1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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/iterator.inline.hpp"
32 #include "memory/barrierSet.inline.hpp"
33 #include "memory/cardTableModRefBS.hpp"
34 #include "memory/genCollectedHeap.hpp"
35 #include "memory/generation.hpp"
36 #include "memory/specialized_oop_closures.inline.hpp"
37 #include "oops/instanceMirrorKlass.inline.hpp"
38 #include "oops/instanceRefKlass.inline.hpp"
39 #include "oops/instanceClassLoaderKlass.inline.hpp"
40 #include "oops/arrayKlass.hpp"
41 #include "oops/arrayOop.hpp"
42 #include "oops/klass.inline.hpp"
43 #include "oops/markOop.inline.hpp"
44 #include "oops/oop.hpp"
45 #include "runtime/atomic.inline.hpp"
46 #include "runtime/orderAccess.inline.hpp"
47 #include "runtime/os.hpp"
48 #include "utilities/macros.hpp"
49
50 // Implementation of all inlined member functions defined in oop.hpp
51 // We need a separate file to avoid circular references
52
53 inline void oopDesc::release_set_mark(markOop m) {
54 OrderAccess::release_store_ptr(&_mark, m);
55 }
56
57 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
58 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
59 }
60
61 inline Klass* oopDesc::klass() const {
62 if (UseCompressedClassPointers) {
63 return Klass::decode_klass_not_null(_metadata._compressed_klass);
64 } else {
65 return _metadata._klass;
66 }
67 }
68
69 inline Klass* oopDesc::klass_or_null() const volatile {
70 // can be NULL in CMS
71 if (UseCompressedClassPointers) {
72 return Klass::decode_klass(_metadata._compressed_klass);
73 } else {
74 return _metadata._klass;
75 }
76 }
77
78 inline int oopDesc::klass_gap_offset_in_bytes() {
79 assert(UseCompressedClassPointers, "only applicable to compressed klass pointers");
80 return oopDesc::klass_offset_in_bytes() + sizeof(narrowKlass);
81 }
82
83 inline Klass** oopDesc::klass_addr() {
84 // Only used internally and with CMS and will not work with
85 // UseCompressedOops
86 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers");
87 return (Klass**) &_metadata._klass;
88 }
89
90 inline narrowKlass* oopDesc::compressed_klass_addr() {
91 assert(UseCompressedClassPointers, "only called by compressed klass pointers");
92 return &_metadata._compressed_klass;
93 }
94
95 inline void oopDesc::set_klass(Klass* k) {
96 // since klasses are promoted no store check is needed
97 assert(Universe::is_bootstrapping() || k != NULL, "must be a real Klass*");
98 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass*");
99 if (UseCompressedClassPointers) {
100 *compressed_klass_addr() = Klass::encode_klass_not_null(k);
101 } else {
102 *klass_addr() = k;
103 }
104 }
105
106 inline int oopDesc::klass_gap() const {
107 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
108 }
109
110 inline void oopDesc::set_klass_gap(int v) {
111 if (UseCompressedClassPointers) {
112 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
113 }
114 }
115
116 inline void oopDesc::set_klass_to_list_ptr(oop k) {
117 // This is only to be used during GC, for from-space objects, so no
118 // barrier is needed.
119 if (UseCompressedClassPointers) {
120 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling)
121 } else {
122 _metadata._klass = (Klass*)(address)k;
123 }
124 }
125
126 inline oop oopDesc::list_ptr_from_klass() {
127 // This is only to be used during GC, for from-space objects.
128 if (UseCompressedClassPointers) {
129 return decode_heap_oop((narrowOop)_metadata._compressed_klass);
130 } else {
131 // Special case for GC
132 return (oop)(address)_metadata._klass;
133 }
134 }
135
136 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); }
137
138 inline bool oopDesc::is_a(Klass* k) const { return klass()->is_subtype_of(k); }
139
140 inline bool oopDesc::is_instance() const { return klass()->oop_is_instance(); }
141 inline bool oopDesc::is_instanceClassLoader() const { return klass()->oop_is_instanceClassLoader(); }
142 inline bool oopDesc::is_instanceMirror() const { return klass()->oop_is_instanceMirror(); }
143 inline bool oopDesc::is_instanceRef() const { return klass()->oop_is_instanceRef(); }
144 inline bool oopDesc::is_array() const { return klass()->oop_is_array(); }
145 inline bool oopDesc::is_objArray() const { return klass()->oop_is_objArray(); }
146 inline bool oopDesc::is_typeArray() const { return klass()->oop_is_typeArray(); }
147
148 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; }
149
150 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
151 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
152 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); }
153 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); }
154 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); }
155 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); }
156 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); }
157 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); }
158 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); }
159 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
160 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
161
162
163 // Functions for getting and setting oops within instance objects.
164 // If the oops are compressed, the type passed to these overloaded functions
165 // is narrowOop. All functions are overloaded so they can be called by
166 // template functions without conditionals (the compiler instantiates via
167 // the right type and inlines the appopriate code).
168
169 inline bool oopDesc::is_null(oop obj) { return obj == NULL; }
170 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }
171
172 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
173 // offset from the heap base. Saving the check for null can save instructions
174 // in inner GC loops so these are separated.
175
176 inline bool check_obj_alignment(oop obj) {
177 return cast_from_oop<intptr_t>(obj) % MinObjAlignmentInBytes == 0;
178 }
179
180 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
181 assert(!is_null(v), "oop value can never be zero");
182 assert(check_obj_alignment(v), "Address not aligned");
183 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
184 address base = Universe::narrow_oop_base();
185 int shift = Universe::narrow_oop_shift();
186 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
187 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
188 uint64_t result = pd >> shift;
189 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
190 assert(decode_heap_oop(result) == v, "reversibility");
191 return (narrowOop)result;
192 }
193
194 inline narrowOop oopDesc::encode_heap_oop(oop v) {
195 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
196 }
197
198 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
199 assert(!is_null(v), "narrow oop value can never be zero");
200 address base = Universe::narrow_oop_base();
201 int shift = Universe::narrow_oop_shift();
202 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
203 assert(check_obj_alignment(result), err_msg("address not aligned: " INTPTR_FORMAT, p2i((void*) result)));
204 return result;
205 }
206
207 inline oop oopDesc::decode_heap_oop(narrowOop v) {
208 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
209 }
210
211 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
212 inline oop oopDesc::decode_heap_oop(oop v) { return v; }
213
214 // Load an oop out of the Java heap as is without decoding.
215 // Called by GC to check for null before decoding.
216 inline oop oopDesc::load_heap_oop(oop* p) { return *p; }
217 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
218
219 // Load and decode an oop out of the Java heap into a wide oop.
220 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
221 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
222 return decode_heap_oop_not_null(*p);
223 }
224
225 // Load and decode an oop out of the heap accepting null
226 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
227 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
228 return decode_heap_oop(*p);
229 }
230
231 // Store already encoded heap oop into the heap.
232 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; }
233 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
234
235 // Encode and store a heap oop.
236 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
237 *p = encode_heap_oop_not_null(v);
238 }
239 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
240
241 // Encode and store a heap oop allowing for null.
242 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
243 *p = encode_heap_oop(v);
244 }
245 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
246
247 // Store heap oop as is for volatile fields.
248 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
249 OrderAccess::release_store_ptr(p, v);
250 }
251 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
252 narrowOop v) {
253 OrderAccess::release_store(p, v);
254 }
255
256 inline void oopDesc::release_encode_store_heap_oop_not_null(
257 volatile narrowOop* p, oop v) {
258 // heap oop is not pointer sized.
259 OrderAccess::release_store(p, encode_heap_oop_not_null(v));
260 }
261
262 inline void oopDesc::release_encode_store_heap_oop_not_null(
263 volatile oop* p, oop v) {
264 OrderAccess::release_store_ptr(p, v);
265 }
266
267 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
268 oop v) {
269 OrderAccess::release_store_ptr(p, v);
270 }
271 inline void oopDesc::release_encode_store_heap_oop(
272 volatile narrowOop* p, oop v) {
273 OrderAccess::release_store(p, encode_heap_oop(v));
274 }
275
276
277 // These functions are only used to exchange oop fields in instances,
278 // not headers.
279 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
280 if (UseCompressedOops) {
281 // encode exchange value from oop to T
282 narrowOop val = encode_heap_oop(exchange_value);
283 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
284 // decode old from T to oop
285 return decode_heap_oop(old);
286 } else {
287 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
288 }
289 }
290
291 // In order to put or get a field out of an instance, must first check
292 // if the field has been compressed and uncompress it.
293 inline oop oopDesc::obj_field(int offset) const {
294 return UseCompressedOops ?
295 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
296 load_decode_heap_oop(obj_field_addr<oop>(offset));
297 }
298 inline volatile oop oopDesc::obj_field_volatile(int offset) const {
299 volatile oop value = obj_field(offset);
300 OrderAccess::acquire();
301 return value;
302 }
303 inline void oopDesc::obj_field_put(int offset, oop value) {
304 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
305 oop_store(obj_field_addr<oop>(offset), value);
306 }
307
308 inline Metadata* oopDesc::metadata_field(int offset) const {
309 return *metadata_field_addr(offset);
310 }
311
312 inline void oopDesc::metadata_field_put(int offset, Metadata* value) {
313 *metadata_field_addr(offset) = value;
314 }
315
316 inline void oopDesc::obj_field_put_raw(int offset, oop value) {
317 UseCompressedOops ?
318 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
319 encode_store_heap_oop(obj_field_addr<oop>(offset), value);
320 }
321 inline void oopDesc::obj_field_put_volatile(int offset, oop value) {
322 OrderAccess::release();
323 obj_field_put(offset, value);
324 OrderAccess::fence();
325 }
326
327 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); }
328 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; }
329
330 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); }
331 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (jint) contents; }
332
333 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); }
334 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; }
335
336 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); }
337 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; }
338
339 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); }
340 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;}
341
342 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); }
343 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; }
344
345 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); }
346 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; }
347
348 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); }
349 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
350
351 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); }
352 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
353
354 inline oop oopDesc::obj_field_acquire(int offset) const {
355 return UseCompressedOops ?
356 decode_heap_oop((narrowOop)
357 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
358 : decode_heap_oop((oop)
359 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
360 }
361 inline void oopDesc::release_obj_field_put(int offset, oop value) {
362 UseCompressedOops ?
363 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
364 oop_store((volatile oop*) obj_field_addr<oop>(offset), value);
365 }
366
367 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); }
368 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); }
369
370 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); }
371 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), contents); }
372
373 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); }
374 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); }
375
376 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); }
377 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); }
378
379 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
380 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); }
381
382 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); }
383 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); }
384
385 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); }
386 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); }
387
388 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); }
389 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
390
391 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
392 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
393
394 inline int oopDesc::size_given_klass(Klass* klass) {
395 int lh = klass->layout_helper();
396 int s;
397
398 // lh is now a value computed at class initialization that may hint
399 // at the size. For instances, this is positive and equal to the
400 // size. For arrays, this is negative and provides log2 of the
401 // array element size. For other oops, it is zero and thus requires
402 // a virtual call.
403 //
404 // We go to all this trouble because the size computation is at the
405 // heart of phase 2 of mark-compaction, and called for every object,
406 // alive or dead. So the speed here is equal in importance to the
407 // speed of allocation.
408
409 if (lh > Klass::_lh_neutral_value) {
410 if (!Klass::layout_helper_needs_slow_path(lh)) {
411 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
412 } else {
413 s = klass->oop_size(this);
414 }
415 } else if (lh <= Klass::_lh_neutral_value) {
416 // The most common case is instances; fall through if so.
417 if (lh < Klass::_lh_neutral_value) {
418 // Second most common case is arrays. We have to fetch the
419 // length of the array, shift (multiply) it appropriately,
420 // up to wordSize, add the header, and align to object size.
421 size_t size_in_bytes;
422 #ifdef _M_IA64
423 // The Windows Itanium Aug 2002 SDK hoists this load above
424 // the check for s < 0. An oop at the end of the heap will
425 // cause an access violation if this load is performed on a non
426 // array oop. Making the reference volatile prohibits this.
427 // (%%% please explain by what magic the length is actually fetched!)
428 volatile int *array_length;
429 array_length = (volatile int *)( (intptr_t)this +
430 arrayOopDesc::length_offset_in_bytes() );
431 assert(array_length > 0, "Integer arithmetic problem somewhere");
432 // Put into size_t to avoid overflow.
433 size_in_bytes = (size_t) array_length;
434 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
435 #else
436 size_t array_length = (size_t) ((arrayOop)this)->length();
437 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
438 #endif
439 size_in_bytes += Klass::layout_helper_header_size(lh);
440
441 // This code could be simplified, but by keeping array_header_in_bytes
442 // in units of bytes and doing it this way we can round up just once,
443 // skipping the intermediate round to HeapWordSize. Cast the result
444 // of round_to to size_t to guarantee unsigned division == right shift.
445 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
446 HeapWordSize);
447
448 // UseParNewGC, UseParallelGC and UseG1GC can change the length field
449 // of an "old copy" of an object array in the young gen so it indicates
450 // the grey portion of an already copied array. This will cause the first
451 // disjunct below to fail if the two comparands are computed across such
452 // a concurrent change.
453 // UseParNewGC also runs with promotion labs (which look like int
454 // filler arrays) which are subject to changing their declared size
455 // when finally retiring a PLAB; this also can cause the first disjunct
456 // to fail for another worker thread that is concurrently walking the block
457 // offset table. Both these invariant failures are benign for their
458 // current uses; we relax the assertion checking to cover these two cases below:
459 // is_objArray() && is_forwarded() // covers first scenario above
460 // || is_typeArray() // covers second scenario above
461 // If and when UseParallelGC uses the same obj array oop stealing/chunking
462 // technique, we will need to suitably modify the assertion.
463 assert((s == klass->oop_size(this)) ||
464 (Universe::heap()->is_gc_active() &&
465 ((is_typeArray() && UseParNewGC) ||
466 (is_objArray() && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))),
467 "wrong array object size");
468 } else {
469 // Must be zero, so bite the bullet and take the virtual call.
470 s = klass->oop_size(this);
471 }
472 }
473
474 assert(s % MinObjAlignment == 0, "alignment check");
475 assert(s > 0, "Bad size calculated");
476 return s;
477 }
478
479
480 inline int oopDesc::size() {
481 return size_given_klass(klass());
482 }
483
484 inline void update_barrier_set(void* p, oop v, bool release = false) {
485 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
486 oopDesc::bs()->write_ref_field(p, v, release);
487 }
488
489 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
490 oopDesc::bs()->write_ref_field_pre(p, v);
491 }
492
493 template <class T> inline void oop_store(T* p, oop v) {
494 if (always_do_update_barrier) {
495 oop_store((volatile T*)p, v);
496 } else {
497 update_barrier_set_pre(p, v);
498 oopDesc::encode_store_heap_oop(p, v);
499 // always_do_update_barrier == false =>
500 // Either we are at a safepoint (in GC) or CMS is not used. In both
501 // cases it's unnecessary to mark the card as dirty with release sematics.
502 update_barrier_set((void*)p, v, false /* release */); // cast away type
503 }
504 }
505
506 template <class T> inline void oop_store(volatile T* p, oop v) {
507 update_barrier_set_pre((T*)p, v); // cast away volatile
508 // Used by release_obj_field_put, so use release_store_ptr.
509 oopDesc::release_encode_store_heap_oop(p, v);
510 // When using CMS we must mark the card corresponding to p as dirty
511 // with release sematics to prevent that CMS sees the dirty card but
512 // not the new value v at p due to reordering of the two
513 // stores. Note that CMS has a concurrent precleaning phase, where
514 // it reads the card table while the Java threads are running.
515 update_barrier_set((void*)p, v, true /* release */); // cast away type
516 }
517
518 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
519 // (without having to remember the function name this calls).
520 inline void oop_store_raw(HeapWord* addr, oop value) {
521 if (UseCompressedOops) {
522 oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
523 } else {
524 oopDesc::encode_store_heap_oop((oop*)addr, value);
525 }
526 }
527
528 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
529 volatile HeapWord *dest,
530 oop compare_value,
531 bool prebarrier) {
532 if (UseCompressedOops) {
533 if (prebarrier) {
534 update_barrier_set_pre((narrowOop*)dest, exchange_value);
535 }
536 // encode exchange and compare value from oop to T
537 narrowOop val = encode_heap_oop(exchange_value);
538 narrowOop cmp = encode_heap_oop(compare_value);
539
540 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
541 // decode old from T to oop
542 return decode_heap_oop(old);
543 } else {
544 if (prebarrier) {
545 update_barrier_set_pre((oop*)dest, exchange_value);
546 }
547 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
548 }
549 }
550
551 // Used only for markSweep, scavenging
552 inline bool oopDesc::is_gc_marked() const {
553 return mark()->is_marked();
554 }
555
556 inline bool oopDesc::is_locked() const {
557 return mark()->is_locked();
558 }
559
560 inline bool oopDesc::is_unlocked() const {
561 return mark()->is_unlocked();
562 }
563
564 inline bool oopDesc::has_bias_pattern() const {
565 return mark()->has_bias_pattern();
566 }
567
568
569 // used only for asserts
570 inline bool oopDesc::is_oop(bool ignore_mark_word) const {
571 oop obj = (oop) this;
572 if (!check_obj_alignment(obj)) return false;
573 if (!Universe::heap()->is_in_reserved(obj)) return false;
574 // obj is aligned and accessible in heap
575 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false;
576
577 // Header verification: the mark is typically non-NULL. If we're
578 // at a safepoint, it must not be null.
579 // Outside of a safepoint, the header could be changing (for example,
580 // another thread could be inflating a lock on this object).
581 if (ignore_mark_word) {
582 return true;
583 }
584 if (mark() != NULL) {
585 return true;
586 }
587 return !SafepointSynchronize::is_at_safepoint();
588 }
589
590
591 // used only for asserts
592 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
593 return this == NULL ? true : is_oop(ignore_mark_word);
594 }
595
596 #ifndef PRODUCT
597 // used only for asserts
598 inline bool oopDesc::is_unlocked_oop() const {
599 if (!Universe::heap()->is_in_reserved(this)) return false;
600 return mark()->is_unlocked();
601 }
602 #endif // PRODUCT
603
604 inline void oopDesc::follow_contents(void) {
605 assert (is_gc_marked(), "should be marked");
606 klass()->oop_follow_contents(this);
607 }
608
609 // Used by scavengers
610
611 inline bool oopDesc::is_forwarded() const {
612 // The extra heap check is needed since the obj might be locked, in which case the
613 // mark would point to a stack location and have the sentinel bit cleared
614 return mark()->is_marked();
615 }
616
617 // Used by scavengers
618 inline void oopDesc::forward_to(oop p) {
619 assert(check_obj_alignment(p),
620 "forwarding to something not aligned");
621 assert(Universe::heap()->is_in_reserved(p),
622 "forwarding to something not in heap");
623 markOop m = markOopDesc::encode_pointer_as_mark(p);
624 assert(m->decode_pointer() == p, "encoding must be reversable");
625 set_mark(m);
626 }
627
628 // Used by parallel scavengers
629 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
630 assert(check_obj_alignment(p),
631 "forwarding to something not aligned");
632 assert(Universe::heap()->is_in_reserved(p),
633 "forwarding to something not in heap");
634 markOop m = markOopDesc::encode_pointer_as_mark(p);
635 assert(m->decode_pointer() == p, "encoding must be reversable");
636 return cas_set_mark(m, compare) == compare;
637 }
638
639 // Note that the forwardee is not the same thing as the displaced_mark.
640 // The forwardee is used when copying during scavenge and mark-sweep.
641 // It does need to clear the low two locking- and GC-related bits.
642 inline oop oopDesc::forwardee() const {
643 return (oop) mark()->decode_pointer();
644 }
645
646 inline bool oopDesc::has_displaced_mark() const {
647 return mark()->has_displaced_mark_helper();
648 }
649
650 inline markOop oopDesc::displaced_mark() const {
651 return mark()->displaced_mark_helper();
652 }
653
654 inline void oopDesc::set_displaced_mark(markOop m) {
655 mark()->set_displaced_mark_helper(m);
656 }
657
658 // The following method needs to be MT safe.
659 inline uint oopDesc::age() const {
660 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
661 if (has_displaced_mark()) {
662 return displaced_mark()->age();
663 } else {
664 return mark()->age();
665 }
666 }
667
668 inline void oopDesc::incr_age() {
669 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
670 if (has_displaced_mark()) {
671 set_displaced_mark(displaced_mark()->incr_age());
672 } else {
673 set_mark(mark()->incr_age());
674 }
675 }
676
677
678 inline intptr_t oopDesc::identity_hash() {
679 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
680 // Note: The mark must be read into local variable to avoid concurrent updates.
681 markOop mrk = mark();
682 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
683 return mrk->hash();
684 } else if (mrk->is_marked()) {
685 return mrk->hash();
686 } else {
687 return slow_identity_hash();
688 }
689 }
690
691 template <class OopClosureType>
692 inline typename enable_if<is_kind_of<ExtendedOopClosure, OopClosureType>::value, void>::type
693 oopDesc::do_metadata_if_applicable(OopClosureType *cl) {
694 if (OopClosureDispatcher::do_metadata<OopClosureType>(cl)) {
695 OopClosureDispatcher::do_klass<OopClosureType>(cl, klass());
696 }
697 }
698
699 template <class OopClosureType>
700 inline typename enable_if<!is_kind_of<ExtendedOopClosure, OopClosureType>::value, void>::type
701 oopDesc::do_metadata_if_applicable(OopClosureType *cl) {}
702
703 template <class OopClosureType>
704 inline int oopDesc::oop_iterate_dispatch_tag(OopClosureType *blk, DispatchTag tag) {
705 // Closure is not explicitly specialized; determine which klass with a tag and call an inline dispatch method.
706 switch (tag) {
707 case _instance_mirror_klass: return static_cast<InstanceMirrorKlass*>(klass())->oop_iterate_and_dispatch<OopClosureType>(this, blk);
708 case _instance_class_loader_klass: return static_cast<InstanceClassLoaderKlass*>(klass())->InstanceClassLoaderKlass::oop_iterate_and_dispatch<OopClosureType>(this, blk);
709 case _instance_ref_klass: return static_cast<InstanceRefKlass*>(klass())->InstanceRefKlass::oop_iterate_and_dispatch<OopClosureType>(this, blk);
710 }
711 ShouldNotReachHere();
712 return -1;
713 }
714
715 inline int oopDesc::adjust_pointers() {
716 debug_only(int check_size = size());
717 int s = klass()->oop_adjust_pointers(this);
718 assert(s == check_size, "should be the same");
719 return s;
720 }
721
722 template <class OopClosureType>
723 inline int oopDesc::oop_iterate_internal(OopClosureType *blk) {
724 SpecializationStats::record_call();
725 Klass::OopInterval interval; // Allocate space for an interval for arrays just in case it's needed
726 Klass::OopInterval *current = &interval;
727 int size;
728 int count = klass()->get_linear_oop_intervals(this, current, size);
729 if (count >= 0) {
730 if (UseCompressedOops) {
731 for (int i = 0; i < count; i++) {
732 narrowOop *current_oop = this->obj_field_addr<narrowOop>(current->_offset);
733 for (uint j = 0; j < current->_size; j++) {
734 OopClosureDispatcher::do_oop<OopClosureType, narrowOop>(blk, current_oop);
735 current_oop++;
736 }
737 }
738 current++;
739 } else {
740 for (int i = 0; i < count; i++) {
741 oop *current_oop = this->obj_field_addr<oop>(current->_offset);
742 for (uint j = 0; j < current->_size; j++) {
743 OopClosureDispatcher::do_oop<OopClosureType, oop>(blk, current_oop);
744 current_oop++;
745 }
746 }
747 current++;
748 }
749
750 // The below call uses SFINAE and does nothing if the closure is not an ExtendedOopClosure
751 // Otherwise, if it is, it checks if it should send in metadata into the closure too and then does so
752 do_metadata_if_applicable<OopClosureType>(blk);
753
754 return size;
755 } else {
756 // The Klass is of a slightly more advanced type, falling back to dispatch tag solution.
757 // This fallback parses the returned tag and identifies the klass implementation and calls it.
758 return oop_iterate_dispatch_tag<OopClosureType>(blk, DispatchTag(-count));
759 }
760 }
761
762 template <class OopClosureType>
763 inline typename enable_if<is_kind_of<ExtendedOopClosure, OopClosureType>::value, int>::type
764 oopDesc::oop_iterate(OopClosureType *blk) {
765 return oop_iterate_internal<OopClosureType>(blk);
766 }
767
768 template <class OopClosureType>
769 inline typename enable_if<is_kind_of<OopClosure, OopClosureType>::value, int>::type
770 oopDesc::oop_iterate_no_header(OopClosureType *blk) {
771 if (is_kind_of<ExtendedOopClosure, OopClosureType>::value) {
772 NoHeaderOopClosure<OopClosureType> cl(blk);
773 return oop_iterate_internal(&cl);
774 } else {
775 return oop_iterate_internal(blk);
776 }
777 }
778
779 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
780 NoHeaderExtendedOopClosure cl(blk);
781 return oop_iterate(&cl, mr);
782 }
783
784 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
785 \
786 inline int oopDesc::oop_iterate(OopClosureType* blk) { \
787 SpecializationStats::record_call(); \
788 return klass()->oop_oop_iterate##nv_suffix(this, blk); \
789 } \
790 \
791 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
792 SpecializationStats::record_call(); \
793 return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \
794 }
795
796 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN)
797 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN)
798
799 #if INCLUDE_ALL_GCS
800 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
801 \
802 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
803 SpecializationStats::record_call(); \
804 return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
805 }
806
807 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN)
808 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN)
809 #endif // INCLUDE_ALL_GCS
810
811 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP