43 #include "utilities/debug.hpp"
44 #include "utilities/macros.hpp"
45 #include "utilities/globalDefinitions.hpp"
46
47 // Implementation of all inlined member functions defined in oop.hpp
48 // We need a separate file to avoid circular references
49
50 markWord oopDesc::mark() const {
51 return Atomic::load(&_mark);
52 }
53
54 markWord oopDesc::mark_acquire() const {
55 return Atomic::load_acquire(&_mark);
56 }
57
58 markWord* oopDesc::mark_addr() const {
59 return (markWord*) &_mark;
60 }
61
62 void oopDesc::set_mark(markWord m) {
63 Atomic::store(&_mark, m);
64 }
65
66 void oopDesc::set_mark(HeapWord* mem, markWord m) {
67 *(markWord*)(((char*)mem) + mark_offset_in_bytes()) = m;
68 }
69
70 void oopDesc::release_set_mark(HeapWord* mem, markWord m) {
71 Atomic::release_store((markWord*)(((char*)mem) + mark_offset_in_bytes()), m);
72 }
73
74 void oopDesc::release_set_mark(markWord m) {
75 Atomic::release_store(&_mark, m);
76 }
77
78 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark) {
79 return Atomic::cmpxchg(&_mark, old_mark, new_mark);
80 }
81
82 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark, atomic_memory_order order) {
83 return Atomic::cmpxchg(&_mark, old_mark, new_mark, order);
84 }
85
86 markWord oopDesc::prototype_mark() const {
87 if (UseCompactObjectHeaders) {
88 return klass()->prototype_header();
89 } else {
90 return markWord::prototype();
91 }
92 }
93
94 void oopDesc::init_mark() {
95 set_mark(prototype_mark());
96 }
97
98 Klass* oopDesc::klass() const {
99 switch (ObjLayout::klass_mode()) {
100 case ObjLayout::Compact:
101 return mark().klass();
102 case ObjLayout::Compressed:
103 return CompressedKlassPointers::decode_not_null(_metadata._compressed_klass);
104 default:
105 return _metadata._klass;
106 }
107 }
108
109 Klass* oopDesc::klass_or_null() const {
110 switch (ObjLayout::klass_mode()) {
111 case ObjLayout::Compact:
112 return mark().klass_or_null();
113 case ObjLayout::Compressed:
114 return CompressedKlassPointers::decode(_metadata._compressed_klass);
115 default:
155 assert(Universe::is_bootstrapping() || (k != nullptr && k->is_klass()), "incorrect Klass");
156 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
157 char* raw_mem = ((char*)mem + klass_offset_in_bytes());
158 if (UseCompressedClassPointers) {
159 Atomic::release_store((narrowKlass*)raw_mem,
160 CompressedKlassPointers::encode_not_null(k));
161 } else {
162 Atomic::release_store((Klass**)raw_mem, k);
163 }
164 }
165
166 void oopDesc::set_klass_gap(HeapWord* mem, int v) {
167 assert(has_klass_gap(), "precondition");
168 *(int*)(((char*)mem) + klass_gap_offset_in_bytes()) = v;
169 }
170
171 bool oopDesc::is_a(Klass* k) const {
172 return klass()->is_subtype_of(k);
173 }
174
175 size_t oopDesc::size() {
176 return size_given_klass(klass());
177 }
178
179 size_t oopDesc::size_given_klass(Klass* klass) {
180 int lh = klass->layout_helper();
181 size_t s;
182
183 // lh is now a value computed at class initialization that may hint
184 // at the size. For instances, this is positive and equal to the
185 // size. For arrays, this is negative and provides log2 of the
186 // array element size. For other oops, it is zero and thus requires
187 // a virtual call.
188 //
189 // We go to all this trouble because the size computation is at the
190 // heart of phase 2 of mark-compaction, and called for every object,
191 // alive or dead. So the speed here is equal in importance to the
192 // speed of allocation.
193
194 if (lh > Klass::_lh_neutral_value) {
195 if (!Klass::layout_helper_needs_slow_path(lh)) {
196 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
197 } else {
198 s = klass->oop_size(this);
199 }
200 } else if (lh <= Klass::_lh_neutral_value) {
201 // The most common case is instances; fall through if so.
202 if (lh < Klass::_lh_neutral_value) {
203 // Second most common case is arrays. We have to fetch the
204 // length of the array, shift (multiply) it appropriately,
205 // up to wordSize, add the header, and align to object size.
206 size_t size_in_bytes;
207 size_t array_length = (size_t) ((arrayOop)this)->length();
208 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
209 size_in_bytes += Klass::layout_helper_header_size(lh);
210
211 // This code could be simplified, but by keeping array_header_in_bytes
212 // in units of bytes and doing it this way we can round up just once,
213 // skipping the intermediate round to HeapWordSize.
214 s = align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize;
215
216 assert(s == klass->oop_size(this), "wrong array object size");
217 } else {
218 // Must be zero, so bite the bullet and take the virtual call.
219 s = klass->oop_size(this);
220 }
221 }
222
223 assert(s > 0, "Oop size must be greater than zero, not %zu", s);
224 assert(is_object_aligned(s), "Oop size is not properly aligned: %zu", s);
225 return s;
226 }
227
228 bool oopDesc::is_instance() const { return klass()->is_instance_klass(); }
229 bool oopDesc::is_instanceRef() const { return klass()->is_reference_instance_klass(); }
230 bool oopDesc::is_stackChunk() const { return klass()->is_stack_chunk_instance_klass(); }
231 bool oopDesc::is_array() const { return klass()->is_array_klass(); }
232 bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); }
233 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); }
234
235 template<typename T>
236 T* oopDesc::field_addr(int offset) const { return reinterpret_cast<T*>(cast_from_oop<intptr_t>(as_oop()) + offset); }
237
238 template <typename T>
239 size_t oopDesc::field_offset(T* p) const { return pointer_delta((void*)p, (void*)this, 1); }
282 }
283
284 bool oopDesc::is_gc_marked() const {
285 return mark().is_marked();
286 }
287
288 // Used by scavengers
289 bool oopDesc::is_forwarded() const {
290 return mark().is_forwarded();
291 }
292
293 bool oopDesc::is_self_forwarded() const {
294 return mark().is_self_forwarded();
295 }
296
297 // Used by scavengers
298 void oopDesc::forward_to(oop p) {
299 assert(cast_from_oop<oopDesc*>(p) != this,
300 "must not be used for self-forwarding, use forward_to_self() instead");
301 markWord m = markWord::encode_pointer_as_mark(p);
302 assert(m.decode_pointer() == p, "encoding must be reversible");
303 set_mark(m);
304 }
305
306 void oopDesc::forward_to_self() {
307 set_mark(mark().set_self_forwarded());
308 }
309
310 oop oopDesc::cas_set_forwardee(markWord new_mark, markWord compare, atomic_memory_order order) {
311 markWord old_mark = cas_set_mark(new_mark, compare, order);
312 if (old_mark == compare) {
313 return nullptr;
314 } else {
315 assert(old_mark.is_forwarded(), "must be forwarded here");
316 return forwardee(old_mark);
317 }
318 }
319
320 oop oopDesc::forward_to_atomic(oop p, markWord compare, atomic_memory_order order) {
321 assert(cast_from_oop<oopDesc*>(p) != this,
322 "must not be used for self-forwarding, use forward_to_self_atomic() instead");
323 markWord m = markWord::encode_pointer_as_mark(p);
324 assert(forwardee(m) == p, "encoding must be reversible");
325 return cas_set_forwardee(m, compare, order);
326 }
327
328 oop oopDesc::forward_to_self_atomic(markWord old_mark, atomic_memory_order order) {
329 markWord new_mark = old_mark.set_self_forwarded();
368 if (m.has_displaced_mark_helper()) {
369 m.set_displaced_mark_helper(m.displaced_mark_helper().incr_age());
370 } else {
371 set_mark(m.incr_age());
372 }
373 }
374
375 template <typename OopClosureType>
376 void oopDesc::oop_iterate(OopClosureType* cl) {
377 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass());
378 }
379
380 template <typename OopClosureType>
381 void oopDesc::oop_iterate(OopClosureType* cl, MemRegion mr) {
382 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass(), mr);
383 }
384
385 template <typename OopClosureType>
386 size_t oopDesc::oop_iterate_size(OopClosureType* cl) {
387 Klass* k = klass();
388 size_t size = size_given_klass(k);
389 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k);
390 return size;
391 }
392
393 template <typename OopClosureType>
394 size_t oopDesc::oop_iterate_size(OopClosureType* cl, MemRegion mr) {
395 Klass* k = klass();
396 size_t size = size_given_klass(k);
397 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k, mr);
398 return size;
399 }
400
401 template <typename OopClosureType>
402 void oopDesc::oop_iterate_backwards(OopClosureType* cl) {
403 oop_iterate_backwards(cl, klass());
404 }
405
406 template <typename OopClosureType>
407 void oopDesc::oop_iterate_backwards(OopClosureType* cl, Klass* k) {
408 // In this assert, we cannot safely access the Klass* with compact headers.
409 assert(k == klass(), "wrong klass");
410 OopIteratorClosureDispatch::oop_oop_iterate_backwards(cl, this, k);
411 }
412
413 bool oopDesc::is_instanceof_or_null(oop obj, Klass* klass) {
414 return obj == nullptr || obj->klass()->is_subtype_of(klass);
415 }
416
417 intptr_t oopDesc::identity_hash() {
418 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
419 // Note: The mark must be read into local variable to avoid concurrent updates.
420 markWord mrk = mark();
421 if (mrk.is_unlocked() && !mrk.has_no_hash()) {
422 return mrk.hash();
423 } else if (mrk.is_marked()) {
424 return mrk.hash();
425 } else {
426 return slow_identity_hash();
427 }
428 }
429
430 // This checks fast simple case of whether the oop has_no_hash,
431 // to optimize JVMTI table lookup.
432 bool oopDesc::fast_no_hash_check() {
433 markWord mrk = mark_acquire();
434 assert(!mrk.is_marked(), "should never be marked");
435 return mrk.is_unlocked() && mrk.has_no_hash();
436 }
437
438 bool oopDesc::has_displaced_mark() const {
439 return mark().has_displaced_mark_helper();
440 }
441
442 markWord oopDesc::displaced_mark() const {
443 return mark().displaced_mark_helper();
444 }
445
446 void oopDesc::set_displaced_mark(markWord m) {
447 mark().set_displaced_mark_helper(m);
448 }
449
450 bool oopDesc::mark_must_be_preserved() const {
451 return mark_must_be_preserved(mark());
452 }
453
454 bool oopDesc::mark_must_be_preserved(markWord m) const {
455 return m.must_be_preserved();
456 }
457
458 #endif // SHARE_OOPS_OOP_INLINE_HPP
|
43 #include "utilities/debug.hpp"
44 #include "utilities/macros.hpp"
45 #include "utilities/globalDefinitions.hpp"
46
47 // Implementation of all inlined member functions defined in oop.hpp
48 // We need a separate file to avoid circular references
49
50 markWord oopDesc::mark() const {
51 return Atomic::load(&_mark);
52 }
53
54 markWord oopDesc::mark_acquire() const {
55 return Atomic::load_acquire(&_mark);
56 }
57
58 markWord* oopDesc::mark_addr() const {
59 return (markWord*) &_mark;
60 }
61
62 void oopDesc::set_mark(markWord m) {
63 if (UseCompactObjectHeaders) {
64 Atomic::store(reinterpret_cast<uint32_t volatile*>(&_mark), m.value32());
65 } else {
66 Atomic::store(&_mark, m);
67 }
68 }
69
70 void oopDesc::set_mark_full(markWord m) {
71 Atomic::store(&_mark, m);
72 }
73
74 void oopDesc::set_mark(HeapWord* mem, markWord m) {
75 if (UseCompactObjectHeaders) {
76 *(uint32_t*)(((char*)mem) + mark_offset_in_bytes()) = m.value32();
77 } else {
78 *(markWord*)(((char*)mem) + mark_offset_in_bytes()) = m;
79 }
80 }
81
82 void oopDesc::release_set_mark(HeapWord* mem, markWord m) {
83 if (UseCompactObjectHeaders) {
84 Atomic::release_store((uint32_t*)(((char*)mem) + mark_offset_in_bytes()), m.value32());
85 } else {
86 Atomic::release_store((markWord*)(((char*)mem) + mark_offset_in_bytes()), m);
87 }
88 }
89
90 void oopDesc::release_set_mark(markWord m) {
91 if (UseCompactObjectHeaders) {
92 Atomic::release_store(reinterpret_cast<uint32_t volatile*>(&_mark), m.value32());
93 } else {
94 Atomic::release_store(&_mark, m);
95 }
96 }
97
98 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark) {
99 return Atomic::cmpxchg(&_mark, old_mark, new_mark);
100 }
101
102 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark, atomic_memory_order order) {
103 return Atomic::cmpxchg(&_mark, old_mark, new_mark, order);
104 }
105
106 markWord oopDesc::prototype_mark() const {
107 if (UseCompactObjectHeaders) {
108 return klass()->prototype_header();
109 } else {
110 return markWord::prototype();
111 }
112 }
113
114 void oopDesc::init_mark() {
115 if (UseCompactObjectHeaders) {
116 markWord m = prototype_mark().copy_hashctrl_from(mark());
117 assert(m.is_neutral(), "must be neutral");
118 set_mark(m);
119 } else {
120 set_mark(prototype_mark());
121 }
122 }
123
124 Klass* oopDesc::klass() const {
125 switch (ObjLayout::klass_mode()) {
126 case ObjLayout::Compact:
127 return mark().klass();
128 case ObjLayout::Compressed:
129 return CompressedKlassPointers::decode_not_null(_metadata._compressed_klass);
130 default:
131 return _metadata._klass;
132 }
133 }
134
135 Klass* oopDesc::klass_or_null() const {
136 switch (ObjLayout::klass_mode()) {
137 case ObjLayout::Compact:
138 return mark().klass_or_null();
139 case ObjLayout::Compressed:
140 return CompressedKlassPointers::decode(_metadata._compressed_klass);
141 default:
181 assert(Universe::is_bootstrapping() || (k != nullptr && k->is_klass()), "incorrect Klass");
182 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
183 char* raw_mem = ((char*)mem + klass_offset_in_bytes());
184 if (UseCompressedClassPointers) {
185 Atomic::release_store((narrowKlass*)raw_mem,
186 CompressedKlassPointers::encode_not_null(k));
187 } else {
188 Atomic::release_store((Klass**)raw_mem, k);
189 }
190 }
191
192 void oopDesc::set_klass_gap(HeapWord* mem, int v) {
193 assert(has_klass_gap(), "precondition");
194 *(int*)(((char*)mem) + klass_gap_offset_in_bytes()) = v;
195 }
196
197 bool oopDesc::is_a(Klass* k) const {
198 return klass()->is_subtype_of(k);
199 }
200
201 size_t oopDesc::size_given_mark_and_klass(markWord mrk, const Klass* kls) {
202 size_t sz = base_size_given_klass(mrk, kls);
203 if (UseCompactObjectHeaders) {
204 assert(!mrk.has_displaced_mark_helper(), "must not be displaced");
205 if (mrk.is_expanded() && kls->expand_for_hash(cast_to_oop(this), mrk)) {
206 sz = align_object_size(sz + 1);
207 }
208 }
209 return sz;
210 }
211
212 size_t oopDesc::copy_size(size_t size, markWord mark) const {
213 if (UseCompactObjectHeaders) {
214 assert(!mark.has_displaced_mark_helper(), "must not be displaced");
215 Klass* klass = mark.klass();
216 if (mark.is_hashed_not_expanded() && klass->expand_for_hash(cast_to_oop(this), mark)) {
217 size = align_object_size(size + 1);
218 }
219 }
220 assert(is_object_aligned(size), "Oop size is not properly aligned: %zu", size);
221 return size;
222 }
223
224 size_t oopDesc::copy_size_cds(size_t size, markWord mark) const {
225 if (UseCompactObjectHeaders) {
226 assert(!mark.has_displaced_mark_helper(), "must not be displaced");
227 Klass* klass = mark.klass();
228 if (mark.is_hashed_not_expanded() && klass->expand_for_hash(cast_to_oop(this), mark)) {
229 size = align_object_size(size + 1);
230 }
231 if (mark.is_not_hashed_expanded() && klass->expand_for_hash(cast_to_oop(this), mark)) {
232 size = align_object_size(size - ObjectAlignmentInBytes / HeapWordSize);
233 }
234 }
235 assert(is_object_aligned(size), "Oop size is not properly aligned: %zu", size);
236 return size;
237 }
238
239 size_t oopDesc::size() {
240 return size_given_mark_and_klass(mark(), klass());
241 }
242
243 size_t oopDesc::base_size_given_klass(markWord mrk, const Klass* klass) {
244 int lh = klass->layout_helper();
245 size_t s;
246
247 // lh is now a value computed at class initialization that may hint
248 // at the size. For instances, this is positive and equal to the
249 // size. For arrays, this is negative and provides log2 of the
250 // array element size. For other oops, it is zero and thus requires
251 // a virtual call.
252 //
253 // We go to all this trouble because the size computation is at the
254 // heart of phase 2 of mark-compaction, and called for every object,
255 // alive or dead. So the speed here is equal in importance to the
256 // speed of allocation.
257
258 if (lh > Klass::_lh_neutral_value) {
259 if (!Klass::layout_helper_needs_slow_path(lh)) {
260 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
261 } else {
262 s = klass->oop_size(this, mrk);
263 }
264 } else if (lh <= Klass::_lh_neutral_value) {
265 // The most common case is instances; fall through if so.
266 if (lh < Klass::_lh_neutral_value) {
267 // Second most common case is arrays. We have to fetch the
268 // length of the array, shift (multiply) it appropriately,
269 // up to wordSize, add the header, and align to object size.
270 size_t size_in_bytes;
271 size_t array_length;
272 #ifdef _LP64
273 if (UseCompactObjectHeaders) {
274 array_length = (size_t) mrk.array_length();
275 } else
276 #endif
277 array_length = (size_t)((arrayOop)this)->length();
278
279 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
280 size_in_bytes += Klass::layout_helper_header_size(lh);
281
282 // This code could be simplified, but by keeping array_header_in_bytes
283 // in units of bytes and doing it this way we can round up just once,
284 // skipping the intermediate round to HeapWordSize.
285 s = align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize;
286 if (s != klass->oop_size(this, mrk)) {
287 tty->print_cr("length: %zu", array_length);
288 tty->print_cr("log element size: %d", Klass::layout_helper_log2_element_size(lh));
289 tty->print_cr("is_objArray: %s", BOOL_TO_STR(klass->is_objArray_klass()));
290 }
291 assert(s == klass->oop_size(this, mrk), "wrong array object size, s: %zu, oop_size: %zu", s, klass->oop_size(this, mrk));
292 } else {
293 // Must be zero, so bite the bullet and take the virtual call.
294 s = klass->oop_size(this, mrk);
295 }
296 }
297
298 assert(s > 0, "Oop size must be greater than zero, not %zu", s);
299 assert(is_object_aligned(s), "Oop size is not properly aligned: %zu", s);
300 return s;
301 }
302
303 bool oopDesc::is_instance() const { return klass()->is_instance_klass(); }
304 bool oopDesc::is_instanceRef() const { return klass()->is_reference_instance_klass(); }
305 bool oopDesc::is_stackChunk() const { return klass()->is_stack_chunk_instance_klass(); }
306 bool oopDesc::is_array() const { return klass()->is_array_klass(); }
307 bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); }
308 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); }
309
310 template<typename T>
311 T* oopDesc::field_addr(int offset) const { return reinterpret_cast<T*>(cast_from_oop<intptr_t>(as_oop()) + offset); }
312
313 template <typename T>
314 size_t oopDesc::field_offset(T* p) const { return pointer_delta((void*)p, (void*)this, 1); }
357 }
358
359 bool oopDesc::is_gc_marked() const {
360 return mark().is_marked();
361 }
362
363 // Used by scavengers
364 bool oopDesc::is_forwarded() const {
365 return mark().is_forwarded();
366 }
367
368 bool oopDesc::is_self_forwarded() const {
369 return mark().is_self_forwarded();
370 }
371
372 // Used by scavengers
373 void oopDesc::forward_to(oop p) {
374 assert(cast_from_oop<oopDesc*>(p) != this,
375 "must not be used for self-forwarding, use forward_to_self() instead");
376 markWord m = markWord::encode_pointer_as_mark(p);
377 if (UseCompactObjectHeaders && p->mark().is_expanded() && !mark().is_expanded()) {
378 m = m.set_forward_expanded();
379 }
380 assert(m.decode_pointer() == p, "encoding must be reversible");
381 set_mark_full(m);
382 }
383
384 void oopDesc::forward_to_self() {
385 set_mark(mark().set_self_forwarded());
386 }
387
388 void oopDesc::reset_forwarded() {
389 markWord m = mark();
390 if (m.is_self_forwarded()) {
391 unset_self_forwarded();
392 } else if (m.is_forwarded()) {
393 // Restore Klass* and hash-bits in the header,
394 // for correct iteration.
395 markWord fwd_mark = forwardee()->mark();
396 if (m.is_forward_expanded()) {
397 // Un-expand original object.
398 fwd_mark = fwd_mark.set_hashed_expanded();
399 }
400 set_mark_full(fwd_mark);
401 }
402 }
403
404 oop oopDesc::cas_set_forwardee(markWord new_mark, markWord compare, atomic_memory_order order) {
405 markWord old_mark = cas_set_mark(new_mark, compare, order);
406 if (old_mark == compare) {
407 return nullptr;
408 } else {
409 assert(old_mark.is_forwarded(), "must be forwarded here");
410 return forwardee(old_mark);
411 }
412 }
413
414 oop oopDesc::forward_to_atomic(oop p, markWord compare, atomic_memory_order order) {
415 assert(cast_from_oop<oopDesc*>(p) != this,
416 "must not be used for self-forwarding, use forward_to_self_atomic() instead");
417 markWord m = markWord::encode_pointer_as_mark(p);
418 assert(forwardee(m) == p, "encoding must be reversible");
419 return cas_set_forwardee(m, compare, order);
420 }
421
422 oop oopDesc::forward_to_self_atomic(markWord old_mark, atomic_memory_order order) {
423 markWord new_mark = old_mark.set_self_forwarded();
462 if (m.has_displaced_mark_helper()) {
463 m.set_displaced_mark_helper(m.displaced_mark_helper().incr_age());
464 } else {
465 set_mark(m.incr_age());
466 }
467 }
468
469 template <typename OopClosureType>
470 void oopDesc::oop_iterate(OopClosureType* cl) {
471 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass());
472 }
473
474 template <typename OopClosureType>
475 void oopDesc::oop_iterate(OopClosureType* cl, MemRegion mr) {
476 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass(), mr);
477 }
478
479 template <typename OopClosureType>
480 size_t oopDesc::oop_iterate_size(OopClosureType* cl) {
481 Klass* k = klass();
482 size_t size = size_given_mark_and_klass(mark(), k);
483 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k);
484 return size;
485 }
486
487 template <typename OopClosureType>
488 size_t oopDesc::oop_iterate_size(OopClosureType* cl, MemRegion mr) {
489 Klass* k = klass();
490 size_t size = size_given_mark_and_klass(mark(), k);
491 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k, mr);
492 return size;
493 }
494
495 template <typename OopClosureType>
496 void oopDesc::oop_iterate_backwards(OopClosureType* cl) {
497 oop_iterate_backwards(cl, klass());
498 }
499
500 template <typename OopClosureType>
501 void oopDesc::oop_iterate_backwards(OopClosureType* cl, Klass* k) {
502 // In this assert, we cannot safely access the Klass* with compact headers.
503 assert(k == klass(), "wrong klass");
504 OopIteratorClosureDispatch::oop_oop_iterate_backwards(cl, this, k);
505 }
506
507 bool oopDesc::is_instanceof_or_null(oop obj, Klass* klass) {
508 return obj == nullptr || obj->klass()->is_subtype_of(klass);
509 }
510
511 intptr_t oopDesc::identity_hash() {
512 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
513 // Note: The mark must be read into local variable to avoid concurrent updates.
514 if (UseCompactObjectHeaders) {
515 markWord mrk = mark();
516 if (mrk.is_hashed_expanded()) {
517 Klass* klass = mrk.klass();
518 return int_field(klass->hash_offset_in_bytes(cast_to_oop(this), mrk));
519 }
520 // Fall-through to slow-case.
521 } else {
522 markWord mrk = mark();
523 if (mrk.is_unlocked() && !mrk.has_no_hash()) {
524 return mrk.hash();
525 } else if (mrk.is_marked()) {
526 return mrk.hash();
527 }
528 // Fall-through to slow-case.
529 }
530 return slow_identity_hash();
531 }
532
533 // This checks fast simple case of whether the oop has_no_hash,
534 // to optimize JVMTI table lookup.
535 bool oopDesc::fast_no_hash_check() {
536 markWord mrk = mark_acquire();
537 assert(!mrk.is_marked(), "should never be marked");
538 return (UseCompactObjectHeaders || mrk.is_unlocked()) && mrk.has_no_hash();
539 }
540
541 bool oopDesc::has_displaced_mark() const {
542 return mark().has_displaced_mark_helper();
543 }
544
545 markWord oopDesc::displaced_mark() const {
546 return mark().displaced_mark_helper();
547 }
548
549 void oopDesc::set_displaced_mark(markWord m) {
550 mark().set_displaced_mark_helper(m);
551 }
552
553 bool oopDesc::mark_must_be_preserved() const {
554 return mark_must_be_preserved(mark());
555 }
556
557 bool oopDesc::mark_must_be_preserved(markWord m) const {
558 return m.must_be_preserved();
559 }
560
561 inline void oopDesc::initialize_hash_if_necessary(oop obj) {
562 if (!UseCompactObjectHeaders) {
563 return;
564 }
565 markWord m = mark();
566 assert(!m.has_displaced_mark_helper(), "must not be displaced header");
567 assert(!m.is_forwarded(), "must not be forwarded header");
568 if (m.is_hashed_not_expanded()) {
569 initialize_hash_if_necessary(obj, m.klass(), m);
570 }
571 }
572
573
574 #endif // SHARE_OOPS_OOP_INLINE_HPP
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