1 /*
2 * Copyright (c) 1997, 2017, 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 *
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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).
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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 "oops/oopHandle.hpp"
34 #include "trace/traceMacros.hpp"
35 #include "utilities/accessFlags.hpp"
36 #include "utilities/macros.hpp"
37
38 //
39 // A Klass provides:
40 // 1: language level class object (method dictionary etc.)
41 // 2: provide vm dispatch behavior for the object
42 // Both functions are combined into one C++ class.
43
44 // One reason for the oop/klass dichotomy in the implementation is
45 // that we don't want a C++ vtbl pointer in every object. Thus,
46 // normal oops don't have any virtual functions. Instead, they
47 // forward all "virtual" functions to their klass, which does have
48 // a vtbl and does the C++ dispatch depending on the object's
49 // actual type. (See oop.inline.hpp for some of the forwarding code.)
50 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"!
51
52 // Forward declarations.
53 template <class T> class Array;
54 template <class T> class GrowableArray;
55 class ClassLoaderData;
56 class fieldDescriptor;
57 class KlassSizeStats;
58 class klassVtable;
59 class ModuleEntry;
60 class PackageEntry;
61 class ParCompactionManager;
62 class PSPromotionManager;
63 class vtableEntry;
64
65 class Klass : public Metadata {
66 friend class VMStructs;
67 friend class JVMCIVMStructs;
68 protected:
69 // If you add a new field that points to any metaspace object, you
70 // must add this field to Klass::metaspace_pointers_do().
71
72 // note: put frequently-used fields together at start of klass structure
73 // for better cache behavior (may not make much of a difference but sure won't hurt)
74 enum { _primary_super_limit = 8 };
75
76 // The "layout helper" is a combined descriptor of object layout.
77 // For klasses which are neither instance nor array, the value is zero.
78 //
79 // For instances, layout helper is a positive number, the instance size.
80 // This size is already passed through align_object_size and scaled to bytes.
81 // The low order bit is set if instances of this class cannot be
82 // allocated using the fastpath.
83 //
84 // For arrays, layout helper is a negative number, containing four
85 // distinct bytes, as follows:
86 // MSB:[tag, hsz, ebt, log2(esz)]:LSB
87 // where:
88 // tag is 0x80 if the elements are oops, 0xC0 if non-oops
89 // hsz is array header size in bytes (i.e., offset of first element)
90 // ebt is the BasicType of the elements
91 // esz is the element size in bytes
92 // This packed word is arranged so as to be quickly unpacked by the
93 // various fast paths that use the various subfields.
94 //
95 // The esz bits can be used directly by a SLL instruction, without masking.
96 //
97 // Note that the array-kind tag looks like 0x00 for instance klasses,
98 // since their length in bytes is always less than 24Mb.
99 //
100 // Final note: This comes first, immediately after C++ vtable,
101 // because it is frequently queried.
102 jint _layout_helper;
103
104 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers
105 // and _primary_supers all help make fast subtype checks. See big discussion
106 // in doc/server_compiler/checktype.txt
107 //
108 // Where to look to observe a supertype (it is &_secondary_super_cache for
109 // secondary supers, else is &_primary_supers[depth()].
110 juint _super_check_offset;
111
112 // Class name. Instance classes: java/lang/String, etc. Array classes: [I,
113 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes.
114 Symbol* _name;
115
116 // Cache of last observed secondary supertype
117 Klass* _secondary_super_cache;
118 // Array of all secondary supertypes
119 Array<Klass*>* _secondary_supers;
120 // Ordered list of all primary supertypes
121 Klass* _primary_supers[_primary_super_limit];
122 // java/lang/Class instance mirroring this class
123 OopHandle _java_mirror;
124 // Superclass
125 Klass* _super;
126 // First subclass (NULL if none); _subklass->next_sibling() is next one
127 Klass* _subklass;
128 // Sibling link (or NULL); links all subklasses of a klass
129 Klass* _next_sibling;
130
131 // All klasses loaded by a class loader are chained through these links
132 Klass* _next_link;
133
134 // The VM's representation of the ClassLoader used to load this class.
135 // Provide access the corresponding instance java.lang.ClassLoader.
136 ClassLoaderData* _class_loader_data;
137
138 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers.
139 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here.
140
141 TRACE_DEFINE_TRACE_ID_FIELD;
142
143 // Biased locking implementation and statistics
144 // (the 64-bit chunk goes first, to avoid some fragmentation)
145 jlong _last_biased_lock_bulk_revocation_time;
146 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type
147 jint _biased_lock_revocation_count;
148
149 // vtable length
150 int _vtable_len;
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 // java mirror
229 oop java_mirror() const;
230 void set_java_mirror(Handle m);
231
232 // modifier flags
233 jint modifier_flags() const { return _modifier_flags; }
234 void set_modifier_flags(jint flags) { _modifier_flags = flags; }
235
236 // size helper
237 int layout_helper() const { return _layout_helper; }
238 void set_layout_helper(int lh) { _layout_helper = lh; }
239
240 // Note: for instances layout_helper() may include padding.
241 // Use InstanceKlass::contains_field_offset to classify field offsets.
242
243 // sub/superklass links
244 Klass* subklass() const { return _subklass; }
245 Klass* next_sibling() const { return _next_sibling; }
246 InstanceKlass* superklass() const;
247 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list
248
249 void set_next_link(Klass* k) { _next_link = k; }
250 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader.
251
252 // class loader data
253 ClassLoaderData* class_loader_data() const { return _class_loader_data; }
254 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; }
255
256 int shared_classpath_index() const {
257 return _shared_class_path_index;
258 };
259
260 void set_shared_classpath_index(int index) {
261 _shared_class_path_index = index;
262 };
263
264 // Obtain the module or package for this class
265 virtual ModuleEntry* module() const = 0;
266 virtual PackageEntry* package() const = 0;
267
268 protected: // internal accessors
269 void set_subklass(Klass* s);
270 void set_next_sibling(Klass* s);
271
272 public:
273
274 // Compiler support
275 static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); }
276 static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); }
277 static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); }
278 static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); }
279 static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); }
280 static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); }
281 static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); }
282 static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); }
283 static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); }
284
285 // Unpacking layout_helper:
286 enum {
287 _lh_neutral_value = 0, // neutral non-array non-instance value
288 _lh_instance_slow_path_bit = 0x01,
289 _lh_log2_element_size_shift = BitsPerByte*0,
290 _lh_log2_element_size_mask = BitsPerLong-1,
291 _lh_element_type_shift = BitsPerByte*1,
292 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask
293 _lh_header_size_shift = BitsPerByte*2,
294 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask
295 _lh_array_tag_bits = 2,
296 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits,
297 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30
298 };
299
300 static const unsigned int _lh_array_tag_type_value = 0Xffffffff; // ~0x00, // 0xC0000000 >> 30
301
302 static int layout_helper_size_in_bytes(jint lh) {
303 assert(lh > (jint)_lh_neutral_value, "must be instance");
304 return (int) lh & ~_lh_instance_slow_path_bit;
305 }
306 static bool layout_helper_needs_slow_path(jint lh) {
307 assert(lh > (jint)_lh_neutral_value, "must be instance");
308 return (lh & _lh_instance_slow_path_bit) != 0;
309 }
310 static bool layout_helper_is_instance(jint lh) {
311 return (jint)lh > (jint)_lh_neutral_value;
312 }
313 static bool layout_helper_is_array(jint lh) {
314 return (jint)lh < (jint)_lh_neutral_value;
315 }
316 static bool layout_helper_is_typeArray(jint lh) {
317 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift);
318 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift);
319 }
320 static bool layout_helper_is_objArray(jint lh) {
321 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift);
322 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift);
323 }
324 static int layout_helper_header_size(jint lh) {
325 assert(lh < (jint)_lh_neutral_value, "must be array");
326 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask;
327 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity");
328 return hsize;
329 }
330 static BasicType layout_helper_element_type(jint lh) {
331 assert(lh < (jint)_lh_neutral_value, "must be array");
332 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask;
333 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity");
334 return (BasicType) btvalue;
335 }
336
337 // Want a pattern to quickly diff against layout header in register
338 // find something less clever!
339 static int layout_helper_boolean_diffbit() {
340 jint zlh = array_layout_helper(T_BOOLEAN);
341 jint blh = array_layout_helper(T_BYTE);
342 assert(zlh != blh, "array layout helpers must differ");
343 int diffbit = 1;
344 while ((diffbit & (zlh ^ blh)) == 0 && (diffbit & zlh) == 0) {
345 diffbit <<= 1;
346 assert(diffbit != 0, "make sure T_BOOLEAN has a different bit than T_BYTE");
347 }
348 return diffbit;
349 }
350
351 static int layout_helper_log2_element_size(jint lh) {
352 assert(lh < (jint)_lh_neutral_value, "must be array");
353 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask;
354 assert(l2esz <= LogBytesPerLong,
355 "sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh);
356 return l2esz;
357 }
358 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) {
359 return (tag << _lh_array_tag_shift)
360 | (hsize << _lh_header_size_shift)
361 | ((int)etype << _lh_element_type_shift)
362 | (log2_esize << _lh_log2_element_size_shift);
363 }
364 static jint instance_layout_helper(jint size, bool slow_path_flag) {
365 return (size << LogBytesPerWord)
366 | (slow_path_flag ? _lh_instance_slow_path_bit : 0);
367 }
368 static int layout_helper_to_size_helper(jint lh) {
369 assert(lh > (jint)_lh_neutral_value, "must be instance");
370 // Note that the following expression discards _lh_instance_slow_path_bit.
371 return lh >> LogBytesPerWord;
372 }
373 // Out-of-line version computes everything based on the etype:
374 static jint array_layout_helper(BasicType etype);
375
376 // What is the maximum number of primary superclasses any klass can have?
377 #ifdef PRODUCT
378 static juint primary_super_limit() { return _primary_super_limit; }
379 #else
380 static juint primary_super_limit() {
381 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob");
382 return FastSuperclassLimit;
383 }
384 #endif
385
386 // vtables
387 klassVtable vtable() const;
388 int vtable_length() const { return _vtable_len; }
389
390 // subclass check
391 bool is_subclass_of(const Klass* k) const;
392 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it
393 bool is_subtype_of(Klass* k) const {
394 juint off = k->super_check_offset();
395 Klass* sup = *(Klass**)( (address)this + off );
396 const juint secondary_offset = in_bytes(secondary_super_cache_offset());
397 if (sup == k) {
398 return true;
399 } else if (off != secondary_offset) {
400 return false;
401 } else {
402 return search_secondary_supers(k);
403 }
404 }
405 bool search_secondary_supers(Klass* k) const;
406
407 // Find LCA in class hierarchy
408 Klass *LCA( Klass *k );
409
410 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
411 // if not, throw either an Error or an Exception.
412 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
413
414 // array copying
415 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
416
417 // tells if the class should be initialized
418 virtual bool should_be_initialized() const { return false; }
419 // initializes the klass
420 virtual void initialize(TRAPS);
421 // lookup operation for MethodLookupCache
422 friend class MethodLookupCache;
423 virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const;
424 virtual Method* uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const;
425 public:
426 Method* lookup_method(const Symbol* name, const Symbol* signature) const {
427 return uncached_lookup_method(name, signature, find_overpass);
428 }
429
430 // array class with specific rank
431 Klass* array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); }
432
433 // array class with this klass as element type
434 Klass* array_klass(TRAPS) { return array_klass_impl(false, THREAD); }
435
436 // These will return NULL instead of allocating on the heap:
437 // NB: these can block for a mutex, like other functions with TRAPS arg.
438 Klass* array_klass_or_null(int rank);
439 Klass* array_klass_or_null();
440
441 virtual oop protection_domain() const = 0;
442
443 oop class_loader() const;
444
445 virtual oop klass_holder() const { return class_loader(); }
446
447 protected:
448 virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS);
449 virtual Klass* array_klass_impl(bool or_null, TRAPS);
450
451 void set_vtable_length(int len) { _vtable_len= len; }
452
453 vtableEntry* start_of_vtable() const;
454 public:
455 Method* method_at_vtable(int index);
456
457 static ByteSize vtable_start_offset();
458 static ByteSize vtable_length_offset() {
459 return byte_offset_of(Klass, _vtable_len);
460 }
461
462 // CDS support - remove and restore oops from metadata. Oops are not shared.
463 virtual void remove_unshareable_info();
464 virtual void remove_java_mirror();
465 virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
466
467 protected:
468 // computes the subtype relationship
469 virtual bool compute_is_subtype_of(Klass* k);
470 public:
471 // subclass accessor (here for convenience; undefined for non-klass objects)
472 virtual bool is_leaf_class() const { fatal("not a class"); return false; }
473 public:
474 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP
475 // These functions describe behavior for the oop not the KLASS.
476
477 // actual oop size of obj in memory
478 virtual int oop_size(oop obj) const = 0;
479
480 // Size of klass in word size.
481 virtual int size() const = 0;
482 #if INCLUDE_SERVICES
483 virtual void collect_statistics(KlassSizeStats *sz) const;
484 #endif
485
486 // Returns the Java name for a class (Resource allocated)
487 // For arrays, this returns the name of the element with a leading '['.
488 // For classes, this returns the name with the package separators
489 // turned into '.'s.
490 const char* external_name() const;
491 // Returns the name for a class (Resource allocated) as the class
492 // would appear in a signature.
493 // For arrays, this returns the name of the element with a leading '['.
494 // For classes, this returns the name with a leading 'L' and a trailing ';'
495 // and the package separators as '/'.
496 virtual const char* signature_name() const;
497
498 // type testing operations
499 #ifdef ASSERT
500 protected:
501 virtual bool is_instance_klass_slow() const { return false; }
502 virtual bool is_array_klass_slow() const { return false; }
503 virtual bool is_objArray_klass_slow() const { return false; }
504 virtual bool is_typeArray_klass_slow() const { return false; }
505 #endif // ASSERT
506 public:
507
508 // Fast non-virtual versions
509 #ifndef ASSERT
510 #define assert_same_query(xval, xcheck) xval
511 #else
512 private:
513 static bool assert_same_query(bool xval, bool xslow) {
514 assert(xval == xslow, "slow and fast queries agree");
515 return xval;
516 }
517 public:
518 #endif
519 inline bool is_instance_klass() const { return assert_same_query(
520 layout_helper_is_instance(layout_helper()),
521 is_instance_klass_slow()); }
522 inline bool is_array_klass() const { return assert_same_query(
523 layout_helper_is_array(layout_helper()),
524 is_array_klass_slow()); }
525 inline bool is_objArray_klass() const { return assert_same_query(
526 layout_helper_is_objArray(layout_helper()),
527 is_objArray_klass_slow()); }
528 inline bool is_typeArray_klass() const { return assert_same_query(
529 layout_helper_is_typeArray(layout_helper()),
530 is_typeArray_klass_slow()); }
531 #undef assert_same_query
532
533 // Access flags
534 AccessFlags access_flags() const { return _access_flags; }
535 void set_access_flags(AccessFlags flags) { _access_flags = flags; }
536
537 bool is_public() const { return _access_flags.is_public(); }
538 bool is_final() const { return _access_flags.is_final(); }
539 bool is_interface() const { return _access_flags.is_interface(); }
540 bool is_abstract() const { return _access_flags.is_abstract(); }
541 bool is_super() const { return _access_flags.is_super(); }
542 bool is_synthetic() const { return _access_flags.is_synthetic(); }
543 void set_is_synthetic() { _access_flags.set_is_synthetic(); }
544 bool has_finalizer() const { return _access_flags.has_finalizer(); }
545 bool has_final_method() const { return _access_flags.has_final_method(); }
546 void set_has_finalizer() { _access_flags.set_has_finalizer(); }
547 void set_has_final_method() { _access_flags.set_has_final_method(); }
548 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); }
549 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); }
550 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); }
551 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); }
552 bool is_shared() const { return access_flags().is_shared_class(); } // shadows MetaspaceObj::is_shared)()
553 void set_is_shared() { _access_flags.set_is_shared_class(); }
554
555 bool is_cloneable() const;
556 void set_is_cloneable();
557
558 // Biased locking support
559 // Note: the prototype header is always set up to be at least the
560 // prototype markOop. If biased locking is enabled it may further be
561 // biasable and have an epoch.
562 markOop prototype_header() const { return _prototype_header; }
563 // NOTE: once instances of this klass are floating around in the
564 // system, this header must only be updated at a safepoint.
565 // NOTE 2: currently we only ever set the prototype header to the
566 // biasable prototype for instanceKlasses. There is no technical
567 // reason why it could not be done for arrayKlasses aside from
568 // wanting to reduce the initial scope of this optimization. There
569 // are potential problems in setting the bias pattern for
570 // JVM-internal oops.
571 inline void set_prototype_header(markOop header);
572 static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); }
573
574 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; }
575 // Atomically increments biased_lock_revocation_count and returns updated value
576 int atomic_incr_biased_lock_revocation_count();
577 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; }
578 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; }
579 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; }
580
581 TRACE_DEFINE_TRACE_ID_METHODS;
582
583 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
584 virtual MetaspaceObj::Type type() const { return ClassType; }
585
586 // Iff the class loader (or mirror for anonymous classes) is alive the
587 // Klass is considered alive.
588 // The is_alive closure passed in depends on the Garbage Collector used.
589 bool is_loader_alive(BoolObjectClosure* is_alive);
590
591 static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true);
592 static void clean_subklass_tree(BoolObjectClosure* is_alive) {
593 clean_weak_klass_links(is_alive, false /* clean_alive_klasses */);
594 }
595
596 // GC specific object visitors
597 //
598 #if INCLUDE_ALL_GCS
599 // Parallel Scavenge
600 virtual void oop_ps_push_contents( oop obj, PSPromotionManager* pm) = 0;
601 // Parallel Compact
602 virtual void oop_pc_follow_contents(oop obj, ParCompactionManager* cm) = 0;
603 virtual void oop_pc_update_pointers(oop obj, ParCompactionManager* cm) = 0;
604 #endif
605
606 // Iterators specialized to particular subtypes
607 // of ExtendedOopClosure, to avoid closure virtual calls.
608 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
609 virtual void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) = 0; \
610 /* Iterates "closure" over all the oops in "obj" (of type "this") within "mr". */ \
611 virtual void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) = 0;
612
613 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL)
614 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL)
615
616 #if INCLUDE_ALL_GCS
617 #define Klass_OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \
618 virtual void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) = 0;
619
620 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
621 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
622 #endif // INCLUDE_ALL_GCS
623
624 virtual void array_klasses_do(void f(Klass* k)) {}
625
626 // Return self, except for abstract classes with exactly 1
627 // implementor. Then return the 1 concrete implementation.
628 Klass *up_cast_abstract();
629
630 // klass name
631 Symbol* name() const { return _name; }
632 void set_name(Symbol* n);
633
634 public:
635 // jvm support
636 virtual jint compute_modifier_flags(TRAPS) const;
637
638 // JVMTI support
639 virtual jint jvmti_class_status() const;
640
641 // Printing
642 virtual void print_on(outputStream* st) const;
643
644 virtual void oop_print_value_on(oop obj, outputStream* st);
645 virtual void oop_print_on (oop obj, outputStream* st);
646
647 virtual const char* internal_name() const = 0;
648
649 // Verification
650 virtual void verify_on(outputStream* st);
651 void verify() { verify_on(tty); }
652
653 #ifndef PRODUCT
654 bool verify_vtable_index(int index);
655 bool verify_itable_index(int index);
656 #endif
657
658 virtual void oop_verify_on(oop obj, outputStream* st);
659
660 static bool is_null(narrowKlass obj);
661 static bool is_null(Klass* obj);
662
663 // klass encoding for klass pointer in objects.
664 static narrowKlass encode_klass_not_null(Klass* v);
665 static narrowKlass encode_klass(Klass* v);
666
667 static Klass* decode_klass_not_null(narrowKlass v);
668 static Klass* decode_klass(narrowKlass 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