1 /*
2 * Copyright (c) 1997, 2009, 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 // Implementation of all inlined member functions defined in oop.hpp
26 // We need a separate file to avoid circular references
27
28 inline void oopDesc::release_set_mark(markOop m) {
29 OrderAccess::release_store_ptr(&_mark, m);
30 }
31
32 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
33 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
34 }
35
36 inline klassOop oopDesc::klass() const {
37 if (UseCompressedOops) {
38 return (klassOop)decode_heap_oop_not_null(_metadata._compressed_klass);
39 } else {
40 return _metadata._klass;
41 }
42 }
43
44 inline klassOop oopDesc::klass_or_null() const volatile {
45 // can be NULL in CMS
46 if (UseCompressedOops) {
47 return (klassOop)decode_heap_oop(_metadata._compressed_klass);
48 } else {
49 return _metadata._klass;
50 }
51 }
52
53 inline int oopDesc::klass_gap_offset_in_bytes() {
54 assert(UseCompressedOops, "only applicable to compressed headers");
55 return oopDesc::klass_offset_in_bytes() + sizeof(narrowOop);
56 }
57
58 inline oop* oopDesc::klass_addr() {
59 // Only used internally and with CMS and will not work with
60 // UseCompressedOops
61 assert(!UseCompressedOops, "only supported with uncompressed oops");
62 return (oop*) &_metadata._klass;
63 }
64
65 inline narrowOop* oopDesc::compressed_klass_addr() {
66 assert(UseCompressedOops, "only called by compressed oops");
67 return (narrowOop*) &_metadata._compressed_klass;
68 }
69
70 inline void oopDesc::set_klass(klassOop k) {
71 // since klasses are promoted no store check is needed
72 assert(Universe::is_bootstrapping() || k != NULL, "must be a real klassOop");
73 assert(Universe::is_bootstrapping() || k->is_klass(), "not a klassOop");
74 if (UseCompressedOops) {
75 oop_store_without_check(compressed_klass_addr(), (oop)k);
76 } else {
77 oop_store_without_check(klass_addr(), (oop) k);
78 }
79 }
80
81 inline int oopDesc::klass_gap() const {
82 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
83 }
84
85 inline void oopDesc::set_klass_gap(int v) {
86 if (UseCompressedOops) {
87 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
88 }
89 }
90
91 inline void oopDesc::set_klass_to_list_ptr(oop k) {
92 // This is only to be used during GC, for from-space objects, so no
93 // barrier is needed.
94 if (UseCompressedOops) {
95 _metadata._compressed_klass = encode_heap_oop(k); // may be null (parnew overflow handling)
96 } else {
97 _metadata._klass = (klassOop)k;
98 }
99 }
100
101 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); }
102 inline Klass* oopDesc::blueprint() const { return klass()->klass_part(); }
103
104 inline bool oopDesc::is_a(klassOop k) const { return blueprint()->is_subtype_of(k); }
105
106 inline bool oopDesc::is_instance() const { return blueprint()->oop_is_instance(); }
107 inline bool oopDesc::is_instanceRef() const { return blueprint()->oop_is_instanceRef(); }
108 inline bool oopDesc::is_array() const { return blueprint()->oop_is_array(); }
109 inline bool oopDesc::is_objArray() const { return blueprint()->oop_is_objArray(); }
110 inline bool oopDesc::is_typeArray() const { return blueprint()->oop_is_typeArray(); }
111 inline bool oopDesc::is_javaArray() const { return blueprint()->oop_is_javaArray(); }
112 inline bool oopDesc::is_symbol() const { return blueprint()->oop_is_symbol(); }
113 inline bool oopDesc::is_klass() const { return blueprint()->oop_is_klass(); }
114 inline bool oopDesc::is_thread() const { return blueprint()->oop_is_thread(); }
115 inline bool oopDesc::is_method() const { return blueprint()->oop_is_method(); }
116 inline bool oopDesc::is_constMethod() const { return blueprint()->oop_is_constMethod(); }
117 inline bool oopDesc::is_methodData() const { return blueprint()->oop_is_methodData(); }
118 inline bool oopDesc::is_constantPool() const { return blueprint()->oop_is_constantPool(); }
119 inline bool oopDesc::is_constantPoolCache() const { return blueprint()->oop_is_constantPoolCache(); }
120 inline bool oopDesc::is_compiledICHolder() const { return blueprint()->oop_is_compiledICHolder(); }
121
122 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; }
123
124 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
125 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); }
126 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); }
127 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); }
128 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); }
129 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); }
130 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); }
131 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); }
132 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
133 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
134
135
136 // Functions for getting and setting oops within instance objects.
137 // If the oops are compressed, the type passed to these overloaded functions
138 // is narrowOop. All functions are overloaded so they can be called by
139 // template functions without conditionals (the compiler instantiates via
140 // the right type and inlines the appopriate code).
141
142 inline bool oopDesc::is_null(oop obj) { return obj == NULL; }
143 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }
144
145 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
146 // offset from the heap base. Saving the check for null can save instructions
147 // in inner GC loops so these are separated.
148
149 inline bool check_obj_alignment(oop obj) {
150 return (intptr_t)obj % MinObjAlignmentInBytes == 0;
151 }
152
153 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
154 assert(!is_null(v), "oop value can never be zero");
155 assert(check_obj_alignment(v), "Address not aligned");
156 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
157 address base = Universe::narrow_oop_base();
158 int shift = Universe::narrow_oop_shift();
159 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
160 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
161 uint64_t result = pd >> shift;
162 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
163 assert(decode_heap_oop(result) == v, "reversibility");
164 return (narrowOop)result;
165 }
166
167 inline narrowOop oopDesc::encode_heap_oop(oop v) {
168 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
169 }
170
171 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
172 assert(!is_null(v), "narrow oop value can never be zero");
173 address base = Universe::narrow_oop_base();
174 int shift = Universe::narrow_oop_shift();
175 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
176 assert(check_obj_alignment(result), "Address not aligned");
177 return result;
178 }
179
180 inline oop oopDesc::decode_heap_oop(narrowOop v) {
181 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
182 }
183
184 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
185 inline oop oopDesc::decode_heap_oop(oop v) { return v; }
186
187 // Load an oop out of the Java heap as is without decoding.
188 // Called by GC to check for null before decoding.
189 inline oop oopDesc::load_heap_oop(oop* p) { return *p; }
190 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
191
192 // Load and decode an oop out of the Java heap into a wide oop.
193 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
194 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
195 return decode_heap_oop_not_null(*p);
196 }
197
198 // Load and decode an oop out of the heap accepting null
199 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
200 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
201 return decode_heap_oop(*p);
202 }
203
204 // Store already encoded heap oop into the heap.
205 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; }
206 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
207
208 // Encode and store a heap oop.
209 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
210 *p = encode_heap_oop_not_null(v);
211 }
212 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
213
214 // Encode and store a heap oop allowing for null.
215 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
216 *p = encode_heap_oop(v);
217 }
218 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
219
220 // Store heap oop as is for volatile fields.
221 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
222 OrderAccess::release_store_ptr(p, v);
223 }
224 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
225 narrowOop v) {
226 OrderAccess::release_store(p, v);
227 }
228
229 inline void oopDesc::release_encode_store_heap_oop_not_null(
230 volatile narrowOop* p, oop v) {
231 // heap oop is not pointer sized.
232 OrderAccess::release_store(p, encode_heap_oop_not_null(v));
233 }
234
235 inline void oopDesc::release_encode_store_heap_oop_not_null(
236 volatile oop* p, oop v) {
237 OrderAccess::release_store_ptr(p, v);
238 }
239
240 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
241 oop v) {
242 OrderAccess::release_store_ptr(p, v);
243 }
244 inline void oopDesc::release_encode_store_heap_oop(
245 volatile narrowOop* p, oop v) {
246 OrderAccess::release_store(p, encode_heap_oop(v));
247 }
248
249
250 // These functions are only used to exchange oop fields in instances,
251 // not headers.
252 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
253 if (UseCompressedOops) {
254 // encode exchange value from oop to T
255 narrowOop val = encode_heap_oop(exchange_value);
256 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
257 // decode old from T to oop
258 return decode_heap_oop(old);
259 } else {
260 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
261 }
262 }
263
264 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
265 volatile HeapWord *dest,
266 oop compare_value) {
267 if (UseCompressedOops) {
268 // encode exchange and compare value from oop to T
269 narrowOop val = encode_heap_oop(exchange_value);
270 narrowOop cmp = encode_heap_oop(compare_value);
271
272 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
273 // decode old from T to oop
274 return decode_heap_oop(old);
275 } else {
276 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
277 }
278 }
279
280 // In order to put or get a field out of an instance, must first check
281 // if the field has been compressed and uncompress it.
282 inline oop oopDesc::obj_field(int offset) const {
283 return UseCompressedOops ?
284 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
285 load_decode_heap_oop(obj_field_addr<oop>(offset));
286 }
287 inline void oopDesc::obj_field_put(int offset, oop value) {
288 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
289 oop_store(obj_field_addr<oop>(offset), value);
290 }
291 inline void oopDesc::obj_field_raw_put(int offset, oop value) {
292 UseCompressedOops ?
293 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
294 encode_store_heap_oop(obj_field_addr<oop>(offset), value);
295 }
296
297 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); }
298 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; }
299
300 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); }
301 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (jint) contents; }
302
303 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); }
304 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; }
305
306 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); }
307 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; }
308
309 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); }
310 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;}
311
312 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); }
313 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; }
314
315 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); }
316 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; }
317
318 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); }
319 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
320
321 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); }
322 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
323
324 inline oop oopDesc::obj_field_acquire(int offset) const {
325 return UseCompressedOops ?
326 decode_heap_oop((narrowOop)
327 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
328 : decode_heap_oop((oop)
329 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
330 }
331 inline void oopDesc::release_obj_field_put(int offset, oop value) {
332 UseCompressedOops ?
333 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
334 oop_store((volatile oop*) obj_field_addr<oop>(offset), value);
335 }
336
337 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); }
338 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); }
339
340 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); }
341 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), contents); }
342
343 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); }
344 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); }
345
346 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); }
347 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); }
348
349 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
350 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); }
351
352 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); }
353 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); }
354
355 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); }
356 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); }
357
358 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); }
359 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
360
361 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
362 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
363
364 inline int oopDesc::size_given_klass(Klass* klass) {
365 int lh = klass->layout_helper();
366 int s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
367
368 // lh is now a value computed at class initialization that may hint
369 // at the size. For instances, this is positive and equal to the
370 // size. For arrays, this is negative and provides log2 of the
371 // array element size. For other oops, it is zero and thus requires
372 // a virtual call.
373 //
374 // We go to all this trouble because the size computation is at the
375 // heart of phase 2 of mark-compaction, and called for every object,
376 // alive or dead. So the speed here is equal in importance to the
377 // speed of allocation.
378
379 if (lh <= Klass::_lh_neutral_value) {
380 // The most common case is instances; fall through if so.
381 if (lh < Klass::_lh_neutral_value) {
382 // Second most common case is arrays. We have to fetch the
383 // length of the array, shift (multiply) it appropriately,
384 // up to wordSize, add the header, and align to object size.
385 size_t size_in_bytes;
386 #ifdef _M_IA64
387 // The Windows Itanium Aug 2002 SDK hoists this load above
388 // the check for s < 0. An oop at the end of the heap will
389 // cause an access violation if this load is performed on a non
390 // array oop. Making the reference volatile prohibits this.
391 // (%%% please explain by what magic the length is actually fetched!)
392 volatile int *array_length;
393 array_length = (volatile int *)( (intptr_t)this +
394 arrayOopDesc::length_offset_in_bytes() );
395 assert(array_length > 0, "Integer arithmetic problem somewhere");
396 // Put into size_t to avoid overflow.
397 size_in_bytes = (size_t) array_length;
398 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
399 #else
400 size_t array_length = (size_t) ((arrayOop)this)->length();
401 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
402 #endif
403 size_in_bytes += Klass::layout_helper_header_size(lh);
404
405 // This code could be simplified, but by keeping array_header_in_bytes
406 // in units of bytes and doing it this way we can round up just once,
407 // skipping the intermediate round to HeapWordSize. Cast the result
408 // of round_to to size_t to guarantee unsigned division == right shift.
409 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
410 HeapWordSize);
411
412 // UseParNewGC, UseParallelGC and UseG1GC can change the length field
413 // of an "old copy" of an object array in the young gen so it indicates
414 // the grey portion of an already copied array. This will cause the first
415 // disjunct below to fail if the two comparands are computed across such
416 // a concurrent change.
417 // UseParNewGC also runs with promotion labs (which look like int
418 // filler arrays) which are subject to changing their declared size
419 // when finally retiring a PLAB; this also can cause the first disjunct
420 // to fail for another worker thread that is concurrently walking the block
421 // offset table. Both these invariant failures are benign for their
422 // current uses; we relax the assertion checking to cover these two cases below:
423 // is_objArray() && is_forwarded() // covers first scenario above
424 // || is_typeArray() // covers second scenario above
425 // If and when UseParallelGC uses the same obj array oop stealing/chunking
426 // technique, we will need to suitably modify the assertion.
427 assert((s == klass->oop_size(this)) ||
428 (Universe::heap()->is_gc_active() &&
429 ((is_typeArray() && UseParNewGC) ||
430 (is_objArray() && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))),
431 "wrong array object size");
432 } else {
433 // Must be zero, so bite the bullet and take the virtual call.
434 s = klass->oop_size(this);
435 }
436 }
437
438 assert(s % MinObjAlignment == 0, "alignment check");
439 assert(s > 0, "Bad size calculated");
440 return s;
441 }
442
443
444 inline int oopDesc::size() {
445 return size_given_klass(blueprint());
446 }
447
448 inline bool oopDesc::is_parsable() {
449 return blueprint()->oop_is_parsable(this);
450 }
451
452 inline bool oopDesc::is_conc_safe() {
453 return blueprint()->oop_is_conc_safe(this);
454 }
455
456 inline void update_barrier_set(void* p, oop v) {
457 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
458 oopDesc::bs()->write_ref_field(p, v);
459 }
460
461 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
462 oopDesc::bs()->write_ref_field_pre(p, v);
463 }
464
465 template <class T> inline void oop_store(T* p, oop v) {
466 if (always_do_update_barrier) {
467 oop_store((volatile T*)p, v);
468 } else {
469 update_barrier_set_pre(p, v);
470 oopDesc::encode_store_heap_oop(p, v);
471 update_barrier_set((void*)p, v); // cast away type
472 }
473 }
474
475 template <class T> inline void oop_store(volatile T* p, oop v) {
476 update_barrier_set_pre((T*)p, v); // cast away volatile
477 // Used by release_obj_field_put, so use release_store_ptr.
478 oopDesc::release_encode_store_heap_oop(p, v);
479 update_barrier_set((void*)p, v); // cast away type
480 }
481
482 template <class T> inline void oop_store_without_check(T* p, oop v) {
483 // XXX YSR FIX ME!!!
484 if (always_do_update_barrier) {
485 oop_store(p, v);
486 } else {
487 assert(!Universe::heap()->barrier_set()->write_ref_needs_barrier(p, v),
488 "oop store without store check failed");
489 oopDesc::encode_store_heap_oop(p, v);
490 }
491 }
492
493 // When it absolutely has to get there.
494 template <class T> inline void oop_store_without_check(volatile T* p, oop v) {
495 // XXX YSR FIX ME!!!
496 if (always_do_update_barrier) {
497 oop_store(p, v);
498 } else {
499 assert(!Universe::heap()->barrier_set()->write_ref_needs_barrier((T*)p, v),
500 "oop store without store check failed");
501 oopDesc::release_encode_store_heap_oop(p, v);
502 }
503 }
504
505 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
506 // (without having to remember the function name this calls).
507 inline void oop_store_raw(HeapWord* addr, oop value) {
508 if (UseCompressedOops) {
509 oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
510 } else {
511 oopDesc::encode_store_heap_oop((oop*)addr, value);
512 }
513 }
514
515 // Used only for markSweep, scavenging
516 inline bool oopDesc::is_gc_marked() const {
517 return mark()->is_marked();
518 }
519
520 inline bool oopDesc::is_locked() const {
521 return mark()->is_locked();
522 }
523
524 inline bool oopDesc::is_unlocked() const {
525 return mark()->is_unlocked();
526 }
527
528 inline bool oopDesc::has_bias_pattern() const {
529 return mark()->has_bias_pattern();
530 }
531
532
533 // used only for asserts
534 inline bool oopDesc::is_oop(bool ignore_mark_word) const {
535 oop obj = (oop) this;
536 if (!check_obj_alignment(obj)) return false;
537 if (!Universe::heap()->is_in_reserved(obj)) return false;
538 // obj is aligned and accessible in heap
539 // try to find metaclass cycle safely without seg faulting on bad input
540 // we should reach klassKlassObj by following klass link at most 3 times
541 for (int i = 0; i < 3; i++) {
542 obj = obj->klass_or_null();
543 // klass should be aligned and in permspace
544 if (!check_obj_alignment(obj)) return false;
545 if (!Universe::heap()->is_in_permanent(obj)) return false;
546 }
547 if (obj != Universe::klassKlassObj()) {
548 // During a dump, the _klassKlassObj moved to a shared space.
549 if (DumpSharedSpaces && Universe::klassKlassObj()->is_shared()) {
550 return true;
551 }
552 return false;
553 }
554
555 // Header verification: the mark is typically non-NULL. If we're
556 // at a safepoint, it must not be null.
557 // Outside of a safepoint, the header could be changing (for example,
558 // another thread could be inflating a lock on this object).
559 if (ignore_mark_word) {
560 return true;
561 }
562 if (mark() != NULL) {
563 return true;
564 }
565 return !SafepointSynchronize::is_at_safepoint();
566 }
567
568
569 // used only for asserts
570 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
571 return this == NULL ? true : is_oop(ignore_mark_word);
572 }
573
574 #ifndef PRODUCT
575 // used only for asserts
576 inline bool oopDesc::is_unlocked_oop() const {
577 if (!Universe::heap()->is_in_reserved(this)) return false;
578 return mark()->is_unlocked();
579 }
580 #endif // PRODUCT
581
582 inline void oopDesc::follow_header() {
583 if (UseCompressedOops) {
584 MarkSweep::mark_and_push(compressed_klass_addr());
585 } else {
586 MarkSweep::mark_and_push(klass_addr());
587 }
588 }
589
590 inline void oopDesc::follow_contents(void) {
591 assert (is_gc_marked(), "should be marked");
592 blueprint()->oop_follow_contents(this);
593 }
594
595
596 // Used by scavengers
597
598 inline bool oopDesc::is_forwarded() const {
599 // The extra heap check is needed since the obj might be locked, in which case the
600 // mark would point to a stack location and have the sentinel bit cleared
601 return mark()->is_marked();
602 }
603
604 // Used by scavengers
605 inline void oopDesc::forward_to(oop p) {
606 assert(check_obj_alignment(p),
607 "forwarding to something not aligned");
608 assert(Universe::heap()->is_in_reserved(p),
609 "forwarding to something not in heap");
610 markOop m = markOopDesc::encode_pointer_as_mark(p);
611 assert(m->decode_pointer() == p, "encoding must be reversable");
612 set_mark(m);
613 }
614
615 // Used by parallel scavengers
616 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
617 assert(check_obj_alignment(p),
618 "forwarding to something not aligned");
619 assert(Universe::heap()->is_in_reserved(p),
620 "forwarding to something not in heap");
621 markOop m = markOopDesc::encode_pointer_as_mark(p);
622 assert(m->decode_pointer() == p, "encoding must be reversable");
623 return cas_set_mark(m, compare) == compare;
624 }
625
626 // Note that the forwardee is not the same thing as the displaced_mark.
627 // The forwardee is used when copying during scavenge and mark-sweep.
628 // It does need to clear the low two locking- and GC-related bits.
629 inline oop oopDesc::forwardee() const {
630 return (oop) mark()->decode_pointer();
631 }
632
633 inline bool oopDesc::has_displaced_mark() const {
634 return mark()->has_displaced_mark_helper();
635 }
636
637 inline markOop oopDesc::displaced_mark() const {
638 return mark()->displaced_mark_helper();
639 }
640
641 inline void oopDesc::set_displaced_mark(markOop m) {
642 mark()->set_displaced_mark_helper(m);
643 }
644
645 // The following method needs to be MT safe.
646 inline int oopDesc::age() const {
647 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
648 if (has_displaced_mark()) {
649 return displaced_mark()->age();
650 } else {
651 return mark()->age();
652 }
653 }
654
655 inline void oopDesc::incr_age() {
656 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
657 if (has_displaced_mark()) {
658 set_displaced_mark(displaced_mark()->incr_age());
659 } else {
660 set_mark(mark()->incr_age());
661 }
662 }
663
664
665 inline intptr_t oopDesc::identity_hash() {
666 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
667 // Note: The mark must be read into local variable to avoid concurrent updates.
668 markOop mrk = mark();
669 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
670 return mrk->hash();
671 } else if (mrk->is_marked()) {
672 return mrk->hash();
673 } else {
674 return slow_identity_hash();
675 }
676 }
677
678 inline void oopDesc::oop_iterate_header(OopClosure* blk) {
679 if (UseCompressedOops) {
680 blk->do_oop(compressed_klass_addr());
681 } else {
682 blk->do_oop(klass_addr());
683 }
684 }
685
686 inline void oopDesc::oop_iterate_header(OopClosure* blk, MemRegion mr) {
687 if (UseCompressedOops) {
688 if (mr.contains(compressed_klass_addr())) {
689 blk->do_oop(compressed_klass_addr());
690 }
691 } else {
692 if (mr.contains(klass_addr())) blk->do_oop(klass_addr());
693 }
694 }
695
696 inline int oopDesc::adjust_pointers() {
697 debug_only(int check_size = size());
698 int s = blueprint()->oop_adjust_pointers(this);
699 assert(s == check_size, "should be the same");
700 return s;
701 }
702
703 inline void oopDesc::adjust_header() {
704 if (UseCompressedOops) {
705 MarkSweep::adjust_pointer(compressed_klass_addr());
706 } else {
707 MarkSweep::adjust_pointer(klass_addr());
708 }
709 }
710
711 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
712 \
713 inline int oopDesc::oop_iterate(OopClosureType* blk) { \
714 SpecializationStats::record_call(); \
715 return blueprint()->oop_oop_iterate##nv_suffix(this, blk); \
716 } \
717 \
718 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
719 SpecializationStats::record_call(); \
720 return blueprint()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \
721 }
722
723 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN)
724 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN)
725
726 #ifndef SERIALGC
727 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
728 \
729 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
730 SpecializationStats::record_call(); \
731 return blueprint()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
732 }
733
734 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN)
735 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN)
736 #endif // !SERIALGC
737
738 inline bool oopDesc::is_shared() const {
739 return CompactingPermGenGen::is_shared(this);
740 }
741
742 inline bool oopDesc::is_shared_readonly() const {
743 return CompactingPermGenGen::is_shared_readonly(this);
744 }
745
746 inline bool oopDesc::is_shared_readwrite() const {
747 return CompactingPermGenGen::is_shared_readwrite(this);
748 }