1 /*
2 * Copyright (c) 1997, 2015, 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.
18 *
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
21 * questions.
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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_implementation/shared/ageTable.hpp"
29 #include "gc_interface/collectedHeap.inline.hpp"
30 #include "memory/barrierSet.inline.hpp"
31 #include "memory/cardTableModRefBS.hpp"
32 #include "memory/genCollectedHeap.hpp"
33 #include "memory/generation.hpp"
34 #include "oops/arrayKlass.hpp"
35 #include "oops/arrayOop.hpp"
36 #include "oops/klass.inline.hpp"
37 #include "oops/markOop.inline.hpp"
38 #include "oops/oop.hpp"
39 #include "runtime/atomic.inline.hpp"
40 #include "runtime/orderAccess.inline.hpp"
41 #include "runtime/os.hpp"
42 #include "utilities/macros.hpp"
43
44 // Implementation of all inlined member functions defined in oop.hpp
45 // We need a separate file to avoid circular references
46
47 inline void oopDesc::release_set_mark(markOop m) {
48 OrderAccess::release_store_ptr(&_mark, m);
49 }
50
51 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
52 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
53 }
54
55 inline Klass* oopDesc::klass() const {
56 if (UseCompressedClassPointers) {
57 return Klass::decode_klass_not_null(_metadata._compressed_klass);
58 } else {
59 return _metadata._klass;
60 }
61 }
62
63 inline Klass* oopDesc::klass_or_null() const volatile {
64 // can be NULL in CMS
65 if (UseCompressedClassPointers) {
66 return Klass::decode_klass(_metadata._compressed_klass);
67 } else {
68 return _metadata._klass;
69 }
70 }
71
72 inline Klass** oopDesc::klass_addr() {
73 // Only used internally and with CMS and will not work with
74 // UseCompressedOops
75 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers");
76 return (Klass**) &_metadata._klass;
77 }
78
79 inline narrowKlass* oopDesc::compressed_klass_addr() {
80 assert(UseCompressedClassPointers, "only called by compressed klass pointers");
81 return &_metadata._compressed_klass;
82 }
83
84 inline void oopDesc::set_klass(Klass* k) {
85 // since klasses are promoted no store check is needed
86 assert(Universe::is_bootstrapping() || k != NULL, "must be a real Klass*");
87 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass*");
88 if (UseCompressedClassPointers) {
89 *compressed_klass_addr() = Klass::encode_klass_not_null(k);
90 } else {
91 *klass_addr() = k;
92 }
93 }
94
95 inline int oopDesc::klass_gap() const {
96 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
97 }
98
99 inline void oopDesc::set_klass_gap(int v) {
100 if (UseCompressedClassPointers) {
101 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
102 }
103 }
104
105 inline void oopDesc::set_klass_to_list_ptr(oop k) {
106 // This is only to be used during GC, for from-space objects, so no
107 // barrier is needed.
108 if (UseCompressedClassPointers) {
109 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling)
110 } else {
111 _metadata._klass = (Klass*)(address)k;
112 }
113 }
114
115 inline oop oopDesc::list_ptr_from_klass() {
116 // This is only to be used during GC, for from-space objects.
117 if (UseCompressedClassPointers) {
118 return decode_heap_oop((narrowOop)_metadata._compressed_klass);
119 } else {
120 // Special case for GC
121 return (oop)(address)_metadata._klass;
122 }
123 }
124
125 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); }
126
127 inline bool oopDesc::is_a(Klass* k) const { return klass()->is_subtype_of(k); }
128
129 inline bool oopDesc::is_instance() const { return klass()->oop_is_instance(); }
130 inline bool oopDesc::is_instanceClassLoader() const { return klass()->oop_is_instanceClassLoader(); }
131 inline bool oopDesc::is_instanceMirror() const { return klass()->oop_is_instanceMirror(); }
132 inline bool oopDesc::is_instanceRef() const { return klass()->oop_is_instanceRef(); }
133 inline bool oopDesc::is_array() const { return klass()->oop_is_array(); }
134 inline bool oopDesc::is_objArray() const { return klass()->oop_is_objArray(); }
135 inline bool oopDesc::is_typeArray() const { return klass()->oop_is_typeArray(); }
136
137 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; }
138
139 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
140 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
141 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); }
142 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); }
143 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); }
144 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); }
145 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); }
146 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); }
147 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); }
148 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
149 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
150
151
152 // Functions for getting and setting oops within instance objects.
153 // If the oops are compressed, the type passed to these overloaded functions
154 // is narrowOop. All functions are overloaded so they can be called by
155 // template functions without conditionals (the compiler instantiates via
156 // the right type and inlines the appopriate code).
157
158 inline bool oopDesc::is_null(oop obj) { return obj == NULL; }
159 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }
160
161 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
162 // offset from the heap base. Saving the check for null can save instructions
163 // in inner GC loops so these are separated.
164
165 inline bool check_obj_alignment(oop obj) {
166 return cast_from_oop<intptr_t>(obj) % MinObjAlignmentInBytes == 0;
167 }
168
169 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
170 assert(!is_null(v), "oop value can never be zero");
171 assert(check_obj_alignment(v), "Address not aligned");
172 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
173 address base = Universe::narrow_oop_base();
174 int shift = Universe::narrow_oop_shift();
175 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
176 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
177 uint64_t result = pd >> shift;
178 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
179 assert(decode_heap_oop(result) == v, "reversibility");
180 return (narrowOop)result;
181 }
182
183 inline narrowOop oopDesc::encode_heap_oop(oop v) {
184 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
185 }
186
187 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
188 assert(!is_null(v), "narrow oop value can never be zero");
189 address base = Universe::narrow_oop_base();
190 int shift = Universe::narrow_oop_shift();
191 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
192 assert(check_obj_alignment(result), err_msg("address not aligned: " INTPTR_FORMAT, p2i((void*) result)));
193 return result;
194 }
195
196 inline oop oopDesc::decode_heap_oop(narrowOop v) {
197 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
198 }
199
200 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
201 inline oop oopDesc::decode_heap_oop(oop v) { return v; }
202
203 // Load an oop out of the Java heap as is without decoding.
204 // Called by GC to check for null before decoding.
205 inline oop oopDesc::load_heap_oop(oop* p) { return *p; }
206 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
207
208 // Load and decode an oop out of the Java heap into a wide oop.
209 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
210 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
211 return decode_heap_oop_not_null(*p);
212 }
213
214 // Load and decode an oop out of the heap accepting null
215 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
216 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
217 return decode_heap_oop(*p);
218 }
219
220 // Store already encoded heap oop into the heap.
221 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; }
222 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
223
224 // Encode and store a heap oop.
225 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
226 *p = encode_heap_oop_not_null(v);
227 }
228 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
229
230 // Encode and store a heap oop allowing for null.
231 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
232 *p = encode_heap_oop(v);
233 }
234 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
235
236 // Store heap oop as is for volatile fields.
237 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
238 OrderAccess::release_store_ptr(p, v);
239 }
240 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
241 narrowOop v) {
242 OrderAccess::release_store(p, v);
243 }
244
245 inline void oopDesc::release_encode_store_heap_oop_not_null(
246 volatile narrowOop* p, oop v) {
247 // heap oop is not pointer sized.
248 OrderAccess::release_store(p, encode_heap_oop_not_null(v));
249 }
250
251 inline void oopDesc::release_encode_store_heap_oop_not_null(
252 volatile oop* p, oop v) {
253 OrderAccess::release_store_ptr(p, v);
254 }
255
256 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
257 oop v) {
258 OrderAccess::release_store_ptr(p, v);
259 }
260 inline void oopDesc::release_encode_store_heap_oop(
261 volatile narrowOop* p, oop v) {
262 OrderAccess::release_store(p, encode_heap_oop(v));
263 }
264
265
266 // These functions are only used to exchange oop fields in instances,
267 // not headers.
268 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
269 if (UseCompressedOops) {
270 // encode exchange value from oop to T
271 narrowOop val = encode_heap_oop(exchange_value);
272 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
273 // decode old from T to oop
274 return decode_heap_oop(old);
275 } else {
276 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
277 }
278 }
279
280 // In order to put or get a field out of an instance, must first check
281 // if the field has been compressed and uncompress it.
282 inline oop oopDesc::obj_field(int offset) const {
283 return UseCompressedOops ?
284 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
285 load_decode_heap_oop(obj_field_addr<oop>(offset));
286 }
287 inline void oopDesc::obj_field_put(int offset, oop value) {
288 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
289 oop_store(obj_field_addr<oop>(offset), value);
290 }
291
292 inline Metadata* oopDesc::metadata_field(int offset) const {
293 return *metadata_field_addr(offset);
294 }
295
296 inline void oopDesc::metadata_field_put(int offset, Metadata* value) {
297 *metadata_field_addr(offset) = value;
298 }
299
300 inline void oopDesc::obj_field_put_raw(int offset, oop value) {
301 UseCompressedOops ?
302 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
303 encode_store_heap_oop(obj_field_addr<oop>(offset), value);
304 }
305 inline void oopDesc::obj_field_put_volatile(int offset, oop value) {
306 OrderAccess::release();
307 obj_field_put(offset, value);
308 OrderAccess::fence();
309 }
310
311 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); }
312 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; }
313
314 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); }
315 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (jint) contents; }
316
317 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); }
318 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; }
319
320 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); }
321 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; }
322
323 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); }
324 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;}
325
326 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); }
327 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; }
328
329 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); }
330 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; }
331
332 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); }
333 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
334
335 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); }
336 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
337
338 inline oop oopDesc::obj_field_acquire(int offset) const {
339 return UseCompressedOops ?
340 decode_heap_oop((narrowOop)
341 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
342 : decode_heap_oop((oop)
343 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
344 }
345 inline void oopDesc::release_obj_field_put(int offset, oop value) {
346 UseCompressedOops ?
347 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
348 oop_store((volatile oop*) obj_field_addr<oop>(offset), value);
349 }
350
351 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); }
352 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); }
353
354 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); }
355 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), contents); }
356
357 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); }
358 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); }
359
360 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); }
361 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); }
362
363 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
364 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); }
365
366 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); }
367 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); }
368
369 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); }
370 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); }
371
372 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); }
373 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
374
375 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
376 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
377
378 inline int oopDesc::size_given_klass(Klass* klass) {
379 int lh = klass->layout_helper();
380 int s;
381
382 // lh is now a value computed at class initialization that may hint
383 // at the size. For instances, this is positive and equal to the
384 // size. For arrays, this is negative and provides log2 of the
385 // array element size. For other oops, it is zero and thus requires
386 // a virtual call.
387 //
388 // We go to all this trouble because the size computation is at the
389 // heart of phase 2 of mark-compaction, and called for every object,
390 // alive or dead. So the speed here is equal in importance to the
391 // speed of allocation.
392
393 if (lh > Klass::_lh_neutral_value) {
394 if (!Klass::layout_helper_needs_slow_path(lh)) {
395 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
396 } else {
397 s = klass->oop_size(this);
398 }
399 } else if (lh <= Klass::_lh_neutral_value) {
400 // The most common case is instances; fall through if so.
401 if (lh < Klass::_lh_neutral_value) {
402 // Second most common case is arrays. We have to fetch the
403 // length of the array, shift (multiply) it appropriately,
404 // up to wordSize, add the header, and align to object size.
405 size_t size_in_bytes;
406 #ifdef _M_IA64
407 // The Windows Itanium Aug 2002 SDK hoists this load above
408 // the check for s < 0. An oop at the end of the heap will
409 // cause an access violation if this load is performed on a non
410 // array oop. Making the reference volatile prohibits this.
411 // (%%% please explain by what magic the length is actually fetched!)
412 volatile int *array_length;
413 array_length = (volatile int *)( (intptr_t)this +
414 arrayOopDesc::length_offset_in_bytes() );
415 assert(array_length > 0, "Integer arithmetic problem somewhere");
416 // Put into size_t to avoid overflow.
417 size_in_bytes = (size_t) array_length;
418 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
419 #else
420 size_t array_length = (size_t) ((arrayOop)this)->length();
421 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
422 #endif
423 size_in_bytes += Klass::layout_helper_header_size(lh);
424
425 // This code could be simplified, but by keeping array_header_in_bytes
426 // in units of bytes and doing it this way we can round up just once,
427 // skipping the intermediate round to HeapWordSize. Cast the result
428 // of round_to to size_t to guarantee unsigned division == right shift.
429 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
430 HeapWordSize);
431
432 // ParNew (used by CMS), UseParallelGC and UseG1GC can change the length field
433 // of an "old copy" of an object array in the young gen so it indicates
434 // the grey portion of an already copied array. This will cause the first
435 // disjunct below to fail if the two comparands are computed across such
436 // a concurrent change.
437 // ParNew also runs with promotion labs (which look like int
438 // filler arrays) which are subject to changing their declared size
439 // when finally retiring a PLAB; this also can cause the first disjunct
440 // to fail for another worker thread that is concurrently walking the block
441 // offset table. Both these invariant failures are benign for their
442 // current uses; we relax the assertion checking to cover these two cases below:
443 // is_objArray() && is_forwarded() // covers first scenario above
444 // || is_typeArray() // covers second scenario above
445 // If and when UseParallelGC uses the same obj array oop stealing/chunking
446 // technique, we will need to suitably modify the assertion.
447 assert((s == klass->oop_size(this)) ||
448 (Universe::heap()->is_gc_active() &&
449 ((is_typeArray() && UseConcMarkSweepGC) ||
450 (is_objArray() && is_forwarded() && (UseConcMarkSweepGC || UseParallelGC || UseG1GC)))),
451 "wrong array object size");
452 } else {
453 // Must be zero, so bite the bullet and take the virtual call.
454 s = klass->oop_size(this);
455 }
456 }
457
458 assert(s % MinObjAlignment == 0, "alignment check");
459 assert(s > 0, "Bad size calculated");
460 return s;
461 }
462
463
464 inline int oopDesc::size() {
465 return size_given_klass(klass());
466 }
467
468 inline void update_barrier_set(void* p, oop v, bool release = false) {
469 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
470 oopDesc::bs()->write_ref_field(p, v, release);
471 }
472
473 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
474 oopDesc::bs()->write_ref_field_pre(p, v);
475 }
476
477 template <class T> inline void oop_store(T* p, oop v) {
478 if (always_do_update_barrier) {
479 oop_store((volatile T*)p, v);
480 } else {
481 update_barrier_set_pre(p, v);
482 oopDesc::encode_store_heap_oop(p, v);
483 // always_do_update_barrier == false =>
484 // Either we are at a safepoint (in GC) or CMS is not used. In both
485 // cases it's unnecessary to mark the card as dirty with release sematics.
486 update_barrier_set((void*)p, v, false /* release */); // cast away type
487 }
488 }
489
490 template <class T> inline void oop_store(volatile T* p, oop v) {
491 update_barrier_set_pre((T*)p, v); // cast away volatile
492 // Used by release_obj_field_put, so use release_store_ptr.
493 oopDesc::release_encode_store_heap_oop(p, v);
494 // When using CMS we must mark the card corresponding to p as dirty
495 // with release sematics to prevent that CMS sees the dirty card but
496 // not the new value v at p due to reordering of the two
497 // stores. Note that CMS has a concurrent precleaning phase, where
498 // it reads the card table while the Java threads are running.
499 update_barrier_set((void*)p, v, true /* release */); // cast away type
500 }
501
502 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
503 // (without having to remember the function name this calls).
504 inline void oop_store_raw(HeapWord* addr, oop value) {
505 if (UseCompressedOops) {
506 oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
507 } else {
508 oopDesc::encode_store_heap_oop((oop*)addr, value);
509 }
510 }
511
512 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
513 volatile HeapWord *dest,
514 oop compare_value,
515 bool prebarrier) {
516 if (UseCompressedOops) {
517 if (prebarrier) {
518 update_barrier_set_pre((narrowOop*)dest, exchange_value);
519 }
520 // encode exchange and compare value from oop to T
521 narrowOop val = encode_heap_oop(exchange_value);
522 narrowOop cmp = encode_heap_oop(compare_value);
523
524 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
525 // decode old from T to oop
526 return decode_heap_oop(old);
527 } else {
528 if (prebarrier) {
529 update_barrier_set_pre((oop*)dest, exchange_value);
530 }
531 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
532 }
533 }
534
535 // Used only for markSweep, scavenging
536 inline bool oopDesc::is_gc_marked() const {
537 return mark()->is_marked();
538 }
539
540 inline bool oopDesc::is_locked() const {
541 return mark()->is_locked();
542 }
543
544 inline bool oopDesc::is_unlocked() const {
545 return mark()->is_unlocked();
546 }
547
548 inline bool oopDesc::has_bias_pattern() const {
549 return mark()->has_bias_pattern();
550 }
551
552
553 // used only for asserts
554 inline bool oopDesc::is_oop(bool ignore_mark_word) const {
555 oop obj = (oop) this;
556 if (!check_obj_alignment(obj)) return false;
557 if (!Universe::heap()->is_in_reserved(obj)) return false;
558 // obj is aligned and accessible in heap
559 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false;
560
561 // Header verification: the mark is typically non-NULL. If we're
562 // at a safepoint, it must not be null.
563 // Outside of a safepoint, the header could be changing (for example,
564 // another thread could be inflating a lock on this object).
565 if (ignore_mark_word) {
566 return true;
567 }
568 if (mark() != NULL) {
569 return true;
570 }
571 return !SafepointSynchronize::is_at_safepoint();
572 }
573
574
575 // used only for asserts
576 inline 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 inline 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 inline bool oopDesc::is_scavengable() const {
589 return Universe::heap()->is_scavengable(this);
590 }
591
592 // Used by scavengers
593 inline bool oopDesc::is_forwarded() const {
594 // The extra heap check is needed since the obj might be locked, in which case the
595 // mark would point to a stack location and have the sentinel bit cleared
596 return mark()->is_marked();
597 }
598
599 // Used by scavengers
600 inline void oopDesc::forward_to(oop p) {
601 assert(check_obj_alignment(p),
602 "forwarding to something not aligned");
603 assert(Universe::heap()->is_in_reserved(p),
604 "forwarding to something not in heap");
605 markOop m = markOopDesc::encode_pointer_as_mark(p);
606 assert(m->decode_pointer() == p, "encoding must be reversable");
607 set_mark(m);
608 }
609
610 // Used by parallel scavengers
611 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
612 assert(check_obj_alignment(p),
613 "forwarding to something not aligned");
614 assert(Universe::heap()->is_in_reserved(p),
615 "forwarding to something not in heap");
616 markOop m = markOopDesc::encode_pointer_as_mark(p);
617 assert(m->decode_pointer() == p, "encoding must be reversable");
618 return cas_set_mark(m, compare) == compare;
619 }
620
621 #if INCLUDE_ALL_GCS
622 inline oop oopDesc::forward_to_atomic(oop p) {
623 markOop oldMark = mark();
624 markOop forwardPtrMark = markOopDesc::encode_pointer_as_mark(p);
625 markOop curMark;
626
627 assert(forwardPtrMark->decode_pointer() == p, "encoding must be reversable");
628 assert(sizeof(markOop) == sizeof(intptr_t), "CAS below requires this.");
629
630 while (!oldMark->is_marked()) {
631 curMark = (markOop)Atomic::cmpxchg_ptr(forwardPtrMark, &_mark, oldMark);
632 assert(is_forwarded(), "object should have been forwarded");
633 if (curMark == oldMark) {
634 return NULL;
635 }
636 // If the CAS was unsuccessful then curMark->is_marked()
637 // should return true as another thread has CAS'd in another
638 // forwarding pointer.
639 oldMark = curMark;
640 }
641 return forwardee();
642 }
643 #endif
644
645 // Note that the forwardee is not the same thing as the displaced_mark.
646 // The forwardee is used when copying during scavenge and mark-sweep.
647 // It does need to clear the low two locking- and GC-related bits.
648 inline oop oopDesc::forwardee() const {
649 return (oop) mark()->decode_pointer();
650 }
651
652 inline bool oopDesc::has_displaced_mark() const {
653 return mark()->has_displaced_mark_helper();
654 }
655
656 inline markOop oopDesc::displaced_mark() const {
657 return mark()->displaced_mark_helper();
658 }
659
660 inline void oopDesc::set_displaced_mark(markOop m) {
661 mark()->set_displaced_mark_helper(m);
662 }
663
664 // The following method needs to be MT safe.
665 inline uint oopDesc::age() const {
666 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
667 if (has_displaced_mark()) {
668 return displaced_mark()->age();
669 } else {
670 return mark()->age();
671 }
672 }
673
674 inline void oopDesc::incr_age() {
675 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
676 if (has_displaced_mark()) {
677 set_displaced_mark(displaced_mark()->incr_age());
678 } else {
679 set_mark(mark()->incr_age());
680 }
681 }
682
683
684 inline intptr_t oopDesc::identity_hash() {
685 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
686 // Note: The mark must be read into local variable to avoid concurrent updates.
687 markOop mrk = mark();
688 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
689 return mrk->hash();
690 } else if (mrk->is_marked()) {
691 return mrk->hash();
692 } else {
693 return slow_identity_hash();
694 }
695 }
696
697 inline void oopDesc::ms_follow_contents() {
698 klass()->oop_ms_follow_contents(this);
699 }
700
701 inline int oopDesc::ms_adjust_pointers() {
702 debug_only(int check_size = size());
703 int s = klass()->oop_ms_adjust_pointers(this);
704 assert(s == check_size, "should be the same");
705 return s;
706 }
707
708 #if INCLUDE_ALL_GCS
709 inline void oopDesc::pc_follow_contents(ParCompactionManager* cm) {
710 klass()->oop_pc_follow_contents(this, cm);
711 }
712
713 inline void oopDesc::pc_update_contents() {
714 Klass* k = klass();
715 if (!k->oop_is_typeArray()) {
716 // It might contain oops beyond the header, so take the virtual call.
717 k->oop_pc_update_pointers(this);
718 }
719 // Else skip it. The TypeArrayKlass in the header never needs scavenging.
720 }
721
722 inline void oopDesc::ps_push_contents(PSPromotionManager* pm) {
723 Klass* k = klass();
724 if (!k->oop_is_typeArray()) {
725 // It might contain oops beyond the header, so take the virtual call.
726 k->oop_ps_push_contents(this, pm);
727 }
728 // Else skip it. The TypeArrayKlass in the header never needs scavenging.
729 }
730 #endif
731
732 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
733 \
734 inline int oopDesc::oop_iterate(OopClosureType* blk) { \
735 return klass()->oop_oop_iterate##nv_suffix(this, blk); \
736 } \
737 \
738 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
739 return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \
740 }
741
742
743 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) {
744 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
745 // the do_oop calls, but turns off all other features in ExtendedOopClosure.
746 NoHeaderExtendedOopClosure cl(blk);
747 return oop_iterate(&cl);
748 }
749
750 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
751 NoHeaderExtendedOopClosure cl(blk);
752 return oop_iterate(&cl, mr);
753 }
754
755 #if INCLUDE_ALL_GCS
756 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
757 \
758 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
759 return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
760 }
761 #else
762 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)
763 #endif
764
765 #define ALL_OOPDESC_OOP_ITERATE(OopClosureType, nv_suffix) \
766 OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
767 OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)
768
769 ALL_OOP_OOP_ITERATE_CLOSURES_1(ALL_OOPDESC_OOP_ITERATE)
770 ALL_OOP_OOP_ITERATE_CLOSURES_2(ALL_OOPDESC_OOP_ITERATE)
771
772 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP