1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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/instanceKlass.hpp"
37 #include "oops/markWord.inline.hpp"
38 #include "oops/objLayout.inline.hpp"
39 #include "oops/oopsHierarchy.hpp"
40 #include "runtime/atomicAccess.hpp"
41 #include "runtime/globals.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 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 || EnableValhalla) {
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 // This is for parallel gc, which doesn't always have the klass.
98 // markWord::must_be_preserved preserves the original prototype header bits for EnableValhalla,
99 // I don't know why serial gc doesn't work the same.
100 void oopDesc::reinit_mark() {
101 if (UseCompactObjectHeaders) {
102 set_mark(klass()->prototype_header());
103 } else {
104 set_mark(markWord::prototype());
105 }
106 }
107
108 Klass* oopDesc::klass() const {
109 switch (ObjLayout::klass_mode()) {
110 case ObjLayout::Compact:
111 return mark().klass();
112 case ObjLayout::Compressed:
113 return CompressedKlassPointers::decode_not_null(_metadata._compressed_klass);
114 default:
115 return _metadata._klass;
116 }
117 }
118
119 Klass* oopDesc::klass_or_null() const {
120 switch (ObjLayout::klass_mode()) {
121 case ObjLayout::Compact:
122 return mark().klass_or_null();
123 case ObjLayout::Compressed:
124 return CompressedKlassPointers::decode(_metadata._compressed_klass);
125 default:
126 return _metadata._klass;
127 }
128 }
129
130 Klass* oopDesc::klass_or_null_acquire() const {
131 switch (ObjLayout::klass_mode()) {
132 case ObjLayout::Compact:
133 return mark_acquire().klass();
134 case ObjLayout::Compressed: {
135 narrowKlass narrow_klass = AtomicAccess::load_acquire(&_metadata._compressed_klass);
136 return CompressedKlassPointers::decode(narrow_klass);
137 }
138 default:
139 return AtomicAccess::load_acquire(&_metadata._klass);
140 }
141 }
142
143 Klass* oopDesc::klass_without_asserts() const {
144 switch (ObjLayout::klass_mode()) {
145 case ObjLayout::Compact:
146 return mark().klass_without_asserts();
147 case ObjLayout::Compressed:
148 return CompressedKlassPointers::decode_without_asserts(_metadata._compressed_klass);
149 default:
150 return _metadata._klass;
151 }
152 }
153
154 narrowKlass oopDesc::narrow_klass() const {
155 switch (ObjLayout::klass_mode()) {
156 case ObjLayout::Compact:
157 return mark().narrow_klass();
158 case ObjLayout::Compressed:
159 return _metadata._compressed_klass;
160 default:
161 ShouldNotReachHere();
162 }
163 }
164
165 void oopDesc::set_klass(Klass* k) {
166 assert(Universe::is_bootstrapping() || (k != nullptr && k->is_klass()), "incorrect Klass");
167 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
168 if (UseCompressedClassPointers) {
169 _metadata._compressed_klass = CompressedKlassPointers::encode_not_null(k);
170 } else {
171 _metadata._klass = k;
172 }
173 }
174
175 void oopDesc::release_set_klass(HeapWord* mem, Klass* k) {
176 assert(Universe::is_bootstrapping() || (k != nullptr && k->is_klass()), "incorrect Klass");
177 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
178 char* raw_mem = ((char*)mem + klass_offset_in_bytes());
179 if (UseCompressedClassPointers) {
180 AtomicAccess::release_store((narrowKlass*)raw_mem,
181 CompressedKlassPointers::encode_not_null(k));
182 } else {
183 AtomicAccess::release_store((Klass**)raw_mem, k);
184 }
185 }
186
187 void oopDesc::set_klass_gap(HeapWord* mem, int v) {
188 assert(has_klass_gap(), "precondition");
189 *(int*)(((char*)mem) + klass_gap_offset_in_bytes()) = v;
190 }
191
192 bool oopDesc::is_a(Klass* k) const {
193 return klass()->is_subtype_of(k);
194 }
195
196 size_t oopDesc::size() {
197 return size_given_klass(klass());
198 }
199
200 size_t oopDesc::size_given_klass(Klass* klass) {
201 int lh = klass->layout_helper();
202 size_t s;
203
204 // lh is now a value computed at class initialization that may hint
205 // at the size. For instances, this is positive and equal to the
206 // size. For arrays, this is negative and provides log2 of the
207 // array element size. For other oops, it is zero and thus requires
208 // a virtual call.
209 //
210 // We go to all this trouble because the size computation is at the
211 // heart of phase 2 of mark-compaction, and called for every object,
212 // alive or dead. So the speed here is equal in importance to the
213 // speed of allocation.
214
215 if (lh > Klass::_lh_neutral_value) {
216 if (!Klass::layout_helper_needs_slow_path(lh)) {
217 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
218 } else {
219 s = klass->oop_size(this);
220 }
221 } else if (lh <= Klass::_lh_neutral_value) {
222 // The most common case is instances; fall through if so.
223 if (lh < Klass::_lh_neutral_value) {
224 // Second most common case is arrays. We have to fetch the
225 // length of the array, shift (multiply) it appropriately,
226 // up to wordSize, add the header, and align to object size.
227 size_t size_in_bytes;
228 size_t array_length = (size_t) ((arrayOop)this)->length();
229 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
230 size_in_bytes += Klass::layout_helper_header_size(lh);
231
232 // This code could be simplified, but by keeping array_header_in_bytes
233 // in units of bytes and doing it this way we can round up just once,
234 // skipping the intermediate round to HeapWordSize.
235 s = align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize;
236
237 assert(s == klass->oop_size(this), "wrong array object size");
238 } else {
239 // Must be zero, so bite the bullet and take the virtual call.
240 s = klass->oop_size(this);
241 }
242 }
243
244 assert(s > 0, "Oop size must be greater than zero, not %zu", s);
245 assert(is_object_aligned(s), "Oop size is not properly aligned: %zu", s);
246 return s;
247 }
248
249 bool oopDesc::is_instance() const { return klass()->is_instance_klass(); }
250 bool oopDesc::is_instanceRef() const { return klass()->is_reference_instance_klass(); }
251 bool oopDesc::is_stackChunk() const { return klass()->is_stack_chunk_instance_klass(); }
252 bool oopDesc::is_array() const { return klass()->is_array_klass(); }
253 bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); }
254 bool oopDesc::is_refArray() const { return klass()->is_refArray_klass(); }
255 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); }
256 bool oopDesc::is_refined_objArray() const { return klass()->is_refined_objArray_klass(); }
257
258 bool oopDesc::is_inline_type() const { return mark().is_inline_type(); }
259 #ifdef _LP64
260 bool oopDesc::is_flatArray() const {
261 markWord mrk = mark();
262 return (mrk.is_unlocked()) ? mrk.is_flat_array() : klass()->is_flatArray_klass();
263 }
264 bool oopDesc::is_null_free_array() const {
265 markWord mrk = mark();
266 return (mrk.is_unlocked()) ? mrk.is_null_free_array() : klass()->is_null_free_array_klass();
267 }
268 #else
269 bool oopDesc::is_flatArray() const { return klass()->is_flatArray_klass(); }
270 bool oopDesc::is_null_free_array() const { return klass()->is_null_free_array_klass(); }
271 #endif
272
273 template<typename T>
274 T* oopDesc::field_addr(int offset) const { return reinterpret_cast<T*>(cast_from_oop<intptr_t>(as_oop()) + offset); }
275
276 template <typename T>
277 size_t oopDesc::field_offset(T* p) const { return pointer_delta((void*)p, (void*)this, 1); }
278
279 template <DecoratorSet decorators>
280 inline oop oopDesc::obj_field_access(int offset) const { return HeapAccess<decorators>::oop_load_at(as_oop(), offset); }
281 inline oop oopDesc::obj_field(int offset) const { return HeapAccess<>::oop_load_at(as_oop(), offset); }
282
283 inline void oopDesc::obj_field_put(int offset, oop value) { HeapAccess<>::oop_store_at(as_oop(), offset, value); }
284 template <DecoratorSet decorators>
285 inline void oopDesc::obj_field_put_access(int offset, oop value) { HeapAccess<decorators>::oop_store_at(as_oop(), offset, value); }
286
287 inline jbyte oopDesc::byte_field(int offset) const { return *field_addr<jbyte>(offset); }
288 inline void oopDesc::byte_field_put(int offset, jbyte value) { *field_addr<jbyte>(offset) = value; }
289
290 inline jchar oopDesc::char_field(int offset) const { return *field_addr<jchar>(offset); }
291 inline void oopDesc::char_field_put(int offset, jchar value) { *field_addr<jchar>(offset) = value; }
292
293 inline jboolean oopDesc::bool_field(int offset) const { return *field_addr<jboolean>(offset); }
294 inline void oopDesc::bool_field_put(int offset, jboolean value) { *field_addr<jboolean>(offset) = jboolean(value & 1); }
295 inline jboolean oopDesc::bool_field_volatile(int offset) const { return RawAccess<MO_SEQ_CST>::load(field_addr<jboolean>(offset)); }
296 inline void oopDesc::bool_field_put_volatile(int offset, jboolean value) { RawAccess<MO_SEQ_CST>::store(field_addr<jboolean>(offset), jboolean(value & 1)); }
297 inline jshort oopDesc::short_field(int offset) const { return *field_addr<jshort>(offset); }
298 inline void oopDesc::short_field_put(int offset, jshort value) { *field_addr<jshort>(offset) = value; }
299
300 inline jint oopDesc::int_field(int offset) const { return *field_addr<jint>(offset); }
301 inline void oopDesc::int_field_put(int offset, jint value) { *field_addr<jint>(offset) = value; }
302 inline jint oopDesc::int_field_relaxed(int offset) const { return AtomicAccess::load(field_addr<jint>(offset)); }
303 inline void oopDesc::int_field_put_relaxed(int offset, jint value) { AtomicAccess::store(field_addr<jint>(offset), value); }
304
305 inline jlong oopDesc::long_field(int offset) const { return *field_addr<jlong>(offset); }
306 inline void oopDesc::long_field_put(int offset, jlong value) { *field_addr<jlong>(offset) = value; }
307
308 inline jfloat oopDesc::float_field(int offset) const { return *field_addr<jfloat>(offset); }
309 inline void oopDesc::float_field_put(int offset, jfloat value) { *field_addr<jfloat>(offset) = value; }
310
311 inline jdouble oopDesc::double_field(int offset) const { return *field_addr<jdouble>(offset); }
312 inline void oopDesc::double_field_put(int offset, jdouble value) { *field_addr<jdouble>(offset) = value; }
313
314 bool oopDesc::is_locked() const {
315 return mark().is_locked();
316 }
317
318 bool oopDesc::is_unlocked() const {
319 return mark().is_unlocked();
320 }
321
322 bool oopDesc::is_gc_marked() const {
323 return mark().is_marked();
324 }
325
326 // Used by scavengers
327 bool oopDesc::is_forwarded() const {
328 return mark().is_forwarded();
329 }
330
331 bool oopDesc::is_self_forwarded() const {
332 return mark().is_self_forwarded();
333 }
334
335 // Used by scavengers
336 void oopDesc::forward_to(oop p) {
337 assert(cast_from_oop<oopDesc*>(p) != this,
338 "must not be used for self-forwarding, use forward_to_self() instead");
339 markWord m = markWord::encode_pointer_as_mark(p);
340 assert(m.decode_pointer() == p, "encoding must be reversible");
341 set_mark(m);
342 }
343
344 void oopDesc::forward_to_self() {
345 set_mark(mark().set_self_forwarded());
346 }
347
348 oop oopDesc::cas_set_forwardee(markWord new_mark, markWord compare, atomic_memory_order order) {
349 markWord old_mark = cas_set_mark(new_mark, compare, order);
350 if (old_mark == compare) {
351 return nullptr;
352 } else {
353 assert(old_mark.is_forwarded(), "must be forwarded here");
354 return forwardee(old_mark);
355 }
356 }
357
358 oop oopDesc::forward_to_atomic(oop p, markWord compare, atomic_memory_order order) {
359 assert(cast_from_oop<oopDesc*>(p) != this,
360 "must not be used for self-forwarding, use forward_to_self_atomic() instead");
361 markWord m = markWord::encode_pointer_as_mark(p);
362 assert(forwardee(m) == p, "encoding must be reversible");
363 return cas_set_forwardee(m, compare, order);
364 }
365
366 oop oopDesc::forward_to_self_atomic(markWord old_mark, atomic_memory_order order) {
367 markWord new_mark = old_mark.set_self_forwarded();
368 assert(forwardee(new_mark) == cast_to_oop(this), "encoding must be reversible");
369 return cas_set_forwardee(new_mark, old_mark, order);
370 }
371
372 oop oopDesc::forwardee(markWord mark) const {
373 assert(mark.is_forwarded(), "only decode when actually forwarded");
374 if (mark.is_self_forwarded()) {
375 return cast_to_oop(this);
376 } else {
377 return mark.forwardee();
378 }
379 }
380
381 // Note that the forwardee is not the same thing as the displaced_mark.
382 // The forwardee is used when copying during scavenge and mark-sweep.
383 // It does need to clear the low two locking- and GC-related bits.
384 oop oopDesc::forwardee() const {
385 return forwardee(mark());
386 }
387
388 void oopDesc::unset_self_forwarded() {
389 set_mark(mark().unset_self_forwarded());
390 }
391
392 // The following method needs to be MT safe.
393 uint oopDesc::age() const {
394 markWord m = mark();
395 assert(!m.is_marked(), "Attempt to read age from forwarded mark");
396 if (m.has_displaced_mark_helper()) {
397 return m.displaced_mark_helper().age();
398 } else {
399 return m.age();
400 }
401 }
402
403 void oopDesc::incr_age() {
404 markWord m = mark();
405 assert(!m.is_marked(), "Attempt to increment age of forwarded mark");
406 if (m.has_displaced_mark_helper()) {
407 m.set_displaced_mark_helper(m.displaced_mark_helper().incr_age());
408 } else {
409 set_mark(m.incr_age());
410 }
411 }
412
413 template <typename OopClosureType>
414 void oopDesc::oop_iterate(OopClosureType* cl) {
415 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass());
416 }
417
418 template <typename OopClosureType>
419 void oopDesc::oop_iterate(OopClosureType* cl, MemRegion mr) {
420 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass(), mr);
421 }
422
423 template <typename OopClosureType>
424 size_t oopDesc::oop_iterate_size(OopClosureType* cl) {
425 Klass* k = klass();
426 size_t size = size_given_klass(k);
427 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k);
428 return size;
429 }
430
431 template <typename OopClosureType>
432 size_t oopDesc::oop_iterate_size(OopClosureType* cl, MemRegion mr) {
433 Klass* k = klass();
434 size_t size = size_given_klass(k);
435 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k, mr);
436 return size;
437 }
438
439 template <typename OopClosureType>
440 void oopDesc::oop_iterate_backwards(OopClosureType* cl) {
441 oop_iterate_backwards(cl, klass());
442 }
443
444 template <typename OopClosureType>
445 void oopDesc::oop_iterate_backwards(OopClosureType* cl, Klass* k) {
446 // In this assert, we cannot safely access the Klass* with compact headers.
447 assert(k == klass(), "wrong klass");
448 OopIteratorClosureDispatch::oop_oop_iterate_backwards(cl, this, k);
449 }
450
451 bool oopDesc::is_instanceof_or_null(oop obj, Klass* klass) {
452 return obj == nullptr || obj->klass()->is_subtype_of(klass);
453 }
454
455 intptr_t oopDesc::identity_hash() {
456 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
457 // Note: The mark must be read into local variable to avoid concurrent updates.
458 markWord mrk = mark();
459 if (mrk.is_unlocked() && !mrk.has_no_hash()) {
460 return mrk.hash();
461 } else if (mrk.is_marked()) {
462 return mrk.hash();
463 } else {
464 return slow_identity_hash();
465 }
466 }
467
468 // This checks fast simple case of whether the oop has_no_hash,
469 // to optimize JVMTI table lookup.
470 bool oopDesc::fast_no_hash_check() {
471 markWord mrk = mark_acquire();
472 assert(!mrk.is_marked(), "should never be marked");
473 return mrk.is_unlocked() && mrk.has_no_hash();
474 }
475
476 bool oopDesc::has_displaced_mark() const {
477 return mark().has_displaced_mark_helper();
478 }
479
480 markWord oopDesc::displaced_mark() const {
481 return mark().displaced_mark_helper();
482 }
483
484 void oopDesc::set_displaced_mark(markWord m) {
485 mark().set_displaced_mark_helper(m);
486 }
487
488 bool oopDesc::mark_must_be_preserved() const {
489 return mark_must_be_preserved(mark());
490 }
491
492 bool oopDesc::mark_must_be_preserved(markWord m) const {
493 return m.must_be_preserved();
494 }
495
496 #endif // SHARE_OOPS_OOP_INLINE_HPP
--- EOF ---