1 /*
   2  * Copyright (c) 1997, 2013, 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/heapInspection.hpp"
  38 #include "memory/metadataFactory.hpp"
  39 #include "memory/oopFactory.hpp"
  40 #include "oops/fieldStreams.hpp"
  41 #include "oops/instanceClassLoaderKlass.hpp"
  42 #include "oops/instanceKlass.hpp"
  43 #include "oops/instanceMirrorKlass.hpp"
  44 #include "oops/instanceOop.hpp"
  45 #include "oops/klass.inline.hpp"
  46 #include "oops/method.hpp"
  47 #include "oops/oop.inline.hpp"
  48 #include "oops/symbol.hpp"
  49 #include "prims/jvmtiExport.hpp"
  50 #include "prims/jvmtiRedefineClassesTrace.hpp"
  51 #include "prims/methodComparator.hpp"
  52 #include "runtime/fieldDescriptor.hpp"
  53 #include "runtime/handles.inline.hpp"
  54 #include "runtime/javaCalls.hpp"
  55 #include "runtime/mutexLocker.hpp"
  56 #include "runtime/thread.inline.hpp"
  57 #include "services/threadService.hpp"
  58 #include "utilities/dtrace.hpp"
  59 #include "utilities/macros.hpp"
  60 #if INCLUDE_ALL_GCS
  61 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
  62 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  63 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
  64 #include "gc_implementation/g1/g1RemSet.inline.hpp"
  65 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
  66 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
  67 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.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 // INCLUDE_ALL_GCS
  72 #ifdef COMPILER1
  73 #include "c1/c1_Compiler.hpp"
  74 #endif
  75 
  76 #ifdef DTRACE_ENABLED
  77 
  78 #ifndef USDT2
  79 
  80 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
  81   char*, intptr_t, oop, intptr_t);
  82 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
  83   char*, intptr_t, oop, intptr_t, int);
  84 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
  85   char*, intptr_t, oop, intptr_t, int);
  86 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
  87   char*, intptr_t, oop, intptr_t, int);
  88 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
  89   char*, intptr_t, oop, intptr_t, int);
  90 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
  91   char*, intptr_t, oop, intptr_t, int);
  92 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
  93   char*, intptr_t, oop, intptr_t, int);
  94 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
  95   char*, intptr_t, oop, intptr_t, int);
  96 
  97 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
  98   {                                                              \
  99     char* data = NULL;                                           \
 100     int len = 0;                                                 \
 101     Symbol* name = (clss)->name();                               \
 102     if (name != NULL) {                                          \
 103       data = (char*)name->bytes();                               \
 104       len = name->utf8_length();                                 \
 105     }                                                            \
 106     HS_DTRACE_PROBE4(hotspot, class__initialization__##type,     \
 107       data, len, (clss)->class_loader(), thread_type);           \
 108   }
 109 
 110 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
 111   {                                                              \
 112     char* data = NULL;                                           \
 113     int len = 0;                                                 \
 114     Symbol* name = (clss)->name();                               \
 115     if (name != NULL) {                                          \
 116       data = (char*)name->bytes();                               \
 117       len = name->utf8_length();                                 \
 118     }                                                            \
 119     HS_DTRACE_PROBE5(hotspot, class__initialization__##type,     \
 120       data, len, (clss)->class_loader(), thread_type, wait);     \
 121   }
 122 #else /* USDT2 */
 123 
 124 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
 125 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
 126 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
 127 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
 128 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
 129 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
 130 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
 131 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
 132 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
 133   {                                                              \
 134     char* data = NULL;                                           \
 135     int len = 0;                                                 \
 136     Symbol* name = (clss)->name();                               \
 137     if (name != NULL) {                                          \
 138       data = (char*)name->bytes();                               \
 139       len = name->utf8_length();                                 \
 140     }                                                            \
 141     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 142       data, len, (clss)->class_loader(), thread_type);           \
 143   }
 144 
 145 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
 146   {                                                              \
 147     char* data = NULL;                                           \
 148     int len = 0;                                                 \
 149     Symbol* name = (clss)->name();                               \
 150     if (name != NULL) {                                          \
 151       data = (char*)name->bytes();                               \
 152       len = name->utf8_length();                                 \
 153     }                                                            \
 154     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 155       data, len, (clss)->class_loader(), thread_type, wait);     \
 156   }
 157 #endif /* USDT2 */
 158 
 159 #else //  ndef DTRACE_ENABLED
 160 
 161 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
 162 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
 163 
 164 #endif //  ndef DTRACE_ENABLED
 165 
 166 volatile int InstanceKlass::_total_instanceKlass_count = 0;
 167 
 168 Klass* InstanceKlass::allocate_instance_klass(ClassLoaderData* loader_data,
 169                                                 int vtable_len,
 170                                                 int itable_len,
 171                                                 int static_field_size,
 172                                                 int nonstatic_oop_map_size,
 173                                                 ReferenceType rt,
 174                                                 AccessFlags access_flags,
 175                                                 Symbol* name,
 176                                               Klass* super_klass,
 177                                                 KlassHandle host_klass,
 178                                                 TRAPS) {
 179 
 180   int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
 181                                  access_flags.is_interface(),
 182                                  !host_klass.is_null());
 183 
 184   // Allocation
 185   InstanceKlass* ik;
 186   if (rt == REF_NONE) {
 187     if (name == vmSymbols::java_lang_Class()) {
 188       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
 189         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 190         access_flags, !host_klass.is_null());
 191     } else if (name == vmSymbols::java_lang_ClassLoader() ||
 192           (SystemDictionary::ClassLoader_klass_loaded() &&
 193           super_klass != NULL &&
 194           super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
 195       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
 196         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 197         access_flags, !host_klass.is_null());
 198     } else {
 199       // normal class
 200       ik = new (loader_data, size, THREAD) InstanceKlass(
 201         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 202         access_flags, !host_klass.is_null());
 203     }
 204   } else {
 205     // reference klass
 206     ik = new (loader_data, size, THREAD) InstanceRefKlass(
 207         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 208         access_flags, !host_klass.is_null());
 209   }
 210 
 211   Atomic::inc(&_total_instanceKlass_count);
 212   return ik;
 213 }
 214 
 215 InstanceKlass::InstanceKlass(int vtable_len,
 216                              int itable_len,
 217                              int static_field_size,
 218                              int nonstatic_oop_map_size,
 219                              ReferenceType rt,
 220                              AccessFlags access_flags,
 221                              bool is_anonymous) {
 222   No_Safepoint_Verifier no_safepoint; // until k becomes parsable
 223 
 224   int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
 225                                  access_flags.is_interface(), is_anonymous);
 226 
 227   // The sizes of these these three variables are used for determining the
 228   // size of the instanceKlassOop. It is critical that these are set to the right
 229   // sizes before the first GC, i.e., when we allocate the mirror.
 230   this->set_vtable_length(vtable_len);
 231   this->set_itable_length(itable_len);
 232   this->set_static_field_size(static_field_size);
 233   this->set_nonstatic_oop_map_size(nonstatic_oop_map_size);
 234   this->set_access_flags(access_flags);
 235   this->set_is_anonymous(is_anonymous);
 236   assert(this->size() == size, "wrong size for object");
 237 
 238   this->set_array_klasses(NULL);
 239   this->set_methods(NULL);
 240   this->set_method_ordering(NULL);
 241   this->set_local_interfaces(NULL);
 242   this->set_transitive_interfaces(NULL);
 243   this->init_implementor();
 244   this->set_fields(NULL, 0);
 245   this->set_constants(NULL);
 246   this->set_class_loader_data(NULL);
 247   this->set_protection_domain(NULL);
 248   this->set_signers(NULL);
 249   this->set_source_file_name(NULL);
 250   this->set_source_debug_extension(NULL, 0);
 251   this->set_array_name(NULL);
 252   this->set_inner_classes(NULL);
 253   this->set_static_oop_field_count(0);
 254   this->set_nonstatic_field_size(0);
 255   this->set_is_marked_dependent(false);
 256   this->set_init_state(InstanceKlass::allocated);
 257   this->set_init_thread(NULL);
 258   this->set_init_lock(NULL);
 259   this->set_reference_type(rt);
 260   this->set_oop_map_cache(NULL);
 261   this->set_jni_ids(NULL);
 262   this->set_osr_nmethods_head(NULL);
 263   this->set_breakpoints(NULL);
 264   this->init_previous_versions();
 265   this->set_generic_signature(NULL);
 266   this->release_set_methods_jmethod_ids(NULL);
 267   this->release_set_methods_cached_itable_indices(NULL);
 268   this->set_annotations(NULL);
 269   this->set_jvmti_cached_class_field_map(NULL);
 270   this->set_initial_method_idnum(0);
 271 
 272   // initialize the non-header words to zero
 273   intptr_t* p = (intptr_t*)this;
 274   for (int index = InstanceKlass::header_size(); index < size; index++) {
 275     p[index] = NULL_WORD;
 276   }
 277 
 278   // Set temporary value until parseClassFile updates it with the real instance
 279   // size.
 280   this->set_layout_helper(Klass::instance_layout_helper(0, true));
 281 }
 282 
 283 
 284 // This function deallocates the metadata and C heap pointers that the
 285 // InstanceKlass points to.
 286 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 287 
 288   // Orphan the mirror first, CMS thinks it's still live.
 289   java_lang_Class::set_klass(java_mirror(), NULL);
 290 
 291   // Need to take this class off the class loader data list.
 292   loader_data->remove_class(this);
 293 
 294   // The array_klass for this class is created later, after error handling.
 295   // For class redefinition, we keep the original class so this scratch class
 296   // doesn't have an array class.  Either way, assert that there is nothing
 297   // to deallocate.
 298   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
 299 
 300   // Release C heap allocated data that this might point to, which includes
 301   // reference counting symbol names.
 302   release_C_heap_structures();
 303 
 304   Array<Method*>* ms = methods();
 305   if (ms != Universe::the_empty_method_array()) {
 306     for (int i = 0; i <= methods()->length() -1 ; i++) {
 307       Method* method = methods()->at(i);
 308       // Only want to delete methods that are not executing for RedefineClasses.
 309       // The previous version will point to them so they're not totally dangling
 310       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 311       MetadataFactory::free_metadata(loader_data, method);
 312     }
 313     MetadataFactory::free_array<Method*>(loader_data, methods());
 314   }
 315   set_methods(NULL);
 316 
 317   if (method_ordering() != Universe::the_empty_int_array()) {
 318     MetadataFactory::free_array<int>(loader_data, method_ordering());
 319   }
 320   set_method_ordering(NULL);
 321 
 322   // This array is in Klass, but remove it with the InstanceKlass since
 323   // this place would be the only caller and it can share memory with transitive
 324   // interfaces.
 325   if (secondary_supers() != Universe::the_empty_klass_array() &&
 326       secondary_supers() != transitive_interfaces()) {
 327     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 328   }
 329   set_secondary_supers(NULL);
 330 
 331   // Only deallocate transitive interfaces if not empty, same as super class
 332   // or same as local interfaces.   See code in parseClassFile.
 333   Array<Klass*>* ti = transitive_interfaces();
 334   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces()) {
 335     // check that the interfaces don't come from super class
 336     Array<Klass*>* sti = (super() == NULL) ? NULL :
 337        InstanceKlass::cast(super())->transitive_interfaces();
 338     if (ti != sti) {
 339       MetadataFactory::free_array<Klass*>(loader_data, ti);
 340     }
 341   }
 342   set_transitive_interfaces(NULL);
 343 
 344   // local interfaces can be empty
 345   Array<Klass*>* li = local_interfaces();
 346   if (li != Universe::the_empty_klass_array()) {
 347     MetadataFactory::free_array<Klass*>(loader_data, li);
 348   }
 349   set_local_interfaces(NULL);
 350 
 351   MetadataFactory::free_array<jushort>(loader_data, fields());
 352   set_fields(NULL, 0);
 353 
 354   // If a method from a redefined class is using this constant pool, don't
 355   // delete it, yet.  The new class's previous version will point to this.
 356   assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 357   MetadataFactory::free_metadata(loader_data, constants());
 358   set_constants(NULL);
 359 
 360   if (inner_classes() != Universe::the_empty_short_array()) {
 361     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 362   }
 363   set_inner_classes(NULL);
 364 
 365   // Null out Java heap objects, although these won't be walked to keep
 366   // alive once this InstanceKlass is deallocated.
 367   set_protection_domain(NULL);
 368   set_signers(NULL);
 369   set_init_lock(NULL);
 370 
 371   // We should deallocate the Annotations instance
 372   MetadataFactory::free_metadata(loader_data, annotations());
 373   set_annotations(NULL);
 374 }
 375 
 376 volatile oop InstanceKlass::init_lock() const {
 377   volatile oop lock = _init_lock;  // read once
 378   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
 379          "only fully initialized state can have a null lock");
 380   return lock;
 381 }
 382 
 383 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 384 // threads to get this lock will see a null lock and will not lock.
 385 // That's okay because they all check for initialized state after getting
 386 // the lock and return.
 387 void InstanceKlass::fence_and_clear_init_lock() {
 388   // make sure previous stores are all done, notably the init_state.
 389   OrderAccess::storestore();
 390   klass_oop_store(&_init_lock, NULL);
 391   assert(!is_not_initialized(), "class must be initialized now");
 392 }
 393 
 394 
 395 bool InstanceKlass::should_be_initialized() const {
 396   return !is_initialized();
 397 }
 398 
 399 klassVtable* InstanceKlass::vtable() const {
 400   return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
 401 }
 402 
 403 klassItable* InstanceKlass::itable() const {
 404   return new klassItable(instanceKlassHandle(this));
 405 }
 406 
 407 void InstanceKlass::eager_initialize(Thread *thread) {
 408   if (!EagerInitialization) return;
 409 
 410   if (this->is_not_initialized()) {
 411     // abort if the the class has a class initializer
 412     if (this->class_initializer() != NULL) return;
 413 
 414     // abort if it is java.lang.Object (initialization is handled in genesis)
 415     Klass* super = this->super();
 416     if (super == NULL) return;
 417 
 418     // abort if the super class should be initialized
 419     if (!InstanceKlass::cast(super)->is_initialized()) return;
 420 
 421     // call body to expose the this pointer
 422     instanceKlassHandle this_oop(thread, this);
 423     eager_initialize_impl(this_oop);
 424   }
 425 }
 426 
 427 
 428 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
 429   EXCEPTION_MARK;
 430   volatile oop init_lock = this_oop->init_lock();
 431   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 432 
 433   // abort if someone beat us to the initialization
 434   if (!this_oop->is_not_initialized()) return;  // note: not equivalent to is_initialized()
 435 
 436   ClassState old_state = this_oop->init_state();
 437   link_class_impl(this_oop, true, THREAD);
 438   if (HAS_PENDING_EXCEPTION) {
 439     CLEAR_PENDING_EXCEPTION;
 440     // Abort if linking the class throws an exception.
 441 
 442     // Use a test to avoid redundantly resetting the state if there's
 443     // no change.  Set_init_state() asserts that state changes make
 444     // progress, whereas here we might just be spinning in place.
 445     if( old_state != this_oop->_init_state )
 446       this_oop->set_init_state (old_state);
 447   } else {
 448     // linking successfull, mark class as initialized
 449     this_oop->set_init_state (fully_initialized);
 450     this_oop->fence_and_clear_init_lock();
 451     // trace
 452     if (TraceClassInitialization) {
 453       ResourceMark rm(THREAD);
 454       tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
 455     }
 456   }
 457 }
 458 
 459 
 460 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 461 // process. The step comments refers to the procedure described in that section.
 462 // Note: implementation moved to static method to expose the this pointer.
 463 void InstanceKlass::initialize(TRAPS) {
 464   if (this->should_be_initialized()) {
 465     HandleMark hm(THREAD);
 466     instanceKlassHandle this_oop(THREAD, this);
 467     initialize_impl(this_oop, CHECK);
 468     // Note: at this point the class may be initialized
 469     //       OR it may be in the state of being initialized
 470     //       in case of recursive initialization!
 471   } else {
 472     assert(is_initialized(), "sanity check");
 473   }
 474 }
 475 
 476 
 477 bool InstanceKlass::verify_code(
 478     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
 479   // 1) Verify the bytecodes
 480   Verifier::Mode mode =
 481     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
 482   return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
 483 }
 484 
 485 
 486 // Used exclusively by the shared spaces dump mechanism to prevent
 487 // classes mapped into the shared regions in new VMs from appearing linked.
 488 
 489 void InstanceKlass::unlink_class() {
 490   assert(is_linked(), "must be linked");
 491   _init_state = loaded;
 492 }
 493 
 494 void InstanceKlass::link_class(TRAPS) {
 495   assert(is_loaded(), "must be loaded");
 496   if (!is_linked()) {
 497     HandleMark hm(THREAD);
 498     instanceKlassHandle this_oop(THREAD, this);
 499     link_class_impl(this_oop, true, CHECK);
 500   }
 501 }
 502 
 503 // Called to verify that a class can link during initialization, without
 504 // throwing a VerifyError.
 505 bool InstanceKlass::link_class_or_fail(TRAPS) {
 506   assert(is_loaded(), "must be loaded");
 507   if (!is_linked()) {
 508     HandleMark hm(THREAD);
 509     instanceKlassHandle this_oop(THREAD, this);
 510     link_class_impl(this_oop, false, CHECK_false);
 511   }
 512   return is_linked();
 513 }
 514 
 515 bool InstanceKlass::link_class_impl(
 516     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
 517   // check for error state
 518   if (this_oop->is_in_error_state()) {
 519     ResourceMark rm(THREAD);
 520     THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
 521                this_oop->external_name(), false);
 522   }
 523   // return if already verified
 524   if (this_oop->is_linked()) {
 525     return true;
 526   }
 527 
 528   // Timing
 529   // timer handles recursion
 530   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 531   JavaThread* jt = (JavaThread*)THREAD;
 532 
 533   // link super class before linking this class
 534   instanceKlassHandle super(THREAD, this_oop->super());
 535   if (super.not_null()) {
 536     if (super->is_interface()) {  // check if super class is an interface
 537       ResourceMark rm(THREAD);
 538       Exceptions::fthrow(
 539         THREAD_AND_LOCATION,
 540         vmSymbols::java_lang_IncompatibleClassChangeError(),
 541         "class %s has interface %s as super class",
 542         this_oop->external_name(),
 543         super->external_name()
 544       );
 545       return false;
 546     }
 547 
 548     link_class_impl(super, throw_verifyerror, CHECK_false);
 549   }
 550 
 551   // link all interfaces implemented by this class before linking this class
 552   Array<Klass*>* interfaces = this_oop->local_interfaces();
 553   int num_interfaces = interfaces->length();
 554   for (int index = 0; index < num_interfaces; index++) {
 555     HandleMark hm(THREAD);
 556     instanceKlassHandle ih(THREAD, interfaces->at(index));
 557     link_class_impl(ih, throw_verifyerror, CHECK_false);
 558   }
 559 
 560   // in case the class is linked in the process of linking its superclasses
 561   if (this_oop->is_linked()) {
 562     return true;
 563   }
 564 
 565   // trace only the link time for this klass that includes
 566   // the verification time
 567   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 568                              ClassLoader::perf_class_link_selftime(),
 569                              ClassLoader::perf_classes_linked(),
 570                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 571                              jt->get_thread_stat()->perf_timers_addr(),
 572                              PerfClassTraceTime::CLASS_LINK);
 573 
 574   // verification & rewriting
 575   {
 576     volatile oop init_lock = this_oop->init_lock();
 577     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 578     // rewritten will have been set if loader constraint error found
 579     // on an earlier link attempt
 580     // don't verify or rewrite if already rewritten
 581 
 582     if (!this_oop->is_linked()) {
 583       if (!this_oop->is_rewritten()) {
 584         {
 585           // Timer includes any side effects of class verification (resolution,
 586           // etc), but not recursive entry into verify_code().
 587           PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
 588                                    ClassLoader::perf_class_verify_selftime(),
 589                                    ClassLoader::perf_classes_verified(),
 590                                    jt->get_thread_stat()->perf_recursion_counts_addr(),
 591                                    jt->get_thread_stat()->perf_timers_addr(),
 592                                    PerfClassTraceTime::CLASS_VERIFY);
 593           bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
 594           if (!verify_ok) {
 595             return false;
 596           }
 597         }
 598 
 599         // Just in case a side-effect of verify linked this class already
 600         // (which can sometimes happen since the verifier loads classes
 601         // using custom class loaders, which are free to initialize things)
 602         if (this_oop->is_linked()) {
 603           return true;
 604         }
 605 
 606         // also sets rewritten
 607         this_oop->rewrite_class(CHECK_false);
 608       }
 609 
 610       // relocate jsrs and link methods after they are all rewritten
 611       this_oop->link_methods(CHECK_false);
 612 
 613       // Initialize the vtable and interface table after
 614       // methods have been rewritten since rewrite may
 615       // fabricate new Method*s.
 616       // also does loader constraint checking
 617       if (!this_oop()->is_shared()) {
 618         ResourceMark rm(THREAD);
 619         this_oop->vtable()->initialize_vtable(true, CHECK_false);
 620         this_oop->itable()->initialize_itable(true, CHECK_false);
 621       }
 622 #ifdef ASSERT
 623       else {
 624         ResourceMark rm(THREAD);
 625         this_oop->vtable()->verify(tty, true);
 626         // In case itable verification is ever added.
 627         // this_oop->itable()->verify(tty, true);
 628       }
 629 #endif
 630       this_oop->set_init_state(linked);
 631       if (JvmtiExport::should_post_class_prepare()) {
 632         Thread *thread = THREAD;
 633         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 634         JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
 635       }
 636     }
 637   }
 638   return true;
 639 }
 640 
 641 
 642 // Rewrite the byte codes of all of the methods of a class.
 643 // The rewriter must be called exactly once. Rewriting must happen after
 644 // verification but before the first method of the class is executed.
 645 void InstanceKlass::rewrite_class(TRAPS) {
 646   assert(is_loaded(), "must be loaded");
 647   instanceKlassHandle this_oop(THREAD, this);
 648   if (this_oop->is_rewritten()) {
 649     assert(this_oop()->is_shared(), "rewriting an unshared class?");
 650     return;
 651   }
 652   Rewriter::rewrite(this_oop, CHECK);
 653   this_oop->set_rewritten();
 654 }
 655 
 656 // Now relocate and link method entry points after class is rewritten.
 657 // This is outside is_rewritten flag. In case of an exception, it can be
 658 // executed more than once.
 659 void InstanceKlass::link_methods(TRAPS) {
 660   int len = methods()->length();
 661   for (int i = len-1; i >= 0; i--) {
 662     methodHandle m(THREAD, methods()->at(i));
 663 
 664     // Set up method entry points for compiler and interpreter    .
 665     m->link_method(m, CHECK);
 666 
 667     // This is for JVMTI and unrelated to relocator but the last thing we do
 668 #ifdef ASSERT
 669     if (StressMethodComparator) {
 670       ResourceMark rm(THREAD);
 671       static int nmc = 0;
 672       for (int j = i; j >= 0 && j >= i-4; j--) {
 673         if ((++nmc % 1000) == 0)  tty->print_cr("Have run MethodComparator %d times...", nmc);
 674         bool z = MethodComparator::methods_EMCP(m(),
 675                    methods()->at(j));
 676         if (j == i && !z) {
 677           tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
 678           assert(z, "method must compare equal to itself");
 679         }
 680       }
 681     }
 682 #endif //ASSERT
 683   }
 684 }
 685 
 686 
 687 void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
 688   // Make sure klass is linked (verified) before initialization
 689   // A class could already be verified, since it has been reflected upon.
 690   this_oop->link_class(CHECK);
 691 
 692   DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
 693 
 694   bool wait = false;
 695 
 696   // refer to the JVM book page 47 for description of steps
 697   // Step 1
 698   {
 699     volatile oop init_lock = this_oop->init_lock();
 700     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 701 
 702     Thread *self = THREAD; // it's passed the current thread
 703 
 704     // Step 2
 705     // If we were to use wait() instead of waitInterruptibly() then
 706     // we might end up throwing IE from link/symbol resolution sites
 707     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
 708     while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
 709         wait = true;
 710       ol.waitUninterruptibly(CHECK);
 711     }
 712 
 713     // Step 3
 714     if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
 715       DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
 716       return;
 717     }
 718 
 719     // Step 4
 720     if (this_oop->is_initialized()) {
 721       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
 722       return;
 723     }
 724 
 725     // Step 5
 726     if (this_oop->is_in_error_state()) {
 727       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
 728       ResourceMark rm(THREAD);
 729       const char* desc = "Could not initialize class ";
 730       const char* className = this_oop->external_name();
 731       size_t msglen = strlen(desc) + strlen(className) + 1;
 732       char* message = NEW_RESOURCE_ARRAY(char, msglen);
 733       if (NULL == message) {
 734         // Out of memory: can't create detailed error message
 735         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
 736       } else {
 737         jio_snprintf(message, msglen, "%s%s", desc, className);
 738         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
 739       }
 740     }
 741 
 742     // Step 6
 743     this_oop->set_init_state(being_initialized);
 744     this_oop->set_init_thread(self);
 745   }
 746 
 747   // Step 7
 748   Klass* super_klass = this_oop->super();
 749   if (super_klass != NULL && !this_oop->is_interface() && super_klass->should_be_initialized()) {
 750     super_klass->initialize(THREAD);
 751 
 752     if (HAS_PENDING_EXCEPTION) {
 753       Handle e(THREAD, PENDING_EXCEPTION);
 754       CLEAR_PENDING_EXCEPTION;
 755       {
 756         EXCEPTION_MARK;
 757         this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
 758         CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, superclass initialization error is thrown below
 759       }
 760       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
 761       THROW_OOP(e());
 762     }
 763   }
 764 
 765   if (this_oop->has_default_methods()) {
 766     // Step 7.5: initialize any interfaces which have default methods
 767     for (int i = 0; i < this_oop->local_interfaces()->length(); ++i) {
 768       Klass* iface = this_oop->local_interfaces()->at(i);
 769       InstanceKlass* ik = InstanceKlass::cast(iface);
 770       if (ik->has_default_methods() && ik->should_be_initialized()) {
 771         ik->initialize(THREAD);
 772 
 773         if (HAS_PENDING_EXCEPTION) {
 774           Handle e(THREAD, PENDING_EXCEPTION);
 775           CLEAR_PENDING_EXCEPTION;
 776           {
 777             EXCEPTION_MARK;
 778             // Locks object, set state, and notify all waiting threads
 779             this_oop->set_initialization_state_and_notify(
 780                 initialization_error, THREAD);
 781 
 782             // ignore any exception thrown, superclass initialization error is
 783             // thrown below
 784             CLEAR_PENDING_EXCEPTION;
 785           }
 786           DTRACE_CLASSINIT_PROBE_WAIT(
 787               super__failed, InstanceKlass::cast(this_oop()), -1, wait);
 788           THROW_OOP(e());
 789         }
 790       }
 791     }
 792   }
 793 
 794   // Step 8
 795   {
 796     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
 797     JavaThread* jt = (JavaThread*)THREAD;
 798     DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
 799     // Timer includes any side effects of class initialization (resolution,
 800     // etc), but not recursive entry into call_class_initializer().
 801     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
 802                              ClassLoader::perf_class_init_selftime(),
 803                              ClassLoader::perf_classes_inited(),
 804                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 805                              jt->get_thread_stat()->perf_timers_addr(),
 806                              PerfClassTraceTime::CLASS_CLINIT);
 807     this_oop->call_class_initializer(THREAD);
 808   }
 809 
 810   // Step 9
 811   if (!HAS_PENDING_EXCEPTION) {
 812     this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
 813     { ResourceMark rm(THREAD);
 814       debug_only(this_oop->vtable()->verify(tty, true);)
 815     }
 816   }
 817   else {
 818     // Step 10 and 11
 819     Handle e(THREAD, PENDING_EXCEPTION);
 820     CLEAR_PENDING_EXCEPTION;
 821     {
 822       EXCEPTION_MARK;
 823       this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
 824       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
 825     }
 826     DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
 827     if (e->is_a(SystemDictionary::Error_klass())) {
 828       THROW_OOP(e());
 829     } else {
 830       JavaCallArguments args(e);
 831       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
 832                 vmSymbols::throwable_void_signature(),
 833                 &args);
 834     }
 835   }
 836   DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
 837 }
 838 
 839 
 840 // Note: implementation moved to static method to expose the this pointer.
 841 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
 842   instanceKlassHandle kh(THREAD, this);
 843   set_initialization_state_and_notify_impl(kh, state, CHECK);
 844 }
 845 
 846 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
 847   volatile oop init_lock = this_oop->init_lock();
 848   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 849   this_oop->set_init_state(state);
 850   this_oop->fence_and_clear_init_lock();
 851   ol.notify_all(CHECK);
 852 }
 853 
 854 // The embedded _implementor field can only record one implementor.
 855 // When there are more than one implementors, the _implementor field
 856 // is set to the interface Klass* itself. Following are the possible
 857 // values for the _implementor field:
 858 //   NULL                  - no implementor
 859 //   implementor Klass*    - one implementor
 860 //   self                  - more than one implementor
 861 //
 862 // The _implementor field only exists for interfaces.
 863 void InstanceKlass::add_implementor(Klass* k) {
 864   assert(Compile_lock->owned_by_self(), "");
 865   assert(is_interface(), "not interface");
 866   // Filter out my subinterfaces.
 867   // (Note: Interfaces are never on the subklass list.)
 868   if (InstanceKlass::cast(k)->is_interface()) return;
 869 
 870   // Filter out subclasses whose supers already implement me.
 871   // (Note: CHA must walk subclasses of direct implementors
 872   // in order to locate indirect implementors.)
 873   Klass* sk = InstanceKlass::cast(k)->super();
 874   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
 875     // We only need to check one immediate superclass, since the
 876     // implements_interface query looks at transitive_interfaces.
 877     // Any supers of the super have the same (or fewer) transitive_interfaces.
 878     return;
 879 
 880   Klass* ik = implementor();
 881   if (ik == NULL) {
 882     set_implementor(k);
 883   } else if (ik != this) {
 884     // There is already an implementor. Use itself as an indicator of
 885     // more than one implementors.
 886     set_implementor(this);
 887   }
 888 
 889   // The implementor also implements the transitive_interfaces
 890   for (int index = 0; index < local_interfaces()->length(); index++) {
 891     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
 892   }
 893 }
 894 
 895 void InstanceKlass::init_implementor() {
 896   if (is_interface()) {
 897     set_implementor(NULL);
 898   }
 899 }
 900 
 901 
 902 void InstanceKlass::process_interfaces(Thread *thread) {
 903   // link this class into the implementors list of every interface it implements
 904   Klass* this_as_klass_oop = this;
 905   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
 906     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
 907     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
 908     assert(interf->is_interface(), "expected interface");
 909     interf->add_implementor(this_as_klass_oop);
 910   }
 911 }
 912 
 913 bool InstanceKlass::can_be_primary_super_slow() const {
 914   if (is_interface())
 915     return false;
 916   else
 917     return Klass::can_be_primary_super_slow();
 918 }
 919 
 920 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
 921   // The secondaries are the implemented interfaces.
 922   InstanceKlass* ik = InstanceKlass::cast(this);
 923   Array<Klass*>* interfaces = ik->transitive_interfaces();
 924   int num_secondaries = num_extra_slots + interfaces->length();
 925   if (num_secondaries == 0) {
 926     // Must share this for correct bootstrapping!
 927     set_secondary_supers(Universe::the_empty_klass_array());
 928     return NULL;
 929   } else if (num_extra_slots == 0) {
 930     // The secondary super list is exactly the same as the transitive interfaces.
 931     // Redefine classes has to be careful not to delete this!
 932     set_secondary_supers(interfaces);
 933     return NULL;
 934   } else {
 935     // Copy transitive interfaces to a temporary growable array to be constructed
 936     // into the secondary super list with extra slots.
 937     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
 938     for (int i = 0; i < interfaces->length(); i++) {
 939       secondaries->push(interfaces->at(i));
 940     }
 941     return secondaries;
 942   }
 943 }
 944 
 945 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
 946   if (k->is_interface()) {
 947     return implements_interface(k);
 948   } else {
 949     return Klass::compute_is_subtype_of(k);
 950   }
 951 }
 952 
 953 bool InstanceKlass::implements_interface(Klass* k) const {
 954   if (this == k) return true;
 955   assert(k->is_interface(), "should be an interface class");
 956   for (int i = 0; i < transitive_interfaces()->length(); i++) {
 957     if (transitive_interfaces()->at(i) == k) {
 958       return true;
 959     }
 960   }
 961   return false;
 962 }
 963 
 964 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
 965   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
 966   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
 967     report_java_out_of_memory("Requested array size exceeds VM limit");
 968     JvmtiExport::post_array_size_exhausted();
 969     THROW_OOP_0(Universe::out_of_memory_error_array_size());
 970   }
 971   int size = objArrayOopDesc::object_size(length);
 972   Klass* ak = array_klass(n, CHECK_NULL);
 973   KlassHandle h_ak (THREAD, ak);
 974   objArrayOop o =
 975     (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
 976   return o;
 977 }
 978 
 979 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
 980   if (TraceFinalizerRegistration) {
 981     tty->print("Registered ");
 982     i->print_value_on(tty);
 983     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
 984   }
 985   instanceHandle h_i(THREAD, i);
 986   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
 987   JavaValue result(T_VOID);
 988   JavaCallArguments args(h_i);
 989   methodHandle mh (THREAD, Universe::finalizer_register_method());
 990   JavaCalls::call(&result, mh, &args, CHECK_NULL);
 991   return h_i();
 992 }
 993 
 994 instanceOop InstanceKlass::allocate_instance(TRAPS) {
 995   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
 996   int size = size_helper();  // Query before forming handle.
 997 
 998   KlassHandle h_k(THREAD, this);
 999 
1000   instanceOop i;
1001 
1002   i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
1003   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1004     i = register_finalizer(i, CHECK_NULL);
1005   }
1006   return i;
1007 }
1008 
1009 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1010   if (is_interface() || is_abstract()) {
1011     ResourceMark rm(THREAD);
1012     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1013               : vmSymbols::java_lang_InstantiationException(), external_name());
1014   }
1015   if (this == SystemDictionary::Class_klass()) {
1016     ResourceMark rm(THREAD);
1017     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1018               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1019   }
1020 }
1021 
1022 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1023   instanceKlassHandle this_oop(THREAD, this);
1024   return array_klass_impl(this_oop, or_null, n, THREAD);
1025 }
1026 
1027 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
1028   if (this_oop->array_klasses() == NULL) {
1029     if (or_null) return NULL;
1030 
1031     ResourceMark rm;
1032     JavaThread *jt = (JavaThread *)THREAD;
1033     {
1034       // Atomic creation of array_klasses
1035       MutexLocker mc(Compile_lock, THREAD);   // for vtables
1036       MutexLocker ma(MultiArray_lock, THREAD);
1037 
1038       // Check if update has already taken place
1039       if (this_oop->array_klasses() == NULL) {
1040         Klass*    k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
1041         this_oop->set_array_klasses(k);
1042       }
1043     }
1044   }
1045   // _this will always be set at this point
1046   ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
1047   if (or_null) {
1048     return oak->array_klass_or_null(n);
1049   }
1050   return oak->array_klass(n, CHECK_NULL);
1051 }
1052 
1053 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1054   return array_klass_impl(or_null, 1, THREAD);
1055 }
1056 
1057 void InstanceKlass::call_class_initializer(TRAPS) {
1058   instanceKlassHandle ik (THREAD, this);
1059   call_class_initializer_impl(ik, THREAD);
1060 }
1061 
1062 static int call_class_initializer_impl_counter = 0;   // for debugging
1063 
1064 Method* InstanceKlass::class_initializer() {
1065   Method* clinit = find_method(
1066       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1067   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1068     return clinit;
1069   }
1070   return NULL;
1071 }
1072 
1073 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
1074   if (ReplayCompiles &&
1075       (ReplaySuppressInitializers == 1 ||
1076        ReplaySuppressInitializers >= 2 && this_oop->class_loader() != NULL)) {
1077     // Hide the existence of the initializer for the purpose of replaying the compile
1078     return;
1079   }
1080 
1081   methodHandle h_method(THREAD, this_oop->class_initializer());
1082   assert(!this_oop->is_initialized(), "we cannot initialize twice");
1083   if (TraceClassInitialization) {
1084     tty->print("%d Initializing ", call_class_initializer_impl_counter++);
1085     this_oop->name()->print_value();
1086     tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
1087   }
1088   if (h_method() != NULL) {
1089     JavaCallArguments args; // No arguments
1090     JavaValue result(T_VOID);
1091     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1092   }
1093 }
1094 
1095 
1096 void InstanceKlass::mask_for(methodHandle method, int bci,
1097   InterpreterOopMap* entry_for) {
1098   // Dirty read, then double-check under a lock.
1099   if (_oop_map_cache == NULL) {
1100     // Otherwise, allocate a new one.
1101     MutexLocker x(OopMapCacheAlloc_lock);
1102     // First time use. Allocate a cache in C heap
1103     if (_oop_map_cache == NULL) {
1104       _oop_map_cache = new OopMapCache();
1105     }
1106   }
1107   // _oop_map_cache is constant after init; lookup below does is own locking.
1108   _oop_map_cache->lookup(method, bci, entry_for);
1109 }
1110 
1111 
1112 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1113   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1114     Symbol* f_name = fs.name();
1115     Symbol* f_sig  = fs.signature();
1116     if (f_name == name && f_sig == sig) {
1117       fd->initialize(const_cast<InstanceKlass*>(this), fs.index());
1118       return true;
1119     }
1120   }
1121   return false;
1122 }
1123 
1124 
1125 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1126   const int n = local_interfaces()->length();
1127   for (int i = 0; i < n; i++) {
1128     Klass* intf1 = local_interfaces()->at(i);
1129     assert(intf1->is_interface(), "just checking type");
1130     // search for field in current interface
1131     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1132       assert(fd->is_static(), "interface field must be static");
1133       return intf1;
1134     }
1135     // search for field in direct superinterfaces
1136     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1137     if (intf2 != NULL) return intf2;
1138   }
1139   // otherwise field lookup fails
1140   return NULL;
1141 }
1142 
1143 
1144 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1145   // search order according to newest JVM spec (5.4.3.2, p.167).
1146   // 1) search for field in current klass
1147   if (find_local_field(name, sig, fd)) {
1148     return const_cast<InstanceKlass*>(this);
1149   }
1150   // 2) search for field recursively in direct superinterfaces
1151   { Klass* intf = find_interface_field(name, sig, fd);
1152     if (intf != NULL) return intf;
1153   }
1154   // 3) apply field lookup recursively if superclass exists
1155   { Klass* supr = super();
1156     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1157   }
1158   // 4) otherwise field lookup fails
1159   return NULL;
1160 }
1161 
1162 
1163 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1164   // search order according to newest JVM spec (5.4.3.2, p.167).
1165   // 1) search for field in current klass
1166   if (find_local_field(name, sig, fd)) {
1167     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1168   }
1169   // 2) search for field recursively in direct superinterfaces
1170   if (is_static) {
1171     Klass* intf = find_interface_field(name, sig, fd);
1172     if (intf != NULL) return intf;
1173   }
1174   // 3) apply field lookup recursively if superclass exists
1175   { Klass* supr = super();
1176     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1177   }
1178   // 4) otherwise field lookup fails
1179   return NULL;
1180 }
1181 
1182 
1183 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1184   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1185     if (fs.offset() == offset) {
1186       fd->initialize(const_cast<InstanceKlass*>(this), fs.index());
1187       if (fd->is_static() == is_static) return true;
1188     }
1189   }
1190   return false;
1191 }
1192 
1193 
1194 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1195   Klass* klass = const_cast<InstanceKlass*>(this);
1196   while (klass != NULL) {
1197     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1198       return true;
1199     }
1200     klass = klass->super();
1201   }
1202   return false;
1203 }
1204 
1205 
1206 void InstanceKlass::methods_do(void f(Method* method)) {
1207   int len = methods()->length();
1208   for (int index = 0; index < len; index++) {
1209     Method* m = methods()->at(index);
1210     assert(m->is_method(), "must be method");
1211     f(m);
1212   }
1213 }
1214 
1215 
1216 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1217   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1218     if (fs.access_flags().is_static()) {
1219       fieldDescriptor fd;
1220       fd.initialize(this, fs.index());
1221       cl->do_field(&fd);
1222     }
1223   }
1224 }
1225 
1226 
1227 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
1228   instanceKlassHandle h_this(THREAD, this);
1229   do_local_static_fields_impl(h_this, f, CHECK);
1230 }
1231 
1232 
1233 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
1234   for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
1235     if (fs.access_flags().is_static()) {
1236       fieldDescriptor fd;
1237       fd.initialize(this_oop(), fs.index());
1238       f(&fd, CHECK);
1239     }
1240   }
1241 }
1242 
1243 
1244 static int compare_fields_by_offset(int* a, int* b) {
1245   return a[0] - b[0];
1246 }
1247 
1248 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1249   InstanceKlass* super = superklass();
1250   if (super != NULL) {
1251     super->do_nonstatic_fields(cl);
1252   }
1253   fieldDescriptor fd;
1254   int length = java_fields_count();
1255   // In DebugInfo nonstatic fields are sorted by offset.
1256   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1257   int j = 0;
1258   for (int i = 0; i < length; i += 1) {
1259     fd.initialize(this, i);
1260     if (!fd.is_static()) {
1261       fields_sorted[j + 0] = fd.offset();
1262       fields_sorted[j + 1] = i;
1263       j += 2;
1264     }
1265   }
1266   if (j > 0) {
1267     length = j;
1268     // _sort_Fn is defined in growableArray.hpp.
1269     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1270     for (int i = 0; i < length; i += 2) {
1271       fd.initialize(this, fields_sorted[i + 1]);
1272       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1273       cl->do_field(&fd);
1274     }
1275   }
1276   FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
1277 }
1278 
1279 
1280 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1281   if (array_klasses() != NULL)
1282     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1283 }
1284 
1285 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1286   if (array_klasses() != NULL)
1287     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1288 }
1289 
1290 
1291 void InstanceKlass::with_array_klasses_do(void f(Klass* k)) {
1292   f(this);
1293   array_klasses_do(f);
1294 }
1295 
1296 #ifdef ASSERT
1297 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
1298   int len = methods->length();
1299   for (int index = 0; index < len; index++) {
1300     Method* m = methods->at(index);
1301     assert(m->is_method(), "must be method");
1302     if (m->signature() == signature && m->name() == name) {
1303        return index;
1304     }
1305   }
1306   return -1;
1307 }
1308 #endif
1309 
1310 static int binary_search(Array<Method*>* methods, Symbol* name) {
1311   int len = methods->length();
1312   // methods are sorted, so do binary search
1313   int l = 0;
1314   int h = len - 1;
1315   while (l <= h) {
1316     int mid = (l + h) >> 1;
1317     Method* m = methods->at(mid);
1318     assert(m->is_method(), "must be method");
1319     int res = m->name()->fast_compare(name);
1320     if (res == 0) {
1321       return mid;
1322     } else if (res < 0) {
1323       l = mid + 1;
1324     } else {
1325       h = mid - 1;
1326     }
1327   }
1328   return -1;
1329 }
1330 
1331 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
1332   return InstanceKlass::find_method(methods(), name, signature);
1333 }
1334 
1335 Method* InstanceKlass::find_method(
1336     Array<Method*>* methods, Symbol* name, Symbol* signature) {
1337   int hit = binary_search(methods, name);
1338   if (hit != -1) {
1339     Method* m = methods->at(hit);
1340     // Do linear search to find matching signature.  First, quick check
1341     // for common case
1342     if (m->signature() == signature) return m;
1343     // search downwards through overloaded methods
1344     int i;
1345     for (i = hit - 1; i >= 0; --i) {
1346         Method* m = methods->at(i);
1347         assert(m->is_method(), "must be method");
1348         if (m->name() != name) break;
1349         if (m->signature() == signature) return m;
1350     }
1351     // search upwards
1352     for (i = hit + 1; i < methods->length(); ++i) {
1353         Method* m = methods->at(i);
1354         assert(m->is_method(), "must be method");
1355         if (m->name() != name) break;
1356         if (m->signature() == signature) return m;
1357     }
1358     // not found
1359 #ifdef ASSERT
1360     int index = linear_search(methods, name, signature);
1361     assert(index == -1, err_msg("binary search should have found entry %d", index));
1362 #endif
1363   }
1364   return NULL;
1365 }
1366 
1367 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
1368   return find_method_by_name(methods(), name, end);
1369 }
1370 
1371 int InstanceKlass::find_method_by_name(
1372     Array<Method*>* methods, Symbol* name, int* end_ptr) {
1373   assert(end_ptr != NULL, "just checking");
1374   int start = binary_search(methods, name);
1375   int end = start + 1;
1376   if (start != -1) {
1377     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1378     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1379     *end_ptr = end;
1380     return start;
1381   }
1382   return -1;
1383 }
1384 
1385 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
1386   Klass* klass = const_cast<InstanceKlass*>(this);
1387   while (klass != NULL) {
1388     Method* method = InstanceKlass::cast(klass)->find_method(name, signature);
1389     if (method != NULL) return method;
1390     klass = InstanceKlass::cast(klass)->super();
1391   }
1392   return NULL;
1393 }
1394 
1395 // lookup a method in all the interfaces that this class implements
1396 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1397                                                          Symbol* signature) const {
1398   Array<Klass*>* all_ifs = transitive_interfaces();
1399   int num_ifs = all_ifs->length();
1400   InstanceKlass *ik = NULL;
1401   for (int i = 0; i < num_ifs; i++) {
1402     ik = InstanceKlass::cast(all_ifs->at(i));
1403     Method* m = ik->lookup_method(name, signature);
1404     if (m != NULL) {
1405       return m;
1406     }
1407   }
1408   return NULL;
1409 }
1410 
1411 /* jni_id_for_impl for jfieldIds only */
1412 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
1413   MutexLocker ml(JfieldIdCreation_lock);
1414   // Retry lookup after we got the lock
1415   JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
1416   if (probe == NULL) {
1417     // Slow case, allocate new static field identifier
1418     probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
1419     this_oop->set_jni_ids(probe);
1420   }
1421   return probe;
1422 }
1423 
1424 
1425 /* jni_id_for for jfieldIds only */
1426 JNIid* InstanceKlass::jni_id_for(int offset) {
1427   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1428   if (probe == NULL) {
1429     probe = jni_id_for_impl(this, offset);
1430   }
1431   return probe;
1432 }
1433 
1434 u2 InstanceKlass::enclosing_method_data(int offset) {
1435   Array<jushort>* inner_class_list = inner_classes();
1436   if (inner_class_list == NULL) {
1437     return 0;
1438   }
1439   int length = inner_class_list->length();
1440   if (length % inner_class_next_offset == 0) {
1441     return 0;
1442   } else {
1443     int index = length - enclosing_method_attribute_size;
1444     assert(offset < enclosing_method_attribute_size, "invalid offset");
1445     return inner_class_list->at(index + offset);
1446   }
1447 }
1448 
1449 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1450                                                  u2 method_index) {
1451   Array<jushort>* inner_class_list = inner_classes();
1452   assert (inner_class_list != NULL, "_inner_classes list is not set up");
1453   int length = inner_class_list->length();
1454   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1455     int index = length - enclosing_method_attribute_size;
1456     inner_class_list->at_put(
1457       index + enclosing_method_class_index_offset, class_index);
1458     inner_class_list->at_put(
1459       index + enclosing_method_method_index_offset, method_index);
1460   }
1461 }
1462 
1463 // Lookup or create a jmethodID.
1464 // This code is called by the VMThread and JavaThreads so the
1465 // locking has to be done very carefully to avoid deadlocks
1466 // and/or other cache consistency problems.
1467 //
1468 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1469   size_t idnum = (size_t)method_h->method_idnum();
1470   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1471   size_t length = 0;
1472   jmethodID id = NULL;
1473 
1474   // We use a double-check locking idiom here because this cache is
1475   // performance sensitive. In the normal system, this cache only
1476   // transitions from NULL to non-NULL which is safe because we use
1477   // release_set_methods_jmethod_ids() to advertise the new cache.
1478   // A partially constructed cache should never be seen by a racing
1479   // thread. We also use release_store_ptr() to save a new jmethodID
1480   // in the cache so a partially constructed jmethodID should never be
1481   // seen either. Cache reads of existing jmethodIDs proceed without a
1482   // lock, but cache writes of a new jmethodID requires uniqueness and
1483   // creation of the cache itself requires no leaks so a lock is
1484   // generally acquired in those two cases.
1485   //
1486   // If the RedefineClasses() API has been used, then this cache can
1487   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1488   // Cache creation requires no leaks and we require safety between all
1489   // cache accesses and freeing of the old cache so a lock is generally
1490   // acquired when the RedefineClasses() API has been used.
1491 
1492   if (jmeths != NULL) {
1493     // the cache already exists
1494     if (!ik_h->idnum_can_increment()) {
1495       // the cache can't grow so we can just get the current values
1496       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1497     } else {
1498       // cache can grow so we have to be more careful
1499       if (Threads::number_of_threads() == 0 ||
1500           SafepointSynchronize::is_at_safepoint()) {
1501         // we're single threaded or at a safepoint - no locking needed
1502         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1503       } else {
1504         MutexLocker ml(JmethodIdCreation_lock);
1505         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1506       }
1507     }
1508   }
1509   // implied else:
1510   // we need to allocate a cache so default length and id values are good
1511 
1512   if (jmeths == NULL ||   // no cache yet
1513       length <= idnum ||  // cache is too short
1514       id == NULL) {       // cache doesn't contain entry
1515 
1516     // This function can be called by the VMThread so we have to do all
1517     // things that might block on a safepoint before grabbing the lock.
1518     // Otherwise, we can deadlock with the VMThread or have a cache
1519     // consistency issue. These vars keep track of what we might have
1520     // to free after the lock is dropped.
1521     jmethodID  to_dealloc_id     = NULL;
1522     jmethodID* to_dealloc_jmeths = NULL;
1523 
1524     // may not allocate new_jmeths or use it if we allocate it
1525     jmethodID* new_jmeths = NULL;
1526     if (length <= idnum) {
1527       // allocate a new cache that might be used
1528       size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1529       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1530       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1531       // cache size is stored in element[0], other elements offset by one
1532       new_jmeths[0] = (jmethodID)size;
1533     }
1534 
1535     // allocate a new jmethodID that might be used
1536     jmethodID new_id = NULL;
1537     if (method_h->is_old() && !method_h->is_obsolete()) {
1538       // The method passed in is old (but not obsolete), we need to use the current version
1539       Method* current_method = ik_h->method_with_idnum((int)idnum);
1540       assert(current_method != NULL, "old and but not obsolete, so should exist");
1541       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
1542     } else {
1543       // It is the current version of the method or an obsolete method,
1544       // use the version passed in
1545       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
1546     }
1547 
1548     if (Threads::number_of_threads() == 0 ||
1549         SafepointSynchronize::is_at_safepoint()) {
1550       // we're single threaded or at a safepoint - no locking needed
1551       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1552                                           &to_dealloc_id, &to_dealloc_jmeths);
1553     } else {
1554       MutexLocker ml(JmethodIdCreation_lock);
1555       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1556                                           &to_dealloc_id, &to_dealloc_jmeths);
1557     }
1558 
1559     // The lock has been dropped so we can free resources.
1560     // Free up either the old cache or the new cache if we allocated one.
1561     if (to_dealloc_jmeths != NULL) {
1562       FreeHeap(to_dealloc_jmeths);
1563     }
1564     // free up the new ID since it wasn't needed
1565     if (to_dealloc_id != NULL) {
1566       Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
1567     }
1568   }
1569   return id;
1570 }
1571 
1572 
1573 // Common code to fetch the jmethodID from the cache or update the
1574 // cache with the new jmethodID. This function should never do anything
1575 // that causes the caller to go to a safepoint or we can deadlock with
1576 // the VMThread or have cache consistency issues.
1577 //
1578 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1579             instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1580             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1581             jmethodID** to_dealloc_jmeths_p) {
1582   assert(new_id != NULL, "sanity check");
1583   assert(to_dealloc_id_p != NULL, "sanity check");
1584   assert(to_dealloc_jmeths_p != NULL, "sanity check");
1585   assert(Threads::number_of_threads() == 0 ||
1586          SafepointSynchronize::is_at_safepoint() ||
1587          JmethodIdCreation_lock->owned_by_self(), "sanity check");
1588 
1589   // reacquire the cache - we are locked, single threaded or at a safepoint
1590   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1591   jmethodID  id     = NULL;
1592   size_t     length = 0;
1593 
1594   if (jmeths == NULL ||                         // no cache yet
1595       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
1596     if (jmeths != NULL) {
1597       // copy any existing entries from the old cache
1598       for (size_t index = 0; index < length; index++) {
1599         new_jmeths[index+1] = jmeths[index+1];
1600       }
1601       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
1602     }
1603     ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1604   } else {
1605     // fetch jmethodID (if any) from the existing cache
1606     id = jmeths[idnum+1];
1607     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
1608   }
1609   if (id == NULL) {
1610     // No matching jmethodID in the existing cache or we have a new
1611     // cache or we just grew the cache. This cache write is done here
1612     // by the first thread to win the foot race because a jmethodID
1613     // needs to be unique once it is generally available.
1614     id = new_id;
1615 
1616     // The jmethodID cache can be read while unlocked so we have to
1617     // make sure the new jmethodID is complete before installing it
1618     // in the cache.
1619     OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1620   } else {
1621     *to_dealloc_id_p = new_id; // save new id for later delete
1622   }
1623   return id;
1624 }
1625 
1626 
1627 // Common code to get the jmethodID cache length and the jmethodID
1628 // value at index idnum if there is one.
1629 //
1630 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1631        size_t idnum, size_t *length_p, jmethodID* id_p) {
1632   assert(cache != NULL, "sanity check");
1633   assert(length_p != NULL, "sanity check");
1634   assert(id_p != NULL, "sanity check");
1635 
1636   // cache size is stored in element[0], other elements offset by one
1637   *length_p = (size_t)cache[0];
1638   if (*length_p <= idnum) {  // cache is too short
1639     *id_p = NULL;
1640   } else {
1641     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
1642   }
1643 }
1644 
1645 
1646 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
1647 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1648   size_t idnum = (size_t)method->method_idnum();
1649   jmethodID* jmeths = methods_jmethod_ids_acquire();
1650   size_t length;                                // length assigned as debugging crumb
1651   jmethodID id = NULL;
1652   if (jmeths != NULL &&                         // If there is a cache
1653       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
1654     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
1655   }
1656   return id;
1657 }
1658 
1659 
1660 // Cache an itable index
1661 void InstanceKlass::set_cached_itable_index(size_t idnum, int index) {
1662   int* indices = methods_cached_itable_indices_acquire();
1663   int* to_dealloc_indices = NULL;
1664 
1665   // We use a double-check locking idiom here because this cache is
1666   // performance sensitive. In the normal system, this cache only
1667   // transitions from NULL to non-NULL which is safe because we use
1668   // release_set_methods_cached_itable_indices() to advertise the
1669   // new cache. A partially constructed cache should never be seen
1670   // by a racing thread. Cache reads and writes proceed without a
1671   // lock, but creation of the cache itself requires no leaks so a
1672   // lock is generally acquired in that case.
1673   //
1674   // If the RedefineClasses() API has been used, then this cache can
1675   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1676   // Cache creation requires no leaks and we require safety between all
1677   // cache accesses and freeing of the old cache so a lock is generally
1678   // acquired when the RedefineClasses() API has been used.
1679 
1680   if (indices == NULL || idnum_can_increment()) {
1681     // we need a cache or the cache can grow
1682     MutexLocker ml(JNICachedItableIndex_lock);
1683     // reacquire the cache to see if another thread already did the work
1684     indices = methods_cached_itable_indices_acquire();
1685     size_t length = 0;
1686     // cache size is stored in element[0], other elements offset by one
1687     if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
1688       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1689       int* new_indices = NEW_C_HEAP_ARRAY(int, size+1, mtClass);
1690       new_indices[0] = (int)size;
1691       // copy any existing entries
1692       size_t i;
1693       for (i = 0; i < length; i++) {
1694         new_indices[i+1] = indices[i+1];
1695       }
1696       // Set all the rest to -1
1697       for (i = length; i < size; i++) {
1698         new_indices[i+1] = -1;
1699       }
1700       if (indices != NULL) {
1701         // We have an old cache to delete so save it for after we
1702         // drop the lock.
1703         to_dealloc_indices = indices;
1704       }
1705       release_set_methods_cached_itable_indices(indices = new_indices);
1706     }
1707 
1708     if (idnum_can_increment()) {
1709       // this cache can grow so we have to write to it safely
1710       indices[idnum+1] = index;
1711     }
1712   } else {
1713     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
1714   }
1715 
1716   if (!idnum_can_increment()) {
1717     // The cache cannot grow and this JNI itable index value does not
1718     // have to be unique like a jmethodID. If there is a race to set it,
1719     // it doesn't matter.
1720     indices[idnum+1] = index;
1721   }
1722 
1723   if (to_dealloc_indices != NULL) {
1724     // we allocated a new cache so free the old one
1725     FreeHeap(to_dealloc_indices);
1726   }
1727 }
1728 
1729 
1730 // Retrieve a cached itable index
1731 int InstanceKlass::cached_itable_index(size_t idnum) {
1732   int* indices = methods_cached_itable_indices_acquire();
1733   if (indices != NULL && ((size_t)indices[0]) > idnum) {
1734      // indices exist and are long enough, retrieve possible cached
1735     return indices[idnum+1];
1736   }
1737   return -1;
1738 }
1739 
1740 
1741 //
1742 // Walk the list of dependent nmethods searching for nmethods which
1743 // are dependent on the changes that were passed in and mark them for
1744 // deoptimization.  Returns the number of nmethods found.
1745 //
1746 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
1747   assert_locked_or_safepoint(CodeCache_lock);
1748   int found = 0;
1749   nmethodBucket* b = _dependencies;
1750   while (b != NULL) {
1751     nmethod* nm = b->get_nmethod();
1752     // since dependencies aren't removed until an nmethod becomes a zombie,
1753     // the dependency list may contain nmethods which aren't alive.
1754     if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1755       if (TraceDependencies) {
1756         ResourceMark rm;
1757         tty->print_cr("Marked for deoptimization");
1758         tty->print_cr("  context = %s", this->external_name());
1759         changes.print();
1760         nm->print();
1761         nm->print_dependencies();
1762       }
1763       nm->mark_for_deoptimization();
1764       found++;
1765     }
1766     b = b->next();
1767   }
1768   return found;
1769 }
1770 
1771 
1772 //
1773 // Add an nmethodBucket to the list of dependencies for this nmethod.
1774 // It's possible that an nmethod has multiple dependencies on this klass
1775 // so a count is kept for each bucket to guarantee that creation and
1776 // deletion of dependencies is consistent.
1777 //
1778 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1779   assert_locked_or_safepoint(CodeCache_lock);
1780   nmethodBucket* b = _dependencies;
1781   nmethodBucket* last = NULL;
1782   while (b != NULL) {
1783     if (nm == b->get_nmethod()) {
1784       b->increment();
1785       return;
1786     }
1787     b = b->next();
1788   }
1789   _dependencies = new nmethodBucket(nm, _dependencies);
1790 }
1791 
1792 
1793 //
1794 // Decrement count of the nmethod in the dependency list and remove
1795 // the bucket competely when the count goes to 0.  This method must
1796 // find a corresponding bucket otherwise there's a bug in the
1797 // recording of dependecies.
1798 //
1799 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
1800   assert_locked_or_safepoint(CodeCache_lock);
1801   nmethodBucket* b = _dependencies;
1802   nmethodBucket* last = NULL;
1803   while (b != NULL) {
1804     if (nm == b->get_nmethod()) {
1805       if (b->decrement() == 0) {
1806         if (last == NULL) {
1807           _dependencies = b->next();
1808         } else {
1809           last->set_next(b->next());
1810         }
1811         delete b;
1812       }
1813       return;
1814     }
1815     last = b;
1816     b = b->next();
1817   }
1818 #ifdef ASSERT
1819   tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1820   nm->print();
1821 #endif // ASSERT
1822   ShouldNotReachHere();
1823 }
1824 
1825 
1826 #ifndef PRODUCT
1827 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1828   nmethodBucket* b = _dependencies;
1829   int idx = 0;
1830   while (b != NULL) {
1831     nmethod* nm = b->get_nmethod();
1832     tty->print("[%d] count=%d { ", idx++, b->count());
1833     if (!verbose) {
1834       nm->print_on(tty, "nmethod");
1835       tty->print_cr(" } ");
1836     } else {
1837       nm->print();
1838       nm->print_dependencies();
1839       tty->print_cr("--- } ");
1840     }
1841     b = b->next();
1842   }
1843 }
1844 
1845 
1846 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1847   nmethodBucket* b = _dependencies;
1848   while (b != NULL) {
1849     if (nm == b->get_nmethod()) {
1850       return true;
1851     }
1852     b = b->next();
1853   }
1854   return false;
1855 }
1856 #endif //PRODUCT
1857 
1858 
1859 // Garbage collection
1860 
1861 void InstanceKlass::oops_do(OopClosure* cl) {
1862   Klass::oops_do(cl);
1863 
1864   cl->do_oop(adr_protection_domain());
1865   cl->do_oop(adr_signers());
1866   cl->do_oop(adr_init_lock());
1867 
1868   // Don't walk the arrays since they are walked from the ClassLoaderData objects.
1869 }
1870 
1871 #ifdef ASSERT
1872 template <class T> void assert_is_in(T *p) {
1873   T heap_oop = oopDesc::load_heap_oop(p);
1874   if (!oopDesc::is_null(heap_oop)) {
1875     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1876     assert(Universe::heap()->is_in(o), "should be in heap");
1877   }
1878 }
1879 template <class T> void assert_is_in_closed_subset(T *p) {
1880   T heap_oop = oopDesc::load_heap_oop(p);
1881   if (!oopDesc::is_null(heap_oop)) {
1882     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1883     assert(Universe::heap()->is_in_closed_subset(o),
1884            err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
1885   }
1886 }
1887 template <class T> void assert_is_in_reserved(T *p) {
1888   T heap_oop = oopDesc::load_heap_oop(p);
1889   if (!oopDesc::is_null(heap_oop)) {
1890     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1891     assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
1892   }
1893 }
1894 template <class T> void assert_nothing(T *p) {}
1895 
1896 #else
1897 template <class T> void assert_is_in(T *p) {}
1898 template <class T> void assert_is_in_closed_subset(T *p) {}
1899 template <class T> void assert_is_in_reserved(T *p) {}
1900 template <class T> void assert_nothing(T *p) {}
1901 #endif // ASSERT
1902 
1903 //
1904 // Macros that iterate over areas of oops which are specialized on type of
1905 // oop pointer either narrow or wide, depending on UseCompressedOops
1906 //
1907 // Parameters are:
1908 //   T         - type of oop to point to (either oop or narrowOop)
1909 //   start_p   - starting pointer for region to iterate over
1910 //   count     - number of oops or narrowOops to iterate over
1911 //   do_oop    - action to perform on each oop (it's arbitrary C code which
1912 //               makes it more efficient to put in a macro rather than making
1913 //               it a template function)
1914 //   assert_fn - assert function which is template function because performance
1915 //               doesn't matter when enabled.
1916 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
1917   T, start_p, count, do_oop,                \
1918   assert_fn)                                \
1919 {                                           \
1920   T* p         = (T*)(start_p);             \
1921   T* const end = p + (count);               \
1922   while (p < end) {                         \
1923     (assert_fn)(p);                         \
1924     do_oop;                                 \
1925     ++p;                                    \
1926   }                                         \
1927 }
1928 
1929 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
1930   T, start_p, count, do_oop,                \
1931   assert_fn)                                \
1932 {                                           \
1933   T* const start = (T*)(start_p);           \
1934   T*       p     = start + (count);         \
1935   while (start < p) {                       \
1936     --p;                                    \
1937     (assert_fn)(p);                         \
1938     do_oop;                                 \
1939   }                                         \
1940 }
1941 
1942 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
1943   T, start_p, count, low, high,             \
1944   do_oop, assert_fn)                        \
1945 {                                           \
1946   T* const l = (T*)(low);                   \
1947   T* const h = (T*)(high);                  \
1948   assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
1949          mask_bits((intptr_t)h, sizeof(T)-1) == 0,   \
1950          "bounded region must be properly aligned"); \
1951   T* p       = (T*)(start_p);               \
1952   T* end     = p + (count);                 \
1953   if (p < l) p = l;                         \
1954   if (end > h) end = h;                     \
1955   while (p < end) {                         \
1956     (assert_fn)(p);                         \
1957     do_oop;                                 \
1958     ++p;                                    \
1959   }                                         \
1960 }
1961 
1962 
1963 // The following macros call specialized macros, passing either oop or
1964 // narrowOop as the specialization type.  These test the UseCompressedOops
1965 // flag.
1966 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn)            \
1967 {                                                                        \
1968   /* Compute oopmap block range. The common case                         \
1969      is nonstatic_oop_map_size == 1. */                                  \
1970   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
1971   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
1972   if (UseCompressedOops) {                                               \
1973     while (map < end_map) {                                              \
1974       InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop,                   \
1975         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
1976         do_oop, assert_fn)                                               \
1977       ++map;                                                             \
1978     }                                                                    \
1979   } else {                                                               \
1980     while (map < end_map) {                                              \
1981       InstanceKlass_SPECIALIZED_OOP_ITERATE(oop,                         \
1982         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
1983         do_oop, assert_fn)                                               \
1984       ++map;                                                             \
1985     }                                                                    \
1986   }                                                                      \
1987 }
1988 
1989 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn)    \
1990 {                                                                        \
1991   OopMapBlock* const start_map = start_of_nonstatic_oop_maps();          \
1992   OopMapBlock* map             = start_map + nonstatic_oop_map_count();  \
1993   if (UseCompressedOops) {                                               \
1994     while (start_map < map) {                                            \
1995       --map;                                                             \
1996       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop,           \
1997         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
1998         do_oop, assert_fn)                                               \
1999     }                                                                    \
2000   } else {                                                               \
2001     while (start_map < map) {                                            \
2002       --map;                                                             \
2003       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop,                 \
2004         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
2005         do_oop, assert_fn)                                               \
2006     }                                                                    \
2007   }                                                                      \
2008 }
2009 
2010 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop,    \
2011                                               assert_fn)                 \
2012 {                                                                        \
2013   /* Compute oopmap block range. The common case is                      \
2014      nonstatic_oop_map_size == 1, so we accept the                       \
2015      usually non-existent extra overhead of examining                    \
2016      all the maps. */                                                    \
2017   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
2018   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
2019   if (UseCompressedOops) {                                               \
2020     while (map < end_map) {                                              \
2021       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop,           \
2022         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
2023         low, high,                                                       \
2024         do_oop, assert_fn)                                               \
2025       ++map;                                                             \
2026     }                                                                    \
2027   } else {                                                               \
2028     while (map < end_map) {                                              \
2029       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop,                 \
2030         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
2031         low, high,                                                       \
2032         do_oop, assert_fn)                                               \
2033       ++map;                                                             \
2034     }                                                                    \
2035   }                                                                      \
2036 }
2037 
2038 void InstanceKlass::oop_follow_contents(oop obj) {
2039   assert(obj != NULL, "can't follow the content of NULL object");
2040   MarkSweep::follow_klass(obj->klass());
2041   InstanceKlass_OOP_MAP_ITERATE( \
2042     obj, \
2043     MarkSweep::mark_and_push(p), \
2044     assert_is_in_closed_subset)
2045 }
2046 
2047 #if INCLUDE_ALL_GCS
2048 void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
2049                                         oop obj) {
2050   assert(obj != NULL, "can't follow the content of NULL object");
2051   PSParallelCompact::follow_klass(cm, obj->klass());
2052   // Only mark the header and let the scan of the meta-data mark
2053   // everything else.
2054   InstanceKlass_OOP_MAP_ITERATE( \
2055     obj, \
2056     PSParallelCompact::mark_and_push(cm, p), \
2057     assert_is_in)
2058 }
2059 #endif // INCLUDE_ALL_GCS
2060 
2061 // closure's do_metadata() method dictates whether the given closure should be
2062 // applied to the klass ptr in the object header.
2063 
2064 #define if_do_metadata_checked(closure, nv_suffix)                    \
2065   /* Make sure the non-virtual and the virtual versions match. */     \
2066   assert(closure->do_metadata##nv_suffix() == closure->do_metadata(), \
2067       "Inconsistency in do_metadata");                                \
2068   if (closure->do_metadata##nv_suffix())
2069 
2070 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)        \
2071                                                                              \
2072 int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
2073   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2074   /* header */                                                          \
2075   if_do_metadata_checked(closure, nv_suffix) {                          \
2076     closure->do_klass##nv_suffix(obj->klass());                         \
2077   }                                                                     \
2078   InstanceKlass_OOP_MAP_ITERATE(                                        \
2079     obj,                                                                \
2080     SpecializationStats::                                               \
2081       record_do_oop_call##nv_suffix(SpecializationStats::ik);           \
2082     (closure)->do_oop##nv_suffix(p),                                    \
2083     assert_is_in_closed_subset)                                         \
2084   return size_helper();                                                 \
2085 }
2086 
2087 #if INCLUDE_ALL_GCS
2088 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
2089                                                                                 \
2090 int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj,                \
2091                                               OopClosureType* closure) {        \
2092   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
2093   /* header */                                                                  \
2094   if_do_metadata_checked(closure, nv_suffix) {                                  \
2095     closure->do_klass##nv_suffix(obj->klass());                                 \
2096   }                                                                             \
2097   /* instance variables */                                                      \
2098   InstanceKlass_OOP_MAP_REVERSE_ITERATE(                                        \
2099     obj,                                                                        \
2100     SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
2101     (closure)->do_oop##nv_suffix(p),                                            \
2102     assert_is_in_closed_subset)                                                 \
2103    return size_helper();                                                        \
2104 }
2105 #endif // INCLUDE_ALL_GCS
2106 
2107 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
2108                                                                         \
2109 int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj,              \
2110                                                   OopClosureType* closure, \
2111                                                   MemRegion mr) {          \
2112   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2113   if_do_metadata_checked(closure, nv_suffix) {                           \
2114     if (mr.contains(obj)) {                                              \
2115       closure->do_klass##nv_suffix(obj->klass());                        \
2116     }                                                                    \
2117   }                                                                      \
2118   InstanceKlass_BOUNDED_OOP_MAP_ITERATE(                                 \
2119     obj, mr.start(), mr.end(),                                           \
2120     (closure)->do_oop##nv_suffix(p),                                     \
2121     assert_is_in_closed_subset)                                          \
2122   return size_helper();                                                  \
2123 }
2124 
2125 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2126 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2127 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2128 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2129 #if INCLUDE_ALL_GCS
2130 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2131 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2132 #endif // INCLUDE_ALL_GCS
2133 
2134 int InstanceKlass::oop_adjust_pointers(oop obj) {
2135   int size = size_helper();
2136   InstanceKlass_OOP_MAP_ITERATE( \
2137     obj, \
2138     MarkSweep::adjust_pointer(p), \
2139     assert_is_in)
2140   MarkSweep::adjust_klass(obj->klass());
2141   return size;
2142 }
2143 
2144 #if INCLUDE_ALL_GCS
2145 void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
2146   InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2147     obj, \
2148     if (PSScavenge::should_scavenge(p)) { \
2149       pm->claim_or_forward_depth(p); \
2150     }, \
2151     assert_nothing )
2152 }
2153 
2154 int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
2155   int size = size_helper();
2156   InstanceKlass_OOP_MAP_ITERATE( \
2157     obj, \
2158     PSParallelCompact::adjust_pointer(p), \
2159     assert_is_in)
2160   obj->update_header(cm);
2161   return size;
2162 }
2163 
2164 #endif // INCLUDE_ALL_GCS
2165 
2166 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
2167   assert(is_loader_alive(is_alive), "this klass should be live");
2168   if (is_interface()) {
2169     if (ClassUnloading) {
2170       Klass* impl = implementor();
2171       if (impl != NULL) {
2172         if (!impl->is_loader_alive(is_alive)) {
2173           // remove this guy
2174           *adr_implementor() = NULL;
2175         }
2176       }
2177     }
2178   }
2179 }
2180 
2181 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
2182 #ifdef COMPILER2
2183   // Currently only used by C2.
2184   for (int m = 0; m < methods()->length(); m++) {
2185     MethodData* mdo = methods()->at(m)->method_data();
2186     if (mdo != NULL) {
2187       for (ProfileData* data = mdo->first_data();
2188            mdo->is_valid(data);
2189            data = mdo->next_data(data)) {
2190         data->clean_weak_klass_links(is_alive);
2191       }
2192     }
2193   }
2194 #else
2195 #ifdef ASSERT
2196   // Verify that we haven't started to use MDOs for C1.
2197   for (int m = 0; m < methods()->length(); m++) {
2198     MethodData* mdo = methods()->at(m)->method_data();
2199     assert(mdo == NULL, "Didn't expect C1 to use MDOs");
2200   }
2201 #endif // ASSERT
2202 #endif // !COMPILER2
2203 }
2204 
2205 
2206 static void remove_unshareable_in_class(Klass* k) {
2207   // remove klass's unshareable info
2208   k->remove_unshareable_info();
2209 }
2210 
2211 void InstanceKlass::remove_unshareable_info() {
2212   Klass::remove_unshareable_info();
2213   // Unlink the class
2214   if (is_linked()) {
2215     unlink_class();
2216   }
2217   init_implementor();
2218 
2219   constants()->remove_unshareable_info();
2220 
2221   for (int i = 0; i < methods()->length(); i++) {
2222     Method* m = methods()->at(i);
2223     m->remove_unshareable_info();
2224   }
2225 
2226   // Need to reinstate when reading back the class.
2227   set_init_lock(NULL);
2228 
2229   // do array classes also.
2230   array_klasses_do(remove_unshareable_in_class);
2231 }
2232 
2233 void restore_unshareable_in_class(Klass* k, TRAPS) {
2234   k->restore_unshareable_info(CHECK);
2235 }
2236 
2237 void InstanceKlass::restore_unshareable_info(TRAPS) {
2238   Klass::restore_unshareable_info(CHECK);
2239   instanceKlassHandle ik(THREAD, this);
2240 
2241   Array<Method*>* methods = ik->methods();
2242   int num_methods = methods->length();
2243   for (int index2 = 0; index2 < num_methods; ++index2) {
2244     methodHandle m(THREAD, methods->at(index2));
2245     m()->link_method(m, CHECK);
2246     // restore method's vtable by calling a virtual function
2247     m->restore_vtable();
2248   }
2249   if (JvmtiExport::has_redefined_a_class()) {
2250     // Reinitialize vtable because RedefineClasses may have changed some
2251     // entries in this vtable for super classes so the CDS vtable might
2252     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2253     // vtables in the shared system dictionary, only the main one.
2254     // It also redefines the itable too so fix that too.
2255     ResourceMark rm(THREAD);
2256     ik->vtable()->initialize_vtable(false, CHECK);
2257     ik->itable()->initialize_itable(false, CHECK);
2258   }
2259 
2260   // Allocate a simple java object for a lock.
2261   // This needs to be a java object because during class initialization
2262   // it can be held across a java call.
2263   typeArrayOop r = oopFactory::new_typeArray(T_INT, 0, CHECK);
2264   Handle h(THREAD, (oop)r);
2265   ik->set_init_lock(h());
2266 
2267   // restore constant pool resolved references
2268   ik->constants()->restore_unshareable_info(CHECK);
2269 
2270   ik->array_klasses_do(restore_unshareable_in_class, CHECK);
2271 }
2272 
2273 static void clear_all_breakpoints(Method* m) {
2274   m->clear_all_breakpoints();
2275 }
2276 
2277 void InstanceKlass::release_C_heap_structures() {
2278   // Deallocate oop map cache
2279   if (_oop_map_cache != NULL) {
2280     delete _oop_map_cache;
2281     _oop_map_cache = NULL;
2282   }
2283 
2284   // Deallocate JNI identifiers for jfieldIDs
2285   JNIid::deallocate(jni_ids());
2286   set_jni_ids(NULL);
2287 
2288   jmethodID* jmeths = methods_jmethod_ids_acquire();
2289   if (jmeths != (jmethodID*)NULL) {
2290     release_set_methods_jmethod_ids(NULL);
2291     FreeHeap(jmeths);
2292   }
2293 
2294   int* indices = methods_cached_itable_indices_acquire();
2295   if (indices != (int*)NULL) {
2296     release_set_methods_cached_itable_indices(NULL);
2297     FreeHeap(indices);
2298   }
2299 
2300   // release dependencies
2301   nmethodBucket* b = _dependencies;
2302   _dependencies = NULL;
2303   while (b != NULL) {
2304     nmethodBucket* next = b->next();
2305     delete b;
2306     b = next;
2307   }
2308 
2309   // Deallocate breakpoint records
2310   if (breakpoints() != 0x0) {
2311     methods_do(clear_all_breakpoints);
2312     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2313   }
2314 
2315   // deallocate information about previous versions
2316   if (_previous_versions != NULL) {
2317     for (int i = _previous_versions->length() - 1; i >= 0; i--) {
2318       PreviousVersionNode * pv_node = _previous_versions->at(i);
2319       delete pv_node;
2320     }
2321     delete _previous_versions;
2322     _previous_versions = NULL;
2323   }
2324 
2325   // deallocate the cached class file
2326   if (_cached_class_file_bytes != NULL) {
2327     os::free(_cached_class_file_bytes, mtClass);
2328     _cached_class_file_bytes = NULL;
2329     _cached_class_file_len = 0;
2330   }
2331 
2332   // Decrement symbol reference counts associated with the unloaded class.
2333   if (_name != NULL) _name->decrement_refcount();
2334   // unreference array name derived from this class name (arrays of an unloaded
2335   // class can't be referenced anymore).
2336   if (_array_name != NULL)  _array_name->decrement_refcount();
2337   if (_source_file_name != NULL) _source_file_name->decrement_refcount();
2338   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
2339 
2340   assert(_total_instanceKlass_count >= 1, "Sanity check");
2341   Atomic::dec(&_total_instanceKlass_count);
2342 }
2343 
2344 void InstanceKlass::set_source_file_name(Symbol* n) {
2345   _source_file_name = n;
2346   if (_source_file_name != NULL) _source_file_name->increment_refcount();
2347 }
2348 
2349 void InstanceKlass::set_source_debug_extension(char* array, int length) {
2350   if (array == NULL) {
2351     _source_debug_extension = NULL;
2352   } else {
2353     // Adding one to the attribute length in order to store a null terminator
2354     // character could cause an overflow because the attribute length is
2355     // already coded with an u4 in the classfile, but in practice, it's
2356     // unlikely to happen.
2357     assert((length+1) > length, "Overflow checking");
2358     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2359     for (int i = 0; i < length; i++) {
2360       sde[i] = array[i];
2361     }
2362     sde[length] = '\0';
2363     _source_debug_extension = sde;
2364   }
2365 }
2366 
2367 address InstanceKlass::static_field_addr(int offset) {
2368   return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + (intptr_t)java_mirror());
2369 }
2370 
2371 
2372 const char* InstanceKlass::signature_name() const {
2373   const char* src = (const char*) (name()->as_C_string());
2374   const int src_length = (int)strlen(src);
2375   char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
2376   int src_index = 0;
2377   int dest_index = 0;
2378   dest[dest_index++] = 'L';
2379   while (src_index < src_length) {
2380     dest[dest_index++] = src[src_index++];
2381   }
2382   dest[dest_index++] = ';';
2383   dest[dest_index] = '\0';
2384   return dest;
2385 }
2386 
2387 // different verisons of is_same_class_package
2388 bool InstanceKlass::is_same_class_package(Klass* class2) {
2389   Klass* class1 = this;
2390   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2391   Symbol* classname1 = class1->name();
2392 
2393   if (class2->oop_is_objArray()) {
2394     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2395   }
2396   oop classloader2;
2397   if (class2->oop_is_instance()) {
2398     classloader2 = InstanceKlass::cast(class2)->class_loader();
2399   } else {
2400     assert(class2->oop_is_typeArray(), "should be type array");
2401     classloader2 = NULL;
2402   }
2403   Symbol* classname2 = class2->name();
2404 
2405   return InstanceKlass::is_same_class_package(classloader1, classname1,
2406                                               classloader2, classname2);
2407 }
2408 
2409 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
2410   Klass* class1 = this;
2411   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2412   Symbol* classname1 = class1->name();
2413 
2414   return InstanceKlass::is_same_class_package(classloader1, classname1,
2415                                               classloader2, classname2);
2416 }
2417 
2418 // return true if two classes are in the same package, classloader
2419 // and classname information is enough to determine a class's package
2420 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
2421                                           oop class_loader2, Symbol* class_name2) {
2422   if (class_loader1 != class_loader2) {
2423     return false;
2424   } else if (class_name1 == class_name2) {
2425     return true;                // skip painful bytewise comparison
2426   } else {
2427     ResourceMark rm;
2428 
2429     // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
2430     // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
2431     // Otherwise, we just compare jbyte values between the strings.
2432     const jbyte *name1 = class_name1->base();
2433     const jbyte *name2 = class_name2->base();
2434 
2435     const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
2436     const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
2437 
2438     if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
2439       // One of the two doesn't have a package.  Only return true
2440       // if the other one also doesn't have a package.
2441       return last_slash1 == last_slash2;
2442     } else {
2443       // Skip over '['s
2444       if (*name1 == '[') {
2445         do {
2446           name1++;
2447         } while (*name1 == '[');
2448         if (*name1 != 'L') {
2449           // Something is terribly wrong.  Shouldn't be here.
2450           return false;
2451         }
2452       }
2453       if (*name2 == '[') {
2454         do {
2455           name2++;
2456         } while (*name2 == '[');
2457         if (*name2 != 'L') {
2458           // Something is terribly wrong.  Shouldn't be here.
2459           return false;
2460         }
2461       }
2462 
2463       // Check that package part is identical
2464       int length1 = last_slash1 - name1;
2465       int length2 = last_slash2 - name2;
2466 
2467       return UTF8::equal(name1, length1, name2, length2);
2468     }
2469   }
2470 }
2471 
2472 // Returns true iff super_method can be overridden by a method in targetclassname
2473 // See JSL 3rd edition 8.4.6.1
2474 // Assumes name-signature match
2475 // "this" is InstanceKlass of super_method which must exist
2476 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2477 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2478    // Private methods can not be overridden
2479    if (super_method->is_private()) {
2480      return false;
2481    }
2482    // If super method is accessible, then override
2483    if ((super_method->is_protected()) ||
2484        (super_method->is_public())) {
2485      return true;
2486    }
2487    // Package-private methods are not inherited outside of package
2488    assert(super_method->is_package_private(), "must be package private");
2489    return(is_same_class_package(targetclassloader(), targetclassname));
2490 }
2491 
2492 /* defined for now in jvm.cpp, for historical reasons *--
2493 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2494                                                      Symbol*& simple_name_result, TRAPS) {
2495   ...
2496 }
2497 */
2498 
2499 // tell if two classes have the same enclosing class (at package level)
2500 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2501                                                 Klass* class2_oop, TRAPS) {
2502   if (class2_oop == class1())                       return true;
2503   if (!class2_oop->oop_is_instance())  return false;
2504   instanceKlassHandle class2(THREAD, class2_oop);
2505 
2506   // must be in same package before we try anything else
2507   if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2508     return false;
2509 
2510   // As long as there is an outer1.getEnclosingClass,
2511   // shift the search outward.
2512   instanceKlassHandle outer1 = class1;
2513   for (;;) {
2514     // As we walk along, look for equalities between outer1 and class2.
2515     // Eventually, the walks will terminate as outer1 stops
2516     // at the top-level class around the original class.
2517     bool ignore_inner_is_member;
2518     Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2519                                                     CHECK_false);
2520     if (next == NULL)  break;
2521     if (next == class2())  return true;
2522     outer1 = instanceKlassHandle(THREAD, next);
2523   }
2524 
2525   // Now do the same for class2.
2526   instanceKlassHandle outer2 = class2;
2527   for (;;) {
2528     bool ignore_inner_is_member;
2529     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2530                                                     CHECK_false);
2531     if (next == NULL)  break;
2532     // Might as well check the new outer against all available values.
2533     if (next == class1())  return true;
2534     if (next == outer1())  return true;
2535     outer2 = instanceKlassHandle(THREAD, next);
2536   }
2537 
2538   // If by this point we have not found an equality between the
2539   // two classes, we know they are in separate package members.
2540   return false;
2541 }
2542 
2543 
2544 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2545   jint access = access_flags().as_int();
2546 
2547   // But check if it happens to be member class.
2548   instanceKlassHandle ik(THREAD, this);
2549   InnerClassesIterator iter(ik);
2550   for (; !iter.done(); iter.next()) {
2551     int ioff = iter.inner_class_info_index();
2552     // Inner class attribute can be zero, skip it.
2553     // Strange but true:  JVM spec. allows null inner class refs.
2554     if (ioff == 0) continue;
2555 
2556     // only look at classes that are already loaded
2557     // since we are looking for the flags for our self.
2558     Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2559     if ((ik->name() == inner_name)) {
2560       // This is really a member class.
2561       access = iter.inner_access_flags();
2562       break;
2563     }
2564   }
2565   // Remember to strip ACC_SUPER bit
2566   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2567 }
2568 
2569 jint InstanceKlass::jvmti_class_status() const {
2570   jint result = 0;
2571 
2572   if (is_linked()) {
2573     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2574   }
2575 
2576   if (is_initialized()) {
2577     assert(is_linked(), "Class status is not consistent");
2578     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2579   }
2580   if (is_in_error_state()) {
2581     result |= JVMTI_CLASS_STATUS_ERROR;
2582   }
2583   return result;
2584 }
2585 
2586 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2587   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2588   int method_table_offset_in_words = ioe->offset()/wordSize;
2589   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2590                        / itableOffsetEntry::size();
2591 
2592   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2593     // If the interface isn't implemented by the receiver class,
2594     // the VM should throw IncompatibleClassChangeError.
2595     if (cnt >= nof_interfaces) {
2596       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2597     }
2598 
2599     Klass* ik = ioe->interface_klass();
2600     if (ik == holder) break;
2601   }
2602 
2603   itableMethodEntry* ime = ioe->first_method_entry(this);
2604   Method* m = ime[index].method();
2605   if (m == NULL) {
2606     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2607   }
2608   return m;
2609 }
2610 
2611 // On-stack replacement stuff
2612 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2613   // only one compilation can be active
2614   NEEDS_CLEANUP
2615   // This is a short non-blocking critical region, so the no safepoint check is ok.
2616   OsrList_lock->lock_without_safepoint_check();
2617   assert(n->is_osr_method(), "wrong kind of nmethod");
2618   n->set_osr_link(osr_nmethods_head());
2619   set_osr_nmethods_head(n);
2620   // Raise the highest osr level if necessary
2621   if (TieredCompilation) {
2622     Method* m = n->method();
2623     m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2624   }
2625   // Remember to unlock again
2626   OsrList_lock->unlock();
2627 
2628   // Get rid of the osr methods for the same bci that have lower levels.
2629   if (TieredCompilation) {
2630     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2631       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2632       if (inv != NULL && inv->is_in_use()) {
2633         inv->make_not_entrant();
2634       }
2635     }
2636   }
2637 }
2638 
2639 
2640 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
2641   // This is a short non-blocking critical region, so the no safepoint check is ok.
2642   OsrList_lock->lock_without_safepoint_check();
2643   assert(n->is_osr_method(), "wrong kind of nmethod");
2644   nmethod* last = NULL;
2645   nmethod* cur  = osr_nmethods_head();
2646   int max_level = CompLevel_none;  // Find the max comp level excluding n
2647   Method* m = n->method();
2648   // Search for match
2649   while(cur != NULL && cur != n) {
2650     if (TieredCompilation) {
2651       // Find max level before n
2652       max_level = MAX2(max_level, cur->comp_level());
2653     }
2654     last = cur;
2655     cur = cur->osr_link();
2656   }
2657   nmethod* next = NULL;
2658   if (cur == n) {
2659     next = cur->osr_link();
2660     if (last == NULL) {
2661       // Remove first element
2662       set_osr_nmethods_head(next);
2663     } else {
2664       last->set_osr_link(next);
2665     }
2666   }
2667   n->set_osr_link(NULL);
2668   if (TieredCompilation) {
2669     cur = next;
2670     while (cur != NULL) {
2671       // Find max level after n
2672       max_level = MAX2(max_level, cur->comp_level());
2673       cur = cur->osr_link();
2674     }
2675     m->set_highest_osr_comp_level(max_level);
2676   }
2677   // Remember to unlock again
2678   OsrList_lock->unlock();
2679 }
2680 
2681 nmethod* InstanceKlass::lookup_osr_nmethod(Method* const m, int bci, int comp_level, bool match_level) const {
2682   // This is a short non-blocking critical region, so the no safepoint check is ok.
2683   OsrList_lock->lock_without_safepoint_check();
2684   nmethod* osr = osr_nmethods_head();
2685   nmethod* best = NULL;
2686   while (osr != NULL) {
2687     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2688     // There can be a time when a c1 osr method exists but we are waiting
2689     // for a c2 version. When c2 completes its osr nmethod we will trash
2690     // the c1 version and only be able to find the c2 version. However
2691     // while we overflow in the c1 code at back branches we don't want to
2692     // try and switch to the same code as we are already running
2693 
2694     if (osr->method() == m &&
2695         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2696       if (match_level) {
2697         if (osr->comp_level() == comp_level) {
2698           // Found a match - return it.
2699           OsrList_lock->unlock();
2700           return osr;
2701         }
2702       } else {
2703         if (best == NULL || (osr->comp_level() > best->comp_level())) {
2704           if (osr->comp_level() == CompLevel_highest_tier) {
2705             // Found the best possible - return it.
2706             OsrList_lock->unlock();
2707             return osr;
2708           }
2709           best = osr;
2710         }
2711       }
2712     }
2713     osr = osr->osr_link();
2714   }
2715   OsrList_lock->unlock();
2716   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2717     return best;
2718   }
2719   return NULL;
2720 }
2721 
2722 // -----------------------------------------------------------------------------------------------------
2723 // Printing
2724 
2725 #ifndef PRODUCT
2726 
2727 #define BULLET  " - "
2728 
2729 static const char* state_names[] = {
2730   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2731 };
2732 
2733 void InstanceKlass::print_on(outputStream* st) const {
2734   assert(is_klass(), "must be klass");
2735   Klass::print_on(st);
2736 
2737   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
2738   st->print(BULLET"klass size:        %d", size());                               st->cr();
2739   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
2740   st->print(BULLET"state:             "); st->print_cr(state_names[_init_state]);
2741   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
2742   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
2743   st->print(BULLET"sub:               ");
2744   Klass* sub = subklass();
2745   int n;
2746   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2747     if (n < MaxSubklassPrintSize) {
2748       sub->print_value_on(st);
2749       st->print("   ");
2750     }
2751   }
2752   if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
2753   st->cr();
2754 
2755   if (is_interface()) {
2756     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
2757     if (nof_implementors() == 1) {
2758       st->print_cr(BULLET"implementor:    ");
2759       st->print("   ");
2760       implementor()->print_value_on(st);
2761       st->cr();
2762     }
2763   }
2764 
2765   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2766   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
2767   if (Verbose) {
2768     Array<Method*>* method_array = methods();
2769     for(int i = 0; i < method_array->length(); i++) {
2770       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2771     }
2772   }
2773   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);       st->cr();
2774   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
2775   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2776   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
2777   if (class_loader_data() != NULL) {
2778     st->print(BULLET"class loader data:  ");
2779     class_loader_data()->print_value_on(st);
2780     st->cr();
2781   }
2782   st->print(BULLET"protection domain: "); ((InstanceKlass*)this)->protection_domain()->print_value_on(st); st->cr();
2783   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
2784   st->print(BULLET"signers:           "); signers()->print_value_on(st);               st->cr();
2785   st->print(BULLET"init_lock:         "); ((oop)init_lock())->print_value_on(st);             st->cr();
2786   if (source_file_name() != NULL) {
2787     st->print(BULLET"source file:       ");
2788     source_file_name()->print_value_on(st);
2789     st->cr();
2790   }
2791   if (source_debug_extension() != NULL) {
2792     st->print(BULLET"source debug extension:       ");
2793     st->print("%s", source_debug_extension());
2794     st->cr();
2795   }
2796   st->print(BULLET"annotations:       "); annotations()->print_value_on(st); st->cr();
2797   {
2798     ResourceMark rm;
2799     // PreviousVersionInfo objects returned via PreviousVersionWalker
2800     // contain a GrowableArray of handles. We have to clean up the
2801     // GrowableArray _after_ the PreviousVersionWalker destructor
2802     // has destroyed the handles.
2803     {
2804       bool have_pv = false;
2805       PreviousVersionWalker pvw((InstanceKlass*)this);
2806       for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
2807            pv_info != NULL; pv_info = pvw.next_previous_version()) {
2808         if (!have_pv)
2809           st->print(BULLET"previous version:  ");
2810         have_pv = true;
2811         pv_info->prev_constant_pool_handle()()->print_value_on(st);
2812       }
2813       if (have_pv)  st->cr();
2814     } // pvw is cleaned up
2815   } // rm is cleaned up
2816 
2817   if (generic_signature() != NULL) {
2818     st->print(BULLET"generic signature: ");
2819     generic_signature()->print_value_on(st);
2820     st->cr();
2821   }
2822   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
2823   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
2824   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable());  st->cr();
2825   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
2826   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2827   FieldPrinter print_static_field(st);
2828   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2829   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2830   FieldPrinter print_nonstatic_field(st);
2831   ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
2832 
2833   st->print(BULLET"non-static oop maps: ");
2834   OopMapBlock* map     = start_of_nonstatic_oop_maps();
2835   OopMapBlock* end_map = map + nonstatic_oop_map_count();
2836   while (map < end_map) {
2837     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2838     map++;
2839   }
2840   st->cr();
2841 }
2842 
2843 #endif //PRODUCT
2844 
2845 void InstanceKlass::print_value_on(outputStream* st) const {
2846   assert(is_klass(), "must be klass");
2847   name()->print_value_on(st);
2848 }
2849 
2850 #ifndef PRODUCT
2851 
2852 void FieldPrinter::do_field(fieldDescriptor* fd) {
2853   _st->print(BULLET);
2854    if (_obj == NULL) {
2855      fd->print_on(_st);
2856      _st->cr();
2857    } else {
2858      fd->print_on_for(_st, _obj);
2859      _st->cr();
2860    }
2861 }
2862 
2863 
2864 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
2865   Klass::oop_print_on(obj, st);
2866 
2867   if (this == SystemDictionary::String_klass()) {
2868     typeArrayOop value  = java_lang_String::value(obj);
2869     juint        offset = java_lang_String::offset(obj);
2870     juint        length = java_lang_String::length(obj);
2871     if (value != NULL &&
2872         value->is_typeArray() &&
2873         offset          <= (juint) value->length() &&
2874         offset + length <= (juint) value->length()) {
2875       st->print(BULLET"string: ");
2876       Handle h_obj(obj);
2877       java_lang_String::print(h_obj, st);
2878       st->cr();
2879       if (!WizardMode)  return;  // that is enough
2880     }
2881   }
2882 
2883   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
2884   FieldPrinter print_field(st, obj);
2885   do_nonstatic_fields(&print_field);
2886 
2887   if (this == SystemDictionary::Class_klass()) {
2888     st->print(BULLET"signature: ");
2889     java_lang_Class::print_signature(obj, st);
2890     st->cr();
2891     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
2892     st->print(BULLET"fake entry for mirror: ");
2893     mirrored_klass->print_value_on_maybe_null(st);
2894     st->cr();
2895     Klass* array_klass = java_lang_Class::array_klass(obj);
2896     st->print(BULLET"fake entry for array: ");
2897     array_klass->print_value_on_maybe_null(st);
2898     st->cr();
2899     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
2900     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
2901     Klass* real_klass = java_lang_Class::as_Klass(obj);
2902     if (real_klass != NULL && real_klass->oop_is_instance()) {
2903       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
2904     }
2905   } else if (this == SystemDictionary::MethodType_klass()) {
2906     st->print(BULLET"signature: ");
2907     java_lang_invoke_MethodType::print_signature(obj, st);
2908     st->cr();
2909   }
2910 }
2911 
2912 #endif //PRODUCT
2913 
2914 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
2915   st->print("a ");
2916   name()->print_value_on(st);
2917   obj->print_address_on(st);
2918   if (this == SystemDictionary::String_klass()
2919       && java_lang_String::value(obj) != NULL) {
2920     ResourceMark rm;
2921     int len = java_lang_String::length(obj);
2922     int plen = (len < 24 ? len : 12);
2923     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
2924     st->print(" = \"%s\"", str);
2925     if (len > plen)
2926       st->print("...[%d]", len);
2927   } else if (this == SystemDictionary::Class_klass()) {
2928     Klass* k = java_lang_Class::as_Klass(obj);
2929     st->print(" = ");
2930     if (k != NULL) {
2931       k->print_value_on(st);
2932     } else {
2933       const char* tname = type2name(java_lang_Class::primitive_type(obj));
2934       st->print("%s", tname ? tname : "type?");
2935     }
2936   } else if (this == SystemDictionary::MethodType_klass()) {
2937     st->print(" = ");
2938     java_lang_invoke_MethodType::print_signature(obj, st);
2939   } else if (java_lang_boxing_object::is_instance(obj)) {
2940     st->print(" = ");
2941     java_lang_boxing_object::print(obj, st);
2942   } else if (this == SystemDictionary::LambdaForm_klass()) {
2943     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
2944     if (vmentry != NULL) {
2945       st->print(" => ");
2946       vmentry->print_value_on(st);
2947     }
2948   } else if (this == SystemDictionary::MemberName_klass()) {
2949     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
2950     if (vmtarget != NULL) {
2951       st->print(" = ");
2952       vmtarget->print_value_on(st);
2953     } else {
2954       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
2955       st->print(".");
2956       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
2957     }
2958   }
2959 }
2960 
2961 const char* InstanceKlass::internal_name() const {
2962   return external_name();
2963 }
2964 
2965 #if INCLUDE_SERVICES
2966 // Size Statistics
2967 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
2968   Klass::collect_statistics(sz);
2969 
2970   sz->_inst_size  = HeapWordSize * size_helper();
2971   sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
2972   sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
2973   sz->_nonstatic_oopmap_bytes = HeapWordSize *
2974         ((is_interface() || is_anonymous()) ?
2975          align_object_offset(nonstatic_oop_map_size()) :
2976          nonstatic_oop_map_size());
2977 
2978   int n = 0;
2979   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
2980   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
2981   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
2982   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
2983   n += (sz->_signers_bytes               = sz->count_array(signers()));
2984   n += (sz->_fields_bytes                = sz->count_array(fields()));
2985   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
2986   sz->_ro_bytes += n;
2987 
2988   const ConstantPool* cp = constants();
2989   if (cp) {
2990     cp->collect_statistics(sz);
2991   }
2992 
2993   const Annotations* anno = annotations();
2994   if (anno) {
2995     anno->collect_statistics(sz);
2996   }
2997 
2998   const Array<Method*>* methods_array = methods();
2999   if (methods()) {
3000     for (int i = 0; i < methods_array->length(); i++) {
3001       Method* method = methods_array->at(i);
3002       if (method) {
3003         sz->_method_count ++;
3004         method->collect_statistics(sz);
3005       }
3006     }
3007   }
3008 }
3009 #endif // INCLUDE_SERVICES
3010 
3011 // Verification
3012 
3013 class VerifyFieldClosure: public OopClosure {
3014  protected:
3015   template <class T> void do_oop_work(T* p) {
3016     oop obj = oopDesc::load_decode_heap_oop(p);
3017     if (!obj->is_oop_or_null()) {
3018       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
3019       Universe::print();
3020       guarantee(false, "boom");
3021     }
3022   }
3023  public:
3024   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3025   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3026 };
3027 
3028 void InstanceKlass::verify_on(outputStream* st) {
3029   Klass::verify_on(st);
3030   Thread *thread = Thread::current();
3031 
3032 #ifndef PRODUCT
3033   // Avoid redundant verifies
3034   if (_verify_count == Universe::verify_count()) return;
3035   _verify_count = Universe::verify_count();
3036 #endif
3037   // Verify that klass is present in SystemDictionary
3038   if (is_loaded() && !is_anonymous()) {
3039     Symbol* h_name = name();
3040     SystemDictionary::verify_obj_klass_present(h_name, class_loader_data());
3041   }
3042 
3043   // Verify static fields
3044   VerifyFieldClosure blk;
3045 
3046   // Verify vtables
3047   if (is_linked()) {
3048     ResourceMark rm(thread);
3049     // $$$ This used to be done only for m/s collections.  Doing it
3050     // always seemed a valid generalization.  (DLD -- 6/00)
3051     vtable()->verify(st);
3052   }
3053 
3054   // Verify first subklass
3055   if (subklass_oop() != NULL) {
3056     guarantee(subklass_oop()->is_metadata(), "should be in metaspace");
3057     guarantee(subklass_oop()->is_klass(), "should be klass");
3058   }
3059 
3060   // Verify siblings
3061   Klass* super = this->super();
3062   Klass* sib = next_sibling();
3063   if (sib != NULL) {
3064     if (sib == this) {
3065       fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
3066     }
3067 
3068     guarantee(sib->is_metadata(), "should be in metaspace");
3069     guarantee(sib->is_klass(), "should be klass");
3070     guarantee(sib->super() == super, "siblings should have same superklass");
3071   }
3072 
3073   // Verify implementor fields
3074   Klass* im = implementor();
3075   if (im != NULL) {
3076     guarantee(is_interface(), "only interfaces should have implementor set");
3077     guarantee(im->is_klass(), "should be klass");
3078     guarantee(!im->is_interface() || im == this,
3079       "implementors cannot be interfaces");
3080   }
3081 
3082   // Verify local interfaces
3083   if (local_interfaces()) {
3084     Array<Klass*>* local_interfaces = this->local_interfaces();
3085     for (int j = 0; j < local_interfaces->length(); j++) {
3086       Klass* e = local_interfaces->at(j);
3087       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3088     }
3089   }
3090 
3091   // Verify transitive interfaces
3092   if (transitive_interfaces() != NULL) {
3093     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3094     for (int j = 0; j < transitive_interfaces->length(); j++) {
3095       Klass* e = transitive_interfaces->at(j);
3096       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3097     }
3098   }
3099 
3100   // Verify methods
3101   if (methods() != NULL) {
3102     Array<Method*>* methods = this->methods();
3103     for (int j = 0; j < methods->length(); j++) {
3104       guarantee(methods->at(j)->is_metadata(), "should be in metaspace");
3105       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3106     }
3107     for (int j = 0; j < methods->length() - 1; j++) {
3108       Method* m1 = methods->at(j);
3109       Method* m2 = methods->at(j + 1);
3110       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3111     }
3112   }
3113 
3114   // Verify method ordering
3115   if (method_ordering() != NULL) {
3116     Array<int>* method_ordering = this->method_ordering();
3117     int length = method_ordering->length();
3118     if (JvmtiExport::can_maintain_original_method_order() ||
3119         (UseSharedSpaces && length != 0)) {
3120       guarantee(length == methods()->length(), "invalid method ordering length");
3121       jlong sum = 0;
3122       for (int j = 0; j < length; j++) {
3123         int original_index = method_ordering->at(j);
3124         guarantee(original_index >= 0, "invalid method ordering index");
3125         guarantee(original_index < length, "invalid method ordering index");
3126         sum += original_index;
3127       }
3128       // Verify sum of indices 0,1,...,length-1
3129       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3130     } else {
3131       guarantee(length == 0, "invalid method ordering length");
3132     }
3133   }
3134 
3135   // Verify JNI static field identifiers
3136   if (jni_ids() != NULL) {
3137     jni_ids()->verify(this);
3138   }
3139 
3140   // Verify other fields
3141   if (array_klasses() != NULL) {
3142     guarantee(array_klasses()->is_metadata(), "should be in metaspace");
3143     guarantee(array_klasses()->is_klass(), "should be klass");
3144   }
3145   if (constants() != NULL) {
3146     guarantee(constants()->is_metadata(), "should be in metaspace");
3147     guarantee(constants()->is_constantPool(), "should be constant pool");
3148   }
3149   if (protection_domain() != NULL) {
3150     guarantee(protection_domain()->is_oop(), "should be oop");
3151   }
3152   if (host_klass() != NULL) {
3153     guarantee(host_klass()->is_metadata(), "should be in metaspace");
3154     guarantee(host_klass()->is_klass(), "should be klass");
3155   }
3156   if (signers() != NULL) {
3157     guarantee(signers()->is_objArray(), "should be obj array");
3158   }
3159 }
3160 
3161 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3162   Klass::oop_verify_on(obj, st);
3163   VerifyFieldClosure blk;
3164   obj->oop_iterate_no_header(&blk);
3165 }
3166 
3167 
3168 // JNIid class for jfieldIDs only
3169 // Note to reviewers:
3170 // These JNI functions are just moved over to column 1 and not changed
3171 // in the compressed oops workspace.
3172 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3173   _holder = holder;
3174   _offset = offset;
3175   _next = next;
3176   debug_only(_is_static_field_id = false;)
3177 }
3178 
3179 
3180 JNIid* JNIid::find(int offset) {
3181   JNIid* current = this;
3182   while (current != NULL) {
3183     if (current->offset() == offset) return current;
3184     current = current->next();
3185   }
3186   return NULL;
3187 }
3188 
3189 void JNIid::deallocate(JNIid* current) {
3190   while (current != NULL) {
3191     JNIid* next = current->next();
3192     delete current;
3193     current = next;
3194   }
3195 }
3196 
3197 
3198 void JNIid::verify(Klass* holder) {
3199   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3200   int end_field_offset;
3201   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3202 
3203   JNIid* current = this;
3204   while (current != NULL) {
3205     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3206 #ifdef ASSERT
3207     int o = current->offset();
3208     if (current->is_static_field_id()) {
3209       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3210     }
3211 #endif
3212     current = current->next();
3213   }
3214 }
3215 
3216 
3217 #ifdef ASSERT
3218 void InstanceKlass::set_init_state(ClassState state) {
3219   bool good_state = is_shared() ? (_init_state <= state)
3220                                                : (_init_state < state);
3221   assert(good_state || state == allocated, "illegal state transition");
3222   _init_state = (u1)state;
3223 }
3224 #endif
3225 
3226 
3227 // RedefineClasses() support for previous versions:
3228 
3229 // Purge previous versions
3230 static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
3231   if (ik->previous_versions() != NULL) {
3232     // This klass has previous versions so see what we can cleanup
3233     // while it is safe to do so.
3234 
3235     int deleted_count = 0;    // leave debugging breadcrumbs
3236     int live_count = 0;
3237     ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
3238                        ClassLoaderData::the_null_class_loader_data() :
3239                        ik->class_loader_data();
3240 
3241     // RC_TRACE macro has an embedded ResourceMark
3242     RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
3243       ik->external_name(), ik->previous_versions()->length()));
3244 
3245     for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
3246       // check the previous versions array
3247       PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
3248       ConstantPool* cp_ref = pv_node->prev_constant_pool();
3249       assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
3250 
3251       ConstantPool* pvcp = cp_ref;
3252       if (!pvcp->on_stack()) {
3253         // If the constant pool isn't on stack, none of the methods
3254         // are executing.  Delete all the methods, the constant pool and
3255         // and this previous version node.
3256         GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3257         if (method_refs != NULL) {
3258           for (int j = method_refs->length() - 1; j >= 0; j--) {
3259             Method* method = method_refs->at(j);
3260             assert(method != NULL, "method ref was unexpectedly cleared");
3261             method_refs->remove_at(j);
3262             // method will be freed with associated class.
3263           }
3264         }
3265         // Remove the constant pool
3266         delete pv_node;
3267         // Since we are traversing the array backwards, we don't have to
3268         // do anything special with the index.
3269         ik->previous_versions()->remove_at(i);
3270         deleted_count++;
3271         continue;
3272       } else {
3273         RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
3274         assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3275         guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3276         live_count++;
3277       }
3278 
3279       // At least one method is live in this previous version, clean out
3280       // the others or mark them as obsolete.
3281       GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3282       if (method_refs != NULL) {
3283         RC_TRACE(0x00000200, ("purge: previous methods length=%d",
3284           method_refs->length()));
3285         for (int j = method_refs->length() - 1; j >= 0; j--) {
3286           Method* method = method_refs->at(j);
3287           assert(method != NULL, "method ref was unexpectedly cleared");
3288 
3289           // Remove the emcp method if it's not executing
3290           // If it's been made obsolete by a redefinition of a non-emcp
3291           // method, mark it as obsolete but leave it to clean up later.
3292           if (!method->on_stack()) {
3293             method_refs->remove_at(j);
3294           } else if (emcp_method_count == 0) {
3295             method->set_is_obsolete();
3296           } else {
3297             // RC_TRACE macro has an embedded ResourceMark
3298             RC_TRACE(0x00000200,
3299               ("purge: %s(%s): prev method @%d in version @%d is alive",
3300               method->name()->as_C_string(),
3301               method->signature()->as_C_string(), j, i));
3302           }
3303         }
3304       }
3305     }
3306     assert(ik->previous_versions()->length() == live_count, "sanity check");
3307     RC_TRACE(0x00000200,
3308       ("purge: previous version stats: live=%d, deleted=%d", live_count,
3309       deleted_count));
3310   }
3311 }
3312 
3313 // External interface for use during class unloading.
3314 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
3315   // Call with >0 emcp methods since they are not currently being redefined.
3316   purge_previous_versions_internal(ik, 1);
3317 }
3318 
3319 
3320 // Potentially add an information node that contains pointers to the
3321 // interesting parts of the previous version of the_class.
3322 // This is also where we clean out any unused references.
3323 // Note that while we delete nodes from the _previous_versions
3324 // array, we never delete the array itself until the klass is
3325 // unloaded. The has_been_redefined() query depends on that fact.
3326 //
3327 void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
3328        BitMap* emcp_methods, int emcp_method_count) {
3329   assert(Thread::current()->is_VM_thread(),
3330          "only VMThread can add previous versions");
3331 
3332   if (_previous_versions == NULL) {
3333     // This is the first previous version so make some space.
3334     // Start with 2 elements under the assumption that the class
3335     // won't be redefined much.
3336     _previous_versions =  new (ResourceObj::C_HEAP, mtClass)
3337                             GrowableArray<PreviousVersionNode *>(2, true);
3338   }
3339 
3340   ConstantPool* cp_ref = ikh->constants();
3341 
3342   // RC_TRACE macro has an embedded ResourceMark
3343   RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
3344                         "on_stack=%d",
3345     ikh->external_name(), _previous_versions->length(), emcp_method_count,
3346     cp_ref->on_stack()));
3347 
3348   // If the constant pool for this previous version of the class
3349   // is not marked as being on the stack, then none of the methods
3350   // in this previous version of the class are on the stack so
3351   // we don't need to create a new PreviousVersionNode. However,
3352   // we still need to examine older previous versions below.
3353   Array<Method*>* old_methods = ikh->methods();
3354 
3355   if (cp_ref->on_stack()) {
3356   PreviousVersionNode * pv_node = NULL;
3357   if (emcp_method_count == 0) {
3358       // non-shared ConstantPool gets a reference
3359       pv_node = new PreviousVersionNode(cp_ref, !cp_ref->is_shared(), NULL);
3360     RC_TRACE(0x00000400,
3361         ("add: all methods are obsolete; flushing any EMCP refs"));
3362   } else {
3363     int local_count = 0;
3364       GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
3365         GrowableArray<Method*>(emcp_method_count, true);
3366     for (int i = 0; i < old_methods->length(); i++) {
3367       if (emcp_methods->at(i)) {
3368           // this old method is EMCP. Save it only if it's on the stack
3369           Method* old_method = old_methods->at(i);
3370           if (old_method->on_stack()) {
3371             method_refs->append(old_method);
3372           }
3373         if (++local_count >= emcp_method_count) {
3374           // no more EMCP methods so bail out now
3375           break;
3376         }
3377       }
3378     }
3379       // non-shared ConstantPool gets a reference
3380       pv_node = new PreviousVersionNode(cp_ref, !cp_ref->is_shared(), method_refs);
3381     }
3382     // append new previous version.
3383   _previous_versions->append(pv_node);
3384   }
3385 
3386   // Since the caller is the VMThread and we are at a safepoint, this
3387   // is a good time to clear out unused references.
3388 
3389   RC_TRACE(0x00000400, ("add: previous version length=%d",
3390     _previous_versions->length()));
3391 
3392   // Purge previous versions not executing on the stack
3393   purge_previous_versions_internal(this, emcp_method_count);
3394 
3395   int obsolete_method_count = old_methods->length() - emcp_method_count;
3396 
3397   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3398       _previous_versions->length() > 0) {
3399     // We have a mix of obsolete and EMCP methods so we have to
3400     // clear out any matching EMCP method entries the hard way.
3401     int local_count = 0;
3402     for (int i = 0; i < old_methods->length(); i++) {
3403       if (!emcp_methods->at(i)) {
3404         // only obsolete methods are interesting
3405         Method* old_method = old_methods->at(i);
3406         Symbol* m_name = old_method->name();
3407         Symbol* m_signature = old_method->signature();
3408 
3409         // we might not have added the last entry
3410         for (int j = _previous_versions->length() - 1; j >= 0; j--) {
3411           // check the previous versions array for non executing obsolete methods
3412           PreviousVersionNode * pv_node = _previous_versions->at(j);
3413 
3414           GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3415           if (method_refs == NULL) {
3416             // We have run into a PreviousVersion generation where
3417             // all methods were made obsolete during that generation's
3418             // RedefineClasses() operation. At the time of that
3419             // operation, all EMCP methods were flushed so we don't
3420             // have to go back any further.
3421             //
3422             // A NULL method_refs is different than an empty method_refs.
3423             // We cannot infer any optimizations about older generations
3424             // from an empty method_refs for the current generation.
3425             break;
3426           }
3427 
3428           for (int k = method_refs->length() - 1; k >= 0; k--) {
3429             Method* method = method_refs->at(k);
3430 
3431             if (!method->is_obsolete() &&
3432                 method->name() == m_name &&
3433                 method->signature() == m_signature) {
3434               // The current RedefineClasses() call has made all EMCP
3435               // versions of this method obsolete so mark it as obsolete
3436               // and remove the reference.
3437               RC_TRACE(0x00000400,
3438                 ("add: %s(%s): flush obsolete method @%d in version @%d",
3439                 m_name->as_C_string(), m_signature->as_C_string(), k, j));
3440 
3441               method->set_is_obsolete();
3442               // Leave obsolete methods on the previous version list to
3443               // clean up later.
3444               break;
3445             }
3446           }
3447 
3448           // The previous loop may not find a matching EMCP method, but
3449           // that doesn't mean that we can optimize and not go any
3450           // further back in the PreviousVersion generations. The EMCP
3451           // method for this generation could have already been deleted,
3452           // but there still may be an older EMCP method that has not
3453           // been deleted.
3454         }
3455 
3456         if (++local_count >= obsolete_method_count) {
3457           // no more obsolete methods so bail out now
3458           break;
3459         }
3460       }
3461     }
3462   }
3463 } // end add_previous_version()
3464 
3465 
3466 // Determine if InstanceKlass has a previous version.
3467 bool InstanceKlass::has_previous_version() const {
3468   return (_previous_versions != NULL && _previous_versions->length() > 0);
3469 } // end has_previous_version()
3470 
3471 
3472 Method* InstanceKlass::method_with_idnum(int idnum) {
3473   Method* m = NULL;
3474   if (idnum < methods()->length()) {
3475     m = methods()->at(idnum);
3476   }
3477   if (m == NULL || m->method_idnum() != idnum) {
3478     for (int index = 0; index < methods()->length(); ++index) {
3479       m = methods()->at(index);
3480       if (m->method_idnum() == idnum) {
3481         return m;
3482       }
3483     }
3484   }
3485   return m;
3486 }
3487 
3488 
3489 // Construct a PreviousVersionNode entry for the array hung off
3490 // the InstanceKlass.
3491 PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
3492   bool prev_cp_is_weak, GrowableArray<Method*>* prev_EMCP_methods) {
3493 
3494   _prev_constant_pool = prev_constant_pool;
3495   _prev_cp_is_weak = prev_cp_is_weak;
3496   _prev_EMCP_methods = prev_EMCP_methods;
3497 }
3498 
3499 
3500 // Destroy a PreviousVersionNode
3501 PreviousVersionNode::~PreviousVersionNode() {
3502   if (_prev_constant_pool != NULL) {
3503     _prev_constant_pool = NULL;
3504   }
3505 
3506   if (_prev_EMCP_methods != NULL) {
3507     delete _prev_EMCP_methods;
3508   }
3509 }
3510 
3511 
3512 // Construct a PreviousVersionInfo entry
3513 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
3514   _prev_constant_pool_handle = constantPoolHandle();  // NULL handle
3515   _prev_EMCP_method_handles = NULL;
3516 
3517   ConstantPool* cp = pv_node->prev_constant_pool();
3518   assert(cp != NULL, "constant pool ref was unexpectedly cleared");
3519   if (cp == NULL) {
3520     return;  // robustness
3521   }
3522 
3523   // make the ConstantPool* safe to return
3524   _prev_constant_pool_handle = constantPoolHandle(cp);
3525 
3526   GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3527   if (method_refs == NULL) {
3528     // the InstanceKlass did not have any EMCP methods
3529     return;
3530   }
3531 
3532   _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
3533 
3534   int n_methods = method_refs->length();
3535   for (int i = 0; i < n_methods; i++) {
3536     Method* method = method_refs->at(i);
3537     assert (method != NULL, "method has been cleared");
3538     if (method == NULL) {
3539       continue;  // robustness
3540     }
3541     // make the Method* safe to return
3542     _prev_EMCP_method_handles->append(methodHandle(method));
3543   }
3544 }
3545 
3546 
3547 // Destroy a PreviousVersionInfo
3548 PreviousVersionInfo::~PreviousVersionInfo() {
3549   // Since _prev_EMCP_method_handles is not C-heap allocated, we
3550   // don't have to delete it.
3551 }
3552 
3553 
3554 // Construct a helper for walking the previous versions array
3555 PreviousVersionWalker::PreviousVersionWalker(InstanceKlass *ik) {
3556   _previous_versions = ik->previous_versions();
3557   _current_index = 0;
3558   // _hm needs no initialization
3559   _current_p = NULL;
3560 }
3561 
3562 
3563 // Destroy a PreviousVersionWalker
3564 PreviousVersionWalker::~PreviousVersionWalker() {
3565   // Delete the current info just in case the caller didn't walk to
3566   // the end of the previous versions list. No harm if _current_p is
3567   // already NULL.
3568   delete _current_p;
3569 
3570   // When _hm is destroyed, all the Handles returned in
3571   // PreviousVersionInfo objects will be destroyed.
3572   // Also, after this destructor is finished it will be
3573   // safe to delete the GrowableArray allocated in the
3574   // PreviousVersionInfo objects.
3575 }
3576 
3577 
3578 // Return the interesting information for the next previous version
3579 // of the klass. Returns NULL if there are no more previous versions.
3580 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
3581   if (_previous_versions == NULL) {
3582     // no previous versions so nothing to return
3583     return NULL;
3584   }
3585 
3586   delete _current_p;  // cleanup the previous info for the caller
3587   _current_p = NULL;  // reset to NULL so we don't delete same object twice
3588 
3589   int length = _previous_versions->length();
3590 
3591   while (_current_index < length) {
3592     PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
3593     PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP, mtClass)
3594                                           PreviousVersionInfo(pv_node);
3595 
3596     constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
3597     assert (!cp_h.is_null(), "null cp found in previous version");
3598 
3599     // The caller will need to delete pv_info when they are done with it.
3600     _current_p = pv_info;
3601     return pv_info;
3602   }
3603 
3604   // all of the underlying nodes' info has been deleted
3605   return NULL;
3606 } // end next_previous_version()