Wed, 11 Jan 2012 17:34:02 -0500
7115199: Add event tracing hooks and Java Flight Recorder infrastructure
Summary: Added a nop tracing infrastructure, JFR makefile changes and other infrastructure used only by JFR.
Reviewed-by: acorn, sspitsyn
Contributed-by: markus.gronlund@oracle.com
1 /*
2 * Copyright (c) 1997, 2011, 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 */
25 #ifndef SHARE_VM_OOPS_KLASS_HPP
26 #define SHARE_VM_OOPS_KLASS_HPP
28 #include "memory/genOopClosures.hpp"
29 #include "memory/iterator.hpp"
30 #include "memory/memRegion.hpp"
31 #include "memory/specialized_oop_closures.hpp"
32 #include "oops/klassOop.hpp"
33 #include "oops/klassPS.hpp"
34 #include "oops/oop.hpp"
35 #include "runtime/orderAccess.hpp"
36 #include "trace/traceMacros.hpp"
37 #include "utilities/accessFlags.hpp"
38 #ifndef SERIALGC
39 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp"
40 #include "gc_implementation/g1/g1OopClosures.hpp"
41 #include "gc_implementation/parNew/parOopClosures.hpp"
42 #endif
44 // A Klass is the part of the klassOop that provides:
45 // 1: language level class object (method dictionary etc.)
46 // 2: provide vm dispatch behavior for the object
47 // Both functions are combined into one C++ class. The toplevel class "Klass"
48 // implements purpose 1 whereas all subclasses provide extra virtual functions
49 // for purpose 2.
51 // One reason for the oop/klass dichotomy in the implementation is
52 // that we don't want a C++ vtbl pointer in every object. Thus,
53 // normal oops don't have any virtual functions. Instead, they
54 // forward all "virtual" functions to their klass, which does have
55 // a vtbl and does the C++ dispatch depending on the object's
56 // actual type. (See oop.inline.hpp for some of the forwarding code.)
57 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"!
59 // Klass layout:
60 // [header ] klassOop
61 // [klass pointer ] klassOop
62 // [C++ vtbl ptr ] (contained in Klass_vtbl)
63 // [layout_helper ]
64 // [super_check_offset ] for fast subtype checks
65 // [secondary_super_cache] for fast subtype checks
66 // [secondary_supers ] array of 2ndary supertypes
67 // [primary_supers 0]
68 // [primary_supers 1]
69 // [primary_supers 2]
70 // ...
71 // [primary_supers 7]
72 // [java_mirror ]
73 // [super ]
74 // [name ]
75 // [first subklass]
76 // [next_sibling ] link to chain additional subklasses
77 // [modifier_flags]
78 // [access_flags ]
79 // [verify_count ] - not in product
80 // [alloc_count ]
81 // [last_biased_lock_bulk_revocation_time] (64 bits)
82 // [prototype_header]
83 // [biased_lock_revocation_count]
84 // [trace_id]
87 // Forward declarations.
88 class klassVtable;
89 class KlassHandle;
90 class OrderAccess;
92 // Holder (or cage) for the C++ vtable of each kind of Klass.
93 // We want to tightly constrain the location of the C++ vtable in the overall layout.
94 class Klass_vtbl {
95 protected:
96 // The following virtual exists only to force creation of a C++ vtable,
97 // so that this class truly is the location of the vtable of all Klasses.
98 virtual void unused_initial_virtual() { }
100 public:
101 // The following virtual makes Klass_vtbl play a second role as a
102 // factory protocol for subclasses of Klass ("sub-Klasses").
103 // Here's how it works....
104 //
105 // This VM uses metaobjects as factories for their instances.
106 //
107 // In order to initialize the C++ vtable of a new instance, its
108 // metaobject is forced to use the C++ placed new operator to
109 // allocate the instance. In a typical C++-based system, each
110 // sub-class would have its own factory routine which
111 // directly uses the placed new operator on the desired class,
112 // and then calls the appropriate chain of C++ constructors.
113 //
114 // However, this system uses shared code to performs the first
115 // allocation and initialization steps for all sub-Klasses.
116 // (See base_create_klass() and base_create_array_klass().)
117 // This does not factor neatly into a hierarchy of C++ constructors.
118 // Each caller of these shared "base_create" routines knows
119 // exactly which sub-Klass it is creating, but the shared routine
120 // does not, even though it must perform the actual allocation.
121 //
122 // Therefore, the caller of the shared "base_create" must wrap
123 // the specific placed new call in a virtual function which
124 // performs the actual allocation and vtable set-up. That
125 // virtual function is here, Klass_vtbl::allocate_permanent.
126 //
127 // The arguments to Universe::allocate_permanent() are passed
128 // straight through the placed new operator, which in turn
129 // obtains them directly from this virtual call.
130 //
131 // This virtual is called on a temporary "example instance" of the
132 // sub-Klass being instantiated, a C++ auto variable. The "real"
133 // instance created by this virtual is on the VM heap, where it is
134 // equipped with a klassOopDesc header.
135 //
136 // It is merely an accident of implementation that we use "example
137 // instances", but that is why the virtual function which implements
138 // each sub-Klass factory happens to be defined by the same sub-Klass
139 // for which it creates instances.
140 //
141 // The vtbl_value() call (see below) is used to strip away the
142 // accidental Klass-ness from an "example instance" and present it as
143 // a factory. Think of each factory object as a mere container of the
144 // C++ vtable for the desired sub-Klass. Since C++ does not allow
145 // direct references to vtables, the factory must also be delegated
146 // the task of allocating the instance, but the essential point is
147 // that the factory knows how to initialize the C++ vtable with the
148 // right pointer value. All other common initializations are handled
149 // by the shared "base_create" subroutines.
150 //
151 virtual void* allocate_permanent(KlassHandle& klass, int size, TRAPS) const = 0;
152 void post_new_init_klass(KlassHandle& klass, klassOop obj, int size) const;
154 // Every subclass on which vtbl_value is called must include this macro.
155 // Delay the installation of the klassKlass pointer until after the
156 // the vtable for a new klass has been installed (after the call to new()).
157 #define DEFINE_ALLOCATE_PERMANENT(thisKlass) \
158 void* allocate_permanent(KlassHandle& klass_klass, int size, TRAPS) const { \
159 void* result = new(klass_klass, size, THREAD) thisKlass(); \
160 if (HAS_PENDING_EXCEPTION) return NULL; \
161 klassOop new_klass = ((Klass*) result)->as_klassOop(); \
162 OrderAccess::storestore(); \
163 post_new_init_klass(klass_klass, new_klass, size); \
164 return result; \
165 }
167 bool null_vtbl() { return *(intptr_t*)this == 0; }
169 protected:
170 void* operator new(size_t ignored, KlassHandle& klass, int size, TRAPS);
171 };
174 class Klass : public Klass_vtbl {
175 friend class VMStructs;
176 protected:
177 // note: put frequently-used fields together at start of klass structure
178 // for better cache behavior (may not make much of a difference but sure won't hurt)
179 enum { _primary_super_limit = 8 };
181 // The "layout helper" is a combined descriptor of object layout.
182 // For klasses which are neither instance nor array, the value is zero.
183 //
184 // For instances, layout helper is a positive number, the instance size.
185 // This size is already passed through align_object_size and scaled to bytes.
186 // The low order bit is set if instances of this class cannot be
187 // allocated using the fastpath.
188 //
189 // For arrays, layout helper is a negative number, containing four
190 // distinct bytes, as follows:
191 // MSB:[tag, hsz, ebt, log2(esz)]:LSB
192 // where:
193 // tag is 0x80 if the elements are oops, 0xC0 if non-oops
194 // hsz is array header size in bytes (i.e., offset of first element)
195 // ebt is the BasicType of the elements
196 // esz is the element size in bytes
197 // This packed word is arranged so as to be quickly unpacked by the
198 // various fast paths that use the various subfields.
199 //
200 // The esz bits can be used directly by a SLL instruction, without masking.
201 //
202 // Note that the array-kind tag looks like 0x00 for instance klasses,
203 // since their length in bytes is always less than 24Mb.
204 //
205 // Final note: This comes first, immediately after Klass_vtbl,
206 // because it is frequently queried.
207 jint _layout_helper;
209 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers
210 // and _primary_supers all help make fast subtype checks. See big discussion
211 // in doc/server_compiler/checktype.txt
212 //
213 // Where to look to observe a supertype (it is &_secondary_super_cache for
214 // secondary supers, else is &_primary_supers[depth()].
215 juint _super_check_offset;
217 // Class name. Instance classes: java/lang/String, etc. Array classes: [I,
218 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes.
219 Symbol* _name;
221 public:
222 oop* oop_block_beg() const { return adr_secondary_super_cache(); }
223 oop* oop_block_end() const { return adr_next_sibling() + 1; }
225 protected:
226 //
227 // The oop block. All oop fields must be declared here and only oop fields
228 // may be declared here. In addition, the first and last fields in this block
229 // must remain first and last, unless oop_block_beg() and/or oop_block_end()
230 // are updated. Grouping the oop fields in a single block simplifies oop
231 // iteration.
232 //
234 // Cache of last observed secondary supertype
235 klassOop _secondary_super_cache;
236 // Array of all secondary supertypes
237 objArrayOop _secondary_supers;
238 // Ordered list of all primary supertypes
239 klassOop _primary_supers[_primary_super_limit];
240 // java/lang/Class instance mirroring this class
241 oop _java_mirror;
242 // Superclass
243 klassOop _super;
244 // First subclass (NULL if none); _subklass->next_sibling() is next one
245 klassOop _subklass;
246 // Sibling link (or NULL); links all subklasses of a klass
247 klassOop _next_sibling;
249 //
250 // End of the oop block.
251 //
253 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers.
254 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here.
256 #ifndef PRODUCT
257 int _verify_count; // to avoid redundant verifies
258 #endif
260 juint _alloc_count; // allocation profiling support - update klass_size_in_bytes() if moved/deleted
262 // Biased locking implementation and statistics
263 // (the 64-bit chunk goes first, to avoid some fragmentation)
264 jlong _last_biased_lock_bulk_revocation_time;
265 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type
266 jint _biased_lock_revocation_count;
268 #ifdef TRACE_DEFINE_KLASS_TRACE_ID
269 TRACE_DEFINE_KLASS_TRACE_ID;
270 #endif
271 public:
273 // returns the enclosing klassOop
274 klassOop as_klassOop() const {
275 // see klassOop.hpp for layout.
276 return (klassOop) (((char*) this) - sizeof(klassOopDesc));
277 }
279 public:
280 // Allocation
281 const Klass_vtbl& vtbl_value() const { return *this; } // used only on "example instances"
282 static KlassHandle base_create_klass(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS);
283 static klassOop base_create_klass_oop(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS);
285 // super
286 klassOop super() const { return _super; }
287 void set_super(klassOop k) { oop_store_without_check((oop*) &_super, (oop) k); }
289 // initializes _super link, _primary_supers & _secondary_supers arrays
290 void initialize_supers(klassOop k, TRAPS);
291 void initialize_supers_impl1(klassOop k);
292 void initialize_supers_impl2(klassOop k);
294 // klass-specific helper for initializing _secondary_supers
295 virtual objArrayOop compute_secondary_supers(int num_extra_slots, TRAPS);
297 // java_super is the Java-level super type as specified by Class.getSuperClass.
298 virtual klassOop java_super() const { return NULL; }
300 juint super_check_offset() const { return _super_check_offset; }
301 void set_super_check_offset(juint o) { _super_check_offset = o; }
303 klassOop secondary_super_cache() const { return _secondary_super_cache; }
304 void set_secondary_super_cache(klassOop k) { oop_store_without_check((oop*) &_secondary_super_cache, (oop) k); }
306 objArrayOop secondary_supers() const { return _secondary_supers; }
307 void set_secondary_supers(objArrayOop k) { oop_store_without_check((oop*) &_secondary_supers, (oop) k); }
309 // Return the element of the _super chain of the given depth.
310 // If there is no such element, return either NULL or this.
311 klassOop primary_super_of_depth(juint i) const {
312 assert(i < primary_super_limit(), "oob");
313 klassOop super = _primary_supers[i];
314 assert(super == NULL || super->klass_part()->super_depth() == i, "correct display");
315 return super;
316 }
318 // Can this klass be a primary super? False for interfaces and arrays of
319 // interfaces. False also for arrays or classes with long super chains.
320 bool can_be_primary_super() const {
321 const juint secondary_offset = secondary_super_cache_offset_in_bytes() + sizeof(oopDesc);
322 return super_check_offset() != secondary_offset;
323 }
324 virtual bool can_be_primary_super_slow() const;
326 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit].
327 juint super_depth() const {
328 if (!can_be_primary_super()) {
329 return primary_super_limit();
330 } else {
331 juint d = (super_check_offset() - (primary_supers_offset_in_bytes() + sizeof(oopDesc))) / sizeof(klassOop);
332 assert(d < primary_super_limit(), "oob");
333 assert(_primary_supers[d] == as_klassOop(), "proper init");
334 return d;
335 }
336 }
338 // java mirror
339 oop java_mirror() const { return _java_mirror; }
340 void set_java_mirror(oop m) { oop_store((oop*) &_java_mirror, m); }
342 // modifier flags
343 jint modifier_flags() const { return _modifier_flags; }
344 void set_modifier_flags(jint flags) { _modifier_flags = flags; }
346 // size helper
347 int layout_helper() const { return _layout_helper; }
348 void set_layout_helper(int lh) { _layout_helper = lh; }
350 // Note: for instances layout_helper() may include padding.
351 // Use instanceKlass::contains_field_offset to classify field offsets.
353 // sub/superklass links
354 instanceKlass* superklass() const;
355 Klass* subklass() const;
356 Klass* next_sibling() const;
357 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list
358 void remove_from_sibling_list(); // remove receiver from sibling list
359 protected: // internal accessors
360 klassOop subklass_oop() const { return _subklass; }
361 klassOop next_sibling_oop() const { return _next_sibling; }
362 void set_subklass(klassOop s);
363 void set_next_sibling(klassOop s);
365 oop* adr_super() const { return (oop*)&_super; }
366 oop* adr_primary_supers() const { return (oop*)&_primary_supers[0]; }
367 oop* adr_secondary_super_cache() const { return (oop*)&_secondary_super_cache; }
368 oop* adr_secondary_supers()const { return (oop*)&_secondary_supers; }
369 oop* adr_java_mirror() const { return (oop*)&_java_mirror; }
370 oop* adr_subklass() const { return (oop*)&_subklass; }
371 oop* adr_next_sibling() const { return (oop*)&_next_sibling; }
373 public:
374 // Allocation profiling support
375 juint alloc_count() const { return _alloc_count; }
376 void set_alloc_count(juint n) { _alloc_count = n; }
377 virtual juint alloc_size() const = 0;
378 virtual void set_alloc_size(juint n) = 0;
380 // Compiler support
381 static int super_offset_in_bytes() { return offset_of(Klass, _super); }
382 static int super_check_offset_offset_in_bytes() { return offset_of(Klass, _super_check_offset); }
383 static int primary_supers_offset_in_bytes(){ return offset_of(Klass, _primary_supers); }
384 static int secondary_super_cache_offset_in_bytes() { return offset_of(Klass, _secondary_super_cache); }
385 static int secondary_supers_offset_in_bytes() { return offset_of(Klass, _secondary_supers); }
386 static int java_mirror_offset_in_bytes() { return offset_of(Klass, _java_mirror); }
387 static int modifier_flags_offset_in_bytes(){ return offset_of(Klass, _modifier_flags); }
388 static int layout_helper_offset_in_bytes() { return offset_of(Klass, _layout_helper); }
389 static int access_flags_offset_in_bytes() { return offset_of(Klass, _access_flags); }
391 // Unpacking layout_helper:
392 enum {
393 _lh_neutral_value = 0, // neutral non-array non-instance value
394 _lh_instance_slow_path_bit = 0x01,
395 _lh_log2_element_size_shift = BitsPerByte*0,
396 _lh_log2_element_size_mask = BitsPerLong-1,
397 _lh_element_type_shift = BitsPerByte*1,
398 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask
399 _lh_header_size_shift = BitsPerByte*2,
400 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask
401 _lh_array_tag_bits = 2,
402 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits,
403 _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30
404 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30
405 };
407 static int layout_helper_size_in_bytes(jint lh) {
408 assert(lh > (jint)_lh_neutral_value, "must be instance");
409 return (int) lh & ~_lh_instance_slow_path_bit;
410 }
411 static bool layout_helper_needs_slow_path(jint lh) {
412 assert(lh > (jint)_lh_neutral_value, "must be instance");
413 return (lh & _lh_instance_slow_path_bit) != 0;
414 }
415 static bool layout_helper_is_instance(jint lh) {
416 return (jint)lh > (jint)_lh_neutral_value;
417 }
418 static bool layout_helper_is_javaArray(jint lh) {
419 return (jint)lh < (jint)_lh_neutral_value;
420 }
421 static bool layout_helper_is_typeArray(jint lh) {
422 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift);
423 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift);
424 }
425 static bool layout_helper_is_objArray(jint lh) {
426 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift);
427 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift);
428 }
429 static int layout_helper_header_size(jint lh) {
430 assert(lh < (jint)_lh_neutral_value, "must be array");
431 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask;
432 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity");
433 return hsize;
434 }
435 static BasicType layout_helper_element_type(jint lh) {
436 assert(lh < (jint)_lh_neutral_value, "must be array");
437 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask;
438 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity");
439 return (BasicType) btvalue;
440 }
441 static int layout_helper_log2_element_size(jint lh) {
442 assert(lh < (jint)_lh_neutral_value, "must be array");
443 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask;
444 assert(l2esz <= LogBitsPerLong, "sanity");
445 return l2esz;
446 }
447 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) {
448 return (tag << _lh_array_tag_shift)
449 | (hsize << _lh_header_size_shift)
450 | ((int)etype << _lh_element_type_shift)
451 | (log2_esize << _lh_log2_element_size_shift);
452 }
453 static jint instance_layout_helper(jint size, bool slow_path_flag) {
454 return (size << LogHeapWordSize)
455 | (slow_path_flag ? _lh_instance_slow_path_bit : 0);
456 }
457 static int layout_helper_to_size_helper(jint lh) {
458 assert(lh > (jint)_lh_neutral_value, "must be instance");
459 // Note that the following expression discards _lh_instance_slow_path_bit.
460 return lh >> LogHeapWordSize;
461 }
462 // Out-of-line version computes everything based on the etype:
463 static jint array_layout_helper(BasicType etype);
465 // What is the maximum number of primary superclasses any klass can have?
466 #ifdef PRODUCT
467 static juint primary_super_limit() { return _primary_super_limit; }
468 #else
469 static juint primary_super_limit() {
470 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob");
471 return FastSuperclassLimit;
472 }
473 #endif
475 // vtables
476 virtual klassVtable* vtable() const { return NULL; }
478 static int klass_size_in_bytes() { return offset_of(Klass, _alloc_count) + sizeof(juint); } // all "visible" fields
480 // subclass check
481 bool is_subclass_of(klassOop k) const;
482 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it
483 bool is_subtype_of(klassOop k) const {
484 juint off = k->klass_part()->super_check_offset();
485 klassOop sup = *(klassOop*)( (address)as_klassOop() + off );
486 const juint secondary_offset = secondary_super_cache_offset_in_bytes() + sizeof(oopDesc);
487 if (sup == k) {
488 return true;
489 } else if (off != secondary_offset) {
490 return false;
491 } else {
492 return search_secondary_supers(k);
493 }
494 }
495 bool search_secondary_supers(klassOop k) const;
497 // Find LCA in class hierarchy
498 Klass *LCA( Klass *k );
500 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
501 // if not, throw either an Error or an Exception.
502 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
504 // Casting
505 static Klass* cast(klassOop k) {
506 assert(k->is_klass(), "cast to Klass");
507 return k->klass_part();
508 }
510 // array copying
511 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
513 // tells if the class should be initialized
514 virtual bool should_be_initialized() const { return false; }
515 // initializes the klass
516 virtual void initialize(TRAPS);
517 // lookup operation for MethodLookupCache
518 friend class MethodLookupCache;
519 virtual methodOop uncached_lookup_method(Symbol* name, Symbol* signature) const;
520 public:
521 methodOop lookup_method(Symbol* name, Symbol* signature) const {
522 return uncached_lookup_method(name, signature);
523 }
525 // array class with specific rank
526 klassOop array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); }
528 // array class with this klass as element type
529 klassOop array_klass(TRAPS) { return array_klass_impl(false, THREAD); }
531 // These will return NULL instead of allocating on the heap:
532 // NB: these can block for a mutex, like other functions with TRAPS arg.
533 klassOop array_klass_or_null(int rank);
534 klassOop array_klass_or_null();
536 virtual oop protection_domain() { return NULL; }
537 virtual oop class_loader() const { return NULL; }
539 protected:
540 virtual klassOop array_klass_impl(bool or_null, int rank, TRAPS);
541 virtual klassOop array_klass_impl(bool or_null, TRAPS);
543 public:
544 virtual void remove_unshareable_info();
545 virtual void shared_symbols_iterate(SymbolClosure* closure);
547 protected:
548 // computes the subtype relationship
549 virtual bool compute_is_subtype_of(klassOop k);
550 public:
551 // subclass accessor (here for convenience; undefined for non-klass objects)
552 virtual bool is_leaf_class() const { fatal("not a class"); return false; }
553 public:
554 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP
555 // These functions describe behavior for the oop not the KLASS.
557 // actual oop size of obj in memory
558 virtual int oop_size(oop obj) const = 0;
560 // actual oop size of this klass in memory
561 virtual int klass_oop_size() const = 0;
563 // Returns the Java name for a class (Resource allocated)
564 // For arrays, this returns the name of the element with a leading '['.
565 // For classes, this returns the name with the package separators
566 // turned into '.'s.
567 const char* external_name() const;
568 // Returns the name for a class (Resource allocated) as the class
569 // would appear in a signature.
570 // For arrays, this returns the name of the element with a leading '['.
571 // For classes, this returns the name with a leading 'L' and a trailing ';'
572 // and the package separators as '/'.
573 virtual const char* signature_name() const;
575 // garbage collection support
576 virtual void oop_follow_contents(oop obj) = 0;
577 virtual int oop_adjust_pointers(oop obj) = 0;
579 // Parallel Scavenge and Parallel Old
580 PARALLEL_GC_DECLS_PV
582 public:
583 // type testing operations
584 virtual bool oop_is_instance_slow() const { return false; }
585 virtual bool oop_is_instanceMirror() const { return false; }
586 virtual bool oop_is_instanceRef() const { return false; }
587 virtual bool oop_is_array() const { return false; }
588 virtual bool oop_is_objArray_slow() const { return false; }
589 virtual bool oop_is_klass() const { return false; }
590 virtual bool oop_is_thread() const { return false; }
591 virtual bool oop_is_method() const { return false; }
592 virtual bool oop_is_constMethod() const { return false; }
593 virtual bool oop_is_methodData() const { return false; }
594 virtual bool oop_is_constantPool() const { return false; }
595 virtual bool oop_is_constantPoolCache() const { return false; }
596 virtual bool oop_is_typeArray_slow() const { return false; }
597 virtual bool oop_is_arrayKlass() const { return false; }
598 virtual bool oop_is_objArrayKlass() const { return false; }
599 virtual bool oop_is_typeArrayKlass() const { return false; }
600 virtual bool oop_is_compiledICHolder() const { return false; }
601 virtual bool oop_is_instanceKlass() const { return false; }
603 bool oop_is_javaArray_slow() const {
604 return oop_is_objArray_slow() || oop_is_typeArray_slow();
605 }
607 // Fast non-virtual versions, used by oop.inline.hpp and elsewhere:
608 #ifndef ASSERT
609 #define assert_same_query(xval, xcheck) xval
610 #else
611 private:
612 static bool assert_same_query(bool xval, bool xslow) {
613 assert(xval == xslow, "slow and fast queries agree");
614 return xval;
615 }
616 public:
617 #endif
618 inline bool oop_is_instance() const { return assert_same_query(
619 layout_helper_is_instance(layout_helper()),
620 oop_is_instance_slow()); }
621 inline bool oop_is_javaArray() const { return assert_same_query(
622 layout_helper_is_javaArray(layout_helper()),
623 oop_is_javaArray_slow()); }
624 inline bool oop_is_objArray() const { return assert_same_query(
625 layout_helper_is_objArray(layout_helper()),
626 oop_is_objArray_slow()); }
627 inline bool oop_is_typeArray() const { return assert_same_query(
628 layout_helper_is_typeArray(layout_helper()),
629 oop_is_typeArray_slow()); }
630 #undef assert_same_query
632 // Unless overridden, oop is parsable if it has a klass pointer.
633 // Parsability of an object is object specific.
634 virtual bool oop_is_parsable(oop obj) const { return true; }
636 // Unless overridden, oop is safe for concurrent GC processing
637 // after its allocation is complete. The exception to
638 // this is the case where objects are changed after allocation.
639 // Class redefinition is one of the known exceptions. During
640 // class redefinition, an allocated class can changed in order
641 // order to create a merged class (the combiniation of the
642 // old class definition that has to be perserved and the new class
643 // definition which is being created.
644 virtual bool oop_is_conc_safe(oop obj) const { return true; }
646 // Access flags
647 AccessFlags access_flags() const { return _access_flags; }
648 void set_access_flags(AccessFlags flags) { _access_flags = flags; }
650 bool is_public() const { return _access_flags.is_public(); }
651 bool is_final() const { return _access_flags.is_final(); }
652 bool is_interface() const { return _access_flags.is_interface(); }
653 bool is_abstract() const { return _access_flags.is_abstract(); }
654 bool is_super() const { return _access_flags.is_super(); }
655 bool is_synthetic() const { return _access_flags.is_synthetic(); }
656 void set_is_synthetic() { _access_flags.set_is_synthetic(); }
657 bool has_finalizer() const { return _access_flags.has_finalizer(); }
658 bool has_final_method() const { return _access_flags.has_final_method(); }
659 void set_has_finalizer() { _access_flags.set_has_finalizer(); }
660 void set_has_final_method() { _access_flags.set_has_final_method(); }
661 bool is_cloneable() const { return _access_flags.is_cloneable(); }
662 void set_is_cloneable() { _access_flags.set_is_cloneable(); }
663 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); }
664 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); }
665 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); }
666 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); }
668 // Biased locking support
669 // Note: the prototype header is always set up to be at least the
670 // prototype markOop. If biased locking is enabled it may further be
671 // biasable and have an epoch.
672 markOop prototype_header() const { return _prototype_header; }
673 // NOTE: once instances of this klass are floating around in the
674 // system, this header must only be updated at a safepoint.
675 // NOTE 2: currently we only ever set the prototype header to the
676 // biasable prototype for instanceKlasses. There is no technical
677 // reason why it could not be done for arrayKlasses aside from
678 // wanting to reduce the initial scope of this optimization. There
679 // are potential problems in setting the bias pattern for
680 // JVM-internal oops.
681 inline void set_prototype_header(markOop header);
682 static int prototype_header_offset_in_bytes() { return offset_of(Klass, _prototype_header); }
684 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; }
685 // Atomically increments biased_lock_revocation_count and returns updated value
686 int atomic_incr_biased_lock_revocation_count();
687 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; }
688 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; }
689 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; }
691 #ifdef TRACE_DEFINE_KLASS_METHODS
692 TRACE_DEFINE_KLASS_METHODS;
693 #endif
695 // garbage collection support
696 virtual void follow_weak_klass_links(
697 BoolObjectClosure* is_alive, OopClosure* keep_alive);
699 // Prefetch within oop iterators. This is a macro because we
700 // can't guarantee that the compiler will inline it. In 64-bit
701 // it generally doesn't. Signature is
702 //
703 // static void prefetch_beyond(oop* const start,
704 // oop* const end,
705 // const intx foffset,
706 // const Prefetch::style pstyle);
707 #define prefetch_beyond(start, end, foffset, pstyle) { \
708 const intx foffset_ = (foffset); \
709 const Prefetch::style pstyle_ = (pstyle); \
710 assert(foffset_ > 0, "prefetch beyond, not behind"); \
711 if (pstyle_ != Prefetch::do_none) { \
712 oop* ref = (start); \
713 if (ref < (end)) { \
714 switch (pstyle_) { \
715 case Prefetch::do_read: \
716 Prefetch::read(*ref, foffset_); \
717 break; \
718 case Prefetch::do_write: \
719 Prefetch::write(*ref, foffset_); \
720 break; \
721 default: \
722 ShouldNotReachHere(); \
723 break; \
724 } \
725 } \
726 } \
727 }
729 // iterators
730 virtual int oop_oop_iterate(oop obj, OopClosure* blk) = 0;
731 virtual int oop_oop_iterate_v(oop obj, OopClosure* blk) {
732 return oop_oop_iterate(obj, blk);
733 }
735 #ifndef SERIALGC
736 // In case we don't have a specialized backward scanner use forward
737 // iteration.
738 virtual int oop_oop_iterate_backwards_v(oop obj, OopClosure* blk) {
739 return oop_oop_iterate_v(obj, blk);
740 }
741 #endif // !SERIALGC
743 // Iterates "blk" over all the oops in "obj" (of type "this") within "mr".
744 // (I don't see why the _m should be required, but without it the Solaris
745 // C++ gives warning messages about overridings of the "oop_oop_iterate"
746 // defined above "hiding" this virtual function. (DLD, 6/20/00)) */
747 virtual int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) = 0;
748 virtual int oop_oop_iterate_v_m(oop obj, OopClosure* blk, MemRegion mr) {
749 return oop_oop_iterate_m(obj, blk, mr);
750 }
752 // Versions of the above iterators specialized to particular subtypes
753 // of OopClosure, to avoid closure virtual calls.
754 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
755 virtual int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk) { \
756 /* Default implementation reverts to general version. */ \
757 return oop_oop_iterate(obj, blk); \
758 } \
759 \
760 /* Iterates "blk" over all the oops in "obj" (of type "this") within "mr". \
761 (I don't see why the _m should be required, but without it the Solaris \
762 C++ gives warning messages about overridings of the "oop_oop_iterate" \
763 defined above "hiding" this virtual function. (DLD, 6/20/00)) */ \
764 virtual int oop_oop_iterate##nv_suffix##_m(oop obj, \
765 OopClosureType* blk, \
766 MemRegion mr) { \
767 return oop_oop_iterate_m(obj, blk, mr); \
768 }
770 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL)
771 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL)
773 #ifndef SERIALGC
774 #define Klass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
775 virtual int oop_oop_iterate_backwards##nv_suffix(oop obj, \
776 OopClosureType* blk) { \
777 /* Default implementation reverts to general version. */ \
778 return oop_oop_iterate_backwards_v(obj, blk); \
779 }
781 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL)
782 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL)
783 #endif // !SERIALGC
785 virtual void array_klasses_do(void f(klassOop k)) {}
786 virtual void with_array_klasses_do(void f(klassOop k));
788 // Return self, except for abstract classes with exactly 1
789 // implementor. Then return the 1 concrete implementation.
790 Klass *up_cast_abstract();
792 // klass name
793 Symbol* name() const { return _name; }
794 void set_name(Symbol* n);
796 friend class klassKlass;
798 public:
799 // jvm support
800 virtual jint compute_modifier_flags(TRAPS) const;
802 // JVMTI support
803 virtual jint jvmti_class_status() const;
805 // Printing
806 virtual void oop_print_value_on(oop obj, outputStream* st);
807 virtual void oop_print_on (oop obj, outputStream* st);
809 // Verification
810 virtual const char* internal_name() const = 0;
811 virtual void oop_verify_on(oop obj, outputStream* st);
812 virtual void oop_verify_old_oop(oop obj, oop* p, bool allow_dirty);
813 virtual void oop_verify_old_oop(oop obj, narrowOop* p, bool allow_dirty);
814 // tells whether obj is partially constructed (gc during class loading)
815 virtual bool oop_partially_loaded(oop obj) const { return false; }
816 virtual void oop_set_partially_loaded(oop obj) {};
818 #ifndef PRODUCT
819 void verify_vtable_index(int index);
820 #endif
821 };
824 inline oop klassOopDesc::java_mirror() const { return klass_part()->java_mirror(); }
827 #endif // SHARE_VM_OOPS_KLASS_HPP