1 /* 2 * Copyright (c) 1997, 2018, 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/markOop.hpp" 32 #include "oops/metadata.hpp" 33 #include "oops/oop.hpp" 34 #include "oops/oopHandle.hpp" 35 #include "trace/traceMacros.hpp" 36 #include "utilities/accessFlags.hpp" 37 #include "utilities/macros.hpp" 38 39 // 40 // A Klass provides: 41 // 1: language level class object (method dictionary etc.) 42 // 2: provide vm dispatch behavior for the object 43 // Both functions are combined into one C++ class. 44 45 // One reason for the oop/klass dichotomy in the implementation is 46 // that we don't want a C++ vtbl pointer in every object. Thus, 47 // normal oops don't have any virtual functions. Instead, they 48 // forward all "virtual" functions to their klass, which does have 49 // a vtbl and does the C++ dispatch depending on the object's 50 // actual type. (See oop.inline.hpp for some of the forwarding code.) 51 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"! 52 53 // Forward declarations. 54 template <class T> class Array; 55 template <class T> class GrowableArray; 56 class ClassLoaderData; 57 class fieldDescriptor; 58 class KlassSizeStats; 59 class klassVtable; 60 class ModuleEntry; 61 class PackageEntry; 62 class ParCompactionManager; 63 class PSPromotionManager; 64 class vtableEntry; 65 66 class Klass : public Metadata { 67 friend class VMStructs; 68 friend class JVMCIVMStructs; 69 protected: 70 // If you add a new field that points to any metaspace object, you 71 // must add this field to Klass::metaspace_pointers_do(). 72 73 // note: put frequently-used fields together at start of klass structure 74 // for better cache behavior (may not make much of a difference but sure won't hurt) 75 enum { _primary_super_limit = 8 }; 76 77 // The "layout helper" is a combined descriptor of object layout. 78 // For klasses which are neither instance nor array, the value is zero. 79 // 80 // For instances, layout helper is a positive number, the instance size. 81 // This size is already passed through align_object_size and scaled to bytes. 82 // The low order bit is set if instances of this class cannot be 83 // allocated using the fastpath. 84 // 85 // For arrays, layout helper is a negative number, containing four 86 // distinct bytes, as follows: 87 // MSB:[tag, hsz, ebt, log2(esz)]:LSB 88 // where: 89 // tag is 0x80 if the elements are oops, 0xC0 if non-oops, 0xA0 if value types 90 // hsz is array header size in bytes (i.e., offset of first element) 91 // ebt is the BasicType of the elements 92 // esz is the element size in bytes 93 // This packed word is arranged so as to be quickly unpacked by the 94 // various fast paths that use the various subfields. 95 // 96 // The esz bits can be used directly by a SLL instruction, without masking. 97 // 98 // Note that the array-kind tag looks like 0x00 for instance klasses, 99 // since their length in bytes is always less than 24Mb. 100 // 101 // Final note: This comes first, immediately after C++ vtable, 102 // because it is frequently queried. 103 jint _layout_helper; 104 105 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers 106 // and _primary_supers all help make fast subtype checks. See big discussion 107 // in doc/server_compiler/checktype.txt 108 // 109 // Where to look to observe a supertype (it is &_secondary_super_cache for 110 // secondary supers, else is &_primary_supers[depth()]. 111 juint _super_check_offset; 112 113 // Class name. Instance classes: java/lang/String, etc. Array classes: [I, 114 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes. 115 Symbol* _name; 116 117 // Cache of last observed secondary supertype 118 Klass* _secondary_super_cache; 119 // Array of all secondary supertypes 120 Array<Klass*>* _secondary_supers; 121 // Ordered list of all primary supertypes 122 Klass* _primary_supers[_primary_super_limit]; 123 // java/lang/Class instance mirroring this class 124 OopHandle _java_mirror; 125 // Superclass 126 Klass* _super; 127 // First subclass (NULL if none); _subklass->next_sibling() is next one 128 Klass* _subklass; 129 // Sibling link (or NULL); links all subklasses of a klass 130 Klass* _next_sibling; 131 132 // All klasses loaded by a class loader are chained through these links 133 Klass* _next_link; 134 135 // The VM's representation of the ClassLoader used to load this class. 136 // Provide access the corresponding instance java.lang.ClassLoader. 137 ClassLoaderData* _class_loader_data; 138 139 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers. 140 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here. 141 142 TRACE_DEFINE_TRACE_ID_FIELD; 143 144 // Biased locking implementation and statistics 145 // (the 64-bit chunk goes first, to avoid some fragmentation) 146 jlong _last_biased_lock_bulk_revocation_time; 147 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type 148 jint _biased_lock_revocation_count; 149 150 // vtable length 151 int _vtable_len; 152 153 private: 154 // This is an index into FileMapHeader::_classpath_entry_table[], to 155 // associate this class with the JAR file where it's loaded from during 156 // dump time. If a class is not loaded from the shared archive, this field is 157 // -1. 158 jshort _shared_class_path_index; 159 160 friend class SharedClassUtil; 161 protected: 162 163 // Constructor 164 Klass(); 165 166 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, bool is_value, TRAPS) throw(); 167 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() { 168 return operator new (size, loader_data, word_size, false, THREAD); 169 } 170 171 public: 172 enum DefaultsLookupMode { find_defaults, skip_defaults }; 173 enum OverpassLookupMode { find_overpass, skip_overpass }; 174 enum StaticLookupMode { find_static, skip_static }; 175 enum PrivateLookupMode { find_private, skip_private }; 176 177 bool is_klass() const volatile { return true; } 178 179 // super 180 Klass* super() const { return _super; } 181 void set_super(Klass* k) { _super = k; } 182 183 // initializes _super link, _primary_supers & _secondary_supers arrays 184 void initialize_supers(Klass* k, TRAPS); 185 void initialize_supers_impl1(Klass* k); 186 void initialize_supers_impl2(Klass* k); 187 188 // klass-specific helper for initializing _secondary_supers 189 virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots); 190 191 // java_super is the Java-level super type as specified by Class.getSuperClass. 192 virtual Klass* java_super() const { return NULL; } 193 194 juint super_check_offset() const { return _super_check_offset; } 195 void set_super_check_offset(juint o) { _super_check_offset = o; } 196 197 Klass* secondary_super_cache() const { return _secondary_super_cache; } 198 void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; } 199 200 Array<Klass*>* secondary_supers() const { return _secondary_supers; } 201 void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; } 202 203 // Return the element of the _super chain of the given depth. 204 // If there is no such element, return either NULL or this. 205 Klass* primary_super_of_depth(juint i) const { 206 assert(i < primary_super_limit(), "oob"); 207 Klass* super = _primary_supers[i]; 208 assert(super == NULL || super->super_depth() == i, "correct display"); 209 return super; 210 } 211 212 // Can this klass be a primary super? False for interfaces and arrays of 213 // interfaces. False also for arrays or classes with long super chains. 214 bool can_be_primary_super() const { 215 const juint secondary_offset = in_bytes(secondary_super_cache_offset()); 216 return super_check_offset() != secondary_offset; 217 } 218 virtual bool can_be_primary_super_slow() const; 219 220 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit]. 221 juint super_depth() const { 222 if (!can_be_primary_super()) { 223 return primary_super_limit(); 224 } else { 225 juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*); 226 assert(d < primary_super_limit(), "oob"); 227 assert(_primary_supers[d] == this, "proper init"); 228 return d; 229 } 230 } 231 232 // java mirror 233 oop java_mirror() const; 234 void set_java_mirror(Handle m); 235 236 // Temporary mirror switch used by RedefineClasses 237 // Both mirrors are on the ClassLoaderData::_handles list already so no 238 // barriers are needed. 239 void set_java_mirror_handle(OopHandle mirror) { _java_mirror = mirror; } 240 OopHandle java_mirror_handle() const { return _java_mirror; } 241 242 // modifier flags 243 jint modifier_flags() const { return _modifier_flags; } 244 void set_modifier_flags(jint flags) { _modifier_flags = flags; } 245 246 // size helper 247 int layout_helper() const { return _layout_helper; } 248 void set_layout_helper(int lh) { _layout_helper = lh; } 249 250 // Note: for instances layout_helper() may include padding. 251 // Use InstanceKlass::contains_field_offset to classify field offsets. 252 253 // sub/superklass links 254 Klass* subklass() const { return _subklass; } 255 Klass* next_sibling() const { return _next_sibling; } 256 InstanceKlass* superklass() const; 257 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list 258 259 void set_next_link(Klass* k) { _next_link = k; } 260 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader. 261 262 // class loader data 263 ClassLoaderData* class_loader_data() const { return _class_loader_data; } 264 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; } 265 266 int shared_classpath_index() const { 267 return _shared_class_path_index; 268 }; 269 270 void set_shared_classpath_index(int index) { 271 _shared_class_path_index = index; 272 }; 273 274 // Obtain the module or package for this class 275 virtual ModuleEntry* module() const = 0; 276 virtual PackageEntry* package() const = 0; 277 278 protected: // internal accessors 279 void set_subklass(Klass* s); 280 void set_next_sibling(Klass* s); 281 282 public: 283 284 // Compiler support 285 static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); } 286 static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); } 287 static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); } 288 static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); } 289 static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); } 290 static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); } 291 static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); } 292 static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); } 293 static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); } 294 295 // Unpacking layout_helper: 296 enum { 297 _lh_neutral_value = 0, // neutral non-array non-instance value 298 _lh_instance_slow_path_bit = 0x01, 299 _lh_log2_element_size_shift = BitsPerByte*0, 300 _lh_log2_element_size_mask = BitsPerLong-1, 301 _lh_element_type_shift = BitsPerByte*1, 302 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask 303 _lh_header_size_shift = BitsPerByte*2, 304 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask 305 _lh_array_tag_bits = 3, 306 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits 307 }; 308 309 static const unsigned int _lh_array_tag_type_value = 0Xfffffffc; 310 static const unsigned int _lh_array_tag_vt_value = 0Xfffffffd; 311 static const unsigned int _lh_array_tag_obj_value = 0Xfffffffe; 312 313 static int layout_helper_size_in_bytes(jint lh) { 314 assert(lh > (jint)_lh_neutral_value, "must be instance"); 315 return (int) lh & ~_lh_instance_slow_path_bit; 316 } 317 static bool layout_helper_needs_slow_path(jint lh) { 318 assert(lh > (jint)_lh_neutral_value, "must be instance"); 319 return (lh & _lh_instance_slow_path_bit) != 0; 320 } 321 static bool layout_helper_is_instance(jint lh) { 322 return (jint)lh > (jint)_lh_neutral_value; 323 } 324 static bool layout_helper_is_array(jint lh) { 325 return (jint)lh < (jint)_lh_neutral_value; 326 } 327 static bool layout_helper_is_typeArray(jint lh) { 328 return (juint) _lh_array_tag_type_value == (juint)(lh >> _lh_array_tag_shift); 329 } 330 static bool layout_helper_is_objArray(jint lh) { 331 return (juint)_lh_array_tag_obj_value == (juint)(lh >> _lh_array_tag_shift); 332 } 333 static bool layout_helper_is_valueArray(jint lh) { 334 return (juint)_lh_array_tag_vt_value == (juint)(lh >> _lh_array_tag_shift); 335 } 336 static int layout_helper_header_size(jint lh) { 337 assert(lh < (jint)_lh_neutral_value, "must be array"); 338 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask; 339 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity"); 340 return hsize; 341 } 342 static BasicType layout_helper_element_type(jint lh) { 343 assert(lh < (jint)_lh_neutral_value, "must be array"); 344 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask; 345 assert((btvalue >= T_BOOLEAN && btvalue <= T_OBJECT) || btvalue == T_VALUETYPE, "sanity"); 346 return (BasicType) btvalue; 347 } 348 349 // Want a pattern to quickly diff against layout header in register 350 // find something less clever! 351 static int layout_helper_boolean_diffbit() { 352 jint zlh = array_layout_helper(T_BOOLEAN); 353 jint blh = array_layout_helper(T_BYTE); 354 assert(zlh != blh, "array layout helpers must differ"); 355 int diffbit = 1; 356 while ((diffbit & (zlh ^ blh)) == 0 && (diffbit & zlh) == 0) { 357 diffbit <<= 1; 358 assert(diffbit != 0, "make sure T_BOOLEAN has a different bit than T_BYTE"); 359 } 360 return diffbit; 361 } 362 363 static int layout_helper_log2_element_size(jint lh) { 364 assert(lh < (jint)_lh_neutral_value, "must be array"); 365 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask; 366 assert(layout_helper_element_type(lh) == T_VALUETYPE || l2esz <= LogBytesPerLong, 367 "sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh); 368 return l2esz; 369 } 370 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) { 371 return (tag << _lh_array_tag_shift) 372 | (hsize << _lh_header_size_shift) 373 | ((int)etype << _lh_element_type_shift) 374 | (log2_esize << _lh_log2_element_size_shift); 375 } 376 static jint instance_layout_helper(jint size, bool slow_path_flag) { 377 return (size << LogBytesPerWord) 378 | (slow_path_flag ? _lh_instance_slow_path_bit : 0); 379 } 380 static int layout_helper_to_size_helper(jint lh) { 381 assert(lh > (jint)_lh_neutral_value, "must be instance"); 382 // Note that the following expression discards _lh_instance_slow_path_bit. 383 return lh >> LogBytesPerWord; 384 } 385 // Out-of-line version computes everything based on the etype: 386 static jint array_layout_helper(BasicType etype); 387 388 // What is the maximum number of primary superclasses any klass can have? 389 #ifdef PRODUCT 390 static juint primary_super_limit() { return _primary_super_limit; } 391 #else 392 static juint primary_super_limit() { 393 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob"); 394 return FastSuperclassLimit; 395 } 396 #endif 397 398 // vtables 399 klassVtable vtable() const; 400 int vtable_length() const { return _vtable_len; } 401 402 // subclass check 403 bool is_subclass_of(const Klass* k) const; 404 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it 405 bool is_subtype_of(Klass* k) const { 406 juint off = k->super_check_offset(); 407 Klass* sup = *(Klass**)( (address)this + off ); 408 const juint secondary_offset = in_bytes(secondary_super_cache_offset()); 409 if (sup == k) { 410 return true; 411 } else if (off != secondary_offset) { 412 return false; 413 } else { 414 return search_secondary_supers(k); 415 } 416 } 417 418 // Is an oop/narrowOop null or subtype of this Klass? 419 template <typename T> 420 bool is_instanceof_or_null(T element); 421 422 bool search_secondary_supers(Klass* k) const; 423 424 // Find LCA in class hierarchy 425 Klass *LCA( Klass *k ); 426 427 // Check whether reflection/jni/jvm code is allowed to instantiate this class; 428 // if not, throw either an Error or an Exception. 429 virtual void check_valid_for_instantiation(bool throwError, TRAPS); 430 431 // array copying 432 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS); 433 434 // tells if the class should be initialized 435 virtual bool should_be_initialized() const { return false; } 436 // initializes the klass 437 virtual void initialize(TRAPS); 438 // lookup operation for MethodLookupCache 439 friend class MethodLookupCache; 440 virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const; 441 virtual Method* uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const; 442 public: 443 Method* lookup_method(const Symbol* name, const Symbol* signature) const { 444 return uncached_lookup_method(name, signature, find_overpass); 445 } 446 447 // array class with specific rank 448 Klass* array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); } 449 450 // array class with this klass as element type 451 Klass* array_klass(TRAPS) { return array_klass_impl(false, THREAD); } 452 453 // These will return NULL instead of allocating on the heap: 454 // NB: these can block for a mutex, like other functions with TRAPS arg. 455 Klass* array_klass_or_null(int rank); 456 Klass* array_klass_or_null(); 457 458 virtual oop protection_domain() const = 0; 459 460 oop class_loader() const; 461 462 virtual oop klass_holder() const { return class_loader(); } 463 464 protected: 465 virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS); 466 virtual Klass* array_klass_impl(bool or_null, TRAPS); 467 468 void set_vtable_length(int len) { _vtable_len= len; } 469 470 vtableEntry* start_of_vtable() const; 471 public: 472 Method* method_at_vtable(int index); 473 474 static ByteSize vtable_start_offset(); 475 static ByteSize vtable_length_offset() { 476 return byte_offset_of(Klass, _vtable_len); 477 } 478 479 // CDS support - remove and restore oops from metadata. Oops are not shared. 480 virtual void remove_unshareable_info(); 481 virtual void remove_java_mirror(); 482 virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS); 483 484 protected: 485 // computes the subtype relationship 486 virtual bool compute_is_subtype_of(Klass* k); 487 public: 488 // subclass accessor (here for convenience; undefined for non-klass objects) 489 virtual bool is_leaf_class() const { fatal("not a class"); return false; } 490 public: 491 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP 492 // These functions describe behavior for the oop not the KLASS. 493 494 // actual oop size of obj in memory 495 virtual int oop_size(oop obj) const = 0; 496 497 // Size of klass in word size. 498 virtual int size() const = 0; 499 #if INCLUDE_SERVICES 500 virtual void collect_statistics(KlassSizeStats *sz) const; 501 #endif 502 503 // Returns the Java name for a class (Resource allocated) 504 // For arrays, this returns the name of the element with a leading '['. 505 // For classes, this returns the name with the package separators 506 // turned into '.'s. 507 const char* external_name() const; 508 // Returns the name for a class (Resource allocated) as the class 509 // would appear in a signature. 510 // For arrays, this returns the name of the element with a leading '['. 511 // For classes, this returns the name with a leading 'L' and a trailing ';' 512 // and the package separators as '/'. 513 virtual const char* signature_name() const; 514 515 const char* class_loader_and_module_name() const; 516 517 // type testing operations 518 #ifdef ASSERT 519 protected: 520 virtual bool is_instance_klass_slow() const { return false; } 521 virtual bool is_array_klass_slow() const { return false; } 522 virtual bool is_objArray_klass_slow() const { return false; } 523 virtual bool is_typeArray_klass_slow() const { return false; } 524 virtual bool is_valueArray_klass_slow() const { return false; } 525 #endif // ASSERT 526 // current implementation uses this method even in non debug builds 527 virtual bool is_value_slow() const { return false; } 528 public: 529 530 // Fast non-virtual versions 531 #ifndef ASSERT 532 #define assert_same_query(xval, xcheck) xval 533 #else 534 private: 535 static bool assert_same_query(bool xval, bool xslow) { 536 assert(xval == xslow, "slow and fast queries agree"); 537 return xval; 538 } 539 public: 540 #endif 541 inline bool is_instance_klass() const { return assert_same_query( 542 layout_helper_is_instance(layout_helper()), 543 is_instance_klass_slow()); } 544 inline bool is_array_klass() const { return assert_same_query( 545 layout_helper_is_array(layout_helper()), 546 is_array_klass_slow()); } 547 inline bool is_objArray_klass() const { return assert_same_query( 548 layout_helper_is_objArray(layout_helper()), 549 is_objArray_klass_slow()); } 550 inline bool is_typeArray_klass() const { return assert_same_query( 551 layout_helper_is_typeArray(layout_helper()), 552 is_typeArray_klass_slow()); } 553 inline bool is_value() const { return is_value_slow(); } //temporary hack 554 inline bool is_valueArray_klass() const { return assert_same_query( 555 layout_helper_is_valueArray(layout_helper()), 556 is_valueArray_klass_slow()); } 557 558 #undef assert_same_query 559 560 // Access flags 561 AccessFlags access_flags() const { return _access_flags; } 562 void set_access_flags(AccessFlags flags) { _access_flags = flags; } 563 564 bool is_public() const { return _access_flags.is_public(); } 565 bool is_final() const { return _access_flags.is_final(); } 566 bool is_interface() const { return _access_flags.is_interface(); } 567 bool is_abstract() const { return _access_flags.is_abstract(); } 568 bool is_super() const { return _access_flags.is_super(); } 569 bool is_synthetic() const { return _access_flags.is_synthetic(); } 570 void set_is_synthetic() { _access_flags.set_is_synthetic(); } 571 bool has_finalizer() const { return _access_flags.has_finalizer(); } 572 bool has_final_method() const { return _access_flags.has_final_method(); } 573 void set_has_finalizer() { _access_flags.set_has_finalizer(); } 574 void set_has_final_method() { _access_flags.set_has_final_method(); } 575 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); } 576 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); } 577 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); } 578 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); } 579 bool is_shared() const { return access_flags().is_shared_class(); } // shadows MetaspaceObj::is_shared)() 580 void set_is_shared() { _access_flags.set_is_shared_class(); } 581 582 bool is_cloneable() const; 583 void set_is_cloneable(); 584 585 // Biased locking support 586 // Note: the prototype header is always set up to be at least the 587 // prototype markOop. If biased locking is enabled it may further be 588 // biasable and have an epoch. 589 markOop prototype_header() const { return _prototype_header; } 590 static inline markOop default_prototype_header(Klass* k) { 591 return (k == NULL) ? markOopDesc::prototype() : k->prototype_header(); 592 } 593 // NOTE: once instances of this klass are floating around in the 594 // system, this header must only be updated at a safepoint. 595 // NOTE 2: currently we only ever set the prototype header to the 596 // biasable prototype for instanceKlasses. There is no technical 597 // reason why it could not be done for arrayKlasses aside from 598 // wanting to reduce the initial scope of this optimization. There 599 // are potential problems in setting the bias pattern for 600 // JVM-internal oops. 601 inline void set_prototype_header(markOop header); 602 static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); } 603 604 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; } 605 // Atomically increments biased_lock_revocation_count and returns updated value 606 int atomic_incr_biased_lock_revocation_count(); 607 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; } 608 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; } 609 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; } 610 611 TRACE_DEFINE_TRACE_ID_METHODS; 612 613 virtual void metaspace_pointers_do(MetaspaceClosure* iter); 614 virtual MetaspaceObj::Type type() const { return ClassType; } 615 616 // Iff the class loader (or mirror for anonymous classes) is alive the 617 // Klass is considered alive. 618 // The is_alive closure passed in depends on the Garbage Collector used. 619 bool is_loader_alive(BoolObjectClosure* is_alive); 620 621 static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true); 622 static void clean_subklass_tree(BoolObjectClosure* is_alive) { 623 clean_weak_klass_links(is_alive, false /* clean_alive_klasses */); 624 } 625 626 // GC specific object visitors 627 // 628 #if INCLUDE_ALL_GCS 629 // Parallel Scavenge 630 virtual void oop_ps_push_contents( oop obj, PSPromotionManager* pm) = 0; 631 // Parallel Compact 632 virtual void oop_pc_follow_contents(oop obj, ParCompactionManager* cm) = 0; 633 virtual void oop_pc_update_pointers(oop obj, ParCompactionManager* cm) = 0; 634 #endif 635 636 // Iterators specialized to particular subtypes 637 // of ExtendedOopClosure, to avoid closure virtual calls. 638 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 639 virtual void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) = 0; \ 640 /* Iterates "closure" over all the oops in "obj" (of type "this") within "mr". */ \ 641 virtual void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) = 0; 642 643 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL) 644 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL) 645 646 #if INCLUDE_ALL_GCS 647 #define Klass_OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \ 648 virtual void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) = 0; 649 650 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS) 651 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS) 652 #endif // INCLUDE_ALL_GCS 653 654 virtual void array_klasses_do(void f(Klass* k)) {} 655 656 // Return self, except for abstract classes with exactly 1 657 // implementor. Then return the 1 concrete implementation. 658 Klass *up_cast_abstract(); 659 660 // klass name 661 Symbol* name() const { return _name; } 662 void set_name(Symbol* n); 663 664 public: 665 // jvm support 666 virtual jint compute_modifier_flags(TRAPS) const; 667 668 // JVMTI support 669 virtual jint jvmti_class_status() const; 670 671 // Printing 672 virtual void print_on(outputStream* st) const; 673 674 virtual void oop_print_value_on(oop obj, outputStream* st); 675 virtual void oop_print_on (oop obj, outputStream* st); 676 677 virtual const char* internal_name() const = 0; 678 679 // Verification 680 virtual void verify_on(outputStream* st); 681 void verify() { verify_on(tty); } 682 683 #ifndef PRODUCT 684 bool verify_vtable_index(int index); 685 bool verify_itable_index(int index); 686 #endif 687 688 virtual void oop_verify_on(oop obj, outputStream* st); 689 690 static bool is_null(narrowKlass obj); 691 static bool is_null(Klass* obj); 692 693 // klass encoding for klass pointer in objects. 694 static narrowKlass encode_klass_not_null(Klass* v); 695 static narrowKlass encode_klass(Klass* v); 696 697 static Klass* decode_klass_not_null(narrowKlass v); 698 static Klass* decode_klass(narrowKlass v); 699 700 static bool decode_ptr_is_value_type(narrowKlass v); 701 static bool ptr_is_value_type(Klass* v); 702 }; 703 704 // Helper to convert the oop iterate macro suffixes into bool values that can be used by template functions. 705 #define nvs_nv_to_bool true 706 #define nvs_v_to_bool false 707 #define nvs_to_bool(nv_suffix) nvs##nv_suffix##_to_bool 708 709 // Oop iteration macros for declarations. 710 // Used to generate declarations in the *Klass header files. 711 712 #define OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 713 void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure); \ 714 void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr); 715 716 #if INCLUDE_ALL_GCS 717 #define OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \ 718 void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure); 719 #endif // INCLUDE_ALL_GCS 720 721 722 // Oop iteration macros for definitions. 723 // Used to generate definitions in the *Klass.inline.hpp files. 724 725 #define OOP_OOP_ITERATE_DEFN(KlassType, OopClosureType, nv_suffix) \ 726 void KlassType::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \ 727 oop_oop_iterate<nvs_to_bool(nv_suffix)>(obj, closure); \ 728 } 729 730 #if INCLUDE_ALL_GCS 731 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix) \ 732 void KlassType::oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) { \ 733 oop_oop_iterate_reverse<nvs_to_bool(nv_suffix)>(obj, closure); \ 734 } 735 #else 736 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix) 737 #endif 738 739 #define OOP_OOP_ITERATE_DEFN_BOUNDED(KlassType, OopClosureType, nv_suffix) \ 740 void KlassType::oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) { \ 741 oop_oop_iterate_bounded<nvs_to_bool(nv_suffix)>(obj, closure, mr); \ 742 } 743 744 #endif // SHARE_VM_OOPS_KLASS_HPP