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 // the source debug extension for this klass, NULL if not specified.
205 // Specified as UTF-8 string without terminating zero byte in the classfile,
206 // it is stored in the instanceklass as a NULL-terminated UTF-8 string
207 char* _source_debug_extension;
208 // 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 // Constant pool index to the utf8 entry of the Generic signature,
217 // or 0 if none.
218 u2 _generic_signature_index;
219 // Constant pool index to the utf8 entry for the name of source file
220 // containing this klass, 0 if not specified.
221 u2 _source_file_name_index;
222 u2 _static_oop_field_count;// number of static oop fields in this klass
223 u2 _java_fields_count; // The number of declared Java fields
224 int _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
225
226 // _is_marked_dependent can be set concurrently, thus cannot be part of the
227 // _misc_flags.
228 bool _is_marked_dependent; // used for marking during flushing and deoptimization
229
230 enum {
231 _misc_rewritten = 1 << 0, // methods rewritten.
232 _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
233 _misc_should_verify_class = 1 << 2, // allow caching of preverification
234 _misc_is_anonymous = 1 << 3, // has embedded _host_klass field
235 _misc_is_contended = 1 << 4, // marked with contended annotation
236 _misc_has_default_methods = 1 << 5 // class/superclass/implemented interfaces has default methods
237 };
238 u2 _misc_flags;
239 u2 _minor_version; // minor version number of class file
240 u2 _major_version; // major version number of class file
241 Thread* _init_thread; // Pointer to current thread doing initialization (to handle recusive initialization)
242 int _vtable_len; // length of Java vtable (in words)
243 int _itable_len; // length of Java itable (in words)
244 OopMapCache* volatile _oop_map_cache; // OopMapCache for all methods in the klass (allocated lazily)
245 MemberNameTable* _member_names; // Member names
246 JNIid* _jni_ids; // First JNI identifier for static fields in this class
247 jmethodID* _methods_jmethod_ids; // jmethodIDs corresponding to method_idnum, or NULL if none
248 nmethodBucket* _dependencies; // list of dependent nmethods
249 nmethod* _osr_nmethods_head; // Head of list of on-stack replacement nmethods for this class
250 BreakpointInfo* _breakpoints; // bpt lists, managed by Method*
251 // Array of interesting part(s) of the previous version(s) of this
252 // InstanceKlass. See PreviousVersionWalker below.
253 GrowableArray<PreviousVersionNode *>* _previous_versions;
254 // JVMTI fields can be moved to their own structure - see 6315920
255 // JVMTI: cached class file, before retransformable agent modified it in CFLH
256 JvmtiCachedClassFileData* _cached_class_file;
257
258 volatile u2 _idnum_allocated_count; // JNI/JVMTI: increments with the addition of methods, old ids don't change
259
260 // Class states are defined as ClassState (see above).
261 // Place the _init_state here to utilize the unused 2-byte after
262 // _idnum_allocated_count.
263 u1 _init_state; // state of class
264 u1 _reference_type; // reference type
265
266 JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map; // JVMTI: used during heap iteration
267
268 NOT_PRODUCT(int _verify_count;) // to avoid redundant verifies
269
270 // Method array.
271 Array<Method*>* _methods;
272 // Interface (Klass*s) this class declares locally to implement.
273 Array<Klass*>* _local_interfaces;
274 // Interface (Klass*s) this class implements transitively.
275 Array<Klass*>* _transitive_interfaces;
276 // Int array containing the original order of method in the class file (for JVMTI).
277 Array<int>* _method_ordering;
278 // Instance and static variable information, starts with 6-tuples of shorts
279 // [access, name index, sig index, initval index, low_offset, high_offset]
280 // for all fields, followed by the generic signature data at the end of
281 // the array. Only fields with generic signature attributes have the generic
282 // signature data set in the array. The fields array looks like following:
283 //
284 // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
285 // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
286 // ...
287 // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
288 // [generic signature index]
289 // [generic signature index]
290 // ...
291 Array<u2>* _fields;
292
293 // embedded Java vtable follows here
294 // embedded Java itables follows here
295 // embedded static fields follows here
296 // embedded nonstatic oop-map blocks follows here
297 // embedded implementor of this interface follows here
298 // The embedded implementor only exists if the current klass is an
299 // iterface. The possible values of the implementor fall into following
300 // three cases:
301 // NULL: no implementor.
302 // A Klass* that's not itself: one implementor.
303 // Itsef: more than one implementors.
304 // embedded host klass follows here
305 // The embedded host klass only exists in an anonymous class for
306 // dynamic language support (JSR 292 enabled). The host class grants
307 // its access privileges to this class also. The host class is either
308 // named, or a previously loaded anonymous class. A non-anonymous class
309 // or an anonymous class loaded through normal classloading does not
310 // have this embedded field.
311 //
312
313 friend class SystemDictionary;
314
315 public:
316 bool has_nonstatic_fields() const {
317 return (_misc_flags & _misc_has_nonstatic_fields) != 0;
318 }
319 void set_has_nonstatic_fields(bool b) {
320 if (b) {
321 _misc_flags |= _misc_has_nonstatic_fields;
322 } else {
323 _misc_flags &= ~_misc_has_nonstatic_fields;
324 }
325 }
326
327 // field sizes
328 int nonstatic_field_size() const { return _nonstatic_field_size; }
329 void set_nonstatic_field_size(int size) { _nonstatic_field_size = size; }
330
331 int static_field_size() const { return _static_field_size; }
332 void set_static_field_size(int size) { _static_field_size = size; }
333
334 int static_oop_field_count() const { return (int)_static_oop_field_count; }
335 void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
336
337 // Java vtable
338 int vtable_length() const { return _vtable_len; }
339 void set_vtable_length(int len) { _vtable_len = len; }
340
341 // Java itable
342 int itable_length() const { return _itable_len; }
343 void set_itable_length(int len) { _itable_len = len; }
344
345 // array klasses
346 Klass* array_klasses() const { return _array_klasses; }
347 void set_array_klasses(Klass* k) { _array_klasses = k; }
348
349 // methods
350 Array<Method*>* methods() const { return _methods; }
351 void set_methods(Array<Method*>* a) { _methods = a; }
352 Method* method_with_idnum(int idnum);
353
354 // method ordering
355 Array<int>* method_ordering() const { return _method_ordering; }
356 void set_method_ordering(Array<int>* m) { _method_ordering = m; }
357 void copy_method_ordering(intArray* m, TRAPS);
358
359 // interfaces
360 Array<Klass*>* local_interfaces() const { return _local_interfaces; }
361 void set_local_interfaces(Array<Klass*>* a) {
362 guarantee(_local_interfaces == NULL || a == NULL, "Just checking");
363 _local_interfaces = a; }
364
365 Array<Klass*>* transitive_interfaces() const { return _transitive_interfaces; }
366 void set_transitive_interfaces(Array<Klass*>* a) {
367 guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");
368 _transitive_interfaces = a;
369 }
370
371 private:
372 friend class fieldDescriptor;
373 FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
374
375 public:
376 int field_offset (int index) const { return field(index)->offset(); }
377 int field_access_flags(int index) const { return field(index)->access_flags(); }
378 Symbol* field_name (int index) const { return field(index)->name(constants()); }
379 Symbol* field_signature (int index) const { return field(index)->signature(constants()); }
380
381 // Number of Java declared fields
382 int java_fields_count() const { return (int)_java_fields_count; }
383
384 Array<u2>* fields() const { return _fields; }
385 void set_fields(Array<u2>* f, u2 java_fields_count) {
386 guarantee(_fields == NULL || f == NULL, "Just checking");
387 _fields = f;
388 _java_fields_count = java_fields_count;
389 }
390
391 // inner classes
392 Array<u2>* inner_classes() const { return _inner_classes; }
393 void set_inner_classes(Array<u2>* f) { _inner_classes = f; }
394
395 enum InnerClassAttributeOffset {
396 // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
397 inner_class_inner_class_info_offset = 0,
398 inner_class_outer_class_info_offset = 1,
399 inner_class_inner_name_offset = 2,
400 inner_class_access_flags_offset = 3,
401 inner_class_next_offset = 4
402 };
403
404 enum EnclosingMethodAttributeOffset {
405 enclosing_method_class_index_offset = 0,
406 enclosing_method_method_index_offset = 1,
407 enclosing_method_attribute_size = 2
408 };
409
410 // method override check
411 bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
412
413 // package
414 bool is_same_class_package(Klass* class2);
415 bool is_same_class_package(oop classloader2, Symbol* classname2);
416 static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
417
418 // find an enclosing class (defined where original code was, in jvm.cpp!)
419 Klass* compute_enclosing_class(bool* inner_is_member, TRAPS) {
420 instanceKlassHandle self(THREAD, this);
421 return compute_enclosing_class_impl(self, inner_is_member, THREAD);
422 }
423 static Klass* compute_enclosing_class_impl(instanceKlassHandle self,
424 bool* inner_is_member, TRAPS);
425
426 // tell if two classes have the same enclosing class (at package level)
427 bool is_same_package_member(Klass* class2, TRAPS) {
428 instanceKlassHandle self(THREAD, this);
429 return is_same_package_member_impl(self, class2, THREAD);
430 }
431 static bool is_same_package_member_impl(instanceKlassHandle self,
432 Klass* class2, TRAPS);
433
434 // initialization state
435 bool is_loaded() const { return _init_state >= loaded; }
436 bool is_linked() const { return _init_state >= linked; }
437 bool is_initialized() const { return _init_state == fully_initialized; }
438 bool is_not_initialized() const { return _init_state < being_initialized; }
439 bool is_being_initialized() const { return _init_state == being_initialized; }
440 bool is_in_error_state() const { return _init_state == initialization_error; }
441 bool is_reentrant_initialization(Thread *thread) { return thread == _init_thread; }
442 ClassState init_state() { return (ClassState)_init_state; }
443 bool is_rewritten() const { return (_misc_flags & _misc_rewritten) != 0; }
444
445 // defineClass specified verification
446 bool should_verify_class() const {
447 return (_misc_flags & _misc_should_verify_class) != 0;
448 }
449 void set_should_verify_class(bool value) {
450 if (value) {
451 _misc_flags |= _misc_should_verify_class;
452 } else {
453 _misc_flags &= ~_misc_should_verify_class;
454 }
455 }
456
457 // marking
458 bool is_marked_dependent() const { return _is_marked_dependent; }
459 void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
460
461 // initialization (virtuals from Klass)
462 bool should_be_initialized() const; // means that initialize should be called
463 void initialize(TRAPS);
464 void link_class(TRAPS);
465 bool link_class_or_fail(TRAPS); // returns false on failure
466 void unlink_class();
467 void rewrite_class(TRAPS);
468 void link_methods(TRAPS);
469 Method* class_initializer();
470
471 // set the class to initialized if no static initializer is present
472 void eager_initialize(Thread *thread);
473
474 // reference type
475 ReferenceType reference_type() const { return (ReferenceType)_reference_type; }
476 void set_reference_type(ReferenceType t) {
477 assert(t == (u1)t, "overflow");
478 _reference_type = (u1)t;
479 }
480
481 static ByteSize reference_type_offset() { return in_ByteSize(offset_of(InstanceKlass, _reference_type)); }
482
483 // find local field, returns true if found
484 bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
485 // find field in direct superinterfaces, returns the interface in which the field is defined
486 Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
487 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
488 Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
489 // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
490 Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
491
492 // find a non-static or static field given its offset within the class.
493 bool contains_field_offset(int offset) {
494 return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
495 }
496
497 bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
498 bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
499
500 // find a local method (returns NULL if not found)
501 Method* find_method(Symbol* name, Symbol* signature) const;
502 static Method* find_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
503
504 // lookup operation (returns NULL if not found)
505 Method* uncached_lookup_method(Symbol* name, Symbol* signature) const;
506
507 // lookup a method in all the interfaces that this class implements
508 // (returns NULL if not found)
509 Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature) const;
510
511 // Find method indices by name. If a method with the specified name is
512 // found the index to the first method is returned, and 'end' is filled in
513 // with the index of first non-name-matching method. If no method is found
514 // -1 is returned.
515 int find_method_by_name(Symbol* name, int* end);
516 static int find_method_by_name(Array<Method*>* methods, Symbol* name, int* end);
517
518 // constant pool
519 ConstantPool* constants() const { return _constants; }
520 void set_constants(ConstantPool* c) { _constants = c; }
521
522 // protection domain
523 oop protection_domain() const;
524
525 // signers
526 objArrayOop signers() const;
527
528 // host class
529 Klass* host_klass() const {
530 Klass** hk = (Klass**)adr_host_klass();
531 if (hk == NULL) {
532 return NULL;
533 } else {
534 return *hk;
535 }
536 }
537 void set_host_klass(Klass* host) {
538 assert(is_anonymous(), "not anonymous");
539 Klass** addr = (Klass**)adr_host_klass();
540 assert(addr != NULL, "no reversed space");
541 if (addr != NULL) {
542 *addr = host;
543 }
544 }
545 bool is_anonymous() const {
546 return (_misc_flags & _misc_is_anonymous) != 0;
547 }
548 void set_is_anonymous(bool value) {
549 if (value) {
550 _misc_flags |= _misc_is_anonymous;
551 } else {
552 _misc_flags &= ~_misc_is_anonymous;
553 }
554 }
555
556 // Oop that keeps the metadata for this class from being unloaded
557 // in places where the metadata is stored in other places, like nmethods
558 oop klass_holder() const {
559 return is_anonymous() ? java_mirror() : class_loader();
560 }
561
562 bool is_contended() const {
563 return (_misc_flags & _misc_is_contended) != 0;
564 }
565 void set_is_contended(bool value) {
566 if (value) {
567 _misc_flags |= _misc_is_contended;
568 } else {
569 _misc_flags &= ~_misc_is_contended;
570 }
571 }
572
573 // source file name
574 Symbol* source_file_name() const {
575 return (_source_file_name_index == 0) ?
576 (Symbol*)NULL : _constants->symbol_at(_source_file_name_index);
577 }
578 u2 source_file_name_index() const {
579 return _source_file_name_index;
580 }
581 void set_source_file_name_index(u2 sourcefile_index) {
582 _source_file_name_index = sourcefile_index;
583 }
584
585 // minor and major version numbers of class file
586 u2 minor_version() const { return _minor_version; }
587 void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
588 u2 major_version() const { return _major_version; }
589 void set_major_version(u2 major_version) { _major_version = major_version; }
590
591 // source debug extension
592 char* source_debug_extension() const { return _source_debug_extension; }
593 void set_source_debug_extension(char* array, int length);
594
595 // symbol unloading support (refcount already added)
596 Symbol* array_name() { return _array_name; }
597 void set_array_name(Symbol* name) { assert(_array_name == NULL || name == NULL, "name already created"); _array_name = name; }
598
599 // nonstatic oop-map blocks
600 static int nonstatic_oop_map_size(unsigned int oop_map_count) {
601 return oop_map_count * OopMapBlock::size_in_words();
602 }
603 unsigned int nonstatic_oop_map_count() const {
604 return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
605 }
606 int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
607 void set_nonstatic_oop_map_size(int words) {
608 _nonstatic_oop_map_size = words;
609 }
610
611 // RedefineClasses() support for previous versions:
612 void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
613 int emcp_method_count);
614 // If the _previous_versions array is non-NULL, then this klass
615 // has been redefined at least once even if we aren't currently
616 // tracking a previous version.
617 bool has_been_redefined() const { return _previous_versions != NULL; }
618 bool has_previous_version() const;
619 void init_previous_versions() {
620 _previous_versions = NULL;
621 }
622 GrowableArray<PreviousVersionNode *>* previous_versions() const {
623 return _previous_versions;
624 }
625
626 static void purge_previous_versions(InstanceKlass* ik);
627
628 // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
629 void set_cached_class_file(JvmtiCachedClassFileData *data) {
630 _cached_class_file = data;
631 }
632 JvmtiCachedClassFileData * get_cached_class_file() { return _cached_class_file; }
633 jint get_cached_class_file_len();
634 unsigned char * get_cached_class_file_bytes();
635
636 // JVMTI: Support for caching of field indices, types, and offsets
637 void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
638 _jvmti_cached_class_field_map = descriptor;
639 }
640 JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
641 return _jvmti_cached_class_field_map;
642 }
643
644 bool has_default_methods() const {
645 return (_misc_flags & _misc_has_default_methods) != 0;
646 }
647 void set_has_default_methods(bool b) {
648 if (b) {
649 _misc_flags |= _misc_has_default_methods;
650 } else {
651 _misc_flags &= ~_misc_has_default_methods;
652 }
653 }
654
655 // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
656 inline u2 next_method_idnum();
657 void set_initial_method_idnum(u2 value) { _idnum_allocated_count = value; }
658
659 // generics support
660 Symbol* generic_signature() const {
661 return (_generic_signature_index == 0) ?
662 (Symbol*)NULL : _constants->symbol_at(_generic_signature_index);
663 }
664 u2 generic_signature_index() const {
665 return _generic_signature_index;
666 }
667 void set_generic_signature_index(u2 sig_index) {
668 _generic_signature_index = sig_index;
669 }
670
671 u2 enclosing_method_data(int offset);
672 u2 enclosing_method_class_index() {
673 return enclosing_method_data(enclosing_method_class_index_offset);
674 }
675 u2 enclosing_method_method_index() {
676 return enclosing_method_data(enclosing_method_method_index_offset);
677 }
678 void set_enclosing_method_indices(u2 class_index,
679 u2 method_index);
680
681 // jmethodID support
682 static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
683 methodHandle method_h);
684 static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
685 size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
686 jmethodID* to_dealloc_id_p,
687 jmethodID** to_dealloc_jmeths_p);
688 static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
689 size_t *length_p, jmethodID* id_p);
690 jmethodID jmethod_id_or_null(Method* method);
691
692 // annotations support
693 Annotations* annotations() const { return _annotations; }
694 void set_annotations(Annotations* anno) { _annotations = anno; }
695
696 AnnotationArray* class_annotations() const {
697 return (_annotations != NULL) ? _annotations->class_annotations() : NULL;
698 }
699 Array<AnnotationArray*>* fields_annotations() const {
700 return (_annotations != NULL) ? _annotations->fields_annotations() : NULL;
701 }
702 AnnotationArray* class_type_annotations() const {
703 return (_annotations != NULL) ? _annotations->class_type_annotations() : NULL;
704 }
705 Array<AnnotationArray*>* fields_type_annotations() const {
706 return (_annotations != NULL) ? _annotations->fields_type_annotations() : NULL;
707 }
708 // allocation
709 instanceOop allocate_instance(TRAPS);
710
711 // additional member function to return a handle
712 instanceHandle allocate_instance_handle(TRAPS) { return instanceHandle(THREAD, allocate_instance(THREAD)); }
713
714 objArrayOop allocate_objArray(int n, int length, TRAPS);
715 // Helper function
716 static instanceOop register_finalizer(instanceOop i, TRAPS);
717
718 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
719 // if not, throw either an Error or an Exception.
720 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
721
722 // initialization
723 void call_class_initializer(TRAPS);
724 void set_initialization_state_and_notify(ClassState state, TRAPS);
725
726 // OopMapCache support
727 OopMapCache* oop_map_cache() { return _oop_map_cache; }
728 void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
729 void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
730
731 // JNI identifier support (for static fields - for jni performance)
732 JNIid* jni_ids() { return _jni_ids; }
733 void set_jni_ids(JNIid* ids) { _jni_ids = ids; }
734 JNIid* jni_id_for(int offset);
735
736 // maintenance of deoptimization dependencies
737 int mark_dependent_nmethods(DepChange& changes);
738 void add_dependent_nmethod(nmethod* nm);
739 void remove_dependent_nmethod(nmethod* nm);
740
741 // On-stack replacement support
742 nmethod* osr_nmethods_head() const { return _osr_nmethods_head; };
743 void set_osr_nmethods_head(nmethod* h) { _osr_nmethods_head = h; };
744 void add_osr_nmethod(nmethod* n);
745 void remove_osr_nmethod(nmethod* n);
746 nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
747
748 // Breakpoint support (see methods on Method* for details)
749 BreakpointInfo* breakpoints() const { return _breakpoints; };
750 void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
751
752 // support for stub routines
753 static ByteSize init_state_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_state)); }
754 TRACE_DEFINE_OFFSET;
755 static ByteSize init_thread_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_thread)); }
756
757 // subclass/subinterface checks
758 bool implements_interface(Klass* k) const;
759
760 // Access to the implementor of an interface.
761 Klass* implementor() const
762 {
763 Klass** k = adr_implementor();
764 if (k == NULL) {
765 return NULL;
766 } else {
767 return *k;
768 }
769 }
770
771 void set_implementor(Klass* k) {
772 assert(is_interface(), "not interface");
773 Klass** addr = adr_implementor();
774 assert(addr != NULL, "null addr");
775 if (addr != NULL) {
776 *addr = k;
777 }
778 }
779
780 int nof_implementors() const {
781 Klass* k = implementor();
782 if (k == NULL) {
783 return 0;
784 } else if (k != this) {
785 return 1;
786 } else {
787 return 2;
788 }
789 }
790
791 void add_implementor(Klass* k); // k is a new class that implements this interface
792 void init_implementor(); // initialize
793
794 // link this class into the implementors list of every interface it implements
795 void process_interfaces(Thread *thread);
796
797 // virtual operations from Klass
798 bool is_leaf_class() const { return _subklass == NULL; }
799 GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
800 bool compute_is_subtype_of(Klass* k);
801 bool can_be_primary_super_slow() const;
802 int oop_size(oop obj) const { return size_helper(); }
803 bool oop_is_instance_slow() const { return true; }
804
805 // Iterators
806 void do_local_static_fields(FieldClosure* cl);
807 void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
808 void do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS);
809
810 void methods_do(void f(Method* method));
811 void array_klasses_do(void f(Klass* k));
812 void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
813 bool super_types_do(SuperTypeClosure* blk);
814
815 // Casting from Klass*
816 static InstanceKlass* cast(Klass* k) {
817 assert(k->is_klass(), "must be");
818 assert(k->oop_is_instance(), "cast to InstanceKlass");
819 return (InstanceKlass*) k;
820 }
821
822 InstanceKlass* java_super() const {
823 return (super() == NULL) ? NULL : cast(super());
824 }
825
826 // Sizing (in words)
827 static int header_size() { return align_object_offset(sizeof(InstanceKlass)/HeapWordSize); }
828
829 static int size(int vtable_length, int itable_length,
830 int nonstatic_oop_map_size,
831 bool is_interface, bool is_anonymous) {
832 return align_object_size(header_size() +
833 align_object_offset(vtable_length) +
834 align_object_offset(itable_length) +
835 ((is_interface || is_anonymous) ?
836 align_object_offset(nonstatic_oop_map_size) :
837 nonstatic_oop_map_size) +
838 (is_interface ? (int)sizeof(Klass*)/HeapWordSize : 0) +
839 (is_anonymous ? (int)sizeof(Klass*)/HeapWordSize : 0));
840 }
841 int size() const { return size(vtable_length(),
842 itable_length(),
843 nonstatic_oop_map_size(),
844 is_interface(),
845 is_anonymous());
846 }
847 #if INCLUDE_SERVICES
848 virtual void collect_statistics(KlassSizeStats *sz) const;
849 #endif
850
851 static int vtable_start_offset() { return header_size(); }
852 static int vtable_length_offset() { return offset_of(InstanceKlass, _vtable_len) / HeapWordSize; }
853
854 intptr_t* start_of_vtable() const { return ((intptr_t*)this) + vtable_start_offset(); }
855 intptr_t* start_of_itable() const { return start_of_vtable() + align_object_offset(vtable_length()); }
856 int itable_offset_in_words() const { return start_of_itable() - (intptr_t*)this; }
857
858 intptr_t* end_of_itable() const { return start_of_itable() + itable_length(); }
859
860 address static_field_addr(int offset);
861
862 OopMapBlock* start_of_nonstatic_oop_maps() const {
863 return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
864 }
865
866 Klass** end_of_nonstatic_oop_maps() const {
867 return (Klass**)(start_of_nonstatic_oop_maps() +
868 nonstatic_oop_map_count());
869 }
870
871 Klass** adr_implementor() const {
872 if (is_interface()) {
873 return (Klass**)end_of_nonstatic_oop_maps();
874 } else {
875 return NULL;
876 }
877 };
878
879 Klass** adr_host_klass() const {
880 if (is_anonymous()) {
881 Klass** adr_impl = adr_implementor();
882 if (adr_impl != NULL) {
883 return adr_impl + 1;
884 } else {
885 return end_of_nonstatic_oop_maps();
886 }
887 } else {
888 return NULL;
889 }
890 }
891
892 // Use this to return the size of an instance in heap words:
893 int size_helper() const {
894 return layout_helper_to_size_helper(layout_helper());
895 }
896
897 // This bit is initialized in classFileParser.cpp.
898 // It is false under any of the following conditions:
899 // - the class is abstract (including any interface)
900 // - the class has a finalizer (if !RegisterFinalizersAtInit)
901 // - the class size is larger than FastAllocateSizeLimit
902 // - the class is java/lang/Class, which cannot be allocated directly
903 bool can_be_fastpath_allocated() const {
904 return !layout_helper_needs_slow_path(layout_helper());
905 }
906
907 // Java vtable/itable
908 klassVtable* vtable() const; // return new klassVtable wrapper
909 inline Method* method_at_vtable(int index);
910 klassItable* itable() const; // return new klassItable wrapper
911 Method* method_at_itable(Klass* holder, int index, TRAPS);
912
913 // Garbage collection
914 void oop_follow_contents(oop obj);
915 int oop_adjust_pointers(oop obj);
916
917 void clean_implementors_list(BoolObjectClosure* is_alive);
918 void clean_method_data(BoolObjectClosure* is_alive);
919
920 // Explicit metaspace deallocation of fields
921 // For RedefineClasses and class file parsing errors, we need to deallocate
922 // instanceKlasses and the metadata they point to.
923 void deallocate_contents(ClassLoaderData* loader_data);
924 static void deallocate_methods(ClassLoaderData* loader_data,
925 Array<Method*>* methods);
926 void static deallocate_interfaces(ClassLoaderData* loader_data,
927 Klass* super_klass,
928 Array<Klass*>* local_interfaces,
929 Array<Klass*>* transitive_interfaces);
930
931 // The constant pool is on stack if any of the methods are executing or
932 // referenced by handles.
933 bool on_stack() const { return _constants->on_stack(); }
934
935 // callbacks for actions during class unloading
936 static void notify_unload_class(InstanceKlass* ik);
937 static void release_C_heap_structures(InstanceKlass* ik);
938
939 // Parallel Scavenge and Parallel Old
940 PARALLEL_GC_DECLS
941
942 // Naming
943 const char* signature_name() const;
944
945 // Iterators
946 int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) {
947 return oop_oop_iterate_v(obj, blk);
948 }
949
950 int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) {
951 return oop_oop_iterate_v_m(obj, blk, mr);
952 }
953
954 #define InstanceKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
955 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \
956 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, \
957 MemRegion mr);
958
959 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DECL)
960 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DECL)
961
962 #if INCLUDE_ALL_GCS
963 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
964 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
965
966 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
967 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
968 #endif // INCLUDE_ALL_GCS
969
970 u2 idnum_allocated_count() const { return _idnum_allocated_count; }
971
972 private:
973 // initialization state
974 #ifdef ASSERT
975 void set_init_state(ClassState state);
976 #else
977 void set_init_state(ClassState state) { _init_state = (u1)state; }
978 #endif
979 void set_rewritten() { _misc_flags |= _misc_rewritten; }
980 void set_init_thread(Thread *thread) { _init_thread = thread; }
981
982 // The RedefineClasses() API can cause new method idnums to be needed
983 // which will cause the caches to grow. Safety requires different
984 // cache management logic if the caches can grow instead of just
985 // going from NULL to non-NULL.
986 bool idnum_can_increment() const { return has_been_redefined(); }
987 jmethodID* methods_jmethod_ids_acquire() const
988 { return (jmethodID*)OrderAccess::load_ptr_acquire(&_methods_jmethod_ids); }
989 void release_set_methods_jmethod_ids(jmethodID* jmeths)
990 { OrderAccess::release_store_ptr(&_methods_jmethod_ids, jmeths); }
991
992 // Lock during initialization
993 public:
994 // Lock for (1) initialization; (2) access to the ConstantPool of this class.
995 // Must be one per class and it has to be a VM internal object so java code
996 // cannot lock it (like the mirror).
997 // It has to be an object not a Mutex because it's held through java calls.
998 volatile oop init_lock() const;
999 private:
1000
1001 // Static methods that are used to implement member methods where an exposed this pointer
1002 // is needed due to possible GCs
1003 static bool link_class_impl (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
1004 static bool verify_code (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
1005 static void initialize_impl (instanceKlassHandle this_oop, TRAPS);
1006 static void eager_initialize_impl (instanceKlassHandle this_oop);
1007 static void set_initialization_state_and_notify_impl (instanceKlassHandle this_oop, ClassState state, TRAPS);
1008 static void call_class_initializer_impl (instanceKlassHandle this_oop, TRAPS);
1009 static Klass* array_klass_impl (instanceKlassHandle this_oop, bool or_null, int n, TRAPS);
1010 static void do_local_static_fields_impl (instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS);
1011 /* jni_id_for_impl for jfieldID only */
1012 static JNIid* jni_id_for_impl (instanceKlassHandle this_oop, int offset);
1013
1014 // Returns the array class for the n'th dimension
1015 Klass* array_klass_impl(bool or_null, int n, TRAPS);
1016
1017 // Returns the array class with this class as element type
1018 Klass* array_klass_impl(bool or_null, TRAPS);
1019
1020 // Free CHeap allocated fields.
1021 void release_C_heap_structures();
1022 public:
1023 // CDS support - remove and restore oops from metadata. Oops are not shared.
1024 virtual void remove_unshareable_info();
1025 virtual void restore_unshareable_info(TRAPS);
1026
1027 // jvm support
1028 jint compute_modifier_flags(TRAPS) const;
1029
1030 // JSR-292 support
1031 MemberNameTable* member_names() { return _member_names; }
1032 void set_member_names(MemberNameTable* member_names) { _member_names = member_names; }
1033 void add_member_name(int index, Handle member_name);
1034 oop get_member_name(int index);
1035
1036 public:
1037 // JVMTI support
1038 jint jvmti_class_status() const;
1039
1040 public:
1041 // Printing
1042 #ifndef PRODUCT
1043 void print_on(outputStream* st) const;
1044 #endif
1045 void print_value_on(outputStream* st) const;
1046
1047 void oop_print_value_on(oop obj, outputStream* st);
1048
1049 #ifndef PRODUCT
1050 void oop_print_on (oop obj, outputStream* st);
1051
1052 void print_dependent_nmethods(bool verbose = false);
1053 bool is_dependent_nmethod(nmethod* nm);
1054 #endif
1055
1056 const char* internal_name() const;
1057
1058 // Verification
1059 void verify_on(outputStream* st, bool check_dictionary);
1060
1061 void oop_verify_on(oop obj, outputStream* st);
1062 };
1063
1064 inline Method* InstanceKlass::method_at_vtable(int index) {
1065 #ifndef PRODUCT
1066 assert(index >= 0, "valid vtable index");
1067 if (DebugVtables) {
1068 verify_vtable_index(index);
1069 }
1070 #endif
1071 vtableEntry* ve = (vtableEntry*)start_of_vtable();
1072 return ve[index].method();
1073 }
1074
1075 // for adding methods
1076 // UNSET_IDNUM return means no more ids available
1077 inline u2 InstanceKlass::next_method_idnum() {
1078 if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1079 return ConstMethod::UNSET_IDNUM; // no more ids available
1080 } else {
1081 return _idnum_allocated_count++;
1082 }
1083 }
1084
1085
1086 /* JNIid class for jfieldIDs only */
1087 class JNIid: public CHeapObj<mtClass> {
1088 friend class VMStructs;
1089 private:
1090 Klass* _holder;
1091 JNIid* _next;
1092 int _offset;
1093 #ifdef ASSERT
1094 bool _is_static_field_id;
1095 #endif
1096
1097 public:
1098 // Accessors
1099 Klass* holder() const { return _holder; }
1100 int offset() const { return _offset; }
1101 JNIid* next() { return _next; }
1102 // Constructor
1103 JNIid(Klass* holder, int offset, JNIid* next);
1104 // Identifier lookup
1105 JNIid* find(int offset);
1106
1107 bool find_local_field(fieldDescriptor* fd) {
1108 return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1109 }
1110
1111 static void deallocate(JNIid* id);
1112 // Debugging
1113 #ifdef ASSERT
1114 bool is_static_field_id() const { return _is_static_field_id; }
1115 void set_is_static_field_id() { _is_static_field_id = true; }
1116 #endif
1117 void verify(Klass* holder);
1118 };
1119
1120
1121 // If breakpoints are more numerous than just JVMTI breakpoints,
1122 // consider compressing this data structure.
1123 // It is currently a simple linked list defined in method.hpp.
1124
1125 class BreakpointInfo;
1126
1127
1128 // A collection point for interesting information about the previous
1129 // version(s) of an InstanceKlass. This class uses weak references to
1130 // the information so that the information may be collected as needed
1131 // by the system. If the information is shared, then a regular
1132 // reference must be used because a weak reference would be seen as
1133 // collectible. A GrowableArray of PreviousVersionNodes is attached
1134 // to the InstanceKlass as needed. See PreviousVersionWalker below.
1135 class PreviousVersionNode : public CHeapObj<mtClass> {
1136 private:
1137 // A shared ConstantPool is never collected so we'll always have
1138 // a reference to it so we can update items in the cache. We'll
1139 // have a weak reference to a non-shared ConstantPool until all
1140 // of the methods (EMCP or obsolete) have been collected; the
1141 // non-shared ConstantPool becomes collectible at that point.
1142 ConstantPool* _prev_constant_pool; // regular or weak reference
1143 bool _prev_cp_is_weak; // true if not a shared ConstantPool
1144
1145 // If the previous version of the InstanceKlass doesn't have any
1146 // EMCP methods, then _prev_EMCP_methods will be NULL. If all the
1147 // EMCP methods have been collected, then _prev_EMCP_methods can
1148 // have a length of zero.
1149 GrowableArray<Method*>* _prev_EMCP_methods;
1150
1151 public:
1152 PreviousVersionNode(ConstantPool* prev_constant_pool, bool prev_cp_is_weak,
1153 GrowableArray<Method*>* prev_EMCP_methods);
1154 ~PreviousVersionNode();
1155 ConstantPool* prev_constant_pool() const {
1156 return _prev_constant_pool;
1157 }
1158 GrowableArray<Method*>* prev_EMCP_methods() const {
1159 return _prev_EMCP_methods;
1160 }
1161 };
1162
1163
1164 // A Handle-ized version of PreviousVersionNode.
1165 class PreviousVersionInfo : public ResourceObj {
1166 private:
1167 constantPoolHandle _prev_constant_pool_handle;
1168 // If the previous version of the InstanceKlass doesn't have any
1169 // EMCP methods, then _prev_EMCP_methods will be NULL. Since the
1170 // methods cannot be collected while we hold a handle,
1171 // _prev_EMCP_methods should never have a length of zero.
1172 GrowableArray<methodHandle>* _prev_EMCP_method_handles;
1173
1174 public:
1175 PreviousVersionInfo(PreviousVersionNode *pv_node);
1176 ~PreviousVersionInfo();
1177 constantPoolHandle prev_constant_pool_handle() const {
1178 return _prev_constant_pool_handle;
1179 }
1180 GrowableArray<methodHandle>* prev_EMCP_method_handles() const {
1181 return _prev_EMCP_method_handles;
1182 }
1183 };
1184
1185
1186 // Helper object for walking previous versions. This helper cleans up
1187 // the Handles that it allocates when the helper object is destroyed.
1188 // The PreviousVersionInfo object returned by next_previous_version()
1189 // is only valid until a subsequent call to next_previous_version() or
1190 // the helper object is destroyed.
1191 class PreviousVersionWalker : public StackObj {
1192 private:
1193 GrowableArray<PreviousVersionNode *>* _previous_versions;
1194 int _current_index;
1195 // Fields for cleaning up when we are done walking the previous versions:
1196 // A HandleMark for the PreviousVersionInfo handles:
1197 HandleMark _hm;
1198
1199 // It would be nice to have a ResourceMark field in this helper also,
1200 // but the ResourceMark code says to be careful to delete handles held
1201 // in GrowableArrays _before_ deleting the GrowableArray. Since we
1202 // can't guarantee the order in which the fields are destroyed, we
1203 // have to let the creator of the PreviousVersionWalker object do
1204 // the right thing. Also, adding a ResourceMark here causes an
1205 // include loop.
1206
1207 // A pointer to the current info object so we can handle the deletes.
1208 PreviousVersionInfo * _current_p;
1209
1210 public:
1211 PreviousVersionWalker(InstanceKlass *ik);
1212 ~PreviousVersionWalker();
1213
1214 // Return the interesting information for the next previous version
1215 // of the klass. Returns NULL if there are no more previous versions.
1216 PreviousVersionInfo* next_previous_version();
1217 };
1218
1219
1220 //
1221 // nmethodBucket is used to record dependent nmethods for
1222 // deoptimization. nmethod dependencies are actually <klass, method>
1223 // pairs but we really only care about the klass part for purposes of
1224 // finding nmethods which might need to be deoptimized. Instead of
1225 // recording the method, a count of how many times a particular nmethod
1226 // was recorded is kept. This ensures that any recording errors are
1227 // noticed since an nmethod should be removed as many times are it's
1228 // added.
1229 //
1230 class nmethodBucket: public CHeapObj<mtClass> {
1231 friend class VMStructs;
1232 private:
1233 nmethod* _nmethod;
1234 int _count;
1235 nmethodBucket* _next;
1236
1237 public:
1238 nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
1239 _nmethod = nmethod;
1240 _next = next;
1241 _count = 1;
1242 }
1243 int count() { return _count; }
1244 int increment() { _count += 1; return _count; }
1245 int decrement() { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
1246 nmethodBucket* next() { return _next; }
1247 void set_next(nmethodBucket* b) { _next = b; }
1248 nmethod* get_nmethod() { return _nmethod; }
1249 };
1250
1251 // An iterator that's used to access the inner classes indices in the
1252 // InstanceKlass::_inner_classes array.
1253 class InnerClassesIterator : public StackObj {
1254 private:
1255 Array<jushort>* _inner_classes;
1256 int _length;
1257 int _idx;
1258 public:
1259
1260 InnerClassesIterator(instanceKlassHandle k) {
1261 _inner_classes = k->inner_classes();
1262 if (k->inner_classes() != NULL) {
1263 _length = _inner_classes->length();
1264 // The inner class array's length should be the multiple of
1265 // inner_class_next_offset if it only contains the InnerClasses
1266 // attribute data, or it should be
1267 // n*inner_class_next_offset+enclosing_method_attribute_size
1268 // if it also contains the EnclosingMethod data.
1269 assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1270 _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1271 "just checking");
1272 // Remove the enclosing_method portion if exists.
1273 if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1274 _length -= InstanceKlass::enclosing_method_attribute_size;
1275 }
1276 } else {
1277 _length = 0;
1278 }
1279 _idx = 0;
1280 }
1281
1282 int length() const {
1283 return _length;
1284 }
1285
1286 void next() {
1287 _idx += InstanceKlass::inner_class_next_offset;
1288 }
1289
1290 bool done() const {
1291 return (_idx >= _length);
1292 }
1293
1294 u2 inner_class_info_index() const {
1295 return _inner_classes->at(
1296 _idx + InstanceKlass::inner_class_inner_class_info_offset);
1297 }
1298
1299 void set_inner_class_info_index(u2 index) {
1300 _inner_classes->at_put(
1301 _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1302 }
1303
1304 u2 outer_class_info_index() const {
1305 return _inner_classes->at(
1306 _idx + InstanceKlass::inner_class_outer_class_info_offset);
1307 }
1308
1309 void set_outer_class_info_index(u2 index) {
1310 _inner_classes->at_put(
1311 _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1312 }
1313
1314 u2 inner_name_index() const {
1315 return _inner_classes->at(
1316 _idx + InstanceKlass::inner_class_inner_name_offset);
1317 }
1318
1319 void set_inner_name_index(u2 index) {
1320 _inner_classes->at_put(
1321 _idx + InstanceKlass::inner_class_inner_name_offset, index);
1322 }
1323
1324 u2 inner_access_flags() const {
1325 return _inner_classes->at(
1326 _idx + InstanceKlass::inner_class_access_flags_offset);
1327 }
1328 };
1329
1330 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP