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 *
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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 "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 TRACE_DEFINE_KLASS_TRACE_ID;
135
136 // Biased locking implementation and statistics
137 // (the 64-bit chunk goes first, to avoid some fragmentation)
138 jlong _last_biased_lock_bulk_revocation_time;
139 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type
140 jint _biased_lock_revocation_count;
141
142 // vtable length
143 int _vtable_len;
144
145 // Remembered sets support for the oops in the klasses.
146 jbyte _modified_oops; // Card Table Equivalent (YC/CMS support)
147 jbyte _accumulated_modified_oops; // Mod Union Equivalent (CMS support)
148
149 private:
150 // This is an index into FileMapHeader::_classpath_entry_table[], to
151 // associate this class with the JAR file where it's loaded from during
152 // dump time. If a class is not loaded from the shared archive, this field is
153 // -1.
154 jshort _shared_class_path_index;
155
156 friend class SharedClassUtil;
157 protected:
158
159 // Constructor
160 Klass();
161
162 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw();
163
164 public:
165 enum DefaultsLookupMode { find_defaults, skip_defaults };
166 enum OverpassLookupMode { find_overpass, skip_overpass };
167 enum StaticLookupMode { find_static, skip_static };
168 enum PrivateLookupMode { find_private, skip_private };
169
170 bool is_klass() const volatile { return true; }
171
172 // super
173 Klass* super() const { return _super; }
174 void set_super(Klass* k) { _super = k; }
175
176 // initializes _super link, _primary_supers & _secondary_supers arrays
177 void initialize_supers(Klass* k, TRAPS);
178 void initialize_supers_impl1(Klass* k);
179 void initialize_supers_impl2(Klass* k);
180
181 // klass-specific helper for initializing _secondary_supers
182 virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
183
184 // java_super is the Java-level super type as specified by Class.getSuperClass.
185 virtual Klass* java_super() const { return NULL; }
186
187 juint super_check_offset() const { return _super_check_offset; }
188 void set_super_check_offset(juint o) { _super_check_offset = o; }
189
190 Klass* secondary_super_cache() const { return _secondary_super_cache; }
191 void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; }
192
193 Array<Klass*>* secondary_supers() const { return _secondary_supers; }
194 void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; }
195
196 // Return the element of the _super chain of the given depth.
197 // If there is no such element, return either NULL or this.
198 Klass* primary_super_of_depth(juint i) const {
199 assert(i < primary_super_limit(), "oob");
200 Klass* super = _primary_supers[i];
201 assert(super == NULL || super->super_depth() == i, "correct display");
202 return super;
203 }
204
205 // Can this klass be a primary super? False for interfaces and arrays of
206 // interfaces. False also for arrays or classes with long super chains.
207 bool can_be_primary_super() const {
208 const juint secondary_offset = in_bytes(secondary_super_cache_offset());
209 return super_check_offset() != secondary_offset;
210 }
211 virtual bool can_be_primary_super_slow() const;
212
213 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit].
214 juint super_depth() const {
215 if (!can_be_primary_super()) {
216 return primary_super_limit();
217 } else {
218 juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*);
219 assert(d < primary_super_limit(), "oob");
220 assert(_primary_supers[d] == this, "proper init");
221 return d;
222 }
223 }
224
225 // store an oop into a field of a Klass
226 void klass_oop_store(oop* p, oop v);
227 void klass_oop_store(volatile oop* p, oop v);
228
229 // java mirror
230 oop java_mirror() const { return _java_mirror; }
231 void set_java_mirror(oop m) { klass_oop_store(&_java_mirror, m); }
232
233 // modifier flags
234 jint modifier_flags() const { return _modifier_flags; }
235 void set_modifier_flags(jint flags) { _modifier_flags = flags; }
236
237 // size helper
238 int layout_helper() const { return _layout_helper; }
239 void set_layout_helper(int lh) { _layout_helper = lh; }
240
241 // Note: for instances layout_helper() may include padding.
242 // Use InstanceKlass::contains_field_offset to classify field offsets.
243
244 // sub/superklass links
245 Klass* subklass() const { return _subklass; }
246 Klass* next_sibling() const { return _next_sibling; }
247 InstanceKlass* superklass() const;
248 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list
249
250 void set_next_link(Klass* k) { _next_link = k; }
251 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader.
252
253 // class loader data
254 ClassLoaderData* class_loader_data() const { return _class_loader_data; }
255 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; }
256
257 // The Klasses are not placed in the Heap, so the Card Table or
258 // the Mod Union Table can't be used to mark when klasses have modified oops.
259 // The CT and MUT bits saves this information for the individual Klasses.
260 void record_modified_oops() { _modified_oops = 1; }
261 void clear_modified_oops() { _modified_oops = 0; }
262 bool has_modified_oops() { return _modified_oops == 1; }
263
264 void accumulate_modified_oops() { if (has_modified_oops()) _accumulated_modified_oops = 1; }
265 void clear_accumulated_modified_oops() { _accumulated_modified_oops = 0; }
266 bool has_accumulated_modified_oops() { return _accumulated_modified_oops == 1; }
267
268 int shared_classpath_index() const {
269 return _shared_class_path_index;
270 };
271
272 void set_shared_classpath_index(int index) {
273 _shared_class_path_index = index;
274 };
275
276
277 protected: // internal accessors
278 void set_subklass(Klass* s);
279 void set_next_sibling(Klass* s);
280
281 public:
282
283 // Compiler support
284 static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); }
285 static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); }
286 static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); }
287 static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); }
288 static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); }
289 static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); }
290 static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); }
291 static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); }
292 static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); }
293
294 // Unpacking layout_helper:
295 enum {
296 _lh_neutral_value = 0, // neutral non-array non-instance value
297 _lh_instance_slow_path_bit = 0x01,
298 _lh_log2_element_size_shift = BitsPerByte*0,
299 _lh_log2_element_size_mask = BitsPerLong-1,
300 _lh_element_type_shift = BitsPerByte*1,
301 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask
302 _lh_header_size_shift = BitsPerByte*2,
303 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask
304 _lh_array_tag_bits = 2,
305 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits,
306 _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30
307 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30
308 };
309
310 static int layout_helper_size_in_bytes(jint lh) {
311 assert(lh > (jint)_lh_neutral_value, "must be instance");
312 return (int) lh & ~_lh_instance_slow_path_bit;
313 }
314 static bool layout_helper_needs_slow_path(jint lh) {
315 assert(lh > (jint)_lh_neutral_value, "must be instance");
316 return (lh & _lh_instance_slow_path_bit) != 0;
317 }
318 static bool layout_helper_is_instance(jint lh) {
319 return (jint)lh > (jint)_lh_neutral_value;
320 }
321 static bool layout_helper_is_array(jint lh) {
322 return (jint)lh < (jint)_lh_neutral_value;
323 }
324 static bool layout_helper_is_typeArray(jint lh) {
325 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift);
326 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift);
327 }
328 static bool layout_helper_is_objArray(jint lh) {
329 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift);
330 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift);
331 }
332 static int layout_helper_header_size(jint lh) {
333 assert(lh < (jint)_lh_neutral_value, "must be array");
334 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask;
335 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity");
336 return hsize;
337 }
338 static BasicType layout_helper_element_type(jint lh) {
339 assert(lh < (jint)_lh_neutral_value, "must be array");
340 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask;
341 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity");
342 return (BasicType) btvalue;
343 }
344 static int layout_helper_log2_element_size(jint lh) {
345 assert(lh < (jint)_lh_neutral_value, "must be array");
346 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask;
347 assert(l2esz <= LogBitsPerLong,
348 "sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh);
349 return l2esz;
350 }
351 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) {
352 return (tag << _lh_array_tag_shift)
353 | (hsize << _lh_header_size_shift)
354 | ((int)etype << _lh_element_type_shift)
355 | (log2_esize << _lh_log2_element_size_shift);
356 }
357 static jint instance_layout_helper(jint size, bool slow_path_flag) {
358 return (size << LogHeapWordSize)
359 | (slow_path_flag ? _lh_instance_slow_path_bit : 0);
360 }
361 static int layout_helper_to_size_helper(jint lh) {
362 assert(lh > (jint)_lh_neutral_value, "must be instance");
363 // Note that the following expression discards _lh_instance_slow_path_bit.
364 return lh >> LogHeapWordSize;
365 }
366 // Out-of-line version computes everything based on the etype:
367 static jint array_layout_helper(BasicType etype);
368
369 // What is the maximum number of primary superclasses any klass can have?
370 #ifdef PRODUCT
371 static juint primary_super_limit() { return _primary_super_limit; }
372 #else
373 static juint primary_super_limit() {
374 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob");
375 return FastSuperclassLimit;
376 }
377 #endif
378
379 // vtables
380 virtual klassVtable* vtable() const = 0;
381 int vtable_length() const { return _vtable_len; }
382
383 // subclass check
384 bool is_subclass_of(const Klass* k) const;
385 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it
386 bool is_subtype_of(Klass* k) const {
387 juint off = k->super_check_offset();
388 Klass* sup = *(Klass**)( (address)this + off );
389 const juint secondary_offset = in_bytes(secondary_super_cache_offset());
390 if (sup == k) {
391 return true;
392 } else if (off != secondary_offset) {
393 return false;
394 } else {
395 return search_secondary_supers(k);
396 }
397 }
398 bool search_secondary_supers(Klass* k) const;
399
400 // Find LCA in class hierarchy
401 Klass *LCA( Klass *k );
402
403 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
404 // if not, throw either an Error or an Exception.
405 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
406
407 // array copying
408 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
409
410 // tells if the class should be initialized
411 virtual bool should_be_initialized() const { return false; }
412 // initializes the klass
413 virtual void initialize(TRAPS);
414 // lookup operation for MethodLookupCache
415 friend class MethodLookupCache;
416 virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const;
417 virtual Method* uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const;
418 public:
419 Method* lookup_method(const Symbol* name, const Symbol* signature) const {
420 return uncached_lookup_method(name, signature, find_overpass);
421 }
422
423 // array class with specific rank
424 Klass* array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); }
425
426 // array class with this klass as element type
427 Klass* array_klass(TRAPS) { return array_klass_impl(false, THREAD); }
428
429 // These will return NULL instead of allocating on the heap:
430 // NB: these can block for a mutex, like other functions with TRAPS arg.
431 Klass* array_klass_or_null(int rank);
432 Klass* array_klass_or_null();
433
434 virtual oop protection_domain() const = 0;
435
436 oop class_loader() const;
437
438 virtual oop klass_holder() const { return class_loader(); }
439
440 protected:
441 virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS);
442 virtual Klass* array_klass_impl(bool or_null, TRAPS);
443
444 void set_vtable_length(int len) { _vtable_len= len; }
445
446 public:
447 static ByteSize vtable_start_offset();
448 static ByteSize vtable_length_offset() {
449 return byte_offset_of(Klass, _vtable_len);
450 }
451
452 // CDS support - remove and restore oops from metadata. Oops are not shared.
453 virtual void remove_unshareable_info();
454 virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
455
456 protected:
457 // computes the subtype relationship
458 virtual bool compute_is_subtype_of(Klass* k);
459 public:
460 // subclass accessor (here for convenience; undefined for non-klass objects)
461 virtual bool is_leaf_class() const { fatal("not a class"); return false; }
462 public:
463 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP
464 // These functions describe behavior for the oop not the KLASS.
465
466 // actual oop size of obj in memory
467 virtual int oop_size(oop obj) const = 0;
468
469 // Size of klass in word size.
470 virtual int size() const = 0;
471 #if INCLUDE_SERVICES
472 virtual void collect_statistics(KlassSizeStats *sz) const;
473 #endif
474
475 // Returns the Java name for a class (Resource allocated)
476 // For arrays, this returns the name of the element with a leading '['.
477 // For classes, this returns the name with the package separators
478 // turned into '.'s.
479 const char* external_name() const;
480 // Returns the name for a class (Resource allocated) as the class
481 // would appear in a signature.
482 // For arrays, this returns the name of the element with a leading '['.
483 // For classes, this returns the name with a leading 'L' and a trailing ';'
484 // and the package separators as '/'.
485 virtual const char* signature_name() const;
486
487 // type testing operations
488 #ifdef ASSERT
489 protected:
490 virtual bool is_instance_klass_slow() const { return false; }
491 virtual bool is_array_klass_slow() const { return false; }
492 virtual bool is_objArray_klass_slow() const { return false; }
493 virtual bool is_typeArray_klass_slow() const { return false; }
494 #endif // ASSERT
495 public:
496
497 // Fast non-virtual versions
498 #ifndef ASSERT
499 #define assert_same_query(xval, xcheck) xval
500 #else
501 private:
502 static bool assert_same_query(bool xval, bool xslow) {
503 assert(xval == xslow, "slow and fast queries agree");
504 return xval;
505 }
506 public:
507 #endif
508 inline bool is_instance_klass() const { return assert_same_query(
509 layout_helper_is_instance(layout_helper()),
510 is_instance_klass_slow()); }
511 inline bool is_array_klass() const { return assert_same_query(
512 layout_helper_is_array(layout_helper()),
513 is_array_klass_slow()); }
514 inline bool is_objArray_klass() const { return assert_same_query(
515 layout_helper_is_objArray(layout_helper()),
516 is_objArray_klass_slow()); }
517 inline bool is_typeArray_klass() const { return assert_same_query(
518 layout_helper_is_typeArray(layout_helper()),
519 is_typeArray_klass_slow()); }
520 #undef assert_same_query
521
522 // Access flags
523 AccessFlags access_flags() const { return _access_flags; }
524 void set_access_flags(AccessFlags flags) { _access_flags = flags; }
525
526 bool is_public() const { return _access_flags.is_public(); }
527 bool is_final() const { return _access_flags.is_final(); }
528 bool is_interface() const { return _access_flags.is_interface(); }
529 bool is_abstract() const { return _access_flags.is_abstract(); }
530 bool is_super() const { return _access_flags.is_super(); }
531 bool is_synthetic() const { return _access_flags.is_synthetic(); }
532 void set_is_synthetic() { _access_flags.set_is_synthetic(); }
533 bool has_finalizer() const { return _access_flags.has_finalizer(); }
534 bool has_final_method() const { return _access_flags.has_final_method(); }
535 void set_has_finalizer() { _access_flags.set_has_finalizer(); }
536 void set_has_final_method() { _access_flags.set_has_final_method(); }
537 bool is_cloneable() const { return _access_flags.is_cloneable(); }
538 void set_is_cloneable() { _access_flags.set_is_cloneable(); }
539 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); }
540 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); }
541 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); }
542 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); }
543
544 // Biased locking support
545 // Note: the prototype header is always set up to be at least the
546 // prototype markOop. If biased locking is enabled it may further be
547 // biasable and have an epoch.
548 markOop prototype_header() const { return _prototype_header; }
549 // NOTE: once instances of this klass are floating around in the
550 // system, this header must only be updated at a safepoint.
551 // NOTE 2: currently we only ever set the prototype header to the
552 // biasable prototype for instanceKlasses. There is no technical
553 // reason why it could not be done for arrayKlasses aside from
554 // wanting to reduce the initial scope of this optimization. There
555 // are potential problems in setting the bias pattern for
556 // JVM-internal oops.
557 inline void set_prototype_header(markOop header);
558 static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); }
559
560 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; }
561 // Atomically increments biased_lock_revocation_count and returns updated value
562 int atomic_incr_biased_lock_revocation_count();
563 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; }
564 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; }
565 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; }
566
567 TRACE_DEFINE_KLASS_METHODS;
568
569 // garbage collection support
570 void oops_do(OopClosure* cl);
571
572 // Iff the class loader (or mirror for anonymous classes) is alive the
573 // Klass is considered alive.
574 // The is_alive closure passed in depends on the Garbage Collector used.
575 bool is_loader_alive(BoolObjectClosure* is_alive);
576
577 static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true);
578 static void clean_subklass_tree(BoolObjectClosure* is_alive) {
579 clean_weak_klass_links(is_alive, false /* clean_alive_klasses */);
580 }
581
582 // GC specific object visitors
583 //
584 // Mark Sweep
585 virtual int oop_ms_adjust_pointers(oop obj) = 0;
586 #if INCLUDE_ALL_GCS
587 // Parallel Scavenge
588 virtual void oop_ps_push_contents( oop obj, PSPromotionManager* pm) = 0;
589 // Parallel Compact
590 virtual void oop_pc_follow_contents(oop obj, ParCompactionManager* cm) = 0;
591 virtual void oop_pc_update_pointers(oop obj) = 0;
592 #endif
593
594 // Iterators specialized to particular subtypes
595 // of ExtendedOopClosure, to avoid closure virtual calls.
596 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
597 virtual void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) = 0; \
598 /* Iterates "closure" over all the oops in "obj" (of type "this") within "mr". */ \
599 virtual void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) = 0;
600
601 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL)
602 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL)
603
604 #if INCLUDE_ALL_GCS
605 #define Klass_OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \
606 virtual void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) = 0;
607
608 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
609 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
610 #endif // INCLUDE_ALL_GCS
611
612 virtual void array_klasses_do(void f(Klass* k)) {}
613
614 // Return self, except for abstract classes with exactly 1
615 // implementor. Then return the 1 concrete implementation.
616 Klass *up_cast_abstract();
617
618 // klass name
619 Symbol* name() const { return _name; }
620 void set_name(Symbol* n);
621
622 public:
623 // jvm support
624 virtual jint compute_modifier_flags(TRAPS) const;
625
626 // JVMTI support
627 virtual jint jvmti_class_status() const;
628
629 // Printing
630 virtual void print_on(outputStream* st) const;
631
632 virtual void oop_print_value_on(oop obj, outputStream* st);
633 virtual void oop_print_on (oop obj, outputStream* st);
634
635 virtual const char* internal_name() const = 0;
636
637 // Verification
638 virtual void verify_on(outputStream* st);
639 void verify() { verify_on(tty); }
640
641 #ifndef PRODUCT
642 bool verify_vtable_index(int index);
643 bool verify_itable_index(int index);
644 #endif
645
646 virtual void oop_verify_on(oop obj, outputStream* st);
647
648 static bool is_null(narrowKlass obj);
649 static bool is_null(Klass* obj);
650
651 // klass encoding for klass pointer in objects.
652 static narrowKlass encode_klass_not_null(Klass* v);
653 static narrowKlass encode_klass(Klass* v);
654
655 static Klass* decode_klass_not_null(narrowKlass v);
656 static Klass* decode_klass(narrowKlass v);
657
658 private:
659 // barriers used by klass_oop_store
660 void klass_update_barrier_set(oop v);
661 void klass_update_barrier_set_pre(oop* p, oop v);
662 };
663
664 // Helper to convert the oop iterate macro suffixes into bool values that can be used by template functions.
665 #define nvs_nv_to_bool true
666 #define nvs_v_to_bool false
667 #define nvs_to_bool(nv_suffix) nvs##nv_suffix##_to_bool
668
669 // Oop iteration macros for declarations.
670 // Used to generate declarations in the *Klass header files.
671
672 #define OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
673 void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure); \
674 void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr);
675
676 #if INCLUDE_ALL_GCS
677 #define OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \
678 void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure);
679 #endif // INCLUDE_ALL_GCS
680
681
682 // Oop iteration macros for definitions.
683 // Used to generate definitions in the *Klass.inline.hpp files.
684
685 #define OOP_OOP_ITERATE_DEFN(KlassType, OopClosureType, nv_suffix) \
686 void KlassType::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
687 oop_oop_iterate<nvs_to_bool(nv_suffix)>(obj, closure); \
688 }
689
690 #if INCLUDE_ALL_GCS
691 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix) \
692 void KlassType::oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) { \
693 oop_oop_iterate_reverse<nvs_to_bool(nv_suffix)>(obj, closure); \
694 }
695 #else
696 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix)
697 #endif
698
699 #define OOP_OOP_ITERATE_DEFN_BOUNDED(KlassType, OopClosureType, nv_suffix) \
700 void KlassType::oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) { \
701 oop_oop_iterate_bounded<nvs_to_bool(nv_suffix)>(obj, closure, mr); \
702 }
703
704 #endif // SHARE_VM_OOPS_KLASS_HPP