1 /*
2 * Copyright (c) 1997, 2021, 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.
22 *
23 */
24
25 #ifndef SHARE_OOPS_KLASS_HPP
26 #define SHARE_OOPS_KLASS_HPP
27
28 #include "memory/iterator.hpp"
29 #include "memory/memRegion.hpp"
30 #include "oops/markWord.hpp"
31 #include "oops/metadata.hpp"
32 #include "oops/oop.hpp"
33 #include "oops/oopHandle.hpp"
34 #include "utilities/accessFlags.hpp"
35 #include "utilities/macros.hpp"
36 #if INCLUDE_JFR
37 #include "jfr/support/jfrTraceIdExtension.hpp"
38 #endif
39
40 // Klass IDs for all subclasses of Klass
41 enum KlassID {
42 InstanceKlassID,
43 InstanceRefKlassID,
44 InstanceMirrorKlassID,
45 InstanceClassLoaderKlassID,
46 TypeArrayKlassID,
47 ObjArrayKlassID
48 };
49
50 const uint KLASS_ID_COUNT = 6;
51
52 //
53 // A Klass provides:
54 // 1: language level class object (method dictionary etc.)
55 // 2: provide vm dispatch behavior for the object
56 // Both functions are combined into one C++ class.
57
58 // One reason for the oop/klass dichotomy in the implementation is
59 // that we don't want a C++ vtbl pointer in every object. Thus,
60 // normal oops don't have any virtual functions. Instead, they
61 // forward all "virtual" functions to their klass, which does have
62 // a vtbl and does the C++ dispatch depending on the object's
63 // actual type. (See oop.inline.hpp for some of the forwarding code.)
64 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"!
65
66 // Forward declarations.
67 template <class T> class Array;
68 template <class T> class GrowableArray;
69 class ClassLoaderData;
70 class fieldDescriptor;
71 class klassVtable;
72 class ModuleEntry;
73 class PackageEntry;
74 class ParCompactionManager;
75 class PSPromotionManager;
76 class vtableEntry;
77
78 class Klass : public Metadata {
79 friend class VMStructs;
80 friend class JVMCIVMStructs;
81 protected:
82 // If you add a new field that points to any metaspace object, you
83 // must add this field to Klass::metaspace_pointers_do().
84
85 // note: put frequently-used fields together at start of klass structure
86 // for better cache behavior (may not make much of a difference but sure won't hurt)
87 enum { _primary_super_limit = 8 };
88
89 // The "layout helper" is a combined descriptor of object layout.
90 // For klasses which are neither instance nor array, the value is zero.
91 //
92 // For instances, layout helper is a positive number, the instance size.
93 // This size is already passed through align_object_size and scaled to bytes.
94 // The low order bit is set if instances of this class cannot be
95 // allocated using the fastpath.
96 //
97 // For arrays, layout helper is a negative number, containing four
98 // distinct bytes, as follows:
99 // MSB:[tag, hsz, ebt, log2(esz)]:LSB
100 // where:
101 // tag is 0x80 if the elements are oops, 0xC0 if non-oops
102 // hsz is array header size in bytes (i.e., offset of first element)
103 // ebt is the BasicType of the elements
104 // esz is the element size in bytes
105 // This packed word is arranged so as to be quickly unpacked by the
106 // various fast paths that use the various subfields.
107 //
108 // The esz bits can be used directly by a SLL instruction, without masking.
109 //
110 // Note that the array-kind tag looks like 0x00 for instance klasses,
111 // since their length in bytes is always less than 24Mb.
112 //
113 // Final note: This comes first, immediately after C++ vtable,
114 // because it is frequently queried.
115 jint _layout_helper;
116
117 // Klass identifier used to implement devirtualized oop closure dispatching.
118 const KlassID _id;
119
120 // vtable length
121 int _vtable_len;
122
123 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers
124 // and _primary_supers all help make fast subtype checks. See big discussion
125 // in doc/server_compiler/checktype.txt
126 //
127 // Where to look to observe a supertype (it is &_secondary_super_cache for
128 // secondary supers, else is &_primary_supers[depth()].
129 juint _super_check_offset;
130
131 // Class name. Instance classes: java/lang/String, etc. Array classes: [I,
132 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes.
133 Symbol* _name;
134
135 // Cache of last observed secondary supertype
136 Klass* _secondary_super_cache;
137 // Array of all secondary supertypes
138 Array<Klass*>* _secondary_supers;
139 // Ordered list of all primary supertypes
140 Klass* _primary_supers[_primary_super_limit];
141 // java/lang/Class instance mirroring this class
142 OopHandle _java_mirror;
143 // Superclass
144 Klass* _super;
145 // First subclass (NULL if none); _subklass->next_sibling() is next one
146 Klass* volatile _subklass;
147 // Sibling link (or NULL); links all subklasses of a klass
148 Klass* volatile _next_sibling;
149
150 // All klasses loaded by a class loader are chained through these links
151 Klass* _next_link;
152
153 // The VM's representation of the ClassLoader used to load this class.
154 // Provide access the corresponding instance java.lang.ClassLoader.
155 ClassLoaderData* _class_loader_data;
156
157 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers.
158 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here.
159
160 JFR_ONLY(DEFINE_TRACE_ID_FIELD;)
161
162 markWord _prototype_header; // Used to initialize objects' header
163
164 private:
165 // This is an index into FileMapHeader::_shared_path_table[], to
166 // associate this class with the JAR file where it's loaded from during
167 // dump time. If a class is not loaded from the shared archive, this field is
168 // -1.
169 jshort _shared_class_path_index;
170
171 #if INCLUDE_CDS
172 // Flags of the current shared class.
173 u2 _shared_class_flags;
174 enum {
175 _archived_lambda_proxy_is_available = 2,
176 _has_value_based_class_annotation = 4,
177 _verified_at_dump_time = 8
178 };
179 #endif
180
181 CDS_JAVA_HEAP_ONLY(int _archived_mirror_index;)
182
183 protected:
184
185 // Constructor
186 Klass(KlassID id);
187 Klass() : _id(KlassID(-1)) { assert(DumpSharedSpaces || UseSharedSpaces, "only for cds"); }
188
189 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw();
190
191 public:
192 int id() { return _id; }
193
194 enum class DefaultsLookupMode { find, skip };
195 enum class OverpassLookupMode { find, skip };
196 enum class StaticLookupMode { find, skip };
197 enum class PrivateLookupMode { find, skip };
198
199 virtual bool is_klass() const { return true; }
200
201 // super() cannot be InstanceKlass* -- Java arrays are covariant, and _super is used
202 // to implement that. NB: the _super of "[Ljava/lang/Integer;" is "[Ljava/lang/Number;"
203 // If this is not what your code expects, you're probably looking for Klass::java_super().
204 Klass* super() const { return _super; }
205 void set_super(Klass* k) { _super = k; }
206
207 // initializes _super link, _primary_supers & _secondary_supers arrays
208 void initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS);
209
210 // klass-specific helper for initializing _secondary_supers
211 virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
212 Array<InstanceKlass*>* transitive_interfaces);
213
214 // java_super is the Java-level super type as specified by Class.getSuperClass.
215 virtual InstanceKlass* java_super() const { return NULL; }
216
217 juint super_check_offset() const { return _super_check_offset; }
218 void set_super_check_offset(juint o) { _super_check_offset = o; }
219
220 Klass* secondary_super_cache() const { return _secondary_super_cache; }
221 void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; }
222
223 Array<Klass*>* secondary_supers() const { return _secondary_supers; }
224 void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; }
225
226 // Return the element of the _super chain of the given depth.
227 // If there is no such element, return either NULL or this.
228 Klass* primary_super_of_depth(juint i) const {
229 assert(i < primary_super_limit(), "oob");
230 Klass* super = _primary_supers[i];
231 assert(super == NULL || super->super_depth() == i, "correct display");
232 return super;
233 }
234
235 // Can this klass be a primary super? False for interfaces and arrays of
236 // interfaces. False also for arrays or classes with long super chains.
237 bool can_be_primary_super() const {
238 const juint secondary_offset = in_bytes(secondary_super_cache_offset());
239 return super_check_offset() != secondary_offset;
240 }
241 virtual bool can_be_primary_super_slow() const;
242
243 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit].
244 juint super_depth() const {
245 if (!can_be_primary_super()) {
246 return primary_super_limit();
247 } else {
248 juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*);
249 assert(d < primary_super_limit(), "oob");
250 assert(_primary_supers[d] == this, "proper init");
251 return d;
252 }
253 }
254
255 // java mirror
256 oop java_mirror() const;
257 oop java_mirror_no_keepalive() const;
258 void set_java_mirror(Handle m);
259
260 oop archived_java_mirror() NOT_CDS_JAVA_HEAP_RETURN_(NULL);
261 void set_archived_java_mirror(oop m) NOT_CDS_JAVA_HEAP_RETURN;
262
263 // Temporary mirror switch used by RedefineClasses
264 void replace_java_mirror(oop mirror);
265
266 // Set java mirror OopHandle to NULL for CDS
267 // This leaves the OopHandle in the CLD, but that's ok, you can't release them.
268 void clear_java_mirror_handle() { _java_mirror = OopHandle(); }
269
270 // modifier flags
271 jint modifier_flags() const { return _modifier_flags; }
272 void set_modifier_flags(jint flags) { _modifier_flags = flags; }
273
274 // size helper
275 int layout_helper() const { return _layout_helper; }
276 void set_layout_helper(int lh) { _layout_helper = lh; }
277
278 // Note: for instances layout_helper() may include padding.
279 // Use InstanceKlass::contains_field_offset to classify field offsets.
280
281 // sub/superklass links
282 Klass* subklass(bool log = false) const;
283 Klass* next_sibling(bool log = false) const;
284
285 InstanceKlass* superklass() const;
286 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list
287
288 void set_next_link(Klass* k) { _next_link = k; }
289 Klass* next_link() const { return _next_link; } // The next klass defined by the class loader.
290 Klass** next_link_addr() { return &_next_link; }
291
292 // class loader data
293 ClassLoaderData* class_loader_data() const { return _class_loader_data; }
294 void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; }
295
296 int shared_classpath_index() const {
297 return _shared_class_path_index;
298 };
299
300 void set_shared_classpath_index(int index) {
301 _shared_class_path_index = index;
302 };
303
304 bool has_archived_mirror_index() const {
305 CDS_JAVA_HEAP_ONLY(return _archived_mirror_index >= 0;)
306 NOT_CDS_JAVA_HEAP(return false);
307 }
308
309 void clear_archived_mirror_index() NOT_CDS_JAVA_HEAP_RETURN;
310
311 void set_lambda_proxy_is_available() {
312 CDS_ONLY(_shared_class_flags |= _archived_lambda_proxy_is_available;)
313 }
314 void clear_lambda_proxy_is_available() {
315 CDS_ONLY(_shared_class_flags &= ~_archived_lambda_proxy_is_available;)
316 }
317 bool lambda_proxy_is_available() const {
318 CDS_ONLY(return (_shared_class_flags & _archived_lambda_proxy_is_available) != 0;)
319 NOT_CDS(return false;)
320 }
321
322 void set_has_value_based_class_annotation() {
323 CDS_ONLY(_shared_class_flags |= _has_value_based_class_annotation;)
324 }
325 void clear_has_value_based_class_annotation() {
326 CDS_ONLY(_shared_class_flags &= ~_has_value_based_class_annotation;)
327 }
328 bool has_value_based_class_annotation() const {
329 CDS_ONLY(return (_shared_class_flags & _has_value_based_class_annotation) != 0;)
330 NOT_CDS(return false;)
331 }
332
333 void set_verified_at_dump_time() {
334 CDS_ONLY(_shared_class_flags |= _verified_at_dump_time;)
335 }
336 bool verified_at_dump_time() const {
337 CDS_ONLY(return (_shared_class_flags & _verified_at_dump_time) != 0;)
338 NOT_CDS(return false;)
339 }
340
341
342 // Obtain the module or package for this class
343 virtual ModuleEntry* module() const = 0;
344 virtual PackageEntry* package() const = 0;
345
346 protected: // internal accessors
347 void set_subklass(Klass* s);
348 void set_next_sibling(Klass* s);
349
350 public:
351
352 // Compiler support
353 static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); }
354 static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); }
355 static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); }
356 static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); }
357 static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); }
358 static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); }
359 static ByteSize class_loader_data_offset() { return in_ByteSize(offset_of(Klass, _class_loader_data)); }
360 static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); }
361 static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); }
362 static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); }
363
364 // Unpacking layout_helper:
365 static const int _lh_neutral_value = 0; // neutral non-array non-instance value
366 static const int _lh_instance_slow_path_bit = 0x01;
367 static const int _lh_log2_element_size_shift = BitsPerByte*0;
368 static const int _lh_log2_element_size_mask = BitsPerLong-1;
369 static const int _lh_element_type_shift = BitsPerByte*1;
370 static const int _lh_element_type_mask = right_n_bits(BitsPerByte); // shifted mask
371 static const int _lh_header_size_shift = BitsPerByte*2;
372 static const int _lh_header_size_mask = right_n_bits(BitsPerByte); // shifted mask
373 static const int _lh_array_tag_bits = 2;
374 static const int _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits;
375 static const int _lh_array_tag_obj_value = ~0x01; // 0x80000000 >> 30
376
377 static const unsigned int _lh_array_tag_type_value = 0Xffffffff; // ~0x00, // 0xC0000000 >> 30
378
379 static int layout_helper_size_in_bytes(jint lh) {
380 assert(lh > (jint)_lh_neutral_value, "must be instance");
381 return (int) lh & ~_lh_instance_slow_path_bit;
382 }
383 static bool layout_helper_needs_slow_path(jint lh) {
384 assert(lh > (jint)_lh_neutral_value, "must be instance");
385 return (lh & _lh_instance_slow_path_bit) != 0;
386 }
387 static bool layout_helper_is_instance(jint lh) {
388 return (jint)lh > (jint)_lh_neutral_value;
389 }
390 static bool layout_helper_is_array(jint lh) {
391 return (jint)lh < (jint)_lh_neutral_value;
392 }
393 static bool layout_helper_is_typeArray(jint lh) {
394 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift);
395 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift);
396 }
397 static bool layout_helper_is_objArray(jint lh) {
398 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift);
399 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift);
400 }
401 static int layout_helper_header_size(jint lh) {
402 assert(lh < (jint)_lh_neutral_value, "must be array");
403 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask;
404 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity");
405 return hsize;
406 }
407 static BasicType layout_helper_element_type(jint lh) {
408 assert(lh < (jint)_lh_neutral_value, "must be array");
409 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask;
410 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity");
411 return (BasicType) btvalue;
412 }
413
414 // Want a pattern to quickly diff against layout header in register
415 // find something less clever!
416 static int layout_helper_boolean_diffbit() {
417 jint zlh = array_layout_helper(T_BOOLEAN);
418 jint blh = array_layout_helper(T_BYTE);
419 assert(zlh != blh, "array layout helpers must differ");
420 int diffbit = 1;
421 while ((diffbit & (zlh ^ blh)) == 0 && (diffbit & zlh) == 0) {
422 diffbit <<= 1;
423 assert(diffbit != 0, "make sure T_BOOLEAN has a different bit than T_BYTE");
424 }
425 return diffbit;
426 }
427
428 static int layout_helper_log2_element_size(jint lh) {
429 assert(lh < (jint)_lh_neutral_value, "must be array");
430 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask;
431 assert(l2esz <= LogBytesPerLong,
432 "sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh);
433 return l2esz;
434 }
435 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) {
436 return (tag << _lh_array_tag_shift)
437 | (hsize << _lh_header_size_shift)
438 | ((int)etype << _lh_element_type_shift)
439 | (log2_esize << _lh_log2_element_size_shift);
440 }
441 static jint instance_layout_helper(jint size, bool slow_path_flag) {
442 return (size << LogBytesPerWord)
443 | (slow_path_flag ? _lh_instance_slow_path_bit : 0);
444 }
445 static int layout_helper_to_size_helper(jint lh) {
446 assert(lh > (jint)_lh_neutral_value, "must be instance");
447 // Note that the following expression discards _lh_instance_slow_path_bit.
448 return lh >> LogBytesPerWord;
449 }
450 // Out-of-line version computes everything based on the etype:
451 static jint array_layout_helper(BasicType etype);
452
453 // What is the maximum number of primary superclasses any klass can have?
454 static juint primary_super_limit() { return _primary_super_limit; }
455
456 // vtables
457 klassVtable vtable() const;
458 int vtable_length() const { return _vtable_len; }
459
460 // subclass check
461 bool is_subclass_of(const Klass* k) const;
462 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it
463 bool is_subtype_of(Klass* k) const {
464 juint off = k->super_check_offset();
465 Klass* sup = *(Klass**)( (address)this + off );
466 const juint secondary_offset = in_bytes(secondary_super_cache_offset());
467 if (sup == k) {
468 return true;
469 } else if (off != secondary_offset) {
470 return false;
471 } else {
472 return search_secondary_supers(k);
473 }
474 }
475
476 bool search_secondary_supers(Klass* k) const;
477
478 // Find LCA in class hierarchy
479 Klass *LCA( Klass *k );
480
481 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
482 // if not, throw either an Error or an Exception.
483 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
484
485 // array copying
486 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
487
488 // tells if the class should be initialized
489 virtual bool should_be_initialized() const { return false; }
490 // initializes the klass
491 virtual void initialize(TRAPS);
492 virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const;
493 virtual Method* uncached_lookup_method(const Symbol* name, const Symbol* signature,
494 OverpassLookupMode overpass_mode,
495 PrivateLookupMode = PrivateLookupMode::find) const;
496 public:
497 Method* lookup_method(const Symbol* name, const Symbol* signature) const {
498 return uncached_lookup_method(name, signature, OverpassLookupMode::find);
499 }
500
501 // array class with specific rank
502 virtual Klass* array_klass(int rank, TRAPS) = 0;
503
504 // array class with this klass as element type
505 virtual Klass* array_klass(TRAPS) = 0;
506
507 // These will return NULL instead of allocating on the heap:
508 virtual Klass* array_klass_or_null(int rank) = 0;
509 virtual Klass* array_klass_or_null() = 0;
510
511 virtual oop protection_domain() const = 0;
512
513 oop class_loader() const;
514
515 inline oop klass_holder() const;
516
517 protected:
518
519 // Error handling when length > max_length or length < 0
520 static void check_array_allocation_length(int length, int max_length, TRAPS);
521
522 void set_vtable_length(int len) { _vtable_len= len; }
523
524 vtableEntry* start_of_vtable() const;
525 void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
526 public:
527 Method* method_at_vtable(int index);
528
529 static ByteSize vtable_start_offset();
530 static ByteSize vtable_length_offset() {
531 return byte_offset_of(Klass, _vtable_len);
532 }
533
534 // CDS support - remove and restore oops from metadata. Oops are not shared.
535 virtual void remove_unshareable_info();
536 virtual void remove_java_mirror();
537
538 bool is_unshareable_info_restored() const {
539 assert(is_shared(), "use this for shared classes only");
540 if (has_archived_mirror_index()) {
541 // _java_mirror is not a valid OopHandle but rather an encoded reference in the shared heap
542 return false;
543 } else if (_java_mirror.ptr_raw() == NULL) {
544 return false;
545 } else {
546 return true;
547 }
548 }
549
550 public:
551 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP
552 // These functions describe behavior for the oop not the KLASS.
553
554 // actual oop size of obj in memory in word size.
555 virtual size_t oop_size(oop obj) const = 0;
556
557 // Size of klass in word size.
558 virtual int size() const = 0;
559
560 // Returns the Java name for a class (Resource allocated)
561 // For arrays, this returns the name of the element with a leading '['.
562 // For classes, this returns the name with the package separators
563 // turned into '.'s.
564 const char* external_name() const;
565 // Returns the name for a class (Resource allocated) as the class
566 // would appear in a signature.
567 // For arrays, this returns the name of the element with a leading '['.
568 // For classes, this returns the name with a leading 'L' and a trailing ';'
569 // and the package separators as '/'.
570 virtual const char* signature_name() const;
571
572 const char* joint_in_module_of_loader(const Klass* class2, bool include_parent_loader = false) const;
573 const char* class_in_module_of_loader(bool use_are = false, bool include_parent_loader = false) const;
574
575 // Returns "interface", "abstract class" or "class".
576 const char* external_kind() const;
577
578 // type testing operations
579 #ifdef ASSERT
580 protected:
581 virtual bool is_instance_klass_slow() const { return false; }
582 virtual bool is_array_klass_slow() const { return false; }
583 virtual bool is_objArray_klass_slow() const { return false; }
584 virtual bool is_typeArray_klass_slow() const { return false; }
585 #endif // ASSERT
586 public:
587
588 // Fast non-virtual versions
589 #ifndef ASSERT
590 #define assert_same_query(xval, xcheck) xval
591 #else
592 private:
593 static bool assert_same_query(bool xval, bool xslow) {
594 assert(xval == xslow, "slow and fast queries agree");
595 return xval;
596 }
597 public:
598 #endif
599 inline bool is_instance_klass() const { return assert_same_query(
600 layout_helper_is_instance(layout_helper()),
601 is_instance_klass_slow()); }
602 inline bool is_array_klass() const { return assert_same_query(
603 layout_helper_is_array(layout_helper()),
604 is_array_klass_slow()); }
605 inline bool is_objArray_klass() const { return assert_same_query(
606 layout_helper_is_objArray(layout_helper()),
607 is_objArray_klass_slow()); }
608 inline bool is_typeArray_klass() const { return assert_same_query(
609 layout_helper_is_typeArray(layout_helper()),
610 is_typeArray_klass_slow()); }
611 #undef assert_same_query
612
613 // Access flags
614 AccessFlags access_flags() const { return _access_flags; }
615 void set_access_flags(AccessFlags flags) { _access_flags = flags; }
616
617 bool is_public() const { return _access_flags.is_public(); }
618 bool is_final() const { return _access_flags.is_final(); }
619 bool is_interface() const { return _access_flags.is_interface(); }
620 bool is_abstract() const { return _access_flags.is_abstract(); }
621 bool is_super() const { return _access_flags.is_super(); }
622 bool is_synthetic() const { return _access_flags.is_synthetic(); }
623 void set_is_synthetic() { _access_flags.set_is_synthetic(); }
624 bool has_finalizer() const { return _access_flags.has_finalizer(); }
625 bool has_final_method() const { return _access_flags.has_final_method(); }
626 void set_has_finalizer() { _access_flags.set_has_finalizer(); }
627 void set_has_final_method() { _access_flags.set_has_final_method(); }
628 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); }
629 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); }
630 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); }
631 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); }
632 bool is_shared() const { return access_flags().is_shared_class(); } // shadows MetaspaceObj::is_shared)()
633 void set_is_shared() { _access_flags.set_is_shared_class(); }
634 bool is_hidden() const { return access_flags().is_hidden_class(); }
635 void set_is_hidden() { _access_flags.set_is_hidden_class(); }
636 bool is_value_based() { return _access_flags.is_value_based_class(); }
637 void set_is_value_based() { _access_flags.set_is_value_based_class(); }
638
639 inline bool is_non_strong_hidden() const;
640
641 bool is_cloneable() const;
642 void set_is_cloneable();
643
644 markWord prototype_header() const { return _prototype_header; }
645 inline void set_prototype_header(markWord header);
646 static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); }
647
648 JFR_ONLY(DEFINE_TRACE_ID_METHODS;)
649
650 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
651 virtual MetaspaceObj::Type type() const { return ClassType; }
652
653 inline bool is_loader_alive() const;
654
655 void clean_subklass();
656
657 static void clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses = true);
658 static void clean_subklass_tree() {
659 clean_weak_klass_links(/*unloading_occurred*/ true , /* clean_alive_klasses */ false);
660 }
661
662 // Return self, except for abstract classes with exactly 1
663 // implementor. Then return the 1 concrete implementation.
664 Klass *up_cast_abstract();
665
666 // klass name
667 Symbol* name() const { return _name; }
668 void set_name(Symbol* n);
669
670 virtual void release_C_heap_structures(bool release_constant_pool = true);
671
672 public:
673 virtual jint compute_modifier_flags() const = 0;
674
675 // JVMTI support
676 virtual jint jvmti_class_status() const;
677
678 // Printing
679 virtual void print_on(outputStream* st) const;
680
681 virtual void oop_print_value_on(oop obj, outputStream* st);
682 virtual void oop_print_on (oop obj, outputStream* st);
683
684 virtual const char* internal_name() const = 0;
685
686 // Verification
687 virtual void verify_on(outputStream* st);
688 void verify() { verify_on(tty); }
689
690 #ifndef PRODUCT
691 bool verify_vtable_index(int index);
692 #endif
693
694 virtual void oop_verify_on(oop obj, outputStream* st);
695
696 // for error reporting
697 static bool is_valid(Klass* k);
698 };
699
700 #endif // SHARE_OOPS_KLASS_HPP