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 "memory/referenceType.hpp"
30 #include "oops/annotations.hpp"
31 #include "oops/constMethod.hpp"
32 #include "oops/fieldInfo.hpp"
33 #include "oops/instanceOop.hpp"
34 #include "oops/klassVtable.hpp"
35 #include "runtime/atomic.hpp"
36 #include "runtime/handles.hpp"
37 #include "runtime/os.hpp"
38 #include "utilities/accessFlags.hpp"
39 #include "utilities/bitMap.inline.hpp"
40 #include "utilities/macros.hpp"
41 #include "trace/traceMacros.hpp"
42
43 // An InstanceKlass is the VM level representation of a Java class.
44 // It contains all information needed for at class at execution runtime.
45
46 // InstanceKlass layout:
47 // [C++ vtbl pointer ] Klass
48 // [subtype cache ] Klass
49 // [instance size ] Klass
50 // [java mirror ] Klass
51 // [super ] Klass
52 // [access_flags ] Klass
53 // [name ] Klass
54 // [first subklass ] Klass
55 // [next sibling ] Klass
56 // [array klasses ]
57 // [methods ]
58 // [local interfaces ]
59 // [transitive interfaces ]
60 // [fields ]
61 // [constants ]
62 // [class loader ]
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 InstanceKlass* allocate_instance_klass(
152 ClassLoaderData* loader_data,
153 int vtable_len,
154 int itable_len,
155 int static_field_size,
156 int nonstatic_oop_map_size,
157 ReferenceType rt,
158 AccessFlags access_flags,
159 Symbol* name,
160 Klass* super_klass,
161 bool is_anonymous,
162 TRAPS);
163
164 InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
165
166 // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
167 // of the class loading & initialization procedure, and the use of the states.
168 enum ClassState {
169 allocated, // allocated (but not yet linked)
170 loaded, // loaded and inserted in class hierarchy (but not linked yet)
171 linked, // successfully linked/verified (but not initialized yet)
172 being_initialized, // currently running class initializer
173 fully_initialized, // initialized (successfull final state)
174 initialization_error // error happened during initialization
175 };
176
177 static int number_of_instance_classes() { return _total_instanceKlass_count; }
178
179 private:
180 static volatile int _total_instanceKlass_count;
181
182 protected:
183 // Annotations for this class
184 Annotations* _annotations;
185 // Array classes holding elements of this class.
186 Klass* _array_klasses;
187 // Constant pool for this class.
188 ConstantPool* _constants;
189 // The InnerClasses attribute and EnclosingMethod attribute. The
190 // _inner_classes is an array of shorts. If the class has InnerClasses
191 // attribute, then the _inner_classes array begins with 4-tuples of shorts
192 // [inner_class_info_index, outer_class_info_index,
193 // inner_name_index, inner_class_access_flags] for the InnerClasses
194 // attribute. If the EnclosingMethod attribute exists, it occupies the
195 // last two shorts [class_index, method_index] of the array. If only
196 // the InnerClasses attribute exists, the _inner_classes array length is
197 // number_of_inner_classes * 4. If the class has both InnerClasses
198 // and EnclosingMethod attributes the _inner_classes array length is
199 // number_of_inner_classes * 4 + enclosing_method_attribute_size.
200 Array<jushort>* _inner_classes;
201
202 // Name of source file containing this klass, NULL if not specified.
203 Symbol* _source_file_name;
204 // the source debug extension for this klass, NULL if not specified.
205 // Specified as UTF-8 string without terminating zero byte in the classfile,
206 // it is stored in the instanceklass as a NULL-terminated UTF-8 string
207 char* _source_debug_extension;
208 // Generic signature, or null if none.
209 Symbol* _generic_signature;
210 // Array name derived from this class which needs unreferencing
211 // if this class is unloaded.
212 Symbol* _array_name;
213
214 // Number of heapOopSize words used by non-static fields in this klass
215 // (including inherited fields but after header_size()).
216 int _nonstatic_field_size;
217 int _static_field_size; // number words used by static fields (oop and non-oop) in this klass
218 u2 _static_oop_field_count;// number of static oop fields in this klass
219 u2 _java_fields_count; // The number of declared Java fields
220 int _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
221
222 // _is_marked_dependent can be set concurrently, thus cannot be part of the
223 // _misc_flags.
224 bool _is_marked_dependent; // used for marking during flushing and deoptimization
225
226 enum {
227 _misc_rewritten = 1 << 0, // methods rewritten.
228 _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
229 _misc_should_verify_class = 1 << 2, // allow caching of preverification
230 _misc_is_anonymous = 1 << 3, // has embedded _host_klass field
231 _misc_is_contended = 1 << 4, // marked with contended annotation
232 _misc_has_default_methods = 1 << 5 // class/superclass/implemented interfaces has default methods
233 };
234 u2 _misc_flags;
235 u2 _minor_version; // minor version number of class file
236 u2 _major_version; // major version number of class file
237 Thread* _init_thread; // Pointer to current thread doing initialization (to handle recusive initialization)
238 int _vtable_len; // length of Java vtable (in words)
239 int _itable_len; // length of Java itable (in words)
240 OopMapCache* volatile _oop_map_cache; // OopMapCache for all methods in the klass (allocated lazily)
241 MemberNameTable* _member_names; // Member names
242 JNIid* _jni_ids; // First JNI identifier for static fields in this class
243 jmethodID* _methods_jmethod_ids; // jmethodIDs corresponding to method_idnum, or NULL if none
244 int* _methods_cached_itable_indices; // itable_index cache for JNI invoke corresponding to methods idnum, or NULL
245 nmethodBucket* _dependencies; // list of dependent nmethods
246 nmethod* _osr_nmethods_head; // Head of list of on-stack replacement nmethods for this class
247 BreakpointInfo* _breakpoints; // bpt lists, managed by Method*
248 // Array of interesting part(s) of the previous version(s) of this
249 // InstanceKlass. See PreviousVersionWalker below.
250 GrowableArray<PreviousVersionNode *>* _previous_versions;
251 // JVMTI fields can be moved to their own structure - see 6315920
252 unsigned char * _cached_class_file_bytes; // JVMTI: cached class file, before retransformable agent modified it in CFLH
253 jint _cached_class_file_len; // JVMTI: length of above
254
255 volatile u2 _idnum_allocated_count; // JNI/JVMTI: increments with the addition of methods, old ids don't change
256
257 // Class states are defined as ClassState (see above).
258 // Place the _init_state here to utilize the unused 2-byte after
259 // _idnum_allocated_count.
260 u1 _init_state; // state of class
261 u1 _reference_type; // reference type
262
263 JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map; // JVMTI: used during heap iteration
264
265 NOT_PRODUCT(int _verify_count;) // to avoid redundant verifies
266
267 // Method array.
268 Array<Method*>* _methods;
269 // Interface (Klass*s) this class declares locally to implement.
270 Array<Klass*>* _local_interfaces;
271 // Interface (Klass*s) this class implements transitively.
272 Array<Klass*>* _transitive_interfaces;
273 // Int array containing the original order of method in the class file (for JVMTI).
274 Array<int>* _method_ordering;
275 // Instance and static variable information, starts with 6-tuples of shorts
276 // [access, name index, sig index, initval index, low_offset, high_offset]
277 // for all fields, followed by the generic signature data at the end of
278 // the array. Only fields with generic signature attributes have the generic
279 // signature data set in the array. The fields array looks like following:
280 //
281 // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
282 // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
283 // ...
284 // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
285 // [generic signature index]
286 // [generic signature index]
287 // ...
288 Array<u2>* _fields;
289
290 // embedded Java vtable follows here
291 // embedded Java itables follows here
292 // embedded static fields follows here
293 // embedded nonstatic oop-map blocks follows here
294 // embedded implementor of this interface follows here
295 // The embedded implementor only exists if the current klass is an
296 // iterface. The possible values of the implementor fall into following
297 // three cases:
298 // NULL: no implementor.
299 // A Klass* that's not itself: one implementor.
300 // Itsef: more than one implementors.
301 // embedded host klass follows here
302 // The embedded host klass only exists in an anonymous class for
303 // dynamic language support (JSR 292 enabled). The host class grants
304 // its access privileges to this class also. The host class is either
305 // named, or a previously loaded anonymous class. A non-anonymous class
306 // or an anonymous class loaded through normal classloading does not
307 // have this embedded field.
308 //
309
310 friend class SystemDictionary;
311
312 public:
313 bool has_nonstatic_fields() const {
314 return (_misc_flags & _misc_has_nonstatic_fields) != 0;
315 }
316 void set_has_nonstatic_fields(bool b) {
317 if (b) {
318 _misc_flags |= _misc_has_nonstatic_fields;
319 } else {
320 _misc_flags &= ~_misc_has_nonstatic_fields;
321 }
322 }
323
324 // field sizes
325 int nonstatic_field_size() const { return _nonstatic_field_size; }
326 void set_nonstatic_field_size(int size) { _nonstatic_field_size = size; }
327
328 int static_field_size() const { return _static_field_size; }
329 void set_static_field_size(int size) { _static_field_size = size; }
330
331 int static_oop_field_count() const { return (int)_static_oop_field_count; }
332 void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
333
334 // Java vtable
335 int vtable_length() const { return _vtable_len; }
336 void set_vtable_length(int len) { _vtable_len = len; }
337
338 // Java itable
339 int itable_length() const { return _itable_len; }
340 void set_itable_length(int len) { _itable_len = len; }
341
342 // array klasses
343 Klass* array_klasses() const { return _array_klasses; }
344 void set_array_klasses(Klass* k) { _array_klasses = k; }
345
346 // methods
347 Array<Method*>* methods() const { return _methods; }
348 void set_methods(Array<Method*>* a) { _methods = a; }
349 Method* method_with_idnum(int idnum);
350
351 // method ordering
352 Array<int>* method_ordering() const { return _method_ordering; }
353 void set_method_ordering(Array<int>* m) { _method_ordering = m; }
354 void copy_method_ordering(intArray* m, TRAPS);
355
356 // interfaces
357 Array<Klass*>* local_interfaces() const { return _local_interfaces; }
358 void set_local_interfaces(Array<Klass*>* a) {
359 guarantee(_local_interfaces == NULL || a == NULL, "Just checking");
360 _local_interfaces = a; }
361
362 Array<Klass*>* transitive_interfaces() const { return _transitive_interfaces; }
363 void set_transitive_interfaces(Array<Klass*>* a) {
364 guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");
365 _transitive_interfaces = a;
366 }
367
368 private:
369 friend class fieldDescriptor;
370 FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
371
372 public:
373 int field_offset (int index) const { return field(index)->offset(); }
374 int field_access_flags(int index) const { return field(index)->access_flags(); }
375 Symbol* field_name (int index) const { return field(index)->name(constants()); }
376 Symbol* field_signature (int index) const { return field(index)->signature(constants()); }
377
378 // Number of Java declared fields
379 int java_fields_count() const { return (int)_java_fields_count; }
380
381 Array<u2>* fields() const { return _fields; }
382 void set_fields(Array<u2>* f, u2 java_fields_count) {
383 guarantee(_fields == NULL || f == NULL, "Just checking");
384 _fields = f;
385 _java_fields_count = java_fields_count;
386 }
387
388 // inner classes
389 Array<u2>* inner_classes() const { return _inner_classes; }
390 void set_inner_classes(Array<u2>* f) { _inner_classes = f; }
391
392 enum InnerClassAttributeOffset {
393 // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
394 inner_class_inner_class_info_offset = 0,
395 inner_class_outer_class_info_offset = 1,
396 inner_class_inner_name_offset = 2,
397 inner_class_access_flags_offset = 3,
398 inner_class_next_offset = 4
399 };
400
401 enum EnclosingMethodAttributeOffset {
402 enclosing_method_class_index_offset = 0,
403 enclosing_method_method_index_offset = 1,
404 enclosing_method_attribute_size = 2
405 };
406
407 // method override check
408 bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
409
410 // package
411 bool is_same_class_package(Klass* class2);
412 bool is_same_class_package(oop classloader2, Symbol* classname2);
413 static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
414
415 // find an enclosing class (defined where original code was, in jvm.cpp!)
416 Klass* compute_enclosing_class(bool* inner_is_member, TRAPS) {
417 instanceKlassHandle self(THREAD, this);
418 return compute_enclosing_class_impl(self, inner_is_member, THREAD);
419 }
420 static Klass* compute_enclosing_class_impl(instanceKlassHandle self,
421 bool* inner_is_member, TRAPS);
422
423 // tell if two classes have the same enclosing class (at package level)
424 bool is_same_package_member(Klass* class2, TRAPS) {
425 instanceKlassHandle self(THREAD, this);
426 return is_same_package_member_impl(self, class2, THREAD);
427 }
428 static bool is_same_package_member_impl(instanceKlassHandle self,
429 Klass* class2, TRAPS);
430
431 // initialization state
432 bool is_loaded() const { return _init_state >= loaded; }
433 bool is_linked() const { return _init_state >= linked; }
434 bool is_initialized() const { return _init_state == fully_initialized; }
435 bool is_not_initialized() const { return _init_state < being_initialized; }
436 bool is_being_initialized() const { return _init_state == being_initialized; }
437 bool is_in_error_state() const { return _init_state == initialization_error; }
438 bool is_reentrant_initialization(Thread *thread) { return thread == _init_thread; }
439 ClassState init_state() { return (ClassState)_init_state; }
440 bool is_rewritten() const { return (_misc_flags & _misc_rewritten) != 0; }
441
442 // defineClass specified verification
443 bool should_verify_class() const {
444 return (_misc_flags & _misc_should_verify_class) != 0;
445 }
446 void set_should_verify_class(bool value) {
447 if (value) {
448 _misc_flags |= _misc_should_verify_class;
449 } else {
450 _misc_flags &= ~_misc_should_verify_class;
451 }
452 }
453
454 // marking
455 bool is_marked_dependent() const { return _is_marked_dependent; }
456 void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
457
458 // initialization (virtuals from Klass)
459 bool should_be_initialized() const; // means that initialize should be called
460 void initialize(TRAPS);
461 void link_class(TRAPS);
462 bool link_class_or_fail(TRAPS); // returns false on failure
463 void unlink_class();
464 void rewrite_class(TRAPS);
465 void link_methods(TRAPS);
466 Method* class_initializer();
467
468 // set the class to initialized if no static initializer is present
469 void eager_initialize(Thread *thread);
470
471 // reference type
472 ReferenceType reference_type() const { return (ReferenceType)_reference_type; }
473 void set_reference_type(ReferenceType t) {
474 assert(t == (u1)t, "overflow");
475 _reference_type = (u1)t;
476 }
477
478 static ByteSize reference_type_offset() { return in_ByteSize(offset_of(InstanceKlass, _reference_type)); }
479
480 // find local field, returns true if found
481 bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
482 // find field in direct superinterfaces, returns the interface in which the field is defined
483 Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
484 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
485 Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
486 // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
487 Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
488
489 // find a non-static or static field given its offset within the class.
490 bool contains_field_offset(int offset) {
491 return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
492 }
493
494 bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
495 bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
496
497 // find a local method (returns NULL if not found)
498 Method* find_method(Symbol* name, Symbol* signature) const;
499 static Method* find_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
500
501 // lookup operation (returns NULL if not found)
502 Method* uncached_lookup_method(Symbol* name, Symbol* signature) const;
503
504 // lookup a method in all the interfaces that this class implements
505 // (returns NULL if not found)
506 Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature) const;
507
508 // Find method indices by name. If a method with the specified name is
509 // found the index to the first method is returned, and 'end' is filled in
510 // with the index of first non-name-matching method. If no method is found
511 // -1 is returned.
512 int find_method_by_name(Symbol* name, int* end);
513 static int find_method_by_name(Array<Method*>* methods, Symbol* name, int* end);
514
515 // constant pool
516 ConstantPool* constants() const { return _constants; }
517 void set_constants(ConstantPool* c) { _constants = c; }
518
519 // protection domain
520 oop protection_domain() const;
521
522 // signers
523 objArrayOop signers() const;
524
525 // host class
526 Klass* host_klass() const {
527 Klass** hk = (Klass**)adr_host_klass();
528 if (hk == NULL) {
529 return NULL;
530 } else {
531 return *hk;
532 }
533 }
534 void set_host_klass(Klass* host) {
535 assert(is_anonymous(), "not anonymous");
536 Klass** addr = (Klass**)adr_host_klass();
537 assert(addr != NULL, "no reversed space");
538 if (addr != NULL) {
539 *addr = host;
540 }
541 }
542 bool is_anonymous() const {
543 return (_misc_flags & _misc_is_anonymous) != 0;
544 }
545 void set_is_anonymous(bool value) {
546 if (value) {
547 _misc_flags |= _misc_is_anonymous;
548 } else {
549 _misc_flags &= ~_misc_is_anonymous;
550 }
551 }
552
553 // Oop that keeps the metadata for this class from being unloaded
554 // in places where the metadata is stored in other places, like nmethods
555 oop klass_holder() const {
556 return is_anonymous() ? java_mirror() : class_loader();
557 }
558
559 bool is_contended() const {
560 return (_misc_flags & _misc_is_contended) != 0;
561 }
562 void set_is_contended(bool value) {
563 if (value) {
564 _misc_flags |= _misc_is_contended;
565 } else {
566 _misc_flags &= ~_misc_is_contended;
567 }
568 }
569
570 // source file name
571 Symbol* source_file_name() const { return _source_file_name; }
572 void set_source_file_name(Symbol* n);
573
574 // minor and major version numbers of class file
575 u2 minor_version() const { return _minor_version; }
576 void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
577 u2 major_version() const { return _major_version; }
578 void set_major_version(u2 major_version) { _major_version = major_version; }
579
580 // source debug extension
581 char* source_debug_extension() const { return _source_debug_extension; }
582 void set_source_debug_extension(char* array, int length);
583
584 // symbol unloading support (refcount already added)
585 Symbol* array_name() { return _array_name; }
586 void set_array_name(Symbol* name) { assert(_array_name == NULL || name == NULL, "name already created"); _array_name = name; }
587
588 // nonstatic oop-map blocks
589 static int nonstatic_oop_map_size(unsigned int oop_map_count) {
590 return oop_map_count * OopMapBlock::size_in_words();
591 }
592 unsigned int nonstatic_oop_map_count() const {
593 return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
594 }
595 int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
596 void set_nonstatic_oop_map_size(int words) {
597 _nonstatic_oop_map_size = words;
598 }
599
600 // RedefineClasses() support for previous versions:
601 void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
602 int emcp_method_count);
603 // If the _previous_versions array is non-NULL, then this klass
604 // has been redefined at least once even if we aren't currently
605 // tracking a previous version.
606 bool has_been_redefined() const { return _previous_versions != NULL; }
607 bool has_previous_version() const;
608 void init_previous_versions() {
609 _previous_versions = NULL;
610 }
611 GrowableArray<PreviousVersionNode *>* previous_versions() const {
612 return _previous_versions;
613 }
614
615 static void purge_previous_versions(InstanceKlass* ik);
616
617 // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
618 void set_cached_class_file(unsigned char *class_file_bytes,
619 jint class_file_len) { _cached_class_file_len = class_file_len;
620 _cached_class_file_bytes = class_file_bytes; }
621 jint get_cached_class_file_len() { return _cached_class_file_len; }
622 unsigned char * get_cached_class_file_bytes() { return _cached_class_file_bytes; }
623
624 // JVMTI: Support for caching of field indices, types, and offsets
625 void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
626 _jvmti_cached_class_field_map = descriptor;
627 }
628 JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
629 return _jvmti_cached_class_field_map;
630 }
631
632 bool has_default_methods() const {
633 return (_misc_flags & _misc_has_default_methods) != 0;
634 }
635 void set_has_default_methods(bool b) {
636 if (b) {
637 _misc_flags |= _misc_has_default_methods;
638 } else {
639 _misc_flags &= ~_misc_has_default_methods;
640 }
641 }
642
643 // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
644 inline u2 next_method_idnum();
645 void set_initial_method_idnum(u2 value) { _idnum_allocated_count = value; }
646
647 // generics support
648 Symbol* generic_signature() const { return _generic_signature; }
649 void set_generic_signature(Symbol* sig) { _generic_signature = sig; }
650
651 u2 enclosing_method_data(int offset);
652 u2 enclosing_method_class_index() {
653 return enclosing_method_data(enclosing_method_class_index_offset);
654 }
655 u2 enclosing_method_method_index() {
656 return enclosing_method_data(enclosing_method_method_index_offset);
657 }
658 void set_enclosing_method_indices(u2 class_index,
659 u2 method_index);
660
661 // jmethodID support
662 static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
663 methodHandle method_h);
664 static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
665 size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
666 jmethodID* to_dealloc_id_p,
667 jmethodID** to_dealloc_jmeths_p);
668 static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
669 size_t *length_p, jmethodID* id_p);
670 jmethodID jmethod_id_or_null(Method* method);
671
672 // cached itable index support
673 void set_cached_itable_index(size_t idnum, int index);
674 int cached_itable_index(size_t idnum);
675
676 // annotations support
677 Annotations* annotations() const { return _annotations; }
678 void set_annotations(Annotations* anno) { _annotations = anno; }
679
680 AnnotationArray* class_annotations() const {
681 return (_annotations != NULL) ? _annotations->class_annotations() : NULL;
682 }
683 Array<AnnotationArray*>* fields_annotations() const {
684 return (_annotations != NULL) ? _annotations->fields_annotations() : NULL;
685 }
686 AnnotationArray* class_type_annotations() const {
687 return (_annotations != NULL) ? _annotations->class_type_annotations() : NULL;
688 }
689 Array<AnnotationArray*>* fields_type_annotations() const {
690 return (_annotations != NULL) ? _annotations->fields_type_annotations() : NULL;
691 }
692 // allocation
693 instanceOop allocate_instance(TRAPS);
694
695 // additional member function to return a handle
696 instanceHandle allocate_instance_handle(TRAPS) { return instanceHandle(THREAD, allocate_instance(THREAD)); }
697
698 objArrayOop allocate_objArray(int n, int length, TRAPS);
699 // Helper function
700 static instanceOop register_finalizer(instanceOop i, TRAPS);
701
702 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
703 // if not, throw either an Error or an Exception.
704 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
705
706 // initialization
707 void call_class_initializer(TRAPS);
708 void set_initialization_state_and_notify(ClassState state, TRAPS);
709
710 // OopMapCache support
711 OopMapCache* oop_map_cache() { return _oop_map_cache; }
712 void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
713 void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
714
715 // JNI identifier support (for static fields - for jni performance)
716 JNIid* jni_ids() { return _jni_ids; }
717 void set_jni_ids(JNIid* ids) { _jni_ids = ids; }
718 JNIid* jni_id_for(int offset);
719
720 // maintenance of deoptimization dependencies
721 int mark_dependent_nmethods(DepChange& changes);
722 void add_dependent_nmethod(nmethod* nm);
723 void remove_dependent_nmethod(nmethod* nm);
724
725 // On-stack replacement support
726 nmethod* osr_nmethods_head() const { return _osr_nmethods_head; };
727 void set_osr_nmethods_head(nmethod* h) { _osr_nmethods_head = h; };
728 void add_osr_nmethod(nmethod* n);
729 void remove_osr_nmethod(nmethod* n);
730 nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
731
732 // Breakpoint support (see methods on Method* for details)
733 BreakpointInfo* breakpoints() const { return _breakpoints; };
734 void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
735
736 // support for stub routines
737 static ByteSize init_state_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_state)); }
738 TRACE_DEFINE_OFFSET;
739 static ByteSize init_thread_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_thread)); }
740
741 // subclass/subinterface checks
742 bool implements_interface(Klass* k) const;
743
744 // Access to the implementor of an interface.
745 Klass* implementor() const
746 {
747 Klass** k = adr_implementor();
748 if (k == NULL) {
749 return NULL;
750 } else {
751 return *k;
752 }
753 }
754
755 void set_implementor(Klass* k) {
756 assert(is_interface(), "not interface");
757 Klass** addr = adr_implementor();
758 assert(addr != NULL, "null addr");
759 if (addr != NULL) {
760 *addr = k;
761 }
762 }
763
764 int nof_implementors() const {
765 Klass* k = implementor();
766 if (k == NULL) {
767 return 0;
768 } else if (k != this) {
769 return 1;
770 } else {
771 return 2;
772 }
773 }
774
775 void add_implementor(Klass* k); // k is a new class that implements this interface
776 void init_implementor(); // initialize
777
778 // link this class into the implementors list of every interface it implements
779 void process_interfaces(Thread *thread);
780
781 // virtual operations from Klass
782 bool is_leaf_class() const { return _subklass == NULL; }
783 GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
784 bool compute_is_subtype_of(Klass* k);
785 bool can_be_primary_super_slow() const;
786 int oop_size(oop obj) const { return size_helper(); }
787 bool oop_is_instance_slow() const { return true; }
788
789 // Iterators
790 void do_local_static_fields(FieldClosure* cl);
791 void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
792 void do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS);
793
794 void methods_do(void f(Method* method));
795 void array_klasses_do(void f(Klass* k));
796 void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
797 void with_array_klasses_do(void f(Klass* k));
798 bool super_types_do(SuperTypeClosure* blk);
799
800 // Casting from Klass*
801 static InstanceKlass* cast(Klass* k) {
802 assert(k->is_klass(), "must be");
803 assert(k->oop_is_instance(), "cast to InstanceKlass");
804 return (InstanceKlass*) k;
805 }
806
807 InstanceKlass* java_super() const {
808 return (super() == NULL) ? NULL : cast(super());
809 }
810
811 // Sizing (in words)
812 static int header_size() { return align_object_offset(sizeof(InstanceKlass)/HeapWordSize); }
813
814 static int size(int vtable_length, int itable_length,
815 int nonstatic_oop_map_size,
816 bool is_interface, bool is_anonymous) {
817 return align_object_size(header_size() +
818 align_object_offset(vtable_length) +
819 align_object_offset(itable_length) +
820 ((is_interface || is_anonymous) ?
821 align_object_offset(nonstatic_oop_map_size) :
822 nonstatic_oop_map_size) +
823 (is_interface ? (int)sizeof(Klass*)/HeapWordSize : 0) +
824 (is_anonymous ? (int)sizeof(Klass*)/HeapWordSize : 0));
825 }
826 int size() const { return size(vtable_length(),
827 itable_length(),
828 nonstatic_oop_map_size(),
829 is_interface(),
830 is_anonymous());
831 }
832 #if INCLUDE_SERVICES
833 virtual void collect_statistics(KlassSizeStats *sz) const;
834 #endif
835
836 static int vtable_start_offset() { return header_size(); }
837 static int vtable_length_offset() { return offset_of(InstanceKlass, _vtable_len) / HeapWordSize; }
838
839 intptr_t* start_of_vtable() const { return ((intptr_t*)this) + vtable_start_offset(); }
840 intptr_t* start_of_itable() const { return start_of_vtable() + align_object_offset(vtable_length()); }
841 int itable_offset_in_words() const { return start_of_itable() - (intptr_t*)this; }
842
843 intptr_t* end_of_itable() const { return start_of_itable() + itable_length(); }
844
845 address static_field_addr(int offset);
846
847 OopMapBlock* start_of_nonstatic_oop_maps() const {
848 return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
849 }
850
851 Klass** end_of_nonstatic_oop_maps() const {
852 return (Klass**)(start_of_nonstatic_oop_maps() +
853 nonstatic_oop_map_count());
854 }
855
856 Klass** adr_implementor() const {
857 if (is_interface()) {
858 return (Klass**)end_of_nonstatic_oop_maps();
859 } else {
860 return NULL;
861 }
862 };
863
864 Klass** adr_host_klass() const {
865 if (is_anonymous()) {
866 Klass** adr_impl = adr_implementor();
867 if (adr_impl != NULL) {
868 return adr_impl + 1;
869 } else {
870 return end_of_nonstatic_oop_maps();
871 }
872 } else {
873 return NULL;
874 }
875 }
876
877 // Allocation profiling support
878 juint alloc_size() const { return _alloc_count * size_helper(); }
879 void set_alloc_size(juint n) {}
880
881 // Use this to return the size of an instance in heap words:
882 int size_helper() const {
883 return layout_helper_to_size_helper(layout_helper());
884 }
885
886 // This bit is initialized in classFileParser.cpp.
887 // It is false under any of the following conditions:
888 // - the class is abstract (including any interface)
889 // - the class has a finalizer (if !RegisterFinalizersAtInit)
890 // - the class size is larger than FastAllocateSizeLimit
891 // - the class is java/lang/Class, which cannot be allocated directly
892 bool can_be_fastpath_allocated() const {
893 return !layout_helper_needs_slow_path(layout_helper());
894 }
895
896 // Java vtable/itable
897 klassVtable* vtable() const; // return new klassVtable wrapper
898 inline Method* method_at_vtable(int index);
899 klassItable* itable() const; // return new klassItable wrapper
900 Method* method_at_itable(Klass* holder, int index, TRAPS);
901
902 // Garbage collection
903 void oop_follow_contents(oop obj);
904 int oop_adjust_pointers(oop obj);
905
906 void clean_implementors_list(BoolObjectClosure* is_alive);
907 void clean_method_data(BoolObjectClosure* is_alive);
908
909 // Explicit metaspace deallocation of fields
910 // For RedefineClasses and class file parsing errors, we need to deallocate
911 // instanceKlasses and the metadata they point to.
912 void deallocate_contents(ClassLoaderData* loader_data);
913 static void deallocate_methods(ClassLoaderData* loader_data,
914 Array<Method*>* methods);
915 void static deallocate_interfaces(ClassLoaderData* loader_data,
916 Klass* super_klass,
917 Array<Klass*>* local_interfaces,
918 Array<Klass*>* transitive_interfaces);
919
920 // The constant pool is on stack if any of the methods are executing or
921 // referenced by handles.
922 bool on_stack() const { return _constants->on_stack(); }
923
924 // callbacks for actions during class unloading
925 static void notify_unload_class(InstanceKlass* ik);
926 static void release_C_heap_structures(InstanceKlass* ik);
927
928 // Parallel Scavenge and Parallel Old
929 PARALLEL_GC_DECLS
930
931 // Naming
932 const char* signature_name() const;
933
934 // Iterators
935 int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) {
936 return oop_oop_iterate_v(obj, blk);
937 }
938
939 int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) {
940 return oop_oop_iterate_v_m(obj, blk, mr);
941 }
942
943 #define InstanceKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
944 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \
945 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, \
946 MemRegion mr);
947
948 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DECL)
949 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DECL)
950
951 #if INCLUDE_ALL_GCS
952 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
953 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
954
955 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
956 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
957 #endif // INCLUDE_ALL_GCS
958
959 u2 idnum_allocated_count() const { return _idnum_allocated_count; }
960
961 private:
962 // initialization state
963 #ifdef ASSERT
964 void set_init_state(ClassState state);
965 #else
966 void set_init_state(ClassState state) { _init_state = (u1)state; }
967 #endif
968 void set_rewritten() { _misc_flags |= _misc_rewritten; }
969 void set_init_thread(Thread *thread) { _init_thread = thread; }
970
971 // The RedefineClasses() API can cause new method idnums to be needed
972 // which will cause the caches to grow. Safety requires different
973 // cache management logic if the caches can grow instead of just
974 // going from NULL to non-NULL.
975 bool idnum_can_increment() const { return has_been_redefined(); }
976 jmethodID* methods_jmethod_ids_acquire() const
977 { return (jmethodID*)OrderAccess::load_ptr_acquire(&_methods_jmethod_ids); }
978 void release_set_methods_jmethod_ids(jmethodID* jmeths)
979 { OrderAccess::release_store_ptr(&_methods_jmethod_ids, jmeths); }
980
981 int* methods_cached_itable_indices_acquire() const
982 { return (int*)OrderAccess::load_ptr_acquire(&_methods_cached_itable_indices); }
983 void release_set_methods_cached_itable_indices(int* indices)
984 { OrderAccess::release_store_ptr(&_methods_cached_itable_indices, indices); }
985
986 // Lock during initialization
987 public:
988 // Lock for (1) initialization; (2) access to the ConstantPool of this class.
989 // Must be one per class and it has to be a VM internal object so java code
990 // cannot lock it (like the mirror).
991 // It has to be an object not a Mutex because it's held through java calls.
992 volatile oop init_lock() const;
993 private:
994
995 // Static methods that are used to implement member methods where an exposed this pointer
996 // is needed due to possible GCs
997 static bool link_class_impl (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
998 static bool verify_code (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
999 static void initialize_impl (instanceKlassHandle this_oop, TRAPS);
1000 static void eager_initialize_impl (instanceKlassHandle this_oop);
1001 static void set_initialization_state_and_notify_impl (instanceKlassHandle this_oop, ClassState state, TRAPS);
1002 static void call_class_initializer_impl (instanceKlassHandle this_oop, TRAPS);
1003 static Klass* array_klass_impl (instanceKlassHandle this_oop, bool or_null, int n, TRAPS);
1004 static void do_local_static_fields_impl (instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS);
1005 /* jni_id_for_impl for jfieldID only */
1006 static JNIid* jni_id_for_impl (instanceKlassHandle this_oop, int offset);
1007
1008 // Returns the array class for the n'th dimension
1009 Klass* array_klass_impl(bool or_null, int n, TRAPS);
1010
1011 // Returns the array class with this class as element type
1012 Klass* array_klass_impl(bool or_null, TRAPS);
1013
1014 // Free CHeap allocated fields.
1015 void release_C_heap_structures();
1016 public:
1017 // CDS support - remove and restore oops from metadata. Oops are not shared.
1018 virtual void remove_unshareable_info();
1019 virtual void restore_unshareable_info(TRAPS);
1020
1021 // jvm support
1022 jint compute_modifier_flags(TRAPS) const;
1023
1024 // JSR-292 support
1025 MemberNameTable* member_names() { return _member_names; }
1026 void set_member_names(MemberNameTable* member_names) { _member_names = member_names; }
1027 void add_member_name(int index, Handle member_name);
1028 oop get_member_name(int index);
1029
1030 public:
1031 // JVMTI support
1032 jint jvmti_class_status() const;
1033
1034 public:
1035 // Printing
1036 #ifndef PRODUCT
1037 void print_on(outputStream* st) const;
1038 #endif
1039 void print_value_on(outputStream* st) const;
1040
1041 void oop_print_value_on(oop obj, outputStream* st);
1042
1043 #ifndef PRODUCT
1044 void oop_print_on (oop obj, outputStream* st);
1045
1046 void print_dependent_nmethods(bool verbose = false);
1047 bool is_dependent_nmethod(nmethod* nm);
1048 #endif
1049
1050 const char* internal_name() const;
1051
1052 // Verification
1053 void verify_on(outputStream* st);
1054
1055 void oop_verify_on(oop obj, outputStream* st);
1056 };
1057
1058 inline Method* InstanceKlass::method_at_vtable(int index) {
1059 #ifndef PRODUCT
1060 assert(index >= 0, "valid vtable index");
1061 if (DebugVtables) {
1062 verify_vtable_index(index);
1063 }
1064 #endif
1065 vtableEntry* ve = (vtableEntry*)start_of_vtable();
1066 return ve[index].method();
1067 }
1068
1069 // for adding methods
1070 // UNSET_IDNUM return means no more ids available
1071 inline u2 InstanceKlass::next_method_idnum() {
1072 if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1073 return ConstMethod::UNSET_IDNUM; // no more ids available
1074 } else {
1075 return _idnum_allocated_count++;
1076 }
1077 }
1078
1079
1080 /* JNIid class for jfieldIDs only */
1081 class JNIid: public CHeapObj<mtClass> {
1082 friend class VMStructs;
1083 private:
1084 Klass* _holder;
1085 JNIid* _next;
1086 int _offset;
1087 #ifdef ASSERT
1088 bool _is_static_field_id;
1089 #endif
1090
1091 public:
1092 // Accessors
1093 Klass* holder() const { return _holder; }
1094 int offset() const { return _offset; }
1095 JNIid* next() { return _next; }
1096 // Constructor
1097 JNIid(Klass* holder, int offset, JNIid* next);
1098 // Identifier lookup
1099 JNIid* find(int offset);
1100
1101 bool find_local_field(fieldDescriptor* fd) {
1102 return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1103 }
1104
1105 static void deallocate(JNIid* id);
1106 // Debugging
1107 #ifdef ASSERT
1108 bool is_static_field_id() const { return _is_static_field_id; }
1109 void set_is_static_field_id() { _is_static_field_id = true; }
1110 #endif
1111 void verify(Klass* holder);
1112 };
1113
1114
1115 // If breakpoints are more numerous than just JVMTI breakpoints,
1116 // consider compressing this data structure.
1117 // It is currently a simple linked list defined in method.hpp.
1118
1119 class BreakpointInfo;
1120
1121
1122 // A collection point for interesting information about the previous
1123 // version(s) of an InstanceKlass. This class uses weak references to
1124 // the information so that the information may be collected as needed
1125 // by the system. If the information is shared, then a regular
1126 // reference must be used because a weak reference would be seen as
1127 // collectible. A GrowableArray of PreviousVersionNodes is attached
1128 // to the InstanceKlass as needed. See PreviousVersionWalker below.
1129 class PreviousVersionNode : public CHeapObj<mtClass> {
1130 private:
1131 // A shared ConstantPool is never collected so we'll always have
1132 // a reference to it so we can update items in the cache. We'll
1133 // have a weak reference to a non-shared ConstantPool until all
1134 // of the methods (EMCP or obsolete) have been collected; the
1135 // non-shared ConstantPool becomes collectible at that point.
1136 ConstantPool* _prev_constant_pool; // regular or weak reference
1137 bool _prev_cp_is_weak; // true if not a shared ConstantPool
1138
1139 // If the previous version of the InstanceKlass doesn't have any
1140 // EMCP methods, then _prev_EMCP_methods will be NULL. If all the
1141 // EMCP methods have been collected, then _prev_EMCP_methods can
1142 // have a length of zero.
1143 GrowableArray<Method*>* _prev_EMCP_methods;
1144
1145 public:
1146 PreviousVersionNode(ConstantPool* prev_constant_pool, bool prev_cp_is_weak,
1147 GrowableArray<Method*>* prev_EMCP_methods);
1148 ~PreviousVersionNode();
1149 ConstantPool* prev_constant_pool() const {
1150 return _prev_constant_pool;
1151 }
1152 GrowableArray<Method*>* prev_EMCP_methods() const {
1153 return _prev_EMCP_methods;
1154 }
1155 };
1156
1157
1158 // A Handle-ized version of PreviousVersionNode.
1159 class PreviousVersionInfo : public ResourceObj {
1160 private:
1161 constantPoolHandle _prev_constant_pool_handle;
1162 // If the previous version of the InstanceKlass doesn't have any
1163 // EMCP methods, then _prev_EMCP_methods will be NULL. Since the
1164 // methods cannot be collected while we hold a handle,
1165 // _prev_EMCP_methods should never have a length of zero.
1166 GrowableArray<methodHandle>* _prev_EMCP_method_handles;
1167
1168 public:
1169 PreviousVersionInfo(PreviousVersionNode *pv_node);
1170 ~PreviousVersionInfo();
1171 constantPoolHandle prev_constant_pool_handle() const {
1172 return _prev_constant_pool_handle;
1173 }
1174 GrowableArray<methodHandle>* prev_EMCP_method_handles() const {
1175 return _prev_EMCP_method_handles;
1176 }
1177 };
1178
1179
1180 // Helper object for walking previous versions. This helper cleans up
1181 // the Handles that it allocates when the helper object is destroyed.
1182 // The PreviousVersionInfo object returned by next_previous_version()
1183 // is only valid until a subsequent call to next_previous_version() or
1184 // the helper object is destroyed.
1185 class PreviousVersionWalker : public StackObj {
1186 private:
1187 GrowableArray<PreviousVersionNode *>* _previous_versions;
1188 int _current_index;
1189 // Fields for cleaning up when we are done walking the previous versions:
1190 // A HandleMark for the PreviousVersionInfo handles:
1191 HandleMark _hm;
1192
1193 // It would be nice to have a ResourceMark field in this helper also,
1194 // but the ResourceMark code says to be careful to delete handles held
1195 // in GrowableArrays _before_ deleting the GrowableArray. Since we
1196 // can't guarantee the order in which the fields are destroyed, we
1197 // have to let the creator of the PreviousVersionWalker object do
1198 // the right thing. Also, adding a ResourceMark here causes an
1199 // include loop.
1200
1201 // A pointer to the current info object so we can handle the deletes.
1202 PreviousVersionInfo * _current_p;
1203
1204 public:
1205 PreviousVersionWalker(InstanceKlass *ik);
1206 ~PreviousVersionWalker();
1207
1208 // Return the interesting information for the next previous version
1209 // of the klass. Returns NULL if there are no more previous versions.
1210 PreviousVersionInfo* next_previous_version();
1211 };
1212
1213
1214 //
1215 // nmethodBucket is used to record dependent nmethods for
1216 // deoptimization. nmethod dependencies are actually <klass, method>
1217 // pairs but we really only care about the klass part for purposes of
1218 // finding nmethods which might need to be deoptimized. Instead of
1219 // recording the method, a count of how many times a particular nmethod
1220 // was recorded is kept. This ensures that any recording errors are
1221 // noticed since an nmethod should be removed as many times are it's
1222 // added.
1223 //
1224 class nmethodBucket: public CHeapObj<mtClass> {
1225 friend class VMStructs;
1226 private:
1227 nmethod* _nmethod;
1228 int _count;
1229 nmethodBucket* _next;
1230
1231 public:
1232 nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
1233 _nmethod = nmethod;
1234 _next = next;
1235 _count = 1;
1236 }
1237 int count() { return _count; }
1238 int increment() { _count += 1; return _count; }
1239 int decrement() { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
1240 nmethodBucket* next() { return _next; }
1241 void set_next(nmethodBucket* b) { _next = b; }
1242 nmethod* get_nmethod() { return _nmethod; }
1243 };
1244
1245 // An iterator that's used to access the inner classes indices in the
1246 // InstanceKlass::_inner_classes array.
1247 class InnerClassesIterator : public StackObj {
1248 private:
1249 Array<jushort>* _inner_classes;
1250 int _length;
1251 int _idx;
1252 public:
1253
1254 InnerClassesIterator(instanceKlassHandle k) {
1255 _inner_classes = k->inner_classes();
1256 if (k->inner_classes() != NULL) {
1257 _length = _inner_classes->length();
1258 // The inner class array's length should be the multiple of
1259 // inner_class_next_offset if it only contains the InnerClasses
1260 // attribute data, or it should be
1261 // n*inner_class_next_offset+enclosing_method_attribute_size
1262 // if it also contains the EnclosingMethod data.
1263 assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1264 _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1265 "just checking");
1266 // Remove the enclosing_method portion if exists.
1267 if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1268 _length -= InstanceKlass::enclosing_method_attribute_size;
1269 }
1270 } else {
1271 _length = 0;
1272 }
1273 _idx = 0;
1274 }
1275
1276 int length() const {
1277 return _length;
1278 }
1279
1280 void next() {
1281 _idx += InstanceKlass::inner_class_next_offset;
1282 }
1283
1284 bool done() const {
1285 return (_idx >= _length);
1286 }
1287
1288 u2 inner_class_info_index() const {
1289 return _inner_classes->at(
1290 _idx + InstanceKlass::inner_class_inner_class_info_offset);
1291 }
1292
1293 void set_inner_class_info_index(u2 index) {
1294 _inner_classes->at_put(
1295 _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1296 }
1297
1298 u2 outer_class_info_index() const {
1299 return _inner_classes->at(
1300 _idx + InstanceKlass::inner_class_outer_class_info_offset);
1301 }
1302
1303 void set_outer_class_info_index(u2 index) {
1304 _inner_classes->at_put(
1305 _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1306 }
1307
1308 u2 inner_name_index() const {
1309 return _inner_classes->at(
1310 _idx + InstanceKlass::inner_class_inner_name_offset);
1311 }
1312
1313 void set_inner_name_index(u2 index) {
1314 _inner_classes->at_put(
1315 _idx + InstanceKlass::inner_class_inner_name_offset, index);
1316 }
1317
1318 u2 inner_access_flags() const {
1319 return _inner_classes->at(
1320 _idx + InstanceKlass::inner_class_access_flags_offset);
1321 }
1322 };
1323
1324 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP