42 #include "utilities/align.hpp"
43 #include "utilities/debug.hpp"
44 #include "utilities/globalDefinitions.hpp"
45 #include "utilities/macros.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 void* oopDesc::base_addr() { return this; }
51 const void* oopDesc::base_addr() const { return this; }
52
53 markWord oopDesc::mark() const {
54 return AtomicAccess::load(&_mark);
55 }
56
57 markWord oopDesc::mark_acquire() const {
58 return AtomicAccess::load_acquire(&_mark);
59 }
60
61 void oopDesc::set_mark(markWord m) {
62 AtomicAccess::store(&_mark, m);
63 }
64
65 void oopDesc::set_mark(HeapWord* mem, markWord m) {
66 *(markWord*)(((char*)mem) + mark_offset_in_bytes()) = m;
67 }
68
69 void oopDesc::release_set_mark(HeapWord* mem, markWord m) {
70 AtomicAccess::release_store((markWord*)(((char*)mem) + mark_offset_in_bytes()), m);
71 }
72
73 void oopDesc::release_set_mark(markWord m) {
74 AtomicAccess::release_store(&_mark, m);
75 }
76
77 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark) {
78 return AtomicAccess::cmpxchg(&_mark, old_mark, new_mark);
79 }
80
81 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark, atomic_memory_order order) {
82 return AtomicAccess::cmpxchg(&_mark, old_mark, new_mark, order);
83 }
84
85 markWord oopDesc::prototype_mark() const {
86 if (UseCompactObjectHeaders) {
87 return klass()->prototype_header();
88 } else {
89 return markWord::prototype();
90 }
91 }
92
93 void oopDesc::init_mark() {
94 set_mark(prototype_mark());
95 }
96
97 Klass* oopDesc::klass() const {
98 return CompressedKlassPointers::decode_not_null(narrow_klass());
99 }
100
101 Klass* oopDesc::klass_or_null() const {
102 return CompressedKlassPointers::decode(narrow_klass());
103 }
104
105 Klass* oopDesc::klass_or_null_acquire() const {
106 return CompressedKlassPointers::decode(narrow_klass_acquire());
107 }
108
109 Klass* oopDesc::klass_without_asserts() const {
110 return CompressedKlassPointers::decode_without_asserts(narrow_klass());
111 }
112
113 narrowKlass oopDesc::narrow_klass() const {
114 switch (ObjLayout::klass_mode()) {
115 case ObjLayout::Compact:
116 return mark().narrow_klass();
137 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
138 _compressed_klass = CompressedKlassPointers::encode_not_null(k);
139 }
140
141 void oopDesc::release_set_klass(HeapWord* mem, Klass* k) {
142 assert(Universe::is_bootstrapping() || (k != nullptr && k->is_klass()), "incorrect Klass");
143 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
144 char* raw_mem = ((char*)mem + klass_offset_in_bytes());
145 AtomicAccess::release_store((narrowKlass*)raw_mem, CompressedKlassPointers::encode_not_null(k));
146 }
147
148 void oopDesc::set_klass_gap(HeapWord* mem, int v) {
149 assert(has_klass_gap(), "precondition");
150 *(int*)(((char*)mem) + klass_gap_offset_in_bytes()) = v;
151 }
152
153 bool oopDesc::is_a(Klass* k) const {
154 return klass()->is_subtype_of(k);
155 }
156
157 size_t oopDesc::size() {
158 return size_given_klass(klass());
159 }
160
161 size_t oopDesc::size_given_klass(Klass* klass) {
162 int lh = klass->layout_helper();
163 size_t s;
164
165 // lh is now a value computed at class initialization that may hint
166 // at the size. For instances, this is positive and equal to the
167 // size. For arrays, this is negative and provides log2 of the
168 // array element size. For other oops, it is zero and thus requires
169 // a virtual call.
170 //
171 // We go to all this trouble because the size computation is at the
172 // heart of phase 2 of mark-compaction, and called for every object,
173 // alive or dead. So the speed here is equal in importance to the
174 // speed of allocation.
175
176 if (lh > Klass::_lh_neutral_value) {
177 if (!Klass::layout_helper_needs_slow_path(lh)) {
178 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
179 } else {
180 s = klass->oop_size(this);
181 }
182 } else if (lh <= Klass::_lh_neutral_value) {
183 // The most common case is instances; fall through if so.
184 if (lh < Klass::_lh_neutral_value) {
185 // Second most common case is arrays. We have to fetch the
186 // length of the array, shift (multiply) it appropriately,
187 // up to wordSize, add the header, and align to object size.
188 size_t size_in_bytes;
189 size_t array_length = (size_t) ((arrayOop)this)->length();
190 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
191 size_in_bytes += Klass::layout_helper_header_size(lh);
192
193 // This code could be simplified, but by keeping array_header_in_bytes
194 // in units of bytes and doing it this way we can round up just once,
195 // skipping the intermediate round to HeapWordSize.
196 s = align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize;
197
198 assert(s == klass->oop_size(this), "wrong array object size");
199 } else {
200 // Must be zero, so bite the bullet and take the virtual call.
201 s = klass->oop_size(this);
202 }
203 }
204
205 assert(s > 0, "Oop size must be greater than zero, not %zu", s);
206 assert(is_object_aligned(s), "Oop size is not properly aligned: %zu", s);
207 return s;
208 }
209
210 bool oopDesc::is_instance() const { return klass()->is_instance_klass(); }
211 bool oopDesc::is_instanceRef() const { return klass()->is_reference_instance_klass(); }
212 bool oopDesc::is_stackChunk() const { return klass()->is_stack_chunk_instance_klass(); }
213 bool oopDesc::is_array() const { return klass()->is_array_klass(); }
214 bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); }
215 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); }
216
217 template<typename T>
218 T* oopDesc::field_addr(int offset) const { return reinterpret_cast<T*>(cast_from_oop<intptr_t>(as_oop()) + offset); }
219
220 template <typename T>
221 size_t oopDesc::field_offset(T* p) const { return pointer_delta((void*)p, (void*)this, 1); }
264 }
265
266 bool oopDesc::is_gc_marked() const {
267 return mark().is_marked();
268 }
269
270 // Used by scavengers
271 bool oopDesc::is_forwarded() const {
272 return mark().is_forwarded();
273 }
274
275 bool oopDesc::is_self_forwarded() const {
276 return mark().is_self_forwarded();
277 }
278
279 // Used by scavengers
280 void oopDesc::forward_to(oop p) {
281 assert(cast_from_oop<oopDesc*>(p) != this,
282 "must not be used for self-forwarding, use forward_to_self() instead");
283 markWord m = markWord::encode_pointer_as_mark(p);
284 assert(m.decode_pointer() == p, "encoding must be reversible");
285 set_mark(m);
286 }
287
288 void oopDesc::forward_to_self() {
289 set_mark(mark().set_self_forwarded());
290 }
291
292 oop oopDesc::cas_set_forwardee(markWord new_mark, markWord compare, atomic_memory_order order) {
293 markWord old_mark = cas_set_mark(new_mark, compare, order);
294 if (old_mark == compare) {
295 return nullptr;
296 } else {
297 assert(old_mark.is_forwarded(), "must be forwarded here");
298 return forwardee(old_mark);
299 }
300 }
301
302 oop oopDesc::forward_to_atomic(oop p, markWord compare, atomic_memory_order order) {
303 assert(cast_from_oop<oopDesc*>(p) != this,
304 "must not be used for self-forwarding, use forward_to_self_atomic() instead");
305 markWord m = markWord::encode_pointer_as_mark(p);
306 assert(forwardee(m) == p, "encoding must be reversible");
307 return cas_set_forwardee(m, compare, order);
308 }
309
310 oop oopDesc::forward_to_self_atomic(markWord old_mark, atomic_memory_order order) {
311 markWord new_mark = old_mark.set_self_forwarded();
312 assert(forwardee(new_mark) == cast_to_oop(this), "encoding must be reversible");
313 return cas_set_forwardee(new_mark, old_mark, order);
314 }
315
316 oop oopDesc::forwardee(markWord mark) const {
317 assert(mark.is_forwarded(), "only decode when actually forwarded");
318 if (mark.is_self_forwarded()) {
319 return cast_to_oop(this);
320 } else {
321 return mark.forwardee();
322 }
323 }
324
325 // Note that the forwardee is not the same thing as the displaced_mark.
350 if (m.has_displaced_mark_helper()) {
351 m.set_displaced_mark_helper(m.displaced_mark_helper().incr_age());
352 } else {
353 set_mark(m.incr_age());
354 }
355 }
356
357 template <typename OopClosureType>
358 void oopDesc::oop_iterate(OopClosureType* cl) {
359 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass());
360 }
361
362 template <typename OopClosureType>
363 void oopDesc::oop_iterate(OopClosureType* cl, MemRegion mr) {
364 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass(), mr);
365 }
366
367 template <typename OopClosureType>
368 size_t oopDesc::oop_iterate_size(OopClosureType* cl) {
369 Klass* k = klass();
370 size_t size = size_given_klass(k);
371 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k);
372 return size;
373 }
374
375 template <typename OopClosureType>
376 size_t oopDesc::oop_iterate_size(OopClosureType* cl, MemRegion mr) {
377 Klass* k = klass();
378 size_t size = size_given_klass(k);
379 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k, mr);
380 return size;
381 }
382
383 template <typename OopClosureType>
384 void oopDesc::oop_iterate_backwards(OopClosureType* cl) {
385 oop_iterate_backwards(cl, klass());
386 }
387
388 template <typename OopClosureType>
389 void oopDesc::oop_iterate_backwards(OopClosureType* cl, Klass* k) {
390 // In this assert, we cannot safely access the Klass* with compact headers.
391 assert(k == klass(), "wrong klass");
392 OopIteratorClosureDispatch::oop_oop_iterate_backwards(cl, this, k);
393 }
394
395 bool oopDesc::is_instanceof_or_null(oop obj, Klass* klass) {
396 return obj == nullptr || obj->klass()->is_subtype_of(klass);
397 }
398
399 intptr_t oopDesc::identity_hash() {
400 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
401 // Note: The mark must be read into local variable to avoid concurrent updates.
402 markWord mrk = mark();
403 if (mrk.is_unlocked() && !mrk.has_no_hash()) {
404 return mrk.hash();
405 } else if (mrk.is_marked()) {
406 return mrk.hash();
407 } else {
408 return slow_identity_hash();
409 }
410 }
411
412 // This checks fast simple case of whether the oop has_no_hash,
413 // to optimize JVMTI table lookup.
414 bool oopDesc::fast_no_hash_check() {
415 markWord mrk = mark_acquire();
416 assert(!mrk.is_marked(), "should never be marked");
417 return mrk.is_unlocked() && mrk.has_no_hash();
418 }
419
420 bool oopDesc::has_displaced_mark() const {
421 return mark().has_displaced_mark_helper();
422 }
423
424 markWord oopDesc::displaced_mark() const {
425 return mark().displaced_mark_helper();
426 }
427
428 void oopDesc::set_displaced_mark(markWord m) {
429 mark().set_displaced_mark_helper(m);
430 }
431
432 bool oopDesc::mark_must_be_preserved() const {
433 return mark_must_be_preserved(mark());
434 }
435
436 bool oopDesc::mark_must_be_preserved(markWord m) const {
437 return m.must_be_preserved();
438 }
439
440 #endif // SHARE_OOPS_OOP_INLINE_HPP
|
42 #include "utilities/align.hpp"
43 #include "utilities/debug.hpp"
44 #include "utilities/globalDefinitions.hpp"
45 #include "utilities/macros.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 void* oopDesc::base_addr() { return this; }
51 const void* oopDesc::base_addr() const { return this; }
52
53 markWord oopDesc::mark() const {
54 return AtomicAccess::load(&_mark);
55 }
56
57 markWord oopDesc::mark_acquire() const {
58 return AtomicAccess::load_acquire(&_mark);
59 }
60
61 void oopDesc::set_mark(markWord m) {
62 if (UseCompactObjectHeaders) {
63 AtomicAccess::store(reinterpret_cast<uint32_t volatile*>(&_mark), m.value32());
64 } else {
65 AtomicAccess::store(&_mark, m);
66 }
67 }
68
69 void oopDesc::set_mark_full(markWord m) {
70 AtomicAccess::store(&_mark, m);
71 }
72
73 void oopDesc::set_mark(HeapWord* mem, markWord m) {
74 if (UseCompactObjectHeaders) {
75 *(uint32_t*)(((char*)mem) + mark_offset_in_bytes()) = m.value32();
76 } else {
77 *(markWord*)(((char*)mem) + mark_offset_in_bytes()) = m;
78 }
79 }
80
81 void oopDesc::release_set_mark(HeapWord* mem, markWord m) {
82 if (UseCompactObjectHeaders) {
83 AtomicAccess::release_store((uint32_t*)(((char*)mem) + mark_offset_in_bytes()), m.value32());
84 } else {
85 AtomicAccess::release_store((markWord*)(((char*)mem) + mark_offset_in_bytes()), m);
86 }
87 }
88
89 void oopDesc::release_set_mark(markWord m) {
90 if (UseCompactObjectHeaders) {
91 AtomicAccess::release_store(reinterpret_cast<uint32_t volatile*>(&_mark), m.value32());
92 } else {
93 AtomicAccess::release_store(&_mark, m);
94 }
95 }
96
97 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark) {
98 return AtomicAccess::cmpxchg(&_mark, old_mark, new_mark);
99 }
100
101 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark, atomic_memory_order order) {
102 return AtomicAccess::cmpxchg(&_mark, old_mark, new_mark, order);
103 }
104
105 markWord oopDesc::prototype_mark() const {
106 if (UseCompactObjectHeaders) {
107 return klass()->prototype_header();
108 } else {
109 return markWord::prototype();
110 }
111 }
112
113 void oopDesc::init_mark() {
114 set_mark(prototype_mark());
115 }
116
117 void oopDesc::reinit_mark() {
118 if (UseCompactObjectHeaders) {
119 markWord m = prototype_mark().copy_hashctrl_from(mark());
120 assert(m.is_neutral(), "must be neutral");
121 set_mark(m);
122 } else {
123 set_mark(prototype_mark());
124 }
125 }
126
127 Klass* oopDesc::klass() const {
128 return CompressedKlassPointers::decode_not_null(narrow_klass());
129 }
130
131 Klass* oopDesc::klass_or_null() const {
132 return CompressedKlassPointers::decode(narrow_klass());
133 }
134
135 Klass* oopDesc::klass_or_null_acquire() const {
136 return CompressedKlassPointers::decode(narrow_klass_acquire());
137 }
138
139 Klass* oopDesc::klass_without_asserts() const {
140 return CompressedKlassPointers::decode_without_asserts(narrow_klass());
141 }
142
143 narrowKlass oopDesc::narrow_klass() const {
144 switch (ObjLayout::klass_mode()) {
145 case ObjLayout::Compact:
146 return mark().narrow_klass();
167 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
168 _compressed_klass = CompressedKlassPointers::encode_not_null(k);
169 }
170
171 void oopDesc::release_set_klass(HeapWord* mem, Klass* k) {
172 assert(Universe::is_bootstrapping() || (k != nullptr && k->is_klass()), "incorrect Klass");
173 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
174 char* raw_mem = ((char*)mem + klass_offset_in_bytes());
175 AtomicAccess::release_store((narrowKlass*)raw_mem, CompressedKlassPointers::encode_not_null(k));
176 }
177
178 void oopDesc::set_klass_gap(HeapWord* mem, int v) {
179 assert(has_klass_gap(), "precondition");
180 *(int*)(((char*)mem) + klass_gap_offset_in_bytes()) = v;
181 }
182
183 bool oopDesc::is_a(Klass* k) const {
184 return klass()->is_subtype_of(k);
185 }
186
187 size_t oopDesc::size_given_mark_and_klass(markWord mrk, const Klass* kls) {
188 size_t sz = base_size_given_klass(mrk, kls);
189 if (UseCompactObjectHeaders) {
190 assert(!mrk.has_displaced_mark_helper(), "must not be displaced");
191 if (mrk.is_expanded() && kls->expand_for_hash(cast_to_oop(this), mrk)) {
192 sz = align_object_size(sz + 1);
193 }
194 }
195 return sz;
196 }
197
198 size_t oopDesc::size_forwarded() {
199 assert(is_forwarded(), "must be forwarded");
200 markWord m = mark();
201 oop fwd = forwardee(m);
202 if (!UseCompactObjectHeaders) {
203 return fwd->size();
204 }
205 markWord fm = fwd->mark();
206 Klass* klass = fm.klass();
207 if (m.is_forward_expanded()) {
208 // Forwardee was expanded during copy but the original was not.
209 // Original must have base size.
210 return fwd->base_size_given_klass(fm, klass);
211 }
212 // Original and copy have same size (whether expanded or not).
213 return fwd->size_given_mark_and_klass(fm, klass);
214 }
215
216 size_t oopDesc::copy_size(size_t size, markWord mark) const {
217 if (UseCompactObjectHeaders) {
218 assert(!mark.has_displaced_mark_helper(), "must not be displaced");
219 Klass* klass = mark.klass();
220 if (mark.is_hashed_not_expanded() && klass->expand_for_hash(cast_to_oop(this), mark)) {
221 size = align_object_size(size + 1);
222 }
223 }
224 assert(is_object_aligned(size), "Oop size is not properly aligned: %zu", size);
225 return size;
226 }
227
228 size_t oopDesc::copy_size_cds(size_t size, markWord mark) const {
229 if (UseCompactObjectHeaders) {
230 assert(!mark.has_displaced_mark_helper(), "must not be displaced");
231 Klass* klass = mark.klass();
232 if (mark.is_not_hashed_expanded()) {
233 assert(klass->expand_for_hash(cast_to_oop(this), mark), "must be?");
234 }
235 if (mark.is_hashed_not_expanded() && klass->expand_for_hash(cast_to_oop(this), mark)) {
236 size = align_object_size(size + 1);
237 }
238 if (mark.is_not_hashed_expanded() && klass->expand_for_hash(cast_to_oop(this), mark)) {
239 size = align_object_size(size - ObjectAlignmentInBytes / HeapWordSize);
240 }
241 }
242 assert(is_object_aligned(size), "Oop size is not properly aligned: %zu", size);
243 return size;
244 }
245
246 size_t oopDesc::size() {
247 return size_given_mark_and_klass(mark(), klass());
248 }
249
250 size_t oopDesc::base_size_given_klass(markWord mrk, const Klass* klass) {
251 int lh = klass->layout_helper();
252 size_t s;
253
254 // lh is now a value computed at class initialization that may hint
255 // at the size. For instances, this is positive and equal to the
256 // size. For arrays, this is negative and provides log2 of the
257 // array element size. For other oops, it is zero and thus requires
258 // a virtual call.
259 //
260 // We go to all this trouble because the size computation is at the
261 // heart of phase 2 of mark-compaction, and called for every object,
262 // alive or dead. So the speed here is equal in importance to the
263 // speed of allocation.
264
265 if (lh > Klass::_lh_neutral_value) {
266 if (!Klass::layout_helper_needs_slow_path(lh)) {
267 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
268 } else {
269 s = klass->oop_size(this, mrk);
270 }
271 } else if (lh <= Klass::_lh_neutral_value) {
272 // The most common case is instances; fall through if so.
273 if (lh < Klass::_lh_neutral_value) {
274 // Second most common case is arrays. We have to fetch the
275 // length of the array, shift (multiply) it appropriately,
276 // up to wordSize, add the header, and align to object size.
277 size_t size_in_bytes;
278 size_t array_length;
279 #ifdef _LP64
280 if (UseCompactObjectHeaders) {
281 array_length = (size_t) mrk.array_length();
282 } else
283 #endif
284 array_length = (size_t)((arrayOop)this)->length();
285
286 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
287 size_in_bytes += Klass::layout_helper_header_size(lh);
288
289 // This code could be simplified, but by keeping array_header_in_bytes
290 // in units of bytes and doing it this way we can round up just once,
291 // skipping the intermediate round to HeapWordSize.
292 s = align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize;
293 if (s != klass->oop_size(this, mrk)) {
294 tty->print_cr("length: %zu", array_length);
295 tty->print_cr("log element size: %d", Klass::layout_helper_log2_element_size(lh));
296 tty->print_cr("is_objArray: %s", BOOL_TO_STR(klass->is_objArray_klass()));
297 }
298 assert(s == klass->oop_size(this, mrk), "wrong array object size, s: %zu, oop_size: %zu", s, klass->oop_size(this, mrk));
299 } else {
300 // Must be zero, so bite the bullet and take the virtual call.
301 s = klass->oop_size(this, mrk);
302 }
303 }
304
305 assert(s > 0, "Oop size must be greater than zero, not %zu", s);
306 assert(is_object_aligned(s), "Oop size is not properly aligned: %zu", s);
307 return s;
308 }
309
310 bool oopDesc::is_instance() const { return klass()->is_instance_klass(); }
311 bool oopDesc::is_instanceRef() const { return klass()->is_reference_instance_klass(); }
312 bool oopDesc::is_stackChunk() const { return klass()->is_stack_chunk_instance_klass(); }
313 bool oopDesc::is_array() const { return klass()->is_array_klass(); }
314 bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); }
315 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); }
316
317 template<typename T>
318 T* oopDesc::field_addr(int offset) const { return reinterpret_cast<T*>(cast_from_oop<intptr_t>(as_oop()) + offset); }
319
320 template <typename T>
321 size_t oopDesc::field_offset(T* p) const { return pointer_delta((void*)p, (void*)this, 1); }
364 }
365
366 bool oopDesc::is_gc_marked() const {
367 return mark().is_marked();
368 }
369
370 // Used by scavengers
371 bool oopDesc::is_forwarded() const {
372 return mark().is_forwarded();
373 }
374
375 bool oopDesc::is_self_forwarded() const {
376 return mark().is_self_forwarded();
377 }
378
379 // Used by scavengers
380 void oopDesc::forward_to(oop p) {
381 assert(cast_from_oop<oopDesc*>(p) != this,
382 "must not be used for self-forwarding, use forward_to_self() instead");
383 markWord m = markWord::encode_pointer_as_mark(p);
384 if (UseCompactObjectHeaders && p->mark().is_expanded() && !mark().is_expanded()) {
385 m = m.set_forward_expanded();
386 }
387 assert(m.decode_pointer() == p, "encoding must be reversible");
388 set_mark_full(m);
389 }
390
391 void oopDesc::forward_to_self() {
392 set_mark(mark().set_self_forwarded());
393 }
394
395 void oopDesc::reset_forwarded() {
396 markWord m = mark();
397 if (m.is_self_forwarded()) {
398 unset_self_forwarded();
399 } else if (m.is_forwarded()) {
400 // Restore Klass* and hash-bits in the header,
401 // for correct iteration.
402 markWord fwd_mark = forwardee()->mark();
403 if (m.is_forward_expanded()) {
404 // Un-expand original object.
405 fwd_mark = fwd_mark.set_hashed_not_expanded();
406 }
407 set_mark_full(fwd_mark);
408 }
409 }
410
411 oop oopDesc::cas_set_forwardee(markWord new_mark, markWord compare, atomic_memory_order order) {
412 markWord old_mark = cas_set_mark(new_mark, compare, order);
413 if (old_mark == compare) {
414 return nullptr;
415 } else {
416 assert(old_mark.is_forwarded(), "must be forwarded here");
417 return forwardee(old_mark);
418 }
419 }
420
421 oop oopDesc::forward_to_atomic(oop p, markWord compare, atomic_memory_order order) {
422 assert(cast_from_oop<oopDesc*>(p) != this,
423 "must not be used for self-forwarding, use forward_to_self_atomic() instead");
424 markWord m = markWord::encode_pointer_as_mark(p);
425 if (UseCompactObjectHeaders && compare.is_hashed_not_expanded()) {
426 m = m.set_forward_expanded();
427 }
428 assert(forwardee(m) == p, "encoding must be reversible");
429 return cas_set_forwardee(m, compare, order);
430 }
431
432 oop oopDesc::forward_to_self_atomic(markWord old_mark, atomic_memory_order order) {
433 markWord new_mark = old_mark.set_self_forwarded();
434 assert(forwardee(new_mark) == cast_to_oop(this), "encoding must be reversible");
435 return cas_set_forwardee(new_mark, old_mark, order);
436 }
437
438 oop oopDesc::forwardee(markWord mark) const {
439 assert(mark.is_forwarded(), "only decode when actually forwarded");
440 if (mark.is_self_forwarded()) {
441 return cast_to_oop(this);
442 } else {
443 return mark.forwardee();
444 }
445 }
446
447 // Note that the forwardee is not the same thing as the displaced_mark.
472 if (m.has_displaced_mark_helper()) {
473 m.set_displaced_mark_helper(m.displaced_mark_helper().incr_age());
474 } else {
475 set_mark(m.incr_age());
476 }
477 }
478
479 template <typename OopClosureType>
480 void oopDesc::oop_iterate(OopClosureType* cl) {
481 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass());
482 }
483
484 template <typename OopClosureType>
485 void oopDesc::oop_iterate(OopClosureType* cl, MemRegion mr) {
486 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass(), mr);
487 }
488
489 template <typename OopClosureType>
490 size_t oopDesc::oop_iterate_size(OopClosureType* cl) {
491 Klass* k = klass();
492 size_t size = size_given_mark_and_klass(mark(), k);
493 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k);
494 return size;
495 }
496
497 template <typename OopClosureType>
498 size_t oopDesc::oop_iterate_size(OopClosureType* cl, MemRegion mr) {
499 Klass* k = klass();
500 size_t size = size_given_mark_and_klass(mark(), k);
501 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k, mr);
502 return size;
503 }
504
505 template <typename OopClosureType>
506 void oopDesc::oop_iterate_backwards(OopClosureType* cl) {
507 oop_iterate_backwards(cl, klass());
508 }
509
510 template <typename OopClosureType>
511 void oopDesc::oop_iterate_backwards(OopClosureType* cl, Klass* k) {
512 // In this assert, we cannot safely access the Klass* with compact headers.
513 assert(k == klass(), "wrong klass");
514 OopIteratorClosureDispatch::oop_oop_iterate_backwards(cl, this, k);
515 }
516
517 bool oopDesc::is_instanceof_or_null(oop obj, Klass* klass) {
518 return obj == nullptr || obj->klass()->is_subtype_of(klass);
519 }
520
521 intptr_t oopDesc::identity_hash() {
522 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
523 // Note: The mark must be read into local variable to avoid concurrent updates.
524 if (UseCompactObjectHeaders) {
525 markWord mrk = mark();
526 if (mrk.is_hashed_expanded()) {
527 Klass* klass = mrk.klass();
528 return int_field(klass->hash_offset_in_bytes(cast_to_oop(this), mrk));
529 }
530 // Fall-through to slow-case.
531 } else {
532 markWord mrk = mark();
533 if (mrk.is_unlocked() && !mrk.has_no_hash()) {
534 return mrk.hash();
535 } else if (mrk.is_marked()) {
536 return mrk.hash();
537 }
538 // Fall-through to slow-case.
539 }
540 return slow_identity_hash();
541 }
542
543 // This checks fast simple case of whether the oop has_no_hash,
544 // to optimize JVMTI table lookup.
545 bool oopDesc::fast_no_hash_check() {
546 markWord mrk = mark_acquire();
547 assert(!mrk.is_marked(), "should never be marked");
548 return (UseCompactObjectHeaders || mrk.is_unlocked()) && mrk.has_no_hash();
549 }
550
551 bool oopDesc::has_displaced_mark() const {
552 return mark().has_displaced_mark_helper();
553 }
554
555 markWord oopDesc::displaced_mark() const {
556 return mark().displaced_mark_helper();
557 }
558
559 void oopDesc::set_displaced_mark(markWord m) {
560 mark().set_displaced_mark_helper(m);
561 }
562
563 bool oopDesc::mark_must_be_preserved() const {
564 return mark_must_be_preserved(mark());
565 }
566
567 bool oopDesc::mark_must_be_preserved(markWord m) const {
568 return m.must_be_preserved();
569 }
570
571 inline void oopDesc::initialize_hash_if_necessary(oop obj) {
572 if (!UseCompactObjectHeaders) {
573 return;
574 }
575 markWord m = mark();
576 assert(!m.has_displaced_mark_helper(), "must not be displaced header");
577 if (m.is_hashed_not_expanded()) {
578 set_mark(initialize_hash_if_necessary(obj, m.klass(), m));
579 }
580 }
581
582
583 #endif // SHARE_OOPS_OOP_INLINE_HPP
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