1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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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 #if INCLUDE_CDS
160 // Flags of the current shared class.
161 u2 _shared_class_flags;
162 enum {
163 _has_raw_archived_mirror = 1,
164 _has_signer_and_not_archived = 1 << 2
165 };
166 #endif
167 // The _archived_mirror is set at CDS dump time pointing to the cached mirror
168 // in the open archive heap region when archiving java object is supported.
169 CDS_JAVA_HEAP_ONLY(narrowOop _archived_mirror);
170
171 friend class SharedClassUtil;
172 protected:
173
174 // Constructor
175 Klass();
176
177 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw();
178
179 public:
180 enum DefaultsLookupMode { find_defaults, skip_defaults };
181 enum OverpassLookupMode { find_overpass, skip_overpass };
182 enum StaticLookupMode { find_static, skip_static };
183 enum PrivateLookupMode { find_private, skip_private };
184
185 bool is_klass() const volatile { return true; }
186
187 // super
188 Klass* super() const { return _super; }
189 void set_super(Klass* k) { _super = k; }
190
191 // initializes _super link, _primary_supers & _secondary_supers arrays
192 void initialize_supers(Klass* k, TRAPS);
193 void initialize_supers_impl1(Klass* k);
194 void initialize_supers_impl2(Klass* k);
195
196 // klass-specific helper for initializing _secondary_supers
197 virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
198
199 // java_super is the Java-level super type as specified by Class.getSuperClass.
200 virtual Klass* java_super() const { return NULL; }
201
202 juint super_check_offset() const { return _super_check_offset; }
203 void set_super_check_offset(juint o) { _super_check_offset = o; }
204
205 Klass* secondary_super_cache() const { return _secondary_super_cache; }
206 void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; }
207
208 Array<Klass*>* secondary_supers() const { return _secondary_supers; }
209 void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; }
210
211 // Return the element of the _super chain of the given depth.
212 // If there is no such element, return either NULL or this.
213 Klass* primary_super_of_depth(juint i) const {
214 assert(i < primary_super_limit(), "oob");
215 Klass* super = _primary_supers[i];
216 assert(super == NULL || super->super_depth() == i, "correct display");
217 return super;
218 }
219
220 // Can this klass be a primary super? False for interfaces and arrays of
221 // interfaces. False also for arrays or classes with long super chains.
222 bool can_be_primary_super() const {
223 const juint secondary_offset = in_bytes(secondary_super_cache_offset());
224 return super_check_offset() != secondary_offset;
225 }
226 virtual bool can_be_primary_super_slow() const;
227
228 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit].
229 juint super_depth() const {
230 if (!can_be_primary_super()) {
231 return primary_super_limit();
232 } else {
233 juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*);
234 assert(d < primary_super_limit(), "oob");
235 assert(_primary_supers[d] == this, "proper init");
236 return d;
237 }
238 }
239
240 // java mirror
241 oop java_mirror() const;
242 void set_java_mirror(Handle m);
243
244 oop archived_java_mirror_raw() NOT_CDS_JAVA_HEAP_RETURN_(NULL); // no GC barrier
245 oop archived_java_mirror() NOT_CDS_JAVA_HEAP_RETURN_(NULL); // accessor with GC barrier
246 void set_archived_java_mirror_raw(oop m) NOT_CDS_JAVA_HEAP_RETURN; // no GC barrier
247
248 // Temporary mirror switch used by RedefineClasses
249 // Both mirrors are on the ClassLoaderData::_handles list already so no
250 // barriers are needed.
251 void set_java_mirror_handle(OopHandle mirror) { _java_mirror = mirror; }
252 OopHandle java_mirror_handle() const {
253 return _java_mirror;
254 }
255
256 // modifier flags
257 jint modifier_flags() const { return _modifier_flags; }
258 void set_modifier_flags(jint flags) { _modifier_flags = flags; }
259
260 // size helper
261 int layout_helper() const { return _layout_helper; }
262 void set_layout_helper(int lh) { _layout_helper = lh; }
263
264 // Note: for instances layout_helper() may include padding.
265 // Use InstanceKlass::contains_field_offset to classify field offsets.
266
267 // sub/superklass links
268 Klass* subklass() const { return _subklass; }
269 Klass* next_sibling() const { return _next_sibling; }
270 InstanceKlass* superklass() const;
271 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list
272
273 void set_next_link(Klass* k) { _next_link = k; }
274 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader.
275
276 // class loader data
277 ClassLoaderData* class_loader_data() const { return _class_loader_data; }
278 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; }
279
280 int shared_classpath_index() const {
281 return _shared_class_path_index;
282 };
283
284 void set_shared_classpath_index(int index) {
285 _shared_class_path_index = index;
286 };
287
288 void set_has_raw_archived_mirror() {
289 CDS_ONLY(_shared_class_flags |= _has_raw_archived_mirror;)
290 }
291 void clear_has_raw_archived_mirror() {
292 CDS_ONLY(_shared_class_flags &= ~_has_raw_archived_mirror;)
293 }
294 bool has_raw_archived_mirror() const {
295 CDS_ONLY(return (_shared_class_flags & _has_raw_archived_mirror) != 0;)
296 NOT_CDS(return false;)
297 }
298 #if INCLUDE_CDS
299 void set_has_signer_and_not_archived() {
300 _shared_class_flags |= _has_signer_and_not_archived;
301 }
302 bool has_signer_and_not_archived() const {
303 assert(DumpSharedSpaces, "dump time only");
304 return (_shared_class_flags & _has_signer_and_not_archived) != 0;
305 }
306 #endif // INCLUDE_CDS
307
308 // Obtain the module or package for this class
309 virtual ModuleEntry* module() const = 0;
310 virtual PackageEntry* package() const = 0;
311
312 protected: // internal accessors
313 void set_subklass(Klass* s);
314 void set_next_sibling(Klass* s);
315
316 public:
317
318 // Compiler support
319 static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); }
320 static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); }
321 static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); }
322 static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); }
323 static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); }
324 static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); }
325 static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); }
326 static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); }
327 static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); }
328
329 // Unpacking layout_helper:
330 enum {
331 _lh_neutral_value = 0, // neutral non-array non-instance value
332 _lh_instance_slow_path_bit = 0x01,
333 _lh_log2_element_size_shift = BitsPerByte*0,
334 _lh_log2_element_size_mask = BitsPerLong-1,
335 _lh_element_type_shift = BitsPerByte*1,
336 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask
337 _lh_header_size_shift = BitsPerByte*2,
338 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask
339 _lh_array_tag_bits = 2,
340 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits,
341 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30
342 };
343
344 static const unsigned int _lh_array_tag_type_value = 0Xffffffff; // ~0x00, // 0xC0000000 >> 30
345
346 static int layout_helper_size_in_bytes(jint lh) {
347 assert(lh > (jint)_lh_neutral_value, "must be instance");
348 return (int) lh & ~_lh_instance_slow_path_bit;
349 }
350 static bool layout_helper_needs_slow_path(jint lh) {
351 assert(lh > (jint)_lh_neutral_value, "must be instance");
352 return (lh & _lh_instance_slow_path_bit) != 0;
353 }
354 static bool layout_helper_is_instance(jint lh) {
355 return (jint)lh > (jint)_lh_neutral_value;
356 }
357 static bool layout_helper_is_array(jint lh) {
358 return (jint)lh < (jint)_lh_neutral_value;
359 }
360 static bool layout_helper_is_typeArray(jint lh) {
361 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift);
362 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift);
363 }
364 static bool layout_helper_is_objArray(jint lh) {
365 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift);
366 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift);
367 }
368 static int layout_helper_header_size(jint lh) {
369 assert(lh < (jint)_lh_neutral_value, "must be array");
370 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask;
371 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity");
372 return hsize;
373 }
374 static BasicType layout_helper_element_type(jint lh) {
375 assert(lh < (jint)_lh_neutral_value, "must be array");
376 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask;
377 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity");
378 return (BasicType) btvalue;
379 }
380
381 // Want a pattern to quickly diff against layout header in register
382 // find something less clever!
383 static int layout_helper_boolean_diffbit() {
384 jint zlh = array_layout_helper(T_BOOLEAN);
385 jint blh = array_layout_helper(T_BYTE);
386 assert(zlh != blh, "array layout helpers must differ");
387 int diffbit = 1;
388 while ((diffbit & (zlh ^ blh)) == 0 && (diffbit & zlh) == 0) {
389 diffbit <<= 1;
390 assert(diffbit != 0, "make sure T_BOOLEAN has a different bit than T_BYTE");
391 }
392 return diffbit;
393 }
394
395 static int layout_helper_log2_element_size(jint lh) {
396 assert(lh < (jint)_lh_neutral_value, "must be array");
397 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask;
398 assert(l2esz <= LogBytesPerLong,
399 "sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh);
400 return l2esz;
401 }
402 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) {
403 return (tag << _lh_array_tag_shift)
404 | (hsize << _lh_header_size_shift)
405 | ((int)etype << _lh_element_type_shift)
406 | (log2_esize << _lh_log2_element_size_shift);
407 }
408 static jint instance_layout_helper(jint size, bool slow_path_flag) {
409 return (size << LogBytesPerWord)
410 | (slow_path_flag ? _lh_instance_slow_path_bit : 0);
411 }
412 static int layout_helper_to_size_helper(jint lh) {
413 assert(lh > (jint)_lh_neutral_value, "must be instance");
414 // Note that the following expression discards _lh_instance_slow_path_bit.
415 return lh >> LogBytesPerWord;
416 }
417 // Out-of-line version computes everything based on the etype:
418 static jint array_layout_helper(BasicType etype);
419
420 // What is the maximum number of primary superclasses any klass can have?
421 #ifdef PRODUCT
422 static juint primary_super_limit() { return _primary_super_limit; }
423 #else
424 static juint primary_super_limit() {
425 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob");
426 return FastSuperclassLimit;
427 }
428 #endif
429
430 // vtables
431 klassVtable vtable() const;
432 int vtable_length() const { return _vtable_len; }
433
434 // subclass check
435 bool is_subclass_of(const Klass* k) const;
436 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it
437 bool is_subtype_of(Klass* k) const {
438 juint off = k->super_check_offset();
439 Klass* sup = *(Klass**)( (address)this + off );
440 const juint secondary_offset = in_bytes(secondary_super_cache_offset());
441 if (sup == k) {
442 return true;
443 } else if (off != secondary_offset) {
444 return false;
445 } else {
446 return search_secondary_supers(k);
447 }
448 }
449
450 bool search_secondary_supers(Klass* k) const;
451
452 // Find LCA in class hierarchy
453 Klass *LCA( Klass *k );
454
455 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
456 // if not, throw either an Error or an Exception.
457 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
458
459 // array copying
460 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
461
462 // tells if the class should be initialized
463 virtual bool should_be_initialized() const { return false; }
464 // initializes the klass
465 virtual void initialize(TRAPS);
466 // lookup operation for MethodLookupCache
467 friend class MethodLookupCache;
468 virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const;
469 virtual Method* uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const;
470 public:
471 Method* lookup_method(const Symbol* name, const Symbol* signature) const {
472 return uncached_lookup_method(name, signature, find_overpass);
473 }
474
475 // array class with specific rank
476 Klass* array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); }
477
478 // array class with this klass as element type
479 Klass* array_klass(TRAPS) { return array_klass_impl(false, THREAD); }
480
481 // These will return NULL instead of allocating on the heap:
482 // NB: these can block for a mutex, like other functions with TRAPS arg.
483 Klass* array_klass_or_null(int rank);
484 Klass* array_klass_or_null();
485
486 virtual oop protection_domain() const = 0;
487
488 oop class_loader() const;
489
490 virtual oop klass_holder() const { return class_loader(); }
491
492 protected:
493 virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS);
494 virtual Klass* array_klass_impl(bool or_null, TRAPS);
495
496 void set_vtable_length(int len) { _vtable_len= len; }
497
498 vtableEntry* start_of_vtable() const;
499 public:
500 Method* method_at_vtable(int index);
501
502 static ByteSize vtable_start_offset();
503 static ByteSize vtable_length_offset() {
504 return byte_offset_of(Klass, _vtable_len);
505 }
506
507 // CDS support - remove and restore oops from metadata. Oops are not shared.
508 virtual void remove_unshareable_info();
509 virtual void remove_java_mirror();
510 virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
511
512 protected:
513 // computes the subtype relationship
514 virtual bool compute_is_subtype_of(Klass* k);
515 public:
516 // subclass accessor (here for convenience; undefined for non-klass objects)
517 virtual bool is_leaf_class() const { fatal("not a class"); return false; }
518 public:
519 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP
520 // These functions describe behavior for the oop not the KLASS.
521
522 // actual oop size of obj in memory
523 virtual int oop_size(oop obj) const = 0;
524
525 // Size of klass in word size.
526 virtual int size() const = 0;
527 #if INCLUDE_SERVICES
528 virtual void collect_statistics(KlassSizeStats *sz) const;
529 #endif
530
531 // Returns the Java name for a class (Resource allocated)
532 // For arrays, this returns the name of the element with a leading '['.
533 // For classes, this returns the name with the package separators
534 // turned into '.'s.
535 const char* external_name() const;
536 // Returns the name for a class (Resource allocated) as the class
537 // would appear in a signature.
538 // For arrays, this returns the name of the element with a leading '['.
539 // For classes, this returns the name with a leading 'L' and a trailing ';'
540 // and the package separators as '/'.
541 virtual const char* signature_name() const;
542
543 const char* class_loader_and_module_name() const;
544
545 // Returns "interface", "abstract class" or "class".
546 const char* external_kind() const;
547
548 // type testing operations
549 #ifdef ASSERT
550 protected:
551 virtual bool is_instance_klass_slow() const { return false; }
552 virtual bool is_array_klass_slow() const { return false; }
553 virtual bool is_objArray_klass_slow() const { return false; }
554 virtual bool is_typeArray_klass_slow() const { return false; }
555 #endif // ASSERT
556 public:
557
558 // Fast non-virtual versions
559 #ifndef ASSERT
560 #define assert_same_query(xval, xcheck) xval
561 #else
562 private:
563 static bool assert_same_query(bool xval, bool xslow) {
564 assert(xval == xslow, "slow and fast queries agree");
565 return xval;
566 }
567 public:
568 #endif
569 inline bool is_instance_klass() const { return assert_same_query(
570 layout_helper_is_instance(layout_helper()),
571 is_instance_klass_slow()); }
572 inline bool is_array_klass() const { return assert_same_query(
573 layout_helper_is_array(layout_helper()),
574 is_array_klass_slow()); }
575 inline bool is_objArray_klass() const { return assert_same_query(
576 layout_helper_is_objArray(layout_helper()),
577 is_objArray_klass_slow()); }
578 inline bool is_typeArray_klass() const { return assert_same_query(
579 layout_helper_is_typeArray(layout_helper()),
580 is_typeArray_klass_slow()); }
581 #undef assert_same_query
582
583 // Access flags
584 AccessFlags access_flags() const { return _access_flags; }
585 void set_access_flags(AccessFlags flags) { _access_flags = flags; }
586
587 bool is_public() const { return _access_flags.is_public(); }
588 bool is_final() const { return _access_flags.is_final(); }
589 bool is_interface() const { return _access_flags.is_interface(); }
590 bool is_abstract() const { return _access_flags.is_abstract(); }
591 bool is_super() const { return _access_flags.is_super(); }
592 bool is_synthetic() const { return _access_flags.is_synthetic(); }
593 void set_is_synthetic() { _access_flags.set_is_synthetic(); }
594 bool has_finalizer() const { return _access_flags.has_finalizer(); }
595 bool has_final_method() const { return _access_flags.has_final_method(); }
596 void set_has_finalizer() { _access_flags.set_has_finalizer(); }
597 void set_has_final_method() { _access_flags.set_has_final_method(); }
598 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); }
599 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); }
600 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); }
601 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); }
602 bool is_shared() const { return access_flags().is_shared_class(); } // shadows MetaspaceObj::is_shared)()
603 void set_is_shared() { _access_flags.set_is_shared_class(); }
604
605 bool is_cloneable() const;
606 void set_is_cloneable();
607
608 // Biased locking support
609 // Note: the prototype header is always set up to be at least the
610 // prototype markOop. If biased locking is enabled it may further be
611 // biasable and have an epoch.
612 markOop prototype_header() const { return _prototype_header; }
613 // NOTE: once instances of this klass are floating around in the
614 // system, this header must only be updated at a safepoint.
615 // NOTE 2: currently we only ever set the prototype header to the
616 // biasable prototype for instanceKlasses. There is no technical
617 // reason why it could not be done for arrayKlasses aside from
618 // wanting to reduce the initial scope of this optimization. There
619 // are potential problems in setting the bias pattern for
620 // JVM-internal oops.
621 inline void set_prototype_header(markOop header);
622 static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); }
623
624 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; }
625 // Atomically increments biased_lock_revocation_count and returns updated value
626 int atomic_incr_biased_lock_revocation_count();
627 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; }
628 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; }
629 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; }
630
631 TRACE_DEFINE_TRACE_ID_METHODS;
632
633 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
634 virtual MetaspaceObj::Type type() const { return ClassType; }
635
636 // Iff the class loader (or mirror for anonymous classes) is alive the
637 // Klass is considered alive.
638 // The is_alive closure passed in depends on the Garbage Collector used.
639 bool is_loader_alive(BoolObjectClosure* is_alive);
640
641 static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true);
642 static void clean_subklass_tree(BoolObjectClosure* is_alive) {
643 clean_weak_klass_links(is_alive, false /* clean_alive_klasses */);
644 }
645
646 // GC specific object visitors
647 //
648 #if INCLUDE_ALL_GCS
649 // Parallel Scavenge
650 virtual void oop_ps_push_contents( oop obj, PSPromotionManager* pm) = 0;
651 // Parallel Compact
652 virtual void oop_pc_follow_contents(oop obj, ParCompactionManager* cm) = 0;
653 virtual void oop_pc_update_pointers(oop obj, ParCompactionManager* cm) = 0;
654 #endif
655
656 // Iterators specialized to particular subtypes
657 // of ExtendedOopClosure, to avoid closure virtual calls.
658 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
659 virtual void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) = 0; \
660 /* Iterates "closure" over all the oops in "obj" (of type "this") within "mr". */ \
661 virtual void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) = 0;
662
663 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL)
664 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL)
665
666 #if INCLUDE_ALL_GCS
667 #define Klass_OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \
668 virtual void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) = 0;
669
670 ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
671 ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
672 #endif // INCLUDE_ALL_GCS
673
674 virtual void array_klasses_do(void f(Klass* k)) {}
675
676 // Return self, except for abstract classes with exactly 1
677 // implementor. Then return the 1 concrete implementation.
678 Klass *up_cast_abstract();
679
680 // klass name
681 Symbol* name() const { return _name; }
682 void set_name(Symbol* n);
683
684 public:
685 // jvm support
686 virtual jint compute_modifier_flags(TRAPS) const;
687
688 // JVMTI support
689 virtual jint jvmti_class_status() const;
690
691 // Printing
692 virtual void print_on(outputStream* st) const;
693
694 virtual void oop_print_value_on(oop obj, outputStream* st);
695 virtual void oop_print_on (oop obj, outputStream* st);
696
697 virtual const char* internal_name() const = 0;
698
699 // Verification
700 virtual void verify_on(outputStream* st);
701 void verify() { verify_on(tty); }
702
703 #ifndef PRODUCT
704 bool verify_vtable_index(int index);
705 bool verify_itable_index(int index);
706 #endif
707
708 virtual void oop_verify_on(oop obj, outputStream* st);
709
710 static bool is_null(narrowKlass obj);
711 static bool is_null(Klass* obj);
712
713 // klass encoding for klass pointer in objects.
714 static narrowKlass encode_klass_not_null(Klass* v);
715 static narrowKlass encode_klass(Klass* v);
716
717 static Klass* decode_klass_not_null(narrowKlass v);
718 static Klass* decode_klass(narrowKlass v);
719 };
720
721 // Helper to convert the oop iterate macro suffixes into bool values that can be used by template functions.
722 #define nvs_nv_to_bool true
723 #define nvs_v_to_bool false
724 #define nvs_to_bool(nv_suffix) nvs##nv_suffix##_to_bool
725
726 // Oop iteration macros for declarations.
727 // Used to generate declarations in the *Klass header files.
728
729 #define OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
730 void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure); \
731 void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr);
732
733 #if INCLUDE_ALL_GCS
734 #define OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix) \
735 void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure);
736 #endif // INCLUDE_ALL_GCS
737
738
739 // Oop iteration macros for definitions.
740 // Used to generate definitions in the *Klass.inline.hpp files.
741
742 #define OOP_OOP_ITERATE_DEFN(KlassType, OopClosureType, nv_suffix) \
743 void KlassType::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
744 oop_oop_iterate<nvs_to_bool(nv_suffix)>(obj, closure); \
745 }
746
747 #if INCLUDE_ALL_GCS
748 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix) \
749 void KlassType::oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) { \
750 oop_oop_iterate_reverse<nvs_to_bool(nv_suffix)>(obj, closure); \
751 }
752 #else
753 #define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix)
754 #endif
755
756 #define OOP_OOP_ITERATE_DEFN_BOUNDED(KlassType, OopClosureType, nv_suffix) \
757 void KlassType::oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) { \
758 oop_oop_iterate_bounded<nvs_to_bool(nv_suffix)>(obj, closure, mr); \
759 }
760
761 #endif // SHARE_VM_OOPS_KLASS_HPP