1 /*
   2  * Copyright (c) 1997, 2019, 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 "jvm.h"
  27 #include "aot/aotLoader.hpp"
  28 #include "classfile/classFileParser.hpp"
  29 #include "classfile/classFileStream.hpp"
  30 #include "classfile/classLoader.hpp"
  31 #include "classfile/classLoaderData.inline.hpp"
  32 #include "classfile/javaClasses.hpp"
  33 #include "classfile/moduleEntry.hpp"
  34 #include "classfile/symbolTable.hpp"
  35 #include "classfile/systemDictionary.hpp"
  36 #include "classfile/systemDictionaryShared.hpp"
  37 #include "classfile/verifier.hpp"
  38 #include "classfile/vmSymbols.hpp"
  39 #include "code/dependencyContext.hpp"
  40 #include "compiler/compileBroker.hpp"
  41 #include "gc/shared/collectedHeap.inline.hpp"
  42 #include "interpreter/oopMapCache.hpp"
  43 #include "interpreter/rewriter.hpp"
  44 #include "jvmtifiles/jvmti.h"
  45 #include "logging/log.hpp"
  46 #include "logging/logMessage.hpp"
  47 #include "logging/logStream.hpp"
  48 #include "memory/allocation.inline.hpp"
  49 #include "memory/heapInspection.hpp"
  50 #include "memory/iterator.inline.hpp"
  51 #include "memory/metadataFactory.hpp"
  52 #include "memory/metaspaceClosure.hpp"
  53 #include "memory/metaspaceShared.hpp"
  54 #include "memory/oopFactory.hpp"
  55 #include "memory/resourceArea.hpp"
  56 #include "memory/universe.hpp"
  57 #include "oops/fieldStreams.hpp"
  58 #include "oops/constantPool.hpp"
  59 #include "oops/instanceClassLoaderKlass.hpp"
  60 #include "oops/instanceKlass.inline.hpp"
  61 #include "oops/instanceMirrorKlass.hpp"
  62 #include "oops/instanceOop.hpp"
  63 #include "oops/klass.inline.hpp"
  64 #include "oops/method.hpp"
  65 #include "oops/oop.inline.hpp"
  66 #include "oops/symbol.hpp"
  67 #include "prims/jvmtiExport.hpp"
  68 #include "prims/jvmtiRedefineClasses.hpp"
  69 #include "prims/jvmtiThreadState.hpp"
  70 #include "prims/methodComparator.hpp"
  71 #include "runtime/atomic.hpp"
  72 #include "runtime/fieldDescriptor.inline.hpp"
  73 #include "runtime/handles.inline.hpp"
  74 #include "runtime/javaCalls.hpp"
  75 #include "runtime/mutexLocker.hpp"
  76 #include "runtime/orderAccess.hpp"
  77 #include "runtime/thread.inline.hpp"
  78 #include "services/classLoadingService.hpp"
  79 #include "services/threadService.hpp"
  80 #include "utilities/dtrace.hpp"
  81 #include "utilities/events.hpp"
  82 #include "utilities/macros.hpp"
  83 #include "utilities/stringUtils.hpp"
  84 #ifdef COMPILER1
  85 #include "c1/c1_Compiler.hpp"
  86 #endif
  87 #if INCLUDE_JFR
  88 #include "jfr/jfrEvents.hpp"
  89 #endif
  90 
  91 
  92 #ifdef DTRACE_ENABLED
  93 
  94 
  95 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
  96 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
  97 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
  98 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
  99 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
 100 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
 101 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
 102 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
 103 #define DTRACE_CLASSINIT_PROBE(type, thread_type)                \
 104   {                                                              \
 105     char* data = NULL;                                           \
 106     int len = 0;                                                 \
 107     Symbol* clss_name = name();                                  \
 108     if (clss_name != NULL) {                                     \
 109       data = (char*)clss_name->bytes();                          \
 110       len = clss_name->utf8_length();                            \
 111     }                                                            \
 112     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 113       data, len, (void*)class_loader(), thread_type);            \
 114   }
 115 
 116 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)     \
 117   {                                                              \
 118     char* data = NULL;                                           \
 119     int len = 0;                                                 \
 120     Symbol* clss_name = name();                                  \
 121     if (clss_name != NULL) {                                     \
 122       data = (char*)clss_name->bytes();                          \
 123       len = clss_name->utf8_length();                            \
 124     }                                                            \
 125     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 126       data, len, (void*)class_loader(), thread_type, wait);      \
 127   }
 128 
 129 #else //  ndef DTRACE_ENABLED
 130 
 131 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
 132 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
 133 
 134 #endif //  ndef DTRACE_ENABLED
 135 
 136 static inline bool is_class_loader(const Symbol* class_name,
 137                                    const ClassFileParser& parser) {
 138   assert(class_name != NULL, "invariant");
 139 
 140   if (class_name == vmSymbols::java_lang_ClassLoader()) {
 141     return true;
 142   }
 143 
 144   if (SystemDictionary::ClassLoader_klass_loaded()) {
 145     const Klass* const super_klass = parser.super_klass();
 146     if (super_klass != NULL) {
 147       if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
 148         return true;
 149       }
 150     }
 151   }
 152   return false;
 153 }
 154 
 155 // called to verify that k is a member of this nest
 156 bool InstanceKlass::has_nest_member(InstanceKlass* k, TRAPS) const {
 157   if (_nest_members == NULL || _nest_members == Universe::the_empty_short_array()) {
 158     if (log_is_enabled(Trace, class, nestmates)) {
 159       ResourceMark rm(THREAD);
 160       log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
 161                                   k->external_name(), this->external_name());
 162     }
 163     return false;
 164   }
 165 
 166   if (log_is_enabled(Trace, class, nestmates)) {
 167     ResourceMark rm(THREAD);
 168     log_trace(class, nestmates)("Checking nest membership of %s in %s",
 169                                 k->external_name(), this->external_name());
 170   }
 171 
 172   // Check for a resolved cp entry , else fall back to a name check.
 173   // We don't want to resolve any class other than the one being checked.
 174   for (int i = 0; i < _nest_members->length(); i++) {
 175     int cp_index = _nest_members->at(i);
 176     if (_constants->tag_at(cp_index).is_klass()) {
 177       Klass* k2 = _constants->klass_at(cp_index, CHECK_false);
 178       if (k2 == k) {
 179         log_trace(class, nestmates)("- class is listed at nest_members[%d] => cp[%d]", i, cp_index);
 180         return true;
 181       }
 182     }
 183     else {
 184       Symbol* name = _constants->klass_name_at(cp_index);
 185       if (name == k->name()) {
 186         log_trace(class, nestmates)("- Found it at nest_members[%d] => cp[%d]", i, cp_index);
 187 
 188         // Names match so check actual klass - this may trigger class loading if
 189         // it doesn't match (though that should be impossible). But to be safe we
 190         // have to check for a compiler thread executing here.
 191         if (!THREAD->can_call_java() && !_constants->tag_at(cp_index).is_klass()) {
 192           log_trace(class, nestmates)("- validation required resolution in an unsuitable thread");
 193           return false;
 194         }
 195 
 196         Klass* k2 = _constants->klass_at(cp_index, CHECK_false);
 197         if (k2 == k) {
 198           log_trace(class, nestmates)("- class is listed as a nest member");
 199           return true;
 200         }
 201         else {
 202           // same name but different klass!
 203           log_trace(class, nestmates)(" - klass comparison failed!");
 204           // can't have two names the same, so we're done
 205           return false;
 206         }
 207       }
 208     }
 209   }
 210   log_trace(class, nestmates)("- class is NOT a nest member!");
 211   return false;
 212 }
 213 
 214 // Return nest-host class, resolving, validating and saving it if needed.
 215 // In cases where this is called from a thread that can not do classloading
 216 // (such as a native JIT thread) then we simply return NULL, which in turn
 217 // causes the access check to return false. Such code will retry the access
 218 // from a more suitable environment later.
 219 InstanceKlass* InstanceKlass::nest_host(Symbol* validationException, TRAPS) {
 220   InstanceKlass* nest_host_k = _nest_host;
 221   if (nest_host_k == NULL) {
 222     // need to resolve and save our nest-host class. This could be attempted
 223     // concurrently but as the result is idempotent and we don't use the class
 224     // then we do not need any synchronization beyond what is implicitly used
 225     // during class loading.
 226     if (_nest_host_index != 0) { // we have a real nest_host
 227       // Before trying to resolve check if we're in a suitable context
 228       if (!THREAD->can_call_java() && !_constants->tag_at(_nest_host_index).is_klass()) {
 229         if (log_is_enabled(Trace, class, nestmates)) {
 230           ResourceMark rm(THREAD);
 231           log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
 232                                       this->external_name());
 233         }
 234         return NULL;
 235       }
 236 
 237       if (log_is_enabled(Trace, class, nestmates)) {
 238         ResourceMark rm(THREAD);
 239         log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
 240                                     this->external_name(),
 241                                     _constants->klass_name_at(_nest_host_index)->as_C_string());
 242       }
 243 
 244       Klass* k = _constants->klass_at(_nest_host_index, THREAD);
 245       if (HAS_PENDING_EXCEPTION) {
 246         Handle exc_h = Handle(THREAD, PENDING_EXCEPTION);
 247         if (exc_h->is_a(SystemDictionary::NoClassDefFoundError_klass())) {
 248           // throw a new CDNFE with the original as its cause, and a clear msg
 249           ResourceMark rm(THREAD);
 250           char buf[200];
 251           CLEAR_PENDING_EXCEPTION;
 252           jio_snprintf(buf, sizeof(buf),
 253                        "Unable to load nest-host class (%s) of %s",
 254                        _constants->klass_name_at(_nest_host_index)->as_C_string(),
 255                        this->external_name());
 256           log_trace(class, nestmates)("%s - NoClassDefFoundError", buf);
 257           THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), buf, exc_h);
 258         }
 259         // All other exceptions pass through (OOME, StackOverflowError, LinkageErrors etc).
 260         return NULL;
 261       }
 262 
 263       // A valid nest-host is an instance class in the current package that lists this
 264       // class as a nest member. If any of these conditions are not met we post the
 265       // requested exception type (if any) and return NULL
 266 
 267       const char* error = NULL;
 268 
 269       // JVMS 5.4.4 indicates package check comes first
 270       if (is_same_class_package(k)) {
 271 
 272         // Now check actual membership. We can't be a member if our "host" is
 273         // not an instance class.
 274         if (k->is_instance_klass()) {
 275           nest_host_k = InstanceKlass::cast(k);
 276 
 277           bool is_member = nest_host_k->has_nest_member(this, CHECK_NULL);
 278           if (is_member) {
 279             // save resolved nest-host value
 280             _nest_host = nest_host_k;
 281 
 282             if (log_is_enabled(Trace, class, nestmates)) {
 283               ResourceMark rm(THREAD);
 284               log_trace(class, nestmates)("Resolved nest-host of %s to %s",
 285                                           this->external_name(), k->external_name());
 286             }
 287             return nest_host_k;
 288           }
 289         }
 290         error = "current type is not listed as a nest member";
 291       } else {
 292         error = "types are in different packages";
 293       }
 294 
 295       if (log_is_enabled(Trace, class, nestmates)) {
 296         ResourceMark rm(THREAD);
 297         log_trace(class, nestmates)
 298           ("Type %s (loader: %s) is not a nest member of "
 299            "resolved type %s (loader: %s): %s",
 300            this->external_name(),
 301            this->class_loader_data()->loader_name_and_id(),
 302            k->external_name(),
 303            k->class_loader_data()->loader_name_and_id(),
 304            error);
 305       }
 306 
 307       if (validationException != NULL && THREAD->can_call_java()) {
 308         ResourceMark rm(THREAD);
 309         Exceptions::fthrow(THREAD_AND_LOCATION,
 310                            validationException,
 311                            "Type %s (loader: %s) is not a nest member of %s (loader: %s): %s",
 312                            this->external_name(),
 313                            this->class_loader_data()->loader_name_and_id(),
 314                            k->external_name(),
 315                            k->class_loader_data()->loader_name_and_id(),
 316                            error
 317                            );
 318       }
 319       return NULL;
 320     } else {
 321       if (log_is_enabled(Trace, class, nestmates)) {
 322         ResourceMark rm(THREAD);
 323         log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
 324                                     this->external_name());
 325       }
 326       // save resolved nest-host value
 327       return (_nest_host = this);
 328     }
 329   }
 330   return nest_host_k;
 331 }
 332 
 333 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
 334 // or we are k's nest_host - all of which is covered by comparing the two
 335 // resolved_nest_hosts
 336 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
 337 
 338   assert(this != k, "this should be handled by higher-level code");
 339 
 340   // Per JVMS 5.4.4 we first resolve and validate the current class, then
 341   // the target class k. Resolution exceptions will be passed on by upper
 342   // layers. IncompatibleClassChangeErrors from membership validation failures
 343   // will also be passed through.
 344 
 345   Symbol* icce = vmSymbols::java_lang_IncompatibleClassChangeError();
 346   InstanceKlass* cur_host = nest_host(icce, CHECK_false);
 347   if (cur_host == NULL) {
 348     return false;
 349   }
 350 
 351   Klass* k_nest_host = k->nest_host(icce, CHECK_false);
 352   if (k_nest_host == NULL) {
 353     return false;
 354   }
 355 
 356   bool access = (cur_host == k_nest_host);
 357 
 358   if (log_is_enabled(Trace, class, nestmates)) {
 359     ResourceMark rm(THREAD);
 360     log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
 361                                 this->external_name(),
 362                                 access ? "" : "NOT ",
 363                                 k->external_name());
 364   }
 365 
 366   return access;
 367 }
 368 
 369 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
 370   const int size = InstanceKlass::size(parser.vtable_size(),
 371                                        parser.itable_size(),
 372                                        nonstatic_oop_map_size(parser.total_oop_map_count()),
 373                                        parser.is_interface(),
 374                                        parser.is_unsafe_anonymous(),
 375                                        should_store_fingerprint(parser.is_unsafe_anonymous()));
 376 
 377   const Symbol* const class_name = parser.class_name();
 378   assert(class_name != NULL, "invariant");
 379   ClassLoaderData* loader_data = parser.loader_data();
 380   assert(loader_data != NULL, "invariant");
 381 
 382   InstanceKlass* ik;
 383 
 384   // Allocation
 385   if (REF_NONE == parser.reference_type()) {
 386     if (class_name == vmSymbols::java_lang_Class()) {
 387       // mirror
 388       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
 389     }
 390     else if (is_class_loader(class_name, parser)) {
 391       // class loader
 392       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
 393     } else {
 394       // normal
 395       ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
 396     }
 397   } else {
 398     // reference
 399     ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
 400   }
 401 
 402   // Check for pending exception before adding to the loader data and incrementing
 403   // class count.  Can get OOM here.
 404   if (HAS_PENDING_EXCEPTION) {
 405     return NULL;
 406   }
 407 
 408   return ik;
 409 }
 410 
 411 
 412 // copy method ordering from resource area to Metaspace
 413 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
 414   if (m != NULL) {
 415     // allocate a new array and copy contents (memcpy?)
 416     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
 417     for (int i = 0; i < m->length(); i++) {
 418       _method_ordering->at_put(i, m->at(i));
 419     }
 420   } else {
 421     _method_ordering = Universe::the_empty_int_array();
 422   }
 423 }
 424 
 425 // create a new array of vtable_indices for default methods
 426 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
 427   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
 428   assert(default_vtable_indices() == NULL, "only create once");
 429   set_default_vtable_indices(vtable_indices);
 430   return vtable_indices;
 431 }
 432 
 433 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind, KlassID id) :
 434   Klass(id),
 435   _nest_members(NULL),
 436   _nest_host_index(0),
 437   _nest_host(NULL),
 438   _record_components(NULL),
 439   _static_field_size(parser.static_field_size()),
 440   _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
 441   _itable_len(parser.itable_size()),
 442   _init_thread(NULL),
 443   _init_state(allocated),
 444   _reference_type(parser.reference_type())
 445 {
 446   set_vtable_length(parser.vtable_size());
 447   set_kind(kind);
 448   set_access_flags(parser.access_flags());
 449   set_is_unsafe_anonymous(parser.is_unsafe_anonymous());
 450   set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
 451                                                     false));
 452 
 453   assert(NULL == _methods, "underlying memory not zeroed?");
 454   assert(is_instance_klass(), "is layout incorrect?");
 455   assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
 456 
 457   if (Arguments::is_dumping_archive()) {
 458     SystemDictionaryShared::init_dumptime_info(this);
 459   }
 460 }
 461 
 462 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 463                                        Array<Method*>* methods) {
 464   if (methods != NULL && methods != Universe::the_empty_method_array() &&
 465       !methods->is_shared()) {
 466     for (int i = 0; i < methods->length(); i++) {
 467       Method* method = methods->at(i);
 468       if (method == NULL) continue;  // maybe null if error processing
 469       // Only want to delete methods that are not executing for RedefineClasses.
 470       // The previous version will point to them so they're not totally dangling
 471       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 472       MetadataFactory::free_metadata(loader_data, method);
 473     }
 474     MetadataFactory::free_array<Method*>(loader_data, methods);
 475   }
 476 }
 477 
 478 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 479                                           const Klass* super_klass,
 480                                           Array<InstanceKlass*>* local_interfaces,
 481                                           Array<InstanceKlass*>* transitive_interfaces) {
 482   // Only deallocate transitive interfaces if not empty, same as super class
 483   // or same as local interfaces.  See code in parseClassFile.
 484   Array<InstanceKlass*>* ti = transitive_interfaces;
 485   if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
 486     // check that the interfaces don't come from super class
 487     Array<InstanceKlass*>* sti = (super_klass == NULL) ? NULL :
 488                     InstanceKlass::cast(super_klass)->transitive_interfaces();
 489     if (ti != sti && ti != NULL && !ti->is_shared()) {
 490       MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
 491     }
 492   }
 493 
 494   // local interfaces can be empty
 495   if (local_interfaces != Universe::the_empty_instance_klass_array() &&
 496       local_interfaces != NULL && !local_interfaces->is_shared()) {
 497     MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
 498   }
 499 }
 500 
 501 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
 502                                                  Array<RecordComponent*>* record_components) {
 503   if (record_components != NULL && !record_components->is_shared()) {
 504     for (int i = 0; i < record_components->length(); i++) {
 505       RecordComponent* record_component = record_components->at(i);
 506       MetadataFactory::free_metadata(loader_data, record_component);
 507     }
 508     MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
 509   }
 510 }
 511 
 512 // This function deallocates the metadata and C heap pointers that the
 513 // InstanceKlass points to.
 514 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 515 
 516   // Orphan the mirror first, CMS thinks it's still live.
 517   if (java_mirror() != NULL) {
 518     java_lang_Class::set_klass(java_mirror(), NULL);
 519   }
 520 
 521   // Also remove mirror from handles
 522   loader_data->remove_handle(_java_mirror);
 523 
 524   // Need to take this class off the class loader data list.
 525   loader_data->remove_class(this);
 526 
 527   // The array_klass for this class is created later, after error handling.
 528   // For class redefinition, we keep the original class so this scratch class
 529   // doesn't have an array class.  Either way, assert that there is nothing
 530   // to deallocate.
 531   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
 532 
 533   // Release C heap allocated data that this might point to, which includes
 534   // reference counting symbol names.
 535   release_C_heap_structures();
 536 
 537   deallocate_methods(loader_data, methods());
 538   set_methods(NULL);
 539 
 540   deallocate_record_components(loader_data, record_components());
 541   set_record_components(NULL);
 542 
 543   if (method_ordering() != NULL &&
 544       method_ordering() != Universe::the_empty_int_array() &&
 545       !method_ordering()->is_shared()) {
 546     MetadataFactory::free_array<int>(loader_data, method_ordering());
 547   }
 548   set_method_ordering(NULL);
 549 
 550   // default methods can be empty
 551   if (default_methods() != NULL &&
 552       default_methods() != Universe::the_empty_method_array() &&
 553       !default_methods()->is_shared()) {
 554     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 555   }
 556   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 557   set_default_methods(NULL);
 558 
 559   // default methods vtable indices can be empty
 560   if (default_vtable_indices() != NULL &&
 561       !default_vtable_indices()->is_shared()) {
 562     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 563   }
 564   set_default_vtable_indices(NULL);
 565 
 566 
 567   // This array is in Klass, but remove it with the InstanceKlass since
 568   // this place would be the only caller and it can share memory with transitive
 569   // interfaces.
 570   if (secondary_supers() != NULL &&
 571       secondary_supers() != Universe::the_empty_klass_array() &&
 572       // see comments in compute_secondary_supers about the following cast
 573       (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
 574       !secondary_supers()->is_shared()) {
 575     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 576   }
 577   set_secondary_supers(NULL);
 578 
 579   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 580   set_transitive_interfaces(NULL);
 581   set_local_interfaces(NULL);
 582 
 583   if (fields() != NULL && !fields()->is_shared()) {
 584     MetadataFactory::free_array<jushort>(loader_data, fields());
 585   }
 586   set_fields(NULL, 0);
 587 
 588   // If a method from a redefined class is using this constant pool, don't
 589   // delete it, yet.  The new class's previous version will point to this.
 590   if (constants() != NULL) {
 591     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 592     if (!constants()->is_shared()) {
 593       MetadataFactory::free_metadata(loader_data, constants());
 594     }
 595     // Delete any cached resolution errors for the constant pool
 596     SystemDictionary::delete_resolution_error(constants());
 597 
 598     set_constants(NULL);
 599   }
 600 
 601   if (inner_classes() != NULL &&
 602       inner_classes() != Universe::the_empty_short_array() &&
 603       !inner_classes()->is_shared()) {
 604     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 605   }
 606   set_inner_classes(NULL);
 607 
 608   if (nest_members() != NULL &&
 609       nest_members() != Universe::the_empty_short_array() &&
 610       !nest_members()->is_shared()) {
 611     MetadataFactory::free_array<jushort>(loader_data, nest_members());
 612   }
 613   set_nest_members(NULL);
 614 
 615   // We should deallocate the Annotations instance if it's not in shared spaces.
 616   if (annotations() != NULL && !annotations()->is_shared()) {
 617     MetadataFactory::free_metadata(loader_data, annotations());
 618   }
 619   set_annotations(NULL);
 620 
 621   if (Arguments::is_dumping_archive()) {
 622     SystemDictionaryShared::remove_dumptime_info(this);
 623   }
 624 }
 625 
 626 bool InstanceKlass::should_be_initialized() const {
 627   return !is_initialized();
 628 }
 629 
 630 klassItable InstanceKlass::itable() const {
 631   return klassItable(const_cast<InstanceKlass*>(this));
 632 }
 633 
 634 void InstanceKlass::eager_initialize(Thread *thread) {
 635   if (!EagerInitialization) return;
 636 
 637   if (this->is_not_initialized()) {
 638     // abort if the the class has a class initializer
 639     if (this->class_initializer() != NULL) return;
 640 
 641     // abort if it is java.lang.Object (initialization is handled in genesis)
 642     Klass* super_klass = super();
 643     if (super_klass == NULL) return;
 644 
 645     // abort if the super class should be initialized
 646     if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
 647 
 648     // call body to expose the this pointer
 649     eager_initialize_impl();
 650   }
 651 }
 652 
 653 // JVMTI spec thinks there are signers and protection domain in the
 654 // instanceKlass.  These accessors pretend these fields are there.
 655 // The hprof specification also thinks these fields are in InstanceKlass.
 656 oop InstanceKlass::protection_domain() const {
 657   // return the protection_domain from the mirror
 658   return java_lang_Class::protection_domain(java_mirror());
 659 }
 660 
 661 // To remove these from requires an incompatible change and CCC request.
 662 objArrayOop InstanceKlass::signers() const {
 663   // return the signers from the mirror
 664   return java_lang_Class::signers(java_mirror());
 665 }
 666 
 667 oop InstanceKlass::init_lock() const {
 668   // return the init lock from the mirror
 669   oop lock = java_lang_Class::init_lock(java_mirror());
 670   // Prevent reordering with any access of initialization state
 671   OrderAccess::loadload();
 672   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
 673          "only fully initialized state can have a null lock");
 674   return lock;
 675 }
 676 
 677 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 678 // threads to get this lock will see a null lock and will not lock.
 679 // That's okay because they all check for initialized state after getting
 680 // the lock and return.
 681 void InstanceKlass::fence_and_clear_init_lock() {
 682   // make sure previous stores are all done, notably the init_state.
 683   OrderAccess::storestore();
 684   java_lang_Class::set_init_lock(java_mirror(), NULL);
 685   assert(!is_not_initialized(), "class must be initialized now");
 686 }
 687 
 688 void InstanceKlass::eager_initialize_impl() {
 689   EXCEPTION_MARK;
 690   HandleMark hm(THREAD);
 691   Handle h_init_lock(THREAD, init_lock());
 692   ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 693 
 694   // abort if someone beat us to the initialization
 695   if (!is_not_initialized()) return;  // note: not equivalent to is_initialized()
 696 
 697   ClassState old_state = init_state();
 698   link_class_impl(THREAD);
 699   if (HAS_PENDING_EXCEPTION) {
 700     CLEAR_PENDING_EXCEPTION;
 701     // Abort if linking the class throws an exception.
 702 
 703     // Use a test to avoid redundantly resetting the state if there's
 704     // no change.  Set_init_state() asserts that state changes make
 705     // progress, whereas here we might just be spinning in place.
 706     if (old_state != _init_state)
 707       set_init_state(old_state);
 708   } else {
 709     // linking successfull, mark class as initialized
 710     set_init_state(fully_initialized);
 711     fence_and_clear_init_lock();
 712     // trace
 713     if (log_is_enabled(Info, class, init)) {
 714       ResourceMark rm(THREAD);
 715       log_info(class, init)("[Initialized %s without side effects]", external_name());
 716     }
 717   }
 718 }
 719 
 720 
 721 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 722 // process. The step comments refers to the procedure described in that section.
 723 // Note: implementation moved to static method to expose the this pointer.
 724 void InstanceKlass::initialize(TRAPS) {
 725   if (this->should_be_initialized()) {
 726     initialize_impl(CHECK);
 727     // Note: at this point the class may be initialized
 728     //       OR it may be in the state of being initialized
 729     //       in case of recursive initialization!
 730   } else {
 731     assert(is_initialized(), "sanity check");
 732   }
 733 }
 734 
 735 
 736 bool InstanceKlass::verify_code(TRAPS) {
 737   // 1) Verify the bytecodes
 738   return Verifier::verify(this, should_verify_class(), THREAD);
 739 }
 740 
 741 void InstanceKlass::link_class(TRAPS) {
 742   assert(is_loaded(), "must be loaded");
 743   if (!is_linked()) {
 744     link_class_impl(CHECK);
 745   }
 746 }
 747 
 748 // Called to verify that a class can link during initialization, without
 749 // throwing a VerifyError.
 750 bool InstanceKlass::link_class_or_fail(TRAPS) {
 751   assert(is_loaded(), "must be loaded");
 752   if (!is_linked()) {
 753     link_class_impl(CHECK_false);
 754   }
 755   return is_linked();
 756 }
 757 
 758 bool InstanceKlass::link_class_impl(TRAPS) {
 759   if (DumpSharedSpaces && is_in_error_state()) {
 760     // This is for CDS dumping phase only -- we use the in_error_state to indicate that
 761     // the class has failed verification. Throwing the NoClassDefFoundError here is just
 762     // a convenient way to stop repeat attempts to verify the same (bad) class.
 763     //
 764     // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
 765     // if we are executing Java code. This is not a problem for CDS dumping phase since
 766     // it doesn't execute any Java code.
 767     ResourceMark rm(THREAD);
 768     Exceptions::fthrow(THREAD_AND_LOCATION,
 769                        vmSymbols::java_lang_NoClassDefFoundError(),
 770                        "Class %s, or one of its supertypes, failed class initialization",
 771                        external_name());
 772     return false;
 773   }
 774   // return if already verified
 775   if (is_linked()) {
 776     return true;
 777   }
 778 
 779   // Timing
 780   // timer handles recursion
 781   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 782   JavaThread* jt = (JavaThread*)THREAD;
 783 
 784   // link super class before linking this class
 785   Klass* super_klass = super();
 786   if (super_klass != NULL) {
 787     if (super_klass->is_interface()) {  // check if super class is an interface
 788       ResourceMark rm(THREAD);
 789       Exceptions::fthrow(
 790         THREAD_AND_LOCATION,
 791         vmSymbols::java_lang_IncompatibleClassChangeError(),
 792         "class %s has interface %s as super class",
 793         external_name(),
 794         super_klass->external_name()
 795       );
 796       return false;
 797     }
 798 
 799     InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
 800     ik_super->link_class_impl(CHECK_false);
 801   }
 802 
 803   // link all interfaces implemented by this class before linking this class
 804   Array<InstanceKlass*>* interfaces = local_interfaces();
 805   int num_interfaces = interfaces->length();
 806   for (int index = 0; index < num_interfaces; index++) {
 807     InstanceKlass* interk = interfaces->at(index);
 808     interk->link_class_impl(CHECK_false);
 809   }
 810 
 811   // in case the class is linked in the process of linking its superclasses
 812   if (is_linked()) {
 813     return true;
 814   }
 815 
 816   // trace only the link time for this klass that includes
 817   // the verification time
 818   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 819                              ClassLoader::perf_class_link_selftime(),
 820                              ClassLoader::perf_classes_linked(),
 821                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 822                              jt->get_thread_stat()->perf_timers_addr(),
 823                              PerfClassTraceTime::CLASS_LINK);
 824 
 825   // verification & rewriting
 826   {
 827     HandleMark hm(THREAD);
 828     Handle h_init_lock(THREAD, init_lock());
 829     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 830     // rewritten will have been set if loader constraint error found
 831     // on an earlier link attempt
 832     // don't verify or rewrite if already rewritten
 833     //
 834 
 835     if (!is_linked()) {
 836       if (!is_rewritten()) {
 837         {
 838           bool verify_ok = verify_code(THREAD);
 839           if (!verify_ok) {
 840             return false;
 841           }
 842         }
 843 
 844         // Just in case a side-effect of verify linked this class already
 845         // (which can sometimes happen since the verifier loads classes
 846         // using custom class loaders, which are free to initialize things)
 847         if (is_linked()) {
 848           return true;
 849         }
 850 
 851         // also sets rewritten
 852         rewrite_class(CHECK_false);
 853       } else if (is_shared()) {
 854         SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
 855       }
 856 
 857       // relocate jsrs and link methods after they are all rewritten
 858       link_methods(CHECK_false);
 859 
 860       // Initialize the vtable and interface table after
 861       // methods have been rewritten since rewrite may
 862       // fabricate new Method*s.
 863       // also does loader constraint checking
 864       //
 865       // initialize_vtable and initialize_itable need to be rerun for
 866       // a shared class if the class is not loaded by the NULL classloader.
 867       ClassLoaderData * loader_data = class_loader_data();
 868       if (!(is_shared() &&
 869             loader_data->is_the_null_class_loader_data())) {
 870         vtable().initialize_vtable(true, CHECK_false);
 871         itable().initialize_itable(true, CHECK_false);
 872       }
 873 #ifdef ASSERT
 874       else {
 875         vtable().verify(tty, true);
 876         // In case itable verification is ever added.
 877         // itable().verify(tty, true);
 878       }
 879 #endif
 880       set_init_state(linked);
 881       if (JvmtiExport::should_post_class_prepare()) {
 882         Thread *thread = THREAD;
 883         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 884         JvmtiExport::post_class_prepare((JavaThread *) thread, this);
 885       }
 886     }
 887   }
 888   return true;
 889 }
 890 
 891 // Rewrite the byte codes of all of the methods of a class.
 892 // The rewriter must be called exactly once. Rewriting must happen after
 893 // verification but before the first method of the class is executed.
 894 void InstanceKlass::rewrite_class(TRAPS) {
 895   assert(is_loaded(), "must be loaded");
 896   if (is_rewritten()) {
 897     assert(is_shared(), "rewriting an unshared class?");
 898     return;
 899   }
 900   Rewriter::rewrite(this, CHECK);
 901   set_rewritten();
 902 }
 903 
 904 // Now relocate and link method entry points after class is rewritten.
 905 // This is outside is_rewritten flag. In case of an exception, it can be
 906 // executed more than once.
 907 void InstanceKlass::link_methods(TRAPS) {
 908   int len = methods()->length();
 909   for (int i = len-1; i >= 0; i--) {
 910     methodHandle m(THREAD, methods()->at(i));
 911 
 912     // Set up method entry points for compiler and interpreter    .
 913     m->link_method(m, CHECK);
 914   }
 915 }
 916 
 917 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
 918 void InstanceKlass::initialize_super_interfaces(TRAPS) {
 919   assert (has_nonstatic_concrete_methods(), "caller should have checked this");
 920   for (int i = 0; i < local_interfaces()->length(); ++i) {
 921     InstanceKlass* ik = local_interfaces()->at(i);
 922 
 923     // Initialization is depth first search ie. we start with top of the inheritance tree
 924     // has_nonstatic_concrete_methods drives searching superinterfaces since it
 925     // means has_nonstatic_concrete_methods in its superinterface hierarchy
 926     if (ik->has_nonstatic_concrete_methods()) {
 927       ik->initialize_super_interfaces(CHECK);
 928     }
 929 
 930     // Only initialize() interfaces that "declare" concrete methods.
 931     if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
 932       ik->initialize(CHECK);
 933     }
 934   }
 935 }
 936 
 937 void InstanceKlass::initialize_impl(TRAPS) {
 938   HandleMark hm(THREAD);
 939 
 940   // Make sure klass is linked (verified) before initialization
 941   // A class could already be verified, since it has been reflected upon.
 942   link_class(CHECK);
 943 
 944   DTRACE_CLASSINIT_PROBE(required, -1);
 945 
 946   bool wait = false;
 947 
 948   assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
 949   JavaThread* jt = (JavaThread*)THREAD;
 950 
 951   // refer to the JVM book page 47 for description of steps
 952   // Step 1
 953   {
 954     Handle h_init_lock(THREAD, init_lock());
 955     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 956 
 957     // Step 2
 958     // If we were to use wait() instead of waitInterruptibly() then
 959     // we might end up throwing IE from link/symbol resolution sites
 960     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
 961     while (is_being_initialized() && !is_reentrant_initialization(jt)) {
 962       wait = true;
 963       jt->set_class_to_be_initialized(this);
 964       ol.wait_uninterruptibly(jt);
 965       jt->set_class_to_be_initialized(NULL);
 966     }
 967 
 968     // Step 3
 969     if (is_being_initialized() && is_reentrant_initialization(jt)) {
 970       DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
 971       return;
 972     }
 973 
 974     // Step 4
 975     if (is_initialized()) {
 976       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
 977       return;
 978     }
 979 
 980     // Step 5
 981     if (is_in_error_state()) {
 982       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
 983       ResourceMark rm(THREAD);
 984       const char* desc = "Could not initialize class ";
 985       const char* className = external_name();
 986       size_t msglen = strlen(desc) + strlen(className) + 1;
 987       char* message = NEW_RESOURCE_ARRAY(char, msglen);
 988       if (NULL == message) {
 989         // Out of memory: can't create detailed error message
 990           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
 991       } else {
 992         jio_snprintf(message, msglen, "%s%s", desc, className);
 993           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
 994       }
 995     }
 996 
 997     // Step 6
 998     set_init_state(being_initialized);
 999     set_init_thread(jt);
1000   }
1001 
1002   // Step 7
1003   // Next, if C is a class rather than an interface, initialize it's super class and super
1004   // interfaces.
1005   if (!is_interface()) {
1006     Klass* super_klass = super();
1007     if (super_klass != NULL && super_klass->should_be_initialized()) {
1008       super_klass->initialize(THREAD);
1009     }
1010     // If C implements any interface that declares a non-static, concrete method,
1011     // the initialization of C triggers initialization of its super interfaces.
1012     // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1013     // having a superinterface that declares, non-static, concrete methods
1014     if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1015       initialize_super_interfaces(THREAD);
1016     }
1017 
1018     // If any exceptions, complete abruptly, throwing the same exception as above.
1019     if (HAS_PENDING_EXCEPTION) {
1020       Handle e(THREAD, PENDING_EXCEPTION);
1021       CLEAR_PENDING_EXCEPTION;
1022       {
1023         EXCEPTION_MARK;
1024         // Locks object, set state, and notify all waiting threads
1025         set_initialization_state_and_notify(initialization_error, THREAD);
1026         CLEAR_PENDING_EXCEPTION;
1027       }
1028       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1029       THROW_OOP(e());
1030     }
1031   }
1032 
1033 
1034   // Look for aot compiled methods for this klass, including class initializer.
1035   AOTLoader::load_for_klass(this, THREAD);
1036 
1037   // Step 8
1038   {
1039     DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1040     // Timer includes any side effects of class initialization (resolution,
1041     // etc), but not recursive entry into call_class_initializer().
1042     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1043                              ClassLoader::perf_class_init_selftime(),
1044                              ClassLoader::perf_classes_inited(),
1045                              jt->get_thread_stat()->perf_recursion_counts_addr(),
1046                              jt->get_thread_stat()->perf_timers_addr(),
1047                              PerfClassTraceTime::CLASS_CLINIT);
1048     call_class_initializer(THREAD);
1049   }
1050 
1051   // Step 9
1052   if (!HAS_PENDING_EXCEPTION) {
1053     set_initialization_state_and_notify(fully_initialized, CHECK);
1054     {
1055       debug_only(vtable().verify(tty, true);)
1056     }
1057   }
1058   else {
1059     // Step 10 and 11
1060     Handle e(THREAD, PENDING_EXCEPTION);
1061     CLEAR_PENDING_EXCEPTION;
1062     // JVMTI has already reported the pending exception
1063     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1064     JvmtiExport::clear_detected_exception(jt);
1065     {
1066       EXCEPTION_MARK;
1067       set_initialization_state_and_notify(initialization_error, THREAD);
1068       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
1069       // JVMTI has already reported the pending exception
1070       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1071       JvmtiExport::clear_detected_exception(jt);
1072     }
1073     DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1074     if (e->is_a(SystemDictionary::Error_klass())) {
1075       THROW_OOP(e());
1076     } else {
1077       JavaCallArguments args(e);
1078       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1079                 vmSymbols::throwable_void_signature(),
1080                 &args);
1081     }
1082   }
1083   DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1084 }
1085 
1086 
1087 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1088   Handle h_init_lock(THREAD, init_lock());
1089   if (h_init_lock() != NULL) {
1090     ObjectLocker ol(h_init_lock, THREAD);
1091     set_init_thread(NULL); // reset _init_thread before changing _init_state
1092     set_init_state(state);
1093     fence_and_clear_init_lock();
1094     ol.notify_all(CHECK);
1095   } else {
1096     assert(h_init_lock() != NULL, "The initialization state should never be set twice");
1097     set_init_thread(NULL); // reset _init_thread before changing _init_state
1098     set_init_state(state);
1099   }
1100 }
1101 
1102 Klass* InstanceKlass::implementor() const {
1103   Klass* volatile* k = adr_implementor();
1104   if (k == NULL) {
1105     return NULL;
1106   } else {
1107     // This load races with inserts, and therefore needs acquire.
1108     Klass* kls = OrderAccess::load_acquire(k);
1109     if (kls != NULL && !kls->is_loader_alive()) {
1110       return NULL;  // don't return unloaded class
1111     } else {
1112       return kls;
1113     }
1114   }
1115 }
1116 
1117 
1118 void InstanceKlass::set_implementor(Klass* k) {
1119   assert_locked_or_safepoint(Compile_lock);
1120   assert(is_interface(), "not interface");
1121   Klass* volatile* addr = adr_implementor();
1122   assert(addr != NULL, "null addr");
1123   if (addr != NULL) {
1124     OrderAccess::release_store(addr, k);
1125   }
1126 }
1127 
1128 int  InstanceKlass::nof_implementors() const {
1129   Klass* k = implementor();
1130   if (k == NULL) {
1131     return 0;
1132   } else if (k != this) {
1133     return 1;
1134   } else {
1135     return 2;
1136   }
1137 }
1138 
1139 // The embedded _implementor field can only record one implementor.
1140 // When there are more than one implementors, the _implementor field
1141 // is set to the interface Klass* itself. Following are the possible
1142 // values for the _implementor field:
1143 //   NULL                  - no implementor
1144 //   implementor Klass*    - one implementor
1145 //   self                  - more than one implementor
1146 //
1147 // The _implementor field only exists for interfaces.
1148 void InstanceKlass::add_implementor(Klass* k) {
1149   assert_lock_strong(Compile_lock);
1150   assert(is_interface(), "not interface");
1151   // Filter out my subinterfaces.
1152   // (Note: Interfaces are never on the subklass list.)
1153   if (InstanceKlass::cast(k)->is_interface()) return;
1154 
1155   // Filter out subclasses whose supers already implement me.
1156   // (Note: CHA must walk subclasses of direct implementors
1157   // in order to locate indirect implementors.)
1158   Klass* sk = k->super();
1159   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
1160     // We only need to check one immediate superclass, since the
1161     // implements_interface query looks at transitive_interfaces.
1162     // Any supers of the super have the same (or fewer) transitive_interfaces.
1163     return;
1164 
1165   Klass* ik = implementor();
1166   if (ik == NULL) {
1167     set_implementor(k);
1168   } else if (ik != this) {
1169     // There is already an implementor. Use itself as an indicator of
1170     // more than one implementors.
1171     set_implementor(this);
1172   }
1173 
1174   // The implementor also implements the transitive_interfaces
1175   for (int index = 0; index < local_interfaces()->length(); index++) {
1176     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
1177   }
1178 }
1179 
1180 void InstanceKlass::init_implementor() {
1181   if (is_interface()) {
1182     set_implementor(NULL);
1183   }
1184 }
1185 
1186 
1187 void InstanceKlass::process_interfaces(Thread *thread) {
1188   // link this class into the implementors list of every interface it implements
1189   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1190     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1191     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
1192     assert(interf->is_interface(), "expected interface");
1193     interf->add_implementor(this);
1194   }
1195 }
1196 
1197 bool InstanceKlass::can_be_primary_super_slow() const {
1198   if (is_interface())
1199     return false;
1200   else
1201     return Klass::can_be_primary_super_slow();
1202 }
1203 
1204 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1205                                                                Array<InstanceKlass*>* transitive_interfaces) {
1206   // The secondaries are the implemented interfaces.
1207   Array<InstanceKlass*>* interfaces = transitive_interfaces;
1208   int num_secondaries = num_extra_slots + interfaces->length();
1209   if (num_secondaries == 0) {
1210     // Must share this for correct bootstrapping!
1211     set_secondary_supers(Universe::the_empty_klass_array());
1212     return NULL;
1213   } else if (num_extra_slots == 0) {
1214     // The secondary super list is exactly the same as the transitive interfaces, so
1215     // let's use it instead of making a copy.
1216     // Redefine classes has to be careful not to delete this!
1217     // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1218     // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1219     set_secondary_supers((Array<Klass*>*)(address)interfaces);
1220     return NULL;
1221   } else {
1222     // Copy transitive interfaces to a temporary growable array to be constructed
1223     // into the secondary super list with extra slots.
1224     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1225     for (int i = 0; i < interfaces->length(); i++) {
1226       secondaries->push(interfaces->at(i));
1227     }
1228     return secondaries;
1229   }
1230 }
1231 
1232 bool InstanceKlass::implements_interface(Klass* k) const {
1233   if (this == k) return true;
1234   assert(k->is_interface(), "should be an interface class");
1235   for (int i = 0; i < transitive_interfaces()->length(); i++) {
1236     if (transitive_interfaces()->at(i) == k) {
1237       return true;
1238     }
1239   }
1240   return false;
1241 }
1242 
1243 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1244   // Verify direct super interface
1245   if (this == k) return true;
1246   assert(k->is_interface(), "should be an interface class");
1247   for (int i = 0; i < local_interfaces()->length(); i++) {
1248     if (local_interfaces()->at(i) == k) {
1249       return true;
1250     }
1251   }
1252   return false;
1253 }
1254 
1255 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1256   check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1257   int size = objArrayOopDesc::object_size(length);
1258   Klass* ak = array_klass(n, CHECK_NULL);
1259   objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1260                                                                 /* do_zero */ true, CHECK_NULL);
1261   return o;
1262 }
1263 
1264 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1265   if (TraceFinalizerRegistration) {
1266     tty->print("Registered ");
1267     i->print_value_on(tty);
1268     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1269   }
1270   instanceHandle h_i(THREAD, i);
1271   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1272   JavaValue result(T_VOID);
1273   JavaCallArguments args(h_i);
1274   methodHandle mh (THREAD, Universe::finalizer_register_method());
1275   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1276   return h_i();
1277 }
1278 
1279 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1280   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1281   int size = size_helper();  // Query before forming handle.
1282 
1283   instanceOop i;
1284 
1285   i = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1286   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1287     i = register_finalizer(i, CHECK_NULL);
1288   }
1289   return i;
1290 }
1291 
1292 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1293   return instanceHandle(THREAD, allocate_instance(THREAD));
1294 }
1295 
1296 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1297   if (is_interface() || is_abstract()) {
1298     ResourceMark rm(THREAD);
1299     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1300               : vmSymbols::java_lang_InstantiationException(), external_name());
1301   }
1302   if (this == SystemDictionary::Class_klass()) {
1303     ResourceMark rm(THREAD);
1304     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1305               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1306   }
1307 }
1308 
1309 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1310   // Need load-acquire for lock-free read
1311   if (array_klasses_acquire() == NULL) {
1312     if (or_null) return NULL;
1313 
1314     ResourceMark rm;
1315     JavaThread *jt = (JavaThread *)THREAD;
1316     {
1317       // Atomic creation of array_klasses
1318       MutexLocker ma(MultiArray_lock, THREAD);
1319 
1320       // Check if update has already taken place
1321       if (array_klasses() == NULL) {
1322         Klass*    k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1323         // use 'release' to pair with lock-free load
1324         release_set_array_klasses(k);
1325       }
1326     }
1327   }
1328   // _this will always be set at this point
1329   ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1330   if (or_null) {
1331     return oak->array_klass_or_null(n);
1332   }
1333   return oak->array_klass(n, THREAD);
1334 }
1335 
1336 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1337   return array_klass_impl(or_null, 1, THREAD);
1338 }
1339 
1340 static int call_class_initializer_counter = 0;   // for debugging
1341 
1342 Method* InstanceKlass::class_initializer() const {
1343   Method* clinit = find_method(
1344       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1345   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1346     return clinit;
1347   }
1348   return NULL;
1349 }
1350 
1351 void InstanceKlass::call_class_initializer(TRAPS) {
1352   if (ReplayCompiles &&
1353       (ReplaySuppressInitializers == 1 ||
1354        (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1355     // Hide the existence of the initializer for the purpose of replaying the compile
1356     return;
1357   }
1358 
1359   methodHandle h_method(THREAD, class_initializer());
1360   assert(!is_initialized(), "we cannot initialize twice");
1361   LogTarget(Info, class, init) lt;
1362   if (lt.is_enabled()) {
1363     ResourceMark rm;
1364     LogStream ls(lt);
1365     ls.print("%d Initializing ", call_class_initializer_counter++);
1366     name()->print_value_on(&ls);
1367     ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1368   }
1369   if (h_method() != NULL) {
1370     JavaCallArguments args; // No arguments
1371     JavaValue result(T_VOID);
1372     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1373   }
1374 }
1375 
1376 
1377 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1378   InterpreterOopMap* entry_for) {
1379   // Lazily create the _oop_map_cache at first request
1380   // Lock-free access requires load_acquire.
1381   OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache);
1382   if (oop_map_cache == NULL) {
1383     MutexLocker x(OopMapCacheAlloc_lock);
1384     // Check if _oop_map_cache was allocated while we were waiting for this lock
1385     if ((oop_map_cache = _oop_map_cache) == NULL) {
1386       oop_map_cache = new OopMapCache();
1387       // Ensure _oop_map_cache is stable, since it is examined without a lock
1388       OrderAccess::release_store(&_oop_map_cache, oop_map_cache);
1389     }
1390   }
1391   // _oop_map_cache is constant after init; lookup below does its own locking.
1392   oop_map_cache->lookup(method, bci, entry_for);
1393 }
1394 
1395 
1396 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1397   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1398     Symbol* f_name = fs.name();
1399     Symbol* f_sig  = fs.signature();
1400     if (f_name == name && f_sig == sig) {
1401       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1402       return true;
1403     }
1404   }
1405   return false;
1406 }
1407 
1408 
1409 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1410   const int n = local_interfaces()->length();
1411   for (int i = 0; i < n; i++) {
1412     Klass* intf1 = local_interfaces()->at(i);
1413     assert(intf1->is_interface(), "just checking type");
1414     // search for field in current interface
1415     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1416       assert(fd->is_static(), "interface field must be static");
1417       return intf1;
1418     }
1419     // search for field in direct superinterfaces
1420     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1421     if (intf2 != NULL) return intf2;
1422   }
1423   // otherwise field lookup fails
1424   return NULL;
1425 }
1426 
1427 
1428 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1429   // search order according to newest JVM spec (5.4.3.2, p.167).
1430   // 1) search for field in current klass
1431   if (find_local_field(name, sig, fd)) {
1432     return const_cast<InstanceKlass*>(this);
1433   }
1434   // 2) search for field recursively in direct superinterfaces
1435   { Klass* intf = find_interface_field(name, sig, fd);
1436     if (intf != NULL) return intf;
1437   }
1438   // 3) apply field lookup recursively if superclass exists
1439   { Klass* supr = super();
1440     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1441   }
1442   // 4) otherwise field lookup fails
1443   return NULL;
1444 }
1445 
1446 
1447 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1448   // search order according to newest JVM spec (5.4.3.2, p.167).
1449   // 1) search for field in current klass
1450   if (find_local_field(name, sig, fd)) {
1451     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1452   }
1453   // 2) search for field recursively in direct superinterfaces
1454   if (is_static) {
1455     Klass* intf = find_interface_field(name, sig, fd);
1456     if (intf != NULL) return intf;
1457   }
1458   // 3) apply field lookup recursively if superclass exists
1459   { Klass* supr = super();
1460     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1461   }
1462   // 4) otherwise field lookup fails
1463   return NULL;
1464 }
1465 
1466 
1467 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1468   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1469     if (fs.offset() == offset) {
1470       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1471       if (fd->is_static() == is_static) return true;
1472     }
1473   }
1474   return false;
1475 }
1476 
1477 
1478 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1479   Klass* klass = const_cast<InstanceKlass*>(this);
1480   while (klass != NULL) {
1481     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1482       return true;
1483     }
1484     klass = klass->super();
1485   }
1486   return false;
1487 }
1488 
1489 
1490 void InstanceKlass::methods_do(void f(Method* method)) {
1491   // Methods aren't stable until they are loaded.  This can be read outside
1492   // a lock through the ClassLoaderData for profiling
1493   if (!is_loaded()) {
1494     return;
1495   }
1496 
1497   int len = methods()->length();
1498   for (int index = 0; index < len; index++) {
1499     Method* m = methods()->at(index);
1500     assert(m->is_method(), "must be method");
1501     f(m);
1502   }
1503 }
1504 
1505 
1506 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1507   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1508     if (fs.access_flags().is_static()) {
1509       fieldDescriptor& fd = fs.field_descriptor();
1510       cl->do_field(&fd);
1511     }
1512   }
1513 }
1514 
1515 
1516 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1517   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1518     if (fs.access_flags().is_static()) {
1519       fieldDescriptor& fd = fs.field_descriptor();
1520       f(&fd, mirror, CHECK);
1521     }
1522   }
1523 }
1524 
1525 
1526 static int compare_fields_by_offset(int* a, int* b) {
1527   return a[0] - b[0];
1528 }
1529 
1530 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1531   InstanceKlass* super = superklass();
1532   if (super != NULL) {
1533     super->do_nonstatic_fields(cl);
1534   }
1535   fieldDescriptor fd;
1536   int length = java_fields_count();
1537   // In DebugInfo nonstatic fields are sorted by offset.
1538   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1539   int j = 0;
1540   for (int i = 0; i < length; i += 1) {
1541     fd.reinitialize(this, i);
1542     if (!fd.is_static()) {
1543       fields_sorted[j + 0] = fd.offset();
1544       fields_sorted[j + 1] = i;
1545       j += 2;
1546     }
1547   }
1548   if (j > 0) {
1549     length = j;
1550     // _sort_Fn is defined in growableArray.hpp.
1551     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1552     for (int i = 0; i < length; i += 2) {
1553       fd.reinitialize(this, fields_sorted[i + 1]);
1554       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1555       cl->do_field(&fd);
1556     }
1557   }
1558   FREE_C_HEAP_ARRAY(int, fields_sorted);
1559 }
1560 
1561 
1562 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1563   if (array_klasses() != NULL)
1564     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1565 }
1566 
1567 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1568   if (array_klasses() != NULL)
1569     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1570 }
1571 
1572 #ifdef ASSERT
1573 static int linear_search(const Array<Method*>* methods,
1574                          const Symbol* name,
1575                          const Symbol* signature) {
1576   const int len = methods->length();
1577   for (int index = 0; index < len; index++) {
1578     const Method* const m = methods->at(index);
1579     assert(m->is_method(), "must be method");
1580     if (m->signature() == signature && m->name() == name) {
1581        return index;
1582     }
1583   }
1584   return -1;
1585 }
1586 #endif
1587 
1588 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1589   int len = methods->length();
1590   // methods are sorted, so do binary search
1591   int l = 0;
1592   int h = len - 1;
1593   while (l <= h) {
1594     int mid = (l + h) >> 1;
1595     Method* m = methods->at(mid);
1596     assert(m->is_method(), "must be method");
1597     int res = m->name()->fast_compare(name);
1598     if (res == 0) {
1599       return mid;
1600     } else if (res < 0) {
1601       l = mid + 1;
1602     } else {
1603       h = mid - 1;
1604     }
1605   }
1606   return -1;
1607 }
1608 
1609 // find_method looks up the name/signature in the local methods array
1610 Method* InstanceKlass::find_method(const Symbol* name,
1611                                    const Symbol* signature) const {
1612   return find_method_impl(name, signature, find_overpass, find_static, find_private);
1613 }
1614 
1615 Method* InstanceKlass::find_method_impl(const Symbol* name,
1616                                         const Symbol* signature,
1617                                         OverpassLookupMode overpass_mode,
1618                                         StaticLookupMode static_mode,
1619                                         PrivateLookupMode private_mode) const {
1620   return InstanceKlass::find_method_impl(methods(),
1621                                          name,
1622                                          signature,
1623                                          overpass_mode,
1624                                          static_mode,
1625                                          private_mode);
1626 }
1627 
1628 // find_instance_method looks up the name/signature in the local methods array
1629 // and skips over static methods
1630 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1631                                             const Symbol* name,
1632                                             const Symbol* signature,
1633                                             PrivateLookupMode private_mode) {
1634   Method* const meth = InstanceKlass::find_method_impl(methods,
1635                                                  name,
1636                                                  signature,
1637                                                  find_overpass,
1638                                                  skip_static,
1639                                                  private_mode);
1640   assert(((meth == NULL) || !meth->is_static()),
1641     "find_instance_method should have skipped statics");
1642   return meth;
1643 }
1644 
1645 // find_instance_method looks up the name/signature in the local methods array
1646 // and skips over static methods
1647 Method* InstanceKlass::find_instance_method(const Symbol* name,
1648                                             const Symbol* signature,
1649                                             PrivateLookupMode private_mode) const {
1650   return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1651 }
1652 
1653 // Find looks up the name/signature in the local methods array
1654 // and filters on the overpass, static and private flags
1655 // This returns the first one found
1656 // note that the local methods array can have up to one overpass, one static
1657 // and one instance (private or not) with the same name/signature
1658 Method* InstanceKlass::find_local_method(const Symbol* name,
1659                                          const Symbol* signature,
1660                                          OverpassLookupMode overpass_mode,
1661                                          StaticLookupMode static_mode,
1662                                          PrivateLookupMode private_mode) const {
1663   return InstanceKlass::find_method_impl(methods(),
1664                                          name,
1665                                          signature,
1666                                          overpass_mode,
1667                                          static_mode,
1668                                          private_mode);
1669 }
1670 
1671 // Find looks up the name/signature in the local methods array
1672 // and filters on the overpass, static and private flags
1673 // This returns the first one found
1674 // note that the local methods array can have up to one overpass, one static
1675 // and one instance (private or not) with the same name/signature
1676 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1677                                          const Symbol* name,
1678                                          const Symbol* signature,
1679                                          OverpassLookupMode overpass_mode,
1680                                          StaticLookupMode static_mode,
1681                                          PrivateLookupMode private_mode) {
1682   return InstanceKlass::find_method_impl(methods,
1683                                          name,
1684                                          signature,
1685                                          overpass_mode,
1686                                          static_mode,
1687                                          private_mode);
1688 }
1689 
1690 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1691                                    const Symbol* name,
1692                                    const Symbol* signature) {
1693   return InstanceKlass::find_method_impl(methods,
1694                                          name,
1695                                          signature,
1696                                          find_overpass,
1697                                          find_static,
1698                                          find_private);
1699 }
1700 
1701 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1702                                         const Symbol* name,
1703                                         const Symbol* signature,
1704                                         OverpassLookupMode overpass_mode,
1705                                         StaticLookupMode static_mode,
1706                                         PrivateLookupMode private_mode) {
1707   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1708   return hit >= 0 ? methods->at(hit): NULL;
1709 }
1710 
1711 // true if method matches signature and conforms to skipping_X conditions.
1712 static bool method_matches(const Method* m,
1713                            const Symbol* signature,
1714                            bool skipping_overpass,
1715                            bool skipping_static,
1716                            bool skipping_private) {
1717   return ((m->signature() == signature) &&
1718     (!skipping_overpass || !m->is_overpass()) &&
1719     (!skipping_static || !m->is_static()) &&
1720     (!skipping_private || !m->is_private()));
1721 }
1722 
1723 // Used directly for default_methods to find the index into the
1724 // default_vtable_indices, and indirectly by find_method
1725 // find_method_index looks in the local methods array to return the index
1726 // of the matching name/signature. If, overpass methods are being ignored,
1727 // the search continues to find a potential non-overpass match.  This capability
1728 // is important during method resolution to prefer a static method, for example,
1729 // over an overpass method.
1730 // There is the possibility in any _method's array to have the same name/signature
1731 // for a static method, an overpass method and a local instance method
1732 // To correctly catch a given method, the search criteria may need
1733 // to explicitly skip the other two. For local instance methods, it
1734 // is often necessary to skip private methods
1735 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1736                                      const Symbol* name,
1737                                      const Symbol* signature,
1738                                      OverpassLookupMode overpass_mode,
1739                                      StaticLookupMode static_mode,
1740                                      PrivateLookupMode private_mode) {
1741   const bool skipping_overpass = (overpass_mode == skip_overpass);
1742   const bool skipping_static = (static_mode == skip_static);
1743   const bool skipping_private = (private_mode == skip_private);
1744   const int hit = binary_search(methods, name);
1745   if (hit != -1) {
1746     const Method* const m = methods->at(hit);
1747 
1748     // Do linear search to find matching signature.  First, quick check
1749     // for common case, ignoring overpasses if requested.
1750     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1751       return hit;
1752     }
1753 
1754     // search downwards through overloaded methods
1755     int i;
1756     for (i = hit - 1; i >= 0; --i) {
1757         const Method* const m = methods->at(i);
1758         assert(m->is_method(), "must be method");
1759         if (m->name() != name) {
1760           break;
1761         }
1762         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1763           return i;
1764         }
1765     }
1766     // search upwards
1767     for (i = hit + 1; i < methods->length(); ++i) {
1768         const Method* const m = methods->at(i);
1769         assert(m->is_method(), "must be method");
1770         if (m->name() != name) {
1771           break;
1772         }
1773         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1774           return i;
1775         }
1776     }
1777     // not found
1778 #ifdef ASSERT
1779     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1780       linear_search(methods, name, signature);
1781     assert(-1 == index, "binary search should have found entry %d", index);
1782 #endif
1783   }
1784   return -1;
1785 }
1786 
1787 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1788   return find_method_by_name(methods(), name, end);
1789 }
1790 
1791 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1792                                        const Symbol* name,
1793                                        int* end_ptr) {
1794   assert(end_ptr != NULL, "just checking");
1795   int start = binary_search(methods, name);
1796   int end = start + 1;
1797   if (start != -1) {
1798     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1799     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1800     *end_ptr = end;
1801     return start;
1802   }
1803   return -1;
1804 }
1805 
1806 // uncached_lookup_method searches both the local class methods array and all
1807 // superclasses methods arrays, skipping any overpass methods in superclasses,
1808 // and possibly skipping private methods.
1809 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1810                                               const Symbol* signature,
1811                                               OverpassLookupMode overpass_mode,
1812                                               PrivateLookupMode private_mode) const {
1813   OverpassLookupMode overpass_local_mode = overpass_mode;
1814   const Klass* klass = this;
1815   while (klass != NULL) {
1816     Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1817                                                                         signature,
1818                                                                         overpass_local_mode,
1819                                                                         find_static,
1820                                                                         private_mode);
1821     if (method != NULL) {
1822       return method;
1823     }
1824     klass = klass->super();
1825     overpass_local_mode = skip_overpass;   // Always ignore overpass methods in superclasses
1826   }
1827   return NULL;
1828 }
1829 
1830 #ifdef ASSERT
1831 // search through class hierarchy and return true if this class or
1832 // one of the superclasses was redefined
1833 bool InstanceKlass::has_redefined_this_or_super() const {
1834   const Klass* klass = this;
1835   while (klass != NULL) {
1836     if (InstanceKlass::cast(klass)->has_been_redefined()) {
1837       return true;
1838     }
1839     klass = klass->super();
1840   }
1841   return false;
1842 }
1843 #endif
1844 
1845 // lookup a method in the default methods list then in all transitive interfaces
1846 // Do NOT return private or static methods
1847 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1848                                                          Symbol* signature) const {
1849   Method* m = NULL;
1850   if (default_methods() != NULL) {
1851     m = find_method(default_methods(), name, signature);
1852   }
1853   // Look up interfaces
1854   if (m == NULL) {
1855     m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1856   }
1857   return m;
1858 }
1859 
1860 // lookup a method in all the interfaces that this class implements
1861 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1862 // They should only be found in the initial InterfaceMethodRef
1863 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1864                                                        Symbol* signature,
1865                                                        DefaultsLookupMode defaults_mode) const {
1866   Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1867   int num_ifs = all_ifs->length();
1868   InstanceKlass *ik = NULL;
1869   for (int i = 0; i < num_ifs; i++) {
1870     ik = all_ifs->at(i);
1871     Method* m = ik->lookup_method(name, signature);
1872     if (m != NULL && m->is_public() && !m->is_static() &&
1873         ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1874       return m;
1875     }
1876   }
1877   return NULL;
1878 }
1879 
1880 /* jni_id_for_impl for jfieldIds only */
1881 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1882   MutexLocker ml(JfieldIdCreation_lock);
1883   // Retry lookup after we got the lock
1884   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1885   if (probe == NULL) {
1886     // Slow case, allocate new static field identifier
1887     probe = new JNIid(this, offset, jni_ids());
1888     set_jni_ids(probe);
1889   }
1890   return probe;
1891 }
1892 
1893 
1894 /* jni_id_for for jfieldIds only */
1895 JNIid* InstanceKlass::jni_id_for(int offset) {
1896   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1897   if (probe == NULL) {
1898     probe = jni_id_for_impl(offset);
1899   }
1900   return probe;
1901 }
1902 
1903 u2 InstanceKlass::enclosing_method_data(int offset) const {
1904   const Array<jushort>* const inner_class_list = inner_classes();
1905   if (inner_class_list == NULL) {
1906     return 0;
1907   }
1908   const int length = inner_class_list->length();
1909   if (length % inner_class_next_offset == 0) {
1910     return 0;
1911   }
1912   const int index = length - enclosing_method_attribute_size;
1913   assert(offset < enclosing_method_attribute_size, "invalid offset");
1914   return inner_class_list->at(index + offset);
1915 }
1916 
1917 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1918                                                  u2 method_index) {
1919   Array<jushort>* inner_class_list = inner_classes();
1920   assert (inner_class_list != NULL, "_inner_classes list is not set up");
1921   int length = inner_class_list->length();
1922   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1923     int index = length - enclosing_method_attribute_size;
1924     inner_class_list->at_put(
1925       index + enclosing_method_class_index_offset, class_index);
1926     inner_class_list->at_put(
1927       index + enclosing_method_method_index_offset, method_index);
1928   }
1929 }
1930 
1931 // Lookup or create a jmethodID.
1932 // This code is called by the VMThread and JavaThreads so the
1933 // locking has to be done very carefully to avoid deadlocks
1934 // and/or other cache consistency problems.
1935 //
1936 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
1937   size_t idnum = (size_t)method_h->method_idnum();
1938   jmethodID* jmeths = methods_jmethod_ids_acquire();
1939   size_t length = 0;
1940   jmethodID id = NULL;
1941 
1942   // We use a double-check locking idiom here because this cache is
1943   // performance sensitive. In the normal system, this cache only
1944   // transitions from NULL to non-NULL which is safe because we use
1945   // release_set_methods_jmethod_ids() to advertise the new cache.
1946   // A partially constructed cache should never be seen by a racing
1947   // thread. We also use release_store() to save a new jmethodID
1948   // in the cache so a partially constructed jmethodID should never be
1949   // seen either. Cache reads of existing jmethodIDs proceed without a
1950   // lock, but cache writes of a new jmethodID requires uniqueness and
1951   // creation of the cache itself requires no leaks so a lock is
1952   // generally acquired in those two cases.
1953   //
1954   // If the RedefineClasses() API has been used, then this cache can
1955   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1956   // Cache creation requires no leaks and we require safety between all
1957   // cache accesses and freeing of the old cache so a lock is generally
1958   // acquired when the RedefineClasses() API has been used.
1959 
1960   if (jmeths != NULL) {
1961     // the cache already exists
1962     if (!idnum_can_increment()) {
1963       // the cache can't grow so we can just get the current values
1964       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1965     } else {
1966       // cache can grow so we have to be more careful
1967       if (Threads::number_of_threads() == 0 ||
1968           SafepointSynchronize::is_at_safepoint()) {
1969         // we're single threaded or at a safepoint - no locking needed
1970         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1971       } else {
1972         MutexLocker ml(JmethodIdCreation_lock);
1973         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1974       }
1975     }
1976   }
1977   // implied else:
1978   // we need to allocate a cache so default length and id values are good
1979 
1980   if (jmeths == NULL ||   // no cache yet
1981       length <= idnum ||  // cache is too short
1982       id == NULL) {       // cache doesn't contain entry
1983 
1984     // This function can be called by the VMThread so we have to do all
1985     // things that might block on a safepoint before grabbing the lock.
1986     // Otherwise, we can deadlock with the VMThread or have a cache
1987     // consistency issue. These vars keep track of what we might have
1988     // to free after the lock is dropped.
1989     jmethodID  to_dealloc_id     = NULL;
1990     jmethodID* to_dealloc_jmeths = NULL;
1991 
1992     // may not allocate new_jmeths or use it if we allocate it
1993     jmethodID* new_jmeths = NULL;
1994     if (length <= idnum) {
1995       // allocate a new cache that might be used
1996       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1997       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1998       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1999       // cache size is stored in element[0], other elements offset by one
2000       new_jmeths[0] = (jmethodID)size;
2001     }
2002 
2003     // allocate a new jmethodID that might be used
2004     jmethodID new_id = NULL;
2005     if (method_h->is_old() && !method_h->is_obsolete()) {
2006       // The method passed in is old (but not obsolete), we need to use the current version
2007       Method* current_method = method_with_idnum((int)idnum);
2008       assert(current_method != NULL, "old and but not obsolete, so should exist");
2009       new_id = Method::make_jmethod_id(class_loader_data(), current_method);
2010     } else {
2011       // It is the current version of the method or an obsolete method,
2012       // use the version passed in
2013       new_id = Method::make_jmethod_id(class_loader_data(), method_h());
2014     }
2015 
2016     if (Threads::number_of_threads() == 0 ||
2017         SafepointSynchronize::is_at_safepoint()) {
2018       // we're single threaded or at a safepoint - no locking needed
2019       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2020                                           &to_dealloc_id, &to_dealloc_jmeths);
2021     } else {
2022       MutexLocker ml(JmethodIdCreation_lock);
2023       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2024                                           &to_dealloc_id, &to_dealloc_jmeths);
2025     }
2026 
2027     // The lock has been dropped so we can free resources.
2028     // Free up either the old cache or the new cache if we allocated one.
2029     if (to_dealloc_jmeths != NULL) {
2030       FreeHeap(to_dealloc_jmeths);
2031     }
2032     // free up the new ID since it wasn't needed
2033     if (to_dealloc_id != NULL) {
2034       Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
2035     }
2036   }
2037   return id;
2038 }
2039 
2040 // Figure out how many jmethodIDs haven't been allocated, and make
2041 // sure space for them is pre-allocated.  This makes getting all
2042 // method ids much, much faster with classes with more than 8
2043 // methods, and has a *substantial* effect on performance with jvmti
2044 // code that loads all jmethodIDs for all classes.
2045 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2046   int new_jmeths = 0;
2047   int length = methods()->length();
2048   for (int index = start_offset; index < length; index++) {
2049     Method* m = methods()->at(index);
2050     jmethodID id = m->find_jmethod_id_or_null();
2051     if (id == NULL) {
2052       new_jmeths++;
2053     }
2054   }
2055   if (new_jmeths != 0) {
2056     Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2057   }
2058 }
2059 
2060 // Common code to fetch the jmethodID from the cache or update the
2061 // cache with the new jmethodID. This function should never do anything
2062 // that causes the caller to go to a safepoint or we can deadlock with
2063 // the VMThread or have cache consistency issues.
2064 //
2065 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
2066             size_t idnum, jmethodID new_id,
2067             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
2068             jmethodID** to_dealloc_jmeths_p) {
2069   assert(new_id != NULL, "sanity check");
2070   assert(to_dealloc_id_p != NULL, "sanity check");
2071   assert(to_dealloc_jmeths_p != NULL, "sanity check");
2072   assert(Threads::number_of_threads() == 0 ||
2073          SafepointSynchronize::is_at_safepoint() ||
2074          JmethodIdCreation_lock->owned_by_self(), "sanity check");
2075 
2076   // reacquire the cache - we are locked, single threaded or at a safepoint
2077   jmethodID* jmeths = methods_jmethod_ids_acquire();
2078   jmethodID  id     = NULL;
2079   size_t     length = 0;
2080 
2081   if (jmeths == NULL ||                         // no cache yet
2082       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
2083     if (jmeths != NULL) {
2084       // copy any existing entries from the old cache
2085       for (size_t index = 0; index < length; index++) {
2086         new_jmeths[index+1] = jmeths[index+1];
2087       }
2088       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
2089     }
2090     release_set_methods_jmethod_ids(jmeths = new_jmeths);
2091   } else {
2092     // fetch jmethodID (if any) from the existing cache
2093     id = jmeths[idnum+1];
2094     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
2095   }
2096   if (id == NULL) {
2097     // No matching jmethodID in the existing cache or we have a new
2098     // cache or we just grew the cache. This cache write is done here
2099     // by the first thread to win the foot race because a jmethodID
2100     // needs to be unique once it is generally available.
2101     id = new_id;
2102 
2103     // The jmethodID cache can be read while unlocked so we have to
2104     // make sure the new jmethodID is complete before installing it
2105     // in the cache.
2106     OrderAccess::release_store(&jmeths[idnum+1], id);
2107   } else {
2108     *to_dealloc_id_p = new_id; // save new id for later delete
2109   }
2110   return id;
2111 }
2112 
2113 
2114 // Common code to get the jmethodID cache length and the jmethodID
2115 // value at index idnum if there is one.
2116 //
2117 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
2118        size_t idnum, size_t *length_p, jmethodID* id_p) {
2119   assert(cache != NULL, "sanity check");
2120   assert(length_p != NULL, "sanity check");
2121   assert(id_p != NULL, "sanity check");
2122 
2123   // cache size is stored in element[0], other elements offset by one
2124   *length_p = (size_t)cache[0];
2125   if (*length_p <= idnum) {  // cache is too short
2126     *id_p = NULL;
2127   } else {
2128     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
2129   }
2130 }
2131 
2132 
2133 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
2134 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2135   size_t idnum = (size_t)method->method_idnum();
2136   jmethodID* jmeths = methods_jmethod_ids_acquire();
2137   size_t length;                                // length assigned as debugging crumb
2138   jmethodID id = NULL;
2139   if (jmeths != NULL &&                         // If there is a cache
2140       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
2141     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
2142   }
2143   return id;
2144 }
2145 
2146 inline DependencyContext InstanceKlass::dependencies() {
2147   DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2148   return dep_context;
2149 }
2150 
2151 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
2152   return dependencies().mark_dependent_nmethods(changes);
2153 }
2154 
2155 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2156   dependencies().add_dependent_nmethod(nm);
2157 }
2158 
2159 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
2160   dependencies().remove_dependent_nmethod(nm);
2161 }
2162 
2163 void InstanceKlass::clean_dependency_context() {
2164   dependencies().clean_unloading_dependents();
2165 }
2166 
2167 #ifndef PRODUCT
2168 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2169   dependencies().print_dependent_nmethods(verbose);
2170 }
2171 
2172 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2173   return dependencies().is_dependent_nmethod(nm);
2174 }
2175 #endif //PRODUCT
2176 
2177 void InstanceKlass::clean_weak_instanceklass_links() {
2178   clean_implementors_list();
2179   clean_method_data();
2180 }
2181 
2182 void InstanceKlass::clean_implementors_list() {
2183   assert(is_loader_alive(), "this klass should be live");
2184   if (is_interface()) {
2185     assert (ClassUnloading, "only called for ClassUnloading");
2186     for (;;) {
2187       // Use load_acquire due to competing with inserts
2188       Klass* impl = OrderAccess::load_acquire(adr_implementor());
2189       if (impl != NULL && !impl->is_loader_alive()) {
2190         // NULL this field, might be an unloaded klass or NULL
2191         Klass* volatile* klass = adr_implementor();
2192         if (Atomic::cmpxchg((Klass*)NULL, klass, impl) == impl) {
2193           // Successfully unlinking implementor.
2194           if (log_is_enabled(Trace, class, unload)) {
2195             ResourceMark rm;
2196             log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2197           }
2198           return;
2199         }
2200       } else {
2201         return;
2202       }
2203     }
2204   }
2205 }
2206 
2207 void InstanceKlass::clean_method_data() {
2208   for (int m = 0; m < methods()->length(); m++) {
2209     MethodData* mdo = methods()->at(m)->method_data();
2210     if (mdo != NULL) {
2211       MutexLocker ml(SafepointSynchronize::is_at_safepoint() ? NULL : mdo->extra_data_lock());
2212       mdo->clean_method_data(/*always_clean*/false);
2213     }
2214   }
2215 }
2216 
2217 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
2218   if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
2219     ResourceMark rm;
2220     log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
2221     return false;
2222   }
2223 
2224   Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
2225   if (local_interfaces != NULL) {
2226     int length = local_interfaces->length();
2227     for (int i = 0; i < length; i++) {
2228       InstanceKlass* intf = local_interfaces->at(i);
2229       if (!intf->has_passed_fingerprint_check()) {
2230         ResourceMark rm;
2231         log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
2232         return false;
2233       }
2234     }
2235   }
2236 
2237   return true;
2238 }
2239 
2240 bool InstanceKlass::should_store_fingerprint(bool is_unsafe_anonymous) {
2241 #if INCLUDE_AOT
2242   // We store the fingerprint into the InstanceKlass only in the following 2 cases:
2243   if (CalculateClassFingerprint) {
2244     // (1) We are running AOT to generate a shared library.
2245     return true;
2246   }
2247   if (Arguments::is_dumping_archive()) {
2248     // (2) We are running -Xshare:dump or -XX:ArchiveClassesAtExit to create a shared archive
2249     return true;
2250   }
2251   if (UseAOT && is_unsafe_anonymous) {
2252     // (3) We are using AOT code from a shared library and see an unsafe anonymous class
2253     return true;
2254   }
2255 #endif
2256 
2257   // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
2258   // but do not store the 64-bit fingerprint to save space.
2259   return false;
2260 }
2261 
2262 bool InstanceKlass::has_stored_fingerprint() const {
2263 #if INCLUDE_AOT
2264   return should_store_fingerprint() || is_shared();
2265 #else
2266   return false;
2267 #endif
2268 }
2269 
2270 uint64_t InstanceKlass::get_stored_fingerprint() const {
2271   address adr = adr_fingerprint();
2272   if (adr != NULL) {
2273     return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
2274   }
2275   return 0;
2276 }
2277 
2278 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
2279   address adr = adr_fingerprint();
2280   if (adr != NULL) {
2281     Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2282 
2283     ResourceMark rm;
2284     log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2285   }
2286 }
2287 
2288 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2289   Klass::metaspace_pointers_do(it);
2290 
2291   if (log_is_enabled(Trace, cds)) {
2292     ResourceMark rm;
2293     log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2294   }
2295 
2296   it->push(&_annotations);
2297   it->push((Klass**)&_array_klasses);
2298   it->push(&_constants);
2299   it->push(&_inner_classes);
2300   it->push(&_array_name);
2301 #if INCLUDE_JVMTI
2302   it->push(&_previous_versions);
2303 #endif
2304   it->push(&_methods);
2305   it->push(&_default_methods);
2306   it->push(&_local_interfaces);
2307   it->push(&_transitive_interfaces);
2308   it->push(&_method_ordering);
2309   it->push(&_default_vtable_indices);
2310   it->push(&_fields);
2311 
2312   if (itable_length() > 0) {
2313     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2314     int method_table_offset_in_words = ioe->offset()/wordSize;
2315     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2316                          / itableOffsetEntry::size();
2317 
2318     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2319       if (ioe->interface_klass() != NULL) {
2320         it->push(ioe->interface_klass_addr());
2321         itableMethodEntry* ime = ioe->first_method_entry(this);
2322         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2323         for (int index = 0; index < n; index ++) {
2324           it->push(ime[index].method_addr());
2325         }
2326       }
2327     }
2328   }
2329 
2330   it->push(&_nest_members);
2331   it->push(&_record_components);
2332 }
2333 
2334 void InstanceKlass::remove_unshareable_info() {
2335   Klass::remove_unshareable_info();
2336 
2337   if (is_in_error_state()) {
2338     // Classes are attempted to link during dumping and may fail,
2339     // but these classes are still in the dictionary and class list in CLD.
2340     // Check in_error state first because in_error is > linked state, so
2341     // is_linked() is true.
2342     // If there's a linking error, there is nothing else to remove.
2343     return;
2344   }
2345 
2346   // Reset to the 'allocated' state to prevent any premature accessing to
2347   // a shared class at runtime while the class is still being loaded and
2348   // restored. A class' init_state is set to 'loaded' at runtime when it's
2349   // being added to class hierarchy (see SystemDictionary:::add_to_hierarchy()).
2350   _init_state = allocated;
2351 
2352   { // Otherwise this needs to take out the Compile_lock.
2353     assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2354     init_implementor();
2355   }
2356 
2357   constants()->remove_unshareable_info();
2358 
2359   for (int i = 0; i < methods()->length(); i++) {
2360     Method* m = methods()->at(i);
2361     m->remove_unshareable_info();
2362   }
2363 
2364   // do array classes also.
2365   if (array_klasses() != NULL) {
2366     array_klasses()->remove_unshareable_info();
2367   }
2368 
2369   // These are not allocated from metaspace. They are safe to set to NULL.
2370   _source_debug_extension = NULL;
2371   _dep_context = NULL;
2372   _osr_nmethods_head = NULL;
2373 #if INCLUDE_JVMTI
2374   _breakpoints = NULL;
2375   _previous_versions = NULL;
2376   _cached_class_file = NULL;
2377 #endif
2378 
2379   _init_thread = NULL;
2380   _methods_jmethod_ids = NULL;
2381   _jni_ids = NULL;
2382   _oop_map_cache = NULL;
2383   // clear _nest_host to ensure re-load at runtime
2384   _nest_host = NULL;
2385 }
2386 
2387 void InstanceKlass::remove_java_mirror() {
2388   Klass::remove_java_mirror();
2389 
2390   // do array classes also.
2391   if (array_klasses() != NULL) {
2392     array_klasses()->remove_java_mirror();
2393   }
2394 }
2395 
2396 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2397   // SystemDictionary::add_to_hierarchy() sets the init_state to loaded
2398   // before the InstanceKlass is added to the SystemDictionary. Make
2399   // sure the current state is <loaded.
2400   assert(!is_loaded(), "invalid init state");
2401   set_package(loader_data, CHECK);
2402   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2403 
2404   Array<Method*>* methods = this->methods();
2405   int num_methods = methods->length();
2406   for (int index = 0; index < num_methods; ++index) {
2407     methods->at(index)->restore_unshareable_info(CHECK);
2408   }
2409   if (JvmtiExport::has_redefined_a_class()) {
2410     // Reinitialize vtable because RedefineClasses may have changed some
2411     // entries in this vtable for super classes so the CDS vtable might
2412     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2413     // vtables in the shared system dictionary, only the main one.
2414     // It also redefines the itable too so fix that too.
2415     vtable().initialize_vtable(false, CHECK);
2416     itable().initialize_itable(false, CHECK);
2417   }
2418 
2419   // restore constant pool resolved references
2420   constants()->restore_unshareable_info(CHECK);
2421 
2422   if (array_klasses() != NULL) {
2423     // Array classes have null protection domain.
2424     // --> see ArrayKlass::complete_create_array_klass()
2425     array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2426   }
2427 }
2428 
2429 // returns true IFF is_in_error_state() has been changed as a result of this call.
2430 bool InstanceKlass::check_sharing_error_state() {
2431   assert(DumpSharedSpaces, "should only be called during dumping");
2432   bool old_state = is_in_error_state();
2433 
2434   if (!is_in_error_state()) {
2435     bool bad = false;
2436     for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2437       if (sup->is_in_error_state()) {
2438         bad = true;
2439         break;
2440       }
2441     }
2442     if (!bad) {
2443       Array<InstanceKlass*>* interfaces = transitive_interfaces();
2444       for (int i = 0; i < interfaces->length(); i++) {
2445         InstanceKlass* iface = interfaces->at(i);
2446         if (iface->is_in_error_state()) {
2447           bad = true;
2448           break;
2449         }
2450       }
2451     }
2452 
2453     if (bad) {
2454       set_in_error_state();
2455     }
2456   }
2457 
2458   return (old_state != is_in_error_state());
2459 }
2460 
2461 void InstanceKlass::set_class_loader_type(s2 loader_type) {
2462   switch (loader_type) {
2463   case ClassLoader::BOOT_LOADER:
2464     _misc_flags |= _misc_is_shared_boot_class;
2465     break;
2466   case ClassLoader::PLATFORM_LOADER:
2467     _misc_flags |= _misc_is_shared_platform_class;
2468     break;
2469   case ClassLoader::APP_LOADER:
2470     _misc_flags |= _misc_is_shared_app_class;
2471     break;
2472   default:
2473     ShouldNotReachHere();
2474     break;
2475   }
2476 }
2477 
2478 #if INCLUDE_JVMTI
2479 static void clear_all_breakpoints(Method* m) {
2480   m->clear_all_breakpoints();
2481 }
2482 #endif
2483 
2484 void InstanceKlass::unload_class(InstanceKlass* ik) {
2485   // Release dependencies.
2486   ik->dependencies().remove_all_dependents();
2487 
2488   // notify the debugger
2489   if (JvmtiExport::should_post_class_unload()) {
2490     JvmtiExport::post_class_unload(ik);
2491   }
2492 
2493   // notify ClassLoadingService of class unload
2494   ClassLoadingService::notify_class_unloaded(ik);
2495 
2496   if (Arguments::is_dumping_archive()) {
2497     SystemDictionaryShared::remove_dumptime_info(ik);
2498   }
2499 
2500   if (log_is_enabled(Info, class, unload)) {
2501     ResourceMark rm;
2502     log_info(class, unload)("unloading class %s " INTPTR_FORMAT, ik->external_name(), p2i(ik));
2503   }
2504 
2505   Events::log_class_unloading(Thread::current(), ik);
2506 
2507 #if INCLUDE_JFR
2508   assert(ik != NULL, "invariant");
2509   EventClassUnload event;
2510   event.set_unloadedClass(ik);
2511   event.set_definingClassLoader(ik->class_loader_data());
2512   event.commit();
2513 #endif
2514 }
2515 
2516 static void method_release_C_heap_structures(Method* m) {
2517   m->release_C_heap_structures();
2518 }
2519 
2520 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2521   // Clean up C heap
2522   ik->release_C_heap_structures();
2523   ik->constants()->release_C_heap_structures();
2524 
2525   // Deallocate and call destructors for MDO mutexes
2526   ik->methods_do(method_release_C_heap_structures);
2527 
2528 }
2529 
2530 void InstanceKlass::release_C_heap_structures() {
2531   // Can't release the constant pool here because the constant pool can be
2532   // deallocated separately from the InstanceKlass for default methods and
2533   // redefine classes.
2534 
2535   // Deallocate oop map cache
2536   if (_oop_map_cache != NULL) {
2537     delete _oop_map_cache;
2538     _oop_map_cache = NULL;
2539   }
2540 
2541   // Deallocate JNI identifiers for jfieldIDs
2542   JNIid::deallocate(jni_ids());
2543   set_jni_ids(NULL);
2544 
2545   jmethodID* jmeths = methods_jmethod_ids_acquire();
2546   if (jmeths != (jmethodID*)NULL) {
2547     release_set_methods_jmethod_ids(NULL);
2548     FreeHeap(jmeths);
2549   }
2550 
2551   assert(_dep_context == NULL,
2552          "dependencies should already be cleaned");
2553 
2554 #if INCLUDE_JVMTI
2555   // Deallocate breakpoint records
2556   if (breakpoints() != 0x0) {
2557     methods_do(clear_all_breakpoints);
2558     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2559   }
2560 
2561   // deallocate the cached class file
2562   if (_cached_class_file != NULL) {
2563     os::free(_cached_class_file);
2564     _cached_class_file = NULL;
2565   }
2566 #endif
2567 
2568   // Decrement symbol reference counts associated with the unloaded class.
2569   if (_name != NULL) _name->decrement_refcount();
2570   // unreference array name derived from this class name (arrays of an unloaded
2571   // class can't be referenced anymore).
2572   if (_array_name != NULL)  _array_name->decrement_refcount();
2573   FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2574 }
2575 
2576 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2577   if (array == NULL) {
2578     _source_debug_extension = NULL;
2579   } else {
2580     // Adding one to the attribute length in order to store a null terminator
2581     // character could cause an overflow because the attribute length is
2582     // already coded with an u4 in the classfile, but in practice, it's
2583     // unlikely to happen.
2584     assert((length+1) > length, "Overflow checking");
2585     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2586     for (int i = 0; i < length; i++) {
2587       sde[i] = array[i];
2588     }
2589     sde[length] = '\0';
2590     _source_debug_extension = sde;
2591   }
2592 }
2593 
2594 const char* InstanceKlass::signature_name() const {
2595   int hash_len = 0;
2596   char hash_buf[40];
2597 
2598   // If this is an unsafe anonymous class, append a hash to make the name unique
2599   if (is_unsafe_anonymous()) {
2600     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2601     jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2602     hash_len = (int)strlen(hash_buf);
2603   }
2604 
2605   // Get the internal name as a c string
2606   const char* src = (const char*) (name()->as_C_string());
2607   const int src_length = (int)strlen(src);
2608 
2609   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2610 
2611   // Add L as type indicator
2612   int dest_index = 0;
2613   dest[dest_index++] = JVM_SIGNATURE_CLASS;
2614 
2615   // Add the actual class name
2616   for (int src_index = 0; src_index < src_length; ) {
2617     dest[dest_index++] = src[src_index++];
2618   }
2619 
2620   // If we have a hash, append it
2621   for (int hash_index = 0; hash_index < hash_len; ) {
2622     dest[dest_index++] = hash_buf[hash_index++];
2623   }
2624 
2625   // Add the semicolon and the NULL
2626   dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
2627   dest[dest_index] = '\0';
2628   return dest;
2629 }
2630 
2631 // Used to obtain the package name from a fully qualified class name.
2632 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2633   if (name == NULL) {
2634     return NULL;
2635   } else {
2636     if (name->utf8_length() <= 0) {
2637       return NULL;
2638     }
2639     ResourceMark rm;
2640     const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2641     if (package_name == NULL) {
2642       return NULL;
2643     }
2644     Symbol* pkg_name = SymbolTable::new_symbol(package_name);
2645     return pkg_name;
2646   }
2647 }
2648 
2649 ModuleEntry* InstanceKlass::module() const {
2650   // For an unsafe anonymous class return the host class' module
2651   if (is_unsafe_anonymous()) {
2652     assert(unsafe_anonymous_host() != NULL, "unsafe anonymous class must have a host class");
2653     return unsafe_anonymous_host()->module();
2654   }
2655 
2656   // Class is in a named package
2657   if (!in_unnamed_package()) {
2658     return _package_entry->module();
2659   }
2660 
2661   // Class is in an unnamed package, return its loader's unnamed module
2662   return class_loader_data()->unnamed_module();
2663 }
2664 
2665 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2666 
2667   // ensure java/ packages only loaded by boot or platform builtin loaders
2668   check_prohibited_package(name(), loader_data, CHECK);
2669 
2670   TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2671 
2672   if (pkg_name != NULL && loader_data != NULL) {
2673 
2674     // Find in class loader's package entry table.
2675     _package_entry = loader_data->packages()->lookup_only(pkg_name);
2676 
2677     // If the package name is not found in the loader's package
2678     // entry table, it is an indication that the package has not
2679     // been defined. Consider it defined within the unnamed module.
2680     if (_package_entry == NULL) {
2681       ResourceMark rm;
2682 
2683       if (!ModuleEntryTable::javabase_defined()) {
2684         // Before java.base is defined during bootstrapping, define all packages in
2685         // the java.base module.  If a non-java.base package is erroneously placed
2686         // in the java.base module it will be caught later when java.base
2687         // is defined by ModuleEntryTable::verify_javabase_packages check.
2688         assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2689         _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2690       } else {
2691         assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2692         _package_entry = loader_data->packages()->lookup(pkg_name,
2693                                                          loader_data->unnamed_module());
2694       }
2695 
2696       // A package should have been successfully created
2697       assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2698              name()->as_C_string(), loader_data->loader_name_and_id());
2699     }
2700 
2701     if (log_is_enabled(Debug, module)) {
2702       ResourceMark rm;
2703       ModuleEntry* m = _package_entry->module();
2704       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2705                         external_name(),
2706                         pkg_name->as_C_string(),
2707                         loader_data->loader_name_and_id(),
2708                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2709     }
2710   } else {
2711     ResourceMark rm;
2712     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2713                       external_name(),
2714                       (loader_data != NULL) ? loader_data->loader_name_and_id() : "NULL",
2715                       UNNAMED_MODULE);
2716   }
2717 }
2718 
2719 
2720 // different versions of is_same_class_package
2721 
2722 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2723   oop classloader1 = this->class_loader();
2724   PackageEntry* classpkg1 = this->package();
2725   if (class2->is_objArray_klass()) {
2726     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2727   }
2728 
2729   oop classloader2;
2730   PackageEntry* classpkg2;
2731   if (class2->is_instance_klass()) {
2732     classloader2 = class2->class_loader();
2733     classpkg2 = class2->package();
2734   } else {
2735     assert(class2->is_typeArray_klass(), "should be type array");
2736     classloader2 = NULL;
2737     classpkg2 = NULL;
2738   }
2739 
2740   // Same package is determined by comparing class loader
2741   // and package entries. Both must be the same. This rule
2742   // applies even to classes that are defined in the unnamed
2743   // package, they still must have the same class loader.
2744   if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2745     return true;
2746   }
2747 
2748   return false;
2749 }
2750 
2751 // return true if this class and other_class are in the same package. Classloader
2752 // and classname information is enough to determine a class's package
2753 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2754                                           const Symbol* other_class_name) const {
2755   if (class_loader() != other_class_loader) {
2756     return false;
2757   }
2758   if (name()->fast_compare(other_class_name) == 0) {
2759      return true;
2760   }
2761 
2762   {
2763     ResourceMark rm;
2764 
2765     bool bad_class_name = false;
2766     const char* other_pkg =
2767       ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2768     if (bad_class_name) {
2769       return false;
2770     }
2771     // Check that package_from_name() returns NULL, not "", if there is no package.
2772     assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2773 
2774     const Symbol* const this_package_name =
2775       this->package() != NULL ? this->package()->name() : NULL;
2776 
2777     if (this_package_name == NULL || other_pkg == NULL) {
2778       // One of the two doesn't have a package.  Only return true if the other
2779       // one also doesn't have a package.
2780       return (const char*)this_package_name == other_pkg;
2781     }
2782 
2783     // Check if package is identical
2784     return this_package_name->equals(other_pkg);
2785   }
2786 }
2787 
2788 // Returns true iff super_method can be overridden by a method in targetclassname
2789 // See JLS 3rd edition 8.4.6.1
2790 // Assumes name-signature match
2791 // "this" is InstanceKlass of super_method which must exist
2792 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2793 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2794    // Private methods can not be overridden
2795    if (super_method->is_private()) {
2796      return false;
2797    }
2798    // If super method is accessible, then override
2799    if ((super_method->is_protected()) ||
2800        (super_method->is_public())) {
2801      return true;
2802    }
2803    // Package-private methods are not inherited outside of package
2804    assert(super_method->is_package_private(), "must be package private");
2805    return(is_same_class_package(targetclassloader(), targetclassname));
2806 }
2807 
2808 // Only boot and platform class loaders can define classes in "java/" packages.
2809 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2810                                              ClassLoaderData* loader_data,
2811                                              TRAPS) {
2812   if (!loader_data->is_boot_class_loader_data() &&
2813       !loader_data->is_platform_class_loader_data() &&
2814       class_name != NULL) {
2815     ResourceMark rm(THREAD);
2816     char* name = class_name->as_C_string();
2817     if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2818       TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2819       assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2820       name = pkg_name->as_C_string();
2821       const char* class_loader_name = loader_data->loader_name_and_id();
2822       StringUtils::replace_no_expand(name, "/", ".");
2823       const char* msg_text1 = "Class loader (instance of): ";
2824       const char* msg_text2 = " tried to load prohibited package name: ";
2825       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2826       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2827       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2828       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2829     }
2830   }
2831   return;
2832 }
2833 
2834 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2835   constantPoolHandle i_cp(THREAD, constants());
2836   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2837     int ioff = iter.inner_class_info_index();
2838     if (ioff != 0) {
2839       // Check to see if the name matches the class we're looking for
2840       // before attempting to find the class.
2841       if (i_cp->klass_name_at_matches(this, ioff)) {
2842         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2843         if (this == inner_klass) {
2844           *ooff = iter.outer_class_info_index();
2845           *noff = iter.inner_name_index();
2846           return true;
2847         }
2848       }
2849     }
2850   }
2851   return false;
2852 }
2853 
2854 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2855   InstanceKlass* outer_klass = NULL;
2856   *inner_is_member = false;
2857   int ooff = 0, noff = 0;
2858   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2859   if (has_inner_classes_attr) {
2860     constantPoolHandle i_cp(THREAD, constants());
2861     if (ooff != 0) {
2862       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2863       outer_klass = InstanceKlass::cast(ok);
2864       *inner_is_member = true;
2865     }
2866     if (NULL == outer_klass) {
2867       // It may be unsafe anonymous; try for that.
2868       int encl_method_class_idx = enclosing_method_class_index();
2869       if (encl_method_class_idx != 0) {
2870         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2871         outer_klass = InstanceKlass::cast(ok);
2872         *inner_is_member = false;
2873       }
2874     }
2875   }
2876 
2877   // If no inner class attribute found for this class.
2878   if (NULL == outer_klass) return NULL;
2879 
2880   // Throws an exception if outer klass has not declared k as an inner klass
2881   // We need evidence that each klass knows about the other, or else
2882   // the system could allow a spoof of an inner class to gain access rights.
2883   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2884   return outer_klass;
2885 }
2886 
2887 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2888   jint access = access_flags().as_int();
2889 
2890   // But check if it happens to be member class.
2891   InnerClassesIterator iter(this);
2892   for (; !iter.done(); iter.next()) {
2893     int ioff = iter.inner_class_info_index();
2894     // Inner class attribute can be zero, skip it.
2895     // Strange but true:  JVM spec. allows null inner class refs.
2896     if (ioff == 0) continue;
2897 
2898     // only look at classes that are already loaded
2899     // since we are looking for the flags for our self.
2900     Symbol* inner_name = constants()->klass_name_at(ioff);
2901     if (name() == inner_name) {
2902       // This is really a member class.
2903       access = iter.inner_access_flags();
2904       break;
2905     }
2906   }
2907   // Remember to strip ACC_SUPER bit
2908   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2909 }
2910 
2911 jint InstanceKlass::jvmti_class_status() const {
2912   jint result = 0;
2913 
2914   if (is_linked()) {
2915     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2916   }
2917 
2918   if (is_initialized()) {
2919     assert(is_linked(), "Class status is not consistent");
2920     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2921   }
2922   if (is_in_error_state()) {
2923     result |= JVMTI_CLASS_STATUS_ERROR;
2924   }
2925   return result;
2926 }
2927 
2928 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2929   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2930   int method_table_offset_in_words = ioe->offset()/wordSize;
2931   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2932                        / itableOffsetEntry::size();
2933 
2934   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2935     // If the interface isn't implemented by the receiver class,
2936     // the VM should throw IncompatibleClassChangeError.
2937     if (cnt >= nof_interfaces) {
2938       ResourceMark rm(THREAD);
2939       stringStream ss;
2940       bool same_module = (module() == holder->module());
2941       ss.print("Receiver class %s does not implement "
2942                "the interface %s defining the method to be called "
2943                "(%s%s%s)",
2944                external_name(), holder->external_name(),
2945                (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
2946                (same_module) ? "" : "; ",
2947                (same_module) ? "" : holder->class_in_module_of_loader());
2948       THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
2949     }
2950 
2951     Klass* ik = ioe->interface_klass();
2952     if (ik == holder) break;
2953   }
2954 
2955   itableMethodEntry* ime = ioe->first_method_entry(this);
2956   Method* m = ime[index].method();
2957   if (m == NULL) {
2958     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2959   }
2960   return m;
2961 }
2962 
2963 
2964 #if INCLUDE_JVMTI
2965 // update default_methods for redefineclasses for methods that are
2966 // not yet in the vtable due to concurrent subclass define and superinterface
2967 // redefinition
2968 // Note: those in the vtable, should have been updated via adjust_method_entries
2969 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
2970   // search the default_methods for uses of either obsolete or EMCP methods
2971   if (default_methods() != NULL) {
2972     for (int index = 0; index < default_methods()->length(); index ++) {
2973       Method* old_method = default_methods()->at(index);
2974       if (old_method == NULL || !old_method->is_old()) {
2975         continue; // skip uninteresting entries
2976       }
2977       assert(!old_method->is_deleted(), "default methods may not be deleted");
2978       Method* new_method = old_method->get_new_method();
2979       default_methods()->at_put(index, new_method);
2980 
2981       if (log_is_enabled(Info, redefine, class, update)) {
2982         ResourceMark rm;
2983         if (!(*trace_name_printed)) {
2984           log_info(redefine, class, update)
2985             ("adjust: klassname=%s default methods from name=%s",
2986              external_name(), old_method->method_holder()->external_name());
2987           *trace_name_printed = true;
2988         }
2989         log_debug(redefine, class, update, vtables)
2990           ("default method update: %s(%s) ",
2991            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
2992       }
2993     }
2994   }
2995 }
2996 #endif // INCLUDE_JVMTI
2997 
2998 // On-stack replacement stuff
2999 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3000   assert_lock_strong(CompiledMethod_lock);
3001 #ifndef PRODUCT
3002   if (TieredCompilation) {
3003       nmethod * prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3004       assert(prev == NULL || !prev->is_in_use(),
3005       "redundunt OSR recompilation detected. memory leak in CodeCache!");
3006   }
3007 #endif
3008   // only one compilation can be active
3009   {
3010     assert(n->is_osr_method(), "wrong kind of nmethod");
3011     n->set_osr_link(osr_nmethods_head());
3012     set_osr_nmethods_head(n);
3013     // Raise the highest osr level if necessary
3014     if (TieredCompilation) {
3015       Method* m = n->method();
3016       m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
3017     }
3018   }
3019 
3020   // Get rid of the osr methods for the same bci that have lower levels.
3021   if (TieredCompilation) {
3022     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3023       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3024       if (inv != NULL && inv->is_in_use()) {
3025         inv->make_not_entrant();
3026       }
3027     }
3028   }
3029 }
3030 
3031 // Remove osr nmethod from the list. Return true if found and removed.
3032 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3033   // This is a short non-blocking critical region, so the no safepoint check is ok.
3034   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock
3035                  , Mutex::_no_safepoint_check_flag);
3036   assert(n->is_osr_method(), "wrong kind of nmethod");
3037   nmethod* last = NULL;
3038   nmethod* cur  = osr_nmethods_head();
3039   int max_level = CompLevel_none;  // Find the max comp level excluding n
3040   Method* m = n->method();
3041   // Search for match
3042   bool found = false;
3043   while(cur != NULL && cur != n) {
3044     if (TieredCompilation && m == cur->method()) {
3045       // Find max level before n
3046       max_level = MAX2(max_level, cur->comp_level());
3047     }
3048     last = cur;
3049     cur = cur->osr_link();
3050   }
3051   nmethod* next = NULL;
3052   if (cur == n) {
3053     found = true;
3054     next = cur->osr_link();
3055     if (last == NULL) {
3056       // Remove first element
3057       set_osr_nmethods_head(next);
3058     } else {
3059       last->set_osr_link(next);
3060     }
3061   }
3062   n->set_osr_link(NULL);
3063   if (TieredCompilation) {
3064     cur = next;
3065     while (cur != NULL) {
3066       // Find max level after n
3067       if (m == cur->method()) {
3068         max_level = MAX2(max_level, cur->comp_level());
3069       }
3070       cur = cur->osr_link();
3071     }
3072     m->set_highest_osr_comp_level(max_level);
3073   }
3074   return found;
3075 }
3076 
3077 int InstanceKlass::mark_osr_nmethods(const Method* m) {
3078   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock,
3079                  Mutex::_no_safepoint_check_flag);
3080   nmethod* osr = osr_nmethods_head();
3081   int found = 0;
3082   while (osr != NULL) {
3083     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3084     if (osr->method() == m) {
3085       osr->mark_for_deoptimization();
3086       found++;
3087     }
3088     osr = osr->osr_link();
3089   }
3090   return found;
3091 }
3092 
3093 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3094   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock,
3095                  Mutex::_no_safepoint_check_flag);
3096   nmethod* osr = osr_nmethods_head();
3097   nmethod* best = NULL;
3098   while (osr != NULL) {
3099     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3100     // There can be a time when a c1 osr method exists but we are waiting
3101     // for a c2 version. When c2 completes its osr nmethod we will trash
3102     // the c1 version and only be able to find the c2 version. However
3103     // while we overflow in the c1 code at back branches we don't want to
3104     // try and switch to the same code as we are already running
3105 
3106     if (osr->method() == m &&
3107         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3108       if (match_level) {
3109         if (osr->comp_level() == comp_level) {
3110           // Found a match - return it.
3111           return osr;
3112         }
3113       } else {
3114         if (best == NULL || (osr->comp_level() > best->comp_level())) {
3115           if (osr->comp_level() == CompLevel_highest_tier) {
3116             // Found the best possible - return it.
3117             return osr;
3118           }
3119           best = osr;
3120         }
3121       }
3122     }
3123     osr = osr->osr_link();
3124   }
3125 
3126   assert(match_level == false || best == NULL, "shouldn't pick up anything if match_level is set");
3127   if (best != NULL && best->comp_level() >= comp_level) {
3128     return best;
3129   }
3130   return NULL;
3131 }
3132 
3133 // -----------------------------------------------------------------------------------------------------
3134 // Printing
3135 
3136 #ifndef PRODUCT
3137 
3138 #define BULLET  " - "
3139 
3140 static const char* state_names[] = {
3141   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3142 };
3143 
3144 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3145   for (int i = 0; i < len; i++) {
3146     intptr_t e = start[i];
3147     st->print("%d : " INTPTR_FORMAT, i, e);
3148     if (MetaspaceObj::is_valid((Metadata*)e)) {
3149       st->print(" ");
3150       ((Metadata*)e)->print_value_on(st);
3151     }
3152     st->cr();
3153   }
3154 }
3155 
3156 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3157   return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3158 }
3159 
3160 void InstanceKlass::print_on(outputStream* st) const {
3161   assert(is_klass(), "must be klass");
3162   Klass::print_on(st);
3163 
3164   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
3165   st->print(BULLET"klass size:        %d", size());                               st->cr();
3166   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
3167   st->print(BULLET"state:             "); st->print_cr("%s", state_names[_init_state]);
3168   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
3169   st->print(BULLET"super:             "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3170   st->print(BULLET"sub:               ");
3171   Klass* sub = subklass();
3172   int n;
3173   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
3174     if (n < MaxSubklassPrintSize) {
3175       sub->print_value_on(st);
3176       st->print("   ");
3177     }
3178   }
3179   if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3180   st->cr();
3181 
3182   if (is_interface()) {
3183     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
3184     if (nof_implementors() == 1) {
3185       st->print_cr(BULLET"implementor:    ");
3186       st->print("   ");
3187       implementor()->print_value_on(st);
3188       st->cr();
3189     }
3190   }
3191 
3192   st->print(BULLET"arrays:            "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3193   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
3194   if (Verbose || WizardMode) {
3195     Array<Method*>* method_array = methods();
3196     for (int i = 0; i < method_array->length(); i++) {
3197       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3198     }
3199   }
3200   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
3201   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
3202   if (Verbose && default_methods() != NULL) {
3203     Array<Method*>* method_array = default_methods();
3204     for (int i = 0; i < method_array->length(); i++) {
3205       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3206     }
3207   }
3208   if (default_vtable_indices() != NULL) {
3209     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
3210   }
3211   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
3212   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3213   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
3214   if (class_loader_data() != NULL) {
3215     st->print(BULLET"class loader data:  ");
3216     class_loader_data()->print_value_on(st);
3217     st->cr();
3218   }
3219   st->print(BULLET"unsafe anonymous host class:        "); Metadata::print_value_on_maybe_null(st, unsafe_anonymous_host()); st->cr();
3220   if (source_file_name() != NULL) {
3221     st->print(BULLET"source file:       ");
3222     source_file_name()->print_value_on(st);
3223     st->cr();
3224   }
3225   if (source_debug_extension() != NULL) {
3226     st->print(BULLET"source debug extension:       ");
3227     st->print("%s", source_debug_extension());
3228     st->cr();
3229   }
3230   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
3231   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
3232   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
3233   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
3234   {
3235     bool have_pv = false;
3236     // previous versions are linked together through the InstanceKlass
3237     for (InstanceKlass* pv_node = previous_versions();
3238          pv_node != NULL;
3239          pv_node = pv_node->previous_versions()) {
3240       if (!have_pv)
3241         st->print(BULLET"previous version:  ");
3242       have_pv = true;
3243       pv_node->constants()->print_value_on(st);
3244     }
3245     if (have_pv) st->cr();
3246   }
3247 
3248   if (generic_signature() != NULL) {
3249     st->print(BULLET"generic signature: ");
3250     generic_signature()->print_value_on(st);
3251     st->cr();
3252   }
3253   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
3254   st->print(BULLET"nest members:     "); nest_members()->print_value_on(st);     st->cr();
3255   if (record_components() != NULL) {
3256     st->print(BULLET"record components:     "); record_components()->print_value_on(st);     st->cr();
3257   }
3258   if (java_mirror() != NULL) {
3259     st->print(BULLET"java mirror:       ");
3260     java_mirror()->print_value_on(st);
3261     st->cr();
3262   } else {
3263     st->print_cr(BULLET"java mirror:       NULL");
3264   }
3265   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3266   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
3267   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3268   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
3269   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3270   FieldPrinter print_static_field(st);
3271   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3272   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3273   FieldPrinter print_nonstatic_field(st);
3274   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3275   ik->do_nonstatic_fields(&print_nonstatic_field);
3276 
3277   st->print(BULLET"non-static oop maps: ");
3278   OopMapBlock* map     = start_of_nonstatic_oop_maps();
3279   OopMapBlock* end_map = map + nonstatic_oop_map_count();
3280   while (map < end_map) {
3281     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3282     map++;
3283   }
3284   st->cr();
3285 }
3286 
3287 #endif //PRODUCT
3288 
3289 void InstanceKlass::print_value_on(outputStream* st) const {
3290   assert(is_klass(), "must be klass");
3291   if (Verbose || WizardMode)  access_flags().print_on(st);
3292   name()->print_value_on(st);
3293 }
3294 
3295 #ifndef PRODUCT
3296 
3297 void FieldPrinter::do_field(fieldDescriptor* fd) {
3298   _st->print(BULLET);
3299    if (_obj == NULL) {
3300      fd->print_on(_st);
3301      _st->cr();
3302    } else {
3303      fd->print_on_for(_st, _obj);
3304      _st->cr();
3305    }
3306 }
3307 
3308 
3309 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3310   Klass::oop_print_on(obj, st);
3311 
3312   if (this == SystemDictionary::String_klass()) {
3313     typeArrayOop value  = java_lang_String::value(obj);
3314     juint        length = java_lang_String::length(obj);
3315     if (value != NULL &&
3316         value->is_typeArray() &&
3317         length <= (juint) value->length()) {
3318       st->print(BULLET"string: ");
3319       java_lang_String::print(obj, st);
3320       st->cr();
3321       if (!WizardMode)  return;  // that is enough
3322     }
3323   }
3324 
3325   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3326   FieldPrinter print_field(st, obj);
3327   do_nonstatic_fields(&print_field);
3328 
3329   if (this == SystemDictionary::Class_klass()) {
3330     st->print(BULLET"signature: ");
3331     java_lang_Class::print_signature(obj, st);
3332     st->cr();
3333     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3334     st->print(BULLET"fake entry for mirror: ");
3335     Metadata::print_value_on_maybe_null(st, mirrored_klass);
3336     st->cr();
3337     Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3338     st->print(BULLET"fake entry for array: ");
3339     Metadata::print_value_on_maybe_null(st, array_klass);
3340     st->cr();
3341     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3342     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3343     Klass* real_klass = java_lang_Class::as_Klass(obj);
3344     if (real_klass != NULL && real_klass->is_instance_klass()) {
3345       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3346     }
3347   } else if (this == SystemDictionary::MethodType_klass()) {
3348     st->print(BULLET"signature: ");
3349     java_lang_invoke_MethodType::print_signature(obj, st);
3350     st->cr();
3351   }
3352 }
3353 
3354 bool InstanceKlass::verify_itable_index(int i) {
3355   int method_count = klassItable::method_count_for_interface(this);
3356   assert(i >= 0 && i < method_count, "index out of bounds");
3357   return true;
3358 }
3359 
3360 #endif //PRODUCT
3361 
3362 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3363   st->print("a ");
3364   name()->print_value_on(st);
3365   obj->print_address_on(st);
3366   if (this == SystemDictionary::String_klass()
3367       && java_lang_String::value(obj) != NULL) {
3368     ResourceMark rm;
3369     int len = java_lang_String::length(obj);
3370     int plen = (len < 24 ? len : 12);
3371     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3372     st->print(" = \"%s\"", str);
3373     if (len > plen)
3374       st->print("...[%d]", len);
3375   } else if (this == SystemDictionary::Class_klass()) {
3376     Klass* k = java_lang_Class::as_Klass(obj);
3377     st->print(" = ");
3378     if (k != NULL) {
3379       k->print_value_on(st);
3380     } else {
3381       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3382       st->print("%s", tname ? tname : "type?");
3383     }
3384   } else if (this == SystemDictionary::MethodType_klass()) {
3385     st->print(" = ");
3386     java_lang_invoke_MethodType::print_signature(obj, st);
3387   } else if (java_lang_boxing_object::is_instance(obj)) {
3388     st->print(" = ");
3389     java_lang_boxing_object::print(obj, st);
3390   } else if (this == SystemDictionary::LambdaForm_klass()) {
3391     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3392     if (vmentry != NULL) {
3393       st->print(" => ");
3394       vmentry->print_value_on(st);
3395     }
3396   } else if (this == SystemDictionary::MemberName_klass()) {
3397     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3398     if (vmtarget != NULL) {
3399       st->print(" = ");
3400       vmtarget->print_value_on(st);
3401     } else {
3402       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3403       st->print(".");
3404       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3405     }
3406   }
3407 }
3408 
3409 const char* InstanceKlass::internal_name() const {
3410   return external_name();
3411 }
3412 
3413 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3414                                              const char* module_name,
3415                                              const ClassFileStream* cfs) const {
3416   if (!log_is_enabled(Info, class, load)) {
3417     return;
3418   }
3419 
3420   ResourceMark rm;
3421   LogMessage(class, load) msg;
3422   stringStream info_stream;
3423 
3424   // Name and class hierarchy info
3425   info_stream.print("%s", external_name());
3426 
3427   // Source
3428   if (cfs != NULL) {
3429     if (cfs->source() != NULL) {
3430       if (module_name != NULL) {
3431         // When the boot loader created the stream, it didn't know the module name
3432         // yet. Let's format it now.
3433         if (cfs->from_boot_loader_modules_image()) {
3434           info_stream.print(" source: jrt:/%s", module_name);
3435         } else {
3436           info_stream.print(" source: %s", cfs->source());
3437         }
3438       } else {
3439         info_stream.print(" source: %s", cfs->source());
3440       }
3441     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3442       Thread* THREAD = Thread::current();
3443       Klass* caller =
3444             THREAD->is_Java_thread()
3445                 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3446                 : NULL;
3447       // caller can be NULL, for example, during a JVMTI VM_Init hook
3448       if (caller != NULL) {
3449         info_stream.print(" source: instance of %s", caller->external_name());
3450       } else {
3451         // source is unknown
3452       }
3453     } else {
3454       oop class_loader = loader_data->class_loader();
3455       info_stream.print(" source: %s", class_loader->klass()->external_name());
3456     }
3457   } else {
3458     assert(this->is_shared(), "must be");
3459     if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3460       info_stream.print(" source: shared objects file (top)");
3461     } else {
3462       info_stream.print(" source: shared objects file");
3463     }
3464   }
3465 
3466   msg.info("%s", info_stream.as_string());
3467 
3468   if (log_is_enabled(Debug, class, load)) {
3469     stringStream debug_stream;
3470 
3471     // Class hierarchy info
3472     debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3473                        p2i(this),  p2i(superklass()));
3474 
3475     // Interfaces
3476     if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3477       debug_stream.print(" interfaces:");
3478       int length = local_interfaces()->length();
3479       for (int i = 0; i < length; i++) {
3480         debug_stream.print(" " INTPTR_FORMAT,
3481                            p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3482       }
3483     }
3484 
3485     // Class loader
3486     debug_stream.print(" loader: [");
3487     loader_data->print_value_on(&debug_stream);
3488     debug_stream.print("]");
3489 
3490     // Classfile checksum
3491     if (cfs) {
3492       debug_stream.print(" bytes: %d checksum: %08x",
3493                          cfs->length(),
3494                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
3495                          cfs->length()));
3496     }
3497 
3498     msg.debug("%s", debug_stream.as_string());
3499   }
3500 }
3501 
3502 #if INCLUDE_SERVICES
3503 // Size Statistics
3504 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3505   Klass::collect_statistics(sz);
3506 
3507   sz->_inst_size  = wordSize * size_helper();
3508   sz->_vtab_bytes = wordSize * vtable_length();
3509   sz->_itab_bytes = wordSize * itable_length();
3510   sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3511 
3512   int n = 0;
3513   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
3514   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
3515   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
3516   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3517   n += (sz->_fields_bytes                = sz->count_array(fields()));
3518   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
3519   n += (sz->_nest_members_bytes          = sz->count_array(nest_members()));
3520   n += (sz->_record_components_bytes     = sz->count_array(record_components()));
3521   sz->_ro_bytes += n;
3522 
3523   const ConstantPool* cp = constants();
3524   if (cp) {
3525     cp->collect_statistics(sz);
3526   }
3527 
3528   const Annotations* anno = annotations();
3529   if (anno) {
3530     anno->collect_statistics(sz);
3531   }
3532 
3533   const Array<Method*>* methods_array = methods();
3534   if (methods()) {
3535     for (int i = 0; i < methods_array->length(); i++) {
3536       Method* method = methods_array->at(i);
3537       if (method) {
3538         sz->_method_count ++;
3539         method->collect_statistics(sz);
3540       }
3541     }
3542   }
3543 
3544   const Array<RecordComponent*>* components = record_components();
3545   if (components != NULL) {
3546     for (int i = 0; i < components->length(); i++) {
3547       RecordComponent* component = components->at(i);
3548       if (component) {
3549         component->collect_statistics(sz);
3550       }
3551     }
3552   }
3553 
3554 }
3555 #endif // INCLUDE_SERVICES
3556 
3557 // Verification
3558 
3559 class VerifyFieldClosure: public BasicOopIterateClosure {
3560  protected:
3561   template <class T> void do_oop_work(T* p) {
3562     oop obj = RawAccess<>::oop_load(p);
3563     if (!oopDesc::is_oop_or_null(obj)) {
3564       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3565       Universe::print_on(tty);
3566       guarantee(false, "boom");
3567     }
3568   }
3569  public:
3570   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3571   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3572 };
3573 
3574 void InstanceKlass::verify_on(outputStream* st) {
3575 #ifndef PRODUCT
3576   // Avoid redundant verifies, this really should be in product.
3577   if (_verify_count == Universe::verify_count()) return;
3578   _verify_count = Universe::verify_count();
3579 #endif
3580 
3581   // Verify Klass
3582   Klass::verify_on(st);
3583 
3584   // Verify that klass is present in ClassLoaderData
3585   guarantee(class_loader_data()->contains_klass(this),
3586             "this class isn't found in class loader data");
3587 
3588   // Verify vtables
3589   if (is_linked()) {
3590     // $$$ This used to be done only for m/s collections.  Doing it
3591     // always seemed a valid generalization.  (DLD -- 6/00)
3592     vtable().verify(st);
3593   }
3594 
3595   // Verify first subklass
3596   if (subklass() != NULL) {
3597     guarantee(subklass()->is_klass(), "should be klass");
3598   }
3599 
3600   // Verify siblings
3601   Klass* super = this->super();
3602   Klass* sib = next_sibling();
3603   if (sib != NULL) {
3604     if (sib == this) {
3605       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3606     }
3607 
3608     guarantee(sib->is_klass(), "should be klass");
3609     guarantee(sib->super() == super, "siblings should have same superklass");
3610   }
3611 
3612   // Verify local interfaces
3613   if (local_interfaces()) {
3614     Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
3615     for (int j = 0; j < local_interfaces->length(); j++) {
3616       InstanceKlass* e = local_interfaces->at(j);
3617       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3618     }
3619   }
3620 
3621   // Verify transitive interfaces
3622   if (transitive_interfaces() != NULL) {
3623     Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
3624     for (int j = 0; j < transitive_interfaces->length(); j++) {
3625       InstanceKlass* e = transitive_interfaces->at(j);
3626       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3627     }
3628   }
3629 
3630   // Verify methods
3631   if (methods() != NULL) {
3632     Array<Method*>* methods = this->methods();
3633     for (int j = 0; j < methods->length(); j++) {
3634       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3635     }
3636     for (int j = 0; j < methods->length() - 1; j++) {
3637       Method* m1 = methods->at(j);
3638       Method* m2 = methods->at(j + 1);
3639       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3640     }
3641   }
3642 
3643   // Verify method ordering
3644   if (method_ordering() != NULL) {
3645     Array<int>* method_ordering = this->method_ordering();
3646     int length = method_ordering->length();
3647     if (JvmtiExport::can_maintain_original_method_order() ||
3648         ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3649       guarantee(length == methods()->length(), "invalid method ordering length");
3650       jlong sum = 0;
3651       for (int j = 0; j < length; j++) {
3652         int original_index = method_ordering->at(j);
3653         guarantee(original_index >= 0, "invalid method ordering index");
3654         guarantee(original_index < length, "invalid method ordering index");
3655         sum += original_index;
3656       }
3657       // Verify sum of indices 0,1,...,length-1
3658       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3659     } else {
3660       guarantee(length == 0, "invalid method ordering length");
3661     }
3662   }
3663 
3664   // Verify default methods
3665   if (default_methods() != NULL) {
3666     Array<Method*>* methods = this->default_methods();
3667     for (int j = 0; j < methods->length(); j++) {
3668       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3669     }
3670     for (int j = 0; j < methods->length() - 1; j++) {
3671       Method* m1 = methods->at(j);
3672       Method* m2 = methods->at(j + 1);
3673       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3674     }
3675   }
3676 
3677   // Verify JNI static field identifiers
3678   if (jni_ids() != NULL) {
3679     jni_ids()->verify(this);
3680   }
3681 
3682   // Verify other fields
3683   if (array_klasses() != NULL) {
3684     guarantee(array_klasses()->is_klass(), "should be klass");
3685   }
3686   if (constants() != NULL) {
3687     guarantee(constants()->is_constantPool(), "should be constant pool");
3688   }
3689   const Klass* anonymous_host = unsafe_anonymous_host();
3690   if (anonymous_host != NULL) {
3691     guarantee(anonymous_host->is_klass(), "should be klass");
3692   }
3693 }
3694 
3695 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3696   Klass::oop_verify_on(obj, st);
3697   VerifyFieldClosure blk;
3698   obj->oop_iterate(&blk);
3699 }
3700 
3701 
3702 // JNIid class for jfieldIDs only
3703 // Note to reviewers:
3704 // These JNI functions are just moved over to column 1 and not changed
3705 // in the compressed oops workspace.
3706 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3707   _holder = holder;
3708   _offset = offset;
3709   _next = next;
3710   debug_only(_is_static_field_id = false;)
3711 }
3712 
3713 
3714 JNIid* JNIid::find(int offset) {
3715   JNIid* current = this;
3716   while (current != NULL) {
3717     if (current->offset() == offset) return current;
3718     current = current->next();
3719   }
3720   return NULL;
3721 }
3722 
3723 void JNIid::deallocate(JNIid* current) {
3724   while (current != NULL) {
3725     JNIid* next = current->next();
3726     delete current;
3727     current = next;
3728   }
3729 }
3730 
3731 
3732 void JNIid::verify(Klass* holder) {
3733   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3734   int end_field_offset;
3735   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3736 
3737   JNIid* current = this;
3738   while (current != NULL) {
3739     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3740 #ifdef ASSERT
3741     int o = current->offset();
3742     if (current->is_static_field_id()) {
3743       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3744     }
3745 #endif
3746     current = current->next();
3747   }
3748 }
3749 
3750 void InstanceKlass::set_init_state(ClassState state) {
3751 #ifdef ASSERT
3752   bool good_state = is_shared() ? (_init_state <= state)
3753                                                : (_init_state < state);
3754   assert(good_state || state == allocated, "illegal state transition");
3755 #endif
3756   assert(_init_thread == NULL, "should be cleared before state change");
3757   _init_state = (u1)state;
3758 }
3759 
3760 #if INCLUDE_JVMTI
3761 
3762 // RedefineClasses() support for previous versions
3763 
3764 // Globally, there is at least one previous version of a class to walk
3765 // during class unloading, which is saved because old methods in the class
3766 // are still running.   Otherwise the previous version list is cleaned up.
3767 bool InstanceKlass::_has_previous_versions = false;
3768 
3769 // Returns true if there are previous versions of a class for class
3770 // unloading only. Also resets the flag to false. purge_previous_version
3771 // will set the flag to true if there are any left, i.e., if there's any
3772 // work to do for next time. This is to avoid the expensive code cache
3773 // walk in CLDG::clean_deallocate_lists().
3774 bool InstanceKlass::has_previous_versions_and_reset() {
3775   bool ret = _has_previous_versions;
3776   log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3777      ret ? "true" : "false");
3778   _has_previous_versions = false;
3779   return ret;
3780 }
3781 
3782 // Purge previous versions before adding new previous versions of the class and
3783 // during class unloading.
3784 void InstanceKlass::purge_previous_version_list() {
3785   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3786   assert(has_been_redefined(), "Should only be called for main class");
3787 
3788   // Quick exit.
3789   if (previous_versions() == NULL) {
3790     return;
3791   }
3792 
3793   // This klass has previous versions so see what we can cleanup
3794   // while it is safe to do so.
3795 
3796   int deleted_count = 0;    // leave debugging breadcrumbs
3797   int live_count = 0;
3798   ClassLoaderData* loader_data = class_loader_data();
3799   assert(loader_data != NULL, "should never be null");
3800 
3801   ResourceMark rm;
3802   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3803 
3804   // previous versions are linked together through the InstanceKlass
3805   InstanceKlass* pv_node = previous_versions();
3806   InstanceKlass* last = this;
3807   int version = 0;
3808 
3809   // check the previous versions list
3810   for (; pv_node != NULL; ) {
3811 
3812     ConstantPool* pvcp = pv_node->constants();
3813     assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3814 
3815     if (!pvcp->on_stack()) {
3816       // If the constant pool isn't on stack, none of the methods
3817       // are executing.  Unlink this previous_version.
3818       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3819       // so will be deallocated during the next phase of class unloading.
3820       log_trace(redefine, class, iklass, purge)
3821         ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3822       // For debugging purposes.
3823       pv_node->set_is_scratch_class();
3824       // Unlink from previous version list.
3825       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3826       InstanceKlass* next = pv_node->previous_versions();
3827       pv_node->link_previous_versions(NULL);   // point next to NULL
3828       last->link_previous_versions(next);
3829       // Add to the deallocate list after unlinking
3830       loader_data->add_to_deallocate_list(pv_node);
3831       pv_node = next;
3832       deleted_count++;
3833       version++;
3834       continue;
3835     } else {
3836       log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3837       assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3838       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3839       live_count++;
3840       // found a previous version for next time we do class unloading
3841       _has_previous_versions = true;
3842     }
3843 
3844     // At least one method is live in this previous version.
3845     // Reset dead EMCP methods not to get breakpoints.
3846     // All methods are deallocated when all of the methods for this class are no
3847     // longer running.
3848     Array<Method*>* method_refs = pv_node->methods();
3849     if (method_refs != NULL) {
3850       log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3851       for (int j = 0; j < method_refs->length(); j++) {
3852         Method* method = method_refs->at(j);
3853 
3854         if (!method->on_stack()) {
3855           // no breakpoints for non-running methods
3856           if (method->is_running_emcp()) {
3857             method->set_running_emcp(false);
3858           }
3859         } else {
3860           assert (method->is_obsolete() || method->is_running_emcp(),
3861                   "emcp method cannot run after emcp bit is cleared");
3862           log_trace(redefine, class, iklass, purge)
3863             ("purge: %s(%s): prev method @%d in version @%d is alive",
3864              method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3865         }
3866       }
3867     }
3868     // next previous version
3869     last = pv_node;
3870     pv_node = pv_node->previous_versions();
3871     version++;
3872   }
3873   log_trace(redefine, class, iklass, purge)
3874     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3875 }
3876 
3877 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3878                                                 int emcp_method_count) {
3879   int obsolete_method_count = old_methods->length() - emcp_method_count;
3880 
3881   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3882       _previous_versions != NULL) {
3883     // We have a mix of obsolete and EMCP methods so we have to
3884     // clear out any matching EMCP method entries the hard way.
3885     int local_count = 0;
3886     for (int i = 0; i < old_methods->length(); i++) {
3887       Method* old_method = old_methods->at(i);
3888       if (old_method->is_obsolete()) {
3889         // only obsolete methods are interesting
3890         Symbol* m_name = old_method->name();
3891         Symbol* m_signature = old_method->signature();
3892 
3893         // previous versions are linked together through the InstanceKlass
3894         int j = 0;
3895         for (InstanceKlass* prev_version = _previous_versions;
3896              prev_version != NULL;
3897              prev_version = prev_version->previous_versions(), j++) {
3898 
3899           Array<Method*>* method_refs = prev_version->methods();
3900           for (int k = 0; k < method_refs->length(); k++) {
3901             Method* method = method_refs->at(k);
3902 
3903             if (!method->is_obsolete() &&
3904                 method->name() == m_name &&
3905                 method->signature() == m_signature) {
3906               // The current RedefineClasses() call has made all EMCP
3907               // versions of this method obsolete so mark it as obsolete
3908               log_trace(redefine, class, iklass, add)
3909                 ("%s(%s): flush obsolete method @%d in version @%d",
3910                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
3911 
3912               method->set_is_obsolete();
3913               break;
3914             }
3915           }
3916 
3917           // The previous loop may not find a matching EMCP method, but
3918           // that doesn't mean that we can optimize and not go any
3919           // further back in the PreviousVersion generations. The EMCP
3920           // method for this generation could have already been made obsolete,
3921           // but there still may be an older EMCP method that has not
3922           // been made obsolete.
3923         }
3924 
3925         if (++local_count >= obsolete_method_count) {
3926           // no more obsolete methods so bail out now
3927           break;
3928         }
3929       }
3930     }
3931   }
3932 }
3933 
3934 // Save the scratch_class as the previous version if any of the methods are running.
3935 // The previous_versions are used to set breakpoints in EMCP methods and they are
3936 // also used to clean MethodData links to redefined methods that are no longer running.
3937 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3938                                          int emcp_method_count) {
3939   assert(Thread::current()->is_VM_thread(),
3940          "only VMThread can add previous versions");
3941 
3942   ResourceMark rm;
3943   log_trace(redefine, class, iklass, add)
3944     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3945 
3946   // Clean out old previous versions for this class
3947   purge_previous_version_list();
3948 
3949   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
3950   // a previous redefinition may be made obsolete by this redefinition.
3951   Array<Method*>* old_methods = scratch_class->methods();
3952   mark_newly_obsolete_methods(old_methods, emcp_method_count);
3953 
3954   // If the constant pool for this previous version of the class
3955   // is not marked as being on the stack, then none of the methods
3956   // in this previous version of the class are on the stack so
3957   // we don't need to add this as a previous version.
3958   ConstantPool* cp_ref = scratch_class->constants();
3959   if (!cp_ref->on_stack()) {
3960     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3961     // For debugging purposes.
3962     scratch_class->set_is_scratch_class();
3963     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3964     return;
3965   }
3966 
3967   if (emcp_method_count != 0) {
3968     // At least one method is still running, check for EMCP methods
3969     for (int i = 0; i < old_methods->length(); i++) {
3970       Method* old_method = old_methods->at(i);
3971       if (!old_method->is_obsolete() && old_method->on_stack()) {
3972         // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3973         // we can add breakpoints for it.
3974 
3975         // We set the method->on_stack bit during safepoints for class redefinition
3976         // and use this bit to set the is_running_emcp bit.
3977         // After the safepoint, the on_stack bit is cleared and the running emcp
3978         // method may exit.   If so, we would set a breakpoint in a method that
3979         // is never reached, but this won't be noticeable to the programmer.
3980         old_method->set_running_emcp(true);
3981         log_trace(redefine, class, iklass, add)
3982           ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3983       } else if (!old_method->is_obsolete()) {
3984         log_trace(redefine, class, iklass, add)
3985           ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3986       }
3987     }
3988   }
3989 
3990   // Add previous version if any methods are still running.
3991   // Set has_previous_version flag for processing during class unloading.
3992   _has_previous_versions = true;
3993   log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3994   assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3995   scratch_class->link_previous_versions(previous_versions());
3996   link_previous_versions(scratch_class);
3997 } // end add_previous_version()
3998 
3999 #endif // INCLUDE_JVMTI
4000 
4001 Method* InstanceKlass::method_with_idnum(int idnum) {
4002   Method* m = NULL;
4003   if (idnum < methods()->length()) {
4004     m = methods()->at(idnum);
4005   }
4006   if (m == NULL || m->method_idnum() != idnum) {
4007     for (int index = 0; index < methods()->length(); ++index) {
4008       m = methods()->at(index);
4009       if (m->method_idnum() == idnum) {
4010         return m;
4011       }
4012     }
4013     // None found, return null for the caller to handle.
4014     return NULL;
4015   }
4016   return m;
4017 }
4018 
4019 
4020 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4021   if (idnum >= methods()->length()) {
4022     return NULL;
4023   }
4024   Method* m = methods()->at(idnum);
4025   if (m != NULL && m->orig_method_idnum() == idnum) {
4026     return m;
4027   }
4028   // Obsolete method idnum does not match the original idnum
4029   for (int index = 0; index < methods()->length(); ++index) {
4030     m = methods()->at(index);
4031     if (m->orig_method_idnum() == idnum) {
4032       return m;
4033     }
4034   }
4035   // None found, return null for the caller to handle.
4036   return NULL;
4037 }
4038 
4039 
4040 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4041   InstanceKlass* holder = get_klass_version(version);
4042   if (holder == NULL) {
4043     return NULL; // The version of klass is gone, no method is found
4044   }
4045   Method* method = holder->method_with_orig_idnum(idnum);
4046   return method;
4047 }
4048 
4049 #if INCLUDE_JVMTI
4050 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4051   return _cached_class_file;
4052 }
4053 
4054 jint InstanceKlass::get_cached_class_file_len() {
4055   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4056 }
4057 
4058 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4059   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4060 }
4061 #endif