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 "gc/shared/specialized_oop_closures.hpp" 29 #include "memory/iterator.hpp" 30 #include "memory/memRegion.hpp" 31 #include "oops/metadata.hpp" 32 #include "oops/oop.hpp" 33 #include "trace/traceMacros.hpp" 34 #include "utilities/accessFlags.hpp" 35 #include "utilities/macros.hpp" 36 37 // 38 // A Klass provides: 39 // 1: language level class object (method dictionary etc.) 40 // 2: provide vm dispatch behavior for the object 41 // Both functions are combined into one C++ class. 42 43 // One reason for the oop/klass dichotomy in the implementation is 44 // that we don't want a C++ vtbl pointer in every object. Thus, 45 // normal oops don't have any virtual functions. Instead, they 46 // forward all "virtual" functions to their klass, which does have 47 // a vtbl and does the C++ dispatch depending on the object's 48 // actual type. (See oop.inline.hpp for some of the forwarding code.) 49 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"! 50 51 // Forward declarations. 52 template <class T> class Array; 53 template <class T> class GrowableArray; 54 class ClassLoaderData; 55 class klassVtable; 56 class ParCompactionManager; 57 class PSPromotionManager; 58 class KlassSizeStats; 59 class fieldDescriptor; 60 class vtableEntry; 61 62 class Klass : public Metadata { 63 friend class VMStructs; 64 friend class JVMCIVMStructs; 65 protected: 66 // note: put frequently-used fields together at start of klass structure 67 // for better cache behavior (may not make much of a difference but sure won't hurt) 68 enum { _primary_super_limit = 8 }; 69 70 // The "layout helper" is a combined descriptor of object layout. 71 // For klasses which are neither instance nor array, the value is zero. 72 // 73 // For instances, layout helper is a positive number, the instance size. 74 // This size is already passed through align_object_size and scaled to bytes. 75 // The low order bit is set if instances of this class cannot be 76 // allocated using the fastpath. 77 // 78 // For arrays, layout helper is a negative number, containing four 79 // distinct bytes, as follows: 80 // MSB:[tag, hsz, ebt, log2(esz)]:LSB 81 // where: 82 // tag is 0x80 if the elements are oops, 0xC0 if non-oops 83 // hsz is array header size in bytes (i.e., offset of first element) 84 // ebt is the BasicType of the elements 85 // esz is the element size in bytes 86 // This packed word is arranged so as to be quickly unpacked by the 87 // various fast paths that use the various subfields. 88 // 89 // The esz bits can be used directly by a SLL instruction, without masking. 90 // 91 // Note that the array-kind tag looks like 0x00 for instance klasses, 92 // since their length in bytes is always less than 24Mb. 93 // 94 // Final note: This comes first, immediately after C++ vtable, 95 // because it is frequently queried. 96 jint _layout_helper; 97 98 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers 99 // and _primary_supers all help make fast subtype checks. See big discussion 100 // in doc/server_compiler/checktype.txt 101 // 102 // Where to look to observe a supertype (it is &_secondary_super_cache for 103 // secondary supers, else is &_primary_supers[depth()]. 104 juint _super_check_offset; 105 106 // Class name. Instance classes: java/lang/String, etc. Array classes: [I, 107 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes. 108 Symbol* _name; 109 110 // Cache of last observed secondary supertype 111 Klass* _secondary_super_cache; 112 // Array of all secondary supertypes 113 Array<Klass*>* _secondary_supers; 114 // Ordered list of all primary supertypes 115 Klass* _primary_supers[_primary_super_limit]; 116 // Extra injectable types 117 InstanceKlass* _extra_super; 118 // java/lang/Class instance mirroring this class 119 oop _java_mirror; 120 // Superclass 121 Klass* _super; 122 // First subclass (NULL if none); _subklass->next_sibling() is next one 123 Klass* _subklass; 124 // Sibling link (or NULL); links all subklasses of a klass 125 Klass* _next_sibling; 126 127 // All klasses loaded by a class loader are chained through these links 128 Klass* _next_link; 129 130 // The VM's representation of the ClassLoader used to load this class. 131 // Provide access the corresponding instance java.lang.ClassLoader. 132 ClassLoaderData* _class_loader_data; 133 134 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers. 135 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here. 136 137 TRACE_DEFINE_TRACE_ID_FIELD; 138 139 // Biased locking implementation and statistics 140 // (the 64-bit chunk goes first, to avoid some fragmentation) 141 jlong _last_biased_lock_bulk_revocation_time; 142 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type 143 jint _biased_lock_revocation_count; 144 145 // vtable length 146 int _vtable_len; 147 148 // Remembered sets support for the oops in the klasses. 149 jbyte _modified_oops; // Card Table Equivalent (YC/CMS support) 150 jbyte _accumulated_modified_oops; // Mod Union Equivalent (CMS support) 151 152 private: 153 // This is an index into FileMapHeader::_classpath_entry_table[], to 154 // associate this class with the JAR file where it's loaded from during 155 // dump time. If a class is not loaded from the shared archive, this field is 156 // -1. 157 jshort _shared_class_path_index; 158 159 friend class SharedClassUtil; 160 protected: 161 162 // Constructor 163 Klass(); 164 165 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw(); 166 167 public: 168 enum DefaultsLookupMode { find_defaults, skip_defaults }; 169 enum OverpassLookupMode { find_overpass, skip_overpass }; 170 enum StaticLookupMode { find_static, skip_static }; 171 enum PrivateLookupMode { find_private, skip_private }; 172 173 bool is_klass() const volatile { return true; } 174 175 // super 176 Klass* super() const { return _super; } 177 void set_super(Klass* k) { _super = k; } 178 179 // initializes _super link, _primary_supers & _secondary_supers arrays 180 void initialize_supers(Klass* k, TRAPS); 181 void initialize_supers_impl1(Klass* k); 182 void initialize_supers_impl2(Klass* k); 183 184 // klass-specific helper for initializing _secondary_supers 185 virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots); 186 187 // java_super is the Java-level super type as specified by Class.getSuperClass. 188 virtual Klass* java_super() const { return NULL; } 189 190 juint super_check_offset() const { return _super_check_offset; } 191 void set_super_check_offset(juint o) { _super_check_offset = o; } 192 193 Klass* secondary_super_cache() const { return _secondary_super_cache; } 194 void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; } 195 196 Array<Klass*>* secondary_supers() const { return _secondary_supers; } 197 void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; } 198 199 // Return the element of the _super chain of the given depth. 200 // If there is no such element, return either NULL or this. 201 Klass* primary_super_of_depth(juint i) const { 202 assert(i < primary_super_limit(), "oob"); 203 Klass* super = _primary_supers[i]; 204 assert(super == NULL || super->super_depth() == i, "correct display"); 205 return super; 206 } 207 208 // Can this klass be a primary super? False for interfaces and arrays of 209 // interfaces. False also for arrays or classes with long super chains. 210 bool can_be_primary_super() const { 211 const juint secondary_offset = in_bytes(secondary_super_cache_offset()); 212 return super_check_offset() != secondary_offset; 213 } 214 virtual bool can_be_primary_super_slow() const; 215 216 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit]. 217 juint super_depth() const { 218 if (!can_be_primary_super()) { 219 return primary_super_limit(); 220 } else { 221 juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*); 222 assert(d < primary_super_limit(), "oob"); 223 assert(_primary_supers[d] == this, "proper init"); 224 return d; 225 } 226 } 227 228 // store an oop into a field of a Klass 229 void klass_oop_store(oop* p, oop v); 230 void klass_oop_store(volatile oop* p, oop v); 231 232 // java mirror 233 oop java_mirror() const { return _java_mirror; } 234 void set_java_mirror(oop m) { klass_oop_store(&_java_mirror, m); } 235 236 // modifier flags 237 jint modifier_flags() const { return _modifier_flags; } 238 void set_modifier_flags(jint flags) { _modifier_flags = flags; } 239 240 // size helper 241 int layout_helper() const { return _layout_helper; } 242 void set_layout_helper(int lh) { _layout_helper = lh; } 243 244 // Note: for instances layout_helper() may include padding. 245 // Use InstanceKlass::contains_field_offset to classify field offsets. 246 247 // sub/superklass links 248 Klass* subklass() const { return _subklass; } 249 Klass* next_sibling() const { return _next_sibling; } 250 InstanceKlass* superklass() const; 251 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list 252 253 void set_next_link(Klass* k) { _next_link = k; } 254 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader. 255 256 // patchable link to additional behaviors and interfaces 257 // Being used for prototying arrays with interfaces, can be move to ArrayKlass 258 // Lives here for now, just to keep macro asm simple 259 InstanceKlass* extra_super() const { return _extra_super; } 260 void set_extra_super(InstanceKlass* extra_super) { 261 assert(EnableExtraSuper || extra_super == NULL, "ExtraSuper not enabled"); 262 assert(extra_super == NULL || _extra_super == NULL, "One-shot"); 263 _extra_super = extra_super; 264 } 265 266 // class loader data 267 ClassLoaderData* class_loader_data() const { return _class_loader_data; } 268 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; } 269 270 // The Klasses are not placed in the Heap, so the Card Table or 271 // the Mod Union Table can't be used to mark when klasses have modified oops. 272 // The CT and MUT bits saves this information for the individual Klasses. 273 void record_modified_oops() { _modified_oops = 1; } 274 void clear_modified_oops() { _modified_oops = 0; } 275 bool has_modified_oops() { return _modified_oops == 1; } 276 277 void accumulate_modified_oops() { if (has_modified_oops()) _accumulated_modified_oops = 1; } 278 void clear_accumulated_modified_oops() { _accumulated_modified_oops = 0; } 279 bool has_accumulated_modified_oops() { return _accumulated_modified_oops == 1; } 280 281 int shared_classpath_index() const { 282 return _shared_class_path_index; 283 }; 284 285 void set_shared_classpath_index(int index) { 286 _shared_class_path_index = index; 287 }; 288 289 290 protected: // internal accessors 291 void set_subklass(Klass* s); 292 void set_next_sibling(Klass* s); 293 294 public: 295 296 // Compiler support 297 static ByteSize extra_super_offset() { return in_ByteSize(offset_of(Klass, _extra_super)); } 298 static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); } 299 static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); } 300 static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); } 301 static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); } 302 static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); } 303 static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); } 304 static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); } 305 static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); } 306 static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); } 307 308 // Unpacking layout_helper: 309 enum { 310 _lh_neutral_value = 0, // neutral non-array non-instance value 311 _lh_instance_slow_path_bit = 0x01, 312 _lh_log2_element_size_shift = BitsPerByte*0, 313 _lh_log2_element_size_mask = BitsPerLong-1, 314 _lh_element_type_shift = BitsPerByte*1, 315 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask 316 _lh_header_size_shift = BitsPerByte*2, 317 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask 318 319 // Additional array type bits 320 _lh_valuetype_bit = 29, // maybe objArray or valueArrayOop 321 322 _lh_array_tag_bits = 2, 323 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits, 324 _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30 325 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30 326 }; 327 328 static int layout_helper_size_in_bytes(jint lh) { 329 assert(lh > (jint)_lh_neutral_value, "must be instance"); 330 return (int) lh & ~_lh_instance_slow_path_bit; 331 } 332 static bool layout_helper_needs_slow_path(jint lh) { 333 assert(lh > (jint)_lh_neutral_value, "must be instance"); 334 return (lh & _lh_instance_slow_path_bit) != 0; 335 } 336 static bool layout_helper_is_instance(jint lh) { 337 return (jint)lh > (jint)_lh_neutral_value; 338 } 339 static bool layout_helper_is_array(jint lh) { 340 return (jint)lh < (jint)_lh_neutral_value; 341 } 342 static bool layout_helper_is_typeArray(jint lh) { 343 return _lh_array_tag_type_value == (lh >> _lh_array_tag_shift); 344 } 345 static bool layout_helper_is_objArray(jint lh) { 346 return _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift); 347 } 348 static bool layout_helper_is_valueArray(jint lh) { 349 return (lh >> _lh_valuetype_bit) & 1; 350 } 351 static int layout_helper_header_size(jint lh) { 352 assert(lh < (jint)_lh_neutral_value, "must be array"); 353 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask; 354 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity"); 355 return hsize; 356 } 357 static BasicType layout_helper_element_type(jint lh) { 358 assert(lh < (jint)_lh_neutral_value, "must be array"); 359 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask; 360 assert((btvalue >= T_BOOLEAN && btvalue <= T_OBJECT) || btvalue == T_VALUETYPE, "sanity"); 361 return (BasicType) btvalue; 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(l2esz <= LogBitsPerLong, 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 bool search_secondary_supers(Klass* k) const; 418 419 // Find LCA in class hierarchy 420 Klass *LCA( Klass *k ); 421 422 // Check whether reflection/jni/jvm code is allowed to instantiate this class; 423 // if not, throw either an Error or an Exception. 424 virtual void check_valid_for_instantiation(bool throwError, TRAPS); 425 426 // array copying 427 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS); 428 429 // tells if the class should be initialized 430 virtual bool should_be_initialized() const { return false; } 431 // initializes the klass 432 virtual void initialize(TRAPS); 433 // lookup operation for MethodLookupCache 434 friend class MethodLookupCache; 435 virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const; 436 virtual Method* uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const; 437 public: 438 Method* lookup_method(const Symbol* name, const Symbol* signature) const { 439 return uncached_lookup_method(name, signature, find_overpass); 440 } 441 442 // array class with specific rank 443 Klass* array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); } 444 445 // array class with this klass as element type 446 Klass* array_klass(TRAPS) { return array_klass_impl(false, THREAD); } 447 448 // These will return NULL instead of allocating on the heap: 449 // NB: these can block for a mutex, like other functions with TRAPS arg. 450 Klass* array_klass_or_null(int rank); 451 Klass* array_klass_or_null(); 452 453 virtual oop protection_domain() const = 0; 454 455 oop class_loader() const; 456 457 virtual oop klass_holder() const { return class_loader(); } 458 459 protected: 460 virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS); 461 virtual Klass* array_klass_impl(bool or_null, TRAPS); 462 463 void set_vtable_length(int len) { _vtable_len= len; } 464 465 vtableEntry* start_of_vtable() const; 466 public: 467 Method* method_at_vtable(int index); 468 469 static ByteSize vtable_start_offset(); 470 static ByteSize vtable_length_offset() { 471 return byte_offset_of(Klass, _vtable_len); 472 } 473 474 // CDS support - remove and restore oops from metadata. Oops are not shared. 475 virtual void remove_unshareable_info(); 476 virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS); 477 478 protected: 479 // computes the subtype relationship 480 virtual bool compute_is_subtype_of(Klass* k); 481 public: 482 // subclass accessor (here for convenience; undefined for non-klass objects) 483 virtual bool is_leaf_class() const { fatal("not a class"); return false; } 484 public: 485 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP 486 // These functions describe behavior for the oop not the KLASS. 487 488 // actual oop size of obj in memory 489 virtual int oop_size(oop obj) const = 0; 490 491 // Size of klass in word size. 492 virtual int size() const = 0; 493 #if INCLUDE_SERVICES 494 virtual void collect_statistics(KlassSizeStats *sz) const; 495 #endif 496 497 // Returns the Java name for a class (Resource allocated) 498 // For arrays, this returns the name of the element with a leading '['. 499 // For classes, this returns the name with the package separators 500 // turned into '.'s. 501 const char* external_name() const; 502 // Returns the name for a class (Resource allocated) as the class 503 // would appear in a signature. 504 // For arrays, this returns the name of the element with a leading '['. 505 // For classes, this returns the name with a leading 'L' and a trailing ';' 506 // and the package separators as '/'. 507 virtual const char* signature_name() const; 508 509 // type testing operations 510 #ifdef ASSERT 511 protected: 512 virtual bool is_instance_klass_slow() const { return false; } 513 virtual bool is_array_klass_slow() const { return false; } 514 virtual bool is_objArray_klass_slow() const { return false; } 515 virtual bool is_typeArray_klass_slow() const { return false; } 516 virtual bool is_valueArray_klass_slow() const { return false; } 517 #endif // ASSERT 518 // current implementation uses this method even in non debug builds 519 virtual bool is_value_slow() const { return false; } 520 public: 521 522 // Fast non-virtual versions 523 #ifndef ASSERT 524 #define assert_same_query(xval, xcheck) xval 525 #else 526 private: 527 static bool assert_same_query(bool xval, bool xslow) { 528 assert(xval == xslow, "slow and fast queries agree"); 529 return xval; 530 } 531 public: 532 #endif 533 inline bool is_instance_klass() const { return assert_same_query( 534 layout_helper_is_instance(layout_helper()), 535 is_instance_klass_slow()); } 536 inline bool is_array_klass() const { return assert_same_query( 537 layout_helper_is_array(layout_helper()), 538 is_array_klass_slow()); } 539 inline bool is_objArray_klass() const { return assert_same_query( 540 layout_helper_is_objArray(layout_helper()), 541 is_objArray_klass_slow()); } 542 inline bool is_typeArray_klass() const { return assert_same_query( 543 layout_helper_is_typeArray(layout_helper()), 544 is_typeArray_klass_slow()); } 545 inline bool is_value() const { return is_value_slow(); } //temporary hack 546 inline bool is_valueArray_klass() const { return assert_same_query( 547 layout_helper_is_valueArray(layout_helper()), 548 is_valueArray_klass_slow()); } 549 #undef assert_same_query 550 551 // Access flags 552 AccessFlags access_flags() const { return _access_flags; } 553 void set_access_flags(AccessFlags flags) { _access_flags = flags; } 554 555 bool is_public() const { return _access_flags.is_public(); } 556 bool is_final() const { return _access_flags.is_final(); } 557 bool is_interface() const { return _access_flags.is_interface(); } 558 bool is_abstract() const { return _access_flags.is_abstract(); } 559 bool is_super() const { return _access_flags.is_super(); } 560 bool is_synthetic() const { return _access_flags.is_synthetic(); } 561 void set_is_synthetic() { _access_flags.set_is_synthetic(); } 562 bool has_finalizer() const { return _access_flags.has_finalizer(); } 563 bool has_final_method() const { return _access_flags.has_final_method(); } 564 void set_has_finalizer() { _access_flags.set_has_finalizer(); } 565 void set_has_final_method() { _access_flags.set_has_final_method(); } 566 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); } 567 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); } 568 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); } 569 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); } 570 571 bool is_cloneable() const; 572 void set_is_cloneable(); 573 574 // Biased locking support 575 // Note: the prototype header is always set up to be at least the 576 // prototype markOop. If biased locking is enabled it may further be 577 // biasable and have an epoch. 578 markOop prototype_header() const { return _prototype_header; } 579 // NOTE: once instances of this klass are floating around in the 580 // system, this header must only be updated at a safepoint. 581 // NOTE 2: currently we only ever set the prototype header to the 582 // biasable prototype for instanceKlasses. There is no technical 583 // reason why it could not be done for arrayKlasses aside from 584 // wanting to reduce the initial scope of this optimization. There 585 // are potential problems in setting the bias pattern for 586 // JVM-internal oops. 587 inline void set_prototype_header(markOop header); 588 static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); } 589 590 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; } 591 // Atomically increments biased_lock_revocation_count and returns updated value 592 int atomic_incr_biased_lock_revocation_count(); 593 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; } 594 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; } 595 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; } 596 597 TRACE_DEFINE_TRACE_ID_METHODS; 598 599 // garbage collection support 600 void oops_do(OopClosure* cl); 601 602 // Iff the class loader (or mirror for anonymous classes) is alive the 603 // Klass is considered alive. 604 // The is_alive closure passed in depends on the Garbage Collector used. 605 bool is_loader_alive(BoolObjectClosure* is_alive); 606 607 static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true); 608 static void clean_subklass_tree(BoolObjectClosure* is_alive) { 609 clean_weak_klass_links(is_alive, false /* clean_alive_klasses */); 610 } 611 612 // GC specific object visitors 613 // 614 // Mark Sweep 615 virtual int oop_ms_adjust_pointers(oop obj) = 0; 616 #if INCLUDE_ALL_GCS 617 // Parallel Scavenge 618 virtual void oop_ps_push_contents( oop obj, PSPromotionManager* pm) = 0; 619 // Parallel Compact 620 virtual void oop_pc_follow_contents(oop obj, ParCompactionManager* cm) = 0; 621 virtual void oop_pc_update_pointers(oop obj, ParCompactionManager* cm) = 0; 622 #endif 623 624 // Iterators specialized to particular subtypes 625 // of ExtendedOopClosure, to avoid closure virtual calls. 626 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 627 virtual void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) = 0; \ 628 /* Iterates "closure" over all the oops in "obj" (of type "this") within "mr". */ \ 629 virtual void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) = 0; 630 631 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL) 632 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL) 633 634 #if INCLUDE_ALL_GCS 635 #define Klass_OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \ 636 virtual void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) = 0; 637 638 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS) 639 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS) 640 #endif // INCLUDE_ALL_GCS 641 642 virtual void array_klasses_do(void f(Klass* k)) {} 643 644 // Return self, except for abstract classes with exactly 1 645 // implementor. Then return the 1 concrete implementation. 646 Klass *up_cast_abstract(); 647 648 // klass name 649 Symbol* name() const { return _name; } 650 void set_name(Symbol* n); 651 652 public: 653 // jvm support 654 virtual jint compute_modifier_flags(TRAPS) const; 655 656 // JVMTI support 657 virtual jint jvmti_class_status() const; 658 659 // Printing 660 virtual void print_on(outputStream* st) const; 661 662 virtual void oop_print_value_on(oop obj, outputStream* st); 663 virtual void oop_print_on (oop obj, outputStream* st); 664 665 virtual const char* internal_name() const = 0; 666 667 // Verification 668 virtual void verify_on(outputStream* st); 669 void verify() { verify_on(tty); } 670 671 #ifndef PRODUCT 672 bool verify_vtable_index(int index); 673 bool verify_itable_index(int index); 674 #endif 675 676 virtual void oop_verify_on(oop obj, outputStream* st); 677 678 static bool is_null(narrowKlass obj); 679 static bool is_null(Klass* obj); 680 681 // klass encoding for klass pointer in objects. 682 static narrowKlass encode_klass_not_null(Klass* v); 683 static narrowKlass encode_klass(Klass* v); 684 685 static Klass* decode_klass_not_null(narrowKlass v); 686 static Klass* decode_klass(narrowKlass v); 687 688 private: 689 // barriers used by klass_oop_store 690 void klass_update_barrier_set(oop v); 691 void klass_update_barrier_set_pre(oop* p, oop v); 692 }; 693 694 // Helper to convert the oop iterate macro suffixes into bool values that can be used by template functions. 695 #define nvs_nv_to_bool true 696 #define nvs_v_to_bool false 697 #define nvs_to_bool(nv_suffix) nvs##nv_suffix##_to_bool 698 699 // Oop iteration macros for declarations. 700 // Used to generate declarations in the *Klass header files. 701 702 #define OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 703 void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure); \ 704 void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr); 705 706 #if INCLUDE_ALL_GCS 707 #define OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \ 708 void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure); 709 #endif // INCLUDE_ALL_GCS 710 711 712 // Oop iteration macros for definitions. 713 // Used to generate definitions in the *Klass.inline.hpp files. 714 715 #define OOP_OOP_ITERATE_DEFN(KlassType, OopClosureType, nv_suffix) \ 716 void KlassType::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \ 717 oop_oop_iterate<nvs_to_bool(nv_suffix)>(obj, closure); \ 718 } 719 720 #if INCLUDE_ALL_GCS 721 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix) \ 722 void KlassType::oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) { \ 723 oop_oop_iterate_reverse<nvs_to_bool(nv_suffix)>(obj, closure); \ 724 } 725 #else 726 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix) 727 #endif 728 729 #define OOP_OOP_ITERATE_DEFN_BOUNDED(KlassType, OopClosureType, nv_suffix) \ 730 void KlassType::oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) { \ 731 oop_oop_iterate_bounded<nvs_to_bool(nv_suffix)>(obj, closure, mr); \ 732 } 733 734 #endif // SHARE_VM_OOPS_KLASS_HPP