1 /*
2 * Copyright (c) 1997, 2018, 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.
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23 */
24
25 #ifndef SHARE_VM_OOPS_OOP_INLINE_HPP
26 #define SHARE_VM_OOPS_OOP_INLINE_HPP
27
28 #include "gc/shared/ageTable.hpp"
29 #include "gc/shared/collectedHeap.inline.hpp"
30 #include "gc/shared/genCollectedHeap.hpp"
31 #include "gc/shared/generation.hpp"
32 #include "memory/vtBuffer.hpp"
33 #include "oops/access.inline.hpp"
34 #include "oops/arrayKlass.hpp"
35 #include "oops/arrayOop.hpp"
36 #include "oops/klass.inline.hpp"
37 #include "oops/markOop.inline.hpp"
38 #include "oops/oop.hpp"
39 #include "runtime/atomic.hpp"
40 #include "runtime/orderAccess.inline.hpp"
41 #include "runtime/os.hpp"
42 #include "utilities/align.hpp"
43 #include "utilities/macros.hpp"
44
45 // Implementation of all inlined member functions defined in oop.hpp
46 // We need a separate file to avoid circular references
47
48 void oopDesc::release_set_mark(markOop m) {
49 OrderAccess::release_store(&_mark, m);
50 }
51
52 markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
53 return Atomic::cmpxchg(new_mark, &_mark, old_mark);
54 }
55
56 void oopDesc::init_mark() {
57 set_mark(markOopDesc::prototype_for_object(this));
58 }
59
60 Klass* oopDesc::klass() const {
61 if (UseCompressedClassPointers) {
62 return Klass::decode_klass_not_null(_metadata._compressed_klass);
63 } else {
64 return _metadata._klass;
65 }
66 }
67
68 Klass* oopDesc::klass_or_null() const volatile {
69 if (UseCompressedClassPointers) {
70 return Klass::decode_klass(_metadata._compressed_klass);
71 } else {
72 return _metadata._klass;
73 }
74 }
75
76 Klass* oopDesc::klass_or_null_acquire() const volatile {
77 if (UseCompressedClassPointers) {
78 // Workaround for non-const load_acquire parameter.
79 const volatile narrowKlass* addr = &_metadata._compressed_klass;
80 volatile narrowKlass* xaddr = const_cast<volatile narrowKlass*>(addr);
81 return Klass::decode_klass(OrderAccess::load_acquire(xaddr));
82 } else {
83 return OrderAccess::load_acquire(&_metadata._klass);
84 }
85 }
86
87 Klass** oopDesc::klass_addr() {
88 // Only used internally and with CMS and will not work with
89 // UseCompressedOops
90 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers");
91 return (Klass**) &_metadata._klass;
92 }
93
94 narrowKlass* oopDesc::compressed_klass_addr() {
95 assert(UseCompressedClassPointers, "only called by compressed klass pointers");
96 return &_metadata._compressed_klass;
97 }
98
99 // oop only test (does not load klass)
100 bool oopDesc::klass_is_value_type() {
101 if (UseCompressedClassPointers) {
102 return Klass::decode_ptr_is_value_type(_metadata._compressed_klass);
103 } else {
104 return Klass::ptr_is_value_type(_metadata._klass);
105 }
106 }
107
108
109 #define CHECK_SET_KLASS(k) \
110 do { \
111 assert(Universe::is_bootstrapping() || k != NULL, "NULL Klass"); \
112 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass"); \
113 assert(!EnableValhalla || (k->is_value() && Klass::ptr_is_value_type(k)) \
114 || (!k->is_value() && !Klass::ptr_is_value_type(k)), \
115 "Klass value encoding"); \
116 } while (0)
117
118 void oopDesc::set_klass(Klass* k) {
119 CHECK_SET_KLASS(k);
120 if (UseCompressedClassPointers) {
121 *compressed_klass_addr() = Klass::encode_klass_not_null(k);
122 } else {
123 *klass_addr() = k;
124 }
125 }
126
127 void oopDesc::release_set_klass(Klass* k) {
128 CHECK_SET_KLASS(k);
129 if (UseCompressedClassPointers) {
130 OrderAccess::release_store(compressed_klass_addr(),
131 Klass::encode_klass_not_null(k));
132 } else {
133 OrderAccess::release_store(klass_addr(), k);
134 }
135 }
136
137 #undef CHECK_SET_KLASS
138
139 int oopDesc::klass_gap() const {
140 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
141 }
142
143 void oopDesc::set_klass_gap(int v) {
144 if (UseCompressedClassPointers) {
145 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
146 }
147 }
148
149 void oopDesc::set_klass_to_list_ptr(oop k) {
150 // This is only to be used during GC, for from-space objects, so no
151 // barrier is needed.
152 if (UseCompressedClassPointers) {
153 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling)
154 } else {
155 _metadata._klass = (Klass*)(address)k;
156 }
157 }
158
159 oop oopDesc::list_ptr_from_klass() {
160 // This is only to be used during GC, for from-space objects.
161 if (UseCompressedClassPointers) {
162 return decode_heap_oop((narrowOop)_metadata._compressed_klass);
163 } else {
164 // Special case for GC
165 return (oop)(address)_metadata._klass;
166 }
167 }
168
169 bool oopDesc::is_a(Klass* k) const {
170 return klass()->is_subtype_of(k);
171 }
172
173 int oopDesc::size() {
174 return size_given_klass(klass());
175 }
176
177 int oopDesc::size_given_klass(Klass* klass) {
178 int lh = klass->layout_helper();
179 int s;
180
181 // lh is now a value computed at class initialization that may hint
182 // at the size. For instances, this is positive and equal to the
183 // size. For arrays, this is negative and provides log2 of the
184 // array element size. For other oops, it is zero and thus requires
185 // a virtual call.
186 //
187 // We go to all this trouble because the size computation is at the
188 // heart of phase 2 of mark-compaction, and called for every object,
189 // alive or dead. So the speed here is equal in importance to the
190 // speed of allocation.
191
192 if (lh > Klass::_lh_neutral_value) {
193 if (!Klass::layout_helper_needs_slow_path(lh)) {
194 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
195 } else {
196 s = klass->oop_size(this);
197 }
198 } else if (lh <= Klass::_lh_neutral_value) {
199 // The most common case is instances; fall through if so.
200 if (lh < Klass::_lh_neutral_value) {
201 // Second most common case is arrays. We have to fetch the
202 // length of the array, shift (multiply) it appropriately,
203 // up to wordSize, add the header, and align to object size.
204 size_t size_in_bytes;
205 size_t array_length = (size_t) ((arrayOop)this)->length();
206 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
207 size_in_bytes += Klass::layout_helper_header_size(lh);
208
209 // This code could be simplified, but by keeping array_header_in_bytes
210 // in units of bytes and doing it this way we can round up just once,
211 // skipping the intermediate round to HeapWordSize.
212 s = (int)(align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize);
213
214 // ParNew (used by CMS), UseParallelGC and UseG1GC can change the length field
215 // of an "old copy" of an object array in the young gen so it indicates
216 // the grey portion of an already copied array. This will cause the first
217 // disjunct below to fail if the two comparands are computed across such
218 // a concurrent change.
219 // ParNew also runs with promotion labs (which look like int
220 // filler arrays) which are subject to changing their declared size
221 // when finally retiring a PLAB; this also can cause the first disjunct
222 // to fail for another worker thread that is concurrently walking the block
223 // offset table. Both these invariant failures are benign for their
224 // current uses; we relax the assertion checking to cover these two cases below:
225 // is_objArray() && is_forwarded() // covers first scenario above
226 // || is_typeArray() // covers second scenario above
227 // If and when UseParallelGC uses the same obj array oop stealing/chunking
228 // technique, we will need to suitably modify the assertion.
229 assert((s == klass->oop_size(this)) ||
230 (Universe::heap()->is_gc_active() &&
231 ((is_typeArray() && UseConcMarkSweepGC) ||
232 (is_objArray() && is_forwarded() && (UseConcMarkSweepGC || UseParallelGC || UseG1GC)))),
233 "wrong array object size");
234 } else {
235 // Must be zero, so bite the bullet and take the virtual call.
236 s = klass->oop_size(this);
237 }
238 }
239
240 assert(s > 0, "Oop size must be greater than zero, not %d", s);
241 assert(is_object_aligned(s), "Oop size is not properly aligned: %d", s);
242 return s;
243 }
244
245 bool oopDesc::is_instance() const { return klass()->is_instance_klass(); }
246 bool oopDesc::is_array() const { return klass()->is_array_klass(); }
247 bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); }
248 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); }
249 bool oopDesc::is_value() const { return klass()->is_value(); }
250 bool oopDesc::is_valueArray() const { return klass()->is_valueArray_klass(); }
251
252 void* oopDesc::field_addr_raw(int offset) const { return reinterpret_cast<void*>(cast_from_oop<intptr_t>(as_oop()) + offset); }
253 void* oopDesc::field_addr(int offset) const { return Access<>::resolve(as_oop())->field_addr_raw(offset); }
254
255 template <class T>
256 T* oopDesc::obj_field_addr_raw(int offset) const { return (T*) field_addr_raw(offset); }
257
258 // Functions for getting and setting oops within instance objects.
259 // If the oops are compressed, the type passed to these overloaded functions
260 // is narrowOop. All functions are overloaded so they can be called by
261 // template functions without conditionals (the compiler instantiates via
262 // the right type and inlines the appopriate code).
263
264 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
265 // offset from the heap base. Saving the check for null can save instructions
266 // in inner GC loops so these are separated.
267
268 inline bool check_obj_alignment(oop obj) {
269 return (cast_from_oop<intptr_t>(obj) & MinObjAlignmentInBytesMask) == 0;
270 }
271
272 oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
273 assert(!is_null(v), "narrow oop value can never be zero");
274 address base = Universe::narrow_oop_base();
275 int shift = Universe::narrow_oop_shift();
276 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
277 assert(check_obj_alignment(result), "address not aligned: " INTPTR_FORMAT, p2i((void*) result));
278 return result;
279 }
280
281 oop oopDesc::decode_heap_oop(narrowOop v) {
282 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
283 }
284
285 narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
286 assert(!is_null(v), "oop value can never be zero");
287 assert(check_obj_alignment(v), "Address not aligned");
288 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
289 address base = Universe::narrow_oop_base();
290 int shift = Universe::narrow_oop_shift();
291 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
292 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
293 uint64_t result = pd >> shift;
294 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
295 assert(decode_heap_oop(result) == v, "reversibility");
296 return (narrowOop)result;
297 }
298
299 narrowOop oopDesc::encode_heap_oop(oop v) {
300 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
301 }
302
303 narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
304 oop oopDesc::load_heap_oop(oop* p) { return *p; }
305
306 void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
307 void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; }
308
309 // Load and decode an oop out of the Java heap into a wide oop.
310 oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
311 return decode_heap_oop_not_null(load_heap_oop(p));
312 }
313
314 // Load and decode an oop out of the heap accepting null
315 oop oopDesc::load_decode_heap_oop(narrowOop* p) {
316 return decode_heap_oop(load_heap_oop(p));
317 }
318
319 oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
320 oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
321
322 void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
323 void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
324
325 // Encode and store a heap oop.
326 void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
327 *p = encode_heap_oop_not_null(v);
328 }
329
330 // Encode and store a heap oop allowing for null.
331 void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
332 *p = encode_heap_oop(v);
333 }
334
335 template <DecoratorSet decorators>
336 inline oop oopDesc::obj_field_access(int offset) const { return HeapAccess<decorators>::oop_load_at(as_oop(), offset); }
337 inline oop oopDesc::obj_field(int offset) const { return HeapAccess<>::oop_load_at(as_oop(), offset); }
338
339 inline void oopDesc::obj_field_put(int offset, oop value) { HeapAccess<>::oop_store_at(as_oop(), offset, value); }
340
341 inline jbyte oopDesc::byte_field(int offset) const { return HeapAccess<>::load_at(as_oop(), offset); }
342 inline void oopDesc::byte_field_put(int offset, jbyte value) { HeapAccess<>::store_at(as_oop(), offset, value); }
343
344 inline jchar oopDesc::char_field(int offset) const { return HeapAccess<>::load_at(as_oop(), offset); }
345 inline void oopDesc::char_field_put(int offset, jchar value) { HeapAccess<>::store_at(as_oop(), offset, value); }
346
347 inline jboolean oopDesc::bool_field(int offset) const { return HeapAccess<>::load_at(as_oop(), offset); }
348 inline void oopDesc::bool_field_put(int offset, jboolean value) { HeapAccess<>::store_at(as_oop(), offset, jboolean(value & 1)); }
349
350 inline jshort oopDesc::short_field(int offset) const { return HeapAccess<>::load_at(as_oop(), offset); }
351 inline void oopDesc::short_field_put(int offset, jshort value) { HeapAccess<>::store_at(as_oop(), offset, value); }
352
353 inline jint oopDesc::int_field(int offset) const { return HeapAccess<>::load_at(as_oop(), offset); }
354 inline void oopDesc::int_field_put(int offset, jint value) { HeapAccess<>::store_at(as_oop(), offset, value); }
355
356 inline jlong oopDesc::long_field(int offset) const { return HeapAccess<>::load_at(as_oop(), offset); }
357 inline void oopDesc::long_field_put(int offset, jlong value) { HeapAccess<>::store_at(as_oop(), offset, value); }
358
359 inline jfloat oopDesc::float_field(int offset) const { return HeapAccess<>::load_at(as_oop(), offset); }
360 inline void oopDesc::float_field_put(int offset, jfloat value) { HeapAccess<>::store_at(as_oop(), offset, value); }
361
362 inline jdouble oopDesc::double_field(int offset) const { return HeapAccess<>::load_at(as_oop(), offset); }
363 inline void oopDesc::double_field_put(int offset, jdouble value) { HeapAccess<>::store_at(as_oop(), offset, value); }
364
365 bool oopDesc::is_locked() const {
366 return mark()->is_locked();
367 }
368
369 bool oopDesc::is_unlocked() const {
370 return mark()->is_unlocked();
371 }
372
373 bool oopDesc::has_bias_pattern() const {
374 return mark()->has_bias_pattern();
375 }
376
377
378 // Used only for markSweep, scavenging
379 bool oopDesc::is_gc_marked() const {
380 return mark()->is_marked();
381 }
382
383 bool oopDesc::is_scavengable() const {
384 return Universe::heap()->is_scavengable(oop(const_cast<oopDesc*>(this)));
385 }
386
387 // Used by scavengers
388 bool oopDesc::is_forwarded() const {
389 // The extra heap check is needed since the obj might be locked, in which case the
390 // mark would point to a stack location and have the sentinel bit cleared
391 return mark()->is_marked();
392 }
393
394 // Used by scavengers
395 void oopDesc::forward_to(oop p) {
396 assert(check_obj_alignment(p),
397 "forwarding to something not aligned");
398 assert(Universe::heap()->is_in_reserved(p),
399 "forwarding to something not in heap");
400 assert(!is_archive_object(oop(this)) &&
401 !is_archive_object(p),
402 "forwarding archive object");
403 markOop m = markOopDesc::encode_pointer_as_mark(p);
404 assert(m->decode_pointer() == p, "encoding must be reversable");
405 set_mark(m);
406 }
407
408 // Used by parallel scavengers
409 bool oopDesc::cas_forward_to(oop p, markOop compare) {
410 assert(check_obj_alignment(p),
411 "forwarding to something not aligned");
412 assert(Universe::heap()->is_in_reserved(p),
413 "forwarding to something not in heap");
414 markOop m = markOopDesc::encode_pointer_as_mark(p);
415 assert(m->decode_pointer() == p, "encoding must be reversable");
416 return cas_set_mark(m, compare) == compare;
417 }
418
419 #if INCLUDE_ALL_GCS
420 oop oopDesc::forward_to_atomic(oop p) {
421 markOop oldMark = mark();
422 markOop forwardPtrMark = markOopDesc::encode_pointer_as_mark(p);
423 markOop curMark;
424
425 assert(forwardPtrMark->decode_pointer() == p, "encoding must be reversable");
426 assert(sizeof(markOop) == sizeof(intptr_t), "CAS below requires this.");
427
428 while (!oldMark->is_marked()) {
429 curMark = Atomic::cmpxchg(forwardPtrMark, &_mark, oldMark);
430 assert(is_forwarded(), "object should have been forwarded");
431 if (curMark == oldMark) {
432 return NULL;
433 }
434 // If the CAS was unsuccessful then curMark->is_marked()
435 // should return true as another thread has CAS'd in another
436 // forwarding pointer.
437 oldMark = curMark;
438 }
439 return forwardee();
440 }
441 #endif
442
443 // Note that the forwardee is not the same thing as the displaced_mark.
444 // The forwardee is used when copying during scavenge and mark-sweep.
445 // It does need to clear the low two locking- and GC-related bits.
446 oop oopDesc::forwardee() const {
447 return (oop) mark()->decode_pointer();
448 }
449
450 // The following method needs to be MT safe.
451 uint oopDesc::age() const {
452 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
453 if (has_displaced_mark()) {
454 return displaced_mark()->age();
455 } else {
456 return mark()->age();
457 }
458 }
459
460 void oopDesc::incr_age() {
461 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
462 if (has_displaced_mark()) {
463 set_displaced_mark(displaced_mark()->incr_age());
464 } else {
465 set_mark(mark()->incr_age());
466 }
467 }
468
469 #if INCLUDE_ALL_GCS
470 void oopDesc::pc_follow_contents(ParCompactionManager* cm) {
471 klass()->oop_pc_follow_contents(this, cm);
472 }
473
474 void oopDesc::pc_update_contents(ParCompactionManager* cm) {
475 Klass* k = klass();
476 if (!k->is_typeArray_klass()) {
477 // It might contain oops beyond the header, so take the virtual call.
478 k->oop_pc_update_pointers(this, cm);
479 }
480 // Else skip it. The TypeArrayKlass in the header never needs scavenging.
481 }
482
483 void oopDesc::ps_push_contents(PSPromotionManager* pm) {
484 Klass* k = klass();
485 if (!k->is_typeArray_klass()) {
486 // It might contain oops beyond the header, so take the virtual call.
487 k->oop_ps_push_contents(this, pm);
488 }
489 // Else skip it. The TypeArrayKlass in the header never needs scavenging.
490 }
491 #endif // INCLUDE_ALL_GCS
492
493 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
494 \
495 void oopDesc::oop_iterate(OopClosureType* blk) { \
496 klass()->oop_oop_iterate##nv_suffix(this, blk); \
497 } \
498 \
499 void oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
500 klass()->oop_oop_iterate_bounded##nv_suffix(this, blk, mr); \
501 }
502
503 #define OOP_ITERATE_SIZE_DEFN(OopClosureType, nv_suffix) \
504 \
505 int oopDesc::oop_iterate_size(OopClosureType* blk) { \
506 Klass* k = klass(); \
507 int size = size_given_klass(k); \
508 k->oop_oop_iterate##nv_suffix(this, blk); \
509 return size; \
510 } \
511 \
512 int oopDesc::oop_iterate_size(OopClosureType* blk, MemRegion mr) { \
513 Klass* k = klass(); \
514 int size = size_given_klass(k); \
515 k->oop_oop_iterate_bounded##nv_suffix(this, blk, mr); \
516 return size; \
517 }
518
519 int oopDesc::oop_iterate_no_header(OopClosure* blk) {
520 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
521 // the do_oop calls, but turns off all other features in ExtendedOopClosure.
522 NoHeaderExtendedOopClosure cl(blk);
523 return oop_iterate_size(&cl);
524 }
525
526 int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
527 NoHeaderExtendedOopClosure cl(blk);
528 return oop_iterate_size(&cl, mr);
529 }
530
531 #if INCLUDE_ALL_GCS
532 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
533 \
534 inline void oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
535 klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
536 }
537 #else
538 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)
539 #endif // INCLUDE_ALL_GCS
540
541 #define ALL_OOPDESC_OOP_ITERATE(OopClosureType, nv_suffix) \
542 OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
543 OOP_ITERATE_SIZE_DEFN(OopClosureType, nv_suffix) \
544 OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)
545
546 ALL_OOP_OOP_ITERATE_CLOSURES_1(ALL_OOPDESC_OOP_ITERATE)
547 ALL_OOP_OOP_ITERATE_CLOSURES_2(ALL_OOPDESC_OOP_ITERATE)
548
549 intptr_t oopDesc::identity_hash() {
550 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
551 // Note: The mark must be read into local variable to avoid concurrent updates.
552 markOop mrk = mark();
553 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
554 return mrk->hash();
555 } else if (mrk->is_marked()) {
556 return mrk->hash();
557 } else {
558 return slow_identity_hash();
559 }
560 }
561
562 bool oopDesc::has_displaced_mark() const {
563 return mark()->has_displaced_mark_helper();
564 }
565
566 markOop oopDesc::displaced_mark() const {
567 return mark()->displaced_mark_helper();
568 }
569
570 void oopDesc::set_displaced_mark(markOop m) {
571 mark()->set_displaced_mark_helper(m);
572 }
573
574 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP