1 /*
2 * Copyright (c) 1997, 2013, 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.hpp"
39 #include "oops/markOop.inline.hpp"
40 #include "oops/oop.hpp"
41 #include "runtime/atomic.hpp"
42 #include "runtime/os.hpp"
43 #include "utilities/macros.hpp"
44 #ifdef TARGET_ARCH_x86
45 # include "bytes_x86.hpp"
46 #endif
47 #ifdef TARGET_ARCH_sparc
48 # include "bytes_sparc.hpp"
49 #endif
50 #ifdef TARGET_ARCH_zero
51 # include "bytes_zero.hpp"
52 #endif
53 #ifdef TARGET_ARCH_arm
54 # include "bytes_arm.hpp"
55 #endif
56 #ifdef TARGET_ARCH_ppc
57 # include "bytes_ppc.hpp"
58 #endif
59
60 // Implementation of all inlined member functions defined in oop.hpp
61 // We need a separate file to avoid circular references
62
63 inline void oopDesc::release_set_mark(markOop m) {
64 OrderAccess::release_store_ptr(&_mark, m);
65 }
66
67 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
68 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
69 }
70
71 inline Klass* oopDesc::klass() const {
72 if (UseCompressedKlassPointers) {
73 return decode_klass_not_null(_metadata._compressed_klass);
74 } else {
75 return _metadata._klass;
76 }
77 }
78
79 inline Klass* oopDesc::klass_or_null() const volatile {
80 // can be NULL in CMS
81 if (UseCompressedKlassPointers) {
82 return decode_klass(_metadata._compressed_klass);
83 } else {
84 return _metadata._klass;
85 }
86 }
87
88 inline int oopDesc::klass_gap_offset_in_bytes() {
89 assert(UseCompressedKlassPointers, "only applicable to compressed klass pointers");
90 return oopDesc::klass_offset_in_bytes() + sizeof(narrowOop);
91 }
92
93 inline Klass** oopDesc::klass_addr() {
94 // Only used internally and with CMS and will not work with
95 // UseCompressedOops
96 assert(!UseCompressedKlassPointers, "only supported with uncompressed klass pointers");
97 return (Klass**) &_metadata._klass;
98 }
99
100 inline narrowOop* oopDesc::compressed_klass_addr() {
101 assert(UseCompressedKlassPointers, "only called by compressed klass pointers");
102 return (narrowOop*) &_metadata._compressed_klass;
103 }
104
105 inline void oopDesc::set_klass(Klass* k) {
106 // since klasses are promoted no store check is needed
107 assert(Universe::is_bootstrapping() || k != NULL, "must be a real Klass*");
108 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass*");
109 if (UseCompressedKlassPointers) {
110 *compressed_klass_addr() = encode_klass_not_null(k);
111 } else {
112 *klass_addr() = k;
113 }
114 }
115
116 inline int oopDesc::klass_gap() const {
117 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
118 }
119
120 inline void oopDesc::set_klass_gap(int v) {
121 if (UseCompressedKlassPointers) {
122 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
123 }
124 }
125
126 inline void oopDesc::set_klass_to_list_ptr(oop k) {
127 // This is only to be used during GC, for from-space objects, so no
128 // barrier is needed.
129 if (UseCompressedKlassPointers) {
130 _metadata._compressed_klass = encode_heap_oop(k); // may be null (parnew overflow handling)
131 } else {
132 _metadata._klass = (Klass*)(address)k;
133 }
134 }
135
136 inline oop oopDesc::list_ptr_from_klass() {
137 // This is only to be used during GC, for from-space objects.
138 if (UseCompressedKlassPointers) {
139 return decode_heap_oop(_metadata._compressed_klass);
140 } else {
141 // Special case for GC
142 return (oop)(address)_metadata._klass;
143 }
144 }
145
146 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); }
147
148 inline bool oopDesc::is_a(Klass* k) const { return klass()->is_subtype_of(k); }
149
150 inline bool oopDesc::is_instance() const { return klass()->oop_is_instance(); }
151 inline bool oopDesc::is_instanceMirror() const { return klass()->oop_is_instanceMirror(); }
152 inline bool oopDesc::is_instanceRef() const { return klass()->oop_is_instanceRef(); }
153 inline bool oopDesc::is_array() const { return klass()->oop_is_array(); }
154 inline bool oopDesc::is_objArray() const { return klass()->oop_is_objArray(); }
155 inline bool oopDesc::is_typeArray() const { return klass()->oop_is_typeArray(); }
156
157 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; }
158
159 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
160 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
161 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); }
162 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); }
163 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); }
164 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); }
165 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); }
166 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); }
167 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); }
168 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
169 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
170
171
172 // Functions for getting and setting oops within instance objects.
173 // If the oops are compressed, the type passed to these overloaded functions
174 // is narrowOop. All functions are overloaded so they can be called by
175 // template functions without conditionals (the compiler instantiates via
176 // the right type and inlines the appopriate code).
177
178 inline bool oopDesc::is_null(oop obj) { return obj == NULL; }
179 inline bool oopDesc::is_null(Klass* obj) { return obj == NULL; }
180 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }
181
182 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
183 // offset from the heap base. Saving the check for null can save instructions
184 // in inner GC loops so these are separated.
185
186 inline bool check_obj_alignment(oop obj) {
187 return (intptr_t)obj % MinObjAlignmentInBytes == 0;
188 }
189 inline bool check_klass_alignment(Klass* obj) {
190 return (intptr_t)obj % KlassAlignmentInBytes == 0;
191 }
192
193 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
194 assert(!is_null(v), "oop value can never be zero");
195 assert(check_obj_alignment(v), "Address not aligned");
196 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
197 address base = Universe::narrow_oop_base();
198 int shift = Universe::narrow_oop_shift();
199 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
200 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
201 uint64_t result = pd >> shift;
202 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
203 assert(decode_heap_oop(result) == v, "reversibility");
204 return (narrowOop)result;
205 }
206
207 inline narrowOop oopDesc::encode_heap_oop(oop v) {
208 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
209 }
210
211 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
212 assert(!is_null(v), "narrow oop value can never be zero");
213 address base = Universe::narrow_oop_base();
214 int shift = Universe::narrow_oop_shift();
215 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
216 assert(check_obj_alignment(result), err_msg("address not aligned: " PTR_FORMAT, (void*) result));
217 return result;
218 }
219
220 inline oop oopDesc::decode_heap_oop(narrowOop v) {
221 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
222 }
223
224 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
225 inline oop oopDesc::decode_heap_oop(oop v) { return v; }
226
227 // Encoding and decoding for klass field. It is copied code, but someday
228 // might not be the same as oop.
229
230 inline narrowOop oopDesc::encode_klass_not_null(Klass* v) {
231 assert(!is_null(v), "klass value can never be zero");
232 assert(check_klass_alignment(v), "Address not aligned");
233 address base = Universe::narrow_klass_base();
234 int shift = Universe::narrow_klass_shift();
235 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
236 assert(KlassEncodingMetaspaceMax > pd, "change encoding max if new encoding");
237 uint64_t result = pd >> shift;
238 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow klass pointer overflow");
239 assert(decode_klass(result) == v, "reversibility");
240 return (narrowOop)result;
241 }
242
243 inline narrowOop oopDesc::encode_klass(Klass* v) {
244 return (is_null(v)) ? (narrowOop)0 : encode_klass_not_null(v);
245 }
246
247 inline Klass* oopDesc::decode_klass_not_null(narrowOop v) {
248 assert(!is_null(v), "narrow oop value can never be zero");
249 address base = Universe::narrow_klass_base();
250 int shift = Universe::narrow_klass_shift();
251 Klass* result = (Klass*)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
252 assert(check_klass_alignment(result), err_msg("address not aligned: " PTR_FORMAT, (void*) result));
253 return result;
254 }
255
256 inline Klass* oopDesc::decode_klass(narrowOop v) {
257 return is_null(v) ? (Klass*)NULL : decode_klass_not_null(v);
258 }
259
260 // Load an oop out of the Java heap as is without decoding.
261 // Called by GC to check for null before decoding.
262 inline oop oopDesc::load_heap_oop(oop* p) { return *p; }
263 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
264
265 // Load and decode an oop out of the Java heap into a wide oop.
266 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
267 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
268 return decode_heap_oop_not_null(*p);
269 }
270
271 // Load and decode an oop out of the heap accepting null
272 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
273 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
274 return decode_heap_oop(*p);
275 }
276
277 // Store already encoded heap oop into the heap.
278 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; }
279 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
280
281 // Encode and store a heap oop.
282 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
283 *p = encode_heap_oop_not_null(v);
284 }
285 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
286
287 // Encode and store a heap oop allowing for null.
288 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
289 *p = encode_heap_oop(v);
290 }
291 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
292
293 // Store heap oop as is for volatile fields.
294 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
295 OrderAccess::release_store_ptr(p, v);
296 }
297 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
298 narrowOop v) {
299 OrderAccess::release_store(p, v);
300 }
301
302 inline void oopDesc::release_encode_store_heap_oop_not_null(
303 volatile narrowOop* p, oop v) {
304 // heap oop is not pointer sized.
305 OrderAccess::release_store(p, encode_heap_oop_not_null(v));
306 }
307
308 inline void oopDesc::release_encode_store_heap_oop_not_null(
309 volatile oop* p, oop v) {
310 OrderAccess::release_store_ptr(p, v);
311 }
312
313 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
314 oop v) {
315 OrderAccess::release_store_ptr(p, v);
316 }
317 inline void oopDesc::release_encode_store_heap_oop(
318 volatile narrowOop* p, oop v) {
319 OrderAccess::release_store(p, encode_heap_oop(v));
320 }
321
322
323 // These functions are only used to exchange oop fields in instances,
324 // not headers.
325 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
326 if (UseCompressedOops) {
327 // encode exchange value from oop to T
328 narrowOop val = encode_heap_oop(exchange_value);
329 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
330 // decode old from T to oop
331 return decode_heap_oop(old);
332 } else {
333 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
334 }
335 }
336
337 // In order to put or get a field out of an instance, must first check
338 // if the field has been compressed and uncompress it.
339 inline oop oopDesc::obj_field(int offset) const {
340 return UseCompressedOops ?
341 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
342 load_decode_heap_oop(obj_field_addr<oop>(offset));
343 }
344 inline volatile oop oopDesc::obj_field_volatile(int offset) const {
345 volatile oop value = obj_field(offset);
346 OrderAccess::acquire();
347 return value;
348 }
349 inline void oopDesc::obj_field_put(int offset, oop value) {
350 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
351 oop_store(obj_field_addr<oop>(offset), value);
352 }
353
354 inline Metadata* oopDesc::metadata_field(int offset) const {
355 return *metadata_field_addr(offset);
356 }
357
358 inline void oopDesc::metadata_field_put(int offset, Metadata* value) {
359 *metadata_field_addr(offset) = value;
360 }
361
362 inline void oopDesc::obj_field_put_raw(int offset, oop value) {
363 UseCompressedOops ?
364 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
365 encode_store_heap_oop(obj_field_addr<oop>(offset), value);
366 }
367 inline void oopDesc::obj_field_put_volatile(int offset, oop value) {
368 OrderAccess::release();
369 obj_field_put(offset, value);
370 OrderAccess::fence();
371 }
372
373 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); }
374 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; }
375
376 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); }
377 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (jint) contents; }
378
379 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); }
380 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; }
381
382 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); }
383 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; }
384
385 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); }
386 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;}
387
388 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); }
389 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; }
390
391 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); }
392 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; }
393
394 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); }
395 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
396
397 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); }
398 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
399
400 inline oop oopDesc::obj_field_acquire(int offset) const {
401 return UseCompressedOops ?
402 decode_heap_oop((narrowOop)
403 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
404 : decode_heap_oop((oop)
405 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
406 }
407 inline void oopDesc::release_obj_field_put(int offset, oop value) {
408 UseCompressedOops ?
409 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
410 oop_store((volatile oop*) obj_field_addr<oop>(offset), value);
411 }
412
413 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); }
414 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); }
415
416 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); }
417 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), contents); }
418
419 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); }
420 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); }
421
422 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); }
423 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); }
424
425 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
426 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); }
427
428 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); }
429 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); }
430
431 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); }
432 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); }
433
434 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); }
435 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
436
437 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
438 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
439
440 inline int oopDesc::size_given_klass(Klass* klass) {
441 int lh = klass->layout_helper();
442 int s;
443
444 // lh is now a value computed at class initialization that may hint
445 // at the size. For instances, this is positive and equal to the
446 // size. For arrays, this is negative and provides log2 of the
447 // array element size. For other oops, it is zero and thus requires
448 // a virtual call.
449 //
450 // We go to all this trouble because the size computation is at the
451 // heart of phase 2 of mark-compaction, and called for every object,
452 // alive or dead. So the speed here is equal in importance to the
453 // speed of allocation.
454
455 if (lh > Klass::_lh_neutral_value) {
456 if (!Klass::layout_helper_needs_slow_path(lh)) {
457 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
458 } else {
459 s = klass->oop_size(this);
460 }
461 } else if (lh <= Klass::_lh_neutral_value) {
462 // The most common case is instances; fall through if so.
463 if (lh < Klass::_lh_neutral_value) {
464 // Second most common case is arrays. We have to fetch the
465 // length of the array, shift (multiply) it appropriately,
466 // up to wordSize, add the header, and align to object size.
467 size_t size_in_bytes;
468 #ifdef _M_IA64
469 // The Windows Itanium Aug 2002 SDK hoists this load above
470 // the check for s < 0. An oop at the end of the heap will
471 // cause an access violation if this load is performed on a non
472 // array oop. Making the reference volatile prohibits this.
473 // (%%% please explain by what magic the length is actually fetched!)
474 volatile int *array_length;
475 array_length = (volatile int *)( (intptr_t)this +
476 arrayOopDesc::length_offset_in_bytes() );
477 assert(array_length > 0, "Integer arithmetic problem somewhere");
478 // Put into size_t to avoid overflow.
479 size_in_bytes = (size_t) array_length;
480 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
481 #else
482 size_t array_length = (size_t) ((arrayOop)this)->length();
483 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
484 #endif
485 size_in_bytes += Klass::layout_helper_header_size(lh);
486
487 // This code could be simplified, but by keeping array_header_in_bytes
488 // in units of bytes and doing it this way we can round up just once,
489 // skipping the intermediate round to HeapWordSize. Cast the result
490 // of round_to to size_t to guarantee unsigned division == right shift.
491 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
492 HeapWordSize);
493
494 // UseParNewGC, UseParallelGC and UseG1GC can change the length field
495 // of an "old copy" of an object array in the young gen so it indicates
496 // the grey portion of an already copied array. This will cause the first
497 // disjunct below to fail if the two comparands are computed across such
498 // a concurrent change.
499 // UseParNewGC also runs with promotion labs (which look like int
500 // filler arrays) which are subject to changing their declared size
501 // when finally retiring a PLAB; this also can cause the first disjunct
502 // to fail for another worker thread that is concurrently walking the block
503 // offset table. Both these invariant failures are benign for their
504 // current uses; we relax the assertion checking to cover these two cases below:
505 // is_objArray() && is_forwarded() // covers first scenario above
506 // || is_typeArray() // covers second scenario above
507 // If and when UseParallelGC uses the same obj array oop stealing/chunking
508 // technique, we will need to suitably modify the assertion.
509 assert((s == klass->oop_size(this)) ||
510 (Universe::heap()->is_gc_active() &&
511 ((is_typeArray() && UseParNewGC) ||
512 (is_objArray() && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))),
513 "wrong array object size");
514 } else {
515 // Must be zero, so bite the bullet and take the virtual call.
516 s = klass->oop_size(this);
517 }
518 }
519
520 assert(s % MinObjAlignment == 0, "alignment check");
521 assert(s > 0, "Bad size calculated");
522 return s;
523 }
524
525
526 inline int oopDesc::size() {
527 return size_given_klass(klass());
528 }
529
530 inline void update_barrier_set(void* p, oop v) {
531 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
532 oopDesc::bs()->write_ref_field(p, v);
533 }
534
535 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
536 oopDesc::bs()->write_ref_field_pre(p, v);
537 }
538
539 template <class T> inline void oop_store(T* p, oop v) {
540 if (always_do_update_barrier) {
541 oop_store((volatile T*)p, v);
542 } else {
543 update_barrier_set_pre(p, v);
544 oopDesc::encode_store_heap_oop(p, v);
545 update_barrier_set((void*)p, v); // cast away type
546 }
547 }
548
549 template <class T> inline void oop_store(volatile T* p, oop v) {
550 update_barrier_set_pre((T*)p, v); // cast away volatile
551 // Used by release_obj_field_put, so use release_store_ptr.
552 oopDesc::release_encode_store_heap_oop(p, v);
553 update_barrier_set((void*)p, v); // cast away type
554 }
555
556 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
557 // (without having to remember the function name this calls).
558 inline void oop_store_raw(HeapWord* addr, oop value) {
559 if (UseCompressedOops) {
560 oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
561 } else {
562 oopDesc::encode_store_heap_oop((oop*)addr, value);
563 }
564 }
565
566 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
567 volatile HeapWord *dest,
568 oop compare_value,
569 bool prebarrier) {
570 if (UseCompressedOops) {
571 if (prebarrier) {
572 update_barrier_set_pre((narrowOop*)dest, exchange_value);
573 }
574 // encode exchange and compare value from oop to T
575 narrowOop val = encode_heap_oop(exchange_value);
576 narrowOop cmp = encode_heap_oop(compare_value);
577
578 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
579 // decode old from T to oop
580 return decode_heap_oop(old);
581 } else {
582 if (prebarrier) {
583 update_barrier_set_pre((oop*)dest, exchange_value);
584 }
585 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
586 }
587 }
588
589 // Used only for markSweep, scavenging
590 inline bool oopDesc::is_gc_marked() const {
591 return mark()->is_marked();
592 }
593
594 inline bool oopDesc::is_locked() const {
595 return mark()->is_locked();
596 }
597
598 inline bool oopDesc::is_unlocked() const {
599 return mark()->is_unlocked();
600 }
601
602 inline bool oopDesc::has_bias_pattern() const {
603 return mark()->has_bias_pattern();
604 }
605
606
607 // used only for asserts
608 inline bool oopDesc::is_oop(bool ignore_mark_word) const {
609 oop obj = (oop) this;
610 if (!check_obj_alignment(obj)) return false;
611 if (!Universe::heap()->is_in_reserved(obj)) return false;
612 // obj is aligned and accessible in heap
613 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false;
614
615 // Header verification: the mark is typically non-NULL. If we're
616 // at a safepoint, it must not be null.
617 // Outside of a safepoint, the header could be changing (for example,
618 // another thread could be inflating a lock on this object).
619 if (ignore_mark_word) {
620 return true;
621 }
622 if (mark() != NULL) {
623 return true;
624 }
625 return !SafepointSynchronize::is_at_safepoint();
626 }
627
628
629 // used only for asserts
630 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
631 return this == NULL ? true : is_oop(ignore_mark_word);
632 }
633
634 #ifndef PRODUCT
635 // used only for asserts
636 inline bool oopDesc::is_unlocked_oop() const {
637 if (!Universe::heap()->is_in_reserved(this)) return false;
638 return mark()->is_unlocked();
639 }
640 #endif // PRODUCT
641
642 inline void oopDesc::follow_contents(void) {
643 assert (is_gc_marked(), "should be marked");
644 klass()->oop_follow_contents(this);
645 }
646
647 // Used by scavengers
648
649 inline bool oopDesc::is_forwarded() const {
650 // The extra heap check is needed since the obj might be locked, in which case the
651 // mark would point to a stack location and have the sentinel bit cleared
652 return mark()->is_marked();
653 }
654
655 // Used by scavengers
656 inline void oopDesc::forward_to(oop p) {
657 assert(check_obj_alignment(p),
658 "forwarding to something not aligned");
659 assert(Universe::heap()->is_in_reserved(p),
660 "forwarding to something not in heap");
661 markOop m = markOopDesc::encode_pointer_as_mark(p);
662 assert(m->decode_pointer() == p, "encoding must be reversable");
663 set_mark(m);
664 }
665
666 // Used by parallel scavengers
667 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
668 assert(check_obj_alignment(p),
669 "forwarding to something not aligned");
670 assert(Universe::heap()->is_in_reserved(p),
671 "forwarding to something not in heap");
672 markOop m = markOopDesc::encode_pointer_as_mark(p);
673 assert(m->decode_pointer() == p, "encoding must be reversable");
674 return cas_set_mark(m, compare) == compare;
675 }
676
677 // Note that the forwardee is not the same thing as the displaced_mark.
678 // The forwardee is used when copying during scavenge and mark-sweep.
679 // It does need to clear the low two locking- and GC-related bits.
680 inline oop oopDesc::forwardee() const {
681 return (oop) mark()->decode_pointer();
682 }
683
684 inline bool oopDesc::has_displaced_mark() const {
685 return mark()->has_displaced_mark_helper();
686 }
687
688 inline markOop oopDesc::displaced_mark() const {
689 return mark()->displaced_mark_helper();
690 }
691
692 inline void oopDesc::set_displaced_mark(markOop m) {
693 mark()->set_displaced_mark_helper(m);
694 }
695
696 // The following method needs to be MT safe.
697 inline uint oopDesc::age() const {
698 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
699 if (has_displaced_mark()) {
700 return displaced_mark()->age();
701 } else {
702 return mark()->age();
703 }
704 }
705
706 inline void oopDesc::incr_age() {
707 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
708 if (has_displaced_mark()) {
709 set_displaced_mark(displaced_mark()->incr_age());
710 } else {
711 set_mark(mark()->incr_age());
712 }
713 }
714
715
716 inline intptr_t oopDesc::identity_hash() {
717 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
718 // Note: The mark must be read into local variable to avoid concurrent updates.
719 markOop mrk = mark();
720 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
721 return mrk->hash();
722 } else if (mrk->is_marked()) {
723 return mrk->hash();
724 } else {
725 return slow_identity_hash();
726 }
727 }
728
729 inline int oopDesc::adjust_pointers() {
730 debug_only(int check_size = size());
731 int s = klass()->oop_adjust_pointers(this);
732 assert(s == check_size, "should be the same");
733 return s;
734 }
735
736 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
737 \
738 inline int oopDesc::oop_iterate(OopClosureType* blk) { \
739 SpecializationStats::record_call(); \
740 return klass()->oop_oop_iterate##nv_suffix(this, blk); \
741 } \
742 \
743 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
744 SpecializationStats::record_call(); \
745 return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \
746 }
747
748
749 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) {
750 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
751 // the do_oop calls, but turns off all other features in ExtendedOopClosure.
752 NoHeaderExtendedOopClosure cl(blk);
753 return oop_iterate(&cl);
754 }
755
756 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
757 NoHeaderExtendedOopClosure cl(blk);
758 return oop_iterate(&cl, mr);
759 }
760
761 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN)
762 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN)
763
764 #if INCLUDE_ALL_GCS
765 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
766 \
767 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
768 SpecializationStats::record_call(); \
769 return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
770 }
771
772 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN)
773 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN)
774 #endif // INCLUDE_ALL_GCS
775
776 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP