1 /*
2 * Copyright (c) 1997, 2013, 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_VM_OOPS_INSTANCEKLASS_HPP
26 #define SHARE_VM_OOPS_INSTANCEKLASS_HPP
27
28 #include "classfile/classLoaderData.hpp"
29 #include "oops/annotations.hpp"
30 #include "oops/constMethod.hpp"
31 #include "oops/fieldInfo.hpp"
32 #include "oops/instanceOop.hpp"
33 #include "oops/klassVtable.hpp"
34 #include "runtime/atomic.hpp"
35 #include "runtime/handles.hpp"
36 #include "runtime/os.hpp"
37 #include "utilities/accessFlags.hpp"
38 #include "utilities/bitMap.inline.hpp"
39 #include "utilities/macros.hpp"
40
41 // An InstanceKlass is the VM level representation of a Java class.
42 // It contains all information needed for at class at execution runtime.
43
44 // InstanceKlass layout:
45 // [C++ vtbl pointer ] Klass
46 // [subtype cache ] Klass
47 // [instance size ] Klass
48 // [java mirror ] Klass
49 // [super ] Klass
50 // [access_flags ] Klass
51 // [name ] Klass
52 // [first subklass ] Klass
53 // [next sibling ] Klass
54 // [array klasses ]
55 // [methods ]
56 // [local interfaces ]
57 // [transitive interfaces ]
58 // [fields ]
59 // [constants ]
60 // [class loader ]
61 // [protection domain ]
62 // [signers ]
63 // [source file name ]
64 // [inner classes ]
65 // [static field size ]
66 // [nonstatic field size ]
67 // [static oop fields size ]
68 // [nonstatic oop maps size ]
69 // [has finalize method ]
70 // [deoptimization mark bit ]
71 // [initialization state ]
72 // [initializing thread ]
73 // [Java vtable length ]
74 // [oop map cache (stack maps) ]
75 // [EMBEDDED Java vtable ] size in words = vtable_len
76 // [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
77 // The embedded nonstatic oop-map blocks are short pairs (offset, length)
78 // indicating where oops are located in instances of this klass.
79 // [EMBEDDED implementor of the interface] only exist for interface
80 // [EMBEDDED host klass ] only exist for an anonymous class (JSR 292 enabled)
81
82
83 // forward declaration for class -- see below for definition
84 class SuperTypeClosure;
85 class JNIid;
86 class jniIdMapBase;
87 class BreakpointInfo;
88 class fieldDescriptor;
89 class DepChange;
90 class nmethodBucket;
91 class PreviousVersionNode;
92 class JvmtiCachedClassFieldMap;
93 class MemberNameTable;
94
95 // This is used in iterators below.
96 class FieldClosure: public StackObj {
97 public:
98 virtual void do_field(fieldDescriptor* fd) = 0;
99 };
100
101 #ifndef PRODUCT
102 // Print fields.
103 // If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.
104 class FieldPrinter: public FieldClosure {
105 oop _obj;
106 outputStream* _st;
107 public:
108 FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}
109 void do_field(fieldDescriptor* fd);
110 };
111 #endif // !PRODUCT
112
113 // ValueObjs embedded in klass. Describes where oops are located in instances of
114 // this klass.
115 class OopMapBlock VALUE_OBJ_CLASS_SPEC {
116 public:
117 // Byte offset of the first oop mapped by this block.
118 int offset() const { return _offset; }
119 void set_offset(int offset) { _offset = offset; }
120
121 // Number of oops in this block.
122 uint count() const { return _count; }
123 void set_count(uint count) { _count = count; }
124
125 // sizeof(OopMapBlock) in HeapWords.
126 static const int size_in_words() {
127 return align_size_up(int(sizeof(OopMapBlock)), HeapWordSize) >>
128 LogHeapWordSize;
129 }
130
131 private:
132 int _offset;
133 uint _count;
134 };
135
136 class InstanceKlass: public Klass {
137 friend class VMStructs;
138 friend class ClassFileParser;
139 friend class CompileReplay;
140
141 protected:
142 // Constructor
143 InstanceKlass(int vtable_len,
144 int itable_len,
145 int static_field_size,
146 int nonstatic_oop_map_size,
147 ReferenceType rt,
148 AccessFlags access_flags,
149 bool is_anonymous);
150 public:
151 static Klass* allocate_instance_klass(ClassLoaderData* loader_data,
152 int vtable_len,
153 int itable_len,
154 int static_field_size,
155 int nonstatic_oop_map_size,
156 ReferenceType rt,
157 AccessFlags access_flags,
158 Symbol* name,
159 Klass* super_klass,
160 bool is_anonymous,
161 TRAPS);
162
163 InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
164
165 // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
166 // of the class loading & initialization procedure, and the use of the states.
167 enum ClassState {
168 allocated, // allocated (but not yet linked)
169 loaded, // loaded and inserted in class hierarchy (but not linked yet)
170 linked, // successfully linked/verified (but not initialized yet)
171 being_initialized, // currently running class initializer
172 fully_initialized, // initialized (successfull final state)
173 initialization_error // error happened during initialization
174 };
175
176 static int number_of_instance_classes() { return _total_instanceKlass_count; }
177
178 private:
179 static volatile int _total_instanceKlass_count;
180
181 protected:
182 // Protection domain.
183 oop _protection_domain;
184 // Class signers.
185 objArrayOop _signers;
186 // Initialization lock. Must be one per class and it has to be a VM internal
187 // object so java code cannot lock it (like the mirror)
188 // It has to be an object not a Mutex because it's held through java calls.
189 volatile oop _init_lock;
190
191 // Annotations for this class
192 Annotations* _annotations;
193 // Array classes holding elements of this class.
194 Klass* _array_klasses;
195 // Constant pool for this class.
196 ConstantPool* _constants;
197 // The InnerClasses attribute and EnclosingMethod attribute. The
198 // _inner_classes is an array of shorts. If the class has InnerClasses
199 // attribute, then the _inner_classes array begins with 4-tuples of shorts
200 // [inner_class_info_index, outer_class_info_index,
201 // inner_name_index, inner_class_access_flags] for the InnerClasses
202 // attribute. If the EnclosingMethod attribute exists, it occupies the
203 // last two shorts [class_index, method_index] of the array. If only
204 // the InnerClasses attribute exists, the _inner_classes array length is
205 // number_of_inner_classes * 4. If the class has both InnerClasses
206 // and EnclosingMethod attributes the _inner_classes array length is
207 // number_of_inner_classes * 4 + enclosing_method_attribute_size.
208 Array<jushort>* _inner_classes;
209
210 // Name of source file containing this klass, NULL if not specified.
211 Symbol* _source_file_name;
212 // the source debug extension for this klass, NULL if not specified.
213 // Specified as UTF-8 string without terminating zero byte in the classfile,
214 // it is stored in the instanceklass as a NULL-terminated UTF-8 string
215 char* _source_debug_extension;
216 // Generic signature, or null if none.
217 Symbol* _generic_signature;
218 // Array name derived from this class which needs unreferencing
219 // if this class is unloaded.
220 Symbol* _array_name;
221
222 // Number of heapOopSize words used by non-static fields in this klass
223 // (including inherited fields but after header_size()).
224 int _nonstatic_field_size;
225 int _static_field_size; // number words used by static fields (oop and non-oop) in this klass
226 u2 _static_oop_field_count;// number of static oop fields in this klass
227 u2 _java_fields_count; // The number of declared Java fields
228 int _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
229
230 // _is_marked_dependent can be set concurrently, thus cannot be part of the
231 // _misc_flags.
232 bool _is_marked_dependent; // used for marking during flushing and deoptimization
233
234 enum {
235 _misc_rewritten = 1 << 0, // methods rewritten.
236 _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
237 _misc_should_verify_class = 1 << 2, // allow caching of preverification
238 _misc_is_anonymous = 1 << 3, // has embedded _inner_classes field
239 _misc_is_contended = 1 << 4, // marked with contended annotation
240 _misc_has_default_methods = 1 << 5 // class/superclass/implemented interfaces has default methods
241 };
242 u2 _misc_flags;
243 u2 _minor_version; // minor version number of class file
244 u2 _major_version; // major version number of class file
245 Thread* _init_thread; // Pointer to current thread doing initialization (to handle recusive initialization)
246 int _vtable_len; // length of Java vtable (in words)
247 int _itable_len; // length of Java itable (in words)
248 OopMapCache* volatile _oop_map_cache; // OopMapCache for all methods in the klass (allocated lazily)
249 MemberNameTable* _member_names; // Member names
250 JNIid* _jni_ids; // First JNI identifier for static fields in this class
251 jmethodID* _methods_jmethod_ids; // jmethodIDs corresponding to method_idnum, or NULL if none
252 int* _methods_cached_itable_indices; // itable_index cache for JNI invoke corresponding to methods idnum, or NULL
253 nmethodBucket* _dependencies; // list of dependent nmethods
254 nmethod* _osr_nmethods_head; // Head of list of on-stack replacement nmethods for this class
255 BreakpointInfo* _breakpoints; // bpt lists, managed by Method*
256 // Array of interesting part(s) of the previous version(s) of this
257 // InstanceKlass. See PreviousVersionWalker below.
258 GrowableArray<PreviousVersionNode *>* _previous_versions;
259 // JVMTI fields can be moved to their own structure - see 6315920
260 unsigned char * _cached_class_file_bytes; // JVMTI: cached class file, before retransformable agent modified it in CFLH
261 jint _cached_class_file_len; // JVMTI: length of above
262
263 volatile u2 _idnum_allocated_count; // JNI/JVMTI: increments with the addition of methods, old ids don't change
264
265 // Class states are defined as ClassState (see above).
266 // Place the _init_state here to utilize the unused 2-byte after
267 // _idnum_allocated_count.
268 u1 _init_state; // state of class
269 u1 _reference_type; // reference type
270
271
272 JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map; // JVMTI: used during heap iteration
273
274 // Method array.
275 Array<Method*>* _methods;
276 // Interface (Klass*s) this class declares locally to implement.
277 Array<Klass*>* _local_interfaces;
278 // Interface (Klass*s) this class implements transitively.
279 Array<Klass*>* _transitive_interfaces;
280 // Int array containing the original order of method in the class file (for JVMTI).
281 Array<int>* _method_ordering;
282 // Instance and static variable information, starts with 6-tuples of shorts
283 // [access, name index, sig index, initval index, low_offset, high_offset]
284 // for all fields, followed by the generic signature data at the end of
285 // the array. Only fields with generic signature attributes have the generic
286 // signature data set in the array. The fields array looks like following:
287 //
288 // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
289 // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
290 // ...
291 // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
292 // [generic signature index]
293 // [generic signature index]
294 // ...
295 Array<u2>* _fields;
296
297 // embedded Java vtable follows here
298 // embedded Java itables follows here
299 // embedded static fields follows here
300 // embedded nonstatic oop-map blocks follows here
301 // embedded implementor of this interface follows here
302 // The embedded implementor only exists if the current klass is an
303 // iterface. The possible values of the implementor fall into following
304 // three cases:
305 // NULL: no implementor.
306 // A Klass* that's not itself: one implementor.
307 // Itsef: more than one implementors.
308 // embedded host klass follows here
309 // The embedded host klass only exists in an anonymous class for
310 // dynamic language support (JSR 292 enabled). The host class grants
311 // its access privileges to this class also. The host class is either
312 // named, or a previously loaded anonymous class. A non-anonymous class
313 // or an anonymous class loaded through normal classloading does not
314 // have this embedded field.
315 //
316
317 friend class SystemDictionary;
318
319 public:
320 bool has_nonstatic_fields() const {
321 return (_misc_flags & _misc_has_nonstatic_fields) != 0;
322 }
323 void set_has_nonstatic_fields(bool b) {
324 if (b) {
325 _misc_flags |= _misc_has_nonstatic_fields;
326 } else {
327 _misc_flags &= ~_misc_has_nonstatic_fields;
328 }
329 }
330
331 // field sizes
332 int nonstatic_field_size() const { return _nonstatic_field_size; }
333 void set_nonstatic_field_size(int size) { _nonstatic_field_size = size; }
334
335 int static_field_size() const { return _static_field_size; }
336 void set_static_field_size(int size) { _static_field_size = size; }
337
338 int static_oop_field_count() const { return (int)_static_oop_field_count; }
339 void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
340
341 // Java vtable
342 int vtable_length() const { return _vtable_len; }
343 void set_vtable_length(int len) { _vtable_len = len; }
344
345 // Java itable
346 int itable_length() const { return _itable_len; }
347 void set_itable_length(int len) { _itable_len = len; }
348
349 // array klasses
350 Klass* array_klasses() const { return _array_klasses; }
351 void set_array_klasses(Klass* k) { _array_klasses = k; }
352
353 // methods
354 Array<Method*>* methods() const { return _methods; }
355 void set_methods(Array<Method*>* a) { _methods = a; }
356 Method* method_with_idnum(int idnum);
357
358 // method ordering
359 Array<int>* method_ordering() const { return _method_ordering; }
360 void set_method_ordering(Array<int>* m) { _method_ordering = m; }
361
362 // interfaces
363 Array<Klass*>* local_interfaces() const { return _local_interfaces; }
364 void set_local_interfaces(Array<Klass*>* a) {
365 guarantee(_local_interfaces == NULL || a == NULL, "Just checking");
366 _local_interfaces = a; }
367 Array<Klass*>* transitive_interfaces() const { return _transitive_interfaces; }
368 void set_transitive_interfaces(Array<Klass*>* a) {
369 guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");
370 _transitive_interfaces = a; }
371
372 private:
373 friend class fieldDescriptor;
374 FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
375
376 public:
377 int field_offset (int index) const { return field(index)->offset(); }
378 int field_access_flags(int index) const { return field(index)->access_flags(); }
379 Symbol* field_name (int index) const { return field(index)->name(constants()); }
380 Symbol* field_signature (int index) const { return field(index)->signature(constants()); }
381
382 // Number of Java declared fields
383 int java_fields_count() const { return (int)_java_fields_count; }
384
385 Array<u2>* fields() const { return _fields; }
386
387 void set_fields(Array<u2>* f, u2 java_fields_count) {
388 guarantee(_fields == NULL || f == NULL, "Just checking");
389 _fields = f;
390 _java_fields_count = java_fields_count;
391 }
392
393 // inner classes
394 Array<u2>* inner_classes() const { return _inner_classes; }
395 void set_inner_classes(Array<u2>* f) { _inner_classes = f; }
396
397 enum InnerClassAttributeOffset {
398 // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
399 inner_class_inner_class_info_offset = 0,
400 inner_class_outer_class_info_offset = 1,
401 inner_class_inner_name_offset = 2,
402 inner_class_access_flags_offset = 3,
403 inner_class_next_offset = 4
404 };
405
406 enum EnclosingMethodAttributeOffset {
407 enclosing_method_class_index_offset = 0,
408 enclosing_method_method_index_offset = 1,
409 enclosing_method_attribute_size = 2
410 };
411
412 // method override check
413 bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
414
415 // package
416 bool is_same_class_package(Klass* class2);
417 bool is_same_class_package(oop classloader2, Symbol* classname2);
418 static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
419
420 // find an enclosing class (defined where original code was, in jvm.cpp!)
421 Klass* compute_enclosing_class(bool* inner_is_member, TRAPS) {
422 instanceKlassHandle self(THREAD, this);
423 return compute_enclosing_class_impl(self, inner_is_member, THREAD);
424 }
425 static Klass* compute_enclosing_class_impl(instanceKlassHandle self,
426 bool* inner_is_member, TRAPS);
427
428 // tell if two classes have the same enclosing class (at package level)
429 bool is_same_package_member(Klass* class2, TRAPS) {
430 instanceKlassHandle self(THREAD, this);
431 return is_same_package_member_impl(self, class2, THREAD);
432 }
433 static bool is_same_package_member_impl(instanceKlassHandle self,
434 Klass* class2, TRAPS);
435
436 // initialization state
437 bool is_loaded() const { return _init_state >= loaded; }
438 bool is_linked() const { return _init_state >= linked; }
439 bool is_initialized() const { return _init_state == fully_initialized; }
440 bool is_not_initialized() const { return _init_state < being_initialized; }
441 bool is_being_initialized() const { return _init_state == being_initialized; }
442 bool is_in_error_state() const { return _init_state == initialization_error; }
443 bool is_reentrant_initialization(Thread *thread) { return thread == _init_thread; }
444 ClassState init_state() { return (ClassState)_init_state; }
445 bool is_rewritten() const { return (_misc_flags & _misc_rewritten) != 0; }
446
447 // defineClass specified verification
448 bool should_verify_class() const {
449 return (_misc_flags & _misc_should_verify_class) != 0;
450 }
451 void set_should_verify_class(bool value) {
452 if (value) {
453 _misc_flags |= _misc_should_verify_class;
454 } else {
455 _misc_flags &= ~_misc_should_verify_class;
456 }
457 }
458
459 // marking
460 bool is_marked_dependent() const { return _is_marked_dependent; }
461 void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
462
463 // initialization (virtuals from Klass)
464 bool should_be_initialized() const; // means that initialize should be called
465 void initialize(TRAPS);
466 void link_class(TRAPS);
467 bool link_class_or_fail(TRAPS); // returns false on failure
468 void unlink_class();
469 void rewrite_class(TRAPS);
470 void link_methods(TRAPS);
471 Method* class_initializer();
472
473 // set the class to initialized if no static initializer is present
474 void eager_initialize(Thread *thread);
475
476 // reference type
477 ReferenceType reference_type() const { return (ReferenceType)_reference_type; }
478 void set_reference_type(ReferenceType t) {
479 assert(t == (u1)t, "overflow");
480 _reference_type = (u1)t;
481 }
482
483 static ByteSize reference_type_offset() { return in_ByteSize(offset_of(InstanceKlass, _reference_type)); }
484
485 // find local field, returns true if found
486 bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
487 // find field in direct superinterfaces, returns the interface in which the field is defined
488 Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
489 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
490 Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
491 // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
492 Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
493
494 // find a non-static or static field given its offset within the class.
