang_Class::array_klass(obj);
2372 st->cr();
2373 st->print(BULLET"fake entry for array: ");
2374 array_klass->print_value_on(st);
2375 st->cr();
2376 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
2377 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
2378 klassOop real_klass = java_lang_Class::as_klassOop(obj);
2379 if (real_klass != NULL && real_klass->klass_part()->oop_is_instance()) {
2380 instanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
2381 }
2382 } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
2383 st->print(BULLET"signature: ");
2384 java_lang_invoke_MethodType::print_signature(obj, st);
2385 st->cr();
2386 }
2387 }
2388
2389 #endif //PRODUCT
2390
2391 void instanceKlass::oop_print_value_on(oop obj, outputStream* st) {
2392 st->print("a ");
2393 name()->print_value_on(st);
2394 obj->print_address_on(st);
2395 if (as_klassOop() == SystemDictionary::String_klass()
2396 && java_lang_String::value(obj) != NULL) {
2397 ResourceMark rm;
2398 int len = java_lang_String::length(obj);
2399 int plen = (len < 24 ? len : 12);
2400 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
2401 st->print(" = \"%s\"", str);
2402 if (len > plen)
2403 st->print("...[%d]", len);
2404 } else if (as_klassOop() == SystemDictionary::Class_klass()) {
2405 klassOop k = java_lang_Class::as_klassOop(obj);
2406 st->print(" = ");
2407 if (k != NULL) {
2408 k->print_value_on(st);
2409 } else {
2410 const char* tname = type2name(java_lang_Class::primitive_type(obj));
2411 st->print("%s", tname ? tname : "type?");
2412 }
2413 } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
2414 st->print(" = ");
2415 java_lang_invoke_MethodType::print_signature(obj, st);
2416 } else if (java_lang_boxing_object::is_instance(obj)) {
2417 st->print(" = ");
2418 java_lang_boxing_object::print(obj, st);
2419 }
2420 }
2421
2422 const char* instanceKlass::internal_name() const {
2423 return external_name();
2424 }
2425
2426 // Verification
2427
2428 class VerifyFieldClosure: public OopClosure {
2429 protected:
2430 template <class T> void do_oop_work(T* p) {
2431 guarantee(Universe::heap()->is_in_closed_subset(p), "should be in heap");
2432 oop obj = oopDesc::load_decode_heap_oop(p);
2433 if (!obj->is_oop_or_null()) {
2434 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
2435 Universe::print();
2436 guarantee(false, "boom");
2437 }
2438 }
2439 public:
2440 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
2441 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
2442 };
2443
2444 void instanceKlass::oop_verify_on(oop obj, outputStream* st) {
2445 Klass::oop_verify_on(obj, st);
2446 VerifyFieldClosure blk;
2447 oop_oop_iterate(obj, &blk);
2448 }
2449
2450 // JNIid class for jfieldIDs only
2451 // Note to reviewers:
2452 // These JNI functions are just moved over to column 1 and not changed
2453 // in the compressed oops workspace.
2454 JNIid::JNIid(klassOop holder, int offset, JNIid* next) {
2455 _holder = holder;
2456 _offset = offset;
2457 _next = next;
2458 debug_only(_is_static_field_id = false;)
2459 }
2460
2461
2462 JNIid* JNIid::find(int offset) {
2463 JNIid* current = this;
2464 while (current != NULL) {
2465 if (current->offset() == offset) return current;
2466 current = current->next();
2467 }
2468 return NULL;
2469 }
2470
2471 void JNIid::oops_do(OopClosure* f) {
2472 for (JNIid* cur = this; cur != NULL; cur = cur->next()) {
2473 f->do_oop(cur->holder_addr());
2474 }
2475 }
2476
2477 void JNIid::deallocate(JNIid* current) {
2478 while (current != NULL) {
2479 JNIid* next = current->next();
2480 delete current;
2481 current = next;
2482 }
2483 }
2484
2485
2486 void JNIid::verify(klassOop holder) {
2487 int first_field_offset = instanceMirrorKlass::offset_of_static_fields();
2488 int end_field_offset;
2489 end_field_offset = first_field_offset + (instanceKlass::cast(holder)->static_field_size() * wordSize);
2490
2491 JNIid* current = this;
2492 while (current != NULL) {
2493 guarantee(current->holder() == holder, "Invalid klass in JNIid");
2494 #ifdef ASSERT
2495 int o = current->offset();
2496 if (current->is_static_field_id()) {
2497 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
2498 }
2499 #endif
2500 current = current->next();
2501 }
2502 }
2503
2504
2505 #ifdef ASSERT
2506 void instanceKlass::set_init_state(ClassState state) {
2507 bool good_state = as_klassOop()->is_shared() ? (_init_state <= state)
2508 : (_init_state < state);
2509 assert(good_state || state == allocated, "illegal state transition");
2510 _init_state = (u1)state;
2511 }
2512 #endif
2513
2514
2515 // RedefineClasses() support for previous versions:
2516
2517 // Add an information node that contains weak references to the
2518 // interesting parts of the previous version of the_class.
2519 // This is also where we clean out any unused weak references.
2520 // Note that while we delete nodes from the _previous_versions
2521 // array, we never delete the array itself until the klass is
2522 // unloaded. The has_been_redefined() query depends on that fact.
2523 //
2524 void instanceKlass::add_previous_version(instanceKlassHandle ikh,
2525 BitMap* emcp_methods, int emcp_method_count) {
2526 assert(Thread::current()->is_VM_thread(),
2527 "only VMThread can add previous versions");
2528
2529 if (_previous_versions == NULL) {
2530 // This is the first previous version so make some space.
2531 // Start with 2 elements under the assumption that the class
2532 // won't be redefined much.
2533 _previous_versions = new (ResourceObj::C_HEAP, mtClass)
2534 GrowableArray<PreviousVersionNode *>(2, true);
2535 }
2536
2537 // RC_TRACE macro has an embedded ResourceMark
2538 RC_TRACE(0x00000100, ("adding previous version ref for %s @%d, EMCP_cnt=%d",
2539 ikh->external_name(), _previous_versions->length(), emcp_method_count));
2540 constantPoolHandle cp_h(ikh->constants());
2541 jobject cp_ref;
2542 if (cp_h->is_shared()) {
2543 // a shared ConstantPool requires a regular reference; a weak
2544 // reference would be collectible
2545 cp_ref = JNIHandles::make_global(cp_h);
2546 } else {
2547 cp_ref = JNIHandles::make_weak_global(cp_h);
2548 }
2549 PreviousVersionNode * pv_node = NULL;
2550 objArrayOop old_methods = ikh->methods();
2551
2552 if (emcp_method_count == 0) {
2553 // non-shared ConstantPool gets a weak reference
2554 pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), NULL);
2555 RC_TRACE(0x00000400,
2556 ("add: all methods are obsolete; flushing any EMCP weak refs"));
2557 } else {
2558 int local_count = 0;
2559 GrowableArray<jweak>* method_refs = new (ResourceObj::C_HEAP, mtClass)
2560 GrowableArray<jweak>(emcp_method_count, true);
2561 for (int i = 0; i < old_methods->length(); i++) {
2562 if (emcp_methods->at(i)) {
2563 // this old method is EMCP so save a weak ref
2564 methodOop old_method = (methodOop) old_methods->obj_at(i);
2565 methodHandle old_method_h(old_method);
2566 jweak method_ref = JNIHandles::make_weak_global(old_method_h);
2567 method_refs->append(method_ref);
2568 if (++local_count >= emcp_method_count) {
2569 // no more EMCP methods so bail out now
2570 break;
2571 }
2572 }
2573 }
2574 // non-shared ConstantPool gets a weak reference
2575 pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), method_refs);
2576 }
2577
2578 _previous_versions->append(pv_node);
2579
2580 // Using weak references allows the interesting parts of previous
2581 // classes to be GC'ed when they are no longer needed. Since the
2582 // caller is the VMThread and we are at a safepoint, this is a good
2583 // time to clear out unused weak references.
2584
2585 RC_TRACE(0x00000400, ("add: previous version length=%d",
2586 _previous_versions->length()));
2587
2588 // skip the last entry since we just added it
2589 for (int i = _previous_versions->length() - 2; i >= 0; i--) {
2590 // check the previous versions array for a GC'ed weak refs
2591 pv_node = _previous_versions->at(i);
2592 cp_ref = pv_node->prev_constant_pool();
2593 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
2594 if (cp_ref == NULL) {
2595 delete pv_node;
2596 _previous_versions->remove_at(i);
2597 // Since we are traversing the array backwards, we don't have to
2598 // do anything special with the index.
2599 continue; // robustness
2600 }
2601
2602 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2603 if (cp == NULL) {
2604 // this entry has been GC'ed so remove it
2605 delete pv_node;
2606 _previous_versions->remove_at(i);
2607 // Since we are traversing the array backwards, we don't have to
2608 // do anything special with the index.
2609 continue;
2610 } else {
2611 RC_TRACE(0x00000400, ("add: previous version @%d is alive", i));
2612 }
2613
2614 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2615 if (method_refs != NULL) {
2616 RC_TRACE(0x00000400, ("add: previous methods length=%d",
2617 method_refs->length()));
2618 for (int j = method_refs->length() - 1; j >= 0; j--) {
2619 jweak method_ref = method_refs->at(j);
2620 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
2621 if (method_ref == NULL) {
2622 method_refs->remove_at(j);
2623 // Since we are traversing the array backwards, we don't have to
2624 // do anything special with the index.
2625 continue; // robustness
2626 }
2627
2628 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2629 if (method == NULL || emcp_method_count == 0) {
2630 // This method entry has been GC'ed or the current
2631 // RedefineClasses() call has made all methods obsolete
2632 // so remove it.
2633 JNIHandles::destroy_weak_global(method_ref);
2634 method_refs->remove_at(j);
2635 } else {
2636 // RC_TRACE macro has an embedded ResourceMark
2637 RC_TRACE(0x00000400,
2638 ("add: %s(%s): previous method @%d in version @%d is alive",
2639 method->name()->as_C_string(), method->signature()->as_C_string(),
2640 j, i));
2641 }
2642 }
2643 }
2644 }
2645
2646 int obsolete_method_count = old_methods->length() - emcp_method_count;
2647
2648 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
2649 _previous_versions->length() > 1) {
2650 // We have a mix of obsolete and EMCP methods. If there is more
2651 // than the previous version that we just added, then we have to
2652 // clear out any matching EMCP method entries the hard way.
2653 int local_count = 0;
2654 for (int i = 0; i < old_methods->length(); i++) {
2655 if (!emcp_methods->at(i)) {
2656 // only obsolete methods are interesting
2657 methodOop old_method = (methodOop) old_methods->obj_at(i);
2658 Symbol* m_name = old_method->name();
2659 Symbol* m_signature = old_method->signature();
2660
2661 // skip the last entry since we just added it
2662 for (int j = _previous_versions->length() - 2; j >= 0; j--) {
2663 // check the previous versions array for a GC'ed weak refs
2664 pv_node = _previous_versions->at(j);
2665 cp_ref = pv_node->prev_constant_pool();
2666 assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
2667 if (cp_ref == NULL) {
2668 delete pv_node;
2669 _previous_versions->remove_at(j);
2670 // Since we are traversing the array backwards, we don't have to
2671 // do anything special with the index.
2672 continue; // robustness
2673 }
2674
2675 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2676 if (cp == NULL) {
2677 // this entry has been GC'ed so remove it
2678 delete pv_node;
2679 _previous_versions->remove_at(j);
2680 // Since we are traversing the array backwards, we don't have to
2681 // do anything special with the index.
2682 continue;
2683 }
2684
2685 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2686 if (method_refs == NULL) {
2687 // We have run into a PreviousVersion generation where
2688 // all methods were made obsolete during that generation's
2689 // RedefineClasses() operation. At the time of that
2690 // operation, all EMCP methods were flushed so we don't
2691 // have to go back any further.
2692 //
2693 // A NULL method_refs is different than an empty method_refs.
2694 // We cannot infer any optimizations about older generations
2695 // from an empty method_refs for the current generation.
2696 break;
2697 }
2698
2699 for (int k = method_refs->length() - 1; k >= 0; k--) {
2700 jweak method_ref = method_refs->at(k);
2701 assert(method_ref != NULL,
2702 "weak method ref was unexpectedly cleared");
2703 if (method_ref == NULL) {
2704 method_refs->remove_at(k);
2705 // Since we are traversing the array backwards, we don't
2706 // have to do anything special with the index.
2707 continue; // robustness
2708 }
2709
2710 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2711 if (method == NULL) {
2712 // this method entry has been GC'ed so skip it
2713 JNIHandles::destroy_weak_global(method_ref);
2714 method_refs->remove_at(k);
2715 continue;
2716 }
2717
2718 if (method->name() == m_name &&
2719 method->signature() == m_signature) {
2720 // The current RedefineClasses() call has made all EMCP
2721 // versions of this method obsolete so mark it as obsolete
2722 // and remove the weak ref.
2723 RC_TRACE(0x00000400,
2724 ("add: %s(%s): flush obsolete method @%d in version @%d",
2725 m_name->as_C_string(), m_signature->as_C_string(), k, j));
2726
2727 method->set_is_obsolete();
2728 JNIHandles::destroy_weak_global(method_ref);
2729 method_refs->remove_at(k);
2730 break;
2731 }
2732 }
2733
2734 // The previous loop may not find a matching EMCP method, but
2735 // that doesn't mean that we can optimize and not go any
2736 // further back in the PreviousVersion generations. The EMCP
2737 // method for this generation could have already been GC'ed,
2738 // but there still may be an older EMCP method that has not
2739 // been GC'ed.
2740 }
2741
2742 if (++local_count >= obsolete_method_count) {
2743 // no more obsolete methods so bail out now
2744 break;
2745 }
2746 }
2747 }
2748 }
2749 } // end add_previous_version()
2750
2751
2752 // Determine if instanceKlass has a previous version.
2753 bool instanceKlass::has_previous_version() const {
2754 if (_previous_versions == NULL) {
2755 // no previous versions array so answer is easy
2756 return false;
2757 }
2758
2759 for (int i = _previous_versions->length() - 1; i >= 0; i--) {
2760 // Check the previous versions array for an info node that hasn't
2761 // been GC'ed
2762 PreviousVersionNode * pv_node = _previous_versions->at(i);
2763
2764 jobject cp_ref = pv_node->prev_constant_pool();
2765 assert(cp_ref != NULL, "cp reference was unexpectedly cleared");
2766 if (cp_ref == NULL) {
2767 continue; // robustness
2768 }
2769
2770 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2771 if (cp != NULL) {
2772 // we have at least one previous version
2773 return true;
2774 }
2775
2776 // We don't have to check the method refs. If the constant pool has
2777 // been GC'ed then so have the methods.
2778 }
2779
2780 // all of the underlying nodes' info has been GC'ed
2781 return false;
2782 } // end has_previous_version()
2783
2784 methodOop instanceKlass::method_with_idnum(int idnum) {
2785 methodOop m = NULL;
2786 if (idnum < methods()->length()) {
2787 m = (methodOop) methods()->obj_at(idnum);
2788 }
2789 if (m == NULL || m->method_idnum() != idnum) {
2790 for (int index = 0; index < methods()->length(); ++index) {
2791 m = (methodOop) methods()->obj_at(index);
2792 if (m->method_idnum() == idnum) {
2793 return m;
2794 }
2795 }
2796 }
2797 return m;
2798 }
2799
2800
2801 // Set the annotation at 'idnum' to 'anno'.
2802 // We don't want to create or extend the array if 'anno' is NULL, since that is the
2803 // default value. However, if the array exists and is long enough, we must set NULL values.
2804 void instanceKlass::set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p) {
2805 objArrayOop md = *md_p;
2806 if (md != NULL && md->length() > idnum) {
2807 md->obj_at_put(idnum, anno);
2808 } else if (anno != NULL) {
2809 // create the array
2810 int length = MAX2(idnum+1, (int)_idnum_allocated_count);
2811 md = oopFactory::new_system_objArray(length, Thread::current());
2812 if (*md_p != NULL) {
2813 // copy the existing entries
2814 for (int index = 0; index < (*md_p)->length(); index++) {
2815 md->obj_at_put(index, (*md_p)->obj_at(index));
2816 }
2817 }
2818 set_annotations(md, md_p);
2819 md->obj_at_put(idnum, anno);
2820 } // if no array and idnum isn't included there is nothing to do
2821 }
2822
2823 // Construct a PreviousVersionNode entry for the array hung off
2824 // the instanceKlass.
