1 /*
2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25 #ifndef SHARE_VM_OOPS_OOP_INLINE_HPP
26 #define SHARE_VM_OOPS_OOP_INLINE_HPP
27
28 #include "gc/shared/ageTable.hpp"
29 #include "gc/shared/barrierSet.inline.hpp"
30 #include "gc/shared/cardTableModRefBS.hpp"
31 #include "gc/shared/collectedHeap.inline.hpp"
32 #include "gc/shared/genCollectedHeap.hpp"
33 #include "gc/shared/generation.hpp"
34 #include "memory/vtBuffer.hpp"
35 #include "oops/arrayKlass.hpp"
36 #include "oops/arrayOop.hpp"
37 #include "oops/klass.inline.hpp"
38 #include "oops/markOop.inline.hpp"
39 #include "oops/oop.hpp"
40 #include "runtime/atomic.hpp"
41 #include "runtime/orderAccess.inline.hpp"
42 #include "runtime/os.hpp"
43 #include "utilities/macros.hpp"
44
45 inline void update_barrier_set(void* p, oop v, bool release = false) {
46 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
47 oopDesc::bs()->write_ref_field(p, v, release);
48 }
49
50 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
51 oopDesc::bs()->write_ref_field_pre(p, v);
52 }
53
54 template <class T> void oop_store(T* p, oop v) {
55 if (always_do_update_barrier) {
56 oop_store((volatile T*)p, v);
57 } else {
58 update_barrier_set_pre(p, v);
59 oopDesc::encode_store_heap_oop(p, v);
60 // always_do_update_barrier == false =>
61 // Either we are at a safepoint (in GC) or CMS is not used. In both
62 // cases it's unnecessary to mark the card as dirty with release sematics.
63 update_barrier_set((void*)p, v, false /* release */); // cast away type
64 }
65 }
66
67 template <class T> void oop_store(volatile T* p, oop v) {
68 update_barrier_set_pre((T*)p, v); // cast away volatile
69 // Used by release_obj_field_put, so use release_store_ptr.
70 oopDesc::release_encode_store_heap_oop(p, v);
71 // When using CMS we must mark the card corresponding to p as dirty
72 // with release sematics to prevent that CMS sees the dirty card but
73 // not the new value v at p due to reordering of the two
74 // stores. Note that CMS has a concurrent precleaning phase, where
75 // it reads the card table while the Java threads are running.
76 update_barrier_set((void*)p, v, true /* release */); // cast away type
77 }
78
79 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
80 // (without having to remember the function name this calls).
81 inline void oop_store_raw(HeapWord* addr, oop value) {
82 if (UseCompressedOops) {
83 oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
84 } else {
85 oopDesc::encode_store_heap_oop((oop*)addr, value);
86 }
87 }
88
89 // Implementation of all inlined member functions defined in oop.hpp
90 // We need a separate file to avoid circular references
91
92 void oopDesc::release_set_mark(markOop m) {
93 OrderAccess::release_store_ptr(&_mark, m);
94 }
95
96 markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
97 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
98 }
99
100 void oopDesc::init_mark() {
101 set_mark(markOopDesc::prototype_for_object(this));
102 }
103
104 Klass* oopDesc::klass() const {
105 if (UseCompressedClassPointers) {
106 return Klass::decode_klass_not_null(_metadata._compressed_klass);
107 } else {
108 return _metadata._klass;
109 }
110 }
111
112 Klass* oopDesc::klass_or_null() const volatile {
113 if (UseCompressedClassPointers) {
114 return Klass::decode_klass(_metadata._compressed_klass);
115 } else {
116 return _metadata._klass;
117 }
118 }
119
120 Klass* oopDesc::klass_or_null_acquire() const volatile {
121 if (UseCompressedClassPointers) {
122 // Workaround for non-const load_acquire parameter.
123 const volatile narrowKlass* addr = &_metadata._compressed_klass;
124 volatile narrowKlass* xaddr = const_cast<volatile narrowKlass*>(addr);
125 return Klass::decode_klass(OrderAccess::load_acquire(xaddr));
126 } else {
127 return (Klass*)OrderAccess::load_ptr_acquire(&_metadata._klass);
128 }
129 }
130
131 Klass** oopDesc::klass_addr() {
132 // Only used internally and with CMS and will not work with
133 // UseCompressedOops
134 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers");
135 return (Klass**) &_metadata._klass;
136 }
137
138 narrowKlass* oopDesc::compressed_klass_addr() {
139 assert(UseCompressedClassPointers, "only called by compressed klass pointers");
140 return &_metadata._compressed_klass;
141 }
142
143 #define CHECK_SET_KLASS(k) \
144 do { \
145 assert(Universe::is_bootstrapping() || k != NULL, "NULL Klass"); \
146 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass"); \
147 } while (0)
148
149 void oopDesc::set_klass(Klass* k) {
150 CHECK_SET_KLASS(k);
151 if (UseCompressedClassPointers) {
152 *compressed_klass_addr() = Klass::encode_klass_not_null(k);
153 } else {
154 *klass_addr() = k;
155 }
156 }
157
158 void oopDesc::release_set_klass(Klass* k) {
159 CHECK_SET_KLASS(k);
160 if (UseCompressedClassPointers) {
161 OrderAccess::release_store(compressed_klass_addr(),
162 Klass::encode_klass_not_null(k));
163 } else {
164 OrderAccess::release_store_ptr(klass_addr(), k);
165 }
166 }
167
168 #undef CHECK_SET_KLASS
169
170 int oopDesc::klass_gap() const {
171 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
172 }
173
174 void oopDesc::set_klass_gap(int v) {
175 if (UseCompressedClassPointers) {
176 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
177 }
178 }
179
180 void oopDesc::set_klass_to_list_ptr(oop k) {
181 // This is only to be used during GC, for from-space objects, so no
182 // barrier is needed.
183 if (UseCompressedClassPointers) {
184 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling)
185 } else {
186 _metadata._klass = (Klass*)(address)k;
187 }
188 }
189
190 oop oopDesc::list_ptr_from_klass() {
191 // This is only to be used during GC, for from-space objects.
192 if (UseCompressedClassPointers) {
193 return decode_heap_oop((narrowOop)_metadata._compressed_klass);
194 } else {
195 // Special case for GC
196 return (oop)(address)_metadata._klass;
197 }
198 }
199
200 bool oopDesc::is_a(Klass* k) const {
201 return klass()->is_subtype_of(k);
202 }
203
204 int oopDesc::size() {
205 return size_given_klass(klass());
206 }
207
208 int oopDesc::size_given_klass(Klass* klass) {
209 int lh = klass->layout_helper();
210 int s;
211
212 // lh is now a value computed at class initialization that may hint
213 // at the size. For instances, this is positive and equal to the
214 // size. For arrays, this is negative and provides log2 of the
215 // array element size. For other oops, it is zero and thus requires
216 // a virtual call.
217 //
218 // We go to all this trouble because the size computation is at the
219 // heart of phase 2 of mark-compaction, and called for every object,
220 // alive or dead. So the speed here is equal in importance to the
221 // speed of allocation.
222
223 if (lh > Klass::_lh_neutral_value) {
224 if (!Klass::layout_helper_needs_slow_path(lh)) {
225 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
226 } else {
227 s = klass->oop_size(this);
228 }
229 } else if (lh <= Klass::_lh_neutral_value) {
230 // The most common case is instances; fall through if so.
231 if (lh < Klass::_lh_neutral_value) {
232 // Second most common case is arrays. We have to fetch the
233 // length of the array, shift (multiply) it appropriately,
234 // up to wordSize, add the header, and align to object size.
235 size_t size_in_bytes;
236 #ifdef _M_IA64
237 // The Windows Itanium Aug 2002 SDK hoists this load above
238 // the check for s < 0. An oop at the end of the heap will
239 // cause an access violation if this load is performed on a non
240 // array oop. Making the reference volatile prohibits this.
241 // (%%% please explain by what magic the length is actually fetched!)
242 volatile int *array_length;
243 array_length = (volatile int *)( (intptr_t)this +
244 arrayOopDesc::length_offset_in_bytes() );
245 assert(array_length > 0, "Integer arithmetic problem somewhere");
246 // Put into size_t to avoid overflow.
247 size_in_bytes = (size_t) array_length;
248 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
249 #else
250 size_t array_length = (size_t) ((arrayOop)this)->length();
251 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
252 #endif
253 size_in_bytes += Klass::layout_helper_header_size(lh);
254
255 // This code could be simplified, but by keeping array_header_in_bytes
256 // in units of bytes and doing it this way we can round up just once,
257 // skipping the intermediate round to HeapWordSize. Cast the result
258 // of round_to to size_t to guarantee unsigned division == right shift.
259 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
260 HeapWordSize);
261
262 // ParNew (used by CMS), UseParallelGC and UseG1GC can change the length field
263 // of an "old copy" of an object array in the young gen so it indicates
264 // the grey portion of an already copied array. This will cause the first
265 // disjunct below to fail if the two comparands are computed across such
266 // a concurrent change.
267 // ParNew also runs with promotion labs (which look like int
268 // filler arrays) which are subject to changing their declared size
269 // when finally retiring a PLAB; this also can cause the first disjunct
270 // to fail for another worker thread that is concurrently walking the block
271 // offset table. Both these invariant failures are benign for their
272 // current uses; we relax the assertion checking to cover these two cases below:
273 // is_objArray() && is_forwarded() // covers first scenario above
274 // || is_typeArray() // covers second scenario above
275 // If and when UseParallelGC uses the same obj array oop stealing/chunking
276 // technique, we will need to suitably modify the assertion.
277 assert((s == klass->oop_size(this)) ||
278 (Universe::heap()->is_gc_active() &&
279 ((is_typeArray() && UseConcMarkSweepGC) ||
280 (is_objArray() && is_forwarded() && (UseConcMarkSweepGC || UseParallelGC || UseG1GC)))),
281 "wrong array object size");
282 } else {
283 // Must be zero, so bite the bullet and take the virtual call.
284 s = klass->oop_size(this);
285 }
286 }
287
288 assert(s % MinObjAlignment == 0, "Oop size is not properly aligned: %d", s);
289 assert(s > 0, "Oop size must be greater than zero, not %d", s);
290 return s;
291 }
292
293 bool oopDesc::is_instance() const { return klass()->is_instance_klass(); }
294 bool oopDesc::is_array() const { return klass()->is_array_klass(); }
295 bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); }
296 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); }
297 bool oopDesc::is_value() const { return klass()->is_value(); }
298 bool oopDesc::is_valueArray() const { return klass()->is_valueArray_klass(); }
299
300 void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; }
301
302 jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); }
303 jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); }
304 jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*) field_base(offset); }
305 jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); }
306 jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); }
307 jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); }
308 jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); }
309 jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
310 Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
311
312 template <class T> T* oopDesc::obj_field_addr(int offset) const { return (T*) field_base(offset); }
313 address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
314
315
316 // Functions for getting and setting oops within instance objects.
317 // If the oops are compressed, the type passed to these overloaded functions
318 // is narrowOop. All functions are overloaded so they can be called by
319 // template functions without conditionals (the compiler instantiates via
320 // the right type and inlines the appopriate code).
321
322 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
323 // offset from the heap base. Saving the check for null can save instructions
324 // in inner GC loops so these are separated.
325
326 inline bool check_obj_alignment(oop obj) {
327 return (cast_from_oop<intptr_t>(obj) & MinObjAlignmentInBytesMask) == 0;
328 }
329
330 oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
331 assert(!is_null(v), "narrow oop value can never be zero");
332 address base = Universe::narrow_oop_base();
333 int shift = Universe::narrow_oop_shift();
334 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
335 assert(check_obj_alignment(result), "address not aligned: " INTPTR_FORMAT, p2i((void*) result));
336 return result;
337 }
338
339 oop oopDesc::decode_heap_oop(narrowOop v) {
340 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
341 }
342
343 narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
344 assert(!is_null(v), "oop value can never be zero");
345 assert(check_obj_alignment(v), "Address not aligned");
346 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
347 address base = Universe::narrow_oop_base();
348 int shift = Universe::narrow_oop_shift();
349 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
350 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
351 uint64_t result = pd >> shift;
352 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
353 assert(decode_heap_oop(result) == v, "reversibility");
354 return (narrowOop)result;
355 }
356
357 narrowOop oopDesc::encode_heap_oop(oop v) {
358 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
359 }
360
361 // Load and decode an oop out of the Java heap into a wide oop.
362 oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
363 return decode_heap_oop_not_null(*p);
364 }
365
366 // Load and decode an oop out of the heap accepting null
367 oop oopDesc::load_decode_heap_oop(narrowOop* p) {
368 return decode_heap_oop(*p);
369 }
370
371 // Encode and store a heap oop.
372 void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
373 *p = encode_heap_oop_not_null(v);
374 }
375
376 // Encode and store a heap oop allowing for null.
377 void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
378 *p = encode_heap_oop(v);
379 }
380
381 // Store heap oop as is for volatile fields.
382 void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
383 OrderAccess::release_store_ptr(p, v);
384 }
385 void oopDesc::release_store_heap_oop(volatile narrowOop* p, narrowOop v) {
386 OrderAccess::release_store(p, v);
387 }
388
389 void oopDesc::release_encode_store_heap_oop_not_null(volatile narrowOop* p, oop v) {
390 // heap oop is not pointer sized.
391 OrderAccess::release_store(p, encode_heap_oop_not_null(v));
392 }
393 void oopDesc::release_encode_store_heap_oop_not_null(volatile oop* p, oop v) {
394 OrderAccess::release_store_ptr(p, v);
395 }
396
397 void oopDesc::release_encode_store_heap_oop(volatile oop* p, oop v) {
398 OrderAccess::release_store_ptr(p, v);
399 }
400 void oopDesc::release_encode_store_heap_oop(volatile narrowOop* p, oop v) {
401 OrderAccess::release_store(p, encode_heap_oop(v));
402 }
403
404 // These functions are only used to exchange oop fields in instances,
405 // not headers.
406 oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
407 if (UseCompressedOops) {
408 // encode exchange value from oop to T
409 narrowOop val = encode_heap_oop(exchange_value);
410 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
411 // decode old from T to oop
412 return decode_heap_oop(old);
413 } else {
414 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
415 }
416 }
417
418 oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
419 volatile HeapWord *dest,
420 oop compare_value,
421 bool prebarrier) {
422 if (UseCompressedOops) {
423 if (prebarrier) {
424 update_barrier_set_pre((narrowOop*)dest, exchange_value);
425 }
426 // encode exchange and compare value from oop to T
427 narrowOop val = encode_heap_oop(exchange_value);
428 narrowOop cmp = encode_heap_oop(compare_value);
429
430 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
431 // decode old from T to oop
432 return decode_heap_oop(old);
433 } else {
434 if (prebarrier) {
435 update_barrier_set_pre((oop*)dest, exchange_value);
436 }
437 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
438 }
439 }
440
441 // In order to put or get a field out of an instance, must first check
442 // if the field has been compressed and uncompress it.
443 oop oopDesc::obj_field(int offset) const {
444 return UseCompressedOops ?
445 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
446 load_decode_heap_oop(obj_field_addr<oop>(offset));
447 }
448
449 void oopDesc::obj_field_put(int offset, oop value) {
450 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
451 oop_store(obj_field_addr<oop>(offset), value);
452 }
453
454 void oopDesc::obj_field_put_raw(int offset, oop value) {
455 UseCompressedOops ?
456 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
457 encode_store_heap_oop(obj_field_addr<oop>(offset), value);
458 }
459 void oopDesc::obj_field_put_volatile(int offset, oop value) {
460 OrderAccess::release();
461 obj_field_put(offset, value);
462 OrderAccess::fence();
463 }
464
465 Metadata* oopDesc::metadata_field(int offset) const { return *metadata_field_addr(offset); }
466 void oopDesc::metadata_field_put(int offset, Metadata* value) { *metadata_field_addr(offset) = value; }
467
468 jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); }
469 void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; }
470
471 jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); }
472 void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; }
473
474 jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); }
475 void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (((jint) contents) & 1); }
476
477 jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); }
478 void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; }
479
480 jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); }
481 void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;}
482
483 jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); }
484 void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; }
485
486 jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); }
487 void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; }
488
489 jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); }
490 void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
491
492 address oopDesc::address_field(int offset) const { return *address_field_addr(offset); }
493 void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
494
495 oop oopDesc::obj_field_acquire(int offset) const {
496 return UseCompressedOops ?
497 decode_heap_oop((narrowOop)
498 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
499 : decode_heap_oop((oop)
500 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
501 }
502 void oopDesc::release_obj_field_put(int offset, oop value) {
503 UseCompressedOops ?
504 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
505 oop_store((volatile oop*) obj_field_addr<oop>(offset), value);
506 }
507
508 jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); }
509 void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); }
510
511 jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); }
512 void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); }
513
514 jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); }
515 void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), (contents & 1)); }
516
517 jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); }
518 void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); }
519
520 jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
521 void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); }
522
523 jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); }
524 void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); }
525
526 jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); }
527 void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); }
528
529 jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); }
530 void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
531
532 address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
533 void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
534
535 bool oopDesc::is_locked() const {
536 return mark()->is_locked();
537 }
538
539 bool oopDesc::is_unlocked() const {
540 return mark()->is_unlocked();
541 }
542
543 bool oopDesc::has_bias_pattern() const {
544 return mark()->has_bias_pattern();
545 }
546
547 // used only for asserts
548 bool oopDesc::is_oop(bool ignore_mark_word) const {
549 oop obj = (oop) this;
550 if (!check_obj_alignment(obj)) return false;
551 if (!Universe::heap()->is_in_reserved(obj)) {
552 assert(obj->klass()->is_value(), "Only value type can be outside of the Java heap");
553 VTBufferChunk* chunk = VTBufferChunk::chunk(obj);
554 assert(chunk->is_valid(), "if not in the heap, should a buffered VT");
555 if (!VTBuffer::is_in_vt_buffer(obj)) return false;
556 }
557 // obj is aligned and accessible in heap
558 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false;
559
560 // Header verification: the mark is typically non-NULL. If we're
561 // at a safepoint, it must not be null.
562 // Outside of a safepoint, the header could be changing (for example,
563 // another thread could be inflating a lock on this object).
564 if (ignore_mark_word) {
565 return true;
566 }
567 if (mark() != NULL) {
568 return true;
569 }
570 return !SafepointSynchronize::is_at_safepoint()
571 || (obj->klass()->is_value() && !Universe::heap()->is_in_reserved(obj)) ;
572 }
573
574
575 // used only for asserts
576 bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
577 return this == NULL ? true : is_oop(ignore_mark_word);
578 }
579
580 #ifndef PRODUCT
581 // used only for asserts
582 bool oopDesc::is_unlocked_oop() const {
583 if (!Universe::heap()->is_in_reserved(this)) return false;
584 return mark()->is_unlocked();
585 }
586 #endif // PRODUCT
587
588 // Used only for markSweep, scavenging
589 bool oopDesc::is_gc_marked() const {
590 return mark()->is_marked();
591 }
592
593 bool oopDesc::is_scavengable() const {
594 return Universe::heap()->is_scavengable(this);
595 }
596
597 // Used by scavengers
598 bool oopDesc::is_forwarded() const {
599 // The extra heap check is needed since the obj might be locked, in which case the
600 // mark would point to a stack location and have the sentinel bit cleared
601 return mark()->is_marked();
602 }
603
604 // Used by scavengers
605 void oopDesc::forward_to(oop p) {
606 assert(check_obj_alignment(p),
607 "forwarding to something not aligned");
608 assert(Universe::heap()->is_in_reserved(p),
609 "forwarding to something not in heap");
610 markOop m = markOopDesc::encode_pointer_as_mark(p);
611 assert(m->decode_pointer() == p, "encoding must be reversable");
612 set_mark(m);
613 }
614
615 // Used by parallel scavengers
616 bool oopDesc::cas_forward_to(oop p, markOop compare) {
617 assert(check_obj_alignment(p),
618 "forwarding to something not aligned");
619 assert(Universe::heap()->is_in_reserved(p),
620 "forwarding to something not in heap");
621 markOop m = markOopDesc::encode_pointer_as_mark(p);
622 assert(m->decode_pointer() == p, "encoding must be reversable");
623 return cas_set_mark(m, compare) == compare;
624 }
625
626 #if INCLUDE_ALL_GCS
627 oop oopDesc::forward_to_atomic(oop p) {
628 markOop oldMark = mark();
629 markOop forwardPtrMark = markOopDesc::encode_pointer_as_mark(p);
630 markOop curMark;
631
632 assert(forwardPtrMark->decode_pointer() == p, "encoding must be reversable");
633 assert(sizeof(markOop) == sizeof(intptr_t), "CAS below requires this.");
634
635 while (!oldMark->is_marked()) {
636 curMark = (markOop)Atomic::cmpxchg_ptr(forwardPtrMark, &_mark, oldMark);
637 assert(is_forwarded(), "object should have been forwarded");
638 if (curMark == oldMark) {
639 return NULL;
640 }
641 // If the CAS was unsuccessful then curMark->is_marked()
642 // should return true as another thread has CAS'd in another
643 // forwarding pointer.
644 oldMark = curMark;
645 }
646 return forwardee();
647 }
648 #endif
649
650 // Note that the forwardee is not the same thing as the displaced_mark.
651 // The forwardee is used when copying during scavenge and mark-sweep.
652 // It does need to clear the low two locking- and GC-related bits.
653 oop oopDesc::forwardee() const {
654 return (oop) mark()->decode_pointer();
655 }
656
657 // The following method needs to be MT safe.
658 uint oopDesc::age() const {
659 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
660 if (has_displaced_mark()) {
661 return displaced_mark()->age();
662 } else {
663 return mark()->age();
664 }
665 }
666
667 void oopDesc::incr_age() {
668 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
669 if (has_displaced_mark()) {
670 set_displaced_mark(displaced_mark()->incr_age());
671 } else {
672 set_mark(mark()->incr_age());
673 }
674 }
675
676 #if INCLUDE_ALL_GCS
677 void oopDesc::pc_follow_contents(ParCompactionManager* cm) {
678 klass()->oop_pc_follow_contents(this, cm);
679 }
680
681 void oopDesc::pc_update_contents(ParCompactionManager* cm) {
682 Klass* k = klass();
683 if (!k->is_typeArray_klass()) {
684 // It might contain oops beyond the header, so take the virtual call.
685 k->oop_pc_update_pointers(this, cm);
686 }
687 // Else skip it. The TypeArrayKlass in the header never needs scavenging.
688 }
689
690 void oopDesc::ps_push_contents(PSPromotionManager* pm) {
691 Klass* k = klass();
692 if (!k->is_typeArray_klass()) {
693 // It might contain oops beyond the header, so take the virtual call.
694 k->oop_ps_push_contents(this, pm);
695 }
696 // Else skip it. The TypeArrayKlass in the header never needs scavenging.
697 }
698 #endif // INCLUDE_ALL_GCS
699
700 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
701 \
702 void oopDesc::oop_iterate(OopClosureType* blk) { \
703 klass()->oop_oop_iterate##nv_suffix(this, blk); \
704 } \
705 \
706 void oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
707 klass()->oop_oop_iterate_bounded##nv_suffix(this, blk, mr); \
708 }
709
710 #define OOP_ITERATE_SIZE_DEFN(OopClosureType, nv_suffix) \
711 \
712 int oopDesc::oop_iterate_size(OopClosureType* blk) { \
713 Klass* k = klass(); \
714 int size = size_given_klass(k); \
715 k->oop_oop_iterate##nv_suffix(this, blk); \
716 return size; \
717 } \
718 \
719 int oopDesc::oop_iterate_size(OopClosureType* blk, MemRegion mr) { \
720 Klass* k = klass(); \
721 int size = size_given_klass(k); \
722 k->oop_oop_iterate_bounded##nv_suffix(this, blk, mr); \
723 return size; \
724 }
725
726 int oopDesc::oop_iterate_no_header(OopClosure* blk) {
727 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
728 // the do_oop calls, but turns off all other features in ExtendedOopClosure.
729 NoHeaderExtendedOopClosure cl(blk);
730 return oop_iterate_size(&cl);
731 }
732
733 int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
734 NoHeaderExtendedOopClosure cl(blk);
735 return oop_iterate_size(&cl, mr);
736 }
737
738 #if INCLUDE_ALL_GCS
739 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
740 \
741 inline void oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
742 klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
743 }
744 #else
745 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)
746 #endif // INCLUDE_ALL_GCS
747
748 #define ALL_OOPDESC_OOP_ITERATE(OopClosureType, nv_suffix) \
749 OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
750 OOP_ITERATE_SIZE_DEFN(OopClosureType, nv_suffix) \
751 OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)
752
753 ALL_OOP_OOP_ITERATE_CLOSURES_1(ALL_OOPDESC_OOP_ITERATE)
754 ALL_OOP_OOP_ITERATE_CLOSURES_2(ALL_OOPDESC_OOP_ITERATE)
755
756 intptr_t oopDesc::identity_hash() {
757 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
758 // Note: The mark must be read into local variable to avoid concurrent updates.
759 markOop mrk = mark();
760 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
761 return mrk->hash();
762 } else if (mrk->is_marked()) {
763 return mrk->hash();
764 } else {
765 return slow_identity_hash();
766 }
767 }
768
769 bool oopDesc::has_displaced_mark() const {
770 return mark()->has_displaced_mark_helper();
771 }
772
773 markOop oopDesc::displaced_mark() const {
774 return mark()->displaced_mark_helper();
775 }
776
777 void oopDesc::set_displaced_mark(markOop m) {
778 mark()->set_displaced_mark_helper(m);
779 }
780
781 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP