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 "code/vmreg.hpp"
  29 #include "memory/referenceType.hpp"
  30 #include "oops/annotations.hpp"
  31 #include "oops/constMethod.hpp"
  32 #include "oops/fieldInfo.hpp"
  33 #include "oops/instanceKlassFlags.hpp"
  34 #include "oops/instanceOop.hpp"
  35 #include "runtime/handles.hpp"
  36 #include "runtime/javaThread.hpp"
  37 #include "utilities/accessFlags.hpp"
  38 #include "utilities/align.hpp"
  39 #include "utilities/growableArray.hpp"
  40 #include "utilities/macros.hpp"
  41 #if INCLUDE_JFR
  42 #include "jfr/support/jfrKlassExtension.hpp"
  43 #endif
  44 
  45 class ConstantPool;
  46 class DeoptimizationScope;
  47 class klassItable;
  48 class Monitor;
  49 class RecordComponent;
  50 
  51 // An InstanceKlass is the VM level representation of a Java class.
  52 // It contains all information needed for at class at execution runtime.
  53 
  54 //  InstanceKlass embedded field layout (after declared fields):
  55 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  56 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  57 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  58 //      indicating where oops are located in instances of this klass.
  59 //    [EMBEDDED implementor of the interface] only exist for interface
  60 //    [EMBEDDED inline_type_field_klasses] only if has_inline_fields() == true
  61 //    [EMBEDDED InlineKlassFixedBlock] only if is an InlineKlass instance
  62 
  63 
  64 // forward declaration for class -- see below for definition
  65 #if INCLUDE_JVMTI
  66 class BreakpointInfo;
  67 #endif
  68 class ClassFileParser;
  69 class ClassFileStream;
  70 class KlassDepChange;
  71 class DependencyContext;
  72 class fieldDescriptor;
  73 class jniIdMapBase;
  74 class JNIid;
  75 class JvmtiCachedClassFieldMap;
  76 class nmethodBucket;
  77 class OopMapCache;
  78 class BufferedInlineTypeBlob;
  79 class InterpreterOopMap;
  80 class PackageEntry;
  81 class ModuleEntry;
  82 
  83 // This is used in iterators below.
  84 class FieldClosure: public StackObj {
  85 public:
  86   virtual void do_field(fieldDescriptor* fd) = 0;
  87 };
  88 
  89 // Print fields.
  90 // If "obj" argument to constructor is null, prints static fields, otherwise prints non-static fields.
  91 class FieldPrinter: public FieldClosure {
  92    oop _obj;
  93    outputStream* _st;
  94  public:
  95    FieldPrinter(outputStream* st, oop obj = nullptr) : _obj(obj), _st(st) {}
  96    void do_field(fieldDescriptor* fd);
  97 };
  98 
  99 // Describes where oops are located in instances of this klass.
 100 class OopMapBlock {
 101  public:
 102   // Byte offset of the first oop mapped by this block.
 103   int offset() const          { return _offset; }
 104   void set_offset(int offset) { _offset = offset; }
 105 
 106   // Number of oops in this block.
 107   uint count() const         { return _count; }
 108   void set_count(uint count) { _count = count; }
 109 
 110   void increment_count(int diff) { _count += diff; }
 111 
 112   int offset_span() const { return _count * heapOopSize; }
 113 
 114   int end_offset() const {
 115     return offset() + offset_span();
 116   }
 117 
 118   bool is_contiguous(int another_offset) const {
 119     return another_offset == end_offset();
 120   }
 121 
 122   // sizeof(OopMapBlock) in words.
 123   static int size_in_words() {
 124     return align_up((int)sizeof(OopMapBlock), wordSize) >>
 125       LogBytesPerWord;
 126   }
 127 
 128   static int compare_offset(const OopMapBlock* a, const OopMapBlock* b) {
 129     return a->offset() - b->offset();
 130   }
 131 
 132  private:
 133   int  _offset;
 134   uint _count;
 135 };
 136 
 137 struct JvmtiCachedClassFileData;
 138 
 139 class SigEntry;
 140 
 141 class InlineKlassFixedBlock {
 142   Array<SigEntry>** _extended_sig;
 143   Array<VMRegPair>** _return_regs;
 144   address* _pack_handler;
 145   address* _pack_handler_jobject;
 146   address* _unpack_handler;
 147   int* _default_value_offset;
 148   ArrayKlass** _null_free_inline_array_klasses;
 149   int _alignment;
 150   int _first_field_offset;
 151   int _exact_size_in_bytes;
 152 
 153   friend class InlineKlass;
 154 };
 155 
 156 class InstanceKlass: public Klass {
 157   friend class VMStructs;
 158   friend class JVMCIVMStructs;
 159   friend class ClassFileParser;
 160   friend class CompileReplay;
 161   friend class TemplateTable;
 162 
 163  public:
 164   static const KlassKind Kind = InstanceKlassKind;
 165 
 166  protected:
 167   InstanceKlass(const ClassFileParser& parser, KlassKind kind = Kind, ReferenceType reference_type = REF_NONE);
 168 
 169  public:
 170   InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
 171 
 172   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 173   // of the class loading & initialization procedure, and the use of the states.
 174   enum ClassState : u1 {
 175     allocated,                          // allocated (but not yet linked)
 176     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 177     being_linked,                       // currently running verifier and rewriter
 178     linked,                             // successfully linked/verified (but not initialized yet)
 179     being_initialized,                  // currently running class initializer
 180     fully_initialized,                  // initialized (successful final state)
 181     initialization_error                // error happened during initialization
 182   };
 183 
 184  private:
 185   static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);
 186 
 187  protected:
 188   // If you add a new field that points to any metaspace object, you
 189   // must add this field to InstanceKlass::metaspace_pointers_do().
 190 
 191   // Annotations for this class
 192   Annotations*    _annotations;
 193   // Package this class is defined in
 194   PackageEntry*   _package_entry;
 195   // Array classes holding elements of this class.
 196   ArrayKlass* volatile _array_klasses;
 197   // Constant pool for this class.
 198   ConstantPool* _constants;
 199   // The InnerClasses attribute and EnclosingMethod attribute. The
 200   // _inner_classes is an array of shorts. If the class has InnerClasses
 201   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 202   // [inner_class_info_index, outer_class_info_index,
 203   // inner_name_index, inner_class_access_flags] for the InnerClasses
 204   // attribute. If the EnclosingMethod attribute exists, it occupies the
 205   // last two shorts [class_index, method_index] of the array. If only
 206   // the InnerClasses attribute exists, the _inner_classes array length is
 207   // number_of_inner_classes * 4. If the class has both InnerClasses
 208   // and EnclosingMethod attributes the _inner_classes array length is
 209   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 210   Array<jushort>* _inner_classes;
 211 
 212   // The NestMembers attribute. An array of shorts, where each is a
 213   // class info index for the class that is a nest member. This data
 214   // has not been validated.
 215   Array<jushort>* _nest_members;
 216 
 217   // Resolved nest-host klass: either true nest-host or self if we are not
 218   // nested, or an error occurred resolving or validating the nominated
 219   // nest-host. Can also be set directly by JDK API's that establish nest
 220   // relationships.
 221   // By always being set it makes nest-member access checks simpler.
 222   InstanceKlass* _nest_host;
 223 
 224   // The PermittedSubclasses attribute. An array of shorts, where each is a
 225   // class info index for the class that is a permitted subclass.
 226   Array<jushort>* _permitted_subclasses;
 227 
 228   // The contents of the Record attribute.
 229   Array<RecordComponent*>* _record_components;
 230 
 231   // the source debug extension for this klass, null if not specified.
 232   // Specified as UTF-8 string without terminating zero byte in the classfile,
 233   // it is stored in the instanceklass as a null-terminated UTF-8 string
 234   const char*     _source_debug_extension;
 235 
 236   // Number of heapOopSize words used by non-static fields in this klass
 237   // (including inherited fields but after header_size()).
 238   int             _nonstatic_field_size;
 239   int             _static_field_size;       // number words used by static fields (oop and non-oop) in this klass
 240   int             _nonstatic_oop_map_size;  // size in words of nonstatic oop map blocks
 241   int             _itable_len;              // length of Java itable (in words)
 242 
 243   // The NestHost attribute. The class info index for the class
 244   // that is the nest-host of this class. This data has not been validated.
 245   u2              _nest_host_index;
 246   u2              _this_class_index;        // constant pool entry
 247   u2              _static_oop_field_count;  // number of static oop fields in this klass
 248 
 249   volatile u2     _idnum_allocated_count;   // JNI/JVMTI: increments with the addition of methods, old ids don't change
 250 
 251   volatile ClassState _init_state;          // state of class
 252 
 253   u1              _reference_type;          // reference type
 254 
 255   // State is set either at parse time or while executing, atomically to not disturb other state
 256   InstanceKlassFlags _misc_flags;
 257 
 258   Monitor*             _init_monitor;       // mutual exclusion to _init_state and _init_thread.
 259   JavaThread* volatile _init_thread;        // Pointer to current thread doing initialization (to handle recursive initialization)
 260 
 261   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 262   JNIid*          _jni_ids;              // First JNI identifier for static fields in this class
 263   jmethodID*      volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or null if none
 264   nmethodBucket*  volatile _dep_context;          // packed DependencyContext structure
 265   uint64_t        volatile _dep_context_last_cleaned;
 266   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 267 #if INCLUDE_JVMTI
 268   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 269   // Linked instanceKlasses of previous versions
 270   InstanceKlass* _previous_versions;
 271   // JVMTI fields can be moved to their own structure - see 6315920
 272   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 273   JvmtiCachedClassFileData* _cached_class_file;
 274 #endif
 275 
 276 #if INCLUDE_JVMTI
 277   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 278 #endif
 279 
 280   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 281   NOT_PRODUCT(volatile int _shared_class_load_count;) // ensure a shared class is loaded only once
 282 
 283   // Method array.
 284   Array<Method*>* _methods;
 285   // Default Method Array, concrete methods inherited from interfaces
 286   Array<Method*>* _default_methods;
 287   // Interfaces (InstanceKlass*s) this class declares locally to implement.
 288   Array<InstanceKlass*>* _local_interfaces;
 289   // Interfaces (InstanceKlass*s) this class implements transitively.
 290   Array<InstanceKlass*>* _transitive_interfaces;
 291   // Int array containing the original order of method in the class file (for JVMTI).
 292   Array<int>*     _method_ordering;
 293   // Int array containing the vtable_indices for default_methods
 294   // offset matches _default_methods offset
 295   Array<int>*     _default_vtable_indices;
 296 
 297   // Fields information is stored in an UNSIGNED5 encoded stream (see fieldInfo.hpp)
 298   Array<u1>*          _fieldinfo_stream;
 299   Array<FieldStatus>* _fields_status;
 300 
 301   const Klass**   _inline_type_field_klasses; // For "inline class" fields, null if none present
 302   Array<u2>* _preload_classes;
 303   const InlineKlassFixedBlock* _adr_inlineklass_fixed_block;
 304 
 305   // embedded Java vtable follows here
 306   // embedded Java itables follows here
 307   // embedded static fields follows here
 308   // embedded nonstatic oop-map blocks follows here
 309   // embedded implementor of this interface follows here
 310   //   The embedded implementor only exists if the current klass is an
 311   //   interface. The possible values of the implementor fall into following
 312   //   three cases:
 313   //     null: no implementor.
 314   //     A Klass* that's not itself: one implementor.
 315   //     Itself: more than one implementors.
 316   //
 317 
 318   friend class SystemDictionary;
 319 
 320   static bool _disable_method_binary_search;
 321 
 322   // Controls finalizer registration
 323   static bool _finalization_enabled;
 324 
 325  public:
 326 
 327   // Queries finalization state
 328   static bool is_finalization_enabled() { return _finalization_enabled; }
 329 
 330   // Sets finalization state
 331   static void set_finalization_enabled(bool val) { _finalization_enabled = val; }
 332 
 333   // The three BUILTIN class loader types
 334   bool is_shared_boot_class() const { return _misc_flags.is_shared_boot_class(); }
 335   bool is_shared_platform_class() const { return _misc_flags.is_shared_platform_class(); }
 336   bool is_shared_app_class() const {  return _misc_flags.is_shared_app_class(); }
 337   // The UNREGISTERED class loader type
 338   bool is_shared_unregistered_class() const { return _misc_flags.is_shared_unregistered_class(); }
 339 
 340   // Check if the class can be shared in CDS
 341   bool is_shareable() const;
 342 
 343   bool shared_loading_failed() const { return _misc_flags.shared_loading_failed(); }
 344 
 345   void set_shared_loading_failed() { _misc_flags.set_shared_loading_failed(true); }
 346 
 347 #if INCLUDE_CDS
 348   void set_shared_class_loader_type(s2 loader_type) { _misc_flags.set_shared_class_loader_type(loader_type); }
 349   void assign_class_loader_type() { _misc_flags.assign_class_loader_type(_class_loader_data); }
 350 #endif
 351 
 352   bool has_nonstatic_fields() const        { return _misc_flags.has_nonstatic_fields(); }
 353   void set_has_nonstatic_fields(bool b)    { _misc_flags.set_has_nonstatic_fields(b); }
 354 
 355   bool has_localvariable_table() const     { return _misc_flags.has_localvariable_table(); }
 356   void set_has_localvariable_table(bool b) { _misc_flags.set_has_localvariable_table(b); }
 357 
 358   bool has_inline_type_fields() const { return _misc_flags.has_inline_type_fields(); }
 359   void set_has_inline_type_fields()   { _misc_flags.set_has_inline_type_fields(true); }
 360 
 361   bool is_empty_inline_type() const   { return _misc_flags.is_empty_inline_type(); }
 362   void set_is_empty_inline_type()     { _misc_flags.set_is_empty_inline_type(true); }
 363 
 364   // Note:  The naturally_atomic property only applies to
 365   // inline classes; it is never true on identity classes.
 366   // The bit is placed on instanceKlass for convenience.
 367 
 368   // Query if h/w provides atomic load/store for instances.
 369   bool is_naturally_atomic() const  { return _misc_flags.is_naturally_atomic(); }
 370   void set_is_naturally_atomic()    { _misc_flags.set_is_naturally_atomic(true); }
 371 
 372   // Query if this class implements jl.NonTearable or was
 373   // mentioned in the JVM option ForceNonTearable.
 374   // This bit can occur anywhere, but is only significant
 375   // for inline classes *and* their super types.
 376   // It inherits from supers along with NonTearable.
 377   bool is_declared_atomic() const { return _misc_flags.is_declared_atomic(); }
 378   void set_is_declared_atomic()   { _misc_flags.set_is_declared_atomic(true); }
 379 
 380   bool carries_value_modifier() const { return _misc_flags.carries_value_modifier(); }
 381   void set_carries_value_modifier()   { _misc_flags.set_carries_value_modifier(true); }
 382 
 383   bool carries_identity_modifier() const  { return _misc_flags.carries_identity_modifier(); }
 384   void set_carries_identity_modifier()    { _misc_flags.set_carries_identity_modifier(true); }
 385 
 386   // field sizes
 387   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 388   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 389 
 390   int static_field_size() const            { return _static_field_size; }
 391   void set_static_field_size(int size)     { _static_field_size = size; }
 392 
 393   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 394   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 395 
 396   // Java itable
 397   int  itable_length() const               { return _itable_len; }
 398   void set_itable_length(int len)          { _itable_len = len; }
 399 
 400   // array klasses
 401   ArrayKlass* array_klasses() const     { return _array_klasses; }
 402   inline ArrayKlass* array_klasses_acquire() const; // load with acquire semantics
 403   inline void release_set_array_klasses(ArrayKlass* k); // store with release semantics
 404 
 405   // methods
 406   Array<Method*>* methods() const          { return _methods; }
 407   void set_methods(Array<Method*>* a)      { _methods = a; }
 408   Method* method_with_idnum(int idnum);
 409   Method* method_with_orig_idnum(int idnum);
 410   Method* method_with_orig_idnum(int idnum, int version);
 411 
 412   // method ordering
 413   Array<int>* method_ordering() const     { return _method_ordering; }
 414   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 415   void copy_method_ordering(const intArray* m, TRAPS);
 416 
 417   // default_methods
 418   Array<Method*>* default_methods() const  { return _default_methods; }
 419   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 420 
 421   // default method vtable_indices
 422   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 423   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 424   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 425 
 426   // interfaces
 427   Array<InstanceKlass*>* local_interfaces() const          { return _local_interfaces; }
 428   void set_local_interfaces(Array<InstanceKlass*>* a)      {
 429     guarantee(_local_interfaces == nullptr || a == nullptr, "Just checking");
 430     _local_interfaces = a; }
 431 
 432   Array<InstanceKlass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 433   void set_transitive_interfaces(Array<InstanceKlass*>* a) {
 434     guarantee(_transitive_interfaces == nullptr || a == nullptr, "Just checking");
 435     _transitive_interfaces = a;
 436   }
 437 
 438  private:
 439   friend class fieldDescriptor;
 440   FieldInfo field(int index) const;
 441 
 442  public:
 443   int     field_offset      (int index) const { return field(index).offset(); }
 444   int     field_access_flags(int index) const { return field(index).access_flags().as_int(); }
 445   FieldInfo::FieldFlags field_flags(int index) const { return field(index).field_flags(); }
 446   FieldStatus field_status(int index)   const { return fields_status()->at(index); }
 447   inline Symbol* field_name        (int index) const;
 448   inline Symbol* field_signature   (int index) const;
 449   bool    field_is_flat(int index) const { return field_flags(index).is_flat(); }
 450   bool    field_is_null_free_inline_type(int index) const;
 451 
 452   // Number of Java declared fields
 453   int java_fields_count() const;
 454   int total_fields_count() const;
 455 
 456   Array<u1>* fieldinfo_stream() const { return _fieldinfo_stream; }
 457   void set_fieldinfo_stream(Array<u1>* fis) { _fieldinfo_stream = fis; }
 458 
 459   Array<FieldStatus>* fields_status() const {return _fields_status; }
 460   void set_fields_status(Array<FieldStatus>* array) { _fields_status = array; }
 461 
 462   Array<u2>* preload_classes() const { return _preload_classes; }
 463   void set_preload_classes(Array<u2>* c) { _preload_classes = c; }
 464 
 465   // inner classes
 466   Array<u2>* inner_classes() const       { return _inner_classes; }
 467   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 468 
 469   // nest members
 470   Array<u2>* nest_members() const     { return _nest_members; }
 471   void set_nest_members(Array<u2>* m) { _nest_members = m; }
 472 
 473   // nest-host index
 474   jushort nest_host_index() const { return _nest_host_index; }
 475   void set_nest_host_index(u2 i)  { _nest_host_index = i; }
 476   // dynamic nest member support
 477   void set_nest_host(InstanceKlass* host);
 478 
 479   // record components
 480   Array<RecordComponent*>* record_components() const { return _record_components; }
 481   void set_record_components(Array<RecordComponent*>* record_components) {
 482     _record_components = record_components;
 483   }
 484   bool is_record() const;
 485 
 486   // permitted subclasses
 487   Array<u2>* permitted_subclasses() const     { return _permitted_subclasses; }
 488   void set_permitted_subclasses(Array<u2>* s) { _permitted_subclasses = s; }
 489 
 490 private:
 491   // Called to verify that k is a member of this nest - does not look at k's nest-host,
 492   // nor does it resolve any CP entries or load any classes.
 493   bool has_nest_member(JavaThread* current, InstanceKlass* k) const;
 494 
 495 public:
 496   // Call this only if you know that the nest host has been initialized.
 497   InstanceKlass* nest_host_not_null() {
 498     assert(_nest_host != nullptr, "must be");
 499     return _nest_host;
 500   }
 501   // Used to construct informative IllegalAccessError messages at a higher level,
 502   // if there was an issue resolving or validating the nest host.
 503   // Returns null if there was no error.
 504   const char* nest_host_error();
 505   // Returns nest-host class, resolving and validating it if needed.
 506   // Returns null if resolution is not possible from the calling context.
 507   InstanceKlass* nest_host(TRAPS);
 508   // Check if this klass is a nestmate of k - resolves this nest-host and k's
 509   bool has_nestmate_access_to(InstanceKlass* k, TRAPS);
 510 
 511   // Called to verify that k is a permitted subclass of this class
 512   bool has_as_permitted_subclass(const InstanceKlass* k) const;
 513 
 514   enum InnerClassAttributeOffset {
 515     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 516     inner_class_inner_class_info_offset = 0,
 517     inner_class_outer_class_info_offset = 1,
 518     inner_class_inner_name_offset = 2,
 519     inner_class_access_flags_offset = 3,
 520     inner_class_next_offset = 4
 521   };
 522 
 523   enum EnclosingMethodAttributeOffset {
 524     enclosing_method_class_index_offset = 0,
 525     enclosing_method_method_index_offset = 1,
 526     enclosing_method_attribute_size = 2
 527   };
 528 
 529   // package
 530   PackageEntry* package() const     { return _package_entry; }
 531   ModuleEntry* module() const;
 532   bool in_unnamed_package() const   { return (_package_entry == nullptr); }
 533   void set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS);
 534   // If the package for the InstanceKlass is in the boot loader's package entry
 535   // table then sets the classpath_index field so that
 536   // get_system_package() will know to return a non-null value for the
 537   // package's location.  And, so that the package will be added to the list of
 538   // packages returned by get_system_packages().
 539   // For packages whose classes are loaded from the boot loader class path, the
 540   // classpath_index indicates which entry on the boot loader class path.
 541   void set_classpath_index(s2 path_index);
 542   bool is_same_class_package(const Klass* class2) const;
 543   bool is_same_class_package(oop other_class_loader, const Symbol* other_class_name) const;
 544 
 545   // find an enclosing class
 546   InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const;
 547 
 548   // Find InnerClasses attribute and return outer_class_info_index & inner_name_index.
 549   bool find_inner_classes_attr(int* ooff, int* noff, TRAPS) const;
 550 
 551  private:
 552   // Check prohibited package ("java/" only loadable by boot or platform loaders)
 553   static void check_prohibited_package(Symbol* class_name,
 554                                        ClassLoaderData* loader_data,
 555                                        TRAPS);
 556  public:
 557   // initialization state
 558   bool is_loaded() const                   { return init_state() >= loaded; }
 559   bool is_linked() const                   { return init_state() >= linked; }
 560   bool is_being_linked() const             { return init_state() == being_linked; }
 561   bool is_initialized() const              { return init_state() == fully_initialized; }
 562   bool is_not_initialized() const          { return init_state() <  being_initialized; }
 563   bool is_being_initialized() const        { return init_state() == being_initialized; }
 564   bool is_in_error_state() const           { return init_state() == initialization_error; }
 565   bool is_init_thread(JavaThread *thread)  { return thread == Atomic::load(&_init_thread); }
 566   ClassState  init_state() const           { return Atomic::load(&_init_state); }
 567   const char* init_state_name() const;
 568   bool is_rewritten() const                { return _misc_flags.rewritten(); }
 569 
 570   class LockLinkState : public StackObj {
 571     InstanceKlass* _ik;
 572     JavaThread*    _current;
 573    public:
 574     LockLinkState(InstanceKlass* ik, JavaThread* current) : _ik(ik), _current(current) {
 575       ik->check_link_state_and_wait(current);
 576     }
 577     ~LockLinkState() {
 578       if (!_ik->is_linked()) {
 579         // Reset to loaded if linking failed.
 580         _ik->set_initialization_state_and_notify(loaded, _current);
 581       }
 582     }
 583   };
 584 
 585   // is this a sealed class
 586   bool is_sealed() const;
 587 
 588   // defineClass specified verification
 589   bool should_verify_class() const         { return _misc_flags.should_verify_class(); }
 590   void set_should_verify_class(bool value) { _misc_flags.set_should_verify_class(value); }
 591 
 592   // marking
 593   bool is_marked_dependent() const         { return _misc_flags.is_marked_dependent(); }
 594   void set_is_marked_dependent(bool value) { _misc_flags.set_is_marked_dependent(value); }
 595 
 596   static ByteSize kind_offset() { return in_ByteSize(offset_of(InstanceKlass, _kind)); }
 597   static ByteSize misc_flags_offset() { return in_ByteSize(offset_of(InstanceKlass, _misc_flags)); }
 598 
 599   // initialization (virtuals from Klass)
 600   bool should_be_initialized() const;  // means that initialize should be called
 601   void initialize(TRAPS);
 602   void link_class(TRAPS);
 603   bool link_class_or_fail(TRAPS); // returns false on failure
 604   void rewrite_class(TRAPS);
 605   void link_methods(TRAPS);
 606   Method* class_initializer() const;
 607 
 608   // reference type
 609   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 610 
 611   // this class cp index
 612   u2 this_class_index() const             { return _this_class_index; }
 613   void set_this_class_index(u2 index)     { _this_class_index = index; }
 614 
 615   static ByteSize reference_type_offset() { return byte_offset_of(InstanceKlass, _reference_type); }
 616 
 617   // find local field, returns true if found
 618   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 619   // find field in direct superinterfaces, returns the interface in which the field is defined
 620   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 621   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 622   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 623   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 624   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 625 
 626   // find a non-static or static field given its offset within the class.
 627   bool contains_field_offset(int offset);
 628 
 629   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 630   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 631 
 632  private:
 633   inline static int quick_search(const Array<Method*>* methods, const Symbol* name);
 634 
 635  public:
 636   static void disable_method_binary_search() {
 637     _disable_method_binary_search = true;
 638   }
 639 
 640   // find a local method (returns null if not found)
 641   Method* find_method(const Symbol* name, const Symbol* signature) const;
 642   static Method* find_method(const Array<Method*>* methods,
 643                              const Symbol* name,
 644                              const Symbol* signature);
 645 
 646   // find a local method, but skip static methods
 647   Method* find_instance_method(const Symbol* name, const Symbol* signature,
 648                                PrivateLookupMode private_mode) const;
 649   static Method* find_instance_method(const Array<Method*>* methods,
 650                                       const Symbol* name,
 651                                       const Symbol* signature,
 652                                       PrivateLookupMode private_mode);
 653 
 654   // find a local method (returns null if not found)
 655   Method* find_local_method(const Symbol* name,
 656                             const Symbol* signature,
 657                             OverpassLookupMode overpass_mode,
 658                             StaticLookupMode static_mode,
 659                             PrivateLookupMode private_mode) const;
 660 
 661   // find a local method from given methods array (returns null if not found)
 662   static Method* find_local_method(const Array<Method*>* methods,
 663                                    const Symbol* name,
 664                                    const Symbol* signature,
 665                                    OverpassLookupMode overpass_mode,
 666                                    StaticLookupMode static_mode,
 667                                    PrivateLookupMode private_mode);
 668 
 669   // find a local method index in methods or default_methods (returns -1 if not found)
 670   static int find_method_index(const Array<Method*>* methods,
 671                                const Symbol* name,
 672                                const Symbol* signature,
 673                                OverpassLookupMode overpass_mode,
 674                                StaticLookupMode static_mode,
 675                                PrivateLookupMode private_mode);
 676 
 677   // lookup operation (returns null if not found)
 678   Method* uncached_lookup_method(const Symbol* name,
 679                                  const Symbol* signature,
 680                                  OverpassLookupMode overpass_mode,
 681                                  PrivateLookupMode private_mode = PrivateLookupMode::find) const;
 682 
 683   // lookup a method in all the interfaces that this class implements
 684   // (returns null if not found)
 685   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, DefaultsLookupMode defaults_mode) const;
 686 
 687   // lookup a method in local defaults then in all interfaces
 688   // (returns null if not found)
 689   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 690 
 691   // Find method indices by name.  If a method with the specified name is
 692   // found the index to the first method is returned, and 'end' is filled in
 693   // with the index of first non-name-matching method.  If no method is found
 694   // -1 is returned.
 695   int find_method_by_name(const Symbol* name, int* end) const;
 696   static int find_method_by_name(const Array<Method*>* methods,
 697                                  const Symbol* name, int* end);
 698 
 699   // constant pool
 700   ConstantPool* constants() const        { return _constants; }
 701   void set_constants(ConstantPool* c)    { _constants = c; }
 702 
 703   // protection domain
 704   oop protection_domain() const;
 705 
 706   // signers
 707   objArrayOop signers() const;
 708 
 709   bool is_contended() const                { return _misc_flags.is_contended(); }
 710   void set_is_contended(bool value)        { _misc_flags.set_is_contended(value); }
 711 
 712   // source file name
 713   Symbol* source_file_name() const;
 714   u2 source_file_name_index() const;
 715   void set_source_file_name_index(u2 sourcefile_index);
 716 
 717   // minor and major version numbers of class file
 718   u2 minor_version() const;
 719   void set_minor_version(u2 minor_version);
 720   u2 major_version() const;
 721   void set_major_version(u2 major_version);
 722 
 723   // source debug extension
 724   const char* source_debug_extension() const { return _source_debug_extension; }
 725   void set_source_debug_extension(const char* array, int length);
 726 
 727   // nonstatic oop-map blocks
 728   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 729     return oop_map_count * OopMapBlock::size_in_words();
 730   }
 731   unsigned int nonstatic_oop_map_count() const {
 732     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 733   }
 734   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 735   void set_nonstatic_oop_map_size(int words) {
 736     _nonstatic_oop_map_size = words;
 737   }
 738 
 739   bool has_contended_annotations() const { return _misc_flags.has_contended_annotations(); }
 740   void set_has_contended_annotations(bool value)  { _misc_flags.set_has_contended_annotations(value); }
 741 
 742 #if INCLUDE_JVMTI
 743   // Redefinition locking.  Class can only be redefined by one thread at a time.
 744   // The flag is in access_flags so that it can be set and reset using atomic
 745   // operations, and not be reset by other misc_flag settings.
 746   bool is_being_redefined() const          { return _misc_flags.is_being_redefined(); }
 747   void set_is_being_redefined(bool value)  { _misc_flags.set_is_being_redefined(value); }
 748 
 749   // RedefineClasses() support for previous versions:
 750   void add_previous_version(InstanceKlass* ik, int emcp_method_count);
 751   void purge_previous_version_list();
 752 
 753   InstanceKlass* previous_versions() const { return _previous_versions; }
 754 #else
 755   InstanceKlass* previous_versions() const { return nullptr; }
 756 #endif
 757 
 758   InstanceKlass* get_klass_version(int version);
 759 
 760   bool has_been_redefined() const { return _misc_flags.has_been_redefined(); }
 761   void set_has_been_redefined() { _misc_flags.set_has_been_redefined(true); }
 762 
 763   bool is_scratch_class() const { return _misc_flags.is_scratch_class(); }
 764   void set_is_scratch_class() { _misc_flags.set_is_scratch_class(true); }
 765 
 766   bool has_resolved_methods() const { return _misc_flags.has_resolved_methods(); }
 767   void set_has_resolved_methods()   { _misc_flags.set_has_resolved_methods(true); }
 768   void set_has_resolved_methods(bool value)   { _misc_flags.set_has_resolved_methods(value); }
 769 
 770 public:
 771 #if INCLUDE_JVMTI
 772 
 773   void init_previous_versions() {
 774     _previous_versions = nullptr;
 775   }
 776 
 777  private:
 778   static bool  _should_clean_previous_versions;
 779  public:
 780   static void purge_previous_versions(InstanceKlass* ik) {
 781     if (ik->has_been_redefined()) {
 782       ik->purge_previous_version_list();
 783     }
 784   }
 785 
 786   static bool should_clean_previous_versions_and_reset();
 787   static bool should_clean_previous_versions() { return _should_clean_previous_versions; }
 788 
 789   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 790   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 791     _cached_class_file = data;
 792   }
 793   JvmtiCachedClassFileData * get_cached_class_file();
 794   jint get_cached_class_file_len();
 795   unsigned char * get_cached_class_file_bytes();
 796 
 797   // JVMTI: Support for caching of field indices, types, and offsets
 798   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 799     _jvmti_cached_class_field_map = descriptor;
 800   }
 801   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 802     return _jvmti_cached_class_field_map;
 803   }
 804 #else // INCLUDE_JVMTI
 805 
 806   static void purge_previous_versions(InstanceKlass* ik) { return; };
 807   static bool should_clean_previous_versions_and_reset() { return false; }
 808 
 809   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 810     assert(data == nullptr, "unexpected call with JVMTI disabled");
 811   }
 812   JvmtiCachedClassFileData * get_cached_class_file() { return (JvmtiCachedClassFileData *)nullptr; }
 813 
 814 #endif // INCLUDE_JVMTI
 815 
 816   bool has_nonstatic_concrete_methods() const { return _misc_flags.has_nonstatic_concrete_methods(); }
 817   void set_has_nonstatic_concrete_methods(bool b) { _misc_flags.set_has_nonstatic_concrete_methods(b); }
 818 
 819   bool declares_nonstatic_concrete_methods() const { return _misc_flags.declares_nonstatic_concrete_methods(); }
 820   void set_declares_nonstatic_concrete_methods(bool b) { _misc_flags.set_declares_nonstatic_concrete_methods(b); }
 821 
 822   bool has_vanilla_constructor() const  { return _misc_flags.has_vanilla_constructor(); }
 823   void set_has_vanilla_constructor()    { _misc_flags.set_has_vanilla_constructor(true); }
 824   bool has_miranda_methods () const     { return _misc_flags.has_miranda_methods(); }
 825   void set_has_miranda_methods()        { _misc_flags.set_has_miranda_methods(true); }
 826   bool has_final_method() const         { return _misc_flags.has_final_method(); }
 827   void set_has_final_method()           { _misc_flags.set_has_final_method(true); }
 828 
 829   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 830   inline u2 next_method_idnum();
 831   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 832 
 833   // generics support
 834   Symbol* generic_signature() const;
 835   u2 generic_signature_index() const;
 836   void set_generic_signature_index(u2 sig_index);
 837 
 838   u2 enclosing_method_data(int offset) const;
 839   u2 enclosing_method_class_index() const {
 840     return enclosing_method_data(enclosing_method_class_index_offset);
 841   }
 842   u2 enclosing_method_method_index() {
 843     return enclosing_method_data(enclosing_method_method_index_offset);
 844   }
 845   void set_enclosing_method_indices(u2 class_index,
 846                                     u2 method_index);
 847 
 848   // jmethodID support
 849   jmethodID get_jmethod_id(const methodHandle& method_h);
 850   jmethodID get_jmethod_id_fetch_or_update(size_t idnum,
 851                      jmethodID new_id, jmethodID* new_jmeths,
 852                      jmethodID* to_dealloc_id_p,
 853                      jmethodID** to_dealloc_jmeths_p);
 854   static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
 855                 size_t *length_p, jmethodID* id_p);
 856   void ensure_space_for_methodids(int start_offset = 0);
 857   jmethodID jmethod_id_or_null(Method* method);
 858 
 859   // annotations support
 860   Annotations* annotations() const          { return _annotations; }
 861   void set_annotations(Annotations* anno)   { _annotations = anno; }
 862 
 863   AnnotationArray* class_annotations() const {
 864     return (_annotations != nullptr) ? _annotations->class_annotations() : nullptr;
 865   }
 866   Array<AnnotationArray*>* fields_annotations() const {
 867     return (_annotations != nullptr) ? _annotations->fields_annotations() : nullptr;
 868   }
 869   AnnotationArray* class_type_annotations() const {
 870     return (_annotations != nullptr) ? _annotations->class_type_annotations() : nullptr;
 871   }
 872   Array<AnnotationArray*>* fields_type_annotations() const {
 873     return (_annotations != nullptr) ? _annotations->fields_type_annotations() : nullptr;
 874   }
 875   // allocation
 876   instanceOop allocate_instance(TRAPS);
 877   static instanceOop allocate_instance(oop cls, TRAPS);
 878 
 879   // additional member function to return a handle
 880   instanceHandle allocate_instance_handle(TRAPS);
 881 
 882   objArrayOop allocate_objArray(int n, int length, TRAPS);
 883   // Helper function
 884   static instanceOop register_finalizer(instanceOop i, TRAPS);
 885 
 886   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 887   // if not, throw either an Error or an Exception.
 888   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 889 
 890   // initialization
 891   void call_class_initializer(TRAPS);
 892   void set_initialization_state_and_notify(ClassState state, JavaThread* current);
 893 
 894   // OopMapCache support
 895   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 896   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 897   void mask_for(const methodHandle& method, int bci, InterpreterOopMap* entry);
 898 
 899   // JNI identifier support (for static fields - for jni performance)
 900   JNIid* jni_ids()                               { return _jni_ids; }
 901   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 902   JNIid* jni_id_for(int offset);
 903 
 904   // maintenance of deoptimization dependencies
 905   inline DependencyContext dependencies();
 906   void mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes);
 907   void add_dependent_nmethod(nmethod* nm);
 908   void clean_dependency_context();
 909   // Setup link to hierarchy and deoptimize
 910   void add_to_hierarchy(JavaThread* current);
 911 
 912   // On-stack replacement support
 913   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 914   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 915   void add_osr_nmethod(nmethod* n);
 916   bool remove_osr_nmethod(nmethod* n);
 917   int mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m);
 918   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 919 
 920 #if INCLUDE_JVMTI
 921   // Breakpoint support (see methods on Method* for details)
 922   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 923   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 924 #endif
 925 
 926   // support for stub routines
 927   static ByteSize init_state_offset()  { return byte_offset_of(InstanceKlass, _init_state); }
 928   JFR_ONLY(DEFINE_KLASS_TRACE_ID_OFFSET;)
 929   static ByteSize init_thread_offset() { return byte_offset_of(InstanceKlass, _init_thread); }
 930 
 931   static ByteSize inline_type_field_klasses_offset() { return in_ByteSize(offset_of(InstanceKlass, _inline_type_field_klasses)); }
 932   static ByteSize adr_inlineklass_fixed_block_offset() { return in_ByteSize(offset_of(InstanceKlass, _adr_inlineklass_fixed_block)); }
 933 
 934   // subclass/subinterface checks
 935   bool implements_interface(Klass* k) const;
 936   bool is_same_or_direct_interface(Klass* k) const;
 937 
 938 #ifdef ASSERT
 939   // check whether this class or one of its superclasses was redefined
 940   bool has_redefined_this_or_super() const;
 941 #endif
 942 
 943   // Access to the implementor of an interface.
 944   InstanceKlass* implementor() const;
 945   void set_implementor(InstanceKlass* ik);
 946   int  nof_implementors() const;
 947   void add_implementor(InstanceKlass* ik);  // ik is a new class that implements this interface
 948   void init_implementor();           // initialize
 949 
 950  private:
 951   // link this class into the implementors list of every interface it implements
 952   void process_interfaces();
 953 
 954  public:
 955   // virtual operations from Klass
 956   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
 957                                                   Array<InstanceKlass*>* transitive_interfaces);
 958   bool can_be_primary_super_slow() const;
 959   size_t oop_size(oop obj)  const             { return size_helper(); }
 960   // slow because it's a virtual call and used for verifying the layout_helper.
 961   // Using the layout_helper bits, we can call is_instance_klass without a virtual call.
 962   DEBUG_ONLY(bool is_instance_klass_slow() const      { return true; })
 963 
 964   // Iterators
 965   void do_local_static_fields(FieldClosure* cl);
 966   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
 967   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
 968   void print_nonstatic_fields(FieldClosure* cl); // including inherited and injected fields
 969 
 970   void methods_do(void f(Method* method));
 971 
 972   static InstanceKlass* cast(Klass* k) {
 973     return const_cast<InstanceKlass*>(cast(const_cast<const Klass*>(k)));
 974   }
 975 
 976   static const InstanceKlass* cast(const Klass* k) {
 977     assert(k != nullptr, "k should not be null");
 978     assert(k->is_instance_klass(), "cast to InstanceKlass");
 979     return static_cast<const InstanceKlass*>(k);
 980   }
 981 
 982   virtual InstanceKlass* java_super() const {
 983     return (super() == nullptr) ? nullptr : cast(super());
 984   }
 985 
 986   // Sizing (in words)
 987   static int header_size()            { return sizeof(InstanceKlass)/wordSize; }
 988 
 989   static int size(int vtable_length, int itable_length,
 990                   int nonstatic_oop_map_size,
 991                   bool is_interface,
 992                   int java_fields, bool is_inline_type) {
 993     return align_metadata_size(header_size() +
 994            vtable_length +
 995            itable_length +
 996            nonstatic_oop_map_size +
 997            (is_interface ? (int)sizeof(Klass*)/wordSize : 0) +
 998            (java_fields * (int)sizeof(Klass*)/wordSize) +
 999            (is_inline_type ? (int)sizeof(InlineKlassFixedBlock) : 0));
1000   }
1001 
1002   int size() const                    { return size(vtable_length(),
1003                                                itable_length(),
1004                                                nonstatic_oop_map_size(),
1005                                                is_interface(),
1006                                                has_inline_type_fields() ? java_fields_count() : 0,
1007                                                is_inline_klass());
1008   }
1009 
1010 
1011   inline intptr_t* start_of_itable() const;
1012   inline intptr_t* end_of_itable() const;
1013   inline oop static_field_base_raw();
1014   bool bounds_check(address addr, bool edge_ok = false, intptr_t size_in_bytes = -1) const PRODUCT_RETURN0;
1015 
1016   inline OopMapBlock* start_of_nonstatic_oop_maps() const;
1017   inline Klass** end_of_nonstatic_oop_maps() const;
1018 
1019   inline InstanceKlass* volatile* adr_implementor() const;
1020 
1021   inline address adr_inline_type_field_klasses() const;
1022   inline Klass* get_inline_type_field_klass(int idx) const;
1023   inline Klass* get_inline_type_field_klass_or_null(int idx) const;
1024   inline void set_inline_type_field_klass(int idx, Klass* k);
1025   inline void reset_inline_type_field_klass(int idx);
1026 
1027   // Use this to return the size of an instance in heap words:
1028   virtual int size_helper() const {
1029     return layout_helper_to_size_helper(layout_helper());
1030   }
1031 
1032   // This bit is initialized in classFileParser.cpp.
1033   // It is false under any of the following conditions:
1034   //  - the class is abstract (including any interface)
1035   //  - the class has a finalizer (if !RegisterFinalizersAtInit)
1036   //  - the class size is larger than FastAllocateSizeLimit
1037   //  - the class is java/lang/Class, which cannot be allocated directly
1038   bool can_be_fastpath_allocated() const {
1039     return !layout_helper_needs_slow_path(layout_helper());
1040   }
1041 
1042   // Java itable
1043   klassItable itable() const;        // return klassItable wrapper
1044   Method* method_at_itable(InstanceKlass* holder, int index, TRAPS);
1045   Method* method_at_itable_or_null(InstanceKlass* holder, int index, bool& itable_entry_found);
1046   int vtable_index_of_interface_method(Method* method);
1047 
1048 #if INCLUDE_JVMTI
1049   void adjust_default_methods(bool* trace_name_printed);
1050 #endif // INCLUDE_JVMTI
1051 
1052   void clean_weak_instanceklass_links();
1053  private:
1054   void clean_implementors_list();
1055   void clean_method_data();
1056 
1057  public:
1058   // Explicit metaspace deallocation of fields
1059   // For RedefineClasses and class file parsing errors, we need to deallocate
1060   // instanceKlasses and the metadata they point to.
1061   void deallocate_contents(ClassLoaderData* loader_data);
1062   static void deallocate_methods(ClassLoaderData* loader_data,
1063                                  Array<Method*>* methods);
1064   void static deallocate_interfaces(ClassLoaderData* loader_data,
1065                                     const Klass* super_klass,
1066                                     Array<InstanceKlass*>* local_interfaces,
1067                                     Array<InstanceKlass*>* transitive_interfaces);
1068   void static deallocate_record_components(ClassLoaderData* loader_data,
1069                                            Array<RecordComponent*>* record_component);
1070 
1071   virtual bool on_stack() const;
1072 
1073   // callbacks for actions during class unloading
1074   static void unload_class(InstanceKlass* ik);
1075 
1076   virtual void release_C_heap_structures(bool release_sub_metadata = true);
1077 
1078   // Naming
1079   const char* signature_name() const;
1080   const char* signature_name_of_carrier(char c) const;
1081 
1082   // Oop fields (and metadata) iterators
1083   //
1084   // The InstanceKlass iterators also visits the Object's klass.
1085 
1086   // Forward iteration
1087  public:
1088   // Iterate over all oop fields in the oop maps.
1089   template <typename T, class OopClosureType>
1090   inline void oop_oop_iterate_oop_maps(oop obj, OopClosureType* closure);
1091 
1092   // Iterate over all oop fields and metadata.
1093   template <typename T, class OopClosureType>
1094   inline void oop_oop_iterate(oop obj, OopClosureType* closure);
1095 
1096   // Iterate over all oop fields in one oop map.
1097   template <typename T, class OopClosureType>
1098   inline void oop_oop_iterate_oop_map(OopMapBlock* map, oop obj, OopClosureType* closure);
1099 
1100 
1101   // Reverse iteration
1102   // Iterate over all oop fields and metadata.
1103   template <typename T, class OopClosureType>
1104   inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
1105 
1106  private:
1107   // Iterate over all oop fields in the oop maps.
1108   template <typename T, class OopClosureType>
1109   inline void oop_oop_iterate_oop_maps_reverse(oop obj, OopClosureType* closure);
1110 
1111   // Iterate over all oop fields in one oop map.
1112   template <typename T, class OopClosureType>
1113   inline void oop_oop_iterate_oop_map_reverse(OopMapBlock* map, oop obj, OopClosureType* closure);
1114 
1115 
1116   // Bounded range iteration
1117  public:
1118   // Iterate over all oop fields in the oop maps.
1119   template <typename T, class OopClosureType>
1120   inline void oop_oop_iterate_oop_maps_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1121 
1122   // Iterate over all oop fields and metadata.
1123   template <typename T, class OopClosureType>
1124   inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1125 
1126  private:
1127   // Iterate over all oop fields in one oop map.
1128   template <typename T, class OopClosureType>
1129   inline void oop_oop_iterate_oop_map_bounded(OopMapBlock* map, oop obj, OopClosureType* closure, MemRegion mr);
1130 
1131 
1132  public:
1133   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
1134 
1135  private:
1136   // initialization state
1137   void set_init_state(ClassState state);
1138   void set_rewritten()                  { _misc_flags.set_rewritten(true); }
1139   void set_init_thread(JavaThread *thread)  {
1140     assert((thread == JavaThread::current() && _init_thread == nullptr) ||
1141            (thread == nullptr && _init_thread == JavaThread::current()), "Only one thread is allowed to own initialization");
1142     Atomic::store(&_init_thread, thread);
1143   }
1144 
1145   // The RedefineClasses() API can cause new method idnums to be needed
1146   // which will cause the caches to grow. Safety requires different
1147   // cache management logic if the caches can grow instead of just
1148   // going from null to non-null.
1149   bool idnum_can_increment() const      { return has_been_redefined(); }
1150   inline jmethodID* methods_jmethod_ids_acquire() const;
1151   inline void release_set_methods_jmethod_ids(jmethodID* jmeths);
1152 
1153   // Lock during initialization
1154 public:
1155   // Returns the array class for the n'th dimension
1156   virtual Klass* array_klass(int n, TRAPS);
1157   virtual Klass* array_klass_or_null(int n);
1158 
1159   // Returns the array class with this class as element type
1160   virtual Klass* array_klass(TRAPS);
1161   virtual Klass* array_klass_or_null();
1162 
1163   static void clean_initialization_error_table();
1164 
1165   Monitor* init_monitor() const { return _init_monitor; }
1166 private:
1167   void check_link_state_and_wait(JavaThread* current);
1168   bool link_class_impl                           (TRAPS);
1169   bool verify_code                               (TRAPS);
1170   void initialize_impl                           (TRAPS);
1171   void initialize_super_interfaces               (TRAPS);
1172 
1173   void add_initialization_error(JavaThread* current, Handle exception);
1174   oop get_initialization_error(JavaThread* current);
1175 
1176   // find a local method (returns null if not found)
1177   Method* find_method_impl(const Symbol* name,
1178                            const Symbol* signature,
1179                            OverpassLookupMode overpass_mode,
1180                            StaticLookupMode static_mode,
1181                            PrivateLookupMode private_mode) const;
1182 
1183   static Method* find_method_impl(const Array<Method*>* methods,
1184                                   const Symbol* name,
1185                                   const Symbol* signature,
1186                                   OverpassLookupMode overpass_mode,
1187                                   StaticLookupMode static_mode,
1188                                   PrivateLookupMode private_mode);
1189 
1190 #if INCLUDE_JVMTI
1191   // RedefineClasses support
1192   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1193   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1194 #endif
1195   // log class name to classlist
1196   void log_to_classlist() const;
1197 public:
1198 
1199 #if INCLUDE_CDS
1200   // CDS support - remove and restore oops from metadata. Oops are not shared.
1201   virtual void remove_unshareable_info();
1202   void remove_unshareable_flags();
1203   virtual void remove_java_mirror();
1204   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
1205   void init_shared_package_entry();
1206   bool can_be_verified_at_dumptime() const;
1207   bool methods_contain_jsr_bytecode() const;
1208   void compute_has_loops_flag_for_methods();
1209 #endif
1210 
1211   jint compute_modifier_flags() const;
1212 
1213 public:
1214   // JVMTI support
1215   jint jvmti_class_status() const;
1216 
1217   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
1218 
1219  public:
1220   // Printing
1221   void print_on(outputStream* st) const;
1222   void print_value_on(outputStream* st) const;
1223 
1224   void oop_print_value_on(oop obj, outputStream* st);
1225 
1226   void oop_print_on      (oop obj, outputStream* st);
1227 
1228 #ifndef PRODUCT
1229   void print_dependent_nmethods(bool verbose = false);
1230   bool is_dependent_nmethod(nmethod* nm);
1231   bool verify_itable_index(int index);
1232 #endif
1233 
1234   const char* internal_name() const;
1235 
1236   // Verification
1237   void verify_on(outputStream* st);
1238 
1239   void oop_verify_on(oop obj, outputStream* st);
1240 
1241   // Logging
1242   void print_class_load_logging(ClassLoaderData* loader_data,
1243                                 const ModuleEntry* module_entry,
1244                                 const ClassFileStream* cfs) const;
1245  private:
1246   void print_class_load_cause_logging() const;
1247   void print_class_load_helper(ClassLoaderData* loader_data,
1248                                const ModuleEntry* module_entry,
1249                                const ClassFileStream* cfs) const;
1250 };
1251 
1252 // for adding methods
1253 // UNSET_IDNUM return means no more ids available
1254 inline u2 InstanceKlass::next_method_idnum() {
1255   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1256     return ConstMethod::UNSET_IDNUM; // no more ids available
1257   } else {
1258     return _idnum_allocated_count++;
1259   }
1260 }
1261 
1262 class PrintClassClosure : public KlassClosure {
1263 private:
1264   outputStream* _st;
1265   bool _verbose;
1266 public:
1267   PrintClassClosure(outputStream* st, bool verbose);
1268 
1269   void do_klass(Klass* k);
1270 };
1271 
1272 /* JNIid class for jfieldIDs only */
1273 class JNIid: public CHeapObj<mtClass> {
1274   friend class VMStructs;
1275  private:
1276   Klass*             _holder;
1277   JNIid*             _next;
1278   int                _offset;
1279 #ifdef ASSERT
1280   bool               _is_static_field_id;
1281 #endif
1282 
1283  public:
1284   // Accessors
1285   Klass* holder() const           { return _holder; }
1286   int offset() const              { return _offset; }
1287   JNIid* next()                   { return _next; }
1288   // Constructor
1289   JNIid(Klass* holder, int offset, JNIid* next);
1290   // Identifier lookup
1291   JNIid* find(int offset);
1292 
1293   bool find_local_field(fieldDescriptor* fd) {
1294     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1295   }
1296 
1297   static void deallocate(JNIid* id);
1298   // Debugging
1299 #ifdef ASSERT
1300   bool is_static_field_id() const { return _is_static_field_id; }
1301   void set_is_static_field_id()   { _is_static_field_id = true; }
1302 #endif
1303   void verify(Klass* holder);
1304 };
1305 
1306 // An iterator that's used to access the inner classes indices in the
1307 // InstanceKlass::_inner_classes array.
1308 class InnerClassesIterator : public StackObj {
1309  private:
1310   Array<jushort>* _inner_classes;
1311   int _length;
1312   int _idx;
1313  public:
1314 
1315   InnerClassesIterator(const InstanceKlass* k) {
1316     _inner_classes = k->inner_classes();
1317     if (k->inner_classes() != nullptr) {
1318       _length = _inner_classes->length();
1319       // The inner class array's length should be the multiple of
1320       // inner_class_next_offset if it only contains the InnerClasses
1321       // attribute data, or it should be
1322       // n*inner_class_next_offset+enclosing_method_attribute_size
1323       // if it also contains the EnclosingMethod data.
1324       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1325               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1326              "just checking");
1327       // Remove the enclosing_method portion if exists.
1328       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1329         _length -= InstanceKlass::enclosing_method_attribute_size;
1330       }
1331     } else {
1332       _length = 0;
1333     }
1334     _idx = 0;
1335   }
1336 
1337   int length() const {
1338     return _length;
1339   }
1340 
1341   void next() {
1342     _idx += InstanceKlass::inner_class_next_offset;
1343   }
1344 
1345   bool done() const {
1346     return (_idx >= _length);
1347   }
1348 
1349   u2 inner_class_info_index() const {
1350     return _inner_classes->at(
1351                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1352   }
1353 
1354   void set_inner_class_info_index(u2 index) {
1355     _inner_classes->at_put(
1356                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1357   }
1358 
1359   u2 outer_class_info_index() const {
1360     return _inner_classes->at(
1361                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1362   }
1363 
1364   void set_outer_class_info_index(u2 index) {
1365     _inner_classes->at_put(
1366                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1367   }
1368 
1369   u2 inner_name_index() const {
1370     return _inner_classes->at(
1371                _idx + InstanceKlass::inner_class_inner_name_offset);
1372   }
1373 
1374   void set_inner_name_index(u2 index) {
1375     _inner_classes->at_put(
1376                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1377   }
1378 
1379   u2 inner_access_flags() const {
1380     return _inner_classes->at(
1381                _idx + InstanceKlass::inner_class_access_flags_offset);
1382   }
1383 };
1384 
1385 // Iterator over class hierarchy under a particular class. Implements depth-first pre-order traversal.
1386 // Usage:
1387 //  for (ClassHierarchyIterator iter(root_klass); !iter.done(); iter.next()) {
1388 //    Klass* k = iter.klass();
1389 //    ...
1390 //  }
1391 class ClassHierarchyIterator : public StackObj {
1392  private:
1393   InstanceKlass* _root;
1394   Klass*         _current;
1395   bool           _visit_subclasses;
1396 
1397  public:
1398   ClassHierarchyIterator(InstanceKlass* root) : _root(root), _current(root), _visit_subclasses(true) {
1399     assert(_root == _current, "required"); // initial state
1400   }
1401 
1402   bool done() {
1403     return (_current == nullptr);
1404   }
1405 
1406   // Make a step iterating over the class hierarchy under the root class.
1407   // Skips subclasses if requested.
1408   void next();
1409 
1410   Klass* klass() {
1411     assert(!done(), "sanity");
1412     return _current;
1413   }
1414 
1415   // Skip subclasses of the current class.
1416   void skip_subclasses() {
1417     _visit_subclasses = false;
1418   }
1419 };
1420 
1421 #endif // SHARE_OOPS_INSTANCEKLASS_HPP