1 /*
   2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "aot/aotLoader.hpp"
  28 #include "classfile/classFileParser.hpp"
  29 #include "classfile/classFileStream.hpp"
  30 #include "classfile/classLoader.hpp"
  31 #include "classfile/classLoaderData.inline.hpp"
  32 #include "classfile/javaClasses.hpp"
  33 #include "classfile/moduleEntry.hpp"
  34 #include "classfile/symbolTable.hpp"
  35 #include "classfile/systemDictionary.hpp"
  36 #include "classfile/systemDictionaryShared.hpp"
  37 #include "classfile/verifier.hpp"
  38 #include "classfile/vmSymbols.hpp"
  39 #include "code/dependencyContext.hpp"
  40 #include "compiler/compileBroker.hpp"
  41 #include "gc/shared/collectedHeap.inline.hpp"
  42 #include "interpreter/oopMapCache.hpp"
  43 #include "interpreter/rewriter.hpp"
  44 #include "jvmtifiles/jvmti.h"
  45 #include "logging/log.hpp"
  46 #include "logging/logMessage.hpp"
  47 #include "logging/logStream.hpp"
  48 #include "memory/allocation.inline.hpp"
  49 #include "memory/heapInspection.hpp"
  50 #include "memory/iterator.inline.hpp"
  51 #include "memory/metadataFactory.hpp"
  52 #include "memory/metaspaceClosure.hpp"
  53 #include "memory/metaspaceShared.hpp"
  54 #include "memory/oopFactory.hpp"
  55 #include "memory/resourceArea.hpp"
  56 #include "memory/universe.hpp"
  57 #include "oops/fieldStreams.inline.hpp"
  58 #include "oops/constantPool.hpp"
  59 #include "oops/instanceClassLoaderKlass.hpp"
  60 #include "oops/instanceKlass.inline.hpp"
  61 #include "oops/instanceMirrorKlass.hpp"
  62 #include "oops/instanceOop.hpp"
  63 #include "oops/klass.inline.hpp"
  64 #include "oops/method.hpp"
  65 #include "oops/oop.inline.hpp"
  66 #include "oops/symbol.hpp"
  67 #include "prims/jvmtiExport.hpp"
  68 #include "prims/jvmtiRedefineClasses.hpp"
  69 #include "prims/jvmtiThreadState.hpp"
  70 #include "prims/methodComparator.hpp"
  71 #include "runtime/atomic.hpp"
  72 #include "runtime/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   _static_field_size(parser.static_field_size()),
 440   _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
 441   _itable_len(parser.itable_size()),
 442   _init_thread(NULL),
 443   _init_state(allocated),
 444   _reference_type(parser.reference_type())
 445 {
 446   set_vtable_length(parser.vtable_size());
 447   set_kind(kind);
 448   set_access_flags(parser.access_flags());
 449   set_is_unsafe_anonymous(parser.is_unsafe_anonymous());
 450   set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
 451                                                     false));
 452 
 453   assert(NULL == _methods, "underlying memory not zeroed?");
 454   assert(is_instance_klass(), "is layout incorrect?");
 455   assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
 456 
 457   if (Arguments::is_dumping_archive()) {
 458     SystemDictionaryShared::init_dumptime_info(this);
 459   }
 460 
 461   // Set biased locking bit for all instances of this class; it will be
 462   // cleared if revocation occurs too often for this type
 463   if (UseBiasedLocking && BiasedLocking::enabled()) {
 464     set_prototype_header(markWord::biased_locking_prototype());
 465   }
 466 }
 467 
 468 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 469                                        Array<Method*>* methods) {
 470   if (methods != NULL && methods != Universe::the_empty_method_array() &&
 471       !methods->is_shared()) {
 472     for (int i = 0; i < methods->length(); i++) {
 473       Method* method = methods->at(i);
 474       if (method == NULL) continue;  // maybe null if error processing
 475       // Only want to delete methods that are not executing for RedefineClasses.
 476       // The previous version will point to them so they're not totally dangling
 477       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 478       MetadataFactory::free_metadata(loader_data, method);
 479     }
 480     MetadataFactory::free_array<Method*>(loader_data, methods);
 481   }
 482 }
 483 
 484 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 485                                           const Klass* super_klass,
 486                                           Array<InstanceKlass*>* local_interfaces,
 487                                           Array<InstanceKlass*>* transitive_interfaces) {
 488   // Only deallocate transitive interfaces if not empty, same as super class
 489   // or same as local interfaces.  See code in parseClassFile.
 490   Array<InstanceKlass*>* ti = transitive_interfaces;
 491   if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
 492     // check that the interfaces don't come from super class
 493     Array<InstanceKlass*>* sti = (super_klass == NULL) ? NULL :
 494                     InstanceKlass::cast(super_klass)->transitive_interfaces();
 495     if (ti != sti && ti != NULL && !ti->is_shared()) {
 496       MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
 497     }
 498   }
 499 
 500   // local interfaces can be empty
 501   if (local_interfaces != Universe::the_empty_instance_klass_array() &&
 502       local_interfaces != NULL && !local_interfaces->is_shared()) {
 503     MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
 504   }
 505 }
 506 
 507 // This function deallocates the metadata and C heap pointers that the
 508 // InstanceKlass points to.
 509 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 510 
 511   // Orphan the mirror first, CMS thinks it's still live.
 512   if (java_mirror() != NULL) {
 513     java_lang_Class::set_klass(java_mirror(), NULL);
 514   }
 515 
 516   // Also remove mirror from handles
 517   loader_data->remove_handle(_java_mirror);
 518 
 519   // Need to take this class off the class loader data list.
 520   loader_data->remove_class(this);
 521 
 522   // The array_klass for this class is created later, after error handling.
 523   // For class redefinition, we keep the original class so this scratch class
 524   // doesn't have an array class.  Either way, assert that there is nothing
 525   // to deallocate.
 526   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
 527 
 528   // Release C heap allocated data that this might point to, which includes
 529   // reference counting symbol names.
 530   release_C_heap_structures();
 531 
 532   deallocate_methods(loader_data, methods());
 533   set_methods(NULL);
 534 
 535   if (method_ordering() != NULL &&
 536       method_ordering() != Universe::the_empty_int_array() &&
 537       !method_ordering()->is_shared()) {
 538     MetadataFactory::free_array<int>(loader_data, method_ordering());
 539   }
 540   set_method_ordering(NULL);
 541 
 542   // default methods can be empty
 543   if (default_methods() != NULL &&
 544       default_methods() != Universe::the_empty_method_array() &&
 545       !default_methods()->is_shared()) {
 546     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 547   }
 548   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 549   set_default_methods(NULL);
 550 
 551   // default methods vtable indices can be empty
 552   if (default_vtable_indices() != NULL &&
 553       !default_vtable_indices()->is_shared()) {
 554     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 555   }
 556   set_default_vtable_indices(NULL);
 557 
 558 
 559   // This array is in Klass, but remove it with the InstanceKlass since
 560   // this place would be the only caller and it can share memory with transitive
 561   // interfaces.
 562   if (secondary_supers() != NULL &&
 563       secondary_supers() != Universe::the_empty_klass_array() &&
 564       // see comments in compute_secondary_supers about the following cast
 565       (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
 566       !secondary_supers()->is_shared()) {
 567     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 568   }
 569   set_secondary_supers(NULL);
 570 
 571   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 572   set_transitive_interfaces(NULL);
 573   set_local_interfaces(NULL);
 574 
 575   if (fields() != NULL && !fields()->is_shared()) {
 576     MetadataFactory::free_array<jushort>(loader_data, fields());
 577   }
 578   set_fields(NULL, 0);
 579 
 580   // If a method from a redefined class is using this constant pool, don't
 581   // delete it, yet.  The new class's previous version will point to this.
 582   if (constants() != NULL) {
 583     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 584     if (!constants()->is_shared()) {
 585       MetadataFactory::free_metadata(loader_data, constants());
 586     }
 587     // Delete any cached resolution errors for the constant pool
 588     SystemDictionary::delete_resolution_error(constants());
 589 
 590     set_constants(NULL);
 591   }
 592 
 593   if (inner_classes() != NULL &&
 594       inner_classes() != Universe::the_empty_short_array() &&
 595       !inner_classes()->is_shared()) {
 596     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 597   }
 598   set_inner_classes(NULL);
 599 
 600   if (nest_members() != NULL &&
 601       nest_members() != Universe::the_empty_short_array() &&
 602       !nest_members()->is_shared()) {
 603     MetadataFactory::free_array<jushort>(loader_data, nest_members());
 604   }
 605   set_nest_members(NULL);
 606 
 607   // We should deallocate the Annotations instance if it's not in shared spaces.
 608   if (annotations() != NULL && !annotations()->is_shared()) {
 609     MetadataFactory::free_metadata(loader_data, annotations());
 610   }
 611   set_annotations(NULL);
 612 
 613   if (Arguments::is_dumping_archive()) {
 614     SystemDictionaryShared::remove_dumptime_info(this);
 615   }
 616 }
 617 
 618 bool InstanceKlass::should_be_initialized() const {
 619   return !is_initialized();
 620 }
 621 
 622 klassItable InstanceKlass::itable() const {
 623   return klassItable(const_cast<InstanceKlass*>(this));
 624 }
 625 
 626 void InstanceKlass::eager_initialize(Thread *thread) {
 627   if (!EagerInitialization) return;
 628 
 629   if (this->is_not_initialized()) {
 630     // abort if the the class has a class initializer
 631     if (this->class_initializer() != NULL) return;
 632 
 633     // abort if it is java.lang.Object (initialization is handled in genesis)
 634     Klass* super_klass = super();
 635     if (super_klass == NULL) return;
 636 
 637     // abort if the super class should be initialized
 638     if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
 639 
 640     // call body to expose the this pointer
 641     eager_initialize_impl();
 642   }
 643 }
 644 
 645 // JVMTI spec thinks there are signers and protection domain in the
 646 // instanceKlass.  These accessors pretend these fields are there.
 647 // The hprof specification also thinks these fields are in InstanceKlass.
 648 oop InstanceKlass::protection_domain() const {
 649   // return the protection_domain from the mirror
 650   return java_lang_Class::protection_domain(java_mirror());
 651 }
 652 
 653 // To remove these from requires an incompatible change and CCC request.
 654 objArrayOop InstanceKlass::signers() const {
 655   // return the signers from the mirror
 656   return java_lang_Class::signers(java_mirror());
 657 }
 658 
 659 oop InstanceKlass::init_lock() const {
 660   // return the init lock from the mirror
 661   oop lock = java_lang_Class::init_lock(java_mirror());
 662   // Prevent reordering with any access of initialization state
 663   OrderAccess::loadload();
 664   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
 665          "only fully initialized state can have a null lock");
 666   return lock;
 667 }
 668 
 669 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 670 // threads to get this lock will see a null lock and will not lock.
 671 // That's okay because they all check for initialized state after getting
 672 // the lock and return.
 673 void InstanceKlass::fence_and_clear_init_lock() {
 674   // make sure previous stores are all done, notably the init_state.
 675   OrderAccess::storestore();
 676   java_lang_Class::set_init_lock(java_mirror(), NULL);
 677   assert(!is_not_initialized(), "class must be initialized now");
 678 }
 679 
 680 void InstanceKlass::eager_initialize_impl() {
 681   EXCEPTION_MARK;
 682   HandleMark hm(THREAD);
 683   Handle h_init_lock(THREAD, init_lock());
 684   ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 685 
 686   // abort if someone beat us to the initialization
 687   if (!is_not_initialized()) return;  // note: not equivalent to is_initialized()
 688 
 689   ClassState old_state = init_state();
 690   link_class_impl(THREAD);
 691   if (HAS_PENDING_EXCEPTION) {
 692     CLEAR_PENDING_EXCEPTION;
 693     // Abort if linking the class throws an exception.
 694 
 695     // Use a test to avoid redundantly resetting the state if there's
 696     // no change.  Set_init_state() asserts that state changes make
 697     // progress, whereas here we might just be spinning in place.
 698     if (old_state != _init_state)
 699       set_init_state(old_state);
 700   } else {
 701     // linking successfull, mark class as initialized
 702     set_init_state(fully_initialized);
 703     fence_and_clear_init_lock();
 704     // trace
 705     if (log_is_enabled(Info, class, init)) {
 706       ResourceMark rm(THREAD);
 707       log_info(class, init)("[Initialized %s without side effects]", external_name());
 708     }
 709   }
 710 }
 711 
 712 
 713 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 714 // process. The step comments refers to the procedure described in that section.
 715 // Note: implementation moved to static method to expose the this pointer.
 716 void InstanceKlass::initialize(TRAPS) {
 717   if (this->should_be_initialized()) {
 718     initialize_impl(CHECK);
 719     // Note: at this point the class may be initialized
 720     //       OR it may be in the state of being initialized
 721     //       in case of recursive initialization!
 722   } else {
 723     assert(is_initialized(), "sanity check");
 724   }
 725 }
 726 
 727 
 728 bool InstanceKlass::verify_code(TRAPS) {
 729   // 1) Verify the bytecodes
 730   return Verifier::verify(this, should_verify_class(), THREAD);
 731 }
 732 
 733 void InstanceKlass::link_class(TRAPS) {
 734   assert(is_loaded(), "must be loaded");
 735   if (!is_linked()) {
 736     link_class_impl(CHECK);
 737   }
 738 }
 739 
 740 // Called to verify that a class can link during initialization, without
 741 // throwing a VerifyError.
 742 bool InstanceKlass::link_class_or_fail(TRAPS) {
 743   assert(is_loaded(), "must be loaded");
 744   if (!is_linked()) {
 745     link_class_impl(CHECK_false);
 746   }
 747   return is_linked();
 748 }
 749 
 750 bool InstanceKlass::link_class_impl(TRAPS) {
 751   if (DumpSharedSpaces && is_in_error_state()) {
 752     // This is for CDS dumping phase only -- we use the in_error_state to indicate that
 753     // the class has failed verification. Throwing the NoClassDefFoundError here is just
 754     // a convenient way to stop repeat attempts to verify the same (bad) class.
 755     //
 756     // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
 757     // if we are executing Java code. This is not a problem for CDS dumping phase since
 758     // it doesn't execute any Java code.
 759     ResourceMark rm(THREAD);
 760     Exceptions::fthrow(THREAD_AND_LOCATION,
 761                        vmSymbols::java_lang_NoClassDefFoundError(),
 762                        "Class %s, or one of its supertypes, failed class initialization",
 763                        external_name());
 764     return false;
 765   }
 766   // return if already verified
 767   if (is_linked()) {
 768     return true;
 769   }
 770 
 771   // Timing
 772   // timer handles recursion
 773   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 774   JavaThread* jt = (JavaThread*)THREAD;
 775 
 776   // link super class before linking this class
 777   Klass* super_klass = super();
 778   if (super_klass != NULL) {
 779     if (super_klass->is_interface()) {  // check if super class is an interface
 780       ResourceMark rm(THREAD);
 781       Exceptions::fthrow(
 782         THREAD_AND_LOCATION,
 783         vmSymbols::java_lang_IncompatibleClassChangeError(),
 784         "class %s has interface %s as super class",
 785         external_name(),
 786         super_klass->external_name()
 787       );
 788       return false;
 789     }
 790 
 791     InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
 792     ik_super->link_class_impl(CHECK_false);
 793   }
 794 
 795   // link all interfaces implemented by this class before linking this class
 796   Array<InstanceKlass*>* interfaces = local_interfaces();
 797   int num_interfaces = interfaces->length();
 798   for (int index = 0; index < num_interfaces; index++) {
 799     InstanceKlass* interk = interfaces->at(index);
 800     interk->link_class_impl(CHECK_false);
 801   }
 802 
 803   // in case the class is linked in the process of linking its superclasses
 804   if (is_linked()) {
 805     return true;
 806   }
 807 
 808   // trace only the link time for this klass that includes
 809   // the verification time
 810   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 811                              ClassLoader::perf_class_link_selftime(),
 812                              ClassLoader::perf_classes_linked(),
 813                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 814                              jt->get_thread_stat()->perf_timers_addr(),
 815                              PerfClassTraceTime::CLASS_LINK);
 816 
 817   // verification & rewriting
 818   {
 819     HandleMark hm(THREAD);
 820     Handle h_init_lock(THREAD, init_lock());
 821     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 822     // rewritten will have been set if loader constraint error found
 823     // on an earlier link attempt
 824     // don't verify or rewrite if already rewritten
 825     //
 826 
 827     if (!is_linked()) {
 828       if (!is_rewritten()) {
 829         {
 830           bool verify_ok = verify_code(THREAD);
 831           if (!verify_ok) {
 832             return false;
 833           }
 834         }
 835 
 836         // Just in case a side-effect of verify linked this class already
 837         // (which can sometimes happen since the verifier loads classes
 838         // using custom class loaders, which are free to initialize things)
 839         if (is_linked()) {
 840           return true;
 841         }
 842 
 843         // also sets rewritten
 844         rewrite_class(CHECK_false);
 845       } else if (is_shared()) {
 846         SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
 847       }
 848 
 849       // relocate jsrs and link methods after they are all rewritten
 850       link_methods(CHECK_false);
 851 
 852       // Initialize the vtable and interface table after
 853       // methods have been rewritten since rewrite may
 854       // fabricate new Method*s.
 855       // also does loader constraint checking
 856       //
 857       // initialize_vtable and initialize_itable need to be rerun for
 858       // a shared class if the class is not loaded by the NULL classloader.
 859       ClassLoaderData * loader_data = class_loader_data();
 860       if (!(is_shared() &&
 861             loader_data->is_the_null_class_loader_data())) {
 862         vtable().initialize_vtable(true, CHECK_false);
 863         itable().initialize_itable(true, CHECK_false);
 864       }
 865 #ifdef ASSERT
 866       else {
 867         vtable().verify(tty, true);
 868         // In case itable verification is ever added.
 869         // itable().verify(tty, true);
 870       }
 871 #endif
 872       set_init_state(linked);
 873       if (JvmtiExport::should_post_class_prepare()) {
 874         Thread *thread = THREAD;
 875         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 876         JvmtiExport::post_class_prepare((JavaThread *) thread, this);
 877       }
 878     }
 879   }
 880   return true;
 881 }
 882 
 883 // Rewrite the byte codes of all of the methods of a class.
 884 // The rewriter must be called exactly once. Rewriting must happen after
 885 // verification but before the first method of the class is executed.
 886 void InstanceKlass::rewrite_class(TRAPS) {
 887   assert(is_loaded(), "must be loaded");
 888   if (is_rewritten()) {
 889     assert(is_shared(), "rewriting an unshared class?");
 890     return;
 891   }
 892   Rewriter::rewrite(this, CHECK);
 893   set_rewritten();
 894 }
 895 
 896 // Now relocate and link method entry points after class is rewritten.
 897 // This is outside is_rewritten flag. In case of an exception, it can be
 898 // executed more than once.
 899 void InstanceKlass::link_methods(TRAPS) {
 900   int len = methods()->length();
 901   for (int i = len-1; i >= 0; i--) {
 902     methodHandle m(THREAD, methods()->at(i));
 903 
 904     // Set up method entry points for compiler and interpreter    .
 905     m->link_method(m, CHECK);
 906   }
 907 }
 908 
 909 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
 910 void InstanceKlass::initialize_super_interfaces(TRAPS) {
 911   assert (has_nonstatic_concrete_methods(), "caller should have checked this");
 912   for (int i = 0; i < local_interfaces()->length(); ++i) {
 913     InstanceKlass* ik = local_interfaces()->at(i);
 914 
 915     // Initialization is depth first search ie. we start with top of the inheritance tree
 916     // has_nonstatic_concrete_methods drives searching superinterfaces since it
 917     // means has_nonstatic_concrete_methods in its superinterface hierarchy
 918     if (ik->has_nonstatic_concrete_methods()) {
 919       ik->initialize_super_interfaces(CHECK);
 920     }
 921 
 922     // Only initialize() interfaces that "declare" concrete methods.
 923     if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
 924       ik->initialize(CHECK);
 925     }
 926   }
 927 }
 928 
 929 void InstanceKlass::initialize_impl(TRAPS) {
 930   HandleMark hm(THREAD);
 931 
 932   // Make sure klass is linked (verified) before initialization
 933   // A class could already be verified, since it has been reflected upon.
 934   link_class(CHECK);
 935 
 936   DTRACE_CLASSINIT_PROBE(required, -1);
 937 
 938   bool wait = false;
 939 
 940   assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
 941   JavaThread* jt = (JavaThread*)THREAD;
 942 
 943   // refer to the JVM book page 47 for description of steps
 944   // Step 1
 945   {
 946     Handle h_init_lock(THREAD, init_lock());
 947     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 948 
 949     // Step 2
 950     // If we were to use wait() instead of waitInterruptibly() then
 951     // we might end up throwing IE from link/symbol resolution sites
 952     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
 953     while (is_being_initialized() && !is_reentrant_initialization(jt)) {
 954       wait = true;
 955       jt->set_class_to_be_initialized(this);
 956       ol.wait_uninterruptibly(jt);
 957       jt->set_class_to_be_initialized(NULL);
 958     }
 959 
 960     // Step 3
 961     if (is_being_initialized() && is_reentrant_initialization(jt)) {
 962       DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
 963       return;
 964     }
 965 
 966     // Step 4
 967     if (is_initialized()) {
 968       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
 969       return;
 970     }
 971 
 972     // Step 5
 973     if (is_in_error_state()) {
 974       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
 975       ResourceMark rm(THREAD);
 976       const char* desc = "Could not initialize class ";
 977       const char* className = external_name();
 978       size_t msglen = strlen(desc) + strlen(className) + 1;
 979       char* message = NEW_RESOURCE_ARRAY(char, msglen);
 980       if (NULL == message) {
 981         // Out of memory: can't create detailed error message
 982           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
 983       } else {
 984         jio_snprintf(message, msglen, "%s%s", desc, className);
 985           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
 986       }
 987     }
 988 
 989     // Step 6
 990     set_init_state(being_initialized);
 991     set_init_thread(jt);
 992   }
 993 
 994   // Step 7
 995   // Next, if C is a class rather than an interface, initialize it's super class and super
 996   // interfaces.
 997   if (!is_interface()) {
 998     Klass* super_klass = super();
 999     if (super_klass != NULL && super_klass->should_be_initialized()) {
1000       super_klass->initialize(THREAD);
1001     }
1002     // If C implements any interface that declares a non-static, concrete method,
1003     // the initialization of C triggers initialization of its super interfaces.
1004     // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1005     // having a superinterface that declares, non-static, concrete methods
1006     if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1007       initialize_super_interfaces(THREAD);
1008     }
1009 
1010     // If any exceptions, complete abruptly, throwing the same exception as above.
1011     if (HAS_PENDING_EXCEPTION) {
1012       Handle e(THREAD, PENDING_EXCEPTION);
1013       CLEAR_PENDING_EXCEPTION;
1014       {
1015         EXCEPTION_MARK;
1016         // Locks object, set state, and notify all waiting threads
1017         set_initialization_state_and_notify(initialization_error, THREAD);
1018         CLEAR_PENDING_EXCEPTION;
1019       }
1020       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1021       THROW_OOP(e());
1022     }
1023   }
1024 
1025 
1026   // Look for aot compiled methods for this klass, including class initializer.
1027   AOTLoader::load_for_klass(this, THREAD);
1028 
1029   // Step 8
1030   {
1031     DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1032     // Timer includes any side effects of class initialization (resolution,
1033     // etc), but not recursive entry into call_class_initializer().
1034     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1035                              ClassLoader::perf_class_init_selftime(),
1036                              ClassLoader::perf_classes_inited(),
1037                              jt->get_thread_stat()->perf_recursion_counts_addr(),
1038                              jt->get_thread_stat()->perf_timers_addr(),
1039                              PerfClassTraceTime::CLASS_CLINIT);
1040     call_class_initializer(THREAD);
1041   }
1042 
1043   // Step 9
1044   if (!HAS_PENDING_EXCEPTION) {
1045     set_initialization_state_and_notify(fully_initialized, CHECK);
1046     {
1047       debug_only(vtable().verify(tty, true);)
1048     }
1049   }
1050   else {
1051     // Step 10 and 11
1052     Handle e(THREAD, PENDING_EXCEPTION);
1053     CLEAR_PENDING_EXCEPTION;
1054     // JVMTI has already reported the pending exception
1055     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1056     JvmtiExport::clear_detected_exception(jt);
1057     {
1058       EXCEPTION_MARK;
1059       set_initialization_state_and_notify(initialization_error, THREAD);
1060       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
1061       // JVMTI has already reported the pending exception
1062       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1063       JvmtiExport::clear_detected_exception(jt);
1064     }
1065     DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1066     if (e->is_a(SystemDictionary::Error_klass())) {
1067       THROW_OOP(e());
1068     } else {
1069       JavaCallArguments args(e);
1070       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1071                 vmSymbols::throwable_void_signature(),
1072                 &args);
1073     }
1074   }
1075   DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1076 }
1077 
1078 
1079 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1080   Handle h_init_lock(THREAD, init_lock());
1081   if (h_init_lock() != NULL) {
1082     ObjectLocker ol(h_init_lock, THREAD);
1083     set_init_thread(NULL); // reset _init_thread before changing _init_state
1084     set_init_state(state);
1085     fence_and_clear_init_lock();
1086     ol.notify_all(CHECK);
1087   } else {
1088     assert(h_init_lock() != NULL, "The initialization state should never be set twice");
1089     set_init_thread(NULL); // reset _init_thread before changing _init_state
1090     set_init_state(state);
1091   }
1092 }
1093 
1094 Klass* InstanceKlass::implementor() const {
1095   Klass* volatile* k = adr_implementor();
1096   if (k == NULL) {
1097     return NULL;
1098   } else {
1099     // This load races with inserts, and therefore needs acquire.
1100     Klass* kls = Atomic::load_acquire(k);
1101     if (kls != NULL && !kls->is_loader_alive()) {
1102       return NULL;  // don't return unloaded class
1103     } else {
1104       return kls;
1105     }
1106   }
1107 }
1108 
1109 
1110 void InstanceKlass::set_implementor(Klass* k) {
1111   assert_locked_or_safepoint(Compile_lock);
1112   assert(is_interface(), "not interface");
1113   Klass* volatile* addr = adr_implementor();
1114   assert(addr != NULL, "null addr");
1115   if (addr != NULL) {
1116     Atomic::release_store(addr, k);
1117   }
1118 }
1119 
1120 int  InstanceKlass::nof_implementors() const {
1121   Klass* k = implementor();
1122   if (k == NULL) {
1123     return 0;
1124   } else if (k != this) {
1125     return 1;
1126   } else {
1127     return 2;
1128   }
1129 }
1130 
1131 // The embedded _implementor field can only record one implementor.
1132 // When there are more than one implementors, the _implementor field
1133 // is set to the interface Klass* itself. Following are the possible
1134 // values for the _implementor field:
1135 //   NULL                  - no implementor
1136 //   implementor Klass*    - one implementor
1137 //   self                  - more than one implementor
1138 //
1139 // The _implementor field only exists for interfaces.
1140 void InstanceKlass::add_implementor(Klass* k) {
1141   assert_lock_strong(Compile_lock);
1142   assert(is_interface(), "not interface");
1143   // Filter out my subinterfaces.
1144   // (Note: Interfaces are never on the subklass list.)
1145   if (InstanceKlass::cast(k)->is_interface()) return;
1146 
1147   // Filter out subclasses whose supers already implement me.
1148   // (Note: CHA must walk subclasses of direct implementors
1149   // in order to locate indirect implementors.)
1150   Klass* sk = k->super();
1151   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
1152     // We only need to check one immediate superclass, since the
1153     // implements_interface query looks at transitive_interfaces.
1154     // Any supers of the super have the same (or fewer) transitive_interfaces.
1155     return;
1156 
1157   Klass* ik = implementor();
1158   if (ik == NULL) {
1159     set_implementor(k);
1160   } else if (ik != this) {
1161     // There is already an implementor. Use itself as an indicator of
1162     // more than one implementors.
1163     set_implementor(this);
1164   }
1165 
1166   // The implementor also implements the transitive_interfaces
1167   for (int index = 0; index < local_interfaces()->length(); index++) {
1168     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
1169   }
1170 }
1171 
1172 void InstanceKlass::init_implementor() {
1173   if (is_interface()) {
1174     set_implementor(NULL);
1175   }
1176 }
1177 
1178 
1179 void InstanceKlass::process_interfaces(Thread *thread) {
1180   // link this class into the implementors list of every interface it implements
1181   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1182     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1183     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
1184     assert(interf->is_interface(), "expected interface");
1185     interf->add_implementor(this);
1186   }
1187 }
1188 
1189 bool InstanceKlass::can_be_primary_super_slow() const {
1190   if (is_interface())
1191     return false;
1192   else
1193     return Klass::can_be_primary_super_slow();
1194 }
1195 
1196 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1197                                                                Array<InstanceKlass*>* transitive_interfaces) {
1198   // The secondaries are the implemented interfaces.
1199   Array<InstanceKlass*>* interfaces = transitive_interfaces;
1200   int num_secondaries = num_extra_slots + interfaces->length();
1201   if (num_secondaries == 0) {
1202     // Must share this for correct bootstrapping!
1203     set_secondary_supers(Universe::the_empty_klass_array());
1204     return NULL;
1205   } else if (num_extra_slots == 0) {
1206     // The secondary super list is exactly the same as the transitive interfaces, so
1207     // let's use it instead of making a copy.
1208     // Redefine classes has to be careful not to delete this!
1209     // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1210     // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1211     set_secondary_supers((Array<Klass*>*)(address)interfaces);
1212     return NULL;
1213   } else {
1214     // Copy transitive interfaces to a temporary growable array to be constructed
1215     // into the secondary super list with extra slots.
1216     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1217     for (int i = 0; i < interfaces->length(); i++) {
1218       secondaries->push(interfaces->at(i));
1219     }
1220     return secondaries;
1221   }
1222 }
1223 
1224 bool InstanceKlass::implements_interface(Klass* k) const {
1225   if (this == k) return true;
1226   assert(k->is_interface(), "should be an interface class");
1227   for (int i = 0; i < transitive_interfaces()->length(); i++) {
1228     if (transitive_interfaces()->at(i) == k) {
1229       return true;
1230     }
1231   }
1232   return false;
1233 }
1234 
1235 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1236   // Verify direct super interface
1237   if (this == k) return true;
1238   assert(k->is_interface(), "should be an interface class");
1239   for (int i = 0; i < local_interfaces()->length(); i++) {
1240     if (local_interfaces()->at(i) == k) {
1241       return true;
1242     }
1243   }
1244   return false;
1245 }
1246 
1247 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1248   check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1249   int size = objArrayOopDesc::object_size(length);
1250   Klass* ak = array_klass(n, CHECK_NULL);
1251   objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1252                                                                 /* do_zero */ true, CHECK_NULL);
1253   return o;
1254 }
1255 
1256 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1257   if (TraceFinalizerRegistration) {
1258     tty->print("Registered ");
1259     i->print_value_on(tty);
1260     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1261   }
1262   instanceHandle h_i(THREAD, i);
1263   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1264   JavaValue result(T_VOID);
1265   JavaCallArguments args(h_i);
1266   methodHandle mh (THREAD, Universe::finalizer_register_method());
1267   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1268   return h_i();
1269 }
1270 
1271 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1272   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1273   int size = size_helper();  // Query before forming handle.
1274 
1275   instanceOop i;
1276 
1277   i = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1278   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1279     i = register_finalizer(i, CHECK_NULL);
1280   }
1281   return i;
1282 }
1283 
1284 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1285   return instanceHandle(THREAD, allocate_instance(THREAD));
1286 }
1287 
1288 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1289   if (is_interface() || is_abstract()) {
1290     ResourceMark rm(THREAD);
1291     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1292               : vmSymbols::java_lang_InstantiationException(), external_name());
1293   }
1294   if (this == SystemDictionary::Class_klass()) {
1295     ResourceMark rm(THREAD);
1296     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1297               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1298   }
1299 }
1300 
1301 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1302   // Need load-acquire for lock-free read
1303   if (array_klasses_acquire() == NULL) {
1304     if (or_null) return NULL;
1305 
1306     ResourceMark rm;
1307     JavaThread *jt = (JavaThread *)THREAD;
1308     {
1309       // Atomic creation of array_klasses
1310       MutexLocker ma(MultiArray_lock, THREAD);
1311 
1312       // Check if update has already taken place
1313       if (array_klasses() == NULL) {
1314         Klass*    k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1315         // use 'release' to pair with lock-free load
1316         release_set_array_klasses(k);
1317       }
1318     }
1319   }
1320   // _this will always be set at this point
1321   ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1322   if (or_null) {
1323     return oak->array_klass_or_null(n);
1324   }
1325   return oak->array_klass(n, THREAD);
1326 }
1327 
1328 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1329   return array_klass_impl(or_null, 1, THREAD);
1330 }
1331 
1332 static int call_class_initializer_counter = 0;   // for debugging
1333 
1334 Method* InstanceKlass::class_initializer() const {
1335   Method* clinit = find_method(
1336       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1337   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1338     return clinit;
1339   }
1340   return NULL;
1341 }
1342 
1343 void InstanceKlass::call_class_initializer(TRAPS) {
1344   if (ReplayCompiles &&
1345       (ReplaySuppressInitializers == 1 ||
1346        (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1347     // Hide the existence of the initializer for the purpose of replaying the compile
1348     return;
1349   }
1350 
1351   methodHandle h_method(THREAD, class_initializer());
1352   assert(!is_initialized(), "we cannot initialize twice");
1353   LogTarget(Info, class, init) lt;
1354   if (lt.is_enabled()) {
1355     ResourceMark rm;
1356     LogStream ls(lt);
1357     ls.print("%d Initializing ", call_class_initializer_counter++);
1358     name()->print_value_on(&ls);
1359     ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1360   }
1361   if (h_method() != NULL) {
1362     JavaCallArguments args; // No arguments
1363     JavaValue result(T_VOID);
1364     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1365   }
1366 }
1367 
1368 
1369 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1370   InterpreterOopMap* entry_for) {
1371   // Lazily create the _oop_map_cache at first request
1372   // Lock-free access requires load_acquire.
1373   OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1374   if (oop_map_cache == NULL) {
1375     MutexLocker x(OopMapCacheAlloc_lock);
1376     // Check if _oop_map_cache was allocated while we were waiting for this lock
1377     if ((oop_map_cache = _oop_map_cache) == NULL) {
1378       oop_map_cache = new OopMapCache();
1379       // Ensure _oop_map_cache is stable, since it is examined without a lock
1380       Atomic::release_store(&_oop_map_cache, oop_map_cache);
1381     }
1382   }
1383   // _oop_map_cache is constant after init; lookup below does its own locking.
1384   oop_map_cache->lookup(method, bci, entry_for);
1385 }
1386 
1387 
1388 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1389   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1390     Symbol* f_name = fs.name();
1391     Symbol* f_sig  = fs.signature();
1392     if (f_name == name && f_sig == sig) {
1393       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1394       return true;
1395     }
1396   }
1397   return false;
1398 }
1399 
1400 
1401 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1402   const int n = local_interfaces()->length();
1403   for (int i = 0; i < n; i++) {
1404     Klass* intf1 = local_interfaces()->at(i);
1405     assert(intf1->is_interface(), "just checking type");
1406     // search for field in current interface
1407     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1408       assert(fd->is_static(), "interface field must be static");
1409       return intf1;
1410     }
1411     // search for field in direct superinterfaces
1412     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1413     if (intf2 != NULL) return intf2;
1414   }
1415   // otherwise field lookup fails
1416   return NULL;
1417 }
1418 
1419 
1420 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1421   // search order according to newest JVM spec (5.4.3.2, p.167).
1422   // 1) search for field in current klass
1423   if (find_local_field(name, sig, fd)) {
1424     return const_cast<InstanceKlass*>(this);
1425   }
1426   // 2) search for field recursively in direct superinterfaces
1427   { Klass* intf = find_interface_field(name, sig, fd);
1428     if (intf != NULL) return intf;
1429   }
1430   // 3) apply field lookup recursively if superclass exists
1431   { Klass* supr = super();
1432     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1433   }
1434   // 4) otherwise field lookup fails
1435   return NULL;
1436 }
1437 
1438 
1439 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, 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     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1444   }
1445   // 2) search for field recursively in direct superinterfaces
1446   if (is_static) {
1447     Klass* intf = find_interface_field(name, sig, fd);
1448     if (intf != NULL) return intf;
1449   }
1450   // 3) apply field lookup recursively if superclass exists
1451   { Klass* supr = super();
1452     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1453   }
1454   // 4) otherwise field lookup fails
1455   return NULL;
1456 }
1457 
1458 
1459 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1460   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1461     if (fs.offset() == offset) {
1462       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1463       if (fd->is_static() == is_static) return true;
1464     }
1465   }
1466   return false;
1467 }
1468 
1469 
1470 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1471   Klass* klass = const_cast<InstanceKlass*>(this);
1472   while (klass != NULL) {
1473     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1474       return true;
1475     }
1476     klass = klass->super();
1477   }
1478   return false;
1479 }
1480 
1481 
1482 void InstanceKlass::methods_do(void f(Method* method)) {
1483   // Methods aren't stable until they are loaded.  This can be read outside
1484   // a lock through the ClassLoaderData for profiling
1485   if (!is_loaded()) {
1486     return;
1487   }
1488 
1489   int len = methods()->length();
1490   for (int index = 0; index < len; index++) {
1491     Method* m = methods()->at(index);
1492     assert(m->is_method(), "must be method");
1493     f(m);
1494   }
1495 }
1496 
1497 
1498 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1499   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1500     if (fs.access_flags().is_static()) {
1501       fieldDescriptor& fd = fs.field_descriptor();
1502       cl->do_field(&fd);
1503     }
1504   }
1505 }
1506 
1507 
1508 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1509   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1510     if (fs.access_flags().is_static()) {
1511       fieldDescriptor& fd = fs.field_descriptor();
1512       f(&fd, mirror, CHECK);
1513     }
1514   }
1515 }
1516 
1517 
1518 static int compare_fields_by_offset(int* a, int* b) {
1519   return a[0] - b[0];
1520 }
1521 
1522 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1523   InstanceKlass* super = superklass();
1524   if (super != NULL) {
1525     super->do_nonstatic_fields(cl);
1526   }
1527   fieldDescriptor fd;
1528   int length = java_fields_count();
1529   // In DebugInfo nonstatic fields are sorted by offset.
1530   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1531   int j = 0;
1532   for (int i = 0; i < length; i += 1) {
1533     fd.reinitialize(this, i);
1534     if (!fd.is_static()) {
1535       fields_sorted[j + 0] = fd.offset();
1536       fields_sorted[j + 1] = i;
1537       j += 2;
1538     }
1539   }
1540   if (j > 0) {
1541     length = j;
1542     // _sort_Fn is defined in growableArray.hpp.
1543     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1544     for (int i = 0; i < length; i += 2) {
1545       fd.reinitialize(this, fields_sorted[i + 1]);
1546       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1547       cl->do_field(&fd);
1548     }
1549   }
1550   FREE_C_HEAP_ARRAY(int, fields_sorted);
1551 }
1552 
1553 
1554 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1555   if (array_klasses() != NULL)
1556     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1557 }
1558 
1559 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1560   if (array_klasses() != NULL)
1561     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1562 }
1563 
1564 #ifdef ASSERT
1565 static int linear_search(const Array<Method*>* methods,
1566                          const Symbol* name,
1567                          const Symbol* signature) {
1568   const int len = methods->length();
1569   for (int index = 0; index < len; index++) {
1570     const Method* const m = methods->at(index);
1571     assert(m->is_method(), "must be method");
1572     if (m->signature() == signature && m->name() == name) {
1573        return index;
1574     }
1575   }
1576   return -1;
1577 }
1578 #endif
1579 
1580 bool InstanceKlass::_disable_method_binary_search = false;
1581 
1582 int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1583   int len = methods->length();
1584   int l = 0;
1585   int h = len - 1;
1586 
1587   if (_disable_method_binary_search) {
1588     // At the final stage of dynamic dumping, the methods array may not be sorted
1589     // by ascending addresses of their names, so we can't use binary search anymore.
1590     // However, methods with the same name are still laid out consecutively inside the
1591     // methods array, so let's look for the first one that matches.
1592     assert(DynamicDumpSharedSpaces, "must be");
1593     while (l <= h) {
1594       Method* m = methods->at(l);
1595       if (m->name() == name) {
1596         return l;
1597       }
1598       l ++;
1599     }
1600     return -1;
1601   }
1602 
1603   // methods are sorted by ascending addresses of their names, so do binary search
1604   while (l <= h) {
1605     int mid = (l + h) >> 1;
1606     Method* m = methods->at(mid);
1607     assert(m->is_method(), "must be method");
1608     int res = m->name()->fast_compare(name);
1609     if (res == 0) {
1610       return mid;
1611     } else if (res < 0) {
1612       l = mid + 1;
1613     } else {
1614       h = mid - 1;
1615     }
1616   }
1617   return -1;
1618 }
1619 
1620 // find_method looks up the name/signature in the local methods array
1621 Method* InstanceKlass::find_method(const Symbol* name,
1622                                    const Symbol* signature) const {
1623   return find_method_impl(name, signature, find_overpass, find_static, find_private);
1624 }
1625 
1626 Method* InstanceKlass::find_method_impl(const Symbol* name,
1627                                         const Symbol* signature,
1628                                         OverpassLookupMode overpass_mode,
1629                                         StaticLookupMode static_mode,
1630                                         PrivateLookupMode private_mode) const {
1631   return InstanceKlass::find_method_impl(methods(),
1632                                          name,
1633                                          signature,
1634                                          overpass_mode,
1635                                          static_mode,
1636                                          private_mode);
1637 }
1638 
1639 // find_instance_method looks up the name/signature in the local methods array
1640 // and skips over static methods
1641 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1642                                             const Symbol* name,
1643                                             const Symbol* signature,
1644                                             PrivateLookupMode private_mode) {
1645   Method* const meth = InstanceKlass::find_method_impl(methods,
1646                                                  name,
1647                                                  signature,
1648                                                  find_overpass,
1649                                                  skip_static,
1650                                                  private_mode);
1651   assert(((meth == NULL) || !meth->is_static()),
1652     "find_instance_method should have skipped statics");
1653   return meth;
1654 }
1655 
1656 // find_instance_method looks up the name/signature in the local methods array
1657 // and skips over static methods
1658 Method* InstanceKlass::find_instance_method(const Symbol* name,
1659                                             const Symbol* signature,
1660                                             PrivateLookupMode private_mode) const {
1661   return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1662 }
1663 
1664 // Find looks up the name/signature in the local methods array
1665 // and filters on the overpass, static and private flags
1666 // This returns the first one found
1667 // note that the local methods array can have up to one overpass, one static
1668 // and one instance (private or not) with the same name/signature
1669 Method* InstanceKlass::find_local_method(const Symbol* name,
1670                                          const Symbol* signature,
1671                                          OverpassLookupMode overpass_mode,
1672                                          StaticLookupMode static_mode,
1673                                          PrivateLookupMode private_mode) const {
1674   return InstanceKlass::find_method_impl(methods(),
1675                                          name,
1676                                          signature,
1677                                          overpass_mode,
1678                                          static_mode,
1679                                          private_mode);
1680 }
1681 
1682 // Find looks up the name/signature in the local methods array
1683 // and filters on the overpass, static and private flags
1684 // This returns the first one found
1685 // note that the local methods array can have up to one overpass, one static
1686 // and one instance (private or not) with the same name/signature
1687 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1688                                          const Symbol* name,
1689                                          const Symbol* signature,
1690                                          OverpassLookupMode overpass_mode,
1691                                          StaticLookupMode static_mode,
1692                                          PrivateLookupMode private_mode) {
1693   return InstanceKlass::find_method_impl(methods,
1694                                          name,
1695                                          signature,
1696                                          overpass_mode,
1697                                          static_mode,
1698                                          private_mode);
1699 }
1700 
1701 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1702                                    const Symbol* name,
1703                                    const Symbol* signature) {
1704   return InstanceKlass::find_method_impl(methods,
1705                                          name,
1706                                          signature,
1707                                          find_overpass,
1708                                          find_static,
1709                                          find_private);
1710 }
1711 
1712 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1713                                         const Symbol* name,
1714                                         const Symbol* signature,
1715                                         OverpassLookupMode overpass_mode,
1716                                         StaticLookupMode static_mode,
1717                                         PrivateLookupMode private_mode) {
1718   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1719   return hit >= 0 ? methods->at(hit): NULL;
1720 }
1721 
1722 // true if method matches signature and conforms to skipping_X conditions.
1723 static bool method_matches(const Method* m,
1724                            const Symbol* signature,
1725                            bool skipping_overpass,
1726                            bool skipping_static,
1727                            bool skipping_private) {
1728   return ((m->signature() == signature) &&
1729     (!skipping_overpass || !m->is_overpass()) &&
1730     (!skipping_static || !m->is_static()) &&
1731     (!skipping_private || !m->is_private()));
1732 }
1733 
1734 // Used directly for default_methods to find the index into the
1735 // default_vtable_indices, and indirectly by find_method
1736 // find_method_index looks in the local methods array to return the index
1737 // of the matching name/signature. If, overpass methods are being ignored,
1738 // the search continues to find a potential non-overpass match.  This capability
1739 // is important during method resolution to prefer a static method, for example,
1740 // over an overpass method.
1741 // There is the possibility in any _method's array to have the same name/signature
1742 // for a static method, an overpass method and a local instance method
1743 // To correctly catch a given method, the search criteria may need
1744 // to explicitly skip the other two. For local instance methods, it
1745 // is often necessary to skip private methods
1746 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1747                                      const Symbol* name,
1748                                      const Symbol* signature,
1749                                      OverpassLookupMode overpass_mode,
1750                                      StaticLookupMode static_mode,
1751                                      PrivateLookupMode private_mode) {
1752   const bool skipping_overpass = (overpass_mode == skip_overpass);
1753   const bool skipping_static = (static_mode == skip_static);
1754   const bool skipping_private = (private_mode == skip_private);
1755   const int hit = quick_search(methods, name);
1756   if (hit != -1) {
1757     const Method* const m = methods->at(hit);
1758 
1759     // Do linear search to find matching signature.  First, quick check
1760     // for common case, ignoring overpasses if requested.
1761     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1762       return hit;
1763     }
1764 
1765     // search downwards through overloaded methods
1766     int i;
1767     for (i = hit - 1; i >= 0; --i) {
1768         const Method* const m = methods->at(i);
1769         assert(m->is_method(), "must be method");
1770         if (m->name() != name) {
1771           break;
1772         }
1773         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1774           return i;
1775         }
1776     }
1777     // search upwards
1778     for (i = hit + 1; i < methods->length(); ++i) {
1779         const Method* const m = methods->at(i);
1780         assert(m->is_method(), "must be method");
1781         if (m->name() != name) {
1782           break;
1783         }
1784         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1785           return i;
1786         }
1787     }
1788     // not found
1789 #ifdef ASSERT
1790     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1791       linear_search(methods, name, signature);
1792     assert(-1 == index, "binary search should have found entry %d", index);
1793 #endif
1794   }
1795   return -1;
1796 }
1797 
1798 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1799   return find_method_by_name(methods(), name, end);
1800 }
1801 
1802 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1803                                        const Symbol* name,
1804                                        int* end_ptr) {
1805   assert(end_ptr != NULL, "just checking");
1806   int start = quick_search(methods, name);
1807   int end = start + 1;
1808   if (start != -1) {
1809     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1810     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1811     *end_ptr = end;
1812     return start;
1813   }
1814   return -1;
1815 }
1816 
1817 // uncached_lookup_method searches both the local class methods array and all
1818 // superclasses methods arrays, skipping any overpass methods in superclasses,
1819 // and possibly skipping private methods.
1820 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1821                                               const Symbol* signature,
1822                                               OverpassLookupMode overpass_mode,
1823                                               PrivateLookupMode private_mode) const {
1824   OverpassLookupMode overpass_local_mode = overpass_mode;
1825   const Klass* klass = this;
1826   while (klass != NULL) {
1827     Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1828                                                                         signature,
1829                                                                         overpass_local_mode,
1830                                                                         find_static,
1831                                                                         private_mode);
1832     if (method != NULL) {
1833       return method;
1834     }
1835     klass = klass->super();
1836     overpass_local_mode = skip_overpass;   // Always ignore overpass methods in superclasses
1837   }
1838   return NULL;
1839 }
1840 
1841 #ifdef ASSERT
1842 // search through class hierarchy and return true if this class or
1843 // one of the superclasses was redefined
1844 bool InstanceKlass::has_redefined_this_or_super() const {
1845   const Klass* klass = this;
1846   while (klass != NULL) {
1847     if (InstanceKlass::cast(klass)->has_been_redefined()) {
1848       return true;
1849     }
1850     klass = klass->super();
1851   }
1852   return false;
1853 }
1854 #endif
1855 
1856 // lookup a method in the default methods list then in all transitive interfaces
1857 // Do NOT return private or static methods
1858 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1859                                                          Symbol* signature) const {
1860   Method* m = NULL;
1861   if (default_methods() != NULL) {
1862     m = find_method(default_methods(), name, signature);
1863   }
1864   // Look up interfaces
1865   if (m == NULL) {
1866     m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1867   }
1868   return m;
1869 }
1870 
1871 // lookup a method in all the interfaces that this class implements
1872 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1873 // They should only be found in the initial InterfaceMethodRef
1874 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1875                                                        Symbol* signature,
1876                                                        DefaultsLookupMode defaults_mode) const {
1877   Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1878   int num_ifs = all_ifs->length();
1879   InstanceKlass *ik = NULL;
1880   for (int i = 0; i < num_ifs; i++) {
1881     ik = all_ifs->at(i);
1882     Method* m = ik->lookup_method(name, signature);
1883     if (m != NULL && m->is_public() && !m->is_static() &&
1884         ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1885       return m;
1886     }
1887   }
1888   return NULL;
1889 }
1890 
1891 /* jni_id_for_impl for jfieldIds only */
1892 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1893   MutexLocker ml(JfieldIdCreation_lock);
1894   // Retry lookup after we got the lock
1895   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1896   if (probe == NULL) {
1897     // Slow case, allocate new static field identifier
1898     probe = new JNIid(this, offset, jni_ids());
1899     set_jni_ids(probe);
1900   }
1901   return probe;
1902 }
1903 
1904 
1905 /* jni_id_for for jfieldIds only */
1906 JNIid* InstanceKlass::jni_id_for(int offset) {
1907   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1908   if (probe == NULL) {
1909     probe = jni_id_for_impl(offset);
1910   }
1911   return probe;
1912 }
1913 
1914 u2 InstanceKlass::enclosing_method_data(int offset) const {
1915   const Array<jushort>* const inner_class_list = inner_classes();
1916   if (inner_class_list == NULL) {
1917     return 0;
1918   }
1919   const int length = inner_class_list->length();
1920   if (length % inner_class_next_offset == 0) {
1921     return 0;
1922   }
1923   const int index = length - enclosing_method_attribute_size;
1924   assert(offset < enclosing_method_attribute_size, "invalid offset");
1925   return inner_class_list->at(index + offset);
1926 }
1927 
1928 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1929                                                  u2 method_index) {
1930   Array<jushort>* inner_class_list = inner_classes();
1931   assert (inner_class_list != NULL, "_inner_classes list is not set up");
1932   int length = inner_class_list->length();
1933   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1934     int index = length - enclosing_method_attribute_size;
1935     inner_class_list->at_put(
1936       index + enclosing_method_class_index_offset, class_index);
1937     inner_class_list->at_put(
1938       index + enclosing_method_method_index_offset, method_index);
1939   }
1940 }
1941 
1942 // Lookup or create a jmethodID.
1943 // This code is called by the VMThread and JavaThreads so the
1944 // locking has to be done very carefully to avoid deadlocks
1945 // and/or other cache consistency problems.
1946 //
1947 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
1948   size_t idnum = (size_t)method_h->method_idnum();
1949   jmethodID* jmeths = methods_jmethod_ids_acquire();
1950   size_t length = 0;
1951   jmethodID id = NULL;
1952 
1953   // We use a double-check locking idiom here because this cache is
1954   // performance sensitive. In the normal system, this cache only
1955   // transitions from NULL to non-NULL which is safe because we use
1956   // release_set_methods_jmethod_ids() to advertise the new cache.
1957   // A partially constructed cache should never be seen by a racing
1958   // thread. We also use release_store() to save a new jmethodID
1959   // in the cache so a partially constructed jmethodID should never be
1960   // seen either. Cache reads of existing jmethodIDs proceed without a
1961   // lock, but cache writes of a new jmethodID requires uniqueness and
1962   // creation of the cache itself requires no leaks so a lock is
1963   // generally acquired in those two cases.
1964   //
1965   // If the RedefineClasses() API has been used, then this cache can
1966   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1967   // Cache creation requires no leaks and we require safety between all
1968   // cache accesses and freeing of the old cache so a lock is generally
1969   // acquired when the RedefineClasses() API has been used.
1970 
1971   if (jmeths != NULL) {
1972     // the cache already exists
1973     if (!idnum_can_increment()) {
1974       // the cache can't grow so we can just get the current values
1975       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1976     } else {
1977       // cache can grow so we have to be more careful
1978       if (Threads::number_of_threads() == 0 ||
1979           SafepointSynchronize::is_at_safepoint()) {
1980         // we're single threaded or at a safepoint - no locking needed
1981         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1982       } else {
1983         MutexLocker ml(JmethodIdCreation_lock);
1984         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1985       }
1986     }
1987   }
1988   // implied else:
1989   // we need to allocate a cache so default length and id values are good
1990 
1991   if (jmeths == NULL ||   // no cache yet
1992       length <= idnum ||  // cache is too short
1993       id == NULL) {       // cache doesn't contain entry
1994 
1995     // This function can be called by the VMThread so we have to do all
1996     // things that might block on a safepoint before grabbing the lock.
1997     // Otherwise, we can deadlock with the VMThread or have a cache
1998     // consistency issue. These vars keep track of what we might have
1999     // to free after the lock is dropped.
2000     jmethodID  to_dealloc_id     = NULL;
2001     jmethodID* to_dealloc_jmeths = NULL;
2002 
2003     // may not allocate new_jmeths or use it if we allocate it
2004     jmethodID* new_jmeths = NULL;
2005     if (length <= idnum) {
2006       // allocate a new cache that might be used
2007       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
2008       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
2009       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
2010       // cache size is stored in element[0], other elements offset by one
2011       new_jmeths[0] = (jmethodID)size;
2012     }
2013 
2014     // allocate a new jmethodID that might be used
2015     jmethodID new_id = NULL;
2016     if (method_h->is_old() && !method_h->is_obsolete()) {
2017       // The method passed in is old (but not obsolete), we need to use the current version
2018       Method* current_method = method_with_idnum((int)idnum);
2019       assert(current_method != NULL, "old and but not obsolete, so should exist");
2020       new_id = Method::make_jmethod_id(class_loader_data(), current_method);
2021     } else {
2022       // It is the current version of the method or an obsolete method,
2023       // use the version passed in
2024       new_id = Method::make_jmethod_id(class_loader_data(), method_h());
2025     }
2026 
2027     if (Threads::number_of_threads() == 0 ||
2028         SafepointSynchronize::is_at_safepoint()) {
2029       // we're single threaded or at a safepoint - no locking needed
2030       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2031                                           &to_dealloc_id, &to_dealloc_jmeths);
2032     } else {
2033       MutexLocker ml(JmethodIdCreation_lock);
2034       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2035                                           &to_dealloc_id, &to_dealloc_jmeths);
2036     }
2037 
2038     // The lock has been dropped so we can free resources.
2039     // Free up either the old cache or the new cache if we allocated one.
2040     if (to_dealloc_jmeths != NULL) {
2041       FreeHeap(to_dealloc_jmeths);
2042     }
2043     // free up the new ID since it wasn't needed
2044     if (to_dealloc_id != NULL) {
2045       Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
2046     }
2047   }
2048   return id;
2049 }
2050 
2051 // Figure out how many jmethodIDs haven't been allocated, and make
2052 // sure space for them is pre-allocated.  This makes getting all
2053 // method ids much, much faster with classes with more than 8
2054 // methods, and has a *substantial* effect on performance with jvmti
2055 // code that loads all jmethodIDs for all classes.
2056 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2057   int new_jmeths = 0;
2058   int length = methods()->length();
2059   for (int index = start_offset; index < length; index++) {
2060     Method* m = methods()->at(index);
2061     jmethodID id = m->find_jmethod_id_or_null();
2062     if (id == NULL) {
2063       new_jmeths++;
2064     }
2065   }
2066   if (new_jmeths != 0) {
2067     Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2068   }
2069 }
2070 
2071 // Common code to fetch the jmethodID from the cache or update the
2072 // cache with the new jmethodID. This function should never do anything
2073 // that causes the caller to go to a safepoint or we can deadlock with
2074 // the VMThread or have cache consistency issues.
2075 //
2076 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
2077             size_t idnum, jmethodID new_id,
2078             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
2079             jmethodID** to_dealloc_jmeths_p) {
2080   assert(new_id != NULL, "sanity check");
2081   assert(to_dealloc_id_p != NULL, "sanity check");
2082   assert(to_dealloc_jmeths_p != NULL, "sanity check");
2083   assert(Threads::number_of_threads() == 0 ||
2084          SafepointSynchronize::is_at_safepoint() ||
2085          JmethodIdCreation_lock->owned_by_self(), "sanity check");
2086 
2087   // reacquire the cache - we are locked, single threaded or at a safepoint
2088   jmethodID* jmeths = methods_jmethod_ids_acquire();
2089   jmethodID  id     = NULL;
2090   size_t     length = 0;
2091 
2092   if (jmeths == NULL ||                         // no cache yet
2093       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
2094     if (jmeths != NULL) {
2095       // copy any existing entries from the old cache
2096       for (size_t index = 0; index < length; index++) {
2097         new_jmeths[index+1] = jmeths[index+1];
2098       }
2099       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
2100     }
2101     release_set_methods_jmethod_ids(jmeths = new_jmeths);
2102   } else {
2103     // fetch jmethodID (if any) from the existing cache
2104     id = jmeths[idnum+1];
2105     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
2106   }
2107   if (id == NULL) {
2108     // No matching jmethodID in the existing cache or we have a new
2109     // cache or we just grew the cache. This cache write is done here
2110     // by the first thread to win the foot race because a jmethodID
2111     // needs to be unique once it is generally available.
2112     id = new_id;
2113 
2114     // The jmethodID cache can be read while unlocked so we have to
2115     // make sure the new jmethodID is complete before installing it
2116     // in the cache.
2117     Atomic::release_store(&jmeths[idnum+1], id);
2118   } else {
2119     *to_dealloc_id_p = new_id; // save new id for later delete
2120   }
2121   return id;
2122 }
2123 
2124 
2125 // Common code to get the jmethodID cache length and the jmethodID
2126 // value at index idnum if there is one.
2127 //
2128 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
2129        size_t idnum, size_t *length_p, jmethodID* id_p) {
2130   assert(cache != NULL, "sanity check");
2131   assert(length_p != NULL, "sanity check");
2132   assert(id_p != NULL, "sanity check");
2133 
2134   // cache size is stored in element[0], other elements offset by one
2135   *length_p = (size_t)cache[0];
2136   if (*length_p <= idnum) {  // cache is too short
2137     *id_p = NULL;
2138   } else {
2139     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
2140   }
2141 }
2142 
2143 
2144 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
2145 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2146   size_t idnum = (size_t)method->method_idnum();
2147   jmethodID* jmeths = methods_jmethod_ids_acquire();
2148   size_t length;                                // length assigned as debugging crumb
2149   jmethodID id = NULL;
2150   if (jmeths != NULL &&                         // If there is a cache
2151       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
2152     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
2153   }
2154   return id;
2155 }
2156 
2157 inline DependencyContext InstanceKlass::dependencies() {
2158   DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2159   return dep_context;
2160 }
2161 
2162 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
2163   return dependencies().mark_dependent_nmethods(changes);
2164 }
2165 
2166 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2167   dependencies().add_dependent_nmethod(nm);
2168 }
2169 
2170 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
2171   dependencies().remove_dependent_nmethod(nm);
2172 }
2173 
2174 void InstanceKlass::clean_dependency_context() {
2175   dependencies().clean_unloading_dependents();
2176 }
2177 
2178 #ifndef PRODUCT
2179 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2180   dependencies().print_dependent_nmethods(verbose);
2181 }
2182 
2183 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2184   return dependencies().is_dependent_nmethod(nm);
2185 }
2186 #endif //PRODUCT
2187 
2188 void InstanceKlass::clean_weak_instanceklass_links() {
2189   clean_implementors_list();
2190   clean_method_data();
2191 }
2192 
2193 void InstanceKlass::clean_implementors_list() {
2194   assert(is_loader_alive(), "this klass should be live");
2195   if (is_interface()) {
2196     assert (ClassUnloading, "only called for ClassUnloading");
2197     for (;;) {
2198       // Use load_acquire due to competing with inserts
2199       Klass* impl = Atomic::load_acquire(adr_implementor());
2200       if (impl != NULL && !impl->is_loader_alive()) {
2201         // NULL this field, might be an unloaded klass or NULL
2202         Klass* volatile* klass = adr_implementor();
2203         if (Atomic::cmpxchg((Klass*)NULL, klass, impl) == impl) {
2204           // Successfully unlinking implementor.
2205           if (log_is_enabled(Trace, class, unload)) {
2206             ResourceMark rm;
2207             log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2208           }
2209           return;
2210         }
2211       } else {
2212         return;
2213       }
2214     }
2215   }
2216 }
2217 
2218 void InstanceKlass::clean_method_data() {
2219   for (int m = 0; m < methods()->length(); m++) {
2220     MethodData* mdo = methods()->at(m)->method_data();
2221     if (mdo != NULL) {
2222       MutexLocker ml(SafepointSynchronize::is_at_safepoint() ? NULL : mdo->extra_data_lock());
2223       mdo->clean_method_data(/*always_clean*/false);
2224     }
2225   }
2226 }
2227 
2228 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
2229   if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
2230     ResourceMark rm;
2231     log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
2232     return false;
2233   }
2234 
2235   Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
2236   if (local_interfaces != NULL) {
2237     int length = local_interfaces->length();
2238     for (int i = 0; i < length; i++) {
2239       InstanceKlass* intf = local_interfaces->at(i);
2240       if (!intf->has_passed_fingerprint_check()) {
2241         ResourceMark rm;
2242         log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
2243         return false;
2244       }
2245     }
2246   }
2247 
2248   return true;
2249 }
2250 
2251 bool InstanceKlass::should_store_fingerprint(bool is_unsafe_anonymous) {
2252 #if INCLUDE_AOT
2253   // We store the fingerprint into the InstanceKlass only in the following 2 cases:
2254   if (CalculateClassFingerprint) {
2255     // (1) We are running AOT to generate a shared library.
2256     return true;
2257   }
2258   if (Arguments::is_dumping_archive()) {
2259     // (2) We are running -Xshare:dump or -XX:ArchiveClassesAtExit to create a shared archive
2260     return true;
2261   }
2262   if (UseAOT && is_unsafe_anonymous) {
2263     // (3) We are using AOT code from a shared library and see an unsafe anonymous class
2264     return true;
2265   }
2266 #endif
2267 
2268   // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
2269   // but do not store the 64-bit fingerprint to save space.
2270   return false;
2271 }
2272 
2273 bool InstanceKlass::has_stored_fingerprint() const {
2274 #if INCLUDE_AOT
2275   return should_store_fingerprint() || is_shared();
2276 #else
2277   return false;
2278 #endif
2279 }
2280 
2281 uint64_t InstanceKlass::get_stored_fingerprint() const {
2282   address adr = adr_fingerprint();
2283   if (adr != NULL) {
2284     return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
2285   }
2286   return 0;
2287 }
2288 
2289 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
2290   address adr = adr_fingerprint();
2291   if (adr != NULL) {
2292     Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2293 
2294     ResourceMark rm;
2295     log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2296   }
2297 }
2298 
2299 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2300   Klass::metaspace_pointers_do(it);
2301 
2302   if (log_is_enabled(Trace, cds)) {
2303     ResourceMark rm;
2304     log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2305   }
2306 
2307   it->push(&_annotations);
2308   it->push((Klass**)&_array_klasses);
2309   it->push(&_constants);
2310   it->push(&_inner_classes);
2311   it->push(&_array_name);
2312 #if INCLUDE_JVMTI
2313   it->push(&_previous_versions);
2314 #endif
2315   it->push(&_methods);
2316   it->push(&_default_methods);
2317   it->push(&_local_interfaces);
2318   it->push(&_transitive_interfaces);
2319   it->push(&_method_ordering);
2320   it->push(&_default_vtable_indices);
2321   it->push(&_fields);
2322 
2323   if (itable_length() > 0) {
2324     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2325     int method_table_offset_in_words = ioe->offset()/wordSize;
2326     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2327                          / itableOffsetEntry::size();
2328 
2329     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2330       if (ioe->interface_klass() != NULL) {
2331         it->push(ioe->interface_klass_addr());
2332         itableMethodEntry* ime = ioe->first_method_entry(this);
2333         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2334         for (int index = 0; index < n; index ++) {
2335           it->push(ime[index].method_addr());
2336         }
2337       }
2338     }
2339   }
2340 
2341   it->push(&_nest_members);
2342 }
2343 
2344 void InstanceKlass::remove_unshareable_info() {
2345   Klass::remove_unshareable_info();
2346 
2347   if (is_in_error_state()) {
2348     // Classes are attempted to link during dumping and may fail,
2349     // but these classes are still in the dictionary and class list in CLD.
2350     // Check in_error state first because in_error is > linked state, so
2351     // is_linked() is true.
2352     // If there's a linking error, there is nothing else to remove.
2353     return;
2354   }
2355 
2356   // Reset to the 'allocated' state to prevent any premature accessing to
2357   // a shared class at runtime while the class is still being loaded and
2358   // restored. A class' init_state is set to 'loaded' at runtime when it's
2359   // being added to class hierarchy (see SystemDictionary:::add_to_hierarchy()).
2360   _init_state = allocated;
2361 
2362   { // Otherwise this needs to take out the Compile_lock.
2363     assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2364     init_implementor();
2365   }
2366 
2367   constants()->remove_unshareable_info();
2368 
2369   for (int i = 0; i < methods()->length(); i++) {
2370     Method* m = methods()->at(i);
2371     m->remove_unshareable_info();
2372   }
2373 
2374   // do array classes also.
2375   if (array_klasses() != NULL) {
2376     array_klasses()->remove_unshareable_info();
2377   }
2378 
2379   // These are not allocated from metaspace. They are safe to set to NULL.
2380   _source_debug_extension = NULL;
2381   _dep_context = NULL;
2382   _osr_nmethods_head = NULL;
2383 #if INCLUDE_JVMTI
2384   _breakpoints = NULL;
2385   _previous_versions = NULL;
2386   _cached_class_file = NULL;
2387   _jvmti_cached_class_field_map = NULL;
2388 #endif
2389 
2390   _init_thread = NULL;
2391   _methods_jmethod_ids = NULL;
2392   _jni_ids = NULL;
2393   _oop_map_cache = NULL;
2394   // clear _nest_host to ensure re-load at runtime
2395   _nest_host = NULL;
2396   _package_entry = NULL;
2397   _dep_context_last_cleaned = 0;
2398 }
2399 
2400 void InstanceKlass::remove_java_mirror() {
2401   Klass::remove_java_mirror();
2402 
2403   // do array classes also.
2404   if (array_klasses() != NULL) {
2405     array_klasses()->remove_java_mirror();
2406   }
2407 }
2408 
2409 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2410   // SystemDictionary::add_to_hierarchy() sets the init_state to loaded
2411   // before the InstanceKlass is added to the SystemDictionary. Make
2412   // sure the current state is <loaded.
2413   assert(!is_loaded(), "invalid init state");
2414   set_package(loader_data, CHECK);
2415   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2416 
2417   Array<Method*>* methods = this->methods();
2418   int num_methods = methods->length();
2419   for (int index = 0; index < num_methods; ++index) {
2420     methods->at(index)->restore_unshareable_info(CHECK);
2421   }
2422   if (JvmtiExport::has_redefined_a_class()) {
2423     // Reinitialize vtable because RedefineClasses may have changed some
2424     // entries in this vtable for super classes so the CDS vtable might
2425     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2426     // vtables in the shared system dictionary, only the main one.
2427     // It also redefines the itable too so fix that too.
2428     vtable().initialize_vtable(false, CHECK);
2429     itable().initialize_itable(false, CHECK);
2430   }
2431 
2432   // restore constant pool resolved references
2433   constants()->restore_unshareable_info(CHECK);
2434 
2435   if (array_klasses() != NULL) {
2436     // Array classes have null protection domain.
2437     // --> see ArrayKlass::complete_create_array_klass()
2438     array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2439   }
2440 
2441   // Initialize current biased locking state.
2442   if (UseBiasedLocking && BiasedLocking::enabled()) {
2443     set_prototype_header(markWord::biased_locking_prototype());
2444   }
2445 }
2446 
2447 // returns true IFF is_in_error_state() has been changed as a result of this call.
2448 bool InstanceKlass::check_sharing_error_state() {
2449   assert(DumpSharedSpaces, "should only be called during dumping");
2450   bool old_state = is_in_error_state();
2451 
2452   if (!is_in_error_state()) {
2453     bool bad = false;
2454     for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2455       if (sup->is_in_error_state()) {
2456         bad = true;
2457         break;
2458       }
2459     }
2460     if (!bad) {
2461       Array<InstanceKlass*>* interfaces = transitive_interfaces();
2462       for (int i = 0; i < interfaces->length(); i++) {
2463         InstanceKlass* iface = interfaces->at(i);
2464         if (iface->is_in_error_state()) {
2465           bad = true;
2466           break;
2467         }
2468       }
2469     }
2470 
2471     if (bad) {
2472       set_in_error_state();
2473     }
2474   }
2475 
2476   return (old_state != is_in_error_state());
2477 }
2478 
2479 void InstanceKlass::set_class_loader_type(s2 loader_type) {
2480   switch (loader_type) {
2481   case ClassLoader::BOOT_LOADER:
2482     _misc_flags |= _misc_is_shared_boot_class;
2483     break;
2484   case ClassLoader::PLATFORM_LOADER:
2485     _misc_flags |= _misc_is_shared_platform_class;
2486     break;
2487   case ClassLoader::APP_LOADER:
2488     _misc_flags |= _misc_is_shared_app_class;
2489     break;
2490   default:
2491     ShouldNotReachHere();
2492     break;
2493   }
2494 }
2495 
2496 #if INCLUDE_JVMTI
2497 static void clear_all_breakpoints(Method* m) {
2498   m->clear_all_breakpoints();
2499 }
2500 #endif
2501 
2502 void InstanceKlass::unload_class(InstanceKlass* ik) {
2503   // Release dependencies.
2504   ik->dependencies().remove_all_dependents();
2505 
2506   // notify the debugger
2507   if (JvmtiExport::should_post_class_unload()) {
2508     JvmtiExport::post_class_unload(ik);
2509   }
2510 
2511   // notify ClassLoadingService of class unload
2512   ClassLoadingService::notify_class_unloaded(ik);
2513 
2514   if (Arguments::is_dumping_archive()) {
2515     SystemDictionaryShared::remove_dumptime_info(ik);
2516   }
2517 
2518   if (log_is_enabled(Info, class, unload)) {
2519     ResourceMark rm;
2520     log_info(class, unload)("unloading class %s " INTPTR_FORMAT, ik->external_name(), p2i(ik));
2521   }
2522 
2523   Events::log_class_unloading(Thread::current(), ik);
2524 
2525 #if INCLUDE_JFR
2526   assert(ik != NULL, "invariant");
2527   EventClassUnload event;
2528   event.set_unloadedClass(ik);
2529   event.set_definingClassLoader(ik->class_loader_data());
2530   event.commit();
2531 #endif
2532 }
2533 
2534 static void method_release_C_heap_structures(Method* m) {
2535   m->release_C_heap_structures();
2536 }
2537 
2538 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2539   // Clean up C heap
2540   ik->release_C_heap_structures();
2541   ik->constants()->release_C_heap_structures();
2542 
2543   // Deallocate and call destructors for MDO mutexes
2544   ik->methods_do(method_release_C_heap_structures);
2545 
2546 }
2547 
2548 void InstanceKlass::release_C_heap_structures() {
2549   // Can't release the constant pool here because the constant pool can be
2550   // deallocated separately from the InstanceKlass for default methods and
2551   // redefine classes.
2552 
2553   // Deallocate oop map cache
2554   if (_oop_map_cache != NULL) {
2555     delete _oop_map_cache;
2556     _oop_map_cache = NULL;
2557   }
2558 
2559   // Deallocate JNI identifiers for jfieldIDs
2560   JNIid::deallocate(jni_ids());
2561   set_jni_ids(NULL);
2562 
2563   jmethodID* jmeths = methods_jmethod_ids_acquire();
2564   if (jmeths != (jmethodID*)NULL) {
2565     release_set_methods_jmethod_ids(NULL);
2566     FreeHeap(jmeths);
2567   }
2568 
2569   assert(_dep_context == NULL,
2570          "dependencies should already be cleaned");
2571 
2572 #if INCLUDE_JVMTI
2573   // Deallocate breakpoint records
2574   if (breakpoints() != 0x0) {
2575     methods_do(clear_all_breakpoints);
2576     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2577   }
2578 
2579   // deallocate the cached class file
2580   if (_cached_class_file != NULL) {
2581     os::free(_cached_class_file);
2582     _cached_class_file = NULL;
2583   }
2584 #endif
2585 
2586   // Decrement symbol reference counts associated with the unloaded class.
2587   if (_name != NULL) _name->decrement_refcount();
2588   // unreference array name derived from this class name (arrays of an unloaded
2589   // class can't be referenced anymore).
2590   if (_array_name != NULL)  _array_name->decrement_refcount();
2591   FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2592 }
2593 
2594 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2595   if (array == NULL) {
2596     _source_debug_extension = NULL;
2597   } else {
2598     // Adding one to the attribute length in order to store a null terminator
2599     // character could cause an overflow because the attribute length is
2600     // already coded with an u4 in the classfile, but in practice, it's
2601     // unlikely to happen.
2602     assert((length+1) > length, "Overflow checking");
2603     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2604     for (int i = 0; i < length; i++) {
2605       sde[i] = array[i];
2606     }
2607     sde[length] = '\0';
2608     _source_debug_extension = sde;
2609   }
2610 }
2611 
2612 const char* InstanceKlass::signature_name() const {
2613   int hash_len = 0;
2614   char hash_buf[40];
2615 
2616   // If this is an unsafe anonymous class, append a hash to make the name unique
2617   if (is_unsafe_anonymous()) {
2618     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2619     jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2620     hash_len = (int)strlen(hash_buf);
2621   }
2622 
2623   // Get the internal name as a c string
2624   const char* src = (const char*) (name()->as_C_string());
2625   const int src_length = (int)strlen(src);
2626 
2627   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2628 
2629   // Add L as type indicator
2630   int dest_index = 0;
2631   dest[dest_index++] = JVM_SIGNATURE_CLASS;
2632 
2633   // Add the actual class name
2634   for (int src_index = 0; src_index < src_length; ) {
2635     dest[dest_index++] = src[src_index++];
2636   }
2637 
2638   // If we have a hash, append it
2639   for (int hash_index = 0; hash_index < hash_len; ) {
2640     dest[dest_index++] = hash_buf[hash_index++];
2641   }
2642 
2643   // Add the semicolon and the NULL
2644   dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
2645   dest[dest_index] = '\0';
2646   return dest;
2647 }
2648 
2649 // Used to obtain the package name from a fully qualified class name.
2650 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2651   if (name == NULL) {
2652     return NULL;
2653   } else {
2654     if (name->utf8_length() <= 0) {
2655       return NULL;
2656     }
2657     ResourceMark rm;
2658     const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2659     if (package_name == NULL) {
2660       return NULL;
2661     }
2662     Symbol* pkg_name = SymbolTable::new_symbol(package_name);
2663     return pkg_name;
2664   }
2665 }
2666 
2667 ModuleEntry* InstanceKlass::module() const {
2668   // For an unsafe anonymous class return the host class' module
2669   if (is_unsafe_anonymous()) {
2670     assert(unsafe_anonymous_host() != NULL, "unsafe anonymous class must have a host class");
2671     return unsafe_anonymous_host()->module();
2672   }
2673 
2674   // Class is in a named package
2675   if (!in_unnamed_package()) {
2676     return _package_entry->module();
2677   }
2678 
2679   // Class is in an unnamed package, return its loader's unnamed module
2680   return class_loader_data()->unnamed_module();
2681 }
2682 
2683 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2684 
2685   // ensure java/ packages only loaded by boot or platform builtin loaders
2686   check_prohibited_package(name(), loader_data, CHECK);
2687 
2688   TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2689 
2690   if (pkg_name != NULL && loader_data != NULL) {
2691 
2692     // Find in class loader's package entry table.
2693     _package_entry = loader_data->packages()->lookup_only(pkg_name);
2694 
2695     // If the package name is not found in the loader's package
2696     // entry table, it is an indication that the package has not
2697     // been defined. Consider it defined within the unnamed module.
2698     if (_package_entry == NULL) {
2699       ResourceMark rm;
2700 
2701       if (!ModuleEntryTable::javabase_defined()) {
2702         // Before java.base is defined during bootstrapping, define all packages in
2703         // the java.base module.  If a non-java.base package is erroneously placed
2704         // in the java.base module it will be caught later when java.base
2705         // is defined by ModuleEntryTable::verify_javabase_packages check.
2706         assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2707         _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2708       } else {
2709         assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2710         _package_entry = loader_data->packages()->lookup(pkg_name,
2711                                                          loader_data->unnamed_module());
2712       }
2713 
2714       // A package should have been successfully created
2715       assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2716              name()->as_C_string(), loader_data->loader_name_and_id());
2717     }
2718 
2719     if (log_is_enabled(Debug, module)) {
2720       ResourceMark rm;
2721       ModuleEntry* m = _package_entry->module();
2722       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2723                         external_name(),
2724                         pkg_name->as_C_string(),
2725                         loader_data->loader_name_and_id(),
2726                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2727     }
2728   } else {
2729     ResourceMark rm;
2730     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2731                       external_name(),
2732                       (loader_data != NULL) ? loader_data->loader_name_and_id() : "NULL",
2733                       UNNAMED_MODULE);
2734   }
2735 }
2736 
2737 
2738 // different versions of is_same_class_package
2739 
2740 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2741   oop classloader1 = this->class_loader();
2742   PackageEntry* classpkg1 = this->package();
2743   if (class2->is_objArray_klass()) {
2744     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2745   }
2746 
2747   oop classloader2;
2748   PackageEntry* classpkg2;
2749   if (class2->is_instance_klass()) {
2750     classloader2 = class2->class_loader();
2751     classpkg2 = class2->package();
2752   } else {
2753     assert(class2->is_typeArray_klass(), "should be type array");
2754     classloader2 = NULL;
2755     classpkg2 = NULL;
2756   }
2757 
2758   // Same package is determined by comparing class loader
2759   // and package entries. Both must be the same. This rule
2760   // applies even to classes that are defined in the unnamed
2761   // package, they still must have the same class loader.
2762   if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2763     return true;
2764   }
2765 
2766   return false;
2767 }
2768 
2769 // return true if this class and other_class are in the same package. Classloader
2770 // and classname information is enough to determine a class's package
2771 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2772                                           const Symbol* other_class_name) const {
2773   if (class_loader() != other_class_loader) {
2774     return false;
2775   }
2776   if (name()->fast_compare(other_class_name) == 0) {
2777      return true;
2778   }
2779 
2780   {
2781     ResourceMark rm;
2782 
2783     bool bad_class_name = false;
2784     const char* other_pkg =
2785       ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2786     if (bad_class_name) {
2787       return false;
2788     }
2789     // Check that package_from_name() returns NULL, not "", if there is no package.
2790     assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2791 
2792     const Symbol* const this_package_name =
2793       this->package() != NULL ? this->package()->name() : NULL;
2794 
2795     if (this_package_name == NULL || other_pkg == NULL) {
2796       // One of the two doesn't have a package.  Only return true if the other
2797       // one also doesn't have a package.
2798       return (const char*)this_package_name == other_pkg;
2799     }
2800 
2801     // Check if package is identical
2802     return this_package_name->equals(other_pkg);
2803   }
2804 }
2805 
2806 // Returns true iff super_method can be overridden by a method in targetclassname
2807 // See JLS 3rd edition 8.4.6.1
2808 // Assumes name-signature match
2809 // "this" is InstanceKlass of super_method which must exist
2810 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2811 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2812    // Private methods can not be overridden
2813    if (super_method->is_private()) {
2814      return false;
2815    }
2816    // If super method is accessible, then override
2817    if ((super_method->is_protected()) ||
2818        (super_method->is_public())) {
2819      return true;
2820    }
2821    // Package-private methods are not inherited outside of package
2822    assert(super_method->is_package_private(), "must be package private");
2823    return(is_same_class_package(targetclassloader(), targetclassname));
2824 }
2825 
2826 // Only boot and platform class loaders can define classes in "java/" packages.
2827 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2828                                              ClassLoaderData* loader_data,
2829                                              TRAPS) {
2830   if (!loader_data->is_boot_class_loader_data() &&
2831       !loader_data->is_platform_class_loader_data() &&
2832       class_name != NULL) {
2833     ResourceMark rm(THREAD);
2834     char* name = class_name->as_C_string();
2835     if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2836       TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2837       assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2838       name = pkg_name->as_C_string();
2839       const char* class_loader_name = loader_data->loader_name_and_id();
2840       StringUtils::replace_no_expand(name, "/", ".");
2841       const char* msg_text1 = "Class loader (instance of): ";
2842       const char* msg_text2 = " tried to load prohibited package name: ";
2843       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2844       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2845       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2846       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2847     }
2848   }
2849   return;
2850 }
2851 
2852 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2853   constantPoolHandle i_cp(THREAD, constants());
2854   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2855     int ioff = iter.inner_class_info_index();
2856     if (ioff != 0) {
2857       // Check to see if the name matches the class we're looking for
2858       // before attempting to find the class.
2859       if (i_cp->klass_name_at_matches(this, ioff)) {
2860         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2861         if (this == inner_klass) {
2862           *ooff = iter.outer_class_info_index();
2863           *noff = iter.inner_name_index();
2864           return true;
2865         }
2866       }
2867     }
2868   }
2869   return false;
2870 }
2871 
2872 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2873   InstanceKlass* outer_klass = NULL;
2874   *inner_is_member = false;
2875   int ooff = 0, noff = 0;
2876   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2877   if (has_inner_classes_attr) {
2878     constantPoolHandle i_cp(THREAD, constants());
2879     if (ooff != 0) {
2880       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2881       outer_klass = InstanceKlass::cast(ok);
2882       *inner_is_member = true;
2883     }
2884     if (NULL == outer_klass) {
2885       // It may be unsafe anonymous; try for that.
2886       int encl_method_class_idx = enclosing_method_class_index();
2887       if (encl_method_class_idx != 0) {
2888         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2889         outer_klass = InstanceKlass::cast(ok);
2890         *inner_is_member = false;
2891       }
2892     }
2893   }
2894 
2895   // If no inner class attribute found for this class.
2896   if (NULL == outer_klass) return NULL;
2897 
2898   // Throws an exception if outer klass has not declared k as an inner klass
2899   // We need evidence that each klass knows about the other, or else
2900   // the system could allow a spoof of an inner class to gain access rights.
2901   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2902   return outer_klass;
2903 }
2904 
2905 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2906   jint access = access_flags().as_int();
2907 
2908   // But check if it happens to be member class.
2909   InnerClassesIterator iter(this);
2910   for (; !iter.done(); iter.next()) {
2911     int ioff = iter.inner_class_info_index();
2912     // Inner class attribute can be zero, skip it.
2913     // Strange but true:  JVM spec. allows null inner class refs.
2914     if (ioff == 0) continue;
2915 
2916     // only look at classes that are already loaded
2917     // since we are looking for the flags for our self.
2918     Symbol* inner_name = constants()->klass_name_at(ioff);
2919     if (name() == inner_name) {
2920       // This is really a member class.
2921       access = iter.inner_access_flags();
2922       break;
2923     }
2924   }
2925   // Remember to strip ACC_SUPER bit
2926   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2927 }
2928 
2929 jint InstanceKlass::jvmti_class_status() const {
2930   jint result = 0;
2931 
2932   if (is_linked()) {
2933     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2934   }
2935 
2936   if (is_initialized()) {
2937     assert(is_linked(), "Class status is not consistent");
2938     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2939   }
2940   if (is_in_error_state()) {
2941     result |= JVMTI_CLASS_STATUS_ERROR;
2942   }
2943   return result;
2944 }
2945 
2946 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2947   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2948   int method_table_offset_in_words = ioe->offset()/wordSize;
2949   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2950                        / itableOffsetEntry::size();
2951 
2952   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2953     // If the interface isn't implemented by the receiver class,
2954     // the VM should throw IncompatibleClassChangeError.
2955     if (cnt >= nof_interfaces) {
2956       ResourceMark rm(THREAD);
2957       stringStream ss;
2958       bool same_module = (module() == holder->module());
2959       ss.print("Receiver class %s does not implement "
2960                "the interface %s defining the method to be called "
2961                "(%s%s%s)",
2962                external_name(), holder->external_name(),
2963                (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
2964                (same_module) ? "" : "; ",
2965                (same_module) ? "" : holder->class_in_module_of_loader());
2966       THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
2967     }
2968 
2969     Klass* ik = ioe->interface_klass();
2970     if (ik == holder) break;
2971   }
2972 
2973   itableMethodEntry* ime = ioe->first_method_entry(this);
2974   Method* m = ime[index].method();
2975   if (m == NULL) {
2976     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2977   }
2978   return m;
2979 }
2980 
2981 
2982 #if INCLUDE_JVMTI
2983 // update default_methods for redefineclasses for methods that are
2984 // not yet in the vtable due to concurrent subclass define and superinterface
2985 // redefinition
2986 // Note: those in the vtable, should have been updated via adjust_method_entries
2987 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
2988   // search the default_methods for uses of either obsolete or EMCP methods
2989   if (default_methods() != NULL) {
2990     for (int index = 0; index < default_methods()->length(); index ++) {
2991       Method* old_method = default_methods()->at(index);
2992       if (old_method == NULL || !old_method->is_old()) {
2993         continue; // skip uninteresting entries
2994       }
2995       assert(!old_method->is_deleted(), "default methods may not be deleted");
2996       Method* new_method = old_method->get_new_method();
2997       default_methods()->at_put(index, new_method);
2998 
2999       if (log_is_enabled(Info, redefine, class, update)) {
3000         ResourceMark rm;
3001         if (!(*trace_name_printed)) {
3002           log_info(redefine, class, update)
3003             ("adjust: klassname=%s default methods from name=%s",
3004              external_name(), old_method->method_holder()->external_name());
3005           *trace_name_printed = true;
3006         }
3007         log_debug(redefine, class, update, vtables)
3008           ("default method update: %s(%s) ",
3009            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3010       }
3011     }
3012   }
3013 }
3014 #endif // INCLUDE_JVMTI
3015 
3016 // On-stack replacement stuff
3017 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3018   assert_lock_strong(CompiledMethod_lock);
3019 #ifndef PRODUCT
3020   if (TieredCompilation) {
3021       nmethod * prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3022       assert(prev == NULL || !prev->is_in_use(),
3023       "redundunt OSR recompilation detected. memory leak in CodeCache!");
3024   }
3025 #endif
3026   // only one compilation can be active
3027   {
3028     assert(n->is_osr_method(), "wrong kind of nmethod");
3029     n->set_osr_link(osr_nmethods_head());
3030     set_osr_nmethods_head(n);
3031     // Raise the highest osr level if necessary
3032     if (TieredCompilation) {
3033       Method* m = n->method();
3034       m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
3035     }
3036   }
3037 
3038   // Get rid of the osr methods for the same bci that have lower levels.
3039   if (TieredCompilation) {
3040     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3041       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3042       if (inv != NULL && inv->is_in_use()) {
3043         inv->make_not_entrant();
3044       }
3045     }
3046   }
3047 }
3048 
3049 // Remove osr nmethod from the list. Return true if found and removed.
3050 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3051   // This is a short non-blocking critical region, so the no safepoint check is ok.
3052   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock
3053                  , Mutex::_no_safepoint_check_flag);
3054   assert(n->is_osr_method(), "wrong kind of nmethod");
3055   nmethod* last = NULL;
3056   nmethod* cur  = osr_nmethods_head();
3057   int max_level = CompLevel_none;  // Find the max comp level excluding n
3058   Method* m = n->method();
3059   // Search for match
3060   bool found = false;
3061   while(cur != NULL && cur != n) {
3062     if (TieredCompilation && m == cur->method()) {
3063       // Find max level before n
3064       max_level = MAX2(max_level, cur->comp_level());
3065     }
3066     last = cur;
3067     cur = cur->osr_link();
3068   }
3069   nmethod* next = NULL;
3070   if (cur == n) {
3071     found = true;
3072     next = cur->osr_link();
3073     if (last == NULL) {
3074       // Remove first element
3075       set_osr_nmethods_head(next);
3076     } else {
3077       last->set_osr_link(next);
3078     }
3079   }
3080   n->set_osr_link(NULL);
3081   if (TieredCompilation) {
3082     cur = next;
3083     while (cur != NULL) {
3084       // Find max level after n
3085       if (m == cur->method()) {
3086         max_level = MAX2(max_level, cur->comp_level());
3087       }
3088       cur = cur->osr_link();
3089     }
3090     m->set_highest_osr_comp_level(max_level);
3091   }
3092   return found;
3093 }
3094 
3095 int InstanceKlass::mark_osr_nmethods(const Method* m) {
3096   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock,
3097                  Mutex::_no_safepoint_check_flag);
3098   nmethod* osr = osr_nmethods_head();
3099   int found = 0;
3100   while (osr != NULL) {
3101     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3102     if (osr->method() == m) {
3103       osr->mark_for_deoptimization();
3104       found++;
3105     }
3106     osr = osr->osr_link();
3107   }
3108   return found;
3109 }
3110 
3111 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3112   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock,
3113                  Mutex::_no_safepoint_check_flag);
3114   nmethod* osr = osr_nmethods_head();
3115   nmethod* best = NULL;
3116   while (osr != NULL) {
3117     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3118     // There can be a time when a c1 osr method exists but we are waiting
3119     // for a c2 version. When c2 completes its osr nmethod we will trash
3120     // the c1 version and only be able to find the c2 version. However
3121     // while we overflow in the c1 code at back branches we don't want to
3122     // try and switch to the same code as we are already running
3123 
3124     if (osr->method() == m &&
3125         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3126       if (match_level) {
3127         if (osr->comp_level() == comp_level) {
3128           // Found a match - return it.
3129           return osr;
3130         }
3131       } else {
3132         if (best == NULL || (osr->comp_level() > best->comp_level())) {
3133           if (osr->comp_level() == CompLevel_highest_tier) {
3134             // Found the best possible - return it.
3135             return osr;
3136           }
3137           best = osr;
3138         }
3139       }
3140     }
3141     osr = osr->osr_link();
3142   }
3143 
3144   assert(match_level == false || best == NULL, "shouldn't pick up anything if match_level is set");
3145   if (best != NULL && best->comp_level() >= comp_level) {
3146     return best;
3147   }
3148   return NULL;
3149 }
3150 
3151 // -----------------------------------------------------------------------------------------------------
3152 // Printing
3153 
3154 #ifndef PRODUCT
3155 
3156 #define BULLET  " - "
3157 
3158 static const char* state_names[] = {
3159   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3160 };
3161 
3162 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3163   for (int i = 0; i < len; i++) {
3164     intptr_t e = start[i];
3165     st->print("%d : " INTPTR_FORMAT, i, e);
3166     if (MetaspaceObj::is_valid((Metadata*)e)) {
3167       st->print(" ");
3168       ((Metadata*)e)->print_value_on(st);
3169     }
3170     st->cr();
3171   }
3172 }
3173 
3174 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3175   return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3176 }
3177 
3178 void InstanceKlass::print_on(outputStream* st) const {
3179   assert(is_klass(), "must be klass");
3180   Klass::print_on(st);
3181 
3182   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
3183   st->print(BULLET"klass size:        %d", size());                               st->cr();
3184   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
3185   st->print(BULLET"state:             "); st->print_cr("%s", state_names[_init_state]);
3186   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
3187   st->print(BULLET"super:             "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3188   st->print(BULLET"sub:               ");
3189   Klass* sub = subklass();
3190   int n;
3191   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
3192     if (n < MaxSubklassPrintSize) {
3193       sub->print_value_on(st);
3194       st->print("   ");
3195     }
3196   }
3197   if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3198   st->cr();
3199 
3200   if (is_interface()) {
3201     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
3202     if (nof_implementors() == 1) {
3203       st->print_cr(BULLET"implementor:    ");
3204       st->print("   ");
3205       implementor()->print_value_on(st);
3206       st->cr();
3207     }
3208   }
3209 
3210   st->print(BULLET"arrays:            "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3211   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
3212   if (Verbose || WizardMode) {
3213     Array<Method*>* method_array = methods();
3214     for (int i = 0; i < method_array->length(); i++) {
3215       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3216     }
3217   }
3218   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
3219   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
3220   if (Verbose && default_methods() != NULL) {
3221     Array<Method*>* method_array = default_methods();
3222     for (int i = 0; i < method_array->length(); i++) {
3223       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3224     }
3225   }
3226   if (default_vtable_indices() != NULL) {
3227     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
3228   }
3229   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
3230   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3231   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
3232   if (class_loader_data() != NULL) {
3233     st->print(BULLET"class loader data:  ");
3234     class_loader_data()->print_value_on(st);
3235     st->cr();
3236   }
3237   st->print(BULLET"unsafe anonymous host class:        "); Metadata::print_value_on_maybe_null(st, unsafe_anonymous_host()); st->cr();
3238   if (source_file_name() != NULL) {
3239     st->print(BULLET"source file:       ");
3240     source_file_name()->print_value_on(st);
3241     st->cr();
3242   }
3243   if (source_debug_extension() != NULL) {
3244     st->print(BULLET"source debug extension:       ");
3245     st->print("%s", source_debug_extension());
3246     st->cr();
3247   }
3248   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
3249   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
3250   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
3251   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
3252   {
3253     bool have_pv = false;
3254     // previous versions are linked together through the InstanceKlass
3255     for (InstanceKlass* pv_node = previous_versions();
3256          pv_node != NULL;
3257          pv_node = pv_node->previous_versions()) {
3258       if (!have_pv)
3259         st->print(BULLET"previous version:  ");
3260       have_pv = true;
3261       pv_node->constants()->print_value_on(st);
3262     }
3263     if (have_pv) st->cr();
3264   }
3265 
3266   if (generic_signature() != NULL) {
3267     st->print(BULLET"generic signature: ");
3268     generic_signature()->print_value_on(st);
3269     st->cr();
3270   }
3271   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
3272   st->print(BULLET"nest members:     "); nest_members()->print_value_on(st);     st->cr();
3273   if (java_mirror() != NULL) {
3274     st->print(BULLET"java mirror:       ");
3275     java_mirror()->print_value_on(st);
3276     st->cr();
3277   } else {
3278     st->print_cr(BULLET"java mirror:       NULL");
3279   }
3280   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3281   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
3282   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3283   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
3284   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3285   FieldPrinter print_static_field(st);
3286   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3287   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3288   FieldPrinter print_nonstatic_field(st);
3289   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3290   ik->do_nonstatic_fields(&print_nonstatic_field);
3291 
3292   st->print(BULLET"non-static oop maps: ");
3293   OopMapBlock* map     = start_of_nonstatic_oop_maps();
3294   OopMapBlock* end_map = map + nonstatic_oop_map_count();
3295   while (map < end_map) {
3296     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3297     map++;
3298   }
3299   st->cr();
3300 }
3301 
3302 #endif //PRODUCT
3303 
3304 void InstanceKlass::print_value_on(outputStream* st) const {
3305   assert(is_klass(), "must be klass");
3306   if (Verbose || WizardMode)  access_flags().print_on(st);
3307   name()->print_value_on(st);
3308 }
3309 
3310 #ifndef PRODUCT
3311 
3312 void FieldPrinter::do_field(fieldDescriptor* fd) {
3313   _st->print(BULLET);
3314    if (_obj == NULL) {
3315      fd->print_on(_st);
3316      _st->cr();
3317    } else {
3318      fd->print_on_for(_st, _obj);
3319      _st->cr();
3320    }
3321 }
3322 
3323 
3324 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3325   Klass::oop_print_on(obj, st);
3326 
3327   if (this == SystemDictionary::String_klass()) {
3328     typeArrayOop value  = java_lang_String::value(obj);
3329     juint        length = java_lang_String::length(obj);
3330     if (value != NULL &&
3331         value->is_typeArray() &&
3332         length <= (juint) value->length()) {
3333       st->print(BULLET"string: ");
3334       java_lang_String::print(obj, st);
3335       st->cr();
3336       if (!WizardMode)  return;  // that is enough
3337     }
3338   }
3339 
3340   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3341   FieldPrinter print_field(st, obj);
3342   do_nonstatic_fields(&print_field);
3343 
3344   if (this == SystemDictionary::Class_klass()) {
3345     st->print(BULLET"signature: ");
3346     java_lang_Class::print_signature(obj, st);
3347     st->cr();
3348     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3349     st->print(BULLET"fake entry for mirror: ");
3350     Metadata::print_value_on_maybe_null(st, mirrored_klass);
3351     st->cr();
3352     Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3353     st->print(BULLET"fake entry for array: ");
3354     Metadata::print_value_on_maybe_null(st, array_klass);
3355     st->cr();
3356     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3357     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3358     Klass* real_klass = java_lang_Class::as_Klass(obj);
3359     if (real_klass != NULL && real_klass->is_instance_klass()) {
3360       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3361     }
3362   } else if (this == SystemDictionary::MethodType_klass()) {
3363     st->print(BULLET"signature: ");
3364     java_lang_invoke_MethodType::print_signature(obj, st);
3365     st->cr();
3366   }
3367 }
3368 
3369 bool InstanceKlass::verify_itable_index(int i) {
3370   int method_count = klassItable::method_count_for_interface(this);
3371   assert(i >= 0 && i < method_count, "index out of bounds");
3372   return true;
3373 }
3374 
3375 #endif //PRODUCT
3376 
3377 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3378   st->print("a ");
3379   name()->print_value_on(st);
3380   obj->print_address_on(st);
3381   if (this == SystemDictionary::String_klass()
3382       && java_lang_String::value(obj) != NULL) {
3383     ResourceMark rm;
3384     int len = java_lang_String::length(obj);
3385     int plen = (len < 24 ? len : 12);
3386     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3387     st->print(" = \"%s\"", str);
3388     if (len > plen)
3389       st->print("...[%d]", len);
3390   } else if (this == SystemDictionary::Class_klass()) {
3391     Klass* k = java_lang_Class::as_Klass(obj);
3392     st->print(" = ");
3393     if (k != NULL) {
3394       k->print_value_on(st);
3395     } else {
3396       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3397       st->print("%s", tname ? tname : "type?");
3398     }
3399   } else if (this == SystemDictionary::MethodType_klass()) {
3400     st->print(" = ");
3401     java_lang_invoke_MethodType::print_signature(obj, st);
3402   } else if (java_lang_boxing_object::is_instance(obj)) {
3403     st->print(" = ");
3404     java_lang_boxing_object::print(obj, st);
3405   } else if (this == SystemDictionary::LambdaForm_klass()) {
3406     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3407     if (vmentry != NULL) {
3408       st->print(" => ");
3409       vmentry->print_value_on(st);
3410     }
3411   } else if (this == SystemDictionary::MemberName_klass()) {
3412     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3413     if (vmtarget != NULL) {
3414       st->print(" = ");
3415       vmtarget->print_value_on(st);
3416     } else {
3417       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3418       st->print(".");
3419       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3420     }
3421   }
3422 }
3423 
3424 const char* InstanceKlass::internal_name() const {
3425   return external_name();
3426 }
3427 
3428 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3429                                              const char* module_name,
3430                                              const ClassFileStream* cfs) const {
3431   if (!log_is_enabled(Info, class, load)) {
3432     return;
3433   }
3434 
3435   ResourceMark rm;
3436   LogMessage(class, load) msg;
3437   stringStream info_stream;
3438 
3439   // Name and class hierarchy info
3440   info_stream.print("%s", external_name());
3441 
3442   // Source
3443   if (cfs != NULL) {
3444     if (cfs->source() != NULL) {
3445       if (module_name != NULL) {
3446         // When the boot loader created the stream, it didn't know the module name
3447         // yet. Let's format it now.
3448         if (cfs->from_boot_loader_modules_image()) {
3449           info_stream.print(" source: jrt:/%s", module_name);
3450         } else {
3451           info_stream.print(" source: %s", cfs->source());
3452         }
3453       } else {
3454         info_stream.print(" source: %s", cfs->source());
3455       }
3456     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3457       Thread* THREAD = Thread::current();
3458       Klass* caller =
3459             THREAD->is_Java_thread()
3460                 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3461                 : NULL;
3462       // caller can be NULL, for example, during a JVMTI VM_Init hook
3463       if (caller != NULL) {
3464         info_stream.print(" source: instance of %s", caller->external_name());
3465       } else {
3466         // source is unknown
3467       }
3468     } else {
3469       oop class_loader = loader_data->class_loader();
3470       info_stream.print(" source: %s", class_loader->klass()->external_name());
3471     }
3472   } else {
3473     assert(this->is_shared(), "must be");
3474     if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3475       info_stream.print(" source: shared objects file (top)");
3476     } else {
3477       info_stream.print(" source: shared objects file");
3478     }
3479   }
3480 
3481   msg.info("%s", info_stream.as_string());
3482 
3483   if (log_is_enabled(Debug, class, load)) {
3484     stringStream debug_stream;
3485 
3486     // Class hierarchy info
3487     debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3488                        p2i(this),  p2i(superklass()));
3489 
3490     // Interfaces
3491     if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3492       debug_stream.print(" interfaces:");
3493       int length = local_interfaces()->length();
3494       for (int i = 0; i < length; i++) {
3495         debug_stream.print(" " INTPTR_FORMAT,
3496                            p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3497       }
3498     }
3499 
3500     // Class loader
3501     debug_stream.print(" loader: [");
3502     loader_data->print_value_on(&debug_stream);
3503     debug_stream.print("]");
3504 
3505     // Classfile checksum
3506     if (cfs) {
3507       debug_stream.print(" bytes: %d checksum: %08x",
3508                          cfs->length(),
3509                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
3510                          cfs->length()));
3511     }
3512 
3513     msg.debug("%s", debug_stream.as_string());
3514   }
3515 }
3516 
3517 #if INCLUDE_SERVICES
3518 // Size Statistics
3519 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3520   Klass::collect_statistics(sz);
3521 
3522   sz->_inst_size  = wordSize * size_helper();
3523   sz->_vtab_bytes = wordSize * vtable_length();
3524   sz->_itab_bytes = wordSize * itable_length();
3525   sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3526 
3527   int n = 0;
3528   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
3529   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
3530   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
3531   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3532   n += (sz->_fields_bytes                = sz->count_array(fields()));
3533   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
3534   n += (sz->_nest_members_bytes          = sz->count_array(nest_members()));
3535   sz->_ro_bytes += n;
3536 
3537   const ConstantPool* cp = constants();
3538   if (cp) {
3539     cp->collect_statistics(sz);
3540   }
3541 
3542   const Annotations* anno = annotations();
3543   if (anno) {
3544     anno->collect_statistics(sz);
3545   }
3546 
3547   const Array<Method*>* methods_array = methods();
3548   if (methods()) {
3549     for (int i = 0; i < methods_array->length(); i++) {
3550       Method* method = methods_array->at(i);
3551       if (method) {
3552         sz->_method_count ++;
3553         method->collect_statistics(sz);
3554       }
3555     }
3556   }
3557 }
3558 #endif // INCLUDE_SERVICES
3559 
3560 // Verification
3561 
3562 class VerifyFieldClosure: public BasicOopIterateClosure {
3563  protected:
3564   template <class T> void do_oop_work(T* p) {
3565     oop obj = RawAccess<>::oop_load(p);
3566     if (!oopDesc::is_oop_or_null(obj)) {
3567       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3568       Universe::print_on(tty);
3569       guarantee(false, "boom");
3570     }
3571   }
3572  public:
3573   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3574   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3575 };
3576 
3577 void InstanceKlass::verify_on(outputStream* st) {
3578 #ifndef PRODUCT
3579   // Avoid redundant verifies, this really should be in product.
3580   if (_verify_count == Universe::verify_count()) return;
3581   _verify_count = Universe::verify_count();
3582 #endif
3583 
3584   // Verify Klass
3585   Klass::verify_on(st);
3586 
3587   // Verify that klass is present in ClassLoaderData
3588   guarantee(class_loader_data()->contains_klass(this),
3589             "this class isn't found in class loader data");
3590 
3591   // Verify vtables
3592   if (is_linked()) {
3593     // $$$ This used to be done only for m/s collections.  Doing it
3594     // always seemed a valid generalization.  (DLD -- 6/00)
3595     vtable().verify(st);
3596   }
3597 
3598   // Verify first subklass
3599   if (subklass() != NULL) {
3600     guarantee(subklass()->is_klass(), "should be klass");
3601   }
3602 
3603   // Verify siblings
3604   Klass* super = this->super();
3605   Klass* sib = next_sibling();
3606   if (sib != NULL) {
3607     if (sib == this) {
3608       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3609     }
3610 
3611     guarantee(sib->is_klass(), "should be klass");
3612     guarantee(sib->super() == super, "siblings should have same superklass");
3613   }
3614 
3615   // Verify local interfaces
3616   if (local_interfaces()) {
3617     Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
3618     for (int j = 0; j < local_interfaces->length(); j++) {
3619       InstanceKlass* e = local_interfaces->at(j);
3620       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3621     }
3622   }
3623 
3624   // Verify transitive interfaces
3625   if (transitive_interfaces() != NULL) {
3626     Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
3627     for (int j = 0; j < transitive_interfaces->length(); j++) {
3628       InstanceKlass* e = transitive_interfaces->at(j);
3629       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3630     }
3631   }
3632 
3633   // Verify methods
3634   if (methods() != NULL) {
3635     Array<Method*>* methods = this->methods();
3636     for (int j = 0; j < methods->length(); j++) {
3637       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3638     }
3639     for (int j = 0; j < methods->length() - 1; j++) {
3640       Method* m1 = methods->at(j);
3641       Method* m2 = methods->at(j + 1);
3642       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3643     }
3644   }
3645 
3646   // Verify method ordering
3647   if (method_ordering() != NULL) {
3648     Array<int>* method_ordering = this->method_ordering();
3649     int length = method_ordering->length();
3650     if (JvmtiExport::can_maintain_original_method_order() ||
3651         ((UseSharedSpaces || Arguments::is_dumping_archive()) && length != 0)) {
3652       guarantee(length == methods()->length(), "invalid method ordering length");
3653       jlong sum = 0;
3654       for (int j = 0; j < length; j++) {
3655         int original_index = method_ordering->at(j);
3656         guarantee(original_index >= 0, "invalid method ordering index");
3657         guarantee(original_index < length, "invalid method ordering index");
3658         sum += original_index;
3659       }
3660       // Verify sum of indices 0,1,...,length-1
3661       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3662     } else {
3663       guarantee(length == 0, "invalid method ordering length");
3664     }
3665   }
3666 
3667   // Verify default methods
3668   if (default_methods() != NULL) {
3669     Array<Method*>* methods = this->default_methods();
3670     for (int j = 0; j < methods->length(); j++) {
3671       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3672     }
3673     for (int j = 0; j < methods->length() - 1; j++) {
3674       Method* m1 = methods->at(j);
3675       Method* m2 = methods->at(j + 1);
3676       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3677     }
3678   }
3679 
3680   // Verify JNI static field identifiers
3681   if (jni_ids() != NULL) {
3682     jni_ids()->verify(this);
3683   }
3684 
3685   // Verify other fields
3686   if (array_klasses() != NULL) {
3687     guarantee(array_klasses()->is_klass(), "should be klass");
3688   }
3689   if (constants() != NULL) {
3690     guarantee(constants()->is_constantPool(), "should be constant pool");
3691   }
3692   const Klass* anonymous_host = unsafe_anonymous_host();
3693   if (anonymous_host != NULL) {
3694     guarantee(anonymous_host->is_klass(), "should be klass");
3695   }
3696 }
3697 
3698 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3699   Klass::oop_verify_on(obj, st);
3700   VerifyFieldClosure blk;
3701   obj->oop_iterate(&blk);
3702 }
3703 
3704 
3705 // JNIid class for jfieldIDs only
3706 // Note to reviewers:
3707 // These JNI functions are just moved over to column 1 and not changed
3708 // in the compressed oops workspace.
3709 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3710   _holder = holder;
3711   _offset = offset;
3712   _next = next;
3713   debug_only(_is_static_field_id = false;)
3714 }
3715 
3716 
3717 JNIid* JNIid::find(int offset) {
3718   JNIid* current = this;
3719   while (current != NULL) {
3720     if (current->offset() == offset) return current;
3721     current = current->next();
3722   }
3723   return NULL;
3724 }
3725 
3726 void JNIid::deallocate(JNIid* current) {
3727   while (current != NULL) {
3728     JNIid* next = current->next();
3729     delete current;
3730     current = next;
3731   }
3732 }
3733 
3734 
3735 void JNIid::verify(Klass* holder) {
3736   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3737   int end_field_offset;
3738   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3739 
3740   JNIid* current = this;
3741   while (current != NULL) {
3742     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3743 #ifdef ASSERT
3744     int o = current->offset();
3745     if (current->is_static_field_id()) {
3746       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3747     }
3748 #endif
3749     current = current->next();
3750   }
3751 }
3752 
3753 void InstanceKlass::set_init_state(ClassState state) {
3754 #ifdef ASSERT
3755   bool good_state = is_shared() ? (_init_state <= state)
3756                                                : (_init_state < state);
3757   assert(good_state || state == allocated, "illegal state transition");
3758 #endif
3759   assert(_init_thread == NULL, "should be cleared before state change");
3760   _init_state = (u1)state;
3761 }
3762 
3763 #if INCLUDE_JVMTI
3764 
3765 // RedefineClasses() support for previous versions
3766 
3767 // Globally, there is at least one previous version of a class to walk
3768 // during class unloading, which is saved because old methods in the class
3769 // are still running.   Otherwise the previous version list is cleaned up.
3770 bool InstanceKlass::_has_previous_versions = false;
3771 
3772 // Returns true if there are previous versions of a class for class
3773 // unloading only. Also resets the flag to false. purge_previous_version
3774 // will set the flag to true if there are any left, i.e., if there's any
3775 // work to do for next time. This is to avoid the expensive code cache
3776 // walk in CLDG::clean_deallocate_lists().
3777 bool InstanceKlass::has_previous_versions_and_reset() {
3778   bool ret = _has_previous_versions;
3779   log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3780      ret ? "true" : "false");
3781   _has_previous_versions = false;
3782   return ret;
3783 }
3784 
3785 // Purge previous versions before adding new previous versions of the class and
3786 // during class unloading.
3787 void InstanceKlass::purge_previous_version_list() {
3788   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3789   assert(has_been_redefined(), "Should only be called for main class");
3790 
3791   // Quick exit.
3792   if (previous_versions() == NULL) {
3793     return;
3794   }
3795 
3796   // This klass has previous versions so see what we can cleanup
3797   // while it is safe to do so.
3798 
3799   int deleted_count = 0;    // leave debugging breadcrumbs
3800   int live_count = 0;
3801   ClassLoaderData* loader_data = class_loader_data();
3802   assert(loader_data != NULL, "should never be null");
3803 
3804   ResourceMark rm;
3805   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3806 
3807   // previous versions are linked together through the InstanceKlass
3808   InstanceKlass* pv_node = previous_versions();
3809   InstanceKlass* last = this;
3810   int version = 0;
3811 
3812   // check the previous versions list
3813   for (; pv_node != NULL; ) {
3814 
3815     ConstantPool* pvcp = pv_node->constants();
3816     assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3817 
3818     if (!pvcp->on_stack()) {
3819       // If the constant pool isn't on stack, none of the methods
3820       // are executing.  Unlink this previous_version.
3821       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3822       // so will be deallocated during the next phase of class unloading.
3823       log_trace(redefine, class, iklass, purge)
3824         ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3825       // For debugging purposes.
3826       pv_node->set_is_scratch_class();
3827       // Unlink from previous version list.
3828       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3829       InstanceKlass* next = pv_node->previous_versions();
3830       pv_node->link_previous_versions(NULL);   // point next to NULL
3831       last->link_previous_versions(next);
3832       // Add to the deallocate list after unlinking
3833       loader_data->add_to_deallocate_list(pv_node);
3834       pv_node = next;
3835       deleted_count++;
3836       version++;
3837       continue;
3838     } else {
3839       log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3840       assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3841       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3842       live_count++;
3843       // found a previous version for next time we do class unloading
3844       _has_previous_versions = true;
3845     }
3846 
3847     // At least one method is live in this previous version.
3848     // Reset dead EMCP methods not to get breakpoints.
3849     // All methods are deallocated when all of the methods for this class are no
3850     // longer running.
3851     Array<Method*>* method_refs = pv_node->methods();
3852     if (method_refs != NULL) {
3853       log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3854       for (int j = 0; j < method_refs->length(); j++) {
3855         Method* method = method_refs->at(j);
3856 
3857         if (!method->on_stack()) {
3858           // no breakpoints for non-running methods
3859           if (method->is_running_emcp()) {
3860             method->set_running_emcp(false);
3861           }
3862         } else {
3863           assert (method->is_obsolete() || method->is_running_emcp(),
3864                   "emcp method cannot run after emcp bit is cleared");
3865           log_trace(redefine, class, iklass, purge)
3866             ("purge: %s(%s): prev method @%d in version @%d is alive",
3867              method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3868         }
3869       }
3870     }
3871     // next previous version
3872     last = pv_node;
3873     pv_node = pv_node->previous_versions();
3874     version++;
3875   }
3876   log_trace(redefine, class, iklass, purge)
3877     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3878 }
3879 
3880 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3881                                                 int emcp_method_count) {
3882   int obsolete_method_count = old_methods->length() - emcp_method_count;
3883 
3884   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3885       _previous_versions != NULL) {
3886     // We have a mix of obsolete and EMCP methods so we have to
3887     // clear out any matching EMCP method entries the hard way.
3888     int local_count = 0;
3889     for (int i = 0; i < old_methods->length(); i++) {
3890       Method* old_method = old_methods->at(i);
3891       if (old_method->is_obsolete()) {
3892         // only obsolete methods are interesting
3893         Symbol* m_name = old_method->name();
3894         Symbol* m_signature = old_method->signature();
3895 
3896         // previous versions are linked together through the InstanceKlass
3897         int j = 0;
3898         for (InstanceKlass* prev_version = _previous_versions;
3899              prev_version != NULL;
3900              prev_version = prev_version->previous_versions(), j++) {
3901 
3902           Array<Method*>* method_refs = prev_version->methods();
3903           for (int k = 0; k < method_refs->length(); k++) {
3904             Method* method = method_refs->at(k);
3905 
3906             if (!method->is_obsolete() &&
3907                 method->name() == m_name &&
3908                 method->signature() == m_signature) {
3909               // The current RedefineClasses() call has made all EMCP
3910               // versions of this method obsolete so mark it as obsolete
3911               log_trace(redefine, class, iklass, add)
3912                 ("%s(%s): flush obsolete method @%d in version @%d",
3913                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
3914 
3915               method->set_is_obsolete();
3916               break;
3917             }
3918           }
3919 
3920           // The previous loop may not find a matching EMCP method, but
3921           // that doesn't mean that we can optimize and not go any
3922           // further back in the PreviousVersion generations. The EMCP
3923           // method for this generation could have already been made obsolete,
3924           // but there still may be an older EMCP method that has not
3925           // been made obsolete.
3926         }
3927 
3928         if (++local_count >= obsolete_method_count) {
3929           // no more obsolete methods so bail out now
3930           break;
3931         }
3932       }
3933     }
3934   }
3935 }
3936 
3937 // Save the scratch_class as the previous version if any of the methods are running.
3938 // The previous_versions are used to set breakpoints in EMCP methods and they are
3939 // also used to clean MethodData links to redefined methods that are no longer running.
3940 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3941                                          int emcp_method_count) {
3942   assert(Thread::current()->is_VM_thread(),
3943          "only VMThread can add previous versions");
3944 
3945   ResourceMark rm;
3946   log_trace(redefine, class, iklass, add)
3947     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3948 
3949   // Clean out old previous versions for this class
3950   purge_previous_version_list();
3951 
3952   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
3953   // a previous redefinition may be made obsolete by this redefinition.
3954   Array<Method*>* old_methods = scratch_class->methods();
3955   mark_newly_obsolete_methods(old_methods, emcp_method_count);
3956 
3957   // If the constant pool for this previous version of the class
3958   // is not marked as being on the stack, then none of the methods
3959   // in this previous version of the class are on the stack so
3960   // we don't need to add this as a previous version.
3961   ConstantPool* cp_ref = scratch_class->constants();
3962   if (!cp_ref->on_stack()) {
3963     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3964     // For debugging purposes.
3965     scratch_class->set_is_scratch_class();
3966     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3967     return;
3968   }
3969 
3970   if (emcp_method_count != 0) {
3971     // At least one method is still running, check for EMCP methods
3972     for (int i = 0; i < old_methods->length(); i++) {
3973       Method* old_method = old_methods->at(i);
3974       if (!old_method->is_obsolete() && old_method->on_stack()) {
3975         // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3976         // we can add breakpoints for it.
3977 
3978         // We set the method->on_stack bit during safepoints for class redefinition
3979         // and use this bit to set the is_running_emcp bit.
3980         // After the safepoint, the on_stack bit is cleared and the running emcp
3981         // method may exit.   If so, we would set a breakpoint in a method that
3982         // is never reached, but this won't be noticeable to the programmer.
3983         old_method->set_running_emcp(true);
3984         log_trace(redefine, class, iklass, add)
3985           ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3986       } else if (!old_method->is_obsolete()) {
3987         log_trace(redefine, class, iklass, add)
3988           ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3989       }
3990     }
3991   }
3992 
3993   // Add previous version if any methods are still running.
3994   // Set has_previous_version flag for processing during class unloading.
3995   _has_previous_versions = true;
3996   log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3997   assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3998   scratch_class->link_previous_versions(previous_versions());
3999   link_previous_versions(scratch_class);
4000 } // end add_previous_version()
4001 
4002 #endif // INCLUDE_JVMTI
4003 
4004 Method* InstanceKlass::method_with_idnum(int idnum) {
4005   Method* m = NULL;
4006   if (idnum < methods()->length()) {
4007     m = methods()->at(idnum);
4008   }
4009   if (m == NULL || m->method_idnum() != idnum) {
4010     for (int index = 0; index < methods()->length(); ++index) {
4011       m = methods()->at(index);
4012       if (m->method_idnum() == idnum) {
4013         return m;
4014       }
4015     }
4016     // None found, return null for the caller to handle.
4017     return NULL;
4018   }
4019   return m;
4020 }
4021 
4022 
4023 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4024   if (idnum >= methods()->length()) {
4025     return NULL;
4026   }
4027   Method* m = methods()->at(idnum);
4028   if (m != NULL && m->orig_method_idnum() == idnum) {
4029     return m;
4030   }
4031   // Obsolete method idnum does not match the original idnum
4032   for (int index = 0; index < methods()->length(); ++index) {
4033     m = methods()->at(index);
4034     if (m->orig_method_idnum() == idnum) {
4035       return m;
4036     }
4037   }
4038   // None found, return null for the caller to handle.
4039   return NULL;
4040 }
4041 
4042 
4043 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4044   InstanceKlass* holder = get_klass_version(version);
4045   if (holder == NULL) {
4046     return NULL; // The version of klass is gone, no method is found
4047   }
4048   Method* method = holder->method_with_orig_idnum(idnum);
4049   return method;
4050 }
4051 
4052 #if INCLUDE_JVMTI
4053 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4054   return _cached_class_file;
4055 }
4056 
4057 jint InstanceKlass::get_cached_class_file_len() {
4058   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4059 }
4060 
4061 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4062   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4063 }
4064 #endif
--- EOF ---