1 /*
   2  * Copyright (c) 1997, 2015, 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/shared/collectedHeap.inline.hpp"
  32 #include "gc/shared/specialized_oop_closures.hpp"
  33 #include "interpreter/oopMapCache.hpp"
  34 #include "interpreter/rewriter.hpp"
  35 #include "jvmtifiles/jvmti.h"
  36 #include "memory/heapInspection.hpp"
  37 #include "memory/iterator.inline.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.inline.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/jvmtiRedefineClasses.hpp"
  51 #include "prims/jvmtiRedefineClassesTrace.hpp"
  52 #include "prims/jvmtiThreadState.hpp"
  53 #include "prims/methodComparator.hpp"
  54 #include "runtime/atomic.inline.hpp"
  55 #include "runtime/fieldDescriptor.hpp"
  56 #include "runtime/handles.inline.hpp"
  57 #include "runtime/javaCalls.hpp"
  58 #include "runtime/mutexLocker.hpp"
  59 #include "runtime/orderAccess.inline.hpp"
  60 #include "runtime/thread.inline.hpp"
  61 #include "services/classLoadingService.hpp"
  62 #include "services/threadService.hpp"
  63 #include "utilities/dtrace.hpp"
  64 #include "utilities/macros.hpp"
  65 #ifdef COMPILER1
  66 #include "c1/c1_Compiler.hpp"
  67 #endif
  68 
  69 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  70 
  71 #ifdef DTRACE_ENABLED
  72 
  73 
  74 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
  75 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
  76 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
  77 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
  78 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
  79 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
  80 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
  81 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
  82 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
  83   {                                                              \
  84     char* data = NULL;                                           \
  85     int len = 0;                                                 \
  86     Symbol* name = (clss)->name();                               \
  87     if (name != NULL) {                                          \
  88       data = (char*)name->bytes();                               \
  89       len = name->utf8_length();                                 \
  90     }                                                            \
  91     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
  92       data, len, (clss)->class_loader(), thread_type);           \
  93   }
  94 
  95 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
  96   {                                                              \
  97     char* data = NULL;                                           \
  98     int len = 0;                                                 \
  99     Symbol* name = (clss)->name();                               \
 100     if (name != NULL) {                                          \
 101       data = (char*)name->bytes();                               \
 102       len = name->utf8_length();                                 \
 103     }                                                            \
 104     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 105       data, len, (clss)->class_loader(), thread_type, wait);     \
 106   }
 107 
 108 #else //  ndef DTRACE_ENABLED
 109 
 110 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
 111 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
 112 
 113 #endif //  ndef DTRACE_ENABLED
 114 
 115 volatile int InstanceKlass::_total_instanceKlass_count = 0;
 116 
 117 InstanceKlass* InstanceKlass::allocate_instance_klass(
 118                                               ClassLoaderData* loader_data,
 119                                               int vtable_len,
 120                                               int itable_len,
 121                                               int static_field_size,
 122                                               int nonstatic_oop_map_size,
 123                                               ReferenceType rt,
 124                                               AccessFlags access_flags,
 125                                               Symbol* name,
 126                                               Klass* super_klass,
 127                                               bool is_anonymous,
 128                                               TRAPS) {
 129 
 130   int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
 131                                  access_flags.is_interface(), is_anonymous);
 132 
 133   // Allocation
 134   InstanceKlass* ik;
 135   if (rt == REF_NONE) {
 136     if (name == vmSymbols::java_lang_Class()) {
 137       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
 138         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 139         access_flags, is_anonymous);
 140     } else if (name == vmSymbols::java_lang_ClassLoader() ||
 141           (SystemDictionary::ClassLoader_klass_loaded() &&
 142           super_klass != NULL &&
 143           super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
 144       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
 145         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 146         access_flags, is_anonymous);
 147     } else {
 148       // normal class
 149       ik = new (loader_data, size, THREAD) InstanceKlass(
 150         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 151         access_flags, is_anonymous);
 152     }
 153   } else {
 154     // reference klass
 155     ik = new (loader_data, size, THREAD) InstanceRefKlass(
 156         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
 157         access_flags, is_anonymous);
 158   }
 159 
 160   // Check for pending exception before adding to the loader data and incrementing
 161   // class count.  Can get OOM here.
 162   if (HAS_PENDING_EXCEPTION) {
 163     return NULL;
 164   }
 165 
 166   // Add all classes to our internal class loader list here,
 167   // including classes in the bootstrap (NULL) class loader.
 168   loader_data->add_class(ik);
 169 
 170   Atomic::inc(&_total_instanceKlass_count);
 171   return ik;
 172 }
 173 
 174 
 175 // copy method ordering from resource area to Metaspace
 176 void InstanceKlass::copy_method_ordering(intArray* m, TRAPS) {
 177   if (m != NULL) {
 178     // allocate a new array and copy contents (memcpy?)
 179     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
 180     for (int i = 0; i < m->length(); i++) {
 181       _method_ordering->at_put(i, m->at(i));
 182     }
 183   } else {
 184     _method_ordering = Universe::the_empty_int_array();
 185   }
 186 }
 187 
 188 // create a new array of vtable_indices for default methods
 189 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
 190   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
 191   assert(default_vtable_indices() == NULL, "only create once");
 192   set_default_vtable_indices(vtable_indices);
 193   return vtable_indices;
 194 }
 195 
 196 InstanceKlass::InstanceKlass(int vtable_len,
 197                              int itable_len,
 198                              int static_field_size,
 199                              int nonstatic_oop_map_size,
 200                              ReferenceType rt,
 201                              AccessFlags access_flags,
 202                              bool is_anonymous) {
 203   No_Safepoint_Verifier no_safepoint; // until k becomes parsable
 204 
 205   int iksize = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
 206                                    access_flags.is_interface(), is_anonymous);
 207 
 208   set_vtable_length(vtable_len);
 209   set_itable_length(itable_len);
 210   set_static_field_size(static_field_size);
 211   set_nonstatic_oop_map_size(nonstatic_oop_map_size);
 212   set_access_flags(access_flags);
 213   _misc_flags = 0;  // initialize to zero
 214   set_is_anonymous(is_anonymous);
 215   assert(size() == iksize, "wrong size for object");
 216 
 217   set_array_klasses(NULL);
 218   set_methods(NULL);
 219   set_method_ordering(NULL);
 220   set_default_methods(NULL);
 221   set_default_vtable_indices(NULL);
 222   set_local_interfaces(NULL);
 223   set_transitive_interfaces(NULL);
 224   init_implementor();
 225   set_fields(NULL, 0);
 226   set_constants(NULL);
 227   set_class_loader_data(NULL);
 228   set_source_file_name_index(0);
 229   set_source_debug_extension(NULL, 0);
 230   set_array_name(NULL);
 231   set_inner_classes(NULL);
 232   set_static_oop_field_count(0);
 233   set_nonstatic_field_size(0);
 234   set_is_marked_dependent(false);
 235   set_has_unloaded_dependent(false);
 236   set_init_state(InstanceKlass::allocated);
 237   set_init_thread(NULL);
 238   set_reference_type(rt);
 239   set_oop_map_cache(NULL);
 240   set_jni_ids(NULL);
 241   set_osr_nmethods_head(NULL);
 242   set_breakpoints(NULL);
 243   init_previous_versions();
 244   set_generic_signature_index(0);
 245   release_set_methods_jmethod_ids(NULL);
 246   set_annotations(NULL);
 247   set_jvmti_cached_class_field_map(NULL);
 248   set_initial_method_idnum(0);
 249   _dependencies = NULL;
 250   set_jvmti_cached_class_field_map(NULL);
 251   set_cached_class_file(NULL);
 252   set_initial_method_idnum(0);
 253   set_minor_version(0);
 254   set_major_version(0);
 255   NOT_PRODUCT(_verify_count = 0;)
 256 
 257   // initialize the non-header words to zero
 258   intptr_t* p = (intptr_t*)this;
 259   for (int index = InstanceKlass::header_size(); index < iksize; index++) {
 260     p[index] = NULL_WORD;
 261   }
 262 
 263   // Set temporary value until parseClassFile updates it with the real instance
 264   // size.
 265   set_layout_helper(Klass::instance_layout_helper(0, true));
 266 }
 267 
 268 
 269 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 270                                        Array<Method*>* methods) {
 271   if (methods != NULL && methods != Universe::the_empty_method_array() &&
 272       !methods->is_shared()) {
 273     for (int i = 0; i < methods->length(); i++) {
 274       Method* method = methods->at(i);
 275       if (method == NULL) continue;  // maybe null if error processing
 276       // Only want to delete methods that are not executing for RedefineClasses.
 277       // The previous version will point to them so they're not totally dangling
 278       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 279       MetadataFactory::free_metadata(loader_data, method);
 280     }
 281     MetadataFactory::free_array<Method*>(loader_data, methods);
 282   }
 283 }
 284 
 285 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 286                                           Klass* super_klass,
 287                                           Array<Klass*>* local_interfaces,
 288                                           Array<Klass*>* transitive_interfaces) {
 289   // Only deallocate transitive interfaces if not empty, same as super class
 290   // or same as local interfaces.  See code in parseClassFile.
 291   Array<Klass*>* ti = transitive_interfaces;
 292   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
 293     // check that the interfaces don't come from super class
 294     Array<Klass*>* sti = (super_klass == NULL) ? NULL :
 295                     InstanceKlass::cast(super_klass)->transitive_interfaces();
 296     if (ti != sti && ti != NULL && !ti->is_shared()) {
 297       MetadataFactory::free_array<Klass*>(loader_data, ti);
 298     }
 299   }
 300 
 301   // local interfaces can be empty
 302   if (local_interfaces != Universe::the_empty_klass_array() &&
 303       local_interfaces != NULL && !local_interfaces->is_shared()) {
 304     MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
 305   }
 306 }
 307 
 308 // This function deallocates the metadata and C heap pointers that the
 309 // InstanceKlass points to.
 310 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 311 
 312   // Orphan the mirror first, CMS thinks it's still live.
 313   if (java_mirror() != NULL) {
 314     java_lang_Class::set_klass(java_mirror(), NULL);
 315   }
 316 
 317   // Need to take this class off the class loader data list.
 318   loader_data->remove_class(this);
 319 
 320   // The array_klass for this class is created later, after error handling.
 321   // For class redefinition, we keep the original class so this scratch class
 322   // doesn't have an array class.  Either way, assert that there is nothing
 323   // to deallocate.
 324   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
 325 
 326   // Release C heap allocated data that this might point to, which includes
 327   // reference counting symbol names.
 328   release_C_heap_structures();
 329 
 330   deallocate_methods(loader_data, methods());
 331   set_methods(NULL);
 332 
 333   if (method_ordering() != NULL &&
 334       method_ordering() != Universe::the_empty_int_array() &&
 335       !method_ordering()->is_shared()) {
 336     MetadataFactory::free_array<int>(loader_data, method_ordering());
 337   }
 338   set_method_ordering(NULL);
 339 
 340   // default methods can be empty
 341   if (default_methods() != NULL &&
 342       default_methods() != Universe::the_empty_method_array() &&
 343       !default_methods()->is_shared()) {
 344     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 345   }
 346   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 347   set_default_methods(NULL);
 348 
 349   // default methods vtable indices can be empty
 350   if (default_vtable_indices() != NULL &&
 351       !default_vtable_indices()->is_shared()) {
 352     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 353   }
 354   set_default_vtable_indices(NULL);
 355 
 356 
 357   // This array is in Klass, but remove it with the InstanceKlass since
 358   // this place would be the only caller and it can share memory with transitive
 359   // interfaces.
 360   if (secondary_supers() != NULL &&
 361       secondary_supers() != Universe::the_empty_klass_array() &&
 362       secondary_supers() != transitive_interfaces() &&
 363       !secondary_supers()->is_shared()) {
 364     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 365   }
 366   set_secondary_supers(NULL);
 367 
 368   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 369   set_transitive_interfaces(NULL);
 370   set_local_interfaces(NULL);
 371 
 372   if (fields() != NULL && !fields()->is_shared()) {
 373     MetadataFactory::free_array<jushort>(loader_data, fields());
 374   }
 375   set_fields(NULL, 0);
 376 
 377   // If a method from a redefined class is using this constant pool, don't
 378   // delete it, yet.  The new class's previous version will point to this.
 379   if (constants() != NULL) {
 380     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 381     if (!constants()->is_shared()) {
 382       MetadataFactory::free_metadata(loader_data, constants());
 383     }
 384     // Delete any cached resolution errors for the constant pool
 385     SystemDictionary::delete_resolution_error(constants());
 386 
 387     set_constants(NULL);
 388   }
 389 
 390   if (inner_classes() != NULL &&
 391       inner_classes() != Universe::the_empty_short_array() &&
 392       !inner_classes()->is_shared()) {
 393     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 394   }
 395   set_inner_classes(NULL);
 396 
 397   // We should deallocate the Annotations instance if it's not in shared spaces.
 398   if (annotations() != NULL && !annotations()->is_shared()) {
 399     MetadataFactory::free_metadata(loader_data, annotations());
 400   }
 401   set_annotations(NULL);
 402 }
 403 
 404 bool InstanceKlass::should_be_initialized() const {
 405   return !is_initialized();
 406 }
 407 
 408 klassVtable* InstanceKlass::vtable() const {
 409   return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
 410 }
 411 
 412 klassItable* InstanceKlass::itable() const {
 413   return new klassItable(instanceKlassHandle(this));
 414 }
 415 
 416 void InstanceKlass::eager_initialize(Thread *thread) {
 417   if (!EagerInitialization) return;
 418 
 419   if (this->is_not_initialized()) {
 420     // abort if the the class has a class initializer
 421     if (this->class_initializer() != NULL) return;
 422 
 423     // abort if it is java.lang.Object (initialization is handled in genesis)
 424     Klass* super = this->super();
 425     if (super == NULL) return;
 426 
 427     // abort if the super class should be initialized
 428     if (!InstanceKlass::cast(super)->is_initialized()) return;
 429 
 430     // call body to expose the this pointer
 431     instanceKlassHandle this_k(thread, this);
 432     eager_initialize_impl(this_k);
 433   }
 434 }
 435 
 436 // JVMTI spec thinks there are signers and protection domain in the
 437 // instanceKlass.  These accessors pretend these fields are there.
 438 // The hprof specification also thinks these fields are in InstanceKlass.
 439 oop InstanceKlass::protection_domain() const {
 440   // return the protection_domain from the mirror
 441   return java_lang_Class::protection_domain(java_mirror());
 442 }
 443 
 444 // To remove these from requires an incompatible change and CCC request.
 445 objArrayOop InstanceKlass::signers() const {
 446   // return the signers from the mirror
 447   return java_lang_Class::signers(java_mirror());
 448 }
 449 
 450 oop InstanceKlass::init_lock() const {
 451   // return the init lock from the mirror
 452   oop lock = java_lang_Class::init_lock(java_mirror());
 453   // Prevent reordering with any access of initialization state
 454   OrderAccess::loadload();
 455   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
 456          "only fully initialized state can have a null lock");
 457   return lock;
 458 }
 459 
 460 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 461 // threads to get this lock will see a null lock and will not lock.
 462 // That's okay because they all check for initialized state after getting
 463 // the lock and return.
 464 void InstanceKlass::fence_and_clear_init_lock() {
 465   // make sure previous stores are all done, notably the init_state.
 466   OrderAccess::storestore();
 467   java_lang_Class::set_init_lock(java_mirror(), NULL);
 468   assert(!is_not_initialized(), "class must be initialized now");
 469 }
 470 
 471 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_k) {
 472   EXCEPTION_MARK;
 473   oop init_lock = this_k->init_lock();
 474   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 475 
 476   // abort if someone beat us to the initialization
 477   if (!this_k->is_not_initialized()) return;  // note: not equivalent to is_initialized()
 478 
 479   ClassState old_state = this_k->init_state();
 480   link_class_impl(this_k, true, THREAD);
 481   if (HAS_PENDING_EXCEPTION) {
 482     CLEAR_PENDING_EXCEPTION;
 483     // Abort if linking the class throws an exception.
 484 
 485     // Use a test to avoid redundantly resetting the state if there's
 486     // no change.  Set_init_state() asserts that state changes make
 487     // progress, whereas here we might just be spinning in place.
 488     if( old_state != this_k->_init_state )
 489       this_k->set_init_state (old_state);
 490   } else {
 491     // linking successfull, mark class as initialized
 492     this_k->set_init_state (fully_initialized);
 493     this_k->fence_and_clear_init_lock();
 494     // trace
 495     if (TraceClassInitialization) {
 496       ResourceMark rm(THREAD);
 497       tty->print_cr("[Initialized %s without side effects]", this_k->external_name());
 498     }
 499   }
 500 }
 501 
 502 
 503 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 504 // process. The step comments refers to the procedure described in that section.
 505 // Note: implementation moved to static method to expose the this pointer.
 506 void InstanceKlass::initialize(TRAPS) {
 507   if (this->should_be_initialized()) {
 508     HandleMark hm(THREAD);
 509     instanceKlassHandle this_k(THREAD, this);
 510     initialize_impl(this_k, CHECK);
 511     // Note: at this point the class may be initialized
 512     //       OR it may be in the state of being initialized
 513     //       in case of recursive initialization!
 514   } else {
 515     assert(is_initialized(), "sanity check");
 516   }
 517 }
 518 
 519 
 520 bool InstanceKlass::verify_code(
 521     instanceKlassHandle this_k, bool throw_verifyerror, TRAPS) {
 522   // 1) Verify the bytecodes
 523   Verifier::Mode mode =
 524     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
 525   return Verifier::verify(this_k, mode, this_k->should_verify_class(), THREAD);
 526 }
 527 
 528 
 529 // Used exclusively by the shared spaces dump mechanism to prevent
 530 // classes mapped into the shared regions in new VMs from appearing linked.
 531 
 532 void InstanceKlass::unlink_class() {
 533   assert(is_linked(), "must be linked");
 534   _init_state = loaded;
 535 }
 536 
 537 void InstanceKlass::link_class(TRAPS) {
 538   assert(is_loaded(), "must be loaded");
 539   if (!is_linked()) {
 540     HandleMark hm(THREAD);
 541     instanceKlassHandle this_k(THREAD, this);
 542     link_class_impl(this_k, true, CHECK);
 543   }
 544 }
 545 
 546 // Called to verify that a class can link during initialization, without
 547 // throwing a VerifyError.
 548 bool InstanceKlass::link_class_or_fail(TRAPS) {
 549   assert(is_loaded(), "must be loaded");
 550   if (!is_linked()) {
 551     HandleMark hm(THREAD);
 552     instanceKlassHandle this_k(THREAD, this);
 553     link_class_impl(this_k, false, CHECK_false);
 554   }
 555   return is_linked();
 556 }
 557 
 558 bool InstanceKlass::link_class_impl(
 559     instanceKlassHandle this_k, bool throw_verifyerror, TRAPS) {
 560   // check for error state
 561   if (this_k->is_in_error_state()) {
 562     ResourceMark rm(THREAD);
 563     THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
 564                this_k->external_name(), false);
 565   }
 566   // return if already verified
 567   if (this_k->is_linked()) {
 568     return true;
 569   }
 570 
 571   // Timing
 572   // timer handles recursion
 573   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 574   JavaThread* jt = (JavaThread*)THREAD;
 575 
 576   // link super class before linking this class
 577   instanceKlassHandle super(THREAD, this_k->super());
 578   if (super.not_null()) {
 579     if (super->is_interface()) {  // check if super class is an interface
 580       ResourceMark rm(THREAD);
 581       Exceptions::fthrow(
 582         THREAD_AND_LOCATION,
 583         vmSymbols::java_lang_IncompatibleClassChangeError(),
 584         "class %s has interface %s as super class",
 585         this_k->external_name(),
 586         super->external_name()
 587       );
 588       return false;
 589     }
 590 
 591     link_class_impl(super, throw_verifyerror, CHECK_false);
 592   }
 593 
 594   // link all interfaces implemented by this class before linking this class
 595   Array<Klass*>* interfaces = this_k->local_interfaces();
 596   int num_interfaces = interfaces->length();
 597   for (int index = 0; index < num_interfaces; index++) {
 598     HandleMark hm(THREAD);
 599     instanceKlassHandle ih(THREAD, interfaces->at(index));
 600     link_class_impl(ih, throw_verifyerror, CHECK_false);
 601   }
 602 
 603   // in case the class is linked in the process of linking its superclasses
 604   if (this_k->is_linked()) {
 605     return true;
 606   }
 607 
 608   // trace only the link time for this klass that includes
 609   // the verification time
 610   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 611                              ClassLoader::perf_class_link_selftime(),
 612                              ClassLoader::perf_classes_linked(),
 613                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 614                              jt->get_thread_stat()->perf_timers_addr(),
 615                              PerfClassTraceTime::CLASS_LINK);
 616 
 617   // verification & rewriting
 618   {
 619     oop init_lock = this_k->init_lock();
 620     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 621     // rewritten will have been set if loader constraint error found
 622     // on an earlier link attempt
 623     // don't verify or rewrite if already rewritten
 624 
 625     if (!this_k->is_linked()) {
 626       if (!this_k->is_rewritten()) {
 627         {
 628           bool verify_ok = verify_code(this_k, throw_verifyerror, THREAD);
 629           if (!verify_ok) {
 630             return false;
 631           }
 632         }
 633 
 634         // Just in case a side-effect of verify linked this class already
 635         // (which can sometimes happen since the verifier loads classes
 636         // using custom class loaders, which are free to initialize things)
 637         if (this_k->is_linked()) {
 638           return true;
 639         }
 640 
 641         // also sets rewritten
 642         this_k->rewrite_class(CHECK_false);
 643       }
 644 
 645       // relocate jsrs and link methods after they are all rewritten
 646       this_k->link_methods(CHECK_false);
 647 
 648       // Initialize the vtable and interface table after
 649       // methods have been rewritten since rewrite may
 650       // fabricate new Method*s.
 651       // also does loader constraint checking
 652       if (!this_k()->is_shared()) {
 653         ResourceMark rm(THREAD);
 654         this_k->vtable()->initialize_vtable(true, CHECK_false);
 655         this_k->itable()->initialize_itable(true, CHECK_false);
 656       }
 657 #ifdef ASSERT
 658       else {
 659         ResourceMark rm(THREAD);
 660         this_k->vtable()->verify(tty, true);
 661         // In case itable verification is ever added.
 662         // this_k->itable()->verify(tty, true);
 663       }
 664 #endif
 665       this_k->set_init_state(linked);
 666       if (JvmtiExport::should_post_class_prepare()) {
 667         Thread *thread = THREAD;
 668         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 669         JvmtiExport::post_class_prepare((JavaThread *) thread, this_k());
 670       }
 671     }
 672   }
 673   return true;
 674 }
 675 
 676 
 677 // Rewrite the byte codes of all of the methods of a class.
 678 // The rewriter must be called exactly once. Rewriting must happen after
 679 // verification but before the first method of the class is executed.
 680 void InstanceKlass::rewrite_class(TRAPS) {
 681   assert(is_loaded(), "must be loaded");
 682   instanceKlassHandle this_k(THREAD, this);
 683   if (this_k->is_rewritten()) {
 684     assert(this_k()->is_shared(), "rewriting an unshared class?");
 685     return;
 686   }
 687   Rewriter::rewrite(this_k, CHECK);
 688   this_k->set_rewritten();
 689 }
 690 
 691 // Now relocate and link method entry points after class is rewritten.
 692 // This is outside is_rewritten flag. In case of an exception, it can be
 693 // executed more than once.
 694 void InstanceKlass::link_methods(TRAPS) {
 695   int len = methods()->length();
 696   for (int i = len-1; i >= 0; i--) {
 697     methodHandle m(THREAD, methods()->at(i));
 698 
 699     // Set up method entry points for compiler and interpreter    .
 700     m->link_method(m, CHECK);
 701   }
 702 }
 703 
 704 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
 705 void InstanceKlass::initialize_super_interfaces(instanceKlassHandle this_k, TRAPS) {
 706   if (this_k->has_default_methods()) {
 707     for (int i = 0; i < this_k->local_interfaces()->length(); ++i) {
 708       Klass* iface = this_k->local_interfaces()->at(i);
 709       InstanceKlass* ik = InstanceKlass::cast(iface);
 710       if (ik->should_be_initialized()) {
 711         if (ik->has_default_methods()) {
 712           ik->initialize_super_interfaces(ik, THREAD);
 713         }
 714         // Only initialize() interfaces that "declare" concrete methods.
 715         // has_default_methods drives searching superinterfaces since it
 716         // means has_default_methods in its superinterface hierarchy
 717         if (!HAS_PENDING_EXCEPTION && ik->declares_default_methods()) {
 718           ik->initialize(THREAD);
 719         }
 720         if (HAS_PENDING_EXCEPTION) {
 721           Handle e(THREAD, PENDING_EXCEPTION);
 722           CLEAR_PENDING_EXCEPTION;
 723           {
 724             EXCEPTION_MARK;
 725             // Locks object, set state, and notify all waiting threads
 726             this_k->set_initialization_state_and_notify(
 727                 initialization_error, THREAD);
 728 
 729             // ignore any exception thrown, superclass initialization error is
 730             // thrown below
 731             CLEAR_PENDING_EXCEPTION;
 732           }
 733           THROW_OOP(e());
 734         }
 735       }
 736     }
 737   }
 738 }
 739 
 740 void InstanceKlass::initialize_impl(instanceKlassHandle this_k, TRAPS) {
 741   // Make sure klass is linked (verified) before initialization
 742   // A class could already be verified, since it has been reflected upon.
 743   this_k->link_class(CHECK);
 744 
 745   DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_k()), -1);
 746 
 747   bool wait = false;
 748 
 749   // refer to the JVM book page 47 for description of steps
 750   // Step 1
 751   {
 752     oop init_lock = this_k->init_lock();
 753     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 754 
 755     Thread *self = THREAD; // it's passed the current thread
 756 
 757     // Step 2
 758     // If we were to use wait() instead of waitInterruptibly() then
 759     // we might end up throwing IE from link/symbol resolution sites
 760     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
 761     while(this_k->is_being_initialized() && !this_k->is_reentrant_initialization(self)) {
 762         wait = true;
 763       ol.waitUninterruptibly(CHECK);
 764     }
 765 
 766     // Step 3
 767     if (this_k->is_being_initialized() && this_k->is_reentrant_initialization(self)) {
 768       DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_k()), -1,wait);
 769       return;
 770     }
 771 
 772     // Step 4
 773     if (this_k->is_initialized()) {
 774       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_k()), -1,wait);
 775       return;
 776     }
 777 
 778     // Step 5
 779     if (this_k->is_in_error_state()) {
 780       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_k()), -1,wait);
 781       ResourceMark rm(THREAD);
 782       const char* desc = "Could not initialize class ";
 783       const char* className = this_k->external_name();
 784       size_t msglen = strlen(desc) + strlen(className) + 1;
 785       char* message = NEW_RESOURCE_ARRAY(char, msglen);
 786       if (NULL == message) {
 787         // Out of memory: can't create detailed error message
 788         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
 789       } else {
 790         jio_snprintf(message, msglen, "%s%s", desc, className);
 791         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
 792       }
 793     }
 794 
 795     // Step 6
 796     this_k->set_init_state(being_initialized);
 797     this_k->set_init_thread(self);
 798   }
 799 
 800   // Step 7
 801   Klass* super_klass = this_k->super();
 802   if (super_klass != NULL && !this_k->is_interface() && super_klass->should_be_initialized()) {
 803     super_klass->initialize(THREAD);
 804 
 805     if (HAS_PENDING_EXCEPTION) {
 806       Handle e(THREAD, PENDING_EXCEPTION);
 807       CLEAR_PENDING_EXCEPTION;
 808       {
 809         EXCEPTION_MARK;
 810         this_k->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
 811         CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, superclass initialization error is thrown below
 812       }
 813       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_k()), -1,wait);
 814       THROW_OOP(e());
 815     }
 816   }
 817 
 818   // Recursively initialize any superinterfaces that declare default methods
 819   // Only need to recurse if has_default_methods which includes declaring and
 820   // inheriting default methods
 821   if (this_k->has_default_methods()) {
 822     this_k->initialize_super_interfaces(this_k, CHECK);
 823   }
 824 
 825   // Step 8
 826   {
 827     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
 828     JavaThread* jt = (JavaThread*)THREAD;
 829     DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_k()), -1,wait);
 830     // Timer includes any side effects of class initialization (resolution,
 831     // etc), but not recursive entry into call_class_initializer().
 832     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
 833                              ClassLoader::perf_class_init_selftime(),
 834                              ClassLoader::perf_classes_inited(),
 835                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 836                              jt->get_thread_stat()->perf_timers_addr(),
 837                              PerfClassTraceTime::CLASS_CLINIT);
 838     this_k->call_class_initializer(THREAD);
 839   }
 840 
 841   // Step 9
 842   if (!HAS_PENDING_EXCEPTION) {
 843     this_k->set_initialization_state_and_notify(fully_initialized, CHECK);
 844     { ResourceMark rm(THREAD);
 845       debug_only(this_k->vtable()->verify(tty, true);)
 846     }
 847   }
 848   else {
 849     // Step 10 and 11
 850     Handle e(THREAD, PENDING_EXCEPTION);
 851     CLEAR_PENDING_EXCEPTION;
 852     // JVMTI has already reported the pending exception
 853     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 854     JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 855     {
 856       EXCEPTION_MARK;
 857       this_k->set_initialization_state_and_notify(initialization_error, THREAD);
 858       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
 859       // JVMTI has already reported the pending exception
 860       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 861       JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 862     }
 863     DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_k()), -1,wait);
 864     if (e->is_a(SystemDictionary::Error_klass())) {
 865       THROW_OOP(e());
 866     } else {
 867       JavaCallArguments args(e);
 868       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
 869                 vmSymbols::throwable_void_signature(),
 870                 &args);
 871     }
 872   }
 873   DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_k()), -1,wait);
 874 }
 875 
 876 
 877 // Note: implementation moved to static method to expose the this pointer.
 878 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
 879   instanceKlassHandle kh(THREAD, this);
 880   set_initialization_state_and_notify_impl(kh, state, CHECK);
 881 }
 882 
 883 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_k, ClassState state, TRAPS) {
 884   oop init_lock = this_k->init_lock();
 885   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
 886   this_k->set_init_state(state);
 887   this_k->fence_and_clear_init_lock();
 888   ol.notify_all(CHECK);
 889 }
 890 
 891 // The embedded _implementor field can only record one implementor.
 892 // When there are more than one implementors, the _implementor field
 893 // is set to the interface Klass* itself. Following are the possible
 894 // values for the _implementor field:
 895 //   NULL                  - no implementor
 896 //   implementor Klass*    - one implementor
 897 //   self                  - more than one implementor
 898 //
 899 // The _implementor field only exists for interfaces.
 900 void InstanceKlass::add_implementor(Klass* k) {
 901   assert(Compile_lock->owned_by_self(), "");
 902   assert(is_interface(), "not interface");
 903   // Filter out my subinterfaces.
 904   // (Note: Interfaces are never on the subklass list.)
 905   if (InstanceKlass::cast(k)->is_interface()) return;
 906 
 907   // Filter out subclasses whose supers already implement me.
 908   // (Note: CHA must walk subclasses of direct implementors
 909   // in order to locate indirect implementors.)
 910   Klass* sk = InstanceKlass::cast(k)->super();
 911   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
 912     // We only need to check one immediate superclass, since the
 913     // implements_interface query looks at transitive_interfaces.
 914     // Any supers of the super have the same (or fewer) transitive_interfaces.
 915     return;
 916 
 917   Klass* ik = implementor();
 918   if (ik == NULL) {
 919     set_implementor(k);
 920   } else if (ik != this) {
 921     // There is already an implementor. Use itself as an indicator of
 922     // more than one implementors.
 923     set_implementor(this);
 924   }
 925 
 926   // The implementor also implements the transitive_interfaces
 927   for (int index = 0; index < local_interfaces()->length(); index++) {
 928     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
 929   }
 930 }
 931 
 932 void InstanceKlass::init_implementor() {
 933   if (is_interface()) {
 934     set_implementor(NULL);
 935   }
 936 }
 937 
 938 
 939 void InstanceKlass::process_interfaces(Thread *thread) {
 940   // link this class into the implementors list of every interface it implements
 941   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
 942     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
 943     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
 944     assert(interf->is_interface(), "expected interface");
 945     interf->add_implementor(this);
 946   }
 947 }
 948 
 949 bool InstanceKlass::can_be_primary_super_slow() const {
 950   if (is_interface())
 951     return false;
 952   else
 953     return Klass::can_be_primary_super_slow();
 954 }
 955 
 956 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
 957   // The secondaries are the implemented interfaces.
 958   InstanceKlass* ik = InstanceKlass::cast(this);
 959   Array<Klass*>* interfaces = ik->transitive_interfaces();
 960   int num_secondaries = num_extra_slots + interfaces->length();
 961   if (num_secondaries == 0) {
 962     // Must share this for correct bootstrapping!
 963     set_secondary_supers(Universe::the_empty_klass_array());
 964     return NULL;
 965   } else if (num_extra_slots == 0) {
 966     // The secondary super list is exactly the same as the transitive interfaces.
 967     // Redefine classes has to be careful not to delete this!
 968     set_secondary_supers(interfaces);
 969     return NULL;
 970   } else {
 971     // Copy transitive interfaces to a temporary growable array to be constructed
 972     // into the secondary super list with extra slots.
 973     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
 974     for (int i = 0; i < interfaces->length(); i++) {
 975       secondaries->push(interfaces->at(i));
 976     }
 977     return secondaries;
 978   }
 979 }
 980 
 981 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
 982   if (k->is_interface()) {
 983     return implements_interface(k);
 984   } else {
 985     return Klass::compute_is_subtype_of(k);
 986   }
 987 }
 988 
 989 bool InstanceKlass::implements_interface(Klass* k) const {
 990   if (this == k) return true;
 991   assert(k->is_interface(), "should be an interface class");
 992   for (int i = 0; i < transitive_interfaces()->length(); i++) {
 993     if (transitive_interfaces()->at(i) == k) {
 994       return true;
 995     }
 996   }
 997   return false;
 998 }
 999 
1000 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1001   // Verify direct super interface
1002   if (this == k) return true;
1003   assert(k->is_interface(), "should be an interface class");
1004   for (int i = 0; i < local_interfaces()->length(); i++) {
1005     if (local_interfaces()->at(i) == k) {
1006       return true;
1007     }
1008   }
1009   return false;
1010 }
1011 
1012 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1013   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
1014   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
1015     report_java_out_of_memory("Requested array size exceeds VM limit");
1016     JvmtiExport::post_array_size_exhausted();
1017     THROW_OOP_0(Universe::out_of_memory_error_array_size());
1018   }
1019   int size = objArrayOopDesc::object_size(length);
1020   Klass* ak = array_klass(n, CHECK_NULL);
1021   KlassHandle h_ak (THREAD, ak);
1022   objArrayOop o =
1023     (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
1024   return o;
1025 }
1026 
1027 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1028   if (TraceFinalizerRegistration) {
1029     tty->print("Registered ");
1030     i->print_value_on(tty);
1031     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
1032   }
1033   instanceHandle h_i(THREAD, i);
1034   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1035   JavaValue result(T_VOID);
1036   JavaCallArguments args(h_i);
1037   methodHandle mh (THREAD, Universe::finalizer_register_method());
1038   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1039   return h_i();
1040 }
1041 
1042 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1043   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1044   int size = size_helper();  // Query before forming handle.
1045 
1046   KlassHandle h_k(THREAD, this);
1047 
1048   instanceOop i;
1049 
1050   i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
1051   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1052     i = register_finalizer(i, CHECK_NULL);
1053   }
1054   return i;
1055 }
1056 
1057 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1058   if (is_interface() || is_abstract()) {
1059     ResourceMark rm(THREAD);
1060     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1061               : vmSymbols::java_lang_InstantiationException(), external_name());
1062   }
1063   if (this == SystemDictionary::Class_klass()) {
1064     ResourceMark rm(THREAD);
1065     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1066               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1067   }
1068 }
1069 
1070 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1071   instanceKlassHandle this_k(THREAD, this);
1072   return array_klass_impl(this_k, or_null, n, THREAD);
1073 }
1074 
1075 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_k, bool or_null, int n, TRAPS) {
1076   if (this_k->array_klasses() == NULL) {
1077     if (or_null) return NULL;
1078 
1079     ResourceMark rm;
1080     JavaThread *jt = (JavaThread *)THREAD;
1081     {
1082       // Atomic creation of array_klasses
1083       MutexLocker mc(Compile_lock, THREAD);   // for vtables
1084       MutexLocker ma(MultiArray_lock, THREAD);
1085 
1086       // Check if update has already taken place
1087       if (this_k->array_klasses() == NULL) {
1088         Klass*    k = ObjArrayKlass::allocate_objArray_klass(this_k->class_loader_data(), 1, this_k, CHECK_NULL);
1089         this_k->set_array_klasses(k);
1090       }
1091     }
1092   }
1093   // _this will always be set at this point
1094   ObjArrayKlass* oak = (ObjArrayKlass*)this_k->array_klasses();
1095   if (or_null) {
1096     return oak->array_klass_or_null(n);
1097   }
1098   return oak->array_klass(n, THREAD);
1099 }
1100 
1101 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1102   return array_klass_impl(or_null, 1, THREAD);
1103 }
1104 
1105 void InstanceKlass::call_class_initializer(TRAPS) {
1106   instanceKlassHandle ik (THREAD, this);
1107   call_class_initializer_impl(ik, THREAD);
1108 }
1109 
1110 static int call_class_initializer_impl_counter = 0;   // for debugging
1111 
1112 Method* InstanceKlass::class_initializer() {
1113   Method* clinit = find_method(
1114       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1115   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1116     return clinit;
1117   }
1118   return NULL;
1119 }
1120 
1121 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_k, TRAPS) {
1122   if (ReplayCompiles &&
1123       (ReplaySuppressInitializers == 1 ||
1124        ReplaySuppressInitializers >= 2 && this_k->class_loader() != NULL)) {
1125     // Hide the existence of the initializer for the purpose of replaying the compile
1126     return;
1127   }
1128 
1129   methodHandle h_method(THREAD, this_k->class_initializer());
1130   assert(!this_k->is_initialized(), "we cannot initialize twice");
1131   if (TraceClassInitialization) {
1132     tty->print("%d Initializing ", call_class_initializer_impl_counter++);
1133     this_k->name()->print_value();
1134     tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_k());
1135   }
1136   if (h_method() != NULL) {
1137     JavaCallArguments args; // No arguments
1138     JavaValue result(T_VOID);
1139     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1140   }
1141 }
1142 
1143 
1144 void InstanceKlass::mask_for(methodHandle method, int bci,
1145   InterpreterOopMap* entry_for) {
1146   // Dirty read, then double-check under a lock.
1147   if (_oop_map_cache == NULL) {
1148     // Otherwise, allocate a new one.
1149     MutexLocker x(OopMapCacheAlloc_lock);
1150     // First time use. Allocate a cache in C heap
1151     if (_oop_map_cache == NULL) {
1152       // Release stores from OopMapCache constructor before assignment
1153       // to _oop_map_cache. C++ compilers on ppc do not emit the
1154       // required memory barrier only because of the volatile
1155       // qualifier of _oop_map_cache.
1156       OrderAccess::release_store_ptr(&_oop_map_cache, new OopMapCache());
1157     }
1158   }
1159   // _oop_map_cache is constant after init; lookup below does is own locking.
1160   _oop_map_cache->lookup(method, bci, entry_for);
1161 }
1162 
1163 
1164 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1165   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1166     Symbol* f_name = fs.name();
1167     Symbol* f_sig  = fs.signature();
1168     if (f_name == name && f_sig == sig) {
1169       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1170       return true;
1171     }
1172   }
1173   return false;
1174 }
1175 
1176 
1177 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1178   const int n = local_interfaces()->length();
1179   for (int i = 0; i < n; i++) {
1180     Klass* intf1 = local_interfaces()->at(i);
1181     assert(intf1->is_interface(), "just checking type");
1182     // search for field in current interface
1183     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1184       assert(fd->is_static(), "interface field must be static");
1185       return intf1;
1186     }
1187     // search for field in direct superinterfaces
1188     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1189     if (intf2 != NULL) return intf2;
1190   }
1191   // otherwise field lookup fails
1192   return NULL;
1193 }
1194 
1195 
1196 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1197   // search order according to newest JVM spec (5.4.3.2, p.167).
1198   // 1) search for field in current klass
1199   if (find_local_field(name, sig, fd)) {
1200     return const_cast<InstanceKlass*>(this);
1201   }
1202   // 2) search for field recursively in direct superinterfaces
1203   { Klass* intf = find_interface_field(name, sig, fd);
1204     if (intf != NULL) return intf;
1205   }
1206   // 3) apply field lookup recursively if superclass exists
1207   { Klass* supr = super();
1208     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1209   }
1210   // 4) otherwise field lookup fails
1211   return NULL;
1212 }
1213 
1214 
1215 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1216   // search order according to newest JVM spec (5.4.3.2, p.167).
1217   // 1) search for field in current klass
1218   if (find_local_field(name, sig, fd)) {
1219     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1220   }
1221   // 2) search for field recursively in direct superinterfaces
1222   if (is_static) {
1223     Klass* intf = find_interface_field(name, sig, fd);
1224     if (intf != NULL) return intf;
1225   }
1226   // 3) apply field lookup recursively if superclass exists
1227   { Klass* supr = super();
1228     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1229   }
1230   // 4) otherwise field lookup fails
1231   return NULL;
1232 }
1233 
1234 
1235 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1236   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1237     if (fs.offset() == offset) {
1238       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1239       if (fd->is_static() == is_static) return true;
1240     }
1241   }
1242   return false;
1243 }
1244 
1245 
1246 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1247   Klass* klass = const_cast<InstanceKlass*>(this);
1248   while (klass != NULL) {
1249     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1250       return true;
1251     }
1252     klass = klass->super();
1253   }
1254   return false;
1255 }
1256 
1257 
1258 void InstanceKlass::methods_do(void f(Method* method)) {
1259   // Methods aren't stable until they are loaded.  This can be read outside
1260   // a lock through the ClassLoaderData for profiling
1261   if (!is_loaded()) {
1262     return;
1263   }
1264 
1265   int len = methods()->length();
1266   for (int index = 0; index < len; index++) {
1267     Method* m = methods()->at(index);
1268     assert(m->is_method(), "must be method");
1269     f(m);
1270   }
1271 }
1272 
1273 
1274 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1275   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1276     if (fs.access_flags().is_static()) {
1277       fieldDescriptor& fd = fs.field_descriptor();
1278       cl->do_field(&fd);
1279     }
1280   }
1281 }
1282 
1283 
1284 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1285   instanceKlassHandle h_this(THREAD, this);
1286   do_local_static_fields_impl(h_this, f, mirror, CHECK);
1287 }
1288 
1289 
1290 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_k,
1291                              void f(fieldDescriptor* fd, Handle, TRAPS), Handle mirror, TRAPS) {
1292   for (JavaFieldStream fs(this_k()); !fs.done(); fs.next()) {
1293     if (fs.access_flags().is_static()) {
1294       fieldDescriptor& fd = fs.field_descriptor();
1295       f(&fd, mirror, CHECK);
1296     }
1297   }
1298 }
1299 
1300 
1301 static int compare_fields_by_offset(int* a, int* b) {
1302   return a[0] - b[0];
1303 }
1304 
1305 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1306   InstanceKlass* super = superklass();
1307   if (super != NULL) {
1308     super->do_nonstatic_fields(cl);
1309   }
1310   fieldDescriptor fd;
1311   int length = java_fields_count();
1312   // In DebugInfo nonstatic fields are sorted by offset.
1313   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1314   int j = 0;
1315   for (int i = 0; i < length; i += 1) {
1316     fd.reinitialize(this, i);
1317     if (!fd.is_static()) {
1318       fields_sorted[j + 0] = fd.offset();
1319       fields_sorted[j + 1] = i;
1320       j += 2;
1321     }
1322   }
1323   if (j > 0) {
1324     length = j;
1325     // _sort_Fn is defined in growableArray.hpp.
1326     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1327     for (int i = 0; i < length; i += 2) {
1328       fd.reinitialize(this, fields_sorted[i + 1]);
1329       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1330       cl->do_field(&fd);
1331     }
1332   }
1333   FREE_C_HEAP_ARRAY(int, fields_sorted);
1334 }
1335 
1336 
1337 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1338   if (array_klasses() != NULL)
1339     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1340 }
1341 
1342 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1343   if (array_klasses() != NULL)
1344     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1345 }
1346 
1347 #ifdef ASSERT
1348 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
1349   int len = methods->length();
1350   for (int index = 0; index < len; index++) {
1351     Method* m = methods->at(index);
1352     assert(m->is_method(), "must be method");
1353     if (m->signature() == signature && m->name() == name) {
1354        return index;
1355     }
1356   }
1357   return -1;
1358 }
1359 #endif
1360 
1361 static int binary_search(Array<Method*>* methods, Symbol* name) {
1362   int len = methods->length();
1363   // methods are sorted, so do binary search
1364   int l = 0;
1365   int h = len - 1;
1366   while (l <= h) {
1367     int mid = (l + h) >> 1;
1368     Method* m = methods->at(mid);
1369     assert(m->is_method(), "must be method");
1370     int res = m->name()->fast_compare(name);
1371     if (res == 0) {
1372       return mid;
1373     } else if (res < 0) {
1374       l = mid + 1;
1375     } else {
1376       h = mid - 1;
1377     }
1378   }
1379   return -1;
1380 }
1381 
1382 // find_method looks up the name/signature in the local methods array
1383 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
1384   return find_method_impl(name, signature, find_overpass, find_static, find_private);
1385 }
1386 
1387 Method* InstanceKlass::find_method_impl(Symbol* name, Symbol* signature,
1388                                         OverpassLookupMode overpass_mode,
1389                                         StaticLookupMode static_mode,
1390                                         PrivateLookupMode private_mode) const {
1391   return InstanceKlass::find_method_impl(methods(), name, signature, overpass_mode, static_mode, private_mode);
1392 }
1393 
1394 // find_instance_method looks up the name/signature in the local methods array
1395 // and skips over static methods
1396 Method* InstanceKlass::find_instance_method(
1397     Array<Method*>* methods, Symbol* name, Symbol* signature) {
1398   Method* meth = InstanceKlass::find_method_impl(methods, name, signature,
1399                                                  find_overpass, skip_static, find_private);
1400   assert(((meth == NULL) || !meth->is_static()), "find_instance_method should have skipped statics");
1401   return meth;
1402 }
1403 
1404 // find_instance_method looks up the name/signature in the local methods array
1405 // and skips over static methods
1406 Method* InstanceKlass::find_instance_method(Symbol* name, Symbol* signature) {
1407     return InstanceKlass::find_instance_method(methods(), name, signature);
1408 }
1409 
1410 // Find looks up the name/signature in the local methods array
1411 // and filters on the overpass, static and private flags
1412 // This returns the first one found
1413 // note that the local methods array can have up to one overpass, one static
1414 // and one instance (private or not) with the same name/signature
1415 Method* InstanceKlass::find_local_method(Symbol* name, Symbol* signature,
1416                                         OverpassLookupMode overpass_mode,
1417                                         StaticLookupMode static_mode,
1418                                         PrivateLookupMode private_mode) const {
1419   return InstanceKlass::find_method_impl(methods(), name, signature, overpass_mode, static_mode, private_mode);
1420 }
1421 
1422 // Find looks up the name/signature in the local methods array
1423 // and filters on the overpass, static and private flags
1424 // This returns the first one found
1425 // note that the local methods array can have up to one overpass, one static
1426 // and one instance (private or not) with the same name/signature
1427 Method* InstanceKlass::find_local_method(Array<Method*>* methods,
1428                                         Symbol* name, Symbol* signature,
1429                                         OverpassLookupMode overpass_mode,
1430                                         StaticLookupMode static_mode,
1431                                         PrivateLookupMode private_mode) {
1432   return InstanceKlass::find_method_impl(methods, name, signature, overpass_mode, static_mode, private_mode);
1433 }
1434 
1435 
1436 // find_method looks up the name/signature in the local methods array
1437 Method* InstanceKlass::find_method(
1438     Array<Method*>* methods, Symbol* name, Symbol* signature) {
1439   return InstanceKlass::find_method_impl(methods, name, signature, find_overpass, find_static, find_private);
1440 }
1441 
1442 Method* InstanceKlass::find_method_impl(
1443     Array<Method*>* methods, Symbol* name, Symbol* signature,
1444     OverpassLookupMode overpass_mode, StaticLookupMode static_mode,
1445     PrivateLookupMode private_mode) {
1446   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1447   return hit >= 0 ? methods->at(hit): NULL;
1448 }
1449 
1450 bool InstanceKlass::method_matches(Method* m, Symbol* signature, bool skipping_overpass, bool skipping_static, bool skipping_private) {
1451     return  ((m->signature() == signature) &&
1452             (!skipping_overpass || !m->is_overpass()) &&
1453             (!skipping_static || !m->is_static()) &&
1454             (!skipping_private || !m->is_private()));
1455 }
1456 
1457 // Used directly for default_methods to find the index into the
1458 // default_vtable_indices, and indirectly by find_method
1459 // find_method_index looks in the local methods array to return the index
1460 // of the matching name/signature. If, overpass methods are being ignored,
1461 // the search continues to find a potential non-overpass match.  This capability
1462 // is important during method resolution to prefer a static method, for example,
1463 // over an overpass method.
1464 // There is the possibility in any _method's array to have the same name/signature
1465 // for a static method, an overpass method and a local instance method
1466 // To correctly catch a given method, the search criteria may need
1467 // to explicitly skip the other two. For local instance methods, it
1468 // is often necessary to skip private methods
1469 int InstanceKlass::find_method_index(
1470     Array<Method*>* methods, Symbol* name, Symbol* signature,
1471     OverpassLookupMode overpass_mode, StaticLookupMode static_mode,
1472     PrivateLookupMode private_mode) {
1473   bool skipping_overpass = (overpass_mode == skip_overpass);
1474   bool skipping_static = (static_mode == skip_static);
1475   bool skipping_private = (private_mode == skip_private);
1476   int hit = binary_search(methods, name);
1477   if (hit != -1) {
1478     Method* m = methods->at(hit);
1479 
1480     // Do linear search to find matching signature.  First, quick check
1481     // for common case, ignoring overpasses if requested.
1482     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) return hit;
1483 
1484     // search downwards through overloaded methods
1485     int i;
1486     for (i = hit - 1; i >= 0; --i) {
1487         Method* m = methods->at(i);
1488         assert(m->is_method(), "must be method");
1489         if (m->name() != name) break;
1490         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) return i;
1491     }
1492     // search upwards
1493     for (i = hit + 1; i < methods->length(); ++i) {
1494         Method* m = methods->at(i);
1495         assert(m->is_method(), "must be method");
1496         if (m->name() != name) break;
1497         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) return i;
1498     }
1499     // not found
1500 #ifdef ASSERT
1501     int index = (skipping_overpass || skipping_static || skipping_private) ? -1 : linear_search(methods, name, signature);
1502     assert(index == -1, err_msg("binary search should have found entry %d", index));
1503 #endif
1504   }
1505   return -1;
1506 }
1507 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
1508   return find_method_by_name(methods(), name, end);
1509 }
1510 
1511 int InstanceKlass::find_method_by_name(
1512     Array<Method*>* methods, Symbol* name, int* end_ptr) {
1513   assert(end_ptr != NULL, "just checking");
1514   int start = binary_search(methods, name);
1515   int end = start + 1;
1516   if (start != -1) {
1517     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1518     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1519     *end_ptr = end;
1520     return start;
1521   }
1522   return -1;
1523 }
1524 
1525 // uncached_lookup_method searches both the local class methods array and all
1526 // superclasses methods arrays, skipping any overpass methods in superclasses.
1527 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature, OverpassLookupMode overpass_mode) const {
1528   OverpassLookupMode overpass_local_mode = overpass_mode;
1529   Klass* klass = const_cast<InstanceKlass*>(this);
1530   while (klass != NULL) {
1531     Method* method = InstanceKlass::cast(klass)->find_method_impl(name, signature, overpass_local_mode, find_static, find_private);
1532     if (method != NULL) {
1533       return method;
1534     }
1535     klass = InstanceKlass::cast(klass)->super();
1536     overpass_local_mode = skip_overpass;   // Always ignore overpass methods in superclasses
1537   }
1538   return NULL;
1539 }
1540 
1541 #ifdef ASSERT
1542 // search through class hierarchy and return true if this class or
1543 // one of the superclasses was redefined
1544 bool InstanceKlass::has_redefined_this_or_super() const {
1545   const InstanceKlass* klass = this;
1546   while (klass != NULL) {
1547     if (klass->has_been_redefined()) {
1548       return true;
1549     }
1550     klass = InstanceKlass::cast(klass->super());
1551   }
1552   return false;
1553 }
1554 #endif
1555 
1556 // lookup a method in the default methods list then in all transitive interfaces
1557 // Do NOT return private or static methods
1558 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1559                                                          Symbol* signature) const {
1560   Method* m = NULL;
1561   if (default_methods() != NULL) {
1562     m = find_method(default_methods(), name, signature);
1563   }
1564   // Look up interfaces
1565   if (m == NULL) {
1566     m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1567   }
1568   return m;
1569 }
1570 
1571 // lookup a method in all the interfaces that this class implements
1572 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1573 // They should only be found in the initial InterfaceMethodRef
1574 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1575                                                        Symbol* signature,
1576                                                        DefaultsLookupMode defaults_mode) const {
1577   Array<Klass*>* all_ifs = transitive_interfaces();
1578   int num_ifs = all_ifs->length();
1579   InstanceKlass *ik = NULL;
1580   for (int i = 0; i < num_ifs; i++) {
1581     ik = InstanceKlass::cast(all_ifs->at(i));
1582     Method* m = ik->lookup_method(name, signature);
1583     if (m != NULL && m->is_public() && !m->is_static() &&
1584         ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1585       return m;
1586     }
1587   }
1588   return NULL;
1589 }
1590 
1591 /* jni_id_for_impl for jfieldIds only */
1592 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_k, int offset) {
1593   MutexLocker ml(JfieldIdCreation_lock);
1594   // Retry lookup after we got the lock
1595   JNIid* probe = this_k->jni_ids() == NULL ? NULL : this_k->jni_ids()->find(offset);
1596   if (probe == NULL) {
1597     // Slow case, allocate new static field identifier
1598     probe = new JNIid(this_k(), offset, this_k->jni_ids());
1599     this_k->set_jni_ids(probe);
1600   }
1601   return probe;
1602 }
1603 
1604 
1605 /* jni_id_for for jfieldIds only */
1606 JNIid* InstanceKlass::jni_id_for(int offset) {
1607   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1608   if (probe == NULL) {
1609     probe = jni_id_for_impl(this, offset);
1610   }
1611   return probe;
1612 }
1613 
1614 u2 InstanceKlass::enclosing_method_data(int offset) {
1615   Array<jushort>* inner_class_list = inner_classes();
1616   if (inner_class_list == NULL) {
1617     return 0;
1618   }
1619   int length = inner_class_list->length();
1620   if (length % inner_class_next_offset == 0) {
1621     return 0;
1622   } else {
1623     int index = length - enclosing_method_attribute_size;
1624     assert(offset < enclosing_method_attribute_size, "invalid offset");
1625     return inner_class_list->at(index + offset);
1626   }
1627 }
1628 
1629 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1630                                                  u2 method_index) {
1631   Array<jushort>* inner_class_list = inner_classes();
1632   assert (inner_class_list != NULL, "_inner_classes list is not set up");
1633   int length = inner_class_list->length();
1634   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1635     int index = length - enclosing_method_attribute_size;
1636     inner_class_list->at_put(
1637       index + enclosing_method_class_index_offset, class_index);
1638     inner_class_list->at_put(
1639       index + enclosing_method_method_index_offset, method_index);
1640   }
1641 }
1642 
1643 // Lookup or create a jmethodID.
1644 // This code is called by the VMThread and JavaThreads so the
1645 // locking has to be done very carefully to avoid deadlocks
1646 // and/or other cache consistency problems.
1647 //
1648 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1649   size_t idnum = (size_t)method_h->method_idnum();
1650   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1651   size_t length = 0;
1652   jmethodID id = NULL;
1653 
1654   // We use a double-check locking idiom here because this cache is
1655   // performance sensitive. In the normal system, this cache only
1656   // transitions from NULL to non-NULL which is safe because we use
1657   // release_set_methods_jmethod_ids() to advertise the new cache.
1658   // A partially constructed cache should never be seen by a racing
1659   // thread. We also use release_store_ptr() to save a new jmethodID
1660   // in the cache so a partially constructed jmethodID should never be
1661   // seen either. Cache reads of existing jmethodIDs proceed without a
1662   // lock, but cache writes of a new jmethodID requires uniqueness and
1663   // creation of the cache itself requires no leaks so a lock is
1664   // generally acquired in those two cases.
1665   //
1666   // If the RedefineClasses() API has been used, then this cache can
1667   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1668   // Cache creation requires no leaks and we require safety between all
1669   // cache accesses and freeing of the old cache so a lock is generally
1670   // acquired when the RedefineClasses() API has been used.
1671 
1672   if (jmeths != NULL) {
1673     // the cache already exists
1674     if (!ik_h->idnum_can_increment()) {
1675       // the cache can't grow so we can just get the current values
1676       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1677     } else {
1678       // cache can grow so we have to be more careful
1679       if (Threads::number_of_threads() == 0 ||
1680           SafepointSynchronize::is_at_safepoint()) {
1681         // we're single threaded or at a safepoint - no locking needed
1682         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1683       } else {
1684         MutexLocker ml(JmethodIdCreation_lock);
1685         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1686       }
1687     }
1688   }
1689   // implied else:
1690   // we need to allocate a cache so default length and id values are good
1691 
1692   if (jmeths == NULL ||   // no cache yet
1693       length <= idnum ||  // cache is too short
1694       id == NULL) {       // cache doesn't contain entry
1695 
1696     // This function can be called by the VMThread so we have to do all
1697     // things that might block on a safepoint before grabbing the lock.
1698     // Otherwise, we can deadlock with the VMThread or have a cache
1699     // consistency issue. These vars keep track of what we might have
1700     // to free after the lock is dropped.
1701     jmethodID  to_dealloc_id     = NULL;
1702     jmethodID* to_dealloc_jmeths = NULL;
1703 
1704     // may not allocate new_jmeths or use it if we allocate it
1705     jmethodID* new_jmeths = NULL;
1706     if (length <= idnum) {
1707       // allocate a new cache that might be used
1708       size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1709       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1710       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1711       // cache size is stored in element[0], other elements offset by one
1712       new_jmeths[0] = (jmethodID)size;
1713     }
1714 
1715     // allocate a new jmethodID that might be used
1716     jmethodID new_id = NULL;
1717     if (method_h->is_old() && !method_h->is_obsolete()) {
1718       // The method passed in is old (but not obsolete), we need to use the current version
1719       Method* current_method = ik_h->method_with_idnum((int)idnum);
1720       assert(current_method != NULL, "old and but not obsolete, so should exist");
1721       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
1722     } else {
1723       // It is the current version of the method or an obsolete method,
1724       // use the version passed in
1725       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
1726     }
1727 
1728     if (Threads::number_of_threads() == 0 ||
1729         SafepointSynchronize::is_at_safepoint()) {
1730       // we're single threaded or at a safepoint - no locking needed
1731       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1732                                           &to_dealloc_id, &to_dealloc_jmeths);
1733     } else {
1734       MutexLocker ml(JmethodIdCreation_lock);
1735       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1736                                           &to_dealloc_id, &to_dealloc_jmeths);
1737     }
1738 
1739     // The lock has been dropped so we can free resources.
1740     // Free up either the old cache or the new cache if we allocated one.
1741     if (to_dealloc_jmeths != NULL) {
1742       FreeHeap(to_dealloc_jmeths);
1743     }
1744     // free up the new ID since it wasn't needed
1745     if (to_dealloc_id != NULL) {
1746       Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
1747     }
1748   }
1749   return id;
1750 }
1751 
1752 // Figure out how many jmethodIDs haven't been allocated, and make
1753 // sure space for them is pre-allocated.  This makes getting all
1754 // method ids much, much faster with classes with more than 8
1755 // methods, and has a *substantial* effect on performance with jvmti
1756 // code that loads all jmethodIDs for all classes.
1757 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1758   int new_jmeths = 0;
1759   int length = methods()->length();
1760   for (int index = start_offset; index < length; index++) {
1761     Method* m = methods()->at(index);
1762     jmethodID id = m->find_jmethod_id_or_null();
1763     if (id == NULL) {
1764       new_jmeths++;
1765     }
1766   }
1767   if (new_jmeths != 0) {
1768     Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1769   }
1770 }
1771 
1772 // Common code to fetch the jmethodID from the cache or update the
1773 // cache with the new jmethodID. This function should never do anything
1774 // that causes the caller to go to a safepoint or we can deadlock with
1775 // the VMThread or have cache consistency issues.
1776 //
1777 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1778             instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1779             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1780             jmethodID** to_dealloc_jmeths_p) {
1781   assert(new_id != NULL, "sanity check");
1782   assert(to_dealloc_id_p != NULL, "sanity check");
1783   assert(to_dealloc_jmeths_p != NULL, "sanity check");
1784   assert(Threads::number_of_threads() == 0 ||
1785          SafepointSynchronize::is_at_safepoint() ||
1786          JmethodIdCreation_lock->owned_by_self(), "sanity check");
1787 
1788   // reacquire the cache - we are locked, single threaded or at a safepoint
1789   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1790   jmethodID  id     = NULL;
1791   size_t     length = 0;
1792 
1793   if (jmeths == NULL ||                         // no cache yet
1794       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
1795     if (jmeths != NULL) {
1796       // copy any existing entries from the old cache
1797       for (size_t index = 0; index < length; index++) {
1798         new_jmeths[index+1] = jmeths[index+1];
1799       }
1800       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
1801     }
1802     ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1803   } else {
1804     // fetch jmethodID (if any) from the existing cache
1805     id = jmeths[idnum+1];
1806     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
1807   }
1808   if (id == NULL) {
1809     // No matching jmethodID in the existing cache or we have a new
1810     // cache or we just grew the cache. This cache write is done here
1811     // by the first thread to win the foot race because a jmethodID
1812     // needs to be unique once it is generally available.
1813     id = new_id;
1814 
1815     // The jmethodID cache can be read while unlocked so we have to
1816     // make sure the new jmethodID is complete before installing it
1817     // in the cache.
1818     OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1819   } else {
1820     *to_dealloc_id_p = new_id; // save new id for later delete
1821   }
1822   return id;
1823 }
1824 
1825 
1826 // Common code to get the jmethodID cache length and the jmethodID
1827 // value at index idnum if there is one.
1828 //
1829 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1830        size_t idnum, size_t *length_p, jmethodID* id_p) {
1831   assert(cache != NULL, "sanity check");
1832   assert(length_p != NULL, "sanity check");
1833   assert(id_p != NULL, "sanity check");
1834 
1835   // cache size is stored in element[0], other elements offset by one
1836   *length_p = (size_t)cache[0];
1837   if (*length_p <= idnum) {  // cache is too short
1838     *id_p = NULL;
1839   } else {
1840     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
1841   }
1842 }
1843 
1844 
1845 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
1846 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1847   size_t idnum = (size_t)method->method_idnum();
1848   jmethodID* jmeths = methods_jmethod_ids_acquire();
1849   size_t length;                                // length assigned as debugging crumb
1850   jmethodID id = NULL;
1851   if (jmeths != NULL &&                         // If there is a cache
1852       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
1853     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
1854   }
1855   return id;
1856 }
1857 
1858 int nmethodBucket::decrement() {
1859   return Atomic::add(-1, (volatile int *)&_count);
1860 }
1861 
1862 //
1863 // Walk the list of dependent nmethods searching for nmethods which
1864 // are dependent on the changes that were passed in and mark them for
1865 // deoptimization.  Returns the number of nmethods found.
1866 //
1867 int nmethodBucket::mark_dependent_nmethods(nmethodBucket* deps, DepChange& changes) {
1868   assert_locked_or_safepoint(CodeCache_lock);
1869   int found = 0;
1870   for (nmethodBucket* b = deps; b != NULL; b = b->next()) {
1871     nmethod* nm = b->get_nmethod();
1872     // since dependencies aren't removed until an nmethod becomes a zombie,
1873     // the dependency list may contain nmethods which aren't alive.
1874     if (b->count() > 0 && nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1875       if (TraceDependencies) {
1876         ResourceMark rm;
1877         tty->print_cr("Marked for deoptimization");
1878         changes.print();
1879         nm->print();
1880         nm->print_dependencies();
1881       }
1882       nm->mark_for_deoptimization();
1883       found++;
1884     }
1885   }
1886   return found;
1887 }
1888 
1889 //
1890 // Add an nmethodBucket to the list of dependencies for this nmethod.
1891 // It's possible that an nmethod has multiple dependencies on this klass
1892 // so a count is kept for each bucket to guarantee that creation and
1893 // deletion of dependencies is consistent. Returns new head of the list.
1894 //
1895 nmethodBucket* nmethodBucket::add_dependent_nmethod(nmethodBucket* deps, nmethod* nm) {
1896   assert_locked_or_safepoint(CodeCache_lock);
1897   for (nmethodBucket* b = deps; b != NULL; b = b->next()) {
1898     if (nm == b->get_nmethod()) {
1899       b->increment();
1900       return deps;
1901     }
1902   }
1903   return new nmethodBucket(nm, deps);
1904 }
1905 
1906 //
1907 // Decrement count of the nmethod in the dependency list and remove
1908 // the bucket completely when the count goes to 0.  This method must
1909 // find a corresponding bucket otherwise there's a bug in the
1910 // recording of dependencies. Returns true if the bucket is ready for reclamation.
1911 //
1912 bool nmethodBucket::remove_dependent_nmethod(nmethodBucket* deps, nmethod* nm) {
1913   assert_locked_or_safepoint(CodeCache_lock);
1914 
1915   for (nmethodBucket* b = deps; b != NULL; b = b->next()) {
1916     if (nm == b->get_nmethod()) {
1917       int val = b->decrement();
1918       guarantee(val >= 0, err_msg("Underflow: %d", val));
1919       return (val == 0);
1920     }
1921   }
1922 #ifdef ASSERT
1923   tty->print_raw_cr("### can't find dependent nmethod");
1924   nm->print();
1925 #endif // ASSERT
1926   ShouldNotReachHere();
1927   return false;
1928 }
1929 
1930 //
1931 // Reclaim all unused buckets. Returns new head of the list.
1932 //
1933 nmethodBucket* nmethodBucket::clean_dependent_nmethods(nmethodBucket* deps) {
1934   nmethodBucket* first = deps;
1935   nmethodBucket* last = NULL;
1936   nmethodBucket* b = first;
1937 
1938   while (b != NULL) {
1939     assert(b->count() >= 0, err_msg("bucket count: %d", b->count()));
1940     nmethodBucket* next = b->next();
1941     if (b->count() == 0) {
1942       if (last == NULL) {
1943         first = next;
1944       } else {
1945         last->set_next(next);
1946       }
1947       delete b;
1948       // last stays the same.
1949     } else {
1950       last = b;
1951     }
1952     b = next;
1953   }
1954   return first;
1955 }
1956 
1957 #ifndef PRODUCT
1958 void nmethodBucket::print_dependent_nmethods(nmethodBucket* deps, bool verbose) {
1959   int idx = 0;
1960   for (nmethodBucket* b = deps; b != NULL; b = b->next()) {
1961     nmethod* nm = b->get_nmethod();
1962     tty->print("[%d] count=%d { ", idx++, b->count());
1963     if (!verbose) {
1964       nm->print_on(tty, "nmethod");
1965       tty->print_cr(" } ");
1966     } else {
1967       nm->print();
1968       nm->print_dependencies();
1969       tty->print_cr("--- } ");
1970     }
1971   }
1972 }
1973 
1974 bool nmethodBucket::is_dependent_nmethod(nmethodBucket* deps, nmethod* nm) {
1975   for (nmethodBucket* b = deps; b != NULL; b = b->next()) {
1976     if (nm == b->get_nmethod()) {
1977 #ifdef ASSERT
1978       int count = b->count();
1979       assert(count >= 0, err_msg("count shouldn't be negative: %d", count));
1980 #endif
1981       return true;
1982     }
1983   }
1984   return false;
1985 }
1986 #endif //PRODUCT
1987 
1988 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
1989   assert_locked_or_safepoint(CodeCache_lock);
1990   return nmethodBucket::mark_dependent_nmethods(_dependencies, changes);
1991 }
1992 
1993 void InstanceKlass::clean_dependent_nmethods() {
1994   assert_locked_or_safepoint(CodeCache_lock);
1995 
1996   if (has_unloaded_dependent()) {
1997     _dependencies = nmethodBucket::clean_dependent_nmethods(_dependencies);
1998     set_has_unloaded_dependent(false);
1999   }
2000 #ifdef ASSERT
2001   else {
2002     // Verification
2003     for (nmethodBucket* b = _dependencies; b != NULL; b = b->next()) {
2004       assert(b->count() >= 0, err_msg("bucket count: %d", b->count()));
2005       assert(b->count() != 0, "empty buckets need to be cleaned");
2006     }
2007   }
2008 #endif
2009 }
2010 
2011 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2012   assert_locked_or_safepoint(CodeCache_lock);
2013   _dependencies = nmethodBucket::add_dependent_nmethod(_dependencies, nm);
2014 }
2015 
2016 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
2017   assert_locked_or_safepoint(CodeCache_lock);
2018 
2019   if (nmethodBucket::remove_dependent_nmethod(_dependencies, nm)) {
2020     set_has_unloaded_dependent(true);
2021   }
2022 }
2023 
2024 #ifndef PRODUCT
2025 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2026   nmethodBucket::print_dependent_nmethods(_dependencies, verbose);
2027 }
2028 
2029 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2030   return nmethodBucket::is_dependent_nmethod(_dependencies, nm);
2031 }
2032 #endif //PRODUCT
2033 
2034 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
2035   assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
2036   if (is_interface()) {
2037     if (ClassUnloading) {
2038       Klass* impl = implementor();
2039       if (impl != NULL) {
2040         if (!impl->is_loader_alive(is_alive)) {
2041           // remove this guy
2042           Klass** klass = adr_implementor();
2043           assert(klass != NULL, "null klass");
2044           if (klass != NULL) {
2045             *klass = NULL;
2046           }
2047         }
2048       }
2049     }
2050   }
2051 }
2052 
2053 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
2054   for (int m = 0; m < methods()->length(); m++) {
2055     MethodData* mdo = methods()->at(m)->method_data();
2056     if (mdo != NULL) {
2057       mdo->clean_method_data(is_alive);
2058     }
2059   }
2060 }
2061 
2062 
2063 static void remove_unshareable_in_class(Klass* k) {
2064   // remove klass's unshareable info
2065   k->remove_unshareable_info();
2066 }
2067 
2068 void InstanceKlass::remove_unshareable_info() {
2069   Klass::remove_unshareable_info();
2070   // Unlink the class
2071   if (is_linked()) {
2072     unlink_class();
2073   }
2074   init_implementor();
2075 
2076   constants()->remove_unshareable_info();
2077 
2078   for (int i = 0; i < methods()->length(); i++) {
2079     Method* m = methods()->at(i);
2080     m->remove_unshareable_info();
2081   }
2082 
2083   // do array classes also.
2084   array_klasses_do(remove_unshareable_in_class);
2085 }
2086 
2087 static void restore_unshareable_in_class(Klass* k, TRAPS) {
2088   // Array classes have null protection domain.
2089   // --> see ArrayKlass::complete_create_array_klass()
2090   k->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2091 }
2092 
2093 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2094   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2095   instanceKlassHandle ik(THREAD, this);
2096 
2097   Array<Method*>* methods = ik->methods();
2098   int num_methods = methods->length();
2099   for (int index2 = 0; index2 < num_methods; ++index2) {
2100     methodHandle m(THREAD, methods->at(index2));
2101     m->restore_unshareable_info(CHECK);
2102   }
2103   if (JvmtiExport::has_redefined_a_class()) {
2104     // Reinitialize vtable because RedefineClasses may have changed some
2105     // entries in this vtable for super classes so the CDS vtable might
2106     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2107     // vtables in the shared system dictionary, only the main one.
2108     // It also redefines the itable too so fix that too.
2109     ResourceMark rm(THREAD);
2110     ik->vtable()->initialize_vtable(false, CHECK);
2111     ik->itable()->initialize_itable(false, CHECK);
2112   }
2113 
2114   // restore constant pool resolved references
2115   ik->constants()->restore_unshareable_info(CHECK);
2116 
2117   ik->array_klasses_do(restore_unshareable_in_class, CHECK);
2118 }
2119 
2120 // returns true IFF is_in_error_state() has been changed as a result of this call.
2121 bool InstanceKlass::check_sharing_error_state() {
2122   assert(DumpSharedSpaces, "should only be called during dumping");
2123   bool old_state = is_in_error_state();
2124 
2125   if (!is_in_error_state()) {
2126     bool bad = false;
2127     for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2128       if (sup->is_in_error_state()) {
2129         bad = true;
2130         break;
2131       }
2132     }
2133     if (!bad) {
2134       Array<Klass*>* interfaces = transitive_interfaces();
2135       for (int i = 0; i < interfaces->length(); i++) {
2136         Klass* iface = interfaces->at(i);
2137         if (InstanceKlass::cast(iface)->is_in_error_state()) {
2138           bad = true;
2139           break;
2140         }
2141       }
2142     }
2143 
2144     if (bad) {
2145       set_in_error_state();
2146     }
2147   }
2148 
2149   return (old_state != is_in_error_state());
2150 }
2151 
2152 static void clear_all_breakpoints(Method* m) {
2153   m->clear_all_breakpoints();
2154 }
2155 
2156 
2157 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2158   // notify the debugger
2159   if (JvmtiExport::should_post_class_unload()) {
2160     JvmtiExport::post_class_unload(ik);
2161   }
2162 
2163   // notify ClassLoadingService of class unload
2164   ClassLoadingService::notify_class_unloaded(ik);
2165 }
2166 
2167 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2168   // Clean up C heap
2169   ik->release_C_heap_structures();
2170   ik->constants()->release_C_heap_structures();
2171 }
2172 
2173 void InstanceKlass::release_C_heap_structures() {
2174 
2175   // Can't release the constant pool here because the constant pool can be
2176   // deallocated separately from the InstanceKlass for default methods and
2177   // redefine classes.
2178 
2179   // Deallocate oop map cache
2180   if (_oop_map_cache != NULL) {
2181     delete _oop_map_cache;
2182     _oop_map_cache = NULL;
2183   }
2184 
2185   // Deallocate JNI identifiers for jfieldIDs
2186   JNIid::deallocate(jni_ids());
2187   set_jni_ids(NULL);
2188 
2189   jmethodID* jmeths = methods_jmethod_ids_acquire();
2190   if (jmeths != (jmethodID*)NULL) {
2191     release_set_methods_jmethod_ids(NULL);
2192     FreeHeap(jmeths);
2193   }
2194 
2195   // Deallocate MemberNameTable
2196   {
2197     Mutex* lock_or_null = SafepointSynchronize::is_at_safepoint() ? NULL : MemberNameTable_lock;
2198     MutexLockerEx ml(lock_or_null, Mutex::_no_safepoint_check_flag);
2199     MemberNameTable* mnt = member_names();
2200     if (mnt != NULL) {
2201       delete mnt;
2202       set_member_names(NULL);
2203     }
2204   }
2205 
2206   // release dependencies
2207   nmethodBucket* b = _dependencies;
2208   _dependencies = NULL;
2209   while (b != NULL) {
2210     nmethodBucket* next = b->next();
2211     delete b;
2212     b = next;
2213   }
2214 
2215   // Deallocate breakpoint records
2216   if (breakpoints() != 0x0) {
2217     methods_do(clear_all_breakpoints);
2218     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2219   }
2220 
2221   // deallocate the cached class file
2222   if (_cached_class_file != NULL) {
2223     os::free(_cached_class_file);
2224     _cached_class_file = NULL;
2225   }
2226 
2227   // Decrement symbol reference counts associated with the unloaded class.
2228   if (_name != NULL) _name->decrement_refcount();
2229   // unreference array name derived from this class name (arrays of an unloaded
2230   // class can't be referenced anymore).
2231   if (_array_name != NULL)  _array_name->decrement_refcount();
2232   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2233 
2234   assert(_total_instanceKlass_count >= 1, "Sanity check");
2235   Atomic::dec(&_total_instanceKlass_count);
2236 }
2237 
2238 void InstanceKlass::set_source_debug_extension(char* array, int length) {
2239   if (array == NULL) {
2240     _source_debug_extension = NULL;
2241   } else {
2242     // Adding one to the attribute length in order to store a null terminator
2243     // character could cause an overflow because the attribute length is
2244     // already coded with an u4 in the classfile, but in practice, it's
2245     // unlikely to happen.
2246     assert((length+1) > length, "Overflow checking");
2247     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2248     for (int i = 0; i < length; i++) {
2249       sde[i] = array[i];
2250     }
2251     sde[length] = '\0';
2252     _source_debug_extension = sde;
2253   }
2254 }
2255 
2256 address InstanceKlass::static_field_addr(int offset) {
2257   return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
2258 }
2259 
2260 
2261 const char* InstanceKlass::signature_name() const {
2262   int hash_len = 0;
2263   char hash_buf[40];
2264 
2265   // If this is an anonymous class, append a hash to make the name unique
2266   if (is_anonymous()) {
2267     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2268     jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2269     hash_len = (int)strlen(hash_buf);
2270   }
2271 
2272   // Get the internal name as a c string
2273   const char* src = (const char*) (name()->as_C_string());
2274   const int src_length = (int)strlen(src);
2275 
2276   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2277 
2278   // Add L as type indicator
2279   int dest_index = 0;
2280   dest[dest_index++] = 'L';
2281 
2282   // Add the actual class name
2283   for (int src_index = 0; src_index < src_length; ) {
2284     dest[dest_index++] = src[src_index++];
2285   }
2286 
2287   // If we have a hash, append it
2288   for (int hash_index = 0; hash_index < hash_len; ) {
2289     dest[dest_index++] = hash_buf[hash_index++];
2290   }
2291 
2292   // Add the semicolon and the NULL
2293   dest[dest_index++] = ';';
2294   dest[dest_index] = '\0';
2295   return dest;
2296 }
2297 
2298 // different verisons of is_same_class_package
2299 bool InstanceKlass::is_same_class_package(Klass* class2) {
2300   Klass* class1 = this;
2301   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2302   Symbol* classname1 = class1->name();
2303 
2304   if (class2->oop_is_objArray()) {
2305     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2306   }
2307   oop classloader2;
2308   if (class2->oop_is_instance()) {
2309     classloader2 = InstanceKlass::cast(class2)->class_loader();
2310   } else {
2311     assert(class2->oop_is_typeArray(), "should be type array");
2312     classloader2 = NULL;
2313   }
2314   Symbol* classname2 = class2->name();
2315 
2316   return InstanceKlass::is_same_class_package(classloader1, classname1,
2317                                               classloader2, classname2);
2318 }
2319 
2320 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
2321   Klass* class1 = this;
2322   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
2323   Symbol* classname1 = class1->name();
2324 
2325   return InstanceKlass::is_same_class_package(classloader1, classname1,
2326                                               classloader2, classname2);
2327 }
2328 
2329 // return true if two classes are in the same package, classloader
2330 // and classname information is enough to determine a class's package
2331 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
2332                                           oop class_loader2, Symbol* class_name2) {
2333   if (class_loader1 != class_loader2) {
2334     return false;
2335   } else if (class_name1 == class_name2) {
2336     return true;                // skip painful bytewise comparison
2337   } else {
2338     ResourceMark rm;
2339 
2340     // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
2341     // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
2342     // Otherwise, we just compare jbyte values between the strings.
2343     const jbyte *name1 = class_name1->base();
2344     const jbyte *name2 = class_name2->base();
2345 
2346     const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
2347     const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
2348 
2349     if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
2350       // One of the two doesn't have a package.  Only return true
2351       // if the other one also doesn't have a package.
2352       return last_slash1 == last_slash2;
2353     } else {
2354       // Skip over '['s
2355       if (*name1 == '[') {
2356         do {
2357           name1++;
2358         } while (*name1 == '[');
2359         if (*name1 != 'L') {
2360           // Something is terribly wrong.  Shouldn't be here.
2361           return false;
2362         }
2363       }
2364       if (*name2 == '[') {
2365         do {
2366           name2++;
2367         } while (*name2 == '[');
2368         if (*name2 != 'L') {
2369           // Something is terribly wrong.  Shouldn't be here.
2370           return false;
2371         }
2372       }
2373 
2374       // Check that package part is identical
2375       int length1 = last_slash1 - name1;
2376       int length2 = last_slash2 - name2;
2377 
2378       return UTF8::equal(name1, length1, name2, length2);
2379     }
2380   }
2381 }
2382 
2383 // Returns true iff super_method can be overridden by a method in targetclassname
2384 // See JSL 3rd edition 8.4.6.1
2385 // Assumes name-signature match
2386 // "this" is InstanceKlass of super_method which must exist
2387 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2388 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2389    // Private methods can not be overridden
2390    if (super_method->is_private()) {
2391      return false;
2392    }
2393    // If super method is accessible, then override
2394    if ((super_method->is_protected()) ||
2395        (super_method->is_public())) {
2396      return true;
2397    }
2398    // Package-private methods are not inherited outside of package
2399    assert(super_method->is_package_private(), "must be package private");
2400    return(is_same_class_package(targetclassloader(), targetclassname));
2401 }
2402 
2403 /* defined for now in jvm.cpp, for historical reasons *--
2404 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2405                                                      Symbol*& simple_name_result, TRAPS) {
2406   ...
2407 }
2408 */
2409 
2410 // tell if two classes have the same enclosing class (at package level)
2411 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2412                                                 Klass* class2_oop, TRAPS) {
2413   if (class2_oop == class1())                       return true;
2414   if (!class2_oop->oop_is_instance())  return false;
2415   instanceKlassHandle class2(THREAD, class2_oop);
2416 
2417   // must be in same package before we try anything else
2418   if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2419     return false;
2420 
2421   // As long as there is an outer1.getEnclosingClass,
2422   // shift the search outward.
2423   instanceKlassHandle outer1 = class1;
2424   for (;;) {
2425     // As we walk along, look for equalities between outer1 and class2.
2426     // Eventually, the walks will terminate as outer1 stops
2427     // at the top-level class around the original class.
2428     bool ignore_inner_is_member;
2429     Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2430                                                     CHECK_false);
2431     if (next == NULL)  break;
2432     if (next == class2())  return true;
2433     outer1 = instanceKlassHandle(THREAD, next);
2434   }
2435 
2436   // Now do the same for class2.
2437   instanceKlassHandle outer2 = class2;
2438   for (;;) {
2439     bool ignore_inner_is_member;
2440     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2441                                                     CHECK_false);
2442     if (next == NULL)  break;
2443     // Might as well check the new outer against all available values.
2444     if (next == class1())  return true;
2445     if (next == outer1())  return true;
2446     outer2 = instanceKlassHandle(THREAD, next);
2447   }
2448 
2449   // If by this point we have not found an equality between the
2450   // two classes, we know they are in separate package members.
2451   return false;
2452 }
2453 
2454 bool InstanceKlass::find_inner_classes_attr(instanceKlassHandle k, int* ooff, int* noff, TRAPS) {
2455   constantPoolHandle i_cp(THREAD, k->constants());
2456   for (InnerClassesIterator iter(k); !iter.done(); iter.next()) {
2457     int ioff = iter.inner_class_info_index();
2458     if (ioff != 0) {
2459       // Check to see if the name matches the class we're looking for
2460       // before attempting to find the class.
2461       if (i_cp->klass_name_at_matches(k, ioff)) {
2462         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2463         if (k() == inner_klass) {
2464           *ooff = iter.outer_class_info_index();
2465           *noff = iter.inner_name_index();
2466           return true;
2467         }
2468       }
2469     }
2470   }
2471   return false;
2472 }
2473 
2474 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle k, bool* inner_is_member, TRAPS) {
2475   instanceKlassHandle outer_klass;
2476   *inner_is_member = false;
2477   int ooff = 0, noff = 0;
2478   if (find_inner_classes_attr(k, &ooff, &noff, THREAD)) {
2479     constantPoolHandle i_cp(THREAD, k->constants());
2480     if (ooff != 0) {
2481       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2482       outer_klass = instanceKlassHandle(THREAD, ok);
2483       *inner_is_member = true;
2484     }
2485     if (outer_klass.is_null()) {
2486       // It may be anonymous; try for that.
2487       int encl_method_class_idx = k->enclosing_method_class_index();
2488       if (encl_method_class_idx != 0) {
2489         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2490         outer_klass = instanceKlassHandle(THREAD, ok);
2491         *inner_is_member = false;
2492       }
2493     }
2494   }
2495 
2496   // If no inner class attribute found for this class.
2497   if (outer_klass.is_null())  return NULL;
2498 
2499   // Throws an exception if outer klass has not declared k as an inner klass
2500   // We need evidence that each klass knows about the other, or else
2501   // the system could allow a spoof of an inner class to gain access rights.
2502   Reflection::check_for_inner_class(outer_klass, k, *inner_is_member, CHECK_NULL);
2503   return outer_klass();
2504 }
2505 
2506 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2507   jint access = access_flags().as_int();
2508 
2509   // But check if it happens to be member class.
2510   instanceKlassHandle ik(THREAD, this);
2511   InnerClassesIterator iter(ik);
2512   for (; !iter.done(); iter.next()) {
2513     int ioff = iter.inner_class_info_index();
2514     // Inner class attribute can be zero, skip it.
2515     // Strange but true:  JVM spec. allows null inner class refs.
2516     if (ioff == 0) continue;
2517 
2518     // only look at classes that are already loaded
2519     // since we are looking for the flags for our self.
2520     Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2521     if ((ik->name() == inner_name)) {
2522       // This is really a member class.
2523       access = iter.inner_access_flags();
2524       break;
2525     }
2526   }
2527   // Remember to strip ACC_SUPER bit
2528   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2529 }
2530 
2531 jint InstanceKlass::jvmti_class_status() const {
2532   jint result = 0;
2533 
2534   if (is_linked()) {
2535     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2536   }
2537 
2538   if (is_initialized()) {
2539     assert(is_linked(), "Class status is not consistent");
2540     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2541   }
2542   if (is_in_error_state()) {
2543     result |= JVMTI_CLASS_STATUS_ERROR;
2544   }
2545   return result;
2546 }
2547 
2548 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2549   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2550   int method_table_offset_in_words = ioe->offset()/wordSize;
2551   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2552                        / itableOffsetEntry::size();
2553 
2554   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2555     // If the interface isn't implemented by the receiver class,
2556     // the VM should throw IncompatibleClassChangeError.
2557     if (cnt >= nof_interfaces) {
2558       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2559     }
2560 
2561     Klass* ik = ioe->interface_klass();
2562     if (ik == holder) break;
2563   }
2564 
2565   itableMethodEntry* ime = ioe->first_method_entry(this);
2566   Method* m = ime[index].method();
2567   if (m == NULL) {
2568     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2569   }
2570   return m;
2571 }
2572 
2573 
2574 #if INCLUDE_JVMTI
2575 // update default_methods for redefineclasses for methods that are
2576 // not yet in the vtable due to concurrent subclass define and superinterface
2577 // redefinition
2578 // Note: those in the vtable, should have been updated via adjust_method_entries
2579 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2580   // search the default_methods for uses of either obsolete or EMCP methods
2581   if (default_methods() != NULL) {
2582     for (int index = 0; index < default_methods()->length(); index ++) {
2583       Method* old_method = default_methods()->at(index);
2584       if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2585         continue; // skip uninteresting entries
2586       }
2587       assert(!old_method->is_deleted(), "default methods may not be deleted");
2588 
2589       Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2590 
2591       assert(new_method != NULL, "method_with_idnum() should not be NULL");
2592       assert(old_method != new_method, "sanity check");
2593 
2594       default_methods()->at_put(index, new_method);
2595       if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
2596         if (!(*trace_name_printed)) {
2597           // RC_TRACE_MESG macro has an embedded ResourceMark
2598           RC_TRACE_MESG(("adjust: klassname=%s default methods from name=%s",
2599                          external_name(),
2600                          old_method->method_holder()->external_name()));
2601           *trace_name_printed = true;
2602         }
2603         RC_TRACE(0x00100000, ("default method update: %s(%s) ",
2604                               new_method->name()->as_C_string(),
2605                               new_method->signature()->as_C_string()));
2606       }
2607     }
2608   }
2609 }
2610 #endif // INCLUDE_JVMTI
2611 
2612 // On-stack replacement stuff
2613 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2614   // only one compilation can be active
2615   {
2616     // This is a short non-blocking critical region, so the no safepoint check is ok.
2617     MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2618     assert(n->is_osr_method(), "wrong kind of nmethod");
2619     n->set_osr_link(osr_nmethods_head());
2620     set_osr_nmethods_head(n);
2621     // Raise the highest osr level if necessary
2622     if (TieredCompilation) {
2623       Method* m = n->method();
2624       m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2625     }
2626   }
2627 
2628   // Get rid of the osr methods for the same bci that have lower levels.
2629   if (TieredCompilation) {
2630     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2631       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2632       if (inv != NULL && inv->is_in_use()) {
2633         inv->make_not_entrant();
2634       }
2635     }
2636   }
2637 }
2638 
2639 
2640 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
2641   // This is a short non-blocking critical region, so the no safepoint check is ok.
2642   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2643   assert(n->is_osr_method(), "wrong kind of nmethod");
2644   nmethod* last = NULL;
2645   nmethod* cur  = osr_nmethods_head();
2646   int max_level = CompLevel_none;  // Find the max comp level excluding n
2647   Method* m = n->method();
2648   // Search for match
2649   while(cur != NULL && cur != n) {
2650     if (TieredCompilation && m == cur->method()) {
2651       // Find max level before n
2652       max_level = MAX2(max_level, cur->comp_level());
2653     }
2654     last = cur;
2655     cur = cur->osr_link();
2656   }
2657   nmethod* next = NULL;
2658   if (cur == n) {
2659     next = cur->osr_link();
2660     if (last == NULL) {
2661       // Remove first element
2662       set_osr_nmethods_head(next);
2663     } else {
2664       last->set_osr_link(next);
2665     }
2666   }
2667   n->set_osr_link(NULL);
2668   if (TieredCompilation) {
2669     cur = next;
2670     while (cur != NULL) {
2671       // Find max level after n
2672       if (m == cur->method()) {
2673         max_level = MAX2(max_level, cur->comp_level());
2674       }
2675       cur = cur->osr_link();
2676     }
2677     m->set_highest_osr_comp_level(max_level);
2678   }
2679 }
2680 
2681 int InstanceKlass::mark_osr_nmethods(const Method* m) {
2682   // This is a short non-blocking critical region, so the no safepoint check is ok.
2683   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2684   nmethod* osr = osr_nmethods_head();
2685   int found = 0;
2686   while (osr != NULL) {
2687     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2688     if (osr->method() == m) {
2689       osr->mark_for_deoptimization();
2690       found++;
2691     }
2692     osr = osr->osr_link();
2693   }
2694   return found;
2695 }
2696 
2697 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2698   // This is a short non-blocking critical region, so the no safepoint check is ok.
2699   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2700   nmethod* osr = osr_nmethods_head();
2701   nmethod* best = NULL;
2702   while (osr != NULL) {
2703     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2704     // There can be a time when a c1 osr method exists but we are waiting
2705     // for a c2 version. When c2 completes its osr nmethod we will trash
2706     // the c1 version and only be able to find the c2 version. However
2707     // while we overflow in the c1 code at back branches we don't want to
2708     // try and switch to the same code as we are already running
2709 
2710     if (osr->method() == m &&
2711         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2712       if (match_level) {
2713         if (osr->comp_level() == comp_level) {
2714           // Found a match - return it.
2715           return osr;
2716         }
2717       } else {
2718         if (best == NULL || (osr->comp_level() > best->comp_level())) {
2719           if (osr->comp_level() == CompLevel_highest_tier) {
2720             // Found the best possible - return it.
2721             return osr;
2722           }
2723           best = osr;
2724         }
2725       }
2726     }
2727     osr = osr->osr_link();
2728   }
2729   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2730     return best;
2731   }
2732   return NULL;
2733 }
2734 
2735 bool InstanceKlass::add_member_name(Handle mem_name) {
2736   jweak mem_name_wref = JNIHandles::make_weak_global(mem_name);
2737   MutexLocker ml(MemberNameTable_lock);
2738   DEBUG_ONLY(No_Safepoint_Verifier nsv);
2739 
2740   // Check if method has been redefined while taking out MemberNameTable_lock, if so
2741   // return false.  We cannot cache obsolete methods. They will crash when the function
2742   // is called!
2743   Method* method = (Method*)java_lang_invoke_MemberName::vmtarget(mem_name());
2744   if (method->is_obsolete()) {
2745     return false;
2746   } else if (method->is_old()) {
2747     // Replace method with redefined version
2748     java_lang_invoke_MemberName::set_vmtarget(mem_name(), method_with_idnum(method->method_idnum()));
2749   }
2750 
2751   if (_member_names == NULL) {
2752     _member_names = new (ResourceObj::C_HEAP, mtClass) MemberNameTable(idnum_allocated_count());
2753   }
2754   _member_names->add_member_name(mem_name_wref);
2755   return true;
2756 }
2757 
2758 // -----------------------------------------------------------------------------------------------------
2759 // Printing
2760 
2761 #ifndef PRODUCT
2762 
2763 #define BULLET  " - "
2764 
2765 static const char* state_names[] = {
2766   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2767 };
2768 
2769 static void print_vtable(intptr_t* start, int len, outputStream* st) {
2770   for (int i = 0; i < len; i++) {
2771     intptr_t e = start[i];
2772     st->print("%d : " INTPTR_FORMAT, i, e);
2773     if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2774       st->print(" ");
2775       ((Metadata*)e)->print_value_on(st);
2776     }
2777     st->cr();
2778   }
2779 }
2780 
2781 void InstanceKlass::print_on(outputStream* st) const {
2782   assert(is_klass(), "must be klass");
2783   Klass::print_on(st);
2784 
2785   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
2786   st->print(BULLET"klass size:        %d", size());                               st->cr();
2787   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
2788   st->print(BULLET"state:             "); st->print_cr("%s", state_names[_init_state]);
2789   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
2790   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
2791   st->print(BULLET"sub:               ");
2792   Klass* sub = subklass();
2793   int n;
2794   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2795     if (n < MaxSubklassPrintSize) {
2796       sub->print_value_on(st);
2797       st->print("   ");
2798     }
2799   }
2800   if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
2801   st->cr();
2802 
2803   if (is_interface()) {
2804     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
2805     if (nof_implementors() == 1) {
2806       st->print_cr(BULLET"implementor:    ");
2807       st->print("   ");
2808       implementor()->print_value_on(st);
2809       st->cr();
2810     }
2811   }
2812 
2813   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2814   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
2815   if (Verbose || WizardMode) {
2816     Array<Method*>* method_array = methods();
2817     for (int i = 0; i < method_array->length(); i++) {
2818       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2819     }
2820   }
2821   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
2822   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
2823   if (Verbose && default_methods() != NULL) {
2824     Array<Method*>* method_array = default_methods();
2825     for (int i = 0; i < method_array->length(); i++) {
2826       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2827     }
2828   }
2829   if (default_vtable_indices() != NULL) {
2830     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
2831   }
2832   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
2833   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2834   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
2835   if (class_loader_data() != NULL) {
2836     st->print(BULLET"class loader data:  ");
2837     class_loader_data()->print_value_on(st);
2838     st->cr();
2839   }
2840   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
2841   if (source_file_name() != NULL) {
2842     st->print(BULLET"source file:       ");
2843     source_file_name()->print_value_on(st);
2844     st->cr();
2845   }
2846   if (source_debug_extension() != NULL) {
2847     st->print(BULLET"source debug extension:       ");
2848     st->print("%s", source_debug_extension());
2849     st->cr();
2850   }
2851   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
2852   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
2853   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
2854   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
2855   {
2856     bool have_pv = false;
2857     // previous versions are linked together through the InstanceKlass
2858     for (InstanceKlass* pv_node = _previous_versions;
2859          pv_node != NULL;
2860          pv_node = pv_node->previous_versions()) {
2861       if (!have_pv)
2862         st->print(BULLET"previous version:  ");
2863       have_pv = true;
2864       pv_node->constants()->print_value_on(st);
2865     }
2866     if (have_pv) st->cr();
2867   }
2868 
2869   if (generic_signature() != NULL) {
2870     st->print(BULLET"generic signature: ");
2871     generic_signature()->print_value_on(st);
2872     st->cr();
2873   }
2874   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
2875   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
2876   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable());  st->cr();
2877   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
2878   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
2879   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
2880   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2881   FieldPrinter print_static_field(st);
2882   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2883   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2884   FieldPrinter print_nonstatic_field(st);
2885   ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
2886 
2887   st->print(BULLET"non-static oop maps: ");
2888   OopMapBlock* map     = start_of_nonstatic_oop_maps();
2889   OopMapBlock* end_map = map + nonstatic_oop_map_count();
2890   while (map < end_map) {
2891     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2892     map++;
2893   }
2894   st->cr();
2895 }
2896 
2897 #endif //PRODUCT
2898 
2899 void InstanceKlass::print_value_on(outputStream* st) const {
2900   assert(is_klass(), "must be klass");
2901   if (Verbose || WizardMode)  access_flags().print_on(st);
2902   name()->print_value_on(st);
2903 }
2904 
2905 #ifndef PRODUCT
2906 
2907 void FieldPrinter::do_field(fieldDescriptor* fd) {
2908   _st->print(BULLET);
2909    if (_obj == NULL) {
2910      fd->print_on(_st);
2911      _st->cr();
2912    } else {
2913      fd->print_on_for(_st, _obj);
2914      _st->cr();
2915    }
2916 }
2917 
2918 
2919 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
2920   Klass::oop_print_on(obj, st);
2921 
2922   if (this == SystemDictionary::String_klass()) {
2923     typeArrayOop value  = java_lang_String::value(obj);
2924     juint        offset = java_lang_String::offset(obj);
2925     juint        length = java_lang_String::length(obj);
2926     if (value != NULL &&
2927         value->is_typeArray() &&
2928         offset          <= (juint) value->length() &&
2929         offset + length <= (juint) value->length()) {
2930       st->print(BULLET"string: ");
2931       java_lang_String::print(obj, st);
2932       st->cr();
2933       if (!WizardMode)  return;  // that is enough
2934     }
2935   }
2936 
2937   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
2938   FieldPrinter print_field(st, obj);
2939   do_nonstatic_fields(&print_field);
2940 
2941   if (this == SystemDictionary::Class_klass()) {
2942     st->print(BULLET"signature: ");
2943     java_lang_Class::print_signature(obj, st);
2944     st->cr();
2945     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
2946     st->print(BULLET"fake entry for mirror: ");
2947     mirrored_klass->print_value_on_maybe_null(st);
2948     st->cr();
2949     Klass* array_klass = java_lang_Class::array_klass(obj);
2950     st->print(BULLET"fake entry for array: ");
2951     array_klass->print_value_on_maybe_null(st);
2952     st->cr();
2953     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
2954     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
2955     Klass* real_klass = java_lang_Class::as_Klass(obj);
2956     if (real_klass != NULL && real_klass->oop_is_instance()) {
2957       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
2958     }
2959   } else if (this == SystemDictionary::MethodType_klass()) {
2960     st->print(BULLET"signature: ");
2961     java_lang_invoke_MethodType::print_signature(obj, st);
2962     st->cr();
2963   }
2964 }
2965 
2966 #endif //PRODUCT
2967 
2968 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
2969   st->print("a ");
2970   name()->print_value_on(st);
2971   obj->print_address_on(st);
2972   if (this == SystemDictionary::String_klass()
2973       && java_lang_String::value(obj) != NULL) {
2974     ResourceMark rm;
2975     int len = java_lang_String::length(obj);
2976     int plen = (len < 24 ? len : 12);
2977     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
2978     st->print(" = \"%s\"", str);
2979     if (len > plen)
2980       st->print("...[%d]", len);
2981   } else if (this == SystemDictionary::Class_klass()) {
2982     Klass* k = java_lang_Class::as_Klass(obj);
2983     st->print(" = ");
2984     if (k != NULL) {
2985       k->print_value_on(st);
2986     } else {
2987       const char* tname = type2name(java_lang_Class::primitive_type(obj));
2988       st->print("%s", tname ? tname : "type?");
2989     }
2990   } else if (this == SystemDictionary::MethodType_klass()) {
2991     st->print(" = ");
2992     java_lang_invoke_MethodType::print_signature(obj, st);
2993   } else if (java_lang_boxing_object::is_instance(obj)) {
2994     st->print(" = ");
2995     java_lang_boxing_object::print(obj, st);
2996   } else if (this == SystemDictionary::LambdaForm_klass()) {
2997     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
2998     if (vmentry != NULL) {
2999       st->print(" => ");
3000       vmentry->print_value_on(st);
3001     }
3002   } else if (this == SystemDictionary::MemberName_klass()) {
3003     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3004     if (vmtarget != NULL) {
3005       st->print(" = ");
3006       vmtarget->print_value_on(st);
3007     } else {
3008       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3009       st->print(".");
3010       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3011     }
3012   }
3013 }
3014 
3015 const char* InstanceKlass::internal_name() const {
3016   return external_name();
3017 }
3018 
3019 #if INCLUDE_SERVICES
3020 // Size Statistics
3021 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3022   Klass::collect_statistics(sz);
3023 
3024   sz->_inst_size  = HeapWordSize * size_helper();
3025   sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
3026   sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
3027   sz->_nonstatic_oopmap_bytes = HeapWordSize *
3028         ((is_interface() || is_anonymous()) ?
3029          align_object_offset(nonstatic_oop_map_size()) :
3030          nonstatic_oop_map_size());
3031 
3032   int n = 0;
3033   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
3034   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
3035   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
3036   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3037   n += (sz->_fields_bytes                = sz->count_array(fields()));
3038   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
3039   sz->_ro_bytes += n;
3040 
3041   const ConstantPool* cp = constants();
3042   if (cp) {
3043     cp->collect_statistics(sz);
3044   }
3045 
3046   const Annotations* anno = annotations();
3047   if (anno) {
3048     anno->collect_statistics(sz);
3049   }
3050 
3051   const Array<Method*>* methods_array = methods();
3052   if (methods()) {
3053     for (int i = 0; i < methods_array->length(); i++) {
3054       Method* method = methods_array->at(i);
3055       if (method) {
3056         sz->_method_count ++;
3057         method->collect_statistics(sz);
3058       }
3059     }
3060   }
3061 }
3062 #endif // INCLUDE_SERVICES
3063 
3064 // Verification
3065 
3066 class VerifyFieldClosure: public OopClosure {
3067  protected:
3068   template <class T> void do_oop_work(T* p) {
3069     oop obj = oopDesc::load_decode_heap_oop(p);
3070     if (!obj->is_oop_or_null()) {
3071       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
3072       Universe::print();
3073       guarantee(false, "boom");
3074     }
3075   }
3076  public:
3077   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3078   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3079 };
3080 
3081 void InstanceKlass::verify_on(outputStream* st) {
3082 #ifndef PRODUCT
3083   // Avoid redundant verifies, this really should be in product.
3084   if (_verify_count == Universe::verify_count()) return;
3085   _verify_count = Universe::verify_count();
3086 #endif
3087 
3088   // Verify Klass
3089   Klass::verify_on(st);
3090 
3091   // Verify that klass is present in ClassLoaderData
3092   guarantee(class_loader_data()->contains_klass(this),
3093             "this class isn't found in class loader data");
3094 
3095   // Verify vtables
3096   if (is_linked()) {
3097     ResourceMark rm;
3098     // $$$ This used to be done only for m/s collections.  Doing it
3099     // always seemed a valid generalization.  (DLD -- 6/00)
3100     vtable()->verify(st);
3101   }
3102 
3103   // Verify first subklass
3104   if (subklass() != NULL) {
3105     guarantee(subklass()->is_klass(), "should be klass");
3106   }
3107 
3108   // Verify siblings
3109   Klass* super = this->super();
3110   Klass* sib = next_sibling();
3111   if (sib != NULL) {
3112     if (sib == this) {
3113       fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
3114     }
3115 
3116     guarantee(sib->is_klass(), "should be klass");
3117     guarantee(sib->super() == super, "siblings should have same superklass");
3118   }
3119 
3120   // Verify implementor fields
3121   Klass* im = implementor();
3122   if (im != NULL) {
3123     guarantee(is_interface(), "only interfaces should have implementor set");
3124     guarantee(im->is_klass(), "should be klass");
3125     guarantee(!im->is_interface() || im == this,
3126       "implementors cannot be interfaces");
3127   }
3128 
3129   // Verify local interfaces
3130   if (local_interfaces()) {
3131     Array<Klass*>* local_interfaces = this->local_interfaces();
3132     for (int j = 0; j < local_interfaces->length(); j++) {
3133       Klass* e = local_interfaces->at(j);
3134       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3135     }
3136   }
3137 
3138   // Verify transitive interfaces
3139   if (transitive_interfaces() != NULL) {
3140     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3141     for (int j = 0; j < transitive_interfaces->length(); j++) {
3142       Klass* e = transitive_interfaces->at(j);
3143       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3144     }
3145   }
3146 
3147   // Verify methods
3148   if (methods() != NULL) {
3149     Array<Method*>* methods = this->methods();
3150     for (int j = 0; j < methods->length(); j++) {
3151       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3152     }
3153     for (int j = 0; j < methods->length() - 1; j++) {
3154       Method* m1 = methods->at(j);
3155       Method* m2 = methods->at(j + 1);
3156       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3157     }
3158   }
3159 
3160   // Verify method ordering
3161   if (method_ordering() != NULL) {
3162     Array<int>* method_ordering = this->method_ordering();
3163     int length = method_ordering->length();
3164     if (JvmtiExport::can_maintain_original_method_order() ||
3165         ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3166       guarantee(length == methods()->length(), "invalid method ordering length");
3167       jlong sum = 0;
3168       for (int j = 0; j < length; j++) {
3169         int original_index = method_ordering->at(j);
3170         guarantee(original_index >= 0, "invalid method ordering index");
3171         guarantee(original_index < length, "invalid method ordering index");
3172         sum += original_index;
3173       }
3174       // Verify sum of indices 0,1,...,length-1
3175       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3176     } else {
3177       guarantee(length == 0, "invalid method ordering length");
3178     }
3179   }
3180 
3181   // Verify default methods
3182   if (default_methods() != NULL) {
3183     Array<Method*>* methods = this->default_methods();
3184     for (int j = 0; j < methods->length(); j++) {
3185       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3186     }
3187     for (int j = 0; j < methods->length() - 1; j++) {
3188       Method* m1 = methods->at(j);
3189       Method* m2 = methods->at(j + 1);
3190       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3191     }
3192   }
3193 
3194   // Verify JNI static field identifiers
3195   if (jni_ids() != NULL) {
3196     jni_ids()->verify(this);
3197   }
3198 
3199   // Verify other fields
3200   if (array_klasses() != NULL) {
3201     guarantee(array_klasses()->is_klass(), "should be klass");
3202   }
3203   if (constants() != NULL) {
3204     guarantee(constants()->is_constantPool(), "should be constant pool");
3205   }
3206   const Klass* host = host_klass();
3207   if (host != NULL) {
3208     guarantee(host->is_klass(), "should be klass");
3209   }
3210 }
3211 
3212 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3213   Klass::oop_verify_on(obj, st);
3214   VerifyFieldClosure blk;
3215   obj->oop_iterate_no_header(&blk);
3216 }
3217 
3218 
3219 // JNIid class for jfieldIDs only
3220 // Note to reviewers:
3221 // These JNI functions are just moved over to column 1 and not changed
3222 // in the compressed oops workspace.
3223 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3224   _holder = holder;
3225   _offset = offset;
3226   _next = next;
3227   debug_only(_is_static_field_id = false;)
3228 }
3229 
3230 
3231 JNIid* JNIid::find(int offset) {
3232   JNIid* current = this;
3233   while (current != NULL) {
3234     if (current->offset() == offset) return current;
3235     current = current->next();
3236   }
3237   return NULL;
3238 }
3239 
3240 void JNIid::deallocate(JNIid* current) {
3241   while (current != NULL) {
3242     JNIid* next = current->next();
3243     delete current;
3244     current = next;
3245   }
3246 }
3247 
3248 
3249 void JNIid::verify(Klass* holder) {
3250   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3251   int end_field_offset;
3252   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3253 
3254   JNIid* current = this;
3255   while (current != NULL) {
3256     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3257 #ifdef ASSERT
3258     int o = current->offset();
3259     if (current->is_static_field_id()) {
3260       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3261     }
3262 #endif
3263     current = current->next();
3264   }
3265 }
3266 
3267 
3268 #ifdef ASSERT
3269 void InstanceKlass::set_init_state(ClassState state) {
3270   bool good_state = is_shared() ? (_init_state <= state)
3271                                                : (_init_state < state);
3272   assert(good_state || state == allocated, "illegal state transition");
3273   _init_state = (u1)state;
3274 }
3275 #endif
3276 
3277 
3278 
3279 // RedefineClasses() support for previous versions:
3280 int InstanceKlass::_previous_version_count = 0;
3281 
3282 // Purge previous versions before adding new previous versions of the class.
3283 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
3284   if (ik->previous_versions() != NULL) {
3285     // This klass has previous versions so see what we can cleanup
3286     // while it is safe to do so.
3287 
3288     int deleted_count = 0;    // leave debugging breadcrumbs
3289     int live_count = 0;
3290     ClassLoaderData* loader_data = ik->class_loader_data();
3291     assert(loader_data != NULL, "should never be null");
3292 
3293     // RC_TRACE macro has an embedded ResourceMark
3294     RC_TRACE(0x00000200, ("purge: %s: previous versions", ik->external_name()));
3295 
3296     // previous versions are linked together through the InstanceKlass
3297     InstanceKlass* pv_node = ik->previous_versions();
3298     InstanceKlass* last = ik;
3299     int version = 0;
3300 
3301     // check the previous versions list
3302     for (; pv_node != NULL; ) {
3303 
3304       ConstantPool* pvcp = pv_node->constants();
3305       assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3306 
3307       if (!pvcp->on_stack()) {
3308         // If the constant pool isn't on stack, none of the methods
3309         // are executing.  Unlink this previous_version.
3310         // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3311         // so will be deallocated during the next phase of class unloading.
3312         RC_TRACE(0x00000200, ("purge: previous version " INTPTR_FORMAT " is dead",
3313                               pv_node));
3314         // For debugging purposes.
3315         pv_node->set_is_scratch_class();
3316         pv_node->class_loader_data()->add_to_deallocate_list(pv_node);
3317         pv_node = pv_node->previous_versions();
3318         last->link_previous_versions(pv_node);
3319         deleted_count++;
3320         version++;
3321         continue;
3322       } else {
3323         RC_TRACE(0x00000200, ("purge: previous version " INTPTR_FORMAT " is alive",
3324                               pv_node));
3325         assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3326         guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3327         live_count++;
3328       }
3329 
3330       // At least one method is live in this previous version.
3331       // Reset dead EMCP methods not to get breakpoints.
3332       // All methods are deallocated when all of the methods for this class are no
3333       // longer running.
3334       Array<Method*>* method_refs = pv_node->methods();
3335       if (method_refs != NULL) {
3336         RC_TRACE(0x00000200, ("purge: previous methods length=%d",
3337           method_refs->length()));
3338         for (int j = 0; j < method_refs->length(); j++) {
3339           Method* method = method_refs->at(j);
3340 
3341           if (!method->on_stack()) {
3342             // no breakpoints for non-running methods
3343             if (method->is_running_emcp()) {
3344               method->set_running_emcp(false);
3345             }
3346           } else {
3347             assert (method->is_obsolete() || method->is_running_emcp(),
3348                     "emcp method cannot run after emcp bit is cleared");
3349             // RC_TRACE macro has an embedded ResourceMark
3350             RC_TRACE(0x00000200,
3351               ("purge: %s(%s): prev method @%d in version @%d is alive",
3352               method->name()->as_C_string(),
3353               method->signature()->as_C_string(), j, version));
3354           }
3355         }
3356       }
3357       // next previous version
3358       last = pv_node;
3359       pv_node = pv_node->previous_versions();
3360       version++;
3361     }
3362     RC_TRACE(0x00000200,
3363       ("purge: previous version stats: live=%d, deleted=%d", live_count,
3364       deleted_count));
3365   }
3366 }
3367 
3368 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3369                                                 int emcp_method_count) {
3370   int obsolete_method_count = old_methods->length() - emcp_method_count;
3371 
3372   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3373       _previous_versions != NULL) {
3374     // We have a mix of obsolete and EMCP methods so we have to
3375     // clear out any matching EMCP method entries the hard way.
3376     int local_count = 0;
3377     for (int i = 0; i < old_methods->length(); i++) {
3378       Method* old_method = old_methods->at(i);
3379       if (old_method->is_obsolete()) {
3380         // only obsolete methods are interesting
3381         Symbol* m_name = old_method->name();
3382         Symbol* m_signature = old_method->signature();
3383 
3384         // previous versions are linked together through the InstanceKlass
3385         int j = 0;
3386         for (InstanceKlass* prev_version = _previous_versions;
3387              prev_version != NULL;
3388              prev_version = prev_version->previous_versions(), j++) {
3389 
3390           Array<Method*>* method_refs = prev_version->methods();
3391           for (int k = 0; k < method_refs->length(); k++) {
3392             Method* method = method_refs->at(k);
3393 
3394             if (!method->is_obsolete() &&
3395                 method->name() == m_name &&
3396                 method->signature() == m_signature) {
3397               // The current RedefineClasses() call has made all EMCP
3398               // versions of this method obsolete so mark it as obsolete
3399               RC_TRACE(0x00000400,
3400                 ("add: %s(%s): flush obsolete method @%d in version @%d",
3401                 m_name->as_C_string(), m_signature->as_C_string(), k, j));
3402 
3403               method->set_is_obsolete();
3404               break;
3405             }
3406           }
3407 
3408           // The previous loop may not find a matching EMCP method, but
3409           // that doesn't mean that we can optimize and not go any
3410           // further back in the PreviousVersion generations. The EMCP
3411           // method for this generation could have already been made obsolete,
3412           // but there still may be an older EMCP method that has not
3413           // been made obsolete.
3414         }
3415 
3416         if (++local_count >= obsolete_method_count) {
3417           // no more obsolete methods so bail out now
3418           break;
3419         }
3420       }
3421     }
3422   }
3423 }
3424 
3425 // Save the scratch_class as the previous version if any of the methods are running.
3426 // The previous_versions are used to set breakpoints in EMCP methods and they are
3427 // also used to clean MethodData links to redefined methods that are no longer running.
3428 void InstanceKlass::add_previous_version(instanceKlassHandle scratch_class,
3429                                          int emcp_method_count) {
3430   assert(Thread::current()->is_VM_thread(),
3431          "only VMThread can add previous versions");
3432 
3433   // RC_TRACE macro has an embedded ResourceMark
3434   RC_TRACE(0x00000400, ("adding previous version ref for %s, EMCP_cnt=%d",
3435     scratch_class->external_name(), emcp_method_count));
3436 
3437   // Clean out old previous versions
3438   purge_previous_versions(this);
3439 
3440   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
3441   // a previous redefinition may be made obsolete by this redefinition.
3442   Array<Method*>* old_methods = scratch_class->methods();
3443   mark_newly_obsolete_methods(old_methods, emcp_method_count);
3444 
3445   // If the constant pool for this previous version of the class
3446   // is not marked as being on the stack, then none of the methods
3447   // in this previous version of the class are on the stack so
3448   // we don't need to add this as a previous version.
3449   ConstantPool* cp_ref = scratch_class->constants();
3450   if (!cp_ref->on_stack()) {
3451     RC_TRACE(0x00000400, ("add: scratch class not added; no methods are running"));
3452     // For debugging purposes.
3453     scratch_class->set_is_scratch_class();
3454     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class());
3455     // Update count for class unloading.
3456     _previous_version_count--;
3457     return;
3458   }
3459 
3460   if (emcp_method_count != 0) {
3461     // At least one method is still running, check for EMCP methods
3462     for (int i = 0; i < old_methods->length(); i++) {
3463       Method* old_method = old_methods->at(i);
3464       if (!old_method->is_obsolete() && old_method->on_stack()) {
3465         // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3466         // we can add breakpoints for it.
3467 
3468         // We set the method->on_stack bit during safepoints for class redefinition
3469         // and use this bit to set the is_running_emcp bit.
3470         // After the safepoint, the on_stack bit is cleared and the running emcp
3471         // method may exit.   If so, we would set a breakpoint in a method that
3472         // is never reached, but this won't be noticeable to the programmer.
3473         old_method->set_running_emcp(true);
3474         RC_TRACE(0x00000400, ("add: EMCP method %s is on_stack " INTPTR_FORMAT,
3475                               old_method->name_and_sig_as_C_string(), old_method));
3476       } else if (!old_method->is_obsolete()) {
3477         RC_TRACE(0x00000400, ("add: EMCP method %s is NOT on_stack " INTPTR_FORMAT,
3478                               old_method->name_and_sig_as_C_string(), old_method));
3479       }
3480     }
3481   }
3482 
3483   // Add previous version if any methods are still running.
3484   RC_TRACE(0x00000400, ("add: scratch class added; one of its methods is on_stack"));
3485   assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3486   scratch_class->link_previous_versions(previous_versions());
3487   link_previous_versions(scratch_class());
3488   // Update count for class unloading.
3489   _previous_version_count++;
3490 } // end add_previous_version()
3491 
3492 
3493 Method* InstanceKlass::method_with_idnum(int idnum) {
3494   Method* m = NULL;
3495   if (idnum < methods()->length()) {
3496     m = methods()->at(idnum);
3497   }
3498   if (m == NULL || m->method_idnum() != idnum) {
3499     for (int index = 0; index < methods()->length(); ++index) {
3500       m = methods()->at(index);
3501       if (m->method_idnum() == idnum) {
3502         return m;
3503       }
3504     }
3505     // None found, return null for the caller to handle.
3506     return NULL;
3507   }
3508   return m;
3509 }
3510 
3511 
3512 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3513   if (idnum >= methods()->length()) {
3514     return NULL;
3515   }
3516   Method* m = methods()->at(idnum);
3517   if (m != NULL && m->orig_method_idnum() == idnum) {
3518     return m;
3519   }
3520   // Obsolete method idnum does not match the original idnum
3521   for (int index = 0; index < methods()->length(); ++index) {
3522     m = methods()->at(index);
3523     if (m->orig_method_idnum() == idnum) {
3524       return m;
3525     }
3526   }
3527   // None found, return null for the caller to handle.
3528   return NULL;
3529 }
3530 
3531 
3532 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3533   InstanceKlass* holder = get_klass_version(version);
3534   if (holder == NULL) {
3535     return NULL; // The version of klass is gone, no method is found
3536   }
3537   Method* method = holder->method_with_orig_idnum(idnum);
3538   return method;
3539 }
3540 
3541 
3542 jint InstanceKlass::get_cached_class_file_len() {
3543   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3544 }
3545 
3546 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3547   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3548 }