1 /* 2 * Copyright (c) 1997, 2016, 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 "memory/genOopClosures.hpp" 29 #include "memory/iterator.hpp" 30 #include "memory/memRegion.hpp" 31 #include "memory/specialized_oop_closures.hpp" 32 #include "oops/klassPS.hpp" 33 #include "oops/metadata.hpp" 34 #include "oops/oop.hpp" 35 #include "trace/traceMacros.hpp" 36 #include "evtrace/traceMacros.hpp" 37 #include "utilities/accessFlags.hpp" 38 #include "utilities/macros.hpp" 39 #if INCLUDE_ALL_GCS 40 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp" 41 #include "gc_implementation/g1/g1OopClosures.hpp" 42 #include "gc_implementation/parNew/parOopClosures.hpp" 43 #endif // INCLUDE_ALL_GCS 44 45 // 46 // A Klass provides: 47 // 1: language level class object (method dictionary etc.) 48 // 2: provide vm dispatch behavior for the object 49 // Both functions are combined into one C++ class. 50 51 // One reason for the oop/klass dichotomy in the implementation is 52 // that we don't want a C++ vtbl pointer in every object. Thus, 53 // normal oops don't have any virtual functions. Instead, they 54 // forward all "virtual" functions to their klass, which does have 55 // a vtbl and does the C++ dispatch depending on the object's 56 // actual type. (See oop.inline.hpp for some of the forwarding code.) 57 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"! 58 59 // Klass layout: 60 // [C++ vtbl ptr ] (contained in Metadata) 61 // [layout_helper ] 62 // [super_check_offset ] for fast subtype checks 63 // [name ] 64 // [secondary_super_cache] for fast subtype checks 65 // [secondary_supers ] array of 2ndary supertypes 66 // [primary_supers 0] 67 // [primary_supers 1] 68 // [primary_supers 2] 69 // ... 70 // [primary_supers 7] 71 // [java_mirror ] 72 // [super ] 73 // [subklass ] first subclass 74 // [next_sibling ] link to chain additional subklasses 75 // [next_link ] 76 // [class_loader_data] 77 // [modifier_flags] 78 // [access_flags ] 79 // [last_biased_lock_bulk_revocation_time] (64 bits) 80 // [prototype_header] 81 // [biased_lock_revocation_count] 82 // [_modified_oops] 83 // [_accumulated_modified_oops] 84 // [trace_id] 85 86 87 // Forward declarations. 88 template <class T> class Array; 89 template <class T> class GrowableArray; 90 class ClassLoaderData; 91 class klassVtable; 92 class ParCompactionManager; 93 class KlassSizeStats; 94 class fieldDescriptor; 95 96 class Klass : public Metadata { 97 friend class VMStructs; 98 protected: 99 // note: put frequently-used fields together at start of klass structure 100 // for better cache behavior (may not make much of a difference but sure won't hurt) 101 enum { _primary_super_limit = 8 }; 102 103 // The "layout helper" is a combined descriptor of object layout. 104 // For klasses which are neither instance nor array, the value is zero. 105 // 106 // For instances, layout helper is a positive number, the instance size. 107 // This size is already passed through align_object_size and scaled to bytes. 108 // The low order bit is set if instances of this class cannot be 109 // allocated using the fastpath. 110 // 111 // For arrays, layout helper is a negative number, containing four 112 // distinct bytes, as follows: 113 // MSB:[tag, hsz, ebt, log2(esz)]:LSB 114 // where: 115 // tag is 0x80 if the elements are oops, 0xC0 if non-oops 116 // hsz is array header size in bytes (i.e., offset of first element) 117 // ebt is the BasicType of the elements 118 // esz is the element size in bytes 119 // This packed word is arranged so as to be quickly unpacked by the 120 // various fast paths that use the various subfields. 121 // 122 // The esz bits can be used directly by a SLL instruction, without masking. 123 // 124 // Note that the array-kind tag looks like 0x00 for instance klasses, 125 // since their length in bytes is always less than 24Mb. 126 // 127 // Final note: This comes first, immediately after C++ vtable, 128 // because it is frequently queried. 129 jint _layout_helper; 130 131 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers 132 // and _primary_supers all help make fast subtype checks. See big discussion 133 // in doc/server_compiler/checktype.txt 134 // 135 // Where to look to observe a supertype (it is &_secondary_super_cache for 136 // secondary supers, else is &_primary_supers[depth()]. 137 juint _super_check_offset; 138 139 // Class name. Instance classes: java/lang/String, etc. Array classes: [I, 140 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes. 141 Symbol* _name; 142 143 // Cache of last observed secondary supertype 144 Klass* _secondary_super_cache; 145 // Array of all secondary supertypes 146 Array<Klass*>* _secondary_supers; 147 // Ordered list of all primary supertypes 148 Klass* _primary_supers[_primary_super_limit]; 149 // java/lang/Class instance mirroring this class 150 oop _java_mirror; 151 // Superclass 152 Klass* _super; 153 // First subclass (NULL if none); _subklass->next_sibling() is next one 154 Klass* _subklass; 155 // Sibling link (or NULL); links all subklasses of a klass 156 Klass* _next_sibling; 157 158 // All klasses loaded by a class loader are chained through these links 159 Klass* _next_link; 160 161 // The VM's representation of the ClassLoader used to load this class. 162 // Provide access the corresponding instance java.lang.ClassLoader. 163 ClassLoaderData* _class_loader_data; 164 165 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers. 166 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here. 167 168 // Biased locking implementation and statistics 169 // (the 64-bit chunk goes first, to avoid some fragmentation) 170 jlong _last_biased_lock_bulk_revocation_time; 171 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type 172 jint _biased_lock_revocation_count; 173 174 TRACE_DEFINE_KLASS_TRACE_ID; 175 176 EVTRACE_DECLARE_TRACKED_CLASS_FIELDS; 177 178 // Remembered sets support for the oops in the klasses. 179 jbyte _modified_oops; // Card Table Equivalent (YC/CMS support) 180 jbyte _accumulated_modified_oops; // Mod Union Equivalent (CMS support) 181 182 private: 183 // This is an index into FileMapHeader::_classpath_entry_table[], to 184 // associate this class with the JAR file where it's loaded from during 185 // dump time. If a class is not loaded from the shared archive, this field is 186 // -1. 187 jshort _shared_class_path_index; 188 189 friend class SharedClassUtil; 190 protected: 191 192 // Constructor 193 Klass(); 194 195 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw(); 196 197 public: 198 enum MethodLookupMode { normal, skip_overpass, skip_defaults }; 199 200 bool is_klass() const volatile { return true; } 201 202 // super 203 Klass* super() const { return _super; } 204 void set_super(Klass* k) { _super = k; } 205 206 // initializes _super link, _primary_supers & _secondary_supers arrays 207 void initialize_supers(Klass* k, TRAPS); 208 void initialize_supers_impl1(Klass* k); 209 void initialize_supers_impl2(Klass* k); 210 211 // klass-specific helper for initializing _secondary_supers 212 virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots); 213 214 // java_super is the Java-level super type as specified by Class.getSuperClass. 215 virtual Klass* java_super() const { return NULL; } 216 217 juint super_check_offset() const { return _super_check_offset; } 218 void set_super_check_offset(juint o) { _super_check_offset = o; } 219 220 Klass* secondary_super_cache() const { return _secondary_super_cache; } 221 void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; } 222 223 Array<Klass*>* secondary_supers() const { return _secondary_supers; } 224 void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; } 225 226 // Return the element of the _super chain of the given depth. 227 // If there is no such element, return either NULL or this. 228 Klass* primary_super_of_depth(juint i) const { 229 assert(i < primary_super_limit(), "oob"); 230 Klass* super = _primary_supers[i]; 231 assert(super == NULL || super->super_depth() == i, "correct display"); 232 return super; 233 } 234 235 // Can this klass be a primary super? False for interfaces and arrays of 236 // interfaces. False also for arrays or classes with long super chains. 237 bool can_be_primary_super() const { 238 const juint secondary_offset = in_bytes(secondary_super_cache_offset()); 239 return super_check_offset() != secondary_offset; 240 } 241 virtual bool can_be_primary_super_slow() const; 242 243 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit]. 244 juint super_depth() const { 245 if (!can_be_primary_super()) { 246 return primary_super_limit(); 247 } else { 248 juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*); 249 assert(d < primary_super_limit(), "oob"); 250 assert(_primary_supers[d] == this, "proper init"); 251 return d; 252 } 253 } 254 255 // store an oop into a field of a Klass 256 void klass_oop_store(oop* p, oop v); 257 void klass_oop_store(volatile oop* p, oop v); 258 259 // java mirror 260 oop java_mirror() const { return _java_mirror; } 261 void set_java_mirror(oop m) { klass_oop_store(&_java_mirror, m); } 262 263 // modifier flags 264 jint modifier_flags() const { return _modifier_flags; } 265 void set_modifier_flags(jint flags) { _modifier_flags = flags; } 266 267 // size helper 268 int layout_helper() const { return _layout_helper; } 269 void set_layout_helper(int lh) { _layout_helper = lh; } 270 271 // Note: for instances layout_helper() may include padding. 272 // Use InstanceKlass::contains_field_offset to classify field offsets. 273 274 // sub/superklass links 275 InstanceKlass* superklass() const; 276 Klass* subklass() const; 277 Klass* next_sibling() const; 278 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list 279 280 void set_next_link(Klass* k) { _next_link = k; } 281 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader. 282 283 // class loader data 284 ClassLoaderData* class_loader_data() const { return _class_loader_data; } 285 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; } 286 287 // The Klasses are not placed in the Heap, so the Card Table or 288 // the Mod Union Table can't be used to mark when klasses have modified oops. 289 // The CT and MUT bits saves this information for the individual Klasses. 290 void record_modified_oops() { _modified_oops = 1; } 291 void clear_modified_oops() { _modified_oops = 0; } 292 bool has_modified_oops() { return _modified_oops == 1; } 293 294 void accumulate_modified_oops() { if (has_modified_oops()) _accumulated_modified_oops = 1; } 295 void clear_accumulated_modified_oops() { _accumulated_modified_oops = 0; } 296 bool has_accumulated_modified_oops() { return _accumulated_modified_oops == 1; } 297 298 int shared_classpath_index() const { 299 return _shared_class_path_index; 300 }; 301 302 void set_shared_classpath_index(int index) { 303 _shared_class_path_index = index; 304 }; 305 306 307 protected: // internal accessors 308 Klass* subklass_oop() const { return _subklass; } 309 Klass* next_sibling_oop() const { return _next_sibling; } 310 void set_subklass(Klass* s); 311 void set_next_sibling(Klass* s); 312 313 public: 314 315 // Compiler support 316 static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); } 317 static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); } 318 static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); } 319 static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); } 320 static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); } 321 static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); } 322 static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); } 323 static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); } 324 static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); } 325 326 // Unpacking layout_helper: 327 enum { 328 _lh_neutral_value = 0, // neutral non-array non-instance value 329 _lh_instance_slow_path_bit = 0x01, 330 _lh_log2_element_size_shift = BitsPerByte*0, 331 _lh_log2_element_size_mask = BitsPerLong-1, 332 _lh_element_type_shift = BitsPerByte*1, 333 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask 334 _lh_header_size_shift = BitsPerByte*2, 335 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask 336 _lh_array_tag_bits = 2, 337 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits, 338 _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30 339 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30 340 }; 341 342 static int layout_helper_size_in_bytes(jint lh) { 343 assert(lh > (jint)_lh_neutral_value, "must be instance"); 344 return (int) lh & ~_lh_instance_slow_path_bit; 345 } 346 static bool layout_helper_needs_slow_path(jint lh) { 347 assert(lh > (jint)_lh_neutral_value, "must be instance"); 348 return (lh & _lh_instance_slow_path_bit) != 0; 349 } 350 static bool layout_helper_is_instance(jint lh) { 351 return (jint)lh > (jint)_lh_neutral_value; 352 } 353 static bool layout_helper_is_array(jint lh) { 354 return (jint)lh < (jint)_lh_neutral_value; 355 } 356 static bool layout_helper_is_typeArray(jint lh) { 357 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift); 358 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift); 359 } 360 static bool layout_helper_is_objArray(jint lh) { 361 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift); 362 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift); 363 } 364 static int layout_helper_header_size(jint lh) { 365 assert(lh < (jint)_lh_neutral_value, "must be array"); 366 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask; 367 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity"); 368 return hsize; 369 } 370 static BasicType layout_helper_element_type(jint lh) { 371 assert(lh < (jint)_lh_neutral_value, "must be array"); 372 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask; 373 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity"); 374 return (BasicType) btvalue; 375 } 376 377 // Want a pattern to quickly diff against layout header in register 378 // find something less clever! 379 static int layout_helper_boolean_diffbit() { 380 jint zlh = array_layout_helper(T_BOOLEAN); 381 jint blh = array_layout_helper(T_BYTE); 382 assert(zlh != blh, "array layout helpers must differ"); 383 int diffbit = 1; 384 while ((diffbit & (zlh ^ blh)) == 0 && (diffbit & zlh) == 0) { 385 diffbit <<= 1; 386 assert(diffbit != 0, "make sure T_BOOLEAN has a different bit than T_BYTE"); 387 } 388 return diffbit; 389 } 390 391 static int layout_helper_log2_element_size(jint lh) { 392 assert(lh < (jint)_lh_neutral_value, "must be array"); 393 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask; 394 assert(l2esz <= LogBitsPerLong, 395 err_msg("sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh)); 396 return l2esz; 397 } 398 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) { 399 return (tag << _lh_array_tag_shift) 400 | (hsize << _lh_header_size_shift) 401 | ((int)etype << _lh_element_type_shift) 402 | (log2_esize << _lh_log2_element_size_shift); 403 } 404 static jint instance_layout_helper(jint size, bool slow_path_flag) { 405 return (size << LogHeapWordSize) 406 | (slow_path_flag ? _lh_instance_slow_path_bit : 0); 407 } 408 static int layout_helper_to_size_helper(jint lh) { 409 assert(lh > (jint)_lh_neutral_value, "must be instance"); 410 // Note that the following expression discards _lh_instance_slow_path_bit. 411 return lh >> LogHeapWordSize; 412 } 413 // Out-of-line version computes everything based on the etype: 414 static jint array_layout_helper(BasicType etype); 415 416 // What is the maximum number of primary superclasses any klass can have? 417 #ifdef PRODUCT 418 static juint primary_super_limit() { return _primary_super_limit; } 419 #else 420 static juint primary_super_limit() { 421 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob"); 422 return FastSuperclassLimit; 423 } 424 #endif 425 426 // vtables 427 virtual klassVtable* vtable() const { return NULL; } 428 virtual int vtable_length() const { return 0; } 429 430 // subclass check 431 bool is_subclass_of(const Klass* k) const; 432 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it 433 bool is_subtype_of(Klass* k) const { 434 juint off = k->super_check_offset(); 435 Klass* sup = *(Klass**)( (address)this + off ); 436 const juint secondary_offset = in_bytes(secondary_super_cache_offset()); 437 if (sup == k) { 438 return true; 439 } else if (off != secondary_offset) { 440 return false; 441 } else { 442 return search_secondary_supers(k); 443 } 444 } 445 bool search_secondary_supers(Klass* k) const; 446 447 // Find LCA in class hierarchy 448 Klass *LCA( Klass *k ); 449 450 // Check whether reflection/jni/jvm code is allowed to instantiate this class; 451 // if not, throw either an Error or an Exception. 452 virtual void check_valid_for_instantiation(bool throwError, TRAPS); 453 454 // array copying 455 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS); 456 457 // tells if the class should be initialized 458 virtual bool should_be_initialized() const { return false; } 459 // initializes the klass 460 virtual void initialize(TRAPS); 461 // lookup operation for MethodLookupCache 462 friend class MethodLookupCache; 463 virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const; 464 virtual Method* uncached_lookup_method(Symbol* name, Symbol* signature, MethodLookupMode mode) const; 465 public: 466 Method* lookup_method(Symbol* name, Symbol* signature) const { 467 return uncached_lookup_method(name, signature, normal); 468 } 469 470 // array class with specific rank 471 Klass* array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); } 472 473 // array class with this klass as element type 474 Klass* array_klass(TRAPS) { return array_klass_impl(false, THREAD); } 475 476 // These will return NULL instead of allocating on the heap: 477 // NB: these can block for a mutex, like other functions with TRAPS arg. 478 Klass* array_klass_or_null(int rank); 479 Klass* array_klass_or_null(); 480 481 virtual oop protection_domain() const = 0; 482 483 oop class_loader() const; 484 485 virtual oop klass_holder() const { return class_loader(); } 486 487 protected: 488 virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS); 489 virtual Klass* array_klass_impl(bool or_null, TRAPS); 490 491 public: 492 // CDS support - remove and restore oops from metadata. Oops are not shared. 493 virtual void remove_unshareable_info(); 494 virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS); 495 496 protected: 497 // computes the subtype relationship 498 virtual bool compute_is_subtype_of(Klass* k); 499 public: 500 // subclass accessor (here for convenience; undefined for non-klass objects) 501 virtual bool is_leaf_class() const { fatal("not a class"); return false; } 502 public: 503 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP 504 // These functions describe behavior for the oop not the KLASS. 505 506 // actual oop size of obj in memory 507 virtual int oop_size(oop obj) const = 0; 508 509 // Size of klass in word size. 510 virtual int size() const = 0; 511 #if INCLUDE_SERVICES 512 virtual void collect_statistics(KlassSizeStats *sz) const; 513 #endif 514 515 // Returns the Java name for a class (Resource allocated) 516 // For arrays, this returns the name of the element with a leading '['. 517 // For classes, this returns the name with the package separators 518 // turned into '.'s. 519 const char* external_name() const; 520 // Returns the name for a class (Resource allocated) as the class 521 // would appear in a signature. 522 // For arrays, this returns the name of the element with a leading '['. 523 // For classes, this returns the name with a leading 'L' and a trailing ';' 524 // and the package separators as '/'. 525 virtual const char* signature_name() const; 526 527 // garbage collection support 528 virtual void oop_follow_contents(oop obj) = 0; 529 virtual int oop_adjust_pointers(oop obj) = 0; 530 531 // Parallel Scavenge and Parallel Old 532 PARALLEL_GC_DECLS_PV 533 534 // type testing operations 535 protected: 536 virtual bool oop_is_instance_slow() const { return false; } 537 virtual bool oop_is_array_slow() const { return false; } 538 virtual bool oop_is_objArray_slow() const { return false; } 539 virtual bool oop_is_typeArray_slow() const { return false; } 540 public: 541 virtual bool oop_is_instanceClassLoader() const { return false; } 542 virtual bool oop_is_instanceMirror() const { return false; } 543 virtual bool oop_is_instanceRef() const { return false; } 544 545 // Fast non-virtual versions 546 #ifndef ASSERT 547 #define assert_same_query(xval, xcheck) xval 548 #else 549 private: 550 static bool assert_same_query(bool xval, bool xslow) { 551 assert(xval == xslow, "slow and fast queries agree"); 552 return xval; 553 } 554 public: 555 #endif 556 inline bool oop_is_instance() const { return assert_same_query( 557 layout_helper_is_instance(layout_helper()), 558 oop_is_instance_slow()); } 559 inline bool oop_is_array() const { return assert_same_query( 560 layout_helper_is_array(layout_helper()), 561 oop_is_array_slow()); } 562 inline bool oop_is_objArray() const { return assert_same_query( 563 layout_helper_is_objArray(layout_helper()), 564 oop_is_objArray_slow()); } 565 inline bool oop_is_typeArray() const { return assert_same_query( 566 layout_helper_is_typeArray(layout_helper()), 567 oop_is_typeArray_slow()); } 568 #undef assert_same_query 569 570 // Access flags 571 AccessFlags access_flags() const { return _access_flags; } 572 void set_access_flags(AccessFlags flags) { _access_flags = flags; } 573 574 bool is_public() const { return _access_flags.is_public(); } 575 bool is_final() const { return _access_flags.is_final(); } 576 bool is_interface() const { return _access_flags.is_interface(); } 577 bool is_abstract() const { return _access_flags.is_abstract(); } 578 bool is_super() const { return _access_flags.is_super(); } 579 bool is_synthetic() const { return _access_flags.is_synthetic(); } 580 void set_is_synthetic() { _access_flags.set_is_synthetic(); } 581 bool has_finalizer() const { return _access_flags.has_finalizer(); } 582 bool has_final_method() const { return _access_flags.has_final_method(); } 583 void set_has_finalizer() { _access_flags.set_has_finalizer(); } 584 void set_has_final_method() { _access_flags.set_has_final_method(); } 585 bool is_cloneable() const { return _access_flags.is_cloneable(); } 586 void set_is_cloneable() { _access_flags.set_is_cloneable(); } 587 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); } 588 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); } 589 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); } 590 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); } 591 592 // Biased locking support 593 // Note: the prototype header is always set up to be at least the 594 // prototype markOop. If biased locking is enabled it may further be 595 // biasable and have an epoch. 596 markOop prototype_header() const { return _prototype_header; } 597 // NOTE: once instances of this klass are floating around in the 598 // system, this header must only be updated at a safepoint. 599 // NOTE 2: currently we only ever set the prototype header to the 600 // biasable prototype for instanceKlasses. There is no technical 601 // reason why it could not be done for arrayKlasses aside from 602 // wanting to reduce the initial scope of this optimization. There 603 // are potential problems in setting the bias pattern for 604 // JVM-internal oops. 605 inline void set_prototype_header(markOop header); 606 static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); } 607 608 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; } 609 // Atomically increments biased_lock_revocation_count and returns updated value 610 int atomic_incr_biased_lock_revocation_count(); 611 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; } 612 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; } 613 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; } 614 615 TRACE_DEFINE_KLASS_METHODS; 616 617 EVTRACE_DEFINE_TRACKED_CLASS_METHODS; 618 619 // garbage collection support 620 virtual void oops_do(OopClosure* cl); 621 622 // Iff the class loader (or mirror for anonymous classes) is alive the 623 // Klass is considered alive. 624 // The is_alive closure passed in depends on the Garbage Collector used. 625 bool is_loader_alive(BoolObjectClosure* is_alive); 626 627 static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true); 628 static void clean_subklass_tree(BoolObjectClosure* is_alive) { 629 clean_weak_klass_links(is_alive, false /* clean_alive_klasses */); 630 } 631 632 // iterators 633 virtual int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) = 0; 634 virtual int oop_oop_iterate_v(oop obj, ExtendedOopClosure* blk) { 635 return oop_oop_iterate(obj, blk); 636 } 637 638 #if INCLUDE_ALL_GCS 639 // In case we don't have a specialized backward scanner use forward 640 // iteration. 641 virtual int oop_oop_iterate_backwards_v(oop obj, ExtendedOopClosure* blk) { 642 return oop_oop_iterate_v(obj, blk); 643 } 644 #endif // INCLUDE_ALL_GCS 645 646 // Iterates "blk" over all the oops in "obj" (of type "this") within "mr". 647 // (I don't see why the _m should be required, but without it the Solaris 648 // C++ gives warning messages about overridings of the "oop_oop_iterate" 649 // defined above "hiding" this virtual function. (DLD, 6/20/00)) */ 650 virtual int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) = 0; 651 virtual int oop_oop_iterate_v_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) { 652 return oop_oop_iterate_m(obj, blk, mr); 653 } 654 655 // Versions of the above iterators specialized to particular subtypes 656 // of OopClosure, to avoid closure virtual calls. 657 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 658 virtual int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk) { \ 659 /* Default implementation reverts to general version. */ \ 660 return oop_oop_iterate(obj, blk); \ 661 } \ 662 \ 663 /* Iterates "blk" over all the oops in "obj" (of type "this") within "mr". \ 664 (I don't see why the _m should be required, but without it the Solaris \ 665 C++ gives warning messages about overridings of the "oop_oop_iterate" \ 666 defined above "hiding" this virtual function. (DLD, 6/20/00)) */ \ 667 virtual int oop_oop_iterate##nv_suffix##_m(oop obj, \ 668 OopClosureType* blk, \ 669 MemRegion mr) { \ 670 return oop_oop_iterate_m(obj, blk, mr); \ 671 } 672 673 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL) 674 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL) 675 676 #if INCLUDE_ALL_GCS 677 #define Klass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ 678 virtual int oop_oop_iterate_backwards##nv_suffix(oop obj, \ 679 OopClosureType* blk) { \ 680 /* Default implementation reverts to general version. */ \ 681 return oop_oop_iterate_backwards_v(obj, blk); \ 682 } 683 684 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL) 685 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL) 686 #endif // INCLUDE_ALL_GCS 687 688 virtual void array_klasses_do(void f(Klass* k)) {} 689 690 // Return self, except for abstract classes with exactly 1 691 // implementor. Then return the 1 concrete implementation. 692 Klass *up_cast_abstract(); 693 694 // klass name 695 Symbol* name() const { return _name; } 696 void set_name(Symbol* n); 697 698 public: 699 // jvm support 700 virtual jint compute_modifier_flags(TRAPS) const; 701 702 // JVMTI support 703 virtual jint jvmti_class_status() const; 704 705 // Printing 706 virtual void print_on(outputStream* st) const; 707 708 virtual void oop_print_value_on(oop obj, outputStream* st); 709 virtual void oop_print_on (oop obj, outputStream* st); 710 711 virtual const char* internal_name() const = 0; 712 713 // Verification 714 virtual void verify_on(outputStream* st); 715 void verify() { verify_on(tty); } 716 717 #ifndef PRODUCT 718 bool verify_vtable_index(int index); 719 bool verify_itable_index(int index); 720 #endif 721 722 virtual void oop_verify_on(oop obj, outputStream* st); 723 724 static bool is_null(narrowKlass obj); 725 static bool is_null(Klass* obj); 726 727 // klass encoding for klass pointer in objects. 728 static narrowKlass encode_klass_not_null(Klass* v); 729 static narrowKlass encode_klass(Klass* v); 730 731 static Klass* decode_klass_not_null(narrowKlass v); 732 static Klass* decode_klass(narrowKlass v); 733 734 private: 735 // barriers used by klass_oop_store 736 void klass_update_barrier_set(oop v); 737 void klass_update_barrier_set_pre(oop* p, oop v); 738 }; 739 740 #endif // SHARE_VM_OOPS_KLASS_HPP