Mercurial > hg > truffle
annotate src/share/vm/oops/klass.hpp @ 167:feeb96a45707
6696264: assert("narrow oop can never be zero") for GCBasher & ParNewGC
Summary: decouple set_klass() with zeroing the gap when compressed.
Reviewed-by: kvn, ysr, jrose
author | coleenp |
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date | Wed, 28 May 2008 21:06:24 -0700 |
parents | ba764ed4b6f2 |
children | d1605aabd0a1 37f87013dfd8 |
rev | line source |
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0 | 1 /* |
2 * Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 // A Klass is the part of the klassOop that provides: | |
26 // 1: language level class object (method dictionary etc.) | |
27 // 2: provide vm dispatch behavior for the object | |
28 // Both functions are combined into one C++ class. The toplevel class "Klass" | |
29 // implements purpose 1 whereas all subclasses provide extra virtual functions | |
30 // for purpose 2. | |
31 | |
32 // One reason for the oop/klass dichotomy in the implementation is | |
33 // that we don't want a C++ vtbl pointer in every object. Thus, | |
34 // normal oops don't have any virtual functions. Instead, they | |
35 // forward all "virtual" functions to their klass, which does have | |
36 // a vtbl and does the C++ dispatch depending on the object's | |
37 // actual type. (See oop.inline.hpp for some of the forwarding code.) | |
38 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"! | |
39 | |
40 // Klass layout: | |
41 // [header ] klassOop | |
42 // [klass pointer ] klassOop | |
43 // [C++ vtbl ptr ] (contained in Klass_vtbl) | |
44 // [layout_helper ] | |
45 // [super_check_offset ] for fast subtype checks | |
46 // [secondary_super_cache] for fast subtype checks | |
47 // [secondary_supers ] array of 2ndary supertypes | |
48 // [primary_supers 0] | |
49 // [primary_supers 1] | |
50 // [primary_supers 2] | |
51 // ... | |
52 // [primary_supers 7] | |
53 // [java_mirror ] | |
54 // [super ] | |
55 // [name ] | |
56 // [first subklass] | |
57 // [next_sibling ] link to chain additional subklasses | |
58 // [modifier_flags] | |
59 // [access_flags ] | |
60 // [verify_count ] - not in product | |
61 // [alloc_count ] | |
62 // [last_biased_lock_bulk_revocation_time] (64 bits) | |
63 // [prototype_header] | |
64 // [biased_lock_revocation_count] | |
65 | |
66 | |
67 // Forward declarations. | |
68 class klassVtable; | |
69 class KlassHandle; | |
70 class OrderAccess; | |
71 | |
72 // Holder (or cage) for the C++ vtable of each kind of Klass. | |
73 // We want to tightly constrain the location of the C++ vtable in the overall layout. | |
74 class Klass_vtbl { | |
75 protected: | |
76 // The following virtual exists only to force creation of a C++ vtable, | |
77 // so that this class truly is the location of the vtable of all Klasses. | |
78 virtual void unused_initial_virtual() { } | |
79 | |
80 public: | |
81 // The following virtual makes Klass_vtbl play a second role as a | |
82 // factory protocol for subclasses of Klass ("sub-Klasses"). | |
83 // Here's how it works.... | |
84 // | |
85 // This VM uses metaobjects as factories for their instances. | |
86 // | |
87 // In order to initialize the C++ vtable of a new instance, its | |
88 // metaobject is forced to use the C++ placed new operator to | |
89 // allocate the instance. In a typical C++-based system, each | |
90 // sub-class would have its own factory routine which | |
91 // directly uses the placed new operator on the desired class, | |
92 // and then calls the appropriate chain of C++ constructors. | |
93 // | |
94 // However, this system uses shared code to performs the first | |
95 // allocation and initialization steps for all sub-Klasses. | |
96 // (See base_create_klass() and base_create_array_klass().) | |
97 // This does not factor neatly into a hierarchy of C++ constructors. | |
98 // Each caller of these shared "base_create" routines knows | |
99 // exactly which sub-Klass it is creating, but the shared routine | |
100 // does not, even though it must perform the actual allocation. | |
101 // | |
102 // Therefore, the caller of the shared "base_create" must wrap | |
103 // the specific placed new call in a virtual function which | |
104 // performs the actual allocation and vtable set-up. That | |
105 // virtual function is here, Klass_vtbl::allocate_permanent. | |
106 // | |
107 // The arguments to Universe::allocate_permanent() are passed | |
108 // straight through the placed new operator, which in turn | |
109 // obtains them directly from this virtual call. | |
110 // | |
111 // This virtual is called on a temporary "example instance" of the | |
112 // sub-Klass being instantiated, a C++ auto variable. The "real" | |
113 // instance created by this virtual is on the VM heap, where it is | |
114 // equipped with a klassOopDesc header. | |
115 // | |
116 // It is merely an accident of implementation that we use "example | |
117 // instances", but that is why the virtual function which implements | |
118 // each sub-Klass factory happens to be defined by the same sub-Klass | |
119 // for which it creates instances. | |
120 // | |
121 // The vtbl_value() call (see below) is used to strip away the | |
122 // accidental Klass-ness from an "example instance" and present it as | |
123 // a factory. Think of each factory object as a mere container of the | |
124 // C++ vtable for the desired sub-Klass. Since C++ does not allow | |
125 // direct references to vtables, the factory must also be delegated | |
126 // the task of allocating the instance, but the essential point is | |
127 // that the factory knows how to initialize the C++ vtable with the | |
128 // right pointer value. All other common initializations are handled | |
129 // by the shared "base_create" subroutines. | |
130 // | |
131 virtual void* allocate_permanent(KlassHandle& klass, int size, TRAPS) const = 0; | |
132 void post_new_init_klass(KlassHandle& klass, klassOop obj, int size) const; | |
133 | |
134 // Every subclass on which vtbl_value is called must include this macro. | |
135 // Delay the installation of the klassKlass pointer until after the | |
136 // the vtable for a new klass has been installed (after the call to new()). | |
137 #define DEFINE_ALLOCATE_PERMANENT(thisKlass) \ | |
138 void* allocate_permanent(KlassHandle& klass_klass, int size, TRAPS) const { \ | |
139 void* result = new(klass_klass, size, THREAD) thisKlass(); \ | |
140 if (HAS_PENDING_EXCEPTION) return NULL; \ | |
141 klassOop new_klass = ((Klass*) result)->as_klassOop(); \ | |
142 OrderAccess::storestore(); \ | |
143 post_new_init_klass(klass_klass, new_klass, size); \ | |
144 return result; \ | |
145 } | |
146 | |
147 bool null_vtbl() { return *(intptr_t*)this == 0; } | |
148 | |
149 protected: | |
150 void* operator new(size_t ignored, KlassHandle& klass, int size, TRAPS); | |
151 }; | |
152 | |
153 | |
154 class Klass : public Klass_vtbl { | |
155 friend class VMStructs; | |
156 protected: | |
157 // note: put frequently-used fields together at start of klass structure | |
158 // for better cache behavior (may not make much of a difference but sure won't hurt) | |
159 enum { _primary_super_limit = 8 }; | |
160 | |
161 // The "layout helper" is a combined descriptor of object layout. | |
162 // For klasses which are neither instance nor array, the value is zero. | |
163 // | |
164 // For instances, layout helper is a positive number, the instance size. | |
165 // This size is already passed through align_object_size and scaled to bytes. | |
166 // The low order bit is set if instances of this class cannot be | |
167 // allocated using the fastpath. | |
168 // | |
169 // For arrays, layout helper is a negative number, containing four | |
170 // distinct bytes, as follows: | |
171 // MSB:[tag, hsz, ebt, log2(esz)]:LSB | |
172 // where: | |
173 // tag is 0x80 if the elements are oops, 0xC0 if non-oops | |
174 // hsz is array header size in bytes (i.e., offset of first element) | |
175 // ebt is the BasicType of the elements | |
176 // esz is the element size in bytes | |
177 // This packed word is arranged so as to be quickly unpacked by the | |
178 // various fast paths that use the various subfields. | |
179 // | |
180 // The esz bits can be used directly by a SLL instruction, without masking. | |
181 // | |
182 // Note that the array-kind tag looks like 0x00 for instance klasses, | |
183 // since their length in bytes is always less than 24Mb. | |
184 // | |
185 // Final note: This comes first, immediately after Klass_vtbl, | |
186 // because it is frequently queried. | |
187 jint _layout_helper; | |
188 | |
189 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers | |
190 // and _primary_supers all help make fast subtype checks. See big discussion | |
191 // in doc/server_compiler/checktype.txt | |
192 // | |
193 // Where to look to observe a supertype (it is &_secondary_super_cache for | |
194 // secondary supers, else is &_primary_supers[depth()]. | |
195 juint _super_check_offset; | |
196 | |
197 public: | |
198 oop* oop_block_beg() const { return adr_secondary_super_cache(); } | |
199 oop* oop_block_end() const { return adr_next_sibling() + 1; } | |
200 | |
201 protected: | |
202 // | |
203 // The oop block. All oop fields must be declared here and only oop fields | |
204 // may be declared here. In addition, the first and last fields in this block | |
205 // must remain first and last, unless oop_block_beg() and/or oop_block_end() | |
206 // are updated. Grouping the oop fields in a single block simplifies oop | |
207 // iteration. | |
208 // | |
209 | |
210 // Cache of last observed secondary supertype | |
211 klassOop _secondary_super_cache; | |
212 // Array of all secondary supertypes | |
213 objArrayOop _secondary_supers; | |
214 // Ordered list of all primary supertypes | |
215 klassOop _primary_supers[_primary_super_limit]; | |
216 // java/lang/Class instance mirroring this class | |
217 oop _java_mirror; | |
218 // Superclass | |
219 klassOop _super; | |
220 // Class name. Instance classes: java/lang/String, etc. Array classes: [I, | |
221 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes. | |
222 symbolOop _name; | |
223 // First subclass (NULL if none); _subklass->next_sibling() is next one | |
224 klassOop _subklass; | |
225 // Sibling link (or NULL); links all subklasses of a klass | |
226 klassOop _next_sibling; | |
227 | |
228 // | |
229 // End of the oop block. | |
230 // | |
231 | |
232 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers. | |
233 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here. | |
234 | |
235 #ifndef PRODUCT | |
236 int _verify_count; // to avoid redundant verifies | |
237 #endif | |
238 | |
239 juint _alloc_count; // allocation profiling support - update klass_size_in_bytes() if moved/deleted | |
240 | |
241 // Biased locking implementation and statistics | |
242 // (the 64-bit chunk goes first, to avoid some fragmentation) | |
243 jlong _last_biased_lock_bulk_revocation_time; | |
244 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type | |
245 jint _biased_lock_revocation_count; | |
246 | |
247 public: | |
248 | |
249 // returns the enclosing klassOop | |
250 klassOop as_klassOop() const { | |
251 // see klassOop.hpp for layout. | |
252 return (klassOop) (((char*) this) - sizeof(klassOopDesc)); | |
253 } | |
254 | |
255 public: | |
256 // Allocation | |
257 const Klass_vtbl& vtbl_value() const { return *this; } // used only on "example instances" | |
258 static KlassHandle base_create_klass(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS); | |
259 static klassOop base_create_klass_oop(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS); | |
260 | |
261 // super | |
262 klassOop super() const { return _super; } | |
263 void set_super(klassOop k) { oop_store_without_check((oop*) &_super, (oop) k); } | |
264 | |
265 // initializes _super link, _primary_supers & _secondary_supers arrays | |
266 void initialize_supers(klassOop k, TRAPS); | |
267 void initialize_supers_impl1(klassOop k); | |
268 void initialize_supers_impl2(klassOop k); | |
269 | |
270 // klass-specific helper for initializing _secondary_supers | |
271 virtual objArrayOop compute_secondary_supers(int num_extra_slots, TRAPS); | |
272 | |
273 // java_super is the Java-level super type as specified by Class.getSuperClass. | |
274 virtual klassOop java_super() const { return NULL; } | |
275 | |
276 juint super_check_offset() const { return _super_check_offset; } | |
277 void set_super_check_offset(juint o) { _super_check_offset = o; } | |
278 | |
279 klassOop secondary_super_cache() const { return _secondary_super_cache; } | |
280 void set_secondary_super_cache(klassOop k) { oop_store_without_check((oop*) &_secondary_super_cache, (oop) k); } | |
281 | |
282 objArrayOop secondary_supers() const { return _secondary_supers; } | |
283 void set_secondary_supers(objArrayOop k) { oop_store_without_check((oop*) &_secondary_supers, (oop) k); } | |
284 | |
285 // Return the element of the _super chain of the given depth. | |
286 // If there is no such element, return either NULL or this. | |
287 klassOop primary_super_of_depth(juint i) const { | |
288 assert(i < primary_super_limit(), "oob"); | |
289 klassOop super = _primary_supers[i]; | |
290 assert(super == NULL || super->klass_part()->super_depth() == i, "correct display"); | |
