1 /* 2 * Copyright (c) 1997, 2022, 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_OOPS_KLASS_HPP 26 #define SHARE_OOPS_KLASS_HPP 27 28 #include "memory/iterator.hpp" 29 #include "memory/memRegion.hpp" 30 #include "oops/markWord.hpp" 31 #include "oops/metadata.hpp" 32 #include "oops/oop.hpp" 33 #include "oops/oopHandle.hpp" 34 #include "utilities/accessFlags.hpp" 35 #include "utilities/macros.hpp" 36 #if INCLUDE_JFR 37 #include "jfr/support/jfrTraceIdExtension.hpp" 38 #endif 39 40 // Klass Kinds for all subclasses of Klass 41 enum KlassKind { 42 InstanceKlassKind, 43 InstanceRefKlassKind, 44 InstanceMirrorKlassKind, 45 InstanceClassLoaderKlassKind, 46 TypeArrayKlassKind, 47 ObjArrayKlassKind 48 }; 49 50 const uint KLASS_KIND_COUNT = ObjArrayKlassKind + 1; 51 52 // 53 // A Klass provides: 54 // 1: language level class object (method dictionary etc.) 55 // 2: provide vm dispatch behavior for the object 56 // Both functions are combined into one C++ class. 57 58 // One reason for the oop/klass dichotomy in the implementation is 59 // that we don't want a C++ vtbl pointer in every object. Thus, 60 // normal oops don't have any virtual functions. Instead, they 61 // forward all "virtual" functions to their klass, which does have 62 // a vtbl and does the C++ dispatch depending on the object's 63 // actual type. (See oop.inline.hpp for some of the forwarding code.) 64 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"! 65 66 // Forward declarations. 67 template <class T> class Array; 68 template <class T> class GrowableArray; 69 class ClassLoaderData; 70 class fieldDescriptor; 71 class klassVtable; 72 class ModuleEntry; 73 class PackageEntry; 74 class ParCompactionManager; 75 class PSPromotionManager; 76 class vtableEntry; 77 78 class Klass : public Metadata { 79 friend class VMStructs; 80 friend class JVMCIVMStructs; 81 protected: 82 // If you add a new field that points to any metaspace object, you 83 // must add this field to Klass::metaspace_pointers_do(). 84 85 // note: put frequently-used fields together at start of klass structure 86 // for better cache behavior (may not make much of a difference but sure won't hurt) 87 enum { _primary_super_limit = 8 }; 88 89 // The "layout helper" is a combined descriptor of object layout. 90 // For klasses which are neither instance nor array, the value is zero. 91 // 92 // For instances, layout helper is a positive number, the instance size. 93 // This size is already passed through align_object_size and scaled to bytes. 94 // The low order bit is set if instances of this class cannot be 95 // allocated using the fastpath. 96 // 97 // For arrays, layout helper is a negative number, containing four 98 // distinct bytes, as follows: 99 // MSB:[tag, hsz, ebt, log2(esz)]:LSB 100 // where: 101 // tag is 0x80 if the elements are oops, 0xC0 if non-oops 102 // hsz is array header size in bytes (i.e., offset of first element) 103 // ebt is the BasicType of the elements 104 // esz is the element size in bytes 105 // This packed word is arranged so as to be quickly unpacked by the 106 // various fast paths that use the various subfields. 107 // 108 // The esz bits can be used directly by a SLL instruction, without masking. 109 // 110 // Note that the array-kind tag looks like 0x00 for instance klasses, 111 // since their length in bytes is always less than 24Mb. 112 // 113 // Final note: This comes first, immediately after C++ vtable, 114 // because it is frequently queried. 115 jint _layout_helper; 116 117 // Klass kind used to resolve the runtime type of the instance. 118 // - Used to implement devirtualized oop closure dispatching. 119 // - Various type checking in the JVM 120 const KlassKind _kind; 121 122 // Processed access flags, for use by Class.getModifiers. 123 jint _modifier_flags; 124 125 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers 126 // and _primary_supers all help make fast subtype checks. See big discussion 127 // in doc/server_compiler/checktype.txt 128 // 129 // Where to look to observe a supertype (it is &_secondary_super_cache for 130 // secondary supers, else is &_primary_supers[depth()]. 131 juint _super_check_offset; 132 133 // Class name. Instance classes: java/lang/String, etc. Array classes: [I, 134 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes. 135 Symbol* _name; 136 137 // Cache of last observed secondary supertype 138 Klass* _secondary_super_cache; 139 // Array of all secondary supertypes 140 Array<Klass*>* _secondary_supers; 141 // Ordered list of all primary supertypes 142 Klass* _primary_supers[_primary_super_limit]; 143 // java/lang/Class instance mirroring this class 144 OopHandle _java_mirror; 145 // Superclass 146 Klass* _super; 147 // First subclass (NULL if none); _subklass->next_sibling() is next one 148 Klass* volatile _subklass; 149 // Sibling link (or NULL); links all subklasses of a klass 150 Klass* volatile _next_sibling; 151 152 // All klasses loaded by a class loader are chained through these links 153 Klass* _next_link; 154 155 // The VM's representation of the ClassLoader used to load this class. 156 // Provide access the corresponding instance java.lang.ClassLoader. 157 ClassLoaderData* _class_loader_data; 158 159 int _vtable_len; // vtable length. This field may be read very often when we 160 // have lots of itable dispatches (e.g., lambdas and streams). 161 // Keep it away from the beginning of a Klass to avoid cacheline 162 // contention that may happen when a nearby object is modified. 163 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here. 164 165 JFR_ONLY(DEFINE_TRACE_ID_FIELD;) 166 167 private: 168 // This is an index into FileMapHeader::_shared_path_table[], to 169 // associate this class with the JAR file where it's loaded from during 170 // dump time. If a class is not loaded from the shared archive, this field is 171 // -1. 172 jshort _shared_class_path_index; 173 174 #if INCLUDE_CDS 175 // Flags of the current shared class. 176 u2 _shared_class_flags; 177 enum { 178 _archived_lambda_proxy_is_available = 1 << 1, 179 _has_value_based_class_annotation = 1 << 2, 180 _verified_at_dump_time = 1 << 3, 181 _has_archived_enum_objs = 1 << 4, 182 _regenerated = 1 << 5 183 }; 184 #endif 185 186 CDS_JAVA_HEAP_ONLY(int _archived_mirror_index;) 187 188 protected: 189 190 // Constructor 191 Klass(KlassKind kind); 192 Klass() : _kind(KlassKind(-1)) { assert(DumpSharedSpaces || UseSharedSpaces, "only for cds"); } 193 194 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw(); 195 196 public: 197 int kind() { return _kind; } 198 199 enum class DefaultsLookupMode { find, skip }; 200 enum class OverpassLookupMode { find, skip }; 201 enum class StaticLookupMode { find, skip }; 202 enum class PrivateLookupMode { find, skip }; 203 204 virtual bool is_klass() const { return true; } 205 206 // super() cannot be InstanceKlass* -- Java arrays are covariant, and _super is used 207 // to implement that. NB: the _super of "[Ljava/lang/Integer;" is "[Ljava/lang/Number;" 208 // If this is not what your code expects, you're probably looking for Klass::java_super(). 209 Klass* super() const { return _super; } 210 void set_super(Klass* k) { _super = k; } 211 212 // initializes _super link, _primary_supers & _secondary_supers arrays 213 void initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS); 214 215 // klass-specific helper for initializing _secondary_supers 216 virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots, 217 Array<InstanceKlass*>* transitive_interfaces); 218 219 // java_super is the Java-level super type as specified by Class.getSuperClass. 220 virtual InstanceKlass* java_super() const { return NULL; } 221 222 juint super_check_offset() const { return _super_check_offset; } 223 void set_super_check_offset(juint o) { _super_check_offset = o; } 224 225 Klass* secondary_super_cache() const { return _secondary_super_cache; } 226 void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; } 227 228 Array<Klass*>* secondary_supers() const { return _secondary_supers; } 229 void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; } 230 231 // Return the element of the _super chain of the given depth. 232 // If there is no such element, return either NULL or this. 233 Klass* primary_super_of_depth(juint i) const { 234 assert(i < primary_super_limit(), "oob"); 235 Klass* super = _primary_supers[i]; 236 assert(super == NULL || super->super_depth() == i, "correct display"); 237 return super; 238 } 239 240 // Can this klass be a primary super? False for interfaces and arrays of 241 // interfaces. False also for arrays or classes with long super chains. 242 bool can_be_primary_super() const { 243 const juint secondary_offset = in_bytes(secondary_super_cache_offset()); 244 return super_check_offset() != secondary_offset; 245 } 246 virtual bool can_be_primary_super_slow() const; 247 248 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit]. 249 juint super_depth() const { 250 if (!can_be_primary_super()) { 251 return primary_super_limit(); 252 } else { 253 juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*); 254 assert(d < primary_super_limit(), "oob"); 255 assert(_primary_supers[d] == this, "proper init"); 256 return d; 257 } 258 } 259 260 // java mirror 261 oop java_mirror() const; 262 oop java_mirror_no_keepalive() const; 263 void set_java_mirror(Handle m); 264 265 oop archived_java_mirror() NOT_CDS_JAVA_HEAP_RETURN_(NULL); 266 void set_archived_java_mirror(oop m) NOT_CDS_JAVA_HEAP_RETURN; 267 268 // Temporary mirror switch used by RedefineClasses 269 void replace_java_mirror(oop mirror); 270 271 // Set java mirror OopHandle to NULL for CDS 272 // This leaves the OopHandle in the CLD, but that's ok, you can't release them. 273 void clear_java_mirror_handle() { _java_mirror = OopHandle(); } 274 275 // modifier flags 276 jint modifier_flags() const { return _modifier_flags; } 277 void set_modifier_flags(jint flags) { _modifier_flags = flags; } 278 279 // size helper 280 int layout_helper() const { return _layout_helper; } 281 void set_layout_helper(int lh) { _layout_helper = lh; } 282 283 // Note: for instances layout_helper() may include padding. 284 // Use InstanceKlass::contains_field_offset to classify field offsets. 285 286 // sub/superklass links 287 Klass* subklass(bool log = false) const; 288 Klass* next_sibling(bool log = false) const; 289 290 InstanceKlass* superklass() const; 291 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list 292 293 void set_next_link(Klass* k) { _next_link = k; } 294 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader. 295 Klass** next_link_addr() { return &_next_link; } 296 297 // class loader data 298 ClassLoaderData* class_loader_data() const { return _class_loader_data; } 299 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; } 300 301 int shared_classpath_index() const { 302 return _shared_class_path_index; 303 }; 304 305 void set_shared_classpath_index(int index) { 306 _shared_class_path_index = index; 307 }; 308 309 bool has_archived_mirror_index() const { 310 CDS_JAVA_HEAP_ONLY(return _archived_mirror_index >= 0;) 311 NOT_CDS_JAVA_HEAP(return false); 312 } 313 314 void clear_archived_mirror_index() NOT_CDS_JAVA_HEAP_RETURN; 315 316 void set_lambda_proxy_is_available() { 317 CDS_ONLY(_shared_class_flags |= _archived_lambda_proxy_is_available;) 318 } 319 void clear_lambda_proxy_is_available() { 320 CDS_ONLY(_shared_class_flags &= ~_archived_lambda_proxy_is_available;) 321 } 322 bool lambda_proxy_is_available() const { 323 CDS_ONLY(return (_shared_class_flags & _archived_lambda_proxy_is_available) != 0;) 324 NOT_CDS(return false;) 325 } 326 327 void set_has_value_based_class_annotation() { 328 CDS_ONLY(_shared_class_flags |= _has_value_based_class_annotation;) 329 } 330 void clear_has_value_based_class_annotation() { 331 CDS_ONLY(_shared_class_flags &= ~_has_value_based_class_annotation;) 332 } 333 bool has_value_based_class_annotation() const { 334 CDS_ONLY(return (_shared_class_flags & _has_value_based_class_annotation) != 0;) 335 NOT_CDS(return false;) 336 } 337 338 void set_verified_at_dump_time() { 339 CDS_ONLY(_shared_class_flags |= _verified_at_dump_time;) 340 } 341 bool verified_at_dump_time() const { 342 CDS_ONLY(return (_shared_class_flags & _verified_at_dump_time) != 0;) 343 NOT_CDS(return false;) 344 } 345 346 void set_has_archived_enum_objs() { 347 CDS_ONLY(_shared_class_flags |= _has_archived_enum_objs;) 348 } 349 bool has_archived_enum_objs() const { 350 CDS_ONLY(return (_shared_class_flags & _has_archived_enum_objs) != 0;) 351 NOT_CDS(return false;) 352 } 353 354 void set_regenerated() { 355 CDS_ONLY(_shared_class_flags |= _regenerated;) 356 } 357 bool is_regenerated() const { 358 CDS_ONLY(return (_shared_class_flags & _regenerated) != 0;) 359 NOT_CDS(return false;) 360 } 361 362 // Obtain the module or package for this class 363 virtual ModuleEntry* module() const = 0; 364 virtual PackageEntry* package() const = 0; 365 366 protected: // internal accessors 367 void set_subklass(Klass* s); 368 void set_next_sibling(Klass* s); 369 370 public: 371 372 // Compiler support 373 static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); } 374 static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); } 375 static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); } 376 static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); } 377 static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); } 378 static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); } 379 static ByteSize class_loader_data_offset() { return in_ByteSize(offset_of(Klass, _class_loader_data)); } 380 static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); } 381 static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); } 382 static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); } 383 384 // Unpacking layout_helper: 385 static const int _lh_neutral_value = 0; // neutral non-array non-instance value 386 static const int _lh_instance_slow_path_bit = 0x01; 387 static const int _lh_log2_element_size_shift = BitsPerByte*0; 388 static const int _lh_log2_element_size_mask = BitsPerLong-1; 389 static const int _lh_element_type_shift = BitsPerByte*1; 390 static const int _lh_element_type_mask = right_n_bits(BitsPerByte); // shifted mask 391 static const int _lh_header_size_shift = BitsPerByte*2; 392 static const int _lh_header_size_mask = right_n_bits(BitsPerByte); // shifted mask 393 static const int _lh_array_tag_bits = 2; 394 static const int _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits; 395 static const int _lh_array_tag_obj_value = ~0x01; // 0x80000000 >> 30 396 397 static const unsigned int _lh_array_tag_type_value = 0Xffffffff; // ~0x00, // 0xC0000000 >> 30 398 399 static int layout_helper_size_in_bytes(jint lh) { 400 assert(lh > (jint)_lh_neutral_value, "must be instance"); 401 return (int) lh & ~_lh_instance_slow_path_bit; 402 } 403 static bool layout_helper_needs_slow_path(jint lh) { 404 assert(lh > (jint)_lh_neutral_value, "must be instance"); 405 return (lh & _lh_instance_slow_path_bit) != 0; 406 } 407 static bool layout_helper_is_instance(jint lh) { 408 return (jint)lh > (jint)_lh_neutral_value; 409 } 410 static bool layout_helper_is_array(jint lh) { 411 return (jint)lh < (jint)_lh_neutral_value; 412 } 413 static bool layout_helper_is_typeArray(jint lh) { 414 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift); 415 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift); 416 } 417 static bool layout_helper_is_objArray(jint lh) { 418 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift); 419 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift); 420 } 421 static int layout_helper_header_size(jint lh) { 422 assert(lh < (jint)_lh_neutral_value, "must be array"); 423 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask; 424 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity"); 425 return hsize; 426 } 427 static BasicType layout_helper_element_type(jint lh) { 428 assert(lh < (jint)_lh_neutral_value, "must be array"); 429 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask; 430 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity"); 431 return (BasicType) btvalue; 432 } 433 434 // Want a pattern to quickly diff against layout header in register 435 // find something less clever! 436 static int layout_helper_boolean_diffbit() { 437 jint zlh = array_layout_helper(T_BOOLEAN); 438 jint blh = array_layout_helper(T_BYTE); 439 assert(zlh != blh, "array layout helpers must differ"); 440 int diffbit = 1; 441 while ((diffbit & (zlh ^ blh)) == 0 && (diffbit & zlh) == 0) { 442 diffbit <<= 1; 443 assert(diffbit != 0, "make sure T_BOOLEAN has a different bit than T_BYTE"); 444 } 445 return diffbit; 446 } 447 448 static int layout_helper_log2_element_size(jint lh) { 449 assert(lh < (jint)_lh_neutral_value, "must be array"); 450 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask; 451 assert(l2esz <= LogBytesPerLong, 452 "sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh); 453 return l2esz; 454 } 455 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) { 456 return (tag << _lh_array_tag_shift) 457 | (hsize << _lh_header_size_shift) 458 | ((int)etype << _lh_element_type_shift) 459 | (log2_esize << _lh_log2_element_size_shift); 460 } 461 static jint instance_layout_helper(jint size, bool slow_path_flag) { 462 return (size << LogBytesPerWord) 463 | (slow_path_flag ? _lh_instance_slow_path_bit : 0); 464 } 465 static int layout_helper_to_size_helper(jint lh) { 466 assert(lh > (jint)_lh_neutral_value, "must be instance"); 467 // Note that the following expression discards _lh_instance_slow_path_bit. 468 return lh >> LogBytesPerWord; 469 } 470 // Out-of-line version computes everything based on the etype: 471 static jint array_layout_helper(BasicType etype); 472 473 // What is the maximum number of primary superclasses any klass can have? 474 static juint primary_super_limit() { return _primary_super_limit; } 475 476 // vtables 477 klassVtable vtable() const; 478 int vtable_length() const { return _vtable_len; } 479 480 // subclass check 481 bool is_subclass_of(const Klass* k) const; 482 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it 483 bool is_subtype_of(Klass* k) const { 484 juint off = k->super_check_offset(); 485 Klass* sup = *(Klass**)( (address)this + off ); 486 const juint secondary_offset = in_bytes(secondary_super_cache_offset()); 487 if (sup == k) { 488 return true; 489 } else if (off != secondary_offset) { 490 return false; 491 } else { 492 return search_secondary_supers(k); 493 } 494 } 495 496 bool search_secondary_supers(Klass* k) const; 497 498 // Find LCA in class hierarchy 499 Klass *LCA( Klass *k ); 500 501 // Check whether reflection/jni/jvm code is allowed to instantiate this class; 502 // if not, throw either an Error or an Exception. 503 virtual void check_valid_for_instantiation(bool throwError, TRAPS); 504 505 // array copying 506 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS); 507 508 // tells if the class should be initialized 509 virtual bool should_be_initialized() const { return false; } 510 // initializes the klass 511 virtual void initialize(TRAPS); 512 virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const; 513 virtual Method* uncached_lookup_method(const Symbol* name, const Symbol* signature, 514 OverpassLookupMode overpass_mode, 515 PrivateLookupMode = PrivateLookupMode::find) const; 516 public: 517 Method* lookup_method(const Symbol* name, const Symbol* signature) const { 518 return uncached_lookup_method(name, signature, OverpassLookupMode::find); 519 } 520 521 // array class with specific rank 522 virtual Klass* array_klass(int rank, TRAPS) = 0; 523 524 // array class with this klass as element type 525 virtual Klass* array_klass(TRAPS) = 0; 526 527 // These will return NULL instead of allocating on the heap: 528 virtual Klass* array_klass_or_null(int rank) = 0; 529 virtual Klass* array_klass_or_null() = 0; 530 531 virtual oop protection_domain() const = 0; 532 533 oop class_loader() const; 534 535 inline oop klass_holder() const; 536 537 protected: 538 539 // Error handling when length > max_length or length < 0 540 static void check_array_allocation_length(int length, int max_length, TRAPS); 541 542 void set_vtable_length(int len) { _vtable_len= len; } 543 544 vtableEntry* start_of_vtable() const; 545 void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS); 546 public: 547 Method* method_at_vtable(int index); 548 549 static ByteSize vtable_start_offset(); 550 static ByteSize vtable_length_offset() { 551 return byte_offset_of(Klass, _vtable_len); 552 } 553 554 // CDS support - remove and restore oops from metadata. Oops are not shared. 555 virtual void remove_unshareable_info(); 556 virtual void remove_java_mirror(); 557 558 bool is_unshareable_info_restored() const { 559 assert(is_shared(), "use this for shared classes only"); 560 if (has_archived_mirror_index()) { 561 // _java_mirror is not a valid OopHandle but rather an encoded reference in the shared heap 562 return false; 563 } else if (_java_mirror.ptr_raw() == NULL) { 564 return false; 565 } else { 566 return true; 567 } 568 } 569 570 public: 571 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP 572 // These functions describe behavior for the oop not the KLASS. 573 574 // actual oop size of obj in memory in word size. 575 virtual size_t oop_size(oop obj) const = 0; 576 577 // Size of klass in word size. 578 virtual int size() const = 0; 579 580 // Returns the Java name for a class (Resource allocated) 581 // For arrays, this returns the name of the element with a leading '['. 582 // For classes, this returns the name with the package separators 583 // turned into '.'s. 584 const char* external_name() const; 585 // Returns the name for a class (Resource allocated) as the class 586 // would appear in a signature. 587 // For arrays, this returns the name of the element with a leading '['. 588 // For classes, this returns the name with a leading 'L' and a trailing ';' 589 // and the package separators as '/'. 590 virtual const char* signature_name() const; 591 592 const char* joint_in_module_of_loader(const Klass* class2, bool include_parent_loader = false) const; 593 const char* class_in_module_of_loader(bool use_are = false, bool include_parent_loader = false) const; 594 595 // Returns "interface", "abstract class" or "class". 596 const char* external_kind() const; 597 598 // type testing operations 599 #ifdef ASSERT 600 protected: 601 virtual bool is_instance_klass_slow() const { return false; } 602 virtual bool is_array_klass_slow() const { return false; } 603 virtual bool is_objArray_klass_slow() const { return false; } 604 virtual bool is_typeArray_klass_slow() const { return false; } 605 #endif // ASSERT 606 public: 607 608 // Fast non-virtual versions 609 #ifndef ASSERT 610 #define assert_same_query(xval, xcheck) xval 611 #else 612 private: 613 static bool assert_same_query(bool xval, bool xslow) { 614 assert(xval == xslow, "slow and fast queries agree"); 615 return xval; 616 } 617 public: 618 #endif 619 620 bool is_instance_klass() const { return assert_same_query(_kind <= InstanceClassLoaderKlassKind, is_instance_klass_slow()); } 621 // Other is anything that is not one of the more specialized kinds of InstanceKlass. 622 bool is_other_instance_klass() const { return _kind == InstanceKlassKind; } 623 bool is_reference_instance_klass() const { return _kind == InstanceRefKlassKind; } 624 bool is_mirror_instance_klass() const { return _kind == InstanceMirrorKlassKind; } 625 bool is_class_loader_instance_klass() const { return _kind == InstanceClassLoaderKlassKind; } 626 bool is_array_klass() const { return assert_same_query( _kind >= TypeArrayKlassKind, is_array_klass_slow()); } 627 bool is_objArray_klass() const { return assert_same_query( _kind == ObjArrayKlassKind, is_objArray_klass_slow()); } 628 bool is_typeArray_klass() const { return assert_same_query( _kind == TypeArrayKlassKind, is_typeArray_klass_slow()); } 629 #undef assert_same_query 630 631 // Access flags 632 AccessFlags access_flags() const { return _access_flags; } 633 void set_access_flags(AccessFlags flags) { _access_flags = flags; } 634 635 bool is_public() const { return _access_flags.is_public(); } 636 bool is_final() const { return _access_flags.is_final(); } 637 bool is_interface() const { return _access_flags.is_interface(); } 638 bool is_abstract() const { return _access_flags.is_abstract(); } 639 bool is_super() const { return _access_flags.is_super(); } 640 bool is_synthetic() const { return _access_flags.is_synthetic(); } 641 void set_is_synthetic() { _access_flags.set_is_synthetic(); } 642 bool has_finalizer() const { return _access_flags.has_finalizer(); } 643 bool has_final_method() const { return _access_flags.has_final_method(); } 644 void set_has_finalizer() { _access_flags.set_has_finalizer(); } 645 void set_has_final_method() { _access_flags.set_has_final_method(); } 646 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); } 647 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); } 648 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); } 649 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); } 650 bool is_shared() const { return access_flags().is_shared_class(); } // shadows MetaspaceObj::is_shared)() 651 void set_is_shared() { _access_flags.set_is_shared_class(); } 652 bool is_hidden() const { return access_flags().is_hidden_class(); } 653 void set_is_hidden() { _access_flags.set_is_hidden_class(); } 654 bool is_value_based() { return _access_flags.is_value_based_class(); } 655 void set_is_value_based() { _access_flags.set_is_value_based_class(); } 656 657 inline bool is_non_strong_hidden() const; 658 659 bool is_cloneable() const; 660 void set_is_cloneable(); 661 662 JFR_ONLY(DEFINE_TRACE_ID_METHODS;) 663 664 virtual void metaspace_pointers_do(MetaspaceClosure* iter); 665 virtual MetaspaceObj::Type type() const { return ClassType; } 666 667 inline bool is_loader_alive() const; 668 669 void clean_subklass(); 670 671 static void clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses = true); 672 static void clean_subklass_tree() { 673 clean_weak_klass_links(/*unloading_occurred*/ true , /* clean_alive_klasses */ false); 674 } 675 676 // Return self, except for abstract classes with exactly 1 677 // implementor. Then return the 1 concrete implementation. 678 Klass *up_cast_abstract(); 679 680 // klass name 681 Symbol* name() const { return _name; } 682 void set_name(Symbol* n); 683 684 virtual void release_C_heap_structures(bool release_constant_pool = true); 685 686 public: 687 virtual jint compute_modifier_flags() const = 0; 688 689 // JVMTI support 690 virtual jint jvmti_class_status() const; 691 692 // Printing 693 virtual void print_on(outputStream* st) const; 694 695 virtual void oop_print_value_on(oop obj, outputStream* st); 696 virtual void oop_print_on (oop obj, outputStream* st); 697 698 virtual const char* internal_name() const = 0; 699 700 // Verification 701 virtual void verify_on(outputStream* st); 702 void verify() { verify_on(tty); } 703 704 #ifndef PRODUCT 705 bool verify_vtable_index(int index); 706 #endif 707 708 virtual void oop_verify_on(oop obj, outputStream* st); 709 710 // for error reporting 711 static bool is_valid(Klass* k); 712 }; 713 714 #endif // SHARE_OOPS_KLASS_HPP