1 /*
   2  * Copyright (c) 1997, 2016, 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_VM_OOPS_INSTANCEKLASS_HPP
  26 #define SHARE_VM_OOPS_INSTANCEKLASS_HPP
  27 
  28 #include "classfile/classLoader.hpp"
  29 #include "classfile/classLoaderData.hpp"
  30 #include "classfile/moduleEntry.hpp"
  31 #include "classfile/packageEntry.hpp"
  32 #include "gc/shared/specialized_oop_closures.hpp"
  33 #include "logging/logLevel.hpp"
  34 #include "memory/referenceType.hpp"
  35 #include "oops/annotations.hpp"
  36 #include "oops/constMethod.hpp"
  37 #include "oops/fieldInfo.hpp"
  38 #include "oops/instanceOop.hpp"
  39 #include "oops/klassVtable.hpp"
  40 #include "runtime/handles.hpp"
  41 #include "runtime/os.hpp"
  42 #include "trace/traceMacros.hpp"
  43 #include "utilities/accessFlags.hpp"
  44 #include "utilities/bitMap.inline.hpp"
  45 #include "utilities/macros.hpp"
  46 
  47 // An InstanceKlass is the VM level representation of a Java class.
  48 // It contains all information needed for at class at execution runtime.
  49 
  50 //  InstanceKlass embedded field layout (after declared fields):
  51 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  52 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  53 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  54 //      indicating where oops are located in instances of this klass.
  55 //    [EMBEDDED implementor of the interface] only exist for interface
  56 //    [EMBEDDED host klass        ] only exist for an anonymous class (JSR 292 enabled)
  57 
  58 
  59 // forward declaration for class -- see below for definition
  60 #if INCLUDE_JVMTI
  61 class BreakpointInfo;
  62 #endif
  63 class ClassFileParser;
  64 class KlassDepChange;
  65 class DependencyContext;
  66 class fieldDescriptor;
  67 class jniIdMapBase;
  68 class JNIid;
  69 class JvmtiCachedClassFieldMap;
  70 class MemberNameTable;
  71 class SuperTypeClosure;
  72 
  73 // This is used in iterators below.
  74 class FieldClosure: public StackObj {
  75 public:
  76   virtual void do_field(fieldDescriptor* fd) = 0;
  77 };
  78 
  79 #ifndef PRODUCT
  80 // Print fields.
  81 // If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.
  82 class FieldPrinter: public FieldClosure {
  83    oop _obj;
  84    outputStream* _st;
  85  public:
  86    FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}
  87    void do_field(fieldDescriptor* fd);
  88 };
  89 #endif  // !PRODUCT
  90 
  91 // ValueObjs embedded in klass. Describes where oops are located in instances of
  92 // this klass.
  93 class OopMapBlock VALUE_OBJ_CLASS_SPEC {
  94  public:
  95   // Byte offset of the first oop mapped by this block.
  96   int offset() const          { return _offset; }
  97   void set_offset(int offset) { _offset = offset; }
  98 
  99   // Number of oops in this block.
 100   uint count() const         { return _count; }
 101   void set_count(uint count) { _count = count; }
 102 
 103   // sizeof(OopMapBlock) in words.
 104   static const int size_in_words() {
 105     return align_size_up(int(sizeof(OopMapBlock)), wordSize) >>
 106       LogBytesPerWord;
 107   }
 108 
 109  private:
 110   int  _offset;
 111   uint _count;
 112 };
 113 
 114 struct JvmtiCachedClassFileData;
 115 
 116 class InstanceKlass: public Klass {
 117   friend class VMStructs;
 118   friend class JVMCIVMStructs;
 119   friend class ClassFileParser;
 120   friend class CompileReplay;
 121 
 122  protected:
 123   InstanceKlass(const ClassFileParser& parser, unsigned kind);
 124 
 125  public:
 126   InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
 127 
 128   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 129   // of the class loading & initialization procedure, and the use of the states.
 130   enum ClassState {
 131     allocated,                          // allocated (but not yet linked)
 132     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 133     linked,                             // successfully linked/verified (but not initialized yet)
 134     being_initialized,                  // currently running class initializer
 135     fully_initialized,                  // initialized (successfull final state)
 136     initialization_error                // error happened during initialization
 137   };
 138 
 139   static int number_of_instance_classes() { return _total_instanceKlass_count; }
 140 
 141  private:
 142   static volatile int _total_instanceKlass_count;
 143   static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);
 144 
 145  protected:
 146   // Annotations for this class
 147   Annotations*    _annotations;
 148   // Package this class is defined in
 149   PackageEntry*   _package_entry;
 150   // Array classes holding elements of this class.
 151   Klass* volatile _array_klasses;
 152   // Constant pool for this class.
 153   ConstantPool* _constants;
 154   // The InnerClasses attribute and EnclosingMethod attribute. The
 155   // _inner_classes is an array of shorts. If the class has InnerClasses
 156   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 157   // [inner_class_info_index, outer_class_info_index,
 158   // inner_name_index, inner_class_access_flags] for the InnerClasses
 159   // attribute. If the EnclosingMethod attribute exists, it occupies the
 160   // last two shorts [class_index, method_index] of the array. If only
 161   // the InnerClasses attribute exists, the _inner_classes array length is
 162   // number_of_inner_classes * 4. If the class has both InnerClasses
 163   // and EnclosingMethod attributes the _inner_classes array length is
 164   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 165   Array<jushort>* _inner_classes;
 166 
 167   // the source debug extension for this klass, NULL if not specified.
 168   // Specified as UTF-8 string without terminating zero byte in the classfile,
 169   // it is stored in the instanceklass as a NULL-terminated UTF-8 string
 170   const char*     _source_debug_extension;
 171   // Array name derived from this class which needs unreferencing
 172   // if this class is unloaded.
 173   Symbol*         _array_name;
 174 
 175   // Number of heapOopSize words used by non-static fields in this klass
 176   // (including inherited fields but after header_size()).
 177   int             _nonstatic_field_size;
 178   int             _static_field_size;    // number words used by static fields (oop and non-oop) in this klass
 179   // Constant pool index to the utf8 entry of the Generic signature,
 180   // or 0 if none.
 181   u2              _generic_signature_index;
 182   // Constant pool index to the utf8 entry for the name of source file
 183   // containing this klass, 0 if not specified.
 184   u2              _source_file_name_index;
 185   u2              _static_oop_field_count;// number of static oop fields in this klass
 186   u2              _java_fields_count;    // The number of declared Java fields
 187   int             _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
 188 
 189   int             _itable_len;           // length of Java itable (in words)
 190   // _is_marked_dependent can be set concurrently, thus cannot be part of the
 191   // _misc_flags.
 192   bool            _is_marked_dependent;  // used for marking during flushing and deoptimization
 193   bool            _is_being_redefined;   // used for locking redefinition
 194 
 195   // The low two bits of _misc_flags contains the kind field.
 196   // This can be used to quickly discriminate among the four kinds of
 197   // InstanceKlass.
 198 
 199   static const unsigned _misc_kind_field_size = 2;
 200   static const unsigned _misc_kind_field_pos  = 0;
 201   static const unsigned _misc_kind_field_mask = (1u << _misc_kind_field_size) - 1u;
 202 
 203   static const unsigned _misc_kind_other        = 0; // concrete InstanceKlass
 204   static const unsigned _misc_kind_reference    = 1; // InstanceRefKlass
 205   static const unsigned _misc_kind_class_loader = 2; // InstanceClassLoaderKlass
 206   static const unsigned _misc_kind_mirror       = 3; // InstanceMirrorKlass
 207 
 208   // Start after _misc_kind field.
 209   enum {
 210     _misc_rewritten                           = 1 << 2,  // methods rewritten.
 211     _misc_has_nonstatic_fields                = 1 << 3,  // for sizing with UseCompressedOops
 212     _misc_should_verify_class                 = 1 << 4,  // allow caching of preverification
 213     _misc_is_anonymous                        = 1 << 5,  // has embedded _host_klass field
 214     _misc_is_contended                        = 1 << 6,  // marked with contended annotation
 215     _misc_has_nonstatic_concrete_methods      = 1 << 7,  // class/superclass/implemented interfaces has non-static, concrete methods
 216     _misc_declares_nonstatic_concrete_methods = 1 << 8,  // directly declares non-static, concrete methods
 217     _misc_has_been_redefined                  = 1 << 9,  // class has been redefined
 218     _misc_is_scratch_class                    = 1 << 10, // class is the redefined scratch class
 219     _misc_is_shared_boot_class                = 1 << 11, // defining class loader is boot class loader
 220     _misc_is_shared_platform_class            = 1 << 12, // defining class loader is platform class loader
 221     _misc_is_shared_app_class                 = 1 << 13  // defining class loader is app class loader
 222   };
 223   u2 loader_type_bits() {
 224     return _misc_is_shared_boot_class|_misc_is_shared_platform_class|_misc_is_shared_app_class;
 225   }
 226   u2              _misc_flags;
 227   u2              _minor_version;        // minor version number of class file
 228   u2              _major_version;        // major version number of class file
 229   Thread*         _init_thread;          // Pointer to current thread doing initialization (to handle recusive initialization)
 230   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 231   MemberNameTable* _member_names;        // Member names
 232   JNIid*          _jni_ids;              // First JNI identifier for static fields in this class
 233   jmethodID*      volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or NULL if none
 234   intptr_t        _dep_context;          // packed DependencyContext structure
 235   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 236 #if INCLUDE_JVMTI
 237   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 238   // Linked instanceKlasses of previous versions
 239   InstanceKlass* _previous_versions;
 240   // JVMTI fields can be moved to their own structure - see 6315920
 241   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 242   JvmtiCachedClassFileData* _cached_class_file;
 243 #endif
 244 
 245   volatile u2     _idnum_allocated_count;         // JNI/JVMTI: increments with the addition of methods, old ids don't change
 246 
 247   // Class states are defined as ClassState (see above).
 248   // Place the _init_state here to utilize the unused 2-byte after
 249   // _idnum_allocated_count.
 250   u1              _init_state;                    // state of class
 251   u1              _reference_type;                // reference type
 252 
 253 #if INCLUDE_JVMTI
 254   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 255 #endif
 256 
 257   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 258 
 259   // Method array.
 260   Array<Method*>* _methods;
 261   // Default Method Array, concrete methods inherited from interfaces
 262   Array<Method*>* _default_methods;
 263   // Interface (Klass*s) this class declares locally to implement.
 264   Array<Klass*>* _local_interfaces;
 265   // Interface (Klass*s) this class implements transitively.
 266   Array<Klass*>* _transitive_interfaces;
 267   // Int array containing the original order of method in the class file (for JVMTI).
 268   Array<int>*     _method_ordering;
 269   // Int array containing the vtable_indices for default_methods
 270   // offset matches _default_methods offset
 271   Array<int>*     _default_vtable_indices;
 272 
 273   // Instance and static variable information, starts with 6-tuples of shorts
 274   // [access, name index, sig index, initval index, low_offset, high_offset]
 275   // for all fields, followed by the generic signature data at the end of
 276   // the array. Only fields with generic signature attributes have the generic
 277   // signature data set in the array. The fields array looks like following:
 278   //
 279   // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
 280   // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
 281   //      ...
 282   // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
 283   //     [generic signature index]
 284   //     [generic signature index]
 285   //     ...
 286   Array<u2>*      _fields;
 287 
 288   // embedded Java vtable follows here
 289   // embedded Java itables follows here
 290   // embedded static fields follows here
 291   // embedded nonstatic oop-map blocks follows here
 292   // embedded implementor of this interface follows here
 293   //   The embedded implementor only exists if the current klass is an
 294   //   iterface. The possible values of the implementor fall into following
 295   //   three cases:
 296   //     NULL: no implementor.
 297   //     A Klass* that's not itself: one implementor.
 298   //     Itself: more than one implementors.
 299   // embedded host klass follows here
 300   //   The embedded host klass only exists in an anonymous class for
 301   //   dynamic language support (JSR 292 enabled). The host class grants
 302   //   its access privileges to this class also. The host class is either
 303   //   named, or a previously loaded anonymous class. A non-anonymous class
 304   //   or an anonymous class loaded through normal classloading does not
 305   //   have this embedded field.
 306   //
 307 
 308   friend class SystemDictionary;
 309 
 310  public:
 311   u2 loader_type() {
 312     return _misc_flags & loader_type_bits();
 313   }
 314 
 315   bool is_shared_boot_class() const {
 316     return (_misc_flags & _misc_is_shared_boot_class) != 0;
 317   }
 318   bool is_shared_platform_class() const {
 319     return (_misc_flags & _misc_is_shared_platform_class) != 0;
 320   }
 321   bool is_shared_app_class() const {
 322     return (_misc_flags & _misc_is_shared_app_class) != 0;
 323   }
 324 
 325   void set_class_loader_type(s2 loader_type) {
 326     assert(( _misc_flags & loader_type_bits()) == 0,
 327            "Should only be called once for each class.");
 328     switch (loader_type) {
 329     case ClassLoader::BOOT_LOADER:
 330       _misc_flags |= _misc_is_shared_boot_class;
 331        break;
 332     case ClassLoader::PLATFORM_LOADER:
 333       _misc_flags |= _misc_is_shared_platform_class;
 334       break;
 335     case ClassLoader::APP_LOADER:
 336       _misc_flags |= _misc_is_shared_app_class;
 337       break;
 338     default:
 339       ShouldNotReachHere();
 340       break;
 341     }
 342   }
 343 
 344   bool has_nonstatic_fields() const        {
 345     return (_misc_flags & _misc_has_nonstatic_fields) != 0;
 346   }
 347   void set_has_nonstatic_fields(bool b)    {
 348     if (b) {
 349       _misc_flags |= _misc_has_nonstatic_fields;
 350     } else {
 351       _misc_flags &= ~_misc_has_nonstatic_fields;
 352     }
 353   }
 354 
 355   // field sizes
 356   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 357   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 358 
 359   int static_field_size() const            { return _static_field_size; }
 360   void set_static_field_size(int size)     { _static_field_size = size; }
 361 
 362   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 363   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 364 
 365   // Java itable
 366   int  itable_length() const               { return _itable_len; }
 367   void set_itable_length(int len)          { _itable_len = len; }
 368 
 369   // array klasses
 370   Klass* array_klasses() const             { return _array_klasses; }
 371   inline Klass* array_klasses_acquire() const; // load with acquire semantics
 372   void set_array_klasses(Klass* k)         { _array_klasses = k; }
 373   inline void release_set_array_klasses(Klass* k); // store with release semantics
 374 
 375   // methods
 376   Array<Method*>* methods() const          { return _methods; }
 377   void set_methods(Array<Method*>* a)      { _methods = a; }
 378   Method* method_with_idnum(int idnum);
 379   Method* method_with_orig_idnum(int idnum);
 380   Method* method_with_orig_idnum(int idnum, int version);
 381 
 382   // method ordering
 383   Array<int>* method_ordering() const     { return _method_ordering; }
 384   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 385   void copy_method_ordering(const intArray* m, TRAPS);
 386 
 387   // default_methods
 388   Array<Method*>* default_methods() const  { return _default_methods; }
 389   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 390 
 391   // default method vtable_indices
 392   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 393   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 394   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 395 
 396   // interfaces
 397   Array<Klass*>* local_interfaces() const          { return _local_interfaces; }
 398   void set_local_interfaces(Array<Klass*>* a)      {
 399     guarantee(_local_interfaces == NULL || a == NULL, "Just checking");
 400     _local_interfaces = a; }
 401 
 402   Array<Klass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 403   void set_transitive_interfaces(Array<Klass*>* a) {
 404     guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");
 405     _transitive_interfaces = a;
 406   }
 407 
 408  private:
 409   friend class fieldDescriptor;
 410   FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
 411 
 412  public:
 413   int     field_offset      (int index) const { return field(index)->offset(); }
 414   int     field_access_flags(int index) const { return field(index)->access_flags(); }
 415   Symbol* field_name        (int index) const { return field(index)->name(constants()); }
 416   Symbol* field_signature   (int index) const { return field(index)->signature(constants()); }
 417 
 418   // Number of Java declared fields
 419   int java_fields_count() const           { return (int)_java_fields_count; }
 420 
 421   Array<u2>* fields() const            { return _fields; }
 422   void set_fields(Array<u2>* f, u2 java_fields_count) {
 423     guarantee(_fields == NULL || f == NULL, "Just checking");
 424     _fields = f;
 425     _java_fields_count = java_fields_count;
 426   }
 427 
 428   // inner classes
 429   Array<u2>* inner_classes() const       { return _inner_classes; }
 430   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 431 
 432   enum InnerClassAttributeOffset {
 433     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 434     inner_class_inner_class_info_offset = 0,
 435     inner_class_outer_class_info_offset = 1,
 436     inner_class_inner_name_offset = 2,
 437     inner_class_access_flags_offset = 3,
 438     inner_class_next_offset = 4
 439   };
 440 
 441   enum EnclosingMethodAttributeOffset {
 442     enclosing_method_class_index_offset = 0,
 443     enclosing_method_method_index_offset = 1,
 444     enclosing_method_attribute_size = 2
 445   };
 446 
 447   // method override check
 448   bool is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
 449 
 450   // package
 451   PackageEntry* package() const     { return _package_entry; }
 452   ModuleEntry* module() const;
 453   bool in_unnamed_package() const   { return (_package_entry == NULL); }
 454   void set_package(PackageEntry* p) { _package_entry = p; }
 455   void set_package(ClassLoaderData* loader_data, TRAPS);
 456   bool is_same_class_package(const Klass* class2) const;
 457   bool is_same_class_package(oop classloader2, const Symbol* classname2) const;
 458   static bool is_same_class_package(oop class_loader1,
 459                                     const Symbol* class_name1,
 460                                     oop class_loader2,
 461                                     const Symbol* class_name2);
 462 
 463   // find an enclosing class
 464   InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const {
 465     return compute_enclosing_class_impl(this, inner_is_member, THREAD);
 466   }
 467   static InstanceKlass* compute_enclosing_class_impl(const InstanceKlass* self,
 468                                                      bool* inner_is_member,
 469                                                      TRAPS);
 470 
 471   // Find InnerClasses attribute for k and return outer_class_info_index & inner_name_index.
 472   static bool find_inner_classes_attr(instanceKlassHandle k,
 473                                       int* ooff, int* noff, TRAPS);
 474 
 475  private:
 476   // Check prohibited package ("java/" only loadable by boot or platform loaders)
 477   static void check_prohibited_package(Symbol* class_name,
 478                                        Handle class_loader,
 479                                        TRAPS);
 480  public:
 481   // tell if two classes have the same enclosing class (at package level)
 482   bool is_same_package_member(const Klass* class2, TRAPS) const {
 483     return is_same_package_member_impl(this, class2, THREAD);
 484   }
 485   static bool is_same_package_member_impl(const InstanceKlass* self,
 486                                           const Klass* class2,
 487                                           TRAPS);
 488 
 489   // initialization state
 490   bool is_loaded() const                   { return _init_state >= loaded; }
 491   bool is_linked() const                   { return _init_state >= linked; }
 492   bool is_initialized() const              { return _init_state == fully_initialized; }
 493   bool is_not_initialized() const          { return _init_state <  being_initialized; }
 494   bool is_being_initialized() const        { return _init_state == being_initialized; }
 495   bool is_in_error_state() const           { return _init_state == initialization_error; }
 496   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 497   ClassState  init_state()                 { return (ClassState)_init_state; }
 498   bool is_rewritten() const                { return (_misc_flags & _misc_rewritten) != 0; }
 499 
 500   // defineClass specified verification
 501   bool should_verify_class() const         {
 502     return (_misc_flags & _misc_should_verify_class) != 0;
 503   }
 504   void set_should_verify_class(bool value) {
 505     if (value) {
 506       _misc_flags |= _misc_should_verify_class;
 507     } else {
 508       _misc_flags &= ~_misc_should_verify_class;
 509     }
 510   }
 511 
 512   // marking
 513   bool is_marked_dependent() const         { return _is_marked_dependent; }
 514   void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
 515 
 516   // initialization (virtuals from Klass)
 517   bool should_be_initialized() const;  // means that initialize should be called
 518   void initialize(TRAPS);
 519   void link_class(TRAPS);
 520   bool link_class_or_fail(TRAPS); // returns false on failure
 521   void unlink_class();
 522   void rewrite_class(TRAPS);
 523   void link_methods(TRAPS);
 524   Method* class_initializer();
 525 
 526   // set the class to initialized if no static initializer is present
 527   void eager_initialize(Thread *thread);
 528 
 529   // reference type
 530   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 531   void set_reference_type(ReferenceType t) {
 532     assert(t == (u1)t, "overflow");
 533     _reference_type = (u1)t;
 534   }
 535 
 536   static ByteSize reference_type_offset() { return in_ByteSize(offset_of(InstanceKlass, _reference_type)); }
 537 
 538   // find local field, returns true if found
 539   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 540   // find field in direct superinterfaces, returns the interface in which the field is defined
 541   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 542   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 543   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 544   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 545   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 546 
 547   // find a non-static or static field given its offset within the class.
 548   bool contains_field_offset(int offset) {
 549     return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
 550   }
 551 
 552   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 553   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 554 
 555   // find a local method (returns NULL if not found)
 556   Method* find_method(const Symbol* name, const Symbol* signature) const;
 557   static Method* find_method(const Array<Method*>* methods,
 558                              const Symbol* name,
 559                              const Symbol* signature);
 560 
 561   // find a local method, but skip static methods
 562   Method* find_instance_method(const Symbol* name, const Symbol* signature) const;
 563   static Method* find_instance_method(const Array<Method*>* methods,
 564                                       const Symbol* name,
 565                                       const Symbol* signature);
 566 
 567   // find a local method (returns NULL if not found)
 568   Method* find_local_method(const Symbol* name,
 569                             const Symbol* signature,
 570                             OverpassLookupMode overpass_mode,
 571                             StaticLookupMode static_mode,
 572                             PrivateLookupMode private_mode) const;
 573 
 574   // find a local method from given methods array (returns NULL if not found)
 575   static Method* find_local_method(const Array<Method*>* methods,
 576                                    const Symbol* name,
 577                                    const Symbol* signature,
 578                                    OverpassLookupMode overpass_mode,
 579                                    StaticLookupMode static_mode,
 580                                    PrivateLookupMode private_mode);
 581 
 582   // find a local method index in methods or default_methods (returns -1 if not found)
 583   static int find_method_index(const Array<Method*>* methods,
 584                                const Symbol* name,
 585                                const Symbol* signature,
 586                                OverpassLookupMode overpass_mode,
 587                                StaticLookupMode static_mode,
 588                                PrivateLookupMode private_mode);
 589 
 590   // lookup operation (returns NULL if not found)
 591   Method* uncached_lookup_method(const Symbol* name,
 592                                  const Symbol* signature,
 593                                  OverpassLookupMode overpass_mode) const;
 594 
 595   // lookup a method in all the interfaces that this class implements
 596   // (returns NULL if not found)
 597   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, DefaultsLookupMode defaults_mode) const;
 598 
 599   // lookup a method in local defaults then in all interfaces
 600   // (returns NULL if not found)
 601   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 602 
 603   // Find method indices by name.  If a method with the specified name is
 604   // found the index to the first method is returned, and 'end' is filled in
 605   // with the index of first non-name-matching method.  If no method is found
 606   // -1 is returned.
 607   int find_method_by_name(const Symbol* name, int* end) const;
 608   static int find_method_by_name(const Array<Method*>* methods,
 609                                  const Symbol* name, int* end);
 610 
 611   // constant pool
 612   ConstantPool* constants() const        { return _constants; }
 613   void set_constants(ConstantPool* c)    { _constants = c; }
 614 
 615   // protection domain
 616   oop protection_domain() const;
 617 
 618   // signers
 619   objArrayOop signers() const;
 620 
 621   // host class
 622   InstanceKlass* host_klass() const              {
 623     InstanceKlass** hk = adr_host_klass();
 624     if (hk == NULL) {
 625       return NULL;
 626     } else {
 627       assert(*hk != NULL, "host klass should always be set if the address is not null");
 628       return *hk;
 629     }
 630   }
 631   void set_host_klass(const InstanceKlass* host) {
 632     assert(is_anonymous(), "not anonymous");
 633     const InstanceKlass** addr = (const InstanceKlass **)adr_host_klass();
 634     assert(addr != NULL, "no reversed space");
 635     if (addr != NULL) {
 636       *addr = host;
 637     }
 638   }
 639   bool is_anonymous() const                {
 640     return (_misc_flags & _misc_is_anonymous) != 0;
 641   }
 642   void set_is_anonymous(bool value)        {
 643     if (value) {
 644       _misc_flags |= _misc_is_anonymous;
 645     } else {
 646       _misc_flags &= ~_misc_is_anonymous;
 647     }
 648   }
 649 
 650   // Oop that keeps the metadata for this class from being unloaded
 651   // in places where the metadata is stored in other places, like nmethods
 652   oop klass_holder() const {
 653     return is_anonymous() ? java_mirror() : class_loader();
 654   }
 655 
 656   bool is_contended() const                {
 657     return (_misc_flags & _misc_is_contended) != 0;
 658   }
 659   void set_is_contended(bool value)        {
 660     if (value) {
 661       _misc_flags |= _misc_is_contended;
 662     } else {
 663       _misc_flags &= ~_misc_is_contended;
 664     }
 665   }
 666 
 667   // source file name
 668   Symbol* source_file_name() const               {
 669     return (_source_file_name_index == 0) ?
 670       (Symbol*)NULL : _constants->symbol_at(_source_file_name_index);
 671   }
 672   u2 source_file_name_index() const              {
 673     return _source_file_name_index;
 674   }
 675   void set_source_file_name_index(u2 sourcefile_index) {
 676     _source_file_name_index = sourcefile_index;
 677   }
 678 
 679   // minor and major version numbers of class file
 680   u2 minor_version() const                 { return _minor_version; }
 681   void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
 682   u2 major_version() const                 { return _major_version; }
 683   void set_major_version(u2 major_version) { _major_version = major_version; }
 684 
 685   // source debug extension
 686   const char* source_debug_extension() const { return _source_debug_extension; }
 687   void set_source_debug_extension(const char* array, int length);
 688 
 689   // symbol unloading support (refcount already added)
 690   Symbol* array_name()                     { return _array_name; }
 691   void set_array_name(Symbol* name)        { assert(_array_name == NULL  || name == NULL, "name already created"); _array_name = name; }
 692 
 693   // nonstatic oop-map blocks
 694   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 695     return oop_map_count * OopMapBlock::size_in_words();
 696   }
 697   unsigned int nonstatic_oop_map_count() const {
 698     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 699   }
 700   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 701   void set_nonstatic_oop_map_size(int words) {
 702     _nonstatic_oop_map_size = words;
 703   }
 704 
 705 #if INCLUDE_JVMTI
 706   // Redefinition locking.  Class can only be redefined by one thread at a time.
 707   bool is_being_redefined() const          { return _is_being_redefined; }
 708   void set_is_being_redefined(bool value)  { _is_being_redefined = value; }
 709 
 710   // RedefineClasses() support for previous versions:
 711   void add_previous_version(instanceKlassHandle ikh, int emcp_method_count);
 712   void purge_previous_version_list();
 713 
 714   InstanceKlass* previous_versions() const { return _previous_versions; }
 715 #else
 716   InstanceKlass* previous_versions() const { return NULL; }
 717 #endif
 718 
 719   InstanceKlass* get_klass_version(int version) {
 720     for (InstanceKlass* ik = this; ik != NULL; ik = ik->previous_versions()) {
 721       if (ik->constants()->version() == version) {
 722         return ik;
 723       }
 724     }
 725     return NULL;
 726   }
 727 
 728   bool has_been_redefined() const {
 729     return (_misc_flags & _misc_has_been_redefined) != 0;
 730   }
 731   void set_has_been_redefined() {
 732     _misc_flags |= _misc_has_been_redefined;
 733   }
 734 
 735   bool is_scratch_class() const {
 736     return (_misc_flags & _misc_is_scratch_class) != 0;
 737   }
 738 
 739   void set_is_scratch_class() {
 740     _misc_flags |= _misc_is_scratch_class;
 741   }
 742 
 743 private:
 744 
 745   void set_kind(unsigned kind) {
 746     assert(kind <= _misc_kind_field_mask, "Invalid InstanceKlass kind");
 747     unsigned fmask = _misc_kind_field_mask << _misc_kind_field_pos;
 748     unsigned flags = _misc_flags & ~fmask;
 749     _misc_flags = (flags | (kind << _misc_kind_field_pos));
 750   }
 751 
 752   bool is_kind(unsigned desired) const {
 753     unsigned kind = (_misc_flags >> _misc_kind_field_pos) & _misc_kind_field_mask;
 754     return kind == desired;
 755   }
 756 
 757 public:
 758 
 759   // Other is anything that is not one of the more specialized kinds of InstanceKlass.
 760   bool is_other_instance_klass() const        { return is_kind(_misc_kind_other); }
 761   bool is_reference_instance_klass() const    { return is_kind(_misc_kind_reference); }
 762   bool is_mirror_instance_klass() const       { return is_kind(_misc_kind_mirror); }
 763   bool is_class_loader_instance_klass() const { return is_kind(_misc_kind_class_loader); }
 764 
 765 #if INCLUDE_JVMTI
 766 
 767   void init_previous_versions() {
 768     _previous_versions = NULL;
 769   }
 770 
 771  private:
 772   static bool  _has_previous_versions;
 773  public:
 774   static void purge_previous_versions(InstanceKlass* ik) {
 775     if (ik->has_been_redefined()) {
 776       ik->purge_previous_version_list();
 777     }
 778   }
 779 
 780   static bool has_previous_versions_and_reset();
 781 
 782   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 783   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 784     _cached_class_file = data;
 785   }
 786   JvmtiCachedClassFileData * get_cached_class_file();
 787   jint get_cached_class_file_len();
 788   unsigned char * get_cached_class_file_bytes();
 789 
 790   // JVMTI: Support for caching of field indices, types, and offsets
 791   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 792     _jvmti_cached_class_field_map = descriptor;
 793   }
 794   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 795     return _jvmti_cached_class_field_map;
 796   }
 797 
 798 #if INCLUDE_CDS
 799   void set_archived_class_data(JvmtiCachedClassFileData* data) {
 800     _cached_class_file = data;
 801   }
 802 
 803   JvmtiCachedClassFileData * get_archived_class_data();
 804 #endif // INCLUDE_CDS
 805 #else // INCLUDE_JVMTI
 806 
 807   static void purge_previous_versions(InstanceKlass* ik) { return; };
 808   static bool has_previous_versions_and_reset() { return false; }
 809 
 810   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 811     assert(data == NULL, "unexpected call with JVMTI disabled");
 812   }
 813   JvmtiCachedClassFileData * get_cached_class_file() { return (JvmtiCachedClassFileData *)NULL; }
 814 
 815 #endif // INCLUDE_JVMTI
 816 
 817   bool has_nonstatic_concrete_methods() const {
 818     return (_misc_flags & _misc_has_nonstatic_concrete_methods) != 0;
 819   }
 820   void set_has_nonstatic_concrete_methods(bool b) {
 821     if (b) {
 822       _misc_flags |= _misc_has_nonstatic_concrete_methods;
 823     } else {
 824       _misc_flags &= ~_misc_has_nonstatic_concrete_methods;
 825     }
 826   }
 827 
 828   bool declares_nonstatic_concrete_methods() const {
 829     return (_misc_flags & _misc_declares_nonstatic_concrete_methods) != 0;
 830   }
 831   void set_declares_nonstatic_concrete_methods(bool b) {
 832     if (b) {
 833       _misc_flags |= _misc_declares_nonstatic_concrete_methods;
 834     } else {
 835       _misc_flags &= ~_misc_declares_nonstatic_concrete_methods;
 836     }
 837   }
 838 
 839   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 840   inline u2 next_method_idnum();
 841   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 842 
 843   // generics support
 844   Symbol* generic_signature() const                   {
 845     return (_generic_signature_index == 0) ?
 846       (Symbol*)NULL : _constants->symbol_at(_generic_signature_index);
 847   }
 848   u2 generic_signature_index() const                  {
 849     return _generic_signature_index;
 850   }
 851   void set_generic_signature_index(u2 sig_index)      {
 852     _generic_signature_index = sig_index;
 853   }
 854 
 855   u2 enclosing_method_data(int offset) const;
 856   u2 enclosing_method_class_index() const {
 857     return enclosing_method_data(enclosing_method_class_index_offset);
 858   }
 859   u2 enclosing_method_method_index() {
 860     return enclosing_method_data(enclosing_method_method_index_offset);
 861   }
 862   void set_enclosing_method_indices(u2 class_index,
 863                                     u2 method_index);
 864 
 865   // jmethodID support
 866   static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
 867                      const methodHandle& method_h);
 868   static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
 869                      size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
 870                      jmethodID* to_dealloc_id_p,
 871                      jmethodID** to_dealloc_jmeths_p);
 872   static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
 873                 size_t *length_p, jmethodID* id_p);
 874   void ensure_space_for_methodids(int start_offset = 0);
 875   jmethodID jmethod_id_or_null(Method* method);
 876 
 877   // annotations support
 878   Annotations* annotations() const          { return _annotations; }
 879   void set_annotations(Annotations* anno)   { _annotations = anno; }
 880 
 881   AnnotationArray* class_annotations() const {
 882     return (_annotations != NULL) ? _annotations->class_annotations() : NULL;
 883   }
 884   Array<AnnotationArray*>* fields_annotations() const {
 885     return (_annotations != NULL) ? _annotations->fields_annotations() : NULL;
 886   }
 887   AnnotationArray* class_type_annotations() const {
 888     return (_annotations != NULL) ? _annotations->class_type_annotations() : NULL;
 889   }
 890   Array<AnnotationArray*>* fields_type_annotations() const {
 891     return (_annotations != NULL) ? _annotations->fields_type_annotations() : NULL;
 892   }
 893   // allocation
 894   instanceOop allocate_instance(TRAPS);
 895 
 896   // additional member function to return a handle
 897   instanceHandle allocate_instance_handle(TRAPS)      { return instanceHandle(THREAD, allocate_instance(THREAD)); }
 898 
 899   objArrayOop allocate_objArray(int n, int length, TRAPS);
 900   // Helper function
 901   static instanceOop register_finalizer(instanceOop i, TRAPS);
 902 
 903   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 904   // if not, throw either an Error or an Exception.
 905   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 906 
 907   // initialization
 908   void call_class_initializer(TRAPS);
 909   void set_initialization_state_and_notify(ClassState state, TRAPS);
 910 
 911   // OopMapCache support
 912   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 913   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 914   void mask_for(const methodHandle& method, int bci, InterpreterOopMap* entry);
 915 
 916   // JNI identifier support (for static fields - for jni performance)
 917   JNIid* jni_ids()                               { return _jni_ids; }
 918   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 919   JNIid* jni_id_for(int offset);
 920 
 921   // maintenance of deoptimization dependencies
 922   inline DependencyContext dependencies();
 923   int  mark_dependent_nmethods(KlassDepChange& changes);
 924   void add_dependent_nmethod(nmethod* nm);
 925   void remove_dependent_nmethod(nmethod* nm, bool delete_immediately);
 926 
 927   // On-stack replacement support
 928   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 929   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 930   void add_osr_nmethod(nmethod* n);
 931   bool remove_osr_nmethod(nmethod* n);
 932   int mark_osr_nmethods(const Method* m);
 933   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 934 
 935 #if INCLUDE_JVMTI
 936   // Breakpoint support (see methods on Method* for details)
 937   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 938   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 939 #endif
 940 
 941   // support for stub routines
 942   static ByteSize init_state_offset()  { return in_ByteSize(offset_of(InstanceKlass, _init_state)); }
 943   TRACE_DEFINE_KLASS_TRACE_ID_OFFSET;
 944   static ByteSize init_thread_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_thread)); }
 945 
 946   // subclass/subinterface checks
 947   bool implements_interface(Klass* k) const;
 948   bool is_same_or_direct_interface(Klass* k) const;
 949 
 950 #ifdef ASSERT
 951   // check whether this class or one of its superclasses was redefined
 952   bool has_redefined_this_or_super() const;
 953 #endif
 954 
 955   // Access to the implementor of an interface.
 956   Klass* implementor() const
 957   {
 958     Klass** k = adr_implementor();
 959     if (k == NULL) {
 960       return NULL;
 961     } else {
 962       return *k;
 963     }
 964   }
 965 
 966   void set_implementor(Klass* k) {
 967     assert(is_interface(), "not interface");
 968     Klass** addr = adr_implementor();
 969     assert(addr != NULL, "null addr");
 970     if (addr != NULL) {
 971       *addr = k;
 972     }
 973   }
 974 
 975   int  nof_implementors() const       {
 976     Klass* k = implementor();
 977     if (k == NULL) {
 978       return 0;
 979     } else if (k != this) {
 980       return 1;
 981     } else {
 982       return 2;
 983     }
 984   }
 985 
 986   void add_implementor(Klass* k);  // k is a new class that implements this interface
 987   void init_implementor();           // initialize
 988 
 989   // link this class into the implementors list of every interface it implements
 990   void process_interfaces(Thread *thread);
 991 
 992   // virtual operations from Klass
 993   bool is_leaf_class() const               { return _subklass == NULL; }
 994   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
 995   bool compute_is_subtype_of(Klass* k);
 996   bool can_be_primary_super_slow() const;
 997   int oop_size(oop obj)  const             { return size_helper(); }
 998   // slow because it's a virtual call and used for verifying the layout_helper.
 999   // Using the layout_helper bits, we can call is_instance_klass without a virtual call.
1000   DEBUG_ONLY(bool is_instance_klass_slow() const      { return true; })
1001 
1002   // Iterators
1003   void do_local_static_fields(FieldClosure* cl);
1004   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
1005   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
1006 
1007   void methods_do(void f(Method* method));
1008   void array_klasses_do(void f(Klass* k));
1009   void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
1010   bool super_types_do(SuperTypeClosure* blk);
1011 
1012   static InstanceKlass* cast(Klass* k) {
1013     return const_cast<InstanceKlass*>(cast(const_cast<const Klass*>(k)));
1014   }
1015 
1016   static const InstanceKlass* cast(const Klass* k) {
1017     assert(k != NULL, "k should not be null");
1018     assert(k->is_instance_klass(), "cast to InstanceKlass");
1019     return static_cast<const InstanceKlass*>(k);
1020   }
1021 
1022   InstanceKlass* java_super() const {
1023     return (super() == NULL) ? NULL : cast(super());
1024   }
1025 
1026   // Sizing (in words)
1027   static int header_size()            { return sizeof(InstanceKlass)/wordSize; }
1028 
1029   static int size(int vtable_length, int itable_length,
1030                   int nonstatic_oop_map_size,
1031                   bool is_interface, bool is_anonymous) {
1032     return align_metadata_size(header_size() +
1033            vtable_length +
1034            itable_length +
1035            nonstatic_oop_map_size +
1036            (is_interface ? (int)sizeof(Klass*)/wordSize : 0) +
1037            (is_anonymous ? (int)sizeof(Klass*)/wordSize : 0));
1038   }
1039   int size() const                    { return size(vtable_length(),
1040                                                itable_length(),
1041                                                nonstatic_oop_map_size(),
1042                                                is_interface(),
1043                                                is_anonymous());
1044   }
1045 #if INCLUDE_SERVICES
1046   virtual void collect_statistics(KlassSizeStats *sz) const;
1047 #endif
1048 
1049   intptr_t* start_of_itable()   const { return (intptr_t*)start_of_vtable() + vtable_length(); }
1050   intptr_t* end_of_itable()     const { return start_of_itable() + itable_length(); }
1051 
1052   int  itable_offset_in_words() const { return start_of_itable() - (intptr_t*)this; }
1053 
1054   address static_field_addr(int offset);
1055 
1056   OopMapBlock* start_of_nonstatic_oop_maps() const {
1057     return (OopMapBlock*)(start_of_itable() + itable_length());
1058   }
1059 
1060   Klass** end_of_nonstatic_oop_maps() const {
1061     return (Klass**)(start_of_nonstatic_oop_maps() +
1062                      nonstatic_oop_map_count());
1063   }
1064 
1065   Klass** adr_implementor() const {
1066     if (is_interface()) {
1067       return (Klass**)end_of_nonstatic_oop_maps();
1068     } else {
1069       return NULL;
1070     }
1071   };
1072 
1073   InstanceKlass** adr_host_klass() const {
1074     if (is_anonymous()) {
1075       InstanceKlass** adr_impl = (InstanceKlass **)adr_implementor();
1076       if (adr_impl != NULL) {
1077         return adr_impl + 1;
1078       } else {
1079         return (InstanceKlass **)end_of_nonstatic_oop_maps();
1080       }
1081     } else {
1082       return NULL;
1083     }
1084   }
1085 
1086   // Use this to return the size of an instance in heap words:
1087   int size_helper() const {
1088     return layout_helper_to_size_helper(layout_helper());
1089   }
1090 
1091   // This bit is initialized in classFileParser.cpp.
1092   // It is false under any of the following conditions:
1093   //  - the class is abstract (including any interface)
1094   //  - the class has a finalizer (if !RegisterFinalizersAtInit)
1095   //  - the class size is larger than FastAllocateSizeLimit
1096   //  - the class is java/lang/Class, which cannot be allocated directly
1097   bool can_be_fastpath_allocated() const {
1098     return !layout_helper_needs_slow_path(layout_helper());
1099   }
1100 
1101   // Java itable
1102   klassItable* itable() const;        // return new klassItable wrapper
1103   Method* method_at_itable(Klass* holder, int index, TRAPS);
1104 
1105 #if INCLUDE_JVMTI
1106   void adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed);
1107 #endif // INCLUDE_JVMTI
1108 
1109   void clean_weak_instanceklass_links(BoolObjectClosure* is_alive);
1110   void clean_implementors_list(BoolObjectClosure* is_alive);
1111   void clean_method_data(BoolObjectClosure* is_alive);
1112 
1113   // Explicit metaspace deallocation of fields
1114   // For RedefineClasses and class file parsing errors, we need to deallocate
1115   // instanceKlasses and the metadata they point to.
1116   void deallocate_contents(ClassLoaderData* loader_data);
1117   static void deallocate_methods(ClassLoaderData* loader_data,
1118                                  Array<Method*>* methods);
1119   void static deallocate_interfaces(ClassLoaderData* loader_data,
1120                                     const Klass* super_klass,
1121                                     Array<Klass*>* local_interfaces,
1122                                     Array<Klass*>* transitive_interfaces);
1123 
1124   // The constant pool is on stack if any of the methods are executing or
1125   // referenced by handles.
1126   bool on_stack() const { return _constants->on_stack(); }
1127 
1128   // callbacks for actions during class unloading
1129   static void notify_unload_class(InstanceKlass* ik);
1130   static void release_C_heap_structures(InstanceKlass* ik);
1131 
1132   // Naming
1133   const char* signature_name() const;
1134   static Symbol* package_from_name(const Symbol* name, TRAPS);
1135 
1136   // GC specific object visitors
1137   //
1138   // Mark Sweep
1139   int  oop_ms_adjust_pointers(oop obj);
1140 #if INCLUDE_ALL_GCS
1141   // Parallel Scavenge
1142   void oop_ps_push_contents(  oop obj, PSPromotionManager* pm);
1143   // Parallel Compact
1144   void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
1145   void oop_pc_update_pointers(oop obj, ParCompactionManager* cm);
1146 #endif
1147 
1148   // Oop fields (and metadata) iterators
1149   //  [nv = true]  Use non-virtual calls to do_oop_nv.
1150   //  [nv = false] Use virtual calls to do_oop.
1151   //
1152   // The InstanceKlass iterators also visits the Object's klass.
1153 
1154   // Forward iteration
1155  public:
1156   // Iterate over all oop fields in the oop maps.
1157   template <bool nv, class OopClosureType>
1158   inline void oop_oop_iterate_oop_maps(oop obj, OopClosureType* closure);
1159 
1160  protected:
1161   // Iterate over all oop fields and metadata.
1162   template <bool nv, class OopClosureType>
1163   inline int oop_oop_iterate(oop obj, OopClosureType* closure);
1164 
1165  private:
1166   // Iterate over all oop fields in the oop maps.
1167   // Specialized for [T = oop] or [T = narrowOop].
1168   template <bool nv, typename T, class OopClosureType>
1169   inline void oop_oop_iterate_oop_maps_specialized(oop obj, OopClosureType* closure);
1170 
1171   // Iterate over all oop fields in one oop map.
1172   template <bool nv, typename T, class OopClosureType>
1173   inline void oop_oop_iterate_oop_map(OopMapBlock* map, oop obj, OopClosureType* closure);
1174 
1175 
1176   // Reverse iteration
1177 #if INCLUDE_ALL_GCS
1178  public:
1179   // Iterate over all oop fields in the oop maps.
1180   template <bool nv, class OopClosureType>
1181   inline void oop_oop_iterate_oop_maps_reverse(oop obj, OopClosureType* closure);
1182 
1183  protected:
1184   // Iterate over all oop fields and metadata.
1185   template <bool nv, class OopClosureType>
1186   inline int oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
1187 
1188  private:
1189   // Iterate over all oop fields in the oop maps.
1190   // Specialized for [T = oop] or [T = narrowOop].
1191   template <bool nv, typename T, class OopClosureType>
1192   inline void oop_oop_iterate_oop_maps_specialized_reverse(oop obj, OopClosureType* closure);
1193 
1194   // Iterate over all oop fields in one oop map.
1195   template <bool nv, typename T, class OopClosureType>
1196   inline void oop_oop_iterate_oop_map_reverse(OopMapBlock* map, oop obj, OopClosureType* closure);
1197 #endif
1198 
1199 
1200   // Bounded range iteration
1201  public:
1202   // Iterate over all oop fields in the oop maps.
1203   template <bool nv, class OopClosureType>
1204   inline void oop_oop_iterate_oop_maps_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1205 
1206  protected:
1207   // Iterate over all oop fields and metadata.
1208   template <bool nv, class OopClosureType>
1209   inline int oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1210 
1211  private:
1212   // Iterate over all oop fields in the oop maps.
1213   // Specialized for [T = oop] or [T = narrowOop].
1214   template <bool nv, typename T, class OopClosureType>
1215   inline void oop_oop_iterate_oop_maps_specialized_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1216 
1217   // Iterate over all oop fields in one oop map.
1218   template <bool nv, typename T, class OopClosureType>
1219   inline void oop_oop_iterate_oop_map_bounded(OopMapBlock* map, oop obj, OopClosureType* closure, MemRegion mr);
1220 
1221 
1222  public:
1223 
1224   ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL)
1225   ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL)
1226 
1227 #if INCLUDE_ALL_GCS
1228   ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL_BACKWARDS)
1229   ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL_BACKWARDS)
1230 #endif // INCLUDE_ALL_GCS
1231 
1232   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
1233 
1234 public:
1235   void set_in_error_state() {
1236     assert(DumpSharedSpaces, "only call this when dumping archive");
1237     _init_state = initialization_error;
1238   }
1239   bool check_sharing_error_state();
1240 
1241 private:
1242   // initialization state
1243 #ifdef ASSERT
1244   void set_init_state(ClassState state);
1245 #else
1246   void set_init_state(ClassState state) { _init_state = (u1)state; }
1247 #endif
1248   void set_rewritten()                  { _misc_flags |= _misc_rewritten; }
1249   void set_init_thread(Thread *thread)  { _init_thread = thread; }
1250 
1251   // The RedefineClasses() API can cause new method idnums to be needed
1252   // which will cause the caches to grow. Safety requires different
1253   // cache management logic if the caches can grow instead of just
1254   // going from NULL to non-NULL.
1255   bool idnum_can_increment() const      { return has_been_redefined(); }
1256   inline jmethodID* methods_jmethod_ids_acquire() const;
1257   inline void release_set_methods_jmethod_ids(jmethodID* jmeths);
1258 
1259   // Lock during initialization
1260 public:
1261   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
1262   // Must be one per class and it has to be a VM internal object so java code
1263   // cannot lock it (like the mirror).
1264   // It has to be an object not a Mutex because it's held through java calls.
1265   oop init_lock() const;
1266 private:
1267   void fence_and_clear_init_lock();
1268 
1269   // Static methods that are used to implement member methods where an exposed this pointer
1270   // is needed due to possible GCs
1271   static bool link_class_impl                           (instanceKlassHandle this_k, bool throw_verifyerror, TRAPS);
1272   static bool verify_code                               (instanceKlassHandle this_k, bool throw_verifyerror, TRAPS);
1273   static void initialize_impl                           (instanceKlassHandle this_k, TRAPS);
1274   static void initialize_super_interfaces               (instanceKlassHandle this_k, TRAPS);
1275   static void eager_initialize_impl                     (instanceKlassHandle this_k);
1276   static void set_initialization_state_and_notify_impl  (instanceKlassHandle this_k, ClassState state, TRAPS);
1277   static void call_class_initializer_impl               (instanceKlassHandle this_k, TRAPS);
1278   static Klass* array_klass_impl                        (instanceKlassHandle this_k, bool or_null, int n, TRAPS);
1279   static void do_local_static_fields_impl               (instanceKlassHandle this_k, void f(fieldDescriptor* fd, Handle, TRAPS), Handle, TRAPS);
1280   /* jni_id_for_impl for jfieldID only */
1281   static JNIid* jni_id_for_impl                         (instanceKlassHandle this_k, int offset);
1282 
1283   // Returns the array class for the n'th dimension
1284   Klass* array_klass_impl(bool or_null, int n, TRAPS);
1285 
1286   // Returns the array class with this class as element type
1287   Klass* array_klass_impl(bool or_null, TRAPS);
1288 
1289   // find a local method (returns NULL if not found)
1290   Method* find_method_impl(const Symbol* name,
1291                            const Symbol* signature,
1292                            OverpassLookupMode overpass_mode,
1293                            StaticLookupMode static_mode,
1294                            PrivateLookupMode private_mode) const;
1295 
1296   static Method* find_method_impl(const Array<Method*>* methods,
1297                                   const Symbol* name,
1298                                   const Symbol* signature,
1299                                   OverpassLookupMode overpass_mode,
1300                                   StaticLookupMode static_mode,
1301                                   PrivateLookupMode private_mode);
1302 
1303   // Free CHeap allocated fields.
1304   void release_C_heap_structures();
1305 
1306 #if INCLUDE_JVMTI
1307   // RedefineClasses support
1308   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1309   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1310 #endif
1311 public:
1312   // CDS support - remove and restore oops from metadata. Oops are not shared.
1313   virtual void remove_unshareable_info();
1314   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
1315 
1316   // jvm support
1317   jint compute_modifier_flags(TRAPS) const;
1318 
1319   // JSR-292 support
1320   MemberNameTable* member_names() { return _member_names; }
1321   void set_member_names(MemberNameTable* member_names) { _member_names = member_names; }
1322   bool add_member_name(Handle member_name);
1323 
1324 public:
1325   // JVMTI support
1326   jint jvmti_class_status() const;
1327 
1328  public:
1329   // Printing
1330 #ifndef PRODUCT
1331   void print_on(outputStream* st) const;
1332 #endif
1333   void print_value_on(outputStream* st) const;
1334 
1335   void oop_print_value_on(oop obj, outputStream* st);
1336 
1337 #ifndef PRODUCT
1338   void oop_print_on      (oop obj, outputStream* st);
1339 
1340   void print_dependent_nmethods(bool verbose = false);
1341   bool is_dependent_nmethod(nmethod* nm);
1342 #endif
1343 
1344   const char* internal_name() const;
1345 
1346   // Verification
1347   void verify_on(outputStream* st);
1348 
1349   void oop_verify_on(oop obj, outputStream* st);
1350 
1351   // Logging
1352   void print_loading_log(LogLevel::type type, ClassLoaderData* loader_data,
1353                          const char* module_name, const ClassFileStream* cfs) const;
1354 };
1355 
1356 // for adding methods
1357 // UNSET_IDNUM return means no more ids available
1358 inline u2 InstanceKlass::next_method_idnum() {
1359   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1360     return ConstMethod::UNSET_IDNUM; // no more ids available
1361   } else {
1362     return _idnum_allocated_count++;
1363   }
1364 }
1365 
1366 
1367 /* JNIid class for jfieldIDs only */
1368 class JNIid: public CHeapObj<mtClass> {
1369   friend class VMStructs;
1370  private:
1371   Klass*             _holder;
1372   JNIid*             _next;
1373   int                _offset;
1374 #ifdef ASSERT
1375   bool               _is_static_field_id;
1376 #endif
1377 
1378  public:
1379   // Accessors
1380   Klass* holder() const           { return _holder; }
1381   int offset() const              { return _offset; }
1382   JNIid* next()                   { return _next; }
1383   // Constructor
1384   JNIid(Klass* holder, int offset, JNIid* next);
1385   // Identifier lookup
1386   JNIid* find(int offset);
1387 
1388   bool find_local_field(fieldDescriptor* fd) {
1389     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1390   }
1391 
1392   static void deallocate(JNIid* id);
1393   // Debugging
1394 #ifdef ASSERT
1395   bool is_static_field_id() const { return _is_static_field_id; }
1396   void set_is_static_field_id()   { _is_static_field_id = true; }
1397 #endif
1398   void verify(Klass* holder);
1399 };
1400 
1401 // An iterator that's used to access the inner classes indices in the
1402 // InstanceKlass::_inner_classes array.
1403 class InnerClassesIterator : public StackObj {
1404  private:
1405   Array<jushort>* _inner_classes;
1406   int _length;
1407   int _idx;
1408  public:
1409 
1410   InnerClassesIterator(instanceKlassHandle k) {
1411     _inner_classes = k->inner_classes();
1412     if (k->inner_classes() != NULL) {
1413       _length = _inner_classes->length();
1414       // The inner class array's length should be the multiple of
1415       // inner_class_next_offset if it only contains the InnerClasses
1416       // attribute data, or it should be
1417       // n*inner_class_next_offset+enclosing_method_attribute_size
1418       // if it also contains the EnclosingMethod data.
1419       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1420               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1421              "just checking");
1422       // Remove the enclosing_method portion if exists.
1423       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1424         _length -= InstanceKlass::enclosing_method_attribute_size;
1425       }
1426     } else {
1427       _length = 0;
1428     }
1429     _idx = 0;
1430   }
1431 
1432   int length() const {
1433     return _length;
1434   }
1435 
1436   void next() {
1437     _idx += InstanceKlass::inner_class_next_offset;
1438   }
1439 
1440   bool done() const {
1441     return (_idx >= _length);
1442   }
1443 
1444   u2 inner_class_info_index() const {
1445     return _inner_classes->at(
1446                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1447   }
1448 
1449   void set_inner_class_info_index(u2 index) {
1450     _inner_classes->at_put(
1451                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1452   }
1453 
1454   u2 outer_class_info_index() const {
1455     return _inner_classes->at(
1456                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1457   }
1458 
1459   void set_outer_class_info_index(u2 index) {
1460     _inner_classes->at_put(
1461                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1462   }
1463 
1464   u2 inner_name_index() const {
1465     return _inner_classes->at(
1466                _idx + InstanceKlass::inner_class_inner_name_offset);
1467   }
1468 
1469   void set_inner_name_index(u2 index) {
1470     _inner_classes->at_put(
1471                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1472   }
1473 
1474   u2 inner_access_flags() const {
1475     return _inner_classes->at(
1476                _idx + InstanceKlass::inner_class_access_flags_offset);
1477   }
1478 };
1479 
1480 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP