1 /*
   2  * Copyright (c) 1997, 2014, 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/classLoaderData.hpp"
  29 #include "memory/referenceType.hpp"
  30 #include "oops/annotations.hpp"
  31 #include "oops/constMethod.hpp"
  32 #include "oops/fieldInfo.hpp"
  33 #include "oops/instanceOop.hpp"
  34 #include "oops/klassVtable.hpp"
  35 #include "runtime/atomic.hpp"
  36 #include "runtime/handles.hpp"
  37 #include "runtime/os.hpp"
  38 #include "utilities/accessFlags.hpp"
  39 #include "utilities/bitMap.inline.hpp"
  40 #include "utilities/macros.hpp"
  41 #include "trace/traceMacros.hpp"
  42 
  43 // An InstanceKlass is the VM level representation of a Java class.
  44 // It contains all information needed for at class at execution runtime.
  45 
  46 //  InstanceKlass embedded field layout (after declared fields):
  47 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  48 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  49 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  50 //      indicating where oops are located in instances of this klass.
  51 //    [EMBEDDED implementor of the interface] only exist for interface
  52 //    [EMBEDDED host klass        ] only exist for an anonymous class (JSR 292 enabled)
  53 
  54 
  55 // forward declaration for class -- see below for definition
  56 class SuperTypeClosure;
  57 class JNIid;
  58 class jniIdMapBase;
  59 class BreakpointInfo;
  60 class fieldDescriptor;
  61 class DepChange;
  62 class nmethodBucket;
  63 class PreviousVersionNode;
  64 class JvmtiCachedClassFieldMap;
  65 class MemberNameTable;
  66 
  67 // This is used in iterators below.
  68 class FieldClosure: public StackObj {
  69 public:
  70   virtual void do_field(fieldDescriptor* fd) = 0;
  71 };
  72 
  73 #ifndef PRODUCT
  74 // Print fields.
  75 // If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.
  76 class FieldPrinter: public FieldClosure {
  77    oop _obj;
  78    outputStream* _st;
  79  public:
  80    FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}
  81    void do_field(fieldDescriptor* fd);
  82 };
  83 #endif  // !PRODUCT
  84 
  85 // ValueObjs embedded in klass. Describes where oops are located in instances of
  86 // this klass.
  87 class OopMapBlock VALUE_OBJ_CLASS_SPEC {
  88  public:
  89   // Byte offset of the first oop mapped by this block.
  90   int offset() const          { return _offset; }
  91   void set_offset(int offset) { _offset = offset; }
  92 
  93   // Number of oops in this block.
  94   uint count() const         { return _count; }
  95   void set_count(uint count) { _count = count; }
  96 
  97   // sizeof(OopMapBlock) in HeapWords.
  98   static const int size_in_words() {
  99     return align_size_up(int(sizeof(OopMapBlock)), HeapWordSize) >>
 100       LogHeapWordSize;
 101   }
 102 
 103  private:
 104   int  _offset;
 105   uint _count;
 106 };
 107 
 108 struct JvmtiCachedClassFileData;
 109 
 110 class InstanceKlass: public Klass {
 111   friend class VMStructs;
 112   friend class ClassFileParser;
 113   friend class CompileReplay;
 114 
 115  protected:
 116   // Constructor
 117   InstanceKlass(int vtable_len,
 118                 int itable_len,
 119                 int static_field_size,
 120                 int nonstatic_oop_map_size,
 121                 ReferenceType rt,
 122                 AccessFlags access_flags,
 123                 bool is_anonymous);
 124  public:
 125   static InstanceKlass* allocate_instance_klass(
 126                                           ClassLoaderData* loader_data,
 127                                           int vtable_len,
 128                                           int itable_len,
 129                                           int static_field_size,
 130                                           int nonstatic_oop_map_size,
 131                                           ReferenceType rt,
 132                                           AccessFlags access_flags,
 133                                           Symbol* name,
 134                                           Klass* super_klass,
 135                                           bool is_anonymous,
 136                                           TRAPS);
 137 
 138   InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
 139 
 140   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 141   // of the class loading & initialization procedure, and the use of the states.
 142   enum ClassState {
 143     allocated,                          // allocated (but not yet linked)
 144     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 145     linked,                             // successfully linked/verified (but not initialized yet)
 146     being_initialized,                  // currently running class initializer
 147     fully_initialized,                  // initialized (successfull final state)
 148     initialization_error                // error happened during initialization
 149   };
 150 
 151   static int number_of_instance_classes() { return _total_instanceKlass_count; }
 152 
 153  private:
 154   static volatile int _total_instanceKlass_count;
 155 
 156  protected:
 157   // Annotations for this class
 158   Annotations*    _annotations;
 159   // Array classes holding elements of this class.
 160   Klass*          _array_klasses;
 161   // Constant pool for this class.
 162   ConstantPool* _constants;
 163   // The InnerClasses attribute and EnclosingMethod attribute. The
 164   // _inner_classes is an array of shorts. If the class has InnerClasses
 165   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 166   // [inner_class_info_index, outer_class_info_index,
 167   // inner_name_index, inner_class_access_flags] for the InnerClasses
 168   // attribute. If the EnclosingMethod attribute exists, it occupies the
 169   // last two shorts [class_index, method_index] of the array. If only
 170   // the InnerClasses attribute exists, the _inner_classes array length is
 171   // number_of_inner_classes * 4. If the class has both InnerClasses
 172   // and EnclosingMethod attributes the _inner_classes array length is
 173   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 174   Array<jushort>* _inner_classes;
 175 
 176   // the source debug extension for this klass, NULL if not specified.
 177   // Specified as UTF-8 string without terminating zero byte in the classfile,
 178   // it is stored in the instanceklass as a NULL-terminated UTF-8 string
 179   char*           _source_debug_extension;
 180   // Array name derived from this class which needs unreferencing
 181   // if this class is unloaded.
 182   Symbol*         _array_name;
 183 
 184   // Number of heapOopSize words used by non-static fields in this klass
 185   // (including inherited fields but after header_size()).
 186   int             _nonstatic_field_size;
 187   int             _static_field_size;    // number words used by static fields (oop and non-oop) in this klass
 188   // Constant pool index to the utf8 entry of the Generic signature,
 189   // or 0 if none.
 190   u2              _generic_signature_index;
 191   // Constant pool index to the utf8 entry for the name of source file
 192   // containing this klass, 0 if not specified.
 193   u2              _source_file_name_index;
 194   u2              _static_oop_field_count;// number of static oop fields in this klass
 195   u2              _java_fields_count;    // The number of declared Java fields
 196   int             _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
 197 
 198   // _is_marked_dependent can be set concurrently, thus cannot be part of the
 199   // _misc_flags.
 200   bool            _is_marked_dependent;  // used for marking during flushing and deoptimization
 201 
 202   enum {
 203     _misc_rewritten            = 1 << 0, // methods rewritten.
 204     _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
 205     _misc_should_verify_class  = 1 << 2, // allow caching of preverification
 206     _misc_is_anonymous         = 1 << 3, // has embedded _host_klass field
 207     _misc_is_contended         = 1 << 4, // marked with contended annotation
 208     _misc_has_default_methods  = 1 << 5  // class/superclass/implemented interfaces has default methods
 209   };
 210   u2              _misc_flags;
 211   u2              _minor_version;        // minor version number of class file
 212   u2              _major_version;        // major version number of class file
 213   Thread*         _init_thread;          // Pointer to current thread doing initialization (to handle recusive initialization)
 214   int             _vtable_len;           // length of Java vtable (in words)
 215   int             _itable_len;           // length of Java itable (in words)
 216   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 217   MemberNameTable* _member_names;        // Member names
 218   JNIid*          _jni_ids;              // First JNI identifier for static fields in this class
 219   jmethodID*      _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or NULL if none
 220   nmethodBucket*  _dependencies;         // list of dependent nmethods
 221   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 222   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 223   // Array of interesting part(s) of the previous version(s) of this
 224   // InstanceKlass. See PreviousVersionWalker below.
 225   GrowableArray<PreviousVersionNode *>* _previous_versions;
 226   // JVMTI fields can be moved to their own structure - see 6315920
 227   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 228   JvmtiCachedClassFileData* _cached_class_file;
 229 
 230   volatile u2     _idnum_allocated_count;         // JNI/JVMTI: increments with the addition of methods, old ids don't change
 231 
 232   // Class states are defined as ClassState (see above).
 233   // Place the _init_state here to utilize the unused 2-byte after
 234   // _idnum_allocated_count.
 235   u1              _init_state;                    // state of class
 236   u1              _reference_type;                // reference type
 237 
 238   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 239 
 240   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 241 
 242   // Method array.
 243   Array<Method*>* _methods;
 244   // Default Method Array, concrete methods inherited from interfaces
 245   Array<Method*>* _default_methods;
 246   // Interface (Klass*s) this class declares locally to implement.
 247   Array<Klass*>* _local_interfaces;
 248   // Interface (Klass*s) this class implements transitively.
 249   Array<Klass*>* _transitive_interfaces;
 250   // Int array containing the original order of method in the class file (for JVMTI).
 251   Array<int>*     _method_ordering;
 252   // Int array containing the vtable_indices for default_methods
 253   // offset matches _default_methods offset
 254   Array<int>*     _default_vtable_indices;
 255 
 256   // Instance and static variable information, starts with 6-tuples of shorts
 257   // [access, name index, sig index, initval index, low_offset, high_offset]
 258   // for all fields, followed by the generic signature data at the end of
 259   // the array. Only fields with generic signature attributes have the generic
 260   // signature data set in the array. The fields array looks like following:
 261   //
 262   // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
 263   // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
 264   //      ...
 265   // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
 266   //     [generic signature index]
 267   //     [generic signature index]
 268   //     ...
 269   Array<u2>*      _fields;
 270 
 271   // embedded Java vtable follows here
 272   // embedded Java itables follows here
 273   // embedded static fields follows here
 274   // embedded nonstatic oop-map blocks follows here
 275   // embedded implementor of this interface follows here
 276   //   The embedded implementor only exists if the current klass is an
 277   //   iterface. The possible values of the implementor fall into following
 278   //   three cases:
 279   //     NULL: no implementor.
 280   //     A Klass* that's not itself: one implementor.
 281   //     Itself: more than one implementors.
 282   // embedded host klass follows here
 283   //   The embedded host klass only exists in an anonymous class for
 284   //   dynamic language support (JSR 292 enabled). The host class grants
 285   //   its access privileges to this class also. The host class is either
 286   //   named, or a previously loaded anonymous class. A non-anonymous class
 287   //   or an anonymous class loaded through normal classloading does not
 288   //   have this embedded field.
 289   //
 290 
 291   friend class SystemDictionary;
 292 
 293  public:
 294   bool has_nonstatic_fields() const        {
 295     return (_misc_flags & _misc_has_nonstatic_fields) != 0;
 296   }
 297   void set_has_nonstatic_fields(bool b)    {
 298     if (b) {
 299       _misc_flags |= _misc_has_nonstatic_fields;
 300     } else {
 301       _misc_flags &= ~_misc_has_nonstatic_fields;
 302     }
 303   }
 304 
 305   // field sizes
 306   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 307   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 308 
 309   int static_field_size() const            { return _static_field_size; }
 310   void set_static_field_size(int size)     { _static_field_size = size; }
 311 
 312   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 313   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 314 
 315   // Java vtable
 316   int  vtable_length() const               { return _vtable_len; }
 317   void set_vtable_length(int len)          { _vtable_len = len; }
 318 
 319   // Java itable
 320   int  itable_length() const               { return _itable_len; }
 321   void set_itable_length(int len)          { _itable_len = len; }
 322 
 323   // array klasses
 324   Klass* array_klasses() const             { return _array_klasses; }
 325   void set_array_klasses(Klass* k)         { _array_klasses = k; }
 326 
 327   // methods
 328   Array<Method*>* methods() const          { return _methods; }
 329   void set_methods(Array<Method*>* a)      { _methods = a; }
 330   Method* method_with_idnum(int idnum);
 331 
 332   // method ordering
 333   Array<int>* method_ordering() const     { return _method_ordering; }
 334   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 335   void copy_method_ordering(intArray* m, TRAPS);
 336 
 337   // default_methods
 338   Array<Method*>* default_methods() const  { return _default_methods; }
 339   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 340 
 341   // default method vtable_indices
 342   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 343   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 344   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 345 
 346   // interfaces
 347   Array<Klass*>* local_interfaces() const          { return _local_interfaces; }
 348   void set_local_interfaces(Array<Klass*>* a)      {
 349     guarantee(_local_interfaces == NULL || a == NULL, "Just checking");
 350     _local_interfaces = a; }
 351 
 352   Array<Klass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 353   void set_transitive_interfaces(Array<Klass*>* a) {
 354     guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");
 355     _transitive_interfaces = a;
 356   }
 357 
 358  private:
 359   friend class fieldDescriptor;
 360   FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
 361 
 362  public:
 363   int     field_offset      (int index) const { return field(index)->offset(); }
 364   int     field_access_flags(int index) const { return field(index)->access_flags(); }
 365   Symbol* field_name        (int index) const { return field(index)->name(constants()); }
 366   Symbol* field_signature   (int index) const { return field(index)->signature(constants()); }
 367 
 368   // Number of Java declared fields
 369   int java_fields_count() const           { return (int)_java_fields_count; }
 370 
 371   Array<u2>* fields() const            { return _fields; }
 372   void set_fields(Array<u2>* f, u2 java_fields_count) {
 373     guarantee(_fields == NULL || f == NULL, "Just checking");
 374     _fields = f;
 375     _java_fields_count = java_fields_count;
 376   }
 377 
 378   // inner classes
 379   Array<u2>* inner_classes() const       { return _inner_classes; }
 380   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 381 
 382   enum InnerClassAttributeOffset {
 383     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 384     inner_class_inner_class_info_offset = 0,
 385     inner_class_outer_class_info_offset = 1,
 386     inner_class_inner_name_offset = 2,
 387     inner_class_access_flags_offset = 3,
 388     inner_class_next_offset = 4
 389   };
 390 
 391   enum EnclosingMethodAttributeOffset {
 392     enclosing_method_class_index_offset = 0,
 393     enclosing_method_method_index_offset = 1,
 394     enclosing_method_attribute_size = 2
 395   };
 396 
 397   // method override check
 398   bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
 399 
 400   // package
 401   bool is_same_class_package(Klass* class2);
 402   bool is_same_class_package(oop classloader2, Symbol* classname2);
 403   static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
 404 
 405   // find an enclosing class (defined where original code was, in jvm.cpp!)
 406   Klass* compute_enclosing_class(bool* inner_is_member, TRAPS) {
 407     instanceKlassHandle self(THREAD, this);
 408     return compute_enclosing_class_impl(self, inner_is_member, THREAD);
 409   }
 410   static Klass* compute_enclosing_class_impl(instanceKlassHandle self,
 411                                                bool* inner_is_member, TRAPS);
 412 
 413   // tell if two classes have the same enclosing class (at package level)
 414   bool is_same_package_member(Klass* class2, TRAPS) {
 415     instanceKlassHandle self(THREAD, this);
 416     return is_same_package_member_impl(self, class2, THREAD);
 417   }
 418   static bool is_same_package_member_impl(instanceKlassHandle self,
 419                                           Klass* class2, TRAPS);
 420 
 421   // initialization state
 422   bool is_loaded() const                   { return _init_state >= loaded; }
 423   bool is_linked() const                   { return _init_state >= linked; }
 424   bool is_initialized() const              { return _init_state == fully_initialized; }
 425   bool is_not_initialized() const          { return _init_state <  being_initialized; }
 426   bool is_being_initialized() const        { return _init_state == being_initialized; }
 427   bool is_in_error_state() const           { return _init_state == initialization_error; }
 428   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 429   ClassState  init_state()                 { return (ClassState)_init_state; }
 430   bool is_rewritten() const                { return (_misc_flags & _misc_rewritten) != 0; }
 431 
 432   // defineClass specified verification
 433   bool should_verify_class() const         {
 434     return (_misc_flags & _misc_should_verify_class) != 0;
 435   }
 436   void set_should_verify_class(bool value) {
 437     if (value) {
 438       _misc_flags |= _misc_should_verify_class;
 439     } else {
 440       _misc_flags &= ~_misc_should_verify_class;
 441     }
 442   }
 443 
 444   // marking
 445   bool is_marked_dependent() const         { return _is_marked_dependent; }
 446   void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
 447 
 448   // initialization (virtuals from Klass)
 449   bool should_be_initialized() const;  // means that initialize should be called
 450   void initialize(TRAPS);
 451   void link_class(TRAPS);
 452   bool link_class_or_fail(TRAPS); // returns false on failure
 453   void unlink_class();
 454   void rewrite_class(TRAPS);
 455   void link_methods(TRAPS);
 456   Method* class_initializer();
 457 
 458   // set the class to initialized if no static initializer is present
 459   void eager_initialize(Thread *thread);
 460 
 461   // reference type
 462   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 463   void set_reference_type(ReferenceType t) {
 464     assert(t == (u1)t, "overflow");
 465     _reference_type = (u1)t;
 466   }
 467 
 468   static ByteSize reference_type_offset() { return in_ByteSize(offset_of(InstanceKlass, _reference_type)); }
 469 
 470   // find local field, returns true if found
 471   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 472   // find field in direct superinterfaces, returns the interface in which the field is defined
 473   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 474   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 475   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 476   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 477   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 478 
 479   // find a non-static or static field given its offset within the class.
 480   bool contains_field_offset(int offset) {
 481     return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
 482   }
 483 
 484   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 485   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 486 
 487   // find a local method (returns NULL if not found)
 488   Method* find_method(Symbol* name, Symbol* signature) const;
 489   static Method* find_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
 490   static Method* find_instance_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
 491 
 492   // find a local method index in default_methods (returns -1 if not found)
 493   static int find_method_index(Array<Method*>* methods, Symbol* name, Symbol* signature);
 494 
 495   // lookup operation (returns NULL if not found)
 496   Method* uncached_lookup_method(Symbol* name, Symbol* signature) const;
 497 
 498   // lookup a method in all the interfaces that this class implements
 499   // (returns NULL if not found)
 500   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, bool skip_default_methods) const;
 501 
 502   // lookup a method in local defaults then in all interfaces
 503   // (returns NULL if not found)
 504   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 505 
 506   // Find method indices by name.  If a method with the specified name is
 507   // found the index to the first method is returned, and 'end' is filled in
 508   // with the index of first non-name-matching method.  If no method is found
 509   // -1 is returned.
 510   int find_method_by_name(Symbol* name, int* end);
 511   static int find_method_by_name(Array<Method*>* methods, Symbol* name, int* end);
 512 
 513   // constant pool
 514   ConstantPool* constants() const        { return _constants; }
 515   void set_constants(ConstantPool* c)    { _constants = c; }
 516 
 517   // protection domain
 518   oop protection_domain() const;
 519 
 520   // signers
 521   objArrayOop signers() const;
 522 
 523   // host class
 524   Klass* host_klass() const              {
 525     Klass** hk = (Klass**)adr_host_klass();
 526     if (hk == NULL) {
 527       return NULL;
 528     } else {
 529       assert(*hk != NULL, "host klass should always be set if the address is not null");
 530       return *hk;
 531     }
 532   }
 533   void set_host_klass(Klass* host)            {
 534     assert(is_anonymous(), "not anonymous");
 535     Klass** addr = (Klass**)adr_host_klass();
 536     assert(addr != NULL, "no reversed space");
 537     if (addr != NULL) {
 538       *addr = host;
 539     }
 540   }
 541   bool is_anonymous() const                {
 542     return (_misc_flags & _misc_is_anonymous) != 0;
 543   }
 544   void set_is_anonymous(bool value)        {
 545     if (value) {
 546       _misc_flags |= _misc_is_anonymous;
 547     } else {
 548       _misc_flags &= ~_misc_is_anonymous;
 549     }
 550   }
 551 
 552   // Oop that keeps the metadata for this class from being unloaded
 553   // in places where the metadata is stored in other places, like nmethods
 554   oop klass_holder() const {
 555     return is_anonymous() ? java_mirror() : class_loader();
 556   }
 557 
 558   bool is_contended() const                {
 559     return (_misc_flags & _misc_is_contended) != 0;
 560   }
 561   void set_is_contended(bool value)        {
 562     if (value) {
 563       _misc_flags |= _misc_is_contended;
 564     } else {
 565       _misc_flags &= ~_misc_is_contended;
 566     }
 567   }
 568 
 569   // source file name
 570   Symbol* source_file_name() const               {
 571     return (_source_file_name_index == 0) ?
 572       (Symbol*)NULL : _constants->symbol_at(_source_file_name_index);
 573   }
 574   u2 source_file_name_index() const              {
 575     return _source_file_name_index;
 576   }
 577   void set_source_file_name_index(u2 sourcefile_index) {
 578     _source_file_name_index = sourcefile_index;
 579   }
 580 
 581   // minor and major version numbers of class file
 582   u2 minor_version() const                 { return _minor_version; }
 583   void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
 584   u2 major_version() const                 { return _major_version; }
 585   void set_major_version(u2 major_version) { _major_version = major_version; }
 586 
 587   // source debug extension
 588   char* source_debug_extension() const     { return _source_debug_extension; }
 589   void set_source_debug_extension(char* array, int length);
 590 
 591   // symbol unloading support (refcount already added)
 592   Symbol* array_name()                     { return _array_name; }
 593   void set_array_name(Symbol* name)        { assert(_array_name == NULL  || name == NULL, "name already created"); _array_name = name; }
 594 
 595   // nonstatic oop-map blocks
 596   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 597     return oop_map_count * OopMapBlock::size_in_words();
 598   }
 599   unsigned int nonstatic_oop_map_count() const {
 600     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 601   }
 602   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 603   void set_nonstatic_oop_map_size(int words) {
 604     _nonstatic_oop_map_size = words;
 605   }
 606 
 607   // RedefineClasses() support for previous versions:
 608   void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
 609          int emcp_method_count);
 610   // If the _previous_versions array is non-NULL, then this klass
 611   // has been redefined at least once even if we aren't currently
 612   // tracking a previous version.
 613   bool has_been_redefined() const { return _previous_versions != NULL; }
 614   bool has_previous_version() const;
 615   void init_previous_versions() {
 616     _previous_versions = NULL;
 617   }
 618   GrowableArray<PreviousVersionNode *>* previous_versions() const {
 619     return _previous_versions;
 620   }
 621 
 622   static void purge_previous_versions(InstanceKlass* ik);
 623 
 624   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 625   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 626     _cached_class_file = data;
 627   }
 628   JvmtiCachedClassFileData * get_cached_class_file() { return _cached_class_file; }
 629   jint get_cached_class_file_len();
 630   unsigned char * get_cached_class_file_bytes();
 631 
 632   // JVMTI: Support for caching of field indices, types, and offsets
 633   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 634     _jvmti_cached_class_field_map = descriptor;
 635   }
 636   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 637     return _jvmti_cached_class_field_map;
 638   }
 639 
 640   bool has_default_methods() const {
 641     return (_misc_flags & _misc_has_default_methods) != 0;
 642   }
 643   void set_has_default_methods(bool b) {
 644     if (b) {
 645       _misc_flags |= _misc_has_default_methods;
 646     } else {
 647       _misc_flags &= ~_misc_has_default_methods;
 648     }
 649   }
 650 
 651   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 652   inline u2 next_method_idnum();
 653   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 654 
 655   // generics support
 656   Symbol* generic_signature() const                   {
 657     return (_generic_signature_index == 0) ?
 658       (Symbol*)NULL : _constants->symbol_at(_generic_signature_index);
 659   }
 660   u2 generic_signature_index() const                  {
 661     return _generic_signature_index;
 662   }
 663   void set_generic_signature_index(u2 sig_index)      {
 664     _generic_signature_index = sig_index;
 665   }
 666 
 667   u2 enclosing_method_data(int offset);
 668   u2 enclosing_method_class_index() {
 669     return enclosing_method_data(enclosing_method_class_index_offset);
 670   }
 671   u2 enclosing_method_method_index() {
 672     return enclosing_method_data(enclosing_method_method_index_offset);
 673   }
 674   void set_enclosing_method_indices(u2 class_index,
 675                                     u2 method_index);
 676 
 677   // jmethodID support
 678   static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
 679                      methodHandle method_h);
 680   static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
 681                      size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
 682                      jmethodID* to_dealloc_id_p,
 683                      jmethodID** to_dealloc_jmeths_p);
 684   static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
 685                 size_t *length_p, jmethodID* id_p);
 686   jmethodID jmethod_id_or_null(Method* method);
 687 
 688   // annotations support
 689   Annotations* annotations() const          { return _annotations; }
 690   void set_annotations(Annotations* anno)   { _annotations = anno; }
 691 
 692   AnnotationArray* class_annotations() const {
 693     return (_annotations != NULL) ? _annotations->class_annotations() : NULL;
 694   }
 695   Array<AnnotationArray*>* fields_annotations() const {
 696     return (_annotations != NULL) ? _annotations->fields_annotations() : NULL;
 697   }
 698   AnnotationArray* class_type_annotations() const {
 699     return (_annotations != NULL) ? _annotations->class_type_annotations() : NULL;
 700   }
 701   Array<AnnotationArray*>* fields_type_annotations() const {
 702     return (_annotations != NULL) ? _annotations->fields_type_annotations() : NULL;
 703   }
 704   // allocation
 705   instanceOop allocate_instance(TRAPS);
 706 
 707   // additional member function to return a handle
 708   instanceHandle allocate_instance_handle(TRAPS)      { return instanceHandle(THREAD, allocate_instance(THREAD)); }
 709 
 710   objArrayOop allocate_objArray(int n, int length, TRAPS);
 711   // Helper function
 712   static instanceOop register_finalizer(instanceOop i, TRAPS);
 713 
 714   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 715   // if not, throw either an Error or an Exception.
 716   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 717 
 718   // initialization
 719   void call_class_initializer(TRAPS);
 720   void set_initialization_state_and_notify(ClassState state, TRAPS);
 721 
 722   // OopMapCache support
 723   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 724   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 725   void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
 726 
 727   // JNI identifier support (for static fields - for jni performance)
 728   JNIid* jni_ids()                               { return _jni_ids; }
 729   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 730   JNIid* jni_id_for(int offset);
 731 
 732   // maintenance of deoptimization dependencies
 733   int mark_dependent_nmethods(DepChange& changes);
 734   void add_dependent_nmethod(nmethod* nm);
 735   void remove_dependent_nmethod(nmethod* nm);
 736 
 737   // On-stack replacement support
 738   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 739   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 740   void add_osr_nmethod(nmethod* n);
 741   void remove_osr_nmethod(nmethod* n);
 742   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 743 
 744   // Breakpoint support (see methods on Method* for details)
 745   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 746   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 747 
 748   // support for stub routines
 749   static ByteSize init_state_offset()  { return in_ByteSize(offset_of(InstanceKlass, _init_state)); }
 750   TRACE_DEFINE_OFFSET;
 751   static ByteSize init_thread_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_thread)); }
 752 
 753   // subclass/subinterface checks
 754   bool implements_interface(Klass* k) const;
 755   bool is_same_or_direct_interface(Klass* k) const;
 756 
 757 #ifdef ASSERT
 758   // check whether this class or one of its superclasses was redefined
 759   bool has_redefined_this_or_super() const;
 760 #endif
 761 
 762   // Access to the implementor of an interface.
 763   Klass* implementor() const
 764   {
 765     Klass** k = adr_implementor();
 766     if (k == NULL) {
 767       return NULL;
 768     } else {
 769       return *k;
 770     }
 771   }
 772 
 773   void set_implementor(Klass* k) {
 774     assert(is_interface(), "not interface");
 775     Klass** addr = adr_implementor();
 776     assert(addr != NULL, "null addr");
 777     if (addr != NULL) {
 778       *addr = k;
 779     }
 780   }
 781 
 782   int  nof_implementors() const       {
 783     Klass* k = implementor();
 784     if (k == NULL) {
 785       return 0;
 786     } else if (k != this) {
 787       return 1;
 788     } else {
 789       return 2;
 790     }
 791   }
 792 
 793   void add_implementor(Klass* k);  // k is a new class that implements this interface
 794   void init_implementor();           // initialize
 795 
 796   // link this class into the implementors list of every interface it implements
 797   void process_interfaces(Thread *thread);
 798 
 799   // virtual operations from Klass
 800   bool is_leaf_class() const               { return _subklass == NULL; }
 801   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
 802   bool compute_is_subtype_of(Klass* k);
 803   bool can_be_primary_super_slow() const;
 804   int oop_size(oop obj)  const             { return size_helper(); }
 805   bool oop_is_instance_slow() const        { return true; }
 806 
 807   // Iterators
 808   void do_local_static_fields(FieldClosure* cl);
 809   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
 810   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
 811 
 812   void methods_do(void f(Method* method));
 813   void array_klasses_do(void f(Klass* k));
 814   void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
 815   bool super_types_do(SuperTypeClosure* blk);
 816 
 817   // Casting from Klass*
 818   static InstanceKlass* cast(Klass* k) {
 819     assert(k == NULL || k->is_klass(), "must be");
 820     assert(k == NULL || k->oop_is_instance(), "cast to InstanceKlass");
 821     return (InstanceKlass*) k;
 822   }
 823 
 824   InstanceKlass* java_super() const {
 825     return (super() == NULL) ? NULL : cast(super());
 826   }
 827 
 828   // Sizing (in words)
 829   static int header_size()            { return align_object_offset(sizeof(InstanceKlass)/HeapWordSize); }
 830 
 831   static int size(int vtable_length, int itable_length,
 832                   int nonstatic_oop_map_size,
 833                   bool is_interface, bool is_anonymous) {
 834     return align_object_size(header_size() +
 835            align_object_offset(vtable_length) +
 836            align_object_offset(itable_length) +
 837            ((is_interface || is_anonymous) ?
 838              align_object_offset(nonstatic_oop_map_size) :
 839              nonstatic_oop_map_size) +
 840            (is_interface ? (int)sizeof(Klass*)/HeapWordSize : 0) +
 841            (is_anonymous ? (int)sizeof(Klass*)/HeapWordSize : 0));
 842   }
 843   int size() const                    { return size(vtable_length(),
 844                                                itable_length(),
 845                                                nonstatic_oop_map_size(),
 846                                                is_interface(),
 847                                                is_anonymous());
 848   }
 849 #if INCLUDE_SERVICES
 850   virtual void collect_statistics(KlassSizeStats *sz) const;
 851 #endif
 852 
 853   static int vtable_start_offset()    { return header_size(); }
 854   static int vtable_length_offset()   { return offset_of(InstanceKlass, _vtable_len) / HeapWordSize; }
 855 
 856   intptr_t* start_of_vtable() const        { return ((intptr_t*)this) + vtable_start_offset(); }
 857   intptr_t* start_of_itable() const        { return start_of_vtable() + align_object_offset(vtable_length()); }
 858   int  itable_offset_in_words() const { return start_of_itable() - (intptr_t*)this; }
 859 
 860   intptr_t* end_of_itable() const          { return start_of_itable() + itable_length(); }
 861 
 862   address static_field_addr(int offset);
 863 
 864   OopMapBlock* start_of_nonstatic_oop_maps() const {
 865     return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
 866   }
 867 
 868   Klass** end_of_nonstatic_oop_maps() const {
 869     return (Klass**)(start_of_nonstatic_oop_maps() +
 870                      nonstatic_oop_map_count());
 871   }
 872 
 873   Klass** adr_implementor() const {
 874     if (is_interface()) {
 875       return (Klass**)end_of_nonstatic_oop_maps();
 876     } else {
 877       return NULL;
 878     }
 879   };
 880 
 881   Klass** adr_host_klass() const {
 882     if (is_anonymous()) {
 883       Klass** adr_impl = adr_implementor();
 884       if (adr_impl != NULL) {
 885         return adr_impl + 1;
 886       } else {
 887         return end_of_nonstatic_oop_maps();
 888       }
 889     } else {
 890       return NULL;
 891     }
 892   }
 893 
 894   // Use this to return the size of an instance in heap words:
 895   int size_helper() const {
 896     return layout_helper_to_size_helper(layout_helper());
 897   }
 898 
 899   // This bit is initialized in classFileParser.cpp.
 900   // It is false under any of the following conditions:
 901   //  - the class is abstract (including any interface)
 902   //  - the class has a finalizer (if !RegisterFinalizersAtInit)
 903   //  - the class size is larger than FastAllocateSizeLimit
 904   //  - the class is java/lang/Class, which cannot be allocated directly
 905   bool can_be_fastpath_allocated() const {
 906     return !layout_helper_needs_slow_path(layout_helper());
 907   }
 908 
 909   // Java vtable/itable
 910   klassVtable* vtable() const;        // return new klassVtable wrapper
 911   inline Method* method_at_vtable(int index);
 912   klassItable* itable() const;        // return new klassItable wrapper
 913   Method* method_at_itable(Klass* holder, int index, TRAPS);
 914 
 915 #if INCLUDE_JVMTI
 916   void adjust_default_methods(Method** old_methods, Method** new_methods,
 917                               int methods_length, bool* trace_name_printed);
 918 #endif // INCLUDE_JVMTI
 919 
 920   // Garbage collection
 921   void oop_follow_contents(oop obj);
 922   int  oop_adjust_pointers(oop obj);
 923 
 924   void clean_implementors_list(BoolObjectClosure* is_alive);
 925   void clean_method_data(BoolObjectClosure* is_alive);
 926 
 927   // Explicit metaspace deallocation of fields
 928   // For RedefineClasses and class file parsing errors, we need to deallocate
 929   // instanceKlasses and the metadata they point to.
 930   void deallocate_contents(ClassLoaderData* loader_data);
 931   static void deallocate_methods(ClassLoaderData* loader_data,
 932                                  Array<Method*>* methods);
 933   void static deallocate_interfaces(ClassLoaderData* loader_data,
 934                                     Klass* super_klass,
 935                                     Array<Klass*>* local_interfaces,
 936                                     Array<Klass*>* transitive_interfaces);
 937 
 938   // The constant pool is on stack if any of the methods are executing or
 939   // referenced by handles.
 940   bool on_stack() const { return _constants->on_stack(); }
 941 
 942   // callbacks for actions during class unloading
 943   static void notify_unload_class(InstanceKlass* ik);
 944   static void release_C_heap_structures(InstanceKlass* ik);
 945 
 946   // Parallel Scavenge and Parallel Old
 947   PARALLEL_GC_DECLS
 948 
 949   // Naming
 950   const char* signature_name() const;
 951 
 952   // Iterators
 953   int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) {
 954     return oop_oop_iterate_v(obj, blk);
 955   }
 956 
 957   int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) {
 958     return oop_oop_iterate_v_m(obj, blk, mr);
 959   }
 960 
 961 #define InstanceKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)      \
 962   int  oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk);           \
 963   int  oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk,        \
 964                                       MemRegion mr);
 965 
 966   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DECL)
 967   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DECL)
 968 
 969 #if INCLUDE_ALL_GCS
 970 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
 971   int  oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
 972 
 973   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
 974   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
 975 #endif // INCLUDE_ALL_GCS
 976 
 977   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
 978 
 979 private:
 980   // initialization state
 981 #ifdef ASSERT
 982   void set_init_state(ClassState state);
 983 #else
 984   void set_init_state(ClassState state) { _init_state = (u1)state; }
 985 #endif
 986   void set_rewritten()                  { _misc_flags |= _misc_rewritten; }
 987   void set_init_thread(Thread *thread)  { _init_thread = thread; }
 988 
 989   // The RedefineClasses() API can cause new method idnums to be needed
 990   // which will cause the caches to grow. Safety requires different
 991   // cache management logic if the caches can grow instead of just
 992   // going from NULL to non-NULL.
 993   bool idnum_can_increment() const      { return has_been_redefined(); }
 994   jmethodID* methods_jmethod_ids_acquire() const
 995          { return (jmethodID*)OrderAccess::load_ptr_acquire(&_methods_jmethod_ids); }
 996   void release_set_methods_jmethod_ids(jmethodID* jmeths)
 997          { OrderAccess::release_store_ptr(&_methods_jmethod_ids, jmeths); }
 998 
 999   // Lock during initialization
1000 public:
1001   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
1002   // Must be one per class and it has to be a VM internal object so java code
1003   // cannot lock it (like the mirror).
1004   // It has to be an object not a Mutex because it's held through java calls.
1005   oop init_lock() const;
1006 private:
1007   void fence_and_clear_init_lock();
1008 
1009   // Static methods that are used to implement member methods where an exposed this pointer
1010   // is needed due to possible GCs
1011   static bool link_class_impl                           (instanceKlassHandle this_k, bool throw_verifyerror, TRAPS);
1012   static bool verify_code                               (instanceKlassHandle this_k, bool throw_verifyerror, TRAPS);
1013   static void initialize_impl                           (instanceKlassHandle this_k, TRAPS);
1014   static void eager_initialize_impl                     (instanceKlassHandle this_k);
1015   static void set_initialization_state_and_notify_impl  (instanceKlassHandle this_k, ClassState state, TRAPS);
1016   static void call_class_initializer_impl               (instanceKlassHandle this_k, TRAPS);
1017   static Klass* array_klass_impl                        (instanceKlassHandle this_k, bool or_null, int n, TRAPS);
1018   static void do_local_static_fields_impl               (instanceKlassHandle this_k, void f(fieldDescriptor* fd, Handle, TRAPS), Handle, TRAPS);
1019   /* jni_id_for_impl for jfieldID only */
1020   static JNIid* jni_id_for_impl                         (instanceKlassHandle this_k, int offset);
1021 
1022   // Returns the array class for the n'th dimension
1023   Klass* array_klass_impl(bool or_null, int n, TRAPS);
1024 
1025   // Returns the array class with this class as element type
1026   Klass* array_klass_impl(bool or_null, TRAPS);
1027 
1028   // Free CHeap allocated fields.
1029   void release_C_heap_structures();
1030 public:
1031   // CDS support - remove and restore oops from metadata. Oops are not shared.
1032   virtual void remove_unshareable_info();
1033   virtual void restore_unshareable_info(TRAPS);
1034 
1035   // jvm support
1036   jint compute_modifier_flags(TRAPS) const;
1037 
1038   // JSR-292 support
1039   MemberNameTable* member_names() { return _member_names; }
1040   void set_member_names(MemberNameTable* member_names) { _member_names = member_names; }
1041   void add_member_name(int index, Handle member_name);
1042   oop  get_member_name(int index);
1043 
1044 public:
1045   // JVMTI support
1046   jint jvmti_class_status() const;
1047 
1048  public:
1049   // Printing
1050 #ifndef PRODUCT
1051   void print_on(outputStream* st) const;
1052 #endif
1053   void print_value_on(outputStream* st) const;
1054 
1055   void oop_print_value_on(oop obj, outputStream* st);
1056 
1057 #ifndef PRODUCT
1058   void oop_print_on      (oop obj, outputStream* st);
1059 
1060   void print_dependent_nmethods(bool verbose = false);
1061   bool is_dependent_nmethod(nmethod* nm);
1062 #endif
1063 
1064   const char* internal_name() const;
1065 
1066   // Verification
1067   void verify_on(outputStream* st);
1068 
1069   void oop_verify_on(oop obj, outputStream* st);
1070 };
1071 
1072 inline Method* InstanceKlass::method_at_vtable(int index)  {
1073 #ifndef PRODUCT
1074   assert(index >= 0, "valid vtable index");
1075   if (DebugVtables) {
1076     verify_vtable_index(index);
1077   }
1078 #endif
1079   vtableEntry* ve = (vtableEntry*)start_of_vtable();
1080   return ve[index].method();
1081 }
1082 
1083 // for adding methods
1084 // UNSET_IDNUM return means no more ids available
1085 inline u2 InstanceKlass::next_method_idnum() {
1086   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1087     return ConstMethod::UNSET_IDNUM; // no more ids available
1088   } else {
1089     return _idnum_allocated_count++;
1090   }
1091 }
1092 
1093 
1094 /* JNIid class for jfieldIDs only */
1095 class JNIid: public CHeapObj<mtClass> {
1096   friend class VMStructs;
1097  private:
1098   Klass*             _holder;
1099   JNIid*             _next;
1100   int                _offset;
1101 #ifdef ASSERT
1102   bool               _is_static_field_id;
1103 #endif
1104 
1105  public:
1106   // Accessors
1107   Klass* holder() const           { return _holder; }
1108   int offset() const              { return _offset; }
1109   JNIid* next()                   { return _next; }
1110   // Constructor
1111   JNIid(Klass* holder, int offset, JNIid* next);
1112   // Identifier lookup
1113   JNIid* find(int offset);
1114 
1115   bool find_local_field(fieldDescriptor* fd) {
1116     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1117   }
1118 
1119   static void deallocate(JNIid* id);
1120   // Debugging
1121 #ifdef ASSERT
1122   bool is_static_field_id() const { return _is_static_field_id; }
1123   void set_is_static_field_id()   { _is_static_field_id = true; }
1124 #endif
1125   void verify(Klass* holder);
1126 };
1127 
1128 
1129 // If breakpoints are more numerous than just JVMTI breakpoints,
1130 // consider compressing this data structure.
1131 // It is currently a simple linked list defined in method.hpp.
1132 
1133 class BreakpointInfo;
1134 
1135 
1136 // A collection point for interesting information about the previous
1137 // version(s) of an InstanceKlass.  A GrowableArray of PreviousVersionNodes
1138 // is attached to the InstanceKlass as needed. See PreviousVersionWalker below.
1139 class PreviousVersionNode : public CHeapObj<mtClass> {
1140  private:
1141   ConstantPool*    _prev_constant_pool;
1142 
1143   // If the previous version of the InstanceKlass doesn't have any
1144   // EMCP methods, then _prev_EMCP_methods will be NULL. If all the
1145   // EMCP methods have been collected, then _prev_EMCP_methods can
1146   // have a length of zero.
1147   GrowableArray<Method*>* _prev_EMCP_methods;
1148 
1149 public:
1150   PreviousVersionNode(ConstantPool* prev_constant_pool,
1151                       GrowableArray<Method*>* prev_EMCP_methods);
1152   ~PreviousVersionNode();
1153   ConstantPool* prev_constant_pool() const {
1154     return _prev_constant_pool;
1155   }
1156   GrowableArray<Method*>* prev_EMCP_methods() const {
1157     return _prev_EMCP_methods;
1158   }
1159 };
1160 
1161 
1162 // Helper object for walking previous versions.
1163 class PreviousVersionWalker : public StackObj {
1164  private:
1165   Thread*                               _thread;
1166   GrowableArray<PreviousVersionNode *>* _previous_versions;
1167   int                                   _current_index;
1168 
1169   // A pointer to the current node object so we can handle the deletes.
1170   PreviousVersionNode*                  _current_p;
1171 
1172   // The constant pool handle keeps all the methods in this class from being
1173   // deallocated from the metaspace during class unloading.
1174   constantPoolHandle                    _current_constant_pool_handle;
1175 
1176  public:
1177   PreviousVersionWalker(Thread* thread, InstanceKlass *ik);
1178 
1179   // Return the interesting information for the next previous version
1180   // of the klass. Returns NULL if there are no more previous versions.
1181   PreviousVersionNode* next_previous_version();
1182 };
1183 
1184 
1185 //
1186 // nmethodBucket is used to record dependent nmethods for
1187 // deoptimization.  nmethod dependencies are actually <klass, method>
1188 // pairs but we really only care about the klass part for purposes of
1189 // finding nmethods which might need to be deoptimized.  Instead of
1190 // recording the method, a count of how many times a particular nmethod
1191 // was recorded is kept.  This ensures that any recording errors are
1192 // noticed since an nmethod should be removed as many times are it's
1193 // added.
1194 //
1195 class nmethodBucket: public CHeapObj<mtClass> {
1196   friend class VMStructs;
1197  private:
1198   nmethod*       _nmethod;
1199   int            _count;
1200   nmethodBucket* _next;
1201 
1202  public:
1203   nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
1204     _nmethod = nmethod;
1205     _next = next;
1206     _count = 1;
1207   }
1208   int count()                             { return _count; }
1209   int increment()                         { _count += 1; return _count; }
1210   int decrement()                         { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
1211   nmethodBucket* next()                   { return _next; }
1212   void set_next(nmethodBucket* b)         { _next = b; }
1213   nmethod* get_nmethod()                  { return _nmethod; }
1214 };
1215 
1216 // An iterator that's used to access the inner classes indices in the
1217 // InstanceKlass::_inner_classes array.
1218 class InnerClassesIterator : public StackObj {
1219  private:
1220   Array<jushort>* _inner_classes;
1221   int _length;
1222   int _idx;
1223  public:
1224 
1225   InnerClassesIterator(instanceKlassHandle k) {
1226     _inner_classes = k->inner_classes();
1227     if (k->inner_classes() != NULL) {
1228       _length = _inner_classes->length();
1229       // The inner class array's length should be the multiple of
1230       // inner_class_next_offset if it only contains the InnerClasses
1231       // attribute data, or it should be
1232       // n*inner_class_next_offset+enclosing_method_attribute_size
1233       // if it also contains the EnclosingMethod data.
1234       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1235               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1236              "just checking");
1237       // Remove the enclosing_method portion if exists.
1238       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1239         _length -= InstanceKlass::enclosing_method_attribute_size;
1240       }
1241     } else {
1242       _length = 0;
1243     }
1244     _idx = 0;
1245   }
1246 
1247   int length() const {
1248     return _length;
1249   }
1250 
1251   void next() {
1252     _idx += InstanceKlass::inner_class_next_offset;
1253   }
1254 
1255   bool done() const {
1256     return (_idx >= _length);
1257   }
1258 
1259   u2 inner_class_info_index() const {
1260     return _inner_classes->at(
1261                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1262   }
1263 
1264   void set_inner_class_info_index(u2 index) {
1265     _inner_classes->at_put(
1266                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1267   }
1268 
1269   u2 outer_class_info_index() const {
1270     return _inner_classes->at(
1271                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1272   }
1273 
1274   void set_outer_class_info_index(u2 index) {
1275     _inner_classes->at_put(
1276                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1277   }
1278 
1279   u2 inner_name_index() const {
1280     return _inner_classes->at(
1281                _idx + InstanceKlass::inner_class_inner_name_offset);
1282   }
1283 
1284   void set_inner_name_index(u2 index) {
1285     _inner_classes->at_put(
1286                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1287   }
1288 
1289   u2 inner_access_flags() const {
1290     return _inner_classes->at(
1291                _idx + InstanceKlass::inner_class_access_flags_offset);
1292   }
1293 };
1294 
1295 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP