1 /*
   2  * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "aot/aotLoader.hpp"
  28 #include "classfile/classFileParser.hpp"
  29 #include "classfile/classFileStream.hpp"
  30 #include "classfile/classLoader.hpp"
  31 #include "classfile/classLoaderData.inline.hpp"
  32 #include "classfile/javaClasses.hpp"
  33 #include "classfile/moduleEntry.hpp"
  34 #include "classfile/symbolTable.hpp"
  35 #include "classfile/systemDictionary.hpp"
  36 #include "classfile/systemDictionaryShared.hpp"
  37 #include "classfile/verifier.hpp"
  38 #include "classfile/vmSymbols.hpp"
  39 #include "code/dependencyContext.hpp"
  40 #include "compiler/compileBroker.hpp"
  41 #include "gc/shared/collectedHeap.inline.hpp"
  42 #include "interpreter/oopMapCache.hpp"
  43 #include "interpreter/rewriter.hpp"
  44 #include "jvmtifiles/jvmti.h"
  45 #include "logging/log.hpp"
  46 #include "logging/logMessage.hpp"
  47 #include "logging/logStream.hpp"
  48 #include "memory/allocation.inline.hpp"
  49 #include "memory/iterator.inline.hpp"
  50 #include "memory/metadataFactory.hpp"
  51 #include "memory/metaspaceClosure.hpp"
  52 #include "memory/metaspaceShared.hpp"
  53 #include "memory/oopFactory.hpp"
  54 #include "memory/resourceArea.hpp"
  55 #include "memory/universe.hpp"
  56 #include "oops/fieldStreams.inline.hpp"
  57 #include "oops/constantPool.hpp"
  58 #include "oops/instanceClassLoaderKlass.hpp"
  59 #include "oops/instanceKlass.inline.hpp"
  60 #include "oops/instanceMirrorKlass.hpp"
  61 #include "oops/instanceOop.hpp"
  62 #include "oops/klass.inline.hpp"
  63 #include "oops/method.hpp"
  64 #include "oops/oop.inline.hpp"
  65 #include "oops/recordComponent.hpp"
  66 #include "oops/symbol.hpp"
  67 #include "prims/jvmtiExport.hpp"
  68 #include "prims/jvmtiRedefineClasses.hpp"
  69 #include "prims/jvmtiThreadState.hpp"
  70 #include "prims/methodComparator.hpp"
  71 #include "runtime/atomic.hpp"
  72 #include "runtime/biasedLocking.hpp"
  73 #include "runtime/fieldDescriptor.inline.hpp"
  74 #include "runtime/handles.inline.hpp"
  75 #include "runtime/javaCalls.hpp"
  76 #include "runtime/mutexLocker.hpp"
  77 #include "runtime/orderAccess.hpp"
  78 #include "runtime/thread.inline.hpp"
  79 #include "services/classLoadingService.hpp"
  80 #include "services/threadService.hpp"
  81 #include "utilities/dtrace.hpp"
  82 #include "utilities/events.hpp"
  83 #include "utilities/macros.hpp"
  84 #include "utilities/stringUtils.hpp"
  85 #ifdef COMPILER1
  86 #include "c1/c1_Compiler.hpp"
  87 #endif
  88 #if INCLUDE_JFR
  89 #include "jfr/jfrEvents.hpp"
  90 #endif
  91 
  92 
  93 #ifdef DTRACE_ENABLED
  94 
  95 
  96 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
  97 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
  98 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
  99 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
 100 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
 101 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
 102 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
 103 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
 104 #define DTRACE_CLASSINIT_PROBE(type, thread_type)                \
 105   {                                                              \
 106     char* data = NULL;                                           \
 107     int len = 0;                                                 \
 108     Symbol* clss_name = name();                                  \
 109     if (clss_name != NULL) {                                     \
 110       data = (char*)clss_name->bytes();                          \
 111       len = clss_name->utf8_length();                            \
 112     }                                                            \
 113     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 114       data, len, (void*)class_loader(), thread_type);            \
 115   }
 116 
 117 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)     \
 118   {                                                              \
 119     char* data = NULL;                                           \
 120     int len = 0;                                                 \
 121     Symbol* clss_name = name();                                  \
 122     if (clss_name != NULL) {                                     \
 123       data = (char*)clss_name->bytes();                          \
 124       len = clss_name->utf8_length();                            \
 125     }                                                            \
 126     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 127       data, len, (void*)class_loader(), thread_type, wait);      \
 128   }
 129 
 130 #else //  ndef DTRACE_ENABLED
 131 
 132 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
 133 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
 134 
 135 #endif //  ndef DTRACE_ENABLED
 136 
 137 static inline bool is_class_loader(const Symbol* class_name,
 138                                    const ClassFileParser& parser) {
 139   assert(class_name != NULL, "invariant");
 140 
 141   if (class_name == vmSymbols::java_lang_ClassLoader()) {
 142     return true;
 143   }
 144 
 145   if (SystemDictionary::ClassLoader_klass_loaded()) {
 146     const Klass* const super_klass = parser.super_klass();
 147     if (super_klass != NULL) {
 148       if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
 149         return true;
 150       }
 151     }
 152   }
 153   return false;
 154 }
 155 
 156 // private: called to verify that k is a static member of this nest.
 157 // We know that k is an instance class in the same package and hence the
 158 // same classloader.
 159 bool InstanceKlass::has_nest_member(InstanceKlass* k, TRAPS) const {
 160   assert(!is_hidden(), "unexpected hidden class");
 161   if (_nest_members == NULL || _nest_members == Universe::the_empty_short_array()) {
 162     if (log_is_enabled(Trace, class, nestmates)) {
 163       ResourceMark rm(THREAD);
 164       log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
 165                                   k->external_name(), this->external_name());
 166     }
 167     return false;
 168   }
 169 
 170   if (log_is_enabled(Trace, class, nestmates)) {
 171     ResourceMark rm(THREAD);
 172     log_trace(class, nestmates)("Checking nest membership of %s in %s",
 173                                 k->external_name(), this->external_name());
 174   }
 175 
 176   // Check for a resolved cp entry , else fall back to a name check.
 177   // We don't want to resolve any class other than the one being checked.
 178   for (int i = 0; i < _nest_members->length(); i++) {
 179     int cp_index = _nest_members->at(i);
 180     if (_constants->tag_at(cp_index).is_klass()) {
 181       Klass* k2 = _constants->klass_at(cp_index, THREAD);
 182       assert(!HAS_PENDING_EXCEPTION || PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass()),
 183              "Exceptions should not be possible here");
 184       if (k2 == k) {
 185         log_trace(class, nestmates)("- class is listed at nest_members[%d] => cp[%d]", i, cp_index);
 186         return true;
 187       }
 188     }
 189     else {
 190       Symbol* name = _constants->klass_name_at(cp_index);
 191       if (name == k->name()) {
 192         log_trace(class, nestmates)("- Found it at nest_members[%d] => cp[%d]", i, cp_index);
 193 
 194         // Names match so check actual klass. This may trigger class loading if
 195         // it doesn't match though that should be impossible as it means one classloader
 196         // has defined two different classes with the same name! A compiler thread won't be
 197         // able to perform that loading but we can't exclude the compiler threads from
 198         // executing this logic. But it should actually be impossible to trigger loading here.
 199         Klass* k2 = _constants->klass_at(cp_index, THREAD);
 200         assert(!HAS_PENDING_EXCEPTION || PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass()),
 201                "Exceptions should not be possible here");
 202         if (k2 == k) {
 203           log_trace(class, nestmates)("- class is listed as a nest member");
 204           return true;
 205         }
 206         else {
 207           // same name but different klass!
 208           log_trace(class, nestmates)(" - klass comparison failed!");
 209           // can't have two names the same, so we're done
 210           return false;
 211         }
 212       }
 213     }
 214   }
 215   log_trace(class, nestmates)("- class is NOT a nest member!");
 216   return false;
 217 }
 218 
 219 // Return nest-host class, resolving, validating and saving it if needed.
 220 // In cases where this is called from a thread that cannot do classloading
 221 // (such as a native JIT thread) then we simply return NULL, which in turn
 222 // causes the access check to return false. Such code will retry the access
 223 // from a more suitable environment later. Otherwise the _nest_host is always
 224 // set once this method returns.
 225 // Any errors from nest-host resolution must be preserved so they can be queried
 226 // from higher-level access checking code, and reported as part of access checking
 227 // exceptions.
 228 // VirtualMachineErrors are propagated with a NULL return.
 229 // Under any conditions where the _nest_host can be set to non-NULL the resulting value
 230 // of it and, if applicable, _nest_host_res_error, are idempotent. But as we can be
 231 // executing this code concurrently we need to ensure ordering is maintained so that
 232 // errors messages can safely be read.
 233 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
 234   InstanceKlass* nest_host_k = _nest_host;
 235   if (nest_host_k != NULL) {
 236     return nest_host_k;
 237   }
 238 
 239   const bool doLog = log_is_enabled(Trace, class, nestmates);
 240 
 241   // need to resolve and save our nest-host class.
 242   if (_nest_host_index != 0) { // we have a real nest_host
 243     // Before trying to resolve check if we're in a suitable context
 244     if (!THREAD->can_call_java() && !_constants->tag_at(_nest_host_index).is_klass()) {
 245       if (doLog) {
 246         ResourceMark rm(THREAD);
 247         log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
 248                                     this->external_name());
 249       }
 250       return NULL; // sentinel to say "try again from a different context"
 251     }
 252 
 253     if (doLog) {
 254       ResourceMark rm(THREAD);
 255       log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
 256                                   this->external_name(),
 257                                   _constants->klass_name_at(_nest_host_index)->as_C_string());
 258     }
 259 
 260     Klass* k = _constants->klass_at(_nest_host_index, THREAD);
 261     if (HAS_PENDING_EXCEPTION) {
 262       if (PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass())) {
 263         return NULL; // propagate VMEs
 264       }
 265       ResourceMark rm(THREAD);
 266       stringStream ss;
 267       char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
 268       ss.print("Nest host resolution of %s with host %s failed: ",
 269                this->external_name(), target_host_class);
 270       java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
 271       _nest_host_res_error = ss.as_string(true /* on C-heap */);
 272       // ensure we see _nest_host_res_error is set if _nest_host is non-NULL
 273       OrderAccess::storestore();
 274       CLEAR_PENDING_EXCEPTION;
 275       if (doLog) {
 276         log_trace(class, nestmates)("%s", _nest_host_res_error);
 277       }
 278     } else {
 279       // A valid nest-host is an instance class in the current package that lists this
 280       // class as a nest member. If any of these conditions are not met the class is
 281       // its own nest-host.
 282       const char* error = NULL;
 283 
 284       // JVMS 5.4.4 indicates package check comes first
 285       if (is_same_class_package(k)) {
 286         // Now check actual membership. We can't be a member if our "host" is
 287         // not an instance class.
 288         if (k->is_instance_klass()) {
 289           nest_host_k = InstanceKlass::cast(k);
 290           bool is_member = nest_host_k->has_nest_member(this, THREAD);
 291           // exception is rare, perhaps impossible
 292           if (!HAS_PENDING_EXCEPTION) {
 293             if (is_member) {
 294               _nest_host = nest_host_k; // save resolved nest-host value
 295               if (doLog) {
 296                 ResourceMark rm(THREAD);
 297                 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
 298                                             this->external_name(), k->external_name());
 299               }
 300               return nest_host_k;
 301             } else {
 302               error = "current type is not listed as a nest member";
 303             }
 304           } else {
 305             if (PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass())) {
 306               return NULL; // propagate VMEs
 307             }
 308             stringStream ss;
 309             ss.print("exception on member check: ");
 310             java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
 311             error = ss.as_string();
 312           }
 313         } else {
 314           error = "host is not an instance class";
 315         }
 316       } else {
 317         error = "types are in different packages";
 318       }
 319 
 320       // something went wrong, so record what and log it
 321       {
 322         ResourceMark rm(THREAD);
 323         stringStream ss;
 324         ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
 325                  this->external_name(),
 326                  this->class_loader_data()->loader_name_and_id(),
 327                  k->external_name(),
 328                  k->class_loader_data()->loader_name_and_id(),
 329                  error);
 330         _nest_host_res_error = ss.as_string(true /* on C-heap */);
 331         // ensure we see _nest_host_res_error is set if _nest_host is non-NULL
 332         OrderAccess::storestore();
 333 
 334         if (doLog) {
 335           log_trace(class, nestmates)("%s", _nest_host_res_error);
 336         }
 337       }
 338     }
 339   } else {
 340     if (doLog) {
 341       ResourceMark rm(THREAD);
 342       log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
 343                                   this->external_name());
 344     }
 345   }
 346 
 347   // Either not in an explicit nest, or else an error occurred, so
 348   // the nest-host is set to `this`. Any thread that sees this assignment
 349   // will also see any setting of _nest_host_res_error, if applicable.
 350   return (_nest_host = this);
 351 }
 352 
 353 // Dynamic nest member support: set this class's nest host to the given class.
 354 // This occurs as part of the class definition, as soon as the instanceKlass
 355 // has been created and doesn't require further resolution. The code:
 356 //    lookup().defineHiddenClass(bytes_for_X, NESTMATE);
 357 // results in:
 358 //    class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
 359 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
 360 // We also know the "host" is a valid nest-host in the same package so we can
 361 // assert some of those facts.
 362 void InstanceKlass::set_nest_host(InstanceKlass* host, TRAPS) {
 363   assert(is_hidden(), "must be a hidden class");
 364   assert(host != NULL, "NULL nest host specified");
 365   assert(_nest_host == NULL, "current class has resolved nest-host");
 366   assert(_nest_host_res_error == NULL, "unexpected nest host resolution error exists: %s",
 367          _nest_host_res_error);
 368   assert((host->_nest_host == NULL && host->_nest_host_index == 0) ||
 369          (host->_nest_host == host), "proposed host is not a valid nest-host");
 370   // Can't assert this as package is not set yet:
 371   // assert(is_same_class_package(host), "proposed host is in wrong package");
 372 
 373   if (log_is_enabled(Trace, class, nestmates)) {
 374     ResourceMark rm(THREAD);
 375     const char* msg = "";
 376     // a hidden class does not expect a statically defined nest-host
 377     if (_nest_host_index > 0) {
 378       msg = "(the NestHost attribute in the current class is ignored)";
 379     } else if (_nest_members != NULL && _nest_members != Universe::the_empty_short_array()) {
 380       msg = "(the NestMembers attribute in the current class is ignored)";
 381     }
 382     log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
 383                                 this->external_name(),
 384                                 host->external_name(),
 385                                 msg);
 386   }
 387   // set dynamic nest host
 388   _nest_host = host;
 389 }
 390 
 391 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
 392 // or we are k's nest_host - all of which is covered by comparing the two
 393 // resolved_nest_hosts.
 394 // Any exceptions (i.e. VMEs) are propagated.
 395 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
 396 
 397   assert(this != k, "this should be handled by higher-level code");
 398 
 399   // Per JVMS 5.4.4 we first resolve and validate the current class, then
 400   // the target class k.
 401 
 402   InstanceKlass* cur_host = nest_host(CHECK_false);
 403   if (cur_host == NULL) {
 404     return false;
 405   }
 406 
 407   Klass* k_nest_host = k->nest_host(CHECK_false);
 408   if (k_nest_host == NULL) {
 409     return false;
 410   }
 411 
 412   bool access = (cur_host == k_nest_host);
 413 
 414   if (log_is_enabled(Trace, class, nestmates)) {
 415     ResourceMark rm(THREAD);
 416     log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
 417                                 this->external_name(),
 418                                 access ? "" : "NOT ",
 419                                 k->external_name());
 420   }
 421 
 422   return access;
 423 }
 424 
 425 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
 426   bool is_hidden_or_anonymous = parser.is_hidden() || parser.is_unsafe_anonymous();
 427   const int size = InstanceKlass::size(parser.vtable_size(),
 428                                        parser.itable_size(),
 429                                        nonstatic_oop_map_size(parser.total_oop_map_count()),
 430                                        parser.is_interface(),
 431                                        is_hidden_or_anonymous,
 432                                        should_store_fingerprint(is_hidden_or_anonymous));
 433 
 434   const Symbol* const class_name = parser.class_name();
 435   assert(class_name != NULL, "invariant");
 436   ClassLoaderData* loader_data = parser.loader_data();
 437   assert(loader_data != NULL, "invariant");
 438 
 439   InstanceKlass* ik;
 440 
 441   // Allocation
 442   if (REF_NONE == parser.reference_type()) {
 443     if (class_name == vmSymbols::java_lang_Class()) {
 444       // mirror
 445       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
 446     }
 447     else if (is_class_loader(class_name, parser)) {
 448       // class loader
 449       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
 450     } else {
 451       // normal
 452       ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
 453     }
 454   } else {
 455     // reference
 456     ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
 457   }
 458 
 459   // Check for pending exception before adding to the loader data and incrementing
 460   // class count.  Can get OOM here.
 461   if (HAS_PENDING_EXCEPTION) {
 462     return NULL;
 463   }
 464 
 465   return ik;
 466 }
 467 
 468 
 469 // copy method ordering from resource area to Metaspace
 470 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
 471   if (m != NULL) {
 472     // allocate a new array and copy contents (memcpy?)
 473     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
 474     for (int i = 0; i < m->length(); i++) {
 475       _method_ordering->at_put(i, m->at(i));
 476     }
 477   } else {
 478     _method_ordering = Universe::the_empty_int_array();
 479   }
 480 }
 481 
 482 // create a new array of vtable_indices for default methods
 483 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
 484   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
 485   assert(default_vtable_indices() == NULL, "only create once");
 486   set_default_vtable_indices(vtable_indices);
 487   return vtable_indices;
 488 }
 489 
 490 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind, KlassID id) :
 491   Klass(id),
 492   _nest_members(NULL),
 493   _nest_host_index(0),
 494   _nest_host(NULL),
 495   _nest_host_res_error(NULL),
 496   _record_components(NULL),
 497   _static_field_size(parser.static_field_size()),
 498   _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
 499   _itable_len(parser.itable_size()),
 500   _init_thread(NULL),
 501   _init_state(allocated),
 502   _reference_type(parser.reference_type())
 503 {
 504   set_vtable_length(parser.vtable_size());
 505   set_kind(kind);
 506   set_access_flags(parser.access_flags());
 507   if (parser.is_hidden()) set_is_hidden();
 508   set_is_unsafe_anonymous(parser.is_unsafe_anonymous());
 509   set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
 510                                                     false));
 511 
 512   assert(NULL == _methods, "underlying memory not zeroed?");
 513   assert(is_instance_klass(), "is layout incorrect?");
 514   assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
 515 
 516   if (Arguments::is_dumping_archive()) {
 517     SystemDictionaryShared::init_dumptime_info(this);
 518   }
 519 
 520   // Set biased locking bit for all instances of this class; it will be
 521   // cleared if revocation occurs too often for this type
 522   if (UseBiasedLocking && BiasedLocking::enabled()) {
 523     set_prototype_header(markWord::biased_locking_prototype());
 524   }
 525 }
 526 
 527 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 528                                        Array<Method*>* methods) {
 529   if (methods != NULL && methods != Universe::the_empty_method_array() &&
 530       !methods->is_shared()) {
 531     for (int i = 0; i < methods->length(); i++) {
 532       Method* method = methods->at(i);
 533       if (method == NULL) continue;  // maybe null if error processing
 534       // Only want to delete methods that are not executing for RedefineClasses.
 535       // The previous version will point to them so they're not totally dangling
 536       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 537       MetadataFactory::free_metadata(loader_data, method);
 538     }
 539     MetadataFactory::free_array<Method*>(loader_data, methods);
 540   }
 541 }
 542 
 543 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 544                                           const Klass* super_klass,
 545                                           Array<InstanceKlass*>* local_interfaces,
 546                                           Array<InstanceKlass*>* transitive_interfaces) {
 547   // Only deallocate transitive interfaces if not empty, same as super class
 548   // or same as local interfaces.  See code in parseClassFile.
 549   Array<InstanceKlass*>* ti = transitive_interfaces;
 550   if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
 551     // check that the interfaces don't come from super class
 552     Array<InstanceKlass*>* sti = (super_klass == NULL) ? NULL :
 553                     InstanceKlass::cast(super_klass)->transitive_interfaces();
 554     if (ti != sti && ti != NULL && !ti->is_shared()) {
 555       MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
 556     }
 557   }
 558 
 559   // local interfaces can be empty
 560   if (local_interfaces != Universe::the_empty_instance_klass_array() &&
 561       local_interfaces != NULL && !local_interfaces->is_shared()) {
 562     MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
 563   }
 564 }
 565 
 566 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
 567                                                  Array<RecordComponent*>* record_components) {
 568   if (record_components != NULL && !record_components->is_shared()) {
 569     for (int i = 0; i < record_components->length(); i++) {
 570       RecordComponent* record_component = record_components->at(i);
 571       MetadataFactory::free_metadata(loader_data, record_component);
 572     }
 573     MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
 574   }
 575 }
 576 
 577 // This function deallocates the metadata and C heap pointers that the
 578 // InstanceKlass points to.
 579 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 580 
 581   // Orphan the mirror first, CMS thinks it's still live.
 582   if (java_mirror() != NULL) {
 583     java_lang_Class::set_klass(java_mirror(), NULL);
 584   }
 585 
 586   // Also remove mirror from handles
 587   loader_data->remove_handle(_java_mirror);
 588 
 589   // Need to take this class off the class loader data list.
 590   loader_data->remove_class(this);
 591 
 592   // The array_klass for this class is created later, after error handling.
 593   // For class redefinition, we keep the original class so this scratch class
 594   // doesn't have an array class.  Either way, assert that there is nothing
 595   // to deallocate.
 596   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
 597 
 598   // Release C heap allocated data that this might point to, which includes
 599   // reference counting symbol names.
 600   release_C_heap_structures();
 601 
 602   deallocate_methods(loader_data, methods());
 603   set_methods(NULL);
 604 
 605   deallocate_record_components(loader_data, record_components());
 606   set_record_components(NULL);
 607 
 608   if (method_ordering() != NULL &&
 609       method_ordering() != Universe::the_empty_int_array() &&
 610       !method_ordering()->is_shared()) {
 611     MetadataFactory::free_array<int>(loader_data, method_ordering());
 612   }
 613   set_method_ordering(NULL);
 614 
 615   // default methods can be empty
 616   if (default_methods() != NULL &&
 617       default_methods() != Universe::the_empty_method_array() &&
 618       !default_methods()->is_shared()) {
 619     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 620   }
 621   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 622   set_default_methods(NULL);
 623 
 624   // default methods vtable indices can be empty
 625   if (default_vtable_indices() != NULL &&
 626       !default_vtable_indices()->is_shared()) {
 627     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 628   }
 629   set_default_vtable_indices(NULL);
 630 
 631 
 632   // This array is in Klass, but remove it with the InstanceKlass since
 633   // this place would be the only caller and it can share memory with transitive
 634   // interfaces.
 635   if (secondary_supers() != NULL &&
 636       secondary_supers() != Universe::the_empty_klass_array() &&
 637       // see comments in compute_secondary_supers about the following cast
 638       (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
 639       !secondary_supers()->is_shared()) {
 640     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 641   }
 642   set_secondary_supers(NULL);
 643 
 644   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 645   set_transitive_interfaces(NULL);
 646   set_local_interfaces(NULL);
 647 
 648   if (fields() != NULL && !fields()->is_shared()) {
 649     MetadataFactory::free_array<jushort>(loader_data, fields());
 650   }
 651   set_fields(NULL, 0);
 652 
 653   // If a method from a redefined class is using this constant pool, don't
 654   // delete it, yet.  The new class's previous version will point to this.
 655   if (constants() != NULL) {
 656     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 657     if (!constants()->is_shared()) {
 658       MetadataFactory::free_metadata(loader_data, constants());
 659     }
 660     // Delete any cached resolution errors for the constant pool
 661     SystemDictionary::delete_resolution_error(constants());
 662 
 663     set_constants(NULL);
 664   }
 665 
 666   if (inner_classes() != NULL &&
 667       inner_classes() != Universe::the_empty_short_array() &&
 668       !inner_classes()->is_shared()) {
 669     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 670   }
 671   set_inner_classes(NULL);
 672 
 673   if (nest_members() != NULL &&
 674       nest_members() != Universe::the_empty_short_array() &&
 675       !nest_members()->is_shared()) {
 676     MetadataFactory::free_array<jushort>(loader_data, nest_members());
 677   }
 678   set_nest_members(NULL);
 679 
 680   // We should deallocate the Annotations instance if it's not in shared spaces.
 681   if (annotations() != NULL && !annotations()->is_shared()) {
 682     MetadataFactory::free_metadata(loader_data, annotations());
 683   }
 684   set_annotations(NULL);
 685 
 686   if (Arguments::is_dumping_archive()) {
 687     SystemDictionaryShared::remove_dumptime_info(this);
 688   }
 689 }
 690 
 691 bool InstanceKlass::should_be_initialized() const {
 692   return !is_initialized();
 693 }
 694 
 695 klassItable InstanceKlass::itable() const {
 696   return klassItable(const_cast<InstanceKlass*>(this));
 697 }
 698 
 699 void InstanceKlass::eager_initialize(Thread *thread) {
 700   if (!EagerInitialization) return;
 701 
 702   if (this->is_not_initialized()) {
 703     // abort if the the class has a class initializer
 704     if (this->class_initializer() != NULL) return;
 705 
 706     // abort if it is java.lang.Object (initialization is handled in genesis)
 707     Klass* super_klass = super();
 708     if (super_klass == NULL) return;
 709 
 710     // abort if the super class should be initialized
 711     if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
 712 
 713     // call body to expose the this pointer
 714     eager_initialize_impl();
 715   }
 716 }
 717 
 718 // JVMTI spec thinks there are signers and protection domain in the
 719 // instanceKlass.  These accessors pretend these fields are there.
 720 // The hprof specification also thinks these fields are in InstanceKlass.
 721 oop InstanceKlass::protection_domain() const {
 722   // return the protection_domain from the mirror
 723   return java_lang_Class::protection_domain(java_mirror());
 724 }
 725 
 726 // To remove these from requires an incompatible change and CCC request.
 727 objArrayOop InstanceKlass::signers() const {
 728   // return the signers from the mirror
 729   return java_lang_Class::signers(java_mirror());
 730 }
 731 
 732 oop InstanceKlass::init_lock() const {
 733   // return the init lock from the mirror
 734   oop lock = java_lang_Class::init_lock(java_mirror());
 735   // Prevent reordering with any access of initialization state
 736   OrderAccess::loadload();
 737   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
 738          "only fully initialized state can have a null lock");
 739   return lock;
 740 }
 741 
 742 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 743 // threads to get this lock will see a null lock and will not lock.
 744 // That's okay because they all check for initialized state after getting
 745 // the lock and return.
 746 void InstanceKlass::fence_and_clear_init_lock() {
 747   // make sure previous stores are all done, notably the init_state.
 748   OrderAccess::storestore();
 749   java_lang_Class::set_init_lock(java_mirror(), NULL);
 750   assert(!is_not_initialized(), "class must be initialized now");
 751 }
 752 
 753 void InstanceKlass::eager_initialize_impl() {
 754   EXCEPTION_MARK;
 755   HandleMark hm(THREAD);
 756   Handle h_init_lock(THREAD, init_lock());
 757   ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 758 
 759   // abort if someone beat us to the initialization
 760   if (!is_not_initialized()) return;  // note: not equivalent to is_initialized()
 761 
 762   ClassState old_state = init_state();
 763   link_class_impl(THREAD);
 764   if (HAS_PENDING_EXCEPTION) {
 765     CLEAR_PENDING_EXCEPTION;
 766     // Abort if linking the class throws an exception.
 767 
 768     // Use a test to avoid redundantly resetting the state if there's
 769     // no change.  Set_init_state() asserts that state changes make
 770     // progress, whereas here we might just be spinning in place.
 771     if (old_state != _init_state)
 772       set_init_state(old_state);
 773   } else {
 774     // linking successfull, mark class as initialized
 775     set_init_state(fully_initialized);
 776     fence_and_clear_init_lock();
 777     // trace
 778     if (log_is_enabled(Info, class, init)) {
 779       ResourceMark rm(THREAD);
 780       log_info(class, init)("[Initialized %s without side effects]", external_name());
 781     }
 782   }
 783 }
 784 
 785 
 786 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 787 // process. The step comments refers to the procedure described in that section.
 788 // Note: implementation moved to static method to expose the this pointer.
 789 void InstanceKlass::initialize(TRAPS) {
 790   if (this->should_be_initialized()) {
 791     initialize_impl(CHECK);
 792     // Note: at this point the class may be initialized
 793     //       OR it may be in the state of being initialized
 794     //       in case of recursive initialization!
 795   } else {
 796     assert(is_initialized(), "sanity check");
 797   }
 798 }
 799 
 800 
 801 bool InstanceKlass::verify_code(TRAPS) {
 802   // 1) Verify the bytecodes
 803   return Verifier::verify(this, should_verify_class(), THREAD);
 804 }
 805 
 806 void InstanceKlass::link_class(TRAPS) {
 807   assert(is_loaded(), "must be loaded");
 808   if (!is_linked()) {
 809     link_class_impl(CHECK);
 810   }
 811 }
 812 
 813 // Called to verify that a class can link during initialization, without
 814 // throwing a VerifyError.
 815 bool InstanceKlass::link_class_or_fail(TRAPS) {
 816   assert(is_loaded(), "must be loaded");
 817   if (!is_linked()) {
 818     link_class_impl(CHECK_false);
 819   }
 820   return is_linked();
 821 }
 822 
 823 bool InstanceKlass::link_class_impl(TRAPS) {
 824   if (DumpSharedSpaces && SystemDictionaryShared::has_class_failed_verification(this)) {
 825     // This is for CDS dumping phase only -- we use the in_error_state to indicate that
 826     // the class has failed verification. Throwing the NoClassDefFoundError here is just
 827     // a convenient way to stop repeat attempts to verify the same (bad) class.
 828     //
 829     // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
 830     // if we are executing Java code. This is not a problem for CDS dumping phase since
 831     // it doesn't execute any Java code.
 832     ResourceMark rm(THREAD);
 833     Exceptions::fthrow(THREAD_AND_LOCATION,
 834                        vmSymbols::java_lang_NoClassDefFoundError(),
 835                        "Class %s, or one of its supertypes, failed class initialization",
 836                        external_name());
 837     return false;
 838   }
 839   // return if already verified
 840   if (is_linked()) {
 841     return true;
 842   }
 843 
 844   // Timing
 845   // timer handles recursion
 846   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 847   JavaThread* jt = (JavaThread*)THREAD;
 848 
 849   // link super class before linking this class
 850   Klass* super_klass = super();
 851   if (super_klass != NULL) {
 852     if (super_klass->is_interface()) {  // check if super class is an interface
 853       ResourceMark rm(THREAD);
 854       Exceptions::fthrow(
 855         THREAD_AND_LOCATION,
 856         vmSymbols::java_lang_IncompatibleClassChangeError(),
 857         "class %s has interface %s as super class",
 858         external_name(),
 859         super_klass->external_name()
 860       );
 861       return false;
 862     }
 863 
 864     InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
 865     ik_super->link_class_impl(CHECK_false);
 866   }
 867 
 868   // link all interfaces implemented by this class before linking this class
 869   Array<InstanceKlass*>* interfaces = local_interfaces();
 870   int num_interfaces = interfaces->length();
 871   for (int index = 0; index < num_interfaces; index++) {
 872     InstanceKlass* interk = interfaces->at(index);
 873     interk->link_class_impl(CHECK_false);
 874   }
 875 
 876   // in case the class is linked in the process of linking its superclasses
 877   if (is_linked()) {
 878     return true;
 879   }
 880 
 881   // trace only the link time for this klass that includes
 882   // the verification time
 883   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 884                              ClassLoader::perf_class_link_selftime(),
 885                              ClassLoader::perf_classes_linked(),
 886                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 887                              jt->get_thread_stat()->perf_timers_addr(),
 888                              PerfClassTraceTime::CLASS_LINK);
 889 
 890   // verification & rewriting
 891   {
 892     HandleMark hm(THREAD);
 893     Handle h_init_lock(THREAD, init_lock());
 894     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 895     // rewritten will have been set if loader constraint error found
 896     // on an earlier link attempt
 897     // don't verify or rewrite if already rewritten
 898     //
 899 
 900     if (!is_linked()) {
 901       if (!is_rewritten()) {
 902         {
 903           bool verify_ok = verify_code(THREAD);
 904           if (!verify_ok) {
 905             return false;
 906           }
 907         }
 908 
 909         // Just in case a side-effect of verify linked this class already
 910         // (which can sometimes happen since the verifier loads classes
 911         // using custom class loaders, which are free to initialize things)
 912         if (is_linked()) {
 913           return true;
 914         }
 915 
 916         // also sets rewritten
 917         rewrite_class(CHECK_false);
 918       } else if (is_shared()) {
 919         SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
 920       }
 921 
 922       // relocate jsrs and link methods after they are all rewritten
 923       link_methods(CHECK_false);
 924 
 925       // Initialize the vtable and interface table after
 926       // methods have been rewritten since rewrite may
 927       // fabricate new Method*s.
 928       // also does loader constraint checking
 929       //
 930       // initialize_vtable and initialize_itable need to be rerun for
 931       // a shared class if the class is not loaded by the NULL classloader.
 932       ClassLoaderData * loader_data = class_loader_data();
 933       if (!(is_shared() &&
 934             loader_data->is_the_null_class_loader_data())) {
 935         vtable().initialize_vtable(true, CHECK_false);
 936         itable().initialize_itable(true, CHECK_false);
 937       }
 938 #ifdef ASSERT
 939       else {
 940         vtable().verify(tty, true);
 941         // In case itable verification is ever added.
 942         // itable().verify(tty, true);
 943       }
 944 #endif
 945       set_init_state(linked);
 946       if (JvmtiExport::should_post_class_prepare()) {
 947         Thread *thread = THREAD;
 948         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 949         JvmtiExport::post_class_prepare((JavaThread *) thread, this);
 950       }
 951     }
 952   }
 953   return true;
 954 }
 955 
 956 // Rewrite the byte codes of all of the methods of a class.
 957 // The rewriter must be called exactly once. Rewriting must happen after
 958 // verification but before the first method of the class is executed.
 959 void InstanceKlass::rewrite_class(TRAPS) {
 960   assert(is_loaded(), "must be loaded");
 961   if (is_rewritten()) {
 962     assert(is_shared(), "rewriting an unshared class?");
 963     return;
 964   }
 965   Rewriter::rewrite(this, CHECK);
 966   set_rewritten();
 967 }
 968 
 969 // Now relocate and link method entry points after class is rewritten.
 970 // This is outside is_rewritten flag. In case of an exception, it can be
 971 // executed more than once.
 972 void InstanceKlass::link_methods(TRAPS) {
 973   int len = methods()->length();
 974   for (int i = len-1; i >= 0; i--) {
 975     methodHandle m(THREAD, methods()->at(i));
 976 
 977     // Set up method entry points for compiler and interpreter    .
 978     m->link_method(m, CHECK);
 979   }
 980 }
 981 
 982 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
 983 void InstanceKlass::initialize_super_interfaces(TRAPS) {
 984   assert (has_nonstatic_concrete_methods(), "caller should have checked this");
 985   for (int i = 0; i < local_interfaces()->length(); ++i) {
 986     InstanceKlass* ik = local_interfaces()->at(i);
 987 
 988     // Initialization is depth first search ie. we start with top of the inheritance tree
 989     // has_nonstatic_concrete_methods drives searching superinterfaces since it
 990     // means has_nonstatic_concrete_methods in its superinterface hierarchy
 991     if (ik->has_nonstatic_concrete_methods()) {
 992       ik->initialize_super_interfaces(CHECK);
 993     }
 994 
 995     // Only initialize() interfaces that "declare" concrete methods.
 996     if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
 997       ik->initialize(CHECK);
 998     }
 999   }
1000 }
1001 
1002 void InstanceKlass::initialize_impl(TRAPS) {
1003   HandleMark hm(THREAD);
1004 
1005   // Make sure klass is linked (verified) before initialization
1006   // A class could already be verified, since it has been reflected upon.
1007   link_class(CHECK);
1008 
1009   DTRACE_CLASSINIT_PROBE(required, -1);
1010 
1011   bool wait = false;
1012 
1013   assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
1014   JavaThread* jt = (JavaThread*)THREAD;
1015 
1016   // refer to the JVM book page 47 for description of steps
1017   // Step 1
1018   {
1019     Handle h_init_lock(THREAD, init_lock());
1020     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
1021 
1022     // Step 2
1023     // If we were to use wait() instead of waitInterruptibly() then
1024     // we might end up throwing IE from link/symbol resolution sites
1025     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
1026     while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1027       wait = true;
1028       jt->set_class_to_be_initialized(this);
1029       ol.wait_uninterruptibly(jt);
1030       jt->set_class_to_be_initialized(NULL);
1031     }
1032 
1033     // Step 3
1034     if (is_being_initialized() && is_reentrant_initialization(jt)) {
1035       DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1036       return;
1037     }
1038 
1039     // Step 4
1040     if (is_initialized()) {
1041       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1042       return;
1043     }
1044 
1045     // Step 5
1046     if (is_in_error_state()) {
1047       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1048       ResourceMark rm(THREAD);
1049       const char* desc = "Could not initialize class ";
1050       const char* className = external_name();
1051       size_t msglen = strlen(desc) + strlen(className) + 1;
1052       char* message = NEW_RESOURCE_ARRAY(char, msglen);
1053       if (NULL == message) {
1054         // Out of memory: can't create detailed error message
1055           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
1056       } else {
1057         jio_snprintf(message, msglen, "%s%s", desc, className);
1058           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
1059       }
1060     }
1061 
1062     // Step 6
1063     set_init_state(being_initialized);
1064     set_init_thread(jt);
1065   }
1066 
1067   // Step 7
1068   // Next, if C is a class rather than an interface, initialize it's super class and super
1069   // interfaces.
1070   if (!is_interface()) {
1071     Klass* super_klass = super();
1072     if (super_klass != NULL && super_klass->should_be_initialized()) {
1073       super_klass->initialize(THREAD);
1074     }
1075     // If C implements any interface that declares a non-static, concrete method,
1076     // the initialization of C triggers initialization of its super interfaces.
1077     // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1078     // having a superinterface that declares, non-static, concrete methods
1079     if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1080       initialize_super_interfaces(THREAD);
1081     }
1082 
1083     // If any exceptions, complete abruptly, throwing the same exception as above.
1084     if (HAS_PENDING_EXCEPTION) {
1085       Handle e(THREAD, PENDING_EXCEPTION);
1086       CLEAR_PENDING_EXCEPTION;
1087       {
1088         EXCEPTION_MARK;
1089         // Locks object, set state, and notify all waiting threads
1090         set_initialization_state_and_notify(initialization_error, THREAD);
1091         CLEAR_PENDING_EXCEPTION;
1092       }
1093       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1094       THROW_OOP(e());
1095     }
1096   }
1097 
1098 
1099   // Look for aot compiled methods for this klass, including class initializer.
1100   AOTLoader::load_for_klass(this, THREAD);
1101 
1102   // Step 8
1103   {
1104     DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1105     // Timer includes any side effects of class initialization (resolution,
1106     // etc), but not recursive entry into call_class_initializer().
1107     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1108                              ClassLoader::perf_class_init_selftime(),
1109                              ClassLoader::perf_classes_inited(),
1110                              jt->get_thread_stat()->perf_recursion_counts_addr(),
1111                              jt->get_thread_stat()->perf_timers_addr(),
1112                              PerfClassTraceTime::CLASS_CLINIT);
1113     call_class_initializer(THREAD);
1114   }
1115 
1116   // Step 9
1117   if (!HAS_PENDING_EXCEPTION) {
1118     set_initialization_state_and_notify(fully_initialized, CHECK);
1119     {
1120       debug_only(vtable().verify(tty, true);)
1121     }
1122   }
1123   else {
1124     // Step 10 and 11
1125     Handle e(THREAD, PENDING_EXCEPTION);
1126     CLEAR_PENDING_EXCEPTION;
1127     // JVMTI has already reported the pending exception
1128     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1129     JvmtiExport::clear_detected_exception(jt);
1130     {
1131       EXCEPTION_MARK;
1132       set_initialization_state_and_notify(initialization_error, THREAD);
1133       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
1134       // JVMTI has already reported the pending exception
1135       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1136       JvmtiExport::clear_detected_exception(jt);
1137     }
1138     DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1139     if (e->is_a(SystemDictionary::Error_klass())) {
1140       THROW_OOP(e());
1141     } else {
1142       JavaCallArguments args(e);
1143       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1144                 vmSymbols::throwable_void_signature(),
1145                 &args);
1146     }
1147   }
1148   DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1149 }
1150 
1151 
1152 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1153   Handle h_init_lock(THREAD, init_lock());
1154   if (h_init_lock() != NULL) {
1155     ObjectLocker ol(h_init_lock, THREAD);
1156     set_init_thread(NULL); // reset _init_thread before changing _init_state
1157     set_init_state(state);
1158     fence_and_clear_init_lock();
1159     ol.notify_all(CHECK);
1160   } else {
1161     assert(h_init_lock() != NULL, "The initialization state should never be set twice");
1162     set_init_thread(NULL); // reset _init_thread before changing _init_state
1163     set_init_state(state);
1164   }
1165 }
1166 
1167 Klass* InstanceKlass::implementor() const {
1168   Klass* volatile* k = adr_implementor();
1169   if (k == NULL) {
1170     return NULL;
1171   } else {
1172     // This load races with inserts, and therefore needs acquire.
1173     Klass* kls = Atomic::load_acquire(k);
1174     if (kls != NULL && !kls->is_loader_alive()) {
1175       return NULL;  // don't return unloaded class
1176     } else {
1177       return kls;
1178     }
1179   }
1180 }
1181 
1182 
1183 void InstanceKlass::set_implementor(Klass* k) {
1184   assert_locked_or_safepoint(Compile_lock);
1185   assert(is_interface(), "not interface");
1186   Klass* volatile* addr = adr_implementor();
1187   assert(addr != NULL, "null addr");
1188   if (addr != NULL) {
1189     Atomic::release_store(addr, k);
1190   }
1191 }
1192 
1193 int  InstanceKlass::nof_implementors() const {
1194   Klass* k = implementor();
1195   if (k == NULL) {
1196     return 0;
1197   } else if (k != this) {
1198     return 1;
1199   } else {
1200     return 2;
1201   }
1202 }
1203 
1204 // The embedded _implementor field can only record one implementor.
1205 // When there are more than one implementors, the _implementor field
1206 // is set to the interface Klass* itself. Following are the possible
1207 // values for the _implementor field:
1208 //   NULL                  - no implementor
1209 //   implementor Klass*    - one implementor
1210 //   self                  - more than one implementor
1211 //
1212 // The _implementor field only exists for interfaces.
1213 void InstanceKlass::add_implementor(Klass* k) {
1214   if (Universe::is_fully_initialized()) {
1215     assert_lock_strong(Compile_lock);
1216   }
1217   assert(is_interface(), "not interface");
1218   // Filter out my subinterfaces.
1219   // (Note: Interfaces are never on the subklass list.)
1220   if (InstanceKlass::cast(k)->is_interface()) return;
1221 
1222   // Filter out subclasses whose supers already implement me.
1223   // (Note: CHA must walk subclasses of direct implementors
1224   // in order to locate indirect implementors.)
1225   Klass* sk = k->super();
1226   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
1227     // We only need to check one immediate superclass, since the
1228     // implements_interface query looks at transitive_interfaces.
1229     // Any supers of the super have the same (or fewer) transitive_interfaces.
1230     return;
1231 
1232   Klass* ik = implementor();
1233   if (ik == NULL) {
1234     set_implementor(k);
1235   } else if (ik != this && ik != k) {
1236     // There is already an implementor. Use itself as an indicator of
1237     // more than one implementors.
1238     set_implementor(this);
1239   }
1240 
1241   // The implementor also implements the transitive_interfaces
1242   for (int index = 0; index < local_interfaces()->length(); index++) {
1243     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
1244   }
1245 }
1246 
1247 void InstanceKlass::init_implementor() {
1248   if (is_interface()) {
1249     set_implementor(NULL);
1250   }
1251 }
1252 
1253 
1254 void InstanceKlass::process_interfaces(Thread *thread) {
1255   // link this class into the implementors list of every interface it implements
1256   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1257     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1258     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
1259     assert(interf->is_interface(), "expected interface");
1260     interf->add_implementor(this);
1261   }
1262 }
1263 
1264 bool InstanceKlass::can_be_primary_super_slow() const {
1265   if (is_interface())
1266     return false;
1267   else
1268     return Klass::can_be_primary_super_slow();
1269 }
1270 
1271 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1272                                                                Array<InstanceKlass*>* transitive_interfaces) {
1273   // The secondaries are the implemented interfaces.
1274   Array<InstanceKlass*>* interfaces = transitive_interfaces;
1275   int num_secondaries = num_extra_slots + interfaces->length();
1276   if (num_secondaries == 0) {
1277     // Must share this for correct bootstrapping!
1278     set_secondary_supers(Universe::the_empty_klass_array());
1279     return NULL;
1280   } else if (num_extra_slots == 0) {
1281     // The secondary super list is exactly the same as the transitive interfaces, so
1282     // let's use it instead of making a copy.
1283     // Redefine classes has to be careful not to delete this!
1284     // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1285     // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1286     set_secondary_supers((Array<Klass*>*)(address)interfaces);
1287     return NULL;
1288   } else {
1289     // Copy transitive interfaces to a temporary growable array to be constructed
1290     // into the secondary super list with extra slots.
1291     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1292     for (int i = 0; i < interfaces->length(); i++) {
1293       secondaries->push(interfaces->at(i));
1294     }
1295     return secondaries;
1296   }
1297 }
1298 
1299 bool InstanceKlass::implements_interface(Klass* k) const {
1300   if (this == k) return true;
1301   assert(k->is_interface(), "should be an interface class");
1302   for (int i = 0; i < transitive_interfaces()->length(); i++) {
1303     if (transitive_interfaces()->at(i) == k) {
1304       return true;
1305     }
1306   }
1307   return false;
1308 }
1309 
1310 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1311   // Verify direct super interface
1312   if (this == k) return true;
1313   assert(k->is_interface(), "should be an interface class");
1314   for (int i = 0; i < local_interfaces()->length(); i++) {
1315     if (local_interfaces()->at(i) == k) {
1316       return true;
1317     }
1318   }
1319   return false;
1320 }
1321 
1322 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1323   check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1324   int size = objArrayOopDesc::object_size(length);
1325   Klass* ak = array_klass(n, CHECK_NULL);
1326   objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1327                                                                 /* do_zero */ true, CHECK_NULL);
1328   return o;
1329 }
1330 
1331 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1332   if (TraceFinalizerRegistration) {
1333     tty->print("Registered ");
1334     i->print_value_on(tty);
1335     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1336   }
1337   instanceHandle h_i(THREAD, i);
1338   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1339   JavaValue result(T_VOID);
1340   JavaCallArguments args(h_i);
1341   methodHandle mh (THREAD, Universe::finalizer_register_method());
1342   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1343   return h_i();
1344 }
1345 
1346 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1347   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1348   int size = size_helper();  // Query before forming handle.
1349 
1350   instanceOop i;
1351 
1352   i = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1353   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1354     i = register_finalizer(i, CHECK_NULL);
1355   }
1356   return i;
1357 }
1358 
1359 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1360   return instanceHandle(THREAD, allocate_instance(THREAD));
1361 }
1362 
1363 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1364   if (is_interface() || is_abstract()) {
1365     ResourceMark rm(THREAD);
1366     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1367               : vmSymbols::java_lang_InstantiationException(), external_name());
1368   }
1369   if (this == SystemDictionary::Class_klass()) {
1370     ResourceMark rm(THREAD);
1371     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1372               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1373   }
1374 }
1375 
1376 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1377   // Need load-acquire for lock-free read
1378   if (array_klasses_acquire() == NULL) {
1379     if (or_null) return NULL;
1380 
1381     ResourceMark rm(THREAD);
1382     JavaThread *jt = (JavaThread *)THREAD;
1383     {
1384       // Atomic creation of array_klasses
1385       MutexLocker ma(THREAD, MultiArray_lock);
1386 
1387       // Check if update has already taken place
1388       if (array_klasses() == NULL) {
1389         Klass*    k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1390         // use 'release' to pair with lock-free load
1391         release_set_array_klasses(k);
1392       }
1393     }
1394   }
1395   // _this will always be set at this point
1396   ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1397   if (or_null) {
1398     return oak->array_klass_or_null(n);
1399   }
1400   return oak->array_klass(n, THREAD);
1401 }
1402 
1403 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1404   return array_klass_impl(or_null, 1, THREAD);
1405 }
1406 
1407 static int call_class_initializer_counter = 0;   // for debugging
1408 
1409 Method* InstanceKlass::class_initializer() const {
1410   Method* clinit = find_method(
1411       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1412   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1413     return clinit;
1414   }
1415   return NULL;
1416 }
1417 
1418 void InstanceKlass::call_class_initializer(TRAPS) {
1419   if (ReplayCompiles &&
1420       (ReplaySuppressInitializers == 1 ||
1421        (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1422     // Hide the existence of the initializer for the purpose of replaying the compile
1423     return;
1424   }
1425 
1426   methodHandle h_method(THREAD, class_initializer());
1427   assert(!is_initialized(), "we cannot initialize twice");
1428   LogTarget(Info, class, init) lt;
1429   if (lt.is_enabled()) {
1430     ResourceMark rm(THREAD);
1431     LogStream ls(lt);
1432     ls.print("%d Initializing ", call_class_initializer_counter++);
1433     name()->print_value_on(&ls);
1434     ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1435   }
1436   if (h_method() != NULL) {
1437     JavaCallArguments args; // No arguments
1438     JavaValue result(T_VOID);
1439     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1440   }
1441 }
1442 
1443 
1444 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1445   InterpreterOopMap* entry_for) {
1446   // Lazily create the _oop_map_cache at first request
1447   // Lock-free access requires load_acquire.
1448   OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1449   if (oop_map_cache == NULL) {
1450     MutexLocker x(OopMapCacheAlloc_lock);
1451     // Check if _oop_map_cache was allocated while we were waiting for this lock
1452     if ((oop_map_cache = _oop_map_cache) == NULL) {
1453       oop_map_cache = new OopMapCache();
1454       // Ensure _oop_map_cache is stable, since it is examined without a lock
1455       Atomic::release_store(&_oop_map_cache, oop_map_cache);
1456     }
1457   }
1458   // _oop_map_cache is constant after init; lookup below does its own locking.
1459   oop_map_cache->lookup(method, bci, entry_for);
1460 }
1461 
1462 bool InstanceKlass::contains_field_offset(int offset) {
1463   fieldDescriptor fd;
1464   return find_field_from_offset(offset, false, &fd);
1465 }
1466 
1467 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1468   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1469     Symbol* f_name = fs.name();
1470     Symbol* f_sig  = fs.signature();
1471     if (f_name == name && f_sig == sig) {
1472       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1473       return true;
1474     }
1475   }
1476   return false;
1477 }
1478 
1479 
1480 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1481   const int n = local_interfaces()->length();
1482   for (int i = 0; i < n; i++) {
1483     Klass* intf1 = local_interfaces()->at(i);
1484     assert(intf1->is_interface(), "just checking type");
1485     // search for field in current interface
1486     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1487       assert(fd->is_static(), "interface field must be static");
1488       return intf1;
1489     }
1490     // search for field in direct superinterfaces
1491     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1492     if (intf2 != NULL) return intf2;
1493   }
1494   // otherwise field lookup fails
1495   return NULL;
1496 }
1497 
1498 
1499 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1500   // search order according to newest JVM spec (5.4.3.2, p.167).
1501   // 1) search for field in current klass
1502   if (find_local_field(name, sig, fd)) {
1503     return const_cast<InstanceKlass*>(this);
1504   }
1505   // 2) search for field recursively in direct superinterfaces
1506   { Klass* intf = find_interface_field(name, sig, fd);
1507     if (intf != NULL) return intf;
1508   }
1509   // 3) apply field lookup recursively if superclass exists
1510   { Klass* supr = super();
1511     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1512   }
1513   // 4) otherwise field lookup fails
1514   return NULL;
1515 }
1516 
1517 
1518 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1519   // search order according to newest JVM spec (5.4.3.2, p.167).
1520   // 1) search for field in current klass
1521   if (find_local_field(name, sig, fd)) {
1522     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1523   }
1524   // 2) search for field recursively in direct superinterfaces
1525   if (is_static) {
1526     Klass* intf = find_interface_field(name, sig, fd);
1527     if (intf != NULL) return intf;
1528   }
1529   // 3) apply field lookup recursively if superclass exists
1530   { Klass* supr = super();
1531     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1532   }
1533   // 4) otherwise field lookup fails
1534   return NULL;
1535 }
1536 
1537 
1538 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1539   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1540     if (fs.offset() == offset) {
1541       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1542       if (fd->is_static() == is_static) return true;
1543     }
1544   }
1545   return false;
1546 }
1547 
1548 
1549 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1550   Klass* klass = const_cast<InstanceKlass*>(this);
1551   while (klass != NULL) {
1552     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1553       return true;
1554     }
1555     klass = klass->super();
1556   }
1557   return false;
1558 }
1559 
1560 
1561 void InstanceKlass::methods_do(void f(Method* method)) {
1562   // Methods aren't stable until they are loaded.  This can be read outside
1563   // a lock through the ClassLoaderData for profiling
1564   if (!is_loaded()) {
1565     return;
1566   }
1567 
1568   int len = methods()->length();
1569   for (int index = 0; index < len; index++) {
1570     Method* m = methods()->at(index);
1571     assert(m->is_method(), "must be method");
1572     f(m);
1573   }
1574 }
1575 
1576 
1577 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1578   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1579     if (fs.access_flags().is_static()) {
1580       fieldDescriptor& fd = fs.field_descriptor();
1581       cl->do_field(&fd);
1582     }
1583   }
1584 }
1585 
1586 
1587 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1588   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1589     if (fs.access_flags().is_static()) {
1590       fieldDescriptor& fd = fs.field_descriptor();
1591       f(&fd, mirror, CHECK);
1592     }
1593   }
1594 }
1595 
1596 
1597 static int compare_fields_by_offset(int* a, int* b) {
1598   return a[0] - b[0];
1599 }
1600 
1601 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1602   InstanceKlass* super = superklass();
1603   if (super != NULL) {
1604     super->do_nonstatic_fields(cl);
1605   }
1606   fieldDescriptor fd;
1607   int length = java_fields_count();
1608   // In DebugInfo nonstatic fields are sorted by offset.
1609   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1610   int j = 0;
1611   for (int i = 0; i < length; i += 1) {
1612     fd.reinitialize(this, i);
1613     if (!fd.is_static()) {
1614       fields_sorted[j + 0] = fd.offset();
1615       fields_sorted[j + 1] = i;
1616       j += 2;
1617     }
1618   }
1619   if (j > 0) {
1620     length = j;
1621     // _sort_Fn is defined in growableArray.hpp.
1622     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1623     for (int i = 0; i < length; i += 2) {
1624       fd.reinitialize(this, fields_sorted[i + 1]);
1625       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1626       cl->do_field(&fd);
1627     }
1628   }
1629   FREE_C_HEAP_ARRAY(int, fields_sorted);
1630 }
1631 
1632 
1633 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1634   if (array_klasses() != NULL)
1635     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1636 }
1637 
1638 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1639   if (array_klasses() != NULL)
1640     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1641 }
1642 
1643 #ifdef ASSERT
1644 static int linear_search(const Array<Method*>* methods,
1645                          const Symbol* name,
1646                          const Symbol* signature) {
1647   const int len = methods->length();
1648   for (int index = 0; index < len; index++) {
1649     const Method* const m = methods->at(index);
1650     assert(m->is_method(), "must be method");
1651     if (m->signature() == signature && m->name() == name) {
1652        return index;
1653     }
1654   }
1655   return -1;
1656 }
1657 #endif
1658 
1659 bool InstanceKlass::_disable_method_binary_search = false;
1660 
1661 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1662   int len = methods->length();
1663   int l = 0;
1664   int h = len - 1;
1665   while (l <= h) {
1666     Method* m = methods->at(l);
1667     if (m->name() == name) {
1668       return l;
1669     }
1670     l++;
1671   }
1672   return -1;
1673 }
1674 
1675 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1676   if (_disable_method_binary_search) {
1677     assert(DynamicDumpSharedSpaces, "must be");
1678     // At the final stage of dynamic dumping, the methods array may not be sorted
1679     // by ascending addresses of their names, so we can't use binary search anymore.
1680     // However, methods with the same name are still laid out consecutively inside the
1681     // methods array, so let's look for the first one that matches.
1682     return linear_search(methods, name);
1683   }
1684 
1685   int len = methods->length();
1686   int l = 0;
1687   int h = len - 1;
1688 
1689   // methods are sorted by ascending addresses of their names, so do binary search
1690   while (l <= h) {
1691     int mid = (l + h) >> 1;
1692     Method* m = methods->at(mid);
1693     assert(m->is_method(), "must be method");
1694     int res = m->name()->fast_compare(name);
1695     if (res == 0) {
1696       return mid;
1697     } else if (res < 0) {
1698       l = mid + 1;
1699     } else {
1700       h = mid - 1;
1701     }
1702   }
1703   return -1;
1704 }
1705 
1706 // find_method looks up the name/signature in the local methods array
1707 Method* InstanceKlass::find_method(const Symbol* name,
1708                                    const Symbol* signature) const {
1709   return find_method_impl(name, signature, find_overpass, find_static, find_private);
1710 }
1711 
1712 Method* InstanceKlass::find_method_impl(const Symbol* name,
1713                                         const Symbol* signature,
1714                                         OverpassLookupMode overpass_mode,
1715                                         StaticLookupMode static_mode,
1716                                         PrivateLookupMode private_mode) const {
1717   return InstanceKlass::find_method_impl(methods(),
1718                                          name,
1719                                          signature,
1720                                          overpass_mode,
1721                                          static_mode,
1722                                          private_mode);
1723 }
1724 
1725 // find_instance_method looks up the name/signature in the local methods array
1726 // and skips over static methods
1727 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1728                                             const Symbol* name,
1729                                             const Symbol* signature,
1730                                             PrivateLookupMode private_mode) {
1731   Method* const meth = InstanceKlass::find_method_impl(methods,
1732                                                  name,
1733                                                  signature,
1734                                                  find_overpass,
1735                                                  skip_static,
1736                                                  private_mode);
1737   assert(((meth == NULL) || !meth->is_static()),
1738     "find_instance_method should have skipped statics");
1739   return meth;
1740 }
1741 
1742 // find_instance_method looks up the name/signature in the local methods array
1743 // and skips over static methods
1744 Method* InstanceKlass::find_instance_method(const Symbol* name,
1745                                             const Symbol* signature,
1746                                             PrivateLookupMode private_mode) const {
1747   return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1748 }
1749 
1750 // Find looks up the name/signature in the local methods array
1751 // and filters on the overpass, static and private flags
1752 // This returns the first one found
1753 // note that the local methods array can have up to one overpass, one static
1754 // and one instance (private or not) with the same name/signature
1755 Method* InstanceKlass::find_local_method(const Symbol* name,
1756                                          const Symbol* signature,
1757                                          OverpassLookupMode overpass_mode,
1758                                          StaticLookupMode static_mode,
1759                                          PrivateLookupMode private_mode) const {
1760   return InstanceKlass::find_method_impl(methods(),
1761                                          name,
1762                                          signature,
1763                                          overpass_mode,
1764                                          static_mode,
1765                                          private_mode);
1766 }
1767 
1768 // Find looks up the name/signature in the local methods array
1769 // and filters on the overpass, static and private flags
1770 // This returns the first one found
1771 // note that the local methods array can have up to one overpass, one static
1772 // and one instance (private or not) with the same name/signature
1773 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1774                                          const Symbol* name,
1775                                          const Symbol* signature,
1776                                          OverpassLookupMode overpass_mode,
1777                                          StaticLookupMode static_mode,
1778                                          PrivateLookupMode private_mode) {
1779   return InstanceKlass::find_method_impl(methods,
1780                                          name,
1781                                          signature,
1782                                          overpass_mode,
1783                                          static_mode,
1784                                          private_mode);
1785 }
1786 
1787 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1788                                    const Symbol* name,
1789                                    const Symbol* signature) {
1790   return InstanceKlass::find_method_impl(methods,
1791                                          name,
1792                                          signature,
1793                                          find_overpass,
1794                                          find_static,
1795                                          find_private);
1796 }
1797 
1798 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1799                                         const Symbol* name,
1800                                         const Symbol* signature,
1801                                         OverpassLookupMode overpass_mode,
1802                                         StaticLookupMode static_mode,
1803                                         PrivateLookupMode private_mode) {
1804   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1805   return hit >= 0 ? methods->at(hit): NULL;
1806 }
1807 
1808 // true if method matches signature and conforms to skipping_X conditions.
1809 static bool method_matches(const Method* m,
1810                            const Symbol* signature,
1811                            bool skipping_overpass,
1812                            bool skipping_static,
1813                            bool skipping_private) {
1814   return ((m->signature() == signature) &&
1815     (!skipping_overpass || !m->is_overpass()) &&
1816     (!skipping_static || !m->is_static()) &&
1817     (!skipping_private || !m->is_private()));
1818 }
1819 
1820 // Used directly for default_methods to find the index into the
1821 // default_vtable_indices, and indirectly by find_method
1822 // find_method_index looks in the local methods array to return the index
1823 // of the matching name/signature. If, overpass methods are being ignored,
1824 // the search continues to find a potential non-overpass match.  This capability
1825 // is important during method resolution to prefer a static method, for example,
1826 // over an overpass method.
1827 // There is the possibility in any _method's array to have the same name/signature
1828 // for a static method, an overpass method and a local instance method
1829 // To correctly catch a given method, the search criteria may need
1830 // to explicitly skip the other two. For local instance methods, it
1831 // is often necessary to skip private methods
1832 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1833                                      const Symbol* name,
1834                                      const Symbol* signature,
1835                                      OverpassLookupMode overpass_mode,
1836                                      StaticLookupMode static_mode,
1837                                      PrivateLookupMode private_mode) {
1838   const bool skipping_overpass = (overpass_mode == skip_overpass);
1839   const bool skipping_static = (static_mode == skip_static);
1840   const bool skipping_private = (private_mode == skip_private);
1841   const int hit = quick_search(methods, name);
1842   if (hit != -1) {
1843     const Method* const m = methods->at(hit);
1844 
1845     // Do linear search to find matching signature.  First, quick check
1846     // for common case, ignoring overpasses if requested.
1847     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1848       return hit;
1849     }
1850 
1851     // search downwards through overloaded methods
1852     int i;
1853     for (i = hit - 1; i >= 0; --i) {
1854         const Method* const m = methods->at(i);
1855         assert(m->is_method(), "must be method");
1856         if (m->name() != name) {
1857           break;
1858         }
1859         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1860           return i;
1861         }
1862     }
1863     // search upwards
1864     for (i = hit + 1; i < methods->length(); ++i) {
1865         const Method* const m = methods->at(i);
1866         assert(m->is_method(), "must be method");
1867         if (m->name() != name) {
1868           break;
1869         }
1870         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1871           return i;
1872         }
1873     }
1874     // not found
1875 #ifdef ASSERT
1876     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1877       linear_search(methods, name, signature);
1878     assert(-1 == index, "binary search should have found entry %d", index);
1879 #endif
1880   }
1881   return -1;
1882 }
1883 
1884 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1885   return find_method_by_name(methods(), name, end);
1886 }
1887 
1888 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1889                                        const Symbol* name,
1890                                        int* end_ptr) {
1891   assert(end_ptr != NULL, "just checking");
1892   int start = quick_search(methods, name);
1893   int end = start + 1;
1894   if (start != -1) {
1895     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1896     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1897     *end_ptr = end;
1898     return start;
1899   }
1900   return -1;
1901 }
1902 
1903 // uncached_lookup_method searches both the local class methods array and all
1904 // superclasses methods arrays, skipping any overpass methods in superclasses,
1905 // and possibly skipping private methods.
1906 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1907                                               const Symbol* signature,
1908                                               OverpassLookupMode overpass_mode,
1909                                               PrivateLookupMode private_mode) const {
1910   OverpassLookupMode overpass_local_mode = overpass_mode;
1911   const Klass* klass = this;
1912   while (klass != NULL) {
1913     Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1914                                                                         signature,
1915                                                                         overpass_local_mode,
1916                                                                         find_static,
1917                                                                         private_mode);
1918     if (method != NULL) {
1919       return method;
1920     }
1921     klass = klass->super();
1922     overpass_local_mode = skip_overpass;   // Always ignore overpass methods in superclasses
1923   }
1924   return NULL;
1925 }
1926 
1927 #ifdef ASSERT
1928 // search through class hierarchy and return true if this class or
1929 // one of the superclasses was redefined
1930 bool InstanceKlass::has_redefined_this_or_super() const {
1931   const Klass* klass = this;
1932   while (klass != NULL) {
1933     if (InstanceKlass::cast(klass)->has_been_redefined()) {
1934       return true;
1935     }
1936     klass = klass->super();
1937   }
1938   return false;
1939 }
1940 #endif
1941 
1942 // lookup a method in the default methods list then in all transitive interfaces
1943 // Do NOT return private or static methods
1944 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1945                                                          Symbol* signature) const {
1946   Method* m = NULL;
1947   if (default_methods() != NULL) {
1948     m = find_method(default_methods(), name, signature);
1949   }
1950   // Look up interfaces
1951   if (m == NULL) {
1952     m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1953   }
1954   return m;
1955 }
1956 
1957 // lookup a method in all the interfaces that this class implements
1958 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1959 // They should only be found in the initial InterfaceMethodRef
1960 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1961                                                        Symbol* signature,
1962                                                        DefaultsLookupMode defaults_mode) const {
1963   Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1964   int num_ifs = all_ifs->length();
1965   InstanceKlass *ik = NULL;
1966   for (int i = 0; i < num_ifs; i++) {
1967     ik = all_ifs->at(i);
1968     Method* m = ik->lookup_method(name, signature);
1969     if (m != NULL && m->is_public() && !m->is_static() &&
1970         ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1971       return m;
1972     }
1973   }
1974   return NULL;
1975 }
1976 
1977 /* jni_id_for_impl for jfieldIds only */
1978 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1979   MutexLocker ml(JfieldIdCreation_lock);
1980   // Retry lookup after we got the lock
1981   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1982   if (probe == NULL) {
1983     // Slow case, allocate new static field identifier
1984     probe = new JNIid(this, offset, jni_ids());
1985     set_jni_ids(probe);
1986   }
1987   return probe;
1988 }
1989 
1990 
1991 /* jni_id_for for jfieldIds only */
1992 JNIid* InstanceKlass::jni_id_for(int offset) {
1993   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1994   if (probe == NULL) {
1995     probe = jni_id_for_impl(offset);
1996   }
1997   return probe;
1998 }
1999 
2000 u2 InstanceKlass::enclosing_method_data(int offset) const {
2001   const Array<jushort>* const inner_class_list = inner_classes();
2002   if (inner_class_list == NULL) {
2003     return 0;
2004   }
2005   const int length = inner_class_list->length();
2006   if (length % inner_class_next_offset == 0) {
2007     return 0;
2008   }
2009   const int index = length - enclosing_method_attribute_size;
2010   assert(offset < enclosing_method_attribute_size, "invalid offset");
2011   return inner_class_list->at(index + offset);
2012 }
2013 
2014 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2015                                                  u2 method_index) {
2016   Array<jushort>* inner_class_list = inner_classes();
2017   assert (inner_class_list != NULL, "_inner_classes list is not set up");
2018   int length = inner_class_list->length();
2019   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2020     int index = length - enclosing_method_attribute_size;
2021     inner_class_list->at_put(
2022       index + enclosing_method_class_index_offset, class_index);
2023     inner_class_list->at_put(
2024       index + enclosing_method_method_index_offset, method_index);
2025   }
2026 }
2027 
2028 // Lookup or create a jmethodID.
2029 // This code is called by the VMThread and JavaThreads so the
2030 // locking has to be done very carefully to avoid deadlocks
2031 // and/or other cache consistency problems.
2032 //
2033 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2034   size_t idnum = (size_t)method_h->method_idnum();
2035   jmethodID* jmeths = methods_jmethod_ids_acquire();
2036   size_t length = 0;
2037   jmethodID id = NULL;
2038 
2039   // We use a double-check locking idiom here because this cache is
2040   // performance sensitive. In the normal system, this cache only
2041   // transitions from NULL to non-NULL which is safe because we use
2042   // release_set_methods_jmethod_ids() to advertise the new cache.
2043   // A partially constructed cache should never be seen by a racing
2044   // thread. We also use release_store() to save a new jmethodID
2045   // in the cache so a partially constructed jmethodID should never be
2046   // seen either. Cache reads of existing jmethodIDs proceed without a
2047   // lock, but cache writes of a new jmethodID requires uniqueness and
2048   // creation of the cache itself requires no leaks so a lock is
2049   // generally acquired in those two cases.
2050   //
2051   // If the RedefineClasses() API has been used, then this cache can
2052   // grow and we'll have transitions from non-NULL to bigger non-NULL.
2053   // Cache creation requires no leaks and we require safety between all
2054   // cache accesses and freeing of the old cache so a lock is generally
2055   // acquired when the RedefineClasses() API has been used.
2056 
2057   if (jmeths != NULL) {
2058     // the cache already exists
2059     if (!idnum_can_increment()) {
2060       // the cache can't grow so we can just get the current values
2061       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2062     } else {
2063       // cache can grow so we have to be more careful
2064       if (Threads::number_of_threads() == 0 ||
2065           SafepointSynchronize::is_at_safepoint()) {
2066         // we're single threaded or at a safepoint - no locking needed
2067         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2068       } else {
2069         MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2070         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2071       }
2072     }
2073   }
2074   // implied else:
2075   // we need to allocate a cache so default length and id values are good
2076 
2077   if (jmeths == NULL ||   // no cache yet
2078       length <= idnum ||  // cache is too short
2079       id == NULL) {       // cache doesn't contain entry
2080 
2081     // This function can be called by the VMThread so we have to do all
2082     // things that might block on a safepoint before grabbing the lock.
2083     // Otherwise, we can deadlock with the VMThread or have a cache
2084     // consistency issue. These vars keep track of what we might have
2085     // to free after the lock is dropped.
2086     jmethodID  to_dealloc_id     = NULL;
2087     jmethodID* to_dealloc_jmeths = NULL;
2088 
2089     // may not allocate new_jmeths or use it if we allocate it
2090     jmethodID* new_jmeths = NULL;
2091     if (length <= idnum) {
2092       // allocate a new cache that might be used
2093       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
2094       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
2095       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
2096       // cache size is stored in element[0], other elements offset by one
2097       new_jmeths[0] = (jmethodID)size;
2098     }
2099 
2100     // allocate a new jmethodID that might be used
2101     jmethodID new_id = NULL;
2102     if (method_h->is_old() && !method_h->is_obsolete()) {
2103       // The method passed in is old (but not obsolete), we need to use the current version
2104       Method* current_method = method_with_idnum((int)idnum);
2105       assert(current_method != NULL, "old and but not obsolete, so should exist");
2106       new_id = Method::make_jmethod_id(class_loader_data(), current_method);
2107     } else {
2108       // It is the current version of the method or an obsolete method,
2109       // use the version passed in
2110       new_id = Method::make_jmethod_id(class_loader_data(), method_h());
2111     }
2112 
2113     if (Threads::number_of_threads() == 0 ||
2114         SafepointSynchronize::is_at_safepoint()) {
2115       // we're single threaded or at a safepoint - no locking needed
2116       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2117                                           &to_dealloc_id, &to_dealloc_jmeths);
2118     } else {
2119       MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2120       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2121                                           &to_dealloc_id, &to_dealloc_jmeths);
2122     }
2123 
2124     // The lock has been dropped so we can free resources.
2125     // Free up either the old cache or the new cache if we allocated one.
2126     if (to_dealloc_jmeths != NULL) {
2127       FreeHeap(to_dealloc_jmeths);
2128     }
2129     // free up the new ID since it wasn't needed
2130     if (to_dealloc_id != NULL) {
2131       Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
2132     }
2133   }
2134   return id;
2135 }
2136 
2137 // Figure out how many jmethodIDs haven't been allocated, and make
2138 // sure space for them is pre-allocated.  This makes getting all
2139 // method ids much, much faster with classes with more than 8
2140 // methods, and has a *substantial* effect on performance with jvmti
2141 // code that loads all jmethodIDs for all classes.
2142 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2143   int new_jmeths = 0;
2144   int length = methods()->length();
2145   for (int index = start_offset; index < length; index++) {
2146     Method* m = methods()->at(index);
2147     jmethodID id = m->find_jmethod_id_or_null();
2148     if (id == NULL) {
2149       new_jmeths++;
2150     }
2151   }
2152   if (new_jmeths != 0) {
2153     Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2154   }
2155 }
2156 
2157 // Common code to fetch the jmethodID from the cache or update the
2158 // cache with the new jmethodID. This function should never do anything
2159 // that causes the caller to go to a safepoint or we can deadlock with
2160 // the VMThread or have cache consistency issues.
2161 //
2162 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
2163             size_t idnum, jmethodID new_id,
2164             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
2165             jmethodID** to_dealloc_jmeths_p) {
2166   assert(new_id != NULL, "sanity check");
2167   assert(to_dealloc_id_p != NULL, "sanity check");
2168   assert(to_dealloc_jmeths_p != NULL, "sanity check");
2169   assert(Threads::number_of_threads() == 0 ||
2170          SafepointSynchronize::is_at_safepoint() ||
2171          JmethodIdCreation_lock->owned_by_self(), "sanity check");
2172 
2173   // reacquire the cache - we are locked, single threaded or at a safepoint
2174   jmethodID* jmeths = methods_jmethod_ids_acquire();
2175   jmethodID  id     = NULL;
2176   size_t     length = 0;
2177 
2178   if (jmeths == NULL ||                         // no cache yet
2179       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
2180     if (jmeths != NULL) {
2181       // copy any existing entries from the old cache
2182       for (size_t index = 0; index < length; index++) {
2183         new_jmeths[index+1] = jmeths[index+1];
2184       }
2185       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
2186     }
2187     release_set_methods_jmethod_ids(jmeths = new_jmeths);
2188   } else {
2189     // fetch jmethodID (if any) from the existing cache
2190     id = jmeths[idnum+1];
2191     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
2192   }
2193   if (id == NULL) {
2194     // No matching jmethodID in the existing cache or we have a new
2195     // cache or we just grew the cache. This cache write is done here
2196     // by the first thread to win the foot race because a jmethodID
2197     // needs to be unique once it is generally available.
2198     id = new_id;
2199 
2200     // The jmethodID cache can be read while unlocked so we have to
2201     // make sure the new jmethodID is complete before installing it
2202     // in the cache.
2203     Atomic::release_store(&jmeths[idnum+1], id);
2204   } else {
2205     *to_dealloc_id_p = new_id; // save new id for later delete
2206   }
2207   return id;
2208 }
2209 
2210 
2211 // Common code to get the jmethodID cache length and the jmethodID
2212 // value at index idnum if there is one.
2213 //
2214 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
2215        size_t idnum, size_t *length_p, jmethodID* id_p) {
2216   assert(cache != NULL, "sanity check");
2217   assert(length_p != NULL, "sanity check");
2218   assert(id_p != NULL, "sanity check");
2219 
2220   // cache size is stored in element[0], other elements offset by one
2221   *length_p = (size_t)cache[0];
2222   if (*length_p <= idnum) {  // cache is too short
2223     *id_p = NULL;
2224   } else {
2225     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
2226   }
2227 }
2228 
2229 
2230 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
2231 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2232   size_t idnum = (size_t)method->method_idnum();
2233   jmethodID* jmeths = methods_jmethod_ids_acquire();
2234   size_t length;                                // length assigned as debugging crumb
2235   jmethodID id = NULL;
2236   if (jmeths != NULL &&                         // If there is a cache
2237       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
2238     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
2239   }
2240   return id;
2241 }
2242 
2243 inline DependencyContext InstanceKlass::dependencies() {
2244   DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2245   return dep_context;
2246 }
2247 
2248 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
2249   return dependencies().mark_dependent_nmethods(changes);
2250 }
2251 
2252 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2253   dependencies().add_dependent_nmethod(nm);
2254 }
2255 
2256 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
2257   dependencies().remove_dependent_nmethod(nm);
2258 }
2259 
2260 void InstanceKlass::clean_dependency_context() {
2261   dependencies().clean_unloading_dependents();
2262 }
2263 
2264 #ifndef PRODUCT
2265 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2266   dependencies().print_dependent_nmethods(verbose);
2267 }
2268 
2269 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2270   return dependencies().is_dependent_nmethod(nm);
2271 }
2272 #endif //PRODUCT
2273 
2274 void InstanceKlass::clean_weak_instanceklass_links() {
2275   clean_implementors_list();
2276   clean_method_data();
2277 }
2278 
2279 void InstanceKlass::clean_implementors_list() {
2280   assert(is_loader_alive(), "this klass should be live");
2281   if (is_interface()) {
2282     assert (ClassUnloading, "only called for ClassUnloading");
2283     for (;;) {
2284       // Use load_acquire due to competing with inserts
2285       Klass* impl = Atomic::load_acquire(adr_implementor());
2286       if (impl != NULL && !impl->is_loader_alive()) {
2287         // NULL this field, might be an unloaded klass or NULL
2288         Klass* volatile* klass = adr_implementor();
2289         if (Atomic::cmpxchg(klass, impl, (Klass*)NULL) == impl) {
2290           // Successfully unlinking implementor.
2291           if (log_is_enabled(Trace, class, unload)) {
2292             ResourceMark rm;
2293             log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2294           }
2295           return;
2296         }
2297       } else {
2298         return;
2299       }
2300     }
2301   }
2302 }
2303 
2304 void InstanceKlass::clean_method_data() {
2305   for (int m = 0; m < methods()->length(); m++) {
2306     MethodData* mdo = methods()->at(m)->method_data();
2307     if (mdo != NULL) {
2308       MutexLocker ml(SafepointSynchronize::is_at_safepoint() ? NULL : mdo->extra_data_lock());
2309       mdo->clean_method_data(/*always_clean*/false);
2310     }
2311   }
2312 }
2313 
2314 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
2315   if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
2316     ResourceMark rm;
2317     log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
2318     return false;
2319   }
2320 
2321   Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
2322   if (local_interfaces != NULL) {
2323     int length = local_interfaces->length();
2324     for (int i = 0; i < length; i++) {
2325       InstanceKlass* intf = local_interfaces->at(i);
2326       if (!intf->has_passed_fingerprint_check()) {
2327         ResourceMark rm;
2328         log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
2329         return false;
2330       }
2331     }
2332   }
2333 
2334   return true;
2335 }
2336 
2337 bool InstanceKlass::should_store_fingerprint(bool is_hidden_or_anonymous) {
2338 #if INCLUDE_AOT
2339   // We store the fingerprint into the InstanceKlass only in the following 2 cases:
2340   if (CalculateClassFingerprint) {
2341     // (1) We are running AOT to generate a shared library.
2342     return true;
2343   }
2344   if (Arguments::is_dumping_archive()) {
2345     // (2) We are running -Xshare:dump or -XX:ArchiveClassesAtExit to create a shared archive
2346     return true;
2347   }
2348   if (UseAOT && is_hidden_or_anonymous) {
2349     // (3) We are using AOT code from a shared library and see a hidden or unsafe anonymous class
2350     return true;
2351   }
2352 #endif
2353 
2354   // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
2355   // but do not store the 64-bit fingerprint to save space.
2356   return false;
2357 }
2358 
2359 bool InstanceKlass::has_stored_fingerprint() const {
2360 #if INCLUDE_AOT
2361   return should_store_fingerprint() || is_shared();
2362 #else
2363   return false;
2364 #endif
2365 }
2366 
2367 uint64_t InstanceKlass::get_stored_fingerprint() const {
2368   address adr = adr_fingerprint();
2369   if (adr != NULL) {
2370     return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
2371   }
2372   return 0;
2373 }
2374 
2375 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
2376   address adr = adr_fingerprint();
2377   if (adr != NULL) {
2378     Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2379 
2380     ResourceMark rm;
2381     log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2382   }
2383 }
2384 
2385 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2386   Klass::metaspace_pointers_do(it);
2387 
2388   if (log_is_enabled(Trace, cds)) {
2389     ResourceMark rm;
2390     log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2391   }
2392 
2393   it->push(&_annotations);
2394   it->push((Klass**)&_array_klasses);
2395   it->push(&_constants);
2396   it->push(&_inner_classes);
2397   it->push(&_array_name);
2398 #if INCLUDE_JVMTI
2399   it->push(&_previous_versions);
2400 #endif
2401   it->push(&_methods);
2402   it->push(&_default_methods);
2403   it->push(&_local_interfaces);
2404   it->push(&_transitive_interfaces);
2405   it->push(&_method_ordering);
2406   it->push(&_default_vtable_indices);
2407   it->push(&_fields);
2408 
2409   if (itable_length() > 0) {
2410     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2411     int method_table_offset_in_words = ioe->offset()/wordSize;
2412     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2413                          / itableOffsetEntry::size();
2414 
2415     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2416       if (ioe->interface_klass() != NULL) {
2417         it->push(ioe->interface_klass_addr());
2418         itableMethodEntry* ime = ioe->first_method_entry(this);
2419         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2420         for (int index = 0; index < n; index ++) {
2421           it->push(ime[index].method_addr());
2422         }
2423       }
2424     }
2425   }
2426 
2427   it->push(&_nest_members);
2428   it->push(&_record_components);
2429 }
2430 
2431 void InstanceKlass::remove_unshareable_info() {
2432   Klass::remove_unshareable_info();
2433 
2434   if (SystemDictionaryShared::has_class_failed_verification(this)) {
2435     // Classes are attempted to link during dumping and may fail,
2436     // but these classes are still in the dictionary and class list in CLD.
2437     // If the class has failed verification, there is nothing else to remove.
2438     return;
2439   }
2440 
2441   // Reset to the 'allocated' state to prevent any premature accessing to
2442   // a shared class at runtime while the class is still being loaded and
2443   // restored. A class' init_state is set to 'loaded' at runtime when it's
2444   // being added to class hierarchy (see SystemDictionary:::add_to_hierarchy()).
2445   _init_state = allocated;
2446 
2447   { // Otherwise this needs to take out the Compile_lock.
2448     assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2449     init_implementor();
2450   }
2451 
2452   constants()->remove_unshareable_info();
2453 
2454   for (int i = 0; i < methods()->length(); i++) {
2455     Method* m = methods()->at(i);
2456     m->remove_unshareable_info();
2457   }
2458 
2459   // do array classes also.
2460   if (array_klasses() != NULL) {
2461     array_klasses()->remove_unshareable_info();
2462   }
2463 
2464   // These are not allocated from metaspace. They are safe to set to NULL.
2465   _source_debug_extension = NULL;
2466   _dep_context = NULL;
2467   _osr_nmethods_head = NULL;
2468 #if INCLUDE_JVMTI
2469   _breakpoints = NULL;
2470   _previous_versions = NULL;
2471   _cached_class_file = NULL;
2472   _jvmti_cached_class_field_map = NULL;
2473 #endif
2474 
2475   _init_thread = NULL;
2476   _methods_jmethod_ids = NULL;
2477   _jni_ids = NULL;
2478   _oop_map_cache = NULL;
2479   // clear _nest_host to ensure re-load at runtime
2480   _nest_host = NULL;
2481   _nest_host_res_error = NULL;
2482   _package_entry = NULL;
2483   _dep_context_last_cleaned = 0;
2484 }
2485 
2486 void InstanceKlass::remove_java_mirror() {
2487   Klass::remove_java_mirror();
2488 
2489   // do array classes also.
2490   if (array_klasses() != NULL) {
2491     array_klasses()->remove_java_mirror();
2492   }
2493 }
2494 
2495 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2496   // SystemDictionary::add_to_hierarchy() sets the init_state to loaded
2497   // before the InstanceKlass is added to the SystemDictionary. Make
2498   // sure the current state is <loaded.
2499   assert(!is_loaded(), "invalid init state");
2500   set_package(loader_data, CHECK);
2501   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2502 
2503   Array<Method*>* methods = this->methods();
2504   int num_methods = methods->length();
2505   for (int index = 0; index < num_methods; ++index) {
2506     methods->at(index)->restore_unshareable_info(CHECK);
2507   }
2508   if (JvmtiExport::has_redefined_a_class()) {
2509     // Reinitialize vtable because RedefineClasses may have changed some
2510     // entries in this vtable for super classes so the CDS vtable might
2511     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2512     // vtables in the shared system dictionary, only the main one.
2513     // It also redefines the itable too so fix that too.
2514     vtable().initialize_vtable(false, CHECK);
2515     itable().initialize_itable(false, CHECK);
2516   }
2517 
2518   // restore constant pool resolved references
2519   constants()->restore_unshareable_info(CHECK);
2520 
2521   if (array_klasses() != NULL) {
2522     // Array classes have null protection domain.
2523     // --> see ArrayKlass::complete_create_array_klass()
2524     array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2525   }
2526 
2527   // Initialize current biased locking state.
2528   if (UseBiasedLocking && BiasedLocking::enabled()) {
2529     set_prototype_header(markWord::biased_locking_prototype());
2530   }
2531 }
2532 
2533 void InstanceKlass::set_shared_class_loader_type(s2 loader_type) {
2534   switch (loader_type) {
2535   case ClassLoader::BOOT_LOADER:
2536     _misc_flags |= _misc_is_shared_boot_class;
2537     break;
2538   case ClassLoader::PLATFORM_LOADER:
2539     _misc_flags |= _misc_is_shared_platform_class;
2540     break;
2541   case ClassLoader::APP_LOADER:
2542     _misc_flags |= _misc_is_shared_app_class;
2543     break;
2544   default:
2545     ShouldNotReachHere();
2546     break;
2547   }
2548 }
2549 
2550 #if INCLUDE_JVMTI
2551 static void clear_all_breakpoints(Method* m) {
2552   m->clear_all_breakpoints();
2553 }
2554 #endif
2555 
2556 void InstanceKlass::unload_class(InstanceKlass* ik) {
2557   // Release dependencies.
2558   ik->dependencies().remove_all_dependents();
2559 
2560   // notify the debugger
2561   if (JvmtiExport::should_post_class_unload()) {
2562     JvmtiExport::post_class_unload(ik);
2563   }
2564 
2565   // notify ClassLoadingService of class unload
2566   ClassLoadingService::notify_class_unloaded(ik);
2567 
2568   if (Arguments::is_dumping_archive()) {
2569     SystemDictionaryShared::remove_dumptime_info(ik);
2570   }
2571 
2572   if (log_is_enabled(Info, class, unload)) {
2573     ResourceMark rm;
2574     log_info(class, unload)("unloading class %s " INTPTR_FORMAT, ik->external_name(), p2i(ik));
2575   }
2576 
2577   Events::log_class_unloading(Thread::current(), ik);
2578 
2579 #if INCLUDE_JFR
2580   assert(ik != NULL, "invariant");
2581   EventClassUnload event;
2582   event.set_unloadedClass(ik);
2583   event.set_definingClassLoader(ik->class_loader_data());
2584   event.commit();
2585 #endif
2586 }
2587 
2588 static void method_release_C_heap_structures(Method* m) {
2589   m->release_C_heap_structures();
2590 }
2591 
2592 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2593   // Clean up C heap
2594   ik->release_C_heap_structures();
2595   ik->constants()->release_C_heap_structures();
2596 
2597   // Deallocate and call destructors for MDO mutexes
2598   ik->methods_do(method_release_C_heap_structures);
2599 
2600 }
2601 
2602 void InstanceKlass::release_C_heap_structures() {
2603   // Can't release the constant pool here because the constant pool can be
2604   // deallocated separately from the InstanceKlass for default methods and
2605   // redefine classes.
2606 
2607   // Deallocate oop map cache
2608   if (_oop_map_cache != NULL) {
2609     delete _oop_map_cache;
2610     _oop_map_cache = NULL;
2611   }
2612 
2613   // Deallocate JNI identifiers for jfieldIDs
2614   JNIid::deallocate(jni_ids());
2615   set_jni_ids(NULL);
2616 
2617   jmethodID* jmeths = methods_jmethod_ids_acquire();
2618   if (jmeths != (jmethodID*)NULL) {
2619     release_set_methods_jmethod_ids(NULL);
2620     FreeHeap(jmeths);
2621   }
2622 
2623   assert(_dep_context == NULL,
2624          "dependencies should already be cleaned");
2625 
2626 #if INCLUDE_JVMTI
2627   // Deallocate breakpoint records
2628   if (breakpoints() != 0x0) {
2629     methods_do(clear_all_breakpoints);
2630     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2631   }
2632 
2633   // deallocate the cached class file
2634   if (_cached_class_file != NULL) {
2635     os::free(_cached_class_file);
2636     _cached_class_file = NULL;
2637   }
2638 #endif
2639 
2640   // Decrement symbol reference counts associated with the unloaded class.
2641   if (_name != NULL) _name->decrement_refcount();
2642 
2643   // unreference array name derived from this class name (arrays of an unloaded
2644   // class can't be referenced anymore).
2645   if (_array_name != NULL)  _array_name->decrement_refcount();
2646   FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2647 
2648   // deallocate memoized nest-host resolution error
2649   if (_nest_host_res_error != NULL) {
2650     FREE_C_HEAP_ARRAY(char, _nest_host_res_error);
2651     _nest_host_res_error = NULL;
2652   }
2653 }
2654 
2655 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2656   if (array == NULL) {
2657     _source_debug_extension = NULL;
2658   } else {
2659     // Adding one to the attribute length in order to store a null terminator
2660     // character could cause an overflow because the attribute length is
2661     // already coded with an u4 in the classfile, but in practice, it's
2662     // unlikely to happen.
2663     assert((length+1) > length, "Overflow checking");
2664     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2665     for (int i = 0; i < length; i++) {
2666       sde[i] = array[i];
2667     }
2668     sde[length] = '\0';
2669     _source_debug_extension = sde;
2670   }
2671 }
2672 
2673 const char* InstanceKlass::signature_name() const {
2674   int hash_len = 0;
2675   char hash_buf[40];
2676 
2677   // If this is an unsafe anonymous class, append a hash to make the name unique
2678   if (is_unsafe_anonymous()) {
2679     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2680     jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2681     hash_len = (int)strlen(hash_buf);
2682   }
2683 
2684   // Get the internal name as a c string
2685   const char* src = (const char*) (name()->as_C_string());
2686   const int src_length = (int)strlen(src);
2687 
2688   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2689 
2690   // Add L as type indicator
2691   int dest_index = 0;
2692   dest[dest_index++] = JVM_SIGNATURE_CLASS;
2693 
2694   // Add the actual class name
2695   for (int src_index = 0; src_index < src_length; ) {
2696     dest[dest_index++] = src[src_index++];
2697   }
2698 
2699   if (is_hidden()) { // Replace the last '+' with a '.'.
2700     for (int index = (int)src_length; index > 0; index--) {
2701       if (dest[index] == '+') {
2702         dest[index] = JVM_SIGNATURE_DOT;
2703         break;
2704       }
2705     }
2706   }
2707 
2708   // If we have a hash, append it
2709   for (int hash_index = 0; hash_index < hash_len; ) {
2710     dest[dest_index++] = hash_buf[hash_index++];
2711   }
2712 
2713   // Add the semicolon and the NULL
2714   dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
2715   dest[dest_index] = '\0';
2716   return dest;
2717 }
2718 
2719 // Used to obtain the package name from a fully qualified class name.
2720 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2721   if (name == NULL) {
2722     return NULL;
2723   } else {
2724     if (name->utf8_length() <= 0) {
2725       return NULL;
2726     }
2727     ResourceMark rm(THREAD);
2728     const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2729     if (package_name == NULL) {
2730       return NULL;
2731     }
2732     Symbol* pkg_name = SymbolTable::new_symbol(package_name);
2733     return pkg_name;
2734   }
2735 }
2736 
2737 ModuleEntry* InstanceKlass::module() const {
2738   // For an unsafe anonymous class return the host class' module
2739   if (is_unsafe_anonymous()) {
2740     assert(unsafe_anonymous_host() != NULL, "unsafe anonymous class must have a host class");
2741     return unsafe_anonymous_host()->module();
2742   }
2743 
2744   if (is_hidden() &&
2745       in_unnamed_package() &&
2746       class_loader_data()->is_shortlived()) {
2747     // For a weak hidden class defined to an unnamed package,
2748     // the short-lived CLD will not have an unnamed module created for it.
2749     // Two choices to find the correct ModuleEntry:
2750     // 1. If hidden class is within a nest, use nest host's module
2751     // 2. Find the unnamed module off from the class loader
2752     // For now option #2 is used since a nest host is not set until
2753     // after the instance class is created in jvm_lookup_define_class().
2754     if (class_loader_data()->is_boot_class_loader_data()) {
2755       return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
2756     } else {
2757       oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
2758       assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
2759       return java_lang_Module::module_entry(module);
2760     }
2761   }
2762 
2763   // Class is in a named package
2764   if (!in_unnamed_package()) {
2765     return _package_entry->module();
2766   }
2767 
2768   // Class is in an unnamed package, return its loader's unnamed module
2769   return class_loader_data()->unnamed_module();
2770 }
2771 
2772 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2773 
2774   // ensure java/ packages only loaded by boot or platform builtin loaders
2775   check_prohibited_package(name(), loader_data, CHECK);
2776 
2777   TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2778 
2779   if (pkg_name != NULL && loader_data != NULL) {
2780 
2781     // Find in class loader's package entry table.
2782     _package_entry = loader_data->packages()->lookup_only(pkg_name);
2783 
2784     // If the package name is not found in the loader's package
2785     // entry table, it is an indication that the package has not
2786     // been defined. Consider it defined within the unnamed module.
2787     if (_package_entry == NULL) {
2788       ResourceMark rm(THREAD);
2789 
2790       if (!ModuleEntryTable::javabase_defined()) {
2791         // Before java.base is defined during bootstrapping, define all packages in
2792         // the java.base module.  If a non-java.base package is erroneously placed
2793         // in the java.base module it will be caught later when java.base
2794         // is defined by ModuleEntryTable::verify_javabase_packages check.
2795         assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2796         _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2797       } else {
2798         assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2799         _package_entry = loader_data->packages()->lookup(pkg_name,
2800                                                          loader_data->unnamed_module());
2801       }
2802 
2803       // A package should have been successfully created
2804       assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2805              name()->as_C_string(), loader_data->loader_name_and_id());
2806     }
2807 
2808     if (log_is_enabled(Debug, module)) {
2809       ResourceMark rm(THREAD);
2810       ModuleEntry* m = _package_entry->module();
2811       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2812                         external_name(),
2813                         pkg_name->as_C_string(),
2814                         loader_data->loader_name_and_id(),
2815                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2816     }
2817   } else {
2818     ResourceMark rm(THREAD);
2819     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2820                       external_name(),
2821                       (loader_data != NULL) ? loader_data->loader_name_and_id() : "NULL",
2822                       UNNAMED_MODULE);
2823   }
2824 }
2825 
2826 
2827 // different versions of is_same_class_package
2828 
2829 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2830   oop classloader1 = this->class_loader();
2831   PackageEntry* classpkg1 = this->package();
2832   if (class2->is_objArray_klass()) {
2833     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2834   }
2835 
2836   oop classloader2;
2837   PackageEntry* classpkg2;
2838   if (class2->is_instance_klass()) {
2839     classloader2 = class2->class_loader();
2840     classpkg2 = class2->package();
2841   } else {
2842     assert(class2->is_typeArray_klass(), "should be type array");
2843     classloader2 = NULL;
2844     classpkg2 = NULL;
2845   }
2846 
2847   // Same package is determined by comparing class loader
2848   // and package entries. Both must be the same. This rule
2849   // applies even to classes that are defined in the unnamed
2850   // package, they still must have the same class loader.
2851   if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2852     return true;
2853   }
2854 
2855   return false;
2856 }
2857 
2858 // return true if this class and other_class are in the same package. Classloader
2859 // and classname information is enough to determine a class's package
2860 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2861                                           const Symbol* other_class_name) const {
2862   if (class_loader() != other_class_loader) {
2863     return false;
2864   }
2865   if (name()->fast_compare(other_class_name) == 0) {
2866      return true;
2867   }
2868 
2869   {
2870     ResourceMark rm;
2871 
2872     bool bad_class_name = false;
2873     const char* other_pkg =
2874       ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2875     if (bad_class_name) {
2876       return false;
2877     }
2878     // Check that package_from_name() returns NULL, not "", if there is no package.
2879     assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2880 
2881     const Symbol* const this_package_name =
2882       this->package() != NULL ? this->package()->name() : NULL;
2883 
2884     if (this_package_name == NULL || other_pkg == NULL) {
2885       // One of the two doesn't have a package.  Only return true if the other
2886       // one also doesn't have a package.
2887       return (const char*)this_package_name == other_pkg;
2888     }
2889 
2890     // Check if package is identical
2891     return this_package_name->equals(other_pkg);
2892   }
2893 }
2894 
2895 // Returns true iff super_method can be overridden by a method in targetclassname
2896 // See JLS 3rd edition 8.4.6.1
2897 // Assumes name-signature match
2898 // "this" is InstanceKlass of super_method which must exist
2899 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2900 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2901    // Private methods can not be overridden
2902    if (super_method->is_private()) {
2903      return false;
2904    }
2905    // If super method is accessible, then override
2906    if ((super_method->is_protected()) ||
2907        (super_method->is_public())) {
2908      return true;
2909    }
2910    // Package-private methods are not inherited outside of package
2911    assert(super_method->is_package_private(), "must be package private");
2912    return(is_same_class_package(targetclassloader(), targetclassname));
2913 }
2914 
2915 // Only boot and platform class loaders can define classes in "java/" packages.
2916 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2917                                              ClassLoaderData* loader_data,
2918                                              TRAPS) {
2919   if (!loader_data->is_boot_class_loader_data() &&
2920       !loader_data->is_platform_class_loader_data() &&
2921       class_name != NULL) {
2922     ResourceMark rm(THREAD);
2923     char* name = class_name->as_C_string();
2924     if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2925       TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2926       assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2927       name = pkg_name->as_C_string();
2928       const char* class_loader_name = loader_data->loader_name_and_id();
2929       StringUtils::replace_no_expand(name, "/", ".");
2930       const char* msg_text1 = "Class loader (instance of): ";
2931       const char* msg_text2 = " tried to load prohibited package name: ";
2932       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2933       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2934       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2935       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2936     }
2937   }
2938   return;
2939 }
2940 
2941 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2942   constantPoolHandle i_cp(THREAD, constants());
2943   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2944     int ioff = iter.inner_class_info_index();
2945     if (ioff != 0) {
2946       // Check to see if the name matches the class we're looking for
2947       // before attempting to find the class.
2948       if (i_cp->klass_name_at_matches(this, ioff)) {
2949         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2950         if (this == inner_klass) {
2951           *ooff = iter.outer_class_info_index();
2952           *noff = iter.inner_name_index();
2953           return true;
2954         }
2955       }
2956     }
2957   }
2958   return false;
2959 }
2960 
2961 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2962   InstanceKlass* outer_klass = NULL;
2963   *inner_is_member = false;
2964   int ooff = 0, noff = 0;
2965   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2966   if (has_inner_classes_attr) {
2967     constantPoolHandle i_cp(THREAD, constants());
2968     if (ooff != 0) {
2969       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2970       outer_klass = InstanceKlass::cast(ok);
2971       *inner_is_member = true;
2972     }
2973     if (NULL == outer_klass) {
2974       // It may be a local or anonymous class; try for that.
2975       int encl_method_class_idx = enclosing_method_class_index();
2976       if (encl_method_class_idx != 0) {
2977         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2978         outer_klass = InstanceKlass::cast(ok);
2979         *inner_is_member = false;
2980       }
2981     }
2982   }
2983 
2984   // If no inner class attribute found for this class.
2985   if (NULL == outer_klass) return NULL;
2986 
2987   // Throws an exception if outer klass has not declared k as an inner klass
2988   // We need evidence that each klass knows about the other, or else
2989   // the system could allow a spoof of an inner class to gain access rights.
2990   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2991   return outer_klass;
2992 }
2993 
2994 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2995   jint access = access_flags().as_int();
2996 
2997   // But check if it happens to be member class.
2998   InnerClassesIterator iter(this);
2999   for (; !iter.done(); iter.next()) {
3000     int ioff = iter.inner_class_info_index();
3001     // Inner class attribute can be zero, skip it.
3002     // Strange but true:  JVM spec. allows null inner class refs.
3003     if (ioff == 0) continue;
3004 
3005     // only look at classes that are already loaded
3006     // since we are looking for the flags for our self.
3007     Symbol* inner_name = constants()->klass_name_at(ioff);
3008     if (name() == inner_name) {
3009       // This is really a member class.
3010       access = iter.inner_access_flags();
3011       break;
3012     }
3013   }
3014   // Remember to strip ACC_SUPER bit
3015   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
3016 }
3017 
3018 jint InstanceKlass::jvmti_class_status() const {
3019   jint result = 0;
3020 
3021   if (is_linked()) {
3022     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3023   }
3024 
3025   if (is_initialized()) {
3026     assert(is_linked(), "Class status is not consistent");
3027     result |= JVMTI_CLASS_STATUS_INITIALIZED;
3028   }
3029   if (is_in_error_state()) {
3030     result |= JVMTI_CLASS_STATUS_ERROR;
3031   }
3032   return result;
3033 }
3034 
3035 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
3036   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
3037   int method_table_offset_in_words = ioe->offset()/wordSize;
3038   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
3039                        / itableOffsetEntry::size();
3040 
3041   for (int cnt = 0 ; ; cnt ++, ioe ++) {
3042     // If the interface isn't implemented by the receiver class,
3043     // the VM should throw IncompatibleClassChangeError.
3044     if (cnt >= nof_interfaces) {
3045       ResourceMark rm(THREAD);
3046       stringStream ss;
3047       bool same_module = (module() == holder->module());
3048       ss.print("Receiver class %s does not implement "
3049                "the interface %s defining the method to be called "
3050                "(%s%s%s)",
3051                external_name(), holder->external_name(),
3052                (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3053                (same_module) ? "" : "; ",
3054                (same_module) ? "" : holder->class_in_module_of_loader());
3055       THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3056     }
3057 
3058     Klass* ik = ioe->interface_klass();
3059     if (ik == holder) break;
3060   }
3061 
3062   itableMethodEntry* ime = ioe->first_method_entry(this);
3063   Method* m = ime[index].method();
3064   if (m == NULL) {
3065     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3066   }
3067   return m;
3068 }
3069 
3070 
3071 #if INCLUDE_JVMTI
3072 // update default_methods for redefineclasses for methods that are
3073 // not yet in the vtable due to concurrent subclass define and superinterface
3074 // redefinition
3075 // Note: those in the vtable, should have been updated via adjust_method_entries
3076 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3077   // search the default_methods for uses of either obsolete or EMCP methods
3078   if (default_methods() != NULL) {
3079     for (int index = 0; index < default_methods()->length(); index ++) {
3080       Method* old_method = default_methods()->at(index);
3081       if (old_method == NULL || !old_method->is_old()) {
3082         continue; // skip uninteresting entries
3083       }
3084       assert(!old_method->is_deleted(), "default methods may not be deleted");
3085       Method* new_method = old_method->get_new_method();
3086       default_methods()->at_put(index, new_method);
3087 
3088       if (log_is_enabled(Info, redefine, class, update)) {
3089         ResourceMark rm;
3090         if (!(*trace_name_printed)) {
3091           log_info(redefine, class, update)
3092             ("adjust: klassname=%s default methods from name=%s",
3093              external_name(), old_method->method_holder()->external_name());
3094           *trace_name_printed = true;
3095         }
3096         log_debug(redefine, class, update, vtables)
3097           ("default method update: %s(%s) ",
3098            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3099       }
3100     }
3101   }
3102 }
3103 #endif // INCLUDE_JVMTI
3104 
3105 // On-stack replacement stuff
3106 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3107   assert_lock_strong(CompiledMethod_lock);
3108 #ifndef PRODUCT
3109   if (TieredCompilation) {
3110       nmethod * prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3111       assert(prev == NULL || !prev->is_in_use(),
3112       "redundunt OSR recompilation detected. memory leak in CodeCache!");
3113   }
3114 #endif
3115   // only one compilation can be active
3116   {
3117     assert(n->is_osr_method(), "wrong kind of nmethod");
3118     n->set_osr_link(osr_nmethods_head());
3119     set_osr_nmethods_head(n);
3120     // Raise the highest osr level if necessary
3121     if (TieredCompilation) {
3122       Method* m = n->method();
3123       m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
3124     }
3125   }
3126 
3127   // Get rid of the osr methods for the same bci that have lower levels.
3128   if (TieredCompilation) {
3129     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3130       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3131       if (inv != NULL && inv->is_in_use()) {
3132         inv->make_not_entrant();
3133       }
3134     }
3135   }
3136 }
3137 
3138 // Remove osr nmethod from the list. Return true if found and removed.
3139 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3140   // This is a short non-blocking critical region, so the no safepoint check is ok.
3141   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock
3142                  , Mutex::_no_safepoint_check_flag);
3143   assert(n->is_osr_method(), "wrong kind of nmethod");
3144   nmethod* last = NULL;
3145   nmethod* cur  = osr_nmethods_head();
3146   int max_level = CompLevel_none;  // Find the max comp level excluding n
3147   Method* m = n->method();
3148   // Search for match
3149   bool found = false;
3150   while(cur != NULL && cur != n) {
3151     if (TieredCompilation && m == cur->method()) {
3152       // Find max level before n
3153       max_level = MAX2(max_level, cur->comp_level());
3154     }
3155     last = cur;
3156     cur = cur->osr_link();
3157   }
3158   nmethod* next = NULL;
3159   if (cur == n) {
3160     found = true;
3161     next = cur->osr_link();
3162     if (last == NULL) {
3163       // Remove first element
3164       set_osr_nmethods_head(next);
3165     } else {
3166       last->set_osr_link(next);
3167     }
3168   }
3169   n->set_osr_link(NULL);
3170   if (TieredCompilation) {
3171     cur = next;
3172     while (cur != NULL) {
3173       // Find max level after n
3174       if (m == cur->method()) {
3175         max_level = MAX2(max_level, cur->comp_level());
3176       }
3177       cur = cur->osr_link();
3178     }
3179     m->set_highest_osr_comp_level(max_level);
3180   }
3181   return found;
3182 }
3183 
3184 int InstanceKlass::mark_osr_nmethods(const Method* m) {
3185   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock,
3186                  Mutex::_no_safepoint_check_flag);
3187   nmethod* osr = osr_nmethods_head();
3188   int found = 0;
3189   while (osr != NULL) {
3190     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3191     if (osr->method() == m) {
3192       osr->mark_for_deoptimization();
3193       found++;
3194     }
3195     osr = osr->osr_link();
3196   }
3197   return found;
3198 }
3199 
3200 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3201   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock,
3202                  Mutex::_no_safepoint_check_flag);
3203   nmethod* osr = osr_nmethods_head();
3204   nmethod* best = NULL;
3205   while (osr != NULL) {
3206     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3207     // There can be a time when a c1 osr method exists but we are waiting
3208     // for a c2 version. When c2 completes its osr nmethod we will trash
3209     // the c1 version and only be able to find the c2 version. However
3210     // while we overflow in the c1 code at back branches we don't want to
3211     // try and switch to the same code as we are already running
3212 
3213     if (osr->method() == m &&
3214         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3215       if (match_level) {
3216         if (osr->comp_level() == comp_level) {
3217           // Found a match - return it.
3218           return osr;
3219         }
3220       } else {
3221         if (best == NULL || (osr->comp_level() > best->comp_level())) {
3222           if (osr->comp_level() == CompLevel_highest_tier) {
3223             // Found the best possible - return it.
3224             return osr;
3225           }
3226           best = osr;
3227         }
3228       }
3229     }
3230     osr = osr->osr_link();
3231   }
3232 
3233   assert(match_level == false || best == NULL, "shouldn't pick up anything if match_level is set");
3234   if (best != NULL && best->comp_level() >= comp_level) {
3235     return best;
3236   }
3237   return NULL;
3238 }
3239 
3240 // -----------------------------------------------------------------------------------------------------
3241 // Printing
3242 
3243 #ifndef PRODUCT
3244 
3245 #define BULLET  " - "
3246 
3247 static const char* state_names[] = {
3248   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3249 };
3250 
3251 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3252   for (int i = 0; i < len; i++) {
3253     intptr_t e = start[i];
3254     st->print("%d : " INTPTR_FORMAT, i, e);
3255     if (MetaspaceObj::is_valid((Metadata*)e)) {
3256       st->print(" ");
3257       ((Metadata*)e)->print_value_on(st);
3258     }
3259     st->cr();
3260   }
3261 }
3262 
3263 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3264   return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3265 }
3266 
3267 void InstanceKlass::print_on(outputStream* st) const {
3268   assert(is_klass(), "must be klass");
3269   Klass::print_on(st);
3270 
3271   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
3272   st->print(BULLET"klass size:        %d", size());                               st->cr();
3273   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
3274   st->print(BULLET"state:             "); st->print_cr("%s", state_names[_init_state]);
3275   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
3276   st->print(BULLET"super:             "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3277   st->print(BULLET"sub:               ");
3278   Klass* sub = subklass();
3279   int n;
3280   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
3281     if (n < MaxSubklassPrintSize) {
3282       sub->print_value_on(st);
3283       st->print("   ");
3284     }
3285   }
3286   if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3287   st->cr();
3288 
3289   if (is_interface()) {
3290     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
3291     if (nof_implementors() == 1) {
3292       st->print_cr(BULLET"implementor:    ");
3293       st->print("   ");
3294       implementor()->print_value_on(st);
3295       st->cr();
3296     }
3297   }
3298 
3299   st->print(BULLET"arrays:            "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3300   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
3301   if (Verbose || WizardMode) {
3302     Array<Method*>* method_array = methods();
3303     for (int i = 0; i < method_array->length(); i++) {
3304       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3305     }
3306   }
3307   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
3308   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
3309   if (Verbose && default_methods() != NULL) {
3310     Array<Method*>* method_array = default_methods();
3311     for (int i = 0; i < method_array->length(); i++) {
3312       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3313     }
3314   }
3315   if (default_vtable_indices() != NULL) {
3316     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
3317   }
3318   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
3319   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3320   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
3321   if (class_loader_data() != NULL) {
3322     st->print(BULLET"class loader data:  ");
3323     class_loader_data()->print_value_on(st);
3324     st->cr();
3325   }
3326   st->print(BULLET"unsafe anonymous host class:        "); Metadata::print_value_on_maybe_null(st, unsafe_anonymous_host()); st->cr();
3327   if (source_file_name() != NULL) {
3328     st->print(BULLET"source file:       ");
3329     source_file_name()->print_value_on(st);
3330     st->cr();
3331   }
3332   if (source_debug_extension() != NULL) {
3333     st->print(BULLET"source debug extension:       ");
3334     st->print("%s", source_debug_extension());
3335     st->cr();
3336   }
3337   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
3338   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
3339   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
3340   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
3341   {
3342     bool have_pv = false;
3343     // previous versions are linked together through the InstanceKlass
3344     for (InstanceKlass* pv_node = previous_versions();
3345          pv_node != NULL;
3346          pv_node = pv_node->previous_versions()) {
3347       if (!have_pv)
3348         st->print(BULLET"previous version:  ");
3349       have_pv = true;
3350       pv_node->constants()->print_value_on(st);
3351     }
3352     if (have_pv) st->cr();
3353   }
3354 
3355   if (generic_signature() != NULL) {
3356     st->print(BULLET"generic signature: ");
3357     generic_signature()->print_value_on(st);
3358     st->cr();
3359   }
3360   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
3361   st->print(BULLET"nest members:     "); nest_members()->print_value_on(st);     st->cr();
3362   if (record_components() != NULL) {
3363     st->print(BULLET"record components:     "); record_components()->print_value_on(st);     st->cr();
3364   }
3365   if (java_mirror() != NULL) {
3366     st->print(BULLET"java mirror:       ");
3367     java_mirror()->print_value_on(st);
3368     st->cr();
3369   } else {
3370     st->print_cr(BULLET"java mirror:       NULL");
3371   }
3372   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3373   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
3374   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3375   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
3376   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3377   FieldPrinter print_static_field(st);
3378   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3379   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3380   FieldPrinter print_nonstatic_field(st);
3381   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3382   ik->do_nonstatic_fields(&print_nonstatic_field);
3383 
3384   st->print(BULLET"non-static oop maps: ");
3385   OopMapBlock* map     = start_of_nonstatic_oop_maps();
3386   OopMapBlock* end_map = map + nonstatic_oop_map_count();
3387   while (map < end_map) {
3388     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3389     map++;
3390   }
3391   st->cr();
3392 }
3393 
3394 #endif //PRODUCT
3395 
3396 void InstanceKlass::print_value_on(outputStream* st) const {
3397   assert(is_klass(), "must be klass");
3398   if (Verbose || WizardMode)  access_flags().print_on(st);
3399   name()->print_value_on(st);
3400 }
3401 
3402 #ifndef PRODUCT
3403 
3404 void FieldPrinter::do_field(fieldDescriptor* fd) {
3405   _st->print(BULLET);
3406    if (_obj == NULL) {
3407      fd->print_on(_st);
3408      _st->cr();
3409    } else {
3410      fd->print_on_for(_st, _obj);
3411      _st->cr();
3412    }
3413 }
3414 
3415 
3416 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3417   Klass::oop_print_on(obj, st);
3418 
3419   if (this == SystemDictionary::String_klass()) {
3420     typeArrayOop value  = java_lang_String::value(obj);
3421     juint        length = java_lang_String::length(obj);
3422     if (value != NULL &&
3423         value->is_typeArray() &&
3424         length <= (juint) value->length()) {
3425       st->print(BULLET"string: ");
3426       java_lang_String::print(obj, st);
3427       st->cr();
3428       if (!WizardMode)  return;  // that is enough
3429     }
3430   }
3431 
3432   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3433   FieldPrinter print_field(st, obj);
3434   do_nonstatic_fields(&print_field);
3435 
3436   if (this == SystemDictionary::Class_klass()) {
3437     st->print(BULLET"signature: ");
3438     java_lang_Class::print_signature(obj, st);
3439     st->cr();
3440     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3441     st->print(BULLET"fake entry for mirror: ");
3442     Metadata::print_value_on_maybe_null(st, mirrored_klass);
3443     st->cr();
3444     Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3445     st->print(BULLET"fake entry for array: ");
3446     Metadata::print_value_on_maybe_null(st, array_klass);
3447     st->cr();
3448     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3449     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3450     Klass* real_klass = java_lang_Class::as_Klass(obj);
3451     if (real_klass != NULL && real_klass->is_instance_klass()) {
3452       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3453     }
3454   } else if (this == SystemDictionary::MethodType_klass()) {
3455     st->print(BULLET"signature: ");
3456     java_lang_invoke_MethodType::print_signature(obj, st);
3457     st->cr();
3458   }
3459 }
3460 
3461 bool InstanceKlass::verify_itable_index(int i) {
3462   int method_count = klassItable::method_count_for_interface(this);
3463   assert(i >= 0 && i < method_count, "index out of bounds");
3464   return true;
3465 }
3466 
3467 #endif //PRODUCT
3468 
3469 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3470   st->print("a ");
3471   name()->print_value_on(st);
3472   obj->print_address_on(st);
3473   if (this == SystemDictionary::String_klass()
3474       && java_lang_String::value(obj) != NULL) {
3475     ResourceMark rm;
3476     int len = java_lang_String::length(obj);
3477     int plen = (len < 24 ? len : 12);
3478     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3479     st->print(" = \"%s\"", str);
3480     if (len > plen)
3481       st->print("...[%d]", len);
3482   } else if (this == SystemDictionary::Class_klass()) {
3483     Klass* k = java_lang_Class::as_Klass(obj);
3484     st->print(" = ");
3485     if (k != NULL) {
3486       k->print_value_on(st);
3487     } else {
3488       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3489       st->print("%s", tname ? tname : "type?");
3490     }
3491   } else if (this == SystemDictionary::MethodType_klass()) {
3492     st->print(" = ");
3493     java_lang_invoke_MethodType::print_signature(obj, st);
3494   } else if (java_lang_boxing_object::is_instance(obj)) {
3495     st->print(" = ");
3496     java_lang_boxing_object::print(obj, st);
3497   } else if (this == SystemDictionary::LambdaForm_klass()) {
3498     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3499     if (vmentry != NULL) {
3500       st->print(" => ");
3501       vmentry->print_value_on(st);
3502     }
3503   } else if (this == SystemDictionary::MemberName_klass()) {
3504     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3505     if (vmtarget != NULL) {
3506       st->print(" = ");
3507       vmtarget->print_value_on(st);
3508     } else {
3509       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3510       st->print(".");
3511       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3512     }
3513   }
3514 }
3515 
3516 const char* InstanceKlass::internal_name() const {
3517   return external_name();
3518 }
3519 
3520 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3521                                              const char* module_name,
3522                                              const ClassFileStream* cfs) const {
3523   if (!log_is_enabled(Info, class, load)) {
3524     return;
3525   }
3526 
3527   ResourceMark rm;
3528   LogMessage(class, load) msg;
3529   stringStream info_stream;
3530 
3531   // Name and class hierarchy info
3532   info_stream.print("%s", external_name());
3533 
3534   // Source
3535   if (cfs != NULL) {
3536     if (cfs->source() != NULL) {
3537       if (module_name != NULL) {
3538         // When the boot loader created the stream, it didn't know the module name
3539         // yet. Let's format it now.
3540         if (cfs->from_boot_loader_modules_image()) {
3541           info_stream.print(" source: jrt:/%s", module_name);
3542         } else {
3543           info_stream.print(" source: %s", cfs->source());
3544         }
3545       } else {
3546         info_stream.print(" source: %s", cfs->source());
3547       }
3548     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3549       Thread* THREAD = Thread::current();
3550       Klass* caller =
3551             THREAD->is_Java_thread()
3552                 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3553                 : NULL;
3554       // caller can be NULL, for example, during a JVMTI VM_Init hook
3555       if (caller != NULL) {
3556         info_stream.print(" source: instance of %s", caller->external_name());
3557       } else {
3558         // source is unknown
3559       }
3560     } else {
3561       oop class_loader = loader_data->class_loader();
3562       info_stream.print(" source: %s", class_loader->klass()->external_name());
3563     }
3564   } else {
3565     assert(this->is_shared(), "must be");
3566     if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3567       info_stream.print(" source: shared objects file (top)");
3568     } else {
3569       info_stream.print(" source: shared objects file");
3570     }
3571   }
3572 
3573   msg.info("%s", info_stream.as_string());
3574 
3575   if (log_is_enabled(Debug, class, load)) {
3576     stringStream debug_stream;
3577 
3578     // Class hierarchy info
3579     debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3580                        p2i(this),  p2i(superklass()));
3581 
3582     // Interfaces
3583     if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3584       debug_stream.print(" interfaces:");
3585       int length = local_interfaces()->length();
3586       for (int i = 0; i < length; i++) {
3587         debug_stream.print(" " INTPTR_FORMAT,
3588                            p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3589       }
3590     }
3591 
3592     // Class loader
3593     debug_stream.print(" loader: [");
3594     loader_data->print_value_on(&debug_stream);
3595     debug_stream.print("]");
3596 
3597     // Classfile checksum
3598     if (cfs) {
3599       debug_stream.print(" bytes: %d checksum: %08x",
3600                          cfs->length(),
3601                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
3602                          cfs->length()));
3603     }
3604 
3605     msg.debug("%s", debug_stream.as_string());
3606   }
3607 }
3608 
3609 // Verification
3610 
3611 class VerifyFieldClosure: public BasicOopIterateClosure {
3612  protected:
3613   template <class T> void do_oop_work(T* p) {
3614     oop obj = RawAccess<>::oop_load(p);
3615     if (!oopDesc::is_oop_or_null(obj)) {
3616       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3617       Universe::print_on(tty);
3618       guarantee(false, "boom");
3619     }
3620   }
3621  public:
3622   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3623   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3624 };
3625 
3626 void InstanceKlass::verify_on(outputStream* st) {
3627 #ifndef PRODUCT
3628   // Avoid redundant verifies, this really should be in product.
3629   if (_verify_count == Universe::verify_count()) return;
3630   _verify_count = Universe::verify_count();
3631 #endif
3632 
3633   // Verify Klass
3634   Klass::verify_on(st);
3635 
3636   // Verify that klass is present in ClassLoaderData
3637   guarantee(class_loader_data()->contains_klass(this),
3638             "this class isn't found in class loader data");
3639 
3640   // Verify vtables
3641   if (is_linked()) {
3642     // $$$ This used to be done only for m/s collections.  Doing it
3643     // always seemed a valid generalization.  (DLD -- 6/00)
3644     vtable().verify(st);
3645   }
3646 
3647   // Verify first subklass
3648   if (subklass() != NULL) {
3649     guarantee(subklass()->is_klass(), "should be klass");
3650   }
3651 
3652   // Verify siblings
3653   Klass* super = this->super();
3654   Klass* sib = next_sibling();
3655   if (sib != NULL) {
3656     if (sib == this) {
3657       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3658     }
3659 
3660     guarantee(sib->is_klass(), "should be klass");
3661     guarantee(sib->super() == super, "siblings should have same superklass");
3662   }
3663 
3664   // Verify local interfaces
3665   if (local_interfaces()) {
3666     Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
3667     for (int j = 0; j < local_interfaces->length(); j++) {
3668       InstanceKlass* e = local_interfaces->at(j);
3669       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3670     }
3671   }
3672 
3673   // Verify transitive interfaces
3674   if (transitive_interfaces() != NULL) {
3675     Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
3676     for (int j = 0; j < transitive_interfaces->length(); j++) {
3677       InstanceKlass* e = transitive_interfaces->at(j);
3678       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3679     }
3680   }
3681 
3682   // Verify methods
3683   if (methods() != NULL) {
3684     Array<Method*>* methods = this->methods();
3685     for (int j = 0; j < methods->length(); j++) {
3686       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3687     }
3688     for (int j = 0; j < methods->length() - 1; j++) {
3689       Method* m1 = methods->at(j);
3690       Method* m2 = methods->at(j + 1);
3691       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3692     }
3693   }
3694 
3695   // Verify method ordering
3696   if (method_ordering() != NULL) {
3697     Array<int>* method_ordering = this->method_ordering();
3698     int length = method_ordering->length();
3699     if (JvmtiExport::can_maintain_original_method_order() ||
3700         ((UseSharedSpaces || Arguments::is_dumping_archive()) && length != 0)) {
3701       guarantee(length == methods()->length(), "invalid method ordering length");
3702       jlong sum = 0;
3703       for (int j = 0; j < length; j++) {
3704         int original_index = method_ordering->at(j);
3705         guarantee(original_index >= 0, "invalid method ordering index");
3706         guarantee(original_index < length, "invalid method ordering index");
3707         sum += original_index;
3708       }
3709       // Verify sum of indices 0,1,...,length-1
3710       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3711     } else {
3712       guarantee(length == 0, "invalid method ordering length");
3713     }
3714   }
3715 
3716   // Verify default methods
3717   if (default_methods() != NULL) {
3718     Array<Method*>* methods = this->default_methods();
3719     for (int j = 0; j < methods->length(); j++) {
3720       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3721     }
3722     for (int j = 0; j < methods->length() - 1; j++) {
3723       Method* m1 = methods->at(j);
3724       Method* m2 = methods->at(j + 1);
3725       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3726     }
3727   }
3728 
3729   // Verify JNI static field identifiers
3730   if (jni_ids() != NULL) {
3731     jni_ids()->verify(this);
3732   }
3733 
3734   // Verify other fields
3735   if (array_klasses() != NULL) {
3736     guarantee(array_klasses()->is_klass(), "should be klass");
3737   }
3738   if (constants() != NULL) {
3739     guarantee(constants()->is_constantPool(), "should be constant pool");
3740   }
3741   const Klass* anonymous_host = unsafe_anonymous_host();
3742   if (anonymous_host != NULL) {
3743     guarantee(anonymous_host->is_klass(), "should be klass");
3744   }
3745 }
3746 
3747 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3748   Klass::oop_verify_on(obj, st);
3749   VerifyFieldClosure blk;
3750   obj->oop_iterate(&blk);
3751 }
3752 
3753 
3754 // JNIid class for jfieldIDs only
3755 // Note to reviewers:
3756 // These JNI functions are just moved over to column 1 and not changed
3757 // in the compressed oops workspace.
3758 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3759   _holder = holder;
3760   _offset = offset;
3761   _next = next;
3762   debug_only(_is_static_field_id = false;)
3763 }
3764 
3765 
3766 JNIid* JNIid::find(int offset) {
3767   JNIid* current = this;
3768   while (current != NULL) {
3769     if (current->offset() == offset) return current;
3770     current = current->next();
3771   }
3772   return NULL;
3773 }
3774 
3775 void JNIid::deallocate(JNIid* current) {
3776   while (current != NULL) {
3777     JNIid* next = current->next();
3778     delete current;
3779     current = next;
3780   }
3781 }
3782 
3783 
3784 void JNIid::verify(Klass* holder) {
3785   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3786   int end_field_offset;
3787   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3788 
3789   JNIid* current = this;
3790   while (current != NULL) {
3791     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3792 #ifdef ASSERT
3793     int o = current->offset();
3794     if (current->is_static_field_id()) {
3795       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3796     }
3797 #endif
3798     current = current->next();
3799   }
3800 }
3801 
3802 void InstanceKlass::set_init_state(ClassState state) {
3803 #ifdef ASSERT
3804   bool good_state = is_shared() ? (_init_state <= state)
3805                                                : (_init_state < state);
3806   assert(good_state || state == allocated, "illegal state transition");
3807 #endif
3808   assert(_init_thread == NULL, "should be cleared before state change");
3809   _init_state = (u1)state;
3810 }
3811 
3812 #if INCLUDE_JVMTI
3813 
3814 // RedefineClasses() support for previous versions
3815 
3816 // Globally, there is at least one previous version of a class to walk
3817 // during class unloading, which is saved because old methods in the class
3818 // are still running.   Otherwise the previous version list is cleaned up.
3819 bool InstanceKlass::_has_previous_versions = false;
3820 
3821 // Returns true if there are previous versions of a class for class
3822 // unloading only. Also resets the flag to false. purge_previous_version
3823 // will set the flag to true if there are any left, i.e., if there's any
3824 // work to do for next time. This is to avoid the expensive code cache
3825 // walk in CLDG::clean_deallocate_lists().
3826 bool InstanceKlass::has_previous_versions_and_reset() {
3827   bool ret = _has_previous_versions;
3828   log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3829      ret ? "true" : "false");
3830   _has_previous_versions = false;
3831   return ret;
3832 }
3833 
3834 // Purge previous versions before adding new previous versions of the class and
3835 // during class unloading.
3836 void InstanceKlass::purge_previous_version_list() {
3837   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3838   assert(has_been_redefined(), "Should only be called for main class");
3839 
3840   // Quick exit.
3841   if (previous_versions() == NULL) {
3842     return;
3843   }
3844 
3845   // This klass has previous versions so see what we can cleanup
3846   // while it is safe to do so.
3847 
3848   int deleted_count = 0;    // leave debugging breadcrumbs
3849   int live_count = 0;
3850   ClassLoaderData* loader_data = class_loader_data();
3851   assert(loader_data != NULL, "should never be null");
3852 
3853   ResourceMark rm;
3854   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3855 
3856   // previous versions are linked together through the InstanceKlass
3857   InstanceKlass* pv_node = previous_versions();
3858   InstanceKlass* last = this;
3859   int version = 0;
3860 
3861   // check the previous versions list
3862   for (; pv_node != NULL; ) {
3863 
3864     ConstantPool* pvcp = pv_node->constants();
3865     assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3866 
3867     if (!pvcp->on_stack()) {
3868       // If the constant pool isn't on stack, none of the methods
3869       // are executing.  Unlink this previous_version.
3870       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3871       // so will be deallocated during the next phase of class unloading.
3872       log_trace(redefine, class, iklass, purge)
3873         ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3874       // For debugging purposes.
3875       pv_node->set_is_scratch_class();
3876       // Unlink from previous version list.
3877       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3878       InstanceKlass* next = pv_node->previous_versions();
3879       pv_node->link_previous_versions(NULL);   // point next to NULL
3880       last->link_previous_versions(next);
3881       // Add to the deallocate list after unlinking
3882       loader_data->add_to_deallocate_list(pv_node);
3883       pv_node = next;
3884       deleted_count++;
3885       version++;
3886       continue;
3887     } else {
3888       log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3889       assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3890       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3891       live_count++;
3892       // found a previous version for next time we do class unloading
3893       _has_previous_versions = true;
3894     }
3895 
3896     // At least one method is live in this previous version.
3897     // Reset dead EMCP methods not to get breakpoints.
3898     // All methods are deallocated when all of the methods for this class are no
3899     // longer running.
3900     Array<Method*>* method_refs = pv_node->methods();
3901     if (method_refs != NULL) {
3902       log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3903       for (int j = 0; j < method_refs->length(); j++) {
3904         Method* method = method_refs->at(j);
3905 
3906         if (!method->on_stack()) {
3907           // no breakpoints for non-running methods
3908           if (method->is_running_emcp()) {
3909             method->set_running_emcp(false);
3910           }
3911         } else {
3912           assert (method->is_obsolete() || method->is_running_emcp(),
3913                   "emcp method cannot run after emcp bit is cleared");
3914           log_trace(redefine, class, iklass, purge)
3915             ("purge: %s(%s): prev method @%d in version @%d is alive",
3916              method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3917         }
3918       }
3919     }
3920     // next previous version
3921     last = pv_node;
3922     pv_node = pv_node->previous_versions();
3923     version++;
3924   }
3925   log_trace(redefine, class, iklass, purge)
3926     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3927 }
3928 
3929 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3930                                                 int emcp_method_count) {
3931   int obsolete_method_count = old_methods->length() - emcp_method_count;
3932 
3933   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3934       _previous_versions != NULL) {
3935     // We have a mix of obsolete and EMCP methods so we have to
3936     // clear out any matching EMCP method entries the hard way.
3937     int local_count = 0;
3938     for (int i = 0; i < old_methods->length(); i++) {
3939       Method* old_method = old_methods->at(i);
3940       if (old_method->is_obsolete()) {
3941         // only obsolete methods are interesting
3942         Symbol* m_name = old_method->name();
3943         Symbol* m_signature = old_method->signature();
3944 
3945         // previous versions are linked together through the InstanceKlass
3946         int j = 0;
3947         for (InstanceKlass* prev_version = _previous_versions;
3948              prev_version != NULL;
3949              prev_version = prev_version->previous_versions(), j++) {
3950 
3951           Array<Method*>* method_refs = prev_version->methods();
3952           for (int k = 0; k < method_refs->length(); k++) {
3953             Method* method = method_refs->at(k);
3954 
3955             if (!method->is_obsolete() &&
3956                 method->name() == m_name &&
3957                 method->signature() == m_signature) {
3958               // The current RedefineClasses() call has made all EMCP
3959               // versions of this method obsolete so mark it as obsolete
3960               log_trace(redefine, class, iklass, add)
3961                 ("%s(%s): flush obsolete method @%d in version @%d",
3962                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
3963 
3964               method->set_is_obsolete();
3965               break;
3966             }
3967           }
3968 
3969           // The previous loop may not find a matching EMCP method, but
3970           // that doesn't mean that we can optimize and not go any
3971           // further back in the PreviousVersion generations. The EMCP
3972           // method for this generation could have already been made obsolete,
3973           // but there still may be an older EMCP method that has not
3974           // been made obsolete.
3975         }
3976 
3977         if (++local_count >= obsolete_method_count) {
3978           // no more obsolete methods so bail out now
3979           break;
3980         }
3981       }
3982     }
3983   }
3984 }
3985 
3986 // Save the scratch_class as the previous version if any of the methods are running.
3987 // The previous_versions are used to set breakpoints in EMCP methods and they are
3988 // also used to clean MethodData links to redefined methods that are no longer running.
3989 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3990                                          int emcp_method_count) {
3991   assert(Thread::current()->is_VM_thread(),
3992          "only VMThread can add previous versions");
3993 
3994   ResourceMark rm;
3995   log_trace(redefine, class, iklass, add)
3996     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3997 
3998   // Clean out old previous versions for this class
3999   purge_previous_version_list();
4000 
4001   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
4002   // a previous redefinition may be made obsolete by this redefinition.
4003   Array<Method*>* old_methods = scratch_class->methods();
4004   mark_newly_obsolete_methods(old_methods, emcp_method_count);
4005 
4006   // If the constant pool for this previous version of the class
4007   // is not marked as being on the stack, then none of the methods
4008   // in this previous version of the class are on the stack so
4009   // we don't need to add this as a previous version.
4010   ConstantPool* cp_ref = scratch_class->constants();
4011   if (!cp_ref->on_stack()) {
4012     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4013     // For debugging purposes.
4014     scratch_class->set_is_scratch_class();
4015     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4016     return;
4017   }
4018 
4019   if (emcp_method_count != 0) {
4020     // At least one method is still running, check for EMCP methods
4021     for (int i = 0; i < old_methods->length(); i++) {
4022       Method* old_method = old_methods->at(i);
4023       if (!old_method->is_obsolete() && old_method->on_stack()) {
4024         // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
4025         // we can add breakpoints for it.
4026 
4027         // We set the method->on_stack bit during safepoints for class redefinition
4028         // and use this bit to set the is_running_emcp bit.
4029         // After the safepoint, the on_stack bit is cleared and the running emcp
4030         // method may exit.   If so, we would set a breakpoint in a method that
4031         // is never reached, but this won't be noticeable to the programmer.
4032         old_method->set_running_emcp(true);
4033         log_trace(redefine, class, iklass, add)
4034           ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
4035       } else if (!old_method->is_obsolete()) {
4036         log_trace(redefine, class, iklass, add)
4037           ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
4038       }
4039     }
4040   }
4041 
4042   // Add previous version if any methods are still running.
4043   // Set has_previous_version flag for processing during class unloading.
4044   _has_previous_versions = true;
4045   log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4046   assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
4047   scratch_class->link_previous_versions(previous_versions());
4048   link_previous_versions(scratch_class);
4049 } // end add_previous_version()
4050 
4051 #endif // INCLUDE_JVMTI
4052 
4053 Method* InstanceKlass::method_with_idnum(int idnum) {
4054   Method* m = NULL;
4055   if (idnum < methods()->length()) {
4056     m = methods()->at(idnum);
4057   }
4058   if (m == NULL || m->method_idnum() != idnum) {
4059     for (int index = 0; index < methods()->length(); ++index) {
4060       m = methods()->at(index);
4061       if (m->method_idnum() == idnum) {
4062         return m;
4063       }
4064     }
4065     // None found, return null for the caller to handle.
4066     return NULL;
4067   }
4068   return m;
4069 }
4070 
4071 
4072 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4073   if (idnum >= methods()->length()) {
4074     return NULL;
4075   }
4076   Method* m = methods()->at(idnum);
4077   if (m != NULL && m->orig_method_idnum() == idnum) {
4078     return m;
4079   }
4080   // Obsolete method idnum does not match the original idnum
4081   for (int index = 0; index < methods()->length(); ++index) {
4082     m = methods()->at(index);
4083     if (m->orig_method_idnum() == idnum) {
4084       return m;
4085     }
4086   }
4087   // None found, return null for the caller to handle.
4088   return NULL;
4089 }
4090 
4091 
4092 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4093   InstanceKlass* holder = get_klass_version(version);
4094   if (holder == NULL) {
4095     return NULL; // The version of klass is gone, no method is found
4096   }
4097   Method* method = holder->method_with_orig_idnum(idnum);
4098   return method;
4099 }
4100 
4101 #if INCLUDE_JVMTI
4102 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4103   return _cached_class_file;
4104 }
4105 
4106 jint InstanceKlass::get_cached_class_file_len() {
4107   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4108 }
4109 
4110 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4111   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4112 }
4113 #endif