src/share/vm/oops/instanceKlass.hpp

Fri, 08 Mar 2013 11:47:57 -0500

author
coleenp
date
Fri, 08 Mar 2013 11:47:57 -0500
changeset 4712
3efdfd6ddbf2
parent 4572
927a311d00f9
child 4714
35ef86296a5d
permissions
-rw-r--r--

8003553: NPG: metaspace objects should be zeroed in constructors
Summary: Zero metadata in constructors, not in allocation (and some in constructors)
Reviewed-by: jmasa, sspitsyn

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

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