1 /*
   2  * Copyright (c) 1997, 2025, 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/allocation.hpp"
  30 #include "memory/referenceType.hpp"
  31 #include "oops/annotations.hpp"
  32 #include "oops/constMethod.hpp"
  33 #include "oops/fieldInfo.hpp"
  34 #include "oops/instanceKlassFlags.hpp"
  35 #include "oops/instanceOop.hpp"
  36 #include "oops/refArrayKlass.hpp"
  37 #include "runtime/handles.hpp"
  38 #include "runtime/javaThread.hpp"
  39 #include "utilities/accessFlags.hpp"
  40 #include "utilities/align.hpp"
  41 #include "utilities/growableArray.hpp"
  42 #include "utilities/macros.hpp"
  43 #if INCLUDE_JFR
  44 #include "jfr/support/jfrKlassExtension.hpp"
  45 #endif
  46 
  47 class ConstantPool;
  48 class DeoptimizationScope;
  49 class klassItable;
  50 class RecordComponent;
  51 
  52 // An InstanceKlass is the VM level representation of a Java class.
  53 // It contains all information needed for at class at execution runtime.
  54 
  55 //  InstanceKlass embedded field layout (after declared fields):
  56 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  57 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  58 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  59 //      indicating where oops are located in instances of this klass.
  60 //    [EMBEDDED implementor of the interface] only exist for interface
  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 JNIid;
  74 class JvmtiCachedClassFieldMap;
  75 class nmethodBucket;
  76 class OopMapCache;
  77 class BufferedInlineTypeBlob;
  78 class InterpreterOopMap;
  79 class PackageEntry;
  80 class ModuleEntry;
  81 
  82 // This is used in iterators below.
  83 class FieldClosure: public StackObj {
  84 public:
  85   virtual void do_field(fieldDescriptor* fd) = 0;
  86 };
  87 
  88 // Print fields.
  89 // If "obj" argument to constructor is null, prints static fields, otherwise prints non-static fields.
  90 class FieldPrinter: public FieldClosure {
  91    oop _obj;
  92    outputStream* _st;
  93    int _indent;
  94    int _base_offset;
  95  public:
  96    FieldPrinter(outputStream* st, oop obj = nullptr, int indent = 0, int base_offset = 0) :
  97                  _obj(obj), _st(st), _indent(indent), _base_offset(base_offset) {}
  98    void do_field(fieldDescriptor* fd);
  99 };
 100 
 101 // Describes where oops are located in instances of this klass.
 102 class OopMapBlock {
 103  public:
 104   // Byte offset of the first oop mapped by this block.
 105   int offset() const          { return _offset; }
 106   void set_offset(int offset) { _offset = offset; }
 107 
 108   // Number of oops in this block.
 109   uint count() const         { return _count; }
 110   void set_count(uint count) { _count = count; }
 111 
 112   void increment_count(int diff) { _count += diff; }
 113 
 114   int offset_span() const { return _count * heapOopSize; }
 115 
 116   int end_offset() const {
 117     return offset() + offset_span();
 118   }
 119 
 120   bool is_contiguous(int another_offset) const {
 121     return another_offset == end_offset();
 122   }
 123 
 124   // sizeof(OopMapBlock) in words.
 125   static int size_in_words() {
 126     return align_up((int)sizeof(OopMapBlock), wordSize) >>
 127       LogBytesPerWord;
 128   }
 129 
 130   static int compare_offset(const OopMapBlock* a, const OopMapBlock* b) {
 131     return a->offset() - b->offset();
 132   }
 133 
 134  private:
 135   int  _offset;
 136   uint _count;
 137 };
 138 
 139 struct JvmtiCachedClassFileData;
 140 
 141 class SigEntry;
 142 
 143 class InlineKlassFixedBlock {
 144   Array<SigEntry>** _extended_sig;
 145   Array<VMRegPair>** _return_regs;
 146   address* _pack_handler;
 147   address* _pack_handler_jobject;
 148   address* _unpack_handler;
 149   int* _null_reset_value_offset;
 150   int _payload_offset;          // offset of the begining of the payload in a heap buffered instance
 151   int _payload_size_in_bytes;   // size of payload layout
 152   int _payload_alignment;       // alignment required for payload
 153   int _non_atomic_size_in_bytes; // size of null-free non-atomic flat layout
 154   int _non_atomic_alignment;    // alignment requirement for null-free non-atomic layout
 155   int _atomic_size_in_bytes;    // size and alignment requirement for a null-free atomic layout, -1 if no atomic flat layout is possible
 156   int _nullable_size_in_bytes;  // size and alignment requirement for a nullable layout (always atomic), -1 if no nullable flat layout is possible
 157   int _null_marker_offset;      // expressed as an offset from the beginning of the object for a heap buffered value
 158                                 // payload_offset must be subtracted to get the offset from the beginning of the payload
 159 
 160   friend class InlineKlass;
 161 };
 162 
 163 class InlineLayoutInfo : public MetaspaceObj {
 164   InlineKlass* _klass;
 165   LayoutKind _kind;
 166   int _null_marker_offset; // null marker offset for this field, relative to the beginning of the current container
 167 
 168  public:
 169   InlineLayoutInfo(): _klass(nullptr), _kind(LayoutKind::UNKNOWN), _null_marker_offset(-1)  {}
 170   InlineLayoutInfo(InlineKlass* ik, LayoutKind kind, int size, int nm_offset):
 171     _klass(ik), _kind(kind), _null_marker_offset(nm_offset) {}
 172 
 173   InlineKlass* klass() const { return _klass; }
 174   void set_klass(InlineKlass* k) { _klass = k; }
 175 
 176   LayoutKind kind() const {
 177     assert(_kind != LayoutKind::UNKNOWN, "Not set");
 178     return _kind;
 179   }
 180   void set_kind(LayoutKind lk) { _kind = lk; }
 181 
 182   int null_marker_offset() const {
 183     assert(_null_marker_offset != -1, "Not set");
 184     return _null_marker_offset;
 185   }
 186   void set_null_marker_offset(int o) { _null_marker_offset = o; }
 187 
 188   void metaspace_pointers_do(MetaspaceClosure* it);
 189   MetaspaceObj::Type type() const { return InlineLayoutInfoType; }
 190 
 191   static ByteSize klass_offset() { return in_ByteSize(offset_of(InlineLayoutInfo, _klass)); }
 192   static ByteSize null_marker_offset_offset() { return in_ByteSize(offset_of(InlineLayoutInfo, _null_marker_offset)); }
 193 };
 194 
 195 class InstanceKlass: public Klass {
 196   friend class VMStructs;
 197   friend class JVMCIVMStructs;
 198   friend class ClassFileParser;
 199   friend class CompileReplay;
 200   friend class TemplateTable;
 201 
 202  public:
 203   static const KlassKind Kind = InstanceKlassKind;
 204 
 205  protected:
 206   InstanceKlass(const ClassFileParser& parser, KlassKind kind = Kind, markWord prototype = markWord::prototype(), ReferenceType reference_type = REF_NONE);
 207 
 208  public:
 209   InstanceKlass();
 210 
 211   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 212   // of the class loading & initialization procedure, and the use of the states.
 213   enum ClassState : u1 {
 214     allocated,                          // allocated (but not yet linked)
 215     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 216     linked,                             // successfully linked/verified (but not initialized yet)
 217     being_initialized,                  // currently running class initializer
 218     fully_initialized,                  // initialized (successful final state)
 219     initialization_error                // error happened during initialization
 220   };
 221 
 222  private:
 223   static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);
 224 
 225  protected:
 226   // If you add a new field that points to any metaspace object, you
 227   // must add this field to InstanceKlass::metaspace_pointers_do().
 228 
 229   // Annotations for this class
 230   Annotations*    _annotations;
 231   // Package this class is defined in
 232   PackageEntry*   _package_entry;
 233   // Array classes holding elements of this class.
 234   ObjArrayKlass* volatile _array_klasses;
 235   // Constant pool for this class.
 236   ConstantPool* _constants;
 237   // The InnerClasses attribute and EnclosingMethod attribute. The
 238   // _inner_classes is an array of shorts. If the class has InnerClasses
 239   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 240   // [inner_class_info_index, outer_class_info_index,
 241   // inner_name_index, inner_class_access_flags] for the InnerClasses
 242   // attribute. If the EnclosingMethod attribute exists, it occupies the
 243   // last two shorts [class_index, method_index] of the array. If only
 244   // the InnerClasses attribute exists, the _inner_classes array length is
 245   // number_of_inner_classes * 4. If the class has both InnerClasses
 246   // and EnclosingMethod attributes the _inner_classes array length is
 247   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 248   Array<jushort>* _inner_classes;
 249 
 250   // The NestMembers attribute. An array of shorts, where each is a
 251   // class info index for the class that is a nest member. This data
 252   // has not been validated.
 253   Array<jushort>* _nest_members;
 254 
 255   // Resolved nest-host klass: either true nest-host or self if we are not
 256   // nested, or an error occurred resolving or validating the nominated
 257   // nest-host. Can also be set directly by JDK API's that establish nest
 258   // relationships.
 259   // By always being set it makes nest-member access checks simpler.
 260   InstanceKlass* _nest_host;
 261 
 262   // The PermittedSubclasses attribute. An array of shorts, where each is a
 263   // class info index for the class that is a permitted subclass.
 264   Array<jushort>* _permitted_subclasses;
 265 
 266   // The contents of the Record attribute.
 267   Array<RecordComponent*>* _record_components;
 268 
 269   // the source debug extension for this klass, null if not specified.
 270   // Specified as UTF-8 string without terminating zero byte in the classfile,
 271   // it is stored in the instanceklass as a null-terminated UTF-8 string
 272   const char*     _source_debug_extension;
 273 
 274   // Number of heapOopSize words used by non-static fields in this klass
 275   // (including inherited fields but after header_size()).
 276   int             _nonstatic_field_size;
 277   int             _static_field_size;       // number words used by static fields (oop and non-oop) in this klass
 278   int             _nonstatic_oop_map_size;  // size in words of nonstatic oop map blocks
 279   int             _itable_len;              // length of Java itable (in words)
 280 
 281   // The NestHost attribute. The class info index for the class
 282   // that is the nest-host of this class. This data has not been validated.
 283   u2              _nest_host_index;
 284   u2              _this_class_index;        // constant pool entry
 285   u2              _static_oop_field_count;  // number of static oop fields in this klass
 286 
 287   volatile u2     _idnum_allocated_count;   // JNI/JVMTI: increments with the addition of methods, old ids don't change
 288 
 289   // Class states are defined as ClassState (see above).
 290   // Place the _init_state here to utilize the unused 2-byte after
 291   // _idnum_allocated_count.
 292   volatile ClassState _init_state;          // state of class
 293 
 294   u1              _reference_type;                // reference type
 295   int             _acmp_maps_offset;        // offset to injected static field storing acmp_maps for values classes
 296                                             // unfortunately, abstract values need one too so it cannot be stored in
 297                                             // the InlineKlassFixedBlock that only exist for InlineKlass.
 298 
 299   // State is set either at parse time or while executing, atomically to not disturb other state
 300   InstanceKlassFlags _misc_flags;
 301 
 302   JavaThread* volatile _init_thread;        // Pointer to current thread doing initialization (to handle recursive initialization)
 303 
 304   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 305   JNIid*          _jni_ids;                  // First JNI identifier for static fields in this class
 306   jmethodID* volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or null if none
 307   nmethodBucket*  volatile _dep_context;     // packed DependencyContext structure
 308   uint64_t        volatile _dep_context_last_cleaned;
 309   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 310 #if INCLUDE_JVMTI
 311   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 312   // Linked instanceKlasses of previous versions
 313   InstanceKlass* _previous_versions;
 314   // JVMTI fields can be moved to their own structure - see 6315920
 315   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 316   JvmtiCachedClassFileData* _cached_class_file;
 317 #endif
 318 
 319 #if INCLUDE_JVMTI
 320   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 321 #endif
 322 
 323   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 324   NOT_PRODUCT(volatile int _shared_class_load_count;) // ensure a shared class is loaded only once
 325 
 326   // Method array.
 327   Array<Method*>* _methods;
 328   // Default Method Array, concrete methods inherited from interfaces
 329   Array<Method*>* _default_methods;
 330   // Interfaces (InstanceKlass*s) this class declares locally to implement.
 331   Array<InstanceKlass*>* _local_interfaces;
 332   // Interfaces (InstanceKlass*s) this class implements transitively.
 333   Array<InstanceKlass*>* _transitive_interfaces;
 334   // Int array containing the original order of method in the class file (for JVMTI).
 335   Array<int>*     _method_ordering;
 336   // Int array containing the vtable_indices for default_methods
 337   // offset matches _default_methods offset
 338   Array<int>*     _default_vtable_indices;
 339 
 340   // Fields information is stored in an UNSIGNED5 encoded stream (see fieldInfo.hpp)
 341   Array<u1>*          _fieldinfo_stream;
 342   Array<u1>*          _fieldinfo_search_table;
 343   Array<FieldStatus>* _fields_status;
 344 
 345   Array<InlineLayoutInfo>* _inline_layout_info_array;
 346   Array<u2>* _loadable_descriptors;
 347   const InlineKlassFixedBlock* _adr_inlineklass_fixed_block;
 348 
 349   // embedded Java vtable follows here
 350   // embedded Java itables follows here
 351   // embedded static fields follows here
 352   // embedded nonstatic oop-map blocks follows here
 353   // embedded implementor of this interface follows here
 354   //   The embedded implementor only exists if the current klass is an
 355   //   interface. The possible values of the implementor fall into following
 356   //   three cases:
 357   //     null: no implementor.
 358   //     A Klass* that's not itself: one implementor.
 359   //     Itself: more than one implementors.
 360   //
 361 
 362   friend class SystemDictionary;
 363 
 364   static bool _disable_method_binary_search;
 365 
 366   // Controls finalizer registration
 367   static bool _finalization_enabled;
 368 
 369  public:
 370 
 371   // Queries finalization state
 372   static bool is_finalization_enabled() { return _finalization_enabled; }
 373 
 374   // Sets finalization state
 375   static void set_finalization_enabled(bool val) { _finalization_enabled = val; }
 376 
 377   // Quick checks for the loader that defined this class (without switching on this->class_loader())
 378   bool defined_by_boot_loader() const      { return _misc_flags.defined_by_boot_loader(); }
 379   bool defined_by_platform_loader() const  { return _misc_flags.defined_by_platform_loader(); }
 380   bool defined_by_app_loader() const       { return _misc_flags.defined_by_app_loader(); }
 381   bool defined_by_other_loaders() const    { return _misc_flags.defined_by_other_loaders(); }
 382   void set_class_loader_type()             { _misc_flags.set_class_loader_type(_class_loader_data); }
 383 
 384   // Check if the class can be shared in CDS
 385   bool is_shareable() const;
 386 
 387   bool shared_loading_failed() const { return _misc_flags.shared_loading_failed(); }
 388 
 389   void set_shared_loading_failed() { _misc_flags.set_shared_loading_failed(true); }
 390 
 391   bool has_nonstatic_fields() const        { return _misc_flags.has_nonstatic_fields(); }
 392   void set_has_nonstatic_fields(bool b)    { _misc_flags.set_has_nonstatic_fields(b); }
 393 
 394   bool has_localvariable_table() const     { return _misc_flags.has_localvariable_table(); }
 395   void set_has_localvariable_table(bool b) { _misc_flags.set_has_localvariable_table(b); }
 396 
 397   bool has_inline_type_fields() const { return _misc_flags.has_inline_type_fields(); }
 398   void set_has_inline_type_fields()   { _misc_flags.set_has_inline_type_fields(true); }
 399 
 400   bool is_naturally_atomic() const  { return _misc_flags.is_naturally_atomic(); }
 401   void set_is_naturally_atomic()    { _misc_flags.set_is_naturally_atomic(true); }
 402 
 403   // Query if this class has atomicity requirements (default is yes)
 404   // This bit can occur anywhere, but is only significant
 405   // for inline classes *and* their super types.
 406   // It inherits from supers.
 407   // Its value depends on the ForceNonTearable VM option, the LooselyConsistentValue annotation
 408   // and the presence of flat fields with atomicity requirements
 409   bool must_be_atomic() const { return _misc_flags.must_be_atomic(); }
 410   void set_must_be_atomic()   { _misc_flags.set_must_be_atomic(true); }
 411 
 412   // field sizes
 413   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 414   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 415 
 416   int static_field_size() const            { return _static_field_size; }
 417   void set_static_field_size(int size)     { _static_field_size = size; }
 418 
 419   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 420   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 421 
 422   // Java itable
 423   int  itable_length() const               { return _itable_len; }
 424   void set_itable_length(int len)          { _itable_len = len; }
 425 
 426   // array klasses
 427   ObjArrayKlass* array_klasses() const     { return _array_klasses; }
 428   inline ObjArrayKlass* array_klasses_acquire() const; // load with acquire semantics
 429   inline void release_set_array_klasses(ObjArrayKlass* k); // store with release semantics
 430   void set_array_klasses(ObjArrayKlass* k) { _array_klasses = k; }
 431 
 432   // methods
 433   Array<Method*>* methods() const          { return _methods; }
 434   void set_methods(Array<Method*>* a)      { _methods = a; }
 435   Method* method_with_idnum(int idnum) const;
 436   Method* method_with_orig_idnum(int idnum) const;
 437   Method* method_with_orig_idnum(int idnum, int version) const;
 438 
 439   // method ordering
 440   Array<int>* method_ordering() const     { return _method_ordering; }
 441   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 442   void copy_method_ordering(const intArray* m, TRAPS);
 443 
 444   // default_methods
 445   Array<Method*>* default_methods() const  { return _default_methods; }
 446   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 447 
 448   // default method vtable_indices
 449   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 450   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 451   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 452 
 453   // interfaces
 454   Array<InstanceKlass*>* local_interfaces() const          { return _local_interfaces; }
 455   void set_local_interfaces(Array<InstanceKlass*>* a)      {
 456     guarantee(_local_interfaces == nullptr || a == nullptr, "Just checking");
 457     _local_interfaces = a; }
 458 
 459   Array<InstanceKlass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 460   void set_transitive_interfaces(Array<InstanceKlass*>* a) {
 461     guarantee(_transitive_interfaces == nullptr || a == nullptr, "Just checking");
 462     _transitive_interfaces = a;
 463   }
 464 
 465  private:
 466   friend class fieldDescriptor;
 467   FieldInfo field(int index) const;
 468 
 469  public:
 470   int     field_offset      (int index) const { return field(index).offset(); }
 471   int     field_access_flags(int index) const { return field(index).access_flags().as_field_flags(); }
 472   FieldInfo::FieldFlags field_flags(int index) const { return field(index).field_flags(); }
 473   FieldStatus field_status(int index)   const { return fields_status()->at(index); }
 474   inline Symbol* field_name        (int index) const;
 475   inline Symbol* field_signature   (int index) const;
 476   bool field_is_flat(int index) const { return field_flags(index).is_flat(); }
 477   bool field_has_null_marker(int index) const { return field_flags(index).has_null_marker(); }
 478   bool field_is_null_free_inline_type(int index) const;
 479   bool is_class_in_loadable_descriptors_attribute(Symbol* name) const;
 480 
 481   int null_marker_offset(int index) const { return inline_layout_info(index).null_marker_offset(); }
 482 
 483   // Number of Java declared fields
 484   int java_fields_count() const;
 485   int total_fields_count() const;
 486 
 487   Array<u1>* fieldinfo_stream() const { return _fieldinfo_stream; }
 488   void set_fieldinfo_stream(Array<u1>* fis) { _fieldinfo_stream = fis; }
 489 
 490   Array<u1>* fieldinfo_search_table() const { return _fieldinfo_search_table; }
 491   void set_fieldinfo_search_table(Array<u1>* table) { _fieldinfo_search_table = table; }
 492 
 493   Array<FieldStatus>* fields_status() const {return _fields_status; }
 494   void set_fields_status(Array<FieldStatus>* array) { _fields_status = array; }
 495 
 496   Array<u2>* loadable_descriptors() const { return _loadable_descriptors; }
 497   void set_loadable_descriptors(Array<u2>* c) { _loadable_descriptors = c; }
 498 
 499   // inner classes
 500   Array<u2>* inner_classes() const       { return _inner_classes; }
 501   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 502 
 503   // nest members
 504   Array<u2>* nest_members() const     { return _nest_members; }
 505   void set_nest_members(Array<u2>* m) { _nest_members = m; }
 506 
 507   // nest-host index
 508   jushort nest_host_index() const { return _nest_host_index; }
 509   void set_nest_host_index(u2 i)  { _nest_host_index = i; }
 510   // dynamic nest member support
 511   void set_nest_host(InstanceKlass* host);
 512 
 513   // record components
 514   Array<RecordComponent*>* record_components() const { return _record_components; }
 515   void set_record_components(Array<RecordComponent*>* record_components) {
 516     _record_components = record_components;
 517   }
 518   bool is_record() const;
 519 
 520   // test for enum class (or possibly an anonymous subclass within a sealed enum)
 521   bool is_enum_subclass() const;
 522 
 523   // permitted subclasses
 524   Array<u2>* permitted_subclasses() const     { return _permitted_subclasses; }
 525   void set_permitted_subclasses(Array<u2>* s) { _permitted_subclasses = s; }
 526 
 527 private:
 528   // Called to verify that k is a member of this nest - does not look at k's nest-host,
 529   // nor does it resolve any CP entries or load any classes.
 530   bool has_nest_member(JavaThread* current, InstanceKlass* k) const;
 531 
 532 public:
 533   // Call this only if you know that the nest host has been initialized.
 534   InstanceKlass* nest_host_not_null() {
 535     assert(_nest_host != nullptr, "must be");
 536     return _nest_host;
 537   }
 538   InstanceKlass* nest_host_or_null() {
 539     return _nest_host;
 540   }
 541   // Used to construct informative IllegalAccessError messages at a higher level,
 542   // if there was an issue resolving or validating the nest host.
 543   // Returns null if there was no error.
 544   const char* nest_host_error();
 545   // Returns nest-host class, resolving and validating it if needed.
 546   // Returns null if resolution is not possible from the calling context.
 547   InstanceKlass* nest_host(TRAPS);
 548   // Check if this klass is a nestmate of k - resolves this nest-host and k's
 549   bool has_nestmate_access_to(InstanceKlass* k, TRAPS);
 550 
 551   // Called to verify that k is a permitted subclass of this class.
 552   // The incoming stringStream is used for logging, and for the caller to create
 553   // a detailed exception message on failure.
 554   bool has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const;
 555 
 556   enum InnerClassAttributeOffset {
 557     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 558     inner_class_inner_class_info_offset = 0,
 559     inner_class_outer_class_info_offset = 1,
 560     inner_class_inner_name_offset = 2,
 561     inner_class_access_flags_offset = 3,
 562     inner_class_next_offset = 4
 563   };
 564 
 565   enum EnclosingMethodAttributeOffset {
 566     enclosing_method_class_index_offset = 0,
 567     enclosing_method_method_index_offset = 1,
 568     enclosing_method_attribute_size = 2
 569   };
 570 
 571   // package
 572   PackageEntry* package() const     { return _package_entry; }
 573   ModuleEntry* module() const;
 574   bool in_javabase_module() const;
 575   bool in_unnamed_package() const   { return (_package_entry == nullptr); }
 576   void set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS);
 577   // If the package for the InstanceKlass is in the boot loader's package entry
 578   // table then sets the classpath_index field so that
 579   // get_system_package() will know to return a non-null value for the
 580   // package's location.  And, so that the package will be added to the list of
 581   // packages returned by get_system_packages().
 582   // For packages whose classes are loaded from the boot loader class path, the
 583   // classpath_index indicates which entry on the boot loader class path.
 584   void set_classpath_index(s2 path_index);
 585   bool is_same_class_package(const Klass* class2) const;
 586   bool is_same_class_package(oop other_class_loader, const Symbol* other_class_name) const;
 587 
 588   // find an enclosing class
 589   InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const;
 590 
 591   // Find InnerClasses attribute and return outer_class_info_index & inner_name_index.
 592   bool find_inner_classes_attr(int* ooff, int* noff, TRAPS) const;
 593 
 594   // Check if this klass can be null-free
 595   static void check_can_be_annotated_with_NullRestricted(InstanceKlass* type, Symbol* container_klass_name, TRAPS);
 596 
 597  private:
 598   // Check prohibited package ("java/" only loadable by boot or platform loaders)
 599   static void check_prohibited_package(Symbol* class_name,
 600                                        ClassLoaderData* loader_data,
 601                                        TRAPS);
 602 
 603   JavaThread* init_thread()  { return AtomicAccess::load(&_init_thread); }
 604   const char* init_thread_name() {
 605     return init_thread()->name_raw();
 606   }
 607 
 608  public:
 609   // initialization state
 610   bool is_loaded() const                   { return init_state() >= loaded; }
 611   bool is_linked() const                   { return init_state() >= linked; }
 612   bool is_initialized() const              { return init_state() == fully_initialized; }
 613   bool is_not_initialized() const          { return init_state() <  being_initialized; }
 614   bool is_being_initialized() const        { return init_state() == being_initialized; }
 615   bool is_in_error_state() const           { return init_state() == initialization_error; }
 616   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 617   ClassState  init_state() const           { return AtomicAccess::load_acquire(&_init_state); }
 618   const char* init_state_name() const;
 619   bool is_rewritten() const                { return _misc_flags.rewritten(); }
 620 
 621   // is this a sealed class
 622   bool is_sealed() const;
 623 
 624   // defineClass specified verification
 625   bool should_verify_class() const         { return _misc_flags.should_verify_class(); }
 626   void set_should_verify_class(bool value) { _misc_flags.set_should_verify_class(value); }
 627 
 628   // marking
 629   bool is_marked_dependent() const         { return _misc_flags.is_marked_dependent(); }
 630   void set_is_marked_dependent(bool value) { _misc_flags.set_is_marked_dependent(value); }
 631 
 632   static ByteSize kind_offset() { return in_ByteSize(offset_of(InstanceKlass, _kind)); }
 633   static ByteSize misc_flags_offset() { return in_ByteSize(offset_of(InstanceKlass, _misc_flags)); }
 634 
 635   // initialization (virtuals from Klass)
 636   bool should_be_initialized() const;  // means that initialize should be called
 637   void initialize_with_aot_initialized_mirror(TRAPS);
 638   void assert_no_clinit_will_run_for_aot_initialized_class() const NOT_DEBUG_RETURN;
 639   void initialize(TRAPS);
 640   void link_class(TRAPS);
 641   bool link_class_or_fail(TRAPS); // returns false on failure
 642   void rewrite_class(TRAPS);
 643   void link_methods(TRAPS);
 644   Method* class_initializer() const;
 645   bool interface_needs_clinit_execution_as_super(bool also_check_supers=true) const;
 646 
 647   // reference type
 648   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 649 
 650   int acmp_maps_offset() const {
 651     assert(_acmp_maps_offset != 0, "Not initialized");
 652     return _acmp_maps_offset;
 653   }
 654   void set_acmp_maps_offset(int offset) { _acmp_maps_offset = offset; }
 655 
 656   // this class cp index
 657   u2 this_class_index() const             { return _this_class_index; }
 658   void set_this_class_index(u2 index)     { _this_class_index = index; }
 659 
 660   static ByteSize reference_type_offset() { return byte_offset_of(InstanceKlass, _reference_type); }
 661 
 662   // find local field, returns true if found
 663   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 664   // find field in direct superinterfaces, returns the interface in which the field is defined
 665   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 666   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 667   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 668   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 669   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 670 
 671   // find a non-static or static field given its offset within the class.
 672   bool contains_field_offset(int offset);
 673 
 674   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 675   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 676 
 677  private:
 678   inline static int quick_search(const Array<Method*>* methods, const Symbol* name);
 679 
 680  public:
 681   static void disable_method_binary_search() {
 682     _disable_method_binary_search = true;
 683   }
 684 
 685   // find a local method (returns null if not found)
 686   Method* find_method(const Symbol* name, const Symbol* signature) const;
 687   static Method* find_method(const Array<Method*>* methods,
 688                              const Symbol* name,
 689                              const Symbol* signature);
 690 
 691   // find a local method, but skip static methods
 692   Method* find_instance_method(const Symbol* name, const Symbol* signature,
 693                                PrivateLookupMode private_mode) const;
 694   static Method* find_instance_method(const Array<Method*>* methods,
 695                                       const Symbol* name,
 696                                       const Symbol* signature,
 697                                       PrivateLookupMode private_mode);
 698 
 699   // find a local method (returns null if not found)
 700   Method* find_local_method(const Symbol* name,
 701                             const Symbol* signature,
 702                             OverpassLookupMode overpass_mode,
 703                             StaticLookupMode static_mode,
 704                             PrivateLookupMode private_mode) const;
 705 
 706   // find a local method from given methods array (returns null if not found)
 707   static Method* find_local_method(const Array<Method*>* methods,
 708                                    const Symbol* name,
 709                                    const Symbol* signature,
 710                                    OverpassLookupMode overpass_mode,
 711                                    StaticLookupMode static_mode,
 712                                    PrivateLookupMode private_mode);
 713 
 714   // find a local method index in methods or default_methods (returns -1 if not found)
 715   static int find_method_index(const Array<Method*>* methods,
 716                                const Symbol* name,
 717                                const Symbol* signature,
 718                                OverpassLookupMode overpass_mode,
 719                                StaticLookupMode static_mode,
 720                                PrivateLookupMode private_mode);
 721 
 722   // lookup operation (returns null if not found)
 723   Method* uncached_lookup_method(const Symbol* name,
 724                                  const Symbol* signature,
 725                                  OverpassLookupMode overpass_mode,
 726                                  PrivateLookupMode private_mode = PrivateLookupMode::find) const;
 727 
 728   // lookup a method in all the interfaces that this class implements
 729   // (returns null if not found)
 730   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, DefaultsLookupMode defaults_mode) const;
 731 
 732   // lookup a method in local defaults then in all interfaces
 733   // (returns null if not found)
 734   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 735 
 736   // Find method indices by name.  If a method with the specified name is
 737   // found the index to the first method is returned, and 'end' is filled in
 738   // with the index of first non-name-matching method.  If no method is found
 739   // -1 is returned.
 740   int find_method_by_name(const Symbol* name, int* end) const;
 741   static int find_method_by_name(const Array<Method*>* methods,
 742                                  const Symbol* name, int* end);
 743 
 744   // constant pool
 745   ConstantPool* constants() const        { return _constants; }
 746   void set_constants(ConstantPool* c)    { _constants = c; }
 747 
 748   // protection domain
 749   oop protection_domain() const;
 750 
 751   // signers
 752   objArrayOop signers() const;
 753 
 754   bool is_contended() const                { return _misc_flags.is_contended(); }
 755   void set_is_contended(bool value)        { _misc_flags.set_is_contended(value); }
 756 
 757   // source file name
 758   Symbol* source_file_name() const;
 759   u2 source_file_name_index() const;
 760   void set_source_file_name_index(u2 sourcefile_index);
 761 
 762   // minor and major version numbers of class file
 763   u2 minor_version() const;
 764   void set_minor_version(u2 minor_version);
 765   u2 major_version() const;
 766   void set_major_version(u2 major_version);
 767 
 768   bool supports_inline_types() const;
 769 
 770   // source debug extension
 771   const char* source_debug_extension() const { return _source_debug_extension; }
 772   void set_source_debug_extension(const char* array, int length);
 773 
 774   // nonstatic oop-map blocks
 775   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 776     return oop_map_count * OopMapBlock::size_in_words();
 777   }
 778   unsigned int nonstatic_oop_map_count() const {
 779     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 780   }
 781   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 782   void set_nonstatic_oop_map_size(int words) {
 783     _nonstatic_oop_map_size = words;
 784   }
 785 
 786   bool has_contended_annotations() const { return _misc_flags.has_contended_annotations(); }
 787   void set_has_contended_annotations(bool value)  { _misc_flags.set_has_contended_annotations(value); }
 788 
 789 #if INCLUDE_JVMTI
 790   // Redefinition locking.  Class can only be redefined by one thread at a time.
 791   bool is_being_redefined() const          { return _misc_flags.is_being_redefined(); }
 792   void set_is_being_redefined(bool value)  { _misc_flags.set_is_being_redefined(value); }
 793 
 794   // RedefineClasses() support for previous versions:
 795   void add_previous_version(InstanceKlass* ik, int emcp_method_count);
 796   void purge_previous_version_list();
 797 
 798   InstanceKlass* previous_versions() const { return _previous_versions; }
 799 #else
 800   InstanceKlass* previous_versions() const { return nullptr; }
 801 #endif
 802 
 803   const InstanceKlass* get_klass_version(int version) const;
 804 
 805   bool has_been_redefined() const { return _misc_flags.has_been_redefined(); }
 806   void set_has_been_redefined() { _misc_flags.set_has_been_redefined(true); }
 807 
 808   bool is_scratch_class() const { return _misc_flags.is_scratch_class(); }
 809   void set_is_scratch_class() { _misc_flags.set_is_scratch_class(true); }
 810 
 811   bool has_resolved_methods() const { return _misc_flags.has_resolved_methods(); }
 812   void set_has_resolved_methods()   { _misc_flags.set_has_resolved_methods(true); }
 813   void set_has_resolved_methods(bool value)   { _misc_flags.set_has_resolved_methods(value); }
 814 
 815 public:
 816 #if INCLUDE_JVMTI
 817 
 818   void init_previous_versions() {
 819     _previous_versions = nullptr;
 820   }
 821 
 822  private:
 823   static bool  _should_clean_previous_versions;
 824  public:
 825   static void purge_previous_versions(InstanceKlass* ik) {
 826     if (ik->has_been_redefined()) {
 827       ik->purge_previous_version_list();
 828     }
 829   }
 830 
 831   static bool should_clean_previous_versions_and_reset();
 832   static bool should_clean_previous_versions() { return _should_clean_previous_versions; }
 833 
 834   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 835   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 836     _cached_class_file = data;
 837   }
 838   JvmtiCachedClassFileData * get_cached_class_file();
 839   jint get_cached_class_file_len();
 840   unsigned char * get_cached_class_file_bytes();
 841 
 842   // JVMTI: Support for caching of field indices, types, and offsets
 843   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 844     _jvmti_cached_class_field_map = descriptor;
 845   }
 846   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 847     return _jvmti_cached_class_field_map;
 848   }
 849 #else // INCLUDE_JVMTI
 850 
 851   static void purge_previous_versions(InstanceKlass* ik) { return; };
 852   static bool should_clean_previous_versions_and_reset() { return false; }
 853 
 854   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 855     assert(data == nullptr, "unexpected call with JVMTI disabled");
 856   }
 857   JvmtiCachedClassFileData * get_cached_class_file() { return (JvmtiCachedClassFileData *)nullptr; }
 858 
 859 #endif // INCLUDE_JVMTI
 860 
 861   bool has_nonstatic_concrete_methods() const { return _misc_flags.has_nonstatic_concrete_methods(); }
 862   void set_has_nonstatic_concrete_methods(bool b) { _misc_flags.set_has_nonstatic_concrete_methods(b); }
 863 
 864   bool declares_nonstatic_concrete_methods() const { return _misc_flags.declares_nonstatic_concrete_methods(); }
 865   void set_declares_nonstatic_concrete_methods(bool b) { _misc_flags.set_declares_nonstatic_concrete_methods(b); }
 866 
 867   bool has_miranda_methods () const     { return _misc_flags.has_miranda_methods(); }
 868   void set_has_miranda_methods()        { _misc_flags.set_has_miranda_methods(true); }
 869   bool has_final_method() const         { return _misc_flags.has_final_method(); }
 870   void set_has_final_method()           { _misc_flags.set_has_final_method(true); }
 871 
 872   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 873   inline u2 next_method_idnum();
 874   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 875 
 876   // runtime support for strict statics
 877   bool has_strict_static_fields() const     { return _misc_flags.has_strict_static_fields(); }
 878   void set_has_strict_static_fields(bool b) { _misc_flags.set_has_strict_static_fields(b); }
 879   void notify_strict_static_access(int field_index, bool is_writing, TRAPS);
 880   const char* format_strict_static_message(Symbol* field_name, const char* doing_what = nullptr);
 881   void throw_strict_static_exception(Symbol* field_name, const char* when, TRAPS);
 882 
 883   // generics support
 884   Symbol* generic_signature() const;
 885   u2 generic_signature_index() const;
 886   void set_generic_signature_index(u2 sig_index);
 887 
 888   u2 enclosing_method_data(int offset) const;
 889   u2 enclosing_method_class_index() const {
 890     return enclosing_method_data(enclosing_method_class_index_offset);
 891   }
 892   u2 enclosing_method_method_index() {
 893     return enclosing_method_data(enclosing_method_method_index_offset);
 894   }
 895   void set_enclosing_method_indices(u2 class_index,
 896                                     u2 method_index);
 897 
 898   // jmethodID support
 899   jmethodID get_jmethod_id(Method* method);
 900   void make_methods_jmethod_ids();
 901   jmethodID jmethod_id_or_null(Method* method);
 902   void update_methods_jmethod_cache();
 903 
 904   // annotations support
 905   Annotations* annotations() const          { return _annotations; }
 906   void set_annotations(Annotations* anno)   { _annotations = anno; }
 907 
 908   AnnotationArray* class_annotations() const {
 909     return (_annotations != nullptr) ? _annotations->class_annotations() : nullptr;
 910   }
 911   Array<AnnotationArray*>* fields_annotations() const {
 912     return (_annotations != nullptr) ? _annotations->fields_annotations() : nullptr;
 913   }
 914   AnnotationArray* class_type_annotations() const {
 915     return (_annotations != nullptr) ? _annotations->class_type_annotations() : nullptr;
 916   }
 917   Array<AnnotationArray*>* fields_type_annotations() const {
 918     return (_annotations != nullptr) ? _annotations->fields_type_annotations() : nullptr;
 919   }
 920   // allocation
 921   instanceOop allocate_instance(TRAPS);
 922   static instanceOop allocate_instance(oop cls, TRAPS);
 923 
 924   // additional member function to return a handle
 925   instanceHandle allocate_instance_handle(TRAPS);
 926 
 927   // Helper function
 928   static instanceOop register_finalizer(instanceOop i, TRAPS);
 929 
 930   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 931   // if not, throw either an Error or an Exception.
 932   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 933 
 934   // initialization
 935   void call_class_initializer(TRAPS);
 936   void set_initialization_state_and_notify(ClassState state, TRAPS);
 937 
 938   // OopMapCache support
 939   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 940   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 941   void mask_for(const methodHandle& method, int bci, InterpreterOopMap* entry);
 942 
 943   // JNI identifier support (for static fields - for jni performance)
 944   JNIid* jni_ids()                               { return _jni_ids; }
 945   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 946   JNIid* jni_id_for(int offset);
 947 
 948  public:
 949   // maintenance of deoptimization dependencies
 950   inline DependencyContext dependencies();
 951   void mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes);
 952   void add_dependent_nmethod(nmethod* nm);
 953   void clean_dependency_context();
 954   // Setup link to hierarchy and deoptimize
 955   void add_to_hierarchy(JavaThread* current);
 956 
 957   // On-stack replacement support
 958   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 959   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 960   void add_osr_nmethod(nmethod* n);
 961   bool remove_osr_nmethod(nmethod* n);
 962   int mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m);
 963   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 964 
 965 #if INCLUDE_JVMTI
 966   // Breakpoint support (see methods on Method* for details)
 967   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 968   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 969 #endif
 970 
 971   // support for stub routines
 972   static ByteSize init_state_offset()  { return byte_offset_of(InstanceKlass, _init_state); }
 973   JFR_ONLY(DEFINE_KLASS_TRACE_ID_OFFSET;)
 974   static ByteSize init_thread_offset() { return byte_offset_of(InstanceKlass, _init_thread); }
 975 
 976   static ByteSize inline_layout_info_array_offset() { return in_ByteSize(offset_of(InstanceKlass, _inline_layout_info_array)); }
 977   static ByteSize adr_inlineklass_fixed_block_offset() { return in_ByteSize(offset_of(InstanceKlass, _adr_inlineklass_fixed_block)); }
 978 
 979   // subclass/subinterface checks
 980   bool implements_interface(Klass* k) const;
 981   bool is_same_or_direct_interface(Klass* k) const;
 982 
 983 #ifdef ASSERT
 984   // check whether this class or one of its superclasses was redefined
 985   bool has_redefined_this_or_super() const;
 986 #endif
 987 
 988   // Access to the implementor of an interface.
 989   InstanceKlass* implementor() const;
 990   void set_implementor(InstanceKlass* ik);
 991   int  nof_implementors() const;
 992   void add_implementor(InstanceKlass* ik);  // ik is a new class that implements this interface
 993   void init_implementor();           // initialize
 994 
 995  private:
 996   // link this class into the implementors list of every interface it implements
 997   void process_interfaces();
 998 
 999  public:
1000   // virtual operations from Klass
1001   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
1002                                                   Array<InstanceKlass*>* transitive_interfaces);
1003   bool can_be_primary_super_slow() const;
1004   size_t oop_size(oop obj)  const             { return size_helper(); }
1005   // slow because it's a virtual call and used for verifying the layout_helper.
1006   // Using the layout_helper bits, we can call is_instance_klass without a virtual call.
1007   DEBUG_ONLY(bool is_instance_klass_slow() const      { return true; })
1008 
1009   // Iterators
1010   void do_local_static_fields(FieldClosure* cl);
1011   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
1012   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
1013   void print_nonstatic_fields(FieldClosure* cl); // including inherited and injected fields
1014 
1015   void methods_do(void f(Method* method));
1016 
1017   static InstanceKlass* cast(Klass* k) {
1018     return const_cast<InstanceKlass*>(cast(const_cast<const Klass*>(k)));
1019   }
1020 
1021   static const InstanceKlass* cast(const Klass* k) {
1022     assert(k != nullptr, "k should not be null");
1023     assert(k->is_instance_klass(), "cast to InstanceKlass");
1024     return static_cast<const InstanceKlass*>(k);
1025   }
1026 
1027   // This hides Klass::super(). The _super of an InstanceKlass is
1028   // always an InstanceKlass (or nullptr)
1029   InstanceKlass* super() const {
1030     return (Klass::super() == nullptr) ? nullptr : InstanceKlass::cast(Klass::super());
1031   }
1032 
1033   virtual InstanceKlass* java_super() const {
1034     return InstanceKlass::super();
1035   }
1036 
1037   // Sizing (in words)
1038   static int header_size()            { return sizeof(InstanceKlass)/wordSize; }
1039 
1040   static int size(int vtable_length, int itable_length,
1041                   int nonstatic_oop_map_size,
1042                   bool is_interface,
1043                   bool is_inline_type) {
1044     return align_metadata_size(header_size() +
1045            vtable_length +
1046            itable_length +
1047            nonstatic_oop_map_size +
1048            (is_interface ? (int)sizeof(Klass*)/wordSize : 0) +
1049            (is_inline_type ? (int)sizeof(InlineKlassFixedBlock) : 0));
1050   }
1051 
1052   int size() const                    { return size(vtable_length(),
1053                                                itable_length(),
1054                                                nonstatic_oop_map_size(),
1055                                                is_interface(),
1056                                                is_inline_klass());
1057   }
1058 
1059 
1060   inline intptr_t* start_of_itable() const;
1061   inline intptr_t* end_of_itable() const;
1062   inline oop static_field_base_raw();
1063   bool bounds_check(address addr, bool edge_ok = false, intptr_t size_in_bytes = -1) const PRODUCT_RETURN0;
1064 
1065   inline OopMapBlock* start_of_nonstatic_oop_maps() const;
1066   inline Klass** end_of_nonstatic_oop_maps() const;
1067 
1068   inline InstanceKlass* volatile* adr_implementor() const;
1069 
1070   void set_inline_layout_info_array(Array<InlineLayoutInfo>* array) { _inline_layout_info_array = array; }
1071   Array<InlineLayoutInfo>* inline_layout_info_array() const { return _inline_layout_info_array; }
1072   void set_inline_layout_info(int index, InlineLayoutInfo *info) {
1073     assert(_inline_layout_info_array != nullptr ,"Array not created");
1074     _inline_layout_info_array->at_put(index, *info);
1075   }
1076   InlineLayoutInfo inline_layout_info(int index) const {
1077     assert(_inline_layout_info_array != nullptr ,"Array not created");
1078     return _inline_layout_info_array->at(index);
1079   }
1080   InlineLayoutInfo* inline_layout_info_adr(int index) {
1081     assert(_inline_layout_info_array != nullptr ,"Array not created");
1082     return _inline_layout_info_array->adr_at(index);
1083   }
1084 
1085   inline InlineKlass* get_inline_type_field_klass(int idx) const ;
1086   inline InlineKlass* get_inline_type_field_klass_or_null(int idx) const;
1087 
1088   // Use this to return the size of an instance in heap words:
1089   virtual int size_helper() const {
1090     return layout_helper_to_size_helper(layout_helper());
1091   }
1092 
1093   // This bit is initialized in classFileParser.cpp.
1094   // It is false under any of the following conditions:
1095   //  - the class is abstract (including any interface)
1096   //  - the class size is larger than FastAllocateSizeLimit
1097   //  - the class is java/lang/Class, which cannot be allocated directly
1098   bool can_be_fastpath_allocated() const {
1099     return !layout_helper_needs_slow_path(layout_helper());
1100   }
1101 
1102   // Java itable
1103   klassItable itable() const;        // return klassItable wrapper
1104   Method* method_at_itable(InstanceKlass* holder, int index, TRAPS);
1105   Method* method_at_itable_or_null(InstanceKlass* holder, int index, bool& itable_entry_found);
1106   int vtable_index_of_interface_method(Method* method);
1107 
1108 #if INCLUDE_JVMTI
1109   void adjust_default_methods(bool* trace_name_printed);
1110 #endif // INCLUDE_JVMTI
1111 
1112   void clean_weak_instanceklass_links();
1113  private:
1114   void clean_implementors_list();
1115   void clean_method_data();
1116 
1117  public:
1118   // Explicit metaspace deallocation of fields
1119   // For RedefineClasses and class file parsing errors, we need to deallocate
1120   // instanceKlasses and the metadata they point to.
1121   void deallocate_contents(ClassLoaderData* loader_data);
1122   static void deallocate_methods(ClassLoaderData* loader_data,
1123                                  Array<Method*>* methods);
1124   void static deallocate_interfaces(ClassLoaderData* loader_data,
1125                                     const InstanceKlass* super_klass,
1126                                     Array<InstanceKlass*>* local_interfaces,
1127                                     Array<InstanceKlass*>* transitive_interfaces);
1128   void static deallocate_record_components(ClassLoaderData* loader_data,
1129                                            Array<RecordComponent*>* record_component);
1130 
1131   virtual bool on_stack() const;
1132 
1133   // callbacks for actions during class unloading
1134   static void unload_class(InstanceKlass* ik);
1135 
1136   virtual void release_C_heap_structures(bool release_sub_metadata = true);
1137 
1138   // Naming
1139   const char* signature_name() const;
1140   const char* signature_name_of_carrier(char c) const;
1141 
1142   // Oop fields (and metadata) iterators
1143   //
1144   // The InstanceKlass iterators also visits the Object's klass.
1145 
1146   // Forward iteration
1147  public:
1148   // Iterate over all oop fields in the oop maps.
1149   template <typename T, class OopClosureType>
1150   inline void oop_oop_iterate_oop_maps(oop obj, OopClosureType* closure);
1151 
1152   // Iterate over all oop fields and metadata.
1153   template <typename T, class OopClosureType>
1154   inline void oop_oop_iterate(oop obj, OopClosureType* closure);
1155 
1156   // Iterate over all oop fields in one oop map.
1157   template <typename T, class OopClosureType>
1158   inline void oop_oop_iterate_oop_map(OopMapBlock* map, oop obj, OopClosureType* closure);
1159 
1160 
1161   // Reverse iteration
1162   // Iterate over all oop fields and metadata.
1163   template <typename T, class OopClosureType>
1164   inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
1165 
1166  private:
1167   // Iterate over all oop fields in the oop maps.
1168   template <typename T, class OopClosureType>
1169   inline void oop_oop_iterate_oop_maps_reverse(oop obj, OopClosureType* closure);
1170 
1171   // Iterate over all oop fields in one oop map.
1172   template <typename T, class OopClosureType>
1173   inline void oop_oop_iterate_oop_map_reverse(OopMapBlock* map, oop obj, OopClosureType* closure);
1174 
1175 
1176   // Bounded range iteration
1177  public:
1178   // Iterate over all oop fields in the oop maps.
1179   template <typename T, class OopClosureType>
1180   inline void oop_oop_iterate_oop_maps_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1181 
1182   // Iterate over all oop fields and metadata.
1183   template <typename T, class OopClosureType>
1184   inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1185 
1186  private:
1187   // Iterate over all oop fields in one oop map.
1188   template <typename T, class OopClosureType>
1189   inline void oop_oop_iterate_oop_map_bounded(OopMapBlock* map, oop obj, OopClosureType* closure, MemRegion mr);
1190 
1191 
1192  public:
1193   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
1194 
1195 private:
1196   // initialization state
1197   void set_init_state(ClassState state);
1198   void set_rewritten()                  { _misc_flags.set_rewritten(true); }
1199   void set_init_thread(JavaThread *thread)  {
1200     assert((thread == JavaThread::current() && _init_thread == nullptr) ||
1201            (thread == nullptr && _init_thread == JavaThread::current()), "Only one thread is allowed to own initialization");
1202     AtomicAccess::store(&_init_thread, thread);
1203   }
1204 
1205   jmethodID* methods_jmethod_ids_acquire() const;
1206   void release_set_methods_jmethod_ids(jmethodID* jmeths);
1207   // This nulls out obsolete jmethodIDs for all methods in 'klass'.
1208   static void clear_obsolete_jmethod_ids(InstanceKlass* klass);
1209   jmethodID update_jmethod_id(jmethodID* jmeths, Method* method, int idnum);
1210 
1211 public:
1212   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
1213   // Must be one per class and it has to be a VM internal object so java code
1214   // cannot lock it (like the mirror).
1215   // It has to be an object not a Mutex because it's held through java calls.
1216   oop init_lock() const;
1217 
1218   // Returns the array class for the n'th dimension
1219   virtual ArrayKlass* array_klass(int n, TRAPS);
1220   virtual ArrayKlass* array_klass_or_null(int n);
1221 
1222   // Returns the array class with this class as element type
1223   virtual ArrayKlass* array_klass(TRAPS);
1224   virtual ArrayKlass* array_klass_or_null();
1225 
1226   static void clean_initialization_error_table();
1227 private:
1228   void fence_and_clear_init_lock();
1229 
1230   bool link_class_impl                           (TRAPS);
1231   bool verify_code                               (TRAPS);
1232   void initialize_impl                           (TRAPS);
1233   void initialize_super_interfaces               (TRAPS);
1234 
1235   void add_initialization_error(JavaThread* current, Handle exception);
1236   oop get_initialization_error(JavaThread* current);
1237 
1238   // find a local method (returns null if not found)
1239   Method* find_method_impl(const Symbol* name,
1240                            const Symbol* signature,
1241                            OverpassLookupMode overpass_mode,
1242                            StaticLookupMode static_mode,
1243                            PrivateLookupMode private_mode) const;
1244 
1245   static Method* find_method_impl(const Array<Method*>* methods,
1246                                   const Symbol* name,
1247                                   const Symbol* signature,
1248                                   OverpassLookupMode overpass_mode,
1249                                   StaticLookupMode static_mode,
1250                                   PrivateLookupMode private_mode);
1251 
1252 #if INCLUDE_JVMTI
1253   // RedefineClasses support
1254   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1255   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1256 #endif
1257   // log class name to classlist
1258   void log_to_classlist() const;
1259 public:
1260 
1261 #if INCLUDE_CDS
1262   // CDS support - remove and restore oops from metadata. Oops are not shared.
1263   virtual void remove_unshareable_info();
1264   void remove_unshareable_flags();
1265   virtual void remove_java_mirror();
1266   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
1267   void init_shared_package_entry();
1268   bool can_be_verified_at_dumptime() const;
1269   void compute_has_loops_flag_for_methods();
1270 #endif
1271   bool     has_init_deps_processed() const { return _misc_flags.has_init_deps_processed(); }
1272   void set_has_init_deps_processed() {
1273     assert(is_initialized(), "");
1274     assert(!has_init_deps_processed(), "already set"); // one-off action
1275     _misc_flags.set_has_init_deps_processed(true);
1276   }
1277 
1278   u2 compute_modifier_flags() const;
1279 
1280 public:
1281   // JVMTI support
1282   jint jvmti_class_status() const;
1283 
1284   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
1285 
1286  public:
1287   // Printing
1288   void print_on(outputStream* st) const;
1289   void print_value_on(outputStream* st) const;
1290 
1291   void oop_print_value_on(oop obj, outputStream* st);
1292 
1293   void oop_print_on      (oop obj, outputStream* st) { oop_print_on(obj, st, 0, 0); }
1294   void oop_print_on      (oop obj, outputStream* st, int indent = 0, int base_offset = 0);
1295 
1296 #ifndef PRODUCT
1297   void print_dependent_nmethods(bool verbose = false);
1298   bool is_dependent_nmethod(nmethod* nm);
1299   bool verify_itable_index(int index);
1300 #endif
1301 
1302   const char* internal_name() const;
1303 
1304   // Verification
1305   void verify_on(outputStream* st);
1306 
1307   void oop_verify_on(oop obj, outputStream* st);
1308 
1309   // Logging
1310   void print_class_load_logging(ClassLoaderData* loader_data,
1311                                 const ModuleEntry* module_entry,
1312                                 const ClassFileStream* cfs) const;
1313  private:
1314   void print_class_load_cause_logging() const;
1315   void print_class_load_helper(ClassLoaderData* loader_data,
1316                                const ModuleEntry* module_entry,
1317                                const ClassFileStream* cfs) const;
1318 };
1319 
1320 // for adding methods
1321 // UNSET_IDNUM return means no more ids available
1322 inline u2 InstanceKlass::next_method_idnum() {
1323   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1324     return ConstMethod::UNSET_IDNUM; // no more ids available
1325   } else {
1326     return _idnum_allocated_count++;
1327   }
1328 }
1329 
1330 class PrintClassClosure : public KlassClosure {
1331 private:
1332   outputStream* _st;
1333   bool _verbose;
1334 public:
1335   PrintClassClosure(outputStream* st, bool verbose);
1336 
1337   void do_klass(Klass* k);
1338 };
1339 
1340 /* JNIid class for jfieldIDs only */
1341 class JNIid: public CHeapObj<mtClass> {
1342   friend class VMStructs;
1343  private:
1344   InstanceKlass*     _holder;
1345   JNIid*             _next;
1346   int                _offset;
1347 #ifdef ASSERT
1348   bool               _is_static_field_id;
1349 #endif
1350 
1351  public:
1352   // Accessors
1353   InstanceKlass* holder() const   { return _holder; }
1354   int offset() const              { return _offset; }
1355   JNIid* next()                   { return _next; }
1356   // Constructor
1357   JNIid(InstanceKlass* holder, int offset, JNIid* next);
1358   // Identifier lookup
1359   JNIid* find(int offset);
1360 
1361   bool find_local_field(fieldDescriptor* fd) {
1362     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1363   }
1364 
1365   static void deallocate(JNIid* id);
1366   // Debugging
1367 #ifdef ASSERT
1368   bool is_static_field_id() const { return _is_static_field_id; }
1369   void set_is_static_field_id()   { _is_static_field_id = true; }
1370 #endif
1371   void verify(InstanceKlass* holder);
1372 };
1373 
1374 // An iterator that's used to access the inner classes indices in the
1375 // InstanceKlass::_inner_classes array.
1376 class InnerClassesIterator : public StackObj {
1377  private:
1378   Array<jushort>* _inner_classes;
1379   int _length;
1380   int _idx;
1381  public:
1382 
1383   InnerClassesIterator(const InstanceKlass* k) {
1384     _inner_classes = k->inner_classes();
1385     if (k->inner_classes() != nullptr) {
1386       _length = _inner_classes->length();
1387       // The inner class array's length should be the multiple of
1388       // inner_class_next_offset if it only contains the InnerClasses
1389       // attribute data, or it should be
1390       // n*inner_class_next_offset+enclosing_method_attribute_size
1391       // if it also contains the EnclosingMethod data.
1392       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1393               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1394              "just checking");
1395       // Remove the enclosing_method portion if exists.
1396       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1397         _length -= InstanceKlass::enclosing_method_attribute_size;
1398       }
1399     } else {
1400       _length = 0;
1401     }
1402     _idx = 0;
1403   }
1404 
1405   int length() const {
1406     return _length;
1407   }
1408 
1409   void next() {
1410     _idx += InstanceKlass::inner_class_next_offset;
1411   }
1412 
1413   bool done() const {
1414     return (_idx >= _length);
1415   }
1416 
1417   u2 inner_class_info_index() const {
1418     return _inner_classes->at(
1419                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1420   }
1421 
1422   void set_inner_class_info_index(u2 index) {
1423     _inner_classes->at_put(
1424                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1425   }
1426 
1427   u2 outer_class_info_index() const {
1428     return _inner_classes->at(
1429                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1430   }
1431 
1432   void set_outer_class_info_index(u2 index) {
1433     _inner_classes->at_put(
1434                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1435   }
1436 
1437   u2 inner_name_index() const {
1438     return _inner_classes->at(
1439                _idx + InstanceKlass::inner_class_inner_name_offset);
1440   }
1441 
1442   void set_inner_name_index(u2 index) {
1443     _inner_classes->at_put(
1444                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1445   }
1446 
1447   u2 inner_access_flags() const {
1448     return _inner_classes->at(
1449                _idx + InstanceKlass::inner_class_access_flags_offset);
1450   }
1451 };
1452 
1453 // Iterator over class hierarchy under a particular class. Implements depth-first pre-order traversal.
1454 // Usage:
1455 //  for (ClassHierarchyIterator iter(root_klass); !iter.done(); iter.next()) {
1456 //    Klass* k = iter.klass();
1457 //    ...
1458 //  }
1459 class ClassHierarchyIterator : public StackObj {
1460  private:
1461   InstanceKlass* _root;
1462   Klass*         _current;
1463   bool           _visit_subclasses;
1464 
1465  public:
1466   ClassHierarchyIterator(InstanceKlass* root) : _root(root), _current(root), _visit_subclasses(true) {
1467     assert(_root == _current, "required"); // initial state
1468   }
1469 
1470   bool done() {
1471     return (_current == nullptr);
1472   }
1473 
1474   // Make a step iterating over the class hierarchy under the root class.
1475   // Skips subclasses if requested.
1476   void next();
1477 
1478   Klass* klass() {
1479     assert(!done(), "sanity");
1480     return _current;
1481   }
1482 
1483   // Skip subclasses of the current class.
1484   void skip_subclasses() {
1485     _visit_subclasses = false;
1486   }
1487 };
1488 
1489 #endif // SHARE_OOPS_INSTANCEKLASS_HPP