jdk8-mips64-public/hotspot: src/share/vm/oops/klass.hpp@2c6ef90f030a (annotated)

src/share/vm/oops/klass.hpp@2c6ef90f030a (annotated)

src/share/vm/oops/klass.hpp

Mon, 07 Jul 2014 10:12:40 +0200

author: stefank
date: Mon, 07 Jul 2014 10:12:40 +0200
changeset 6992: 2c6ef90f030a
parent 6976: 76b588255908
child 7089: 6e0cb14ce59b
permissions: -rw-r--r--

8049421: G1 Class Unloading after completing a concurrent mark cycle
Reviewed-by: tschatzl, ehelin, brutisso, coleenp, roland, iveresov
Contributed-by: stefan.karlsson@oracle.com, mikael.gerdin@oracle.com

 /*
  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #ifndef SHARE_VM_OOPS_KLASS_HPP
 #define SHARE_VM_OOPS_KLASS_HPP
 #include "memory/genOopClosures.hpp"
 #include "memory/iterator.hpp"
 #include "memory/memRegion.hpp"
 #include "memory/specialized_oop_closures.hpp"
 #include "oops/klassPS.hpp"
 #include "oops/metadata.hpp"
 #include "oops/oop.hpp"
 #include "trace/traceMacros.hpp"
 #include "utilities/accessFlags.hpp"
 #include "utilities/macros.hpp"
 #if INCLUDE_ALL_GCS
 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp"
 #include "gc_implementation/g1/g1OopClosures.hpp"
 #include "gc_implementation/parNew/parOopClosures.hpp"
 #endif // INCLUDE_ALL_GCS
 //
 // A Klass provides:
 //  1: language level class object (method dictionary etc.)
 //  2: provide vm dispatch behavior for the object
 // Both functions are combined into one C++ class.
 // One reason for the oop/klass dichotomy in the implementation is
 // that we don't want a C++ vtbl pointer in every object.  Thus,
 // normal oops don't have any virtual functions.  Instead, they
 // forward all "virtual" functions to their klass, which does have
 // a vtbl and does the C++ dispatch depending on the object's
 // actual type.  (See oop.inline.hpp for some of the forwarding code.)
 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"!
 //  Klass layout:
 //    [C++ vtbl ptr  ] (contained in Metadata)
 //    [layout_helper ]
 //    [super_check_offset   ] for fast subtype checks
 //    [name          ]
 //    [secondary_super_cache] for fast subtype checks
 //    [secondary_supers     ] array of 2ndary supertypes
 //    [primary_supers 0]
 //    [primary_supers 1]
 //    [primary_supers 2]
 //    ...
 //    [primary_supers 7]
 //    [java_mirror   ]
 //    [super         ]
 //    [subklass      ] first subclass
 //    [next_sibling  ] link to chain additional subklasses
 //    [next_link     ]
 //    [class_loader_data]
 //    [modifier_flags]
 //    [access_flags  ]
 //    [last_biased_lock_bulk_revocation_time] (64 bits)
 //    [prototype_header]
 //    [biased_lock_revocation_count]
 //    [_modified_oops]
 //    [_accumulated_modified_oops]
 //    [trace_id]
 // Forward declarations.
 template <class T> class Array;
 template <class T> class GrowableArray;
 class ClassLoaderData;
 class klassVtable;
 class ParCompactionManager;
 class KlassSizeStats;
 class Klass : public Metadata {
   friend class VMStructs;
  protected:
   // note: put frequently-used fields together at start of klass structure
   // for better cache behavior (may not make much of a difference but sure won't hurt)
   enum { _primary_super_limit = 8 };
   // The "layout helper" is a combined descriptor of object layout.
   // For klasses which are neither instance nor array, the value is zero.
   //
   // For instances, layout helper is a positive number, the instance size.
   // This size is already passed through align_object_size and scaled to bytes.
   // The low order bit is set if instances of this class cannot be
   // allocated using the fastpath.
   //
   // For arrays, layout helper is a negative number, containing four
   // distinct bytes, as follows:
   //    MSB:[tag, hsz, ebt, log2(esz)]:LSB
   // where:
   //    tag is 0x80 if the elements are oops, 0xC0 if non-oops
   //    hsz is array header size in bytes (i.e., offset of first element)
   //    ebt is the BasicType of the elements
   //    esz is the element size in bytes
   // This packed word is arranged so as to be quickly unpacked by the
   // various fast paths that use the various subfields.
   //
   // The esz bits can be used directly by a SLL instruction, without masking.
   //
   // Note that the array-kind tag looks like 0x00 for instance klasses,
   // since their length in bytes is always less than 24Mb.
   //
   // Final note:  This comes first, immediately after C++ vtable,
   // because it is frequently queried.
   jint        _layout_helper;
   // The fields _super_check_offset, _secondary_super_cache, _secondary_supers
   // and _primary_supers all help make fast subtype checks.  See big discussion
   // in doc/server_compiler/checktype.txt
   //
   // Where to look to observe a supertype (it is &_secondary_super_cache for
   // secondary supers, else is &_primary_supers[depth()].
   juint       _super_check_offset;
   // Class name.  Instance classes: java/lang/String, etc.  Array classes: [I,
   // [Ljava/lang/String;, etc.  Set to zero for all other kinds of classes.
   Symbol*     _name;
   // Cache of last observed secondary supertype
   Klass*      _secondary_super_cache;
   // Array of all secondary supertypes
   Array<Klass*>* _secondary_supers;
   // Ordered list of all primary supertypes
   Klass*      _primary_supers[_primary_super_limit];
   // java/lang/Class instance mirroring this class
   oop       _java_mirror;
   // Superclass
   Klass*      _super;
   // First subclass (NULL if none); _subklass->next_sibling() is next one
   Klass*      _subklass;
   // Sibling link (or NULL); links all subklasses of a klass
   Klass*      _next_sibling;
   // All klasses loaded by a class loader are chained through these links
   Klass*      _next_link;
   // The VM's representation of the ClassLoader used to load this class.
   // Provide access the corresponding instance java.lang.ClassLoader.
   ClassLoaderData* _class_loader_data;
   jint        _modifier_flags;  // Processed access flags, for use by Class.getModifiers.
   AccessFlags _access_flags;    // Access flags. The class/interface distinction is stored here.
   // Biased locking implementation and statistics
   // (the 64-bit chunk goes first, to avoid some fragmentation)
   jlong    _last_biased_lock_bulk_revocation_time;
   markOop  _prototype_header;   // Used when biased locking is both enabled and disabled for this type
   jint     _biased_lock_revocation_count;
   TRACE_DEFINE_KLASS_TRACE_ID;
   // Remembered sets support for the oops in the klasses.
   jbyte _modified_oops;             // Card Table Equivalent (YC/CMS support)
   jbyte _accumulated_modified_oops; // Mod Union Equivalent (CMS support)
   // Constructor
   Klass();
   void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw();
  public:
   enum MethodLookupMode { normal, skip_overpass, skip_defaults };
   bool is_klass() const volatile { return true; }
   // super
   Klass* super() const               { return _super; }
   void set_super(Klass* k)           { _super = k; }
   // initializes _super link, _primary_supers & _secondary_supers arrays
   void initialize_supers(Klass* k, TRAPS);
   void initialize_supers_impl1(Klass* k);
   void initialize_supers_impl2(Klass* k);
   // klass-specific helper for initializing _secondary_supers
   virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
   // java_super is the Java-level super type as specified by Class.getSuperClass.
   virtual Klass* java_super() const  { return NULL; }
   juint    super_check_offset() const  { return _super_check_offset; }
   void set_super_check_offset(juint o) { _super_check_offset = o; }
   Klass* secondary_super_cache() const     { return _secondary_super_cache; }
   void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; }
   Array<Klass*>* secondary_supers() const { return _secondary_supers; }
   void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; }
   // Return the element of the _super chain of the given depth.
   // If there is no such element, return either NULL or this.
   Klass* primary_super_of_depth(juint i) const {
     assert(i < primary_super_limit(), "oob");
     Klass* super = _primary_supers[i];
     assert(super == NULL || super->super_depth() == i, "correct display");
     return super;
   }
   // Can this klass be a primary super?  False for interfaces and arrays of
   // interfaces.  False also for arrays or classes with long super chains.
   bool can_be_primary_super() const {
     const juint secondary_offset = in_bytes(secondary_super_cache_offset());
     return super_check_offset() != secondary_offset;
   }
   virtual bool can_be_primary_super_slow() const;
   // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit].
   juint super_depth() const {
     if (!can_be_primary_super()) {
       return primary_super_limit();
     } else {
       juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*);
       assert(d < primary_super_limit(), "oob");
       assert(_primary_supers[d] == this, "proper init");
       return d;
     }
   }
   // store an oop into a field of a Klass
   void klass_oop_store(oop* p, oop v);
   void klass_oop_store(volatile oop* p, oop v);
   // java mirror
   oop java_mirror() const              { return _java_mirror; }
   void set_java_mirror(oop m) { klass_oop_store(&_java_mirror, m); }
   // modifier flags
   jint modifier_flags() const          { return _modifier_flags; }
   void set_modifier_flags(jint flags)  { _modifier_flags = flags; }
   // size helper
   int layout_helper() const            { return _layout_helper; }
   void set_layout_helper(int lh)       { _layout_helper = lh; }
   // Note: for instances layout_helper() may include padding.
   // Use InstanceKlass::contains_field_offset to classify field offsets.
   // sub/superklass links
   InstanceKlass* superklass() const;
   Klass* subklass() const;
   Klass* next_sibling() const;
   void append_to_sibling_list();           // add newly created receiver to superklass' subklass list
   void set_next_link(Klass* k) { _next_link = k; }
   Klass* next_link() const { return _next_link; }   // The next klass defined by the class loader.
   // class loader data
   ClassLoaderData* class_loader_data() const               { return _class_loader_data; }
   void set_class_loader_data(ClassLoaderData* loader_data) {  _class_loader_data = loader_data; }
   // The Klasses are not placed in the Heap, so the Card Table or
   // the Mod Union Table can't be used to mark when klasses have modified oops.
   // The CT and MUT bits saves this information for the individual Klasses.
   void record_modified_oops()            { _modified_oops = 1; }
   void clear_modified_oops()             { _modified_oops = 0; }
   bool has_modified_oops()               { return _modified_oops == 1; }
   void accumulate_modified_oops()        { if (has_modified_oops()) _accumulated_modified_oops = 1; }
   void clear_accumulated_modified_oops() { _accumulated_modified_oops = 0; }
   bool has_accumulated_modified_oops()   { return _accumulated_modified_oops == 1; }
  protected:                                // internal accessors
   Klass* subklass_oop() const            { return _subklass; }
   Klass* next_sibling_oop() const        { return _next_sibling; }
   void     set_subklass(Klass* s);
   void     set_next_sibling(Klass* s);
  public:
   // Compiler support
   static ByteSize super_offset()                 { return in_ByteSize(offset_of(Klass, _super)); }
   static ByteSize super_check_offset_offset()    { return in_ByteSize(offset_of(Klass, _super_check_offset)); }
   static ByteSize primary_supers_offset()        { return in_ByteSize(offset_of(Klass, _primary_supers)); }
   static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); }
   static ByteSize secondary_supers_offset()      { return in_ByteSize(offset_of(Klass, _secondary_supers)); }
   static ByteSize java_mirror_offset()           { return in_ByteSize(offset_of(Klass, _java_mirror)); }
   static ByteSize modifier_flags_offset()        { return in_ByteSize(offset_of(Klass, _modifier_flags)); }
   static ByteSize layout_helper_offset()         { return in_ByteSize(offset_of(Klass, _layout_helper)); }
   static ByteSize access_flags_offset()          { return in_ByteSize(offset_of(Klass, _access_flags)); }
   // Unpacking layout_helper:
   enum {
     _lh_neutral_value           = 0,  // neutral non-array non-instance value
     _lh_instance_slow_path_bit  = 0x01,
     _lh_log2_element_size_shift = BitsPerByte*0,
     _lh_log2_element_size_mask  = BitsPerLong-1,
     _lh_element_type_shift      = BitsPerByte*1,
     _lh_element_type_mask       = right_n_bits(BitsPerByte),  // shifted mask
     _lh_header_size_shift       = BitsPerByte*2,
     _lh_header_size_mask        = right_n_bits(BitsPerByte),  // shifted mask
     _lh_array_tag_bits          = 2,
     _lh_array_tag_shift         = BitsPerInt - _lh_array_tag_bits,
     _lh_array_tag_type_value    = ~0x00,  // 0xC0000000 >> 30
     _lh_array_tag_obj_value     = ~0x01   // 0x80000000 >> 30
   };
   static int layout_helper_size_in_bytes(jint lh) {
     assert(lh > (jint)_lh_neutral_value, "must be instance");
     return (int) lh & ~_lh_instance_slow_path_bit;
   }
   static bool layout_helper_needs_slow_path(jint lh) {
     assert(lh > (jint)_lh_neutral_value, "must be instance");
     return (lh & _lh_instance_slow_path_bit) != 0;
   }
   static bool layout_helper_is_instance(jint lh) {
     return (jint)lh > (jint)_lh_neutral_value;
   }
   static bool layout_helper_is_array(jint lh) {
     return (jint)lh < (jint)_lh_neutral_value;
   }
   static bool layout_helper_is_typeArray(jint lh) {
     // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift);
     return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift);
   }
   static bool layout_helper_is_objArray(jint lh) {
     // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift);
     return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift);
   }
   static int layout_helper_header_size(jint lh) {
     assert(lh < (jint)_lh_neutral_value, "must be array");
     int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask;
     assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity");
     return hsize;
   }
   static BasicType layout_helper_element_type(jint lh) {
     assert(lh < (jint)_lh_neutral_value, "must be array");
     int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask;
     assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity");
     return (BasicType) btvalue;
   }
   static int layout_helper_log2_element_size(jint lh) {
     assert(lh < (jint)_lh_neutral_value, "must be array");
     int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask;
     assert(l2esz <= LogBitsPerLong,
         err_msg("sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh));
     return l2esz;
   }
   static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) {
     return (tag        << _lh_array_tag_shift)
       |    (hsize      << _lh_header_size_shift)
       |    ((int)etype << _lh_element_type_shift)
       |    (log2_esize << _lh_log2_element_size_shift);
   }
   static jint instance_layout_helper(jint size, bool slow_path_flag) {
     return (size << LogHeapWordSize)
       |    (slow_path_flag ? _lh_instance_slow_path_bit : 0);
   }
   static int layout_helper_to_size_helper(jint lh) {
     assert(lh > (jint)_lh_neutral_value, "must be instance");
     // Note that the following expression discards _lh_instance_slow_path_bit.
     return lh >> LogHeapWordSize;
   }
   // Out-of-line version computes everything based on the etype:
   static jint array_layout_helper(BasicType etype);
   // What is the maximum number of primary superclasses any klass can have?
 #ifdef PRODUCT
   static juint primary_super_limit()         { return _primary_super_limit; }
 #else
   static juint primary_super_limit() {
     assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob");
     return FastSuperclassLimit;
   }
 #endif
   // vtables
   virtual klassVtable* vtable() const        { return NULL; }
   virtual int vtable_length() const          { return 0; }
   // subclass check
   bool is_subclass_of(const Klass* k) const;
   // subtype check: true if is_subclass_of, or if k is interface and receiver implements it
   bool is_subtype_of(Klass* k) const {
     juint    off = k->super_check_offset();
     Klass* sup = *(Klass**)( (address)this + off );
     const juint secondary_offset = in_bytes(secondary_super_cache_offset());
     if (sup == k) {
       return true;
     } else if (off != secondary_offset) {
       return false;
     } else {
       return search_secondary_supers(k);
     }
   }
   bool search_secondary_supers(Klass* k) const;
   // Find LCA in class hierarchy
   Klass *LCA( Klass *k );
   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
   // if not, throw either an Error or an Exception.
   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
   // array copying
   virtual void  copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
   // tells if the class should be initialized
   virtual bool should_be_initialized() const    { return false; }
   // initializes the klass
   virtual void initialize(TRAPS);
   // lookup operation for MethodLookupCache
   friend class MethodLookupCache;
   virtual Method* uncached_lookup_method(Symbol* name, Symbol* signature, MethodLookupMode mode) const;
  public:
   Method* lookup_method(Symbol* name, Symbol* signature) const {
     return uncached_lookup_method(name, signature, normal);
   }
   // array class with specific rank
   Klass* array_klass(int rank, TRAPS)         {  return array_klass_impl(false, rank, THREAD); }
   // array class with this klass as element type
   Klass* array_klass(TRAPS)                   {  return array_klass_impl(false, THREAD); }
   // These will return NULL instead of allocating on the heap:
   // NB: these can block for a mutex, like other functions with TRAPS arg.
   Klass* array_klass_or_null(int rank);
   Klass* array_klass_or_null();
   virtual oop protection_domain() const = 0;
   oop class_loader() const;
   virtual oop klass_holder() const      { return class_loader(); }
  protected:
   virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS);
   virtual Klass* array_klass_impl(bool or_null, TRAPS);
  public:
   // CDS support - remove and restore oops from metadata. Oops are not shared.
   virtual void remove_unshareable_info();
   virtual void restore_unshareable_info(TRAPS);
  protected:
   // computes the subtype relationship
   virtual bool compute_is_subtype_of(Klass* k);
  public:
   // subclass accessor (here for convenience; undefined for non-klass objects)
   virtual bool is_leaf_class() const { fatal("not a class"); return false; }
  public:
   // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP
   // These functions describe behavior for the oop not the KLASS.
   // actual oop size of obj in memory
   virtual int oop_size(oop obj) const = 0;
   // Size of klass in word size.
   virtual int size() const = 0;
 #if INCLUDE_SERVICES
   virtual void collect_statistics(KlassSizeStats *sz) const;
 #endif
   // Returns the Java name for a class (Resource allocated)
   // For arrays, this returns the name of the element with a leading '['.
   // For classes, this returns the name with the package separators
   //     turned into '.'s.
   const char* external_name() const;
   // Returns the name for a class (Resource allocated) as the class
   // would appear in a signature.
   // For arrays, this returns the name of the element with a leading '['.
   // For classes, this returns the name with a leading 'L' and a trailing ';'
   //     and the package separators as '/'.
   virtual const char* signature_name() const;
   // garbage collection support
   virtual void oop_follow_contents(oop obj) = 0;
   virtual int  oop_adjust_pointers(oop obj) = 0;
   // Parallel Scavenge and Parallel Old
   PARALLEL_GC_DECLS_PV
   // type testing operations
  protected:
   virtual bool oop_is_instance_slow()       const { return false; }
   virtual bool oop_is_array_slow()          const { return false; }
   virtual bool oop_is_objArray_slow()       const { return false; }
   virtual bool oop_is_typeArray_slow()      const { return false; }
  public:
   virtual bool oop_is_instanceClassLoader() const { return false; }
   virtual bool oop_is_instanceMirror()      const { return false; }
   virtual bool oop_is_instanceRef()         const { return false; }
   // Fast non-virtual versions
   #ifndef ASSERT
   #define assert_same_query(xval, xcheck) xval
   #else
  private:
   static bool assert_same_query(bool xval, bool xslow) {
     assert(xval == xslow, "slow and fast queries agree");
     return xval;
   }
  public:
   #endif
   inline  bool oop_is_instance()            const { return assert_same_query(
                                                     layout_helper_is_instance(layout_helper()),
                                                     oop_is_instance_slow()); }
   inline  bool oop_is_array()               const { return assert_same_query(
                                                     layout_helper_is_array(layout_helper()),
                                                     oop_is_array_slow()); }
   inline  bool oop_is_objArray()            const { return assert_same_query(
                                                     layout_helper_is_objArray(layout_helper()),
                                                     oop_is_objArray_slow()); }
   inline  bool oop_is_typeArray()           const { return assert_same_query(
                                                     layout_helper_is_typeArray(layout_helper()),
                                                     oop_is_typeArray_slow()); }
   #undef assert_same_query
   // Access flags
   AccessFlags access_flags() const         { return _access_flags;  }
   void set_access_flags(AccessFlags flags) { _access_flags = flags; }
   bool is_public() const                { return _access_flags.is_public(); }
   bool is_final() const                 { return _access_flags.is_final(); }
   bool is_interface() const             { return _access_flags.is_interface(); }
   bool is_abstract() const              { return _access_flags.is_abstract(); }
   bool is_super() const                 { return _access_flags.is_super(); }
   bool is_synthetic() const             { return _access_flags.is_synthetic(); }
   void set_is_synthetic()               { _access_flags.set_is_synthetic(); }
   bool has_finalizer() const            { return _access_flags.has_finalizer(); }
   bool has_final_method() const         { return _access_flags.has_final_method(); }
   void set_has_finalizer()              { _access_flags.set_has_finalizer(); }
   void set_has_final_method()           { _access_flags.set_has_final_method(); }
   bool is_cloneable() const             { return _access_flags.is_cloneable(); }
   void set_is_cloneable()               { _access_flags.set_is_cloneable(); }
   bool has_vanilla_constructor() const  { return _access_flags.has_vanilla_constructor(); }
   void set_has_vanilla_constructor()    { _access_flags.set_has_vanilla_constructor(); }
   bool has_miranda_methods () const     { return access_flags().has_miranda_methods(); }
   void set_has_miranda_methods()        { _access_flags.set_has_miranda_methods(); }
   // Biased locking support
   // Note: the prototype header is always set up to be at least the
   // prototype markOop. If biased locking is enabled it may further be
   // biasable and have an epoch.
   markOop prototype_header() const      { return _prototype_header; }
   // NOTE: once instances of this klass are floating around in the
   // system, this header must only be updated at a safepoint.
   // NOTE 2: currently we only ever set the prototype header to the
   // biasable prototype for instanceKlasses. There is no technical
   // reason why it could not be done for arrayKlasses aside from
   // wanting to reduce the initial scope of this optimization. There
   // are potential problems in setting the bias pattern for
   // JVM-internal oops.
   inline void set_prototype_header(markOop header);
   static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); }
   int  biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; }
   // Atomically increments biased_lock_revocation_count and returns updated value
   int atomic_incr_biased_lock_revocation_count();
   void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; }
   jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; }
   void  set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; }
   TRACE_DEFINE_KLASS_METHODS;
   // garbage collection support
   virtual void oops_do(OopClosure* cl);
   // Iff the class loader (or mirror for anonymous classes) is alive the
   // Klass is considered alive.
   // The is_alive closure passed in depends on the Garbage Collector used.
   bool is_loader_alive(BoolObjectClosure* is_alive);
   static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true);
   static void clean_subklass_tree(BoolObjectClosure* is_alive) {
     clean_weak_klass_links(is_alive, false /* clean_alive_klasses */);
   }
   // iterators
   virtual int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) = 0;
   virtual int oop_oop_iterate_v(oop obj, ExtendedOopClosure* blk) {
     return oop_oop_iterate(obj, blk);
   }
 #if INCLUDE_ALL_GCS
   // In case we don't have a specialized backward scanner use forward
   // iteration.
   virtual int oop_oop_iterate_backwards_v(oop obj, ExtendedOopClosure* blk) {
     return oop_oop_iterate_v(obj, blk);
   }
 #endif // INCLUDE_ALL_GCS
   // Iterates "blk" over all the oops in "obj" (of type "this") within "mr".
   // (I don't see why the _m should be required, but without it the Solaris
   // C++ gives warning messages about overridings of the "oop_oop_iterate"
   // defined above "hiding" this virtual function.  (DLD, 6/20/00)) */
   virtual int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) = 0;
   virtual int oop_oop_iterate_v_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) {
     return oop_oop_iterate_m(obj, blk, mr);
   }
   // Versions of the above iterators specialized to particular subtypes
   // of OopClosure, to avoid closure virtual calls.
 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)                \
   virtual int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk) {     \
     /* Default implementation reverts to general version. */                 \
     return oop_oop_iterate(obj, blk);                                        \
   }                                                                          \
                                                                              \
   /* Iterates "blk" over all the oops in "obj" (of type "this") within "mr". \
      (I don't see why the _m should be required, but without it the Solaris  \
      C++ gives warning messages about overridings of the "oop_oop_iterate"   \
      defined above "hiding" this virtual function.  (DLD, 6/20/00)) */       \
   virtual int oop_oop_iterate##nv_suffix##_m(oop obj,                        \
                                              OopClosureType* blk,            \
                                              MemRegion mr) {                 \
     return oop_oop_iterate_m(obj, blk, mr);                                  \
   }
   SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL)
   SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL)
 #if INCLUDE_ALL_GCS
 #define Klass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix)      \
   virtual int oop_oop_iterate_backwards##nv_suffix(oop obj,                  \
                                                    OopClosureType* blk) {    \
     /* Default implementation reverts to general version. */                 \
     return oop_oop_iterate_backwards_v(obj, blk);                            \
   }
   SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL)
   SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL)
 #endif // INCLUDE_ALL_GCS
   virtual void array_klasses_do(void f(Klass* k)) {}
   // Return self, except for abstract classes with exactly 1
   // implementor.  Then return the 1 concrete implementation.
   Klass *up_cast_abstract();
   // klass name
   Symbol* name() const                   { return _name; }
   void set_name(Symbol* n);
  public:
   // jvm support
   virtual jint compute_modifier_flags(TRAPS) const;
   // JVMTI support
   virtual jint jvmti_class_status() const;
   // Printing
   virtual void print_on(outputStream* st) const;
   virtual void oop_print_value_on(oop obj, outputStream* st);
   virtual void oop_print_on      (oop obj, outputStream* st);
   virtual const char* internal_name() const = 0;
   // Verification
   virtual void verify_on(outputStream* st);
   void verify() { verify_on(tty); }
 #ifndef PRODUCT
   bool verify_vtable_index(int index);
   bool verify_itable_index(int index);
 #endif
   virtual void oop_verify_on(oop obj, outputStream* st);
   static bool is_null(narrowKlass obj);
   static bool is_null(Klass* obj);
   // klass encoding for klass pointer in objects.
   static narrowKlass encode_klass_not_null(Klass* v);
   static narrowKlass encode_klass(Klass* v);
   static Klass* decode_klass_not_null(narrowKlass v);
   static Klass* decode_klass(narrowKlass v);
  private:
   // barriers used by klass_oop_store
   void klass_update_barrier_set(oop v);
   void klass_update_barrier_set_pre(oop* p, oop v);
 };
 #endif // SHARE_VM_OOPS_KLASS_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/oops/klass.hpp@2c6ef90f030a (annotated)

src/share/vm/oops/klass.hpp