495 bool contains_field_offset(int offset) {
496 return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
497 }
498
499 bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
500 bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
501
502 // find a local method (returns NULL if not found)
503 Method* find_method(Symbol* name, Symbol* signature) const;
504 static Method* find_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
505
506 // lookup operation (returns NULL if not found)
507 Method* uncached_lookup_method(Symbol* name, Symbol* signature) const;
508
509 // lookup a method in all the interfaces that this class implements
510 // (returns NULL if not found)
511 Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature) const;
512
513 // Find method indices by name. If a method with the specified name is
514 // found the index to the first method is returned, and 'end' is filled in
515 // with the index of first non-name-matching method. If no method is found
516 // -1 is returned.
517 int find_method_by_name(Symbol* name, int* end);
518 static int find_method_by_name(Array<Method*>* methods, Symbol* name, int* end);
519
520 // constant pool
521 ConstantPool* constants() const { return _constants; }
522 void set_constants(ConstantPool* c) { _constants = c; }
523
524 // protection domain
525 oop protection_domain() { return _protection_domain; }
526 void set_protection_domain(oop pd) { klass_oop_store(&_protection_domain, pd); }
527
528 // host class
529 Klass* host_klass() const {
530 Klass** hk = (Klass**)adr_host_klass();
531 if (hk == NULL) {
532 return NULL;
533 } else {
534 return *hk;
535 }
536 }
537 void set_host_klass(Klass* host) {
538 assert(is_anonymous(), "not anonymous");
539 Klass** addr = (Klass**)adr_host_klass();
540 assert(addr != NULL, "no reversed space");
541 *addr = host;
542 }
543 bool is_anonymous() const {
544 return (_misc_flags & _misc_is_anonymous) != 0;
545 }
546 void set_is_anonymous(bool value) {
547 if (value) {
548 _misc_flags |= _misc_is_anonymous;
549 } else {
550 _misc_flags &= ~_misc_is_anonymous;
551 }
552 }
553
554 // Oop that keeps the metadata for this class from being unloaded
555 // in places where the metadata is stored in other places, like nmethods
556 oop klass_holder() const {
557 return is_anonymous() ? java_mirror() : class_loader();
558 }
559
560 bool is_contended() const {
561 return (_misc_flags & _misc_is_contended) != 0;
562 }
563 void set_is_contended(bool value) {
564 if (value) {
565 _misc_flags |= _misc_is_contended;
566 } else {
567 _misc_flags &= ~_misc_is_contended;
568 }
569 }
570
571 // signers
572 objArrayOop signers() const { return _signers; }
573 void set_signers(objArrayOop s) { klass_oop_store((oop*)&_signers, s); }
574
575 // source file name
576 Symbol* source_file_name() const { return _source_file_name; }
577 void set_source_file_name(Symbol* n);
578
579 // minor and major version numbers of class file
580 u2 minor_version() const { return _minor_version; }
581 void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
582 u2 major_version() const { return _major_version; }
583 void set_major_version(u2 major_version) { _major_version = major_version; }
584
585 // source debug extension
586 char* source_debug_extension() const { return _source_debug_extension; }
587 void set_source_debug_extension(char* array, int length);
588
589 // symbol unloading support (refcount already added)
590 Symbol* array_name() { return _array_name; }
591 void set_array_name(Symbol* name) { assert(_array_name == NULL, "name already created"); _array_name = name; }
592
593 // nonstatic oop-map blocks
594 static int nonstatic_oop_map_size(unsigned int oop_map_count) {
595 return oop_map_count * OopMapBlock::size_in_words();
596 }
597 unsigned int nonstatic_oop_map_count() const {
598 return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
599 }
600 int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
601 void set_nonstatic_oop_map_size(int words) {
602 _nonstatic_oop_map_size = words;
603 }
604
605 // RedefineClasses() support for previous versions:
606 void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
607 int emcp_method_count);
608 // If the _previous_versions array is non-NULL, then this klass
609 // has been redefined at least once even if we aren't currently
610 // tracking a previous version.
611 bool has_been_redefined() const { return _previous_versions != NULL; }
612 bool has_previous_version() const;
613 void init_previous_versions() {
614 _previous_versions = NULL;
615 }
616 GrowableArray<PreviousVersionNode *>* previous_versions() const {
617 return _previous_versions;
618 }
619
620 static void purge_previous_versions(InstanceKlass* ik);
621
622 // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
623 void set_cached_class_file(unsigned char *class_file_bytes,
624 jint class_file_len) { _cached_class_file_len = class_file_len;
625 _cached_class_file_bytes = class_file_bytes; }
626 jint get_cached_class_file_len() { return _cached_class_file_len; }
627 unsigned char * get_cached_class_file_bytes() { return _cached_class_file_bytes; }
628
629 // JVMTI: Support for caching of field indices, types, and offsets
630 void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
631 _jvmti_cached_class_field_map = descriptor;
632 }
633 JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
634 return _jvmti_cached_class_field_map;
635 }
636
637 bool has_default_methods() const {
638 return (_misc_flags & _misc_has_default_methods) != 0;
639 }
640 void set_has_default_methods(bool b) {
641 if (b) {
642 _misc_flags |= _misc_has_default_methods;
643 } else {
644 _misc_flags &= ~_misc_has_default_methods;
645 }
646 }
647
648 // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
649 inline u2 next_method_idnum();
650 void set_initial_method_idnum(u2 value) { _idnum_allocated_count = value; }
651
652 // generics support
653 Symbol* generic_signature() const { return _generic_signature; }
654 void set_generic_signature(Symbol* sig) { _generic_signature = sig; }
655
656 u2 enclosing_method_data(int offset);
657 u2 enclosing_method_class_index() {
658 return enclosing_method_data(enclosing_method_class_index_offset);
659 }
660 u2 enclosing_method_method_index() {
661 return enclosing_method_data(enclosing_method_method_index_offset);
662 }
663 void set_enclosing_method_indices(u2 class_index,
664 u2 method_index);
665
666 // jmethodID support
667 static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
668 methodHandle method_h);
669 static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
670 size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
671 jmethodID* to_dealloc_id_p,
672 jmethodID** to_dealloc_jmeths_p);
673 static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
674 size_t *length_p, jmethodID* id_p);
675 jmethodID jmethod_id_or_null(Method* method);
676
677 // cached itable index support
678 void set_cached_itable_index(size_t idnum, int index);
679 int cached_itable_index(size_t idnum);
680
681 // annotations support
682 Annotations* annotations() const { return _annotations; }
683 void set_annotations(Annotations* anno) { _annotations = anno; }
684
685 AnnotationArray* class_annotations() const {
686 return (_annotations != NULL) ? _annotations->class_annotations() : NULL;
687 }
688 Array<AnnotationArray*>* fields_annotations() const {
689 return (_annotations != NULL) ? _annotations->fields_annotations() : NULL;
690 }
691 AnnotationArray* class_type_annotations() const {
692 return (_annotations != NULL) ? _annotations->class_type_annotations() : NULL;
693 }
694 Array<AnnotationArray*>* fields_type_annotations() const {
695 return (_annotations != NULL) ? _annotations->fields_type_annotations() : NULL;
696 }
697 // allocation
698 instanceOop allocate_instance(TRAPS);
699
700 // additional member function to return a handle
701 instanceHandle allocate_instance_handle(TRAPS) { return instanceHandle(THREAD, allocate_instance(THREAD)); }
702
703 objArrayOop allocate_objArray(int n, int length, TRAPS);
704 // Helper function
705 static instanceOop register_finalizer(instanceOop i, TRAPS);
706
707 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
708 // if not, throw either an Error or an Exception.
709 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
710
711 // initialization
712 void call_class_initializer(TRAPS);
713 void set_initialization_state_and_notify(ClassState state, TRAPS);
714
715 // OopMapCache support
716 OopMapCache* oop_map_cache() { return _oop_map_cache; }
717 void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
718 void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
719
720 // JNI identifier support (for static fields - for jni performance)
721 JNIid* jni_ids() { return _jni_ids; }
722 void set_jni_ids(JNIid* ids) { _jni_ids = ids; }
723 JNIid* jni_id_for(int offset);
724
725 // maintenance of deoptimization dependencies
726 int mark_dependent_nmethods(DepChange& changes);
727 void add_dependent_nmethod(nmethod* nm);
728 void remove_dependent_nmethod(nmethod* nm);
729
730 // On-stack replacement support
731 nmethod* osr_nmethods_head() const { return _osr_nmethods_head; };
732 void set_osr_nmethods_head(nmethod* h) { _osr_nmethods_head = h; };
733 void add_osr_nmethod(nmethod* n);
734 void remove_osr_nmethod(nmethod* n);
735 nmethod* lookup_osr_nmethod(Method* const m, int bci, int level, bool match_level) const;
736
737 // Breakpoint support (see methods on Method* for details)
738 BreakpointInfo* breakpoints() const { return _breakpoints; };
739 void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
740
741 // support for stub routines
742 static ByteSize init_state_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_state)); }
743 TRACE_DEFINE_OFFSET;
744 static ByteSize init_thread_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_thread)); }
745
746 // subclass/subinterface checks
747 bool implements_interface(Klass* k) const;
748
749 // Access to the implementor of an interface.
750 Klass* implementor() const
751 {
752 Klass** k = adr_implementor();
753 if (k == NULL) {
754 return NULL;
755 } else {
756 return *k;
757 }
758 }
759
760 void set_implementor(Klass* k) {
761 assert(is_interface(), "not interface");
762 Klass** addr = adr_implementor();
763 *addr = k;
764 }
765
766 int nof_implementors() const {
767 Klass* k = implementor();
768 if (k == NULL) {
769 return 0;
770 } else if (k != this) {
771 return 1;
772 } else {
773 return 2;
774 }
775 }
776
777 void add_implementor(Klass* k); // k is a new class that implements this interface
778 void init_implementor(); // initialize
779
780 // link this class into the implementors list of every interface it implements
781 void process_interfaces(Thread *thread);
782
783 // virtual operations from Klass
784 bool is_leaf_class() const { return _subklass == NULL; }
785 GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
786 bool compute_is_subtype_of(Klass* k);
787 bool can_be_primary_super_slow() const;
788 int oop_size(oop obj) const { return size_helper(); }
789 bool oop_is_instance_slow() const { return true; }
790
791 // Iterators
792 void do_local_static_fields(FieldClosure* cl);
793 void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
794 void do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS);
795
796 void methods_do(void f(Method* method));
797 void array_klasses_do(void f(Klass* k));
798 void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
799 void with_array_klasses_do(void f(Klass* k));
800 bool super_types_do(SuperTypeClosure* blk);
801
802 // Casting from Klass*
803 static InstanceKlass* cast(Klass* k) {
804 assert(k->is_klass(), "must be");
805 assert(k->oop_is_instance(), "cast to InstanceKlass");
806 return (InstanceKlass*) k;
807 }
808
809 InstanceKlass* java_super() const {
810 return (super() == NULL) ? NULL : cast(super());
811 }
812
813 // Sizing (in words)
814 static int header_size() { return align_object_offset(sizeof(InstanceKlass)/HeapWordSize); }
815
816 static int size(int vtable_length, int itable_length,
817 int nonstatic_oop_map_size,
818 bool is_interface, bool is_anonymous) {
819 return align_object_size(header_size() +
820 align_object_offset(vtable_length) +
821 align_object_offset(itable_length) +
822 ((is_interface || is_anonymous) ?
823 align_object_offset(nonstatic_oop_map_size) :
824 nonstatic_oop_map_size) +
825 (is_interface ? (int)sizeof(Klass*)/HeapWordSize : 0) +
826 (is_anonymous ? (int)sizeof(Klass*)/HeapWordSize : 0));
827 }
828 int size() const { return size(vtable_length(),
829 itable_length(),
830 nonstatic_oop_map_size(),
831 is_interface(),
832 is_anonymous());
833 }
834 #if INCLUDE_SERVICES
835 virtual void collect_statistics(KlassSizeStats *sz) const;
836 #endif
837
838 static int vtable_start_offset() { return header_size(); }
839 static int vtable_length_offset() { return offset_of(InstanceKlass, _vtable_len) / HeapWordSize; }
840
841 intptr_t* start_of_vtable() const { return ((intptr_t*)this) + vtable_start_offset(); }
842 intptr_t* start_of_itable() const { return start_of_vtable() + align_object_offset(vtable_length()); }
843 int itable_offset_in_words() const { return start_of_itable() - (intptr_t*)this; }
844
845 intptr_t* end_of_itable() const { return start_of_itable() + itable_length(); }
846
847 address static_field_addr(int offset);
848
849 OopMapBlock* start_of_nonstatic_oop_maps() const {
850 return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
851 }
852
853 Klass** end_of_nonstatic_oop_maps() const {
854 return (Klass**)(start_of_nonstatic_oop_maps() +
855 nonstatic_oop_map_count());
856 }
857
858 Klass** adr_implementor() const {
859 if (is_interface()) {
860 return (Klass**)end_of_nonstatic_oop_maps();
861 } else {
862 return NULL;
863 }
864 };
865
866 Klass** adr_host_klass() const {
867 if (is_anonymous()) {
868 Klass** adr_impl = adr_implementor();
869 if (adr_impl != NULL) {
870 return adr_impl + 1;
871 } else {
872 return end_of_nonstatic_oop_maps();
873 }
874 } else {
875 return NULL;
876 }
877 }
878
879 // Allocation profiling support
880 juint alloc_size() const { return _alloc_count * size_helper(); }
881 void set_alloc_size(juint n) {}
882
883 // Use this to return the size of an instance in heap words:
884 int size_helper() const {
885 return layout_helper_to_size_helper(layout_helper());
886 }
887
888 // This bit is initialized in classFileParser.cpp.
889 // It is false under any of the following conditions:
890 // - the class is abstract (including any interface)
891 // - the class has a finalizer (if !RegisterFinalizersAtInit)
892 // - the class size is larger than FastAllocateSizeLimit
893 // - the class is java/lang/Class, which cannot be allocated directly
894 bool can_be_fastpath_allocated() const {
895 return !layout_helper_needs_slow_path(layout_helper());
896 }
897
898 // Java vtable/itable
899 klassVtable* vtable() const; // return new klassVtable wrapper
900 inline Method* method_at_vtable(int index);
901 klassItable* itable() const; // return new klassItable wrapper
902 Method* method_at_itable(Klass* holder, int index, TRAPS);
903
904 // Garbage collection
905 virtual void oops_do(OopClosure* cl);
906
907 void oop_follow_contents(oop obj);
908 int oop_adjust_pointers(oop obj);
909
910 void clean_implementors_list(BoolObjectClosure* is_alive);
911 void clean_method_data(BoolObjectClosure* is_alive);
912
913 // Explicit metaspace deallocation of fields
914 // For RedefineClasses, we need to deallocate instanceKlasses
915 void deallocate_contents(ClassLoaderData* loader_data);
916
917 // The constant pool is on stack if any of the methods are executing or
918 // referenced by handles.
919 bool on_stack() const { return _constants->on_stack(); }
920
921 void release_C_heap_structures();
922
923 // Parallel Scavenge and Parallel Old
924 PARALLEL_GC_DECLS
925
926 // Naming
927 const char* signature_name() const;
928
929 // Iterators
930 int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) {
931 return oop_oop_iterate_v(obj, blk);
932 }
933
934 int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) {
935 return oop_oop_iterate_v_m(obj, blk, mr);
936 }
937
938 #define InstanceKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
939 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \
940 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, \
941 MemRegion mr);
942
943 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DECL)
944 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DECL)
945
946 #if INCLUDE_ALL_GCS
947 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
948 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
949
950 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
951 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
952 #endif // INCLUDE_ALL_GCS
953
954 u2 idnum_allocated_count() const { return _idnum_allocated_count; }
955 private:
956 // initialization state
957 #ifdef ASSERT
958 void set_init_state(ClassState state);
959 #else
960 void set_init_state(ClassState state) { _init_state = (u1)state; }
961 #endif
962 void set_rewritten() { _misc_flags |= _misc_rewritten; }
963 void set_init_thread(Thread *thread) { _init_thread = thread; }
964
965 // The RedefineClasses() API can cause new method idnums to be needed
966 // which will cause the caches to grow. Safety requires different
967 // cache management logic if the caches can grow instead of just
968 // going from NULL to non-NULL.
969 bool idnum_can_increment() const { return has_been_redefined(); }
970 jmethodID* methods_jmethod_ids_acquire() const
971 { return (jmethodID*)OrderAccess::load_ptr_acquire(&_methods_jmethod_ids); }
972 void release_set_methods_jmethod_ids(jmethodID* jmeths)
973 { OrderAccess::release_store_ptr(&_methods_jmethod_ids, jmeths); }
974
975 int* methods_cached_itable_indices_acquire() const
976 { return (int*)OrderAccess::load_ptr_acquire(&_methods_cached_itable_indices); }
977 void release_set_methods_cached_itable_indices(int* indices)
978 { OrderAccess::release_store_ptr(&_methods_cached_itable_indices, indices); }
979
980 // Lock during initialization
981 volatile oop init_lock() const;
982 void set_init_lock(oop value) { klass_oop_store(&_init_lock, value); }
983 void fence_and_clear_init_lock(); // after fully_initialized
984
985 // Offsets for memory management
986 oop* adr_protection_domain() const { return (oop*)&this->_protection_domain;}
987 oop* adr_signers() const { return (oop*)&this->_signers;}
988 oop* adr_init_lock() const { return (oop*)&this->_init_lock;}
989
990 // Static methods that are used to implement member methods where an exposed this pointer
991 // is needed due to possible GCs
992 static bool link_class_impl (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
993 static bool verify_code (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
994 static void initialize_impl (instanceKlassHandle this_oop, TRAPS);
995 static void eager_initialize_impl (instanceKlassHandle this_oop);
996 static void set_initialization_state_and_notify_impl (instanceKlassHandle this_oop, ClassState state, TRAPS);
997 static void call_class_initializer_impl (instanceKlassHandle this_oop, TRAPS);
998 static Klass* array_klass_impl (instanceKlassHandle this_oop, bool or_null, int n, TRAPS);
999 static void do_local_static_fields_impl (instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS);
1000 /* jni_id_for_impl for jfieldID only */
1001 static JNIid* jni_id_for_impl (instanceKlassHandle this_oop, int offset);
1002
1003 // Returns the array class for the n'th dimension
1004 Klass* array_klass_impl(bool or_null, int n, TRAPS);
1005
1006 // Returns the array class with this class as element type
1007 Klass* array_klass_impl(bool or_null, TRAPS);
1008
1009 public:
1010 // CDS support - remove and restore oops from metadata. Oops are not shared.
1011 virtual void remove_unshareable_info();
1012 virtual void restore_unshareable_info(TRAPS);
1013
1014 // jvm support
1015 jint compute_modifier_flags(TRAPS) const;
1016
1017 // JSR-292 support
1018 MemberNameTable* member_names() { return _member_names; }
1019 void set_member_names(MemberNameTable* member_names) { _member_names = member_names; }
1020 void add_member_name(oop mem_name);
1021
1022 public:
1023 // JVMTI support
1024 jint jvmti_class_status() const;
1025
1026 public:
1027 // Printing
1028 #ifndef PRODUCT
1029 void print_on(outputStream* st) const;
1030 #endif
1031 void print_value_on(outputStream* st) const;
1032
1033 void oop_print_value_on(oop obj, outputStream* st);
1034
1035 #ifndef PRODUCT
1036 void oop_print_on (oop obj, outputStream* st);
1037
1038 void print_dependent_nmethods(bool verbose = false);
1039 bool is_dependent_nmethod(nmethod* nm);
1040 #endif
1041
1042 const char* internal_name() const;
1043
1044 // Verification
1045 void verify_on(outputStream* st);
1046
1047 void oop_verify_on(oop obj, outputStream* st);
1048 };
1049
1050 inline Method* InstanceKlass::method_at_vtable(int index) {
1051 #ifndef PRODUCT
1052 assert(index >= 0, "valid vtable index");
1053 if (DebugVtables) {
1054 verify_vtable_index(index);
1055 }
1056 #endif
1057 vtableEntry* ve = (vtableEntry*)start_of_vtable();
1058 return ve[index].method();
1059 }
1060
1061 // for adding methods
1062 // UNSET_IDNUM return means no more ids available
1063 inline u2 InstanceKlass::next_method_idnum() {
1064 if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1065 return ConstMethod::UNSET_IDNUM; // no more ids available
1066 } else {
1067 return _idnum_allocated_count++;
1068 }
1069 }
1070
1071
1072 /* JNIid class for jfieldIDs only */
1073 class JNIid: public CHeapObj<mtClass> {
1074 friend class VMStructs;
1075 private:
1076 Klass* _holder;
1077 JNIid* _next;
1078 int _offset;
1079 #ifdef ASSERT
1080 bool _is_static_field_id;
1081 #endif
1082
1083 public:
1084 // Accessors
1085 Klass* holder() const { return _holder; }
1086 int offset() const { return _offset; }
1087 JNIid* next() { return _next; }
1088 // Constructor
1089 JNIid(Klass* holder, int offset, JNIid* next);
1090 // Identifier lookup
1091 JNIid* find(int offset);
1092
1093 bool find_local_field(fieldDescriptor* fd) {
1094 return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1095 }
1096
1097 static void deallocate(JNIid* id);
1098 // Debugging
1099 #ifdef ASSERT
1100 bool is_static_field_id() const { return _is_static_field_id; }
1101 void set_is_static_field_id() { _is_static_field_id = true; }
1102 #endif
1103 void verify(Klass* holder);
1104 };
1105
1106
1107 // If breakpoints are more numerous than just JVMTI breakpoints,
1108 // consider compressing this data structure.
1109 // It is currently a simple linked list defined in method.hpp.
1110
1111 class BreakpointInfo;
1112
1113
1114 // A collection point for interesting information about the previous
1115 // version(s) of an InstanceKlass. This class uses weak references to
1116 // the information so that the information may be collected as needed
1117 // by the system. If the information is shared, then a regular
1118 // reference must be used because a weak reference would be seen as
1119 // collectible. A GrowableArray of PreviousVersionNodes is attached
1120 // to the InstanceKlass as needed. See PreviousVersionWalker below.
1121 class PreviousVersionNode : public CHeapObj<mtClass> {
1122 private:
1123 // A shared ConstantPool is never collected so we'll always have
1124 // a reference to it so we can update items in the cache. We'll
1125 // have a weak reference to a non-shared ConstantPool until all
1126 // of the methods (EMCP or obsolete) have been collected; the
1127 // non-shared ConstantPool becomes collectible at that point.
1128 ConstantPool* _prev_constant_pool; // regular or weak reference
1129 bool _prev_cp_is_weak; // true if not a shared ConstantPool
1130
1131 // If the previous version of the InstanceKlass doesn't have any
1132 // EMCP methods, then _prev_EMCP_methods will be NULL. If all the
1133 // EMCP methods have been collected, then _prev_EMCP_methods can
1134 // have a length of zero.
1135 GrowableArray<Method*>* _prev_EMCP_methods;
1136
1137 public:
1138 PreviousVersionNode(ConstantPool* prev_constant_pool, bool prev_cp_is_weak,
1139 GrowableArray<Method*>* prev_EMCP_methods);
1140 ~PreviousVersionNode();
1141 ConstantPool* prev_constant_pool() const {
1142 return _prev_constant_pool;
1143 }
1144 GrowableArray<Method*>* prev_EMCP_methods() const {
1145 return _prev_EMCP_methods;
1146 }
1147 };
1148
1149
1150 // A Handle-ized version of PreviousVersionNode.
1151 class PreviousVersionInfo : public ResourceObj {
1152 private:
1153 constantPoolHandle _prev_constant_pool_handle;
1154 // If the previous version of the InstanceKlass doesn't have any
1155 // EMCP methods, then _prev_EMCP_methods will be NULL. Since the
1156 // methods cannot be collected while we hold a handle,
1157 // _prev_EMCP_methods should never have a length of zero.
1158 GrowableArray<methodHandle>* _prev_EMCP_method_handles;
1159
1160 public:
1161 PreviousVersionInfo(PreviousVersionNode *pv_node);
1162 ~PreviousVersionInfo();
1163 constantPoolHandle prev_constant_pool_handle() const {
1164 return _prev_constant_pool_handle;
1165 }
1166 GrowableArray<methodHandle>* prev_EMCP_method_handles() const {
1167 return _prev_EMCP_method_handles;
1168 }
1169 };
1170
1171
1172 // Helper object for walking previous versions. This helper cleans up
1173 // the Handles that it allocates when the helper object is destroyed.
1174 // The PreviousVersionInfo object returned by next_previous_version()
1175 // is only valid until a subsequent call to next_previous_version() or
1176 // the helper object is destroyed.
1177 class PreviousVersionWalker : public StackObj {
1178 private:
1179 GrowableArray<PreviousVersionNode *>* _previous_versions;
1180 int _current_index;
1181 // Fields for cleaning up when we are done walking the previous versions:
1182 // A HandleMark for the PreviousVersionInfo handles:
1183 HandleMark _hm;
1184
1185 // It would be nice to have a ResourceMark field in this helper also,
1186 // but the ResourceMark code says to be careful to delete handles held
1187 // in GrowableArrays _before_ deleting the GrowableArray. Since we
1188 // can't guarantee the order in which the fields are destroyed, we
1189 // have to let the creator of the PreviousVersionWalker object do
1190 // the right thing. Also, adding a ResourceMark here causes an
1191 // include loop.
1192
1193 // A pointer to the current info object so we can handle the deletes.
1194 PreviousVersionInfo * _current_p;
1195
1196 public:
1197 PreviousVersionWalker(InstanceKlass *ik);
1198 ~PreviousVersionWalker();
1199
1200 // Return the interesting information for the next previous version
1201 // of the klass. Returns NULL if there are no more previous versions.
1202 PreviousVersionInfo* next_previous_version();
1203 };
1204
1205
1206 //
1207 // nmethodBucket is used to record dependent nmethods for
1208 // deoptimization. nmethod dependencies are actually <klass, method>
1209 // pairs but we really only care about the klass part for purposes of
1210 // finding nmethods which might need to be deoptimized. Instead of
1211 // recording the method, a count of how many times a particular nmethod
1212 // was recorded is kept. This ensures that any recording errors are
1213 // noticed since an nmethod should be removed as many times are it's
1214 // added.
1215 //
1216 class nmethodBucket: public CHeapObj<mtClass> {
1217 friend class VMStructs;
1218 private:
1219 nmethod* _nmethod;
1220 int _count;
1221 nmethodBucket* _next;
1222
1223 public:
1224 nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
1225 _nmethod = nmethod;
1226 _next = next;
1227 _count = 1;
1228 }
1229 int count() { return _count; }
1230 int increment() { _count += 1; return _count; }
1231 int decrement() { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
1232 nmethodBucket* next() { return _next; }
1233 void set_next(nmethodBucket* b) { _next = b; }
1234 nmethod* get_nmethod() { return _nmethod; }
1235 };
1236
1237 // An iterator that's used to access the inner classes indices in the
1238 // InstanceKlass::_inner_classes array.
1239 class InnerClassesIterator : public StackObj {
1240 private:
1241 Array<jushort>* _inner_classes;
1242 int _length;
1243 int _idx;
1244 public:
1245
1246 InnerClassesIterator(instanceKlassHandle k) {
1247 _inner_classes = k->inner_classes();
1248 if (k->inner_classes() != NULL) {
1249 _length = _inner_classes->length();
1250 // The inner class array's length should be the multiple of
1251 // inner_class_next_offset if it only contains the InnerClasses
1252 // attribute data, or it should be
1253 // n*inner_class_next_offset+enclosing_method_attribute_size
1254 // if it also contains the EnclosingMethod data.
1255 assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1256 _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1257 "just checking");
1258 // Remove the enclosing_method portion if exists.
1259 if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1260 _length -= InstanceKlass::enclosing_method_attribute_size;
1261 }
1262 } else {
1263 _length = 0;
1264 }
1265 _idx = 0;
1266 }
1267
1268 int length() const {
1269 return _length;
1270 }
1271
1272 void next() {
1273 _idx += InstanceKlass::inner_class_next_offset;
1274 }
1275
1276 bool done() const {
1277 return (_idx >= _length);
1278 }
1279
1280 u2 inner_class_info_index() const {
1281 return _inner_classes->at(
1282 _idx + InstanceKlass::inner_class_inner_class_info_offset);
1283 }
1284
1285 void set_inner_class_info_index(u2 index) {
1286 _inner_classes->at_put(
1287 _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1288 }
1289
1290 u2 outer_class_info_index() const {
1291 return _inner_classes->at(
1292 _idx + InstanceKlass::inner_class_outer_class_info_offset);
1293 }
1294
1295 void set_outer_class_info_index(u2 index) {
1296 _inner_classes->at_put(
1297 _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1298 }
1299
1300 u2 inner_name_index() const {
1301 return _inner_classes->at(
1302 _idx + InstanceKlass::inner_class_inner_name_offset);
1303 }
1304
1305 void set_inner_name_index(u2 index) {
1306 _inner_classes->at_put(
1307 _idx + InstanceKlass::inner_class_inner_name_offset, index);
1308 }
1309
1310 u2 inner_access_flags() const {
1311 return _inner_classes->at(
1312 _idx + InstanceKlass::inner_class_access_flags_offset);
1313 }
1314 };
1315
1316 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP