1 /*
2 * Copyright (c) 1997, 2012, 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 "oops/constMethodOop.hpp"
29 #include "oops/constantPoolOop.hpp"
30 #include "oops/fieldInfo.hpp"
31 #include "oops/instanceOop.hpp"
32 #include "oops/klassOop.hpp"
33 #include "oops/klassVtable.hpp"
34 #include "oops/objArrayOop.hpp"
35 #include "runtime/handles.hpp"
36 #include "runtime/os.hpp"
37 #include "utilities/accessFlags.hpp"
38 #include "utilities/bitMap.inline.hpp"
39
40 // An instanceKlass is the VM level representation of a Java class.
41 // It contains all information needed for at class at execution runtime.
42
43 // instanceKlass layout:
44 // [header ] klassOop
45 // [klass pointer ] klassOop
46 // [C++ vtbl pointer ] Klass
47 // [subtype cache ] Klass
48 // [instance size ] Klass
49 // [java mirror ] Klass
50 // [super ] Klass
51 // [access_flags ] Klass
52 // [name ] Klass
53 // [first subklass ] Klass
54 // [next sibling ] Klass
55 // [array klasses ]
56 // [methods ]
57 // [local interfaces ]
58 // [transitive interfaces ]
59 // [fields ]
60 // [constants ]
61 // [class loader ]
62 // [protection domain ]
63 // [signers ]
64 // [source file name ]
65 // [inner classes ]
66 // [static field size ]
67 // [nonstatic field size ]
68 // [static oop fields size ]
69 // [nonstatic oop maps size ]
70 // [has finalize method ]
71 // [deoptimization mark bit ]
72 // [initialization state ]
73 // [initializing thread ]
74 // [Java vtable length ]
75 // [oop map cache (stack maps) ]
76 // [EMBEDDED Java vtable ] size in words = vtable_len
77 // [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
78 // The embedded nonstatic oop-map blocks are short pairs (offset, length)
79 // indicating where oops are located in instances of this klass.
80 // [EMBEDDED implementor of the interface] only exist for interface
81 // [EMBEDDED host klass ] only exist for an anonymous class (JSR 292 enabled)
82
83
84 // forward declaration for class -- see below for definition
85 class SuperTypeClosure;
86 class JNIid;
87 class jniIdMapBase;
88 class BreakpointInfo;
89 class fieldDescriptor;
90 class DepChange;
91 class nmethodBucket;
92 class PreviousVersionNode;
93 class JvmtiCachedClassFieldMap;
94
95 // This is used in iterators below.
96 class FieldClosure: public StackObj {
97 public:
98 virtual void do_field(fieldDescriptor* fd) = 0;
99 };
100
101 #ifndef PRODUCT
102 // Print fields.
103 // If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.
104 class FieldPrinter: public FieldClosure {
105 oop _obj;
106 outputStream* _st;
107 public:
108 FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}
109 void do_field(fieldDescriptor* fd);
110 };
111 #endif // !PRODUCT
112
113 // ValueObjs embedded in klass. Describes where oops are located in instances of
114 // this klass.
115 class OopMapBlock VALUE_OBJ_CLASS_SPEC {
116 public:
117 // Byte offset of the first oop mapped by this block.
118 int offset() const { return _offset; }
119 void set_offset(int offset) { _offset = offset; }
120
121 // Number of oops in this block.
122 uint count() const { return _count; }
123 void set_count(uint count) { _count = count; }
124
125 // sizeof(OopMapBlock) in HeapWords.
126 static const int size_in_words() {
127 return align_size_up(int(sizeof(OopMapBlock)), HeapWordSize) >>
128 LogHeapWordSize;
129 }
130
131 private:
132 int _offset;
133 uint _count;
134 };
135
136 class instanceKlass: public Klass {
137 friend class VMStructs;
138 public:
139 // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
140 // of the class loading & initialization procedure, and the use of the states.
141 enum ClassState {
142 unparsable_by_gc = 0, // object is not yet parsable by gc. Value of _init_state at object allocation.
143 allocated, // allocated (but not yet linked)
144 loaded, // loaded and inserted in class hierarchy (but not linked yet)
145 linked, // successfully linked/verified (but not initialized yet)
146 being_initialized, // currently running class initializer
147 fully_initialized, // initialized (successfull final state)
148 initialization_error // error happened during initialization
149 };
150
151 public:
152 oop* oop_block_beg() const { return adr_array_klasses(); }
153 oop* oop_block_end() const { return adr_methods_default_annotations() + 1; }
154
155 protected:
156 //
157 // The oop block. See comment in klass.hpp before making changes.
158 //
159
160 // Array classes holding elements of this class.
161 klassOop _array_klasses;
162 // Method array.
163 objArrayOop _methods;
164 // Int array containing the original order of method in the class file (for
165 // JVMTI).
166 typeArrayOop _method_ordering;
167 // Interface (klassOops) this class declares locally to implement.
168 objArrayOop _local_interfaces;
169 // Interface (klassOops) this class implements transitively.
170 objArrayOop _transitive_interfaces;
171 // Instance and static variable information, starts with 6-tuples of shorts
172 // [access, name index, sig index, initval index, low_offset, high_offset]
173 // for all fields, followed by the generic signature data at the end of
174 // the array. Only fields with generic signature attributes have the generic
175 // signature data set in the array. The fields array looks like following:
176 //
177 // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
178 // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
179 // ...
180 // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
181 // [generic signature index]
182 // [generic signature index]
183 // ...
184 typeArrayOop _fields;
185 // Constant pool for this class.
186 constantPoolOop _constants;
187 // Class loader used to load this class, NULL if VM loader used.
188 oop _class_loader;
189 // Protection domain.
190 oop _protection_domain;
191 // Class signers.
192 objArrayOop _signers;
193 // The InnerClasses attribute and EnclosingMethod attribute. The
194 // _inner_classes is an array of shorts. If the class has InnerClasses
195 // attribute, then the _inner_classes array begins with 4-tuples of shorts
196 // [inner_class_info_index, outer_class_info_index,
197 // inner_name_index, inner_class_access_flags] for the InnerClasses
198 // attribute. If the EnclosingMethod attribute exists, it occupies the
199 // last two shorts [class_index, method_index] of the array. If only
200 // the InnerClasses attribute exists, the _inner_classes array length is
201 // number_of_inner_classes * 4. If the class has both InnerClasses
202 // and EnclosingMethod attributes the _inner_classes array length is
203 // number_of_inner_classes * 4 + enclosing_method_attribute_size.
204 typeArrayOop _inner_classes;
205 // Annotations for this class, or null if none.
206 typeArrayOop _class_annotations;
207 // Annotation objects (byte arrays) for fields, or null if no annotations.
208 // Indices correspond to entries (not indices) in fields array.
209 objArrayOop _fields_annotations;
210 // Annotation objects (byte arrays) for methods, or null if no annotations.
211 // Index is the idnum, which is initially the same as the methods array index.
212 objArrayOop _methods_annotations;
213 // Annotation objects (byte arrays) for methods' parameters, or null if no
214 // such annotations.
215 // Index is the idnum, which is initially the same as the methods array index.
216 objArrayOop _methods_parameter_annotations;
217 // Annotation objects (byte arrays) for methods' default values, or null if no
218 // such annotations.
219 // Index is the idnum, which is initially the same as the methods array index.
220 objArrayOop _methods_default_annotations;
221
222 //
223 // End of the oop block.
224 //
225
226 // Name of source file containing this klass, NULL if not specified.
227 Symbol* _source_file_name;
228 // the source debug extension for this klass, NULL if not specified.
229 // Specified as UTF-8 string without terminating zero byte in the classfile,
230 // it is stored in the instanceklass as a NULL-terminated UTF-8 string
231 char* _source_debug_extension;
232 // Generic signature, or null if none.
233 Symbol* _generic_signature;
234 // Array name derived from this class which needs unreferencing
235 // if this class is unloaded.
236 Symbol* _array_name;
237
238 // Number of heapOopSize words used by non-static fields in this klass
239 // (including inherited fields but after header_size()).
240 int _nonstatic_field_size;
241 int _static_field_size; // number words used by static fields (oop and non-oop) in this klass
242 u2 _static_oop_field_count;// number of static oop fields in this klass
243 u2 _java_fields_count; // The number of declared Java fields
244 int _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
245
246 bool _is_marked_dependent; // used for marking during flushing and deoptimization
247 enum {
248 _misc_rewritten = 1 << 0, // methods rewritten.
249 _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
250 _misc_should_verify_class = 1 << 2, // allow caching of preverification
251 _misc_is_anonymous = 1 << 3 // has embedded _inner_classes field
252 };
253 u2 _misc_flags;
254 u2 _minor_version; // minor version number of class file
255 u2 _major_version; // major version number of class file
256 Thread* _init_thread; // Pointer to current thread doing initialization (to handle recusive initialization)
257 int _vtable_len; // length of Java vtable (in words)
258 int _itable_len; // length of Java itable (in words)
259 OopMapCache* volatile _oop_map_cache; // OopMapCache for all methods in the klass (allocated lazily)
260 JNIid* _jni_ids; // First JNI identifier for static fields in this class
261 jmethodID* _methods_jmethod_ids; // jmethodIDs corresponding to method_idnum, or NULL if none
262 int* _methods_cached_itable_indices; // itable_index cache for JNI invoke corresponding to methods idnum, or NULL
263 nmethodBucket* _dependencies; // list of dependent nmethods
264 nmethod* _osr_nmethods_head; // Head of list of on-stack replacement nmethods for this class
265 BreakpointInfo* _breakpoints; // bpt lists, managed by methodOop
266 // Array of interesting part(s) of the previous version(s) of this
267 // instanceKlass. See PreviousVersionWalker below.
268 GrowableArray<PreviousVersionNode *>* _previous_versions;
269 // JVMTI fields can be moved to their own structure - see 6315920
270 unsigned char * _cached_class_file_bytes; // JVMTI: cached class file, before retransformable agent modified it in CFLH
271 jint _cached_class_file_len; // JVMTI: length of above
272 JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map; // JVMTI: used during heap iteration
273 volatile u2 _idnum_allocated_count; // JNI/JVMTI: increments with the addition of methods, old ids don't change
274
275 // Class states are defined as ClassState (see above).
276 // Place the _init_state here to utilize the unused 2-byte after
277 // _idnum_allocated_count.
278 u1 _init_state; // state of class
279
280 u1 _reference_type; // reference type
281
282 // embedded Java vtable follows here
283 // embedded Java itables follows here
284 // embedded static fields follows here
285 // embedded nonstatic oop-map blocks follows here
286 // embedded implementor of this interface follows here
287 // The embedded implementor only exists if the current klass is an
288 // iterface. The possible values of the implementor fall into following
289 // three cases:
290 // NULL: no implementor.
291 // A klassOop that's not itself: one implementor.
292 // Itsef: more than one implementors.
293 // embedded host klass follows here
294 // The embedded host klass only exists in an anonymous class for
295 // dynamic language support (JSR 292 enabled). The host class grants
296 // its access privileges to this class also. The host class is either
297 // named, or a previously loaded anonymous class. A non-anonymous class
298 // or an anonymous class loaded through normal classloading does not
299 // have this embedded field.
300 //
301
302 friend class instanceKlassKlass;
303 friend class SystemDictionary;
304
305 public:
306 bool has_nonstatic_fields() const {
307 return (_misc_flags & _misc_has_nonstatic_fields) != 0;
308 }
309 void set_has_nonstatic_fields(bool b) {
310 if (b) {
311 _misc_flags |= _misc_has_nonstatic_fields;
312 } else {
313 _misc_flags &= ~_misc_has_nonstatic_fields;
314 }
315 }
316
317 // field sizes
318 int nonstatic_field_size() const { return _nonstatic_field_size; }
319 void set_nonstatic_field_size(int size) { _nonstatic_field_size = size; }
320
321 int static_field_size() const { return _static_field_size; }
322 void set_static_field_size(int size) { _static_field_size = size; }
323
324 int static_oop_field_count() const { return (int)_static_oop_field_count; }
325 void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
326
327 // Java vtable
328 int vtable_length() const { return _vtable_len; }
329 void set_vtable_length(int len) { _vtable_len = len; }
330
331 // Java itable
332 int itable_length() const { return _itable_len; }
333 void set_itable_length(int len) { _itable_len = len; }
334
335 // array klasses
336 klassOop array_klasses() const { return _array_klasses; }
337 void set_array_klasses(klassOop k) { oop_store_without_check((oop*) &_array_klasses, (oop) k); }
338
339 // methods
340 objArrayOop methods() const { return _methods; }
341 void set_methods(objArrayOop a) { oop_store_without_check((oop*) &_methods, (oop) a); }
342 methodOop method_with_idnum(int idnum);
343
344 // method ordering
345 typeArrayOop method_ordering() const { return _method_ordering; }
346 void set_method_ordering(typeArrayOop m) { oop_store_without_check((oop*) &_method_ordering, (oop) m); }
347
348 // interfaces
349 objArrayOop local_interfaces() const { return _local_interfaces; }
350 void set_local_interfaces(objArrayOop a) { oop_store_without_check((oop*) &_local_interfaces, (oop) a); }
351 objArrayOop transitive_interfaces() const { return _transitive_interfaces; }
352 void set_transitive_interfaces(objArrayOop a) { oop_store_without_check((oop*) &_transitive_interfaces, (oop) a); }
353
354 private:
355 friend class fieldDescriptor;
356 FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
357
358 public:
359 int field_offset (int index) const { return field(index)->offset(); }
360 int field_access_flags(int index) const { return field(index)->access_flags(); }
361 Symbol* field_name (int index) const { return field(index)->name(constants()); }
362 Symbol* field_signature (int index) const { return field(index)->signature(constants()); }
363
364 // Number of Java declared fields
365 int java_fields_count() const { return (int)_java_fields_count; }
366
367 typeArrayOop fields() const { return _fields; }
368
369 void set_fields(typeArrayOop f, u2 java_fields_count) {
370 oop_store_without_check((oop*) &_fields, (oop) f);
371 _java_fields_count = java_fields_count;
372 }
373
374 // inner classes
375 typeArrayOop inner_classes() const { return _inner_classes; }
376 void set_inner_classes(typeArrayOop f) { oop_store_without_check((oop*) &_inner_classes, (oop) f); }
377
378 enum InnerClassAttributeOffset {
379 // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
380 inner_class_inner_class_info_offset = 0,
381 inner_class_outer_class_info_offset = 1,
382 inner_class_inner_name_offset = 2,
383 inner_class_access_flags_offset = 3,
384 inner_class_next_offset = 4
385 };
386
387 enum EnclosingMethodAttributeOffset {
388 enclosing_method_class_index_offset = 0,
389 enclosing_method_method_index_offset = 1,
390 enclosing_method_attribute_size = 2
391 };
392
393 // method override check
394 bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
395
396 // package
397 bool is_same_class_package(klassOop class2);
398 bool is_same_class_package(oop classloader2, Symbol* classname2);
399 static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
400
401 // find an enclosing class (defined where original code was, in jvm.cpp!)
402 klassOop compute_enclosing_class(bool* inner_is_member, TRAPS) {
403 instanceKlassHandle self(THREAD, this->as_klassOop());
404 return compute_enclosing_class_impl(self, inner_is_member, THREAD);
405 }
406 static klassOop compute_enclosing_class_impl(instanceKlassHandle self,
407 bool* inner_is_member, TRAPS);
408
409 // tell if two classes have the same enclosing class (at package level)
410 bool is_same_package_member(klassOop class2, TRAPS) {
411 instanceKlassHandle self(THREAD, this->as_klassOop());
412 return is_same_package_member_impl(self, class2, THREAD);
413 }
414 static bool is_same_package_member_impl(instanceKlassHandle self,
415 klassOop class2, TRAPS);
416
417 // initialization state
418 bool is_loaded() const { return _init_state >= loaded; }
419 bool is_linked() const { return _init_state >= linked; }
420 bool is_initialized() const { return _init_state == fully_initialized; }
421 bool is_not_initialized() const { return _init_state < being_initialized; }
422 bool is_being_initialized() const { return _init_state == being_initialized; }
423 bool is_in_error_state() const { return _init_state == initialization_error; }
424 bool is_reentrant_initialization(Thread *thread) { return thread == _init_thread; }
425 ClassState init_state() { return (ClassState)_init_state; }
426 bool is_rewritten() const { return (_misc_flags & _misc_rewritten) != 0; }
427
428 // defineClass specified verification
429 bool should_verify_class() const {
430 return (_misc_flags & _misc_should_verify_class) != 0;
431 }
432 void set_should_verify_class(bool value) {
433 if (value) {
434 _misc_flags |= _misc_should_verify_class;
435 } else {
436 _misc_flags &= ~_misc_should_verify_class;
437 }
438 }
439
440 // marking
441 bool is_marked_dependent() const { return _is_marked_dependent; }
442 void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
443
444 // initialization (virtuals from Klass)
445 bool should_be_initialized() const; // means that initialize should be called
446 void initialize(TRAPS);
447 void link_class(TRAPS);
448 bool link_class_or_fail(TRAPS); // returns false on failure
449 void unlink_class();
450 void rewrite_class(TRAPS);
451 void relocate_and_link_methods(TRAPS);
452 methodOop class_initializer();
453
454 // set the class to initialized if no static initializer is present
455 void eager_initialize(Thread *thread);
456
457 // reference type
458 ReferenceType reference_type() const { return (ReferenceType)_reference_type; }
459 void set_reference_type(ReferenceType t) {
460 assert(t == (u1)t, "overflow");
461 _reference_type = (u1)t;
462 }
463
464 static ByteSize reference_type_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(instanceKlass, _reference_type)); }
465
466 // find local field, returns true if found
467 bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
468 // find field in direct superinterfaces, returns the interface in which the field is defined
469 klassOop find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
470 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
471 klassOop find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
472 // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
473 klassOop find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
474
475 // find a non-static or static field given its offset within the class.
476 bool contains_field_offset(int offset) {
477 return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
478 }
479
480 bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
481 bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
482
483 // find a local method (returns NULL if not found)
484 methodOop find_method(Symbol* name, Symbol* signature) const;
485 static methodOop find_method(objArrayOop methods, Symbol* name, Symbol* signature);
486
487 // lookup operation (returns NULL if not found)
488 methodOop uncached_lookup_method(Symbol* name, Symbol* signature) const;
489
490 // lookup a method in all the interfaces that this class implements
491 // (returns NULL if not found)
492 methodOop lookup_method_in_all_interfaces(Symbol* name, Symbol* signature) const;
493
494 // constant pool
495 constantPoolOop constants() const { return _constants; }
496 void set_constants(constantPoolOop c) { oop_store_without_check((oop*) &_constants, (oop) c); }
497
498 // class loader
499 oop class_loader() const { return _class_loader; }
500 void set_class_loader(oop l) { oop_store((oop*) &_class_loader, l); }
501
502 // protection domain
503 oop protection_domain() { return _protection_domain; }
504 void set_protection_domain(oop pd) { oop_store((oop*) &_protection_domain, pd); }
505
506 // host class
507 oop host_klass() const {
508 oop* hk = adr_host_klass();
509 if (hk == NULL) {
510 return NULL;
511 } else {
512 return *hk;
513 }
514 }
515 void set_host_klass(oop host) {
516 assert(is_anonymous(), "not anonymous");
517 oop* addr = adr_host_klass();
518 assert(addr != NULL, "no reversed space");
519 oop_store(addr, host);
520 }
521 bool is_anonymous() const {
522 return (_misc_flags & _misc_is_anonymous) != 0;
523 }
524 void set_is_anonymous(bool value) {
525 if (value) {
526 _misc_flags |= _misc_is_anonymous;
527 } else {
528 _misc_flags &= ~_misc_is_anonymous;
529 }
530 }
531
532 // signers
533 objArrayOop signers() const { return _signers; }
534 void set_signers(objArrayOop s) { oop_store((oop*) &_signers, oop(s)); }
535
536 // source file name
537 Symbol* source_file_name() const { return _source_file_name; }
538 void set_source_file_name(Symbol* n);
539
540 // minor and major version numbers of class file
541 u2 minor_version() const { return _minor_version; }
542 void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
543 u2 major_version() const { return _major_version; }
544 void set_major_version(u2 major_version) { _major_version = major_version; }
545
546 // source debug extension
547 char* source_debug_extension() const { return _source_debug_extension; }
548 void set_source_debug_extension(char* array, int length);
549
550 // symbol unloading support (refcount already added)
551 Symbol* array_name() { return _array_name; }
552 void set_array_name(Symbol* name) { assert(_array_name == NULL, "name already created"); _array_name = name; }
553
554 // nonstatic oop-map blocks
555 static int nonstatic_oop_map_size(unsigned int oop_map_count) {
556 return oop_map_count * OopMapBlock::size_in_words();
557 }
558 unsigned int nonstatic_oop_map_count() const {
559 return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
560 }
561 int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
562 void set_nonstatic_oop_map_size(int words) {
563 _nonstatic_oop_map_size = words;
564 }
565
566 // RedefineClasses() support for previous versions:
567 void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
568 int emcp_method_count);
569 // If the _previous_versions array is non-NULL, then this klass
570 // has been redefined at least once even if we aren't currently
571 // tracking a previous version.
572 bool has_been_redefined() const { return _previous_versions != NULL; }
573 bool has_previous_version() const;
574 void init_previous_versions() {
575 _previous_versions = NULL;
576 }
577 GrowableArray<PreviousVersionNode *>* previous_versions() const {
578 return _previous_versions;
579 }
580
581 // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
582 void set_cached_class_file(unsigned char *class_file_bytes,
583 jint class_file_len) { _cached_class_file_len = class_file_len;
584 _cached_class_file_bytes = class_file_bytes; }
585 jint get_cached_class_file_len() { return _cached_class_file_len; }
586 unsigned char * get_cached_class_file_bytes() { return _cached_class_file_bytes; }
587
588 // JVMTI: Support for caching of field indices, types, and offsets
589 void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
590 _jvmti_cached_class_field_map = descriptor;
591 }
592 JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
593 return _jvmti_cached_class_field_map;
594 }
595
596 // for adding methods, constMethodOopDesc::UNSET_IDNUM means no more ids available
597 inline u2 next_method_idnum();
598 void set_initial_method_idnum(u2 value) { _idnum_allocated_count = value; }
599
600 // generics support
601 Symbol* generic_signature() const { return _generic_signature; }
602 void set_generic_signature(Symbol* sig) { _generic_signature = sig; }
603
604 u2 enclosing_method_data(int offset);
605 u2 enclosing_method_class_index() {
606 return enclosing_method_data(enclosing_method_class_index_offset);
607 }
608 u2 enclosing_method_method_index() {
609 return enclosing_method_data(enclosing_method_method_index_offset);
610 }
611 void set_enclosing_method_indices(u2 class_index,
612 u2 method_index);
613
614 // jmethodID support
615 static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
616 methodHandle method_h);
617 static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
618 size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
619 jmethodID* to_dealloc_id_p,
620 jmethodID** to_dealloc_jmeths_p);
621 static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
622 size_t *length_p, jmethodID* id_p);
623 jmethodID jmethod_id_or_null(methodOop method);
624
625 // cached itable index support
626 void set_cached_itable_index(size_t idnum, int index);
627 int cached_itable_index(size_t idnum);
628
629 // annotations support
630 typeArrayOop class_annotations() const { return _class_annotations; }
631 objArrayOop fields_annotations() const { return _fields_annotations; }
632 objArrayOop methods_annotations() const { return _methods_annotations; }
633 objArrayOop methods_parameter_annotations() const { return _methods_parameter_annotations; }
634 objArrayOop methods_default_annotations() const { return _methods_default_annotations; }
635 void set_class_annotations(typeArrayOop md) { oop_store_without_check((oop*)&_class_annotations, (oop)md); }
636 void set_fields_annotations(objArrayOop md) { set_annotations(md, &_fields_annotations); }
637 void set_methods_annotations(objArrayOop md) { set_annotations(md, &_methods_annotations); }
638 void set_methods_parameter_annotations(objArrayOop md) { set_annotations(md, &_methods_parameter_annotations); }
639 void set_methods_default_annotations(objArrayOop md) { set_annotations(md, &_methods_default_annotations); }
640 typeArrayOop get_method_annotations_of(int idnum)
641 { return get_method_annotations_from(idnum, _methods_annotations); }
642 typeArrayOop get_method_parameter_annotations_of(int idnum)
643 { return get_method_annotations_from(idnum, _methods_parameter_annotations); }
644 typeArrayOop get_method_default_annotations_of(int idnum)
645 { return get_method_annotations_from(idnum, _methods_default_annotations); }
646 void set_method_annotations_of(int idnum, typeArrayOop anno)
647 { set_methods_annotations_of(idnum, anno, &_methods_annotations); }
648 void set_method_parameter_annotations_of(int idnum, typeArrayOop anno)
649 { set_methods_annotations_of(idnum, anno, &_methods_parameter_annotations); }
650 void set_method_default_annotations_of(int idnum, typeArrayOop anno)
651 { set_methods_annotations_of(idnum, anno, &_methods_default_annotations); }
652
653 // allocation
654 DEFINE_ALLOCATE_PERMANENT(instanceKlass);
655 instanceOop allocate_instance(TRAPS);
656 instanceOop allocate_permanent_instance(TRAPS);
657
658 // additional member function to return a handle
659 instanceHandle allocate_instance_handle(TRAPS) { return instanceHandle(THREAD, allocate_instance(THREAD)); }
660
661 objArrayOop allocate_objArray(int n, int length, TRAPS);
662 // Helper function
663 static instanceOop register_finalizer(instanceOop i, TRAPS);
664
665 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
666 // if not, throw either an Error or an Exception.
667 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
668
669 // initialization
670 void call_class_initializer(TRAPS);
671 void set_initialization_state_and_notify(ClassState state, TRAPS);
672
673 // OopMapCache support
674 OopMapCache* oop_map_cache() { return _oop_map_cache; }
675 void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
676 void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
677
678 // JNI identifier support (for static fields - for jni performance)
679 JNIid* jni_ids() { return _jni_ids; }
680 void set_jni_ids(JNIid* ids) { _jni_ids = ids; }
681 JNIid* jni_id_for(int offset);
682
683 // maintenance of deoptimization dependencies
684 int mark_dependent_nmethods(DepChange& changes);
685 void add_dependent_nmethod(nmethod* nm);
686 void remove_dependent_nmethod(nmethod* nm);
687
688 // On-stack replacement support
689 nmethod* osr_nmethods_head() const { return _osr_nmethods_head; };
690 void set_osr_nmethods_head(nmethod* h) { _osr_nmethods_head = h; };
691 void add_osr_nmethod(nmethod* n);
692 void remove_osr_nmethod(nmethod* n);
693 nmethod* lookup_osr_nmethod(const methodOop m, int bci, int level, bool match_level) const;
694
695 // Breakpoint support (see methods on methodOop for details)
696 BreakpointInfo* breakpoints() const { return _breakpoints; };
697 void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
698
699 // support for stub routines
700 static ByteSize init_state_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(instanceKlass, _init_state)); }
701 TRACE_DEFINE_OFFSET;
702 static ByteSize init_thread_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(instanceKlass, _init_thread)); }
703
704 // subclass/subinterface checks
705 bool implements_interface(klassOop k) const;
706
707 // Access to the implementor of an interface.
708 klassOop implementor() const
709 {
710 klassOop* k = (klassOop*)adr_implementor();
711 if (k == NULL) {
712 return NULL;
713 } else {
714 return *k;
715 }
716 }
717
718 void set_implementor(klassOop k) {
719 assert(is_interface(), "not interface");
720 oop* addr = adr_implementor();
721 oop_store_without_check(addr, k);
722 }
723
724 int nof_implementors() const {
725 klassOop k = implementor();
726 if (k == NULL) {
727 return 0;
728 } else if (k != this->as_klassOop()) {
729 return 1;
730 } else {
731 return 2;
732 }
733 }
734
735 void add_implementor(klassOop k); // k is a new class that implements this interface
736 void init_implementor(); // initialize
737
738 // link this class into the implementors list of every interface it implements
739 void process_interfaces(Thread *thread);
740
741 // virtual operations from Klass
742 bool is_leaf_class() const { return _subklass == NULL; }
743 objArrayOop compute_secondary_supers(int num_extra_slots, TRAPS);
744 bool compute_is_subtype_of(klassOop k);
745 bool can_be_primary_super_slow() const;
746 klassOop java_super() const { return super(); }
747 int oop_size(oop obj) const { return size_helper(); }
748 int klass_oop_size() const { return object_size(); }
749 bool oop_is_instance_slow() const { return true; }
750
751 // Iterators
752 void do_local_static_fields(FieldClosure* cl);
753 void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
754 void do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS);
755
756 void methods_do(void f(methodOop method));
757 void array_klasses_do(void f(klassOop k));
758 void with_array_klasses_do(void f(klassOop k));
759 bool super_types_do(SuperTypeClosure* blk);
760
761 // Casting from klassOop
762 static instanceKlass* cast(klassOop k) {
763 assert(k->is_klass(), "must be");
764 Klass* kp = k->klass_part();
765 assert(kp->null_vtbl() || kp->oop_is_instance_slow(), "cast to instanceKlass");
766 return (instanceKlass*) kp;
767 }
768
769 // Sizing (in words)
770 static int header_size() { return align_object_offset(oopDesc::header_size() + sizeof(instanceKlass)/HeapWordSize); }
771
772 int object_size() const
773 {
774 return object_size(align_object_offset(vtable_length()) +
775 align_object_offset(itable_length()) +
776 ((is_interface() || is_anonymous()) ?
777 align_object_offset(nonstatic_oop_map_size()) :
778 nonstatic_oop_map_size()) +
779 (is_interface() ? (int)sizeof(klassOop)/HeapWordSize : 0) +
780 (is_anonymous() ? (int)sizeof(klassOop)/HeapWordSize : 0));
781 }
782 static int vtable_start_offset() { return header_size(); }
783 static int vtable_length_offset() { return oopDesc::header_size() + offset_of(instanceKlass, _vtable_len) / HeapWordSize; }
784 static int object_size(int extra) { return align_object_size(header_size() + extra); }
785
786 intptr_t* start_of_vtable() const { return ((intptr_t*)as_klassOop()) + vtable_start_offset(); }
787 intptr_t* start_of_itable() const { return start_of_vtable() + align_object_offset(vtable_length()); }
788 int itable_offset_in_words() const { return start_of_itable() - (intptr_t*)as_klassOop(); }
789
790 intptr_t* end_of_itable() const { return start_of_itable() + itable_length(); }
791
792 address static_field_addr(int offset);
793
794 OopMapBlock* start_of_nonstatic_oop_maps() const {
795 return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
796 }
797
798 oop* adr_implementor() const {
799 if (is_interface()) {
800 return (oop*)(start_of_nonstatic_oop_maps() +
801 nonstatic_oop_map_count());
802 } else {
803 return NULL;
804 }
805 };
806
807 oop* adr_host_klass() const {
808 if (is_anonymous()) {
809 oop* adr_impl = adr_implementor();
810 if (adr_impl != NULL) {
811 return adr_impl + 1;
812 } else {
813 return (oop*)(start_of_nonstatic_oop_maps() +
814 nonstatic_oop_map_count());
815 }
816 } else {
817 return NULL;
818 }
819 }
820
821 // Allocation profiling support
822 juint alloc_size() const { return _alloc_count * size_helper(); }
823 void set_alloc_size(juint n) {}
824
825 // Use this to return the size of an instance in heap words:
826 int size_helper() const {
827 return layout_helper_to_size_helper(layout_helper());
828 }
829
830 // This bit is initialized in classFileParser.cpp.
831 // It is false under any of the following conditions:
832 // - the class is abstract (including any interface)
833 // - the class has a finalizer (if !RegisterFinalizersAtInit)
834 // - the class size is larger than FastAllocateSizeLimit
835 // - the class is java/lang/Class, which cannot be allocated directly
836 bool can_be_fastpath_allocated() const {
837 return !layout_helper_needs_slow_path(layout_helper());
838 }
839
840 // Java vtable/itable
841 klassVtable* vtable() const; // return new klassVtable wrapper
842 inline methodOop method_at_vtable(int index);
843 klassItable* itable() const; // return new klassItable wrapper
844 methodOop method_at_itable(klassOop holder, int index, TRAPS);
845
846 // Garbage collection
847 void oop_follow_contents(oop obj);
848 int oop_adjust_pointers(oop obj);
849 bool object_is_parsable() const { return _init_state != unparsable_by_gc; }
850 // Value of _init_state must be zero (unparsable_by_gc) when klass field is set.
851
852 void follow_weak_klass_links(
853 BoolObjectClosure* is_alive, OopClosure* keep_alive);
854 void release_C_heap_structures();
855
856 // Parallel Scavenge and Parallel Old
857 PARALLEL_GC_DECLS
858
859 // Naming
860 const char* signature_name() const;
861
862 // Iterators
863 int oop_oop_iterate(oop obj, OopClosure* blk) {
864 return oop_oop_iterate_v(obj, blk);
865 }
866
867 int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
868 return oop_oop_iterate_v_m(obj, blk, mr);
869 }
870
871 #define InstanceKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
872 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \
873 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, \
874 MemRegion mr);
875
876 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DECL)
877 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DECL)
878
879 #ifndef SERIALGC
880 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
881 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
882
883 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
884 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
885 #endif // !SERIALGC
886
887 private:
888 // initialization state
889 #ifdef ASSERT
890 void set_init_state(ClassState state);
891 #else
892 void set_init_state(ClassState state) { _init_state = (u1)state; }
893 #endif
894 void set_rewritten() { _misc_flags |= _misc_rewritten; }
895 void set_init_thread(Thread *thread) { _init_thread = thread; }
896
897 u2 idnum_allocated_count() const { return _idnum_allocated_count; }
898 // The RedefineClasses() API can cause new method idnums to be needed
899 // which will cause the caches to grow. Safety requires different
900 // cache management logic if the caches can grow instead of just
901 // going from NULL to non-NULL.
902 bool idnum_can_increment() const { return has_been_redefined(); }
903 jmethodID* methods_jmethod_ids_acquire() const
904 { return (jmethodID*)OrderAccess::load_ptr_acquire(&_methods_jmethod_ids); }
905 void release_set_methods_jmethod_ids(jmethodID* jmeths)
906 { OrderAccess::release_store_ptr(&_methods_jmethod_ids, jmeths); }
907
908 int* methods_cached_itable_indices_acquire() const
909 { return (int*)OrderAccess::load_ptr_acquire(&_methods_cached_itable_indices); }
910 void release_set_methods_cached_itable_indices(int* indices)
911 { OrderAccess::release_store_ptr(&_methods_cached_itable_indices, indices); }
912
913 inline typeArrayOop get_method_annotations_from(int idnum, objArrayOop annos);
914 void set_annotations(objArrayOop md, objArrayOop* md_p) { oop_store_without_check((oop*)md_p, (oop)md); }
915 void set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p);
916
917 // Offsets for memory management
918 oop* adr_array_klasses() const { return (oop*)&this->_array_klasses;}
919 oop* adr_methods() const { return (oop*)&this->_methods;}
920 oop* adr_method_ordering() const { return (oop*)&this->_method_ordering;}
921 oop* adr_local_interfaces() const { return (oop*)&this->_local_interfaces;}
922 oop* adr_transitive_interfaces() const { return (oop*)&this->_transitive_interfaces;}
923 oop* adr_fields() const { return (oop*)&this->_fields;}
924 oop* adr_constants() const { return (oop*)&this->_constants;}
925 oop* adr_class_loader() const { return (oop*)&this->_class_loader;}
926 oop* adr_protection_domain() const { return (oop*)&this->_protection_domain;}
927 oop* adr_signers() const { return (oop*)&this->_signers;}
928 oop* adr_inner_classes() const { return (oop*)&this->_inner_classes;}
929 oop* adr_methods_jmethod_ids() const { return (oop*)&this->_methods_jmethod_ids;}
930 oop* adr_methods_cached_itable_indices() const { return (oop*)&this->_methods_cached_itable_indices;}
931 oop* adr_class_annotations() const { return (oop*)&this->_class_annotations;}
932 oop* adr_fields_annotations() const { return (oop*)&this->_fields_annotations;}
933 oop* adr_methods_annotations() const { return (oop*)&this->_methods_annotations;}
934 oop* adr_methods_parameter_annotations() const { return (oop*)&this->_methods_parameter_annotations;}
935 oop* adr_methods_default_annotations() const { return (oop*)&this->_methods_default_annotations;}
936
937 // Static methods that are used to implement member methods where an exposed this pointer
938 // is needed due to possible GCs
939 static bool link_class_impl (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
940 static bool verify_code (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
941 static void initialize_impl (instanceKlassHandle this_oop, TRAPS);
942 static void eager_initialize_impl (instanceKlassHandle this_oop);
943 static void set_initialization_state_and_notify_impl (instanceKlassHandle this_oop, ClassState state, TRAPS);
944 static void call_class_initializer_impl (instanceKlassHandle this_oop, TRAPS);
945 static klassOop array_klass_impl (instanceKlassHandle this_oop, bool or_null, int n, TRAPS);
946 static void do_local_static_fields_impl (instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS);
947 /* jni_id_for_impl for jfieldID only */
948 static JNIid* jni_id_for_impl (instanceKlassHandle this_oop, int offset);
949
950 // Returns the array class for the n'th dimension
951 klassOop array_klass_impl(bool or_null, int n, TRAPS);
952
953 // Returns the array class with this class as element type
954 klassOop array_klass_impl(bool or_null, TRAPS);
955
956 public:
957 // sharing support
958 virtual void remove_unshareable_info();
959 virtual void shared_symbols_iterate(SymbolClosure* closure);
960
961 // jvm support
962 jint compute_modifier_flags(TRAPS) const;
963
964 public:
965 // JVMTI support
966 jint jvmti_class_status() const;
967
968 public:
969 // Printing
970 void oop_print_value_on(oop obj, outputStream* st);
971 #ifndef PRODUCT
972 void oop_print_on (oop obj, outputStream* st);
973
974 void print_dependent_nmethods(bool verbose = false);
975 bool is_dependent_nmethod(nmethod* nm);
976 #endif
977
978 // Verification
979 const char* internal_name() const;
980 void oop_verify_on(oop obj, outputStream* st);
981 };
982
983 inline methodOop instanceKlass::method_at_vtable(int index) {
984 #ifndef PRODUCT
985 assert(index >= 0, "valid vtable index");
986 if (DebugVtables) {
987 verify_vtable_index(index);
988 }
989 #endif
990 vtableEntry* ve = (vtableEntry*)start_of_vtable();
991 return ve[index].method();
992 }
993
994 inline typeArrayOop instanceKlass::get_method_annotations_from(int idnum, objArrayOop annos) {
995 if (annos == NULL || annos->length() <= idnum) {
996 return NULL;
997 }
998 return typeArrayOop(annos->obj_at(idnum));
999 }
1000
1001 // for adding methods
1002 // UNSET_IDNUM return means no more ids available
1003 inline u2 instanceKlass::next_method_idnum() {
1004 if (_idnum_allocated_count == constMethodOopDesc::MAX_IDNUM) {
1005 return constMethodOopDesc::UNSET_IDNUM; // no more ids available
1006 } else {
1007 return _idnum_allocated_count++;
1008 }
1009 }
1010
1011
1012 /* JNIid class for jfieldIDs only */
1013 class JNIid: public CHeapObj<mtClass> {
1014 friend class VMStructs;
1015 private:
1016 klassOop _holder;
1017 JNIid* _next;
1018 int _offset;
1019 #ifdef ASSERT
1020 bool _is_static_field_id;
1021 #endif
1022
1023 public:
1024 // Accessors
1025 klassOop holder() const { return _holder; }
1026 int offset() const { return _offset; }
1027 JNIid* next() { return _next; }
1028 // Constructor
1029 JNIid(klassOop holder, int offset, JNIid* next);
1030 // Identifier lookup
1031 JNIid* find(int offset);
1032
1033 bool find_local_field(fieldDescriptor* fd) {
1034 return instanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1035 }
1036
1037 // Garbage collection support
1038 oop* holder_addr() { return (oop*)&_holder; }
1039 void oops_do(OopClosure* f);
1040 static void deallocate(JNIid* id);
1041 // Debugging
1042 #ifdef ASSERT
1043 bool is_static_field_id() const { return _is_static_field_id; }
1044 void set_is_static_field_id() { _is_static_field_id = true; }
1045 #endif
1046 void verify(klassOop holder);
1047 };
1048
1049
1050 // If breakpoints are more numerous than just JVMTI breakpoints,
1051 // consider compressing this data structure.
1052 // It is currently a simple linked list defined in methodOop.hpp.
1053
1054 class BreakpointInfo;
1055
1056
1057 // A collection point for interesting information about the previous
1058 // version(s) of an instanceKlass. This class uses weak references to
1059 // the information so that the information may be collected as needed
1060 // by the system. If the information is shared, then a regular
1061 // reference must be used because a weak reference would be seen as
1062 // collectible. A GrowableArray of PreviousVersionNodes is attached
1063 // to the instanceKlass as needed. See PreviousVersionWalker below.
1064 class PreviousVersionNode : public CHeapObj<mtClass> {
1065 private:
1066 // A shared ConstantPool is never collected so we'll always have
1067 // a reference to it so we can update items in the cache. We'll
1068 // have a weak reference to a non-shared ConstantPool until all
1069 // of the methods (EMCP or obsolete) have been collected; the
1070 // non-shared ConstantPool becomes collectible at that point.
1071 jobject _prev_constant_pool; // regular or weak reference
1072 bool _prev_cp_is_weak; // true if not a shared ConstantPool
1073
1074 // If the previous version of the instanceKlass doesn't have any
1075 // EMCP methods, then _prev_EMCP_methods will be NULL. If all the
1076 // EMCP methods have been collected, then _prev_EMCP_methods can
1077 // have a length of zero.
1078 GrowableArray<jweak>* _prev_EMCP_methods;
1079
1080 public:
1081 PreviousVersionNode(jobject prev_constant_pool, bool prev_cp_is_weak,
1082 GrowableArray<jweak>* prev_EMCP_methods);
1083 ~PreviousVersionNode();
1084 jobject prev_constant_pool() const {
1085 return _prev_constant_pool;
1086 }
1087 GrowableArray<jweak>* prev_EMCP_methods() const {
1088 return _prev_EMCP_methods;
1089 }
1090 };
1091
1092
1093 // A Handle-ized version of PreviousVersionNode.
1094 class PreviousVersionInfo : public ResourceObj {
1095 private:
1096 constantPoolHandle _prev_constant_pool_handle;
1097 // If the previous version of the instanceKlass doesn't have any
1098 // EMCP methods, then _prev_EMCP_methods will be NULL. Since the
1099 // methods cannot be collected while we hold a handle,
1100 // _prev_EMCP_methods should never have a length of zero.
1101 GrowableArray<methodHandle>* _prev_EMCP_method_handles;
1102
1103 public:
1104 PreviousVersionInfo(PreviousVersionNode *pv_node);
1105 ~PreviousVersionInfo();
1106 constantPoolHandle prev_constant_pool_handle() const {
1107 return _prev_constant_pool_handle;
1108 }
1109 GrowableArray<methodHandle>* prev_EMCP_method_handles() const {
1110 return _prev_EMCP_method_handles;
1111 }
1112 };
1113
1114
1115 // Helper object for walking previous versions. This helper cleans up
1116 // the Handles that it allocates when the helper object is destroyed.
1117 // The PreviousVersionInfo object returned by next_previous_version()
1118 // is only valid until a subsequent call to next_previous_version() or
1119 // the helper object is destroyed.
1120 class PreviousVersionWalker : public StackObj {
1121 private:
1122 GrowableArray<PreviousVersionNode *>* _previous_versions;
1123 int _current_index;
1124 // Fields for cleaning up when we are done walking the previous versions:
1125 // A HandleMark for the PreviousVersionInfo handles:
1126 HandleMark _hm;
1127
1128 // It would be nice to have a ResourceMark field in this helper also,
1129 // but the ResourceMark code says to be careful to delete handles held
1130 // in GrowableArrays _before_ deleting the GrowableArray. Since we
1131 // can't guarantee the order in which the fields are destroyed, we
1132 // have to let the creator of the PreviousVersionWalker object do
1133 // the right thing. Also, adding a ResourceMark here causes an
1134 // include loop.
1135
1136 // A pointer to the current info object so we can handle the deletes.
1137 PreviousVersionInfo * _current_p;
1138
1139 public:
1140 PreviousVersionWalker(instanceKlass *ik);
1141 ~PreviousVersionWalker();
1142
1143 // Return the interesting information for the next previous version
1144 // of the klass. Returns NULL if there are no more previous versions.
1145 PreviousVersionInfo* next_previous_version();
1146 };
1147
1148
1149 //
1150 // nmethodBucket is used to record dependent nmethods for
1151 // deoptimization. nmethod dependencies are actually <klass, method>
1152 // pairs but we really only care about the klass part for purposes of
1153 // finding nmethods which might need to be deoptimized. Instead of
1154 // recording the method, a count of how many times a particular nmethod
1155 // was recorded is kept. This ensures that any recording errors are
1156 // noticed since an nmethod should be removed as many times are it's
1157 // added.
1158 //
1159 class nmethodBucket: public CHeapObj<mtClass> {
1160 friend class VMStructs;
1161 private:
1162 nmethod* _nmethod;
1163 int _count;
1164 nmethodBucket* _next;
1165
1166 public:
1167 nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
1168 _nmethod = nmethod;
1169 _next = next;
1170 _count = 1;
1171 }
1172 int count() { return _count; }
1173 int increment() { _count += 1; return _count; }
1174 int decrement() { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
1175 nmethodBucket* next() { return _next; }
1176 void set_next(nmethodBucket* b) { _next = b; }
1177 nmethod* get_nmethod() { return _nmethod; }
1178 };
1179
1180 // An iterator that's used to access the inner classes indices in the
1181 // instanceKlass::_inner_classes array.
1182 class InnerClassesIterator : public StackObj {
1183 private:
1184 typeArrayHandle _inner_classes;
1185 int _length;
1186 int _idx;
1187 public:
1188
1189 InnerClassesIterator(instanceKlassHandle k) {
1190 _inner_classes = k->inner_classes();
1191 if (k->inner_classes() != NULL) {
1192 _length = _inner_classes->length();
1193 // The inner class array's length should be the multiple of
1194 // inner_class_next_offset if it only contains the InnerClasses
1195 // attribute data, or it should be
1196 // n*inner_class_next_offset+enclosing_method_attribute_size
1197 // if it also contains the EnclosingMethod data.
1198 assert((_length % instanceKlass::inner_class_next_offset == 0 ||
1199 _length % instanceKlass::inner_class_next_offset == instanceKlass::enclosing_method_attribute_size),
1200 "just checking");
1201 // Remove the enclosing_method portion if exists.
1202 if (_length % instanceKlass::inner_class_next_offset == instanceKlass::enclosing_method_attribute_size) {
1203 _length -= instanceKlass::enclosing_method_attribute_size;
1204 }
1205 } else {
1206 _length = 0;
1207 }
1208 _idx = 0;
1209 }
1210
1211 int length() const {
1212 return _length;
1213 }
1214
1215 void next() {
1216 _idx += instanceKlass::inner_class_next_offset;
1217 }
1218
1219 bool done() const {
1220 return (_idx >= _length);
1221 }
1222
1223 u2 inner_class_info_index() const {
1224 return _inner_classes->ushort_at(
1225 _idx + instanceKlass::inner_class_inner_class_info_offset);
1226 }
1227
1228 void set_inner_class_info_index(u2 index) {
1229 _inner_classes->ushort_at_put(
1230 _idx + instanceKlass::inner_class_inner_class_info_offset, index);
1231 }
1232
1233 u2 outer_class_info_index() const {
1234 return _inner_classes->ushort_at(
1235 _idx + instanceKlass::inner_class_outer_class_info_offset);
1236 }
1237
1238 void set_outer_class_info_index(u2 index) {
1239 _inner_classes->ushort_at_put(
1240 _idx + instanceKlass::inner_class_outer_class_info_offset, index);
1241 }
1242
1243 u2 inner_name_index() const {
1244 return _inner_classes->ushort_at(
1245 _idx + instanceKlass::inner_class_inner_name_offset);
1246 }
1247
1248 void set_inner_name_index(u2 index) {
1249 _inner_classes->ushort_at_put(
1250 _idx + instanceKlass::inner_class_inner_name_offset, index);
1251 }
1252
1253 u2 inner_access_flags() const {
1254 return _inner_classes->ushort_at(
1255 _idx + instanceKlass::inner_class_access_flags_offset);
1256 }
1257 };
1258
1259 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP