1 /*
2 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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
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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 "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
61 class Klass : public Metadata {
62 friend class VMStructs;
63 friend class JVMCIVMStructs;
64 protected:
65 // note: put frequently-used fields together at start of klass structure
66 // for better cache behavior (may not make much of a difference but sure won't hurt)
67 enum { _primary_super_limit = 8 };
68
69 // The "layout helper" is a combined descriptor of object layout.
70 // For klasses which are neither instance nor array, the value is zero.
71 //
72 // For instances, layout helper is a positive number, the instance size.
73 // This size is already passed through align_object_size and scaled to bytes.
74 // The low order bit is set if instances of this class cannot be
75 // allocated using the fastpath.
76 //
77 // For arrays, layout helper is a negative number, containing four
78 // distinct bytes, as follows:
79 // MSB:[tag, hsz, ebt, log2(esz)]:LSB
80 // where:
81 // tag is 0x80 if the elements are oops, 0xC0 if non-oops
82 // hsz is array header size in bytes (i.e., offset of first element)
83 // ebt is the BasicType of the elements
84 // esz is the element size in bytes
85 // This packed word is arranged so as to be quickly unpacked by the
86 // various fast paths that use the various subfields.
87 //
88 // The esz bits can be used directly by a SLL instruction, without masking.
89 //
90 // Note that the array-kind tag looks like 0x00 for instance klasses,
91 // since their length in bytes is always less than 24Mb.
92 //
93 // Final note: This comes first, immediately after C++ vtable,
94 // because it is frequently queried.
95 jint _layout_helper;
96
97 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers
98 // and _primary_supers all help make fast subtype checks. See big discussion
99 // in doc/server_compiler/checktype.txt
100 //
101 // Where to look to observe a supertype (it is &_secondary_super_cache for
102 // secondary supers, else is &_primary_supers[depth()].
103 juint _super_check_offset;
104
105 // Class name. Instance classes: java/lang/String, etc. Array classes: [I,
106 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes.
107 Symbol* _name;
108
109 // Cache of last observed secondary supertype
110 Klass* _secondary_super_cache;
111 // Array of all secondary supertypes
112 Array<Klass*>* _secondary_supers;
113 // Ordered list of all primary supertypes
114 Klass* _primary_supers[_primary_super_limit];
115 // java/lang/Class instance mirroring this class
116 oop _java_mirror;
117 // Superclass
118 Klass* _super;
119 // First subclass (NULL if none); _subklass->next_sibling() is next one
120 Klass* _subklass;
121 // Sibling link (or NULL); links all subklasses of a klass
122 Klass* _next_sibling;
123
124 // All klasses loaded by a class loader are chained through these links
125 Klass* _next_link;
126
127 // The VM's representation of the ClassLoader used to load this class.
128 // Provide access the corresponding instance java.lang.ClassLoader.
129 ClassLoaderData* _class_loader_data;
130
131 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers.
132 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here.
133
134 // Biased locking implementation and statistics
135 // (the 64-bit chunk goes first, to avoid some fragmentation)
136 jlong _last_biased_lock_bulk_revocation_time;
137 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type
138 jint _biased_lock_revocation_count;
139
140 TRACE_DEFINE_KLASS_TRACE_ID;
141
142 // Remembered sets support for the oops in the klasses.
143 jbyte _modified_oops; // Card Table Equivalent (YC/CMS support)
144 jbyte _accumulated_modified_oops; // Mod Union Equivalent (CMS support)
145
146 private:
147 // This is an index into FileMapHeader::_classpath_entry_table[], to
148 // associate this class with the JAR file where it's loaded from during
149 // dump time. If a class is not loaded from the shared archive, this field is
150 // -1.
151 jshort _shared_class_path_index;
152
153 friend class SharedClassUtil;
154 protected:
155
156 // Constructor
157 Klass();
158
159 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw();
160
161 public:
162 enum DefaultsLookupMode { find_defaults, skip_defaults };
163 enum OverpassLookupMode { find_overpass, skip_overpass };
164 enum StaticLookupMode { find_static, skip_static };
165 enum PrivateLookupMode { find_private, skip_private };
166
167 bool is_klass() const volatile { return true; }
168
169 // super
170 Klass* super() const { return _super; }
171 void set_super(Klass* k) { _super = k; }
172
173 // initializes _super link, _primary_supers & _secondary_supers arrays
174 void initialize_supers(Klass* k, TRAPS);
175 void initialize_supers_impl1(Klass* k);
176 void initialize_supers_impl2(Klass* k);
177
178 // klass-specific helper for initializing _secondary_supers
179 virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
180
181 // java_super is the Java-level super type as specified by Class.getSuperClass.
182 virtual Klass* java_super() const { return NULL; }
183
184 juint super_check_offset() const { return _super_check_offset; }
185 void set_super_check_offset(juint o) { _super_check_offset = o; }
186
187 Klass* secondary_super_cache() const { return _secondary_super_cache; }
188 void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; }
189
190 Array<Klass*>* secondary_supers() const { return _secondary_supers; }
191 void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; }
192
193 // Return the element of the _super chain of the given depth.
194 // If there is no such element, return either NULL or this.
195 Klass* primary_super_of_depth(juint i) const {
196 assert(i < primary_super_limit(), "oob");
197 Klass* super = _primary_supers[i];
198 assert(super == NULL || super->super_depth() == i, "correct display");
199 return super;
200 }
201
202 // Can this klass be a primary super? False for interfaces and arrays of
203 // interfaces. False also for arrays or classes with long super chains.
204 bool can_be_primary_super() const {
205 const juint secondary_offset = in_bytes(secondary_super_cache_offset());
206 return super_check_offset() != secondary_offset;
207 }
208 virtual bool can_be_primary_super_slow() const;
209
210 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit].
211 juint super_depth() const {
212 if (!can_be_primary_super()) {
213 return primary_super_limit();
214 } else {
215 juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*);
216 assert(d < primary_super_limit(), "oob");
217 assert(_primary_supers[d] == this, "proper init");
218 return d;
219 }
220 }
221
222 // store an oop into a field of a Klass
223 void klass_oop_store(oop* p, oop v);
224 void klass_oop_store(volatile oop* p, oop v);
225
226 // java mirror
227 oop java_mirror() const { return _java_mirror; }
228 void set_java_mirror(oop m) { klass_oop_store(&_java_mirror, m); }
229
230 // modifier flags
231 jint modifier_flags() const { return _modifier_flags; }
232 void set_modifier_flags(jint flags) { _modifier_flags = flags; }
233
234 // size helper
235 int layout_helper() const { return _layout_helper; }
236 void set_layout_helper(int lh) { _layout_helper = lh; }
237
238 // Note: for instances layout_helper() may include padding.
239 // Use InstanceKlass::contains_field_offset to classify field offsets.
240
241 // sub/superklass links
242 Klass* subklass() const { return _subklass; }
243 Klass* next_sibling() const { return _next_sibling; }
244 InstanceKlass* superklass() const;
245 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list
246
247 void set_next_link(Klass* k) { _next_link = k; }
248 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader.
249
250 // class loader data
251 ClassLoaderData* class_loader_data() const { return _class_loader_data; }
252 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; }
253
254 // The Klasses are not placed in the Heap, so the Card Table or
255 // the Mod Union Table can't be used to mark when klasses have modified oops.
256 // The CT and MUT bits saves this information for the individual Klasses.
257 void record_modified_oops() { _modified_oops = 1; }
258 void clear_modified_oops() { _modified_oops = 0; }
259 bool has_modified_oops() { return _modified_oops == 1; }
260
261 void accumulate_modified_oops() { if (has_modified_oops()) _accumulated_modified_oops = 1; }
262 void clear_accumulated_modified_oops() { _accumulated_modified_oops = 0; }
263 bool has_accumulated_modified_oops() { return _accumulated_modified_oops == 1; }
264
265 int shared_classpath_index() const {
266 return _shared_class_path_index;
267 };
268
269 void set_shared_classpath_index(int index) {
270 _shared_class_path_index = index;
271 };
272
273
274 protected: // internal accessors
275 void set_subklass(Klass* s);
276 void set_next_sibling(Klass* s);
277
278 public:
279
280 // Compiler support
281 static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); }
282 static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); }
283 static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); }
284 static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); }
285 static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); }
286 static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); }
287 static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); }
288 static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); }
289 static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); }
290
291 // Unpacking layout_helper:
292 enum {
293 _lh_neutral_value = 0, // neutral non-array non-instance value
294 _lh_instance_slow_path_bit = 0x01,
295 _lh_log2_element_size_shift = BitsPerByte*0,
296 _lh_log2_element_size_mask = BitsPerLong-1,
297 _lh_element_type_shift = BitsPerByte*1,
298 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask
299 _lh_header_size_shift = BitsPerByte*2,
300 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask
301 _lh_array_tag_bits = 2,
302 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits,
303 _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30
304 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30
305 };
306
307 static int layout_helper_size_in_bytes(jint lh) {
308 assert(lh > (jint)_lh_neutral_value, "must be instance");
309 return (int) lh & ~_lh_instance_slow_path_bit;
310 }
311 static bool layout_helper_needs_slow_path(jint lh) {
312 assert(lh > (jint)_lh_neutral_value, "must be instance");
313 return (lh & _lh_instance_slow_path_bit) != 0;
314 }
315 static bool layout_helper_is_instance(jint lh) {
316 return (jint)lh > (jint)_lh_neutral_value;
317 }
318 static bool layout_helper_is_array(jint lh) {
319 return (jint)lh < (jint)_lh_neutral_value;
320 }
321 static bool layout_helper_is_typeArray(jint lh) {
322 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift);
323 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift);
324 }
325 static bool layout_helper_is_objArray(jint lh) {
326 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift);
327 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift);
328 }
329 static int layout_helper_header_size(jint lh) {
330 assert(lh < (jint)_lh_neutral_value, "must be array");
331 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask;
332 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity");
333 return hsize;
334 }
335 static BasicType layout_helper_element_type(jint lh) {
336 assert(lh < (jint)_lh_neutral_value, "must be array");
337 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask;
338 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity");
339 return (BasicType) btvalue;
340 }
341 static int layout_helper_log2_element_size(jint lh) {
342 assert(lh < (jint)_lh_neutral_value, "must be array");
343 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask;
344 assert(l2esz <= LogBitsPerLong,
345 "sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh);
346 return l2esz;
347 }
348 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) {
349 return (tag << _lh_array_tag_shift)
350 | (hsize << _lh_header_size_shift)
351 | ((int)etype << _lh_element_type_shift)
352 | (log2_esize << _lh_log2_element_size_shift);
353 }
354 static jint instance_layout_helper(jint size, bool slow_path_flag) {
355 return (size << LogHeapWordSize)
356 | (slow_path_flag ? _lh_instance_slow_path_bit : 0);
357 }
358 static int layout_helper_to_size_helper(jint lh) {
359 assert(lh > (jint)_lh_neutral_value, "must be instance");
360 // Note that the following expression discards _lh_instance_slow_path_bit.
361 return lh >> LogHeapWordSize;
362 }
363 // Out-of-line version computes everything based on the etype:
364 static jint array_layout_helper(BasicType etype);
365
366 // What is the maximum number of primary superclasses any klass can have?
367 #ifdef PRODUCT
368 static juint primary_super_limit() { return _primary_super_limit; }
369 #else
370 static juint primary_super_limit() {
371 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob");
372 return FastSuperclassLimit;
373 }
374 #endif
375
376 // vtables
377 virtual klassVtable* vtable() const = 0;
378 virtual int vtable_length() const = 0;
379
380 // subclass check
381 bool is_subclass_of(const Klass* k) const;
382 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it
383 bool is_subtype_of(Klass* k) const {
384 juint off = k->super_check_offset();
385 Klass* sup = *(Klass**)( (address)this + off );
386 const juint secondary_offset = in_bytes(secondary_super_cache_offset());
387 if (sup == k) {
388 return true;
389 } else if (off != secondary_offset) {
390 return false;
391 } else {
392 return search_secondary_supers(k);
393 }
394 }
395 bool search_secondary_supers(Klass* k) const;
396
397 // Find LCA in class hierarchy
398 Klass *LCA( Klass *k );
399
400 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
401 // if not, throw either an Error or an Exception.
402 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
403
404 // array copying
405 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
406
407 // tells if the class should be initialized
408 virtual bool should_be_initialized() const { return false; }
409 // initializes the klass
410 virtual void initialize(TRAPS);
411 // lookup operation for MethodLookupCache
412 friend class MethodLookupCache;
413 virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const;
414 virtual Method* uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const;
415 public:
416 Method* lookup_method(const Symbol* name, const Symbol* signature) const {
417 return uncached_lookup_method(name, signature, find_overpass);
418 }
419
420 // array class with specific rank
421 Klass* array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); }
422
423 // array class with this klass as element type
424 Klass* array_klass(TRAPS) { return array_klass_impl(false, THREAD); }
425
426 // These will return NULL instead of allocating on the heap:
427 // NB: these can block for a mutex, like other functions with TRAPS arg.
428 Klass* array_klass_or_null(int rank);
429 Klass* array_klass_or_null();
430
431 virtual oop protection_domain() const = 0;
432
433 oop class_loader() const;
434
435 virtual oop klass_holder() const { return class_loader(); }
436
437 protected:
438 virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS);
439 virtual Klass* array_klass_impl(bool or_null, TRAPS);
440
441 public:
442 // CDS support - remove and restore oops from metadata. Oops are not shared.
443 virtual void remove_unshareable_info();
444 virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
445
446 protected:
447 // computes the subtype relationship
448 virtual bool compute_is_subtype_of(Klass* k);
449 public:
450 // subclass accessor (here for convenience; undefined for non-klass objects)
451 virtual bool is_leaf_class() const { fatal("not a class"); return false; }
452 public:
453 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP
454 // These functions describe behavior for the oop not the KLASS.
455
456 // actual oop size of obj in memory
457 virtual int oop_size(oop obj) const = 0;
458
459 // Size of klass in word size.
460 virtual int size() const = 0;
461 #if INCLUDE_SERVICES
462 virtual void collect_statistics(KlassSizeStats *sz) const;
463 #endif
464
465 // Returns the Java name for a class (Resource allocated)
466 // For arrays, this returns the name of the element with a leading '['.
467 // For classes, this returns the name with the package separators
468 // turned into '.'s.
469 const char* external_name() const;
470 // Returns the name for a class (Resource allocated) as the class
471 // would appear in a signature.
472 // For arrays, this returns the name of the element with a leading '['.
473 // For classes, this returns the name with a leading 'L' and a trailing ';'
474 // and the package separators as '/'.
475 virtual const char* signature_name() const;
476
477 // type testing operations
478 #ifdef ASSERT
479 protected:
480 virtual bool is_instance_klass_slow() const { return false; }
481 virtual bool is_array_klass_slow() const { return false; }
482 virtual bool is_objArray_klass_slow() const { return false; }
483 virtual bool is_typeArray_klass_slow() const { return false; }
484 #endif // ASSERT
485 public:
486
487 // Fast non-virtual versions
488 #ifndef ASSERT
489 #define assert_same_query(xval, xcheck) xval
490 #else
491 private:
492 static bool assert_same_query(bool xval, bool xslow) {
493 assert(xval == xslow, "slow and fast queries agree");
494 return xval;
495 }
496 public:
497 #endif
498 inline bool is_instance_klass() const { return assert_same_query(
499 layout_helper_is_instance(layout_helper()),
500 is_instance_klass_slow()); }
501 inline bool is_array_klass() const { return assert_same_query(
502 layout_helper_is_array(layout_helper()),
503 is_array_klass_slow()); }
504 inline bool is_objArray_klass() const { return assert_same_query(
505 layout_helper_is_objArray(layout_helper()),
506 is_objArray_klass_slow()); }
507 inline bool is_typeArray_klass() const { return assert_same_query(
508 layout_helper_is_typeArray(layout_helper()),
509 is_typeArray_klass_slow()); }
510 #undef assert_same_query
511
512 // Access flags
513 AccessFlags access_flags() const { return _access_flags; }
514 void set_access_flags(AccessFlags flags) { _access_flags = flags; }
515
516 bool is_public() const { return _access_flags.is_public(); }
517 bool is_final() const { return _access_flags.is_final(); }
518 bool is_interface() const { return _access_flags.is_interface(); }
519 bool is_abstract() const { return _access_flags.is_abstract(); }
520 bool is_super() const { return _access_flags.is_super(); }
521 bool is_synthetic() const { return _access_flags.is_synthetic(); }
522 void set_is_synthetic() { _access_flags.set_is_synthetic(); }
523 bool has_finalizer() const { return _access_flags.has_finalizer(); }
524 bool has_final_method() const { return _access_flags.has_final_method(); }
525 void set_has_finalizer() { _access_flags.set_has_finalizer(); }
526 void set_has_final_method() { _access_flags.set_has_final_method(); }
527 bool is_cloneable() const { return _access_flags.is_cloneable(); }
528 void set_is_cloneable() { _access_flags.set_is_cloneable(); }
529 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); }
530 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); }
531 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); }
532 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); }
533
534 // Biased locking support
535 // Note: the prototype header is always set up to be at least the
536 // prototype markOop. If biased locking is enabled it may further be
537 // biasable and have an epoch.
538 markOop prototype_header() const { return _prototype_header; }
539 // NOTE: once instances of this klass are floating around in the
540 // system, this header must only be updated at a safepoint.
541 // NOTE 2: currently we only ever set the prototype header to the
542 // biasable prototype for instanceKlasses. There is no technical
543 // reason why it could not be done for arrayKlasses aside from
544 // wanting to reduce the initial scope of this optimization. There
545 // are potential problems in setting the bias pattern for
546 // JVM-internal oops.
547 inline void set_prototype_header(markOop header);
548 static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); }
549
550 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; }
551 // Atomically increments biased_lock_revocation_count and returns updated value
552 int atomic_incr_biased_lock_revocation_count();
553 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; }
554 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; }
555 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; }
556
557 TRACE_DEFINE_KLASS_METHODS;
558
559 // garbage collection support
560 void oops_do(OopClosure* cl);
561
562 // Iff the class loader (or mirror for anonymous classes) is alive the
563 // Klass is considered alive.
564 // The is_alive closure passed in depends on the Garbage Collector used.
565 bool is_loader_alive(BoolObjectClosure* is_alive);
566
567 static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true);
568 static void clean_subklass_tree(BoolObjectClosure* is_alive) {
569 clean_weak_klass_links(is_alive, false /* clean_alive_klasses */);
570 }
571
572 // GC specific object visitors
573 //
574 // Mark Sweep
575 virtual int oop_ms_adjust_pointers(oop obj) = 0;
576 #if INCLUDE_ALL_GCS
577 // Parallel Scavenge
578 virtual void oop_ps_push_contents( oop obj, PSPromotionManager* pm) = 0;
579 // Parallel Compact
580 virtual void oop_pc_follow_contents(oop obj, ParCompactionManager* cm) = 0;
581 virtual void oop_pc_update_pointers(oop obj) = 0;
582 #endif
583
584 // Iterators specialized to particular subtypes
585 // of ExtendedOopClosure, to avoid closure virtual calls.
586 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
587 virtual void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) = 0; \
588 /* Iterates "closure" over all the oops in "obj" (of type "this") within "mr". */ \
589 virtual void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) = 0;
590
591 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL)
592 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL)
593
594 #if INCLUDE_ALL_GCS
595 #define Klass_OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \
596 virtual void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) = 0;
597
598 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
599 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
600 #endif // INCLUDE_ALL_GCS
601
602 virtual void array_klasses_do(void f(Klass* k)) {}
603
604 // Return self, except for abstract classes with exactly 1
605 // implementor. Then return the 1 concrete implementation.
606 Klass *up_cast_abstract();
607
608 // klass name
609 Symbol* name() const { return _name; }
610 void set_name(Symbol* n);
611
612 public:
613 // jvm support
614 virtual jint compute_modifier_flags(TRAPS) const;
615
616 // JVMTI support
617 virtual jint jvmti_class_status() const;
618
619 // Printing
620 virtual void print_on(outputStream* st) const;
621
622 virtual void oop_print_value_on(oop obj, outputStream* st);
623 virtual void oop_print_on (oop obj, outputStream* st);
624
625 virtual const char* internal_name() const = 0;
626
627 // Verification
628 virtual void verify_on(outputStream* st);
629 void verify() { verify_on(tty); }
630
631 #ifndef PRODUCT
632 bool verify_vtable_index(int index);
633 bool verify_itable_index(int index);
634 #endif
635
636 virtual void oop_verify_on(oop obj, outputStream* st);
637
638 static bool is_null(narrowKlass obj);
639 static bool is_null(Klass* obj);
640
641 // klass encoding for klass pointer in objects.
642 static narrowKlass encode_klass_not_null(Klass* v);
643 static narrowKlass encode_klass(Klass* v);
644
645 static Klass* decode_klass_not_null(narrowKlass v);
646 static Klass* decode_klass(narrowKlass v);
647
648 private:
649 // barriers used by klass_oop_store
650 void klass_update_barrier_set(oop v);
651 void klass_update_barrier_set_pre(oop* p, oop v);
652 };
653
654 // Helper to convert the oop iterate macro suffixes into bool values that can be used by template functions.
655 #define nvs_nv_to_bool true
656 #define nvs_v_to_bool false
657 #define nvs_to_bool(nv_suffix) nvs##nv_suffix##_to_bool
658
659 // Oop iteration macros for declarations.
660 // Used to generate declarations in the *Klass header files.
661
662 #define OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
663 void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure); \
664 void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr);
665
666 #if INCLUDE_ALL_GCS
667 #define OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \
668 void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure);
669 #endif // INCLUDE_ALL_GCS
670
671
672 // Oop iteration macros for definitions.
673 // Used to generate definitions in the *Klass.inline.hpp files.
674
675 #define OOP_OOP_ITERATE_DEFN(KlassType, OopClosureType, nv_suffix) \
676 void KlassType::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
677 oop_oop_iterate<nvs_to_bool(nv_suffix)>(obj, closure); \
678 }
679
680 #if INCLUDE_ALL_GCS
681 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix) \
682 void KlassType::oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) { \
683 oop_oop_iterate_reverse<nvs_to_bool(nv_suffix)>(obj, closure); \
684 }
685 #else
686 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix)
687 #endif
688
689 #define OOP_OOP_ITERATE_DEFN_BOUNDED(KlassType, OopClosureType, nv_suffix) \
690 void KlassType::oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) { \
691 oop_oop_iterate_bounded<nvs_to_bool(nv_suffix)>(obj, closure, mr); \
692 }
693
694 #endif // SHARE_VM_OOPS_KLASS_HPP