1 /*
   2  * Copyright (c) 1997, 2023, 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 #ifndef SHARE_OOPS_INSTANCEKLASS_HPP
  26 #define SHARE_OOPS_INSTANCEKLASS_HPP
  27 
  28 #include "memory/referenceType.hpp"
  29 #include "oops/annotations.hpp"
  30 #include "oops/constMethod.hpp"
  31 #include "oops/fieldInfo.hpp"
  32 #include "oops/instanceKlassFlags.hpp"
  33 #include "oops/instanceOop.hpp"
  34 #include "runtime/handles.hpp"
  35 #include "runtime/javaThread.hpp"
  36 #include "utilities/accessFlags.hpp"
  37 #include "utilities/align.hpp"
  38 #include "utilities/growableArray.hpp"
  39 #include "utilities/macros.hpp"
  40 #if INCLUDE_JFR
  41 #include "jfr/support/jfrKlassExtension.hpp"
  42 #endif
  43 
  44 class ConstantPool;
  45 class DeoptimizationScope;
  46 class klassItable;
  47 class Monitor;
  48 class RecordComponent;
  49 
  50 // An InstanceKlass is the VM level representation of a Java class.
  51 // It contains all information needed for at class at execution runtime.
  52 
  53 //  InstanceKlass embedded field layout (after declared fields):
  54 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  55 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  56 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  57 //      indicating where oops are located in instances of this klass.
  58 //    [EMBEDDED implementor of the interface] only exist for interface
  59 
  60 
  61 // forward declaration for class -- see below for definition
  62 #if INCLUDE_JVMTI
  63 class BreakpointInfo;
  64 #endif
  65 class ClassFileParser;
  66 class ClassFileStream;
  67 class KlassDepChange;
  68 class DependencyContext;
  69 class fieldDescriptor;
  70 class jniIdMapBase;
  71 class JNIid;
  72 class JvmtiCachedClassFieldMap;
  73 class nmethodBucket;
  74 class OopMapCache;
  75 class InterpreterOopMap;
  76 class PackageEntry;
  77 class ModuleEntry;
  78 class KlassTrainingData;
  79 
  80 // This is used in iterators below.
  81 class FieldClosure: public StackObj {
  82 public:
  83   virtual void do_field(fieldDescriptor* fd) = 0;
  84 };
  85 
  86 // Print fields.
  87 // If "obj" argument to constructor is null, prints static fields, otherwise prints non-static fields.
  88 class FieldPrinter: public FieldClosure {
  89    oop _obj;
  90    outputStream* _st;
  91  public:
  92    FieldPrinter(outputStream* st, oop obj = nullptr) : _obj(obj), _st(st) {}
  93    void do_field(fieldDescriptor* fd);
  94 };
  95 
  96 // Describes where oops are located in instances of this klass.
  97 class OopMapBlock {
  98  public:
  99   // Byte offset of the first oop mapped by this block.
 100   int offset() const          { return _offset; }
 101   void set_offset(int offset) { _offset = offset; }
 102 
 103   // Number of oops in this block.
 104   uint count() const         { return _count; }
 105   void set_count(uint count) { _count = count; }
 106 
 107   void increment_count(int diff) { _count += diff; }
 108 
 109   int offset_span() const { return _count * heapOopSize; }
 110 
 111   int end_offset() const {
 112     return offset() + offset_span();
 113   }
 114 
 115   bool is_contiguous(int another_offset) const {
 116     return another_offset == end_offset();
 117   }
 118 
 119   // sizeof(OopMapBlock) in words.
 120   static int size_in_words() {
 121     return align_up((int)sizeof(OopMapBlock), wordSize) >>
 122       LogBytesPerWord;
 123   }
 124 
 125   static int compare_offset(const OopMapBlock* a, const OopMapBlock* b) {
 126     return a->offset() - b->offset();
 127   }
 128 
 129  private:
 130   int  _offset;
 131   uint _count;
 132 };
 133 
 134 struct JvmtiCachedClassFileData;
 135 
 136 class InstanceKlass: public Klass {
 137   friend class VMStructs;
 138   friend class JVMCIVMStructs;
 139   friend class ClassFileParser;
 140   friend class CompileReplay;
 141 
 142  public:
 143   static const KlassKind Kind = InstanceKlassKind;
 144 
 145  protected:
 146   InstanceKlass(const ClassFileParser& parser, KlassKind kind = Kind, ReferenceType reference_type = REF_NONE);
 147 
 148  public:
 149   InstanceKlass();
 150 
 151   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 152   // of the class loading & initialization procedure, and the use of the states.
 153   enum ClassState : u1 {
 154     allocated,                          // allocated (but not yet linked)
 155     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 156     being_linked,                       // currently running verifier and rewriter
 157     linked,                             // successfully linked/verified (but not initialized yet)
 158     being_initialized,                  // currently running class initializer
 159     fully_initialized,                  // initialized (successful final state)
 160     initialization_error                // error happened during initialization
 161   };
 162 
 163  private:
 164   static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);
 165 
 166  protected:
 167   // If you add a new field that points to any metaspace object, you
 168   // must add this field to InstanceKlass::metaspace_pointers_do().
 169 
 170   // Annotations for this class
 171   Annotations*    _annotations;
 172   // Package this class is defined in
 173   PackageEntry*   _package_entry;
 174   // Array classes holding elements of this class.
 175   ObjArrayKlass* volatile _array_klasses;
 176   // Constant pool for this class.
 177   ConstantPool* _constants;
 178   // The InnerClasses attribute and EnclosingMethod attribute. The
 179   // _inner_classes is an array of shorts. If the class has InnerClasses
 180   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 181   // [inner_class_info_index, outer_class_info_index,
 182   // inner_name_index, inner_class_access_flags] for the InnerClasses
 183   // attribute. If the EnclosingMethod attribute exists, it occupies the
 184   // last two shorts [class_index, method_index] of the array. If only
 185   // the InnerClasses attribute exists, the _inner_classes array length is
 186   // number_of_inner_classes * 4. If the class has both InnerClasses
 187   // and EnclosingMethod attributes the _inner_classes array length is
 188   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 189   Array<jushort>* _inner_classes;
 190 
 191   // The NestMembers attribute. An array of shorts, where each is a
 192   // class info index for the class that is a nest member. This data
 193   // has not been validated.
 194   Array<jushort>* _nest_members;
 195 
 196   // Resolved nest-host klass: either true nest-host or self if we are not
 197   // nested, or an error occurred resolving or validating the nominated
 198   // nest-host. Can also be set directly by JDK API's that establish nest
 199   // relationships.
 200   // By always being set it makes nest-member access checks simpler.
 201   InstanceKlass* _nest_host;
 202 
 203   // The PermittedSubclasses attribute. An array of shorts, where each is a
 204   // class info index for the class that is a permitted subclass.
 205   Array<jushort>* _permitted_subclasses;
 206 
 207   // The contents of the Record attribute.
 208   Array<RecordComponent*>* _record_components;
 209 
 210   // the source debug extension for this klass, null if not specified.
 211   // Specified as UTF-8 string without terminating zero byte in the classfile,
 212   // it is stored in the instanceklass as a null-terminated UTF-8 string
 213   const char*     _source_debug_extension;
 214 
 215   // Number of heapOopSize words used by non-static fields in this klass
 216   // (including inherited fields but after header_size()).
 217   int             _nonstatic_field_size;
 218   int             _static_field_size;       // number words used by static fields (oop and non-oop) in this klass
 219   int             _nonstatic_oop_map_size;  // size in words of nonstatic oop map blocks
 220   int             _itable_len;              // length of Java itable (in words)
 221 
 222   // The NestHost attribute. The class info index for the class
 223   // that is the nest-host of this class. This data has not been validated.
 224   u2              _nest_host_index;
 225   u2              _this_class_index;        // constant pool entry
 226   u2              _static_oop_field_count;  // number of static oop fields in this klass
 227 
 228   volatile u2     _idnum_allocated_count;   // JNI/JVMTI: increments with the addition of methods, old ids don't change
 229 
 230   volatile ClassState _init_state;          // state of class
 231 
 232   u1              _reference_type;          // reference type
 233 
 234   // State is set either at parse time or while executing, atomically to not disturb other state
 235   InstanceKlassFlags _misc_flags;
 236 
 237   Monitor*             _init_monitor;       // mutual exclusion to _init_state and _init_thread.
 238   JavaThread* volatile _init_thread;        // Pointer to current thread doing initialization (to handle recursive initialization)
 239   KlassTrainingData*   _training_data;      // Null except in training mode.
 240 
 241   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 242   JNIid*          _jni_ids;              // First JNI identifier for static fields in this class
 243   jmethodID*      volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or null if none
 244   nmethodBucket*  volatile _dep_context;          // packed DependencyContext structure
 245   uint64_t        volatile _dep_context_last_cleaned;
 246   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 247 #if INCLUDE_JVMTI
 248   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 249   // Linked instanceKlasses of previous versions
 250   InstanceKlass* _previous_versions;
 251   // JVMTI fields can be moved to their own structure - see 6315920
 252   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 253   JvmtiCachedClassFileData* _cached_class_file;
 254 #endif
 255 
 256 #if INCLUDE_JVMTI
 257   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 258 #endif
 259 
 260   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 261   NOT_PRODUCT(volatile int _shared_class_load_count;) // ensure a shared class is loaded only once
 262 
 263   // Method array.
 264   Array<Method*>* _methods;
 265   // Default Method Array, concrete methods inherited from interfaces
 266   Array<Method*>* _default_methods;
 267   // Interfaces (InstanceKlass*s) this class declares locally to implement.
 268   Array<InstanceKlass*>* _local_interfaces;
 269   // Interfaces (InstanceKlass*s) this class implements transitively.
 270   Array<InstanceKlass*>* _transitive_interfaces;
 271   // Int array containing the original order of method in the class file (for JVMTI).
 272   Array<int>*     _method_ordering;
 273   // Int array containing the vtable_indices for default_methods
 274   // offset matches _default_methods offset
 275   Array<int>*     _default_vtable_indices;
 276 
 277   // Fields information is stored in an UNSIGNED5 encoded stream (see fieldInfo.hpp)
 278   Array<u1>*          _fieldinfo_stream;
 279   Array<FieldStatus>* _fields_status;
 280 
 281   // embedded Java vtable follows here
 282   // embedded Java itables follows here
 283   // embedded static fields follows here
 284   // embedded nonstatic oop-map blocks follows here
 285   // embedded implementor of this interface follows here
 286   //   The embedded implementor only exists if the current klass is an
 287   //   interface. The possible values of the implementor fall into following
 288   //   three cases:
 289   //     null: no implementor.
 290   //     A Klass* that's not itself: one implementor.
 291   //     Itself: more than one implementors.
 292   //
 293 
 294   friend class SystemDictionary;
 295 
 296   static bool _disable_method_binary_search;
 297 
 298   // Controls finalizer registration
 299   static bool _finalization_enabled;
 300 
 301  public:
 302 
 303   // Queries finalization state
 304   static bool is_finalization_enabled() { return _finalization_enabled; }
 305 
 306   // Sets finalization state
 307   static void set_finalization_enabled(bool val) { _finalization_enabled = val; }
 308 
 309   // The three BUILTIN class loader types
 310   bool is_shared_boot_class() const { return _misc_flags.is_shared_boot_class(); }
 311   bool is_shared_platform_class() const { return _misc_flags.is_shared_platform_class(); }
 312   bool is_shared_app_class() const {  return _misc_flags.is_shared_app_class(); }
 313   // The UNREGISTERED class loader type
 314   bool is_shared_unregistered_class() const { return _misc_flags.is_shared_unregistered_class(); }
 315 
 316   // Check if the class can be shared in CDS
 317   bool is_shareable() const;
 318 
 319   bool shared_loading_failed() const { return _misc_flags.shared_loading_failed(); }
 320 
 321   void set_shared_loading_failed() { _misc_flags.set_shared_loading_failed(true); }
 322 
 323 #if INCLUDE_CDS
 324   int  shared_class_loader_type() const;
 325   void set_shared_class_loader_type(s2 loader_type) { _misc_flags.set_shared_class_loader_type(loader_type); }
 326   void assign_class_loader_type() { _misc_flags.assign_class_loader_type(_class_loader_data); }
 327 #endif
 328 
 329   bool has_nonstatic_fields() const        { return _misc_flags.has_nonstatic_fields(); }
 330   void set_has_nonstatic_fields(bool b)    { _misc_flags.set_has_nonstatic_fields(b); }
 331 
 332   bool has_localvariable_table() const     { return _misc_flags.has_localvariable_table(); }
 333   void set_has_localvariable_table(bool b) { _misc_flags.set_has_localvariable_table(b); }
 334 
 335   // field sizes
 336   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 337   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 338 
 339   int static_field_size() const            { return _static_field_size; }
 340   void set_static_field_size(int size)     { _static_field_size = size; }
 341 
 342   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 343   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 344 
 345   // Java itable
 346   int  itable_length() const               { return _itable_len; }
 347   void set_itable_length(int len)          { _itable_len = len; }
 348 
 349   // array klasses
 350   ObjArrayKlass* array_klasses() const     { return _array_klasses; }
 351   inline ObjArrayKlass* array_klasses_acquire() const; // load with acquire semantics
 352   inline void release_set_array_klasses(ObjArrayKlass* k); // store with release semantics
 353   void set_array_klasses(ObjArrayKlass* k) { _array_klasses = k; }
 354 
 355   // methods
 356   Array<Method*>* methods() const          { return _methods; }
 357   void set_methods(Array<Method*>* a)      { _methods = a; }
 358   Method* method_with_idnum(int idnum);
 359   Method* method_with_orig_idnum(int idnum);
 360   Method* method_with_orig_idnum(int idnum, int version);
 361 
 362   // method ordering
 363   Array<int>* method_ordering() const     { return _method_ordering; }
 364   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 365   void copy_method_ordering(const intArray* m, TRAPS);
 366 
 367   // default_methods
 368   Array<Method*>* default_methods() const  { return _default_methods; }
 369   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 370 
 371   // default method vtable_indices
 372   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 373   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 374   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 375 
 376   // interfaces
 377   Array<InstanceKlass*>* local_interfaces() const          { return _local_interfaces; }
 378   void set_local_interfaces(Array<InstanceKlass*>* a)      {
 379     guarantee(_local_interfaces == nullptr || a == nullptr, "Just checking");
 380     _local_interfaces = a; }
 381 
 382   Array<InstanceKlass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 383   void set_transitive_interfaces(Array<InstanceKlass*>* a) {
 384     guarantee(_transitive_interfaces == nullptr || a == nullptr, "Just checking");
 385     _transitive_interfaces = a;
 386   }
 387 
 388  private:
 389   friend class fieldDescriptor;
 390   FieldInfo field(int index) const;
 391 
 392  public:
 393   int     field_offset      (int index) const { return field(index).offset(); }
 394   int     field_access_flags(int index) const { return field(index).access_flags().as_int(); }
 395   FieldInfo::FieldFlags field_flags(int index) const { return field(index).field_flags(); }
 396   FieldStatus field_status(int index)   const { return fields_status()->at(index); }
 397   inline Symbol* field_name        (int index) const;
 398   inline Symbol* field_signature   (int index) const;
 399 
 400   // Number of Java declared fields
 401   int java_fields_count() const;
 402   int total_fields_count() const;
 403 
 404   Array<u1>* fieldinfo_stream() const { return _fieldinfo_stream; }
 405   void set_fieldinfo_stream(Array<u1>* fis) { _fieldinfo_stream = fis; }
 406 
 407   Array<FieldStatus>* fields_status() const {return _fields_status; }
 408   void set_fields_status(Array<FieldStatus>* array) { _fields_status = array; }
 409 
 410   // inner classes
 411   Array<u2>* inner_classes() const       { return _inner_classes; }
 412   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 413 
 414   // nest members
 415   Array<u2>* nest_members() const     { return _nest_members; }
 416   void set_nest_members(Array<u2>* m) { _nest_members = m; }
 417 
 418   // nest-host index
 419   jushort nest_host_index() const { return _nest_host_index; }
 420   void set_nest_host_index(u2 i)  { _nest_host_index = i; }
 421   // dynamic nest member support
 422   void set_nest_host(InstanceKlass* host);
 423 
 424   // record components
 425   Array<RecordComponent*>* record_components() const { return _record_components; }
 426   void set_record_components(Array<RecordComponent*>* record_components) {
 427     _record_components = record_components;
 428   }
 429   bool is_record() const;
 430 
 431   // permitted subclasses
 432   Array<u2>* permitted_subclasses() const     { return _permitted_subclasses; }
 433   void set_permitted_subclasses(Array<u2>* s) { _permitted_subclasses = s; }
 434 
 435 private:
 436   // Called to verify that k is a member of this nest - does not look at k's nest-host,
 437   // nor does it resolve any CP entries or load any classes.
 438   bool has_nest_member(JavaThread* current, InstanceKlass* k) const;
 439 
 440 public:
 441   // Call this only if you know that the nest host has been initialized.
 442   InstanceKlass* nest_host_not_null() {
 443     assert(_nest_host != nullptr, "must be");
 444     return _nest_host;
 445   }
 446   // Used to construct informative IllegalAccessError messages at a higher level,
 447   // if there was an issue resolving or validating the nest host.
 448   // Returns null if there was no error.
 449   const char* nest_host_error();
 450   // Returns nest-host class, resolving and validating it if needed.
 451   // Returns null if resolution is not possible from the calling context.
 452   InstanceKlass* nest_host(TRAPS);
 453   // Check if this klass is a nestmate of k - resolves this nest-host and k's
 454   bool has_nestmate_access_to(InstanceKlass* k, TRAPS);
 455 
 456   // Called to verify that k is a permitted subclass of this class
 457   bool has_as_permitted_subclass(const InstanceKlass* k) const;
 458 
 459   enum InnerClassAttributeOffset {
 460     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 461     inner_class_inner_class_info_offset = 0,
 462     inner_class_outer_class_info_offset = 1,
 463     inner_class_inner_name_offset = 2,
 464     inner_class_access_flags_offset = 3,
 465     inner_class_next_offset = 4
 466   };
 467 
 468   enum EnclosingMethodAttributeOffset {
 469     enclosing_method_class_index_offset = 0,
 470     enclosing_method_method_index_offset = 1,
 471     enclosing_method_attribute_size = 2
 472   };
 473 
 474   // package
 475   PackageEntry* package() const     { return _package_entry; }
 476   ModuleEntry* module() const;
 477   bool in_unnamed_package() const   { return (_package_entry == nullptr); }
 478   void set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS);
 479   // If the package for the InstanceKlass is in the boot loader's package entry
 480   // table then sets the classpath_index field so that
 481   // get_system_package() will know to return a non-null value for the
 482   // package's location.  And, so that the package will be added to the list of
 483   // packages returned by get_system_packages().
 484   // For packages whose classes are loaded from the boot loader class path, the
 485   // classpath_index indicates which entry on the boot loader class path.
 486   void set_classpath_index(s2 path_index);
 487   bool is_same_class_package(const Klass* class2) const;
 488   bool is_same_class_package(oop other_class_loader, const Symbol* other_class_name) const;
 489 
 490   // find an enclosing class
 491   InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const;
 492 
 493   // Find InnerClasses attribute and return outer_class_info_index & inner_name_index.
 494   bool find_inner_classes_attr(int* ooff, int* noff, TRAPS) const;
 495 
 496  private:
 497   // Check prohibited package ("java/" only loadable by boot or platform loaders)
 498   static void check_prohibited_package(Symbol* class_name,
 499                                        ClassLoaderData* loader_data,
 500                                        TRAPS);
 501 
 502   JavaThread* init_thread()  { return Atomic::load(&_init_thread); }
 503   // We can safely access the name as long as we hold the _init_monitor.
 504   const char* init_thread_name() {
 505     assert(_init_monitor->owned_by_self(), "Must hold _init_monitor here");
 506     return init_thread()->name_raw();
 507   }
 508 
 509  public:
 510   // initialization state
 511   bool is_loaded() const                   { return init_state() >= loaded; }
 512   bool is_linked() const                   { return init_state() >= linked; }
 513   bool is_being_linked() const             { return init_state() == being_linked; }
 514   bool is_initialized() const              { return init_state() == fully_initialized; }
 515   bool is_not_initialized() const          { return init_state() <  being_initialized; }
 516   bool is_being_initialized() const        { return init_state() == being_initialized; }
 517   bool is_in_error_state() const           { return init_state() == initialization_error; }
 518   bool is_init_thread(JavaThread *thread)  { return thread == init_thread(); }
 519   ClassState  init_state() const           { return Atomic::load(&_init_state); }
 520   const char* init_state_name() const;
 521   bool is_rewritten() const                { return _misc_flags.rewritten(); }
 522 
 523   KlassTrainingData* training_data_or_null() const {
 524     // there is a lot of concurrent state around classes, so let's use atomics
 525     return Atomic::load_acquire(&_training_data);
 526   }
 527   bool init_training_data(KlassTrainingData* tdata) {
 528     return (_training_data == tdata ||
 529             Atomic::replace_if_null(&_training_data, tdata));
 530   }
 531   KlassTrainingData* training_data() const {
 532     KlassTrainingData* tdata = training_data_or_null();
 533     assert(tdata != nullptr, "call alloc_training_data first");
 534     return tdata;
 535   }
 536   // return existing if there is one, else allocate
 537   KlassTrainingData* alloc_training_data(TRAPS);
 538 
 539   static const char* state2name(ClassState state);
 540 
 541   class LockLinkState : public StackObj {
 542     InstanceKlass* _ik;
 543     JavaThread*    _current;
 544    public:
 545     LockLinkState(InstanceKlass* ik, JavaThread* current) : _ik(ik), _current(current) {
 546       ik->check_link_state_and_wait(current);
 547     }
 548     ~LockLinkState() {
 549       if (!_ik->is_linked()) {
 550         // Reset to loaded if linking failed.
 551         _ik->set_initialization_state_and_notify(loaded, _current);
 552       }
 553     }
 554   };
 555 
 556   // is this a sealed class
 557   bool is_sealed() const;
 558 
 559   // defineClass specified verification
 560   bool should_verify_class() const         { return _misc_flags.should_verify_class(); }
 561   void set_should_verify_class(bool value) { _misc_flags.set_should_verify_class(value); }
 562 
 563   // marking
 564   bool is_marked_dependent() const         { return _misc_flags.is_marked_dependent(); }
 565   void set_is_marked_dependent(bool value) { _misc_flags.set_is_marked_dependent(value); }
 566 
 567   // initialization (virtuals from Klass)
 568   bool should_be_initialized() const;  // means that initialize should be called
 569   void initialize_from_cds(TRAPS);
 570   void initialize(TRAPS);
 571   void link_class(TRAPS);
 572   bool link_class_or_fail(TRAPS); // returns false on failure
 573   void rewrite_class(TRAPS);
 574   void link_methods(TRAPS);
 575   Method* class_initializer() const;
 576 
 577   // reference type
 578   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 579 
 580   // this class cp index
 581   u2 this_class_index() const             { return _this_class_index; }
 582   void set_this_class_index(u2 index)     { _this_class_index = index; }
 583 
 584   static ByteSize reference_type_offset() { return byte_offset_of(InstanceKlass, _reference_type); }
 585 
 586   // find local field, returns true if found
 587   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 588   // find field in direct superinterfaces, returns the interface in which the field is defined
 589   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 590   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 591   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 592   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 593   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 594 
 595   // find a non-static or static field given its offset within the class.
 596   bool contains_field_offset(int offset);
 597 
 598   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 599   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 600 
 601  private:
 602   inline static int quick_search(const Array<Method*>* methods, const Symbol* name);
 603 
 604  public:
 605   static void disable_method_binary_search() {
 606     _disable_method_binary_search = true;
 607   }
 608 
 609   // find a local method (returns null if not found)
 610   Method* find_method(const Symbol* name, const Symbol* signature) const;
 611   static Method* find_method(const Array<Method*>* methods,
 612                              const Symbol* name,
 613                              const Symbol* signature);
 614 
 615   // find a local method, but skip static methods
 616   Method* find_instance_method(const Symbol* name, const Symbol* signature,
 617                                PrivateLookupMode private_mode) const;
 618   static Method* find_instance_method(const Array<Method*>* methods,
 619                                       const Symbol* name,
 620                                       const Symbol* signature,
 621                                       PrivateLookupMode private_mode);
 622 
 623   // find a local method (returns null if not found)
 624   Method* find_local_method(const Symbol* name,
 625                             const Symbol* signature,
 626                             OverpassLookupMode overpass_mode,
 627                             StaticLookupMode static_mode,
 628                             PrivateLookupMode private_mode) const;
 629 
 630   // find a local method from given methods array (returns null if not found)
 631   static Method* find_local_method(const Array<Method*>* methods,
 632                                    const Symbol* name,
 633                                    const Symbol* signature,
 634                                    OverpassLookupMode overpass_mode,
 635                                    StaticLookupMode static_mode,
 636                                    PrivateLookupMode private_mode);
 637 
 638   // find a local method index in methods or default_methods (returns -1 if not found)
 639   static int find_method_index(const Array<Method*>* methods,
 640                                const Symbol* name,
 641                                const Symbol* signature,
 642                                OverpassLookupMode overpass_mode,
 643                                StaticLookupMode static_mode,
 644                                PrivateLookupMode private_mode);
 645 
 646   // lookup operation (returns null if not found)
 647   Method* uncached_lookup_method(const Symbol* name,
 648                                  const Symbol* signature,
 649                                  OverpassLookupMode overpass_mode,
 650                                  PrivateLookupMode private_mode = PrivateLookupMode::find) const;
 651 
 652   // lookup a method in all the interfaces that this class implements
 653   // (returns null if not found)
 654   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, DefaultsLookupMode defaults_mode) const;
 655 
 656   // lookup a method in local defaults then in all interfaces
 657   // (returns null if not found)
 658   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 659 
 660   // Find method indices by name.  If a method with the specified name is
 661   // found the index to the first method is returned, and 'end' is filled in
 662   // with the index of first non-name-matching method.  If no method is found
 663   // -1 is returned.
 664   int find_method_by_name(const Symbol* name, int* end) const;
 665   static int find_method_by_name(const Array<Method*>* methods,
 666                                  const Symbol* name, int* end);
 667 
 668   // constant pool
 669   ConstantPool* constants() const        { return _constants; }
 670   void set_constants(ConstantPool* c)    { _constants = c; }
 671 
 672   // protection domain
 673   oop protection_domain() const;
 674 
 675   // signers
 676   objArrayOop signers() const;
 677 
 678   bool is_contended() const                { return _misc_flags.is_contended(); }
 679   void set_is_contended(bool value)        { _misc_flags.set_is_contended(value); }
 680 
 681   // source file name
 682   Symbol* source_file_name() const;
 683   u2 source_file_name_index() const;
 684   void set_source_file_name_index(u2 sourcefile_index);
 685 
 686   // minor and major version numbers of class file
 687   u2 minor_version() const;
 688   void set_minor_version(u2 minor_version);
 689   u2 major_version() const;
 690   void set_major_version(u2 major_version);
 691 
 692   // source debug extension
 693   const char* source_debug_extension() const { return _source_debug_extension; }
 694   void set_source_debug_extension(const char* array, int length);
 695 
 696   // nonstatic oop-map blocks
 697   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 698     return oop_map_count * OopMapBlock::size_in_words();
 699   }
 700   unsigned int nonstatic_oop_map_count() const {
 701     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 702   }
 703   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 704   void set_nonstatic_oop_map_size(int words) {
 705     _nonstatic_oop_map_size = words;
 706   }
 707 
 708   bool has_contended_annotations() const { return _misc_flags.has_contended_annotations(); }
 709   void set_has_contended_annotations(bool value)  { _misc_flags.set_has_contended_annotations(value); }
 710 
 711 #if INCLUDE_JVMTI
 712   // Redefinition locking.  Class can only be redefined by one thread at a time.
 713   // The flag is in access_flags so that it can be set and reset using atomic
 714   // operations, and not be reset by other misc_flag settings.
 715   bool is_being_redefined() const          { return _misc_flags.is_being_redefined(); }
 716   void set_is_being_redefined(bool value)  { _misc_flags.set_is_being_redefined(value); }
 717 
 718   // RedefineClasses() support for previous versions:
 719   void add_previous_version(InstanceKlass* ik, int emcp_method_count);
 720   void purge_previous_version_list();
 721 
 722   InstanceKlass* previous_versions() const { return _previous_versions; }
 723 #else
 724   InstanceKlass* previous_versions() const { return nullptr; }
 725 #endif
 726 
 727   InstanceKlass* get_klass_version(int version);
 728 
 729   bool has_been_redefined() const { return _misc_flags.has_been_redefined(); }
 730   void set_has_been_redefined() { _misc_flags.set_has_been_redefined(true); }
 731 
 732   bool is_scratch_class() const { return _misc_flags.is_scratch_class(); }
 733   void set_is_scratch_class() { _misc_flags.set_is_scratch_class(true); }
 734 
 735   bool has_resolved_methods() const { return _misc_flags.has_resolved_methods(); }
 736   void set_has_resolved_methods()   { _misc_flags.set_has_resolved_methods(true); }
 737   void set_has_resolved_methods(bool value)   { _misc_flags.set_has_resolved_methods(value); }
 738 
 739 public:
 740 #if INCLUDE_JVMTI
 741 
 742   void init_previous_versions() {
 743     _previous_versions = nullptr;
 744   }
 745 
 746  private:
 747   static bool  _should_clean_previous_versions;
 748  public:
 749   static void purge_previous_versions(InstanceKlass* ik) {
 750     if (ik->has_been_redefined()) {
 751       ik->purge_previous_version_list();
 752     }
 753   }
 754 
 755   static bool should_clean_previous_versions_and_reset();
 756   static bool should_clean_previous_versions() { return _should_clean_previous_versions; }
 757 
 758   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 759   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 760     _cached_class_file = data;
 761   }
 762   JvmtiCachedClassFileData * get_cached_class_file();
 763   jint get_cached_class_file_len();
 764   unsigned char * get_cached_class_file_bytes();
 765 
 766   // JVMTI: Support for caching of field indices, types, and offsets
 767   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 768     _jvmti_cached_class_field_map = descriptor;
 769   }
 770   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 771     return _jvmti_cached_class_field_map;
 772   }
 773 #else // INCLUDE_JVMTI
 774 
 775   static void purge_previous_versions(InstanceKlass* ik) { return; };
 776   static bool should_clean_previous_versions_and_reset() { return false; }
 777 
 778   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 779     assert(data == nullptr, "unexpected call with JVMTI disabled");
 780   }
 781   JvmtiCachedClassFileData * get_cached_class_file() { return (JvmtiCachedClassFileData *)nullptr; }
 782 
 783 #endif // INCLUDE_JVMTI
 784 
 785   bool has_nonstatic_concrete_methods() const { return _misc_flags.has_nonstatic_concrete_methods(); }
 786   void set_has_nonstatic_concrete_methods(bool b) { _misc_flags.set_has_nonstatic_concrete_methods(b); }
 787 
 788   bool declares_nonstatic_concrete_methods() const { return _misc_flags.declares_nonstatic_concrete_methods(); }
 789   void set_declares_nonstatic_concrete_methods(bool b) { _misc_flags.set_declares_nonstatic_concrete_methods(b); }
 790 
 791   bool has_vanilla_constructor() const  { return _misc_flags.has_vanilla_constructor(); }
 792   void set_has_vanilla_constructor()    { _misc_flags.set_has_vanilla_constructor(true); }
 793   bool has_miranda_methods () const     { return _misc_flags.has_miranda_methods(); }
 794   void set_has_miranda_methods()        { _misc_flags.set_has_miranda_methods(true); }
 795   bool has_final_method() const         { return _misc_flags.has_final_method(); }
 796   void set_has_final_method()           { _misc_flags.set_has_final_method(true); }
 797 
 798   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 799   inline u2 next_method_idnum();
 800   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 801 
 802   // generics support
 803   Symbol* generic_signature() const;
 804   u2 generic_signature_index() const;
 805   void set_generic_signature_index(u2 sig_index);
 806 
 807   u2 enclosing_method_data(int offset) const;
 808   u2 enclosing_method_class_index() const {
 809     return enclosing_method_data(enclosing_method_class_index_offset);
 810   }
 811   u2 enclosing_method_method_index() {
 812     return enclosing_method_data(enclosing_method_method_index_offset);
 813   }
 814   void set_enclosing_method_indices(u2 class_index,
 815                                     u2 method_index);
 816 
 817   // jmethodID support
 818   jmethodID get_jmethod_id(const methodHandle& method_h);
 819   jmethodID get_jmethod_id_fetch_or_update(size_t idnum,
 820                      jmethodID new_id, jmethodID* new_jmeths,
 821                      jmethodID* to_dealloc_id_p,
 822                      jmethodID** to_dealloc_jmeths_p);
 823   static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
 824                 size_t *length_p, jmethodID* id_p);
 825   void ensure_space_for_methodids(int start_offset = 0);
 826   jmethodID jmethod_id_or_null(Method* method);
 827 
 828   // annotations support
 829   Annotations* annotations() const          { return _annotations; }
 830   void set_annotations(Annotations* anno)   { _annotations = anno; }
 831 
 832   AnnotationArray* class_annotations() const {
 833     return (_annotations != nullptr) ? _annotations->class_annotations() : nullptr;
 834   }
 835   Array<AnnotationArray*>* fields_annotations() const {
 836     return (_annotations != nullptr) ? _annotations->fields_annotations() : nullptr;
 837   }
 838   AnnotationArray* class_type_annotations() const {
 839     return (_annotations != nullptr) ? _annotations->class_type_annotations() : nullptr;
 840   }
 841   Array<AnnotationArray*>* fields_type_annotations() const {
 842     return (_annotations != nullptr) ? _annotations->fields_type_annotations() : nullptr;
 843   }
 844   // allocation
 845   instanceOop allocate_instance(TRAPS);
 846   static instanceOop allocate_instance(oop cls, const char* who, TRAPS);
 847 
 848   // additional member function to return a handle
 849   instanceHandle allocate_instance_handle(TRAPS);
 850 
 851   objArrayOop allocate_objArray(int n, int length, TRAPS);
 852   // Helper function
 853   static instanceOop register_finalizer(instanceOop i, TRAPS);
 854 
 855   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 856   // if not, throw either an Error or an Exception.
 857   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 858 
 859   // initialization
 860   void call_class_initializer(TRAPS);
 861   void set_initialization_state_and_notify(ClassState state, JavaThread* current);
 862   void record_initialization_touch(const char* request,
 863                                    Symbol* name,  // or nullptr if not a member
 864                                    Symbol* sig,   // or nullptr if not a method
 865                                    Klass* requesting_klass,  // or nullptr
 866                                    const char* context,      // or nullptr
 867                                    TRAPS);
 868   bool has_initialization_touch() const;
 869 
 870   // OopMapCache support
 871   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 872   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 873   void mask_for(const methodHandle& method, int bci, InterpreterOopMap* entry);
 874 
 875   // JNI identifier support (for static fields - for jni performance)
 876   JNIid* jni_ids()                               { return _jni_ids; }
 877   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 878   JNIid* jni_id_for(int offset);
 879 
 880   // maintenance of deoptimization dependencies
 881   inline DependencyContext dependencies();
 882   void mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes);
 883   void add_dependent_nmethod(nmethod* nm);
 884   void clean_dependency_context();
 885   // Setup link to hierarchy and deoptimize
 886   void add_to_hierarchy(JavaThread* current);
 887 
 888   // On-stack replacement support
 889   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 890   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 891   void add_osr_nmethod(nmethod* n);
 892   bool remove_osr_nmethod(nmethod* n);
 893   int mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m);
 894   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 895 
 896 #if INCLUDE_JVMTI
 897   // Breakpoint support (see methods on Method* for details)
 898   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 899   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 900 #endif
 901 
 902   // support for stub routines
 903   static ByteSize init_state_offset()  { return byte_offset_of(InstanceKlass, _init_state); }
 904   JFR_ONLY(DEFINE_KLASS_TRACE_ID_OFFSET;)
 905   static ByteSize init_thread_offset() { return byte_offset_of(InstanceKlass, _init_thread); }
 906 
 907   // subclass/subinterface checks
 908   bool implements_interface(Klass* k) const;
 909   bool is_same_or_direct_interface(Klass* k) const;
 910 
 911 #ifdef ASSERT
 912   // check whether this class or one of its superclasses was redefined
 913   bool has_redefined_this_or_super() const;
 914 #endif
 915 
 916   // Access to the implementor of an interface.
 917   InstanceKlass* implementor() const;
 918   void set_implementor(InstanceKlass* ik);
 919   int  nof_implementors() const;
 920   void add_implementor(InstanceKlass* ik);  // ik is a new class that implements this interface
 921   void init_implementor();           // initialize
 922 
 923  private:
 924   // link this class into the implementors list of every interface it implements
 925   void process_interfaces();
 926 
 927  public:
 928   // virtual operations from Klass
 929   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
 930                                                   Array<InstanceKlass*>* transitive_interfaces);
 931   bool can_be_primary_super_slow() const;
 932   size_t oop_size(oop obj)  const             { return size_helper(); }
 933   // slow because it's a virtual call and used for verifying the layout_helper.
 934   // Using the layout_helper bits, we can call is_instance_klass without a virtual call.
 935   DEBUG_ONLY(bool is_instance_klass_slow() const      { return true; })
 936 
 937   // Iterators
 938   void do_local_static_fields(FieldClosure* cl);
 939   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
 940   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
 941   void print_nonstatic_fields(FieldClosure* cl); // including inherited and injected fields
 942 
 943   void methods_do(void f(Method* method));
 944 
 945   static InstanceKlass* cast(Klass* k) {
 946     return const_cast<InstanceKlass*>(cast(const_cast<const Klass*>(k)));
 947   }
 948 
 949   static const InstanceKlass* cast(const Klass* k) {
 950     assert(k != nullptr, "k should not be null");
 951     assert(k->is_instance_klass(), "cast to InstanceKlass");
 952     return static_cast<const InstanceKlass*>(k);
 953   }
 954 
 955   virtual InstanceKlass* java_super() const {
 956     return (super() == nullptr) ? nullptr : cast(super());
 957   }
 958 
 959   // Sizing (in words)
 960   static int header_size()            { return sizeof(InstanceKlass)/wordSize; }
 961 
 962   static int size(int vtable_length, int itable_length,
 963                   int nonstatic_oop_map_size,
 964                   bool is_interface) {
 965     return align_metadata_size(header_size() +
 966            vtable_length +
 967            itable_length +
 968            nonstatic_oop_map_size +
 969            (is_interface ? (int)sizeof(Klass*)/wordSize : 0));
 970   }
 971 
 972   int size() const                    { return size(vtable_length(),
 973                                                itable_length(),
 974                                                nonstatic_oop_map_size(),
 975                                                is_interface());
 976   }
 977 
 978 
 979   inline intptr_t* start_of_itable() const;
 980   inline intptr_t* end_of_itable() const;
 981   inline oop static_field_base_raw();
 982 
 983   inline OopMapBlock* start_of_nonstatic_oop_maps() const;
 984   inline Klass** end_of_nonstatic_oop_maps() const;
 985 
 986   inline InstanceKlass* volatile* adr_implementor() const;
 987 
 988   // Use this to return the size of an instance in heap words:
 989   int size_helper() const {
 990     return layout_helper_to_size_helper(layout_helper());
 991   }
 992 
 993   // This bit is initialized in classFileParser.cpp.
 994   // It is false under any of the following conditions:
 995   //  - the class is abstract (including any interface)
 996   //  - the class has a finalizer (if !RegisterFinalizersAtInit)
 997   //  - the class size is larger than FastAllocateSizeLimit
 998   //  - the class is java/lang/Class, which cannot be allocated directly
 999   bool can_be_fastpath_allocated() const {
1000     return !layout_helper_needs_slow_path(layout_helper());
1001   }
1002 
1003   // Java itable
1004   klassItable itable() const;        // return klassItable wrapper
1005   Method* method_at_itable(InstanceKlass* holder, int index, TRAPS);
1006   Method* method_at_itable_or_null(InstanceKlass* holder, int index, bool& itable_entry_found);
1007   int vtable_index_of_interface_method(Method* method);
1008 
1009 #if INCLUDE_JVMTI
1010   void adjust_default_methods(bool* trace_name_printed);
1011 #endif // INCLUDE_JVMTI
1012 
1013   void clean_weak_instanceklass_links();
1014  private:
1015   void clean_implementors_list();
1016   void clean_method_data();
1017 
1018  public:
1019   // Explicit metaspace deallocation of fields
1020   // For RedefineClasses and class file parsing errors, we need to deallocate
1021   // instanceKlasses and the metadata they point to.
1022   void deallocate_contents(ClassLoaderData* loader_data);
1023   static void deallocate_methods(ClassLoaderData* loader_data,
1024                                  Array<Method*>* methods);
1025   void static deallocate_interfaces(ClassLoaderData* loader_data,
1026                                     const Klass* super_klass,
1027                                     Array<InstanceKlass*>* local_interfaces,
1028                                     Array<InstanceKlass*>* transitive_interfaces);
1029   void static deallocate_record_components(ClassLoaderData* loader_data,
1030                                            Array<RecordComponent*>* record_component);
1031 
1032   virtual bool on_stack() const;
1033 
1034   // callbacks for actions during class unloading
1035   static void unload_class(InstanceKlass* ik);
1036 
1037   virtual void release_C_heap_structures(bool release_sub_metadata = true);
1038 
1039   // Naming
1040   const char* signature_name() const;
1041 
1042   // Oop fields (and metadata) iterators
1043   //
1044   // The InstanceKlass iterators also visits the Object's klass.
1045 
1046   // Forward iteration
1047  public:
1048   // Iterate over all oop fields in the oop maps.
1049   template <typename T, class OopClosureType>
1050   inline void oop_oop_iterate_oop_maps(oop obj, OopClosureType* closure);
1051 
1052   // Iterate over all oop fields and metadata.
1053   template <typename T, class OopClosureType>
1054   inline void oop_oop_iterate(oop obj, OopClosureType* closure);
1055 
1056   // Iterate over all oop fields in one oop map.
1057   template <typename T, class OopClosureType>
1058   inline void oop_oop_iterate_oop_map(OopMapBlock* map, oop obj, OopClosureType* closure);
1059 
1060 
1061   // Reverse iteration
1062   // Iterate over all oop fields and metadata.
1063   template <typename T, class OopClosureType>
1064   inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
1065 
1066  private:
1067   // Iterate over all oop fields in the oop maps.
1068   template <typename T, class OopClosureType>
1069   inline void oop_oop_iterate_oop_maps_reverse(oop obj, OopClosureType* closure);
1070 
1071   // Iterate over all oop fields in one oop map.
1072   template <typename T, class OopClosureType>
1073   inline void oop_oop_iterate_oop_map_reverse(OopMapBlock* map, oop obj, OopClosureType* closure);
1074 
1075 
1076   // Bounded range iteration
1077  public:
1078   // Iterate over all oop fields in the oop maps.
1079   template <typename T, class OopClosureType>
1080   inline void oop_oop_iterate_oop_maps_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1081 
1082   // Iterate over all oop fields and metadata.
1083   template <typename T, class OopClosureType>
1084   inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1085 
1086  private:
1087   // Iterate over all oop fields in one oop map.
1088   template <typename T, class OopClosureType>
1089   inline void oop_oop_iterate_oop_map_bounded(OopMapBlock* map, oop obj, OopClosureType* closure, MemRegion mr);
1090 
1091 
1092  public:
1093   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
1094 
1095  private:
1096   // initialization state
1097   void set_init_state(ClassState state);
1098   void set_rewritten()                  { _misc_flags.set_rewritten(true); }
1099   void set_init_thread(JavaThread *thread)  {
1100     assert((thread == JavaThread::current() && _init_thread == nullptr) ||
1101            (thread == nullptr && _init_thread == JavaThread::current()), "Only one thread is allowed to own initialization");
1102     Atomic::store(&_init_thread, thread);
1103   }
1104 
1105   // The RedefineClasses() API can cause new method idnums to be needed
1106   // which will cause the caches to grow. Safety requires different
1107   // cache management logic if the caches can grow instead of just
1108   // going from null to non-null.
1109   bool idnum_can_increment() const      { return has_been_redefined(); }
1110   inline jmethodID* methods_jmethod_ids_acquire() const;
1111   inline void release_set_methods_jmethod_ids(jmethodID* jmeths);
1112   // This nulls out jmethodIDs for all methods in 'klass'
1113   static void clear_jmethod_ids(InstanceKlass* klass);
1114 
1115   // Lock during initialization
1116 public:
1117   // Returns the array class for the n'th dimension
1118   virtual ArrayKlass* array_klass(int n, TRAPS);
1119   virtual ArrayKlass* array_klass_or_null(int n);
1120 
1121   // Returns the array class with this class as element type
1122   virtual ArrayKlass* array_klass(TRAPS);
1123   virtual ArrayKlass* array_klass_or_null();
1124 
1125   static void clean_initialization_error_table();
1126 
1127   Monitor* init_monitor() const { return _init_monitor; }
1128 private:
1129   void check_link_state_and_wait(JavaThread* current);
1130   bool link_class_impl                           (TRAPS);
1131   bool verify_code                               (TRAPS);
1132   void initialize_impl                           (TRAPS);
1133   void initialize_super_interfaces(Klass* requester, TRAPS);
1134 
1135   void add_initialization_error(JavaThread* current, Handle exception);
1136   oop get_initialization_error(JavaThread* current);
1137 
1138   // find a local method (returns null if not found)
1139   Method* find_method_impl(const Symbol* name,
1140                            const Symbol* signature,
1141                            OverpassLookupMode overpass_mode,
1142                            StaticLookupMode static_mode,
1143                            PrivateLookupMode private_mode) const;
1144 
1145   static Method* find_method_impl(const Array<Method*>* methods,
1146                                   const Symbol* name,
1147                                   const Symbol* signature,
1148                                   OverpassLookupMode overpass_mode,
1149                                   StaticLookupMode static_mode,
1150                                   PrivateLookupMode private_mode);
1151 
1152 #if INCLUDE_JVMTI
1153   // RedefineClasses support
1154   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1155   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1156 #endif
1157   // log class name to classlist
1158   void log_to_classlist() const;
1159 public:
1160 
1161 #if INCLUDE_CDS
1162   // CDS support - remove and restore oops from metadata. Oops are not shared.
1163   virtual void remove_unshareable_info();
1164   void remove_unshareable_flags();
1165   virtual void remove_java_mirror();
1166   void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
1167   void init_shared_package_entry();
1168   bool can_be_verified_at_dumptime() const;
1169   bool methods_contain_jsr_bytecode() const;
1170   void compute_has_loops_flag_for_methods();
1171 #endif
1172 
1173   jint compute_modifier_flags() const;
1174 
1175 public:
1176   // JVMTI support
1177   jint jvmti_class_status() const;
1178 
1179   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
1180 
1181  public:
1182   // Printing
1183   void print_on(outputStream* st) const;
1184   void print_value_on(outputStream* st) const;
1185 
1186   void oop_print_value_on(oop obj, outputStream* st);
1187 
1188   void oop_print_on      (oop obj, outputStream* st);
1189 
1190 #ifndef PRODUCT
1191   void print_dependent_nmethods(bool verbose = false);
1192   bool is_dependent_nmethod(nmethod* nm);
1193   bool verify_itable_index(int index);
1194 #endif
1195 
1196   const char* internal_name() const;
1197 
1198   // Verification
1199   void verify_on(outputStream* st);
1200 
1201   void oop_verify_on(oop obj, outputStream* st);
1202 
1203   // Logging
1204   void print_class_load_logging(ClassLoaderData* loader_data,
1205                                 const ModuleEntry* module_entry,
1206                                 const ClassFileStream* cfs) const;
1207  private:
1208   void print_class_load_cause_logging() const;
1209   void print_class_load_helper(ClassLoaderData* loader_data,
1210                                const ModuleEntry* module_entry,
1211                                const ClassFileStream* cfs) const;
1212 };
1213 
1214 // for adding methods
1215 // UNSET_IDNUM return means no more ids available
1216 inline u2 InstanceKlass::next_method_idnum() {
1217   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1218     return ConstMethod::UNSET_IDNUM; // no more ids available
1219   } else {
1220     return _idnum_allocated_count++;
1221   }
1222 }
1223 
1224 class PrintClassClosure : public KlassClosure {
1225 private:
1226   outputStream* _st;
1227   bool _verbose;
1228 public:
1229   PrintClassClosure(outputStream* st, bool verbose);
1230 
1231   void do_klass(Klass* k);
1232 };
1233 
1234 /* JNIid class for jfieldIDs only */
1235 class JNIid: public CHeapObj<mtClass> {
1236   friend class VMStructs;
1237  private:
1238   Klass*             _holder;
1239   JNIid*             _next;
1240   int                _offset;
1241 #ifdef ASSERT
1242   bool               _is_static_field_id;
1243 #endif
1244 
1245  public:
1246   // Accessors
1247   Klass* holder() const           { return _holder; }
1248   int offset() const              { return _offset; }
1249   JNIid* next()                   { return _next; }
1250   // Constructor
1251   JNIid(Klass* holder, int offset, JNIid* next);
1252   // Identifier lookup
1253   JNIid* find(int offset);
1254 
1255   bool find_local_field(fieldDescriptor* fd) {
1256     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1257   }
1258 
1259   static void deallocate(JNIid* id);
1260   // Debugging
1261 #ifdef ASSERT
1262   bool is_static_field_id() const { return _is_static_field_id; }
1263   void set_is_static_field_id()   { _is_static_field_id = true; }
1264 #endif
1265   void verify(Klass* holder);
1266 };
1267 
1268 // An iterator that's used to access the inner classes indices in the
1269 // InstanceKlass::_inner_classes array.
1270 class InnerClassesIterator : public StackObj {
1271  private:
1272   Array<jushort>* _inner_classes;
1273   int _length;
1274   int _idx;
1275  public:
1276 
1277   InnerClassesIterator(const InstanceKlass* k) {
1278     _inner_classes = k->inner_classes();
1279     if (k->inner_classes() != nullptr) {
1280       _length = _inner_classes->length();
1281       // The inner class array's length should be the multiple of
1282       // inner_class_next_offset if it only contains the InnerClasses
1283       // attribute data, or it should be
1284       // n*inner_class_next_offset+enclosing_method_attribute_size
1285       // if it also contains the EnclosingMethod data.
1286       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1287               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1288              "just checking");
1289       // Remove the enclosing_method portion if exists.
1290       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1291         _length -= InstanceKlass::enclosing_method_attribute_size;
1292       }
1293     } else {
1294       _length = 0;
1295     }
1296     _idx = 0;
1297   }
1298 
1299   int length() const {
1300     return _length;
1301   }
1302 
1303   void next() {
1304     _idx += InstanceKlass::inner_class_next_offset;
1305   }
1306 
1307   bool done() const {
1308     return (_idx >= _length);
1309   }
1310 
1311   u2 inner_class_info_index() const {
1312     return _inner_classes->at(
1313                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1314   }
1315 
1316   void set_inner_class_info_index(u2 index) {
1317     _inner_classes->at_put(
1318                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1319   }
1320 
1321   u2 outer_class_info_index() const {
1322     return _inner_classes->at(
1323                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1324   }
1325 
1326   void set_outer_class_info_index(u2 index) {
1327     _inner_classes->at_put(
1328                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1329   }
1330 
1331   u2 inner_name_index() const {
1332     return _inner_classes->at(
1333                _idx + InstanceKlass::inner_class_inner_name_offset);
1334   }
1335 
1336   void set_inner_name_index(u2 index) {
1337     _inner_classes->at_put(
1338                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1339   }
1340 
1341   u2 inner_access_flags() const {
1342     return _inner_classes->at(
1343                _idx + InstanceKlass::inner_class_access_flags_offset);
1344   }
1345 };
1346 
1347 // Iterator over class hierarchy under a particular class. Implements depth-first pre-order traversal.
1348 // Usage:
1349 //  for (ClassHierarchyIterator iter(root_klass); !iter.done(); iter.next()) {
1350 //    Klass* k = iter.klass();
1351 //    ...
1352 //  }
1353 class ClassHierarchyIterator : public StackObj {
1354  private:
1355   InstanceKlass* _root;
1356   Klass*         _current;
1357   bool           _visit_subclasses;
1358 
1359  public:
1360   ClassHierarchyIterator(InstanceKlass* root) : _root(root), _current(root), _visit_subclasses(true) {
1361     assert(_root == _current, "required"); // initial state
1362   }
1363 
1364   bool done() {
1365     return (_current == nullptr);
1366   }
1367 
1368   // Make a step iterating over the class hierarchy under the root class.
1369   // Skips subclasses if requested.
1370   void next();
1371 
1372   Klass* klass() {
1373     assert(!done(), "sanity");
1374     return _current;
1375   }
1376 
1377   // Skip subclasses of the current class.
1378   void skip_subclasses() {
1379     _visit_subclasses = false;
1380   }
1381 };
1382 
1383 #endif // SHARE_OOPS_INSTANCEKLASS_HPP