1 /* 2 * Copyright (c) 1997, 2015, 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 klassVtable; 56 class ParCompactionManager; 57 class PSPromotionManager; 58 class KlassSizeStats; 59 class fieldDescriptor; 60 61 class Klass : public Metadata { 62 friend class VMStructs; 63 protected: 64 // note: put frequently-used fields together at start of klass structure 65 // for better cache behavior (may not make much of a difference but sure won't hurt) 66 enum { _primary_super_limit = 8 }; 67 68 // The "layout helper" is a combined descriptor of object layout. 69 // For klasses which are neither instance nor array, the value is zero. 70 // 71 // For instances, layout helper is a positive number, the instance size. 72 // This size is already passed through align_object_size and scaled to bytes. 73 // The low order bit is set if instances of this class cannot be 74 // allocated using the fastpath. 75 // 76 // For arrays, layout helper is a negative number, containing four 77 // distinct bytes, as follows: 78 // MSB:[tag, hsz, ebt, log2(esz)]:LSB 79 // where: 80 // tag is 0x80 if the elements are oops, 0xC0 if non-oops 81 // hsz is array header size in bytes (i.e., offset of first element) 82 // ebt is the BasicType of the elements 83 // esz is the element size in bytes 84 // This packed word is arranged so as to be quickly unpacked by the 85 // various fast paths that use the various subfields. 86 // 87 // The esz bits can be used directly by a SLL instruction, without masking. 88 // 89 // Note that the array-kind tag looks like 0x00 for instance klasses, 90 // since their length in bytes is always less than 24Mb. 91 // 92 // Final note: This comes first, immediately after C++ vtable, 93 // because it is frequently queried. 94 jint _layout_helper; 95 96 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers 97 // and _primary_supers all help make fast subtype checks. See big discussion 98 // in doc/server_compiler/checktype.txt 99 // 100 // Where to look to observe a supertype (it is &_secondary_super_cache for 101 // secondary supers, else is &_primary_supers[depth()]. 102 juint _super_check_offset; 103 104 // Class name. Instance classes: java/lang/String, etc. Array classes: [I, 105 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes. 106 Symbol* _name; 107 108 // Cache of last observed secondary supertype 109 Klass* _secondary_super_cache; 110 // Array of all secondary supertypes 111 Array<Klass*>* _secondary_supers; 112 // Ordered list of all primary supertypes 113 Klass* _primary_supers[_primary_super_limit]; 114 // java/lang/Class instance mirroring this class 115 oop _java_mirror; 116 // Superclass 117 Klass* _super; 118 // First subclass (NULL if none); _subklass->next_sibling() is next one 119 Klass* _subklass; 120 // Sibling link (or NULL); links all subklasses of a klass 121 Klass* _next_sibling; 122 123 // All klasses loaded by a class loader are chained through these links 124 Klass* _next_link; 125 126 // The VM's representation of the ClassLoader used to load this class. 127 // Provide access the corresponding instance java.lang.ClassLoader. 128 ClassLoaderData* _class_loader_data; 129 130 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers. 131 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here. 132 133 // Biased locking implementation and statistics 134 // (the 64-bit chunk goes first, to avoid some fragmentation) 135 jlong _last_biased_lock_bulk_revocation_time; 136 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type 137 jint _biased_lock_revocation_count; 138 139 TRACE_DEFINE_KLASS_TRACE_ID; 140 141 // Remembered sets support for the oops in the klasses. 142 jbyte _modified_oops; // Card Table Equivalent (YC/CMS support) 143 jbyte _accumulated_modified_oops; // Mod Union Equivalent (CMS support) 144 145 private: 146 // This is an index into FileMapHeader::_classpath_entry_table[], to 147 // associate this class with the JAR file where it's loaded from during 148 // dump time. If a class is not loaded from the shared archive, this field is 149 // -1. 150 jshort _shared_class_path_index; 151 152 friend class SharedClassUtil; 153 protected: 154 155 // Constructor 156 Klass(); 157 158 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw(); 159 160 public: 161 enum DefaultsLookupMode { find_defaults, skip_defaults }; 162 enum OverpassLookupMode { find_overpass, skip_overpass }; 163 enum StaticLookupMode { find_static, skip_static }; 164 165 bool is_klass() const volatile { return true; } 166 167 // super 168 Klass* super() const { return _super; } 169 void set_super(Klass* k) { _super = k; } 170 171 // initializes _super link, _primary_supers & _secondary_supers arrays 172 void initialize_supers(Klass* k, TRAPS); 173 void initialize_supers_impl1(Klass* k); 174 void initialize_supers_impl2(Klass* k); 175 176 // klass-specific helper for initializing _secondary_supers 177 virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots); 178 179 // java_super is the Java-level super type as specified by Class.getSuperClass. 180 virtual Klass* java_super() const { return NULL; } 181 182 juint super_check_offset() const { return _super_check_offset; } 183 void set_super_check_offset(juint o) { _super_check_offset = o; } 184 185 Klass* secondary_super_cache() const { return _secondary_super_cache; } 186 void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; } 187 188 Array<Klass*>* secondary_supers() const { return _secondary_supers; } 189 void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; } 190 191 // Return the element of the _super chain of the given depth. 192 // If there is no such element, return either NULL or this. 193 Klass* primary_super_of_depth(juint i) const { 194 assert(i < primary_super_limit(), "oob"); 195 Klass* super = _primary_supers[i]; 196 assert(super == NULL || super->super_depth() == i, "correct display"); 197 return super; 198 } 199 200 // Can this klass be a primary super? False for interfaces and arrays of 201 // interfaces. False also for arrays or classes with long super chains. 202 bool can_be_primary_super() const { 203 const juint secondary_offset = in_bytes(secondary_super_cache_offset()); 204 return super_check_offset() != secondary_offset; 205 } 206 virtual bool can_be_primary_super_slow() const; 207 208 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit]. 209 juint super_depth() const { 210 if (!can_be_primary_super()) { 211 return primary_super_limit(); 212 } else { 213 juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*); 214 assert(d < primary_super_limit(), "oob"); 215 assert(_primary_supers[d] == this, "proper init"); 216 return d; 217 } 218 } 219 220 // store an oop into a field of a Klass 221 void klass_oop_store(oop* p, oop v); 222 void klass_oop_store(volatile oop* p, oop v); 223 224 // java mirror 225 oop java_mirror() const { return _java_mirror; } 226 void set_java_mirror(oop m) { klass_oop_store(&_java_mirror, m); } 227 228 // modifier flags 229 jint modifier_flags() const { return _modifier_flags; } 230 void set_modifier_flags(jint flags) { _modifier_flags = flags; } 231 232 // size helper 233 int layout_helper() const { return _layout_helper; } 234 void set_layout_helper(int lh) { _layout_helper = lh; } 235 236 // Note: for instances layout_helper() may include padding. 237 // Use InstanceKlass::contains_field_offset to classify field offsets. 238 239 // sub/superklass links 240 Klass* subklass() const { return _subklass; } 241 Klass* next_sibling() const { return _next_sibling; } 242 InstanceKlass* superklass() const; 243 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list 244 245 void set_next_link(Klass* k) { _next_link = k; } 246 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader. 247 248 // class loader data 249 ClassLoaderData* class_loader_data() const { return _class_loader_data; } 250 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; } 251 252 // The Klasses are not placed in the Heap, so the Card Table or 253 // the Mod Union Table can't be used to mark when klasses have modified oops. 254 // The CT and MUT bits saves this information for the individual Klasses. 255 void record_modified_oops() { _modified_oops = 1; } 256 void clear_modified_oops() { _modified_oops = 0; } 257 bool has_modified_oops() { return _modified_oops == 1; } 258 259 void accumulate_modified_oops() { if (has_modified_oops()) _accumulated_modified_oops = 1; } 260 void clear_accumulated_modified_oops() { _accumulated_modified_oops = 0; } 261 bool has_accumulated_modified_oops() { return _accumulated_modified_oops == 1; } 262 263 int shared_classpath_index() const { 264 return _shared_class_path_index; 265 }; 266 267 void set_shared_classpath_index(int index) { 268 _shared_class_path_index = index; 269 }; 270 271 272 protected: // internal accessors 273 void set_subklass(Klass* s); 274 void set_next_sibling(Klass* s); 275 276 public: 277 278 // Compiler support 279 static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); } 280 static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); } 281 static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); } 282 static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); } 283 static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); } 284 static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); } 285 static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); } 286 static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); } 287 static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); } 288 289 // Unpacking layout_helper: 290 enum { 291 _lh_neutral_value = 0, // neutral non-array non-instance value 292 _lh_instance_slow_path_bit = 0x01, 293 _lh_log2_element_size_shift = BitsPerByte*0, 294 _lh_log2_element_size_mask = BitsPerLong-1, 295 _lh_element_type_shift = BitsPerByte*1, 296 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask 297 _lh_header_size_shift = BitsPerByte*2, 298 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask 299 _lh_array_tag_bits = 2, 300 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits, 301 _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30 302 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30 303 }; 304 305 static int layout_helper_size_in_bytes(jint lh) { 306 assert(lh > (jint)_lh_neutral_value, "must be instance"); 307 return (int) lh & ~_lh_instance_slow_path_bit; 308 } 309 static bool layout_helper_needs_slow_path(jint lh) { 310 assert(lh > (jint)_lh_neutral_value, "must be instance"); 311 return (lh & _lh_instance_slow_path_bit) != 0; 312 } 313 static bool layout_helper_is_instance(jint lh) { 314 return (jint)lh > (jint)_lh_neutral_value; 315 } 316 static bool layout_helper_is_array(jint lh) { 317 return (jint)lh < (jint)_lh_neutral_value; 318 } 319 static bool layout_helper_is_typeArray(jint lh) { 320 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift); 321 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift); 322 } 323 static bool layout_helper_is_objArray(jint lh) { 324 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift); 325 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift); 326 } 327 static int layout_helper_header_size(jint lh) { 328 assert(lh < (jint)_lh_neutral_value, "must be array"); 329 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask; 330 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity"); 331 return hsize; 332 } 333 static BasicType layout_helper_element_type(jint lh) { 334 assert(lh < (jint)_lh_neutral_value, "must be array"); 335 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask; 336 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity"); 337 return (BasicType) btvalue; 338 } 339 static int layout_helper_log2_element_size(jint lh) { 340 assert(lh < (jint)_lh_neutral_value, "must be array"); 341 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask; 342 assert(l2esz <= LogBitsPerLong, 343 err_msg("sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh)); 344 return l2esz; 345 } 346 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) { 347 return (tag << _lh_array_tag_shift) 348 | (hsize << _lh_header_size_shift) 349 | ((int)etype << _lh_element_type_shift) 350 | (log2_esize << _lh_log2_element_size_shift); 351 } 352 static jint instance_layout_helper(jint size, bool slow_path_flag) { 353 return (size << LogHeapWordSize) 354 | (slow_path_flag ? _lh_instance_slow_path_bit : 0); 355 } 356 static int layout_helper_to_size_helper(jint lh) { 357 assert(lh > (jint)_lh_neutral_value, "must be instance"); 358 // Note that the following expression discards _lh_instance_slow_path_bit. 359 return lh >> LogHeapWordSize; 360 } 361 // Out-of-line version computes everything based on the etype: 362 static jint array_layout_helper(BasicType etype); 363 364 // What is the maximum number of primary superclasses any klass can have? 365 #ifdef PRODUCT 366 static juint primary_super_limit() { return _primary_super_limit; } 367 #else 368 static juint primary_super_limit() { 369 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob"); 370 return FastSuperclassLimit; 371 } 372 #endif 373 374 // vtables 375 virtual klassVtable* vtable() const { return NULL; } 376 virtual int vtable_length() const { return 0; } 377 378 // subclass check 379 bool is_subclass_of(const Klass* k) const; 380 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it 381 bool is_subtype_of(Klass* k) const { 382 juint off = k->super_check_offset(); 383 Klass* sup = *(Klass**)( (address)this + off ); 384 const juint secondary_offset = in_bytes(secondary_super_cache_offset()); 385 if (sup == k) { 386 return true; 387 } else if (off != secondary_offset) { 388 return false; 389 } else { 390 return search_secondary_supers(k); 391 } 392 } 393 bool search_secondary_supers(Klass* k) const; 394 395 // Find LCA in class hierarchy 396 Klass *LCA( Klass *k ); 397 398 // Check whether reflection/jni/jvm code is allowed to instantiate this class; 399 // if not, throw either an Error or an Exception. 400 virtual void check_valid_for_instantiation(bool throwError, TRAPS); 401 402 // array copying 403 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS); 404 405 // tells if the class should be initialized 406 virtual bool should_be_initialized() const { return false; } 407 // initializes the klass 408 virtual void initialize(TRAPS); 409 // lookup operation for MethodLookupCache 410 friend class MethodLookupCache; 411 virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const; 412 virtual Method* uncached_lookup_method(Symbol* name, Symbol* signature, OverpassLookupMode overpass_mode) const; 413 public: 414 Method* lookup_method(Symbol* name, Symbol* signature) const { 415 return uncached_lookup_method(name, signature, find_overpass); 416 } 417 418 // array class with specific rank 419 Klass* array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); } 420 421 // array class with this klass as element type 422 Klass* array_klass(TRAPS) { return array_klass_impl(false, THREAD); } 423 424 // These will return NULL instead of allocating on the heap: 425 // NB: these can block for a mutex, like other functions with TRAPS arg. 426 Klass* array_klass_or_null(int rank); 427 Klass* array_klass_or_null(); 428 429 virtual oop protection_domain() const = 0; 430 431 oop class_loader() const; 432 433 virtual oop klass_holder() const { return class_loader(); } 434 435 protected: 436 virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS); 437 virtual Klass* array_klass_impl(bool or_null, TRAPS); 438 439 public: 440 // CDS support - remove and restore oops from metadata. Oops are not shared. 441 virtual void remove_unshareable_info(); 442 virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS); 443 444 protected: 445 // computes the subtype relationship 446 virtual bool compute_is_subtype_of(Klass* k); 447 public: 448 // subclass accessor (here for convenience; undefined for non-klass objects) 449 virtual bool is_leaf_class() const { fatal("not a class"); return false; } 450 public: 451 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP 452 // These functions describe behavior for the oop not the KLASS. 453 454 // actual oop size of obj in memory 455 virtual int oop_size(oop obj) const = 0; 456 457 // Size of klass in word size. 458 virtual int size() const = 0; 459 #if INCLUDE_SERVICES 460 virtual void collect_statistics(KlassSizeStats *sz) const; 461 #endif 462 463 // Returns the Java name for a class (Resource allocated) 464 // For arrays, this returns the name of the element with a leading '['. 465 // For classes, this returns the name with the package separators 466 // turned into '.'s. 467 const char* external_name() const; 468 // Returns the name for a class (Resource allocated) as the class 469 // would appear in a signature. 470 // For arrays, this returns the name of the element with a leading '['. 471 // For classes, this returns the name with a leading 'L' and a trailing ';' 472 // and the package separators as '/'. 473 virtual const char* signature_name() const; 474 475 // type testing operations 476 protected: 477 virtual bool oop_is_instance_slow() const { return false; } 478 virtual bool oop_is_array_slow() const { return false; } 479 virtual bool oop_is_objArray_slow() const { return false; } 480 virtual bool oop_is_typeArray_slow() const { return false; } 481 public: 482 virtual bool oop_is_instanceClassLoader() const { return false; } 483 virtual bool oop_is_instanceMirror() const { return false; } 484 virtual bool oop_is_instanceRef() const { return false; } 485 486 // Fast non-virtual versions 487 #ifndef ASSERT 488 #define assert_same_query(xval, xcheck) xval 489 #else 490 private: 491 static bool assert_same_query(bool xval, bool xslow) { 492 assert(xval == xslow, "slow and fast queries agree"); 493 return xval; 494 } 495 public: 496 #endif 497 inline bool oop_is_instance() const { return assert_same_query( 498 layout_helper_is_instance(layout_helper()), 499 oop_is_instance_slow()); } 500 inline bool oop_is_array() const { return assert_same_query( 501 layout_helper_is_array(layout_helper()), 502 oop_is_array_slow()); } 503 inline bool oop_is_objArray() const { return assert_same_query( 504 layout_helper_is_objArray(layout_helper()), 505 oop_is_objArray_slow()); } 506 inline bool oop_is_typeArray() const { return assert_same_query( 507 layout_helper_is_typeArray(layout_helper()), 508 oop_is_typeArray_slow()); } 509 #undef assert_same_query 510 511 // Access flags 512 AccessFlags access_flags() const { return _access_flags; } 513 void set_access_flags(AccessFlags flags) { _access_flags = flags; } 514 515 bool is_public() const { return _access_flags.is_public(); } 516 bool is_final() const { return _access_flags.is_final(); } 517 bool is_interface() const { return _access_flags.is_interface(); } 518 bool is_abstract() const { return _access_flags.is_abstract(); } 519 bool is_super() const { return _access_flags.is_super(); } 520 bool is_synthetic() const { return _access_flags.is_synthetic(); } 521 void set_is_synthetic() { _access_flags.set_is_synthetic(); } 522 bool has_finalizer() const { return _access_flags.has_finalizer(); } 523 bool has_final_method() const { return _access_flags.has_final_method(); } 524 void set_has_finalizer() { _access_flags.set_has_finalizer(); } 525 void set_has_final_method() { _access_flags.set_has_final_method(); } 526 bool is_cloneable() const { return _access_flags.is_cloneable(); } 527 void set_is_cloneable() { _access_flags.set_is_cloneable(); } 528 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); } 529 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); } 530 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); } 531 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); } 532 533 // Biased locking support 534 // Note: the prototype header is always set up to be at least the 535 // prototype markOop. If biased locking is enabled it may further be 536 // biasable and have an epoch. 537 markOop prototype_header() const { return _prototype_header; } 538 // NOTE: once instances of this klass are floating around in the 539 // system, this header must only be updated at a safepoint. 540 // NOTE 2: currently we only ever set the prototype header to the 541 // biasable prototype for instanceKlasses. There is no technical 542 // reason why it could not be done for arrayKlasses aside from 543 // wanting to reduce the initial scope of this optimization. There 544 // are potential problems in setting the bias pattern for 545 // JVM-internal oops. 546 inline void set_prototype_header(markOop header); 547 static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); } 548 549 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; } 550 // Atomically increments biased_lock_revocation_count and returns updated value 551 int atomic_incr_biased_lock_revocation_count(); 552 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; } 553 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; } 554 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; } 555 556 TRACE_DEFINE_KLASS_METHODS; 557 558 // garbage collection support 559 void oops_do(OopClosure* cl); 560 561 // Iff the class loader (or mirror for anonymous classes) is alive the 562 // Klass is considered alive. 563 // The is_alive closure passed in depends on the Garbage Collector used. 564 bool is_loader_alive(BoolObjectClosure* is_alive); 565 566 static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true); 567 static void clean_subklass_tree(BoolObjectClosure* is_alive) { 568 clean_weak_klass_links(is_alive, false /* clean_alive_klasses */); 569 } 570 571 // GC specific object visitors 572 // 573 // Mark Sweep 574 virtual void oop_ms_follow_contents(oop obj) = 0; 575 virtual int oop_ms_adjust_pointers(oop obj) = 0; 576 #if INCLUDE_ALL_GCS 577 // Parallel Scavenge 578 virtual void oop_ps_push_contents( oop obj, PSPromotionManager* pm) = 0; 579 // Parallel Compact 580 virtual void oop_pc_follow_contents(oop obj, ParCompactionManager* cm) = 0; 581 virtual void oop_pc_update_pointers(oop obj) = 0; 582 #endif 583 584 // Iterators specialized to particular subtypes 585 // of ExtendedOopClosure, to avoid closure virtual calls. 586 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 587 virtual int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) = 0; \ 588 /* Iterates "closure" over all the oops in "obj" (of type "this") within "mr". */ \ 589 virtual int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* closure, MemRegion mr) = 0; 590 591 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL) 592 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL) 593 594 #if INCLUDE_ALL_GCS 595 #define Klass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ 596 virtual int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) = 0; 597 598 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL) 599 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL) 600 #endif // INCLUDE_ALL_GCS 601 602 virtual void array_klasses_do(void f(Klass* k)) {} 603 604 // Return self, except for abstract classes with exactly 1 605 // implementor. Then return the 1 concrete implementation. 606 Klass *up_cast_abstract(); 607 608 // klass name 609 Symbol* name() const { return _name; } 610 void set_name(Symbol* n); 611 612 public: 613 // jvm support 614 virtual jint compute_modifier_flags(TRAPS) const; 615 616 // JVMTI support 617 virtual jint jvmti_class_status() const; 618 619 // Printing 620 virtual void print_on(outputStream* st) const; 621 622 virtual void oop_print_value_on(oop obj, outputStream* st); 623 virtual void oop_print_on (oop obj, outputStream* st); 624 625 virtual const char* internal_name() const = 0; 626 627 // Verification 628 virtual void verify_on(outputStream* st); 629 void verify() { verify_on(tty); } 630 631 #ifndef PRODUCT 632 bool verify_vtable_index(int index); 633 bool verify_itable_index(int index); 634 #endif 635 636 virtual void oop_verify_on(oop obj, outputStream* st); 637 638 static bool is_null(narrowKlass obj); 639 static bool is_null(Klass* obj); 640 641 // klass encoding for klass pointer in objects. 642 static narrowKlass encode_klass_not_null(Klass* v); 643 static narrowKlass encode_klass(Klass* v); 644 645 static Klass* decode_klass_not_null(narrowKlass v); 646 static Klass* decode_klass(narrowKlass v); 647 648 private: 649 // barriers used by klass_oop_store 650 void klass_update_barrier_set(oop v); 651 void klass_update_barrier_set_pre(oop* p, oop v); 652 }; 653 654 #endif // SHARE_VM_OOPS_KLASS_HPP