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/serial/markSweep.inline.hpp"
29 #include "gc/shared/ageTable.hpp"
30 #include "gc/shared/barrierSet.inline.hpp"
31 #include "gc/shared/cardTableModRefBS.hpp"
32 #include "gc/shared/collectedHeap.inline.hpp"
33 #include "gc/shared/genCollectedHeap.hpp"
34 #include "gc/shared/generation.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.inline.hpp"
41 #include "runtime/orderAccess.inline.hpp"
42 #include "runtime/os.hpp"
43 #include "utilities/macros.hpp"
44
45 // Implementation of all inlined member functions defined in oop.hpp
46 // We need a separate file to avoid circular references
47
48 inline void oopDesc::release_set_mark(markOop m) {
49 OrderAccess::release_store_ptr(&_mark, m);
50 }
51
52 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
53 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
54 }
55
56 inline Klass* oopDesc::klass() const {
57 if (UseCompressedClassPointers) {
58 return Klass::decode_klass_not_null(_metadata._compressed_klass);
59 } else {
60 return _metadata._klass;
61 }
62 }
63
64 inline Klass* oopDesc::klass_or_null() const volatile {
65 // can be NULL in CMS
66 if (UseCompressedClassPointers) {
67 return Klass::decode_klass(_metadata._compressed_klass);
68 } else {
69 return _metadata._klass;
70 }
71 }
72
73 inline Klass** oopDesc::klass_addr() {
74 // Only used internally and with CMS and will not work with
75 // UseCompressedOops
76 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers");
77 return (Klass**) &_metadata._klass;
78 }
79
80 inline narrowKlass* oopDesc::compressed_klass_addr() {
81 assert(UseCompressedClassPointers, "only called by compressed klass pointers");
82 return &_metadata._compressed_klass;
83 }
84
85 inline void oopDesc::set_klass(Klass* k) {
86 // since klasses are promoted no store check is needed
87 assert(Universe::is_bootstrapping() || k != NULL, "must be a real Klass*");
88 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass*");
89 if (UseCompressedClassPointers) {
90 *compressed_klass_addr() = Klass::encode_klass_not_null(k);
91 } else {
92 *klass_addr() = k;
93 }
94 }
95
96 inline int oopDesc::klass_gap() const {
97 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
98 }
99
100 inline void oopDesc::set_klass_gap(int v) {
101 if (UseCompressedClassPointers) {
102 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
103 }
104 }
105
106 inline void oopDesc::set_klass_to_list_ptr(oop k) {
107 // This is only to be used during GC, for from-space objects, so no
108 // barrier is needed.
109 if (UseCompressedClassPointers) {
110 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling)
111 } else {
112 _metadata._klass = (Klass*)(address)k;
113 }
114 }
115
116 inline oop oopDesc::list_ptr_from_klass() {
117 // This is only to be used during GC, for from-space objects.
118 if (UseCompressedClassPointers) {
119 return decode_heap_oop((narrowOop)_metadata._compressed_klass);
120 } else {
121 // Special case for GC
122 return (oop)(address)_metadata._klass;
123 }
124 }
125
126 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); }
127
128 inline bool oopDesc::is_a(Klass* k) const { return klass()->is_subtype_of(k); }
129
130 inline bool oopDesc::is_instance() const { return klass()->oop_is_instance(); }
131 inline bool oopDesc::is_instanceClassLoader() const { return klass()->oop_is_instanceClassLoader(); }
132 inline bool oopDesc::is_instanceMirror() const { return klass()->oop_is_instanceMirror(); }
133 inline bool oopDesc::is_instanceRef() const { return klass()->oop_is_instanceRef(); }
134 inline bool oopDesc::is_array() const { return klass()->oop_is_array(); }
135 inline bool oopDesc::is_objArray() const { return klass()->oop_is_objArray(); }
136 inline bool oopDesc::is_typeArray() const { return klass()->oop_is_typeArray(); }
137
138 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; }
139
140 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
141 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
142 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); }
143 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); }
144 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); }
145 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); }
146 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); }
147 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); }
148 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); }
149 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
150 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
151
152
153 // Functions for getting and setting oops within instance objects.
154 // If the oops are compressed, the type passed to these overloaded functions
155 // is narrowOop. All functions are overloaded so they can be called by
156 // template functions without conditionals (the compiler instantiates via
157 // the right type and inlines the appopriate code).
158
159 inline bool oopDesc::is_null(oop obj) { return obj == NULL; }
160 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }
161
162 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
163 // offset from the heap base. Saving the check for null can save instructions
164 // in inner GC loops so these are separated.
165
166 inline bool check_obj_alignment(oop obj) {
167 return cast_from_oop<intptr_t>(obj) % MinObjAlignmentInBytes == 0;
168 }
169
170 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
171 assert(!is_null(v), "oop value can never be zero");
172 assert(check_obj_alignment(v), "Address not aligned");
173 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
174 address base = Universe::narrow_oop_base();
175 int shift = Universe::narrow_oop_shift();
176 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
177 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
178 uint64_t result = pd >> shift;
179 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
180 assert(decode_heap_oop(result) == v, "reversibility");
181 return (narrowOop)result;
182 }
183
184 inline narrowOop oopDesc::encode_heap_oop(oop v) {
185 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
186 }
187
188 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
189 assert(!is_null(v), "narrow oop value can never be zero");
190 address base = Universe::narrow_oop_base();
191 int shift = Universe::narrow_oop_shift();
192 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
193 assert(check_obj_alignment(result), err_msg("address not aligned: " INTPTR_FORMAT, p2i((void*) result)));
194 return result;
195 }
196
197 inline oop oopDesc::decode_heap_oop(narrowOop v) {
198 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
199 }
200
201 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
202 inline oop oopDesc::decode_heap_oop(oop v) { return v; }
203
204 // Load an oop out of the Java heap as is without decoding.
205 // Called by GC to check for null before decoding.
206 inline oop oopDesc::load_heap_oop(oop* p) { return *p; }
207 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
208
209 // Load and decode an oop out of the Java heap into a wide oop.
210 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
211 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
212 return decode_heap_oop_not_null(*p);
213 }
214
215 // Load and decode an oop out of the heap accepting null
216 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
217 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
218 return decode_heap_oop(*p);
219 }
220
221 // Store already encoded heap oop into the heap.
222 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; }
223 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
224
225 // Encode and store a heap oop.
226 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
227 *p = encode_heap_oop_not_null(v);
228 }
229 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
230
231 // Encode and store a heap oop allowing for null.
232 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
233 *p = encode_heap_oop(v);
234 }
235 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
236
237 // Store heap oop as is for volatile fields.
238 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
239 OrderAccess::release_store_ptr(p, v);
240 }
241 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
242 narrowOop v) {
243 OrderAccess::release_store(p, v);
244 }
245
246 inline void oopDesc::release_encode_store_heap_oop_not_null(
247 volatile narrowOop* p, oop v) {
248 // heap oop is not pointer sized.
249 OrderAccess::release_store(p, encode_heap_oop_not_null(v));
250 }
251
252 inline void oopDesc::release_encode_store_heap_oop_not_null(
253 volatile oop* p, oop v) {
254 OrderAccess::release_store_ptr(p, v);
255 }
256
257 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
258 oop v) {
259 OrderAccess::release_store_ptr(p, v);
260 }
261 inline void oopDesc::release_encode_store_heap_oop(
262 volatile narrowOop* p, oop v) {
263 OrderAccess::release_store(p, encode_heap_oop(v));
264 }
265
266
267 // These functions are only used to exchange oop fields in instances,
268 // not headers.
269 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
270 if (UseCompressedOops) {
271 // encode exchange value from oop to T
272 narrowOop val = encode_heap_oop(exchange_value);
273 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
274 // decode old from T to oop
275 return decode_heap_oop(old);
276 } else {
277 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
278 }
279 }
280
281 // In order to put or get a field out of an instance, must first check
282 // if the field has been compressed and uncompress it.
283 inline oop oopDesc::obj_field(int offset) const {
284 return UseCompressedOops ?
285 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
286 load_decode_heap_oop(obj_field_addr<oop>(offset));
287 }
288 inline volatile oop oopDesc::obj_field_volatile(int offset) const {
289 volatile oop value = obj_field(offset);
290 OrderAccess::acquire();
291 return value;
292 }
293 inline void oopDesc::obj_field_put(int offset, oop value) {
294 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
295 oop_store(obj_field_addr<oop>(offset), value);
296 }
297
298 inline Metadata* oopDesc::metadata_field(int offset) const {
299 return *metadata_field_addr(offset);
300 }
301
302 inline void oopDesc::metadata_field_put(int offset, Metadata* value) {
303 *metadata_field_addr(offset) = value;
304 }
305
306 inline void oopDesc::obj_field_put_raw(int offset, oop value) {
307 UseCompressedOops ?
308 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
309 encode_store_heap_oop(obj_field_addr<oop>(offset), value);
310 }
311 inline void oopDesc::obj_field_put_volatile(int offset, oop value) {
312 OrderAccess::release();
313 obj_field_put(offset, value);
314 OrderAccess::fence();
315 }
316
317 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); }
318 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; }
319
320 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); }
321 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (jint) contents; }
322
323 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); }
324 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; }
325
326 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); }
327 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; }
328
329 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); }
330 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;}
331
332 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); }
333 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; }
334
335 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); }
336 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; }
337
338 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); }
339 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
340
341 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); }
342 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
343
344 inline oop oopDesc::obj_field_acquire(int offset) const {
345 return UseCompressedOops ?
346 decode_heap_oop((narrowOop)
347 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
348 : decode_heap_oop((oop)
349 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
350 }
351 inline void oopDesc::release_obj_field_put(int offset, oop value) {
352 UseCompressedOops ?
353 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
354 oop_store((volatile oop*) obj_field_addr<oop>(offset), value);
355 }
356
357 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); }
358 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); }
359
360 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); }
361 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), contents); }
362
363 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); }
364 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); }
365
366 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); }
367 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); }
368
369 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
370 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); }
371
372 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); }
373 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); }
374
375 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); }
376 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); }
377
378 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); }
379 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
380
381 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
382 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
383
384 inline int oopDesc::size_given_klass(Klass* klass) {
385 int lh = klass->layout_helper();
386 int s;
387
388 // lh is now a value computed at class initialization that may hint
389 // at the size. For instances, this is positive and equal to the
390 // size. For arrays, this is negative and provides log2 of the
391 // array element size. For other oops, it is zero and thus requires
392 // a virtual call.
393 //
394 // We go to all this trouble because the size computation is at the
395 // heart of phase 2 of mark-compaction, and called for every object,
396 // alive or dead. So the speed here is equal in importance to the
397 // speed of allocation.
398
399 if (lh > Klass::_lh_neutral_value) {
400 if (!Klass::layout_helper_needs_slow_path(lh)) {
401 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
402 } else {
403 s = klass->oop_size(this);
404 }
405 } else if (lh <= Klass::_lh_neutral_value) {
406 // The most common case is instances; fall through if so.
407 if (lh < Klass::_lh_neutral_value) {
408 // Second most common case is arrays. We have to fetch the
409 // length of the array, shift (multiply) it appropriately,
410 // up to wordSize, add the header, and align to object size.
411 size_t size_in_bytes;
412 #ifdef _M_IA64
413 // The Windows Itanium Aug 2002 SDK hoists this load above
414 // the check for s < 0. An oop at the end of the heap will
415 // cause an access violation if this load is performed on a non
416 // array oop. Making the reference volatile prohibits this.
417 // (%%% please explain by what magic the length is actually fetched!)
418 volatile int *array_length;
419 array_length = (volatile int *)( (intptr_t)this +
420 arrayOopDesc::length_offset_in_bytes() );
421 assert(array_length > 0, "Integer arithmetic problem somewhere");
422 // Put into size_t to avoid overflow.
423 size_in_bytes = (size_t) array_length;
424 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
425 #else
426 size_t array_length = (size_t) ((arrayOop)this)->length();
427 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
428 #endif
429 size_in_bytes += Klass::layout_helper_header_size(lh);
430
431 // This code could be simplified, but by keeping array_header_in_bytes
432 // in units of bytes and doing it this way we can round up just once,
433 // skipping the intermediate round to HeapWordSize. Cast the result
434 // of round_to to size_t to guarantee unsigned division == right shift.
435 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
436 HeapWordSize);
437
438 // ParNew (used by CMS), UseParallelGC and UseG1GC can change the length field
439 // of an "old copy" of an object array in the young gen so it indicates
440 // the grey portion of an already copied array. This will cause the first
441 // disjunct below to fail if the two comparands are computed across such
442 // a concurrent change.
443 // ParNew also runs with promotion labs (which look like int
444 // filler arrays) which are subject to changing their declared size
445 // when finally retiring a PLAB; this also can cause the first disjunct
446 // to fail for another worker thread that is concurrently walking the block
447 // offset table. Both these invariant failures are benign for their
448 // current uses; we relax the assertion checking to cover these two cases below:
449 // is_objArray() && is_forwarded() // covers first scenario above
450 // || is_typeArray() // covers second scenario above
451 // If and when UseParallelGC uses the same obj array oop stealing/chunking
452 // technique, we will need to suitably modify the assertion.
453 assert((s == klass->oop_size(this)) ||
454 (Universe::heap()->is_gc_active() &&
455 ((is_typeArray() && UseConcMarkSweepGC) ||
456 (is_objArray() && is_forwarded() && (UseConcMarkSweepGC || UseParallelGC || UseG1GC)))),
457 "wrong array object size");
458 } else {
459 // Must be zero, so bite the bullet and take the virtual call.
460 s = klass->oop_size(this);
461 }
462 }
463
464 assert(s % MinObjAlignment == 0, "alignment check");
465 assert(s > 0, "Bad size calculated");
466 return s;
467 }
468
469
470 inline int oopDesc::size() {
471 return size_given_klass(klass());
472 }
473
474 inline void update_barrier_set(void* p, oop v, bool release = false) {
475 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
476 oopDesc::bs()->write_ref_field(p, v, release);
477 }
478
479 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
480 oopDesc::bs()->write_ref_field_pre(p, v);
481 }
482
483 template <class T> inline void oop_store(T* p, oop v) {
484 if (always_do_update_barrier) {
485 oop_store((volatile T*)p, v);
486 } else {
487 update_barrier_set_pre(p, v);
488 oopDesc::encode_store_heap_oop(p, v);
489 // always_do_update_barrier == false =>
490 // Either we are at a safepoint (in GC) or CMS is not used. In both
491 // cases it's unnecessary to mark the card as dirty with release sematics.
492 update_barrier_set((void*)p, v, false /* release */); // cast away type
493 }
494 }
495
496 template <class T> inline void oop_store(volatile T* p, oop v) {
497 update_barrier_set_pre((T*)p, v); // cast away volatile
498 // Used by release_obj_field_put, so use release_store_ptr.
499 oopDesc::release_encode_store_heap_oop(p, v);
500 // When using CMS we must mark the card corresponding to p as dirty
501 // with release sematics to prevent that CMS sees the dirty card but
502 // not the new value v at p due to reordering of the two
503 // stores. Note that CMS has a concurrent precleaning phase, where
504 // it reads the card table while the Java threads are running.
505 update_barrier_set((void*)p, v, true /* release */); // cast away type
506 }
507
508 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
509 // (without having to remember the function name this calls).
510 inline void oop_store_raw(HeapWord* addr, oop value) {
511 if (UseCompressedOops) {
512 oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
513 } else {
514 oopDesc::encode_store_heap_oop((oop*)addr, value);
515 }
516 }
517
518 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
519 volatile HeapWord *dest,
520 oop compare_value,
521 bool prebarrier) {
522 if (UseCompressedOops) {
523 if (prebarrier) {
524 update_barrier_set_pre((narrowOop*)dest, exchange_value);
525 }
526 // encode exchange and compare value from oop to T
527 narrowOop val = encode_heap_oop(exchange_value);
528 narrowOop cmp = encode_heap_oop(compare_value);
529
530 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
531 // decode old from T to oop
532 return decode_heap_oop(old);
533 } else {
534 if (prebarrier) {
535 update_barrier_set_pre((oop*)dest, exchange_value);
536 }
537 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
538 }
539 }
540
541 // Used only for markSweep, scavenging
542 inline bool oopDesc::is_gc_marked() const {
543 assert(!CMSParallelFullGC, "CMSParallelFullGC should call parallel version.");
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 bool oopDesc::is_scavengable() const {
596 return Universe::heap()->is_scavengable(this);
597 }
598
599 // Used by scavengers
600 inline bool oopDesc::is_forwarded() const {
601 // The extra heap check is needed since the obj might be locked, in which case the
602 // mark would point to a stack location and have the sentinel bit cleared
603 return mark()->is_marked();
604 }
605
606 // Used by scavengers
607 inline void oopDesc::forward_to(oop p) {
608 assert(check_obj_alignment(p),
609 "forwarding to something not aligned");
610 assert(Universe::heap()->is_in_reserved(p),
611 "forwarding to something not in heap");
612 markOop m = markOopDesc::encode_pointer_as_mark(p);
613 assert(m->decode_pointer() == p, "encoding must be reversable");
614 set_mark(m);
615 }
616
617 // Used by parallel scavengers
618 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
619 assert(check_obj_alignment(p),
620 "forwarding to something not aligned");
621 assert(Universe::heap()->is_in_reserved(p),
622 "forwarding to something not in heap");
623 markOop m = markOopDesc::encode_pointer_as_mark(p);
624 assert(m->decode_pointer() == p, "encoding must be reversable");
625 return cas_set_mark(m, compare) == compare;
626 }
627
628 #if INCLUDE_ALL_GCS
629 inline oop oopDesc::forward_to_atomic(oop p) {
630 markOop oldMark = mark();
631 markOop forwardPtrMark = markOopDesc::encode_pointer_as_mark(p);
632 markOop curMark;
633
634 assert(forwardPtrMark->decode_pointer() == p, "encoding must be reversable");
635 assert(sizeof(markOop) == sizeof(intptr_t), "CAS below requires this.");
636
637 while (!oldMark->is_marked()) {
638 curMark = (markOop)Atomic::cmpxchg_ptr(forwardPtrMark, &_mark, oldMark);
639 assert(is_forwarded(), "object should have been forwarded");
640 if (curMark == oldMark) {
641 return NULL;
642 }
643 // If the CAS was unsuccessful then curMark->is_marked()
644 // should return true as another thread has CAS'd in another
645 // forwarding pointer.
646 oldMark = curMark;
647 }
648 return forwardee();
649 }
650 #endif
651
652 // Note that the forwardee is not the same thing as the displaced_mark.
653 // The forwardee is used when copying during scavenge and mark-sweep.
654 // It does need to clear the low two locking- and GC-related bits.
655 inline oop oopDesc::forwardee() const {
656 return (oop) mark()->decode_pointer();
657 }
658
659 inline bool oopDesc::has_displaced_mark() const {
660 return mark()->has_displaced_mark_helper();
661 }
662
663 inline markOop oopDesc::displaced_mark() const {
664 return mark()->displaced_mark_helper();
665 }
666
667 inline void oopDesc::set_displaced_mark(markOop m) {
668 mark()->set_displaced_mark_helper(m);
669 }
670
671 // The following method needs to be MT safe.
672 inline uint oopDesc::age() const {
673 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
674 if (has_displaced_mark()) {
675 return displaced_mark()->age();
676 } else {
677 return mark()->age();
678 }
679 }
680
681 inline void oopDesc::incr_age() {
682 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
683 if (has_displaced_mark()) {
684 set_displaced_mark(displaced_mark()->incr_age());
685 } else {
686 set_mark(mark()->incr_age());
687 }
688 }
689
690
691 inline intptr_t oopDesc::identity_hash() {
692 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
693 // Note: The mark must be read into local variable to avoid concurrent updates.
694 markOop mrk = mark();
695 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
696 return mrk->hash();
697 } else if (mrk->is_marked()) {
698 return mrk->hash();
699 } else {
700 return slow_identity_hash();
701 }
702 }
703
704 inline void oopDesc::ms_follow_contents() {
705 #ifdef ASSERT
706 if (!CMSParallelFullGC) {
707 assert (is_gc_marked(), "should be marked");
708 } else {
709 assert(MarkSweep::is_object_marked(this), "should be marked");
710 }
711 #endif
712 klass()->oop_ms_follow_contents(this);
713 }
714
715 inline int oopDesc::ms_adjust_pointers() {
716 debug_only(int check_size = size());
717 int s = klass()->oop_ms_adjust_pointers(this);
718 assert(s == check_size, "should be the same");
719 return s;
720 }
721
722 #if INCLUDE_ALL_GCS
723 inline void oopDesc::pc_follow_contents(ParCompactionManager* cm) {
724 klass()->oop_pc_follow_contents(this, cm);
725 }
726
727 inline void oopDesc::pc_update_contents() {
728 Klass* k = klass();
729 if (!k->oop_is_typeArray()) {
730 // It might contain oops beyond the header, so take the virtual call.
731 k->oop_pc_update_pointers(this);
732 }
733 // Else skip it. The TypeArrayKlass in the header never needs scavenging.
734 }
735
736 inline void oopDesc::ps_push_contents(PSPromotionManager* pm) {
737 Klass* k = klass();
738 if (!k->oop_is_typeArray()) {
739 // It might contain oops beyond the header, so take the virtual call.
740 k->oop_ps_push_contents(this, pm);
741 }
742 // Else skip it. The TypeArrayKlass in the header never needs scavenging.
743 }
744 #endif
745
746 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
747 \
748 inline int oopDesc::oop_iterate(OopClosureType* blk) { \
749 return klass()->oop_oop_iterate##nv_suffix(this, blk); \
750 } \
751 \
752 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
753 return klass()->oop_oop_iterate_bounded##nv_suffix(this, blk, mr); \
754 }
755
756
757 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) {
758 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
759 // the do_oop calls, but turns off all other features in ExtendedOopClosure.
760 NoHeaderExtendedOopClosure cl(blk);
761 return oop_iterate(&cl);
762 }
763
764 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
765 NoHeaderExtendedOopClosure cl(blk);
766 return oop_iterate(&cl, mr);
767 }
768
769 #if INCLUDE_ALL_GCS
770 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
771 \
772 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
773 return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
774 }
775 #else
776 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)
777 #endif
778
779 #define ALL_OOPDESC_OOP_ITERATE(OopClosureType, nv_suffix) \
780 OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
781 OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)
782
783 ALL_OOP_OOP_ITERATE_CLOSURES_1(ALL_OOPDESC_OOP_ITERATE)
784 ALL_OOP_OOP_ITERATE_CLOSURES_2(ALL_OOPDESC_OOP_ITERATE)
785
786 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP