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 // java/lang/Class instance mirroring this class 117 oop _java_mirror; 118 // Superclass 119 Klass* _super; 120 // First subclass (NULL if none); _subklass->next_sibling() is next one 121 Klass* _subklass; 122 // Sibling link (or NULL); links all subklasses of a klass 123 Klass* _next_sibling; 124 125 // All klasses loaded by a class loader are chained through these links 126 Klass* _next_link; 127 128 // The VM's representation of the ClassLoader used to load this class. 129 // Provide access the corresponding instance java.lang.ClassLoader. 130 ClassLoaderData* _class_loader_data; 131 132 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers. 133 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here. 134 135 TRACE_DEFINE_TRACE_ID_FIELD; 136 137 // Biased locking implementation and statistics 138 // (the 64-bit chunk goes first, to avoid some fragmentation) 139 jlong _last_biased_lock_bulk_revocation_time; 140 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type 141 jint _biased_lock_revocation_count; 142 143 // vtable length 144 int _vtable_len; 145 146 // Remembered sets support for the oops in the klasses. 147 jbyte _modified_oops; // Card Table Equivalent (YC/CMS support) 148 jbyte _accumulated_modified_oops; // Mod Union Equivalent (CMS support) 149 150 private: 151 // This is an index into FileMapHeader::_classpath_entry_table[], to 152 // associate this class with the JAR file where it's loaded from during 153 // dump time. If a class is not loaded from the shared archive, this field is 154 // -1. 155 jshort _shared_class_path_index; 156 157 friend class SharedClassUtil; 158 protected: 159 160 // Constructor 161 Klass(); 162 163 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw(); 164 165 public: 166 enum DefaultsLookupMode { find_defaults, skip_defaults }; 167 enum OverpassLookupMode { find_overpass, skip_overpass }; 168 enum StaticLookupMode { find_static, skip_static }; 169 enum PrivateLookupMode { find_private, skip_private }; 170 171 bool is_klass() const volatile { return true; } 172 173 // super 174 Klass* super() const { return _super; } 175 void set_super(Klass* k) { _super = k; } 176 177 // initializes _super link, _primary_supers & _secondary_supers arrays 178 void initialize_supers(Klass* k, TRAPS); 179 void initialize_supers_impl1(Klass* k); 180 void initialize_supers_impl2(Klass* k); 181 182 // klass-specific helper for initializing _secondary_supers 183 virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots); 184 185 // java_super is the Java-level super type as specified by Class.getSuperClass. 186 virtual Klass* java_super() const { return NULL; } 187 188 juint super_check_offset() const { return _super_check_offset; } 189 void set_super_check_offset(juint o) { _super_check_offset = o; } 190 191 Klass* secondary_super_cache() const { return _secondary_super_cache; } 192 void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; } 193 194 Array<Klass*>* secondary_supers() const { return _secondary_supers; } 195 void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; } 196 197 // Return the element of the _super chain of the given depth. 198 // If there is no such element, return either NULL or this. 199 Klass* primary_super_of_depth(juint i) const { 200 assert(i < primary_super_limit(), "oob"); 201 Klass* super = _primary_supers[i]; 202 assert(super == NULL || super->super_depth() == i, "correct display"); 203 return super; 204 } 205 206 // Can this klass be a primary super? False for interfaces and arrays of 207 // interfaces. False also for arrays or classes with long super chains. 208 bool can_be_primary_super() const { 209 const juint secondary_offset = in_bytes(secondary_super_cache_offset()); 210 return super_check_offset() != secondary_offset; 211 } 212 virtual bool can_be_primary_super_slow() const; 213 214 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit]. 215 juint super_depth() const { 216 if (!can_be_primary_super()) { 217 return primary_super_limit(); 218 } else { 219 juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*); 220 assert(d < primary_super_limit(), "oob"); 221 assert(_primary_supers[d] == this, "proper init"); 222 return d; 223 } 224 } 225 226 // store an oop into a field of a Klass 227 void klass_oop_store(oop* p, oop v); 228 void klass_oop_store(volatile oop* p, oop v); 229 230 // java mirror 231 oop java_mirror() const { return _java_mirror; } 232 void set_java_mirror(oop m) { klass_oop_store(&_java_mirror, m); } 233 234 // modifier flags 235 jint modifier_flags() const { return _modifier_flags; } 236 void set_modifier_flags(jint flags) { _modifier_flags = flags; } 237 238 // size helper 239 int layout_helper() const { return _layout_helper; } 240 void set_layout_helper(int lh) { _layout_helper = lh; } 241 242 // Note: for instances layout_helper() may include padding. 243 // Use InstanceKlass::contains_field_offset to classify field offsets. 244 245 // sub/superklass links 246 Klass* subklass() const { return _subklass; } 247 Klass* next_sibling() const { return _next_sibling; } 248 InstanceKlass* superklass() const; 249 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list 250 251 void set_next_link(Klass* k) { _next_link = k; } 252 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader. 253 254 // class loader data 255 ClassLoaderData* class_loader_data() const { return _class_loader_data; } 256 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; } 257 258 // The Klasses are not placed in the Heap, so the Card Table or 259 // the Mod Union Table can't be used to mark when klasses have modified oops. 260 // The CT and MUT bits saves this information for the individual Klasses. 261 void record_modified_oops() { _modified_oops = 1; } 262 void clear_modified_oops() { _modified_oops = 0; } 263 bool has_modified_oops() { return _modified_oops == 1; } 264 265 void accumulate_modified_oops() { if (has_modified_oops()) _accumulated_modified_oops = 1; } 266 void clear_accumulated_modified_oops() { _accumulated_modified_oops = 0; } 267 bool has_accumulated_modified_oops() { return _accumulated_modified_oops == 1; } 268 269 int shared_classpath_index() const { 270 return _shared_class_path_index; 271 }; 272 273 void set_shared_classpath_index(int index) { 274 _shared_class_path_index = index; 275 }; 276 277 278 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 = 2, 306 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits, 307 _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30 308 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30 309 }; 310 311 static const juint _lh_array_bit = 1 << (BitsPerInt - 1); // 0x80000000 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 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift); 329 return (juint)lh >= (juint)(uint(_lh_array_tag_type_value) << _lh_array_tag_shift); 330 } 331 static bool layout_helper_is_objArray(jint lh) { 332 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift); 333 return (jint)lh < (jint)(uint(_lh_array_tag_type_value) << _lh_array_tag_shift); 334 } 335 static int layout_helper_header_size(jint lh) { 336 assert(lh < (jint)_lh_neutral_value, "must be array"); 337 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask; 338 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity"); 339 return hsize; 340 } 341 static BasicType layout_helper_element_type(jint lh) { 342 assert(lh < (jint)_lh_neutral_value, "must be array"); 343 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask; 344 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity"); 345 return (BasicType) btvalue; 346 } 347 static int layout_helper_log2_element_size(jint lh) { 348 assert(lh < (jint)_lh_neutral_value, "must be array"); 349 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask; 350 assert(l2esz <= LogBitsPerLong, 351 "sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh); 352 return l2esz; 353 } 354 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) { 355 return (tag << _lh_array_tag_shift) 356 | (hsize << _lh_header_size_shift) 357 | ((int)etype << _lh_element_type_shift) 358 | (log2_esize << _lh_log2_element_size_shift); 359 } 360 static jint instance_layout_helper(jint size, bool slow_path_flag) { 361 return (size << LogBytesPerWord) 362 | (slow_path_flag ? _lh_instance_slow_path_bit : 0); 363 } 364 static int layout_helper_to_size_helper(jint lh) { 365 assert(lh > (jint)_lh_neutral_value, "must be instance"); 366 // Note that the following expression discards _lh_instance_slow_path_bit. 367 return lh >> LogBytesPerWord; 368 } 369 // Out-of-line version computes everything based on the etype: 370 static jint array_layout_helper(BasicType etype); 371 372 // What is the maximum number of primary superclasses any klass can have? 373 #ifdef PRODUCT 374 static juint primary_super_limit() { return _primary_super_limit; } 375 #else 376 static juint primary_super_limit() { 377 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob"); 378 return FastSuperclassLimit; 379 } 380 #endif 381 382 // vtables 383 klassVtable* vtable() const; 384 int vtable_length() const { return _vtable_len; } 385 386 // subclass check 387 bool is_subclass_of(const Klass* k) const; 388 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it 389 bool is_subtype_of(Klass* k) const { 390 juint off = k->super_check_offset(); 391 Klass* sup = *(Klass**)( (address)this + off ); 392 const juint secondary_offset = in_bytes(secondary_super_cache_offset()); 393 if (sup == k) { 394 return true; 395 } else if (off != secondary_offset) { 396 return false; 397 } else { 398 return search_secondary_supers(k); 399 } 400 } 401 bool search_secondary_supers(Klass* k) const; 402 403 // Find LCA in class hierarchy 404 Klass *LCA( Klass *k ); 405 406 // Check whether reflection/jni/jvm code is allowed to instantiate this class; 407 // if not, throw either an Error or an Exception. 408 virtual void check_valid_for_instantiation(bool throwError, TRAPS); 409 410 // array copying 411 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS); 412 413 // tells if the class should be initialized 414 virtual bool should_be_initialized() const { return false; } 415 // initializes the klass 416 virtual void initialize(TRAPS); 417 // lookup operation for MethodLookupCache 418 friend class MethodLookupCache; 419 virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const; 420 virtual Method* uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const; 421 public: 422 Method* lookup_method(const Symbol* name, const Symbol* signature) const { 423 return uncached_lookup_method(name, signature, find_overpass); 424 } 425 426 // array class with specific rank 427 Klass* array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); } 428 429 // array class with this klass as element type 430 Klass* array_klass(TRAPS) { return array_klass_impl(false, THREAD); } 431 432 // These will return NULL instead of allocating on the heap: 433 // NB: these can block for a mutex, like other functions with TRAPS arg. 434 Klass* array_klass_or_null(int rank); 435 Klass* array_klass_or_null(); 436 437 virtual oop protection_domain() const = 0; 438 439 oop class_loader() const; 440 441 virtual oop klass_holder() const { return class_loader(); } 442 443 protected: 444 virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS); 445 virtual Klass* array_klass_impl(bool or_null, TRAPS); 446 447 void set_vtable_length(int len) { _vtable_len= len; } 448 449 vtableEntry* start_of_vtable() const; 450 public: 451 Method* method_at_vtable(int index); 452 453 static ByteSize vtable_start_offset(); 454 static ByteSize vtable_length_offset() { 455 return byte_offset_of(Klass, _vtable_len); 456 } 457 458 // CDS support - remove and restore oops from metadata. Oops are not shared. 459 virtual void remove_unshareable_info(); 460 virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS); 461 462 protected: 463 // computes the subtype relationship 464 virtual bool compute_is_subtype_of(Klass* k); 465 public: 466 // subclass accessor (here for convenience; undefined for non-klass objects) 467 virtual bool is_leaf_class() const { fatal("not a class"); return false; } 468 public: 469 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP 470 // These functions describe behavior for the oop not the KLASS. 471 472 // actual oop size of obj in memory 473 virtual int oop_size(oop obj) const = 0; 474 475 // Size of klass in word size. 476 virtual int size() const = 0; 477 #if INCLUDE_SERVICES 478 virtual void collect_statistics(KlassSizeStats *sz) const; 479 #endif 480 481 // Returns the Java name for a class (Resource allocated) 482 // For arrays, this returns the name of the element with a leading '['. 483 // For classes, this returns the name with the package separators 484 // turned into '.'s. 485 const char* external_name() const; 486 // Returns the name for a class (Resource allocated) as the class 487 // would appear in a signature. 488 // For arrays, this returns the name of the element with a leading '['. 489 // For classes, this returns the name with a leading 'L' and a trailing ';' 490 // and the package separators as '/'. 491 virtual const char* signature_name() const; 492 493 // type testing operations 494 #ifdef ASSERT 495 protected: 496 virtual bool is_instance_klass_slow() const { return false; } 497 virtual bool is_array_klass_slow() const { return false; } 498 virtual bool is_objArray_klass_slow() const { return false; } 499 virtual bool is_typeArray_klass_slow() const { return false; } 500 #endif // ASSERT 501 public: 502 503 // Fast non-virtual versions 504 #ifndef ASSERT 505 #define assert_same_query(xval, xcheck) xval 506 #else 507 private: 508 static bool assert_same_query(bool xval, bool xslow) { 509 assert(xval == xslow, "slow and fast queries agree"); 510 return xval; 511 } 512 public: 513 #endif 514 inline bool is_instance_klass() const { return assert_same_query( 515 layout_helper_is_instance(layout_helper()), 516 is_instance_klass_slow()); } 517 inline bool is_array_klass() const { return assert_same_query( 518 layout_helper_is_array(layout_helper()), 519 is_array_klass_slow()); } 520 inline bool is_objArray_klass() const { return assert_same_query( 521 layout_helper_is_objArray(layout_helper()), 522 is_objArray_klass_slow()); } 523 inline bool is_typeArray_klass() const { return assert_same_query( 524 layout_helper_is_typeArray(layout_helper()), 525 is_typeArray_klass_slow()); } 526 #undef assert_same_query 527 528 // Access flags 529 AccessFlags access_flags() const { return _access_flags; } 530 void set_access_flags(AccessFlags flags) { _access_flags = flags; } 531 532 bool is_public() const { return _access_flags.is_public(); } 533 bool is_final() const { return _access_flags.is_final(); } 534 bool is_interface() const { return _access_flags.is_interface(); } 535 bool is_abstract() const { return _access_flags.is_abstract(); } 536 bool is_super() const { return _access_flags.is_super(); } 537 bool is_synthetic() const { return _access_flags.is_synthetic(); } 538 void set_is_synthetic() { _access_flags.set_is_synthetic(); } 539 bool has_finalizer() const { return _access_flags.has_finalizer(); } 540 bool has_final_method() const { return _access_flags.has_final_method(); } 541 void set_has_finalizer() { _access_flags.set_has_finalizer(); } 542 void set_has_final_method() { _access_flags.set_has_final_method(); } 543 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); } 544 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); } 545 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); } 546 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); } 547 548 bool is_cloneable() const; 549 void set_is_cloneable(); 550 551 // Biased locking support 552 // Note: the prototype header is always set up to be at least the 553 // prototype markOop. If biased locking is enabled it may further be 554 // biasable and have an epoch. 555 markOop prototype_header() const { return _prototype_header; } 556 // NOTE: once instances of this klass are floating around in the 557 // system, this header must only be updated at a safepoint. 558 // NOTE 2: currently we only ever set the prototype header to the 559 // biasable prototype for instanceKlasses. There is no technical 560 // reason why it could not be done for arrayKlasses aside from 561 // wanting to reduce the initial scope of this optimization. There 562 // are potential problems in setting the bias pattern for 563 // JVM-internal oops. 564 inline void set_prototype_header(markOop header); 565 static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); } 566 567 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; } 568 // Atomically increments biased_lock_revocation_count and returns updated value 569 int atomic_incr_biased_lock_revocation_count(); 570 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; } 571 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; } 572 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; } 573 574 TRACE_DEFINE_TRACE_ID_METHODS; 575 576 // garbage collection support 577 void oops_do(OopClosure* cl); 578 579 // Iff the class loader (or mirror for anonymous classes) is alive the 580 // Klass is considered alive. 581 // The is_alive closure passed in depends on the Garbage Collector used. 582 bool is_loader_alive(BoolObjectClosure* is_alive); 583 584 static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true); 585 static void clean_subklass_tree(BoolObjectClosure* is_alive) { 586 clean_weak_klass_links(is_alive, false /* clean_alive_klasses */); 587 } 588 589 // GC specific object visitors 590 // 591 // Mark Sweep 592 virtual int oop_ms_adjust_pointers(oop obj) = 0; 593 #if INCLUDE_ALL_GCS 594 // Parallel Scavenge 595 virtual void oop_ps_push_contents( oop obj, PSPromotionManager* pm) = 0; 596 // Parallel Compact 597 virtual void oop_pc_follow_contents(oop obj, ParCompactionManager* cm) = 0; 598 virtual void oop_pc_update_pointers(oop obj, ParCompactionManager* cm) = 0; 599 #endif 600 601 // Iterators specialized to particular subtypes 602 // of ExtendedOopClosure, to avoid closure virtual calls. 603 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 604 virtual void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) = 0; \ 605 /* Iterates "closure" over all the oops in "obj" (of type "this") within "mr". */ \ 606 virtual void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) = 0; 607 608 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL) 609 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL) 610 611 #if INCLUDE_ALL_GCS 612 #define Klass_OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \ 613 virtual void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) = 0; 614 615 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS) 616 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS) 617 #endif // INCLUDE_ALL_GCS 618 619 virtual void array_klasses_do(void f(Klass* k)) {} 620 621 // Return self, except for abstract classes with exactly 1 622 // implementor. Then return the 1 concrete implementation. 623 Klass *up_cast_abstract(); 624 625 // klass name 626 Symbol* name() const { return _name; } 627 void set_name(Symbol* n); 628 629 public: 630 // jvm support 631 virtual jint compute_modifier_flags(TRAPS) const; 632 633 // JVMTI support 634 virtual jint jvmti_class_status() const; 635 636 // Printing 637 virtual void print_on(outputStream* st) const; 638 639 virtual void oop_print_value_on(oop obj, outputStream* st); 640 virtual void oop_print_on (oop obj, outputStream* st); 641 642 virtual const char* internal_name() const = 0; 643 644 // Verification 645 virtual void verify_on(outputStream* st); 646 void verify() { verify_on(tty); } 647 648 #ifndef PRODUCT 649 bool verify_vtable_index(int index); 650 bool verify_itable_index(int index); 651 #endif 652 653 virtual void oop_verify_on(oop obj, outputStream* st); 654 655 static bool is_null(narrowKlass obj); 656 static bool is_null(Klass* obj); 657 658 // klass encoding for klass pointer in objects. 659 static narrowKlass encode_klass_not_null(Klass* v); 660 static narrowKlass encode_klass(Klass* v); 661 662 static Klass* decode_klass_not_null(narrowKlass v); 663 static Klass* decode_klass(narrowKlass v); 664 665 private: 666 // barriers used by klass_oop_store 667 void klass_update_barrier_set(oop v); 668 void klass_update_barrier_set_pre(oop* p, oop v); 669 }; 670 671 // Helper to convert the oop iterate macro suffixes into bool values that can be used by template functions. 672 #define nvs_nv_to_bool true 673 #define nvs_v_to_bool false 674 #define nvs_to_bool(nv_suffix) nvs##nv_suffix##_to_bool 675 676 // Oop iteration macros for declarations. 677 // Used to generate declarations in the *Klass header files. 678 679 #define OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 680 void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure); \ 681 void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr); 682 683 #if INCLUDE_ALL_GCS 684 #define OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \ 685 void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure); 686 #endif // INCLUDE_ALL_GCS 687 688 689 // Oop iteration macros for definitions. 690 // Used to generate definitions in the *Klass.inline.hpp files. 691 692 #define OOP_OOP_ITERATE_DEFN(KlassType, OopClosureType, nv_suffix) \ 693 void KlassType::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \ 694 oop_oop_iterate<nvs_to_bool(nv_suffix)>(obj, closure); \ 695 } 696 697 #if INCLUDE_ALL_GCS 698 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix) \ 699 void KlassType::oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) { \ 700 oop_oop_iterate_reverse<nvs_to_bool(nv_suffix)>(obj, closure); \ 701 } 702 #else 703 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix) 704 #endif 705 706 #define OOP_OOP_ITERATE_DEFN_BOUNDED(KlassType, OopClosureType, nv_suffix) \ 707 void KlassType::oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) { \ 708 oop_oop_iterate_bounded<nvs_to_bool(nv_suffix)>(obj, closure, mr); \ 709 } 710 711 #endif // SHARE_VM_OOPS_KLASS_HPP