291 return super; | |
292 } | |
293 | |
294 // Can this klass be a primary super? False for interfaces and arrays of | |
295 // interfaces. False also for arrays or classes with long super chains. | |
296 bool can_be_primary_super() const { | |
297 const juint secondary_offset = secondary_super_cache_offset_in_bytes() + sizeof(oopDesc); | |
298 return super_check_offset() != secondary_offset; | |
299 } | |
300 virtual bool can_be_primary_super_slow() const; | |
301 | |
302 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit]. | |
303 juint super_depth() const { | |
304 if (!can_be_primary_super()) { | |
305 return primary_super_limit(); | |
306 } else { | |
307 juint d = (super_check_offset() - (primary_supers_offset_in_bytes() + sizeof(oopDesc))) / sizeof(klassOop); | |
308 assert(d < primary_super_limit(), "oob"); | |
309 assert(_primary_supers[d] == as_klassOop(), "proper init"); | |
310 return d; | |
311 } | |
312 } | |
313 | |
314 // java mirror | |
315 oop java_mirror() const { return _java_mirror; } | |
316 void set_java_mirror(oop m) { oop_store((oop*) &_java_mirror, m); } | |
317 | |
318 // modifier flags | |
319 jint modifier_flags() const { return _modifier_flags; } | |
320 void set_modifier_flags(jint flags) { _modifier_flags = flags; } | |
321 | |
322 // size helper | |
323 int layout_helper() const { return _layout_helper; } | |
324 void set_layout_helper(int lh) { _layout_helper = lh; } | |
325 | |
326 // Note: for instances layout_helper() may include padding. | |
327 // Use instanceKlass::contains_field_offset to classify field offsets. | |
328 | |
329 // sub/superklass links | |
330 instanceKlass* superklass() const; | |
331 Klass* subklass() const; | |
332 Klass* next_sibling() const; | |
333 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list | |
334 void remove_from_sibling_list(); // remove receiver from sibling list | |
335 protected: // internal accessors | |
336 klassOop subklass_oop() const { return _subklass; } | |
337 klassOop next_sibling_oop() const { return _next_sibling; } | |
338 void set_subklass(klassOop s); | |
339 void set_next_sibling(klassOop s); | |
340 | |
341 oop* adr_super() const { return (oop*)&_super; } | |
342 oop* adr_primary_supers() const { return (oop*)&_primary_supers[0]; } | |
343 oop* adr_secondary_super_cache() const { return (oop*)&_secondary_super_cache; } | |
344 oop* adr_secondary_supers()const { return (oop*)&_secondary_supers; } | |
345 oop* adr_java_mirror() const { return (oop*)&_java_mirror; } | |
346 oop* adr_name() const { return (oop*)&_name; } | |
347 oop* adr_subklass() const { return (oop*)&_subklass; } | |
348 oop* adr_next_sibling() const { return (oop*)&_next_sibling; } | |
349 | |
350 public: | |
351 // Allocation profiling support | |
352 juint alloc_count() const { return _alloc_count; } | |
353 void set_alloc_count(juint n) { _alloc_count = n; } | |
354 virtual juint alloc_size() const = 0; | |
355 virtual void set_alloc_size(juint n) = 0; | |
356 | |
357 // Compiler support | |
358 static int super_offset_in_bytes() { return offset_of(Klass, _super); } | |
359 static int super_check_offset_offset_in_bytes() { return offset_of(Klass, _super_check_offset); } | |
360 static int primary_supers_offset_in_bytes(){ return offset_of(Klass, _primary_supers); } | |
361 static int secondary_super_cache_offset_in_bytes() { return offset_of(Klass, _secondary_super_cache); } | |
362 static int secondary_supers_offset_in_bytes() { return offset_of(Klass, _secondary_supers); } | |
363 static int java_mirror_offset_in_bytes() { return offset_of(Klass, _java_mirror); } | |
364 static int modifier_flags_offset_in_bytes(){ return offset_of(Klass, _modifier_flags); } | |
365 static int layout_helper_offset_in_bytes() { return offset_of(Klass, _layout_helper); } | |
366 static int access_flags_offset_in_bytes() { return offset_of(Klass, _access_flags); } | |
367 | |
368 // Unpacking layout_helper: | |
369 enum { | |
370 _lh_neutral_value = 0, // neutral non-array non-instance value | |
371 _lh_instance_slow_path_bit = 0x01, | |
372 _lh_log2_element_size_shift = BitsPerByte*0, | |
373 _lh_log2_element_size_mask = BitsPerLong-1, | |
374 _lh_element_type_shift = BitsPerByte*1, | |
375 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask | |
376 _lh_header_size_shift = BitsPerByte*2, | |
377 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask | |
378 _lh_array_tag_bits = 2, | |
379 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits, | |
380 _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30 | |
381 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30 | |
382 }; | |
383 | |
384 static int layout_helper_size_in_bytes(jint lh) { | |
385 assert(lh > (jint)_lh_neutral_value, "must be instance"); | |
386 return (int) lh & ~_lh_instance_slow_path_bit; | |
387 } | |
388 static bool layout_helper_needs_slow_path(jint lh) { | |
389 assert(lh > (jint)_lh_neutral_value, "must be instance"); | |
390 return (lh & _lh_instance_slow_path_bit) != 0; | |
391 } | |
392 static bool layout_helper_is_instance(jint lh) { | |
393 return (jint)lh > (jint)_lh_neutral_value; | |
394 } | |
395 static bool layout_helper_is_javaArray(jint lh) { | |
396 return (jint)lh < (jint)_lh_neutral_value; | |
397 } | |
398 static bool layout_helper_is_typeArray(jint lh) { | |
399 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift); | |
400 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift); | |
401 } | |
402 static bool layout_helper_is_objArray(jint lh) { | |
403 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift); | |
404 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift); | |
405 } | |
406 static int layout_helper_header_size(jint lh) { | |
407 assert(lh < (jint)_lh_neutral_value, "must be array"); | |
408 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask; | |
409 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity"); | |
410 return hsize; | |
411 } | |
412 static BasicType layout_helper_element_type(jint lh) { | |
413 assert(lh < (jint)_lh_neutral_value, "must be array"); | |
414 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask; | |
415 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity"); | |
416 return (BasicType) btvalue; | |
417 } | |
418 static int layout_helper_log2_element_size(jint lh) { | |
419 assert(lh < (jint)_lh_neutral_value, "must be array"); | |
420 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask; | |
421 assert(l2esz <= LogBitsPerLong, "sanity"); | |
422 return l2esz; | |
423 } | |
424 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) { | |
425 return (tag << _lh_array_tag_shift) | |
426 | (hsize << _lh_header_size_shift) | |
427 | ((int)etype << _lh_element_type_shift) | |
428 | (log2_esize << _lh_log2_element_size_shift); | |
429 } | |
430 static jint instance_layout_helper(jint size, bool slow_path_flag) { | |
431 return (size << LogHeapWordSize) | |
432 | (slow_path_flag ? _lh_instance_slow_path_bit : 0); | |
433 } | |
434 static int layout_helper_to_size_helper(jint lh) { | |
435 assert(lh > (jint)_lh_neutral_value, "must be instance"); | |
436 // Note that the following expression discards _lh_instance_slow_path_bit. | |
437 return lh >> LogHeapWordSize; | |
438 } | |
439 // Out-of-line version computes everything based on the etype: | |
440 static jint array_layout_helper(BasicType etype); | |
441 | |
442 // What is the maximum number of primary superclasses any klass can have? | |
443 #ifdef PRODUCT | |
444 static juint primary_super_limit() { return _primary_super_limit; } | |
445 #else | |
446 static juint primary_super_limit() { | |
447 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob"); | |
448 return FastSuperclassLimit; | |
449 } | |
450 #endif | |
451 | |
452 // vtables | |
453 virtual klassVtable* vtable() const { return NULL; } | |
454 | |
455 static int klass_size_in_bytes() { return offset_of(Klass, _alloc_count) + sizeof(juint); } // all "visible" fields | |
456 | |
457 // subclass check | |
458 bool is_subclass_of(klassOop k) const; | |
459 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it | |
460 bool is_subtype_of(klassOop k) const { | |
461 juint off = k->klass_part()->super_check_offset(); | |
462 klassOop sup = *(klassOop*)( (address)as_klassOop() + off ); | |
463 const juint secondary_offset = secondary_super_cache_offset_in_bytes() + sizeof(oopDesc); | |
464 if (sup == k) { | |
465 return true; | |
466 } else if (off != secondary_offset) { | |
467 return false; | |
468 } else { | |
469 return search_secondary_supers(k); | |
470 } | |
471 } | |
472 bool search_secondary_supers(klassOop k) const; | |
473 | |
474 // Find LCA in class heirarchy | |
475 Klass *LCA( Klass *k ); | |
476 | |
477 // Check whether reflection/jni/jvm code is allowed to instantiate this class; | |
478 // if not, throw either an Error or an Exception. | |
479 virtual void check_valid_for_instantiation(bool throwError, TRAPS); | |
480 | |
481 // Casting | |
482 static Klass* cast(klassOop k) { | |
483 assert(k->is_klass(), "cast to Klass"); | |
484 return k->klass_part(); | |
485 } | |
486 | |
487 // array copying | |
488 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS); | |
489 | |
490 // tells if the class should be initialized | |
491 virtual bool should_be_initialized() const { return false; } | |
492 // initializes the klass | |
493 virtual void initialize(TRAPS); | |
494 // lookup operation for MethodLookupCache | |
495 friend class MethodLookupCache; | |
496 virtual methodOop uncached_lookup_method(symbolOop name, symbolOop signature) const; | |
497 public: | |
498 methodOop lookup_method(symbolOop name, symbolOop signature) const { | |
499 return uncached_lookup_method(name, signature); | |
500 } | |
501 | |
502 // array class with specific rank | |
503 klassOop array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); } | |
504 | |
505 // array class with this klass as element type | |
506 klassOop array_klass(TRAPS) { return array_klass_impl(false, THREAD); } | |
507 | |
508 // These will return NULL instead of allocating on the heap: | |
509 // NB: these can block for a mutex, like other functions with TRAPS arg. | |
510 klassOop array_klass_or_null(int rank); | |
511 klassOop array_klass_or_null(); | |
512 | |
513 virtual oop protection_domain() { return NULL; } | |
514 virtual oop class_loader() const { return NULL; } | |
515 | |
516 protected: | |
517 virtual klassOop array_klass_impl(bool or_null, int rank, TRAPS); | |
518 virtual klassOop array_klass_impl(bool or_null, TRAPS); | |
519 | |
520 public: | |
521 virtual void remove_unshareable_info(); | |
522 | |
523 protected: | |
524 // computes the subtype relationship | |
525 virtual bool compute_is_subtype_of(klassOop k); | |
526 public: | |
527 // subclass accessor (here for convenience; undefined for non-klass objects) | |
528 virtual bool is_leaf_class() const { fatal("not a class"); return false; } | |
529 public: | |
530 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP | |
531 // These functions describe behavior for the oop not the KLASS. | |
532 | |
533 // actual oop size of obj in memory | |
534 virtual int oop_size(oop obj) const = 0; | |
535 | |
536 // actual oop size of this klass in memory | |
537 virtual int klass_oop_size() const = 0; | |
538 | |
539 // Returns the Java name for a class (Resource allocated) | |
540 // For arrays, this returns the name of the element with a leading '['. | |
541 // For classes, this returns the name with the package separators | |
542 // turned into '.'s. | |
543 const char* external_name() const; | |
544 // Returns the name for a class (Resource allocated) as the class | |
545 // would appear in a signature. | |
546 // For arrays, this returns the name of the element with a leading '['. | |
547 // For classes, this returns the name with a leading 'L' and a trailing ';' | |
548 // and the package separators as '/'. | |
549 virtual char* signature_name() const; | |
550 | |
551 // garbage collection support | |
552 virtual void oop_follow_contents(oop obj) = 0; | |
553 virtual int oop_adjust_pointers(oop obj) = 0; | |
554 | |
555 // Parallel Scavenge and Parallel Old | |
556 PARALLEL_GC_DECLS_PV | |
557 | |
558 public: | |
559 // type testing operations | |
560 virtual bool oop_is_instance_slow() const { return false; } | |
561 virtual bool oop_is_instanceRef() const { return false; } | |
562 virtual bool oop_is_array() const { return false; } | |
563 virtual bool oop_is_objArray_slow() const { return false; } | |
564 virtual bool oop_is_symbol() const { return false; } | |
565 virtual bool oop_is_klass() const { return false; } | |
566 virtual bool oop_is_thread() const { return false; } | |
567 virtual bool oop_is_method() const { return false; } | |
568 virtual bool oop_is_constMethod() const { return false; } | |
569 virtual bool oop_is_methodData() const { return false; } | |
570 virtual bool oop_is_constantPool() const { return false; } | |
571 virtual bool oop_is_constantPoolCache() const { return false; } | |
572 virtual bool oop_is_typeArray_slow() const { return false; } | |
573 virtual bool oop_is_arrayKlass() const { return false; } | |
574 virtual bool oop_is_objArrayKlass() const { return false; } | |
575 virtual bool oop_is_typeArrayKlass() const { return false; } | |
576 virtual bool oop_is_compiledICHolder() const { return false; } | |
577 virtual bool oop_is_instanceKlass() const { return false; } | |
578 | |
579 bool oop_is_javaArray_slow() const { | |
580 return oop_is_objArray_slow() || oop_is_typeArray_slow(); | |
581 } | |
582 | |
583 // Fast non-virtual versions, used by oop.inline.hpp and elsewhere: | |
584 #ifndef ASSERT | |
585 #define assert_same_query(xval, xcheck) xval | |
586 #else | |
587 private: | |
588 static bool assert_same_query(bool xval, bool xslow) { | |
589 assert(xval == xslow, "slow and fast queries agree"); | |
590 return xval; | |
591 } | |
592 public: | |
593 #endif | |
594 inline bool oop_is_instance() const { return assert_same_query( | |
595 layout_helper_is_instance(layout_helper()), | |
596 oop_is_instance_slow()); } | |
597 inline bool oop_is_javaArray() const { return assert_same_query( | |
598 layout_helper_is_javaArray(layout_helper()), | |
599 oop_is_javaArray_slow()); } | |
600 inline bool oop_is_objArray() const { return assert_same_query( | |
601 layout_helper_is_objArray(layout_helper()), | |
602 oop_is_objArray_slow()); } | |
603 inline bool oop_is_typeArray() const { return assert_same_query( | |
604 layout_helper_is_typeArray(layout_helper()), | |
605 oop_is_typeArray_slow()); } | |
606 #undef assert_same_query | |
607 | |
608 // Unless overridden, oop is parsable if it has a klass pointer. | |
609 virtual bool oop_is_parsable(oop obj) const { return true; } | |
610 | |
611 // Access flags | |
612 AccessFlags access_flags() const { return _access_flags; } | |
613 void set_access_flags(AccessFlags flags) { _access_flags = flags; } | |
614 | |
615 bool is_public() const { return _access_flags.is_public(); } | |
616 bool is_final() const { return _access_flags.is_final(); } | |
617 bool is_interface() const { return _access_flags.is_interface(); } | |
618 bool is_abstract() const { return _access_flags.is_abstract(); } | |
619 bool is_super() const { return _access_flags.is_super(); } | |
620 bool is_synthetic() const { return _access_flags.is_synthetic(); } | |
621 void set_is_synthetic() { _access_flags.set_is_synthetic(); } | |
622 bool has_finalizer() const { return _access_flags.has_finalizer(); } | |
623 bool has_final_method() const { return _access_flags.has_final_method(); } | |
624 void set_has_finalizer() { _access_flags.set_has_finalizer(); } | |
625 void set_has_final_method() { _access_flags.set_has_final_method(); } | |
626 bool is_cloneable() const { return _access_flags.is_cloneable(); } | |
627 void set_is_cloneable() { _access_flags.set_is_cloneable(); } | |
628 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); } | |
629 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); } | |
630 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); } | |
631 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); } | |
632 | |
633 // Biased locking support | |
634 // Note: the prototype header is always set up to be at least the | |
635 // prototype markOop. If biased locking is enabled it may further be | |
636 // biasable and have an epoch. | |
637 markOop prototype_header() const { return _prototype_header; } | |
638 // NOTE: once instances of this klass are floating around in the | |
639 // system, this header must only be updated at a safepoint. | |
640 // NOTE 2: currently we only ever set the prototype header to the | |
641 // biasable prototype for instanceKlasses. There is no technical | |
642 // reason why it could not be done for arrayKlasses aside from | |
643 // wanting to reduce the initial scope of this optimization. There | |
644 // are potential problems in setting the bias pattern for | |
645 // JVM-internal oops. | |
646 inline void set_prototype_header(markOop header); | |
647 static int prototype_header_offset_in_bytes() { return offset_of(Klass, _prototype_header); } | |
648 | |
649 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; } | |
650 // Atomically increments biased_lock_revocation_count and returns updated value | |
651 int atomic_incr_biased_lock_revocation_count(); | |
652 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; } | |
653 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; } | |
654 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; } | |
655 | |
656 | |
657 // garbage collection support | |
658 virtual void follow_weak_klass_links( | |
659 BoolObjectClosure* is_alive, OopClosure* keep_alive); | |
660 | |
661 // Prefetch within oop iterators. This is a macro because we | |
662 // can't guarantee that the compiler will inline it. In 64-bit | |
663 // it generally doesn't. Signature is | |
664 // | |
665 // static void prefetch_beyond(oop* const start, | |
666 // oop* const end, | |
667 // const intx foffset, | |
668 // const Prefetch::style pstyle); | |
669 #define prefetch_beyond(start, end, foffset, pstyle) { \ | |
670 const intx foffset_ = (foffset); \ | |
671 const Prefetch::style pstyle_ = (pstyle); \ | |
672 assert(foffset_ > 0, "prefetch beyond, not behind"); \ | |
673 if (pstyle_ != Prefetch::do_none) { \ | |
674 oop* ref = (start); \ | |
675 if (ref < (end)) { \ | |
676 switch (pstyle_) { \ | |
677 case Prefetch::do_read: \ | |
678 Prefetch::read(*ref, foffset_); \ | |
679 break; \ | |
680 case Prefetch::do_write: \ | |
681 Prefetch::write(*ref, foffset_); \ | |
682 break; \ | |
683 default: \ | |
684 ShouldNotReachHere(); \ | |
685 break; \ | |
686 } \ | |
687 } \ | |
688 } \ | |
689 } | |
690 | |
691 // iterators | |
692 virtual int oop_oop_iterate(oop obj, OopClosure* blk) = 0; | |
693 virtual int oop_oop_iterate_v(oop obj, OopClosure* blk) { | |
694 return oop_oop_iterate(obj, blk); | |
695 } | |
696 | |
697 // Iterates "blk" over all the oops in "obj" (of type "this") within "mr". | |
698 // (I don't see why the _m should be required, but without it the Solaris | |
699 // C++ gives warning messages about overridings of the "oop_oop_iterate" | |
700 // defined above "hiding" this virtual function. (DLD, 6/20/00)) */ | |
701 virtual int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) = 0; | |
702 virtual int oop_oop_iterate_v_m(oop obj, OopClosure* blk, MemRegion mr) { | |
703 return oop_oop_iterate_m(obj, blk, mr); | |
704 } | |
705 | |
706 // Versions of the above iterators specialized to particular subtypes | |
707 // of OopClosure, to avoid closure virtual calls. | |
708 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ | |
709 virtual int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk) { \ | |
710 /* Default implementation reverts to general version. */ \ | |
711 return oop_oop_iterate(obj, blk); \ | |
712 } \ | |
713 \ | |
714 /* Iterates "blk" over all the oops in "obj" (of type "this") within "mr". \ | |
715 (I don't see why the _m should be required, but without it the Solaris \ | |
716 C++ gives warning messages about overridings of the "oop_oop_iterate" \ | |
717 defined above "hiding" this virtual function. (DLD, 6/20/00)) */ \ | |
718 virtual int oop_oop_iterate##nv_suffix##_m(oop obj, \ | |
719 OopClosureType* blk, \ | |
720 MemRegion mr) { \ | |
721 return oop_oop_iterate_m(obj, blk, mr); \ | |
722 } | |
723 | |
724 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL) | |
725 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_3(Klass_OOP_OOP_ITERATE_DECL) | |
726 | |
727 virtual void array_klasses_do(void f(klassOop k)) {} | |
728 virtual void with_array_klasses_do(void f(klassOop k)); | |
729 | |
730 // Return self, except for abstract classes with exactly 1 | |
731 // implementor. Then return the 1 concrete implementation. | |
732 Klass *up_cast_abstract(); | |
733 | |
734 // klass name | |
735 symbolOop name() const { return _name; } | |
736 void set_name(symbolOop n) { oop_store_without_check((oop*) &_name, (oop) n); } | |
737 | |
738 friend class klassKlass; | |
739 | |
740 public: | |
741 // jvm support | |
742 virtual jint compute_modifier_flags(TRAPS) const; | |
743 | |
744 public: | |
745 // JVMTI support | |
746 virtual jint jvmti_class_status() const; | |
747 | |
748 #ifndef PRODUCT | |
749 public: | |
750 // Printing | |
751 virtual void oop_print_on (oop obj, outputStream* st); | |
752 virtual void oop_print_value_on(oop obj, outputStream* st); | |
753 #endif | |
754 | |
755 public: | |
756 // Verification | |
757 virtual const char* internal_name() const = 0; | |
758 virtual void oop_verify_on(oop obj, outputStream* st); | |
759 virtual void oop_verify_old_oop(oop obj, oop* p, bool allow_dirty); | |
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760 virtual void oop_verify_old_oop(oop obj, narrowOop* p, bool allow_dirty); |
0 | 761 // tells whether obj is partially constructed (gc during class loading) |
762 virtual bool oop_partially_loaded(oop obj) const { return false; } | |
763 virtual void oop_set_partially_loaded(oop obj) {}; | |
764 | |
765 #ifndef PRODUCT | |
766 void verify_vtable_index(int index); | |
767 #endif | |
768 }; |