1 /*
   2  * Copyright (c) 1997, 2013, 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 "oops/annotations.hpp"
  30 #include "oops/constMethod.hpp"
  31 #include "oops/fieldInfo.hpp"
  32 #include "oops/instanceOop.hpp"
  33 #include "oops/klassVtable.hpp"
  34 #include "runtime/atomic.hpp"
  35 #include "runtime/handles.hpp"
  36 #include "runtime/os.hpp"
  37 #include "utilities/accessFlags.hpp"
  38 #include "utilities/bitMap.inline.hpp"
  39 #include "utilities/macros.hpp"
  40 
  41 // An InstanceKlass is the VM level representation of a Java class.
  42 // It contains all information needed for at class at execution runtime.
  43 
  44 //  InstanceKlass layout:
  45 //    [C++ vtbl pointer           ] Klass
  46 //    [subtype cache              ] Klass
  47 //    [instance size              ] Klass
  48 //    [java mirror                ] Klass
  49 //    [super                      ] Klass
  50 //    [access_flags               ] Klass
  51 //    [name                       ] Klass
  52 //    [first subklass             ] Klass
  53 //    [next sibling               ] Klass
  54 //    [array klasses              ]
  55 //    [methods                    ]
  56 //    [local interfaces           ]
  57 //    [transitive interfaces      ]
  58 //    [fields                     ]
  59 //    [constants                  ]
  60 //    [class loader               ]
  61 //    [protection domain          ]
  62 //    [signers                    ]
  63 //    [source file name           ]
  64 //    [inner classes              ]
  65 //    [static field size          ]
  66 //    [nonstatic field size       ]
  67 //    [static oop fields size     ]
  68 //    [nonstatic oop maps size    ]
  69 //    [has finalize method        ]
  70 //    [deoptimization mark bit    ]
  71 //    [initialization state       ]
  72 //    [initializing thread        ]
  73 //    [Java vtable length         ]
  74 //    [oop map cache (stack maps) ]
  75 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  76 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  77 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  78 //      indicating where oops are located in instances of this klass.
  79 //    [EMBEDDED implementor of the interface] only exist for interface
  80 //    [EMBEDDED host klass        ] only exist for an anonymous class (JSR 292 enabled)
  81 
  82 
  83 // forward declaration for class -- see below for definition
  84 class SuperTypeClosure;
  85 class JNIid;
  86 class jniIdMapBase;
  87 class BreakpointInfo;
  88 class fieldDescriptor;
  89 class DepChange;
  90 class nmethodBucket;
  91 class PreviousVersionNode;
  92 class JvmtiCachedClassFieldMap;
  93 
  94 // This is used in iterators below.
  95 class FieldClosure: public StackObj {
  96 public:
  97   virtual void do_field(fieldDescriptor* fd) = 0;
  98 };
  99 
 100 #ifndef PRODUCT
 101 // Print fields.
 102 // If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.
 103 class FieldPrinter: public FieldClosure {
 104    oop _obj;
 105    outputStream* _st;
 106  public:
 107    FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}
 108    void do_field(fieldDescriptor* fd);
 109 };
 110 #endif  // !PRODUCT
 111 
 112 // ValueObjs embedded in klass. Describes where oops are located in instances of
 113 // this klass.
 114 class OopMapBlock VALUE_OBJ_CLASS_SPEC {
 115  public:
 116   // Byte offset of the first oop mapped by this block.
 117   int offset() const          { return _offset; }
 118   void set_offset(int offset) { _offset = offset; }
 119 
 120   // Number of oops in this block.
 121   uint count() const         { return _count; }
 122   void set_count(uint count) { _count = count; }
 123 
 124   // sizeof(OopMapBlock) in HeapWords.
 125   static const int size_in_words() {
 126     return align_size_up(int(sizeof(OopMapBlock)), HeapWordSize) >>
 127       LogHeapWordSize;
 128   }
 129 
 130  private:
 131   int  _offset;
 132   uint _count;
 133 };
 134 
 135 class InstanceKlass: public Klass {
 136   friend class VMStructs;
 137   friend class ClassFileParser;
 138   friend class CompileReplay;
 139 
 140  protected:
 141   // Constructor
 142   InstanceKlass(int vtable_len,
 143                 int itable_len,
 144                 int static_field_size,
 145                 int nonstatic_oop_map_size,
 146                 ReferenceType rt,
 147                 AccessFlags access_flags,
 148                 bool is_anonymous);
 149  public:
 150   static InstanceKlass* allocate_instance_klass(
 151                                           ClassLoaderData* loader_data,
 152                                           int vtable_len,
 153                                           int itable_len,
 154                                           int static_field_size,
 155                                           int nonstatic_oop_map_size,
 156                                           ReferenceType rt,
 157                                           AccessFlags access_flags,
 158                                           Symbol* name,
 159                                           Klass* super_klass,
 160                                           bool is_anonymous,
 161                                           TRAPS);
 162 
 163   InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
 164 
 165   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 166   // of the class loading & initialization procedure, and the use of the states.
 167   enum ClassState {
 168     allocated,                          // allocated (but not yet linked)
 169     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 170     linked,                             // successfully linked/verified (but not initialized yet)
 171     being_initialized,                  // currently running class initializer
 172     fully_initialized,                  // initialized (successfull final state)
 173     initialization_error                // error happened during initialization
 174   };
 175 
 176   static int number_of_instance_classes() { return _total_instanceKlass_count; }
 177 
 178  private:
 179   static volatile int _total_instanceKlass_count;
 180 
 181  protected:
 182   // Protection domain.
 183   oop             _protection_domain;
 184   // Class signers.
 185   objArrayOop     _signers;
 186   // Initialization lock.  Must be one per class and it has to be a VM internal
 187   // object so java code cannot lock it (like the mirror)
 188   // It has to be an object not a Mutex because it's held through java calls.
 189   volatile oop    _init_lock;
 190 
 191   // Annotations for this class
 192   Annotations*    _annotations;
 193   // Array classes holding elements of this class.
 194   Klass*          _array_klasses;
 195   // Constant pool for this class.
 196   ConstantPool* _constants;
 197   // The InnerClasses attribute and EnclosingMethod attribute. The
 198   // _inner_classes is an array of shorts. If the class has InnerClasses
 199   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 200   // [inner_class_info_index, outer_class_info_index,
 201   // inner_name_index, inner_class_access_flags] for the InnerClasses
 202   // attribute. If the EnclosingMethod attribute exists, it occupies the
 203   // last two shorts [class_index, method_index] of the array. If only
 204   // the InnerClasses attribute exists, the _inner_classes array length is
 205   // number_of_inner_classes * 4. If the class has both InnerClasses
 206   // and EnclosingMethod attributes the _inner_classes array length is
 207   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 208   Array<jushort>* _inner_classes;
 209 
 210   // Name of source file containing this klass, NULL if not specified.
 211   Symbol*         _source_file_name;
 212   // the source debug extension for this klass, NULL if not specified.
 213   // Specified as UTF-8 string without terminating zero byte in the classfile,
 214   // it is stored in the instanceklass as a NULL-terminated UTF-8 string
 215   char*           _source_debug_extension;
 216   // Generic signature, or null if none.
 217   Symbol*         _generic_signature;
 218   // Array name derived from this class which needs unreferencing
 219   // if this class is unloaded.
 220   Symbol*         _array_name;
 221 
 222   // Number of heapOopSize words used by non-static fields in this klass
 223   // (including inherited fields but after header_size()).
 224   int             _nonstatic_field_size;
 225   int             _static_field_size;    // number words used by static fields (oop and non-oop) in this klass
 226   u2              _static_oop_field_count;// number of static oop fields in this klass
 227   u2              _java_fields_count;    // The number of declared Java fields
 228   int             _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
 229 
 230   // _is_marked_dependent can be set concurrently, thus cannot be part of the
 231   // _misc_flags.
 232   bool            _is_marked_dependent;  // used for marking during flushing and deoptimization
 233 
 234   enum {
 235     _misc_rewritten            = 1 << 0, // methods rewritten.
 236     _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
 237     _misc_should_verify_class  = 1 << 2, // allow caching of preverification
 238     _misc_is_anonymous         = 1 << 3, // has embedded _inner_classes field
 239     _misc_is_contended         = 1 << 4, // marked with contended annotation
 240     _misc_has_default_methods  = 1 << 5  // class/superclass/implemented interfaces has default methods
 241   };
 242   u2              _misc_flags;
 243   u2              _minor_version;        // minor version number of class file
 244   u2              _major_version;        // major version number of class file
 245   Thread*         _init_thread;          // Pointer to current thread doing initialization (to handle recusive initialization)
 246   int             _vtable_len;           // length of Java vtable (in words)
 247   int             _itable_len;           // length of Java itable (in words)
 248   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 249   JNIid*          _jni_ids;              // First JNI identifier for static fields in this class
 250   jmethodID*      _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or NULL if none
 251   int*            _methods_cached_itable_indices;  // itable_index cache for JNI invoke corresponding to methods idnum, or NULL
 252   nmethodBucket*  _dependencies;         // list of dependent nmethods
 253   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 254   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 255   // Array of interesting part(s) of the previous version(s) of this
 256   // InstanceKlass. See PreviousVersionWalker below.
 257   GrowableArray<PreviousVersionNode *>* _previous_versions;
 258   // JVMTI fields can be moved to their own structure - see 6315920
 259   unsigned char * _cached_class_file_bytes;       // JVMTI: cached class file, before retransformable agent modified it in CFLH
 260   jint            _cached_class_file_len;         // JVMTI: length of above
 261 
 262   volatile u2     _idnum_allocated_count;         // JNI/JVMTI: increments with the addition of methods, old ids don't change
 263 
 264   // Class states are defined as ClassState (see above).
 265   // Place the _init_state here to utilize the unused 2-byte after
 266   // _idnum_allocated_count.
 267   u1              _init_state;                    // state of class
 268   u1              _reference_type;                // reference type
 269 
 270   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 271 
 272   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 273 
 274   // Method array.
 275   Array<Method*>* _methods;
 276   // Interface (Klass*s) this class declares locally to implement.
 277   Array<Klass*>* _local_interfaces;
 278   // Interface (Klass*s) this class implements transitively.
 279   Array<Klass*>* _transitive_interfaces;
 280   // Int array containing the original order of method in the class file (for JVMTI).
 281   Array<int>*     _method_ordering;
 282   // Instance and static variable information, starts with 6-tuples of shorts
 283   // [access, name index, sig index, initval index, low_offset, high_offset]
 284   // for all fields, followed by the generic signature data at the end of
 285   // the array. Only fields with generic signature attributes have the generic
 286   // signature data set in the array. The fields array looks like following:
 287   //
 288   // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
 289   // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
 290   //      ...
 291   // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
 292   //     [generic signature index]
 293   //     [generic signature index]
 294   //     ...
 295   Array<u2>*      _fields;
 296 
 297   // embedded Java vtable follows here
 298   // embedded Java itables follows here
 299   // embedded static fields follows here
 300   // embedded nonstatic oop-map blocks follows here
 301   // embedded implementor of this interface follows here
 302   //   The embedded implementor only exists if the current klass is an
 303   //   iterface. The possible values of the implementor fall into following
 304   //   three cases:
 305   //     NULL: no implementor.
 306   //     A Klass* that's not itself: one implementor.
 307   //     Itsef: more than one implementors.
 308   // embedded host klass follows here
 309   //   The embedded host klass only exists in an anonymous class for
 310   //   dynamic language support (JSR 292 enabled). The host class grants
 311   //   its access privileges to this class also. The host class is either
 312   //   named, or a previously loaded anonymous class. A non-anonymous class
 313   //   or an anonymous class loaded through normal classloading does not
 314   //   have this embedded field.
 315   //
 316 
 317   friend class SystemDictionary;
 318 
 319  public:
 320   bool has_nonstatic_fields() const        {
 321     return (_misc_flags & _misc_has_nonstatic_fields) != 0;
 322   }
 323   void set_has_nonstatic_fields(bool b)    {
 324     if (b) {
 325       _misc_flags |= _misc_has_nonstatic_fields;
 326     } else {
 327       _misc_flags &= ~_misc_has_nonstatic_fields;
 328     }
 329   }
 330 
 331   // field sizes
 332   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 333   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 334 
 335   int static_field_size() const            { return _static_field_size; }
 336   void set_static_field_size(int size)     { _static_field_size = size; }
 337 
 338   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 339   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 340 
 341   // Java vtable
 342   int  vtable_length() const               { return _vtable_len; }
 343   void set_vtable_length(int len)          { _vtable_len = len; }
 344 
 345   // Java itable
 346   int  itable_length() const               { return _itable_len; }
 347   void set_itable_length(int len)          { _itable_len = len; }
 348 
 349   // array klasses
 350   Klass* array_klasses() const             { return _array_klasses; }
 351   void set_array_klasses(Klass* k)         { _array_klasses = k; }
 352 
 353   // methods
 354   Array<Method*>* methods() const          { return _methods; }
 355   void set_methods(Array<Method*>* a)      { _methods = a; }
 356   Method* method_with_idnum(int idnum);
 357 
 358   // method ordering
 359   Array<int>* method_ordering() const     { return _method_ordering; }
 360   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 361   void copy_method_ordering(intArray* m, TRAPS);
 362 
 363   // interfaces
 364   Array<Klass*>* local_interfaces() const          { return _local_interfaces; }
 365   void set_local_interfaces(Array<Klass*>* a)      {
 366     guarantee(_local_interfaces == NULL || a == NULL, "Just checking");
 367     _local_interfaces = a; }
 368 
 369   Array<Klass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 370   void set_transitive_interfaces(Array<Klass*>* a) {
 371     guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");
 372     _transitive_interfaces = a;
 373   }
 374 
 375  private:
 376   friend class fieldDescriptor;
 377   FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
 378 
 379  public:
 380   int     field_offset      (int index) const { return field(index)->offset(); }
 381   int     field_access_flags(int index) const { return field(index)->access_flags(); }
 382   Symbol* field_name        (int index) const { return field(index)->name(constants()); }
 383   Symbol* field_signature   (int index) const { return field(index)->signature(constants()); }
 384 
 385   // Number of Java declared fields
 386   int java_fields_count() const           { return (int)_java_fields_count; }
 387 
 388   Array<u2>* fields() const            { return _fields; }
 389   void set_fields(Array<u2>* f, u2 java_fields_count) {
 390     guarantee(_fields == NULL || f == NULL, "Just checking");
 391     _fields = f;
 392     _java_fields_count = java_fields_count;
 393   }
 394 
 395   // inner classes
 396   Array<u2>* inner_classes() const       { return _inner_classes; }
 397   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 398 
 399   enum InnerClassAttributeOffset {
 400     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 401     inner_class_inner_class_info_offset = 0,
 402     inner_class_outer_class_info_offset = 1,
 403     inner_class_inner_name_offset = 2,
 404     inner_class_access_flags_offset = 3,
 405     inner_class_next_offset = 4
 406   };
 407 
 408   enum EnclosingMethodAttributeOffset {
 409     enclosing_method_class_index_offset = 0,
 410     enclosing_method_method_index_offset = 1,
 411     enclosing_method_attribute_size = 2
 412   };
 413 
 414   // method override check
 415   bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
 416 
 417   // package
 418   bool is_same_class_package(Klass* class2);
 419   bool is_same_class_package(oop classloader2, Symbol* classname2);
 420   static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
 421 
 422   // find an enclosing class (defined where original code was, in jvm.cpp!)
 423   Klass* compute_enclosing_class(bool* inner_is_member, TRAPS) {
 424     instanceKlassHandle self(THREAD, this);
 425     return compute_enclosing_class_impl(self, inner_is_member, THREAD);
 426   }
 427   static Klass* compute_enclosing_class_impl(instanceKlassHandle self,
 428                                                bool* inner_is_member, TRAPS);
 429 
 430   // tell if two classes have the same enclosing class (at package level)
 431   bool is_same_package_member(Klass* class2, TRAPS) {
 432     instanceKlassHandle self(THREAD, this);
 433     return is_same_package_member_impl(self, class2, THREAD);
 434   }
 435   static bool is_same_package_member_impl(instanceKlassHandle self,
 436                                           Klass* class2, TRAPS);
 437 
 438   // initialization state
 439   bool is_loaded() const                   { return _init_state >= loaded; }
 440   bool is_linked() const                   { return _init_state >= linked; }
 441   bool is_initialized() const              { return _init_state == fully_initialized; }
 442   bool is_not_initialized() const          { return _init_state <  being_initialized; }
 443   bool is_being_initialized() const        { return _init_state == being_initialized; }
 444   bool is_in_error_state() const           { return _init_state == initialization_error; }
 445   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 446   ClassState  init_state()                 { return (ClassState)_init_state; }
 447   bool is_rewritten() const                { return (_misc_flags & _misc_rewritten) != 0; }
 448 
 449   // defineClass specified verification
 450   bool should_verify_class() const         {
 451     return (_misc_flags & _misc_should_verify_class) != 0;
 452   }
 453   void set_should_verify_class(bool value) {
 454     if (value) {
 455       _misc_flags |= _misc_should_verify_class;
 456     } else {
 457       _misc_flags &= ~_misc_should_verify_class;
 458     }
 459   }
 460 
 461   // marking
 462   bool is_marked_dependent() const         { return _is_marked_dependent; }
 463   void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
 464 
 465   // initialization (virtuals from Klass)
 466   bool should_be_initialized() const;  // means that initialize should be called
 467   void initialize(TRAPS);
 468   void link_class(TRAPS);
 469   bool link_class_or_fail(TRAPS); // returns false on failure
 470   void unlink_class();
 471   void rewrite_class(TRAPS);
 472   void link_methods(TRAPS);
 473   Method* class_initializer();
 474 
 475   // set the class to initialized if no static initializer is present
 476   void eager_initialize(Thread *thread);
 477 
 478   // reference type
 479   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 480   void set_reference_type(ReferenceType t) {
 481     assert(t == (u1)t, "overflow");
 482     _reference_type = (u1)t;
 483   }
 484 
 485   static ByteSize reference_type_offset() { return in_ByteSize(offset_of(InstanceKlass, _reference_type)); }
 486 
 487   // find local field, returns true if found
 488   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 489   // find field in direct superinterfaces, returns the interface in which the field is defined
 490   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 491   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 492   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 493   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 494   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 495 
 496   // find a non-static or static field given its offset within the class.
 497   bool contains_field_offset(int offset) {
 498     return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
 499   }
 500 
 501   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 502   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 503 
 504   // find a local method (returns NULL if not found)
 505   Method* find_method(Symbol* name, Symbol* signature) const;
 506   static Method* find_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
 507 
 508   // lookup operation (returns NULL if not found)
 509   Method* uncached_lookup_method(Symbol* name, Symbol* signature) const;
 510 
 511   // lookup a method in all the interfaces that this class implements
 512   // (returns NULL if not found)
 513   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature) const;
 514 
 515   // Find method indices by name.  If a method with the specified name is
 516   // found the index to the first method is returned, and 'end' is filled in
 517   // with the index of first non-name-matching method.  If no method is found
 518   // -1 is returned.
 519   int find_method_by_name(Symbol* name, int* end);
 520   static int find_method_by_name(Array<Method*>* methods, Symbol* name, int* end);
 521 
 522   // constant pool
 523   ConstantPool* constants() const        { return _constants; }
 524   void set_constants(ConstantPool* c)    { _constants = c; }
 525 
 526   // protection domain
 527   oop protection_domain()                  { return _protection_domain; }
 528   void set_protection_domain(oop pd)       { klass_oop_store(&_protection_domain, pd); }
 529 
 530   // host class
 531   Klass* host_klass() const              {
 532     Klass** hk = (Klass**)adr_host_klass();
 533     if (hk == NULL) {
 534       return NULL;
 535     } else {
 536       return *hk;
 537     }
 538   }
 539   void set_host_klass(Klass* host)            {
 540     assert(is_anonymous(), "not anonymous");
 541     Klass** addr = (Klass**)adr_host_klass();
 542     assert(addr != NULL, "no reversed space");
 543     if (addr != NULL) {
 544       *addr = host;
 545     }
 546   }
 547   bool is_anonymous() const                {
 548     return (_misc_flags & _misc_is_anonymous) != 0;
 549   }
 550   void set_is_anonymous(bool value)        {
 551     if (value) {
 552       _misc_flags |= _misc_is_anonymous;
 553     } else {
 554       _misc_flags &= ~_misc_is_anonymous;
 555     }
 556   }
 557 
 558   // Oop that keeps the metadata for this class from being unloaded
 559   // in places where the metadata is stored in other places, like nmethods
 560   oop klass_holder() const {
 561     return is_anonymous() ? java_mirror() : class_loader();
 562   }
 563 
 564   bool is_contended() const                {
 565     return (_misc_flags & _misc_is_contended) != 0;
 566   }
 567   void set_is_contended(bool value)        {
 568     if (value) {
 569       _misc_flags |= _misc_is_contended;
 570     } else {
 571       _misc_flags &= ~_misc_is_contended;
 572     }
 573   }
 574 
 575   // signers
 576   objArrayOop signers() const              { return _signers; }
 577   void set_signers(objArrayOop s)          { klass_oop_store((oop*)&_signers, s); }
 578 
 579   // source file name
 580   Symbol* source_file_name() const         { return _source_file_name; }
 581   void set_source_file_name(Symbol* n);
 582 
 583   // minor and major version numbers of class file
 584   u2 minor_version() const                 { return _minor_version; }
 585   void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
 586   u2 major_version() const                 { return _major_version; }
 587   void set_major_version(u2 major_version) { _major_version = major_version; }
 588 
 589   // source debug extension
 590   char* source_debug_extension() const     { return _source_debug_extension; }
 591   void set_source_debug_extension(char* array, int length);
 592 
 593   // symbol unloading support (refcount already added)
 594   Symbol* array_name()                     { return _array_name; }
 595   void set_array_name(Symbol* name)        { assert(_array_name == NULL  || name == NULL, "name already created"); _array_name = name; }
 596 
 597   // nonstatic oop-map blocks
 598   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 599     return oop_map_count * OopMapBlock::size_in_words();
 600   }
 601   unsigned int nonstatic_oop_map_count() const {
 602     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 603   }
 604   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 605   void set_nonstatic_oop_map_size(int words) {
 606     _nonstatic_oop_map_size = words;
 607   }
 608 
 609   // RedefineClasses() support for previous versions:
 610   void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
 611          int emcp_method_count);
 612   // If the _previous_versions array is non-NULL, then this klass
 613   // has been redefined at least once even if we aren't currently
 614   // tracking a previous version.
 615   bool has_been_redefined() const { return _previous_versions != NULL; }
 616   bool has_previous_version() const;
 617   void init_previous_versions() {
 618     _previous_versions = NULL;
 619   }
 620   GrowableArray<PreviousVersionNode *>* previous_versions() const {
 621     return _previous_versions;
 622   }
 623 
 624   static void purge_previous_versions(InstanceKlass* ik);
 625 
 626   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 627   void set_cached_class_file(unsigned char *class_file_bytes,
 628                              jint class_file_len)     { _cached_class_file_len = class_file_len;
 629                                                         _cached_class_file_bytes = class_file_bytes; }
 630   jint get_cached_class_file_len()                    { return _cached_class_file_len; }
 631   unsigned char * get_cached_class_file_bytes()       { return _cached_class_file_bytes; }
 632 
 633   // JVMTI: Support for caching of field indices, types, and offsets
 634   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 635     _jvmti_cached_class_field_map = descriptor;
 636   }
 637   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 638     return _jvmti_cached_class_field_map;
 639   }
 640 
 641   bool has_default_methods() const {
 642     return (_misc_flags & _misc_has_default_methods) != 0;
 643   }
 644   void set_has_default_methods(bool b) {
 645     if (b) {
 646       _misc_flags |= _misc_has_default_methods;
 647     } else {
 648       _misc_flags &= ~_misc_has_default_methods;
 649     }
 650   }
 651 
 652   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 653   inline u2 next_method_idnum();
 654   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 655 
 656   // generics support
 657   Symbol* generic_signature() const                   { return _generic_signature; }
 658   void set_generic_signature(Symbol* sig)             { _generic_signature = sig; }
 659 
 660   u2 enclosing_method_data(int offset);
 661   u2 enclosing_method_class_index() {
 662     return enclosing_method_data(enclosing_method_class_index_offset);
 663   }
 664   u2 enclosing_method_method_index() {
 665     return enclosing_method_data(enclosing_method_method_index_offset);
 666   }
 667   void set_enclosing_method_indices(u2 class_index,
 668                                     u2 method_index);
 669 
 670   // jmethodID support
 671   static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
 672                      methodHandle method_h);
 673   static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
 674                      size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
 675                      jmethodID* to_dealloc_id_p,
 676                      jmethodID** to_dealloc_jmeths_p);
 677   static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
 678                 size_t *length_p, jmethodID* id_p);
 679   jmethodID jmethod_id_or_null(Method* method);
 680 
 681   // cached itable index support
 682   void set_cached_itable_index(size_t idnum, int index);
 683   int cached_itable_index(size_t idnum);
 684 
 685   // annotations support
 686   Annotations* annotations() const          { return _annotations; }
 687   void set_annotations(Annotations* anno)   { _annotations = anno; }
 688 
 689   AnnotationArray* class_annotations() const {
 690     return (_annotations != NULL) ? _annotations->class_annotations() : NULL;
 691   }
 692   Array<AnnotationArray*>* fields_annotations() const {
 693     return (_annotations != NULL) ? _annotations->fields_annotations() : NULL;
 694   }
 695   AnnotationArray* class_type_annotations() const {
 696     return (_annotations != NULL) ? _annotations->class_type_annotations() : NULL;
 697   }
 698   Array<AnnotationArray*>* fields_type_annotations() const {
 699     return (_annotations != NULL) ? _annotations->fields_type_annotations() : NULL;
 700   }
 701   // allocation
 702   instanceOop allocate_instance(TRAPS);
 703 
 704   // additional member function to return a handle
 705   instanceHandle allocate_instance_handle(TRAPS)      { return instanceHandle(THREAD, allocate_instance(THREAD)); }
 706 
 707   objArrayOop allocate_objArray(int n, int length, TRAPS);
 708   // Helper function
 709   static instanceOop register_finalizer(instanceOop i, TRAPS);
 710 
 711   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 712   // if not, throw either an Error or an Exception.
 713   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 714 
 715   // initialization
 716   void call_class_initializer(TRAPS);
 717   void set_initialization_state_and_notify(ClassState state, TRAPS);
 718 
 719   // OopMapCache support
 720   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 721   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 722   void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
 723 
 724   // JNI identifier support (for static fields - for jni performance)
 725   JNIid* jni_ids()                               { return _jni_ids; }
 726   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 727   JNIid* jni_id_for(int offset);
 728 
 729   // maintenance of deoptimization dependencies
 730   int mark_dependent_nmethods(DepChange& changes);
 731   void add_dependent_nmethod(nmethod* nm);
 732   void remove_dependent_nmethod(nmethod* nm);
 733 
 734   // On-stack replacement support
 735   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 736   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 737   void add_osr_nmethod(nmethod* n);
 738   void remove_osr_nmethod(nmethod* n);
 739   nmethod* lookup_osr_nmethod(Method* const m, int bci, int level, bool match_level) const;
 740 
 741   // Breakpoint support (see methods on Method* for details)
 742   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 743   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 744 
 745   // support for stub routines
 746   static ByteSize init_state_offset()  { return in_ByteSize(offset_of(InstanceKlass, _init_state)); }
 747   TRACE_DEFINE_OFFSET;
 748   static ByteSize init_thread_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_thread)); }
 749 
 750   // subclass/subinterface checks
 751   bool implements_interface(Klass* k) const;
 752 
 753   // Access to the implementor of an interface.
 754   Klass* implementor() const
 755   {
 756     Klass** k = adr_implementor();
 757     if (k == NULL) {
 758       return NULL;
 759     } else {
 760       return *k;
 761     }
 762   }
 763 
 764   void set_implementor(Klass* k) {
 765     assert(is_interface(), "not interface");
 766     Klass** addr = adr_implementor();
 767     assert(addr != NULL, "null addr");
 768     if (addr != NULL) {
 769       *addr = k;
 770     }
 771   }
 772 
 773   int  nof_implementors() const       {
 774     Klass* k = implementor();
 775     if (k == NULL) {
 776       return 0;
 777     } else if (k != this) {
 778       return 1;
 779     } else {
 780       return 2;
 781     }
 782   }
 783 
 784   void add_implementor(Klass* k);  // k is a new class that implements this interface
 785   void init_implementor();           // initialize
 786 
 787   // link this class into the implementors list of every interface it implements
 788   void process_interfaces(Thread *thread);
 789 
 790   // virtual operations from Klass
 791   bool is_leaf_class() const               { return _subklass == NULL; }
 792   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
 793   bool compute_is_subtype_of(Klass* k);
 794   bool can_be_primary_super_slow() const;
 795   int oop_size(oop obj)  const             { return size_helper(); }
 796   bool oop_is_instance_slow() const        { return true; }
 797 
 798   // Iterators
 799   void do_local_static_fields(FieldClosure* cl);
 800   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
 801   void do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS);
 802 
 803   void methods_do(void f(Method* method));
 804   void array_klasses_do(void f(Klass* k));
 805   void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
 806   void with_array_klasses_do(void f(Klass* k));
 807   bool super_types_do(SuperTypeClosure* blk);
 808 
 809   // Casting from Klass*
 810   static InstanceKlass* cast(Klass* k) {
 811     assert(k->is_klass(), "must be");
 812     assert(k->oop_is_instance(), "cast to InstanceKlass");
 813     return (InstanceKlass*) k;
 814   }
 815 
 816   InstanceKlass* java_super() const {
 817     return (super() == NULL) ? NULL : cast(super());
 818   }
 819 
 820   // Sizing (in words)
 821   static int header_size()            { return align_object_offset(sizeof(InstanceKlass)/HeapWordSize); }
 822 
 823   static int size(int vtable_length, int itable_length,
 824                   int nonstatic_oop_map_size,
 825                   bool is_interface, bool is_anonymous) {
 826     return align_object_size(header_size() +
 827            align_object_offset(vtable_length) +
 828            align_object_offset(itable_length) +
 829            ((is_interface || is_anonymous) ?
 830              align_object_offset(nonstatic_oop_map_size) :
 831              nonstatic_oop_map_size) +
 832            (is_interface ? (int)sizeof(Klass*)/HeapWordSize : 0) +
 833            (is_anonymous ? (int)sizeof(Klass*)/HeapWordSize : 0));
 834   }
 835   int size() const                    { return size(vtable_length(),
 836                                                itable_length(),
 837                                                nonstatic_oop_map_size(),
 838                                                is_interface(),
 839                                                is_anonymous());
 840   }
 841 #if INCLUDE_SERVICES
 842   virtual void collect_statistics(KlassSizeStats *sz) const;
 843 #endif
 844 
 845   static int vtable_start_offset()    { return header_size(); }
 846   static int vtable_length_offset()   { return offset_of(InstanceKlass, _vtable_len) / HeapWordSize; }
 847 
 848   intptr_t* start_of_vtable() const        { return ((intptr_t*)this) + vtable_start_offset(); }
 849   intptr_t* start_of_itable() const        { return start_of_vtable() + align_object_offset(vtable_length()); }
 850   int  itable_offset_in_words() const { return start_of_itable() - (intptr_t*)this; }
 851 
 852   intptr_t* end_of_itable() const          { return start_of_itable() + itable_length(); }
 853 
 854   address static_field_addr(int offset);
 855 
 856   OopMapBlock* start_of_nonstatic_oop_maps() const {
 857     return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
 858   }
 859 
 860   Klass** end_of_nonstatic_oop_maps() const {
 861     return (Klass**)(start_of_nonstatic_oop_maps() +
 862                      nonstatic_oop_map_count());
 863   }
 864 
 865   Klass** adr_implementor() const {
 866     if (is_interface()) {
 867       return (Klass**)end_of_nonstatic_oop_maps();
 868     } else {
 869       return NULL;
 870     }
 871   };
 872 
 873   Klass** adr_host_klass() const {
 874     if (is_anonymous()) {
 875       Klass** adr_impl = adr_implementor();
 876       if (adr_impl != NULL) {
 877         return adr_impl + 1;
 878       } else {
 879         return end_of_nonstatic_oop_maps();
 880       }
 881     } else {
 882       return NULL;
 883     }
 884   }
 885 
 886   // Allocation profiling support
 887   juint alloc_size() const            { return _alloc_count * size_helper(); }
 888   void set_alloc_size(juint n)        {}
 889 
 890   // Use this to return the size of an instance in heap words:
 891   int size_helper() const {
 892     return layout_helper_to_size_helper(layout_helper());
 893   }
 894 
 895   // This bit is initialized in classFileParser.cpp.
 896   // It is false under any of the following conditions:
 897   //  - the class is abstract (including any interface)
 898   //  - the class has a finalizer (if !RegisterFinalizersAtInit)
 899   //  - the class size is larger than FastAllocateSizeLimit
 900   //  - the class is java/lang/Class, which cannot be allocated directly
 901   bool can_be_fastpath_allocated() const {
 902     return !layout_helper_needs_slow_path(layout_helper());
 903   }
 904 
 905   // Java vtable/itable
 906   klassVtable* vtable() const;        // return new klassVtable wrapper
 907   inline Method* method_at_vtable(int index);
 908   klassItable* itable() const;        // return new klassItable wrapper
 909   Method* method_at_itable(Klass* holder, int index, TRAPS);
 910 
 911   // Garbage collection
 912   virtual void oops_do(OopClosure* cl);
 913 
 914   void oop_follow_contents(oop obj);
 915   int  oop_adjust_pointers(oop obj);
 916 
 917   void clean_implementors_list(BoolObjectClosure* is_alive);
 918   void clean_method_data(BoolObjectClosure* is_alive);
 919 
 920   // Explicit metaspace deallocation of fields
 921   // For RedefineClasses and class file parsing errors, we need to deallocate
 922   // instanceKlasses and the metadata they point to.
 923   void deallocate_contents(ClassLoaderData* loader_data);
 924   static void deallocate_methods(ClassLoaderData* loader_data,
 925                                  Array<Method*>* methods);
 926   void static deallocate_interfaces(ClassLoaderData* loader_data,
 927                                     Klass* super_klass,
 928                                     Array<Klass*>* local_interfaces,
 929                                     Array<Klass*>* transitive_interfaces);
 930 
 931   // The constant pool is on stack if any of the methods are executing or
 932   // referenced by handles.
 933   bool on_stack() const { return _constants->on_stack(); }
 934 
 935   void release_C_heap_structures();
 936 
 937   // Parallel Scavenge and Parallel Old
 938   PARALLEL_GC_DECLS
 939 
 940   // Naming
 941   const char* signature_name() const;
 942 
 943   // Iterators
 944   int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) {
 945     return oop_oop_iterate_v(obj, blk);
 946   }
 947 
 948   int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) {
 949     return oop_oop_iterate_v_m(obj, blk, mr);
 950   }
 951 
 952 #define InstanceKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)      \
 953   int  oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk);           \
 954   int  oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk,        \
 955                                       MemRegion mr);
 956 
 957   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DECL)
 958   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DECL)
 959 
 960 #if INCLUDE_ALL_GCS
 961 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
 962   int  oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
 963 
 964   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
 965   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
 966 #endif // INCLUDE_ALL_GCS
 967 
 968   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
 969 private:
 970   // initialization state
 971 #ifdef ASSERT
 972   void set_init_state(ClassState state);
 973 #else
 974   void set_init_state(ClassState state) { _init_state = (u1)state; }
 975 #endif
 976   void set_rewritten()                  { _misc_flags |= _misc_rewritten; }
 977   void set_init_thread(Thread *thread)  { _init_thread = thread; }
 978 
 979   // The RedefineClasses() API can cause new method idnums to be needed
 980   // which will cause the caches to grow. Safety requires different
 981   // cache management logic if the caches can grow instead of just
 982   // going from NULL to non-NULL.
 983   bool idnum_can_increment() const      { return has_been_redefined(); }
 984   jmethodID* methods_jmethod_ids_acquire() const
 985          { return (jmethodID*)OrderAccess::load_ptr_acquire(&_methods_jmethod_ids); }
 986   void release_set_methods_jmethod_ids(jmethodID* jmeths)
 987          { OrderAccess::release_store_ptr(&_methods_jmethod_ids, jmeths); }
 988 
 989   int* methods_cached_itable_indices_acquire() const
 990          { return (int*)OrderAccess::load_ptr_acquire(&_methods_cached_itable_indices); }
 991   void release_set_methods_cached_itable_indices(int* indices)
 992          { OrderAccess::release_store_ptr(&_methods_cached_itable_indices, indices); }
 993 
 994   // Lock during initialization
 995   volatile oop init_lock() const;
 996   void set_init_lock(oop value)      { klass_oop_store(&_init_lock, value); }
 997   void fence_and_clear_init_lock();  // after fully_initialized
 998 
 999   // Offsets for memory management
1000   oop* adr_protection_domain() const { return (oop*)&this->_protection_domain;}
1001   oop* adr_signers() const           { return (oop*)&this->_signers;}
1002   oop* adr_init_lock() const         { return (oop*)&this->_init_lock;}
1003 
1004   // Static methods that are used to implement member methods where an exposed this pointer
1005   // is needed due to possible GCs
1006   static bool link_class_impl                           (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
1007   static bool verify_code                               (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
1008   static void initialize_impl                           (instanceKlassHandle this_oop, TRAPS);
1009   static void eager_initialize_impl                     (instanceKlassHandle this_oop);
1010   static void set_initialization_state_and_notify_impl  (instanceKlassHandle this_oop, ClassState state, TRAPS);
1011   static void call_class_initializer_impl               (instanceKlassHandle this_oop, TRAPS);
1012   static Klass* array_klass_impl                      (instanceKlassHandle this_oop, bool or_null, int n, TRAPS);
1013   static void do_local_static_fields_impl               (instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS);
1014   /* jni_id_for_impl for jfieldID only */
1015   static JNIid* jni_id_for_impl                         (instanceKlassHandle this_oop, int offset);
1016 
1017   // Returns the array class for the n'th dimension
1018   Klass* array_klass_impl(bool or_null, int n, TRAPS);
1019 
1020   // Returns the array class with this class as element type
1021   Klass* array_klass_impl(bool or_null, TRAPS);
1022 
1023 public:
1024   // CDS support - remove and restore oops from metadata. Oops are not shared.
1025   virtual void remove_unshareable_info();
1026   virtual void restore_unshareable_info(TRAPS);
1027 
1028   // jvm support
1029   jint compute_modifier_flags(TRAPS) const;
1030 
1031 public:
1032   // JVMTI support
1033   jint jvmti_class_status() const;
1034 
1035  public:
1036   // Printing
1037 #ifndef PRODUCT
1038   void print_on(outputStream* st) const;
1039 #endif
1040   void print_value_on(outputStream* st) const;
1041 
1042   void oop_print_value_on(oop obj, outputStream* st);
1043 
1044 #ifndef PRODUCT
1045   void oop_print_on      (oop obj, outputStream* st);
1046 
1047   void print_dependent_nmethods(bool verbose = false);
1048   bool is_dependent_nmethod(nmethod* nm);
1049 #endif
1050 
1051   const char* internal_name() const;
1052 
1053   // Verification
1054   void verify_on(outputStream* st);
1055 
1056   void oop_verify_on(oop obj, outputStream* st);
1057 };
1058 
1059 inline Method* InstanceKlass::method_at_vtable(int index)  {
1060 #ifndef PRODUCT
1061   assert(index >= 0, "valid vtable index");
1062   if (DebugVtables) {
1063     verify_vtable_index(index);
1064   }
1065 #endif
1066   vtableEntry* ve = (vtableEntry*)start_of_vtable();
1067   return ve[index].method();
1068 }
1069 
1070 // for adding methods
1071 // UNSET_IDNUM return means no more ids available
1072 inline u2 InstanceKlass::next_method_idnum() {
1073   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1074     return ConstMethod::UNSET_IDNUM; // no more ids available
1075   } else {
1076     return _idnum_allocated_count++;
1077   }
1078 }
1079 
1080 
1081 /* JNIid class for jfieldIDs only */
1082 class JNIid: public CHeapObj<mtClass> {
1083   friend class VMStructs;
1084  private:
1085   Klass*             _holder;
1086   JNIid*             _next;
1087   int                _offset;
1088 #ifdef ASSERT
1089   bool               _is_static_field_id;
1090 #endif
1091 
1092  public:
1093   // Accessors
1094   Klass* holder() const           { return _holder; }
1095   int offset() const              { return _offset; }
1096   JNIid* next()                   { return _next; }
1097   // Constructor
1098   JNIid(Klass* holder, int offset, JNIid* next);
1099   // Identifier lookup
1100   JNIid* find(int offset);
1101 
1102   bool find_local_field(fieldDescriptor* fd) {
1103     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1104   }
1105 
1106   static void deallocate(JNIid* id);
1107   // Debugging
1108 #ifdef ASSERT
1109   bool is_static_field_id() const { return _is_static_field_id; }
1110   void set_is_static_field_id()   { _is_static_field_id = true; }
1111 #endif
1112   void verify(Klass* holder);
1113 };
1114 
1115 
1116 // If breakpoints are more numerous than just JVMTI breakpoints,
1117 // consider compressing this data structure.
1118 // It is currently a simple linked list defined in method.hpp.
1119 
1120 class BreakpointInfo;
1121 
1122 
1123 // A collection point for interesting information about the previous
1124 // version(s) of an InstanceKlass. This class uses weak references to
1125 // the information so that the information may be collected as needed
1126 // by the system. If the information is shared, then a regular
1127 // reference must be used because a weak reference would be seen as
1128 // collectible. A GrowableArray of PreviousVersionNodes is attached
1129 // to the InstanceKlass as needed. See PreviousVersionWalker below.
1130 class PreviousVersionNode : public CHeapObj<mtClass> {
1131  private:
1132   // A shared ConstantPool is never collected so we'll always have
1133   // a reference to it so we can update items in the cache. We'll
1134   // have a weak reference to a non-shared ConstantPool until all
1135   // of the methods (EMCP or obsolete) have been collected; the
1136   // non-shared ConstantPool becomes collectible at that point.
1137   ConstantPool*    _prev_constant_pool;  // regular or weak reference
1138   bool    _prev_cp_is_weak;     // true if not a shared ConstantPool
1139 
1140   // If the previous version of the InstanceKlass doesn't have any
1141   // EMCP methods, then _prev_EMCP_methods will be NULL. If all the
1142   // EMCP methods have been collected, then _prev_EMCP_methods can
1143   // have a length of zero.
1144   GrowableArray<Method*>* _prev_EMCP_methods;
1145 
1146 public:
1147   PreviousVersionNode(ConstantPool* prev_constant_pool, bool prev_cp_is_weak,
1148     GrowableArray<Method*>* prev_EMCP_methods);
1149   ~PreviousVersionNode();
1150   ConstantPool* prev_constant_pool() const {
1151     return _prev_constant_pool;
1152   }
1153   GrowableArray<Method*>* prev_EMCP_methods() const {
1154     return _prev_EMCP_methods;
1155   }
1156 };
1157 
1158 
1159 // A Handle-ized version of PreviousVersionNode.
1160 class PreviousVersionInfo : public ResourceObj {
1161  private:
1162   constantPoolHandle   _prev_constant_pool_handle;
1163   // If the previous version of the InstanceKlass doesn't have any
1164   // EMCP methods, then _prev_EMCP_methods will be NULL. Since the
1165   // methods cannot be collected while we hold a handle,
1166   // _prev_EMCP_methods should never have a length of zero.
1167   GrowableArray<methodHandle>* _prev_EMCP_method_handles;
1168 
1169 public:
1170   PreviousVersionInfo(PreviousVersionNode *pv_node);
1171   ~PreviousVersionInfo();
1172   constantPoolHandle prev_constant_pool_handle() const {
1173     return _prev_constant_pool_handle;
1174   }
1175   GrowableArray<methodHandle>* prev_EMCP_method_handles() const {
1176     return _prev_EMCP_method_handles;
1177   }
1178 };
1179 
1180 
1181 // Helper object for walking previous versions. This helper cleans up
1182 // the Handles that it allocates when the helper object is destroyed.
1183 // The PreviousVersionInfo object returned by next_previous_version()
1184 // is only valid until a subsequent call to next_previous_version() or
1185 // the helper object is destroyed.
1186 class PreviousVersionWalker : public StackObj {
1187  private:
1188   GrowableArray<PreviousVersionNode *>* _previous_versions;
1189   int                                   _current_index;
1190   // Fields for cleaning up when we are done walking the previous versions:
1191   // A HandleMark for the PreviousVersionInfo handles:
1192   HandleMark                            _hm;
1193 
1194   // It would be nice to have a ResourceMark field in this helper also,
1195   // but the ResourceMark code says to be careful to delete handles held
1196   // in GrowableArrays _before_ deleting the GrowableArray. Since we
1197   // can't guarantee the order in which the fields are destroyed, we
1198   // have to let the creator of the PreviousVersionWalker object do
1199   // the right thing. Also, adding a ResourceMark here causes an
1200   // include loop.
1201 
1202   // A pointer to the current info object so we can handle the deletes.
1203   PreviousVersionInfo *                 _current_p;
1204 
1205  public:
1206   PreviousVersionWalker(InstanceKlass *ik);
1207   ~PreviousVersionWalker();
1208 
1209   // Return the interesting information for the next previous version
1210   // of the klass. Returns NULL if there are no more previous versions.
1211   PreviousVersionInfo* next_previous_version();
1212 };
1213 
1214 
1215 //
1216 // nmethodBucket is used to record dependent nmethods for
1217 // deoptimization.  nmethod dependencies are actually <klass, method>
1218 // pairs but we really only care about the klass part for purposes of
1219 // finding nmethods which might need to be deoptimized.  Instead of
1220 // recording the method, a count of how many times a particular nmethod
1221 // was recorded is kept.  This ensures that any recording errors are
1222 // noticed since an nmethod should be removed as many times are it's
1223 // added.
1224 //
1225 class nmethodBucket: public CHeapObj<mtClass> {
1226   friend class VMStructs;
1227  private:
1228   nmethod*       _nmethod;
1229   int            _count;
1230   nmethodBucket* _next;
1231 
1232  public:
1233   nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
1234     _nmethod = nmethod;
1235     _next = next;
1236     _count = 1;
1237   }
1238   int count()                             { return _count; }
1239   int increment()                         { _count += 1; return _count; }
1240   int decrement()                         { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
1241   nmethodBucket* next()                   { return _next; }
1242   void set_next(nmethodBucket* b)         { _next = b; }
1243   nmethod* get_nmethod()                  { return _nmethod; }
1244 };
1245 
1246 // An iterator that's used to access the inner classes indices in the
1247 // InstanceKlass::_inner_classes array.
1248 class InnerClassesIterator : public StackObj {
1249  private:
1250   Array<jushort>* _inner_classes;
1251   int _length;
1252   int _idx;
1253  public:
1254 
1255   InnerClassesIterator(instanceKlassHandle k) {
1256     _inner_classes = k->inner_classes();
1257     if (k->inner_classes() != NULL) {
1258       _length = _inner_classes->length();
1259       // The inner class array's length should be the multiple of
1260       // inner_class_next_offset if it only contains the InnerClasses
1261       // attribute data, or it should be
1262       // n*inner_class_next_offset+enclosing_method_attribute_size
1263       // if it also contains the EnclosingMethod data.
1264       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1265               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1266              "just checking");
1267       // Remove the enclosing_method portion if exists.
1268       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1269         _length -= InstanceKlass::enclosing_method_attribute_size;
1270       }
1271     } else {
1272       _length = 0;
1273     }
1274     _idx = 0;
1275   }
1276 
1277   int length() const {
1278     return _length;
1279   }
1280 
1281   void next() {
1282     _idx += InstanceKlass::inner_class_next_offset;
1283   }
1284 
1285   bool done() const {
1286     return (_idx >= _length);
1287   }
1288 
1289   u2 inner_class_info_index() const {
1290     return _inner_classes->at(
1291                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1292   }
1293 
1294   void set_inner_class_info_index(u2 index) {
1295     _inner_classes->at_put(
1296                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1297   }
1298 
1299   u2 outer_class_info_index() const {
1300     return _inner_classes->at(
1301                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1302   }
1303 
1304   void set_outer_class_info_index(u2 index) {
1305     _inner_classes->at_put(
1306                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1307   }
1308 
1309   u2 inner_name_index() const {
1310     return _inner_classes->at(
1311                _idx + InstanceKlass::inner_class_inner_name_offset);
1312   }
1313 
1314   void set_inner_name_index(u2 index) {
1315     _inner_classes->at_put(
1316                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1317   }
1318 
1319   u2 inner_access_flags() const {
1320     return _inner_classes->at(
1321                _idx + InstanceKlass::inner_class_access_flags_offset);
1322   }
1323 };
1324 
1325 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP