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.
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_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 #ifdef TARGET_ARCH_x86
46 # include "bytes_x86.hpp"
47 #endif
48 #ifdef TARGET_ARCH_sparc
49 # include "bytes_sparc.hpp"
50 #endif
51 #ifdef TARGET_ARCH_zero
52 # include "bytes_zero.hpp"
53 #endif
54 #ifdef TARGET_ARCH_arm
55 # include "bytes_arm.hpp"
56 #endif
57 #ifdef TARGET_ARCH_ppc
58 # include "bytes_ppc.hpp"
59 #endif
60
61 // Implementation of all inlined member functions defined in oop.hpp
62 // We need a separate file to avoid circular references
63
64 inline void oopDesc::release_set_mark(markOop m) {
65 OrderAccess::release_store_ptr(&_mark, m);
66 }
67
68 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
69 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
70 }
71
72 inline Klass* oopDesc::klass() const {
73 if (UseCompressedClassPointers) {
74 return Klass::decode_klass_not_null(_metadata._compressed_klass);
75 } else {
76 return _metadata._klass;
77 }
78 }
79
80 inline Klass* oopDesc::klass_or_null() const volatile {
81 // can be NULL in CMS
82 if (UseCompressedClassPointers) {
83 return Klass::decode_klass(_metadata._compressed_klass);
84 } else {
85 return _metadata._klass;
86 }
87 }
88
89 inline int oopDesc::klass_gap_offset_in_bytes() {
90 assert(UseCompressedClassPointers, "only applicable to compressed klass pointers");
91 return oopDesc::klass_offset_in_bytes() + sizeof(narrowKlass);
92 }
93
94 inline Klass** oopDesc::klass_addr() {
95 // Only used internally and with CMS and will not work with
96 // UseCompressedOops
97 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers");
98 return (Klass**) &_metadata._klass;
99 }
100
101 inline narrowKlass* oopDesc::compressed_klass_addr() {
102 assert(UseCompressedClassPointers, "only called by compressed klass pointers");
103 return &_metadata._compressed_klass;
104 }
105
106 inline void oopDesc::set_klass(Klass* k) {
107 // since klasses are promoted no store check is needed
108 assert(Universe::is_bootstrapping() || k != NULL, "must be a real Klass*");
109 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass*");
110 if (UseCompressedClassPointers) {
111 *compressed_klass_addr() = Klass::encode_klass_not_null(k);
112 } else {
113 *klass_addr() = k;
114 }
115 }
116
117 inline int oopDesc::klass_gap() const {
118 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
119 }
120
121 inline void oopDesc::set_klass_gap(int v) {
122 if (UseCompressedClassPointers) {
123 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
124 }
125 }
126
127 inline void oopDesc::set_klass_to_list_ptr(oop k) {
128 // This is only to be used during GC, for from-space objects, so no
129 // barrier is needed.
130 if (UseCompressedClassPointers) {
131 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling)
132 } else {
133 _metadata._klass = (Klass*)(address)k;
134 }
135 }
136
137 inline oop oopDesc::list_ptr_from_klass() {
138 // This is only to be used during GC, for from-space objects.
139 if (UseCompressedClassPointers) {
140 return decode_heap_oop((narrowOop)_metadata._compressed_klass);
141 } else {
142 // Special case for GC
143 return (oop)(address)_metadata._klass;
144 }
145 }
146
147 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); }
148
149 inline bool oopDesc::is_a(Klass* k) const { return klass()->is_subtype_of(k); }
150
151 inline bool oopDesc::is_instance() const { return klass()->oop_is_instance(); }
152 inline bool oopDesc::is_instanceClassLoader() const { return klass()->oop_is_instanceClassLoader(); }
153 inline bool oopDesc::is_instanceMirror() const { return klass()->oop_is_instanceMirror(); }
154 inline bool oopDesc::is_instanceRef() const { return klass()->oop_is_instanceRef(); }
155 inline bool oopDesc::is_array() const { return klass()->oop_is_array(); }
156 inline bool oopDesc::is_objArray() const { return klass()->oop_is_objArray(); }
157 inline bool oopDesc::is_typeArray() const { return klass()->oop_is_typeArray(); }
158
159 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; }
160
161 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
162 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
163 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); }
164 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); }
165 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); }
166 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); }
167 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); }
168 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); }
169 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); }
170 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
171 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
172
173
174 // Functions for getting and setting oops within instance objects.
175 // If the oops are compressed, the type passed to these overloaded functions
176 // is narrowOop. All functions are overloaded so they can be called by
177 // template functions without conditionals (the compiler instantiates via
178 // the right type and inlines the appopriate code).
179
180 inline bool oopDesc::is_null(oop obj) { return obj == NULL; }
181 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }
182
183 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
184 // offset from the heap base. Saving the check for null can save instructions
185 // in inner GC loops so these are separated.
186
187 inline bool check_obj_alignment(oop obj) {
188 return cast_from_oop<intptr_t>(obj) % MinObjAlignmentInBytes == 0;
189 }
190
191 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
192 assert(!is_null(v), "oop value can never be zero");
193 assert(check_obj_alignment(v), "Address not aligned");
194 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
195 address base = Universe::narrow_oop_base();
196 int shift = Universe::narrow_oop_shift();
197 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
198 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
199 uint64_t result = pd >> shift;
200 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
201 assert(decode_heap_oop(result) == v, "reversibility");
202 return (narrowOop)result;
203 }
204
205 inline narrowOop oopDesc::encode_heap_oop(oop v) {
206 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
207 }
208
209 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
210 assert(!is_null(v), "narrow oop value can never be zero");
211 address base = Universe::narrow_oop_base();
212 int shift = Universe::narrow_oop_shift();
213 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
214 assert(check_obj_alignment(result), err_msg("address not aligned: " INTPTR_FORMAT, p2i((void*) result)));
215 return result;
216 }
217
218 inline oop oopDesc::decode_heap_oop(narrowOop v) {
219 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
220 }
221
222 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
223 inline oop oopDesc::decode_heap_oop(oop v) { return v; }
224
225 // Load an oop out of the Java heap as is without decoding.
226 // Called by GC to check for null before decoding.
227 inline oop oopDesc::load_heap_oop(oop* p) { return *p; }
228 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
229
230 // Load and decode an oop out of the Java heap into a wide oop.
231 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
232 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
233 return decode_heap_oop_not_null(*p);
234 }
235
236 // Load and decode an oop out of the heap accepting null
237 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
238 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
239 return decode_heap_oop(*p);
240 }
241
242 // Store already encoded heap oop into the heap.
243 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; }
244 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
245
246 // Encode and store a heap oop.
247 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
248 *p = encode_heap_oop_not_null(v);
249 }
250 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
251
252 // Encode and store a heap oop allowing for null.
253 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
254 *p = encode_heap_oop(v);
255 }
256 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
257
258 // Store heap oop as is for volatile fields.
259 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
260 OrderAccess::release_store_ptr(p, v);
261 }
262 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
263 narrowOop v) {
264 OrderAccess::release_store(p, v);
265 }
266
267 inline void oopDesc::release_encode_store_heap_oop_not_null(
268 volatile narrowOop* p, oop v) {
269 // heap oop is not pointer sized.
270 OrderAccess::release_store(p, encode_heap_oop_not_null(v));
271 }
272
273 inline void oopDesc::release_encode_store_heap_oop_not_null(
274 volatile oop* p, oop v) {
275 OrderAccess::release_store_ptr(p, v);
276 }
277
278 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
279 oop v) {
280 OrderAccess::release_store_ptr(p, v);
281 }
282 inline void oopDesc::release_encode_store_heap_oop(
283 volatile narrowOop* p, oop v) {
284 OrderAccess::release_store(p, encode_heap_oop(v));
285 }
286
287
288 // These functions are only used to exchange oop fields in instances,
289 // not headers.
290 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
291 if (UseCompressedOops) {
292 // encode exchange value from oop to T
293 narrowOop val = encode_heap_oop(exchange_value);
294 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
295 // decode old from T to oop
296 return decode_heap_oop(old);
297 } else {
298 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
299 }
300 }
301
302 // In order to put or get a field out of an instance, must first check
303 // if the field has been compressed and uncompress it.
304 inline oop oopDesc::obj_field(int offset) const {
305 return UseCompressedOops ?
306 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
307 load_decode_heap_oop(obj_field_addr<oop>(offset));
308 }
309 inline volatile oop oopDesc::obj_field_volatile(int offset) const {
310 volatile oop value = obj_field(offset);
311 OrderAccess::acquire();
312 return value;
313 }
314 inline void oopDesc::obj_field_put(int offset, oop value) {
315 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
316 oop_store(obj_field_addr<oop>(offset), value);
317 }
318
319 inline Metadata* oopDesc::metadata_field(int offset) const {
320 return *metadata_field_addr(offset);
321 }
322
323 inline void oopDesc::metadata_field_put(int offset, Metadata* value) {
324 *metadata_field_addr(offset) = value;
325 }
326
327 inline void oopDesc::obj_field_put_raw(int offset, oop value) {
328 UseCompressedOops ?
329 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
330 encode_store_heap_oop(obj_field_addr<oop>(offset), value);
331 }
332 inline void oopDesc::obj_field_put_volatile(int offset, oop value) {
333 OrderAccess::release();
334 obj_field_put(offset, value);
335 OrderAccess::fence();
336 }
337
338 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); }
339 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; }
340
341 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); }
342 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (jint) contents; }
343
344 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); }
345 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; }
346
347 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); }
348 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; }
349
350 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); }
351 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;}
352
353 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); }
354 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; }
355
356 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); }
357 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; }
358
359 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); }
360 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
361
362 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); }
363 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
364
365 inline oop oopDesc::obj_field_acquire(int offset) const {
366 return UseCompressedOops ?
367 decode_heap_oop((narrowOop)
368 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
369 : decode_heap_oop((oop)
370 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
371 }
372 inline void oopDesc::release_obj_field_put(int offset, oop value) {
373 UseCompressedOops ?
374 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
375 oop_store((volatile oop*) obj_field_addr<oop>(offset), value);
376 }
377
378 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); }
379 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); }
380
381 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); }
382 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), contents); }
383
384 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); }
385 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); }
386
387 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); }
388 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); }
389
390 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
391 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); }
392
393 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); }
394 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); }
395
396 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); }
397 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); }
398
399 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); }
400 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
401
402 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
403 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
404
405 inline int oopDesc::size_given_klass(Klass* klass) {
406 int lh = klass->layout_helper();
407 int s;
408
409 // lh is now a value computed at class initialization that may hint
410 // at the size. For instances, this is positive and equal to the
411 // size. For arrays, this is negative and provides log2 of the
412 // array element size. For other oops, it is zero and thus requires
413 // a virtual call.
414 //
415 // We go to all this trouble because the size computation is at the
416 // heart of phase 2 of mark-compaction, and called for every object,
417 // alive or dead. So the speed here is equal in importance to the
418 // speed of allocation.
419
420 if (lh > Klass::_lh_neutral_value) {
421 if (!Klass::layout_helper_needs_slow_path(lh)) {
422 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
423 } else {
424 s = klass->oop_size(this);
425 }
426 } else if (lh <= Klass::_lh_neutral_value) {
427 // The most common case is instances; fall through if so.
428 if (lh < Klass::_lh_neutral_value) {
429 // Second most common case is arrays. We have to fetch the
430 // length of the array, shift (multiply) it appropriately,
431 // up to wordSize, add the header, and align to object size.
432 size_t size_in_bytes;
433 #ifdef _M_IA64
434 // The Windows Itanium Aug 2002 SDK hoists this load above
435 // the check for s < 0. An oop at the end of the heap will
436 // cause an access violation if this load is performed on a non
437 // array oop. Making the reference volatile prohibits this.
438 // (%%% please explain by what magic the length is actually fetched!)
439 volatile int *array_length;
440 array_length = (volatile int *)( (intptr_t)this +
441 arrayOopDesc::length_offset_in_bytes() );
442 assert(array_length > 0, "Integer arithmetic problem somewhere");
443 // Put into size_t to avoid overflow.
444 size_in_bytes = (size_t) array_length;
445 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
446 #else
447 size_t array_length = (size_t) ((arrayOop)this)->length();
448 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
449 #endif
450 size_in_bytes += Klass::layout_helper_header_size(lh);
451
452 // This code could be simplified, but by keeping array_header_in_bytes
453 // in units of bytes and doing it this way we can round up just once,
454 // skipping the intermediate round to HeapWordSize. Cast the result
455 // of round_to to size_t to guarantee unsigned division == right shift.
456 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
457 HeapWordSize);
458
459 // UseParNewGC, UseParallelGC and UseG1GC can change the length field
460 // of an "old copy" of an object array in the young gen so it indicates
461 // the grey portion of an already copied array. This will cause the first
462 // disjunct below to fail if the two comparands are computed across such
463 // a concurrent change.
464 // UseParNewGC also runs with promotion labs (which look like int
465 // filler arrays) which are subject to changing their declared size
466 // when finally retiring a PLAB; this also can cause the first disjunct
467 // to fail for another worker thread that is concurrently walking the block
468 // offset table. Both these invariant failures are benign for their
469 // current uses; we relax the assertion checking to cover these two cases below:
470 // is_objArray() && is_forwarded() // covers first scenario above
471 // || is_typeArray() // covers second scenario above
472 // If and when UseParallelGC uses the same obj array oop stealing/chunking
473 // technique, we will need to suitably modify the assertion.
474 assert((s == klass->oop_size(this)) ||
475 (Universe::heap()->is_gc_active() &&
476 ((is_typeArray() && UseParNewGC) ||
477 (is_objArray() && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))),
478 "wrong array object size");
479 } else {
480 // Must be zero, so bite the bullet and take the virtual call.
481 s = klass->oop_size(this);
482 }
483 }
484
485 assert(s % MinObjAlignment == 0, "alignment check");
486 assert(s > 0, "Bad size calculated");
487 return s;
488 }
489
490
491 inline int oopDesc::size() {
492 return size_given_klass(klass());
493 }
494
495 inline void update_barrier_set(void* p, oop v, bool release = false) {
496 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
497 oopDesc::bs()->write_ref_field(p, v, release);
498 }
499
500 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
501 oopDesc::bs()->write_ref_field_pre(p, v);
502 }
503
504 template <class T> inline void oop_store(T* p, oop v) {
505 if (always_do_update_barrier) {
506 oop_store((volatile T*)p, v);
507 } else {
508 update_barrier_set_pre(p, v);
509 oopDesc::encode_store_heap_oop(p, v);
510 // always_do_update_barrier == false =>
511 // Either we are at a safepoint (in GC) or CMS is not used. In both
512 // cases it's unnecessary to mark the card as dirty with release sematics.
513 update_barrier_set((void*)p, v, false /* release */); // cast away type
514 }
515 }
516
517 template <class T> inline void oop_store(volatile T* p, oop v) {
518 update_barrier_set_pre((T*)p, v); // cast away volatile
519 // Used by release_obj_field_put, so use release_store_ptr.
520 oopDesc::release_encode_store_heap_oop(p, v);
521 // When using CMS we must mark the card corresponding to p as dirty
522 // with release sematics to prevent that CMS sees the dirty card but
523 // not the new value v at p due to reordering of the two
524 // stores. Note that CMS has a concurrent precleaning phase, where
525 // it reads the card table while the Java threads are running.
526 update_barrier_set((void*)p, v, true /* release */); // cast away type
527 }
528
529 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
530 // (without having to remember the function name this calls).
531 inline void oop_store_raw(HeapWord* addr, oop value) {
532 if (UseCompressedOops) {
533 oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
534 } else {
535 oopDesc::encode_store_heap_oop((oop*)addr, value);
536 }
537 }
538
539 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
540 volatile HeapWord *dest,
541 oop compare_value,
542 bool prebarrier) {
543 if (UseCompressedOops) {
544 if (prebarrier) {
545 update_barrier_set_pre((narrowOop*)dest, exchange_value);
546 }
547 // encode exchange and compare value from oop to T
548 narrowOop val = encode_heap_oop(exchange_value);
549 narrowOop cmp = encode_heap_oop(compare_value);
550
551 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
552 // decode old from T to oop
553 return decode_heap_oop(old);
554 } else {
555 if (prebarrier) {
556 update_barrier_set_pre((oop*)dest, exchange_value);
557 }
558 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
559 }
560 }
561
562 // Used only for markSweep, scavenging
563 inline bool oopDesc::is_gc_marked() const {
564 return mark()->is_marked();
565 }
566
567 inline bool oopDesc::is_locked() const {
568 return mark()->is_locked();
569 }
570
571 inline bool oopDesc::is_unlocked() const {
572 return mark()->is_unlocked();
573 }
574
575 inline bool oopDesc::has_bias_pattern() const {
576 return mark()->has_bias_pattern();
577 }
578
579
580 // used only for asserts
581 inline bool oopDesc::is_oop(bool ignore_mark_word) const {
582 oop obj = (oop) this;
583 if (!check_obj_alignment(obj)) return false;
584 if (!Universe::heap()->is_in_reserved(obj)) return false;
585 // obj is aligned and accessible in heap
586 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false;
587
588 // Header verification: the mark is typically non-NULL. If we're
589 // at a safepoint, it must not be null.
590 // Outside of a safepoint, the header could be changing (for example,
591 // another thread could be inflating a lock on this object).
592 if (ignore_mark_word) {
593 return true;
594 }
595 if (mark() != NULL) {
596 return true;
597 }
598 return !SafepointSynchronize::is_at_safepoint();
599 }
600
601
602 // used only for asserts
603 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
604 return this == NULL ? true : is_oop(ignore_mark_word);
605 }
606
607 #ifndef PRODUCT
608 // used only for asserts
609 inline bool oopDesc::is_unlocked_oop() const {
610 if (!Universe::heap()->is_in_reserved(this)) return false;
611 return mark()->is_unlocked();
612 }
613 #endif // PRODUCT
614
615 inline void oopDesc::follow_contents(void) {
616 assert (is_gc_marked(), "should be marked");
617 klass()->oop_follow_contents(this);
618 }
619
620 // Used by scavengers
621
622 inline bool oopDesc::is_forwarded() const {
623 // The extra heap check is needed since the obj might be locked, in which case the
624 // mark would point to a stack location and have the sentinel bit cleared
625 return mark()->is_marked();
626 }
627
628 // Used by scavengers
629 inline void oopDesc::forward_to(oop p) {
630 assert(check_obj_alignment(p),
631 "forwarding to something not aligned");
632 assert(Universe::heap()->is_in_reserved(p),
633 "forwarding to something not in heap");
634 markOop m = markOopDesc::encode_pointer_as_mark(p);
635 assert(m->decode_pointer() == p, "encoding must be reversable");
636 set_mark(m);
637 }
638
639 // Used by parallel scavengers
640 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
641 assert(check_obj_alignment(p),
642 "forwarding to something not aligned");
643 assert(Universe::heap()->is_in_reserved(p),
644 "forwarding to something not in heap");
645 markOop m = markOopDesc::encode_pointer_as_mark(p);
646 assert(m->decode_pointer() == p, "encoding must be reversable");
647 return cas_set_mark(m, compare) == compare;
648 }
649
650 // Note that the forwardee is not the same thing as the displaced_mark.
651 // The forwardee is used when copying during scavenge and mark-sweep.
652 // It does need to clear the low two locking- and GC-related bits.
653 inline oop oopDesc::forwardee() const {
654 return (oop) mark()->decode_pointer();
655 }
656
657 inline bool oopDesc::has_displaced_mark() const {
658 return mark()->has_displaced_mark_helper();
659 }
660
661 inline markOop oopDesc::displaced_mark() const {
662 return mark()->displaced_mark_helper();
663 }
664
665 inline void oopDesc::set_displaced_mark(markOop m) {
666 mark()->set_displaced_mark_helper(m);
667 }
668
669 // The following method needs to be MT safe.
670 inline uint oopDesc::age() const {
671 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
672 if (has_displaced_mark()) {
673 return displaced_mark()->age();
674 } else {
675 return mark()->age();
676 }
677 }
678
679 inline void oopDesc::incr_age() {
680 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
681 if (has_displaced_mark()) {
682 set_displaced_mark(displaced_mark()->incr_age());
683 } else {
684 set_mark(mark()->incr_age());
685 }
686 }
687
688
689 inline intptr_t oopDesc::identity_hash() {
690 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
691 // Note: The mark must be read into local variable to avoid concurrent updates.
692 markOop mrk = mark();
693 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
694 return mrk->hash();
695 } else if (mrk->is_marked()) {
696 return mrk->hash();
697 } else {
698 return slow_identity_hash();
699 }
700 }
701
702 inline int oopDesc::adjust_pointers() {
703 debug_only(int check_size = size());
704 int s = klass()->oop_adjust_pointers(this);
705 assert(s == check_size, "should be the same");
706 return s;
707 }
708
709 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
710 \
711 inline int oopDesc::oop_iterate(OopClosureType* blk) { \
712 SpecializationStats::record_call(); \
713 return klass()->oop_oop_iterate##nv_suffix(this, blk); \
714 } \
715 \
716 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
717 SpecializationStats::record_call(); \
718 return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \
719 }
720
721
722 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) {
723 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
724 // the do_oop calls, but turns off all other features in ExtendedOopClosure.
725 NoHeaderExtendedOopClosure cl(blk);
726 return oop_iterate(&cl);
727 }
728
729 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
730 NoHeaderExtendedOopClosure cl(blk);
731 return oop_iterate(&cl, mr);
732 }
733
734 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN)
735 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN)
736
737 #if INCLUDE_ALL_GCS
738 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
739 \
740 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
741 SpecializationStats::record_call(); \
742 return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
743 }
744
745 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN)
746 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN)
747 #endif // INCLUDE_ALL_GCS
748
749 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP