src/share/vm/oops/instanceKlass.hpp

Wed, 03 Jul 2013 17:26:59 -0400

author
jiangli
date
Wed, 03 Jul 2013 17:26:59 -0400
changeset 5369
71180a6e5080
parent 5307
e0c9a1d29eb4
child 5421
825e6cb66923
permissions
-rw-r--r--

7133260: AllocationProfiler uses space in metadata and doesn't seem to do anything useful.
Summary: Remove -Xaprof and Klass::_alloc_count & ArrayKlass::_alloc_size.
Reviewed-by: stefank, coleenp

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

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