1 /*
2 * Copyright (c) 1997, 2014, 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_implementation/shared/ageTable.hpp"
29 #include "gc_implementation/shared/markSweep.inline.hpp"
30 #include "gc_interface/collectedHeap.inline.hpp"
31 #include "memory/barrierSet.inline.hpp"
32 #include "memory/cardTableModRefBS.hpp"
33 #include "memory/genCollectedHeap.hpp"
34 #include "memory/generation.hpp"
35 #include "memory/specialized_oop_closures.hpp"
36 #include "oops/arrayKlass.hpp"
37 #include "oops/arrayOop.hpp"
38 #include "oops/klass.inline.hpp"
39 #include "oops/markOop.inline.hpp"
40 #include "oops/oop.hpp"
41 #include "runtime/atomic.inline.hpp"
42 #include "runtime/orderAccess.inline.hpp"
43 #include "runtime/os.hpp"
44 #include "utilities/macros.hpp"
45
46 // Implementation of all inlined member functions defined in oop.hpp
47 // We need a separate file to avoid circular references
48
49 inline void oopDesc::release_set_mark(markOop m) {
50 OrderAccess::release_store_ptr(&_mark, m);
51 }
52
53 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
54 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
55 }
56
57 inline Klass* oopDesc::klass() const {
58 if (UseCompressedClassPointers) {
59 return Klass::decode_klass_not_null(_metadata._compressed_klass);
60 } else {
61 return _metadata._klass;
62 }
63 }
64
65 inline Klass* oopDesc::klass_or_null() const volatile {
66 // can be NULL in CMS
67 if (UseCompressedClassPointers) {
68 return Klass::decode_klass(_metadata._compressed_klass);
69 } else {
70 return _metadata._klass;
71 }
72 }
73
74 inline Klass** oopDesc::klass_addr() {
75 // Only used internally and with CMS and will not work with
76 // UseCompressedOops
77 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers");
78 return (Klass**) &_metadata._klass;
79 }
80
81 inline narrowKlass* oopDesc::compressed_klass_addr() {
82 assert(UseCompressedClassPointers, "only called by compressed klass pointers");
83 return &_metadata._compressed_klass;
84 }
85
86 inline void oopDesc::set_klass(Klass* k) {
87 // since klasses are promoted no store check is needed
88 assert(Universe::is_bootstrapping() || k != NULL, "must be a real Klass*");
89 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass*");
90 if (UseCompressedClassPointers) {
91 *compressed_klass_addr() = Klass::encode_klass_not_null(k);
92 } else {
93 *klass_addr() = k;
94 }
95 }
96
97 inline int oopDesc::klass_gap() const {
98 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
99 }
100
101 inline void oopDesc::set_klass_gap(int v) {
102 if (UseCompressedClassPointers) {
103 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
104 }
105 }
106
107 inline void oopDesc::set_klass_to_list_ptr(oop k) {
108 // This is only to be used during GC, for from-space objects, so no
109 // barrier is needed.
110 if (UseCompressedClassPointers) {
111 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling)
112 } else {
113 _metadata._klass = (Klass*)(address)k;
114 }
115 }
116
117 inline oop oopDesc::list_ptr_from_klass() {
118 // This is only to be used during GC, for from-space objects.
119 if (UseCompressedClassPointers) {
120 return decode_heap_oop((narrowOop)_metadata._compressed_klass);
121 } else {
122 // Special case for GC
123 return (oop)(address)_metadata._klass;
124 }
125 }
126
127 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); }
128
129 inline bool oopDesc::is_a(Klass* k) const { return klass()->is_subtype_of(k); }
130
131 inline bool oopDesc::is_instance() const { return klass()->oop_is_instance(); }
132 inline bool oopDesc::is_instanceClassLoader() const { return klass()->oop_is_instanceClassLoader(); }
133 inline bool oopDesc::is_instanceMirror() const { return klass()->oop_is_instanceMirror(); }
134 inline bool oopDesc::is_instanceRef() const { return klass()->oop_is_instanceRef(); }
135 inline bool oopDesc::is_array() const { return klass()->oop_is_array(); }
136 inline bool oopDesc::is_objArray() const { return klass()->oop_is_objArray(); }
137 inline bool oopDesc::is_typeArray() const { return klass()->oop_is_typeArray(); }
138
139 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; }
140
141 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
142 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
143 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); }
144 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); }
145 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); }
146 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); }
147 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); }
148 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); }
149 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); }
150 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
151 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
152
153
154 // Functions for getting and setting oops within instance objects.
155 // If the oops are compressed, the type passed to these overloaded functions
156 // is narrowOop. All functions are overloaded so they can be called by
157 // template functions without conditionals (the compiler instantiates via
158 // the right type and inlines the appopriate code).
159
160 inline bool oopDesc::is_null(oop obj) { return obj == NULL; }
161 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }
162
163 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
164 // offset from the heap base. Saving the check for null can save instructions
165 // in inner GC loops so these are separated.
166
167 inline bool check_obj_alignment(oop obj) {
168 return cast_from_oop<intptr_t>(obj) % MinObjAlignmentInBytes == 0;
169 }
170
171 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
172 assert(!is_null(v), "oop value can never be zero");
173 assert(check_obj_alignment(v), "Address not aligned");
174 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
175 address base = Universe::narrow_oop_base();
176 int shift = Universe::narrow_oop_shift();
177 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
178 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
179 uint64_t result = pd >> shift;
180 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
181 assert(decode_heap_oop(result) == v, "reversibility");
182 return (narrowOop)result;
183 }
184
185 inline narrowOop oopDesc::encode_heap_oop(oop v) {
186 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
187 }
188
189 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
190 assert(!is_null(v), "narrow oop value can never be zero");
191 address base = Universe::narrow_oop_base();
192 int shift = Universe::narrow_oop_shift();
193 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
194 assert(check_obj_alignment(result), err_msg("address not aligned: " INTPTR_FORMAT, p2i((void*) result)));
195 return result;
196 }
197
198 inline oop oopDesc::decode_heap_oop(narrowOop v) {
199 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
200 }
201
202 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
203 inline oop oopDesc::decode_heap_oop(oop v) { return v; }
204
205 // Load an oop out of the Java heap as is without decoding.
206 // Called by GC to check for null before decoding.
207 inline oop oopDesc::load_heap_oop(oop* p) { return *p; }
208 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
209
210 // Load and decode an oop out of the Java heap into a wide oop.
211 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
212 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
213 return decode_heap_oop_not_null(*p);
214 }
215
216 // Load and decode an oop out of the heap accepting null
217 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
218 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
219 return decode_heap_oop(*p);
220 }
221
222 // Store already encoded heap oop into the heap.
223 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; }
224 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
225
226 // Encode and store a heap oop.
227 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
228 *p = encode_heap_oop_not_null(v);
229 }
230 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
231
232 // Encode and store a heap oop allowing for null.
233 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
234 *p = encode_heap_oop(v);
235 }
236 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
237
238 // Store heap oop as is for volatile fields.
239 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
240 OrderAccess::release_store_ptr(p, v);
241 }
242 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
243 narrowOop v) {
244 OrderAccess::release_store(p, v);
245 }
246
247 inline void oopDesc::release_encode_store_heap_oop_not_null(
248 volatile narrowOop* p, oop v) {
249 // heap oop is not pointer sized.
250 OrderAccess::release_store(p, encode_heap_oop_not_null(v));
251 }
252
253 inline void oopDesc::release_encode_store_heap_oop_not_null(
254 volatile oop* p, oop v) {
255 OrderAccess::release_store_ptr(p, v);
256 }
257
258 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
259 oop v) {
260 OrderAccess::release_store_ptr(p, v);
261 }
262 inline void oopDesc::release_encode_store_heap_oop(
263 volatile narrowOop* p, oop v) {
264 OrderAccess::release_store(p, encode_heap_oop(v));
265 }
266
267
268 // These functions are only used to exchange oop fields in instances,
269 // not headers.
270 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
271 if (UseCompressedOops) {
272 // encode exchange value from oop to T
273 narrowOop val = encode_heap_oop(exchange_value);
274 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
275 // decode old from T to oop
276 return decode_heap_oop(old);
277 } else {
278 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
279 }
280 }
281
282 // In order to put or get a field out of an instance, must first check
283 // if the field has been compressed and uncompress it.
284 inline oop oopDesc::obj_field(int offset) const {
285 return UseCompressedOops ?
286 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
287 load_decode_heap_oop(obj_field_addr<oop>(offset));
288 }
289 inline volatile oop oopDesc::obj_field_volatile(int offset) const {
290 volatile oop value = obj_field(offset);
291 OrderAccess::acquire();
292 return value;
293 }
294 inline void oopDesc::obj_field_put(int offset, oop value) {
295 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
296 oop_store(obj_field_addr<oop>(offset), value);
297 }
298
299 inline Metadata* oopDesc::metadata_field(int offset) const {
300 return *metadata_field_addr(offset);
301 }
302
303 inline void oopDesc::metadata_field_put(int offset, Metadata* value) {
304 *metadata_field_addr(offset) = value;
305 }
306
307 inline void oopDesc::obj_field_put_raw(int offset, oop value) {
308 UseCompressedOops ?
309 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
310 encode_store_heap_oop(obj_field_addr<oop>(offset), value);
311 }
312 inline void oopDesc::obj_field_put_volatile(int offset, oop value) {
313 OrderAccess::release();
314 obj_field_put(offset, value);
315 OrderAccess::fence();
316 }
317
318 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); }
319 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; }
320
321 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); }
322 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (jint) contents; }
323
324 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); }
325 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; }
326
327 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); }
328 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; }
329
330 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); }
331 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;}
332
333 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); }
334 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; }
335
336 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); }
337 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; }
338
339 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); }
340 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
341
342 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); }
343 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
344
345 inline oop oopDesc::obj_field_acquire(int offset) const {
346 return UseCompressedOops ?
347 decode_heap_oop((narrowOop)
348 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
349 : decode_heap_oop((oop)
350 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
351 }
352 inline void oopDesc::release_obj_field_put(int offset, oop value) {
353 UseCompressedOops ?
354 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
355 oop_store((volatile oop*) obj_field_addr<oop>(offset), value);
356 }
357
358 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); }
359 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); }
360
361 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); }
362 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), contents); }
363
364 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); }
365 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); }
366
367 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); }
368 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); }
369
370 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
371 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); }
372
373 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); }
374 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); }
375
376 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); }
377 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); }
378
379 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); }
380 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
381
382 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
383 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
384
385 inline int oopDesc::size_given_klass(Klass* klass) {
386 int lh = klass->layout_helper();
387 int s;
388
389 // lh is now a value computed at class initialization that may hint
390 // at the size. For instances, this is positive and equal to the
391 // size. For arrays, this is negative and provides log2 of the
392 // array element size. For other oops, it is zero and thus requires
393 // a virtual call.
394 //
395 // We go to all this trouble because the size computation is at the
396 // heart of phase 2 of mark-compaction, and called for every object,
397 // alive or dead. So the speed here is equal in importance to the
398 // speed of allocation.
399
400 if (lh > Klass::_lh_neutral_value) {
401 if (!Klass::layout_helper_needs_slow_path(lh)) {
402 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
403 } else {
404 s = klass->oop_size(this);
405 }
406 } else if (lh <= Klass::_lh_neutral_value) {
407 // The most common case is instances; fall through if so.
408 if (lh < Klass::_lh_neutral_value) {
409 // Second most common case is arrays. We have to fetch the
410 // length of the array, shift (multiply) it appropriately,
411 // up to wordSize, add the header, and align to object size.
412 size_t size_in_bytes;
413 #ifdef _M_IA64
414 // The Windows Itanium Aug 2002 SDK hoists this load above
415 // the check for s < 0. An oop at the end of the heap will
416 // cause an access violation if this load is performed on a non
417 // array oop. Making the reference volatile prohibits this.
418 // (%%% please explain by what magic the length is actually fetched!)
419 volatile int *array_length;
420 array_length = (volatile int *)( (intptr_t)this +
421 arrayOopDesc::length_offset_in_bytes() );
422 assert(array_length > 0, "Integer arithmetic problem somewhere");
423 // Put into size_t to avoid overflow.
424 size_in_bytes = (size_t) array_length;
425 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
426 #else
427 size_t array_length = (size_t) ((arrayOop)this)->length();
428 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
429 #endif
430 size_in_bytes += Klass::layout_helper_header_size(lh);
431
432 // This code could be simplified, but by keeping array_header_in_bytes
433 // in units of bytes and doing it this way we can round up just once,
434 // skipping the intermediate round to HeapWordSize. Cast the result
435 // of round_to to size_t to guarantee unsigned division == right shift.
436 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
437 HeapWordSize);
438
439 // ParNew (used by CMS), UseParallelGC and UseG1GC can change the length field
440 // of an "old copy" of an object array in the young gen so it indicates
441 // the grey portion of an already copied array. This will cause the first
442 // disjunct below to fail if the two comparands are computed across such
443 // a concurrent change.
444 // ParNew also runs with promotion labs (which look like int
445 // filler arrays) which are subject to changing their declared size
446 // when finally retiring a PLAB; this also can cause the first disjunct
447 // to fail for another worker thread that is concurrently walking the block
448 // offset table. Both these invariant failures are benign for their
449 // current uses; we relax the assertion checking to cover these two cases below:
450 // is_objArray() && is_forwarded() // covers first scenario above
451 // || is_typeArray() // covers second scenario above
452 // If and when UseParallelGC uses the same obj array oop stealing/chunking
453 // technique, we will need to suitably modify the assertion.
454 assert((s == klass->oop_size(this)) ||
455 (Universe::heap()->is_gc_active() &&
456 ((is_typeArray() && UseConcMarkSweepGC) ||
457 (is_objArray() && is_forwarded() && (UseConcMarkSweepGC || UseParallelGC || UseG1GC)))),
458 "wrong array object size");
459 } else {
460 // Must be zero, so bite the bullet and take the virtual call.
461 s = klass->oop_size(this);
462 }
463 }
464
465 assert(s % MinObjAlignment == 0, "alignment check");
466 assert(s > 0, "Bad size calculated");
467 return s;
468 }
469
470
471 inline int oopDesc::size() {
472 return size_given_klass(klass());
473 }
474
475 inline void update_barrier_set(void* p, oop v, bool release = false) {
476 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
477 oopDesc::bs()->write_ref_field(p, v, release);
478 }
479
480 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
481 oopDesc::bs()->write_ref_field_pre(p, v);
482 }
483
484 template <class T> inline void oop_store(T* p, oop v) {
485 if (always_do_update_barrier) {
486 oop_store((volatile T*)p, v);
487 } else {
488 update_barrier_set_pre(p, v);
489 oopDesc::encode_store_heap_oop(p, v);
490 // always_do_update_barrier == false =>
491 // Either we are at a safepoint (in GC) or CMS is not used. In both
492 // cases it's unnecessary to mark the card as dirty with release sematics.
493 update_barrier_set((void*)p, v, false /* release */); // cast away type
494 }
495 }
496
497 template <class T> inline void oop_store(volatile T* p, oop v) {
498 update_barrier_set_pre((T*)p, v); // cast away volatile
499 // Used by release_obj_field_put, so use release_store_ptr.
500 oopDesc::release_encode_store_heap_oop(p, v);
501 // When using CMS we must mark the card corresponding to p as dirty
502 // with release sematics to prevent that CMS sees the dirty card but
503 // not the new value v at p due to reordering of the two
504 // stores. Note that CMS has a concurrent precleaning phase, where
505 // it reads the card table while the Java threads are running.
506 update_barrier_set((void*)p, v, true /* release */); // cast away type
507 }
508
509 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
510 // (without having to remember the function name this calls).
511 inline void oop_store_raw(HeapWord* addr, oop value) {
512 if (UseCompressedOops) {
513 oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
514 } else {
515 oopDesc::encode_store_heap_oop((oop*)addr, value);
516 }
517 }
518
519 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
520 volatile HeapWord *dest,
521 oop compare_value,
522 bool prebarrier) {
523 if (UseCompressedOops) {
524 if (prebarrier) {
525 update_barrier_set_pre((narrowOop*)dest, exchange_value);
526 }
527 // encode exchange and compare value from oop to T
528 narrowOop val = encode_heap_oop(exchange_value);
529 narrowOop cmp = encode_heap_oop(compare_value);
530
531 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
532 // decode old from T to oop
533 return decode_heap_oop(old);
534 } else {
535 if (prebarrier) {
536 update_barrier_set_pre((oop*)dest, exchange_value);
537 }
538 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
539 }
540 }
541
542 // Used only for markSweep, scavenging
543 inline bool oopDesc::is_gc_marked() const {
544 return mark()->is_marked();
545 }
546
547 inline bool oopDesc::is_locked() const {
548 return mark()->is_locked();
549 }
550
551 inline bool oopDesc::is_unlocked() const {
552 return mark()->is_unlocked();
553 }
554
555 inline bool oopDesc::has_bias_pattern() const {
556 return mark()->has_bias_pattern();
557 }
558
559
560 // used only for asserts
561 inline bool oopDesc::is_oop(bool ignore_mark_word) const {
562 oop obj = (oop) this;
563 if (!check_obj_alignment(obj)) return false;
564 if (!Universe::heap()->is_in_reserved(obj)) return false;
565 // obj is aligned and accessible in heap
566 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false;
567
568 // Header verification: the mark is typically non-NULL. If we're
569 // at a safepoint, it must not be null.
570 // Outside of a safepoint, the header could be changing (for example,
571 // another thread could be inflating a lock on this object).
572 if (ignore_mark_word) {
573 return true;
574 }
575 if (mark() != NULL) {
576 return true;
577 }
578 return !SafepointSynchronize::is_at_safepoint();
579 }
580
581
582 // used only for asserts
583 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
584 return this == NULL ? true : is_oop(ignore_mark_word);
585 }
586
587 #ifndef PRODUCT
588 // used only for asserts
589 inline bool oopDesc::is_unlocked_oop() const {
590 if (!Universe::heap()->is_in_reserved(this)) return false;
591 return mark()->is_unlocked();
592 }
593 #endif // PRODUCT
594
595 inline void oopDesc::follow_contents(void) {
596 assert (is_gc_marked(), "should be marked");
597 klass()->oop_follow_contents(this);
598 }
599
600 inline bool oopDesc::is_scavengable() const {
601 return Universe::heap()->is_scavengable(this);
602 }
603
604 // Used by scavengers
605 inline bool oopDesc::is_forwarded() const {
606 // The extra heap check is needed since the obj might be locked, in which case the
607 // mark would point to a stack location and have the sentinel bit cleared
608 return mark()->is_marked();
609 }
610
611 // Used by scavengers
612 inline void oopDesc::forward_to(oop p) {
613 assert(check_obj_alignment(p),
614 "forwarding to something not aligned");
615 assert(Universe::heap()->is_in_reserved(p),
616 "forwarding to something not in heap");
617 markOop m = markOopDesc::encode_pointer_as_mark(p);
618 assert(m->decode_pointer() == p, "encoding must be reversable");
619 set_mark(m);
620 }
621
622 // Used by parallel scavengers
623 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
624 assert(check_obj_alignment(p),
625 "forwarding to something not aligned");
626 assert(Universe::heap()->is_in_reserved(p),
627 "forwarding to something not in heap");
628 markOop m = markOopDesc::encode_pointer_as_mark(p);
629 assert(m->decode_pointer() == p, "encoding must be reversable");
630 return cas_set_mark(m, compare) == compare;
631 }
632
633 // Note that the forwardee is not the same thing as the displaced_mark.
634 // The forwardee is used when copying during scavenge and mark-sweep.
635 // It does need to clear the low two locking- and GC-related bits.
636 inline oop oopDesc::forwardee() const {
637 return (oop) mark()->decode_pointer();
638 }
639
640 inline bool oopDesc::has_displaced_mark() const {
641 return mark()->has_displaced_mark_helper();
642 }
643
644 inline markOop oopDesc::displaced_mark() const {
645 return mark()->displaced_mark_helper();
646 }
647
648 inline void oopDesc::set_displaced_mark(markOop m) {
649 mark()->set_displaced_mark_helper(m);
650 }
651
652 // The following method needs to be MT safe.
653 inline uint oopDesc::age() const {
654 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
655 if (has_displaced_mark()) {
656 return displaced_mark()->age();
657 } else {
658 return mark()->age();
659 }
660 }
661
662 inline void oopDesc::incr_age() {
663 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
664 if (has_displaced_mark()) {
665 set_displaced_mark(displaced_mark()->incr_age());
666 } else {
667 set_mark(mark()->incr_age());
668 }
669 }
670
671
672 inline intptr_t oopDesc::identity_hash() {
673 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
674 // Note: The mark must be read into local variable to avoid concurrent updates.
675 markOop mrk = mark();
676 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
677 return mrk->hash();
678 } else if (mrk->is_marked()) {
679 return mrk->hash();
680 } else {
681 return slow_identity_hash();
682 }
683 }
684
685 inline int oopDesc::adjust_pointers() {
686 debug_only(int check_size = size());
687 int s = klass()->oop_adjust_pointers(this);
688 assert(s == check_size, "should be the same");
689 return s;
690 }
691
692 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
693 \
694 inline int oopDesc::oop_iterate(OopClosureType* blk) { \
695 SpecializationStats::record_call(); \
696 return klass()->oop_oop_iterate##nv_suffix(this, blk); \
697 } \
698 \
699 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
700 SpecializationStats::record_call(); \
701 return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \
702 }
703
704
705 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) {
706 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
707 // the do_oop calls, but turns off all other features in ExtendedOopClosure.
708 NoHeaderExtendedOopClosure cl(blk);
709 return oop_iterate(&cl);
710 }
711
712 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
713 NoHeaderExtendedOopClosure cl(blk);
714 return oop_iterate(&cl, mr);
715 }
716
717 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN)
718 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN)
719
720 #if INCLUDE_ALL_GCS
721 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
722 \
723 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
724 SpecializationStats::record_call(); \
725 return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
726 }
727
728 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN)
729 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN)
730 #endif // INCLUDE_ALL_GCS
731
732 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP