Thu, 13 Jan 2011 22:15:41 -0800
4926272: methodOopDesc::method_from_bcp is unsafe
Reviewed-by: coleenp, jrose, kvn, dcubed
1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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25 #ifndef SHARE_VM_OOPS_OOP_INLINE_HPP
26 #define SHARE_VM_OOPS_OOP_INLINE_HPP
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/compactingPermGenGen.hpp"
34 #include "memory/genCollectedHeap.hpp"
35 #include "memory/generation.hpp"
36 #include "memory/permGen.hpp"
37 #include "memory/specialized_oop_closures.hpp"
38 #include "oops/arrayKlass.hpp"
39 #include "oops/arrayOop.hpp"
40 #include "oops/klass.hpp"
41 #include "oops/klassOop.hpp"
42 #include "oops/markOop.inline.hpp"
43 #include "oops/oop.hpp"
44 #include "runtime/atomic.hpp"
45 #include "runtime/os.hpp"
46 #ifdef TARGET_ARCH_x86
47 # include "bytes_x86.hpp"
48 #endif
49 #ifdef TARGET_ARCH_sparc
50 # include "bytes_sparc.hpp"
51 #endif
52 #ifdef TARGET_ARCH_zero
53 # include "bytes_zero.hpp"
54 #endif
56 // Implementation of all inlined member functions defined in oop.hpp
57 // We need a separate file to avoid circular references
59 inline void oopDesc::release_set_mark(markOop m) {
60 OrderAccess::release_store_ptr(&_mark, m);
61 }
63 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
64 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
65 }
67 inline klassOop oopDesc::klass() const {
68 if (UseCompressedOops) {
69 return (klassOop)decode_heap_oop_not_null(_metadata._compressed_klass);
70 } else {
71 return _metadata._klass;
72 }
73 }
75 inline klassOop oopDesc::klass_or_null() const volatile {
76 // can be NULL in CMS
77 if (UseCompressedOops) {
78 return (klassOop)decode_heap_oop(_metadata._compressed_klass);
79 } else {
80 return _metadata._klass;
81 }
82 }
84 inline int oopDesc::klass_gap_offset_in_bytes() {
85 assert(UseCompressedOops, "only applicable to compressed headers");
86 return oopDesc::klass_offset_in_bytes() + sizeof(narrowOop);
87 }
89 inline oop* oopDesc::klass_addr() {
90 // Only used internally and with CMS and will not work with
91 // UseCompressedOops
92 assert(!UseCompressedOops, "only supported with uncompressed oops");
93 return (oop*) &_metadata._klass;
94 }
96 inline narrowOop* oopDesc::compressed_klass_addr() {
97 assert(UseCompressedOops, "only called by compressed oops");
98 return (narrowOop*) &_metadata._compressed_klass;
99 }
101 inline void oopDesc::set_klass(klassOop k) {
102 // since klasses are promoted no store check is needed
103 assert(Universe::is_bootstrapping() || k != NULL, "must be a real klassOop");
104 assert(Universe::is_bootstrapping() || k->is_klass(), "not a klassOop");
105 if (UseCompressedOops) {
106 oop_store_without_check(compressed_klass_addr(), (oop)k);
107 } else {
108 oop_store_without_check(klass_addr(), (oop) k);
109 }
110 }
112 inline int oopDesc::klass_gap() const {
113 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
114 }
116 inline void oopDesc::set_klass_gap(int v) {
117 if (UseCompressedOops) {
118 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
119 }
120 }
122 inline void oopDesc::set_klass_to_list_ptr(oop k) {
123 // This is only to be used during GC, for from-space objects, so no
124 // barrier is needed.
125 if (UseCompressedOops) {
126 _metadata._compressed_klass = encode_heap_oop(k); // may be null (parnew overflow handling)
127 } else {
128 _metadata._klass = (klassOop)k;
129 }
130 }
132 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); }
133 inline Klass* oopDesc::blueprint() const { return klass()->klass_part(); }
135 inline bool oopDesc::is_a(klassOop k) const { return blueprint()->is_subtype_of(k); }
137 inline bool oopDesc::is_instance() const { return blueprint()->oop_is_instance(); }
138 inline bool oopDesc::is_instanceRef() const { return blueprint()->oop_is_instanceRef(); }
139 inline bool oopDesc::is_array() const { return blueprint()->oop_is_array(); }
140 inline bool oopDesc::is_objArray() const { return blueprint()->oop_is_objArray(); }
141 inline bool oopDesc::is_typeArray() const { return blueprint()->oop_is_typeArray(); }
142 inline bool oopDesc::is_javaArray() const { return blueprint()->oop_is_javaArray(); }
143 inline bool oopDesc::is_symbol() const { return blueprint()->oop_is_symbol(); }
144 inline bool oopDesc::is_klass() const { return blueprint()->oop_is_klass(); }
145 inline bool oopDesc::is_thread() const { return blueprint()->oop_is_thread(); }
146 inline bool oopDesc::is_method() const { return blueprint()->oop_is_method(); }
147 inline bool oopDesc::is_constMethod() const { return blueprint()->oop_is_constMethod(); }
148 inline bool oopDesc::is_methodData() const { return blueprint()->oop_is_methodData(); }
149 inline bool oopDesc::is_constantPool() const { return blueprint()->oop_is_constantPool(); }
150 inline bool oopDesc::is_constantPoolCache() const { return blueprint()->oop_is_constantPoolCache(); }
151 inline bool oopDesc::is_compiledICHolder() const { return blueprint()->oop_is_compiledICHolder(); }
153 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; }
155 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
156 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); }
157 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); }
158 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); }
159 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); }
160 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); }
161 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); }
162 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); }
163 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
164 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
167 // Functions for getting and setting oops within instance objects.
168 // If the oops are compressed, the type passed to these overloaded functions
169 // is narrowOop. All functions are overloaded so they can be called by
170 // template functions without conditionals (the compiler instantiates via
171 // the right type and inlines the appopriate code).
173 inline bool oopDesc::is_null(oop obj) { return obj == NULL; }
174 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }
176 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
177 // offset from the heap base. Saving the check for null can save instructions
178 // in inner GC loops so these are separated.
180 inline bool check_obj_alignment(oop obj) {
181 return (intptr_t)obj % MinObjAlignmentInBytes == 0;
182 }
184 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
185 assert(!is_null(v), "oop value can never be zero");
186 assert(check_obj_alignment(v), "Address not aligned");
187 assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
188 address base = Universe::narrow_oop_base();
189 int shift = Universe::narrow_oop_shift();
190 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
191 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
192 uint64_t result = pd >> shift;
193 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
194 assert(decode_heap_oop(result) == v, "reversibility");
195 return (narrowOop)result;
196 }
198 inline narrowOop oopDesc::encode_heap_oop(oop v) {
199 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
200 }
202 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
203 assert(!is_null(v), "narrow oop value can never be zero");
204 address base = Universe::narrow_oop_base();
205 int shift = Universe::narrow_oop_shift();
206 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
207 assert(check_obj_alignment(result), err_msg("address not aligned: " PTR_FORMAT, (void*) result));
208 return result;
209 }
211 inline oop oopDesc::decode_heap_oop(narrowOop v) {
212 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
213 }
215 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
216 inline oop oopDesc::decode_heap_oop(oop v) { return v; }
218 // Load an oop out of the Java heap as is without decoding.
219 // Called by GC to check for null before decoding.
220 inline oop oopDesc::load_heap_oop(oop* p) { return *p; }
221 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
223 // Load and decode an oop out of the Java heap into a wide oop.
224 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
225 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
226 return decode_heap_oop_not_null(*p);
227 }
229 // Load and decode an oop out of the heap accepting null
230 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
231 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
232 return decode_heap_oop(*p);
233 }
235 // Store already encoded heap oop into the heap.
236 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; }
237 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
239 // Encode and store a heap oop.
240 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
241 *p = encode_heap_oop_not_null(v);
242 }
243 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
245 // Encode and store a heap oop allowing for null.
246 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
247 *p = encode_heap_oop(v);
248 }
249 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
251 // Store heap oop as is for volatile fields.
252 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
253 OrderAccess::release_store_ptr(p, v);
254 }
255 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
256 narrowOop v) {
257 OrderAccess::release_store(p, v);
258 }
260 inline void oopDesc::release_encode_store_heap_oop_not_null(
261 volatile narrowOop* p, oop v) {
262 // heap oop is not pointer sized.
263 OrderAccess::release_store(p, encode_heap_oop_not_null(v));
264 }
266 inline void oopDesc::release_encode_store_heap_oop_not_null(
267 volatile oop* p, oop v) {
268 OrderAccess::release_store_ptr(p, v);
269 }
271 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
272 oop v) {
273 OrderAccess::release_store_ptr(p, v);
274 }
275 inline void oopDesc::release_encode_store_heap_oop(
276 volatile narrowOop* p, oop v) {
277 OrderAccess::release_store(p, encode_heap_oop(v));
278 }
281 // These functions are only used to exchange oop fields in instances,
282 // not headers.
283 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
284 if (UseCompressedOops) {
285 // encode exchange value from oop to T
286 narrowOop val = encode_heap_oop(exchange_value);
287 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
288 // decode old from T to oop
289 return decode_heap_oop(old);
290 } else {
291 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
292 }
293 }
295 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
296 volatile HeapWord *dest,
297 oop compare_value) {
298 if (UseCompressedOops) {
299 // encode exchange and compare value from oop to T
300 narrowOop val = encode_heap_oop(exchange_value);
301 narrowOop cmp = encode_heap_oop(compare_value);
303 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
304 // decode old from T to oop
305 return decode_heap_oop(old);
306 } else {
307 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
308 }
309 }
311 // In order to put or get a field out of an instance, must first check
312 // if the field has been compressed and uncompress it.
313 inline oop oopDesc::obj_field(int offset) const {
314 return UseCompressedOops ?
315 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
316 load_decode_heap_oop(obj_field_addr<oop>(offset));
317 }
318 inline void oopDesc::obj_field_put(int offset, oop value) {
319 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
320 oop_store(obj_field_addr<oop>(offset), value);
321 }
322 inline void oopDesc::obj_field_raw_put(int offset, oop value) {
323 UseCompressedOops ?
324 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
325 encode_store_heap_oop(obj_field_addr<oop>(offset), value);
326 }
328 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); }
329 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; }
331 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); }
332 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (jint) contents; }
334 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); }
335 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; }
337 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); }
338 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; }
340 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); }
341 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;}
343 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); }
344 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; }
346 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); }
347 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; }
349 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); }
350 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
352 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); }
353 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
355 inline oop oopDesc::obj_field_acquire(int offset) const {
356 return UseCompressedOops ?
357 decode_heap_oop((narrowOop)
358 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
359 : decode_heap_oop((oop)
360 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
361 }
362 inline void oopDesc::release_obj_field_put(int offset, oop value) {
363 UseCompressedOops ?
364 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
365 oop_store((volatile oop*) obj_field_addr<oop>(offset), value);
366 }
368 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); }
369 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); }
371 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); }
372 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), contents); }
374 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); }
375 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); }
377 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); }
378 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); }
380 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
381 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); }
383 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); }
384 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); }
386 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); }
387 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); }
389 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); }
390 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
392 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
393 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
395 inline int oopDesc::size_given_klass(Klass* klass) {
396 int lh = klass->layout_helper();
397 int s = lh >> LogHeapWordSize; // deliver size scaled by wordSize
399 // lh is now a value computed at class initialization that may hint
400 // at the size. For instances, this is positive and equal to the
401 // size. For arrays, this is negative and provides log2 of the
402 // array element size. For other oops, it is zero and thus requires
403 // a virtual call.
404 //
405 // We go to all this trouble because the size computation is at the
406 // heart of phase 2 of mark-compaction, and called for every object,
407 // alive or dead. So the speed here is equal in importance to the
408 // speed of allocation.
410 if (lh <= Klass::_lh_neutral_value) {
411 // The most common case is instances; fall through if so.
412 if (lh < Klass::_lh_neutral_value) {
413 // Second most common case is arrays. We have to fetch the
414 // length of the array, shift (multiply) it appropriately,
415 // up to wordSize, add the header, and align to object size.
416 size_t size_in_bytes;
417 #ifdef _M_IA64
418 // The Windows Itanium Aug 2002 SDK hoists this load above
419 // the check for s < 0. An oop at the end of the heap will
420 // cause an access violation if this load is performed on a non
421 // array oop. Making the reference volatile prohibits this.
422 // (%%% please explain by what magic the length is actually fetched!)
423 volatile int *array_length;
424 array_length = (volatile int *)( (intptr_t)this +
425 arrayOopDesc::length_offset_in_bytes() );
426 assert(array_length > 0, "Integer arithmetic problem somewhere");
427 // Put into size_t to avoid overflow.
428 size_in_bytes = (size_t) array_length;
429 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
430 #else
431 size_t array_length = (size_t) ((arrayOop)this)->length();
432 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
433 #endif
434 size_in_bytes += Klass::layout_helper_header_size(lh);
436 // This code could be simplified, but by keeping array_header_in_bytes
437 // in units of bytes and doing it this way we can round up just once,
438 // skipping the intermediate round to HeapWordSize. Cast the result
439 // of round_to to size_t to guarantee unsigned division == right shift.
440 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
441 HeapWordSize);
443 // UseParNewGC, UseParallelGC and UseG1GC can change the length field
444 // of an "old copy" of an object array in the young gen so it indicates
445 // the grey portion of an already copied array. This will cause the first
446 // disjunct below to fail if the two comparands are computed across such
447 // a concurrent change.
448 // UseParNewGC also runs with promotion labs (which look like int
449 // filler arrays) which are subject to changing their declared size
450 // when finally retiring a PLAB; this also can cause the first disjunct
451 // to fail for another worker thread that is concurrently walking the block
452 // offset table. Both these invariant failures are benign for their
453 // current uses; we relax the assertion checking to cover these two cases below:
454 // is_objArray() && is_forwarded() // covers first scenario above
455 // || is_typeArray() // covers second scenario above
456 // If and when UseParallelGC uses the same obj array oop stealing/chunking
457 // technique, we will need to suitably modify the assertion.
458 assert((s == klass->oop_size(this)) ||
459 (Universe::heap()->is_gc_active() &&
460 ((is_typeArray() && UseParNewGC) ||
461 (is_objArray() && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))),
462 "wrong array object size");
463 } else {
464 // Must be zero, so bite the bullet and take the virtual call.
465 s = klass->oop_size(this);
466 }
467 }
469 assert(s % MinObjAlignment == 0, "alignment check");
470 assert(s > 0, "Bad size calculated");
471 return s;
472 }
475 inline int oopDesc::size() {
476 return size_given_klass(blueprint());
477 }
479 inline bool oopDesc::is_parsable() {
480 return blueprint()->oop_is_parsable(this);
481 }
483 inline bool oopDesc::is_conc_safe() {
484 return blueprint()->oop_is_conc_safe(this);
485 }
487 inline void update_barrier_set(void* p, oop v) {
488 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
489 oopDesc::bs()->write_ref_field(p, v);
490 }
492 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
493 oopDesc::bs()->write_ref_field_pre(p, v);
494 }
496 template <class T> inline void oop_store(T* p, oop v) {
497 if (always_do_update_barrier) {
498 oop_store((volatile T*)p, v);
499 } else {
500 update_barrier_set_pre(p, v);
501 oopDesc::encode_store_heap_oop(p, v);
502 update_barrier_set((void*)p, v); // cast away type
503 }
504 }
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 update_barrier_set((void*)p, v); // cast away type
511 }
513 template <class T> inline void oop_store_without_check(T* p, oop v) {
514 // XXX YSR FIX ME!!!
515 if (always_do_update_barrier) {
516 oop_store(p, v);
517 } else {
518 assert(!Universe::heap()->barrier_set()->write_ref_needs_barrier(p, v),
519 "oop store without store check failed");
520 oopDesc::encode_store_heap_oop(p, v);
521 }
522 }
524 // When it absolutely has to get there.
525 template <class T> inline void oop_store_without_check(volatile T* p, oop v) {
526 // XXX YSR FIX ME!!!
527 if (always_do_update_barrier) {
528 oop_store(p, v);
529 } else {
530 assert(!Universe::heap()->barrier_set()->write_ref_needs_barrier((T*)p, v),
531 "oop store without store check failed");
532 oopDesc::release_encode_store_heap_oop(p, v);
533 }
534 }
536 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
537 // (without having to remember the function name this calls).
538 inline void oop_store_raw(HeapWord* addr, oop value) {
539 if (UseCompressedOops) {
540 oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
541 } else {
542 oopDesc::encode_store_heap_oop((oop*)addr, value);
543 }
544 }
546 // Used only for markSweep, scavenging
547 inline bool oopDesc::is_gc_marked() const {
548 return mark()->is_marked();
549 }
551 inline bool oopDesc::is_locked() const {
552 return mark()->is_locked();
553 }
555 inline bool oopDesc::is_unlocked() const {
556 return mark()->is_unlocked();
557 }
559 inline bool oopDesc::has_bias_pattern() const {
560 return mark()->has_bias_pattern();
561 }
564 // used only for asserts
565 inline bool oopDesc::is_oop(bool ignore_mark_word) const {
566 oop obj = (oop) this;
567 if (!check_obj_alignment(obj)) return false;
568 if (!Universe::heap()->is_in_reserved(obj)) return false;
569 // obj is aligned and accessible in heap
570 // try to find metaclass cycle safely without seg faulting on bad input
571 // we should reach klassKlassObj by following klass link at most 3 times
572 for (int i = 0; i < 3; i++) {
573 obj = obj->klass_or_null();
574 // klass should be aligned and in permspace
575 if (!check_obj_alignment(obj)) return false;
576 if (!Universe::heap()->is_in_permanent(obj)) return false;
577 }
578 if (obj != Universe::klassKlassObj()) {
579 // During a dump, the _klassKlassObj moved to a shared space.
580 if (DumpSharedSpaces && Universe::klassKlassObj()->is_shared()) {
581 return true;
582 }
583 return false;
584 }
586 // Header verification: the mark is typically non-NULL. If we're
587 // at a safepoint, it must not be null.
588 // Outside of a safepoint, the header could be changing (for example,
589 // another thread could be inflating a lock on this object).
590 if (ignore_mark_word) {
591 return true;
592 }
593 if (mark() != NULL) {
594 return true;
595 }
596 return !SafepointSynchronize::is_at_safepoint();
597 }
600 // used only for asserts
601 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
602 return this == NULL ? true : is_oop(ignore_mark_word);
603 }
605 #ifndef PRODUCT
606 // used only for asserts
607 inline bool oopDesc::is_unlocked_oop() const {
608 if (!Universe::heap()->is_in_reserved(this)) return false;
609 return mark()->is_unlocked();
610 }
611 #endif // PRODUCT
613 inline void oopDesc::follow_header() {
614 if (UseCompressedOops) {
615 MarkSweep::mark_and_push(compressed_klass_addr());
616 } else {
617 MarkSweep::mark_and_push(klass_addr());
618 }
619 }
621 inline void oopDesc::follow_contents(void) {
622 assert (is_gc_marked(), "should be marked");
623 blueprint()->oop_follow_contents(this);
624 }
627 // Used by scavengers
629 inline bool oopDesc::is_forwarded() const {
630 // The extra heap check is needed since the obj might be locked, in which case the
631 // mark would point to a stack location and have the sentinel bit cleared
632 return mark()->is_marked();
633 }
635 // Used by scavengers
636 inline void oopDesc::forward_to(oop p) {
637 assert(check_obj_alignment(p),
638 "forwarding to something not aligned");
639 assert(Universe::heap()->is_in_reserved(p),
640 "forwarding to something not in heap");
641 markOop m = markOopDesc::encode_pointer_as_mark(p);
642 assert(m->decode_pointer() == p, "encoding must be reversable");
643 set_mark(m);
644 }
646 // Used by parallel scavengers
647 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
648 assert(check_obj_alignment(p),
649 "forwarding to something not aligned");
650 assert(Universe::heap()->is_in_reserved(p),
651 "forwarding to something not in heap");
652 markOop m = markOopDesc::encode_pointer_as_mark(p);
653 assert(m->decode_pointer() == p, "encoding must be reversable");
654 return cas_set_mark(m, compare) == compare;
655 }
657 // Note that the forwardee is not the same thing as the displaced_mark.
658 // The forwardee is used when copying during scavenge and mark-sweep.
659 // It does need to clear the low two locking- and GC-related bits.
660 inline oop oopDesc::forwardee() const {
661 return (oop) mark()->decode_pointer();
662 }
664 inline bool oopDesc::has_displaced_mark() const {
665 return mark()->has_displaced_mark_helper();
666 }
668 inline markOop oopDesc::displaced_mark() const {
669 return mark()->displaced_mark_helper();
670 }
672 inline void oopDesc::set_displaced_mark(markOop m) {
673 mark()->set_displaced_mark_helper(m);
674 }
676 // The following method needs to be MT safe.
677 inline int oopDesc::age() const {
678 assert(!is_forwarded(), "Attempt to read age from forwarded mark");
679 if (has_displaced_mark()) {
680 return displaced_mark()->age();
681 } else {
682 return mark()->age();
683 }
684 }
686 inline void oopDesc::incr_age() {
687 assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
688 if (has_displaced_mark()) {
689 set_displaced_mark(displaced_mark()->incr_age());
690 } else {
691 set_mark(mark()->incr_age());
692 }
693 }
696 inline intptr_t oopDesc::identity_hash() {
697 // Fast case; if the object is unlocked and the hash value is set, no locking is needed
698 // Note: The mark must be read into local variable to avoid concurrent updates.
699 markOop mrk = mark();
700 if (mrk->is_unlocked() && !mrk->has_no_hash()) {
701 return mrk->hash();
702 } else if (mrk->is_marked()) {
703 return mrk->hash();
704 } else {
705 return slow_identity_hash();
706 }
707 }
709 inline void oopDesc::oop_iterate_header(OopClosure* blk) {
710 if (UseCompressedOops) {
711 blk->do_oop(compressed_klass_addr());
712 } else {
713 blk->do_oop(klass_addr());
714 }
715 }
717 inline void oopDesc::oop_iterate_header(OopClosure* blk, MemRegion mr) {
718 if (UseCompressedOops) {
719 if (mr.contains(compressed_klass_addr())) {
720 blk->do_oop(compressed_klass_addr());
721 }
722 } else {
723 if (mr.contains(klass_addr())) blk->do_oop(klass_addr());
724 }
725 }
727 inline int oopDesc::adjust_pointers() {
728 debug_only(int check_size = size());
729 int s = blueprint()->oop_adjust_pointers(this);
730 assert(s == check_size, "should be the same");
731 return s;
732 }
734 inline void oopDesc::adjust_header() {
735 if (UseCompressedOops) {
736 MarkSweep::adjust_pointer(compressed_klass_addr());
737 } else {
738 MarkSweep::adjust_pointer(klass_addr());
739 }
740 }
742 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
743 \
744 inline int oopDesc::oop_iterate(OopClosureType* blk) { \
745 SpecializationStats::record_call(); \
746 return blueprint()->oop_oop_iterate##nv_suffix(this, blk); \
747 } \
748 \
749 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \
750 SpecializationStats::record_call(); \
751 return blueprint()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \
752 }
754 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN)
755 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN)
757 #ifndef SERIALGC
758 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
759 \
760 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \
761 SpecializationStats::record_call(); \
762 return blueprint()->oop_oop_iterate_backwards##nv_suffix(this, blk); \
763 }
765 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN)
766 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN)
767 #endif // !SERIALGC
769 inline bool oopDesc::is_shared() const {
770 return CompactingPermGenGen::is_shared(this);
771 }
773 inline bool oopDesc::is_shared_readonly() const {
774 return CompactingPermGenGen::is_shared_readonly(this);
775 }
777 inline bool oopDesc::is_shared_readwrite() const {
778 return CompactingPermGenGen::is_shared_readwrite(this);
779 }
781 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP