1 /*
2 * Copyright (c) 1997, 2012, 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 #ifdef TARGET_ARCH_x86
44 # include "bytes_x86.hpp"
45 #endif
46 #ifdef TARGET_ARCH_sparc
47 # include "bytes_sparc.hpp"
48 #endif
49 #ifdef TARGET_ARCH_zero
50 # include "bytes_zero.hpp"
51 #endif
52 #ifdef TARGET_ARCH_arm
53 # include "bytes_arm.hpp"
54 #endif
55 #ifdef TARGET_ARCH_ppc
56 # include "bytes_ppc.hpp"
57 #endif
58
59 // Implementation of all inlined member functions defined in oop.hpp
60 // We need a separate file to avoid circular references
61
62 inline void oopDesc::release_set_mark(markOop m) {
63 OrderAccess::release_store_ptr(&_mark, m);
64 }
65
66 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
67 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
68 }
69
70 inline Klass* oopDesc::klass() const {
71 if (UseCompressedKlassPointers) {
72 return decode_klass_not_null(_metadata._compressed_klass);
73 } else {
74 return _metadata._klass;
75 }
76 }
77
78 inline Klass* oopDesc::klass_or_null() const volatile {
79 // can be NULL in CMS
80 if (UseCompressedKlassPointers) {
81 return decode_klass(_metadata._compressed_klass);
82 } else {
83 return _metadata._klass;
84 }
85 }
86
87 inline int oopDesc::klass_gap_offset_in_bytes() {
88 assert(UseCompressedKlassPointers, "only applicable to compressed klass pointers");
89 return oopDesc::klass_offset_in_bytes() + sizeof(narrowOop);
90 }
91
92 inline Klass** oopDesc::klass_addr() {
93 // Only used internally and with CMS and will not work with
94 // UseCompressedOops
95 assert(!UseCompressedKlassPointers, "only supported with uncompressed klass pointers");
96 return (Klass**) &_metadata._klass;
97 }
98
99 inline narrowOop* oopDesc::compressed_klass_addr() {
100 assert(UseCompressedKlassPointers, "only called by compressed klass pointers");
101 return (narrowOop*) &_metadata._compressed_klass;
102 }
103
104 inline void oopDesc::set_klass(Klass* k) {
105 // since klasses are promoted no store check is needed
106 assert(Universe::is_bootstrapping() || k != NULL, "must be a real Klass*");
107 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass*");
108 if (UseCompressedKlassPointers) {
109 *compressed_klass_addr() = encode_klass_not_null(k);
110 } else {
111 *klass_addr() = k;
112 }
113 }
114
115 inline int oopDesc::klass_gap() const {
116 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
117 }
118
119 inline void oopDesc::set_klass_gap(int v) {
120 if (UseCompressedKlassPointers) {
121 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
122 }
123 }
124
125 inline void oopDesc::set_klass_to_list_ptr(oop k) {
126 // This is only to be used during GC, for from-space objects, so no
127 // barrier is needed.
128 if (UseCompressedKlassPointers) {
129 _metadata._compressed_klass = encode_heap_oop(k); // may be null (parnew overflow handling)
130 } else {
131 _metadata._klass = (Klass*)(address)k;
132 }
133 }
134
135 inline oop oopDesc::list_ptr_from_klass() {
136 // This is only to be used during GC, for from-space objects.
137 if (UseCompressedKlassPointers) {
138 return (oop)decode_heap_oop((oop)(address)_metadata._compressed_klass);
139 } else {
140 // Special case for GC
141 return (oop)(address)_metadata._klass;
142 }
143 }
144
145 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); }
146
147 inline bool oopDesc::is_a(Klass* k) const { return klass()->is_subtype_of(k); }
148
149 inline bool oopDesc::is_instance() const { return klass()->oop_is_instance(); }
150 inline bool oopDesc::is_instanceMirror() const { return klass()->oop_is_instanceMirror(); }
151 inline bool oopDesc::is_instanceRef() const { return klass()->oop_is_instanceRef(); }
152 inline bool oopDesc::is_array() const { return klass()->oop_is_array(); }
153 inline bool oopDesc::is_objArray() const { return klass()->oop_is_objArray(); }
154 inline bool oopDesc::is_typeArray() const { return klass()->oop_is_typeArray(); }
155
156 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; }
157
158 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
159 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
160 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); }
161 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); }
162 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); }
163 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); }
164 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); }
165 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); }
166 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); }
167 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
168 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
169
170
171 // Functions for getting and setting oops within instance objects.
172 // If the oops are compressed, the type passed to these overloaded functions
173 // is narrowOop. All functions are overloaded so they can be called by
174 // template functions without conditionals (the compiler instantiates via
175 // the right type and inlines the appopriate code).
176
177 inline bool oopDesc::is_null(oop obj) { return obj == NULL; }
178 inline bool oopDesc::is_null(Klass* obj) { return obj == NULL; }
179 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }
180
181 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
182 // offset from the heap base. Saving the check for null can save instructions
183 // in inner GC loops so these are separated.
184
185 inline bool check_obj_alignment(oop obj) {
186 return (intptr_t)obj % MinObjAlignmentInBytes == 0;
187 }
188 inline bool check_obj_alignment(Klass* obj) {
189 return (intptr_t)obj % MinObjAlignmentInBytes == 0;
190 }
191
192 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
193 assert(!is_null(v), "oop value can never be zero");
194 assert(check_obj_alignment(v), "Address not aligned");
195 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
196 address base = Universe::narrow_oop_base();
197 int shift = Universe::narrow_oop_shift();
198 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
199 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
200 uint64_t result = pd >> shift;
201 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
202 assert(decode_heap_oop(result) == v, "reversibility");
203 return (narrowOop)result;
204 }
205
206 inline narrowOop oopDesc::encode_heap_oop(oop v) {
207 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
208 }
209
210 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
211 assert(!is_null(v), "narrow oop value can never be zero");
212 address base = Universe::narrow_oop_base();
213 int shift = Universe::narrow_oop_shift();
214 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
215 assert(check_obj_alignment(result), err_msg("address not aligned: " PTR_FORMAT, (void*) result));
216 return result;
217 }
218
219 inline oop oopDesc::decode_heap_oop(narrowOop v) {
220 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
221 }
222
223 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
224 inline oop oopDesc::decode_heap_oop(oop v) { return v; }
225
226 // Encoding and decoding for klass field. It is copied code, but someday
227 // might not be the same as oop.
228
229 inline narrowOop oopDesc::encode_klass_not_null(Klass* v) {
230 assert(!is_null(v), "oop value can never be zero");
231 assert(check_obj_alignment(v), "Address not aligned");
232 address base = Universe::narrow_oop_base();
233 int shift = Universe::narrow_oop_shift();
234 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
235 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
236 uint64_t result = pd >> shift;
237 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow klass pointer overflow");
238 assert(decode_klass(result) == v, "reversibility");
239 return (narrowOop)result;
240 }
241
242 inline narrowOop oopDesc::encode_klass(Klass* v) {
243 return (is_null(v)) ? (narrowOop)0 : encode_klass_not_null(v);
244 }
245
246 inline Klass* oopDesc::decode_klass_not_null(narrowOop v) {
247 assert(!is_null(v), "narrow oop value can never be zero");
248 address base = Universe::narrow_oop_base();
249 int shift = Universe::narrow_oop_shift();
250 Klass* result = (Klass*)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
251 assert(check_obj_alignment(result), err_msg("address not aligned: " PTR_FORMAT, (void*) result));
252 return result;
253 }
254
255 inline Klass* oopDesc::decode_klass(narrowOop v) {
256 return is_null(v) ? (Klass*)NULL : decode_klass_not_null(v);
257 }
258
259 // Load an oop out of the Java heap as is without decoding.
260 // Called by GC to check for null before decoding.
261 inline oop oopDesc::load_heap_oop(oop* p) { return *p; }
262 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
263
264 // Load and decode an oop out of the Java heap into a wide oop.
265 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
266 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
267 return decode_heap_oop_not_null(*p);
268 }
269
270 // Load and decode an oop out of the heap accepting null
271 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
272 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
273 return decode_heap_oop(*p);
274 }
275
276 // Store already encoded heap oop into the heap.
277 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; }
278 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
279
280 // Encode and store a heap oop.
281 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
282 *p = encode_heap_oop_not_null(v);
283 }
284 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
285
286 // Encode and store a heap oop allowing for null.
287 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
288 *p = encode_heap_oop(v);
289 }
290 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
291
292 // Store heap oop as is for volatile fields.
293 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
294 OrderAccess::release_store_ptr(p, v);
295 }
296 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
297 narrowOop v) {
298 OrderAccess::release_store(p, v);
299 }
300
301 inline void oopDesc::release_encode_store_heap_oop_not_null(
302 volatile narrowOop* p, oop v) {
303 // heap oop is not pointer sized.
304 OrderAccess::release_store(p, encode_heap_oop_not_null(v));
305 }
306
307 inline void oopDesc::release_encode_store_heap_oop_not_null(
308 volatile oop* p, oop v) {
309 OrderAccess::release_store_ptr(p, v);
310 }
311
312 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
313 oop v) {
314 OrderAccess::release_store_ptr(p, v);
315 }
316 inline void oopDesc::release_encode_store_heap_oop(
317 volatile narrowOop* p, oop v) {
318 OrderAccess::release_store(p, encode_heap_oop(v));
319 }
320
321
322 // These functions are only used to exchange oop fields in instances,
323 // not headers.
324 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
325 if (UseCompressedOops) {
326 // encode exchange value from oop to T
327 narrowOop val = encode_heap_oop(exchange_value);
328 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
329 // decode old from T to oop
330 return decode_heap_oop(old);
331 } else {
332 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
333 }
334 }
335
336 // In order to put or get a field out of an instance, must first check
337 // if the field has been compressed and uncompress it.
338 inline oop oopDesc::obj_field(int offset) const {
339 return UseCompressedOops ?
340 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
341 load_decode_heap_oop(obj_field_addr<oop>(offset));
342 }
343 inline volatile oop oopDesc::obj_field_volatile(int offset) const {
344 volatile oop value = obj_field(offset);
345 OrderAccess::acquire();
346 return value;
347 }
348 inline void oopDesc::obj_field_put(int offset, oop value) {
349 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
350 oop_store(obj_field_addr<oop>(offset), value);
351 }
352
353 inline Metadata* oopDesc::metadata_field(int offset) const {
354 return *metadata_field_addr(offset);
355 }
356
357 inline void oopDesc::metadata_field_put(int offset, Metadata* value) {
358 *metadata_field_addr(offset) = value;
359 }
360
361 inline void oopDesc::obj_field_put_raw(int offset, oop value) {
362 UseCompressedOops ?
363 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
364 encode_store_heap_oop(obj_field_addr<oop>(offset), value);
365 }
366 inline void oopDesc::obj_field_put_volatile(int offset, oop value) {
367 OrderAccess::release();
368 obj_field_put(offset, value);
369 OrderAccess::fence();
370 }
371
372 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); }
373 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; }
374
375 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); }
376 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (jint) contents; }
377
378 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); }
379 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; }
380
381 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); }
382 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; }
383
384 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); }
385 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;}
386
387 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); }
388 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; }
389
390 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); }
391 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; }
392
393 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); }
394 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
395
396 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); }
397 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
398
399 inline oop oopDesc::obj_field_acquire(int offset) const {
400 return UseCompressedOops ?
401 decode_heap_oop((narrowOop)
402 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
403 : decode_heap_oop((oop)
404 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
405 }
406 inline void oopDesc::release_obj_field_put(int offset, oop value) {
407 UseCompressedOops ?
408 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
409 oop_store((volatile oop*) obj_field_addr<oop>(offset), value);
410 }
411
412 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); }
413 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); }
414
415 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); }
416 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), contents); }
417
418 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); }
419 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); }
420
421 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); }
422 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); }
423
424 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
425 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); }
426
427 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); }
428 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); }
429
430 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); }
431 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); }
432
433 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); }
434 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
435
436 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
437 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
438
439 inline int oopDesc::size_given_klass(Klass* klass) {
440 int lh = klass->layout_helper();
441 int s;
442
443 // lh is now a value computed at class initialization that may hint
444 // at the size. For instances, this is positive and equal to the
445 // size. For arrays, this is negative and provides log2 of the
446 // array element size. For other oops, it is zero and thus requires
447 // a virtual call.
448 //
449 // We go to all this trouble because the size computation is at the
450 // heart of phase 2 of mark-compaction, and called for every object,
451 // alive or dead. So the speed here is equal in importance to the
452 // speed of allocation.
453
454 if (lh > Klass::_lh_neutral_value) {
455 if (!Klass::layout_helper_needs_slow_path(lh)) {
456 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
457 } else {
458 s = klass->oop_size(this);
459 }
460 } else if (lh <= Klass::_lh_neutral_value) {
461 // The most common case is instances; fall through if so.
462 if (lh < Klass::_lh_neutral_value) {
463 // Second most common case is arrays. We have to fetch the
464 // length of the array, shift (multiply) it appropriately,
465 // up to wordSize, add the header, and align to object size.
466 size_t size_in_bytes;
467 #ifdef _M_IA64
468 // The Windows Itanium Aug 2002 SDK hoists this load above
469 // the check for s < 0. An oop at the end of the heap will
470 // cause an access violation if this load is performed on a non
471 // array oop. Making the reference volatile prohibits this.
472 // (%%% please explain by what magic the length is actually fetched!)
473 volatile int *array_length;
474 array_length = (volatile int *)( (intptr_t)this +
475 arrayOopDesc::length_offset_in_bytes() );
476 assert(array_length > 0, "Integer arithmetic problem somewhere");
477 // Put into size_t to avoid overflow.
478 size_in_bytes = (size_t) array_length;
479 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
480 #else
481 size_t array_length = (size_t) ((arrayOop)this)->length();
482 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
483 #endif
484 size_in_bytes += Klass::layout_helper_header_size(lh);
485
486 // This code could be simplified, but by keeping array_header_in_bytes
487 // in units of bytes and doing it this way we can round up just once,
488 // skipping the intermediate round to HeapWordSize. Cast the result
489 // of round_to to size_t to guarantee unsigned division == right shift.
490 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
491 HeapWordSize);
492
493 // UseParNewGC, UseParallelGC and UseG1GC can change the length field
494 // of an "old copy" of an object array in the young gen so it indicates
495 // the grey portion of an already copied array. This will cause the first
496 // disjunct below to fail if the two comparands are computed across such
497 // a concurrent change.
498 // UseParNewGC also runs with promotion labs (which look like int
499 // filler arrays) which are subject to changing their declared size
500 // when finally retiring a PLAB; this also can cause the first disjunct
501 // to fail for another worker thread that is concurrently walking the block
502 // offset table. Both these invariant failures are benign for their
503 // current uses; we relax the assertion checking to cover these two cases below:
504 // is_objArray() && is_forwarded() // covers first scenario above
505 // || is_typeArray() // covers second scenario above
506 // If and when UseParallelGC uses the same obj array oop stealing/chunking
507 // technique, we will need to suitably modify the assertion.
508 assert((s == klass->oop_size(this)) ||
509 (Universe::heap()->is_gc_active() &&
510 ((is_typeArray() && UseParNewGC) ||
511 (is_objArray() && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))),
512 "wrong array object size");
513 } else {
514 // Must be zero, so bite the bullet and take the virtual call.
515 s = klass->oop_size(this);
516 }
517 }
518
519 assert(s % MinObjAlignment == 0, "alignment check");
520 assert(s > 0, "Bad size calculated");
521 return s;
522 }
523
524
525 inline int oopDesc::size() {
526 return size_given_klass(klass());
527 }
528
529 inline void update_barrier_set(void* p, oop v) {
530 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
531 oopDesc::bs()->write_ref_field(p, v);
532 }
533
534 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
535 oopDesc::bs()->write_ref_field_pre(p, v);
536 }
537
538 template <class T> inline void oop_store(T* p, oop v) {
539 if (always_do_update_barrier) {
540 oop_store((volatile T*)p, v);
541 } else {
542 update_barrier_set_pre(p, v);
543 oopDesc::encode_store_heap_oop(p, v);
544 update_barrier_set((void*)p, v); // cast away type
545 }
546 }
547
548 template <class T> inline void oop_store(volatile T* p, oop v) {
549 update_barrier_set_pre((T*)p, v); // cast away volatile
550 // Used by release_obj_field_put, so use release_store_ptr.
551 oopDesc::release_encode_store_heap_oop(p, v);
552 update_barrier_set((void*)p, v); // cast away type
553 }
554
555 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
556 // (without having to remember the function name this calls).
557 inline void oop_store_raw(HeapWord* addr, oop value) {
558 if (UseCompressedOops) {
559 oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
560 } else {
561 oopDesc::encode_store_heap_oop((oop*)addr, value);
562 }
563 }
564
565 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
566 volatile HeapWord *dest,
567 oop compare_value,
568 bool prebarrier) {
569 if (UseCompressedOops) {
570 if (prebarrier) {
571 update_barrier_set_pre((narrowOop*)dest, exchange_value);
572 }
573 // encode exchange and compare value from oop to T
574 narrowOop val = encode_heap_oop(exchange_value);
575 narrowOop cmp = encode_heap_oop(compare_value);
576
577 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
578 // decode old from T to oop
579 return decode_heap_oop(old);
580 } else {
581 if (prebarrier) {
582 update_barrier_set_pre((oop*)dest, exchange_value);
583 }
584 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
585 }
586 }
587
588 // Used only for markSweep, scavenging
589 inline bool oopDesc::is_gc_marked() const {
590 return mark()->is_marked();
591 }
592
593 inline bool oopDesc::is_locked() const {
594 return mark()->is_locked();
595 }
596
597 inline bool oopDesc::is_unlocked() const {
598 return mark()->is_unlocked();
599 }
600
601 inline bool oopDesc::has_bias_pattern() const {
602 return mark()->has_bias_pattern();
603 }
604
605
606 // used only for asserts
607 inline bool oopDesc::is_oop(bool ignore_mark_word) const {
608 oop obj = (oop) this;
609 if (!check_obj_alignment(obj)) return false;
610 if (!Universe::heap()->is_in_reserved(obj)) return false;
611 // obj is aligned and accessible in heap
612 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false;
613
614 // Header verification: the mark is typically non-NULL. If we're
615 // at a safepoint, it must not be null.
616 // Outside of a safepoint, the header could be changing (for example,
617 // another thread could be inflating a lock on this object).
618 if (ignore_mark_word) {
619 return true;
620 }
621 if (mark() != NULL) {
622 return true;
623 }
624 return !SafepointSynchronize::is_at_safepoint();
625 }
626
627
628 // used only for asserts
629 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
630 return this == NULL ? true : is_oop(ignore_mark_word);
631 }
632
633 #ifndef PRODUCT
634 // used only for asserts
635 inline bool oopDesc::is_unlocked_oop() const {
636 if (!Universe::heap()->is_in_reserved(this)) return false;
637 return mark()->is_unlocked();
638 }
639 #endif // PRODUCT
640
641 inline void oopDesc::follow_contents(void) {
642 assert (is_gc_marked(), "should be marked");
643 klass()->oop_follow_contents(this);
644 }
645
646 // Used by scavengers
647
648 inline bool oopDesc::is_forwarded() const {
649 // The extra heap check is needed since the obj might be locked, in which case the
650 // mark would point to a stack location and have the sentinel bit cleared
651 return mark()->is_marked();
652 }
653
654 // Used by scavengers
655 inline void oopDesc::forward_to(oop p) {
656 assert(check_obj_alignment(p),
657 "forwarding to something not aligned");
658 assert(Universe::heap()->is_in_reserved(p),
659 "forwarding to something not in heap");
660 markOop m = markOopDesc::encode_pointer_as_mark(p);
661 assert(m->decode_pointer() == p, "encoding must be reversable");
662 set_mark(m);
663 }
664
665 // Used by parallel scavengers
666 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
667 assert(check_obj_alignment(p),
668 "forwarding to something not aligned");
669 assert(Universe::heap()->is_in_reserved(p),
670 "forwarding to something not in heap");
671 markOop m = markOopDesc::encode_pointer_as_mark(p);
672 assert(m->decode_pointer() == p, "encoding must be reversable");
673 return cas_set_mark(m, compare) == compare;
674 }
675
676 // Note that the forwardee is not the same thing as the displaced_mark.
677 // The forwardee is used when copying during scavenge and mark-sweep.
678 // It does need to clear the low two locking- and GC-related bits.
679 inline oop oopDesc::forwardee() const {
680 return (oop) mark()->decode_pointer();
681 }
682
683 inline bool oopDesc::has_displaced_mark() const {
684 return mark()->has_displaced_mark_helper();
685 }
686
687 inline markOop oopDesc::displaced_mark() const {
688 return mark()->displaced_mark_helper();
689 }
690
691 inline void oopDesc::set_displaced_mark(markOop m) {
692 mark()->set_displaced_mark_helper(m);
693 }
694
695 // The following method needs to be MT safe.
696 inline int oopDesc::age() const {
697 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
698 if (has_displaced_mark()) {
699 return displaced_mark()->age();
700 } else {
701 return mark()->age();
702 }
703 }
704
705 inline void oopDesc::incr_age() {
706 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
707 if (has_displaced_mark()) {
708 set_displaced_mark(displaced_mark()->incr_age());
709 } else {
710 set_mark(mark()->incr_age());
711 }
712 }
713
714
715 inline intptr_t oopDesc::identity_hash() {
716 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
717 // Note: The mark must be read into local variable to avoid concurrent updates.
718 markOop mrk = mark();
719 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
720 return mrk->hash();
721 } else if (mrk->is_marked()) {
722 return mrk->hash();
723 } else {
724 return slow_identity_hash();
725 }
726 }
727
728 inline int oopDesc::adjust_pointers() {
729 debug_only(int check_size = size());
730 int s = klass()->oop_adjust_pointers(this);
731 assert(s == check_size, "should be the same");
732 return s;
733 }
734
735 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
736 \
737 inline int oopDesc::oop_iterate(OopClosureType* blk) { \
738 SpecializationStats::record_call(); \
739 return klass()->oop_oop_iterate##nv_suffix(this, blk); \
740 } \
741 \
742 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
743 SpecializationStats::record_call(); \
744 return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \
745 }
746
747
748 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) {
749 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
750 // the do_oop calls, but turns off all other features in ExtendedOopClosure.
751 NoHeaderExtendedOopClosure cl(blk);
752 return oop_iterate(&cl);
753 }
754
755 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
756 NoHeaderExtendedOopClosure cl(blk);
757 return oop_iterate(&cl, mr);
758 }
759
760 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN)
761 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN)
762
763 #ifndef SERIALGC
764 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
765 \
766 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
767 SpecializationStats::record_call(); \
768 return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
769 }
770
771 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN)
772 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN)
773 #endif // !SERIALGC
774
775 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP