1 /* 2 * Copyright (c) 1997, 2010, 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/instanceKlass.hpp" 40 #include "oops/instanceOop.hpp" 41 #include "oops/methodOop.hpp" 42 #include "oops/objArrayKlassKlass.hpp" 43 #include "oops/oop.inline.hpp" 44 #include "oops/symbolOop.hpp" 45 #include "prims/jvmtiExport.hpp" 46 #include "prims/jvmtiRedefineClassesTrace.hpp" 47 #include "runtime/fieldDescriptor.hpp" 48 #include "runtime/handles.inline.hpp" 49 #include "runtime/javaCalls.hpp" 50 #include "runtime/mutexLocker.hpp" 51 #include "services/threadService.hpp" 52 #include "utilities/dtrace.hpp" 53 #ifdef TARGET_OS_FAMILY_linux 54 # include "thread_linux.inline.hpp" 55 #endif 56 #ifdef TARGET_OS_FAMILY_solaris 57 # include "thread_solaris.inline.hpp" 58 #endif 59 #ifdef TARGET_OS_FAMILY_windows 60 # include "thread_windows.inline.hpp" 61 #endif 62 #ifndef SERIALGC 63 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" 64 #include "gc_implementation/g1/g1OopClosures.inline.hpp" 65 #include "gc_implementation/g1/g1RemSet.inline.hpp" 66 #include "gc_implementation/g1/heapRegionSeq.inline.hpp" 67 #include "gc_implementation/parNew/parOopClosures.inline.hpp" 68 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp" 69 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp" 70 #include "oops/oop.pcgc.inline.hpp" 71 #endif 72 #ifdef COMPILER1 73 #include "c1/c1_Compiler.hpp" 74 #endif 75 76 #ifdef DTRACE_ENABLED 77 78 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required, 79 char*, intptr_t, oop, intptr_t); 80 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive, 81 char*, intptr_t, oop, intptr_t, int); 82 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent, 83 char*, intptr_t, oop, intptr_t, int); 84 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous, 85 char*, intptr_t, oop, intptr_t, int); 86 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed, 87 char*, intptr_t, oop, intptr_t, int); 88 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit, 89 char*, intptr_t, oop, intptr_t, int); 90 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error, 91 char*, intptr_t, oop, intptr_t, int); 92 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end, 93 char*, intptr_t, oop, intptr_t, int); 94 95 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \ 96 { \ 97 char* data = NULL; \ 98 int len = 0; \ 99 symbolOop name = (clss)->name(); \ 100 if (name != NULL) { \ 101 data = (char*)name->bytes(); \ 102 len = name->utf8_length(); \ 103 } \ 104 HS_DTRACE_PROBE4(hotspot, class__initialization__##type, \ 105 data, len, (clss)->class_loader(), thread_type); \ 106 } 107 108 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \ 109 { \ 110 char* data = NULL; \ 111 int len = 0; \ 112 symbolOop name = (clss)->name(); \ 113 if (name != NULL) { \ 114 data = (char*)name->bytes(); \ 115 len = name->utf8_length(); \ 116 } \ 117 HS_DTRACE_PROBE5(hotspot, class__initialization__##type, \ 118 data, len, (clss)->class_loader(), thread_type, wait); \ 119 } 120 121 #else // ndef DTRACE_ENABLED 122 123 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) 124 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) 125 126 #endif // ndef DTRACE_ENABLED 127 128 bool instanceKlass::should_be_initialized() const { 129 return !is_initialized(); 130 } 131 132 klassVtable* instanceKlass::vtable() const { 133 return new klassVtable(as_klassOop(), start_of_vtable(), vtable_length() / vtableEntry::size()); 134 } 135 136 klassItable* instanceKlass::itable() const { 137 return new klassItable(as_klassOop()); 138 } 139 140 void instanceKlass::eager_initialize(Thread *thread) { 141 if (!EagerInitialization) return; 142 143 if (this->is_not_initialized()) { 144 // abort if the the class has a class initializer 145 if (this->class_initializer() != NULL) return; 146 147 // abort if it is java.lang.Object (initialization is handled in genesis) 148 klassOop super = this->super(); 149 if (super == NULL) return; 150 151 // abort if the super class should be initialized 152 if (!instanceKlass::cast(super)->is_initialized()) return; 153 154 // call body to expose the this pointer 155 instanceKlassHandle this_oop(thread, this->as_klassOop()); 156 eager_initialize_impl(this_oop); 157 } 158 } 159 160 161 void instanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) { 162 EXCEPTION_MARK; 163 ObjectLocker ol(this_oop, THREAD); 164 165 // abort if someone beat us to the initialization 166 if (!this_oop->is_not_initialized()) return; // note: not equivalent to is_initialized() 167 168 ClassState old_state = this_oop->_init_state; 169 link_class_impl(this_oop, true, THREAD); 170 if (HAS_PENDING_EXCEPTION) { 171 CLEAR_PENDING_EXCEPTION; 172 // Abort if linking the class throws an exception. 173 174 // Use a test to avoid redundantly resetting the state if there's 175 // no change. Set_init_state() asserts that state changes make 176 // progress, whereas here we might just be spinning in place. 177 if( old_state != this_oop->_init_state ) 178 this_oop->set_init_state (old_state); 179 } else { 180 // linking successfull, mark class as initialized 181 this_oop->set_init_state (fully_initialized); 182 // trace 183 if (TraceClassInitialization) { 184 ResourceMark rm(THREAD); 185 tty->print_cr("[Initialized %s without side effects]", this_oop->external_name()); 186 } 187 } 188 } 189 190 191 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization 192 // process. The step comments refers to the procedure described in that section. 193 // Note: implementation moved to static method to expose the this pointer. 194 void instanceKlass::initialize(TRAPS) { 195 if (this->should_be_initialized()) { 196 HandleMark hm(THREAD); 197 instanceKlassHandle this_oop(THREAD, this->as_klassOop()); 198 initialize_impl(this_oop, CHECK); 199 // Note: at this point the class may be initialized 200 // OR it may be in the state of being initialized 201 // in case of recursive initialization! 202 } else { 203 assert(is_initialized(), "sanity check"); 204 } 205 } 206 207 208 bool instanceKlass::verify_code( 209 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) { 210 // 1) Verify the bytecodes 211 Verifier::Mode mode = 212 throw_verifyerror ? Verifier::ThrowException : Verifier::NoException; 213 return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false); 214 } 215 216 217 // Used exclusively by the shared spaces dump mechanism to prevent 218 // classes mapped into the shared regions in new VMs from appearing linked. 219 220 void instanceKlass::unlink_class() { 221 assert(is_linked(), "must be linked"); 222 _init_state = loaded; 223 } 224 225 void instanceKlass::link_class(TRAPS) { 226 assert(is_loaded(), "must be loaded"); 227 if (!is_linked()) { 228 instanceKlassHandle this_oop(THREAD, this->as_klassOop()); 229 link_class_impl(this_oop, true, CHECK); 230 } 231 } 232 233 // Called to verify that a class can link during initialization, without 234 // throwing a VerifyError. 235 bool instanceKlass::link_class_or_fail(TRAPS) { 236 assert(is_loaded(), "must be loaded"); 237 if (!is_linked()) { 238 instanceKlassHandle this_oop(THREAD, this->as_klassOop()); 239 link_class_impl(this_oop, false, CHECK_false); 240 } 241 return is_linked(); 242 } 243 244 bool instanceKlass::link_class_impl( 245 instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) { 246 // check for error state 247 if (this_oop->is_in_error_state()) { 248 ResourceMark rm(THREAD); 249 THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(), 250 this_oop->external_name(), false); 251 } 252 // return if already verified 253 if (this_oop->is_linked()) { 254 return true; 255 } 256 257 // Timing 258 // timer handles recursion 259 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl"); 260 JavaThread* jt = (JavaThread*)THREAD; 261 262 // link super class before linking this class 263 instanceKlassHandle super(THREAD, this_oop->super()); 264 if (super.not_null()) { 265 if (super->is_interface()) { // check if super class is an interface 266 ResourceMark rm(THREAD); 267 Exceptions::fthrow( 268 THREAD_AND_LOCATION, 269 vmSymbolHandles::java_lang_IncompatibleClassChangeError(), 270 "class %s has interface %s as super class", 271 this_oop->external_name(), 272 super->external_name() 273 ); 274 return false; 275 } 276 277 link_class_impl(super, throw_verifyerror, CHECK_false); 278 } 279 280 // link all interfaces implemented by this class before linking this class 281 objArrayHandle interfaces (THREAD, this_oop->local_interfaces()); 282 int num_interfaces = interfaces->length(); 283 for (int index = 0; index < num_interfaces; index++) { 284 HandleMark hm(THREAD); 285 instanceKlassHandle ih(THREAD, klassOop(interfaces->obj_at(index))); 286 link_class_impl(ih, throw_verifyerror, CHECK_false); 287 } 288 289 // in case the class is linked in the process of linking its superclasses 290 if (this_oop->is_linked()) { 291 return true; 292 } 293 294 // trace only the link time for this klass that includes 295 // the verification time 296 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(), 297 ClassLoader::perf_class_link_selftime(), 298 ClassLoader::perf_classes_linked(), 299 jt->get_thread_stat()->perf_recursion_counts_addr(), 300 jt->get_thread_stat()->perf_timers_addr(), 301 PerfClassTraceTime::CLASS_LINK); 302 303 // verification & rewriting 304 { 305 ObjectLocker ol(this_oop, THREAD); 306 // rewritten will have been set if loader constraint error found 307 // on an earlier link attempt 308 // don't verify or rewrite if already rewritten 309 if (!this_oop->is_linked()) { 310 if (!this_oop->is_rewritten()) { 311 { 312 // Timer includes any side effects of class verification (resolution, 313 // etc), but not recursive entry into verify_code(). 314 PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(), 315 ClassLoader::perf_class_verify_selftime(), 316 ClassLoader::perf_classes_verified(), 317 jt->get_thread_stat()->perf_recursion_counts_addr(), 318 jt->get_thread_stat()->perf_timers_addr(), 319 PerfClassTraceTime::CLASS_VERIFY); 320 bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD); 321 if (!verify_ok) { 322 return false; 323 } 324 } 325 326 // Just in case a side-effect of verify linked this class already 327 // (which can sometimes happen since the verifier loads classes 328 // using custom class loaders, which are free to initialize things) 329 if (this_oop->is_linked()) { 330 return true; 331 } 332 333 // also sets rewritten 334 this_oop->rewrite_class(CHECK_false); 335 } 336 337 // Initialize the vtable and interface table after 338 // methods have been rewritten since rewrite may 339 // fabricate new methodOops. 340 // also does loader constraint checking 341 if (!this_oop()->is_shared()) { 342 ResourceMark rm(THREAD); 343 this_oop->vtable()->initialize_vtable(true, CHECK_false); 344 this_oop->itable()->initialize_itable(true, CHECK_false); 345 } 346 #ifdef ASSERT 347 else { 348 ResourceMark rm(THREAD); 349 this_oop->vtable()->verify(tty, true); 350 // In case itable verification is ever added. 351 // this_oop->itable()->verify(tty, true); 352 } 353 #endif 354 this_oop->set_init_state(linked); 355 if (JvmtiExport::should_post_class_prepare()) { 356 Thread *thread = THREAD; 357 assert(thread->is_Java_thread(), "thread->is_Java_thread()"); 358 JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop()); 359 } 360 } 361 } 362 return true; 363 } 364 365 366 // Rewrite the byte codes of all of the methods of a class. 367 // Three cases: 368 // During the link of a newly loaded class. 369 // During the preloading of classes to be written to the shared spaces. 370 // - Rewrite the methods and update the method entry points. 371 // 372 // During the link of a class in the shared spaces. 373 // - The methods were already rewritten, update the metho entry points. 374 // 375 // The rewriter must be called exactly once. Rewriting must happen after 376 // verification but before the first method of the class is executed. 377 378 void instanceKlass::rewrite_class(TRAPS) { 379 assert(is_loaded(), "must be loaded"); 380 instanceKlassHandle this_oop(THREAD, this->as_klassOop()); 381 if (this_oop->is_rewritten()) { 382 assert(this_oop()->is_shared(), "rewriting an unshared class?"); 383 return; 384 } 385 Rewriter::rewrite(this_oop, CHECK); // No exception can happen here 386 this_oop->set_rewritten(); 387 } 388 389 390 void instanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) { 391 // Make sure klass is linked (verified) before initialization 392 // A class could already be verified, since it has been reflected upon. 393 this_oop->link_class(CHECK); 394 395 DTRACE_CLASSINIT_PROBE(required, instanceKlass::cast(this_oop()), -1); 396 397 bool wait = false; 398 399 // refer to the JVM book page 47 for description of steps 400 // Step 1 401 { ObjectLocker ol(this_oop, THREAD); 402 403 Thread *self = THREAD; // it's passed the current thread 404 405 // Step 2 406 // If we were to use wait() instead of waitInterruptibly() then 407 // we might end up throwing IE from link/symbol resolution sites 408 // that aren't expected to throw. This would wreak havoc. See 6320309. 409 while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) { 410 wait = true; 411 ol.waitUninterruptibly(CHECK); 412 } 413 414 // Step 3 415 if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) { 416 DTRACE_CLASSINIT_PROBE_WAIT(recursive, instanceKlass::cast(this_oop()), -1,wait); 417 return; 418 } 419 420 // Step 4 421 if (this_oop->is_initialized()) { 422 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, instanceKlass::cast(this_oop()), -1,wait); 423 return; 424 } 425 426 // Step 5 427 if (this_oop->is_in_error_state()) { 428 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, instanceKlass::cast(this_oop()), -1,wait); 429 ResourceMark rm(THREAD); 430 const char* desc = "Could not initialize class "; 431 const char* className = this_oop->external_name(); 432 size_t msglen = strlen(desc) + strlen(className) + 1; 433 char* message = NEW_RESOURCE_ARRAY(char, msglen); 434 if (NULL == message) { 435 // Out of memory: can't create detailed error message 436 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className); 437 } else { 438 jio_snprintf(message, msglen, "%s%s", desc, className); 439 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message); 440 } 441 } 442 443 // Step 6 444 this_oop->set_init_state(being_initialized); 445 this_oop->set_init_thread(self); 446 } 447 448 // Step 7 449 klassOop super_klass = this_oop->super(); 450 if (super_klass != NULL && !this_oop->is_interface() && Klass::cast(super_klass)->should_be_initialized()) { 451 Klass::cast(super_klass)->initialize(THREAD); 452 453 if (HAS_PENDING_EXCEPTION) { 454 Handle e(THREAD, PENDING_EXCEPTION); 455 CLEAR_PENDING_EXCEPTION; 456 { 457 EXCEPTION_MARK; 458 this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads 459 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, superclass initialization error is thrown below 460 } 461 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, instanceKlass::cast(this_oop()), -1,wait); 462 THROW_OOP(e()); 463 } 464 } 465 466 // Step 8 467 { 468 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl"); 469 JavaThread* jt = (JavaThread*)THREAD; 470 DTRACE_CLASSINIT_PROBE_WAIT(clinit, instanceKlass::cast(this_oop()), -1,wait); 471 // Timer includes any side effects of class initialization (resolution, 472 // etc), but not recursive entry into call_class_initializer(). 473 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(), 474 ClassLoader::perf_class_init_selftime(), 475 ClassLoader::perf_classes_inited(), 476 jt->get_thread_stat()->perf_recursion_counts_addr(), 477 jt->get_thread_stat()->perf_timers_addr(), 478 PerfClassTraceTime::CLASS_CLINIT); 479 this_oop->call_class_initializer(THREAD); 480 } 481 482 // Step 9 483 if (!HAS_PENDING_EXCEPTION) { 484 this_oop->set_initialization_state_and_notify(fully_initialized, CHECK); 485 { ResourceMark rm(THREAD); 486 debug_only(this_oop->vtable()->verify(tty, true);) 487 } 488 } 489 else { 490 // Step 10 and 11 491 Handle e(THREAD, PENDING_EXCEPTION); 492 CLEAR_PENDING_EXCEPTION; 493 { 494 EXCEPTION_MARK; 495 this_oop->set_initialization_state_and_notify(initialization_error, THREAD); 496 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below 497 } 498 DTRACE_CLASSINIT_PROBE_WAIT(error, instanceKlass::cast(this_oop()), -1,wait); 499 if (e->is_a(SystemDictionary::Error_klass())) { 500 THROW_OOP(e()); 501 } else { 502 JavaCallArguments args(e); 503 THROW_ARG(vmSymbolHandles::java_lang_ExceptionInInitializerError(), 504 vmSymbolHandles::throwable_void_signature(), 505 &args); 506 } 507 } 508 DTRACE_CLASSINIT_PROBE_WAIT(end, instanceKlass::cast(this_oop()), -1,wait); 509 } 510 511 512 // Note: implementation moved to static method to expose the this pointer. 513 void instanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) { 514 instanceKlassHandle kh(THREAD, this->as_klassOop()); 515 set_initialization_state_and_notify_impl(kh, state, CHECK); 516 } 517 518 void instanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) { 519 ObjectLocker ol(this_oop, THREAD); 520 this_oop->set_init_state(state); 521 ol.notify_all(CHECK); 522 } 523 524 void instanceKlass::add_implementor(klassOop k) { 525 assert(Compile_lock->owned_by_self(), ""); 526 // Filter out my subinterfaces. 527 // (Note: Interfaces are never on the subklass list.) 528 if (instanceKlass::cast(k)->is_interface()) return; 529 530 // Filter out subclasses whose supers already implement me. 531 // (Note: CHA must walk subclasses of direct implementors 532 // in order to locate indirect implementors.) 533 klassOop sk = instanceKlass::cast(k)->super(); 534 if (sk != NULL && instanceKlass::cast(sk)->implements_interface(as_klassOop())) 535 // We only need to check one immediate superclass, since the 536 // implements_interface query looks at transitive_interfaces. 537 // Any supers of the super have the same (or fewer) transitive_interfaces. 538 return; 539 540 // Update number of implementors 541 int i = _nof_implementors++; 542 543 // Record this implementor, if there are not too many already 544 if (i < implementors_limit) { 545 assert(_implementors[i] == NULL, "should be exactly one implementor"); 546 oop_store_without_check((oop*)&_implementors[i], k); 547 } else if (i == implementors_limit) { 548 // clear out the list on first overflow 549 for (int i2 = 0; i2 < implementors_limit; i2++) 550 oop_store_without_check((oop*)&_implementors[i2], NULL); 551 } 552 553 // The implementor also implements the transitive_interfaces 554 for (int index = 0; index < local_interfaces()->length(); index++) { 555 instanceKlass::cast(klassOop(local_interfaces()->obj_at(index)))->add_implementor(k); 556 } 557 } 558 559 void instanceKlass::init_implementor() { 560 for (int i = 0; i < implementors_limit; i++) 561 oop_store_without_check((oop*)&_implementors[i], NULL); 562 _nof_implementors = 0; 563 } 564 565 566 void instanceKlass::process_interfaces(Thread *thread) { 567 // link this class into the implementors list of every interface it implements 568 KlassHandle this_as_oop (thread, this->as_klassOop()); 569 for (int i = local_interfaces()->length() - 1; i >= 0; i--) { 570 assert(local_interfaces()->obj_at(i)->is_klass(), "must be a klass"); 571 instanceKlass* interf = instanceKlass::cast(klassOop(local_interfaces()->obj_at(i))); 572 assert(interf->is_interface(), "expected interface"); 573 interf->add_implementor(this_as_oop()); 574 } 575 } 576 577 bool instanceKlass::can_be_primary_super_slow() const { 578 if (is_interface()) 579 return false; 580 else 581 return Klass::can_be_primary_super_slow(); 582 } 583 584 objArrayOop instanceKlass::compute_secondary_supers(int num_extra_slots, TRAPS) { 585 // The secondaries are the implemented interfaces. 586 instanceKlass* ik = instanceKlass::cast(as_klassOop()); 587 objArrayHandle interfaces (THREAD, ik->transitive_interfaces()); 588 int num_secondaries = num_extra_slots + interfaces->length(); 589 if (num_secondaries == 0) { 590 return Universe::the_empty_system_obj_array(); 591 } else if (num_extra_slots == 0) { 592 return interfaces(); 593 } else { 594 // a mix of both 595 objArrayOop secondaries = oopFactory::new_system_objArray(num_secondaries, CHECK_NULL); 596 for (int i = 0; i < interfaces->length(); i++) { 597 secondaries->obj_at_put(num_extra_slots+i, interfaces->obj_at(i)); 598 } 599 return secondaries; 600 } 601 } 602 603 bool instanceKlass::compute_is_subtype_of(klassOop k) { 604 if (Klass::cast(k)->is_interface()) { 605 return implements_interface(k); 606 } else { 607 return Klass::compute_is_subtype_of(k); 608 } 609 } 610 611 bool instanceKlass::implements_interface(klassOop k) const { 612 if (as_klassOop() == k) return true; 613 assert(Klass::cast(k)->is_interface(), "should be an interface class"); 614 for (int i = 0; i < transitive_interfaces()->length(); i++) { 615 if (transitive_interfaces()->obj_at(i) == k) { 616 return true; 617 } 618 } 619 return false; 620 } 621 622 objArrayOop instanceKlass::allocate_objArray(int n, int length, TRAPS) { 623 if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 624 if (length > arrayOopDesc::max_array_length(T_OBJECT)) { 625 report_java_out_of_memory("Requested array size exceeds VM limit"); 626 THROW_OOP_0(Universe::out_of_memory_error_array_size()); 627 } 628 int size = objArrayOopDesc::object_size(length); 629 klassOop ak = array_klass(n, CHECK_NULL); 630 KlassHandle h_ak (THREAD, ak); 631 objArrayOop o = 632 (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL); 633 return o; 634 } 635 636 instanceOop instanceKlass::register_finalizer(instanceOop i, TRAPS) { 637 if (TraceFinalizerRegistration) { 638 tty->print("Registered "); 639 i->print_value_on(tty); 640 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i); 641 } 642 instanceHandle h_i(THREAD, i); 643 // Pass the handle as argument, JavaCalls::call expects oop as jobjects 644 JavaValue result(T_VOID); 645 JavaCallArguments args(h_i); 646 methodHandle mh (THREAD, Universe::finalizer_register_method()); 647 JavaCalls::call(&result, mh, &args, CHECK_NULL); 648 return h_i(); 649 } 650 651 instanceOop instanceKlass::allocate_instance(TRAPS) { 652 bool has_finalizer_flag = has_finalizer(); // Query before possible GC 653 int size = size_helper(); // Query before forming handle. 654 655 KlassHandle h_k(THREAD, as_klassOop()); 656 657 instanceOop i; 658 659 i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL); 660 if (has_finalizer_flag && !RegisterFinalizersAtInit) { 661 i = register_finalizer(i, CHECK_NULL); 662 } 663 return i; 664 } 665 666 instanceOop instanceKlass::allocate_permanent_instance(TRAPS) { 667 // Finalizer registration occurs in the Object.<init> constructor 668 // and constructors normally aren't run when allocating perm 669 // instances so simply disallow finalizable perm objects. This can 670 // be relaxed if a need for it is found. 671 assert(!has_finalizer(), "perm objects not allowed to have finalizers"); 672 int size = size_helper(); // Query before forming handle. 673 KlassHandle h_k(THREAD, as_klassOop()); 674 instanceOop i = (instanceOop) 675 CollectedHeap::permanent_obj_allocate(h_k, size, CHECK_NULL); 676 return i; 677 } 678 679 void instanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) { 680 if (is_interface() || is_abstract()) { 681 ResourceMark rm(THREAD); 682 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError() 683 : vmSymbols::java_lang_InstantiationException(), external_name()); 684 } 685 if (as_klassOop() == SystemDictionary::Class_klass()) { 686 ResourceMark rm(THREAD); 687 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError() 688 : vmSymbols::java_lang_IllegalAccessException(), external_name()); 689 } 690 } 691 692 klassOop instanceKlass::array_klass_impl(bool or_null, int n, TRAPS) { 693 instanceKlassHandle this_oop(THREAD, as_klassOop()); 694 return array_klass_impl(this_oop, or_null, n, THREAD); 695 } 696 697 klassOop instanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) { 698 if (this_oop->array_klasses() == NULL) { 699 if (or_null) return NULL; 700 701 ResourceMark rm; 702 JavaThread *jt = (JavaThread *)THREAD; 703 { 704 // Atomic creation of array_klasses 705 MutexLocker mc(Compile_lock, THREAD); // for vtables 706 MutexLocker ma(MultiArray_lock, THREAD); 707 708 // Check if update has already taken place 709 if (this_oop->array_klasses() == NULL) { 710 objArrayKlassKlass* oakk = 711 (objArrayKlassKlass*)Universe::objArrayKlassKlassObj()->klass_part(); 712 713 klassOop k = oakk->allocate_objArray_klass(1, this_oop, CHECK_NULL); 714 this_oop->set_array_klasses(k); 715 } 716 } 717 } 718 // _this will always be set at this point 719 objArrayKlass* oak = (objArrayKlass*)this_oop->array_klasses()->klass_part(); 720 if (or_null) { 721 return oak->array_klass_or_null(n); 722 } 723 return oak->array_klass(n, CHECK_NULL); 724 } 725 726 klassOop instanceKlass::array_klass_impl(bool or_null, TRAPS) { 727 return array_klass_impl(or_null, 1, THREAD); 728 } 729 730 void instanceKlass::call_class_initializer(TRAPS) { 731 instanceKlassHandle ik (THREAD, as_klassOop()); 732 call_class_initializer_impl(ik, THREAD); 733 } 734 735 static int call_class_initializer_impl_counter = 0; // for debugging 736 737 methodOop instanceKlass::class_initializer() { 738 return find_method(vmSymbols::class_initializer_name(), vmSymbols::void_method_signature()); 739 } 740 741 void instanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) { 742 methodHandle h_method(THREAD, this_oop->class_initializer()); 743 assert(!this_oop->is_initialized(), "we cannot initialize twice"); 744 if (TraceClassInitialization) { 745 tty->print("%d Initializing ", call_class_initializer_impl_counter++); 746 this_oop->name()->print_value(); 747 tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop()); 748 } 749 if (h_method() != NULL) { 750 JavaCallArguments args; // No arguments 751 JavaValue result(T_VOID); 752 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args) 753 } 754 } 755 756 757 void instanceKlass::mask_for(methodHandle method, int bci, 758 InterpreterOopMap* entry_for) { 759 // Dirty read, then double-check under a lock. 760 if (_oop_map_cache == NULL) { 761 // Otherwise, allocate a new one. 762 MutexLocker x(OopMapCacheAlloc_lock); 763 // First time use. Allocate a cache in C heap 764 if (_oop_map_cache == NULL) { 765 _oop_map_cache = new OopMapCache(); 766 } 767 } 768 // _oop_map_cache is constant after init; lookup below does is own locking. 769 _oop_map_cache->lookup(method, bci, entry_for); 770 } 771 772 773 bool instanceKlass::find_local_field(symbolOop name, symbolOop sig, fieldDescriptor* fd) const { 774 const int n = fields()->length(); 775 for (int i = 0; i < n; i += next_offset ) { 776 int name_index = fields()->ushort_at(i + name_index_offset); 777 int sig_index = fields()->ushort_at(i + signature_index_offset); 778 symbolOop f_name = constants()->symbol_at(name_index); 779 symbolOop f_sig = constants()->symbol_at(sig_index); 780 if (f_name == name && f_sig == sig) { 781 fd->initialize(as_klassOop(), i); 782 return true; 783 } 784 } 785 return false; 786 } 787 788 789 void instanceKlass::field_names_and_sigs_iterate(OopClosure* closure) { 790 const int n = fields()->length(); 791 for (int i = 0; i < n; i += next_offset ) { 792 int name_index = fields()->ushort_at(i + name_index_offset); 793 symbolOop name = constants()->symbol_at(name_index); 794 closure->do_oop((oop*)&name); 795 796 int sig_index = fields()->ushort_at(i + signature_index_offset); 797 symbolOop sig = constants()->symbol_at(sig_index); 798 closure->do_oop((oop*)&sig); 799 } 800 } 801 802 803 klassOop instanceKlass::find_interface_field(symbolOop name, symbolOop sig, fieldDescriptor* fd) const { 804 const int n = local_interfaces()->length(); 805 for (int i = 0; i < n; i++) { 806 klassOop intf1 = klassOop(local_interfaces()->obj_at(i)); 807 assert(Klass::cast(intf1)->is_interface(), "just checking type"); 808 // search for field in current interface 809 if (instanceKlass::cast(intf1)->find_local_field(name, sig, fd)) { 810 assert(fd->is_static(), "interface field must be static"); 811 return intf1; 812 } 813 // search for field in direct superinterfaces 814 klassOop intf2 = instanceKlass::cast(intf1)->find_interface_field(name, sig, fd); 815 if (intf2 != NULL) return intf2; 816 } 817 // otherwise field lookup fails 818 return NULL; 819 } 820 821 822 klassOop instanceKlass::find_field(symbolOop name, symbolOop sig, fieldDescriptor* fd) const { 823 // search order according to newest JVM spec (5.4.3.2, p.167). 824 // 1) search for field in current klass 825 if (find_local_field(name, sig, fd)) { 826 return as_klassOop(); 827 } 828 // 2) search for field recursively in direct superinterfaces 829 { klassOop intf = find_interface_field(name, sig, fd); 830 if (intf != NULL) return intf; 831 } 832 // 3) apply field lookup recursively if superclass exists 833 { klassOop supr = super(); 834 if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, fd); 835 } 836 // 4) otherwise field lookup fails 837 return NULL; 838 } 839 840 841 klassOop instanceKlass::find_field(symbolOop name, symbolOop sig, bool is_static, fieldDescriptor* fd) const { 842 // search order according to newest JVM spec (5.4.3.2, p.167). 843 // 1) search for field in current klass 844 if (find_local_field(name, sig, fd)) { 845 if (fd->is_static() == is_static) return as_klassOop(); 846 } 847 // 2) search for field recursively in direct superinterfaces 848 if (is_static) { 849 klassOop intf = find_interface_field(name, sig, fd); 850 if (intf != NULL) return intf; 851 } 852 // 3) apply field lookup recursively if superclass exists 853 { klassOop supr = super(); 854 if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, is_static, fd); 855 } 856 // 4) otherwise field lookup fails 857 return NULL; 858 } 859 860 861 bool instanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const { 862 int length = fields()->length(); 863 for (int i = 0; i < length; i += next_offset) { 864 if (offset_from_fields( i ) == offset) { 865 fd->initialize(as_klassOop(), i); 866 if (fd->is_static() == is_static) return true; 867 } 868 } 869 return false; 870 } 871 872 873 bool instanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const { 874 klassOop klass = as_klassOop(); 875 while (klass != NULL) { 876 if (instanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) { 877 return true; 878 } 879 klass = Klass::cast(klass)->super(); 880 } 881 return false; 882 } 883 884 885 void instanceKlass::methods_do(void f(methodOop method)) { 886 int len = methods()->length(); 887 for (int index = 0; index < len; index++) { 888 methodOop m = methodOop(methods()->obj_at(index)); 889 assert(m->is_method(), "must be method"); 890 f(m); 891 } 892 } 893 894 void instanceKlass::do_local_static_fields(FieldClosure* cl) { 895 fieldDescriptor fd; 896 int length = fields()->length(); 897 for (int i = 0; i < length; i += next_offset) { 898 fd.initialize(as_klassOop(), i); 899 if (fd.is_static()) cl->do_field(&fd); 900 } 901 } 902 903 904 void instanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) { 905 instanceKlassHandle h_this(THREAD, as_klassOop()); 906 do_local_static_fields_impl(h_this, f, CHECK); 907 } 908 909 910 void instanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) { 911 fieldDescriptor fd; 912 int length = this_oop->fields()->length(); 913 for (int i = 0; i < length; i += next_offset) { 914 fd.initialize(this_oop(), i); 915 if (fd.is_static()) { f(&fd, CHECK); } // Do NOT remove {}! (CHECK macro expands into several statements) 916 } 917 } 918 919 920 static int compare_fields_by_offset(int* a, int* b) { 921 return a[0] - b[0]; 922 } 923 924 void instanceKlass::do_nonstatic_fields(FieldClosure* cl) { 925 instanceKlass* super = superklass(); 926 if (super != NULL) { 927 super->do_nonstatic_fields(cl); 928 } 929 fieldDescriptor fd; 930 int length = fields()->length(); 931 // In DebugInfo nonstatic fields are sorted by offset. 932 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1)); 933 int j = 0; 934 for (int i = 0; i < length; i += next_offset) { 935 fd.initialize(as_klassOop(), i); 936 if (!fd.is_static()) { 937 fields_sorted[j + 0] = fd.offset(); 938 fields_sorted[j + 1] = i; 939 j += 2; 940 } 941 } 942 if (j > 0) { 943 length = j; 944 // _sort_Fn is defined in growableArray.hpp. 945 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset); 946 for (int i = 0; i < length; i += 2) { 947 fd.initialize(as_klassOop(), fields_sorted[i + 1]); 948 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields"); 949 cl->do_field(&fd); 950 } 951 } 952 FREE_C_HEAP_ARRAY(int, fields_sorted); 953 } 954 955 956 void instanceKlass::array_klasses_do(void f(klassOop k)) { 957 if (array_klasses() != NULL) 958 arrayKlass::cast(array_klasses())->array_klasses_do(f); 959 } 960 961 962 void instanceKlass::with_array_klasses_do(void f(klassOop k)) { 963 f(as_klassOop()); 964 array_klasses_do(f); 965 } 966 967 #ifdef ASSERT 968 static int linear_search(objArrayOop methods, symbolOop name, symbolOop signature) { 969 int len = methods->length(); 970 for (int index = 0; index < len; index++) { 971 methodOop m = (methodOop)(methods->obj_at(index)); 972 assert(m->is_method(), "must be method"); 973 if (m->signature() == signature && m->name() == name) { 974 return index; 975 } 976 } 977 return -1; 978 } 979 #endif 980 981 methodOop instanceKlass::find_method(symbolOop name, symbolOop signature) const { 982 return instanceKlass::find_method(methods(), name, signature); 983 } 984 985 methodOop instanceKlass::find_method(objArrayOop methods, symbolOop name, symbolOop signature) { 986 int len = methods->length(); 987 // methods are sorted, so do binary search 988 int l = 0; 989 int h = len - 1; 990 while (l <= h) { 991 int mid = (l + h) >> 1; 992 methodOop m = (methodOop)methods->obj_at(mid); 993 assert(m->is_method(), "must be method"); 994 int res = m->name()->fast_compare(name); 995 if (res == 0) { 996 // found matching name; do linear search to find matching signature 997 // first, quick check for common case 998 if (m->signature() == signature) return m; 999 // search downwards through overloaded methods 1000 int i; 1001 for (i = mid - 1; i >= l; i--) { 1002 methodOop m = (methodOop)methods->obj_at(i); 1003 assert(m->is_method(), "must be method"); 1004 if (m->name() != name) break; 1005 if (m->signature() == signature) return m; 1006 } 1007 // search upwards 1008 for (i = mid + 1; i <= h; i++) { 1009 methodOop m = (methodOop)methods->obj_at(i); 1010 assert(m->is_method(), "must be method"); 1011 if (m->name() != name) break; 1012 if (m->signature() == signature) return m; 1013 } 1014 // not found 1015 #ifdef ASSERT 1016 int index = linear_search(methods, name, signature); 1017 assert(index == -1, err_msg("binary search should have found entry %d", index)); 1018 #endif 1019 return NULL; 1020 } else if (res < 0) { 1021 l = mid + 1; 1022 } else { 1023 h = mid - 1; 1024 } 1025 } 1026 #ifdef ASSERT 1027 int index = linear_search(methods, name, signature); 1028 assert(index == -1, err_msg("binary search should have found entry %d", index)); 1029 #endif 1030 return NULL; 1031 } 1032 1033 methodOop instanceKlass::uncached_lookup_method(symbolOop name, symbolOop signature) const { 1034 klassOop klass = as_klassOop(); 1035 while (klass != NULL) { 1036 methodOop method = instanceKlass::cast(klass)->find_method(name, signature); 1037 if (method != NULL) return method; 1038 klass = instanceKlass::cast(klass)->super(); 1039 } 1040 return NULL; 1041 } 1042 1043 // lookup a method in all the interfaces that this class implements 1044 methodOop instanceKlass::lookup_method_in_all_interfaces(symbolOop name, 1045 symbolOop signature) const { 1046 objArrayOop all_ifs = instanceKlass::cast(as_klassOop())->transitive_interfaces(); 1047 int num_ifs = all_ifs->length(); 1048 instanceKlass *ik = NULL; 1049 for (int i = 0; i < num_ifs; i++) { 1050 ik = instanceKlass::cast(klassOop(all_ifs->obj_at(i))); 1051 methodOop m = ik->lookup_method(name, signature); 1052 if (m != NULL) { 1053 return m; 1054 } 1055 } 1056 return NULL; 1057 } 1058 1059 /* jni_id_for_impl for jfieldIds only */ 1060 JNIid* instanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) { 1061 MutexLocker ml(JfieldIdCreation_lock); 1062 // Retry lookup after we got the lock 1063 JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset); 1064 if (probe == NULL) { 1065 // Slow case, allocate new static field identifier 1066 probe = new JNIid(this_oop->as_klassOop(), offset, this_oop->jni_ids()); 1067 this_oop->set_jni_ids(probe); 1068 } 1069 return probe; 1070 } 1071 1072 1073 /* jni_id_for for jfieldIds only */ 1074 JNIid* instanceKlass::jni_id_for(int offset) { 1075 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset); 1076 if (probe == NULL) { 1077 probe = jni_id_for_impl(this->as_klassOop(), offset); 1078 } 1079 return probe; 1080 } 1081 1082 1083 // Lookup or create a jmethodID. 1084 // This code is called by the VMThread and JavaThreads so the 1085 // locking has to be done very carefully to avoid deadlocks 1086 // and/or other cache consistency problems. 1087 // 1088 jmethodID instanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) { 1089 size_t idnum = (size_t)method_h->method_idnum(); 1090 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire(); 1091 size_t length = 0; 1092 jmethodID id = NULL; 1093 1094 // We use a double-check locking idiom here because this cache is 1095 // performance sensitive. In the normal system, this cache only 1096 // transitions from NULL to non-NULL which is safe because we use 1097 // release_set_methods_jmethod_ids() to advertise the new cache. 1098 // A partially constructed cache should never be seen by a racing 1099 // thread. We also use release_store_ptr() to save a new jmethodID 1100 // in the cache so a partially constructed jmethodID should never be 1101 // seen either. Cache reads of existing jmethodIDs proceed without a 1102 // lock, but cache writes of a new jmethodID requires uniqueness and 1103 // creation of the cache itself requires no leaks so a lock is 1104 // generally acquired in those two cases. 1105 // 1106 // If the RedefineClasses() API has been used, then this cache can 1107 // grow and we'll have transitions from non-NULL to bigger non-NULL. 1108 // Cache creation requires no leaks and we require safety between all 1109 // cache accesses and freeing of the old cache so a lock is generally 1110 // acquired when the RedefineClasses() API has been used. 1111 1112 if (jmeths != NULL) { 1113 // the cache already exists 1114 if (!ik_h->idnum_can_increment()) { 1115 // the cache can't grow so we can just get the current values 1116 get_jmethod_id_length_value(jmeths, idnum, &length, &id); 1117 } else { 1118 // cache can grow so we have to be more careful 1119 if (Threads::number_of_threads() == 0 || 1120 SafepointSynchronize::is_at_safepoint()) { 1121 // we're single threaded or at a safepoint - no locking needed 1122 get_jmethod_id_length_value(jmeths, idnum, &length, &id); 1123 } else { 1124 MutexLocker ml(JmethodIdCreation_lock); 1125 get_jmethod_id_length_value(jmeths, idnum, &length, &id); 1126 } 1127 } 1128 } 1129 // implied else: 1130 // we need to allocate a cache so default length and id values are good 1131 1132 if (jmeths == NULL || // no cache yet 1133 length <= idnum || // cache is too short 1134 id == NULL) { // cache doesn't contain entry 1135 1136 // This function can be called by the VMThread so we have to do all 1137 // things that might block on a safepoint before grabbing the lock. 1138 // Otherwise, we can deadlock with the VMThread or have a cache 1139 // consistency issue. These vars keep track of what we might have 1140 // to free after the lock is dropped. 1141 jmethodID to_dealloc_id = NULL; 1142 jmethodID* to_dealloc_jmeths = NULL; 1143 1144 // may not allocate new_jmeths or use it if we allocate it 1145 jmethodID* new_jmeths = NULL; 1146 if (length <= idnum) { 1147 // allocate a new cache that might be used 1148 size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count()); 1149 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1); 1150 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID)); 1151 // cache size is stored in element[0], other elements offset by one 1152 new_jmeths[0] = (jmethodID)size; 1153 } 1154 1155 // allocate a new jmethodID that might be used 1156 jmethodID new_id = NULL; 1157 if (method_h->is_old() && !method_h->is_obsolete()) { 1158 // The method passed in is old (but not obsolete), we need to use the current version 1159 methodOop current_method = ik_h->method_with_idnum((int)idnum); 1160 assert(current_method != NULL, "old and but not obsolete, so should exist"); 1161 methodHandle current_method_h(current_method == NULL? method_h() : current_method); 1162 new_id = JNIHandles::make_jmethod_id(current_method_h); 1163 } else { 1164 // It is the current version of the method or an obsolete method, 1165 // use the version passed in 1166 new_id = JNIHandles::make_jmethod_id(method_h); 1167 } 1168 1169 if (Threads::number_of_threads() == 0 || 1170 SafepointSynchronize::is_at_safepoint()) { 1171 // we're single threaded or at a safepoint - no locking needed 1172 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths, 1173 &to_dealloc_id, &to_dealloc_jmeths); 1174 } else { 1175 MutexLocker ml(JmethodIdCreation_lock); 1176 id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths, 1177 &to_dealloc_id, &to_dealloc_jmeths); 1178 } 1179 1180 // The lock has been dropped so we can free resources. 1181 // Free up either the old cache or the new cache if we allocated one. 1182 if (to_dealloc_jmeths != NULL) { 1183 FreeHeap(to_dealloc_jmeths); 1184 } 1185 // free up the new ID since it wasn't needed 1186 if (to_dealloc_id != NULL) { 1187 JNIHandles::destroy_jmethod_id(to_dealloc_id); 1188 } 1189 } 1190 return id; 1191 } 1192 1193 1194 // Common code to fetch the jmethodID from the cache or update the 1195 // cache with the new jmethodID. This function should never do anything 1196 // that causes the caller to go to a safepoint or we can deadlock with 1197 // the VMThread or have cache consistency issues. 1198 // 1199 jmethodID instanceKlass::get_jmethod_id_fetch_or_update( 1200 instanceKlassHandle ik_h, size_t idnum, jmethodID new_id, 1201 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p, 1202 jmethodID** to_dealloc_jmeths_p) { 1203 assert(new_id != NULL, "sanity check"); 1204 assert(to_dealloc_id_p != NULL, "sanity check"); 1205 assert(to_dealloc_jmeths_p != NULL, "sanity check"); 1206 assert(Threads::number_of_threads() == 0 || 1207 SafepointSynchronize::is_at_safepoint() || 1208 JmethodIdCreation_lock->owned_by_self(), "sanity check"); 1209 1210 // reacquire the cache - we are locked, single threaded or at a safepoint 1211 jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire(); 1212 jmethodID id = NULL; 1213 size_t length = 0; 1214 1215 if (jmeths == NULL || // no cache yet 1216 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short 1217 if (jmeths != NULL) { 1218 // copy any existing entries from the old cache 1219 for (size_t index = 0; index < length; index++) { 1220 new_jmeths[index+1] = jmeths[index+1]; 1221 } 1222 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete 1223 } 1224 ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths); 1225 } else { 1226 // fetch jmethodID (if any) from the existing cache 1227 id = jmeths[idnum+1]; 1228 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete 1229 } 1230 if (id == NULL) { 1231 // No matching jmethodID in the existing cache or we have a new 1232 // cache or we just grew the cache. This cache write is done here 1233 // by the first thread to win the foot race because a jmethodID 1234 // needs to be unique once it is generally available. 1235 id = new_id; 1236 1237 // The jmethodID cache can be read while unlocked so we have to 1238 // make sure the new jmethodID is complete before installing it 1239 // in the cache. 1240 OrderAccess::release_store_ptr(&jmeths[idnum+1], id); 1241 } else { 1242 *to_dealloc_id_p = new_id; // save new id for later delete 1243 } 1244 return id; 1245 } 1246 1247 1248 // Common code to get the jmethodID cache length and the jmethodID 1249 // value at index idnum if there is one. 1250 // 1251 void instanceKlass::get_jmethod_id_length_value(jmethodID* cache, 1252 size_t idnum, size_t *length_p, jmethodID* id_p) { 1253 assert(cache != NULL, "sanity check"); 1254 assert(length_p != NULL, "sanity check"); 1255 assert(id_p != NULL, "sanity check"); 1256 1257 // cache size is stored in element[0], other elements offset by one 1258 *length_p = (size_t)cache[0]; 1259 if (*length_p <= idnum) { // cache is too short 1260 *id_p = NULL; 1261 } else { 1262 *id_p = cache[idnum+1]; // fetch jmethodID (if any) 1263 } 1264 } 1265 1266 1267 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles 1268 jmethodID instanceKlass::jmethod_id_or_null(methodOop method) { 1269 size_t idnum = (size_t)method->method_idnum(); 1270 jmethodID* jmeths = methods_jmethod_ids_acquire(); 1271 size_t length; // length assigned as debugging crumb 1272 jmethodID id = NULL; 1273 if (jmeths != NULL && // If there is a cache 1274 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough, 1275 id = jmeths[idnum+1]; // Look up the id (may be NULL) 1276 } 1277 return id; 1278 } 1279 1280 1281 // Cache an itable index 1282 void instanceKlass::set_cached_itable_index(size_t idnum, int index) { 1283 int* indices = methods_cached_itable_indices_acquire(); 1284 int* to_dealloc_indices = NULL; 1285 1286 // We use a double-check locking idiom here because this cache is 1287 // performance sensitive. In the normal system, this cache only 1288 // transitions from NULL to non-NULL which is safe because we use 1289 // release_set_methods_cached_itable_indices() to advertise the 1290 // new cache. A partially constructed cache should never be seen 1291 // by a racing thread. Cache reads and writes proceed without a 1292 // lock, but creation of the cache itself requires no leaks so a 1293 // lock is generally acquired in that case. 1294 // 1295 // If the RedefineClasses() API has been used, then this cache can 1296 // grow and we'll have transitions from non-NULL to bigger non-NULL. 1297 // Cache creation requires no leaks and we require safety between all 1298 // cache accesses and freeing of the old cache so a lock is generally 1299 // acquired when the RedefineClasses() API has been used. 1300 1301 if (indices == NULL || idnum_can_increment()) { 1302 // we need a cache or the cache can grow 1303 MutexLocker ml(JNICachedItableIndex_lock); 1304 // reacquire the cache to see if another thread already did the work 1305 indices = methods_cached_itable_indices_acquire(); 1306 size_t length = 0; 1307 // cache size is stored in element[0], other elements offset by one 1308 if (indices == NULL || (length = (size_t)indices[0]) <= idnum) { 1309 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count()); 1310 int* new_indices = NEW_C_HEAP_ARRAY(int, size+1); 1311 new_indices[0] = (int)size; 1312 // copy any existing entries 1313 size_t i; 1314 for (i = 0; i < length; i++) { 1315 new_indices[i+1] = indices[i+1]; 1316 } 1317 // Set all the rest to -1 1318 for (i = length; i < size; i++) { 1319 new_indices[i+1] = -1; 1320 } 1321 if (indices != NULL) { 1322 // We have an old cache to delete so save it for after we 1323 // drop the lock. 1324 to_dealloc_indices = indices; 1325 } 1326 release_set_methods_cached_itable_indices(indices = new_indices); 1327 } 1328 1329 if (idnum_can_increment()) { 1330 // this cache can grow so we have to write to it safely 1331 indices[idnum+1] = index; 1332 } 1333 } else { 1334 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops()); 1335 } 1336 1337 if (!idnum_can_increment()) { 1338 // The cache cannot grow and this JNI itable index value does not 1339 // have to be unique like a jmethodID. If there is a race to set it, 1340 // it doesn't matter. 1341 indices[idnum+1] = index; 1342 } 1343 1344 if (to_dealloc_indices != NULL) { 1345 // we allocated a new cache so free the old one 1346 FreeHeap(to_dealloc_indices); 1347 } 1348 } 1349 1350 1351 // Retrieve a cached itable index 1352 int instanceKlass::cached_itable_index(size_t idnum) { 1353 int* indices = methods_cached_itable_indices_acquire(); 1354 if (indices != NULL && ((size_t)indices[0]) > idnum) { 1355 // indices exist and are long enough, retrieve possible cached 1356 return indices[idnum+1]; 1357 } 1358 return -1; 1359 } 1360 1361 1362 // 1363 // nmethodBucket is used to record dependent nmethods for 1364 // deoptimization. nmethod dependencies are actually <klass, method> 1365 // pairs but we really only care about the klass part for purposes of 1366 // finding nmethods which might need to be deoptimized. Instead of 1367 // recording the method, a count of how many times a particular nmethod 1368 // was recorded is kept. This ensures that any recording errors are 1369 // noticed since an nmethod should be removed as many times are it's 1370 // added. 1371 // 1372 class nmethodBucket { 1373 private: 1374 nmethod* _nmethod; 1375 int _count; 1376 nmethodBucket* _next; 1377 1378 public: 1379 nmethodBucket(nmethod* nmethod, nmethodBucket* next) { 1380 _nmethod = nmethod; 1381 _next = next; 1382 _count = 1; 1383 } 1384 int count() { return _count; } 1385 int increment() { _count += 1; return _count; } 1386 int decrement() { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; } 1387 nmethodBucket* next() { return _next; } 1388 void set_next(nmethodBucket* b) { _next = b; } 1389 nmethod* get_nmethod() { return _nmethod; } 1390 }; 1391 1392 1393 // 1394 // Walk the list of dependent nmethods searching for nmethods which 1395 // are dependent on the klassOop that was passed in and mark them for 1396 // deoptimization. Returns the number of nmethods found. 1397 // 1398 int instanceKlass::mark_dependent_nmethods(DepChange& changes) { 1399 assert_locked_or_safepoint(CodeCache_lock); 1400 int found = 0; 1401 nmethodBucket* b = _dependencies; 1402 while (b != NULL) { 1403 nmethod* nm = b->get_nmethod(); 1404 // since dependencies aren't removed until an nmethod becomes a zombie, 1405 // the dependency list may contain nmethods which aren't alive. 1406 if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) { 1407 if (TraceDependencies) { 1408 ResourceMark rm; 1409 tty->print_cr("Marked for deoptimization"); 1410 tty->print_cr(" context = %s", this->external_name()); 1411 changes.print(); 1412 nm->print(); 1413 nm->print_dependencies(); 1414 } 1415 nm->mark_for_deoptimization(); 1416 found++; 1417 } 1418 b = b->next(); 1419 } 1420 return found; 1421 } 1422 1423 1424 // 1425 // Add an nmethodBucket to the list of dependencies for this nmethod. 1426 // It's possible that an nmethod has multiple dependencies on this klass 1427 // so a count is kept for each bucket to guarantee that creation and 1428 // deletion of dependencies is consistent. 1429 // 1430 void instanceKlass::add_dependent_nmethod(nmethod* nm) { 1431 assert_locked_or_safepoint(CodeCache_lock); 1432 nmethodBucket* b = _dependencies; 1433 nmethodBucket* last = NULL; 1434 while (b != NULL) { 1435 if (nm == b->get_nmethod()) { 1436 b->increment(); 1437 return; 1438 } 1439 b = b->next(); 1440 } 1441 _dependencies = new nmethodBucket(nm, _dependencies); 1442 } 1443 1444 1445 // 1446 // Decrement count of the nmethod in the dependency list and remove 1447 // the bucket competely when the count goes to 0. This method must 1448 // find a corresponding bucket otherwise there's a bug in the 1449 // recording of dependecies. 1450 // 1451 void instanceKlass::remove_dependent_nmethod(nmethod* nm) { 1452 assert_locked_or_safepoint(CodeCache_lock); 1453 nmethodBucket* b = _dependencies; 1454 nmethodBucket* last = NULL; 1455 while (b != NULL) { 1456 if (nm == b->get_nmethod()) { 1457 if (b->decrement() == 0) { 1458 if (last == NULL) { 1459 _dependencies = b->next(); 1460 } else { 1461 last->set_next(b->next()); 1462 } 1463 delete b; 1464 } 1465 return; 1466 } 1467 last = b; 1468 b = b->next(); 1469 } 1470 #ifdef ASSERT 1471 tty->print_cr("### %s can't find dependent nmethod:", this->external_name()); 1472 nm->print(); 1473 #endif // ASSERT 1474 ShouldNotReachHere(); 1475 } 1476 1477 1478 #ifndef PRODUCT 1479 void instanceKlass::print_dependent_nmethods(bool verbose) { 1480 nmethodBucket* b = _dependencies; 1481 int idx = 0; 1482 while (b != NULL) { 1483 nmethod* nm = b->get_nmethod(); 1484 tty->print("[%d] count=%d { ", idx++, b->count()); 1485 if (!verbose) { 1486 nm->print_on(tty, "nmethod"); 1487 tty->print_cr(" } "); 1488 } else { 1489 nm->print(); 1490 nm->print_dependencies(); 1491 tty->print_cr("--- } "); 1492 } 1493 b = b->next(); 1494 } 1495 } 1496 1497 1498 bool instanceKlass::is_dependent_nmethod(nmethod* nm) { 1499 nmethodBucket* b = _dependencies; 1500 while (b != NULL) { 1501 if (nm == b->get_nmethod()) { 1502 return true; 1503 } 1504 b = b->next(); 1505 } 1506 return false; 1507 } 1508 #endif //PRODUCT 1509 1510 1511 #ifdef ASSERT 1512 template <class T> void assert_is_in(T *p) { 1513 T heap_oop = oopDesc::load_heap_oop(p); 1514 if (!oopDesc::is_null(heap_oop)) { 1515 oop o = oopDesc::decode_heap_oop_not_null(heap_oop); 1516 assert(Universe::heap()->is_in(o), "should be in heap"); 1517 } 1518 } 1519 template <class T> void assert_is_in_closed_subset(T *p) { 1520 T heap_oop = oopDesc::load_heap_oop(p); 1521 if (!oopDesc::is_null(heap_oop)) { 1522 oop o = oopDesc::decode_heap_oop_not_null(heap_oop); 1523 assert(Universe::heap()->is_in_closed_subset(o), "should be in closed"); 1524 } 1525 } 1526 template <class T> void assert_is_in_reserved(T *p) { 1527 T heap_oop = oopDesc::load_heap_oop(p); 1528 if (!oopDesc::is_null(heap_oop)) { 1529 oop o = oopDesc::decode_heap_oop_not_null(heap_oop); 1530 assert(Universe::heap()->is_in_reserved(o), "should be in reserved"); 1531 } 1532 } 1533 template <class T> void assert_nothing(T *p) {} 1534 1535 #else 1536 template <class T> void assert_is_in(T *p) {} 1537 template <class T> void assert_is_in_closed_subset(T *p) {} 1538 template <class T> void assert_is_in_reserved(T *p) {} 1539 template <class T> void assert_nothing(T *p) {} 1540 #endif // ASSERT 1541 1542 // 1543 // Macros that iterate over areas of oops which are specialized on type of 1544 // oop pointer either narrow or wide, depending on UseCompressedOops 1545 // 1546 // Parameters are: 1547 // T - type of oop to point to (either oop or narrowOop) 1548 // start_p - starting pointer for region to iterate over 1549 // count - number of oops or narrowOops to iterate over 1550 // do_oop - action to perform on each oop (it's arbitrary C code which 1551 // makes it more efficient to put in a macro rather than making 1552 // it a template function) 1553 // assert_fn - assert function which is template function because performance 1554 // doesn't matter when enabled. 1555 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \ 1556 T, start_p, count, do_oop, \ 1557 assert_fn) \ 1558 { \ 1559 T* p = (T*)(start_p); \ 1560 T* const end = p + (count); \ 1561 while (p < end) { \ 1562 (assert_fn)(p); \ 1563 do_oop; \ 1564 ++p; \ 1565 } \ 1566 } 1567 1568 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \ 1569 T, start_p, count, do_oop, \ 1570 assert_fn) \ 1571 { \ 1572 T* const start = (T*)(start_p); \ 1573 T* p = start + (count); \ 1574 while (start < p) { \ 1575 --p; \ 1576 (assert_fn)(p); \ 1577 do_oop; \ 1578 } \ 1579 } 1580 1581 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \ 1582 T, start_p, count, low, high, \ 1583 do_oop, assert_fn) \ 1584 { \ 1585 T* const l = (T*)(low); \ 1586 T* const h = (T*)(high); \ 1587 assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \ 1588 mask_bits((intptr_t)h, sizeof(T)-1) == 0, \ 1589 "bounded region must be properly aligned"); \ 1590 T* p = (T*)(start_p); \ 1591 T* end = p + (count); \ 1592 if (p < l) p = l; \ 1593 if (end > h) end = h; \ 1594 while (p < end) { \ 1595 (assert_fn)(p); \ 1596 do_oop; \ 1597 ++p; \ 1598 } \ 1599 } 1600 1601 1602 // The following macros call specialized macros, passing either oop or 1603 // narrowOop as the specialization type. These test the UseCompressedOops 1604 // flag. 1605 #define InstanceKlass_OOP_ITERATE(start_p, count, \ 1606 do_oop, assert_fn) \ 1607 { \ 1608 if (UseCompressedOops) { \ 1609 InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \ 1610 start_p, count, \ 1611 do_oop, assert_fn) \ 1612 } else { \ 1613 InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \ 1614 start_p, count, \ 1615 do_oop, assert_fn) \ 1616 } \ 1617 } 1618 1619 #define InstanceKlass_BOUNDED_OOP_ITERATE(start_p, count, low, high, \ 1620 do_oop, assert_fn) \ 1621 { \ 1622 if (UseCompressedOops) { \ 1623 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \ 1624 start_p, count, \ 1625 low, high, \ 1626 do_oop, assert_fn) \ 1627 } else { \ 1628 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \ 1629 start_p, count, \ 1630 low, high, \ 1631 do_oop, assert_fn) \ 1632 } \ 1633 } 1634 1635 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \ 1636 { \ 1637 /* Compute oopmap block range. The common case \ 1638 is nonstatic_oop_map_size == 1. */ \ 1639 OopMapBlock* map = start_of_nonstatic_oop_maps(); \ 1640 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \ 1641 if (UseCompressedOops) { \ 1642 while (map < end_map) { \ 1643 InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \ 1644 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \ 1645 do_oop, assert_fn) \ 1646 ++map; \ 1647 } \ 1648 } else { \ 1649 while (map < end_map) { \ 1650 InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \ 1651 obj->obj_field_addr<oop>(map->offset()), map->count(), \ 1652 do_oop, assert_fn) \ 1653 ++map; \ 1654 } \ 1655 } \ 1656 } 1657 1658 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \ 1659 { \ 1660 OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \ 1661 OopMapBlock* map = start_map + nonstatic_oop_map_count(); \ 1662 if (UseCompressedOops) { \ 1663 while (start_map < map) { \ 1664 --map; \ 1665 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \ 1666 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \ 1667 do_oop, assert_fn) \ 1668 } \ 1669 } else { \ 1670 while (start_map < map) { \ 1671 --map; \ 1672 InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \ 1673 obj->obj_field_addr<oop>(map->offset()), map->count(), \ 1674 do_oop, assert_fn) \ 1675 } \ 1676 } \ 1677 } 1678 1679 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \ 1680 assert_fn) \ 1681 { \ 1682 /* Compute oopmap block range. The common case is \ 1683 nonstatic_oop_map_size == 1, so we accept the \ 1684 usually non-existent extra overhead of examining \ 1685 all the maps. */ \ 1686 OopMapBlock* map = start_of_nonstatic_oop_maps(); \ 1687 OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \ 1688 if (UseCompressedOops) { \ 1689 while (map < end_map) { \ 1690 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \ 1691 obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \ 1692 low, high, \ 1693 do_oop, assert_fn) \ 1694 ++map; \ 1695 } \ 1696 } else { \ 1697 while (map < end_map) { \ 1698 InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \ 1699 obj->obj_field_addr<oop>(map->offset()), map->count(), \ 1700 low, high, \ 1701 do_oop, assert_fn) \ 1702 ++map; \ 1703 } \ 1704 } \ 1705 } 1706 1707 void instanceKlass::follow_static_fields() { 1708 InstanceKlass_OOP_ITERATE( \ 1709 start_of_static_fields(), static_oop_field_size(), \ 1710 MarkSweep::mark_and_push(p), \ 1711 assert_is_in_closed_subset) 1712 } 1713 1714 #ifndef SERIALGC 1715 void instanceKlass::follow_static_fields(ParCompactionManager* cm) { 1716 InstanceKlass_OOP_ITERATE( \ 1717 start_of_static_fields(), static_oop_field_size(), \ 1718 PSParallelCompact::mark_and_push(cm, p), \ 1719 assert_is_in) 1720 } 1721 #endif // SERIALGC 1722 1723 void instanceKlass::adjust_static_fields() { 1724 InstanceKlass_OOP_ITERATE( \ 1725 start_of_static_fields(), static_oop_field_size(), \ 1726 MarkSweep::adjust_pointer(p), \ 1727 assert_nothing) 1728 } 1729 1730 #ifndef SERIALGC 1731 void instanceKlass::update_static_fields() { 1732 InstanceKlass_OOP_ITERATE( \ 1733 start_of_static_fields(), static_oop_field_size(), \ 1734 PSParallelCompact::adjust_pointer(p), \ 1735 assert_nothing) 1736 } 1737 1738 void instanceKlass::update_static_fields(HeapWord* beg_addr, HeapWord* end_addr) { 1739 InstanceKlass_BOUNDED_OOP_ITERATE( \ 1740 start_of_static_fields(), static_oop_field_size(), \ 1741 beg_addr, end_addr, \ 1742 PSParallelCompact::adjust_pointer(p), \ 1743 assert_nothing ) 1744 } 1745 #endif // SERIALGC 1746 1747 void instanceKlass::oop_follow_contents(oop obj) { 1748 assert(obj != NULL, "can't follow the content of NULL object"); 1749 obj->follow_header(); 1750 InstanceKlass_OOP_MAP_ITERATE( \ 1751 obj, \ 1752 MarkSweep::mark_and_push(p), \ 1753 assert_is_in_closed_subset) 1754 } 1755 1756 #ifndef SERIALGC 1757 void instanceKlass::oop_follow_contents(ParCompactionManager* cm, 1758 oop obj) { 1759 assert(obj != NULL, "can't follow the content of NULL object"); 1760 obj->follow_header(cm); 1761 InstanceKlass_OOP_MAP_ITERATE( \ 1762 obj, \ 1763 PSParallelCompact::mark_and_push(cm, p), \ 1764 assert_is_in) 1765 } 1766 #endif // SERIALGC 1767 1768 // closure's do_header() method dicates whether the given closure should be 1769 // applied to the klass ptr in the object header. 1770 1771 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ 1772 \ 1773 int instanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \ 1774 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\ 1775 /* header */ \ 1776 if (closure->do_header()) { \ 1777 obj->oop_iterate_header(closure); \ 1778 } \ 1779 InstanceKlass_OOP_MAP_ITERATE( \ 1780 obj, \ 1781 SpecializationStats:: \ 1782 record_do_oop_call##nv_suffix(SpecializationStats::ik); \ 1783 (closure)->do_oop##nv_suffix(p), \ 1784 assert_is_in_closed_subset) \ 1785 return size_helper(); \ 1786 } 1787 1788 #ifndef SERIALGC 1789 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \ 1790 \ 1791 int instanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \ 1792 OopClosureType* closure) { \ 1793 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \ 1794 /* header */ \ 1795 if (closure->do_header()) { \ 1796 obj->oop_iterate_header(closure); \ 1797 } \ 1798 /* instance variables */ \ 1799 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \ 1800 obj, \ 1801 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\ 1802 (closure)->do_oop##nv_suffix(p), \ 1803 assert_is_in_closed_subset) \ 1804 return size_helper(); \ 1805 } 1806 #endif // !SERIALGC 1807 1808 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \ 1809 \ 1810 int instanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \ 1811 OopClosureType* closure, \ 1812 MemRegion mr) { \ 1813 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\ 1814 if (closure->do_header()) { \ 1815 obj->oop_iterate_header(closure, mr); \ 1816 } \ 1817 InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \ 1818 obj, mr.start(), mr.end(), \ 1819 (closure)->do_oop##nv_suffix(p), \ 1820 assert_is_in_closed_subset) \ 1821 return size_helper(); \ 1822 } 1823 1824 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN) 1825 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN) 1826 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m) 1827 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m) 1828 #ifndef SERIALGC 1829 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN) 1830 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN) 1831 #endif // !SERIALGC 1832 1833 void instanceKlass::iterate_static_fields(OopClosure* closure) { 1834 InstanceKlass_OOP_ITERATE( \ 1835 start_of_static_fields(), static_oop_field_size(), \ 1836 closure->do_oop(p), \ 1837 assert_is_in_reserved) 1838 } 1839 1840 void instanceKlass::iterate_static_fields(OopClosure* closure, 1841 MemRegion mr) { 1842 InstanceKlass_BOUNDED_OOP_ITERATE( \ 1843 start_of_static_fields(), static_oop_field_size(), \ 1844 mr.start(), mr.end(), \ 1845 (closure)->do_oop_v(p), \ 1846 assert_is_in_closed_subset) 1847 } 1848 1849 int instanceKlass::oop_adjust_pointers(oop obj) { 1850 int size = size_helper(); 1851 InstanceKlass_OOP_MAP_ITERATE( \ 1852 obj, \ 1853 MarkSweep::adjust_pointer(p), \ 1854 assert_is_in) 1855 obj->adjust_header(); 1856 return size; 1857 } 1858 1859 #ifndef SERIALGC 1860 void instanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) { 1861 InstanceKlass_OOP_MAP_REVERSE_ITERATE( \ 1862 obj, \ 1863 if (PSScavenge::should_scavenge(p)) { \ 1864 pm->claim_or_forward_depth(p); \ 1865 }, \ 1866 assert_nothing ) 1867 } 1868 1869 int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) { 1870 InstanceKlass_OOP_MAP_ITERATE( \ 1871 obj, \ 1872 PSParallelCompact::adjust_pointer(p), \ 1873 assert_nothing) 1874 return size_helper(); 1875 } 1876 1877 int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj, 1878 HeapWord* beg_addr, HeapWord* end_addr) { 1879 InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \ 1880 obj, beg_addr, end_addr, \ 1881 PSParallelCompact::adjust_pointer(p), \ 1882 assert_nothing) 1883 return size_helper(); 1884 } 1885 1886 void instanceKlass::push_static_fields(PSPromotionManager* pm) { 1887 InstanceKlass_OOP_ITERATE( \ 1888 start_of_static_fields(), static_oop_field_size(), \ 1889 if (PSScavenge::should_scavenge(p)) { \ 1890 pm->claim_or_forward_depth(p); \ 1891 }, \ 1892 assert_nothing ) 1893 } 1894 1895 void instanceKlass::copy_static_fields(ParCompactionManager* cm) { 1896 InstanceKlass_OOP_ITERATE( \ 1897 start_of_static_fields(), static_oop_field_size(), \ 1898 PSParallelCompact::adjust_pointer(p), \ 1899 assert_is_in) 1900 } 1901 #endif // SERIALGC 1902 1903 // This klass is alive but the implementor link is not followed/updated. 1904 // Subklass and sibling links are handled by Klass::follow_weak_klass_links 1905 1906 void instanceKlass::follow_weak_klass_links( 1907 BoolObjectClosure* is_alive, OopClosure* keep_alive) { 1908 assert(is_alive->do_object_b(as_klassOop()), "this oop should be live"); 1909 if (ClassUnloading) { 1910 for (int i = 0; i < implementors_limit; i++) { 1911 klassOop impl = _implementors[i]; 1912 if (impl == NULL) break; // no more in the list 1913 if (!is_alive->do_object_b(impl)) { 1914 // remove this guy from the list by overwriting him with the tail 1915 int lasti = --_nof_implementors; 1916 assert(lasti >= i && lasti < implementors_limit, "just checking"); 1917 _implementors[i] = _implementors[lasti]; 1918 _implementors[lasti] = NULL; 1919 --i; // rerun the loop at this index 1920 } 1921 } 1922 } else { 1923 for (int i = 0; i < implementors_limit; i++) { 1924 keep_alive->do_oop(&adr_implementors()[i]); 1925 } 1926 } 1927 Klass::follow_weak_klass_links(is_alive, keep_alive); 1928 } 1929 1930 void instanceKlass::remove_unshareable_info() { 1931 Klass::remove_unshareable_info(); 1932 init_implementor(); 1933 } 1934 1935 static void clear_all_breakpoints(methodOop m) { 1936 m->clear_all_breakpoints(); 1937 } 1938 1939 void instanceKlass::release_C_heap_structures() { 1940 // Deallocate oop map cache 1941 if (_oop_map_cache != NULL) { 1942 delete _oop_map_cache; 1943 _oop_map_cache = NULL; 1944 } 1945 1946 // Deallocate JNI identifiers for jfieldIDs 1947 JNIid::deallocate(jni_ids()); 1948 set_jni_ids(NULL); 1949 1950 jmethodID* jmeths = methods_jmethod_ids_acquire(); 1951 if (jmeths != (jmethodID*)NULL) { 1952 release_set_methods_jmethod_ids(NULL); 1953 FreeHeap(jmeths); 1954 } 1955 1956 int* indices = methods_cached_itable_indices_acquire(); 1957 if (indices != (int*)NULL) { 1958 release_set_methods_cached_itable_indices(NULL); 1959 FreeHeap(indices); 1960 } 1961 1962 // release dependencies 1963 nmethodBucket* b = _dependencies; 1964 _dependencies = NULL; 1965 while (b != NULL) { 1966 nmethodBucket* next = b->next(); 1967 delete b; 1968 b = next; 1969 } 1970 1971 // Deallocate breakpoint records 1972 if (breakpoints() != 0x0) { 1973 methods_do(clear_all_breakpoints); 1974 assert(breakpoints() == 0x0, "should have cleared breakpoints"); 1975 } 1976 1977 // deallocate information about previous versions 1978 if (_previous_versions != NULL) { 1979 for (int i = _previous_versions->length() - 1; i >= 0; i--) { 1980 PreviousVersionNode * pv_node = _previous_versions->at(i); 1981 delete pv_node; 1982 } 1983 delete _previous_versions; 1984 _previous_versions = NULL; 1985 } 1986 1987 // deallocate the cached class file 1988 if (_cached_class_file_bytes != NULL) { 1989 os::free(_cached_class_file_bytes); 1990 _cached_class_file_bytes = NULL; 1991 _cached_class_file_len = 0; 1992 } 1993 } 1994 1995 const char* instanceKlass::signature_name() const { 1996 const char* src = (const char*) (name()->as_C_string()); 1997 const int src_length = (int)strlen(src); 1998 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3); 1999 int src_index = 0; 2000 int dest_index = 0; 2001 dest[dest_index++] = 'L'; 2002 while (src_index < src_length) { 2003 dest[dest_index++] = src[src_index++]; 2004 } 2005 dest[dest_index++] = ';'; 2006 dest[dest_index] = '\0'; 2007 return dest; 2008 } 2009 2010 // different verisons of is_same_class_package 2011 bool instanceKlass::is_same_class_package(klassOop class2) { 2012 klassOop class1 = as_klassOop(); 2013 oop classloader1 = instanceKlass::cast(class1)->class_loader(); 2014 symbolOop classname1 = Klass::cast(class1)->name(); 2015 2016 if (Klass::cast(class2)->oop_is_objArray()) { 2017 class2 = objArrayKlass::cast(class2)->bottom_klass(); 2018 } 2019 oop classloader2; 2020 if (Klass::cast(class2)->oop_is_instance()) { 2021 classloader2 = instanceKlass::cast(class2)->class_loader(); 2022 } else { 2023 assert(Klass::cast(class2)->oop_is_typeArray(), "should be type array"); 2024 classloader2 = NULL; 2025 } 2026 symbolOop classname2 = Klass::cast(class2)->name(); 2027 2028 return instanceKlass::is_same_class_package(classloader1, classname1, 2029 classloader2, classname2); 2030 } 2031 2032 bool instanceKlass::is_same_class_package(oop classloader2, symbolOop classname2) { 2033 klassOop class1 = as_klassOop(); 2034 oop classloader1 = instanceKlass::cast(class1)->class_loader(); 2035 symbolOop classname1 = Klass::cast(class1)->name(); 2036 2037 return instanceKlass::is_same_class_package(classloader1, classname1, 2038 classloader2, classname2); 2039 } 2040 2041 // return true if two classes are in the same package, classloader 2042 // and classname information is enough to determine a class's package 2043 bool instanceKlass::is_same_class_package(oop class_loader1, symbolOop class_name1, 2044 oop class_loader2, symbolOop class_name2) { 2045 if (class_loader1 != class_loader2) { 2046 return false; 2047 } else if (class_name1 == class_name2) { 2048 return true; // skip painful bytewise comparison 2049 } else { 2050 ResourceMark rm; 2051 2052 // The symbolOop's are in UTF8 encoding. Since we only need to check explicitly 2053 // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding. 2054 // Otherwise, we just compare jbyte values between the strings. 2055 jbyte *name1 = class_name1->base(); 2056 jbyte *name2 = class_name2->base(); 2057 2058 jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/'); 2059 jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/'); 2060 2061 if ((last_slash1 == NULL) || (last_slash2 == NULL)) { 2062 // One of the two doesn't have a package. Only return true 2063 // if the other one also doesn't have a package. 2064 return last_slash1 == last_slash2; 2065 } else { 2066 // Skip over '['s 2067 if (*name1 == '[') { 2068 do { 2069 name1++; 2070 } while (*name1 == '['); 2071 if (*name1 != 'L') { 2072 // Something is terribly wrong. Shouldn't be here. 2073 return false; 2074 } 2075 } 2076 if (*name2 == '[') { 2077 do { 2078 name2++; 2079 } while (*name2 == '['); 2080 if (*name2 != 'L') { 2081 // Something is terribly wrong. Shouldn't be here. 2082 return false; 2083 } 2084 } 2085 2086 // Check that package part is identical 2087 int length1 = last_slash1 - name1; 2088 int length2 = last_slash2 - name2; 2089 2090 return UTF8::equal(name1, length1, name2, length2); 2091 } 2092 } 2093 } 2094 2095 // Returns true iff super_method can be overridden by a method in targetclassname 2096 // See JSL 3rd edition 8.4.6.1 2097 // Assumes name-signature match 2098 // "this" is instanceKlass of super_method which must exist 2099 // note that the instanceKlass of the method in the targetclassname has not always been created yet 2100 bool instanceKlass::is_override(methodHandle super_method, Handle targetclassloader, symbolHandle targetclassname, TRAPS) { 2101 // Private methods can not be overridden 2102 if (super_method->is_private()) { 2103 return false; 2104 } 2105 // If super method is accessible, then override 2106 if ((super_method->is_protected()) || 2107 (super_method->is_public())) { 2108 return true; 2109 } 2110 // Package-private methods are not inherited outside of package 2111 assert(super_method->is_package_private(), "must be package private"); 2112 return(is_same_class_package(targetclassloader(), targetclassname())); 2113 } 2114 2115 /* defined for now in jvm.cpp, for historical reasons *-- 2116 klassOop instanceKlass::compute_enclosing_class_impl(instanceKlassHandle self, 2117 symbolOop& simple_name_result, TRAPS) { 2118 ... 2119 } 2120 */ 2121 2122 // tell if two classes have the same enclosing class (at package level) 2123 bool instanceKlass::is_same_package_member_impl(instanceKlassHandle class1, 2124 klassOop class2_oop, TRAPS) { 2125 if (class2_oop == class1->as_klassOop()) return true; 2126 if (!Klass::cast(class2_oop)->oop_is_instance()) return false; 2127 instanceKlassHandle class2(THREAD, class2_oop); 2128 2129 // must be in same package before we try anything else 2130 if (!class1->is_same_class_package(class2->class_loader(), class2->name())) 2131 return false; 2132 2133 // As long as there is an outer1.getEnclosingClass, 2134 // shift the search outward. 2135 instanceKlassHandle outer1 = class1; 2136 for (;;) { 2137 // As we walk along, look for equalities between outer1 and class2. 2138 // Eventually, the walks will terminate as outer1 stops 2139 // at the top-level class around the original class. 2140 bool ignore_inner_is_member; 2141 klassOop next = outer1->compute_enclosing_class(&ignore_inner_is_member, 2142 CHECK_false); 2143 if (next == NULL) break; 2144 if (next == class2()) return true; 2145 outer1 = instanceKlassHandle(THREAD, next); 2146 } 2147 2148 // Now do the same for class2. 2149 instanceKlassHandle outer2 = class2; 2150 for (;;) { 2151 bool ignore_inner_is_member; 2152 klassOop next = outer2->compute_enclosing_class(&ignore_inner_is_member, 2153 CHECK_false); 2154 if (next == NULL) break; 2155 // Might as well check the new outer against all available values. 2156 if (next == class1()) return true; 2157 if (next == outer1()) return true; 2158 outer2 = instanceKlassHandle(THREAD, next); 2159 } 2160 2161 // If by this point we have not found an equality between the 2162 // two classes, we know they are in separate package members. 2163 return false; 2164 } 2165 2166 2167 jint instanceKlass::compute_modifier_flags(TRAPS) const { 2168 klassOop k = as_klassOop(); 2169 jint access = access_flags().as_int(); 2170 2171 // But check if it happens to be member class. 2172 typeArrayOop inner_class_list = inner_classes(); 2173 int length = (inner_class_list == NULL) ? 0 : inner_class_list->length(); 2174 assert (length % instanceKlass::inner_class_next_offset == 0, "just checking"); 2175 if (length > 0) { 2176 typeArrayHandle inner_class_list_h(THREAD, inner_class_list); 2177 instanceKlassHandle ik(THREAD, k); 2178 for (int i = 0; i < length; i += instanceKlass::inner_class_next_offset) { 2179 int ioff = inner_class_list_h->ushort_at( 2180 i + instanceKlass::inner_class_inner_class_info_offset); 2181 2182 // Inner class attribute can be zero, skip it. 2183 // Strange but true: JVM spec. allows null inner class refs. 2184 if (ioff == 0) continue; 2185 2186 // only look at classes that are already loaded 2187 // since we are looking for the flags for our self. 2188 symbolOop inner_name = ik->constants()->klass_name_at(ioff); 2189 if ((ik->name() == inner_name)) { 2190 // This is really a member class. 2191 access = inner_class_list_h->ushort_at(i + instanceKlass::inner_class_access_flags_offset); 2192 break; 2193 } 2194 } 2195 } 2196 // Remember to strip ACC_SUPER bit 2197 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS; 2198 } 2199 2200 jint instanceKlass::jvmti_class_status() const { 2201 jint result = 0; 2202 2203 if (is_linked()) { 2204 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED; 2205 } 2206 2207 if (is_initialized()) { 2208 assert(is_linked(), "Class status is not consistent"); 2209 result |= JVMTI_CLASS_STATUS_INITIALIZED; 2210 } 2211 if (is_in_error_state()) { 2212 result |= JVMTI_CLASS_STATUS_ERROR; 2213 } 2214 return result; 2215 } 2216 2217 methodOop instanceKlass::method_at_itable(klassOop holder, int index, TRAPS) { 2218 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable(); 2219 int method_table_offset_in_words = ioe->offset()/wordSize; 2220 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words()) 2221 / itableOffsetEntry::size(); 2222 2223 for (int cnt = 0 ; ; cnt ++, ioe ++) { 2224 // If the interface isn't implemented by the receiver class, 2225 // the VM should throw IncompatibleClassChangeError. 2226 if (cnt >= nof_interfaces) { 2227 THROW_OOP_0(vmSymbols::java_lang_IncompatibleClassChangeError()); 2228 } 2229 2230 klassOop ik = ioe->interface_klass(); 2231 if (ik == holder) break; 2232 } 2233 2234 itableMethodEntry* ime = ioe->first_method_entry(as_klassOop()); 2235 methodOop m = ime[index].method(); 2236 if (m == NULL) { 2237 THROW_OOP_0(vmSymbols::java_lang_AbstractMethodError()); 2238 } 2239 return m; 2240 } 2241 2242 // On-stack replacement stuff 2243 void instanceKlass::add_osr_nmethod(nmethod* n) { 2244 // only one compilation can be active 2245 NEEDS_CLEANUP 2246 // This is a short non-blocking critical region, so the no safepoint check is ok. 2247 OsrList_lock->lock_without_safepoint_check(); 2248 assert(n->is_osr_method(), "wrong kind of nmethod"); 2249 n->set_osr_link(osr_nmethods_head()); 2250 set_osr_nmethods_head(n); 2251 // Raise the highest osr level if necessary 2252 if (TieredCompilation) { 2253 methodOop m = n->method(); 2254 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level())); 2255 } 2256 // Remember to unlock again 2257 OsrList_lock->unlock(); 2258 2259 // Get rid of the osr methods for the same bci that have lower levels. 2260 if (TieredCompilation) { 2261 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) { 2262 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true); 2263 if (inv != NULL && inv->is_in_use()) { 2264 inv->make_not_entrant(); 2265 } 2266 } 2267 } 2268 } 2269 2270 2271 void instanceKlass::remove_osr_nmethod(nmethod* n) { 2272 // This is a short non-blocking critical region, so the no safepoint check is ok. 2273 OsrList_lock->lock_without_safepoint_check(); 2274 assert(n->is_osr_method(), "wrong kind of nmethod"); 2275 nmethod* last = NULL; 2276 nmethod* cur = osr_nmethods_head(); 2277 int max_level = CompLevel_none; // Find the max comp level excluding n 2278 methodOop m = n->method(); 2279 // Search for match 2280 while(cur != NULL && cur != n) { 2281 if (TieredCompilation) { 2282 // Find max level before n 2283 max_level = MAX2(max_level, cur->comp_level()); 2284 } 2285 last = cur; 2286 cur = cur->osr_link(); 2287 } 2288 nmethod* next = NULL; 2289 if (cur == n) { 2290 next = cur->osr_link(); 2291 if (last == NULL) { 2292 // Remove first element 2293 set_osr_nmethods_head(next); 2294 } else { 2295 last->set_osr_link(next); 2296 } 2297 } 2298 n->set_osr_link(NULL); 2299 if (TieredCompilation) { 2300 cur = next; 2301 while (cur != NULL) { 2302 // Find max level after n 2303 max_level = MAX2(max_level, cur->comp_level()); 2304 cur = cur->osr_link(); 2305 } 2306 m->set_highest_osr_comp_level(max_level); 2307 } 2308 // Remember to unlock again 2309 OsrList_lock->unlock(); 2310 } 2311 2312 nmethod* instanceKlass::lookup_osr_nmethod(const methodOop m, int bci, int comp_level, bool match_level) const { 2313 // This is a short non-blocking critical region, so the no safepoint check is ok. 2314 OsrList_lock->lock_without_safepoint_check(); 2315 nmethod* osr = osr_nmethods_head(); 2316 nmethod* best = NULL; 2317 while (osr != NULL) { 2318 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain"); 2319 // There can be a time when a c1 osr method exists but we are waiting 2320 // for a c2 version. When c2 completes its osr nmethod we will trash 2321 // the c1 version and only be able to find the c2 version. However 2322 // while we overflow in the c1 code at back branches we don't want to 2323 // try and switch to the same code as we are already running 2324 2325 if (osr->method() == m && 2326 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) { 2327 if (match_level) { 2328 if (osr->comp_level() == comp_level) { 2329 // Found a match - return it. 2330 OsrList_lock->unlock(); 2331 return osr; 2332 } 2333 } else { 2334 if (best == NULL || (osr->comp_level() > best->comp_level())) { 2335 if (osr->comp_level() == CompLevel_highest_tier) { 2336 // Found the best possible - return it. 2337 OsrList_lock->unlock(); 2338 return osr; 2339 } 2340 best = osr; 2341 } 2342 } 2343 } 2344 osr = osr->osr_link(); 2345 } 2346 OsrList_lock->unlock(); 2347 if (best != NULL && best->comp_level() >= comp_level && match_level == false) { 2348 return best; 2349 } 2350 return NULL; 2351 } 2352 2353 // ----------------------------------------------------------------------------------------------------- 2354 #ifndef PRODUCT 2355 2356 // Printing 2357 2358 #define BULLET " - " 2359 2360 void FieldPrinter::do_field(fieldDescriptor* fd) { 2361 _st->print(BULLET); 2362 if (fd->is_static() || (_obj == NULL)) { 2363 fd->print_on(_st); 2364 _st->cr(); 2365 } else { 2366 fd->print_on_for(_st, _obj); 2367 _st->cr(); 2368 } 2369 } 2370 2371 2372 void instanceKlass::oop_print_on(oop obj, outputStream* st) { 2373 Klass::oop_print_on(obj, st); 2374 2375 if (as_klassOop() == SystemDictionary::String_klass()) { 2376 typeArrayOop value = java_lang_String::value(obj); 2377 juint offset = java_lang_String::offset(obj); 2378 juint length = java_lang_String::length(obj); 2379 if (value != NULL && 2380 value->is_typeArray() && 2381 offset <= (juint) value->length() && 2382 offset + length <= (juint) value->length()) { 2383 st->print(BULLET"string: "); 2384 Handle h_obj(obj); 2385 java_lang_String::print(h_obj, st); 2386 st->cr(); 2387 if (!WizardMode) return; // that is enough 2388 } 2389 } 2390 2391 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj)); 2392 FieldPrinter print_nonstatic_field(st, obj); 2393 do_nonstatic_fields(&print_nonstatic_field); 2394 2395 if (as_klassOop() == SystemDictionary::Class_klass()) { 2396 st->print(BULLET"signature: "); 2397 java_lang_Class::print_signature(obj, st); 2398 st->cr(); 2399 klassOop mirrored_klass = java_lang_Class::as_klassOop(obj); 2400 st->print(BULLET"fake entry for mirror: "); 2401 mirrored_klass->print_value_on(st); 2402 st->cr(); 2403 st->print(BULLET"fake entry resolved_constructor: "); 2404 methodOop ctor = java_lang_Class::resolved_constructor(obj); 2405 ctor->print_value_on(st); 2406 klassOop array_klass = java_lang_Class::array_klass(obj); 2407 st->cr(); 2408 st->print(BULLET"fake entry for array: "); 2409 array_klass->print_value_on(st); 2410 st->cr(); 2411 } else if (as_klassOop() == SystemDictionary::MethodType_klass()) { 2412 st->print(BULLET"signature: "); 2413 java_dyn_MethodType::print_signature(obj, st); 2414 st->cr(); 2415 } 2416 } 2417 2418 #endif //PRODUCT 2419 2420 void instanceKlass::oop_print_value_on(oop obj, outputStream* st) { 2421 st->print("a "); 2422 name()->print_value_on(st); 2423 obj->print_address_on(st); 2424 if (as_klassOop() == SystemDictionary::String_klass() 2425 && java_lang_String::value(obj) != NULL) { 2426 ResourceMark rm; 2427 int len = java_lang_String::length(obj); 2428 int plen = (len < 24 ? len : 12); 2429 char* str = java_lang_String::as_utf8_string(obj, 0, plen); 2430 st->print(" = \"%s\"", str); 2431 if (len > plen) 2432 st->print("...[%d]", len); 2433 } else if (as_klassOop() == SystemDictionary::Class_klass()) { 2434 klassOop k = java_lang_Class::as_klassOop(obj); 2435 st->print(" = "); 2436 if (k != NULL) { 2437 k->print_value_on(st); 2438 } else { 2439 const char* tname = type2name(java_lang_Class::primitive_type(obj)); 2440 st->print("%s", tname ? tname : "type?"); 2441 } 2442 } else if (as_klassOop() == SystemDictionary::MethodType_klass()) { 2443 st->print(" = "); 2444 java_dyn_MethodType::print_signature(obj, st); 2445 } else if (java_lang_boxing_object::is_instance(obj)) { 2446 st->print(" = "); 2447 java_lang_boxing_object::print(obj, st); 2448 } 2449 } 2450 2451 const char* instanceKlass::internal_name() const { 2452 return external_name(); 2453 } 2454 2455 // Verification 2456 2457 class VerifyFieldClosure: public OopClosure { 2458 protected: 2459 template <class T> void do_oop_work(T* p) { 2460 guarantee(Universe::heap()->is_in_closed_subset(p), "should be in heap"); 2461 oop obj = oopDesc::load_decode_heap_oop(p); 2462 if (!obj->is_oop_or_null()) { 2463 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj); 2464 Universe::print(); 2465 guarantee(false, "boom"); 2466 } 2467 } 2468 public: 2469 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); } 2470 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); } 2471 }; 2472 2473 void instanceKlass::oop_verify_on(oop obj, outputStream* st) { 2474 Klass::oop_verify_on(obj, st); 2475 VerifyFieldClosure blk; 2476 oop_oop_iterate(obj, &blk); 2477 } 2478 2479 #ifndef PRODUCT 2480 2481 void instanceKlass::verify_class_klass_nonstatic_oop_maps(klassOop k) { 2482 // This verification code is disabled. JDK_Version::is_gte_jdk14x_version() 2483 // cannot be called since this function is called before the VM is 2484 // able to determine what JDK version is running with. 2485 // The check below always is false since 1.4. 2486 return; 2487 2488 // This verification code temporarily disabled for the 1.4 2489 // reflection implementation since java.lang.Class now has 2490 // Java-level instance fields. Should rewrite this to handle this 2491 // case. 2492 if (!(JDK_Version::is_gte_jdk14x_version() && UseNewReflection)) { 2493 // Verify that java.lang.Class instances have a fake oop field added. 2494 instanceKlass* ik = instanceKlass::cast(k); 2495 2496 // Check that we have the right class 2497 static bool first_time = true; 2498 guarantee(k == SystemDictionary::Class_klass() && first_time, "Invalid verify of maps"); 2499 first_time = false; 2500 const int extra = java_lang_Class::number_of_fake_oop_fields; 2501 guarantee(ik->nonstatic_field_size() == extra, "just checking"); 2502 guarantee(ik->nonstatic_oop_map_count() == 1, "just checking"); 2503 guarantee(ik->size_helper() == align_object_size(instanceOopDesc::header_size() + extra), "just checking"); 2504 2505 // Check that the map is (2,extra) 2506 int offset = java_lang_Class::klass_offset; 2507 2508 OopMapBlock* map = ik->start_of_nonstatic_oop_maps(); 2509 guarantee(map->offset() == offset && map->count() == (unsigned int) extra, 2510 "sanity"); 2511 } 2512 } 2513 2514 #endif // ndef PRODUCT 2515 2516 // JNIid class for jfieldIDs only 2517 // Note to reviewers: 2518 // These JNI functions are just moved over to column 1 and not changed 2519 // in the compressed oops workspace. 2520 JNIid::JNIid(klassOop holder, int offset, JNIid* next) { 2521 _holder = holder; 2522 _offset = offset; 2523 _next = next; 2524 debug_only(_is_static_field_id = false;) 2525 } 2526 2527 2528 JNIid* JNIid::find(int offset) { 2529 JNIid* current = this; 2530 while (current != NULL) { 2531 if (current->offset() == offset) return current; 2532 current = current->next(); 2533 } 2534 return NULL; 2535 } 2536 2537 void JNIid::oops_do(OopClosure* f) { 2538 for (JNIid* cur = this; cur != NULL; cur = cur->next()) { 2539 f->do_oop(cur->holder_addr()); 2540 } 2541 } 2542 2543 void JNIid::deallocate(JNIid* current) { 2544 while (current != NULL) { 2545 JNIid* next = current->next(); 2546 delete current; 2547 current = next; 2548 } 2549 } 2550 2551 2552 void JNIid::verify(klassOop holder) { 2553 int first_field_offset = instanceKlass::cast(holder)->offset_of_static_fields(); 2554 int end_field_offset; 2555 end_field_offset = first_field_offset + (instanceKlass::cast(holder)->static_field_size() * wordSize); 2556 2557 JNIid* current = this; 2558 while (current != NULL) { 2559 guarantee(current->holder() == holder, "Invalid klass in JNIid"); 2560 #ifdef ASSERT 2561 int o = current->offset(); 2562 if (current->is_static_field_id()) { 2563 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid"); 2564 } 2565 #endif 2566 current = current->next(); 2567 } 2568 } 2569 2570 2571 #ifdef ASSERT 2572 void instanceKlass::set_init_state(ClassState state) { 2573 bool good_state = as_klassOop()->is_shared() ? (_init_state <= state) 2574 : (_init_state < state); 2575 assert(good_state || state == allocated, "illegal state transition"); 2576 _init_state = state; 2577 } 2578 #endif 2579 2580 2581 // RedefineClasses() support for previous versions: 2582 2583 // Add an information node that contains weak references to the 2584 // interesting parts of the previous version of the_class. 2585 // This is also where we clean out any unused weak references. 2586 // Note that while we delete nodes from the _previous_versions 2587 // array, we never delete the array itself until the klass is 2588 // unloaded. The has_been_redefined() query depends on that fact. 2589 // 2590 void instanceKlass::add_previous_version(instanceKlassHandle ikh, 2591 BitMap* emcp_methods, int emcp_method_count) { 2592 assert(Thread::current()->is_VM_thread(), 2593 "only VMThread can add previous versions"); 2594 2595 if (_previous_versions == NULL) { 2596 // This is the first previous version so make some space. 2597 // Start with 2 elements under the assumption that the class 2598 // won't be redefined much. 2599 _previous_versions = new (ResourceObj::C_HEAP) 2600 GrowableArray<PreviousVersionNode *>(2, true); 2601 } 2602 2603 // RC_TRACE macro has an embedded ResourceMark 2604 RC_TRACE(0x00000100, ("adding previous version ref for %s @%d, EMCP_cnt=%d", 2605 ikh->external_name(), _previous_versions->length(), emcp_method_count)); 2606 constantPoolHandle cp_h(ikh->constants()); 2607 jobject cp_ref; 2608 if (cp_h->is_shared()) { 2609 // a shared ConstantPool requires a regular reference; a weak 2610 // reference would be collectible 2611 cp_ref = JNIHandles::make_global(cp_h); 2612 } else { 2613 cp_ref = JNIHandles::make_weak_global(cp_h); 2614 } 2615 PreviousVersionNode * pv_node = NULL; 2616 objArrayOop old_methods = ikh->methods(); 2617 2618 if (emcp_method_count == 0) { 2619 // non-shared ConstantPool gets a weak reference 2620 pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), NULL); 2621 RC_TRACE(0x00000400, 2622 ("add: all methods are obsolete; flushing any EMCP weak refs")); 2623 } else { 2624 int local_count = 0; 2625 GrowableArray<jweak>* method_refs = new (ResourceObj::C_HEAP) 2626 GrowableArray<jweak>(emcp_method_count, true); 2627 for (int i = 0; i < old_methods->length(); i++) { 2628 if (emcp_methods->at(i)) { 2629 // this old method is EMCP so save a weak ref 2630 methodOop old_method = (methodOop) old_methods->obj_at(i); 2631 methodHandle old_method_h(old_method); 2632 jweak method_ref = JNIHandles::make_weak_global(old_method_h); 2633 method_refs->append(method_ref); 2634 if (++local_count >= emcp_method_count) { 2635 // no more EMCP methods so bail out now 2636 break; 2637 } 2638 } 2639 } 2640 // non-shared ConstantPool gets a weak reference 2641 pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), method_refs); 2642 } 2643 2644 _previous_versions->append(pv_node); 2645 2646 // Using weak references allows the interesting parts of previous 2647 // classes to be GC'ed when they are no longer needed. Since the 2648 // caller is the VMThread and we are at a safepoint, this is a good 2649 // time to clear out unused weak references. 2650 2651 RC_TRACE(0x00000400, ("add: previous version length=%d", 2652 _previous_versions->length())); 2653 2654 // skip the last entry since we just added it 2655 for (int i = _previous_versions->length() - 2; i >= 0; i--) { 2656 // check the previous versions array for a GC'ed weak refs 2657 pv_node = _previous_versions->at(i); 2658 cp_ref = pv_node->prev_constant_pool(); 2659 assert(cp_ref != NULL, "cp ref was unexpectedly cleared"); 2660 if (cp_ref == NULL) { 2661 delete pv_node; 2662 _previous_versions->remove_at(i); 2663 // Since we are traversing the array backwards, we don't have to 2664 // do anything special with the index. 2665 continue; // robustness 2666 } 2667 2668 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref); 2669 if (cp == NULL) { 2670 // this entry has been GC'ed so remove it 2671 delete pv_node; 2672 _previous_versions->remove_at(i); 2673 // Since we are traversing the array backwards, we don't have to 2674 // do anything special with the index. 2675 continue; 2676 } else { 2677 RC_TRACE(0x00000400, ("add: previous version @%d is alive", i)); 2678 } 2679 2680 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods(); 2681 if (method_refs != NULL) { 2682 RC_TRACE(0x00000400, ("add: previous methods length=%d", 2683 method_refs->length())); 2684 for (int j = method_refs->length() - 1; j >= 0; j--) { 2685 jweak method_ref = method_refs->at(j); 2686 assert(method_ref != NULL, "weak method ref was unexpectedly cleared"); 2687 if (method_ref == NULL) { 2688 method_refs->remove_at(j); 2689 // Since we are traversing the array backwards, we don't have to 2690 // do anything special with the index. 2691 continue; // robustness 2692 } 2693 2694 methodOop method = (methodOop)JNIHandles::resolve(method_ref); 2695 if (method == NULL || emcp_method_count == 0) { 2696 // This method entry has been GC'ed or the current 2697 // RedefineClasses() call has made all methods obsolete 2698 // so remove it. 2699 JNIHandles::destroy_weak_global(method_ref); 2700 method_refs->remove_at(j); 2701 } else { 2702 // RC_TRACE macro has an embedded ResourceMark 2703 RC_TRACE(0x00000400, 2704 ("add: %s(%s): previous method @%d in version @%d is alive", 2705 method->name()->as_C_string(), method->signature()->as_C_string(), 2706 j, i)); 2707 } 2708 } 2709 } 2710 } 2711 2712 int obsolete_method_count = old_methods->length() - emcp_method_count; 2713 2714 if (emcp_method_count != 0 && obsolete_method_count != 0 && 2715 _previous_versions->length() > 1) { 2716 // We have a mix of obsolete and EMCP methods. If there is more 2717 // than the previous version that we just added, then we have to 2718 // clear out any matching EMCP method entries the hard way. 2719 int local_count = 0; 2720 for (int i = 0; i < old_methods->length(); i++) { 2721 if (!emcp_methods->at(i)) { 2722 // only obsolete methods are interesting 2723 methodOop old_method = (methodOop) old_methods->obj_at(i); 2724 symbolOop m_name = old_method->name(); 2725 symbolOop m_signature = old_method->signature(); 2726 2727 // skip the last entry since we just added it 2728 for (int j = _previous_versions->length() - 2; j >= 0; j--) { 2729 // check the previous versions array for a GC'ed weak refs 2730 pv_node = _previous_versions->at(j); 2731 cp_ref = pv_node->prev_constant_pool(); 2732 assert(cp_ref != NULL, "cp ref was unexpectedly cleared"); 2733 if (cp_ref == NULL) { 2734 delete pv_node; 2735 _previous_versions->remove_at(j); 2736 // Since we are traversing the array backwards, we don't have to 2737 // do anything special with the index. 2738 continue; // robustness 2739 } 2740 2741 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref); 2742 if (cp == NULL) { 2743 // this entry has been GC'ed so remove it 2744 delete pv_node; 2745 _previous_versions->remove_at(j); 2746 // Since we are traversing the array backwards, we don't have to 2747 // do anything special with the index. 2748 continue; 2749 } 2750 2751 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods(); 2752 if (method_refs == NULL) { 2753 // We have run into a PreviousVersion generation where 2754 // all methods were made obsolete during that generation's 2755 // RedefineClasses() operation. At the time of that 2756 // operation, all EMCP methods were flushed so we don't 2757 // have to go back any further. 2758 // 2759 // A NULL method_refs is different than an empty method_refs. 2760 // We cannot infer any optimizations about older generations 2761 // from an empty method_refs for the current generation. 2762 break; 2763 } 2764 2765 for (int k = method_refs->length() - 1; k >= 0; k--) { 2766 jweak method_ref = method_refs->at(k); 2767 assert(method_ref != NULL, 2768 "weak method ref was unexpectedly cleared"); 2769 if (method_ref == NULL) { 2770 method_refs->remove_at(k); 2771 // Since we are traversing the array backwards, we don't 2772 // have to do anything special with the index. 2773 continue; // robustness 2774 } 2775 2776 methodOop method = (methodOop)JNIHandles::resolve(method_ref); 2777 if (method == NULL) { 2778 // this method entry has been GC'ed so skip it 2779 JNIHandles::destroy_weak_global(method_ref); 2780 method_refs->remove_at(k); 2781 continue; 2782 } 2783 2784 if (method->name() == m_name && 2785 method->signature() == m_signature) { 2786 // The current RedefineClasses() call has made all EMCP 2787 // versions of this method obsolete so mark it as obsolete 2788 // and remove the weak ref. 2789 RC_TRACE(0x00000400, 2790 ("add: %s(%s): flush obsolete method @%d in version @%d", 2791 m_name->as_C_string(), m_signature->as_C_string(), k, j)); 2792 2793 method->set_is_obsolete(); 2794 JNIHandles::destroy_weak_global(method_ref); 2795 method_refs->remove_at(k); 2796 break; 2797 } 2798 } 2799 2800 // The previous loop may not find a matching EMCP method, but 2801 // that doesn't mean that we can optimize and not go any 2802 // further back in the PreviousVersion generations. The EMCP 2803 // method for this generation could have already been GC'ed, 2804 // but there still may be an older EMCP method that has not 2805 // been GC'ed. 2806 } 2807 2808 if (++local_count >= obsolete_method_count) { 2809 // no more obsolete methods so bail out now 2810 break; 2811 } 2812 } 2813 } 2814 } 2815 } // end add_previous_version() 2816 2817 2818 // Determine if instanceKlass has a previous version. 2819 bool instanceKlass::has_previous_version() const { 2820 if (_previous_versions == NULL) { 2821 // no previous versions array so answer is easy 2822 return false; 2823 } 2824 2825 for (int i = _previous_versions->length() - 1; i >= 0; i--) { 2826 // Check the previous versions array for an info node that hasn't 2827 // been GC'ed 2828 PreviousVersionNode * pv_node = _previous_versions->at(i); 2829 2830 jobject cp_ref = pv_node->prev_constant_pool(); 2831 assert(cp_ref != NULL, "cp reference was unexpectedly cleared"); 2832 if (cp_ref == NULL) { 2833 continue; // robustness 2834 } 2835 2836 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref); 2837 if (cp != NULL) { 2838 // we have at least one previous version 2839 return true; 2840 } 2841 2842 // We don't have to check the method refs. If the constant pool has 2843 // been GC'ed then so have the methods. 2844 } 2845 2846 // all of the underlying nodes' info has been GC'ed 2847 return false; 2848 } // end has_previous_version() 2849 2850 methodOop instanceKlass::method_with_idnum(int idnum) { 2851 methodOop m = NULL; 2852 if (idnum < methods()->length()) { 2853 m = (methodOop) methods()->obj_at(idnum); 2854 } 2855 if (m == NULL || m->method_idnum() != idnum) { 2856 for (int index = 0; index < methods()->length(); ++index) { 2857 m = (methodOop) methods()->obj_at(index); 2858 if (m->method_idnum() == idnum) { 2859 return m; 2860 } 2861 } 2862 } 2863 return m; 2864 } 2865 2866 2867 // Set the annotation at 'idnum' to 'anno'. 2868 // We don't want to create or extend the array if 'anno' is NULL, since that is the 2869 // default value. However, if the array exists and is long enough, we must set NULL values. 2870 void instanceKlass::set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p) { 2871 objArrayOop md = *md_p; 2872 if (md != NULL && md->length() > idnum) { 2873 md->obj_at_put(idnum, anno); 2874 } else if (anno != NULL) { 2875 // create the array 2876 int length = MAX2(idnum+1, (int)_idnum_allocated_count); 2877 md = oopFactory::new_system_objArray(length, Thread::current()); 2878 if (*md_p != NULL) { 2879 // copy the existing entries 2880 for (int index = 0; index < (*md_p)->length(); index++) { 2881 md->obj_at_put(index, (*md_p)->obj_at(index)); 2882 } 2883 } 2884 set_annotations(md, md_p); 2885 md->obj_at_put(idnum, anno); 2886 } // if no array and idnum isn't included there is nothing to do 2887 } 2888 2889 // Construct a PreviousVersionNode entry for the array hung off 2890 // the instanceKlass. 2891 PreviousVersionNode::PreviousVersionNode(jobject prev_constant_pool, 2892 bool prev_cp_is_weak, GrowableArray<jweak>* prev_EMCP_methods) { 2893 2894 _prev_constant_pool = prev_constant_pool; 2895 _prev_cp_is_weak = prev_cp_is_weak; 2896 _prev_EMCP_methods = prev_EMCP_methods; 2897 } 2898 2899 2900 // Destroy a PreviousVersionNode 2901 PreviousVersionNode::~PreviousVersionNode() { 2902 if (_prev_constant_pool != NULL) { 2903 if (_prev_cp_is_weak) { 2904 JNIHandles::destroy_weak_global(_prev_constant_pool); 2905 } else { 2906 JNIHandles::destroy_global(_prev_constant_pool); 2907 } 2908 } 2909 2910 if (_prev_EMCP_methods != NULL) { 2911 for (int i = _prev_EMCP_methods->length() - 1; i >= 0; i--) { 2912 jweak method_ref = _prev_EMCP_methods->at(i); 2913 if (method_ref != NULL) { 2914 JNIHandles::destroy_weak_global(method_ref); 2915 } 2916 } 2917 delete _prev_EMCP_methods; 2918 } 2919 } 2920 2921 2922 // Construct a PreviousVersionInfo entry 2923 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) { 2924 _prev_constant_pool_handle = constantPoolHandle(); // NULL handle 2925 _prev_EMCP_method_handles = NULL; 2926 2927 jobject cp_ref = pv_node->prev_constant_pool(); 2928 assert(cp_ref != NULL, "constant pool ref was unexpectedly cleared"); 2929 if (cp_ref == NULL) { 2930 return; // robustness 2931 } 2932 2933 constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref); 2934 if (cp == NULL) { 2935 // Weak reference has been GC'ed. Since the constant pool has been 2936 // GC'ed, the methods have also been GC'ed. 2937 return; 2938 } 2939 2940 // make the constantPoolOop safe to return 2941 _prev_constant_pool_handle = constantPoolHandle(cp); 2942 2943 GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods(); 2944 if (method_refs == NULL) { 2945 // the instanceKlass did not have any EMCP methods 2946 return; 2947 } 2948 2949 _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10); 2950 2951 int n_methods = method_refs->length(); 2952 for (int i = 0; i < n_methods; i++) { 2953 jweak method_ref = method_refs->at(i); 2954 assert(method_ref != NULL, "weak method ref was unexpectedly cleared"); 2955 if (method_ref == NULL) { 2956 continue; // robustness 2957 } 2958 2959 methodOop method = (methodOop)JNIHandles::resolve(method_ref); 2960 if (method == NULL) { 2961 // this entry has been GC'ed so skip it 2962 continue; 2963 } 2964 2965 // make the methodOop safe to return 2966 _prev_EMCP_method_handles->append(methodHandle(method)); 2967 } 2968 } 2969 2970 2971 // Destroy a PreviousVersionInfo 2972 PreviousVersionInfo::~PreviousVersionInfo() { 2973 // Since _prev_EMCP_method_handles is not C-heap allocated, we 2974 // don't have to delete it. 2975 } 2976 2977 2978 // Construct a helper for walking the previous versions array 2979 PreviousVersionWalker::PreviousVersionWalker(instanceKlass *ik) { 2980 _previous_versions = ik->previous_versions(); 2981 _current_index = 0; 2982 // _hm needs no initialization 2983 _current_p = NULL; 2984 } 2985 2986 2987 // Destroy a PreviousVersionWalker 2988 PreviousVersionWalker::~PreviousVersionWalker() { 2989 // Delete the current info just in case the caller didn't walk to 2990 // the end of the previous versions list. No harm if _current_p is 2991 // already NULL. 2992 delete _current_p; 2993 2994 // When _hm is destroyed, all the Handles returned in 2995 // PreviousVersionInfo objects will be destroyed. 2996 // Also, after this destructor is finished it will be 2997 // safe to delete the GrowableArray allocated in the 2998 // PreviousVersionInfo objects. 2999 } 3000 3001 3002 // Return the interesting information for the next previous version 3003 // of the klass. Returns NULL if there are no more previous versions. 3004 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() { 3005 if (_previous_versions == NULL) { 3006 // no previous versions so nothing to return 3007 return NULL; 3008 } 3009 3010 delete _current_p; // cleanup the previous info for the caller 3011 _current_p = NULL; // reset to NULL so we don't delete same object twice 3012 3013 int length = _previous_versions->length(); 3014 3015 while (_current_index < length) { 3016 PreviousVersionNode * pv_node = _previous_versions->at(_current_index++); 3017 PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP) 3018 PreviousVersionInfo(pv_node); 3019 3020 constantPoolHandle cp_h = pv_info->prev_constant_pool_handle(); 3021 if (cp_h.is_null()) { 3022 delete pv_info; 3023 3024 // The underlying node's info has been GC'ed so try the next one. 3025 // We don't have to check the methods. If the constant pool has 3026 // GC'ed then so have the methods. 3027 continue; 3028 } 3029 3030 // Found a node with non GC'ed info so return it. The caller will 3031 // need to delete pv_info when they are done with it. 3032 _current_p = pv_info; 3033 return pv_info; 3034 } 3035 3036 // all of the underlying nodes' info has been GC'ed 3037 return NULL; 3038 } // end next_previous_version()