1 /*
2 * Copyright (c) 1997, 2016, 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.
22 *
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_aarch64
49 # include "bytes_aarch64.hpp"
50 #endif
51 #ifdef TARGET_ARCH_sparc
52 # include "bytes_sparc.hpp"
53 #endif
54 #ifdef TARGET_ARCH_zero
55 # include "bytes_zero.hpp"
56 #endif
57 #ifdef TARGET_ARCH_arm
58 # include "bytes_arm.hpp"
59 #endif
60 #ifdef TARGET_ARCH_ppc
61 # include "bytes_ppc.hpp"
62 #endif
63
64 // Implementation of all inlined member functions defined in oop.hpp
65 // We need a separate file to avoid circular references
66
67 inline void oopDesc::release_set_mark(markOop m) {
68 OrderAccess::release_store_ptr(&_mark, m);
69 }
70
71 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
72 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
73 }
74
75 inline Klass* oopDesc::klass() const {
76 if (UseCompressedClassPointers) {
77 return Klass::decode_klass_not_null(_metadata._compressed_klass);
78 } else {
79 return _metadata._klass;
80 }
81 }
82
83 inline Klass* oopDesc::klass_or_null() const volatile {
84 if (UseCompressedClassPointers) {
85 return Klass::decode_klass(_metadata._compressed_klass);
86 } else {
87 return _metadata._klass;
88 }
89 }
90
91 inline Klass* oopDesc::klass_or_null_acquire() const volatile {
92 if (UseCompressedClassPointers) {
93 // Workaround for non-const load_acquire parameter.
94 const volatile narrowKlass* addr = &_metadata._compressed_klass;
95 volatile narrowKlass* xaddr = const_cast<volatile narrowKlass*>(addr);
96 return Klass::decode_klass(OrderAccess::load_acquire(xaddr));
97 } else {
98 return (Klass*)OrderAccess::load_ptr_acquire(&_metadata._klass);
99 }
100 }
101
102 inline int oopDesc::klass_gap_offset_in_bytes() {
103 assert(UseCompressedClassPointers, "only applicable to compressed klass pointers");
104 return oopDesc::klass_offset_in_bytes() + sizeof(narrowKlass);
105 }
106
107 inline Klass** oopDesc::klass_addr() {
108 // Only used internally and with CMS and will not work with
109 // UseCompressedOops
110 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers");
111 return (Klass**) &_metadata._klass;
112 }
113
114 inline narrowKlass* oopDesc::compressed_klass_addr() {
115 assert(UseCompressedClassPointers, "only called by compressed klass pointers");
116 return &_metadata._compressed_klass;
117 }
118
119 #define CHECK_SET_KLASS(k) \
120 do { \
121 assert(Universe::is_bootstrapping() || k != NULL, "NULL Klass"); \
122 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass"); \
123 } while (0)
124
125 inline void oopDesc::set_klass(Klass* k) {
126 CHECK_SET_KLASS(k);
127 if (UseCompressedClassPointers) {
128 *compressed_klass_addr() = Klass::encode_klass_not_null(k);
129 } else {
130 *klass_addr() = k;
131 }
132 }
133
134 inline void oopDesc::release_set_klass(Klass* k) {
135 CHECK_SET_KLASS(k);
136 if (UseCompressedClassPointers) {
137 OrderAccess::release_store(compressed_klass_addr(),
138 Klass::encode_klass_not_null(k));
139 } else {
140 OrderAccess::release_store_ptr(klass_addr(), k);
141 }
142 }
143
144 #undef CHECK_SET_KLASS
145
146 inline int oopDesc::klass_gap() const {
147 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
148 }
149
150 inline void oopDesc::set_klass_gap(int v) {
151 if (UseCompressedClassPointers) {
152 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
153 }
154 }
155
156 inline void oopDesc::set_klass_to_list_ptr(oop k) {
157 // This is only to be used during GC, for from-space objects, so no
158 // barrier is needed.
159 if (UseCompressedClassPointers) {
160 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling)
161 } else {
162 _metadata._klass = (Klass*)(address)k;
163 }
164 }
165
166 inline oop oopDesc::list_ptr_from_klass() {
167 // This is only to be used during GC, for from-space objects.
168 if (UseCompressedClassPointers) {
169 return decode_heap_oop((narrowOop)_metadata._compressed_klass);
170 } else {
171 // Special case for GC
172 return (oop)(address)_metadata._klass;
173 }
174 }
175
176 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); }
177
178 inline bool oopDesc::is_a(Klass* k) const { return klass()->is_subtype_of(k); }
179
180 inline bool oopDesc::is_instance() const { return klass()->oop_is_instance(); }
181 inline bool oopDesc::is_instanceClassLoader() const { return klass()->oop_is_instanceClassLoader(); }
182 inline bool oopDesc::is_instanceMirror() const { return klass()->oop_is_instanceMirror(); }
183 inline bool oopDesc::is_instanceRef() const { return klass()->oop_is_instanceRef(); }
184 inline bool oopDesc::is_array() const { return klass()->oop_is_array(); }
185 inline bool oopDesc::is_objArray() const { return klass()->oop_is_objArray(); }
186 inline bool oopDesc::is_typeArray() const { return klass()->oop_is_typeArray(); }
187
188 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; }
189
190 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
191 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
192 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); }
193 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); }
194 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); }
195 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); }
196 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); }
197 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); }
198 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); }
199 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
200 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
201
202
203 // Functions for getting and setting oops within instance objects.
204 // If the oops are compressed, the type passed to these overloaded functions
205 // is narrowOop. All functions are overloaded so they can be called by
206 // template functions without conditionals (the compiler instantiates via
207 // the right type and inlines the appopriate code).
208
209 inline bool oopDesc::is_null(oop obj) { return obj == NULL; }
210 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }
211
212 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
213 // offset from the heap base. Saving the check for null can save instructions
214 // in inner GC loops so these are separated.
215
216 inline bool check_obj_alignment(oop obj) {
217 return cast_from_oop<intptr_t>(obj) % MinObjAlignmentInBytes == 0;
218 }
219
220 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
221 assert(!is_null(v), "oop value can never be zero");
222 assert(check_obj_alignment(v), "Address not aligned");
223 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
224 address base = Universe::narrow_oop_base();
225 int shift = Universe::narrow_oop_shift();
226 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
227 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
228 uint64_t result = pd >> shift;
229 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
230 assert(decode_heap_oop(result) == v, "reversibility");
231 return (narrowOop)result;
232 }
233
234 inline narrowOop oopDesc::encode_heap_oop(oop v) {
235 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
236 }
237
238 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
239 assert(!is_null(v), "narrow oop value can never be zero");
240 address base = Universe::narrow_oop_base();
241 int shift = Universe::narrow_oop_shift();
242 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
243 assert(check_obj_alignment(result), err_msg("address not aligned: " INTPTR_FORMAT, p2i((void*) result)));
244 return result;
245 }
246
247 inline oop oopDesc::decode_heap_oop(narrowOop v) {
248 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
249 }
250
251 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
252 inline oop oopDesc::decode_heap_oop(oop v) { return v; }
253
254 // Load an oop out of the Java heap as is without decoding.
255 // Called by GC to check for null before decoding.
256 inline oop oopDesc::load_heap_oop(oop* p) { return *p; }
257 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
258
259 // Load and decode an oop out of the Java heap into a wide oop.
260 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
261 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
262 return decode_heap_oop_not_null(*p);
263 }
264
265 // Load and decode an oop out of the heap accepting null
266 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
267 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
268 return decode_heap_oop(*p);
269 }
270
271 // Store already encoded heap oop into the heap.
272 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; }
273 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
274
275 // Encode and store a heap oop.
276 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
277 *p = encode_heap_oop_not_null(v);
278 }
279 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
280
281 // Encode and store a heap oop allowing for null.
282 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
283 *p = encode_heap_oop(v);
284 }
285 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
286
287 // Store heap oop as is for volatile fields.
288 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
289 OrderAccess::release_store_ptr(p, v);
290 }
291 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
292 narrowOop v) {
293 OrderAccess::release_store(p, v);
294 }
295
296 inline void oopDesc::release_encode_store_heap_oop_not_null(
297 volatile narrowOop* p, oop v) {
298 // heap oop is not pointer sized.
299 OrderAccess::release_store(p, encode_heap_oop_not_null(v));
300 }
301
302 inline void oopDesc::release_encode_store_heap_oop_not_null(
303 volatile oop* p, oop v) {
304 OrderAccess::release_store_ptr(p, v);
305 }
306
307 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
308 oop v) {
309 OrderAccess::release_store_ptr(p, v);
310 }
311 inline void oopDesc::release_encode_store_heap_oop(
312 volatile narrowOop* p, oop v) {
313 OrderAccess::release_store(p, encode_heap_oop(v));
314 }
315
316
317 // These functions are only used to exchange oop fields in instances,
318 // not headers.
319 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
320 if (UseCompressedOops) {
321 // encode exchange value from oop to T
322 narrowOop val = encode_heap_oop(exchange_value);
323 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
324 // decode old from T to oop
325 return decode_heap_oop(old);
326 } else {
327 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
328 }
329 }
330
331 // In order to put or get a field out of an instance, must first check
332 // if the field has been compressed and uncompress it.
333 inline oop oopDesc::obj_field(int offset) const {
334 return UseCompressedOops ?
335 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
336 load_decode_heap_oop(obj_field_addr<oop>(offset));
337 }
338 inline volatile oop oopDesc::obj_field_volatile(int offset) const {
339 volatile oop value = obj_field(offset);
340 OrderAccess::acquire();
341 return value;
342 }
343 inline void oopDesc::obj_field_put(int offset, oop value) {
344 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
345 oop_store(obj_field_addr<oop>(offset), value);
346 }
347
348 inline Metadata* oopDesc::metadata_field(int offset) const {
349 return *metadata_field_addr(offset);
350 }
351
352 inline void oopDesc::metadata_field_put(int offset, Metadata* value) {
353 *metadata_field_addr(offset) = value;
354 }
355
356 inline void oopDesc::obj_field_put_raw(int offset, oop value) {
357 UseCompressedOops ?
358 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
359 encode_store_heap_oop(obj_field_addr<oop>(offset), value);
360 }
361 inline void oopDesc::obj_field_put_volatile(int offset, oop value) {
362 OrderAccess::release();
363 obj_field_put(offset, value);
364 OrderAccess::fence();
365 }
366
367 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); }
368 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; }
369
370 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); }
371 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (( (jint) contents) & 1); }
372
373 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); }
374 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; }
375
376 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); }
377 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; }
378
379 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); }
380 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;}
381
382 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); }
383 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; }
384
385 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); }
386 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; }
387
388 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); }
389 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
390
391 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); }
392 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
393
394 inline oop oopDesc::obj_field_acquire(int offset) const {
395 return UseCompressedOops ?
396 decode_heap_oop((narrowOop)
397 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
398 : decode_heap_oop((oop)
399 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
400 }
401 inline void oopDesc::release_obj_field_put(int offset, oop value) {
402 UseCompressedOops ?
403 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
404 oop_store((volatile oop*) obj_field_addr<oop>(offset), value);
405 }
406
407 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); }
408 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); }
409
410 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); }
411 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), (contents & 1)); }
412
413 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); }
414 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); }
415
416 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); }
417 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); }
418
419 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
420 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); }
421
422 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); }
423 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); }
424
425 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); }
426 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); }
427
428 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); }
429 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
430
431 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
432 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
433
434 inline int oopDesc::size_given_klass(Klass* klass) {
435 int lh = klass->layout_helper();
436 int s;
437
438 // lh is now a value computed at class initialization that may hint
439 // at the size. For instances, this is positive and equal to the
440 // size. For arrays, this is negative and provides log2 of the
441 // array element size. For other oops, it is zero and thus requires
442 // a virtual call.
443 //
444 // We go to all this trouble because the size computation is at the
445 // heart of phase 2 of mark-compaction, and called for every object,
446 // alive or dead. So the speed here is equal in importance to the
447 // speed of allocation.
448
449 if (lh > Klass::_lh_neutral_value) {
450 if (!Klass::layout_helper_needs_slow_path(lh)) {
451 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
452 } else {
453 s = klass->oop_size(this);
454 }
455 } else if (lh <= Klass::_lh_neutral_value) {
456 // The most common case is instances; fall through if so.
457 if (lh < Klass::_lh_neutral_value) {
458 // Second most common case is arrays. We have to fetch the
459 // length of the array, shift (multiply) it appropriately,
460 // up to wordSize, add the header, and align to object size.
461 size_t size_in_bytes;
462 #ifdef _M_IA64
463 // The Windows Itanium Aug 2002 SDK hoists this load above
464 // the check for s < 0. An oop at the end of the heap will
465 // cause an access violation if this load is performed on a non
466 // array oop. Making the reference volatile prohibits this.
467 // (%%% please explain by what magic the length is actually fetched!)
468 volatile int *array_length;
469 array_length = (volatile int *)( (intptr_t)this +
470 arrayOopDesc::length_offset_in_bytes() );
471 assert(array_length > 0, "Integer arithmetic problem somewhere");
472 // Put into size_t to avoid overflow.
473 size_in_bytes = (size_t) array_length;
474 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
475 #else
476 size_t array_length = (size_t) ((arrayOop)this)->length();
477 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
478 #endif
479 size_in_bytes += Klass::layout_helper_header_size(lh);
480
481 // This code could be simplified, but by keeping array_header_in_bytes
482 // in units of bytes and doing it this way we can round up just once,
483 // skipping the intermediate round to HeapWordSize. Cast the result
484 // of round_to to size_t to guarantee unsigned division == right shift.
485 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
486 HeapWordSize);
487
488 // UseParNewGC, UseParallelGC and UseG1GC can change the length field
489 // of an "old copy" of an object array in the young gen so it indicates
490 // the grey portion of an already copied array. This will cause the first
491 // disjunct below to fail if the two comparands are computed across such
492 // a concurrent change.
493 // UseParNewGC also runs with promotion labs (which look like int
494 // filler arrays) which are subject to changing their declared size
495 // when finally retiring a PLAB; this also can cause the first disjunct
496 // to fail for another worker thread that is concurrently walking the block
497 // offset table. Both these invariant failures are benign for their
498 // current uses; we relax the assertion checking to cover these two cases below:
499 // is_objArray() && is_forwarded() // covers first scenario above
500 // || is_typeArray() // covers second scenario above
501 // If and when UseParallelGC uses the same obj array oop stealing/chunking
502 // technique, we will need to suitably modify the assertion.
503 assert((s == klass->oop_size(this)) ||
504 (Universe::heap()->is_gc_active() &&
505 ((is_typeArray() && UseParNewGC) ||
506 (is_objArray() && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))),
507 "wrong array object size");
508 } else {
509 // Must be zero, so bite the bullet and take the virtual call.
510 s = klass->oop_size(this);
511 }
512 }
513
514 assert(s % MinObjAlignment == 0, "alignment check");
515 assert(s > 0, "Bad size calculated");
516 return s;
517 }
518
519
520 inline int oopDesc::size() {
521 return size_given_klass(klass());
522 }
523
524 inline void update_barrier_set(void* p, oop v, bool release = false) {
525 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
526 oopDesc::bs()->write_ref_field(p, v, release);
527 }
528
529 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
530 oopDesc::bs()->write_ref_field_pre(p, v);
531 }
532
533 template <class T> inline void oop_store(T* p, oop v) {
534 if (always_do_update_barrier) {
535 oop_store((volatile T*)p, v);
536 } else {
537 update_barrier_set_pre(p, v);
538 oopDesc::encode_store_heap_oop(p, v);
539 // always_do_update_barrier == false =>
540 // Either we are at a safepoint (in GC) or CMS is not used. In both
541 // cases it's unnecessary to mark the card as dirty with release sematics.
542 update_barrier_set((void*)p, v, false /* release */); // cast away type
543 }
544 }
545
546 template <class T> inline void oop_store(volatile T* p, oop v) {
547 update_barrier_set_pre((T*)p, v); // cast away volatile
548 // Used by release_obj_field_put, so use release_store_ptr.
549 oopDesc::release_encode_store_heap_oop(p, v);
550 // When using CMS we must mark the card corresponding to p as dirty
551 // with release sematics to prevent that CMS sees the dirty card but
552 // not the new value v at p due to reordering of the two
553 // stores. Note that CMS has a concurrent precleaning phase, where
554 // it reads the card table while the Java threads are running.
555 update_barrier_set((void*)p, v, true /* release */); // cast away type
556 }
557
558 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
559 // (without having to remember the function name this calls).
560 inline void oop_store_raw(HeapWord* addr, oop value) {
561 if (UseCompressedOops) {
562 oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
563 } else {
564 oopDesc::encode_store_heap_oop((oop*)addr, value);
565 }
566 }
567
568 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
569 volatile HeapWord *dest,
570 oop compare_value,
571 bool prebarrier) {
572 if (UseCompressedOops) {
573 if (prebarrier) {
574 update_barrier_set_pre((narrowOop*)dest, exchange_value);
575 }
576 // encode exchange and compare value from oop to T
577 narrowOop val = encode_heap_oop(exchange_value);
578 narrowOop cmp = encode_heap_oop(compare_value);
579
580 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
581 // decode old from T to oop
582 return decode_heap_oop(old);
583 } else {
584 if (prebarrier) {
585 update_barrier_set_pre((oop*)dest, exchange_value);
586 }
587 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
588 }
589 }
590
591 // Used only for markSweep, scavenging
592 inline bool oopDesc::is_gc_marked() const {
593 return mark()->is_marked();
594 }
595
596 inline bool oopDesc::is_locked() const {
597 return mark()->is_locked();
598 }
599
600 inline bool oopDesc::is_unlocked() const {
601 return mark()->is_unlocked();
602 }
603
604 inline bool oopDesc::has_bias_pattern() const {
605 return mark()->has_bias_pattern();
606 }
607
608
609 // used only for asserts
610 inline bool oopDesc::is_oop(bool ignore_mark_word) const {
611 oop obj = (oop) this;
612 if (!check_obj_alignment(obj)) return false;
613 if (!Universe::heap()->is_in_reserved(obj)) return false;
614 // obj is aligned and accessible in heap
615 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false;
616
617 // Header verification: the mark is typically non-NULL. If we're
618 // at a safepoint, it must not be null.
619 // Outside of a safepoint, the header could be changing (for example,
620 // another thread could be inflating a lock on this object).
621 if (ignore_mark_word) {
622 return true;
623 }
624 if (mark() != NULL) {
625 return true;
626 }
627 return !SafepointSynchronize::is_at_safepoint();
628 }
629
630
631 // used only for asserts
632 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
633 return this == NULL ? true : is_oop(ignore_mark_word);
634 }
635
636 #ifndef PRODUCT
637 // used only for asserts
638 inline bool oopDesc::is_unlocked_oop() const {
639 if (!Universe::heap()->is_in_reserved(this)) return false;
640 return mark()->is_unlocked();
641 }
642 #endif // PRODUCT
643
644 inline void oopDesc::follow_contents(void) {
645 assert (is_gc_marked(), "should be marked");
646 klass()->oop_follow_contents(this);
647 }
648
649 // Used by scavengers
650
651 inline bool oopDesc::is_forwarded() const {
652 // The extra heap check is needed since the obj might be locked, in which case the
653 // mark would point to a stack location and have the sentinel bit cleared
654 return mark()->is_marked();
655 }
656
657 // Used by scavengers
658 inline void oopDesc::forward_to(oop p) {
659 assert(check_obj_alignment(p),
660 "forwarding to something not aligned");
661 assert(Universe::heap()->is_in_reserved(p),
662 "forwarding to something not in heap");
663 markOop m = markOopDesc::encode_pointer_as_mark(p);
664 assert(m->decode_pointer() == p, "encoding must be reversable");
665 set_mark(m);
666 }
667
668 // Used by parallel scavengers
669 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
670 assert(check_obj_alignment(p),
671 "forwarding to something not aligned");
672 assert(Universe::heap()->is_in_reserved(p),
673 "forwarding to something not in heap");
674 markOop m = markOopDesc::encode_pointer_as_mark(p);
675 assert(m->decode_pointer() == p, "encoding must be reversable");
676 return cas_set_mark(m, compare) == compare;
677 }
678
679 // Note that the forwardee is not the same thing as the displaced_mark.
680 // The forwardee is used when copying during scavenge and mark-sweep.
681 // It does need to clear the low two locking- and GC-related bits.
682 inline oop oopDesc::forwardee() const {
683 return (oop) mark()->decode_pointer();
684 }
685
686 inline bool oopDesc::has_displaced_mark() const {
687 return mark()->has_displaced_mark_helper();
688 }
689
690 inline markOop oopDesc::displaced_mark() const {
691 return mark()->displaced_mark_helper();
692 }
693
694 inline void oopDesc::set_displaced_mark(markOop m) {
695 mark()->set_displaced_mark_helper(m);
696 }
697
698 // The following method needs to be MT safe.
699 inline uint oopDesc::age() const {
700 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
701 if (has_displaced_mark()) {
702 return displaced_mark()->age();
703 } else {
704 return mark()->age();
705 }
706 }
707
708 inline void oopDesc::incr_age() {
709 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
710 if (has_displaced_mark()) {
711 set_displaced_mark(displaced_mark()->incr_age());
712 } else {
713 set_mark(mark()->incr_age());
714 }
715 }
716
717
718 inline intptr_t oopDesc::identity_hash() {
719 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
720 // Note: The mark must be read into local variable to avoid concurrent updates.
721 markOop mrk = mark();
722 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
723 return mrk->hash();
724 } else if (mrk->is_marked()) {
725 return mrk->hash();
726 } else {
727 return slow_identity_hash();
728 }
729 }
730
731 inline int oopDesc::adjust_pointers() {
732 debug_only(int check_size = size());
733 int s = klass()->oop_adjust_pointers(this);
734 assert(s == check_size, "should be the same");
735 return s;
736 }
737
738 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
739 \
740 inline int oopDesc::oop_iterate(OopClosureType* blk) { \
741 SpecializationStats::record_call(); \
742 return klass()->oop_oop_iterate##nv_suffix(this, blk); \
743 } \
744 \
745 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
746 SpecializationStats::record_call(); \
747 return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \
748 }
749
750
751 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) {
752 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
753 // the do_oop calls, but turns off all other features in ExtendedOopClosure.
754 NoHeaderExtendedOopClosure cl(blk);
755 return oop_iterate(&cl);
756 }
757
758 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
759 NoHeaderExtendedOopClosure cl(blk);
760 return oop_iterate(&cl, mr);
761 }
762
763 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN)
764 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN)
765
766 #if INCLUDE_ALL_GCS
767 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
768 \
769 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
770 SpecializationStats::record_call(); \
771 return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
772 }
773
774 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN)
775 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN)
776 #endif // INCLUDE_ALL_GCS
777
778 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP