src/share/vm/oops/instanceKlass.hpp

Wed, 22 May 2013 14:37:49 -0400

author
coleenp
date
Wed, 22 May 2013 14:37:49 -0400
changeset 5176
6bd680e9ea35
parent 5097
92ef81e2f571
child 5178
b7fa10a3a69a
permissions
-rw-r--r--

8003421: NPG: Move oops out of InstanceKlass into mirror
Summary: Inject protection_domain, signers, init_lock into java_lang_Class
Reviewed-by: stefank, dholmes, sla

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

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