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