1 /*
2 * Copyright (c) 1997, 2014, 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.
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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
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23 */
24
25 #ifndef SHARE_VM_OOPS_KLASS_HPP
26 #define SHARE_VM_OOPS_KLASS_HPP
27
28 #include "memory/genOopClosures.hpp"
29 #include "memory/iterator.hpp"
30 #include "memory/memRegion.hpp"
31 #include "memory/specialized_oop_closures.hpp"
32 #include "oops/klassPS.hpp"
33 #include "oops/metadata.hpp"
34 #include "oops/oop.hpp"
35 #include "trace/traceMacros.hpp"
36 #include "utilities/accessFlags.hpp"
37 #include "utilities/macros.hpp"
38 #if INCLUDE_ALL_GCS
39 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp"
40 #include "gc_implementation/g1/g1OopClosures.hpp"
41 #include "gc_implementation/parNew/parOopClosures.hpp"
42 #endif // INCLUDE_ALL_GCS
43
44 //
45 // A Klass provides:
46 // 1: language level class object (method dictionary etc.)
47 // 2: provide vm dispatch behavior for the object
48 // Both functions are combined into one C++ class.
49
50 // One reason for the oop/klass dichotomy in the implementation is
51 // that we don't want a C++ vtbl pointer in every object. Thus,
52 // normal oops don't have any virtual functions. Instead, they
53 // forward all "virtual" functions to their klass, which does have
54 // a vtbl and does the C++ dispatch depending on the object's
55 // actual type. (See oop.inline.hpp for some of the forwarding code.)
56 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"!
57
58 // Forward declarations.
59 template <class T> class Array;
60 template <class T> class GrowableArray;
61 class ClassLoaderData;
62 class klassVtable;
63 class ParCompactionManager;
64 class KlassSizeStats;
65
66 class Klass : public Metadata {
67 friend class VMStructs;
68 protected:
69 // note: put frequently-used fields together at start of klass structure
70 // for better cache behavior (may not make much of a difference but sure won't hurt)
71 enum { _primary_super_limit = 8 };
72
73 // The "layout helper" is a combined descriptor of object layout.
74 // For klasses which are neither instance nor array, the value is zero.
75 //
76 // For instances, layout helper is a positive number, the instance size.
77 // This size is already passed through align_object_size and scaled to bytes.
78 // The low order bit is set if instances of this class cannot be
79 // allocated using the fastpath.
80 //
81 // For arrays, layout helper is a negative number, containing four
82 // distinct bytes, as follows:
83 // MSB:[tag, hsz, ebt, log2(esz)]:LSB
84 // where:
85 // tag is 0x80 if the elements are oops, 0xC0 if non-oops
86 // hsz is array header size in bytes (i.e., offset of first element)
87 // ebt is the BasicType of the elements
88 // esz is the element size in bytes
89 // This packed word is arranged so as to be quickly unpacked by the
90 // various fast paths that use the various subfields.
91 //
92 // The esz bits can be used directly by a SLL instruction, without masking.
93 //
94 // Note that the array-kind tag looks like 0x00 for instance klasses,
95 // since their length in bytes is always less than 24Mb.
96 //
97 // Final note: This comes first, immediately after C++ vtable,
98 // because it is frequently queried.
99 jint _layout_helper;
100
101 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers
102 // and _primary_supers all help make fast subtype checks. See big discussion
103 // in doc/server_compiler/checktype.txt
104 //
105 // Where to look to observe a supertype (it is &_secondary_super_cache for
106 // secondary supers, else is &_primary_supers[depth()].
107 juint _super_check_offset;
108
109 // Class name. Instance classes: java/lang/String, etc. Array classes: [I,
110 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes.
111 Symbol* _name;
112
113 // Cache of last observed secondary supertype
114 Klass* _secondary_super_cache;
115 // Array of all secondary supertypes
116 Array<Klass*>* _secondary_supers;
117 // Ordered list of all primary supertypes
118 Klass* _primary_supers[_primary_super_limit];
119 // java/lang/Class instance mirroring this class
120 oop _java_mirror;
121 // Superclass
122 Klass* _super;
123 // First subclass (NULL if none); _subklass->next_sibling() is next one
124 Klass* _subklass;
125 // Sibling link (or NULL); links all subklasses of a klass
126 Klass* _next_sibling;
127
128 // All klasses loaded by a class loader are chained through these links
129 Klass* _next_link;
130
131 // The VM's representation of the ClassLoader used to load this class.
132 // Provide access the corresponding instance java.lang.ClassLoader.
133 ClassLoaderData* _class_loader_data;
134
135 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers.
136 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here.
137
138 // Biased locking implementation and statistics
139 // (the 64-bit chunk goes first, to avoid some fragmentation)
140 jlong _last_biased_lock_bulk_revocation_time;
141 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type
142 jint _biased_lock_revocation_count;
143
144 TRACE_DEFINE_KLASS_TRACE_ID;
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 // Constructor
151 Klass();
152
153 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw();
154
155 public:
156 enum MethodLookupMode { normal, skip_overpass, skip_defaults };
157
158 bool is_klass() const volatile { return true; }
159
160 // super
161 Klass* super() const { return _super; }
162 void set_super(Klass* k) { _super = k; }
163
164 // initializes _super link, _primary_supers & _secondary_supers arrays
165 void initialize_supers(Klass* k, TRAPS);
166 void initialize_supers_impl1(Klass* k);
167 void initialize_supers_impl2(Klass* k);
168
169 // klass-specific helper for initializing _secondary_supers
170 virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
171
172 // java_super is the Java-level super type as specified by Class.getSuperClass.
173 virtual Klass* java_super() const { return NULL; }
174
175 juint super_check_offset() const { return _super_check_offset; }
176 void set_super_check_offset(juint o) { _super_check_offset = o; }
177
178 Klass* secondary_super_cache() const { return _secondary_super_cache; }
179 void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; }
180
181 Array<Klass*>* secondary_supers() const { return _secondary_supers; }
182 void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; }
183
184 // Return the element of the _super chain of the given depth.
185 // If there is no such element, return either NULL or this.
186 Klass* primary_super_of_depth(juint i) const {
187 assert(i < primary_super_limit(), "oob");
188 Klass* super = _primary_supers[i];
189 assert(super == NULL || super->super_depth() == i, "correct display");
190 return super;
191 }
192
193 // Can this klass be a primary super? False for interfaces and arrays of
194 // interfaces. False also for arrays or classes with long super chains.
195 bool can_be_primary_super() const {
196 const juint secondary_offset = in_bytes(secondary_super_cache_offset());
197 return super_check_offset() != secondary_offset;
198 }
199 virtual bool can_be_primary_super_slow() const;
200
201 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit].
202 juint super_depth() const {
203 if (!can_be_primary_super()) {
204 return primary_super_limit();
205 } else {
206 juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*);
207 assert(d < primary_super_limit(), "oob");
208 assert(_primary_supers[d] == this, "proper init");
209 return d;
210 }
211 }
212
213 // store an oop into a field of a Klass
214 void klass_oop_store(oop* p, oop v);
215 void klass_oop_store(volatile oop* p, oop v);
216
217 // java mirror
218 oop java_mirror() const { return _java_mirror; }
219 void set_java_mirror(oop m) { klass_oop_store(&_java_mirror, m); }
220
221 // modifier flags
222 jint modifier_flags() const { return _modifier_flags; }
223 void set_modifier_flags(jint flags) { _modifier_flags = flags; }
224
225 // size helper
226 int layout_helper() const { return _layout_helper; }
227 void set_layout_helper(int lh) { _layout_helper = lh; }
228
229 // Note: for instances layout_helper() may include padding.
230 // Use InstanceKlass::contains_field_offset to classify field offsets.
231
232 // sub/superklass links
233 Klass* subklass() const { return _subklass; }
234 Klass* next_sibling() const { return _next_sibling; }
235 InstanceKlass* superklass() const;
236 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list
237
238 void set_next_link(Klass* k) { _next_link = k; }
239 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader.
240
241 // class loader data
242 ClassLoaderData* class_loader_data() const { return _class_loader_data; }
243 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; }
244
245 // The Klasses are not placed in the Heap, so the Card Table or
246 // the Mod Union Table can't be used to mark when klasses have modified oops.
247 // The CT and MUT bits saves this information for the individual Klasses.
248 void record_modified_oops() { _modified_oops = 1; }
249 void clear_modified_oops() { _modified_oops = 0; }
250 bool has_modified_oops() { return _modified_oops == 1; }
251
252 void accumulate_modified_oops() { if (has_modified_oops()) _accumulated_modified_oops = 1; }
253 void clear_accumulated_modified_oops() { _accumulated_modified_oops = 0; }
254 bool has_accumulated_modified_oops() { return _accumulated_modified_oops == 1; }
255
256 protected: // internal accessors
257 void set_subklass(Klass* s);
258 void set_next_sibling(Klass* s);
259
260 public:
261
262 // Compiler support
263 static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); }
264 static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); }
265 static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); }
266 static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); }
267 static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); }
268 static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); }
269 static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); }
270 static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); }
271 static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); }
272
273 // Unpacking layout_helper:
274 enum {
275 _lh_neutral_value = 0, // neutral non-array non-instance value
276 _lh_instance_slow_path_bit = 0x01,
277 _lh_log2_element_size_shift = BitsPerByte*0,
278 _lh_log2_element_size_mask = BitsPerLong-1,
279 _lh_element_type_shift = BitsPerByte*1,
280 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask
281 _lh_header_size_shift = BitsPerByte*2,
282 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask
283 _lh_array_tag_bits = 2,
284 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits,
285 _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30
286 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30
287 };
288
289 static int layout_helper_size_in_bytes(jint lh) {
290 assert(lh > (jint)_lh_neutral_value, "must be instance");
291 return (int) lh & ~_lh_instance_slow_path_bit;
292 }
293 static bool layout_helper_needs_slow_path(jint lh) {
294 assert(lh > (jint)_lh_neutral_value, "must be instance");
295 return (lh & _lh_instance_slow_path_bit) != 0;
296 }
297 static bool layout_helper_is_instance(jint lh) {
298 return (jint)lh > (jint)_lh_neutral_value;
299 }
300 static bool layout_helper_is_array(jint lh) {
301 return (jint)lh < (jint)_lh_neutral_value;
302 }
303 static bool layout_helper_is_typeArray(jint lh) {
304 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift);
305 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift);
306 }
307 static bool layout_helper_is_objArray(jint lh) {
308 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift);
309 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift);
310 }
311 static int layout_helper_header_size(jint lh) {
312 assert(lh < (jint)_lh_neutral_value, "must be array");
313 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask;
314 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity");
315 return hsize;
316 }
317 static BasicType layout_helper_element_type(jint lh) {
318 assert(lh < (jint)_lh_neutral_value, "must be array");
319 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask;
320 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity");
321 return (BasicType) btvalue;
322 }
323 static int layout_helper_log2_element_size(jint lh) {
324 assert(lh < (jint)_lh_neutral_value, "must be array");
325 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask;
326 assert(l2esz <= LogBitsPerLong,
327 err_msg("sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh));
328 return l2esz;
329 }
330 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) {
331 return (tag << _lh_array_tag_shift)
332 | (hsize << _lh_header_size_shift)
333 | ((int)etype << _lh_element_type_shift)
334 | (log2_esize << _lh_log2_element_size_shift);
335 }
336 static jint instance_layout_helper(jint size, bool slow_path_flag) {
337 return (size << LogHeapWordSize)
338 | (slow_path_flag ? _lh_instance_slow_path_bit : 0);
339 }
340 static int layout_helper_to_size_helper(jint lh) {
341 assert(lh > (jint)_lh_neutral_value, "must be instance");
342 // Note that the following expression discards _lh_instance_slow_path_bit.
343 return lh >> LogHeapWordSize;
344 }
345 // Out-of-line version computes everything based on the etype:
346 static jint array_layout_helper(BasicType etype);
347
348 // What is the maximum number of primary superclasses any klass can have?
349 #ifdef PRODUCT
350 static juint primary_super_limit() { return _primary_super_limit; }
351 #else
352 static juint primary_super_limit() {
353 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob");
354 return FastSuperclassLimit;
355 }
356 #endif
357
358 // vtables
359 virtual klassVtable* vtable() const { return NULL; }
360 virtual int vtable_length() const { return 0; }
361
362 // subclass check
363 bool is_subclass_of(const Klass* k) const;
364 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it
365 bool is_subtype_of(Klass* k) const {
366 juint off = k->super_check_offset();
367 Klass* sup = *(Klass**)( (address)this + off );
368 const juint secondary_offset = in_bytes(secondary_super_cache_offset());
369 if (sup == k) {
370 return true;
371 } else if (off != secondary_offset) {
372 return false;
373 } else {
374 return search_secondary_supers(k);
375 }
376 }
377 bool search_secondary_supers(Klass* k) const;
378
379 // Find LCA in class hierarchy
380 Klass *LCA( Klass *k );
381
382 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
383 // if not, throw either an Error or an Exception.
384 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
385
386 // array copying
387 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
388
389 // tells if the class should be initialized
390 virtual bool should_be_initialized() const { return false; }
391 // initializes the klass
392 virtual void initialize(TRAPS);
393 // lookup operation for MethodLookupCache
394 friend class MethodLookupCache;
395 virtual Method* uncached_lookup_method(Symbol* name, Symbol* signature, MethodLookupMode mode) const;
396 public:
397 Method* lookup_method(Symbol* name, Symbol* signature) const {
398 return uncached_lookup_method(name, signature, normal);
399 }
400
401 // array class with specific rank
402 Klass* array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); }
403
404 // array class with this klass as element type
405 Klass* array_klass(TRAPS) { return array_klass_impl(false, THREAD); }
406
407 // These will return NULL instead of allocating on the heap:
408 // NB: these can block for a mutex, like other functions with TRAPS arg.
409 Klass* array_klass_or_null(int rank);
410 Klass* array_klass_or_null();
411
412 virtual oop protection_domain() const = 0;
413
414 oop class_loader() const;
415
416 virtual oop klass_holder() const { return class_loader(); }
417
418 protected:
419 virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS);
420 virtual Klass* array_klass_impl(bool or_null, TRAPS);
421
422 public:
423 // CDS support - remove and restore oops from metadata. Oops are not shared.
424 virtual void remove_unshareable_info();
425 virtual void restore_unshareable_info(TRAPS);
426
427 protected:
428 // computes the subtype relationship
429 virtual bool compute_is_subtype_of(Klass* k);
430 public:
431 // subclass accessor (here for convenience; undefined for non-klass objects)
432 virtual bool is_leaf_class() const { fatal("not a class"); return false; }
433 public:
434 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP
435 // These functions describe behavior for the oop not the KLASS.
436
437 // actual oop size of obj in memory
438 virtual int oop_size(oop obj) const = 0;
439
440 // Size of klass in word size.
441 virtual int size() const = 0;
442 #if INCLUDE_SERVICES
443 virtual void collect_statistics(KlassSizeStats *sz) const;
444 #endif
445
446 // Returns the Java name for a class (Resource allocated)
447 // For arrays, this returns the name of the element with a leading '['.
448 // For classes, this returns the name with the package separators
449 // turned into '.'s.
450 const char* external_name() const;
451 // Returns the name for a class (Resource allocated) as the class
452 // would appear in a signature.
453 // For arrays, this returns the name of the element with a leading '['.
454 // For classes, this returns the name with a leading 'L' and a trailing ';'
455 // and the package separators as '/'.
456 virtual const char* signature_name() const;
457
458 // garbage collection support
459 virtual void oop_follow_contents(oop obj) = 0;
460 virtual int oop_adjust_pointers(oop obj) = 0;
461
462 // Parallel Scavenge and Parallel Old
463 PARALLEL_GC_DECLS_PV
464
465 // type testing operations
466 protected:
467 virtual bool oop_is_instance_slow() const { return false; }
468 virtual bool oop_is_array_slow() const { return false; }
469 virtual bool oop_is_objArray_slow() const { return false; }
470 virtual bool oop_is_typeArray_slow() const { return false; }
471 public:
472 virtual bool oop_is_instanceClassLoader() const { return false; }
473 virtual bool oop_is_instanceMirror() const { return false; }
474 virtual bool oop_is_instanceRef() const { return false; }
475
476 // Fast non-virtual versions
477 #ifndef ASSERT
478 #define assert_same_query(xval, xcheck) xval
479 #else
480 private:
481 static bool assert_same_query(bool xval, bool xslow) {
482 assert(xval == xslow, "slow and fast queries agree");
483 return xval;
484 }
485 public:
486 #endif
487 inline bool oop_is_instance() const { return assert_same_query(
488 layout_helper_is_instance(layout_helper()),
489 oop_is_instance_slow()); }
490 inline bool oop_is_array() const { return assert_same_query(
491 layout_helper_is_array(layout_helper()),
492 oop_is_array_slow()); }
493 inline bool oop_is_objArray() const { return assert_same_query(
494 layout_helper_is_objArray(layout_helper()),
495 oop_is_objArray_slow()); }
496 inline bool oop_is_typeArray() const { return assert_same_query(
497 layout_helper_is_typeArray(layout_helper()),
498 oop_is_typeArray_slow()); }
499 #undef assert_same_query
500
501 // Access flags
502 AccessFlags access_flags() const { return _access_flags; }
503 void set_access_flags(AccessFlags flags) { _access_flags = flags; }
504
505 bool is_public() const { return _access_flags.is_public(); }
506 bool is_final() const { return _access_flags.is_final(); }
507 bool is_interface() const { return _access_flags.is_interface(); }
508 bool is_abstract() const { return _access_flags.is_abstract(); }
509 bool is_super() const { return _access_flags.is_super(); }
510 bool is_synthetic() const { return _access_flags.is_synthetic(); }
511 void set_is_synthetic() { _access_flags.set_is_synthetic(); }
512 bool has_finalizer() const { return _access_flags.has_finalizer(); }
513 bool has_final_method() const { return _access_flags.has_final_method(); }
514 void set_has_finalizer() { _access_flags.set_has_finalizer(); }
515 void set_has_final_method() { _access_flags.set_has_final_method(); }
516 bool is_cloneable() const { return _access_flags.is_cloneable(); }
517 void set_is_cloneable() { _access_flags.set_is_cloneable(); }
518 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); }
519 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); }
520 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); }
521 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); }
522
523 // Biased locking support
524 // Note: the prototype header is always set up to be at least the
525 // prototype markOop. If biased locking is enabled it may further be
526 // biasable and have an epoch.
527 markOop prototype_header() const { return _prototype_header; }
528 // NOTE: once instances of this klass are floating around in the
529 // system, this header must only be updated at a safepoint.
530 // NOTE 2: currently we only ever set the prototype header to the
531 // biasable prototype for instanceKlasses. There is no technical
532 // reason why it could not be done for arrayKlasses aside from
533 // wanting to reduce the initial scope of this optimization. There
534 // are potential problems in setting the bias pattern for
535 // JVM-internal oops.
536 inline void set_prototype_header(markOop header);
537 static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); }
538
539 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; }
540 // Atomically increments biased_lock_revocation_count and returns updated value
541 int atomic_incr_biased_lock_revocation_count();
542 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; }
543 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; }
544 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; }
545
546 TRACE_DEFINE_KLASS_METHODS;
547
548 // garbage collection support
549 virtual void oops_do(OopClosure* cl);
550
551 // Iff the class loader (or mirror for anonymous classes) is alive the
552 // Klass is considered alive.
553 // The is_alive closure passed in depends on the Garbage Collector used.
554 bool is_loader_alive(BoolObjectClosure* is_alive);
555
556 static void clean_weak_klass_links(BoolObjectClosure* is_alive);
557
558 // iterators
559 virtual int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) = 0;
560 virtual int oop_oop_iterate_v(oop obj, ExtendedOopClosure* blk) {
561 return oop_oop_iterate(obj, blk);
562 }
563
564 #if INCLUDE_ALL_GCS
565 // In case we don't have a specialized backward scanner use forward
566 // iteration.
567 virtual int oop_oop_iterate_backwards_v(oop obj, ExtendedOopClosure* blk) {
568 return oop_oop_iterate_v(obj, blk);
569 }
570 #endif // INCLUDE_ALL_GCS
571
572 // Iterates "blk" over all the oops in "obj" (of type "this") within "mr".
573 // (I don't see why the _m should be required, but without it the Solaris
574 // C++ gives warning messages about overridings of the "oop_oop_iterate"
575 // defined above "hiding" this virtual function. (DLD, 6/20/00)) */
576 virtual int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) = 0;
577 virtual int oop_oop_iterate_v_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) {
578 return oop_oop_iterate_m(obj, blk, mr);
579 }
580
581 // Versions of the above iterators specialized to particular subtypes
582 // of OopClosure, to avoid closure virtual calls.
583 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
584 virtual int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk) { \
585 /* Default implementation reverts to general version. */ \
586 return oop_oop_iterate(obj, blk); \
587 } \
588 \
589 /* Iterates "blk" over all the oops in "obj" (of type "this") within "mr". \
590 (I don't see why the _m should be required, but without it the Solaris \
591 C++ gives warning messages about overridings of the "oop_oop_iterate" \
592 defined above "hiding" this virtual function. (DLD, 6/20/00)) */ \
593 virtual int oop_oop_iterate##nv_suffix##_m(oop obj, \
594 OopClosureType* blk, \
595 MemRegion mr) { \
596 return oop_oop_iterate_m(obj, blk, mr); \
597 }
598
599 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL)
600 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL)
601
602 #if INCLUDE_ALL_GCS
603 #define Klass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
604 virtual int oop_oop_iterate_backwards##nv_suffix(oop obj, \
605 OopClosureType* blk) { \
606 /* Default implementation reverts to general version. */ \
607 return oop_oop_iterate_backwards_v(obj, blk); \
608 }
609
610 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL)
611 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL)
612 #endif // INCLUDE_ALL_GCS
613
614 virtual void array_klasses_do(void f(Klass* k)) {}
615
616 // Return self, except for abstract classes with exactly 1
617 // implementor. Then return the 1 concrete implementation.
618 Klass *up_cast_abstract();
619
620 // klass name
621 Symbol* name() const { return _name; }
622 void set_name(Symbol* n);
623
624 public:
625 // jvm support
626 virtual jint compute_modifier_flags(TRAPS) const;
627
628 // JVMTI support
629 virtual jint jvmti_class_status() const;
630
631 // Printing
632 virtual void print_on(outputStream* st) const;
633
634 virtual void oop_print_value_on(oop obj, outputStream* st);
635 virtual void oop_print_on (oop obj, outputStream* st);
636
637 virtual const char* internal_name() const = 0;
638
639 // Verification
640 virtual void verify_on(outputStream* st);
641 void verify() { verify_on(tty); }
642
643 #ifndef PRODUCT
644 bool verify_vtable_index(int index);
645 bool verify_itable_index(int index);
646 #endif
647
648 virtual void oop_verify_on(oop obj, outputStream* st);
649
650 static bool is_null(narrowKlass obj);
651 static bool is_null(Klass* obj);
652
653 // klass encoding for klass pointer in objects.
654 static narrowKlass encode_klass_not_null(Klass* v);
655 static narrowKlass encode_klass(Klass* v);
656
657 static Klass* decode_klass_not_null(narrowKlass v);
658 static Klass* decode_klass(narrowKlass v);
659
660 private:
661 // barriers used by klass_oop_store
662 void klass_update_barrier_set(oop v);
663 void klass_update_barrier_set_pre(void* p, oop v);
664 };
665
666 #endif // SHARE_VM_OOPS_KLASS_HPP