rev 12851 : 8138737: Remove oop_ms_adjust_pointers and use oop_iterate instead
Reviewed-by:
rev 12852 : [mq]: 8138737-remove-oop-ms-adjust-kbarrett-rev1

   1 /*
   2  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_OOPS_KLASS_HPP
  26 #define SHARE_VM_OOPS_KLASS_HPP
  27 
  28 #include "gc/shared/specialized_oop_closures.hpp"
  29 #include "memory/iterator.hpp"
  30 #include "memory/memRegion.hpp"
  31 #include "oops/metadata.hpp"
  32 #include "oops/oop.hpp"
  33 #include "trace/traceMacros.hpp"
  34 #include "utilities/accessFlags.hpp"
  35 #include "utilities/macros.hpp"
  36 
  37 //
  38 // A Klass provides:
  39 //  1: language level class object (method dictionary etc.)
  40 //  2: provide vm dispatch behavior for the object
  41 // Both functions are combined into one C++ class.
  42 
  43 // One reason for the oop/klass dichotomy in the implementation is
  44 // that we don't want a C++ vtbl pointer in every object.  Thus,
  45 // normal oops don't have any virtual functions.  Instead, they
  46 // forward all "virtual" functions to their klass, which does have
  47 // a vtbl and does the C++ dispatch depending on the object's
  48 // actual type.  (See oop.inline.hpp for some of the forwarding code.)
  49 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"!
  50 
  51 // Forward declarations.
  52 template <class T> class Array;
  53 template <class T> class GrowableArray;
  54 class ClassLoaderData;
  55 class fieldDescriptor;
  56 class KlassSizeStats;
  57 class klassVtable;
  58 class ModuleEntry;
  59 class PackageEntry;
  60 class ParCompactionManager;
  61 class PSPromotionManager;
  62 class vtableEntry;
  63 
  64 class Klass : public Metadata {
  65   friend class VMStructs;
  66   friend class JVMCIVMStructs;
  67  protected:
  68   // note: put frequently-used fields together at start of klass structure
  69   // for better cache behavior (may not make much of a difference but sure won't hurt)
  70   enum { _primary_super_limit = 8 };
  71 
  72   // The "layout helper" is a combined descriptor of object layout.
  73   // For klasses which are neither instance nor array, the value is zero.
  74   //
  75   // For instances, layout helper is a positive number, the instance size.
  76   // This size is already passed through align_object_size and scaled to bytes.
  77   // The low order bit is set if instances of this class cannot be
  78   // allocated using the fastpath.
  79   //
  80   // For arrays, layout helper is a negative number, containing four
  81   // distinct bytes, as follows:
  82   //    MSB:[tag, hsz, ebt, log2(esz)]:LSB
  83   // where:
  84   //    tag is 0x80 if the elements are oops, 0xC0 if non-oops
  85   //    hsz is array header size in bytes (i.e., offset of first element)
  86   //    ebt is the BasicType of the elements
  87   //    esz is the element size in bytes
  88   // This packed word is arranged so as to be quickly unpacked by the
  89   // various fast paths that use the various subfields.
  90   //
  91   // The esz bits can be used directly by a SLL instruction, without masking.
  92   //
  93   // Note that the array-kind tag looks like 0x00 for instance klasses,
  94   // since their length in bytes is always less than 24Mb.
  95   //
  96   // Final note:  This comes first, immediately after C++ vtable,
  97   // because it is frequently queried.
  98   jint        _layout_helper;
  99 
 100   // The fields _super_check_offset, _secondary_super_cache, _secondary_supers
 101   // and _primary_supers all help make fast subtype checks.  See big discussion
 102   // in doc/server_compiler/checktype.txt
 103   //
 104   // Where to look to observe a supertype (it is &_secondary_super_cache for
 105   // secondary supers, else is &_primary_supers[depth()].
 106   juint       _super_check_offset;
 107 
 108   // Class name.  Instance classes: java/lang/String, etc.  Array classes: [I,
 109   // [Ljava/lang/String;, etc.  Set to zero for all other kinds of classes.
 110   Symbol*     _name;
 111 
 112   // Cache of last observed secondary supertype
 113   Klass*      _secondary_super_cache;
 114   // Array of all secondary supertypes
 115   Array<Klass*>* _secondary_supers;
 116   // Ordered list of all primary supertypes
 117   Klass*      _primary_supers[_primary_super_limit];
 118   // java/lang/Class instance mirroring this class
 119   oop       _java_mirror;
 120   // Superclass
 121   Klass*      _super;
 122   // First subclass (NULL if none); _subklass->next_sibling() is next one
 123   Klass*      _subklass;
 124   // Sibling link (or NULL); links all subklasses of a klass
 125   Klass*      _next_sibling;
 126 
 127   // All klasses loaded by a class loader are chained through these links
 128   Klass*      _next_link;
 129 
 130   // The VM's representation of the ClassLoader used to load this class.
 131   // Provide access the corresponding instance java.lang.ClassLoader.
 132   ClassLoaderData* _class_loader_data;
 133 
 134   jint        _modifier_flags;  // Processed access flags, for use by Class.getModifiers.
 135   AccessFlags _access_flags;    // Access flags. The class/interface distinction is stored here.
 136 
 137   TRACE_DEFINE_TRACE_ID_FIELD;
 138 
 139   // Biased locking implementation and statistics
 140   // (the 64-bit chunk goes first, to avoid some fragmentation)
 141   jlong    _last_biased_lock_bulk_revocation_time;
 142   markOop  _prototype_header;   // Used when biased locking is both enabled and disabled for this type
 143   jint     _biased_lock_revocation_count;
 144 
 145   // vtable length
 146   int _vtable_len;
 147 
 148   // Remembered sets support for the oops in the klasses.
 149   jbyte _modified_oops;             // Card Table Equivalent (YC/CMS support)
 150   jbyte _accumulated_modified_oops; // Mod Union Equivalent (CMS support)
 151 
 152 private:
 153   // This is an index into FileMapHeader::_classpath_entry_table[], to
 154   // associate this class with the JAR file where it's loaded from during
 155   // dump time. If a class is not loaded from the shared archive, this field is
 156   // -1.
 157   jshort _shared_class_path_index;
 158 
 159   friend class SharedClassUtil;
 160 protected:
 161 
 162   // Constructor
 163   Klass();
 164 
 165   void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw();
 166 
 167  public:
 168   enum DefaultsLookupMode { find_defaults, skip_defaults };
 169   enum OverpassLookupMode { find_overpass, skip_overpass };
 170   enum StaticLookupMode   { find_static,   skip_static };
 171   enum PrivateLookupMode  { find_private,  skip_private };
 172 
 173   bool is_klass() const volatile { return true; }
 174 
 175   // super
 176   Klass* super() const               { return _super; }
 177   void set_super(Klass* k)           { _super = k; }
 178 
 179   // initializes _super link, _primary_supers & _secondary_supers arrays
 180   void initialize_supers(Klass* k, TRAPS);
 181   void initialize_supers_impl1(Klass* k);
 182   void initialize_supers_impl2(Klass* k);
 183 
 184   // klass-specific helper for initializing _secondary_supers
 185   virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
 186 
 187   // java_super is the Java-level super type as specified by Class.getSuperClass.
 188   virtual Klass* java_super() const  { return NULL; }
 189 
 190   juint    super_check_offset() const  { return _super_check_offset; }
 191   void set_super_check_offset(juint o) { _super_check_offset = o; }
 192 
 193   Klass* secondary_super_cache() const     { return _secondary_super_cache; }
 194   void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; }
 195 
 196   Array<Klass*>* secondary_supers() const { return _secondary_supers; }
 197   void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; }
 198 
 199   // Return the element of the _super chain of the given depth.
 200   // If there is no such element, return either NULL or this.
 201   Klass* primary_super_of_depth(juint i) const {
 202     assert(i < primary_super_limit(), "oob");
 203     Klass* super = _primary_supers[i];
 204     assert(super == NULL || super->super_depth() == i, "correct display");
 205     return super;
 206   }
 207 
 208   // Can this klass be a primary super?  False for interfaces and arrays of
 209   // interfaces.  False also for arrays or classes with long super chains.
 210   bool can_be_primary_super() const {
 211     const juint secondary_offset = in_bytes(secondary_super_cache_offset());
 212     return super_check_offset() != secondary_offset;
 213   }
 214   virtual bool can_be_primary_super_slow() const;
 215 
 216   // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit].
 217   juint super_depth() const {
 218     if (!can_be_primary_super()) {
 219       return primary_super_limit();
 220     } else {
 221       juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*);
 222       assert(d < primary_super_limit(), "oob");
 223       assert(_primary_supers[d] == this, "proper init");
 224       return d;
 225     }
 226   }
 227 
 228   // store an oop into a field of a Klass
 229   void klass_oop_store(oop* p, oop v);
 230   void klass_oop_store(volatile oop* p, oop v);
 231 
 232   // java mirror
 233   oop java_mirror() const              { return _java_mirror; }
 234   void set_java_mirror(oop m) { klass_oop_store(&_java_mirror, m); }
 235 
 236   // modifier flags
 237   jint modifier_flags() const          { return _modifier_flags; }
 238   void set_modifier_flags(jint flags)  { _modifier_flags = flags; }
 239 
 240   // size helper
 241   int layout_helper() const            { return _layout_helper; }
 242   void set_layout_helper(int lh)       { _layout_helper = lh; }
 243 
 244   // Note: for instances layout_helper() may include padding.
 245   // Use InstanceKlass::contains_field_offset to classify field offsets.
 246 
 247   // sub/superklass links
 248   Klass* subklass() const              { return _subklass; }
 249   Klass* next_sibling() const          { return _next_sibling; }
 250   InstanceKlass* superklass() const;
 251   void append_to_sibling_list();           // add newly created receiver to superklass' subklass list
 252 
 253   void set_next_link(Klass* k) { _next_link = k; }
 254   Klass* next_link() const { return _next_link; }   // The next klass defined by the class loader.
 255 
 256   // class loader data
 257   ClassLoaderData* class_loader_data() const               { return _class_loader_data; }
 258   void set_class_loader_data(ClassLoaderData* loader_data) {  _class_loader_data = loader_data; }
 259 
 260   // The Klasses are not placed in the Heap, so the Card Table or
 261   // the Mod Union Table can't be used to mark when klasses have modified oops.
 262   // The CT and MUT bits saves this information for the individual Klasses.
 263   void record_modified_oops()            { _modified_oops = 1; }
 264   void clear_modified_oops()             { _modified_oops = 0; }
 265   bool has_modified_oops()               { return _modified_oops == 1; }
 266 
 267   void accumulate_modified_oops()        { if (has_modified_oops()) _accumulated_modified_oops = 1; }
 268   void clear_accumulated_modified_oops() { _accumulated_modified_oops = 0; }
 269   bool has_accumulated_modified_oops()   { return _accumulated_modified_oops == 1; }
 270 
 271   int shared_classpath_index() const   {
 272     return _shared_class_path_index;
 273   };
 274 
 275   void set_shared_classpath_index(int index) {
 276     _shared_class_path_index = index;
 277   };
 278 
 279   // Obtain the module or package for this class
 280   virtual ModuleEntry* module() const = 0;
 281   virtual PackageEntry* package() const = 0;
 282 
 283  protected:                                // internal accessors
 284   void     set_subklass(Klass* s);
 285   void     set_next_sibling(Klass* s);
 286 
 287  public:
 288 
 289   // Compiler support
 290   static ByteSize super_offset()                 { return in_ByteSize(offset_of(Klass, _super)); }
 291   static ByteSize super_check_offset_offset()    { return in_ByteSize(offset_of(Klass, _super_check_offset)); }
 292   static ByteSize primary_supers_offset()        { return in_ByteSize(offset_of(Klass, _primary_supers)); }
 293   static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); }
 294   static ByteSize secondary_supers_offset()      { return in_ByteSize(offset_of(Klass, _secondary_supers)); }
 295   static ByteSize java_mirror_offset()           { return in_ByteSize(offset_of(Klass, _java_mirror)); }
 296   static ByteSize modifier_flags_offset()        { return in_ByteSize(offset_of(Klass, _modifier_flags)); }
 297   static ByteSize layout_helper_offset()         { return in_ByteSize(offset_of(Klass, _layout_helper)); }
 298   static ByteSize access_flags_offset()          { return in_ByteSize(offset_of(Klass, _access_flags)); }
 299 
 300   // Unpacking layout_helper:
 301   enum {
 302     _lh_neutral_value           = 0,  // neutral non-array non-instance value
 303     _lh_instance_slow_path_bit  = 0x01,
 304     _lh_log2_element_size_shift = BitsPerByte*0,
 305     _lh_log2_element_size_mask  = BitsPerLong-1,
 306     _lh_element_type_shift      = BitsPerByte*1,
 307     _lh_element_type_mask       = right_n_bits(BitsPerByte),  // shifted mask
 308     _lh_header_size_shift       = BitsPerByte*2,
 309     _lh_header_size_mask        = right_n_bits(BitsPerByte),  // shifted mask
 310     _lh_array_tag_bits          = 2,
 311     _lh_array_tag_shift         = BitsPerInt - _lh_array_tag_bits,
 312     _lh_array_tag_obj_value     = ~0x01   // 0x80000000 >> 30
 313   };
 314 
 315   static const unsigned int _lh_array_tag_type_value = 0Xffffffff; // ~0x00,  // 0xC0000000 >> 30
 316 
 317   static int layout_helper_size_in_bytes(jint lh) {
 318     assert(lh > (jint)_lh_neutral_value, "must be instance");
 319     return (int) lh & ~_lh_instance_slow_path_bit;
 320   }
 321   static bool layout_helper_needs_slow_path(jint lh) {
 322     assert(lh > (jint)_lh_neutral_value, "must be instance");
 323     return (lh & _lh_instance_slow_path_bit) != 0;
 324   }
 325   static bool layout_helper_is_instance(jint lh) {
 326     return (jint)lh > (jint)_lh_neutral_value;
 327   }
 328   static bool layout_helper_is_array(jint lh) {
 329     return (jint)lh < (jint)_lh_neutral_value;
 330   }
 331   static bool layout_helper_is_typeArray(jint lh) {
 332     // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift);
 333     return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift);
 334   }
 335   static bool layout_helper_is_objArray(jint lh) {
 336     // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift);
 337     return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift);
 338   }
 339   static int layout_helper_header_size(jint lh) {
 340     assert(lh < (jint)_lh_neutral_value, "must be array");
 341     int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask;
 342     assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity");
 343     return hsize;
 344   }
 345   static BasicType layout_helper_element_type(jint lh) {
 346     assert(lh < (jint)_lh_neutral_value, "must be array");
 347     int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask;
 348     assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity");
 349     return (BasicType) btvalue;
 350   }
 351 
 352   // Want a pattern to quickly diff against layout header in register
 353   // find something less clever!
 354   static int layout_helper_boolean_diffbit() {
 355     jint zlh = array_layout_helper(T_BOOLEAN);
 356     jint blh = array_layout_helper(T_BYTE);
 357     assert(zlh != blh, "array layout helpers must differ");
 358     int diffbit = 1;
 359     while ((diffbit & (zlh ^ blh)) == 0 && (diffbit & zlh) == 0) {
 360       diffbit <<= 1;
 361       assert(diffbit != 0, "make sure T_BOOLEAN has a different bit than T_BYTE");
 362     }
 363     return diffbit;
 364   }
 365 
 366   static int layout_helper_log2_element_size(jint lh) {
 367     assert(lh < (jint)_lh_neutral_value, "must be array");
 368     int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask;
 369     assert(l2esz <= LogBitsPerLong,
 370            "sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh);
 371     return l2esz;
 372   }
 373   static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) {
 374     return (tag        << _lh_array_tag_shift)
 375       |    (hsize      << _lh_header_size_shift)
 376       |    ((int)etype << _lh_element_type_shift)
 377       |    (log2_esize << _lh_log2_element_size_shift);
 378   }
 379   static jint instance_layout_helper(jint size, bool slow_path_flag) {
 380     return (size << LogBytesPerWord)
 381       |    (slow_path_flag ? _lh_instance_slow_path_bit : 0);
 382   }
 383   static int layout_helper_to_size_helper(jint lh) {
 384     assert(lh > (jint)_lh_neutral_value, "must be instance");
 385     // Note that the following expression discards _lh_instance_slow_path_bit.
 386     return lh >> LogBytesPerWord;
 387   }
 388   // Out-of-line version computes everything based on the etype:
 389   static jint array_layout_helper(BasicType etype);
 390 
 391   // What is the maximum number of primary superclasses any klass can have?
 392 #ifdef PRODUCT
 393   static juint primary_super_limit()         { return _primary_super_limit; }
 394 #else
 395   static juint primary_super_limit() {
 396     assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob");
 397     return FastSuperclassLimit;
 398   }
 399 #endif
 400 
 401   // vtables
 402   klassVtable* vtable() const;
 403   int vtable_length() const { return _vtable_len; }
 404 
 405   // subclass check
 406   bool is_subclass_of(const Klass* k) const;
 407   // subtype check: true if is_subclass_of, or if k is interface and receiver implements it
 408   bool is_subtype_of(Klass* k) const {
 409     juint    off = k->super_check_offset();
 410     Klass* sup = *(Klass**)( (address)this + off );
 411     const juint secondary_offset = in_bytes(secondary_super_cache_offset());
 412     if (sup == k) {
 413       return true;
 414     } else if (off != secondary_offset) {
 415       return false;
 416     } else {
 417       return search_secondary_supers(k);
 418     }
 419   }
 420   bool search_secondary_supers(Klass* k) const;
 421 
 422   // Find LCA in class hierarchy
 423   Klass *LCA( Klass *k );
 424 
 425   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 426   // if not, throw either an Error or an Exception.
 427   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 428 
 429   // array copying
 430   virtual void  copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
 431 
 432   // tells if the class should be initialized
 433   virtual bool should_be_initialized() const    { return false; }
 434   // initializes the klass
 435   virtual void initialize(TRAPS);
 436   // lookup operation for MethodLookupCache
 437   friend class MethodLookupCache;
 438   virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const;
 439   virtual Method* uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const;
 440  public:
 441   Method* lookup_method(const Symbol* name, const Symbol* signature) const {
 442     return uncached_lookup_method(name, signature, find_overpass);
 443   }
 444 
 445   // array class with specific rank
 446   Klass* array_klass(int rank, TRAPS)         {  return array_klass_impl(false, rank, THREAD); }
 447 
 448   // array class with this klass as element type
 449   Klass* array_klass(TRAPS)                   {  return array_klass_impl(false, THREAD); }
 450 
 451   // These will return NULL instead of allocating on the heap:
 452   // NB: these can block for a mutex, like other functions with TRAPS arg.
 453   Klass* array_klass_or_null(int rank);
 454   Klass* array_klass_or_null();
 455 
 456   virtual oop protection_domain() const = 0;
 457 
 458   oop class_loader() const;
 459 
 460   virtual oop klass_holder() const      { return class_loader(); }
 461 
 462  protected:
 463   virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS);
 464   virtual Klass* array_klass_impl(bool or_null, TRAPS);
 465 
 466   void set_vtable_length(int len) { _vtable_len= len; }
 467 
 468   vtableEntry* start_of_vtable() const;
 469  public:
 470   Method* method_at_vtable(int index);
 471 
 472   static ByteSize vtable_start_offset();
 473   static ByteSize vtable_length_offset() {
 474     return byte_offset_of(Klass, _vtable_len);
 475   }
 476 
 477   // CDS support - remove and restore oops from metadata. Oops are not shared.
 478   virtual void remove_unshareable_info();
 479   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
 480 
 481  protected:
 482   // computes the subtype relationship
 483   virtual bool compute_is_subtype_of(Klass* k);
 484  public:
 485   // subclass accessor (here for convenience; undefined for non-klass objects)
 486   virtual bool is_leaf_class() const { fatal("not a class"); return false; }
 487  public:
 488   // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP
 489   // These functions describe behavior for the oop not the KLASS.
 490 
 491   // actual oop size of obj in memory
 492   virtual int oop_size(oop obj) const = 0;
 493 
 494   // Size of klass in word size.
 495   virtual int size() const = 0;
 496 #if INCLUDE_SERVICES
 497   virtual void collect_statistics(KlassSizeStats *sz) const;
 498 #endif
 499 
 500   // Returns the Java name for a class (Resource allocated)
 501   // For arrays, this returns the name of the element with a leading '['.
 502   // For classes, this returns the name with the package separators
 503   //     turned into '.'s.
 504   const char* external_name() const;
 505   // Returns the name for a class (Resource allocated) as the class
 506   // would appear in a signature.
 507   // For arrays, this returns the name of the element with a leading '['.
 508   // For classes, this returns the name with a leading 'L' and a trailing ';'
 509   //     and the package separators as '/'.
 510   virtual const char* signature_name() const;
 511 
 512   // type testing operations
 513 #ifdef ASSERT
 514  protected:
 515   virtual bool is_instance_klass_slow()     const { return false; }
 516   virtual bool is_array_klass_slow()        const { return false; }
 517   virtual bool is_objArray_klass_slow()     const { return false; }
 518   virtual bool is_typeArray_klass_slow()    const { return false; }
 519 #endif // ASSERT
 520  public:
 521 
 522   // Fast non-virtual versions
 523   #ifndef ASSERT
 524   #define assert_same_query(xval, xcheck) xval
 525   #else
 526  private:
 527   static bool assert_same_query(bool xval, bool xslow) {
 528     assert(xval == xslow, "slow and fast queries agree");
 529     return xval;
 530   }
 531  public:
 532   #endif
 533   inline  bool is_instance_klass()            const { return assert_same_query(
 534                                                       layout_helper_is_instance(layout_helper()),
 535                                                       is_instance_klass_slow()); }
 536   inline  bool is_array_klass()               const { return assert_same_query(
 537                                                     layout_helper_is_array(layout_helper()),
 538                                                     is_array_klass_slow()); }
 539   inline  bool is_objArray_klass()            const { return assert_same_query(
 540                                                     layout_helper_is_objArray(layout_helper()),
 541                                                     is_objArray_klass_slow()); }
 542   inline  bool is_typeArray_klass()           const { return assert_same_query(
 543                                                     layout_helper_is_typeArray(layout_helper()),
 544                                                     is_typeArray_klass_slow()); }
 545   #undef assert_same_query
 546 
 547   // Access flags
 548   AccessFlags access_flags() const         { return _access_flags;  }
 549   void set_access_flags(AccessFlags flags) { _access_flags = flags; }
 550 
 551   bool is_public() const                { return _access_flags.is_public(); }
 552   bool is_final() const                 { return _access_flags.is_final(); }
 553   bool is_interface() const             { return _access_flags.is_interface(); }
 554   bool is_abstract() const              { return _access_flags.is_abstract(); }
 555   bool is_super() const                 { return _access_flags.is_super(); }
 556   bool is_synthetic() const             { return _access_flags.is_synthetic(); }
 557   void set_is_synthetic()               { _access_flags.set_is_synthetic(); }
 558   bool has_finalizer() const            { return _access_flags.has_finalizer(); }
 559   bool has_final_method() const         { return _access_flags.has_final_method(); }
 560   void set_has_finalizer()              { _access_flags.set_has_finalizer(); }
 561   void set_has_final_method()           { _access_flags.set_has_final_method(); }
 562   bool has_vanilla_constructor() const  { return _access_flags.has_vanilla_constructor(); }
 563   void set_has_vanilla_constructor()    { _access_flags.set_has_vanilla_constructor(); }
 564   bool has_miranda_methods () const     { return access_flags().has_miranda_methods(); }
 565   void set_has_miranda_methods()        { _access_flags.set_has_miranda_methods(); }
 566 
 567   bool is_cloneable() const;
 568   void set_is_cloneable();
 569 
 570   // Biased locking support
 571   // Note: the prototype header is always set up to be at least the
 572   // prototype markOop. If biased locking is enabled it may further be
 573   // biasable and have an epoch.
 574   markOop prototype_header() const      { return _prototype_header; }
 575   // NOTE: once instances of this klass are floating around in the
 576   // system, this header must only be updated at a safepoint.
 577   // NOTE 2: currently we only ever set the prototype header to the
 578   // biasable prototype for instanceKlasses. There is no technical
 579   // reason why it could not be done for arrayKlasses aside from
 580   // wanting to reduce the initial scope of this optimization. There
 581   // are potential problems in setting the bias pattern for
 582   // JVM-internal oops.
 583   inline void set_prototype_header(markOop header);
 584   static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); }
 585 
 586   int  biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; }
 587   // Atomically increments biased_lock_revocation_count and returns updated value
 588   int atomic_incr_biased_lock_revocation_count();
 589   void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; }
 590   jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; }
 591   void  set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; }
 592 
 593   TRACE_DEFINE_TRACE_ID_METHODS;
 594 
 595   // garbage collection support
 596   void oops_do(OopClosure* cl);
 597 
 598   // Iff the class loader (or mirror for anonymous classes) is alive the
 599   // Klass is considered alive.
 600   // The is_alive closure passed in depends on the Garbage Collector used.
 601   bool is_loader_alive(BoolObjectClosure* is_alive);
 602 
 603   static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true);
 604   static void clean_subklass_tree(BoolObjectClosure* is_alive) {
 605     clean_weak_klass_links(is_alive, false /* clean_alive_klasses */);
 606   }
 607 
 608   // GC specific object visitors
 609   //


 610 #if INCLUDE_ALL_GCS
 611   // Parallel Scavenge
 612   virtual void oop_ps_push_contents(  oop obj, PSPromotionManager* pm)   = 0;
 613   // Parallel Compact
 614   virtual void oop_pc_follow_contents(oop obj, ParCompactionManager* cm) = 0;
 615   virtual void oop_pc_update_pointers(oop obj, ParCompactionManager* cm) = 0;
 616 #endif
 617 
 618   // Iterators specialized to particular subtypes
 619   // of ExtendedOopClosure, to avoid closure virtual calls.
 620 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)                                           \
 621   virtual void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) = 0;                        \
 622   /* Iterates "closure" over all the oops in "obj" (of type "this") within "mr". */                     \
 623   virtual void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) = 0;
 624 
 625   ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL)
 626   ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL)
 627 
 628 #if INCLUDE_ALL_GCS
 629 #define Klass_OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix)                     \
 630   virtual void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) = 0;
 631 
 632   ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
 633   ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
 634 #endif // INCLUDE_ALL_GCS
 635 
 636   virtual void array_klasses_do(void f(Klass* k)) {}
 637 
 638   // Return self, except for abstract classes with exactly 1
 639   // implementor.  Then return the 1 concrete implementation.
 640   Klass *up_cast_abstract();
 641 
 642   // klass name
 643   Symbol* name() const                   { return _name; }
 644   void set_name(Symbol* n);
 645 
 646  public:
 647   // jvm support
 648   virtual jint compute_modifier_flags(TRAPS) const;
 649 
 650   // JVMTI support
 651   virtual jint jvmti_class_status() const;
 652 
 653   // Printing
 654   virtual void print_on(outputStream* st) const;
 655 
 656   virtual void oop_print_value_on(oop obj, outputStream* st);
 657   virtual void oop_print_on      (oop obj, outputStream* st);
 658 
 659   virtual const char* internal_name() const = 0;
 660 
 661   // Verification
 662   virtual void verify_on(outputStream* st);
 663   void verify() { verify_on(tty); }
 664 
 665 #ifndef PRODUCT
 666   bool verify_vtable_index(int index);
 667   bool verify_itable_index(int index);
 668 #endif
 669 
 670   virtual void oop_verify_on(oop obj, outputStream* st);
 671 
 672   static bool is_null(narrowKlass obj);
 673   static bool is_null(Klass* obj);
 674 
 675   // klass encoding for klass pointer in objects.
 676   static narrowKlass encode_klass_not_null(Klass* v);
 677   static narrowKlass encode_klass(Klass* v);
 678 
 679   static Klass* decode_klass_not_null(narrowKlass v);
 680   static Klass* decode_klass(narrowKlass v);
 681 
 682  private:
 683   // barriers used by klass_oop_store
 684   void klass_update_barrier_set(oop v);
 685   void klass_update_barrier_set_pre(oop* p, oop v);
 686 };
 687 
 688 // Helper to convert the oop iterate macro suffixes into bool values that can be used by template functions.
 689 #define nvs_nv_to_bool true
 690 #define nvs_v_to_bool  false
 691 #define nvs_to_bool(nv_suffix) nvs##nv_suffix##_to_bool
 692 
 693 // Oop iteration macros for declarations.
 694 // Used to generate declarations in the *Klass header files.
 695 
 696 #define OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)                                    \
 697   void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure);                        \
 698   void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr);
 699 
 700 #if INCLUDE_ALL_GCS
 701 #define OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix)               \
 702   void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure);
 703 #endif // INCLUDE_ALL_GCS
 704 
 705 
 706 // Oop iteration macros for definitions.
 707 // Used to generate definitions in the *Klass.inline.hpp files.
 708 
 709 #define OOP_OOP_ITERATE_DEFN(KlassType, OopClosureType, nv_suffix)              \
 710 void KlassType::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) {  \
 711   oop_oop_iterate<nvs_to_bool(nv_suffix)>(obj, closure);                        \
 712 }
 713 
 714 #if INCLUDE_ALL_GCS
 715 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix)              \
 716 void KlassType::oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) {  \
 717   oop_oop_iterate_reverse<nvs_to_bool(nv_suffix)>(obj, closure);                          \
 718 }
 719 #else
 720 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix)
 721 #endif
 722 
 723 #define OOP_OOP_ITERATE_DEFN_BOUNDED(KlassType, OopClosureType, nv_suffix)                            \
 724 void KlassType::oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) {  \
 725   oop_oop_iterate_bounded<nvs_to_bool(nv_suffix)>(obj, closure, mr);                                  \
 726 }
 727 
 728 #endif // SHARE_VM_OOPS_KLASS_HPP
--- EOF ---