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/jvmtiRedefineClasses.hpp"
  52 #include "prims/methodComparator.hpp"
  53 #include "runtime/fieldDescriptor.hpp"
  54 #include "runtime/handles.inline.hpp"
  55 #include "runtime/javaCalls.hpp"
  56 #include "runtime/mutexLocker.hpp"
  57 #include "runtime/thread.inline.hpp"
  58 #include "services/classLoadingService.hpp"
  59 #include "services/threadService.hpp"
  60 #include "utilities/dtrace.hpp"
  61 #include "utilities/macros.hpp"
  62 #if INCLUDE_ALL_GCS
  63 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
  64 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  65 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
  66 #include "gc_implementation/g1/g1RemSet.inline.hpp"
  67 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
  68 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
  69 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
  70 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
  71 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
  72 #include "oops/oop.pcgc.inline.hpp"
  73 #endif // INCLUDE_ALL_GCS
  74 #ifdef COMPILER1
  75 #include "c1/c1_Compiler.hpp"
  76 #endif
  77 
  78 #ifdef DTRACE_ENABLED
  79 
  80 #ifndef USDT2
  81 
  82 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
  83   char*, intptr_t, oop, intptr_t);
  84 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
  85   char*, intptr_t, oop, intptr_t, int);
  86 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
  87   char*, intptr_t, oop, intptr_t, int);
  88 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
  89   char*, intptr_t, oop, intptr_t, int);
  90 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
  91   char*, intptr_t, oop, intptr_t, int);
  92 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
  93   char*, intptr_t, oop, intptr_t, int);
  94 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
  95   char*, intptr_t, oop, intptr_t, int);
  96 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
  97   char*, intptr_t, oop, intptr_t, int);
  98 
  99 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
 100   {                                                              \
 101     char* data = NULL;                                           \
 102     int len = 0;                                                 \
 103     Symbol* name = (clss)->name();                               \
 104     if (name != NULL) {                                          \
 105       data = (char*)name->bytes();                               \
 106       len = name->utf8_length();                                 \
 107     }                                                            \
 108     HS_DTRACE_PROBE4(hotspot, class__initialization__##type,     \
 109       data, len, SOLARIS_ONLY((void *))(clss)->class_loader(), thread_type);           \
 110   }
 111 
 112 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
 113   {                                                              \
 114     char* data = NULL;                                           \
 115     int len = 0;                                                 \
 116     Symbol* name = (clss)->name();                               \
 117     if (name != NULL) {                                          \
 118       data = (char*)name->bytes();                               \
 119       len = name->utf8_length();                                 \
 120     }                                                            \
 121     HS_DTRACE_PROBE5(hotspot, class__initialization__##type,     \
 122       data, len, SOLARIS_ONLY((void *))(clss)->class_loader(), thread_type, wait);     \
 123   }
 124 #else /* USDT2 */
 125 
 126 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
 127 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
 128 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
 129 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
 130 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
 131 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
 132 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
 133 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
 134 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
 135   {                                                              \
 136     char* data = NULL;                                           \
 137     int len = 0;                                                 \
 138     Symbol* name = (clss)->name();                               \
 139     if (name != NULL) {                                          \
 140       data = (char*)name->bytes();                               \
 141       len = name->utf8_length();                                 \
 142     }                                                            \
 143     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 144       data, len, (clss)->class_loader(), thread_type);           \
 145   }
 146 
 147 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
 148   {                                                              \
 149     char* data = NULL;                                           \
 150     int len = 0;                                                 \
 151     Symbol* name = (clss)->name();                               \
 152     if (name != NULL) {                                          \
 153       data = (char*)name->bytes();                               \
 154       len = name->utf8_length();                                 \
 155     }                                                            \
 156     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 157       data, len, (clss)->class_loader(), thread_type, wait);     \
 158   }
 159 #endif /* USDT2 */
 160 
 161 #else //  ndef DTRACE_ENABLED
 162 
 163 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
 164 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
 165 
 166 #endif //  ndef DTRACE_ENABLED
 167 
 168 volatile int InstanceKlass::_total_instanceKlass_count = 0;
 169 
 170 InstanceKlass* InstanceKlass::allocate_instance_klass(
 171                                               ClassLoaderData* loader_data,
 172                                               int vtable_len,
 173                                               int itable_len,
 174                                               int static_field_size,
 175                                               int nonstatic_oop_map_size,
 176                                               ReferenceType rt,
 177                                               AccessFlags access_flags,
 178                                               Symbol* name,
 179                                               Klass* super_klass,
 180                                               bool is_anonymous,
 181                                               TRAPS) {
 182 
 183   int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
 184                                  access_flags.is_interface(), is_anonymous);
 185 
 186   // Allocation
 187   InstanceKlass* ik;
 188   if (rt == REF_NONE) {
 189     if (name == vmSymbols::java_lang_Class()) {
 190       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
 191         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 192         access_flags, is_anonymous);
 193     } else if (name == vmSymbols::java_lang_ClassLoader() ||
 194           (SystemDictionary::ClassLoader_klass_loaded() &&
 195           super_klass != NULL &&
 196           super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
 197       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
 198         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 199         access_flags, is_anonymous);
 200     } else {
 201       // normal class
 202       ik = new (loader_data, size, THREAD) InstanceKlass(
 203         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 204         access_flags, is_anonymous);
 205     }
 206   } else {
 207     // reference klass
 208     ik = new (loader_data, size, THREAD) InstanceRefKlass(
 209         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 210         access_flags, is_anonymous);
 211   }
 212 
 213   // Check for pending exception before adding to the loader data and incrementing
 214   // class count.  Can get OOM here.
 215   if (HAS_PENDING_EXCEPTION) {
 216     return NULL;
 217   }
 218 
 219   // Add all classes to our internal class loader list here,
 220   // including classes in the bootstrap (NULL) class loader.
 221   loader_data->add_class(ik);
 222 
 223   Atomic::inc(&_total_instanceKlass_count);
 224   return ik;
 225 }
 226 
 227 
 228 // copy method ordering from resource area to Metaspace
 229 void InstanceKlass::copy_method_ordering(intArray* m, TRAPS) {
 230   if (m != NULL) {
 231     // allocate a new array and copy contents (memcpy?)
 232     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
 233     for (int i = 0; i < m->length(); i++) {
 234       _method_ordering->at_put(i, m->at(i));
 235     }
 236   } else {
 237     _method_ordering = Universe::the_empty_int_array();
 238   }
 239 }
 240 
 241 // create a new array of vtable_indices for default methods
 242 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
 243   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
 244   assert(default_vtable_indices() == NULL, "only create once");
 245   set_default_vtable_indices(vtable_indices);
 246   return vtable_indices;
 247 }
 248 
 249 InstanceKlass::InstanceKlass(int vtable_len,
 250                              int itable_len,
 251                              int static_field_size,
 252                              int nonstatic_oop_map_size,
 253                              ReferenceType rt,
 254                              AccessFlags access_flags,
 255                              bool is_anonymous) {
 256   No_Safepoint_Verifier no_safepoint; // until k becomes parsable
 257 
 258   int iksize = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
 259                                    access_flags.is_interface(), is_anonymous);
 260 
 261   set_vtable_length(vtable_len);
 262   set_itable_length(itable_len);
 263   set_static_field_size(static_field_size);
 264   set_nonstatic_oop_map_size(nonstatic_oop_map_size);
 265   set_access_flags(access_flags);
 266   _misc_flags = 0;  // initialize to zero
 267   set_is_anonymous(is_anonymous);
 268   assert(size() == iksize, "wrong size for object");
 269 
 270   set_array_klasses(NULL);
 271   set_methods(NULL);
 272   set_method_ordering(NULL);
 273   set_default_methods(NULL);
 274   set_default_vtable_indices(NULL);
 275   set_local_interfaces(NULL);
 276   set_transitive_interfaces(NULL);
 277   init_implementor();
 278   set_fields(NULL, 0);
 279   set_constants(NULL);
 280   set_class_loader_data(NULL);
 281   set_source_file_name_index(0);
 282   set_source_debug_extension(NULL, 0);
 283   set_array_name(NULL);
 284   set_inner_classes(NULL);
 285   set_static_oop_field_count(0);
 286   set_nonstatic_field_size(0);
 287   set_is_marked_dependent(false);
 288   set_init_state(InstanceKlass::allocated);
 289   set_init_thread(NULL);
 290   set_reference_type(rt);
 291   set_oop_map_cache(NULL);
 292   set_jni_ids(NULL);
 293   set_osr_nmethods_head(NULL);
 294   set_breakpoints(NULL);
 295   init_previous_versions();
 296   set_generic_signature_index(0);
 297   release_set_methods_jmethod_ids(NULL);
 298   set_annotations(NULL);
 299   set_jvmti_cached_class_field_map(NULL);
 300   set_initial_method_idnum(0);
 301   _dependencies = NULL;
 302   set_jvmti_cached_class_field_map(NULL);
 303   set_cached_class_file(NULL);
 304   set_initial_method_idnum(0);
 305   set_minor_version(0);
 306   set_major_version(0);
 307   NOT_PRODUCT(_verify_count = 0;)
 308 
 309   // initialize the non-header words to zero
 310   intptr_t* p = (intptr_t*)this;
 311   for (int index = InstanceKlass::header_size(); index < iksize; index++) {
 312     p[index] = NULL_WORD;
 313   }
 314 
 315   // Set temporary value until parseClassFile updates it with the real instance
 316   // size.
 317   set_layout_helper(Klass::instance_layout_helper(0, true));
 318 }
 319 
 320 
 321 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 322                                        Array<Method*>* methods) {
 323   if (methods != NULL && methods != Universe::the_empty_method_array() &&
 324       !methods->is_shared()) {
 325     for (int i = 0; i < methods->length(); i++) {
 326       Method* method = methods->at(i);
 327       if (method == NULL) continue;  // maybe null if error processing
 328       // Only want to delete methods that are not executing for RedefineClasses.
 329       // The previous version will point to them so they're not totally dangling
 330       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 331       MetadataFactory::free_metadata(loader_data, method);
 332     }
 333     MetadataFactory::free_array<Method*>(loader_data, methods);
 334   }
 335 }
 336 
 337 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 338                                           Klass* super_klass,
 339                                           Array<Klass*>* local_interfaces,
 340                                           Array<Klass*>* transitive_interfaces) {
 341   // Only deallocate transitive interfaces if not empty, same as super class
 342   // or same as local interfaces.  See code in parseClassFile.
 343   Array<Klass*>* ti = transitive_interfaces;
 344   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
 345     // check that the interfaces don't come from super class
 346     Array<Klass*>* sti = (super_klass == NULL) ? NULL :
 347                     InstanceKlass::cast(super_klass)->transitive_interfaces();
 348     if (ti != sti && ti != NULL && !ti->is_shared()) {
 349       MetadataFactory::free_array<Klass*>(loader_data, ti);
 350     }
 351   }
 352 
 353   // local interfaces can be empty
 354   if (local_interfaces != Universe::the_empty_klass_array() &&
 355       local_interfaces != NULL && !local_interfaces->is_shared()) {
 356     MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
 357   }
 358 }
 359 
 360 // This function deallocates the metadata and C heap pointers that the
 361 // InstanceKlass points to.
 362 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 363 
 364   // Orphan the mirror first, CMS thinks it's still live.
 365   if (java_mirror() != NULL) {
 366     java_lang_Class::set_klass(java_mirror(), NULL);
 367   }
 368 
 369   // Need to take this class off the class loader data list.
 370   loader_data->remove_class(this);
 371 
 372   // The array_klass for this class is created later, after error handling.
 373   // For class redefinition, we keep the original class so this scratch class
 374   // doesn't have an array class.  Either way, assert that there is nothing
 375   // to deallocate.
 376   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
 377 
 378   // Release C heap allocated data that this might point to, which includes
 379   // reference counting symbol names.
 380   release_C_heap_structures();
 381 
 382   deallocate_methods(loader_data, methods());
 383   set_methods(NULL);
 384 
 385   if (method_ordering() != NULL &&
 386       method_ordering() != Universe::the_empty_int_array() &&
 387       !method_ordering()->is_shared()) {
 388     MetadataFactory::free_array<int>(loader_data, method_ordering());
 389   }
 390   set_method_ordering(NULL);
 391 
 392   // default methods can be empty
 393   if (default_methods() != NULL &&
 394       default_methods() != Universe::the_empty_method_array() &&
 395       !default_methods()->is_shared()) {
 396     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 397   }
 398   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 399   set_default_methods(NULL);
 400 
 401   // default methods vtable indices can be empty
 402   if (default_vtable_indices() != NULL &&
 403       !default_vtable_indices()->is_shared()) {
 404     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 405   }
 406   set_default_vtable_indices(NULL);
 407 
 408 
 409   // This array is in Klass, but remove it with the InstanceKlass since
 410   // this place would be the only caller and it can share memory with transitive
 411   // interfaces.
 412   if (secondary_supers() != NULL &&
 413       secondary_supers() != Universe::the_empty_klass_array() &&
 414       secondary_supers() != transitive_interfaces() &&
 415       !secondary_supers()->is_shared()) {
 416     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 417   }
 418   set_secondary_supers(NULL);
 419 
 420   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 421   set_transitive_interfaces(NULL);
 422   set_local_interfaces(NULL);
 423 
 424   if (fields() != NULL && !fields()->is_shared()) {
 425     MetadataFactory::free_array<jushort>(loader_data, fields());
 426   }
 427   set_fields(NULL, 0);
 428 
 429   // If a method from a redefined class is using this constant pool, don't
 430   // delete it, yet.  The new class's previous version will point to this.
 431   if (constants() != NULL) {
 432     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 433     if (!constants()->is_shared()) {
 434       MetadataFactory::free_metadata(loader_data, constants());
 435     }
 436     set_constants(NULL);
 437   }
 438 
 439   if (inner_classes() != NULL &&
 440       inner_classes() != Universe::the_empty_short_array() &&
 441       !inner_classes()->is_shared()) {
 442     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 443   }
 444   set_inner_classes(NULL);
 445 
 446   // We should deallocate the Annotations instance if it's not in shared spaces.
 447   if (annotations() != NULL && !annotations()->is_shared()) {
 448     MetadataFactory::free_metadata(loader_data, annotations());
 449   }
 450   set_annotations(NULL);
 451 }
 452 
 453 bool InstanceKlass::should_be_initialized() const {
 454   return !is_initialized();
 455 }
 456 
 457 klassVtable* InstanceKlass::vtable() const {
 458   return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
 459 }
 460 
 461 klassItable* InstanceKlass::itable() const {
 462   return new klassItable(instanceKlassHandle(this));
 463 }
 464 
 465 void InstanceKlass::eager_initialize(Thread *thread) {
 466   if (!EagerInitialization) return;
 467 
 468   if (this->is_not_initialized()) {
 469     // abort if the the class has a class initializer
 470     if (this->class_initializer() != NULL) return;
 471 
 472     // abort if it is java.lang.Object (initialization is handled in genesis)
 473     Klass* super = this->super();
 474     if (super == NULL) return;
 475 
 476     // abort if the super class should be initialized
 477     if (!InstanceKlass::cast(super)->is_initialized()) return;
 478 
 479     // call body to expose the this pointer
 480     instanceKlassHandle this_oop(thread, this);
 481     eager_initialize_impl(this_oop);
 482   }
 483 }
 484 
 485 // JVMTI spec thinks there are signers and protection domain in the
 486 // instanceKlass.  These accessors pretend these fields are there.
 487 // The hprof specification also thinks these fields are in InstanceKlass.
 488 oop InstanceKlass::protection_domain() const {
 489   // return the protection_domain from the mirror
 490   return java_lang_Class::protection_domain(java_mirror());
 491 }
 492 
 493 // To remove these from requires an incompatible change and CCC request.
 494 objArrayOop InstanceKlass::signers() const {
 495   // return the signers from the mirror
 496   return java_lang_Class::signers(java_mirror());
 497 }
 498 
 499 oop InstanceKlass::init_lock() const {
 500   // return the init lock from the mirror
 501   oop lock = java_lang_Class::init_lock(java_mirror());
 502   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
 503          "only fully initialized state can have a null lock");
 504   return lock;
 505 }
 506 
 507 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 508 // threads to get this lock will see a null lock and will not lock.
 509 // That's okay because they all check for initialized state after getting
 510 // the lock and return.
 511 void InstanceKlass::fence_and_clear_init_lock() {
 512   // make sure previous stores are all done, notably the init_state.
 513   OrderAccess::storestore();
 514   java_lang_Class::set_init_lock(java_mirror(), NULL);
 515   assert(!is_not_initialized(), "class must be initialized now");
 516 }
 517 
 518 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
 519   EXCEPTION_MARK;
 520   oop init_lock = this_oop->init_lock();
 521   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 522 
 523   // abort if someone beat us to the initialization
 524   if (!this_oop->is_not_initialized()) return;  // note: not equivalent to is_initialized()
 525 
 526   ClassState old_state = this_oop->init_state();
 527   link_class_impl(this_oop, true, THREAD);
 528   if (HAS_PENDING_EXCEPTION) {
 529     CLEAR_PENDING_EXCEPTION;
 530     // Abort if linking the class throws an exception.
 531 
 532     // Use a test to avoid redundantly resetting the state if there's
 533     // no change.  Set_init_state() asserts that state changes make
 534     // progress, whereas here we might just be spinning in place.
 535     if( old_state != this_oop->_init_state )
 536       this_oop->set_init_state (old_state);
 537   } else {
 538     // linking successfull, mark class as initialized
 539     this_oop->set_init_state (fully_initialized);
 540     this_oop->fence_and_clear_init_lock();
 541     // trace
 542     if (TraceClassInitialization) {
 543       ResourceMark rm(THREAD);
 544       tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
 545     }
 546   }
 547 }
 548 
 549 
 550 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 551 // process. The step comments refers to the procedure described in that section.
 552 // Note: implementation moved to static method to expose the this pointer.
 553 void InstanceKlass::initialize(TRAPS) {
 554   if (this->should_be_initialized()) {
 555     HandleMark hm(THREAD);
 556     instanceKlassHandle this_oop(THREAD, this);
 557     initialize_impl(this_oop, CHECK);
 558     // Note: at this point the class may be initialized
 559     //       OR it may be in the state of being initialized
 560     //       in case of recursive initialization!
 561   } else {
 562     assert(is_initialized(), "sanity check");
 563   }
 564 }
 565 
 566 
 567 bool InstanceKlass::verify_code(
 568     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
 569   // 1) Verify the bytecodes
 570   Verifier::Mode mode =
 571     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
 572   return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
 573 }
 574 
 575 
 576 // Used exclusively by the shared spaces dump mechanism to prevent
 577 // classes mapped into the shared regions in new VMs from appearing linked.
 578 
 579 void InstanceKlass::unlink_class() {
 580   assert(is_linked(), "must be linked");
 581   _init_state = loaded;
 582 }
 583 
 584 void InstanceKlass::link_class(TRAPS) {
 585   assert(is_loaded(), "must be loaded");
 586   if (!is_linked()) {
 587     HandleMark hm(THREAD);
 588     instanceKlassHandle this_oop(THREAD, this);
 589     link_class_impl(this_oop, true, CHECK);
 590   }
 591 }
 592 
 593 // Called to verify that a class can link during initialization, without
 594 // throwing a VerifyError.
 595 bool InstanceKlass::link_class_or_fail(TRAPS) {
 596   assert(is_loaded(), "must be loaded");
 597   if (!is_linked()) {
 598     HandleMark hm(THREAD);
 599     instanceKlassHandle this_oop(THREAD, this);
 600     link_class_impl(this_oop, false, CHECK_false);
 601   }
 602   return is_linked();
 603 }
 604 
 605 bool InstanceKlass::link_class_impl(
 606     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
 607   // check for error state
 608   if (this_oop->is_in_error_state()) {
 609     ResourceMark rm(THREAD);
 610     THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
 611                this_oop->external_name(), false);
 612   }
 613   // return if already verified
 614   if (this_oop->is_linked()) {
 615     return true;
 616   }
 617 
 618   // Timing
 619   // timer handles recursion
 620   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 621   JavaThread* jt = (JavaThread*)THREAD;
 622 
 623   // link super class before linking this class
 624   instanceKlassHandle super(THREAD, this_oop->super());
 625   if (super.not_null()) {
 626     if (super->is_interface()) {  // check if super class is an interface
 627       ResourceMark rm(THREAD);
 628       Exceptions::fthrow(
 629         THREAD_AND_LOCATION,
 630         vmSymbols::java_lang_IncompatibleClassChangeError(),
 631         "class %s has interface %s as super class",
 632         this_oop->external_name(),
 633         super->external_name()
 634       );
 635       return false;
 636     }
 637 
 638     link_class_impl(super, throw_verifyerror, CHECK_false);
 639   }
 640 
 641   // link all interfaces implemented by this class before linking this class
 642   Array<Klass*>* interfaces = this_oop->local_interfaces();
 643   int num_interfaces = interfaces->length();
 644   for (int index = 0; index < num_interfaces; index++) {
 645     HandleMark hm(THREAD);
 646     instanceKlassHandle ih(THREAD, interfaces->at(index));
 647     link_class_impl(ih, throw_verifyerror, CHECK_false);
 648   }
 649 
 650   // in case the class is linked in the process of linking its superclasses
 651   if (this_oop->is_linked()) {
 652     return true;
 653   }
 654 
 655   // trace only the link time for this klass that includes
 656   // the verification time
 657   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 658                              ClassLoader::perf_class_link_selftime(),
 659                              ClassLoader::perf_classes_linked(),
 660                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 661                              jt->get_thread_stat()->perf_timers_addr(),
 662                              PerfClassTraceTime::CLASS_LINK);
 663 
 664   // verification & rewriting
 665   {
 666     oop init_lock = this_oop->init_lock();
 667     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 668     // rewritten will have been set if loader constraint error found
 669     // on an earlier link attempt
 670     // don't verify or rewrite if already rewritten
 671 
 672     if (!this_oop->is_linked()) {
 673       if (!this_oop->is_rewritten()) {
 674         {
 675           // Timer includes any side effects of class verification (resolution,
 676           // etc), but not recursive entry into verify_code().
 677           PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
 678                                    ClassLoader::perf_class_verify_selftime(),
 679                                    ClassLoader::perf_classes_verified(),
 680                                    jt->get_thread_stat()->perf_recursion_counts_addr(),
 681                                    jt->get_thread_stat()->perf_timers_addr(),
 682                                    PerfClassTraceTime::CLASS_VERIFY);
 683           bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
 684           if (!verify_ok) {
 685             return false;
 686           }
 687         }
 688 
 689         // Just in case a side-effect of verify linked this class already
 690         // (which can sometimes happen since the verifier loads classes
 691         // using custom class loaders, which are free to initialize things)
 692         if (this_oop->is_linked()) {
 693           return true;
 694         }
 695 
 696         // also sets rewritten
 697         this_oop->rewrite_class(CHECK_false);
 698       }
 699 
 700       // relocate jsrs and link methods after they are all rewritten
 701       this_oop->link_methods(CHECK_false);
 702 
 703       // Initialize the vtable and interface table after
 704       // methods have been rewritten since rewrite may
 705       // fabricate new Method*s.
 706       // also does loader constraint checking
 707       if (!this_oop()->is_shared()) {
 708         ResourceMark rm(THREAD);
 709         this_oop->vtable()->initialize_vtable(true, CHECK_false);
 710         this_oop->itable()->initialize_itable(true, CHECK_false);
 711       }
 712 #ifdef ASSERT
 713       else {
 714         ResourceMark rm(THREAD);
 715         this_oop->vtable()->verify(tty, true);
 716         // In case itable verification is ever added.
 717         // this_oop->itable()->verify(tty, true);
 718       }
 719 #endif
 720       this_oop->set_init_state(linked);
 721       if (JvmtiExport::should_post_class_prepare()) {
 722         Thread *thread = THREAD;
 723         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 724         JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
 725       }
 726     }
 727   }
 728   return true;
 729 }
 730 
 731 
 732 // Rewrite the byte codes of all of the methods of a class.
 733 // The rewriter must be called exactly once. Rewriting must happen after
 734 // verification but before the first method of the class is executed.
 735 void InstanceKlass::rewrite_class(TRAPS) {
 736   assert(is_loaded(), "must be loaded");
 737   instanceKlassHandle this_oop(THREAD, this);
 738   if (this_oop->is_rewritten()) {
 739     assert(this_oop()->is_shared(), "rewriting an unshared class?");
 740     return;
 741   }
 742   Rewriter::rewrite(this_oop, CHECK);
 743   this_oop->set_rewritten();
 744 }
 745 
 746 // Now relocate and link method entry points after class is rewritten.
 747 // This is outside is_rewritten flag. In case of an exception, it can be
 748 // executed more than once.
 749 void InstanceKlass::link_methods(TRAPS) {
 750   int len = methods()->length();
 751   for (int i = len-1; i >= 0; i--) {
 752     methodHandle m(THREAD, methods()->at(i));
 753 
 754     // Set up method entry points for compiler and interpreter    .
 755     m->link_method(m, CHECK);
 756 
 757     // This is for JVMTI and unrelated to relocator but the last thing we do
 758 #ifdef ASSERT
 759     if (StressMethodComparator) {
 760       ResourceMark rm(THREAD);
 761       static int nmc = 0;
 762       for (int j = i; j >= 0 && j >= i-4; j--) {
 763         if ((++nmc % 1000) == 0)  tty->print_cr("Have run MethodComparator %d times...", nmc);
 764         bool z = MethodComparator::methods_EMCP(m(),
 765                    methods()->at(j));
 766         if (j == i && !z) {
 767           tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
 768           assert(z, "method must compare equal to itself");
 769         }
 770       }
 771     }
 772 #endif //ASSERT
 773   }
 774 }
 775 
 776 
 777 void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
 778   // Make sure klass is linked (verified) before initialization
 779   // A class could already be verified, since it has been reflected upon.
 780   this_oop->link_class(CHECK);
 781 
 782   DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
 783 
 784   bool wait = false;
 785 
 786   // refer to the JVM book page 47 for description of steps
 787   // Step 1
 788   {
 789     oop init_lock = this_oop->init_lock();
 790     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 791 
 792     Thread *self = THREAD; // it's passed the current thread
 793 
 794     // Step 2
 795     // If we were to use wait() instead of waitInterruptibly() then
 796     // we might end up throwing IE from link/symbol resolution sites
 797     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
 798     while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
 799         wait = true;
 800       ol.waitUninterruptibly(CHECK);
 801     }
 802 
 803     // Step 3
 804     if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
 805       DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
 806       return;
 807     }
 808 
 809     // Step 4
 810     if (this_oop->is_initialized()) {
 811       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
 812       return;
 813     }
 814 
 815     // Step 5
 816     if (this_oop->is_in_error_state()) {
 817       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
 818       ResourceMark rm(THREAD);
 819       const char* desc = "Could not initialize class ";
 820       const char* className = this_oop->external_name();
 821       size_t msglen = strlen(desc) + strlen(className) + 1;
 822       char* message = NEW_RESOURCE_ARRAY(char, msglen);
 823       if (NULL == message) {
 824         // Out of memory: can't create detailed error message
 825         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
 826       } else {
 827         jio_snprintf(message, msglen, "%s%s", desc, className);
 828         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
 829       }
 830     }
 831 
 832     // Step 6
 833     this_oop->set_init_state(being_initialized);
 834     this_oop->set_init_thread(self);
 835   }
 836 
 837   // Step 7
 838   Klass* super_klass = this_oop->super();
 839   if (super_klass != NULL && !this_oop->is_interface() && super_klass->should_be_initialized()) {
 840     super_klass->initialize(THREAD);
 841 
 842     if (HAS_PENDING_EXCEPTION) {
 843       Handle e(THREAD, PENDING_EXCEPTION);
 844       CLEAR_PENDING_EXCEPTION;
 845       {
 846         EXCEPTION_MARK;
 847         this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
 848         CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, superclass initialization error is thrown below
 849       }
 850       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
 851       THROW_OOP(e());
 852     }
 853   }
 854 
 855   if (this_oop->has_default_methods()) {
 856     // Step 7.5: initialize any interfaces which have default methods
 857     for (int i = 0; i < this_oop->local_interfaces()->length(); ++i) {
 858       Klass* iface = this_oop->local_interfaces()->at(i);
 859       InstanceKlass* ik = InstanceKlass::cast(iface);
 860       if (ik->has_default_methods() && ik->should_be_initialized()) {
 861         ik->initialize(THREAD);
 862 
 863         if (HAS_PENDING_EXCEPTION) {
 864           Handle e(THREAD, PENDING_EXCEPTION);
 865           CLEAR_PENDING_EXCEPTION;
 866           {
 867             EXCEPTION_MARK;
 868             // Locks object, set state, and notify all waiting threads
 869             this_oop->set_initialization_state_and_notify(
 870                 initialization_error, THREAD);
 871 
 872             // ignore any exception thrown, superclass initialization error is
 873             // thrown below
 874             CLEAR_PENDING_EXCEPTION;
 875           }
 876           DTRACE_CLASSINIT_PROBE_WAIT(
 877               super__failed, InstanceKlass::cast(this_oop()), -1, wait);
 878           THROW_OOP(e());
 879         }
 880       }
 881     }
 882   }
 883 
 884   // Step 8
 885   {
 886     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
 887     JavaThread* jt = (JavaThread*)THREAD;
 888     DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
 889     // Timer includes any side effects of class initialization (resolution,
 890     // etc), but not recursive entry into call_class_initializer().
 891     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
 892                              ClassLoader::perf_class_init_selftime(),
 893                              ClassLoader::perf_classes_inited(),
 894                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 895                              jt->get_thread_stat()->perf_timers_addr(),
 896                              PerfClassTraceTime::CLASS_CLINIT);
 897     this_oop->call_class_initializer(THREAD);
 898   }
 899 
 900   // Step 9
 901   if (!HAS_PENDING_EXCEPTION) {
 902     this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
 903     { ResourceMark rm(THREAD);
 904       debug_only(this_oop->vtable()->verify(tty, true);)
 905     }
 906   }
 907   else {
 908     // Step 10 and 11
 909     Handle e(THREAD, PENDING_EXCEPTION);
 910     CLEAR_PENDING_EXCEPTION;
 911     {
 912       EXCEPTION_MARK;
 913       this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
 914       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
 915     }
 916     DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
 917     if (e->is_a(SystemDictionary::Error_klass())) {
 918       THROW_OOP(e());
 919     } else {
 920       JavaCallArguments args(e);
 921       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
 922                 vmSymbols::throwable_void_signature(),
 923                 &args);
 924     }
 925   }
 926   DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
 927 }
 928 
 929 
 930 // Note: implementation moved to static method to expose the this pointer.
 931 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
 932   instanceKlassHandle kh(THREAD, this);
 933   set_initialization_state_and_notify_impl(kh, state, CHECK);
 934 }
 935 
 936 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
 937   oop init_lock = this_oop->init_lock();
 938   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 939   this_oop->set_init_state(state);
 940   this_oop->fence_and_clear_init_lock();
 941   ol.notify_all(CHECK);
 942 }
 943 
 944 // The embedded _implementor field can only record one implementor.
 945 // When there are more than one implementors, the _implementor field
 946 // is set to the interface Klass* itself. Following are the possible
 947 // values for the _implementor field:
 948 //   NULL                  - no implementor
 949 //   implementor Klass*    - one implementor
 950 //   self                  - more than one implementor
 951 //
 952 // The _implementor field only exists for interfaces.
 953 void InstanceKlass::add_implementor(Klass* k) {
 954   assert(Compile_lock->owned_by_self(), "");
 955   assert(is_interface(), "not interface");
 956   // Filter out my subinterfaces.
 957   // (Note: Interfaces are never on the subklass list.)
 958   if (InstanceKlass::cast(k)->is_interface()) return;
 959 
 960   // Filter out subclasses whose supers already implement me.
 961   // (Note: CHA must walk subclasses of direct implementors
 962   // in order to locate indirect implementors.)
 963   Klass* sk = InstanceKlass::cast(k)->super();
 964   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
 965     // We only need to check one immediate superclass, since the
 966     // implements_interface query looks at transitive_interfaces.
 967     // Any supers of the super have the same (or fewer) transitive_interfaces.
 968     return;
 969 
 970   Klass* ik = implementor();
 971   if (ik == NULL) {
 972     set_implementor(k);
 973   } else if (ik != this) {
 974     // There is already an implementor. Use itself as an indicator of
 975     // more than one implementors.
 976     set_implementor(this);
 977   }
 978 
 979   // The implementor also implements the transitive_interfaces
 980   for (int index = 0; index < local_interfaces()->length(); index++) {
 981     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
 982   }
 983 }
 984 
 985 void InstanceKlass::init_implementor() {
 986   if (is_interface()) {
 987     set_implementor(NULL);
 988   }
 989 }
 990 
 991 
 992 void InstanceKlass::process_interfaces(Thread *thread) {
 993   // link this class into the implementors list of every interface it implements
 994   Klass* this_as_klass_oop = this;
 995   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
 996     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
 997     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
 998     assert(interf->is_interface(), "expected interface");
 999     interf->add_implementor(this_as_klass_oop);
1000   }
1001 }
1002 
1003 bool InstanceKlass::can_be_primary_super_slow() const {
1004   if (is_interface())
1005     return false;
1006   else
1007     return Klass::can_be_primary_super_slow();
1008 }
1009 
1010 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
1011   // The secondaries are the implemented interfaces.
1012   InstanceKlass* ik = InstanceKlass::cast(this);
1013   Array<Klass*>* interfaces = ik->transitive_interfaces();
1014   int num_secondaries = num_extra_slots + interfaces->length();
1015   if (num_secondaries == 0) {
1016     // Must share this for correct bootstrapping!
1017     set_secondary_supers(Universe::the_empty_klass_array());
1018     return NULL;
1019   } else if (num_extra_slots == 0) {
1020     // The secondary super list is exactly the same as the transitive interfaces.
1021     // Redefine classes has to be careful not to delete this!
1022     set_secondary_supers(interfaces);
1023     return NULL;
1024   } else {
1025     // Copy transitive interfaces to a temporary growable array to be constructed
1026     // into the secondary super list with extra slots.
1027     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1028     for (int i = 0; i < interfaces->length(); i++) {
1029       secondaries->push(interfaces->at(i));
1030     }
1031     return secondaries;
1032   }
1033 }
1034 
1035 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
1036   if (k->is_interface()) {
1037     return implements_interface(k);
1038   } else {
1039     return Klass::compute_is_subtype_of(k);
1040   }
1041 }
1042 
1043 bool InstanceKlass::implements_interface(Klass* k) const {
1044   if (this == k) return true;
1045   assert(k->is_interface(), "should be an interface class");
1046   for (int i = 0; i < transitive_interfaces()->length(); i++) {
1047     if (transitive_interfaces()->at(i) == k) {
1048       return true;
1049     }
1050   }
1051   return false;
1052 }
1053 
1054 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1055   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
1056   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
1057     report_java_out_of_memory("Requested array size exceeds VM limit");
1058     JvmtiExport::post_array_size_exhausted();
1059     THROW_OOP_0(Universe::out_of_memory_error_array_size());
1060   }
1061   int size = objArrayOopDesc::object_size(length);
1062   Klass* ak = array_klass(n, CHECK_NULL);
1063   KlassHandle h_ak (THREAD, ak);
1064   objArrayOop o =
1065     (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
1066   return o;
1067 }
1068 
1069 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1070   if (TraceFinalizerRegistration) {
1071     tty->print("Registered ");
1072     i->print_value_on(tty);
1073     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
1074   }
1075   instanceHandle h_i(THREAD, i);
1076   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1077   JavaValue result(T_VOID);
1078   JavaCallArguments args(h_i);
1079   methodHandle mh (THREAD, Universe::finalizer_register_method());
1080   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1081   return h_i();
1082 }
1083 
1084 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1085   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1086   int size = size_helper();  // Query before forming handle.
1087 
1088   KlassHandle h_k(THREAD, this);
1089 
1090   instanceOop i;
1091 
1092   i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
1093   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1094     i = register_finalizer(i, CHECK_NULL);
1095   }
1096   return i;
1097 }
1098 
1099 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1100   if (is_interface() || is_abstract()) {
1101     ResourceMark rm(THREAD);
1102     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1103               : vmSymbols::java_lang_InstantiationException(), external_name());
1104   }
1105   if (this == SystemDictionary::Class_klass()) {
1106     ResourceMark rm(THREAD);
1107     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1108               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1109   }
1110 }
1111 
1112 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1113   instanceKlassHandle this_oop(THREAD, this);
1114   return array_klass_impl(this_oop, or_null, n, THREAD);
1115 }
1116 
1117 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
1118   if (this_oop->array_klasses() == NULL) {
1119     if (or_null) return NULL;
1120 
1121     ResourceMark rm;
1122     JavaThread *jt = (JavaThread *)THREAD;
1123     {
1124       // Atomic creation of array_klasses
1125       MutexLocker mc(Compile_lock, THREAD);   // for vtables
1126       MutexLocker ma(MultiArray_lock, THREAD);
1127 
1128       // Check if update has already taken place
1129       if (this_oop->array_klasses() == NULL) {
1130         Klass*    k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
1131         this_oop->set_array_klasses(k);
1132       }
1133     }
1134   }
1135   // _this will always be set at this point
1136   ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
1137   if (or_null) {
1138     return oak->array_klass_or_null(n);
1139   }
1140   return oak->array_klass(n, CHECK_NULL);
1141 }
1142 
1143 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1144   return array_klass_impl(or_null, 1, THREAD);
1145 }
1146 
1147 void InstanceKlass::call_class_initializer(TRAPS) {
1148   instanceKlassHandle ik (THREAD, this);
1149   call_class_initializer_impl(ik, THREAD);
1150 }
1151 
1152 static int call_class_initializer_impl_counter = 0;   // for debugging
1153 
1154 Method* InstanceKlass::class_initializer() {
1155   Method* clinit = find_method(
1156       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1157   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1158     return clinit;
1159   }
1160   return NULL;
1161 }
1162 
1163 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
1164   if (ReplayCompiles &&
1165       (ReplaySuppressInitializers == 1 ||
1166        ReplaySuppressInitializers >= 2 && this_oop->class_loader() != NULL)) {
1167     // Hide the existence of the initializer for the purpose of replaying the compile
1168     return;
1169   }
1170 
1171   methodHandle h_method(THREAD, this_oop->class_initializer());
1172   assert(!this_oop->is_initialized(), "we cannot initialize twice");
1173   if (TraceClassInitialization) {
1174     tty->print("%d Initializing ", call_class_initializer_impl_counter++);
1175     this_oop->name()->print_value();
1176     tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
1177   }
1178   if (h_method() != NULL) {
1179     JavaCallArguments args; // No arguments
1180     JavaValue result(T_VOID);
1181     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1182   }
1183 }
1184 
1185 
1186 void InstanceKlass::mask_for(methodHandle method, int bci,
1187   InterpreterOopMap* entry_for) {
1188   // Dirty read, then double-check under a lock.
1189   if (_oop_map_cache == NULL) {
1190     // Otherwise, allocate a new one.
1191     MutexLocker x(OopMapCacheAlloc_lock);
1192     // First time use. Allocate a cache in C heap
1193     if (_oop_map_cache == NULL) {
1194       _oop_map_cache = new OopMapCache();
1195     }
1196   }
1197   // _oop_map_cache is constant after init; lookup below does is own locking.
1198   _oop_map_cache->lookup(method, bci, entry_for);
1199 }
1200 
1201 
1202 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1203   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1204     Symbol* f_name = fs.name();
1205     Symbol* f_sig  = fs.signature();
1206     if (f_name == name && f_sig == sig) {
1207       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1208       return true;
1209     }
1210   }
1211   return false;
1212 }
1213 
1214 
1215 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1216   const int n = local_interfaces()->length();
1217   for (int i = 0; i < n; i++) {
1218     Klass* intf1 = local_interfaces()->at(i);
1219     assert(intf1->is_interface(), "just checking type");
1220     // search for field in current interface
1221     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1222       assert(fd->is_static(), "interface field must be static");
1223       return intf1;
1224     }
1225     // search for field in direct superinterfaces
1226     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1227     if (intf2 != NULL) return intf2;
1228   }
1229   // otherwise field lookup fails
1230   return NULL;
1231 }
1232 
1233 
1234 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1235   // search order according to newest JVM spec (5.4.3.2, p.167).
1236   // 1) search for field in current klass
1237   if (find_local_field(name, sig, fd)) {
1238     return const_cast<InstanceKlass*>(this);
1239   }
1240   // 2) search for field recursively in direct superinterfaces
1241   { Klass* intf = find_interface_field(name, sig, fd);
1242     if (intf != NULL) return intf;
1243   }
1244   // 3) apply field lookup recursively if superclass exists
1245   { Klass* supr = super();
1246     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1247   }
1248   // 4) otherwise field lookup fails
1249   return NULL;
1250 }
1251 
1252 
1253 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1254   // search order according to newest JVM spec (5.4.3.2, p.167).
1255   // 1) search for field in current klass
1256   if (find_local_field(name, sig, fd)) {
1257     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1258   }
1259   // 2) search for field recursively in direct superinterfaces
1260   if (is_static) {
1261     Klass* intf = find_interface_field(name, sig, fd);
1262     if (intf != NULL) return intf;
1263   }
1264   // 3) apply field lookup recursively if superclass exists
1265   { Klass* supr = super();
1266     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1267   }
1268   // 4) otherwise field lookup fails
1269   return NULL;
1270 }
1271 
1272 
1273 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1274   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1275     if (fs.offset() == offset) {
1276       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1277       if (fd->is_static() == is_static) return true;
1278     }
1279   }
1280   return false;
1281 }
1282 
1283 
1284 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1285   Klass* klass = const_cast<InstanceKlass*>(this);
1286   while (klass != NULL) {
1287     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1288       return true;
1289     }
1290     klass = klass->super();
1291   }
1292   return false;
1293 }
1294 
1295 
1296 void InstanceKlass::methods_do(void f(Method* method)) {
1297   int len = methods()->length();
1298   for (int index = 0; index < len; index++) {
1299     Method* m = methods()->at(index);
1300     assert(m->is_method(), "must be method");
1301     f(m);
1302   }
1303 }
1304 
1305 
1306 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1307   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1308     if (fs.access_flags().is_static()) {
1309       fieldDescriptor& fd = fs.field_descriptor();
1310       cl->do_field(&fd);
1311     }
1312   }
1313 }
1314 
1315 
1316 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
1317   instanceKlassHandle h_this(THREAD, this);
1318   do_local_static_fields_impl(h_this, f, CHECK);
1319 }
1320 
1321 
1322 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
1323   for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
1324     if (fs.access_flags().is_static()) {
1325       fieldDescriptor& fd = fs.field_descriptor();
1326       f(&fd, CHECK);
1327     }
1328   }
1329 }
1330 
1331 
1332 static int compare_fields_by_offset(int* a, int* b) {
1333   return a[0] - b[0];
1334 }
1335 
1336 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1337   InstanceKlass* super = superklass();
1338   if (super != NULL) {
1339     super->do_nonstatic_fields(cl);
1340   }
1341   fieldDescriptor fd;
1342   int length = java_fields_count();
1343   // In DebugInfo nonstatic fields are sorted by offset.
1344   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1345   int j = 0;
1346   for (int i = 0; i < length; i += 1) {
1347     fd.reinitialize(this, i);
1348     if (!fd.is_static()) {
1349       fields_sorted[j + 0] = fd.offset();
1350       fields_sorted[j + 1] = i;
1351       j += 2;
1352     }
1353   }
1354   if (j > 0) {
1355     length = j;
1356     // _sort_Fn is defined in growableArray.hpp.
1357     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1358     for (int i = 0; i < length; i += 2) {
1359       fd.reinitialize(this, fields_sorted[i + 1]);
1360       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1361       cl->do_field(&fd);
1362     }
1363   }
1364   FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
1365 }
1366 
1367 
1368 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1369   if (array_klasses() != NULL)
1370     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1371 }
1372 
1373 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1374   if (array_klasses() != NULL)
1375     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1376 }
1377 
1378 #ifdef ASSERT
1379 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
1380   int len = methods->length();
1381   for (int index = 0; index < len; index++) {
1382     Method* m = methods->at(index);
1383     assert(m->is_method(), "must be method");
1384     if (m->signature() == signature && m->name() == name) {
1385        return index;
1386     }
1387   }
1388   return -1;
1389 }
1390 #endif
1391 
1392 static int binary_search(Array<Method*>* methods, Symbol* name) {
1393   int len = methods->length();
1394   // methods are sorted, so do binary search
1395   int l = 0;
1396   int h = len - 1;
1397   while (l <= h) {
1398     int mid = (l + h) >> 1;
1399     Method* m = methods->at(mid);
1400     assert(m->is_method(), "must be method");
1401     int res = m->name()->fast_compare(name);
1402     if (res == 0) {
1403       return mid;
1404     } else if (res < 0) {
1405       l = mid + 1;
1406     } else {
1407       h = mid - 1;
1408     }
1409   }
1410   return -1;
1411 }
1412 
1413 // find_method looks up the name/signature in the local methods array
1414 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
1415   return InstanceKlass::find_method(methods(), name, signature);
1416 }
1417 
1418 // find_method looks up the name/signature in the local methods array
1419 Method* InstanceKlass::find_method(
1420     Array<Method*>* methods, Symbol* name, Symbol* signature) {
1421   int hit = find_method_index(methods, name, signature);
1422   return hit >= 0 ? methods->at(hit): NULL;
1423 }
1424 
1425 // Used directly for default_methods to find the index into the
1426 // default_vtable_indices, and indirectly by find_method
1427 // find_method_index looks in the local methods array to return the index
1428 // of the matching name/signature
1429 int InstanceKlass::find_method_index(
1430     Array<Method*>* methods, Symbol* name, Symbol* signature) {
1431   int hit = binary_search(methods, name);
1432   if (hit != -1) {
1433     Method* m = methods->at(hit);
1434     // Do linear search to find matching signature.  First, quick check
1435     // for common case
1436     if (m->signature() == signature) return hit;
1437     // search downwards through overloaded methods
1438     int i;
1439     for (i = hit - 1; i >= 0; --i) {
1440         Method* m = methods->at(i);
1441         assert(m->is_method(), "must be method");
1442         if (m->name() != name) break;
1443         if (m->signature() == signature) return i;
1444     }
1445     // search upwards
1446     for (i = hit + 1; i < methods->length(); ++i) {
1447         Method* m = methods->at(i);
1448         assert(m->is_method(), "must be method");
1449         if (m->name() != name) break;
1450         if (m->signature() == signature) return i;
1451     }
1452     // not found
1453 #ifdef ASSERT
1454     int index = linear_search(methods, name, signature);
1455     assert(index == -1, err_msg("binary search should have found entry %d", index));
1456 #endif
1457   }
1458   return -1;
1459 }
1460 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
1461   return find_method_by_name(methods(), name, end);
1462 }
1463 
1464 int InstanceKlass::find_method_by_name(
1465     Array<Method*>* methods, Symbol* name, int* end_ptr) {
1466   assert(end_ptr != NULL, "just checking");
1467   int start = binary_search(methods, name);
1468   int end = start + 1;
1469   if (start != -1) {
1470     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1471     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1472     *end_ptr = end;
1473     return start;
1474   }
1475   return -1;
1476 }
1477 
1478 // lookup_method searches both the local methods array and all superclasses methods arrays
1479 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
1480   Klass* klass = const_cast<InstanceKlass*>(this);
1481   while (klass != NULL) {
1482     Method* method = InstanceKlass::cast(klass)->find_method(name, signature);
1483     if (method != NULL) return method;
1484     klass = InstanceKlass::cast(klass)->super();
1485   }
1486   return NULL;
1487 }
1488 
1489 // lookup a method in the default methods list then in all transitive interfaces
1490 // Do NOT return private or static methods
1491 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1492                                                          Symbol* signature) const {
1493   Method* m = NULL;
1494   if (default_methods() != NULL) {
1495     m = find_method(default_methods(), name, signature);
1496   }
1497   // Look up interfaces
1498   if (m == NULL) {
1499     m = lookup_method_in_all_interfaces(name, signature);
1500   }
1501   return m;
1502 }
1503 
1504 // lookup a method in all the interfaces that this class implements
1505 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1506 // They should only be found in the initial InterfaceMethodRef
1507 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1508                                                          Symbol* signature) const {
1509   Array<Klass*>* all_ifs = transitive_interfaces();
1510   int num_ifs = all_ifs->length();
1511   InstanceKlass *ik = NULL;
1512   for (int i = 0; i < num_ifs; i++) {
1513     ik = InstanceKlass::cast(all_ifs->at(i));
1514     Method* m = ik->lookup_method(name, signature);
1515     if (m != NULL && m->is_public() && !m->is_static()) {
1516       return m;
1517     }
1518   }
1519   return NULL;
1520 }
1521 
1522 /* jni_id_for_impl for jfieldIds only */
1523 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
1524   MutexLocker ml(JfieldIdCreation_lock);
1525   // Retry lookup after we got the lock
1526   JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
1527   if (probe == NULL) {
1528     // Slow case, allocate new static field identifier
1529     probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
1530     this_oop->set_jni_ids(probe);
1531   }
1532   return probe;
1533 }
1534 
1535 
1536 /* jni_id_for for jfieldIds only */
1537 JNIid* InstanceKlass::jni_id_for(int offset) {
1538   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1539   if (probe == NULL) {
1540     probe = jni_id_for_impl(this, offset);
1541   }
1542   return probe;
1543 }
1544 
1545 u2 InstanceKlass::enclosing_method_data(int offset) {
1546   Array<jushort>* inner_class_list = inner_classes();
1547   if (inner_class_list == NULL) {
1548     return 0;
1549   }
1550   int length = inner_class_list->length();
1551   if (length % inner_class_next_offset == 0) {
1552     return 0;
1553   } else {
1554     int index = length - enclosing_method_attribute_size;
1555     assert(offset < enclosing_method_attribute_size, "invalid offset");
1556     return inner_class_list->at(index + offset);
1557   }
1558 }
1559 
1560 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1561                                                  u2 method_index) {
1562   Array<jushort>* inner_class_list = inner_classes();
1563   assert (inner_class_list != NULL, "_inner_classes list is not set up");
1564   int length = inner_class_list->length();
1565   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1566     int index = length - enclosing_method_attribute_size;
1567     inner_class_list->at_put(
1568       index + enclosing_method_class_index_offset, class_index);
1569     inner_class_list->at_put(
1570       index + enclosing_method_method_index_offset, method_index);
1571   }
1572 }
1573 
1574 // Lookup or create a jmethodID.
1575 // This code is called by the VMThread and JavaThreads so the
1576 // locking has to be done very carefully to avoid deadlocks
1577 // and/or other cache consistency problems.
1578 //
1579 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1580   size_t idnum = (size_t)method_h->method_idnum();
1581   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1582   size_t length = 0;
1583   jmethodID id = NULL;
1584 
1585   // We use a double-check locking idiom here because this cache is
1586   // performance sensitive. In the normal system, this cache only
1587   // transitions from NULL to non-NULL which is safe because we use
1588   // release_set_methods_jmethod_ids() to advertise the new cache.
1589   // A partially constructed cache should never be seen by a racing
1590   // thread. We also use release_store_ptr() to save a new jmethodID
1591   // in the cache so a partially constructed jmethodID should never be
1592   // seen either. Cache reads of existing jmethodIDs proceed without a
1593   // lock, but cache writes of a new jmethodID requires uniqueness and
1594   // creation of the cache itself requires no leaks so a lock is
1595   // generally acquired in those two cases.
1596   //
1597   // If the RedefineClasses() API has been used, then this cache can
1598   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1599   // Cache creation requires no leaks and we require safety between all
1600   // cache accesses and freeing of the old cache so a lock is generally
1601   // acquired when the RedefineClasses() API has been used.
1602 
1603   if (jmeths != NULL) {
1604     // the cache already exists
1605     if (!ik_h->idnum_can_increment()) {
1606       // the cache can't grow so we can just get the current values
1607       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1608     } else {
1609       // cache can grow so we have to be more careful
1610       if (Threads::number_of_threads() == 0 ||
1611           SafepointSynchronize::is_at_safepoint()) {
1612         // we're single threaded or at a safepoint - no locking needed
1613         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1614       } else {
1615         MutexLocker ml(JmethodIdCreation_lock);
1616         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1617       }
1618     }
1619   }
1620   // implied else:
1621   // we need to allocate a cache so default length and id values are good
1622 
1623   if (jmeths == NULL ||   // no cache yet
1624       length <= idnum ||  // cache is too short
1625       id == NULL) {       // cache doesn't contain entry
1626 
1627     // This function can be called by the VMThread so we have to do all
1628     // things that might block on a safepoint before grabbing the lock.
1629     // Otherwise, we can deadlock with the VMThread or have a cache
1630     // consistency issue. These vars keep track of what we might have
1631     // to free after the lock is dropped.
1632     jmethodID  to_dealloc_id     = NULL;
1633     jmethodID* to_dealloc_jmeths = NULL;
1634 
1635     // may not allocate new_jmeths or use it if we allocate it
1636     jmethodID* new_jmeths = NULL;
1637     if (length <= idnum) {
1638       // allocate a new cache that might be used
1639       size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1640       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1641       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1642       // cache size is stored in element[0], other elements offset by one
1643       new_jmeths[0] = (jmethodID)size;
1644     }
1645 
1646     // allocate a new jmethodID that might be used
1647     jmethodID new_id = NULL;
1648     if (method_h->is_old() && !method_h->is_obsolete()) {
1649       // The method passed in is old (but not obsolete), we need to use the current version
1650       Method* current_method = ik_h->method_with_idnum((int)idnum);
1651       assert(current_method != NULL, "old and but not obsolete, so should exist");
1652       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
1653     } else {
1654       // It is the current version of the method or an obsolete method,
1655       // use the version passed in
1656       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
1657     }
1658 
1659     if (Threads::number_of_threads() == 0 ||
1660         SafepointSynchronize::is_at_safepoint()) {
1661       // we're single threaded or at a safepoint - no locking needed
1662       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1663                                           &to_dealloc_id, &to_dealloc_jmeths);
1664     } else {
1665       MutexLocker ml(JmethodIdCreation_lock);
1666       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1667                                           &to_dealloc_id, &to_dealloc_jmeths);
1668     }
1669 
1670     // The lock has been dropped so we can free resources.
1671     // Free up either the old cache or the new cache if we allocated one.
1672     if (to_dealloc_jmeths != NULL) {
1673       FreeHeap(to_dealloc_jmeths);
1674     }
1675     // free up the new ID since it wasn't needed
1676     if (to_dealloc_id != NULL) {
1677       Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
1678     }
1679   }
1680   return id;
1681 }
1682 
1683 
1684 // Common code to fetch the jmethodID from the cache or update the
1685 // cache with the new jmethodID. This function should never do anything
1686 // that causes the caller to go to a safepoint or we can deadlock with
1687 // the VMThread or have cache consistency issues.
1688 //
1689 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1690             instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1691             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1692             jmethodID** to_dealloc_jmeths_p) {
1693   assert(new_id != NULL, "sanity check");
1694   assert(to_dealloc_id_p != NULL, "sanity check");
1695   assert(to_dealloc_jmeths_p != NULL, "sanity check");
1696   assert(Threads::number_of_threads() == 0 ||
1697          SafepointSynchronize::is_at_safepoint() ||
1698          JmethodIdCreation_lock->owned_by_self(), "sanity check");
1699 
1700   // reacquire the cache - we are locked, single threaded or at a safepoint
1701   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1702   jmethodID  id     = NULL;
1703   size_t     length = 0;
1704 
1705   if (jmeths == NULL ||                         // no cache yet
1706       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
1707     if (jmeths != NULL) {
1708       // copy any existing entries from the old cache
1709       for (size_t index = 0; index < length; index++) {
1710         new_jmeths[index+1] = jmeths[index+1];
1711       }
1712       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
1713     }
1714     ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1715   } else {
1716     // fetch jmethodID (if any) from the existing cache
1717     id = jmeths[idnum+1];
1718     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
1719   }
1720   if (id == NULL) {
1721     // No matching jmethodID in the existing cache or we have a new
1722     // cache or we just grew the cache. This cache write is done here
1723     // by the first thread to win the foot race because a jmethodID
1724     // needs to be unique once it is generally available.
1725     id = new_id;
1726 
1727     // The jmethodID cache can be read while unlocked so we have to
1728     // make sure the new jmethodID is complete before installing it
1729     // in the cache.
1730     OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1731   } else {
1732     *to_dealloc_id_p = new_id; // save new id for later delete
1733   }
1734   return id;
1735 }
1736 
1737 
1738 // Common code to get the jmethodID cache length and the jmethodID
1739 // value at index idnum if there is one.
1740 //
1741 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1742        size_t idnum, size_t *length_p, jmethodID* id_p) {
1743   assert(cache != NULL, "sanity check");
1744   assert(length_p != NULL, "sanity check");
1745   assert(id_p != NULL, "sanity check");
1746 
1747   // cache size is stored in element[0], other elements offset by one
1748   *length_p = (size_t)cache[0];
1749   if (*length_p <= idnum) {  // cache is too short
1750     *id_p = NULL;
1751   } else {
1752     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
1753   }
1754 }
1755 
1756 
1757 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
1758 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1759   size_t idnum = (size_t)method->method_idnum();
1760   jmethodID* jmeths = methods_jmethod_ids_acquire();
1761   size_t length;                                // length assigned as debugging crumb
1762   jmethodID id = NULL;
1763   if (jmeths != NULL &&                         // If there is a cache
1764       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
1765     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
1766   }
1767   return id;
1768 }
1769 
1770 
1771 //
1772 // Walk the list of dependent nmethods searching for nmethods which
1773 // are dependent on the changes that were passed in and mark them for
1774 // deoptimization.  Returns the number of nmethods found.
1775 //
1776 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
1777   assert_locked_or_safepoint(CodeCache_lock);
1778   int found = 0;
1779   nmethodBucket* b = _dependencies;
1780   while (b != NULL) {
1781     nmethod* nm = b->get_nmethod();
1782     // since dependencies aren't removed until an nmethod becomes a zombie,
1783     // the dependency list may contain nmethods which aren't alive.
1784     if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1785       if (TraceDependencies) {
1786         ResourceMark rm;
1787         tty->print_cr("Marked for deoptimization");
1788         tty->print_cr("  context = %s", this->external_name());
1789         changes.print();
1790         nm->print();
1791         nm->print_dependencies();
1792       }
1793       nm->mark_for_deoptimization();
1794       found++;
1795     }
1796     b = b->next();
1797   }
1798   return found;
1799 }
1800 
1801 
1802 //
1803 // Add an nmethodBucket to the list of dependencies for this nmethod.
1804 // It's possible that an nmethod has multiple dependencies on this klass
1805 // so a count is kept for each bucket to guarantee that creation and
1806 // deletion of dependencies is consistent.
1807 //
1808 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1809   assert_locked_or_safepoint(CodeCache_lock);
1810   nmethodBucket* b = _dependencies;
1811   nmethodBucket* last = NULL;
1812   while (b != NULL) {
1813     if (nm == b->get_nmethod()) {
1814       b->increment();
1815       return;
1816     }
1817     b = b->next();
1818   }
1819   _dependencies = new nmethodBucket(nm, _dependencies);
1820 }
1821 
1822 
1823 //
1824 // Decrement count of the nmethod in the dependency list and remove
1825 // the bucket competely when the count goes to 0.  This method must
1826 // find a corresponding bucket otherwise there's a bug in the
1827 // recording of dependecies.
1828 //
1829 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
1830   assert_locked_or_safepoint(CodeCache_lock);
1831   nmethodBucket* b = _dependencies;
1832   nmethodBucket* last = NULL;
1833   while (b != NULL) {
1834     if (nm == b->get_nmethod()) {
1835       if (b->decrement() == 0) {
1836         if (last == NULL) {
1837           _dependencies = b->next();
1838         } else {
1839           last->set_next(b->next());
1840         }
1841         delete b;
1842       }
1843       return;
1844     }
1845     last = b;
1846     b = b->next();
1847   }
1848 #ifdef ASSERT
1849   tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1850   nm->print();
1851 #endif // ASSERT
1852   ShouldNotReachHere();
1853 }
1854 
1855 
1856 #ifndef PRODUCT
1857 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1858   nmethodBucket* b = _dependencies;
1859   int idx = 0;
1860   while (b != NULL) {
1861     nmethod* nm = b->get_nmethod();
1862     tty->print("[%d] count=%d { ", idx++, b->count());
1863     if (!verbose) {
1864       nm->print_on(tty, "nmethod");
1865       tty->print_cr(" } ");
1866     } else {
1867       nm->print();
1868       nm->print_dependencies();
1869       tty->print_cr("--- } ");
1870     }
1871     b = b->next();
1872   }
1873 }
1874 
1875 
1876 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1877   nmethodBucket* b = _dependencies;
1878   while (b != NULL) {
1879     if (nm == b->get_nmethod()) {
1880       return true;
1881     }
1882     b = b->next();
1883   }
1884   return false;
1885 }
1886 #endif //PRODUCT
1887 
1888 
1889 // Garbage collection
1890 
1891 #ifdef ASSERT
1892 template <class T> void assert_is_in(T *p) {
1893   T heap_oop = oopDesc::load_heap_oop(p);
1894   if (!oopDesc::is_null(heap_oop)) {
1895     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1896     assert(Universe::heap()->is_in(o), "should be in heap");
1897   }
1898 }
1899 template <class T> void assert_is_in_closed_subset(T *p) {
1900   T heap_oop = oopDesc::load_heap_oop(p);
1901   if (!oopDesc::is_null(heap_oop)) {
1902     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1903     assert(Universe::heap()->is_in_closed_subset(o),
1904            err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
1905   }
1906 }
1907 template <class T> void assert_is_in_reserved(T *p) {
1908   T heap_oop = oopDesc::load_heap_oop(p);
1909   if (!oopDesc::is_null(heap_oop)) {
1910     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1911     assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
1912   }
1913 }
1914 template <class T> void assert_nothing(T *p) {}
1915 
1916 #else
1917 template <class T> void assert_is_in(T *p) {}
1918 template <class T> void assert_is_in_closed_subset(T *p) {}
1919 template <class T> void assert_is_in_reserved(T *p) {}
1920 template <class T> void assert_nothing(T *p) {}
1921 #endif // ASSERT
1922 
1923 //
1924 // Macros that iterate over areas of oops which are specialized on type of
1925 // oop pointer either narrow or wide, depending on UseCompressedOops
1926 //
1927 // Parameters are:
1928 //   T         - type of oop to point to (either oop or narrowOop)
1929 //   start_p   - starting pointer for region to iterate over
1930 //   count     - number of oops or narrowOops to iterate over
1931 //   do_oop    - action to perform on each oop (it's arbitrary C code which
1932 //               makes it more efficient to put in a macro rather than making
1933 //               it a template function)
1934 //   assert_fn - assert function which is template function because performance
1935 //               doesn't matter when enabled.
1936 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
1937   T, start_p, count, do_oop,                \
1938   assert_fn)                                \
1939 {                                           \
1940   T* p         = (T*)(start_p);             \
1941   T* const end = p + (count);               \
1942   while (p < end) {                         \
1943     (assert_fn)(p);                         \
1944     do_oop;                                 \
1945     ++p;                                    \
1946   }                                         \
1947 }
1948 
1949 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
1950   T, start_p, count, do_oop,                \
1951   assert_fn)                                \
1952 {                                           \
1953   T* const start = (T*)(start_p);           \
1954   T*       p     = start + (count);         \
1955   while (start < p) {                       \
1956     --p;                                    \
1957     (assert_fn)(p);                         \
1958     do_oop;                                 \
1959   }                                         \
1960 }
1961 
1962 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
1963   T, start_p, count, low, high,             \
1964   do_oop, assert_fn)                        \
1965 {                                           \
1966   T* const l = (T*)(low);                   \
1967   T* const h = (T*)(high);                  \
1968   assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
1969          mask_bits((intptr_t)h, sizeof(T)-1) == 0,   \
1970          "bounded region must be properly aligned"); \
1971   T* p       = (T*)(start_p);               \
1972   T* end     = p + (count);                 \
1973   if (p < l) p = l;                         \
1974   if (end > h) end = h;                     \
1975   while (p < end) {                         \
1976     (assert_fn)(p);                         \
1977     do_oop;                                 \
1978     ++p;                                    \
1979   }                                         \
1980 }
1981 
1982 
1983 // The following macros call specialized macros, passing either oop or
1984 // narrowOop as the specialization type.  These test the UseCompressedOops
1985 // flag.
1986 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn)            \
1987 {                                                                        \
1988   /* Compute oopmap block range. The common case                         \
1989      is nonstatic_oop_map_size == 1. */                                  \
1990   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
1991   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
1992   if (UseCompressedOops) {                                               \
1993     while (map < end_map) {                                              \
1994       InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop,                   \
1995         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
1996         do_oop, assert_fn)                                               \
1997       ++map;                                                             \
1998     }                                                                    \
1999   } else {                                                               \
2000     while (map < end_map) {                                              \
2001       InstanceKlass_SPECIALIZED_OOP_ITERATE(oop,                         \
2002         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
2003         do_oop, assert_fn)                                               \
2004       ++map;                                                             \
2005     }                                                                    \
2006   }                                                                      \
2007 }
2008 
2009 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn)    \
2010 {                                                                        \
2011   OopMapBlock* const start_map = start_of_nonstatic_oop_maps();          \
2012   OopMapBlock* map             = start_map + nonstatic_oop_map_count();  \
2013   if (UseCompressedOops) {                                               \
2014     while (start_map < map) {                                            \
2015       --map;                                                             \
2016       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop,           \
2017         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
2018         do_oop, assert_fn)                                               \
2019     }                                                                    \
2020   } else {                                                               \
2021     while (start_map < map) {                                            \
2022       --map;                                                             \
2023       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop,                 \
2024         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
2025         do_oop, assert_fn)                                               \
2026     }                                                                    \
2027   }                                                                      \
2028 }
2029 
2030 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop,    \
2031                                               assert_fn)                 \
2032 {                                                                        \
2033   /* Compute oopmap block range. The common case is                      \
2034      nonstatic_oop_map_size == 1, so we accept the                       \
2035      usually non-existent extra overhead of examining                    \
2036      all the maps. */                                                    \
2037   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
2038   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
2039   if (UseCompressedOops) {                                               \
2040     while (map < end_map) {                                              \
2041       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop,           \
2042         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
2043         low, high,                                                       \
2044         do_oop, assert_fn)                                               \
2045       ++map;                                                             \
2046     }                                                                    \
2047   } else {                                                               \
2048     while (map < end_map) {                                              \
2049       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop,                 \
2050         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
2051         low, high,                                                       \
2052         do_oop, assert_fn)                                               \
2053       ++map;                                                             \
2054     }                                                                    \
2055   }                                                                      \
2056 }
2057 
2058 void InstanceKlass::oop_follow_contents(oop obj) {
2059   assert(obj != NULL, "can't follow the content of NULL object");
2060   MarkSweep::follow_klass(obj->klass());
2061   InstanceKlass_OOP_MAP_ITERATE( \
2062     obj, \
2063     MarkSweep::mark_and_push(p), \
2064     assert_is_in_closed_subset)
2065 }
2066 
2067 #if INCLUDE_ALL_GCS
2068 void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
2069                                         oop obj) {
2070   assert(obj != NULL, "can't follow the content of NULL object");
2071   PSParallelCompact::follow_klass(cm, obj->klass());
2072   // Only mark the header and let the scan of the meta-data mark
2073   // everything else.
2074   InstanceKlass_OOP_MAP_ITERATE( \
2075     obj, \
2076     PSParallelCompact::mark_and_push(cm, p), \
2077     assert_is_in)
2078 }
2079 #endif // INCLUDE_ALL_GCS
2080 
2081 // closure's do_metadata() method dictates whether the given closure should be
2082 // applied to the klass ptr in the object header.
2083 
2084 #define if_do_metadata_checked(closure, nv_suffix)                    \
2085   /* Make sure the non-virtual and the virtual versions match. */     \
2086   assert(closure->do_metadata##nv_suffix() == closure->do_metadata(), \
2087       "Inconsistency in do_metadata");                                \
2088   if (closure->do_metadata##nv_suffix())
2089 
2090 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)        \
2091                                                                              \
2092 int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
2093   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2094   /* header */                                                          \
2095   if_do_metadata_checked(closure, nv_suffix) {                          \
2096     closure->do_klass##nv_suffix(obj->klass());                         \
2097   }                                                                     \
2098   InstanceKlass_OOP_MAP_ITERATE(                                        \
2099     obj,                                                                \
2100     SpecializationStats::                                               \
2101       record_do_oop_call##nv_suffix(SpecializationStats::ik);           \
2102     (closure)->do_oop##nv_suffix(p),                                    \
2103     assert_is_in_closed_subset)                                         \
2104   return size_helper();                                                 \
2105 }
2106 
2107 #if INCLUDE_ALL_GCS
2108 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
2109                                                                                 \
2110 int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj,                \
2111                                               OopClosureType* closure) {        \
2112   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
2113   /* header */                                                                  \
2114   if_do_metadata_checked(closure, nv_suffix) {                                  \
2115     closure->do_klass##nv_suffix(obj->klass());                                 \
2116   }                                                                             \
2117   /* instance variables */                                                      \
2118   InstanceKlass_OOP_MAP_REVERSE_ITERATE(                                        \
2119     obj,                                                                        \
2120     SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
2121     (closure)->do_oop##nv_suffix(p),                                            \
2122     assert_is_in_closed_subset)                                                 \
2123    return size_helper();                                                        \
2124 }
2125 #endif // INCLUDE_ALL_GCS
2126 
2127 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
2128                                                                         \
2129 int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj,              \
2130                                                   OopClosureType* closure, \
2131                                                   MemRegion mr) {          \
2132   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
2133   if_do_metadata_checked(closure, nv_suffix) {                           \
2134     if (mr.contains(obj)) {                                              \
2135       closure->do_klass##nv_suffix(obj->klass());                        \
2136     }                                                                    \
2137   }                                                                      \
2138   InstanceKlass_BOUNDED_OOP_MAP_ITERATE(                                 \
2139     obj, mr.start(), mr.end(),                                           \
2140     (closure)->do_oop##nv_suffix(p),                                     \
2141     assert_is_in_closed_subset)                                          \
2142   return size_helper();                                                  \
2143 }
2144 
2145 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2146 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
2147 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2148 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
2149 #if INCLUDE_ALL_GCS
2150 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2151 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
2152 #endif // INCLUDE_ALL_GCS
2153 
2154 int InstanceKlass::oop_adjust_pointers(oop obj) {
2155   int size = size_helper();
2156   InstanceKlass_OOP_MAP_ITERATE( \
2157     obj, \
2158     MarkSweep::adjust_pointer(p), \
2159     assert_is_in)
2160   return size;
2161 }
2162 
2163 #if INCLUDE_ALL_GCS
2164 void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
2165   InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
2166     obj, \
2167     if (PSScavenge::should_scavenge(p)) { \
2168       pm->claim_or_forward_depth(p); \
2169     }, \
2170     assert_nothing )
2171 }
2172 
2173 int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
2174   int size = size_helper();
2175   InstanceKlass_OOP_MAP_ITERATE( \
2176     obj, \
2177     PSParallelCompact::adjust_pointer(p), \
2178     assert_is_in)

2179   return size;
2180 }
2181 
2182 #endif // INCLUDE_ALL_GCS
2183 
2184 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
2185   assert(is_loader_alive(is_alive), "this klass should be live");
2186   if (is_interface()) {
2187     if (ClassUnloading) {
2188       Klass* impl = implementor();
2189       if (impl != NULL) {
2190         if (!impl->is_loader_alive(is_alive)) {
2191           // remove this guy
2192           Klass** klass = adr_implementor();
2193           assert(klass != NULL, "null klass");
2194           if (klass != NULL) {
2195             *klass = NULL;
2196           }
2197         }
2198       }
2199     }
2200   }
2201 }
2202 
2203 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
2204   for (int m = 0; m < methods()->length(); m++) {
2205     MethodData* mdo = methods()->at(m)->method_data();
2206     if (mdo != NULL) {
2207       for (ProfileData* data = mdo->first_data();
2208            mdo->is_valid(data);
2209            data = mdo->next_data(data)) {
2210         data->clean_weak_klass_links(is_alive);
2211       }
2212       ParametersTypeData* parameters = mdo->parameters_type_data();
2213       if (parameters != NULL) {
2214         parameters->clean_weak_klass_links(is_alive);
2215       }
2216     }
2217   }
2218 }
2219 
2220 
2221 static void remove_unshareable_in_class(Klass* k) {
2222   // remove klass's unshareable info
2223   k->remove_unshareable_info();
2224 }
2225 
2226 void InstanceKlass::remove_unshareable_info() {
2227   Klass::remove_unshareable_info();
2228   // Unlink the class
2229   if (is_linked()) {
2230     unlink_class();
2231   }
2232   init_implementor();
2233 
2234   constants()->remove_unshareable_info();
2235 
2236   for (int i = 0; i < methods()->length(); i++) {
2237     Method* m = methods()->at(i);
2238     m->remove_unshareable_info();
2239   }
2240 
2241   // do array classes also.
2242   array_klasses_do(remove_unshareable_in_class);
2243 }
2244 
2245 void restore_unshareable_in_class(Klass* k, TRAPS) {
2246   k->restore_unshareable_info(CHECK);
2247 }
2248 
2249 void InstanceKlass::restore_unshareable_info(TRAPS) {
2250   Klass::restore_unshareable_info(CHECK);
2251   instanceKlassHandle ik(THREAD, this);
2252 
2253   Array<Method*>* methods = ik->methods();
2254   int num_methods = methods->length();
2255   for (int index2 = 0; index2 < num_methods; ++index2) {
2256     methodHandle m(THREAD, methods->at(index2));
2257     m()->link_method(m, CHECK);
2258     // restore method's vtable by calling a virtual function
2259     m->restore_vtable();
2260   }
2261   if (JvmtiExport::has_redefined_a_class()) {
2262     // Reinitialize vtable because RedefineClasses may have changed some
2263     // entries in this vtable for super classes so the CDS vtable might
2264     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2265     // vtables in the shared system dictionary, only the main one.
2266     // It also redefines the itable too so fix that too.
2267     ResourceMark rm(THREAD);
2268     ik->vtable()->initialize_vtable(false, CHECK);
2269     ik->itable()->initialize_itable(false, CHECK);
2270   }
2271 
2272   // restore constant pool resolved references
2273   ik->constants()->restore_unshareable_info(CHECK);
2274 
2275   ik->array_klasses_do(restore_unshareable_in_class, CHECK);
2276 }
2277 
2278 static void clear_all_breakpoints(Method* m) {
2279   m->clear_all_breakpoints();
2280 }
2281 
2282 
2283 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2284   // notify the debugger
2285   if (JvmtiExport::should_post_class_unload()) {
2286     JvmtiExport::post_class_unload(ik);
2287   }
2288 
2289   // notify ClassLoadingService of class unload
2290   ClassLoadingService::notify_class_unloaded(ik);
2291 }
2292 
2293 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2294   // Clean up C heap
2295   ik->release_C_heap_structures();
2296   ik->constants()->release_C_heap_structures();
2297 }
2298 
2299 void InstanceKlass::release_C_heap_structures() {
2300 
2301   // Can't release the constant pool here because the constant pool can be
2302   // deallocated separately from the InstanceKlass for default methods and
2303   // redefine classes.
2304 
2305   // Deallocate oop map cache
2306   if (_oop_map_cache != NULL) {
2307     delete _oop_map_cache;
2308     _oop_map_cache = NULL;
2309   }
2310 
2311   // Deallocate JNI identifiers for jfieldIDs
2312   JNIid::deallocate(jni_ids());
2313   set_jni_ids(NULL);
2314 
2315   jmethodID* jmeths = methods_jmethod_ids_acquire();
2316   if (jmeths != (jmethodID*)NULL) {
2317     release_set_methods_jmethod_ids(NULL);
2318     FreeHeap(jmeths);
2319   }
2320 
2321   // Deallocate MemberNameTable
2322   {
2323     Mutex* lock_or_null = SafepointSynchronize::is_at_safepoint() ? NULL : MemberNameTable_lock;
2324     MutexLockerEx ml(lock_or_null, Mutex::_no_safepoint_check_flag);
2325     MemberNameTable* mnt = member_names();
2326     if (mnt != NULL) {
2327       delete mnt;
2328       set_member_names(NULL);
2329     }
2330   }
2331 
2332   // release dependencies
2333   nmethodBucket* b = _dependencies;
2334   _dependencies = NULL;
2335   while (b != NULL) {
2336     nmethodBucket* next = b->next();
2337     delete b;
2338     b = next;
2339   }
2340 
2341   // Deallocate breakpoint records
2342   if (breakpoints() != 0x0) {
2343     methods_do(clear_all_breakpoints);
2344     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2345   }
2346 
2347   // deallocate information about previous versions
2348   if (_previous_versions != NULL) {
2349     for (int i = _previous_versions->length() - 1; i >= 0; i--) {
2350       PreviousVersionNode * pv_node = _previous_versions->at(i);
2351       delete pv_node;
2352     }
2353     delete _previous_versions;
2354     _previous_versions = NULL;
2355   }
2356 
2357   // deallocate the cached class file
2358   if (_cached_class_file != NULL) {
2359     os::free(_cached_class_file, mtClass);
2360     _cached_class_file = NULL;
2361   }
2362 
2363   // Decrement symbol reference counts associated with the unloaded class.
2364   if (_name != NULL) _name->decrement_refcount();
2365   // unreference array name derived from this class name (arrays of an unloaded
2366   // class can't be referenced anymore).
2367   if (_array_name != NULL)  _array_name->decrement_refcount();
2368   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
2369 
2370   assert(_total_instanceKlass_count >= 1, "Sanity check");
2371   Atomic::dec(&_total_instanceKlass_count);
2372 }
2373 
2374 void InstanceKlass::set_source_debug_extension(char* array, int length) {
2375   if (array == NULL) {
2376     _source_debug_extension = NULL;
2377   } else {
2378     // Adding one to the attribute length in order to store a null terminator
2379     // character could cause an overflow because the attribute length is
2380     // already coded with an u4 in the classfile, but in practice, it's
2381     // unlikely to happen.
2382     assert((length+1) > length, "Overflow checking");
2383     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2384     for (int i = 0; i < length; i++) {
2385       sde[i] = array[i];
2386     }
2387     sde[length] = '\0';
2388     _source_debug_extension = sde;
2389   }
2390 }
2391 
2392 address InstanceKlass::static_field_addr(int offset) {
2393   return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
2394 }
2395 
2396 
2397 const char* InstanceKlass::signature_name() const {
2398   int hash_len = 0;
2399   char hash_buf[40];
2400 
2401   // If this is an anonymous class, append a hash to make the name unique
2402   if (is_anonymous()) {
2403     assert(EnableInvokeDynamic, "EnableInvokeDynamic was not set.");
2404     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2405     sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
2406     hash_len = (int)strlen(hash_buf);
2407   }
2408 
2409   // Get the internal name as a c string
2410   const char* src = (const char*) (name()->as_C_string());
2411   const int src_length = (int)strlen(src);
2412 
2413   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2414 
2415   // Add L as type indicator
2416   int dest_index = 0;
2417   dest[dest_index++] = 'L';
2418 
2419   // Add the actual class name
2420   for (int src_index = 0; src_index < src_length; ) {
2421     dest[dest_index++] = src[src_index++];
2422   }
2423 
2424   // If we have a hash, append it
2425   for (int hash_index = 0; hash_index < hash_len; ) {
2426     dest[dest_index++] = hash_buf[hash_index++];
2427   }
2428 
2429   // Add the semicolon and the NULL
2430   dest[dest_index++] = ';';
2431   dest[dest_index] = '\0';
2432   return dest;
2433 }
2434 
2435 // different verisons of is_same_class_package
2436 bool InstanceKlass::is_same_class_package(Klass* class2) {
2437   Klass* class1 = this;
2438   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2439   Symbol* classname1 = class1->name();
2440 
2441   if (class2->oop_is_objArray()) {
2442     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2443   }
2444   oop classloader2;
2445   if (class2->oop_is_instance()) {
2446     classloader2 = InstanceKlass::cast(class2)->class_loader();
2447   } else {
2448     assert(class2->oop_is_typeArray(), "should be type array");
2449     classloader2 = NULL;
2450   }
2451   Symbol* classname2 = class2->name();
2452 
2453   return InstanceKlass::is_same_class_package(classloader1, classname1,
2454                                               classloader2, classname2);
2455 }
2456 
2457 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
2458   Klass* class1 = this;
2459   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2460   Symbol* classname1 = class1->name();
2461 
2462   return InstanceKlass::is_same_class_package(classloader1, classname1,
2463                                               classloader2, classname2);
2464 }
2465 
2466 // return true if two classes are in the same package, classloader
2467 // and classname information is enough to determine a class's package
2468 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
2469                                           oop class_loader2, Symbol* class_name2) {
2470   if (class_loader1 != class_loader2) {
2471     return false;
2472   } else if (class_name1 == class_name2) {
2473     return true;                // skip painful bytewise comparison
2474   } else {
2475     ResourceMark rm;
2476 
2477     // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
2478     // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
2479     // Otherwise, we just compare jbyte values between the strings.
2480     const jbyte *name1 = class_name1->base();
2481     const jbyte *name2 = class_name2->base();
2482 
2483     const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
2484     const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
2485 
2486     if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
2487       // One of the two doesn't have a package.  Only return true
2488       // if the other one also doesn't have a package.
2489       return last_slash1 == last_slash2;
2490     } else {
2491       // Skip over '['s
2492       if (*name1 == '[') {
2493         do {
2494           name1++;
2495         } while (*name1 == '[');
2496         if (*name1 != 'L') {
2497           // Something is terribly wrong.  Shouldn't be here.
2498           return false;
2499         }
2500       }
2501       if (*name2 == '[') {
2502         do {
2503           name2++;
2504         } while (*name2 == '[');
2505         if (*name2 != 'L') {
2506           // Something is terribly wrong.  Shouldn't be here.
2507           return false;
2508         }
2509       }
2510 
2511       // Check that package part is identical
2512       int length1 = last_slash1 - name1;
2513       int length2 = last_slash2 - name2;
2514 
2515       return UTF8::equal(name1, length1, name2, length2);
2516     }
2517   }
2518 }
2519 
2520 // Returns true iff super_method can be overridden by a method in targetclassname
2521 // See JSL 3rd edition 8.4.6.1
2522 // Assumes name-signature match
2523 // "this" is InstanceKlass of super_method which must exist
2524 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2525 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2526    // Private methods can not be overridden
2527    if (super_method->is_private()) {
2528      return false;
2529    }
2530    // If super method is accessible, then override
2531    if ((super_method->is_protected()) ||
2532        (super_method->is_public())) {
2533      return true;
2534    }
2535    // Package-private methods are not inherited outside of package
2536    assert(super_method->is_package_private(), "must be package private");
2537    return(is_same_class_package(targetclassloader(), targetclassname));
2538 }
2539 
2540 /* defined for now in jvm.cpp, for historical reasons *--
2541 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2542                                                      Symbol*& simple_name_result, TRAPS) {
2543   ...
2544 }
2545 */
2546 
2547 // tell if two classes have the same enclosing class (at package level)
2548 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2549                                                 Klass* class2_oop, TRAPS) {
2550   if (class2_oop == class1())                       return true;
2551   if (!class2_oop->oop_is_instance())  return false;
2552   instanceKlassHandle class2(THREAD, class2_oop);
2553 
2554   // must be in same package before we try anything else
2555   if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2556     return false;
2557 
2558   // As long as there is an outer1.getEnclosingClass,
2559   // shift the search outward.
2560   instanceKlassHandle outer1 = class1;
2561   for (;;) {
2562     // As we walk along, look for equalities between outer1 and class2.
2563     // Eventually, the walks will terminate as outer1 stops
2564     // at the top-level class around the original class.
2565     bool ignore_inner_is_member;
2566     Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2567                                                     CHECK_false);
2568     if (next == NULL)  break;
2569     if (next == class2())  return true;
2570     outer1 = instanceKlassHandle(THREAD, next);
2571   }
2572 
2573   // Now do the same for class2.
2574   instanceKlassHandle outer2 = class2;
2575   for (;;) {
2576     bool ignore_inner_is_member;
2577     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2578                                                     CHECK_false);
2579     if (next == NULL)  break;
2580     // Might as well check the new outer against all available values.
2581     if (next == class1())  return true;
2582     if (next == outer1())  return true;
2583     outer2 = instanceKlassHandle(THREAD, next);
2584   }
2585 
2586   // If by this point we have not found an equality between the
2587   // two classes, we know they are in separate package members.
2588   return false;
2589 }
2590 
2591 
2592 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2593   jint access = access_flags().as_int();
2594 
2595   // But check if it happens to be member class.
2596   instanceKlassHandle ik(THREAD, this);
2597   InnerClassesIterator iter(ik);
2598   for (; !iter.done(); iter.next()) {
2599     int ioff = iter.inner_class_info_index();
2600     // Inner class attribute can be zero, skip it.
2601     // Strange but true:  JVM spec. allows null inner class refs.
2602     if (ioff == 0) continue;
2603 
2604     // only look at classes that are already loaded
2605     // since we are looking for the flags for our self.
2606     Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2607     if ((ik->name() == inner_name)) {
2608       // This is really a member class.
2609       access = iter.inner_access_flags();
2610       break;
2611     }
2612   }
2613   // Remember to strip ACC_SUPER bit
2614   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2615 }
2616 
2617 jint InstanceKlass::jvmti_class_status() const {
2618   jint result = 0;
2619 
2620   if (is_linked()) {
2621     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2622   }
2623 
2624   if (is_initialized()) {
2625     assert(is_linked(), "Class status is not consistent");
2626     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2627   }
2628   if (is_in_error_state()) {
2629     result |= JVMTI_CLASS_STATUS_ERROR;
2630   }
2631   return result;
2632 }
2633 
2634 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2635   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2636   int method_table_offset_in_words = ioe->offset()/wordSize;
2637   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2638                        / itableOffsetEntry::size();
2639 
2640   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2641     // If the interface isn't implemented by the receiver class,
2642     // the VM should throw IncompatibleClassChangeError.
2643     if (cnt >= nof_interfaces) {
2644       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2645     }
2646 
2647     Klass* ik = ioe->interface_klass();
2648     if (ik == holder) break;
2649   }
2650 
2651   itableMethodEntry* ime = ioe->first_method_entry(this);
2652   Method* m = ime[index].method();
2653   if (m == NULL) {
2654     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2655   }
2656   return m;
2657 }
2658 
2659 
2660 #if INCLUDE_JVMTI
2661 // update default_methods for redefineclasses for methods that are
2662 // not yet in the vtable due to concurrent subclass define and superinterface
2663 // redefinition
2664 // Note: those in the vtable, should have been updated via adjust_method_entries
2665 void InstanceKlass::adjust_default_methods(Method** old_methods, Method** new_methods,
2666                                            int methods_length, bool* trace_name_printed) {
2667   // search the default_methods for uses of either obsolete or EMCP methods
2668   if (default_methods() != NULL) {
2669     for (int j = 0; j < methods_length; j++) {
2670       Method* old_method = old_methods[j];
2671       Method* new_method = new_methods[j];
2672 
2673       for (int index = 0; index < default_methods()->length(); index ++) {
2674         if (default_methods()->at(index) == old_method) {
2675           default_methods()->at_put(index, new_method);
2676           if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
2677             if (!(*trace_name_printed)) {
2678               // RC_TRACE_MESG macro has an embedded ResourceMark
2679               RC_TRACE_MESG(("adjust: klassname=%s default methods from name=%s",
2680                              external_name(),
2681                              old_method->method_holder()->external_name()));
2682               *trace_name_printed = true;
2683             }
2684             RC_TRACE(0x00100000, ("default method update: %s(%s) ",
2685                                   new_method->name()->as_C_string(),
2686                                   new_method->signature()->as_C_string()));
2687           }
2688         }
2689       }
2690     }
2691   }
2692 }
2693 #endif // INCLUDE_JVMTI
2694 
2695 // On-stack replacement stuff
2696 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2697   // only one compilation can be active
2698   NEEDS_CLEANUP
2699   // This is a short non-blocking critical region, so the no safepoint check is ok.
2700   OsrList_lock->lock_without_safepoint_check();
2701   assert(n->is_osr_method(), "wrong kind of nmethod");
2702   n->set_osr_link(osr_nmethods_head());
2703   set_osr_nmethods_head(n);
2704   // Raise the highest osr level if necessary
2705   if (TieredCompilation) {
2706     Method* m = n->method();
2707     m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2708   }
2709   // Remember to unlock again
2710   OsrList_lock->unlock();
2711 
2712   // Get rid of the osr methods for the same bci that have lower levels.
2713   if (TieredCompilation) {
2714     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2715       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2716       if (inv != NULL && inv->is_in_use()) {
2717         inv->make_not_entrant();
2718       }
2719     }
2720   }
2721 }
2722 
2723 
2724 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
2725   // This is a short non-blocking critical region, so the no safepoint check is ok.
2726   OsrList_lock->lock_without_safepoint_check();
2727   assert(n->is_osr_method(), "wrong kind of nmethod");
2728   nmethod* last = NULL;
2729   nmethod* cur  = osr_nmethods_head();
2730   int max_level = CompLevel_none;  // Find the max comp level excluding n
2731   Method* m = n->method();
2732   // Search for match
2733   while(cur != NULL && cur != n) {
2734     if (TieredCompilation) {
2735       // Find max level before n
2736       max_level = MAX2(max_level, cur->comp_level());
2737     }
2738     last = cur;
2739     cur = cur->osr_link();
2740   }
2741   nmethod* next = NULL;
2742   if (cur == n) {
2743     next = cur->osr_link();
2744     if (last == NULL) {
2745       // Remove first element
2746       set_osr_nmethods_head(next);
2747     } else {
2748       last->set_osr_link(next);
2749     }
2750   }
2751   n->set_osr_link(NULL);
2752   if (TieredCompilation) {
2753     cur = next;
2754     while (cur != NULL) {
2755       // Find max level after n
2756       max_level = MAX2(max_level, cur->comp_level());
2757       cur = cur->osr_link();
2758     }
2759     m->set_highest_osr_comp_level(max_level);
2760   }
2761   // Remember to unlock again
2762   OsrList_lock->unlock();
2763 }
2764 
2765 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2766   // This is a short non-blocking critical region, so the no safepoint check is ok.
2767   OsrList_lock->lock_without_safepoint_check();
2768   nmethod* osr = osr_nmethods_head();
2769   nmethod* best = NULL;
2770   while (osr != NULL) {
2771     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2772     // There can be a time when a c1 osr method exists but we are waiting
2773     // for a c2 version. When c2 completes its osr nmethod we will trash
2774     // the c1 version and only be able to find the c2 version. However
2775     // while we overflow in the c1 code at back branches we don't want to
2776     // try and switch to the same code as we are already running
2777 
2778     if (osr->method() == m &&
2779         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2780       if (match_level) {
2781         if (osr->comp_level() == comp_level) {
2782           // Found a match - return it.
2783           OsrList_lock->unlock();
2784           return osr;
2785         }
2786       } else {
2787         if (best == NULL || (osr->comp_level() > best->comp_level())) {
2788           if (osr->comp_level() == CompLevel_highest_tier) {
2789             // Found the best possible - return it.
2790             OsrList_lock->unlock();
2791             return osr;
2792           }
2793           best = osr;
2794         }
2795       }
2796     }
2797     osr = osr->osr_link();
2798   }
2799   OsrList_lock->unlock();
2800   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2801     return best;
2802   }
2803   return NULL;
2804 }
2805 
2806 void InstanceKlass::add_member_name(int index, Handle mem_name) {
2807   jweak mem_name_wref = JNIHandles::make_weak_global(mem_name);
2808   MutexLocker ml(MemberNameTable_lock);
2809   assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
2810   DEBUG_ONLY(No_Safepoint_Verifier nsv);
2811 
2812   if (_member_names == NULL) {
2813     _member_names = new (ResourceObj::C_HEAP, mtClass) MemberNameTable(idnum_allocated_count());
2814   }
2815   _member_names->add_member_name(index, mem_name_wref);
2816 }
2817 
2818 oop InstanceKlass::get_member_name(int index) {
2819   MutexLocker ml(MemberNameTable_lock);
2820   assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
2821   DEBUG_ONLY(No_Safepoint_Verifier nsv);
2822 
2823   if (_member_names == NULL) {
2824     return NULL;
2825   }
2826   oop mem_name =_member_names->get_member_name(index);
2827   return mem_name;
2828 }
2829 
2830 // -----------------------------------------------------------------------------------------------------
2831 // Printing
2832 
2833 #ifndef PRODUCT
2834 
2835 #define BULLET  " - "
2836 
2837 static const char* state_names[] = {
2838   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2839 };
2840 
2841 static void print_vtable(intptr_t* start, int len, outputStream* st) {
2842   for (int i = 0; i < len; i++) {
2843     intptr_t e = start[i];
2844     st->print("%d : " INTPTR_FORMAT, i, e);
2845     if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2846       st->print(" ");
2847       ((Metadata*)e)->print_value_on(st);
2848     }
2849     st->cr();
2850   }
2851 }
2852 
2853 void InstanceKlass::print_on(outputStream* st) const {
2854   assert(is_klass(), "must be klass");
2855   Klass::print_on(st);
2856 
2857   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
2858   st->print(BULLET"klass size:        %d", size());                               st->cr();
2859   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
2860   st->print(BULLET"state:             "); st->print_cr(state_names[_init_state]);
2861   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
2862   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
2863   st->print(BULLET"sub:               ");
2864   Klass* sub = subklass();
2865   int n;
2866   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2867     if (n < MaxSubklassPrintSize) {
2868       sub->print_value_on(st);
2869       st->print("   ");
2870     }
2871   }
2872   if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
2873   st->cr();
2874 
2875   if (is_interface()) {
2876     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
2877     if (nof_implementors() == 1) {
2878       st->print_cr(BULLET"implementor:    ");
2879       st->print("   ");
2880       implementor()->print_value_on(st);
2881       st->cr();
2882     }
2883   }
2884 
2885   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2886   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
2887   if (Verbose || WizardMode) {
2888     Array<Method*>* method_array = methods();
2889     for (int i = 0; i < method_array->length(); i++) {
2890       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2891     }
2892   }
2893   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
2894   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
2895   if (Verbose && default_methods() != NULL) {
2896     Array<Method*>* method_array = default_methods();
2897     for (int i = 0; i < method_array->length(); i++) {
2898       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2899     }
2900   }
2901   if (default_vtable_indices() != NULL) {
2902     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
2903   }
2904   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
2905   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2906   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
2907   if (class_loader_data() != NULL) {
2908     st->print(BULLET"class loader data:  ");
2909     class_loader_data()->print_value_on(st);
2910     st->cr();
2911   }
2912   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
2913   if (source_file_name() != NULL) {
2914     st->print(BULLET"source file:       ");
2915     source_file_name()->print_value_on(st);
2916     st->cr();
2917   }
2918   if (source_debug_extension() != NULL) {
2919     st->print(BULLET"source debug extension:       ");
2920     st->print("%s", source_debug_extension());
2921     st->cr();
2922   }
2923   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
2924   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
2925   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
2926   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
2927   {
2928     bool have_pv = false;
2929     PreviousVersionWalker pvw(Thread::current(), (InstanceKlass*)this);
2930     for (PreviousVersionNode * pv_node = pvw.next_previous_version();
2931          pv_node != NULL; pv_node = pvw.next_previous_version()) {
2932       if (!have_pv)
2933         st->print(BULLET"previous version:  ");
2934       have_pv = true;
2935       pv_node->prev_constant_pool()->print_value_on(st);
2936     }
2937     if (have_pv) st->cr();
2938   } // pvw is cleaned up
2939 
2940   if (generic_signature() != NULL) {
2941     st->print(BULLET"generic signature: ");
2942     generic_signature()->print_value_on(st);
2943     st->cr();
2944   }
2945   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
2946   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
2947   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable());  st->cr();
2948   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
2949   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
2950   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
2951   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2952   FieldPrinter print_static_field(st);
2953   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2954   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2955   FieldPrinter print_nonstatic_field(st);
2956   ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
2957 
2958   st->print(BULLET"non-static oop maps: ");
2959   OopMapBlock* map     = start_of_nonstatic_oop_maps();
2960   OopMapBlock* end_map = map + nonstatic_oop_map_count();
2961   while (map < end_map) {
2962     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2963     map++;
2964   }
2965   st->cr();
2966 }
2967 
2968 #endif //PRODUCT
2969 
2970 void InstanceKlass::print_value_on(outputStream* st) const {
2971   assert(is_klass(), "must be klass");
2972   if (Verbose || WizardMode)  access_flags().print_on(st);
2973   name()->print_value_on(st);
2974 }
2975 
2976 #ifndef PRODUCT
2977 
2978 void FieldPrinter::do_field(fieldDescriptor* fd) {
2979   _st->print(BULLET);
2980    if (_obj == NULL) {
2981      fd->print_on(_st);
2982      _st->cr();
2983    } else {
2984      fd->print_on_for(_st, _obj);
2985      _st->cr();
2986    }
2987 }
2988 
2989 
2990 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
2991   Klass::oop_print_on(obj, st);
2992 
2993   if (this == SystemDictionary::String_klass()) {
2994     typeArrayOop value  = java_lang_String::value(obj);
2995     juint        offset = java_lang_String::offset(obj);
2996     juint        length = java_lang_String::length(obj);
2997     if (value != NULL &&
2998         value->is_typeArray() &&
2999         offset          <= (juint) value->length() &&
3000         offset + length <= (juint) value->length()) {
3001       st->print(BULLET"string: ");
3002       Handle h_obj(obj);
3003       java_lang_String::print(h_obj, st);
3004       st->cr();
3005       if (!WizardMode)  return;  // that is enough
3006     }
3007   }
3008 
3009   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3010   FieldPrinter print_field(st, obj);
3011   do_nonstatic_fields(&print_field);
3012 
3013   if (this == SystemDictionary::Class_klass()) {
3014     st->print(BULLET"signature: ");
3015     java_lang_Class::print_signature(obj, st);
3016     st->cr();
3017     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3018     st->print(BULLET"fake entry for mirror: ");
3019     mirrored_klass->print_value_on_maybe_null(st);
3020     st->cr();
3021     Klass* array_klass = java_lang_Class::array_klass(obj);
3022     st->print(BULLET"fake entry for array: ");
3023     array_klass->print_value_on_maybe_null(st);
3024     st->cr();
3025     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3026     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3027     Klass* real_klass = java_lang_Class::as_Klass(obj);
3028     if (real_klass != NULL && real_klass->oop_is_instance()) {
3029       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3030     }
3031   } else if (this == SystemDictionary::MethodType_klass()) {
3032     st->print(BULLET"signature: ");
3033     java_lang_invoke_MethodType::print_signature(obj, st);
3034     st->cr();
3035   }
3036 }
3037 
3038 #endif //PRODUCT
3039 
3040 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3041   st->print("a ");
3042   name()->print_value_on(st);
3043   obj->print_address_on(st);
3044   if (this == SystemDictionary::String_klass()
3045       && java_lang_String::value(obj) != NULL) {
3046     ResourceMark rm;
3047     int len = java_lang_String::length(obj);
3048     int plen = (len < 24 ? len : 12);
3049     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3050     st->print(" = \"%s\"", str);
3051     if (len > plen)
3052       st->print("...[%d]", len);
3053   } else if (this == SystemDictionary::Class_klass()) {
3054     Klass* k = java_lang_Class::as_Klass(obj);
3055     st->print(" = ");
3056     if (k != NULL) {
3057       k->print_value_on(st);
3058     } else {
3059       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3060       st->print("%s", tname ? tname : "type?");
3061     }
3062   } else if (this == SystemDictionary::MethodType_klass()) {
3063     st->print(" = ");
3064     java_lang_invoke_MethodType::print_signature(obj, st);
3065   } else if (java_lang_boxing_object::is_instance(obj)) {
3066     st->print(" = ");
3067     java_lang_boxing_object::print(obj, st);
3068   } else if (this == SystemDictionary::LambdaForm_klass()) {
3069     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3070     if (vmentry != NULL) {
3071       st->print(" => ");
3072       vmentry->print_value_on(st);
3073     }
3074   } else if (this == SystemDictionary::MemberName_klass()) {
3075     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3076     if (vmtarget != NULL) {
3077       st->print(" = ");
3078       vmtarget->print_value_on(st);
3079     } else {
3080       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3081       st->print(".");
3082       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3083     }
3084   }
3085 }
3086 
3087 const char* InstanceKlass::internal_name() const {
3088   return external_name();
3089 }
3090 
3091 #if INCLUDE_SERVICES
3092 // Size Statistics
3093 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3094   Klass::collect_statistics(sz);
3095 
3096   sz->_inst_size  = HeapWordSize * size_helper();
3097   sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
3098   sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
3099   sz->_nonstatic_oopmap_bytes = HeapWordSize *
3100         ((is_interface() || is_anonymous()) ?
3101          align_object_offset(nonstatic_oop_map_size()) :
3102          nonstatic_oop_map_size());
3103 
3104   int n = 0;
3105   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
3106   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
3107   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
3108   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3109   n += (sz->_fields_bytes                = sz->count_array(fields()));
3110   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
3111   sz->_ro_bytes += n;
3112 
3113   const ConstantPool* cp = constants();
3114   if (cp) {
3115     cp->collect_statistics(sz);
3116   }
3117 
3118   const Annotations* anno = annotations();
3119   if (anno) {
3120     anno->collect_statistics(sz);
3121   }
3122 
3123   const Array<Method*>* methods_array = methods();
3124   if (methods()) {
3125     for (int i = 0; i < methods_array->length(); i++) {
3126       Method* method = methods_array->at(i);
3127       if (method) {
3128         sz->_method_count ++;
3129         method->collect_statistics(sz);
3130       }
3131     }
3132   }
3133 }
3134 #endif // INCLUDE_SERVICES
3135 
3136 // Verification
3137 
3138 class VerifyFieldClosure: public OopClosure {
3139  protected:
3140   template <class T> void do_oop_work(T* p) {
3141     oop obj = oopDesc::load_decode_heap_oop(p);
3142     if (!obj->is_oop_or_null()) {
3143       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
3144       Universe::print();
3145       guarantee(false, "boom");
3146     }
3147   }
3148  public:
3149   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3150   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3151 };
3152 
3153 void InstanceKlass::verify_on(outputStream* st, bool check_dictionary) {
3154 #ifndef PRODUCT
3155   // Avoid redundant verifies, this really should be in product.
3156   if (_verify_count == Universe::verify_count()) return;
3157   _verify_count = Universe::verify_count();
3158 #endif
3159 
3160   // Verify Klass
3161   Klass::verify_on(st, check_dictionary);
3162 
3163   // Verify that klass is present in SystemDictionary if not already
3164   // verifying the SystemDictionary.
3165   if (is_loaded() && !is_anonymous() && check_dictionary) {
3166     Symbol* h_name = name();
3167     SystemDictionary::verify_obj_klass_present(h_name, class_loader_data());
3168   }
3169 
3170   // Verify vtables
3171   if (is_linked()) {
3172     ResourceMark rm;
3173     // $$$ This used to be done only for m/s collections.  Doing it
3174     // always seemed a valid generalization.  (DLD -- 6/00)
3175     vtable()->verify(st);
3176   }
3177 
3178   // Verify first subklass
3179   if (subklass_oop() != NULL) {
3180     guarantee(subklass_oop()->is_klass(), "should be klass");
3181   }
3182 
3183   // Verify siblings
3184   Klass* super = this->super();
3185   Klass* sib = next_sibling();
3186   if (sib != NULL) {
3187     if (sib == this) {
3188       fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
3189     }
3190 
3191     guarantee(sib->is_klass(), "should be klass");
3192     guarantee(sib->super() == super, "siblings should have same superklass");
3193   }
3194 
3195   // Verify implementor fields
3196   Klass* im = implementor();
3197   if (im != NULL) {
3198     guarantee(is_interface(), "only interfaces should have implementor set");
3199     guarantee(im->is_klass(), "should be klass");
3200     guarantee(!im->is_interface() || im == this,
3201       "implementors cannot be interfaces");
3202   }
3203 
3204   // Verify local interfaces
3205   if (local_interfaces()) {
3206     Array<Klass*>* local_interfaces = this->local_interfaces();
3207     for (int j = 0; j < local_interfaces->length(); j++) {
3208       Klass* e = local_interfaces->at(j);
3209       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3210     }
3211   }
3212 
3213   // Verify transitive interfaces
3214   if (transitive_interfaces() != NULL) {
3215     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3216     for (int j = 0; j < transitive_interfaces->length(); j++) {
3217       Klass* e = transitive_interfaces->at(j);
3218       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3219     }
3220   }
3221 
3222   // Verify methods
3223   if (methods() != NULL) {
3224     Array<Method*>* methods = this->methods();
3225     for (int j = 0; j < methods->length(); j++) {
3226       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3227     }
3228     for (int j = 0; j < methods->length() - 1; j++) {
3229       Method* m1 = methods->at(j);
3230       Method* m2 = methods->at(j + 1);
3231       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3232     }
3233   }
3234 
3235   // Verify method ordering
3236   if (method_ordering() != NULL) {
3237     Array<int>* method_ordering = this->method_ordering();
3238     int length = method_ordering->length();
3239     if (JvmtiExport::can_maintain_original_method_order() ||
3240         ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3241       guarantee(length == methods()->length(), "invalid method ordering length");
3242       jlong sum = 0;
3243       for (int j = 0; j < length; j++) {
3244         int original_index = method_ordering->at(j);
3245         guarantee(original_index >= 0, "invalid method ordering index");
3246         guarantee(original_index < length, "invalid method ordering index");
3247         sum += original_index;
3248       }
3249       // Verify sum of indices 0,1,...,length-1
3250       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3251     } else {
3252       guarantee(length == 0, "invalid method ordering length");
3253     }
3254   }
3255 
3256   // Verify default methods
3257   if (default_methods() != NULL) {
3258     Array<Method*>* methods = this->default_methods();
3259     for (int j = 0; j < methods->length(); j++) {
3260       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3261     }
3262     for (int j = 0; j < methods->length() - 1; j++) {
3263       Method* m1 = methods->at(j);
3264       Method* m2 = methods->at(j + 1);
3265       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3266     }
3267   }
3268 
3269   // Verify JNI static field identifiers
3270   if (jni_ids() != NULL) {
3271     jni_ids()->verify(this);
3272   }
3273 
3274   // Verify other fields
3275   if (array_klasses() != NULL) {
3276     guarantee(array_klasses()->is_klass(), "should be klass");
3277   }
3278   if (constants() != NULL) {
3279     guarantee(constants()->is_constantPool(), "should be constant pool");
3280   }
3281   const Klass* host = host_klass();
3282   if (host != NULL) {
3283     guarantee(host->is_klass(), "should be klass");
3284   }
3285 }
3286 
3287 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3288   Klass::oop_verify_on(obj, st);
3289   VerifyFieldClosure blk;
3290   obj->oop_iterate_no_header(&blk);
3291 }
3292 
3293 
3294 // JNIid class for jfieldIDs only
3295 // Note to reviewers:
3296 // These JNI functions are just moved over to column 1 and not changed
3297 // in the compressed oops workspace.
3298 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3299   _holder = holder;
3300   _offset = offset;
3301   _next = next;
3302   debug_only(_is_static_field_id = false;)
3303 }
3304 
3305 
3306 JNIid* JNIid::find(int offset) {
3307   JNIid* current = this;
3308   while (current != NULL) {
3309     if (current->offset() == offset) return current;
3310     current = current->next();
3311   }
3312   return NULL;
3313 }
3314 
3315 void JNIid::deallocate(JNIid* current) {
3316   while (current != NULL) {
3317     JNIid* next = current->next();
3318     delete current;
3319     current = next;
3320   }
3321 }
3322 
3323 
3324 void JNIid::verify(Klass* holder) {
3325   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3326   int end_field_offset;
3327   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3328 
3329   JNIid* current = this;
3330   while (current != NULL) {
3331     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3332 #ifdef ASSERT
3333     int o = current->offset();
3334     if (current->is_static_field_id()) {
3335       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3336     }
3337 #endif
3338     current = current->next();
3339   }
3340 }
3341 
3342 
3343 #ifdef ASSERT
3344 void InstanceKlass::set_init_state(ClassState state) {
3345   bool good_state = is_shared() ? (_init_state <= state)
3346                                                : (_init_state < state);
3347   assert(good_state || state == allocated, "illegal state transition");
3348   _init_state = (u1)state;
3349 }
3350 #endif
3351 
3352 
3353 // RedefineClasses() support for previous versions:
3354 
3355 // Purge previous versions
3356 static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
3357   if (ik->previous_versions() != NULL) {
3358     // This klass has previous versions so see what we can cleanup
3359     // while it is safe to do so.
3360 
3361     int deleted_count = 0;    // leave debugging breadcrumbs
3362     int live_count = 0;
3363     ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
3364                        ClassLoaderData::the_null_class_loader_data() :
3365                        ik->class_loader_data();
3366 
3367     // RC_TRACE macro has an embedded ResourceMark
3368     RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
3369       ik->external_name(), ik->previous_versions()->length()));
3370 
3371     for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
3372       // check the previous versions array
3373       PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
3374       ConstantPool* cp_ref = pv_node->prev_constant_pool();
3375       assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
3376 
3377       ConstantPool* pvcp = cp_ref;
3378       if (!pvcp->on_stack()) {
3379         // If the constant pool isn't on stack, none of the methods
3380         // are executing.  Delete all the methods, the constant pool and
3381         // and this previous version node.
3382         GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3383         if (method_refs != NULL) {
3384           for (int j = method_refs->length() - 1; j >= 0; j--) {
3385             Method* method = method_refs->at(j);
3386             assert(method != NULL, "method ref was unexpectedly cleared");
3387             method_refs->remove_at(j);
3388             // method will be freed with associated class.
3389           }
3390         }
3391         // Remove the constant pool
3392         delete pv_node;
3393         // Since we are traversing the array backwards, we don't have to
3394         // do anything special with the index.
3395         ik->previous_versions()->remove_at(i);
3396         deleted_count++;
3397         continue;
3398       } else {
3399         RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
3400         assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3401         guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3402         live_count++;
3403       }
3404 
3405       // At least one method is live in this previous version, clean out
3406       // the others or mark them as obsolete.
3407       GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3408       if (method_refs != NULL) {
3409         RC_TRACE(0x00000200, ("purge: previous methods length=%d",
3410           method_refs->length()));
3411         for (int j = method_refs->length() - 1; j >= 0; j--) {
3412           Method* method = method_refs->at(j);
3413           assert(method != NULL, "method ref was unexpectedly cleared");
3414 
3415           // Remove the emcp method if it's not executing
3416           // If it's been made obsolete by a redefinition of a non-emcp
3417           // method, mark it as obsolete but leave it to clean up later.
3418           if (!method->on_stack()) {
3419             method_refs->remove_at(j);
3420           } else if (emcp_method_count == 0) {
3421             method->set_is_obsolete();
3422           } else {
3423             // RC_TRACE macro has an embedded ResourceMark
3424             RC_TRACE(0x00000200,
3425               ("purge: %s(%s): prev method @%d in version @%d is alive",
3426               method->name()->as_C_string(),
3427               method->signature()->as_C_string(), j, i));
3428           }
3429         }
3430       }
3431     }
3432     assert(ik->previous_versions()->length() == live_count, "sanity check");
3433     RC_TRACE(0x00000200,
3434       ("purge: previous version stats: live=%d, deleted=%d", live_count,
3435       deleted_count));
3436   }
3437 }
3438 
3439 // External interface for use during class unloading.
3440 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
3441   // Call with >0 emcp methods since they are not currently being redefined.
3442   purge_previous_versions_internal(ik, 1);
3443 }
3444 
3445 
3446 // Potentially add an information node that contains pointers to the
3447 // interesting parts of the previous version of the_class.
3448 // This is also where we clean out any unused references.
3449 // Note that while we delete nodes from the _previous_versions
3450 // array, we never delete the array itself until the klass is
3451 // unloaded. The has_been_redefined() query depends on that fact.
3452 //
3453 void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
3454        BitMap* emcp_methods, int emcp_method_count) {
3455   assert(Thread::current()->is_VM_thread(),
3456          "only VMThread can add previous versions");
3457 
3458   if (_previous_versions == NULL) {
3459     // This is the first previous version so make some space.
3460     // Start with 2 elements under the assumption that the class
3461     // won't be redefined much.
3462     _previous_versions =  new (ResourceObj::C_HEAP, mtClass)
3463                             GrowableArray<PreviousVersionNode *>(2, true);
3464   }
3465 
3466   ConstantPool* cp_ref = ikh->constants();
3467 
3468   // RC_TRACE macro has an embedded ResourceMark
3469   RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
3470                         "on_stack=%d",
3471     ikh->external_name(), _previous_versions->length(), emcp_method_count,
3472     cp_ref->on_stack()));
3473 
3474   // If the constant pool for this previous version of the class
3475   // is not marked as being on the stack, then none of the methods
3476   // in this previous version of the class are on the stack so
3477   // we don't need to create a new PreviousVersionNode. However,
3478   // we still need to examine older previous versions below.
3479   Array<Method*>* old_methods = ikh->methods();
3480 
3481   if (cp_ref->on_stack()) {
3482     PreviousVersionNode * pv_node = NULL;
3483     if (emcp_method_count == 0) {
3484       // non-shared ConstantPool gets a reference
3485       pv_node = new PreviousVersionNode(cp_ref, NULL);
3486       RC_TRACE(0x00000400,
3487           ("add: all methods are obsolete; flushing any EMCP refs"));
3488     } else {
3489       int local_count = 0;
3490       GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
3491           GrowableArray<Method*>(emcp_method_count, true);
3492       for (int i = 0; i < old_methods->length(); i++) {
3493         if (emcp_methods->at(i)) {
3494             // this old method is EMCP. Save it only if it's on the stack
3495             Method* old_method = old_methods->at(i);
3496             if (old_method->on_stack()) {
3497               method_refs->append(old_method);
3498             }
3499           if (++local_count >= emcp_method_count) {
3500             // no more EMCP methods so bail out now
3501             break;
3502           }
3503         }
3504       }
3505       // non-shared ConstantPool gets a reference
3506       pv_node = new PreviousVersionNode(cp_ref, method_refs);
3507     }
3508     // append new previous version.
3509     _previous_versions->append(pv_node);
3510   }
3511 
3512   // Since the caller is the VMThread and we are at a safepoint, this
3513   // is a good time to clear out unused references.
3514 
3515   RC_TRACE(0x00000400, ("add: previous version length=%d",
3516     _previous_versions->length()));
3517 
3518   // Purge previous versions not executing on the stack
3519   purge_previous_versions_internal(this, emcp_method_count);
3520 
3521   int obsolete_method_count = old_methods->length() - emcp_method_count;
3522 
3523   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3524       _previous_versions->length() > 0) {
3525     // We have a mix of obsolete and EMCP methods so we have to
3526     // clear out any matching EMCP method entries the hard way.
3527     int local_count = 0;
3528     for (int i = 0; i < old_methods->length(); i++) {
3529       if (!emcp_methods->at(i)) {
3530         // only obsolete methods are interesting
3531         Method* old_method = old_methods->at(i);
3532         Symbol* m_name = old_method->name();
3533         Symbol* m_signature = old_method->signature();
3534 
3535         // we might not have added the last entry
3536         for (int j = _previous_versions->length() - 1; j >= 0; j--) {
3537           // check the previous versions array for non executing obsolete methods
3538           PreviousVersionNode * pv_node = _previous_versions->at(j);
3539 
3540           GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
3541           if (method_refs == NULL) {
3542             // We have run into a PreviousVersion generation where
3543             // all methods were made obsolete during that generation's
3544             // RedefineClasses() operation. At the time of that
3545             // operation, all EMCP methods were flushed so we don't
3546             // have to go back any further.
3547             //
3548             // A NULL method_refs is different than an empty method_refs.
3549             // We cannot infer any optimizations about older generations
3550             // from an empty method_refs for the current generation.
3551             break;
3552           }
3553 
3554           for (int k = method_refs->length() - 1; k >= 0; k--) {
3555             Method* method = method_refs->at(k);
3556 
3557             if (!method->is_obsolete() &&
3558                 method->name() == m_name &&
3559                 method->signature() == m_signature) {
3560               // The current RedefineClasses() call has made all EMCP
3561               // versions of this method obsolete so mark it as obsolete
3562               // and remove the reference.
3563               RC_TRACE(0x00000400,
3564                 ("add: %s(%s): flush obsolete method @%d in version @%d",
3565                 m_name->as_C_string(), m_signature->as_C_string(), k, j));
3566 
3567               method->set_is_obsolete();
3568               // Leave obsolete methods on the previous version list to
3569               // clean up later.
3570               break;
3571             }
3572           }
3573 
3574           // The previous loop may not find a matching EMCP method, but
3575           // that doesn't mean that we can optimize and not go any
3576           // further back in the PreviousVersion generations. The EMCP
3577           // method for this generation could have already been deleted,
3578           // but there still may be an older EMCP method that has not
3579           // been deleted.
3580         }
3581 
3582         if (++local_count >= obsolete_method_count) {
3583           // no more obsolete methods so bail out now
3584           break;
3585         }
3586       }
3587     }
3588   }
3589 } // end add_previous_version()
3590 
3591 
3592 // Determine if InstanceKlass has a previous version.
3593 bool InstanceKlass::has_previous_version() const {
3594   return (_previous_versions != NULL && _previous_versions->length() > 0);
3595 } // end has_previous_version()
3596 
3597 
3598 Method* InstanceKlass::method_with_idnum(int idnum) {
3599   Method* m = NULL;
3600   if (idnum < methods()->length()) {
3601     m = methods()->at(idnum);
3602   }
3603   if (m == NULL || m->method_idnum() != idnum) {
3604     for (int index = 0; index < methods()->length(); ++index) {
3605       m = methods()->at(index);
3606       if (m->method_idnum() == idnum) {
3607         return m;
3608       }
3609     }
3610     // None found, return null for the caller to handle.
3611     return NULL;
3612   }
3613   return m;
3614 }
3615 
3616 jint InstanceKlass::get_cached_class_file_len() {
3617   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3618 }
3619 
3620 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3621   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3622 }
3623 
3624 
3625 // Construct a PreviousVersionNode entry for the array hung off
3626 // the InstanceKlass.
3627 PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
3628   GrowableArray<Method*>* prev_EMCP_methods) {
3629 
3630   _prev_constant_pool = prev_constant_pool;
3631   _prev_EMCP_methods = prev_EMCP_methods;
3632 }
3633 
3634 
3635 // Destroy a PreviousVersionNode
3636 PreviousVersionNode::~PreviousVersionNode() {
3637   if (_prev_constant_pool != NULL) {
3638     _prev_constant_pool = NULL;
3639   }
3640 
3641   if (_prev_EMCP_methods != NULL) {
3642     delete _prev_EMCP_methods;
3643   }
3644 }
3645 
3646 // Construct a helper for walking the previous versions array
3647 PreviousVersionWalker::PreviousVersionWalker(Thread* thread, InstanceKlass *ik) {
3648   _thread = thread;
3649   _previous_versions = ik->previous_versions();
3650   _current_index = 0;
3651   _current_p = NULL;
3652   _current_constant_pool_handle = constantPoolHandle(thread, ik->constants());
3653 }
3654 
3655 
3656 // Return the interesting information for the next previous version
3657 // of the klass. Returns NULL if there are no more previous versions.
3658 PreviousVersionNode* PreviousVersionWalker::next_previous_version() {
3659   if (_previous_versions == NULL) {
3660     // no previous versions so nothing to return
3661     return NULL;
3662   }
3663 
3664   _current_p = NULL;  // reset to NULL
3665   _current_constant_pool_handle = NULL;
3666 
3667   int length = _previous_versions->length();
3668 
3669   while (_current_index < length) {
3670     PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
3671 
3672     // Save a handle to the constant pool for this previous version,
3673     // which keeps all the methods from being deallocated.
3674     _current_constant_pool_handle = constantPoolHandle(_thread, pv_node->prev_constant_pool());
3675     _current_p = pv_node;
3676     return pv_node;
3677   }
3678 
3679   return NULL;
3680 } // end next_previous_version()
--- EOF ---