2825 PreviousVersionNode::PreviousVersionNode(jobject prev_constant_pool,
2826 bool prev_cp_is_weak, GrowableArray<jweak>* prev_EMCP_methods) {
2827
2828 _prev_constant_pool = prev_constant_pool;
2829 _prev_cp_is_weak = prev_cp_is_weak;
2830 _prev_EMCP_methods = prev_EMCP_methods;
2831 }
2832
2833
2834 // Destroy a PreviousVersionNode
2835 PreviousVersionNode::~PreviousVersionNode() {
2836 if (_prev_constant_pool != NULL) {
2837 if (_prev_cp_is_weak) {
2838 JNIHandles::destroy_weak_global(_prev_constant_pool);
2839 } else {
2840 JNIHandles::destroy_global(_prev_constant_pool);
2841 }
2842 }
2843
2844 if (_prev_EMCP_methods != NULL) {
2845 for (int i = _prev_EMCP_methods->length() - 1; i >= 0; i--) {
2846 jweak method_ref = _prev_EMCP_methods->at(i);
2847 if (method_ref != NULL) {
2848 JNIHandles::destroy_weak_global(method_ref);
2849 }
2850 }
2851 delete _prev_EMCP_methods;
2852 }
2853 }
2854
2855
2856 // Construct a PreviousVersionInfo entry
2857 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
2858 _prev_constant_pool_handle = constantPoolHandle(); // NULL handle
2859 _prev_EMCP_method_handles = NULL;
2860
2861 jobject cp_ref = pv_node->prev_constant_pool();
2862 assert(cp_ref != NULL, "constant pool ref was unexpectedly cleared");
2863 if (cp_ref == NULL) {
2864 return; // robustness
2865 }
2866
2867 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2868 if (cp == NULL) {
2869 // Weak reference has been GC'ed. Since the constant pool has been
2870 // GC'ed, the methods have also been GC'ed.
2871 return;
2872 }
2873
2874 // make the constantPoolOop safe to return
2875 _prev_constant_pool_handle = constantPoolHandle(cp);
2876
2877 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2878 if (method_refs == NULL) {
2879 // the instanceKlass did not have any EMCP methods
2880 return;
2881 }
2882
2883 _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
2884
2885 int n_methods = method_refs->length();
2886 for (int i = 0; i < n_methods; i++) {
2887 jweak method_ref = method_refs->at(i);
2888 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
2889 if (method_ref == NULL) {
2890 continue; // robustness
2891 }
2892
2893 methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2894 if (method == NULL) {
2895 // this entry has been GC'ed so skip it
2896 continue;
2897 }
2898
2899 // make the methodOop safe to return
2900 _prev_EMCP_method_handles->append(methodHandle(method));
2901 }
2902 }
2903
2904
2905 // Destroy a PreviousVersionInfo
2906 PreviousVersionInfo::~PreviousVersionInfo() {
2907 // Since _prev_EMCP_method_handles is not C-heap allocated, we
2908 // don't have to delete it.
2909 }
2910
2911
2912 // Construct a helper for walking the previous versions array
2913 PreviousVersionWalker::PreviousVersionWalker(instanceKlass *ik) {
2914 _previous_versions = ik->previous_versions();
2915 _current_index = 0;
2916 // _hm needs no initialization
2917 _current_p = NULL;
2918 }
2919
2920
2921 // Destroy a PreviousVersionWalker
2922 PreviousVersionWalker::~PreviousVersionWalker() {
2923 // Delete the current info just in case the caller didn't walk to
2924 // the end of the previous versions list. No harm if _current_p is
2925 // already NULL.
2926 delete _current_p;
2927
2928 // When _hm is destroyed, all the Handles returned in
2929 // PreviousVersionInfo objects will be destroyed.
2930 // Also, after this destructor is finished it will be
2931 // safe to delete the GrowableArray allocated in the
2932 // PreviousVersionInfo objects.
2933 }
2934
2935
2936 // Return the interesting information for the next previous version
2937 // of the klass. Returns NULL if there are no more previous versions.
2938 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
2939 if (_previous_versions == NULL) {
2940 // no previous versions so nothing to return
2941 return NULL;
2942 }
2943
2944 delete _current_p; // cleanup the previous info for the caller
2945 _current_p = NULL; // reset to NULL so we don't delete same object twice
2946
2947 int length = _previous_versions->length();
2948
2949 while (_current_index < length) {
2950 PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
2951 PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP, mtClass)
2952 PreviousVersionInfo(pv_node);
2953
2954 constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
2955 if (cp_h.is_null()) {
2956 delete pv_info;
2957
2958 // The underlying node's info has been GC'ed so try the next one.
2959 // We don't have to check the methods. If the constant pool has
2960 // GC'ed then so have the methods.
2961 continue;
2962 }
2963
2964 // Found a node with non GC'ed info so return it. The caller will
2965 // need to delete pv_info when they are done with it.
2966 _current_p = pv_info;
2967 return pv_info;
2968 }
2969
2970 // all of the underlying nodes' info has been GC'ed
2971 return NULL;
2972 } // end next_previous_version()