1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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24
25 #ifndef SHARE_OOPS_OOP_INLINE_HPP
26 #define SHARE_OOPS_OOP_INLINE_HPP
27
28 #include "oops/oop.hpp"
29
30 #include "memory/iterator.inline.hpp"
31 #include "memory/universe.hpp"
32 #include "oops/access.inline.hpp"
33 #include "oops/arrayKlass.hpp"
34 #include "oops/arrayOop.hpp"
35 #include "oops/compressedKlass.inline.hpp"
36 #include "oops/flatArrayKlass.hpp"
37 #include "oops/instanceKlass.hpp"
38 #include "oops/markWord.inline.hpp"
39 #include "oops/objLayout.inline.hpp"
40 #include "oops/oopsHierarchy.hpp"
41 #include "runtime/arguments.hpp"
42 #include "runtime/atomicAccess.hpp"
43 #include "runtime/globals.hpp"
44 #include "utilities/align.hpp"
45 #include "utilities/debug.hpp"
46 #include "utilities/globalDefinitions.hpp"
47 #include "utilities/macros.hpp"
48
49 // Implementation of all inlined member functions defined in oop.hpp
50 // We need a separate file to avoid circular references
51
52 void* oopDesc::base_addr() { return this; }
53 const void* oopDesc::base_addr() const { return this; }
54
55 markWord oopDesc::mark() const {
56 return AtomicAccess::load(&_mark);
57 }
58
59 markWord oopDesc::mark_acquire() const {
60 return AtomicAccess::load_acquire(&_mark);
61 }
62
63 void oopDesc::set_mark(markWord m) {
64 AtomicAccess::store(&_mark, m);
65 }
66
67 void oopDesc::set_mark(HeapWord* mem, markWord m) {
68 *(markWord*)(((char*)mem) + mark_offset_in_bytes()) = m;
69 }
70
71 void oopDesc::release_set_mark(HeapWord* mem, markWord m) {
72 AtomicAccess::release_store((markWord*)(((char*)mem) + mark_offset_in_bytes()), m);
73 }
74
75 void oopDesc::release_set_mark(markWord m) {
76 AtomicAccess::release_store(&_mark, m);
77 }
78
79 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark) {
80 return AtomicAccess::cmpxchg(&_mark, old_mark, new_mark);
81 }
82
83 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark, atomic_memory_order order) {
84 return AtomicAccess::cmpxchg(&_mark, old_mark, new_mark, order);
85 }
86
87 markWord oopDesc::prototype_mark() const {
88 if (UseCompactObjectHeaders || Arguments::is_valhalla_enabled()) {
89 return klass()->prototype_header();
90 } else {
91 return markWord::prototype();
92 }
93 }
94
95 void oopDesc::init_mark() {
96 set_mark(prototype_mark());
97 }
98
99 Klass* oopDesc::klass() const {
100 switch (ObjLayout::klass_mode()) {
101 case ObjLayout::Compact:
102 return mark().klass();
103 case ObjLayout::Compressed:
104 return CompressedKlassPointers::decode_not_null(_compressed_klass);
105 default:
106 ShouldNotReachHere();
107 }
108 }
109
110 Klass* oopDesc::klass_or_null() const {
111 switch (ObjLayout::klass_mode()) {
112 case ObjLayout::Compact:
113 return mark().klass_or_null();
114 case ObjLayout::Compressed:
115 return CompressedKlassPointers::decode(_compressed_klass);
116 default:
117 ShouldNotReachHere();
118 }
119 }
120
121 Klass* oopDesc::klass_or_null_acquire() const {
122 switch (ObjLayout::klass_mode()) {
123 case ObjLayout::Compact:
124 return mark_acquire().klass();
125 case ObjLayout::Compressed: {
126 narrowKlass narrow_klass = AtomicAccess::load_acquire(&_compressed_klass);
127 return CompressedKlassPointers::decode(narrow_klass);
128 }
129 default:
130 ShouldNotReachHere();
131 }
132 }
133
134 Klass* oopDesc::klass_without_asserts() const {
135 switch (ObjLayout::klass_mode()) {
136 case ObjLayout::Compact:
137 return mark().klass_without_asserts();
138 case ObjLayout::Compressed:
139 return CompressedKlassPointers::decode_without_asserts(_compressed_klass);
140 default:
141 ShouldNotReachHere();
142 }
143 }
144
145 narrowKlass oopDesc::narrow_klass() const {
146 switch (ObjLayout::klass_mode()) {
147 case ObjLayout::Compact:
148 return mark().narrow_klass();
149 case ObjLayout::Compressed:
150 return _compressed_klass;
151 default:
152 ShouldNotReachHere();
153 }
154 }
155
156 void oopDesc::set_klass(Klass* k) {
157 assert(Universe::is_bootstrapping() || (k != nullptr && k->is_klass()), "incorrect Klass");
158 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
159 _compressed_klass = CompressedKlassPointers::encode_not_null(k);
160 }
161
162 void oopDesc::release_set_klass(HeapWord* mem, Klass* k) {
163 assert(Universe::is_bootstrapping() || (k != nullptr && k->is_klass()), "incorrect Klass");
164 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
165 char* raw_mem = ((char*)mem + klass_offset_in_bytes());
166 AtomicAccess::release_store((narrowKlass*)raw_mem, CompressedKlassPointers::encode_not_null(k));
167 }
168
169 void oopDesc::set_klass_gap(HeapWord* mem, int v) {
170 assert(has_klass_gap(), "precondition");
171 *(int*)(((char*)mem) + klass_gap_offset_in_bytes()) = v;
172 }
173
174 bool oopDesc::is_a(Klass* k) const {
175 return klass()->is_subtype_of(k);
176 }
177
178 size_t oopDesc::size() {
179 return size_given_klass(klass());
180 }
181
182 size_t oopDesc::size_given_klass(Klass* klass) {
183 int lh = klass->layout_helper();
184 size_t s;
185
186 // lh is now a value computed at class initialization that may hint
187 // at the size. For instances, this is positive and equal to the
188 // size. For arrays, this is negative and provides log2 of the
189 // array element size. For other oops, it is zero and thus requires
190 // a virtual call.
191 //
192 // We go to all this trouble because the size computation is at the
193 // heart of phase 2 of mark-compaction, and called for every object,
194 // alive or dead. So the speed here is equal in importance to the
195 // speed of allocation.
196
197 if (lh > Klass::_lh_neutral_value) {
198 if (!Klass::layout_helper_needs_slow_path(lh)) {
199 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
200 } else {
201 s = klass->oop_size(this);
202 }
203 } else if (lh <= Klass::_lh_neutral_value) {
204 // The most common case is instances; fall through if so.
205 if (lh < Klass::_lh_neutral_value) {
206 // Second most common case is arrays. We have to fetch the
207 // length of the array, shift (multiply) it appropriately,
208 // up to wordSize, add the header, and align to object size.
209 size_t size_in_bytes;
210 size_t array_length = (size_t) ((arrayOop)this)->length();
211 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
212 size_in_bytes += Klass::layout_helper_header_size(lh);
213
214 // This code could be simplified, but by keeping array_header_in_bytes
215 // in units of bytes and doing it this way we can round up just once,
216 // skipping the intermediate round to HeapWordSize.
217 s = align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize;
218
219 assert(s == klass->oop_size(this), "wrong array object size");
220 } else {
221 // Must be zero, so bite the bullet and take the virtual call.
222 s = klass->oop_size(this);
223 }
224 }
225
226 assert(s > 0, "Oop size must be greater than zero, not %zu", s);
227 assert(is_object_aligned(s), "Oop size is not properly aligned: %zu", s);
228 return s;
229 }
230
231 bool oopDesc::is_instance() const { return klass()->is_instance_klass(); }
232 bool oopDesc::is_inline() const { return klass()->is_inline_klass(); }
233 bool oopDesc::is_instanceRef() const { return klass()->is_reference_instance_klass(); }
234 bool oopDesc::is_stackChunk() const { return klass()->is_stack_chunk_instance_klass(); }
235 bool oopDesc::is_array() const { return klass()->is_array_klass(); }
236 bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); }
237 bool oopDesc::is_refArray() const { return klass()->is_refArray_klass(); }
238 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); }
239 bool oopDesc::is_refined_objArray() const { return klass()->is_refined_objArray_klass(); }
240 bool oopDesc::is_flatArray() const { return klass()->is_flatArray_klass(); }
241
242 bool oopDesc::is_array_with_oops() const {
243 if (!is_objArray()) {
244 return false;
245 }
246
247 assert(is_refined_objArray(), "Must be");
248 return is_refArray() || FlatArrayKlass::cast(klass())->contains_oops();
249 }
250
251 bool oopDesc::is_inline_type() const { return mark().is_inline_type(); }
252
253 template<typename T>
254 T* oopDesc::field_addr(int offset) const { return reinterpret_cast<T*>(cast_from_oop<intptr_t>(as_oop()) + offset); }
255
256 template <typename T>
257 size_t oopDesc::field_offset(T* p) const { return pointer_delta((void*)p, (void*)this, 1); }
258
259 template <DecoratorSet decorators>
260 inline oop oopDesc::obj_field_access(int offset) const { return HeapAccess<decorators>::oop_load_at(as_oop(), offset); }
261 inline oop oopDesc::obj_field(int offset) const { return HeapAccess<>::oop_load_at(as_oop(), offset); }
262
263 inline void oopDesc::obj_field_put(int offset, oop value) { HeapAccess<>::oop_store_at(as_oop(), offset, value); }
264 template <DecoratorSet decorators>
265 inline void oopDesc::obj_field_put_access(int offset, oop value) { HeapAccess<decorators>::oop_store_at(as_oop(), offset, value); }
266
267 inline jbyte oopDesc::byte_field(int offset) const { return *field_addr<jbyte>(offset); }
268 inline void oopDesc::byte_field_put(int offset, jbyte value) { *field_addr<jbyte>(offset) = value; }
269
270 inline jchar oopDesc::char_field(int offset) const { return *field_addr<jchar>(offset); }
271 inline void oopDesc::char_field_put(int offset, jchar value) { *field_addr<jchar>(offset) = value; }
272
273 inline jboolean oopDesc::bool_field(int offset) const { return *field_addr<jboolean>(offset); }
274 inline void oopDesc::bool_field_put(int offset, jboolean value) { *field_addr<jboolean>(offset) = jboolean(value & 1); }
275 inline jboolean oopDesc::bool_field_volatile(int offset) const { return RawAccess<MO_SEQ_CST>::load(field_addr<jboolean>(offset)); }
276 inline void oopDesc::bool_field_put_volatile(int offset, jboolean value) { RawAccess<MO_SEQ_CST>::store(field_addr<jboolean>(offset), jboolean(value & 1)); }
277 inline jshort oopDesc::short_field(int offset) const { return *field_addr<jshort>(offset); }
278 inline void oopDesc::short_field_put(int offset, jshort value) { *field_addr<jshort>(offset) = value; }
279
280 inline jint oopDesc::int_field(int offset) const { return *field_addr<jint>(offset); }
281 inline void oopDesc::int_field_put(int offset, jint value) { *field_addr<jint>(offset) = value; }
282 inline jint oopDesc::int_field_relaxed(int offset) const { return AtomicAccess::load(field_addr<jint>(offset)); }
283 inline void oopDesc::int_field_put_relaxed(int offset, jint value) { AtomicAccess::store(field_addr<jint>(offset), value); }
284
285 inline jlong oopDesc::long_field(int offset) const { return *field_addr<jlong>(offset); }
286 inline void oopDesc::long_field_put(int offset, jlong value) { *field_addr<jlong>(offset) = value; }
287
288 inline jfloat oopDesc::float_field(int offset) const { return *field_addr<jfloat>(offset); }
289 inline void oopDesc::float_field_put(int offset, jfloat value) { *field_addr<jfloat>(offset) = value; }
290
291 inline jdouble oopDesc::double_field(int offset) const { return *field_addr<jdouble>(offset); }
292 inline void oopDesc::double_field_put(int offset, jdouble value) { *field_addr<jdouble>(offset) = value; }
293
294 bool oopDesc::is_locked() const {
295 return mark().is_locked();
296 }
297
298 bool oopDesc::is_unlocked() const {
299 return mark().is_unlocked();
300 }
301
302 bool oopDesc::is_gc_marked() const {
303 return mark().is_marked();
304 }
305
306 // Used by scavengers
307 bool oopDesc::is_forwarded() const {
308 return mark().is_forwarded();
309 }
310
311 bool oopDesc::is_self_forwarded() const {
312 return mark().is_self_forwarded();
313 }
314
315 // Used by scavengers
316 void oopDesc::forward_to(oop p) {
317 assert(cast_from_oop<oopDesc*>(p) != this,
318 "must not be used for self-forwarding, use forward_to_self() instead");
319 markWord m = markWord::encode_pointer_as_mark(p);
320 assert(m.decode_pointer() == p, "encoding must be reversible");
321 set_mark(m);
322 }
323
324 void oopDesc::forward_to_self() {
325 set_mark(mark().set_self_forwarded());
326 }
327
328 oop oopDesc::cas_set_forwardee(markWord new_mark, markWord compare, atomic_memory_order order) {
329 markWord old_mark = cas_set_mark(new_mark, compare, order);
330 if (old_mark == compare) {
331 return nullptr;
332 } else {
333 assert(old_mark.is_forwarded(), "must be forwarded here");
334 return forwardee(old_mark);
335 }
336 }
337
338 oop oopDesc::forward_to_atomic(oop p, markWord compare, atomic_memory_order order) {
339 assert(cast_from_oop<oopDesc*>(p) != this,
340 "must not be used for self-forwarding, use forward_to_self_atomic() instead");
341 markWord m = markWord::encode_pointer_as_mark(p);
342 assert(forwardee(m) == p, "encoding must be reversible");
343 return cas_set_forwardee(m, compare, order);
344 }
345
346 oop oopDesc::forward_to_self_atomic(markWord old_mark, atomic_memory_order order) {
347 markWord new_mark = old_mark.set_self_forwarded();
348 assert(forwardee(new_mark) == cast_to_oop(this), "encoding must be reversible");
349 return cas_set_forwardee(new_mark, old_mark, order);
350 }
351
352 oop oopDesc::forwardee(markWord mark) const {
353 assert(mark.is_forwarded(), "only decode when actually forwarded");
354 if (mark.is_self_forwarded()) {
355 return cast_to_oop(this);
356 } else {
357 return mark.forwardee();
358 }
359 }
360
361 // Note that the forwardee is not the same thing as the displaced_mark.
362 // The forwardee is used when copying during scavenge and mark-sweep.
363 // It does need to clear the low two locking- and GC-related bits.
364 oop oopDesc::forwardee() const {
365 return forwardee(mark());
366 }
367
368 void oopDesc::unset_self_forwarded() {
369 set_mark(mark().unset_self_forwarded());
370 }
371
372 // The following method needs to be MT safe.
373 uint oopDesc::age() const {
374 markWord m = mark();
375 assert(!m.is_marked(), "Attempt to read age from forwarded mark");
376 if (m.has_displaced_mark_helper()) {
377 return m.displaced_mark_helper().age();
378 } else {
379 return m.age();
380 }
381 }
382
383 void oopDesc::incr_age() {
384 markWord m = mark();
385 assert(!m.is_marked(), "Attempt to increment age of forwarded mark");
386 if (m.has_displaced_mark_helper()) {
387 m.set_displaced_mark_helper(m.displaced_mark_helper().incr_age());
388 } else {
389 set_mark(m.incr_age());
390 }
391 }
392
393 template <typename OopClosureType>
394 void oopDesc::oop_iterate(OopClosureType* cl) {
395 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass());
396 }
397
398 template <typename OopClosureType>
399 void oopDesc::oop_iterate(OopClosureType* cl, MemRegion mr) {
400 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass(), mr);
401 }
402
403 template <typename OopClosureType>
404 size_t oopDesc::oop_iterate_size(OopClosureType* cl) {
405 Klass* k = klass();
406 size_t size = size_given_klass(k);
407 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k);
408 return size;
409 }
410
411 template <typename OopClosureType>
412 size_t oopDesc::oop_iterate_size(OopClosureType* cl, MemRegion mr) {
413 Klass* k = klass();
414 size_t size = size_given_klass(k);
415 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k, mr);
416 return size;
417 }
418
419 template <typename OopClosureType>
420 void oopDesc::oop_iterate_backwards(OopClosureType* cl) {
421 oop_iterate_backwards(cl, klass());
422 }
423
424 template <typename OopClosureType>
425 void oopDesc::oop_iterate_backwards(OopClosureType* cl, Klass* k) {
426 // In this assert, we cannot safely access the Klass* with compact headers.
427 assert(k == klass(), "wrong klass");
428 OopIteratorClosureDispatch::oop_oop_iterate_backwards(cl, this, k);
429 }
430
431 bool oopDesc::is_instanceof_or_null(oop obj, Klass* klass) {
432 return obj == nullptr || obj->klass()->is_subtype_of(klass);
433 }
434
435 intptr_t oopDesc::identity_hash() {
436 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
437 // Note: The mark must be read into local variable to avoid concurrent updates.
438 markWord mrk = mark();
439 if (mrk.is_unlocked() && !mrk.has_no_hash()) {
440 return mrk.hash();
441 } else if (mrk.is_marked()) {
442 return mrk.hash();
443 } else {
444 return slow_identity_hash();
445 }
446 }
447
448 // This checks fast simple case of whether the oop has_no_hash,
449 // to optimize JVMTI table lookup.
450 bool oopDesc::fast_no_hash_check() {
451 markWord mrk = mark_acquire();
452 assert(!mrk.is_marked(), "should never be marked");
453 return mrk.is_unlocked() && mrk.has_no_hash();
454 }
455
456 bool oopDesc::has_displaced_mark() const {
457 return mark().has_displaced_mark_helper();
458 }
459
460 markWord oopDesc::displaced_mark() const {
461 return mark().displaced_mark_helper();
462 }
463
464 void oopDesc::set_displaced_mark(markWord m) {
465 mark().set_displaced_mark_helper(m);
466 }
467
468 bool oopDesc::mark_must_be_preserved() const {
469 return mark_must_be_preserved(mark());
470 }
471
472 bool oopDesc::mark_must_be_preserved(markWord m) const {
473 return m.must_be_preserved();
474 }
475
476 #endif // SHARE_OOPS_OOP_INLINE_HPP