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 struct JvmtiCachedClassFileData;
137
138 class InstanceKlass: public Klass {
139 friend class VMStructs;
140 friend class ClassFileParser;
141 friend class CompileReplay;
142
143 protected:
144 // Constructor
145 InstanceKlass(int vtable_len,
146 int itable_len,
147 int static_field_size,
148 int nonstatic_oop_map_size,
149 ReferenceType rt,
150 AccessFlags access_flags,
151 bool is_anonymous);
152 public:
153 static InstanceKlass* allocate_instance_klass(
154 ClassLoaderData* loader_data,
155 int vtable_len,
156 int itable_len,
157 int static_field_size,
158 int nonstatic_oop_map_size,
159 ReferenceType rt,
160 AccessFlags access_flags,
161 Symbol* name,
162 Klass* super_klass,
163 bool is_anonymous,
164 TRAPS);
165
166 InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
167
168 // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
169 // of the class loading & initialization procedure, and the use of the states.
170 enum ClassState {
171 allocated, // allocated (but not yet linked)
172 loaded, // loaded and inserted in class hierarchy (but not linked yet)
173 linked, // successfully linked/verified (but not initialized yet)
174 being_initialized, // currently running class initializer
175 fully_initialized, // initialized (successfull final state)
176 initialization_error // error happened during initialization
177 };
178
179 static int number_of_instance_classes() { return _total_instanceKlass_count; }
180
181 private:
182 static volatile int _total_instanceKlass_count;
183
184 protected:
185 // Annotations for this class
186 Annotations* _annotations;
187 // Array classes holding elements of this class.
188 Klass* _array_klasses;
189 // Constant pool for this class.
190 ConstantPool* _constants;
191 // The InnerClasses attribute and EnclosingMethod attribute. The
192 // _inner_classes is an array of shorts. If the class has InnerClasses
193 // attribute, then the _inner_classes array begins with 4-tuples of shorts
194 // [inner_class_info_index, outer_class_info_index,
195 // inner_name_index, inner_class_access_flags] for the InnerClasses
196 // attribute. If the EnclosingMethod attribute exists, it occupies the
197 // last two shorts [class_index, method_index] of the array. If only
198 // the InnerClasses attribute exists, the _inner_classes array length is
199 // number_of_inner_classes * 4. If the class has both InnerClasses
200 // and EnclosingMethod attributes the _inner_classes array length is
201 // number_of_inner_classes * 4 + enclosing_method_attribute_size.
202 Array<jushort>* _inner_classes;
203
204 // Name of source file containing this klass, NULL if not specified.
205 Symbol* _source_file_name;
206 // the source debug extension for this klass, NULL if not specified.
207 // Specified as UTF-8 string without terminating zero byte in the classfile,
208 // it is stored in the instanceklass as a NULL-terminated UTF-8 string
209 char* _source_debug_extension;
210 // Generic signature, or null if none.
211 Symbol* _generic_signature;
212 // Array name derived from this class which needs unreferencing
213 // if this class is unloaded.
214 Symbol* _array_name;
215
216 // Number of heapOopSize words used by non-static fields in this klass
217 // (including inherited fields but after header_size()).
218 int _nonstatic_field_size;
219 int _static_field_size; // number words used by static fields (oop and non-oop) in this klass
220 u2 _static_oop_field_count;// number of static oop fields in this klass
221 u2 _java_fields_count; // The number of declared Java fields
222 int _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
223
224 // _is_marked_dependent can be set concurrently, thus cannot be part of the
225 // _misc_flags.
226 bool _is_marked_dependent; // used for marking during flushing and deoptimization
227
228 enum {
229 _misc_rewritten = 1 << 0, // methods rewritten.
230 _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
231 _misc_should_verify_class = 1 << 2, // allow caching of preverification
232 _misc_is_anonymous = 1 << 3, // has embedded _host_klass field
233 _misc_is_contended = 1 << 4, // marked with contended annotation
234 _misc_has_default_methods = 1 << 5 // class/superclass/implemented interfaces has default methods
235 };
236 u2 _misc_flags;
237 u2 _minor_version; // minor version number of class file
238 u2 _major_version; // major version number of class file
239 Thread* _init_thread; // Pointer to current thread doing initialization (to handle recusive initialization)
240 int _vtable_len; // length of Java vtable (in words)
241 int _itable_len; // length of Java itable (in words)
242 OopMapCache* volatile _oop_map_cache; // OopMapCache for all methods in the klass (allocated lazily)
243 MemberNameTable* _member_names; // Member names
244 JNIid* _jni_ids; // First JNI identifier for static fields in this class
245 jmethodID* _methods_jmethod_ids; // jmethodIDs corresponding to method_idnum, or NULL if none
246 int* _methods_cached_itable_indices; // itable_index cache for JNI invoke corresponding to methods idnum, or NULL
247 nmethodBucket* _dependencies; // list of dependent nmethods
248 nmethod* _osr_nmethods_head; // Head of list of on-stack replacement nmethods for this class
249 BreakpointInfo* _breakpoints; // bpt lists, managed by Method*
250 // Array of interesting part(s) of the previous version(s) of this
251 // InstanceKlass. See PreviousVersionWalker below.
252 GrowableArray<PreviousVersionNode *>* _previous_versions;
253 // JVMTI fields can be moved to their own structure - see 6315920
254 // JVMTI: cached class file, before retransformable agent modified it in CFLH
255 JvmtiCachedClassFileData* _cached_class_file;
256
257 volatile u2 _idnum_allocated_count; // JNI/JVMTI: increments with the addition of methods, old ids don't change
258
259 // Class states are defined as ClassState (see above).
260 // Place the _init_state here to utilize the unused 2-byte after
261 // _idnum_allocated_count.
262 u1 _init_state; // state of class
263 u1 _reference_type; // reference type
264
265 JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map; // JVMTI: used during heap iteration
266
267 NOT_PRODUCT(int _verify_count;) // to avoid redundant verifies
268
269 // Method array.
270 Array<Method*>* _methods;
271 // Interface (Klass*s) this class declares locally to implement.
272 Array<Klass*>* _local_interfaces;
273 // Interface (Klass*s) this class implements transitively.
274 Array<Klass*>* _transitive_interfaces;
275 // Int array containing the original order of method in the class file (for JVMTI).
276 Array<int>* _method_ordering;
277 // Instance and static variable information, starts with 6-tuples of shorts
278 // [access, name index, sig index, initval index, low_offset, high_offset]
279 // for all fields, followed by the generic signature data at the end of
280 // the array. Only fields with generic signature attributes have the generic
281 // signature data set in the array. The fields array looks like following:
282 //
283 // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
284 // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
285 // ...
286 // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
287 // [generic signature index]
288 // [generic signature index]
289 // ...
290 Array<u2>* _fields;
291
292 // embedded Java vtable follows here
293 // embedded Java itables follows here
294 // embedded static fields follows here
295 // embedded nonstatic oop-map blocks follows here
296 // embedded implementor of this interface follows here
297 // The embedded implementor only exists if the current klass is an
298 // iterface. The possible values of the implementor fall into following
299 // three cases:
300 // NULL: no implementor.
301 // A Klass* that's not itself: one implementor.
302 // Itsef: more than one implementors.
303 // embedded host klass follows here
304 // The embedded host klass only exists in an anonymous class for
305 // dynamic language support (JSR 292 enabled). The host class grants
306 // its access privileges to this class also. The host class is either
307 // named, or a previously loaded anonymous class. A non-anonymous class
308 // or an anonymous class loaded through normal classloading does not
309 // have this embedded field.
310 //
311
312 friend class SystemDictionary;
313
314 public:
315 bool has_nonstatic_fields() const {
316 return (_misc_flags & _misc_has_nonstatic_fields) != 0;
317 }
318 void set_has_nonstatic_fields(bool b) {
319 if (b) {
320 _misc_flags |= _misc_has_nonstatic_fields;
321 } else {
322 _misc_flags &= ~_misc_has_nonstatic_fields;
323 }
324 }
325
326 // field sizes
327 int nonstatic_field_size() const { return _nonstatic_field_size; }
328 void set_nonstatic_field_size(int size) { _nonstatic_field_size = size; }
329
330 int static_field_size() const { return _static_field_size; }
331 void set_static_field_size(int size) { _static_field_size = size; }
332
333 int static_oop_field_count() const { return (int)_static_oop_field_count; }
334 void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
335
336 // Java vtable
337 int vtable_length() const { return _vtable_len; }
338 void set_vtable_length(int len) { _vtable_len = len; }
339
340 // Java itable
341 int itable_length() const { return _itable_len; }
342 void set_itable_length(int len) { _itable_len = len; }
343
344 // array klasses
345 Klass* array_klasses() const { return _array_klasses; }
346 void set_array_klasses(Klass* k) { _array_klasses = k; }
347
348 // methods
349 Array<Method*>* methods() const { return _methods; }
350 void set_methods(Array<Method*>* a) { _methods = a; }
351 Method* method_with_idnum(int idnum);
352
353 // method ordering
354 Array<int>* method_ordering() const { return _method_ordering; }
355 void set_method_ordering(Array<int>* m) { _method_ordering = m; }
356 void copy_method_ordering(intArray* m, TRAPS);
357
358 // interfaces
359 Array<Klass*>* local_interfaces() const { return _local_interfaces; }
360 void set_local_interfaces(Array<Klass*>* a) {
361 guarantee(_local_interfaces == NULL || a == NULL, "Just checking");
362 _local_interfaces = a; }
363
364 Array<Klass*>* transitive_interfaces() const { return _transitive_interfaces; }
365 void set_transitive_interfaces(Array<Klass*>* a) {
366 guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");
367 _transitive_interfaces = a;
368 }
369
370 private:
371 friend class fieldDescriptor;
372 FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
373
374 public:
375 int field_offset (int index) const { return field(index)->offset(); }
376 int field_access_flags(int index) const { return field(index)->access_flags(); }
377 Symbol* field_name (int index) const { return field(index)->name(constants()); }
378 Symbol* field_signature (int index) const { return field(index)->signature(constants()); }
379
380 // Number of Java declared fields
381 int java_fields_count() const { return (int)_java_fields_count; }
382
383 Array<u2>* fields() const { return _fields; }
384 void set_fields(Array<u2>* f, u2 java_fields_count) {
385 guarantee(_fields == NULL || f == NULL, "Just checking");
386 _fields = f;
387 _java_fields_count = java_fields_count;
388 }
389
390 // inner classes
391 Array<u2>* inner_classes() const { return _inner_classes; }
392 void set_inner_classes(Array<u2>* f) { _inner_classes = f; }
393
394 enum InnerClassAttributeOffset {
395 // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
396 inner_class_inner_class_info_offset = 0,
397 inner_class_outer_class_info_offset = 1,
398 inner_class_inner_name_offset = 2,
399 inner_class_access_flags_offset = 3,
400 inner_class_next_offset = 4
401 };
402
403 enum EnclosingMethodAttributeOffset {
404 enclosing_method_class_index_offset = 0,
405 enclosing_method_method_index_offset = 1,
406 enclosing_method_attribute_size = 2
407 };
408
409 // method override check
410 bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
411
412 // package
413 bool is_same_class_package(Klass* class2);
414 bool is_same_class_package(oop classloader2, Symbol* classname2);
415 static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
416
417 // find an enclosing class (defined where original code was, in jvm.cpp!)
418 Klass* compute_enclosing_class(bool* inner_is_member, TRAPS) {
419 instanceKlassHandle self(THREAD, this);
420 return compute_enclosing_class_impl(self, inner_is_member, THREAD);
421 }
422 static Klass* compute_enclosing_class_impl(instanceKlassHandle self,
423 bool* inner_is_member, TRAPS);
424
425 // tell if two classes have the same enclosing class (at package level)
426 bool is_same_package_member(Klass* class2, TRAPS) {
427 instanceKlassHandle self(THREAD, this);
428 return is_same_package_member_impl(self, class2, THREAD);
429 }
430 static bool is_same_package_member_impl(instanceKlassHandle self,
431 Klass* class2, TRAPS);
432
433 // initialization state
434 bool is_loaded() const { return _init_state >= loaded; }
435 bool is_linked() const { return _init_state >= linked; }
436 bool is_initialized() const { return _init_state == fully_initialized; }
437 bool is_not_initialized() const { return _init_state < being_initialized; }
438 bool is_being_initialized() const { return _init_state == being_initialized; }
439 bool is_in_error_state() const { return _init_state == initialization_error; }
440 bool is_reentrant_initialization(Thread *thread) { return thread == _init_thread; }
441 ClassState init_state() { return (ClassState)_init_state; }
442 bool is_rewritten() const { return (_misc_flags & _misc_rewritten) != 0; }
443
444 // defineClass specified verification
445 bool should_verify_class() const {
446 return (_misc_flags & _misc_should_verify_class) != 0;
447 }
448 void set_should_verify_class(bool value) {
449 if (value) {
450 _misc_flags |= _misc_should_verify_class;
451 } else {
452 _misc_flags &= ~_misc_should_verify_class;
453 }
454 }
455
456 // marking
457 bool is_marked_dependent() const { return _is_marked_dependent; }
458 void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
459
460 // initialization (virtuals from Klass)
461 bool should_be_initialized() const; // means that initialize should be called
462 void initialize(TRAPS);
463 void link_class(TRAPS);
464 bool link_class_or_fail(TRAPS); // returns false on failure
465 void unlink_class();
466 void rewrite_class(TRAPS);
467 void link_methods(TRAPS);
468 Method* class_initializer();
469
470 // set the class to initialized if no static initializer is present
471 void eager_initialize(Thread *thread);
472
473 // reference type
474 ReferenceType reference_type() const { return (ReferenceType)_reference_type; }
475 void set_reference_type(ReferenceType t) {
476 assert(t == (u1)t, "overflow");
477 _reference_type = (u1)t;
478 }
479
480 static ByteSize reference_type_offset() { return in_ByteSize(offset_of(InstanceKlass, _reference_type)); }
481
482 // find local field, returns true if found
483 bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
484 // find field in direct superinterfaces, returns the interface in which the field is defined
485 Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
486 // find field 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, fieldDescriptor* fd) const;
488 // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
489 Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
490
491 // find a non-static or static field given its offset within the class.
492 bool contains_field_offset(int offset) {
493 return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
494 }
495
496 bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
497 bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
498
499 // find a local method (returns NULL if not found)
500 Method* find_method(Symbol* name, Symbol* signature) const;
501 static Method* find_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
502
503 // lookup operation (returns NULL if not found)
504 Method* uncached_lookup_method(Symbol* name, Symbol* signature) const;
505
506 // lookup a method in all the interfaces that this class implements
507 // (returns NULL if not found)
508 Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature) const;
509
510 // Find method indices by name. If a method with the specified name is
511 // found the index to the first method is returned, and 'end' is filled in
512 // with the index of first non-name-matching method. If no method is found
513 // -1 is returned.
514 int find_method_by_name(Symbol* name, int* end);
515 static int find_method_by_name(Array<Method*>* methods, Symbol* name, int* end);
516
517 // constant pool
518 ConstantPool* constants() const { return _constants; }
519 void set_constants(ConstantPool* c) { _constants = c; }
520
521 // protection domain
522 oop protection_domain() const;
523
524 // signers
525 objArrayOop signers() const;
526
527 // host class
528 Klass* host_klass() const {
529 Klass** hk = (Klass**)adr_host_klass();
530 if (hk == NULL) {
531 return NULL;
532 } else {
533 return *hk;
534 }
535 }
536 void set_host_klass(Klass* host) {
537 assert(is_anonymous(), "not anonymous");
538 Klass** addr = (Klass**)adr_host_klass();
539 assert(addr != NULL, "no reversed space");
540 if (addr != NULL) {
541 *addr = host;
542 }
543 }
544 bool is_anonymous() const {
545 return (_misc_flags & _misc_is_anonymous) != 0;
546 }
547 void set_is_anonymous(bool value) {
548 if (value) {
549 _misc_flags |= _misc_is_anonymous;
550 } else {
551 _misc_flags &= ~_misc_is_anonymous;
552 }
553 }
554
555 // Oop that keeps the metadata for this class from being unloaded
556 // in places where the metadata is stored in other places, like nmethods
557 oop klass_holder() const {
558 return is_anonymous() ? java_mirror() : class_loader();
559 }
560
561 bool is_contended() const {
562 return (_misc_flags & _misc_is_contended) != 0;
563 }
564 void set_is_contended(bool value) {
565 if (value) {
566 _misc_flags |= _misc_is_contended;
567 } else {
568 _misc_flags &= ~_misc_is_contended;
569 }
570 }
571
572 // source file name
573 Symbol* source_file_name() const { return _source_file_name; }
574 void set_source_file_name(Symbol* n);
575
576 // minor and major version numbers of class file
577 u2 minor_version() const { return _minor_version; }
578 void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
579 u2 major_version() const { return _major_version; }
580 void set_major_version(u2 major_version) { _major_version = major_version; }
581
582 // source debug extension
583 char* source_debug_extension() const { return _source_debug_extension; }
584 void set_source_debug_extension(char* array, int length);
585
586 // symbol unloading support (refcount already added)
587 Symbol* array_name() { return _array_name; }
588 void set_array_name(Symbol* name) { assert(_array_name == NULL || name == NULL, "name already created"); _array_name = name; }
589
590 // nonstatic oop-map blocks
591 static int nonstatic_oop_map_size(unsigned int oop_map_count) {
592 return oop_map_count * OopMapBlock::size_in_words();
593 }
594 unsigned int nonstatic_oop_map_count() const {
595 return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
596 }
597 int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
598 void set_nonstatic_oop_map_size(int words) {
599 _nonstatic_oop_map_size = words;
600 }
601
602 // RedefineClasses() support for previous versions:
603 void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
604 int emcp_method_count);
605 // If the _previous_versions array is non-NULL, then this klass
606 // has been redefined at least once even if we aren't currently
607 // tracking a previous version.
608 bool has_been_redefined() const { return _previous_versions != NULL; }
609 bool has_previous_version() const;
610 void init_previous_versions() {
611 _previous_versions = NULL;
612 }
613 GrowableArray<PreviousVersionNode *>* previous_versions() const {
614 return _previous_versions;
615 }
616
617 static void purge_previous_versions(InstanceKlass* ik);
618
619 // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
620 void set_cached_class_file(JvmtiCachedClassFileData *data) {
621 _cached_class_file = data;
622 }
623 JvmtiCachedClassFileData * get_cached_class_file() { return _cached_class_file; }
624 jint get_cached_class_file_len();
625 unsigned char * get_cached_class_file_bytes();
626
627 // JVMTI: Support for caching of field indices, types, and offsets
628 void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
629 _jvmti_cached_class_field_map = descriptor;
630 }
631 JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
632 return _jvmti_cached_class_field_map;
633 }
634
635 bool has_default_methods() const {
636 return (_misc_flags & _misc_has_default_methods) != 0;
637 }
638 void set_has_default_methods(bool b) {
639 if (b) {
640 _misc_flags |= _misc_has_default_methods;
641 } else {
642 _misc_flags &= ~_misc_has_default_methods;
643 }
644 }
645
646 // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
647 inline u2 next_method_idnum();
648 void set_initial_method_idnum(u2 value) { _idnum_allocated_count = value; }
649
650 // generics support
651 Symbol* generic_signature() const { return _generic_signature; }
652 void set_generic_signature(Symbol* sig) { _generic_signature = sig; }
653
654 u2 enclosing_method_data(int offset);
655 u2 enclosing_method_class_index() {
656 return enclosing_method_data(enclosing_method_class_index_offset);
657 }
658 u2 enclosing_method_method_index() {
659 return enclosing_method_data(enclosing_method_method_index_offset);
660 }
661 void set_enclosing_method_indices(u2 class_index,
662 u2 method_index);
663
664 // jmethodID support
665 static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
666 methodHandle method_h);
667 static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
668 size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
669 jmethodID* to_dealloc_id_p,
670 jmethodID** to_dealloc_jmeths_p);
671 static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
672 size_t *length_p, jmethodID* id_p);
673 jmethodID jmethod_id_or_null(Method* method);
674
675 // cached itable index support
676 void set_cached_itable_index(size_t idnum, int index);
677 int cached_itable_index(size_t idnum);
678
679 // annotations support
680 Annotations* annotations() const { return _annotations; }
681 void set_annotations(Annotations* anno) { _annotations = anno; }
682
683 AnnotationArray* class_annotations() const {
684 return (_annotations != NULL) ? _annotations->class_annotations() : NULL;
685 }
686 Array<AnnotationArray*>* fields_annotations() const {
687 return (_annotations != NULL) ? _annotations->fields_annotations() : NULL;
688 }
689 AnnotationArray* class_type_annotations() const {
690 return (_annotations != NULL) ? _annotations->class_type_annotations() : NULL;
691 }
692 Array<AnnotationArray*>* fields_type_annotations() const {
693 return (_annotations != NULL) ? _annotations->fields_type_annotations() : NULL;
694 }
695 // allocation
696 instanceOop allocate_instance(TRAPS);
697
698 // additional member function to return a handle
699 instanceHandle allocate_instance_handle(TRAPS) { return instanceHandle(THREAD, allocate_instance(THREAD)); }
700
701 objArrayOop allocate_objArray(int n, int length, TRAPS);
702 // Helper function
703 static instanceOop register_finalizer(instanceOop i, TRAPS);
704
705 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
706 // if not, throw either an Error or an Exception.
707 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
708
709 // initialization
710 void call_class_initializer(TRAPS);
711 void set_initialization_state_and_notify(ClassState state, TRAPS);
712
713 // OopMapCache support
714 OopMapCache* oop_map_cache() { return _oop_map_cache; }
715 void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
716 void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
717
718 // JNI identifier support (for static fields - for jni performance)
719 JNIid* jni_ids() { return _jni_ids; }
720 void set_jni_ids(JNIid* ids) { _jni_ids = ids; }
721 JNIid* jni_id_for(int offset);
722
723 // maintenance of deoptimization dependencies
724 int mark_dependent_nmethods(DepChange& changes);
725 void add_dependent_nmethod(nmethod* nm);
726 void remove_dependent_nmethod(nmethod* nm);
727
728 // On-stack replacement support
729 nmethod* osr_nmethods_head() const { return _osr_nmethods_head; };
730 void set_osr_nmethods_head(nmethod* h) { _osr_nmethods_head = h; };
731 void add_osr_nmethod(nmethod* n);
732 void remove_osr_nmethod(nmethod* n);
733 nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
734
735 // Breakpoint support (see methods on Method* for details)
736 BreakpointInfo* breakpoints() const { return _breakpoints; };
737 void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
738
739 // support for stub routines
740 static ByteSize init_state_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_state)); }
741 TRACE_DEFINE_OFFSET;
742 static ByteSize init_thread_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_thread)); }
743
744 // subclass/subinterface checks
745 bool implements_interface(Klass* k) const;
746
747 // Access to the implementor of an interface.
748 Klass* implementor() const
749 {
750 Klass** k = adr_implementor();
751 if (k == NULL) {
752 return NULL;
753 } else {
754 return *k;
755 }
756 }
757
758 void set_implementor(Klass* k) {
759 assert(is_interface(), "not interface");
760 Klass** addr = adr_implementor();
761 assert(addr != NULL, "null addr");
762 if (addr != NULL) {
763 *addr = k;
764 }
765 }
766
767 int nof_implementors() const {
768 Klass* k = implementor();
769 if (k == NULL) {
770 return 0;
771 } else if (k != this) {
772 return 1;
773 } else {
774 return 2;
775 }
776 }
777
778 void add_implementor(Klass* k); // k is a new class that implements this interface
779 void init_implementor(); // initialize
780
781 // link this class into the implementors list of every interface it implements
782 void process_interfaces(Thread *thread);
783
784 // virtual operations from Klass
785 bool is_leaf_class() const { return _subklass == NULL; }
786 GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
787 bool compute_is_subtype_of(Klass* k);
788 bool can_be_primary_super_slow() const;
789 int oop_size(oop obj) const { return size_helper(); }
790 bool oop_is_instance_slow() const { return true; }
791
792 // Iterators
793 void do_local_static_fields(FieldClosure* cl);
794 void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
795 void do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS);
796
797 void methods_do(void f(Method* method));
798 void array_klasses_do(void f(Klass* k));
799 void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
800 bool super_types_do(SuperTypeClosure* blk);
801
802 // Casting from Klass*
803 static InstanceKlass* cast(Klass* k) {
804 assert(k->is_klass(), "must be");
805 assert(k->oop_is_instance(), "cast to InstanceKlass");
806 return (InstanceKlass*) k;
807 }
808
809 InstanceKlass* java_super() const {
810 return (super() == NULL) ? NULL : cast(super());
811 }
812
813 // Sizing (in words)
814 static int header_size() { return align_object_offset(sizeof(InstanceKlass)/HeapWordSize); }
815
816 static int size(int vtable_length, int itable_length,
817 int nonstatic_oop_map_size,
818 bool is_interface, bool is_anonymous) {
819 return align_object_size(header_size() +
820 align_object_offset(vtable_length) +
821 align_object_offset(itable_length) +
822 ((is_interface || is_anonymous) ?
823 align_object_offset(nonstatic_oop_map_size) :
824 nonstatic_oop_map_size) +
825 (is_interface ? (int)sizeof(Klass*)/HeapWordSize : 0) +
826 (is_anonymous ? (int)sizeof(Klass*)/HeapWordSize : 0));
827 }
828 int size() const { return size(vtable_length(),
829 itable_length(),
830 nonstatic_oop_map_size(),
831 is_interface(),
832 is_anonymous());
833 }
834 #if INCLUDE_SERVICES
835 virtual void collect_statistics(KlassSizeStats *sz) const;
836 #endif
837
838 static int vtable_start_offset() { return header_size(); }
839 static int vtable_length_offset() { return offset_of(InstanceKlass, _vtable_len) / HeapWordSize; }
840
841 intptr_t* start_of_vtable() const { return ((intptr_t*)this) + vtable_start_offset(); }
842 intptr_t* start_of_itable() const { return start_of_vtable() + align_object_offset(vtable_length()); }
843 int itable_offset_in_words() const { return start_of_itable() - (intptr_t*)this; }
844
845 intptr_t* end_of_itable() const { return start_of_itable() + itable_length(); }
846
847 address static_field_addr(int offset);
848
849 OopMapBlock* start_of_nonstatic_oop_maps() const {
850 return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
851 }
852
853 Klass** end_of_nonstatic_oop_maps() const {
854 return (Klass**)(start_of_nonstatic_oop_maps() +
855 nonstatic_oop_map_count());
856 }
857
858 Klass** adr_implementor() const {
859 if (is_interface()) {
860 return (Klass**)end_of_nonstatic_oop_maps();
861 } else {
862 return NULL;
863 }
864 };
865
866 Klass** adr_host_klass() const {
867 if (is_anonymous()) {
868 Klass** adr_impl = adr_implementor();
869 if (adr_impl != NULL) {
870 return adr_impl + 1;
871 } else {
872 return end_of_nonstatic_oop_maps();
873 }
874 } else {
875 return NULL;
876 }
877 }
878
879 // 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, bool check_dictionary);
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