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 // [source file name ]
62 // [inner classes ]
63 // [static field size ]
64 // [nonstatic field size ]
65 // [static oop fields size ]
66 // [nonstatic oop maps size ]
67 // [has finalize method ]
68 // [deoptimization mark bit ]
69 // [initialization state ]
70 // [initializing thread ]
71 // [Java vtable length ]
72 // [oop map cache (stack maps) ]
73 // [EMBEDDED Java vtable ] size in words = vtable_len
74 // [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
75 // The embedded nonstatic oop-map blocks are short pairs (offset, length)
76 // indicating where oops are located in instances of this klass.
77 // [EMBEDDED implementor of the interface] only exist for interface
78 // [EMBEDDED host klass ] only exist for an anonymous class (JSR 292 enabled)
79
80
81 // forward declaration for class -- see below for definition
82 class SuperTypeClosure;
83 class JNIid;
84 class jniIdMapBase;
85 class BreakpointInfo;
86 class fieldDescriptor;
87 class DepChange;
88 class nmethodBucket;
89 class PreviousVersionNode;
90 class JvmtiCachedClassFieldMap;
91 class MemberNameTable;
92
93 // This is used in iterators below.
94 class FieldClosure: public StackObj {
95 public:
96 virtual void do_field(fieldDescriptor* fd) = 0;
97 };
98
99 #ifndef PRODUCT
100 // Print fields.
101 // If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.
102 class FieldPrinter: public FieldClosure {
103 oop _obj;
104 outputStream* _st;
105 public:
106 FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}
107 void do_field(fieldDescriptor* fd);
108 };
109 #endif // !PRODUCT
110
111 // ValueObjs embedded in klass. Describes where oops are located in instances of
112 // this klass.
113 class OopMapBlock VALUE_OBJ_CLASS_SPEC {
114 public:
115 // Byte offset of the first oop mapped by this block.
116 int offset() const { return _offset; }
117 void set_offset(int offset) { _offset = offset; }
118
119 // Number of oops in this block.
120 uint count() const { return _count; }
121 void set_count(uint count) { _count = count; }
122
123 // sizeof(OopMapBlock) in HeapWords.
124 static const int size_in_words() {
125 return align_size_up(int(sizeof(OopMapBlock)), HeapWordSize) >>
126 LogHeapWordSize;
127 }
128
129 private:
130 int _offset;
131 uint _count;
132 };
133
134 class InstanceKlass: public Klass {
135 friend class VMStructs;
136 friend class ClassFileParser;
137 friend class CompileReplay;
138
139 protected:
140 // Constructor
141 InstanceKlass(int vtable_len,
142 int itable_len,
143 int static_field_size,
144 int nonstatic_oop_map_size,
145 ReferenceType rt,
146 AccessFlags access_flags,
147 bool is_anonymous);
148 public:
149 static InstanceKlass* allocate_instance_klass(
150 ClassLoaderData* loader_data,
151 int vtable_len,
152 int itable_len,
153 int static_field_size,
154 int nonstatic_oop_map_size,
155 ReferenceType rt,
156 AccessFlags access_flags,
157 Symbol* name,
158 Klass* super_klass,
159 bool is_anonymous,
160 TRAPS);
161
162 InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
163
164 // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
165 // of the class loading & initialization procedure, and the use of the states.
166 enum ClassState {
167 allocated, // allocated (but not yet linked)
168 loaded, // loaded and inserted in class hierarchy (but not linked yet)
169 linked, // successfully linked/verified (but not initialized yet)
170 being_initialized, // currently running class initializer
171 fully_initialized, // initialized (successfull final state)
172 initialization_error // error happened during initialization
173 };
174
175 static int number_of_instance_classes() { return _total_instanceKlass_count; }
176
177 private:
178 static volatile int _total_instanceKlass_count;
179
180 protected:
181 // Annotations for this class
182 Annotations* _annotations;
183 // Array classes holding elements of this class.
184 Klass* _array_klasses;
185 // Constant pool for this class.
186 ConstantPool* _constants;
187 // The InnerClasses attribute and EnclosingMethod attribute. The
188 // _inner_classes is an array of shorts. If the class has InnerClasses
189 // attribute, then the _inner_classes array begins with 4-tuples of shorts
190 // [inner_class_info_index, outer_class_info_index,
191 // inner_name_index, inner_class_access_flags] for the InnerClasses
192 // attribute. If the EnclosingMethod attribute exists, it occupies the
193 // last two shorts [class_index, method_index] of the array. If only
194 // the InnerClasses attribute exists, the _inner_classes array length is
195 // number_of_inner_classes * 4. If the class has both InnerClasses
196 // and EnclosingMethod attributes the _inner_classes array length is
197 // number_of_inner_classes * 4 + enclosing_method_attribute_size.
198 Array<jushort>* _inner_classes;
199
200 // Name of source file containing this klass, NULL if not specified.
201 Symbol* _source_file_name;
202 // the source debug extension for this klass, NULL if not specified.
203 // Specified as UTF-8 string without terminating zero byte in the classfile,
204 // it is stored in the instanceklass as a NULL-terminated UTF-8 string
205 char* _source_debug_extension;
206 // Generic signature, or null if none.
207 Symbol* _generic_signature;
208 // Array name derived from this class which needs unreferencing
209 // if this class is unloaded.
210 Symbol* _array_name;
211
212 // Number of heapOopSize words used by non-static fields in this klass
213 // (including inherited fields but after header_size()).
214 int _nonstatic_field_size;
215 int _static_field_size; // number words used by static fields (oop and non-oop) in this klass
216 u2 _static_oop_field_count;// number of static oop fields in this klass
217 u2 _java_fields_count; // The number of declared Java fields
218 int _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
219
220 // _is_marked_dependent can be set concurrently, thus cannot be part of the
221 // _misc_flags.
222 bool _is_marked_dependent; // used for marking during flushing and deoptimization
223
224 enum {
225 _misc_rewritten = 1 << 0, // methods rewritten.
226 _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
227 _misc_should_verify_class = 1 << 2, // allow caching of preverification
228 _misc_is_anonymous = 1 << 3, // has embedded _host_klass field
229 _misc_is_contended = 1 << 4, // marked with contended annotation
230 _misc_has_default_methods = 1 << 5 // class/superclass/implemented interfaces has default methods
231 };
232 u2 _misc_flags;
233 u2 _minor_version; // minor version number of class file
234 u2 _major_version; // major version number of class file
235 Thread* _init_thread; // Pointer to current thread doing initialization (to handle recusive initialization)
236 int _vtable_len; // length of Java vtable (in words)
237 int _itable_len; // length of Java itable (in words)
238 OopMapCache* volatile _oop_map_cache; // OopMapCache for all methods in the klass (allocated lazily)
239 MemberNameTable* _member_names; // Member names
240 JNIid* _jni_ids; // First JNI identifier for static fields in this class
241 jmethodID* _methods_jmethod_ids; // jmethodIDs corresponding to method_idnum, or NULL if none
242 int* _methods_cached_itable_indices; // itable_index cache for JNI invoke corresponding to methods idnum, or NULL
243 nmethodBucket* _dependencies; // list of dependent nmethods
244 nmethod* _osr_nmethods_head; // Head of list of on-stack replacement nmethods for this class
245 BreakpointInfo* _breakpoints; // bpt lists, managed by Method*
246 // Array of interesting part(s) of the previous version(s) of this
247 // InstanceKlass. See PreviousVersionWalker below.
248 GrowableArray<PreviousVersionNode *>* _previous_versions;
249 // JVMTI fields can be moved to their own structure - see 6315920
250 unsigned char * _cached_class_file_bytes; // JVMTI: cached class file, before retransformable agent modified it in CFLH
251 jint _cached_class_file_len; // JVMTI: length of above
252
253 volatile u2 _idnum_allocated_count; // JNI/JVMTI: increments with the addition of methods, old ids don't change
254
255 // Class states are defined as ClassState (see above).
256 // Place the _init_state here to utilize the unused 2-byte after
257 // _idnum_allocated_count.
258 u1 _init_state; // state of class
259 u1 _reference_type; // reference type
260
261 JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map; // JVMTI: used during heap iteration
262
263 NOT_PRODUCT(int _verify_count;) // to avoid redundant verifies
264
265 // Method array.
266 Array<Method*>* _methods;
267 // Interface (Klass*s) this class declares locally to implement.
268 Array<Klass*>* _local_interfaces;
269 // Interface (Klass*s) this class implements transitively.
270 Array<Klass*>* _transitive_interfaces;
271 // Int array containing the original order of method in the class file (for JVMTI).
272 Array<int>* _method_ordering;
273 // Instance and static variable information, starts with 6-tuples of shorts
274 // [access, name index, sig index, initval index, low_offset, high_offset]
275 // for all fields, followed by the generic signature data at the end of
276 // the array. Only fields with generic signature attributes have the generic
277 // signature data set in the array. The fields array looks like following:
278 //
279 // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
280 // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
281 // ...
282 // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
283 // [generic signature index]
284 // [generic signature index]
285 // ...
286 Array<u2>* _fields;
287
288 // embedded Java vtable follows here
289 // embedded Java itables follows here
290 // embedded static fields follows here
291 // embedded nonstatic oop-map blocks follows here
292 // embedded implementor of this interface follows here
293 // The embedded implementor only exists if the current klass is an
294 // iterface. The possible values of the implementor fall into following
295 // three cases:
296 // NULL: no implementor.
297 // A Klass* that's not itself: one implementor.
298 // Itsef: more than one implementors.
299 // embedded host klass follows here
300 // The embedded host klass only exists in an anonymous class for
301 // dynamic language support (JSR 292 enabled). The host class grants
302 // its access privileges to this class also. The host class is either
303 // named, or a previously loaded anonymous class. A non-anonymous class
304 // or an anonymous class loaded through normal classloading does not
305 // have this embedded field.
306 //
307
308 friend class SystemDictionary;
309
310 public:
311 bool has_nonstatic_fields() const {
312 return (_misc_flags & _misc_has_nonstatic_fields) != 0;
313 }
314 void set_has_nonstatic_fields(bool b) {
315 if (b) {
316 _misc_flags |= _misc_has_nonstatic_fields;
317 } else {
318 _misc_flags &= ~_misc_has_nonstatic_fields;
319 }
320 }
321
322 // field sizes
323 int nonstatic_field_size() const { return _nonstatic_field_size; }
324 void set_nonstatic_field_size(int size) { _nonstatic_field_size = size; }
325
326 int static_field_size() const { return _static_field_size; }
327 void set_static_field_size(int size) { _static_field_size = size; }
328
329 int static_oop_field_count() const { return (int)_static_oop_field_count; }
330 void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
331
332 // Java vtable
333 int vtable_length() const { return _vtable_len; }
334 void set_vtable_length(int len) { _vtable_len = len; }
335
336 // Java itable
337 int itable_length() const { return _itable_len; }
338 void set_itable_length(int len) { _itable_len = len; }
339
340 // array klasses
341 Klass* array_klasses() const { return _array_klasses; }
342 void set_array_klasses(Klass* k) { _array_klasses = k; }
343
344 // methods
345 Array<Method*>* methods() const { return _methods; }
346 void set_methods(Array<Method*>* a) { _methods = a; }
347 Method* method_with_idnum(int idnum);
348
349 // method ordering
350 Array<int>* method_ordering() const { return _method_ordering; }
351 void set_method_ordering(Array<int>* m) { _method_ordering = m; }
352 void copy_method_ordering(intArray* m, TRAPS);
353
354 // interfaces
355 Array<Klass*>* local_interfaces() const { return _local_interfaces; }
356 void set_local_interfaces(Array<Klass*>* a) {
357 guarantee(_local_interfaces == NULL || a == NULL, "Just checking");
358 _local_interfaces = a; }
359
360 Array<Klass*>* transitive_interfaces() const { return _transitive_interfaces; }
361 void set_transitive_interfaces(Array<Klass*>* a) {
362 guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");
363 _transitive_interfaces = a;
364 }
365
366 private:
367 friend class fieldDescriptor;
368 FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
369
370 public:
371 int field_offset (int index) const { return field(index)->offset(); }
372 int field_access_flags(int index) const { return field(index)->access_flags(); }
373 Symbol* field_name (int index) const { return field(index)->name(constants()); }
374 Symbol* field_signature (int index) const { return field(index)->signature(constants()); }
375
376 // Number of Java declared fields
377 int java_fields_count() const { return (int)_java_fields_count; }
378
379 Array<u2>* fields() const { return _fields; }
380 void set_fields(Array<u2>* f, u2 java_fields_count) {
381 guarantee(_fields == NULL || f == NULL, "Just checking");
382 _fields = f;
383 _java_fields_count = java_fields_count;
384 }
385
386 // inner classes
387 Array<u2>* inner_classes() const { return _inner_classes; }
388 void set_inner_classes(Array<u2>* f) { _inner_classes = f; }
389
390 enum InnerClassAttributeOffset {
391 // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
392 inner_class_inner_class_info_offset = 0,
393 inner_class_outer_class_info_offset = 1,
394 inner_class_inner_name_offset = 2,
395 inner_class_access_flags_offset = 3,
396 inner_class_next_offset = 4
397 };
398
399 enum EnclosingMethodAttributeOffset {
400 enclosing_method_class_index_offset = 0,
401 enclosing_method_method_index_offset = 1,
402 enclosing_method_attribute_size = 2
403 };
404
405 // method override check
406 bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
407
408 // package
409 bool is_same_class_package(Klass* class2);
410 bool is_same_class_package(oop classloader2, Symbol* classname2);
411 static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
412
413 // find an enclosing class (defined where original code was, in jvm.cpp!)
414 Klass* compute_enclosing_class(bool* inner_is_member, TRAPS) {
415 instanceKlassHandle self(THREAD, this);
416 return compute_enclosing_class_impl(self, inner_is_member, THREAD);
417 }
418 static Klass* compute_enclosing_class_impl(instanceKlassHandle self,
419 bool* inner_is_member, TRAPS);
420
421 // tell if two classes have the same enclosing class (at package level)
422 bool is_same_package_member(Klass* class2, TRAPS) {
423 instanceKlassHandle self(THREAD, this);
424 return is_same_package_member_impl(self, class2, THREAD);
425 }
426 static bool is_same_package_member_impl(instanceKlassHandle self,
427 Klass* class2, TRAPS);
428
429 // initialization state
430 bool is_loaded() const { return _init_state >= loaded; }
431 bool is_linked() const { return _init_state >= linked; }
432 bool is_initialized() const { return _init_state == fully_initialized; }
433 bool is_not_initialized() const { return _init_state < being_initialized; }
434 bool is_being_initialized() const { return _init_state == being_initialized; }
435 bool is_in_error_state() const { return _init_state == initialization_error; }
436 bool is_reentrant_initialization(Thread *thread) { return thread == _init_thread; }
437 ClassState init_state() { return (ClassState)_init_state; }
438 bool is_rewritten() const { return (_misc_flags & _misc_rewritten) != 0; }
439
440 // defineClass specified verification
441 bool should_verify_class() const {
442 return (_misc_flags & _misc_should_verify_class) != 0;
443 }
444 void set_should_verify_class(bool value) {
445 if (value) {
446 _misc_flags |= _misc_should_verify_class;
447 } else {
448 _misc_flags &= ~_misc_should_verify_class;
449 }
450 }
451
452 // marking
453 bool is_marked_dependent() const { return _is_marked_dependent; }
454 void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
455
456 // initialization (virtuals from Klass)
457 bool should_be_initialized() const; // means that initialize should be called
458 void initialize(TRAPS);
459 void link_class(TRAPS);
460 bool link_class_or_fail(TRAPS); // returns false on failure
461 void unlink_class();
462 void rewrite_class(TRAPS);
463 void link_methods(TRAPS);
464 Method* class_initializer();
465
466 // set the class to initialized if no static initializer is present
467 void eager_initialize(Thread *thread);
468
469 // reference type
470 ReferenceType reference_type() const { return (ReferenceType)_reference_type; }
471 void set_reference_type(ReferenceType t) {
472 assert(t == (u1)t, "overflow");
473 _reference_type = (u1)t;
474 }
475
476 static ByteSize reference_type_offset() { return in_ByteSize(offset_of(InstanceKlass, _reference_type)); }
477
478 // find local field, returns true if found
479 bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
480 // find field in direct superinterfaces, returns the interface in which the field is defined
481 Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
482 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
483 Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
484 // find instance or static fields 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, bool is_static, fieldDescriptor* fd) const;
486
487 // find a non-static or static field given its offset within the class.
488 bool contains_field_offset(int offset) {
489 return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
490 }
491
492 bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
493 bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
494
495 // find a local method (returns NULL if not found)
496 Method* find_method(Symbol* name, Symbol* signature) const;
497 static Method* find_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
498
499 // lookup operation (returns NULL if not found)
500 Method* uncached_lookup_method(Symbol* name, Symbol* signature) const;
501
502 // lookup a method in all the interfaces that this class implements
503 // (returns NULL if not found)
504 Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature) const;
505
506 // Find method indices by name. If a method with the specified name is
507 // found the index to the first method is returned, and 'end' is filled in
508 // with the index of first non-name-matching method. If no method is found
509 // -1 is returned.
510 int find_method_by_name(Symbol* name, int* end);
511 static int find_method_by_name(Array<Method*>* methods, Symbol* name, int* end);
512
513 // constant pool
514 ConstantPool* constants() const { return _constants; }
515 void set_constants(ConstantPool* c) { _constants = c; }
516
517 // protection domain
518 oop protection_domain() const;
519
520 // signers
521 objArrayOop signers() const;
522
523 // host class
524 Klass* host_klass() const {
525 Klass** hk = (Klass**)adr_host_klass();
526 if (hk == NULL) {
527 return NULL;
528 } else {
529 return *hk;
530 }
531 }
532 void set_host_klass(Klass* host) {
533 assert(is_anonymous(), "not anonymous");
534 Klass** addr = (Klass**)adr_host_klass();
535 assert(addr != NULL, "no reversed space");
536 if (addr != NULL) {
537 *addr = host;
538 }
539 }
540 bool is_anonymous() const {
541 return (_misc_flags & _misc_is_anonymous) != 0;
542 }
543 void set_is_anonymous(bool value) {
544 if (value) {
545 _misc_flags |= _misc_is_anonymous;
546 } else {
547 _misc_flags &= ~_misc_is_anonymous;
548 }
549 }
550
551 // Oop that keeps the metadata for this class from being unloaded
552 // in places where the metadata is stored in other places, like nmethods
553 oop klass_holder() const {
554 return is_anonymous() ? java_mirror() : class_loader();
555 }
556
557 bool is_contended() const {
558 return (_misc_flags & _misc_is_contended) != 0;
559 }
560 void set_is_contended(bool value) {
561 if (value) {
562 _misc_flags |= _misc_is_contended;
563 } else {
564 _misc_flags &= ~_misc_is_contended;
565 }
566 }
567
568 // source file name
569 Symbol* source_file_name() const { return _source_file_name; }
570 void set_source_file_name(Symbol* n);
571
572 // minor and major version numbers of class file
573 u2 minor_version() const { return _minor_version; }
574 void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
575 u2 major_version() const { return _major_version; }
576 void set_major_version(u2 major_version) { _major_version = major_version; }
577
578 // source debug extension
579 char* source_debug_extension() const { return _source_debug_extension; }
580 void set_source_debug_extension(char* array, int length);
581
582 // symbol unloading support (refcount already added)
583 Symbol* array_name() { return _array_name; }
584 void set_array_name(Symbol* name) { assert(_array_name == NULL || name == NULL, "name already created"); _array_name = name; }
585
586 // nonstatic oop-map blocks
587 static int nonstatic_oop_map_size(unsigned int oop_map_count) {
588 return oop_map_count * OopMapBlock::size_in_words();
589 }
590 unsigned int nonstatic_oop_map_count() const {
591 return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
592 }
593 int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
594 void set_nonstatic_oop_map_size(int words) {
595 _nonstatic_oop_map_size = words;
596 }
597
598 // RedefineClasses() support for previous versions:
599 void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
600 int emcp_method_count);
601 // If the _previous_versions array is non-NULL, then this klass
602 // has been redefined at least once even if we aren't currently
603 // tracking a previous version.
604 bool has_been_redefined() const { return _previous_versions != NULL; }
605 bool has_previous_version() const;
606 void init_previous_versions() {
607 _previous_versions = NULL;
608 }
609 GrowableArray<PreviousVersionNode *>* previous_versions() const {
610 return _previous_versions;
611 }
612
613 static void purge_previous_versions(InstanceKlass* ik);
614
615 // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
616 void set_cached_class_file(unsigned char *class_file_bytes,
617 jint class_file_len) { _cached_class_file_len = class_file_len;
618 _cached_class_file_bytes = class_file_bytes; }
619 jint get_cached_class_file_len() { return _cached_class_file_len; }
620 unsigned char * get_cached_class_file_bytes() { return _cached_class_file_bytes; }
621
622 // JVMTI: Support for caching of field indices, types, and offsets
623 void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
624 _jvmti_cached_class_field_map = descriptor;
625 }
626 JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
627 return _jvmti_cached_class_field_map;
628 }
629
630 bool has_default_methods() const {
631 return (_misc_flags & _misc_has_default_methods) != 0;
632 }
633 void set_has_default_methods(bool b) {
634 if (b) {
635 _misc_flags |= _misc_has_default_methods;
636 } else {
637 _misc_flags &= ~_misc_has_default_methods;
638 }
639 }
640
641 // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
642 inline u2 next_method_idnum();
643 void set_initial_method_idnum(u2 value) { _idnum_allocated_count = value; }
644
645 // generics support
646 Symbol* generic_signature() const { return _generic_signature; }
647 void set_generic_signature(Symbol* sig) { _generic_signature = sig; }
648
649 u2 enclosing_method_data(int offset);
650 u2 enclosing_method_class_index() {
651 return enclosing_method_data(enclosing_method_class_index_offset);
652 }
653 u2 enclosing_method_method_index() {
654 return enclosing_method_data(enclosing_method_method_index_offset);
655 }
656 void set_enclosing_method_indices(u2 class_index,
657 u2 method_index);
658
659 // jmethodID support
660 static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
661 methodHandle method_h);
662 static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
663 size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
664 jmethodID* to_dealloc_id_p,
665 jmethodID** to_dealloc_jmeths_p);
666 static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
667 size_t *length_p, jmethodID* id_p);
668 jmethodID jmethod_id_or_null(Method* method);
669
670 // cached itable index support
671 void set_cached_itable_index(size_t idnum, int index);
672 int cached_itable_index(size_t idnum);
673
674 // annotations support
675 Annotations* annotations() const { return _annotations; }
676 void set_annotations(Annotations* anno) { _annotations = anno; }
677
678 AnnotationArray* class_annotations() const {
679 return (_annotations != NULL) ? _annotations->class_annotations() : NULL;
680 }
681 Array<AnnotationArray*>* fields_annotations() const {
682 return (_annotations != NULL) ? _annotations->fields_annotations() : NULL;
683 }
684 AnnotationArray* class_type_annotations() const {
685 return (_annotations != NULL) ? _annotations->class_type_annotations() : NULL;
686 }
687 Array<AnnotationArray*>* fields_type_annotations() const {
688 return (_annotations != NULL) ? _annotations->fields_type_annotations() : NULL;
689 }
690 // allocation
691 instanceOop allocate_instance(TRAPS);
692
693 // additional member function to return a handle
694 instanceHandle allocate_instance_handle(TRAPS) { return instanceHandle(THREAD, allocate_instance(THREAD)); }
695
696 objArrayOop allocate_objArray(int n, int length, TRAPS);
697 // Helper function
698 static instanceOop register_finalizer(instanceOop i, TRAPS);
699
700 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
701 // if not, throw either an Error or an Exception.
702 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
703
704 // initialization
705 void call_class_initializer(TRAPS);
706 void set_initialization_state_and_notify(ClassState state, TRAPS);
707
708 // OopMapCache support
709 OopMapCache* oop_map_cache() { return _oop_map_cache; }
710 void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
711 void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
712
713 // JNI identifier support (for static fields - for jni performance)
714 JNIid* jni_ids() { return _jni_ids; }
715 void set_jni_ids(JNIid* ids) { _jni_ids = ids; }
716 JNIid* jni_id_for(int offset);
717
718 // maintenance of deoptimization dependencies
719 int mark_dependent_nmethods(DepChange& changes);
720 void add_dependent_nmethod(nmethod* nm);
721 void remove_dependent_nmethod(nmethod* nm);
722
723 // On-stack replacement support
724 nmethod* osr_nmethods_head() const { return _osr_nmethods_head; };
725 void set_osr_nmethods_head(nmethod* h) { _osr_nmethods_head = h; };
726 void add_osr_nmethod(nmethod* n);
727 void remove_osr_nmethod(nmethod* n);
728 nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
729
730 // Breakpoint support (see methods on Method* for details)
731 BreakpointInfo* breakpoints() const { return _breakpoints; };
732 void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
733
734 // support for stub routines
735 static ByteSize init_state_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_state)); }
736 TRACE_DEFINE_OFFSET;
737 static ByteSize init_thread_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_thread)); }
738
739 // subclass/subinterface checks
740 bool implements_interface(Klass* k) const;
741
742 // Access to the implementor of an interface.
743 Klass* implementor() const
744 {
745 Klass** k = adr_implementor();
746 if (k == NULL) {
747 return NULL;
748 } else {
749 return *k;
750 }
751 }
752
753 void set_implementor(Klass* k) {
754 assert(is_interface(), "not interface");
755 Klass** addr = adr_implementor();
756 assert(addr != NULL, "null addr");
757 if (addr != NULL) {
758 *addr = k;
759 }
760 }
761
762 int nof_implementors() const {
763 Klass* k = implementor();
764 if (k == NULL) {
765 return 0;
766 } else if (k != this) {
767 return 1;
768 } else {
769 return 2;
770 }
771 }
772
773 void add_implementor(Klass* k); // k is a new class that implements this interface
774 void init_implementor(); // initialize
775
776 // link this class into the implementors list of every interface it implements
777 void process_interfaces(Thread *thread);
778
779 // virtual operations from Klass
780 bool is_leaf_class() const { return _subklass == NULL; }
781 GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
782 bool compute_is_subtype_of(Klass* k);
783 bool can_be_primary_super_slow() const;
784 int oop_size(oop obj) const { return size_helper(); }
785 bool oop_is_instance_slow() const { return true; }
786
787 // Iterators
788 void do_local_static_fields(FieldClosure* cl);
789 void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
790 void do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS);
791
792 void methods_do(void f(Method* method));
793 void array_klasses_do(void f(Klass* k));
794 void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
795 void with_array_klasses_do(void f(Klass* k));
796 bool super_types_do(SuperTypeClosure* blk);
797
798 // Casting from Klass*
799 static InstanceKlass* cast(Klass* k) {
800 assert(k->is_klass(), "must be");
801 assert(k->oop_is_instance(), "cast to InstanceKlass");
802 return (InstanceKlass*) k;
803 }
804
805 InstanceKlass* java_super() const {
806 return (super() == NULL) ? NULL : cast(super());
807 }
808
809 // Sizing (in words)
810 static int header_size() { return align_object_offset(sizeof(InstanceKlass)/HeapWordSize); }
811
812 static int size(int vtable_length, int itable_length,
813 int nonstatic_oop_map_size,
814 bool is_interface, bool is_anonymous) {
815 return align_object_size(header_size() +
816 align_object_offset(vtable_length) +
817 align_object_offset(itable_length) +
818 ((is_interface || is_anonymous) ?
819 align_object_offset(nonstatic_oop_map_size) :
820 nonstatic_oop_map_size) +
821 (is_interface ? (int)sizeof(Klass*)/HeapWordSize : 0) +
822 (is_anonymous ? (int)sizeof(Klass*)/HeapWordSize : 0));
823 }
824 int size() const { return size(vtable_length(),
825 itable_length(),
826 nonstatic_oop_map_size(),
827 is_interface(),
828 is_anonymous());
829 }
830 #if INCLUDE_SERVICES
831 virtual void collect_statistics(KlassSizeStats *sz) const;
832 #endif
833
834 static int vtable_start_offset() { return header_size(); }
835 static int vtable_length_offset() { return offset_of(InstanceKlass, _vtable_len) / HeapWordSize; }
836
837 intptr_t* start_of_vtable() const { return ((intptr_t*)this) + vtable_start_offset(); }
838 intptr_t* start_of_itable() const { return start_of_vtable() + align_object_offset(vtable_length()); }
839 int itable_offset_in_words() const { return start_of_itable() - (intptr_t*)this; }
840
841 intptr_t* end_of_itable() const { return start_of_itable() + itable_length(); }
842
843 address static_field_addr(int offset);
844
845 OopMapBlock* start_of_nonstatic_oop_maps() const {
846 return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
847 }
848
849 Klass** end_of_nonstatic_oop_maps() const {
850 return (Klass**)(start_of_nonstatic_oop_maps() +
851 nonstatic_oop_map_count());
852 }
853
854 Klass** adr_implementor() const {
855 if (is_interface()) {
856 return (Klass**)end_of_nonstatic_oop_maps();
857 } else {
858 return NULL;
859 }
860 };
861
862 Klass** adr_host_klass() const {
863 if (is_anonymous()) {
864 Klass** adr_impl = adr_implementor();
865 if (adr_impl != NULL) {
866 return adr_impl + 1;
867 } else {
868 return end_of_nonstatic_oop_maps();
869 }
870 } else {
871 return NULL;
872 }
873 }
874
875 // Allocation profiling support
876 juint alloc_size() const { return _alloc_count * size_helper(); }
877 void set_alloc_size(juint n) {}
878
879 // Use this to return the size of an instance in heap words:
880 int size_helper() const {
881 return layout_helper_to_size_helper(layout_helper());
882 }
883
884 // This bit is initialized in classFileParser.cpp.
885 // It is false under any of the following conditions:
886 // - the class is abstract (including any interface)
887 // - the class has a finalizer (if !RegisterFinalizersAtInit)
888 // - the class size is larger than FastAllocateSizeLimit
889 // - the class is java/lang/Class, which cannot be allocated directly
890 bool can_be_fastpath_allocated() const {
891 return !layout_helper_needs_slow_path(layout_helper());
892 }
893
894 // Java vtable/itable
895 klassVtable* vtable() const; // return new klassVtable wrapper
896 inline Method* method_at_vtable(int index);
897 klassItable* itable() const; // return new klassItable wrapper
898 Method* method_at_itable(Klass* holder, int index, TRAPS);
899
900 // Garbage collection
901 void oop_follow_contents(oop obj);
902 int oop_adjust_pointers(oop obj);
903
904 void clean_implementors_list(BoolObjectClosure* is_alive);
905 void clean_method_data(BoolObjectClosure* is_alive);
906
907 // Explicit metaspace deallocation of fields
908 // For RedefineClasses and class file parsing errors, we need to deallocate
909 // instanceKlasses and the metadata they point to.
910 void deallocate_contents(ClassLoaderData* loader_data);
911 static void deallocate_methods(ClassLoaderData* loader_data,
912 Array<Method*>* methods);
913 void static deallocate_interfaces(ClassLoaderData* loader_data,
914 Klass* super_klass,
915 Array<Klass*>* local_interfaces,
916 Array<Klass*>* transitive_interfaces);
917
918 // The constant pool is on stack if any of the methods are executing or
919 // referenced by handles.
920 bool on_stack() const { return _constants->on_stack(); }
921
922 // callbacks for actions during class unloading
923 static void notify_unload_class(InstanceKlass* ik);
924 static void release_C_heap_structures(InstanceKlass* ik);
925
926 // Parallel Scavenge and Parallel Old
927 PARALLEL_GC_DECLS
928
929 // Naming
930 const char* signature_name() const;
931
932 // Iterators
933 int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) {
934 return oop_oop_iterate_v(obj, blk);
935 }
936
937 int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) {
938 return oop_oop_iterate_v_m(obj, blk, mr);
939 }
940
941 #define InstanceKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
942 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \
943 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, \
944 MemRegion mr);
945
946 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DECL)
947 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DECL)
948
949 #if INCLUDE_ALL_GCS
950 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
951 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
952
953 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
954 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
955 #endif // INCLUDE_ALL_GCS
956
957 u2 idnum_allocated_count() const { return _idnum_allocated_count; }
958
959 private:
960 // initialization state
961 #ifdef ASSERT
962 void set_init_state(ClassState state);
963 #else
964 void set_init_state(ClassState state) { _init_state = (u1)state; }
965 #endif
966 void set_rewritten() { _misc_flags |= _misc_rewritten; }
967 void set_init_thread(Thread *thread) { _init_thread = thread; }
968
969 // The RedefineClasses() API can cause new method idnums to be needed
970 // which will cause the caches to grow. Safety requires different
971 // cache management logic if the caches can grow instead of just
972 // going from NULL to non-NULL.
973 bool idnum_can_increment() const { return has_been_redefined(); }
974 jmethodID* methods_jmethod_ids_acquire() const
975 { return (jmethodID*)OrderAccess::load_ptr_acquire(&_methods_jmethod_ids); }
976 void release_set_methods_jmethod_ids(jmethodID* jmeths)
977 { OrderAccess::release_store_ptr(&_methods_jmethod_ids, jmeths); }
978
979 int* methods_cached_itable_indices_acquire() const
980 { return (int*)OrderAccess::load_ptr_acquire(&_methods_cached_itable_indices); }
981 void release_set_methods_cached_itable_indices(int* indices)
982 { OrderAccess::release_store_ptr(&_methods_cached_itable_indices, indices); }
983
984 // Lock during initialization
985 public:
986 // Lock for (1) initialization; (2) access to the ConstantPool of this class.
987 // Must be one per class and it has to be a VM internal object so java code
988 // cannot lock it (like the mirror).
989 // It has to be an object not a Mutex because it's held through java calls.
990 volatile oop init_lock() const;
991 private:
992
993 // Static methods that are used to implement member methods where an exposed this pointer
994 // is needed due to possible GCs
995 static bool link_class_impl (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
996 static bool verify_code (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
997 static void initialize_impl (instanceKlassHandle this_oop, TRAPS);
998 static void eager_initialize_impl (instanceKlassHandle this_oop);
999 static void set_initialization_state_and_notify_impl (instanceKlassHandle this_oop, ClassState state, TRAPS);
1000 static void call_class_initializer_impl (instanceKlassHandle this_oop, TRAPS);
1001 static Klass* array_klass_impl (instanceKlassHandle this_oop, bool or_null, int n, TRAPS);
1002 static void do_local_static_fields_impl (instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS);
1003 /* jni_id_for_impl for jfieldID only */
1004 static JNIid* jni_id_for_impl (instanceKlassHandle this_oop, int offset);
1005
1006 // Returns the array class for the n'th dimension
1007 Klass* array_klass_impl(bool or_null, int n, TRAPS);
1008
1009 // Returns the array class with this class as element type
1010 Klass* array_klass_impl(bool or_null, TRAPS);
1011
1012 // Free CHeap allocated fields.
1013 void release_C_heap_structures();
1014 public:
1015 // CDS support - remove and restore oops from metadata. Oops are not shared.
1016 virtual void remove_unshareable_info();
1017 virtual void restore_unshareable_info(TRAPS);
1018
1019 // jvm support
1020 jint compute_modifier_flags(TRAPS) const;
1021
1022 // JSR-292 support
1023 MemberNameTable* member_names() { return _member_names; }
1024 void set_member_names(MemberNameTable* member_names) { _member_names = member_names; }
1025 void add_member_name(int index, Handle member_name);
1026 oop get_member_name(int index);
1027
1028 public:
1029 // JVMTI support
1030 jint jvmti_class_status() const;
1031
1032 public:
1033 // Printing
1034 #ifndef PRODUCT
1035 void print_on(outputStream* st) const;
1036 #endif
1037 void print_value_on(outputStream* st) const;
1038
1039 void oop_print_value_on(oop obj, outputStream* st);
1040
1041 #ifndef PRODUCT
1042 void oop_print_on (oop obj, outputStream* st);
1043
1044 void print_dependent_nmethods(bool verbose = false);
1045 bool is_dependent_nmethod(nmethod* nm);
1046 #endif
1047
1048 const char* internal_name() const;
1049
1050 // Verification
1051 void verify_on(outputStream* st);
1052
1053 void oop_verify_on(oop obj, outputStream* st);
1054 };
1055
1056 inline Method* InstanceKlass::method_at_vtable(int index) {
1057 #ifndef PRODUCT
1058 assert(index >= 0, "valid vtable index");
1059 if (DebugVtables) {
1060 verify_vtable_index(index);
1061 }
1062 #endif
1063 vtableEntry* ve = (vtableEntry*)start_of_vtable();
1064 return ve[index].method();
1065 }
1066
1067 // for adding methods
1068 // UNSET_IDNUM return means no more ids available
1069 inline u2 InstanceKlass::next_method_idnum() {
1070 if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1071 return ConstMethod::UNSET_IDNUM; // no more ids available
1072 } else {
1073 return _idnum_allocated_count++;
1074 }
1075 }
1076
1077
1078 /* JNIid class for jfieldIDs only */
1079 class JNIid: public CHeapObj<mtClass> {
1080 friend class VMStructs;
1081 private:
1082 Klass* _holder;
1083 JNIid* _next;
1084 int _offset;
1085 #ifdef ASSERT
1086 bool _is_static_field_id;
1087 #endif
1088
1089 public:
1090 // Accessors
1091 Klass* holder() const { return _holder; }
1092 int offset() const { return _offset; }
1093 JNIid* next() { return _next; }
1094 // Constructor
1095 JNIid(Klass* holder, int offset, JNIid* next);
1096 // Identifier lookup
1097 JNIid* find(int offset);
1098
1099 bool find_local_field(fieldDescriptor* fd) {
1100 return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1101 }
1102
1103 static void deallocate(JNIid* id);
1104 // Debugging
1105 #ifdef ASSERT
1106 bool is_static_field_id() const { return _is_static_field_id; }
1107 void set_is_static_field_id() { _is_static_field_id = true; }
1108 #endif
1109 void verify(Klass* holder);
1110 };
1111
1112
1113 // If breakpoints are more numerous than just JVMTI breakpoints,
1114 // consider compressing this data structure.
1115 // It is currently a simple linked list defined in method.hpp.
1116
1117 class BreakpointInfo;
1118
1119
1120 // A collection point for interesting information about the previous
1121 // version(s) of an InstanceKlass. This class uses weak references to
1122 // the information so that the information may be collected as needed
1123 // by the system. If the information is shared, then a regular
1124 // reference must be used because a weak reference would be seen as
1125 // collectible. A GrowableArray of PreviousVersionNodes is attached
1126 // to the InstanceKlass as needed. See PreviousVersionWalker below.
1127 class PreviousVersionNode : public CHeapObj<mtClass> {
1128 private:
1129 // A shared ConstantPool is never collected so we'll always have
1130 // a reference to it so we can update items in the cache. We'll
1131 // have a weak reference to a non-shared ConstantPool until all
1132 // of the methods (EMCP or obsolete) have been collected; the
1133 // non-shared ConstantPool becomes collectible at that point.
1134 ConstantPool* _prev_constant_pool; // regular or weak reference
1135 bool _prev_cp_is_weak; // true if not a shared ConstantPool
1136
1137 // If the previous version of the InstanceKlass doesn't have any
1138 // EMCP methods, then _prev_EMCP_methods will be NULL. If all the
1139 // EMCP methods have been collected, then _prev_EMCP_methods can
1140 // have a length of zero.
1141 GrowableArray<Method*>* _prev_EMCP_methods;
1142
1143 public:
1144 PreviousVersionNode(ConstantPool* prev_constant_pool, bool prev_cp_is_weak,
1145 GrowableArray<Method*>* prev_EMCP_methods);
1146 ~PreviousVersionNode();
1147 ConstantPool* prev_constant_pool() const {
1148 return _prev_constant_pool;
1149 }
1150 GrowableArray<Method*>* prev_EMCP_methods() const {
1151 return _prev_EMCP_methods;
1152 }
1153 };
1154
1155
1156 // A Handle-ized version of PreviousVersionNode.
1157 class PreviousVersionInfo : public ResourceObj {
1158 private:
1159 constantPoolHandle _prev_constant_pool_handle;
1160 // If the previous version of the InstanceKlass doesn't have any
1161 // EMCP methods, then _prev_EMCP_methods will be NULL. Since the
1162 // methods cannot be collected while we hold a handle,
1163 // _prev_EMCP_methods should never have a length of zero.
1164 GrowableArray<methodHandle>* _prev_EMCP_method_handles;
1165
1166 public:
1167 PreviousVersionInfo(PreviousVersionNode *pv_node);
1168 ~PreviousVersionInfo();
1169 constantPoolHandle prev_constant_pool_handle() const {
1170 return _prev_constant_pool_handle;
1171 }
1172 GrowableArray<methodHandle>* prev_EMCP_method_handles() const {
1173 return _prev_EMCP_method_handles;
1174 }
1175 };
1176
1177
1178 // Helper object for walking previous versions. This helper cleans up
1179 // the Handles that it allocates when the helper object is destroyed.
1180 // The PreviousVersionInfo object returned by next_previous_version()
1181 // is only valid until a subsequent call to next_previous_version() or
1182 // the helper object is destroyed.
1183 class PreviousVersionWalker : public StackObj {
1184 private:
1185 GrowableArray<PreviousVersionNode *>* _previous_versions;
1186 int _current_index;
1187 // Fields for cleaning up when we are done walking the previous versions:
1188 // A HandleMark for the PreviousVersionInfo handles:
1189 HandleMark _hm;
1190
1191 // It would be nice to have a ResourceMark field in this helper also,
1192 // but the ResourceMark code says to be careful to delete handles held
1193 // in GrowableArrays _before_ deleting the GrowableArray. Since we
1194 // can't guarantee the order in which the fields are destroyed, we
1195 // have to let the creator of the PreviousVersionWalker object do
1196 // the right thing. Also, adding a ResourceMark here causes an
1197 // include loop.
1198
1199 // A pointer to the current info object so we can handle the deletes.
1200 PreviousVersionInfo * _current_p;
1201
1202 public:
1203 PreviousVersionWalker(InstanceKlass *ik);
1204 ~PreviousVersionWalker();
1205
1206 // Return the interesting information for the next previous version
1207 // of the klass. Returns NULL if there are no more previous versions.
1208 PreviousVersionInfo* next_previous_version();
1209 };
1210
1211
1212 //
1213 // nmethodBucket is used to record dependent nmethods for
1214 // deoptimization. nmethod dependencies are actually <klass, method>
1215 // pairs but we really only care about the klass part for purposes of
1216 // finding nmethods which might need to be deoptimized. Instead of
1217 // recording the method, a count of how many times a particular nmethod
1218 // was recorded is kept. This ensures that any recording errors are
1219 // noticed since an nmethod should be removed as many times are it's
1220 // added.
1221 //
1222 class nmethodBucket: public CHeapObj<mtClass> {
1223 friend class VMStructs;
1224 private:
1225 nmethod* _nmethod;
1226 int _count;
1227 nmethodBucket* _next;
1228
1229 public:
1230 nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
1231 _nmethod = nmethod;
1232 _next = next;
1233 _count = 1;
1234 }
1235 int count() { return _count; }
1236 int increment() { _count += 1; return _count; }
1237 int decrement() { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
1238 nmethodBucket* next() { return _next; }
1239 void set_next(nmethodBucket* b) { _next = b; }
1240 nmethod* get_nmethod() { return _nmethod; }
1241 };
1242
1243 // An iterator that's used to access the inner classes indices in the
1244 // InstanceKlass::_inner_classes array.
1245 class InnerClassesIterator : public StackObj {
1246 private:
1247 Array<jushort>* _inner_classes;
1248 int _length;
1249 int _idx;
1250 public:
1251
1252 InnerClassesIterator(instanceKlassHandle k) {
1253 _inner_classes = k->inner_classes();
1254 if (k->inner_classes() != NULL) {
1255 _length = _inner_classes->length();
1256 // The inner class array's length should be the multiple of
1257 // inner_class_next_offset if it only contains the InnerClasses
1258 // attribute data, or it should be
1259 // n*inner_class_next_offset+enclosing_method_attribute_size
1260 // if it also contains the EnclosingMethod data.
1261 assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1262 _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1263 "just checking");
1264 // Remove the enclosing_method portion if exists.
1265 if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1266 _length -= InstanceKlass::enclosing_method_attribute_size;
1267 }
1268 } else {
1269 _length = 0;
1270 }
1271 _idx = 0;
1272 }
1273
1274 int length() const {
1275 return _length;
1276 }
1277
1278 void next() {
1279 _idx += InstanceKlass::inner_class_next_offset;
1280 }
1281
1282 bool done() const {
1283 return (_idx >= _length);
1284 }
1285
1286 u2 inner_class_info_index() const {
1287 return _inner_classes->at(
1288 _idx + InstanceKlass::inner_class_inner_class_info_offset);
1289 }
1290
1291 void set_inner_class_info_index(u2 index) {
1292 _inner_classes->at_put(
1293 _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1294 }
1295
1296 u2 outer_class_info_index() const {
1297 return _inner_classes->at(
1298 _idx + InstanceKlass::inner_class_outer_class_info_offset);
1299 }
1300
1301 void set_outer_class_info_index(u2 index) {
1302 _inner_classes->at_put(
1303 _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1304 }
1305
1306 u2 inner_name_index() const {
1307 return _inner_classes->at(
1308 _idx + InstanceKlass::inner_class_inner_name_offset);
1309 }
1310
1311 void set_inner_name_index(u2 index) {
1312 _inner_classes->at_put(
1313 _idx + InstanceKlass::inner_class_inner_name_offset, index);
1314 }
1315
1316 u2 inner_access_flags() const {
1317 return _inner_classes->at(
1318 _idx + InstanceKlass::inner_class_access_flags_offset);
1319 }
1320 };
1321
1322 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP