1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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13 * accompanied this code).
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23 */
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) {
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 switch (ObjLayout::klass_mode()) {
99 case ObjLayout::Compact:
100 return mark().klass();
101 case ObjLayout::Compressed:
102 return CompressedKlassPointers::decode_not_null(_compressed_klass);
103 default:
104 ShouldNotReachHere();
105 }
106 }
107
108 Klass* oopDesc::klass_or_null() const {
109 switch (ObjLayout::klass_mode()) {
110 case ObjLayout::Compact:
111 return mark().klass_or_null();
112 case ObjLayout::Compressed:
113 return CompressedKlassPointers::decode(_compressed_klass);
114 default:
115 ShouldNotReachHere();
116 }
117 }
118
119 Klass* oopDesc::klass_or_null_acquire() const {
120 switch (ObjLayout::klass_mode()) {
121 case ObjLayout::Compact:
122 return mark_acquire().klass();
123 case ObjLayout::Compressed: {
124 narrowKlass narrow_klass = AtomicAccess::load_acquire(&_compressed_klass);
125 return CompressedKlassPointers::decode(narrow_klass);
126 }
127 default:
128 ShouldNotReachHere();
129 }
130 }
131
132 Klass* oopDesc::klass_without_asserts() const {
133 switch (ObjLayout::klass_mode()) {
134 case ObjLayout::Compact:
135 return mark().klass_without_asserts();
136 case ObjLayout::Compressed:
137 return CompressedKlassPointers::decode_without_asserts(_compressed_klass);
138 default:
139 ShouldNotReachHere();
140 }
141 }
142
143 narrowKlass oopDesc::narrow_klass() const {
144 switch (ObjLayout::klass_mode()) {
145 case ObjLayout::Compact:
146 return mark().narrow_klass();
147 case ObjLayout::Compressed:
148 return _compressed_klass;
149 default:
150 ShouldNotReachHere();
151 }
152 }
153
154 void oopDesc::set_klass(Klass* k) {
155 assert(Universe::is_bootstrapping() || (k != nullptr && k->is_klass()), "incorrect Klass");
156 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
157 _compressed_klass = CompressedKlassPointers::encode_not_null(k);
158 }
159
160 void oopDesc::release_set_klass(HeapWord* mem, Klass* k) {
161 assert(Universe::is_bootstrapping() || (k != nullptr && k->is_klass()), "incorrect Klass");
162 assert(!UseCompactObjectHeaders, "don't set Klass* with compact headers");
163 char* raw_mem = ((char*)mem + klass_offset_in_bytes());
164 AtomicAccess::release_store((narrowKlass*)raw_mem, CompressedKlassPointers::encode_not_null(k));
165 }
166
167 void oopDesc::set_klass_gap(HeapWord* mem, int v) {
168 assert(has_klass_gap(), "precondition");
169 *(int*)(((char*)mem) + klass_gap_offset_in_bytes()) = v;
170 }
171
172 bool oopDesc::is_a(Klass* k) const {
173 return klass()->is_subtype_of(k);
174 }
175
176 size_t oopDesc::size() {
177 return size_given_klass(klass());
178 }
179
180 size_t oopDesc::size_given_klass(Klass* klass) {
181 int lh = klass->layout_helper();
182 size_t s;
183
184 // lh is now a value computed at class initialization that may hint
185 // at the size. For instances, this is positive and equal to the
186 // size. For arrays, this is negative and provides log2 of the
187 // array element size. For other oops, it is zero and thus requires
188 // a virtual call.
189 //
190 // We go to all this trouble because the size computation is at the
191 // heart of phase 2 of mark-compaction, and called for every object,
192 // alive or dead. So the speed here is equal in importance to the
193 // speed of allocation.
194
195 if (lh > Klass::_lh_neutral_value) {
196 if (!Klass::layout_helper_needs_slow_path(lh)) {
197 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
198 } else {
199 s = klass->oop_size(this);
200 }
201 } else if (lh <= Klass::_lh_neutral_value) {
202 // The most common case is instances; fall through if so.
203 if (lh < Klass::_lh_neutral_value) {
204 // Second most common case is arrays. We have to fetch the
205 // length of the array, shift (multiply) it appropriately,
206 // up to wordSize, add the header, and align to object size.
207 size_t size_in_bytes;
208 size_t array_length = (size_t) ((arrayOop)this)->length();
209 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
210 size_in_bytes += Klass::layout_helper_header_size(lh);
211
212 // This code could be simplified, but by keeping array_header_in_bytes
213 // in units of bytes and doing it this way we can round up just once,
214 // skipping the intermediate round to HeapWordSize.
215 s = align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize;
216
217 assert(s == klass->oop_size(this), "wrong array object size");
218 } else {
219 // Must be zero, so bite the bullet and take the virtual call.
220 s = klass->oop_size(this);
221 }
222 }
223
224 assert(s > 0, "Oop size must be greater than zero, not %zu", s);
225 assert(is_object_aligned(s), "Oop size is not properly aligned: %zu", s);
226 return s;
227 }
228
229 bool oopDesc::is_instance() const { return klass()->is_instance_klass(); }
230 bool oopDesc::is_instanceRef() const { return klass()->is_reference_instance_klass(); }
231 bool oopDesc::is_stackChunk() const { return klass()->is_stack_chunk_instance_klass(); }
232 bool oopDesc::is_array() const { return klass()->is_array_klass(); }
233 bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); }
234 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); }
235
236 template<typename T>
237 T* oopDesc::field_addr(int offset) const { return reinterpret_cast<T*>(cast_from_oop<intptr_t>(as_oop()) + offset); }
238
239 template <typename T>
240 size_t oopDesc::field_offset(T* p) const { return pointer_delta((void*)p, (void*)this, 1); }
241
242 template <DecoratorSet decorators>
243 inline oop oopDesc::obj_field_access(int offset) const { return HeapAccess<decorators>::oop_load_at(as_oop(), offset); }
244 inline oop oopDesc::obj_field(int offset) const { return HeapAccess<>::oop_load_at(as_oop(), offset); }
245
246 inline void oopDesc::obj_field_put(int offset, oop value) { HeapAccess<>::oop_store_at(as_oop(), offset, value); }
247 template <DecoratorSet decorators>
248 inline void oopDesc::obj_field_put_access(int offset, oop value) { HeapAccess<decorators>::oop_store_at(as_oop(), offset, value); }
249
250 inline jbyte oopDesc::byte_field(int offset) const { return *field_addr<jbyte>(offset); }
251 inline void oopDesc::byte_field_put(int offset, jbyte value) { *field_addr<jbyte>(offset) = value; }
252
253 inline jchar oopDesc::char_field(int offset) const { return *field_addr<jchar>(offset); }
254 inline void oopDesc::char_field_put(int offset, jchar value) { *field_addr<jchar>(offset) = value; }
255
256 inline jboolean oopDesc::bool_field(int offset) const { return *field_addr<jboolean>(offset); }
257 inline void oopDesc::bool_field_put(int offset, jboolean value) { *field_addr<jboolean>(offset) = jboolean(value & 1); }
258 inline jboolean oopDesc::bool_field_volatile(int offset) const { return RawAccess<MO_SEQ_CST>::load(field_addr<jboolean>(offset)); }
259 inline void oopDesc::bool_field_put_volatile(int offset, jboolean value) { RawAccess<MO_SEQ_CST>::store(field_addr<jboolean>(offset), jboolean(value & 1)); }
260 inline jshort oopDesc::short_field(int offset) const { return *field_addr<jshort>(offset); }
261 inline void oopDesc::short_field_put(int offset, jshort value) { *field_addr<jshort>(offset) = value; }
262
263 inline jint oopDesc::int_field(int offset) const { return *field_addr<jint>(offset); }
264 inline void oopDesc::int_field_put(int offset, jint value) { *field_addr<jint>(offset) = value; }
265 inline jint oopDesc::int_field_relaxed(int offset) const { return AtomicAccess::load(field_addr<jint>(offset)); }
266 inline void oopDesc::int_field_put_relaxed(int offset, jint value) { AtomicAccess::store(field_addr<jint>(offset), value); }
267
268 inline jlong oopDesc::long_field(int offset) const { return *field_addr<jlong>(offset); }
269 inline void oopDesc::long_field_put(int offset, jlong value) { *field_addr<jlong>(offset) = value; }
270
271 inline jfloat oopDesc::float_field(int offset) const { return *field_addr<jfloat>(offset); }
272 inline void oopDesc::float_field_put(int offset, jfloat value) { *field_addr<jfloat>(offset) = value; }
273
274 inline jdouble oopDesc::double_field(int offset) const { return *field_addr<jdouble>(offset); }
275 inline void oopDesc::double_field_put(int offset, jdouble value) { *field_addr<jdouble>(offset) = value; }
276
277 bool oopDesc::is_locked() const {
278 return mark().is_locked();
279 }
280
281 bool oopDesc::is_unlocked() const {
282 return mark().is_unlocked();
283 }
284
285 bool oopDesc::is_gc_marked() const {
286 return mark().is_marked();
287 }
288
289 // Used by scavengers
290 bool oopDesc::is_forwarded() const {
291 return mark().is_forwarded();
292 }
293
294 bool oopDesc::is_self_forwarded() const {
295 return mark().is_self_forwarded();
296 }
297
298 // Used by scavengers
299 void oopDesc::forward_to(oop p) {
300 assert(cast_from_oop<oopDesc*>(p) != this,
301 "must not be used for self-forwarding, use forward_to_self() instead");
302 markWord m = markWord::encode_pointer_as_mark(p);
303 assert(m.decode_pointer() == p, "encoding must be reversible");
304 set_mark(m);
305 }
306
307 void oopDesc::forward_to_self() {
308 set_mark(mark().set_self_forwarded());
309 }
310
311 oop oopDesc::cas_set_forwardee(markWord new_mark, markWord compare, atomic_memory_order order) {
312 markWord old_mark = cas_set_mark(new_mark, compare, order);
313 if (old_mark == compare) {
314 return nullptr;
315 } else {
316 assert(old_mark.is_forwarded(), "must be forwarded here");
317 return forwardee(old_mark);
318 }
319 }
320
321 oop oopDesc::forward_to_atomic(oop p, markWord compare, atomic_memory_order order) {
322 assert(cast_from_oop<oopDesc*>(p) != this,
323 "must not be used for self-forwarding, use forward_to_self_atomic() instead");
324 markWord m = markWord::encode_pointer_as_mark(p);
325 assert(forwardee(m) == p, "encoding must be reversible");
326 return cas_set_forwardee(m, compare, order);
327 }
328
329 oop oopDesc::forward_to_self_atomic(markWord old_mark, atomic_memory_order order) {
330 markWord new_mark = old_mark.set_self_forwarded();
331 assert(forwardee(new_mark) == cast_to_oop(this), "encoding must be reversible");
332 return cas_set_forwardee(new_mark, old_mark, order);
333 }
334
335 oop oopDesc::forwardee(markWord mark) const {
336 assert(mark.is_forwarded(), "only decode when actually forwarded");
337 if (mark.is_self_forwarded()) {
338 return cast_to_oop(this);
339 } else {
340 return mark.forwardee();
341 }
342 }
343
344 // Note that the forwardee is not the same thing as the displaced_mark.
345 // The forwardee is used when copying during scavenge and mark-sweep.
346 // It does need to clear the low two locking- and GC-related bits.
347 oop oopDesc::forwardee() const {
348 return forwardee(mark());
349 }
350
351 void oopDesc::unset_self_forwarded() {
352 set_mark(mark().unset_self_forwarded());
353 }
354
355 // The following method needs to be MT safe.
356 uint oopDesc::age() const {
357 markWord m = mark();
358 assert(!m.is_marked(), "Attempt to read age from forwarded mark");
359 if (m.has_displaced_mark_helper()) {
360 return m.displaced_mark_helper().age();
361 } else {
362 return m.age();
363 }
364 }
365
366 void oopDesc::incr_age() {
367 markWord m = mark();
368 assert(!m.is_marked(), "Attempt to increment age of forwarded mark");
369 if (m.has_displaced_mark_helper()) {
370 m.set_displaced_mark_helper(m.displaced_mark_helper().incr_age());
371 } else {
372 set_mark(m.incr_age());
373 }
374 }
375
376 template <typename OopClosureType>
377 void oopDesc::oop_iterate(OopClosureType* cl) {
378 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass());
379 }
380
381 template <typename OopClosureType>
382 void oopDesc::oop_iterate(OopClosureType* cl, MemRegion mr) {
383 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass(), mr);
384 }
385
386 template <typename OopClosureType>
387 size_t oopDesc::oop_iterate_size(OopClosureType* cl) {
388 Klass* k = klass();
389 size_t size = size_given_klass(k);
390 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k);
391 return size;
392 }
393
394 template <typename OopClosureType>
395 size_t oopDesc::oop_iterate_size(OopClosureType* cl, MemRegion mr) {
396 Klass* k = klass();
397 size_t size = size_given_klass(k);
398 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k, mr);
399 return size;
400 }
401
402 template <typename OopClosureType>
403 void oopDesc::oop_iterate_backwards(OopClosureType* cl) {
404 oop_iterate_backwards(cl, klass());
405 }
406
407 template <typename OopClosureType>
408 void oopDesc::oop_iterate_backwards(OopClosureType* cl, Klass* k) {
409 // In this assert, we cannot safely access the Klass* with compact headers.
410 assert(k == klass(), "wrong klass");
411 OopIteratorClosureDispatch::oop_oop_iterate_backwards(cl, this, k);
412 }
413
414 bool oopDesc::is_instanceof_or_null(oop obj, Klass* klass) {
415 return obj == nullptr || obj->klass()->is_subtype_of(klass);
416 }
417
418 intptr_t oopDesc::identity_hash() {
419 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
420 // Note: The mark must be read into local variable to avoid concurrent updates.
421 markWord mrk = mark();
422 if (mrk.is_unlocked() && !mrk.has_no_hash()) {
423 return mrk.hash();
424 } else if (mrk.is_marked()) {
425 return mrk.hash();
426 } else {
427 return slow_identity_hash();
428 }
429 }
430
431 // This checks fast simple case of whether the oop has_no_hash,
432 // to optimize JVMTI table lookup.
433 bool oopDesc::fast_no_hash_check() {
434 markWord mrk = mark_acquire();
435 assert(!mrk.is_marked(), "should never be marked");
436 return mrk.is_unlocked() && mrk.has_no_hash();
437 }
438
439 bool oopDesc::has_displaced_mark() const {
440 return mark().has_displaced_mark_helper();
441 }
442
443 markWord oopDesc::displaced_mark() const {
444 return mark().displaced_mark_helper();
445 }
446
447 void oopDesc::set_displaced_mark(markWord m) {
448 mark().set_displaced_mark_helper(m);
449 }
450
451 bool oopDesc::mark_must_be_preserved() const {
452 return mark_must_be_preserved(mark());
453 }
454
455 bool oopDesc::mark_must_be_preserved(markWord m) const {
456 return m.must_be_preserved();
457 }
458
459 #endif // SHARE_OOPS_OOP_INLINE_HPP